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1.
Soc Psychiatry Psychiatr Epidemiol ; 56(7): 1147-1160, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33866384

RESUMO

PURPOSE: To assess the quality of the research about how employment conditions and psychosocial workplace exposures impact the mental health of young workers, and to summarize the available evidence. METHODS: We undertook a systematic search of three databases using a tiered search strategy. Studies were included if they: (a) assessed employment conditions such as working hours, precarious employment, contract type, insecurity, and flexible work, or psychosocial workplace exposures such as violence, harassment and bullying, social support, job demand and control, effort-reward imbalance, and organizational justice; (b) included a validated mental health measure; and (c) presented results specific to young people aged ≤ 30 years or were stratified by age group to provide an estimate for young people aged ≤ 30 years. The quality of included studies was assessed using the Risk of Bias in Non-randomized Studies of Exposures (ROBINS-E) tool. RESULTS: Nine studies were included in the review. Four were related to employment conditions, capturing contract type and working hours. Five studies captured concepts relevant to psychosocial workplace exposures including workplace sexual harassment, psychosocial job quality, work stressors, and job control. The quality of the included studies was generally low, with six of the nine at serious risk of bias. Three studies at moderate risk of bias were included in the qualitative synthesis, and results of these showed contemporaneous exposure to sexual harassment and poor psychosocial job quality was associated with poorer mental health outcomes among young workers. Longitudinal evidence showed that exposure to low job control was associated with incident depression diagnosis among young workers. CONCLUSIONS: The findings of this review illustrate that even better studies are at moderate risk of bias. Addressing issues related to confounding, selection of participants, measurement of exposures and outcomes, and missing data will improve the quality of future research in this area and lead to a clearer understanding of how employment conditions and psychosocial workplace exposures impact the mental health of young people. Generating high-quality evidence is particularly critical given the disproportionate impact of COVID-19 on young people's employment. In preparing for a post-pandemic world where poor-quality employment conditions and exposure to psychosocial workplace exposures may become more prevalent, rigorous research must exist to inform policy to protect the mental health of young workers.


Assuntos
Emprego , Saúde Mental , Local de Trabalho , Adulto , Humanos , Cultura Organizacional , Justiça Social , Adulto Jovem
2.
BMC Psychiatry ; 19(1): 146, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31088405

RESUMO

BACKGROUND: Construction workers are at elevated risk of suicide. MATES in Construction (MATES) is one of the few suicide prevention programs that explicitly address this problem. The MATES program includes an integrated system of services that supports prevention, early intervention and recovery (i.e., primary, secondary and tertiary prevention) for mental health problems among construction workers. In this protocol, we describe a proposed evaluation of MATESmobile, an electronic platform which will be accessed by workers who have undergone MATES training. METHODS/DESIGN: In this protocol, we describe a Randomised Controlled Trial (RCT) which seeks to assess whether MATESmobile results in improved literacy regarding suicide prevention, and improved help-seeking and help-offering attitudes among those who have attended MATES training. Secondary outcomes include changes in suicide ideation, suicide attempt and psychological distress. Workers will be recruited prior to MATES face-to-face training. In total, 295 workers will be randomly assigned to the intervention condition (MATESmobile + face-to-face training) and 295 will be randomly allocated to the control (face-to-face training). The intervention will run for 8 weeks. Assessments will be run immediately post intervention, and at 3, 6, and 12 months DISCUSSION: MATESmobile offers the potential to reinforce and enhance the effects of face-to-face training, resulting in greater skills and knowledge in suicide prevention, as well as a reduction in suicidality and distress. TRIAL REGISTRATION: This trial is registered with the Australian New Zealand Clinical Trials Registry ( ACTRN12619000625178 ; 26 April 2019).


