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

In this assay for immunoreactive human proinsulin (IRPI), it first is separated from plasma by use of an antiserum to human C-peptide. An immunoprecipitate is then formed by using a precipitating antiserum and polyethylene glycol, after which IRPI is dissociated from the antiserum by incubation in warm HCl, pH 2.0. The resulting mixture is assayed for insulin immunoreactivity by a double-antibody tracer-competition method involving incubation for four days with a high-affinity anti-insulin antiserum. Human proinsulin of recombinant-DNA origin is used as the standard. Added C-peptide at supraphysiological concentrations did not interfere with or react in the assay. Human insulin cross reacted by 1.5%. The detection limit for IRPI (2 SD from zero-dose binding) is 3 pmol/L. Proinsulin conversion intermediates are measured nearly as well as intact proinsulin. IRPI concentrations in 10 nondiabetic human subjects averaged 12.0 (SEM 1.6) pmol/L. The ratio of proinsulin to immunoreactive insulin averaged 14.3 (SEM 2.2)%. After intravenous arginine, the increase in proinsulin was less than that of insulin, and it declined more slowly.
 ...
PMID:A sensitive radioimmunoassay for human proinsulin, with sequential use of antisera to C-peptide and insulin. 351 48

The aim of this study was to determine whether mucosal antrectomy, which preserves antropyloric motility, would enhance the antiulcer properties of proximal gastric vagotomy (PGV). Hydrochloric acid and gastrin secretion were studied in five dogs before and after PGV and mucosal antrectomy, while the response to the Mann-Williamson operation (an ulcer-producing operation) was evaluated in four control dogs with intact stomachs, five dogs with PGV alone, and six dogs with PGV plus mucosal antrectomy. Proximal gastric vagotomy and mucosal antrectomy decreased mean +/- SEM basal and pentagastrin-stimulated acid secretion from 4.3 +/- 1.3 to 0.4 +/- 0.3 mEq/hr and from 21 +/- 0.7 to 7.4 +/- 1.8 mEq/hr, respectively (p less than 0.05). Basal plasma gastrin was altered little by the operation (68 +/- 9.7 pg/ml before, 58 +/- 11 pg/ml after; p greater than 0.05) but the 4-hour integrated plasma gastrin response to a 200 gm meat meal decreased from 13 +/- 1.8 to 3.3 +/- 0.7 ng X min/ml (p less than 0.05). Only one of six dogs with mucosal antrectomy and PGV developed peptic ulcer after the Mann-Williamson operation, whereas four of five with PGV alone and three of four controls developed ulcers (p less than 0.05, PGV alone versus PGV and mucosal antrectomy). In conclusion, PGV and mucosal antrectomy decreased acid secretion and postcibal gastrin response and provided greater protection against peptic ulcer than PGV alone.
 ...
PMID:Proximal gastric vagotomy and mucosal antrectomy: effect on gastric acid secretion, plasma gastrin, and experimental ulcerogenesis in the dog. 357 53

The role of hypothermia in the antihypoxic effects of drugs was examined in the present experiments. The effects of environmentally induced hypothermia and drugs were tested by exposing mice to 100% nitrogen gas for 80 sec and counting the number of survivors. In a series of 68 vehicle control groups, the mean of mice surviving the test was 8.6% (SEM = 1.4). Hypothermia induced by lowering the ambient temperature or by isolating mice for a brief period increased the number surviving hypoxia, and the per cent of animals surviving was linearly related to body temperature. When the effects of drugs were compared to that of hypothermia, several drugs were found which protected mice from hypoxia to a greater extent than hypothermia alone. Active substances included the anticonvulsant drugs phenobarbital, phenytoin, carbamazepine and diazepam, but not primidone. Physostigmine and the muscarinic agonist oxotremorine also caused significant protection, while the effects of nicotine could be completely accounted for by hypothermia. Arecoline had a biphasic, time-dependent effect that may be explained by a combination of muscarinic and nicotinic actions. The effects of the muscarinic agonists are centrally mediated, since they could be blocked by low doses of scopolamine HCl, but not by the quaternary analog scopolamine methyl nitrate. Furthermore, the antihypoxic effect of physostigmine was not mimicked by the peripherally acting acetylcholinesterase inhibitor, neostigmine. These results suggest that some drugs do have protective effects against hypoxia which are independent of drug-induced hypothermia and that these effects may be mediated through the CNS.
 ...
PMID:Protection against hypoxia-induced lethality in mice: a comparison of the effects of hypothermia and drugs. 359 68

