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1.
Bioinformatics ; 32(8): 1232-4, 2016 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-26704598

RESUMO

MOTIVATION: RNA interference (RNAi) technology is being developed as a weapon for pest insect control. To maximize the specificity that such an approach affords we have developed a bioinformatic web tool that searches the ever-growing arthropod transcriptome databases so that pest-specific RNAi sequences can be identified. This will help technology developers finesse the design of RNAi sequences and suggests which non-target species should be assessed in the risk assessment process. AVAILABILITY AND IMPLEMENTATION: http://rnai.specifly.org CONTACT: crobin@unimelb.edu.au.


Assuntos
Bases de Dados Genéticas , Internet , Interferência de RNA , Transcriptoma , Animais , Biologia Computacional , Insetos , Medição de Risco , Especificidade da Espécie
2.
Pharmacopsychiatry ; 46(3): 94-107, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23293011

RESUMO

INTRODUCTION: Buprenorphine is well known in the treatment of opioid dependence. Despite a high safety profile and good tolerance buprenorphine has been subject to misuse and diversion. To reduce misuse the antagonist naloxone was added and the 4:1 combination of buprenorphine-naloxone was launched in Germany in March 2007. On the basis of the results from international clinical trials a non-interventional study was conducted to gather data on safety, effectiveness, retention and acceptability of buprenorphine-naloxone in the treatment of opioid dependent patients in routine care. METHODS: A nationwide multicentre 12-month prospective, non-interventional, post-marketing, surveillance study was carried out with 12 assessment points in N=384 opioid dependent patients currently in maintenance treatment from N=69 general practitioners, clinics and outpatient clinics in Germany. RESULTS: N=337 data sets were eligible for analysis. The rates of patients with serious and non-serious adverse events were low with 1.2% and 17.5%, respectively. No deaths occurred during the observational period and only one hospitalization was documented. Concomitant drug use decreased for all illicit substances. Mental health and quality of life measured with standardized self-assessment questionnaires improved significantly. The 12-month retention rate was 57.1%. Of the n=181 patients still in treatment at the end of the observation period, 96.7% continued treatment with buprenorphine-naloxone. CONCLUSION: The findings of the non-interventional study indicate high effectiveness and safety of buprenorphine-naloxone in the treatment of opioid dependence. The medication was well accepted by opioid dependent patients in long-term substitution treatment with substantial reductions of concomitant drug use and measurable improvement in quality of life.


Assuntos
Buprenorfina/uso terapêutico , Naloxona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Adulto , Bases de Dados Bibliográficas/estatística & dados numéricos , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Observação , Vigilância de Produtos Comercializados , Estudos Prospectivos , Autoavaliação (Psicologia) , Inquéritos e Questionários
3.
Eur J Med Res ; 16(10): 427-36, 2011 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-22024421

RESUMO

OBJECTIVE: To assess efficacy, adherence and tolerability of once daily antiretroviral therapy containing tenofovir disoproxil fumarate (DF) 300 mg in HIV-1-infected former injecting drug users receiving opiate treatment (IVDU). METHODS: European, 48-week, open-label, single-arm, multicenter study. Patients were either antiretroviral therapy-naive, restarting therapy after treatment discontinuation without prior virological failure or switching from existing stable treatment. RESULTS: Sixty-seven patients were enrolled in the study and 41 patients completed treatment. In the primary analysis (intent-to-treat missing=failure) at week 48, 34% of patients (23/67; 95% CI: 23%-47%) had plasma HIV-1 RNA <50 copies/mL. Using an intent-to-treat missing=excluded approach, the week 48 proportion of patients with plasma HIV-1 RNA <50 copies/mL increased to 56% (23/41; 95% CI: 40%-72%). Mean (standard deviation) increase from baseline in CD4+ cell count at week 48 was 176 (242) cells/mm(3). Although self-reported adherence appeared high, there were high levels of missing data and adherence results should be treated with caution. No new safety issues were identified. CONCLUSIONS: Levels of missing data were high in this difficult-to-treat population, but potent antiretroviral suppression was achieved in a substantial proportion of HIV-infected IVDU-patients.


