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Biomedical subjects

J H Cross

Publications and source records attributed to J H Cross.

At least 163 records · Page 9Linked to original sources
PubMed1976

Toxoplasmosis in man and animals in South Kalimantan (Borneo), Indonesia.

Sera from 1,050 persons, 69 cats, 18 goats, 23 bovines, 2 monkeys, and 1 dog from 7 villages in South Kalimantan were tested for indirect hemagglutination Toxoplasma gondii antibodies. A seroepidemiologic study with the methylene blue dye test was conducted 1 year later at one village among 25 families and their cats. Toxoplasma antibody prevalence in man in different villages varied from 9.7% to 51.0%. Forty-one percent of the cats and 61% of the goats also had positive titers. None of the bovines was positive. The epidemiologic study indicated that, in spite of the presence of many infected cats in the village, goat meat was a significant source of Toxoplasma infection for man in this population.

Adolescent↗
PubMed1976

Japanese encephalitis virus in Northern Taiwan, 1969-1973.

Sentinel pigs were bled and mosiquitoes were collected for isolation of Japanese encephalitis virus (JEV) between 1969 and 1973 in a rural area of northern Taiwan which reported a high annual incidence of human cases. The study site included a farmyard, schools, a bat cave, rice paddies and a heronry. Although Culex annulus was collected in every month of the year, isolations were made only in midsummer and only from Culex annulus and (once) from Culex tritaeniorhynchus. These isolates were usually collected from pig-related sources. Human cases in the vicinity of the study site were reported 3 to 6 weeks following the initial isolations from sentinel pigs. Isolations were made only for 4 to 8 weeks each summer. The isolation of JEV was not related to the availability of susceptible pigs or the spring or summer peaks in prevalence of Culex annulus. Despite periodic draining of rice paddies and the application of insecticides, sufficient numbers of Culex annulus were available to support transmission of JEV in each year of the study.

Animals↗
PubMed1976

Toxoplasma gondii haemagglutinating antibody titers in Indonesian goats.

Sera of 465 goats from several of the Indonesian islands were tested for indirect haemagglutinating (IHA) antibodies to Toxoplasma gondii. Titers greater than or equal to 1:16 were found in 24% of the animals with approximately 11% having titers of greater than or equal to 1:256. Sera from pigs, cows, water buffaloes and horses were also tested and only pig sera had IHA antibodies at titers above greater than or equal to 1:16. The possible role of goats in transmission of toxoplasmosis is discussed briefly.

Agglutinins↗
PubMed1976

Preliminary observations on the biology of the Indonesian strain of Schistosoma japonicum: animals and oncomelanid snails.

Laboratory animals and subspecies of Oncomelania hupensis were exposed to experimental infections with a strain of Schistosoma japonicum from the Lindu Valley, Central Sulawesi, Indonesia. All laboratory animals given 50 cercariae were suspecptible to infection with the greatest number of worms being found in mice followed by Wistar rats, Long Evans rats, Mongolian gerbils, wild rats, hamsters and guinea pigs. Rabbits and the Taiwan monkeys given larger numbers of cercariae were also susceptible to infections. Adult worms were found to reach the largest size in the rabbit and Taiwan monkeys but many worms from rats were immature. Eggs from the Taiwan monkey were larger than those from a dog and from mice. Six subspecies or geographic strains of Oncomelania hupensis were exposed to 3 to 5 miracidia of the Indonesia strain of Schistosoma japonicum and only Oncomelania hupensis lindoensis and Oncomelania upensis chiui from Taiwan were susceptibile and produced cercariae while Oncomelania hupesis formosana from Changhua, Ilan and Kaohsium countries of Taiwan as well as Oncomalania hupensis quadrasi from the Philippines were considered refractory to infection.

Animals↗
PubMed1976

Malic dehydrogenase patterns in different strains of Schistosoma japonicum and subspecies of Oncomelania hupensis.

