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1.
Surg Endosc ; 23(8): 1724-32, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18830747

RESUMO

BACKGROUND: A group of patients with type 2 diabetes mellitus (T2DM) and body mass index (BMI) 20-34 kg/m(2) were submitted to laparoscopic interposition of a segment of ileum into the proximal jejunum or into the proximal duodenum associated to a sleeve gastrectomy. The objective of this study is to evaluate the hormonal changes in the pre- and postoperative period. MATERIALS AND METHODS: Hormonal evaluation was done in 58 patients operated between April 2005 and July 2006. Mean age was 51.4 years (40-66 years). Mean BMI was 28.2 (20-34.8) kg/m(2). All patients had had the diagnosis of T2DM for at least 3 years. Mean duration of T2DM was 9.6 years (3-22 years). Two techniques were performed, consisting of different combinations of ileal interposition (II) associated to a sleeve gastrectomy (SG). The following hormones were assayed in the pre- and postoperative period (mean 16 months) at the baseline and following specific food stimulation (30, 60, 120 min): glucogen-like protein 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), insulin, glucagon, C-peptide, amylin, cholecystokinin (CCK), pancreatic polypeptide (PPP), somatostatin, peptide YY (PYY), ghrelin, adiponectin, resistin, leptin, and interleukin-6 (IL-6). RESULTS: Thirty patients had II associated to sleeve gastrectomy (II-SG) and 28 had II with diverted sleeve gastrectomy (II-DSG). GLP1 exhibited an important rise following the two operations, especially after II-DSG (p < 0.001). GIP also exhibited an important rise, with both II-SG and II-DSG being equally effective (p < 0.001). Insulin and amylin showed a significant rise at 30 min. Glucagon decreased slightly. CCK measurements were very low after II-DSG. PPP was also slightly altered by the II-DSG. PYY showed an important increase with both operations (p < 0.001). Ghrelin showed a significant decrease following the two operations (p < 0.001). Somatostatin and IL-6 were not affected (p = 0.632). Both leptin and resistin blood levels decreased. Adiponectin showed a slight increase. Mean postoperative follow-up was 19.2 months. Both II-SG and II-DSG were effective in achieving adequate glycemic control (91.2%). CONCLUSIONS: There was a significant hormonal change following laparoscopic ileal interposition. These alterations may explain the promising good results associated to these operations for the treatment of T2DM in the nonmorbidly obese population.


Assuntos
Diabetes Mellitus Tipo 2/cirurgia , Duodeno/cirurgia , Gastrectomia/métodos , Hormônios Gastrointestinais/sangue , Íleo/cirurgia , Jejuno/cirurgia , Laparoscopia/métodos , Hormônios Peptídicos/sangue , Adulto , Idoso , Anastomose Cirúrgica , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Seguimentos , Hormônios Gastrointestinais/metabolismo , Hemoglobinas Glicadas/análise , Humanos , Interleucina-6/sangue , Interleucina-6/metabolismo , Masculino , Pessoa de Meia-Idade , Sobrepeso , Hormônios Peptídicos/metabolismo , Período Pós-Operatório
2.
Surg Endosc ; 23(6): 1313-20, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18830750

