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1.
J Dairy Sci ; 101(8): 6715-6729, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29859690

RESUMO

Dairy small ruminants account for approximately 21% of all sheep and goats in the world, produce around 3.5% of the world's milk, and are mainly located in subtropical-temperate areas of Asia, Europe, and Africa. Dairy sheep are concentrated around the Mediterranean and Black Sea regions, where their dairy products are typical ingredients of the human diet. Dairy goats are concentrated in low-income, food-deficit countries of the Indian subcontinent, where their products are a key food source, but are also present in high-income, technologically developed countries. This review evaluates the status of the dairy sheep and goat sectors in the world, with special focus on the commercially and technically developed industries in France, Greece, Italy, and Spain (FGIS). Dairy small ruminants account for a minor part of the total agricultural output in France, Italy, and Spain (0.9 to 1.8%) and a larger part in Greece (8.8%). In FGIS, the dairy sheep industry is based on local breeds and crossbreeds raised under semi-intensive and intensive systems and is concentrated in a few regions in these countries. Average flock size varies from small to medium (140 to 333 ewes/farm), and milk yield from low to medium (85 to 216 L/ewe), showing substantial room for improvement. Most sheep milk is sold to industries and processed into traditional cheese types, many of which are Protected Denomination of Origin (PDO) cheeses for gourmet and export markets (e.g., Pecorino, Manchego, and Roquefort). By comparing break-even milk price among FGIS countries, we observed the following: (1) most Greek and French dairy sheep farms were unprofitable, with the exception of the intensive Chios farms of Greece; (2) milk price was aligned with cost of production in Italy; and (3) profitable farms coexisted with unprofitable farms in Spain. In FGIS, dairy goat production is based on local breeds raised under more extensive systems than sheep. Compared with sheep, average dairy goat herds are smaller (36 to 190 does/farm) but milk yield is greater (153 to 589 L/doe), showing room for improvement. Goat milk is mainly processed on-farm into dairy products for national markets, but some PDO goat milk cheeses (e.g., Murcia al Vino) are exported. Processed goat milk is sold for local human consumption or dehydrated for export. Mixed sheep-goat (e.g., Feta) and cow-sheep-goat milk cheeses are common in many countries. Strategies to improve the dairy sheep and goat sectors in these 4 countries are proposed and discussed.


Assuntos
Indústria de Laticínios/economia , Indústria de Laticínios/métodos , Cabras , Abrigo para Animais , Ovinos , Animais , Fazendas , Feminino , Humanos , Leite
2.
Br J Cancer ; 103(5): 597-606, 2010 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-20733579

RESUMO

BACKGROUND: CYT997 is a novel microtubule inhibitor and vascular-disrupting agent with marked preclinical anti-tumour activity. METHODS: This phase I dose-escalation study assessed the safety, tolerability, pharmacokinetics and pharmacodynamics of CYT997 administered by continuous intravenous infusion over 24 h every 3 weeks to patients with advanced solid tumours. RESULTS: Thirty-one patients received CYT997 over 12 dose levels (7-358 mg m(-2)). Doses up to 202 mg m(-2) were well tolerated. Dose-limiting toxicities were observed at 269 and 358 mg m(-2), consisting of grade 3 prolonged corrected QT interval in two patients and grade 3 hypoxia and grade 4 dyspnea in one patient. All toxicities were reversible. The pharmacokinetics of CYT997 were linear over the entire dose range. Dynamic contrast-enhanced magnetic resonance imaging scans showed significant changes in tumour K(trans) values consistent with vascular disruption in 7 out of 11 evaluable patients treated at CYT997 doses of >or=65 mg m(-2). Moreover, plasma levels of von Willebrand factor and caspase-cleaved cytokeratin-18 increased post-treatment at higher dose levels. Among 22 patients evaluable for response, 18 achieved stable disease for >2 cycles. CONCLUSIONS: CYT997 was well tolerated at doses that were associated with pharmacodynamic evidence of vascular disruption in tumours.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Antineoplásicos/administração & dosagem , Piridinas/administração & dosagem , Pirimidinas/administração & dosagem , Adulto , Idoso , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/farmacocinética , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Contagem de Células , Células Endoteliais , Feminino , Humanos , Queratina-18/análise , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Piridinas/efeitos adversos , Piridinas/farmacocinética , Pirimidinas/efeitos adversos , Pirimidinas/farmacocinética , Fator de von Willebrand/análise , Fator de von Willebrand/imunologia
3.
Nutr Metab Cardiovasc Dis ; 20(7): 519-26, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19703761

