The effect of ethanol on muscarinic receptor-G protein coupling in the rat cortex

To understand the mechanism of ethanol action on G protein-mediated signal transduction pathway, the effect of ethanol on muscarinic receptor-G protein coupling in the rat cerebral cortex was examined. Acetylcholine (ACh)-stimulated G protein GTPase activity was used as an index of receptor-G protein coupling. ACh stimulation of G protein GTPase activity was time- and concentration-dependent, and atropine-sensitive. Rats injected with ethanol (3 g/kg body weight) were sacrificed after 4 hr, and the cerebral cortices removed. The ability of ACh to stimulate GTPase activity was similar in cortical cell membranes obtained from control and ethanol-treated rats; ACh maximally stimulated the enzymatic activity by 22% in membranes from both groups of rats. Next, in cortical cell membranes obtained from control rats (i.e., not injected with ethanol) the ability of ACh to stimulate GTPase activity in the presence of ethanol was examined. ACh stimulated GTPase activity in a concentration-dependent manner; the activity was 12.3 +/- 0.1, 14.5 +/- 0.64, 15.7 +/- 0.54, and 16.1 +/- 0.33 Pi pmol/min/mg protein, at 0, 0.01, 0.1, and 1 mM ACh, respectively (P < 0.05). In the presence of 100 mM ethanol ACh-stimulated GTPase activity was significantly inhibited. The IC50 value of ethanol inhibition of ACh-stimulated GTPase activity was approximately 50 mM. These results suggest that: 1) in vitro, ethanol impairs ACh-stimulated G protein GTPase activity in the rat cortical cell membranes, and 2) in vivo, the acute effects of alcohol on G protein function may be transient and reversible.

Postnatal efficacy of antioxidants in the detoxification pathway of suckling neonates and lactating mice

This study evaluates the comparative efficacy of antioxidant vitamins (ascorbic acid and alpha-tocopherol) and non-vitamin antioxidants (glutathione, cysteine and L-2-oxothiazolidine-4-carboxylate (OTZ)) in modulating the detoxification pathway of lactating dams and suckling murine pups. In dams, 100 mg/kg b.w./day treatment of each of the vitamin and non-vitamin antioxidants induced a significant increase in the hepatic level of acid soluble sulfhydryl (-SH) compared to the modulating efficiency of OTZ, glutathione and alpha-tocopherol in the kidney tissue. In the liver and kidney tissues of suckling pups OTZ and alpha-tocopherol were effective in modulating the -SH level. A statistically significant increase in the hepatic glutathione-S-transferase (GST) level was observed by OTZ, glutathione and alpha-tocopherol, while only OTZ was effective in the kidney tissue of dams and pups. In the murine system, the modulation of cellular GST/GSH status, specifically by OTZ, alpha-tocopherol and interacting antioxidant pool, may potentially ameliorate the pathophysiology of oxidative stress.

Pulmonary endodermal tumor resembling fetal lung: report of a case in a 14-year-old girl

This report describes the clinical and histologic features of a pulmonary tumor in a 14-year-old girl that is most consistent with a rare entity described in the literature as "pulmonary endodermal tumor resembling fetal lung" (PET). This tumor is composed of glycogen-rich columnar cells forming complex glands with focal festooning and mitotic activity, admixed with solid "morules" of cells with eosinophilic cytoplasm and focal nuclear clearing. Patchy tumor necrosis and a bland stroma were also present. Immunoreactivity for carcinoembryonic antigen (CEA), alpha 1-antichymotrypsin, and 12E7 was present in glandular cells and for human chorionic gondatropin (HCG), alpha 1-antichymotrypsin, and 12E7 in morular cells. Ultrastructural features are those of an epithelial tumor. Related entities have been called "pulmonary blastoma lacking sarcomatous elements" and "adenocarcinoma of fetal lung type." Most cases of PET have occurred in adults, and the histologic features thought to have prognostic significance in small published series are applied to our case, in which the patient remains well and without evidence of tumor recurrence or metastasis for 28 months following local resection as the sole treatment.

