Simultaneous medullary sponge and adult polycystic kidney disease: the need for accurate diagnosis.

Two cases of simultaneous medullary sponge and adult polycystic kidney disease developed in siblings. The diagnoses of polycystic kidneys were made by renal ultrasonography and medullary sponge kidney was diagnosed roentgenographically. The family history was markedly positive for "cystic" disease. Medullary sponge kidney might be a precursor of polycystic kidney disease in some instances, or, more likely, this represents two separate afflictions occurring in the same individuals. When large medullary sponge kidneys are encountered, the possibility of concomitant polycystic kidney disease should be entertained and investigated with a sonogram. While the prognosis of isolated sponge kidney is excellent, polycystic kidney disease eventually leads to hypertension and renal failure.

Changing patterns and outcome of acute renal failure requiring hemodialysis.

To identify factors that may explain the persistently high mortality of acute renal failure (ARF), we compared the cause, clinical course, and outcome of 55 consecutive patients with ARF who underwent hemodialysis (HD) from 1962 to 1969 with 46 similar patients from 1979 to 1981 at the same medical center. We noted an overall increase in mortality from 54.5% to 71.7%. There was an increase in the number of elderly patients developing ARF, but age per se did not influence survival. There was a significant increase in mortality in younger patients resulting from the severity of their underlying illness. We saw an increase in the number of complicating factors occurring at the onset of ARF that correlated with the increase in mortality. In survivors ARF was more prolonged in our most recent experience. The development of prolonged, complicated ARF and the poor survival seen in younger patients led to the increase in mortality in our patients.

The milk-alkali syndrome. A reversible form of acute renal failure.

The milk-alkali syndrome became rare with the advent of modern ulcer therapy with nonabsorbable antacids, histamine2 blockers, and sucralfate. An increased frequency of this syndrome seems likely with the growing popularity of the use of calcium carbonate as an antacid or as calcium supplementation to prevent osteoporosis. We treated five patients who had six episodes of the milk-alkali syndrome; four of these cases were diagnosed between 1990 and 1992. All patients were ingesting massive quantities of calcium and absorbable alkali and were unaware of the toxic effects of these compounds. All patients presented with the triad of hypercalcemia, metabolic alkalosis, and renal failure. All metabolic abnormalities were corrected, and renal function improved with appropriate supportive measures and cessation of calcium and alkali ingestion. In two patients, the renal failure was so severe that dialysis was necessary. In four patients, either the serum amino-terminal parathyroid hormone or 1,25-dihydroxycholecalciferol levels were appropriately decreased in response to hypercalcemia. The serum carboxy-terminal parathyroid hormone levels were increased because of renal failure. Since both physicians and patients are often unaware of the calcium and alkali content of many nonprescription medicines, the diagnosis of the milk-alkali syndrome, a reversible cause of renal failure, can be missed if a detailed history of such intake is not elicited. Measurement of the serum amino-terminal parathyroid hormone and 1,25-dihydroxycholecalciferol levels may help differentiate milk-alkali syndrome from primary hyperparathyroidism.

Curvularia geniculata fungal peritonitis: a case report with review of literature.

Peritonitis is the "Achilles heel" of patients on peritoneal dialysis. Fungal peritonitis though not that common is associated with increased morbidity and mortality. We report the first case in the literature of a patient who developed peritonitis caused by Curvularia geniculata. We discuss the reported cases of Curvularia lunata peritonitis in literature and emphasize the early removal of catheter and treatment with intravenous amphotericin B.

Is peritoneal dialysis a good option for black patients?

Blacks are less likely than whites to use peritoneal dialysis (PD) as the initial renal replacement therapy. The reason for the underusage of PD by blacks is unknown. In a cross-sectional multicenter trial, we studied peritoneal transport character, small-molecular-weight solute clearances, and nutritional status in 475 patients undergoing PD (168 whites, 192 blacks, and 115 Asians). The mean age of blacks undergoing PD was significantly younger than that of whites (47.6 +/- 14.7 v 58.2 +/- 16.7 years; P < 0.0001). Target Kt/V and weekly creatinine clearance (WCC) as defined by the Dialysis Outcome Quality Initiative Work Group was achieved by 62.5% of whites, 67.2% of blacks, and 54.8% of Asians (P = 0.05). Total protein (7.25 +/- 0.88 v 6.55 +/- 0.73 g/dL), albumin (3.72 +/- 0.57 v 3.55 +/- 0.53 g/dL), and lean body mass (LBM; 41.7 +/- 15.6 v 33.0 +/- 11.8 kg) were lower in whites compared with blacks (P < 0.001). Although the normalized protein catabolic rate (nPCR) was greater (0.82 +/- 0.24 v 0.90 +/- 0.32 g/kg/d; P = 0.04), total protein (6.24 +/- 0.85 g/dL) and serum albumin levels (3.36 +/- 0.52 g/dL) and LBM (30.1 +/- 8.0 kg) were significantly lower in Asians than blacks (P < 0.0001). The favorable anabolic response in blacks may partially be explained by a higher calorie intake in this group of patients (29.6 +/- 10.7 Cal/kg/d) compared with whites (22.4 +/- 6.8 Cal/kg/d) and Asians (23.9 +/- 9.8 Cal/kg/d; P = 0.03). Multiple regression analysis identified that black race and weight were positively associated, whereas dialysate/plasma creatinine ratio (D/P(Creat)) and age had a negative effect on serum albumin level. Follow-up data indicated that the Kt/V (2.09 +/- 0.50 v 2.39 +/- 0.56; P = 0.02) and WCC (60.8 +/- 4.3 v 70.2 +/- 7.3 L/1.73 m2; P = 0.02) increased significantly from baseline only in blacks. We conclude that PD is an ideal renal replacement therapy in at least a subset of blacks with end-stage renal disease.

