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1.
J Interv Card Electrophysiol ; 67(2): 303-317, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37354370

RESUMO

BACKGROUND: Real-time phase mapping (ExTRa™) is useful in determining the strategy of catheter ablation for non-paroxysmal atrial fibrillation (AF). This study aimed to investigate the features of drivers of AF associated with its termination during ablation. METHODS: Thirty-six patients who underwent catheter ablation for non-paroxysmal AF using online real-time phase mapping (ExTRa™) were enrolled. A significant AF driver was defined as an area with a non-passively activated ratio of ≥ 50% on mapping analysis in the left atrium (LA). All drivers were simultaneously evaluated using a low-voltage area, complex fractionated atrial electrogram (CFAE), and rotational activity by unipolar electrogram analysis. The electrical characteristics of drivers were compared between patients with and without AF termination during the procedure. RESULTS: Twelve patients achieved AF termination during the procedure. The total number of drivers detected on the mapping was significantly lower (4.4 ± 1.6 vs. 7.4 ± 3.8, p = 0.007), and the drivers were more concentrated in limited LA regions (2.8 ± 0.9 vs. 3.9 ± 1.4, p = 0.009) in the termination group than in the non-termination group. The presence of drivers 2-6 with limited (≤ 3) LA regions showed a tenfold increase in the likelihood of AF termination, with 83% specificity and 67% sensitivity. Among 231 AF drivers, the drivers related to termination exhibited a greater overlap of CFAE (56.8 ± 34.1% vs. 39.5 ± 30.4%, p = 0.004) than the non-related drivers. The termination group showed a trend toward a lower recurrence rate after ablation (p = 0.163). CONCLUSIONS: Rotors responsible for AF maintenance may be characterized in cases with concentrated regions and fewer drivers on mapping.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Humanos , Fibrilação Atrial/cirurgia , Átrios do Coração/cirurgia , Ablação por Cateter/métodos , Técnicas Eletrofisiológicas Cardíacas/métodos , Resultado do Tratamento
2.
Gan To Kagaku Ryoho ; 50(13): 1569-1571, 2023 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-38303344

RESUMO

A 72-year-old woman presented with obstructive jaundice. Computed tomography revealed a 12-mm low-density mass in the head of the pancreas. She was diagnosed as having pancreatic cancer by endoscopic ultrasound-guided fine-needle aspiration. She received gemcitabine plus nab-paclitaxel as preoperative chemotherapy. After 2 courses, hepatoduodenal lymph node metastasis appeared and was accompanied by increased tumor marker levels. The regimen was changed to modified FOLFIRINOX. After 5 courses, the lymph node metastasis was reduced in size and the tumor marker levels were decreased, so subtotal stomach-preserving pancreaticoduodenectomy was performed. Adjuvant chemotherapy was administered postoperatively. The patient was alive and well without recurrence 2 years and 9 months after the surgery, but died of sepsis. Nevertheless, this case highlights that when preoperative chemotherapy for resectable pancreatic cancer appears to be ineffective, a change in regimen may be useful.


Assuntos
Neoplasias Pancreáticas , Feminino , Humanos , Idoso , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/cirurgia , Neoplasias Pancreáticas/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Terapia Neoadjuvante , Metástase Linfática , Biomarcadores Tumorais , Irinotecano , Oxaliplatina , Leucovorina , Fluoruracila
3.
Front Pharmacol ; 12: 766402, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34867392

