Does intrinsic LES tone increase as an adaptive response to increased intraabdominal pressure?
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Abdomen↗
Biomedical subjects
S Cohen
Publications and source records attributed to S Cohen.
Controlled trial of medical therapy for active upper gastrointestinal bleeding and prevention of rebleeding.
UNLABELLED: This multicentered, placebo-controlled trial evaluated the efficacy of medical therapy to stop bleeding in 285 patients with active upper gastrointestinal bleeding (bleeding phase) and 194 patients who had ceased gastrointestinal bleeding and in whom therapy was instituted to prevent rebleeding during the same hospitalization (prevention phase). Patients in the bleeding phase were given cimetidine (300 mg every six hours) or intravenous placebo. There was no significant overall difference between intravenous cimetidine (71 percent) and placebo (77 percent) in stopping acute upper gastrointestinal bleeding. There was also no significant difference noted between intravenous cimetidine and placebo when specific bleeding lesions were evaluated. Once gastrointestinal bleeding had stopped, recurrence of bleeding while receiving prevention therapy (cimetidine tablets 300 mg one three times a day and at bedtime, or Mylanta II liquid 30 ml every hour, or cimetidine plus hourly antacids, or placebo) was evaluated in 194 of the patients in the bleeding phase. Twenty-four percent (12 of 51 patients) rebled while receiving cimetidine, 13 percent (five of 39 patients) rebled while receiving hourly antacids, 11 percent (six of 54 patients) rebled while receiving cimetidine plus hourly antacids, and 26 percent (13 of 50 patients) rebled while receiving placebo. None of these prevention regimens reached statistical significance (p = 0.13). Evaluation of specific bleeding lesions within this group also failed to show any significant value of prevention therapy. IN CONCLUSION: (1) intravenous cimetidine offers no advantage over placebo in stopping active upper gastrointestinal bleeding; (2) the occurrence of rebleeding during the same hospitalization does not appear to be significantly affected by any of the medical regimens used for prevention. These findings would suggest that the cessation of active bleeding and the prevention of recurrent upper gastrointestinal bleeding during a single hospitalization appear to be unaffected by therapy directed at acid neutralization or reduction.
Adult↗
Acute allergic reaction to eugenol.
Eugenol has been widely used in the dental profession. It is an effective material that is incorporated into many dental products. Contact dermatitis due to this chemical is not unusual. However, true serious allergic reactions are extremely rare. This paper reports on such a case. Careful assessment of patients and of their dental and medical history is necessary to avoid disaster in the office.
Dental Materials↗
Determinants of blood pressure in Jerusalem schoolchildren.
In 1982, 113 first- and second-graders attending an elementary school in West Jerusalem had their blood pressure (BP), height, weight, and resting pulse measured. Three successive BP readings were taken. The mean of the second and third readings was used for data analysis. Mean systolic blood pressure (SBP) was 98.30 +/- 8.51 mm Hg and mean diastolic blood pressure (DBP) was 67.63 +/- 6.85 mm Hg. An analysis of covariance was performed in order to determine the contribution of each independent variable (height, weight-for-height, sex, age, and resting pulse) to the variance in BP, while adjusting for all other independent variables. Height, weight-for-height, and resting pulse were all found to be significantly associated with both SBP and DBP. Children in the upper quartile of weight-for-height had a mean adjusted SBP that was 10.2 mm Hg higher than those in the lower quartile and a mean adjusted DBP that was 7.9 mm Hg higher. Children in the upper quartile of height (for age) had mean adjusted SBP and DBP that were 6.1 and 4.7 mm Hg higher, respectively, than those of children in the lower quartile. Sex and age showed no significant association with SBP. The associations between DBP and both sex and age were not statistically significant (P less than 0.10), but there was a trend for girls and older children to have a slightly higher DBP. In a subsample of 93 children who had both resting pulse and recovery index measured (using the Modified Harvard Step Test for children).(ABSTRACT TRUNCATED AT 250 WORDS)
Age Factors↗
Biosynthesis of a putative protective Plasmodium knowlesi merozoite antigen.
