Uprighting partially impacted molars.
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Humans↗
Biomedical subjects
R Lang
Publications and source records attributed to R Lang.
The relative antihypertensive potency of propranolol, oxprenolol, atenolol, and metoprolol given once daily. A double-blind, crossover, placebo-controlled study in ambulatory patients.
The antihypertensive effect of four beta-blocking agents given once daily was compared with that of placebo in a prospective, crossover, double-blind study of 150 patients. The preparations tested were slow-release propranolol hydrochloride, 160 mg, atenolol, 100 mg, slow-release oxprenolol hydrochloride, 160 mg, and metoprolol, 200 mg. Propranolol and atenolol produced a significant decline in lying, standing, and postexercise blood pressure and pulse rate values. The effects of oxprenolol and metoprolol were not significantly different from that of placebo.
Adult↗
[Hairy cell leukemia in Israel].
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Actuarial Analysis↗
Refractory ascites treated by a peritoneovenous shunt in a patient with congestive heart failure.
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Ascites↗
[Imbalances of neutral plasma amino acids as a pathogenetic factor in anorexia].
Studies in anorectic tumor-bearing rats indicate that anorexia is correlated to imbalances of neutral amino acids in blood and CNS. Consequently plasma amino acids of patients with neoplastic and non-neoplastic internal diseases were studied during phases of anorexia; special regard was given to the precursors of dopamine and serotonin. Anorectic patients were compared to non-anorectic patients with neoplasia. During anorexia, plasma levels of valine and leucine and hence the ratio of the molar concentrations of Val + Leu + Ile/Phe + Tyr were significantly decreased in each anorectic patient as compared to non-anorectic patients whose ratios were always within the normal ranges. As aromatic and branched-chain amino acids compete for penetration of the blood brain barrier, the decrease of the amino acid ratio may induce a raised flux of phenylalanine and tyrosine into the CNS which results in an increased activation of dopaminergic neurons--known to cause anorexia.
Amino Acids, Branched-Chain↗
[Sympathetic activity in terminal renal failure and kidney transplants].
Blood pressure as well as noradrenaline, creatinine and electrolytes in blood and urine were compared in normal controls (n = 25), patients with chronic renal failure (n = 39), patients with continuous ambulatory peritoneal dialysis (CAPD) (n = 28) and haemodialysis patients before and after renal transplantation (n = 63). The average blood pressures of the control group and the CAPD patients were lower than those of the renal failure patients without and with haemodialysis. After renal transplantation elevated blood pressure normalised in 18% within the following 6 months. In all groups of patients with renal failure the mean noradrenaline plasma concentration was increased more than three-fold of normal values: 1,470 pg/ml in patients with chronic renal failure, 1,366 pg/ml in CAPD patients and 1,284 pg/ml in patients with haemodialysis. No correlation was found between these elevated noradrenaline plasma levels and blood pressure. However, there was a significant correlation between noradrenaline excretion and sodium excretion. Compared to the controls, the urine excretion of noradrenaline was significantly lower in patients with chronic renal failure and almost zero in patients with dialysis treatment. Two days after renal transplantation the mean noradrenaline urine excretion increased to 15.7 +/- 1.8 micrograms/day and 4 days after transplantation the noradrenaline plasma concentration decreased to 592 +/- 155 pg/ml. Nine months after renal transplantation the creatinine clearance was 76 ml/min and the mean noradrenaline plasma concentration 438 +/- 153 pg/ml. It is concluded that in chronic renal failure the level of noradrenaline plasma concentration is dependent on renal function.
Blood Pressure↗
Evidence for disordered control of 1,25-dihydroxyvitamin D production in absorptive hypercalciuria.