Assuntos
Indústria da Construção , Smartphone , Ideação Suicida , Prevenção do Suicídio , Suicídio/psicologia , Adulto , Austrália/epidemiologia , Feminino , Humanos , Masculino
3.
Public Health ; 165: 34-41, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30359784

RESUMO

OBJECTIVES: Men are less likely to seek treatment for mental health problems than women; however, the structural employment-related factors influencing this relationship are unknown. STUDY DESIGN: This is a prospective cohort study. METHODS: Using the Australian Ten to Men cohort (N = 6447), we examined the relationship between being in a male-dominated occupation and treatment seeking from a mental health professional compared to being in a gender-equal occupation. Models were fit using logistic regression. RESULTS: There was some evidence of a stepwise gradient between male-dominated occupations and treatment seeking for mental health problems. However, results were only significant for the most male-dominated occupations after adjustment (odds ratio [OR] 0.70, 95% confidence interval [CI] 0.52 to 0.94, P = 0.017). We also found evidence that individuals who more strongly adhered to masculine norms had a lower likelihood of treatment seeking (OR = 0.97, 95% CI 0.95 to 0.99, P = 0.004). CONCLUSIONS: This supports the idea that occupational-related factors influence male treatment seeking for mental health problems.


Assuntos
Emprego/estatística & dados numéricos , Serviços de Saúde Mental/estatística & dados numéricos , Ocupações/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Adolescente , Adulto , Austrália , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
4.
J Fish Biol ; 86(4): 1251-70, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25727098

RESUMO

Microsatellite DNA and mitochondrial DNA control-region sequence analyses were used to determine the population and distinct population segment (DPS) origin of 173 Atlantic sturgeon Acipenser oxyrinchus oxyrinchus encountered from the Gulf of Maine to Cape Hatteras, North Carolina, in NOAA's Northeast Fisheries Observer Program. It was found that the Hudson River was by far the greatest contributor to this coastal by-catch, with 42·2-46·3% of specimens originating there. Generally, specimens represented the geographic province of the river in which they were spawned, but some specimens, particularly those originating in the South Atlantic DPS, moved to great distances. Genetic mixed-stock analyses provide an accurate approach to determine the DPS and population origin of A. o. oxyrinchus by-catch in coastal waters, but most informative management requires that these results be partitioned by locale, season, target fishery and gear type.


Assuntos
Peixes/genética , Genética Populacional , Animais , Oceano Atlântico , DNA Mitocondrial/genética , Pesqueiros , Repetições de Microssatélites , Análise de Sequência de DNA , Estados Unidos
5.
Annu Rev Biomed Eng ; 13: 55-72, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21513459

RESUMO

High-quality, in vitro screening tools are essential in identifying promising compounds during drug development. Tests with currently used cell-based assays provide an indication of a compound's potential therapeutic benefits to the target tissue, but not to the whole body. Data obtained with animal models often cannot be extrapolated to humans. Multicompartment microfluidic-based devices, particularly those that are physical representations of physiologically based pharmacokinetic (PBPK) models, may contribute to improving the drug development process. These scaled-down devices, termed micro cell culture analogs (µCCAs) or body-on-a-chip devices, can simulate multitissue interactions under near-physiological fluid flow conditions and with realistic tissue-to-tissue size ratios. Because the device can be used with both animal and human cells, it can facilitate cross-species extrapolation. Used in conjunction with PBPK models, the devices permit an estimation of effective concentrations that can be used for studies with animal models or predict the human response. The devices also provide a means for relatively high-throughput screening of drug combinations and, when utilized with a patient's tissue sample, an opportunity for individualized medicine. Here we review efforts made toward the development of microfabricated cell culture systems and give examples that demonstrate their potential use in drug development, such as identifying synergistic drug interactions as well as simulating multiorgan metabolic interactions. In addition to their use in drug development, the devices also can be used to estimate the toxicity of chemicals as occupational hazards and environmental contaminants.


