与甲壳素缝线体外复合培养大鼠成肌细胞株L6细胞的形态学

目的：探讨甲壳素作为骨骼肌组织工程支架材料的可行性。 方法：实验于2002-06／12在南方医科大学应用解剖学研究所完成。大鼠成肌细胞株L6与甲壳素医用缝合线体外复合培养。倒置相差显微镜下观察细胞的形态和排列情况。并分别在体外复合培养的第1，2，3，4，5，6天，取出细胞支架复合体，扫描电镜观察成肌细胞的形态和排列情况。 结果：①扫描电子显微镜观察显示，甲壳素医用可吸收缝线的表面比较粗糙。②倒置相差显微镜下可见大鼠L6细胞与甲壳素制备的医用可吸收缝合线间黏附良好，细胞沿缝线排列呈现串珠样，并可以见到细胞聚集现象。③扫描电子显微镜观察，接种24h后，细胞主要为圆球形，随后细胞迁移、伸展、并见突起；第3天，成肌细胞主要为梭形，并见融合趋势；4d后，细胞沿材料纵轴排列并相互融合，并见肌小管样结构形成及细胞外基质分泌。 结论：甲壳素具有作为支架以构建组织工程化骨骼肌的潜能，支架的平行排列有助于工程化骨骼肌纤维良好方向性的形成。     

Effect of short-term erythropoietin therapy in anemic premature infants.

OBJECTIVE: To determine the effectiveness of a 10-day subcutaneous erythropoietin (rHuEpo) course of 300 units per kg per dose plus oral iron compared to oral iron alone in anemic infants during their convalescent phase of illness. STUDY DESIGN: Prospective, randomized trial performed at a 40-bed, teaching, referral, level III, neonatal intensive care unit. Infants with a gestational age at birth of less than 32 weeks, hematocrit of less than or equal to 28% with a corrected reticulocyte count of less than or equal to 5%, postconceptual age of less than 48 weeks or 5 months chronological age, and a diagnosis of anemia of prematurity were considered for inclusion. Major outcome parameters included hematocrit, corrected reticulocyte count and red cell transfusion requirements. RESULTS: A total of 60 infants were enrolled (n=30 per group). Infants randomized to rHuEpo had a significantly higher post-treatment hematocrit and corrected reticulocyte count than infants in the iron only group (p<0.001). There was a trend towards fewer red cell requirements in the rHuEpo group. CONCLUSIONS: The rHuEpo regimen studied here was associated with an acute improvement in hematocrit and corrected reticulocyte counts. This study did not demonstrate a statistically significant decrease in transfusion therapy, in part related to increased subsequent use of rHuEpo in the control group. Taken together, these data demonstrate that this regimen can effectively treat anemia in convalescent premature infants.     

Bone growth patterns in Chinese children and adolescents: a 6-year follow-up study provides evidence for sexual dimorphism and tracking

Summary We prospectively examined bone growth patterns in 894 children aged 6–17 years at the baseline visit, with a 6-year follow-up. Results show bone “tracking” over a six-year interval and sexual dimorphism of bone attained levels and timing of peak bone growth. Our findings underscore childhood and adolescence as critical periods for building bone and developing gender differences. Introduction Bone growth patterns were prospectively examined in 894 Chinese children (496 males), aged 6–17 yrs, from a population-based twin cohort. Whole-body bone area (BA), bone mineral content (BMC), and bone mineral density (BMD) were measured by DEXA at baseline and a 6-yr follow-up. Methods Graphic smoothing plots and generalized estimating equations were used to model bone attained levels, growth, and “tracking”. Results Attained levels of BMC and BA increased curvilinearly with age. Male attained levels were higher than females after age ∼15 yr, but BMD was lower between 13–17 yrs (Tanner stage I to IV). In both genders, peak BMC and BMD growth lagged ∼2 yrs behind peak BA growth, which lagged 2 yrs behind peak height growth. Peak bone growth occurred 1–3 yrs later in males. Over the 6-yr follow-up, all bone measurements “tracked”, but “shifting” across ranks also occurred, and baseline tertile ranking influenced bone growth. Females with early menarche had higher attained levels than females with late menarche at age 12–13 yrs. Conclusion Our findings confirm and expand previous studies on peak bone growth conducted in Caucasian cohorts, particularly sexually dimorphic and maturational effects. The significant “tracking” of bone measurements in this 6-yr follow-up study underscores the importance that osteoporosis prevention should begin in childhood and adolescence. Fengxiu Ouyang and Binyan Wang contributed equally to this article. Source(s) of support: This study is supported in part by grant R01 HD049059, R01 HL0864619 and R01 AR045651 from the National Institute of Health and by the Food Allergy Project.     

