National Institute of Diabetes and Digestive and Kidney Diseases
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Research output, citation impact, and the most-cited recent papers from National Institute of Diabetes and Digestive and Kidney Diseases (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from National Institute of Diabetes and Digestive and Kidney Diseases
A new software suite, called Crystallography & NMR System (CNS), has been developed for macromolecular structure determination by X-ray crystallography or solution nuclear magnetic resonance (NMR) spectroscopy. In contrast to existing structure-determination programs, the architecture of CNS is highly flexible, allowing for extension to other structure-determination methods, such as electron microscopy and solid-state NMR spectroscopy. CNS has a hierarchical structure: a high-level hypertext markup language (HTML) user interface, task-oriented user input files, module files, a symbolic structure-determination language (CNS language), and low-level source code. Each layer is accessible to the user. The novice user may just use the HTML interface, while the more advanced user may use any of the other layers. The source code will be distributed, thus source-code modification is possible. The CNS language is sufficiently powerful and flexible that many new algorithms can be easily implemented in the CNS language without changes to the source code. The CNS language allows the user to perform operations on data structures, such as structure factors, electron-density maps, and atomic properties. The power of the CNS language has been demonstrated by the implementation of a comprehensive set of crystallographic procedures for phasing, density modification and refinement. User-friendly task-oriented input files are available for nearly all aspects of macromolecular structure determination by X-ray crystallography and solution NMR.
Hypertension is the most common condition seen in primary care and leads to myocardial infarction, stroke, renal failure, and death if not detected early and treated appropriately. Patients want to be assured that blood pressure (BP) treatment will reduce their disease burden, while clinicians want guidance on hypertension management using the best scientific evidence. This report takes a rigorous, evidence-based approach to recommend treatment thresholds, goals, and medications in the management of hypertension in adults. Evidence was drawn from randomized controlled trials, which represent the gold standard for determining efficacy and effectiveness. Evidence quality and recommendations were graded based on their effect on important outcomes. There is strong evidence to support treating hypertensive persons aged 60 years or older to a BP goal of less than 150/90 mm Hg and hypertensive persons 30 through 59 years of age to a diastolic goal of less than 90 mm Hg; however, there is insufficient evidence in hypertensive persons younger than 60 years for a systolic goal, or in those younger than 30 years for a diastolic goal, so the panel recommends a BP of less than 140/90 mm Hg for those groups based on expert opinion. The same thresholds and goals are recommended for hypertensive adults with diabetes or nondiabetic chronic kidney disease (CKD) as for the general hypertensive population younger than 60 years. There is moderate evidence to support initiating drug treatment with an angiotensin-converting enzyme inhibitor, angiotensin receptor blocker, calcium channel blocker, or thiazide-type diuretic in the nonblack hypertensive population, including those with diabetes. In the black hypertensive population, including those with diabetes, a calcium channel blocker or thiazide-type diuretic is recommended as initial therapy. There is moderate evidence to support initial or add-on antihypertensive therapy with an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in persons with CKD to improve kidney outcomes. Although this guideline provides evidence-based recommendations for the management of high BP and should meet the clinical needs of most patients, these recommendations are not a substitute for clinical judgment, and decisions about care must carefully consider and incorporate the clinical characteristics and circumstances of each individual patient.
BACKGROUND: Glomerular filtration rate (GFR) estimates facilitate detection of chronic kidney disease but require calibration of the serum creatinine assay to the laboratory that developed the equation. The 4-variable equation from the Modification of Diet in Renal Disease (MDRD) Study has been reexpressed for use with a standardized assay. OBJECTIVE: To describe the performance of the revised 4-variable MDRD Study equation and compare it with the performance of the 6-variable MDRD Study and Cockcroft-Gault equations. DESIGN: Comparison of estimated and measured GFR. SETTING: 15 clinical centers participating in a randomized, controlled trial. PATIENTS: 1628 patients with chronic kidney disease participating in the MDRD Study. MEASUREMENTS: Serum creatinine levels were calibrated to an assay traceable to isotope-dilution mass spectrometry. Glomerular filtration rate was measured as urinary clearance of 125I-iothalamate. RESULTS: Mean measured GFR was 39.8 mL/min per 1.73 m2 (SD, 21.2). Accuracy and precision of the revised 4-variable equation were similar to those of the original 6-variable equation and better than in the Cockcroft-Gault equation, even when the latter was corrected for bias, with 90%, 91%, 60%, and 83% of estimates within 30% of measured GFR, respectively. Differences between measured and estimated GFR were greater for all equations when the estimated GFR was 60 mL/min per 1.73 m2 or greater. LIMITATIONS: The MDRD Study included few patients with a GFR greater than 90 mL/min per 1.73 m2. Equations were not compared in a separate study sample. CONCLUSIONS: The 4-variable MDRD Study equation provides reasonably accurate GFR estimates in patients with chronic kidney disease and a measured GFR of less than 90 mL/min per 1.73 m2. By using the reexpressed MDRD Study equation with the standardized serum creatinine assay, clinical laboratories can report more accurate GFR estimates.
The 2005 National Institutes of Health (NIH) Consensus Conference proposed new criteria for diagnosing and scoring the severity of chronic graft-versus-host disease (GVHD). The 2014 NIH consensus maintains the framework of the prior consensus with further refinement based on new evidence. Revisions have been made to address areas of controversy or confusion, such as the overlap chronic GVHD subcategory and the distinction between active disease and past tissue damage. Diagnostic criteria for involvement of mouth, eyes, genitalia, and lungs have been revised. Categories of chronic GVHD should be defined in ways that indicate prognosis, guide treatment, and define eligibility for clinical trials. Revisions have been made to focus attention on the causes of organ-specific abnormalities. Attribution of organ-specific abnormalities to chronic GVHD has been addressed. This paradigm shift provides greater specificity and more accurately measures the global burden of disease attributed to GVHD, and it will facilitate biomarker association studies.
