Merck Biopharma Co., Ltd. (Japan)

Abstract: We present the derivation of a new molecular mechanical force field for simulating the structures, conformational energies, and interaction energies of proteins, nucleic acids, and many related organic molecules in condensed phases. This effective two-body force field is the successor to the Weiner et al. force field and was developed with some of the same philosophies, such as the use of a simple diagonal potential function and electrostatic potential fit atom centered charges. The need for a 10-12 function for representing hydrogen bonds is no longer necessary due to the improved performance of the new charge model and new van der Waals parameters. These new charges are determined using a 6-31G * basis set and restrained electrostatic potential (RESP) fitting and have been shown to reproduce interaction energies, free energies of solvation, and conformational energies of simple small molecules to a good degree of accuracy. Furthermore, the new RESP charges exhibit less variability as a function of the molecular conformation used in the charge determination. The new van der Waals parameters have been derived from liquid simulations and include hydrogen parameters which take into account the effects of any geminal electronegative atoms. The bonded parameters developed by Weiner et al. were modified as necessary to reproduce experimental vibrational frequencies and structures. Most of the simple dihedral parameters have been retained from Weiner et al., but a complex set of 4 and yj parameters which do a good job of reproducing the energies of the low-energy conformations of glycyl and alanyl dipeptides has been developed for the peptide backbone.

Metformin is a widely used drug for treatment of type 2 diabetes with no defined cellular mechanism of action. Its glucose-lowering effect results from decreased hepatic glucose production and increased glucose utilization. Metformin's beneficial effects on circulating lipids have been linked to reduced fatty liver. AMP-activated protein kinase (AMPK) is a major cellular regulator of lipid and glucose metabolism. Here we report that metformin activates AMPK in hepatocytes; as a result, acetyl-CoA carboxylase (ACC) activity is reduced, fatty acid oxidation is induced, and expression of lipogenic enzymes is suppressed. Activation of AMPK by metformin or an adenosine analogue suppresses expression of SREBP-1, a key lipogenic transcription factor. In metformin-treated rats, hepatic expression of SREBP-1 (and other lipogenic) mRNAs and protein is reduced; activity of the AMPK target, ACC, is also reduced. Using a novel AMPK inhibitor, we find that AMPK activation is required for metformin's inhibitory effect on glucose production by hepatocytes. In isolated rat skeletal muscles, metformin stimulates glucose uptake coincident with AMPK activation. Activation of AMPK provides a unified explanation for the pleiotropic beneficial effects of this drug; these results also suggest that alternative means of modulating AMPK should be useful for the treatment of metabolic disorders.

