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At least 1,099 records · Page 61Linked to original sources

PubMed1997

Condom availability in New York City public high schools: relationships to condom use and sexual behavior.

OBJECTIVES: This study examines the impact of the condom availability program in New York City public high schools by comparing rates of sexual activity and condom use for New York students and similar students in Chicago. METHODS: A total of 7119 students from 12 randomly selected New York schools and 5738 students from 10 Chicago schools participated in a cross-sectional survey. RESULTS: New York students, compared with Chicago students, reported equal rates of sexual activity but higher rates of condom use at last intercourse (odds ratio [OR] = 1.36). For higher-risk students (those with three or more sexual partners in the past 6 months), condom use was greater in New York (OR = 1.85) than in Chicago. CONCLUSIONS: Condom availability has a modest but significant effect on condom use and does not increase rates of sexual activity. These findings suggest that school-based condom availability can lower the risk of HIV and other sexually transmitted diseases for urban teenagers in the United States.

Adolescent↗

PubMed1999

The impact of condom availability [correction of distribution] in Seattle schools on sexual behavior and condom use.

OBJECTIVES: Ten Seattle high schools made condoms available through vending machines, baskets in school clinics, or both. This study measured the number of condoms that students obtained and subsequent changes in sexual behavior and condom use. METHODS: Schoolwide surveys were administered in spring 1993 and in spring 1995, before and during the condom availability program. These data were compared with data from nationally representative surveys administered at the same time. RESULTS: Seattle students obtained an average of 4.6 condoms per year, the vast majority from baskets and very few from vending machines. Relative to the national samples, the percentage of Seattle students who had ever had sex remained stable after the program began; current sexual activity decreased significantly; and the percentage of sexually experienced students who used a condom the last time they had sex decreased significantly, particularly in the 5 schools with baskets of condoms in clinics. CONCLUSIONS: Making condoms available in Seattle schools enabled students to obtain relatively large numbers of condoms but did not lead to increases in either sexual activity or condom use.

Adolescent↗

PubMed1999

Premature mortality in the United States: the roles of geographic area, socioeconomic status, household type, and availability of medical care.

OBJECTIVES: This study examined premature mortality by county in the United States and assessed its association with metro/urban/rural geographic location, socioeconomic status, household type, and availability of medical care. METHODS: Age-adjusted years of potential life lost before 75 years of age were calculated and mapped by county. Predictors of premature mortality were determined by multiple regression analysis. RESULTS: Premature mortality was greatest in rural counties in the Southeast and Southwest. In a model predicting 55% of variation across counties, community structure factors explained more than availability of medical care. The proportions of female-headed households and Black populations were the strongest predictors, followed by variables measuring low education, American Indian population, and chronic unemployment. Greater availability of generalist physicians predicted fewer years of life lost in metropolitan counties but more in rural counties. CONCLUSIONS: Community structure factors statistically explain much of the variation in premature mortality. The degree to which premature mortality is predicted by percentage of female-headed households is important for policy-making and delivery of medical care. The relationships described argue strongly for broadening the biomedical model.

Aged↗

PubMed2004

Osteoinductivity of commercially available demineralized bone matrix. Preparations in a spine fusion model.

BACKGROUND: Although autogenous bone is the most widely used graft material for spinal fusion, demineralized bone matrix preparations are available as alternatives or supplements to autograft. They are prepared by acid extraction of most of the mineralized component, with retention of the collagen and noncollagenous proteins, including growth factors. Differences in allograft processing methods among suppliers might yield products with different osteoinductive activities. The purpose of this study was to compare the efficacy of three different commercially available demineralized bone matrix products for inducing spinal fusion in an athymic rat model. METHODS: Sixty male athymic rats underwent spinal fusion and were divided into three groups of eighteen animals each. Group I received Grafton Putty; Group II, DBX Putty; and Group III, AlloMatrix Injectable Putty. A control group of six animals (Group IV) underwent decortication alone. Six animals from each of the three experimental groups were killed at each of three intervals (two, four, and eight weeks), and the six animals from the control group were killed at eight weeks. At each of the time-points, radiographic and histologic analysis and manual testing of the explanted spines were performed. RESULTS: The spines in Group I demonstrated higher rates of radiographically evident fusion at eight weeks than did the spines in Group III or Group IV (p < 0.05). Manual testing of the spines at four weeks revealed variable fusion rates (five of six in Group I, two of six in Group II, and none of six in Group III). At eight weeks, all six spines in Group I, three of the six in Group II, and no spine in Group III or IV had fused. Histologic analysis of the spines in Groups I, II, and III demonstrated varying amounts of residual demineralized bone matrix and new bone formation. Group-I spines demonstrated the most new bone formation. CONCLUSIONS: This study demonstrated differences in the osteoinductive potentials of commercially available demineralized bone matrices in this animal model.