RESUMO

BACKGROUND: The objective of this study is to evaluate the clinical results of the laparoscopic interposition of a segment of ileum into the proximal duodenum associated to a sleeve gastrectomy (II-DSG) in order to treat patients with type 2 diabetes mellitus (T2DM) and body mass index (BMI) 21-29 kg/m2. PATIENTS AND METHODS: The laparoscopic procedure was performed in 69 patients, 22 female and 47 male. Mean age was 51 years (range 41-63 years). Mean BMI was 25.7 (21.8-29.2) kg/m2. All patients had the diagnosis of T2DM for at least 3 years and evidence of stable treatment with oral hypoglycemic agents and or insulin for at least 12 months. Insulin therapy was used by 44% of the patients. Mean duration of T2DM was 11 years (range 3-18 years). Dyslipidemia was diagnosed in 72.5% and hypertension in 66.7%. Nephropathy was characterized in 29% of the patients, retinopathy in 26.1%, and neuropathy in 24.6%. RESULTS: Overall, 95.7% of the patients achieved adequate glycemic control (Hb(A1c) < 7%) without antidiabetic medication. Hb(A1c) below 6% was achieved by 65.2%. Mean postoperative follow-up was 21.7 months (range 7-42 months). Mean postoperative BMI was 21.8 kg/m2. There was no conversion to open surgery. Median hospital stay was 3.4 days (range 2-58 days). Major postoperative complications were diagnosed in 7.3%. There was no mortality. Fasting glycemia decreased from a mean of 218 to 102 mg/dl, postprandial glycemia from 305 to 141 mg/dl, and homeostasis model assessment of insulin resistance (Homa-IR) from 5.2 to 0.77. All associated comorbidities and complications related to T2DM had significant improvement or control. Arterial hypertension was controlled in 91.3%. Macroalbuminuria was no longer observed. Microalbuminuria resolved in 87.5% of patients. Hypercholesterolemia was normalized in 95% and hypertriglyceridemia in 92% of patients. CONCLUSIONS: Laparoscopic II-DSG was an effective operation in controlling T2DM in a nonobese (BM < 30 kg/m2) population. Associated diseases and related complications were also improved. A longer follow-up period is needed.


Assuntos
Diabetes Mellitus Tipo 2/cirurgia , Duodeno/cirurgia , Gastrectomia/métodos , Íleo/cirurgia , Adulto , Anastomose Cirúrgica , Glicemia/metabolismo , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Seguimentos , Humanos , Laparoscopia/métodos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento
3.
Surg Endosc ; 22(12): 2670-8, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18347866

RESUMO

BACKGROUND: Metabolic syndrome refers to risk factors for cardiovascular disease. Hyperglycemia is a critical component contributing to the predictive power of the syndrome. This study aimed to evaluate the results from the laparoscopic interposition of an ileum segment into the proximal jejunum for the treatment of metabolic syndrome in patients with type 2 diabetes mellitus and a body mass index (BMI) lower than 35. METHODS: Laparoscopic procedures were performed for 60 patients (24 women and 36 men) with a mean age of 51.7 +/- 6.4 years (range, 27-66 years) and a mean BMI of 30.1 +/- 2.7 (range, 23.6-34.4). All the patients had a diagnosis of type 2 diabetes mellitus (T2DM) given at least 3 years previously and evidence of stable treatment using oral hypoglycemic agents, insulin, or both for at least 12 months. The mean duration of type 2 diabetes mellitus was 9.6 +/- 4.6 years (range, 3-22 years). Metabolic syndrome was diagnosed for all 60 patients. Arterial hypertension was diagnosed for 70% of the patients (mean number of drugs, 1.6) and hypertriglyceridemia for 70%. High-density lipoprotein was altered in 51.7% of the patients and the abdominal circumference in 68.3%. Two techniques were performed: ileal interposition (II) into the proximal jejunum and sleeve gastrectomy (II-SG) or ileal interposition associated with a diverted sleeve gastrectomy (II-DSG). RESULTS: The II-SG procedure was performed for 32 patients and the II-DSG procedure for 28 patients. The mean postoperative follow-up period was 7.4 months (range, 3-19 months). The mean BMI was 23.8 +/- 4.1 kg/m(2), and 52 patients (86.7%) achieved adequate glycemic control. Hypertriglyceridemia was normalized for 81.7% of the patients. An high-density lipoprotein level higher than 40 for the men and higher than 50 for the women was achieved by 90.3% of the patients. The abdominal circumference reached was less than 102 cm for the men and 88 cm for the women. Arterial hypertension was controlled in 90.5% of the patients. For the control of metabolic syndrome, II-DSG was the more effective procedure. CONCLUSIONS: Laparoscopic II-SG and II-DSG seem to be promising procedures for the control of the metabolic syndrome and type 2 diabetes mellitus. A longer follow-up period is needed.


