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1.
Vet J ; 303: 106056, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38092176

RESUMO

A lumbosacral transitional vertebra (LTV) is a congenital anomaly of the spine and has been suggested to predispose to canine hip dysplasia (CHD). This retrospective, cross-sectional study investigated the prevalence of LTV and CHD among 14 dog breeds in Norway, the possible associations with risk factors, and whether LTV was a risk factor for the development of hip dysplasia. The results were based on evaluation of ventrodorsal radiographs from the CHD screening program from the Norwegian Kennel Club from February 2014 to January 2022. A total of 13,950 dogs were included in the study. For statistical analysis, CHD grades were reclassified from the official Federation Cynologique Internationale (FCI) grades into three grades: CHD free (CHD=A, B), CHD mild (CHD=C), and CHD severe (CHD=D, E). In the study sample, the overall occurrence of LTV was 18.5%, of which 32.9% were type 1, 45.7% type 2% and 21.4% type 3. The occurrence of LTV varied significantly among the included breeds, ranging from 9.5% to 46.2%. There was no association between sex and LTV. The frequencies of CHD grades were A: 43.1%; B: 31.4%; C: 18.4%; D: 6.0%; E: 1.1%. There was a statistically significant association with mild and severe CHD in dogs with LTV type 2 and LTV type 3 (P< 0.001). In the population studied, the prevalence of LTV was different among breeds. This supports initial data on the heredity of LTV and the diverse occurrence of LTV among breeds. Our results indicate that LTV type 2 and type 3 are associated with mild and severe CHD development. Therefore, this study has potentially identified an additional risk factor for the development of hip dysplasia.


Assuntos
Doenças do Cão , Luxação do Quadril , Displasia Pélvica Canina , Animais , Cães , Luxação do Quadril/complicações , Luxação do Quadril/veterinária , Estudos Retrospectivos , Estudos Transversais , Displasia Pélvica Canina/diagnóstico por imagem , Displasia Pélvica Canina/epidemiologia , Displasia Pélvica Canina/genética , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/anormalidades , Fatores de Risco , Noruega/epidemiologia , Doenças do Cão/diagnóstico por imagem , Doenças do Cão/epidemiologia , Doenças do Cão/genética
2.
J Anal Toxicol ; 47(4): e44-e47, 2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-36847150

RESUMO

Gamma-hydroxybutyrate (GHB) is a central nervous system depressant that has gained popularity as an illicit recreational drug. We describe a case of an elderly woman who was found unconscious in her home. The paramedics initially suspected an intracranial incident. A head computed tomography was negative, as was the initial urinary drug screening. The diagnosis of GHB intoxication was made with the detection of GHB in a urine sample obtained 28-29 hours after the assumed time of intake. Our case underscores the importance of considering drug testing in a broad range of patients and shows that elderly patients may have an extended detection window of GHB.


Assuntos
Depressores do Sistema Nervoso Central , Drogas Ilícitas , Oxibato de Sódio , Humanos , Feminino , Idoso , Oxibato de Sódio/urina , Drogas Ilícitas/urina , Detecção do Abuso de Substâncias/métodos
3.
Ultramicroscopy ; 160: 140-145, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26495808

RESUMO

A software method has been developed which uses ellipse fitting to analyse electron diffraction patterns from polycrystalline materials. The method, which requires minimal user input, can determine the pattern centre and the diameter of diffraction rings with sub-pixel precision. This enables accurate crystallographic information to be obtained in a rapid and consistent manner. Since the method fits ellipses, it can detect, quantify and correct any elliptical distortion introduced by the imaging system. Distortion information derived from polycrystalline patterns as a function of camera length can be subsequently recalled and applied to single crystal patterns, resulting in improved precision and accuracy. The method has been implemented as a plugin for the DigitalMicrograph software by Gatan, and is a freely available via the internet.

4.
Nano Lett ; 13(10): 4902-7, 2013 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-24059439

RESUMO

Doping of graphene via low energy ion implantation could open possibilities for fabrication of nanometer-scale patterned graphene-based devices as well as for graphene functionalization compatible with large-scale integrated semiconductor technology. Using advanced electron microscopy/spectroscopy methods, we show for the first time directly that graphene can be doped with B and N via ion implantation and that the retention is in good agreement with predictions from calculation-based literature values. Atomic resolution high-angle dark field imaging (HAADF) combined with single-atom electron energy loss (EEL) spectroscopy reveals that for sufficiently low implantation energies ions are predominantly substitutionally incorporated into the graphene lattice with a very small fraction residing in defect-related sites.


