Changes in age-specific reproductive rates can have important implications for managing populations, but the number of female brown (grizzly) bears (Ursus arctos) observed in any one study is usually ...inadequate to quantify such patterns, especially for older females and in hunted areas. We examined patterns of reproductive maturation and senescence in female brown bears by combining data from 20 study areas from Sweden, Alaska, Canada, and the continental United States. We assessed reproductive performance based on 4,726 radiocollared years for free-ranging female brown bears (age ≥3); 482 of these were for bears ≥20 years of age. We modeled age-specific probability of litter production using extreme value distributions to describe probabilities for young- and old-age classes, and a power distribution function to describe probabilities for prime-aged animals. We then fit 4 models to pooled observations from our 20 study areas. We used Akaike's Information Criterion (AIC) to select the best model. Inflection points suggest that major shifts in litter production occur at 4-5 and 28-29 years of age. The estimated model asymptote (0.332, 95% CI = 0.319-0.344) was consistent with the expected reproductive cycle of a cub litter every 3 years (0.333). We discuss assumptions and biases in data collection relative to the shape of the model curve. Our results conform to senescence theory and suggest that female age structure in contemporary brown bear populations is considerably younger than would be expected in the absence of modern man. This implies that selective pressures today differ from those that influenced brown bear evolution.
Sternal osteomyelitis caused by Mycobacterium tuberculosis is rare; since the advent of modern antituberculous therapy, a limited number of detailed cases have been reported. Most patients were ...relatively young, free of underlying disease, and lived in a country in which tuberculosis is endemic. The disease presented indolently with sternal pain and swelling. Extrasternal disease is detectable in less than half. Diagnosis was based on histologic examination of infected tissues and mycobacterial cultures. Most patients recovered after surgical debridement and combination drug therapy. Tuberculous sternal osteomyelitis should be considered in patients with sternal pain and swelling.
This international handbook reflects on the development of the field of technology education. From reviewing how the field has developed and its current strengths, consideration is given to where the ...field might go and how it can be supported in this process.
From 1972 to 1988 55 patients underwent radical abdominal hysterectomy, pelvic lymph node dissection for treatment of FIGO Stage I cervical adenocarcinoma. A minimum of 60 months follow-up was ...available on all surviving patients. A detailed retrospective analysis was conducted to determine the influence of radical surgery on survival and to identify prognostic factors for recurrence. A bilateral salpingo-oophorectomy was included as part of the primary surgery in 52 the patients. Histologic subtypes included endocervical adenocarcinoma (44), papillary carcinoma (5), clear cell carcinoma (3), and adenosquamous carcinoma (3). The 5- and 10-year disease-free survival was 85.5%. The median follow-up of the surviving patients was 78.5 months (range, 60 to 240 months). Eight patients recurred, all but 1 of whom died of disease. Median time to recurrence was 28 months (range, 6 to 47 months). Five patients recurred beyond 24 months. One patient recurred locally, 5 recurred regionally, and 2 developed distant recurrences. Lymph node metastases (P < 0.0001), histologic grade (P < 0.0001), depth of invasion (P = 0.0001), presence of paracervical disease (P = 0.0034), and size of the lesion (P = 0.0059) were shown to be significant determinants of recurrence. Two of the 3 patients with a single involved lymph node recurred. Age, parity, history of oral contraceptive use, histologic subtype, and lymph vascular space involvement were not statistically significant determinants of recurrence. Adjuvant whole pelvic radiotherapy did not influence regional recurrence or survival but may decrease local recurrence. Radical abdominal hysterectomy pelvic lymph node dissection is an appropriate treatment of patients with Stage I cervical adenocarcinoma.
Alcoholic liver disease is the second most common indication for liver transplantation in the United States. The lack of alcoholism treatment studies led us to study motivational enhancement therapy ...(MET) plus naltrexone after transplant. The authors could not complete this study. Sixty alcoholic patients were to receive MET plus naltrexone or placebo for 6 months. Fifty men and 5 women were screened. Nine died and 15 were not approached. Of 31 approached, 20 were ineligible, 11 refused, and 5 entered but dropped out before completion. Barriers to posttransplant alcoholism included infirmity, intensive medical management, and denial for alcoholism treatment. Because 30%–50% of alcoholic patients drink after transplant, the authors suggest using MET alone pretransplant.
Adenylate cyclase activity and levels of guanine nucleotide regulatory proteins (G-proteins) were compared in platelets from normal and non-insulin-dependent diabetic (NIDDM) male subjects. Whilst no ...differences were noted in basal and NaF-stimulated cyclase activities the degree of stimulation achieved by both forskolin and prostaglandin, E
1 was lower by some 34 and 52% respectively, in platelet membranes from diabetic subjects compared with those from normal control subjects. Altered
α
1-adrenoceptor-mediated inhibition of prostaglandin E
1-stimulated adenylate cyclase activity was evident; it being some 34% lower in platelet membranes from diabetic subjects compared to controls. Analysis of G-protein α-subunits, using specific anti-peptide antisera, wshowed that platelets from all subjects exhibited the G
i-2 and G
i-3, but not the G
i-1 forms of the inhibitory G-protein ‘G
i’ and all expressed the 42 kDa species of α-subunits of the stimulatory G-protein G
s. Whilst platelets of siabetic subjects had levels of G
s whihch were comparable to those found in control subjects their levels of G
i-2 and G
i-3 were some 49 and 75%, respectively, of those found in platelets from control subjects. Its is suggested that changes in adenylate cyclase functioning and G-protein expression may contribute to altered platelet functioning in non-insulin-dependent diabetic subjects.
Several reference books and electronic resources for occupational and environmental physicians are reviewed, including "Encyclopedia of Occupational Health and Safety, 4th ed." by J. M. Stellman, ..."Public Health and Preventive Medicine, 14th ed." by R. B. Wallace, and "Physical and Biological Hazards in the Workplace" by P. Wald and G. Stave.
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