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1.
BJU Int ; 133 Suppl 4: 53-63, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38379076

RESUMO

OBJECTIVE: To compare perioperative morbidity, functional and quality-of-life (QoL) outcomes in patients with partial cystectomy vs radical cystectomy as part of pelvic exenteration. PATIENTS AND METHODS: Retrospective analysis of a prospectively maintained database of pelvic exenteration patients (1998-2021) was conducted in a single centre. Study outcomes included postoperative complications, quality-of-life, functional and stoma-related outcomes. The 36-item Short-Form Health Survey Physical and Mental Health Components, Functional Assessment of Cancer Therapy-Colorectal questionnaires and Distress Thermometer were available pre- and postoperatively. QoL outcomes were compared at the various time points. Stoma embarrassment and care scores were compared between patients with a colostomy, urostomy, and both. RESULTS: Urological complications were similar between both groups, but patients with partial cystectomy experienced less wound-related complications. Overall, 34/81 (42%) partial cystectomy patients reported one or more long-term voiding complication (i.e., incontinence [17 patients], frequency [six], retention [three], high post-voiding residuals [10], permanent suprapubic catheter/indwelling catheter [14], recurrent urinary tract infection [nine], percutaneous nephrostomy [three], progression to urostomy [three]). The QoL improved following surgery in both the partial and radical cystectomy groups, differences between cohorts were not significant. Patients with two stomas reported higher embarrassment scores than patients with one stoma, although this did not result in more difficulties in stoma care. CONCLUSIONS: Partial cystectomy patients have fewer postoperative wound-related complications than radical cystectomy patients, but often experience long-term voiding issues. The QoL outcomes are similar for both cohorts, with significant improvement following surgery.


Assuntos
Exenteração Pélvica , Neoplasias da Bexiga Urinária , Derivação Urinária , Humanos , Cistectomia/efeitos adversos , Exenteração Pélvica/efeitos adversos , Qualidade de Vida , Estudos Retrospectivos , Derivação Urinária/efeitos adversos , Complicações Pós-Operatórias/etiologia , Neoplasias da Bexiga Urinária/complicações
2.
Res Rep Urol ; 15: 113-121, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36968628

RESUMO

Purpose: Renal angiomyolipoma (AML) is the most common benign renal tumor. Whilst generally asymptomatic, they can cause life-threatening bleeding. Selective angioembolization (SAE) may be used to treat large symptomatic and asymptomatic AMLs. We aimed to evaluate the efficacy of SAE for symptomatic and asymptomatic renal AMLs and determine characteristics that predict spontaneous bleeding. Patients and Methods: Data were retrospectively collected from a prospectively maintained database from July 2011 to April 2022. Patients were included if AML was >4cm and they underwent subsequent SAE. Follow-up imaging was analyzed to calculate mean reduction in AML size. Clinical notes were reviewed to analyze lesion characteristics including vascularity, fat content and presence of aneurysm as well as post-procedural complications. Results: 26 patients with 30 AMLs were identified. Interval of follow-up imaging ranged from 1 to 60 months. 25 AMLs were embolized electively with 5 emergency embolizations performed for bleeding. Mean reduction in AML volume was 41% at 3 months (p=0.013) and 63% at 12 months (p=0.007). All 5 bleeding AMLs had a rich vascularity with 60% also having either aneurysms or a low fat content. Complications included post-embolic syndrome (n=9), segmental renal parenchyma devascularization (n=3), acute bleeding requiring re-embolization (n=2), nephrectomy for ongoing bleeding (n=1) and delayed bleeding managed conservatively (n=1). No deterioration in renal function was observed. Conclusion: SAE is an effective procedure for managing symptomatic and asymptomatic renal AML, with minimal significant complications. AML vascularity, fat content and aneurysms may be useful characteristics to assess future risk of bleeding in patients with renal AML.

