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UNLABELLED: Inhalation of infected brain homogenate results in transepithelial transport of prions across the nasal mucosa of hamsters, some of which occurs rapidly in relatively large amounts between cells (A. E. Kincaid, K. F. Hudson, M. W. Richey, and J. C. Bartz, J. Virol 86:12731-12740, 2012, doi:http://dx.doi.org/10.1128/JVI.01930-12). Bulk transepithelial transport in the nasal cavity has not been studied to date. In the present study, we characterized the frequency, size, and specificity of the intercellular spaces that mediate the bulk transport of inhaled prions between cells of mice or hamsters following extranasal inoculation with mock-infected brain homogenate, different strains of prion-infected brain homogenate, or brain homogenate mixed with India ink. Infected or mock-infected inoculum was identified within lymphatic vessels of the lamina propria and in spaces of >5 µm between a small number of cells of the nasal mucosa in >90% of animals from 5 to 60 min after inhalation. The width of the spaces between cells, the amount of the inoculum within the lumen of lymphatic vessels, and the timing of the transport indicate that this type of transport was taking place through preexisting spaces in the nasal cavity that were orders of magnitude wider than what is normally reported for paracellular transport. The indiscriminate rapid bulk transport of brain homogenate in the nasal cavity results in immediate entry into nasal cavity lymphatics following inhalation. This novel mechanism may underlie the recent report of the early detection of prions in blood following inhalation and has implications for horizontal prion transmission. IMPORTANCE: The results of these studies demonstrate that the nasal mucosa of mice and hamsters is not an absolute anatomical barrier to inhaled prion-infected or uninfected brain homogenate. Relatively large amounts of infected and uninfected brain homogenate rapidly cross the nasal mucosa and enter the lumen of lymphatic vessels following inhalation. These bulk transepithelial transport events were relatively rare but present in >90% of animals 5 to 60 min following inhalation. This novel mechanism of bulk transepithelial transport was seen in experimental and control hamsters and mice, indicating that it was not species specific or in response to prion exposure. The indiscriminate bulk intercellular transport of inhaled pathogens across the nasal mucosa followed by entry into the lymphatic system may be a mechanism that underlies the entry and spread of other toxins and pathogens in olfactory system-driven animals.
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Cavidade Nasal/fisiologia , Príons/metabolismo , Animais , Transporte Biológico , Cricetinae , Camundongos , Fatores de TempoRESUMO
The postharvest development of bacterial soft rot in tomato fruit caused by Pectobacterium carotovorum is herein linked with inoculation of lenticel-like apertures located around the stem attachment. Stem scars misted with aqueous cell suspensions of P. carotovorum (1 × 106 CFU/ml) or briefly (5 s) immersed in the suspension were likely to become infected during subsequent storage, with a disease incidence exceeding 70% within 7 days at 24°C. Water soaking was initially observed beneath the fruit surface at the juncture of radial walls of endocarp tissues and a corky ring around the stem attachment. If fruit were swirled for 1 min in chlorine at 150 ppm, pH 6.5, within 5 s after inoculation, lesions did not occur. However, if the chlorine treatment was delayed by 120 s, lesions occasionally developed. A 60-min delay usually assured that decay would occur before fruit ripened (within 5 days). Delaying the chlorine wash by 18 h, as would occur if commercial harvests were held overnight prior to packing operations, led to the same incidence of bacterial soft rot as observed among control fruit. Inoculation of fruit with attached stems did not lead to as much decay during storage compared with stemless fruit, suggesting that an intact calyx physically reduced lenticel exposure to external aqueous cell suspensions. Tomato fruit exposed to uncontrolled free moisture during or shortly after harvest have a high potential for postharvest decays and the likely site for infection development is the area surrounding the stem attachment.
