Texas Southern University
UniversityHouston, Texas, United States
Research output, citation impact, and the most-cited recent papers from Texas Southern University (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Texas Southern University
BACKGROUND: Defective cellular transport processes can lead to aberrant accumulation of trace elements, iron, small molecules and hormones in the cell, which in turn may promote the formation of reactive oxygen species, promoting DNA damage and aberrant expression of key regulatory cancer genes. As DNA damage and uncontrolled proliferation are hallmarks of cancer, including epithelial ovarian cancer (EOC), we hypothesized that inherited variation in the cellular transport genes contributes to EOC risk. METHODS: In total, DNA samples were obtained from 14,525 case subjects with invasive EOC and from 23,447 controls from 43 sites in the Ovarian Cancer Association Consortium (OCAC). Two hundred seventy nine SNPs, representing 131 genes, were genotyped using an Illumina Infinium iSelect BeadChip as part of the Collaborative Oncological Gene-environment Study (COGS). SNP analyses were conducted using unconditional logistic regression under a log-additive model, and the FDR q<0.2 was applied to adjust for multiple comparisons. RESULTS: The most significant evidence of an association for all invasive cancers combined and for the serous subtype was observed for SNP rs17216603 in the iron transporter gene HEPH (invasive: OR = 0.85, P = 0.00026; serous: OR = 0.81, P = 0.00020); this SNP was also associated with the borderline/low malignant potential (LMP) tumors (P = 0.021). Other genes significantly associated with EOC histological subtypes (p<0.05) included the UGT1A (endometrioid), SLC25A45 (mucinous), SLC39A11 (low malignant potential), and SERPINA7 (clear cell carcinoma). In addition, 1785 SNPs in six genes (HEPH, MGST1, SERPINA, SLC25A45, SLC39A11 and UGT1A) were imputed from the 1000 Genomes Project and examined for association with INV EOC in white-European subjects. The most significant imputed SNP was rs117729793 in SLC39A11 (per allele, OR = 2.55, 95% CI = 1.5-4.35, p = 5.66x10-4). CONCLUSION: These results, generated on a large cohort of women, revealed associations between inherited cellular transport gene variants and risk of EOC histologic subtypes.
This article discusses the effects of ideological control in conventional entrepreneurial discourses and praxis. Following postmodernist, deconstructionist and critical theory traditions, the ideas expressed about the phenomenon of entrepreneurship, and its contiguous notions and concepts, are deconstructed to reveal the dysfunctional effects of ideological control both in research and in praxis. It is shown that the concept of entrepreneurship is discriminatory, gender‐biased, ethnocentrically determined and ideologically controlled, sustaining not only prevailing societal biases, but serving as a tapestry for un‐ examined and contradictory assumptions and knowledge about the reality of entrepreneurs.
We synthesized and evaluated a novel class of chelator-free [(64)Cu]CuS nanoparticles (NPs) suitable both for PET imaging and as photothermal coupling agents for photothermal ablation. These [(64)Cu]CuS NPs are simple to make, possess excellent stability, and allow robust noninvasive micro-PET imaging. Furthermore, the CuS NPs display strong absorption in the near-infrared (NIR) region (peak at 930 nm); passive targeting prefers the tumor site, and mediated ablation of U87 tumor cells occurs upon exposure to NIR light both in vitro and in vivo after either intratumoral or intravenous injection. The combination of small diameter (∼11 nm), strong NIR absorption, and integration of (64)Cu as a structural component makes these [(64)Cu]CuS NPs ideally suited for multifunctional molecular imaging and therapy.
Carbon nanotubes are now becoming an important material for use in day to day life because of their unique physical properties. The toxicological impact of these materials has not yet been studied in detail, thereby limiting their use. In the present study, the toxicity of single-walled carbon nanotubes (SWCNT) was assessed in human keratinocyte cells. The results show increased oxidative stress and inhibition of cell proliferation in response to treatment of keratinocytes with SWCNT particles. In addition, the signaling mechanism in keratinocytes upon exposure to SWCNT particles was investigated. Results from the study suggest that SWCNT particles activate NF-kappaB in a dose-dependent manner in human keratinocytes. Further, the mechanism of activation of NF-kappaB was due to the activation of stress-related kinases by SWCNT particles in keratinocytes. In conclusion, these studies show the mechanism of toxicity induced by SWCNT particles.
