[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.