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The endogenous opioid system is thought to play an important role in mother-infant attachment. In infant rhesus macaques, variation in the µ-opioid receptor gene (OPRM1) is related to differences in attachment behavior that emerges following repeated separation from the mother; specifically, infants carrying at least one copy of the minor G allele of the OPRM1 C77G polymorphism show heightened and more persistent separation distress, as well as a pattern of increased contact-seeking behavior directed towards the mother during reunions (at the expense of affiliation with other group members). Research in adult humans has also linked the minor G allele of the analogous OPRM1 A118G polymorphism with greater interpersonal sensitivity. Adopting an interactionist approach, we examined whether OPRM1 A118G genotype and maternal (in)sensitivity are associated with child attachment style, predicting that children carrying the G allele may be more likely to develop an ambivalent attachment pattern in response to less sensitive maternal care. The sample consisted of 191 mothers participating with their children (n = 223) in the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) project, a community-based, birth cohort study of Canadian mothers and their children assessed longitudinally across the child's development. Maternal sensitivity was coded from at-home mother-child interactions videotaped when the child was 18 months of age. Child attachment was assessed at 36 months using the Strange Situation paradigm. As predicted, G allele carriers, but not AA homozygotes, showed increasing odds of being classified as ambivalently attached with decreasing levels of maternal sensitivity. Paralleling earlier non-human animal research, this work provides support for the theory that endogenous opioids contribute to the expression of attachment behaviors in humans.
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Relações Mãe-Filho , Polimorfismo Genético , Adulto , Feminino , Humanos , Canadá , Estudos de Coortes , Genótipo , Polimorfismo de Nucleotídeo Único , Receptores Opioides mu/genéticaRESUMO
Chronic wasting disease (CWD), a prion disease of North American deer, elk and moose, affects both free-ranging and captive cervids. The potential host range for CWD remains uncertain. The susceptibility of the ferret to CWD was examined experimentally by administering infectious brain material by the intracerebral (IC) or oral (PO) route. Between 15 and 20 months after IC inoculation, ferrets developed neurological signs consistent with prion disease, including polyphagia, somnolence, piloerection, lordosis and ataxia. Upon first sub-passage of ferret-adapted CWD, the incubation period decreased to 5 months. Spongiform change in the neuropil was most marked in the basal ganglia, thalamus, midbrain and pons. The deposition of PrP(CWD) was granular and was occasionally closely associated with, or localized within, neurons. There were no plaque-like or perivascular PrP aggregates as seen in CWD-infected cervids. In western blots, the PrP(CWD) glycoform profile resembled that of CWD in deer, typified by a dominant diglycosylated glycoform. CWD disease in ferrets followed IC but not PO inoculation, even after 31 months of observation. These findings indicate that CWD-infected ferrets share microscopical and biochemical features of CWD in cervids, but appear to be relatively resistant to oral infection by primary CWD inoculum of deer origin.
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Encéfalo/patologia , Furões , Doença de Emaciação Crônica/patologia , Animais , Encéfalo/metabolismo , Cervos , Modelos Animais de Doenças , Neurópilo/metabolismo , Neurópilo/patologia , Príons , Taxa de Sobrevida , Doença de Emaciação Crônica/mortalidade , Doença de Emaciação Crônica/fisiopatologiaRESUMO
OBJECTIVE: To assess tolerance and safety of 0.6% chlorhexidine vaginal and neonatal wipes to improve perinatal outcomes in home deliveries in Pakistan and the ability of traditional birth attendants and project staff to perform a randomized trial of this intervention. METHODS: Focus groups of pregnant and nonpregnant women and in-depth interviews of traditional birth attendants explored barriers to the use of chlorhexidine wipes. Then, a study was performed of women delivering at home attended by traditional birth attendants. Consenting women were randomly assigned to receive either 0.6% chlorhexidine or saline vaginal and neonatal wipes. Women and their infants were followed up on postpartum days 7, 14, and 28. Acceptability and tolerance of vaginal and neonatal wipes, as well as maternal and neonatal outcomes, were assessed. RESULTS: The focus groups and interviews indicated that the chlorhexidine intervention would be acceptable to women and their providers. Of the 213 eligible pregnant women approached, 203 (95%) gave informed consent and were enrolled and allocated to groups. Traditional birth attendants had no difficulty administering chlorhexidine vaginal and neonatal wipes in a home setting. Of the 203 births, 103 (51%) of whom received 0.6% chlorhexidine, there were no allergic reactions, vaginal itching, burning, or requests for study termination. Follow-up at 28 days postpartum was more than 95%. Although this study was not powered to show significant differences in neonatal outcomes between treatment groups, the lower rates of some neonatal adverse clinical outcomes in the chlorhexidine group were encouraging. CONCLUSION: Use of 0.6% chlorhexidine vaginal and neonatal wipes for the prevention of neonatal infection is well-tolerated and seems safe. A trial of this intervention by traditional birth attendants in a home-delivery setting is feasible. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00121394 LEVEL OF EVIDENCE: I.
