RESUMO
Coronary artery calcifications(CACs), are related to the increased cardiovascular mortality during kidney transplantation(KTx). Using coronary-CT performed at 1 month(T0) and 5 years(T5) after KTx we evaluated: (1) the prevalence of CACs; (2) the clinical and biochemical factors related to CACs; 3) the factors implicated with CACs progression. We evaluated 67-pts selected from the 103-pts transplanted in our unit between 2007 and 2008. Clinical and biochemical parameters were recorded at the time of pre-KTx evaluation and for five years after KTx. Coronary-CT for the Agatson score (AS) evaluation was performed at T0 and at T5, and CACs progression was determined. At baseline AS was 45 [0-233]. At T5 AS was 119 [1-413]. At T0, 69% of patients had CACs. Age and dialytic vintage were the main independent variables related to CACs. At T5, CACs were present in 76% of patients. Age was the only independent factor in determining CACs. A progression of CACs was observed in 74% of patients. They were older, had higher CACs-T0 and higher SBP throughout the 5-years. The presence of CACs at T0 and age were the only independent factors in determining the CACs-progression. CACs-T0 had the best discriminative power for CACs progression. CACs prevalence is quite high in KTx patients; Age is strictly related to CACs; Age and the presence of CACs at baseline were the two major factors associated with the progression of CACs during the five years of follow up. CACs-T0 had the best discriminative power for progression of CACs.
Assuntos
Doença da Artéria Coronariana/epidemiologia , Transplante de Rim/estatística & dados numéricos , Calcificação Vascular/epidemiologia , Adulto , Estudos de Coortes , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/patologia , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Calcificação Vascular/mortalidade , Calcificação Vascular/patologiaRESUMO
The Questionnaire of Cognitive Schema Activation in Sexual Context (QCSASC) is a validated and widespread used measure to assess the self-schemas elicited during sexual negative events in both men and women. The current study aimed to test the psychometric characteristics of the Italian version of the QCSASC in both heterosexual men and women. After linguistic translation, the psychometric properties (internal consistency, construct and discriminant validity) were evaluated in 1038 participants (435 men and 603 women, 767 healthy and 271 clinicals complaining of sexual problems). Confirmatory factor analyses showed a not satisfactory fit of the original factor structure of the QCSASC versions. Principal component analyses were performed highlighting two new factorial structures, further validated with CFAs ("Helpless" and "Unlovable"). Cronbach's alpha, composite reliability and average variance extracted were used as internal consistency measures. Moreover, the QCSASC showed a strong association with emotional response and sexual functioning, being able to differentiate between sexually clinical and control group. Current findings support the validity and the internal consistency of the QCSASC Italian version and allows to assess dysfunctional cognitive schemas activated when facing sexual problematic situations for both clinical and research purposes.
Assuntos
Cognição/fisiologia , Psicometria/métodos , Comportamento Sexual/psicologia , Disfunções Sexuais Psicogênicas/psicologia , Inquéritos e Questionários , Adolescente , Adulto , Idoso , Emoções , Feminino , Heterossexualidade , Homossexualidade , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Ereção Peniana , Análise de Componente Principal , Reprodutibilidade dos Testes , Adulto JovemRESUMO
Androgen deficiency syndrome is a commonly diagnosed condition. The aim of this study was to investigate common clinical practices of specialists in the field of sexual medicine regarding androgen replacement treatment for men and women. Attendees of the 16th Annual Congress of the European Society of Sexual Medicine held in January 2014 in Istanbul, Turkey, were asked to participate in a survey during the congress days. A 24-item self-report, closed-question questionnaire was distributed. Three sections were accessed: sociodemographic data, professional background and personal practice patterns regarding androgen substitution in men and women. A total of 133 physicians (mean age 47 years; range 25-79) completed the survey. Responses were inconsistent regarding the lab tests used for primary evaluation of male androgen deficiency. The majority of participants (62%) recommended testosterone replacement therapy for symptomatic men with testosterone levels <8 nmol l(-1) (231 ng dl(-1)). Similarly, most physicians (88%) recognized a correlation between libido and testosterone levels in women. Only 42% and 53% reported they would prescribe testosterone to women with low libido, premenopausal and postmenopausal, respectively. This survey showed discrepancies among physicians regarding testosterone replacement therapy for men and women.
