RASSF1A interacts with microtubule-associated proteins and modulates microtubule dynamics

The candidate tumor suppressor gene RASSF1A is inactivated in many types of adult and childhood cancers. However, the mechanisms by which RASSF1A exerts its tumor suppressive functions have yet to be elucidated. To this end, we performed a yeast two-hybrid screen to identify novel RASSF1A-interacting proteins in a human brain cDNA library. Seventy percent of interacting clones had homology to microtubule-associated proteins, including MAP1B and VCY2IP1/C19ORF5. RASSF1A association with MAP1B and VCY2IP1/C19ORF5 was subsequently confirmed in mammalian cell lines. This suggested that RASSF1A may exert its tumor-suppressive functions through interaction with the microtubules. We demonstrate that RASSF1A associates with the microtubules, causing them to exist as hyperstabilized circular bundles. We found that two naturally occurring tumor-associated missense substitutions in the RASSF1A coding region, C65R and R257Q, perturb the association of RASSF1A with the microtubules. The C65R and R257Q in addition to VCY2IP1/C19ORF5 showed reduced ability to induce microtubule acetylation and were unable to protect the microtubules against the depolymerizing action of nocodazole. In addition, wild-type RASSF1A but not the C65R or the R257Q is able to block DNA synthesis. Our data identify a role for RASSF1A in the regulation of microtubules and cell cycle dynamics that could be part of the mechanism(s) by which RASSF1A exerts its growth inhibition on cancer cells.     

Pharmacological dissection of calcium channel subtype-related components of strontium inflow in large mossy fiber boutons of mouse hippocampus

Several subtypes of voltage-dependent calcium channels (VDCCs) are present in the presynaptic terminals. In the mammalian hippocampus, P/Q-, N-, and R- but not L-type VDCCs are involved in the fast transmitter release from large mossy fiber (MF) boutons, which are associated with CA3 pyramidal cell dendrites. We investigated whether L-type VDCCs are indeed absent in these large MF boutons. With the use of Sr2+ as the Ca2+ substitute, the stimulus-evoked Sr2+ increment (delta[Sr2+]pre) was evaluated fluorometrically. Delta[Sr2+]pre appeared to be proportional to Sr2+ inflow through VDCCs and was specifically attenuated by conventional VDCC subtype-selective antagonists. The P/Q-type selective omega-agatoxin IVA (AgTx(IVA)) blocked delta[Sr2+]pre with an IC50 of 28 nM and by 30-35% at its maximum effective concentration of 0.5 microM. The N-type selective omega-conotoxin GVIA (CgTx(GVIA)) blocked delta[Sr2+]pre with an IC50 of 15 nM and by 20-25% at its maximum effective concentration of 1 microM. The R-type selective SNX-482 blocked delta[Sr2+]pre with an IC50 of 79 nM and by 20-25% at its maximum effective concentration of 1 microM. The effects of these toxins did not overlap at their maximum effective concentrations and about 70-80% of delta[Sr +]pre was blocked by the simultaneous exposure to these toxins. delta[Sr2+]pre component that is resistant to AgTx(IVA), CgTx(IVA), and SNX-482 was significantly potentiated by an L-type agonist, (S)-(-)-Bay K8644, and attenuated by an L-type antagonist, nimodipine, suggesting that L-type VDCCs are present in large MF terminals. The L-type agonist, (+/-)-Bay K8644, also potentiated Sr2+ inflow into individual boutons identified as large MF boutons under confocal microscopy. Almost similar results were observed for Ca2+ inflow-dependent fluorescence increments. L-type VDCCs appear to be present in large MF boutons and mediate a substantial Ca2+ inflow into presynaptic terminals during action potentials.     

Trisomy 21 as the only recurrent chromosomal anomaly in a clinically aggressive ovarian carcinoma

Mature ovarian teratomas are benign ovarian germ cell tumors that usually present with a normal karyotype. There are very few reports describing chromosomal abnormalities in these tumors, none of which are recurrent. In this study we report on a mature teratoma case with clonal chromosomal alterations which include monosomies of chromosomes 6, 14, 16, and 21; trisomies of chromosomes 14 and 21; and deletions of Xq, 5p, 16p, and 17p. Comparative genomic hybridization evaluation of the sample revealed a normal profile. These findings are discussed together with the cytogenetic reports on other cases of ovarian teratomas described in the literature.     

