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PubMed1979

HLA antigens in the Arab population of the Gaza Strip.

The HLA antigen system was studied in the Arab population of the Gaza Strip. The lymphocytes of 113 individuals were typed for 13 and 16 antigens at loci A and B, respectively. The distribution of the HLA antigens was found to be similar to that of an average Caucasoid Middle Eastern population. This was more marked when the tested population was compared with Arab populations living in northern Israel or originating from Lebanon, suggesting that they probably all share a common gene pool. The only noteworthy variation in the Gaza population was the high frequency of BW21, previously found only in Eritreans and Turks.

Gene Frequency↗

PubMed1979

Studies of the relationship between Schistosoma and their intermediate hosts. III. The genus Biomphalaria and Schistosoma mansoni from Egypt, Kenya, Sudan, Uganda, West Indies (St. Lucia) and Zaire (two different strains: Katanga and Kinshasa).

The compatibility between strains of Schistosoma mansoni from Egypt, Kenya, Sudan, Uganda, the West Indies, and Zaire (two strains which came from Katanga and from Kinshasa), and various species and strains of Biomphalaria, i.e. Biomphalaria pfeifferi, B. alexandrina, B. glabrata and B. camerunensis was investigated. Data as mortality, rate of infection of the surviving snails, duration of infection, cercarial production per day per positive snail, etc., were observed. The main emphasis was placed on determining the total cercarial production per 100 exposed snails for each snail population. It was possible to infect all the tested populations of B pfeifferi with the various strains of S. mansoni, but the observation as e.g. TCP/100 exposed snails varied greatly according to the population of snail and the strain of S. mansoni. The results for the remaining species of Biomphalaria varied greatly, depending on the combination, e.g. B. alexandrina was only susceptible to the local S. mansoni from Egypt. The highest TCP/100 exposed snails was more than 1 million for the strains of S. mansoni from Egypt, Kenya and the West Indies in B. alexandrina, B. pfeifferi and B. glabrata, respectively. The next group, with a TCP/100 exposed snails on 7--800 000 consists of S. mansoni from Sudan, Uganda and Zaire (Katanga) all in B. pfeifferi. The last tested strain of S. mansoni, Zaire (Kinshasa) yielded a cercarial production on 500 000 per 100 exposed snails in B. pfeifferi and B. camerunensis. The shortest prepatent period, 19 days, was observed for S. mansoni from Kinshasa, Zaire, in B. camerunensis, and the longest prepatent period, 25 days, was found for strains from Egypt and from the West Indies in B. alexandrina and B. glabrata, respectively. In general, a very long duration of infection, lasting up to 200 days, was observed.

Animals↗

PubMed1979

Benzimidazole resistance of equine stronygles--critical tests of six compounds against population B.

Critical tests were conducted on eight horses naturally infected with several species of large and small strongyles from population B. Tested were six benzimidazoles, including thiabendazole (2 lots) (44 mg/kg of body weight); mebendazole (8.8 mg/kg); cambendazole (two formulations) (20 mg/kg); fenbendazole (10 mg/kg); oxibendazole (10 mg/kg); and oxfendazole (10 mg/kg). All compounds were administered by stomach tube except one of the two cambendazole formulations which was an intraoral paste. Removal of large strongyles (when present), Strongylus vulgaris and Strongylus edentatus, was 100% by each drug. In general, five species of small strongyles (Cyathostomum catinatum, Cyathostomum coronatum, Cylicocyclus nassatus, Cylicostephanus goldi, and Cylicostephanus longibursatus) exhibited varying degrees of resistance (% removal) to all of the drugs except oxibendazole. A total of 19 other species of small strongyles from seven genera, including the three described earlier were about 100% removed by the six benzimidazoles. Poor removal of immature (fourth-stage larvae) forms was also characteristic of the six drugs.

Animals↗

PubMed1979

Genetic distances among the five tribal populations of Andhra, Pradesh, South India.