Effects of diabetes mellitus and aluminum toxicity on myocardial calcium transport.

Diabetics have an increased risk of developing renal insufficiency, as well as congestive heart failure independent of coronary atherosclerotic or hypertensive heart disease. Aluminum toxicity is being recognized with increased frequency in patients with reduced renal function and aluminum accumulates to a greater degree in tissues of patients with diabetes. Studies in patients with end stage renal disease have implicated aluminum overload as a potential cause of reduced cardiac function. Since both diabetes and aluminum decrease the activity of (Ca + Mg)-ATPase, a key enzyme involved in myocardial calcium transport, the interaction of experimental diabetes mellitus and aluminum toxicity on myocardial sarcoplasmic reticulum calcium transport was investigated in rats. Aluminum alone had no effect on (Ca + Mg)-ATPase activity, while activities in both the diabetic ([DM]) and diabetic plus aluminum loaded ([DM + Al]) groups were significantly lower than controls ([C]). Oxalate-dependent calcium uptake in the [DM] rats was slightly, but not significantly lower than controls, however, uptake was markedly reduced in rats which were both diabetic and aluminum loaded. The calcium regulatory protein calmodulin was measured by a functional assay in the soluble fraction of myocardial tissue prepared from each of the four groups. Compared to [C], calmodulin activity was significantly reduced in both the [DM] and [DM + Al] groups but not affected by aluminum alone. These data indicate that diabetes mellitus is associated with decreased myocardial calmodulin activity that may contribute to reduced sarcoplasmic reticulum (Ca + Mg)-ATPase and calcium transport activities and that aluminium toxicity potentiates the adverse effects of diabetes on decreasing sarcoplasmic reticulum calcium uptake.

Type 3 membranoproliferative glomerulonephritis: clinicopathologic correlations and long-term follow-up in nine patients.

We studied the renal pathologic findings and results of long-term follow-up (four to 15 years; mean 7.8 years) in nine patients with type 3 membranoproliferative glomerulonephritis (MPGN). We selected these patients because biopsy specimens displayed extensive glomerular, subepithelial, electron-dense deposits, besides other changes characteristic of MPGN. We compared these patients with 14 others with type 1 MPGN similarly followed up for a period of 7.4 years. Patients with type 3 MPGN were older, had hypocomplementemia less often, and enjoyed a slightly better outcome. Although six patients with type 3 MPGN had the nephrotic syndrome, end-stage renal failure developed only in two, whereas it developed in five of the 14 patients with type 1 MPGN.

Comparison of intramuscular versus subcutaneous erythropoietin for the treatment of anemia in CAPD patients.

Recombinant human erythropoietin (rHuEpo) can be administered to continuous ambulatory peritoneal dialysis (CAPD) patients subcutaneously (SC), intravenously (IV), and intraperitoneally (IP). Subcutaneous rHuEpo is preferred in CAPD patients because of its ease of administration and favorable pharmacokinetics. The longer half-life of SC rHuEpo allows for one or two doses per week. Since SC rHuEpo can cause pain and local irritation at the injection site, the efficacy and safety of intramuscular (IM) rHuEpo were compared to SC rHuEpo in 6 random stable CAPD patients. The protocol in each subject consisted of a single weekly injection of IM rHuEpo for 3-6 months (period 1), crossover to SC rHuEpo for 3-6 months (period 2), and crossover to IM rHuEpo for 3-6 months (period 3). The rHuEpo dose was adjusted by protocol to achieve a target hematocrit of 30%-33%. Pain at the injection site was graded on a scale of 0-3. All patients preferred IM rHuEpo to SC rHuEpo because of less pain at the injection site. One patient tolerated IM rHuEpo for six months (period 1), then left the study after one month of SC rHuEpo because of ecchymoses and pain at the SC injection sites. In all patients, there was no significant difference in the dose of rHuEpo (U/kg/wk) during the three study periods.(ABSTRACT TRUNCATED AT 250 WORDS)

A 57-year-old man with bruising and joint pain.

