Immunohistochemical localization of laminin, collagen IV and fibronectin in dysplasias and neoplasms of the cervix uteri

The distribution of intrinsic components (Laminin and Type IV Collagen) and extrinsic component (Fibronectin) of the Basement Membrane (BM) has been studied in normal uterine cervix (16 cases), in cervical dysplasia (14 cases) and in invasive carcinoma (45 cases). We found that BM staining for Laminin and Type IV collagen is linear and continuous underlying normal and dysplastic epithelium (CIN 1-CIN 2), it shows minor breaks in continuity and alterations of linearity in situ carcinomas (CIN 3), and it disappears in microinvasive areas. In well differentiated invasive carcinomas only focal disruptions of BM around neoplastic nests is noted; in contrast, in moderately and poorly differentiated neoplasias, is found a progressive reduction and loss of staining for Laminin and Type IV Collagen. The results of this study suggest that the distribution patterns of BM intrinsic components are in relation to the histological grade of cervical neoplasias and their invasion ability. On the contrary Fibronectin doesn't show any distribution pattern related to the grade of cervical neoplasias, its immunostaining increased with the rise of both connective tissue stroma production and of vascularity.     

Cyclosporine A affects the organization of cytoskeletal fibrillar proteins in rat thymus

We have evaluated whether cyclosporine A affects cell structure and cytoskeletal proteins of the thymus of Wistar rats. Immunohistochemical analysis showed that expression of the cytoskeletal proteins vimentin and desmin was much higher in epithelial cells, dendritic cells and lymphocytes in the thymus of treated rats than in untreated controls. Protein expression was observed as a positive condensation in a distinct area near the nucleus with a capping-like configuration. An ultrastructural study showed that the amount of cytoskeletal fibrillar structures was increased in the treated rats. The structures were assembled in a limited area of the cell with a nuclear capping-like configuration which was in agreement with the light microscopical observations. Immunoblotting analysis demonstrated that vimentin and desmin had a lower molecular weight in treated rats than in controls (57 and 53 kDa versus 55 and 51 kDa, respectively). The results clearly indicate that cyclosporine A affects the structure of the cytoskeleton suggesting that this could be the first step in its immunosuppressive effects by altering nucleus/cytoplasm signaling.     

Functional consequences of ROMK mutants linked to antenatal Bartter's syndrome and implications for treatment

The antenatal variant of Bartter's syndrome is an autosomal recessive kidney disease characterized by polyhydramnios, premature delivery, hypokalemic alkalosis and hypercalciuria. It is genetically heterogeneous, having been linked recently to mutations in an ATP- sensitive, renal outer medullary K+channel, ROMK, and earlier to mutations in the Na-K-2Cl co-transporter, NKCC2. We characterized four of the mutations reported in three heterozygous ROMK variants of antenatal Bartter's and found that each expressed a distinct phenotype in Sf9 cells. One mutation expressed normal function and appears to be an allelic polymorphism. The other three mutations produced channels with significantly reduced K+fluxes. However, the mechanisms in each case were different and reflected abnormalities in phosphorylation, proteolytic processing or protein trafficking. The different mechanisms may be important in the design of appropriate therapy for patients with this disease.      

Intramesosalpingeal injection of oxytocin in conservative laparoscopic treatment for tubal pregnancy: preliminary results

The objective of this study was to evaluate the efficacy of the local use of oxytocin as adjuvant treatment in conservative surgery for tubal pregnancy. The patients were 25 women with laparoscopic diagnosis of tubal pregnancy who were candidates for salpingotomy. Before salpingotomy, each patient was randomly allocated to intramesosalpingeal injection of 20 IU oxytocin diluted to 20 ml with saline solution or 20 ml saline solution. The surgeon then proceeded with salpingotomy and removal of the pregnancy according to the usual technique. The main outcome measures were bleeding during salpingotomy, ease of removal of the pregnancy, bleeding at the site of the pregnancy, and need for recourse to salpingectomy. Twelve women were randomized to the oxytocin group and 13 to the control group. Examination of the surgeons' assessments of the difficulties encountered at the different stages of surgery revealed statistically significant differences between the oxytocin group and controls in each variable. In particular, the amount of endosalpingeal bleeding after removal of the pregnancy was less in the oxytocin group. In one control patient, persistent bleeding due to incomplete trophoblast removal forced the surgeon to perform salpingectomy. Our results indicate that intramesosalpingeal injection of oxytocin facilitates the performance of conservative laparoscopic treatment for tubal pregnancy.      

Secondary delayed type hypersensitivity to H-2 subregion-coded alloantigens

Secondary type delayed type hypersensitivity (DTH) in mice against class I alloantigens or non-H-2 alloantigens is characterized by an earlier appearance of DTH reactivity after booster immunization compared with the development of DTH reactivity after primary immunization. In contrast to the primary and secondary DTH against class I or non-H-2 alloantigens, the development of secondary DTH against class II alloantigens or a set of alloantigens that includes class II alloantigens is not faster than the development of primary DTH. Thus, primary and secondary immunization with class II alloantigens prevents secondary type DTH reactivity to simultaneously administered class I alloantigens and non-H-2 alloantigens.     

Activation of group I mGluRs elicits different responses in murine CA1 and CA3 pyramidal cells

The group I metabotropic glutamate receptor agonist DHPG has been shown to produce two major effects on CA3 pyramidal cells at rest: a reduction in the background conductance and an activation of a voltage-gated inward current ( I _mGluR(V)). Both effects contribute to depolarising CA3 pyramidal cells and the latter has been implicated in eliciting prolonged epileptiform population bursts. We observed that DHPG-induced depolarisation was smaller in CA1 pyramidal cells than in CA3 cells. Voltage clamp studies revealed that while DHPG elicited I _mGluR(V) in CA3 pyramidal cells, such a response was absent in CA1 pyramidal cells. Both mGluR1 and mGluR5 have been localised in CA3 pyramidal cells, whereas only mGluR5 has been detected in CA1 pyramidal cells. Using mGluR1 knockout mice, we evaluated whether the absence of an I _mGluR(V) response can be correlated with the absence of mGluR1. In these experiments, DHPG failed to elicit I _mGluR(V) in CA3 pyramidal cells. This suggests that the smaller depolarising effects of DHPG on wild-type CA1 pyramidal cells is caused, at least in part, by the absence of I _mGluR(V) in these cells and that the difference in the responses of CA1 and CA3 cells may be attributable to the lack of mGluR1 in CA1 pyramidal cells.