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Anti-Infecciosos Locais/uso terapêutico , Clorexidina/uso terapêutico , Parto Domiciliar/métodos , Adulto , Estudos de Viabilidade , Feminino , Grupos Focais , Humanos , Mortalidade Infantil , Recém-Nascido , Doenças do Recém-Nascido/prevenção & controle , Infecções/transmissão , Masculino , Tocologia , Paquistão/epidemiologia , Cooperação do Paciente , Projetos Piloto , GravidezRESUMO
The control of postharvest Botrytis fruit rot was evaluated during 1997-98 and 1998-99. Weekly applications of captan and thiram were examined at two or three different rates, respectively. Iprodione applications were combined with the captan and thiram treatments and also applied alone for two peak bloom periods. Strawberry fruit were harvested and graded twice weekly for marketable yield and preharvest incidence of Botrytis fruit rot. For postharvest evaluations, fruit from four harvests were selected and stored at 4°C, and Botrytis fruit rot incidence was recorded over 14 days of storage. Fungicide treatments reduced the incidence of preharvest Botrytis fruit rot and increased marketable yield. The incidence of postharvest Botrytis fruit rot was significantly affected by harvest date, length of time in storage, and fungicide treatment. The highest rate captan and thiram treatments had the least Botrytis fruit rot and the longest storage life. Reduced-rate captan and thiram treatments generally did not provide the same control as their respective high-rate treatments. Iprodione added to either the captan or thiram treatments did not consistently reduce the preharvest or postharvest incidence of Botrytis fruit rot or increase yield. Regular, full-rate fungicide treatments appear to be necessary to control Botrytis fruit rot in Florida and to provide the storage life necessary to reach distant markets.
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Chlorine concentrations (pH 6 to 7 and 22 to 27°C) that killed arthrospores (spores) of Geotrichum candidum or sporangioles (spores) of Rhizopus stolonifer, causal agents of sour rot and Rhizopus rot, respectively, in moving water within 30 to 45 s did not prevent these pathogens from inoculating wounded tomatoes (Lycopersicon esculentum) in a water flume containing chlorine and spores. Free chlorine concentrations of 20 or 25 mg/liter were lethal to spores of G. candidum within 30 s in most in vitro tests, whereas spores of R. stolonifer were slightly less sensitive. Wounded tomatoes placed in a flume with free chlorine at 30 mg/liter and then exposed to spores for 1 min developed about 50% less decay incidence during storage at 24°C for 6 days than did fruit exposed to spores and water alone. In the absence of chlorine, incidence averaged 57% (range, 15 to 95%) for R. stolonifer and 38% (range, 17 to 58%) for G. candidum. Sporadic sour rot lesions were observed among fruit that had been treated with free chlorine at 75 mg/liter, whereas chlorine at up to 180 mg/liter failed to completely protect fruit from Rhizopus rot. A water-soluble dye rapidly penetrated wounds on tomato fruit. The dye framed the outlines of cells at the wound surface and appeared to penetrate into a few intercel-lular spaces. Application of 1% sodium hypochlorite decolorized the dye on the wound surface, whereas deposits located below the wound surface remained blue. Thus, spores suspended in moving water can escape the action of chlorine if carried into intercellular spaces by diffusion or by capillary movement of cell sap and water.
