CXC-chemokine receptor (CXCR₄) is one principle coreceptor for the entry of T cell line (T)-tropic HIV-1 virus into a cell. In order to find more efficacious therapeutic possibilities for people with an HIV-1 infection, we explored the inhibitory effects of antisense RNA on CXCR₄ expression in MT4 cells. First, we used RT-PCR to obtain DNA fragments from healthy adult peripheral blood mononuclear cells; these fragments targeted the initiation region of CXCR₄ mRNA translation. We then constructed a recombinant retroviral vector, pLXSN-X4a (containing antisense RNA to CXCR₄). After packaging by PA317 cells, the pseudovirion of the recombinant vector had formed and succeeded in transfecting MT4 cells (a kind of T-tropic HIV-1 susceptibility cell line). The PCR and RT-PCR results showed that the recombinant vector had integrated into the genome of MT4 cells and had been transcribed. The expression of CXCR₄ on the surface of MT4 cells transfected with antisense RNA was reduced by 30%, compared with those cells transfected with blank vector or untransfected cells. No change in the DNA synthesis rates or in cell proliferation was found in any of the transfected cells. After a challenge with HIV-1 SF33, the cells transfected with antisense RNA vector (pLXSN-X4a) produced reduced p24 levels compared with the cells transfected with blank vector (pLXSN) or untransfected cells. These results indicated that these CXCR₄-antisense expressing cells could resist T-tropic HIV-1 infection and could retain normal biological functions. These studies provide useful data for further experiments in this area.

In order to determine a practically useful quantitative assay method for tetanus antibody in a large-scale seroepidemiological study, a method combining an in-house ELISA with a particle agglutination test (KPA) was evaluated in comparison with the in vivo mouse neutralization test. Serum samples with mouse neutralization antibody titers 0.01 IU/ml (the minimum protective level) or below showed considerable overestimation of antitoxin titers up to 1.0 IU/ml when studied by in-house ELISA alone. On the other hand, the KPA values were highly correlated with the mouse test, even in cases of titers equal to 0.01 IU/ml or below. The combination of these two procedures, in which in-house ELISA values of 1.0 IU/ml or below were replaced by KPA values, provided a high correlation in antibody titers with the mouse test (r = 0.968). We applied this combined method to a tetanus seroepidemiological survey in a province in Turkey. The survey included 347 subjects from the healthy population, and the quantitative analyses showed high antibody levels in children and young adults and significantly low levels among adults aged 40 or over. A characteristic distribution of antibody titers in each age group was also demonstrated.

The purpose of the present study was to develop an optimal method for culturing Simkania negevensis. Centrifugation was effective for the propagation of S. negevensis, but sonication was not effective. The addition of cycloheximide to the culture medium significantly decreased the number of inclusions. Pretreatment of host monolayers with diethylaminoethyl-dextran or polyethylene glycol was detrimental. The most optimal conditions were centrifugation of the inocula onto untreated Vero cells, and culture in RPMI 1640 medium containing 10% fetal calf serum without cycloheximide or antimicrobial agents.

Ticks were collected from ruminants in various areas of Sudan in 1998 and 2000. Primer pairs of rickettsial citrate synthase gene (gltA) and a spotted fever group (SFG) rickettsial 190-kDa surface antigen gene (rompA), respectively, were used for identification. Polymerase chain reaction (PCR)-positive products were used for DNA sequencing. The gltA gene was detected in 55% of the ticks examined (57/104). Among the 57 ticks studied, 19 were positive for the rompA gene. Thus, 18% of the ticks examined were found to be infected with SFG rickettsiae. The nucleotide sequences of the amplified rompA gene fragment of Hyalomma spp. and Amblyomma spp. were similar to those of Rickettsia aeschlimannii and Rickettsia africae, respectively. In this study, we succeeded in detecting the SFG rickettsiae gene in ticks, and established that there were at least two species of SFG rickettsiae in field ticks in Sudan.