Animals↗

PubMedDate not supplied

Sequential supercritical fluid extraction (SSFE) for estimating the availability of high molecular weight polycyclic aromatic hydrocarbons in historically polluted soils.

Sequential supercritical fluid (CO2) extraction (SSFE) was applied to eight historically contaminated soils from diverse sources with the aim to elucidate the sorption-desorption behavior of high molecular weight polycyclic aromatic hydrocarbons (PAHs). The method involved five extraction phases applying successively harsher conditions by increasing fluid temperature and density mobilizing target compounds from different soil particle sites. Two groups of soils were identified based on readily desorbing (available) PAH fractions obtained under mildest extraction conditions (e.g., readily desorbing fractions of fluoranthene and pyrene significantly varied between the soils ranging from <10 to >90%). Moreover, extraction behavior strongly correlated with molecular weight revealing decreasing available PAH fractions with increasing weight. Physicochemical soil parameters such as particle size distribution and organic dry mass were found to have no distinct effect on the sorption-desorption behavior of PAHs in the different soils. However, PAH profiles significantly correlated with readily available pollutant fractions; soils with relatively less mobile PAHs had higher proportions of five- and six-ring PAHs and vice versa. Eventually, biodegradability corresponded well with PAH recoveries under the two mildest extraction phases. However, a quantitative relationship was only established for soils with biodegradable PAHs. Out of eight soils, five showed no biodegradation including the four soils with the lowest fraction of readily desorbing PAHs. Only one soil (which was found to be highly toxic to Vibrio fischeri) did not match the overall pattern showing no PAH biodegradability but large fractions of highly mobile PAHs, concluding that mass transfer limitations may only be one of many factors governing biodegradability of PAHs.

Adsorption↗

PubMed2006

Predicting phosphorus availability from soil-applied composted and non-composted cattle feedlot manure.

Prediction of phosphorus (P) availability from soil-applied composts and manure is important for agronomic and environmental reasons. This study utilized chemical properties of eight composted and two non-composted beef cattle (Bos taurus) manures to predict cumulative phosphorus uptake (CPU) during a 363-d controlled environment chamber bioassay. Ten growth cycles of canola (Brassica napus L.) were raised in pots containing 2 kg of a Dark Brown Chernozemic clay loam soil (fine-loamy, mixed, Typic Haploboroll) mixed with 0.04 kg of the amendments. Inorganic P fertilizer (KH2PO4) and an unamended control were included for comparison. All treatments received a nutrient solution containing an adequate supply of all essential nutrients, except P, which was supplied by the amendments. Cumulative P uptake was similar for composted (74 mg kg-1 soil) and non-composted manures (60 mg kg-1 soil) and for the latter and the fertilizer (40 mg kg-1 soil). However, the CPU was significantly higher for organic amendments than the control (24 mg kg-1 soil) and for composted manure than the fertilizer. Apparent phosphorus recovery (APR) from composted manure (24%) was significantly lower than that from non-composted manure (33%), but there was no significant difference in APR between the organic amendments and the fertilizer (27%). Partial least squares (PLS) regression indicated that only two parameters [total water-extractable phosphorus (TPH2O) and total phosphorus (TP) concentration of amendments] were adequate to model amendment-derived cumulative phosphorus uptake (ACPU), explaining 81% of the variation in ACPU. These results suggest that P availability from soil-applied composted and non-composted manures can be adequately predicted from a few simple amendment chemical measurements. Accurate prediction of P availability and plant P recovery may help tailor manure and compost applications to plant needs and minimize the buildup of bioavailable P, which can contribute to eutrophication of sensitive aquatic systems.