Assuntos
Diabetes Mellitus Tipo 2/cirurgia , Derivação Gástrica/métodos , Íleo/cirurgia , Jejuno/cirurgia , Laparoscopia/métodos , Síndrome Metabólica/cirurgia , Adulto , Idoso , Glicemia/análise , Pressão Sanguínea , Índice de Massa Corporal , Colesterol/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Gastrectomia/métodos , Gastrectomia/estatística & dados numéricos , Derivação Gástrica/estatística & dados numéricos , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Humanos , Íleo/fisiopatologia , Insulina/sangue , Laparoscopia/estatística & dados numéricos , Masculino , Síndrome Metabólica/sangue , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Triglicerídeos/sangue
4.
Surg Endosc ; 22(3): 706-16, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17704886

RESUMO

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a common disease with numerous complications. Bariatric surgery is an efficient procedure for controlling T2DM in morbidly obese patients. In T2DM, the incretin effect is either greatly impaired or absent. This study aimed to evaluate the preliminary results from interposing a segment of ileum into the proximal jejunum associated with a sleeve or diverted sleeve gastrectomy to control T2DM in patients with a body mass index (BMI) less than 35 kg/m(2). METHODS: For this study, 39 patients (16 women and 23 men) underwent two laparoscopic procedures comprising different combinations of ileal interposition into the proximal jejunum via a sleeve or diverted sleeve gastrectomy. The mean age of these patients was 50.3 years (range, 36-66 years). The mean BMI was 30.1 kg/m(2) (range, 23.4-34.9 kg/m(2)). All the patients had a diagnosis of T2DM that had persisted for at least 3 years and evidence of stable treatment with oral hypoglycemic agents or insulin for at least 12 months. The mean duration of T2DM was 9.3 years (range, 3-22 years). RESULTS: The mean operative time was 185 min, and the median hospital stay was 4.3 days. Four major complications occurred in the short term (30-days), and the mortality rate was 2.6%. The mean postoperative follow-up period was 7 months (range, 4-16 months), and the mean percentage of weight loss was 22%. The mean postoperative BMI was 24.9 kg/m(2) (range, 18.9-31.7 kg/m(2)). An adequate glycemic control was achieved for 86.9% of the patients, and 13.1% had important improvement. The patients whose glycemia was not normalized were using a single oral hypoglycemic agent. No patient needed insulin therapy postoperatively. All the patients except experienced normalization of their cholesterol levels. Targeted triglycerides levels were achieved by 71% of the patients, and hypertension was controlled for 95.8%. CONCLUSIONS: The laparoscopic ileal interposition via either a sleeve gastrectomy or diverted sleeve gastrectomy seems to be a promising procedure for the control of T2DM and the metabolic syndrome. A longer follow-up period is needed.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Derivação Gástrica/métodos , Laparoscopia/métodos , Obesidade Mórbida/epidemiologia , Obesidade Mórbida/cirurgia , Adulto , Idoso , Anastomose Cirúrgica/métodos , Glicemia/análise , Índice de Massa Corporal , Estudos de Coortes , Comorbidade , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Seguimentos , Humanos , Íleo/cirurgia , Laparoscopia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/diagnóstico , Complicações Pós-Operatórias/fisiopatologia , Probabilidade , Qualidade de Vida , Medição de Risco , Estômago/cirurgia , Resultado do Tratamento , Redução de Peso
5.
Biochem Biophys Res Commun ; 289(2): 630-3, 2001 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-11716522

RESUMO

Dg ferredoxin gene was cloned using the polymerase chain reaction (PCR), inserted into vector pT7-7, and overexpressed in Escherichia coli (E. coli) grown in aerobic media. The recombinant protein is a dimer and contains a [3Fe-4S] cluster per monomer. EPR and (1)H NMR data of recombinant and wild-type protein are compared.


