Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 26
Filter
Add more filters











Publication year range
1.
Atmos Environ (1994) ; 234: 117543-11753, 2020 Aug 01.
Article in English | MEDLINE | ID: mdl-32601520

ABSTRACT

A photochemical model platform for Hawaii, Puerto Rico, and Virgin Islands predicting O3, PM2.5, and regional haze would be useful to support assessments relevant for the National Ambient Air Quality Standards (NAAQS), Regional Haze Rule, and the Prevention of Significant Deterioration (PSD) program. These areas have not traditionally been modeled with photochemical transport models, but a reasonable representation of meteorology, emissions (natural and anthropogenic), chemistry, and deposition could support air quality management decisions in these areas. Here, a prognostic meteorological model (Weather Research and Forecasting) and photochemical transport (Community Multiscale Air Quality) model were applied for the entire year of 2016 at 27, 9, and 3 km grid resolution for areas covering the Hawaiian Islands and Puerto Rico/Virgin Islands. Model predictions were compared against surface and upper air meteorological and chemical measurements available in both areas. The vertical gradient of temperature, humidity, and winds in the troposphere was well represented. Surface layer meteorological model performance was spatially variable, but temperature tended to be underestimated in Hawaii. Chemically speciated daily average PM2.5 was generally well characterized by the modeling system at urban and rural monitors in Hawaii and Puerto Rico/Virgin Islands. Model performance was notably impacted by the wildfire emission methodology. Model performance was mixed for hourly SO2, NO2, PM2.5, and CO and was often related to how well local emissions sources were characterized. SO2 predictions were much lower than measurements at monitors near active volcanos on Hawaii, which was expected since volcanic emissions were not included in these model simulations. Further research is needed to assess emission inventory representation of these areas and how microscale meteorology influenced by the complex land-water and terrain interfaces impacts higher time resolution performance.

2.
Sci Total Environ ; 659: 1555-1566, 2019 Apr 01.
Article in English | MEDLINE | ID: mdl-31096365

ABSTRACT

Prescribed grassland fires in the Flint Hills region of central Kansas and northern Oklahoma are a common tool for land management. Local to regional scale impacts on air quality from grassland fires in this region are not well understood, which is important as these types of prescribed fires may increase in the future to preserve broader areas of native grasses in the central U.S. Routine air quality and deposition measurements from sites in and near the Flint Hills were examined for coincident increases during periods of increased prescribed grassland fires. Prescribed fire activity in this region was quantified using satellite detections and multiple publicly available data products of area burned information. March and April comprise over half (41 to 93%) of all annual fire detections in the Flint Hills region seen from satellites between 2007 and 2018 excluding drought years. Annual total fire detections in this region range between 1 and 12 thousand and account for approximately 3% of all fire detections in the contiguous U.S. Annual acres burned ranged from 0.2 to 2 million acres based on U.S. EPA's National Emission Inventory, which accounts for 4 to 38% of grasslands in the area. A comparison of weekly standardized anomalies suggests a relationship between periods of increased grassland fire activity and elevated levels of PM2.5 organic carbon, elemental carbon, and potassium. Daily 1-hr maximum ozone (O3), ammonia (NH3), sulfur dioxide (SO2), and oxidized nitrogen gases measured at Konza Prairie also had increased levels when prescribed grassland fire activity was highest. This detailed characterization of prescribed fire activity in the Flint Hills and associated air quality impacts will benefit future efforts to understand changes in atmospheric composition due to changing land management practices.