In this paper, data on genetic distances among five tribal populations ae given. Among the five tribes, Koya Dora, Raj Gond and Naikpod are autochthonous populations of the Deccan plateau whereas the other two groups, Pardhan and Lambadi are migrants. Kova Doras were sampled from five distant localities. Genetic markers typed are: A1A2B0, Rho(D) blood group systems glucose-6-phosphate dehydrogenase deficiency, transferrin, haptoglobin, groupspecific component, haemoglobin, colour-vision deficiency and tastability to P. T. C. Using frequency data for the above nine genetic loci, genetic distances between the five endogamous tribes, and between the five groups of Koya Dora are calculated by adopting the statistical method of Edwards (1971). While genetic distances between Koya Dora, Raj Gond and Lambadi are minimal, the genetic distance between Pardhans and other tribal groups is maximum. Naikpods occupy an intermediate position. The closeness of Lambadi with Koya Dora and RAJ Gond can be regarded as coincidental. Interestingly, the differences in the genetic distance values between five Koya Dora groups are as great as the differences between the five endogamous tribal populations tested for the same loci. Genetic affinities of these tribal populations are discussed in relation to their ethnic origin migration and geographical isolation.

Adult↗

PubMed1978

Cytotoxicity of synthetic fuel products on Tetrahymena pyriformis. II. Shale oil retort water.

Shale oil retort water is obtained by centrifuging the oil/water emulsion produced by oil shale retorting. The ciliate Tetrahymena pyriformis was exposed to retort water; 2, 1, and 0.5% initially increased motility; longer exposures decreased motility. Three, 4, and 5% all decreased motility. Cell lysis was directly related to concentration; after 24 h, population densities were 0, 10, and 25% of controls for 2, 1, and 0.5% retort water, respectively. Oxygen consumption paralleled the motility pattern: at lower concentrations it increased initially but decreased with extended exposures while at higher concentrations it decreased rapidly. The most striking cytologic alteration of cells exposed to the toxicant occurred in the membranes; alterations of mucocysts and glycogen content were also observed, but mitochondrial changes were not. Population growth was affected at much lower concentrations than the other test indices. The growth of test populations reached a plateau at values inversely related to concentration: concentrations less than 0.4% had no effect on growth rate.

Animals↗

PubMed1978

The immunoglobulin allotypes (Gm and Km) of twelve Indian tribes of Central and South America.

The Gm and Km immunoglobulin allotypes are presented, for the first time, for six South American Indian tribes (Baniwa, Kanamari, Kraho, Makiritare, Panoa, and Ticuna) and one Central American tribe (Guaymi). Additional allotype information is presented for five previously reported South American tribes (Cayapo, Piaroa, Trio, Xavante and Yanomama). The distributions of the Gm and Km allotypes among all the tribal populations tested to date are reviewed and evidence is presented for the presence of a north (high)-south(low) cline in Km frequency. The wave theory of the populating of the South American continent was tested by an examination of the distribution of six alleles (Gmax;g, Gma;b0,3,t,Dia,Rx,TFDChi, and 6PGDC), absent in some populations but with polymorphic proportions in others. The present, limited, data failed to confirm the theory.

Alleles↗

PubMed1977

Tactile sensitivity: development of a behavioral responses checklist.

Tactile defensiveness or sensitivity to being touched is a phenomenon observed by therapists during clinical testing and is reported based only on subjective data. The purpose of this study was to develop a more objective means of identifying this phenomenon. Videotaped observations of five-year-old boys being administered the Southern California Kinesthesia and Tactile Perception Test battery were used to identify behavioral reactions indicative of sensitivity to tactile stimulation. The population tested for a wide range of behaviors included hyperactive and normal five-year-old boys. These reactions were defined and categorized into a checklist of tactile-sensitive behaviroal responses. This checklist was then used on videotapes of 10 five-year-old boys by two raters to establish a measure of the reliability of this method of observing and recording behaviors. A reliability of .89 agreement with consensus was reached. These behavioral categories offer objective guides in identifying children with tactile defensiveness or sensitivity to tactile stimulation.

Child Behavior↗

PubMed1976

Chromosome studies in wild populations of D. melanogaster.

