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At least 541 records · Page 30Linked to original sources
PubMed2005

Cell-autonomous induction of functional tumor suppressor 15-lipoxygenase 2 (15-LOX2) contributes to replicative senescence of human prostate progenitor cells.

Normal human prostatic (NHP) epithelial cells undergo senescence in vitro and in vivo, but little is known about the tissue-specific molecular mechanisms. Here we first characterize young primary NHP cells as CK5(+)/CK18(+) intermediate basal cells that also express several other putative stem/progenitor cell markers including p63, CD44, alpha2beta1, and hTERT. When cultured in serum- and androgen-free medium, NHP cells gradually lose the expression of these markers, slow down in proliferation, and enter senescence. Several pieces of evidence implicate 15-lipoxygenase 2 (15-LOX2), a molecule with a restricted tissue expression and most abundantly expressed in adult human prostate, in the replicative senescence of NHP cells. First, the 15-LOX2 promoter activity and the mRNA and protein levels of 15-LOX2 and its multiple splice variants are upregulated in serially passaged NHP cells, which precede replicative senescence and occur in a cell-autonomous manner. Second, all immortalized prostate epithelial cells and prostate cancer cells do not express 15-LOX2. Third, PCa cells stably transfected with 15-LOX2 or 15-LOX2sv-b, a splice variant that does not possess arachidonate-metabolizing activity, show a passage-related senescence-like phenotype. Fourth, infection of early-passage NHP cells with retroviral vectors encoding 15-LOX2 or 15-LOX2sv-b induces partial cell-cycle arrest and big and flat senescence-like phenotype. Finally, 15-LOX2 protein expression in human prostate correlates with age. Together, these data suggest that 15-LOX2 may represent an endogenous prostate senescence gene and its tumor-suppressing functions might be associated with its ability to induce cell senescence.

Adolescent↗
PubMed2003

Isolation, expression pattern of a novel human RAB gene RAB41 and characterization of its intronless homolog RAB41P.

Small GTPases form a big family including Ras, Rho, Rac, Rab, Sar1/Arf subfamilies and Ran homologs, playing important roles in diverse cellular processes. Through data mining, a novel human RAB41 gene was predicted and subsequently isolated from human testis. The open reading frame of RAB41 is 636bp in length. RAB41 was composed of three exons, and it was mapped to chromosome 3q21.3 by comparing with the human genomic data. RAB41 protein contains a RAB domain. Similarity analysis indicated that RAB41 is closely similar to RAB19. The results of PCR amplification indicated that human RAB41 is widely expressed in brain, testis, lung, heart, ovary, colon, kidney, uterus and spleen but not in liver. By genomic searching, an intronless pseudogene homologous to RAB41 at chromosome 16--RAB41P was identified at human chromosome 16q11.2. Flanking the pseudogene RAB41P in human genome, there exist some transposable elements LINEs--L1, whose contribution in the generation of this intronless homolog is discussed.

Amino Acid Sequence↗
PubMed2002

Building supertrees: an empirical assessment using the grass family (Poaceae).

Large and comprehensive phylogenetic trees are desirable for studying macroevolutionary processes and for classification purposes. Such trees can be obtained in two different ways. Either the widest possible range of taxa can be sampled and used in a phylogenetic analysis to produce a "big tree," or preexisting topologies can be used to create a supertree. Although large multigene analyses are often favored, combinable data are not always available, and supertrees offer a suitable solution. The most commonly used method of supertree reconstruction, matrix representation with parsimony (MRP), is presented here. We used a combined data set for the Poaceae to (1) assess the differences between an approach that uses combined data and one that uses different MRP modifications based on the character partitions and (2) investigate the advantages and disadvantages of these modifications. Baum and Ragan and Purvis modifications gave similar results. Incorporating bootstrap support associated with pre-existing topologies improved Baum and Ragan modification and its similarity with a combined analysis. Finally, we used the supertree reconstruction approach on 55 published phylogenies to build one of most comprehensive phylogenetic trees published for the grass family including 403 taxa and discuss its strengths and weaknesses in relation to other published hypotheses.