The differential diagnosis for a 57-year-old man with joint pain, bruising, and diarrhea is discussed in the setting of a Clinical Pathological Conference at Louisiana State University Medical Center in Shreveport, La. The pathophysiology and etiology of malabsorptive states are presented.

A 38-year-old man with nephrotic syndrome, episodic fever and abdominal pain.

The differential diagnosis for a 38-year-old white man with a chronic fever associated with nephrotic syndrome is discussed in the setting of a clinicopathological conference at Louisiana State University Medical Center in Shreveport, Louisiana. The etiology and pathophysiology of fever-associated nephrotic syndrome are discussed.

A 65-year-old woman with heart failure.

The differential diagnosis for a 65-year-old woman with heart failure is discussed in the setting of a clinicopathological conference at Louisiana State University Medical Center in Shreveport. The discussion includes precipitating factors, pathophysiology, and etiologies of heart failure.

Association of various point mutations as risk factors for synthetic graft thrombosis in African American hemodialysis patients.

Single-nucleotide polymorphisms in the genes that code for coagulation factor V (factor V (Leiden)) and II (prothrombin G20210A), as well as the methyltetrahydrofolate reductase (MTHFR) have been implicated in the majority of cases of hereditary thrombophilia. In our hemodialysis patient population, comprised mainly of African Americans, we have seen a high incidence of early vascular access thrombosis without any identifiable predisposing factors. In some instances, there is recurrent access thrombosis that may be related to an inherited condition. In this study we evaluated the presence of these gene mutations and their association with increased risk of recurrent vascular access thrombosis in our hemodialysis patient population. Our results show that factor V Leiden and factor II prothrombin point mutations did not appear to increase the risk of vascular access thrombosis in African Americans with end-stage renal disease on hemodialysis. Patients heterozygous for the MTHFR gene, also did not show a significant increased risk for synthetic graft thrombosis.

Antibiotic lock technique for prevention of cuffed tunnel catheter associated bacteremia.

BACKGROUND: Central venous cuffed tunnel catheters are commonly used for short term or long term hemodialysis access. However, catheter-associated bacteremia is a common complication. It has been suggested that the addition of antibiotics to the catheter during the interdialytic interval results in a decrease in bacterial colonization and thereby a decrease in catheter associated infections. To test this hypothesis, a prospective, randomized study was performed comparing a gentamicin citrate mixture to standard heparin as the catheter lock. The effect of covering the catheter hub in a sterile bag on the infection rate was additionally tested. METHODS: From January 1999 to April 2000, all patients who underwent tunnel catheter placement or change (55 catheters) in the Nephrology Interventional Laboratory at Louisiana State University Health Sciences Center in Shreveport, were prospectively randomized as follows: group 1 (n=14): Antibiotic lock with tricitrasol (46.7%), gentamicin (40 mg/ml) and saline in a ratio of 1:5:5 and catheter hub covered with a sterile plastic bag after cleaning with a 10% povidone iodine solution; group 2 (n=22): Heparin lock and sterile plastic bag over catheter hub after cleaning with povidone iodine; and group 3 (n=19): Heparin lock alone. The primary end points of the study were catheter-associated bacteremia and thrombosis. Catheter loss due to access maturation, transplant or transfer were censored. RESULTS: There were a total of 4,805 at risk patient-days. The total number of catheter associated bacteremias were one in group 1, four in group 2 and four in group 3. The number of catheter associated bacteremias per 1000 patient-days in each group was 0.62, 3.05, and 2.11 respectively. The sixty day percent survival of catheters in each group was 74 +/- 12, 55 +/- 12 and 59 +/- 11 respectively. CONCLUSIONS: 1) Tricitrasol and gentamicin as an antibiotic lock reduced the incidence of catheter associated bacteremia; 2) Covering the catheter hub with a sterile bag did not provide an additional advantage; 3) The antibiotic lock improved overall survival of catheters.

Effect of 1,25-vitamin D and parathyroidectomy on the uptake of aluminum in bone of rats with renal insufficiency.

Excessive aluminum accumulation in bone is associated with abnormalities in bone formation and mineralization in man and animals. The factors that influence deposition of aluminum in bone are not well understood. In this study the influence of 1,25-vitamin D on bone aluminum accumulation was evaluated in aluminum-loaded parathyroidectomized and nonparathyroidectomized rats with renal insufficiency. All groups of aluminum-loaded rats receiving 1,25-vitamin D had less bone aluminum accumulation. This effect was not influenced by the presence of absence of parathyroid hormone. All rats administered 1,25-vitamin D had elevated serum calcium and depressed serum phosphorus levels and lower body weight compared to controls. The results ascribe a potential role for 1,25-vitamin D in the prevention of aluminum accumulation.