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Biomedical subjects

R Zani

Publications and source records attributed to R Zani.

11 recordsLinked to original sources
PubMed2001

Adequacy of dialysis reduces the doses of recombinant erythropoietin independently from the use of biocompatible membranes in haemodialysis patients.

BACKGROUND: The effect of the adequacy of dialysis on the response to recombinant human erythropoietin (rHuEpo) therapy is still incompletely understood because of many confounding factors such as iron deficiency, biocompatibility of dialysis membranes, and dialysis modality that can interfere. METHODS: We investigated the relationship between Kt/V and the weekly dose of rHuEpo in 68 stable haemodialysis (HD) patients (age 65+/-15 years) treated with bicarbonate HD and unsubstituted cellulose membranes for 6-343 months (median 67 months). Inclusion criteria were HD for at least 6 months, subcutaneous rHuEpo for at least 4 months, transferrin saturation (TSAT) > or = 20%, serum ferritin > or = 100 ng/ml, and haematocrit (Hct) level targeted to 35% for at least 3 months. Exclusion criteria included HBsAg and HIV positivity, need for blood transfusions or evidence of blood loss in the 3 months before the study, and acute or chronic infections. Hct and haemoglobin (Hb) levels were evaluated weekly for 4 weeks; TSAT, serum ferritin, Kt/V, PCRn, serum albumin (sAlb), and weekly dose of rHuEpo were evaluated at the end of observation. No change in dialysis or therapy prescription was made during the study. RESULTS: The results for the whole group of patients were: Hct 35 +/- 1.2%, Hb 12.1 +/- 0.6 g/dl, TSAT 29 +/- 10%, serum ferritin 204 +/- 98 ng/ml, sAlb 4.1 +/- 0.3 g/dl, Kt/V 1.33 +/-0.19, PCRn 1.11+/- 0.28 g/kg/day, weekly dose of rHuEpo 123 +/- 76 U/kg. Hct did not correlate with Kt/V, whereas rHuEpo dose and Kt/V were inversely correlated (r = -0.49; P < 0.0001). Multiple regression analysis with rHuEpo as dependent variable confirmed Kt/V as the only significant variable (P < 0.002). Division of the patients into two groups according to Kt/V (group A, Kt/V < or = 1.2; group B, Kt/V > or = 1.4), showed no differences in Hct levels between the two groups, while weekly rHuEpo dose was significantly lower in group B than in group A (group B, 86 +/- 33 U/kg; group A, 183 +/- 95 U/kg, P < 0.0001). CONCLUSIONS: In iron-replete HD patients treated with rHuEpo in the maintenance phase, Kt/V exerts a significant sparing effect on rHuEpo requirement independent of the use of biocompatible synthetic membranes. By optimizing rHuEpo responsiveness, an adequate dialysis treatment can contribute to the reduction of the costs of rHuEpo therapy.

Adult↗
PubMed2001

Direct effect of the correction of acidosis on plasma parathyroid hormone concentrations, calcium and phosphate in hemodialysis patients: a prospective study.

BACKGROUND: Metabolic acidosis contributes to renal osteodystrophy and together with hyperphosphatemia, hypocalcemia and altered vitamin D metabolism may result in increased levels of intact parathyroid hormone (iPTH) and metastatic calcifications. However, the impact of the correction of metabolic acidosis on iPTH levels and calcium-phosphate metabolism is still controversial. STUDY DESIGN: The effects of the correction of metabolic acidosis on serum concentrations of iPTH, calcium (Ca), phosphate (PO(4)) and alkaline phosphatase were prospectively studied. Twelve uremic patients on maintenance hemodialysis (HD) for 49 months (median; range 6-243 months) with serum bicarbonate levels < or =20 mmol/l were studied before and after 3 months of oral sodium bicarbonate supplementation. Predialysis serum bicarbonate, arterial pH, ionized calcium, plasma sodium, plasma potassium, serum creatinine, hemoglobin, K(t)/V, postdialysis body weight, predialysis systolic and diastolic blood pressure were also evaluated before and after correction. RESULTS: Serum bicarbonate levels and arterial pH increased respectively from 19.3 +/- 0.6 to 24.4 +/- 1.2 mmol/l (p < 0.0001) and 7.34 +/- 0.03 to 7.40 +/- 0.02 (p < 0.001). iPTH levels decreased significantly from 399 +/- 475 to 305 +/- 353 pg/ml (p = 0.026). No changes in total serum Ca, plasma PO(4), serum akaline phosphatase, K(t)/V, serum creatinine, hemoglobin, body weight, predialysis systolic and diastolic blood pressures were observed. iCa decreased significantly. CONCLUSIONS: Our study demonstrates that the correction of metabolic acidosis in chronic HD patients reduces iPTH concentrations in HD patients with secondary hyperparathyroidism possibly by a direct effect on iPTH secretion.

Acid-Base Equilibrium↗
PubMed2000

Cholesterol crystal embolism: A recognizable cause of renal disease.