RESUMO
For the first time, the authors are describing an automatic fluorescent nuclear track detector (FNTD) reader for neutron dosimetry. FNTD is a luminescent integrating type of detector made of aluminium oxide crystals that does not require electronics or batteries during irradiation. Non-destructive optical readout of the detector is performed using a confocal laser scanning fluorescence imaging with near-diffraction limited resolution. The fully automatic table-top reader allows one to load up to 216 detectors on a tray, read their engraved IDs using a CCD camera and optical character recognition, scan and process simultaneously two types of images in fluorescent and reflected laser light contrast to eliminate false-positive tracks related to surface and volume crystal imperfections. The FNTD dosimetry system allows one to measure neutron doses from 0.1 mSv to 20 Sv and covers neutron energies from thermal to 20 MeV. The reader is characterised by a robust, compact optical design, fast data processing electronics and user-friendly software.
Assuntos
Nêutrons Rápidos , Nêutrons , Polímeros/química , Proteção Radiológica/instrumentação , Radiometria/instrumentação , Óxido de Alumínio/química , Amerício , Berílio , Calibragem , Carbonatos/química , Microscopia Confocal/métodos , Distribuição Normal , Doses de Radiação , Proteção Radiológica/métodos , Radioisótopos , Radiometria/métodos , Reprodutibilidade dos Testes , Fatores de TempoRESUMO
Fluorescent nuclear track detectors (FNTDs) based on Al2O3: C, Mg single crystal combined with confocal microscopy provide 3D information on ion tracks with a resolution only limited by light diffraction. FNTDs are also ideal substrates to be coated with cells to engineer cell-fluorescent ion track hybrid detectors (Cell-Fit-HD). This radiobiological tool enables a novel platform linking cell responses to physical dose deposition on a sub-cellular level in proton and heavy ion therapies. To achieve spatial correlation between single ion hits in the cell coating and its biological response the ion traversals have to be reconstructed in 3D using the depth information gained by the FNTD read-out. FNTDs were coated with a confluent human lung adenocarcinoma epithelial (A549) cell layer. Carbon ion irradiation of the hybrid detector was performed perpendicular and angular to the detector surface. In situ imaging of the fluorescently labeled cell layer and the FNTD was performed in a sequential read-out. Making use of the trajectory information provided by the FNTD the accuracy of 3D track reconstruction of single particles traversing the hybrid detector was studied. The accuracy is strongly influenced by the irradiation angle and therefore by complexity of the FNTD signal. Perpendicular irradiation results in highest accuracy with error of smaller than 0.10°. The ability of FNTD technology to provide accurate 3D ion track reconstruction makes it a powerful tool for radiobiological investigations in clinical ion beams, either being used as a substrate to be coated with living tissue or being implanted in vivo.
Assuntos
Processamento de Imagem Assistida por Computador/métodos , Íons , Radiometria/instrumentação , Radiometria/métodos , Óxido de Alumínio/química , Carbono , Linhagem Celular Tumoral , Radioterapia com Íons Pesados/métodos , Humanos , Imageamento Tridimensional/métodos , Íons/química , Transferência Linear de Energia , Reprodutibilidade dos TestesRESUMO
PURPOSE: To construct a custom confocal laser scanning microscope (CLSM) capable of resolving individual proton tracks in the volume of an Al2 O3 :C,Mg fluorescent nuclear track detector (FNTD). The spatial resolution of the FNTD technique is at the sub-micrometer scale. Therefore the FNTD technique has the potential to perform radiation measurements at the cell nucleus scale. METHODS: The crystal volume of an FNTD contains defects which become fluorescent F2+ centers after trapping delta electrons from ionizing radiation. These centers have an absorption band centered at 620 nm and an emission band in the near infrared. Events of energy deposition in the crystal are read-out using a CLSM with sub-micrometer spatial resolution. Excitation light from a 635 nm laser is focused in the crystal volume by an objective lens. Fluorescence is collected back through the same path, filtered through a dichroic mirror, and focused through a small pinhole onto an avalanche photodiode. Lateral scanning of the focal point is performed with a scanning mirror galvanometer, and axial scanning is performed using a stepper-motor stage. Control of electronics and image acquisition was performed using a custom built LabVIEW VI and further image processing was done using Java. The system was used to scan FNTDs exposed to a 6 MV x-ray beam and an unexposed FNTD. RESULTS: Fluorescence images above the unexposed background were obtained at scan depths ranging from 5 - 10 micrometer below the crystal surface using a 100 micrometer pinhole size. CONCLUSIONS: Further work needs to be done to increase the resolution and the signal to noise ratio of the images so that energy deposition events may be identified more easily. Natural Sciences and Engineering Research Council of Canada.
