Search PubMed⌕ Search

Biomedical subjects

K Gill

Publications and source records attributed to K Gill.

At least 109 records · Page 6Linked to original sources
PubMed1984

Zimeldine: a review of its effects on ethanol consumption.

This review evaluates the literature and describes an extensive series of experiments which examined the effects of zimeldine , its metabolite norzimeldine and other serotonin and norepinephrine reuptake inhibitors on voluntary ethanol consumption in rats. The results of these experiments indicate that drugs which specifically inhibit serotonin reuptake are capable of decreasing voluntary ethanol consumption. The behavioral mechanism through which these drugs exert their effects seems to be extinction of the primary reinforcing properties of alcohol. These effects seem to be partially attenuated both by drugs which modulate the norepinephrine system as well as by the serotonin postsynaptic receptor blocker methergoline. The data presented in this review are discussed in terms of the involvement of the serotonin and norepinephrine systems in the mechanism of action of these drugs. In addition, several alternative hypotheses concerning the nature of the phenomenon are offered. Finally, the implications of these data for the possible development of a treatment procedure for problem drinkers is discussed.

Alcohol Drinking↗
PubMed1984

The role of computerized tomographic scanning in the evaluation of major pelvic fractures.

Twenty-five patients with double vertical fractures of the pelvic ring had evaluations by both plain radiography and computed-tomography scanning of the pelvis. In eight of the twenty-five patients, the interpretation that was made from the plain radiographs, based on the classification of Pennal et al., changed when additional anatomical information was provided by the computed-tomography scan. We recommend that computed tomography be used for: (1) double vertical fracture-dislocations of the pelvic ring in which plain radiographs are inadequate to judge pelvic stability, (2) fractures of the pelvic ring with extension into the acetabulum, and (3) major injuries to the hemipelvis that are to be treated by open reduction and internal fixation. However, due to the increased cost and radiation exposure, routine computed-tomography scanning is not justified for all injuries to the pelvic ring.

Adolescent↗
PubMed1983

Ventilatory depression related to plasma fentanyl concentrations during and after anesthesia in humans.

Twenty-four patients were allocated randomly into four groups for the study of the pharmacokinetics of, and effects on postoperative ventilation of, two doses of fentanyl (10 micrograms/kg or 25 micrograms/kg) administered at the start of general anesthesia in which ventilation was controlled at a fixed volume, but arterial PCO2 was adjusted to a range of either 38-42 torr, or 20-25 torr. During the first 2 hr after anesthesia, ventilatory depression (CO2 responsiveness decreased to less than 50% of awake values, PaCO2 greater than 48 torr) occurred only in patients who had received 25 micrograms/kg fentanyl, and was more marked in patients who were hyperventilated to a low PaCO2 during anesthesia. Plasma fentanyl concentrations associated with 50% depression of CO2 responsiveness were in the range 1.5-3.0 ng/ml, the lower values found in patients hyperventilated to a low PaCO2. Whole-body clearance of fentanyl was significantly decreased by hypocapnic hyperventilation.

Adult↗
PubMed1981

Relationship between benzo(a)pyrene-induced DNA base modification and frequency of reverse mutations in mutant strains of Salmonella typhimurium.

Salmonella typhimurium cells (TA98 and TA100) were incubated with [3H]benzo(a)pyrene ([3H]BP) and induced rat liver microsomes. The BP-induced cytotoxicity and His+ reverse-mutation frequencies were determined, and bacterial DNA hydrolysates were chromatographed on Sephadex LH-20. Analysis indicated three principal DNA adducts formed from two diastereoisomeric BP diol-epoxides and a 9-hydroxy-benzo(a)pyrene metabolite. An 8.6-fold increase in TA100 cell concentration in the microsome incubation was paralleled by a 7.2-fold decrease in total adducts per cell and a 7.4-fold decrease in mutation frequency. Separate TA98 incubations were titrated with increasing concentrations of [3H](+/-)-7 beta, 8 alpha-dihydroxy-9 alpha, 10 alpha-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene ([3H]anti BP diol-epoxide), [3H](+/-)-7 beta, 8 alpha-dihydroxy-9 beta, 10 beta-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene [3H]syn BP diol-epoxide), or [3H]9-hydroxybenzo(a)pyrene. Linear, nonsaturated increases in DNA adduct levels were seen up to the highest observed concentrations of 4.00 microM BP diol-epoxide or 6.00 microM 9-hydroxybenzo(a)pyrene in both TA98 and TA100 cells. The increasing adduct levels were accompanied by linearly increasing mutation frequencies. At equivalent concentrations of the two DP diol-epoxides, an average of 8.2-fold more base substitution mutations (TA100) were seen than frameshift mutations (TA98). The results also indicate significant differences in absolute mutagenic efficiency (mutation frequency/unit modified DNA) between these three covalent DNA ligands (TA98, syn BP diolepoxide greater than 9-hydroxy-4,5-epoxy-benzo(a)pyrene greater than anti BP diol-epoxide; TA100, 9-hydroxy-4,5-epoxy-benzo(a)pyrene greater than syn BP diol-epoxide greater than anti BP diol-epoxide).

