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1.
J Klin Endokrinol Stoffwechs ; 15(1): 5-27, 2022.
Artigo em Alemão | MEDLINE | ID: mdl-35251520

RESUMO

A central goal of the adrenal insufficiency management is the prevention of acute adrenal insufficiency (also known as adrenal crisis or Addison crisis). This consensus document was generated in order to achieve better implementation and harmonization of measures for the prevention and treatment of acute adrenal insufficiency in Austria. The following measures are generally recommended for all patients with adrenal insufficiency and are outlined in this manuscript: (1) Provision of a "steroid emergency card" and possibly also a medical alert bracelet or necklace (or similar identification). (2) Provision of a hydrocortisone injection kit (or alternative glucocorticoid preparations) for emergency use plus sufficient oral glucocorticoid doses for stress situations/illness. (3) Education of patients and relatives on glucocorticoid stress dosing and "sick day rules" as well as on self-injection of hydrocortisone. (4) Provision of a treatment guideline (information leaflet) for the prevention and therapy of the adrenal crisis, which should also be shown to healthcare staff if necessary. (5) Provision of an emergency phone number (contact details) of the responsible endocrine specialist team or other trained staff. (6) Reinforcement of patient education on a regular basis (preferably yearly). This consensus document also includes recommendations for glucocorticoid dosing in the perioperative setting as well as in various other stress situations.

2.
Eur Thyroid J ; 9(2): 106-112, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32257960

RESUMO

INTRODUCTION: The main differential diagnoses of secondary hyperthyroidism include thyrotropin-secreting neuroendocrine pituitary tumors (TSH-PitNETs) and resistance to thyroid hormone. As a rare cause of secondary hyperthyroidism, ectopic thyrotropin-producing neuroendocrine pituitary tumors must also be considered. CASE PRESENTATION: A 48-year-old female patient with overt hyperthyroidism and elevated thyrotropin was admitted to the endocrine outpatient clinic of a secondary care hospital in March 2018. The patient had an inconspicuous pituitary MRI and F18-F-DOPA PET-CT, but showed a tumor mass located at the pharyngeal roof. Most biochemical tests and an increased tracer uptake of the pharyngeal mass in a Ga68-DOTANOC PET-CT argued for the presence of an ectopic TSH-PitNET. After treatment with octreotide over 5 days and a consecutive normalization of free thyroxine and free triiodothyronine, the tumor was endoscopically resected. Histologically, the mass consisted of small partially spindle, partially polygonal monomorphic to mildly pleomorphic cells with immunoreactivity for thyrotropin and luteinizing hormone. Postoperatively, the patient required intermittent levothyroxine therapy. DISCUSSION AND CONCLUSIONS: Ectopic TSH-PitNETs represent an extremely rare cause for secondary hyperthyroidism. While the diagnostic process may be complicated by negative imaging studies of the pituitary gland, family history, biochemical tests, and functional imaging using gallium-labelled somatostatin analogues may be helpful in establishing the diagnosis.

3.
Wien Med Wochenschr ; 170(1-2): 6-14, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30725443

RESUMO

The present "Good Clinical Practice Recommendations" relate to radiofrequency ablation (RFA) training, execution, and quality control, as well as to pre- and postinterventional standards of care. They are aimed at all physicians who intend to learn to perform, or who are already conducting RFA interventions as well as at thyroid specialists providing pre- and postoperative care to RFA patients in Austria. Adoption of these recommendations is strongly encouraged by the afore-listed professional associations.All RFA interventionists who adhere to these standards shall be listed on a homepage linked to these professional associations entitled "RFA centers in compliance with the GCP recommendations of the ÖSDG/OGNMB/ÖGES/OEGCH-ACE." This will ensure harmonization of RFA training and quality control in the performance of the treatment in Austria.


