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Biomedical subjects

P Gross

Publications and source records attributed to P Gross.

At least 19 recordsLinked to original sources
PubMed1992

[Different effects of fibrates on the lipoprotein profile. Comparison of the effectiveness of gemfibrozil and bezafibrate in various types of hyperlipoproteinemia].

AIMS: To compare the efficacy and tolerability of Gemfibrozil and Bezafibrate in patients with hyperlipoproteinemia, types IIa, IIb and IV. METHOD: In an open, randomized parallel study, the tolerability and efficacy of Gemfibrozil (G) and Bezafibrate (B) were investigated over a period of 12 weeks in 178 hyperlipidemic (HLP) patients first submitted to an 8-week "wash-out" (diet only) phase. In HLP type IIa patients, LDL cholesterol was lowered (G: -13%, B: -10%). In HLP type IIb, a decrease in triglyceride (TG) levels (G: -41%, B: -31%), an increase in HDL-cholesterol (G: +19%, B: +5%), and a decrease in the total cholesterol/HDL cholesterol ratio (G: -32%, B: -9%) predominated. Patients with type IV HLP responded to both fibrates with an appreciable reduction in TG levels (G: -45%, B: -42%). The effects of the preparations differed significantly with respect to the elevation of HDL cholesterol and a decrease in the total cholesterol/HDL cholesterol ratio in HLP type IIb patients. The respective lipid baseline concentration appeared to be of importance for the sense and extent of the changes induced.

Adult↗
PubMed1992

Internalization of V2-vasopressin receptors in LLC-PK1-cells: evidence for receptor-mediated endocytosis.

The mechanism of internalization of the vasopressin-receptor (V2-subtype) of LLC-PK1-cells, a pig renal tubular cell line, is unknown. We studied internalization utilizing a novel, highly specific vasopressin analogue ((125I)-[8-p(OH)-phenylpropionyl]-LVP, 2000 Ci/mmol). Scatchard analysis performed with membranes of LLC-PK1-cells revealed a Kd of 0.8 +/- 0.2 nM and a Bmax of 366 +/- 41 fmol/mg of protein. Degradation of the ligand was excluded by RP-HPLC-analysis. Internalization was proven by the acid-wash technique, quantitative light-microscopic autoradiography and electron microscopy. The ligand was internalized in a time- and temperature-dependent manner. At 4 degrees C, no uptake was found; at 22 degrees C, after 30 min of incubation, more than 50% of the radioligand was found inside the cell. Electron microscopy demonstrated that plasma-membrane bound vasopressin receptors are internalized by receptor-mediated endocytosis via coated pits.

Animals↗
PubMed1992

Intracellular distribution of endothelin-1 receptors in rat liver cells.

We studied the binding of (125I)-endothelin-1 as well as that of the vasopressin analogue (125I)-[8-phenylpropionyl]-LVP to purified plasma membranes, Golgi cisternae and cell nuclei from rat liver. Cell organelles were isolated by differential centrifugation and discontinuous sucrose gradients. Endothelin-1 exhibited specific binding to plasma membranes, Golgi cisternae and nuclei, while the binding of (125I)-[8-phenylpropionyl]-LVP was restricted to the plasma membranes. The number of receptors (Bmax) and the binding constants (Kd) were determined by Scatchard analysis of competition binding studies. In all cases only one class of Et-1 binding sites could be detected. The presence of Et-1 receptors on the Golgi complex either indicates that the receptor is glycosylated within the cisternae or alternatively, there exists a recycling pathway. The unexpected finding of Et-1 receptors on highly purified nuclei suggests that this peptide may exert part of its biological functions intracellularly via the nucleus.

Animals↗
PubMed1992

[Appendicitis in children].

In 1992, appendicitis is still common among children. Mortality due to a belated or erroneous diagnosis is far from being nil. The disease must always be present in the clinician's mind, and its diagnosis is purely clinical. No significant advance has been made on this subject, and clinical findings remain of paramount importance. Hospitalization for observation at the slightest doubt and emergency surgery when the diagnosis is probable are the best means of improving the management of appendicitis in children.

