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1.
Neotrop Entomol ; 48(5): 729-738, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31089898

RESUMO

Wetlands are being increasingly affected by anthropogenic activities worldwide. The Lower Delta of the Paraná River, one of the most important wetlands in Argentina, has been profoundly altered because most of the natural environments were drained or diked to make them suitable for different agricultural activities. As a result, the landscape is characterized by a mosaic of Salicaceae afforestations of different ages interspersed with patches of secondary forests and grazing grasslands. The high susceptibility of Carabidae and Aphodiidae to natural and human-induced disturbances and management practices is reflected by changes in their spatiotemporal distribution. We performed a 1-year study to analyze and compare beetle's communities inhabiting different habitat types in this modified wetland landscape. A total of 58 beetle species were recorded, of which 48 were carabids and 10 aphodids. Although species richness and diversity were higher in productive habitats (afforestations and grasslands) than in secondary forests, hydrophilic species were only found in the latter. Community parameters varied seasonally. Our results indicate a close relationship between wetland beetle communities and vegetation cover in each habitat type. Human activity increases heterogeneity across this landscape, which favors the colonization of new species but causes the loss or displacement of autochthonous species. The secondary forests could serve as alternative habitats for beetles typical of humid environments. We propose the maintenance of the current heterogeneous mosaic to favor the diversity of ground beetles and the implementation of changes in water management for the benefit of hydrophilic beetle species.


Assuntos
Besouros , Áreas Alagadas , Animais , Argentina , Florestas , Rios , Água
4.
Arch Gerontol Geriatr ; 44 Suppl 1: 55-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17317434

RESUMO

Estimations indicate that a member of the family defined as caregiver nurses 80% of the patients affected by dementia in Italy at home. The term care giving refers to activities and experiences able to provide help and assistance to relatives or friends who are unable to live on their own. The aim of the study was to evaluate the impact of day-care center for patients affected by dementia and behavioral symptoms on burden perceived by caregiver. The introduction of a patient in a daily center results an effective support also for the family member who shows that the progressive awareness of the illness. Therefore, the taking care of all the problems linked to the role of caregiver is essential either to reduce the burden which lies on the welfare state and to realize a sort of "rehabilitation home" of the patient's cognitive behavioral and functional disorders. In this way, we could postpone as far as possible the institutionalization of the patient affected by dementia.


Assuntos
Cuidadores/psicologia , Efeitos Psicossociais da Doença , Hospital Dia , Demência/reabilitação , Família/psicologia , Idoso , Feminino , Humanos , Institucionalização , Masculino
5.
Int J Antimicrob Agents ; 28 Suppl 1: S49-63, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16854569

RESUMO

The definition of acute pyelonephritis is controversial. There are two contrasting approaches: (1) acute pyelonephritis is a severe infectious disease involving the kidney parenchyma, and specific imaging techniques are required for diagnosis; (2) acute pyelonephritis is a urinary tract infection, and diagnosis and therapy follow simplified clinical and laboratory pathways. In this study, recent randomized controlled trials (RCTs) were systematically reviewed and the diagnostic and therapeutic approaches to acute 'uncomplicated' pyelonephritis were analysed. Medline, Embase, Cochrane Central Register of Controlled Trials (CCTR) and Chinal were searched employing Mesh, Emtree and free terms on 'pyelonephritis'. Limits included human, period (1995-2004), and trials-reviews (where available). In total, 904 references and 175 full-text were retrieved; 29 were pertinent RCTs. Seven RCTs were added from reference lists (indexed on urinary tract infections). Imaging examinations were performed in 11 of 14 studies on children (diagnostic requisite in two) and in two studies on adults; scarring was not analysed in adults. Clinical definitions varied widely (fever >37.8 to >39 degrees C, culture titres 10(4) >10(5)). Studies on adults were limited to short-term end-points (microbiological sterilization, clinical improvement). Duration of therapy was 4-20 days. The trend was towards shorter periods of therapy, mainly on an outpatient basis; intravenous therapy, if performed, was usually limited to the first 1-3 days. For acute uncomplicated pyelonephritis, the tendency is towards 2 weeks of mainly oral antibiotic therapy. However, the recent literature on adults does not discriminate among different upper urinary tract infections nor does it provide data on renal scarring. While cost constraints point towards short-term therapies, further studies are needed to assess the prevalence and long-term effect of kidney scars.