RESUMO

BACKGROUND AND AIMS: Once-daily (OD) basal insulin glargine (GLA) can be used as part of a multiple daily injection regimen in patients with type 1 diabetes mellitus. This randomized, multicenter study compared GLA+prandial regular human insulin (RHI) with GLA+prandial insulin lispro (LIS) in reducing the incidence of severe nocturnal hypoglycemia at endpoint. In addition, the effects on glycemic control of both treatments were investigated. METHODS AND RESULTS: Patients (489) previously on neutral protamine Hagedorn (NPH) insulin or GLAR plus RHI/LIS were switched to, or continued on GLA (target fasting blood glucose [FBG]=5.0-6.7 mmol/L [90-120 mg/dL]) for 8 weeks (qualification phase) prior to randomization; patients continued with their previous bolus insulin. Patients (n=395) were then randomized to LIS (n=193) or RHI (n=202) and treated for 16 weeks. The proportion of patients experiencing severe nocturnal hypoglycemia at the end of the study was 1.55% (n=3) in the RHI group and 1.11% (n=2) in the LIS group (p=0.938 between groups); the mean difference was 0.44% (95% CI: -1.77, 2.21), suggesting non-inferiority of RHI versus LIS. At the end of the study, both treatments did not differ with respect to glycemic control, as measured by hemoglobin A(1c) and FBG. CONCLUSION: These results suggest that GLA+LIS and GLA+RHI treatments were associated with a similar and low rate of severe nocturnal hypoglycemia. Further studies with greater patient sizes are necessary to verify the findings from the current study.


Assuntos
Glicemia/efeitos dos fármacos , Ritmo Circadiano , Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/efeitos adversos , Insulina/análogos & derivados , Adulto , Biomarcadores/sangue , Diabetes Mellitus Tipo 1/sangue , Quimioterapia Combinada , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/sangue , Hipoglicemia/epidemiologia , Incidência , Insulina/efeitos adversos , Insulina Glargina , Insulina Lispro , Insulina de Ação Prolongada , Itália , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
4.
Animal ; 13(10): 2260-2267, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30838969

RESUMO

Spineless cactus is a useful feed for various animal species in arid and semiarid regions due to its adaptability to dry and harsh soil, high efficiency of water use and carbohydrates storage. This meta-analysis was carried out to assess the effect of spineless cactus on animal performance, and develop and evaluate equations to predict dry matter intake (DMI) and average daily gain (ADG) in meat lambs. Equations for predicting DMI and ADG as a function of animal and diet characteristics were developed using data from eight experiments. The dataset was comprised of 40 treatment means from 289 meat lambs, in which cactus was included from 0 to 75% of the diet dry matter (DM). Accuracy and precision were evaluated by cross-validation using the mean square error of prediction (MSEP), which was decomposed into mean bias, systematic bias and random error; concordance correlation coefficient, which was decomposed into accuracy (Cb) and precision (ρ); and coefficient of determination (R2). In addition, the data set was used to evaluate the predicting accuracy and precision of the main lamb feeding systems (Agricultural and Food Research Council, Small Ruminant Nutritional System, National Research Council and Institut National de la Recherche Agronomique) and also two Brazilian studies. The DMI, CP intake (CPI), metabolizable energy (ME) intake and ADG increased when cactus was included up to 499 g/kg DM (P<0.001). In contrast, animals fed high levels of cactus (>500 g/kg DM) had a decreased DMI, CPI and NDF intake, but increased feed efficiency (P<0.001) and similar ADG compared with those without cactus addition. The DMI was positively correlated with initial BW, final BW, concentrate and ADG, while it was negatively correlated with cactus inclusion and ME of the diet. On other hand, ADG was positively correlated with DMI, initial and mean BW and concentrate, and it was negatively correlated with cactus inclusion. The two developed equations had high accuracy (Cb of 0.95 for DMI and 0.94 for ADG) and the random error of MSEP was 99% for both equations. The precision of both equations was moderate, with R2 values of 0.53 and 0.50 and ρ values of 0.73 and 0.71 for DMI and ADG, respectively. In conclusion, the developed equation to predict DMI had moderate precision and high accuracy, nonetheless, it was more efficient than those reported in the literature. The proposed equations can be a useful alternative to estimate intake and performance of lambs fed cactus.