RESUMO

Amid the global outbreak of coronavirus disease 2019 (COVID-19), it may be expected that low-toxicity natural compounds, such as Kampo formulas, will have a preventive effect on COVID-19. Although the biological properties and safety of the representative Kampo compounds, hochuekkito (HET) and kakkonto (KKT), have been confirmed in various animal model experiments, clinical studies, and a few human studies to induce biological effects on various infectious diseases without significant toxicity, it is unclear whether HET and KKT are safe and effective for COVID-19 prevention. The study population included healthcare workers (HCWs), as they are at a higher risk of infection than the other populations. We retrospectively investigated the immunological and preventive effects of HET and KTT against COVID-19. We included 27 HCWs (aged 21-72 years, F:M = 18:9) from hospitals and clinics of the Hokuriku-Tokai region. The HCWs received HET and KKT for general fatigue and myalgia during this period for 28 days. We obtained patient clinical data from electronic medical records. We analyzed the changes in immunomodulation before and after the administration of the formulas from residual specimens based on the expression of relevant surface markers. The specimens were also tested for the presence of antibodies against severe acute respiratory syndrome coronavirus 2. The following side effects were reported: abdominal discomfort in five patients, diarrhea in two, and loose or soft stool in three. All 27 HCWs tested negative for COVID-19 antibodies. HET and KKT administration significantly increased the absolute number of circulating lymphocytes expressing the activating receptors NKp46, NKp30, and suppressing receptor NKG2A. There was also a significant increase in the absolute number of circulating lymphocytes expressing the receptors TLR4, OX40, 4-1BB, GITR, PD-1, and ICOS. These data indicate that HET and KKT can enhance and modulate NK activity in circulating human immune cells. The immunomodulatory effects, such as activation and regulation of T cells, are consistent with a putative improvement in infectious immunosurveillance. An increase in the number of T cells and CD4/CD8-positive cells indicates an enhanced ability to protect against infection. HET and KKT may prevent the onset or worsening of COVID-19 through their immunomodulatory effects.

4.
Nutrients ; 11(6)2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31234376

RESUMO

Gnetin-C is a naturally occurring stilbene derived from the seeds of Gnetum gnemon L., an edible plant native to Southeast Asia that is called melinjo. Although the biological properties and safety of G. gnemon extract, which contains nearly 3% Gnetin-C, have been confirmed in various human studies, whether or not pure Gnetin-C is safe for humans is unclear at present. We conducted a randomized, double-blind, placebo-controlled trial. Healthy subjects were randomly divided into two groups. The interventional group (n = 6) was given Gnetin-C, and the control group (n = 6) was provided a placebo, for 14 days. Lipid profiles, biomarkers of oxidative stress and circulating blood cells were assessed before and after the intervention. All subjects completed the study, with no side effects reported across the study duration. Gnetin-C supplementation demonstrated a statistically significant increase in the absolute number of circulating natural killer (NK) cells expressing the activating receptors NKG2D and NKp46. NK cells derived from subjects who received Gnetin-C for two weeks showed higher cytotoxicity against K562 target cells than those before receiving Gnetin-C. In addition, Gnetin-C also resulted in a significant decrease in the absolute neutrophil count in the blood compared with the placebo. Furthermore, Gnetin-C significantly reduced the levels of uric acid, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total adiponectin, and high-molecular-weight adiponectin. These data indicate that Gnetin-C has biological effects of enhancing the NK activity on circulating human immune cells. The immunomodulatory effects are consistent with a putative improvement in cancer immunosurveillance via the upregulation of the NKG2D receptor. The study was registered with UMIN-CTR, number 000030364, on 12 December 2017.


Assuntos
Benzofuranos/administração & dosagem , Suplementos Nutricionais , Metabolismo Energético/efeitos dos fármacos , Fatores Imunológicos/administração & dosagem , Células Matadoras Naturais/efeitos dos fármacos , Estilbenos/administração & dosagem , Adulto , Benzofuranos/efeitos adversos , Benzofuranos/farmacocinética , Biomarcadores/sangue , Técnicas de Cocultura , Citotoxicidade Imunológica/efeitos dos fármacos , Suplementos Nutricionais/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Fatores Imunológicos/efeitos adversos , Fatores Imunológicos/farmacocinética , Japão , Células K562 , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Subfamília K de Receptores Semelhantes a Lectina de Células NK/sangue , Receptor 1 Desencadeador da Citotoxicidade Natural/sangue , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Estresse Oxidativo/efeitos dos fármacos , Estilbenos/efeitos adversos , Estilbenos/farmacocinética , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
5.
Atherosclerosis ; 249: 65-9, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27065243

