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1.
J Eur Acad Dermatol Venereol ; 33 Suppl 8: 6-10, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31833607

RESUMO

BACKGROUND: Population-based incidence and mortality studies of cutaneous squamous cell carcinoma (SCC) have been few owing to the commonness of the disease, and rare deaths making accurate mortality statistics difficult. OBJECTIVES: Our aim was to summarize SCC incidence and mortality in populations across three continents, exemplified by Australia, the United States (US) and Germany. METHODS: We estimated age-specific and age-standardized (Australian Standard 2001 Population) incidence and mortality rates per 100 000 person-years. RESULTS: Squamous cell carcinoma incidence is plateauing or falling in Australia, stable in the United States (2013-2015) and rising in Germany (2007-2015). Current incidence estimates in men and women are 341 and 209, 497 and 296, and 54 and 26, respectively, for the three countries. Incidence increases strongly with age in all countries. Mortality of non-melanoma skin cancer appears to be increasing in Germany and stable in Australia (unavailable for the US population). CONCLUSIONS: Squamous cell carcinoma is an important health issue, particularly among older men, with incidence exceeding most other cancers. More precise and uniform population-based studies of incidence and mortality are needed to better quantify the impact of SCC on healthcare systems worldwide and to gauge the effect of new treatments such as anti-PD1 therapy on mortality.


Assuntos
Carcinoma de Células Escamosas/epidemiologia , Neoplasias Cutâneas/epidemiologia , Idoso , Austrália/epidemiologia , Carcinoma de Células Escamosas/mortalidade , Feminino , Alemanha/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Neoplasias Cutâneas/mortalidade , Estados Unidos/epidemiologia
2.
Cephalalgia ; 35(6): 508-15, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25179294

RESUMO

BACKGROUND: Hypersensitivity to light, noise and odour are pivotal clinical characteristics of migraine associated with enhanced cortical excitability and dysfunctional habituation. However, little is known about the integrity of basic sensory functioning in migraine on a population-based level. METHODS: A total of 129 participants with migraine (105 without aura, MwoA, 24 with aura, MA) and 522 healthy controls without headache 12 months prior to baseline were included from a sample of the DMKG study and underwent standardised clinical sensory testing of smell, taste, hearing and vision. RESULTS: After adjustment for age, sex, smoking status and history of head injuries, the chance of impaired colour perception was significantly higher in MA compared to controls (odds ratio, OR=3.20; 95% CI=1.20-8.53) and MwoA (OR=3.62; 95% CI=1.31-9.97). Compared to MwoA, MA also had an increased chance of smell (OR=3.20; 95% CI=0.98-10.42) and taste (OR=2.58; 95% CI=0.90-7.40) impairment. CONCLUSIONS: In this cross-sectional, population-based study on sensory functioning in migraine participants, colour vision was impaired interictally in MA compared to MwoA and controls.


Assuntos
Defeitos da Visão Cromática/etiologia , Enxaqueca com Aura/complicações , Enxaqueca com Aura/fisiopatologia , Estudos Transversais , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade
3.
Diabetologia ; 51(6): 1025-34, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18408913