Assuntos
Adenina/análogos & derivados , Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Adesão à Medicação , Metadona/uso terapêutico , Organofosfonatos/uso terapêutico , Abuso de Substâncias por Via Intravenosa/tratamento farmacológico , Adenina/uso terapêutico , Adulto , Analgésicos Opioides/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Feminino , Seguimentos , Infecções por HIV/virologia , HIV-1/genética , HIV-1/patogenicidade , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Taxa de Sobrevida , Tenofovir , Resultado do Tratamento , Carga Viral , Adulto Jovem
4.
Eur J Med Res ; 15(3): 102-11, 2010 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-20452894

RESUMO

OBJECTIVE: This study was performed to investigate the impact of HAART versus no HAART and nucleoside free versus nucleoside containing HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV/HCV co-infected patients. In addition a control group of HCV mono-infected patients undergoing anti-HCV therapy was evaluated. METHODS: Multicenter, partially randomized, controlled clinical trial. HIV-negative and -positive patients with chronic HCV infection were treated with pegylated interferon alfa-2a and ribavirin (800 - 1200 mg/day) for 24 - 48 weeks in one of four treatment arms: HIV-negative (A), HIV-positive without HAART (B) and HIV-positive on HAART (C). Patients within arm C were randomized to receive open label either a nucleoside containing (C1) or a nucleoside free HAART (C2). RESULTS: 168 patients were available for analysis. By intent-to-treat analysis similar sustained virological response rates (SVR, negative HCV-RNA 24 weeks after the end of therapy) were observed comparing HIV-negative and -positive patients (54% vs. 54%, p = 1.000). Among HIV-positive patients SVR rates were similar between patients off and on HAART (57% vs. 52%, p = 0.708). Higher SVR rates were observed in patients on a nucleoside free HAART compared to patients on a nucleoside containing HAART, though confounding could not be ruled out and in the intent-to-treat analysis the difference was not statistically significant (64% vs. 46%, p = 0.209). CONCLUSIONS: Similar response rates for HCV therapy can be achieved in HIV-positive and -negative patients. Patients on nucleoside free HAART reached at least equal rates of sustained virological response compared to patients on standard HAART.


Assuntos
Terapia Antirretroviral de Alta Atividade , Antivirais/uso terapêutico , Infecções por HIV/tratamento farmacológico , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Adulto , Estudos de Casos e Controles , Portadores de Fármacos , Quimioterapia Combinada , Feminino , Infecções por HIV/complicações , Infecções por HIV/virologia , Hepacivirus/fisiologia , Hepatite C Crônica/complicações , Hepatite C Crônica/virologia , Humanos , Interferon alfa-2 , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Proteínas Recombinantes , Adulto Jovem
5.
Science ; 284(5411): 154-6, 1999 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-10102817

RESUMO

Leaves of higher plants develop in a sequential manner from the shoot apical meristem. Previously it was determined that perturbed leaf development in maize rough sheath2 (rs2) mutant plants results from ectopic expression of knotted1-like (knox) homeobox genes. Here, the rs2 gene sequence was found to be similar to the Antirrhinum PHANTASTICA (PHAN) gene sequence, which encodes a Myb-like transcription factor. RS2 and PHAN are both required to prevent the accumulation of knox gene products in maize and Antirrhinum leaves, respectively. However, rs2 and phan mutant phenotypes differ, highlighting fundamental differences in monocot and dicot leaf development programs.


Assuntos
Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Genes Homeobox , Proteínas de Homeodomínio/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Plantas/genética , Proteínas Proto-Oncogênicas c-myb , Proteínas Repressoras/genética , Zea mays/genética , Sequência de Aminoácidos , Clonagem Molecular , Proteínas de Ligação a DNA/química , Regulação para Baixo , Genes de Plantas , Proteínas de Homeodomínio/metabolismo , Hibridização In Situ , Dados de Sequência Molecular , Mutação , Fenótipo , Desenvolvimento Vegetal , Folhas de Planta/citologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/química , Plantas/metabolismo , Proteínas Repressoras/química , Proteínas Repressoras/fisiologia , Alinhamento de Sequência , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
6.
Eur J Med Res ; 14(7): 277-83, 2009 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-19661009

