PubMed Health⌕ Search

Biomedical subjects

A Woolf

Publications and source records attributed to A Woolf.

At least 55 records · Page 3Linked to original sources
PubMed1992

Multiple-dose sodium polystyrene sulfonate in lithium intoxication: an animal model.

Previous work in our laboratory has demonstrated that sodium polystyrene sulfonate (SPS) significantly lowered serum lithium (Li) concentrations when administered in a single oral dose after an oral dose of lithium in a mouse model. The present study was designed to determine whether: 1) repetitive doses of SPS are effective in lowering serum lithium concentrations, 2) the effect of SPS on lithium concentration is dose related and 3) SPS enhances the elimination of lithium. Mice (N = 144) were given orogastric LiCl (250 mg/kg) and then divided into 4 groups: Controls received water 0, 30, 90, 180, and 360 min. after LiCl; the Full-Dose SPS Group received SPS (5 g/kg/dose) at equivalent times; the Half-Dose SPS Group received SPS (2.5 g/kg/dose) at the same times; and the Elimination Group received water at 0 and 30 min. after LiCl and SPS at 90, 180 and 360 min. after LiCl. Subgroups of each group were sacrificed at 1, 2, 4 and 8 hr post-treatment and serum analyzed for lithium concentrations. Statistical analyses revealed that, when compared to Controls: 1) SPS significantly lowered serum lithium concentrations; 2) this effect was dose-related; 3) repetitive dosing of SPS appears to enhance the elimination of lithium.

Animals↗
PubMed1992

Prevalence of spindle cell sarcomas among wild Canada geese from southern Illinois.

Over a 6-yr period, two cases of neoplastic disease were diagnosed among 1,272 wild Canada geese (Branta canadensis interior) collected in Illinois (USA), Wisconsin (USA), and Ontario, Canada. One juvenile goose of each sex was involved. In both cases > 35 discrete masses were observed subdermally, intramuscularly, and within the body cavity. The tumors, diagnosed as spindle cell sarcomas, are among the most commonly observed neoplasms in free-living North American waterfowl. Based on our data, we suggest that these neoplasms occur with extremely low prevalence (0.002%) in free-living Canada geese.

Animals↗
PubMed1992

Care of elderly patients with a fractured neck of femur.

This survey was designed to compare the clinical management of elderly patients admitted to hospitals with a hip fracture, with the recommendations in the recent Royal College of Physicians report "Fractured Neck of Femur". The results highlight large discrepancies between the 'ideal' clinical management as recommended, and that which occurs in practice. Particular concerns include the lack of experienced medical supervision provided for patients perioperatively, the high proportion of junior anaesthetic and surgical staff performing the operation, and the widespread poor rehabilitation facilities. These findings suggest that, unless the quality of clinical care for such patients is vastly improved, the predicted exponential rise in the number of elderly people sustaining a hip fracture will create a heavy burden on scarce National Health Service resources.

Aged↗
PubMed1992

The OPQ: a proposed instrument for predicting poisoning accident recurrence in young children.

A 26-item self-report questionnaire for parents/guardians was constructed for potential use with first-exposure childhood poisoning victims to predict high risk for subsequent poisoning episodes. Data were obtained from 185 subjects served by 1 of 5 US regional poison control centers. The resulting device was labeled the OPQ. Its retrospective validity (R = 0.71) and test-retest reliability (0.81) are viewed as sufficient. The test itself, with accompanying scoring key and norms, are provided here in the hope that other clinicians and researchers will join in subjecting the OPQ to prospective validity studies and other forms of Scale refinement.

Child, Preschool↗
PubMed1992

Parasites of cottontail rabbits of southern Illinois.