RESUMO

AIMS/HYPOTHESIS: Type 2 diabetes mellitus is a common age-dependent disease. We discovered that male offspring of non-diabetic C57BL/6 and DBA/2 mice, called JYD mice, develop type 2 diabetes when they grow old. JYD mice show characteristics of insulin resistance, hyperglycaemia and hyperinsulinaemia in old age without obesity. We postulated that the mechanism of age-dependent type 2 diabetes in this model relates to caveolin-1 status in skeletal muscle, which appears to regulate insulin sensitivity in the mice. METHODS: We compared insulin sensitivity in aged C57BL/6 and JYD mice using glucose and insulin tolerance tests and (18)F-fluorodeoxyglucose positron emission tomography. We also determined insulin signalling molecules and caveolin proteins using western blotting, and altered caveolin-1 levels in skeletal muscle of C57BL/6 and JYD mice using viral vector systems, to examine the effect of this on insulin sensitivity. RESULTS: In 30-week-old C57BL/6 and JYD mice, the basal levels of IRS-1, Akt and peroxisome proliferator-activated receptor-gamma decreased, as did insulin-stimulated phosphorylation of Akt and insulin receptor beta. However, caveolin-1 was only increased about twofold in 30-week-old JYD mice as compared with 3-week-old mice, whereas an eightfold increase was seen in C57BL/6 mice. Downregulation of caveolin-1 production in C57BL/6 mice caused severe impairment of glucose and insulin tolerance. Upregulation of caveolin-1 in aged diabetic JYD mice significantly improved insulin sensitivity with a concomitant increase of glucose uptake in the skeletal muscle. CONCLUSIONS/INTERPRETATION: The level of skeletal muscle caveolin-1 is correlated with the progression of age-dependent type 2 diabetes in JYD mice.


Assuntos
Envelhecimento/fisiologia , Caveolina 1/fisiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Músculo Esquelético/fisiopatologia , Animais , Transporte Biológico , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Cruzamentos Genéticos , Modelos Animais de Doenças , Feminino , Fluordesoxiglucose F18/metabolismo , Teste de Tolerância a Glucose , Insulina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Tomografia por Emissão de Pósitrons
4.
Diabetologia ; 50(10): 2147-55, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17676307

RESUMO

AIMS/HYPOTHESIS: Expression of T helper (Th)1 cytokine mRNA in pregnant women is known to be inversely correlated with serum human chorionic gonadotropin (hCG). Type 1 diabetes is a Th1-mediated autoimmune disease, in which intervention at an early stage of the autoimmune process can prevent disease progression. We hypothesised that immune modulation by treating young NOD mice with hCG may prevent diabetes. METHODS: Female NOD mice were treated with hCG or recombinant hCG from 3 to 15 weeks of age and the incidence of diabetes and development of insulitis was determined. CD4(+) and CD8(+) T cell populations, T cell proliferation, cytokine production and CD4(+)CD25(+) regulatory T cells were examined and adoptive transfer experiments were performed. RESULTS: Both purified and recombinant hCG prevented development of diabetes in NOD mice. hCG decreased the proportion and number of CD4(+) and CD8(+) T cells and inhibited T cell proliferative responses against beta cell antigens. hCG treatment suppressed IFN-gamma production, but increased IL-10 and TGF-beta production in splenocytes stimulated with anti-CD3 antibody. hCG treatment also suppressed TNF-alpha production in splenocytes stimulated with lipopolysaccharide. Furthermore, hCG treatment increased the CD4(+)CD25(+)/CD4(+) T cell ratio in spleen and pancreatic lymph nodes. Depletion of CD4(+)CD25(+) T cells from splenocytes of hCG-treated NOD mice abolished their preventive effect on diabetes transfer. CONCLUSIONS/INTERPRETATION: We conclude that hCG has an immunomodulatory effect by downregulating effector cells, including Th1 cells, CD8(+) T cells and macrophages, and increasing the CD4(+)CD25(+)/CD4(+) T cell ratio, thus preventing autoimmune diabetes in NOD mice.


Assuntos
Gonadotropina Coriônica/uso terapêutico , Diabetes Mellitus Tipo 1/prevenção & controle , Fatores Imunológicos/uso terapêutico , Linfócitos T Auxiliares-Indutores/imunologia , Transferência Adotiva , Animais , Gonadotropina Coriônica/imunologia , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/terapia , Feminino , Citometria de Fluxo , Linfonodos/imunologia , Transfusão de Linfócitos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Gravidez , Baço/transplante
5.
Diabetologia ; 49(10): 2437-48, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16896937