Data Interpretation, Statistical↗
PubMed2001

Pulmonary antioxidant enzyme activity during early development: Effect of ventilation.

OBJECTIVE: To examine the effect of tidal liquid ventilation (TLV) and conventional gas ventilation (GV) on the pulmonary antioxidant enzyme (AOE) activity in two groups of preterm lambs at 110 and 120 days of gestation and to compare these results to age-matched fetal controls. DESIGN: Experimental, prospective, randomized, controlled study. SETTING: School of medicine, department of physiology. SUBJECTS: Thirty-two premature lambs at 110 days (n = 16) and 120 days (n = 16) gestation. INTERVENTIONS: Six lambs at 110 and 120 days were ventilated with TLV for 4 hrs. Three lambs at 110 days were ventilated with GV for 3 hrs, and six lambs at 120 days were ventilated with GV for 4 hrs. Four lambs, each at 110 and 120 days, were used as age-matched fetal controls. Measurements: Sequential measurements of arterial blood chemistries were performed in all groups. Biochemical assays included catalase activity, superoxide dismutase activity, and glutathione peroxidase activity. Histologic examinations of lung sections from TLV and GV lungs were performed. Main Result: Despite vast differences in physiologic outcome, there were fewer differences in AOE activity as a function of ventilation (fetal control, GV, and TLV lambs) and/or gestational age. There were no significant differences in superoxide dismutase and glutathione peroxidase activity as a function of age or ventilation. Catalase activity was significantly higher (p <.05) in fetal 120-day control lambs (24.8 +/- 1.9 units/mg protein) relative to the 110-day control lambs (14.3 +/- 1.7 units/mg protein). Catalase activity significantly (p <.05) decreased in both GV and TLV 120 day lambs compared with fetal controls; yet, in the 110-day gestational lambs, there were no significant differences in enzyme level as a function of ventilation. Thus, an age-specific response to ventilation was evident for catalase activity. CONCLUSION: The present data demonstrate several developmental differences in AOE activity. The lack of ventilation effect in AOE activity, in view of the big difference in physiologic and inflammatory outcomes, suggests that mechanisms associated with free radicals do not underlie the response to different modes of ventilation.

Journal Article↗
PubMed2005

Diversity and change in suicide seasonality over 125 years.

BACKGROUND: Recent research has corroborated the notion that seasonality in suicide is more heterogeneous and less consistent than postulated by former scholars. This work investigates the smoothing out of suicide seasonality in Switzerland between the late 19th and the end of the 20th century. It includes analyses by region and by suicide method. METHODS: Monthly suicide frequencies in Switzerland are available for the period 1876-2000. Data on canton/region are available for the periods 1901-1920 and 1969-2000, and data on suicide method for the periods 1881-1920 and 1969-2000. Analyses focusing on the overall change rely on data aggregated by quinquennia. The Edwards' test and the peak-low ratio were used in univariate analyses of seasonality. Putative determinants of the peak-low ratio were examined using regression analysis with cantonal data. RESULTS: The decrease of seasonal effects in suicide applies to a period of more than 100 years in Switzerland. Big differences of seasonal effects have existed all the time with regard to specific methods and to specific regions. No seasonality was apparent in poisoning, and in Geneva and Basle City, respectively. However, the seasonal effects have been most impressive in drowning and hanging suicides, and in rural Catholic regions. In regression analysis, the decline in suicide seasonality is associated with the decline in the agricultural work force. CONCLUSIONS: The smoothing out of suicide seasonality in Switzerland has been a continuous long term process, which probably started by the end of 19th century. Seasonal effects in suicide will probably fade away in most regions of Switzerland and in most suicide methods. This process is in parallel with the disappearance of the traditional rural society.

Female↗
PubMed1994

Colliding forces in radiology: technologic imperative, resource limitations, and accountability demands.

