Small intestine ischemia simulating primary colonic disease

Clinical and radiographic findings were reviewed for four patients in whom colonic diverticulitis was suspected clinically but in whom small intestine ischemia was proved surgically. In each patient the initial diagnostic studies--plain abdominal radiography and barium enema examination--revealed generalized small intestine distention and non-specific colonic abnormalities, respectively. The latter findings consisted of an extrinsic impression on the superior or inferior aspect of the sigmoid colon with associated thumbprinting or spiculation. In each patient serosal inflammation of the sigmoid colon produced by an adherent segment of the ischemic small intestine was confirmed at laparotomy. In two patients, delay in surgical intervention resulted in small intestine necrosis. In a patient who has clinical signs and symptoms of colonic ischemia, diverticulitis, or small intestine obstruction but nonspecific findings on barium studies, the diagnosis of small intestine ischemia should be considered and further diagnostic imaging, such as angiography or small intestine follow-through examination, should be performed.     

The zone diet and athletic performance.

The Zone diet is the latest eating regimen marketed to improve athletic performance by opposing traditional high carbohydrate sports diets. The 40/30/30 diet is centred primarily on protein intake (1.8 to 2.2 g/kg fat free mass; i.e. total bodyweight-fat weight) and promises a change in the body's insulin to glucagon ratio through its macronutrient alterations. Changes in the existing hormonal milieu are said to result in the production of more vasoactive eicosanoids, thus allowing greater oxygen delivery to exercising muscle. This favourable condition, known as the Zone, is anecdotally reported to benefit even the most elite endurance athletes. Applying the Zone's suggested protein needs and macronutrient distributions in practice, it is clear that it is a low carbohydrate diet by both relative and absolute standards, as well as calorie deficient by any standard. Reliable and abundant peer reviewed literature is in opposition to the suggestion that such a diet can support competitive athletic endeavours, much less improve them. The notion that a 40/30/30 diet can alter the pancreatic hormone response in favour of glucagon is also unfounded. The Zone is a mixed diet and not likely to affect pancreatic hormone release in the same way individual nutrients can. Although the postprandial insulin response is reduced when comparing a 40% with a 60% carbohydrate diet, it is still a sufficient stimulus to offset the lipolytic effects of glucagon. Many of the promised benefits of the Zone are based on selective information regarding hormonal influences on eicosanoid biology. Contradictory information is conveniently left out. The principle of vasodilating muscle arterioles by altering eicosanoid production is notably correct in theory. However, what little human evidence is available does not support any significant contribution of eicosanoids to active muscle vasodilation. In fact, the key eicosanoid reportedly produced in the Zone and responsible for improved muscle oxygenation is not found in skeletal muscle. Based on the best available scientific evidence, the Zone diet should be considered more ergolytic than ergogenic to performance.     

表面处理对瓷牙材料机械强度影响的实验研究

目的 比较不同表面处理因素对瓷瓦材料机械强度的影响。方法 制备３００个表面均匀一致的实验标本,对抛光面进行表面处理,处理后的标本用万能实验机进行机械循环,然后用Ｐｉｓｔｏｎ－ｏｎ－ｔｈｒｅｅ ｂａｌｌ方法检查实验标本的挠屈强度。结果 双向卡方检验说明不同表面处理因素及不同循环次数对实验标本挠屈强度的影响都具有显著意义（（Ｐ〈０．０００１）;Ｑ－检验说明自然上釉、酸蚀、喷砂等表面自理和表面抛光相比,     

Hydration assessment using the cardiovascular response to standing

The cardiovascular response to standing (sit-to-stand change in heart rate; SSΔHR) is commonly employed as a screening tool to detect hypohydration (body water deficit). No study has systematically evaluated SSΔHR cut points using different magnitudes or different types of controlled hypohydration. The objective of this study was to determine the diagnostic accuracy of the often proposed 20?b/min SSΔHR cut point using both hypertonic and isotonic models of hypohydration. Thirteen healthy young adults (8M, 5F) underwent three bouts of controlled hypohydration. The first bout used sweating to elicit large losses of body water (mass) (>3?% sweat). The second two bouts were matched to elicit 3?% body mass losses (3?% diuretic; 3?% sweat). A euhydration control trial (EUH) was paired with each hypohydration trial for a total of six trials. Heart rate was assessed after 3-min sitting and after 1-min standing during all trials. SSΔHR was compared among trials, and receiver operator characteristic curve analysis was used to determine diagnostic accuracy of the 20?b/min SSΔHR cut point. Volunteers lost 4.5?±?1.1, 3.0?±?0.6, and 3.2?±?0.6?% body mass during >3?% sweat, 3?% diuretic, and 3?% sweat trials, respectively. SSΔHR (b/min) was 9?±?8 (EUH), 20?±?12 (>3?% sweat; P?<?0.05 vs. EUH), 17?±?7 (3?% diuretic; P?<?0.05 vs. EUH), and 13?±?11 (3?% sweat). The 20 beats/min cut point had high specificity (90?%) but low sensitivity (44?%) and overall diagnostic accuracy of 67?%. SSΔHR increased significantly in response to severe hypertonic hypohydration and moderate isotonic hypohydration, but not moderate hypertonic hypohydration. However, the 20 beats/min cut point afforded only marginal diagnostic accuracy.     

