Prevalence of antibody to hepatitis E virus among wild sika deer, Cervus nippon, in Japan

We examined 976 sika deer serum samples, 159 liver tissue samples and 88 stool samples collected from 16 prefectures in Japan, and performed ELISA and RT-PCR assays to detect antibodies to HEV and HEV RNA, respectively. Although 25 (2.6%) of 976 samples were positive for anti-HEV IgG, the antibody titers were very low. The OD values ranged between 0.018 and 0.486, forming a single distribution rather than a bimodal distribution, suggesting that the antibody detected in this study was not induced by HEV infection, or that deer have low sensitivity to HEV. HEV RNA was not detected in these samples, also suggesting that deer may not play a role as an HEV reservoir.

Development of a rapid strain differentiation method for methicillin-resistant Staphylococcus aureus isolated in Japan by detecting phage-derived open-reading frames

AIMS

To develop a rapid genotyping method for investigating outbreaks of methicillin-resistant strains of Staphylococcus aureus (MRSA) isolated in Japan.

METHODS AND RESULTS

Isolates were genotyped by detecting the keeping pattern of 16 open-reading frames (ORFs), a process we call phage ORF typing (POT). Thirteen of the ORFs were selected from phage genomes and one from a genomic island SaGIm in the genome of strain Mu50. The other two ORFs, one from Tn554 and one from staphylococcal cassette chromosome mec (SCCmec) type II, were used as strain markers. Three hundred and sixty-eight isolates from five hospitals were classified into 133 types by POT, whereas they were classified into 139 types by pulsed-field gel electrophoresis (PFGE) subtyping. The discriminatory power of POT (D=0.989) was equal to that of PFGE subtyping (D=0.986).

CONCLUSIONS

MRSA isolates collected in Japan can be genotyped by detecting the keeping pattern of phage-derived ORFs with a discriminatory power equal to that of PFGE subtyping.

SIGNIFICANCE AND IMPACT OF THE STUDY

MRSA isolates can be genotyped rapidly by detecting phage-derived ORFs. As particular pandemic clones can be found in a specific region, a typing method localized to a pandemic clone may be effective for the rapid genotyping of MRSA during outbreaks.

Amino-acid change on the antigenic region B1 of H3 haemagglutinin may be a trigger for the emergence of drift strain of influenza A virus

Sera from 27 children and eight older persons, which had been collected in 1998 and 1999 and showed haemagglutination-inhibition (HI) activity against influenza A/Sydney/5/97 (H3N2) strain, were characterized with a binding assay using chimeric haemagglutinin (HA) proteins between A/Aichi/2/68 (A/AI/68) and A/Sydney/5/97 (A/SD/97) strains. Sera from the young children had a tendency to recognize only the antigenic site B1 of the HA1 region. On the other hand, sera of the older individuals were fully reactive to all antigenic sites of HA1 except antigenic site D. Recent epidemic strains, A/Panama/2007/99 (A/PM/99)-like viruses have differences in amino acids in antigenic sites A, C, and B2 but not B1. However, human antisera obtained even from young children had HI activity to Panama-like viruses. The limited epidemic of A/PM/99-like viruses may have been due to the existence of antibody against B1, which had been produced in response to infection by the A/SD/97-like viruses.

Epidemiological investigation of a fatal case of cholera in Japan by phenotypic techniques and pulsed-field gel electrophoresis

A fatal case of cholera caused by Vibrio cholerae 01 El Tor serotype Ogawa occurred in Aichi Prefecture, Japan in 1995. The patient was identified locally, but the route of the infection was unknown. The causative isolate and 38 other domestic and imported V. cholerae O1 isolates, obtained between 1984 and 1997, were analysed by prophage typing, antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE). This was done to determine whether the isolate from this case differed from others associated with either mild cholera infections or asymptomatic carriage, and to elucidate the route of infection. Cholera toxin (CT) from 37 toxigenic isolates was assayed semi-quantitatively. The 39 isolates were divided into 12 temporary types in accordance with the results of the three typing techniques. The isolate from the fatal infection and nine other isolates were classified as temporary type IV. No difference in CT production was found between the isolate from the fatal case and the other 36 toxigenic isolates. Taken together, it is unlikely that a V. cholerae 01 isolate of distinguishable type was responsible for the fatal illness. Temporary type IV isolates were frequently present in both domestic and imported cases from 1994 to 1997 in Aichi, but they did not emerge before 1993. These results suggest that a new clone was introduced after 1993 from overseas and then disseminated into Aichi, and this may have been an important step in triggering the fatal case of cholera.

Identification of Aichi virus infection by measurement of immunoglobulin responses in an enzyme-linked immunosorbent assay

Using inhibitory enzyme-linked immunosorbent assay, seroconversions to Aichi virus were detected in 24 (42.9%) of 56 patients with gastroenteritis in six outbreaks. Virus-specific immunoglobulin M (IgM) was detected in convalescent-phase sera from 7 of 24 patients. Of the other 17 patients, 12 developed a significant increase in both IgA and IgG levels and 5 developed a significant increase in IgG alone.

Construction of an infectious cDNA clone of Aichi virus (a new member of the family Picornaviridae) and mutational analysis of a stem-loop structure at the 5' end of the genome

Aichi virus is the type species of a new genus, Kobuvirus, of the family Picornaviridae. In this study, we constructed a full-length cDNA clone of Aichi virus whose in vitro transcripts were infectious to Vero cells. During construction of the infectious cDNA clone, a novel sequence of 32 nucleotides was identified at the 5' end of the genome. Computer-assisted prediction of the secondary structure of the 5' end of the genome, including the novel sequence, suggested the formation of a stable stem-loop structure consisting of 42 nucleotides. The function of this stem-loop in virus replication was investigated using various site-directed mutants derived from the infectious cDNA clone. Our data indicated that correct folding of the stem-loop at the 5' end of the positive strand, but not at the 3' end of the negative strand, is critical for viral RNA replication. The primary sequence in the lower part of the stem was also suggested to be crucial for RNA replication. In contrast, nucleotide changes in the loop segment did not so severely reduce the efficiency of virus replication. A double mutant, in which both nucleotide stretches of the middle part of the stem were replaced by their complementary nucleotides, had efficient RNA replication and translation abilities but was unable to produce viruses. These results indicate that the stem-loop at the 5' end of the Aichi virus genome is an element involved in both viral RNA replication and production of infectious virus particles.

