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1.
J Neurovirol ; 22(4): 472-8, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26733457

RESUMO

Infrastructure for conducting neurological research in resource-limited settings (RLS) is limited. The lack of neurological and neuropsychological (NP) assessment and normative data needed for clinical interpretation impedes research and clinical care. Here, we report on ACTG 5271, which provided neurological training of clinical site personnel and collected neurocognitive normative comparison data in diverse settings. At ten sites in seven RLS countries, we provided training for NP assessments. We collected normative comparison data on HIV- participants from Brazil (n = 240), India (n = 480), Malawi (n = 481), Peru (n = 239), South Africa (480), Thailand (n = 240), and Zimbabwe (n = 240). Participants had a negative HIV test within 30 days before standardized NP exams were administered at baseline and 770 at 6 months. Participants were enrolled in eight strata, gender (female and male), education (<10 and ≥10 years), and age (<35 and ≥35 years). Of 2400 enrolled, 770 completed the 6-month follow-up. As expected, significant between-country differences were evident in all the neurocognitive test scores (p < 0.0001). There was variation between the age, gender, and education strata on the neurocognitive tests. Age and education were important variables for all tests; older participants had poorer performance, and those with higher education had better performance. Women had better performance on verbal learning/memory and speed of processing tests, while men performed better on motor tests. This study provides the necessary neurocognitive normative data needed to build infrastructure for future neurological and neurocognitive studies in diverse RLS. These normative data are a much-needed resource for both clinicians and researchers.


Assuntos
Ensaios Clínicos como Assunto , Cognição/fisiologia , Pessoal de Saúde/educação , Testes de Estado Mental e Demência , Adulto , África , Fatores Etários , Ásia , Disfunção Cognitiva/complicações , Disfunção Cognitiva/psicologia , Países em Desenvolvimento/economia , Escolaridade , Feminino , Infecções por HIV/complicações , Infecções por HIV/psicologia , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Fatores Sexuais , América do Sul , Aprendizagem Verbal/fisiologia
2.
Animal ; 18(6): 101156, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38718708

RESUMO

Gastrointestinal nematodes (GINs) are a significant threat to the sustainability of global sheep production. Periparturient ewes play a key role in GIN epidemiology, with increased GIN faecal egg counts (FECs) in these ewes resulting in heavy pasture contamination that facilitates parasitic gastroenteritis in immunologically naïve lambs later during the grazing period. Traditionally, blanket anthelmintic treatment would suppress GIN egg outputs in these ewes and subsequent pasture contamination. However, farmers are now advised to implement targeted selective treatment (TST) to reduce anthelmintic use and subsequent anthelmintic resistance development, yet, there is currently limited evidence to determine optimal TST strategies in ewes. In this study, the characteristics of 226 ewes on seven Welsh farms were assessed postlambing to identify factors associated with their individual strongyle FECs using negative binomial mixed model analysis. Nemabiome analysis was conducted on 34 ewes across two study farms using the Oxford Nanopore MinIon platform with an aim of identifying factors associated with variations in ewe nemabiome composition within flocks. The best-fitted model of ewe FEC incorporated ewe body condition score, dag score, breed, and an interaction effect between ewe age and litter size as fixed factors. The addition of a mean FEC value for ewes of a specific litter size on each farm further improved model fit and reduced between-farm variance in the model. Nemabiome analysis revealed significant variation in within flock nemabiome diversity on individual farms, with significantly reduced nemabiome diversity recorded in ewes exhibiting dags and in twin-bearing ewes on respective farms, whilst T. circumcincta was present as a significantly higher proportion of the nemabiome in Suffolk ewes and twin bearing ewes (P < 0.05) in respective flocks. Our data demonstrate that commonly recorded ewe characteristics can be exploited to predict individual periparturient ewe FEC and subsequently may be used as a guide for TST strategies on sheep farms once specific TST thresholds are identified to deliver the optimal balance between minimal pasture contamination and maximal GIN refugia. This study is the first to utilise Oxford Nanopore MinIon sequencing to evaluate the nemabiome of sheep, and to molecularly assess the nemabiome of individual ruminants within a flock/herd, with results indicating that significant within flock variations in nemabiome composition which may have implications for TST and flock management strategies.