RESUMO

OBJECTIVE: To investigate if early treatment of primary HIV-1 infection (PHI) reduces viral set point and/or increases CD4 lymphocytes. METHODS: Analysis of two prospective multi-centre PHI cohorts. HIV-1 RNA and CD4 lymphocytes in patients with transient treatment were compared to those in untreated patients. Time to CD4 lymphocyte decrease below 350/ microl after treatment stop or seroconversion was calculated using Kaplan-Meier and Cox-PH-regression analyses. RESULTS: 156 cases of PHI were included, of which 100 had received transient HAART (median treatment time 9.5 months) and 56 remained untreated. Median viral load (563000 cop/ml vs 240000 cop/ml; p<0.001) and median CD4 lymphocyte (449/ microl vs. 613/ microl; p<0.01) differed significantly between treated and untreated patients. Median viral load was 38056 copies/ml in treated patients (12 months after treatment stop) and 52880 copies/ml in untreated patients (12 months after seroconversion; ns). Median CD4 lymphocyte change was +60/ microl vs. -86/ microl (p = 0.01). Median time until CD4 lymphocytes decreased to <350/ microl (including all patients with CD4 lymphocytes <500/ microl during seroconversion) was 20.7 months in treated patients after treatment stop and 8.3 months in untreated patents after seroconversion (p<0.01). Cox-PH analyses adjusting for baseline VL, CD4 lymphocytes, stage of early infection and symptoms confirmed these differences. CONCLUSIONS: Treatment during PHI did not lower viral set point. However, patients treated during seroconversion had an increase in CD4 lymphocytes, whereas untreated patients experienced a decrease in CD4 lymphocytes. Time until reaching CD4 lymphocytes <350/ microl was significantly shorter in untreated than in treated patients including patients with CD4 lymphocytes <500/ microl during seroconversion.


Assuntos
Terapia Antirretroviral de Alta Atividade/métodos , Contagem de Linfócito CD4 , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Adolescente , Adulto , Estudos de Coortes , Feminino , Infecções por HIV/imunologia , Infecções por HIV/virologia , Soropositividade para HIV/tratamento farmacológico , Soropositividade para HIV/imunologia , Soropositividade para HIV/virologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Avaliação de Resultados em Cuidados de Saúde/métodos , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Modelos de Riscos Proporcionais , Fatores de Tempo , Carga Viral , Adulto Jovem
7.
Curr Opin Genet Dev ; 5(5): 640-5, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8664552

RESUMO

Fertilization in flowering plants begins with a pollen grain bearing the male gametes landing on the female stigma. Several mechanisms enable the stigma to discriminate between the different types of pollen that it may receive, of which the best studied is self-incompatibility. The molecules that regulate self-incompatibility are well characterized in two plant families, the Solanaceae and Brassicaceae. This list has recently been extended to include candidates for self-incompatibility molecules from the Rosaceae, Papaveraceae and Poaceae. The information provided by the sequences of these molecules gives insight into the mechanisms and evolution of self-incompatibility in the different families of flowering plants.


Assuntos
Fenômenos Fisiológicos Vegetais , Fertilização , Genótipo , Modelos Biológicos , Proteínas de Plantas/metabolismo , Plantas/genética , Pólen/fisiologia , Ribonucleases/metabolismo , Especificidade da Espécie
8.
Curr Biol ; 9(22): R861-3, 1999 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-10574752
9.
Genetics ; 152(3): 1123-35, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10388830

RESUMO

Mutations affecting the self-incompatibility response of Nicotiana alata were generated by irradiation. Mutants in the M1 generation were selected on the basis of pollen tube growth through an otherwise incompatible pistil. Twelve of the 18 M1 plants obtained from the mutagenesis screen were self-compatible. Eleven self-compatible plants had mutations affecting only the pollen function of the S locus (pollen-part mutants). The remaining self-compatible plant had a mutation affecting only the style function of the S locus (style-part mutant). Cytological examination of the pollen-part mutant plants revealed that 8 had an extra chromosome (2n + 1) and 3 did not. The pollen-part mutation in 7 M1 plants was followed in a series of crosses. DNA blot analysis using probes for S-RNase genes (encoding the style function of the S locus) indicated that the pollen-part mutation was associated with an extra S allele in 4 M1 plants. In 3 of these plants, the extra S allele was located on the additional chromosome. There was no evidence of an extra S allele in the 3 remaining M1 plants. The breakdown of self-incompatibility in plants with an extra S allele is discussed with reference to current models of the molecular basis of self-incompatibility.


