Hyperkalemic Distal Renal Tubular Acidosis in Salt-Losing Congenital Adrenal Hyperplasia

ABSTRACT. Functional indices of distal urinary acidification were assessed in two male infants, aged 1 and 3 months, with salt-losing congenital adrenal hyperplasia. In both cases the diagnosis was sustained by the presence of elevated plasma levels of 17-hydroxyprogesterone, hyponatremia, hyperkalemia, metabolic acidosis and increased plasma renin activity. Both patients were unable to lower urinary pH below 5.9 either during acute ammonium chloride-induced acidosis or after i.v. administration of furosemide. One patient also failed to decrease urine pH below 5.5 and to increase urinary potassium excretion during sodium sulfate infusion. Oral sodium bicarbonate loading was given to both patients but failed to induce a significant increase in the urine minus blood P_co2 gradient. This gradient remained low also after neutral phosphate administration. Repeated studies after acute administration of fludrocortisone in one case or after prolonged administration of hydrocortisone in the other resulted in complete normalization of all functional studies. We conclude that salt-losing congenital adrenal hyperplasia can lead to hyperkalemic distal renal tubular acidosis in early infancy. The defective renal secretion of hydrogen ion and potassium is probably related to the abolishment of the negative potential difference in the cortical collecting tubule induced by the impaired reabsorption of sodium.     

Surveillance of measles: A comparison of active and passive methods

Background: The Catalan Health Plan includes the eliminationof indigenous measles as one of its objectives for the year2000. Together with an adequate vaccination policy, epidemiologicalsurveillance is a critical component in this strategy. The objectiveof the study is to compare the utility of active and passivesurveillance methods in detecting and characterising cases ofmeasles. Methods: Active surveillance was carried out by epidemiologistswho revised hospital discharges and questioned the staff inhealth centres about cases and passive surveillance was carriedout by receiving physician's notification of cases. The studywas done throughout the whole territory of Catalonia in 1996.For each case, laboratory results, age, probable site of transmission,size of the region of origin and immunisation status were investigated.Results: One hundred and seventy-one cases were detected, ofwhich 96 (56.1%) were confirmed and 52 (30.4%) laboratory confirmed.The positive predictive values for passive and active surveillancewere 54.6% (95% Cl: 46.4–63.6) and 60.9% (95% Cl: 44.5–75.8)respectively. The proportion of patients under 15 years washigher in cases detected by passive surveillance than in thosedetected by active surveillance (OR=2.9 and 95% Cl; 1.3–7.0).The probable site of transmission was less frequently knownby passive surveillance than by active surveillance (OR=0.2and 95% Cl: 0.07–0.4). No association was found betweenthe method of surveillance and the size of the region or immunisationstatus. Conclusion: A reasonable strategy for measles surveillanceappears to be the individualised notification of the diseaseby physicians followed by surveillance activities directed atconfirming the case and identifying its origin.     

SOCIAL STATUS AND FOOD PREFERENCE IN SOUTHERN BRAZIL

The prestige value of food and food behaviors is a topic of inquiry that complements the study of nutritional aspects of food use. In this work, varying social groups in Brazil are examined with regard to their evaluation of the status of available foods, and in turn, the frequencies with which they consume high and low status foods. Ethnographic and structured interviews were used to collect data, with agreement among groups tested by using Cultural Consensus Modeling. It was found that most social groups had a distinct notion of what foods are prestigious, although the high consumption of these same foods did not necessarily follow.     

Independent risk factors for renal damage in a series of primary vesicoureteral reflux: A multivariate analysis

Aim:   The aim of this study was to investigate risk factors associated with different extents of renal parenchyma involvement in a paediatric series of primary vesicoureteral reflux (VUR).
Methods:   A total of 549 patients with VUR were analyzed. The variable of interest was renal scar, assessed by technetium-99m dimercaptosuccinic acid scan, and classified into three subtypes: focal scar, multiple cortical scarring and diffuse scars with a contracted renal unit. The multinomial regression model was applied to identify independent variables associated with each subtype of renal damage.
Results:   After adjustment, four variables remained independently associated with a contracted renal unit: reflux grades III–V (odds ratio (OR) = 9.7; 95% confidence interval (CI) = 4.1–21.0), age at diagnosis (OR = 3; 95% CI = 1.6–5.1), unilateral reflux (OR = 2.1; 95% CI = 1.2–3.8), and male sex (OR = 2; 95% CI = 1.1–3.8). Two variables were associated with multiple scars: reflux grades III–V (OR = 13.8; 95% CI = 7.4–26.0) and age at diagnosis (OR = 1.9; 95% CI = 1.2–3.0). Two variables were associated with a focal scar: reflux grades III–V (OR = 7.9, 95% CI CI = 3.8–16.4) and male sex as a protective factor (OR = 0.5; 95% CI = 0.25–1.0).
Conclusion:   Our findings suggest that the development of a contracted renal unit is probably due to congenital malformation, more commonly observed in male infants with high-grade reflux.     