Advances in radiology over the past 20 years are the product of a technologic imperative that has produced new approaches to the acquisition of medical images and modifications to conventional approaches. The imperative has placed radiology at the leading edge of the computer-technology era of modern medicine and has also produced several big-ticket technologies that have been identified as major contributors to rising health care costs. Consequently, the demands for quantitative data on the impact and cost-effectiveness of the use of these technologies in the clinical arena are increasing. Meeting the growing demand for accountability in radiology requires that the discipline adopt innovative approaches for assessing its technologies and acquire new types of data, including documentation of cost savings accrued by selective use of radiologic technologies and demonstration of the efficiency and cost-effectiveness of triage schemes that lead to more effective decision making. The requirement of quantitative accountability represents a new way of doing business for radiology and a new approach to management for those responsible for business.

Cost-Benefit Analysis↗
PubMed2006

Use of statistical techniques to synthesize explicit criteria developed by an expert panel.

OBJECTIVES: Methodology based on expert panels has been commonly used to evaluate the appropriateness of interventions. An important issue is the adequate synthesis of the generated information in an applicable way to clinical decision making. This paper shows how statistical procedures help synthesize the results of an expert panel. METHODS: Three statistical techniques were applied to an expert panel that developed explicit criteria to assess the appropriateness of total hip joint replacement: classification tree, regression tree and multiple correspondence analysis combined with automatic classification. RESULTS: Results provided by the three models were shown in graphical displays and were compared to the original panel results using crude and weighted probability of misclassification. Results were also applied to real interventions in order to know the implication of the misclassification on real patients. CONCLUSIONS: The statistical techniques help summarize data from panels of experts and provide useful decision models for clinical practice, especially when the number of indications is big. However, degree of misclassification and its implication should be taken into account.

Algorithms↗
PubMed2005

Reconciliation and interpretation of the Big Bend National Park light extinction source apportionment: results from the Big Bend Regional Aerosol and Visibility Observational Study--part II.

The recently completed Big Bend Regional Aerosol and Visibility Observational (BRAVO) Study focused on particulate sulfate source attribution for a 4-month period from July through October 1999. A companion paper in this issue by Schichtel et al. describes the methods evaluation and results reconciliation of the BRAVO Study sulfate attribution approaches. This paper summarizes the BRAVO Study extinction budget assessment and interprets the attribution results in the context of annual and multiyear causes of haze by drawing on long-term aerosol monitoring data and regional transport climatology, as well as results from other investigations. Particulate sulfates, organic carbon, and coarse mass are responsible for most of the haze at Big Bend National Park, whereas fine particles composed of light-absorbing carbon, fine soils, and nitrates are relatively minor contributors. Spring and late summer through fall are the two periods of high-haze levels at Big Bend. Particulate sulfate and carbonaceous compounds contribute in a similar magnitude to the spring haze period, whereas sulfates are the primary cause of haze during the late summer and fall period. Atmospheric transport patterns to Big Bend vary throughout the year, resulting in a seasonal cycle of different upwind source regions contributing to its haze levels. Important sources and source regions for haze at Big Bend include biomass smoke from Mexico and Central America in the spring and African dust during the summer. Sources of sulfur dioxide (SO2) emissions in Mexico, Texas, and in the Eastern United States all contribute to Big Bend haze in varying amounts over different times of the year, with a higher contribution from Mexican sources in the spring and early summer, and a higher contribution from U.S. sources during late summer and fall. Some multiple-day haze episodes result from the influence of several source regions, whereas others are primarily because of emissions from a single source region.

Air↗
PubMed1989

[Installation of electronic data processing at the Vienna Forensic Medicine Institute--experiences and outlook].

1985 the systematic use of personal computers in the Viennese institute of forensic medicine began. Due to the big engineering progress there was no more need to connect to a computer center. A gradual installation and a strict determination of requirements are important for computer systems, whereas a personal computer might be useful for word processing only as well.

Austria↗
PubMed1996

[Somatization mental disorders based on data on the dispensary care of the employees of a large industrial enterprise].