Successful treatment with concurrent chemoradiotherapy followed by surgery for a patient with thymic adenocarcinoma

Most neoplasms arising from the thymic epithelium are considered to be 'thymomas', which are composed of cytologically benign, neoplastic epithelial cells and nonneoplastic lymphocytes. In contrast, thymic epithelial neoplasms displaying cytologically malignant features have recently been classified as thymic carcinomas of various types of histology. However, primary thymic adenocarcinoma is extremely rare and only four cases of it have been reported in the literature. We report a rare case of primary thymic adenocarcinoma of 4-year complete remission with concurrent chemoradiotherapy followed by surgery. A 61-year-old Japanese man was referred to us complaining of facial edema and general fatigue. Computed tomography scans revealed a huge mass in the anterior mediastinum obstructing the superior vena cava. He was diagnosed with thymic adenocarcinoma on needle biopsy. He was treated with induction chemoradiotherapy consisting of cisplatin, 5-FU and concurrent thoracic radiation, which yielded a partial response. He then underwent surgical resection of the remaining mass. However, pathologic examination of the resected mass revealed no malignant cells. The patient is doing well without symptoms or signs of relapse 53 months after diagnosis.

Expression of recombinant capsid proteins of chitta virus, a genogroup II Norwalk virus, and development of an ELISA to detect the viral antigen

The second open reading frame (ORF2) gene of the Chitta virus (CHV) was cloned to construct a recombinant baculovirus. The CHV ORF2 is predicted to encode a capsid protein of 535 amino acids (aa). CHV showed a high aa identity in the capsid region with genogroup II Norwalk virus (NV) (65-85%), but a low aa identity with genogroup I NV (44-46%). Phylogenetic analysis of the ORF2 gene demonstrated that CHV is genetically closely related to the Hawaii virus included in genogroup II NV. The recombinant capsid protein of CHV (rCHV) self-assembled to form empty virus-like particles (VLPs) when expressed in insect cells with the recombinant baculovirus. An enzyme-linked immunosorbent assay (ELISA) based on antisera to rCHV was developed to detect CHV antigen in stools. The antigen ELISA appeared to be highly specific to both rCHV and CHV-like strains. In addition, combined use of antigen ELISAs using antibodies against two antigenically distinct recombinant VLPs, the recombinant Chiba virus (rCV) and recombinant Seto virus (rSEV), enabled us to determine the genetic as well as antigenic relationship among these three viruses.

Serotype-specific antigen ELISA for detection of Chiba virus in stools

Chiba virus (CV), a Norwalk-like virus (NLV), was first identified as a cause of oyster-associated outbreak of gastroenteritis that occurred in Chiba prefecture, Japan, in 1987. An enzyme-linked immunosorbent assay (ELISA), based on hyperimmune antisera to recombinant baculovirus-expressed capsid proteins of CV (rCV), was developed to detect CV antigen in stools. No cross-reactions were observed with other enteric viruses including enteroviruses, rotaviruses, astroviruses, or enteric adenoviruses. The ELISA was used to screen 101 stools collected from 16 oyster-associated outbreaks of acute gastroenteritis. Twelve stools (11.9%) from seven outbreaks were positive for CV antigen. Ten rCV ELISA-positive strains were confirmed by RT-PCR and nucleotide sequencing. ELISA-positive strains showed 96-100% nucleotide sequence identity to each other, though they were obtained nine years apart. Phylogenetic analysis demonstrated that all ten strains clustered with the prototype CV in genogroup I viruses. We concluded that the antigen ELISA described in this study is highly type-specific, and that this method should be useful for epidemiological surveys of Chiba virus infections.

Molecular cloning, expression, and antigenicity of Seto virus belonging to genogroup I Norwalk-like viruses

The viral capsid protein of the Seto virus (SeV), a Japanese strain of genogroup I Norwalk-like viruses (NLVs), was expressed as virus-like particles using a baculovirus expression system. An antigen detection enzyme-linked immunosorbent assay based on hyperimmune antisera to recombinant SeV was highly specific to homologous SeV-like strains but not heterologous strains in stools, allowing us type-specific detection of NLVs.

Application of a reverse transcription-PCR for identification and differentiation of Aichi virus, a new member of the Picornavirus family associated with gastroenteritis in humans

Aichi viruses isolated in Vero cells from seven patients in five gastroenteritis outbreaks in Japan, five Japanese returning from Southeast Asian countries, and five local children in Pakistan with gastroenteritis were examined for differentiation based on their reactivities with a monoclonal antibody to a standard strain (A846/88) and a reverse transcription-PCR (RT-PCR) of three genomic regions. The RNA sequences were determined for 519 bases of these 17 isolates at the putative junction between the C terminus of 3C and the N terminus of 3D. The analyses revealed an approximately 90% homology between these isolates, which were then divided into two groups: group 1 (genotype A) included six isolates from four outbreaks and one isolate from a traveler and group 2 (genotype B) included one isolate from the other outbreak, four isolates from returning travelers, and all of the isolates from the Pakistani children. Based on the isolate sequences, a primer pair and a biotin-labeled probe were designed for amplification and detection of 223 bases at the 3C-3D junction of Aichi virus RNA in fecal specimens. The Aichi virus RNA was detected in 54 (55%) of 99 fecal specimens from the patients in 12 (32%) of 37 outbreaks of gastroenteritis in Japan. Of the 12 outbreaks, 11 were suspected to be due to genotype A. These results indicated that RT-PCR can be a useful tool to detect Aichi virus in stool samples and that a sequence analysis of PCR products can be employed to identify the prevalent strain in each incident.