Assuntos
Ração Animal/análise , Cactaceae , Ingestão de Alimentos , Metabolismo Energético , Modelos Teóricos , Ovinos/crescimento & desenvolvimento , Animais , Brasil , Dieta/veterinária , Masculino , Modelos Biológicos , Distribuição Aleatória , Carne Vermelha/análise , Ovinos/fisiologia , Aumento de Peso
5.
Arterioscler Thromb Vasc Biol ; 21(7): 1118-23, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11451739

RESUMO

Rat aortic smooth muscle cells (SMCs) cultured from intimal thickening 15 days after endothelial injury (IT-15), unlike those of normal media, show a monolayered, epithelioid phenotype and high levels of cellular retinol binding protein-1 (CRBP). Epithelioid clones obtained from the normal media suggest a "mosaicism" of arterial SMCs. Intimal cell homeostasis from the balance of proliferation and apoptosis is critical for the progression of vascular lesions. All-trans retinoic acid (tRA) reduced [(3)H]thymidine incorporation and G(1)-->S phase progression of IT-15 and epithelioid clone but not of normal media and IT 60 days after injury (IT-60) SMCs. Hoechst staining, flow cytometry, and ligation-mediated polymerase chain reaction showed an increased susceptibility of IT-15 and epithelioid clone to tRA and cis-diaminedichloroplatinum II (CDDP)-induced apoptosis and cytotoxicity compared with normal media and IT-60 cells. The latter retained an increased susceptibility to tRA-induced apoptosis compared with normal media SMCs. tRA-induced apoptosis associated with an increased ratio of bax to bcl-2 by bax overexpression and cleavage of caspase-3. Anti-CRBP but not anti-IgG antibody prevented tRA-induced apoptosis and changes in related signaling molecules but not CDDP effects. Our findings support the relevant role of phenotypic heterogeneity in the determining proliferative as well as apoptotic behavior of arterial SMCs.


Assuntos
Aorta/citologia , Apoptose , Arteriosclerose/patologia , Cisplatino/farmacologia , Músculo Liso Vascular/patologia , Tretinoína/farmacologia , Animais , Arteriosclerose/etiologia , Arteriosclerose/metabolismo , Western Blotting , Ciclo Celular , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Proteínas do Citoesqueleto/metabolismo , Imunofluorescência , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Fenótipo , Ratos , Ratos Wistar
6.
Transplant Proc ; 37(5): 2240-3, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15964387

RESUMO

Therapeutic drug monitoring (TDM) is essential to maintain the efficacy of many immunosuppressant drugs while minimizing their toxicity. TDM of mycophenolate mofetil requires area under the curve AUC determinations but appears laborious, costly, and clinically impractical. To overcome these problems, limited sampling strategies (LSS) have been proposed in adult and pediatric renal transplant patients. The purpose of this study was to develop an LSS in heart transplant patients. Forty-four mycophenolic acid (MPA) full AUC(0-12h) profiles were generated by high-performance liquid chromatography in nine heart transplant patients during the first 12 weeks posttransplant. Each patient received concomitant cyclosporine and prednisone therapy. Multiple stepwise regression analysis was used to define the time points of MPA levels to explain the MPA AUC(0-12h). Agreement between abbreviated AUC and the full AUC(0-12h) was tested by means of a Bland and Altman analysis. The highest coefficient of determination r(2) among MPA AUC and single concentrations (r(2) = .610) was observed with C(2), while C(12) provided the lowest one (r(2) = .003). Stepwise linear regression showed that the minimal model with the best estimation of MPA AUC(0-12h) was obtained at timed values of 1.25, 2, and 6 hours. The corresponding estimated model was AUC = 5.568 + 0.902 * C(1.25) + 2.022 * C(2) + 4.594 * C(6) (r(2) = .926). Bland and Altman analysis revealed good agreement between predicted AUC and full AUC. A further interesting model equation obtained by four samples was AUC = 3.800 + 1.015 * C(1.25) + 1.819 * C(2) + 1.566 * C(4) + 3.479 * C(6) (r(2) = .948).