Assuntos
Mutação , Nicotiana/genética , Plantas Tóxicas , Pólen/genética , Cruzamentos Genéticos , Genótipo , Metáfase , Modelos Genéticos , Fenótipo , Pólen/citologia
10.
MMW Fortschr Med ; 147 Spec No 1: 60-2, 2005 Apr 25.
Artigo em Alemão | MEDLINE | ID: mdl-16385879

RESUMO

Despite an extensive addiction treatment and rehabilitation system for heroin addicts, inadequate infectious disease care still prevails for this group of patients. The reasons are structural in nature since both of the required medical disciplines (addiction medicine and infectious diseases epidemiology) are rarely found at one treatment location. Appropriate interdisciplinary cooperation must first be established. In a specialized heroin addiction treatment setting, patient compliance isjust as good as in other risk groups. Prerequisites for this good compliance are: Elimination of social and psychiatric disruptive factors, the selection of a medication regimen that takes secondary diseases and concomitant medication into consideration and the employment of once-daily treatment regimens or simple regimens with twice-daily dosages.


Assuntos
Terapia Antirretroviral de Alta Atividade , Infecções por HIV/reabilitação , Dependência de Heroína/reabilitação , Metadona/uso terapêutico , Entorpecentes/uso terapêutico , Abuso de Substâncias por Via Intravenosa/reabilitação , Infecções Oportunistas Relacionadas com a AIDS/reabilitação , Terapia Antirretroviral de Alta Atividade/efeitos adversos , Comorbidade , Relação Dose-Resposta a Droga , Esquema de Medicação , Interações Medicamentosas , Quimioterapia Combinada , Humanos , Metadona/efeitos adversos , Entorpecentes/efeitos adversos , Fatores de Risco
11.
Eur J Med Res ; 9(11): 491-504, 2004 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-15649858

RESUMO

The availability and application of effective antiretroviral combination therapies have now almost become routine. More than 20 antiretroviral substances in four classes have been approved. Although an almost incalculable number of combinations can be conceived, it must be stressed, that only a small number of the theoretically possible combinations are actually applicable. As a result of the broad therapeutic armamentarium, HIV infection can be better treated. However, the decisions to start, monitor and change therapy have become even more difficult because the indication for treatment, the selection of the most suitable therapy for an individual, the information and counselling of the patient, and the monitoring of the success of treatment all demand a high level of knowledge and experience. This guideline evaluates the indication and selection of the initial antiretroviral therapy for HIV infection.


Assuntos
Antirretrovirais/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Infecções por HIV/tratamento farmacológico , HIV-1 , Áustria , Alemanha , HIV-1/efeitos dos fármacos , Humanos
12.
Eur J Med Res ; 6(7): 317-21, 2001 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-11496900

RESUMO

Over the last years the reality surrounding HIV-infection has undergone a considerable change with regard to the life expectancy of patients, and the plans they can make for their lives. Because the majority of the HIV positive population is of reproductive age, one of these plans might be to have children, often as an expression of a fulfilled partnership. The need for medical support to realize this wish, however, is often confronted with ethical, medical or forensic restraints. For this reason, interdisciplinary recommendations have now been developed--for the first time on a global basis--which aim to provide guidelines for practitioners in this complicated area.


Assuntos
Infecções por HIV/diagnóstico , Infecções por HIV/terapia , Serviços de Planejamento Familiar , Feminino , Alemanha , Infecções por HIV/complicações , Infecções por HIV/transmissão , Humanos , Masculino , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/terapia , Parceiros Sexuais , Sociedades Médicas
13.
Forensic Sci Int ; 62(1-2): 95-9, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8300042

RESUMO

Drug addicts have, in general, a less complicated course of HIV infection than homosexual HIV patients. They show fewer opportunistic infections and tumors. But this advantage is lost by unnecessary complications due to their psychic disorders. Their non-compliance and concealment of signs of disease lead to worse outcomes of infections, which could be well-treated or prevented.


