Maternal cumulative exposure to extremely low frequency electromagnetic fields and pregnancy outcomes in the Elfe cohort.

OBJECTIVES: To study the relations between maternal cumulative exposure to extremely low frequency electromagnetic fields (ELF EMF) and the risk of moderate prematurity and small for gestational age within the Elfe cohort. METHODS: The Elfe study included 18,329 infants born at 33weeks of gestation or more in France in 2011 and was designed to follow the children until 20years of age. Gestational age and anthropometric data at birth were collected in medical records and small for gestational age was defined according to a French customized growth standard. During interviews, mothers were asked to report their job status during pregnancy. If employed, their occupation was coded according to the International Standard Classification of Occupations 1988 and the date on which they stopped their work was recorded. Cumulative exposure to ELF EMF during pregnancy was assessed, for both mothers who worked and those who did not during pregnancy, using a recently-updated job-exposure matrix (JEM). Cumulative exposure was considered as a categorical variable (<17.5, 17.5-23.8, 23.8-36.2, 36.2-61.6 or ≥61.6µT-days), a binary variable (<44.1 and ≥44.1µT-days) and a continuous variable. Associations were analyzed by logistic regression, adjusting for the mother's lifestyle factors, sociodemographic characteristics and some mother's medical history during and before pregnancy. Analyses were restricted to single births and to complete values for the pregnancy outcomes (n=16,733). RESULTS: Cumulative exposure was obtained for 96.0% of the mothers. Among them, 37.5% were classified in the 23.8-36.2µT-days category, but high exposures were rare: 1.3% in the ≥61.6µT-days category and 5.5% in the ≥44.1µT-days category. No significant association was observed between maternal cumulative exposure and moderate prematurity and small for gestational age in this exposure range. CONCLUSION: This large population-based study does not suggest that maternal exposure to ELF EMF during pregnancy is highly associated with risks of moderate prematurity or small for gestational age.

Serum parathyroid hormone levels and serum calcium levels from birth to senescence.

1. Calcium and immunoreactive parathyroid hormone (iPTH) levels were measured in sera of 1334 normal subjects ranging from newborn to over 80 years of age. Albumin was measured in samples from the population of adults, which was 80% white, 15% black and 5% oriental. 2. Serum calcium and iPTH levels in children tended to be higher in the first three years of age; no sex differences were noted. Values for serum calcium and iPTH were higher in children than in adults. 3. Serum calcium, iPTH and albumin showed more variation in groups of white, black and oriental women than in similar groups of men. In white females the mean serum calcium remained fairly constant until age 60, whereas in black women it rose steadily from age 20-29 until age 50-59. Serum iPTH levels were lower in black women than in white women and usually were not measurable in oriental women. 4. In men (white, black and oriental) there was a steady decrease in mean serum calcium with age, and iPTH levels were not different from those observed in white women. 5. Although the number of samples from oriental women was small, the serum calcium was consistently lower and serum albumin was constantly higher than in white or black women, and iPTH levels usually were unmeasurable.

Effect of diet on mucin kinetics and composition: nutrition and health implications.

The mucus gel covering the gut epithelium is in dynamic balance between synthesis and secretion of mucin from goblet cells and proteolytic and physical erosion that releases mucin into the lumen. In the lumen, mucin is partially protected from proteolysis by carbohydrate chains, and it contributes to endogenous protein reaching the ileum. Dietary components modulate the contribution of mucin to endogenous protein components and their qualitative composition. In addition, mucin plays a key role in gastrointestinal protection in association with the microflora. In this review, we will attempt to evaluate the consequences of dietary manipulation of mucin on gut health.

Effect of extracellular K+ on the intracellular free Ca2+ concentration in leech glial cells and Retzius neurones.

