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1.
World J Surg ; 42(6): 1860-1866, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29302723

RESUMO

BACKGROUND: Recent developments in perioperative pathophysiology and care have documented evidence-based, multimodal rehabilitation (fast-track) to hasten recovery and decrease morbidity and hospital stay in several major surgical procedures. The aim of this study was to investigate the effect over time of a modified previously published fast-track programme in unselected patients undergoing open or laparoscopic liver resection. METHODS: A prospective study includes the first 121 consecutive patients following an updated fast-track programme for liver resection. High-dose methylprednisolone was given to all patients before surgery, catheters and drains were systematically removed early, and patients were mobilized and started eating and drinking from the day of surgery. An opioid-sparing multimodal pain treatment was given for the first week. The discharge criteria were (1) pain sufficiently controlled by oral analgesics only; (2) patient comfortable with discharge; (3) no untreated complications. RESULTS: The median length of stay (LOS) for all patients was 4 days, with 2 days after laparoscopic vs. 4 days for open resections. The median LOS after major hepatectomies (≥3 segments) was 5 days. The readmission rate was 6% and the 30-day mortality zero. The LOS decreased compared to our first-generation fast-track programme with LOS 5 days. CONCLUSIONS: Fast-track principles for perioperative care and early discharge are safe even after major liver resection. The introduction of high-dose steroids preoperatively might have facilitated a shorter LOS. Routine discharge on POD 1 or 2 after laparoscopic resection and on POD 4 after open liver resection has proven to be feasible.


Assuntos
Hepatectomia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Laparoscopia , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Assistência Perioperatória , Estudos Prospectivos
2.
Photochem Photobiol Sci ; 16(3): 411-415, 2017 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-27910985

RESUMO

Acheson et al. (1960) observed an inverse relationship between sunlight exposure and the incidence of Multiple Sclerosis (MS). This led to the suggestion that increased levels of vitamin D caused by sunlight in some way suppresses MS. Further, super physiological doses of the metabolically active metabolite of vitamin D, i.e. 1α,25 dihydroxy vitamin D suppresses the animal model of MS i.e. experimental autoimmune encephalomyelitis (EAE). However, this response was accompanied by hypercalcemia. Hypercalcemia itself can suppress EAE. The ability of 1,25(OH)2D3 to suppress EAE in mice is largely eliminated by a low calcium diet until hypercalcemia is induced by high doses of 1,25(OH)2D3 that causes mobilization of calcium from the skeleton. Of great importance is the finding that vitamin D deficiency prevents EAE, a finding dramatically opposite to the original hypothesis. Further, vitamin D receptor knock out animals do not develop EAE supporting the idea that vitamin D does not suppress EAE. Upon revisiting the inverse relationship between light exposure and incidence of MS, a narrow band of light (300-315 nm) was discovered that prevents EAE without a change in serum levels of 25 hydroxy vitamin D (indicator of vitamin D status). Clinical trials are underway to explore the possible use of this narrow band light as a treatment to stop the progression of MS, while biochemical studies are underway to evaluate the mechanism of action of the narrow band light.


Assuntos
Esclerose Múltipla/tratamento farmacológico , Raios Ultravioleta , Deficiência de Vitamina D/tratamento farmacológico , Vitamina D/uso terapêutico , Animais , Humanos , Camundongos , Vitamina D/administração & dosagem
3.
Br J Cancer ; 108(2): 301-10, 2013 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-23322194

