摘要:

Our aim in this article is to propose a new hypothesis concerning the etiology of renal tubular acidosis (RTA) in that subgroup of patients who have the isolated, primary type of proximal RTA. We suggest that their underlying disorder is a more alkaline intracellular pH of the proximal convoluted tubule. Increased alkalinity of proximal tubular cells would explain the low rate of bicarbonate reabsorption per liter glomerular filtration and the decreased rate of ammonium excretion despite a low urine pH and the presence of chronic metabolic acidosis. Additional diagnostic tests to evaluate this hypothesis in this specific subgroup of patients with proximal RTA are also outlined.

ISSN:0250-8095    

DOI:10.1159/000167979

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

To investigate the pathogenetic constellation and its modification by calcium channel blockade in hypertension associated with chronic nonoliguric renal failure, blood pressure (BP), various pressor factors or correlates, cardiovascular responsiveness, and plasma atrial natriuretic peptide (ANP) were assessed in 15 hypertensive patients (serum creatinine 160–715 umol/l) before and after 6 weeks of intervention with the agent nitrendipine. On placebo, these patients had a lower plasma angiotensin II (Angll) clearance and higher values of supine plasma Angll, aldosterone, norepinephrine (NE), and heart rate than healthy humans. Acute responses of BP to Angll and of heart rate to isoproterenol were blunted in the patients (p < 0.05–0.001). Plasma ANP was elevated, correlated positively with systolic BP, and rose in response to NE pressor infusion (p < 0.05–0.001). Exchangeable sodium and blood volume did not differ significantly from normal values. Nitrendipine reduced the cardiovascular responses to Angll, NE, and isoproterenol and lowered supine BP from 173/102 + 5/2 to 146/81 ± 3/3 mm Hg and upright BP from 170/105 ± 5/2 to 145/86 ± 4/3 mm Hg (p < 0.05–0.001); except for slightly increased plasma Angll, the levels of other endocrine variables, exchangeable sodium, blood volume, and creatinine clearance were not significantly modified. Conclusions: Hypertension accompanying chronic nonoliguric renal impairment seems to be strongly Angll and probably also NE dependent. Circulating ANP levels are high in this setting. Calcium channel blockade with nitrendipine effectively reduces cardiovascular Angll and NE depende

ISSN:0250-8095    

DOI:10.1159/000167980

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

A poor prognosis was observed in patients who had end-stage renal disease (ESRD) as a result of systemic lupus erythematosus (SLE). This was true even in patients in whom SLE disease activity was transiently quiescent during the period of hemodialysis. Six of 9 patients with ESRD and SLE died with active SLE and/or sepsis 1–28 months following the onset of dialysis. In 5 of the 6 patients, acute inflammatory activity of SLE flared within 1 month of the patient’s death. Four patients died with superimposed sepsis, but only 2 of the 4 were receiving high-dose concomitant immunosuppressives for more than 1 week prior to death. Infected hemodialysis vascular access sites were implicated as the source of septicemia in 3 of 4 infectious deaths. The 3 surviving patients had minimal lupus activity prior to the development of ESRD, a possible marker for stability in SLE patients who require hemodialysis. Our results suggest that hemodialyzed lupus patients with nonautologous vascular access sites may be at continued increased risk for life-threatening inflammatory and septic complicati

ISSN:0250-8095    

DOI:10.1159/000167981

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

To verify if exogenous prostaglandin E2 (PGE2) is able to release antidiuretic hormone (ADH) and if endogenous angiotensin II plays a role in this eventual PGE2-induced stimulation of vasopressin, increasing doses of PGE2 were infused in 6 normal volunteers before (PGE2 study) and after the administration of 100 mg of captopril (captopril study). PGE2, even at an infusion rate of 40 and 60 ng/kg/min, did not modify blood pressure when it was infused alone; a significant fall of blood pressure was observed, in contrast, in the captopril study. PGE2 alone doubled the plasma levels of ADH. One hour after the subjects had been pre-treated with captopril, plasma levels of ADH fell by about 38%, then they increased by about 60% during the infusion of PGE2. These results suggest that in normal man endogenous angiotensin II is an important non-osmotic regulator of plasma ADH and that exogenous PGE2 can stimulate maximally the release of ADH only when the renin-angiotensin system is not impaired.

ISSN:0250-8095    

DOI:10.1159/000167982

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Plasma immunoreactive atrial natriuretic factor (irANF) levels and the effects of α-human ANF (α-hANF) infusion were investigated in 7 patients with liver cirrhosis and ascites. Under basal conditions, supine blood pressure (BP) averaged 136/76 ± 9/4 mm Hg (mean ± SEM). Plasma irANF concentrations (124 ± 33pg/ml)were higher (p < 0.01) than those in age-matched normal subjects (47 ± 5 pg/ml). Plasma renin activity (PRA 5.9 ± 2.2 ng/ml/h), aldosterone (18 ± 7 ng/dl) and norepinephrine (NE, 66 ± 5 ng/dl) levels were also elevated compared to the age-related normal range. α-hANF infusion for 60 min at 0.036 μg/kg/min decreased the mean BP (-14%; p < 0.05), increased PRA (+179%; p < 0.05) and plasma NE (+24%; p < 0.05). Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), diuresis and natriuresis were not modified. A subsequent 60-min infusion of α-hANF at 0.067 μg/kg/min produced a marked fall in mean BP (-26%; p < 0.001), hemoconcentration (hematocrit + 6%; p < 0.001) despite stable body fluid balance and a further increase in PRA (+350%, p < 0.005). GFR and ERPF were severely reduced (-55 and -56%, respectively; p < 0.001), while diuresis and natriuresis were not modified. Plasma aldosterone was unaltered during, but rose (+72%; p < 0.01) after the cessation of α-hANF infusion. Variations in natriuresis during α-hANF infusion correlated positively with BP (r = 0.47; p < 0.01), ERPF (r = 0.53; p < 0.01) or GFR (r = 0.51; p < 0.01). These findings indicate that in patients with liver cirrhosis and ascites, plasma levels of circulating irANF are increased. Infusion of α-hANF in pharmacological doses can produce unwanted falls in BP, ERPF and GFR which, in turn, preclude a therapeutically desired renal exc