At nanoscale, man-made materials may show unique properties that differ from bulk and dissolved counterparts. The unique properties of engineered nanomaterials not only impart critical advantages but also confer toxicity because of their unwanted interactions with different biological compartments and cellular processes. In this review, we discuss various entry routes of nanomaterials in the human body, their applications in daily life, and the mechanisms underlying their toxicity. We further explore the passage of nanomaterials into air, water, and soil ecosystems, resulting in diverse environmental impacts. Briefly, we probe the available strategies for risk assessment and risk management to assist in reducing the occupational risks of potentially hazardous engineered nanomaterials including the control banding (CB) approach. Moreover, we substantiate the need for uniform guidelines for systematic analysis of nanomaterial toxicity, in silico toxicological investigations, and obligation to ensure the safe disposal of nanowaste to reduce or eliminate untoward environmental and health impacts. At the end, we scrutinize global regulatory trends, hurdles, and efforts to develop better regulatory sciences in the field of nanomedicines.
This paper presents data on the siting of solid waste facilities in one of the nation's fastest growing cities, Houston, Texas. The findings reveal that solid waste sites were not randomly scattered over the Houston landscape but were likely to be found in predominantly black neighborhoods and near black schools. Institutionalized discrimination in the housing market, lack of zoning, and decisions by public officials over the past fifty years are major factors that have contributed to Houston's black neighborhoods becoming the “dumping ground” for the area's solid waste.
Workforce diversity refers to the composition of work units in terms of the cultural or demographic characteristics that are salient and symbolically meaningful in the relationships among group members. Although generally thought of as the purview of management research, the topic of workforce diversity draws from and is relevant to research from sociology and psychology. In this review, we highlight two issues: (a) the importance of the substantial research on inequality to an adequate understanding of workforce diversity and (b) the need to link discussions of workforce diversity to the structural relationships among groups within the society. We organize the review in terms of three dimensions of the relationships among groups: power, status, and numbers (or composition). We highlight research from sociology, psychology, and management and show similarities and gaps across these fields. We also briefly discuss the outcomes of workforce diversity in the workplace.
The electron-phonon interaction and related transport properties are investigated in monolayer silicene and MoS${}_{2}$ by using a density functional theory calculation combined with a full-band Monte Carlo analysis. In the case of silicene, the results illustrate that the out-of-plane acoustic phonon mode may play the dominant role unlike its close relative, graphene. The small energy of this phonon mode, originating from the weak $sp$${}^{2}$ $\ensuremath{\pi}$ bonding between Si atoms, contributes to the high scattering rate and significant degradation in electron transport. In MoS${}_{2}$, the longitudinal acoustic phonons show the strongest interaction with electrons. The key factor in this material appears to be the $Q$ valleys located between the $\ensuremath{\Gamma}$ and $K$ points in the first Brillouin zone as they introduce additional intervalley scattering. The analysis also reveals the potential impact of extrinsic screening by other carriers and/or adjacent materials. Finally, the effective deformation potential constants are extracted for all relevant intrinsic electron-phonon scattering processes in both materials.
Pancreatic ductal adenocarcinoma (PDAC) remains a lethal malignancy with an immunosuppressive microenvironment that is resistant to most therapies. IL17 is involved in pancreatic tumorigenesis, but its role in invasive PDAC is undetermined. We hypothesized that IL17 triggers and sustains PDAC immunosuppression. We inhibited IL17/IL17RA signaling using pharmacological and genetic strategies alongside mass cytometry and multiplex immunofluorescence techniques. We uncovered that IL17 recruits neutrophils, triggers neutrophil extracellular traps (NETs), and excludes cytotoxic CD8 T cells from tumors. Additionally, IL17 blockade increases immune checkpoint blockade (PD-1, CTLA4) sensitivity. Inhibition of neutrophils or Padi4-dependent NETosis phenocopies IL17 neutralization. NMR spectroscopy revealed changes in tumor lactate as a potential early biomarker for IL17/PD-1 combination efficacy. Higher expression of IL17 and PADI4 in human PDAC corresponds with poorer prognosis, and the serum of patients with PDAC has higher potential for NETosis. Clinical studies with IL17 and checkpoint blockade represent a novel combinatorial therapy with potential efficacy for this lethal disease.