RESUMO

BACKGROUND: Quality of life is an important end point in clinical trials, yet there are few quality of life questionnaires for neuroendocrine tumours. METHODS: This international multicentre validation study assesses the QLQ-GINET21 Quality of Life Questionnaire in 253 patients with gastrointestinal neuroendocrine tumours. All patients were requested to complete two quality of life questionnaires - the EORTC Core Quality of Life questionnaire (QLQ-C30) and the QLQ-GINET21 - at baseline, and at 3 and 6 months post-baseline; the psychometric properties of the questionnaire were then analysed. RESULTS: Analysis of QLQ-GINET21 scales confirmed appropriate aggregation of the items, except for treatment-related symptoms, where weight gain showed low correlation with other questions in the scale; weight gain was therefore analysed as a single item. Internal consistency of scales using Cronbach's α coefficient was >0.7 for all parts of the QLQ-GINET21 at 6 months. Intraclass correlation was >0.85 for all scales. Discriminant validity was confirmed, with values <0.70 for all scales compared with each other.Scores changed in accordance with alterations in performance status and in response to expected clinical changes after therapies. Mean scores were similar for pancreatic and other tumours. CONCLUSION: The QLQ-GINET21 is a valid and responsive tool for assessing quality of life in the gut, pancreas and liver neuroendocrine tumours.


Assuntos
Neoplasias Gastrointestinais/psicologia , Tumores Neuroendócrinos/psicologia , Qualidade de Vida , Inquéritos e Questionários , Adulto , Idoso , Idoso de 80 Anos ou mais , Coleta de Dados , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Sistemas Neurossecretores/patologia
4.
Br J Surg ; 100(1): 138-43, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23165484

RESUMO

BACKGROUND: Recent developments in perioperative pathophysiology and care have documented evidence-based, multimodal rehabilitation (fast-track) to hasten recovery and to decrease morbidity and hospital stay for several major surgical procedures. The aim of this study was to investigate the effect of introducing fast-track principles for perioperative care in unselected patients undergoing open or laparoscopic liver resection. METHODS: This was a prospective study involving the first 100 consecutive patients who followed fast-track principles for liver resection. Catheters and drains were systematically removed early, and patients were mobilized and started eating and drinking from the day of surgery. An opioid-sparing multimodal pain treatment was given for the first week. Discharge criteria were: pain sufficiently controlled by oral analgesics alone, patient comfortable with discharge and no untreated complications. RESULTS: Median length of stay (LOS) for all patients was 5 days, with 2 days after laparoscopic versus 5 days following open resection (P < 0·001). Median LOS after minor open resections (fewer than 3 segments) was 5 days versus 6 days for major resections (3 or more segments) (P < 0·001). Simple right or left hemihepatectomies had a median LOS of 5 days. The readmission rate was 6·0 per cent and 30-day mortality was zero. CONCLUSION: Fast-track principles for perioperative care were introduced successfully and are safe after liver resection. Routine discharge 2 days after laparoscopic resection and 4-5 days after open liver resection may be feasible.


Assuntos
Hepatectomia/reabilitação , Hepatectomia/estatística & dados numéricos , Tempo de Internação , Assistência Perioperatória/métodos , Assistência Perioperatória/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/secundário , Carcinoma Hepatocelular/cirurgia , Feminino , Hepatectomia/efeitos adversos , Hepatectomia/métodos , Humanos , Laparoscopia/reabilitação , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , Adulto Jovem
5.
Arch Biochem Biophys ; 523(1): 87-94, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22406438

RESUMO

Vitamin D therapies for renal disease have been used for over a half century and are likely to be utilized for many more years. Past roles have been to alter calcium and phosphorus metabolism to prevent or lessen bone disease and reduce PTH levels in dialysis patients and more recently, pre-dialysis patients. However, emerging evidence indicates new applications for vitamin D compounds are likely to exist for this patient population. In addition to the possible new targets in this therapeutic area, a popularly debated topic is the ideal form of vitamin D for use in renal disease. Because the vitamin D metabolism system is severely altered in kidney disease, a thorough understanding of the disease progression relative to the vitamin D signaling pathway is necessary. The current state of knowledge in this area with the primary focus on patients with diabetic nephropathy will be the scope of this review.