A putative protective Plasmodium knowlesi antigen, recognized by two monoclonal antibodies which prevent invasion of erythrocytes by merozoites in vitro, is synthesised only by schizonts with 7 or more nuclei, during the last 1.5-2 h of the 24 h erythrocytic cycle of parasite development. The 66 000 MW antigen, which constitutes a minor parasite protein, is processed at the time of schizont rupture and merozoite release, to give rise to two smaller molecules of 44 000 and 42 000 MW. The 44 000 and 42 000 MW antigens and traces of the 66 000 MW antigen are present on the surface of isolated merozoites and the smaller antigens are readily shed. The antigens which are shed are soluble in culture medium and are not readily degraded further. None of the molecules can be detected in newly invaded ring stage parasites, indicating that they are either excluded when the merozoite invades, or if internalised, they rapidly undergo further structural alteration since newly parasitised red cells no longer contain epitopes which react with the inhibitory monoclonal antibodies. This antigen is distinct from other putative protective antigens described in bloodstage malaria parasites.
Animals↗
The Fab fragments of monoclonal IgG to a merozoite surface antigen inhibit Plasmodium knowlesi invasion of erythrocytes.
Two rat monoclonal antibodies (both IgG2a isotype and having closely related specificities) and a pool of rhesus immune IgG, all of which inhibit Plasmodium knowlesi merozoite invasion of rhesus erythrocytes, have been studied before and after proteolytic digestion. The F(ab')2 and Fab fragments of both rat monoclonal antibodies show considerably enhanced inhibition of merozoite invasion as compared with the intact IgG. Inhibition by monovalent fragments indicates that these antibodies are not dependent upon merozoite agglutination and may act by blocking merozoite attachment to the specific red cell receptor. The fact that the inhibitory activities of F(ab')2 and Fab are equally enhanced on a weight basis, as compared with IgG, suggests that the removal of Fc may reduce electrostatic repulsion between antibody and merozoite surface, both of which are negatively charged at neutral pH. By contrast, papain digestion of polyclonal IgG derived from an immunised rhesus pool markedly reduces its inhibitory activity. This suggests that much of the inhibition mediated by polyclonal IgG results from merozoite agglutination and that the specificity of the rat inhibitory monoclonal antibodies is poorly represented in the immune pool. The P. knowlesi antigen reactive with the inhibitory monoclonal antibodies is known to be synthesized as a minor 66 kDa polypeptide during the last 1.5 h. of schizont development and is processed to smaller products (44 and 42 kDa) present on the merozoite surface. The present results suggest that this antigen may have particular interest as a vaccine against P. knowlesi malaria.
Animals↗
Cytoplasmic pH regulation in thymic lymphocytes by an amiloride-sensitive Na+/H+ antiport.
The mechanisms underlying cytoplasmic pH (pHi) regulation in rat thymic lymphocytes were studied using trapped fluorescein derivatives as pHi indicators. Cells that were acid-loaded with nigericin in choline+ media recovered normal pHi upon addition of extracellular Na+ (Nao+). The cytoplasmic alkalinization was accompanied by medium acidification and an increase in cellular Na+ content and was probably mediated by a Nao+/Hi+ antiport. At normal [Na+]i, Nao+/Hi+ exchange was undetectable at pHi greater than or equal to 6.9 but was markedly stimulated by internal acidification. Absolute rates of H+ efflux could be calculated from the Nao+-induced delta pHi using a buffering capacity of 25 mmol X liter-1 X pH-1, measured by titration of intact cells with NH4+. At pHi = 6.3, pHo = 7.2, and [Na+]o = 140 mM, H+ extrusion reached 10 mmol X liter-1 X min-1. Nao+/Hi+ exchange was stimulated by internal Na+ depletion and inhibited by lowering pHo and by addition of amiloride (apparent Ki = 2.5 microM). Inhibition by amiloride was competitive with respect to Nao+. Hi+ could also exchange for Lio+, but not for K+, Rb+, Cs+, or choline+. Nao+/Hi+ countertransport has an apparent 1:1 stoichiometry and is electrically silent. However, a small secondary hyperpolarization follows recovery from acid-loading in Na+ media. This hyperpolarization is amiloride- and ouabain-sensitive and probably reflects activation of the electrogenic Na+-K+ pump. At normal Nai+ values, the Nao+/Hi+ antiport of thymocytes is ideally suited for the regulation of pHi. The system can also restore [Na+]i in Na+-depleted cells. In this instance the exchanger, in combination with the considerable cytoplasmic buffering power, will operate as a [Na+]i-regulatory mechanism.