Assuntos
Técnicas Analíticas Microfluídicas , Modelos Biológicos , Preparações Farmacêuticas/metabolismo , Farmacocinética , Animais , Bioensaio , Comunicação Celular/fisiologia , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Interações Medicamentosas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Camundongos , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Miniaturização , Preparações Farmacêuticas/administração & dosagem , Ratos , Especificidade da Espécie , Técnicas de Cultura de Tecidos , Engenharia Tecidual/métodos
6.
J Glob Antimicrob Resist ; 24: 321-324, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33508483

RESUMO

OBJECTIVES: Klebsiella michiganensis is an emerging pathogen implicated in nosocomial infections. Here we report on the resistome, virulome and mobilome of a carbapenemase-producing K. michiganensis isolate from urban hospital effluent in Pietermaritzburg, KwaZulu-Natal, South Africa. Klebsiella sp. isolate KP124 was originally isolated from the final effluent of an urban tertiary hospital in Pietermaritzburg, KwaZulu-Natal. METHODS: Following phenotypic characterisation and antibiotic susceptibility testing, the genome of carbapenemase-producing isolate KP124 was sequenced using an Illumina MiSeq platform, de novo assembled and analysed using established bioinformatics tools. RESULTS: The draft genome of strain KP124 was 6 544 586 bp in length, comprising 203 contigs >200 bp. Following confirmation of isolate KP124 as K. michiganensis using reference genomes, the blaOXA-181 carbapenemase gene as well as 11 additional genes encoding resistance against ß-lactams, aminoglycosides, fluoroquinolones and sulfonamides were detected. Virulence factors enabling iron acquisition and cell adherence, capsule locus type and plasmid replicon types were identified. CONCLUSION: This study represents the first report of an OXA-181 carbapenemase-producing K. michiganensis isolate from hospital effluent in South Africa. The presence of such a strain in the environment owing to the absence of hospital effluent treatment presents a potential risk to informal communities that may use contaminated surface water domestically.


Assuntos
Farmacorresistência Bacteriana/genética , Klebsiella , Proteínas de Bactérias , Hospitais Urbanos , Klebsiella/efeitos dos fármacos , Klebsiella/genética , África do Sul , beta-Lactamases
7.
Disabil Health J ; 12(4): 537-541, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31235447

RESUMO

Employment is a fundamental Social Determinant of Health known to have large impacts on mental health and other health outcomes. Across many countries of the world, people with disabilities are much more likely to be unemployed and looking for work than those without disabilities. The deprivation of employment opportunities is likely to have notable impacts on the health of people with disabilities. In this commentary, we outline the concept of "disabling working environments," which are defined as the range of experiences that affect the likelihood of people with disabilities in obtaining and maintaining quality employment which may then affect a disabled person's health. Disabling working environments are comprised of the following three mutually reinforcing components: 1) Differential selection into work; 2) Selection into certain types of jobs and exposure to poor psychosocial working environments when in employment, and; 3) Differential selection out of work (e.g., leaving employment at an earlier age than those who do not have a disability). We argue that policy and intervention design should consider the life course effects of employment on the mental health of people with disabilities.


Assuntos
Pessoas com Deficiência , Emprego , Saúde Mental , Saúde Ocupacional , Local de Trabalho , Adulto , Feminino , Humanos , Masculino , Ocupações , Políticas , Desemprego , Trabalho
8.
Endocrinology ; 99(6): 1512-8, 1976 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1001251

RESUMO

Previous studies led us to hypothesize that brain growth was regulated by a growth hormone-dependent brain trophin. An in vitro bioassay system to assess this proposal was developed. Serum was shown to stimulate the uptake of tritiated thymidine into fetal brain cell DNA. This action could not be attributed to any nutrient contribution but was due to a non-dialyzable, heat-stable serum growth factor. The levels of the growth factor in serum were reduced after pituitary removal. When added in physiological concentration, growth hormone, prolactin, placental lactogen, insulin, nerve growth factor, thyroid and steroid hormones failed to stimulate the action of serum or to act synergistically with a serum component to stimulate DNA synthesis. Thyroxine, estradiol-17beta, and corticosterone inhibited serum activity. Administration of growth hormone to hypophysectomized rats restored serum levels to normal demonstrating that the serum growth factors was a mediating trophin responsive to pituitary growth hormone stimulation. The relationship of the brain trophin to other serum growth factors and its specificity of action remain to be defined. The present findings were in accordance with in vivo studies of hormonal influence on brain growth and support the proposal that fetal brain cell proliferation is stimulated by a serum trophin responsive to pituitary growth hormone.