3.
Sci Total Environ ; 637-638: 1137-1149, 2018 Oct 01.
Article in English | MEDLINE | ID: mdl-29801207

ABSTRACT

The Rim Fire was one of the largest wildfires in California history, burning over 250,000 acres during August and September 2013 affecting air quality locally and regionally in the western U.S. Routine surface monitors, remotely sensed data, and aircraft based measurements were used to assess how well the Community Multiscale Air Quality (CMAQ) photochemical grid model applied at 4 and 12 km resolution represented regional plume transport and chemical evolution during this extreme wildland fire episode. Impacts were generally similar at both grid resolutions although notable differences were seen in some secondary pollutants (e.g., formaldehyde and peroxyacyl nitrate) near the Rim fire. The modeling system does well at capturing near-fire to regional scale smoke plume transport compared to remotely sensed aerosol optical depth (AOD) and aircraft transect measurements. Plume rise for the Rim fire was well characterized as the modeled plume top was consistent with remotely sensed data and the altitude of aircraft measurements, which were typically made at the top edge of the plume. Aircraft-based lidar suggests O3 downwind in the Rim fire plume was vertically stratified and tended to be higher at the plume top, while CMAQ estimated a more uniformly mixed column of O3. Predicted wildfire ozone (O3) was overestimated both at the plume top and at nearby rural and urban surface monitors. Photolysis rates were well characterized by the model compared with aircraft measurements meaning aerosol attenuation was reasonably estimated and unlikely contributing to O3 overestimates at the top of the plume. Organic carbon was underestimated close to the Rim fire compared to aircraft data, but was consistent with nearby surface measurements. Periods of elevated surface PM2.5 at rural monitors near the Rim fire were not usually coincident with elevated O3.


Subject(s)
Air Pollutants/analysis , Environmental Monitoring , Models, Chemical , Wildfires , Air Pollution/statistics & numerical data , Aircraft , California , Models, Theoretical , Ozone , Satellite Imagery
4.
Atmos Environ (1994) ; 166: 22-33, 2017.
Article in English | MEDLINE | ID: mdl-32612448

ABSTRACT

Prescribed burns of winter wheat stubble and Kentucky bluegrass fields in northern Idaho and eastern Washington states (U.S.A.) were sampled using ground-, aerostat-, airplane-, and laboratory-based measurement platforms to determine emission factors, compare methods, and provide a current and comprehensive set of emissions data for air quality models, climate models, and emission inventories. Batch measurements of PM2.5, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated dibenzodioxins/dibenzofurans (PCDDs/PCDFs), and continuous measurements of black carbon (BC), particle mass by size, CO, CO2, CH4, and aerosol characteristics were taken at ground level, on an aerostat-lofted instrument package, and from an airplane. Biomass samples gathered from the field were burned in a laboratory combustion facility for comparison with these ground and aerial field measurements. Emission factors for PM2.5, organic carbon (OC), CH4, and CO measured in the field study platforms were typically higher than those measured in the laboratory combustion facility. Field data for Kentucky bluegrass suggest that biomass residue loading is directly proportional to the PM2.5 emission factor; no such relationship was found with the limited wheat data. CO2 and BC emissions were higher in laboratory burn tests than in the field, reflecting greater carbon oxidation and flaming combustion conditions. These distinctions between field and laboratory results can be explained by measurements of the modified combustion efficiency (MCE). Higher MCEs were recorded in the laboratory burns than from the airplane platform. These MCE/emission factor trends are supported by 1-2 min grab samples from the ground and aerostat platforms. Emission factors measured here are similar to other studies measuring comparable fuels, pollutants, and combustion conditions. The size distribution of refractory BC (rBC) was single modal with a log-normal shape, which was consistent among fuel types when normalized by total rBC mass. The field and laboratory measurements of the Angstrom exponent (α) and single scattering albedo (ω) exhibit a strong decreasing trend with increasing MCEs in the range of 0.9-0.99. Field measurements of α and ω were consistently higher than laboratory burns, which is likely due to less complete combustion. When VOC emissions are compared with MCE, the results are consistent for both fuel types: emission factors increase as MCE decreases.

5.
Zoo Biol ; 35(3): 222-7, 2016 May.
Article in English | MEDLINE | ID: mdl-27142724

ABSTRACT

Research suggests that zoo visitors can have positive, negative, and neutral impacts on captive primate welfare; however, research investigating the implications of visitor-animal feeding experiences is extremely limited. In the UK, a large proportion of BIAZA zoos that house lemur species offer visitor interaction experiences (16 out of 33). This study investigated the impact on the behavior of a family group of crowned lemurs (Eulemur coronatus) housed at Newquay Zoo, UK of visitors, accompanied by a keeper, entering the enclosure to feed the lemurs. Behavior was observed under four conditions: (i) during visitor feed; (ii) 30 min post-visitor feed; (iii) during a keeper feed; and (iv) 30 min post-keeper feed. Keeper feeds were conducted by keepers only, on the day after visitor feeds. The lemur group spent significantly less time performing aggressive behavior and was also significantly more interactive with keepers during visitor feeds compared with keeper-only feeds. There was no significant difference in behaviors performed immediately after interacting with visitors. Over the study period, there was a tendency for interactions with visitors to increase, and for interactions with keepers during visitor feeds to decrease. After a 28-day interval without visitor interaction, the lemurs' interaction with visitors had returned to the level recorded at the start of the study. In conclusion, visitor interaction did not compromise the welfare of the study subjects in either the short- or long-term, while an increase in visitor interactions over time has interesting implications for the enrichment properties of, or habituation to, unfamiliar humans. Zoo Biol. 35:222-227, 2016. © 2016 Wiley Periodicals, Inc.


