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1.
Med J Malaysia ; 77(4): 494-499, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35902941

RESUMO

BACKGROUND: Duodenal eosinophilia is postulated to play a key role in the pathogenesis of functional dyspepsia, a common condition responsible for considerable impairment of quality of life. Our objective was to evaluate the relative strength of the associations between duodenal eosinophilia, functional dyspepsia, symptomatic erosive gastroesophageal reflux disease (GERD), the presence of co-morbidities, and a number of other variables. METHODS: Eosinophil counts of archived endoscopic duodenal biopsies of 289 subjects were determined by a pathologist blinded to the clinical data. Duodenal eosinophilia was defined by a count of more than 15 per 5 high power fields. Clinical charts were reviewed by a gastroenterologist blinded to the histology review. RESULTS: In the study sample, the primary diagnosis was functional dyspepsia (undifferentiated by subtypes) in 45, symptomatic erosive GERD in 29, gall stone disease in 17, irritable bowel syndrome in 23, and an alternative or undetermined diagnosis in 175 subjects, respectively. On logistic regression analyses, eosinophil counts were positively associated with symptomatic erosive GERD (Odds Ratio, OR 1.03, 95% Confidence Interval, 95%CI: 1.00, 1.05; p=0.035) but not functional dyspepsia. Pre-defined duodenal eosinophilia was associated with symptomatic erosive gastro-oesophageal reflux disease (OR 3.36, 95%CI 1.18,-9.60; p=0.023), the presence of co-morbidities (OR 2.00, 95%CI 1.10, 3.62; p=0.022), and Chinese (as compared to Malay and Indian) ethnicity but not with either functional dyspepsia, irritable bowel syndrome, gallstone disease, Helicobacter pylori infection, or gender. CONCLUSION: Duodenal eosinophilia was associated with symptomatic erosive GERD, the presence of co-morbidities, and Chinese ethnicity but not with undifferentiated functional dyspepsia.


Assuntos
Dispepsia , Eosinofilia , Refluxo Gastroesofágico , Infecções por Helicobacter , Helicobacter pylori , Síndrome do Intestino Irritável , Dispepsia/diagnóstico , Dispepsia/epidemiologia , Dispepsia/patologia , Eosinofilia/complicações , Eosinofilia/epidemiologia , Eosinofilia/patologia , Etnicidade , Refluxo Gastroesofágico/complicações , Refluxo Gastroesofágico/epidemiologia , Infecções por Helicobacter/complicações , Humanos , Síndrome do Intestino Irritável/complicações , Morbidade , Qualidade de Vida , Estudos Retrospectivos
2.
Med J Malaysia ; 76(6): 811-813, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34806665

RESUMO

BACKGROUND: Coeliac disease, an autoimmune enteropathy related to gluten sensitivity was hitherto thought to be rare in Asia. Recent data however suggests that Celiac disease may be under-diagnosed in Asia. OBJECTIVE: The aim of this audit was to determine the frequency of histological changes compatible with Coeliac disease among patients undergoing elective diagnostic oesaphago-gastro-duodenoscopy (OGDS) under the care of a single practitioner in a Malaysian hospital. MATERIALS AND METHODS: The archived endoscopically obtained duodenal biopsy specimens of 241 consecutive Malaysian subjects undergoing elective diagnostic (OGDS) were reviewed by a pathologist blinded to the clinical data. Based on intra-epithelial lymphocyte counts, crypt hyperplasia and villous atrophy, each subject was assigned to one of the categories of the Modified Marsh classification for the histological diagnosis of Coeliac disease. The clinical charts of all subjects were reviewed by a single gastroenterologist blinded to the findings of the histological review. RESULTS: Of the 241 study subjects, 132 (54.8%) were females. There were 56 (23.2%) Malays, 90 (37.3%) Chinese, 88 (36.5%) Indians and seven (2.9%) from the other category. The median age of the study sample was 49 years (range 15- 88 years). The OGDS was done as part of screening in 15(6.2%) subjects while in the remaining it was part of the investigation of a clinical problem. Based on histological findings, none of the subjects could be assigned to a modified Marsh class of >1. The prevalence of histological changes compatible with Coeliac disease in the study was 0% (binomial exact one-sided 97.5 % confidence interval 0- 1.52%). CONCLUSION: In conclusion, this audit provides no evidence that active Coeliac disease is significantly under-detected among symptomatic patients presenting for diagnostic OGDS. The possibility that a significant number may have potential coeliac disease cannot be excluded.


