981 resultados para Young learners
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In vitro- and in vivo-assays were conducted, to study the possible role of streptomycin- and actinomycin-producing soil actinomycetes for the pathogenesis of "Cara inchada" in cattle (CI). Adherence of Bacteroides spp. to epithelial cells of the bovine gingiva, known to be associated with the progressive lesions of CI, was significantly increased by the addition of streptomycin, actinomycin or antibiotic culture supernatants of the soil actinomycetes. Applications of these mixtures together with Actinomyces pyogenes to the marginal gingiva of the upper premolar teeth of about 1 month old Holstein Friesian calves did not lead to progressive lesions of CI. Only one calf exhibited a slight diarrhea and a temporary retraction of the gingiva at the site of application.
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The present thesis had two main objectives: The first was to assess how child sexual abuse (CSA) interviews in Finland are conducted through analysing the interviewing techniques applied and the language used by the interviewers, as well as to suggest ways to improve interviews if they were found to have deficiencies. The second main aim was to contribute to the growing research corpus concerning CSA interviews, in particular, by addressing how interviewers follow up information provided by the child, by analysing whether child health care professionals would use childadapted language, and by studying the kind of modifications in the verbal behaviour of interviewers and children that were associated with a) repeated interviews, b) a support person’s presence at the interview, and c) the use of anatomically detailed dolls. Two complementary samples of CSA interviews were analysed. The first one was composed of child interviews with 3-12-year-old children (N = 27) that had been considered problematic by lawyers or other involved professionals (Studies I and IV). The second sample consisted of unselected interviews (N = 43) with children aged 3 to 8 years conducted in a number of hospitals in different parts of the country (Studies II and III). Study I: The verbal interaction between interviewer and child was analysed in a sample of interviews that had been considered to be problematic by involved professionals. Results showed that interviewers used inappropriate questioning techniques, relying on option-posing, specific suggestive and unspecific suggestive questions to a significant extent, these comprising around 50% of all interviewer utterances. The proportion of invitations, which the research community recommends interviewers to rely on, was strikingly low. Invitations and directive utterances were associated with an increase in informative responses by the child in terms of response type, number of new details reported, as well as length of response. The opposite was true for option-posing and suggestive utterances. Longer questions by the interviewer (in number of words) often rendered no reply from the child, whereas shorter questions were followed by descriptive answers. Even after the child had provided an informative answer, interviewers failed to follow up the information in an adequate way and instead continued to rely on focused and leading questions. Study II: Due to the possible bias of the sample analysed in Study I, the most important analyses were rerun with the unselected sample and reported separately. Results were quite similar between the two studies, indicating that the problems observed in Study I, with interviewers relying on option-posing and suggestive questions to a significant extent, are likely to be general and not specific for those interviews. Even if suggestive questions were slightly less and invitations slightly more common in this sample than in the previous study, almost half of the interviewer questions were still optionposing or suggestive, and also in this sample, interviewers failed to follow up information by the child in a facilitating manner. Differentiating between judicial and contextual details showed that while facilitators, invitations, and directive utterances elicited more contextual than judicial details, the opposite was true for specific suggestive utterances. These results might be explained by the reluctance of children to describe sexual details related to the abuse events. Alternatively, they may also be due to children describing incorrect sexual details as a result of suggestive interviewing techniques. Study III: This study examined features of the language used by the interviewers. Interviewer utterances included multiple questions, long statements, complicated grammar and concepts, as well as unclear references to persons and situations. More than a fifth of the interviewer utterances were coded as belonging to at least one of these categories. The results suggest that even professionals who are experienced in interacting with children may have difficulties in using a child-sensitive language, adding to the pool of studies showing similar problems to occur in legal hearings with children conducted by lawyers. As children rarely comment on, or even recognise, their lack of comprehension, the use of a language that is too complex can have detrimental consequences for the outcomes of investigative interviews. Interviewers used different approaches to introduce the topic of abuse. While 15% of the children spontaneously addressed the topic of abuse, probably indicating that they felt confident with the interviewer and the situation, in almost 50% of the cases, the interviewer introduced the topic of abuse in a way that can be considered leading. Interviews were characterised by a lack of structure, apparent in frequent rapid switches of topic by the interviewer. This manner was associated