Assuntos
Ablação por Cateter , Medicina Nuclear , Nódulo da Glândula Tireoide , Áustria , Humanos , Imagem Molecular , Nódulo da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/cirurgia
4.
J Endocr Soc ; 3(9): 1748-1758, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31528833

RESUMO

CONTEXT: The aldosterone-to-active renin ratio (AARR) is the recommended screening test for primary aldosteronism (PA), but prospective study data on its sensitivity and specificity are sparse. OBJECTIVE: To investigate the diagnostic accuracy of the AARR for detecting PA. DESIGN: Prospective diagnostic accuracy study. SETTING: This study was conducted from February 2009 to August 2015 at the outpatient clinic of the Department of Endocrinology and Diabetology of the Medical University of Graz, Austria. PARTICIPANTS: Four hundred patients with arterial hypertension who were referred to a tertiary care center for screening for endocrine hypertension. INTERVENTION: Participants had a determination of the AARR (index test) and a second AARR determination followed by a saline infusion test (SIT) after 2 to 6 weeks. PA was diagnosed in individuals with any AARR ≥3.7 ng/dL/µU/mL [including a plasma aldosterone concentration (PAC) of ≥9 ng/dL] who had a PAC ≥10 ng/dL after the SIT. We did not substantially alter antihypertensive drug intake. MAIN OUTCOME MEASURES: Primary outcome was the receiver-operating characteristic (ROC) curve of the AARR in diagnosing PA. RESULTS: A total of 382 participants were eligible for analyses; PA was diagnosed in 18 (4.7%) patients. The area under the ROC curve of the AARR in detecting PA was 0.973 (95% CI, 0.956 to 0.990). Sensitivity and specificity for a positive AARR in diagnosing PA were 100% (95% CI, 81.5% to 100.0%) and 89.6% (95% CI, 86.0% to 92.5%), respectively. CONCLUSIONS: The AARR has good diagnostic accuracy for detecting PA.

5.
BMJ Open ; 7(9): e018242, 2017 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-28951417

RESUMO

OBJECTIVE: Oral anticoagulation (OAC) is state-of-the-art therapy for atrial fibrillation (AF), the most common arrhythmia worldwide. However, little is known about the perception of patients with AF and how it correlates with risk scores used by their physicians. Therefore, we correlated patients' estimates of their own stroke and bleeding risk with the objectively predicted individual risk using CHA2DS2-VASc and HAS-BLED scores. DESIGN: Cross-sectional prevalence study using convenience sampling and telephone follow-up. SETTINGS: Eight hospital departments and one general practitioner in Austria. Patients' perception of stroke and bleeding risk was opposed to commonly used risk scoring. PARTICIPANTS: Patients with newly diagnosed AF and indication for anticoagulation. MAIN OUTCOME MEASURES: Comparison of subjective risk perception with CHA2DS2-VASc and HAS-BLED scores showing possible discrepancies between subjective and objective risk estimation. Patients' judgement of their own knowledge on AF and education were also correlated with accuracy of subjective risk appraisal. RESULTS: Ninety-one patients (age 73±11 years, 45% female) were included in this study. Subjective stroke and bleeding risk estimation did not correlate with risk scores (ρ=0.08 and ρ=0.17). The majority of patients (57%) underestimated the individual stroke risk. Patients feared stroke more than bleeding (67% vs 10%). There was no relationship between accurate perception of stroke and bleeding risks and education level. However, we found a correlation between the patients' judgement of their own knowledge of AF and correct assessment of individual stroke risk (ρ=0.24, p=0.02). During follow-up, patients experienced the following events: death (n=5), stroke (n=2), bleeding (n=1). OAC discontinuation rate despite indication was 3%. CONCLUSIONS: In this cross-sectional analysis of OAC-naive patients with AF, we found major differences between patients' perceptions and physicians' assessments of risks and benefits of OAC. To ensure shared decision-making and informed consent, more attention should be given to evidence-based and useful communication strategies. TRIAL REGISTRATION NUMBER: NCT03061123.