Assuntos
Doença Celíaca , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Doença Celíaca/diagnóstico , Doença Celíaca/patologia , Duodeno/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
3.
J Fluoresc ; 27(5): 1897-1908, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28667371

RESUMO

The authors report Ho3+ ion incorporated and fluorescent dye-doped silica nanoparticles which are engineered to enable the imaging modalities of receptor targeted fluorescence imaging (FI) and magnetic resonance imaging (MRI). The silica nanoparticles synthesized through a modified Stöber method is luminomagnetic by virtue of the luminescence of organic dye fluorophore (FITC) and magnetism of Ho3+. The doping concentration of Ho3+ is estimated by inductively coupled plasma mass spectrometry (ICP-MS) as 0.97%. The presence of Ho3+ has a little effect on the luminescence intensity but impart strong paramagnetism of 27.217 emu/g at room temperature. The relaxivity measurements shown that the nanoparticles exhibit a longitudinal relaxivity (r1) of 0.12 s-1 mM-1 and transverse relaxivity (r2) of 26.96 s-1 mM-1, which makes the system potentially suitable for developing T2 MRI contrast agents based on holmium. The luminomagnetic nanoparticles were surface engineered through aminization and conjugated with folic acid (FA) to address the folate receptor targeted imaging of the cancer cells. The biocompatibility studies revealed no apparent toxicity even at higher doses of 750 µg/mL and at 48 h of incubation. The as prepared nanoparticles were demonstrated as a bioimaging probe in the in vitro receptor targeted fluorescence imaging of HeLa cells. The luminescence and magnetism together with biocompatibility enables the adaptability of the present system as a nano platform for potential bimodal imaging. Graphical Abstract ᅟ.


Assuntos
Corantes Fluorescentes/química , Receptores de Folato com Âncoras de GPI/metabolismo , Hólmio/química , Imageamento por Ressonância Magnética/métodos , Nanopartículas Metálicas/química , Imagem Molecular/métodos , Dióxido de Silício/química , Fluorescência , Ácido Fólico/metabolismo , Células HeLa , Humanos , Células MCF-7 , Microscopia de Fluorescência/métodos
4.
Med J Malaysia ; 71(2): 88-90, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-27326953

RESUMO

Chronic diarrhoea in tropical countries may be due to a myriad of causes from infective to non-infective. This case report illustrates the challenges faced in the investigation of a middle-age Chinese gentleman who presented with chronic diarrhoea and weight loss. The diagnosis of type II enteropathy-associated T-cell lymphoma (EATL) was finally made. The diagnosis of EATL was least suspected as the condition is almost unheard of in this part of the world. The epidemiology, presentation, diagnosis, management and prognosis of this rare condition are discussed.


Assuntos
Diarreia/etiologia , Linfoma de Células T Associado a Enteropatia/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
5.
Rev Sci Instrum ; 87(3): 036108, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27036841

RESUMO

A dynamic experiment at mesoscale is developed to measure local deformation and strain in granular materials at high temporal and spatial resolutions. The experimental setup is comprised of a high-speed camera along with a high magnification extension tube. The method is demonstrated by measuring the full field strain across and in the boundary of the crystals at a high temporal resolution in polymer bonded sugar crystals and glass beads filled epoxy particulate composite specimens under dynamic loading. In both cases, the local strain heterogeneity is captured successfully. The measured strain and deformation field can be further used to obtain the relative motion of each crystal, crystal rotation, and the relative displacement between the polymer interface and the crystal, which are very critical to understand the local failure mechanisms in heterogeneous materials.