Assuntos
Encéfalo/embriologia , DNA/biossíntese , Hormônio do Crescimento/farmacologia , Substâncias de Crescimento/sangue , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Corticosterona/farmacologia , Feminino , Hormônios Esteroides Gonadais/farmacologia , Substâncias de Crescimento/farmacologia , Humanos , Insulina/farmacologia , Masculino , Fatores de Crescimento Neural/farmacologia , Hipófise/fisiologia , Lactogênio Placentário/farmacologia , Prolactina/farmacologia , Ratos , Timidina/metabolismo , Hormônios Tireóideos/farmacologia
9.
J AOAC Int ; 79(3): 797-802, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8634547

RESUMO

A method is presented for estimating replicate polycyclic aromatic hydrocarbon (PAH) concentrations in American lobster (Homarus americanus) digestive gland tissue based on recoveries of added perdeuterated surrogates from a single satisfactory analysis. PAH concentrations demonstrated a large interanimal variance, even in specimens captured at the same time in the same place. Principal component analysis showed that the variability of the total system of biological variables (carapace length, lobster weight, and digestive gland weight) could be adequately summarized by the first principal component alone in each data set. Ranks provide ordered classification of individuals, allowing data analysis by statistical methods for continuous variables (i.e., analysis of variance). PAH concentrations in individual lobsters were generally highly sensitive to animal size, sex, and fishing area. Efficient monitoring would result from analyzing individual animals of a single sex from a study area, using as small a geographical study area as possible, measuring a single biological variable, and using individual specimens of as narrow a size range as possible.


Assuntos
Nephropidae/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Análise de Variância , Animais , Feminino , Masculino
10.
Mar Pollut Bull ; 44(7): 590-6, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12222881

RESUMO

3,3'-dichlorobiphenyl (IUPAC No. 11), a chlorobiphenyl (CB) that is not generally analysed in environmental studies of CBs, is found, sometimes at high concentrations, in water, suspended particulate material, biota and sediments from Halifax Harbour, NS, Canada. The results presented demonstrate the need for investigations of non-Aroclor CBs like CB 11. Not only can they have rather elevated environmental concentrations like those reported here for CB 11, but they also can be members of the more toxic non-ortho class of CBs and thus important from a toxicity standpoint. The focus of this paper was to investigate the possible sources of CB 11, a trace constituent of commercial mixtures, but dominant in various environmental compartments of Halifax Harbour.


Assuntos
Sedimentos Geológicos/química , Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , Animais , Bivalves/química , Monitoramento Ambiental , Nephropidae/química , Nova Escócia
11.
J Med Assoc Ga ; 86(2): 97-100, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9114654

RESUMO

Health care professionals who choose to treat the elderly have a responsibility to be knowledgeable about incontinence. The elderly present challenging and complex problems that may require a collaborative approach from a dedicated team, to include family members, home health nurses, continence nurses, physical therapists, as well as primary care physicians, geriatricians, urologists, and gynecologists. The elderly patient should be reminded that they are a member of that team and their commitment and participation will facilitate successful outcomes.


Assuntos
Bexiga Urinária/fisiopatologia , Incontinência Urinária/terapia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Estados Unidos/epidemiologia , Incontinência Urinária/diagnóstico , Incontinência Urinária/etiologia , Incontinência Urinária/fisiopatologia
12.
Neuroscience ; 167(2): 510-27, 2010 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-20153814

