Optimal level of 25‐(OH)D in children in Nanjing (32°N Lat) during winter

Background: The optimal serum level of 25‐hydroxyvitamin D (25‐(OH)D) for bone health is still unclear, especially in children. Hypovitaminosis D is also re‐emerging in developed and developing countries. The purpose of the present study was therefore to determine optimal serum 25‐(OH)D level and preliminarily identify the vitamin D nutritional status in Nanjing children. Methods: All subjects (76 healthy, 66 suffering from infectious diseases) aged 0–10 years were recruited during the period December 2007–March 2008. Venous blood samples were collected before breakfast and the levels of serum 25‐(OH)D, parathyroid hormone (PTH), bone‐specific alkaline phosphatase (BAP), calcium (Ca), phosphorus (P) were determined. The optimal level of serum 25‐(OH)D was explored using the three response curves of 25‐(OH)D versus PTH, 25‐(OH)D versus BAP, and 25‐(OH)D versus Ca×P product. Results: For 25‐(OH)D ≤ 50 nmol/L, PTH and BAP were both inversely correlated with 25‐(OH)D (PTH, r=?0.864, P < 0.01; BAP, r=?0.856, P < 0.01). For 25‐(OH)D > 50–60 nmol/L, levels of PTH and BAP remained steady. With regard to the Ca×P product, for 25‐(OH)D ≤ 50 nmol/L, Ca×P product increased as 25‐(OH)D increased (r= 0.037, P > 0.05). For 25‐(OH)D > 50–60 nmol/L, Ca×P product remained steady. The mean serum level of 25‐(OH)D was 80.5 ± 29.3 nmol/L (mean ± SD) in the healthy children, and 65.7 ± 32.3 nmol/L in the sick children. Conclusion: The optimal 25‐(OH)D level may be 50–60 nmol/L for bone health in Nanjing children. The vitamin D nutritional status of Nanjing children is relatively good in winter.     

Bed‐sharing among six‐month‐old infants in western Sweden

Aim: In spite of several reports of an increased risk of sudden infant death syndrome (SIDS) in connection with bed‐sharing, it is not an uncommon practice. The aim of this study was to examine bed‐sharing at 6 months of age and the factors that are associated with bed‐sharing. Methods: Our cohort comprised 8176 randomly chosen families. At 6 month of age, the families received an invitation to the study, with a questionnaire, which was completed by 5605 families (response rate 68.5%). Results: Of the families, 19.8% bed‐shared. In the multivariate analysis, we found a correlation between breast‐feeding and bed‐sharing (breast‐feeding at 6 months: OR 1.94; 95% CI 1.56, 2.41). Moreover, we found an association with 3+ nightly awakenings at 6 months (2.70; 2.20, 3.32). It was more common to share a bed if the parent was single (2.04; 1.19, 3.51) and less common if the infant was bottle‐fed in the first week (0.70; 0.54, 0.90). Never using a pacifier was associated with a higher frequency of bed‐sharing. Conclusion: We found a correlation between breast‐feeding and bed‐sharing as well as between sleeping problems and a single parent. A lower percentage of infants sleeping in the parental bed were seen in association with formula feeding in the first week after birth.     

A family-based association study of PLP1 and schizophrenia

Recently, proteolipid protein 1 (PLP1) has been identified as downregulated in schizophrenia by quantitative PCR and other technologies. In this work we attempted to investigate the role of PLP1 in the etiology of schizophrenia using a family based association study in 487 Chinese Han family trios. The TDT for allelic association demonstrated that, in male, a weak association was detected in SNP rs475827 with p=0.0294, suggesting that the genetic polymorphisms within PLP1 in male are likely to confer an increased susceptibility to schizophrenia in the Chinese population.     

Small intestinal organoid-derived SP cells contribute to repair of irradiation-induced skin injury

Side population (SP) cells, characterized by their ability to efflux the fluorescent dye Hoechst 33342, were isolated from the small intestine of mice. In the abdominal irradiation model, small intestinal organoid-derived SP (sioSP) cells from ROSA 26 mice were submucosally injected into the small intestinal of the irradiated C57BL/6 mice. In contrast to the control mice, mice receiving sioSP cell transplantation demonstrated far less skin injury. Most importantly, hairs in the irradiated body part of the transplanted mice almost remained black, whereas the counterpart in the control mice almost turned white. Histochemistry studies showed the donor cells gave rise to skin cells in the irradiated skin. Thus, our study demonstrated for the first time that stem cells from the small intestine can differentiate into skin cells under local cues and thus supports the theory of stem cell plasticity.     