Travel distance, age, and sex as factors in follow-up visit compliance in the post-gastric bypass population

BACKGROUND: There is no consensus regarding the optimal rate of follow-up in the post-bariatric surgery patient population. METHODS: The records of all patients who underwent laparoscopic Roux-en-Y gastric bypass from 2001 to 2003 were reviewed. Using patient zip codes, travel distances were calculated between the patients' places of residence and our clinic. Patients were then assigned to 1 of 3 cohorts according to the following distances: (1) < 50 miles, (2) 50 to 100 miles, and (3) > 100 miles. Patient compliance with follow-up appointments at 3 weeks, 3 months, 6 months, 9 months, and 12 months was analyzed. Linear trends were identified using the Mantel-Haenszel test. Age and sex were analyzed as possible predictors of compliance using the chi(2) test. P values < .05 were considered statistically significant. RESULTS: The study group comprised 150 patients (127 females and 23 males). The 3 cohorts contained 115, 21, and 14 patients, respectively. All patients in each cohort were compliant with the 3-week follow-up appointment. Although there were differences in compliance between cohorts at each of the remaining appointments, only the 9-month (70.3% vs 61.9% vs 35.7%) visit showed statistical significance (P = .035). The 6-month visit trended toward significance (85.2% vs 76.2% vs 64.3%; P = .088). Males were more likely to be compliant with the 12-month follow-up (P = .040). When controlling for sex, travel distance was also a predictor of compliance at this follow-up visit (P = .024). Age was not predictive of compliance (P = .827). CONCLUSION: Based on our findings, we conclude that travel distance from the clinic does not significantly affect compliance at the initial follow-up, 3-month, and 12-month appointments. However, distance does tend to affect compliance at the 6-month appointment and significantly affects compliance at the 9-month appointment. Males are more likely to be compliant at the 12 month follow-up visit. We must continue to strive for 100% follow-up in our post-bariatric surgery patients.     

Contribution of Gender to Pathophysiology and Clinical Presentation of IBS: Should Management Be Different in Women?

The irritable bowel syndrome (IBS) is found more commonly in women than men. It is more prevalent in patients with chronic fatigue syndrome, fibromyalgia, and chronic pelvic pain, all syndromes characterized by pain and found predominantly in women. This article reviews evidence for a role of biological sex factors and gender on the pathways mediating visceral pain. The effect of gonadal hormones on gastrointestinal motility and the sensory afferent pathway and central processing of visceral stimuli and the contribution of gender role to the clinical presentation are discussed. Although differences in responses to treatment modalities between genders exist, the approach to IBS patients in both genders is quite similar. Nevertheless, a special attention to gender role and stress-related factors should be addressed. New developments in research, outlined in the paper, might bring more gender-specific treatments in the future.     

P1 blood group antigen expression and epidemic hemolytic uremic syndrome

P1 blood group positivity has been postulated as a host factor which may provide protection against the development of post-enteropathic hemolytic uremic syndrome (HUS). In this study, blood group status in 20 Inuit survivors ofEscherichia coli 0157: H7-associated HUS was compared with age-and sex-matched controls from the same community who had experienced uncomplicated diarrheal illness due to the same pathogen. Of 20 HUS survivors, 6 were P1 antigen positive compared with 8 of the 20 controls (P=0.7). We conclude that P1 antigen positivity was not protective against HUS in this population. Further studies of this condition to clarify the role of host factors in verotoxin-induced endothelial damage are indicated.     

Influences on Food Selection of Women on High- and Low-Fat Diets

There is evidence that long-term maintenance of a low-fat diet reduces preference for high-fat foods. Sensory evaluation of the taste of fat, and preference for high and low-fat foods were studied in a group of former participants in a randomized dietary intervention trial aimed at lowering fat consumption. Intervention subjects consuming less than 25% of daily calories as fat and control subjects consuming more than 35% of daily calories as fat agreed to be in a "taste perception" study. In Study 1, subjects tasted 20 dairy solutions containing different levels of fat and sugar. Subjects rated the perceived intensity of fat taste, and of liking, for each of the solutions. In Study 2, subjects were asked to taste and rate 4 high-fat and 4 low-fat snack foods, and were then allowed to freely consume these foods in a preference test. Intervention and control subjects were similar in their sensory evaluation of the taste of fat in Study 1. In Study 2, intervention subjects reported a reduced hedonic rating of the taste of high-fat snack foods compared to control subjects, yet intervention subjects consumed the same amount of high-fat snack foods as control subjects. We conclude that a successful outcome in a dietary intervention may be due to social and cognitive factors, in addition to potential changes in hedonic response to fat.