The pyrogen test or the endotoxin test has been playing a crucial role in detecting endotoxin in parenteral drugs. The current test methods, however, have disadvantages such as requiring a relatively high number of animals or an inadequacy in direct evaluation of in vivo activity. We made an attempt to establish a new in vitro assay method that can overcome the shortcomings of the current assay methods. We standardized the system of tumor necrosis factor-alpha (TNF-α) induction from the peripheral blood of rabbits for assaying endotoxin activity. This in vitro assay showed a linear dose-response regression between 0.1 and 5.0 endotoxin units per milliliter of endotoxin and a definite homogeneity of variance by logarithmically transforming the endotoxin and TNF-α concentrations in the reaction mixtures at 5 h of incubation at 37°C. The assay showed a definite correlation with the pyrogen test but not with the endotoxin test when endotoxins from various bacteria were tested.

Today, rheumatic fever is the most common cause of heart disease in children and young adults, and it accounts for about half of all cardiovascular diseases causing death in the first four decades of life, in India. In the present study, conducted during 1991-1992 at Chennai, India, a total of 666 school girls aged 5-15 years were examined clinically for one or more of the following signs and symptoms: repeated sore throat, joint pain/swelling, epistaxis, chest pain, breathlessness, palpitation, abdominal pain, etc. Out of the 666 children screened, 124 were recruited for the present study, based on their meeting one or more of the above mentioned clinical criteria. They were screened for the presence of group A β-hemolytic streptococci, and for antistreptolysin O and C-reactive protein. Thus, the aim of the present study was to reduce the load of streptococcal infection and the consequent risk of developing rheumatic fever and rheumatic heart disease. In the present study group, 89.5% of the children indicated a history of repeated sore throat. However, only 4.0% of the children in the study group were positive for group A β-hemolytic streptococci. The antistreptolysin O and C-reactive protein levels were higher in 11- to 15-year-old patients than in 5- to 10-year-old patients in the study group.

A marked increase in sporadic cases of enteritis due to enterohemorrhagic Escherichia coli serogroup O157 occurred in Osaka City, Japan, during 1996. To elucidate why the number of cases had increased, the isolates were classified using phage typing, random amplified polymorphic DNA analysis, and pulsed-field gel electrophoresis (PFGE). Fifty-seven percent of the isolates (105/184) belonged to the same phage type (PT-32) and gave the same PFGE pattern; the clone had been isolated during a 3-week period, with a peak on July 15. It was concluded that the majority of the cases identified in July 1996 formed an outbreak, although epidemiological links to a possible common source were not established. The possibility that this outbreak was part of a huge regional outbreak including children at primary schools in Sakai City was discussed.

Previously, we demonstrated a depression of cell-mediated immunity in mice by street rabies virus infection. In the present study, we investigated several events during the course of infection and looked for alterations in the host lymphoid cells for evidence of apoptosis. Total cellular RNA was extracted from muscle tissues at the inoculation site of peripherally infected mice at different intervals after infection. Rabies virus mRNA was monitored by reverse transcription-PCR. The length of virus localization at the site of exposure in the muscle was as long as 5 days post-inoculation before the virus entered the central nervous system. At this inoculation site, the virus disappeared transiently between days 7 and 9 after infection but then was restored thereafter until death. Annexin V-fluorescein isothiocyanate staining of splenocytes and thymocytes from mice revealed apoptotic changes in these cells with a marked increase after day 6 of infection. Rabies virus antigen in the brain became detectable 6 days after infection; this occurred parallel to the appearance of apoptosis in the lymphoid cells. There was atrophy of the spleen and thymus, with no evidence of infection. Our results suggest that the interaction between the rabies virus and infected neurons triggers the process of lymphoid cell apoptosis, which reflects the defective operation of the immune system.

We summarized the consultation cases of parasitic diseases and entomological cases presented at the Department of Medical Zoology, Jichi Medical School. Among 173 consultations from January 1996 to December 2000, 64 cases were parasitologically or entomologically positive. We primarily diagnosed the cases morphologically and intermittently used sero-diagnosis methods. Ascariasis and diphyllobothriasis due to foods comprised the major consultation cases. Cases of malaria, second in frequency, were all imported from tropical countries. Some rare but important cases, including entomological cases, are discussed.