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1.
São Paulo; s.n; s.n; 2021. 275 p. tab, graf.
Thesis in Portuguese | LILACS | ID: biblio-1379262

ABSTRACT

A alta incidência, prevalência e mortalidade do câncer de pulmão demonstram a necessidade de se identificar alterações moleculares envolvidas na carcinogênese pulmonar. Nesse contexto, a reprogramação do metabolismo energético é uma marca emergente do câncer. Há evidências de que benzo[a]pireno (B[a]P), um conhecido carcinógeno humano, induz alterações metabólicas via modificação da função mitocondrial tanto in vitro quanto in vivo. Uma vez que as alterações metabólicas não são somente o resultado da transformação celular, mas podem também ter papel na etiologia do câncer ao modular o epigenoma e a expressão de genes, intervir no metabolismo de células em processo de transformação pode contribuir para desvendar mecanismos de carcinogênese e revelar alvos para quimioprevenção. A fim de investigar a relação entre alterações no metabolismo celular, marcas epigenéticas e transformação celular, implementamos um modelo de tumorigênese (avaliada pela formação de colônias em soft-agar) induzida por B[a]P em células epiteliais bronquiais humanas imortalizadas (linhagem BEAS-2B) crescidas em monocamada (2D). O modelo possibilitou a observação de alterações precoces do metabolismo celular. Levando em consideração que o nucleotídeo NAD+ regula as atividades de diversas vias moleculares importantes para a sobrevivência, diferenciação, crescimento e morte celular, e que suas concentrações foram rapidamente diminuídas após exposição a B[a]P, decidimos suplementar as células BEAS-2B com nicotinamida ribosídeo (NR), um precursor intracelular de NAD+, concomitantemente à exposição a B[a]P. NR em baixa concentração no meio de cultura (1 µM) induziu estresse energético em células BEAS-2B expostas a B[a]P (1 µM) ao longo do período de uma semana de co-incubação, aumentando seletivamente a taxa de apoptose dessas células. Protegeu contra a transformação celular induzida por B[a]P e impediu completamente a formação espontânea de colônias das células controle em soft-agar. Usamos uma abordagem metabolômica direcionada a alvos específicos ("targeted metabolomics") desenvolvida no grupo para quantificar metabólitos conhecidamente alterados no câncer. Os dados indicam que NR diminui o metabolismo de glutamina nas células expostas a B[a]P, o que ocorre em paralelo com a diminuição das concentrações de citrato e aspartato, aumento da razão malato/aspartato, diminuição das razões ATP/AMP e ATP/ADP e aumento das concentrações de adenosina. As alterações se enquadram na hipótese de inibição do shuttle malato-aspartato, cuja atividade é necessária para a sobrevivência de células que sofrem o efeito Warburg (alta dependência de NADH citosólico para geração de ATP). NR adicionalmente protegeu as células contra o estresse redox, a hipermetilação do DNA e o aumento da atividade de sirtuína 1 (SIRT1) induzidos por B[a]P, além de aumentar a expressão de genes supressores tumorais (E-caderina, PTEN, semaforina 3F, p16(ink4a)) que podem ser reprimidos por CtBP (proteína ligante de NADH que atua como sensor redox e traduz a condição metabólica da célula para o controle da expressão gênica). Foi ainda observada maior atividade de PARP1 nas células expostas a B[a]P+NR em comparação aos demais grupos. Os resultados obtidos mostram que NR se contrapõe a ou exacerba alterações bioquímicas induzidas por B[a]P, diminuindo a chance de transformação carcinogênica das células BEAS-2B. Estudos em modelos mais complexos, como micro tecidos in vitro, são necessários para a confirmação do efeito quimiopreventivo da NR e alterações bioquímicas subjacentes


