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PubMed1977

The course of Hymenolepis nana infections in thymus-deficient mice.

The kinetics of infection with Hymenolepis nana was examined in normal thymus-deficient mice. Following inoculation with 5 cyticercoids, the number of adult lumen-dwelling H. nana in congenitally thymus-deficient (nude) mice ultimately was at least 75 times the maximum infection intensity of normal thymus-bearing mice or thymus-reconstituted nude mice. Similar results were obtained following inoculation of H. nana eggs into nude mice; although thymus-bearing mice eliminated their infections, nude mice harbored more than 1,000 adult worms throughout the 7 weeks of the experiments. These data show that in mice, immunity is not generated against H. nana in the absence of thymus function. The data also confirm and establish the requirement of cysticercoid development in the intestinal mucosa for stimulation of a protective immune response against H. nana.

Animals↗
PubMed1979

Amphetamine addiction and pregnancy. Psycho-social and medical aspects.

The psycho-social backgrounds of 69 amphetamine-addicted mothers were investigated in order to find indicators which might be applicable in predicting the addicted women's chances of adaptation to motherhood. Of these 69 women, 17 stopped taking drugs in the first months of gestation when they realized that they were pregnant (Group 1). The remaining 52 women continued taking drugs throughout pregnancy (Group 2). There was no difference between the groups as to number of years of addiction, or other drugs used except that more women in Group 2 abused alcohol at the same time. A large proportion of the women in both Groups 1 and 2 were, as children, known to the local social welfare agencies because of their unsatisfactory home conditions. In Group 2, psychiatric illness and drug abuse were more common among parents and siblings than in Group 1. In spite of this, the women in Group 2 had, on the average, been placed in a foster home at a significantly older age. Significantly more women in Group 2 also had a poorer educational background and a criminal record including more serious crimes. At the time of their current pregnancy the women in Group 1 had a more stable social situation with regard to permanent dwelling, work and relationship with non-addicted friends.

Adolescent↗
PubMed1978

Bacterial contamination of pulmonary artery catheters.

The catheter tips of 152 patients, who were haemodynamically supervised by pulmonary artery monitoring or continuous cardiac output determination, were bacteriologically examined. 106 cultures remained sterile, 21 cultures revealed a growth of non pathogenic organisms. Staphylococcus aureus was cultured 15 times, pseudomonas aeruginosa 4 times, Citrobacter as well as Escherichia coli twice, and Klebsiella and Enterobacter once each. There was no statistically significant connection between dwelling period and contamination. Also diabetes mellitus or corticoid medication in high dosage had no significant influence on contamination rate.

Bacteria↗
PubMed1978

Transmissible virus dementia. I. An unusual space and time clustering of Creutzfeldt-Jakob disease and of other organic presenile dementia cases.

A peculiar grouping of Creutzfeldt-Jacob disease (CJD) and of other organic presenile dementia (OPD) cases in a small, prevalently rural area in Czechoslovakia to the east of 19 degrees 35' E and to the north of 48 degrees 15' N was studied. Between August, 1972 and November, 1976, three histologically proven CJD cases, bearing no sporadic of familial patterns, were observed. The distance between their dwellings was 13--17 km. In addition, seven cases of OPD were detected in the same area, two of them being suspected as possible CJD according to clinical evidence.

Adult↗
PubMed1977

Brain cholinesterase activities of birds from forests sprayed with trichlorfon (Dylox) and carbaryl (Sevin-4-oil).

Brain cholinesterase activities were determined in birds from forests sprayed with Dylox(2) at 1.13 kg/hectare (1 lb/acre - active ingredient [a.i.]) or Sevin-4-oil(2) at 1.13 kg/hectare (1 lb/acre - a.i.) for up to 5 days postspray. Of ten bird species evaluated from the Dylox spray area, four species represented by six individuals had values which were depressed more than 2 standard deviations below the mean. Three of these activities (two species) were about 20% less than the mean. Of 12 species evaluated from the Sevin-4-oil spraying, three individuals representing three species had depressed values. One value was depressed greater than 20% below the mean. Half of the depressed activities were in canopy-dwelling birds collected on the day of spray.

Animals↗
PubMed1978

The conflicting role of parasitic infections in modulating the prevalence of asthma.

