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Biomedical subjects

J Camps

Publications and source records attributed to J Camps.

At least 145 records · Page 8Linked to original sources

Evidence that renal prostaglandins are involved in renal water metabolism in cirrhosis.

Plasma antidiuretic hormone (ADH) and urinary prostaglandin E2 excretion (UPGE2V) were measured in basal conditions, after water restriction, and after water-loading in 10 normal subjects (free water clearance after the water load, CH2O, 9.6 +/- 0.8 ml/min) and in 27 patients with cirrhosis and ascites (13 with a positive CH2O: 3.6 +/- 0.5; 14 with a negative CH2O: -0.37 +/- 0.007). Plasma ADH and UPGE2V were significantly increased in patients with a positive CH2O as compared with normal subjects. Patients with a negative CH2O showed a significantly higher plasma ADH and a lower UPGE2V and GFR than did normal subjects and patients with the positive CH2O. In 18 additional subjects (6 normal and 12 with cirrhosis, ascites, and a positive CH2O) submitted to a sustained water overload, the i.v. administration of 450 mg of lysine acetylsalicylate (LAS) induced a marked reduction of UPGE2V, but it had no effect on plasma ADH. LAS did not alter GFR and CH2O in normal subjects; however, it reduced CH2O in all the 12 patients (from 5.1 +/- 0.4 to 0.6 +/- 0.3) and the GFR in only 6 of these patients. These results suggest (a) that renal PGE2 plays an important role in the maintenance of water excretion in cirrhosis with ascites, and (b) that impaired ability to dilute the urine in cirrhosis may be a consequence of the simultaneous occurrence of impaired renal hemodynamics, nonostomic hypersecretion of ADH, and reduced renal production of PGE2.

Arginine Vasopressin↗

Effect of demeclocycline on renal function and urinary prostaglandin E2 and kallikrein in hyponatremic cirrhotics.

8 cirrhotics with hyponatremia were given demeclocycline (DMC) 900 mg/day to investigate its effect on renal function, plasma renin activity, aldosterone and urinary excretion of prostaglandin E2 and kallikrein. In 7 patients DMC induced an increase of free water clearance (from -0.36 +/- 0.06 to 0.13 +/- 0.06 ml/min) and serum sodium concentration (from 125.4 +/- 0.09 to 131.1 +/- 1.0 mEq/l, mmol/l). In 5 of these patients DMC also induced a marked reduction of glomerular filtration rate (from 72.2 +/- 6.2 to 31,2 +/- 4.7 ml/min) and renal plasma flow (from 468 +/- 98 to 195 +/- 55 ml/min) which could not be explained on the basis of hypovolemia. In each case this renal impairment was not associated with changes in urinary concentration of beta 2-microglobulin, urinary casts excretion, fresh urine sediment or urine protein content and disappeared after discontinuation of the drug. DMC induced a marked increase in the urinary excretion of prostaglandin E2 (from 0.82 +/- 0.27 to 6.16 +/- 1.91 ng/min) in 6 out of the 7 patients who responded to DMC and a marked reduction in urinary kallikrein (from 16.1 +/- 4.4 to 4.2 +/- 1.6 pkat/min) in the 5 patients who developed renal insufficiency. The serum DMC concentration was greater than 5 micrograms/ml in all patients who responded to DMC, greater than 8 micrograms/ml in all cases who developed renal insufficiency and of 3 micrograms/ml in the case not responding to DMC. (ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗

[Specificity of the determination of urinary kallikrein activity using an amidolytic assay].

The specificity of a method for the determination of the urinary kallikrein activity based on the amidolytic hydrolysis of the synthetic substrate H-D-valyl-leucyl-arginine-p-nitroanilide has been studied. Results show a good specificity for kallikrein. The amidolytic activity was totally inhibited by aprotinin. The urinary amidolytic activity showed identical dependence on changes in the ionic strength and pH of the incubation medium as the highly purified kallikrein. The sensitivity of the assay was 0.6 nkat/l. The intra-assay coefficient of variation was 4% and the inter-assay coefficient of variation was 10%. The percentage of recovery was between 100 and 110% indicating that no activators or inhibitors of the kallikrein activity on this substrate were present in the urinary samples. Values obtained in presumably healthy subjects were 0.14 +/- 0.08 pkat/s in man (range: 0.05 - 0.27 pkat/s) and 0.49 +/- 0.11 pkat/s in rat (range: 0.35 - 0.58 pkat/s).