Assuntos
Grafite/química , Nanoestruturas , Semicondutores , Íons/química , Microscopia Eletrônica , Propriedades de Superfície
5.
IEEE Trans Neural Syst Rehabil Eng ; 21(3): 500-7, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23475375

RESUMO

Tactile sensation is critical for effective object manipulation, but current prosthetic upper limbs make no provision for delivering somesthetic feedback to the user. For individuals who require use of prosthetic limbs, this lack of feedback transforms a mundane task into one that requires extreme concentration and effort. Although vibrotactile motors and sensory substitution devices can be used to convey gross sensations, a direct neural interface is required to provide detailed and intuitive sensory feedback. In light of this, we describe the implementation of a somatosensory prosthesis with which we elicit, through intracortical microstimulation (ICMS), percepts whose magnitude is graded according to the force exerted on the prosthetic finger. Specifically, the prosthesis consists of a sensorized finger, the force output of which is converted into a regime of ICMS delivered to primary somatosensory cortex through chronically implanted multi-electrode arrays. We show that the performance of animals (Rhesus macaques) on a tactile task is equivalent whether stimuli are delivered to the native finger or to the prosthetic finger.


Assuntos
Membros Artificiais , Estimulação Encefálica Profunda/instrumentação , Potenciais Somatossensoriais Evocados , Dedos , Robótica/instrumentação , Tato , Transdutores , Animais , Comportamento Animal , Biorretroalimentação Psicológica/instrumentação , Biorretroalimentação Psicológica/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Macaca mulatta , Masculino , Movimento
7.
J Phys Condens Matter ; 20(6): 064238, 2008 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-21693899

RESUMO

A comprehensive density functional theory (DFT) study analysing the bulk and various low Miller index surfaces of Hägg Fe carbide (Fe(5)C(2)), considered to be the active phase in Fe-catalysed Fischer-Tropsch synthesis (FTS), has been carried out. The DFT determined bulk structure of Hägg Fe carbide (Fe(5)C(2)) is found to be in good agreement with reported monoclinic (C 2/c) XRD data, independently of whether a monoclinic (C 2/c) or triclinic ([Formula: see text]) bulk structure is used as input for calculations. Attention is focused on the construction of a surface energy stability trend with subsequent correlation with particular surface properties. It is found that a (010) Miller index plane results in the most stable surface (2.468 J m(-2)), while a (101) surface is the least stable (3.281 J m(-2)). The systematic comparison of calculated surface energies with surface properties such as the number of dangling bonds and surface atom density (within a broken bond model), as well as unrelaxed surface energies, relative ruggedness of surfaces, degree of surface relaxation upon optimization, total spin density changes of surfaces compared to the bulk, etc, result in only an approximate correlation with the surface stability trend in selected cases. From the results it is concluded that the relative surface energies fall in a narrow range and that a large number of additional surfaces may be defined, e.g. from higher Miller index planes, sharing similar surface energy values. The results serve to demonstrate the rich complexity and diverse nature of the Fe carbide phase responsible for FTS, effectively laying the foundation for further fundamental studies.

8.
Nanotechnology ; 19(49): 495605, 2008 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-21730680

RESUMO

Highly dense hexagonally ordered two-dimensional arrays of Si nanocrystals embedded in SiO(2) nanodots were fabricated on a silicon substrate by using a self-assembled porous anodic alumina thin film as a masking layer through which electrochemical oxidation of the Si substrate and ultralow energy Si implantation took place. After removal of the alumina film and high temperature annealing of the samples, hexagonally ordered Si nanocrystals embedded within SiO(2) nanodots were obtained, having sizes in the few tens of nanometer range. The fabricated ordered structures show significant potential for applications either in basic physics experiments or as building blocks for nanoelectronic and nanophotonic devices.

9.
J Neurophysiol ; 93(3): 1659-70, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15342724

RESUMO

We report on our efforts to establish an animal model for the development and testing of a cortical visual prostheses. One-hundred-fifty-two electrodes were implanted in the primary visual cortex of a rhesus monkey. The electrodes were made from iridium with an activated iridium oxide film, which has a large charge capacity for a given surface area, and insulated with parylene-C. One-hundred-fourteen electrodes were functional after implantation. The activity of small (2-3) neuronal clusters was first recorded to map the visually responsive region corresponding to each electrode. The animal was then trained in a memory (delayed) saccade task, first with a visual target, then to a target defined by direct cortical stimulation with coordinates specified by the stimulating electrode's mapped receptive field. The SD of saccade endpoints was approximately 2.5 larger for electrically stimulated versus visual saccades; nevertheless, when trial-to-trial scatter was averaged out, the correlation between saccade end points and receptive field locations was highly significant and approached unity after several months of training. Five electrodes were left unused until the monkey was fully trained; when these were introduced, the receptive field-saccade correlations were high on the first day of use (R = 0.85, P = 0.03 for angle, R = 0.98, P < 0.001 for eccentricity), indicating that the monkey had not learned to perform the task empirically by memorizing reward zones. The results of this experiment suggest the potential for rigorous behavioral testing of cortical visual prostheses in the macaque.


