Differential effect of nicotine on plasma norepinephrine levels in normal humans and in patients with congestive heart failure.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
A Katz
Publications and source records attributed to A Katz.
[Long-term follow-up of prosthetic heart valves].
257 patients underwent single or double heart valve replacement between 1964-1986. In 141 (55%) after isolated mitral valve replacement, operative mortality was 14.8% and after 5, 10, 15 and 20 years, actuarial survival was 84%, 70%, 59% and 44%, respectively. In 70 who underwent isolated aortic valve replacement, operative mortality was 7.1% and after 5, 10, 15 and 20 years, actuarial survival was 85%, 85%, 72% and 72%. In 46 who underwent combined aortic and mitral replacement, operative mortality was 4.3% and after 5, 10 and 15 years, actuarial survival was 78%, 71% and 71%.
Actuarial Analysis↗
Rearrangement between ornithine decarboxylase and the switch region of the gamma 1 immunoglobulin gene in alpha-difluoromethylornithine resistant mouse myeloma cells.
We demonstrate here that the functional ornithine decarboxylase (ODC) gene of alpha-difluoromethylornithine (alpha-DFMO, a suicide inhibitor of ODC) resistant mouse myeloma 653-1 cells has been rearranged with the immunoglobulin heavy chain locus in a c-myc like manner. Structural analysis of a molecular clone representing this gene revealed that it is joined in a head to head configuration to the switch region of the gamma 1 immunoglobulin gene. Comparison of this rearranged ODC gene to a germline ODC gene isolated from mouse liver DNA revealed identity in the region downstream to the breakpoint which was mapped to position -1371 +/- 1 relative to the transcription initiation site (position +1). In the switch region of the gamma 1 immunoglobulin gene the breakpoint falls within a 49 bp repeat, in a sequence frequently involved in class switching. This finding further supports the notion that in B cells the immunoglobulin gene clusters are prone to random rearrangements which under selection for a tumorigenic phenotype involve oncogenes. However, as demonstrated here, employment of specific pharmacological selection can reveal rearrangements with non-oncogenic genes.
Animals↗
Deleterious effects of intravenous verapamil in Wolff-Parkinson-White patients and atrial fibrillation.
Three patients presented to the emergency room with atrial fibrillation and fast ventricular response with wide preexcited QRS complexes (Wolff-Parkinson-White syndrome). All three patients received intravenous verapamil (5-10 mg). The first patient developed ventricular fibrillation requiring several defibrillations; the second patient developed severe hemodynamic deterioration requiring urgent cardioversion; in the third patient a marked increment in the ventricular response was noted, however, there was no hemodynamic impairment. Verapamil may cause detrimental results when given to patients with the Wolff-Parkinson-White syndrome and atrial fibrillation. Its administration should therefore be considered as an absolute contraindication in these patients.
Adult↗
Euglycemic hyperinsulinemia increases glucose 1,6-bisphosphate in human skeletal muscle.
1. The effects of physiologic concentrations of insulin on the contents of glucose 1,6-bisphosphate (glucose 1,6-P2) and regulators of glucose 1,6-P2 synthase in intact human skeletal muscle have been investigated. 2. Insulin increased glucose 1,6-P2 from a basal value of 70 +/- 6 to 135 +/- 12 mumol/kg dry wt (P less than 0.001). 3. Activation of synthase could not be associated with changes in its inhibitors (fructose 1,6-P2, Pi, citrate) or its substrate glucose 6-P.
Analysis of Variance↗
Transient complete atrioventricular block induced by a chest thump in a patient with ventricular tachycardia.
We describe an unusual case of transient complete atrioventricular block induced by a chest thump during resuscitation in a patient with ventricular tachycardia.
Aged↗
Purification and properties of O6-methylguanine-DNA-methyltransferase in human hepatic tissue.
O6-Methylguanine-DNA-methyltransferase was partially purified from human liver. The transferase activity was purified by means of ammonium sulfate fractionation, DEAE-cellulose, Sepharose 6B, and double-strand DNA-cellulose chromatography. The native enzyme showed a molecular weight of about 44,000 as determined by gel filtration and a minimal molecular weight of 22,000 as obtained from SDS-PAGE. The native enzyme was unstable and underwent dissociation and decrease of activity in the presence of detergents.
Adult↗
Increased concanavalin A-induced suppressor cell activity in humans with occupational lead exposure.
