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2.
Intern Med J ; 45(4): 454-6, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25827513

RESUMO

Delusional infestation remains a debilitating condition that is therapeutically challenging for clinicians. This case series identifies 23 patients with delusional infestation in an Australian setting. The majority of patients are women and unlikely to have a psychiatric comorbid background. The use of unnecessary anti-parasitic medication is prevalent.


Assuntos
Ectoparasitoses/diagnóstico , Ectoparasitoses/epidemiologia , Esquizofrenia Paranoide/diagnóstico , Esquizofrenia Paranoide/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Ectoparasitoses/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Esquizofrenia Paranoide/psicologia
5.
Diabet Med ; 24(11): 1290-5, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17956455

RESUMO

BACKGROUND: Patients with Type 2 diabetes and albuminuria are at high risk to progress to end-stage renal disease (ESRD). Although angiotensin receptor blockers confer renoprotection, many diabetic patients still develop overt nephropathy and reach ESRD. Glycosaminoglycans belong to the same family as heparin and heparinoids. Pilot studies with sulodexide, a glycosaminoglycan, have shown that sulodexide can reduce urinary albumin excretion rates in diabetic patients. No hard renal end-point data are available. METHODS: Two multicentre, double-masked, randomized placebo controlled trials were designed to study the renoprotective potential of sulodexide. The Sulodexide Microalbuminuria Trial examined the efficacy of sulodexide given over 26 weeks in 1000 patients with Type 2 diabetes, hypertension and microalbuminuria. The Sulodexide Overt Nephropathy Trial examined the efficacy of sulodexide in 2240 patients with Type 2 diabetes, hypertension and proteinuria > or = 900 mg/24 h. RESULTS: The primary outcome of The Sulodexide Microalbuminuria Trial was (i) conversion to normoalbuminuria and at least a 25% decrease in the urinary albumin creatinine ratio (UACR), or (ii) at least a 50% reduction in UACR. The primary outcome of The Sulodexide Overt Nephropathy Trial was time to a composite end point of doubling of serum creatinine or ESRD. CONCLUSIONS: The sulodexide nephropathy programme will document whether therapy with sulodexide confers renal protection in Type 2 diabetes and nephropathy.


Assuntos
Nefropatias Diabéticas/prevenção & controle , Glicosaminoglicanos/uso terapêutico , Hipertensão/complicações , Hipoglicemiantes/uso terapêutico , Falência Renal Crônica/prevenção & controle , Albuminúria/induzido quimicamente , Albuminúria/metabolismo , Nefropatias Diabéticas/tratamento farmacológico , Método Duplo-Cego , Feminino , Glicosaminoglicanos/metabolismo , Humanos , Hipoglicemiantes/metabolismo , Falência Renal Crônica/tratamento farmacológico , Masculino , Resultado do Tratamento
6.
Ann Oncol ; 15(2): 324-9, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14760129

RESUMO

BACKGROUND: The purpose of this study was to induce immunity to p53 by using an idiotypic vaccine, composed of a pool of eight peptides derived from the complimentarity determining regions (CDRs) of human anti-p53 antibodies. PATIENTS AND METHODS: Subjects with advanced malignancy received up to four, monthly intradermal injections of pooled peptides (500 microg of each) admixed with granulocyte-macrophage colony-stimulating factor (GM-CSF; 100 microg). In addition, two sheep and two rabbits were also vaccinated with the pooled peptides. RESULTS: Fourteen subjects were enrolled into the study and six of these completed the vaccination schedule. The vaccine was well tolerated by all subjects and no major adverse events were attributable to the vaccine. All subjects mounted in vivo delayed type hypersensitivity (DTH) responses to two or more of the individual vaccine peptides. Vaccine-induced antibodies specific for peptides 2, 5 or 8 were detected in four of six subjects, and two of these had vaccine-specific, cell-mediated responses. Increasing titers of p53-specific antibodies were found in one patient. No T-cell response to p53 was observed in any of the subjects. All animals developed humoral immunity to the peptides and one of the sheep developed rising serum titers of anti-p53 antibodies. CONCLUSIONS: Vaccination with human antibody CDR regions represents a novel method for inducing human antibodies, which may in turn serve as immunological mimics of p53.