Assuntos
Mapeamento Encefálico , Eletrodos Implantados , Córtex Visual/anatomia & histologia , Córtex Visual/fisiologia , Animais , Comportamento Animal , Eletrodos Implantados/efeitos adversos , Eletrofisiologia , Lateralidade Funcional/fisiologia , Macaca mulatta , Masculino , Memória/fisiologia , Estimulação Luminosa/métodos , Movimentos Sacádicos/fisiologia , Coloração e Rotulagem/métodos , Campos Visuais/fisiologia , Percepção Visual/fisiologia
10.
J Obstet Gynecol Neonatal Nurs ; 30(4): 421-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11461026

RESUMO

A biopsychosocial-cultural model of the sexuality of women during the perimenopausal transition includes dimensions related to physiology, psychosocial issues, and culture. It is an amalgam of biomedical and psychosocial models, yet has the added focus on culture. This holistic approach to sexual health is recommended by researchers and clinicians engaged in the study of midlife women. Clinicians can use this model to guide assessment and interventions, examining all of the dimensions of sexuality during the perimenopausal transition.


Assuntos
Climatério/fisiologia , Climatério/psicologia , Modelos de Enfermagem , Sexualidade/fisiologia , Sexualidade/psicologia , Saúde da Mulher , Atitude Frente a Saúde/etnologia , Climatério/etnologia , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Saúde Holística , Humanos , Avaliação em Enfermagem , Planejamento de Assistência ao Paciente , Autoimagem , Sexualidade/etnologia , Valores Sociais
11.
Menopause ; 6(2): 105-14, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10374216

RESUMO

OBJECTIVE: The purpose of this study was to describe the perimenopausal symptom experience of Filipino American midlife women with particular emphasis upon estrogen-related menopause symptoms (day sweats, hot flashes, night sweats, and vaginal dryness). DESIGN: A cross-sectional, descriptive survey was used to generate symptom experience data for 165 Filipina Americans between the ages of 35 and 56 who self-identified as Filipina American and were English-language proficient. The community-based sample completed questionnaires composed of sample characteristic questions and a 51-item menstrual symptom checklist with menopause-related symptoms embedded in it. RESULTS: Sample characteristics and symptom experience were compared among age groups of 35 to 39 (n = 39), 40 to 44 (n = 40), 45 to 49 (n = 37), and 50 to 56 (n = 49) and by perimenopausal phase, defined as premenopausal (n = 85), transitional (n = 33), and menopausal/postmenopausal (n = 47). The most reported individual symptoms were "felt energetic" (86.1%) and "well-being" (83.6%). Estrogen-related menopause symptoms were reported as "vaginal dryness" (39.4%), "hot flashes" (37.6%), "day sweats" (27.9%), and "night sweats" (24.2%) by the total sample. Distress associated with estrogen-related menopause symptoms was reported by 17% (n = 28) of all women. Subjects' chi 2 tests indicated that 50-to-56-year-old women were more likely to report fatigue/sleep symptoms, physical symptoms, and estrogen-related menopause symptoms than all other age groups. When compared by perimenopausal phase, transitional women were more likely to report moderate or extreme severity for day sweats. Premenopausal women were more likely to report minimal or mild severity and women in the perimenopausal transition were more likely to report moderate or extreme severity on estrogen-related menopause symptoms. CONCLUSIONS: Filipino American midlife women appear to consider the perimenopausal transition in a positive light and experience little distress associated with estrogen-related menopause symptoms experienced. Findings from this study suggest that Filipina Americans view perimenopausal symptoms as part of a normal life stage that does not warrant concern.


