Distinct patterns of glomerular disease in Lima, Peru.

AIM: We performed both a retrospective and prospective study to elucidate the types of glomerular diseases present in adults in Lima, Peru. MATERIAL AND METHODS: In the retrospective study, we analyzed 1,263 renal biopsies over a 10-year period (1985 -1995) that were processed at a central reference renal pathology laboratory in Lima. 101 cases were examined in the prospective study. RESULTS: The most common glomerular diseases observed were those due to systemic lupus erythematosus (30.2%), membranoproliferative glomerulonephritis (MPGN, 14.8%), and focal and segmental glomerulosclerosis (FSGS, 13.9%). Although mesangial-proliferative nephritis was observed in 9.5% of cases, IgA nephropathy was rare (0.9%). Examination of the year to year frequency showed that MPGN has tended to decrease in frequency with time whereas FSGS has been increasing. Although there is known to be a high frequency of infections in Peru, only 4.2% of the cases in the retrospective study were associated with infection. Furthermore, in the prospective study, only one case of hepatitis C and no cases of hepatitis B viral infection were detected, including in the 11 cases of MPGN observed. CONCLUSION: We conclude that the epidemiology of glomerular disease in Lima, Peru, is distinct from most areas of the world, but has similarities to certain regions in Africa, in that MPGN is common whereas IgA nephropathy appears to be rare. Further studies are necessary to elucidate the reasons why the patterns of glomerular disease are different from that observed in other parts of the world.

Clinicopathologic correlations in lupus nephritis in Lima, Peru.

BACKGROUND: We assessed whether immunohistologic markers for glomerular or tubulointerstitial injury might provide better correlations with ongoing renal function and disease activity as compared with the WHO classification or the NIH activity and chronicity indices in lupus nephritis. METHODS: Thirty-three patients with clinically defined systemic lupus underwent renal biopsy over a 1-year period at Hospital Loayza in Lima, Peru. Biopsy specimens were evaluated for macrophages, proliferating cells, alpha-actin expression, and type IV collagen deposition in both glomeruli and the tubulointerstitium and the results compared with the current WHO and NIH classifications in relation to the clinical presentation. RESULTS: Patients with WHO class IV lupus nephritis were more likely to have lower serum complements, greater proteinuria and hematuria, and worse renal function. An elevated NIH activity index correlated with microhematuria, proteinuria, and impaired renal function, whereas an elevated chronicity index correlated with renal function, hypertension, and microhematuria, but not with proteinuria. The presence of glomerular macrophages correlated with both glomerular alpha-actin expression and type IV collagen deposition, but did not correlate with renal function or proteinuria. In contrast, interstitial macrophages correlated not only with interstitial collagen deposition and myofibroblast accumulation, but also correlated with both renal function and the presence of nephrotic syndrome. CONCLUSIONS: Both the WHO classification and the NIH activity/chronicity indices correlate with clinical manifestations of lupus nephritis. While glomerular macrophage accumulation correlates with mesangial cell activation (alpha-actin expression) and collagen deposition, and interstitial macrophage accumulation correlates with interstitial fibroblast activation and collagen deposition, only interstitial macrophages correlate with renal function. Of particular interest will be future studies to determine whether these markers correlate with the prognosis.

Postnatal inositol levels in preterm infants.

OBJECTIVE: To measure plasma inositol levels in preterm infants fed formula containing inositol at levels close to those in human milk. STUDY DESIGN: Plasma inositol levels were measured in 72 preterm infants fed formula containing 1110 mumol/L inositol and in cord blood of 12 healthy term infants. Preterm infant plasma levels were measured four times: (1) within the first 7 days of life, (2) intermediate enteral feeding, (3) at hospital discharge, and (4) 2 months after hospital discharge. RESULTS: Inositol concentrations in term cord blood samples were significantly lower than in preterm initial feeding, intermediate feeding, and discharge samples. Initial concentrations in blood of preterm infants were higher than in all other groups, and were significantly lower among infants with gestational ages of 31 to 33 weeks compared with those of 28 to 30 or 31 to 33 weeks. Days of parenteral nutrition were a significant predictor of inositol levels in the full feeding sample, with lower levels associated with prolonged parenteral nutrition. Clinical outcomes were not related to plasma inositol levels. CONCLUSIONS: Feeding preterm formula with inositol levels close to those reported for human milk may not prevent the postnatal decline in preterm infant plasma inositol levels.

Pharmacokinetics of continuous infusion fentanyl in newborns.