Amiloride↗
Glucose-induced hemolysis of spheric red blood cells in hereditary spherocytosis: new aspects of the autohemolysis test.
Increased autohemolysis with a partial protecting effect of added glucose is a common finding in hereditary spherocytosis (HS). For unknown reasons, in some rare cases, glucose fails to prevent the increased autohemolysis (Type II autohemolysis). The authors investigated the autohemolysis of such a patient and found that glucose actually induced the hemolysis prior to energy depletion. Old erythrocytes proved to be more fragile in the presence of D-glucose than did young ones. Other D-hexoses reacted similarly to D-glucose, while L-glucose did not. After being splenectomized, the patient's red blood cells' specific sensitivity to D-hexoses disappeared unless a 24-hour preincubation of his whole blood was performed. Other HS blood samples also became fragile in the presence of D-glucose if a 24-hour preincubation at 37 degrees C was made. Normal blood samples preheated to 50 degrees C or normal washed red blood cells in hypotonic conditions also showed a glucose-induced hemolysis. The authors assume that during the routine autohemolysis test, the accumulation of the hexose is followed by volume expansion and results in hemolysis of those cells with extremely low surface area-to-volume ratio.
Child↗
Fetal-neonatal status following caesarean section for fetal distress.
Fetal biochemical and neonatal clinical data were compiled in 126 emergency Caesarean sections performed for fetal distress. The choice of anaesthetic technique was determined by the wishes of the mother. General anaesthesia was administered to 71 parturients and regional analgesia to 55 (subarachnoid block 33, extension of extradural block 22). The aetiologies of fetal distress and the skin incision-delivery and uterine incision-delivery intervals were not significantly different between the two anaesthesia groups. Umbilical artery blood pH values were higher than the last scalp capillary blood pH values in 63% of the general anaesthesia and in 80% of the regional analgesia cases. Umbilical vein and artery blood-gas and pH data were similar in the two anaesthesia groups, but 1-min Apgar scores were significantly better following regional analgesia. Despite the presence of fetal distress, subarachnoid blockade was a most suitable method of anaesthesia in experienced hands.
Anesthesia, Conduction↗
Monoclonal antibodies in parasitic infectious diseases.
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Animals↗
Daytime alertness in relation to mood, performance, and nocturnal sleep in chronic insomniacs and noncomplaining sleepers.
Nocturnal sleep was recorded prior to daytime testing that included the Multiple Sleep Latency Test, profile of mood states, card sorting, and Stanford Sleepiness Scale in 138 volunteers with the complaint of chronic insomnia and 89 noncomplaining sleepers ("normals"). In both groups daytime sleep tendency had no significant linear correlation either with any Minnesota Multiphasic Personality Inventory scale or with tension/anxiety and other moods assessed in the morning. In normals, speed of card sorting but not subjective sleepiness tended to correlate with sleep tendency. Given that physiological sleepiness is the most predictable consequence of sleep deprivation in normals, it is particularly interesting that 14% of the insomniac group are chronic insomniacs with no measurable daytime sleep tendency. Despite this lack of sleep tendency during the day, their nocturnal sleep was just as poor as insomniacs with greater daytime sleep tendency. The lack of daytime sleepiness seen in this subgroup may reflect a basic pathophysiological aspect of their insomnia.
Adult↗
Adverse effects of spinal anesthesia in a patient with idiopathic hypertrophic subaortic stenosis.