RESUMO

AIMS/HYPOTHESIS: Cinnamon extracts have anti-diabetic effects. Phenolic acids, including hydrocinnamic acids, were identified as major components of cinnamon extracts. Against this background we sought to develop a new anti-diabetic compound using derivatives of hydroxycinnamic acids purified from cinnamon. METHODS: We purified hydroxycinnamic acids from cinnamon, synthesised a series of derivatives, and screened them for glucose transport activity in vitro. We then selected the compound with the highest glucose transport activity in epididymal adipocytes isolated from male Sprague-Dawley rats in vitro, tested it for glucose-lowering activity in vivo, and studied the mechanisms involved. RESULTS: A naphthalenemethyl ester of 3,4-dihydroxyhydrocinnamic acid (DHH105) showed the highest glucose transport activity in vitro. Treatment of streptozotocin-induced diabetic C57BL/6 mice and spontaneously diabetic ob/ob mice with DHH105 decreased blood glucose levels to near normoglycaemia. Further studies revealed that DHH105 increased the maximum speed of glucose transport and the translocation of glucose transporter 4 (GLUT4, now known as solute carrier family 2 [facilitated glucose transporter], member 4 [SLC2A4]) in adipocytes, resulting in increased glucose uptake. In addition, DHH105 enhanced phosphorylation of the insulin receptor-beta subunit and insulin receptor substrate-1 in adipocytes, both in vitro and in vivo. This resulted in the activation of phosphatidylinositol 3-kinase and Akt/protein kinase B, contributing to the translocation of GLUT4 to the plasma membrane. CONCLUSIONS/INTERPRETATION: We conclude that DHH105 lowers blood glucose levels through the enhancement of glucose transport, mediated by an increase in insulin-receptor signalling. DHH105 may be a valuable candidate for a new anti-diabetic drug.


Assuntos
Cinnamomum zeylanicum , Ácidos Cumáricos/farmacologia , Transportador de Glucose Tipo 4/metabolismo , Glucose/metabolismo , Naftalenos/farmacologia , Adipócitos/efeitos dos fármacos , Adipócitos/fisiologia , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Epididimo , Teste de Tolerância a Glucose , Transportador de Glucose Tipo 4/efeitos dos fármacos , Glicogênio/biossíntese , Cinética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Fosfatidilinositol 3-Quinases/metabolismo , Transporte Proteico/efeitos dos fármacos
6.
Cell Mol Life Sci ; 59(11): 1892-901, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12530520

RESUMO

Glutamic acid decarboxylase (GAD) is considered to be one of the strongest candidate autoantigens involved in triggering beta-cell-specific autoimmunity. The majority of recent onset type 1 diabetes patients and pre-diabetic subjects have anti-GAD antibodies in their sera, as do nonobese diabetic (NOD) mice, one of the best animal models for human type I diabetes. Immunization of young NOD mice with GAD results in the prevention or delay of the disease as a result of tolerizing autoreactive T cells. Autoimmune diabetes can also be prevented by the suppression of GAD expression in antisense GAD transgenic mice backcrossed with NOD mice for seven generations. These results support the hypothesis that GAD plays an important role in the development of T-cell-mediated autoimmune diabetes. However, there is some controversy regarding the role of GAD in the pathogenesis of diabetes. Whether GAD truly plays a key role in the initiation of this disease remains to be determined. The examination of the development of insulitis and diabetes in beta-cell-specific GAD knockout NOD mice will answer this remaining question.


Assuntos
Diabetes Mellitus Tipo 1/enzimologia , Diabetes Mellitus Tipo 1/etiologia , Glutamato Descarboxilase/imunologia , Sequência de Aminoácidos , Animais , Autoantígenos/genética , Autoantígenos/imunologia , Autoimunidade , Diabetes Mellitus Tipo 1/imunologia , Enterovirus Humano B/genética , Glutamato Descarboxilase/genética , Humanos , Camundongos , Camundongos Endogâmicos NOD , Mimetismo Molecular/genética , Dados de Sequência Molecular , Alinhamento de Sequência , Linfócitos T/imunologia
7.
Biol Pharm Bull ; 24(5): 480-3, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11379764