Assuntos
Androgênios/uso terapêutico , Terapia de Reposição Hormonal/psicologia , Hipogonadismo/tratamento farmacológico , Disfunções Sexuais Fisiológicas/tratamento farmacológico , Testosterona/uso terapêutico , Adulto , Idoso , Atitude do Pessoal de Saúde , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores SexuaisRESUMO
Here we propose the optimization of a rapid and reproducible protocol for intracellular metabolite extraction from yeast cells and their metabolic profiling by (1)H-NMR spectroscopy. The protocol reliability has been validated through comparison between the metabolome of cells in different phases of growth or with different genetic backgrounds.
Assuntos
Metabolômica/métodos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Saccharomycetales/metabolismo , Metaboloma , Saccharomycetales/citologia , Saccharomycetales/crescimento & desenvolvimentoRESUMO
Central venous catheters are indispensable for the long-term treatment of seriously and chronically ill patients, but their use is often associated with a variety of complications; indeed, 90% of primary bloodstream infections are related to patients having a catheter. In studies performed in France, Germany and Italy, meticillin-resistant Staphylococcus aureus (MRSA) accounted for >50% of all S. aureus isolates obtained in catheter-related bloodstream infections (CRBSIs). These infections have a serious impact on long-term disability of the patient, a substantial additional financial burden for health systems, and high costs for patients. Decreasing the rate of CRBSIs requires a multidisciplinary approach, including behavioural and educational interventions and the insertion of the correct type of catheter. Although vancomycin remains the cornerstone of empirical therapy for CRBSIs caused by MRSA, combination of different antimicrobials and new approaches are indispensable to enhance the eradication of S. aureus biofilms and to manage the patient appropriately.
RESUMO
INTRODUCTION: In Europe, helplines have become a common counselling service for men and women who are seeking advice for sexual problems. Despite this, relatively few peer-reviewed reports on this subject have been published in the last decade. AIM: To investigate the range of sexual concerns reported by users of an Italian helpline and to describe the differences, if any, between male and female callers; to identify the overlap among sexual difficulties and the associations between the variables of the study. METHODS: The study included selected records of the calls received during the 3-year period between 2006 and 2008 (n = 944). Data were analysed using descriptive statistics and bivariate analysis. RESULTS: Users were more often male (62.2%), aged between 26 and 35 years, who had not sought any previous help. The most frequently reported male sexual difficulties were erectile dysfunction (ED) and premature ejaculation, while the majority of female callers reported vaginismus and orgasmic disorder (OD). We found an association between desire disorder (DD) and ED in men (41.7%), and between OD and DD in women (36.8%). CONCLUSIONS: Telephone counselling is an important and effective resource to elicit requests that otherwise might remain hidden; therefore, it can be a useful link between the health-care system and callers. This is true mainly for men. The next step could be to establish a quality management instrument to investigate whether users find the service helpful.
Assuntos
Aconselhamento , Linhas Diretas/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Disfunções Sexuais Fisiológicas/terapia , Disfunções Sexuais Psicogênicas/terapia , Adulto , Distribuição por Idade , Idoso , Feminino , Humanos , Itália , Libido , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
OBJECTIVE: This study investigates affective and sexual dimensions in partners involved as caregivers of Alzheimer dementia (AD) subjects. A negative correlation between burden of the caregiver and sexual-affective quality of life was assumed. DESIGN AND METHODS: Hundred participants with AD partner (33 male, 67 female), aged between 55 and 85 years were recruited and data were collected from the Caregiver Burden Inventory scale and a semi-structured interview that included demographic information, medical history, relationship and sexual satisfaction, and current sexual function. AD group was compared with a control group (CG) (N=100) matched for age, sex, education and marital status on measures of the semi-structured interview. Data were analysed using frequency count, univariate analysis (chi-squared and ANOVA) and bivariate correlation. RESULTS: The findings revealed that mean burden level was 31.59 (SD 19.51). A difference between experimental and CGs was found for sexual and affective marital satisfaction (p<0.05). The same variables showed a rather negative correlation with total burden levels (r=-0.374, p<0.001; r=-0.448, p<0.001).