Assuntos
Infecções por HIV/complicações , Infecções por HIV/mortalidade , Homossexualidade , Abuso de Substâncias por Via Intravenosa/complicações , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/etiologia , Comorbidade , Mecanismos de Defesa , Infecções por HIV/psicologia , Infecções por HIV/terapia , Infecções por HIV/transmissão , Acessibilidade aos Serviços de Saúde , Humanos , Transtornos Mentais/epidemiologia , Transtornos Mentais/etiologia , Neoplasias/epidemiologia , Neoplasias/etiologia , Prognóstico , Resultado do Tratamento , Recusa do Paciente ao Tratamento
15.
Artigo em Alemão | MEDLINE | ID: mdl-17377723

RESUMO

Efficient prevention of HIV in drug users has had to overcome major political opposition in the last decade. Even today many evidence-based measures for the prevention of infections in drug users are still not being applied. Only a few preventive approaches are broadly carried out in the GFR: methadone maintenance performed by general practitioners, antiretroviral therapy and information about safer use given by AIDS- and drug-consultants and syringeexchange by pharmacies and at special institutions. In contrast, injection room facilities, street workers council, vaccination programs and low threshold medical treatment are only implemented in isolated cases. Nevertheless, HIV prevalence among drug users has been reduced successfully and the rate of new infections has decreased from 13.2% in 1994 to 9% in 2006. These strategies, however, do not seem to have any effect on the spread of hepatitis C among drug users. Here we still face a prevalence of 45-70%. Therefore, future research should focus on preventive measures against HCV infection of drug users.


Assuntos
Surtos de Doenças/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Promoção da Saúde/organização & administração , Abuso de Substâncias por Via Intravenosa/epidemiologia , Abuso de Substâncias por Via Intravenosa/prevenção & controle , Comorbidade , Atenção à Saúde/organização & administração , Alemanha/epidemiologia , Humanos , Incidência
16.
Schmerz ; 20(5): 445-57; quiz 458-9, 2006 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-16955296

RESUMO

Each individual is entitled to an adequate and sufficient pain therapy. However, only a few studies have examined the peculiarities of pain management in drug-dependent or formerly addicted patients. Any addiction is disadvantageous for a successful pain therapy, since some of the prescribed drugs may themselves cause addiction. Drug-dependent patients are often tolerant to opioids. Additionally, there is a risk of iatrogenic pain becoming chronic due to disregard for already known risk factors and comorbidities. However, a history of addiction should not prevent sufficient pain therapy, especially since there is no risk of addiction when the pain therapy employed is adequate for the pathophysiology involved. There are adequate pain therapies for addicted patients. The best results are achieved by taking into account the physiological and psychological peculiarities of drug-dependent patients. Importantly, this should be combined with a variety of different, optimized, multimodal therapeutic regimes, as well as with an interdisciplinary approach.


Assuntos
Analgésicos não Narcóticos/uso terapêutico , Analgésicos Opioides/uso terapêutico , Manejo da Dor , Transtornos Relacionados ao Uso de Substâncias/complicações , Terapia por Acupuntura , Doença Aguda , Anestesia por Condução , Consenso , Tolerância a Medicamentos , Seguimentos , Humanos , Comunicação Interdisciplinar , Morfina/uso terapêutico , Dor/tratamento farmacológico , Psicoterapia , Fatores de Risco , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/etiologia , Estimulação Elétrica Nervosa Transcutânea , Organização Mundial da Saúde
17.
Z Arztl Fortbild (Jena) ; 90(4): 271-8, 1996 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-8928526

RESUMO

The treatment and counseling of drug addicts increasingly comes under the responsibility of family physicians. Since the onset of the AIDS epidemic this applies in particular to the methadone treatment of chronically ill heroin addicts. Medical education concerning the treatment of addiction is insufficient. Unprofessional dealing with drug addicts may easily result in serious obstruction of the relation between physician and patient. Thus it endangers the success of treatment. Basic guidelines of interaction, possibilities of abstinence therapy as well as harm reducing strategies are presented.


