Age does not influence the bone response to treadmill exercise in female rats

PURPOSE: Because it is believed that bone may respond to exercise differently at different ages, we compared bone responses in immature and mature rats after 12 wk of treadmill running. METHODS: Twenty-two immature (5-wk-old) and 21 mature (17-wk-old) female Sprague Dawley rats were randomized into a running (trained, P = 10 immature, 9 mature) or a control group (controls, P = 12 immature, 12 mature) before sacrifice 12 wk later. Rats ran on a treadmill five times per week for 60-70 min at speeds up to 26 m.min. Both at baseline and after intervention, we measured total body, lumbar spine, and proximal femoral bone mineral, as well as total body soft tissue composition using dual-energy x-ray absorptiometry (DXA). After sacrificing the animals, we measured dynamic and static histomorphometry and three-point bending strength of the tibia. RESULTS: Running training was associated with greater differences in tibial subperiosteal area, cortical cross-sectional area, peak load, stiffness, and moment of inertia in immature and mature rats (P < 0.05). The trained rats had greater periosteal bone formation rates (P < 0.01) than controls, but there was no difference in tibial trabecular bone histomorphometry. Similar running-related gains were seen in DXA lumbar spine area (P = 0.04) and bone mineral content (BMC; P = 0.03) at both ages. For total body bone area and BMC, the immature trained group increased significantly compared with controls (P < 0.05), whereas the mature trained group gained less than did controls (P < 0.01). CONCLUSION: In this model, where a similar physical training program was performed by immature and mature female rats, we demonstrated that both age groups were sensitive to loading and that bone strength gains appeared to result more from changes in bone geometry than from improved material properties.     

Attitudes of part-time community internal medicine faculty about their teaching.

The authors sent a six-item questionnaire regarding attitudes about teaching to 130 part-time community internal medicine faculty at the University of Illinois College of Medicine at Rockford in August 1991; of the 90 (69%) who responded, 53 were salaried and 37 nonsalaried. Substantial numbers of the salaried faculty responded (1) that teaching is important for their career development (25, 48%), compared with nine (22%) of the nonsalaried faculty, and (2) that they expected to increase their commitments to the medical school (50, 75%), compared with 24 (65%) of the nonsalaried faculty. Of all the faculty, fewer than the authors expected--22 (24%)--felt that their teaching interfered with their clinical practices. As expected, most (76, 84%) responded that salary was necessary. The authors suggest that their results may be helpful to other medical schools, because with the setting of medical education changing from the hospital to the community, the importance of part-time faculty is increasing.     

Mutations in <Emphasis Type="Italic">APC</Emphasis>, <Emphasis Type="Italic">CTNNB1</Emphasis> and <Emphasis Type="Italic">K-ras</Emphasis> genes and expression of hMLH1 in sporadic colorectal carcinomas from the Netherlands Cohort Study

Background  

The early to intermediate stages of the majority of colorectal tumours are thought to be driven by aberrations in the Wnt (APC, CTNNB1) and Ras (K-ras) pathways. A smaller proportion of cancers shows mismatch repair deficiency. The aim of this study was to analyse the co-occurrence of these genetic alterations in relation to tumour and patient characteristics.     

Discordant mental and physical efforts in an autistic patient

We investigated whether there was mental effort in response to verbal commands in a 16-year old girl with autism, a high degree of non-compliance with commands and symptoms of autonomic dysfunction by monitoring the brainstem autonomic tone during an attempt to perform isometric exercise. An index of cardiac vagal tone (CVT), cardiac sensitivity to baroreflex (CSB), heart rate (HR) and mean arterial blood pressure (MAP) were measured simultaneously. Physical non-compliance with our commands meant there was no force applied by the patient during the attempted exercise, but CVT and CSB were both reduced and sustained at very low levels throughout the attempt, while MAP and HR were increased concurrently to higher levels in the same period. This vagal withdrawal to allow concurrent increases in HR and MAP is an arousal response appropriate for isometric exercise, which is a sign of a positive mental effort to comply with our commands. These results demonstrate discordant mental and physical efforts in our patient. In this particular case, the physical inabilities in some instances could have been mislabelled as mental non-compliance due to autism. It would be worthwhile to investigate the prevalence of discordant mental and physical efforts in autism.     

Central abdominal fat and endogenous hormones during the menopausal transition

OBJECTIVE: To investigate the effect of endogenous hormone levels on central abdominal fat during the menopausal transition in a population-based cohort of Australian-born women. DESIGN: Prospective observational study. SETTING: Population-based sample. Body composition was assessed in the Royal Melbourne Hospital, and interviews were conducted at the patient's home. SUBJECT(S): One hundred two women from the Melbourne Women's Midlife Health Project. Data, physical measures, and blood were obtained by interview when the longitudinal study commenced (baseline) and at the time of the total body scan approximately 5 years later. Body composition was measured using dual-energy X-ray absorptiometry. INTERVENTION(S): None. MAIN OUTCOME MEASURES: Total body fat and central abdominal fat. RESULT(S): The 102 women were either premenopausal or in the early menopausal transition at baseline. At the time of their dual-energy X-ray absorptiometry scan, 31 were in the early menopausal transition, 22 were in the late menopausal transition, and 49 were postmenopausal. Multiple regression analysis found that total percentage of body fat was associated with weight measures, whereas central abdominal fat was also positively associated with baseline free T index (FTI) and with the increase in FTI since baseline. CONCLUSION(S): The major hormonal change associated with central adiposity during the menopausal transition is the increase in the FTI. This effect is significant even after allowing for baseline and final weight.     