Nothwithstanding difficulties associated with the limitations of survey techniques and methodology employed to define asthma, the evidence accumulated to date suggests that the reported differences in the prevalence rates of this disease from country to country and within local populations of the one country are real. It is accepted that allergy is not the sole cause of asthma but nonetheless hypersensitivity to environmental allergens is a significant triggering factor in most countries of the world. Comparisons between countries might therefore be influenced by the time of the year when the survey is taken since the prevalence of seasonal asthma would be higher in the period of pollinosis. Environmental factors, and in particular the relative atmospheric concentrations of pollens and the density of house dust mite (D. pteronyssinus and D. farinae) in dwellings, must therefore be considered when accumulating prevalence data. The prevalence rate for childhood asthma is high in Australia, United Kingdom, United States of America and New Zealand, and medium to low in the Scandinavian countries and Switzerland. It is not clear what factors contribute toward these differences since several studies indicate that racial characteristics per se are not pre-eminent in defining susceptibility to asthma. Most surveys indicate that the prevalence of childhood asthma is low to very low among low-income populations living in tropical areas. While it is possible to implicate inadequate diagnosis, genetic factors, nutritional status and allergen exposure as factors contributing towards the low prevalence, it has become fashionable to attribute this observation to the influence of certain helminthic infections. Parasites stimulate the production of high levels of serum IgE, the bulk of which has as yet an undetermined specificity. The suggestion that this IgE blocks mast cell receptors leaving insufficient sites available for sensitization by allergen-specific IgE antibody is attractive. However, since the kinetics of binding to mast cell receptors is unlikely to be the same for all IgE molecules, irrespective of their specificity, this hypothesis appears to be an oversimplification of the problem. It is more likely that parasitic infections repress the synthesis of IgE antibody to environmental allergens, although the mechanism for this is unclear. Circumstantial evidence suggests that the time course of exposure to parasites versus sensitization by environmental allergens may be critical. Another possibility is that parasitic infections in some way nullify the effect of allergens at the level of the target organ, perhaps through the modulating role of eosinophils. If it is established that parasitic infections, particularly in early childhood, suppress the capacity of potentially atopic children to develop asthma and other allergic disorders, there would be some justification in attempting to circumvent allergic disorders in susceptible individuals by a harmless preparation of parasite antigens.

Adolescent↗
PubMed1977

Variola minor in Braganca Paulista county, 1956: a trend-surface analysis.

Trend-surface analysis (TSA), a form of polynomial regression used in geology, ecology and geography, was applied to analysis of the spread of an epidemic of variola minor in a small Brazilian city. Cubic surfaces gave a generalized map of the space-time distribution of the epidemic, allowing those parts of the city to be identified where variola minor was spreading rapidly or slowly. The epidemic spread relatively quickly over the core area of the city, especially to the peripherally located household dwellings in a northeast to south-west direction. The dwellings of adults and pre-school children introducing the disease into their households broadly followed the overall pattern. School child introductory cases from a southern-located school yielded a saddle-shaped contour pattern, centered about the school; but this pattern was not repeated for the school serving the northern half of the city, which showed a ridge-shaped pattern dipping toward the west. Cubic surfaces for the influence of certain household and individual characteristics were investigated, but showed only week trends. The nearest match to the bowl-shaped overall pattern of introductory dates was provided by the vaccination level of the households. From this application, it appears that TSA permits the identification of regional trends in an objective manner and gives a quantitative measure of the importance of these regional trends in terms of the overall variation in the spatial pattern.

Adult↗
PubMed1979

Histoplasmosis in South Carolina: support for the microfocus concept.

An outbreak of anthropurgic histoplasmosis occurred in rural South Carolina when a canebrake which served as a blackbird roost was cleared with a bulldozer. Seven days later the index patient became ill with histoplasmosis. Nine other patients contracted the disease, but only the index case was fatal. Serologic studies on the 10 patients demonstrated high titers in the histoplasmin latex agglutination test within two to three weeks after exposure. Serologic titers to the yeast-form Histoplasma capsulatum antigen in the complement fixation test appeared most frequently, but these antibodies were not diagnostic because complement-fixing antibodies to Blastomyces dermatitidis appeared at the same time. Soil studies demonstrated that viable particles of H. capsulatum persisted at declining levels over a nine-year period. A skin test survey showed that 27.3% of eighth grade students who resided within a 20 km radius of the contaminated site and who were lifelong residents of the same dwelling had a positive histoplasmin skin test.