Assuntos
Vacinas Anticâncer , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Proteína Supressora de Tumor p53/imunologia , Adulto , Idoso , Animais , Formação de Anticorpos , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/imunologia , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Humanos , Injeções Intradérmicas , Masculino , Pessoa de Meia-Idade , Coelhos , Ovinos , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia
7.
Sci Eng Ethics ; 9(1): 3-16, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12645225

RESUMO

This paper forms an introduction to this issue, the contents of which arose directly or indirectly from a conference in May 2001 on Corruption of scientific integrity?--The commercialisation of academic science. The introduction, in recent decades, of business culture and values into universities and research institutions is incompatible with the openness which scientific and all academic pursuit traditionally require. It has given rise to a web of problems over intellectual property and conflict of interest which has even led to corporate sponsors' suppressing unfavourable results of clinical trials, to the detriment of patients' health. Although there are those who see the norms of science developing to recognise the importance of instrumental science aiming at specific goals and of knowledge judged by its value in a context of application, none justifies the covert manipulation of results by vested interest. Public awareness of these problems is growing and creating a climate of opinion where they may be addressed. We suggest a way forward by the introduction of nationally and internationally-accepted guidelines for industrial collaboration which contain proper protections of the core purposes of universities and of the independence of their research. Some codes suggested for this purpose are discussed. We note that some universities are moving to adopt such codes of conduct, but argue the need for strong support from the government through its funding bodies.


Assuntos
Academias e Institutos/ética , Indústria Farmacêutica/ética , Ética em Pesquisa , Universidades/ética , Conflito de Interesses , Comportamento Cooperativo , Indústria Farmacêutica/organização & administração , Ética , Ética nos Negócios , Ética Institucional , Guias como Assunto , Propriedade Intelectual , Relações Interinstitucionais , Cultura Organizacional , Estados Unidos , Universidades/organização & administração
8.
J Clin Virol ; 22(3): 297-303, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11564595

RESUMO

BACKGROUND: Increases in sexual risk behaviour have recently been reported among homosexually active men in Australia and in other industrialised countries, potentially facilitating an increase in HIV incidence. OBJECTIVE: To monitor HIV incidence among homosexually active men seen through a network of sexual health clinics in Australia. STUDY DESIGN: Selected metropolitan public sexual health clinics provided counts of the number of people seen at the clinics during a calendar year, the number voluntarily tested for HIV antibody and the number newly diagnosed with HIV infection, broken down by sex, age group, HIV exposure category and HIV antibody testing history. HIV incidence was estimated among homosexually active men with a history of a negative test in the 12 months prior to last being seen in a calendar year. RESULTS: Of 23924 men seen at the clinics in 1993-1999 with a reported history of male homosexual contact, 7440 (31.1%) had a negative test in the 12 months prior to last being seen in a calendar year. The percentage of men with a recent negative test declined significantly over time, from more than 33% in 1994-1996 to 29% in 1999 (P=0.003), and with increasing age, from 34.3% among men aged 25-29 years to 27.4% among men aged 40 years or older (P<0.0005). A total of 5346 (71.9%) men were retested for HIV antibody within 12 months of the last negative test. The percentage of men retested declined significantly over time, from 77.8% in 1994 to 67.2% in 1999 (P=0.021) but did not change by age group (P=0.132). Overall, 56 men were newly diagnosed with HIV infection. Estimated HIV incidence was 2.1% in 1993-1999; incidence did not change significantly by year (P=0.498) or age group (P=0.757). CONCLUSION: HIV incidence has remained stable among homosexually active men seen through a network of sexual health clinics in Australia.