BACKGROUND AND METHODS: The extent to which renal allotransplantation - as compared with long-term dialysis - improves survival among patients with end-stage renal disease is controversial, because those selected for transplantation may have a lower base-line risk of death. In an attempt to distinguish the effects of patient selection from those of transplantation itself, we conducted a longitudinal study of mortality in 228,552 patients who were receiving long-term dialysis for end-stage renal disease. Of these patients, 46,164 were placed on a waiting list for transplantation, 23,275 of whom received a first cadaveric transplant between 1991 and 1997. The relative risk of death and survival were assessed with time-dependent nonproportional-hazards analysis, with adjustment for age, race, sex, cause of end-stage renal disease, geographic region, time from first treatment for end-stage renal disease to placement on the waiting list, and year of initial placement on the list. RESULTS: Among the various subgroups, the standardized mortality ratio for the patients on dialysis who were awaiting transplantation (annual death rate, 6.3 per 100 patient-years) was 38 to 58 percent lower than that for all patients on dialysis (annual death rate, 16.1 per 100 patient-years). The relative risk of death during the first 2 weeks after transplantation was 2.8 times as high as that for patients on dialysis who had equal lengths of follow-up since placement on the waiting list, but at 18 months the risk was much lower (relative risk, 0.32; 95 percent confidence interval, 0.30 to 0.35; P<0.001). The likelihood of survival became equal in the two groups within 5 to 673 days after transplantation in all the subgroups of patients we examined. The long-term mortality rate was 48 to 82 percent lower among transplant recipients (annual death rate, 3.8 per 100 patient-years) than patients on the waiting list, with relatively larger benefits among patients who were 20 to 39 years old, white patients, and younger patients with diabetes. CONCLUSIONS: Among patients with end-stage renal disease, healthier patients are placed on the waiting list for transplantation, and long-term survival is better among those on the waiting list who eventually undergo transplantation.
OBJECTIVE: Individuals with impaired glucose tolerance (IGT) have a high risk of developing NIDDM. The purpose of this study was to determine whether diet and exercise interventions in those with IGT may delay the development of NIDDM, i.e., reduce the incidence of NIDDM, and thereby reduce the overall incidence of diabetic complications, such as cardiovascular, renal, and retinal disease, and the excess mortality attributable to these complications. RESEARCH DESIGN AND METHODS: In 1986, 110,660 men and women from 33 health care clinics in the city of Da Qing, China, were screened for IGT and NIDDM. Of these individuals, 577 were classified (using World Health Organization criteria) as having IGT. Subjects were randomized by clinic into a clinical trial, either to a control group or to one of three active treatment groups: diet only, exercise only, or diet plus exercise. Follow-up evaluation examinations were conducted at 2-year intervals over a 6-year period to identify subjects who developed NIDDM. Cox's proportional hazard analysis was used to determine if the incidence of NIDDM varied by treatment assignment. RESULTS: The cumulative incidence of diabetes at 6 years was 67.7% (95% CI, 59.8-75.2) in the control group compared with 43.8% (95% CI, 35.5-52.3) in the diet group, 41.1% (95% CI, 33.4-49.4) in the exercise group, and 46.0% (95% CI, 37.3-54.7) in the diet-plus-exercise group (P < 0.05). When analyzed by clinic, each of the active intervention groups differed significantly from the control clinics (P < 0.05). The relative decrease in rate of development of diabetes in the active treatment groups was similar when subjects were stratified as lean or overweight (BMI < or > or = 25 kg/m2). In a proportional hazards analysis adjusted for differences in baseline BMI and fasting glucose, the diet, exercise, and diet-plus-exercise interventions were associated with 31% (P < 0.03), 46% (P < 0.0005), and 42% (P < 0.005) reductions in risk of developing diabetes, respectively. CONCLUSIONS: Diet and/or exercise interventions led to a significant decrease in the incidence of diabetes over a 6-year period among those with IGT.
An algorithm was developed which facilitates the search for similarities between newly determined amino acid sequences and sequences already available in databases. Because of the algorithm's efficiency on many microcomputers, sensitive protein database searches may now become a routine procedure for molecular biologists. The method efficiently identifies regions of similar sequence and then scores the aligned identical and differing residues in those regions by means of an amino acid replacability matrix. This matrix increases sensitivity by giving high scores to those amino acid replacements which occur frequently in evolution. The algorithm has been implemented in a computer program designed to search protein databases very rapidly. For example, comparison of a 200-amino-acid sequence to the 500,000 residues in the National Biomedical Research Foundation library would take less than 2 minutes on a minicomputer, and less than 10 minutes on a microcomputer (IBM PC).
The American Diabetes Association and the European Association for the Study of Diabetes convened a panel to update the prior position statements, published in 2012 and 2015, on the management of type 2 diabetes in adults. A systematic evaluation of the literature since 2014 informed new recommendations. These include additional focus on lifestyle management and diabetes self-management education and support. For those with obesity, efforts targeting weight loss, including lifestyle, medication, and surgical interventions, are recommended. With regards to medication management, for patients with clinical cardiovascular disease, a sodium-glucose cotransporter 2 (SGLT2) inhibitor or a glucagon-like peptide 1 (GLP-1) receptor agonist with proven cardiovascular benefit is recommended. For patients with chronic kidney disease or clinical heart failure and atherosclerotic cardiovascular disease, an SGLT2 inhibitor with proven benefit is recommended. GLP-1 receptor agonists are generally recommended as the first injectable medication.
Plasma concentrations of adiponectin, a novel adipose-specific protein with putative antiatherogenic and antiinflammatory effects, were found to be decreased in Japanese individuals with obesity, type 2 diabetes, and cardiovascular disease, conditions commonly associated with insulin resistance and hyperinsulinemia. To further characterize the relationship between adiponectinemia and adiposity, insulin sensitivity, insulinemia, and glucose tolerance, we measured plasma adiponectin concentrations, body composition (dual-energy x-ray absorptiometry), insulin sensitivity (M, hyperinsulinemic clamp), and glucose tolerance (75-g oral glucose tolerance test) in 23 Caucasians and 121 Pima Indians, a population with a high propensity for obesity and type 2 diabetes. Plasma adiponectin concentration was negatively correlated with percent body fat (r = -0.43), waist-to-thigh ratio (r = -0.46), fasting plasma insulin concentration (r = -0.63), and 2-h glucose concentration (r = -0.38), and positively correlated with M (r = 0.59) (all P < 0.001); all relations were evident in both ethnic groups. In a multivariate analysis, fasting plasma insulin concentration, M, and waist-to-thigh ratio, but not percent body fat or 2-h glucose concentration, were significant independent determinates of adiponectinemia, explaining 47% of the variance (r(2) = 0.47). Differences in adiponectinemia between Pima Indians and Caucasians (7.2 +/- 2.6 vs. 10.2 +/- 4.3 microg/ml, P < 0.0001) and between Pima Indians with normal, impaired, and diabetic glucose tolerance (7.5 +/- 2.7, 6.1 +/- 2.0, 5.5 +/- 1.6 microg/ml, P < 0.0001) remained significant after adjustment for adiposity, but not after additional adjustment for M or fasting insulin concentration. These results confirm that obesity and type 2 diabetes are associated with low plasma adiponectin concentrations in different ethnic groups and indicate that the degree of hypoadiponectinemia is more closely related to the degree of insulin resistance and hyperinsulinemia than to the degree of adiposity and glucose intolerance.