Chromosome studies of wild D. melanogaster populations from Missouri, Mississippi, Louisiana and Texas uncovered 58 inversions. Six were common and cosmopolitan; 52 were new, rare and generally endemic. In one of two Missouri populations tested, structurally heterozygous females carried significantly more sperm at capture than did the homozygotes. In both populations comparisons of wild sperms with the females carrying them indicated significant positive assortative mating and an excess production of homozygotes among the F1 progeny. Wild females structurally heterozygous in up to three major autosomal arms showed no associated nondisjunctional egg lethality; those heterozygous in all four arms produced from 0% to 24% dead eggs, suggesting the presence of intrapopulational gene modifiers of meiosis. Texas populations supported on windfall citrus fruit showed a slight but significant difference in inversion frequencies between flies breeding on oranges and those breeding on grapefruit. Within these populations inversions were not distributed at random among individuals; rather there was an observed excess of individuals carrying intermediate numbers, and a deficiency of those carrying very few or very many inversions. While there was no significant linkage disequilibrium associated with this central tendency, there was a significant interchromosomal interaction: flies carrying inversions in chromosome 2 tended not to carry them in chromosome 3, and vice versa.

Animals↗

PubMed1979

Clinical experience with brain stem audiometry performed under general anesthesia.

Hearing tests were given to 22 difficult-to-test children using brain stem audiometry performed under general anesthesia. The effect of halothane and sodium thiopental on the brain stem response was assessed as well as the feasibility of using this technique with a difficult-to-test population. No effect on brain stem responses was observed to various levels of anesthesia. Successful hearing tests were carried out on all the children and results were helpful in their management. Brain stem audiometry perfromed under general anesthesia appears to be an effective and helpful technique for testing challenging diagnostic cases.

Adolescent↗

PubMed1978

[Investigation of the immunity status towards tetanus of a population of mechanics at the car-factory "Renault" (author's transl)].

Tetanus immunity has been studied in a population of mechanics working at the car-factory "Renault". For the study, 283 individuals were divided into 3 groups. The first group consisted of non-vaccined individuals, the second of vaccinated individuals and the third of individuals who had been boostered. The influence of different parameters on tetanus immunity status was considered, i. e. the age of the subjects, the time at which boostering was given, the serotherapy (when it was administered) and the contact with machine lubricating and cooling fluids. Clostridium tetani bacilli and spores were frequently found in aqueous machine fluids. Their presence is a potential hazard for non-vaccinated mechanics coming to contact with the fluids. Tetanus antibody levels in the sera of the tested population were determined in vivo by the toxin neutralization test. The influence on tetanus immunity of the different parameters considered in this paper was subjected to statistical analysis. From the whole population, 27% of the individuals were found to have no protection against tetanus. When age was taken into account, 53% of the individuals over 45 years old and 10% of those under 45 years old were shown to be devoid of tetanus immunity. It could be shown that younger individuals were better protected than older ones, because the formers had been immunized with adsorbed tetanus toxoid and most of the latters with fluid toxoid. Of the individuals in the third group who had received a booster injection within 15 years after primo-vaccination, 98% showed protective tetanus antibody levels in their sera in contrast to 25% when boostering had occurred more than 15 years after primo-vaccination. Contact with machine fluids was found to influence the degree of immunity of only those individuals whose boostering dated back to more than 25 years. Unexpectedly, 3 mechanics seemed to develop immunity after coming into contact with machine fluids. From the results reported here, it is concluded that tetanus immunity in vaccinated individuals should be renewed by a compulsory booster injection given every 5, 10 or, at the minimum, 15 years. Moreover, high-risk populations such as that represented by the mechanics should be immunized or boostered on commencing employment.

Adult↗

PubMed1977

Population data on two new HLA-D determinants, EI and RE.

Homozygous typing cells (HTC) for two new HLA-D determinants, EI and RE, defined by family studies, are described. The HLA-D typing experiments among more than 300 unrelated individuals showed phenotype frequencies of 0.045 for EI and 0.098 for RE. Since the tested population was also typed for its HLA-A and -B alleles, linkage disequilibrium parameters could be calculated: HLA-D type EI was statistically significantly associated with HLA-B13 and Bw17, HLA-D type RE with HLA-Bw40. These data support the working hypothesis that both EI and RE are new alleles of the HLA-D series.

Alleles↗

PubMed1978

The alcohol dehydrogenase polymorphism in populations of Drosophila melanogaster. I. Selection in different environments.