Assuntos
Transplante de Coração/imunologia , Ácido Micofenólico/sangue , Ácido Micofenólico/uso terapêutico , Adulto , Idoso , Área Sob a Curva , Criança , Ciclosporina/uso terapêutico , Monitoramento de Medicamentos/métodos , Humanos , Imunossupressores/sangue , Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Pessoa de Meia-Idade , Ácido Micofenólico/análogos & derivados , Análise de Regressão , Viés de Seleção
7.
Clin Infect Dis ; 33(11): 1871-8, 2001 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-11692299

RESUMO

We sought the reservoir of Fusarium species in a hospital with cases of known fusarial infections. Cultures of samples from patients and the environment were performed and evaluated for relatedness by use of molecular methods. Fusarium species was recovered from 162 (57%) of 283 water system samples. Of 92 sink drains tested, 72 (88%) yielded Fusarium solani; 12 (16%) of 71 sink faucet aerators and 2 (8%) of 26 shower heads yielded Fusarium oxysporum. Fusarium solani was isolated from the hospital water tank. Aerosolization of Fusarium species was documented after running the showers. Molecular biotyping revealed multiple distinct genotypes among the isolates from the environment and patients. Eight of 20 patients with F. solani infections had isolates with a molecular match with either an environmental isolate (n=2) or another patient isolate (n=6). The time interval between the 2 matched patient-environment isolates pairs was 5 and 11 months, and 2, 4, and 5.5 years for the 3 patient-patient isolate pairs. The water distribution system of a hospital was identified as a reservoir of Fusarium species.


Assuntos
Infecção Hospitalar/epidemiologia , Fusarium/isolamento & purificação , Micoses/epidemiologia , Infecções Oportunistas/epidemiologia , Microbiologia da Água , Microbiologia do Ar , Infecção Hospitalar/microbiologia , DNA Bacteriano/análise , Fusarium/genética , Humanos , Micoses/microbiologia , Infecções Oportunistas/microbiologia
8.
Gene ; 132(2): 255-60, 1993 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-8224872

RESUMO

We present here the cloning and the entire sequence of one of the two gene copies coding for ribosomal protein (r-protein) S8 in Xenopus laevis (corresponding to r-protein S7 in rat) and its flanking regions. The S8a gene contains seven exons and six introns for a total length of about 12,700 bp coding for a mRNA of 663 nucleotides (nt) plus a poly(A) tail. Mapping of the 5' end of the gene has shown that the transcription start point is located in a pyrimidine-rich tract, as has been observed for all r-protein-encoding genes of X. laevis and other vertebrates so far characterized. A computer analysis of the S8a sequence has revealed the presence of a 220-nt sequence repeated, with some variations, once in each of the six introns. RNA analysis by hybridization with oligo probes specific for the two gene copies coding for r-protein S8 has demonstrated that the two of them are expressed at similar levels both in oocytes and in embryos.


Assuntos
Proteínas Ribossômicas/genética , Xenopus laevis/genética , Animais , Sequência de Bases , Southern Blotting , Clonagem Molecular , DNA , Éxons , Íntrons , Dados de Sequência Molecular , Mapeamento por Restrição
9.
Phys Med ; 17 Suppl 1: 261-3, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11780614

RESUMO

Aim of this investigation is the study of the modifications and the DNA damage occurring in thyroid cells exposed to radiation. The FRTL-5 rat thyroid cell strain has been chosen for this study. Objects of this research are both Ionizing radiation, of fundamental interest for space missions, and the UV radiation, (also mutagen and frequent cause of several cancer forms). The present study of UV radiation represents a preliminarily tool to investigate the biological radiation damage. FRTL-5 cells have been irradiated with doses of UV-C (254 nm wavelength) ranging from 15 to 80 Joule/m2. The DNA damage has been analyzed with the 'DNA ladder by gel electrophoresis' technique. DNA has been extracted at 24 and 48 hours from irradiation. At 24h the apoptotic process is not detectable. At 48 h from irradiation, cells show the characteristic signs of apoptosis. The lower dose to which the apoptotic process is detectable, corresponds to 20 Joule/m2. At the higher doses a bigger percentage of cells undergoes apoptosis. These data confirms that the FRTL-5 biological system is particularly suitable for further studies on the biological mechanisms of radiation damage.