Assuntos
Anticoagulantes/uso terapêutico , Fibrilação Atrial/complicações , Fibrilação Atrial/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/tratamento farmacológico , Estudos Transversais , Escolaridade , Feminino , Hemorragia/induzido quimicamente , Humanos , Julgamento , Masculino , Pessoa de Meia-Idade , Percepção , Medição de Risco , Acidente Vascular Cerebral/etiologia , Inquéritos e Questionários
6.
Int J Med Microbiol ; 306(4): 206-11, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27134190

RESUMO

OBJECTIVES: We determined primary and secondary resistance rates of H. pylori in different regions of Austria and potential bacterial and host factors associated with resistance. METHODS: In a prospective multicentre study H. pylori was cultivated from biopsies and susceptibility testing was performed according to EUCAST. Resistance to clarithromycin and levofloxacin was determined by sequencing of the resistance-determining regions of 23S rRNA and gyrA genes. cagA, vacA and babA2 genotypes were determined. RESULTS: A total of 1266 patients were included. 178 isolates were cultured: 128 from patients without prior eradication therapy, 50 from patients after failed eradication. Primary resistance to clarithromycin, levofloxacin and metronidazole were 17.2%, 9.4% and 10.2%, respectively. Secondary resistance to clarithromycin, levofloxacin and metronidazole were 64%, 18% and 44%, respectively. Prior eradication was associated with a higher risk of clarithromycin as well as metronidazole resistance (OR=8.1; 95% CI 3.8-17.1 and OR 5.7; 95% CI 2.5-13, respectively). CONCLUSION: Primary resistance to both clarithromycin and levofloxacin was markedly lower in Southern Austria than recently reported.


Assuntos
Farmacorresistência Bacteriana , Infecções por Helicobacter/microbiologia , Helicobacter pylori/efeitos dos fármacos , Adulto , Idoso , Antibacterianos/farmacologia , Áustria/epidemiologia , Claritromicina/farmacologia , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Feminino , Genótipo , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Humanos , Levofloxacino/farmacologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , RNA Ribossômico 23S/genética , Análise de Sequência de DNA , Fatores de Virulência/genética
7.
Wien Klin Wochenschr ; 124(21-22): 756-62, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23129485

RESUMO

OBJECTIVES: A retrospective study was conducted on an unselected sample of patients on vitamin K antagonists (VKAs; phenprocoumon, acenocoumarol) in an outpatient setting in Austria. The main objective was to determine whether bleeding and thromboembolic events reported in randomised trials are comparable to the experience in clinical practice. In addition, we focused on differences between the two VKAs and the particular indications for treatment and influences of risk factors. PARTICIPANTS: Total observation time was 10 years, the number of patients was 599 and the patient years-at-risk (pyr) was 1,856. RESULTS: Severe bleeding occurred in 1.1 % pyr and the bleeding-related mortality was 0.1 %. Severe thromboembolic events occurred in 2.8 % pyr, with a rate of fatal events of 0.3 %. A significant increase in risk was found in patients older than 75 years concerning bleeding as well as thromboembolic events. Acenocoumarol showed significantly higher rates in life-threatening and fatal bleeding episodes in comparison to phenprocoumon. CONCLUSIONS: The outcome of patients receiving VKA in an office setting is similar to that reported in the literature and the use of VKAs in this setting appears to be safe.


Assuntos
Assistência Ambulatorial/estatística & dados numéricos , Cumarínicos/uso terapêutico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Hemorragia/epidemiologia , Padrões de Prática Médica/estatística & dados numéricos , Tromboembolia/epidemiologia , Tromboembolia/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/uso terapêutico , Áustria/epidemiologia , Comorbidade , Feminino , Humanos , Incidência , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
8.
N Engl J Med ; 366(23): 2189-97, 2012 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-22551107