RESUMO

The nucleus tractus solitarius (nTS) of the brainstem receives sensory afferent inputs, processes that information, and sends projections to a variety of brain regions responsible for influencing autonomic and respiratory output. The nTS sends direct projections to the rostral ventrolateral medulla (RVLM), an area important for cardiorespiratory reflexes and homeostasis. Since the net reflex effect of nTS processing ultimately depends on the properties of output neurons, we determined the characteristics of these RVLM-projecting nTS neurons using electrophysiological and immunohistochemical techniques. RVLM-projecting nTS neurons were identified by retrograde tracers. Patch clamp analysis in the horizontal brainstem nTS slice demonstrated that RVLM-projecting nTS cells exhibit constant latency solitary tract evoked excitatory postsynaptic currents (EPSCs), suggesting they receive strong monosynaptic contacts from visceral afferents. Three distinct patterns of action potential firing, associated with different underlying potassium currents, were observed in RVLM-projecting cells. Following activation of the chemoreflex in conscious animals by 3 h of acute hypoxia, 11.2+/-1.9% of the RVLM-projecting nTS neurons were activated, as indicated by positive Fos-immunoreactivity. Very few RVLM-projecting nTS cells were catecholaminergic. Taken together, these data suggest that RVLM projecting nTS neurons receive strong monosynaptic inputs from sensory afferents and a subpopulation participates in the chemoreflex pathway.


Assuntos
Vias Aferentes/fisiologia , Bulbo/fisiologia , Neurônios/fisiologia , Potenciais de Ação , Corpo Carotídeo/fisiologia , Catecolaminas/metabolismo , Hipóxia Celular , Membrana Celular/fisiologia , Potenciais Pós-Sinápticos Excitadores , Imuno-Histoquímica , Técnicas In Vitro , Canais de Potássio/fisiologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Núcleo Solitário/citologia , Núcleo Solitário/fisiologia
14.
Biomicrofluidics ; 1(2): 21502, 2007 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-19693375

RESUMO

The extension of microfluidic devices to three dimensions requires innovative methods to interface fluidic layers. Externally controllable interconnects employing nanocapillary array membranes (NCAMs) have been exploited to produce hybrid three-dimensional fluidic architectures capable of performing linked sequential chemical manipulations of great power and utility. Because the solution Debye length, kappa(-1), is of the order of the channel diameter, a, in the nanopores, fluidic transfer is controlled through applied bias, polarity and density of the immobile nanopore surface charge, solution ionic strength and the impedance of the nanopore relative to the microfluidic channels. Analyte transport between vertically separated microchannels can be saturated at two stable transfer levels, corresponding to reverse and forward bias. These NCAM-mediated integrated microfluidic architectures have been used to achieve highly reproducible and tunable injections down to attoliter volumes, sample stacking for preconcentration, preparative analyte band collection from an electrophoretic separation, and an actively-tunable size-dependent transport in hybrid structures with grafted polymers displaying thermally-regulated swelling behavior. The synthetic elaboration of the nanopore interior has also been used to great effect to realize molecular separations of high efficiency. All of these manipulations depend critically on the transport properties of individual nanocapillaries, and the study of transport in single nanopores has recently attracted significant attention. Both computation and experimental studies have utilized single nanopores as test beds to understand the fundamental chemical and physical properties of chemistry and fluid flow at nanometer length scales.

15.
Analyst ; 118(10): 1269-75, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8273910

RESUMO

A rapid, simple method for screening polychlorinated dibenzo-p-dioxin and dibenzofuran classes in shellfish tissue at pg g-1 wet mass concentrations is described. The method does not require a clean room facility and is based on saponification followed by extraction into hexane, clean-up using gel-permeation chromatography and sulfuric acid treatment, and measurement using capillary gas chromatography-low resolution mass spectrometry with selected ion monitoring. Selected ion monitoring using multiple ions eliminates interferences not removed by clean-up or chromatography. The detector response factor is constant for isomers within a class, e.g., tetrachlorodibenzo-p-dioxin isomers gave a mean response of 0.977 +/- 0.075 area counts fg-1, but varied significantly between classes. Thus one isomer serves as a 'standard' for all members of its class. Recoveries of added polychlorinated dibenzo-p-dioxins and dibenzofurans (20-500 pg g-1 wet mass) averaged 95.6 +/- 6.9 and 99.0 +/- 5.7%, respectively. The limits of detection (five times the noise level) are 20 pg g-1 tetrachlorodibenzo-p-dioxins and dibenzofurans, 20 pg g-1 pentachlorodibenzo-p-dioxins and dibenzofurans, 40 pg g-1 hexachlorodibenzo-p-dioxins and dibenzofurans, 40 pg g-1 heptachlorodibenzo-p-dioxins and dibenzofurans, and 100 pg g-1 octachlorodibenzo-p-dioxin and dibenzofuran. Above the limits of detection, the method gave results for polychlorinated dibenzo-p-dioxin and dibenzofuran classes in shellfish tissue comparable to those obtained by gas chromatography-high resolution mass spectrometry.


