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At least 19 recordsLinked to original sources
PubMedDate not supplied

Hemispheric prevalence changes in partial epileptic patients on perceptual and attentional tasks.

In relation to the general issue of the long-term effects of epileptic activity on the higher nervous functions, monohemispheric epileptic patients--divided into "lesional" [i.e., with computed tomography (CT) scan-visible lesions] and "nonlesional" (i.e., with CT scan-nonvisible lesions)--were submitted to dichotic verbal and tonal tasks, dichoptic verbal and spatial tasks, and a visual tachistoscopic attentional task. The aim was to investigate whether the typical patterns of hemispheric prevalence, which were observed in normal subjects by using these tests, undergo significant changes in epileptic patients. The findings versus normal subjects seem to demonstrate that (a) in lesional epileptic patients, the prevalence of the hemisphere without macroscopic lesions is a constant rule, whether or not this hemisphere is prevalent in normal subjects; (b) in nonlesional epileptic patients, the patterns are the following: when the epileptic hemisphere is the one that is prevalent in normal subjects, its prevalence is enhanced, whichever the hemisphere; when the epileptic hemisphere is not the hemisphere prevalent in normal subjects, the left one attracts and maintains prevalence, whereas the right one reduces and variously interferes with contralateral prevalence. It is concluded that, with respect to the functions tested, the nature of the epileptic foci seems to influence markedly the interhemispheric prevalence pattern.

Adult↗
PubMed1981

Comments on "growth of a hypercycle" by King (1981).

The notion of hypercycles has been introduced (Eigen, 1971) in order to characterize a functional entity which integrates information stored in individual self-replicating elements. Commonly, these self-replicating elements compete, like polynucleotides do in test tube experiments (Spiegelman, 1971; Biebricher et al., 1981) or, like species do in nature. A single species is selected eventually together with its most frequent mutants and the less efficient competitors disappear. In order to suppress competition, specific coupling terms of second order - these are coupling terms which are proportional to the product of two population numbers or concentration - have to be introduced into the kinetic equations such a link has to extend to all members, requiring the formation of a closed catalytic cycle (Eigen and Schuster, 1979). The copying of polynucleotide sequences, like every transfer of information, can only occur with finite accuracy (Eigen et al., 1981). This physical restriction imposes a limit upon the content of information that can be transmitted. A higher content of information requires more precise replication. A more involved replication machinery, however, presupposes more information to build it. Thus, a single autocatalyst will not be able to increase its content of information over the given threshold. How does one escape from this vicious circle? Hypercycles present a solution to the problem: many information carriers coexist and may cooperate to build a more sophisticated and more precisely copying replication machinery. Optimization of growth rates has never been the goal for which hypercycles were conceived. Any first order process can proceed at a higher rate than a second order process if low enough concentrations are chosen. On the other hand, any realistic hypercycle involves both first and second order terms. At low concentrations first order terms provide for accumulation of material while at higher concentration second order terms stabilize cooperation. At which concentration level such a prevalence changes is a matter of quantitative values of rate parameters rather than of basic principle. An autocatalyst may outgrow a hypercycle under certain conditions but it can never solve the problem of integrating information.

Models, Chemical↗
PubMed1981

Parainfluenza virus infections in the Cirencester Survey: seasonal and other characteristics.