Assuntos
Antibacterianos/uso terapêutico , Pielonefrite/tratamento farmacológico , Doença Aguda , Humanos , Pielonefrite/diagnóstico , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Resultado do Tratamento
6.
Int J Antimicrob Agents ; 28 Suppl 1: S64-71, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16854571

RESUMO

Acute pyelonephritis is a common complication of kidney transplantation, occurring in up to 1% of grafts. Diagnosis is mainly clinical and atypical presentations have seldom been reported. The diagnostic role of imaging techniques has not been defined. Five cases of acute graft pyelonephritis are reported (three kidney, two pancreas-kidney grafts). The patients (median age 48 years) comprised three females and two males. Median post-transplant follow-up was 3 months, with three patients having predisposing factors for diabetes and one for an enteric bladder. None of the patients presented the 'classic' diagnostic tetrad (i.e. fever, positive urine cultures, low urinary tract symptoms and serum creatinine increase); although, at diagnosis, two of five patients presented with fever, one had increased creatinine levels and one had positive urine cultures. Of note, three patients had leucocyte casts at urinary sediment analysis, thus raising clinical suspicion. Renal ultrasounds were negative in all patients. Renal (99m)Tc-MAG3 (mercaptoacetyltriglycine) scintigraphy, which was used for the definition of kidney function impairment (one patient) or because of the presence of urinary casts (three patients), or after the biopsy diagnosis to locate the parenchymal lesions (one patient), was positive in all patients. The presence and pyelonephritic origin of the parenchymal lesions was confirmed by nuclear magnetic resonance or computed tomography scans. Acute graft pyelonephritis may develop in the absence of a full-blown clinical picture. Smouldering symptoms may occur in the presence of large perfusion deficits. (99m)Tc-MAG3 scintigraphy could be an important diagnostic tool in such cases.


Assuntos
Diagnóstico por Imagem/métodos , Transplante de Rim/efeitos adversos , Pielonefrite/diagnóstico , Doença Aguda , Adulto , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Pielonefrite/diagnóstico por imagem , Cintilografia , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Mertiatida , Tomografia Computadorizada por Raios X , Ultrassonografia
7.
Transplant Proc ; 38(5): 1224-6, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16797269

RESUMO

BACKGROUND: Among the so-called social risk behaviors, male homosexuality is probably one of the most interesting and difficult taboos. Because of changing attitudes of the general population toward irregular sexual behaviors, often considered as markers of unhealthy life styles, there is a need to reconsider at least the most important one-homosexuality. METHODS: A semistructured questionnaire included opinions on homosexuality with respect to kidney donation: Would you consider a male homosexual as a kidney donor? If you were on dialysis, would you accept a kidney from a homosexual donor? This instrument was administered to various groups of the general public and caregivers: high school students (Liceo Classico: 59 students, median age 18 years; Istituto Tecnico: n=108, median age 17); first and fourth year of medical school (n=77, age 19; 46, age 22); continuing medical education (n=44, age 32); third year of nursing school (n=31, age 23); "senior citizen university" (n=51, age 63). RESULTS: Male homosexuality was well accepted for kidney donation (71.6% yes, 9.6% no, 18.8% uncertain/blank). However, the opinions were different among the groups with male students of a technical institute showing discrimination against male homosexuals. In the univariate analysis, opinions differed according to age, gender, and belonging to the health care team. In the multivariate analysis, the latter was the strongest predictor (P<.01). The specific threats for the health are not well known, even among the caregiver population. CONCLUSION: It is difficult to define the role of homosexuality among the so-called social risk behaviors. Negative attitudes existed in some subsets of the population.