Assuntos
Infecções por HIV/epidemiologia , Adolescente , Adulto , Austrália/epidemiologia , Estudos de Coortes , Centros Comunitários de Saúde , Homossexualidade Masculina , Humanos , Incidência , Masculino , Fatores de Tempo
9.
AIDS Res Hum Retroviruses ; 17(3): 233-42, 2001 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-11177406

RESUMO

IL-12 production is reduced in HIV infection, and recombinant human IL-12 (rhIL-12) augments in vitro HIV-specific proliferative responses in PBMC from HIV-seropositive individuals. To determine whether rhIL12 could also augment HIV-specific CTL responses we studied 41 HIV-seropositive individuals. Recombinant hIL-12 increased the detectable in vitro HIV-specific CD8 CTL activity of PBMC taken from HIV-seropositive individuals with CD4 counts >500 cells/microl and from some individuals with lower CD4 counts. IL-12 increased cell recovery in cultures of PBMC from HIV-seropositive individuals with CD4 counts >500 cells/microl and also increased the precursor CTL frequency. However, the increase in HIV-specific CTL activity was not due to IL-2 or IFN-gamma production or an increase in the number of cells with surface markers characteristic of CTL effector cells. This study demonstrates that rhIL-12 augments in vitro HIV-specific CTL activity and provides evidence to justify further investigation within clinical trials of this cytokine in HIV infection.


Assuntos
Soropositividade para HIV/imunologia , HIV-1/imunologia , Interleucina-12/farmacologia , Proteínas Recombinantes/farmacologia , Linfócitos T Citotóxicos/imunologia , Adulto , Células Cultivadas , Feminino , Soronegatividade para HIV/imunologia , Humanos , Interleucina-12/genética , Interleucina-12/imunologia , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/imunologia , Linfócitos T Reguladores/imunologia
10.
Clin Cancer Res ; 6(12): 4674-83, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11156219

RESUMO

The murine antibody 30.6 recognizes an antigen that is expressed on a high proportion of colorectal carcinomas and their metastases. We report the results of single-dose escalation studies of the chimeric 30.6 (c30.6) monoclonal antibody in metastatic colorectal cancer, to evaluate its safety, pharmacokinetics, and biodistribution. Recombinant c30.6 (IgG1kappa) antibody was secreted from Chinese hamster ovary cells and purified by a multistep chromatography process. Seventeen patients with metastatic colorectal cancer were enrolled in this dose escalation study. The first four patients were treated with 3 mg of 123I-labeled c30.6, whereas the next 13 received a single dose of unlabeled antibody (maximum dose, 50 mg/m2). The most frequent side effect was a novel syndrome of severe burning and erythema of the face, chest, neck, ears, palms, soles, and genitalia. The frequency of this syndrome was markedly reduced in those patients premedicated with high doses of histamine receptor 1 and histamine receptor 2 blockers. Other side effects were mild and predictable. Biodistribution studies showed a rapid and intensive hepatic uptake. At the 50 mg/m2 level the half-life and maximum serum concentration were 81 +/- 15 h and 7.9 microg/ml, respectively. One patient developed a low-level human anti-c30.6 response. Tumor response was assessed by computed tomography, positron emission tomography scanning, and serial carcinoembryonic antigen measurements. There were no partial responses, although positron emission tomography scanning demonstrated some reduction in tumor activity in three individuals. The chimerized c30.6 antibody is not immunogenic in humans and appears worthy of further study. It does, however, produce a unique profile of side effects that can be well controlled with premedication.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/terapia , Adulto , Idoso , Animais , Anticorpos Monoclonais/efeitos adversos , Células CHO , Cromatografia , Cromatografia em Gel , Cricetinae , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Radioisótopos do Iodo/metabolismo , Fígado/efeitos dos fármacos , Masculino , Camundongos , Pessoa de Meia-Idade , Metástase Neoplásica , Fatores de Tempo , Tomografia Computadorizada de Emissão , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Resultado do Tratamento
11.
Clin Nephrol ; 52(3): 172-8, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10499313