with a decrease in the number of new details provided by the children. Study IV: This study analysed possible changes in the interview dynamics associated with repeated interviewing, the presence of a support person (related to the child), and the use of anatomically detailed (AD) dolls. Repeated interviewing, in combination with suggestive questions, has previously been found to seriously contaminate children’s accounts. In the present material, interviewers used significantly more suggestive utterances in the repeated condition, thus endangering the reliability of the children’s reports. Few studies have investigated the effects of a support person’s presence at the interview. The results of the present study showed that interviewers talked more and children provided less information when a support person was present. Supporting some earlier findings regarding the use of AD dolls, the present results showed that using AD dolls was associated with longer interviewer utterances and shorter, less responsive, and less detailed child responses. Interviewers used up to five times more unspecific suggestive utterances when dolls were used, for instance through repeatedly asking the child to show “what really happened” with the dolls. Conclusion: The results indicate that CSA interviews in Finland are not conducted in a manner that follows best practice as defined by the research community and as stated in a number of guidelines. When comparing these questioning strategies with the recommendations, which have been predominant in the field for more than ten years now, it can be concluded that the interviews analysed were conducted in a manner that undermines the possibility to elicit an uncontaminated and accurate narrative from the children. A particularly worrying finding was the fact that interviewers did not follow up relevant information by the children in an adequate way. A number of clinical implications can be drawn from the results, particularly concerning the need for improvement in the quality of CSA interviews. There is convincing research regarding how to improve CSA interviews, notably through training forensic child interviewers to use a structured interviewing protocol, and providing them with continuous supervision and feedback. Allocating appropriate resources to improve the quality of forensic child interviews is a matter of protecting the rights of all persons involved in CSA investigations, in particular those of the children.
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Background: In the past, oxidized low density lipoprotein (ox-LDL) has been associated with an unbeneficial lipid profile. This atherogenic lipid profile increases the risk of atherosclerotic cardiovascular diseases. Physical fitness has substantial effect on serum lipoprotein concentration as well as body composition and humoral responses, however interrelationships between ox-LDL and physical fitness have not been widely examined in a nationally representative sample. Aims: This thesis evaluates how cardiorespiratory and muscular fitness associate with ox-LDL lipids and how the other known risk factors of atherosclerosis might alter these associations. Subjects and Methods: The study cohort consisted of 846 healthy young males (mean age 25.1, SD 4.6) who were gathered by voluntary nationwide recruitment. Each participant conducted a series of physical fitness tests (cardiorespiratory and muscular fitness) and answered a detailed questionnaire that included lifestyle habits (i.e. smoking and leisuretime physical activity). Venous blood samples including ox-LDL and serum lipids were also collected. Results: Higher levels of ox-LDL were found in overweight and obese men, however, high cardiorespiratory fitness seemed to protect the overweight from high levels of ox-LDL. Young men who smoked and had poor cardiorespiratory or muscular fitness possessed a higher concentration of ox-LDL lipids when compared to comparable levels of cardiorespiratory or muscular fitness non-smoking young men. Metabolic syndrome was associated with increased levels of ox-LDL and high levels of ox-LDL combined with poor cardiorespiratory and abdominal muscle fitness seems to predict metabolic syndrome in young men. Also, participants with poor cardiorespiratory fitness and low levels of testosterone had higher levels of ox-LDL when compared to participants with high cardiorespiratory fitness / low testosterone as well as those with poor cardiorespiratory fitness / high testosterone. Conclusions: Good cardiorespiratory and muscular fitness protects young men from increased levels of ox-LDL lipids. This association was discovered in young men who were categorized as being overweight, smokers, metabolic syndrome or with low levels of testosterone. Being fit seems to prevent higher levels of ox-LDL, even in young healthy
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This study was carried out to investigate the efficiency of several herbicides under field conditions, by post-emergence application onto the entire area, their effect on the control of weeds in young coffee plantations and commercial coffee and bean intercropping system, as well as on both crops. Seedlings of Coffea arabica cv. Red Catuaí with four to six leaf pairs were transplanted to the field and treated according to conventional agronomic practices. A bean and coffee intercropping system was established by sowing three lines of beans in the coffee inter-rows. At the time the herbicides were sprayed, the coffee plants had six to ten leaf pairs; the bean plants, three leaflets; and the weeds were at an early development stage. Fluazifop-p-butyl and clethodim were selective for coffee plants and controlled only Brachiaria plantaginea and Digitaria horizontalis efficiently. Broad-leaved weeds (Amaranthus retroflexus, Bidens