Acute Disease↗
PubMed1992

Hemodynamic effects of isradipine and nifedipine in chronic sustained hypertension.

As isradipine is known to be less cardiodepressant than nifedipine, myocardial wall stress--an important determinant of cardiac oxygen demand--may also be more favorably influenced by isradipine. Therefore, the acute effects of an intravenous (i.v.) infusion of isradipine (0.4 mg) vs. nifedipine (2.0 mg) on cardiac hemodynamics and systolic wall stress were investigated in a crossover study of 12 hypertensive patients. Vasodilation-induced reflex activation was limited by pretreatment with i.v. propranolol at 0.1 mg/kg of body weight. The hemodynamic parameters measured were statistically comparable at baseline and after propranolol with both calcium antagonists, as was blood pressure reduction. However, the end-systolic volume decreased with isradipine, but not with nifedipine [before: 69 +/- 7.0 ml (mean +/- SEM); after: 61 +/- 6.1 ml; 2p less than 0.01 vs. before: 62 +/- 6.1 ml; after: 64 +/- 7.0 ml; NS, (difference between changes in response to treatments: 2p less than 0.05)]. The ejection fraction increased only with isradipine vs. nifedipine [before: 48 +/- 2.3%; after: 54 +/- 2.3%; 2p less than 0.001 vs. before: 52 +/- 2.0%; after: 52 +/- 2.3%; NS (difference between changes in response to treatments: 2p less than 0.05)]. Systolic wall stress decreased significantly more with isradipine than with nifedipine [before: 2,767 +/- 231; after: 2,153 +/- 162 relative units; 2p less than 0.001 vs. before: 2,636 +/- 212; after: 2,310 +/- 199 relative units; 2p less than 0.05 (difference between changes in response to treatments: 2p less than 0.05)]. These results suggest that isradipine, given acutely, unloads the heart more than does nifedipine.

Aged↗
PubMed1991

Evaluation of (13C)ethanol incorporation into very-low-density lipoprotein triglycerides using gas chromatography/isotope ratio mass spectrometry coupling.

Gas chromatography/isotope ratio mass spectrometry (GC/IRMS) coupling was used to evaluate (13C)ethanol incorporation into plasmatic very-low-density lipoprotein (VLDL) triglycerides of three healthy human volunteers. After the perfusion of 13C-enriched alcohol, VLDL triglyceride fractions were extracted from plasma samples and prepared for the analysis of (13C)fatty acid methyl esters. The GC/IRMS coupling line, the analytical procedure and the data collection are described. The results show that ethanol itself may be used as a substrate for lipogenesis, though to a small extent: less than 10% of VLDL triglycerides may be derived from this metabolic pathway. Ethanol incorporates predominantly into myristic and palmitic acid. The small amount of sample material required for analysis, which minimizes the amount of isotope-labelled substrate required, makes this technique a valuable tool for metabolic investigations in human subjects.

Carbon Isotopes↗
PubMed1991

[Significance of hyponatremia in patients with oropharyngeal tumors].

We observed 29 patients with hyponatremia associated with oropharyngeal carcinoma. In 19/29 the hyponatremia was attributable to a decreased effective arterial blood volume whereas in the remainder (10/29) the presence of SIADH could be demonstrated. These etiologies of hyponatremia were best differentiated by the plasma urea concentration (less than 30 mg/dl in SIADH), urate concentration (less than 4,0 mg/dl in SIADH) and creatinine concentration (less than 0,9 mg/dl in SIADH). Furthermore, SIADH patients had a spontaneous natriuresis. The mainstay of therapy in either form of hyponatremia is fluid restriction (less than 1 l/d).

Carcinoma, Squamous Cell↗
PubMed1991

Alzheimer's disease in Down's syndrome with SPECT.

Alzheimer's disease often occurs in patients with Down's syndrome. SPECT scanning with I-123 IMP and Tc-99m HMPAO identifies decreased cerebral perfusion and metabolism in these patients at lower cost. In this case, SPECT scanning revealed changes in Alzheimer's disease in a Down's syndrome patient.

