脂多糖诱导体外培养骨骼肌卫星细胞表达肝细胞生长因子的变化

目的:研究证实,在众多生长因子中,肝细胞生长因子无论在体外还是体内都可以激活静止状态的肌卫星细胞,修复受损肌肉。采用脂多糖刺激体外培养的骨骼肌卫星细胞,观察肌卫星细胞产生肝细胞生长因子以及肌卫星细胞增殖分化的变化。方法:实验于2006-07/2007-05在华中科技大学同济医学院同济医院创伤外科实验室完成。①实验材料:健康SD成年雄性大鼠,体质量150～200g,由华中科技大学同济医学院实验动物中心提供。实验过程中对动物处置符合实验动物伦理学标准。②实验方法:分离SD大鼠后肢部分股四头肌肉进行骨骼肌卫星细胞的培养。取第2代细胞爬片,待细胞增殖到80%密度时,丙酮固定细胞,常规处理后进行α-sarcometricactin细胞免疫化学染色鉴定,以成纤维细胞作为阴性对照。取第3代骨骼肌卫星细胞,应用0,5,10,20mg/L脂多糖刺激体外培养的大鼠骨骼肌卫星细胞,采用ELISA方法测细胞培养液中的肝细胞生长因子的浓度。取第4代骨骼肌卫星细胞,用含体积分数为0.10胎牛血清的培养基配制成单个细胞悬液,调整浓度为5×107L-1,分成两组,一组加入10mg/L脂多糖,另一组不加任何干预。采用噻唑蓝(MTT)法测定卫星细胞的增殖率。结果:①以未经脂多糖处理的无血清培养基培养的肌肉卫星细胞培养液为对照,将对照组和5,10,20mg/L脂多糖处理组比较,各实验组肝细胞生长因子浓度明显高于对照组(P<0.05)。②5,10,20mg/L脂多糖刺激骨骼肌卫星细胞分泌的肝细胞生长因子水平差异无显著性。③肝细胞生长因子在脂多糖刺激后36h分泌浓度最高。④脂多糖刺激肌卫星细胞的增殖分化明显高于未经刺激的肌卫星细胞。结论:①脂多糖可诱导骨骼肌卫星细胞自分泌肝细胞生长因子。②不同质量浓度脂多糖培养基中肝细胞生长因子水平差异无统计学意义。③脂多糖具有促进骨骼肌卫星细胞增殖分化的效应。     

Disease surveillance in recombining pathogens: multilocus genotypes identify sources of human Coccidioides infections

Molecular surveillance of pathogenic microbes works by genotyping isolates with DNA fingerprinting techniques and then using these genotypes to assign individuals to populations. Clonality is assumed in many fingerprinting studies, although this assumption has been shown to be false for many organisms. To accommodate recombining organisms into surveillance programs, methods using population allele frequencies in combination with individual multilocus genotypes are necessary. Here, we develop a statistical method appropriate for haploid recombining microbes that allows individuals to be assigned to populations. We illustrate the usefulness of this technique by inferring the source populations for Coccidioides isolates recovered from patients treated outside the endemic area of Coccidioides sp., the etiological agents of human coccidioidomycosis, but with a travel history including visits to one or more endemic areas.     

A Novel Obturator Device for Management of Dilated Trachea-esophageal Puncture Tract Fistulas

Voice rehabilitation in laryngectomized patients by tracheoesophageal puncture is a time tested technique. In some patients the tracheoesophageal puncture gets inordinately dilated leading to leakage around the prosthesis. Most of these fistulas are managed by a variety of conservative treatments like temporary removal of prosthesis, placement of silastic ring over the prosthesis, placement of nasogastric tube and airway protection by a cuffed tracheostomy tube. Intractable fistulas are tackled by surgical closure but are fraught with failures. We hereby suggest a novel temporary obturator that can be can be easily made at a very low cost in any hospital having prosthetic rehabilitation services and obviates the need for a tracheostomy tube, nasogastric tube and repeated hospital visits.     

Acute pyelonephritis with renal abscesses and acute renal failure after salmonella infection

Urinary tract infections, renal abscess formation and acute renal failure (ARF) after salmonella infection are rarely reported in children. We present a previously healthy teenager who developed ARF with renal abscess formation after salmonella infection, in whom we believe that acute salmonella pyelonephritis was the main causative factor for ARF and not dehydration, shock or rhabdomyolysis, which have already been described in the literature. With prolonged antibiotic treatment and adequate hydration, the boy’s condition improved, but chronic kidney disease was unfortunately inevitable. Conclusion: Salmonella pyelonephritis has, according to our knowledge, not yet been described to be the main causative factor of ARF in previously healthy children, as was the case in our patient. Long‐term antibiotic treatment of at least 6 weeks is probably a must in such patients, even though chronic kidney disease could not have been prevented.     

Analysis of blood-culture isolates from neonates of a rural hospital

All blood culture reports obtained from newborns admitted in a neonatal care unit during 1983-87 were reviewed to determine the current bacteriological profile of neonatal septicemia. A total of 1160 neonates of high risk category or having clinical features suggestive of septicemia were subjected to blood culture study during this period. The culture positivity rate was 73%. Of these, 24.9% cultures were polymicrobial. Among the 1059, growths obtained, 60.1% were Gram negative, with Klebsiella, E. coli and Pseudomonas as the commonest pathogens. In Gram positive group, coagulase negative Staphylococci were most frequent, constituting 24% of the total isolates. An increasing incidence of coagulase positive Staphylococci and Pseudomonas infections was observed in recent years. Another significant finding was a comparatively high prevalence of Group D beta hemolytic isolates among streptococcal growths, with S. fecalis as the single commonest streptococci isolate.     

Acute laryngeal stridor — Controversies in current management

Conclusion The successful management of acute laryngeal stridor in infants and small children depends upon a close cooperation and team work of pediatrician, otolaryngologist and specialised nursing care in a pediatric intensive care unit. The overall opinion is in favour of steroid, racemic epinephrine and intubation or tracheostomy in severe croup. Endoscopy should be performed in all the cases, either immediately, prior to or con-commitant with the establishment of airways. This helps in achieving correct diagnosis and rationalising the treatment. Mortality and morbidity has been significantly reduced by close monitoring and quality nursing of intubated or tracheostomised child. Early extubation can be achieved by regular examination of laryngeal mucosa by direct laryngoscopy in an intensive care unit. Cases of severe croup should be followed up, as they have increased susceptibility to develop bronchial asthma.