Pyrosequencing allows the detection of emergent ganciclovir resistance mutations after HCMV infection.

Prenatally acquired human cytomegalovirus (HCMV) infection is the most frequent viral infection of newborns in developed countries. Virostatic therapy is accompanied by side effects and stepwise emergence of resistant virus variants. Different genotypic approaches show limited sensitivity in detecting on-growing minor resistant virus populations. Here, we demonstrate the superiority of pyrosequencing for the monitoring of mutant emergence. In a preterm baby born after 28 weeks of gestation and suffering from disseminated congenital HCMV infection, long-term control could not be achieved under ganciclovir/valganciclovir therapy and the infant died on the 113th day of life. Resistance-associated mutations in the HCMV UL97 gene were not detected by conventional DNA sequencing but postmortem pyrosequencing. Four different CMV variants carrying resistance-associated mutations each representing 11-17% of the total CMV population were found.

Expression of soluble Fas in the cerebrospinal fluid of preterm infants with posthemorrhagic hydrocephalus and cystic white matter damage.

Perinatal brain damage may result in impaired neurological development in extremely preterm infants. The underlying pathophysiological mechanisms are complex, and biomarkers of prognostic value are not available. The aim of this study was to analyze soluble Fas (sFas) concentrations in the cerebrospinal fluid (CSF) representative for involvement of apoptotic processes in preterm infants developing posthemorrhagic hydrocephalus (PHHC) and to link them to white matter damage (WMD) diagnosed by cranial ultrasound. A total of 29 preterm infants with PHHC were included in the study; 17 of them had signs of cystic WMD (cWMD) on ultrasound examinations. CSF samples were obtained at first ventriculostomy, and results were compared to those of a reference group of 24 preterm and term infants without neurologic diseases. sFas concentrations were elevated in CSF samples of PHHC patients compared to the reference group. In patients with cWMD, sFas concentrations were significantly higher than in patients without cWMD. These results indicate that apoptosis via the Fas pathway is involved in the pathogenesis of cWMD in the context of PHHC, and that sFas in the CSF may serve as a marker of cWMD development.

Retinal vessel pathologies in a rat model of periventricular leukomalacia: a new model for retinopathy of prematurity?

PURPOSE: To characterize concurrent retinal vessel pathologies reminiscent to retinopathy of prematurity (ROP) in a rat model of periventricular leukomalacia (PVL), in order to identify uniform damage pathways in both organs, the eye and the brain. METHODS: Ischemia was induced in Long Evans rat pups on postnatal day 6 (P6) with unilateral (left side) carotid ligation (UCL) followed by exposure to different oxygen concentrations. Four different groups were studied: group A, hypoxia/ischemia (UCL + 6% O2, 1 hour); group B, hyperoxia (80% O2, 24 hours); group C, hypoxia/ischemia + hyperoxia (UCL + 6% O2, 1 hour + 80% O2, 24 hours); and group D, normoxia. In groups A and C, both retinae were examined separately (left retina, group A [A-L], right retina, group A [A-R]; left retina, group C [C-L], right retina, group C [C-R]). Morphologic analysis of vessel development based on flatmounts and cryosections was performed at P11 and P21. Quantitative (q)PCR was performed at P7, P11, and P21 (VEGF-A164, HIF-1α, EpoR, TNFα, iNOS, BMP-9, and IGF-1). RESULTS: On flatmounts, distinct retardation in deeper vascular plexus development was observed, most prominent in A-L and C-L. Retinae of groups A-L and C-L displayed reduced capillary-free zones and an increased number of branching points at P11. Quantitative PCR analysis showed significantly different expression profiles of IGF-1 in A-L and B compared with D over the time course of the experiment. CONCLUSIONS: This is the first report on concurring damage to the retina that was evaluated in a rat model of white matter injury in the developing brain. The relatively mild damage to the retinal vessel system may represent the basis for a model of moderate forms of ROP and to study vascular remodeling.