In previous studies, we observed increases in the circulating concentration and production rate of 1,25-dihydroxyvitamin D (1,25-(OH)2D) in a large majority of patients with the syndrome of absorptive hypercalciuria. In the present study, the hypothesis that 1,25-(OD)2D production might be relatively autonomous in this syndrome was tested by fashioning a suppression test in which patients were challenged with a short-term increase in dietary calcium intake. We found that contrary to our hypothesis, the circulating concentration of 1,25-(OH)2D was remarkably sensitive to calcium intake in 15 patients with absorptive hypercalciuria (mean decrease, from 74 to 49 pg per milliliter, P less than 0.001). When this challenge was prolonged for two weeks, however, patients with absorptive hypercalciuria had evidence of an apparent "escape" phenomenon, in which the circulating concentration of 1,25-(OH)2D rebounded toward its initial level and the renal tubular phosphate threshold fell markedly. These findings provide evidence for disordered control of renal phosphate handling and 1,25-(OH)2D production in absorptive hypercalciuria and suggest a linked rather than a cause-and-effect relation between these two abnormalities.
Adult↗
Distribution of neuropeptide immunoreactive nerve terminals within the subnuclei of the nucleus of the tractus solitarius of the rat.
The location of substance P, enkephalin and somatostatin (SRIF), and neurophysin II immunoreactive nerve terminals and preterminal processes in the caudal part of the nucleus of the tractus solitarius (nTS) was examined by the indirect immunofluorescence method for immunocytochemistry combined with cytoarchitectural identification of nuclear subgroups in the same tissue. In 22 Sprague-Dawley rats we examined 14-micrometers-thick serial sections of the dorsal medulla at levels from 1 mm caudal to 2 mm rostral to the obex. These sections were incubated with substance P, enkephalin, somatostatin, and neurophysin II antisera. All four peptides were examined in each case and five typical levels (two caudal and three rostral to the obex) were selected for comparison of terminal distribution between peptides. All sections were photographed under the fluorescence microscope and then counter-stained with cresyl violet. This method of analysis revealed distinct patterns of neuropeptide immunoreactivity in the subnuclei of the nTS that varied according to the level of the section. The nTS is responsible for integrating respiratory, cardiovascular (baroreceptor and cardiac), and gastrointestinal functions. The ventrolateral subnucleus (Vl)nTS, ventral subnucleus (v)nTS, interstitial subnucleus (ni)nTS, and intermediate subnucleus (nI)nTS are the major respiratory subnuclei with vlnTS and vnTS prominently associated with pulmonary afferents, ni associated with laryngeal afferents, and nI with tracheal afferents. The vlnTS, vnTS, and ni showed a moderate density of somatostatin-positive nerve terminals, scattered substance P and enkephalin immunoreactivity, and no neurophysin II-positive terminals. The nI showed moderate density of substance P immunoreactive nerve terminals. The subnuclei of the nTS receiving baroreceptor and chemoreceptor afferents--dorsolateral and dorsal (dl and d) subnuclei of nTS--showed scattered substance P immunoreactive nerve terminals. The commissural nucleus of nTS (ncom), which receives most of the cardiac afferents, showed a moderate density of enkephalin-positive immunoreactive nerve terminals. The medial subnucleus (m)nTS at levels rostral to the obex, the primary site for the termination of gastrointestinal afferents, showed substance P immunoreactivity in moderate amounts and weak immunoreactivity for all the other neuropeptides. An important result of these experiments was the observation that regions of the medulla adjacent to the nTS, i.e., the ventral parasolitarius region (vPSR), dorsal (d)PSR, and the periventricular region (PVR) showed the densest amounts of immunoreactive nerve terminals.(ABSTRACT TRUNCATED AT 400 WORDS)
Afferent Pathways↗
Comparison of the effect of nucleotides on phosphate transport in renal brush border membrane vesicles and intact proximal tubules.
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Adenine Nucleotides↗
The mammalian spot test and its use for testing of mutagenic and carcinogenic potential: experience with the pesticide chlordimeform, its principal metabolites and the drug lisuride hydrogen maleate.