Assuntos
Atitude Frente a Saúde , Menopausa/etnologia , Menopausa/fisiologia , Morbidade/tendências , Adaptação Fisiológica , Adulto , Distribuição por Idade , Análise por Conglomerados , Estudos Transversais , Características Culturais , Fadiga/epidemiologia , Fadiga/etiologia , Feminino , Inquéritos Epidemiológicos , Fogachos/epidemiologia , Fogachos/etiologia , Humanos , Incidência , Pessoa de Meia-Idade , Filipinas/etnologia , Pré-Menopausa/etnologia , Pré-Menopausa/fisiologia , Estados Unidos/epidemiologia , Doenças Vaginais/epidemiologia , Doenças Vaginais/etiologia
12.
Menopause ; 6(2): 115-21, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10374217

RESUMO

OBJECTIVE: The purpose of this study was to describe the perimenopausal symptom responses of Filipino American midlife women. DESIGN: This cross-sectional, descriptive survey collected symptom response information on Filipino American midlife women aged 35 to 56 years (n = 165) who self-identified as Filipina American and were proficient in the English language. Women were recruited from community churches and social groups. A survey questionnaire comprised of health history questions and a symptom checklist with symptom response questions were completed by the participants. RESULTS: The symptom responses of women were compared by age groups of 35 to 39 (n = 39), 40 to 44 (n = 40), 45 to 49 (n = 37), and 50 to 56 (n = 49) and by perimenopausal phases of premenopausal (n = 85), transitional (n = 33), and menopausal/postmenopausal (n = 47). Indications from chi 2 tests showed that women in the 35-to-39- and 50-to-56-year groups were more likely to take acetaminophen (Tylenol) or aspirin for symptoms, and women in the 45-to-49- and 50-to-56-year groups were more likely to be on hormone replacement therapy. Surprisingly, women in the 50-to-56-year group were less likely to use talking with friends as a symptom management strategy. CONCLUSIONS: Nonpharmacologic symptom management strategies exceeded the use of medications (hormones, over-the-counter) by Filipina Americans. This may be a strong indicator of their positive attitude toward this phase in their life and sends a message to clinicians about the choices that these women make for symptom management. Culturally relevant care would include alternatives to hormone replacement therapy in education materials about the perimenopausal transition for midlife Filipinas.


Assuntos
Atitude Frente a Saúde , Terapia de Reposição Hormonal/estatística & dados numéricos , Morbidade/tendências , Pré-Menopausa/etnologia , Pré-Menopausa/fisiologia , Adaptação Fisiológica , Adulto , Distribuição por Idade , Estudos Transversais , Características Culturais , Feminino , Inquéritos Epidemiológicos , Humanos , Pessoa de Meia-Idade , Filipinas/etnologia , Estados Unidos/epidemiologia
13.
Health Care Women Int ; 20(1): 81-92, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10335158

RESUMO

Although the perimenopausal transition is a universal experience for women who live long enough, its cross-cultural variations have been explored only recently. In this study, we investigated some of the expectations and health beliefs of 165 midlife Filipina Americans using focus groups and a short-answer questionnaire. Participants reported on (a) how they learned about menopause, (b) who they talked to about menopause symptoms or issues, (c) how Filipino women and men feel about menopause, and (d) the most common health complaints of midlife Filipinas. Findings revealed that midlife Filipina Americans primarily obtain their information from and talk about menopause with female relatives and friends. They usually viewed menopause as a normal life phase, yet knew less about how Filipino men feel about menopause. Health complaints of midlife Filipinas were mainly estrogen-related menopause symptoms and negative affect symptoms.


Assuntos
Atitude Frente a Saúde/etnologia , Educação em Saúde/métodos , Conhecimentos, Atitudes e Prática em Saúde , Nível de Saúde , Menopausa/etnologia , Mulheres/educação , Mulheres/psicologia , Adulto , California , Feminino , Grupos Focais , Humanos , Masculino , Homens/educação , Homens/psicologia , Pessoa de Meia-Idade , Pesquisa Metodológica em Enfermagem , Filipinas/etnologia , Inquéritos e Questionários
14.
Nurs Res ; 48(2): 71-7, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10190833

