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1.
J Clin Med Res ; 8(2): 126-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26767081

RESUMO

BACKGROUND: Despite measures taken to control traditional risk factors like increased rectal disease activity, anorectal stenosis, and, to a lesser extent, obesity, rates of poor outcomes after rectovaginal fistula (RVF) surgery in women with Crohn's disease (CD) are still high and require further elucidation. To bridge the gap, we sought to identify risk factors beyond the aforementioned determinants that may be associated with poor outcomes in these patients. METHODS: We designed a retrospective, unmatched, case-control study to test our hypothesis. The population comprised women with CD who underwent RVF surgery between the years of 2000 and 2013. Cases were defined as surgeries with an unsuccessful outcome at 4 weeks post-surgery, and controls represented those with a successful outcome at 4 weeks post-surgery. With multivariable logistic regression models, we sought to identify pertinent risk factors for poor outcomes after RVF surgery in these women. RESULTS: Of the 108 women with CD who were referred to our institution for evaluation of RVFs between 2000 and 2013, 39 underwent a total of 63 surgeries, of which 16 were cases and 47 were controls. There were no significant differences between them with regard to medications and clinical or mucosal disease severity, but a significantly higher proportion of poor outcomes arose from the group of women who underwent a mucosal flap procedure (88%) compared to those who had a seton placed (13%; P = 0.0004). The final adjusted logistic regression model demonstrated that women who underwent a mucosal flap procedure instead of a seton placement were 17.5 times more likely to have a poor surgical outcome (odds ratio (OR): 17.51; 95% confidence interval (CI): 3.12 - 98.43; P = 0.0012). Moreover, it was seen that women with active colonic mucosal disease, independent of rectal disease activity, were 4.4 times more likely to have a poor outcome (OR: 4.40; 95% CI: 1.06 - 18.26). CONCLUSION: Mucosal flap procedures, representing the second, or definitive, stage in surgical treatment of RVF are associated with much worse outcomes and therefore should be preceded by aggressive medical optimization of the patient.

3.
Cell Prolif ; 44(6): 508-15, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21973075

RESUMO

Prostate cancer is a serious molecular disorder that arises because of reduction in tumour suppressors and overexpression of oncogenes. The malignant cells survive within the context of a three-dimensional microenvironment in which they are exposed to mechanical and physical cues. These signals are, nonetheless, deregulated through perturbations to mechanotransduction, from the nanoscale level to the tissue level. Increasingly sophisticated interpretations have uncovered significant contributions of signal transduction cascades in governing prostate cancer progression. To dismantle the major determinants that lie beneath disruption of spatiotemporal patterns of activity, crosstalk between various signalling cascades and their opposing and promoting effects on TRAIL-mediated activities cannot be ruled out. It is important to focus on that molecular multiplicity of cancer cells, various phenotypes reflecting expression of a variety of target oncogenes, reversible to irreversible, exclusive, overlapping or linked, coexist and compete with each other. Comprehensive investigations into TRAIL-mediated mitochondrial dynamics will remain a worthwhile area for underlining causes of tumourigenesis and for unravelling interference options.


Assuntos
Apoptose , Proteínas Hedgehog/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Proteínas Wnt/metabolismo , Animais , Proteínas Hedgehog/biossíntese , Proteínas Hedgehog/genética , Humanos , Masculino , Proteoma , Proteínas Wnt/biossíntese , Proteínas Wnt/genética , Via de Sinalização Wnt/efeitos dos fármacos
4.
Eur J Neurol ; 15(12): 1265-72, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19049542