Animals↗

PubMed1992

The effect of Medicaid formularies on the availability of new drugs.

This study expands our previous work on the availability of new drug introductions to poor patients in states in the USA with restrictive Medicaid formularies. In particular, it focuses on the experience of 9 states over the period 1979 to 1985. In these states, a typical new drug took 20 months after FDA approval to gain acceptance onto the Medicaid formulary. New drug introductions were available to Medicaid patients less than 40% of the time during their first 4 years of market life. Restrictions on availability also extended to drugs ranked high in terms of both therapeutic and commercial importance. There was substantial variation observed across states and therapeutic categories. While formularies are prohibited under legislation recently enacted by the US Congress, state governments may attempt to continue to restrict access to expensive new medicines through prior approval systems. This is an issue that warrants future attention and study.

Drug Utilization↗

PubMed1992

Comparative potency and dissolution performance of internationally available piroxicam products.

Generic drug products are marketed throughout the world and are generally regarded as being equivalent to the name brand product. Piroxicam is a widely prescribed nonsteroidal anti-inflammatory drug and is marketed under the Pfizer tradename Feldene or Felden . In countries with no patent laws or where the Feldene patent has expired, the drug is available under various trademarks by many different producers. Differences in formulations produced by different manufacturers can be assessed by measuring dissolution rate and potency. In this study, the United States Pharmacopeia (USP) dissolution and potency tests were applied to 85 generic piroxicam products obtained from 21 countries in an attempt to evaluate if the available formulations met standard quality assurance tests. The results show that of the 85 piroxicam products tested, 17 products met the USP dissolution standards and 68 products failed. Of the 85 products tested for potency as a percentage of label claim, 50 products failed the USP criteria. Overall, 91% of the generic piroxicam products evaluated failed to meet the routine in vitro USP quality assurance criteria for potency and/or dissolution. The substantial differences observed in this study regarding performance of piroxicam dosage forms available worldwide have possible implications in terms of product equivalency and standards at an international level. While these results cannot be used to draw clinical conclusions without bioavailability data, they should nonetheless be kept in mind by healthcare practitioners.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemistry, Pharmaceutical↗

PubMed2004

Psychosocial conditions and the efficacy of clinically available anxiolytics.

The treatment of anxiety cannot be considered a solved problem, therefore, efforts are directed towards the development of novel treatment approaches. Increasing evidence suggests, however, that the efficacy of available treatments can be improved by taking into account the yet poorly known interactions between psychosocial conditions and the efficacy of pharmacological treatments. We review here evidence demonstrating that psychosocial factors affect the properties and function of receptors that mediate the effects of clinically available anxiolytics. Such neuronal changes affect the efficacy of anxiolytics, which consequently depends largely on psychosocial factors. We show that the interaction between psychosocial factors and drug responsiveness is clinically relevant. Laboratory studies predict that (i) the frequent exposure of subjects to acute stressors lowers the efficacy of benzodiazepines and buspirone, but increases the efficacy of selective serotonin reuptake inhibitors (SSRIs); (ii) the anxiolytic efficacy of buspirone is largely affected by social support and stability, whereas (iii) the efficacy of SSRIs is larger in subjects experiencing early maltreatment. Laboratory studies also show that the side effects of compounds decrease under certain conditions. Disparate human studies suggest that such predictions are clinically valid. Thus, further research on the relationship between psychosocial (Axis-IV) factors and drug efficacy would lead to substantial therapeutic progress with the available anxiolytic compounds. This interaction should be in focus also when new therapeutic approaches are developed.

Animals↗

PubMed2001

Contrast-enhanced carotid MR angiography with commercially available triggering mechanisms and elliptic centric phase encoding.

