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H M Mathews

Publications and source records attributed to H M Mathews.

At least 37 records · Page 2Linked to original sources
PubMed1983

Evaluation of two serological tests for Trichomonas vaginalis infection.

Trichomonas vaginalis is a widely prevalent, sexually transmitted protozoan infecting both males and females. Despite its prevalence, little is known about its contribution to the morbidity rates for urogenital-tract infections. Currently accepted diagnostic methods are limited to the demonstration of the organism in fresh material, identification in stained material, or in vitro cultivation of organisms from the urogenital tract. We have evaluated the indirect hemagglutination test and the gel diffusion test for efficacy in detecting antibodies in serum samples drawn from two population groups. Sera from patients attending a vaginitis clinic had a seropositivity rate of 69% by indirect hemagglutination and 34% by gel diffusion. Seropositivity rates among culture-positive patients were 78% with indirect hemagglutination and 43% with gel diffusion. A group of normal female hospital employees showed seropositivity rates of 30% by indirect hemagglutination and 3% by gel diffusion. Absorption of reactive sera with Trichomonas antigens reduced or abolished the serological reactivity, confirming the specificity of the test. Serological methods can provide a rapid, sensitive, and economical tool to study the epidemiology of this common protozoan infection.

Antigens↗
PubMed1983

Polyacrylamide gel electrophoresis of isoenzymes from Entamoeba species.

In this preliminary report, we describe a polyacrylamide gel electrophoresis technique for the resolution of isoenzyme patterns of four isolates of Entamoeba histolytica and one isolate of Entamoeba coli. Our findings were similar to previous findings for three enzyme systems: maleic enzyme (malate dehydrogenase [EC 1.1.1.40]), hexokinase (EC 2.7.1.1), and phosphoglucomutase (EC 2.7.5.1). We found preliminary evidence that glucosephosphate isomerase (EC 5.3.1.9) may also differentiate invasive amoebae from noninvasive amoebae, when the isoenzymes are separated by polyacrylamide gel electrophoresis, whereas this differentiation is not evident with starch-gel electrophoresis. We used an Rf system to relate isoenzyme band mobility to the migration distance of a standard E. histolytica strain (HK-9). The numerical identification of isoenzyme bands can simplify the grouping of isolates into zymodemes.

Electrophoresis, Polyacrylamide Gel↗
PubMed1983

Isolation of two strains of Acanthamoeba castellanii from human tissue and their pathogenicity and isoenzyme profiles.

Two strains of amoebae, one (CDC:0180:1) from the lung tissue of a patient who died of granulomatous amoebic encephalitis and the other (CDC:0179:1) from the debrided tissue of a mandibular autograft, were isolated and identified as Acanthamoeba castellanii based on the morphological and immunofluorescent staining characteristics of the trophozoites and cysts. Both strains of amoebae caused cytopathic effects in mammalian cell cultures and destroyed the cell sheet. However, only the CDC:0180:1 strain, on intranasal instillation into mice, produced the disease manifested by ruffled fur and aimless wandering, followed by coma and death within 30 days. The CDC:0180:1 strain also differed consistently from CDC:0179:1 and another nonpathogenic A. castellanii strain (ATCC 30,011) in isoenzyme makeup, a dissimilarity which probably reflects its pathogenic potential.

Adult↗
PubMed1982

An outbreak of amebiasis spread by colonic irrigation at a chiropractic clinic.

From June 1978 through December 1980, at least 36 cases of amebiasis occurred in persons who had had colonic-irrigation therapy at a chiropractic clinic in western Colorado. Of 10 persons who required colectomy, six did. Of 176 persons who had been to the clinic in the last four months of 1980, 80 had received other forms of treatment. Twenty-one per cent of the colonic-irrigation group had bloody diarrhea, as compared with 1 per cent of the non-irrigation group (P = 0.00013). Thirty-seven per cent of the colonic-irrigation group who submitted specimens had evidence of amebic infection on either stool examination or serum titer, as compared with 2.4 per cent in the non-irrigation group (P = 0.00012). Persons who were given colonic irrigation immediately after a person with bloody diarrhea received it were at the highest risk for the development of amebiasis. Tests of the colonic-irrigation machine after routine cleaning showed heavy contamination with fecal coliform bacteria. The severity of disease in this outbreak may have been related to the route of inoculation.

Adult↗
PubMed1982

A longitudinal study of malaria antibodies in a Malaysian population. I. Group responses.

The indirect hemagglutination test was used to measure malaria antibody levels in residents of an endemic area of Malaysia. Blood specimens were collected at 4-week intervals for a year. Seropositivity rates increased with age and number of episodes of malaria in young children. Although antibody levels were variable, titers tended to rise with parasitemia and fall in the absence of detected parasites. In general, the serologic indices tended to reflect the parasitologic findings.

Adolescent↗
PubMed1982

A longitudinal study of malaria antibodies in a Malaysian population. II. Follow-up of individuals.