Feral raccoons captured in Hokkaido, Japan were examined for the presence of rabies virus neutralizing antibody (VNA). Between 2000 to 2002, 741 serum samples were collected and then subjected to VNA titer determination by rapid fluorescent focus inhibition test (RFFIT). Sera showing RFFIT titers of ≧1:25 have been considered as positive according to previous reports. VNA was detected in none of serum samples from the feral raccoons. The present study provides valuable background information for rabies prevention in Japan. The potential risk of raccoon-derived rabies in the wilderness has been of concern because of the increasing number of feral raccoons originally introduced from rabies-endemic countries. The continuous monitoring of sick and/or dead wild raccoons would help to prevent an epidemic spread of raccoon rabies.

In this study, 34 clinical cerebrospinal fluid isolates of Cryptococcus neoformans were serotyped, and their in vitro susceptibilities to amphotericin B, fluconazole, and voriconazole were analyzed. Of these 34 isolates, serotype A was found in 29 isolates and serotype B in the other five. The voriconazole geometric mean MIC was significantly lower than the amphotericin B/antibiotic medium 3 geometric mean MIC (P < 0.0001 at both 48 and 72 h), as well as the fluconazole geometric mean MIC (P < 0.0001 at both 48 and 72 h). Of the three antifungal agents, only fluconazole, with geometric mean MICs at both 48 and 72 h, showed significant difference between the serotypes A and B of C. neoformans.

During the 5 years of the study period (October 1999 - October 2003), 110 strains of Shigella were isolated from fecal samples of patients having acute diarrheal diseases. Shigella sonnei phase 1 was the most prevalent (88/110, 80.0%) serotype. Resistance to nalidixic acid was not encountered from 1999 - 2002. Nalidixic acid resistance was observed in 6/13 (46.1%) of the S. sonnei phase 1 strains isolated from April - August 2003. Minimum inhibitory concentration to nalidixic acid among these strains was 48 - 96 μg/ml. All the six nalidixic acid resistant strains of S. sonnei phase 1 had reduced susceptibility (MIC 0.25 μg/ml) to ciprofloxacin.

The role of Pseudomonas aeruginosa exotoxin A was studied in acute and chronic pyelonephritis models employing an exotoxin A-producing strain PAO, and its toxin deficient mutant PAOT1. Interestingly, the mutant strain was found to be at an advantage in its ability to induce acute pyelonephritis and it induced severer renal pathology. No significant differences were observed in the ability of the parent strain and its mutant to induce chronic renal inflammation.

Following the re-emergence of polio in West Africa, an investigation was conducted on the occasion when transients gather for the festival in Niger, where the oral polio vaccine (OPV) and BCG coverage among children under the age of 5 years can be evaluated. A total of 259 children were investigated, including 186 from settled families and 73 from unsettled families. OPV coverage was found to be as low as 32.4%, and 61.8% of all participants in the study had not received both OPV and BCG. There were more children who had not received the OPV in unsettled families than in settled families. As there are still unvaccinated children in Niger, polio continues to occur among them. Moreover, outbreaks can transfer to more densely-populated areas, causing much larger outbreaks. To stop the chain of transmission, it is essential to reconsider the strategy of mass vaccination in order to cover all children thoroughly, including transients.

Tuberculous lymphadenitis without pulmonary manifestation is an uncommon entity in developed countries, and the possibility of tuberculous infection is usually ignored in the differential diagnosis of lymphadenopathy. Therefore, appropriate treatment may be delayed. Paralysis of the recurrent laryngeal nerve caused by mediastinal lymphadenopathy due to tuberculosis is an extremely rare condition. In this paper, we present a patient who had vocal cord paralysis caused by tuberculous lymphadenopathy of the superior mediastinum. After anti-tuberculosis treatment, vocal cord function was only partially recovered, while the clinical, radiological, and laboratory abnormalities were completely recovered.