OBJECTIVE: The technical feasibility of contrast-enhanced MR angiography of the carotid arteries was evaluated with routinely available timing sequences and elliptic centric acquisition. The image quality of the contrast-enhanced MR angiography was compared with that of multiple overlapping thin-section acquisition MR angiography (MOTSA MR angiography). SUBJECTS AND METHODS: Sixty-three patients were enrolled. A 2-mL test bolus and commercially available software were used to time the gadolinium bolus. High-resolution contrast-enhanced MR angiography was performed with elliptic centric acquisition. RESULTS: The average time of bolus arrival was 17.3 sec (range, 12-25 sec). In 60 of the 63 patients, we had excellent or good visualization of the carotid bifurcation using contrast-enhanced MR angiography with little or no venous contamination. Two observers ranked delineation of stenosis and morphology of proximal internal carotid artery and overall diagnostic confidence statistically significantly higher for contrast-enhanced MR angiography compared with MOTSA: Ulceration, length of stenosis, and slow flow distal to a critical stenosis were better depicted with contrast-enhanced MR angiography than with MOTSA: Venetian blind artifact, saturation of slow or in-plane flow, and artifactual narrowing in carotid artery kinks plagued MOTSA but were not seen on contrast-enhanced MR angiography. MOTSA was graded superior to contrast-enhanced MR angiography in nine of 120 carotid bifurcations analyzed. CONCLUSION: High-resolution carotid contrast-enhanced MR angiography is technically feasible. We found a 95% success rate using commercially available hardware and software. The image quality with carotid contrast-enhanced MR angiography has improved so that it is equal or superior to the longer MOTSA in most patients.

Adult↗

PubMed2006

Prediction of diabetic foot ulcer occurrence using commonly available clinical information: the Seattle Diabetic Foot Study.

OBJECTIVE: The ability of readily available clinical information to predict the occurrence of diabetic foot ulcer has not been extensively studied. We conducted a prospective study of the individual and combined effects of commonly available clinical information in the prediction of diabetic foot ulcer occurrence. RESEARCH DESIGN AND METHODS: We followed 1,285 diabetic veterans without foot ulcer for this outcome with annual clinical evaluations and quarterly mailed questionnaires to identify foot problems. At baseline we assessed age; race; weight; current smoking; diabetes duration and treatment; HbA(1c) (A1C); visual acuity; history of laser photocoagulation treatment, foot ulcer, and amputation; foot shape; claudication; foot insensitivity to the 10-g monofilament; foot callus; pedal edema; hallux limitus; tinea pedis; and onychomycosis. Cox proportional hazards modeling was used with backwards stepwise elimination to develop a prediction model for the first foot ulcer occurrence after the baseline examination. RESULTS: At baseline, subjects were 62.4 years of age on average and 98% male. Mean follow-up duration was 3.38 years, during which time 216 foot ulcers occurred, for an incidence of 5.0/100 person-years. Significant predictors (P </= 0.05) of foot ulcer in the final model (hazard ratio, 95% CI) included A1C (1.10, 1.06-1.15), impaired vision (1.48, 1.00-2.18), prior foot ulcer (2.18, 1.61-2.95), prior amputation (2.57, 1.60-4.12), monofilament insensitivity (2.03, 1.50-2.76), tinea pedis (0.73, 0.54-0.98), and onychomycosis (1.58, 1.16-2.16). Area under the receiver operating characteristic curve was 0.81 at 1 year and 0.76 at 5 years. CONCLUSIONS: Readily available clinical information has substantial predictive power for the development of diabetic foot ulcer and may help in accurately targeting persons at high risk of this outcome for preventive interventions.

Aged↗

PubMed2002

Effect of commercially available nasal strips on airway resistance in exercising horses.