Subject(s)
Animal Welfare , Animals, Zoo/physiology , Behavior, Animal , Feeding Methods/veterinary , Lemur/physiology , Aggression , Animals , Animals, Zoo/psychology , Feeding Methods/psychology , Female , Humans , Lemur/psychology , Male , United Kingdom
6.
Osteoarthritis Cartilage ; 20(5): 382-387, 2012 May.
Article in English | MEDLINE | ID: mdl-22353693

ABSTRACT

In osteoarthritis (OA) the synovium is often inflamed and inflammatory cytokines contribute to cartilage damage. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have anti-inflammatory effects whereas omega-6 polyunsaturated fatty acids (n-6 PUFAs) have, on balance, proinflammatory effects. The goal of our study was to assess the association of fasting plasma phospholipid n-6 and n-3 PUFAs with synovitis as measured by synovial thickening on contrast enhanced (CE) knee MRI and cartilage damage among subjects in the Multicenter Osteoarthritis Study (MOST). MOST is a cohort study of individuals who have or are at high risk of knee OA. An unselected subset of participants who volunteered obtained CE 1.5T MRI of one knee. Synovitis was scored in six compartments and a summary score was created. This subset also had fasting plasma, analyzed by gas chromatography for phospholipid fatty acid content, and non-CE MRI, read for cartilage morphology according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS) method. The association between synovitis and cartilage morphology and plasma PUFAs was assessed using logistic regression after controlling for the effects of age, sex, and BMI. 472 out of 535 subjects with CE MRI had complete data on synovitis, cartilage morphology and plasma phospholipids. Mean age was 60 years, mean BMI 30, and 50% were women. We found an inverse relation between total n-3 PUFAs and the specific n-3, docosahexaenoic acid with patellofemoral cartilage loss, but not tibiofemoral cartilage loss or synovitis. A positive association was observed between the n-6 PUFA, arachidonic acid, and synovitis. In conclusion, systemic levels of n-3 and n-6 PUFAs which are influenced by diet, may be related to selected structural findings in knees with or at risk of OA. Future studies manipulating the systemic levels of these fatty acids may be warranted to determine the effects on structural damage in knee OA.


Subject(s)
Fatty Acids, Omega-3/blood , Fatty Acids, Omega-6/blood , Osteoarthritis, Knee/blood , Synovitis/blood , Aged , Biomarkers/blood , Cartilage, Articular/pathology , Cohort Studies , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Osteoarthritis, Knee/complications , Osteoarthritis, Knee/pathology , Synovitis/etiology , Synovitis/pathology
7.
Health Phys ; 98 Suppl 1: S6-11, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20065668

ABSTRACT

A "proof of concept" was conducted to determine the effectiveness of a survey method for cost-effective recovery of depleted uranium (DU) fragments from contaminated soil piles at Sandia National Laboratories. First, DU fragments ranging from less than a gram up to 48 g were covered by various thicknesses of soil and used for detector efficiency measurements. The efficiencies were measured for three different sodium iodide detectors: a 5.1-cm by 5.1-cm (2-inch by 2-inch) detector, a 7.6-cm by 7.6-cm (3-inch by 3-inch) detector, and a Field Instrument for the Detection of Low Energy Radiation (FIDLER) detector. The FIDLER detector was found to be superior to the other detectors in each measurement. Next, multiple 7.6-cm (3-inch) layers of soil, taken from the contaminated piles, were applied to a clean pad of soil. Each layer was scanned by an array of eight FIDLER detectors pulled by a tractor. The array, moving 10.2 to 12.7 cm s(-1) (4 to 5 inches per second), automatically recorded radiation count data along with associated detector coordinates at 3-s intervals. The DU fragments were located and identified with a handheld system consisting of a FIDLER detector and a positioning system and then removed. After DU removal, the affected areas were re-scanned and a new lift of contaminated soil was applied. The detection capability of the system as a function of DU fragment mass and burial depth was modeled and determined to be sufficient to ensure that the dose-based site concentration goals would be met. Finally, confirmation soil samples were taken from random locations and from decontaminated soil areas. All samples had concentrations of U that met the goal of 400-500 pCi g(-1).