6.
J Dent Res ; 94(4): 608-14, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25694469

RESUMO

Remineralization of dentin during dental caries is of considerable clinical interest. Dentin matrix protein 1 (DMP1) is a non-collagenous calcium-binding protein that plays a critical role in biomineralization. In the present study, we tested if peptides derived from DMP1 can be used for dentin remineralization. Peptide pA (pA, MW = 1.726 kDa) and peptide pB (pB, MW = 2.185), containing common collagen-binding domains and unique calcium-binding domains, were synthesized by solid-phase chemistry. An extreme caries lesion scenario was created by collagenase digestion, and the biomineral-nucleating potential of these peptides was ascertained when coated on collagenase-treated dentin matrix and control, native human dentin matrix under physiological levels of calcium and phosphate. Scanning electron microscopy analysis suggests that peptide pB was an effective nucleator when compared with pA. However, a 1:4 ratio of pA to pB was determined to be ideal for dentin remineralization, based on hydroxyapatite (HA) morphology and calcium/phosphorus ratios. Interestingly, HA was nucleated on collagenase-challenged dentin with as little as 20 min of 1:4 peptide incubation. Electron diffraction confirmed the presence of large HA crystals that produced a diffraction pattern indicative of a rod-like crystal structure. These findings suggest that DMP1-derived peptides may be useful to modulate mineral deposition and subsequent formation of HA when exposed to physiological concentrations of calcium and phosphate.


Assuntos
Dentina/efeitos dos fármacos , Proteínas da Matriz Extracelular/farmacologia , Fosfoproteínas/farmacologia , Remineralização Dentária , Materiais Biomiméticos/farmacologia , Cálcio/farmacologia , Proteínas de Ligação ao Cálcio/farmacologia , Colágeno Tipo I/metabolismo , Cristalografia , Cárie Dentária/metabolismo , Cárie Dentária/patologia , Dentina/metabolismo , Dentina/ultraestrutura , Durapatita/metabolismo , Humanos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Fragmentos de Peptídeos/farmacologia , Fosfatos/farmacologia , Ligação Proteica , Sialoglicoproteínas/farmacologia , Fatores de Tempo , Difração de Raios X
7.
J Dent Res ; 93(2): 155-61, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24352500

RESUMO

The major phosphoprotein in dentin is the aspartic acid and serine-rich protein called dentin phosphophoryn (DPP). DPP appears to be synthesized as a part of a larger compound protein, dentin sialophosphoprotein (DSPP). DSPP has never been isolated or detected in dentin extracts. It is now evident that DSPP is a chimeric protein composed of 3 parts: dentin sialoprotein (DSP), DPP, and dentin glycoprotein (DGP). Previous reports have suggested that the BMP1 protease is responsible for processing DSPP. However, unequal amounts of these products are present in the dentin matrix. Here, we provide evidence for an internal ribosome entry site in the DSPP gene that directs the synthesis of DPP. This mechanism would account for unequal amounts of intracellular DSP and DPP. The internal ribosomal entry site (IRES) activity varied in different cell types, suggesting the presence of additional regulatory elements during the translational regulation of DPP. Further, we provide evidence that DPP is transported to the extracellular matrix (ECM) through exosomes. Using tissue recombination and lentivirus-mediated gain-of-function approaches, we also demonstrate that DPP is essential for the formation of well-defined tooth structures with mineralized dentin matrix.


Assuntos
Proteínas da Matriz Extracelular/genética , Fosfoproteínas/genética , Biossíntese de Proteínas/genética , Ribossomos/genética , Sialoglicoproteínas/genética , Células 3T3 , Animais , Linhagem Celular , Polpa Dentária/citologia , Dentina/ultraestrutura , Dentinogênese/genética , Exossomos/metabolismo , Matriz Extracelular/ultraestrutura , Proteínas da Matriz Extracelular/metabolismo , Vetores Genéticos/genética , Células HEK293 , Humanos , Lentivirus/genética , Masculino , Camundongos , Camundongos Knockout , Fosfoproteínas/metabolismo , Plasmídeos/genética , Modificação Traducional de Proteínas/genética , Elementos Reguladores de Transcrição/genética , Sialoglicoproteínas/metabolismo , Vírus 40 dos Símios/genética , Células-Tronco/citologia
8.
Hum Immunol ; 74(1): 1-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23000501

RESUMO

CD40, an antigen-presenting cell expressed costimulatory receptor molecule, binds to T cell expressed CD40-ligand (CD40-L). Using a mouse tumor model, we showed previously that lower CD40/CD40-L expression levels promoted tumor growth whereas higher CD40/CD40-L expression levels led to tumor regression indicating duality in CD40 functions. Whether CD40/CD40-L expressions are regulated in cancer patients is unknown. Herein, we show that the CD40 and CD40-L expressions on monocytes and T cells, respectively, decrease as the head and neck squamous cell carcinoma (HNSCC) patients progress from stage-I through stage-IV suggesting a novel CD40/CD40-L expression based staging of HNSCC tumor. The staging is confirmed by TNM and histo-pathological staging. The levels of soluble CD40 (sCD40) and sCD40-L are also modulated in patients' plasma. As CD40 expressing monocytes increase in the post-operative patients, CD40 expression levels are possibly regulated by tumor load. This change is accompanied by increased IL-12 expressing monocytes and decreased IL-10 expression levels. Thus, our findings on CD40/CD40-L expression in HNSCC patients bear significant implications.