Assuntos
Fezes , Infecções por Nematoides , Contagem de Ovos de Parasitas , Doenças dos Ovinos , Animais , Ovinos , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/prevenção & controle , Feminino , Infecções por Nematoides/veterinária , Fezes/parasitologia , Contagem de Ovos de Parasitas/veterinária , Anti-Helmínticos/uso terapêutico , Nematoides/efeitos dos fármacos , Período Periparto , Criação de Animais Domésticos/métodos , Gravidez , País de Gales
3.
Phys Rev Lett ; 109(9): 095503, 2012 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-23002847

RESUMO

High-resolution x-ray powder-diffraction experiments were performed on europium metal at high pressure up to 50 GPa. At variance with previous reports, the hcp phase of Eu was observed to be stable not only to 18 GPa, but to 31.5 GPa. At 31.5(5) GPa, europium transforms to a phase (Eu-IV) with an incommensurately modulated monoclinic crystal structure with superspace group C2/c(q(1)0q(3))00. This new phase was observed to be stable to ~37.0 GPa, where another phase transition was observed. Eu-IV is the first phase in the lanthanide elements with an incommensurate crystal structure.

4.
HIV Med ; 10(2): 103-10, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19200173

RESUMO

OBJECTIVES: Antiretroviral toxic neuropathy (ATN) is associated with dideoxynucleoside reverse transcriptase inhibitor use in patients infected with HIV, possibly as a result of mitochondrial toxicity. Acetyl-l-carnitine (ALC) has been linked to symptomatic improvement in ATN. We present an open-label single-arm pilot study to evaluate changes in intra-epidermal nerve fibre (IENF) density and mitochondrial DNA (mtDNA) copies/cell among subjects treated with 3000 mg ALC daily. METHODS: Punch skin biopsies were examined at baseline and after 24 weeks of therapy. Participants reported neuropathic symptoms using the Gracely Pain Intensity Score. Neurological examinations were completed. RESULTS: Twenty-one subjects completed the study. ALC was generally well tolerated. The IENF density did not change in cases completing 24 weeks of ALC therapy, with median (90% confidence interval) IENF changes of -1.70 (-3.50, infinity) (P=0.98) and 2.15 (-0.10, infinity) (P=0.11) for the distal leg and proximal thigh, respectively. Fat mtDNA copies/cell did not change with therapy. Improvements in neuropathic pain (P<0.01), paresthesias (P=0.01), and symptoms of numbness (P<0.01) were noted. Similarly, improvement was noted on the Gracely Pain Intensity Score. CONCLUSIONS: ALC therapy coincided with improvements in subjective measures of pain in this open-label single-arm study. However, changes were not observed in objective measures of IENF density or mtDNA levels, providing little objective support for use of ALC in this setting.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Acetilcarnitina/efeitos adversos , HIV-1 , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Inibidores da Transcriptase Reversa/efeitos adversos , Infecções Oportunistas Relacionadas com a AIDS/induzido quimicamente , Infecções Oportunistas Relacionadas com a AIDS/patologia , Intervalos de Confiança , DNA Mitocondrial/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/efeitos dos fármacos , Fibras Nervosas/patologia , Medição da Dor , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/patologia , Projetos Piloto
5.
Oncogene ; 26(50): 7103-10, 2007 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-17546056

RESUMO

Transforming growth factor-beta (TGF-beta) signaling members, TGF-beta receptor type II (TBRII), Smad2, Smad4 and Smad adaptor, embryonic liver fodrin (ELF), are prominent tumor suppressors in gastrointestinal cancers. Here, we show that 40% of elf(+/-) mice spontaneously develop hepatocellular cancer (HCC) with markedly increased cyclin D1, cyclin-dependent kinase 4 (Cdk4), c-Myc and MDM2 expression. Reduced ELF but not TBRII, or Smad4 was observed in 8 of 9 human HCCs (P<0.017). ELF and TBRII are also markedly decreased in human HCC cell lines SNU-398 and SNU-475. Restoration of ELF and TBRII in SNU-398 cells markedly decreases cyclin D1 as well as hyperphosphorylated-retinoblastoma (hyperphosphorylated-pRb). Thus, we show that TGF-beta signaling and Smad adaptor ELF suppress human hepatocarcinogenesis, potentially through cyclin D1 deregulation. Loss of ELF could serve as a primary event in progression toward a fully transformed phenotype and could hold promise for new therapeutic approaches in human HCCs.