Recurrent pleural effusion complicating liver cirrhosis

BACKGROUND: Pleural effusion (PE) is a rare complication of advanced liver cirrhosis, which may lead to an operation when uncontrolled. The purpose of this study was to evaluate the modality of the occurrence of pleural effusion and to describe its surgical management. METHODS: We studied 21 patients who were referred to the department of thoracic surgery because of massive and recurrent PE caused by liver cirrhosis. The PE was a transudate in 16 patients and an exudate in 5. Talc pleurodesis was attempted in all patients. The patients were divided into two groups. Video assisted thoracoscopy was performed in 13 patients in whom the clinical condition permitted general anesthesia; the pleural cavity was entirely explored before pleurodesis (group 1). Chest tube drainage alone was performed in 8 patients who were unable to undergo general anesthesia; talc pleurodesis was performed through the chest tube in these patients (group 2). RESULTS: In group 1 the PE was right-sided in 8 patients, left-sided in 3, and bilateral in 2. Diaphragmatic defects were observed in 2 patients, and a fluid leak oozing from the diaphragm was observed in 1 patient. Ten patients were considered cured and were without recurrence. Two patients underwent late recurrence before dying from their liver cirrhosis. Only 1 patient had an early recurrence that was cured by complementary talc slurry. In group 2 all patients presented with a right PE; of these, 3 patients died from septic shock caused by pleural infection. Three patients underwent early recurrence but were cured after repeat talc slurry. One patient had a midterm recurrence. One patient had an early recurrence treated by intrahepatic porto-systemic shunt with partial improvement. CONCLUSIONS: Passage of ascites through diaphragmatic defects appears to be the main cause of PE complicating cirrhosis. Patients may benefit from talc pleurodesis. Video assisted thoracoscopy pleurodesis is the technique of choice with consistent results. Repeated talc injection through the drain may prove useful for patients in poor clinical status.     

Roles of histamine receptors in pain perception: a study using receptors gene knockout mice

To study the participation of histamine H1- and H2-receptors in pain perception, H1 and H2 receptor knockout (KO) mice were examined for pain threshold by means of three kinds of nociceptive tasks. These included assays for thermal, mechanical, and chemical nociception. H1KO mice showed significantly fewer nociceptive responses to the hot-plate, tail-flick, tail-pressure, paw-withdrawal, formalin, capsaicin, and abdominal constriction tests. Sensitivity to noxious stimuli in H1KO mice was significantly decreased when compared to wild-type mice. The antinociceptive phenotypes of H2KO were relatively less prominent when compared to H1KO mice. We also examined the antinociceptive effects of intrathecally-, intracerebroventricularly-, and subcutaneously-administered morphine in H1KO and H2KO mice. In these nociceptive assays, the antinociceptive effects produced by morphine were more enhanced in both H1KO and H2KO mice. The effects of histamine H1- and H2-receptor antagonists on morphine-induced antinociception were studied in ICR mice. The intrathecal, intracerebroventricular and subcutaneous co-administrations of d-chlorpheniramine enhanced the effects of morphine in all nociceptive assays examined. In addition, intrathecal co-administrations of cimetidine enhanced the antinociception of morphine in the hot plate tests. These results suggest that existing H1 and H2 receptors play an inhibitory role in morphine-induced antinociception in the spinal and supra-spinal levels.     

Primary small-bowel malignancy in the UK and its association with coeliac disease

BACKGROUND: Malignancies of the small intestine are rare, accounting for <2% of all cancers of the gastrointestinal tract. There is little information about the presentation and prognosis of these tumours, and the frequency of established risk factors. AIM: To estimate the frequency of small-bowel malignancy in the UK, and its relationship to the presence of coeliac disease. DESIGN: Survey of clinicians registered with the British Society of Gastroenterology. METHODS: Data were collected monthly from June 1998 to May 2000. Clinicians (n=1327) were asked by post to report newly diagnosed cases of primary small-bowel malignancy. A form was sent to reporting clinicians, requesting an anonymous identifier, type of malignancy, and whether coeliac disease was present. A detailed questionnaire followed, requesting further clinical and pathological details. RESULTS: Clinico-pathological data were ascertained for 395 cases, including 175 adenocarcinomas, 107 lymphomas and 79 carcinoid tumours. In 13% of adenocarcinoma cases and in 39% of lymphomas, there was a diagnosis of coeliac disease. Survival rates at 30 months for adenocarcinomas, lymphomas and carcinoid tumours were 58%, 45% and 78%, respectively. Prognosis of all tumours was inversely related to stage at presentation, and lymphomas associated with coeliac disease were associated with a poorer prognosis. DISCUSSION: This study provides additional evidence that coeliac disease confers susceptibility to adenocarcinoma of the small bowel, as well as lymphoma. The long time from the onset of symptoms to diagnosis of small bowel tumours is of concern, as this delay is reflected in the high proportion that presented with metastatic disease. Although the absolute risk of malignancy is small, coeliac disease complicated by malignancy appears to be poorly controlled.     