A cohort of 62 persons living in a malaria-endemic area was examined by serology and by blood film 14 times over a 56-week period. Serologic responses (indirect hemagglutination test) of the group as a whole reflected the malaria transmission as determined by blood slide examination. The serologic responses of individuals showed titer changes that were not always consistent with blood slide results. The use of chloroquine may have modified the host's immune response.

Adolescent↗
PubMed1981

Duffy blood types and vivax malaria in Ethiopia.

We investigated an hypothesis relating the Duffy-negative blood type with insusceptibility to vivax malaria--and previously associated only with people of West African ancestry--in three population samples of eastern African stock. The samples included Nilotic and Hamitic-Semitic residents of a malarious locale in Ethiopia and Hamito-Semites in Addis Ababa where malaria is not endemic. Fresh red blood cells from 191 subjects were tested with Duffy antisera, anti-Fya and anti-Fyb. Duffy-positive rates in the malarious community were 8% for the Nilotes and 70% for the Hamito-Semites; the Hamito-Semites in Addis Ababa were 98% Duffy-positive. The relative prevalences of Plasmodium vivax in the two study groups at risk to malaria were 2.4% for the Nilotes and 27.3% for the Hamito-Semites, producing a ratio similar to the ratio of Duffy-positive in the two samples. We interpret the data as supportive of the Duffy-vivax hypothesis with reference to a part of eastern Africa, and we suggest that the Duffy-negative genotype may represent the original, rather than the mutant, condition in tropial Africa.

Adolescent↗
PubMed1981

Serologic and parasitologic studies of Entamoeba histolytica in El Salvador, 1974-1978.

Serologic and parasitologic studies were done in El Salvador, C.A., from 1974-1978 to examine the reliability of the diagnosis of Entamoeba histolytica infection in an endemic area and to confirm the estimates of morbidity and mortality due to amebiasis. The results suggest that infection with E. histolytica is common, but the estimated prevalence is too high. Misdiagnosis occurring in hospital and public health laboratories was documented. Data collected from examining family members of persons with E. histolytica infection and disease indicate that most infections are asymptomatic, and support the hypothesis that estimates of morbidity and mortality rates are excessive.

Adolescent↗
PubMed1978

Longitudinal serological study of malaria in infants in the West African savanna. Comparisons in infants exposed to, or protected from, transmission from birth.

Two infant populations, the one exposed to intense malaria transmission and the other protected, were followed and compared by six serological tests. The IgG and IgM levels increased with age and were systematically, though only slightly, lower in the protected children. The results of three Plasmodium falciparum tests (precipitin, indirect fluorescent antibody (IFA) and indirect haemagglutination and one P. malariae test (IFA) were high at birth and decreased rapidly afterwards in both populations. In the unprotected population, this decrease was followed by an increase, closely associated with the parasitological findings, while in the protected population the decrease continued to very low levels.

Africa, Western↗
PubMed1978

Changing patterns in the humoral immune response to malaria before, during, and after the application of control measures: a longitudinal study in the West African savanna.

A longitudinal seroimmunological investigation of malaria was performed as part of the WHO research project conducted in the northern part of Nigeria from 1970 to 1975. The project included a preintervention phase, an intervention phase with application of malaria control measures (spraying of residual insecticide and mass drug administration), and a postintervention phase. Serological observations were made on the total population of eight villages consisting of approximately 3000 persons. Six immunological parameters were studied, namely, the serum levels of IgG and IgM, the number of bands of precipitation for Plasmodium falciparum in the double diffusion (Ouchterlony) test, the titres of antibodies for P. falciparum and P. malariae in the indirect fluorescent antibody (IFA) test, and the titres of agglutinating antibodies for P. falciparum by the indirect (passive) haemagglutination (IHA) test. The serological results were used to evaluate the impact on the humoral immune response of different levels of parasitaemia resulting, in the unprotected population, from natural factors such as seasons and ageing and in the protected population, from human intervention through the application of control measures and their interruption. The linkage by computer processing of the longitudinal data allowed analysis of the relationship between the results of a serological test in the same person at different surveys, and analysis of correlation between serological results and the concurrent parasitological findings. The correlation between parasitaemia and the results of the different serological tests at the same survey in the same person were also examined and analysed in terms of sensitivity and specificity of the tests.

Adolescent↗
PubMed1976

Malarial antibodies measured by the indirect hemagglutination test in West African children.

The indirect hemagglutination test with Plasmodium falciparum antigen was used to measure malarial antibodies in filter paper blood specimens from 527 West African children. A slight decline in antibodies was noted in 6- to 8-month-old children wh o had no malaria parasites in their blood smears. Children older than 10 months had similar antibody levels regardless of the presence or absence of demonstrated parasites in blood smears.

Africa, Western↗
PubMed1976

Plasmodium brasilianum antigen for use in the indirect hemagglutination test.