Psychosomatic borderline disorders were observed in 366 individuals during prophylactic medical examination of 675 employers of big oil-chemical enterprise. The main group consisted of 189 cases of psychosomatic disturbances. They included the very borderline disorders (neuroses, psychogenic depressions, psychopathies) as well as cyclothymias and schizothymic personal deviations too. The majority of disorders were presented by depressive and asthenic syndromes cases. The direct correlation was found between the frequencies of such disturbances rise and the duration of industrial work in conditions of professional hazards. The role of social and cultural factors in psychosomatic disorders development was also established.

Chemical Industry↗
PubMed2005

Estimation of the additional costs of chemotherapy for patients with advanced non-small cell lung cancer.

BACKGROUND: A large multicentre randomised trial, the Big Lung Trial, which in part compared supportive care with or without cisplatin-based chemotherapy in patients with advanced non-small cell lung cancer, provided an opportunity to evaluate the impact on the UK National Health Service of the costs incurred with the use of chemotherapy. METHODS: This costing study was based on the retrospective collection of resource use data from hospital records. Case notes from 194 patients (98 chemotherapy + supportive care (C), 96 supportive care alone (NoC)) were inspected in eight centres recruiting the largest numbers of patients into the Big Lung Trial. Quantities were multiplied by fixed unit costs to calculate a total cost for each patient. The main outcome measure was the total cost incurred by the use of secondary care resources (including investigations, chemotherapy, radiotherapy, surgical procedures, inpatient days, outpatient attendances, and hospice inpatient care) in the two groups. RESULTS: Patients randomised to receive cisplatin-based chemotherapy had an average of 3.4 more inpatient bed days than the mean of 11.9 days for patients randomised to supportive care alone, and more outpatient attendances. NoC patients were more likely to have received palliative radiotherapy. The mean total cost for C patients was 5355 sterling pound compared with 3595 sterling pound for the NoC group, difference 760 sterling pound (95% CI 781 sterling pound to 2742 sterling pound ). When split, the cost in the C group associated with the administration of chemotherapy was 1233 sterling pound and non-chemotherapy costs were 4122 sterling pound . CONCLUSION: The additional cost of chemotherapy was not offset by a reduction in subsequent costs (as the non-chemotherapy costs were similar), so the survival benefit of about 10 weeks observed in the C group was achieved with the cost of chemotherapy administration.

Adult↗
PubMed1998

Regulation of endothelin-1 in human non-pigmented ciliary epithelial cells by tumor necrosis factor-alpha.

Endothelins (ET) are potent vasoactive peptides present in many ocular structures and are formed from precursor Big endothelins (Big ET-1) by the action of an endothelin-converting enzyme (ECE). ET-1 is thought to decrease intraocular pressure by contracting the ciliary muscle thus enhancing the outflow of aqueous humor through the Canal of Schlemm and trabecular meshwork. However, the mechanisms involved in the regulation of endothelin-1 (ET-1) synthesis and release in ocular tissues have not been fully characterized. In this study we examined the effect of tumor necrosis factor-alpha(TNF-alpha; 10 nm), a proinflammatory cytokine, on the cellular mechanisms leading to ET-1 synthesis and release in SV-40 transformed human ciliary non-pigmented epithelial cells (HNPE). ET-1 and Big endothelin-1 (Big ET-1) immunoreactivity was time-dependently increased following TNF-alphatreatment. Phorbol esters (PMA), activators of PKC, also raised the immunoreactive levels of ET-1 and Big ET-1 while, staurosporine, a PKC inhibitor (20 nm), decreased ET-1 levels in TNF-alpha-stimulated cells. Pre-treatment with phosphoramidon (1 micron) an ECE-inhibitor, followed by TNF-alpha stimulation, decreased ir-ET-1 levels. Cycloheximide (9 micron), a protein synthesis inhibitor, decreased TNF-alpha-stimulated levels for ir-ET-1 and ir-Big ET-1, suggesting that TNF-alpha may be directly regulating ET-1 expression at the ET-1 gene. Our data indicates that TNF-alpha regulates ET-1 levels in HNPE cells possibly by activating PKC either to stimulate protein synthesis and/or to enhance ET-1 secretion. These results suggest that ET-1 released from the ciliary body may play an important role in aqueous humor dynamics following cytokine activation.