An increase in multi-drug-resistant isolates of Salmonella typhimurium from healty carriers in Aichi, Japan

To investigate the prevalence of drug-resistant isolates of Salmonella Typhimurium in Aichi, Japan, we performed antimicrobial susceptibility tests for 148 isolates from healthy carriers, and from sporadic and outbreak cases of salmonellosis from 1980 to 1999. We found an increase in drug-resistant isolates from 56% (37/66) in the 1980s to 74% (61/82) in the 1990s due to increasing examples of four-, five-, and six-drug resistances. Of 98 resistant isolates in 1980-1999, 12 were identified as ampicillin (A)-, chloramphenicol (C)-, streptomycin (S)-, sulfonamide (Su)-, and tetracycline (T)-resistant S. Typhimurium (4 in the 1980s, 8 in the 1990s), whose pattern was identical to that of multi-drug-resistant S. Typhimurium definitive phage type 104 (DT104) which has been recently detected in various developed countries. Six-drug-resistance ACSSuTP (piperacillin), in which P was added to the core pattern of the ACSSuT, was also found in four isolates in the 1980s and seven in the 1990s. Another six-drug-resistant pattern, ACSSuTN (nalidixic acid), appeared in five isolates in the 1990s. These multi-drug-resistant isolates were predominately found in healthy carriers (21/28), suggesting that in Aichi the multi- (five- or six-) drug-resistant isolates of S. Typhimurium have existed in healthy carriers as well as in diarrhea patients in 1980 to 1999.

A phase II study of cisplatin and 5-fluorouracil with concurrent hyperfractionated thoracic radiation for locally advanced non-small-cell lung cancer: a preliminary report from the Okayama Lung Cancer Study Group

A recent meta-analysis and randomized studies have demonstrated that combined chemoradiotherapy is associated with a survival advantage for selected patients with locally advanced unresectable non-small-cell lung cancer (NSCLC). We conducted a phase II study of combined chemoradiotherapy to find a more effective combination of drugs and radiation than those previously reported for such patients. Between January 1994 and November 1996, 50 previously untreated patients with locally advanced unresectable NSCLC (stage IIIA with N2 or IIIB disease) were entered in this study. Patients were required to have Eastern Cooperative Oncology Group performance status < or = 2, age < or = 75 years and adequate organ function. Treatment consisted of three cycles of cisplatin (20 mg m(-2), days 1-5) and 5-fluorouracil (5-FU) (500 mg m(-2), days 1-5) every 4 weeks, and concurrent hyperfractionated thoracic radiation (1.25 Gy twice daily, with a 6-h interfraction interval; total radiation dose, 62.5-70 Gy). Of the 50 patients entered, 37 (74%) responded to this chemoradiotherapy, including two (4%) with complete response. By a median follow-up time of 41.0 months, 35 patients had died and 15 were still alive. The median time to progression for responding patients was 14.1 months (range, 2.6-51.3+ months). The median survival time was 18.7 months, with a survival rate of 66.0% at 1 year, 46.0% at 2 years and 27.6% at 3 years. Survival outcome was strongly affected by the extent of nodal involvement (median survival time, 27.4 months for N0-2 disease (n = 37) vs 10.7 months for N3 disease (n = 13); P = 0.007). The major toxicities of treatment were leukopenia and neutropenia (> or = Grade 3, 58% and 60% respectively). Other toxicities of > or = Grade 3 included thrombocytopenia (26%), anaemia (26%), nausea/vomiting (16%) and radiation oesophagitis (6%). Treatment-related death occurred for one patient. Our findings suggest that cisplatin and 5-FU in combination with concurrent hyperfractionated thoracic radiation is effective and feasible for the treatment of locally advanced unresectable NSCLC. The short-term survival in this study appeared to be more encouraging than those of similar chemoradiation trials. A randomized trial will be needed to compare the combination of cisplatin and 5-FU with other platinum-based regimens together with concurrent hyperfractionated thoracic radiation. In addition, in future studies, inclusion criteria for N3 disease with or without supraclavicular involvement should be reconsidered to correctly evaluate the effect of combined chemoradiotherapy for locally advanced unresectable NSCLC.

[Analysis of prevalent Orientia tsutsugamushi in Aichi Prefecture]

Orientia tsutsugamushi was isolated from one of 8 patients' sera in Aichi Prefecture, and was identified to have the same antigenicity with the KN-2 strain (KN-2 like) based on the reactivity with 13 types of strain-specific or cross-reactive monoclonal antibodies to Karp, Gilliam, and Kato strains. Four isolates from 4 unfed larvae and adult of Leptotrombidium pallidum were also classified as the KN-3 like strains. Using indirect immunofluorescence, sera from 20 patients with tsutsugamushi disease were tested for reactivity with KN-1, KN-2, KN-3, and GJ-1 strains, isolated from patients in Gifu Prefecture. Fifteen sera showed the highest titer against KN-2 strain in Immunogloburin M (IgM). Of the other 5, three were higher for KN-3 strain in IgM, and two were KN-1 or GJ-1, respectively. These results suggested that KN-2 like strains were prevalent in the region where the number of patients has been ranked the highest in Aichi Prefecture. KN-1, KN-3, and GJ-1 like strains were also existed in this area. KN-3 like strain was likely to be distributed in another area. Aichi Prefecture.

Phylogenic analysis of echovirus type 30 isolated from a large epidemic of aseptic meningitis in Japan during 1997-1998

During 1997 to 1998, a nationwide epidemic of aseptic meningitis occurred in Japan. More than 4,500 isolates from patients with aseptic meningitis were identified as echovirus type 30. To investigate the character of these isolates, we examined the nucleotide sequences of thirty-seven geographical representatives and compared them with 50 strains isolated during the past 20 years. The phylogenic analysis used partial sequences from either the VP1 or VP4-VP2 region of the viral capsid. This analysis revealed that the isolates were divided into six genomic groups. All isolates identified during 1997-1998 belonged to only two genomic groups; these two groups are thought to be the causative viral agents involved in the recent epidemic.

Molecular and serological characterization of adenovirus genome type 7h isolated in Japan

In 1996, three adenovirus type 7 (Ad7) strains were isolated from children with fever and upper respiratory diseases in Japan. Restriction endonucleases (REs) analysis and PCR amplification of the E3 7.7 kDa ORF revealed that these strains were genotype Ad7h and closely related to an Argentine Ad7h strain, which has been reported to be highly virulent and so far predominant only in South America. These strains showed weak cross-neutralizing activity and specific haemagglutination-inhibition activity to Ad3 antiserum. The present findings suggest that Ad7h in South America has spread to other parts of the world. Since the seroprevalence to Ad7 in the current Japanese population is very low due to the absence of Ad7 circulation in Japan for decades, Ad7 outbreak as a typical case of re-emerging infectious diseases is a cause for serious concern.