Assuntos
Doença de Alzheimer/psicologia , Cuidadores/psicologia , Comportamento Sexual , Cônjuges/psicologia , Idoso , Idoso de 80 Anos ou mais , Efeitos Psicossociais da Doença , Feminino , Humanos , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Satisfação Pessoal , Psicometria , Qualidade de VidaRESUMO
Urinary incontinence (UI) is a very common disorder in women, involving severe consequences on the patients' perception of quality of life and sexuality. The aim of this contribution is to analyze the psycho-relational aspects linked to UI, focusing on sexual activity, self-perception of sexual competence and self-esteem. Urinary incontinence causes feelings of shame and inadequacy as well as low self-esteem; it may affect sexual activity, reducing sexual intercourse frequency. Many authors highlight a strong comorbidity between urinary incontinence and sexual dysfunctions, such as dyspareunia, vaginismus, hypo-active sexual desire, arousal and orgasm disorders. Literature analysis shows that changes in sexual activity are influenced not only by urinary incontinence symptoms but also by the disorder self-perception, by previous sexuality, menopause, social status and the partner's attitude. The etiological study of urinary incontinence shows that several different factors play a role in this disorder. Therefore, an integrated therapeutic approach is suggested, considering, besides the organic issues, the experience and feelings of patients as well as the consequences on their sexual and social life.
RESUMO
In addition to its AT1-receptor antagonist activity, losartan has been shown to antagonize thromboxane A2 (TXA2)-induced contraction of animal vessels. We investigated for the first time in human isolated gastroepiploic artery (GEA) and saphenous vein (SV) the TXA2/PGH2-receptor antagonist activity of losartan in the presence of indomethacin (1 microM) and N(omega)-nitro-L-arginine (100 microg). Losartan at concentrations of > or =1 microM on GEA and from 10 microM on SV significantly shifted U46619-induced contractions to the right. In addition, 100 microM losartan decreased by 34% the amplitude of the contraction to U46619 on both GEA and SV. The potency of losartan for the TXA2 receptor was 50- and 80-fold lower than that for the AT1 receptor on human GEA and SV, respectively. This inhibitory effect of losartan appeared selective for angiotensin II and TXA2-induced contractions because 100 microM losartan did not modify either endothelin-1- or KCl-induced contraction in human SV, although a reduction of norepinephrine- and 5-hydroxytryptamine-induced contraction was observed in human GEA and SV, respectively. In conclusion, losartan is an antagonist of TXA2 receptor on human GEA and SV. However, this antagonist activity occurred for a relative high dose of losartan, suggesting that it contributes at a low level, if any, to its antihypertensive effect.