Parainfluenza viruses were isolated 165 times during 14 years surveillance of the illnesses of a general practice population of around 3700. Type 1 isolations numbered 57, type 2 isolations 22 and type 3 isolations 86, representing annual rates of 33, 13 and 50 infections respectively per 10000 of population. Type 4 parainfluenza virus was not isolated. Three major classes of illness gave the following rates: sore throats (Throats) nine, acute febrile respiratory diseases (FRD) 23, acute non-febrile respiratory diseases (non-FRD) 71. The illnesses caused by the three types isolated were similar. Type 1 infections were most abundant in November and type 2 infections in December, and only 11.4% of these types were isolated in the warm semester April through September. Type 3 infections were seasonally bi-modal, with a winter peak in January and an even greater prevalence (66% of the total) in the warm semester. Type 3 infections in the warmer months and in the later years of the Survey were usually more severe. Type 3 virus may therefore be heterogeneous, one subtype possessing and the other lacking the genetic mechanism of "cold-season' prevalence. Geographical discontinuity between summer and winter isolation strengthens the case for the existence of the two subtypes of type 3 parainfluenza virus. Type 3 infections caused the majority of the infections in very young infants. Type 2 infections were widely distributed at all ages. Females were attacked more often than males: type 1, 68.4%; type 2, 63.6%; type 3, 53.5%. Type 3 infections in males outnumbered those in females up to 60 years of age, whereas female predominance became apparent in types 1 and 2 before 10 years of age. All types were widely and sparsely distributed, areas of prevalence changing from year to year. Recurrences occurred only twice, both with type 3 infections. Six persons suffered both a type 1 and a type 3 infection, and one person suffered both a type 2 and a type 3 infection.

Adolescent↗
PubMed1983

Kinetics of homophilic binding by embryonic and adult forms of the neural cell adhesion molecule.

The neural cell adhesion molecule, N-CAM, is a cell surface glycoprotein found on embryonic and adult neurons and on a variety of ectodermal and mesodermal tissues in very early embryos. During development, it shows local variations in prevalence at the cell surface as well as conversion from an embryonic form (E form) with high sialic acid content to an adult form (A form) with lesser amounts of this sugar. This E leads to A conversion occurs on different schedules in different brain regions, and it has been hypothesized that both the conversion and the prevalence changes are related to early regulation of pattern formation and connectivity. In order to identify precisely the consequences of these mechanisms of local cell surface modulation of N-CAM, an assay was developed to measure the rate of aggregation either of vesicles reconstituted from lipid and purified N-CAM or of native brain membrane vesicles. In both preparations, aggregation was greater than 95% inhibitable by specific anti-(N-CAM) Fab' fragments. The rates of aggregation of reconstituted N-CAM vesicles and native brain vesicles were found to be inversely related to the sialic acid content of their N-CAM molecules, with full desialylation resulting in about a 4-fold increase in rate over E-form N-CAM. Intermediate rates were obtained both with A-form N-CAM (which contains only one-third of the sialic acid content of E-form N-CAM) and with partially desialylated E-form N-CAM. The rate of coaggregation of reconstituted vesicles containing E-form N-CAM with reconstituted vesicles containing A-form N-CAM was also intermediate, implying that desialylation did not change the nature of (N-CAM)-(N-CAM) binding but only its rate. Even larger alterations in vesicle aggregation rate were seen when the amount of N-CAM per vesicle was altered. A 2-fold increase in the N-CAM-to-lipid ratio of reconstituted vesicles resulted in a greater than 30-fold increase in their rate of aggregation. Moreover, desialylation did not cause a further increase in the rate of aggregation of these already rapidly aggregating vesicles. These results in a model system demonstrate the large range of binding rates that are obtainable by various forms of local surface modulation of N-CAM. They are consistent with the proposal that similar alterations affecting (N-CAM)-mediated cell adhesion in vivo may be major factors in pattern formation during development of the nervous system.

Age Factors↗
PubMed1980

Viral illness and the postpericardiotomy syndrome. A prospective study in children.

Postoperative fever and pericardial-pleural reaction, designated postpericardiotomy syndrome (PPS), is a common complication of cardiac surgery involving entry into the pericardium. To determine whether the etiology of PPS is viral or immunologic, we undertook a prospective, triple-blind study of consecutive long-term survivors of intrapericardial surgery in the pediatric age group. We evaluated clinical evidence of syndrome and concurrent appearance of antiheart antibody (AHA) by indirect immunofluorescence and antiviral antibody (AVA) by complement fixation in sera preoperatively and serially postoperatively. Incidence of PPS was 27% overall in 400 subjects, but only 3.5% in infants younger than 2 years of age. AHA in high titer appeared in all patients with PPS. A fourfold or greater rise in titer to AVA was found in 70% of these but in only 5% of those with negative AHA and no PPS. AVA rise, tested in 280 consecutive patients, was to no single one of the eight viruses studied (adenovirus, cytomegalovirus, and coxsackievirus B 1-6). Instead, the rise and fall, consistent with antiviral response to a recent infection, was exhibited usually to one but occasionally to two or more viruses, and the viral prevalence changed from year to year, as did that in the community. The study suggests that concurrent fresh or reactivated viral illness plays a role in triggering the immunologic response that characterizes the PPS.