Alterations in GyrA and ParC associated with fluoroquinolone resistance in Enterococcus faecium

High-level quinolone resistance in Enterococcus faecium was associated with mutations in both gyrA and parC genes in 10 of 11 resistant strains. On low-level resistant strain without such mutations may instead possess an efflux mechanism or alterations in the other subunits of the gyrase or topoisomerase IV genes. These findings are similar to those for other gram-positive bacteria, such as Enterococcus faecalis.     

Clinical significance of the translocation (11;14)(q13;q32) in multiple myeloma

The most common chromosomal translocation in multiple myeloma (MM) is t(11;14)(q13;q32). Here, we describe the clinical characteristics of patients with MM who have this translocation. We have identified 24 patients at our institution who had t(11;14)(q13;q32) as determined by standard cytogenetic analysis (CC). Seven patients had the translocation detected at the time of original diagnosis and 17 at the time of relapse. Median survival in all patients after original diagnosis was 43 months; median survival after the translocation was detected was 11.9 months. Four patients had a clinical diagnosis of plasma cell leukemia. Most patients had an elevated beta2-microglobulin (13/20 had >4 microg/ml). The bone marrow (BM) labeling index (LI) of patients, at the time of translocation detection, was elevated in most (median 1.4%, 17/23 patients had BMLI > or = 1%). Of the 24 patients, 19 (79%) died of disease progression and 5 (21%) were alive with disease at last follow-up. Lytic lesions, bone pain, or compression fractures eventually developed in all patients. Patients with MM who have t(11;14)(q13;q32) detected by standard cytogenetics seem to have an aggressive clinical course.     

Toward a disposable low-cost LOC device: heterogeneous polymer micro valve and pump fabricated by UV/ozone-assisted thermal fusion bonding

Herein, a heterogeneous polymer micro valve and pump with a polypropylene (PP) membrane was developed in a low-cost manner via UV/ozone-assisted thermal fusion bonding. The proposed fabrication technique allowed for a geometrically selective bonding; consequently, the membrane was prevented from bonding with the valve seat of the diaphragm micro-valve, without patterning a protection layer or introducing an additional structure. The developed device withstands 480 kPa of static pressure and up to 350 kPa of a vibration pressure, providing sufficient bonding strength for microfluidic actuations. The fabricated micro valve and pump are fully characterized and compared with a poly(dimethylsiloxane) (PDMS) membrane glass device, showing comparable valving and pumping performance. As a result, the robust PP membrane micro valve and pump are simply implemented in a facile manner, and demonstrated excellent performance, which is highly desirable for mass production of disposable lab-on-a-chip (LOC) devices.

Herein, a heterogeneous polymer micro valve and pump with a polypropylene (PP) membrane was developed in a low-cost manner via UV/ozone-assisted thermal fusion bonding.     

Patterns of marriage and reproductive practices: is there any relationship?

Today, a transition from traditional to modern marriages can be observed in many countries. This shift in patterns of marriage has evidently affected childbearing and reproductive practices. This study aimed to examine the relationship between patterns of marriage and reproductive practices in Iran. Hence, 880 married women, aged 15–49 years old, living in the North of Iran were selected using a multi-stage cluster sampling strategy and their patterns of marriage and reproductive practices were cross sectionally studied. The results revealed that there were no significant differences in the reproductive practices by three main patterns of marriage in Babol, Iran. The study also indicated that there were no significant differences in reproductive practices in three patterns of marriage after controlling for socio-economic variables. It seems that apart from the patterns of marriage, other influencing factors are the determinants of fertility in women, and the policy-makers of Iran need to pay attention to these determinants before making any decisions in this area.