Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using a randomized blind cross-over design, the comparative efficacy of clonidine in prolonging tetracaine spinal anaesthesia was studied in six mongrel dogs. Lumbar subarachnoid injections (1 ml) of: tetracaine 4 mg with clonidine 150 micrograms, tetracaine 4 mg with epinephrine 200 micrograms, tetracaine 4 mg, clonidine 150 micrograms, epinephrine 200 micrograms, and five per cent dextrose in H2O (vehicle) were administered randomly to each animal at 5-7 day intervals. Subarachnoid tetracaine produced a motor blockade of 186 +/- 58 (mean +/- SEM) min. Both clonidine and epinephrine produced a similar prolongation of tetracaine motor blockade, 135 per cent (p less than 0.01) and 116 per cent (p less than 0.05) respectively, compared with tetracaine alone. No motor blockade was observed in dogs receiving clonidine, epinephrine or five per cent dextrose in H2O. The addition of clonidine to tetracaine spinal anaesthesia produced a significant increase in duration of sensory blockade, 56 per cent (p less than 0.01) and 107 per cent (p less than 0.01) respectively, when compared to tetracaine with and without epinephrine. Subarachnoid clonidine alone produced a sensory blockade of 76 +/- 17 minutes, while only one animal receiving subarachnoid epinephrine had a sensory blockade (40 minutes). No neurologic deficits were observed in any of the animals. The study concludes that during spinal anaesthesia with tetracaine in dogs, clonidine is as effective as epinephrine in prolonging motor blockade, but is more effective in prolonging sensory blockade.
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PMID:Clonidine prolongs canine tetracaine spinal anaesthesia. 376 67

Mouse fetuses homozygous for the lethal cab (cardiac abnormal) mutation are characterized by pleiotropic effects that lead to immediate postnatal death. Mutant fetuses have only 4% of the normal amount of hepatic glycogen and 39% of the normal cardiac glycogen reserve, coupled with lower specific activities of glycogen synthase and phosphorylase. Analysis with the periodic acid-Schiff reagent histochemical stain demonstrated that cab homozygotes also have reduced amounts of structural polysaccharides. One of the most distinctive mutant phenotypic traits is severe prenatal hypoglycemia, with average (+/-SEM) plasma glucose concentrations of 0.35 +/- 0.14 mM in late fetuses compared to 3.47 +/- 0.69 mM in normal littermates. Compromise of glucose transport from dam to fetus or altered cellular glucose utilization was considered as a possible basis for the low extracellular and intracellular (hepatic) levels of glucose in mutants. Transport of the glucose analogue alpha-methyl[14C]glucoside by the placenta of cab homozygotes is normal. However, metabolism of [14C]glucose by mutant cells yields only 20% of the normal amount of 14CO2. This reduced efficiency of glucose metabolism is correlated with lower ATP concentrations in mutant organs. Aberrant glucose utilization may account for the pleiotropic features of the cab syndrome.
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PMID:Prenatal expression of a lethal genetic defect in carbohydrate metabolism in mice. 385 87

We used fracture-label to establish ultrastructural localization of glycoproteins in cross-fractured nuclei of duodenal columnar and exocrine pancreatic cells. Mannose residues were detected in cell nuclei by labeling freeze-fractured tissues with concanavalin A-horseradish peroxidase X colloidal gold (Con A-HRP X CG) or direct concanavalin A X colloidal gold (Con A X CG); fucose residues were detected with Ulex Europaeus I X colloidal gold (UEA I X CG) markers. Areas of the three main intranuclear compartments (euchromatin, heterochromatin, and nucleolus) exposed by freeze-fracture were determined by automated image analysis. Colloidal gold particles bound to each nuclear subcompartment were counted and the results expressed in number of colloidal gold particles per square micrometer +/- SEM. Duodenal and pancreatic tissues fractured and labeled with Con A-HRP X CG complex or direct Con A X CG conjugates showed that the vast majority of Con A binding sites was confined to euchromatin regions with only sparse labeling of the heterochromatin and nucleolus. UEA I labeling of duodenal columnar cells showed that colloidal gold particles were almost exclusively confined to cross-fractured areas where euchromatin is exposed. Trypsinization of the fractured tissues before labeling with Con A and UEA I abolished 95-100% of the original label. Our results show that, within the nucleoplasm, mannose and fucose are residues of glycoproteins preferentially located within the regions of euchromatin.
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PMID:Preferential association of glycoproteins to the euchromatin regions of cross-fractured nuclei is revealed by fracture-label. 394 91