RESUMO

2-1(4-Cyanophenyl)aminol-3-chloro-1,4-naphthalenedione (NQ-Y15) is a dual action drug which acts as a thromboxane A2 (TXA2) synthase inhibitor and TXA2/PGH2 receptor antagonist. In the present study, we examined the effects of NQ-Y15 on Ca2+ mobilization, which is the common event in various types of platelet activation, in arachidonic acid (AA)-stimulated rat platelets. The elevation of cytosolic Ca2+ concentration ([Ca2+]i) induced by AA was inhibited by NQ-Y15 in a concentration-dependent manner. This inhibition-effect of NQ-Y15 was found to be based on the suppression of the rise in [Ca2+]i by the inhibition of both Ca2+ release from internal stores and Ca2+ influx from the extracellular space. Our successive trial was focused on the role of cyclic AMP (cAMP) in the action of NQ-Y15, because cAMP was reported to be increased by dual action drugs such as picotamide and to inhibit the increase in [Ca2+]i. NQ-Y15 was confirmed to increase cAMP in AA-stimulated rat platelets. These results suggested that NQ-Y15 might inhibit the rise in [Ca2+]i in AA-treated rat platelets by increasing cAMP, which is involved in the inhibition of platelet activation.


Assuntos
Plaquetas/efeitos dos fármacos , Cálcio/metabolismo , AMP Cíclico/biossíntese , Inibidores Enzimáticos/farmacologia , Naftoquinonas/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Tromboxano-A Sintase/antagonistas & inibidores , Animais , Ácido Araquidônico/farmacologia , Plaquetas/metabolismo , Feminino , Prostaglandina D2/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Tromboxanos/antagonistas & inibidores
8.
Biochem Pharmacol ; 58(11): 1705-12, 1999 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-10571244

RESUMO

The effects of brazilin on glucose transport into isolated rat epididymal adipocytes were investigated. Brazilin increased [3H]2-deoxy-D-glucose uptake, which was characterized by an increase in Vmax with no effect on the Km value. Phenylarsine oxide, which inhibits the translocation of glucose transporters, decreased brazilin-stimulated glucose transport to the basal level. The inhibition of phosphatidylinositol 3-kinase (PI3-kinase) with wortmannin also blocked brazilin-stimulated glucose transport. Western blot analysis with an anti-GLUT4 antibody revealed that brazilin increased the translocation of GLUT4 from intracellular pools to the plasma membrane. Brazilin, in combination with phorbol ester, showed an additive effect on glucose transport. The stimulating effect of phorbol ester on glucose transport was inhibited by staurosporine, but the effect of brazilin remained unchanged. Protein kinase C activity was not influenced by brazilin treatment. The inhibition of protein synthesis showed no effect on brazilin-stimulated glucose transport, and GLUT4 content in the total membrane fraction was not altered as a result of treatment with brazilin for 4 hr. Metabolic labeling of GLUT4 with [35S]methionine showed that de novo synthesis of GLUT4 was not induced by brazilin. These data suggest that brazilin may increase glucose transport by recruitment of GLUT4 from intracellular pools to the plasma membrane of adipocytes via the activation of PI3-kinase. However, the effect of brazilin may not be mediated by GLUT4 synthesis and protein kinase C activation.


Assuntos
Adipócitos/efeitos dos fármacos , Benzopiranos/farmacologia , Hipoglicemiantes/farmacologia , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas Musculares , Adipócitos/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Epididimo/citologia , Glucose/metabolismo , Transportador de Glucose Tipo 4 , Técnicas In Vitro , Masculino , Proteínas de Transporte de Monossacarídeos/biossíntese , Proteína Quinase C/metabolismo , Ratos , Ratos Sprague-Dawley
9.
Arch Pharm Res ; 21(2): 140-6, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9875421

RESUMO

Hypoglycemic action of brazilin was found to be based on the improvement of peripheral glucose utility, and this action might be correlated with the insulin action pathway. In the present study we investigated the effect of brazilin on the insulin receptor autophosphorylation, protein kinase C (PKC), protein phosphatase and insulin receptor serine kinase in order to confirm whether the hypoglycemic mechanism is concerned with insulin action pathway. Brazilin was found to inhibit PKC and insulin receptor serine kinase, which are involved in the regulation of insulin signal pathway. But any significant effect was not shown on insulin receptor tyrosine kinase activity, autophosphorylation and phosphatase activity. These findings suggest that brazilin might enhance insulin receptor function by decreasing serine phosphorylation, which might mediate hypoglycemic effect of brazilin.