Tese de DoutoradoDOIhttps://doi.org/10.11606/T.9.2021.tde-05082021-095853DocumentoTese de DoutoradoAutorCordeiro, Everson Willian Fialho (Catálogo USP)Nome completoEverson Willian Fialho CordeiroE-mailE-mailUnidade da USPFaculdade de Ciências FarmacêuticasÁrea do ConhecimentoToxicologiaData de Defesa2021-04-08ImprentaSão Paulo, 2021OrientadorLoureiro, Ana Paula de Melo (Catálogo USP) Banca examinadoraLoureiro, Ana Paula de Melo (Presidente) Àvila, Daiana Silva de Meotti, Flavia Carla Silva, Eloiza Helena Tajara da Título em portuguêsModulação da concentração intracelular de NAD+ e seu efeito na tumorigênese induzida por benzo[a]pireno em células bronquiais epiteliais humanasPalavras-chave em portuguêsBenzo[a]pireno Câncer de pulmão Metabolismo energético Nicotinamida ribosídeo Resumo em portuguêsA alta incidência, prevalência e mortalidade do câncer de pulmão demonstram a necessidade de se identificar alterações moleculares envolvidas na carcinogênese pulmonar. Nesse contexto, a reprogramação do metabolismo energético é uma marca emergente do câncer. Há evidências de que benzo[a]pireno (B[a]P), um conhecido carcinógeno humano, induz alterações metabólicas via modificação da função mitocondrial tanto in vitro quanto in vivo. Uma vez que as alterações metabólicas não são somente o resultado da transformação celular, mas podem também ter papel na etiologia do câncer ao modular o epigenoma e a expressão de genes, intervir no metabolismo de células em processo de transformação pode contribuir para desvendar mecanismos de carcinogênese e revelar alvos para quimioprevenção. A fim de investigar a relação entre alterações no metabolismo celular, marcas epigenéticas e transformação celular, implementamos um modelo de tumorigênese (avaliada pela formação de colônias em soft-agar) induzida por B[a]P em células epiteliais bronquiais humanas imortalizadas (linhagem BEAS-2B) crescidas em monocamada (2D). O modelo possibilitou a observação de alterações precoces do metabolismo celular. Levando em consideração que o nucleotídeo NAD+ regula as atividades de diversas vias moleculares importantes para a sobrevivência, diferenciação, crescimento e morte celular, e que suas concentrações foram rapidamente diminuídas após exposição a B[a]P, decidimos suplementar as células BEAS-2B com nicotinamida ribosídeo (NR), um precursor intracelular de NAD+, concomitantemente à exposição a B[a]P. NR em baixa concentração no meio de cultura (1 µM) induziu estresse energético em células BEAS-2B expostas a B[a]P (1 µM) ao longo do período de uma semana de co-incubação, aumentando seletivamente a taxa de apoptose dessas células. Protegeu contra a transformação celular induzida por B[a]P e impediu completamente a formação espontânea de colônias das células controle em soft-agar. Usamos uma abordagem metabolômica direcionada a alvos específicos ("targeted metabolomics") desenvolvida no grupo para quantificar metabólitos conhecidamente alterados no câncer. Os dados indicam que NR diminui o metabolismo de glutamina nas células expostas a B[a]P, o que ocorre em paralelo com a diminuição das concentrações de citrato e aspartato, aumento da razão malato/aspartato, diminuição das razões ATP/AMP e ATP/ADP e aumento das concentrações de adenosina. As alterações se enquadram na hipótese de inibição do shuttle malato-aspartato, cuja atividade é necessária para a sobrevivência de células que sofrem o efeito Warburg (alta dependência de NADH citosólico para geração de ATP). NR adicionalmente protegeu as células contra o estresse redox, a hipermetilação do DNA e o aumento da atividade de sirtuína 1 (SIRT1) induzidos por B[a]P, além de aumentar a expressão de genes supressores tumorais (E-caderina, PTEN, semaforina 3F, p16(ink4a)) que podem ser reprimidos por CtBP (proteína ligante de NADH que atua como sensor redox e traduz a condição metabólica da célula para o controle da expressão gênica). Foi ainda observada maior atividade de PARP1 nas células expostas a B[a]P+NR em