Pitfalls of Programming Sensing Polarities Using the Coronary Sinus Lead in Biventricular Pacemakers

Knowledge of the available sensing polarities in biventricular pacemakers is necessary for appropriate troubleshooting and avoiding possible pitfalls of cardiac resynchronization therapy programming, as illustrated through this case presentation. (PACE 2011; 34:e22–e25)     

Can the individual calibration be modified when laser fluorescence method is used for caries detection?

International Journal of Paediatric Dentistry 2013; 23: 138–144 Background. Individual calibration (IC) for caries detection methods based on fluorescence is time‐consuming, especially for paediatric dentists, if the calibration has to be performed tooth‐by‐tooth. However, it is not clear how this calibration actually interfere in laser fluorescence (LF) readings. Aim. This in vivo study was to verify the influence of different modes of IC on laser fluorescence (LF) readings. Design. Ninety six occlusal and 95 buccal surfaces of 1st permanent molars were examined using LF device after IC performed on control (no IC), the examined teeth, a permanent incisor, a 1st primary molar or a 2nd primary molar. All modes of IC were performed in the same child. Wilcoxon test and Bland–Altman analysis were used to compare the readings. Intraclass correlation coefficients (ICC) were calculated. Results. Laser fluorescence readings without prior calibration were higher than readings performed after any mode of IC and resulted in different values of ICC. After other IC modes, the LF readings were statistically similar. Conclusion. The absence of IC influences LF readings and LF reproducibility, but different IC methods can be considered in clinical practice.     

Variability in the number of tests used in children with acute gastroenteritis in two hospitals

The objective of the study was to determine whether rates ofdiagnostic test use varied between one US and one Spanish hospital.Retrospective chart review in the hospital's emergency departments,recording patient and illness characteristics and laboratorytests were performed. Adjustment was performed by multivariatelogistic regression analysis. After controlling for patientand severity of illness, US children remained more likely toundergo more than one laboratory test [0R=4.8 (3.5–;6.6)]than Spanish children. It was concluded that physicians at theUS hospital ordered more tests than providers at the Spanishhospital when treating patients with comparable level of illness.Cross-national comparisons may be useful in efforts to identifyappropriate cost-effective care.     

Effect of maternal cholestasis on the kinetics of bile acid transport across the canalicular membrane of infant rat livers

A reversible impairment in the ability of the liver to secrete cholephilic compounds has been reported to exist in infant rats born from mothers with surgically induced complete cholestasis during the last third of the pregnancy. Canalicular plasma membranes (CPM) were purified from livers obtained from 4 and 8 week-old offspring of healthy or cholestatic rats. Using radiolabelled glycocholic acid (GC) and a rapid filtration technique, bile acid transport by CPM vesicles in the presence of 3 mM ATP plus an ATP-regenerating system was measured at varying substrate concentrations. Kinetic parameters were calculated by nonlinear regression analysis. Similar values for the apparent affinity constant (Kt) were found in all experimental groups (approximately 350 μM ). The value of the maximal velocity of the transport (V_max) was similar for CPM obtained from control animals at 4 or 8 weeks of age (approximately 1.5 nmol/20 s/mg protein). In the offspring of cholestatic mothers the V_max value was not different from that found in control animals as far as 4 week-old rats were concerned. However, V_max in the 8 week-old group from cholestatic mothers was two-fold higher than that found in the rest of the experimental groups. Thus, the efficiency of transport, defined as V_max/Kt, was very similar in all experimental groups, except in the group of 8 week-old offspring of cholestatic mothers, where this value was 60% higher. Isolated livers obtained from this group were able to secrete a tracer dose of radiolabelled GC (11.25 nmol) into bile significantly faster than isolated livers obtained from control animals of the same age (8 weeks). In sum, these results indicate that, in young infant rats (4 week-old), in which the maximal secretion rate for bile acids was reduced by maternal cholestasis during pregnancy, the kinetics of ATP-dependent bile acid transport across the canalicular membrane were not affected. By contrast, in older infant rats (8 week-old), in which the overall ability of the liver to secrete bile acids seems to be restored to normality, the efficiency of the canalicular transport system was actually enhanced. This suggests the existence of compensation at the level of the canalicular membrane transfer and thus that there is another hitherto unidentified mechanism involved in bile acid secretion.