An effective, economic way of monitoring menstrual cycle hormones in at risk female athletes

PURPOSE: Female athletes, in response to intensive training, competition stress and a lean, athletic physique, are at increased risk of altered hypothalamic-pituitary ovarian (HPO) axis function associated with menstrual cycle disturbance and reduced secretion of the ovarian hormones estrogen and progesterone. Because there is evidence suggesting possible detrimental effects on skeletal health associated with deficiencies in these hormones, a suitable means to asses ovarian hormone concentrations in at risk athletes is needed. The aim of this study was to evaluate a simple, economical means to monitor the ovarian hormone production in athletes, in the setting of intensive training. METHODS: Subjects comprised 14 adolescent rowers, 12 lightweight rowers, and two groups of 10 matched control subjects. Ovarian function was monitored during the competition season by estimation of urinary excretion of estrone glucuronide (E1G) and pregnanediol glucuronide (PdG), enabling the menstrual cycles to be classified as ovulatory or anovulatory. RESULTS: Results indicated 35% and 75% of schoolgirl and lightweight rowers had anovulatory menstrual cycles, respectively. These findings were highlighted by significantly lower excretion of E1G and PdG during phases of intensive training in both the lightweight and schoolgirl rowers, compared with the control subjects. CONCLUSION: It was concluded that the urinary E1G and PdG assays were an effective means to assess the influence of intense training on ovarian hormone concentrations in at risk athletes. It is recommended that this technique be applied more widely as a means of early detection of athletes with low estrogen and progesterone levels, in an attempt to avoid detrimental influences on skeletal health.     

A case report on fixation instability in Parkinson's disease with bilateral deep brain stimulation implants

We report on fixation instabilities in a patient diagnosed with Parkinson's disease (PD). This patient underwent deep brain stimulation (DBS) surgery bilaterally in the vicinity of the subthalamic nuclei (STN). Examination of the eye movements of this patient revealed marked fixation instability compared with a healthy age matched control. The eye movements occurring during fixation differed from other reports of fixation instabilities in that they interrupted fixation for only brief durations. These interruptive saccades (IS) had saccade-like amplitude velocity relationships. The frequency of these IS was higher in the patient with PD than in the healthy age matched control. Furthermore, the frequency of the IS in the patient reduced toward control with application of bilateral DBS in the vicinity of the STN. From our observations we conclude that fixation ability may be altered in PD and improved with DBS.     

The Role of Diet in the Pathogenesis and Management of Inflammatory Bowel Disease: A Review

Inflammatory bowel diseases, which include ulcerative colitis and Crohn’s disease, are chronic relapsing and remitting inflammatory diseases of the gastrointestinal tract that are increasing in prevalence and incidence globally. They are associated with significant morbidity, reduced quality of life to individual sufferers and are an increasing burden on society through direct and indirect costs. Current treatment strategies rely on immunosuppression, which, while effective, is associated with adverse events. Epidemiological evidence suggests that diet impacts the risk of developing IBD and modulates disease activity. Using diet as a therapeutic option is attractive to patients and clinicians alike due to its availability, low cost and few side effects. Diet may influence IBD risk and disease behaviour through several mechanisms. Firstly, some components of the diet influence microbiota structure and function with downstream effects on immune activity. Secondly, dietary components act to alter the structure and permeability of the mucosal barrier, and lastly dietary elements may have direct interactions with components of the immune response. This review will summarise the mechanisms of diet–microbial–immune system interaction, outline key studies examining associations between diet and IBD and evidence demonstrating the impact of diet on disease control. Finally, this review will outline current prescribed dietary therapies for active CD.     

Induced sputum eosinophils and neutrophils and bronchiectasis severity in allergic bronchopulmonary aspergillosis.

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity reaction to the fungus Aspergillus fumigatus that may progress to bronchiectasis. The aim of the present study was to characterize airway inflammation in patients with clinically stable ABPA and asthma, and to correlate this with bronchiectasis severity. Subjects with ABPA and central bronchiectasis (ABPA-CB; n=16) and ABPA with serological evidence alone (ABPA-S; n=10) were studied. Comparison groups were A. fumigatus-sensitized asthma (n=19), non-A. fumigatus-sensitized asthma (n=15) and healthy controls (n=8). Hypertonic saline challenge, sputum induction and high-resolution computed tomography (HRCT) of the chest were performed. Sputum eosinophil numbers were markedly elevated in ABPA-CB (median 8.4%) compared to ABPA-S (2.4%), A. fumigatus-sensitized asthma (1.8%), asthma (1.8%) and controls (0.3%) (p<0.01); sputum eosinophil cationic protein levels were higher in ABPA-CB (median 13,706 ng.mL(-1)), compared to ABPA-S (1,633.5 ng.mL(-1)), A. fumigatus-sensitized asthma (1,550.7 ng.mL(-1)), asthma (309.2 ng.mL(-1)), and controls (110 ng.mL(-1)) (p<0.001). ABPA-CB also showed increased sputum neutrophil number (median 60.3%) compared to the other groups (controls 29.3%) (p=0.01). The severity of bronchiectasis on HRCT correlated with sputum neutrophil (r=0.6) and eosinophil number (r=0.5) but not serum immunoglobulin-E levels. In conclusion, clinically stable allergic bronchopulmonary aspergillosis with bronchiectasis is characterized by an intense heterogenous inflammatory infiltrate consisting of eosinophils and neutrophils, which correlates closely with the severity of bronchiectasis on high-resolution computed tomography. Sputum analysis may be useful in monitoring the course of allergic bronchopulmonary aspergillosis.