comparação aos demais grupos. Os resultados obtidos mostram que NR se contrapõe a ou exacerba alterações bioquímicas induzidas por B[a]P, diminuindo a chance de transformação carcinogênica das células BEAS-2B. Estudos em modelos mais complexos, como micro tecidos in vitro, são necessários para a confirmação do efeito quimiopreventivo da NR e alterações bioquímicas subjacentes.Título em inglêsModulation of intracellular concentration of NAD+ and its effect on benzo[a]pyrene-induced tumorigenesis in human epithelial bronchial cellsPalavras-chave em inglêsBenzo[a]pyrene Energetic metabolism Lung cancer Nicotinamide riboside Resumo em inglêsThe high incidence, prevalence and mortality of lung cancer demonstrates the need to identify molecular changes involved in lung carcinogenesis. In this context, the reprogramming of energy metabolism is an emerging brand of cancer. There is evidence that benzo[a]pyrene (B[a]P), a known human carcinogen, induces metabolic changes via modification of mitochondrial function both in vitro and in vivo. Since metabolic changes are not only the result of cell transformation, but can also play a role in the etiology of cancer by modulating the epigenome and gene expression, intervening in the metabolism of cells in the process of transformation can contribute to unravel mechanisms of carcinogenesis and reveal targets for chemoprevention. In order to investigate the relationship between changes in cell metabolism, epigenetic marks and cell transformation, we implemented a model of tumorigenesis (assessed by the formation of colonies on soft-agar) induced by B[a]P in immortalized human bronchial epithelial cells (BEAS-2B cell line human) grown in monolayer (2D). The model enabled the observation of early changes in cell metabolism. Taking into account that the NAD+ nucleotide regulates the activities of several molecular pathways important for cell survival, differentiation, growth and death, and that their concentrations were rapidly decreased after exposure to B[a]P, we decided to supplement the BEAS-2B cells with nicotinamide riboside (NR), an intracellular precursor of NAD+, concomitantly with exposure to B[a]P. NR in low concentration in the culture medium (1 µM) induced energy stress in BEAS-2B cells exposed to B[a]P (1 µM) over the period of a week of co-incubation, selectively increasing the apoptosis rate of these cells. It protected against cell transformation induced by B[a]P and completely prevented the spontaneous formation of control cell colonies on soft-agar. We use a targeted metabolomics approach developed in the group to quantify metabolites known to be altered in cancer. The data indicate that NR decreases the glutamine metabolism in cells exposed to B[a]P, which occurs in parallel with the decrease in citrate and aspartate concentrations, increased malate/aspartate ratio, decreased ATP/AMP and ATP/ADP ratios and increased adenosine concentrations. The changes fit the hypothesis of inhibition of the malate-aspartate shuttle, whose activity is necessary for the survival of cells that suffer the Warburg effect (high dependence on cytosolic NADH for ATP generation). NR additionally protected cells against redox stress, DNA hypermethylation and increased B[a]P-induced sirtuin 1 (SIRT1) activity, in addition to increasing the expression of tumor suppressor genes (E-cadherin, PTEN, semaphorin 3F, p16 (ink4a)) that can be suppressed by CtBP (NADH-binding protein that acts as a redox sensor and translates the cell's metabolic condition to control gene expression). Higher PARP1 activity was also observed in cells exposed to B[a]P+NR compared to the other groups. The results obtained show that NR is opposed to or exacerbates biochemical changes induced by B[a]P, reducing the chance of carcinogenic transformation of BEAS-2B cells. Studies on more complex models, such as micro tissues in vitro, are necessary to confirm the chemopreventive effect of NR and underlying biochemical changes