[A case of intrathoracic lipoma arising from the chest wall resected by video-assisted thoracoscopic surgery]

We present a case of lipoma arising from the chest wall spreading into the thoracic cavity. Although asymptomatic, a 65-year-old female was pointed out an abnormal shadow on the chest X-ray film taken at the mass survey. The tumor, measuring 3.4 x 3.0 x 2.0 cm in diameter, was surgically removed under thoracoscopic visualization through a small thoracotomy incision of lt. 1st intercostal space, and the diagnosis of lipoma was confirmed postoperatively by histopathologic examination.

Complete nucleotide sequence and genetic organization of Aichi virus, a distinct member of the Picornaviridae associated with acute gastroenteritis in humans

The complete nucleotide sequence of a novel enteric virus, Aichi virus, associated with nonbacterial acute gastroenteritis in humans was determined. The Aichi virus genome proved to be a single-stranded positive-sense RNA molecule with 8,251 bases excluding a poly(A) tail; it contains a large open reading frame with 7,302 nucleotides that encodes a potential polyprotein precursor of 2,433 amino acids. The genome contains a 5' nontranslated region (NTR) with 712 bases and a 3' NTR with 240 bases followed by a poly(A) tail. The structure of the genome, VPg-5' NTR-leader protein-structural proteins-nonstructural proteins-3' NTR-poly(A), was found to be typical of a picornavirus. The VP0-VP3 and VP3-VP1 cleavage sites were determined to be Q-H and Q-T, respectively, by N-terminal amino acid sequence analyses using purified virion proteins. Possible cleavage sites, Q-G, Q-A, and Q-S, which cleave P2 and P3 polyproteins were found to be similar to those of picornaviruses. A dendrogram based on 3Dpol proteins indicated that Aichi virus is genetically distinct from the known six genera of picornaviruses including entero-, rhino-, cardio-, aphtho-, and hepatovirus and echovirus 22. Considering this together with other properties of the virus (T. Yamashita, S. Kobayashi, K. Sakae, S. Nakata, S. Chiba, Y. Ishihara, and S. Isomura, J. Infect. Dis. 164:954-957, 1991), we propose that Aichi virus be regarded as a new genus of the family Picornaviridae.

A new-born baby outbreak of echovirus type 33 infection

OBJECTIVES

In 1994, an outbreak of echovirus type 33 (EV33) infection occurred in a maternity hospital in Japan. Nine new-born babies were infected, some presenting symptoms of encephalitis or disseminated intravascular coagulopathy. EV33 was isolated from the faeces or cerebrospinal fluid of all seven of the patients sampled, and serum antibody titres against EV33 were significantly elevated in the convalescence phase sera in all cases.

SUBJECTS AND METHODS

To study what public health situations EV33 may become a serious pathogen for new born babies, serum EV33 antibody positivity in the general population was examined. Sera were obtained 649 samples before the outbreak, and 344 samples after the outbreak from aged 7 days to 65 years old.

RESULTS

The average positive rate was 12.0% and the rate increased depending on age. Comparison of positive rates before and after this outbreak showed no increase in any age group. However, the positive rate was found to average only 5.6% in persons aged 16-30 years old, including pregnant women. This low positive rate in young adults would result in a lack or only a low level of antibodies in newborn babies.

CONCLUSIONS

In conclusion, our findings suggest that EV33 infection in the new-born baby with no or low level of maternal neutralizing antibody may cause serious symptoms.

Positron emission tomography-based boron neutron capture therapy using boronophenylalanine for high-grade gliomas: part I

Determination of tumor boron-10 (10B) levels is required for accurate neutron dosimetry during boron neutron capture therapy. We assessed a new method for quantitative measurement of boronated drug uptake in high-grade gliomas. This method uses positron emission tomography (PET) with fluorine-18-labeled L-fluoroborono-phenylalanine (L-18F-10B-FBPA), which was synthesized as an analogue of L-boronophenylalanine. We studied the accumulation of L-18F-10B-FBPA by PET in patients with high-grade gliomas. Dynamic PET studies of brain tumors revealed that L-18F-10B-FBPA accumulated gradually after bolus injection, and the value of PET activity divided by the integrated plasma activity reached a constant level 42 min after injection, which was defined as the incorporation constant (Ic*). This constant reflected the appropriate L-18F-10B-FBPA accumulation in tumor tissue. Based on the Ic* constant, the methods for estimating tumor 10B concentration were devised. With this method, the estimated values of 10B concentration in gliomas were very close to the 10B levels in surgical specimens. This method was based solely on PET and can potentially provide data that would assist in the selection of patients for future treatment with boron neutron capture therapy after surgical resection of their brain tumors.

Positron emission tomography-based boron neutron capture therapy using boronophenylalanine for high-grade gliomas: part II

Based on pharmacokinetic findings of fluorine-18-labeled L-fluoroboronophenylalanine by positron emission tomography (PET), methods for estimating tumor 10B concentration were devised. In clinical practice of boron neutron capture therapy (BNCT) for high-grade gliomas, a large amount of L-boronophenylalanine (L-10B-BPA)-fructose solution is used. Under these conditions, a slow i.v. infusion of L-10B-BPA-fructose solution should be performed for BNCT; therefore, the changes over time in 10B concentration in the target tissue were estimated by convoluting the actual time course of changes in plasma 10B concentration with a PET-based weight function including the proper rate constants [K1 (ml/g/min), k2 (min(-1)), k3 (min(-1)), and k4 (min(-1))]. With this method, the estimated values of 10B concentration in gliomas were very close to the 10B levels in surgical specimens. This demonstrated the similarity in pharmacokinetics between fluorine-18-labeled L-fluoroboronophenylalanine and L-10B-BPA. This method, using the appropriate rate constant, permits the determination of tumor 10B concentration and is widely suitable for clinical BNCT, because the averaged PET data are enough to use in future patients without individual PET study.