RESUMO
A neutron field characterisation was conducted at the AREVA Melox Plant to determine the response of passive and active neutron dosemeters for several stages in the mixed oxide fuel manufacturing process. Landauer Europe provides radiation dosimetry to many contractors working at the Melox site. The studies were conducted to assist in determining the neutron radiation fields the workers are exposed to routinely, evaluate the need for specific neutron correction factors and to ensure that the most accurate neutron dose is reported for the Melox Plant workers.
Assuntos
Óleos Combustíveis , Nêutrons , Exposição Ocupacional/análise , Centrais Elétricas , Monitoramento de Radiação/normas , Proteção Radiológica/normas , Radiometria , Europa (Continente) , Humanos , Exposição Ocupacional/prevenção & controle , Óxidos/química , Garantia da Qualidade dos Cuidados de Saúde , Doses de Radiação , Medição de Risco , Gestão da SegurançaRESUMO
Oxytocin has known stress-reducing and attachment-enhancing effects. We thus hypothesized that oxytocin would attenuate emotional and hormonal responses to stress in borderline personality disorder (BPD). Fourteen BPD and 13 healthy control (HC) adults received 40 IU intranasal oxytocin or placebo in double-blind randomized order followed by the Trier Social Stress Test. Subjective dysphoria (Profile of Mood Changes) and plasma cortisol levels were measured. Childhood trauma history, attachment style, and self-esteem were also rated. A significant "Group × Drug × Time" interaction effect for dysphoria (p=.04) reflected a proportionately greater attenuation of stress-induced dysphoria in the BPD group after oxytocin administration. Additionally, a marginally significant "Group × Drug" interaction effect for cortisol (p=.10) reflected a tendency toward greater attenuation of the stress-induced cortisol surge in the BPD group after oxytocin administration. In the combined sample, the oxytocin-placebo difference in the emotional stress reactivity was significantly predicted by childhood trauma alone (p=.037) and combined with self-esteem (p=.030), whereas the oxytocin-placebo difference in cortisol stress reactivity was predicted only by insecure attachment (p=.013). Results suggest that oxytocin may have a beneficial impact on emotional regulation in BPD, which merits further investigation and could have important treatment implications.