Adhesion strength of human tenocytes to extracellular matrix component-modified poly(DL-lactide-co-glycolide) substrates

We report a direct measurement of the adhesion strength of human embryonic tenocytes (HETCs) and transformed human embryonic tenocytes (THETCs) to fibronectin (FN)- and type I collagen (CNI)- modified poly(DL-lactide-co-glycolide) (PLGA) substrates with a micropipette aspiration technique. PLGA substrates were first coated with poly-D-lysine (PDL), and then with various concentrations (1 microg/ml, 2 microg/ml, 5 microg/ml, and 10 microg/ml) of FN and CNI in serum-free F12 media. Anti-FN and Anti-CNI antibodies were used to inhibit attachment of tenocytes to FN- and CNI- modified substrates in a dilution range of 1:5000-1:500 and 1:1500-1:250, respectively. The substrates were employed for incubation of HETCs and THETCs for 30 min at 37 degrees C before the adhesion strength measurements. We found that the adhesion strengths showed a strong dependence on the seeding time and FN or CNI concentrations. Anti-FN and Anti-CNI antibodies significantly compromised adhesion of HETCs and THETCs to the corresponding modified substrates (P < 0.05). These findings show that FN- or CNI-modified polymer substrates offer significant advantages for tissue engineering tendon scaffolds concerning tenocyte adhesion. In addition, HETCs and THETCs bear similar biological behaviors in terms of adhesion, indicating the possibility of using THETCs in place of HETCs in tissue engineering construction of human tendons.     

An animal model of SARS produced by infection of Macaca mulatta with SARS coronavirus

A new SARS animal model was established by inoculating SARS coronavirus (SARS-CoV) into rhesus macaques (Macaca mulatta) through the nasal cavity. Pathological pulmonary changes were successively detected on days 5-60 after virus inoculation. All eight animals showed a transient fever 2-3 days after inoculation. Immunological, molecular biological, and pathological studies support the establishment of this SARS animal model. Firstly, SARS-CoV-specific IgGs were detected in the sera of macaques from 11 to 60 days after inoculation. Secondly, SARS-CoV RNA could be detected in pharyngeal swab samples using nested RT-PCR in all infected animals from 5 days after virus inoculation. Finally, histopathological changes of interstitial pneumonia were found in the lungs during the 60 days after viral inoculation: these changes were less marked at later time points, indicating that an active healing process together with resolution of an acute inflammatory response was taking place in these animals. This animal model should provide insight into the mechanisms of SARS-CoV-related pulmonary disease and greatly facilitate the development of vaccines and therapeutics against SARS.     

Human papillomavirus infection and P53 codon 72 genotypes in a Hispanic population at high-risk for cervical cancer

Cervical cancer mortality is high in Texas, especially among Hispanic women living in south Texas and adjacent Mexico. Though human papillomavirus (HPV) infection has a causal role in the development of cervical cancer, there are no published data on the prevalence of HPV genotypes in this underscreened region. We studied 398 Hispanic women on both sides of the border along the lower Rio Grande River to determine the prevalence of HPV genotypes and risk factors for cervical cancer. Using a nested PCR system HPV was detected in 62% of cervical specimens, including all the known high-risk HPV genotypes, with HPV16 and HPV18 the most frequent (30.6% and 23.0%, respectively). Multiple infections were common (29.4% of the infected specimens), and where this occurred we were more likely to find high-risk HPV genotypes. We examined host p53 codon 72 genotype frequencies and found that patients with cervical abnormalities and women with HPV16 and HPV18 infections had a lower genotype frequency of the homozygous (AA) previously reported to be associated with cervical cancer, than uninfected women with no abnormalities. In this US/Mexico border population high rates of potentially oncogenic HPV viruses and multiple infections are consistent with observed elevated cervical cancer rates. These data are further evidence that in this underserved population HPV infections are associated with high rates of malignancy, but that host p53 genotypic variations are unlikely to be primary factors in oncogenesis.     

2000年～2004年淋球菌深圳分离株的耐药性变迁

目的了解深圳地区淋球菌流行状况和耐药趋势,为淋病的预防和治疗提供依据.方法琼脂稀释法测定青霉素、四环素、壮观霉素、头孢三嗪和环丙沙星对246株淋球菌的最低抑茵浓度,头孢硝噻吩纸片法检测β-内酰胺酶.结果淋球茵PPNG和TRNG阳性率呈逐年上升趋势;淋球菌对5种常规抗生素的耐药性均有不同程度增强,尤以环丙沙星耐药性增强突出.结论深圳地区淋球菌耐药状况较为严重,大观霉素可作为淋病治疗的首选药物.临床应加强淋球茵耐药性监测并根据药物敏感试验合理使用抗生素.     

神经病学临床见习教学的思考

本文从多方面介绍了神经病学临床见习的教学方法,认为临床见习的重点是理论联系实际及学生临床思维能力的培养,促进医学生向医生的转变。     

大学生强迫症状问卷的编制及信效度分析

目的：对自编的大学新生强迫症状调查问卷进行心理测量学分析。方法：699名大学新生接受测验，使用SPSSl0．0for windows 2000和Amos4．0软件对所得数据进行分析处理。结果：大学新生强迫症状调查问卷有较好的内在信度和结构效度，总量表的克隆巴赫α系数为0．8541，验证性因素分析表明测量数据与量表结构拟合良好。结论：大学新生强迫症状调查问卷具有较好的心理测量学指标，各种强迫症状的维度是性强迫观念，完美化强迫信念，一般强迫思维。强迫行为习惯。