Assuntos
Homossexualidade Masculina , Rim , Preconceito , Doadores de Tecidos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Adolescente , Adulto , Análise de Variância , Atitude , Estudos Transversais , Feminino , Humanos , Masculino , Tabu , Doadores de Tecidos/psicologia
8.
World J Urol ; 24(1): 66-73, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16429303

RESUMO

BACKGROUND: Acute pyelonephritis is a potential cause of kidney scars. AIM: To evaluate the relationship between clinical, laboratory and imaging data and the development of kidney scars in acute pyelonephritis. METHODS: All consecutive patients hospitalized for acute uncomplicated pyelonephritis in our nephrology unit from June 1996 to June 2004 were considered: 58 females, median age 25.6 years (16-52). Diagnosis of pyelonephritis required parenchymal lesions shown by CT or NMR scan. RESULTS: The lesions were bilateral in 17.2% (10/58) patients, unilateral, but multifocal in 81.0% (47/58); at CT or NMR, 65.5% of the lesions were classified as simple, 19% with tendency to colliquation and 15.5% abscessual. The median interval between first symptoms and diagnosis was 5 days (1-25); at referral, only 20.7% had a positive urine culture and 94.8% (55/58) had undergone previous antibiotic treatment. The therapeutic protocol required intravenous therapy for > or = 2 weeks, followed by 2-4 weeks of oral therapy. At 6-8 months, the prevalence of kidney scars was 29.3%. Their development was highly correlated with the type of lesions at diagnosis (highest risk with abscessual lesions; uni- and multivariate analysis). No other clinical or laboratory marker (age, fever, positive cultures, levels of acute phase reactants, interval between onset and diagnosis) was correlated with the outcome (scars). CONCLUSIONS: The type of lesion at diagnosis of acute uncomplicated pyelonephritis is highly correlated with the development of kidney scars. Further studies are needed to test the therapeutic schedules tailored according to the imaging data.


Assuntos
Cicatriz/diagnóstico , Espectroscopia de Ressonância Magnética/métodos , Pielonefrite/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Urina/microbiologia , Doença Aguda , Adolescente , Adulto , Anti-Infecciosos Urinários/administração & dosagem , Cicatriz/etiologia , Progressão da Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Seguimentos , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Probabilidade , Pielonefrite/complicações , Pielonefrite/tratamento farmacológico , Estudos Retrospectivos , Índice de Gravidade de Doença , Resultado do Tratamento
9.
Epidemiol Infect ; 130(1): 13-21, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12613741

RESUMO

Although the incidence of typhoid fever in the United States has been low since the 1940s, Salmonella Typhi continues to cause outbreaks. We reviewed reported outbreaks of typhoid fever from 1960 to 1999. There were 60 outbreaks; in 54, exposure occurred within the United States. These 54 outbreaks accounted for 957 total cases (median 10) and 4 deaths. In 36 (67%) outbreaks the route of transmission was identified, and in 16 (62%) of the 26 foodborne outbreaks an asymptomatic carrier was identified by culture or serology. The median incubation period was 2 weeks. Isolates from 10 (40%) of 25 outbreaks were phage type E1. The average frequency of outbreaks decreased from 1.85/year during 1960-79 to 0.85/year during 1980-99 (P=0.0001). S. Typhi outbreaks in the United States are generally small in size but can cause significant morbidity, and are often foodborne, warranting thorough investigation.


Assuntos
Surtos de Doenças , Febre Tifoide/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Tipagem de Bacteriófagos , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Salmonella typhi/isolamento & purificação , Estações do Ano , Febre Tifoide/etiologia , Febre Tifoide/transmissão , Estados Unidos/epidemiologia
10.
Mol Reprod Dev ; 60(1): 97-106, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11550273