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Transtorno da Personalidade Borderline/fisiopatologia , Transtorno da Personalidade Borderline/psicologia , Ocitocina/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Administração Intranasal , Adulto , Transtorno da Personalidade Borderline/sangue , Método Duplo-Cego , Regulação para Baixo/efeitos dos fármacos , Feminino , Hormônios/sangue , Humanos , Masculino , Testes Neuropsicológicos , Ocitocina/administração & dosagem , Projetos Piloto , Placebos , Autoimagem , Estresse Fisiológico/fisiologiaAssuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Neuropatias Diabéticas/epidemiologia , Hemoglobinas Glicadas/metabolismo , Adolescente , Adulto , Sistema Nervoso Autônomo/fisiopatologia , Criança , Diabetes Mellitus Tipo 1/sangue , Neuropatias Diabéticas/fisiopatologia , Neuropatias Diabéticas/prevenção & controle , Feminino , Hemoglobinas Glicadas/análise , Coração/inervação , Humanos , Incidência , Masculino , Valores de ReferênciaAssuntos
Adenosina/metabolismo , Escherichia coli/enzimologia , Mycoplasma/enzimologia , RNA de Transferência/metabolismo , Transferases/metabolismo , Sequência de Bases , Centrifugação com Gradiente de Concentração , Difosfatos/metabolismo , Isomerases/metabolismo , Métodos , Peso Molecular , Fosfatos/metabolismo , Isótopos de Fósforo , Permanganato de Potássio/farmacologia , Purinas/metabolismo , RNA Bacteriano/metabolismo , RNA de Transferência/análise , Ribose/metabolismo , Transferases/antagonistas & inibidores , Transferases/isolamento & purificação , TrítioRESUMO
This study examined the prevalence of HIV and other sexually transmitted infections (STIs) in pregnant women in Kinshasa, the Democratic Republic of the Congo (DRC). Between April and July 2004, antenatal attendees at two of the largest maternity clinics in Kinshasa were tested to identify HIV status, syphilis, Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). HIV seroprevalence was 1.9% in 2082 women. With PCR techniques, CT and NG infections were also uncommon in the first 529 women (1.7% and 0.4%, respectively). No active syphilis infection case was identified by Treponema pallidum haemagglutination assay (TPHA) and rapid plasma reagin test (RPR). A woman's risk of HIV infection was significantly associated with her reporting a male partner having had other female sexual partners (OR 2.7, 95% CI 1.2-6.2). The continuing low seroprevalence of HIV in pregnant women from Kinshasa was confirmed. Understanding factors associated with this phenomenon could help prevent a future HIV epidemic in low HIV transmission areas in Africa.
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Infecções por HIV/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Infecções Sexualmente Transmissíveis/epidemiologia , Adulto , Infecções por Chlamydia/diagnóstico , Infecções por Chlamydia/epidemiologia , República Democrática do Congo/epidemiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Gonorreia/diagnóstico , Gonorreia/epidemiologia , Infecções por HIV/diagnóstico , Humanos , Modelos Logísticos , Reação em Cadeia da Polimerase , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Prevalência , Fatores de Risco , Infecções Sexualmente Transmissíveis/diagnóstico , Sífilis/diagnóstico , Sífilis/epidemiologiaRESUMO
To compare clinicopathologic findings of transmissible mink encephalopathy (TME) with other transmissible spongiform encephalopathies (TSE, prion diseases) that have been shown to be experimentally transmissible to cattle (sheep scrapie and chronic wasting disease [CWD]), two groups of calves (n = 4 each) were intracerebrally inoculated with TME agents from two different sources (mink with TME and a steer with TME). Two uninoculated calves served as controls. Within 15.3 months postinoculation, all animals from both inoculated groups developed clinical signs of central nervous system (CNS) abnormality; their CNS tissues had microscopic spongiform encephalopathy (SE); and abnormal prion protein (PrP(res)) as detected in their CNS tissues by immunohistochemistry (IHC) and Western blot (WB) techniques. These findings demonstrate that intracerebrally inoculated cattle not only amplify TME PrP(res) but also develop clinical CNS signs and extensive lesions of SE. The latter has not been shown with other TSE agents (scrapie and CWD) similarly inoculated into cattle. The findings also suggest that the diagnostic techniques currently used for confirmation of bovine spongiform encephalopathy (BSE) would detect TME in cattle should it occur naturally. However, it would be a diagnostic challenge to differentiate TME in cattle from BSE by clinical signs, neuropathology, or the presence of PrP(res) by IHC and WB.