Malic dehydrogenase (MDH) of the Formosan Philippine and Indonesian Strains of Schistosoma japonicum and 3 subspecies of snails, Oncomelania hupensis formosana, O. h. quadrasi, and O. h. lindoensis were identified by disc electrophoresis with 10.5% acrylamide gel columns using tris-malic buffer. Male worm extracts of S. japonicum demonstrated 3, 2, and 2 clear MDH patterns and female worm extracts showed patterns of 2, 1 and 1 for the Formosan, Philippine and Indonesian strains of the parasite, respectively. MDH patterns were the same for all 3 subspecies of snails; one major and one minor band being found in all.

Electrophoresis, Polyacrylamide Gel↗
PubMed1976

Comparison of some methods for the detection of antigen-antibody reactions in amoebiasis.

The indirect hemagglutination test (IHA) and counterimmuno-electrophoresis (CIE) were used to test for antibodies to Entamoeba histolytica in human sera using antigens from axenic cultures of the HK9 strain. Correlation between the test was excellent with most sera from patients with amoebiasis demonstrating precipitin lines by CIE at IHA titers considered diagnostically positive, larger than or equal to 1:128. Precipitin reactions with positive sera were also compared by CIE, immunoelectrophoresis (IEP) and two-dimensional electrophoresis is (2D-IEP). The greatest number of antigen-antibody components were demonstrated by 2D-IEP. Further studies utilizing 2D-IEP should be of value in the antigenic analysis of E. histolytica.

Amebiasis↗
PubMed1976

Parasitic infections in humans in West Kalimantan (Borneo), Indonesia.

A survey was carried out among inhabitants of eight villages in West Kalimantan Province (Borneo), whereby blood smears were examined for malaria, stools examined for intestinal parasites and sera tested by the indirect hemagglutination test for antibodies to Entamoeba histolytica and toxoplasma gondii. The prevalence of malaria among 3017 people examined was 5.6% (Plasmodium vivax 2.8%, Plasmodium falciparum 2.8%). Brugia malayi microfilariae were found in 3.6% and Wuchereria bancrofti in 0.3%. Ninety-seven percent of 2101 stool specimens examined contained evidence of intestinal parasites. Trichuris trichiura (90%) was most common followed by Ascaris lumbricoides (76%), hookworm, (60%), Etamoeba coli (23%), Entamoeba histolytica (6%), Endolimax nana (6%), Iodamoeba butschlii (4%), Giardia lamblia (3%), Chilomastix mesnili (1%) and Strongyloides stercoralis (1%). Other parasites found were Entamoeba hartmanni, Trichomonas hominis, Balantidium coli, Enterobius vermicularis, Hymenolepis nana, Echinostoma sp. and Physalopterid, Dicrocoeliid, and Heterophyid type-eggs. The amoeba prevalence rate was 30%. Indirect hemagglutination antibody titers equal to or greater than 1:128 for Entamoeba histolytica and 1:256 for Toxoplasma gondii were detected in 7% and 3%, respectively, of 1511 sera tested.

Adolescent↗
PubMed1976

Congenital toxoplasmosis in Indonesia.

An 18-month-old male Indonesian with blindness, microphthalmia and bilateral cataracts was found to have antibody titers against Toxoplasma gondii of 1:512, 1:1024 and 1:1024 respectively by the indirect hemagglutination, indirect fluorescent antibody and Sabin-Feldman dye test. Serum from the child's mother by the same test also demonstrated antibody titers of 1:1024, 1:512 and 1:512 respectively. The clinical manifestations in the child and the presence of anti-toxoplasma antibodies in both mother and child suggest that the disease was congenitally acquired.

Adult↗
PubMed1976

Parasitology survey in northern Sumatra, Indonesia.