3.
Clin Transplant ; 37(5): e14945, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36807636

RESUMO

INTRODUCTION: Demand for donor kidneys far exceeds the availability of organs from deceased donors. Living donor kidneys are an important part of addressing this shortfall, and laparoscopic nephrectomy is an important strategy to reduce donor morbidity and increase the acceptability of living donation. AIM: To retrospectively review the intraoperative and postoperative safety, technique, and outcomes of patients undergoing donor nephrectomy at a single tertiary hospital in Sydney, Australia. METHOD: Retrospective capture and analysis of clinical, demographic, and operative data for all living donor nephrectomies performed between 2007 and 2022 at a single University Hospital in Sydney, Australia. RESULTS: Four hundred and seventy-two donor nephrectomies were performed: 471 were laparoscopic, two of which were converted from laparoscopic to open and hand-assisted nephrectomy, respectively, and one (.2%) underwent primary open nephrectomy. The mean warm ischemia time was 2.8 min (±1.3 SD, median 3 min, range 2-8 min) and the mean length of stay (LOS) was 4.1 days (±1.0 SD). The mean renal function on discharge was 103 µmol/L (±23.0 SD). Seventy-seven (16%) patients had a complication with no Clavien Dindo IV or V complications seen. Outcomes demonstrated no impact of donor age, gender, kidney side, relationship to the recipient, vascular complexity; or surgeon experience, on complication rate or LOS. CONCLUSION: Laparoscopic donor nephrectomy is a safe and effective procedure with minimal morbidity and no mortality in this series.


Assuntos
Transplante de Rim , Laparoscopia , Doadores Vivos , Nefrectomia , Humanos , Austrália , Rim/fisiologia , Rim/cirurgia , Laparoscopia/métodos , Nefrectomia/métodos , Estudos Retrospectivos , Coleta de Tecidos e Órgãos/métodos
4.
Urology ; 173: 198-203, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36646175

RESUMO

INTRODUCTION: To describe a novel method of penile sparing perineal urethrectomy for locally advanced proximal primary urethral cancers (PUC). TECHNICAL CONSIDERATIONS: In mid-2021, 2 cases underwent pelvic exenterative surgery for pT3 and pT4 PUC. The procedure comprised of a complete urethrectomy, proximal penectomy, en bloc pubectomy and excision of pelvic diaphragm in both cases. One case included a wide excision of scrotum, whilst the other required a prostatectomy and abdominoperineal resection of the rectum to achieve complete tumor resection. A complete R0 resection was achieved in both cases. At 6 months follow up, there is no evidence of ischemic necrosis of the penis and cosmesis is satisfactory to both patients. We provide a comprehensive operative description of both cases, together with illustrations, and discuss the underlying principles of penile preservation in the surgical treatment of locally advanced proximal PUC. CONCLUSION: Complete perineal urethrectomy with phallic preservation is feasible in men with locally advanced proximal bulbar urethral cancer in the absence of tumor invasion of the penile shaft. The remnant penis survives off arterial supply from the superficial penile arteries arising from the external pudendal arteries. Phallic preservation may benefit patient's psychological quality of life post-procedure.


Assuntos
Carcinoma , Neoplasias Uretrais , Masculino , Humanos , Neoplasias Uretrais/cirurgia , Neoplasias Uretrais/patologia , Qualidade de Vida , Pênis/cirurgia , Uretra/cirurgia , Uretra/patologia , Carcinoma/patologia
5.
Eur J Surg Oncol ; 49(7): 1250-1257, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36658054

RESUMO

INTRODUCTION: In patients with locally advanced (LARC) or locally recurrent (LRRC) rectal cancer and bladder involvement, pelvic exenteration (PE) with partial (PC) or radical (RC) cystectomy can potentially offer a cure. The study aim was to compare PC and RC in PE patients in terms of oncological outcome, post-operative complications and quality-of-life (QoL). MATERIALS & METHODS: This was a retrospective cohort analysis of a prospectively maintained surgical database. Patients who underwent PE for LARC or LRRC cancer with bladder involvement between 1998 and 2021 were included. Post-operative complications and overall survival were compared between patients with PC and RC. RESULTS: 60 PC patients and 269 RC patients were included. Overall R0 resection was 84.3%. Patients with LRRC and PC had poorest oncological outcome with 69% R0 resection; patients with LARC and PC demonstrated highest R0 rate of 96.3% (P = 0.008). Overall, 1-, 3- and 5-year OS was 90.8%, 68.1% and 58.6% after PC, and 88.7%, 62.2% and 49.5% after RC. Rates of urinary sepsis or urological leaks did not differ between groups, however, RC patients experienced significantly higher rates of perineal wound- and flap-related complications (39.8% vs 25.0%, P = 0.032). CONCLUSION: PC as part of PE can be performed safely with good oncological outcome in patients with LARC. In patients with LRRC, PC results in poor oncological outcome and a more aggressive surgical approach with RC seems justified. The main benefit of PC is a reduction in wound related complications compared to RC, although more urological re-interventions are observed in this group.