The mammalian spot test has recently been demonstrated to be a promising method for the detection of somatic mutations induced by chemicals and is at present under validation as an in vivo screening test for carcinogenic potential. The pesticide chlordimeform, its principal metabolites N-formyl-4-chloro-o-toluidine and 4-chloro-o-toluidine, and the drug lisuride hydrogen maleate, as well as the known mutagens ethyl methanesulfonate (EMS) and N-ethyl-N-nitrosourea (ENU) were tested in the mammalian spot test. Female C57BL/6J mice were mated to T-stock males and treated by gavage with maximal tolerated doses of the test compounds, or by intraperitoneal injection with EMS and ENU at days 8, 9 and 10 of pregnancy. Mutation induction was monitored post-natally by checking the fur of the offspring for color spots that result from expression of a recessive gene involved in coat-color determination. Of the environmental chemicals tested, only 4-chloro-o-toluidine was mutagenic in the spot test. This positive result was in agreement with in vitro experiments and its carcinogenic potential in the mouse. However, the mouse carcinogens chlordimeform and N-formyl-4-chloro-o-toluidine were negative, as was the non-carcinogen lisuride hydrogen maleate. N-Formyl-4-chloro-o-toluidine and lisuride hydrogen maleate have been reported to be weakly positive in the Ames test. The positive controls EMS and ENU showed a clear mutagenic response.
Amidines↗
A consideration of the hormonal basis and phosphate leak hypothesis of absorptive hypercalciuria.
Fifty patients with absorptive hypercalciuria (AH), 25 normal subjects (NS), and 25 nonhypercalciuric patients with stone disease (NHSF) were studied using an oral calcium tolerance test and 24-h urine collections on both a restricted and an unrestricted calcium intake. Mean (+/- SD) fasting fractional calcium excretion was increased in the patients with AH (2.7 +/- 1.1% vs. 1.4 +/- 0.6% in the NS; P less than 0.001) and was negatively correlated with fasting nephrogenous cAMP, suggesting that this renal calcium leak was secondary to parathyroid suppression. Plasma 1,25-dihydroxyvitamin D [1,25-(OH)2D] was elevated in 80% of patients with AH and was high normal in the remaining 20%. Ten patients, selected on the basis of results for 1,25-(OH)2D greater than 4 SD from the normal mean, displayed a particularly severe pattern of abnormalities, including mild hypercalcemia in two patients. Pooled data from the NS and patients with AH revealed a significant negative correlation between the plasma concentration of 1,25-(OH)2D and the renal phosphate threshold (r = -0.40; P less than 0.001), but this correlation lost significance when the NHSF were substituted for the NS as a control group (r = -0.07; P = NS). These findings 1) provide a pathophysiological basis for the increase in fasting calcium excretion commonly observed in hypercalciuric patients, and 2) stress the importance of circulating 1,25-(OH)2D in the pathogenesis of the syndrome, but 3) fail to support the phosphate leak theory of pathogenesis.
Adult↗
Chemical abnormalities.
This article provides an in-depth summary of standard and recently developed biochemical assays that are useful for the evaluation of the patient with metabolic bone disease. In addition, each of the common metabolic bone diseases is discussed in the context of the associated chemical abnormalities.
Alkaline Phosphatase↗
Recurrent agranulocytosis induced by two different antithyroid agents.
A 45-year-old woman with thyrotoxicosis developed agranulocytosis after treatment with propylthiouracil. When the thyrotoxicosis recurred, accompanied by a severe psychotic reaction, administration of antithyroid medication was recommenced. The patient was given methimazole instead of propylthiouracil but, 10 weeks later, agranulocytosis again occurred. This is, to the best of our knowledge, the first report of a case in which agranulocytosis followed treatment with both propylthiouracil and methimazole in the same patient.
Agranulocytosis↗
Criteria for the standardization of Salmonella mutagenicity tests: results of a collaborative study. II. Studies to investigate the effect of bacterial liquid culture preparation conditions on Salmonella mutagenicity test results.
The influence of various parameters and growth conditions in the "overnight culture" of Salmonella typhimurium strains on mutagenicity test results was investigated. A number of factors were first suspected to be of some importance for the quantitative outcome of the mutagenicity test. None of them, however, was found to influence the results to such a marked extent as to be a major source of variability. Only the brand of nutrient broth used for the propagation of the bacteria proved finally to have a certain effect on the number of (spontaneous and induced) revertant colonies, although no precise and quantitative statements can be made with regard to a possible standardization of this experimental segment in the Salmonella mutagenicity test. The occurrence of such unpredictable but noticeable influences is, however, evidence for the importance of an intralaboratory optimization and standardization of all parts of the test procedure.