The allozyme polymorphism at the alcohol dehydrogenase locus in Drosophila melanogaster was studied in order to obtain experimental evidence about the maintenance of this polymorphism. Populations started with different initial allele frequencies from homozygous F and S lines showed a convergence of frequencies on regular food at 25 degrees, leading to values equal to those in the base populations. These results were interpreted as due to some kind of balancing selection. In populations kept at 29.8 degrees, a lower equilibrium F frequency was attained. Addition of ethanol and some other alcohols to the food gave a rapid increase in F frequency, and high humidity decreased the F frequency slightly. Combination or alternation of ethanol and high humidity had variable effects in the populations tested. For a further analysis of the allele-frequency changes, estimates were obtained for egg-to-adult survival under different conditions and for adult survival on ethanol-supplemented food. On ethanol food (both at regular and high humidity), egg-to-adult survival of SS homozygotes was considerably lower than that of the FF and FS genotypes. Under regular conditions of food, temperature and humidity, a tendency to heterozygote superiority was observed, while at high humidity a relative high survival of SS was noticed in some tests. Adult survival of SS was lower than that of FF, but FS was generally intermediate, though the degree of dominance differed between populations. The results are consistent with the hypothesis of the occurrence of selection at the Adh locus.

Alcohol Oxidoreductases↗

PubMed2026

Multicancer Detection Tests for Population-Wide Screening of Asymptomatic Individuals: A Systematic Review.

PURPOSE: Multicancer detection (MCD) tests aim to detect different cancer types using a single test. However, evidence on their potential for screening asymptomatic populations remains limited. We consolidated evidence from prospective cohort studies evaluating blood-based MCD tests in primarily asymptomatic adults to contextualize upcoming randomized controlled trial results. MATERIALS AND METHODS: We updated and extended a prior review (to September 2023), conducting comprehensive Medline/Embase searches to February 1, 2026. Key outcomes included cancers detected and not detected by MCD tests, false-positive MCD tests, and diagnostic investigation pathways. Risk of bias (RoB) was assessed using a modified Quality Assessment of Diagnostic Accuracy Studies-2 tool. RESULTS: From 2,723 screened records (244 previously shortlisted to 2023, 2,479 records for 2023-2026), we included 18 articles (12 studies, nine MCD tests); of these, 11 articles had not appeared in prior reviews. Cancer detection rates varied widely between studies, for example, new MCD-test-detected invasive cancers diagnosed ≤12 months post-test ranging from 18.8 (95% CI, 11.0 to 30.1) to 43.8 (95% CI, 29.4 to 62.8) per 10,000 tested, with MCD-test-detected invasive stage I to II cancers ranging from 9.0 (95% CI, 4.2 to 17.2) to 21.0 (95% CI, 11.6 to 35.5) per 10,000 tested. False-positives exceeded MCD-test-detected cancers (eg, approximately 1.6-fold in PATHFINDER, 1.5-fold K-DETEK, 4.2-fold DETECT-A, 8.1-fold SeekInCare studies). Diagnostic investigation pathways were prespecified/suggested in four of eight interventional studies. Where reported, the median time to diagnostic resolution varied from <0.1 months to 4 months for MCD-test-detected cancers, with substantially higher 75th percentiles (3.1-7 months), and similar patterns were observed for false-positive MCD tests. No study was judged to have overall low RoB. CONCLUSION: Substantial heterogeneity in cancer yield metrics likely reflects differences in MCD technologies, diagnostic pathways, follow-up duration, and background standard-of-care screening. Long-term follow-up, randomized trials, fully-paired test comparisons, and implementation research are essential to determine the potential of MCD tests for population screening.

Journal Article↗

PubMed1978

[Seroepidemiological investigations in domestic ruminants from Egypt, Somalia and Jordan for the demonstration of complement fixing antibodies against Rickettsia and Chlamydia (author's transl)].

1450 random serum samples of domestic ruminants from Egypt, Somalia and Jordan were investigated for complement fixing antibodies against Rickettsia and Chlamydia. Between 1.5 and 3.4% of the samples from the animals investigated had antibodies against the RMSF-group of Rickettsia, with exception of the sera from Somalian cattle and sheep from Jordan. Antibodies against Rickettsia of the Typhus-group were found in 4 cattle and 1 goat from Jordan and 2 sheep from Egypt; by agglutination test with type-specific antigen they were identified as antibodies against R. typhi. Using 2 different antigens, antibodies against Coxiella burnetii were found in every population tested. The prevalence was 2.0 to 12.2%, with the exception of cattle in Somalia, where only 1 positive serum (0.2%) was found. 27% of the serum samples from Jordan and 22% from Egypt but none of the 802 samples from Somalia had antibodies against Chlamydia. The results are discussed under an epidemiological point of view.