Assuntos
Benzofuranos/análise , Dioxinas/análise , Hidrocarbonetos Clorados/análise , Frutos do Mar/análise , Animais
16.
Experientia ; 32(12): 1538-40, 1976 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-1021442

RESUMO

Preweaning malnutrition permanently reduced brain size and cellular content but in spite of changes in the adrenocotical stress response no learning deficit was observed. Differential rearing environments did not influence the effects of malnutrition.


Assuntos
Encéfalo/crescimento & desenvolvimento , Aprendizagem , Distúrbios Nutricionais , Meio Social , Animais , Peso Corporal , Encéfalo/metabolismo , Corticosterona/sangue , DNA/metabolismo , Eletrochoque , Feminino , Masculino , Troca Materno-Fetal , Proteínas do Tecido Nervoso/metabolismo , Distúrbios Nutricionais/metabolismo , Distúrbios Nutricionais/fisiopatologia , Tamanho do Órgão , Gravidez , Ratos , Estresse Fisiológico/sangue
17.
Infect Control ; 4(3): 153-7, 1983.
Artigo em Inglês | MEDLINE | ID: mdl-6553024

RESUMO

An increased incidence in nafcillin (semisynthetic penicillins) resistant Staphylococcus aureus (SR-SA), which peaked in January 1980, was noted in Columbus Children's Hospital (CCH), Columbus, Ohio. To investigate the source of this outbreak, we reviewed the susceptibility patterns of S. aureus strains isolated at CCH for a 12-month period (July 1979 to June 1980). A total of 773 isolates from 706 patients were investigated with a total of 40 patients colonized or infected with SR-SA, approximately 25% of which were diagnosed in the ambulatory clinics. These patients did not have any apparent previous contact with the inpatient unit or inpatient personnel. Eight nosocomial infections were also uncovered. The first appeared in December 1979. Our studies suggested that some SR-SA isolates may have originated in the community and these organisms may not be exclusive to the hospital environment, as was felt to be the case previously. We also determined that the baseline incidence for our hospital of SR-SA was approximately 2% of total S. aureus isolates. Only 35% of the SR-SA demonstrated resistance to multiple antibiotics. This report indicates that community and nosocomial S. aureus isolates should be monitored for nafcillin resistance. Vancomycin susceptibility should be tested on all isolates and reported for SR-SA in life-threatening infections.


Assuntos
Infecção Hospitalar/microbiologia , Surtos de Doenças/epidemiologia , Nafcilina/farmacologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Adolescente , Adulto , Criança , Pré-Escolar , Infecção Hospitalar/epidemiologia , Feminino , Humanos , Masculino , Resistência às Penicilinas , Infecções Estafilocócicas/epidemiologia , Fatores de Tempo
18.
Growth ; 39(4): 497-506, 1975 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1239402

RESUMO

The effect of protein restriction on fetal and placental growth was investigated. Pregnant rats were maintained on an isocaloric diet containing either 23% or 5% protein. The diet was imposed either from days 1-21 of gestation or from days 7-21 of gestation. Fetal body development was assessed. Fetal brain and placental growth were determined by both analysis of organ DNA, RNA and protein and differential radiochemical labelling procedures. Maternal protein restriction inhibited fetal growth. Brain weight was reduced due to a significant decrease in cellular content. Brain cell size was significantly increased and may have accounted for the reduction in cell concentration. Placental growth was similarly impaired. These data demonstrate impaired fetal and placental growth following decreased maternal dietary protein intake. Severity of growth retardation increased with the duration of malnutrition. The results also suggest that malnutrition may affect the rate of development, causing premature cessation of cell division and early cell differentiation.