RESUMO

BACKGROUND AND AIMS: Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) are widely recognized to have beneficial effects against cardiovascular disease. We investigated the association of n-3 PUFAs levels with carotid atherosclerosis in patients on hemodialysis (HD), who are at high risk for cardiovascular events. METHODS: Carotid ultra-sound was performed in a total of 461 patients on HD (male 67%, age 67 ± 12years, diabetes rate 46%). Intima-media thickness (IMT) and the plaque score (PS) in carotid arteries were measured. Carotid atherosclerosis was defined as IMT >1.2 mm and/or PS > 5.0. The levels of n-6 PUFAs [dihomo-gamma-linolenic acid (DHLA) and arachidonic acid (AA)] and n-3 PUFAs [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] were also measured prior to carotid ultra-sound. RESULTS: Carotid atherosclerosis was observed in 94 patients (20.4%). Individual PUFAs levels were comparable between patients with and without carotid atherosclerosis. However, the ratio of EPA/AA and that of n-3/n-6 PUFAs were significantly lower in patients with carotid atherosclerosis compared to those without (median 0.36 vs. 0.41, p = 0.031 and 0.85 vs. 0.93, p = 0.041, respectively]. After adjustment for other confounders, the ratio of EPA/AA (OR 0.30, 95% CI 0.12-0.70, p = 0.0055) and the ratio of n-3/n-6 PUFAs (OR 0.45, 95% CI 0.25-0.80, p = 0.0066) showed an independent reverse association with carotid atherosclerosis. In addition, the area under receiver-operating characteristic curves for carotid atherosclerosis was significantly greater in an established risk model with EPA/AA and n-3/n-6 ratios than in the established risk model alone. CONCLUSIONS: These data suggest that low ratios of both EPA/AA ratio and n-3/n-6 PUFAs were closely associated with carotid atherosclerosis in patients on HD.


Assuntos
Doenças das Artérias Carótidas/sangue , Ácidos Graxos Ômega-3/sangue , Ácidos Graxos Ômega-6/sangue , Diálise Renal , Idoso , Doenças Cardiovasculares/sangue , Artérias Carótidas/diagnóstico por imagem , Espessura Intima-Media Carotídea , Ácidos Docosa-Hexaenoicos/sangue , Ácido Eicosapentaenoico/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Fatores de Risco
6.
Gan To Kagaku Ryoho ; 42(12): 2184-6, 2015 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-26805305

RESUMO

A 58-year-old woman was diagnosed with a sigmoid colon cancer and synchronous liver metastasis. Because an obstruction of the sigmoid colon was identified, the patient underwent sigmoidectomy. Computed tomography(CT)findings suggested possible vena cava and hepatic vein invasion. Therefore, the decision was made to offer systemic chemotherapy. The patient underwent 6 courses of chemotherapy with 5-fluorouracil, Leucovorin, and oxaliplatin (mFOLFOX6). After 4 courses of chemotherapy, CT scans showed a significant reduction of the liver metastasis (reduction rate of 5 0%; a partial response) and demonstrated improved exclusion of the inferior vena cava and hepatic vein. After 6 courses of chemotherapy, we performed right trisegmentectomy of the liver and resection of the inferior vena cava and diaphragm. Postoperative pathological findings revealed negative margins, and no invasion of the inferior vena cava. The pathological response grade of the tumor after chemotherapy was determined to be Grade 2. Adjuvant chemotherapy was not performed because of the patient 's poor performance status. The patient was alive with no recurrence 8 years after resection of the liver metastasis.


Assuntos
Neoplasias Hepáticas/secundário , Neoplasias do Colo Sigmoide/patologia , Veia Cava Inferior/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Terapia Combinada , Feminino , Fluoruracila/uso terapêutico , Humanos , Leucovorina/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/cirurgia , Pessoa de Meia-Idade , Invasividade Neoplásica , Compostos Organoplatínicos/uso terapêutico , Neoplasias do Colo Sigmoide/tratamento farmacológico , Neoplasias do Colo Sigmoide/cirurgia , Fatores de Tempo , Veia Cava Inferior/cirurgia
7.
Am J Physiol Regul Integr Comp Physiol ; 293(4): R1474-89, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17626126