Conversion disorders in Nottingham: alive, but not kicking

A postal request to general practitioners in a catchment area (population 37,000) identified 18 patients fulfilling criteria for conversion disorder (age range 26-74 years; mean age of onset of first episode 38 years). There was a female preponderance, with two patients from ethnic minority groups. There was a temporal correlation with stress in 13 cases (72%) and a history of sexual abuse in 5 cases (28%). Three clinical groups were identified: acute onset with good premorbid functioning and full recovery; conversion symptoms as part of polysymptomatic presentation, with fluctuating course; and chronic, severely disturbed individuals with a past history of sexual abuse. One third of cases were referred to psychiatrists. There was no case of a missed organic disorder. The details of one case are discussed.

Modulatory potential of smokeless tobacco on the garlic, mace or black mustard-altered hepatic detoxication system enzymes, sulfhydryl content and lipid peroxidation in murine system

The present study evaluates the potential of smokeless tobacco to modify the chemopreventive efficacy of minor dietary constituents, including garlic, mace or black mustard, via modulating the competing pathways of hepatic detoxication system and antioxidant defense mechanism in murine system. Garlic (100 mg/kg b.w. per day) by gavage and mace (1% w/w) or black mustard (1% w/w) in diet induced a significant increase in the levels of glutathione-S-transferase (GST), acid-soluble sulfhydryl (-SH), cytochrome b5 (Cyt.b5) and cytochrome P-450 (Cyt.P-450) in murine liver. The hepatic levels of GST and -SH were significantly depressed whereas microsomal Cyt.b5, Cyt.P-450 and MDA levels were elevated in groups treated with smokeless tobacco (50 or 100 mg/kg b.w. per day). The data revealed the inhibitory potential of smokeless tobacco on garlic-induced hepatic GST/GSH system besides the significant augmentation by smokeless tobacco on garlic or mace or black mustard-induced microsomal cytochromes. The possible implications of modulation in competing bioactivation and detoxication pathways in the process of chemical carcinogenesis are discussed.

Modulatory influence of arecoline on the phytic acid-altered hepatic biotransformation system enzymes, sulfhydryl content and lipid peroxidation in a murine system

The potential of arecoline alkaloid, by direct or translactational exposure, to modify the chemopreventive efficacy of phytic acid, via modulation of hepatic biotransformation system enzymes and antioxidant defence mechanism, was assessed in a murine system. Phytic acid (500 or 1000 mg/kg b.w. per day) induced a statistically significant increase in the hepatic levels of glutathione S-transferase (GST) and sulfhydryl (-SH) in murine females and suckling neonates. The elevated levels of hepatic cytochrome b5 (Cyt. b5), cytochrome P-450 (Cyt. P-450) and the depleted level of malondialdehyde (MDA) were observed in the lactating mice. Arecoline (20 mg/kg b.w. per day) alone did not modulate the hepatic GST and -SH levels although it induced a statistically significant increase in the levels of Cyt. b5, Cyt. P-450 and MDA in the murine system. Phytic acid-modulated hepatic levels of phase II components were depressed whereas phase I enzymes and lipid peroxides were further elevated by arecoline-plus-phytic acid treatment. The implications of direct or translactational modulation in the competing potential pathways of biotransformation system enzymes in the process of chemical carcinogenesis are discussed.

Role of Gq alpha in insulin-stimulated glucose uptake by C6 glioma cells

To investigate the possibility that insulin-stimulated glucose uptake in C6 cells is due to transactivation of a G protein-mediated pathway, the role of Gq alpha in insulin signaling was studied. Insulin stimulation of [3H]2-deoxy-D-glucose (2DG) uptake by C6 cells was time- and concentration-dependent: at a concentration of 1 microM, insulin stimulated 2DG uptake by C6 cells by about 30% (p < 0.05). Pertussis toxin treatment of C6 cells did not alter the ability of insulin (1 microM) to promote 2DG uptake, ruling out the involvement of Gion in insulin-stimulated hexose uptake. Next, C6 cells were transfected with Gq alpha cDNA for 48 h, challenged with 1 microM insulin, and 2DG uptake by the cells was determined. Insulin-stimulated 2DG uptake was 1.14 +/- 0.03 and 1.75 +/- 0.19 nmol/min/mg protein in mock- and Gq alpha-transfected cells, respectively (p < 0.05); insulin stimulated 2DG uptake in Gq alpha-transfected cells by 54%. These results suggest an involvement of Gq alpha in the transactivation of the G protein signal transduction pathway by insulin.