Assuntos
Apoptose/efeitos da radiação , Dano ao DNA , DNA/efeitos da radiação , Glândula Tireoide/efeitos da radiação , Raios Ultravioleta , Animais , Linhagem Celular , Células Cultivadas/efeitos da radiação , Relação Dose-Resposta à Radiação , Ratos , Glândula Tireoide/citologia
10.
Phys Med ; 17 Suppl 1: 232-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11776984

RESUMO

The comet assay is a sensitive and rapid method for DNA strand break detection in individual cells. The principle of break detection, using either the alkaline or neutral version of the assay, makes it a good technique for studying both double and single strand DNA breaks. Furthermore, the possibility of following DNA damage at different time moments also makes it possible to investigate the cell repair mechanisms. This explains why in the last few years there has been a tremendous increase in the number of laboratories which started to use this technique. The technique was first created for lymphocyte cells and later on has been used on many other cell types, growing both in suspension and adherent. To date, no one has applied this technique on normal differentiated endocrine cells, such as FRTL5 cells (Fisher Rat Thyroid Cells). The aim of this study has been to standardize the alkaline version of the Comet Assay technique on FRTL5 cells by studying the kinetics of DNA-damage and DNA-repair after different doses of UV-C (254 nm). FRTL-5 cells not only resulted very sensitive to UV-C (p<0.05 at 5 J/m2), but were also able to repair most of their DNA damage very rapidly (within one hour) as shown by a significant exponential regression in comet length. Finally, the successful measurement of biomarkers of UV-C on thyroid cells established the comet assay as a valuable tool in measurement of DNA damage and repair. Any radiation, or other damaging agents, interacting with living organisms could cause DNA damages which, depending upon dosages and kinetics of exposure, may or may not be completely repaired.


Assuntos
Ensaio Cometa/métodos , Dano ao DNA , Reparo do DNA , Glândula Tireoide/citologia , Raios Ultravioleta , Animais , Linhagem Celular , Células Cultivadas/efeitos da radiação , Relação Dose-Resposta à Radiação , Ratos , Ratos Endogâmicos F344
11.
Recenti Prog Med ; 83(2): 85-8, 1992 Feb.
Artigo em Italiano | MEDLINE | ID: mdl-1502426

RESUMO

Aim of the study is the evaluation of therapeutic effectiveness of nimodipine in acute focal cerebral ischaemia. Thirty patients affected by minor ischaemic stroke divided in two randomized groups have been studied consecutively: all the patients were treated with standard therapy, nimodipine was delivered in addition only to the patients of the first group. Both clinical evaluation using Mathew scale, modified by Gelmers, and flowmetric evaluation with SPECT were performed at different times. The results haven't shown any significant statistical difference in the effectiveness of the therapy between the two groups even if a positive clinical trend was evidenced in the group treated with nimodipine. The flowmetric study has shown the poor homogeneity of the groups from a physiopathological point of view not-with-standing the two groups were similar for the clinical severity, sex, age and vascular risk factors. We conclude that is advisable to carry out further trials in which the comparison study groups are more numerous and balanced also from a physiopathological point of view.


Assuntos
Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular/efeitos dos fármacos , Ataque Isquêmico Transitório/tratamento farmacológico , Nimodipina/uso terapêutico , Tomografia Computadorizada de Emissão de Fóton Único , Doença Aguda , Idoso , Humanos , Ataque Isquêmico Transitório/diagnóstico por imagem , Ataque Isquêmico Transitório/fisiopatologia , Pessoa de Meia-Idade , Fatores de Tempo
13.
Nucleic Acids Res ; 21(20): 4721-5, 1993 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-8233819