A randomized trial of hybrid administration of cyclophosphamide, doxorubicin, and vincristine (CAV)/cisplatin and etoposide (PVP) versus sequential administration of CAV-PVP for the treatment of patients with small cell lung carcinoma: results of long term follow-up

BACKGROUND

In an attempt to determine the efficacy of cyclophosphamide, doxorubicin, and vincristine (CAV)/cisplatin and etoposide (PVP) hybrid chemotherapy (HYB), a rapidly alternating chemotherapy, in patients with small cell lung carcinoma (SCLC), the authors conducted a randomized study to compare HYB with CAV-PVP sequential chemotherapy (SEQ).

METHODS

Patients in the HYB group received the 3-drug CAV combination on Day 1 and the 2-drug PVP combination on Day 8, repeated every 4 weeks for up to 6 cycles. Patients in the SEQ group received 3 cycles each of CAV and PVP sequentially every 4 weeks, delivered on Days 1 and 8. All responding patients with limited disease (LD) received thoracic irradiation (50 gray) after chemotherapy.

RESULTS

Between April 1988 and October 1992, 129 patients were evaluated fully. There were no significant differences in the treatment outcome between patients in the HYB and SEQ groups in terms of the complete response rate (59% for LD patients and 21% for extensive disease [ED] patients in the HYB group vs. 45% for LD patients and 16% for ED patients in the SEQ group), or median survival time (17.9 months for LD patients and 9.7 months for ED patients in the HYB group vs. 20.6 months for LD patients and 12.2 months for ED patients in the SEQ group).

CONCLUSIONS

Hybrid CAV-PVP therapy is effective for the treatment of SCLC, but appears to be no better than sequential therapy with the same regimen.

[Preliminary screening for antiviral AIDS drugs. VIII. Report for fiscal year 1995]

Preliminary screening of antiviral AIDS drugs has been carried out using three different in vitro assay systems. Among 96 samples of different origin tested, two were shown to inhibit the growth of HIV in vitro. One of the positive samples (plant origin) has hopeful signs, as the ranges of effective doses are wider than those of most of positive samples which had been found by us.

Combined brachytherapy and external beam radiotherapy in normal monkey brains--experimental radiation necrosis evaluated by sequential magnetic resonance imaging

Radiation-induced brain damage was evaluated using sequential magnetic resonance (MR) imaging in monkeys more than 1 year after either brachytherapy or combined brachytherapy and external beam radiotherapy (EBRT). MR images were obtained 1 week, 1 month, 3 months, and subsequently every 3 months after brachytherapy, and the volume of the lesions was measured. In all four monkeys receiving only brachytherapy and three of the four animals receiving combined brachytherapy and EBRT, MR imaging revealed only transient extensive edema 1 week after treatment and ring enhancement, which was maximal 3 months after treatment, surrounding the implantation site. In one of the four animals undergoing combined brachytherapy and EBRT, MR images obtained 9 months after treatment showed an irregularly extending enhanced lesion with edema. MR images obtained 15 months after brachytherapy in this monkey showed the lesion extended into the contralateral hemisphere through the corpus callosum. Necropsy revealed severe radiation necrosis. This animal developed a very similar MR imaging presentation to that often encountered in human brains after combined brachytherapy and EBRT.

Development of a gelatin particle agglutination reagent for measles antibody assay

A new agglutination test that utilizes gelatin particles as the carrier of measles antigen was developed and used to evaluate immune status to measles virus infection. The particle agglutination (PA) reagent reacted with monoclonal antibodies against two major proteins of measles virus, the hemagglutinin (H) and fusion (F) proteins. Children were followed individually for ten years for measles antibody. Results showed that the PA test was as sensitive and specific as the plaque neutralization test. The procedure is simple and rapid. No prior treatment of specimens is needed, and the test is completed in a single reaction. The PA test therefore can be used for diagnoses and epidemiologic surveys of measles virus infection.

Comparison of gelatin particle agglutination and hemagglutination inhibition tests for measles seroepidemiology studies

The prevalence of measles antibody in Japan was surveyed with a newly developed gelatin particle agglutination (PA) test, and the results compared with those of the hemagglutination inhibition (HI) test. The two age-distribution curves of the PA antibody-positive rates at > or = 1:8 and > or = 1:32 were almost the same in all the age groups, except the less-than-1-year-old group for which the rate at > or = 1:8 was higher than that at > or = 1:32 (p < 0.05, chi 2 test). In the vaccinated children, all groups older-than-1-year of age had antibody-positive levels of 96% or more. In contrast, in the unvaccinated children, there was a sharp increase in antibody-positive rates between the 1- and 4-year-old groups, indicative that about 80% of the children were infected by wild measles virus at these ages. A significant number of PA antibody-positive specimens were antibody-negative (< 1:8) by HI. The percentage of specimens in this category, PA (+) but HI (-), was greatest in infants less than one year old, and least in young children, but it increased with age to 97% of the HI (-) specimens from adults of more than 20 years of age. The PA test therefore detected some measles antibodies that HI could not. This test is simple and useful for making serosurveys in both developed and developing countries.

[Serotype determination of enteroviruses that cause hand-foot-mouth disease; identification of enterovirus 71 and coxsackievirus A16 from clinical specimens by using specific probe]

Coxsackievirus A16 (CA16) and enterovirus 71 (EV71) are known to be major causative agents of hand-foot-and-mouth disease prevalent in summer in Japan. Discrimination and identification of these viruses were often hampered by a nonneutralizable or nontypable virus. Therefore, a Southern blot hybridization that utilizes mixed probes specific to serotype was developed. Firstly, an approximately 650 bases spanning 5'-noncoding region to one third of VP2 including entire VP4 was amplified with a set of primers containing enterovirus common sequences and a genomic RNA as template. Secondary, the nucleotide sequences were determined using seven CA16 and eighteen EV71 strains including the standard strains, and the deduced amino acid sequences of VP4 were searched to find residues which are conserved in the same serotypes but diverged among different serotypes. Candidate positions for the mixed probes were defined at the carboxyl terminus of VP4. Thirdly, Southern blot analyses were carried out using thirty-nine enterovirus standard strains, seven CA16 isolates and sixty-six EV71 isolates previously identified by the neutralization test. The results revealed that each mixed probe exclusively bound to the homologous DNAs but not to the heterologous ones. In an attempt to determine serotypes without virus isolation, clinical specimens from hand-foot-and-mouth disease were examined. Of 78 throat swabs and 15 vesicular fluids, 71 (91.0%) and 13 (86.7%) specimens were clearly identified, indicating that the method described here offer advantages over the traditional neutralization assay: It is rapid, specific and less labor-consuming.