RESUMO

BACKGROUND: Adrenocortical carcinoma is a rare cancer that has a poor response to cytotoxic treatment. METHODS: We randomly assigned 304 patients with advanced adrenocortical carcinoma to receive mitotane plus either a combination of etoposide (100 mg per square meter of body-surface area on days 2 to 4), doxorubicin (40 mg per square meter on day 1), and cisplatin (40 mg per square meter on days 3 and 4) (EDP) every 4 weeks or streptozocin (streptozotocin) (1 g on days 1 to 5 in cycle 1; 2 g on day 1 in subsequent cycles) every 3 weeks. Patients with disease progression received the alternative regimen as second-line therapy. The primary end point was overall survival. RESULTS: For first-line therapy, patients in the EDP-mitotane group had a significantly higher response rate than those in the streptozocin-mitotane group (23.2% vs. 9.2%, P<0.001) and longer median progression-free survival (5.0 months vs. 2.1 months; hazard ratio, 0.55; 95% confidence interval [CI], 0.43 to 0.69; P<0.001); there was no significant between-group difference in overall survival (14.8 months and 12.0 months, respectively; hazard ratio, 0.79; 95% CI, 0.61 to 1.02; P=0.07). Among the 185 patients who received the alternative regimen as second-line therapy, the median duration of progression-free survival was 5.6 months in the EDP-mitotane group and 2.2 months in the streptozocin-mitotane group. Patients who did not receive the alternative second-line therapy had better overall survival with first-line EDP plus mitotane (17.1 month) than with streptozocin plus mitotane (4.7 months). Rates of serious adverse events did not differ significantly between treatments. CONCLUSIONS: Rates of response and progression-free survival were significantly better with EDP plus mitotane than with streptozocin plus mitotane as first-line therapy, with similar rates of toxic events, although there was no significant difference in overall survival. (Funded by the Swedish Research Council and others; FIRM-ACT ClinicalTrials.gov number, NCT00094497.).


Assuntos
Neoplasias do Córtex Suprarrenal/tratamento farmacológico , Carcinoma Adrenocortical/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mitotano/administração & dosagem , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Cisplatino/administração & dosagem , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Humanos , Análise de Intenção de Tratamento , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Mitotano/efeitos adversos , Qualidade de Vida , Estreptozocina/administração & dosagem , Estreptozocina/efeitos adversos , Adulto Jovem
10.
Am J Med Genet A ; 152A(7): 1752-5, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20583150

RESUMO

Pheochromocytomas are rare tumors of the adrenal gland occurring sporadically or as part of familial cancer syndromes. Here we report on the case of a pheochromocytoma due to the germline missense mutation c.491A>G (Q164R) in exon 3 of the von Hippel-Lindau gene in a girl as young as 2.75 years. Extended analyses of her relatives showed that the mutation occurred de novo in the patient's father who was subsequently diagnosed with bilateral pheochromocytomas and a retinal angioma. To the best of our knowledge, this is the youngest patient presenting with pheochromocytoma so far described in the literature. The same VHL mutation has been reported in a patient who developed a pheochromocytoma at the age of 10 years; therefore, for known VHL Q164R mutation carriers, we suggest screening for pheochromocytoma beginning at 2 years of age.


Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Mutação em Linhagem Germinativa/genética , Feocromocitoma/genética , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Neoplasias das Glândulas Suprarrenais/patologia , Sequência de Bases , Pré-Escolar , Análise Mutacional de DNA , Feminino , Humanos , Dados de Sequência Molecular , Feocromocitoma/patologia
11.
BMC Endocr Disord ; 9: 11, 2009 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-19351411