Animals↗
Verapamil improves exercise capacity in chronic atrial fibrillation: double-blind crossover study.
Oral verapamil has previously been shown to reduce heart rate at rest and during mild exercise in chronic atrial fibrillation. Its efficacy in improving cardiovascular performance at higher levels of exercise and its safety were investigated in a prospective, randomized, placebo controlled double-blind study preceded by an open label titration phase in 20 digitalized patients with chronic atrial fibrillation. Maximal exercise capacity was improved (from 522 +/- 257 to 806 +/- 348 work units, p less than 0.0005) when tested by a standardized multistage ergometry exercise test. Heart rate was also reduced at rest, at the end of 3 minutes of 300 KPM exercise, and at the point of maximal exercise. Blood pressure and double product were also reduced. Its efficacy and safety may make verapamil the treatment of choice in chronic atrial fibrillation.
Adult↗
The acute hemodynamic effects of intravenous verapamil in coronary artery disease. Assessment by equilibrium-gated radionuclide ventriculography.
The acute hemodynamic effects of an i.v. bolus of verapamil, 0.1 mg/kg or 0.06-0.075 mg/kg, were examined by serial radionuclide studies in 46 patients with coronary artery disease. In 20 patients with ejection fractions (EFs) greater than 35% (group 1A), verapamil, 0.1 mg/kg given over 1-11/2 minutes, had a biphasic effect: first, a transient decrease in EF accompanied by increased left ventricular (LV) volumes and cardiac output equivalents; then, an overshoot of EF to values above control, accompanied by a decrease in peripheral vascular resistance and a drastic decrease in LV volumes, while cardiac output equivalent remained slightly elevated. In eight patients with EFs less than 35% (group 1B), only the first effect on EF was noted. In 10 patients with EFs greater than 35% (group 2), verapamil, 0.06-0.075 mg/kg, exerted qualitatively similar but milder effects on hemodynamic function. Finally, verapamil, 0.1 mg/kg given more slowly, over 2-21/2 minutes, produced no significant changes in EF or LV volumes in another eight patients (group 3). The acute effects of verapamil are thus both time-related and dose-dependent. They are also related to the baseline functional reserve of the left ventricle. This study documents that verapamil exerts a depressant effect on LV function. However, the transient nature of this depression and the quick recovery to normal or above-normal values indicate that verapamil, in the doses used in this study, is safe to use intravenously in patients with coronary artery disease.
Adult↗
The early recognition of right ventricular infarction: diagnostic accuracy of the electrocardiographic V4R lead.
The sensitivity and specificity of ST-segment elevation in the right precordial lead V4R as an early indicator of right ventricular infarction were examined in a consecutive series of 110 patients admitted for acute inferior myocardial infarction. The sensitivity was 82.7%, the specificity 76.9% and the positive predictive value 70% in 58 patients with right ventricular infarction documented by autopsy or a combination of radionuclide ventriculography and one or more of the following tests: echocardiography, technetium-99m pyrophosphate scintigraphy and hemodynamic monitoring. The negative predictive value was 87.7%. Because of its simplicity and its high sensitivity and specificity, recording of V4R should be an intrinsic part of the early evaluation and electrocardiographic examination of acute inferior wall infarction.
Adult↗
Increased bone turnover with decreased bone formation by osteoblasts in children with osteogenesis imperfecta tarda.
Iliac crest bone biopsies from nine children (6-15 yrs old) with osteogenesis imperfecta tarda (OI) have been studied by bone histomorphometry after double fluorescent labeling with tetracycline and compared to five unlabeled biopsies from normal children in the same age group. The results indicate that children with OI have a low trabecular bone volume associated with an increased bone turnover rate. Bone formation is increased at the tissue level despite a decrease in the activity of individual osteoblasts. The original defects in OI seems, therefore, to be in the rate of matrix synthesis by osteoblasts. It is, however, compensated by an increase in the number of these cells. These results suggest that these children were not losing bone at the time of the biopsy, which fits with the clinical stability of OI with age. Our study therefore suggests that the osteopenia observed in OI is most likely due to an inability to accumulate bone during growth, as normal children do, rather than to a progressive net loss of bone.
Adolescent↗