Fifteen species of parasites including Haemaphysalis leporispalustris, Ixodes dentatus, Amblyomma americanum, Cediopsylla simplex, Odontopsyllus multispinosus, Cuterebra sp., Obeliscoides cuniculi, Trichostrongylus calcaratus, Trichostrongylus affinis, Longistriata noviberiae, Dermatoxys veligera, Trichuris sp., Mosgovoyia sp., Taenia pisiformis, and Hasstilesia tricolor as well as coccidia oocysts were collected from 96 cottontail rabbits (Sylvilagus floridanus) confined to a pen in southern Illinois in 1983 and 1984. The diversity of parasites and the intensities of infections were similar to published reports on free-ranging populations. Most variations in parasite abundances were attributable to season. Few lesions were seen in association with parasitism.

Age Factors↗
PubMed1991

Reinitiation of spermatogenesis by exogenous gonadotropins in a seasonal breeder, the woodchuck (Marmota monax), during gonadal inactivity.

The present study was undertaken (1) to document structural and functional changes in the testes of seasonally breeding woodchuck during active and inactive states of spermatogenesis and (2) to evaluate the ability of exogenous gonadotropins to reinitiate spermatogenesis outside the breeding season. During seasonal gonadal inactivity, there were significant (P less than 0.05) reductions in volumes of several testicular features (testis, seminiferous tubules, tubular lumen, interstitial tissue, individual Leydig cells, Leydig cell nuclei, and Leydig cell cytoplasm) as compared with gonadally active animals. The diameter of the seminiferous tubules was decreased by 26%, and Leydig cell numbers also declined in the regressed testes. These changes were accompanied by a decline in testosterone (T) levels in both plasma and testis, and reduction in epithelial height of accessory reproductive organs. A hormonal regimen was developed that would reinitiate spermatogenesis in captive, sexually quiescent woodchucks. A combination of PMSG and hCG markedly stimulated testicular growth and function and restored spermatogenesis qualitatively. Quantitatively normal spermatogenesis was restored in 2 of 6 treated males. Morphometric analyses revealed substantial increases in seminiferous tubular diameter and in the volume of seminiferous tubules, tubular lumen, total Leydig cells, and individual Leydig cells in the hormone-treated animals. These increased values corresponded to 99, 75, 68, 51, and 200%, respectively, of the values measured in naturally active woodchucks. Leydig cell numbers, however, remained unchanged and approximated only 31% of the number found in naturally active testes. Hormonal stimulation also resulted in a significant rise in serum T as well as in the total content of testicular T, and a marked increase in epithelial height in various accessory reproductive glands. The most effective hormonal protocol for stimulating spermatogenesis was treatment with 12.5 IU of PMSG twice a week for 4 weeks followed by 12.5 IU of PMSG + 25 IU of hCG twice a week for 4 weeks.

Animals↗
PubMed1991

Screening for vertebral osteoporosis using individual risk factors. The Multicentre Vertebral Fracture Study Group.

Osteoporosis is a major cause of ill health in postmenopausal women. Several risk factors for osteoporosis have been identified, and they have been widely recommended as a means of identifying subgroups of postmenopausal women who might benefit from prophylaxis and therapy. Evidence to support this use of risk factors is currently lacking, however. We have constructed and evaluated a profile of putative risk factors as a means of identifying women attending general practitioners who have sustained vertebral fractures. The overall prevalence of vertebral fractures in the 1012 women (mean age 64.4 years) studied was 7.8%. Women who had sustained vertebral fractures in this population were significantly (p less than 0.05) older and shorter than those without fractures. They reported a significantly (p less than 0.05) earlier menopause, lower parity and a greater prevalence of hyperthyroidism. However, the best screening instrument devised was not sufficiently predictive to warrant widespread use.

Aged↗
PubMed1991

Monitoring cyanide and thiocyanate concentrations during infusion of sodium nitroprusside in children.

Over a 19-month period, all requests for blood cyanide and/or serum thiocyanate concentrations to the Clinical Laboratory of The Children's Hospital, Boston, were reviewed in order to determine how physicians screen for nitroprusside-related toxicity. During that period, 52 patients receiving nitroprusside were monitored for cyanide and/or thiocyanate toxicity. Overall, there were 62 cyanide and 86 thiocyanate determinations. None of the thiocyanate determinations and five of the cyanide concentrations were within the toxic range as established by the reference laboratory, and no patient displayed signs or symptoms of toxicity which could not also be explained by their underlying illness. Our findings suggest that while physicians are concerned with nitroprusside toxicity in children, there exists no apparent consensus as to how to monitor for this toxicity. The results also indicate that the relationship between blood cyanide or serum thiocyanate concentrations and clinical evidence of toxicity is not straightforward and requires further delineation.