BACKGROUND: Nonalcoholic steatohepatitis is a common liver disease that can progress to cirrhosis. Currently, there is no established treatment for this disease. METHODS: We randomly assigned 247 adults with nonalcoholic steatohepatitis and without diabetes to receive pioglitazone at a dose of 30 mg daily (80 subjects), vitamin E at a dose of 800 IU daily (84 subjects), or placebo (83 subjects), for 96 weeks. The primary outcome was an improvement in histologic features of nonalcoholic steatohepatitis, as assessed with the use of a composite of standardized scores for steatosis, lobular inflammation, hepatocellular ballooning, and fibrosis. Given the two planned primary comparisons, P values of less than 0.025 were considered to indicate statistical significance. RESULTS: Vitamin E therapy, as compared with placebo, was associated with a significantly higher rate of improvement in nonalcoholic steatohepatitis (43% vs. 19%, P=0.001), but the difference in the rate of improvement with pioglitazone as compared with placebo was not significant (34% and 19%, respectively; P=0.04). Serum alanine and aspartate aminotransferase levels were reduced with vitamin E and with pioglitazone, as compared with placebo (P<0.001 for both comparisons), and both agents were associated with reductions in hepatic steatosis (P=0.005 for vitamin E and P<0.001 for pioglitazone) and lobular inflammation (P=0.02 for vitamin E and P=0.004 for pioglitazone) but not with improvement in fibrosis scores (P=0.24 for vitamin E and P=0.12 for pioglitazone). Subjects who received pioglitazone gained more weight than did those who received vitamin E or placebo; the rates of other side effects were similar among the three groups. CONCLUSIONS: Vitamin E was superior to placebo for the treatment of nonalcoholic steatohepatitis in adults without diabetes. There was no benefit of pioglitazone over placebo for the primary outcome; however, significant benefits of pioglitazone were observed for some of the secondary outcomes. (ClinicalTrials.gov number, NCT00063622.)
This document has been approved by the AASLD, the Infectious Diseases Society of America, and the American College of Gastroenterology. These recommendations provide a data-supported approach to establishing guidelines. They are based on the following: (1) a formal review and analysis of the recently published world literature on the topic (Medline search up to September 2008); (2) the American College of Physicians' Manual for Assessing Health Practices and Designing Practice Guidelines;1 (3) guideline policies, including the American Association for the Study of Liver Diseases' (AASLD) Policy on the Development and Use of Practice Guidelines and the American Gastroenterological Association's Policy Statement on the Use of Medical Practice Guidelines;2 and (4) the experience of the authors in regard to hepatitis C. Intended for use by physicians, these recommendations suggest preferred approaches to the diagnostic, therapeutic and preventive aspects of care. They are intended to be flexible, in contrast to standards of care, which are inflexible policies to be followed in every case. Specific recommendations are based on relevant published information. To more fully characterize the quality of evidence supporting recommendations, the Practice Guidelines Committee of the AASLD requires a Class (reflecting benefit versus risk) and Level (assessing strength or certainty) of Evidence to be assigned and reported with each recommendation (Table 1, adapted from the American College of Cardiology and the American Heart association Practice Guidelines).3, 4 AASLD, American Association for the Study of Liver Diseases; ALT, alanine aminotransferase; ANC, absolute neutrophil count; anti-HCV, antibody to HCV; AST, aspartate aminotransferase; CKD, chronic kidney disease; CTP, Child-Turcotte-Pugh; EIA, enzyme immunoassay; ETR, end-of-treatment response; EVR, early virological response; FDA, U.S. Food and Drug Administration; HCV, hepatitis C virus; HIV, human immunodeficiency virus; PCR, polymerase chain reaction; PEG, polyethylene glycol; RVR, rapid virological response; SVR, sustained virological response; ULN, upper limit of normal. The hepatitis C virus (HCV) is a major public health problem and a leading cause of chronic liver disease.5 An estimated 180 million people are infected worldwide.6 In the United States (U.S.), the prevalence of HCV infection between the years 1999 and 2002 was 1.6%, equating to about 4.1 million persons positive for antibody to hepatitis C (anti-HCV), 80% of whom are estimated to be viremic.7 Hepatitis C is the principal cause of death from liver disease and the leading indication for liver transplantation in the U.S.8 Some calculations suggest that mortality related to HCV infection (death from liver failure or hepatocellular carcinoma) will continue to increase over the next two decades.9 The purpose of this document is to provide clinicians with evidence-based approaches to the prevention, diagnosis, and management of HCV infection. The optimal approach to detecting HCV infection is to screen persons for a history of risk of exposure to the virus, and to test selected individuals who have an identifiable risk factor.10 Currently, injection drug use is the primary mode of HCV transmission in the U.S; thus, all persons who use or have used illicit injection drugs in the present or past, even if only once, as well as intranasal drug users who share paraphernalia, should be tested for HCV infection.7, 11, 12 Individuals who have received a blood or blood component transfusion or an organ transplant before 1992 should also be tested. With the introduction of sensitive tests to screen blood donors for HCV antibodies in 1992, transfusion-transmission of HCV has become rare.12, 13 Persons with hemophilia should be tested for HCV infection if blood products were received before 1987, after which time, viral inactivation procedures were implemented.14 Similarly, individuals with unexplained elevations of the aminotransferase levels (alanine and/or aspartate aminotransferase; ALT/AST), those ever on hemodialysis, children born to HCV-infected mothers, or those with human immunodeficiency virus (HIV) infection should be tested for the presence of HCV infection.15-17 Other potential sources of HCV transmission include exposure to an infected sexual partner or multiple sexual partners, exposure among health care workers to HCV-contaminated blood and blood products, and tattooing.12, 15, 18-23 The prevalence of HCV infection is consistently higher among persons with multiple sexual partners, whereas sexual transmission of HCV between monogamous partners is uncommon.11, 18 Thus, although it is prudent to counsel HCV-infected persons to notify their current partners of their HCV status, they should be informed that the risk of sexual transmission is sufficiently low19 that many authorities do not advise the use of barrier protection among monogamous couples.18 Nevertheless, between 1% and 5% of monogamous sexual partners of index HCV cases test positive for anti-HCV. There is no need for HCV-infected persons to limit ordinary household activities except for those that might result in blood exposure, such as sharing a razor or toothbrush. The