Assuntos
Nefropatias Diabéticas , Vitamina D , Animais , Ensaios Clínicos como Assunto , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/patologia , Humanos , Transdução de Sinais/efeitos dos fármacos , Vitamina D/análogos & derivados , Vitamina D/farmacologia , Vitamina D/uso terapêutico
6.
Diabetes ; 49(9): 1590-6, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10969845

RESUMO

A backcross model of New Zealand obese mice (NZO) with the lean, atherosclerosis-resistant SJL strain was established to locate genes responsible for obesity, insulin resistance, and type 2 diabetes-like hyperglycemia. In male NZO x F1 backcross mice, a major susceptibility locus for the development of hyperglycemia and hypoinsulinemia (Nidd/SJL) was identified on chromosome 4 between the markers D4Mit278 and D4Mit232, 10-28 cM distal of the previously described Nidd1 locus. The diabetogenic allele has presumably been contributed by the SJL genome, and it appeared to be responsible for approximately 60% of the total prevalence of hyperglycemia. The presence of Nidd/SJL did not alter body weight or weight gain by week 12. Thereafter, it was associated with reduced weight gain or weight loss, presumably as a consequence of decompensated hyperglycemia. In all male backcross mice, the prevalence of hyperglycemia at week 22 increased with the body weight at week 12, suggesting that the development of hyperglycemia was dependent on the degree of obesity. In the absence of Nidd/SJL, mice weighing <50 g at week 12 did not develop hyperglycemia by week 22. In contrast, in animals carrying the diabetogenic allele, the prevalence of hyperglycemia was 20 and 64% when the 12-week weight was <45 and 45-50 g, respectively. These data are consistent with the conclusion that Nidd/SJL represents a diabetes gene that lowers the obesity threshold for the development of hyperglycemia and hypoinsulinemia.


Assuntos
Mapeamento Cromossômico , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus/genética , Predisposição Genética para Doença/genética , Hiperglicemia/genética , Obesidade/genética , Envelhecimento , Animais , Glicemia/metabolismo , Índice de Massa Corporal , Peso Corporal , Colesterol/sangue , Cruzamentos Genéticos , Diabetes Mellitus/sangue , Diabetes Mellitus/fisiopatologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Hiperglicemia/sangue , Hiperglicemia/fisiopatologia , Insulina/sangue , Masculino , Camundongos , Camundongos Endogâmicos , Camundongos Mutantes , Obesidade/sangue , Obesidade/fisiopatologia , Triglicerídeos/sangue
7.
J Clin Endocrinol Metab ; 89(7): 3152-7, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15240586

RESUMO

Endemic hypovitaminosis D contributes to osteoporosis development. However, variation in 25-hydroxyvitamin D (25OHD) measurement is reported and confounds the diagnosis of vitamin D insufficiency/deficiency. This report emphasizes the marked variability observed in serum 25OHD measurements between laboratories.Initially, postmenopausal women had serum 25OHD determinations: 42 in laboratory A, 20 in laboratory B. Their mean (sem) serum 25OHD concentrations were 46 (2.1) and 21 (2.3) ng/ml in laboratories A and B, respectively. Furthermore, there was little overlap in serum 25OHD among these clinically similar individuals. Specifically, 17% of those measured in laboratory A but 90% in laboratory B were below an arbitrary threshold value of 32 ng/ml.Subsequently, serum was obtained from 10 healthy adults. Two aliquots from each individual, one of which was spiked with 20 ng/ml 25OHD, were sent to six laboratories. Substantial variability was noted between these six laboratories. The mean serum 25OHD concentration ranged from 17.1-35.6 ng/ml. Similarly, the mean increase produced by spiking with 20 ng/ml ranged from 7.7-18.0 ng/ml.In conclusion, 25OHD assays yield markedly differing results; whether an individual is found to have low or normal vitamin D status is a function of the laboratory used. If the medical community is to make progress in correcting widespread hypovitaminosis D, 25OHD measurement must be standardized.