Assuntos
Exenteração Pélvica , Neoplasias Retais , Humanos , Cistectomia/métodos , Bexiga Urinária/cirurgia , Exenteração Pélvica/métodos , Estudos Retrospectivos , Qualidade de Vida , Recidiva Local de Neoplasia/cirurgia , Neoplasias Retais/cirurgia , Complicações Pós-Operatórias/etiologia , Resultado do Tratamento
7.
J Surg Case Rep ; 2022(11): rjac547, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36452279

RESUMO

A bifid ureter is an atypical anatomical variation that occurs with an incidence of 1-10%. This anomaly is in a continuum of duplex collecting systems and most commonly involves a common distal ureter. This is usually asymptomatic and is predominantly an incidental diagnosis, nevertheless, is a potential risk factor for urolithiasis formation. Current surgical management of larger staghorn calculi favours percutaneous nephrolithotomy (PCNL) over traditional open surgery, however for multiple calculi and complex anatomy PCNL would require multiple punctures, with increased risk of bleeding, pleural injury, sepsis and ultimately failed stone clearance. We describe the case of a 71-year-old female with multiple calculi in bifid anatomy. A single open approach, aided with cold-ischaemia was successfully utilized in this context.

8.
Diagnostics (Basel) ; 12(11)2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36359439

RESUMO

Prostate cancer is the most common cancer and the second leading cause of cancer death in men. The imaging assessment and treatment of prostate cancer has vastly improved over the past decade. The introduction of PSMA PET-CT has improved the detection of loco-regional and metastatic disease. PSMA PET-CT also has a role in the primary diagnosis and staging, in detecting biochemical recurrence after curative treatment and in metastasis-directed therapy. In this paper we review the role of PSMA PET-CT in prostate cancer.

9.
Urol Case Rep ; 45: 102262, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36267343

RESUMO

The diagnosis of genital dermatological conditions in males can be challenging and rely on physical examination and biopsy. This report describes an unusual case of Zoon's balanitis producing a discrete polyp on the glans penis, in addition to the classically described well-demarcated erythematous macule.

10.
Urol Case Rep ; 45: 102206, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36105545

RESUMO

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a rare genetic disorder characterised by a germline mutation of the fumarate hydratase (FH) gene, in which affected individuals have a high likelihood of developing cutaneous leiomyomas, uterine leiomyomas and renal cell cancer (RCC). HLRCC-associated RCC is characterised by presentation at a younger age than the sporadic form, its aggressive nature and rapid metastatic potential. We present the case of a 50 year old woman with FH mutation, a history of early onset symptomatic uterine leiomyomas, and RCC with the first reported case of an isolated metastasis to the pituitary gland.

11.
Mol Cancer ; 13: 79, 2014 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-24708856

RESUMO

BACKGROUND: Acute myeloid leukaemia (AML) is characterised by the halt in maturation of myeloid progenitor cells, combined with uncontrolled proliferation and abnormal survival, leading to the accumulation of immature blasts. In many subtypes of AML the underlying causative genetic insults are not fully described. MicroRNAs are known to be dysregulated during oncogenesis. Overexpression of miR-155 is associated with some cancers, including haematological malignancies, and it has been postulated that miR-155 has an oncogenic role. This study investigated the effects of modulating miR-155 expression in human AML cells, and its mechanism of action. RESULTS: Analysis of miR-155 expression patterns in AML patients found that Fms-like tyrosine kinase 3 (FLT3)-wildtype AML has the same expression level as normal bone marrow, with increased expression restricted to AML with the FLT3-ITD mutation. Induction of apoptosis by cytarabine arabinoside or myelomonocytic differentiation by 1,23-dihydroxyvitaminD3 in FLT3-wildtype AML cells led to upregulated miR-155 expression. Knockdown of miR-155 by locked nucleic acid antisense oligonucleotides in the FLT3-wildtype AML cells conferred resistance to cytarabine arabinoside induced apoptosis and suppressed the ability of cells to differentiate.Ectopic expression of miR-155 in FLT3-wildtype AML cells led to a significant gain of myelomonocytic markers (CD11b, CD14 and CD15), increase in apoptosis (AnnexinV binding), decrease in cell growth and clonogenic capacity.In silico target prediction identified a number of putative miR-155 target genes, and the expression changes of key transcription regulators of myeloid differentiation and apoptosis (MEIS1, GF1, cMYC, JARID2, cJUN, FOS, CTNNB1 and TRIB2) were confirmed by PCR. Assessment of expression of apoptosis-related proteins demonstrated a marked increase in cleaved caspase-3 expression confirming activation of the apoptosis cascade. CONCLUSIONS: This study provides evidence for an anti-leukaemic role for miR-155 in human FLT3-wildtype AML, by inducing cell apoptosis and myelomonocytic differentiation, which is in contrast to its previously hypothesized role as an oncogene. This highlights the complexity of gene regulation by microRNAs that may have tumour repressor or oncogenic effects depending on disease context or tissue type.


