Insulin inhibits voltage-dependent calcium influx into rod photoreceptors

Insulin inhibits the ERG b-wave and modulates L-type calcium currents (I(Ca)) in various preparations. We therefore examined insulin's effects on I(Ca) and depolarization-evoked [Ca2+]i increases in rod photoreceptors. Insulin inhibited I(Ca) and caused a dose-dependent reduction in the depolarization-evoked Ca2+ influx with an EC50 of 2.1 nM. Tyrosine kinase inhibitors, lavendustin A (100 nM) and genistein (10 microM), prevented insulin from reducing the depolarization-evoked Ca2+ increase in rods. Their less active analogues, lavendustin B and daidzein, had similar effects. An insulin receptor-specific tyrosine kinase inhibitor, HNMPA-(AM)3 (50 microM), prevented insulin (30 nM) from reducing the depolarization-evoked Ca2+ increase in rods. The results suggest that insulin inhibits Ca2+ influx through voltage-dependent I(Ca) in rod photoreceptors via tyrosine kinase activity.     

Toxic epidermal necrolysis treated with intravenous high-dose immunoglobulins: our experience

BACKGROUND: Toxic epidermal necrolysis (TEN) is a rare severe acute exfoliative drug-induced skin disorder which has recently been ascribed to alterations in the control of keratinocyte apoptosis, mediated by an interaction between the cell surface death receptor Fas and its respective ligand. A therapeutic approach with intravenous immunoglobulins (IVIG) associated with pulse methylprednisolone, based on the inhibition of Fas-mediated keratinocyte death by naturally occurring Fas-blocking antibodies included in human immunoglobulin preparations, has produced good preliminary results. OBJECTIVE: To analyse the efficacy of IVIG in the treatment of TEN. Patients: Nine patients with erythematous body surface area ranging from 38 to 85% and dermo-epidermal detachment from 4 to 37% were treated. RESULTS: Eight patients were healed and 1 died of septic shock and multiple organ failure. Interruption of further epidermal detachment occurred after an average of 4.8 days from the onset of IVIG therapy. Complete wound healing occurred after an average of 12 days. Concerning complications, 3 out of 8 surviving patients had acute respiratory failure requiring mechanical ventilation and 1 acute renal failure was treated with dialysis. Late sequelae were limited to dyschromia and nail dystrophies. No hypertrophic scars were observed. CONCLUSION: IVIG therapy represents a safe and valid approach for TEN.     

Outbreak of poliomyelitis in Angola

Between January and June 1999, 1,100 suspected cases of poliomyelitis were reported in Angola. Poliovirus types 3 and 1 were isolated. Patients' ages ranged from 2 months to 14 years. Of the 588 patients whose vaccine status was known, 58 (9.9%) received >4 doses, 216 (36.7%) received 3 or 4 doses, 178 (30.3%) received 1 or 2 doses, and 136 (23.1%) had no history of vaccination. Civil conflict, economic decline, and crowded areas with scarce sanitation and poor water supply are the most important factors implicated in declining rates of routine vaccination, low population immunity, and intense wild poliovirus transmission. The socioeconomic situation and poor roads have created major difficulties for vaccination and surveillance. The Angolan outbreak has serious implications for the global eradication of poliomyelitis. Surveillance of acute flaccid paralysis remains essential in the assessment of strategies for eradication and interventions to interrupt wild poliovirus transmission.     

Siblings in foster care: Success and failure

This article reports on a retrospective study of 59 joint placements of siblings in foster homes, involving a total of 137 children. An overall picture is presented of the agencies' considerations in making these placements. The number of prematurely terminated placements in this group amounted to 14 (23.7%). Several factors that appear related to premature termination are discussed.Frits Boer is a university lecturer in the Department of Child and Youth Psychiatry at the University of Leiden in the Netherlands and works as a child psychiatrist at the Academic Center for Child and Adolescent Psychiatry Curium in Oegstgeest. Stella Spiering is developmental psychologist in Rijswijk, the Netherlands.     

Surgery for colorectal cancer guided by radiodetecting probe. Clinical evaluation using monoclonal antibody B72.3.

Radioactive antibodies that react with tumour-associated antigens to "tag" antigen-positive tumour cell deposits were given to 20 patients with primary or recurrent colorectal cancer. The tumour associated antigen TAG 72-specific monoclonal antibody B72.3 labelled with 125-Iodine was used, and the radioactivity in the tumour was sought during operation with a hand-held gamma detecting probe. Tumour was detected by the probe in 7 of 15 patients with primary cancer, with a mean tumour: normal tissue ratio of 3.9, and in 4 of 5 patients with recurrent disease, with a mean tumour: normal tissue ratio of 2.0. Immunohistochemical analysis of surgical specimens confirmed the results of the intraoperative detection. The incidence of TAG 72-positive tumours (11/20, 55%), detected by immunohistochemistry, was lower than the 80% in the other series, possibly because of sampling errors or because the cases studied were uncomplicated with small primary tumours. Results obtained with the probe were instrumental in modifying the operation in two of the four "positive" patients with recurrences, allowing the removal of tumour masses that would otherwise have been overlooked.     

Variations in oligodendrocyte-related gene expression across multiple cortical regions: implications for the pathophysiology of schizophrenia

The disconnectivity syndrome hypothesis of schizophrenia suggests that communication between multiple brain circuits and regions may be disrupted. Microarray studies analysed gene expression in 15 different brain regions derived from 13 persons with schizophrenia and controls. The superior temporal gyrus, cingulate gyrus and hippocampus evidence the greatest numbers of abnormally expressed genes. Gene ontology categorization suggested that gene classes associated with oligodendrocytes and myelin function were among the most profoundly affected. qPCR and additional microarray studies have validated these oligodendrocyte- and myelin-associated findings in independent cohorts. At least some of the affected genes are associated with the regulation of axoglial contacts, axon calibre and the integrity of functional elements involved in signal propagation. The confluence of emerging evidence shows that myelination abnormalities are major components of the neurobiology of schizophrenia and suggest that re-evaluation of some long-held hypotheses and beliefs regarding the biological substrates of schizophrenia may be warranted.     

Putting sleep apnea to rest. Tailored therapy reduces fatigue-related risks

Sleep apnea, the periodic cessation of breathing during sleep, is a common and underdiagnosed condition. Treatment can improve quality of life as well as reduce morbidity and mortality from sleep apnea-related hypertension, stroke, and traffic accidents. In this article, the authors discuss types of sleep apnea, diagnostic tools, and treatment strategies for both adults and children.     

Vascular endothelial growth factor and nitric oxide serum levels in arterial hypertension

Vascular endothelial growth factor (VEGF) is a specific mitogen for endothelial cells and an inducer of the angiogenic procedure. Endothelial nitric oxide (NO) is a potent vasodilator. Because both are implicated in vascular function, it is possible that they would be significantly affected in arterial hypertension. The aim of the study was the investigation of the levels of the two substances in blood serum and their potential relation in patients with untreated essential arterial hypertension compared to healthy individuals. VEGF levels were found 129.1 +/- 135.9 pg/mL in a group of 28 untreated hypertensive patients vs. 209.0 +/- 133.3 pg/mL in a group of 28 healthy individuals (p = 0.008). Nitrites and nitrates levels (as an indirect index of calculating NO levels) were also lower in hypertensive patients than in healthy individuals (19.8 +/- 9.7 micromol/L vs. 29.6 +/- 15.9 micromol/L, p = 0.014). A positive correlation between NOx (nitrites and nitrates levels) and VEGF was found in healthy individuals (r = 0.55, p = 0.003), but there was no correlation in hypertensive patients. The significant decrease of serum VEGF and NO in arterial hypertension and the existence of a correlation between the two substances in healthy subjects that did not exist in the hypertensive patients are findings that need evaluation.