Assuntos
Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/metabolismo , Proteínas de Transporte/fisiologia , Ciclinas/metabolismo , Neoplasias Hepáticas Experimentais/etiologia , Proteínas dos Microfilamentos/fisiologia , Transdução de Sinais/fisiologia , Espectrina/fisiologia , Fator de Crescimento Transformador beta2/antagonistas & inibidores , Animais , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Ciclina D , Ciclinas/antagonistas & inibidores , Humanos , Neoplasias Hepáticas Experimentais/metabolismo , Camundongos , Camundongos Knockout , Proteínas dos Microfilamentos/deficiência , Proteínas dos Microfilamentos/genética , Fosforilação , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Retinoblastoma/metabolismo , Transdução de Sinais/genética , Espectrina/deficiência , Espectrina/genética , Fator de Crescimento Transformador beta2/metabolismo , Fator de Crescimento Transformador beta2/fisiologia , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/fisiologia
6.
Cancer Res ; 53(16): 3712-8, 1993 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-8393379

RESUMO

The antiproliferative action of 1,25-dihydroxyvitamin D3 in osteosarcoma, breast carcinoma, and colon carcinoma cell lines has been described. In this study, the level of vitamin D receptor was analyzed in a panel of colon adenoma and adenocarcinoma cell lines and the receptor level was correlated with the response to treatment with 1,25-dihydroxyvitamin D3. Ribonuclease protection and ligand-binding assays quantitated the level of vitamin D receptor mRNA expression and the level of functional receptors, respectively. The more well-differentiated cell lines, such as VACO 330, showed higher levels of vitamin D receptor than less-differentiated cell lines, such as SW620. Proliferation assay, clonogenic assay, and growth curve study in HT29 and SW620 cell lines assessed the antiproliferative effect of 1,25-dihydroxyvitamin D3 at concentrations ranging from 10(-11) to 10(-6) M. HT29 showed significant (P < 0.05) growth inhibition at 10(-9) to 10(-6) M concentrations, but growth of SW620 remained unchanged. The amount of vitamin D receptor in 12 malignant colonic tumors was compared with that of adjacent normal tissue, and in 9 cases, the tumor expressed a lower vitamin D receptor level. Our results suggest that the level of vitamin D receptor correlates with the degree of differentiation in human colon cancer cell lines and may serve as a useful biological marker in predicting clinical outcome in patients.


Assuntos
Neoplasias do Colo/química , Receptores de Esteroides/análise , Adenoma/química , Calcitriol/farmacologia , Divisão Celular/efeitos dos fármacos , Neoplasias do Colo/patologia , Humanos , RNA Mensageiro/análise , Receptores de Calcitriol , Células Tumorais Cultivadas , Ensaio Tumoral de Célula-Tronco
7.
Cancer Res ; 54(15): 4057-64, 1994 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-8033137

RESUMO

The use of 1,25-dihydroxyvitamin D3 as an antiproliferative agent in the treatment of cancer is limited by its hypercalcemic effects. Analogues with equivalent or greater antiproliferative activities but smaller hypercalcemic effects have been developed. The antiproliferative effects of 1,25-dihydroxyvitamin D3 and four analogues were studied in HT-29 and SW620 human colon cancer cell lines, moderate and low expressors of the vitamin D receptor, respectively. HT-29 is a primary, moderately differentiated, cell line, while SW620 is metastatic and poorly differentiated. Growth curve studies, proliferation assays, and clonogenic assays were used to assess the antiproliferative effects of 1,25-dihydroxyvitamin D3, 1,25-dihydroxy-16-ene-23-yne-D3, 1,25-dihydroxy-26,27-hexafluoro-16-ene-23-yne-D3, 1,25-dihydroxy-16,23E-diene-26,27-hexafluoro-D3, and 1,25-dihydroxy-16,23Z-diene-26,27-hexafluoro-D3. Growth of HT-29 cells was significantly inhibited by all four analogues at 10(-8) M (P < 0.05). Analogues 1,25-dihydroxy-26,27-hexafluoro-16-ene-23-yne-D3, 1,25-dihydroxy-16,23E-diene-26,27-hexafluoro-D3, and 1,25-dihydroxy-16,23Z-diene-26,27-hexafluoro-D3 were 2 times as potent as analogue 1,25-dihydroxy-16-ene-23-yne-D3 and 1,25-dihydroxyvitamin D3. SW620 cells did not show any growth inhibition with any of the compounds tested. The affinities of the three most potent analogues for the vitamin D receptor were similar to that of 1,25-dihydroxyvitamin D3, while that of analogue 1,25-dihydroxy-16-ene-23-yne-D3 was lower. These results demonstrate that, as in leukemic cells, analogues of 1,25-dihydroxyvitamin D3 are potent antiproliferative agents in colon cancer cells and this activity is most likely mediated through the vitamin D receptor.