hepatitis C virus is not transmitted by hugging, kissing, sharing of eating utensils or breastfeeding. Folk medicine practices, including acupuncture and ritual scarification, as well as body piercing, tattooing and commercial barbering are potential modes for transmission of HCV infection when performed without appropriate infection control measures.24-28 Transmission of HCV infection by body piercing is, however, rare and many HCV infected persons who have undergone body piercing acquired their infection by other means.23, 29-33 Therefore, there is no need to routinely test persons who have received tattoos or undergone piercings in the absence of other risk factors, particularly if these procedures have taken place in licensed establishments. Because symptoms are generally absent in individuals with chronic HCV infection, recognition of infection requires risk factor screening, which should be done whenever it is possible to link with appropriate HCV testing and counseling.10 Table 2 outlines the list of persons who should be routinely screened for HCV infection.15 For some groups, such as those with a history of injection drug use or persons with hemophilia, the prevalence of HCV is high (≈90%). For other groups (recipients of blood transfusions prior to 1992), the prevalence is moderate (≈10%). For still others, (persons with needle stick exposure, sexual partners of HCV-infected persons), the prevalence is low (1% to 5%). ○ Persons with HIV infection ○ Persons with hemophilia who received clotting factor concentrates prior to 1987 ○ Persons who have ever been on hemodialysis ○ Persons with unexplained abnormal aminotransferase levels ○ Persons who were notified that they had received blood from a donor who later tested positive for HCV infection ○ Persons who received a transfusion of blood or blood products ○ Persons who received an organ transplant Recommendation 1. As part of a comprehensive health evaluation, all persons should be screened for behaviors that place them at high risk for HCV infection. (Class I, level B). 2. Persons who are at risk should be tested for the presence of HCV infection (Table2) (Class I, level B). Good clinical practice dictates that persons found to be HCV-infected are counseled regarding prevention of spread of the virus to others. Because exposure to infected blood is the primary mode of transmission, it is essential to inform HCV-infected individuals that precautions should be taken to avoid the possibility of exposing others to contact with their blood. This is particularly important for injection drug users who are the leading source of HCV infection, because their transmission route is primarily via sharing of needles and other infected implements. Table 3 outlines the measures to avoid HCV transmission. Recommendation 3. Persons infected with HCV should be counseled on how to avoid HCV transmission to others, as indicated in Table3 (Class I, level C) Two classes of assays are used in the diagnosis and management of HCV infection: serologic assays that detect specific antibody to hepatitis C virus (anti-HCV) and molecular assays that detect viral nucleic acid. These assays have no role in the assessment of disease severity or prognosis. Tests that detect anti-HCV are used both to screen for and to diagnose HCV infection. Anti-HCV can be detected in the serum or plasma using a number of immunoassays. Two enzyme immunoassays (EIAs) are approved by the U.S. Food and Drug Administration (FDA) for clinical use, Abbott HCV EIA 2.0 (Abbott Laboratories, Abbott Park, IL) and ORTHO® HCV Version 3.0 ELISA (Ortho-Clinical Diagnostics, Raritan, NJ), as well as one enhanced chemiluminescence immunoassay (CIA) VITROS® Anti-HCV assay, (Ortho-Clinical Diagnostics, Raritan, NJ). The specificity of current EIAs for anti-HCV is greater than 99%.34 False positive results are more likely to occur when testing is performed among populations where the prevalence of hepatitis C is low. False negative results may occur in the setting of severe immunosuppression such as infection with HIV, solid organ transplant recipients, hypo- or aggammaglobulinemia or in patients on hemodialysis.35-37 The recombinant immunoblot assay, Chiron RIBA HCV 3.0 SIA (Chiron Corporation, Emeryville, CA) is also FDA approved. This assay was originally developed as a more specific, supplemental assay to confirm the results of EIA testing.38, 39 However, specificity is extremely high for third generation EIA results that exceed particular signal/cutoff ratios (e.g., >3.8 for the above mentioned Ortho and Abbott EIA tests). Given the widespread availability of nucleic acid testing, the role for RIBA testing in HCV diagnosis and management has all but disappeared.40, 41 The list of commercial assays available for the detection (qualitative assays) or quantification (quantitative assays) of HCV RNA is shown in Tables 4 and 5. Historically, qualitative assays have been more sensitive than quantitative assays. With the recent availability of real time polymerase chain reaction (PCR)-based assays and transcription-mediated amplification (TMA) assays, with sensitivities of 10-50 IU/mL, there is no longer need for qualitative assays.42, 43 A highly sensitive assay with this lower limit of detection is considered appropriate for monitoring during therapy. All currently available assays have excellent specificity, in the range of 98% to 99%. In 1997, the World Health Organization established the first International standard for HCV RNA nucleic acid technology,44 and the IU rather than viral copies is now the preferred unit to report test results.44, 45 For monitoring purposes, it is important to use the same laboratory test before and during therapy. Genotyping is useful in epidemiological studies and in clinical management for predicting the likelihood of response and determining the optimal duration of therapy. The hepatitis C virus can be classified into at least 6 major genotypes (genotypes 1 to 6) based on a sequence divergence of 30% among isolates.46 Genotype 1 (subtypes 1a and 1b) is the most common in the U.S., followed by genotypes 2 and 3. Less common genotypes (genotypes 4-6) are beginning to be observed more frequently because of the growing cultural diversity within the United States.47 Several commercial assays are available to determine HCV genotypes using direct sequence analysis of the 5′ non-coding region, that include Trugene 5′NC HCV Genotyping kit (Siemens Healthcare Diagnostics Division, Tarrytown, NY), reverse hybridization analysis using genotype specific oligonucleotide probes located in the 5′ non-coding region, INNO-LiPa HCV II, (Innogenetics, Ghent, Belgium), and Versant HCV Genotyping Assay 2.0 (Siemens Healthcare Diagnostics Division, Tarrytown, NY). Incorrect typing among the major genotypes is rare (<3%) and mixed genotypes occur but are uncommon. Occasionally (<5%), tested samples cannot be genotyped. This usually results from low viral levels, issues with the PCR amplification step of the assay, or extreme nucleotide variability within the HCV genome.48 The diagnosis of acute or chronic HCV infection generally requires testing of serum for both antibody to HCV (anti-HCV) and for HCV RNA. A sensitive quantitative HCV RNA assay is recommended