The differential expression patterns of messenger RNAs encoding K-Cl cotransporters (KCC1,2) and Na-K-2Cl cotransporter (NKCC1) in the rat nervous system.

Cation-chloride cotransporters have been considered to play pivotal roles in controlling intracellular and extracellular ionic environments of neurons and hence controlling neuronal function. We investigated the total distributions of K-Cl cotransporter 1 (KCC1), KCC2 (KCC2), and Na-K-2Cl cotransporter 1 (NKCC1) messenger RNAs in the adult rat nervous system using in situ hybridization histochemistry. KCC2 messenger RNA was abundantly expressed in most neurons throughout the nervous system. However, we could not detect KCC2 messenger RNA expression in the dorsal root ganglion and mesencephalic trigeminal nucleus, where primary sensory neurons show depolarizing responses to GABA, suggesting that the absence of KCC2 is necessary for this phenomenon. Furthermore, KCC2 messenger RNA was also not detected in the dorsolateral part of the paraventricular nucleus, dorsomedial part of the suprachiasmatic nucleus, and ventromedial part of the supraoptic nucleus where vasopressin neurons exist, and in the reticular thalamic nucleus. As vasopressin neurons in the suprachiasmatic nucleus and neurons in the reticular thalamic nucleus produce their intrinsic rhythmicity, the lack of KCC2 messenger RNA expression in these regions might be involved in the genesis of rhythmicity through the control of intracellular chloride concentration. The expression levels of KCC1 and NKCC1 messenger RNAs were relatively low, however, positive neurons were observed in several regions, including the olfactory bulb, hippocampus, and in the granular layer of the cerebellum. In addition, positive signals were seen in the non-neuronal cells, such as choroid plexus epithelial cells, glial cells, and ependymal cells, suggesting that KCC1 and NKCC1 messenger RNAs were widely expressed in both neuronal and non-neuronal cells in the nervous system. These results clearly indicate a wide area- and cell-specific variation of cation chloride cotransporters, emphasizing the central role of anionic homeostasis in neuronal function and communication.

Hypermagnesiuria in children with newly diagnosed insulin-dependent diabetes mellitus.

In newly diagnosed insulin-dependent diabetes mellitus, the mechanisms underlying the concomitant occurrence of magnesium deficiency and normal blood magnesium concentration are unknown. The renal handling of magnesium was, therefore, studied in 37 children with newly diagnosed insulin-dependent diabetes mellitus and in 13 controls. Circulating magnesium levels were similar in patients and controls (0.86 vs. 0.84 mmol/l). However, the urinary excretion of magnesium was significantly higher in patients (90.6 vs. 32.2 mumol/l GFR). In the patients a significant positive correlation was found between excretion of magnesium and glycosuria or blood hydrogen ion activity. It is concluded that osmotic diuresis and acidosis increase magnesium excretion in newly diagnosed diabetes mellitus.

Expression of functional nerve growth factor receptors in pancreatic beta-cell lines and fetal rat islets in primary culture.

Previous data demonstrated that one rat insulinoma cell line, RINm5F cells, which is a rat beta-cell line derived from a pancreatic tumor, express mRNA coding for both the low- and the high-affinity nerve growth factor receptors. Goals of this study were to extend our data to other beta-cell lines and fetal islets in primary culture and to study further the binding characteristics of nerve growth factor receptors on beta-cells. Northern blot analysis revealed that not only a panel of endocrine beta-cell lines (RINm5F, INS-1, beta-TC3) but also fetal rat islets in primary culture express mRNA coding for trk-A, which has been proposed to be the neuronal high-affinity nerve growth factor receptors. Reverse polymerase chain reaction followed by sequencing revealed that the sequence of trk-A receptor in RINm5F cells is identical to that of trk-A expressed in PC12 cells. The expression of the low-affinity nerve growth factor receptor was examined by Northern blot analysis that showed low-affinity nerve growth factor receptor to be expressed in RINm5F and INS-1 cell lines, in fetal rat islets in primary culture, but not in beta-TC3-cells. Binding experiments revealed the presence of low- and high-affinity nerve growth factor binding sites, identical to those described for PC12 cells, on RINm5F and INS-1 cells and only high-affinity binding sites on beta-TC3 cells. Exposure of all three beta-cell lines to nerve growth factor increased NGFI-A and c-fos mRNA steady-state levels, showing that these receptors are functional.(ABSTRACT TRUNCATED AT 250 WORDS)

Risks of alternative nutrition in infancy: a case report of severe iodine and carnitine deficiency.

A 7.5-month-old infant with failure to thrive, developmental delay, muscular hypotonia, a visible goitre and severe osteopenia is described. Laboratory examination revealed a markedly increased serum TSH with low free T4, severe iodine and carnitine deficiency. The infant was breastfed until the age of 2.5 months and was then given a mixture of almond extract in water. The mother is a strict vegan and the father a lactovegetarian. The nutritional intake of the child was severely depleted in calories (-46%), calcium (-73%) and iodine (-88%). The restrictive alternative nutrition was responsible for the various deficiency disorders.

Isolated growth hormone (GH) deficiency type IA associated with a 45-kilobase gene deletion within the human GH gene cluster.