The effects of extracellular K+ on the intracellular free Ca2+ concentration ([Ca2+]i) of neuropile glial cells and Retzius neurones in intact segmental ganglia of the leech Hirudo medicinalis were investigated by using iontophoretically injected fura-2. In both cell types, an elevation of the extracellular K+ concentration ([K+]o) caused an increase in [Ca2+]i, which was blocked by Co2+, Ni2+ and menthol, whereas nicardipine, flunarizine, omega-conotoxin GVIA and omega-agatoxin IVA were ineffective. In Ca(2+)-free solution, the K(+)-induced [Ca2+]i increase was largely suppressed in neuropile glial cells and completely abolished in Retzius neurones. The results indicate that the K(+)-induced [Ca2+]i increase was mainly due to Ca2+ influx through voltage-dependent Ca2+ channels. The Ca2+ channels of the two cell types were activated at different membrane potentials but at the same [K+]o. In both cell types, the recovery from a K(+)-induced [Ca2+]i increase was unaltered in Na(+)-free solution, indicating that active Ca2+ transport across the plasma membrane is mediated by Na(+)-independent mechanisms.

How to cheat in morphology: the renal ultrafilter.

It is easy to distort the "truth" in morphological reports in order to confirm a previously established dogma by selecting from a field of view only such details which are in accordance with the dogma and by ignoring parts contradictory to it. The renal corpuscle is used in this paper as an example and as a guide to the readers for future fraud.

Mitochondrial granulation in the proximal renal tubule in uremia.

Mitochondria contain electron-dense particles, partly composed of an amorphous form of calcium phosphate. We have used electron microscopy from percutaneous renal biopsy material to analyze mitochondrial granulation in the proximal renal tubule of nonuremic and uremic children. Based on a technique of cutting mitochondria from ten electron micrographs per biopsy, counting the granules in each mitochondrion and weighing the paper, we found that mitochondria of nonuremic children averaged 23.7 +/- 1.2 granules/g paper while uremic children had only 11.8 +/- 1.1 granules/g. The number of granules per gram was unrelated to the serum calcium phosphate solubility product. A significant decrease in calcium granulation in uremia can also be produced experimentally in rats. Control rats averaged 14.7 +/- 1.5 granules/g, while rats made uremic by partial nephrectomy had 6.0 +/- 0.7 granules/g. Treatment of uremic rats with a pharmacological dose of vitamin D restored granulation to normal within 24 h. The significant decrease in calcium phosphate granulation in the renal proximal tubule in uremic children and in experimental animals is probably related to the documented loss of 1 alpha-hydroxylation of vitamin D in uremia.

Glomerular basement membrane attenuation in familial nephritis and "benign" hematuria.

Lamination of the basement membrane has been considered to be the lesion characteristic of familial nephritis and attenuation to be the lesion of "Benign" familial hematuria. Electron micrographs were reviewed of 57 children who had renal biopsies for persistent hematuria. Attenuation or lamination of the glomerular capillary basement membrane was found in each. Twenty of the 57 children had familial nephritis; 20 had familial hematuria; and 17 had no involved relatives. Follow-up data were available for 14 of 20 children with familial nephritis, 12 of 20 with familial hematuria, and 12 of 17 with sporadic hematuria for 13.6 +/- 6.3, 6.7 +/- 4.6, and 7.0 +/- 4.8 years, respectively, after discovery of hematuria. Five children developed end-stage renal disease: three with familial nephritis, one with familial hematuria, and one with sporadic hematuria. Only two no longer had hematuria. Attenuation of the glomerular capillary basement membrane was seen in every biopsy, whereas lamination was not. Because hematuria and ultrastructural abnormalities were findings shared by all the children, we suggest the possibility that familial nephritis, and familial or sporadic hematuria as defined in this study, may be variations in a spectrum of inherited abnormality or abnormalities in the formation of the glomerular capillary basement membrane.

Analysis of selected plasma constituents in continuous ambulatory peritoneal dialysis effluent.