RESUMO

The regulation of the synthesis of elongation factor 1 alpha (EF-1 alpha) in Xenopus laevis has been analyzed from the point of view of translational control. The 5' end of EF-1 alpha mRNA, examined by primer extension, revealed the presence of a terminal pyrimidine tract that is characteristic of ribosomal protein mRNAs (rp-mRNAs). We have then compared the translation pattern of EF-1 alpha and rp-mRNAs during Xenopus embryogenesis and in Xenopus cultured cells during growth rate changes. In Xenopus embryos EF-1 alpha transcripts, that appear after midblastula transition, are initially mostly localized on mRNP and translationally inactive. Only later in embryogenesis, together with rp-mRNAs, they are gradually recruited on polysomes. Also in Xenopus cells B 3.2, EF-1 alpha mRNA shows a distribution change similar to an rp-mRNA: part of it moves from polysomes to mRNP during serum deprivation and goes back on polysomes after restitution of serum to the culture. Moreover EF-1 alpha mRNA, similarly to rp-mRNAs, is always localized on mRNP or fully loaded on polysomes but never on small polysomes. Therefore EF-1 alpha mRNA for structural features and translation behavior can be included in the 'regulatory' group of rp-mRNAs.


Assuntos
Fatores de Alongamento de Peptídeos/genética , Biossíntese de Proteínas , Proteínas Ribossômicas/genética , Animais , Sequência de Bases , Northern Blotting , Células Cultivadas , Regulação da Expressão Gênica , Dados de Sequência Molecular , Fator 1 de Elongação de Peptídeos , Fatores de Alongamento de Peptídeos/biossíntese , RNA Mensageiro/química , Proteínas Ribossômicas/biossíntese , Transcrição Gênica , Xenopus laevis
14.
Proc Natl Acad Sci U S A ; 97(11): 6185-90, 2000 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-10823959

RESUMO

Signaling by the metabotropic glutamate receptor 1alpha (mGluR1alpha) can lead to the accumulation of inositol 1,4, 5-trisphosphate (InsP(3)) and cAMP and to the modulation of K(+) and Ca(2+) channel opening. At present, very little is known about how these different actions are integrated and eventually turned off. Unraveling the molecular mechanisms underlying these functions is crucial for understanding mGluR-mediated regulation of synaptic transmission. It has been shown that receptor-induced activation of the InsP(3) pathway is subject to feedback inhibition mediated by protein kinase C (PKC). In this study, we provide evidence for a differential regulation by PKC and protein kinase A of two distinct mGluR1alpha-dependent signaling pathways. PKC activation selectively inhibits agonist-dependent stimulation of the InsP(3) pathway but does not affect receptor signaling via cAMP. In contrast, protein kinase A potentiates agonist-independent signaling of the receptor via InsP(3). Furthermore, we demonstrate that the selectivity of PKC action on receptor signaling rests on phosphorylation of a threonine residue located in the G protein-interacting domain of the receptor. Modification at Thr(695) selectively disrupts mGluR1alpha-G(q/11) interaction without affecting signaling through G(s). Together, these data provide insight on the mechanisms by which selective down-regulation of a specific receptor-dependent signaling pathway can be achieved and on how cross-talk between different second messenger cascades may contribute to fine-tune short- and long-term receptor activity.


Assuntos
Sinalização do Cálcio/fisiologia , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Inositol 1,4,5-Trifosfato/fisiologia , Proteína Quinase C/fisiologia , Processamento de Proteína Pós-Traducional , Receptores de Glutamato Metabotrópico/fisiologia , Regulação Alostérica , Sequência de Aminoácidos , Animais , AMP Cíclico/fisiologia , Transporte de Íons , Dados de Sequência Molecular , Oócitos , Técnicas de Patch-Clamp , Fosforilação , Fosfotreonina/análise , Estrutura Terciária de Proteína , Receptores de Glutamato Metabotrópico/química , Proteínas Recombinantes de Fusão/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transfecção , Xenopus laevis
15.
J Biol Chem ; 273(10): 5615-24, 1998 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-9488690