Subject(s)
Decontamination/methods , Soil Pollutants, Radioactive/isolation & purification , Uranium/isolation & purification , Cost-Benefit Analysis , Decontamination/economics , New Mexico , Radiometry/instrumentation
8.
Blood Coagul Fibrinolysis ; 13(1): 7-17, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11994562

ABSTRACT

Transmittance waveforms are the optical data generated during clot formation on photo-optical coagulation analyzers and are used to define specific events of the clotting reactions. Thus, a prothrombin time (PT) or an activated partial thromboplastin time (aPTT) can be divided into a pre-coagulation phase, a coagulation phase, and a post-coagulation phase. These phases are further characterized by parameters that define the timing, the rate, the 'slope', and the magnitude of the signal change of the reactions. We investigated the transmittance waveform parameters obtained during PT and aPTT of patients with antiphospholipid antibodies (APLA) who were or were not taking warfarin, normal donors, and non-APLA patients taking warfarin. An abnormal deflection in the pre-coagulation phase of the PT (called slope 1) was observed in 61.5% of the patients with APLA, in contrast to 5.9% of non-APLA patients taking warfarin (P= 0.0015). The presence of an abnormal PT slope 1 was reagent specific and was inversely correlated with the anticardiolipin antibody immunoglobulin G (IgG) level, which suggests that the abnormal PT slope 1 may reflect interactions between patient IgG and components from the thromboplastin, possibly phospholipids. The abnormal PT slope 1 values may be of diagnostic utility in the identification of patients with antiphospholipid syndromes.


Subject(s)
Antibodies, Antiphospholipid/blood , Blood Coagulation Tests/methods , Antibodies, Anticardiolipin/blood , Anticoagulants/administration & dosage , Anticoagulants/pharmacology , Antiphospholipid Syndrome/blood , Antiphospholipid Syndrome/diagnosis , Antiphospholipid Syndrome/drug therapy , Blood Coagulation Tests/instrumentation , Blood Coagulation Tests/standards , Case-Control Studies , Humans , Indicators and Reagents , Kinetics , Warfarin/administration & dosage , Warfarin/pharmacology
9.
J Rheumatol ; 28(7): 1655-65, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11469475

ABSTRACT

OBJECTIVE: To test the effects of a high intensity home-based progressive strength training program on the clinical signs and symptoms of osteoarthritis (OA) of the knee. METHODS: Forty-six community dwelling patients, aged 55 years or older with knee pain and radiographic evidence of knee OA, were randomized to a 4 month home based progressive strength training program or a nutrition education program (attention control). Thirty-eight patients completed the trial with an adherence of 84% to the intervention and 65% to the attention control. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index pain and physical function subscales. Secondary outcomes included clinical knee examination, muscle strength, physical performance measures, and questionnaires to measure quality of life variables. RESULTS: Patients in the strength training group who completed the trial had a 71% improvement in knee extension strength in the leg reported as most painful versus a 3% improvement in the control group (p < 0.01). In a modified intent to treat analysis, self-reported pain improved by 36% and physical function by 38% in the strength training group versus 11 and 21%, respectively, in the control group (p = 0.01 for between group comparison). In addition, those patients in the strength training group who completed the trial had a 43% mean reduction in pain (p = 0.01 vs controls), a 44% mean improvement in self-reported physical function (p < 0.01 vs controls), and improvements in physical performance, quality of life, and self-efficacy when compared to the control group. CONCLUSION: High intensity, home based strength training can produce substantial improvements in strength, pain, physical function and quality of life in patients with knee OA.


Subject(s)
Exercise Therapy , Osteoarthritis, Knee/therapy , Aged , Female , Home Care Services , Humans , Male , Middle Aged , Nutrition Assessment , Osteoarthritis, Knee/psychology , Pain Measurement , Quality of Life , Recovery of Function
11.
J Am Pharm Assoc (Wash) ; 40(5 Suppl 1): S56-7, 2000.
Article in English | MEDLINE | ID: mdl-11029871

ABSTRACT

Industry trends, such as the growth of managed care and pharmacist-led cognitive services, have led to greater reliance on pharmacy technicians. In a recent USP study of medication errors, the dispensing function was the function in which technician errors were most likely to occur. Pharmacists and technicians must work as a team to reduce medication errors and improve quality assurance. Medication errors provide an opportunity to identify system problems, generate solutions, and implement corrective measures.