Assuntos
Antígenos CD40/genética , Ligante de CD40/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Monócitos/metabolismo , Linfócitos T/metabolismo , Adulto , Idoso , Antígenos CD40/sangue , Ligante de CD40/sangue , Carcinoma de Células Escamosas/sangue , Carcinoma de Células Escamosas/diagnóstico , Estudos de Casos e Controles , Feminino , Citometria de Fluxo , Neoplasias de Cabeça e Pescoço/sangue , Neoplasias de Cabeça e Pescoço/diagnóstico , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Monócitos/patologia , Estadiamento de Neoplasias , Transdução de Sinais , Solubilidade , Carcinoma de Células Escamosas de Cabeça e Pescoço , Linfócitos T/patologia
10.
Clin Exp Immunol ; 134(3): 477-81, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14632754

RESUMO

To study the safety and efficacy of thymosin alpha1 in stimulating immune reconstitution in combination with highly active antiretroviral therapy (HAART), a phase II randomized, controlled open-label trial of subcutaneous thymosin alpha1 was undertaken for 12 weeks. Twenty clinically stable patients with viral loads <400 copies/ml and CD4 counts less than 200 cells/microl were randomized to receive 3.2 mg thymosin alpha 1 subcutaneous injections twice weekly or no injections for 12 weeks. CD4 and CD8 counts, CD45 RO+ and RA+ subsets and signal joint T cell receptor excision circles (sjTREC) in peripheral blood mononuclear cells (PBMCs) were measured every 2 weeks. Thirteen patients received thymosin alpha 1 and seven were controls. Thymosin alpha 1 was well tolerated and there were no serious adverse events. There was no significant difference between the thymosin alpha1 and control groups in CD4, CD8 and CD45 lymphocyte subset changes at week 12; however, PBMC sjTREC levels increased significantly in the thymosin alpha 1-treated patients compared to controls at week 12. In conclusion, the increase in PBMC sjTREC levels in patients taking thymosin alpha1 may represent enhanced immune reconstitution; however, the clinical benefits and long-term consequences remain to be determined.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , HIV-1 , Timosina/análogos & derivados , Timosina/uso terapêutico , Adulto , Análise de Variância , Terapia Antirretroviral de Alta Atividade , Contagem de Linfócito CD4 , Humanos , Subpopulações de Linfócitos , Linfopoese , Pessoa de Meia-Idade , Projetos Piloto , Timalfasina , Carga Viral
11.
Blood Coagul Fibrinolysis ; 13(8): 711-4, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12441910

RESUMO

C1-inhibitor is an important inhibitor of plasma kallikrein and C1, but also has inhibitory activity against numerous other plasma proteinases such as plasmin. The relevance of plasmin inhibition by the C1-inhibitor has been debated, with some evidence showing that plasmin causes significant proteolysis of C1-inhibitor. In the present study, we show that C1-inhibitor in its native state will inhibit plasmin without being significantly degraded, in a manner typical of all serpin reactions. However, if C1-inhibitor is in a denatured polymeric state (as can easily occur during storage, or as produced by heating of the native protein), it will be extensively degraded by plasmin. In addition, we show that hydrophobic interaction chromatography is an effective method to remove trace contaminants of inactive C1-inhibitor polymers.


Assuntos
Preservação de Sangue/métodos , Proteínas Inativadoras do Complemento 1/metabolismo , Fibrinolisina/antagonistas & inibidores , Cromatografia , Proteínas Inativadoras do Complemento 1/isolamento & purificação , Proteína Inibidora do Complemento C1 , Inibidores de Cisteína Proteinase/isolamento & purificação , Inibidores de Cisteína Proteinase/metabolismo , Dimerização , Fibrinolisina/metabolismo , Humanos , Desnaturação Proteica , Inibidores de Serina Proteinase , Serpinas
12.
Arch Biochem Biophys ; 386(2): 123-35, 2001 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11368334