for diagnosis because it also provides information on the level of virus which is helpful in management. The differentiation of acute from chronic HCV infection depends on the clinical presentation: namely the presence of symptoms or jaundice, and whether or not there was a prior history of ALT elevation and its duration. After acute exposure, HCV RNA is usually detected in serum before antibody; HCV RNA can be identified as early as 2 weeks following exposure whereas anti-HCV is generally not detectable before 8-12 weeks. These two markers of HCV infection may be present in varying permutations, requiring careful analysis for interpretation (Table 6). One pattern is the identification of both anti-HCV and HCV RNA in a person with recent elevation of the ALT value. This scenario is consistent with either acute HCV infection when there is a recent known risk exposure, with exacerbation of chronic HCV infection, or with an acute hepatitis of another etiology in a patient with chronic HCV infection. Another pattern is the detection of anti-HCV but with a negative test for HCV RNA. This may represent acute HCV infection during a period of transient clearance of HCV RNA, a false positive or negative result or, more commonly, recovery from HCV infection. Re-testing for HCV RNA 4-6 months later is recommended to confirm the resolution of HCV infection. The reverse scenario — a negative anti-HCV test but a positive result for HCV RNA — is compatible with the early stage of acute infection prior to the development of antibody or may represent chronic infection in an immunosuppressed individual. Alternatively, it may represent a false positive HCV RNA result. In all circumstances, re-testing for anti-HCV and HCV RNA in 4-6 months should resolve the issue. Finally, if the patient has raised ALT values but the tests for anti-HCV and HCV RNA are negative, both acute and chronic hepatitis C may be excluded and another diagnosis should be considered. Antibody testing should be repeated in 4-6 months for confirmation purposes. Recommendation 4. Patients suspected of having acute or chronic HCV infection should first be tested for anti-HCV (Class I, Level B.) 5. HCV RNA testing should be performed in: a) Patients with a positive anti-HCV test (Class I, Level B) b) Patients for whom antiviral treatment is being considered, using a sensitive quantitative assay (Class I, Level A) c) Patients with unexplained liver disease whose anti-HCV test is negative and who are immunocompromised or suspected of having acute HCV infection (Class I, Level B). 6. HCV genotyping should be performed in all HCV-infected persons prior to interferon-based treatment in order to plan for the dose and duration of therapy and to estimate the likelihood of response (Class I, Level A) There are three primary reasons for performing a liver biopsy: it provides helpful information on the current status of the liver injury, it identifies features useful in the decision to embark on therapy, and it may reveal advanced fibrosis or cirrhosis that necessitates surveillance for hepatocellular carcinoma (HCC) and/or screening for varices. The biopsy is assessed for grade and stage of the liver injury, but also provides information on other histological features that might have a bearing on liver disease progression.49 The grade defines the extent of necroinflammatory activity, while the stage establishes the extent of fibrosis or the presence of cirrhosis. Several scoring systems have been conceived, the most common being the French METAVIR, the Batts-Ludwig, the International Association for the Study of the Liver (IASL) and the Ishak Scoring systems.50-54 (Table 7). The two more common non-HCV conditions that might affect disease progression and possibly impede treatment response are steatosis49, 55, 56 and excess hepatocellular iron.57 Identifying either of these two features does not preclude initiating treatment, but their presence provides additional information regarding the likelihood of response to treatment.58-60 The liver biopsy has been widely regarded as the "gold standard" for defining the liver disease status, but it has drawbacks that have prompted questions about its value.61, 62 The procedure is not without risks (including pain, bleeding and perforation of other organs),63, 64 it is subject to sampling error,65 it requires special expertise for interpreting the histopathology, it adds cost to medical care, and it is anxiety-provoking for the implicated person. Thus, efforts are underway to seek alternative means of establishing information on the extent of fibrosis by focusing on noninvasive blood marker panels.66 These markers are useful for establishing the two ends of the fibrosis spectrum (minimal fibrosis and cirrhosis) but are less helpful in assessing the mid-ranges of fibrosis or for tracking fibrosis progression.66 The recently developed transient elastography that uses ultrasound and low frequency elastic waves to measure liver elasticity67 has improved the ability to define the extent of fibrosis without a liver biopsy, particularly when combined with other noninvasive markers.68 However, it is not yet ready to replace the liver biopsy since it is not FDA approved, the failure rate is higher in obese patients, and there is now evidence that the transient elastography score can be unexpectedly increased in persons with acute hepatitis who have high necroinflammatory activity but no or minimal fibrosis.69, 70 A liver biopsy may be unnecessary in persons with genotypes 2 and 3 HCV infection, since more than 80% of them achieve a sustained virlogical response (SVR) to standard-of-care treatment. There is, however, an ongoing debate about whether a biopsy is warranted for persons infected with HCV, genotype 1, whose response to such treatment approximates 50% among Caucasians and 30% among African Americans.71-73 Even more uncertain is whether there is need for a liver biopsy in persons infected with the other less common genotypes (4 through 6). Thus, although the liver biopsy was previously regarded as routine for defining the fibrosis stage in persons with genotype 1 infection,62 the issue is now in a state of flux and possible transition. Supporters of a biopsy cite the difficult nature and high cost of current antiviral therapy and are to or treatment if liver minimal to moderate fibrosis stage (Table if the infection is known to have been These individuals are regarded as having liver disease that may not be for their However, treatment is for those with more advanced fibrosis stage (Table be however, that while information from a biopsy is the procedure is not for on treatment. performed and treatment is a common is to the liver biopsy 4 to years later and to treatment should there be evidence of disease The that persons with genotype 1 infection and aminotransferase values not a liver biopsy because they were to have minimal liver and that treatment may be are no longer is now that as many as a of such individuals have and that treatment response is to that of individuals with abnormal serum aminotransferase Therefore, the decision to a liver biopsy should be based on whether treatment is being considered, into the estimated duration of infection and other of liver disease (e.g., the the