Cervical intramedullary melanocytoma: A case report and review of literature

Meningeal melanocytomas are rare tumours of the central nervous system, most commonly found in the intracranial compartment (posterior cranial fossa). Spinal lesions are uncommon, with the majority being intradural, extramedullary lesions. Intramedullary melanocytomas are extremely rare and are most commonly found in the thoracic region. We report a patient with cervical intramedullary melanocytoma and review the available literature regarding this rare pathology.     

Amplification and sequence analysis of the precore and core region of the HBV genome from sera of Spanish patients with HBV2-like infections

Hepatitis B virus (HBV) infections are occasionally associated with unusual serological profiles which may be attributed to the lack of immune responsiveness of the patients or to variants of the virus. The term HBV₂ was introduced to describe potential variants of HBV which do not elicit a detectable immune response to the nucleocapsid (anti-HBc) in apparently irnrnune-cornpetent patients. The entire nucleotide sequences of the nucleocapsid genes of viruses from two Spanish patients with HBV₂-like infections are reported here. In-frame deletions and other mutations in these sequences may account, at least in part, for the unusual serological profiles of the patients. Antibody responses to viral proteins containing deletions may not be detected by commercially available assays. © 1995 Wiley-Liss, Inc.     

Research advance directives: protection or obstacle?

OBJECTIVE: This study assessed how many adults completed a research advance directive and the preferences indicated on the completed forms. METHOD: The authors analyzed all 2,371 adults admitted as inpatients to the NIH Clinical Center from March 14 to Sept. 13, 2000. RESULTS: Overall, 11% of adult inpatients completed a research advance directive. Of those who specified preferences, 13% were not willing to participate in future research should they become unable to consent, 76% were willing to participate in research that might help them, 49% were willing to participate in research that would not help them and posed minimal risk, and 9% were willing to participate in research that would not help them and posed greater than minimal risk. CONCLUSIONS: Proposals to allow cognitively impaired adults to participate in research only with a formal advance directive could block important research. More flexible approaches should be considered to protect these individuals.     

Precore and core mutations in HBV from individuals in india with chronic infection

Ten hepatitis B surface antigen seropositive carriers (5 asymptomatic and 5 with chronic liver disease) were tested for HBeAg/anti-HBe and for HBV-DNA using the polymerase chain reaction. Five were DNA-positive, 2 with HBeAg and 3 with anti-HBe. Nucleotide sequences were determined for these 5 cases. Hepatitis B virus DNA from one cirrhotic carrier with anti-HBe had a mutation in the precore region (nucleotide position 1862) which may affect signal peptide cleavage and HBeAg synthesis. In the other 2 anti-HBe- and DNA-positive cases, a cirrhotic carrier and an asymptomatic case, there was a mutation at nucleotide position 1896 leading to a termination codon in the precore region. In all 5 patients, except for one or two missense mutations, there was no significant variation in the core region. © 1995 Wiley-Liss, Inc.     

Biome representational in silico karyotyping

Metagenomic characterization of complex biomes remains challenging. Here we describe a modification of digital karyotyping-biome representational in silico karyotyping (BRISK)-as a general technique for analyzing a defined representation of all DNA present in a sample. BRISK utilizes a Type IIB DNA restriction enzyme to create a defined representation of 27-mer DNAs in a sample. Massively parallel sequencing of this representation allows for construction of high-resolution karyotypes and identification of multiple species within a biome. Application to normal human tissue demonstrated linear recovery of tags by chromosome. We apply this technique to the biome of the oral mucosa and find that greater than 25% of recovered DNA is nonhuman. DNA from 41 microbial species could be identified from oral mucosa of two subjects. Of recovered nonhuman sequences, fewer than 30% are currently annotated. We characterized seven prevalent unknown sequences by chromosome walking and find these represent novel microbial sequences including two likely derived from novel phage genomes. Application of BRISK to archival tissue from a nasopharyngeal carcinoma resulted in identification of Epstein-Barr virus infection. These results suggest that BRISK is a powerful technique for the analysis of complex microbiomes and potentially for pathogen discovery.     

Association of reflux with otitis media in children.

OBJECTIVES: To confirm the finding of pepsin/pepsinogen in middle ear fluid of children with chronic or recurrent otitis media (OME or ROM), and to ask parents about symptoms associated with gastroesophageal reflux (GER). METHODS: Middle ear fluid was collected from children undergoing tympanostomy tube placement. We tested this fluid for pepsin/pepsinogen using a proteolytic enzyme assay and an ELISA. Parents completed questionnaires about symptoms of GER in their children. RESULTS: We collected 36 samples from 22 children; 16 of 22 children (73%) were positive with the proteolytic assay; 17 (77%) were positive with ELISA. Questionnaires did not show increased GER symptoms. CONCLUSIONS: We replicated the finding of pepsin/pepsinogen in middle ear fluid of children with OME or ROM, but did not find any increase in GER symptoms. Further research is needed to establish a causative link between GER and OM.