Concentrations of [14C]2-deoxy-D-glucose ([14C]DG) and of glucose were measured in plasma of arterial and sagittal sinus venous blood from awake Fischer-344 rats at 3, 12, and 24 months of age, during continuous intravenous infusion of [14C]DG and after a steady-state arterial plasma concentration of [14C]DG was reached. Brain extraction, i.e., the difference between arterial and venous plasma concentrations divided by the arterial plasma concentration, was calculated for both [14C]DG and glucose. Because exchange of both substances between rat plasma and erythrocytes is slow, the ratio of the brain extraction of [14C]DG to that of glucose is identical to the lumped constant in the deoxyglucose procedure of Sokoloff et al. [J. Neurochem. 28, 897-916. (1977)]. This ratio equaled 0.502 +/- 0.015 (SEM) at 3 months, 0.456 +/- 0.007 at 12 months, and 0.418 +/- 0.006 at 24 months of age (n = 15); the means differed significantly from each other (p less than 0.05). The results indicate that the lumped constant declines between 3 and 24 months of age in awake rats, and suggest that many reported age reductions in regional cerebral glucose utilization, of 15-25%, are artifactual.
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PMID:The lumped constant in the deoxyglucose procedure declines with age in Fischer-344 rats. 395 Jun 13

Enzymatic assays were modified to permit sensitive and highly reproducible simultaneous measurements of D-mannose and D-glucose in biological fluids during weeks 34-40 of human pregnancy. Plasma mannose and glucose averaged 9.8 +/- 0.4 (+/- SEM) and 790 +/- 16 micrograms/ml, respectively, after an overnight fast in pregnant women (n = 22) with normal carbohydrate metabolism. Significantly higher plasma mannose levels were found, despite only minor increases in plasma glucose, in pregnant women with relatively well controlled diabetes mellitus after an overnight fast (16.9 +/- 0.6 micrograms/ml mannose; 883 +/- 29 micrograms/ml glucose; n = 31) or 3-4 h after breakfast (15.7 +/- 1.2 micrograms/ml mannose; 1159 +/- 101 micrograms/ml glucose; n = 19). Plasma mannose correlated significantly with plasma glucose in the women with diabetes mellitus, particularly after an overnight fast. Samples of amniotic fluid were also obtained from the gravida with diabetes mellitus to provide some index of simultaneous relationships in utero. Amniotic fluid mannose and glucose averaged 5.9 +/- 0.4 and 302 +/- 24 micrograms/ml, respectively, after an overnight fast and 6.7 +/- 1.3 and 459 +/- 84 micrograms/ml 3-4 h after breakfast. In amniotic fluid, as in plasma, the concurrent levels of mannose and glucose conformed to relatively fixed relationships. Thus, both fetus and mother appear to be exposed to readily demonstrable amounts of mannose during late gestation and the absolute as well as relative abundance of mannose may be increased coincident with faulty maternal glucoregulation. However, since mannose did not exceed 3% of the concurrent concentration of glucose in any instance, it does not seem likely that endogenous levels of circulating mannose can modify glucose utilization appreciably by competing with glucose for phosphorylation via hexokinase and subsequent intracellular processing.
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PMID:Relationships between glucose and mannose during late gestation in normal pregnancy and pregnancy complicated by diabetes mellitus: concurrent concentrations in maternal plasma and amniotic fluid. 395 33