RESUMO

AIM AND METHODS: We report increases in axial and appendicular bone density after parathyroidectomy in renal patients. Bone density was recorded pre-operatively and at 6 weeks, 6 months and 1 year post-operatively. We have previously reported that axial bone density increased dramatically at 6 weeks but that there were no early cohort increases at the appendicular skeleton [Stein et al. 1997]. RESULTS: We now report that at six months, bone density had continued to increase at the lumbar spine and femoral neck, with median respective 6 months increases over baseline of 1.3 (p < 0.01) and 0.7 (p < 0.01 ) Z-scores. Bone density then appeared to stabilize at the axial skeleton. At the appendicular skeleton increases were significant at the one year time point with median respective increases at the ultradistal radius and one third radius of 0.46 (p < 0.05) and 0.49 (p < 0.05) Z-scores. The different pattern of responses to parathyroidectomy between the axial and appendicular sites supports the concept that appendicular bone turnover is slower than axial bone turnover. Furthermore, at the appendicular skeleton, bone turnover appears similar between cortical and trabecular bone. CONCLUSION: In renal patients, bone density increases after parathyroidectomy at both the axial and appendicular skeleton. Axial increases are large and occur early. Appendicular increases occur at both cortical and trabecular sites but are slower than the axial changes.


Assuntos
Densidade Óssea , Paratireoidectomia , Absorciometria de Fóton , Remodelação Óssea , Estudos de Coortes , Feminino , Colo do Fêmur/diagnóstico por imagem , Seguimentos , Humanos , Falência Renal Crônica/terapia , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Diálise Peritoneal , Rádio (Anatomia)/diagnóstico por imagem , Diálise Renal , Fatores de Tempo
12.
Am J Kidney Dis ; 32(6): E3, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10074597

RESUMO

The Fanconi syndrome is a generalized disorder of proximal renal tubular transport characterized by wasting of phosphate, amino acids, glucose, bicarbonate, and uric acid. The association of the acquired Fanconi syndrome with lambda light-chain proteinuria is rare. We report the third case in the English language literature. A 65-year-old man presented with severe pelvic pain. Investigations showed an elevated serum creatinine level, and a 24-hour urine collection contained 2.56 g protein. The Fanconi syndrome was diagnosed, with findings of phosphaturia, glycosuria, and aminoaciduria. Bence Jones protein (lambda sub-type) was present in the urine at a concentration of 0.58 g/L. Monocytic cells in the bone marrow and proximal tubular cells in the kidney contained cytoplasmic crystalline inclusions. Undecalcified bone sections confirmed the clinical diagnosis of osteomalacia. The patient was treated with phosphate, calcium, and ergocalciferol and experienced significant symptomatic improvement. The Fanconi syndrome caused by light-chain deposition in proximal tubular cells is well described in the literature. However, it is rare for the light chains to be of the lambda subtype. This may reflect differences in the physicochemical properties of kappa and lambda light chains.


Assuntos
Síndrome de Fanconi/complicações , Cadeias lambda de Imunoglobulina/análise , Osteomalacia/etiologia , Idoso , Biópsia , Epitélio/ultraestrutura , Síndrome de Fanconi/imunologia , Síndrome de Fanconi/patologia , Humanos , Técnicas Imunoenzimáticas , Rim/patologia , Masculino , Osteomalacia/diagnóstico , Osteomalacia/terapia
13.
Clin Nephrol ; 48(3): 191-4, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9342492