RESUMO

BACKGROUND AND PURPOSE: Many patients with non-cancer diagnoses utilize palliative services. There is little data on the palliative care needs of patients with neurologic and neurosurgical disorders. METHODS: Retrospective chart review. Log sheets which contain all patients seen between January 2004 and 2007 by palliative medicine (PM) were reviewed. Patients with neurologic or neurosurgical disorders were identified and their in-patient charts and electronic records reviewed. Patients with cancer were excluded. RESULTS: A total of 1429 cancer patients were seen by PM. Neurologic or neurosurgical diseases were the second most common in patients seen by the PM service, in 177 cases. Forty-seven patients were excluded. Complete data was collected on 129 patients. Mean age was 70. Seventy-one (55%) were female. The most common neurologic diagnosis was ischemic stroke in 33 (26%). Seventy-five (58%) had symptoms recorded. Reasons for PM consultation included 'comfort measures' in 40 (39%) and 'hospice candidacy' in 38 (37%). The most common recommendation made by the PM service was morphine in 44 (42%). Sixty-three (49%) were deemed hospice appropriate. CONCLUSIONS: Our findings support the need for PM services for patients with various neurologic and neurosurgical disorders. Understanding these needs will allow for the tailoring of palliative care services to such patients.


Assuntos
Doenças do Sistema Nervoso/epidemiologia , Doenças do Sistema Nervoso/enfermagem , Cuidados Paliativos/normas , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos Cerebrovasculares/diagnóstico , Transtornos Cerebrovasculares/epidemiologia , Transtornos Cerebrovasculares/enfermagem , Doença Crônica/enfermagem , Feminino , Humanos , Testamentos Quanto à Vida/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/diagnóstico , Doenças Neurodegenerativas/diagnóstico , Doenças Neurodegenerativas/epidemiologia , Doenças Neurodegenerativas/enfermagem , Neurologia/estatística & dados numéricos , Neurologia/tendências , Neurocirurgia/estatística & dados numéricos , Neurocirurgia/tendências , Cuidados Paliativos/métodos , Admissão do Paciente/normas , Admissão do Paciente/estatística & dados numéricos , Equipe de Assistência ao Paciente/estatística & dados numéricos , Equipe de Assistência ao Paciente/tendências , Cuidados Pós-Operatórios/métodos , Cuidados Pós-Operatórios/normas , Encaminhamento e Consulta/estatística & dados numéricos , Encaminhamento e Consulta/tendências , Estudos Retrospectivos , Apoio Social
5.
Am J Physiol Renal Physiol ; 290(6): F1285-94, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16682484

RESUMO

Amiloride-sensitive epithelial Na+ channels (ENaC) play a crucial role in Na+ transport and fluid reabsorption in the kidney, lung, and colon. The magnitude of ENaC-mediated Na+ transport in epithelial cells depends on the average open probability of the channels and the number of channels on the apical surface of epithelial cells. The number of channels in the apical membrane, in turn, depends on a balance between the rate of ENaC insertion and the rate of removal from the apical membrane. ENaC is made up of three homologous subunits: alpha, beta, and gamma. The COOH-terminal domain of all three subunits is intracellular and contains a proline-rich motif (PPxY). Mutations or deletion of this PPxY motif in the beta- and gamma-subunits prevent the binding of one isoform of a specific ubiquitin ligase, neural precursor cell-expressed, developmentally downregulated protein (Nedd4-2), to the channel in vitro and in transfected cell systems, thereby impeding ubiquitin conjugation of the channel subunits. Ubiquitin conjugation would seem to imply that ENaC turnover is determined by the ubiquitin-proteasome system, but when Madin-Darby canine kidney cells are transfected with ENaC, ubiquitin conjugation apparently leads to lysosomal degradation. However, in untransfected renal cells (A6) expressing endogenous ENaC, ENaC is indeed degraded by the ubiquitin-proteasome system. Nonetheless, in both transfected and untransfected cells, the rate of ENaC degradation is apparently controlled by Nedd4-2 activity. In this review, we discuss the role of the ubiquitin conjugation and the alternative degradative pathways (lysosomal or proteasomal) in regulating the rate of ENaC turnover in untransfected renal cells and compare this regulation to that of transfected cell systems.