Aging↗
PubMed1991

A longitudinal study of respiratory symptoms in a community population sample. Correlations with smoking, allergen skin-test reactivity, and serum IgE.

Chronic cough and/or phlegm, wheeze in the absence of colds, and rhinitis attributed to allergies are three of the most common respiratory symptoms encountered in community populations. In this study, we have determined the prevalence of these complaints in a random population sample (n = 1,109) using standardized questionnaires at two points in time, eight years apart. Cross-sectional prevalence and changes in symptom occurrence have been correlated with smoking status, allergen skin test reactivity, and total serum IgE levels. Our objective was to determine the individual and combined influence of these three variables on symptom prevalence. Initially, 19.2 percent of the population admitted to wheeze, 17.9 percent to cough, and 44.1 percent to allergic rhinitis. Cough and wheeze prevalence changed little over the eight-year period, while rhinitis increased 11 percent by the second survey. The occurrence of chronic cough was strongly correlated with smoking, and was not further influenced by either allergen skin reactivity or IgE level. Conversely, rhinitis prevalence was related to skin test reactivity with no additional association with smoking or IgE level. The occurrence of wheeze in the absence of colds was associated with both smoking and allergen skin reactivity. Among smokers, the prevalence was over 30 percent and was similar in both skin test positive (STP) and skin test negative (STN) individuals. However, on both surveys, STP ex-smokers and nonsmokers had significantly more wheeze than those who were STN. While the prevalence of wheeze in STN nonsmokers was low (6.8 percent), an IgE-wheeze relationship was also suggested on the second survey. In addition to these cross-sectional symptom relationships, changes in either smoking status or allergen skin reactivity during the study period were associated with changes in the prevalence of each symptom.

Adult↗
PubMed1991

Hepatitis A virus infection in Taipei City in 1989.

To evaluate the current status of hepatitis A virus (HAV) infection, a seroepidemiologic study to detect the prevalence of antibodies against HAV (anti-HAV) has conducted in Taipei City, from March to July, 1989. Serum specimens were collected from 602 male and 503 female apparently healthy children age 12 and under. The prevalence rate of anti-HAV was 27.5% in infants, and decreased to nearly 0% in preschool and early school children up to 10 years old. Compared to a previous study in the same area of Taipei in 1984, our study indicated a further and significant reduction in the prevalence of anti-HAV in almost every age group from 2 to 14 years of age. There was an average of a 5-year prevalence shift. These data suggest that there has been no significant endemic of HAV infection from 1984 to 1989. The antibody prevalence change in the different age groups represents an ongoing trend of HAV seroepidemiology in Taiwan where HAV infection is becoming rare. The age of primary infection in children has been extended to an older age group. The rarity of HAV infection in Taiwan has created a large and growing population of young adults susceptible to hepatitis A virus infection. The effective prevention of hepatitis A virus infection will become a major public health concern.

Child↗
PubMed1991

[Destructive pulmonary tuberculosis in agricultural workers].

Clinical features and efficacy of treatment of destructive pulmonary tuberculosis were investigated in 175 workers of present-day agriculture. In the majority of these cases, tuberculosis was detected during medical consultation. It was characterized by a great extent of specific changes and marked intoxication symptoms. An infiltrative form of the disease was prevalent. Changes in the tracheobronchial tree were revealed during tracheobronchoscopy in 60.3% of the observed patients. For the in-patient period of treatment when conservative therapeutic methods were used, cavity closure was achieved in 31.1% of the newly detected patients and in 5 of 13 remaining cases with recurrent tuberculosis, thus indicating the necessity of a wider and timely application of surgical intervention techniques.

Adolescent↗
PubMedDate not supplied

[Characteristics of the x-ray picture of pulmonary tuberculosis in alcoholics].