CONTEXT: Although cholesterol-reducing treatment has been shown to reduce fatal and nonfatal coronary disease in patients with coronary heart disease (CHD), it is unknown whether benefit from the reduction of low-density lipoprotein cholesterol (LDL-C) in patients without CHD extends to individuals with average serum cholesterol levels, women, and older persons. OBJECTIVE: To compare lovastatin with placebo for prevention of the first acute major coronary event in men and women without clinically evident atherosclerotic cardiovascular disease with average total cholesterol (TC) and LDL-C levels and below-average high-density lipoprotein cholesterol (HDL-C) levels. DESIGN: A randomized, double-blind, placebo-controlled trial. SETTING: Outpatient clinics in Texas. PARTICIPANTS: A total of 5608 men and 997 women with average TC and LDL-C and below-average HDL-C (as characterized by lipid percentiles for an age- and sex-matched cohort without cardiovascular disease from the National Health and Nutrition Examination Survey [NHANES] III). Mean (SD) TC level was 5.71 (0.54) mmol/L (221 [21] mg/dL) (51 st percentile), mean (SD) LDL-C level was 3.89 (0.43) mmol/L (150 [17] mg/dL) (60th percentile), mean (SD) HDL-C level was 0.94 (0.14) mmol/L (36 [5] mg/dL) for men and 1.03 (0.14) mmol/L (40 [5] mg/dL) for women (25th and 16th percentiles, respectively), and median (SD) triglyceride levels were 1.78 (0.86) mmol/L (158 [76] mg/dL) (63rd percentile). INTERVENTION: Lovastatin (20-40 mg daily) or placebo in addition to a low-saturated fat, low-cholesterol diet. MAIN OUTCOME MEASURES: First acute major coronary event defined as fatal or nonfatal myocardial infarction, unstable angina, or sudden cardiac death. RESULTS: After an average follow-up of 5.2 years, lovastatin reduced the incidence of first acute major coronary events (1 83 vs 116 first events; relative risk [RR], 0.63; 95% confidence interval [CI], 0.50-0.79; P<.001), myocardial infarction (95 vs 57 myocardial infarctions; RR, 0.60; 95% CI, 0.43-0.83; P=.002), unstable angina (87 vs 60 first unstable angina events; RR, 0.68; 95% CI, 0.49-0.95; P=.02), coronary revascularization procedures (157 vs 106 procedures; RR, 0.67; 95% CI, 0.52-0.85; P=.001), coronary events (215 vs 163 coronary events; RR, 0.75; 95% CI, 0.61-0.92; P =.006), and cardiovascular events (255 vs 194 cardiovascular events; RR, 0.75; 95% CI, 0.62-0.91; P = .003). Lovastatin (20-40 mg daily) reduced LDL-C by 25% to 2.96 mmol/L (115 mg/dL) and increased HDL-C by 6% to 1.02 mmol/L (39 mg/dL). There were no clinically relevant differences in safety parameters between treatment groups. CONCLUSIONS: Lovastatin reduces the risk for the first acute major coronary event in men and women with average TC and LDL-C levels and below-average HDL-C levels. These findings support the inclusion of HDL-C in risk-factor assessment, confirm the benefit of LDL-C reduction to a target goal, and suggest the need for reassessment of the National Cholesterol Education Program guidelines regarding pharmacological intervention.

OBJECTIVE: This technical report describes the procedures involved in developing recommendations on the management of childhood obstructive sleep apnea syndrome (OSAS). METHODS: The literature from 1999 through 2011 was evaluated. RESULTS AND CONCLUSIONS: A total of 3166 titles were reviewed, of which 350 provided relevant data. Most articles were level II through IV. The prevalence of OSAS ranged from 0% to 5.7%, with obesity being an independent risk factor. OSAS was associated with cardiovascular, growth, and neurobehavioral abnormalities and possibly inflammation. Most diagnostic screening tests had low sensitivity and specificity. Treatment of OSAS resulted in improvements in behavior and attention and likely improvement in cognitive abilities. Primary treatment is adenotonsillectomy (AT). Data were insufficient to recommend specific surgical techniques; however, children undergoing partial tonsillectomy should be monitored for possible recurrence of OSAS. Although OSAS improved postoperatively, the proportion of patients who had residual OSAS ranged from 13% to 29% in low-risk populations to 73% when obese children were included and stricter polysomnographic criteria were used. Nevertheless, OSAS may improve after AT even in obese children, thus supporting surgery as a reasonable initial treatment. A significant number of obese patients required intubation or continuous positive airway pressure (CPAP) postoperatively, which reinforces the need for inpatient observation. CPAP was effective in the treatment of OSAS, but adherence is a major barrier. For this reason, CPAP is not recommended as first-line therapy for OSAS when AT is an option. Intranasal steroids may ameliorate mild OSAS, but follow-up is needed. Data were insufficient to recommend rapid maxillary expansion.

All coelenterate fluorescent proteins cloned to date display some form of quaternary structure, including the weak tendency of Aequorea green fluorescent protein (GFP) to dimerize, the obligate dimerization of Renilla GFP, and the obligate tetramerization of the red fluorescent protein from Discosoma (DsRed). Although the weak dimerization of Aequorea GFP has not impeded its acceptance as an indispensable tool of cell biology, the obligate tetramerization of DsRed has greatly hindered its use as a genetically encoded fusion tag. We present here the stepwise evolution of DsRed to a dimer and then either to a genetic fusion of two copies of the protein, i.e., a tandem dimer, or to a true monomer designated mRFP1 (monomeric red fluorescent protein). Each subunit interface was disrupted by insertion of arginines, which initially crippled the resulting protein, but red fluorescence could be rescued by random and directed mutagenesis totaling 17 substitutions in the dimer and 33 in mRFP1. Fusions of the gap junction protein connexin43 to mRFP1 formed fully functional junctions, whereas analogous fusions to the tetramer and dimer failed. Although mRFP1 has somewhat lower extinction coefficient, quantum yield, and photostability than DsRed, mRFP1 matures >10 times faster, so that it shows similar brightness in living cells. In addition, the excitation and emission peaks of mRFP1, 584 and 607 nm, are approximately 25 nm red-shifted from DsRed, which should confer greater tissue penetration and spectral separation from autofluorescence and other fluorescent proteins.