viral and the to a liver biopsy and to be the biopsy is not performed and treatment not the patient should continue to be at least and a biopsy performed if the aminotransferase values become abnormal and other of liver disease become A liver biopsy should be considered in patients with chronic hepatitis C infection if the patient and health care information regarding fibrosis stage for or to a decision regarding treatment (Class Level B) available noninvasive tests may be useful in defining the presence or absence of advanced fibrosis in persons with chronic hepatitis C infection, but should not replace the liver biopsy in routine clinical practice (Class Level history studies that to of individuals who acute hepatitis C will resolution is more common among infected and than among persons who are when they acute HCV infection has for the infected persons as well as for their the are at risk for progression to cirrhosis and/or the are at risk of the infection through exposure to the The risk of cirrhosis from 5% to over of to studies of and children infected at a and followed for to years report low of 1% to studies of patients to care document higher of to but this may be by to cirrhosis may be in persons who are of who are who are immunosuppressed (e.g., HIV and who more than of although the of with fibrosis progression is Persons with cirrhosis are at risk for the development of over as well as hepatocellular carcinoma (1% to Identifying individuals at risk for disease is the preferred approach is to the of fibrosis on liver biopsy, using a such as the or Persons with no or minimal fibrosis stage and stage have a low risk for and death the next to However, the presence of fibrosis stage Table is an important of progression to cirrhosis and an indication for with HCV can also cause including mixed and is an indication for HCV antiviral therapy of the stage of liver on of Patients with The of therapy is to and death from HCV infection. Because of the of chronic HCV infection over it has been difficult to that therapy of liver treatment are by a virological rather than a clinical can be of serum ALT of HCV RNA from serum by a sensitive and in necroinflammatory score with no in fibrosis Several of virological may to their to treatment. The most important is the sustained virological response as the absence of HCV RNA from serum by a sensitive PCR assay weeks following of therapy (Table This is generally regarded as a although liver has been identified years if cirrhosis at the time of an of virological RVR, rapid virological response of HCV from serum by 4 using a sensitive EVR, early virological response in HCV RNA level to HCV RNA level or HCV RNA negative at treatment SVR, sustained virological response RNA negative weeks after of of HCV RNA in serum after therapy is failure to HCV RNA from serum after weeks of 2 in HCV RNA but still HCV RNA positive at failure to HCV RNA by 2 after of therapy. virus at the of either a or of therapy is to as an end-of-treatment response An does not that an will be but is for it to A rapid virological response as HCV RNA at 4 of treatment, using a sensitive test with a lower limit of detection of IU/mL, a high likelihood of an An early virological response is as a or absence of serum HCV RNA at 12 of therapy with the to achieve an is the most of not an viral is useful for predicting whether or not an is likely to to the of HCV RNA while still on therapy, while virological is the of HCV RNA in serum after treatment is and an was Persons who to serum HCV RNA by at least 2 after weeks of therapy are while those whose HCV RNA levels by but become are to as The currently recommended therapy of chronic HCV infection is the of a and The of this was based the results of three clinical that the of this treatment over standard and not these three of therapy, namely the appropriate dose of the the optimal duration of therapy and the need for a for patients with genotype 1 and genotype 2 and 3 There are two licensed in the United NJ), with a polyethylene to the standard and with a to the standard The of these two of The optimal dose of based on the is to body the dose of used in the was at a of patients with genotype 1 infection that for patients for patients to for patients to and for patients but was more to and in the two U.S. ETR, end-of-treatment response; SVR, sustained virological is at a dose of 180 with to for those who and for those who The the two of an in the more a in the rate as to treatment. A third that the optimal duration of treatment should be based on the viral The established that patients with genotype 1 should be for weeks with standard whereas patients with genotypes 2 and 3 be with low dose for For patients with HCV genotype 4 infection, treatment with for weeks to be the optimal as in a of from another of treatment with a dose of has that weeks duration of therapy is an is these results need to be Patients with genotypes and 6 are in of and to their A recent analysis of the treatment of patients
OBJECTIVE: To evaluate the prevalence and time trends for diagnosed and undiagnosed diabetes, impaired fasting glucose, and impaired glucose tolerance in U.S. adults by age, sex, and race or ethnic group, based on data from the Third National Health and Nutrition Examination Survey, 1988-1994 (NHANES III) and prior Health and Nutrition Examination Surveys (HANESs). RESEARCH DESIGN AND METHODS: NHANES III contained a probability sample of 18,825 U.S. adults > or = 20 years of age who were interviewed to ascertain a medical history of diagnosed diabetes, a subsample of 6,587 adults for whom fasting plasma glucose values were obtained, and a subsample of 2,844 adults between 40 and 74 years of age who received an oral glucose tolerance test. The Second National Health and Nutrition Examination Survey, 1976-1980, and Hispanic HANES used similar procedures to ascertain diabetes. Prevalence was calculated using the 1997 American Diabetes Association fasting plasma glucose criteria and the 1980-1985 World Health Organization (WHO) oral glucose tolerance test criteria. RESULTS: Prevalence of diagnosed diabetes in 1988-1994 was estimated to be 5.1% for U.S. adults > or = 20 years of age (10.2 million people when extrapolated to the 1997 U.S. population). Using American Diabetes Association criteria, the prevalence of undiagnosed diabetes (fasting plasma glucose > or = 126 mg/dl) was 2.7% (5.4 million), and the prevalence of impaired fasting glucose (110 to < 126 mg/dl) was 6.9% (13.4 million). There were similar rates of diabetes for men and women, but the rates for non-Hispanic blacks and Mexican-Americans were 1.6 and 1.9 times the rate for non-Hispanic whites. Based on American Diabetes Association criteria, prevalence of diabetes (diagnosed plus undiagnosed) in the total population of people who were 40-74 years of age increased from 8.9% in the period 1976-1980 to 12.3% by 1988-1994. A similar increase was found when WHO criteria were applied (11.4 and 14.3%). CONCLUSIONS: The high rates of abnormal fasting and postchallenge glucose found in NHANES III, together with the increasing frequency of obesity and sedentary lifestyles in the population, make it likely that diabetes will continue to be a major health problem in the U.S.