Epidemiology of poliomyelitis in Karachi, Pakistan: prospective studies during 1990-93

Between October 1989 and September 1993, 245 cases of poliomyelitis visited the Department of Pediatrics, Civil Hospital Karachi, Pakistan. The majority of them were between 6 months and 2 years of age and the epidemic occurred during the hot season. The dominant serotype was polio type 1. All of the polioviruses isolated from the patients were wild type. Virological studies also disclosed that enteroviruses other than polioviruses were prevalent among healthy children as well as diarrheal and polio patients. Serodiagnosis by poliovirus-specific immunoglobulin M antibody tests using the capture enzyme-linked immunosorbent assay method were in good agreement with the results of virus isolation. The present study demonstrated that Pakistan is a region endemic for wild poliovirus and more aggressive preventive measures are needed to eradicate poliomyelitis from the region.

Familial presumed cerebral cavernous angiomas diagnosed by MRI: three generations

Familial cerebral cavernous angiomas are rare, with an autosomal dominant pattern of inheritance. To our knowledge, 25 families with this disorder have been described. We report three family members in a direct line of descent, who all brain had lesions typical of cavernous angiomas on MRI.

Isolation of cytopathic small round virus (Aichi virus) from Pakistani children and Japanese travelers from Southeast Asia

Aichi virus was isolated in Vero cells from 5 (2.3%) of 222 Pakistani children with gastroenteritis but none was found in 91 healthy children. Aichi virus was also isolated from 5 (0.7%) of 722 Japanese travelers returned from tours to Southeast Asian countries and complained of gastrointestinal symptoms at the quarantine station of Nagoya International Airport in Japan. Of 5 Japanese travelers, 3 were returning from Indonesia, and 2 from Thailand or Malaysia. These results indicate that Aichi virus or a similar agent is endemic in Southeast Asian countries and is a cause of gastrointestinal symptoms in children in these areas or in Japanese travelers who visit there.

Disappearance of arachnoid cysts after head injury

The mechanism of the disappearance of arachnoid cysts is not fully understood. This article discusses the spontaneous disappearance of these cysts after head injury. Five patients underwent computed tomography and were diagnosed as having a subdural hematoma or effusion associated with arachnoid cysts. In four of the five patients, the cyst decreased in size or disappeared. These cases suggest a possible mechanism by which this type of cyst associated with subdural hematoma or effusion might disappear. For the arachnoid cyst to disappear, the rupture of the cyst wall appears to be essential, and after rupture, subdural effusion must develop around the cyst. As this effusion is absorbed, the fluid in the cyst drains away, after which the cyst becomes smaller and gradually disappears. This hypothesis supports the possibility of a "natural cure" for arachnoid cysts without surgical intervention.

Enteric viral infections in pre-school children in Karachi, Pakistan

A prospective study was conducted in Karachi, Pakistan on the virology of enteropathogens excreted by children with acute gastroenteritis and the results were compared with a control group of healthy children. Rotavirus and Adenovirus detection was done using ELISA techniques, while enterovirus isolation was done by virus culture. In 1990, 12.3% children with acute watery diarrhoea excreted rotavirus, as compared to 24.4% children in 1991. None of the healthy children excreted adenovirus 40 and 41. Preliminary results of 1992 revealed that rotavirus was seen in 13% of children with acute watery diarrhoea and adenovirus in 10% of children. Enteroviruses were isolated in the same frequency in all three groups i.e. children with acute watery diarrhoea, children with poliomyelitis and healthy children. Non-polio enteroviruses were excreted in 50-52% in all the 3 groups. The rate of enterovirus excretion is much higher than seen in other developed countries and is the same in children with diarrhoea and healthy children.

[A case of subarachnoid hemorrhage with acute subdural hematoma due to head injury: a case report]

Acute intracranial hemorrhages can be caused by cerebrovascular disease or head injury. Diagnostic imaging is in both cases sometimes similar, so it is difficult to make an exact diagnosis. We report a case of acute subdural hematoma due to head injury after loss of consciousness due to an aneurysmal rupture. A 52-year-old male was found out fallen on the floor in a state of unconsciousness and was brought to the nearest hospital. CT scan showed subarachnoid hemorrhage with left acute subdural hematoma and he was transported to our hospital. Angiography revealed a left MCA aneurysm. The next day, a clipping operation was performed but brain contusion was observed in the left frontal lobe. Postoperative CT scan showed contusional hematoma at the left frontal lobe and plain skull X-ray films demonstrated a diastatic fracture of the right lambdoid suture. Acute subdural hematoma due to the rupture of a cerebral aneurysm is sometimes recognized, but the first CT findings are similar to those observed after head injury. When the clinical course of onset is unclear, we must keep in mind that the cause of acute subdural hematoma may be head injury, even if angiography demonstrates abnormal vessels.

Bactericidal effect of rat cystatin S on an oral bacterium Porphyromonas gingivalis

We tested antibacterial and antiviral activities of rat cystatin S, a cysteine proteinase inhibitor, belonging to the family 2 cystatins against 18 different bacterial species and poliovirus type 1 (Sabin). Rat cystatin S specifically inhibited the growth of a human oral anaerobic bacterium Porphyromonas gingivalis due to a bactericidal effect.

[Viral etiology in travellers' diarrhea]

Virological examinations were performed on stools obtained from 1,264 overseas travellers with diarrhea at Nagoya International Airport between 1986 and 1991. Group A rotavirus was detected in 11 samples (0.87%) by latex agglutination method, but other viral agents such as atypical rotaviruses and small round structured viruses were not observed by electron microscopic analysis. Rotaviruses were detected in various age groups, but the positive rate of rotavirus in females (6/398) was higher than that in males (5/866). Seasonal variation in the detection of rotavirus was observed. Entero 71 was isolated from one of 11 rotavirus-positive cases, but the other 10 cases were not associated with enteroviruses. All rotavirus-positive cases were negative for isolation of enteropathogenic bacteria.