Tuberculosis prevalence among alcoholics is high, and pathomorphological and clinical manifestations of the disease are marked. Altogether 84 chronic alcoholics with pulmonary tuberculosis (the 1st group) and 100 tuberculosis non-alcoholic patients (100 controls--the 2nd group) were investigated. X-ray signs of the disease progression, more prevalent changes and more frequent multiple disintegration cavity of larger size are noted in the 1st group. During x-ray investigation of such patients emphasis must be laid on a search for disintegration cavities and bronchogenic dissemination.

Alcoholism↗
PubMedDate not supplied

[State of the hypothalamo-hypophyseo-thyroid system in severe craniocerebral injuries].

The amount of the pituitary thyrotropic hormone and the thyroid hormones (T4, T3, KET) in the serum of 30 patients with severe craniocerebral trauma was studied in dynamics from the 1st and until the 30th day of the disease. Marked disorders in the hypothalamo-hypophyseal-thyroid system were revealed in the form of hypersecretion of the thyrotropic hormone and profound inhibition of the thyroid function. Both the transport-organic and the metabolic phase of metabolism of the thyroid hormones suffer, with prevalent changes in the former. Disturbed thyroid metabolism is an essential link in the pathogenesis of a severe craniocerebral trauma and calls for the corresponding correction.

Brain Injuries↗
PubMed2024

Introducing a hemoglobin G-Makassar variant in HSCs by in vivo base editing treats sickle cell disease in mice.

Precise repair of the pathogenic mutation in hematopoietic stem cells (HSCs) represents an ideal cure for patients with sickle cell disease (SCD). Here, we demonstrate correction of the SCD phenotype by converting the sickle mutation codon (GTG) into a benign G-Makassar variant (GCG) using in vivo base editing in HSCs. We show successful production of helper-dependent adenoviral vectors expressing an all-in-one base editor mapping to the sickle mutation site. In HSC-enriched cells from SCD patients, transduction with the base editing vector in vitro resulted in 35% GTG > GCG conversion and phenotypic improvements in the derived red blood cells. After ex vivo transduction of HSCs from an SCD mouse model and subsequent transplantation, we achieved an average of 88% editing at the target site in transplanted mice. Importantly, in vivo HSC base editing followed by selection generated 24.5% Makassar variant in long-term repopulating HSCs of SCD mice. The treated animals demonstrated correction of disease hallmarks without any noticeable side effects. Off-target analyses at top-scored genomic sites revealed no off-target editing. This in vivo approach requires a single non-integrating vector, only intravenous/subcutaneous injections, and minimal in vivo selection. This technically simple approach holds potential for scalable applications in resource-limiting regions where SCD is prevalent.

Animals↗
PubMed1988

Human immunodeficiency virus infection among employees in an African hospital.

To define the prevalence and course of human immunodeficiency virus (HIV) infection, we examined prospectively a cohort of 2002 adult hospital workers in Kinshasa, Zaire. From 1984 to 1986 the prevalence of HIV infection increased from 6.4 percent to 8.7 percent. Over the two years there was a cumulative incidence of new HIV infection of 3.2 percent. The prevalence was higher among women (16.9 percent) and men (9.3 percent) under the age of 30 than among women (9.0 percent) and men (6.2 percent) over 30. Prevalence rates were similar among physicians (5.6 percent), laboratory workers (2.9 percent), and clerical workers (7.9 percent), but they were higher among female nurses (11.4 percent) and manual workers (11.8 percent). Despite marked differences in the intensity of nosocomial exposure, female nurses had similar infection rates on the female internal medicine ward (9.9 percent), in pediatrics (10.8 percent), and in the delivery room (10.7 percent). The attributable risk of HIV infection from a transfusion was 5.9 percent. Neither medical injections nor scarification was a risk factor for HIV infection. Of the 101 seropositive asymptomatic employees in the 1984 survey, 16 percent had AIDS-related complex, 3 percent had AIDS, and 12 percent had died of AIDS by 1986. Previous studies have revealed a seroprevalence of 8.4 percent among women attending an antenatal clinic near the hospital in 1984 and 1986, and of 5.8 percent (in 1984) and 6.5 percent (in 1986) among men donating blood at the hospital's blood bank. We conclude that there is a continuing high prevalence of HIV infection among hospital workers in Kinshasa, Zaire, which appears to be representative of that in the community and not nosocomial.