BACKGROUND: Lenvatinib in combination with pembrolizumab or everolimus has activity against advanced renal cell carcinoma. The efficacy of these regimens as compared with that of sunitinib is unclear. METHODS: In this phase 3 trial, we randomly assigned (in a 1:1:1 ratio) patients with advanced renal cell carcinoma and no previous systemic therapy to receive lenvatinib (20 mg orally once daily) plus pembrolizumab (200 mg intravenously once every 3 weeks), lenvatinib (18 mg orally once daily) plus everolimus (5 mg orally once daily), or sunitinib (50 mg orally once daily, alternating 4 weeks receiving treatment and 2 weeks without treatment). The primary end point was progression-free survival, as assessed by an independent review committee in accordance with Response Evaluation Criteria in Solid Tumors, version 1.1. Overall survival and safety were also evaluated. RESULTS: A total of 1069 patients were randomly assigned to receive lenvatinib plus pembrolizumab (355 patients), lenvatinib plus everolimus (357), or sunitinib (357). Progression-free survival was longer with lenvatinib plus pembrolizumab than with sunitinib (median, 23.9 vs. 9.2 months; hazard ratio for disease progression or death, 0.39; 95% confidence interval [CI], 0.32 to 0.49; P<0.001) and was longer with lenvatinib plus everolimus than with sunitinib (median, 14.7 vs. 9.2 months; hazard ratio, 0.65; 95% CI, 0.53 to 0.80; P<0.001). Overall survival was longer with lenvatinib plus pembrolizumab than with sunitinib (hazard ratio for death, 0.66; 95% CI, 0.49 to 0.88; P = 0.005) but was not longer with lenvatinib plus everolimus than with sunitinib (hazard ratio, 1.15; 95% CI, 0.88 to 1.50; P = 0.30). Grade 3 or higher adverse events emerged or worsened during treatment in 82.4% of the patients who received lenvatinib plus pembrolizumab, 83.1% of those who received lenvatinib plus everolimus, and 71.8% of those who received sunitinib. Grade 3 or higher adverse events occurring in at least 10% of the patients in any group included hypertension, diarrhea, and elevated lipase levels. CONCLUSIONS: Lenvatinib plus pembrolizumab was associated with significantly longer progression-free survival and overall survival than sunitinib. (Funded by Eisai and Merck Sharp and Dohme; CLEAR ClinicalTrials.gov number, NCT02811861.).

Amyloid precursor protein (APP) is endoproteolytically processed by BACE1 and gamma-secretase to release amyloid peptides (Abeta40 and 42) that aggregate to form senile plaques in the brains of patients with Alzheimer's disease (AD). The C-terminus of Abeta40/42 is generated by gamma-secretase, whose activity is dependent upon presenilin (PS 1 or 2). Missense mutations in PS1 (and PS2) occur in patients with early-onset familial AD (FAD), and previous studies in transgenic mice and cultured cell models demonstrated that FAD-PS1 variants shift the ratio of Abeta40 : 42 to favor Abeta42. One hypothesis to explain this outcome is that mutant PS alters the specificity of gamma-secretase to favor production of Abeta42 at the expense of Abeta40. To test this hypothesis in vivo, we studied Abeta40 and 42 levels in a series of transgenic mice that co-express the Swedish mutation of APP (APPswe) with two FAD-PS1 variants that differentially accelerate amyloid pathology in the brain. We demonstrate a direct correlation between the concentration of Abeta42 and the rate of amyloid deposition. We further show that the shift in Abeta42 : 40 ratios associated with the expression of FAD-PS1 variants is due to a specific elevation in the steady-state levels of Abeta42, while maintaining a constant level of Abeta40. These data suggest that PS1 variants do not simply alter the preferred cleavage site for gamma-secretase, but rather that they have more complex effects on the regulation of gamma-secretase and its access to substrates.