A pharmacokinetic study with mianserin . HCl was performed in six healthy male subjects. The subjects were treated on different occasions intravenously with a constant-rate infusion of 5 mg mianserin. HCl in 1 h, orally with a single dose of 60 mg as two tablets of 30 mg each and with 60 mg as an oral solution. The wash-out period between treatments was 1 month. Blood samples were taken at predetermined times over a period of 120 h following dosing. The mianserin concentration in the plasma samples was determined and the results were pharmacokinetically analyzed. The intravenous data could be adequately described by a 3-compartment model and the oral data by a 2-compartment model, both with first-order transfer and elimination rate constants. The mean plasma clearance of mianserin was found to be 19 +/- 2 l h-1 (mean +/- SEM), the kinetic volume of distribution 444 +/- 250 l, the steady-state volume of distribution 242 +/- 171 l and the elimination half-life 33 +/- 5 h. The absolute bioavailability in terms of extent of absorption was 22 +/- 3% for the solution and 20 +/- 3% for the tablets. The mean peak level for the solution was 79 +/- 11 ng X ml-1 and for the tablets 54 +/- 5 ng X ml-1; mean peak time for the solution was 1.1 +/- 0.2 h and for the tablets 1.4 +/- 0.2 h. The mean absorption half-life for the solution was 0.43 +/- 0.13 h and for the tablets 0.39 +/- 0.11 h.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Absolute bioavailability of mianserin tablets and solution in healthy humans. 383 Jul 18

The capacity of the gastroduodenal mucosa to maintain integrity when exposed to acid and pepsin may require formation of endogenous prostaglandins (PG). The gastric mucosa is capable of PG biosynthesis, and PGE2 is present in the gastric contents of man. The purpose of this study was to examine if acidification of the human stomach affects the output of PGE2. Gastric perfusion was made with 150 mM HCl in seven healthy subjects pretreated with a histamine-2-receptor blocker (ranitidine). Gastric luminal PGE2 was measured by gas chromatography-mass spectrometry. Basal output of PGE2 was 1.42 +/- 0.24 pmol/min (mean + SEM), which increased to 5.37 +/- 0.91 pmol/min (p less than 0.02) during acid perfusion. Gastric acidification did not cause mucosal damage as judged by luminal DNA. We conclude that PGE2 is synthesized in the gastric mucosa even during nearly complete inhibition of parietal cell secretion. Luminal acid, a likely physiological stimulator of mucosal defense, induces a fivefold increase in PGE2 output from the intact mucosa.
 ...
PMID:Acid instillation increases gastric luminal prostaglandin E2 output in man. 386 36

This paper focuses on the concept that traditional SEM artifacts, encountered in soft biological specimens, may be overcome by improving the physico-chemical properties of these samples rather than by applying sophisticated drying procedures. Emphasis is placed upon fixation strategies minimizing these artifacts and allowing the air drying of various specimens, even those showing very delicate surface microprojections. This attitude is illustrated by a variety of cells and tissues prepared for SEM by both conservative (i.e., critical point drying of samples treated with glutaraldehyde and/or osmium tetroxide) and reformative procedures, i.e., air drying of samples treated with glutaraldehyde, tannic acid, guanidine-HCl, and osmium tetroxide (GTGO-AD). The results clearly indicate that samples which were prepared by the GTGO procedure displayed very well preserved surface features with minimum shrinkage, even after being air dried.
 ...
PMID:Optimum fixation conditions may allow air drying of soft biological specimens with minimum cell shrinkage and maximum preservation of surface features. 393 67

Tolazoline treatment of neonates has been reported since 1965. Dosages increased from pulse doses of 1 to 2 mg/kg to continuous infusions of 10 mg/kg X h before neonatal plasma tolazoline concentrations were measured. We developed a microassay for tolazoline and determined neonatal distribution volume, 1.61 +/- 0.21 L/kg, and disposition rate constant (beta), 0.0027 +/- 0.005 min-1 (mean +/- SEM). Half-life (gamma) ranged from 1.47 to 41.25 (median = 4.43) hours and correlated inversely with urine output (x); y (h) = -0.46 + 7.63/x (mL/kg X h), r = .61, P less than .05. The highest plasma tolazoline concentration in a neonate was 20.3 mg/L. Lethal tolazoline concentrations in lambs ranged from 21.8 to 56.8 mg/L. Initial tolazoline concentrations during infusions and after 1- to 2-mg/kg pulse doses ranged from 0.35 to 2.3 mg/L and PaO2 increased greater than or equal to 15 mm Hg in 64% of 14 treatments. The average neonatal pharmacokinetics predict that each 1 mg of tolazoline HCl per kilogram pulse dose will increase the plasma concentration of tolazoline base by 0.5 mg/L. The plasma concentration should remain constant with infusion dose increments of 0.16 mg of tolazoline HCl per kilogram per hour for every 1.0-mg/kg loading dose. Tolazoline dose requirements for specific patients will vary, especially with renal dysfunction. Reduced tolazoline doses were used to treat two patients, concentrations remained constant, and PaO2 was maintained. Tolazoline doses derived from neonatal kinetics are less than current infusion doses and may avoid high concentrations.
 ...
PMID:Oliguria and tolazoline pharmacokinetics in the newborn. 395 11