Assuntos
Benzopiranos/farmacologia , Inibidores Enzimáticos/farmacologia , Fígado/enzimologia , Proteína Quinase C/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Insulina/metabolismo , Fígado/efeitos dos fármacos , Masculino , Fosfoaminoácidos/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação , Ratos , Ratos Sprague-Dawley , Receptor de Insulina
10.
Planta Med ; 63(5): 405-8, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9342942

RESUMO

Previously we reported that brazilin, the main principle of Caesalpinia sappan, was able to improve the altered immune functions caused by halothane administration in mice. To elucidate the mechanisms of its immunomodulating activities, the effects of brazilin on the functions of T cells and splenic cellularity were investigated. Brazilin decreased splenic cellularity and IL-2 production which had been augmented in mice treated with halothane (21.5% in olive oil, 10 mmol/kg) for 4 consecutive days whereas the reduced expression of IL-2 receptors by ConA or standard IL-2 was increased by brazilin treatment. These data indicate that halothane induced a dysfunction of T cells resulting in abnormal immune responses and these altered immune functions might be improved mainly by affecting the function of T cells.


Assuntos
Benzopiranos/farmacologia , Halotano/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Animais , Células Cultivadas , Concanavalina A/farmacologia , Fabaceae , Feminino , Interleucina-2/biossíntese , Interleucina-2/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Lectinas de Plantas , Plantas Medicinais , Receptores de Interleucina-2/biossíntese , Baço/imunologia , Linfócitos T/imunologia
11.
Biochem Pharmacol ; 54(2): 259-68, 1997 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-9271330

RESUMO

The effects of 2-[(4-acetylphenyl)amino]-3-chloro-1,4-naphthalenedione (NQ-Y15), a synthetic 1,4-naphthoquinone derivative, on platelet activity and its mechanism of action were investigated. NQ-Y15 caused a concentration-dependent inhibition of the aggregation induced by thrombin, collagen, arachidonic acid (AA), and A23187. The IC50 values of NQ-Y15 on thrombin (0.1 U/mL)-, collagen (10 microg/mL)-, AA (50 microM)-, and A23187 (2 microM)-induced aggregation were 36.2 +/- 1.5, 6.7 +/- 0.7, 35.4 +/- 1.7, and 93.1 +/- 1.4 microM, respectively. NQ-Y15 also inhibited thrombin-, collagen-, AA-, and A23187-stimulated serotonin secretion in a concentration-dependent manner. However, a high concentration (100 microM) of NQ-Y15 showed no significant inhibitory effect on ADP-induced primary aggregation, which is independent of thromboxane A2 (TXA2) production in rat platelets. In fura-2-loaded platelets, the elevation of intracellular free calcium concentration stimulated by AA, thrombin, and 4-bromo-A23187 was inhibited by NQ-Y15 in a concentration-dependent manner. The formation of TXA2 caused by AA, thrombin, and collagen was inhibited significantly by NQ-Y15. NQ-Y15 inhibited TXA2 synthase in intact rat platelets, since this agent reduced the conversion of prostaglandin (PG) H2 to TXA2. Similarly, NQ-Y15 selectively inhibited the TXA2 synthase activity in human platelet microsomes, whereas it had no effect on activity of phospholipase A2, cyclooxygenase, and PGI2 synthase in vitro. NQ-Y15 inhibited platelet aggregation induced by the endoperoxide analogue U46619 in human platelets, indicating TXA2 receptor antagonism, possibly of a competitive nature. These results suggest that the antiplatelet effect of NQ-Y15 is due to a combination of TXA2 synthase inhibition with TXA2 receptor blockade, and that it may be useful as an antithrombotic agent.