RESUMO

We report dramatic increases in spine and hip bone mineral density six weeks following parathyroidectomy in renal patients. We have previously reported a cross-sectional association between parathyroidectomy and higher axial bone mineral density in dialysis patients. Large axial increases in bone mineral density after surgery for primary hyperparathyroidism have been recorded by others at one year postoperatively. Bone mineral density was recorded before and six weeks after parathyroidectomy. Scans were performed at the lumbar spine, hip and non-dominant radius. Values were expressed as Z-scores (standard deviations from the mean of an age- and gender-matched reference population). Large increases in lumbar were spine and femoral neck bone mineral density seen at six weeks post parathyroidectomy. Median increases were 0.57 (p = 0.006) and 0.26 (p = 0.039) Z-score units for these sites, respectively. Individual six-week increases were as large as 1.3 Z-score units at the spine and 1.0 Z-score units at the femoral neck. No significant cohort change was detected at the forearm but individual forearm changes were highly variable. Several mechanisms to explain these large rapid increases can be postulated. These include: mineralization of osteoid and/or contraction of the remodeling space. The changes illustrate the extent to which the skeleton is capable of rapid and profound change in mineral content. Our findings emphasize that the skeleton is a heterogeneous organ and that bone density should be measured at multiple skeletal sites.


Assuntos
Densidade Óssea , Paratireoidectomia , Absorciometria de Fóton , Distúrbio Mineral e Ósseo na Doença Renal Crônica/cirurgia , Feminino , Colo do Fêmur/diagnóstico por imagem , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Diálise Peritoneal , Rádio (Anatomia)/diagnóstico por imagem , Diálise Renal , Fatores de Tempo
15.
Am J Kidney Dis ; 28(4): 515-22, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8840940

RESUMO

Dialysis patients are at risk for low bone mineral density (BMD) consequent of hyperparathyroidism, 1,25-dihydroxyvitamin D deficiency, previous immunosuppression, chronic acidosis, secondary amenorrhea, and chronic heparin and aluminum exposure. We wanted to determine the prevalence and distribution of osteopenia and the influence of risk factors for osteopenia in dialysis patients. Dual energy x-ray absorptiometry was used to record BMD at the lumbar spine (LS), hip, and nondominant forearm. Results were expressed as Z-scores (standard deviations from the mean of a healthy age- and gender-matched reference population). Osteopenia was defined as a Z-score worse than -2. In the 250 dialysis patients studied, the prevalence of osteopenia at the LS, femoral neck (FN) and ultradistal radius (UD) was 8%, 13% and 20%, respectively. The median Z-scores at these sites were all significantly different from the healthy reference population median of 0 and were 0.29 (P = 0.008), -0.67 (P < 0.001), and -1.01 (P < 0.001), respectively. Previous transplantation was associated with as much as a one Z-score lower BMD at the FN (P = 0.0069) and UD (P = 0.0011) and a marginally significant reduction at the LS (P = 0.0777). Previous parathyroidectomy was associated with a markedly higher LS BMD (P = 0.0001) and a higher BMD at the FN (P = 0.0017) but not the UD (P = 0.3691). A history of secondary amenorrhea was associated with a lower FN BMD (P = 0.0047) but not a significantly lower BMD at the LS (P = 0.0978) or UD (P = 0.2327). In hemodialysis patients without a history of transplantation, parathyroidectomy, or secondary amenorrhea, there was no correlation between Z-score at any site and duration of dialysis. Thus, osteopenia in dialysis patients occurs in both axial and appendicular sites and sites of compact and cancellous bone. It is more common with previous transplantation and secondary amenorrhea, whereas a history of parathyroidectomy is associated with increased BMD. No relationship was found between BMD and duration of hemodialysis, which suggests that important changes in BMD occur during the predialysis stage of chronic renal failure.


Assuntos
Doenças Ósseas Metabólicas/etiologia , Diálise Peritoneal/efeitos adversos , Diálise Renal/efeitos adversos , Absorciometria de Fóton , Adulto , Idoso , Amenorreia/etiologia , Densidade Óssea , Doenças Ósseas Metabólicas/diagnóstico , Feminino , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Paratireoidectomia/efeitos adversos , Fatores de Risco , Fatores de Tempo
16.
Clin Nephrol ; 46(4): 225-9, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8905206