Assuntos
Células Epiteliais/química , Complexo de Endopeptidases do Proteassoma/metabolismo , Canais de Sódio/fisiologia , Ubiquitina/metabolismo , Animais , Transporte Biológico/fisiologia , Linhagem Celular , Cães , Complexos Endossomais de Distribuição Requeridos para Transporte , Células Epiteliais/metabolismo , Canais Epiteliais de Sódio , Humanos , Rim , Proteínas de Membrana/metabolismo , Mutação , Ubiquitina-Proteína Ligases Nedd4 , Prolina , Subunidades Proteicas/química , Subunidades Proteicas/fisiologia , Sódio/metabolismo , Canais de Sódio/química , Canais de Sódio/genética , Relação Estrutura-Atividade , Transfecção , Ubiquitina-Proteína Ligases/metabolismo
6.
Am J Physiol Renal Physiol ; 289(1): F107-16, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15769939

RESUMO

Amiloride-sensitive epithelial sodium channels (ENaC) are responsible for transepithelial Na(+) transport in the kidney, lung, and colon. The channel consists of three subunits (alpha, beta, and gamma). In Madin-Darby canine kidney (MDCK) cells and Xenopus laevis oocytes transfected with all three ENaC subunits, neural precursor cell-expressed developmentally downregulated protein (Nedd4-2) promotes ubiquitin conjugation of ENaC. For native proteins in some cells, ubiquitin conjugation is a signal for their degradation by the ubiquitin-proteasome pathway, whereas in other cell types ubiquitin conjugation is a signal for endocytosis and lysosomal protein degradation. When ENaC are transfected into MDCK cells, ubiquitin conjugation leads to lysosomal degradation. In this paper, we characterize the involvement of the ubiquitin-proteasome proteolytic pathway in the regulation of functional ENaC in untransfected renal A6 cells expressing native ENaC subunits. In contrast to transfected cells, we show that total cellular alpha-, beta-, and gamma-ENaC subunits are polyubiquitinated and that ubiquitin conjugation of subunits increases when the cells are treated with a proteasome inhibitor. We show that Nedd4-2 is associated with alpha- and beta-subunits and is associated with the apical membrane. We also show the Nedd4-2 can regulate the number of functional ENaC subunits in the apical membrane. The results reported here suggest that the ubiquitin-proteasome proteolytic pathway is an important determinant of ENaC function in untransfected renal cells expressing endogenous ENaC.


Assuntos
Rim/metabolismo , Poliubiquitina/fisiologia , Canais de Sódio/metabolismo , Ubiquitina-Proteína Ligases/fisiologia , Animais , Linhagem Celular , Complexos Endossomais de Distribuição Requeridos para Transporte , Células Epiteliais/metabolismo , Canais Epiteliais de Sódio , Rim/citologia , Ubiquitina-Proteína Ligases Nedd4 , Proteínas de Xenopus , Xenopus laevis
7.
Am J Physiol Renal Physiol ; 283(5): F1030-45, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12372779

RESUMO

We studied the cellular phosphatase inhibitors okadaic acid (OKA), calyculin A, and microcystin on the epithelial sodium channel (ENaC) in A6 renal cells. OKA increased the amiloride-sensitive current after approximately 30 min with maximal stimulation at 1-2 h. Fluctuation analysis of cell-attached patches containing a large number of ENaC yielded power spectra with corner frequencies in untreated cells almost two times as large as in cells pretreated for 30 min with OKA, implying an increase in single channel open probability (P(o)) that doubled after OKA. Single channel analysis showed that, in cells pretreated with OKA, P(o) and mean open time approximately doubled. Two other phosphatase inhibitors, calyculin A and microcystin, had similar effects on P(o) and mean open time. An analog of OKA, okadaone, that does not inhibit phosphatases had no effect. Pretreatment with 10 nM OKA, which blocks protein phosphatase 2A (PP2A) but not PP1 in mammalian cells, had no effect even though both phosphatases are present in A6 cells. Several proteins were differentially phosphorylated after OKA, but ENaC subunit phosphorylation did not increase. We conclude that, in A6 cells, there is an OKA-sensitive phosphatase that suppresses ENaC activity by altering the phosphorylation of a regulatory molecule associated with the channel.