Assuntos
Desulfovibrio/química , Ferredoxinas/química , Proteínas Recombinantes/química , Clonagem Molecular , Dimerização , Espectroscopia de Ressonância de Spin Eletrônica , Eletroforese em Gel de Poliacrilamida , Escherichia coli/metabolismo , Ferredoxinas/genética , Ferro/metabolismo , Espectroscopia de Ressonância Magnética , Oxigênio/metabolismo , Reação em Cadeia da Polimerase , Proteínas Recombinantes/metabolismo , Espectrofotometria , Enxofre/metabolismo , Temperatura , Raios Ultravioleta
6.
FEBS Lett ; 505(2): 325-31, 2001 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-11566198

RESUMO

The mitochondrial import of 5-aminolevulinate synthase (ALAS), the first enzyme of the mammalian heme biosynthetic pathway, requires the N-terminal presequence. The 49 amino acid presequence transit peptide (psALAS) for murine erythroid ALAS was chemically synthesized, and circular dichroism and (1)H nuclear magnetic resonance (NMR) spectroscopies used to determine structural elements in trifluoroethanol/H(2)O solutions and micellar environments. A well defined amphipathic alpha-helix, spanning L22 to F33, was present in psALAS in 50% trifluoroethanol. Further, a short alpha-helix, defined by A5-L8, was also apparent in the 26 amino acid N-terminus peptide, when its structure was determined in sodium dodecyl sulfate. Heme inhibition of ALAS mitochondrial import has been reported to be mediated through cysteine residues in presequence heme regulatory motifs (HRMs). A UV/visible and (1)H NMR study of hemin and psALAS indicated that a heme-peptide interaction occurs and demonstrates, for the first time, that heme interacts with the HRMs of psALAS.


Assuntos
5-Aminolevulinato Sintetase/química , 5-Aminolevulinato Sintetase/metabolismo , Heme/química , Heme/metabolismo , Sequência de Aminoácidos , Aminoácidos/química , Animais , Dicroísmo Circular , Espectroscopia de Ressonância Magnética , Camundongos , Mitocôndrias/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Peptídeos/química , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Espectrofotometria
7.
J Pediatr Surg ; 36(9): E17, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11528634

RESUMO

Minimal access surgery is an alternative to open surgery in esophageal resections. Thoracoscopic surgery has been utilized for both benign and malignant esophageal lesions and is a complex and challenging surgical procedure that can provide some benefits in comparison with open thoracotomy. Many studies have described laparoscopic or thoracoscopic-assisted esophagectomy in adults. So far, to the best of our knowledge, there is no study about thoracoscopic esophagectomy in children. This report describes 2 pediatric cases of benign esophageal lesions: one stricture after accidental ingestion of caustic soda and one esophageal stenosis after thyroglossal duct complication. Both patients were submitted to thoracoscopic esophagectomy combined with laparotomy and open cervical exploration with success. This procedure presents some potential advantages when compared with open esophagectomy: shorter hospital stay, precise dissection of mediastinal structures, less postoperative pain, less blood loss during surgery and less long-term discomfort. In our cases, thoracoscopic surgery for children showed the same benefits as in adults. Although very feasible, it should not be attempted without sufficient training and should be carried out only in specialized medical centers and by surgeons with adequate experience with open esophagectomy.


Assuntos
Queimaduras Químicas/cirurgia , Cáusticos/efeitos adversos , Esofagectomia/métodos , Esôfago/lesões , Toracoscopia/métodos , Cisto Tireoglosso/cirurgia , Acidentes Domésticos , Queimaduras Químicas/etiologia , Criança , Pré-Escolar , Esôfago/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Cirurgia Torácica Vídeoassistida/métodos , Cisto Tireoglosso/diagnóstico , Resultado do Tratamento
8.
J Biol Inorg Chem ; 5(6): 748-60, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11129002

RESUMO

The enthalpy and entropy changes associated with protein reduction (deltaHdegrees,(rc), deltaSdegrees,(rc)) were determined for a number of low-potential iron-sulfur proteins through variable temperature direct electrochemical experiments. These data add to previous estimates making available, overall, the reduction thermodynamics for twenty species from various sources containing all the different types of metal centers. These parameters are discussed with reference to structural data and calculated electrostatic metal-environment interaction energies, and redox properties of model complexes. This work, which is the first systematic investigation on the reduction thermodynamics of Fe-S proteins, contributes to the comprehension of the determinants of the differences in reduction potential among different protein families within a novel perspective. Moreover, comparison with analogous data obtained previously for electron transport (ET) metalloproteins with positive reduction potentials, i.e., cytochromes c, blue copper proteins, and HiPIPs, helps our understanding of the factors controlling the reduction potential in ET species containing different metal cofactors. The main results of this work can be summarized as follows.


