Numb chin syndrome associated with vertical root fracture and odontogenic infection.

Numb chin syndrome (NCS) is a multifactorial neuropathic disorder associated with paresthesia to the chin, lip, and oral mucosa, particularly arising as a sequela to various dental-related procedures or infections in the mandible. Timely elucidation of the underlying etiology is of paramount importance as the presentation of NCS could serve as a harbinger of malignancy or metastatic disease. This report describes an unusual case of NCS developing synchronously with a vertical root fracture and odontogenic infection in a mandibular first molar. Clinicians should consider the inclusion of a vertical root fracture as plausible cofactor for the development of NCS.

Analysis of sequence and haemagglutinin activity of the HN glycoprotein of Newcastle disease virus.

Reverse transcription-polymerase chain reaction (RT-PCR) was used to generate sequence data for recent Taiwanese strains of Newcastle disease virus (NDV) isolated from 1999 to 2003, covering the full length of the haemagglutinin-neuraminidase (HN) gene and protein. Nucleotide sequence analysis of the HN gene of these recent isolates revealed that the whole HN gene carries an open reading frame encoding 571 amino acids and possesses a shorter C-terminal extension. Six amino acid substitutions in epitopes on the HN glycoprotein of the recent Taiwanese NDV isolates were also found. All the recent Taiwanese NDV isolates have the amino acid sequence (112)RRQKRF(117) for the F protein. A phylogenetic tree analysis based on the nucleotide sequences of the F gene revealed that all recent Taiwanese isolates were related to genotype VII viruses. Since the recent Taiwanese NDV isolates exhibited a low level of haemagglutination (HA) activity, we generated two sets of mutants to elucidate whether mutations in the heptad repeat region of the HN protein could affect the HA activity. To demonstrate the presence of the viruses used in the HA test, a real-time RT-PCR was established to determine the copy number of NDV isolates. From sequence analysis, site-directed mutagenesis, and haemadsorption assays, it was found that the HN glycoprotein of recent Taiwanese NDV isolates carrying a substitution at the amino acid residue 81 (I to M) in the heptad repeat region in the stalk domain showed a dramatic decrease in the activity of HA. We infer from these results that a specific amino acid sequence within the heptad repeat region of the stalk is important for the HA activity of the HN glycoprotein.

Successful intravenous thrombolysis in ischemic stroke caused by infective endocarditis.

INTRODUCTION: Infective endocarditis can lead to serious neurological complications including ischemic stroke and intracranial hemorrhage. Treatment with intravenous thrombolysis within 3 h of symptom onset has become the standard of care in acute ischemic stroke, but the safety and efficacy of this intervention in patients with infective endocarditis is unknown. SUMMARY OF CASE: We report the case of a patient with ischemic stroke who experienced substantial neurological improvement after being treated with intravenous thrombolysis (NIH stroke scale score of 15 on admission and 4 after treatment) and was subsequently found to have acute infective mitral endocarditis. CONCLUSION: Favorable response to thrombolysis may occur in patients with stroke due to infectious endocarditis. The safety of this therapy remains to be established.

Avian reovirus-induced apoptosis related to tissue injury.

Apoptosis plays an important role in pathogenesis of many viral infections. Infection of chicken with avian reovirus S1133 causes tissue injury related to virus-induced apoptosis. To determine whether avian reovirus (ARV) induced apoptosis in chicken tissues, six 3-week-old specific pathogen free White Leghorn chicks were inoculated with ARV S1133. Tissues were dual-labelled for the simultaneous detection of viral antigen containing and apoptotic cells. DNA laddering was detected in ARV-infected but not mock-infected chicken tissues. Dual-labelling assay revealed that the majority of antigen-expressing cells were not apoptotic. Surprisingly, some apoptotic but non-antigen-expressing cells were frequently located in the vicinity of antigen-expressing cells. Syncytium formation in ARV-infected chicken tissues undergoing apoptosis was apparent, suggesting a correlation between virus replication and apoptosis in chicken tissues.