A Turkish family of seven individuals (two parents and five offspring) is described in which three children presented with isolated GH deficiency type IA, as defined by Illig et al. The gene deletion responsible for the isolated GH deficiency was characterized by Southern blotting and hybridization analysis of genomic DNA using a 32P-labeled hGH cDNA clone as a probe. In the affected patients, a total of approximately 45 kilobases of DNA, encompassing the human (h) GH-1, human chorionic somatomammotropin-L (hCS-L), hCS-A, and hGH-2 genes, were deleted. The end points of the deletion lay within two regions of highly homologous DNA sequence situated 5' to the hGH-1 gene and 5' to the hCS-B gene. The retention of only the hCS-B gene was associated with normal weight and length at birth and normal postpartum lactation in the mother heterozygous for the deletion. The parents, who are consanguineous, both presented with a DNA restriction pattern consistent with heterozygosity for this deletion.

Prevalence of human growth hormone-1 gene deletions among patients with isolated growth hormone deficiency from different populations.

Familial isolated growth hormone deficiency type IA results from homozygosity for either a 6.7-kb or a 7.6-kb hGH-1 gene deletion. Genomic DNA was extracted from circulating lymphocytes of 78 subjects with severe isolated growth hormone deficiency (height less than -4.5 SD score) and studied by polymerase chain amplification and by restriction endonuclease analysis looking for gene deletions within the hGH-gene cluster. The individuals analyzed were broadly grouped into three different populations (North-European, n = 32; Mediterranean, n = 22; and Turkish, n = 24). Ten out of 78 patients studied presented with an hGH-1 gene deletion; eight out of these 10 showed a 6.7-kb gene deletion, the remaining two a 7.6-kb hGH-1 gene deletion. Five of the 10 subjects developed anti-hGH antibodies to hGH replacement followed by a stunted growth response. Family studies of the affected patients were performed, revealing consanguinity in all the families, and the corresponding heterozygosity for the deletion was present in each of the parents. The results of our study revealed a prevalence for an hGH-1 gene deletion in three out of 32 North-European, three out of 22 Mediterranean, and four out of 24 Turkish patients with growth hormone deficiency (height less than 4.5 SD score). These data are important for prenatal diagnosis of at-risk pregnancies and for families at risk for recurrence and underline clearly the fact that the hGH-I gene deletion represents a common cause for growth hormone deficiency associated with severe growth retardation (height less than -4.5 SD score).

Persisting renotubular sequelae after cisplatin in children and adolescents.

UNLABELLED: Information on persisting renal sequelae after cisplatin in children and adolescents is limited. Twelve patients aged 4-20 years had been treated with cisplatin and were healthy 4-43 months after stopping chemotherapy. Plasma creatinine, calcium, albumin and hydrogen ion concentration, plasma and urinary sodium, chloride, phosphate and urate, and urinary magnesium and potassium were comparable in patients and controls. However, mean calciuria, magnesemia and potassemia were significantly reduced and bicarbonatemia increased in the patients. Calciuria, magnesemia, potassemia and bicarbonatemia were normal in 3 patients only, calciuria was below -2 SD control in 9 patients, renal magnesium deficiency was demonstrated in 5 patients (all with hypocalciuria as well), and 4 patients presented with hypokalemic metabolic alkalosis (all with magnesium deficiency and hypocalciuria). CONCLUSIONS: (1) Renotubular dysfunctions persist very often after cisplatin; (2) hypocalciuria is more frequent than hypomagnesemia; (3) the most severe tubulopathy after cisplatin includes hypocalciuria, renal magnesium deficiency and hypokalemic metabolic alkalosis.

[An avoidable cause of parental anxiety and unnecessary medical workup: diaper crystals (pannolithiasis)]. / Eine vermeidbare Ursache von elterlicher Besorgnis und unnötigen medizinischen Abklärungen: Windelsteine (Pannolithiasis).

Five infants aged 6 to 23 months had a history of passing crystals in urine. They were not ill, but micturition was reported to be associated with pain in two of them. Physical examination was normal, and urinalysis and culture were negative. In one case we observed "jelly-like crystals" of about 2 mm diameter which dissolved spontaneously in tap water. When the parents were re-questioned it became evident that all used a new brand of highly absorbent diapers. "Jelly-like crystals" developed in our laboratory when the absorbent material of the new diapers was put in contact with urine or tap water. The new highly absorbent diapers help to keep the baby dry. However, "jelly-like crystals" may be observed and possibly alarm both parents and physicians. Information for parents and physicians may avoid unnecessary anxiety or medical workup.

Chronic renal magnesium loss, hypocalciuria and mild hypokalaemic metabolic alkalosis after cisplatin.

Renotubular handling of sodium, potassium (K) calcium (Ca), phosphate, hydrogen ions and glucose, and urinary concentrating ability were studied in three children (aged 8, 8.5, 11 years) with renal magnesium (Mg) loss, persisting for more than 2 years after discontinuation of cisplatin treatment for neuroblastoma. A group of healthy children served as controls. Besides renal Mg wasting, a clear-cut tendency towards reduced calciuria associated with normal or slightly elevated plasma Ca was observed. Plasma K tended to be low (3.4-3.7 mmol/l), and plasma chloride was normal. Plasma bicarbonate (HCO3) ranged from 24.9 to 27.8 mmol/l, and urinary pH was always less than 6.0, indicating a renal HCO3 threshold exceeding 24 mmol/l. Plasma creatinine levels, glucosuria and phosphaturia, and urinary concentrating capacity were adequate. Comparable features were found in three children (aged 4.5, 9, 13 years) with primary renotubular hypomagnesaemia-hypokalaemia and hypocalciuria. This study complements the picture of chronic cisplatin tubulopathy in childhood demonstrating that, apart from Mg wasting, a reduced Ca excretion, and a tendency to hypokalaemia and metabolic alkalosis exist. Thus cisplatin may induce renal functional damage identical to that found in primary renotubular hypomagnesaemia--hypokalaemia with hypocalciuria.