Assuntos
Epigênese Genética , Leucemia Mieloide Aguda/genética , MicroRNAs/genética , Proteínas de Neoplasias/genética , Tirosina Quinase 3 Semelhante a fms/genética , Antígenos CD/genética , Antígenos CD/metabolismo , Antimetabólitos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3/genética , Caspase 3/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citarabina/farmacologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Células HL-60 , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , MicroRNAs/metabolismo , Mutação , Proteínas de Neoplasias/metabolismo , Transdução de Sinais , Análise de Sobrevida , Células Tumorais Cultivadas , Tirosina Quinase 3 Semelhante a fms/metabolismo
12.
Mol Cancer ; 11: 8, 2012 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-22348345

RESUMO

BACKGROUND: Acute myeloid leukaemia (AML) with nucleophosmin-1 (NPM1) mutation is a major subtype of AML. The NPM1 mutation induces a myeloproliferative disorder, but evidence indicates that other insults are necessary for the development of AML. We utilised microRNA microarrays and functional assays to determine if microRNA dysregulation could be involved in the pathogenesis of in NPM1 mutated (NPM1mut)-AML. RESULTS: We used a stringent locked nucleic acid (LNA) based microRNA microarray platform to profile bone marrow samples of patients with normal karyotype AML. A panel of five microRNAs dichotomised AML patients according to their NPM1 mutational status. miR-10a, let-7b and let-7c were significantly over-expressed, while miR-130a and miR-335 were under-expressed in NPM1mut-AML when compared to NPM1wildtype-AML. Of these, miR-10a is the most differentially expressed in NPM1mut-AML versus NPM1wildtype-AML (> 10 fold higher as confirmed by qRT-PCR). To investigate the functions of miR-10a, the OCI-AML3 cell line was utilised, which is the only commercially available cell line bearing NPM1mut. OCI-AML3 cells were firstly demonstrated to have a similarly high miR-10a expression to primary NPM1mut-AML patient samples. Inhibition of miR-10a expression by miRCURY LNA Inhibitors (Exiqon) in these cells resulted in increased cell death as assessed by MTS, cell cycle and Annexin-V assays and reduced clonogenic capacity, indicative of an involvement in leukaemic cell survival. In silico filtering of bioinformatically predicted targets of miR-10a identified a number of potential mRNA targets with annotated functions in haematopoiesis, cell growth and apoptosis. Lucferase reporter assays confirmed a number of these putative tumorogenic genes that are miR-10a suppressible including KLF4 and RB1CC1. This provides a potential mechanism for the pathogenic role of miR-10a in NPM1mut-AML. CONCLUSIONS: This study provides, for the first time, in vitro evidence of a pro-survival role of miR-10a in NPM1mut-AML, that it may contribute to the pathogenesis of NPM1mut-AML and identifies putative tumorogenic targets.


Assuntos
Leucemia Mieloide Aguda/genética , MicroRNAs/genética , Mutação , Proteínas Nucleares/genética , Morte Celular/genética , Análise por Conglomerados , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica , Inativação Gênica , Humanos , Fator 4 Semelhante a Kruppel , Nucleofosmina , Oligonucleotídeos Antissenso/farmacologia
13.
J Cell Mol Med ; 16(5): 978-87, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22225649

RESUMO

In the relatively short period of time since their discovery, microRNAs have been shown to control many important cellular functions such as cell differentiation, growth, proliferation and apoptosis. In addition, microRNAs have been demonstrated as key drivers of many malignancies and can function as either tumour suppressors or oncogenes. The haematopoietic system is not outside the realm of microRNA control with microRNAs controlling aspects of stem cell and progenitor self-renewal and differentiation, with many, if not all, haematological disorders associated with aberrant microRNA expression and function. In this review, we focus on the current understanding of microRNA control of haematopoiesis and detail the evidence for the contribution and clinical relevance of aberrant microRNA function to the characteristic block of differentiation in acute myeloid leukaemia.