RESUMO

OBJECTIVES: To describe the biologic, psychological, social, and cultural (biopsychosociocultural) dimensions of the perimenopausal transition of Filipino American midlife women. METHODS: A community-based sample of 165 women (a) self-identified as Filipino American, (b) ages 35 to 56 years, and (c) English language proficient was recruited from churches and social groups. RESULTS: Women in the study were born in the Philippines (93.3%), had lived in the United States an average of 18.4 +/- 8.7 years, were married or partnered (74.6%), had completed college (62.8%) or a graduate degree (15.9%), worked (full-time, 77.9%; part-time, 12.9%), had household incomes greater than $50,000 (>58%). Menopause ages were calculated from reports of last menstrual periods (natural, 48.9 +/- 4.9 years; surgical, 42.2 +/- 5.7 years). Neither the age at menarche nor the number of pregnancies and children born was significantly related to age at menopause. Calcium from food sources was generally low, and the Center for Epidemiological Studies Depression Scale (CES-D) revealed a 24.8% depression rate. The low prevalence of physical health problems confirms previous research that foreign-born individuals have better health than those born in the United States. CONCLUSIONS: The profile of this understudied group identified calcium intake, osteoporosis morbidity, and prevalence of depression as key areas for future study.


Assuntos
Características Culturais , Pré-Menopausa/etnologia , Apoio Social , Adulto , Cálcio da Dieta/administração & dosagem , Estudos Transversais , Depressão , Escolaridade , Emigração e Imigração , Família , Feminino , Nível de Saúde , Humanos , Pessoa de Meia-Idade , Filipinas/etnologia , Pré-Menopausa/psicologia , Inquéritos e Questionários , Estados Unidos , Saúde da Mulher
15.
Health Care Women Int ; 20(3): 237-43, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10633622

RESUMO

Culture is an important variable in women's health research, and sample selection must include plans to recruit participants who represent the overall cultural makeup of the population. However, gaining access to underresearched groups is a major challenge and requires specific planning. Salient access techniques utilized by epidemiological researchers include (a) obtaining the support and endorsement of community leaders, (b) advertising the research in community publications, and (c) utilizing age, gender, and culturally matched research assistants. Although these elements were included in the planning of a study of the perimenopausal transition of Filipino American midlife women, the more powerful attractors for this particular cultural group were their pride in participating in a study that was associated with a major university and their intense community service orientation. Since each cultural group has unique issues and concerns, researchers must familiarize themselves with the values of their target group and emphasize these in recruitment approaches.


Assuntos
Atitude Frente a Saúde/etnologia , Área Carente de Assistência Médica , Pesquisa em Enfermagem/métodos , Seleção de Pacientes , Pré-Menopausa/etnologia , Saúde da Mulher , Mulheres/psicologia , Participação da Comunidade/psicologia , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Liderança , Filipinas/etnologia , Projetos de Pesquisa , Enfermagem Transcultural , Estados Unidos
17.
Protein Expr Purif ; 9(3): 319-30, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9126603

RESUMO

Retinoic acid receptors (RAR) are members of the steroid/thyroid hormone receptor superfamily and serve as ligand-activated transcription factors. In order to facilitate studies of receptor protein, we have generated a monoclonal antibody to the human RAR gamma, and have developed a procedure to purify the full-length receptor expressed in insect cells. The monoclonal antibody (A10) was developed using as antigen a carboxy-terminal fragment of the human RAR gamma expressed as a bacterial fusion protein. The A10 monoclonal antibody binds to both native and denatured forms of the human RAR gamma. This antibody was immobilized on a resin and used to purify full-length, baculovirus-expressed human RAR gamma to near homogeneity. The immunoaffinity-purified receptor is > 90-95% pure as revealed by silver-stained gels. The identity of the single protein band as RAR gamma was verified by immunoblotting using a polyclonal antibody to an epitope distinct from that recognized by the A10 antibody. The pure human RAR gamma is functional with respect to both ligand and DNA binding. Scatchard analysis of 3H-labeled all-trans retinoic acid binding to purified human RAR gamma revealed a single, high-affinity binding site with a Kd of approximately 2 nM. Binding of the pure RAR gamma to a DR5-type retinoic acid response element was also studied. Response element binding by RAR gamma required the presence of the retinoid X receptor, but did not require the presence of additional proteins. Human RAR gamma protein purified in this fashion will be useful in future structural and functional studies.


Assuntos
Receptores do Ácido Retinoico/isolamento & purificação , Animais , Anticorpos Monoclonais , Baculoviridae/genética , Sítios de Ligação , Cromatografia de Afinidade , Escherichia coli/genética , Humanos , Cinética , Camundongos , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Ratos , Receptores do Ácido Retinoico/genética , Receptores do Ácido Retinoico/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/isolamento & purificação , Spodoptera
18.
Yeast ; 11(8): 735-45, 1995 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-7668043