Comparative histopathology of scabies versus nodular scabies

Comparative histopathology was studied in 25 cases of scabies versus 25 cases of nodular scabies which were selected from Dermato-Venereology out patients. Salient differences observed were that in scabies lifting of stratum corneum at places was seen in all 100% cases, spongiosis in 100%, spongiotic vesicles in 28%, burrows in 56%, mite in 40% and vasculitis in 28% whereas in nodular scabies acanthosis was seen in 100%, pseudo epitheliomatous hyperplasia in 8%, burrows in 48%, mite in 24% and vasculitis in 84%. In nodular scabies, dermal infiltrate in 32% cases was arranged as lymphoid follicles with admixture of plasma cells and eosinophils.

Comparison between two techniques for modeling interface conditions in a porous coated hip endoprosthesis

The geometric and material non-linearities occurring at implant interfaces require a non-linear foate element analysis to simulate accurately the interface conditions. Reviewing the literature, it was found that mainly three different non-linear interface elements have been developed to simulate the interface bounding conditions. While these different types of interface elements have been used to predict micromotions and interface stresses for different geometrical configurations and under different loading conditions, no study has attempted to compare the performance of these elements under similar conditions. The objective of this study is to compare two non-linear interface modeling techniques using gap elements and joint/interface elements. A simplified three-dimensional geometrical model was developed to compare interface stresses and micromotions for both fully and partially coated models. The results show that both non-linear modeling techniques predict dissimilar results for the interface stresses in bone and prosthesis sides. For the fully coated model, and on the bone side, joint/interface elements predict a gradual decrease in stresses from distal end to proximal end. However, 'gap' elements predict almost constant stresses in the mid-stem region and higher stresses at the distal end. On the prosthesis side, small stress differences occur only at the distal and proximal ends. For the partially coated model, most significant stress dissimilarities occur in the uncoated section. The relative micromotions at the interface were also determined. It was found that micromotion patterns obtained using both techniques were similar with higher magnitudes in the case of the 'gap' elements.

The chemistry of the S-nitrosoglutathione/glutathione system

S-Nitrosothiols have generated considerable interest due to their ability to act as nitric oxide (NO) donors and due to their possible involvement in bioregulatory systems-e.g., NO transfer reactions. Elucidation of the reaction pathways involved in the modification of the thiol group by S-nitrosothiols is important for understanding the role of S-nitroso compounds in vivo. The modification of glutathione (GSH) in the presence of S-nitrosoglutathione (GSNO) was examined as a model reaction. Incubation of GSNO (1 mM) with GSH at various concentrations (1-10 mM) in phosphate buffer (pH 7.4) yielded oxidized glutathione, nitrite, nitrous oxide, and ammonia as end products. The product yields were dependent on the concentrations of GSH and oxygen. Transient signals corresponding to GSH conjugates, which increased by one mass unit when the reaction was carried out with 15N-labeled GSNO, were identified by electrospray ionization mass spectrometry. When morpholine was present in the reaction system, N-nitrosomorpholine was formed. Increasing concentrations of either phosphate or GSH led to lower yields of N-nitrosomorpholine. The inhibitory effect of phosphate may be due to reaction with the nitrosating agent, nitrous anhydride (N2O3), formed by oxidation of NO. This supports the release of NO during the reaction of GSNO with GSH. The products noted above account quantitatively for virtually all of the GSNO nitrogen consumed during the reaction, and it is now possible to construct a complete set of pathways for the complex transformations arising from GSNO + GSH.

Effects of ethanol on GLUT1 protein and gene expression in rat astrocytes

Effects of ethanol on glucose transporter gene expression were examined in cultured rat astrocytes. Exposure to 50 or 100 mM ethanol for 18 hours significantly inhibited hexose uptake and reduced the number of glucose transporters, as indicated by binding studies with cytochalasin B. Indirect immunofluorescence and immunoperoxidase staining showed marked reduction of the GLUT1 glucose transporter by exposure to 100 mM ethanol for 5 or 18 hours, but no obvious change in response to 50 mM ethanol. Western blot analysis showed GLUT1 protein levels to be decreased by 52 +/- 12% (p < 0.05) after exposure to 100 mM ethanol for 18 hours. In situ hybridization histochemistry indicated an increase in steady-state GLUT1 mRNA in astrocytes exposed to 50 or 100 mM ethanol for 5 or 18 hours. Quantitation of GLUT1 mRNA levels by northern blot analysis showed that GLUT1 mRNA levels were increased by 59 and 112% in cells treated for 5 h with 50 and 100 mM ethanol, respectively. A similar effect was observed after treatment for 18 hours, but ethanol did not alter actin gene expression. Experiments using actinomycin D to block RNA synthesis suggest that this increase in steady-state mRNA level results from increased message stability. These results suggest that ethanol acts on GLUT1 gene expression at the post-transcriptional level.