Alzheimer Disease↗
PubMed1991

[The hemodynamic effects of isradipine and nifedipine in hypertension].

Hemodynamic Effects of Isradipine and Nifedipine in Hypertension Myocardial wall tension is an important determinant of the oxygen demand, the function and the degree of hypertrophy of the left ventricle. Myocardial wall tension should be influenced more favourably by a non-cardiodepressive antihypertensive than by a potentially cardiodepressive one. Therefore, we investigated the effects of an intravenous infusion of the calcium antagonists isradipine (I; 0.4 mg; 3,5-pyridinecarboxylic acid, 4-[benzofurazanyl]-1,4-dihydro-2,6-dimethyl-,methyl-ethylester+ ++ [9CI]; CAS75695-93-1) and nifedipine (N; 2.0 mg) resp., on hemodynamics and myocardial wall tension in 12 hypertensives by an intraindividual comparison. The adrenergic reflex activation induced by vasodilation was limited by pre-medication with 0.1 mg propranolol/kg body weight (i.v.) before application of I and N. Baseline blood pressure of the patients and its changes in response to both calcium antagonists were statistically comparable, as were the left ventricular end-diastolic volumes. The end-systolic volumes, however, decreased significantly on I but not on N: before I: 69 +/- 7.0 (mean +/- standard error), after I: 61 +/- 6.1 ml, 2p less than 0,001; before N: 62 +/- 6.1, after N: 64 +/- 7.0 ml, n.s. (difference to I: 2 p less than 0.05). Stroke volume increased only on I (before I: 62 +/- 4.1, after I: 69 +/- 4.1 ml, 2p less than 0.001; before N: 64 +/- 3.5, after N: 65 +/- 3.8 ml, n.s. (difference to I: 2p less than 0.05)).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Lithium treatment reduces the renal kallikrein excretion rate.

Lithium salts are widely used agents for the prophylactic treatment of affective disorders. Lithium salts may be associated with distal nephron dysfunction. Kallikrein is a protease which is generated by the distal nephron. We used an amidolytic assay of chromatographically purified enzyme to determine the urinary excretion rate of active kallikrein in relation to lithium treatment. All plasma lithium concentrations were within the therapeutic range (0.4 to 0.9 mmol/liter). In 15 patients the urinary excretion rate of active kallikrein was 267.4 +/- 65.6 mU/24 hrs before lithium treatment, and fell to 117.8 +/- 39.6 mU/24 hrs (P less than 0.05) on day 14 of lithium treatment. This reduction was associated with a decrease of immunoreactive kallikrein in the same urines by 66%. In another 15 patients who had undergone lithium therapy for an average period of 5.6 years, the urinary excretion rate of active kallikrein was 86.1 +/- 14.5 mU/24 hrs, while 21 age-matched healthy controls had an excretion rate of 364.1 +/- 58.4 mU/24 hrs (P less than 0.05). Measurements of immunoreactive kallikrein in the same urine samples demonstrated a reduction of kallikrein after long-term lithium treatment by 78%. These observations could not be attributed to changes in creatinine clearance, renal sodium or potassium excretion rates or plasma concentrations of aldosterone and vasopressin. Addition of lithium to the urine in vitro had no demonstrable effect on kallikrein measurement by amidolytic assay. We conclude that lithium in therapeutic plasma concentrations may directly suppress the secretion of kallikrein by renal connecting tubule cells.

Adult↗
PubMed1990

[Ano-rectal sphincter myectomy in children. Indications and results].

Ano-rectal myectomy, described by B. Duhamel in 1965, is the logical therapy of rectoanal achalasia; an experience of 117 cases is reported. Clinical examination and radiological investigations have been made prior to surgery. This surgical procedure is simple, without complication. Three kinds of rectoanal achalasia are described: achalasia with structural change of the internal sphincter (fibrosis, sclerosis); achalasia with a functional sphincteric disorder (with normal histology); achalasia with intrinsic innervation abnormality. Excellent results have been observed in the two first groups but more variable successful results in the third group which concerns short segments of Hirschsprung's disease.

Adolescent↗