Assuntos
Rim/enzimologia , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosfoproteínas Fosfatases/metabolismo , Canais de Sódio/metabolismo , Animais , Linhagem Celular , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Canais Epiteliais de Sódio , Ativação do Canal Iônico/fisiologia , Isomerismo , Rim/citologia , Toxinas Marinhas , Microcistinas , Ácido Okadáico/análogos & derivados , Ácido Okadáico/farmacologia , Oxazóis/farmacologia , Técnicas de Patch-Clamp/métodos , Peptídeos Cíclicos/farmacologia , Fosforilação , Proteína Quinase C/metabolismo , Proteína Fosfatase 2 , Canais de Sódio/química
8.
J Biol Chem ; 276(16): 12903-10, 2001 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-11278712

RESUMO

Amiloride-sensitive epithelial Na(+) channels (ENaC) are responsible for trans-epithelial Na(+) transport in the kidney, lung, and colon. The channel consists of three subunits (alpha, beta, gamma) each containing a proline rich region (PPXY) in their carboxyl-terminal end. Mutations in this PPXY domain cause Liddle's syndrome, an autosomal dominant, salt-sensitive hypertension, by preventing the channel's interactions with the ubiquitin ligase Neural precursor cell-expressed developmentally down-regulated protein (Nedd4). It is postulated that this results in defective endocytosis and lysosomal degradation of ENaC leading to an increase in ENaC activity. To show the pathway that degrades ENaC in epithelial cells that express functioning ENaC channels, we used inhibitors of the proteosome and measured sodium channel activity. We found that the inhibitor, MG-132, increases amiloride-sensitive trans-epithelial current in Xenopus distal nephron A6 cells. There also is an increase of total cellular as well as membrane-associated ENaC subunit molecules by Western blotting. MG-132-treated cells also have increased channel density in patch clamp experiments. Inhibitors of lysosomal function did not reproduce these findings. Our results suggest that in native renal cells the proteosomal pathway is an important regulator of ENaC function.


Assuntos
Cisteína Endopeptidases/metabolismo , Complexos Multienzimáticos/metabolismo , Canais de Sódio/metabolismo , Ubiquitinas/metabolismo , Sequência de Aminoácidos , Animais , Especificidade de Anticorpos , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Inibidores de Cisteína Proteinase/farmacologia , Canais Epiteliais de Sódio , Humanos , Cinética , Leupeptinas/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Modelos Biológicos , Dados de Sequência Molecular , Néfrons , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Complexo de Endopeptidases do Proteassoma , Subunidades Proteicas , Canais de Sódio/química , Canais de Sódio/genética , Urotélio/citologia , Urotélio/fisiologia , Xenopus laevis
9.
J Membr Biol ; 184(3): 313-9, 2001 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-11891557

RESUMO

Aldosterone maintains total organism sodium balance in all higher vertebrates. The level of sodium reabsorption is primarily determined by the action of aldosterone on epithelial sodium channels (ENaC) in the distal nephron. Recent work shows that, in an aldosterone-sensitive renal cell line (A6), aldosterone regulates sodium reabsorption by short- and long-term processes. In the short term, aldosterone regulates sodium transport by inducing expression of the small G-protein, K-Ras2A, by stimulating the activity of methyl transferase and S-adenosyl-homocysteine hydrolase to activate Ras by methylation, and, possibly, by subsequent activation by K-Ras2A of phosphatidylinositol phosphate-5-kinase (PIP-5-K) and phosphatidylinositol-3-kinase (PI-3-K), which ultimately activates ENaC. In the long term, aldosterone regulates sodium transport by altering trafficking, assembly, and degradation of ENaC.


Assuntos
Aldosterona/farmacologia , Células Epiteliais/metabolismo , Canais de Sódio/farmacologia , Sódio/farmacocinética , Aldosterona/metabolismo , Aldosterona/fisiologia , Animais , Anuros , Transporte Biológico/fisiologia , Membrana Celular/fisiologia , Condutividade Elétrica , Células Epiteliais/efeitos dos fármacos , Canais Epiteliais de Sódio , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Técnicas de Patch-Clamp/métodos , Canais de Sódio/farmacocinética , ATPase Trocadora de Sódio-Potássio/fisiologia
10.
J Mol Biol ; 301(1): 101-15, 2000 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-10926495