Subject(s)
Liability, Legal , Medication Errors/prevention & control , Pharmacists/legislation & jurisprudence , Pharmacy/trends , Technology, Pharmaceutical , United States
12.
Curr Opin Pediatr ; 12(1): 23-8, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10676770

ABSTRACT

Large and unusually large von Willebrand factor (vWf) multimers may be responsible for systemic platelet aggregation in thrombotic thrombocytopenic purpura (TTP). This possibility is supported by studies that show deficient vWf-cleaving metalloproteinase and increased platelet-vWf binding during TTP episodes. In acute idiopathic TTP, decreased vWf metalloproteinase is the result of autoantibodies against the enzyme. In familial and acquired hemolytic-uremic syndrome, vWf-cleaving metalloproteinase activity is normal. A deficiency or defect in factor H, which normally dampens the activation of C3 via the alternative complement pathway, has been seen in some patients with familial hemolytic-uremic syndrome. Ticlopidine therapy is an important risk factor for TTP.


Subject(s)
Hemolytic-Uremic Syndrome , Purpura, Thrombotic Thrombocytopenic , Anti-Bacterial Agents/therapeutic use , Child , Diagnosis, Differential , Erythropoietin/deficiency , Hemolytic-Uremic Syndrome/diagnosis , Hemolytic-Uremic Syndrome/etiology , Hemolytic-Uremic Syndrome/therapy , Humans , Plasma Exchange , Purpura, Thrombotic Thrombocytopenic/diagnosis , Purpura, Thrombotic Thrombocytopenic/physiopathology , Purpura, Thrombotic Thrombocytopenic/therapy , Survival Analysis , Ticlopidine/adverse effects
13.
Am J Hematol ; 63(1): 46-53, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10602169

ABSTRACT

We report the case of a man with chronic myelocytic leukemia (CML) and a 46,XY,t(5;9;22) karyotype who developed acute myelocytic leukemia (AML) with a 45,X,t(8;21) karyotype 11 years after bone marrow transplantation (BMT) from his HLA-matched sister. Fluorescent in situ hybridization (FISH) studies and molecular analysis using short tandem repeat (STR) sequences proved the new leukemia to be of donor cell origin. Donor cell leukemia (DCL) after BMT is rare. Our review of the literature found 15 cases following BMT for leukemia and 2 cases after BMT for benign hematological disorders. In fewer than half the reported cases were molecular studies available to confirm the cytogenetic evidence for DCL, and the longest previously reported interval between BMT and DCL was 6 years.


Subject(s)
Bone Marrow Transplantation/adverse effects , Leukemia, Myeloid, Acute/etiology , Tissue Donors , Adult , Chromosomes, Human, Pair 21 , Chromosomes, Human, Pair 8 , Female , Genotype , Humans , In Situ Hybridization, Fluorescence , Karyotyping , Leukemia, Myeloid, Acute/genetics , Male , Tandem Repeat Sequences , Time Factors , Translocation, Genetic
14.
Can J Appl Physiol ; 21(2): 149-54, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8727477

ABSTRACT

Seven competitive road cyclists (M +/- SE = 23.7 +/- 1.5 yr, 70.5 +/- 1.7 kg) participated to determine the effects of cycling body position on physiological responses during uphill cycling and maximal oxygen uptake (VO2max). There was no significant difference in VO2max between seated and standing positions on a cycle ergometer (66.4 +/- 1.6 vs. 66.4 +/- 1.7 ml . kg-1 . min-1). When the subjects rode their own bicycle on a treadmill, oxygen uptake and heart rate were significantly (p < 0.05) higher during standing when subjects bicycled at 20.0 km . h-1 (4% grade), but no difference was observed when riding at 12.3 km . h-1 (10% grade). Leg RPE was significantly (p < 0.05) lower for standing position up a 10% grade. The results suggest that the standing position is less economical during moderate hill climbing, but during steep hill climbing, it results in a decreased sensation of effort in the legs.