Cells, Cultured↗
PubMed2006

Quantitative trait analysis and geographic variability of natural populations of Zaprionus indianus, a recent invader in Brazil.

Five natural samples of a recent South America invader, the drosophilid Zaprionus indianus, were investigated with the isofemale line technique. These samples were compared to five African mainland populations, investigated with the same method. The results were also compared to data obtained on mass cultures of other populations from Africa and India. Three quantitative traits were measured on both sexes, wing and thorax length and sternopleural bristle number. We did not find any latitudinal trend among the American samples, while a significant increase in body size with latitude was observed in the Indian and, to a lesser degree, in the African populations. American populations were also characterized by their bigger size. Genetic variability, estimated by the intraclass correlation among isofemale lines, was similar in American and African populations. The intraline, nongenetic variability was significantly less in the American samples, suggesting a better developmental stability, the origin of which is unclear. A positive relationship was evident between intraline variability of size traits and the wing-thorax length correlation. Altogether, our data suggest that the colonizing propagule introduced to Brazil had a fairly large size, preventing any bottleneck effect being detected. The big body size of American flies suggests that they came from a high-latitude African country. The lack of a latitudinal dine in America seems to be related to the short time elapsed since introduction. The very rapid spread of Z. indianus all over South America suggests that it might rapidly invade North America.

Animals↗
PubMed1985

Effect of antibody-mediated crosslinking of insulin on its bioactivity and receptor binding.

Precipitating anti-insulin antibodies or anti-insulin IgG/anti-IgG complexes bind insulin in a highly aggregated form and thus should preferably be capable of inducing receptor aggregation, which has recently been suggested to be a precondition for insulin bioactivity. We, therefore, studied the influence of antibody-mediated crosslinking of insulin on the glucose conversion into CO2 in rat fat cells and glycogen synthesis in rat liver cells. As far as possible receptor-bound insulin was measured in parallel. Insulin bound to antibodies with low insulin precipitating capacity had no or little bioactivity and receptor reactivity on fat cells. The bioactivity, however, could be restored in part by addition of a second antibody. On liver cells, second antibody-mediated crosslinking of insulin-antibody complexes resulted in an enhancement of receptor reactivity, and insulin bioactivity of such crosslinked immune complexes was demonstrable. An insulin-precipitating antiserum was shown to form insulin-antibody complexes with significant bioactivity in fat cells which correlated with their receptor binding. In each case antibodies had no or little effect in the absence of insulin. Our data suggest that insulin neutralization by antibodies can be compensated by crosslinking the insulin-antibody complexes or by formation of big complexes precipitating by themselves. This is probably due to the induction of receptor aggregation.

Adipose Tissue↗
PubMed2003

Ochratoxin A in raisins and currants: basic extraction procedure used in two small marketing surveys of the occurrence and control of the heterogeneity of the toxins in samples.

A basic extraction procedure for analysis of ochratoxin A (OTA) in currants and raisins is described, as well as the occurrence of OTA and a control of heterogeneity of the toxin in samples bought for two small marketing surveys 1999/2000 and 2001/02. Most samples in the surveys were divided into two subsamples that were individually prepared as slurries and analysed separately. The limit of quantification for the method was estimated as 0.1 microg kg(-1) and recoveries of 85, 90 and 115% were achieved in recovery experiments at 10, 5 and 0.1 microg kg(-1), respectively. Of all 118 subsamples analysed in the surveys, 96 (84%) contained ochratoxin A at levels above the quantification level and five samples (4%) contained more than the European Community legislation of 10 microg kg(-1). The OTA concentrations found in the first survey were in the range < 0.1-19.0 microg kg(-1) with a median concentration of 0.9 microg kg(-1). In the 2001/02 study, the range was < 0.1-34.6 microg kg(-1) with a median of 0.2 microg kg(-1). Big differences were often achieved between individual subsamples of the original sample, which indicate a wide heterogeneous distribution of the toxin. Data from the repeatability test as well as recovery experiments from the same slurries showed that preparation of slurries as described here seemed to give a homogeneous and representative sample. The extraction with the basic sodium bicarbonate-methanol mixture used in the surveys gave similar or somewhat higher OTA values on some samples tested in a comparison with a weak phosphoric acid water-methanol extraction mixture.