RESUMO

BACKGROUND: Primary aldosteronism (PA) affects approximately 5 to 10% of all patients with arterial hypertension and is associated with an excess rate of cardiovascular complications that can be significantly reduced by a targeted treatment. There exists a general consensus that the aldosterone to renin ratio should be used as a screening tool but valid data about the accuracy of the aldosterone to renin ratio in screening for PA are sparse. In the Graz endocrine causes of hypertension (GECOH) study we aim to prospectively evaluate diagnostic procedures for PA. METHODS AND DESIGN: In this single center, diagnostic accuracy study we will enrol 400 patients that are routinely referred to our tertiary care center for screening for endocrine hypertension. We will determine the aldosterone to active renin ratio (AARR) as a screening test. In addition, all study participants will have a second determination of the AARR and will undergo a saline infusion test (SIT) as a confirmatory test. PA will be diagnosed in patients with at least one AARR of >or= 5.7 ng/dL/ng/L (including an aldosterone concentration of >or= 9 ng/dL) who have an aldosterone level of >or= 10 ng/dL after the saline infusion test. As a primary outcome we will calculate the receiver operating characteristic curve of the AARR in diagnosing PA. Secondary outcomes include the test characteristics of the saline infusion test involving a comparison with 24 hours urine aldosterone levels and the accuracy of the aldosterone to renin activity ratio in diagnosing PA. In addition we will evaluate whether the use of beta-blockers significantly alters the accuracy of the AARR and we will validate our laboratory methods for aldosterone and renin. CONCLUSION: Screening for PA with subsequent targeted treatment is of great potential benefit for hypertensive patients. In the GECOH study we will evaluate a standardised procedure for screening and diagnosing of this disease.

12.
J Biol Chem ; 280(16): 15700-8, 2005 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-15691835

RESUMO

Shh (Sonic hedgehog) regulates gastric epithelial cell differentiation. We reported that incubation of purified canine parietal cells with epidermal growth factor (EGF) for 6-16 h, stimulates H(+)/K(+)-ATPase alpha-subunit gene expression through the activation of Akt. We explored if Shh mediates some of the actions of EGF in the parietal cells. EGF induced a 6-fold increase in Shh expression, measured by Western blots, after 5 h of incubation. This effect was inhibited by both the phosphatidylinositol 3-kinase inhibitor LY294002 and by transduction of the cells with an adenoviral vector expressing dominant negative Akt. EGF stimulated the release of Shh-like immunoreactivity from the parietal cells, after 16 h of incubation. Shh induced H(+)/K(+)-ATPase alpha-subunit gene expression, assessed by Northern blots, it stimulated a luciferase reporter plasmid containing the EGF-responsive sequence (ERE) of the canine H(+)/K(+)-ATPase alpha-subunit gene promoter, and it induced parietal cell nuclear protein binding to the ERE. Gli transcription factors mediate the intracellular actions of Shh. Co-transfection of the parietal cells with the H(+)/K(+)-luc plasmid together with one expressing Gli2, induced H(+)/K(+)-luciferase activity 5-fold, whereas co-transfection of the cells with the H(+)/K(+)-luc plasmid together with one expressing dominant negative Gli2, inhibited EGF induction of H(+)/K(+)-luciferase activity. Identical results were observed in the presence of the Shh signal transduction pathway inhibitor, cyclopamine. Transfection of the cells with dominant negative Akt inhibited EGF, but not Shh stimulation of H(+)/K(+)-ATPase-luciferase activity. Thus, EGF but not Shh signals through Akt. Preincubation of the cells for 16 h with either Shh or EGF enhanced histamine-stimulated [(14)C]aminopyrine uptake by 50%. In conclusions, some of the actions of EGF in the parietal cells are mediated by the sequential activation of the Akt and the Shh signal transduction pathways. These effects might represent novel mechanisms mediating the actions of growth factors on gastric epithelial cell differentiation.