RESUMO

Roux-en-Y gastric bypass (RYGB) is the most effective therapy for morbid obesity, but it has a approximately 20% failure rate. To test our hypothesis that outcome depends on differential modifications of several energy-related systems, we used our established RYGB model in Sprague-Dawley diet-induced obese (DIO) rats to determine mechanisms contributing to successful (RGYB-S) or failed (RYGB-F) RYGB. DIO rats were randomized to RYGB, sham-operated Obese, and sham-operated obese pair-fed linked to RYGB (PF) groups. Body weight (BW), caloric intake (CI), and fecal output (FO) were recorded daily for 90 days, food efficiency (FE) was calculated, and morphological changes were determined. d-Xylose and fat absorption were studied. Glucose-stimulated vagal efferent nerve firing rates of stomach were recorded. Gut, adipose, and thyroid hormones were measured in plasma. Mitochondrial respiratory complexes in skeletal muscle and expression of energy-related hypothalamic and fat peptides, receptors, and enzymes were quantified. A 25% failure rate occurred. RYGB-S, RYGB-F, and PF rats showed rapid BW decrease vs. Obese rats, followed by sustained BW loss in RYGB-S rats. RYGB-F and PF rats gradually increased BW. BW loss in RYGB-S rats is achieved not only by RYGB-induced decreased CI and increased FO, but also via sympathetic nervous system activation, driven by increased peptide YY, CRF, and orexin signaling, decreasing FE and energy storage, demonstrated by reduced fat mass associated with the upregulation of mitochondrial uncoupling protein-2 in fat. These events override the compensatory response to the drop in leptin levels aimed at conserving energy.


Assuntos
Peso Corporal/fisiologia , Derivação Gástrica , Animais , Composição Corporal/fisiologia , Digestão/fisiologia , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Fezes , Comportamento Alimentar , Regulação da Expressão Gênica , Hipotálamo/metabolismo , Masculino , Músculo Esquelético , Ratos , Ratos Sprague-Dawley , Estômago/inervação , Fatores de Tempo , Nervo Vago/fisiologia , Xilose/metabolismo
8.
Endocrinology ; 148(6): 3004-12, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17347304

RESUMO

Cancer cachexia is a debilitating syndrome of anorexia and loss of lean body mass that accompanies many malignancies. Ghrelin is an orexigenic hormone with a short half-life that has been shown to improve food intake and weight gain in human and animal subjects with cancer cachexia. We used a rat model of cancer cachexia and administered human ghrelin and a synthetic ghrelin analog BIM-28131 via continuous infusion using sc osmotic minipumps. Tumor-implanted rats receiving human ghrelin or BIM-28131 exhibited a significant increase in food consumption and weight gain vs. saline-treated animals. We used dual-energy x-ray absorptiometry scans to show that the increased weight was due to maintenance of lean mass vs. a loss of lean mass in saline-treated animals. Also, BIM-28131 significantly limited the loss of fat mass normally observed in tumor-implanted rats. We further performed real-time PCR analysis of the hypothalami and brainstems and found that ghrelin-treated animals exhibited a significant increase in expression of orexigenic peptides agouti-related peptide and neuropeptide Y in the hypothalamus and a significant decrease in the expression of IL-1 receptor-I transcript in the hypothalamus and brainstem. We conclude that ghrelin and a synthetic ghrelin receptor agonist improve weight gain and lean body mass retention via effects involving orexigenic neuropeptides and antiinflammatory changes.


Assuntos
Composição Corporal/efeitos dos fármacos , Caquexia/etiologia , Caquexia/patologia , Ingestão de Alimentos/efeitos dos fármacos , Neoplasias/complicações , Hormônios Peptídicos/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Grelina , Hormônio do Crescimento/metabolismo , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Neoplasias/patologia , Ratos , Ratos Endogâmicos F344 , Carga Tumoral/efeitos dos fármacos
9.
Surgery ; 139(2): 202-8, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16455329

