特定培养基条件下大鼠脂肪间充质干细胞体外定向软骨细胞的分化

目的:体外诱导大鼠脂肪间充质干细胞向软骨细胞分化,并对分化细胞进行相应鉴定,观察脂肪间充质干细胞作为软骨组织工程种子细胞的可行性。方法:实验于2005-05/2006-05在湘雅医院中心实验室完成。①取大鼠腹股沟脂肪,消化分离脂肪间充质干细胞进行原代培养。②流式细胞仪检测第3代脂肪间充质干细胞表面CD29,CD34,CD44表达。③传3代细胞进行微团培养1d,换用含体积分数为0.01的新生牛血清、10μg/L的转化生长因子β1、6.25mg/L的胰岛素、6.25mg/L的转铁蛋白、1×10-7mol/L的地塞米松、50mg/L的维生素C的高糖DMEM诱导液,为特定培养条件。④在诱导后4,7,14d应用阿尔新兰染色、蕃红O/固绿染色和Ⅱ型胶原免疫细胞化学评价软骨形成情况。⑤反转录-聚合酶链反应在诱导后0和14d检测脂肪间充质干细胞前Ⅱ型胶原蛋白和聚集蛋白聚糖mRNA的表达。结果:①脂肪间充质干细胞的形态特征:原代脂肪间充质干细胞呈短梭形、梭形及多角形,3代后呈均一长梭形。②脂肪间充质干细胞的表面标志鉴定:脂肪间充质干细胞表达CD29,CD44,基本不表达CD34。③脂肪间充质干细胞诱导后的形态特征:脂肪间充质干细胞经诱导后,由长梭形转变为三角形、多角形或短梭形,逐渐聚集成结节。④脂肪间充质干细胞诱导后的细胞化学染色结果:诱导后脂肪间充质干细胞胞外基质阿尔新兰染色、蕃红O/固绿染色、和Ⅱ型胶原免疫细胞化学着色阳性。⑤反转录-聚合酶链反应检测结果:反转录-聚合酶链反应检测未诱导脂肪间充质干细胞不表达前Ⅱ型胶原蛋白和聚集蛋白聚糖mRNA基因,而诱导后的脂肪间充质干细胞表达前Ⅱ型胶原蛋白和聚集蛋白聚糖mRNA基因。结论:脂肪间充质干细胞在由转化生长因子1、胰岛素、转铁蛋白等组成的特定培养基条件诱导下可以定向软骨细胞分化。     

The Feasibility of Longitudinal Patient Contacts in a Large Medical School

Problem: Longitudinal patient contacts are being implemented worldwide as a way to enhance a patient-centered orientation among medical students. In large medical schools, longitudinal integrated clerkships may not be feasible, so other ways must be sought to expose students to prolonged contact with patients. Intervention: Medical students were attached to a family practice and assigned a panel of 4 patients to follow over the 3 years of their clinical training. Their role was that of companion on the patient’s medical journey. The program consisted of several encounters, joining the patient in the medical setting for significant events, and written assignments. This intervention was piloted with 35 students. We describe our experiences from the 1st pilot year of this program. Context: The intervention was performed with 3rd-year students—of a 6-year curriculum—at a large medical school in the Netherlands. Outcome: Finding enough patients per practice was feasible. On the whole, students fulfilled the program’s expectations regarding frequency of patient encounters and assignments. The most frequent problems encountered by the students were uncertainty about their role and setting boundaries in their contact with the patients. They needed more preceptor supervision and coaching than they received. Lessons Learned: For junior students, close and structured supervision led by the faculty is necessary to help them navigate and learn from a panel of patients. Students need guidance about what role they should take on and on how to manage both their own and their patient’s expectations. Guided reflection is necessary to help students give meaning to their experiences with patients.     