Assuntos
Células Parietais Gástricas/metabolismo , Transdução de Sinais/fisiologia , Transativadores/metabolismo , Animais , Cães , Fator de Crescimento Epidérmico/metabolismo , Genes Reporter , ATPase Trocadora de Hidrogênio-Potássio/metabolismo , Proteínas Hedgehog , Proteínas Oncogênicas/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Fatores de Transcrição/metabolismo , Proteína GLI1 em Dedos de Zinco
13.
Gastroenterology ; 127(4): 1150-61, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15480993

RESUMO

BACKGROUND & AIMS: Incubation of purified (>95%) canine parietal cells in primary culture with epidermal growth factor for 7-16 hours stimulates H(+)K(+)-adenosine triphosphatase gene expression. In this study, we examined the effect of prolonged stimulation (72 hours) of the parietal cells with epidermal growth factor. METHODS: H(+)K(+)-adenosine triphosphatase protein and gene expression were assessed by immunohistochemistry and Northern blots. Mitogen-activated protein kinase and Akt activation were quantitated by kinase assays and Western blots with specific antiphospho antibodies. Akt overexpression was achieved by adenovirus-mediated gene transfer of a constitutively active Akt gene. RESULTS: Epidermal growth factor changed the morphology of the cultured cells, which acquired the appearance of fusiform cells, and it inhibited H(+)K(+)-adenosine triphosphatase gene expression. Staining of the cells both with anti-H(+)K(+)-adenosine triphosphatase antibodies and with Texas Red-labeled Dolichos biflorus lectin confirmed that the fusiform cells expressed markers of parietal cell differentiation. Epidermal growth factor stimulated mitogen-activated protein kinase with 2 peaks of activation, observed after 5 minutes and 72 hours, whereas it activated Akt after 5 minutes but not 72 hours of incubation. Overexpression of Akt blocked both epidermal growth factor-induced morphological transformation and inhibition of H + K + -adenosine triphosphatase gene expression. Identical results were observed in the presence of the mitogen-activated protein kinase inhibitor PD98059. CONCLUSIONS: Activation of the Akt signal-transduction pathway seems to be a crucial event for the induction of parietal cell maturation and differentiation.


Assuntos
Fator de Crescimento Epidérmico/farmacologia , Sistema de Sinalização das MAP Quinases/fisiologia , Células Parietais Gástricas/citologia , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Transdução de Sinais/fisiologia , Animais , Diferenciação Celular , Células Cultivadas , Cães , ATPase Trocadora de Hidrogênio-Potássio/genética , Subunidades Proteicas , Proteínas Proto-Oncogênicas c-akt
14.
Biochem Biophys Res Commun ; 323(1): 44-8, 2004 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-15351698

RESUMO

We previously reported that gastrin (G17) inhibits apoptosis of AR4-2J pancreatic adenocarcinoma cells, through the activation of Akt. We dissected the mechanisms responsible for this effect. D2, a CCKB receptor antagonist, inhibited G17 induction of Akt phosphorylation, measured by Western blots with anti-phospho-Akt antibodies. The intracellular calcium chelator BAPTA-AM, but not the PKC inhibitor GF109203X, blocked G17 induction of Akt. G17 stimulated BAD phosphorylation, measured by both Western blots with anti-phospho-BAD antibodies and by in vitro Akt kinase assays using recombinant BAD as substrate. G17 also induced FOXO3 phosphorylation assessed by Western blots with anti-phospho-FOXO3 antibodies, and BAPTA-AM inhibited this effect. Gastrin inhibited luciferase activity in cells transfected with FOXO1 together with a vector containing insulin-responsive sequences upstream of the luciferase reporter gene. In conclusion, G17 induces Akt through activation of CCKB receptors and of intracellular calcium-dependent, PKC-independent, pathways. This effect leads to BAD phosphorylation and to forkhead transcription factors inactivation.