RESUMO

BACKGROUND: Tumor growth leads to cancer anorexia that is ameliorated using omega-3 fatty acids (omega-3FA). We hypothesize that omega-3FA modulates up-regulation of hypothalamic orexigenic neuropeptide Y (NPY) and down-regulation of anorexigenic alpha melanocyte-stimulating hormone (alpha-MSH) and serotonin 1B receptors (5-HT(1B)-receptors) in tumor-bearing rats. METHODS: Twenty-eight tumor-bearing rats were fed either chow (TB-Control) or omega-3FA (TB-omega-3FA). When anorexia developed in TB-Control rats, they and a cohort of TB-omega-pi-3 rats were killed. The rest had their tumor resected (R-Control and R-omega-3FA), and when anorexic TB-Controls normalized their food intake, brains were removed for hypothalamic immunocytochemical study of NPY, alpha-MSH, and 5-HT(1B)-receptor antibodies concentrations. Comparison among slides were assessed by image analysis and analyzed by ANOVA and t test. RESULTS: At anorexia, hypothalamic NPY in arcuate nucleus (ARC) increased by 38% in TB-omega3FA versus TB-Control, whereas alpha-MSH decreased 64% in ARC and 29% in paraventricular nucleus (PVN). Omega-3FA diet in anorexia (TB-omega-3FA vs R-omega-3FA) produced similar qualitative changes of NPY (22% increase) and alpha-MSH (31% decrease) in ARC, with concomitant decrease of 37% in 5-HT(1B)-receptors in PVN, confirming the influence of omega-3FA on the hypothalamic food intake modulators. However, after tumor resection (TB-Control vs R-Control) a 97% increase in NPY and a 62% decrease in alpha-MSH occurred that was significantly greater than in rats fed omega-3FA diet. CONCLUSION: Tumor resection and omega-3FA modifies hypothalamic food intake activity, up-regulating NPY and down-regulating alpha-MSH and 5-HT(1B)-receptors. Tumor resection in anorexic rats on chow diet restored hypothalamic NPY, alpha-MSH, and food intake quantitatively more than in rats fed omega3FA diet.


Assuntos
Anorexia/tratamento farmacológico , Anorexia/etiologia , Apetite/efeitos dos fármacos , Ácidos Graxos Ômega-3/farmacologia , Ração Animal , Animais , Regulação para Baixo , Ingestão de Alimentos , Hipotálamo/fisiologia , Masculino , Neoplasias/complicações , Neoplasias/cirurgia , Neuropeptídeo Y/biossíntese , Ratos , Ratos Endogâmicos F344 , Receptor 5-HT1B de Serotonina/biossíntese , Regulação para Cima
10.
Curr Opin Clin Nutr Metab Care ; 8(4): 403-7, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15930965

RESUMO

PURPOSE OF REVIEW: To review the mechanisms of action of omega-3 fatty acids and their role in the brain, as well as their therapeutic implications in anorexia. RECENT FINDINGS: Recent studies have demonstrated that omega-3 fatty acids modulate changes in the concentrations and actions of several orexigenic and anorexigenic neuropeptides in the brain, including neuropeptide Y, alpha-melanocyte stimulating hormone and the neurotransmitters serotonin and dopamine. In patients with acute and chronic inflammatory conditions, low tissue concentrations of omega-3 fatty acids and high concentrations of proinflammatory cytokines are found, in association with anorexia and decreased food intake. The data suggest that omega-3 fatty acid supplementation suppresses proinflammatory cytokine production and improves food intake by normalizing hypothalamic orexigenic peptides and neurotransmitters. SUMMARY: Based on current data, omega-3 fatty acid supplementation has a role in the treatment of anorexia by stimulating the production and release of orexigenic neurotransmitters in food intake regulatory nuclei in the hypothalamus.


Assuntos
Anorexia/dietoterapia , Encéfalo/metabolismo , Ácidos Graxos Ômega-3/fisiologia , Ácidos Graxos Ômega-3/uso terapêutico , Neurotransmissores/metabolismo , Citocinas/metabolismo , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Humanos
11.
Brain Res ; 1046(1-2): 157-64, 2005 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-15927553