pilosa, Coronopus didymus, Emilia sonchifolia, Galinsoga parviflora, Ipomoea grandifolia, Lepidium virginicum, and Raphanus raphanistrum) were controlled with high efficiency by sole applications of fomesafen, flazasulfuron, and oxyfluorfen, except B. pilosa, C. didymus, and R. raphanistrum for oxyfluorfen. Sequential applications in seven-day intervals of fomesafen + fluazifop-p-butyl, or clethodim, and two commercial mixtures of fomesafen + fluazifop-p-butyl simultaneously controlled both types of weed. Cyperus rotundus was only controlled by flazasulfuron. Except for fluazifop-p-butyl and clethodim, all herbicide treatments caused only slight injuries on younger coffee leaves. However, further plant growth was not impaired and coffee plant height and stem diameter were therefore similar in the treatments, as evaluated four months later. Fomesafen, fluazifop-p-butyl, and clethodim, at sole or sequential application, and the commercial mixtures of fomesafen + fluazifop-p-butyl were also highly selective for bean crop; thus at doses recommended for bean crop, these herbicides may be applied to control weeds in coffee and bean intercropping systems by spraying the entire area.
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The effects of competition of seven weed species on the growth of coffee plants were evaluated under greenhouse conditions. Thirty days after coffee seedling transplantation into 12 L pots with soil level area of 6.5 dm², weeds were transplanted into or sown in those pots, at densities of 0, 1, 2, 3, 4 and 5 plants per pot. Competition or weedy periods from weed transplantation or emergence to plant harvesting, at weed pre-flowering stage, were: 77 days - Bidens pilosa, 98 days - Brachiaria decumbens, 180 days - Commelina diffusa, 82 days - Leonurus sibiricus, 68 days - Nicandra physaloides, 148 days - Richardia brasiliensis and 133 days - Sida rhombifolia. Coffee plant height, stem diameter, leaf number and shoot dry matter were determined. Effects of competition by N. physaloides and S. rhombifolia against coffee plants were among the lowest, since only a slight decrease in all the characteristics evaluated in coffee plants was observed. The other weed species caused severe decrease in growth, mainly with increasing weed plant densities. Competition degree was found to depend on weed species and density.
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The purpose of this study was to examine and expand understanding concerning young Finnish registered nurses (RN) with an intention to leave the profession and the related variables, specifically when that intention has emerged before the age of 30. The overall goal of the study was to develop a conceptual model in relation to young RNs’ intention to leave the profession. Suggestions for policymakers, nurse leaders and nurse managers are presented for how to retain more young RNs in the nursing workforce. Suggestions for future nursing research are also provided. Phase I consists of two sequential integrative literature reviews of 75 empirical articles concerning nurses’ intention to leave the profession. In phase II, data had been collected as part of the Nurses’ Early Exit (NEXT) study, using the BQ-12 structured postal questionnaire. A total of 147 young RNs participated in the study. The data were analysed with statistical methods. In phase III, firstly, an in-depth interpretive case study was conducted in order to understand how young RNs explain and make sense of their intention to leave the profession. The data in this study consisted of longitudinal career stories by three young RNs. The data was analysed by using narrative holistic-content and thematic methods. Secondly, a total of 15 young RNs were interviewed in order to explore in-depth their experiences concerning organizational turnover and their intent to leave the profession. The data was analysed using conventional content analysis. Based on earlier research, empirical research on the young RNs intention to leave the profession is scarce. Nurses’ intention to leave the profession has mainly been studied with quantitative descriptive studies, conducted with survey questionnaires. Furthermore, the quality of previous studies varies considerably. Moreover, nurses’ intention to leave the profession seems to be driven by a number of variables. According to the survey study, 26% of young RNs had often considered giving up nursing completely and starting a different kind of job during the course of the previous year. Many different variables were associated with an intention to leave the profession (e.g. personal burnout, job dissatisfaction). According to the in-depth inquiries, poor nursing practice environments and a nursing career as a ‘second-best’ or serendipitous career choice were themes associated with young RNs’ intention to leave the profession. In summary, young RNs intention to leave the profession is a complex phenomenon with multiple associated variables. These findings suggest that policymakers, nurse leaders and nurse managers should enable improvements in nursing practice environments in order to retain more young RNs. These improvements can include, for example, adequate staffing levels, balanced nursing workloads, measures to reduce work-related stress as well as possibilities for advancement and development. Young RNs’ requirements to provide high-quality and ethical nursing care must be recognized in society and health-care organizations. Moreover, sufficient mentoring and orientation programmes should be provided for all graduate RNs. Future research is needed into whether the motive for choosing a nursing career affects the length of the tenure in the profession. Both quantitative and in-depth research is needed for the comprehensive development of nursing-turnover research.