A parasitology survey was conducted in five villages in North Sumatra, Indonesia. A total of 3,207 blood smears, 2,066 stool specimens and 969 sera were examined. Sixty (1.9%) inhabitants had malaria (Plasmodium vivax 41, P. falciparum 19), and 20 had Brugia malayi microfilaraemia. The most common intestinal helminths were Trichuris trichiura (87%), Ascaris lumbricoides (75%) and hookworm (58%). Other helminths found in low numbers were Enterobius vermicularis, Strongyloides stercoralis, Taenia sp., Fasciolid, Dicrocoeliid and Echinostoma sp. eggs. Entamoeba coli (25%) was the most common intestinal protozoa followed by Endolimax nana (8%), Entamoeba histolytica (7%), Giardia lamblia (6%), Iodamoeba bütschlii (5%), Entamoeba hartmanni (1%) and Chilomastix mesnili (1%). The amoeba prevalence rate was 31 per cent. Testing of sera for Entamoeba histolytica and Toxoplasma gondii antibodies by the indirect haemagglutination test demonstrated positive reactors in 13 per cent and nine per cent of the population respectively. The greatest number of seropositives for Toxoplasma gondii was at elevations of sea level to five meters and the lowest number at elevations of 5OO-1,000 meters.

Adolescent↗
PubMed1976

New Oncomelania hupensis foci on Taiwan.

Six new areas for Oncomelania hupensis were found on Taiwan: three in Nan-tou, and 1 each in Chia-i, Hua-lien and Tai-tung counties. Most of the new habitats, unlike previously known areas, are not in alluvial plains, but are at higher elevations. The Nan-shan-chi colony in Nan-tou county is located at the altitude of 740 m, which is the highest of all known Oncomelania localities on the island. Oncomelania has now been found in 9 out of 15 counties on Taiwan. Shell features of the newly-discovered snails resemble those of Oncomelania hupensis formosana but further study will be required for final subspecies designation. Nearly 60,000 oncomelanids from both old and new localities were examined for schistosome infection with negative results.

Animals↗
PubMed1975

The distribution and prevalence of group A arbovirus neutralizing antibodies among human populations in Southeast Asia and the Pacific islands.

Plaque reduction neutralization tests, using five group A arboviruses (chikungunya, Ross River, Getah, Bebaru and Sindbis), were done on sera from human populations in 44 Southeast Asia and Pacific island localities. Specificity of the plaque neutralization test was determined by examining convalescent sera from patients with known alphavirus infections. Chikungunya-specific neutralizing antibodies were demonstrated in sera of persons living in South Vietnam, Northern Malaysia, Indonesia (Kalimantan and Sulawesi), as well as Luzon, Marinduque, Cebu and Mindanao islands in the Philippines. Evidence of Ross River virus infection was found among populations living in West New Guinea and Papua New Guinea mainland, the Bismark Archipelago, Rossel Island and the Solomon Islands. There appeared to be no geographic overlap in the distribution of chikungunya and Ross River viruses, with the separation in their distribution corresponding with Weber's line in the Pacific. Sindbis neutralizing antibodies were found in 7 of 21 populations sampled, but in general the prevalence of infection was low. Four sera, from Vietnam, Malaysia and Mindanao gave monospecific reactions with Getah virus. No evidence of specific Bebaru virus infection was detected. The epidemiology of these five alphaviruses in Southeast Asia and the Pacific islands is discussed.

Adolescent↗
PubMed1975

Growth of Japanese encephalitis virus in Culex tritaeniorhynchus cell cultures.

Ovarian cells from the mosquito Culex tritaeniorhynchus established in continuous tissue cultures have been found to support the growth of Japanese encephalitis virus with titers reaching as high as 10(7.36) MICLD50 per 0.03 ml. Virus-cell cultures were serially subcultured 60 times over 300 days and the virulence of the virus was determined after each passage. A gradual loss in virus titer was observed, with titers always higher in the medium than in the cells. Cytopathogenic effects were not observed in the infected cell cultures, either in primary or subsequent passages. However, the cell growth rate suggested that the cells may have been metabolically or mechanically damaged. The chromosome complement of the cells remained unchanged. Direct-fluorescent antibody studies during early and late passages revealed a loss in virus infectivity from chronically infected cells which may have been due to a gradual decrease in virus replication as the passages increased. The infectivity of virus particles, however, returned to previous levels after passage into fresh cell cultures. The loss of virus particles during serial passage may be correlated with the condition of the cells.

Animals↗