The effects of severe hypoxemia on gastrointestinal (GI) blood flow and gastric emptying were studied in nine 2- to 4-day-old piglets which were mechanically ventilated while receiving nitrous oxide anesthesia. Each animal was studied during a control period of oxygenation (PaO2 91 +/- 8 torr), 35 min of hypoxemia (PaO2 29 +/- 1 torr), and a recovery period (PaO2 90 +/- 5 torr) (mean +/- SEM). During each study period, the animal received a 10% dextrose test meal with phenol red marker (22 ml/kg), gastric residual volumes were determined at 10-min intervals over 30-min study periods using a dye dilution double sampling technique, and GI blood flow (radionuclide-labeled microspheres), O2 delivery, O2 extraction, and O2 consumption were measured at the end of the 30-min period. Hypoxemia resulted in decreased blood flow to the following GI organs: stomach, jejunal and ileal mucosa-submucosa, and colon decreased 62, 31, and 35%, respectively (p less than 0.05). Jejunal and ileal muscularis blood flow remained unchanged. Oxygen delivery and consumption by GI tract decreased 79 and 58%, respectively; whereas oxygen extraction of GI tract increased 115%. Values returned toward baseline levels during the recovery period. The hypoxemic gastric emptying pattern showed significantly greater gastric residuals at 20 min compared to the 10-min value (p less than 0.05). This pattern was different than that observed during control and recovery periods. We conclude that severe hypoxemia results in decreased GI blood flow, tissue oxygenation, and an altered gastric emptying pattern. These observations may have clinical significance for feeding infants following an hypoxemic episode.
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PMID:Effects of hypoxemia on gastrointestinal blood flow and gastric emptying in the newborn piglet. 400 Jul 73

Optimal function of transfused granulocytes (PMNs) requires adequate glycogen metabolism. Previous studies in our laboratory suggested that stored PMNs had decreased glycogen. We report here the glycogen content and chemotaxis of stored PMNs, and the ability of fresh and stored PMNs to use glycogen as the fuel source for chemotaxis. PMNs were prepared from 8 fresh units of blood drawn into citrate-phosphate-dextrose-adenine, suspended at 2 or 8 X 10(7) PMN per ml in autologous plasma with or without 15 mM sodium bicarbonate, and stored at 22 to 24 degrees C in transfer packs for 48 hours. Glycogen was measured on resting PMNs, and after challenge with opsonized zymosan and F-Met-Leu-Phe (FMLP). The chemotaxis of fresh and stored PMNs was measured in the presence or absence of extracellular glucose. Fresh PMNs contained 10.3 +/- 0.5 (mean +/- SEM) micrograms of glycogen per 10(6) PMN. Glycogen decreased by 4.2 +/- 0.9 micrograms per 10(6) PMN after challenge with opsonized zymosan and by 1.1 +/- 0.6 micrograms per 10(6) PMN after FMLP. After 48 hours of storage, neutrophil glycogen increased by 18 percent, except in units stored at a concentration of PMN of 8 X 10(7) per ml without sodium bicarbonate. In PMNs from these units stored without bicarbonate, glycogen decreased by 9 percent (p less than .05), and there was a 19 and 55 percent decrease in the ability of PMN from these units to metabolize glycogen after exposure to opsonized zymosan and FMLP, respectively (p less than 0.05). In addition, in PMNs from units stored at a concentration of PMN of 8 X 10(7) per ml without bicarbonate, there was a 47 and 70 percent decrease in chemotaxis at 24 and 48 hours, respectively (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Glycogen metabolism in stored granulocytes. 400 9