Assuntos
Apoptose , Ácido Egtázico/análogos & derivados , Gastrinas/biossíntese , Gastrinas/fisiologia , Animais , Western Blotting , Cálcio/metabolismo , Proteínas de Transporte/metabolismo , Linhagem Celular , Quelantes/farmacologia , Proteínas de Ligação a DNA/metabolismo , Ácido Egtázico/farmacologia , Inibidores Enzimáticos/farmacologia , Fatores de Transcrição Forkhead , Gastrinas/metabolismo , Genes Reporter , Vetores Genéticos , Imunoprecipitação , Indóis/farmacologia , Luciferases/metabolismo , Maleimidas/farmacologia , Proteínas do Tecido Nervoso , Fosforilação , Plasmídeos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ratos , Proteínas Recombinantes/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Transfecção , Proteína de Morte Celular Associada a bcl
15.
Am J Physiol Gastrointest Liver Physiol ; 287(3): G715-25, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15331357

RESUMO

G17 has growth promoting and antiapoptotic effects on the AR4-2J pancreatic acinar cell line. We previously reported that whereas MAPK regulates G17-stimulation of AR4-2J cell proliferation, Akt mediates the antiapoptotic action of G17. We examined the signal-transduction pathways mediating G17 stimulation of AR4-2J cell growth and survival. G17 activated the small GTP binding proteins Ras, Rac, Rho, and Cdc42. Transduction of the cells with adenoviral vectors expressing dominant negative Akt, Ras, Rho, and Cdc42 but not dominant negative Rac inhibited AR4-2J cell proliferation and survival. Both exoenzyme C3 from Clostridium botulinum (C3), a toxin known to inactivate Rho, and PD98059, a MAPK inhibitor, reversed G17 inhibition of AR4-2J cell apoptosis. G17 induction of Akt activation was reduced by >60% by both dominant negative Ras and Rho and by 30% by dominant negative Cdc42. In contrast, G17-stimulated MAPK activation was blocked by >80% by dominant negative Ras but not by dominant negative Rho and Cdc42. Similar results were observed in the presence of C3. Dominant negative Rac failed to affect G17 induction of both Akt and MAPK, whereas it inhibited sorbitol by almost 50% but not G17-stimulated activation of p38 kinase. Thus G17 promotes AR4-2J cell growth and survival through the activation of multiple GTP binding proteins, which, in turn, regulate different protein kinase cascades. Whereas Ras activates Akt and MAPK, Rho and Cdc42 appear to regulate Akt and possibly other as yet unidentified kinases mediating the growth-stimulatory actions of G17.


Assuntos
Apoptose/fisiologia , Proteínas de Ligação ao GTP/fisiologia , Gastrinas/fisiologia , Substâncias de Crescimento/fisiologia , Adenosina Difosfato Ribose/metabolismo , Adenoviridae/genética , Adenoviridae/fisiologia , Animais , Western Blotting , Divisão Celular/fisiologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Ativação Enzimática/fisiologia , GTP Fosfo-Hidrolases/metabolismo , Proteínas de Homeodomínio/fisiologia , Marcação In Situ das Extremidades Cortadas , Proteína Quinase 1 Ativada por Mitógeno/fisiologia , Plasmídeos/genética , Proteínas Proto-Oncogênicas/fisiologia , Ratos , Timidina/metabolismo , Proteína cdc42 de Ligação ao GTP/fisiologia , Proteínas rac de Ligação ao GTP/fisiologia , Proteínas ras/fisiologia , Proteínas rho de Ligação ao GTP/fisiologia
16.
J Bone Miner Res ; 19(1): 42-7, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14753735

RESUMO

UNLABELLED: Evidence that genetic disposition for adult lactose intolerance significantly affects calcium intake, bone density, and fractures in postmenopausal women is presented. PCR-based genotyping of lactase gene polymorphisms may complement diagnostic procedures to identify persons at risk for both lactose malabsorption and osteoporosis. INTRODUCTION: Lactase deficiency is a common autosomal recessive condition resulting in decreased intestinal lactose degradation. A -13910 T/C dimorphism (LCT) near the lactase phlorizin hydrolase gene, reported to be strongly associated with adult lactase nonpersistence, may have an impact on calcium supply, bone density, and osteoporotic fractures in the elderly. MATERIALS AND METHODS: We determined LCT genotypes TT, TC, and CC in 258 postmenopausal women using a polymerase chain reaction-based assay. Genotypes were related to milk intolerance, nutritional calcium intake, intestinal calcium absorption, bone mineral density (BMD), and nonvertebral fractures. RESULTS: Twenty-four percent of all women were found to have CC genotypes and genetic lactase deficiency. Age-adjusted BMD at the hip in CC genotypes and at the spine in CC and TC genotypes was reduced by -7% to -11% depending on the site measured (p = 0.04). LCT(T/C-13910) polymorphisms alone accounted for 2-4% of BMD in a multiple regression model. Bone fracture incidence was significantly associated with CC genotypes (p = 0.001). Milk calcium intake was significantly lower (-55%, p = 0.004) and aversion to milk consumption was significantly higher (+166%, p = 0.01) in women with the CC genotype, but there were no differences in overall dietary calcium intake or in intestinal calcium absorption test values. CONCLUSION: The LCT(T/C-13910) polymorphism is associated with subjective milk intolerance, reduced milk calcium intake, and reduced BMD at the hip and the lumbar spine and may predispose to bone fractures. Genetic testing for lactase deficiency may complement indirect methods in the detection of individuals at risk for both lactose malabsorption and osteoporosis.


Assuntos
Densidade Óssea , Dieta , Fraturas Ósseas/complicações , Predisposição Genética para Doença/genética , Intolerância à Lactose/genética , Fatores Etários , Idoso , Animais , Calcifediol/sangue , Cálcio da Dieta/administração & dosagem , Cálcio da Dieta/metabolismo , Colágeno/sangue , Feminino , Colo do Fêmur/química , Frequência do Gene , Genótipo , Humanos , Absorção Intestinal , Lactase-Florizina Hidrolase/genética , Intolerância à Lactose/complicações , Vértebras Lombares/química , Pessoa de Meia-Idade , Leite , Osteocalcina/sangue , Ossos Pélvicos/química , Fragmentos de Peptídeos/sangue , Polimorfismo Genético/genética , Pós-Menopausa/sangue , Pós-Menopausa/genética , Pós-Menopausa/metabolismo , Análise de Regressão , Iogurte
17.
Am J Physiol Gastrointest Liver Physiol ; 282(5): G766-75, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11960773

RESUMO

Gastrin requires extensive posttranslational processing for full biological activity. It is presumed that progastrin is cleaved at pairs of basic amino acids by a prohormone convertase to form a glycine-extended intermediate (G-Gly) that serves as a substrate for peptidyl-glycine alpha-amidating monooxygenase (PAM), resulting in COOH-terminally amidated gastrin. To confirm the nature of progastrin processing in a primary cell line, we performed [(35)S]methionine-labeled pulse-chase biosynthetic experiments in canine antral G cells. Radiolabeled progastrin reached a peak earlier than observed for G-Gly or amidated gastrin. G-Gly radioactivity accumulated in G cells and preceded the appearance of radioactivity in amidated gastrin. The conversion of G-Gly to amidated gastrin was enhanced by the PAM cofactor ascorbic acid. To determine whether one member of the prohormone convertase family (PC2) was responsible for progastrin cleavage, G cells were incubated with PC2 antisense oligonucleotide probes. Cells treated with antisense probes had reduced PC2 expression, an accumulation of radiolabeled progastrin, and a delay in the formation of amidated gastrin. Progastrin in antral G cells is cleaved via PC2 to form G-Gly that is converted to amidated gastrin via the actions of PAM.


Assuntos
Gastrinas/biossíntese , Gastrinas/metabolismo , Antro Pilórico/enzimologia , Animais , Células Cultivadas , Cães , Regulação Enzimológica da Expressão Gênica , Glicina/metabolismo , Metionina/farmacocinética , Oxigenases de Função Mista/metabolismo , Complexos Multienzimáticos/metabolismo , Oligonucleotídeos Antissenso/farmacologia , Pró-Proteína Convertase 2 , Antro Pilórico/citologia , Subtilisinas/genética , Subtilisinas/metabolismo , Radioisótopos de Enxofre
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