RESUMO

The pyruvate dehydrogenase (E1) component of the pyruvate dehydrogenase complex (PDC) catalyzes a two-step reaction. Recombinant production of substrate amounts of the lipoyl domains of the dihydrolipoyl transacetylase (E2) component of the mammalian PDC allowed kinetic characterization of the rapid physiological reaction catalyzed by E1. Using either the N-terminal (L1) or the internal (L2) lipoyl domain of E2 as a substrate, analyses of steady state kinetic data support a ping pong mechanism. Using standard E1 preparations, Michaelis constants (Km) were 52 +/- 14 microM for L1 and 24.8 +/- 3.8 microM for pyruvate and k(cat) was 26.3 s(-1). With less common, higher activity preparations of E1, the Km values were > or =160 microM for L1 and > or =35 microM for pyruvate and k(cat) was > or =70 s(-1). Similar results were found with the L2 domain. The best synthetic lipoylated-peptide (L2 residues 163-177) was a much poorer substrate (Km > or =15 mM, k(cat) approximately equals 5 s(-1); k(cat)/Km decreased >1,500-fold) than L1 or L2, but a far better substrate in the E1 reaction than free lipoamide (k(cat)/Km increased >500-fold). Each lipoate source was an effective substrate in the dihydrolipoyl dehydrogenase (E3) reaction, but E3 had a lower Km for the L2 domain than for lipoamide or the lipoylated peptides. In contrast to measurements with slow E1 model reactions that use artificial acceptors, we confirmed that the natural E1 reaction, using lipoyl domain acceptors, was completely inhibited (>99%) by phosphorylation of E1 and the phosphorylation strongly inhibited the reverse of the second step catalyzed by E1. The mechanisms by which phosphorylation interferes with E1 activity is interpreted based on accrued results and the location of phosphorylation sites mapped onto the 3-D structure of related alpha-keto acid dehydrogenases.


Assuntos
Acetiltransferases/química , Acetiltransferases/metabolismo , Complexo Piruvato Desidrogenase/química , Complexo Piruvato Desidrogenase/metabolismo , Ácido Tióctico/análogos & derivados , Acetilação , Animais , Bovinos , Dicroísmo Circular , Di-Hidrolipoamida Desidrogenase/metabolismo , Di-Hidrolipoil-Lisina-Resíduo Acetiltransferase , Humanos , Cinética , Modelos Moleculares , Fosforilação , Ligação Proteica , Estrutura Terciária de Proteína , Ácido Pirúvico/metabolismo , Termodinâmica , Tiamina Pirofosfato/metabolismo , Ácido Tióctico/metabolismo
13.
Ann Surg Oncol ; 4(5): 421-4, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9259970

RESUMO

BACKGROUND: Complete resection of a retroperitoneal sarcoma often requires removal of adjacent organs. In this study we evaluated the role of nephrectomy during operation for retroperitoneal sarcoma. METHODS: Between July 1982 and July 1995, 75 of the 371 (20%) patients who underwent resection of retroperitoneal sarcoma at MSKCC underwent concommitant nephrectomy. Data concerning the reasons for nephrectomy, degree of sarcomatous renal involvement, and survival were retrospectively analyzed. RESULTS: Fifty-four patients (72%) underwent nephrectomy during the initial resection, and 21 (28%) during a resection of a recurrent or persistent tumor. The most common reason for nephrectomy was total encasement by sarcoma (n = 40; 53%), followed by dense adherence of the tumor to the kidney (n = 21; 28%), and the direct invasion of the kidney by tumor (n = 2; 3%). Pathology demonstrated an absence of kidney invasion in the majority of cases (55 of 75; 73%). Renal capsular invasion was present in 11 of 75 (15%), renal parenchymal invasion in 7 of 75 (9%), and renal vein invasion in 2 of 75 (3%) of cases. There were no significant differences in survival based on degree of sarcoma involvement of the kidney, tumor grade, or whether the resection was for primary or recurrent disease. The 53 patients who underwent a complete gross resection of all tumor had a significantly improved long-term survival compared to the 20 patients who did not (50% versus 20% DFS at 5 years, respectively; p < 0.001). CONCLUSIONS: Decisions for concomitant nephrectomy during resection of retroperitoneal sarcoma should be based on whether this maneuver will provide a complete resection of all gross tumor, in which case the long-term disease-free survival of 50% is comparable to the reported 5-year survival of all patients with retroperitoneal sarcoma who are completely resected.