Assuntos
Calcitriol/análogos & derivados , Calcitriol/farmacologia , Neoplasias do Colo/patologia , Fosfatase Alcalina/metabolismo , Ligação Competitiva , Calcitriol/metabolismo , Antígeno Carcinoembrionário/metabolismo , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Relação Dose-Resposta a Droga , Humanos , Receptores de Calcitriol/metabolismo , Células Tumorais Cultivadas
8.
Clin Cancer Res ; 4(11): 2869-76, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9829754

RESUMO

The effect of 1,25-dihydroxyvitamin D3 and its synthetic analogue, 1alpha,25-dihydroxy-16-ene-23yne-26,27-hexafluoro-19-n or-cholecalciferol (Ro 25-6760), have been evaluated both in vitro and in vivo in human colorectal cancer cell lines expressing high (HT-29) and low (SW-620) levels of vitamin D receptor. 1,25-Dihydroxyvitamin D3 caused significant dose-dependent growth inhibition of HT-29 cells at concentrations ranging from 10(-11) to 10(-6). The antiproliferative effect of Ro 25-6760 on HT-29 cells was also dose-dependent with cell counts on day 6, ranging from 98% of control at 10(-11) M to 14% of control at 10(-6) M. However, 1,25-dihydroxyvitamin D3 and Ro 25-6760 did not have any growth inhibitory effect on SW-620 at all concentrations. In mice with HT-29 tumor xenografts, administration of vitamin D at 0.1 and 0.2 microg/injection i.p. three times/week did not cause any significant tumor growth delay, whereas synthetic analogue Ro 25-6760, at both concentrations, caused a significant tumor growth inhibition in comparison with the control arm. In 30% of mice treated by R0 25-6760 the tumors disappeared on average after the second injection, and tumor growth did not resume after drug withdrawal. However, both 1,25-dihydroxyvitamin D3 or Ro 25-6760 had no growth inhibitory effect at all applied concentrations in mice with the SW-620 tumor xenografts. The mechanism for this impressive growth inhibition is not yet elucidated and warrants further investigation.


Assuntos
Calcitriol/uso terapêutico , Colecalciferol/análogos & derivados , Neoplasias do Colo/tratamento farmacológico , Animais , Antineoplásicos/uso terapêutico , Calcitriol/análogos & derivados , Cálcio/sangue , Cálcio/metabolismo , Divisão Celular/efeitos dos fármacos , Colecalciferol/uso terapêutico , Neoplasias do Colo/metabolismo , Feminino , Células HT29 , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Células Tumorais Cultivadas
9.
Clin Cancer Res ; 4(7): 1591-5, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9676831

RESUMO

To date, none of the potential biological markers in colorectal cancer attempts to link the epidemiological data with the molecular biology of the disease. In an attempt to link dietary and epidemiological factors and to obtain a better understanding of the molecular biology of colorectal cancer, we measured vitamin D receptor (VDR) expression in 75 human colorectal cancers as a potential predictive marker of the biological behavior of the disease. Our results showed that a high level of VDR expression was associated with a favorable prognosis. The results of the studies reinforce the potential role that VDR may play in the development of the pathogenesis of colorectal cancer. Larger studies looking exclusively at stage I and stage II disease will hopefully lead to the development of a sensitive hormonal marker that can be used to predict the biological behavior of colorectal cancer, identifying at-risk patients in need of adjuvant treatment.