RESUMO

We previously characterized a nuclease-hypersensitive fraction of mouse sperm chromatin, which is organized in a typical nucleosomal structure. A partial genomic library was constructed with the DNA from the nuclease-hypersensitive chromatin, which revealed a high content in retroposon/retroviral DNA sequences. Here we report that the cloned nuclease-hypersensitive DNA also contains clusters of potential sites for transcription factors: among those, binding sites for Oct-1, Oct-4, TBP, Ets-1, and C/EBP are most abundant. This observation prompted us to ask whether mature spermatozoa contain the corresponding protein factors. Indirect immunofluorescence experiments show that all analyzed factors are indeed present in the sperm heads. Moreover, transcription factors are associated with the nuclease-hypersensitive chromatin of spermatozoa, as endogenous nucleases that degrade the hypersensitive fraction also cause the concomitant release of transcription factors from sperm cells into the medium. Band-shift assays with proteins extracted from the supernatant, and immunofluorescence analysis of sperm pellets, indicate that transcription factors are largely recovered in the supernatant while being absent or poorly retained in spermatozoa. The possible involvement of these factors in early embryogenesis is discussed.


Assuntos
Cromatina/metabolismo , Espermatozoides/citologia , Espermatozoides/metabolismo , Fatores de Transcrição/metabolismo , Animais , Sequência de Bases , Sítios de Ligação , Cromatina/genética , DNA/genética , DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Eletroforese em Gel de Poliacrilamida , Regulação da Expressão Gênica , Masculino , Camundongos , Microscopia de Fluorescência , Transporte Proteico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
J Med Chem ; 44(20): 3329-33, 2001 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-11563932

RESUMO

A series of DNA-binding potential antitumor agents bearing a cationic carboxamide side chain attached in position peri to an electron-withdrawing atom, N-5,2-di(omega-aminoalkyl)-2,6-dihydropyrazolo[3,4,5-kl]acridine-5-carboxamides, has been prepared by reaction of the appropriate 1-chloro-9-oxo-9,10-dihydro-4-acridinecarboxamides with the suitable (omega-aminoalkyl)hydrazine. The noncovalent DNA-binding properties of these compounds have been examined using a fluorometric technique. In vitro cytotoxic potency of these derivatives toward the human colon adenocarcinoma cell line (HT29) is described and compared to that of reference drugs. Structure-activity relationships are discussed. Two highly DNA-affinic and potent cytotoxic compounds, 4m,o, have been identified as new leads in the antitumor strategies.


Assuntos
Acridinas/síntese química , Antineoplásicos/síntese química , DNA/química , Acridinas/química , Acridinas/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Fluorometria , Humanos , Relação Estrutura-Atividade , Células Tumorais Cultivadas
12.
Am J Physiol Heart Circ Physiol ; 280(3): H1145-50, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11179058

RESUMO

R-R interval variability (RR variability) is increasingly being used as an index of autonomic activity. High-frequency (HF) power reflects vagal modulation of the sinus node. Since vagal modulation occurs at the respiratory frequency, some investigators have suggested that HF power cannot be interpreted unless the breathing rate is controlled. We hypothesized that HF power during spontaneous breathing would not differ significantly from HF power during metronome-guided breathing. We measured HF power during spontaneous breathing in 20 healthy subjects and 19 patients with heart disease. Each subject's spontaneous breathing rate was determined, and the calculation of HF power was repeated with a metronome set to his or her average spontaneous breathing rate. There was no significant difference between the logarithm of HF power measured during spontaneous and metronome-guided breathing [4.88 +/- 0.29 vs. 5.29 +/- 0.30 ln(ms(2)), P = 0.32] in the group as a whole and when patients and healthy subjects were examined separately. We did observe a small (9.9%) decrease in HF power with increasing metronome-guided breathing rates (from 9 to 20 breaths/min). These data indicate that HF power during spontaneous and metronome-guided breathing differs at most by very small amounts. This variability is several logarithmic units less than the wide discrepancies observed between healthy subjects and cardiac patients with a heterogeneous group of cardiovascular disorders. In addition, HF power is relatively constant across the range of typical breathing rates. These data indicate that there is no need to control breathing rate to interpret HF power when RR variability (and specifically HF power) is used to identify high-risk cardiac patients.