Assuntos
Anti-Hipertensivos/farmacologia , Losartan/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Receptores de Tromboxanos/antagonistas & inibidores , Veia Safena/efeitos dos fármacos , Estômago/irrigação sanguínea , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Angiotensina II/farmacologia , Antagonistas de Receptores de Angiotensina , Inibidores de Ciclo-Oxigenase/farmacologia , Relação Dose-Resposta a Droga , Endotelina-1/farmacologia , Humanos , Técnicas In Vitro , Indometacina/farmacologia , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Nitroarginina/farmacologia , Norepinefrina/farmacologia , Cloreto de Potássio/farmacologia , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Prostaglandina/antagonistas & inibidores , Receptores de Tromboxano A2 e Prostaglandina H2 , Veia Safena/fisiologia , Serotonina/farmacologiaRESUMO
BACKGROUND: Osteoporosis is common in patients with Cushing's disease and is likely due to an imbalance between bone formation and resorption. Alendronate is an aminobisphosphonate that is able to increase bone mass mainly by inhibiting bone resorption. OBJECTIVE: We have evaluated the effect of chronic treatment with alendronate on bone mineral density (BMD) in patients with Cushing's disease. PATIENTS: 39 patients with Cushing's disease entered this study. 39 age-, sex- and BMI-matched normals served as controls for baseline evaluation. The 39 patients were divided into four groups: 1) 10 patients with active disease treated with alendronate and ketoconazole; 2) 11 patients with inactive disease treated with alendronate; 3) 8 patients with active disease treated with ketoconazole alone, 4) 10 patients with inactive disease received no treatment. TREATMENT PROTOCOL: Alendronate was given for 12 months in a dose of 10 mg orally once daily after fasting at 0800 h in the morning. Ketoconazole was given in a dose of 200-600 mg orally daily, when pituitary surgery was unsuccessful. STUDY DESIGN: Lumbar spine (L1-L4) and femoral neck BMD, serum osteocalcin (OC), urinary cross-linked N-telopeptides of type I collagen (Ntx) levels were evaluated at study entry, in patients and controls, and were repeated after 6 and 12 months in the 39 patients. RESULTS: BMD values were lower in patients with Cushing's disease than in controls at both L1-L4 (0.72 +/- 0.4 vs. 1.01 +/- 0.6 g/cm2, P < 0.05) and femoral neck (0.69 +/- 0.3 vs. 0.96 +/- 0.6 g/cm2, P < 0.05). In the 39 patients with Cushing's disease considered as a whole, serum OC levels were lower (1.1 +/- 0.1 vs 1.5 +/- 0.1 nmol/l, P < 0.01), while Ntx values were higher than in controls (168 +/- 25 vs. 61 +/- 31 nmol BCE/mmol creatinine, P < 0.01). In the alendronate-treated groups, serum OC levels increased, while Ntx levels significantly decreased after 6 and 12 months of treatment without any significant difference between the two groups. BMD values measured at L1-L4 and femoral neck significantly increased after 12 months of therapy. In patients of group 4, a significant increase of serum OC levels and a significant decrease of Ntx levels were observed together with a slight increase of BMD values after 12 months. No significant change in either biochemical markers or BMD values was found in patients of group 3. CONCLUSIONS: Patients with Cushing's disease have osteoporosis which needs to be rapidly reversed to limit the risk of fracture. The results of the present study show that a 12 month treatment period with alendronate induced an improvement in bone mineral density greater than in untreated patients.
Assuntos
Alendronato/uso terapêutico , Síndrome de Cushing/complicações , Osteoporose/tratamento farmacológico , Osteoporose/etiologia , Doença Aguda , Adulto , Antifúngicos/uso terapêutico , Biomarcadores/sangue , Densidade Óssea/efeitos dos fármacos , Colágeno/sangue , Colágeno Tipo I , Síndrome de Cushing/sangue , Quimioterapia Combinada , Feminino , Humanos , Cetoconazol/uso terapêutico , Masculino , Pessoa de Meia-Idade , Osteocalcina/sangue , Osteoporose/sangue , Peptídeos/sangue , Estudos ProspectivosRESUMO
The aim of the current study was to evaluate the effectiveness of a long-term treatment with sodium valproate in 19 patients with Cushing's disease. Before therapy beginning, the patients were subjected to acute test with 600 mg sodium valproate. Then, they were subjected to a 3-month therapy with sodium valproate at the dose of 600 mg/day before surgery (presurgical study). The 7 patients not surgically cured were subjected again to a 3-month therapy with sodium valproate at the dose of 600 mg/day after surgery (postsurgical study). Circulating ACTH and cortisol and urinary free cortisol levels were evaluated before and monthly after the beginning of the therapy. A decrease of plasma ACTH and serum cortisol levels greater than 50% of baseline was considered as positive response to acute test whereas the normalization of plasma ACTH, serum cortisol and urinary free cortisol levels and the clinical remission were considered as positive response to the long-term treatment. At acute test, 8 patients were considered responders and 11 patients non-responders. In no patient plasma ACTH, serum cortisol and urinary free cortisol were normalized during the long-term treatment. Urinary free cortisol levels significantly decreased (483.2 +/- 33.8 vs 699.4 +/- 67.0 micrograms/24 h), whereas plasma ACTH (302.8 +/- 17.7 vs 183.3 +/- 25.0 ng/l) and serum cortisol (466.5 +/- 23.2 vs 356.7 +/- 19.6 micrograms/l) significantly increased during sodium valproate administration in the 19 patients enrolled in the presurgical study. Plasma ACTH (247.7 +/- 22.3 vs 168.6 +/- 15.0 ng/l), serum cortisol (387.4 +/- 35.8 vs 282.0 +/- 16.0 micrograms/l) and urinary free cortisol (370.9 +/- 70.6 vs 261.3 +/- 37.8 micrograms/24 h) levels significantly increased in the 7 patients enrolled in the postsurgical study. No patient had clinical remission of Cushing's disease. In conclusion, the current study showed that long-term therapy with sodium valproate is not useful in the therapeutic management of Cushing's disease neither as alternative nor as adjunctive therapy to surgery.