Assuntos
Proteínas Ferro-Enxofre/química , Desulfovibrio/química , Transporte de Elétrons , Oxirredução , Termodinâmica
9.
J Biol Inorg Chem ; 4(4): 421-30, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10555576

RESUMO

The use of standard 2D NMR experiments in combination with 1D NOE experiments allowed the assignment of 51 of the 58 spin systems of oxidised [3Fe4S] ferredoxin isolated from Desulfovibrio gigas. The NMR solution structure was determined using data from 1D NOE and 2D NOESY spectra, as distance constraints, and information from the X-ray structure for the spin systems not detected by NMR in torsion angle dynamics calculations to produce a family of 15 low target function structures. The quality of the NMR family, as judged by the backbone r.m.s.d. values, was good (0.80 A), with the majority of phi/psi angles falling within the allowed region of the Ramachandran plot. A comparison with the X-ray structure indicated that the overall global fold is very similar in solution and in the solid state. The determination of the solution structure of ferredoxin II (FdII) in the oxidised state (FdIIox) opens the way for the determination of the solution structure of the redox intermediate state of FdII (FdII(int)), for which no X-ray structure is available.


Assuntos
Desulfovibrio/química , Ferredoxinas/química , Ferredoxinas/metabolismo , Sequência de Aminoácidos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Oxirredução , Conformação Proteica , Estrutura Secundária de Proteína , Soluções
10.
Biochem Biophys Res Commun ; 229(2): 524-30, 1996 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-8954931

RESUMO

A 7Fe ferredoxin, isolated from the marine denitrifier Pseudomonas nautica strain 617, was characterized. The NH2-terminal sequence analysis, performed until residue number 56, shows a high similarity with the 7Fe ferredoxins isolated from Azotobacter vinelandii, Pseudomonas putida, and Pseudomonas stutzeri. EPR and NMR spectroscopies identify the presence of both [3Fe-4S] and [4Fe-4S] clusters, with cysteinyl coordination. The electrochemical studies on [Fe-S] clusters show that a fast diffusion-dominated electron transfer, promoted by Mg(II), takes place between the ferredoxin and the glassy carbon electrode. Square wave voltammetry studies gave access to the electrosynthesis of a 4Fe center formed within the [3Fe-4S] core. The [3Fe-4S] cluster exhibited two reduction potentials at -175 and -680 +/- 10 mV and the [4Fe-4S] cluster was characterized by an unusually low reduction potential of -715 +/- 10 mV, at pH 7.6


Assuntos
Ferredoxinas/química , Pseudomonas/química , Sequência de Aminoácidos , Eletroquímica , Espectroscopia de Ressonância de Spin Eletrônica , Ferredoxinas/isolamento & purificação , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos
11.
J Clin Pathol ; 47(5): 461-3, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-8027401

RESUMO

A case of a 58 year old woman with a chronic lymphoproliferative disorder of unusual clinical presentation, disease course, and immunophenotype is presented. At diagnosis she had severe anaemia, moderate lymphocytosis with some cells having prolymphocytoid features and a normal platelet count. A clinical examination yielded negative results. Only anaemia related symptoms were found and the patient became blood transfusion dependent. Both the lymphocytosis and the proportion of prolymphocytoid cells rose insidiously and thrombocytopenia developed later during the course of the disease. Three years later, the patient had a white cell count of 269 x 10(9)/l almost exclusively of prolymphocytoid cells and the bone marrow was diffusely infiltrated. She was refractory to chemotherapy and the anaemia did not improve after treatment with cyclosporine. Lymphoid cells were positive for cytoplasmatic CD3, HLA-Dr, CD34, CD38, CD7, CD56, CD13, CD33 and CD65. Membrane alpha beta and gamma delta T cell receptors (TCRs) were not expressed and the beta chain TCR gene was in germline configuration. Other membrane T, B, natural killer, and myelomonocytic markers were negative. Karyotype analysis was tried several times but metaphases were not obtained, even after stimulation with T cell mitogens.


