Expression of leukocyte differentiation antigens during the differentiation of HL-60 cells induced by 1,25-dihydroxyvitamin D3: comparison with the maturation of normal monocytic and granulocytic bone marrow cells.

1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] induces monocytic differentiation of the HL-60 leukemic cell line. The present study investigated whether and to what extent this differentiation resembles the normal maturation of monocytic cells in the bone marrow. Multidimensional flow cytometry was used to identify changes in antigen expression that occur in normal bone marrow cells at distinct stages of monocytic and granulocytic maturation. HL-60 cells were analyzed in the same manner after exposure to 1,25-(OH)2D3 to determine whether the hormone induces a similar sequence of phenotypic changes. In the leukemic cells, monocytic features were sequentially induced and several maturational steps could be resolved. CD14, CD32, CD53, CD15, CDw65, CD29, CD16, and CD66b were modulated in 1,25-(OH)2D3-induced HL-60 cells as in the normal monocytic maturational pathway. Differences were observed for CD15s and CDw17. The expression pattern of CD44 during differentiation of HL-60 cells resembled that in granulocytic cells. The results therefore suggest that 1,25-(OH)2D3 induces a differentiation program in HL-60 cells that in many ways resembles that of normal monocytic cells in the bone marrow but also carries elements of the granulocytic pathway.

Expression of cell surface antigens during the differentiation of HL-60 cells induced by 1,25-dihydroxyvitamin D3, retinoic acid and DMSO.

HL-60 cells were induced to differentiate by 1,25-dihydroxyvitamin D3, retinoic acid or DMSO. In order to investigate to which extent this maturation mimics the in vivo monocytic or myeloid differentiation, we compared induced HL-60 cells with peripheral blood monocytes and granulocytes by using a panel of mAbs directed against myeloid cell surface antigens. Upon exposure to 1,25-(OH)2D3, HL-60 cells acquired a differentiation phenotype close to that of mature monocytes. The changes in myeloid cell surface antigens induced by retinoic acid or DMSO paralleled the expression pattern of these molecules in normal granulopoiesis, although maturation was not achieved and partially defective.

Modulation of cell proliferation and cell cycle, and inhibition of cytokinesis by 1,25-dihydroxyvitamin D3 in C3H/10T1/2 fibroblasts.

The growth-modulating effects of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] were studied on three mouse embryo fibroblast cell lines. Concentrations ranging from 0.1 to 100 nM inhibited dose-dependently proliferation in the non-tumorigenic C3H/10T1/2 Cl 8 (10T1/2) and the chemically transformed C3H/10T1/2 Cl 16 (Cl 16) cells. The hormone had a biphasic effect on the transformed cell line C3H/10T1/2 TPA 482 (TPA 482) in which growth was stimulated by low concentrations. Exposure to 10 nM 1,25-(OH)2D3 for 5 days resulted in a 90% growth inhibition of 10T1/2 cells, and the hormone was 10 and 100 times less potent in Cl 16 and TPA 482 cells, respectively. The inhibition of cell replication was fully reversible on removal of the hormone. Treatment of 10T1/2 and Cl 16 cells with 10 nM 1,25-(OH)2D3 reduced the saturation density to 30 and 37% that of controls, respectively, suggesting an enhancement of cell-cell contact mediated growth inhibition. 1,25-(OH)2D3 inhibited cytokinesis in 10T1/2 cells, inducing the formation of binucleated cells. Flow cytometric studies showed that 1,25-(OH)2D3-treated cells accumulated in the Go/G1 phase while the number of cells in S phase decreased. This in vitro model system seems to be useful for studies of the molecular mechanisms of the growth modulating effect of 1,25-(OH)2D3.

Neurofibromatosis 2 phenotypes and germ-line NF2 mutations determined by an RNA mismatch method and loss of heterozygosity analysis in NF2 schwannomas.

We used a novel RNase cleavage assay (NIRCA) to screen for neurofibromatosis 2 (NF2) mutations in NF2 schwannomas. Mutations were found in tumors in 16 of 20 patients. Eleven patients (55%) had loss of heterozygosity or loss of one allele, indicating that the mutation was a germ-line mutation. The phenotypes of these patients were consistent with previous NF2 genotype-phenotype correlation studies: patients with nonsense mutations had severe phenotypes, whereas those with splice-site or missense mutations had milder and variable phenotypes. These results confirm the utility of NIRCA as a rapid and convenient method for screening for germ-line NF2 mutations.