Although fentanyl administration by continuous infusion in newborns during ventilatory support has increased, pharmacokinetic data are lacking. Our objective was to determine the pharmacokinetics of fentanyl continuous infusions for sedation/analgesia in newborns who had undergone mechanical ventilation. Fentanyl was administered per routine care in seven newborns who had undergone mechanical ventilation and had normal hepatic, renal, and cardiac function. Five blood samples were collected from each newborn's umbilical artery catheter. Sample 1 was obtained at > or = 36 hours after constant fentanyl was infused, and sample 2 was collected 12 hours later. Fentanyl was then discontinued and meperidine given. Additional samples were obtained 6, 12, and 24 hours after fentanyl was discontinued. Decanted plasma was stored at -20 degrees C until gas chromatography analysis was performed. Total body clearance (TBC), elimination half-life, and volume of distribution at steady state were determined. Patient weights were 1.88 +/- 1.12 kg (mean +/- SD) with postnatal age 16 +/- 9 days; the mean gestational age was 32 +/- 4 weeks. Mean final fentanyl dosage was 1.28 +/- 0.58 microgram/kg/hr (range 0.53 to 1.9 micrograms/kg/hr). Mean elimination half-life was 9.5 +/- 2.6 hours (range 5.7 to 12.7 hours), and volume of distribution at steady state was 17 +/- 9 L/kg (range 10.1 to 30.3 L/kg). Mean TBC was 1154 +/- 494 ml/kg/hr (range 565 to 2000 ml/kg/hr). Significant correlation between postnatal age and TBC occurred (r = 0.80; p = 0.03). Newborns were hemodynamically stable during the sampling period. We found an increased volume of distribution at steady state and prolonged elimination half-life compared with single-dose administration in newborns. TBC was similar to reported values for infants and young children but was higher than for older patients.

Phenoxybenzamine placental transfer during the third trimester.

OBJECTIVE: To report phenoxybenzamine placental transfer in the treatment of maternal hypertension secondary to pheochromocytoma. CASE SUMMARY: A 22-year-old woman diagnosed with pheochromocytoma was medically managed at 33 weeks gestation with oral phenoxybenzamine and labetalol until delivery 26 days later. To determine phenoxybenzamine placental passage, at the time of cesarean section simultaneous samples were obtained from the cord blood, maternal blood, and amniotic fluid. Additional blood samples were obtained from the newborn at 32 and 80 hours of life. Mean concentrations of phenoxybenzamine from cord and maternal plasma and in amniotic fluid were 103.3, 66, and 79.3 ng/mL, respectively; the newborn's plasma concentration at 32 hours of life was 22.3 ng/mL. At the time of delivery, the 2475-g male infant exhibited perinatal depression; mild transient hypotension was also noted for the first few days of life. DISCUSSION: The fetal-maternal plasma accumulation ratio of 1.6:1 indicates that at this gestational age after 26 days of therapy, the placental transfer of phenoxybenzamine occurs and is accompanied by accumulation in the fetal blood. CONCLUSIONS: Because of the placental transfer of phenoxybenzamine, mild perinatal depression and transient hypotension may occur in newborns of mothers receiving this medication. These newborns must be closely monitored during the first few days of life for respiratory depression and hypotension.

Threshold retinopathy of prematurity. Transition from cryopexy to laser treatment.

PURPOSE: The authors studied the effectiveness of laserpexy versus cryopexy for treatment of acute retinopathy of prematurity. METHODS: Seventy-six eyes in 41 patients were treated for acute retinopathy of prematurity from January 1991 to April 1994. RESULTS: Fifty-six eyes in 30 patients had zone 2 disease. Of these 30 patients, 11 received laser treatment and 20 received cryopexy treatment; there was at least one anatomically successful eye in each patient. Twenty eyes in ten patients had zone 1 disease. Seven patients had bilateral laser treatment. Three patients had bilateral cryopexy. In seven eyes with zone 1 disease, five were treated successfully with laser. None of the three eyes with zone 1 disease treated with cryopexy were successful. CONCLUSION: Laserpexy and cryopexy are of equal efficacy in treating zone 2 disease. There is a tendency that suggests that laserpexy is more effective than cryopexy in treating zone 1 disease. Diode and argon lasers are of equal efficacy in treating zone 1 disease.

Guidelines for continuous infusion medications in the neonatal intensive care unit.

OBJECTIVE: To present practical guidelines in tabular form for dosage, calculation, preparation, and monitoring of common medications administered by continuous infusion to neonatal intensive care patients. DATA SOURCES: Review articles and clinical trials were identified through a computer literature search with subsequent bibliography scanning. STUDY SELECTION: Articles selected for review were considered important contributions. DATA EXTRACTION: Data from human studies and review articles published in the English language were evaluated. DATA SYNTHESIS: In emergency situations, physicians and other healthcare providers caring for critically ill newborns often perform rapid calculations to determine the dosage and rate of continuous intravenous medication infusions. Because of the crisis situation, there is the potential for calculation errors. We compiled a concise table designed to provide a standardized method for the administration of emergency medications to neonatal intensive care patients. This table must be used in conjunction with clinical judgment and each medication infusion rate must be adjusted to the patient's clinical response and individual parameters. CONCLUSIONS: These guidelines help to minimize the volume of fluid needed for medication administration and facilitate the calculation, preparation, and timely administration of these medications, thus preventing errors that might occur in an emergency situation.

Cocaine and indomethacin: fetal anuria, neonatal edema, and gastrointestinal bleeding.

A case is reported in which exposure to cocaine and indomethacin was associated with development of fetal anuria, anasarca, and neonatal gastrointestinal hemorrhage. Cocaine and indomethacin may act synergistically to adversely affect renal, cardiovascular, and platelet function. It may be prudent to obtain a drug history and urine screen for cocaine before instituting indomethacin therapy for preterm labor or polyhydramnios.