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Trinexapac-ethyl and sulfometuron-methyl are the most widely used ripeners in sugarcane. The application is performed by airborne spraying. Thus, if weather conditions are unfavorable, spray drift to neighboring areas may occur. The objective of this study was to assess the selectivity of the plant growth regulators trinexapac-ethyl and sulfometuron-methyl, used as sugarcane ripeners, to eucalyptus (Eucalyptus urograndis) young plants. The experiment was installed in an eucalyptus commercial yield area, in the municipality of Tambaú, state of São Paulo, Brazil, and arranged in a 2 x 8 factorial design in randomized blocks with four replications. The treatments studied were trinexapac-ethyl and sulfometuron-methyl, sprayed in eight doses, 0; 1.0; 2.5; 5.0; 10; 25; 50 and 100% of the dose used in sugarcane as ripeners (200 g ha-1 of trinexapac-ethyl and 15 g ha-1 of sulfometuron-methyl). Chemical ripeners were applied on eucalyptus plants with 48 cm in height on average; 10.1 branches; 4.5 mm of stem diameter and 44.3 cm of crown diameter, at 46 days after seeding. Trinexapac-ethyl was selective to eucalyptus and stimulated crown diameter growth. At higher doses, sulfometuron-methyl promoted severe noticeable injuries in eucalyptus plants, such as apical bud death. However, during the assessment period the plants recovered and the visual symptoms of phytotoxicity and growth alterations were not observed at 60 days after application. The plant growth regulators trinexapac-ethyl and sulfometuron-methyl were selective to eucalyptus young plants.
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This study looks at negotiation of belonging and understandings of home among a generation of young Kurdish adults who were born in Iraq, Iran, and Turkey and who reached adulthood in Finland. The young Kurds taking part in the study belong to the generation of migrants who moved to Finland in their childhood and early teenage years from the region of Kurdistan and elsewhere in the Middle East, then grew to adulthood in Finland. In theoretical terms, the study draws broadly from three approaches: transnationalism, intersectionality, and narrativity. Transnationalism refers to individuals’ cross-border ties and interaction extending beyond nationstates’ borders. Young people of migrant background, it has been suggested, are raised in a transnational space that entails cross-border contacts, ties, and visits to the societies of departure. How identities and feelings of belonging become formed in relation to the transnational space is approached with an intersectional frame, for examination of individuals’ positionings in terms of their intersecting attributes of gender, age/generation, and ethnicity, among others. Focus on the narrative approach allows untangling how individuals make sense of their place in the social world and how they narrate their belonging in terms of various mechanisms of inclusion and exclusion, including institutional arrangements and discursive categorisation schemes. The empirical data for this qualitative study come from 25 semi-structured thematic interviews that were conducted with 23 young Kurdish adults living in Turku and Helsinki between 2009 and 2011. The interviewees were aged between 19 and 28 years at the time of interviewing. Interview themes involved topics such as school and working life, family relations and language-learning, political activism and citizenship, transnational ties and attachments, belonging and identification, and plans for the future and aspirations. Furthermore, data were collected from observations during political demonstrations and meetings, along with cultural get-togethers. The data were analysed via thematic analysis. The findings from the study suggest that young Kurds express a strong sense of ‘Kurdishness’ that is based partially on knowing the Kurdish language and is informed by a sense of cultural continuity in the diaspora setting. Collective Kurdish identity narratives, particularly related to the consciousness of being a marginalised ‘other’ in the context of the Middle East, are resonant in young interviewees’ narrations of ‘Kurdishness’. Thus, a sense of ‘Kurdishness’ is drawn from lived experiences indexed to a particular politico-historical context of the Kurdish diaspora movements but also from the current situation of Kurdish minorities in the Middle East. On the other hand, young Kurds construct a sense of belonging in terms of the discursive constructions of ‘Finnishness’ and ‘otherness’ in the Finnish context. The racialised boundaries of ‘Finnishness’ are echoed in young Kurds’ narrations and position them as the ‘other’ – namely, the ‘immigrant’, ‘refugee’, or ‘foreigner’ – on the basis of embodied signifiers (specifically, their darker complexions). This study also indicates that young Kurds navigate between gendered expectations and norms at home and outside the home environment. They negotiate their positionings through linguistic repertoires – for instance, through mastery of the Finnish language – and by adjusting their behaviour in light of the context. This suggests that young Kurds adopt various forms of agency to display and enact their belonging in a transnational diaspora space. Young Kurds’ narrations display both territorially-bounded and non-territorially-bounded elements with regard to the relationship between identity and locality. ‘Home’ is located in Finland, and the future and aspirations are planned in relation to it. In contrast, the region of Kurdistan is viewed as ‘homeland’ and as the place of origins and roots, where temporary stays and visits are a possibility. The emotional attachments are forged in relation to the country (Finland) and not so much relative to ‘Finnishness’, which the interviewees considered an exclusionary identity category. Furthermore, identification with one’s immediate place of residence (city) or, in some cases, with a religious identity as ‘Muslim’ provides a more flexible venue for identification than does identifying oneself with the (Finnish) nation.
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Tämän sivuaineen tutkielman tarkoituksena on selvittää, miten suomalaiset ja italialaiset englannin kielen opiskelijat tunnistavat englanninkielisten idiomien merkityksiä. Erityisesti opiskelijoiden oman äidinkielen vaikutusta idiomien ymmärtämiseen tutkitaan, kuin myös idiomien eri ominaisuuksien vaikutusta. Lisäksi tutkitaan, miten opiskelijat itse ajattelevat osaavansa käyttää idiomeja, ja pitävätkö he idiomien oppimista tärkeänä. Tutkielmaan osallistui 35 suomalaista englannin kielen yliopisto-opiskelijaa ja 34 italialaista englannin kielen yliopisto-opiskelijaa. Tutkimusaineisto kerättiin monivalintakyselyn avulla. Idiomit valittiin Collins Cobuild Dictionary of Idioms (2001) -sanakirjasta. Kysely sisälsi 36 idiomia, jotka valittiin kolmesta eri frekvenssiluokasta. Jokaisesta frekvenssiluokasta valittiin neljä idiomia, joille oli vastine sekä suomen että italian kielessä, neljä idiomia, joille oli vastine vain suomen kielessä ja neljä idiomia, joille oli vastine vain italian kielessä. Kullekin idiomille oli annettu neljä merkitysvaihtoehtoa, ja näistä yksi tai kaksi oli sanakirjojen mukaisia oikeita vastauksia. Tutkimuksen tulokset näyttävät osoittavan, että sekä suomalaisilla että italialaisilla oli vaikeuksia idiomien merkitysten tunnistamisessa. Kuitenkin myös suomalaisten ja italiaisten välillä oli tilastollisesti merkittävä ero. Suomalaiset osasivat idiomit huomattavasti paremmin kuin italialaiset. Koehenkilöt ymmärsivät merkittävästi helpommin idiomit joille oli vastine heidän omassa äidinkielessään kuin idiomit joille ei ollut vastinetta. Lisäksi vastaajat näyttivät hyötyvän myös idiomien kuvainnollisen ja kirjaimellisen merkityksen läheisyydestä eli läpinäkyvyydestä. Idiomien frekvenssi sen sijaan ei näyttänyt vaikuttavan niiden ymmärtämiseen. Suomalaisten ja italialaisten englannin opiskelijoiden mukaan idiomien opiskelu on hyödyllistä ja tarpeellista. Tulokset osoittavat, että idiomien ymmärtäminen on haastavaa jopa edistyneille oppijoille. Omalla äidinkielellä näyttää olevan suuri vaikutus idiomien ymmärtämiseen, ja nimenomaan samankaltaisuudesta on hyötyä. Äidinkielen merkitykseen vieraiden kielten oppimisessa ja sanaston oppimisessa täytyisi kiinnittää enemmän huomiota, ja idiomeja sekä muuta kuvainnollista kieltä täytyisi opettaa myös edistyneemmille oppijoille.