Immunochemical structure of the OmpD porin from Salmonella typhimurium

The OmpD porin was isolated and purified from Salmonella typhimurium strain SH 7454 (ompC::Tn10), digested with cyanogen bromide (CNBr) and the peptide fragments were separated by SDS-PAGE. N-terminal sequencing identified a total of 96 residues from four distinct peptides. The sequence showed that OmpD is homologous to NmpC (75% identity), Lc(75%) and OmpC (70%) from Escherichia coli, and OmpC (68%) from S. typhimurium. The sequence was essentially identical to the translated sequence of an nmpC-like gene of S. typhimurium, currently placed at 38.6 centisomes of the chromosome. Our results and other data suggest, however, that this gene is actually the ompD gene, which is more correctly placed in the 34 centisome region of the chromosome. The CNBr-generated peptides were also screened with 16 anti-S. typhimurium OmpD monoclonal antibodies by Western blotting. These results, in conjunction with the prediction of the OmpD folding pattern based on the known three-dimensional structure of E. coli OmpF, showed a close immunological relationship among S. typhimurium OmpD and E. coli NmpC and Lc, and a strong conservation of sequences within the transmembrane beta strands of these porins and E. coli OmpC, PhoE and OmpF, and Salmonella typhic OmpC.

Bicarbonate inhibits N-nitrosation in oxygenated nitric oxide solutions

N-Nitrosation in oxygenated nitric oxide (NO middle dot) solutions was previously shown to be significantly inhibited by phosphate and chloride presumably by anion scavenging of the nitrosating agent nitrous anhydride, N2O3 (Lewis, R. S., Tannenbaum, S. R., and Deen, W. M. (1995) J. Am. Chem. Soc. 117, 3933-3939). Here, bicarbonate is shown to exhibit this same inhibitory effect. Rate constants for reaction of morpholine, phosphate, and bicarbonate with N2O3 relative to N2O3 hydrolysis at pH 8.9 were determined to be (3.7 +/- 0.2) x 10(4) M-1, (4.0 +/- 0.9) x 10(2) M-1, and (9.3 +/- 1.5) x 10(2) M-1, respectively. The morpholine and phosphate rate constants at pH 8.9 are similar to those reported at pH 7.4 assuring that these results are relevant to physiological conditions. The rate constant for this previously unrecognized reaction of bicarbonate with N2O3 suggests the strong scavenging ability of bicarbonate; accordingly, bicarbonate may contribute to reducing deleterious effects of N2O3. This is biologically important due to substantial bicarbonate concentrations in vivo, approximately 30 mM. Bicarbonate was previously shown to alter peroxynitrite reactivity; however, carbon dioxide is the probable reactive species. Bicarbonate is therefore potentially important in determining the fate of two reactive species generated from nitric oxide, N2O3 and ONOO-, and may thus act as a regulator of NO middle dot-induced toxicity.

Immunoprotection by monoclonal antibodies to the porins and lipopolysaccharide of Salmonella typhimurium

Monoclonal antibodies (MAbs) were raised against the outer membrane (OM) antigens of Salmonella typhimurium. Enzyme-linked immunosorbent assays and Western immunoblots indicated that 10 MAbs in the panel were specific for surface epitopes, and 10 recognized buried epitopes of OmpC or OmpD porins; three MAbs reacted with smooth lipo-polysaccharide (LPS), two bound rough LPS, and the remaining three MAbs apparently reacted with a porin-LPS complex. We screened these MAbs and immune polyclonal sera in CAF1 (Ity) mice for their relative immunoprotective potential against a challenge with 10 to 500 LD50 of the virulent S. typhimurium LT-2 strain WB600, or against two LD50 of purified OM from this organism. Polyclonal sera that contained high titers of antibodies to porin monomers and trimers, and LPS, provided significant protection (33 to 100% survivors). Antiporin MAbs, when administered individually, did not protect or prolong the survival of mice. A mixture of MAbs with specificity for the surface, but not buried epitopes of porins, prolonged the survival of mice against endotoxemia, but none provided significant protection against mouse typhoid. MAbs specific for smooth (but not rough) LPS on the other hand, conferred significant protection against endotoxemia and mouse typhoid. Finally, MAbs that presumably recognized epitopes present in porin-LPS complexes, were also protective against endotoxemia and mouse typhoid. These results support the role of antibodies to LPS O-chains, porin-LPS complexes, and to a lesser degree, native porins in acquired resistance to infection by S. typhimurium.