学报发展之我见

国家最新的统计数据显示,在我国5000种科技期刊中,高等院校所办的期刊已经达到1347种,其中绝大多数为学报;在我国1124种医学期刊中,学报也占有较大的比例．尽管学报的数量不少,但从期刊的综合评价体系来看,其中高质量者寥寥无几;而获得过“首届国家期刊奖,第二届国家期刊奖提名奖”的第四军医大学学报无疑是其中的佼佼者、尽管我们取得过辉煌的成绩,但依旧无法回避今日严峻的现实．要使学报能够健康地发展,我认为以下几点不容忽视．     

Model of human thermoregulation for intermittent regional cooling

INTRODUCTION: A prospective approach to save energy expenditure for a liquid cooling garment (LCG) system is to provide intermittent regional cooling (IRC) to the human body instead of continuous cooling. In order to gain insight into IRC mechanisms, a mathematical model was developed to simulate thermal interaction between the human and IRC. METHODS: Human thermoregulatory responses were simulated by a previously validated six-cylinder mathematical model. Two equations were derived from the energy balance principle to estimate LCG heat removal during ON (coolant circulation) and OFF (no coolant circulation) periods. The heat removal equations were incorporated into the boundary equations of the human model. The augmented model was used to predict human thermal responses under different IRC conditions. RESULTS AND CONCLUSIONS: The model was evaluated against experimental results with IRC in warm environments. The comparison demonstrated that the model predictions of the core temperature and mean skin temperature were reliable within root mean square deviations of +/- 0.10 degrees C and 0.44 degrees C, respectively. Simulation analysis showed that IRC has the potential to reduce power requirements. Modeling is an effective alternative to predict efficacy when actual responses cannot be attempted. A systematic approach, consisting of manikin measurements, physiological experiments, and mathematical modeling can expedite the research and development of LCG systems.     

Radiation‐induced brain disorders in patients with pituitary tumours

Radiation‐induced brain disorders (RIBD) are uncommon and they are grave sequelae of conventional radiotherapy. In the present report, we describe the clinical spectrum of RIBD in 11 patients who received post‐surgery conventional megavoltage irradiation for residual pituitary tumours. Of these 11 patients (nine men, two women), seven had been treated for non‐functioning pituitary tumours and four for somatotropinomas. At the time of irradiation the age of these patients ranged from 30 to 59 years (mean, 39.4 ± 8.3; median, 36) with a follow‐up period of 6?96 months (mean, 18.3 ± 26.4; median, 11). The dose of radiation ranged from 45 to 90 Gy (mean, 51.3 ± 13.4; median, 45), which was given in 15?30 fractions (mean, 18.6 ± 5.0; median, 15) with 2.8 ± 0.3 Gy (median, 3) per fraction. The biological effective dose calculated for late complications in these patients ranged from 78.7 to 180 Gy (mean, 99.1 ± 27.5; median, 90). The lag time between tumour irradiation and the onset of symptoms ranged from 6 to 168 months (mean, 46.3 ± 57.0; median, 57). The clinical spectrum of RIBD included new‐onset visual abnormalities in five, cerebral radionecrosis in the form of altered sensorium in four, generalized seizures in four, cognitive dysfunction in five, dementia in three and motor deficits in two patients. Magnetic resonance imaging (MRI)/CT of the brain was suggestive of radionecrosis in eight, cerebral oedema in three, cerebral atrophy in two and second neoplasia in one patient. Associated hormone deficiencies at presentation were hypogonadism in eight, hypoadrenalism in six, hypothyroidism in four and diabetes insipidus in one patient. Autopsy in two patients showed primitive neuroectodermal tumour (PNET) and brainstem radionecrosis in one, and a cystic lesion in the left frontal lobe following radionecrosis in the other. We conclude that RIBD have distinctive but varying clinical and radiological presentations. Diabetes insipidus and PNET as a second neoplastic disorder in adults following pituitary irradiation have not been reported previously.     

Acceptance of home and clinic-based cystic fibrosis carrier education and testing by first,second, and third degree relatives of cystic fibrosis patients

We contacted and offered free cystic fibrosis (CF) carrier education and testing to the first, second, and third degree relatives of individuals with CF followed at a large Southeastern US CF Clinic. Relatives were offered CF carrier education and testing either in their homes or in a genetic counseling clinic. Overall, of 514 relatives offered free CF carrier education and testing, 299 (58%) accepted. Significantly more (67%) of those offered education and testing in their homes accepted than those offered education and testing in a genetic counseling clinic (45%). Regression analyses identified several factors, including education, income, gender, perceived chance of being a carrier, and perceived chance of having a child who is a CF carrier, as predictors of acceptance of education and testing in both home and clinic sites. A smaller set of factors was identified that predicted acceptance of education and testing unique to each site. Within the limits of this study and its design, even when CF carrier testing is offered free of charge, including education and testing in the home, acceptance of education and testing, while higher than in general population samples, is not universal among at-risk relatives. Several factors which may have contributed to the observations reported in this study are discussed. Am. J. Med. Genet. 70:121–129, 1997. © 1997 Wiley-Liss, Inc.