Assuntos
Neoplasias Colorretais/metabolismo , Proteínas de Neoplasias/metabolismo , Receptores de Calcitriol/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Prognóstico , Modelos de Riscos Proporcionais
10.
Cell Prolif ; 28(4): 245-62, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7772641

RESUMO

Calcium supplementation decreases the incidence of colon cancer in animal models and may prevent colon cancer in man. Potential mechanisms include binding of mitogens and direct effects of calcium on colonic epithelial cells. In this study, the effects of extracellular calcium on epithelial cell growth and differentiation were studied in three colon carcinoma and two colonic adenoma cell lines. The characteristics studied included morphology, cell cycle kinetics, [Ca2+]IC (intracellular calcium concentration), proliferation, and expression of differentiation markers such as carcinoembryonic antigen (CEA) and alkaline phosphatase (AP). Sodium butyrate (NaB) and 1,25-dihydroxyvitamin D3 were used as controls in the latter three assays as these two agents are known differentiating agents. Alteration of [Ca+2]EC (extracellular calcium concentration) did not affect carcinoembryonic antigen (CEA) or alkaline phosphatase (AP) expression. NaB enhanced the expression of AP three-fold and CEA five-fold. This effect was augmented by increasing [Ca2+]EC. The exposure of cells to 1,25-(OH)2-Vitamin D3 increased CEA but not AP. [Ca2+]IC increased in response to 1,25-(OH)2-vitamin D3 and NaB but not with variation in [Ca2+]EC. Increased [Ca2+]EC inhibited proliferation of well-differentiated cells, but had no effect on poorly-differentiated cells. Morphological studies showed that extracellular calcium was necessary for normal cell-cell interactions. These studies have demonstrated direct effects of calcium on colonic epithelial cells which may contribute to the protective effects of dietary calcium against colon cancer. Loss of responsiveness to the antiproliferative effects of [Ca2+]EC with de-differentiation suggests that calcium supplementation may be most beneficial prior to the development of neoplastic changes in colonic epithelium.


Assuntos
Cálcio/farmacologia , Divisão Celular/efeitos dos fármacos , Neoplasias do Colo/patologia , Fosfatase Alcalina/biossíntese , Cálcio/análise , Antígeno Carcinoembrionário/análise , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Epitélio/patologia , Humanos , Timidina , Trítio , Células Tumorais Cultivadas
11.
Eur J Cancer ; 33(9): 1413-8, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9337683

RESUMO

Medical consequences of many nuclear accidents on humans are well studied, but the results pertaining to gastric cancer patients who were exposed to radiation as a result of the Chernobyl nuclear accident have not been analysed. In this study, the outcome of the surgical treatment of 68 gastric cancer patients who were exposed to radiation as a result of the Chernobyl nuclear accident was compared with that of 117 consecutive gastric cancer patients from uncontaminated areas of the Ukraine. Patients in the study group was significantly younger than that of the control group. Comparative analysis showed the same frequency of regional metastases (65.7% versus 71.1%, P > 0.05), but a smaller number of distant metastases (23.8% versus 38.1%, P < 0.05) in the study group. 41.2% of patients in the study group underwent total gastrectomy compared to 19.6% of patients in the control group (P = 0.002). Postoperative complications developed in 13.2% of patients in the study group, while postoperative mortality in the study group was 7.3% compared to 1.7% in the control group. A significant decrease in CD16 cells was noted in patients from the study group following the operative procedure. Young age, invasive tumours with smaller number of distant metastases, frequent necessity for total gastrectomy and combined operations with adjacent organs, a higher level of postoperative morbidity and mortality and low levels of natural killer cells (CD16+) with a tendency to decrease after surgery are characteristic of patients with carcinoma of the stomach affected by the Chernobyl accident.


Assuntos
Neoplasias Induzidas por Radiação/etiologia , Liberação Nociva de Radioativos , Neoplasias Gástricas/etiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Gastrectomia/métodos , Humanos , Células Matadoras Naturais/imunologia , Subpopulações de Linfócitos/imunologia , Masculino , Pessoa de Meia-Idade , Neoplasias Induzidas por Radiação/imunologia , Neoplasias Induzidas por Radiação/cirurgia , Neutrófilos/imunologia , Complicações Pós-Operatórias , Distribuição por Sexo , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/cirurgia , Ucrânia
12.
Cancer Lett ; 92(1): 77-82, 1995 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-7757962

RESUMO

We analyzed the antiproliferative effect of 1,25-dihydroxyvitamin D3 and four vitamin D analogs on MCF-7, a human breast cancer cell line known to express the vitamin D receptor. Growth curve studies and [3H]thymidine incorporation assays were used to assess the antiproliferative effect of 1,25-dihydroxyvitamin D3 (vitamin D), Ro 23-7553, Ro 24-5531, Ro 25-5317, and Ro 24-5583. Growth of MCF-7 cells was significantly inhibited by 1,25-dihydroxyvitamin D3 and all four analogs at 10(-8) M (P < 0.05). MCF-7 cells treated with analog had significantly less [3H]thymidine incorporation than cells treated with 1,25-dihydroxyvitamin D3 (P < 0.05). The affinity of the analogs for the vitamin D receptor was similar to that of 1,25-dihydroxyvitamin D3. These results demonstrate that analogs of 1,25-dihydroxyvitamin D3 are potent antiproliferative agents on human breast cancer cells and that this activity is likely mediated through the vitamin D receptor.