Assuntos
Síndrome de Cushing/tratamento farmacológico , Falha de Tratamento , Ácido Valproico/uso terapêutico , Hormônio Adrenocorticotrópico/sangue , Adulto , Síndrome de Cushing/metabolismo , Feminino , Humanos , Hidrocortisona/sangue , Hidrocortisona/urina , Masculino , Pessoa de Meia-Idade , Ácido Valproico/administração & dosagemRESUMO
BACKGROUND: Higher vasopressin (AVP) levels have been found in the inferior petrosal sinus ipsilateral to the ACTH-secreting adenoma than in the contralateral one, suggesting a potential pathogenetic role of AVP in Cushing's disease. DESIGN: In order to investigate AVP release, plasma ACTH and AVP concentrations were assayed in the inferior petrosal sinuses and in the peripheral blood before and after CRH stimulation. PATIENTS: Twenty patients with Cushing's disease and 12 with other pituitary diseases were subjected to simultaneous and bilateral inferior petrosal sinus sampling for diagnostic purposes. Ten healthy sex and age-matched subjects served as control for peripheral AVP values. MEASUREMENTS: Plasma ACTH concentrations were measured by RIA using commercial kits. Plasma AVP concentrations were assayed by RIA in acetone extracts of 1-2 ml plasma. RESULTS: Plasma AVP levels in the inferior petrosal sinuses were significantly higher in Cushing's disease than in patients with other pituitary diseases (P < 0.05) and in both groups AVP levels were higher in the inferior petrosal sinuses than in the peripheral blood (P < 0.01). In Cushing's disease, ACTH, but not AVP levels, were higher in the inferior petrosal sinus ipsilateral to the adenoma than in the contralateral one (P < 0.01). Seven patients showed a significant ACTH and AVP increase (greater than 50% of baseline) after CRH stimulation in the inferior petrosal sinus ipsilateral to the adenoma. Conversely, no change was found in AVP levels in the remaining 13 patients. When AVP values were analyzed in relation to surgical cure, higher inferior petrosal sinus levels (P < 0.05) were found in 6 patients with poor outcome: 4 of these patients had significantly decreased plasma AVP concentrations (by 32-43% of baseline) after CRH bolus. Peripheral AVP levels were similar in healthy subjects and patients with Cushing's disease whereas they were significantly reduced in patients with other pituitary diseases (P < 0.002). CONCLUSIONS: The results of this study show that patients with Cushing's disease and poor surgical outcome had the highest AVP levels in our series. CRH administration caused different effects on AVP levels: it increased them in 35% of patients whereas there was no response in the remaining patients. On the basis of these findings, it is hypothesized that AVP might be involved in the persistence of ACTH hypersecretion in a subset of patients poorly responsive to surgery.