Adolescent↗
PubMed1977

Isoproterenol enhancement of peritoneal permeability.

As peritoneal dialysis is inefficient enouth to be time-consuming and sometimes clinically ineffective, we have evaluated pharmacologic enhancement of peritoneal permeability. Peritoneal dialyses were performed in New Zealand white rabbits by instillation of 50 ml/Kg of isotonic dialysis solution of standard composition. Mean peritoneal clearance of creatinine was 0.60 ml/Kg/min and urea was 0.80 ml/Kg/min, each decreasing as intraperitoneal dwell was prolonged (by .011 ml/Kg/min or less). With 0.04 micrometer/Kg of isoproterenol administered intraperitoneally, clearances increased to 0.91 and 1.30 ml/Kg/min (p less than 0.01). When isoproterenol was added to the dialysis solution one hour or more before instillation, the increment in clearances was less. Instillation of dialysis solution 24 hours after addition of a higher dose of isoproterenol (0.2 micrometer/Kg) did not increase clearances above control. No effect of isoproterenol on bulk flow of water, associated with the osmotic effect of dextrose, was demonstrated. As peritoneal clearances increased, the ratio creatinine clearance: urea clearance did not decrease, consistent with increased peritoneal permeability as well as blood flow.

Animals↗
PubMed1979

[Morphological and histochemical changes in rabbits living for various times in the vicinity of cement factories in the villages of Beli Izvor and Zlatna Panega].

Results are reported of morphologic and histochemical studies on 60 rabbits, exposed for scattered times to the noxious effects of neighbouring cement works (gr.I - more than one year, gr.II - up to one year, and gr.III - up to 6 months - progeny of gr.I). Experiment No 1 was carried out near the village of Beli Izvor, experiment No 2 - near the village of Zlatna Panega. The results were compared with those obtained in a group of 10 normal control animals at the breeding station in Russe. The degree of morphologic changes in the organs was in direct proportion to the duration of exposure. Comparative assessment of the morphologic findings in rabbits dwelling near Beli Izvor and near Zlatna Panega showed a milder degree of organ damage in rabbits of experiment No 2 (cement works near Zlatna Penga). Inhibition of the T - and B-zones in the lymph follicles of the spleen was observed, indicating injury to the lymph (immunogenic) tissues, which are essential for the normal existence of these animals.

Air Pollutants↗
PubMedDate not supplied

Blood lead levels in San Diego policemen.

Blood lead levels were measured by atomic absorption spectrophotometry in 86 San Diego policemen to see if they would reflect the known high atmospheric lead levels in San Diego. The mean blood lead for the entire group was 27.0 microgram per dl, a level very similar to that found in the general population of other cities. Work exposure to heavy traffic, area of residence, work shift and smoking did not significantly influence blood lead. Thus, an ambient atmospheric lead load ranging from 2 to 5 microgram per cubic m does not demonstrably cause higher blood lead levels in persons exposed to such air. Surprisingly, the youngest group, 21 to 25 years, had the highest mean (32.2 microgram per dl) while the oldest, 46 to 55 years, had the lowest mean (20.9 microgram per dl), a difference statistically highly significant. However, length of work as a policeman per se did not influence blood lead levels. Exposure to other known high-risk factors (hobbies, ceramics, old dwellings) was associated with higher levels (mean 30.6 microgram per dl).

Adult↗
PubMed1978

Distribution and density of mosquitoes in two endemic areas for bancroftian filariasis in Sorsogon, Philippines.

Mosquito density in Rangas where abaca is in abundance is much higher, almost twice, than that of Putiao where abaca is absent. The adult density of Aedes poecilus over Aedes ananae in the two areas combined is 3 to 4 times whereas the larval density of the former is much lower than Aedes ananae. The banana axils is a favorite breeding place for Aedes poecilus but may also utilize the abaca axils. This finding is very favorable in the transmission of bancroftian filariasis because this species of banana is planted around houses even closer to human dwelling than the abaca plants. Aedes poecilus being more anthropophylic than zoophylic can be domesticated as Culex quinquefasciatus and Aedes aegypti which again is a factor in favor of ideal transmission of the disease. The fact that bananas are planted around houses both in villages and towns, transmission of the disease could easily occur in both places, which should be borne in mind when planning a control program. The number of dissected mosquitoes is too small to be of significance in vector determination.