RESUMO

In the yeast Saccharomyces cerevisiae three dominant flocculation genes, FLO1, FLO5 and FLO8 have been described. Until now only the FLO1 gene, which is located at chromosome I, has been cloned and sequenced. FLO5 and FLO8 were previously localized at chromosomes I and VIII respectively (Vezinhet, F., Blondin, B. and Barre, P. (1991). Mapping of the FLO5 gene of Saccharomyces cerevisiae by transfer of a chromosome during cytoduction. Biotechnol. Lett. 13, 47-52; Yamashita, I. and Fukui, S. (1983). Mating signals control expression of both starch fermentation genes and a novel flocculation gene FLO8 in the yeast Saccharomyces. Agric. Biol. Chem. 47, 2889-2896). This was not in agreement with our results. Here, we report the location of FLO5 and FLO8 on chromosomes VIII and I respectively. By induced chromosome loss and genetic mapping, the FLO5 gene was localized at the right end of chromosome VIII approximately 34 cM centromere distal of PET3. This is part of the region that is present both at chromosome I and chromosome VIII. The location of FLO5 in this area of chromosome VIII made it necessary to re-evaluate the localization of FLO8, which was previously thought to occur in this region. Both genetic and physical mapping showed that FLO8 is allelic to FLO1. Hence, there are only two known dominant flocculation genes, FLO1 and FLO5. Analysis of the nucleotide sequence of chromosome VIII of a non-flocculent strain revealed an open reading frame encoding a putative protein that is approximately 96% identical to the Flo1 protein. This suggests that both dominant flocculation genes encode similar, cell wall-associated, proteins with the same function in the flocculation mechanism.


Assuntos
Mapeamento Cromossômico , Proteínas Fúngicas/genética , Genes Fúngicos , Proteínas de Membrana/genética , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Floculação , Lectinas de Ligação a Manose
19.
Yeast ; 11(5): 435-46, 1995 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-7597847

RESUMO

Northern analysis showed that DNA from the flocculation gene FLO1 hybridized to mRNA molecules of 4.8 kb. This transcript was specific for the FLO1 gene at the right end of chromosome I since disruption of this gene resulted in the disappearance of the transcript. We further found an absolute correlation between flocculation and the presence of transcripts hybridizing to FLO1 DNA, both in various flocculent and non-flocculent strains and in cells from the non-flocculating and flocculating stages of growth. In all cases transcripts were present in flocculating and absent from non-flocculating cultures. From these results we conclude that the FLO1 gene is transcriptionally regulated. Mutations in TUP1 or SSN6 cause flocculation. Several transcripts hybridizing to FLO1 DNA were present in the mutants but not in the corresponding wild-type strains. Disruption of the FLO1 gene in the tup1 and ssn6 strains showed that one of the transcripts corresponded to the FLO1 gene. Disruption of FLO1 did not abolish flocculation completely but only reduced it, indicating that at least two flocculation genes, including FLO1, are activated or derepressed by mutations in the TUP1/SSN6 regulatory cascade.


Assuntos
Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Proteínas de Membrana/genética , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Transcrição Gênica , Floculação , Lectinas de Ligação a Manose
20.
Mol Gen Genet ; 243(3): 325-33, 1994 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-8190085

RESUMO

The centromere of Kluyveromyces lactis was delimited to a region of approximately 280 bp, encompassing KlCDEI, II, and III. Removal of 6 bp from the right side of KlCDEIII plus flanking sequences abolished centromere function, and removal of 5 bp of KlCDEI and flanking sequences resulted in strongly reduced centromere function. Deletions of 20-80 bp from KlCDEII resulted in a decrease in plasmid stability, indicating that KlCDEII must have a certain length for proper centromere function. Centromeres of K. lactis do not function in Saccharomyces cerevisiae and vice versa. Adapting the length of KlCDEII to that of ScCDEII did not improve KlCEN function in S. cerevisiae, while doubling the ScCDEII length did not improve ScCEN function in K. lactis. Thus the difference in CDEII length is not in itself responsible for the species specificity of the centromeres from each of the two species of budding yeast. A chimeric K. lactis centromere with ScCDEIII instead of KlCDEIII was no longer functional in K. lactis, but did improve plasmid stability in S. cerevisiae, although to a much lower level than a wild-type ScCEN. This indicates that the exact CDEIII sequence is important, and suggests that the flanking AT-rich CDEII has to conform to specific sequence requirements.


Assuntos
Centrômero/fisiologia , DNA Fúngico/genética , Kluyveromyces/genética , Saccharomyces cerevisiae/genética , Sequência de Bases , Análise Mutacional de DNA , Dados de Sequência Molecular , Especificidade da Espécie
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