Assuntos
Doença das Coronárias/diagnóstico , Doença das Coronárias/fisiopatologia , Frequência Cardíaca/fisiologia , Respiração , Nervo Vago/fisiologia , Adulto , Idoso , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nó Sinoatrial/inervação , Nó Sinoatrial/fisiologia
13.
Hepatology ; 33(2): 333-8, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11172334

RESUMO

Our aims were to develop a noninvasive predictive tool to identify cirrhotic patients with esophageal varices and to evaluate whether portal Doppler ultrasonographic parameters may improve the value of other predictors. One hundred forty-three consecutive compensated cirrhotic patients underwent upper gastrointestinal endoscopy. Fourteen clinical, biochemical, ultrasonographic, and Doppler ultrasonographic parameters of each patient were also recorded. Esophageal varices were detected in 63 of the 143 patients examined (44%; 95% confidence interval [CI] 36.2-52.6). Medium and large esophageal varices were observed in 28 subjects (44%; 95% CI 31.4-58.4). Using stepwise logistic regression, presence of esophageal varices was independently predicted by prothrombin activity less than 70% (odds ratio [OR]: 5.83; 95% CI: 2.6-12.8), ultrasonographic portal vein diameter greater than 13 mm (OR: 2.92; 95% CI: 1.3-6.4), and platelet count less than 100 x 10(9)/L (OR: 2.83; 95% CI: 1.27-6.28). Variables included in the model were used to generate a simple incremental rule to evaluate each individual patient. The discriminating ability of the prediction rule was relevant (area under the curve: 0.80) and did not change by replacing ultrasonographic portal vein diameter with congestion index of portal vein. We concluded that compensated cirrhotic patients should be screened by upper gastrointestinal endoscopy when prothrombin activity less than 70%, platelet count less than 100 x 10(9)/L, and ultrasonographic portal vein diameter greater than 13 mm are observed, whereas those without any of these predictors should not undergo endoscopy. The contribution provided by portal Doppler ultrasonographic parameters does not appear of practical utility.


Assuntos
Endoscopia do Sistema Digestório , Varizes Esofágicas e Gástricas/etiologia , Varizes Esofágicas e Gástricas/patologia , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Seleção de Pacientes , Idoso , Estudos Transversais , Feminino , Previsões , Humanos , Cirrose Hepática/sangue , Cirrose Hepática/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Contagem de Plaquetas , Veia Porta/diagnóstico por imagem , Protrombina/análise , Ultrassonografia Doppler
14.
Mech Dev ; 97(1-2): 211-5, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11025228

RESUMO

We have examined the murine genes encoding transcription factors E2F1, -3, -5 and -6 in gametes and early embryos. All genes are expressed as maternal transcripts and all are efficiently transcribed after the blastocyst stage. Between those two stages, each E2F mRNA is transcribed with a distinctive and unique pattern. E2F proteins are also differentially expressed and compartmentalized in pre-implantation embryos.


Assuntos
Proteínas de Transporte , Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Células Germinativas/metabolismo , Fatores de Transcrição/genética , Células 3T3 , Animais , Fatores de Transcrição E2F , Fator de Transcrição E2F1 , Fator de Transcrição E2F3 , Fator de Transcrição E2F5 , Fator de Transcrição E2F6 , Desenvolvimento Embrionário e Fetal , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína 1 de Ligação ao Retinoblastoma , Fator de Transcrição DP1
15.
Eur J Gastroenterol Hepatol ; 12(5): 529-33, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10833096