Sarcoid heart disease: a rare cause of chest pain and malignant cardiac arrhythmia in a young Asian man. A case report

Cardiac sarcoidosis is a disease of young adults. In most cases, it presents with sudden death, arrhythmia, conduction disorders, heart failure, or cardiomyopathy. The authors describe a young Indo-Asian man with cardiac sarcoidosis who presented acutely with chest pain and malignant cardiac arrhythmias. The diagnosis of cardiac sarcoidosis should be considered in all young patients with unexplained arrhythmias or heart failure or in cases of sudden death.

Ethanol-induced changes in insulin-like growth factors and IGF gene expression in the fetal brain

Brain growth retardation is a major feature of the fetal alcohol syndrome (FAS). Insulin-like growth factors (IGF-I and IGF-II) have been shown to exert significant metabolic and growth-promoting effects. Previously, we showed that circulating levels of IGF-I as well as hepatic gene expression of both IGFs were decreased in newborn offspring of rats fed ethanol during pregnancy. This study investigated the effects of maternal ethanol ingestion on fetal rat brain growth and on levels of IGF-I and IGF-II, as well as their mRNAs, in fetal brain. IGF-binding protein (IGFBP) levels also were determined. Rats were fed 5% w/v ethanol in a liquid diet during gestation (EF group). Weight-matched animals were pair-fed equicaloric control diet (PF group) or were fed ad libitum (AF group). The mean fetal brain weight of EF offspring was 13% and 16% lower (P < 0.01) than that of PF and AF offspring, respectively. Body weight of EF pups was decreased to a greater extent, resulting in higher brain to body weight ratios in EF pups than in either control group (P < 0.05). IGF-I levels in EF pups decreased by 33% and 41% compared with the corresponding PF and AF values (P < 0.01). IGF-I mRNA levels decreased by 27% and 40% compared with PF and AF values, respectively. A positive correlation was observed between brain IGF-I level and brain weight (r = 0.561, P < 0.01). IGF-II levels were not affected despite a 50% decrease in IGF-II expression. In PF animals, the fetal brain IGF-I and IGF-II mRNA levels were reduced by 28% and 21%, apparently in response to undernutrition. IGF-binding proteins levels were low in the EF group but not statistically significant compared with control values. The diminished fetal brain concentration of IGF-I and decreased gene expression of IGFs may play a role in brain growth retardation associated with FAS.

Syngeneic bone marrow transplantation without conditioning in a patient with paroxysmal nocturnal hemoglobinuria: in vivo evidence that the mutant stem cells have a survival advantage

A 10-year-old girl with paroxysmal nocturnal hemoglobinuria (PNH) received an infusion of syngeneic bone marrow without preparative marrow ablation or immunosuppression. Following transplant, the patient became asymptomatic in concordance with an increase in the percentage of peripheral blood cells with normal expression of glycosyl phosphatidylinositol-anchored proteins (GPI-AP). However, molecular analysis suggested engraftment of a relatively small number of donor stem cells and persistence of an abnormal stem cell with mutant PIG-A. During 17 months of observation, the percentage of cells with normal GPI-AP expression gradually decreased, while intravascular hemolysis progressively increased. Approximately 16.5 months post-transplant, the patient once again became symptomatic. Together, these results indicate that syngeneic marrow infusion provided a clinical benefit by increasing the proportion of erythrocytes with normal expression of GPI-anchored complement regulatory proteins without supplanting the abnormal stem cells. However, evidence of insidious disease progression following the marrow infusion implies that the abnormal stem cells have a survival advantage relative to the transplanted stem cells. Thus, these studies contribute in vivo data in support of the hypothesis that PNH arises as a consequence of a pathological process that selects for hematopoietic stem cells that are GPI-AP-deficient.