Assuntos
Adenocarcinoma/patologia , Neoplasias da Mama/patologia , Calcitriol/análogos & derivados , Calcitriol/farmacologia , Adenocarcinoma/metabolismo , Ligação Competitiva , Neoplasias da Mama/metabolismo , Calcitriol/metabolismo , Divisão Celular/efeitos dos fármacos , Humanos , Receptores de Calcitriol/metabolismo , Células Tumorais Cultivadas
13.
Int J Oncol ; 16(6): 1249-54, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10812003

RESUMO

In order to substantiate the role of vitamin D applicability for the prevention of colon cancer and its spontaneous metastases, the effect of 1,25-dihydroxyvitamin D3 and its synthetic analogs, 1, 25-dihydroxy-16,23Z-diene-26,27-hexafluoro-D3 (Ro 25-5317) and 1, 25-dihydroxy-16,23E-diene-26,27-hexafluoro-19-nor-D3 (Ro 25-9022), have been evaluated in a 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis model in Sprague-Dawley rats. In animals maintained on 2.75 nmol/kg 1,25-dihydroxyvitamin D3 diet no statistical difference was seen in tumor incidence when compared with control while in animals on 3.0 nmol/kg 1,25-dihydroxyvitamin D3 diet, the incidence of tumors was significantly lower. In animals maintained on 3.0 nmol/kg Ro 25-5317 diet also no statistical difference was seen in tumor incidence compared with control while in animals on 3. 5 nmol/kg Ro 25-5317 diet the incidence of tumors was significantly lower. The incidence of tumors in the group of animals maintained on 3.0 nmol/kg and 3.5 nmol/kg Ro 25-9022 was significantly lower, at 32.1% and 27.6% respectively, compared to control. In the two groups of animals maintained on the 1,25-dihydroxyvitamin D3 diet no significant difference in the incidence of metastasis was seen. In the group of animals maintained on 3.0 nmol/kg Ro 25-5317 diet only regional metastases were seen. However, no metastases developed in the rats on 3.5 nmol/kg Ro 25-5317 diet. After administration of 3.0 nmol/kg Ro 25-9022 diet, metastases developed in a significantly less number of animals while no metastases occurred in the rats maintained on the 3.5 nmol/kg Ro 25-9022 diet. The above studies will provide a scientific basis for the progression into further clinical trials in the treatment, and/or chemoprevention of human colorectal cancer.


Assuntos
Calcitriol/uso terapêutico , Agonistas dos Canais de Cálcio/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , 1,2-Dimetilidrazina , Animais , Calcitriol/análogos & derivados , Cálcio/sangue , Carcinógenos , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/prevenção & controle , Humanos , Ratos , Ratos Sprague-Dawley
14.
Int J Oncol ; 14(5): 979-85, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10200351

RESUMO

Our previously performed experiments clearly showed a significant VDR-mediated growth inhibitory effect of 1,25-dihydroxyvitamin D3 and its synthetic analogs in a variety of human cancer cells including human colon and breast cancer, soft tissue sarcoma, and malignant melanoma cell lines. The mechanisms by which 1, 25-dihydroxyvitamin D3 and its synthetic analogs growth inhibit human cancer cells is poorly elucidated. The exposure of human colon cancer cells HT-29 to 1,25-dihydroxyvitamin D3 or its analog, 1alpha, 25-dihydroxy-16-ene-23yne-26,27-hexafluoro-19-nor-choleca lci ferol (Ro 25-6760), at the 10(-6) M concentration resulted in significant growth inhibition with induction of the apoptotic process after three days of treatment detected by TUNEL assay and agarose gel electrophoresis of DNA. As a logical link with DNA fragmentation analyses and TUNEL assay, cleavage of the 116 kDa PARP protein was accompanied by the appearance of a characteristic 85 kDa fragment of PARP in a population of floating cells after both treatments. The results of cell cycle analysis showed a G0/G1 phase block after three days of administration of either compound when compared with untreated cells. On day 4, G0/G1 cell cycle arrest remained on the same level in comparison with control. Paralleling the G0/G1 phase block, was a notable decrease in the number of cells in the S phase which also became significant after three days of treatment. The results of these experiments show that the newly developed 19-nor synthetic vitamin D3 analog, Ro 25-6760, as well as 1, 25-dihydroxyvitamin D3, induced the expression of p21waf1, resulted in a significant G1/G0 cell cycle arrest leading to impressive growth inhibition and induction of apoptosis associated with proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) showing a possible involvement of apoptosis-specific activation of the ICE/CED-3 proteolitic pathway.