Assuntos
Assistência Ambulatorial , Drogas Ilícitas , Psicotrópicos , Transtornos Relacionados ao Uso de Substâncias/reabilitação , Dependência de Heroína/psicologia , Dependência de Heroína/reabilitação , Humanos , Metadona/uso terapêutico , Naloxona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Relações Médico-Paciente , Atenção Primária à Saúde , Transtornos Relacionados ao Uso de Substâncias/psicologia , Resultado do Tratamento
18.
Plant J ; 16(5): 591-9, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10036777

RESUMO

We surveyed ribonuclease activity in the styles of Nicotiana spp. and found little or no activity in self-compatible species and in a self-compatible accession of a self-incompatible species. All self-incompatible species had high levels of ribonuclease activity in their style. Interestingly, one self-compatible species, N. sylvestris, had a level of stylar ribonuclease activity comparable to that of some self-incompatible Nicotiana species. A ribonuclease with biochemical properties similar to those of the self-incompatibility (S-)RNases of N. alata was purified from N. sylvestris styles. The N-terminal sequence of this protein was used to confirm the identity of a cDNA corresponding to the stylar RNase. The amino acid sequence deduced from the cDNA was related to those of the S-RNases and included the five conserved regions characteristic of these proteins. It appears that the N. sylvestris RNase may have evolved from the S-RNases and is an example of a 'relic S-RNase'. A number of features distinguish the N. sylvestris RNase from the S-RNases, and the role these may have played in the presumed loss of the self-incompatibility response during the evolution of this species are discussed.


Assuntos
Nicotiana/enzimologia , Nicotiana/genética , Plantas Tóxicas , Ribonucleases/genética , Amidoidrolases/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Primers do DNA/genética , DNA Complementar/genética , DNA de Plantas/genética , Evolução Molecular , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Hidrólise , Dados de Sequência Molecular , Peptídeo-N4-(N-acetil-beta-glucosaminil) Asparagina Amidase , Especificidade da Espécie
19.
Proc Natl Acad Sci U S A ; 98(26): 15372-6, 2001 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-11752474

RESUMO

Self-incompatibility (SI) is a genetic mechanism that restricts inbreeding in flowering plants. In the nightshade family (Solanaceae) SI is controlled by a single multiallelic S locus. Pollen rejection in this system requires the interaction of two S locus products: a stylar (S)-RNase and its pollen counterpart (pollen S). pollen S has not yet been cloned. Our understanding of how this gene functions comes from studies of plants with mutations that affect the pollen but not the stylar SI response (pollen-part mutations). These mutations are frequently associated with duplicated S alleles, but the absence of an obvious additional allele in some plants suggests pollen S can also be deleted. We studied Nicotiana alata plants with an additional S allele and show that duplication causes a pollen-part mutation in several different genetic backgrounds. Inheritance of the duplication was consistent with a competitive interaction model in which any two nonmatching S alleles cause a breakdown of SI when present in the same pollen grain. We also examined plants with presumed deletions of pollen S and found that they instead have duplications that included pollen S but not the S-RNase gene. This finding is consistent with a bipartite structure for the S locus. The absence of pollen S deletions in this study and perhaps other studies suggests that pollen S might be required for pollen viability, possibly because its product acts as an S-RNase inhibitor.


Assuntos
Glicoproteínas/genética , Mutação , Nicotiana/genética , Proteínas de Plantas/genética , Pólen/genética , Ribonucleases/antagonistas & inibidores , Alelos , Hibridização in Situ Fluorescente , Dados de Sequência Molecular
20.
Am J Community Psychol ; 23(3): 355-88, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7572836

RESUMO

Developed and validated instruments for urban and culturally diverse adolescents to assess their self-reported transactions with family, peer, school, and neighborhood microsystems for the constructs of social support, daily hassles, and involvement. The sample of 998 youth were from schools in three Eastern cities with high percentages of economically disadvantaged youth. Data were collected before and after the transition to junior high school or to senior high school. Blacks constituted 26%, whites 26%, and Latinos 37% of the sample. Factor analyses confirmed and enhanced the hypothesized four-factor microsystem factor structure for support, hassles, and involvement; internal consistency and stability coefficients were consistent with these structures. In general, the microsystem factors were common across gender, ethnicity, and age. However, when group differences did occur on these demographic variables, they tended to validate the salience of microsystem specificity. In contrast to the total scores, the microsystem-specific factors yielded more meaningful and differential information with regard to demographic differences and the mediating processes across a school transition.


Assuntos
Acontecimentos que Mudam a Vida , Psicologia do Adolescente , Apoio Social , Adolescente , Feminino , Humanos , Relações Interpessoais , Masculino , Reprodutibilidade dos Testes , Fatores Socioeconômicos
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