Breakdown of gastric mucus in presence of Helicobacter pylori.

The potential of Helicobacter pylori to degrade gastric mucus was examined. Colonies of H pylori cultured from antral mucosal biopsy specimens of patients with non-autoimmune gastritis were washed with sterile saline, passed through a sterilisation filter, and the filtrate examined for urease, protease, and mucolytic activity. The filtrate failed to hydrolyse bovine serum albumin, or to degrade stable mucus glycoprotein structures of high particle weight that had been separated from human gastric mucus on Sepharose 2B. The high particle weight mucus glycoprotein was, however, extensively degraded when incubated with H pylori filtrate (which possessed urease activity) in the presence of 2 M urea, to release fragments of Mr approximately 2 X 10(6). The high particle weight mucus glycoprotein was also broken down to a comparable extent when incubated with Jack bean urease in the presence of 2 M urea, or 1 M ammonium carbonate, or 40 mM carbonate-bicarbonate buffer (pH 8.7), but not when treated with 4 M urea alone, or Jack bean urease alone. These results indicate that the loss of high particle weight mucus glycoprotein in gastric mucus from patients with gastritis and gastric ulcers is unlikely to be due to the mucolytic action of an extra-cellular protease produced by H pylori, but it may result from the destabilising effects of a carbonate-bicarbonate buffer, generated at the mucosal surface when H pylori urease hydrolyses transuded plasma urea.     

Effect of dietary protein on Masheri-induced drug metabolising enzymes

The modulation of drug metabolising enzymes by Masheri extract (ME) and Benzo(a)Pyrene [B(a)P] was studied in male Sprague Dawley rats fed different dietary protein levels. Two groups of 21 days old male Sprague Dawley rats were put on a high protein diet (SHP) with 20% Casein, and a low protein diet (SLP) with 3% Casein semisynthetic based diets for 12 weeks. The SLP fed animals showed lower basal levels of the Phase I activating enzymes viz. Cytochrome P450, Benzo(a)Pyrene hydroxylase, Benzphetamine demethylase and Phase II glutathione detoxification system viz. Glutathione (GSH) and Glutathione-S-transferase. ME and B(a)P treatment significantly depleted the glutathione detoxification system in the SLP group whereas an opposite effect was observed in the SHP group. Interstingly, ME and B(a)P treated rats in the SLP group showed a higher percent increase in the hepatic and pulmonary Phase I enzyme activities than those observed in the treated ME/B(a)P treated SHP rats. Furthermore, both ME and B(a)P significantly decreased the hepatic pool of vitamin A while a concomittant increase in that of vitamin C was observed.     

Classical and anaplastic seminoma: difference in survival

Classical and anaplastic seminoma are traditionally treated with radiation therapy and are said to have the same prognosis. A retrospective study was undertaken of 90 seminoma patients treated with radiation therapy between 1961 and 1985. The classical group consisted of 71 patients of whom 50 had stage I and 21 had stage II disease. The anaplastic group consisted of 19 patients of whom ten had stage I and nine had stage II disease. The median follow-up time was 64 months for the entire group. The 10-year relapse-free survival rate for the classical group was 94% and for the anaplastic group was 70% (P less than .05). For patients with classical stage I disease, the relapse-free actuarial survival rate was 98%; for patients with anaplastic stage I disease, it was 64% (P less than .02). For the classical stage II disease group, the relapse-free actuarial survival rate was 84% and for the anaplastic stage II disease group, 75% (P less than .70). Four patients in the classical group (6%) had relapses; of these, one patient had local recurrence of tumor, and three had distant metastases. In the anaplastic group, four patients (21%) had relapses; two patients had local recurrence of tumor, and two had distant metastases. Therefore the data suggest a difference in survival and relapse rates between classical and anaplastic seminoma.     

BRCA2与LIM结构域蛋白FHL2的相互作用

目的：应用酵母双杂交方法筛选BRCA2相互作用蛋白编码基因，验证其相互作用并研究其功能联系。方法：以BRCA2基因3′端片段构建酵母双杂交质粒，筛选正常人乳腺上皮细胞cDNA库，获得编码相互作用蛋白的基因，采用免疫共沉淀、哺乳细胞双杂交和荧光酶测定等方法进一步验证蛋白间相互作用和功能联系．结果：采用酵母双杂交系统筛选，获得了多个编码BRCA2相互作用蛋白的基因，其中包括已知的FHL2蛋白；免疫共沉淀和哺乳动物细胞双杂交试验显示BRCA2和FHL2在体内特异性结合，并证实FHL2在体内形成同源二聚体；转录活性分析发现BRCA2与FHL2有协同转录激活作用。结论：发现BRCA2与FHL2蛋白间相互作用和功能联系，为BRCA2功能研究提供了新的方向。     

Cardiac rehabilitation for women: one size does not fit all.