Assuntos
Hormônio Adrenocorticotrópico/sangue , Arginina Vasopressina/sangue , Hormônio Liberador da Corticotropina , Síndrome de Cushing/diagnóstico , Amostragem do Seio Petroso , Adenoma/diagnóstico , Adenoma/cirurgia , Adolescente , Adulto , Síndrome de Cushing/sangue , Síndrome de Cushing/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças da Hipófise/sangue , Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/cirurgia , RadioimunoensaioRESUMO
The effect of corticotropin (ACTH)-releasing hormone (CRH) administration on alpha-melanocyte-stimulating hormone (alpha-MSH), ACTH and beta-endorphin (beta-EPH) was evaluated in the inferior petrosal sinuses and in the periphery of 30 patients affected with Cushing's disease subjected to simultaneous and bilateral inferior petrosal sinus sampling for diagnostic purposes. Baseline PRL levels, sensitivity to dexamethasone and surgery outcome were compared to alpha-MSH response. CRH bolus did not modify alpha-MSH concentrations either in the inferior petrosal sinuses or in the periphery in the 30 patients considered as a whole. In 7 of 30 patients, however, a greater than 50% increase over baseline alpha-MSH levels (from 50 to 115.5%) was recorded in the inferior petrosal sinus ipsilateral to the adenoma (from 42.9 +/- 1.7 to 76.4 +/- 4.6 ng/l; p < 0.001), whereas no change was found in the contralateral inferior petrosal sinus or in the periphery. Conversely, as expected, ACTH and beta-ELI significantly increased in all the patients after CRH both in the inferior petrosal sinuses and in the periphery (particularly in the inferior petrosal sinus ipsilateral to the adenoma). No difference in sensitivity to dexamethasone (urinary cortisol percent decrease: 66.4 +/- 4.9 vs. 67.8 +/- 3.4) and surgery outcome (chi 2 test: p = 0.7) was found between patients with alpha-MSH response to CRH and patients without such a response. By contrast, baseline PRL levels, although being normal in both groups, were significantly higher in patients with alpha-MSH response to CRH (18.1 +/- 1.6 vs. 10.1 +/- 0.7 micrograms/l; p < 0.001). In conclusion, the results of the present study suggest that in a subset of patients with Cushing's disease (23.3% of our series) alpha-MSH may be released after the administration of CRH together with ACTH and beta-EPH by adenomatous corticotrophs. In this subset of patients, PRL levels may be in the upper normal range.
Assuntos
Hormônio Liberador da Corticotropina/administração & dosagem , Síndrome de Cushing/metabolismo , Amostragem do Seio Petroso , alfa-MSH/metabolismo , Adolescente , Hormônio Adrenocorticotrópico/sangue , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prolactina/sangue , beta-Endorfina/sangueAssuntos
Antinematódeos/efeitos adversos , Doenças do Sistema Nervoso/induzido quimicamente , Piperazinas/efeitos adversos , Diálise Renal/efeitos adversos , Overdose de Drogas , Eletroencefalografia , Feminino , Hemoperfusão/métodos , Humanos , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/diagnóstico , PiperazinaRESUMO
Twenty-six consecutive patients with ACTH-dependent Cushing syndrome were subjected to simultaneous, bilateral inferior petrosal sinus sampling for ACTH assay before and after ACTH-releasing hormone (CRH) stimulation. The baseline ACTH inferior petrosal sinus/periphery (IPS/P) ratio was > or = 2 in 12 of 26 patients (46%), whereas the CRH-stimulated IPS/P ratio was > or = 3 in 19 of 26 patients (73%). A pituitary adenoma, ACTH-secreting at immunostaining, was surgically proved in all of the 19 patients who had an ACTH IPS/P ratio > or = 2 basally or > or = 3 after the CRH test but also in three other patients who did not have such ratios. The value of the basal IPS/P ratio and the complete lack of ACTH increase after CRH led to the diagnosis of an ectopic ACTH syndrome in four patients: a bronchial carcinoid was found in three patients, and the site of the tumor was still unknown in the other. In conclusion, the CRH test improved the diagnostic accuracy of inferior petrosal sinus sampling from 61.5% (12 pituitary, 4 ectopic) to 92.0% (19 pituitary, 4 ectopic). Thus it should be performed during the diagnostic process.