RESUMO

On the basis of sequence homology and structural similarities, metabotropic glutamate receptors (mGluRs), extracellular Ca2+-sensing receptor, gamma-aminobutyric acid type B receptor, and pheromone receptors are enlisted in a distinct family within the larger G protein-coupled receptor superfamily. When expressed in heterologous systems, group I mGluRs can activate dual signal transduction pathways, phosphoinositides turnover and cAMP production. To investigate the structural basis of these coupling properties, we introduced single amino acid substitutions within the second and third intracellular loops (i2 and i3) of mGluR1alpha. Wild-type and mutant receptors were expressed in human embryonic kidney 293 cells and analyzed for their capacity to stimulate both signaling cascades. Each domain appeared to be critical for the coupling to phospholipase C and adenylyl cyclase. Within i2, Thr695, Lys697, and Ser702 were found to be selectively involved in the interaction with Gq class alpha subunit(s), whereas mutation of Pro698 and the deletion Cys694-Thr695 affected only Gs coupling. Furthermore, the mutation K690A profoundly altered mGluR1alpha signaling properties and imparted to the receptor the ability to couple to the inhibitory cAMP pathway. Within i3, we uncovered two residues, Arg775 and Phe781, that are crucial for coupling to both pathways, since their substitution leads to receptor inactivation.


Assuntos
Receptores de Glutamato Metabotrópico/química , Transdução de Sinais/fisiologia , Toxina Adenilato Ciclase , Adenilil Ciclases/metabolismo , Sequência de Aminoácidos , Linhagem Celular , AMP Cíclico/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Regulação da Expressão Gênica/genética , Ácido Glutâmico/farmacologia , Humanos , Imuno-Histoquímica , Isoproterenol/farmacologia , Rim/metabolismo , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida/genética , Receptores de Glutamato Metabotrópico/genética , Alinhamento de Sequência , Transfecção/genética , Fosfolipases Tipo C/metabolismo , Fatores de Virulência de Bordetella/farmacologia
16.
Nucleic Acids Res ; 20(8): 1859-63, 1992 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-1579486

RESUMO

We have analyzed several randomly selected mRNAs, of the relatively abundant category, on the basis of maternal or zygotic origin and translational efficiency at different developmental stages. For this purpose, clones from a Xenopus embryo cDNA library were hybridized with cDNA probes prepared with poly(A)+RNA from polysomes and from mRNPs of embryos at different stages. The results obtained indicate that the majority of the relatively abundant mRNAs (38 out of 61) is subject to some kind of translational regulation during embryogenesis. Moreover, 30 clones have been selected as corresponding to mRNAs that behave, from the point of view of transcriptional and translational regulation, similarly to previously studied ribosomal protein (r-protein) mRNAs. Sequence analysis of 20 of these selected cDNAs has shown that half of them are in fact homologous to already sequenced r-protein mRNAs. Unexpectedly we have found that also the mRNA for alpha-cardiac actin and another mRNA homologous to creatine kinase M mRNA have a similar translational regulation during embryogenesis.


Assuntos
Embrião não Mamífero/metabolismo , Regulação da Expressão Gênica/genética , Biossíntese de Proteínas/genética , RNA Mensageiro/genética , Proteínas Ribossômicas/genética , Actinas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Clonagem Molecular , Creatina Quinase/genética , Sondas de DNA/genética , Dados de Sequência Molecular , Xenopus laevis
17.
Virology ; 189(2): 657-67, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1322594

RESUMO

The Marek's disease virus (MDV) gene encoding a homologue to the ICP4 protein of herpes simplex virus has been mapped to BamHl fragment A based on the physical map of the MDV genome (Fukuchi et al., 1984). The gene lies completely within the inverted repeat flanking the unique short region of the genome. The complete nucleotide sequence of the MDV ICP4 gene has been determined. The coding region is 4245 nucleotides long and has an overall G+C content of 52%. The MDV ICP4 protein is predicted to have a structure similar to that of ICP4-like proteins of other herpesviruses in that it has five distinct regions, the second and fourth of which are highly conserved. In addition, the protein contains the characteristic run of serine residues located toward its amino terminus. The MDV ICP4 gene is expressed in MDV-infected chicken embryo fibroblasts.