Patients maintained on continuous ambulatory peritoneal dialysis (CAPD) lose plasma constituents into the dialysis effluent. We have analyzed 24-hour CAPD effluents for selected components--total protein, a typical glycoprotein (alpha 1-acid glycoprotein), a typical lipoprotein (high density lipoprotein), and glycosaminoglycans. Our findings suggest that the plasma constituents found in CAPD effluent are similar to those found in urine from nephrotic patients. The loss of one or more of these plasma constituents into the dialysis solution may be linked to the hypertriglyceridemia observed in these patients.

Antibiotic-associated interstitial nephritis and nephrotic syndrome.

The combination of interstitial nephritis and minimal-change nephrotic syndrome has been well described in adults receiving nonsteroidal anti-inflammatory agents. The association of interstitial nephritis and minimal-change nephrotic syndrome has recently been described in 1 adult patient receiving ampicillin and in 1 patient receiving rifampin. We describe an 8-month-old child who developed reversible interstitial nephritis and minimal-change nephrotic syndrome while taking antibiotics.

Naproxen nephrotoxicity in a 2-year-old child.

The development of acute renal failure and interstitial nephritis due to therapeutic doses of nonsteroidal anti-inflammatory drugs has been documented repeatedly in adult patients but is rare in children. We report the occurrence of this complication in a child. Acute renal failure and hyperkalemia developed in a 2-year-old boy with juvenile rheumatoid arthritis after one month of naproxen sodium therapy. The evidence of renal toxic effects became manifest after an episode of dehydration. A percutaneous renal biopsy specimen revealed interstitial nephritis. The patient recovered promptly after withdrawal of the drug.

Familial hypophosphatemic rickets: bone mass measurements in children following therapy with calcitriol and supplemental phosphate.

Familial hypophosphatemic rickets is characterized by defective skeletal mineralization resulting in abnormal growth and development. The pathologic and radiologic correlates of this syndrome have been given some investigation, but the effect of this mineralization defect on bone mineral density has not been adequately assessed. We measured axial and appendicular bone mineral in 17 children (mean age 5.59 +/- 4.87) with familial hypophosphatemia at baseline and at 6-month intervals after initiation of therapy with vitamin D3 (calcitriol) and phosphate supplementation. Noninvasive quantitative techniques included single photon absorptiometry (SPA) of the radius, combined cortical thickness (CCT) of the second metacarpal, and quantitative computed tomography (QCT) of vertebral trabecular bone. Thoraco-lumbar and hand/wrist radiographs were qualitatively assessed for the prevalence and severity of osteosclerosis, rickets, and other parameters indicative of metabolic bone disease as well as skeletal age. Quantitative determinations of bone mineral by each technique were compared with normal values for age and sex, and individual standardized scores (z-scores) were calculated at each measurement interval. Standard scores were also calculated for bone age-adjusted mineral values. At baseline, spinal trabecular bone by QCT was not significantly different from normal values; however, measurements of peripheral cortical bone by either SPA or CCT were significantly lower than values for normal children of the same age and sex (P = 0.05 and P = 0.01, respectively). Following therapy with calcitriol and phosphate, peripheral bone mass was not shown to improve significantly when contiguous standard scores were compared even when values were adjusted for bone age.(ABSTRACT TRUNCATED AT 250 WORDS)

Intellectual development of children with renal insufficiency and end stage disease.

Sixty six pediatric nephrology patients, age 6 months to 20 years, were given individual psychometric tests of intelligence two or more times during the course of treatment; 24 were retested within the stage of conservative management, dialysis or post-transplantation, 42 were retested between those stages. The first IQ scores ranged from three standard deviations below the test mean of 100 to two above (first sample mean 85.91). The second mean IQ was significantly higher (91.96). Paired t tests showed that significant increases in mean IQ scores occurred between the pre- to post-transplantation stages of treatment. No significant changes occurred within stages or between conservative management and dialysis. Equivocal changes existed between dialysis and transplantation. Four patients with prolonged central nervous system complications and serious family problems had scores which declined more than one standard deviation. Issues related to age, medical condition, socioeconomic status, and cohort changes were evaluated.