Subject(s)
Niacinamide/adverse effects , Carcinogenesis/drug effects , Lung Neoplasms/pathology , In Vitro Techniques/methods , DNA , Chemoprevention/classification , Energy Metabolism , Epithelial Cells/classification
2.
Clinics ; 76: e2498, 2021. tab, graf
Article in English | LILACS | ID: biblio-1153964

ABSTRACT

OBJECTIVES: To evaluate the efficacy and safety of sorafenib in elderly patients with advanced hepatocellular carcinoma (HCC). METHODS: We analyzed data from a cohort of patients with advanced HCC treated using systemic treatment according to the local institutional protocol. Patients were divided into two groups, Group A, individuals <70 years of age, and Group B, individuals 70 years of age or older at the time of treatment initiation. Efficacy, measured based on overall survival (OS) and time to treatment failure (TTF), and toxicity were compared between groups. RESULTS: A total of 238 patients with advanced HCC who received sorafenib between 2007 and 2018 were evaluated. The median age for Group A was 59.1 years and that for Group B 73.6 years. The major prognostic characteristics were balanced between the groups. There were no significant differences in OS between Group A (8.0 months, 95%CI 6.34-9.3) and Group B (9.0 months, 95%CI 5.38-12.62), p=0.433, or in TTF between Group A (3.0 months, 95%CI 2.39-3.60) and Group B (3.0 months, 95%CI 1.68-4.32), p=0.936. There were no significant differences between Groups A and B with respect to the incidence of adverse events or treatment discontinuation because of toxicity. CONCLUSION: Efficacy and safety of sorafenib did not differ significantly between younger and older patients with HCC. Our data suggest that age alone should not restrict clinical decision-making for patients with advanced HCC.


Subject(s)
Humans , Middle Aged , Aged , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Antineoplastic Agents/adverse effects , Phenylurea Compounds/adverse effects , Prognosis , Niacinamide/adverse effects , Sorafenib/adverse effects
4.
Ann. hepatol ; 16(2): 263-268, Mar.-Apr. 2017. tab, graf
Article in English | LILACS | ID: biblio-887231

ABSTRACT

ABSTRACT Background and Aims. The presence of dermatologic reaction as an adverse event to sorafenib treatment in patients with unresectable hepatocellular carcinoma has been indicated as a prognostic factor for survival in a recent prospective analysis. To date, this is the only clinical predictor of treatment response, which can be evaluated earlier in the treatment and, therefore, contribute to a better and more individualized patient management. Material and methods. This retrospective study included 127 patients treated with sorafenib under real-life practice conditions in two hepatology reference centers in Brazil. Demographic data, disease/medical history and time of sorafenib administration as well as adverse events related to the medication were recorded in a database. Results. Cirrhosis was present in 94% of patients, 85.6% were Child-Pugh A, 80.3%BCLC-C, 81% had vascular invasion and/or extrahepatic spread and 95% had a performance status 0 to 1.The median duration of treatment was 10.1 months (range: 0.1-47 months).The most common adverse event within the first 60 days of treatment were diarrhea (62.2%) and dermatological reaction (42%).The median overall survival for the cohort was 20 months, and it was higher for patients who developed dermatological reactions within the first 60 days compared to those who did not present this adverse event. Conclusion. This retrospective analysis showed the use of sorafenib in patients selected according to BCLC staging, and it is the first external validation of early dermatologic adverse events as a predictor of overall survival in patients with advanced hepatocellular carcinoma.


Subject(s)
Humans , Phenylurea Compounds/adverse effects , Niacinamide/analogs & derivatives , Drug Eruptions/etiology , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Antineoplastic Agents/adverse effects , Time Factors , Proportional Hazards Models , Retrospective Studies , Risk Factors , Treatment Outcome , Niacinamide/adverse effects , Drug Eruptions/diagnosis , Drug Eruptions/mortality , Carcinoma, Hepatocellular/mortality , Carcinoma, Hepatocellular/pathology , Kaplan-Meier Estimate , Sorafenib , Liver Neoplasms/mortality , Liver Neoplasms/pathology , Neoplasm Staging
5.
Ann. hepatol ; 16(2): 247-254, Mar.-Apr. 2017. tab, graf
Article in English | LILACS | ID: biblio-887229