Assuntos
Genes Virais , Herpesvirus Galináceo 2/genética , Proteínas Nucleares/genética , Transativadores/genética , Proteínas Virais , Proteínas Estruturais Virais/genética , Sequência de Aminoácidos , Sequência de Bases , Expressão Gênica , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos/química , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , RNA Viral/genética , Mapeamento por Restrição
18.
Int J Gynecol Cancer ; 11(3): 224-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11437929

RESUMO

We describe a very rare association between intraepithelial, extramammary Paget's disease and human papillomavirus- (HPV) negative, keratinized type of VIN III observed in two elderly women. In both cases, morphological and immunohistochemical investigation showed two heterogeneous but intimately admixed neoplastic populations of vulvar epithelium. Atypical keratinocytes stained markedly and diffusely positive for high molecular weight cytokeratins, and moderately for p53 protein and c-erbB-2 immunostainings. Paget cells were diffusely positive for CEA, EMA, and low molecular weight cytokeratins, moderately and focally for c-erbB-2 and (in one case) for S-100. Morphological and immunohistochemical phenotypic differences between Paget cells and atypical keratinocytes suggest a simultaneous and incidental association of two distinct neoplastic disorders more than a mixed carcinoma in situ of vulvar epithelium.


Assuntos
Carcinoma in Situ/diagnóstico , Doença de Paget Extramamária/diagnóstico , Neoplasias Vulvares/diagnóstico , Idoso , Carcinoma in Situ/complicações , Diagnóstico Diferencial , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Doença de Paget Extramamária/complicações , Neoplasias Vulvares/complicações
19.
J Virol ; 65(3): 1584-8, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1847475

RESUMO

We have isolated a stable, recombinant Marek's disease virus (MDV) containing the lacZ gene of Escherichia coli inserted into the unique short region of the genome. The nucleotide sequence of the insertion site indicates that it lies within a sequence homologous to the US2 gene of herpes simplex virus. Stable insertion of the lacZ gene into the MDV US2 gene indicates that the site is nonessential for MDV growth in cell culture.


Assuntos
Escherichia coli/genética , Genes Bacterianos , Genes Virais , Herpesvirus Galináceo 2/genética , Recombinação Genética , Simplexvirus/genética , Transfecção , beta-Galactosidase/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Células Cultivadas , Embrião de Galinha , Escherichia coli/enzimologia , Dados de Sequência Molecular , Mapeamento por Restrição , Homologia de Sequência do Ácido Nucleico
20.
J Med Vet Mycol ; 35(2): 133-7, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9147273

RESUMO

Emergence of resistance of Candida albicans to antifungal triazoles is increasingly recognized as an important cause of refractory mucosal candidiasis in HIV-infected patients. Recently, CDR1, which is thought to be analogous to the human MDR-1 P-glycoprotein, has been cloned in C. albicans. It has been proposed that its expression is partially responsible for fluconazole resistance in C. albicans. This gene is characterized by the presence of an ATP binding cassette (ABC) region and is distinct from the BENr gene which does not encode such a functional domain. As the molecular basis for fluconazole resistance appears to be multifactorial, we considered that there may be other ATP binding cassette-containing MDR genes that may potentially contribute to antifungal azole resistance in C. albicans. We therefore sought to identify potential target sequences that may be derived from candidate genes that share homology with the ATP binding cassette region of the human MDR-1 P-glycoprotein. Degenerate oligonucleotide primers based on the known sequence from the ATP binding cassette region of the human MDR-1 P-glycoprotein were used to amplify PCR products within the range of 100 bp in length from C. albicans isolates (3 fluconazole-susceptible and 3 fluconazole-resistant). Sequence analysis of individually subcloned PCR products, derived from the six isolates revealed 34 sequences in total. The results of our study identified 14 clones (with at least one per isolate) with a high degree of homology to the ATP binding cassette of the human MDR-1 P-glycoprotein. The BLAST search did not disclose homology of these new sequences to the C. albicans CDR1 gene, suggesting that C. albicans may possess more than one MDR-like gene. We conclude that C. albicans may possess one or more additional genes encoding ATP binding cassette MDR-like proteins that are distinct from CDR 1 and which could participate in the development of fluconazole resistance.


Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Candida albicans/genética , Proteínas Fúngicas/genética , Genes Fúngicos , Proteínas de Membrana Transportadoras , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Sequência de Aminoácidos , Candida albicans/efeitos dos fármacos , Candida albicans/isolamento & purificação , Candidíase/tratamento farmacológico , Candidíase/etiologia , Candidíase Bucal/microbiologia , Criança , Resistência Microbiana a Medicamentos/genética , Resistência a Múltiplos Medicamentos/genética , Proteínas Fúngicas/química , Humanos , Dados de Sequência Molecular , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
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