Sedentary behaviors are linked to adverse health outcomes, but the total amount of time spent in these behaviors in the United States has not been objectively quantified. The authors evaluated participants from the 2003-2004 National Health and Nutrition Examination Survey aged >/=6 years who wore an activity monitor for up to 7 days. Among 6,329 participants with at least one 10-hour day of monitor wear, the average monitor-wearing time was 13.9 hours/day (standard deviation, 1.9). Overall, participants spent 54.9% of their monitored time, or 7.7 hours/day, in sedentary behaviors. The most sedentary groups in the United States were older adolescents and adults aged >/=60 years, and they spent about 60% of their waking time in sedentary pursuits. Females were more sedentary than males before age 30 years, but this pattern was reversed after age 60 years. Mexican-American adults were significantly less sedentary than other US adults, and White and Black females were similarly sedentary after age 12 years. These data provide the first objective measure of the amount of time spent in sedentary behavior in the US population and indicate that Americans spend the majority of their time in behaviors that expend very little energy.
IMPORTANCE: Previous studies have shown increasing prevalence of diabetes in the United States. New US data are available to estimate prevalence of and trends in diabetes. OBJECTIVE: To estimate the recent prevalence and update US trends in total diabetes, diagnosed diabetes, and undiagnosed diabetes using National Health and Nutrition Examination Survey (NHANES) data. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional surveys conducted between 1988-1994 and 1999-2012 of nationally representative samples of the civilian, noninstitutionalized US population; 2781 adults from 2011-2012 were used to estimate recent prevalence and an additional 23,634 adults from 1988-2010 were used to estimate trends. MAIN OUTCOMES AND MEASURES: The prevalence of diabetes was defined using a previous diagnosis of diabetes or, if diabetes was not previously diagnosed, by (1) a hemoglobin A1c level of 6.5% or greater or a fasting plasma glucose (FPG) level of 126 mg/dL or greater (hemoglobin A1c or FPG definition) or (2) additionally including 2-hour plasma glucose (2-hour PG) level of 200 mg/dL or greater (hemoglobin A1c, FPG, or 2-hour PG definition). Prediabetes was defined as a hemoglobin A1c level of 5.7% to 6.4%, an FPG level of 100 mg/dL to 125 mg/dL, or a 2-hour PG level of 140 mg/dL to 199 mg/dL. RESULTS: In the overall 2011-2012 population, the unadjusted prevalence (using the hemoglobin A1c, FPG, or 2-hour PG definitions for diabetes and prediabetes) was 14.3% (95% CI, 12.2%-16.8%) for total diabetes, 9.1% (95% CI, 7.8%-10.6%) for diagnosed diabetes, 5.2% (95% CI, 4.0%-6.9%) for undiagnosed diabetes, and 38.0% (95% CI, 34.7%-41.3%) for prediabetes; among those with diabetes, 36.4% (95% CI, 30.5%-42.7%) were undiagnosed. The unadjusted prevalence of total diabetes (using the hemoglobin A1c or FPG definition) was 12.3% (95% CI, 10.8%-14.1%); among those with diabetes, 25.2% (95% CI, 21.1%-29.8%) were undiagnosed. Compared with non-Hispanic white participants (11.3% [95% CI, 9.0%-14.1%]), the age-standardized prevalence of total diabetes (using the hemoglobin A1c, FPG, or 2-hour PG definition) was higher among non-Hispanic black participants (21.8% [95% CI, 17.7%-26.7%]; P < .001), non-Hispanic Asian participants (20.6% [95% CI, 15.0%-27.6%]; P = .007), and Hispanic participants (22.6% [95% CI, 18.4%-27.5%]; P < .001). The age-standardized percentage of cases that were undiagnosed was higher among non-Hispanic Asian participants (50.9% [95% CI, 38.3%-63.4%]; P = .004) and Hispanic participants (49.0% [95% CI, 40.8%-57.2%]; P = .02) than all other racial/ethnic groups. The age-standardized prevalence of total diabetes (using the hemoglobin A1c or FPG definition) increased from 9.8% (95% CI, 8.9%-10.6%) in 1988-1994 to 10.8% (95% CI, 9.5%-12.0%) in 2001-2002 to 12.4% (95% CI, 10.8%-14.2%) in 2011-2012 (P < .001 for trend) and increased significantly in every age group, in both sexes, in every racial/ethnic group, by all education levels, and in all poverty income ratio tertiles. CONCLUSIONS AND RELEVANCE: In 2011-2012, the estimated prevalence of diabetes was 12% to 14% among US adults, depending on the criteria used, with a higher prevalence among participants who were non-Hispanic black, non-Hispanic Asian, and Hispanic. Between 1988-1994 and 2011-2012, the prevalence of diabetes increased in the overall population and in all subgroups evaluated.
