The effects of orbitofrontal lesions on the aggressive behavior of vervet monkeys (Cercopithecus aethiops sabaeus).

This study examined the role of the orbitofrontal cortex in the integration and expression of aggressive behavior in the vervet monkey (Cercopithecus aethiops sabaeus). Operated and unoperated controls were observed in two settings: In one they were confronted by a human observer and in the other they were members of a social group of conspecifics. Nine animals (four males and five females) underwent orbitofrontal lesions. Operated males and females threatened a human observer more postoperatively than preoperatively, but exhibited no change in the rate of aggressive behavior expressed toward conspecifics. However, operated monkeys were less effective in their aggressive encounters with conspecifics. Operated males lost a greater proportion of dyadic encounters; operated females participated less successfully in coalition-mediated aggression. The postoperative changes exhibited by vervets differed from those reported in rhesus monkeys (Macaca mulatta), which suggests that there may be considerable interspecific variability among Old World monkeys in the effects of orbital frontal lesions on aggressive behavior.     

Myelolipoma of adrenal gland

Myelolipoma of the adrenal gland is a rare, benign tumor of which only 17 clinical cases have been reported previously in the literature. We document 1 additional case and review the pathogenesis of the tumor, with emphasis on the theory of the tissue necrosis as the major stimulus of the myelolipomatous changes in the adrenals.     

Hypoxic cell turnover in different solid tumor lines

PURPOSE: Most solid tumors contain hypoxic cells, and the amount of tumor hypoxia has been shown to have a negative impact on the outcome of radiotherapy. The efficacy of combined modality treatments depends both on the sequence and timing of the treatments. Hypoxic cell turnover in tumors may be important for optimal scheduling of combined modality treatments, especially when hypoxic cell targeting is involved. METHODS AND MATERIALS: Previously we have shown that a double bioreductive hypoxic marker assay could be used to detect changes of tumor hypoxia in relation to the tumor vasculature after carbogen and hydralazine treatments. This assay was used in the current study to establish the turnover rate of hypoxic cells in three different tumor models. The first hypoxic marker, pimonidazole, was administered at variable times before tumor harvest, and the second hypoxic marker, CCI-103F, was injected at a fixed time before harvest. Hypoxic cell turnover was defined as loss of pimonidazole (first marker) relative to CCI-103F (second marker). RESULTS: The half-life of hypoxic cell turnover was 17 h in the murine C38 colon carcinoma line, 23 h and 49 h in the human xenograft lines MEC82 and SCCNij3, respectively. Within 24 h, loss of pimonidazole-stained areas in C38 and MEC82 occurred concurrent with the appearance of pimonidazole positive cell debris in necrotic regions. In C38 and MEC82, most of the hypoxic cells had disappeared after 48 h, whereas in SCCNij3, viable cells that had been labeled with pimonidazole were still observed after 5 days. CONCLUSIONS: The present study demonstrates that the double hypoxia marker assay can be used to study changes in both the proportion of hypoxic tumor cells and their lifespan at the same time. The present study shows that large differences in hypoxic cell turnover rates may exist among tumor lines, with half-lives ranging from 17-49 h.     

Basal insulin levels in a Zulia State population in Venezuela

This study examines the basal insulin levels in a population from Zulia state (Venezuela). A total of 1703 subjects (1175 women and 528 men) from five different sanitary regions (Maracaibo, La Guajira, Perijá, Sur del Lago de Maracaibo, y Costa Oriental del Lago de Maracaibo) were studied. Weight, height, waist and hip circumferences, and blood pressure were determined. A blood sample was taken after a 12-h overnight fast to determine serum glucose, triglycerides, total cholesterol and HDL-C using enzymatic methods and insulin by radioimmunoassay. According to ATP III criteria two groups were established: a group without metabolic abnormalities (138 subjects) and a group with some metabolic abnormalities 84.8% of subjects of the non metabolic alteration groups and 80.4% of the group with some metabolic alteration were of mixed race. Non metabolic altered lean subjects (BMI <25 Kg/m2) had the lowest (p < 0.0001) basal insulin levels compared to the ones with overweight from the same group and the obese with metabolic abnormalities. This study proposes to consider a cutoff basal insulin levels of 13 microU/mL for women and 11 microU/mL for men, over 20 years of age, in the Zulia state region of Venezuela.     