OBJECTIVE: To determine the effect of a commercially available nasal strip on airway mechanics in exercising horses. ANIMALS: 6 horses (5 Standardbreds and 1 Thoroughbred). PROCEDURE: Horses exercised on a treadmill at speeds corresponding to 100 and 120% of maximal heart rate with and without application of a commercially available nasal strip. Concurrently, tracheal pressures, airflow, and heart rate were measured. Peak inspiratory and expiratory tracheal pressures, airflow, respiratory frequency, and tidal volume were recorded. Inspiratory and expiratory airway resistances were calculated by dividing peak pressures by peak flows. Endoscopic examination of the narrowest point of the nasal cavity (ie, nasal valve) was performed in 1 resting horse before, during, and after application of a nasal strip. RESULTS: During exercise on a treadmill, peak tracheal inspiratory pressure and inspiratory airway resistance were significantly less when nasal strips were applied to horses exercising at speeds corresponding to 100 and 120% of maximal heart rate. Application of the nasal strip pulled the dorsal conchal fold laterally, expanding the dorsal meatus. CONCLUSIONS AND CLINICAL RELEVANCE: The commercially available nasal strip tented the skin over the nasal valve and dilated that section of the nasal passage, resulting in decreased airway resistance during inspiration. The nasal strip probably decreases the amount of work required for respiratory muscles in horses during intense exercise and may reduce the energy required for breathing in these horses.

Airway Resistance↗

PubMed2002

Can goats learn about foods through conditioned food aversions and preferences when multiple food options are simultaneously available?

The objective of this study was to determine the extent to which herbivores are able to use conditioned food aversions and preferences to learn about the nutritional and toxic properties of food plants, when food options are simultaneously available. Conditioned food aversions and preferences have been invoked as important mechanisms by which free-ranging herbivores optimize food selection by learning about the negative and positive consequences of consuming particular plant species through a series of encounters. In most previous tests of this hypothesis, access to individual test foods has been separated in time, giving animals the opportunity to associate particular foods with particular post-ingestive effects. We presented animals with a more complex scenario by offering test feeds simultaneously during the learning phase. Such a test is an important step in assessing the importance of conditioned food responses as mechanisms by which herbivores learn to select an optimal diet. We first assessed the ability of goats to learn about test foods and their post-ingestive effects, when different conifer species were offered on separate days during the learning phase and animals were dosed with compounds eliciting positive, negative, or neutral post-ingestive effects. We then investigated the ability of animals to learn to make appropriate choices when all potential test foods were simultaneously available during the learning phase. The results confirmed that goats can learn to associate particular foods with particular post-ingestive effects and adjust their diet selection accordingly. The success with which animals made such associations was greatly reduced when they were presented with test foods simultaneously during the learning phase. When test foods were simultaneously available, animals tended to select a mixed diet, thereby reducing their opportunity to learn about the post-ingestive effects of particular foods. The results suggest that caution is required in extrapolating results of artificial conditioning experiments to free-ranging herbivores. The results also suggest that reducing the risk of toxicity through selection of mixed diets is an important component of a successful foraging strategy.

Animal Feed↗

PubMed1987

Whither cytosolic estrogen receptor assays? A comparison of commercially available kits for estrogen receptor assay.

Frozen tissue sections and cytosols from 89 specimens of breast and ovarian tumours have been assayed for the presence of estrogen receptor (ER) or related protein using four commercially available monoclonal antibody methods. These were estrogen receptor enzyme immunoassay (ER-EIA), estrogen receptor enzyme immunocytochemical assay (ER-ICA), ER D5 antigen immunoradiometric assay and ER D5 antigen immunocytochemical assay. The results have been compared with those obtained using a standard dextran coated charcoal steroid binding assay (ER-DCC). The correlation coefficient (r) between ER-DCC and ER-EIA results was 0.72 while that of both monoclonal antibody cytosol methods and their respective immunocytochemical assays was 0.66. ER-ICA gave additional valuable information concerning receptor heterogeneity in breast cancer sections. However, the correlation between ER D5 antigen assays and both ER-DCC and ER-EIA was weak (r less than 0.4). We conclude that there are a number of methodological advantages in using the kit systems including their ability to detect receptor presence in small tumour specimens (e.g., "Tru-cut" biopsies) but that their usefulness is limited by the current lack of widely available monoclonal based methods for the concurrent determination of progestogen receptor. We believe that, once these are available, immunocytochemical technology could offer an alternative method of determining the steroid receptor concentration in both ovarian and breast tumours, thus obviating the need for costly and time-consuming cytosolic methods, with their inherent difficulties of quality control.

Adolescent↗

PubMed1982

Brain availability of monoamine precursors in adult coeliac disease.