BACKGROUND: Restricting protein intake and controlling hypertension delay the progression of renal disease in animals. We tested these interventions in 840 patients with various chronic renal diseases. METHODS: In study 1, 585 patients with glomerular filtration rates of 25 to 55 ml per minute per 1.73 m2 of body-surface area were randomly assigned to a usual-protein diet or a low-protein diet (1.3 or 0.58 g of protein per kilogram of body weight per day) and to a usual- or a low-blood-pressure group (mean arterial pressure, 107 or 92 mm Hg). In study 2, 255 patients with glomerular filtration rates of 13 to 24 ml per minute per 1.73 m2 were randomly assigned to the low-protein diet (0.58 g per kilogram per day) or a very-low-protein diet (0.28 g per kilogram per day) with a keto acid-amino acid supplement, and a usual- or a low-blood-pressure group (same values as those in study 1). An 18-to-45-month follow-up was planned, with monthly evaluations of the patients. RESULTS: The mean follow-up was 2.2 years. In study 1, the projected mean decline in the glomerular filtration rate at three years did not differ significantly between the diet groups or between the blood-pressure groups. As compared with the usual-protein group and the usual-blood-pressure group, the low-protein group and the low-blood-pressure group had a more rapid decline in the glomerular filtration rate during the first four months after randomization and a slower decline thereafter. In study 2, the very-low-protein group had a marginally slower decline in the glomerular filtration rate than did the low-protein group (P = 0.07). There was no delay in the time to the occurrence of end-stage renal disease or death. In both studies, patients in the low-blood-pressure group who had more pronounced proteinuria at base line had a significantly slower rate of decline in the glomerular filtration rate. CONCLUSIONS: Among patients with moderate renal insufficiency, the slower decline in renal function that started four months after the introduction of a low-protein diet suggests a small benefit of this dietary intervention. Among patients with more severe renal insufficiency, a very-low-protein diet, as compared with a low-protein diet, did not significantly slow the progression of renal disease.
[3H]CP 55,940, a radiolabeled synthetic cannabinoid, which is 10-100 times more potent in vivo than delta 9-tetrahydrocannabinol, was used to characterize and localize a specific cannabinoid receptor in brain sections. The potencies of a series of natural and synthetic cannabinoids as competitors of [3H]CP 55,940 binding correlated closely with their relative potencies in several biological assays, suggesting that the receptor characterized in our in vitro assay is the same receptor that mediates behavioral and pharmacological effects of cannabinoids, including human subjective experience. Autoradiography of cannabinoid receptors in brain sections from several mammalian species, including human, reveals a unique and conserved distribution; binding is most dense in outflow nuclei of the basal ganglia--the substantia nigra pars reticulata and globus pallidus--and in the hippocampus and cerebellum. Generally high densities in forebrain and cerebellum implicate roles for cannabinoids in cognition and movement. Sparse densities in lower brainstem areas controlling cardiovascular and respiratory functions may explain why high doses of delta 9-tetrahydrocannabinol are not lethal.
Expected and observed effects of volume exclusion on the free energy of rigid and flexible macromolecules in crowded and confined systems, and consequent effects of crowding and confinement on macromolecular reaction rates and equilibria are summarized. Findings from relevant theoretical/simulation and experimental literature published from 2004 onward are reviewed. Additional complexity arising from the heterogeneity of local environments in biological media, and the presence of nonspecific interactions between macromolecules over and above steric repulsion, are discussed. Theoretical and experimental approaches to the characterization of crowding- and confinement-induced effects in systems approaching the complexity of living organisms are suggested.
Multiple endocrine neoplasia-type 1 (MEN1) is an autosomal dominant familial cancer syndrome characterized by tumors in parathyroids, enteropancreatic endocrine tissues, and the anterior pituitary. DNA sequencing from a previously identified minimal interval on chromosome 11q13 identified several candidate genes, one of which contained 12 different frameshift, nonsense, missense, and in-frame deletion mutations in 14 probands from 15 families. The MEN1 gene contains 10 exons and encodes a ubiquitously expressed 2.8-kilobase transcript. The predicted 610-amino acid protein product, termed menin, exhibits no apparent similarities to any previously known proteins. The identification of MEN1 will enable improved understanding of the mechanism of endocrine tumorigenesis and should facilitate early diagnosis.
The Human Microbiome Project (HMP), funded as an initiative of the NIH Roadmap for Biomedical Research (http://nihroadmap.nih.gov), is a multi-component community resource. The goals of the HMP are: (1) to take advantage of new, high-throughput technologies to characterize the human microbiome more fully by studying samples from multiple body sites from each of at least 250 "normal" volunteers; (2) to determine whether there are associations between changes in the microbiome and health/disease by studying several different medical conditions; and (3) to provide both a standardized data resource and new technological approaches to enable such studies to be undertaken broadly in the scientific community. The ethical, legal, and social implications of such research are being systematically studied as well. The ultimate objective of the HMP is to demonstrate that there are opportunities to improve human health through monitoring or manipulation of the human microbiome. The history and implementation of this new program are described here.
The development of the microbiome from infancy to childhood is dependent on a range of factors, with microbial–immune crosstalk during this time thought to be involved in the pathobiology of later life diseases1–9 such as persistent islet autoimmunity and type 1 diabetes10–12. However, to our knowledge, no studies have performed extensive characterization of the microbiome in early life in a large, multi-centre population. Here we analyse longitudinal stool samples from 903 children between 3 and 46 months of age by 16S rRNA gene sequencing (n = 12,005) and metagenomic sequencing (n = 10,867), as part of the The Environmental Determinants of Diabetes in the Young (TEDDY) study. We show that the developing gut microbiome undergoes three distinct phases of microbiome progression: a developmental phase (months 3–14), a transitional phase (months 15–30), and a stable phase (months 31–46). Receipt of breast milk, either exclusive or partial, was the most significant factor associated with the microbiome structure. Breastfeeding was associated with higher levels of Bifidobacterium species (B. breve and B. bifidum), and the cessation of breast milk resulted in faster maturation of the gut microbiome, as marked by the phylum Firmicutes. Birth mode was also significantly associated with the microbiome during the developmental phase, driven by higher levels of Bacteroides species (particularly B. fragilis) in infants delivered vaginally. Bacteroides was also associated with increased gut diversity and faster maturation, regardless of the birth mode. Environmental factors including geographical location and household exposures (such as siblings and furry pets) also represented important covariates. A nested case–control analysis revealed subtle associations between microbial taxonomy and the development of islet autoimmunity or type 1 diabetes. These data determine the structural and functional assembly of the microbiome in early life and provide a foundation for targeted mechanistic investigation into the consequences of microbial–immune crosstalk for long-term health. Metagenomic sequencing analysis of stool samples from 903 children as part of the TEDDY study shows that breastfeeding was the most important factor associated with microbiome structure, and the cessation of breast milk resulted in faster maturation of the gut microbiome.