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Background: The function of the autonomic nervous system (ANS) can be evaluated with heart rate variability (HRV). Decreased HRV is associated with aging, the male sex, increased heart rate, and overall increased cardiometabolic risk. It has been hypothesized that early atherosclerotic vascular changes and ANS function are related. Aims: The aims were to assess reference values on HRV in young adults, and examine associations with HRV and cardiometabolic risk factors and metabolic syndrome (MetS) and to study relations between HRV and ultrasonographically measured vascular properties. Participants and methods: The present thesis is part of the Cardiovascular Risk in Young Finns Study. The thesis is based on the follow-up study in 2001, when the study individuals were 24-39 years of age. HRV data were available on 1 956 individuals. Results: HRV was inversely associated with age and heart rate (for all p<0.001). Highfrequency HRV (HF) was higher, and low-frequency HRV (LF) lower in women than men (p<0.0001 for both). MetS was associated with 11% decreased HF and 12% increased LF/HF-ratio in women, and 8% decreased HF and 4% increased LF/HF-ratio in men. Carotid artery distensibility was independently associated with HF and total HRV (for both p<0.05). Conclusions: The reference values in young adults were generated. Decreased HRV was associated with age, the male sex and increased heart rate. Women had higher HF and lower LF variability than men. MetS was related to decrease in HRV. The observed associations between carotid elasticity and HRV, supports the hypothesis that reduction in carotid elasticity may lead to decrease in autonomic cardiac control.
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Six brachytic maize varieties were crossed in a diallel mating scheme. Both varieties and crosses were grown hydroponically in a greenhouse, in randomized complete blocks with three replications in two seasons. Four brachytic double cross hybrids were used as checks. Twenty-eight days after planting, data for eight traits were taken for weights of the total plant (TPW), top plant (TOW), total roots (TRW), seminal roots (SRW), and nodal roots (NRW) and number of total roots (TRN), seminal roots (SRN), and nodal roots (NRN). Ten plants were measured in each plot and all the analyses were accomplished with plot means. In the diallel cross the top plant contributed 57.6% of the total plant weight, for seminal roots 15.4%, and for nodal roots 27.0%. Root number distribution was 36.7% seminal roots and 63.3% nodal roots. Approximately the same ratios were observed in the checks. The average heterosis effects were nonsignificant for all traits; the other components of heterosis (variety and specific heterosis) also were not important sources of variation in young plants. The overall results suggest that nonadditive gene action is not an important source of variation for the plant and root system of young plants. The positive correlation coefficients for combinations of traits indicated that they are under the control of a polygenic system
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Type 1 diabetes, as an autoimmune disease, presents several islet cell-specific autoantibodies such as islet cell antibody (ICA), anti-insulin, anti-glutamic acid decarboxylase (GAD) and the antibody (Ab) against tyrosine phosphatase (PTP)-like protein known as ICA-512 (IA-2). In order to determine the frequency of the anti-GAD and anti-IA-2 autoantibodies in Brazilian type 1 diabetes patients we studied 35 diabetes mellitus (DM) type 1 patients with recent-onset disease (£12 months) and 37 type 1 diabetes patients with long-duration diabetes (>12 months) who were compared to 12 children with normal fasting glucose. Anti-GAD65 and anti-IA-2 autoantibodies were detected with commercial immunoprecipitation assays. The frequency of positive results in recent-onset DM type 1 patients was 80.0% for GADAb, 62.9% for IA-2Ab and 82.9% for GADAb and/or IA-2Ab. The long-duration type 1 diabetes subjects presented frequencies of 54.1% for GADAb and IA-2Ab, and 67.5% for GAD and/or IA-2 antibodies. The control group showed no positive cases. Anti-GAD and IA-2 assays showed a high frequency of positivity in these Brazilian type 1 diabetes patients, who presented the same prevalence as a Caucasian population.
