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J F Macias

Publications and source records attributed to J F Macias.

10 recordsLinked to original sources
PubMed1988

Autonomic nervous system in haemodialysis.

Fifty-two patients with terminal chronic renal failure on haemodialysis were assessed for the existence of autonomic neuropathy using the Valsava index. The values in the patients were lower than in the controls. Only a few symptoms could be related to the autonomic neuropathy. No correlation was found between Valsalva index and orthostatic or intradialysis hypotension, motor-nerve conduction velocity or plasma intact parathyroid hormone. Having demonstrated the existence of autonomic neuropathy, eight healthy subjects and ten patients on haemodialysis were studied to locate the segment of the autonomic reflex are affected. Heart rate and intraarterial pressure were monitored during the following tests: phenylephrine; hyperventilation; cold pressor; atropine; tyramine and adrenaline. An alteration was observed in baroreceptors, together with adrenergic hyperexcitability (reflected in the hypersensitivity of the sympathetic efferent pathway) and a greater response to the stimulus for the release of extra-adrenal adrenaline. The lower response to atropine is indicative of vagal alteration.

Adolescent↗
PubMed1988

Changes of contact phase proteins during haemodialysis.

Functional and immunological activities of factors XII and XI, Prekallikrein, high molecular weight kininogen and C-1-esterase inhibitor were studied in eight patients before, during and after haemodialysis. During and after dialysis sessions a significant decrease in the functional activities of Prekallikrein and high molecular weight kininogen (p less than 0.05) could be detected, whereas their immunological levels did not change. Furthermore C-1-esterase inhibitor increased after dialysis (p less than 0.05). These results indicate activation of the kinin system during haemodialysis.

Adult↗
PubMed1985

Plasma renin activity, plasma aldosterone and distal urinary acidification in diabetics with chronic renal failure.

The renin-angiotensin-aldosterone system and the acidification capacity of the renal tubule were studied in 13 diabetic patients with chronic renal failure. As a whole, the group showed hyporeninaemic hypoaldosteronism (HH). Studied alone, 12 of the 13 patients presented the requirements for HH. This group showed hypercholaemic hyperkalaemic metabolic acidosis with a disturbance in renal acidification which may be classified as Type IV renal tubular acidosis. The results of this group were compared to those of another two groups; one of diabetic patients without chronic renal failure and the other with chronic renal failure (C Cr less than 40ml/min); both were seen to show different behaviour to that of the group affected by the two processes.

Acidosis, Renal Tubular↗
PubMed1984

DDAVP in uremia.

Explore the source record for details and available documents.

Adolescent↗
PubMed1983

Elimination of cefroxadine (CGP-9000) from patients undergoing dialysis.

The pharmacokinetics of cefroxadine was studied in 17 patients with terminal renal impairment, 10 of whom were undergoing 5 h dialysis sessions. The antibiotic was administered as a single oral dose of 500 mg. Cefroxadine followed a single compartment open kinetic model. During the interdialysis period in patients with terminal renal impairment, an average Cmax of 26.59 micrograms/ml and a tmax of 3.65 h were reached, which are greater than in patients with normal renal function. The serum half-life was reduced from 23.55 h in the interdialysis periods to 3.40 h during the dialysis sessions. The average extraction coefficient was 0.249. It is recommended that a 500 mg dose cefroxadine should be administered at the end of each dialysis session if the interdialysis period is 48 h.

Adolescent↗
PubMed1983

Intrarenal blood flow distribution during adenosine-mediated vasoconstriction.

Intrarenal infusion of adenosine induces an initial vasoconstriction followed by a subsequent vasodilation. The intrarenal distribution of blood flow in the vasoconstriction phase is unknown. The present study was undertaken to assess the effect of intrarenal infusion of adenosine on intracortical distribution of renal blood flow during both the vasoconstriction and vasodilation phases. Renal blood flow distribution was measured with radiolabeled microspheres in anesthetized sodium-depleted dogs before and during the early vasoconstriction phase and the late vasodilation phase of intrarenal infusion of adenosine. During the vasoconstriction phase, there was a uniform decrease in blood flow in each renal cortical zone. In the late phase of adenosine infusion, there was a significant increase in deep cortical flow without significant changes in superficial cortical flow compared with control. The effects of adenosine were also compared with those exerted by norepinephrine in which decreased blood flow was demonstrated in all zones. We conclude that the vasoconstrictor phase of adenosine infusion is characterized by a uniform reduction of renal blood flow to all cortical zones, whereas the vasodilator phase is characterized by a selective deep cortical vasodilation.

Adenosine↗
PubMed1983

Influence of type of dialyzer on the pharmacokinetics of amikacin.

The pharmacokinetics of amikacin was studied in 18 patients with terminal renal impairment (Clcr less than 5 ml/min during the course of 4-5 h hemodialysis sessions using four different kinds of dialyzer: RP 6, RP 514, Dialix, and Ultra Flo II. All patients received a single dose of 7.5 mg amikacin/kg body wt. at the beginning of the dialysis session. The type of dialyzers influences the serum half-life, the extraction coefficient, and the percentage of dose extracted during dialysis. A linear relationship was established between the percentage of the dose extracted by dialysis and the dialysis clearance of the antibiotic.

Adolescent↗
PubMedDate not supplied

Focal segmental glomerular sclerosis in three generations of a single family.

We studied members of three generations of a family presenting a nephropathy characterized by proteinuria, occasional microscopic hematuria, progressive deterioration of renal function and an autosomic dominant hereditary pattern. In seven percutaneous needle biopsies, examination by light microscopy showed findings compatible with Focal Segmental Glomerulosclerosis (FSGS) in six patients and Focal Global Glomerulosclerosis (FGG) in one case. Deposits of immunoglobulins IgM, IgA and C3 following mesangial and peripheral distribution were observed. According to electron microscopy, the basal membrane was unchanged though electron dense deposits were found at subendothelial, subepithelial and mesangial locations.

Adolescent↗