RESUMO

Since the initial report of the development of methodology to generate high-affinity digitalis-specific (digoxin) antibodies, these antibodies have proven extremely useful tools to monitor digoxin levels in digitalized patients and, as Fab fragments, to reverse toxic digoxin effects in life-threatening digoxin overdoses. These antibodies (both digoxin-specific and ouabain-specific) have been used extensively by investigators for the identification and characterization of putative endogenous digitalis-like factors. In this study, we used two well-characterized mouse anti-digoxin monoclonal antibodies (mAbs), designated 26-10 and 45-20, as binding templates with which to select short bacteriophage-displayed (pIII protein inserted) peptides that are capable of binding to these mAbs and mimicking the conformational structure of digoxin. Selective enrichment from two phage-displayed random peptide libraries enabled us to isolate and identify distinct 15 and 26 amino acid residue peptide inserts that bind with high avidity and idiotypic specificity to the selecting mAbs. Among these displayed inserts a subset was identified whose mAb binding is inhibited by digoxin and whose corresponding synthetic peptides inhibit phage binding. They, therefore, appear to bind at the mAbs digoxin-binding sites. These data provide the first clear evidence that short polypeptides can serve as surrogates for the low molecular mass hapten digoxin.


Assuntos
Anticorpos Monoclonais/imunologia , Digoxina/química , Digoxina/imunologia , Mimetismo Molecular , Biblioteca de Peptídeos , Peptídeos/química , Peptídeos/imunologia , Sequência de Aminoácidos , Animais , Afinidade de Anticorpos/imunologia , Especificidade de Anticorpos/imunologia , Bacteriófagos/efeitos dos fármacos , Bacteriófagos/genética , Bacteriófagos/metabolismo , Sítios de Ligação de Anticorpos/efeitos dos fármacos , Ligação Competitiva/efeitos dos fármacos , Proteínas do Capsídeo , Clonagem Molecular , Reações Cruzadas/imunologia , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/imunologia , Proteínas de Ligação a DNA/metabolismo , Digoxina/farmacologia , Ensaio de Imunoadsorção Enzimática , Humanos , Camundongos , Dados de Sequência Molecular , Mutagênese Insercional/genética , Peptídeos/genética , Peptídeos/farmacologia , Conformação Proteica , Desnaturação Proteica , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , ATPase Trocadora de Sódio-Potássio/metabolismo , Proteínas Virais de Fusão/química , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/imunologia , Proteínas Virais de Fusão/metabolismo
11.
Ginekol Pol ; 71(10): 1273-6, 2000 Oct.
Artigo em Polonês | MEDLINE | ID: mdl-11143936

RESUMO

Cysteine proteinase inhibitors (IPC) concentration was measured by the modified Barrett method using papaine in urine, amniotic fluid and serum obtained from the healthy labored women and from labored women in pregnancy complicated by EPH-gestosis. It was noticed the statistically significant increase in the IPC concentration in the material from the pregnant women with EPH-gestosis comparing to the women, which pregnancy had the physiologically normal course.


Assuntos
Inibidores de Cisteína Proteinase/análise , Pré-Eclâmpsia/metabolismo , Gravidez/metabolismo , Adulto , Líquido Amniótico/química , Inibidores de Cisteína Proteinase/sangue , Inibidores de Cisteína Proteinase/urina , Feminino , Humanos
12.
Am J Physiol ; 276(6): L1046-51, 1999 06.
Artigo em Inglês | MEDLINE | ID: mdl-10362730

RESUMO

Amiloride-sensitive Na+ transport by lung epithelia plays a critical role in maintaining alveolar Na+ and water balance. It has been generally assumed that Na+ transport is mediated by the amiloride-sensitive epithelial Na+ channel (ENaC) because molecular biology studies have confirmed the presence of ENaC subunits alpha, beta, and gamma in lung epithelia. However, the predominant Na+-transporting channel reported from electrophysiological studies by most laboratories is a nonselective, high-conductance channel that is very different from the highly selective, low-conductance ENaC reported in other tissues. In our laboratory, single-channel recordings from apical membrane patches from rat alveolar type II (ATII) cells in primary culture reveal a nonselective cation channel with a conductance of 20.6 +/- 1.1 pS and an Na+-to-K+ selectivity of 0.97 +/- 0.07. This channel is inhibited by submicromolar concentrations of amiloride. Thus there is some question about the relationship between the gene product observed with single-channel methods and the cloned ENaC subunits. We have employed antisense oligonucleotide methods to block the synthesis of individual ENaC subunit proteins (alpha, beta, and gamma) and determined the effect of a reduction in the subunit expression on the density of the nonselective cation channel observed in apical membrane patches on ATII cells. Treatment of ATII cells with antisense oligonucleotides inhibited the production of each subunit protein; however, single-channel recordings showed that only the antisense oligonucleotide targeting the alpha-subunit resulted in a significant decrease in the density of nonselective cation channels. Inhibition of the beta- and gamma-subunit proteins alone or together did not cause any changes in the observed channel density. There were no changes in open probability or other channel characteristics. These results support the hypothesis that the alpha-subunit of ENaC alone or in combination with some protein other than the beta- or gamma-subunit protein is the major component of lung alveolar epithelial cation channels.