Assuntos
Diferenciação Celular/fisiologia , Leucemia Mieloide Aguda/fisiopatologia , MicroRNAs/fisiologia , Mielopoese/fisiologia , Animais , Apoptose/fisiologia , Regulação Neoplásica da Expressão Gênica , Células-Tronco Hematopoéticas/fisiologia , Humanos , Macrófagos/fisiologia , Camundongos , MicroRNAs/metabolismo
14.
Am J Hematol ; 86(1): 2-11, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20981674

RESUMO

MicroRNAs are short ribonucleic acids (RNAs) that play an important role in many aspects of cellular biology such as differentiation and apoptosis, due to their role in the regulation of gene expression. Using microRNA microarrays, we characterized the microRNA gene expression of 27 patients with acute myeloid leukemia (AML) with normal cytogenetics, focusing on the microRNAs differentially expressed between the M1 and M5 French-American-British (FAB) subtypes. An accurate delineation of these two AML entities was observed based on the expression of 12 microRNAs. We hypothesized that these microRNAs may potentially be involved in the differentiation block of M1 blasts and consequently monocytic differentiation. Using publically available mRNA data and microRNA target prediction software, we identified several key myeloid factors that may be targeted by our candidate microRNAs. The expression changes of the candidate microRNAs during monocytic differentiation of AML cell lines treated with Vitamin D and phorbol 12-myristate 13-acetate were examined. All six candidate microRNAs were significantly down-regulated over the time course by quantitative reverse transcriptase polymerase chain reaction suggesting a link between these microRNAs and monocytic differentiation. To further characterize these microRNAs, we confirmed by luciferase assays that these microRNA target several key myeloid factors such as MAFB, IRF8, and KLF4 identifying a possible mechanism for the control of differentiation by these microRNAs.


Assuntos
Leucemia Mieloide Aguda/genética , MicroRNAs/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise por Conglomerados , Citogenética , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Humanos , Fator 4 Semelhante a Kruppel , Leucemia Mieloide Aguda/patologia , Masculino , MicroRNAs/metabolismo , Análise em Microsséries , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto Jovem
15.
Regen Med ; 3(1): 33-47, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18154461

RESUMO

In the past 10 years there have been substantial developments in adult stem cell research, and the transplantation of these cells now holds great promise for regenerative medicine, such as in the treatment of Type 1 diabetes. A large proportion of studies have focused on stem cells sourced from hematopoietic tissues: bone marrow, umbilical cord blood and peripheral blood. Attempts to transdifferentiate these cells into insulin-producing cells, both in vivo and in vitro, have produced conflicting results. Although insulin production and normalization of blood glucose levels have been described in some studies, the true mechanism of stem cell plasticity remains in question - are the functional changes seen due to true transdifferentiation or do they result from cell fusion or other factors? There is evidence that stem cell plasticity is a true phenomenon, but whether it will ever be of therapeutic benefit for Type 1 diabetes remains uncertain.


Assuntos
Células-Tronco Adultas , Diabetes Mellitus Tipo 1/terapia , Ilhotas Pancreáticas/patologia , Adulto , Células-Tronco Adultas/citologia , Animais , Diferenciação Celular , Feminino , Humanos , Transplante das Ilhotas Pancreáticas , Masculino , Medicina Regenerativa
16.
BMC Neurosci ; 7: 41, 2006 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-16716234

