Dengue virus (DENV), a mosquito-borne flavivirus, is a major public health threat. The virus poses risk to 2.5 billion people worldwide and causes 50 to 100 million human infections each year. Neither a vaccine nor an antiviral therapy is currently available for prevention and treatment of DENV infection. Here, we report a previously undescribed adenosine analog, NITD008, that potently inhibits DENV both in vitro and in vivo. In addition to the 4 serotypes of DENV, NITD008 inhibits other flaviviruses, including West Nile virus, yellow fever virus, and Powassan virus. The compound also suppresses hepatitis C virus, but it does not inhibit nonflaviviruses, such as Western equine encephalitis virus and vesicular stomatitis virus. A triphosphate form of NITD008 directly inhibits the RNA-dependent RNA polymerase activity of DENV, indicating that the compound functions as a chain terminator during viral RNA synthesis. NITD008 has good in vivo pharmacokinetic properties and is biologically available through oral administration. Treatment of DENV-infected mice with NITD008 suppressed peak viremia, reduced cytokine elevation, and completely prevented the infected mice from death. No observed adverse effect level (NOAEL) was achieved when rats were orally dosed with NITD008 at 50 mg/kg daily for 1 week. However, NOAEL could not be accomplished when rats and dogs were dosed daily for 2 weeks. Nevertheless, our results have proved the concept that a nucleoside inhibitor could be developed for potential treatment of flavivirus infections.

Individuals with permanent neonatal diabetes mellitus usually present within the first three months of life and require insulin treatment. We recently identified a locus on chromosome 10p13-p12.1 involved in permanent neonatal diabetes mellitus associated with pancreatic and cerebellar agenesis in a genome-wide linkage search of a consanguineous Pakistani family. Here we report the further linkage analysis of this family and a second family of Northern European descent segregating an identical phenotype. Positional cloning identified the mutations 705insG and C886T in the gene PTF1A, encoding pancreas transcription factor 1alpha, as disease-causing sequence changes. Both mutations cause truncation of the expressed PTF1A protein C-terminal to the basic-helix-loop-helix domain. Reporter-gene studies using a minimal PTF1A deletion mutant indicate that the deleted region defines a new domain that is crucial for the function of this protein. PTF1A is known to have a role in mammalian pancreatic development, and the clinical phenotype of the affected individuals implicated the protein as a key regulator of cerebellar neurogenesis. The essential role of PTF1A in normal cerebellar development was confirmed by detailed neuropathological analysis of Ptf1a(-/-) mice.

Spondylocostal dysostosis (SD, MIM 277300) is a group of vertebral malsegmentation syndromes with reduced stature resulting from axial skeletal defects. SD is characterized by multiple hemivertebrae, rib fusions and deletions with a non-progressive kyphoscoliosis. Cases may be sporadic or familial, with both autosomal dominant and autosomal recessive modes of inheritance reported. Autosomal recessive SD maps to a 7.8-cM interval on chromosome 19q13.1-q13.3 that is homologous with a mouse region containing a gene encoding the Notch ligand delta-like 3 (Dll3). Dll3 is mutated in the X-ray-induced mouse mutant pudgy (pu), causing a variety of vertebrocostal defects similar to SD phenotypes. Here we have cloned and sequenced human DLL3 to evaluate it as a candidate gene for SD and identified mutations in three autosomal recessive SD families. Two of the mutations predict truncations within conserved extracellular domains. The third is a missense mutation in a highly conserved glycine residue of the fifth epidermal growth factor (EGF) repeat, which has revealed an important functional role for this domain. These represent the first mutations in a human Delta homologue, thus highlighting the critical role of the Notch signalling pathway and its components in patterning the mammalian axial

In spondylocostal dysostosis (SD), vertebral-segmentation defects are associated with rib anomalies. This results in short-trunk short stature, nonprogressive kyphoscoliosis, and radiological features of multiple hemivertebrae and rib fusions. SD can be familial, and both autosomal dominant and autosomal recessive (AR) inheritance have been reported, but no genes have been identified or localized for nonsyndromic SD in humans. We performed genomewide scanning by homozygosity mapping in a large consanguineous ARSD Arab Israeli family with six definitely affected members. Significant linkage was found to chromosome 19q13, with a LOD score of 6.9. This was confirmed in a second Pakistani family with three affected members, with a LOD score of 2.4. The combined-haplotype data identify a critical region between D19S570 and D19S908, an interval of 8.5 cM on 19q13.1-19q13.3. This is the first study to localize a gene for nonsyndromic SD. ARSD is clinically heterogeneous and is likely to result from mutations in developmental genes or from regulating transcription factors. Identification of these genes will improve the understanding of the molecular processes contributing to both normal and abnormal human vertebral development.

The authors report an interesting case of a minimally symptomatic 23-year-old African American woman who was found to have extensive diffuse reticulonodular opacities of the lungs on a routine chest radiograph. She had a hysterectomy 5 years previously for multiple leiomyomas of the uterus. She had no history of any prior exposure to dusts or toxins. Collagen vasculitides and bacterial, mycobacterial, and fungal infectious causes were excluded through standard testing, and a bronchoscopic lung biopsy was nonspecific. An open lung biopsy revealed multiple nodules of proliferating smooth muscle cells intermixed with irregular areas of epithelial-lined spaces. Histologically, the muscle cells appear benign with a very low mitotic rate, and the pathologic findings were consistent with benign metastasizing leiomyomatosis (BML). Staining for estrogen and progesterone receptors, actin, and c-kit were performed. This case and the review of the medical literature support the concept that BML originates from an antecedent leiomyoma of the uterus in virtually all cases with rare exceptions. It appears that tumor metastasizes to lungs or other extrauterine tissues via hematogenous spread. However, the origin of the tumor remains controversial. BML is a rare entity, with only a handful of reports in the medical literature. The authors report an interesting case of BML in a 23-year-old patient who, to their knowledge, is the youngest such patient described and who, at 13 years, has the longest period of clinical follow-up. In this article, the authors review the pathogenesis, cytogenetics, histologic markers, and management options of this rare entity.