RENAL FUNCTION IN CHRONICALLY CATHETERIZED CONSCIOUS DIABETIC RATS USING CONSTANT AND SERVO-CONTROLLED INFUSION

1. Infusion experiments were performed on chronically catheterized conscious rats to assess kidney function before and after the induction of diabetes mellitus with streptozotocin. 2. Two infusion regimens were used, a conventional constant-infusion protocol and a novel computer-driven, servo-controlled fluid replacement technique. The latter enables body fluid status to be maintained throughout a study occasion by servo-controlled replacement of spontaneous urinary fluid losses. 3. The chronically catheterized conscious rat infused using a servo-controlled system appears to be the optimum model for a study of diabetic renal function. The conscious preparation circumvents problems associated with anaesthesia and acute surgery. The servo-controlled infusion protocol maintains the altered fluid status of the diabetic condition. Both hyperfiltration and polyuria, characteristics of human diabetes often absent in anaesthetized and/or constantly infused diabetic rats, were seen in all conscious servo-controlled diabetic animals. 4. The new regimen enables a more accurate assessment of renal function in experimental diabetes than with previous protocols. It should prove useful in future studies, particularly those assessing the role of anti-diabetic drugs on the kidney.     

Unexplained diarrhoea and failure to thrive in 2 siblings with unusual facies and abnormal scalp hair shafts: a new syndrome

A family is described in which 2 siblings born to healthy parents presented with abnormal facies, persistent diarrhoea, and early death. Exhaustive pathological and biochemical investigations failed to find a cause. The scalp hair of both babies had an abnormal amino-acid composition, and presented an appearance that was unique on scanning electron microscopical examination; this fact and the clinical picture probably represents a new syndrome.     

Modulation of implantation-associated integrin expression but not uteroglobin by steroid hormones in an endometrial cell line

In order to test the hypothesis that integrin and uteroglobin (UG) expression in cultured endometrial cells are affected by hormone treatment, Ishikawa-CH endometrial cancer cells were cultured and exposed to oestradiol or oestradiol and progesterone regimens and assayed using immunohistochemistry. We evaluated the intensity of immunohistochemical staining for the integrin monomers alpha(v) and beta1, the dimers alpha(v)beta3 and alpha(v)beta6, and for the secretory protein uteroglobin under various experimental conditions. Cells grown in control media stained positively for the integrin monomers alpha(v) and beta1, the dimer alpha(v)beta3, and for UG. Oestradiol and sequential oestradiol/progesterone reversibly suppressed staining for the dimer alpha(v)beta3. Hormone treatment had no effect on the staining of the beta1 and alpha(v) monomers or UG. The alpha(v)beta6 dimer antibody did not stain under any experimental treatment conditions. These data indicate that expression of the integrin complex alpha(v)beta3 is reversibly suppressed by oestradiol in Ishikawa cells and that these cells may be a good model for studying hormone-driven molecular changes in endometrium.      

尿中睾酮与表睾酮的三甲基硅烷化及其比值的GC—MS测定

对睾酮及表睾酮的三甲基硅烷化进行了详细考察,找到了较好的抗氧剂巯基乙醇,确定了较好的衍生化条件,衍生化产物单一。并采用GC—MS法测定了尿中睾酮与表睾酮的比值。实验条件为:以氦为载气,SE—54熔融石英柔性毛细管柱、程序升温进行样品分离,多离子检测(MID),监测m/z432的离子。该法专属、灵敏、快速。睾酮与表睾酮比值在1:1～10:1(睾酮为20ng/μl)与相应峰面积比呈线性关系(r=0.998),最低检测限为1ng,最低检测尿药浓度为8ng/ml。     

Heterogeneity of B cell involvement in acute nonlymphocytic leukemia

In order to study the pattern of B cell involvement in acute nonlymphocytic leukemia (ANLL), multiple B lymphoid cell lines were established by Epstein-Barr virus transformation of peripheral blood mononuclear cells from two patients with the disease who were heterozygous for the X chromosome-linked glucose-6-phosphate dehydrogenase (G6PD). In one patient, the progenitor cells involved by the leukemia exhibited multipotent differentiative expression, whereas in the other patient the cells showed differentiative expression restricted to the granulocytic pathway. In the patient whose abnormal clone showed multipotent expression, the ratio of B-A G6PD in B lymphoid cell lines was skewed in the direction of type B (the enzyme characteristic of the leukemia clone) and significantly different from the 1:1 ratio expected. It is, therefore, likely that the neoplastic event occurred in a stem cell common to the lymphoid series as well as to the myeloid series. In contrast, evidence for B cell involvement was not detected in the patient whose ANLL progenitor cells exhibited restricted differentiative expression. These findings underscore the heterogeneity of ANLL. Clinically and morphologically similar malignancies in these two patients originated in progenitors with different patterns of stem cell differentiative expression. This difference may reflect differences in cause and pathogenesis.     