Osteoclasts, the cells that resorb bone, develop from hematopoietic precursors of the bone marrow under the control of factors produced in their microenvironment. The cytokine interleukin-6 can promote hematopoiesis and osteoclastogenesis. Interleukin-6 production by bone and marrow stromal cells is suppressed by 17 beta-estradiol in vitro. In mice, estrogen loss (ovariectomy) increased the number of colony-forming units for granulocytes and macrophages, enhanced osteoclast development in ex vivo cultures of marrow, and increased the number of osteoclasts in trabecular bone. These changes were prevented by 17 beta-estradiol or an antibody to interleukin-6. Thus, estrogen loss results in an interleukin-6-mediated stimulation of osteoclastogenesis, which suggests a mechanism for the increased bone resorption in postmenopausal osteoporosis.

CONTEXT: The optimal duration of treatment of women with postmenopausal osteoporosis is uncertain. OBJECTIVE: To compare the effects of discontinuing alendronate treatment after 5 years vs continuing for 10 years. DESIGN AND SETTING: Randomized, double-blind trial conducted at 10 US clinical centers that participated in the Fracture Intervention Trial (FIT). PARTICIPANTS: One thousand ninety-nine postmenopausal women who had been randomized to alendronate in FIT, with a mean of 5 years of prior alendronate treatment. INTERVENTION: Randomization to alendronate, 5 mg/d (n = 329) or 10 mg/d (n = 333), or placebo (n = 437) for 5 years (1998-2003). MAIN OUTCOME MEASURES: The primary outcome measure was total hip bone mineral density (BMD); secondary measures were BMD at other sites and biochemical markers of bone remodeling. An exploratory outcome measure was fracture incidence. RESULTS: Compared with continuing alendronate, switching to placebo for 5 years resulted in declines in BMD at the total hip (-2.4%; 95% confidence interval [CI], -2.9% to -1.8%; P<.001) and spine (-3.7%; 95% CI, -4.5% to -3.0%; P<.001), but mean levels remained at or above pretreatment levels 10 years earlier. Similarly, those discontinuing alendronate had increased serum markers of bone turnover compared with continuing alendronate: 55.6% (P<.001) for C-telopeptide of type 1 collagen, 59.5% (P < .001) for serum n = propeptide of type 1 collagen, and 28.1% (P<.001) for bone-specific alkaline phosphatase, but after 5 years without therapy, bone marker levels remained somewhat below pretreatment levels 10 years earlier. After 5 years, the cumulative risk of nonvertebral fractures (RR, 1.00; 95% CI, 0.76-1.32) was not significantly different between those continuing (19%) and discontinuing (18.9%) alendronate. Among those who continued, there was a significantly lower risk of clinically recognized vertebral fractures (5.3% for placebo and 2.4% for alendronate; RR, 0.45; 95% CI, 0.24-0.85) but no significant reduction in morphometric vertebral fractures (11.3% for placebo and 9.8% for alendronate; RR, 0.86; 95% CI, 0.60-1.22). A small sample of 18 transilial bone biopsies did not show any qualitative abnormalities, with bone turnover (double labeling) seen in all specimens. CONCLUSIONS: Women who discontinued alendronate after 5 years showed a moderate decline in BMD and a gradual rise in biochemical markers but no higher fracture risk other than for clinical vertebral fractures compared with those who continued alendronate. These results suggest that for many women, discontinuation of alendronate for up to 5 years does not appear to significantly increase fracture risk. However, women at very high risk of clinical vertebral fractures may benefit by continuing beyond 5 years. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT 00398931.

Growth factors activate mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinases (ERKs) and Jun kinases (JNKs). Although the signaling cascade from growth factor receptors to ERKs is relatively well understood, the pathway leading to JNK activation is more obscure. Activation of JNK by epidermal growth factor (EGF) or nerve growth factor (NGF) was dependent on H-Ras activation, whereas JNK activation by tumor necrosis factor alpha (TNF-alpha) was Ras-independent. Ras activates two protein kinases, Raf-1 and MEK (MAPK, or ERK, kinase) kinase (MEKK). Raf-1 contributes directly to ERK activation but not to JNK activation, whereas MEKK participated in JNK activation but caused ERK activation only after overexpression. These results demonstrate the existence of two distinct Ras-dependent MAPK cascades--one initiated by Raf-1 leading to ERK activation, and the other initiated by MEKK leading to JNK activation.