Assuntos
Testes Hematológicos/normas , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/diagnóstico , Vitamina D/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Técnicas de Laboratório Clínico/normas , Feminino , Humanos , Pessoa de Meia-Idade , Concentração Osmolar , Padrões de Referência , Reprodutibilidade dos Testes , Vitamina D/sangue
8.
Crit Rev Eukaryot Gene Expr ; 7(4): 299-342, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9607169

RESUMO

The discovery and development of information surrounding the retinoic acid receptors (RAR and RXR) has ushered in a new era in understanding the molecular mechanism of action of vitamin A in embryonic development and cellular differentiation. The mechanisms involved in the regulation of gene expression by the retinoids is at least partially known and involves binding of the RAR and RXR to retinoic acid response elements. Additional factors, including coregulatory proteins, associated regulatory elements, and cell-specific factors, may also be involved in determining the specificity of retinoid-regulation of gene expression during development. During embryogenesis, retinoids are required for the development of the posterior hindbrain and its associated structures, as well as for the survival and differentiation of certain classes of neurons and neural crest cell derivatives. At least some of the effects of retinoid on hindbrain development are related to the regulation of Hox gene expression. Additional retinoid-regulated genes have been implicated in nervous system development, and the manner in which they lead to phenotypic changes during embryogenesis remains to be determined.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Sistema Nervoso/embriologia , Sistema Nervoso/crescimento & desenvolvimento , Retinoides/farmacologia , Animais , Humanos , Sistema Nervoso/efeitos dos fármacos , Retinoides/metabolismo
9.
J Mol Endocrinol ; 32(1): 195-208, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14766002

RESUMO

New Zealand obese (NZO) mice exhibit severe insulin resistance of hepatic glucose metabolism. In order to define its biochemical basis, we studied the differential expression of genes involved in hepatic glucose and lipid metabolism by microarray analysis. NZOxF1 (SJLxNZO) backcross mice were generated in order to obtain populations with heterogeneous metabolism but comparable genetic background. In these backcross mice, groups of controls (normoglycemic/normoinsulinemic), insulin-resistant (normoglycemic/hyperinsulinemic) and diabetic (hyperglycemic/hypoinsulinemic) mice were identified. At 22 weeks, mRNA was isolated from liver, converted to cDNA, and used for screening of two types of cDNA arrays (high-density filter arrays and Affymetrix oligonucleotide microarrays). Differential gene expression was ascertained and assessed by Northern blotting. The data indicate that hyperinsulinemia in the NZO mouse is associated with: (i) increased mRNA levels of enzymes involved in lipid synthesis (fatty acid synthase, malic enzyme, stearoyl-CoA desaturase) or fatty acid oxidation (cytochrome P450 4A14, ketoacyl-CoA thiolase, acyl-CoA oxidase), (ii) induction of the key glycolytic enzyme pyruvate kinase, and (iii) increased mRNA levels of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase. These effects were enhanced by a high-fat diet. In conclusion, the pattern of gene expression in insulin-resistant NZO mice appears to reflect a dissociation of the effects of insulin on genes involved in glucose and lipid metabolism. The data are consistent with a hypothetical scenario in which an insulin-resistant hepatic glucose production produces hyperinsulinemia, and an enhanced insulin- and substrate-driven lipogenesis further aggravates the deleterious insulin resistance of glucose metabolism.


Assuntos
Ácidos Graxos/metabolismo , Gluconeogênese/fisiologia , Hiperglicemia/metabolismo , Resistência à Insulina/fisiologia , Fígado/enzimologia , Animais , Glicemia/análise , Glicemia/metabolismo , Enzimas/metabolismo , Camundongos , Camundongos Obesos , Obesidade/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Piruvato Quinase/metabolismo , RNA Mensageiro/genética
10.
Exp Biol Med (Maywood) ; 226(8): 766-75, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11520943