Mutation spectrum and genotype-phenotype analyses in Cowden disease and Bannayan-Zonana syndrome, two hamartoma syndromes with germline PTEN mutation

The tumour suppressor gene PTEN , which maps to 10q23.3 and encodes a 403 amino acid dual specificity phosphatase (protein tyrosine phosphatase; PTPase), was shown recently to play a broad role in human malignancy. Somatic PTEN deletions and mutations were observed in sporadic breast, brain, prostate and kidney cancer cell lines and in several primary tumours such as endometrial carcinomas, malignant melanoma and thyroid tumours. In addition, PTEN was identified as the susceptibility gene for two hamartoma syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or Ruvalcaba-Riley-Smith syndrome (MIM 153480). Constitutive DNA from 37 CD families and seven BZS families was screened for germline PTEN mutations. PTEN mutations were identified in 30 of 37 (81%) CD families, including missense and nonsense point mutations, deletions, insertions, a deletion/insertion and splice site mutations. These mutations were scattered over the entire length of PTEN , with the exception of the first, fourth and last exons. A 'hot spot' for PTEN mutation in CD was identified in exon 5 that contains the PTPase core motif, with 13 of 30 (43%) CD mutations identified in this exon. Seven of 30 (23%) were within the core motif, the majority (five of seven) of which were missense mutations, possibly pointing to the functional significance of this region. Germline PTEN mutations were identified in four of seven (57%) BZS families studied. Interestingly, none of these mutations was observed in the PTPase core motif. It is also worthy of note that a single nonsense point mutation, R233X, was observed in the germline DNA from two unrelated CD families and one BZS family. Genotype-phenotype studies were not performed on this small group of BZS families. However, genotype-phenotype analysis inthe group of CD families revealed two possible associations worthy of follow-up in independent analyses. The first was an association noted in the group of CD families with breast disease. A correlation was observed between the presence/absence of a PTEN mutation and the type of breast involvement (unaffected versus benign versus malignant). Specifically and more directly, an association was also observed between the presence of a PTEN mutation and malignant breast disease. Secondly, there appeared to be an interdependent association between mutations upstream and within the PTPase core motif, the core motif containing the majority of missense mutations, and the involvement of all major organ systems (central nervous system, thyroid, breast, skin and gastrointestinal tract). However, these observations would need to be confirmed by studying a larger number of CD families.      

Cochlear implantation in common forms of genetic deafness

Genetic factors are among the main etiologies of severe to profound hearing loss and may play an important role in cochlear implantation (CI) outcomes. While genes for common forms of deafness have been cloned, efforts to correlate the functional outcome of CIs with a genetic form of deafness carried by the patient have been largely anecdotal to date. It has been suggested that the differences in auditory performance may be explained by differences in the number of surviving spiral ganglion cells, etiology of hearing loss, and other factors. Knowledge of the specific loci and mutations involved in patients who receive cochlear implants may elucidate other factors related to CI performance. In this review article, current knowledge of cochlear implants for hereditary hearing loss will be discussed with an emphasis on relevant clinical genotype-phenotype correlations.     

薄层扫描法测定黄芪生脉颗粒中黄芪甲甙含量

目的：制订黄芪生脉颗粒中黄芪甲甙含量测定方法。方法：双波长薄层扫描法，经乙酰洗涤、正丁醇提取和Ｄ１０１大乳吸附树脂柱层析法制备样品，以氯仿－甲醇－水（１３：７：２）下层液为展开剂，检测波长为５１０ｎｍ，参比波长为７００ｎｍ。结果：加标回收率平均为９８．７％（ＲＳＤ＝２．０％，ｎ＝６），标准曲线ｒ＝０．９９６６，重复性ＲＳＤ＝１．４％（ｎ＝５），精密度ＲＳＤ＝２．０％（ｎ＝６）。结论：方法稳定、可靠