RESUMO

BACKGROUND: The responses of adult parasympathetic ganglion neurons to injury and the neurotrophic mechanisms underlying their axonal regeneration are poorly understood. This is especially relevant to penis-projecting parasympathetic neurons, which are vulnerable to injury during pelvic surgery such as prostatectomy. We investigated the changes in pelvic ganglia of adult male rats in the first week after unilateral cavernous (penile) nerve axotomy (cut or crush lesions). In some experiments FluoroGold was injected into the penis seven days prior to injury to allow later identification of penis-projecting neurons. Neurturin and glial cell line-derived neurotrophic factor (GDNF) are neurotrophic factors for penile parasympathetic neurons, so we also examined expression of relevant receptors, GFRalpha1 and GFRalpha2, in injured pelvic ganglion neurons. RESULTS: Axotomy caused prolific growth of axon collaterals (sprouting) in pelvic ganglia ipsilateral to the injury. These collaterals were most prevalent in the region near the exit of the penile nerve. This region contained the majority of FluoroGold-labelled neurons. Many sprouting fibres formed close associations with sympathetic and parasympathetic pelvic neurons, including many FluoroGold neurons. However immunoreactivity for synaptic proteins could not be demonstrated in these collaterals. Preganglionic terminals showed a marked loss of synaptic proteins, suggesting a retrograde effect of the injury beyond the injured neurons. GFRalpha2 immunofluorescence intensity was decreased in the cytoplasm of parasympathetic neurons, but GFRalpha1 immunofluorescence was unaffected in these neurons. CONCLUSION: These studies show that there are profound changes within the pelvic ganglion after penile nerve injury. Sprouting of injured postganglionic axons occurs concurrently with structural or chemical changes in preganglionic terminals. New growth of postganglionic axon collaterals within the ganglion raises the possibility of the formation of aberrant synaptic connections between injured and un-injured ganglion neurons. Together these changes demonstrate a broader effect on the pelvic autonomic circuitry than simply loss of neuroeffector connections. These structural changes are accompanied by potential changes in neurotrophic factor signalling due to altered expression of receptors for members of the GDNF family. Together our results advance understanding of the responses of pelvic autonomic nerve circuits to injury and may assist in designing strategies for promoting regeneration.


Assuntos
Axotomia , Gânglios Parassimpáticos/citologia , Substâncias de Crescimento/metabolismo , Neurônios/metabolismo , Pênis/metabolismo , Transdução de Sinais/fisiologia , Animais , Regulação da Expressão Gênica/fisiologia , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Imuno-Histoquímica/métodos , Masculino , Pelve/inervação , Ratos , Sinaptofisina/metabolismo , Peptídeo Intestinal Vasoativo/metabolismo
17.
J Clin Endocrinol Metab ; 88(6): 2753-9, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12788884

RESUMO

Fetal pancreatic beta-cells release insulin poorly in response to glucose; however, the cellular mechanism for this is unknown. By using fura-2 to measure changes in the cytoplasmic free Ca(2+) concentration in beta-cells, we examined human/porcine fetal islet-like cell clusters (ICCs) and human adult islets for the presence of functional K(+)(ATP) and voltage-activated Ca(2+) ion channels. The effects of glucose, glyceraldehyde, leucine, KCl, and the channel effectors glipizide and BAY K8644 were studied. In fetal human/porcine ICCs and adult islets, KCl, glipizide, and BAY K8644 increased [Ca(2+)](i). Both glucose and glyceraldehyde increased [Ca(2+)](i) in islets but had no effect on ICCs. Leucine increased [Ca(2+)](i) in islets and porcine but not human ICCs. We hypothesize that the beneficial effect of leucine in fetal porcine, but not human ICCs, is attributable to time-dependent maturation of the beta-cells, because porcine ICCs examined were at 87% of the gestational period, and human ICCs were at 42%. Our data demonstrate that both K(+)(ATP) and voltage-activated Ca(2+) channels, required for glucose-stimulated increase in [Ca(2+)](i), are functional early in gestation. This suggests that the cause of the immaturity of fetal human/porcine beta-cells is at a more proximal step of glucose-induced metabolism than the channels on the cell surface.


Assuntos
Cálcio/metabolismo , Glucose/farmacologia , Insulina/metabolismo , Ilhotas Pancreáticas/embriologia , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Animais , Agonistas dos Canais de Cálcio/farmacologia , AMP Cíclico/farmacologia , Feto/efeitos dos fármacos , Feto/metabolismo , Glipizida/farmacologia , Humanos , Técnicas In Vitro , Secreção de Insulina , Membranas Intracelulares/metabolismo , Ilhotas Pancreáticas/metabolismo , Cloreto de Potássio/farmacologia , Suínos
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