Animals↗
PubMed2025

Ancient climate changes and relaxed selection shape cave colonization in North American cavefishes.

Extreme environments serve as natural laboratories for studying evolutionary processes, with caves offering replicated instances of independent colonizations. The timing, mode and genetic underpinnings underlying cave-obligate organismal evolution remain enigmatic. We integrate phylogenomics, fossils, palaeoclimatic modelling and newly sequenced genomes to elucidate the evolutionary history and adaptive processes of cave colonization in the study group, the North American Amblyopsidae fishes. Amblyopsid fishes present a unique system for investigating cave evolution, encompassing surface, facultative cave-dwelling and cave-obligate (troglomorphic) species. Using 1105 exon markers and total-evidence dating, we reconstructed a robust phylogeny that supports the nested position of eyed, facultative cave-dwelling species within blind cavefishes. We identified three independent cave colonizations, dated to the Early Miocene (18.5 Ma), Late Miocene (10.0 Ma) and Pliocene (3.0 Ma). Evolutionary model testing supported a climate-relict hypothesis, suggesting that global cooling trends since the Early-Middle Eocene may have influenced cave colonization. Comparative genomic analyses of 487 candidate genes revealed both relaxed and intensified selection on troglomorphy-related loci. We found more loci under relaxed selection, supporting neutral mutation as a significant mechanism in cave-obligate evolution. Our findings provide empirical support for climate-driven cave colonization and offer insights into the complex interplay of selective pressures in extreme environments.

Animals↗
PubMed1978

Unusual sex hormone patterns among desert-dwelling hunter-gatherers.

Endocrine parameters were assayed in a San ("Bushman") population of Botswana in an attempt to correlate hormonal secretion and body morphology. Serum levels of gonadotrophins and gonadal steroids were measured by employing radioimmune methods. No evidence for elevated estrogens could be found and males showed endocrine levels comparable with European and South African Negro values. Females have suppressed circulating levels of gonadal steroids and little corpus luteum function. A mechanism by which the ovaries may be suppressed, thereby limiting conception to times of high nutrition, may exist in the San. This hypothesis may have a bearing on the observation that births reach peak levels during March and April.

Adult↗
PubMed2026

Evidence of genome-wide relaxed selection on mildly deleterious mutations in an ancient subterranean catfish.

About one hundred subterranean catfish species have been described, resulting from repeated colonization of cave environments by multiple surface lineages. Most cave-dwelling species are found in the Americas, in particular in South America, but a few species also live in Central and North America. Despite the availability of high-quality genome assemblies for two cave species, the Mexican blind catfish Prietella phreatophila and the Colombian blind catfish Trichomycterus rosablanca, genomic approaches to investigate genetic changes associated with subterranean life or to estimate cave colonization times remain largely unexplored. To fill this gap, we additionally sequenced the genomes of four blind and depigmented subterranean catfishes from Peru (three Trichomycterus and one Astroblepus), as well as the genomes of four close surface relatives. We first extracted a large set of light-related genes, such as phototransduction and crystallin genes, and found contrasting decays of these sequences in different cave species, from 1% of pseudogenes in T. rosablanca to 48% in P. phreatophila. Two independent molecular dating methods gave congruent ages, indicating that these catfishes colonized subterranean habitats at different times, ranging from Early Pliocene to Late Pleistocene, supporting the hypothesis that surface catfishes repeatedly and rapidly adapted to subterranean habitats. The oldest cave species, P. phreatophila, appears to have been thriving in the dark for over 3.5 million years. Moreover, a genome-wide analysis of protein-coding genes suggests weaker purifying selection on mildly deleterious mutations in this cavefish than in other catfish lineages, likely reflecting a long-term small effective population size.

cavefishes↗
PubMed2026

Genome-wide identification and expression profiling of CSP and OBP genes in Stictocephala bisonia reveals candidate genes potentially associated with insecticide response.