RESUMO

In cancer anorexia, a decrease in food intake (FI) occurs concomitant with changes in orexigenic peptides such as neuropeptide Y (NPY) and anorexigenic peptides such as alpha-melanocyte-stimulating hormone (alpha-MSH) and anorexigenic neurotransmitter serotonin. omega-3 Fatty acid (omega-3FA) inhibits cytokine synthesis, and delays tumor appearance, tumor growth, and onset of anorexia in tumor-bearing rats. We hypothesize that, in cancer anorexia, omega-3FA is associated with quantitative reversal of hypothalamic NPY, alpha-MSH, and serotonin receptor (5-HT(1B)-receptor) enhancing FI. Fischer rats were divided into: MCA tumor bearing fed chow (TB-Chow) or omega-3FA diet (TB-omega-3FA) and controls: non-tumor bearing fed chow (NTB-Chow) or omega-3FA diet (NTB-omega-3FA). Rats were euthanized at anorexia and brains were removed for hypothalamic immunohistochemical study, using NPY, alpha-MSH, and 5-HT(1B)-receptor-specific antibodies and slides assessed by image analysis. Immunostaining specificity was controlled by omission of primary or secondary antibodies and pre-absorption test. At anorexia, FI decreased (P < 0.05) in TB-Chow but did not change in TB-omega-3FA rats. In TB-omega-3FA vs. TB-Chow, NPY immunoreactivity increased 38% in arcuate nucleus (ARC; P < 0.05), and 50% in magnocellular paraventricular nucleus (mPVN; P < 0.05). alpha-MSH decreased 64% in ARC and 29% in mPVN (P < 0.05). 5-HT(1B)-receptor immunoreactivity decreased 13% only in supraoptic nucleus (P < 0.05). No immunoreactivity was found in the control sections. omega-3FA modified hypothalamic peptides and 5-HT-(1B)-receptor immunoreactivity at anorexia, concomitant with an increase in FI, were probably mediated by omega-3FA inhibition of tumor-induced cytokines.


Assuntos
Anorexia/metabolismo , Regulação do Apetite/fisiologia , Ácidos Graxos Ômega-3/fisiologia , Hipotálamo/metabolismo , Sarcoma Experimental/metabolismo , Análise de Variância , Animais , Anorexia/etiologia , Anorexia/prevenção & controle , Gorduras na Dieta/uso terapêutico , Ácidos Graxos Ômega-3/uso terapêutico , Imuno-Histoquímica , Masculino , Neuropeptídeo Y/metabolismo , Ratos , Ratos Endogâmicos F344 , Receptor 5-HT1B de Serotonina/metabolismo , Sarcoma Experimental/complicações , Sarcoma Experimental/dietoterapia , Serotonina/metabolismo , Neoplasias de Tecidos Moles/complicações , Neoplasias de Tecidos Moles/dietoterapia , Neoplasias de Tecidos Moles/metabolismo , alfa-MSH/metabolismo
12.
Surgery ; 136(2): 270-6, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15300190

RESUMO

BACKGROUND: Cancer anorexia is influenced by the neuropeptidergic and monoaminergic systems. We hypothesize that serotonin (5-HT), dopamine (DA) and neuropeptide Y (NPY) concentrations in paraventricular (PVN), ventromedial (VMN), and lateral hypothalamus (LHA) areas are abnormal in tumor-bearing rats. METHODS: Fifty-five Fischer rats (240-280 g) were divided into MCA tumor-bearing (TB), nontumor-bearing (NTB), pair-fed (PF), TB sacrificed at the end of experiment (TB-Terminal), TB resection (TB-Resection), NTB sham-operated (NTB-Sham) and pair-fed sham-operated (PF-Sham) groups. Rats were sacrificed at onset of anorexia (TB, NTB, and PF) and 9 days after tumor resection (TB-Resection, NTB-Sham, PF-Sham, and TB-Terminal). Bilateral PVN, VMN, and LHA were harvested for NPY, 5-HT, and DA analyses. RESULTS: Food intake decreased in TB versus NTB (P < .05). In TB versus NTB, an increase of 5-HT in PVN and VMN occurred with a concomitant decrease in DA. NPY in PVN, VMN, and LHA decreased (P < .05). In TB-Resection versus NTB-Sham, 5-HT, DA, NPY, and FI normalized after tumor resection. CONCLUSIONS: Cancer anorexia is associated with abnormal serotonin, dopamine, and NPY concentrations, expressed by an increase in 5-HT and a decrease in DA and NPY. After tumor resection, these alterations normalized, providing evidence that the levels of these substances change with anorexia in tumor-bearing rats.