RESUMO

BACKGROUND: Portal hypertensive gastropathy (PHG) is frequently found among patients with hepatic cirrhosis and at present the only way to detect and follow PHG is via endoscopy. OBJECTIVE: To assess gastric and intestinal permeability and investigate its relationship to endoscopic findings and indices of portal hypertension and hepatic function. DESIGN AND METHODS: Thirty-one non-diabetic patients with hepatic cirrhosis and PHG (PHG+) were studied and compared with 17 cirrhotic patients without PHG (PHG-). All patients underwent endoscopy for the assessment of PHG and Helicobacter pylori status, ultrasound determination of the diameters of spleen and portal vein, and, subsequently, an oral load of sucrose, lactulose, and mannitol. Sugar concentrations were determined in 6-h urine specimens and expressed as a percentage of the orally administered dose or as lactulose/mannitol ratio. RESULTS: The urinary sucrose excretion was significantly elevated in patients with PHG compared to those without (PHG+, 0.20% +/- 0.03; PHG-, 0.07% +/- 0.01; P< 0.001). No difference was found for the small intestinal probes lactulose and mannitol. Gastric sucrose permeability correlated positively with the endoscopic lesion score (P < 0.001), but not with other parameters of portal hypertension or hepatic function. H. pylori status did not influence gastric permeability. The sensitivity of this test reached 100% for PHG scores > 2. CONCLUSIONS: Gastric permeability to sucrose is increased in patients with PHG, independently of the presence of H. pylori. Sucrose permeability may be useful for the follow-up of patients with PHG.


Assuntos
Mucosa Gástrica/metabolismo , Hipertensão Portal/complicações , Cirrose Hepática/complicações , Gastropatias/etiologia , Sacarose/urina , Feminino , Mucosa Gástrica/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Permeabilidade , Valor Preditivo dos Testes , Estatísticas não Paramétricas , Gastropatias/patologia , Sacarose/administração & dosagem
16.
Mol Reprod Dev ; 56(2 Suppl): 248-51, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10824977

RESUMO

Exogenous DNA molecules are spontaneously taken up by sperm cells, internalized in nuclei, and eventually integrated in the sperm genome. The actual occurrence of the integration suggests that the sperm chromosomal DNA is not uniformly and tightly packed with protamines, implying the existence of genomic sites where the chromosomal DNA is accessible to foreign molecules. We have characterized a hypersensitive, nucleosomal subfraction of mouse sperm chromatin that is highly enriched in unmethylated retroposon DNA from a variety of families. Here we propose that both the integration of exogenous DNA molecules, and the endogenous retroposition activity, occur in the same site(s) of sperm chromatin.


Assuntos
Nucleossomos/genética , Retroelementos , Espermatozoides/metabolismo , Animais , Southern Blotting , Cromatina/genética , Cromatina/metabolismo , Masculino , Metilação , Camundongos , Modelos Genéticos , Nucleossomos/metabolismo , Espermatozoides/ultraestrutura
17.
Mol Reprod Dev ; 56(2 Suppl): 301-5, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10824990

RESUMO

We have tested three parameters in sperm-mediated gene transfer assays with mice and pigs: (i) the epididymal versus ejaculated origin of sperm cells, (ii) the primary structure, and (iii) the amount of the challenging foreign DNA. We have found that the pVLCNhGH construct, of retrotransposon origin, causes a massive embryo lethality and yet increases the yield of genetic transformation among born animals of both species compared to viral constructs. Arrest of embryonic development is a DNA dose-dependent effect, which is observed with high DNA doses, while lower doses are compatible with development. Finally, the overall efficiency of sperm-mediated gene transfer is higher when ejaculated, versus epididymal, spermatozoa are used. We suggest that this difference is related to the highly efficient apoptotic response in epididymal compared to ejaculated spermatozoa, triggered by the interaction of exogenous DNA molecules with the sperm membrane.


