Intercellular communication in the rat anterior pituitary gland: an in vivo and in vitro study

The concept of "stimulus-secretion coupling" suggested by Douglas and co-workers to explain the events related to monamine discharge by the adrenal medulla (5, 7) may be applied to other endocrine tissues, such as adrenal cortex (36), pancreatic islets (4), and magnocellular hypothalamic neurons (6), which exhibit a similar ion-dependent process of hormone elaboration. In addition, they share another feature, that of joining neighbor cells via membrane junctions (12, 26, and Fletcher, unpublished observation). Given this, and the reports that hormone secretion by the pars distalis also involves a secretagogue-induced decrease in membrane bioelectric potential accompanied by a rise in cellular [Ca++] (27, 34, 41), it was appropriate to test the possibility that cells of the anterior pituitary gland are united by junctions.     

Natural products as starting points for future anti-malarial therapies: going back to our roots?

Background

Population movements along the Thailand-Cambodia border, particularly among highly mobile and hard-to-access migrant groups from Cambodia and Myanmar, are assumed to play a key role in the spread of artemisinin resistance. Data on treatment-seeking behaviours, knowledge and perceptions about malaria, and use of preventive measures is lacking as characteristics of this population prevent them from being represented in routine surveillance and the lack of a sampling frame makes reliable surveys challenging.

Methods

A survey of migrant populations from Cambodia and Myanmar was implemented in five selected rural locations in Thailand along the Thai-Cambodian border using respondent driven sampling (RDS) to determine demographic characteristics of the population, migratory patterns, knowledge about malaria, and health-care -seeking behaviours.

Results

The majority of migrants from Myanmar are long-term residents (98%) with no plans to move back to Myanmar, understand spoken Thai (77%) and can therefore benefit from health messages in Thai, have Thai health insurance (99%) and accessed public health services in Thailand (63%) for their last illness. In comparison, the majority of Cambodian migrants are short-term (72%). Of the short-term Cambodian migrants, 92% work in agriculture, 18% speak Thai, 3.4% have Thai health insurance, and the majority returned to Cambodia for treatment (45%), self-treated (11%), or did not seek treatment for their last illness (27%).

Conclusion

Most highly mobile migrants along the Thai-Cambodia border are not accessing health messages or health treatment in Thailand, increasing their risk of malaria and facilitating the spread of potentially resistant Plasmodium falciparum as they return to Cambodia to seek treatment. Reaching out to highly mobile migrants with health messaging they can understand and malaria diagnosis and treatment services they can access is imperative in the effort to contain the spread of artemisinin-resistant P. falciparum.     

Immunoexpression of CD30 and CD30 ligand in deciduas from spontaneous abortions

In the present study, using immunohistochemistry, we studied the expression of CD30 and CD30-L in 35 deciduas obtained from women following elective abortion during normal physiological gestation and in 60 deciduas obtained from women after spontaneous abortion with or without signs of inflammation. The main difference was noticed in the first trimester of gestation in which was found a decrease in CD30/CD30-L-positive decidual glandular and stromal cells in a greater number of cases of spontaneous abortions with respect to cases of physiological pregnancies (70% vs 50%, p<0.05). In addition, deciduas from spontaneous abortions with inflammation and without inflammation reacted similarly. The reduced expression of CD30 and CD30-L and their cellular pattern detected in the deciduas from spontaneous abortions suggest that the CD30/CD30-L system is crucial for preventing abortions in the first trimester. Furthermore, the distinctive expression of CD30/CD30-L in deciduas from physiological pregnancies may indicate that the CD30/CD30-L system exerts its main role in the first trimester.     

Airway cellularity, lipid laden macrophages and microbiology of gastric juice and airways in children with reflux oesophagitis

Background and methods

Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR.

Results

We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 × 10⁵ viral copies/ml in nasal lavage and 1.88 × 10⁵ viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD.

Conclusion

HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely.     

Relationship between immunoexpression of mucin peptide cores MUC1 and MUC2 and Lauren's histologic subtypes of gastric carcinomas

Laurèn's system subdivides gastric cancers into an intestinal type and a diffuse type. This histological classification mirrors histogenetic hypotheses according to which the intestinal-type cancer derives from intestinal metaplasia and dysplasia, while the diffuse-type originates directly from gastric mucosa, with or without a preceding non-metaplastic dysplasia. Studies concerning mucins expression in gastric neoplastic and preneoplastic lesions have provided contradictory data concerning such histogenetic relationships. The aim of the present study was to verify whether a correlation between mucins phenotype and Lauren's classification subsists. 40 gastric adenocarcinomas, subdivided, according to Laurèn's classification, into 27 intestinal-type, 10 diffuse-type and 3 unclassified cases, were examined for MUC1 and MUC2 immunohistochemical expression. Intestinal-type carcinomas displayed a MUC1-positive staining in 23/27 cases and a MUC2-positive immunoreaction in 10/27 cases. Diffuse-type carcinomas expressed MUC1 in 3/10 and MUC2 in 8/10 cases, respectively. According to the mucins expression pattern, three phenotypes were identified: the gastric phenotype (MUC1+/MUC2-); the gastro-intestinal phenotype (MUC1+/MUC2+) and the intestinal phenotype (MUC1-/MUC2+). The gastric phenotype was significantly higherin intestinal-type adenocarcinomas, whereas cases showing an intestinal phenotype were significantly more frequent in diffuse-type adenocarcinomas. These findings provide evidence for a lack of correlation between Lauren's classification and MUC1 and MUC2 phenotypes. In particular, the term intestinal-type tumour as referred to gland-forming gastric cancer does not seem to reflect an immunohistochemical phenotype.     