In vivo studies indicate that the extent of phosphate (Pi) reabsorption differs in proximal tubules of superficial (SC) and juxtamedullary (JM) nephrons. Since Na-gradient (Nao greater than Nai) dependent uptake of Pi by the luminal brushborder membrane (BBM) may be the rate-determining step in proximal tubular reabsorption, we studied this transport system in brushborder membrane vesicles (BBMV) prepared from SC and JM renal cortex of dogs fed either a low phosphorus diet (LPD, 0.07% Pi) or high phosphorus diet (HPD, 1.2% Pi). In the initial uphill phase (that is, "overshoot"), the rate of Na-gradient dependent uptake of Pi was significantly greater [delta + 35%] in BBMV from the SC cortex (BBMV-SC) than in BBMV from the JM cortex (BBMV-JM) of the dogs fed LPD. Higher Na-dependent Pi uptake was due to significantly (P less than 0.05) higher apparent Vmax (mean +/- SEM, nmoles Pi/0.5 min/mg protein) for Pi in BBMV-SC (7.5 +/- 1.57) compared with Vmax in BBMV-JM (6.05 +/- 1.74). Higher transport of Pi in BBMV-SC compared with BBMV-JM of dogs fed LPD was a difference relatively specific for the Na-dependent Pi uptake system; Na+ independent uptake of Pi and Na-dependent uptake of D-glucose were lower in BBMV-SC than in BBMV-JM. The size of BBMV or rate of Na+ uptake did not differ between BBMV-SC and BBMV-JM. The Na-gradient dependent uptake of Pi was no different between BBMV-SC and BBMV-JM from dogs stabilized on HPD.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Phosphate transport by brushborder membranes from superficial and juxtamedullary cortex. 402 18

Following intravenous administration of 500 mg/kg b.wt. galactose, Galactose Elimination Capacity (GEC, mg/min/kg) was determined in 24 subjects with chronic non-cirrhotic liver disease (CLD), 33 with liver cirrhosis and 11 controls. GEC was significantly (P less than 0.01) reduced in both CLD and cirrhosis. A statistically significant difference (P less than 0.01) was present between these two groups. Following the plasma disappearance curve at concentrations below 1.25 mmol/l, at which the extraction coefficient is assumed to be equal to one, the "Efficient Hepatic Blood Flow" (EHBF, ml/min) was determined in 11 consecutive cirrhosis patients, seven patients with CLD and 11 controls. EHBF was normal or slightly reduced in CLD as compared to controls (1046 +/- 216 vs. 1471 +/- 156 ml/min, mean +/- SEM, n.s.) whereas it was markedly reduced in cirrhosis (846 +/- 96 ml/min, mean +/- SEM, p less than 0.001). Interestingly, a significant linear correlation (r = 0.757, p less than 0.001) was present between EHBF and the plasma clearance of sulfobromophthalein. No correlation was present, on the other hand, between the value of GEC and that of EHBF. These data indicate that after a single intravenous injection of galactose, the hepatic blood flow passing through the enzymatically active parts of the liver (i.e. excluding shunts) can be measured.
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PMID:Estimation of the hepatic blood "flow" by galactose plasma clearance in patients with liver disease. 404 51

In 6 hypertensive patients with terminal renal failure maintained on hemodialysis, the effects of 'salt subtraction' and of sequential ultrafiltrating were evaluated. Following each of 3 weekly hemodialysis sessions, salt subtraction was carried out by ultrafiltrating 1 liter and simultaneously infusing an equal volume of 5% dextrose. This resulted in a net sodium loss without hypovolemia. After a 2-week period of this procedure, the blood pressure prior to dialysis was lower (156/76 +/- 12/5 mm Hg) than after a comparable number of sequential ultrafiltration sessions (181/88 +/- 10/6 mm Hg; mean +/- SEM). This difference was not statistically significant. At the same time, body weight was comparable at 64.4 +/- 3 and 64.7 +/- 4 kg, respectively. Neither plasma renin activity nor plasma catecholamines responded with a clear increase to either procedure. The limited effect on blood pressure and the renin system of a marked sodium removal during salt subtraction suggests that sodium must still be present in excess in these patients. The procedure of salt subtraction appears safe and subjectively well tolerated, but it can probably not be used as the sole means of decreasing total body sodium without associating dietary measures to reduce sodium intake.
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PMID:Salt subtraction in patients on maintenance hemodialysis. Efficacy and limitations. 405 Aug 88


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