Adolescent↗
PubMed1991

Seasonal variations in circulating levels of progesterone and estradiol in unmated adult female woodchucks (Marmota monax) in captivity.

The annual profile of serum levels of progesterone (P) and estradiol-17 beta (E2) was characterized in a seasonally breeding rodent, the woodchuck (Marmota monax). Hormonal levels were determined in serum samples taken at weekly or biweekly intervals from unmated female woodchucks maintained all year indoors under controlled conditions of photoperiod and temperature. Annual fluctuations included a rise of E2 levels during late January through February, followed by a modest increase in plasma P concentrations by late March, the latter attaining peak values during April and May. A temporal dissociation of peak values of circulating levels of P and E2 during the annual reproductive cycle was also detected. The timing of changes in serum levels of P and E2 in these captive woodchucks corresponded to reproductive events during the normal breeding season of the woodchuck in the southern part of its range.

Animals↗
PubMed1991

The adsorption of salicylates by a milk chocolate-charcoal mixture.

STUDY OBJECTIVE: To evaluate the adsorptive capacity of a milk chocolate-charcoal mixture to aspirin, compared with superactivated charcoal and conventional activated charcoal. DESIGN: A prospective, randomized, crossover study. SETTING: The Massachusetts Poison Control Center office in The Children's Hospital, Boston. TYPE OF PARTICIPANTS: Six healthy adult volunteers with no known allergies to aspirin or chocolate, bleeding disorders, or peptic ulcer disease. INTERVENTIONS: Each participant ingested 975 mg of crushed aspirin on separate days, followed by either water; 10 g milk chocolate-charcoal mixture; 10 g SuperChar Liquid; or 10 g Actidose Aqua activated charcoal. Total serum salicylate concentrations were determined by high-performance liquid chromatography at zero, one, two, four, eight, and 24 hours after ingestion. MEASUREMENTS AND MAIN RESULTS: Neuman-Keuls analysis was used to measure time-to-peak concentration, which was reduced by SuperChar Liquid, 67%; milk chocolate-charcoal mixture, 106%; and activated charcoal, 56%. Aspirin absorption was calculated using Neuman-Keuls analysis to measure area under the concentration-time curve. Total aspirin absorption was reduced by SuperChar, 67%; milk chocolate-charcoal mixture, 50%; and activated charcoal, 2%. There was no difference in serum salicylate concentrations between SuperChar and milk chocolate-charcoal mixture at all time intervals. Also, all serum salicylate concentrations with milk chocolate-charcoal mixture were consistently lower than with activated charcoal. CONCLUSION: Although the formulation of milk chocolate with activated charcoal reduces its adsorptive capacity compared with superactivated charcoal, it is still able to bind aspirin effectively and is superior to conventional activated charcoal. Further research may improve the binding and palatability of milk chocolate-charcoal mixture, especially for home use.

Adsorption↗
PubMed1991

The estrous cycle of captive woodchucks (Marmota monax).

Changes in vaginal cytology were assessed and correlated with temporal changes in circulating concentrations of progesterone (P) and estradiol-17 beta (E2) during the breeding season (February to March) in a seasonally breeding rodent, the woodchuck (Marmota monax). Ten individually caged adult females, maintained under laboratory conditions for 3-11 mo, were studied. Vaginal smears were taken each morning for 2 consecutive months beginning 1 February 1990. Seven of 10 females exhibited readily identifiable estrus, characterized by a clear predominance (83%) of cornified cells. The earliest estrous smear was recorded on 3 February and the latest on 12 March. These animals were monoestrous and remained in a prolonged estrous period during their brief breeding season. The average duration of estrus was 18.1 +/- 2.1 days, ranging from 12-27 days. Levels of P and E2 were determined in serum samples taken before, during, and after estrus from 7 females who exhibited estrus. No changes in the circulating levels of P were apparent during the estrous cycle. However, there was a consistent pattern of estradiol secretion characterized by elevated levels of E2 before and during estrus, followed by a significant (p less than 0.05) decline in E2 levels one week after the end of estrus. Elevated levels of E2 preceded and coincided with maximal degree of vaginal cornification. Thus, the termination, but not the onset, of estrus in woodchucks reflected closely the temporal pattern of changes in serum E2 levels during the breeding season.