Assuntos
Antígenos de Neoplasias/análise , Leucemia Prolinfocítica/imunologia , Anemia/etiologia , Antígenos CD/análise , Doença Crônica , Feminino , Humanos , Imunofenotipagem , Leucemia Prolinfocítica/complicações , Leucemia Prolinfocítica/patologia , Pessoa de Meia-Idade
12.
J Biol Chem ; 269(11): 8052-8, 1994 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-8132528

RESUMO

Desulfovibrio gigas ferredoxin II (FdII) is a small protein (alpha 4 subunit structure as isolated; M(r) approximately 6400 per subunit; 6 cysteine residues) containing one Fe3S4 cluster per alpha-subunit. The x-ray structure of FdII has revealed a disulfide bridge formed by Cys-18 and Cys-42 approximately 13 A away from the center of the cluster; moreover, the x-ray structure indicates that Cys-11 forms a disulfide bridge with a methanethiol. In the oxidized state, FdIIoxm the 1H NMR spectra, exhibit four low-field contact-shifted resonances at 29, 24, 18, and 15.5 ppm whereas the reduced state, FdIIR (S = 2), yields two features at +18.5 and -11 ppm. In the course of studying the redox behavior of FdII, we have discovered a stable intermediate, FdIIint, that yields 1H resonances at 24, 21.5, 21, and 14 ppm. This intermediate appears in the potential range where the cluster (E'0 approximately -130 mV) is reduced from the [Fe3S4]1+ to the [Fe3S4]0 state. FdIIint is observed during reductive titrations with dithionite or hydrogen/hydrogenase or after partial oxidation of FdIIR by 2,6-dichlorophenolindophenol or air. Our studies show that a total of three electrons per alpha-subunit are transferred to FdII. Our experiments demonstrate the absence of a methanethiol-Cys-11 linkage in our preparations, and we propose that two of the three electrons are used for the reduction of the disulfide bridge. Mössbauer (and EPR) studies show that the Fe3S4 cluster of FdIIint is at the same oxidation level as FdIIox, but indicate some changes in the exchange couplings among the three ferric sites. Our data suggest that the differences in the NMR and Mössbauer spectra of FdIIox and FdIIint result from conformational changes attending the breaking or formation of the disulfide bridge. The present study suggests that experiments be undertaken to explore an in vivo redox function for the disulfide bridge.


Assuntos
Desulfovibrio/metabolismo , Ferredoxinas/química , Ferredoxinas/metabolismo , Dissulfetos/metabolismo , Hidrogênio , Cinética , Espectroscopia de Ressonância Magnética/métodos , Oxirredução , Conformação Proteica , Espectroscopia de Mossbauer/métodos , Compostos de Sulfidrila/metabolismo
13.
J Inorg Biochem ; 53(3): 219-34, 1994 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-8133257

RESUMO

The same polypeptide chain (58 amino acids, 6 cysteines) is used to build up two ferredoxins in Desulfovibrio gigas a sulfate reducing organism. Ferredoxin II (FdII) contains a single [Fe3S4] core and ferredoxin I (FdI) mainly a [Fe4S4] core. The [Fe3S4] core can readily be interconverted into a [Fe4S4] complex (J.J.G. Moura, I. Moura, T.A. Kent, J.D. Lipscomb, B.H. Huynh, J. LeGall, A.V. Xavier, and E. Munck, J. Biol. Chem. 257, 6259 (1982)). This interconversion process suggested that the [Fe3S4] core could be used as a synthetic precursor for the formation of heterometal clusters. Co, Zn, Cd, and Ni derivatives were produced (I. Moura, J.J.G. Moura, E. Munck, V. Papaephthymiou, and J. LeGall, J. Am. Chem. Soc. 108, 349 (1986), K. Sureurs, E. Munck, I. Moura, J.J.G. Moura, and J. LeGall, J. Am. Chem. Soc. 109, 3805 (1986), and A.L. Macedo, I. Moura, J.J.G. Moura, K. Surerus, and E. Munck, unpublished results). The redox properties of a series of heterometal clusters (MFe3S4] are assessed using direct electrochemistry (square wave voltammetry--SWV) promoted by Mg(II) at a glassy carbon electrode (derivatives: Cd (-495 mV), Fe (-420 mV), Ni (-360 mV), and Co (-245 mV) vs normal hydrogen electrode (NHE)). In parallel, the electrochemical behavior (cyclic voltammetry--CV, differential pulse voltammetry--DPV and SWV) of FdI and FdII were investigated as well as the cluster interconversion process. In addition to the +1/0 (3Fe cluster) and +2/+1 (4Fe cluster) redox transitions, a very negative redox step, at -690 mV, was detected for the 3Fe core, reminiscent of a postulated further 2e- reduction step, as proposed for D. africanus ferredoxin III by F.A. Armstrong, S.J. George, R. Cammack, E.C. Hatchikian, and A.J. Thomson, Biochem. J. 264, 265 (1989). The electrochemical redox potential values are compared with those determined by independent methods (namely by electron paramagnetic resonance (EPR) and visible spectroscopy).