RESUMO

Both nerve growth factor (NGF) and neurotrophin-3 (NT-3) are necessary for the survival of embryonic sympathetic neurons in vivo. All-trans retinoic acid (atRA) has been shown to promote neurite outgrowth and long-term survival of chick embryonic sympathetic neurons cultured in the presence of NGF. The present study shows that atRA can also potentiate the survival and neurite outgrowth-promoting activities of NT-3. This was accomplished by enhancing the survival of existing neurons, as cell proliferation was unaffected by exposure to atRA. atRA also enhanced neurite outgrowth of the NT-3-treated cells; however, the neurites appeared thicker and less branched than cells treated with atRA in combination with NGF. Using a quantitative PCR assay, trkA and p75(NTR) mRNAs, but not trkC mRNA, were increased ( approximately 1.5- to 2-fold) after 72 and 48 hr of exposure of the cultures to atRA, respectively. The atRA-induced increase in trkA mRNA may play a role in the enhanced survival of neurons cultured in the presence of either NGF or NT-3, as both neurotrophins have been shown to signal through this receptor. The time course of these mRNA changes would indicate that atRA does not regulate the neurotrophin receptor mRNA directly, rather, intervening gene transcription is required. Thus, during development, atRA may play a role in fine-tuning embryonic responsiveness to both NT-3 and NGF.


Assuntos
Neurônios/citologia , Neurônios/metabolismo , Neurotrofina 3/uso terapêutico , Tretinoína/uso terapêutico , Animais , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Embrião de Galinha , Interações Medicamentosas , Ceratolíticos/uso terapêutico , Fator de Crescimento Neural/farmacologia , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/metabolismo , Receptor de Fator de Crescimento Neural , Receptor trkA/biossíntese , Receptor trkC/biossíntese , Receptores de Fator de Crescimento Neural/biossíntese , Fatores de Tempo
11.
Clin Nutr ; 21(6): 461-8, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12468365

RESUMO

BACKGROUND AND AIMS: Many patients in hospitals are undernourished and nutritional care is inadequate in most hospitals. The aim of this investigation was to gain insight into how this situation could be improved. METHODS: Seven hundred and fifty randomly selected patients were screened at admission in three hospitals and surveyed during their entire hospitalization. Each time a patient was not treated according to a clearly defined nutritional standard, the nurse responsible for the patient was interviewed about possible reasons according to preformed questionnaires. RESULTS: The investigators found that 22% of the patients were nutritionally at-risk, and that only 25% of these patients received an adequate amount of energy and protein. The departments had only screened for nutritional problems in 60% of the cases. Only 47% of the patients, who the departments judged to be at-risk patients, had a nutrition plan worked out, and only about 30% of the at-risk patients were monitored by the departments by recording of dietary intake and/or body weight. The main causes for inadequate nutritional care were lack of instructions to deal with these problems, and lack of basic knowledge with respect to dietary requirements and practical aspects of the hospital's food provision. Patient-related aspects and the system of food provision also contributed, but only to a small degree. CONCLUSIONS: These findings form the basis of the strategy to improve nutritional care in these hospitals.


Assuntos
Serviço Hospitalar de Nutrição/normas , Fidelidade a Diretrizes/estatística & dados numéricos , Hospitalização , Distúrbios Nutricionais/epidemiologia , Qualidade da Assistência à Saúde , Índice de Massa Corporal , Dinamarca/epidemiologia , Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Feminino , Humanos , Incidência , Tempo de Internação , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Avaliação Nutricional , Distúrbios Nutricionais/terapia , Estado Nutricional , Medição de Risco , Inquéritos e Questionários
13.
Ugeskr Laeger ; 163(27): 3824-5, 2001 Jul 02.
Artigo em Da | MEDLINE | ID: mdl-11467007
16.
Osteoporos Int ; 17(5): 704-15, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16491322