It is critical to develop highly effective antimicrobial agents that are not harmful to humans and do not present adverse effects on the environment. Although antimicrobial studies of graphene-based nanomaterials are still quite limited, some researchers have paid particular attention to such nanocomposites as promising candidates for the next generation of antimicrobial agents. The polyvinyl-N-carbazole (PVK)-graphene oxide (GO) nanocomposite (PVK-GO), which contains only 3 wt% of GO well-dispersed in a 97 wt% PVK matrix, presents excellent antibacterial properties without significant cytotoxicity to mammalian cells. The high polymer content in this nanocomposite makes future large-scale material manufacturing possible in a high-yield process of adiabatic bulk polymerization. In this study, the toxicity of PVK-GO was assessed with planktonic microbial cells, biofilms, and NIH 3T3 fibroblast cells. The antibacterial effects were evaluated against two Gram-negative bacteria: Escherichia coli and Cupriavidus metallidurans; and two Gram-positive bacteria: Bacillus subtilis and Rhodococcus opacus. The results show that the PVK-GO nanocomposite presents higher antimicrobial effects than the pristine GO. The effectiveness of the PVK-GO in solution was demonstrated as the nanocomposite "encapsulated" the bacterial cells, which led to reduced microbial metabolic activity and cell death. The fact that the PVK-GO did not present significant cytotoxicity to fibroblast cells offers a great opportunity for potential applications in important biomedical and industrial fields.
Translation of nanoparticles (NPs) into clinical practice has been limited by toxic effects induced by nonspecific accumulation of NPs in healthy organs after systemic administration. The ideal NPs should accumulate in the target site, carry out their function, and then ultimately be eliminated from the body. Here, we show a single-compartment, multifunctional ultrasmall copper sulfide nanodot (CuS ND) that is rapidly cleared from the body. These CuS NDs have a hydrodynamic diameter of <6 nm, can efficiently absorb near-infrared light for photothermal ablation therapy, and stably incorporate the copper-64 radioisotope for noninvasive positron emission tomography (PET). Importantly, ∼95% of CuS NDs are excreted intact through the renal-urinary system within 24 h with minimal retention in the liver and the spleen. The ultrasmall CuS NDs accumulate in 4T1 tumors in Balb/c mice, as monitored by PET imaging, and mediate tumor ablation when combined with near-infrared light irradiation. As a first example of PET-visible, renal-clearable inorganic nanomaterials with peak absorption in the near-infrared region, CuS NDs represent a robust platform for cancer imaging and therapy.
BACKGROUND: Rodentia is the most diverse order of placental mammals, with extant rodent species representing about half of all placental diversity. In spite of many morphological and molecular studies, the family-level relationships among rodents and the location of the rodent root are still debated. Although various datasets have already been analyzed to solve rodent phylogeny at the family level, these are difficult to combine because they involve different taxa and genes. RESULTS: We present here the largest protein-coding dataset used to study rodent relationships. It comprises six nuclear genes, 41 rodent species, and eight outgroups. Our phylogenetic reconstructions strongly support the division of Rodentia into three clades: (1) a "squirrel-related clade", (2) a "mouse-related clade", and (3) Ctenohystrica. Almost all evolutionary relationships within these clades are also highly supported. The primary remaining uncertainty is the position of the root. The application of various models and techniques aimed to remove non-phylogenetic signal was unable to solve the basal rodent trifurcation. CONCLUSION: Sequencing and analyzing a large sequence dataset enabled us to resolve most of the evolutionary relationships among Rodentia. Our findings suggest that the uncertainty regarding the position of the rodent root reflects the rapid rodent radiation that occurred in the Paleocene rather than the presence of conflicting phylogenetic and non-phylogenetic signals in the dataset.
Cancer is a hyperproliferative disorder that involves transformation, dysregulation of apoptosis, proliferation, invasion, angiogenesis and metastasis. Extensive research during the last 30 years has revealed much about the biology of cancer. Drugs used to treat most cancers are those that can block cell signalling, including growth factor signalling (e.g., epidermal growth factor); prostaglandin production (e.g., COX-2); inflammation (e.g., inflammatory cytokines: NF-kappaB, TNF, IL-1, IL-6, chemokines); drug resistance gene products (e.g., multi-drug resistance); cell cycle proteins (e.g., cyclin D1 and cyclin E); angiogenesis (e.g., vascular endothelial growth factor); invasion (e.g., matrix metalloproteinases); antiapoptosis (e.g., bcl-2, bcl-X(L), XIAP, survivin, FLIP); and cellular proliferation (e.g., c-myc, AP-1, growth factors). Numerous reports have suggested that Ayurvedic plants and their components mediate their effects by modulating several of these recently identified therapeutic targets. However, Ayurvedic medicine requires rediscovery in light of our current knowledge of allopathic (modern) medicine. The focus of this review is to elucidate the Ayurvedic concept of cancer, including its classification, causes, pathogenesis and prevention; surgical removal of tumours; herbal remedies; dietary modifications; and spiritual treatments.