ABSTRACT

ABSTRACT Background & Aim. Transarterial chemoembolization (TACE) or sorafenib is recommended for hepatocellular carcinoma BCLC stages B and C respectively. We studied the role of combination of TACE and sorafenib in BCLC stages B/C. Material and methods. We undertook an observational study on a cohort of cirrhotics with HCC from August 2010 through October 2014. Patients in BCLC stages B/C who had received TACE and/or sorafenib were included. mRECIST criteria were used to assess tumor response. The primary end point was overall survival. Results. Out of 124 patients, 47.6% were in BCLC-B and 52.4% in BCLCC. Baseline characteristics were comparable. The predominant etiology was cryptogenic (37.2% and 38.5%, p = NS). 49.1% in BCLC-B and 56.9% in BCLC-C had received TACE+sorafenib. In BCLC-B, the overall survival improved from 9 months (95% CI 6.3-11.7) using TACE only to 16 months (95% CI 12.9-19.1) using TACE+sorafenib (p < 0.05). In BCLC-C, addition of TACE to sorafenib improved the overall survival from 4 months (95%CI 3-5) to 9 months (95%CI 6.8-11.2) (p < 0.0001). As per mRECIST criteria, patients on TACE+sorafenib had reduced progressive disease (37.8% vs. 83.3%), improved partial response (43.2% vs. 3.3%) and one had complete response compared to those on sorafenib alone (p < 0.0001) in BCLC-C but not in BCLC-B group. Hand foot syndrome was noted in 27.7% patients on sorafenib and post TACE syndrome in 80.2% patients, but both were reversible. No major adverse events were noted. Conclusion. TACE+sorafenib was more effective than TACE or sorafenib alone in HCC BCLC stages B or C with a significant survival benefit and improved tumour regression especially in BCLC-C patients.


Subject(s)
Humans , Phenylurea Compounds/therapeutic use , Niacinamide/analogs & derivatives , Carcinoma, Hepatocellular/therapy , Protein Kinase Inhibitors/therapeutic use , Liver Neoplasms/therapy , Antineoplastic Agents/therapeutic use , Phenylurea Compounds/adverse effects , Time Factors , Treatment Outcome , Chemoembolization, Therapeutic/adverse effects , Chemoembolization, Therapeutic/mortality , Niacinamide/adverse effects , Niacinamide/therapeutic use , Carcinoma, Hepatocellular/etiology , Carcinoma, Hepatocellular/mortality , Carcinoma, Hepatocellular/pathology , Protein Kinase Inhibitors/adverse effects , Tumor Burden , Kaplan-Meier Estimate , Liver Neoplasms/etiology , Liver Neoplasms/mortality , Neoplasm Staging , Antineoplastic Agents/adverse effects
6.
Arq. bras. endocrinol. metab ; 58(1): 37-41, 02/2014. tab, graf
Article in English | LILACS | ID: lil-705238

ABSTRACT

Objective: To investigate the efficacy of sorafenib in progressive radioiodine resistant metastatic thyroid carcinoma.Subjects and methods: Off-label observational study. Sorafenib 400 mg twice daily was evaluated. Therapy duration was 12 ± 3 months (range 6-16 months).Results: Eight patients were included (seven papillary, one insular variant). The eight patients meeting study criteria received sorafenib 400 mg orally twice a day until disease progression or unacceptable toxicity developed. One patient showed a partial response with tumor regression of -35%, six months after the beginning of the treatment; five patients exhibited stable disease and two patients had progressive disease and died. Thyroglobulin decreased within 4 weeks in all patients by 50% ± 23%.Adverse events: one patient had heart failure, and recovered after sorafenib withdrawal. However, she died five months later of sudden death.Conclusion: These data suggest a possible role for sorafenib in the treatment of progressive metastatic DTC. Adverse event are usually manageable, but severe ones may appear and these patients should be strictly controlled.


Objetivo: Investigar a eficácia do sorafenibe no carcinoma de tireoide metastático progressivo e refratário à iodoterapia.Sujeitos e métodos: Estudo observacional do efeito do sorafenibe off-label administrado 400 mg duas vezes ao dia. A duração da terapia foi de 12 ± 3 meses (variação de 6-16 meses).Resultados: Oito pacientes foram incluídos (sete com variante papilífera e um com variante insular). Os oito pacientes que preencheram os critérios do estudo receberam o sorafenibe 400 mg por via oral duas vezes por dia até progressão da doença ou toxicidade inaceitável. Um paciente apresentou uma resposta parcial com regressão tumoral da lesão alvo de 35% seis meses após o início do tratamento; cinco pacientes apresentaram doença estável e dois pacientes progrediram e morreram. A tireoglobulina diminuiu 50% ± 23% em 4 semanas em todos os pacientes.Eventos adversos: um paciente teve insuficiência cardíaca e morreu por morte súbita cinco meses após a retirada do sorafenibe.Conclusão: Esses dados sugerem um possível papel para sorafenibe para o tratamento do CDT metastático progressivo.