Comparative study of patients with chronic hepatitis C virus infection due to genotypes 1 and 3 referred for treatment in southeast Brazil

Background

The progression of liver disease in patients with chronic hepatitis C virus (HCV) infection is influenced by host and viral factors. Distinct clinical outcomes in patients infected with different HCV genotypes have been described in the literatute. However, the association between specific HCV genotype and clinical outcome remains unclear. We set out to study the natural history of HCV genotype 1 and 3 infections in Campinas, São Paulo state, Brazil, focusing on epidemiological, clinical, biochemical, and histological characteristics.

Methods

Patients with HCV infection referred for treatment between January 2003 and December 2006 were included in this study. We collected epidemiological, clinical, and laboratorial data using standard forms.

Results

A total of 283 patients were included; genotype 1 was idenfied in 163 (57.6%) patients, genotype 3 in 112 (39.6%), genotype 2 in 7 (2.5%), and genotype 4 in 1 (0.35%). Patients with genotype 2 and 4 were excluded from analysis. Multivariate analysis showed that intravenous energetic drug, positive cryoglobulin, and cirrhosis were independently and significantly associated with HCV genotype 3 (p < 0.05).

Conclusion

Genotype 3 currently seems to be associated with intravenous energetic drug, high frequency of cryoglobulinemia, and advanced liver disease in our region. Understanding the distribution of the different HCV genotypes can elucidate transmission of HCV and support optimal prevention strategies.

     

Etiology and predictors of urinary incontinence and its effect on quality of life

Aim: Urinary incontinence associated with dementia can result in medical comorbidities. We aimed to determine the prevalence of urinary incontinence and to identify the etiology and factors associated with urinary incontinence in dementia patients. Methods: Patients with an Mini‐Mental State Examination (MMSE) score of more than 10, attending the memory clinic were recruited. Basic demographic data, types and duration of dementia, use of cholinesterase inhibitor and other drugs with anticholinergic effects, carer stress and presence of urinary incontinence in the previous 6 months were recorded. Urodynamic studies were carried out in those patients with urinary incontinence. Results: One hundred and forty‐four subjects with a mean age of 78 years (standard deviation 6.8) were included. Forty‐eight (33.3%) had urinary incontinence. There was no statistically significant difference between continent and incontinent groups regarding age, MMSE, duration of dementia, use of cholinesterase inhibitor and of drugs with anticholinergic effects. Presence of nocturia of more than twice per night (odds ratio [OR] 4, 95% confidence interval [CI] 1.7, 9.2), use of walking aids (OR 2.6, 95% CI 1.1, 5.9) and male sex (OR 1.36, 95% CI 1.1, 5.2) were independent predictors of urinary incontinence. Urodynamic studies showed that 21 subjects had detrusor overactivity, 13 had bladder outlet obstruction, two with low compliance bladder, two with small bladder capacity, four with detrusor hyperactivity and impaired contractility. Conclusion: Urinary incontinence commonly occurs in dementia subjects. Poor mobility and presence of nocturia increase the risk of urinary incontinence. Correction of the possible reversible factors may help to reduce the prevalence of urinary incontinence in patients with dementia and reduce carer stress.     

Subpopulations of fetal-like gingival fibroblasts: characterisation and potential significance for wound healing and the progression of periodontal disease

Wound healing in the adult is commonly compromised by excessive scar formation. In contrast, fetal wound healing is a regenerative process characterised by the conspicuous absence of scarring. Available evidence suggests that phenotypic differences between fetal and adult fibroblasts are important determinants of these distinct modes of tissue repair. In this context, a number of groups (including our own) have documented differences between fetal and adult fibroblasts with respect to such potentially relevant characteristics as migratory activity, motogenic response to cytokines and the synthesis of motility factors, cytokines and matrix macromolecules. The oral mucosa appears to be a privileged site in the adult in that it continues to display a fetal-like mode of wound healing. Data are presented in this review indicating that a subpopulation of gingival fibroblasts expresses several 'fetal-like' phenotypic characteristics. These observations are discussed in terms of both the continued expression of a fetal-like mode of wound healing in the oral mucosa and the possible differential involvement of distinct fibroblast subpopulations in the progression of periodontal disease.