Assuntos
Dopamina/análise , Hipotálamo/química , Neoplasias Experimentais/metabolismo , Neuropeptídeo Y/análise , Serotonina/análise , Animais , Composição Corporal , Peso Corporal , Ingestão de Alimentos , Masculino , Neoplasias Experimentais/cirurgia , Ratos , Ratos Endogâmicos F344
13.
J Biol Chem ; 278(30): 27896-902, 2003 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-12730204

RESUMO

Plasma membrane-associated sialidase is a key enzyme for ganglioside hydrolysis, thereby playing crucial roles in regulation of cell surface functions. Here we demonstrate that mice overexpressing the human ortholog (NEU3) develop diabetic phenotype by 18-22 weeks associated with hyperinsulinemia, islet hyperplasia, and increased beta-cell mass. As compared with the wild type, insulin-stimulated phosphorylation of the insulin receptor (IR) and insulin receptor substrate I was significantly reduced, and activities of phosphatidylinositol 3-kinase and glycogen synthase were low in transgenic muscle. IR phosphorylation was already attenuated in the younger mice before manifestation of hyperglycemia. Transient transfection of NEU3 into 3T3-L1 adipocytes and L6 myocytes caused a significant decrease in IR signaling. In response to insulin, NEU3 was found to undergo tyrosine phosphorylation and subsequent association with the Grb2 protein, thus being activated and causing negative regulation of insulin signaling. In fact, accumulation of GM1 and GM2, the possible sialidase products in transgenic tissues, caused inhibition of IR phosphorylation in vitro, and blocking of association with Grb2 resulted in reversion of impaired insulin signaling in L6 cells. The data indicate that NEU3 indeed participates in the control of insulin signaling, probably via modulation of gangliosides and interaction with Grb2, and that the mice can serve as a valuable model for human insulin-resistant diabetes.


Assuntos
Membrana Celular/enzimologia , Insulina/metabolismo , Neuraminidase/biossíntese , Neuraminidase/metabolismo , Adipócitos/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Cromatografia em Camada Fina , DNA Complementar/metabolismo , Detergentes/farmacologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Gangliosídeos/metabolismo , Glucose/metabolismo , Teste de Tolerância a Glucose , Glicogênio Sintase/metabolismo , Humanos , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Transgênicos , Músculos/citologia , Músculos/metabolismo , Neuraminidase/química , Octoxinol/farmacologia , Fenótipo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Testes de Precipitina , Ratos , Receptor de Insulina/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Fatores de Tempo , Transfecção , Transgenes , Tirosina/metabolismo
14.
Anal Biochem ; 301(1): 65-74, 2002 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11811968

RESUMO

Phosphorylation of retinoblastoma protein (pRB) by cyclin-dependent kinases (CDKs) at multiple sites leads to activation of transcription of cell-cycle-related genes. Cyclin/CDK complexes thus play a pivotal role in the regulation of progression from G1 to S phase. In the present study, we developed a nonradioactive, sandwich enzyme-linked immunosorbent assay (ELISA) system for measuring activities of cyclin/CDK complexes, in which the immobilized monoclonal antibody works as a trap for phosphorylated pRB containing phosphorylated amino acids at specific sites. For this purpose, we raised monoclonal antibodies that are highly specific to ppRB phosphorylated at Ser780, Thr356, or Ser612 and used them as detectors for the individual reaction products by cyclin/CDK complexes. In particular, this approach proved useful for cyclin D1/CDK4 that specifically recognizes Ser780 in pRB with only very limited phosphorylation of a conventional substrate, histone H1. The study revealed the newly developed sandwich ELISA system to have advantages over the current radioisotope assay in terms of sensitivity, precision, and rapidity. It should find application for inhibitor screening and drug discovery related to CDKs.


Assuntos
Anticorpos Monoclonais/imunologia , Quinases Ciclina-Dependentes/análise , Ensaio de Imunoadsorção Enzimática/métodos , Proteína do Retinoblastoma/imunologia , Animais , Especificidade de Anticorpos , Linhagem Celular , Quinases Ciclina-Dependentes/antagonistas & inibidores , Quinases Ciclina-Dependentes/metabolismo , Ciclinas/metabolismo , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/farmacologia , Insetos/citologia , Substâncias Macromoleculares , Fosforilação , Proteínas Recombinantes/imunologia , Especificidade por Substrato
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