E-rosette-forming cells (E-RFC), mitogen-induced blast transformation, OKT4+, OKT8+ cells, and their ratio were found to be normal in 10 subjects chronically exposed to lead with blood levels of 40-51 micrograms%. However, concanavalin A (Con A)-induced suppressor cell activity (SCA) in these subjects was significantly greater than in normal matched controls. The clinical relevance of this observation is not clear, but it may have some bearing on the various immunologic defects described in lead exposure.
Adult↗
Life and AH26 as sealers in thermatically compacted gutta-percha root canal fillings: leakage to a dye.
Calcium hydroxide-containing root canal sealers may encourage apical obturation by cementum. Hard-setting bases with calcium hydroxide induce calcification, but set too quickly to permit lateral condensation of gutta-percha. Since thermatic compaction requires less time than lateral condensation, the possibility of using this method with Life as a sealer was investigated. Seventy roots were prepared and filled with gutta-percha using the Engine Plugger for thermatic compaction. In one group of 20 Life was used as a sealer. AH26 was used in another group of 20. The remainder served as controls. Leakage was tested by linear penetration of Procion B Blue dye measured after clearing the teeth. In the Life group the mean dye penetration was 0.575 mm versus 1.025 mm in AH26, but the difference was not statistically significant. The results indicated that Life could be used in thermatic compaction of gutta-percha and that it provided a seal comparable to that obtained with AH26.
Bismuth↗
Percutaneous needle biopsy of the transplanted kidney: technique and complications.
Over 11 1/2 years, 420 percutaneous needle biopsies were obtained from the transplanted kidneys of 205 patients at one institution. The procedure was performed by one nephrologist and 55 nephrology trainees. No limit was placed on the number of biopsies performed on one kidney, and the highest number was seven. The complications were macroscopic hematuria in 28 biopsies, prolonged hematuria (greater than 24 hours) in eight, transient anuria in five, and prolonged anuria requiring surgical intervention in one. Perinephric hematoma occurred in three patients; retroperitoneal hematoma led to compression of the iliac vein in one. None of these complications led to loss of the transplant. It is suggested that the freedom from serious complication is related to the safety of the technique and the precautions applied to preparation of the patient. These are described in detail.
Adolescent↗
Alpha 2-adrenergic stimulation and vasopressin in congestive heart failure.
Patients with chronic heart failure (CHF) have increased plasma levels of the antidiuretic hormone arginine vasopressin (AVP). The stimulus for increased AVP secretion is unknown, but appears to involve a nonosmotic drive which alters normal osmoregulatory mechanisms. Centrally acting alpha 2-adrenergic agonists suppress AVP secretion in experimental animals. To examine the hypothesis that such effects might be apparent on the chronically elevated AVP levels in patients with CHF, we measured AVP, heart rate (HR), mean arterial pressure (MAP), and plasma norepinephrine (NE) after 4 mg oral guanabenz in nine patients with this disease. Plasma NE decreased from 513 +/- 131 to a minimum of 371 +/- 117 pg/ml (p less than 0.02) 5 h postdrug. HR decreased from 80 +/- 9.3 to 74 +/- 10 beats/min (p less than 0.05) and MAP decreased from 88 +/- 8.5 to 83 +/- 10 mm Hg (p less than 0.05). Plasma AVP, however, did not change from baseline levels of 5.6 +/- 1.6 pg/ml. Serum osmolality was also constant. These data do not support a possible role for acute increases of alpha 2-adrenergic activity in suppressing the increased plasma AVP levels of CHF, at least under basal conditions at constant osmolality.
Adrenergic alpha-Agonists↗
Management of tubal pregnancy with methotrexate.
Ten women with tubal ectopic pregnancy were treated by the injection of methotrexate into the gestational sac under direct laparoscopic vision followed by a course of intramuscular therapy including folinic acid rescue. One course of treatment induced resolution of the extrauterine pregnancy in eight women. Complete resolution (beta-hCG less than 10 miu/ml) was achieved within 6-47 days (mean 14.5 days). Serum beta-hCG levels started to decline 3.4 days from the beginning of therapy. Length of hospital stay was 5-11 days (mean 6.4 days). Treatment failed in two patients. One woman had a laparoscopic tubal clip sterilization concomitantly with methotrexate treatment. Tubal patency was demonstrated in all the other seven women (100%) tested subsequently. There is a need to establish criteria for patient selection before methotrexate becomes a routine treatment for tubal pregnancy.
Adult↗
Myasthenia gravis and chronic lymphocytic leukaemia.
Explore the source record for details and available documents.
Female↗
Hypoxaemia increases the accumulation of inosine monophosphate (IMP) in human skeletal muscle during submaximal exercise.