RESUMO

INTRODUCTION: 2-Methylene-19-nor-(20S)-1alpha,25-dihydroxyvitamin D3 (2MD) is a new analog of 1alpha,25-dihydroxyvitamin D3 (1,25-(OH)2D3) that has unique properties (distinct from 1alpha,25-dihydroxyvitamin D3) in stimulating osteoblasts to form bone in culture. This analog has now been extensively tested in aged ovariectomized female rats maintained on a diet adequate in calcium and phosphorus. METHODS: Retired female rats obtained from Sprague-Dawley were ovariectomized, and were either dosed with vehicle or 2MD at 5-7 ng/kg body weight each day. RESULTS: A marked increase in total bone mass resulted during the 28-week study. This increase in bone mass resulted from an increase in both cortical and trabecular bone, with increases to the order of 25% in the cancellous bone. Histomorphometry revealed that 2MD increased bone mass primarily by increasing bone formation. It also revealed little or no effect on bone resorption. The resulting bone is of high quality revealed by histology and biomechanical testing. CONCLUSION: Throughout the study, serum calcium remained within the normal range and thus 2MD shows great promise for the treatment of bone diseases characterized by bone loss, including osteoporosis.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Reabsorção Óssea/tratamento farmacológico , Calcitriol/análogos & derivados , Osteogênese/efeitos dos fármacos , Osteoporose/tratamento farmacológico , Anabolizantes/uso terapêutico , Análise de Variância , Animais , Densidade Óssea/efeitos dos fármacos , Calcitriol/uso terapêutico , Cálcio/sangue , Feminino , Ratos , Ratos Sprague-Dawley
17.
Physiology (Bethesda) ; 20: 152-61, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15888572

RESUMO

Insulin resistance and type 2 diabetes are serious public health threats. Although enormous research efforts have been focused on the pathogenesis of these diseases, the underlying mechanisms remain only partly understood. Here we review mouse phenotypes resulting from inactivation of molecules responsible for the control of glucose metabolism that have led to novel insights into insulin action and the development of insulin resistance. In addition, more sophisticated strategies to manipulate genes in mice in the future are presented.


Assuntos
Diabetes Mellitus Tipo 2/fisiopatologia , Modelos Animais de Doenças , Resistência à Insulina/fisiologia , Camundongos Knockout , Camundongos Transgênicos , Animais , Camundongos
18.
Arch Biochem Biophys ; 319(2): 457-63, 1995 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-7786028

RESUMO

Two families of nuclear retinoid receptors, retinoic acid receptor and retinoid X receptor (RAR and RXR respectively), and a family of cellular retinoic acid-binding proteins (CRABPI and II) participate in the retinoic acid (RA) signaling pathway. The presence and function of many of these receptors and cellular binding proteins have not been fully explored in RA-responsive human neuroblastoma cells. We have previously shown that RAR transcripts and protein are present in human neuroblastoma cells, and that all-trans RA induces the expression of the RAR beta mRNA. In this paper, we demonstrate that human neuroblastoma cells express mRNA for RXR alpha and beta. The mRNA for CRABPI is present in untreated human neuroblastoma cells, whereas the mRNA for CRABPII is induced in cells treated with either all-trans RA or 9-cis RA. Furthermore, 9-cis RA, a ligand that binds to both the RAR and the RXR families, selectively activates the CRABPII gene. In contrast, all-trans RA and 9-cis RA are equally effective in the induction of RAR beta transcript and inhibition of cell proliferation. Since both retinoids inhibit human neuroblastoma cell proliferation, it appears that induction of RAR beta rather than of CRABPII is more likely linked to the regulation of human neuroblastoma cell growth.


Assuntos
Neuroblastoma/metabolismo , Receptores do Ácido Retinoico/biossíntese , Tretinoína/farmacologia , Sequência de Bases , Divisão Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Humanos , Dados de Sequência Molecular , Neuroblastoma/genética , Reação em Cadeia da Polimerase , RNA Mensageiro/biossíntese , Receptores do Ácido Retinoico/genética , Células Tumorais Cultivadas
19.
Dev Dyn ; 205(1): 52-63, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8770551