Cholesterol crystal embolism, sometimes separately designated atheroembolism, is an increasing and still underdiagnosed cause of renal dysfunction antemortem in elderly patients. Renal cholesterol crystal embolization, also known as atheroembolic renal disease, is caused by showers of cholesterol crystals from an atherosclerotic aorta that occlude small renal arteries. Although cholesterol crystal embolization can occur spontaneously, it is increasingly recognized as an iatrogenic complication from an invasive vascular procedure, such as manipulation of the aorta during angiography or vascular surgery, and after anticoagulant and fibrinolytic therapy. Cholesterol crystal embolism may give rise to different degrees of renal impairment. Some patients show only a moderate loss of renal function; in others, severe renal failure requiring dialysis ensues. An acute scenario with abrupt and sudden onset of renal failure may be observed. More frequently, a progressive loss of renal function occurs over weeks. A third clinical form of renal atheroemboli has been described, presenting as chronic, stable, and asymptomatic renal insufficiency. The renal outcome may be variable; some patients deteriorate or remain on dialysis, some improve, and some remain with chronic renal impairment. In addition to the kidneys, atheroembolization may involve the skin, gastrointestinal system, and central nervous system. Renal atheroembolic disease is a difficult and controversial diagnosis for the protean extrarenal manifestations of the disease. In the past, the diagnosis was often made postmortem. However, in the last decade, awareness of atheroembolic renal disease has improved, enabling us to make a correct premortem diagnosis in a number of patients. Correct diagnosis requires the clinician to be alert to the possibility. The typical patient is a white man aged older than 60 years with a baseline history of hypertension, smoking, and arterial disease. The presence of a classic triad characterized by a precipitating event, acute or subacute renal failure, and peripheral cholesterol crystal embolization strongly suggests the diagnosis. The confirmatory diagnosis can be made by means of biopsy of the target organs, including kidneys, skin, and the gastrointestinal system. Thus, Cinderella and her shoe now can be well matched during life. Patients with renal atheroemboli have a dismal outlook. A specific treatment is lacking. However, it is an important diagnosis to make because it may save the patient from inappropriate treatment. Finally, recent data suggest that an aggressive therapeutic approach with patient-tailored supportive measures may be associated with a favorable clinical outcome.

Adult↗
PubMed1998

Correction of metabolic acidosis increases serum albumin concentrations and decreases kinetically evaluated protein intake in haemodialysis patients: a prospective study.

BACKGROUND: Metabolic acidosis in haemodialysis (HD) patients increases whole body protein degradation while the correction of acidosis reduces it. However, the effects of the correction of acidosis on nutrition have not been clearly demonstrated. STUDY DESIGN: In this study we have evaluated the effects of 3 months of correction of metabolic acidosis by oral sodium bicarbonate supplementation on protein catabolic rate (PCRn) and serum albumin concentrations in 12 uraemic patients on maintenance HD for at least 6 months (median 49 months; range 6-243 months). Pre-dialysis serum bicarbonate, arterial pH, serum albumin, total serum proteins, serum creatinine, plasma sodium, haemoglobin, PCRn, Kt/V, and TACurea, were evaluated before and after correction. RESULTS: Serum bicarbonate levels and arterial pH increased respectively from 19.3 +/- 0.6 mmol/l to 24.4 +/- 1.2 mmol/l (P < 0.0001) and 7.34 +/- 0.03 to 7.40 +/- 0.02 (P < 0.0001). Serum albumin increased from 34.9 +/- 2.1 g/l to 37.9 +/- 2.9 g/l (P < 0.01), while PCRn decreased from 1.11 +/- 0.17 g/kg/day to 1.03 +/- 0.17 g/kg/day (P < 0.001). No changes in Kt/V, total serum proteins, serum creatinine, plasma sodium, haemoglobin, body weight, pre dialysis systolic and diastolic blood pressure, and intradialytic weight loss were observed. CONCLUSIONS: Our data demonstrate that correction of metabolic acidosis improves serum albumin concentrations in HD patients. The correction of acidosis induces a decrease in PCRn values, as evaluated by kinetic criteria, suggesting that in the presence of moderate to severe acidosis this parameter does not reflect the real dietary protein intake of the patients probably as a result of increased catabolism of endogenous proteins. The correction of metabolic acidosis should be considered of paramount importance in HD patients.

Acidosis↗
PubMedDate not supplied

[Abdominal angiostrongyliasis: report of a potential autochthonous case from Rio de Janeiro].

We present the first, probably autocton, case of abdominal angiostrongyliasis in Rio de Janeiro State. The patient presented initially with fever of unknown origin and severe eosinophilia developing acute abdomen due to small bowel perfuration, peritonitis, hepatic necrosis and sepsis. At the laparotomy a segment of small bowel was ressected and a liver biopsy was performed. Histopatology revealed the presence of an intra-arterial nematode, eosinophilic arteritis and granuloma. It is discussed the clinicopathological aspects of this rare and potentially severe disease that has not an established drug treatment since oral anti-helmintics are contra-indicated. The authors emphasize the importance of avoiding indiscriminate use of oral anti-helmintic drugs based only in blood eosinophilia.

Adult↗