The effect of hypoxaemia on the muscle content of inosine monophosphate (IMP) during short-term, low-intensity exercise has been investigated. Six men cycled twice for 5 min at 120 +/- 6 W (mean +/- SE), which corresponded to approximately 50% of their maximal normoxic O2 uptake, breathing air (N) on one occasion and 11% O2 in N2 (H) on the other. Oxygen uptake at the end of the exercise period was similar between treatments. No significant difference was observed between H and N in the muscle metabolite contents at rest. Muscle content of phosphocreatine (PCr) decreased and lactate increased during exercise. Post-exercise PCr during H was 80% of the value during N (P greater than 0.05) and post-exercise muscle lactate was fourfold higher during H than during N (P less than 0.001). Post-exercise muscle content of ADP was significantly higher during H than during N (P less than 0.01), while ATP and AMP remained constant under both H and N exercise (P greater than 0.05 H vs N). IMP was not detectable in pre-exercise muscle samples (less than 0.01 mmol kg-1 dry wt) but increased during N exercise (0.03 +/- 0.01 mmol kg-1 dry wt, wt, P less than 0.05) and even more during H exercise (0.16 +/- 0.05 mmol kg-1 dry wt, P less than 0.05, H vs N). Post-exercise IMP was negatively related to PCr (r = -0.90) and positively related to lactate (r = 0.88). It is concluded that hypoxaemia results in an enhanced accumulation of IMP during submaximal exercise and that the IMP level is related to the degree of anaerobic energy utilization.
Adult↗
Effect of hypoxia on glucose metabolism in human skeletal muscle during exercise.
The effect of respiratory hypoxia on muscle glucose metabolism during short-term dynamic exercise has been investigated. Eight men cycled for 5 min at 120 +/- 6 W (mean +/- SE), which corresponded to 50% of maximal O2 uptake during normoxia (N), breathing air (N) on one occasion and 11% O2 (hypoxia-H) on the other. Biopsies were taken from the quadriceps femoris muscle before and after exercise. Oxygen uptake during exercise was not affected by H. The arterial blood glucose concentration during N exercise remained constant, but increased from 4.62 +/- 0.11 mmol l(-1) at rest to 5.22 +/- 0.19 mmol l-1 at the end of H exercise (P less than 0.05 vs N exercise). The intracellular glucose content at rest was low and did not change during N exercise, but was four times higher after exercise during H vs N (P less than 0.01). Glucose 6-P increased under both conditions but significantly more during H (P less than 0.01), while glucose 1,6-P2 was not significantly different between treatments either at rest or after exercise. It is concluded that: (1) glucose uptake by skeletal muscle during short-term exercise. It is concluded that: (1) glucose uptake by skeletal muscle during short-term exercise during H is not associated with a stoichiometric glucose utilization; (2) the inhibition of hexokinase during H (evidenced by increase in muscle glucose) is due primarily to the increase in glucose 6-P; and (3) glucose 1,6-P2 is of minor importance for the regulation of contraction-mediated flux through hexokinase in human skeletal muscle.
Adult↗
Effect of freeze-drying on measurements of pH in biopsy samples of the middle gluteal muscle of the horse: comparison of muscle pH to the pyruvate and lactate content.
Muscle biopsies taken after exercise, in comparison to those at rest, contain increased amounts of blood and this is a particular problem in studies of the horse. The inclusion of blood in muscle will introduce an upward bias in values of pH measured in muscle homogenates. In an attempt to control this, muscle biopsy samples of the middle gluteal from Thoroughbred horses were freeze-dried and dissected free of blood before determination of pH. Following exercise, muscle pH measured after freeze-drying was similar to that measured in homogenates prepared from frozen samples. In contrast, freeze-drying appeared to increase muscle pH in samples taken at rest. This was probably the result of loss of CO2 during freeze-drying. Muscle pH determined in freeze-dried samples taken at rest and after exercise was linearly related to pyruvate and lactate content (P less than 0.001). It is concluded that muscle samples taken after exercise can be freeze-dried and dissected free from blood before determination of pH, whereas this procedure will cause an alkaline shift in samples taken at rest.
Animals↗
[Effects of conditioned media of rat pleural mesothelial cells, transformed in vivo or in vitro by asbestos, on the proliferation of normal mesothelial cells. Comparison with epidermal growth factor, EGF].
The effect of conditioned media obtained from in vivo or in vitro asbestos-transformed rat pleural mesothelial cells on growth of normal mesothelial cells was studied. It was found that both conditioned media led to a reduction of cell proliferation as shown by a decrease in the following parameters: cell number, tritiated thymidine incorporation and percentages of S cells. Similar effects were obtained with EGF (Epidermal Growth Factor).
Animals↗