AIDS-Related Complex↗
PubMedDate not supplied

Distribution and trends of HIV infection in blood donors of four metropolitan cities.

Screening for HIV infection has been made mandatory for every unit of blood collected for transfusion in major cities of the country, having facilities for such screening. Results of HIV screening among blood donors received from the 4 Metropolitan cities of Delhi, Bombay, Calcutta and Madras have been analysed year wise from 1989 to 1991 to determine the magnitude and trends of HIV infection in different categories of blood donors and the seropositivity rates seems to be increasing over time. Universal coverage of HIV screening for donated blood has not been fully achieved and the justification and urgency for achieving complete coverage is highlighted.

Adult↗
PubMed1992

Rising trend of HIV infection with special reference to blood donors.

This paper describes the experience in testing for antibodies to the human immunodeficiency virus (anti-HIV) at a private institution. A total of 31,003 persons were tested between August 1986 and June 1990 including 20, 321 blood donors. The other 10,712 were visitors to the Ohso International Commune (OIC), a commune for followers of Osho Rajneesh. Another 133 patients, 45 of whom had been repeatedly transfused, were also tested. Thirty two persons tested positive-22 blood donors, 4 visitors to OIC and 6 patients. The seropositivity of unselected blood donors was O of 273 donors in 1986, 1 of 2836 in 1987 (0.04%), 2 of 5373 in 1988 (0.04%), 11 of 7201 in 1989 (0.15%) and 8 of 4640 in the first half of 1990 (0.17%). Since non-professional blood donors represent a sample of the general population, a rise in seropositivity in the former may imply a rise in the latter.

Adult↗
PubMed1989

Human immunodeficiency virus type 1 (HIV-1) infection among female prostitutes in Borno State of Nigeria: one year follow-up.

Serological investigations on female prostitutes resident in Borno State in northeastern Nigeria have shown that the seroprevalence of HIV-1 infection has increased 9.81%--fold in one year. The highest sero-prevalence rates were found amongst prostitutes who had not benefited from previous health education campaigns. Prostitution appears to be on the increase in spite of AIDS probably because of the difficulty in finding alternative means of making a living. Attempts to halt the spread of HIV infection are hampered by the fact that most prostitutes are indifferent to the use of condoms and do not appreciate the importance of protecting themselves from the risks of HIV infection. Their frequent mobility also poses a problem as it makes it difficult for them to benefit from health education campaigns. The prevalence of HIV-1 infection among female prostitutes in Borno State (as indeed in other States in Nigeria) is likely to rise sharply in the next few years unless serious efforts are made to intensify health education campaigns targeted at the high risk groups.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Integrating health services into an MCH-FP program in Matlab, Bangladesh: an analytical update.

This is a follow-up to a 1984 study that analyzed the relationship between areal variation in the contraceptive prevalence time series and in the intensity of maternal and child health (MCH) services of the Matlab Family Planning Health Services Project. Results based on 69 months of observation suggested that the addition of MCH components to a program with basic MCH and comprehensive family planning services had no incremental impact on family planning efficacy. However, basic MCH services, involving clinical back-up to family planning and child care since the beginning of the program in Matlab, may have contributed to clients' faith in the clinic staff and the overall efficacy of the Matlab program. In the 18 months that followed the cut-off date for this analysis, contraceptive prevalence increased markedly in the study areas. The present analysis repeats the earlier one for the extended time series to determine if the intensification of health services in Matlab contributed to this secondary increase in prevalence, and to ascertain whether the MCH service regimes have long-run differential impacts. Results for the 87-month time series are similar to those of the previous analysis, suggesting that the introduction of additional MCH inputs in the Matlab service area over the 1982-83 period had no incremental impact on the contraceptive prevalence rate time trend.

Bangladesh↗