This study, involving 139 employees from a variety of industries, organizations, and positions in Singapore, measured the effects of mood on the intentions of employees to contribute actions that are organizationally desirable but are not part of their formal job requirements (organizational citizenship behavior). After effects of established patterns of historical organizational citizenship behavior, demographic characteristics, and employee positive and negative affectivity had been controlled, stepwise regression analysis revealed that the amount of positive affect currently experienced by an employee significantly influenced the employee's intention to perform specific acts of organizational citizenship.
Curcumin derived from the tropical plant Curcuma longa has a long history of use as a dietary agent, food preservative, and in traditional Asian medicine. It has been used for centuries to treat biliary disorders, anorexia, cough, diabetic wounds, hepatic disorders, rheumatism, and sinusitis. The preventive and therapeutic properties of curcumin are associated with its antioxidant, anti-inflammatory, and anticancer properties. Extensive research over several decades has attempted to identify the molecular mechanisms of curcumin action. Curcumin modulates numerous molecular targets by altering their gene expression, signaling pathways, or through direct interaction. Curcumin regulates the expression of inflammatory cytokines (e.g., TNF, IL-1), growth factors (e.g., VEGF, EGF, FGF), growth factor receptors (e.g., EGFR, HER-2, AR), enzymes (e.g., COX-2, LOX, MMP9, MAPK, mTOR, Akt), adhesion molecules (e.g., ELAM-1, ICAM-1, VCAM-1), apoptosis related proteins (e.g., Bcl-2, caspases, DR, Fas), and cell cycle proteins (e.g., cyclin D1). Curcumin modulates the activity of several transcription factors (e.g., NF-κB, AP-1, STAT) and their signaling pathways. Based on its ability to affect multiple targets, curcumin has the potential for the prevention and treatment of various diseases including cancers, arthritis, allergies, atherosclerosis, aging, neurodegenerative disease, hepatic disorders, obesity, diabetes, psoriasis, and autoimmune diseases. This review summarizes the molecular mechanisms of modulation of gene expression by curcumin.
BACKGROUND: Orthostatic hypotension (OH) is defined as a reduction of systolic blood pressure of at least 20 mmHg, or diastolic blood pressure of at least 10 mmHg from a sitting to a standing position. It is a common physical finding among older adults and associated with significant morbidity and mortality. Use of medications that have the potential to induce OH, particularly concomitant use of several of such medications, is a major factor for the development of OH. OBJECTIVES: To describe the prevalence of symptomatic and asymptomatic OH in veterans aged 75 years and older attending a geriatric clinic, and to assess the association between OH and the number of potentially causative medications used. METHODS: Charts of all patients who attended a VA geriatric clinic (Michael E. DeBakey VA Medical Center) during the period of 1 June 2002 to 1 June 2003 were reviewed retrospectively for (i) the use of potentially causative medications, i.e. medications that were reported to cause OH in at least 1% of the general population and that were available in the VA formulary, (ii) the presence or absence of OH, and (iii) the presence or absence of symptomatic OH. Patients with primary autonomic dysfunction, Parkinson's disease, and patients who were unable to stand, or who had no assessment for both sitting and standing blood pressure for other reasons were excluded. RESULTS: A total of 505 individual patients attended the clinic during the study period, and 342 patients fit the inclusion criteria. About 189 of these patients (55%) had OH. Among patients with OH, 61 patients (33%) were symptomatic, including 52 patients who had falls. The prevalence of OH in patients receiving zero, one, two, and three or more potentially causative medications was 35, 58, 60 and 65% respectively. Receiving hydrochlorothiazide was associated with the highest prevalence of OH (65%), followed by receiving lisinopril (60%), trazodone (58%), furosemide (56%) and terazosin (54%). CONCLUSION: The prevalence of OH is very high in older veterans and significantly related to the number of concurrent causative medications used. Providers should be educated to reduce the amount of potentially causative medications in the elderly and better assess patients in which use of such medications is necessary to avoid symptomatic OH.