Animals↗
PubMed1981

Leucocyte migration inhibition response to tissue antigens in asymptomatic individuals infected with Trypanosoma cruzi.

The direct leucocyte migration inhibition test was used to study 31 asymptomatic humans chronically infected with Trypanosoma cruzi and 23 normal uninfected controls. The antigenic preparations used were made from mouse and guinea-pig heart, skeletal muscle, kidney, liver and brain. Positive responses were found in the parasite-infected individuals to kidney, liver and brain antigen but not to antigen prepared from heart of skeletal muscle tissue. No correlation was found between T. cruzi antibody titres and migration index values to these various antigens. On the other hand, a positive correlation was only noted between the titres of tissue-reacting immunoglobulins and the migration indices induced by brain antigens: when titres of tissue-reacting immunoglobulins were elevated, less leucocyte migration inhibition was detected.

Adult↗
PubMed1980

Survey of virally mediated permeability changes.

1. Sendai virus causes permeability changes when added to freshly isolated brain cells (cerebellum or ependymal cells) or to a culture of forebrain cells. 2. Sendai virus causes permeability changes when added to organ cultures of ferret lung or nasal turbinate. Influenza virus causes no permeability changes under these conditions. 3. Rabies virus and vesicular-stomatitis virus, in contrast with Sendai virus, do not cause permeability changes in BHK cells or Lettrée cells. 4. Serum from patients suffering from viral hepatitis does not cause permeability changes in human leucocytes; addition to Sendai virus causes permeability changes. 5. It is concluded that permeability changes accompanying viral entry occur only with certain types of paramyxovirus, but that there is little restriction on cell type. 6. MDBK cells infected with Sendai virus show permeability changes during viral release, similar to those that occur during viral entry. Because these changes do not appear to be restricted to paramyxoviruses, they may have considerable clinical significance.

Animals↗
PubMed1980

Changes in the surface membrane during myoblast fusion.

1. During fusion of chick-embryo myoblasts in culture, the surface membrane is affected as follows. Uptake of 2-aminoisobutyrate and 2-deoxyglucose, each of which is concentrated 20-fold relative to its concentration in the medium, is unaltered; uptake of alpha-methyl glucoside and choline (15 mM), each of which equilibrates relative to its concentration in the medium, approximately doubles. An approximate doubling also occurs in iodinatable surface protein (and in total protein) and in cell surface area as judged by light-microscopy. Adenylate cyclase (in the absence or the presence of fluoride) increases by more than 2-fold. 2. It is concluded that, during myoblast fusion cells increase in size, and this is reflected in an increased rate of simple diffusion; the rate of facilitated processes such as the uptake of amino acids and sugars, on the other hand, remains unaltered, though the activity of certain enzymes is increased. These results indicate that specific changes in the function of surface membrane occur during myoblast fusion in vitro.

Aminoisobutyric Acids↗
PubMed1980

Induction of stable L-forms of Staphylococcus aureus and Streptococcus faecalis.

Stable L-forms were induced from Staphylococcus aureus and Streptococcus faecalis. These formed typical foamy L-colonies and showed large and small round bodies. They grew continuously on routine antibiotic-free nutrient broth and blood agar media for 12 passages without reversion to their parental forms. At different concentrations of penicillin various morphological forms were observed. Effect of sucrose, normal horse serum and penicillin on their adaptation and stabilization is discussed.

Adaptation, Physiological↗
PubMed1980

Biological properties of L-forms and their parent bacteria.

L-forms of Staphylococcus aureus, Streptococcus faecalis, Listeria monocytogenes and Salmonella typhy and their parent bacteria were examined for biological properties and compared with their parental forms. Some L-forms differed from their parent bacteria and required a longer incubation period.