Subject(s)
Aged , Female , Humans , Male , Middle Aged , Antineoplastic Agents/therapeutic use , Carcinoma, Papillary/drug therapy , Carcinoma, Papillary/pathology , Niacinamide/analogs & derivatives , Phenylurea Compounds/therapeutic use , Thyroid Neoplasms/drug therapy , Antineoplastic Agents/adverse effects , Bone Neoplasms/secondary , Compassionate Use Trials , Carcinoma, Papillary/radiotherapy , Carcinoma, Papillary/secondary , Follow-Up Studies , Heart Failure/chemically induced , Iodine Radioisotopes/therapeutic use , Lung Neoplasms/secondary , Niacinamide/adverse effects , Niacinamide/therapeutic use , Phenylurea Compounds/adverse effects , Response Evaluation Criteria in Solid Tumors , Treatment Outcome , Thyroglobulin/blood , Thyroid Neoplasms/pathology , Thyroid Neoplasms/radiotherapy
7.
The Korean Journal of Gastroenterology ; : 47-50, 2014.
Article in English | WPRIM | ID: wpr-87789

ABSTRACT

Hepatocellular carcinoma (HCC) is a critical global health issue and the third most common cause of cancer-related deaths worldwide. The majority of patients who present HCC are already at an advanced stage and their tumors are unresectable. Sorafenib is a multi-kinase inhibitor of the vascular endothelial growth factor pathway and was recently introduced as a therapy for advanced HCC. Furthermore, studies have shown that oral sorafenib has beneficial effects on survival. However, many patients experience diverse side effects, and some of these are severe. Liver abscess development has not been previously documented to be associated with sorafenib administration in HCC. Here, we report the case of a HCC patient that developed a liver abscess while being treated with sorafenib.


Subject(s)
Humans , Male , Middle Aged , Anti-Bacterial Agents/therapeutic use , Antineoplastic Agents/adverse effects , Carcinoma, Hepatocellular/drug therapy , Clostridium/isolation & purification , Clostridium Infections/drug therapy , Liver Abscess/etiology , Liver Neoplasms/drug therapy , Niacinamide/adverse effects , Phenylurea Compounds/adverse effects , Tomography, X-Ray Computed
8.
Gut and Liver ; : 696-703, 2013.
Article in English | WPRIM | ID: wpr-209556

ABSTRACT

BACKGROUND/AIMS: We investigated the effects of sorafenib monotherapy on advanced hepatocellular carcinoma (HCC) and portal vein tumor thrombosis (PVTT) in a clinical setting. METHODS: In total, 143 consecutive patients with unresectable HCC were treated with sorafenib. Among these patients, 30 patients with advanced HCC and PVTT (Vp3 or 4) were treated with sorafenib monotherapy. RESULTS: All patients had a performance status of 1 to 2 (Eastern Cooperative Oncology Group 1/2, 20/10) and Child-Pugh class A or B (A/B, 17/13). Eleven patients had modified Union for International Cancer Control stage IVA tumors, whereas 19 had stage IVB tumors. All patients had PVTT (Vp3, 6; Vp4, 24). Following sorafenib monotherapy, three patients (10.0%) had a partial response with PVTT revascularization, and nine (30.0%) had stable disease, with a disease control rate of 33.3%. The median overall survival was 3.1 months (95% confidence interval [CI], 2.70 to 3.50), and the median progression-free survival was 2.0 months (95% CI, 1.96 to 2.05). Fatigue and hand-foot skin reactions were the most troublesome side effects. CONCLUSIONS: A limited proportion of patients with advanced HCC and PVTT exhibited a remarkable outcome after sorafenib monotherapy, although the treatment results in this type of patient is extremely poor. Further studies to predict good responders to personalized therapy are warranted.


Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Anorexia/chemically induced , Antineoplastic Agents/adverse effects , Carcinoma, Hepatocellular/drug therapy , Diarrhea/chemically induced , Disease-Free Survival , Fatigue/chemically induced , Hand-Foot Syndrome/etiology , Kaplan-Meier Estimate , Liver Neoplasms/drug therapy , Magnetic Resonance Imaging , Nausea/chemically induced , Neoplasm Invasiveness , Niacinamide/adverse effects , Phenylurea Compounds/adverse effects , Portal Vein/pathology , Proportional Hazards Models , Tomography, Spiral Computed , Venous Thrombosis/drug therapy
9.
Experimental & Molecular Medicine ; : 782-792, 2009.
Article in English | WPRIM | ID: wpr-193561

ABSTRACT

Intraportal islet transplantation (IPIT) may potentially cure Type 1 diabetes mellitus; however, graft failure in the early post-transplantation period presents a major obstacle. In this study, we tested the ability of nicotinamide to prevent early islet destruction in a syngeneic mouse model. Mice (C57BL/6) with chemically-induced diabetes received intraportal transplants of syngeneic islet tissue in various doses. Islets were cultured for 24 h in medium with or without 10 mM nicotinamide supplementation. Following IPIT, islet function was confirmed by an intraperitoneal glucose tolerance test (IPGTT) and hepatectomy. The effects of nicotinamide were evaluated by blood glucose concentration, serum monocyte chemoattractant protein-1 (MCP-1) concentration, and immunohistology at 3 h and 24 h after IPIT. Among the various islet doses, an infusion of 300 syngeneic islets treated with nicotinamide exhibited the greatest differences in glucose tolerance between recipients of treated and untreated (i.e., control) islets. One day after 300 islet equivalent (IEQ) transplantation, islets treated with nicotinamide were better granulated than the untreated islets (P = 0.01), and the recipients displayed a slight decrease in serum MCP-1 concentration, as compared to controls. After 15 days, recipients of nicotinamide-pretreated islets showed higher levels of graft function (as measured by IPGTT) than controls. The pretreatment also prolonged graft survival (> 100 days) and function; these were confirmed by partial hepatectomy, which led to the recurrence of diabetes. Pretreatment of islet grafts with nicotinamide may prevent their deterioration on the early period following IPIT in a syngeneic mouse model.


Subject(s)
Animals , Mice , Blood Glucose/metabolism , Chemokine CCL2/blood , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Type 1/blood , Glucose Tolerance Test , Graft Rejection , Graft Survival/drug effects , Insulin-Secreting Cells/metabolism , Islets of Langerhans Transplantation , Niacinamide/adverse effects , Time Factors , Transplantation, Homologous , Vitamin B Complex/adverse effects
10.
Egyptian Journal of Physiological Sciences. 1995; 19 (1-2): 77-95
in English | IMEMR | ID: emr-107950

ABSTRACT

Pea seeds were soaked in different solutions of uniconazole or nicotinamide for 24 hours. The effects of such treatment on germination of these seeds and some growth parameters of the given plants concomitant with the changes in the hormonal contents and activities of IAA oxidase, amylase and proteinase were investigated. Uniconazole was found to retard the rate germination of the seeds and retard the elongation of stems accompanied with increases in the number of their lateral branches and stem thickness, but decreases the number of leaves and their area per plant leading to reduction in both fresh and dry weights of shoots and roots. These aspects were accompanied with clear reduction in the contents and levels of cytokinins, ABA and activity of IAA oxidase. In the same time the activities of amylase and proteinase were reduced. All these physiological phenomena were proportional to the concentration of uniconazole. On the other hand, nicotinamide caused diverse effects on the previously mentioned physiological phenomena as compared with those caused by the corresponding concentrations of uniconazole. This was accompanied by regular picture of hormone contents and complete disappearance of ABA, and these effects were proportional to nicotinamide concentrations. In all cases the endogenous hormonal picture coordinated with the different physiological changes studied


Subject(s)
Niacinamide/adverse effects , Triazoles , Growth , Fetal Growth Retardation , Hormones , Germination/drug effects
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