Animals↗

PubMedDate not supplied

Observations on morning and afternoon glucose tolerance: differences between sexes.

One hundred non-obese and non-diabetic individuals, 50 men and 50 women, were submitted to oral glucose tolerance tests performed in the morning and in the afternoon on different days. Although great individual variations were noted in both sexes, in men the mean blood sugar (BS) values did not significantly differ between the two tests; in women, however, the mean values after glucose loading were significantly higher during the afternoon test. By dividing the test population into those aged 50 and below and those over 50 it was found that only the group of younger women showed significant differences between the two tests with higher mean BS values during the afternoon test.

Adolescent↗

PubMedDate not supplied

Exposure to dust-borne bacteria in agriculture. II. Immunological survey.

In order to investigate whether high exposure to Erwinia herbicola causes sensitization in grain handlers, immunological tests (agargel precipitation, complement fixation, passive cutaneous anaphylaxis, and intradermal) with the extracts of these bacteria were performed in different groups of grain workers and in other groups of population. Tests with extracts of grain dust and other microorganisms were also performed. Grain workers showed in all the tests high incidence of positive reactions to E. herbicola, being significantly higher, as compared with unexposed subjects. Different actinomycetal and fungal extracts gave lower percentages of positive reactions. Skin reactions to E. herbicola were significantly correlated with the reactions to grain dust and showed a close relationship with the degree of exposure. The grain workers with respiratory symptoms reacted more frequently to E. herbicola than asymptomatic ones, both in intradermal and precipitation tests. Thus, these bacteria should be considered as a factor increasing risk of the respiratory disorders among grain handlers.

Agricultural Workers' Diseases↗

PubMed1977

Production and origin of oral malodor: a review of mechanisms and methods of analysis.

Organoleptic studies indicate that the oral cavity is usually the principal source of physiologic malodor associated with the early morning halitosis. In all individuals, regardless of the age or health status of the oral tissues, the most intense oral malodor is exhibited after prolonged periods of reduced saliva flow and abstinence from food and liquid. This results from normal metabolic activity in the oral cavity and is accentuated in cases with periodontal involvement. Physiologic oral malodor is transient in duration as it can be controlled to varying degrees in most individuals by oral hygiene measures, such as tooth brushing, dental prophylaxis, tongue scraping and rinsing with antiseptic mouth washes. Experimental evidence strongly suggests that putrefaction of sulphur-containing proteinaceous substrates by predominantly gram-negative oral microorganisms is the primary cause of oral malodor. Optimum putrefactive activity occurs in low carbohydrate environment, physiological pH, and anaerobic conditions. Salivary sediment containing the exfoliated epithelial cells is the primary source of substrate which exists in a disulphide state. Proteolysis and reduction of disulphide bonds precedes the formation of odor. The odor intensity of putrescent saliva and plaque head-space vapor has been correlated with the concentration of volatile sulphur compounds consisting of hydrogen sulphide, methyl mercaptan, dimethyl sulphide and dimethyl disulphide. Except for dimethyl disulphide, the same sulphur-containing compounds have been found in mouth air of all tested individuals. Hydrogen sulphide and methyl mercaptan emanate an offensive putrid odor and account for approxiamtely 90% of the total sulphur content of mouth air. In half of the population tested, methyl mercaptan and hydrogen sulphide content of early morning mouth air is sufficiently high to account for the oral malodor. Brushing studies indicate that both plaque and tongue are important sources of malodor with most of the odor emanating from the dorso-posterior surface of the tongue. None of the gas chromatographic or mass spectrometric analyses have detected the presence of amines, indole, or skatole in the head-space, mouth air, or breath vapor samples.

Amino Acids↗

PubMed1976

[Use of the neutralization test for mass population studies].

The authors applied the antibody neutralization test (ANT) for detection of causative agent of intestinal infections in feces of healthy population in Turkmenia. Some part of the material was studied in parallel with the aid of the ANT and by the bacteriological method. As a result of comparison it appeared that in using the ANT causative agents of intestinal infections were revealed much more frequently than by the bacteriological method; in this connection this serological method can be recommended as an auxiliary one for the diagnosis of intestinal infections.

Diagnosis, Differential↗