Gist memory in Alzheimer's disease: evidence from categorized pictures

The authors investigated gist memory (the general meaning, idea, or gist conveyed by a collection of items) for categorized color photographs in patients with Alzheimer's disease (AD) using an experimental paradigm in which participants are instructed to respond "yes" when a test item fits with a previously studied category, regardless of whether the specific item was actually studied. Compared with controls, the patients endorsed fewer studied items and similar numbers of nonstudied lure items. After the authors corrected for the baseline false-alarm rate, the patients showed a lower level of endorsements for nonstudied lure items compared with that of controls, suggesting that their gist memory is impaired. Implications of these findings for understanding gist memory and response bias in patients with AD are discussed.     

Can High‐Risk Older Drivers Be Identified Through Performance‐Based Measures in a Department of Motor Vehicles Setting?

OBJECTIVES: To evaluate the relationship between performance-based risk factors and subsequent at-fault motor vehicle collision (MVC) involvement in a cohort of older drivers. DESIGN: Prospective cohort study. SETTING: Motor Vehicle Administration (MVA) field sites in Maryland. PARTICIPANTS: Of the 4,173 older drivers invited to participate in the study, 2,114 individuals aged 55 to 96 agreed to do so. These analyses focus on 1,910 individuals recruited through MVA field sites. MEASUREMENTS: Gross Impairment Screening Battery, which included Rapid Pace Walk, Head/Neck Rotation, Foot Tap, Arm Reach, Cued Recall, Symbol Scan, Visual Closure subtest of the Motor Free Visual Perception Test (MVPT), Delayed Recall, and Trail Making Test with an Abbreviated Part A and standard Part B; Useful Field of View (UFOV) subtest 2; a Mobility Questionnaire; and MVC occurrence. RESULTS: In drivers aged 55 and older with intact vision (20/70 far visual acuity and 140 degrees visual field), age, sex, history of falls, and poorer cognitive performance, as measured using Trails B, MVPT, and UFOV subtest 2, were predictive of future at-fault MVC involvement. After adjusting for annual mileage, participants aged 78 and older were 2.11 as more likely to be involved in an at-fault MVC, those who made four or more errors on the MVPT were 2.10 times as likely to crash, those who took 147 seconds or longer to complete Trails B were 2.01 times as likely to crash, and those who took 353 ms or longer on subtest 2 of the UFOV were 2.02 times as likely to incur an at-fault MVC. Older adults, men, and individuals with a history of falls were more likely to be involved in subsequent at-fault MVCs. CONCLUSION: Performance-based cognitive measures are predictive of future at-fault MVCs in older adults. Cognitive performance, in particular, is a salient predictor of subsequent crash involvement in older adults. High-risk older drivers can be identified through brief, performance-based measures administered in a MVA setting.     

Risk of stroke in people with type 2 diabetes in the UK: a study using the General Practice Research Database

Aims/hypothesis Risk estimates for stroke in patients with diabetes vary. We sought to obtain reliable risk estimates for stroke and the association with diabetes, comorbidity and lifestyle in a large cohort of type 2 diabetic patients in the UK.Materials and methods Using the General Practice Research Database, we identified all patients who had type 2 diabetes and were aged 35 to 89 years on 1 January 1992. We also identified five comparison subjects without diabetes and of the same age and sex. Hazard ratios (HRs) for stroke between January 1992 and October 1999 were calculated, and the association with age, sex, body mass index, smoking, hypertension, atrial fibrillation and duration of diabetes was investigated.Results The absolute rate of stroke was 11.91 per 1,000 person-years (95% CI 11.41–12.43) in people with diabetes (n = 41,799) and 5.55 per 1,000 person-years (95% CI 5.40–5.70) in the comparison group (n = 202,733). The age-adjusted HR for stroke in type 2 diabetic compared with non-diabetic subjects was 2.19 (95% CI 2.09–2.32) overall, 2.08 (95% CI 1.94–2.24) in men and 2.32 (95% CI 2.16–2.49) in women. The increase in risk attributable to diabetes was highest among young women (HR 8.18; 95% CI 4.31–15.51) and decreased with age. No investigated comorbidity or lifestyle characteristic emerged as a major contributor to risk of stroke.Conclusions/interpretation This study provides risk estimates for stroke for an unselected population from UK general practice. Patients with type 2 diabetes were at an increased risk of stroke, which decreased with age and was higher in women. Additional risk factors for stroke in type 2 diabetic patients included duration of diabetes, smoking, obesity, atrial fibrillation and hypertension.     

Psychological morbidity,sources of stress and coping strategies among undergraduate medical students of Nepal

Background  

In recent years there has been a growing appreciation of the issues of quality of life and stresses involved medical training as this may affect their learning and academic performance. However, such studies are lacking in medical schools of Nepal. Therefore, we carried out this study to assess the prevalence of psychological morbidity, sources and severity of stress and coping strategies among medical students in our integrated problem-stimulated undergraduate medical curriculum.