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Aged↗
Immunological detection of Plasmodium knowlesi antigens after electrophoretic transfer from SDS-polyacrylamide gels to diazophenylthioether paper.
Freeze-thawed extracts of mature schizonts of Plasmodium knowlesi (strain W1) were electrophoresed in sodium dodecylsulphate (SDS) polyacrylamide gels, then transferred electrophoretically to diazophenylthioether paper. The transferred antigen was probed using a purified polyvalent, polyclonal immune serum pool isolated from rhesus monkeys (Macaca mulatta). This method for identifying parasite antigens was compared with immunoabsorption, using parasites which had been metabolically labelled in vitro with 35S-methionine. The methods showed general correspondence but some antigens failed to react after transfer because of loss of antigenicity during SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Some antigens were observed preferentially after the transfer procedure, possibly because of their failure to elute from the immunoabsorbant or because they may have a low methionine content. The transfer method failed to reveal the antigen reactivity of three out of four monoclonal antibodies tested, apparently because the epitopes involved were inactivated by SDS. During P. knowlesi infection in the resistant kra monkey (Macaca fascicularis) the transfer method showed the presence by day 10 of antibodies against two components having an apparent molecular weight by SDS-PAGE similar to those of putative protective antigens described in other studies using monoclonal antibodies.
Animals↗
The molal volumes of atropine and hyoscine in relation to their respective potencies.
The partial molal volumes, V2, at infinite dilution of atropine and hyoscine were determined in each of eight different solvents having cohesive energy densities in the range 64 to 144 cal cm-3. V2 for hyoscine in a given solvent was invariably and significantly smaller than that of atropine in the same solvent. The difference being 1.58 cm3 mol-1 in the least polar solvent (n-propylbenzene) and 4.29 cm3 mol-1 in the most polar one (acetonitrile) in the series studied. It is proposed that the lower affinity of atropine relative to that of hyoscine for the muscarinic cholinoceptor could be accounted for by the relative increase in enthalpy in the adsorption of atropine to the receptor with respect to the same process with hyoscine.
Atropine↗
Autocides produced by Myxococcus xanthus.
Ethanol extracts of Myxococcus xanthus contained several substances, referred to as autocides, which were bactericidal to the producing strain but showed no activity against other bacteria. The autocides were produced by growing cells and remained largely cell bound throughout the growth cycle; ca. 5% of the autocidal activity was found in the supernatant fluid at the time cell lysis began. The autocides were separated by sequential-column and thin-layer chromatography into five active fractions (AM I through AM V). Each of the fractions was at least 20 times more active against M. xanthus than against the other gram-negative or gram-positive bacteria tested. AM I, AM IV, and AM V were inactive against yeasts, whereas a mixture of fractions AM II and AM III was active against Rhodotorula sp. At low concentrations, AM I reversibly inhibited the growth of M. xanthus; at higher concentrations of AM I, the cells lysed within 1 h. The lowest concentration of AM IV that showed any activity caused rapid cell death and lysis. The mode of action of the major autocide, AM V, was different from that of AM I and AM IV. During the initial 2 h of treatment, the viable count of M. xanthus cells remained constant; during the next few hours killing occurred without lysis; within 24 h lysis was complete. The autocidal activity of each of the fractions was expressed when the cells were suspended in buffer, as well as in growth medium. The possible role of autocides in developmental lysis of M. xanthus is discussed.
Anti-Bacterial Agents↗
A clinicopathological case of retinopathy of prematurity (ROP) treated by peripheral cryopexy.
A baby born at 25 weeks gestation with a birth weight of 800 g who suffered from severe respiratory distress syndrome with metabolic acidosis is described. Active retinopathy of prematurity, stages II and III, was found in the right eye at the age of 1 month and in the left eye a month later. Both eyes were treated by peripheral cryopexy. The pathological examination showed that cryopexy was effective in preventing progression of the retinopathy to cause severe cicatrisation.
Cryosurgery↗
Cryotreatment of retinopathy of prematurity.
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Cryosurgery↗