Assuntos
Encéfalo/crescimento & desenvolvimento , Feto , Placenta/fisiologia , Complicações na Gravidez , Deficiência de Proteína , Animais , Peso Corporal , Química Encefálica , DNA/análise , Feminino , Crescimento , Proteínas do Tecido Nervoso/análise , Gravidez , RNA/análise , Ratos
19.
Mol Ecol ; 8(12 Suppl 1): S65-78, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10703552

RESUMO

A nucleotide sequence analysis of the first internal transcribed spacer region (ITS-1) between the 5.8S and 18S ribosomal DNA genes (640 bp) and cytochrome c oxidase subunit I (COI) of mitochondrial DNA (mtDNA) (576 bp) was conducted for the freshwater bivalve Lasmigona subviridis and three congeners to determine the utility of these regions in identifying phylogeographic and phylogenetic structure. Sequence analysis of the ITS-1 region indicated a zone of discontinuity in the genetic population structure between a group of L. subviridis populations inhabiting the Susquehanna and Potomac Rivers and more southern populations. Moreover, haplotype patterns resulting from variation in the COI region suggested an absence of gene exchange between tributaries within two different river drainages, as well as between adjacent rivers systems. The authors recommend that the northern and southern populations, which are reproductively isolated and constitute evolutionarily significant lineages, be managed as separate conservation units. Results from the COI region suggest that, in some cases, unionid relocations should be avoided between tributaries of the same drainage because these populations may have been reproductively isolated for thousands of generations. Therefore, unionid bivalves distributed among discontinuous habitats (e.g. Atlantic slope drainages) potentially should be considered evolutionarily distinct. The DNA sequence divergences observed in the nuclear and mtDNA regions among the Lasmigona species were congruent, although the level of divergence in the COI region was up to three times greater. The genus Lasmigona, as represented by the four species surveyed in this study, may not be monophyletic.


Assuntos
Bivalves/genética , Animais , Sequência de Bases , Conservação dos Recursos Naturais , Primers do DNA/genética , DNA Mitocondrial/genética , Variação Genética , Genética Populacional , Haplótipos , Mid-Atlantic Region , Filogenia
20.
Mol Ecol ; 10(4): 807-21, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11348491

RESUMO

Atlantic salmon (n = 1682) from 27 anadromous river populations and two nonanadromous strains ranging from south-central Maine, USA to northern Spain were genotyped at 12 microsatellite DNA loci. This suite of moderate to highly polymorphic loci revealed 266 alleles (5-37/locus) range-wide. Statistically significant allelic and genotypic heterogeneity was observed across loci between all but one pairwise comparison. Significant isolation by distance was found within and between North American and European populations, indicating reduced gene flow at all geographical scales examined. North American Atlantic salmon populations had fewer alleles, fewer unique alleles (though at a higher frequency) and a shallower phylogenetic structure than European Atlantic salmon populations. We believe these characteristics result from the differing glacial histories of the two continents, as the North American range of Atlantic salmon was glaciated more recently and more uniformly than the European range. Genotypic assignment tests based on maximum-likelihood provided 100% correct classification to continent of origin and averaged nearly 83% correct classification to province of origin across continents. This multilocus method, which may be enhanced with additional polymorphic loci, provides fishery managers the highest degree of correct assignment to management unit of any technique currently available.


Assuntos
Variação Genética , Genética Populacional , Repetições de Microssatélites/genética , Salmo salar/genética , Alelos , Animais , Genótipo , Geografia , Funções Verossimilhança , Filogenia , Análise de Regressão , Salmo salar/classificação
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