Assuntos
Antineoplásicos/farmacologia , Apoptose , Colecalciferol/análogos & derivados , Neoplasias do Colo/patologia , Calcitriol/farmacologia , Divisão Celular/efeitos dos fármacos , Colecalciferol/farmacologia , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/metabolismo , Fase G1/efeitos dos fármacos , Células HT29 , Humanos , Peptídeo Hidrolases/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Fase de Repouso do Ciclo Celular/efeitos dos fármacos , Células Tumorais Cultivadas , Regulação para Cima
15.
J Steroid Biochem Mol Biol ; 54(3-4): 147-53, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7662588

RESUMO

1,25(OH)2-Vitamin D3 inhibits breast cancer cell proliferation through interaction with the vitamin D receptor (VDR). Regulation of VDR is under the influence of several factors which include the functional ligand for this receptor (1,25(OH)2-vitamin D3) as well as heterologous steroid hormones. We evaluated the nature of homologous regulation in T-47D human breast cancer cells with a radiolabelled ligand binding assay and a ribonuclease protection assay for VDR. Significant VDR up-regulation, as measured by hormone binding assays, occurred with pre-incubations with 10(-9)M through 10(-6)M 1,25(OH)2-vitamin D3 (P < 0.05). A 7-fold VDR up-regulation with 10(-8)M 1,25(OH)2-vitamin D3 occurred at 4 h treatment and was not associated with an increase in VDR mRNA expression on ribonuclease protection assay. This supports the hypothesis that up-regulation of VDR is probably the result of ligand-induced stabilization of pre-existing receptor. All-trans-retinoic acid, the progesterone analog R-5020, and prednisone were found to induce heterologous up-regulation of the VDR. We then determined with ligand binding assays whether 1,25(OH)2-vitamin D3 could influence receptor levels for another hormone in a manner analogous to the heterologous regulation of VDR. Regulation of estrogen receptor (ER) by 1,25(OH)2-vitamin D3 was studied in T-47D and MDA-MB-231 breast cancer cells. Incubation of T-47D cells, which are ER (+), with 10(-8)M 1,25(OH)2-vitamin D3 did not result in up-regulation of ER. Yet estrogen binding was significantly up-regulated in a cell line that is ER(-), MDA-MB-231. The increased estrogen binding was associated with a shift in binding affinity and ribonuclease protection assay showed absence of ER mRNA in these cells, suggesting an up-regulation of estrogen binding proteins and not of the ER itself.


Assuntos
Neoplasias da Mama/metabolismo , Calcitriol/farmacologia , Receptores de Calcitriol/metabolismo , Receptores de Estrogênio/metabolismo , Feminino , Humanos , Ensaio Radioligante , Esteroides/farmacologia , Células Tumorais Cultivadas
16.
Arch Surg ; 135(6): 723-8, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10843374

RESUMO

Laparoscopic Nissen fundoplication is now widely used in the surgical management of gastroesophageal reflux disease. However, it is a complex operation that requires advanced laparoscopic skills. The learning curve is steep, and complications are directly related to the surgeon's experience level. Both experimental and clinical data demonstrate a decline in complications with increasing experience. We divided this complex procedure into logical and orderly components, to facilitate the learning process. We believe that this approach will not only reduce complications by highlighting potential problems at each stage but also make it easier to teach others.