RESUMO

In explanted embryonic chick sympathetic neurons, all-trans retinoic acid (RA) as well as nerve growth factor (NGF) were found to be required for neuronal survival and neurite outgrowth at early stages of development (day 6.5-7) in agreement with previous work (Rodriguez-Tébar and Rohrer [1991] Development 112:813-820). The dependence of neurons on all-trans RA for survival diminished at later stages of development. However, all-trans RA was found to be needed at all stages of development in order to maximize neurite outgrowth. Further, removal of all-trans RA from the cultures led to a rapid degeneration of the formed neurites, demonstrating the essentiality of all-trans RA for both the development of neurites, and for the maintenance of existing neurites in cultured embryonic sympathetic neurons. The mechanism whereby all-trans RA exerts its effects on embryonic sympathetic neurons may involve activation of the nuclear retinoic acid and retinoid-X receptor (RAR and RXR) families. The results of Northern blot analyses and/or reverse transcriptase-polymerase chain reaction (RT-PCR) studies show that embryonic sympathetic ganglia express RAR beta, RAR gamma and RXR gamma mRNAs. RXR gamma mRNA is expressed at highest levels in immature neurons that are not yet responsive to NGF (day 6.5-7) and message levels decline with increasing developmental age. In contrast, RAR beta transcript levels are barely detectable at day 6.5-7, and increase approximately 4-fold in ganglia from embryos at day 8.5-9 and decline thereafter. RT-PCR studies show that RAR gamma mRNA is expressed both early (day 6.5-7) and late (day 15) in ganglionic development. Transcripts for the NGF receptors, p75NGFR and p140trk were also examined. The appearance of a single 2.7 kb p140trk transcript coincides with the time when RAR beta mRNA is maximally expressed, raising the possibility that NGF receptors may be targets of retinoid action. Evidence is also presented that all-trans RA may enhance neurite outgrowth by mechanisms other than simply inducing NGF-responsiveness of neurons.


Assuntos
Gânglios Simpáticos/efeitos dos fármacos , Neuritos/efeitos dos fármacos , Tretinoína/farmacologia , Animais , Sequência de Bases , Células Cultivadas , Embrião de Galinha , Primers do DNA/genética , Gânglios Simpáticos/embriologia , Gânglios Simpáticos/ultraestrutura , Dados de Sequência Molecular , Fatores de Crescimento Neural/farmacologia , Neuritos/ultraestrutura , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Fator de Crescimento Neural/genética , Receptores de Fator de Crescimento Neural/metabolismo , Receptores do Ácido Retinoico/genética , Receptores do Ácido Retinoico/metabolismo , Receptores X de Retinoides , Fatores de Tempo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
20.
Diabetologia ; 43(12): 1565-72, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11151768

RESUMO

AIMS/HYPOTHESIS: To locate genes responsible for obesity and insulin resistance, a backcross model of New Zealand obese (NZO) mice with the lean Swiss/Jackson Laboratory (SJL) strain was stablished. RESULTS: In female NZO x F1 backcross mice, two major quantitative trait loci for variables of obesity (body weight, body mass index, total body fat) and insulin resistance (hyperinsulinaemia) were identified on chromosomes 5 (Nob1) and 19 (Nob2) close to the markers D5Mit392 and D19Mit91. The aberrant alleles have presumably contributed by the NZO genome. Whereas Nob1 contributed mainly to higher body weight, Nob2 seemed to mainly aggravate insulin resistance independent of obesity. The leptin receptor variant of NZO (LeprA720T/T1044I) failed to alter any of the variables of obesity. It seemed, however, to enhance the effect of Nob1 on body weight and that of Nob2 on serum insulin concentration. When expressed in COS-7 cells, LeprA720T/T10441 produced a normal basal and maximum activation with a minor increase in the EC50 of leptin. CONCLUSIONS/INTERPRETATION: The data identify two new quantitative trait loci that are responsible for a major part of obesity and hyperinsulinaemia as produced by recessive genes in NZO mice. LeprA720T/T1044I alone cannot produce obesity, but may enhance the effects of other obesity/insulin resistance genes in this mouse model.


Assuntos
Proteínas de Transporte/genética , Mapeamento Cromossômico , Resistência à Insulina/genética , Camundongos Obesos/genética , Obesidade/genética , Característica Quantitativa Herdável , Receptores de Superfície Celular , Tecido Adiposo/anatomia & histologia , Animais , Glicemia/metabolismo , Índice de Massa Corporal , Peso Corporal , Células COS , Proteínas de Transporte/metabolismo , Chlorocebus aethiops , Cruzamentos Genéticos , Feminino , Insulina/sangue , Masculino , Camundongos , Nova Zelândia , Receptores para Leptina , Transfecção
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