Assuntos
Nefrectomia , Neoplasias Retroperitoneais/cirurgia , Sarcoma/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Humanos , Rim/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias Retroperitoneais/mortalidade , Neoplasias Retroperitoneais/patologia , Sarcoma/mortalidade , Sarcoma/patologia , Taxa de Sobrevida
14.
J Biol Chem ; 271(2): 653-62, 1996 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-8557670

RESUMO

To conserve carbohydrate reserves, the reaction of the pyruvate dehydrogenase complex (PDC) must be down-regulated when the citric acid cycle is provided sufficient acetyl-CoA. PDC activity is reduced primarily through increased phosphorylation of its pyruvate dehydrogenase (E1) component due to E1 kinase activity being markedly enhanced by elevated intramitochondrial NADH:NAD+ and acetyl-CoA:CoA ratios. A mechanism is evaluated in which enhanced kinase activity is facilitated by the build-up of the reduced and acetylated forms of the lipoyl moieties of the dihydrolipoyl acetyltransferase (E2) component through using NADH and acetyl-CoA in the reverse of the downstream reactions of the complex. Using a peptide substrate, kinase activity was stimulated by these products, ruling out the possibility kinase activity is increased due to changes in the reaction state of its substrate, E1 (thiamin pyrophosphate). Each E2 subunit contains two lipoyl domains, an NH2-terminal (L1) and the inward lipoyl domain (L2), which were individually produced in fully lipoylated forms by recombinant techniques. Although reduction and acetylation of the L1 domain or free lipoamide increased kinase activity, those modifications of the lipoate of the kinase-binding L2 domain gave much greater enhancements of kinase activity. The large stimulation of the kinase generated by acetyl-CoA only occurred upon addition of the transacetylase-catalyzing (lipoyl domain-free) inner core portion of E2 plus a reduced lipoate source, affirming that acetylation of this prosthetic group is an essential mechanistic step for acetyl-CoA enhancing kinase activity. Similarly, the lesser stimulation of kinase activity by just NADH required a lipoate source, supporting the need for lipoate reduction by E3 catalysis. Complete enzymatic delipoylation of PDC, the E2-kinase subcomplex, or recombinant L2 abolished the stimulatory effects of NADH and acetyl-CoA. Retention of a small portion of PDC lipoates lowered kinase activity but allowed stimulation of this residual kinase activity by these products. Reintroduction of lipoyl moieties, using lipoyl protein ligase, restored the capacity of the E2 core to support high kinase activity along with stimulation of that activity up to 3-fold by NADH and acetyl-CoA. As suggested by those results, the enhancement of kinase activity is very responsive to reductive acetylation with a half-maximal stimulation achieved with approximately 20% of free L2 acetylated and, from an analysis of previous results, with acetylation of only 3-6 of the 60 L2 domains in intact PDC. Based on these findings, we suggest that kinase stimulation results from modification of the lipoate of an L2 domain that becomes specifically engaged in binding the kinase. In conclusion, kinase activity is attenuated through a substantial range in response to modest changes in the proportion of oxidized, reduced, and acetylated lipoyl moieties of the L2 domain of E2 produced by fluctuations in the NADH:NAD+ and acetyl-CoA:CoA ratios as translated by the rapid and reversible E3 and E2 reactions.


Assuntos
Proteínas Quinases/metabolismo , Complexo Piruvato Desidrogenase/metabolismo , Acetilcoenzima A/metabolismo , Amidoidrolases/metabolismo , Ativação Enzimática , Indução Enzimática , Escherichia coli/enzimologia , Escherichia coli/genética , Retroalimentação , NAD/metabolismo , Proteínas Serina-Treonina Quinases , Piruvato Desidrogenase Quinase de Transferência de Acetil , Especificidade por Substrato
15.
Age Ageing ; 22(2): 103-8, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8470555

RESUMO

A group of 420 elderly people (163 women and 257 men with a mean age of 65 years) from urban and rural populations in India were selected for the study. The caloric intake of 93.3% was less than the recommended allowance, the mean daily caloric intake being 1191 kcal in men and 928 kcal in women. Except for calcium, all nutrients were deficient in their diet. Illiteracy (53%), lack of knowledge regarding daily allowances of nutrients (95%), poor economic background (46.7%), and breaking down of joint family system (63%) were possible associated factors examined.