Assuntos
DNA/genética , Técnicas de Transferência de Genes , Espermatozoides , Animais , Animais Geneticamente Modificados , Animais Recém-Nascidos , Sequência de Bases , Southern Blotting , Ejaculação , Desenvolvimento Embrionário e Fetal , Epididimo/citologia , Feminino , Dosagem de Genes , Técnicas In Vitro , Inseminação Artificial , Masculino , Camundongos , Suínos
18.
J Cell Biol ; 148(6): 1107-13, 2000 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-10725323

RESUMO

We show here that a reverse transcriptase (RT) activity is present in murine epididymal spermatozoa. Sperm cells incubated with human poliovirus RNA can take up exogenous RNA molecules and internalize them in nuclei. Direct PCR amplification of DNA extracted from RNA-incubated spermatozoa indicate that poliovirus RNA is reverse-transcribed in cDNA fragments. PCR analysis of two-cell embryos shows that poliovirus RNA-challenged spermatozoa transfer retrotranscribed cDNA molecules into eggs during in vitro fertilization. Finally, RT molecules can be visualized on sperm nuclear scaffolds by immunogold electron microscopy. These results, therefore, reveal a novel metabolic function in spermatozoa, which may play a role during early embryonic development.


Assuntos
Núcleo Celular/enzimologia , RNA Viral/metabolismo , DNA Polimerase Dirigida por RNA/metabolismo , Espermatozoides/enzimologia , Animais , Núcleo Celular/ultraestrutura , Epididimo , Feminino , Humanos , Cinética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Oócitos/fisiologia , Poliovirus/genética , Reação em Cadeia da Polimerase , Motilidade dos Espermatozoides , Espermatozoides/fisiologia , Espermatozoides/ultraestrutura
19.
Neurology ; 54(3): 759-62, 2000 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-10680822

RESUMO

Neurogenic stunned myocardium (NSM), a syndrome of reversible left ventricular dysfunction best described after subarachnoid hemorrhage, has not been associated with peripheral neuropathy. We describe a woman with Guillain-Barre syndrome in whom a syndrome compatible with NSM developed in the setting of a physiologically documented increase in sympathetic cardiovascular tone. This case supports the presumed unifying role of excessive sympathetic nervous system activation in the pathogenesis of NSM.


Assuntos
Síndrome de Guillain-Barré/fisiopatologia , Coração/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Adulto , Eletroencefalografia , Feminino , Síndrome de Guillain-Barré/complicações , Humanos , Disfunção Ventricular Esquerda/complicações
20.
J Cell Sci ; 112 ( Pt 20): 3537-48, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10504302

RESUMO

We have characterized a nuclease hypersensitive chromatin fraction from murine spermatozoa. Endogenous nuclease activity can be induced in mouse epididymal spermatozoa by appropriate stimuli and cause the localized degradation of chromosomal DNA. Based on these observations, we have isolated nuclease hypersensitive chromatin regions released from spermatozoa in the supernatant of pelleted sperm cells, and have cloned and characterized the DNA. Gel electrophoresis of end-labelled released DNA fragments showed a typical nucleosomal distribution. Peripherally distributed nucleohistones were visualized by immunofluorescence in sperm nuclei, and histones were identified by western blot in sperm chromatin. Moreover, the released DNA is enriched in retroposon DNA from a variety of families. FISH and immunofluorescence analysis showed that retroposon DNA and nucleohistone chromatin co-localize and are both peripherically distributed in nuclei of spermatozoa. In contrast, a major satellite DNA probe, used for control, co-localizes with highly condensed chromatin in the central region of sperm nuclei. The nuclear Ran and RCC1 proteins were also visualized in the dorsal margin of sperm nuclei, and were abundantly released with the hypersensitive chromatin fraction. Together, these results indicate that nucleohistone chromatin fraction(s) with typical features of 'active' chromatin are present in murine spermatozoa, are hypersensitive to nuclease cleavage, enriched in retroposon DNA and organized in nucleosomal domains. These observations suggest that nucleohistone domains identify a fraction of the sperm genome which may be functional during early embryogenesis.


Assuntos
Cromatina/ultraestrutura , Nucleossomos/ultraestrutura , Retroelementos , Espermatozoides/ultraestrutura , Animais , Núcleo Celular/fisiologia , Núcleo Celular/ultraestrutura , Epididimo/fisiologia , Biblioteca Genômica , Humanos , Hibridização in Situ Fluorescente , Masculino , Camundongos , Nucleossomos/genética , Motilidade dos Espermatozoides , Espermatozoides/fisiologia
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