Assuntos
Cátions/metabolismo , Canais Iônicos/efeitos dos fármacos , Canais Iônicos/metabolismo , Pulmão/metabolismo , Oligonucleotídeos Antissenso/farmacologia , Canais de Sódio/genética , Animais , Membrana Celular/metabolismo , Células Epiteliais/metabolismo , Canais Epiteliais de Sódio , Canais Iônicos/antagonistas & inibidores , Pulmão/citologia , Isoformas de Proteínas/genética , Ratos , Ratos Sprague-Dawley , Sódio/metabolismo
13.
JK Pract ; 6(1): 84-91, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-12295052

RESUMO

PIP: This article, intended for use by practitioners in India, summarizes the US Centers for Disease Control's recommendations for the management of sexually transmitted diseases (STDs). The STDs presented are chancroid, genital herpes, granuloma inguinale, lymphogranuloma venereum, syphilis, urethritis, chlamydia, gonococcal infection, bacterial vaginosis, trichomoniasis, vulvovaginal candidiasis, pelvic inflammatory disease, epididymitis, human papillomavirus infection, warts, hepatitis B, and ectoparasitic infections. For each STD, information is provided on treatment, follow up, and special circumstances such as pregnancy and concomitant HIV infection.^ieng


Assuntos
Centers for Disease Control and Prevention, U.S. , Diretrizes para o Planejamento em Saúde , Infecções Sexualmente Transmissíveis , Terapêutica , Ásia , Países em Desenvolvimento , Doença , Órgãos Governamentais , Índia , Infecções , Organizações , United States Public Health Service
14.
Protein Sci ; 2(12): 2103-11, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7507752

RESUMO

Monoclonal antibodies that bind native protein can generate considerable information about structure/function relationships, but identification of their epitopes can be problematic. Previously, monoclonal antibody M8-P1-A3 has been shown to bind to the catalytic (alpha) subunit of the Na+,K(+)-ATPase holoenzyme and the synthetic peptide sequence 496-HLLVMK*GAPER-506, which includes Lys 501 (K*), the major site for fluorescein-5'-isothiocyanate labeling of the Na+,K(+)-ATPase. This sequence region of alpha is proposed to comprise a portion of the enzyme's ATP binding domain (Taylor, W. R. & Green, N. W., 1989, Eur. J. Biochem. 179, 241-248). In this study we have determined M8-P1-A3's ability to recognize the alpha-subunit or homologous E1E2-ATPase proteins from different species and tissues in order to deduce the antibody's epitope. In addition the bacteriophage random peptide or "epitope" library, recently developed by Scott and Smith (1990, Science 249, 386-390) and Devlin et al. (Devlin, J. J., Panganiban, L. C., & Devlin, P. E., 1990, Science 249, 404-406), has served as a convenient technique to confirm the species-specificity mapping data and to determine the exact amino acid requirements for antibody binding. The M8-P1-A3 epitope was found to consist of the five amino acid 494-PRHLL-498 sequence stretch of alpha, with residues PRxLx being critical for antibody recognition.