AIM: To investigate women's perceptions of the contribution of cardiac rehabilitation to their recovery from a myocardial infarction. BACKGROUND AND PURPOSE: Cardiac rehabilitation programs have been based on research with almost exclusively male participants. It was unclear if cardiac rehabilitation programs meet the needs of women. METHOD: Ten women who had experienced one or more myocardial infarctions were interviewed. Data from these interviews were analysed using Glaserian grounded theory. FINDINGS: The core category that emerged from the data was 'regaining everydayness'. Participants worked to regain their 'everydayness' through a basic social process of 'reframing'. Reframing involved coming to terms with what they had experienced and fitting it into their lives. Other categories related to symptom recognition and recovery. CONCLUSION: Cardiac rehabilitation programs contributed to overall recovery from a myocardial infarction in different ways for each participant. Although programs provided information for participants, they failed to provide the type of support needed to effectively aid reframing and recovery. Programs did not meet the needs of all participants and it was apparent that one size does not fit all.     

Fine structural differentiation of germ layers in the mouse at the time of mesoderm formation.

The morphology of early postimplantation mouse egg cylinders was studied using light and electron microscopy. Implantation sites at seven, seven and one-half and eight days of gestation were dissected from the myometrium and whole implants, including both decidua and egg cylinders were processed for electron microscopy. Pre-primitive streak egg cylinders were composed of two germ layers, a tall columnar ectoderm and an outer visceral endodermal layer. Ectodermal cells demonstrated large oval nuclei and an organelle sparse cytoplasm except for many free polyribosomes. The visceral endodermal layer was composed of two cell populations. One visceral endodermal cell type observed was tall columnar in shape and appeared absorptive as demonstrated by many microvilli, pinocytotic profiles and lysosomal granules. This population was confined to extraembryonic regions of the egg cylinder. The second visceral endodermal cell type, squamous in shape, evidenced only a few microvilli, pinocytotic profiles and lysosomal granules. This population was confined to the embryonic region of the egg cylinder. Concurrent with the formation of the primitive streak an increased number of cellular junctions and nuclear pores became evident in the ectoderm. Mesodermal cells were large and stellate-shaped exhibiting many filapodia which made contact with adjacent mesodermal elements. Later the cephalic region of the primitive streak proliferated resulting in the migration of wedge-shaped mass of cells, the head process. At the most ventral extremity of the post-primitive streak egg cylinder the cells of the head process became intimately associated with the ectoderm by areas of focal contact and gap junctions.     

Identification of 21 novel glucokinase (GCK) mutations in UK and European Caucasians with maturity-onset diabetes of the young (MODY)

Maturity-onset diabetes of the young (MODY) resulting from mutations in the glucokinase (GCK) gene accounts for approximately 20% of MODY in the UK. We have performed fluorescent single stranded conformation polymorphism (F-SSCP) analysis or direct sequencing of the GCK gene in 212 patients referred as part of a research cohort or for diagnostic molecular genetic testing. Mutation screening has identified 43 different mutations in 61 individuals, of which 21 are novel. This report details the mutations identified and their associated clinical features.     

A novel serine protease of the mammalian HtrA family is up-regulated in mouse uterus coinciding with placentation

This paper characterizes a novel gene, previously identified as uniquely regulated at implantation in mouse uterus. We cloned its full mRNA sequence encoding a serine protease possessing an IGF-binding domain and named it pregnancy-related serine protease (PRSP). PRSP is structurally similar to mammalian HtrA1 (56% amino acid similarity). Northern analysis revealed that the expression of PRSP mRNA was low before pregnancy, but it was increased at implantation and markedly up-regulated post-implantation. In-situ hybridization localized low levels of mRNA expression to the epithelium and stroma during very early pregnancy, but high expression to the decidual cells on day 8.5, primarily at the mesometrial pole where the placenta was forming. By day 10.5, PRSP mRNA was detected in the placenta. We also cloned an alternatively spliced PRSP mRNA that is expressed at a very low level. We located PRSP gene on chromosome 5 and established its intron/exon structure, which unambiguously explains how the two mRNA variants are produced through alternative splicing. Based on PRSP protein domain structure and its unique expression during pregnancy, we propose that PRSP plays an important role in the formation/function of the placenta.     

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.