Assuntos
Plaquetas/efeitos dos fármacos , Naftoquinonas/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Receptores de Tromboxanos/antagonistas & inibidores , Tromboxano-A Sintase/antagonistas & inibidores , Animais , Plaquetas/metabolismo , Cálcio/metabolismo , Feminino , Prostaglandina-Endoperóxido Sintases/metabolismo , Ratos , Ratos Sprague-Dawley , Serotonina/metabolismo , Tromboxano A2/antagonistas & inibidores , Tromboxano B2/metabolismo
12.
Biochem Pharmacol ; 54(1): 97-101, 1997 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-9296355

RESUMO

Brazilin increased [3H]2-deoxyglucose uptake in isolated rat epididymal adipocytes. The fact that calcium may be required for the stimulatory effects of insulin on glucose transport suggests that brazilin might also require calcium for its glucose transport-stimulating action. Changes in the concentration of extracellular calcium had no significant effect on brazilin-induced glucose transport. Nifedipine and verapamil decreased brazilin-induced glucose transport, and quin2-AM abolished the effect of brazilin on glucose transport. A23187, however, showed no effect on brazilin action. 45Ca2+ uptake into adipocytes was not influenced by brazilin treatment, and trifluoperazine significantly inhibited the effect of brazilin on glucose transport. These data suggest that calmodulin and the maintenance of the intracellular calcium concentration, rather than an increase in it, may be essential for the stimulatory action of brazilin on glucose transport.


Assuntos
Adipócitos/efeitos dos fármacos , Benzopiranos/farmacologia , Cálcio/farmacologia , Glucose/metabolismo , Hipoglicemiantes/farmacologia , Adipócitos/metabolismo , Animais , Benzopiranos/antagonistas & inibidores , Transporte Biológico/efeitos dos fármacos , Calcimicina/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Calmodulina/metabolismo , Membrana Celular/metabolismo , Relação Dose-Resposta a Droga , Epididimo/metabolismo , Antagonistas da Insulina/farmacologia , Masculino , Nifedipino/farmacologia , Ratos , Ratos Sprague-Dawley , Trifluoperazina/farmacologia , Verapamil/farmacologia
13.
Mol Cells ; 7(2): 244-50, 1997 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-9163740

RESUMO

Most methods for the diagnosis of hepatitis B virus (HBV) infection largely depend on viral DNA detection by polymerase chain reaction (PCR) or radioimmunological assay of viral antigens or antibodies. The quality assurance program recently established in Europe reported that PCR-mediated HBV DNA detection methods used in many laboratories produced a high rate of false-positive and false-negative results. Thus, we attempted to improve the conditions of current PCR methods for detection of HBV DNA. In the present study, we applied a recently developed method of releasing HBV DNA from virion by NaOH treatment of patient serum. Using four different primer sets specific to the HBV core region, we found that the sensitivity of first-round PCR can be improved by more than two orders of magnitude depending on the primers. The second round of PCR using nested primers was sensitive enough to detect up to 10(-6) pg of the HBV DNA, which is equivalent to approximately 3 copies of the HBV genome. Among the approximately 800 HBV-infected patient sera investigated in our laboratory, more than 60% of the tested samples gave positive results in the first-round PCR. The rate of positive results obtained using our experimental conditions is very high in comparison with other reports. The reamplification of the first-round PCR reaction mixture with the nested primers produced practically 100% positive results. For diagnosis of HBV infection, we routinely used 1 microliter of patient serum, which was found to be optimum in our laboratory. Surprisingly, from 20% of our positive results, even serum diluted to 1/100 (0.01 microliter) produced a stronger signal than 1 microliter. This observation suggests that direct PCR amplification of HBV DNA released from serum by NaOH treatment has to be compensated by other DNA detection methods for correct quantitation. In order to eliminate the false positive signal resulting from the carry-over due to massive screening of a large number of samples, PCR reaction mixture containing 8-methoxypsoralen was exposed to ultraviolet light prior to thermal cycle amplification. This exercise did not decrease the sensitivity of the detection method, but almost completely removed the false positive results caused by contaminated templates. We are in the process of improving PCR-mediated HBV DNA detection methods to attain more reliable and easily applicable methods.