RESUMO

Between 1971 and 1991, 845 patients were diagnosed as having IgA glomerulonephritis on renal biopsy performed. These patients were followed for a mean period of 53 months post biopsy (range 0-336 months). By the end of follow up 147 (17%) of patients have developed chronic renal failure (Cr > 0.2 mmol/l) or end-stage renal failure. Presenting creatinine > 0.12 mmol/l, hypertension, nephrotic range, age > 40 years and male gender, all correlated strongly on univariate analysis with the development of chronic renal failure or kidney disease (all p < 0.0001). However, a number of patients developing chronic renal failure or end-stage renal failure already had renal impairment (creatinine > 0.12 mmol/l at presentation). A separate comparison was performed of patients presenting with creatinine < 0.12 mmol/l and either developing chronic failure or end-stage renal failure within 5 years of biopsy (n = 18) and those with creatinine still < 0.12 mmol/l after 5 years follow up (n = 186). Of the 18 patients who deteriorated 6 (35%) were nephrotic at presentation and 9 (56%) had focal hyalinosis and sclerosis on renal biopsy. This compared with 5 (3%) patients with nephrotic range proteinuria and 16 (10%) patients with focal hyalinosis and sclerosis among the 186 patients who did not deteriorate (p < 0.0001). The sensitivity and specificity of the presence of either or both factors in predicting deterioration was calculated at 65% and 87% respectively. Thus in patients with normal renal function at presentation the presence of nephrotic range or focal hyalinosis and sclerosis are strong predictors of adverse clinical outcome.


Assuntos
Glomerulonefrite por IGA/diagnóstico , Glomerulosclerose Segmentar e Focal/epidemiologia , Glomérulos Renais/patologia , Proteinúria/epidemiologia , Adulto , Biópsia , Estudos de Casos e Controles , Progressão da Doença , Feminino , Seguimentos , Glomerulonefrite por IGA/epidemiologia , Glomerulonefrite por IGA/urina , Glomerulosclerose Segmentar e Focal/patologia , Humanos , Falência Renal Crônica/epidemiologia , Masculino , Valor Preditivo dos Testes , Proteinúria/patologia , Fatores de Risco , Sensibilidade e Especificidade , Fatores de Tempo
18.
J Assist Reprod Genet ; 13(3): 254-8, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8852889

RESUMO

PURPOSE: Our purpose was to investigate early biochemical and ultrasonic measurements of pregnancies resulting from embryos biopsied for preimplantation diagnosis of inherited disease. RESULTS: Singleton pregnancies following biopsy had lower initial hCG levels [10 or 12 days after oocyte recovery (OR)], which rose steeply to match the controls by 16 days after OR. Twin biopsied pregnancies showed hCG levels lower than those of twin control pregnancies, which rose in parallel with the controls but remained lower for a longer period than the singletons. Progesterone levels showed a wide variation. Ultrasound measurements showed that overall the mean sac diameter and crown-rump length at 28 and 42 days after egg collection were similar in biopsied and control pregnancies. CONCLUSIONS: Pregnancies resulting from biopsied embryos behave similarly to control IVF pregnancies. However, the reduction in cell mass following embryo biopsy occasionally results in reduced levels of circulating serum hCG and smaller ultrasound measurements in early pregnancy.


Assuntos
Biópsia/efeitos adversos , Blastocisto/metabolismo , Fertilização in vitro , Doenças Genéticas Inatas/diagnóstico , Gonadotropina Coriônica/sangue , Transferência Embrionária , Feminino , Humanos , Gravidez , Progesterona/sangue , Ultrassonografia Pré-Natal
19.
Cell Signal ; 8(1): 67-73, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8777143

RESUMO

Extracellular ATP (0.1-100 microM) evoked a biphasic increase in cytosolic free Ca2+ ion concentration ([Ca2+]i) in fura-2 loaded undifferentiated HL-60 cells and activated the release of the lysosomal enzyme beta-glucuronidase. The EC50 for the elevation of [Ca2+]i was about 0.2 microM. However, the EC50 for the activation of beta-glucuronidase release was two orders of magnitude higher (about 20 microM). These data imply that the ATP-induced elevation in [Ca2+]i is not sufficient to provoke beta-glucuronidase release. The role of [Ca2+]i in ATP-induced beta-glucuronidase release was further investigated using Ca(2+)-free solutions and by loading HL-60 cells with the non-fluorescent Ca(2+)-chelator BAPTA-AM. Ca2+ ions from both intracellular and extracellular sources were necessary for the activation of beta-glucuronidase secretion by extracellular ATP. However, the internal store is the major source of Ca2+ ions for the response.