ISSN:0250-8095    

DOI:10.1159/000167983

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Fifty consecutive patients underwent a modified open renal biopsy using bronchial forceps under general anesthesia. A small incision (2–3 cm) was made, and several small pieces of renal tissue (5–7) were excised in each case. Adequate tissue for diagnosis was obtained in 100% of the biopsies. Morbidity was minimal, and no deaths occurred as a result of biopsy. Traditionally, the open renal biopsy consists of a large incision (7–10 cm) with a deep wedge excision. It is significant that the modified technique provided a high tissue yield (the average number of glomeruli was 80) with few complications. This tissue yield was significantly higher than that usually seen with percutaneous needle b

ISSN:0250-8095    

DOI:10.1159/000167984

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

This study was designed to evaluate β-adrenergic responsiveness as assessed by the generation of cyclic AMP after the subcutaneous administration of epinephrine in 31 subjects: normal controls, patients with chronic renal insufficiency, hemodynamically stable patients on chronic acetate dialysis and hemodynamically unstable patients with acetate intolerance on chronic bicarbonate dialysis. As compared with controls, only unstable patients on bicarbonate dialysis presented impaired β-responsiveness, which, in turn, was acutely reduced only after acetate but not bicarbonate dialysis. Our results show that acetate dialysis impairs the β-adrenergic responsiveness and that the observed β-hyporesponsiveness in unstable patients with acetate intolerance may represent part of a broader spectrum of autonomic dysfunction which may develop in some patients on chronic hemodialy

ISSN:0250-8095    

DOI:10.1159/000167985

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

A prospective study was undertaken to assess the utility of the renal biopsy as a tool in the clinical practice of nephrology. Nephrologists performing this procedure were surveyed concerning prebiopsy diagnosis, plans for therapy and estimation of prognosis, before and after biopsy results were disclosed. On the basis of 108 specimens from both academic centers and community hospitals, clinical and pathological diagnoses differed in 63 % and therapeutic approach was altered in 34% of the cases. These results were greatest for nephrotic syndrome and for renal failure of rapid onset. The change in treatment was frequently of major consequence: decisions for the use of corticosteroids, cytotoxic agents and/or plasma exchange were altered based upon biopsy diagnoses. There were no differences either in diagnostic acumen or therapeutic approach between academic and community nephrologists. We conclude that renal biopsies are an important and frequently used part of the nephrologists’ approach to patient car

ISSN:0250-8095    

DOI:10.1159/000167986

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Foscarnet is a pyrophosphate analogue that has been successfully used in severe cytomegalovirus (CMV) infections. Little is known of the incidence and mechanisms of foscarnet-induced nephrotoxicity as most data comes from recipients of renal allografts or from patients with severe underlying disease or with other nephrotoxic drugs. We have retrospectively analyzed the evolution of renal function after 56 courses of foscarnet. In addition, we have prospectively studied the protective effects of hydration on foscarnet nephrotoxicity (2.5 liters of saline/day during the night before the foscarnet therapy and throughout the course of treatment). Foscarnet-induced acute renal failure was defined as a rise in serum creatinine of at least 25% from the basal value. An increase in serum creatinine occurred in 37 cases out of the 56 courses of foscarnet (66%). The mean serum creatinine prior to foscarnet was 80.5 ± 3.3 μmol/l and the mean increase was 190 ± 28.3 μmol/l (range 80–1,000). Peak serum creatinine was higher than 200 and 300 μmol/l in 16 and 13 patients, respectively. Kidney obtained at autopsy from a 30-year-old male with AIDS, CMV pneumonitis and acute renal failure secondary to foscarnet administration showed an extensive tubular necrosis. In the group which was prospectively hydrated only 1 patient had an acute renal failure. The mean serum creatinine at the peak (96 ± 4 μmol/l) and at the end of the treatment (83 ± 4 μmol/l) was significantly lower (p < 0.05) than in non hydrated patients. In conclusion, foscarnet is a highly nephrotoxic drug which induces acute tubular necrosis. Prehydration with 2.5 liters of isotonic saline throughout the course of foscarnet therapy almost completely abolishes its neph

ISSN:0250-8095    

DOI:10.1159/000167987

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Autopsy reports on 155 successive end-stage renal disease (ESRD) patients and 147 control patients without ESRD, matched for age, race and gender, were collected. Cystic transformation of the kidneys was noted in 58% of the ESRD patients and 13.6% of the control patients. There were 25 ESRD patients with renal adenoma and 3 with renal cell carcinoma. The single best predictor of cystic transformation or tumorous degeneration was patient’s age. A statistically significant association between cystic transformation and gender, as well as the cause of ESRD, was also found. In contrast to previous reports we were unable to document a strong association between the incidence of either cystic transformation or tumorous degeneration with the duration of dialysis, nor did these two parameters correlate with mode of dialysis. We suggest that cystic transformation of the kidneys in ESRD is related to age and renal failure per se, is not strongly associated with duration of dialysis and is independent of mode of dialysis. Concomitant tumorous degeneration was frequent, but this was usually an incidental autopsy finding. Renal malignancy was uncommon and metastases were absen

ISSN:0250-8095    

DOI:10.1159/000167988

出版商:S. Karger AG    

年代:1989

数据来源: Karger