Assuntos
DNA Viral/sangue , DNA Viral/genética , Vírus da Hepatite B/genética , Hepatite B/diagnóstico , Reação em Cadeia da Polimerase/métodos , Sequência de Bases , Primers do DNA/genética , Estudos de Avaliação como Assunto , Reações Falso-Positivas , Hepatite B/virologia , Humanos , Metoxaleno , Reação em Cadeia da Polimerase/estatística & dados numéricos , Sensibilidade e Especificidade
14.
Mol Cells ; 7(6): 742-8, 1997 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-9509415

RESUMO

Insulin has pleiotropic effects on the regulation of cellular growth, differentiation, and metabolism. The biochemical events ultimately leading to cell proliferation after insulin treatment have been demonstrated in detail by numerous research groups. However, depending on cell types, it has been shown that insulin has various effects on cell proliferation. Therefore, we attempted to more critically evaluate the effect of insulin on cell proliferation in 3T3 L1 fibroblasts. In this study, we investigated insulin's effect on cell proliferation by using [3H]thymidine incorporation, flow cytometry, and cell counting. In 3T3 L1 fibroblasts studied in 0.5% serum, insulin induced a two-fold increase in [3H]thymidine incorporation over at 48 h, and the maximal rate of DNA synthesis was observed during 8-12 h incubation. The flow cytometric analysis also showed that insulin increased the cell population in the S phase. After insulin treatment for 48 h, cell numbers increased approximately 45% in comparison with 0.5% serum control. Cell division was found to occur only once in 60 h after staining 3T3 L1 fibroblasts with carboxyfluorescein diacetate succinimidyl ester (CFSE). Taken together, this data indicates that insulin stimulated the transit from the G0/G1 to S phase, progressed the cell cycle through the G2/M phase, and increased the cell number. However, under our experimental conditions, cells divided only once in 60 h in the presence of insulin.


Assuntos
Ciclo Celular/efeitos dos fármacos , Insulina/farmacologia , Células 3T3 , Animais , Contagem de Células/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Citometria de Fluxo , Fluoresceínas/metabolismo , Corantes Fluorescentes , Interfase/fisiologia , Camundongos , Mitose/efeitos dos fármacos , Mitose/fisiologia , Fase S/fisiologia , Succinimidas/metabolismo
15.
Planta Med ; 61(4): 297-301, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7480173

RESUMO

Brazilin (7,11b-dihydrobenz[b]indeno-[1,2-d]pyran-3,6a,9,10(6H)- tetrol) was found to have hypoglycemic action and increase glucose metabolism in experimental diabetic animals. In order to investigate the mechanism of hypoglycemic action of brazilin, the effects of brazilin on glucose transport, insulin receptor autophosphorylation, and protein kinase C(PKC) activity in 3T3-L1 cells were studied. Brazilin increased basal glucose transport in 3T3-L1 fibroblasts and adipocytes. However, insulin-stimulated glucose transport was not influenced. Autophosphorylation of the partially purified insulin receptor was not affected by brazilin treatment in 3T3-L1 fibroblasts. However, brazilin decreased the PKC activity in 3T3-L1 fibroblasts and adipocytes.


Assuntos
Adipócitos/metabolismo , Benzopiranos/farmacologia , Glucose/metabolismo , Células 3T3 , Adipócitos/efeitos dos fármacos , Animais , Transporte Biológico/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Insulina/farmacologia , Camundongos , Proteína Quinase C/metabolismo , Receptor de Insulina/metabolismo
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