Urban road dust can be highly enriched with trace metals such as copper, lead, zinc, and platinum group elements (PGEs) that are released primarily from vehicles. Concentrations of these metals are up to about 100 times higher than background levels. Lead concentrations in sediment core have declined dramatically due to phase out of leaded gasoline. Recent ban on the use of lead wheel balancing weight in Europe and in some US states will accelerate the decline of lead in the environment. Concentrations of copper, zinc, and PGEs in sediments in many urban areas have increased continuously due to increase of urban sprawl and increased numbers and travel distance of vehicle. Wear of brake pads and tyres are the primary sources of copper and zinc in urban road dust. PGEs have been released from catalytic converters since the mid-1970s. Contaminated urban road dust is picked up by stormwater runoff and delivered into local receiving waterbodies (e.g. streams, rivers, lakes, and estuaries). Concentrations of these metals in waterbodies and sediments receiving stormwater runoff from densely populated urban areas are high enough to impair the health of aquatic organisms and frequently exceed water quality criteria and sediment quality guidelines. In order to improve the quality of urban waterbodies, legal regulations are necessary to reduce release of toxic metals from vehicle use as demonstrated in the case of lead in gasoline. Recent regulations and agreement to reduce copper content in brake pads to 0.5% by 2026 in the USA should result in significant reduction of copper entering urban watersheds. A less optimal option is removal of suspended sediments from stormwater runoff before they enter receiving waterbodies using best management practices such as retention ponds, detention basins, and grass swales.
Essential oils of the fruits of three organically grown cultivars of Egyptian fennel (Foeniculum vulgare var. azoricum, Foeniculum vulgare var. dulce and Foeniculum vulgare var. vulgare) were examined for their chemical constituents, antimicrobial and antioxidant activities. Gas chromatography/mass spectrometry analysis of the essential oils revealed the presence of 18 major monoterpenoids in all three cultivars but their percentage in each oil were greatly different. trans-Anethole, estragole, fenchone and limonene were highly abundant in all of the examined oils. Antioxidant activities of the essential oils were evaluated using the DPPH radical scavenging, lipid peroxidation and metal chelating assays. Essential oils from the azoricum and dulce cultivars were more effective antioxidants than that from the vulgare cultivar. Antimicrobial activities of each oil were measured against two species of fungi, two species of Gram negative and two species of Gram positive bacteria. All three cultivars showed similar antimicrobial activity.
Observations of solar wind proton temperatures indicate that the solar wind is heated as it moves outward toward the orbit of Earth. This heating, which may be the result of electron heat conduction and perhaps MHD waves, has proven difficult to quantify and hence is often neglected in MHD models of the solar wind. An alternate approach to finding explicit heating terms for the MHD energy equation is to use a polytropic approximation. This paper discusses the properties of the polytropic approximation and its application to the solar wind plasma. By using data from the Helios 1 spacecraft, an empirical value for the polytropic index of the free‐streaming solar wind is determined. Various corrections to the data are made to account for velocity gradients, nonuniformity in radial sampling, and stream interaction regions. The polytropic index, as derived from proton data, is found to be independent of speed state, within statistical error, and has an average value of 1.46. If magnetic pressure is included, the polytropic index has an average value of 1.58.
BACKGROUND: The rarity of mutations in PALB2, CHEK2 and ATM make it difficult to estimate precisely associated cancer risks. Population-based family studies have provided evidence that at least some of these mutations are associated with breast cancer risk as high as those associated with rare BRCA2 mutations. We aimed to estimate the relative risks associated with specific rare variants in PALB2, CHEK2 and ATM via a multicentre case-control study. METHODS: We genotyped 10 rare mutations using the custom iCOGS array: PALB2 c.1592delT, c.2816T>G and c.3113G>A, CHEK2 c.349A>G, c.538C>T, c.715G>A, c.1036C>T, c.1312G>T, and c.1343T>G and ATM c.7271T>G. We assessed associations with breast cancer risk (42 671 cases and 42 164 controls), as well as prostate (22 301 cases and 22 320 controls) and ovarian (14 542 cases and 23 491 controls) cancer risk, for each variant. RESULTS: ) and ATM c.7271T>G OR 11.0 (95% CI 1.42 to 85.7, p=0.0012). We also found evidence of association with breast cancer risk for three variants in CHEK2, c.349A>G OR 2.26 (95% CI 1.29 to 3.95), c.1036C>T OR 5.06 (95% CI 1.09 to 23.5) and c.538C>T OR 1.33 (95% CI 1.05 to 1.67) (p≤0.017). Evidence for prostate cancer risk was observed for CHEK2 c.1343T>G OR 3.03 (95% CI 1.53 to 6.03, p=0.0006) for African men and CHEK2 c.1312G>T OR 2.21 (95% CI 1.06 to 4.63, p=0.030) for European men. No evidence of association with ovarian cancer was found for any of these variants. CONCLUSIONS: This report adds to accumulating evidence that at least some variants in these genes are associated with an increased risk of breast cancer that is clinically important.