Synthetic antigens representing the antigenic variation of human hepatitis C virus.

Immune responses against hepatitis C virus (HCV) have been studied by numerous groups. However, details concerning the production of antibodies to antigenically variable epitopes remain to be elucidated. Since the sequences of the variable regions of several HCV proteins are different among the virus strains infecting patients, we decided to design peptide combinations that represent the theoretical maximum antigenic variation of each epitope to be used as capture antigens. We prepared six peptide mixtures (hypervariable epitope constructs; HECs) representing six different epitopes from structural and non-structural proteins of HCV from genotypes 1-6. Plasma from 300 HCV patients was tested to determine if their antibodies recognize the synthetic constructs. All the patients were chronically infected with diverse HCV genotypes and did not receive antiviral treatment. Antibodies to one or more of the HECs were detected in all of the HCV-infected individuals. Immunogenicity of the HCV HECs was also evaluated in outbred and inbred mice. Strong HEC-specific antibodies were produced, and cellular responses were also induced that were Th-1 rather than Th-2. Our results show that HCV HECs are both antigens that can be used to detect the broad cross-reactivity of antibodies from HCV-infected patients, and strong immunogens that can induce antigen-specific humoral and cellular immune responses in mice.

Correlation between MRI and operative findings in Bell's palsy and Ramsay Hunt syndrome.

PURPOSE: To investigate the correlation between gadolinium enhanced magnetic resonance image (MRI) results and surgical findings of facial nerves in Bell's palsy and Ramsay Hunt syndrome. MATERIALS AND METHODS: From 1995 to 2004, MRI was performed on 13 patients with Bell's palsy or Ramsay Hunt syndrome, who were offered with surgical decompression of the facial nerve through the middle cranial fossa approach. Gadolinium enhanced MRI was performed on all patients and the enhancement of the facial nerve was evaluated by radiology specialists. Operative findings including the degree of the facial nerve segment swelling were examined. Furthermore, the time interval from the onset of palsy to surgery was evaluated. RESULTS: Swelling of facial nerve segments was found in patients with enhanced facial nerves from MRI. The swelling of the facial nerve in the labyrinthine segment in particular was identified in all patients with enhanced labyrinthine segments in MRI. The intraoperative swelling of geniculate ganglion of facial nerve was found in 78% of patients with enhanced facial segment in MRI (p=0.01). The intraoperative swelling of tympanic segment was observed from fourth to ninth weeks after the onset of palsy. CONCLUSION: MRI enhancement of facial nerves in Bell's palsy and Ramsay Hunt syndrome is associated with the extent of intratemporal lesions of facial nerves, especially in the labyrinthine segment.

New method of identifying the internal auditory canal as seen from the middle cranial fossa approach.

OBJECTIVES: The middle cranial fossa approach allows one to remove acoustic tumors and preserve the facial nerve and hearing. However, there are no consistent landmarks on the surface of the temporal bone to identify the internal auditory canal. This study was designed to identify the internal auditory canal by use of external and internal references as seen during the middle cranial fossa approach. METHODS: We dissected 32 temporal bones using the middle cranial fossa approach and measured the distances from the posterior origin of the zygomatic arch to an imaginary coronal line between the foramen spinosum and the foramen ovale. We measured the angle between the lines drawn from the posterior origin of the zygomatic root to the foramen spinosum and from the foramen spinosum to the porus of the internal auditory canal. RESULTS: The distances were 14.7 mm and 22.9 mm, respectively, and the angle was roughly 90 degrees. CONCLUSIONS: In this study, we found external and internal landmarks that help to locate the internal auditory canal.