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Encéfalo/patologia , Doenças dos Bovinos/transmissão , Doenças Priônicas/veterinária , Príons/metabolismo , Animais , Bovinos , Masculino , Doenças Priônicas/transmissãoRESUMO
Many studies involving exercise testing fail to address the issue of practice. Those that do vary considerably with respect to the parameters of practice used. We evaluated the effect of two standardized practices on a horizontal submaximal exercise test performed on a treadmill. Healthy men (n = 20) with no previous treadmill exposure were alternately assigned to the experimental (practice) or control (no practice) group. Heart rate (HR), systolic blood pressure (SBP), rate pressure product (RPP), step cadence (CAD) and perceived exertion (PE) were recorded at the end of each work load of the practices and/or tests. We observed no significant differences in these variables over the common work loads for the first practice session in the experimental group and the exercise test in the control group (p greater than 0.05). The two groups were homogeneous with respect to fitness and magnitude of arousal on initial exposure to the treadmill. During the submaximal test, HR, SBP, RPP, CAD, and PE were systematically lower for the experimental group than for the control group. The SBP and RPP were significantly lower in the experimental group (p less than 0.01). The CAD tended toward statistical significance (p less than 0.07), whereas HR and PE were not significantly different for the two groups (p greater than 0.05). When the four common work loads were compared over the two practices and the exercise test for the experimental group, SBP and CAD were significantly higher for practice 1 than for practice 2 and the test (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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Teste de Esforço/métodos , Estresse Fisiológico/fisiopatologia , Adulto , Pressão Sanguínea , Eficiência , Ergonomia , Marcha , Habituação Psicofisiológica , Frequência Cardíaca , Humanos , Masculino , Esforço Físico , Distribuição AleatóriaRESUMO
The distribution of the two cytokinin-active ribonucleosides 6-(3-methyl-2-butenylamino)-9-beta-D-ribofuranosylpurine (1) and 6-(3-methyl-2-butenylamino)-2-methylthio-9-beta-D-ribofuranosylpurine (2) in tRNA(Phe), tRNA(UUG) (Leu), tRNA(UCR) (Ser), tRNA(Tyr), tRNA(Cys), and tRNA(2) (Trp) from stationary phase Escherichia coli has been studied. Compound 2 predominated in all these species except tRNA(Phe), in which compound 1 was greatly in excess. Compound 1 was present in relatively small amounts in tRNA(UUG) (Leu), tRNA(Cys), and tRNA(2) (Trp), and was not detected in tRNA(UCR) (Ser) and tRNA(Tyr). Cells from the early logarithmic phase had the highest cytokinin content in their tRNA. Stationary phase tRNA had a slight increase in the amount of 1, which may be explained by the appearance of the new tRNA(Phe). No differences were observed between the chromatographic patterns of tRNAs from early-, mid-, and latelogarithmic phases.
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Escherichia coli/crescimento & desenvolvimento , Cininas/isolamento & purificação , Nucleosídeos/isolamento & purificação , RNA Bacteriano/análise , Aminoácidos/análise , Cromatografia , Métodos , RNA Nucleotidiltransferases , RNA de Transferência/análiseRESUMO
BACKGROUND AND OBJECTIVE: Weight gain is a common undesirable side effect of insulin treatment in type 1 diabetics. This study tested the assumption that this is due to an increase in fat mass. PATIENTS AND METHOD: Bioelectric impedance measurements were performed on 157 young male and 117 female diabetics (age 17.6 +/- 4.9 years; diabetes duration 8.9 +/- 5.7 years) and the fat-free mass (FFM) calculated according to the equation of Schfer et al. The data of the diabetics were compared with those of healthy controls and normal values published by Barlett et al. RESULTS: The average weight of the diabetic cohort was 2.0 +/- 0.7 kg higher than in the reference groups, adjusted for sex and age. FFM was higher by 2.9 +/- 0.7 kg in diabetics than in the healthy cohort of Barlett et al (P < 0.005), being equally high in males and females (+2.9 +/- 0.7 kg and 2.9 +/- 0.6 kg, respectively). But compared with the values in metabolically normal controls the percentage fat proportion was lower in the diabetics than the controls, but not significantly (-1.3 +/- 0.6%). Weight gain was greater in females than males (+3.8 +/- 0.9 kg vs +1.2 +/- 0.9 kg, P < 0.05). After correcting for age, there was a partial correlation between good metabolic control and FFM in males. The form of treatment had no effect on body composition. CONCLUSION: These data indicate that weight gain in young diabetics is due not to an increase in fatty tissue but in muscle mass. This is probably the result of peripheral hyperinsulinism combined with hyperglycaemia.