Functional subsets of human T cells were delineated by analyzing patterns of lymphokines produced by clones from individuals with leprosy and by T cell clones of known function. CD4 clones from individuals with strong cell-mediated immunity produced predominantly interferon-gamma, whereas those clones that enhanced antibody formation produced interleukin-4. CD8 cytotoxic T cells secreted interferon-gamma. Interleukin-4 was produced by CD8 T suppressor clones from immunologically unresponsive individuals with leprosy and was found to be necessary for suppression in vitro. Both the classic reciprocal relation between antibody formation and cell-mediated immunity and resistance or susceptibility to certain infections may be explained by T cell subsets differing in patterns of lymphokine production.

CONTEXT: Although postmenopausal hormone replacement therapy (HRT) is widely used in the United States, new evidence about its benefits and harms requires reconsideration of its use for the primary prevention of chronic conditions. OBJECTIVE: To assess the benefits and harms of HRT for the primary prevention of cardiovascular disease, thromboembolism, osteoporosis, cancer, dementia, and cholecystitis by reviewing the literature, conducting meta-analyses, and calculating outcome rates. DATA SOURCES: All relevant English-language studies were identified in MEDLINE (1966-2001), HealthSTAR (1975-2001), Cochrane Library databases, and reference lists of key articles. Recent results of the Women's Health Initiative (WHI) and the Heart and Estrogen/progestin Replacement Study (HERS) are included for reported outcomes. STUDY SELECTION AND DATA EXTRACTION: We used all published studies of HRT if they contained a comparison group of HRT nonusers and reported data relating to HRT use and clinical outcomes of interest. Studies were excluded if the population was selected according to prior events or presence of conditions associated with higher risks for targeted outcomes. DATA SYNTHESIS: Meta-analyses of observational studies indicated summary relative risks (RRs) for coronary heart disease (CHD) incidence and mortality that were significantly reduced among current HRT users only, although risk for incidence was not reduced when only studies that controlled for socioeconomic status were included. The WHI reported increased CHD events (hazard ratio [HR], 1.29; 95% confidence interval [CI], 1.02-1.63). Stroke incidence but not mortality was significantly increased among HRT users in the meta-analysis and the WHI. The meta-analysis indicated that risk was significantly elevated for thromboembolic stroke (RR, 1.20; 95% CI, 1.01-1.40) but not subarachnoid or intracerebral stroke. Risk of venous thromboembolism among current HRT users was increased overall (RR, 2.14; 95% CI, 1.64-2.81) and was highest during the first year of use (RR, 3.49; 95% CI, 2.33-5.59) according to a meta-analysis of 12 studies. Protection against osteoporotic fractures is supported by a meta-analysis of 22 estrogen trials, cohort studies, results of the WHI, and trials with bone density outcomes. Current estrogen users have an increased risk of breast cancer that increases with duration of use. Endometrial cancer incidence, but not mortality, is increased with unopposed estrogen use but not with estrogen with progestin. A meta-analysis of 18 observational studies showed a 20% reduction in colon cancer incidence among women who had ever used HRT (RR, 0.80; 95% CI, 0.74-0.86), a finding supported by the WHI. Women symptomatic from menopause had improvement in certain aspects of cognition. Current studies of estrogen and dementia are not definitive. In a cohort study, current HRT users had an age-adjusted RR for cholecystitis of 1.8 (95% CI, 1.6-2.0), increasing to 2.5 (95% CI, 2.0-2.9) after 5 years of use. CONCLUSIONS: Benefits of HRT include prevention of osteoporotic fractures and colorectal cancer, while prevention of dementia is uncertain. Harms include CHD, stroke, thromboembolic events, breast cancer with 5 or more years of use, and cholecystitis.

