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.      

Effect of mifentidine on peptone meal-stimulated gastric acid secretion and plasma gastrin levels in duodenal ulcer patients

Mifentidine is a new H₂-receptor antagonist with distinct characteristics of potency and long plasma half-life. The aim of this study was to evaluate the effects of mifentidine on peptone meal-stimulated gastric acid secretion. Nine duodenal ulcer patients in remission were enrolled in the study and given in double-blind and at random, on two different occasions, a single tablet of 10 or 20 mg mifentidine or placebo according to an incomplete balanced block design. Ninety min after ingestion of the drug, basal gastric secretion was collected for 30 min and volume, pH and acid output determined. Thereafter, the acid output following peptone meal-stimulation was measured for 2 h by a modified version of the intragastric titration method of Thompson and Swierczek. Plasma samples were collected for gastrin and mifentidine determinations. Basal acid output was strongly inhibited by both the low dose (–78%) and the high dose (–98%) (p<0.01). The peptone meal-stimulated acid output was reduced in a dose-dependent manner (–45% by 10 mg and –90% by 20 mg). The drug did not affect the fasting serum gastrin levels but increased, although not significantly, the gastrin response to food. The log of the area under the mifentidine plasma levels correlated linearly with total acid output (p<0.01).The results of this study indicate that mifentidine dose-dependently suppresses basal acid secretion and reduces peptone-stimulated gastric acid secretion in duodenal ulcer patients.This study was supported by a grant from Boehringer Ingelheim, Italy.     

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.     

ASCUS in screening]

The significance and use of the cytological diagnosis "atypical squamous cells of undetermined significance" (ASCUS) remain a major problem in cervical cancer screening. The prevalence of ASCUS by patient age has seldom been investigated. The present paper reports the prevalence of ASCUS in a large series of screening Pap smears from the Italian region of Emilia-Romagna. The study was based on the data collected by the Department of Health of the Emilia-Romagna Region for the first 3-year round (1997-1999) of a population-based screening programme (target age, 25-64 years). The age-specific frequency of ASCUS has been calculated as a prevalence rate per 1000 screened patients. A total of 597,386 women participated in the programme. Women diagnosed with ASCUS (n = 8205 or 13.7 per 1000) accounted for 49% of the recalls for colposcopy (n = 16,871, or 28.2 per 1000). The prevalence of diagnoses of low-grade squamous intraepithelial lesions (LG-SIL) decreased progressively with age while that of high-grade SIL was slightly higher between 30 and 39 years. The prevalence of ASCUS peaked at age 45-49 years (17.3 per 1000 subjects). The observed peak reflects the prevalence of (1) cytological changes closely associated with perimenopausal age and at least compatible with the ASCUS diagnosis, and (2) cytological abnormalities induced by hormone replacement therapy.     

Chromosome abnormalities in breast fibroadenomas

A cytogenetic study on 25 breast fibroadenomas from 17 women is reported. Seven tumors in five patients showed clonal structural chromosome changes. In three patients the breaks involved chromosome 12, occurring in two tumors in band 12p12 and in band 12q15 in all three tumors of one patient. The finding of an identical aberration, t(11;12)(q21;q15), in three adenomas from the same patient strongly suggests a clonal origin of multiple fibroadenomas of the breast.