ABSTRACT
It is widely accepted that the Epstein-Barr virus is etiologically associated with the development of nasopharyngeal carcinoma. The human papillomavirus is also associated with inverted papilloma. We used the polymerase chain reaction technique to detect both viruses in both types of tumors. Flow cytometry was also used to study the DNA pattern and proliferative behavior of the tumors in relation to the viruses. EBV was detected in 13/20 (65%) of NPC specimens, and in none of IP (n = 10) or control specimens (n = 10). This indicates the contribution of EBV as an etiologic factor in NPC. Five cases of NPC (25%) were positive for HPV 16, two of them were EBV positive. Four HPV 16 positive cases were found among cases with inverted papilloma, but none among the control cases. Flow cytometry revealed that all NPC, IP, and control samples were diploid except one aneuploid NPC sample. Proliferative capacity (PC) of primary tumors was predictive of tumor recurrence in NPC. Using 13.6% as a cut-off point for PC, we were able to discriminate between high risk and low risk groups with 100% sensitivity and 86% specificity. PC can be used as a baseline prognostic parameter in NPC, making it possible to modify courses of treatment in an attempt to inhibit tumor recurrence.
Subject(s)
Cell Cycle , Flow Cytometry , Herpesvirus 4, Human/isolation & purification , Nasopharyngeal Neoplasms/virology , Papilloma, Inverted/virology , Papillomaviridae/isolation & purification , Adolescent , Adult , Aged , Aneuploidy , Child , DNA, Neoplasm/analysis , DNA, Viral/analysis , Diploidy , Egypt , Female , Herpesvirus 4, Human/genetics , Humans , Kinetics , Male , Middle Aged , Nasopharyngeal Neoplasms/pathology , Papilloma, Inverted/pathology , Papillomaviridae/genetics , Polymerase Chain ReactionABSTRACT
Aminooxyacetic acid (AOAA) is a transaminase inhibitor that has been shown to protect the inner ear from loud noises. This study was done to determine if it can also protect against the cochleotoxic action of gentamicin. Four groups of guinea pigs were injected with gentamicin in doses approximating a clinical therapeutic dose and then in ototoxic doses. Thereafter animals were treated with parenteral AOAA. The effect on hearing was investigated using Preyer's reflex measurements. All animals were sacrificed and their cochleas were examined histologically using the surface preparation technique and mid-modiolar semithin sections. Histocochleograms were plotted to compare the effects of treatment in the animal groups. There was no difference seen among the groups tested. Cochlear damage was nearly equal in all animals, and AOAA was not found to protect the cochlea against gentamicin-induced ototoxicity of gentamicin. The mechanism of the ototoxicity produced is discussed on the basis of the findings. Additionally, hair cell degeneration was studied after therapeutic doses of gentamicin. Changes seen were found to be equal to or less than 5% of the hair cells and were scattered throughout the entire cochlea.