Carbohydrate Metabolism↗
PubMed1977

Binding of lectins to Streptococcus mutans cells and type-specific polysaccharides, and effect on adherence.

The lectin concanavalin A (Con A) agglutinated the cells of 13 of 15 strains of the seven serotypes of Streptococcus mutans in an 18-h incubation period. Strains of types a, d, f, and g agglutinated within 2 h. Strains of a, d, and f were also agglutinated in 2 h by the castor bean lectin RCA. S. sanguis, S. salivarius, S. bovis, Actinomyces viscosus, A. naeslundii, and Lactobacillus plantarum were agglutinated within 2 h. The S. mutans type f polysaccharide was precipitated by Con A. The a, b, c, d, and e polysaccharides were not precipitated. Glucan from d and e strains of S. mutans and dextran T2000 were also precipitated by Con A. D-glucose inhibited the agglutination of type f cells by Con A and the agglutination of type d cells by D-galactose. The quantity of [acetyl-3H]Con A bound was not proportional to the degree of agglutination. Cells grown in sucrose medium bound more Con A than those grown in glucose medium. After treatment with dextranase, the sucrose-grown cells bound two- to fourfold more Con A. The binding of Con A to the type-specific polysaccharide or to teichoic acid could not be determined by the use of specific antibody due to the binding of Con A to the antibody globulin on the cell surface. Con A bound to S. mutans cells did not inhibit the activity of cell-bound glucosyltransferase, glucan synthesis, and in vitro adherence. Bound Con A also did not inhibit the ability of heat-treated cells to bind glucosyltransferase, synthesize glucan, and produce in vitro adherence.

Agglutination↗
PubMed1976

Chemical and immunological properties of the type f polysaccharide antigen of Streptococcus mutans.

The type-specific cell wall polysaccharide antigen was extracted, purified, and characterized from type f Streptococcus mutans strain OMZ175 and MT557. The antigen was extracted from lyophilized cells with 5% trichloroacetic acid at 85 C for 15 min or saline at 120 C for 30 min. The trichloroacetic acid antigen was chromatographically separated into three antigenic fractions on a diethylaminoethyl-Sephadex A-25 column. Antigen 1 (Ag1P), which was specific for type f antiserum, was further purified by passing through carboxymethyl-Sephadex C-25 and Sephadex G-200 columns. It was a polysaccharide composed of 49% rhamnose and 47% glucose. No reaction was obtained with anti-polyglycerophosphate (PGP) serum. Antigen 2 was reactive with both type f and PGP antisera and contained significant amounts of protein and phosphorus. Antigen 3 was reactive only with PGP antiserum and had no type specificity. The polysaccharide antigen gave a single precipitin band against type-specific antiserum on immunodiffusion and immunoelectrophoresis. The presence of alpha-1,6-glucosidic linkages was indicated by a 90% inhibition of the precipitin reaction by isomaltose and alpha-methyl-D-glucopyranoside, adsorption to and release from a concanavalin A-Sepharose column, and reaction with an S. mutans (type e) glucan antiserum. This antiserum was used to show that the type f polysaccharide antigen did not contain free glucan. An analysis of the antigen released from the antigen-glucan antiserum complex showed the presence of rhamnose and glucose. This released antigen also reacted with an f antiserum, which did not react with commercial dextran. The results show that the type f polysaccharide antigen is the first of those S. mutans type-specific polysaccharides identified to be immunologically related to an S. mutans glucan.

Antigens, Bacterial↗
PubMed1976

Chemical composition of Streptococcus mutans type c antigen: comparison to type a, b, and d antigens.

Studies of the serotype a, b, and d antigens of S mutans were extended to include the serotype c antigen. Type c antigen was extracted from cells of strain Ingbritt and purified by repeated column chromatography. Two type c antigens fractions were separated by chromatography on DEAE-Sephadex and were designated I and II. On agar gel diffusion, the major components of antigens I and II were serologically identical with the major component of the crude Ingbritt extract. Rhamnose and glucose were present in a 2.4:1 ratio and comprised 98 and 93% of the purified antigens, respectively. The compositions of the c antigens were directly related to the carbohydrate content of the serotype c cell wall. In contrast, purified a, b-II, and d antigens, which are also cell wall polysaccharides contain only trace amounts of rhamnose, a major wall carbohydrate. Studies which used comparative immunoelectrophoresis demonstrated that the purified a, b-I, and d antigens were serologically identical to the antigen preparations that have been used for the immunological classification of these serotypes.

Antigens, Bacterial↗