Adults with untreated coeliac disease show signs of reduced central monoamine metabolism. The reason is obscure, and in the present study we investigated the brain availability of the monoamine precursors tryptophan and tyrosine in 11 untreated coeliac patients. The brain availability appeared to be unaffected in most of the patients, and the rise in serum tryptophan levels after oral casein administration was similar in coeliac and control subjects. Four of the 11 coeliac patients showed impaired brain availability with respect to tryptophan. Since they comprised all with a history of major psychiatric illness, this observation may have therapeutical implications for the management of depression in adult coeliac patients.

Adult↗

PubMed1989

Measurement by HPLC of desferrioxamine-available iron in rabbit kidneys to assess the effect of ischaemia on the distribution of iron within the total pool.

A method for the determination of desferrioxamine-available iron in tissue fractions is described which involves incubation with desferrioxamine, extraction of desferrioxamine and its iron-bound form, ferrioxamine, and quantitation of these two forms of the drug by reversed-phase hplc analysis. Chelatable iron levels in the 1-10 microMolar region could be accurately and reproducibly measured using this technique. The desferrioxamine-available iron levels in both the cortex and medulla of rabbit kidneys were significantly elevated (up to 2-fold) after the organs had been subjected to 2 hours warm ischaemia or 24 hours cold storage at 0 degrees C in hypertonic citrate solution. There was no change in the total iron content of the tissues under these circumstances and thus a redistribution of intracellular iron to more available pools had presumably taken place as a result of ischaemia. This redistribution of iron may be an important factor in the initiation of peroxidative damage to cell membranes upon reperfusion of the organ with oxygen.

Animals↗

PubMed1990

Availability of drugs and psychological proneness in opioid addiction.

The role of drug availability and psychological proneness in opioid addiction was examined using longitudinal data from the Drug Abuse Reporting Program (DARP). The sample included 424 addicts who were followed up and interviewed approximately 12 years after admission to treatment in the DARP, and for whom admission, during-treatment, and 6-year follow-up data were also available. Drug availability and proneness were both found to be important for drug use at any given time--from initial stages of addiction as well as in Year 12 of the follow-up--but proneness was rated as relatively more important for opioid use in the later stages of the addiction career. Proneness measures contributed more to the prediction of long-term drug use outcomes.

Adult↗

PubMed2003

Effect of dietary carbohydrate composition and availability on utilization of ruminal ammonia nitrogen for milk protein synthesis in dairy cows.

A trial with four ruminally and duodenally cannulated, late-lactation dairy cows was conducted to investigate the effect of dietary carbohydrate (CHO) composition and availability on ruminal ammonia N utilization and transfer into milk protein. Two diets were fed at 8-h intervals in a crossover design. The diets differed in CHO composition: the ruminally fermentable non-structural carbohydrates (RFSS) diet (barley and molasses) contained a larger proportion of ruminally available CHO in the nonstructural carbohydrate fractions and the ruminally fermentable fiber (RFNDF) diet (corn, beet pulp, and brewer's grains) contained a larger proportion of CHO in ruminally available fiber. Nitrogen-15 was used to label ruminal ammonia N and consequently microbial and milk N. Fermentation acids, enzyme activities, and microbial protein production in the rumen were not affected by diet. Ruminal ammonia concentration was lowered by RFNDF. Ruminal and total tract digestibility of nutrients did not differ between diets except that apparent ruminal degradability of crude protein was lower for RFNDF compared with RFSS. Partitioning of N losses between urine and feces was also not affected by diet. Milk yield and fat and protein content were not affected by treatment. Average concentration of milk urea N was lower for RFNDF than for RFSS. Proportion of milk protein N originating from ruminal microbial N (based on the areas under the 15N-enrichment curves) was higher for RFNDF than for RFSS. Cumulative recovery of 15N in milk protein was 13% higher for RFNDF than for RFSS indicating enhanced transfer of 15N-ammonia into milk protein with the former diet. The results suggested that, compared to diets containing higher levels of ruminally fermentable starch, diets providing higher concentration of ruminally fermentable fiber may enhance transfer of ruminal ammonia and microbial N into milk protein.

Ammonia↗