Assuntos
Trifosfato de Adenosina/farmacologia , Cálcio/fisiologia , Glucuronidase/metabolismo , Células HL-60/efeitos dos fármacos , Lisossomos/metabolismo , Transdução de Sinais/fisiologia , Diferenciação Celular , Quelantes/farmacologia , Grânulos Citoplasmáticos/enzimologia , Grânulos Citoplasmáticos/metabolismo , Citosol/metabolismo , Relação Dose-Resposta a Droga , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Proteínas de Ligação ao GTP/fisiologia , Humanos , Lisossomos/enzimologia , Proteínas de Neoplasias/metabolismo
20.
Cell Calcium ; 17(6): 399-408, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8521454

RESUMO

Arachidonate (1-300 microM) mobilized Ca2+ ions from an intracellular store and stimulated the entry of Ca2+ ions from the extracellular fluid in undifferentiated HL-60 cells that had been loaded with Fura-2. The integrated response was biphasic in form: arachidonate liberated Ca2+ ions from the intracellular store first, resulting in a transient increase in cytosolic free Ca2+ concentration ([Ca2+]i). Ca2+ entry from the extracellular fluid was not evident for a further 1-2 min. At baseline, [Ca2+]i was 48.1 +/- 14.0 nM (SEM, n = 5). Upon addition of arachidonate (100 microM), [Ca2+]i rose to a transient peak level of 217 +/- 38.6 nM (SEM, n = 5) and a later plateau level of 427 +/- 118 nM (SEM, n = 5). Removal of added Ca2+ ions from the extracellular fluid in the presence of EGTA (1.0 mM) had no effect on the initial transient response but abolished the second phase of the response. In HL-60 cells that had been loaded with BAPTA/AM, the initial transient phase of the response was abolished but the elevation in [Ca2+]i due to Ca2+ entry from the extracellular fluid was unaffected. Undifferentiated HL-60 cells also responded to arachidonate (100 microM) with an increase in the release of the lysosomal enzyme beta-glucuronidase. Arachidonate-induced beta-glucuronidase release from BAPTA-loaded cells or in control cells exposed to Ca(2+)-free solutions was inhibited by about 50%. In BAPTA-loaded cells that were incubated with Ca(2+)-free solutions, arachidonate-induced beta-glucuronidase release was inhibited by about 90%. Leukotriene B4 failed to elevate [Ca2+]i in the concentration range 0.01-1 microM and failed to activate beta-glucuronidase release in concentrations up to 10 microM. Furthermore, the cyclo-oxygenase/lipoxygenase inhibitor ETYA (100 microM) was without effect on secretion. Consistent with this finding, we found that a large number of unsaturated fatty acids could reproduce the effect of arachidonate on [Ca2+]i and beta-glucuronidase release. Fatty acids belonging to the omega-3, omega-6 and omega-7 unsaturated fatty acid families were effective in elevating [Ca2+]i and stimulating beta-glucuronidase release. However, three unsaturated fatty acids, all belonging to the omega-9 fatty acid family, were ineffective.


Assuntos
Cálcio/metabolismo , Ácidos Graxos/farmacologia , Glucuronidase/metabolismo , Ácido Araquidônico/metabolismo , Ácido Araquidônico/farmacologia , Cátions , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Ácidos Graxos/metabolismo , Fura-2 , Humanos , Leucemia Promielocítica Aguda/metabolismo , Leucemia Promielocítica Aguda/patologia , Células Tumorais Cultivadas
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