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.

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.

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.

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.

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.

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.

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.

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.

Human serologic response to subcellular antigens of Trichomonas vaginalis.

Trichomonas vaginalis organisms were processed by differential centrifugation to yield defined subcellular fractions. The various fractions were processed by methods to enhance solubility of membranes and other components. The soluble materials were analyzed for immunogenicity by a quantitative kinetic enzyme-linked immunosorbent assay (k-ELISA) and the enzyme-linked immunoelectrotransfer blot (EITB) technique using human patient serum. The principal antibodies in the human serum were directed toward cytosol components, not against membrane components, although all fractions contained multiple antigenic moieties.

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.

Problems in day care surgery.

In-patient admission represents a failure of a day care service. The hospital records of 105 patients transferred from the day ward to the in-patient wards were studied retrospectively. Of 2,039 patients treated in the day care ward, 105 (5%) required in-patient admission over a 12 month period. Of these 105 admissions, 17% did not fulfil the criteria for day care patients, 46% had surgical problems, and 35% anaesthetic-associated problems. The in-patient admission rate could be reduced by improved out-patient selection of cases, use of a separate day care theatre, increased use of local anaesthetic techniques, reduction in the use of parenteral opioids, the use of simple oral analgesics or non-steroidal anti-inflammatory agents as pre-emptive analgesia and a wider use of propofol as an induction agent which provides superior recovery from anaesthesia.

Sodium bicarbonate as a single dose antacid in obstetric anaesthesia.

Gastric pH and volumes were measured in 84 women who had general anaesthesia for emergency Caesarean section. Forty-eight received only 20 ml 8.4% sodium bicarbonate immediately before induction of anaesthesia and 36 ranitidine 150 mg 6-hourly during labour in combination with NaHCO3. Gastric pH was less than 2.5 in four women who received only bicarbonate. All aspirates from the ranitidine plus bicarbonate group had a pH greater than 2.5. Mean volumes of gastric content aspirated were 87 (SD 87.4) and 60 (SD 46.3) ml for the bicarbonate alone and bicarbonate plus ranitidine series respectively. These differences were not significant. Twenty millilitres of 8.4% NaHCO3 cannot be recommended as a single dose antacid for emergency Caesarean section. Ranitidine plus bicarbonate is considered a reliable antacid regimen to ensure elevation of gastric pH to safe levels.

Field application to malaria studies of the passive haemagglutination (PHA) test with lyophilized cells.

Lyophilized cells for the passive (formerly indirect) haemagglutination test for malaria were tested in a small field trial. A comparison was made with results obtained with samples from the same persons by another method in another laboratory (Center for Disease Control, Atlanta, GA, USA). The use of lyophilized cells of standardized reactivity clearly adds to the simplicity and rapidity of the test, and justifies its recommendation for use in field studies.

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.

A fast electrophoretic isoenzyme technique for the identification of invasive and non-invasive Entamoeba histolytica and "E. histolytica-like" organisms.

Cellulose acetate electrophoresis (CAE) was used to separate glucosephosphate isomerase, hexokinase, malic enzyme, and phosphoglucomutase extracted from invasive and non-invasive Entamoeba histolytica and "E. histolytica-like" organisms. Each of these morphologically similar organisms possessed a unique CAE isoenzyme profile that can be used as an aid in their identification. The CAE technique used to obtain these isoenzyme profiles is rapid, simple, and economical, and it requires neither specialized training nor elaborate equipment.