The effect of varying doses of cimetidine and omeprazole, on acute gastric mucosal lesions produced by topical aspirin (200 mg/kg; 1 ml/100 g) in 0.175 M HCl or topical sodium taurocholate (40 mM; 1 ml/100 g) in 0.175 M HCl was studied in the pylorus ligated rat. Preliminary studies revealed dose dependent inhibition of acid secretion with both cimetidine and omeprazole. Intraperitoneal cimetidine 50 mg/kg and 100 mg/kg given before topical acidified aspirin reduced mucosal lesions from a control score of 23.7 +/- 3.5 (mean +/- SEM) in which 83% of stomachs contained lesions, to 6.9 +/- 2.2 and 3.5 +/- 2.1 respectively (p less than 0.05), 36% and 27% of stomachs containing lesions. A dose of 250 mg/kg failed to reduce lesion score significantly (17.8 +/- 4.9) and 64% of stomachs contained lesions. Taurocholate-induced lesion score was reduced from a control value of 32.7 +/- 4.3 in which 97% of stomachs contained lesions to 10.8 +/- 3.3 and 15.5 +/- 3.8 by cimetidine 10 mg/kg and 25 mg/kg respectively (p less than 0.05), 62% and 68% of stomachs containing lesions. Cimetidine 50 mg/kg and 100 mg/kg failed to significantly reduce mucosal damage. Intraduodenal omeprazole (1.25 to 50 mumol/kg) given before topical acidified aspirin or taurocholate failed to reduce mucosal lesions, as did intragastric omeprazole 5 mumol/kg and 50 mumol/kg given before acidified aspirin. Cimetidine showed cytoprotective properties over a specific dose range beyond which the effect was lost despite continuing suppression of acid secretion. Omeprazole exhibited no cytoprotective activity.
 ...
PMID:Effect of cimetidine and omeprazole on aspirin- and taurocholate-induced gastric mucosal damage in the rat. 401 41

In order to determine the effects of exercise on the calcium status of selected axial and appendicular bones of mature rats, female Sprague-Dawley rats (8-9 mo.) were divided into three groups including, two months (E2, n = 8) or four months (E4, n = 9) of exercise, and four month sedentary controls (S, n = 10). Exercise consisted of treadmill running for 1 hr/day, 5 days/wk at a speed of 14.1 m/min and 8 degrees elevation. After sacrifice all femurs, tibia/fibula complexes, ribs (T7), and vertebrae (T7) were excised, cleaned, weighed and measured for length and volume. After freeze-drying and bone hydrolysis in 5N HCl, total bone calcium contents and concentrations were determined spectrophotometrically. The acid soluble, appendicular bone calcium contents of the E4 group were significantly greater than S for the femur and tibia respectively: E4 = 159.78 +/- 3.44 mg (mean +/- SEM), 129.46 +/- 4.87 mg; S = 140.03 +/- 5.04 mg, 110.40 +/- 4.71 mg. Bone calcium concentration (mg/g dry bone) also was significantly greater in the tibia/fibulas, ribs and vertebrae of the E4 group than the S group. With respect to other training-induced effects, the oxygen carrying capacity of the blood, as well as the heart and lung DNA and protein concentrations did not change after four months of exercise training. Within four months, moderate exercise can increase the calcium deposition in the bones of mature, female rats.
 ...
PMID:Increased bone calcium following endurance exercise in the mature female rat. 404 48

At the muscle-tendon junction of skeletal muscle fibers the structural interface between muscle cell and connective tissue is amplified by tapering, by indentation, and by surface folding. The precise form taken by the surface folds has been unknown due to a lack of studies on the three-dimensional geometry of the muscle-tendon junction. Analysis of this region by scanning electron microscopy, using conventional preparative techniques, is uninformative because the muscle surface is covered by connective tissue. Removal of the connective tissue from individual murine muscle fibers by incubation of fixed fibers in hot HCl, followed in some instances by treatment with collagenase, permits SEM analysis of the uncovered fiber ends. The muscle fiber end is characterized by surface specializations in the form of anastamotic cylindrical folds. Transmission electron micrographs of cross sections and of serial longitudinal sections of muscle fiber ends confirm that the SEM observations are correct.
 ...
PMID:Three-dimensional structure of the murine muscle-tendon junction. 407 57


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>