Brainstem electronic implants for bilateral anacusis following surgical removal of cerebello pontine angle lesions.

The multichannel auditory brainstem implant (ABI) has been used successfully to treat deafness in individuals with neurofibromatosis type II. The device has been implanted in nearly 150 recipients worldwide, and clinical trials with the device are approaching completion. The implantation and fitting of the multichannel ABI differ significantly from cochlear implantation, and the processes are illustrated in a series of case studies. Performance data also are included from recipients with up to 7 years experience.

[Detection during pregnancy of massive fetomaternal transfusion. A life saved by adherence to a protocol]. / Dépistage en cours de grossesse d'une hémorragie foeto-maternelle massive. Une vie sauvée par un protocole.

A case of massive feto-maternal haemorrhage which was discovered by chance in the 34th week of pregnancy is described in detail. This case is characterised by: total absence of clinical, electrical and echographic abnormalities, a part from the fetus being very anaemic; the saving of the very anaemic newborn baby because of the performance of caesarean section; although the pregnant woman was Rh negative, giving her large doses of IgG and anti-D prophylactically seems to have protected her from Rh immunisation. The authors conclude with the special value that they have found using the Kleihauer test. This is a simple, reproducible, low-cost laboratory examination. They suggest that it should be used mainly in the last third of pregnancy and may be even routinely.

Effects of 1,25-dihydroxyvitamin D3 on transformed C3H/10T1/2 fibroblasts grown as multicellular spheroids.

We have previously shown that 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) is able to modulate proliferation of C3H/10T1/2 fibroblasts grown in monolayer cell culture. The aim of this study was to investigate the effects of the hormone in a 3-dimensional culture system, which is considered to better reflect the cellular environment that is found in vivo. Two transformed cell lines of C3H/10T1/2 fibroblasts (C116 and TPA 482) were grown as multicellular spheroids, whereas the nontumorigenic C3H/10T1/2 C18 cells failed to form spheroids. The hormone had no effect on spheroids made of TPA 482 cells but had a biphasic effect on C116 spheroid growth with stimulation at low and inhibition at higher concentrations. In C116 spheroids, 10(-8) M 1,25-(OH)2D3 induced complete arrest of spheroid growth. Light and electron microscopic studies and immunocytochemistry showed that 10(-8) M 1,25-(OH)2D3 induced morphological changes in C116 spheroids, with a marked reduction in expression of fibronectin, laminin and the gap junction protein connexin 43. These effects were followed by a loosening of the spheroid structure, detachment of viable cells, and finally disaggregation of the spheroids. The results of this study, together with the data previously obtained in monolayer cell cultures, indicate that the effects of 1,25-(OH)2D3 may be conditioned by the cellular environment. Therefore, the spheroid model is an interesting tool for investigation of the antineoplastic effect of the hormone.

[Nephronophtisis in a child whose father has isolated ocular involvement]. / Néphronophtise chez un enfant dont le père a une atteinte oculaire isolée.

The Senior and Loken's syndrome is a condition associating nephronophtisis and tapetoretinal degeneration. The case reported had a quite unusual transmission: isolated ophthalmologic impairment in the father, isolated renal impairment in the son. Thus, the genetic transmission of this syndrome is probably not univocal.

Reorganization of the cytoskeleton and morphological changes induced by 1,25-dihydroxyvitamin D3 in C3H/10T1/2 mouse embryo fibroblasts: relation to inhibition of proliferation.

The effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2 D3) on cell morphology, the cytoskeleton, and fibronectin were studied in three lines of C3H/10T1/2 mouse embryo fibroblasts in which the antiproliferative effect of the hormone had previously been investigated. We showed that 1,25(OH)2D3 induced morphological changes in the nontransformed C3H/10T1/2 Cl 8 cells, which flattened and spread out markedly. Visualization of actin and tubulin by immunocytochemistry disclosed a reorganization of the microfilament and microtubular systems. 1,25(OH)2D3 also induced an increase in cell-surface-associated fibronectin. These changes were only slight in the transformed cell line C3H/10T1/2 Cl 16 and absent in the transformed C3H/10T1/2 TPA 482 cell line. These effects were correlated with the growth inhibition induced by the hormone, and this suggests a possible relationship between the 1,25(OH)2D3-induced alterations of cell shape and of the cytoskeleton and the effects of the hormone on cell proliferation.

Effects of 1,25-dihydroxyvitamin D3 and retinoic acid on the proliferation and cell cycle phase distribution of neuroblastoma SK-N-SH cells.

The hormone 1,25-(OH)2D3 has been shown to modulate cell proliferation and induce differentiation in several normal and malignant cell lines. In this work, we examined the effect of the hormone on the neuroblastoma SK-N-SH cell line. The steroid did not influence cell growth and cell cycle distribution, while retinoic acid inhibited proliferation and induced an accumulation of the cells in the G0/G1 phase of the cell cycle. 1,25-(OH)2D3 did not alter cell morphology. The activities of the 1-alpha- and 24-hydroxylases were low and not regulated by the hormone. The level of the total 1,25-(OH)2D3 receptor was low. We conclude that the lack of effect of 1,25-(OH)2D3 on the SK-N-SH cell line is related to the low level of the 1,25-(OH)2D3 receptor.

[Enuresis nocturna--practical advice for examination and treatment]. / Enuresis nocturna--praktiske råd for utredning og behandling.

Children suffering from nocturnal enuresis have better self-esteem when they stay dry. A medical examination is necessary in order to exclude specific causes. The choice of treatment should be based on: motivation and age of the child, nocturnal polyuria versus bladder capacity, possibilities to borrow an alarm device, and follow-up. Informed choice treatment should be offered. Treatment with an alarm device and minimum standards are discussed. Desmopressin for short-term treatment or for three month periods are recommended for patient who respond to desmopressin. If organic causes are suspected, the child has diurnal incontinence symptoms, or does not stay dry in spite of the recommended treatment, referral to a paediatrician or a paediatric department is recommended. A better program for managing these patients at paediatric departments should be developed in collaboration with other specialists.

[Lipoid nephrosis: changes in proteinemia and albuminemia after resolution of proteinuria]. / Néphrose lipoïdique: évolution de la protidémie et de l'albuminémie après disparition de la protéinurie.

Changes in serum protein and albumin levels following resolution of proteinuria were studied in 67 children with nephrosis. These two parameters returned to normal only after the 21st day, i.e. well after the natriuretic crisis and resolution of edema. Our results are consistent with recent studies showing that the fluid and electrolyte changes seen in the urine at resolution of the proteinuria (increased diuresis and natriuresis) are not due to a return to normal of serum protein and albumin levels. They probably reflect correction of an intrarenal abnormality whose mechanism is unclear.

[Diagnosis and treatment of congenital hyperinsulinism--to Paris at any price?]. / Undersøkelse og behandling av barn med kongenitt hyperinsulinisme--til Paris for enhver pris?

BACKGROUND: Persistent hyperinsulinaemic hypoglycaemia of infancy (PHHI) is a hyperfunctional disorder of pancreatic insulin-producing cells with hypertrophic beta-cells present either focally or diffusely. With an estimated frequency of 1:50,000 live births, Norway will on average have one case per year. It is clearly difficult to maintain expertise in diagnostics and treatment with such a low incidence. MATERIAL AND METHODS: We report three Norwegian patients with PHHI who were successfully treated at Hôpital des Enfants Malades in Paris. RESULTS: Two patients were shown to have focal hyperinsulinism treated with partial pancreas resection. After follow-up of three and a half and two years respectively, these patients have normal glucose tolerance and exocrine pancreatic function. One patient with diffuse hyperinsulinism was operated with subtotal (90%) pancreatectomy. At 2.5-years follow-up this patient has slight glucose intolerance whereas her fasting blood glucose is low normal. The exocrine pancreatic function is normal. INTERPRETATION: Patients with PHHI should be referred to a centre where the possibility of focal hyperinsulinism can be thoroughly explored.