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Although a slightly elevated office blood pressure (BP) has been reported in several studies, little is known about the prolonged resting blood pressure, heart rate (HR) and baroreflex sensitivity (BRS) of prehypertensive subjects with a family history of hypertension. Office blood pressure, prolonged resting (1 h) BP and HR were measured in 25 young normotensives with a positive family history of hypertension (FH+) and 25 young normotensives with a negative family history of hypertension (FH-), matched for age, sex, and body mass index. After BP and HR measurements, blood samples were collected for the determination of norepinephrine, plasma renin activity and aldosterone levels, and baroreflex sensitivity was then tested. Casual BP, prolonged resting BP and heart rate were significantly higher in the FH+ group (119.9 ± 11.7/78.5 ± 8.6 mmHg, 137.3 ± 12.3/74.4 ± 7.9 mmHg, 68.5 ± 8.4 bpm) compared to the FH- group (112.9 ± 11.4/71.2 ± 8.3 mmHg, 128.0 ± 11.8/66.5 ± 7.4 mmHg, 62.1 ± 6.0 bpm). Plasma norepinephrine level was significantly higher in the FH+ group (220.1 ± 104.5 pg/ml) than in the FH- group (169.1 ± 63.3 pg/ml). Baroreflex sensitivity to tachycardia (0.7 ± 0.3 vs 1.0 ± 0.5 bpm/mmHg) was depressed in the FH+ group (P<0.05). The FH+ group exhibited higher casual blood pressure, prolonged resting blood pressure, heart rate and plasma norepinephrine levels than the FH- group (P<0.05), suggesting an increased sympathetic tone in these subjects. The reflex tachycardia was depressed in the FH+ group.
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The reasons for the inconsistent association between salt consumption and blood pressure levels observed in within-society surveys are not known. A total of 157 normotensive subjects aged 18 to 35 years, selected at random in a cross-sectional population-based survey, answered a structured questionnaire. They were classified as strongly predisposed to hypertension when two or more first-degree relatives had a diagnosis of hypertension. Anthropometric parameters were obtained and sitting blood pressure was determined with aneroid sphygmomanometers. Sodium and potassium excretion was measured by flame spectrophotometry in an overnight urine sample. A positive correlation between blood pressure and urinary sodium excretion was detected only in the group of individuals strongly predisposed to hypertension, both for systolic blood pressure (r = 0.51, P<0.01) and diastolic blood pressure (r = 0.50, P<0.01). In a covariance analysis, after controlling for age, skin color and body mass index, individuals strongly predisposed to hypertension who excreted amounts of sodium above the median of the entire sample had higher systolic and diastolic blood pressure than subjects classified into the remaining conditions. The influence of familial predisposition to hypertension on the association between salt intake and blood pressure may be an additional explanation for the weak association between urinary sodium excretion and blood pressure observed in within-population studies, since it can influence the association between salt consumption and blood pressure in some but not all inhabitants.
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Levels of methylmalonic acid (MMA) comparable to those of human methylmalonic acidemia were achieved in blood (2-2.5 mmol/l) and brain (1.35 µmol/g) of rats by administering buffered MMA, pH 7.4, subcutaneously twice a day from the 5th to the 28th day of life. MMA doses ranged from 0.76 to 1.67 µmol/g as a function of animal age. Control rats were treated with saline in the same volumes. The animals were sacrificed by decapitation on the 28th day of age. Blood was taken and the brain was rapidly removed. Medulla, pons, the olfactory lobes and cerebellum were discarded and the rest of the brain ("cerebrum") was isolated. Body and "cerebrum" weight were measured, as well as the cholesterol and triglyceride concentrations in blood and the content of myelin, total lipids, and the concentrations of the lipid fractions (cholesterol, glycerolipids, phospholipids and ganglioside N-acetylneuraminic acid (ganglioside-NANA)) in the "cerebrum". Chronic MMA administration had no effect on body or "cerebrum" weight, suggesting that the metabolites per se neither affect the appetite of the rats nor cause malnutrition. In contrast, MMA caused a significant reduction of plasma triglycerides, but not of plasma cholesterol levels. A significant diminution of myelin content and of ganglioside-NANA concentration was also observed in the "cerebrum". We propose that the reduction of myelin content and ganglioside-NANA caused by MMA may be related to the delayed myelination/cerebral atrophy and neurological dysfunction found in methylmalonic acidemic children.