Stictocephala bisonia is an important invasive agricultural pest. Due to the frequent application of insecticides in its habitat, this species is under intense selection pressure. Chemosensory proteins (CSPs) and odorant-binding proteins (OBPs) are known to play key roles in insecticide resistance, but their specific functions in S. bisonia remain unclear. In this study, we identified a total of 22 SbisCSPs and 16 SbisOBPs based on the S. bisonia genome. To screen for candidate genes potentially linked to insecticide resistance, we adopted a multi-criteria screening strategy that integrated phylogenetic analysis, molecular docking with three insecticides, and tissue-specific expression profiling. Phylogenetic analysis identified several SbisCSPs and SbisOBPs clustering with genes known to be involved in insecticide resistance, serving as an initial evolutionary filter. Molecular docking results indicated that λ-Cyhalothrin exhibited the strong predicted binding affinity with most of SbisCSPs and SbisOBPs. Subsequent qPCR validation of seven prioritized candidates revealed distinct expression patterns: SbisCSP22 was highly expressed in adults and demonstrated strong binding affinity to all three insecticides tested, suggesting a potential role in mediating multi-insecticide response. Conversely, SbisCSP17 was significantly upregulated in larvae, clustered with genes known to mediate imidacloprid resistance, and exhibited strong binding affinity to imidacloprid. Given its larval-specific expression and the soil-dwelling behavior of larvae, we hypothesize that SbisCSP17 is a key candidate gene for larvae coping with soil-treated insecticides.

Animals↗
PubMedDate not supplied

Contour mapping of the temporal-spatial progression of a contagious disease.

A methodology for contour-map study of contagious-disease epidemics is presented. Its application is exemplified in a smallpox epidemic occurring in a small Brazilian town. Computer-controlled contour-mapping of dates of introduction of variola minor into 169 households and the coordinates of the affected dwellings did not show a single contour pattern, but a group of subareal patterns of within-household outbreaks. Introduction by adults and pre-school children were distributed throughout the whole city area. However, introduction by school children formed two groups of contours and of affected dwellings. Each group was included in a discrete area corresponding to the zone of pupil recruitment of the two schools enrolling 91% of the school-child introductory-cases. The latter were responsible for introduction of the disease into 45% of the city's affected households. Altogether, both zones practically covered the whole city area. In either zone, several patterns surrounded the corresponding school. Even though no time value was entered for any school, contour maps clearly evidenced the influence of those two schools on spread of the epidemic. An estimated rate of linear spread of variola minor was 1.35 m per day in a city subarea.

Adolescent↗
PubMedDate not supplied

[Prisons following reform. Current status and prospects].

The Author has examined the period successive to July 1975, namely, from the approval of the new prison System to the present day, highlighting the manifold negative aspects due to the incomplete application of the reform and not neglecting to review also the positive aspects of the regulations applied. The Author laid special stress on the distorted interpretations given to some different regulations of the System and on the ensuing wrong procedure that has been established, whose correction represents the only way not only towards a proper application of the reforming law, but also for preventing the most serious risk the reform is liable to run; that of being made the object of revisions and abrogations that might ultimately change their nature and jeopardise their objectives. The Author reviews the practical consequences of both the erroneous interpretations of the law and of its misapplications, dwelling on Article 30 in the first place, which has prompted some to define the law the "reform of leaves". Also examined was the problem of the special prisons, the usefulness of which is confirmed by the Author, who upholds the view that they must function in full observance of the regulations, for reasons of equity and opportuneness. From the rehabilitation treatment angle, the prison work, the participation of the extramural community, the "leasure time", the assistance after release. Still in the framework of his critical approach as to the prison reality, the Author illustrates the situation of the health service, and reviews the positive points that have been achieved in the implementation of some reform institutions, with special regard to the new disciplinary approach and its satisfactory results that have already been statistically observed. More adequate talks and correspondence by letter or through the telephone, a better compensation for the prison work, the convict representation in some sectors of intramural life, the measures as an alternative to enprisonment, all these actions represent the practical results of the reform achieved so far in a rather satisfactory way. After dealing with the figure of the surveillance judge, of the director and of the military personnel of prisons, setting forth observations and proposals to enhance their work, the Author declares, by way of conclusion, that he is fully convinced that the reform will ultimately attain its important targets, laying stress on the fact that the good will and the contribution of all those who are called upon to participate in its realization, may prove instrumental in shortening the period of time required for making the reform fully operative.

Criminal Law↗