A randomized, multicentre, open-label, phase II study compared temozolomide (TMZ), an oral second-generation alkylating agent, and procarbazine (PCB) in 225 patients with glioblastoma multiforme at first relapse. Primary objectives were to determine progression-free survival (PFS) at 6 months and safety for TMZ and PCB in adult patients who failed conventional treatment. Secondary objectives were to assess overall survival and health-related quality of life (HRQL). TMZ was given orally at 200 mg/m(2)/day or 150 mg/m(2)/day (prior chemotherapy) for 5 days, repeated every 28 days. PCB was given orally at 150 mg/m(2)/day or 125 mg/m(2)/day (prior chemotherapy) for 28 days, repeated every 56 days. HRQL was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30 [+3]) and the Brain Cancer Module 20 (BCM20). The 6-month PFS rate for patients who received TMZ was 21%, which met the protocol objective. The 6-month PFS rate for those who received PCB was 8% (P = 0.008, for the comparison). Overall PFS significantly improved with TMZ, with a median PFS of 12.4 weeks in the TMZ group and 8.32 weeks in the PCB group (P = 0.0063). The 6-month overall survival rate for TMZ patients was 60% vs. 44% for PCB patients (P = 0.019). Freedom from disease progression was associated with maintenance of HRQL, regardless of treatment received. TMZ had an acceptable safety profile; most adverse events were mild or moderate in severity.

MicroRNAs (miRNAs) are a class of small noncoding RNAs that have important regulatory roles in multicellular organisms. The public miRNA database contains 321 human miRNA sequences, 234 of which have been experimentally verified. To explore the possibility that additional miRNAs are present in the human genome, we have developed an experimental approach called miRNA serial analysis of gene expression (miRAGE) and used it to perform the largest experimental analysis of human miRNAs to date. Sequence analysis of 273,966 small RNA tags from human colorectal cells allowed us to identify 200 known mature miRNAs, 133 novel miRNA candidates, and 112 previously uncharacterized miRNA* forms. To aid in the evaluation of candidate miRNAs, we disrupted the Dicer locus in three human colorectal cancer cell lines and examined known and novel miRNAs in these cells. These studies suggest that the human genome contains many more miRNAs than currently identified and provide an approach for the large-scale experimental cloning of novel human miRNAs in human tissues.

BACKGROUND: Migraine is a common disabling disease but its economic burden has not been adequately quantified. OBJECTIVE: To estimate the burden of migraine in the United States with respect to disability and economic costs. METHODS: The following data sources were used: published data, the Baltimore County Migraine Study, MEDSTAT's MarketScan medical claims data set, and statistics from the Census Bureau and the Bureau of Labor Statistics. Disability was expressed as bedridden days. Charges for migraine-related treatment were used as direct cost inputs. The human capital approach was used in the estimation of indirect costs. RESULTS: Migraineurs required 3.8 bed rest days for men and 5.6 days for women each year, resulting in a total of 112 million bedridden days. Migraine costs American employers about $13 billion a year because of missed workdays and impaired work function; close to $8 billion was directly due to missed workdays. Patients of both sexes aged 30 to 49 years incurred higher indirect costs compared with younger or older employed patients. Annual direct medical costs for migraine care were about $1 billion and about $100 was spent per diagnosed patient. Physician office visits accounted for about 60% of all costs; in contrast, emergency department visits contributed less than 1% of the direct costs. CONCLUSIONS: The economic burden of migraine predominantly falls on patients and their employers in the form of bedridden days and lost productivity. Various screening and treatment regimens should be evaluated to identify opportunities to reduce the disease burden.

Neurobiological factors contributing to violence in humans remain poorly understood. One approach to this question is examining allelic variation in the X-linked monoamine oxidase A (MAOA) gene, previously associated with impulsive aggression in animals and humans. Here, we have studied the impact of a common functional polymorphism in MAOA on brain structure and function assessed with MRI in a large sample of healthy human volunteers. We show that the low expression variant, associated with increased risk of violent behavior, predicted pronounced limbic volume reductions and hyperresponsive amygdala during emotional arousal, with diminished reactivity of regulatory prefrontal regions, compared with the high expression allele. In men, the low expression allele is also associated with changes in orbitofrontal volume, amygdala and hippocampus hyperreactivity during aversive recall, and impaired cingulate activation during cognitive inhibition. Our data identify differences in limbic circuitry for emotion regulation and cognitive control that may be involved in the association of MAOA with impulsive aggression, suggest neural systems-level effects of X-inactivation in human brain, and point toward potential targets for a biological approach toward violence.