Animals↗
PubMed1991

Hematology and serum chemistry of cottontail rabbits of southern Illinois.

In 1983 and 1984 blood was collected from 79 cottontail rabbits (Sylvilagus floridanus) confined to an outdoor enclosure in southern Illinois to establish reference values for hematology and serum chemistry. Packed cell volume, sodium, potassium, chloride, glucose, calcium, carbon dioxide, blood urea nitrogen, creatinine, uric acid, cholesterol, albumin, bilirubin, alkaline phosphatase, aspartate transaminase, alanine aminotransaminase, total protein, albumin/globulin ratio, and osmolality were measured. Sex and age (adult versus juvenile) of rabbit as well as season (June to September versus October to May) and method of capture (trap versus shot) variously affected most hematology and serum chemistry variables.

Animals↗
PubMed1990

Serum magnesium concentrations after repetitive magnesium cathartic administration.

Severe hypermagnesemia has been reported by several authors after multiple doses of magnesium-containing cathartic are administered during management of a toxic ingestion. To evaluate the frequency and magnitude of serum magnesium elevations after the use of repetitive magnesium catharsis, we prospectively evaluated 102 patients who received multiple doses of magnesium citrate as a part of treatment of an overdose. Commonly ingested substances for which repetitive cathartic was administered were tricyclic antidepressants in 47%, aspirin in 17%, and phenytoin in 10%. For each case, serial electrolytes, blood urea nitrogen, creatinine, calcium and magnesium were obtained. Mean initial serum magnesium concentration was 1.8 +/- .03 mEq/L. After a mean 960 mL of magnesium citrate (9.22 g magnesium), final mean serum magnesium concentration was 2.5 +/- .05 mEq/L. Forty-seven patients (47%) developed an elevated (greater than 2.4 mEq/L) serum magnesium concentration, with 12 greater than 3.0 mEq/L. No correlation was found between total quantity of magnesium citrate administered and the increment in serum magnesium concentration. Our data indicate that serum magnesium concentrations consistently rise after repetitive magnesium citrate use. However, the magnitude of this rise appears modest. The elevation in serum magnesium concentration does not correlate with the quantity of magnesium administered. We conclude that with close monitoring, repetitive magnesium citrate can be administered without inducing severe hypermagnesemia (serum magnesium concentration greater than 5.0 mEq/L).

Adolescent↗
PubMed1990

Serious poisonings among older adults: a study of hospitalization and mortality rates in Massachusetts 1983-85.

We analyzed poisoning-related hospitalization and mortality rates among older adults living in Massachusetts during 1983-85. While poisoning-related hospitalization rates of individuals greater than or equal to 60 years were near the state average, death rates for men greater than or equal to 70 years and for women over 60 were higher than those of younger individuals. Medications and carbon monoxide were commonly implicated agents in these poisoning deaths. Older adults are more vulnerable to death from a poisoning than are younger age groups.

Aged↗
PubMed1990

Serological prevalence of tularemia in cottontail rabbits of southern Illinois.

Sera of cottontail rabbits (Sylvilagus floridanus) collected in southern Illinois in 1983 and 1984 were screened for the presence of antibodies against Francisella tularensis by rapid slide agglutination and enzyme linked immunosorbent assay techniques; 6% of 118 and 16% of 119 samples were positive by these methods, respectively. Rabbits gained, lost and maintained titers over at least an 8 mo period. Francisella tularensis tularensis was isolated from one serologically negative, clinically healthy rabbit.

Agglutination Tests↗