Assuntos
Países em Desenvolvimento , Avaliação Geriátrica , Avaliação Nutricional , População Rural , População Urbana , Idoso , Idoso de 80 Anos ou mais , Feminino , Preferências Alimentares , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Necessidades Nutricionais , Meio Social , Fatores Socioeconômicos
16.
Biochem Biophys Res Commun ; 190(3): 982-91, 1993 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-8439347

RESUMO

Mammalian pyruvate dehydrogenase kinase binds to the lipoyl domain region of the core structure forming dihydrolipoyl acetyltransferase (E2) subunits. The bound kinase has a greatly enhanced rate in phosphorylating E2-bound pyruvate dehydrogenase (E1) tetramers versus the rate at which resolved kinase phosphorylates dissociated E1. This E2-activated kinase function was completely prevented by selective alkylation of reduced lipoyl groups while kinase and E1 binding to the E2 core were retained. Selective removal of lipoyl cofactors from intact E2 by treatment with Enterococcus faecalis lipoamidase decreased kinase activity by 4-fold and caused selective release of a major portion of the kinase from E2 in a sucrose-step gradient procedure. Selective and reversible modification of the lipoyl groups of E2 subunits also allowed the kinase to be dissociated under mildly chaotropic conditions. Thus, the lipoyl prosthetic group on one of the two lipoyl domains of E2 subunits is critically important for maintaining E2-activated kinase function and contributes to binding of the kinase to E2. Since removal of the lipoyl group weakened kinase binding to E2 more than modifying lipoyl thiols, it is suggested that the hydrophobic inner portion of the lipoyl conjugate (i.e., lysine carbons and C1 to C5 of the lipoic acid) is important in the binding of the kinase.


Assuntos
Acetiltransferases/metabolismo , Proteínas Quinases/metabolismo , Complexo Piruvato Desidrogenase/metabolismo , Acetilação , Alquilação , Amidoidrolases/farmacologia , Animais , Bovinos , Di-Hidrolipoil-Lisina-Resíduo Acetiltransferase , Técnicas In Vitro , Proteínas Serina-Treonina Quinases , Piruvato Desidrogenase Quinase de Transferência de Acetil , Relação Estrutura-Atividade
17.
Community Dev J ; 20(3): 213-21, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-12315293

RESUMO

PIP: This article describes the effort of a group of rural women belonging to the untouchable "Paraiya" caste in South India to initiate and build an organization of their own to stand up for their rights and to challenge their oppression. The description covers the evolution from literacy to health action; the orientation workshop (which included building confidence through sharing experiences, participatory training techniques, reflecting on women's position in society, creating new attitudes of self value, identifying oppressive attitudes and structures in society, and the socioeconomic and political causes of disease); and the role of animators. Rural Women's Social Education Center (RUWSEC) in Chingleput, South India, was initiated in 1981 by 10 women who belonged to the villages of Chingleput and the author. The women had come together because of involvement in a nationwide literacy campaign in which the 10 village women worked as literacy teachers in their respective villages. Through their work, the women realized their own worth and potential and felt committed to working with other women in their communities to change their exploited situation. RUWSEC has focused on activities and issues related to women and health. 10 women "animators" began working in their villages carrying out health care, health education, and working towards building a women's organization in those villages. The animators' approach was to help women understand their own and/or communities' health problems and participate in their own healing. As a result of the efforts of RUWSEC, there were requests from several villages in the neighborhood for the creation of women's centers, and the animators decided to extend their work to 5 more villages. They visited the 5 villages and asked the community to nominate their own animators. The animators chosen were introduced to the work and philosophy of RUWSEC through a 6-day orientation program organized by the senior animators. The animators of RUWSEC, after 2 years of training in administration, accounting and management, and in conducting training programs, now are in charge of all their own activities. They have ventured also to further build and expand their organization.^ieng


Assuntos
Atitude , Comportamento , Atenção à Saúde , Economia , Educação , Identidade de Gênero , Serviços de Saúde , Organizações , Características da População , População , População Rural , Comportamento Social , Mudança Social , Classe Social , Planejamento Social , Fatores Socioeconômicos , Direitos da Mulher , Ásia , Biologia , Proteção da Criança , Demografia , Países em Desenvolvimento , Saúde , Índia , Bem-Estar Materno , Política , Psicologia
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