Differentiation between wild and vaccine-derived strains of poliovirus by stringent microplate hybridization of PCR products

Procedures for differentiation between wild and vaccine-derived strains of poliovirus are required, particularly in countries where wild and vaccine-related strains coexist. For this differentiation, we tested the method of Inouye and Hondo (S. Inouye and R. Hondo, Arch. Virol. 129:311-316, 1993) for discrimination of closely related viruses by using stringent microplate hybridization of PCR products. We used a pair of primers with enterovirus common sequences (between these primers there is a variable region for capsid proteins) for PCR using templates from wild and vaccine-derived poliovirus strains which were isolated in tissue culture and serotyped by neutralization assay. We also used the same primers for preparation of probes, which were labelled by incorporation of biotin-dUTP in the PCR, with the three original Sabin vaccine virus strains used as templates. The amplified DNAs from the isolates were immobilized on microplate wells and were then hybridized with the labelled probes. We found that, under the usual hybridization conditions, the Sabin vaccine virus strain probes hybridized with both wild and vaccine-derived viruses, but under stringent conditions, they reacted only with vaccine-derived viruses of the same serotype, clearly differentiating these from wild-type viruses.

Prevalence of newly isolated, cytopathic small round virus (Aichi strain) in Japan

Cytopathic small round virus (Aichi strain), isolated from a patient with oyster-associated gastroenteritis, showed no reaction in the polymerase chain reaction method for enteroviruses or in the enzyme-linked immunosorbent assay (ELISA) for the five serotypes of astroviruses. Our ELISA was sensitive in detecting the Aichi strain antigen in stool samples, but there was no reaction in this ELISA with any non-Aichi strains of enteric viruses, with such origins as enterovirus, rotavirus, Norwalk virus, calicivirus, or astrovirus. In the ELISA, 13 of 47 stool samples from adult patients in five of nine oyster-associated gastroenteritis outbreaks were positive, but only 1 of 397 pediatric stool samples in Aichi Prefecture was positive. The prevalence rate for Aichi strain antibody was found to be 7.2% for persons aged 7 months to 4 years. The prevalence rate for antibody to Aichi strain increased with age, to about 80% in persons 35 years old. On the basis of the results of the present study, it was hypothesized that Aichi strain could be a new type of small round virus that mainly produces diarrhea in patients in the 15- to 34-year-old age group, 50 to 76% of whom possess neutralizing antibody.

Virological and serological studies on poliomyelitis in Karachi, Pakistan. I. Outbreaks in 1990-91

Between October 1989 and September 1991, 124 cases of poliomyelitis visited the Department of Paediatrics, Civil Hospital Karachi, Pakistan. The majority of them were between 6 months and 2 years of age and the epidemics occurred during the hot seasons. The dominant serotype was poliovirus type 1 during the epidemic season in 1990 and type 2 in 1991. All the polioviruses isolated from the patients were wild-type. Virological studies also disclosed that enteroviruses other than polioviruses were prevalent among healthy children as well as among diarrheal and polio patients. A serological survey to elucidate the serological efficacy of oral polio vaccine (OPV) showed that: (i) in 112 unimmunized children, after disappearance of transplacental maternal antibody during early infancy, antibody prevalence increased gradually and > 80% of the children were seropositive against all three types of polioviruses at 5 years of age; (ii) in 201 children immunized with full doses of OPV in their infancy, the decrease in antibody titer during infancy was less and seroprevalence rose sharply afterwards: at 2 years of age, > 80% of them were seropositive against all three types of the virus. The rapid increase of seroprevalence might be the effect of OPV administration. However, the prevalence was lower than that in developed countries.

[The relationship of clinical manifestations and age distribution in enterovirus infections--viral isolation and seroepidemiology in Aichi Prefecture]

We studied the epidemiology of enterovirus infection in Aichi Prefecture from 1985 to 1989. We examined the age distribution of aseptic meningitis patients (AM) and exanthematous disease patients (Ex) and a seroepidemiological study of echovirus type 7 (E7), E9, E18 and group A coxsackievirus type 9 (CA9), was performed. The results is as follows: 1) E7, E9, E18 and CA9 were isolated from AM and Ex but E6, E11 and group B Coxsackie viruses (CB) were isolated in fewer cases from Ex. 2) The AM was consistently increased from June to August. Whereas the Ex was seen in all seasons but a slight increase was noted between June to July, and enteroviruses (EV) isolation was increased in this season. 3) The AM occurred in 0 year olds and 4 year olds whereas the Ex was seen in 0 to 1 years. EV was mainly isolated from 0-1 year olds. 4) The relationship of clinical manifestations and age was very clear in E9 and E18, a higher proportion of children at 1 years or under were those of the Ex and most children of the latter part of 4 years were those of the AM. The Ex had the same results with E7 and CA9 but AM was increased in 0 years and 4 year olds. 5) We studied the age distributions of neutralizing antibodies against E7, E9, E18 and CA9. The positive rate of neutralizing antibody after prevalence rose between 2-5 years of age. There were few patients among the 2 to 3 year olds but the neutralizing antibody was raised in this age. I considered that reason the enteroviruses infected mainly the 2 to 6 year olds showing no clinical symptoms where as some of the 3 year olds had aseptic meningitis and some under 1 year had symptoms of exanthematous diseases.