植物的遗传转化及其应用(英文)

近年来,植物遗传转化研究有了长足的发展。已经达到能够通过简单的遗传控制手段研究具有新表现型的植物,甚至达到进入商业化的程度。这些手段包括植物生物学的主要研究技术以及植物组织培养和树种改良的一些实用方法。尽管采用农瘤杆菌和鸟枪法等技术的植物遗传转化系统已经得到了广泛的应用,但是在如何开发具有能够得到控制表达的转基因高产植物方面,在如何使所得到的转基因植物远离遗传危害等方面,目前的转化系统遇到了极大的技术挑战。已经提出了各种各样的方法用于将新基因稳定地导入120多种不同植物的核基因组。本文将讨论这些遗传转化系统所需的生物学要求和实际应用方面的需求、基因转化和转基因表达的研究策略、遗传转化植物的鉴定以及转基因植物与大众的认可。本文将分为七个部分加以讨论:一、导言;二 、基因转化到细胞里的方法;三、植物遗传转化策略;四、植物遗传转化的鉴定;五、植物遗传转化的实际应用;六、转基因植物与环境;七、未来植物遗传转化的需求与发展方向。     

Properties of microtubule sliding disintegration in isolated tetrahymena cilia

Properties of the sliding disintegration response of demembranated tetrahymena cilia have been studied by measuring the spectrophotomeric response or turbidity of cilia suspensions at a wavelength of 350 nm relative to changes in the dynein substrate (MgATP(2-)) concentration. The maximum decrease in turbidity occurs in 20 muM ATP, and 90 percent of the decrease occurs in approximately 5.9 s. At lower ATP concentrations (1-20 muM), both the velocity and magnitude of the turbidity decreases are proportional to ATP concentration. The velocity data for 20 muM ATP permit construction of a reaction velocity curve suggesting that changes in turbidity are directly proportional to the extent and velocity of disintegration. At ATP concentrations more than 20 muM (50muM to 5mM), both velocity and magnitude of the turbidimetric response are reduced by approximately 50 percent. This apparent inhibition results in a biphasic response curve that may be related to activation of residual shear resistance or regulatory components at the higher ATP concentrations. The inhibitory effects of elevated ATP can be eliminated by mild trypsin proteolysis, whereupon the reaction goes to completion at any ATP concentration. The turbidimetric responses of the axoneme-substrate suspensions are consistent with the extent and type of axoneme disintegration revealed by electron microscope examination of the various suspensions, suggesting that the turbidimetric assay may prove to be a reliable means for assessing the state of axoneme integrity.     

Immunohistochemical expression of HGF, c-MET and transcription factor STAT3 in colorectal tumors

By immunohistochemistry, we have investigated the expression of hepatocyte growth factor (HGF), HGF-R or c-met and the transcritor factor STAT3 in a series of 80 colorectal tumours (40 adenomas and 40 adenocarcinomas). The expression of HGF, c-met and STAT3 was revealed in 40/40 (100%) of adenomas and in 26/40 (65%) of adenocarcinomas; the remaining 14/40 (35%) carcinomas expressed c-met but failed to express HGF and STAT3. Positive immunoreaction score was defined through the number of stained cells: low (1-10%), moderate (11-50%) and high (>51%). In adenomas, the HGF immunoreaction was high in 33 (82.5%) and moderate in 7 (17.5%); the c-met staining was high in 3 (7.5%) and moderate in 37 (92.5%); and the STAT3 reactivity was high in 25 (62.5%) and moderate in 15(37.5%). In carcinomas, the HGF immunoreaction was moderate in 21 (80.7%) and low in 5 (19.2%); the c-met staining was high in 14 (35%), moderate in 25 (62.5) and low in 1 (2.5%); and the STAT3 reactivity was moderate in 17 (65.3%) and low in 9 (34.6%). In both type of lesions, HGF and c-met showed a membranous and cytoplasmic location. In adenomas, STAT3 was detected in cytoplasm and nucleus and in carcinomas it was limited to cytoplasm. While the HGF/c-met/STAT3 expression in adenomas was significantly different from carcinomas (c2 = 17, p < 0.0001), no correlation was found among HGF, c-met, or STAT3 immunostaining with histotype or degree of dysplasia in adenomas and the same for histotype, grading or staging in carcinomas. These features, suggesting a role of the HGF/c-met/STAT3 signal in colon tumorigenesis, indicate that a reduced expression of HGF and c-met is associated to progression of adenoma into carcinoma.     

Immunohistochemical expression of rabphilin-3A-like (Noc2) in normal and tumor tissues of human endocrine pancreas

Involvement of rabphilin-3A-like (RPH3AL), or Noc2, the potential effector of Ras-associated binding proteins Rab3A and Rab27A in the regulation of exocytotic processes in the endocrine pancreas has been demonstrated in experimental models. Noc2 expression together with other regulatory molecules of the exocytotic machinery in human tissues, however, has not been studied. We evaluated immunohistochemical expression of the key molecules of the exocytotic machinery, Noc2, Rab3A, Rab27A, and RIM2, together with the characteristic islet cell hormones, insulin and glucagon in normal and endocrine tumor tissues of human pancreas. Normal pancreatic islets were stained for all of these proteins and showed strong cytoplasmic localization. A similar pattern of strong cytoplasmic expression of these proteins was observed in the majority of endocrine tumors. By contrast, the exocrine portions of normal appearing pancreas completely lacked Rab27A staining and showed decreased expression of the proteins, Noc2, Rab3A, and RIM2. The staining pattern of Noc2 and Rab27A was similar to the staining pattern of glucagon-producing cells within the islets. The concomitant expression of Noc2 with these molecules suggests that Noc2 may serve as an effector for Rab3A and Rab27A and that it is involved in the regulation of exocytosis of the endocrine pancreas in humans.