Carcinogens↗
PubMed2002

Heterogeneity and seroprevalence of a newly identified avian hepatitis e virus from chickens in the United States.

We recently identified and characterized a novel virus, designated avian hepatitis E virus (avian HEV), from chickens with hepatitis-splenomegaly syndrome (HS syndrome) in the United States. Avian HEV is genetically related to but distinct from human and swine HEVs. To determine the extent of genetic variation and the seroprevalence of avian HEV infection in chicken flocks, we genetically identified and characterized 11 additional avian HEV isolates from chickens with HS syndrome and assessed the prevalence of avian HEV antibodies from a total of 1,276 chickens of different ages and breeds from 76 different flocks in five states (California, Colorado, Connecticut, Virginia, and Wisconsin). An enzyme-linked immunosorbent assay using a truncated recombinant avian HEV ORF2 antigen was developed and used to determine avian HEV seroprevalence. About 71% of chicken flocks and 30% of chickens tested in the study were positive for antibodies to avian HEV. About 17% of chickens younger than 18 weeks were seropositive, whereas about 36% of adult chickens were seropositive. By using a reverse transcription-PCR (RT-PCR) assay, we tested 21 bile samples from chickens with HS syndrome in California, Connecticut, New York, and Wisconsin for the presence of avian HEV RNA. Of the 21 bile samples, 12 were positive for 30- to 35-nm HEV-like virus particles by electron microscopy (EM). A total of 11 of the 12 EM-positive bile samples and 6 of the 9 EM-negative bile samples were positive for avian HEV RNA by RT-PCR. The sequences of a 372-bp region within the helicase gene of 11 avian HEV isolates were determined. Sequence analyses revealed that the 11 field isolates of avian HEV had 78 to 100% nucleotide sequence identities to each other, 79 to 88% identities to the prototype avian HEV, 76 to 80% identities to chicken big liver and spleen disease virus, and 56 to 61% identities to other known strains of human and swine HEV. The data from this study indicated that, like swine and human HEVs, avian HEV isolates are genetically heterogenic and that avian HEV infection is enzoonotic in chicken flocks in the United States.

Animals↗
PubMed1993

Localization of endothelin-1-like immunoreactivity in human placenta.

We examined the distribution of endothelin-1-like immunoreactivity in human placenta, using the immunoperoxidase technique. A specific polyclonal antibody to endothelin-1 was raised in rabbits, which recognized endothelin-1 and its precursor molecule, big endothelin. Immunoperoxidase staining revealed that endothelin-1-like immunoreactivity was widely distributed in the placenta. Endothelin-1-like immunoreactivity was present in endothelial cells of capillaries of the microvilli and in small- and medium-sized arteries and veins. The distribution of endothelin-1-like immunoreactivity was similar to the distribution of Factor VIII-related antigen, which stains endothelial cells. The nature of endothelin in the human placenta was further examined with cultured umbilical vein endothelial cells. Endothelial cells released endothelin-like material into the culture medium. The amount of endothelin-like material varied directly with time of incubation and the amount of fetal calf serum in the culture medium. Fractionation of the endothelin-1-like material by reversed-phase high-performance liquid chromatography (HPLC) and quantitation by radioimmunoassay (RIA) revealed that endothelin-like immunoreactivity co-eluted with endothelin-1 but not with big endothelin-1. We conclude that endothelin-1-like immunoreactivity is widely distributed in vascular endothelium of the human placenta. These data are compatible with a role for endothelin as an autocrine or paracrine modulator of vascular tone in the human placenta.

Capillaries↗