Disparate effects of vitamin D treatment upon mitochondrial granulation in proximal and distal renal tubule.

The distribution of calcium phosphate granules in mitochondria of proximal and distal renal tubules of nonuremic and uremic children was analyzed by electron microscopy of material obtained by percutaneous kidney biopsy. Although distal tubule had fewer granules/mitochondrion than proximal tubule, uremia induced a significant drop (50%) in both, related to an increase in mitochondria containing O granules and a decrease in mitochondria with 2+ granules. The decrease observed in uremic children was reproduced experimentally by partial nephrectomy in rats. Uremia resulted in a 58% decrease of calcium phosphate granules in rat proximal tubule while a smaller but significant decrease (36%) occurred in distal tubule. Vitamin D deficiency in rats was associated with greatly decreased granulation in proximal tubule (80%) whereas distal tubule was less severely affected (36%). Supplementation of vitamin D to uremic rats restored mitochondrial granulation to normal in proximal tubule in 24 hr, but had no effect in distal tubule since the number of granules/mitochondrion, 0.5 +/- 0.1, remained statistically similar to that of untreated animals. Granulation in both proximal and distal tubule of uremic rats was unaffected by parathyroid hormone administration. Since restoration of granulation occurred only in proximal tubule, the defect in uremia which can be overcome by vitamin D treatment appears localized at the level of the proximal tubular cell membrane, indicating an action of vitamin D on calcium and/or phosphorus translocation into the proximal tubule.

Somatomedin in children with chronic renal insufficiency - relationship to growth rate and energy intake.

The relationship of energy intake, growth rate and serum concentration of somatomedin-A was evaluated in eighteen children with chronic renal insufficiency. Serum concentrations of somatomedin-A were found to be 0.84 micro/ml in normal children and were elevated to 3.06 micro/ml in children with chronic renal insufficiency prior to dialysis (p less than 0.01). Somatomedin-A concentrations increased during chronic hemodialysis to 5.81 micro/ml and decreased to 1.59 micro/ml following successful renal transplantation (p less than 0.01). Serum concentrations of somatomedin-A correlated with residual glomerular filtration rates (r = -0.5), serum creatinine concentration (r = 0.59), and blood urea nitrogen (r = 0.6). Growth rates correlated with energy intake (r = 0.58) and somatomedin-A concentrations (r = 0.4) in the children with chronic renal insufficiency. Both energy intake and somatomedin-A increased significantly after one year of nutritional supplementation. Our findings are consistent with the hypothesis that somatomedin, like other polypeptide hormones, is elevated in uremia and that increased energy intake may affect the growth of children with chronic renal insufficiency by increasing somatomedin levels.

Treatment of end-stage renal disease in children: a 15-year experience.

From 1964-1979, 154 children 1 to 16 years of age with end-stage renal disease (ESRD) were treated in a regional pediatric dialysis and transplant program. The incidence of ESRD was 1.6 per million total population per year. The survival rate of children undergoing dialysis for an average of 10 months was 93%. After living donor kidney transplantation (LD), patients survival rates in 60 children were 89% at 5 years, 83% at 10 years, and 74% at 15 years. After cadaver donor kidney transplantation (CD), patient survival rates in 85 children were 70% at 5 and 10 years. LD kidney survival was 71% at 5 years, 55% at 10 years, and 40% at 15 years, whereas CD kidney survival was 43% at 5 years and 31% at 10 years. The survival of first and second transplants was similar. Patient and kidney survival have improved since 1972. The survival rate of 26 children 1 to 5 years of age was 46%, but patients with Wilms' tumor accounted for most of the deaths. We attribute these favorable long-term results in children to an integrated program of dialysis and transplantation with special pediatric facilities.