Subject(s)
Bicycling/physiology , Oxygen Consumption , Physical Exertion/physiology , Posture , Adult , Ergometry/instrumentation , Exercise Test/instrumentation , Heart Rate , Humans , Lactates/blood , Leg/physiology , Male , Pulmonary Gas Exchange , Sensation
16.
Postgrad Med ; 94(5): 34, 1993 Oct.
Article in English | MEDLINE | ID: mdl-8415334
17.
Can J Surg ; 35(2): 188-91, 1992 Apr.
Article in English | MEDLINE | ID: mdl-1562931

ABSTRACT

Surgery for urinary incontinence is often not considered in elderly persons (older than 65 years) because of their age. In this paper the authors examine the effect of age on the success rate and complications of abdominal correction (modified retropubic colpourethropexy with or without other major gynecologic surgery) for genuine stress incontinence. Other than age, length of hospital stay and some urodynamic values there were no statistically significant differences in success and complication rates between the elderly and younger patients. The authors conclude that in properly selected elderly patients with genuine stress incontinence, retropubic colpourethropexy is as safe and effective as in younger patients.


Subject(s)
Urinary Incontinence, Stress/surgery , Adult , Age Factors , Aged , Aged, 80 and over , Female , Humans , Length of Stay , Middle Aged , Postoperative Complications , Risk Factors , Urinary Incontinence, Stress/physiopathology , Urodynamics
19.
Am J Obstet Gynecol ; 165(3): 679-81, 1991 Sep.
Article in English | MEDLINE | ID: mdl-1892197

ABSTRACT

One hundred twenty-four women with chronic, persistent lower urinary tract symptoms who had been scheduled for elective urodynamic investigations at Mount Sinai's Urodynamic Investigative Unit were divided into two blind, randomized groups, receiving either a placebo or prophylactic antibiotic. At the time of urodynamic testing, the rate of unsuspected urinary tract infection was 8.1%. There was no statistically significant decrease in postinstrumentation infection rate in the group who received prophylactic antibiotics. We conclude that, given in the fashion described in the study, prophylactic antibiotics are not effective in preventing urinary tract infections caused by urodynamic testing.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacteriuria/prevention & control , Adult , Aged , Female , Humans , Middle Aged , Prospective Studies , Urodynamics
20.
Mol Cell Endocrinol ; 79(1-3): 1-12, 1991 Aug.
Article in English | MEDLINE | ID: mdl-1936536

ABSTRACT

Sertoli cell conditioned medium (SCCM) contains a potent mitogen, Sertoli cell secreted growth factor (SCSGF). A431 cells, derived from a human epidermoid carcinoma have provided an excellent model cell line for the study of this apparently unique activity secreted by rat Sertoli cells in vitro. Previously, it was shown that SCCM contained an epidermal growth factor (EGF)-like activity which was thought to be the mitogen for A431 cells. The present study showed that these two factors are distinct entities. The secretion of the EGF-like activity decreased with increasing number of culture days, while that of SCSGF and of another Sertoli cell specific protein, transferrin remained constant. The addition of SCCM stimulated whereas 2.5 ng/ml EGF inhibited the A431 cell growth. The proliferative response of A431 cells to a wide variety of growth factors and known Sertoli cell secretions was investigated. SCSGF was the only growth factor of known Sertoli cell secretions tested (transforming growth factors (TGF alpha, TGF beta), EGF, bombesin, fibroblast growth factor (FGF), platelet derived growth factor (PDGF), insulin-like growth factors 1 and 2 (IGF-1 and IGF-2), prostaglandins E-1 and E-2, insulin, transferrin and lactate) which stimulated A431 cell proliferation. SCSGF was mitogenic for A431 cells even in the presence of serum in the culture medium. The partially purified SCSGF was heat- and acid-stable, protease-sensitive with a molecular weight of 14,000. It did not bind to heparin or concanavalin A-Sepharose. The secretion of a mitogenic activity by the Sertoli cell which is different from other previously identified growth factors and which coincides with active spermatogenesis could have important implications in the regulation of spermatogenesis.


Subject(s)
Growth Substances/isolation & purification , Sertoli Cells/metabolism , Animals , Carcinoma, Squamous Cell , Cell Division/drug effects , Cell Line , Cells, Cultured , Chromatography, Affinity , Chromatography, High Pressure Liquid , Epidermal Growth Factor/pharmacology , ErbB Receptors/metabolism , Humans , Kinetics , Male , Rats , Rats, Inbred Strains , Transforming Growth Factor beta/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL