Therapeutic drug monitoring of ganciclovir for postnatal cytomegalovirus infection in an extremely low birth weight infant: a case report.

BACKGROUND: Ganciclovir is a therapeutic choice for extremely premature infants with severe postnatal cytomegalovirus disease, but little is known about its optimal dose size and dosing interval for them. CASE PRESENTATION: We treated an extremely premature female infant with postnatal cytomegalovirus infection with intravenous administration of ganciclovir since 49 days of life (postmenstrual age of 31 weeks). After ganciclovir treatment was initiated at a dose of 5 mg/kg every 12 h, cytomegalovirus loads in the peripheral blood were markedly decreased. However, since plasma ganciclovir trough level was too high, the interval was extended to every 24 h. Subsequently, the trough level and the estimated 12-h area under the concentration-time curve (AUC0-12) were decreased from 3.5 mg/L to 0.3 mg/L and 53.9 mg · h/L to 19.2 mg · h/L, respectively, resulting in an exacerbation of viremia and clinical condition. Adjustment of dosing interval from 24 h to 12 h led to a peak level of 4.2 mg/L, trough level of 1.1 mg/L, and AUC0-12 of 31.8 mg · h/L, resulting in a marked suppression of viral load. CONCLUSIONS: Monitoring the therapeutic drug levels and cytomegalovirus loads is useful in obtaining a proper treatment effect and preventing overdosage during ganciclovir therapy in premature infants with postnatal cytomegalovirus infection.

SAMD9 mutations cause a novel multisystem disorder, MIRAGE syndrome, and are associated with loss of chromosome 7.

Adrenal hypoplasia is a rare, life-threatening congenital disorder. Here we define a new form of syndromic adrenal hypoplasia, which we propose to term MIRAGE (myelodysplasia, infection, restriction of growth, adrenal hypoplasia, genital phenotypes, and enteropathy) syndrome. By exome sequencing and follow-up studies, we identified 11 patients with adrenal hypoplasia and common extra-adrenal features harboring mutations in SAMD9. Expression of the wild-type SAMD9 protein, a facilitator of endosome fusion, caused mild growth restriction in cultured cells, whereas expression of mutants caused profound growth inhibition. Patient-derived fibroblasts had restricted growth, decreased plasma membrane EGFR expression, increased size of early endosomes, and intracellular accumulation of giant vesicles carrying a late endosome marker. Of interest, two patients developed myelodysplasitc syndrome (MDS) that was accompanied by loss of the chromosome 7 carrying the SAMD9 mutation. Considering the potent growth-restricting activity of the SAMD9 mutants, the loss of chromosome 7 presumably occurred as an adaptation to the growth-restricting condition.

Leigh syndrome with Fukuyama congenital muscular dystrophy: a case report.

We report the first case of Leigh syndrome (LS) with Fukuyama congenital muscular dystrophy (FCMD). A neonate suffered from lactic acidosis and subsequently presented with poor feeding, muscle weakness, hypotonia, cardiopulmonary dysfunction, and hydrocephalus. He died at 17 months. The findings of brain magnetic resonance imaging indicated some specific features of both LS and FCMD, and FCMD gene mutation was detected. Decreased mitochondrial respiratory complex I and II activity was noted. Mitochondrial DNA sequencing showed no pathogenic mutation. A case with complex I+II deficiency has rarely been reported, suggesting a nuclear gene mutation.

Reduced oxygen protocol decreases the incidence of threshold retinopathy of prematurity in infants of <33 weeks gestation.

BACKGROUND: The relationship between oxygen and retinopathy of prematurity (ROP) has been studied frequently, and a pulse oximeter has the potential to facilitate the control of oxygen fluctuation in neonates. The objective of the present study was to compare the incidence of threshold ROP (stage 3 requiring laser treatment and stage 4) in infants of <33 weeks gestation after implementing a new clinical O(2) management practice. METHODS: A retrospective study of data from the Kyoto First Red Cross Hospital neonatal intensive care unit (NICU) from 1 July 2004 to 31 October 2007 (closed 1 December 2006-30 March 2007 for reconstruction). A reduced oxygen protocol was implemented to maintain oxygen saturation (SpO(2)) values using a pulse oximeter between 88% and 92%. The incidence of threshold ROP in the earlier period (1 July 2004-31 December 2005) and the later period (1 January 2006-31 October 2007) were compared. RESULTS: The incidence of threshold ROP significantly decreased from 32.2% to 16.7%, after changing to the reduced oxygen protocol (P < 0.05). CONCLUSION: A significant decrease in the rate of threshold ROP in infants of <33 weeks gestation was observed after implementation of the new clinical O(2) management practice.

Stimulation of N-methyl-D-aspartate (NMDA) receptors inhibits neuronal migration in embryonic cerebral cortex: a tissue culture study.

We performed a tissue culture study using embryonic rat brain to investigate the effect of excessive stimulation of NMDA receptors on neuronal migration in the cerebral cortex. After progenitor cells in the ventricular zone of E16 cerebral cortex explants were labeled with [(3)H]thymidine, the explants were cultured for 48 h, and distributions of labelled cells were evaluated autoradiographically. Stimulation of NMDA receptors by NMDA and ibotenate, NMDA receptor agonists added to the culture medium in separate studies, caused percentages of labeled cells to decrease significantly in the intermediate zone and increase in the ventricular zone. The results suggest that in rat cerebral cortex, agonist stimulation of NMDA receptors inhibits neuronal migration.