Assuntos
Fundoplicatura , Laparoscopia , Fundoplicatura/métodos , Refluxo Gastroesofágico/cirurgia , Humanos , Laparoscopia/métodos , Técnicas de Sutura
17.
Cancer Chemother Pharmacol ; 34(3): 257-60, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8004760

RESUMO

The purpose of this study was to assess the efficacy of verapamil (20 microM) and hyperthermia (42 degrees C) as modifiers of mitomycin C (MMC), used at different concentrations, in inhibiting the growth of human gastric adenocarcinoma (AGS) cells. Combined verapamil and hyperthermia treatment resulted in a significant decrease in cell count by 72.2% as compared with the control value. Verapamil drastically enhanced the growth-inhibitory activity of MMC at high concentration against AGS cells by 67.5% and had no effect at intermediate and low concentrations. Hyperthermia did not enhance the effect of MMC on AGS cells. The modalities analyzed in this study require further investigation and may have potential for in vivo studies on gastric cancer therapy in the near future.


Assuntos
Adenocarcinoma/terapia , Hipertermia Induzida , Mitomicina/uso terapêutico , Neoplasias Gástricas/terapia , Verapamil/uso terapêutico , Adenocarcinoma/tratamento farmacológico , Terapia Combinada , Quimioterapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Gástricas/tratamento farmacológico , Células Tumorais Cultivadas
18.
Surg Oncol ; 3(5): 295-304, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7889223

RESUMO

Ectopic breast tissue includes both supernumerary and aberrant breast tissue. The incidence of supernumerary tissue has been reported as high as 6% depending on the ethnic group studied. The incidence of aberrant breast tissue remains unknown. The development of malignancy within these anomalies is rare. In the following paper, the case report of a patient with an ectopic breast cancer and a second primary cancer of the left anatomic breast is described. A review of the world literature on ectopic breast cancer follows. Specific characteristics of ectopic breast cancer are defined and recommendations for management are made.


Assuntos
Neoplasias da Mama , Mama , Coristoma , Neoplasias da Mama/patologia , Coristoma/patologia , Feminino , Humanos , Pessoa de Meia-Idade
19.
Surg Oncol ; 3(4): 243-8, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7834115

RESUMO

Malignant lymphomas comprise 1-4% of the malignant neoplasms of the gastrointestinal tract, but appendiceal lymphomas are exceedingly rare. Herein is presented a case of a well differentiated lymphocytic lymphoma of the appendix found incidentally at hernia repair. Forty-six cases of appendiceal lymphoma have been reported since 1898 with a mean patient age of 25.7 years. Thirty-one patients presented with right lower quadrant pain, and a mass was an incidental finding in five. Of the 46 cases, follow-up was possible in 28. There were four deaths within 30 days of the operation and five deaths within 1 year. Although extensive follow-up is limited, there have been only two reported deaths secondary to primary appendiceal lymphoma since 1945 and these two cases are discussed in detail. Based on this extensive review, appropriate recommendations are made.


Assuntos
Neoplasias do Apêndice , Leucemia Linfocítica Crônica de Células B , Idoso , Neoplasias do Apêndice/complicações , Neoplasias do Apêndice/diagnóstico , Neoplasias do Apêndice/cirurgia , Diagnóstico Diferencial , Neoplasias Gastrointestinais/diagnóstico , Hérnia Inguinal/complicações , Hérnia Inguinal/cirurgia , Humanos , Leucemia Linfocítica Crônica de Células B/complicações , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/cirurgia , Masculino
20.
Surg Oncol ; 3(5): 287-94, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7889222

RESUMO

The purpose of this study was to assess the efficacy of verapamil (20 microM) and hyperthermia (42 degrees C) as modifiers of 5-fluorouracil (5-FU), used at different concentrations, in inhibiting the growth of gastric adenocarcinoma cells. Combined verapamil and hyperthermia treatment showed a significant decrease in cell count when compared to control (72.2%), hyperthermia alone (68.4%), or verapamil alone (65%). At a high concentration of 5-FU (50 micrograms/ml), verapamil and hyperthermia had an additive growth inhibitory effect over a 4-day period when compared to control. A combination of 5-FU at low concentration (0.5 microgram/ml) with verapamil significantly suppressed growth by 31.2% in comparison to control--with this effect being independent of the duration of treatment. The modalities analysed in this study require further investigation and have potential for clinical applicability to gastric cancer therapy in the future.


Assuntos
Adenocarcinoma/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Hipertermia Induzida , Neoplasias Gástricas/terapia , Adenocarcinoma/patologia , Contagem de Células , Terapia Combinada , Feminino , Fluoruracila/administração & dosagem , Humanos , Pessoa de Meia-Idade , Neoplasias Gástricas/patologia , Células Tumorais Cultivadas , Verapamil/administração & dosagem
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