Adult↗

Radioimmunoassay for arginine-vasopressin in cold ethanol extracts of plasma.

A radioimmunoassay for arginine-vasopressin in human plasma with use of a commercially available antibody was developed and evaluated. The hormone was extracted from plasma with cold 98% ethanol, which showed a significantly higher (p less than .001) and more precise recovery than with the acetone-ether procedure (65.3 +/- 3.7% vs 50.8 +/- 6.0%, respectively). The sensitivity was 0.31 pg per tube. Results for normal subjects in different physiological conditions and in patients with diabetes insipidus and inappropriate antidiuretic hormone secretion showed the good reliability of the method.

Acetone↗

Antirifampicin antibodies in acute rifampicin-associated renal failure.

5 patients with acute renal failure (3 with thrombopenia and hemolysis) induced by the reintroduction of rifampicin are described. No correlation was found between the severity of clinical manifestations and the total dose taken by the patients. In all but 1 patient, antirifampicin antibodies were detected. Antibodies suggested to be of the IgM class were detected in all 3 patients with hematological disorders. The pattern of non-specific acute tubular necrosis found in the 2 biopsied patients, indistinguishable from that of ischemic origin, raised the possibility of a vascular-mediated damage. In 3 patients, the possibility of a triggering immunoallergic mechanism is discussed.

Acute Kidney Injury↗

[A study of anemia in 86 patients on hemodialysis (author's transl)].

Anemia is one of the complications of terminal chronic renal failure that may worsen with periodical hemodialysis because of residual blood losses in the dialyzers that may be significant if clotting occurs within the circulation system. The potential iron deficiency component of the anemia has been studied in 86 patients submitted to periodic hemodialysis by measurement of hemoglobin, serum iron, transferrin saturation, total iron binding capacity, and ferritin. The following correlations were investigated: degree of anemia and type of renal disease, months on hemodialysis and hemoglobin, months on hemodialysis and serum ferritin, and liters of blood transfused and serum ferritin. Statistically significant correlations were found between months on hemodialysis and hemoglobin, and between liters of blood transfused and serum ferritin. From the correlation between serum iron and ferritin the patients could be classified in three groups: 1, with either normal or low serum iron and ferritin, candidates to iron therapy; 2, with elevated serum iron and ferritin, needing no iron treatment; and 3, with unequal changes of serum iron and ferritin, in whom iron kinetic studies are indicated in order to discover the patents that may benefit from iron therapy.

Adolescent↗

[Synthesis of cyclic AMP from renal cortex in vitro (author's transl)].

The parathyroid-hormone sensitive adenylate-cyclase from renal rat cortex has been studied. Mg2+ acts as stimulator at a specific locus increasing the apparent Vmax slightly from 50 to 60 nmol of cAMP per gram of protein if the Mg2+ concentration increases from 3.25 to 16 mM, and decreases the apparent KM from 2 to 0.4 mM. Fluoride decreases the apparent KM from 5 mM in NaF concentrations of 0 to 2 mM in NaF concentrations 2 mM. Magnesium ion also decreases the apparent Ka for NaF.

Adenylyl Cyclases↗

[Study of the causes of death in a hemodialysis unit (author's transl)].

A review is made of the deaths which occurred in a hemodialysis unit between 1969 and 1977. Sixty-two patients were treated during this period, 18 of whom died. The actuarial percentages of survival are also established. The mortality rate was 15.5 percent during the initial period and 31.5 percent after the fourth year. Deaths in the first monts were caused by cardiac and infectious complications. Those occurring at a later period resulted from the lack of good vascular access which is necessary to maintain a good quality of dialysis.

Adolescent↗