In the matched analysis of an observational study, confounding on covariates X is addressed by comparing members of a distinguished group (Z = 1) to controls (Z = 0) only when they belong to the same matched set. The better matchings, therefore, are those whose matched sets exhibit both dispersion in Z and uniformity in X. For dispersion in Z, pair matching is best, creating matched sets that are equally balanced between the groups; but actual data place limits, often severe limits, on matched pairs' uniformity in X. At the other extreme is full matching, the matched sets of which are as uniform in X as can be, while often so poorly dispersed in Z as to sacrifice efficiency.This article presents an algorithm for exploring the intermediate territory. Given requirements on matched sets' uniformity in X and dispersion in Z, the algorithm first decides the requirements' feasibility. In feasible cases, it furnishes a match that is optimal for X-uniformity among matches with Z-dispersion as stipulated. To illustrate, we describe the algorithm's use in a study comparing womens' to mens' working conditions; and we compare our method to a commonly used alternative, greedy matching, which is neither optimal nor as flexible but is algorithmically much simpler. The comparison finds meaningful advantages, in terms of both bias and efficiency, for our more studied approach.

In this study, the cytokine-producing profile of progenitor T cells (pro-T cells) was determined. During screening of a complementary DNA library generated from activated mouse pro-T cells, a cytokine designated lymphotactin was discovered. Lymphotactin is similar to members of both the Cys-Cys and Cys-X-Cys chemokine families but lacks two of the four cysteine residues that are characteristic of the chemokines. Lymphotactin is also expressed in activated CD8+ T cells and CD4-CD8- T cell receptor alpha beta + thymocytes. It has chemotactic activity for lymphocytes but not for monocytes or neutrophils. The gene encoding lymphotactin maps to chromosome one. Taken together, these observations suggest that lymphotactin represents a novel addition to the chemokine superfamily.

BACKGROUND: Invasive aspergillosis (IA) is an important cause of morbidity and mortality among immunocompromised patients. Echinocandins are novel antifungal molecules with in vitro and in vivo activity against Aspergillus species. METHODS: We investigated the efficacy and safety of caspofungin in the treatment of IA. Ninety patients with IA who were refractory to or intolerant of amphotericin B, lipid formulations of amphotericin B, or triazoles were enrolled to receive caspofungin. RESULTS: Efficacy was assessed for 83 patients who had infection consistent with definitions of IA and who received >or=1 dose of study drug. Common underlying conditions included hematologic malignancy (48% of patients), allogeneic blood and marrow transplantation (25% of patients), and solid-organ transplantation (11% of patients). Seventy-one patients (86%) were refractory to and 12 patients (14%) were intolerant of previous therapy. A favorable response to caspofungin therapy was observed in 37 (45%) of 83 patients, including 32 (50%) of 64 with pulmonary aspergillosis and 3 (23%) of 13 with disseminated aspergillosis. Two patients discontinued caspofungin therapy because of drug-related adverse events. Drug-related nephrotoxicity and hepatotoxicity occurred infrequently. CONCLUSION: Caspofungin demonstrated usefulness in the salvage treatment of IA.

Dendritic cells (DCs) are professional antigen-presenting cells that have the ability to sense infection and tissue stress, sample and present antigen to T lymphocytes, and induce different forms of immunity and tolerance. The functional versatility of DCs depends on their remarkable ability to translate collectively the information from both the invading microbes and their resident tissue microenvironments and then make an appropriate immune response. Recent progress in understanding TLR biology has illuminated the mechanisms by which DCs link innate and adaptive antimicrobial immune responses. However, how tissue microenvironments shape the function of DCs has remained elusive. Recent studies of TSLP (thymic stromal lymphopoietin), an epithelial cell-derived cytokine that strongly activates DCs, provide evidence at a molecular level that epithelial cells/tissue microenvironments directly communicate with DCs. We review recent progress on how TSLP expressed within thymus and peripheral lymphoid and nonlymphoid tissues regulates DC-mediated central tolerance, peripheral T cell homeostasis, and inflammatory Th2 responses.