Assuntos
Trifosfato de Adenosina/metabolismo , Epitopos/imunologia , Fragmentos de Peptídeos/imunologia , ATPase Trocadora de Sódio-Potássio/imunologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Galinhas , Inovirus/genética , Medula Renal/enzimologia , Dados de Sequência Molecular , Coelhos , Ratos , Proteínas Recombinantes/imunologia , Ovinos , ATPase Trocadora de Sódio-Potássio/genética , Especificidade da Espécie , Propriedades de Superfície , Suínos , Torpedo , Xenopus
16.
Biotechnol Bioeng ; 34(8): 1050-7, 1989 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-18588198

RESUMO

Pyrococcus furiosus represents one of the most important hyperthermophilic bacteria isolated thus far because of its relatively high cell yields and rapid growth rates. Pyrococcus furiosus exhibits several interesting growth characteristics, especially in terms of biotic gas production, which were examined in this study. In the presence of elemental sulfur, both carbon dioxide and hydrogen sulfide production appeared to be strongly growth associated, while no significant hydrogen production was observed. In the absence of sulfur, hydrogen and carbon dioxide were produced by the organism and hydrogen inhibition was observed. The addition of elemental sulfur to the medium apparently eliminated, hydrogen inhibition as growth proceeded normally even when hydrogen was added to the gas phase. Also, no apparent substrate limitation or toxic product could be attributed to the cessation of growth as cell growth in spent media was at least as good as in fresh media. An unstructured growth model was used to correlate growth and gas production for P. furiosus in complex seawater-based media at 98 degrees C both in the absence and presence of elemental sulfur. The model was shown to be useful for examining some of the observations made in this study.

17.
Contraception ; 23(2): 211-25, 1981 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-6786828

RESUMO

Six normally menstruating women were inserted each with a single silastic implant-D releasing norethindrone acetate (NETA). The levels of endogenous hormones, FSH, LH, E2 and progesterone, were estimated by radioimmunoassay (RIA) procedures in the control and treatment cycles. In addition, the levels of drug in the serum as norethindrone (NET) which is a major metabolite of NETA were also estimated by RIA procedures in the treatment cycles. In all, 12 treatment cycles were studied. In the initial treatment cycles (1st/2nd or 3rd), the serum NET levels were either 1 ng/ml or above. The LH and FSH showed either normal or suppressed mid-cycle peaks, but the progesterone levels were completely suppressed. In the sixth treatment cycles, the serum NET levels were either 0.5 ng/ml or below. The FSH and LH mid-cycle peaks were lower but distinct while the luteal progesterone levels were of normal ovulatory type. These studies lead us to the conclusion that a serum level of NET of the order of 1 ng/ml is required to bring about suppression of luteal progesterone, either as a result of direct action on the ovary or through suppression of pituitary gonadotropins. When the serum level falls to 0.5 ng/ml or below, the suppressive effect is removed and ovulatory pattern of progesterone returns.


PIP: 6 normally menstruating women were each inserted with a single silastic implant-D releasing (NETA) norethindrone acetate. The levels of endogenous hormones, FSH, LH, E2, and progesterone, were estimated by (RIA) radioimmunoassay procedures in the control and treatment cycles. In addition, the levels of drug in the serum as (NET) norethindrone which is a major metabolite of NETA were also estimated by RIA procedures in the treatment cycles. In all, 12 treatment cycles were studied. In the initial treatment cycles (1st/2nd or 3rd), the serum NET levels were either 1 ng/ml or above. The LH and FSH showed either normal or suppressed midcycle peaks, but the progesterone levels were completely suppressed. In the 6th treatment cycle, the serum NET levels were either 0.5 ng/ml or below. The FSH and LH midcycle peaks were lower but distinct while the luteal progesterone levels were of normal ovulatory type. These studies lead us to the conclusion that a serum level of NET of the order of 1 ng/ml is required to bring about suppression of luteal progesterone, either as a result of direct action on the ovary or through suppression of pituitary gonadotropins. When the serum level falls to 0.5 ng/ml or below, the suppressive effect is removed and ovulatory pattern of progesterone returns.


Assuntos
Estradiol/sangue , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Noretindrona/análogos & derivados , Progesterona/sangue , Implantes de Medicamento , Feminino , Humanos , Menstruação , Noretindrona/administração & dosagem , Noretindrona/sangue , Acetato de Noretindrona , Radioimunoensaio , Fatores de Tempo
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