Assuntos
Desulfovibrio/química , Ferredoxinas/química , Eletroquímica , Espectroscopia de Ressonância de Spin Eletrônica , Compostos Ferrosos/química , Oxirredução , Espectrofotometria
15.
Ann Surg ; 204(2): 148-53, 1986 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3090954

RESUMO

From 1977 to 1983, 94 patients with esophageal varices and gastrointestinal bleeding secondary to mansonic schistosomiasis were entered into a prospective randomized trial comparing the three operations mainly used in Brazil: esophagogastric devascularization associated with splenectomy (EGDS, 32 patients), classical splenorenal shunt (SRS, 32 patients), and distal splenorenal shunt (DSRS, 30 patients). The randomization was interrupted because of a significant incidence of portosystemic encephalopathy (PSE) in the SRS group (26%), as compared to the DSRS (7%) and EGDS (0%) groups. The rate of rebleeding was the same in the three groups, but the rate of failure, as defined by the presence of technical problems, postoperative complications, or death, was significantly higher in the SRS group. This 2-year follow-up shows that SRS should be abandoned in hepatosplenic schistosomiasis and that a comparison between DSRS and EGDS with a longer follow-up is urgently needed.


Assuntos
Hipertensão Portal/cirurgia , Hepatopatias Parasitárias/complicações , Esquistossomose mansoni/complicações , Adulto , Ensaios Clínicos como Assunto , Esôfago/irrigação sanguínea , Feminino , Seguimentos , Hemorragia Gastrointestinal/etiologia , Humanos , Hipertensão Portal/etiologia , Masculino , Métodos , Transtornos Neurocognitivos/etiologia , Complicações Pós-Operatórias , Distribuição Aleatória , Recidiva , Fluxo Sanguíneo Regional , Esplenopatias/complicações , Derivação Esplenorrenal Cirúrgica , Estômago/irrigação sanguínea
18.
Surg Gynecol Obstet ; 156(6): 802-3, 1983 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6857464
20.
Rev. paul. med ; 101(3): 96-9, 1983.
Artigo em Português | LILACS | ID: lil-13790

RESUMO

Operaram-se 10 pacientes portadores de cirrose hepatica e calculose biliar. No pos-operatorio nao se observou mortalidade dade e as complicacoes mais frequentes incluiram: vazamento de ascite pelo orificio de drenagem, eventracao e confusao mental transitoria. Houve mortalidade tardia em um paciente, por evolucao de hepatoma no 4o. mes de seguimento, e em outro, por peritonite bacteriana espontanea no 7o.mes. Sugere-se uma serie de cuidados que devem ser tomados para aprimorar os resultados: diagnostico precoce da patologia por ultra-som, controle pre-operatorio da ascite, anestesia peridural continua, incisao transversa alta, hemostasia rigorosa do leito vesicular, evitar o uso de drenos na cavidade ou na via biliar e restricao de sodio, com administracao liberal de coloides no pos-operatorio


Assuntos
Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Colecistectomia , Cirrose Hepática , Colelitíase
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