Immunohistological quantitative analysis of S100 protein-positive cells in T-cell malignant lymphomas, especially in adult T-cell leukemia/lymphomas

S100 protein-positive cells (S100+ cells) in 36 cases of T-cell lymphoma (T-ML) in the lymph node and 15 cases of T-ML in the skin were analyzed immunohistologically in order to study their quantitative features in adult T-cell leukemia/lymphoma (ATLL). The T-MLs were categorized according to the updated Kiel classification, and the T-cell pleomorphic type (Pleo) was subcategorized into 3 subtypes: Pleo-ATLL, Pleo-clear and Pleo-others. The population of S100+ cells and the first to fifth minimal distances of every S100+ cell were measured on micrographs of paraffin sections that had reacted to anti-S100 protein antibody according to the ABC method. Lymphoblastic and chronic lymphocytic leukemia types showed low populations of S100+ cells and long values of the first minimal distance. T-zone lymphoma without follicles and angioimmunoblastic lymphadenopathy with dysproteinemia-type T-ML had high populations and low values of the first minimal distance. Among the three subtypes of Pleo in the lymph node, Pleo-ATLL gave the highest population and the shortest value of the first minimal distance of S100+ cells, but this trend was not found in the skin. Clusters of more than five S100+ cells were more common in the Pleo-ATLL subtype than in the other two subtypes. The increase and clustering of S100+ cells in Pleo-ATLL suggests that the lymphoma cells act on S100+ cells as a helper.(ABSTRACT TRUNCATED AT 250 WORDS)

[Family-acquired hepatitis A--prevalence of hepatitis A among the family in Aichi Prefecture, 1990]

We studied the transmission of hepatitis A virus (HAV) in 45 families, which members were diagnosed as hepatitis A in 8 hospitals in 1990. Feces and sera from 50 patients and their 126 family members were tested for HAV-specific antigen and IgM antibody by ELISA or polymerase chain reaction (PCR) technology. From the interval of the onset of hepatitis or detection of HAV antigen in feces, HAV transmission was recognized in 11 (24.4%) of 45 families. The transmission was found to be concerned with contacts of the children and that from children to parents was found in 4 families and the reverse in 2. HAV antigen was detected from feces of 4 family members before onset of icterus by ELISA and furthermore, 3 by PCR. It was indicated that these methods would be used to prevent the transmission in a family, day-care centers, or institutions for the mentally retarded.

Adenovirus infection and specific secretory IgA responses in the intestine of infants

We investigated adenovirus (Ad) infection of the intestine and Ad group-specific fecal IgA antibody responses in seven infants who were followed up from birth to 16 months to seven years of age. We isolated in tissue culture from fecal samples not only enteric Ad type 41 but also other Ads (types 2, 3, 5, 6, and 12). We also detected Ad antigens in the feces by ELISA at the times of infection with even non-enteric Ads, suggesting that a large amount of antigens were produced in the intestine. We found that repeated Ad infections with different serotypes were occurring and there were good fecal IgA antibody responses at each time. The infection seemed usually mild or asymptomatic: only one out of 23 occasions of the detected infections required hospitalization.

A 2-year survey of the prevalence of enteric viral infections in children compared with contamination in locally-harvested oysters

We studied, for two years, the prevalence of indigenous human enteric viruses in wild oysters gathered each month from the bottom of Mikawa Bay, Aichi Prefecture, Japan. Viruses were detected periodically in 9 out of 54 oyster pools prepared by the acid or polyethylene glycol precipitation method although all these 9 pools met current national bacteriological safety standards. Since most of the serotypes of the enteric viruses detected in the oysters were identical with those of viruses isolated from sick children living in the area, it is suggested that contamination of enteric viruses in the oysters would depend on the prevalence of enteric viral infections in the local inhabitants.

Isolation of cytopathic small round viruses with BS-C-1 cells from patients with gastroenteritis

Fecal extracts from 12 subjects in outbreaks of oyster-associated nonbacterial gastroenteritis were inoculated with BS-C-1 cells for isolation of the causative viruses. Cytopathic agents were isolated from 3 patients. No cross-neutralizing reactions were observed between the isolates and prototypes of human enteroviruses. The isolates were approximately 30 nm in diameter and had a distinct ultrastructure resembling that of astroviruses. Four polypeptide bands with molecular sizes of 42, 28, 27, and 22 kDa were seen on SDS-PAGE analyses. Seroconversion against the isolate was observed in 18 (31.6%) of 57 patients involved in five of seven outbreaks examined by neutralization test. A protein band characteristically reactive with the paired serum samples was detectable at 42 kDa by immunoblot assay. These results suggested that some small round viruses resembling astroviruses might show cytopathic effect in BS-C-1 cells and may be associated with an oyster-related gastroenteritis.

A large outbreak of gastroenteritis associated with a small round structured virus among schoolchildren and teachers in Japan

In March 1989 a large outbreak of acute gastroenteritis occurred simultaneously among schoolchildren and teachers at nine elementary schools in Toyota City, Japan. Illness was observed in 3236 (41.5%) of 7801 schoolchildren and 117 (39.4%) of 297 teachers. The main clinical symptoms were diarrhoea, vomiting, nausea and abdominal pain. Gastroenteritis was significantly associated with the consumption of school lunch served by one particular lunch preparation centre. One food handler at the centre suffered from gastroenteritis during the outbreak. Small round structured virus (SRSV) was detected in 4 of 8 stool specimens from sick persons. The school lunch contaminated by the infected food handler is the most probable source of this outbreak due to SRSV.

[Microbiological and chemical analyses of indoor swimming pools and virucidal effect of chlorine in these waters]

Virological and bacteriological examinations and chemical analysis were made of 24 water samples from 6 public indoor swimming pools in Aichi Prefecture. In 3 of these swimming pools, sodium hypochlorite was used as a disinfectant and in the remainder trichloroisocyanurates. All samples were negative for adenovirus per 20 liters. Coliform group was detected in one sample with 26.7 mg/l cyanuric acid. Total plate counts ranged from 0 to 1 per ml in the swimming pools treated with sodium hypochlorite and 0 to 51 in those with trichloroisocyanurates. Turbidity, pH and potassium permanganate concentrations in the samples were within allowable limits. Seven of 24 samples did not meet the recommended value of 0.4 mg/l for free chlorine residuals. Ammonium nitrogen was detected in one pool water with trichloroisocyanurates. In 11 of 12 water samples of swimming pools using sodium hypochlorite, poliovirus 1 (2 x 10(4) PFU/0.2 ml) was inactivated within 1 min under the condition of 1.0 mg/l free available chlorine and 25 degrees C. In 11 of 12 water samples of 3 swimming pools using trichloroisocyanurates, poliovirus type 1 survived after 2 min contact while in 5 samples poliovirus type 1 survived after 5 min contact. This shows that the risk of viral infection is greater in swimming pool water treated with chlorinated isocyanurics than that with sodium hypochlorite. The operator of the swimming pool should pay special attention to the control of water quality and free residual chlorine value.