Antigen was prepared from Plasmodium brasilianum harvested from an infected spider monkey. This antigen was attached to aldehyde-fixed, human type O cells, and was tested against sera from human cases of P. malaria, P. vivax, P. falciparum, and P. ovale infection, and sera from noninfected persons. At dilutions of 1:16 or greater the antigen failed to react in sera from noninfected persons. It reacted at titers of 16 or above with sera from 85% of the persons with P. malariae infection, 83% with P. vivax infection, 70% with P. falciparum infection, and 70% with P. ovale infection.

Antigens↗
PubMed1976

Seroepidemiologic investigations of malaria in Guyana.

The results of longitudinal seroepidemiologic malaria surveys with the indirect haemagglutination test in four sectors in the interior of Guyana did not suggest recent malaria transmission. Indigenous malaria cases had not been detected in these sectors since 1968 but malaria surveillance here had been incomplete. The multi-stage cluster sampling method used proved to be efficient and permitted the survey of a large and sparsely populated area to be concentrated in relatively few localities. Observation of a group of 147 seropositive and seronegative persons after one year showed a four-fold or greater decline of antibody titres in five per cent of the cohort population and no such titre increases were seen, thus confirming the absence of recent malaria infections. Seropositivity rates were higher in persons with a history of malaria than in those without such a history. Collecting blood on filter paper facilitated obtaining material for serologic testing especially in the younger age group and no refusals were encountered. This advantage compensates for the slight loss in sensitivity when filter paper eluates are titrated instead of sera. The difference between the past infection probabilities of the age groups over and under 20 years old suggests that the disappearance of malaria from the interior was related more to the elimination of malaria transmission along the coast than to the specific malaria campaign in the interior.

Adolescent↗
PubMed1976

Hepatitis BS antigen, malaria titers, and primary liver cancer in South Vietnam.

A total of 306 individuals from South Vietnam were studied: 61 had a diagnosis of primary liver cancer (38 had a tissue diagnosis, and 23 had a clinical diagnosis and a positive alpha-fetoprotein); 9 had viral hepatitis; 101 were hospitalized patients (60 with various other forms of liver disease and 41 without liver disease); 94 were blood donors; 29 were drug users, and 12 were medical students. Alpha-fetoprotein was present in 45 of 61 (74%) of those with a diagnois of primary liver cancer (PLC) and in none of the other patients. Using immunoelectroosmophoresis, hepatitis BS antigen (HBSAg) was found no more frequently in those with PLC than in the other groups studied. In contrast, using a radioimmunoassay technique HBSAg was present 3 to 8 times as frequently in the PLC patients as in other subjects without viral hepatitis. There was a close relationship between the presence of alpha-fetoprotein and HBSAg in the patients with PLC. Malaria seropositivity rates were no different in the PLC groups than the other groups. It appears that in South Vietnam PLC is associated with an increased frequency of HBSAg.

Adolescent↗
PubMed1975

Profile of perceptual-cognitive traits and personality style of possible relevance to creative productivity.

The amount of illusory movement perceived on the autokinetic test, manifestations of primary process expression on the Rorschach, and creative productivity as measured by the Torrance Tests of Creative Thinking, were collected from 47 volunteer college students. Those individuals who expressed primary process thinking as blatant affect and the fusion of images, and elaborated on a stimulus pictorially, had extensive movement on the autokinetic test (P less than .05). We further delineated certain personality characteristics of these individuals employing a 26-item bipolar questionnaire. They are among other things, active, striving, assertive, in touch with and free to express emotion, rebellious, incautious, self-determing, productive, motivated to influence others, and excelling in producing objects or ideas which are unique.

Adult↗
PubMed1975

The indirect hemagglutination test for malaria. Evaluation of antigens prepared from Plasmodium falciparum and Plasmodium vivax.

Soluble antigens were prepared from Plasmodium falciparum and P. vivax and were evaluated in the indirect hemagglutination test. These antigens, attached to aldehyde-fixed type "O" erythrocytes, detected antibodies in more than 91% of infections with the homologous Plasmodium species. Detection rates in infections caused by the heterologous species ranged from 72% to 76%. Positive reactions occurred in less than 2% of sera from persons without malaria infection.

Animals↗
PubMed1975

Comparison of the complement fixation, indirect immunofluorescence, and indirect hemagglutination tests for malaria.

The complement fixation (CF), indirect immunofluorescence (IIF), and indirect hemagglutination (IHA)tests for malaria were compared by using sera from U.S. citizens with either natural infections or heroin-associated, needle-induced infections. In natural Plasmodium vivax infections, the CF, IIF, and IHA tests apparently detect malarial antibodies equally efficiently for the first 2 months after the onset of symptoms, but the titers obtained by CF and IIF rapidly decline within a year, while the IHA titers remain elevated. In the sera from heroin addicts who developed needle-induced P. vivax infections, sensitivities of all three tests were decreased: the IIF and IHA tests each detected 83%, but the CF test detected only 57.1%. False-positive reactions with this group were very high for the CF (76.6%) and IHA (15.9%) tests, but only 2% for IIF.

Antibodies↗