Assuntos
Hormônio Adrenocorticotrópico/sangue , Hormônio Liberador da Corticotropina , Síndrome de Cushing/diagnóstico , Amostragem do Seio Petroso , Síndrome de ACTH Ectópico/diagnóstico , Síndrome de ACTH Ectópico/patologia , Síndrome de ACTH Ectópico/cirurgia , Adenoma/diagnóstico , Adenoma/patologia , Adenoma/cirurgia , Adulto , Síndrome de Cushing/patologia , Síndrome de Cushing/cirurgia , Diagnóstico Diferencial , Feminino , Humanos , Hipofisectomia , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/patologia , Neoplasias Hipofisárias/cirurgiaRESUMO
Signals controlling the insulin receptor endocytotic pathway have been investigated using the R1152Q insulin receptor mutant (M). This mutant receptor exhibits high levels of insulin-independent kinase activity, impaired autophosphorylation, and lack of an insulin stimulatory effect on both auto- and substrate phosphorylation. NIH-3T3 fibroblasts expressing M receptors displayed a 2.5-fold higher 125I-insulin internalization rate than wild type (WT) but lacked insulin-induced receptor internalization and down-regulation. Cell surface recycling of internalized receptors also occurred at a higher rate in M cells and was unaffected by insulin. Cell preincubation with 35 mM Tris, which inhibits the insulin receptor degradative route, elicited no effect on M receptor recycling but inhibited that of WT by 40%. In contrast, the energy depleter 2,4-dinitrophenol, which inhibits normal insulin receptor retroendocytosis, impaired M receptor recycling 4-fold more effectively than that of WT. The release of internalized intact 125I-insulin was 6-fold greater in M than in WT fibroblasts and was almost completely inhibited by dinitrophenol, whereas insulin degradation by M cells was 4-fold decreased as compared with WT. Thus, internalization and recycling of the constitutively active Gln1152 receptor kinase occur in the absence of autophosphorylation. However, tyrosine phosphorylation appears to be required for proper sorting of endocytosed insulin receptors.
Assuntos
Endocitose , Mutação , Receptores Proteína Tirosina Quinases/metabolismo , Receptor de Insulina/metabolismo , 2,4-Dinitrofenol , Células 3T3 , Animais , Arginina/genética , Dinitrofenóis/farmacologia , Regulação para Baixo , Endocitose/efeitos dos fármacos , Glutamina/genética , Insulina/metabolismo , Camundongos , Fosforilação , Receptores Proteína Tirosina Quinases/genética , Receptor de Insulina/genética , Transdução de Sinais , Transfecção , Trometamina/farmacologiaRESUMO
In 29 consecutive patients with adrenocorticotropin (ACTH)-dependent Cushing's syndrome, we compared the usefulness of multiple baseline ACTH evaluations (10/29), multiple hormone evaluation (29/29) and ACTH-releasing hormone (CRH) stimulation (21/29) during simultaneous and bilateral inferior petrosal sinus sampling. The basal inferior petrosal sinus/periphery ratio for ACTH concentrations was greater than 2 in 18 of the 29 patients and CRH challenge caused the appearance of an inferior petrosal sinus/periphery ratio greater than 3 in 6 other patients. The presence of an ACTH-secreting adenoma was surgically proven in all the 24 patients who had an ACTH inferior petrosal sinus/periphery ratio greater than 2 basally or greater than 3 after the CRH test but also in 1 patient who had an inferior petrosal sinus/periphery ratio lower than 2 basally or 3 after the CRH test. In 4 patients, both the very high peripheral ACTH levels, the inferior petrosal sinus/periphery ratio and the complete lack of ACTH increase after CRH indicated the presence of an ectopic ACTH syndrome: a bronchial carcinoid was found in 2 patients, whereas the site of the tumor is still unknown in the remaining 2. An ACTH intersinus gradient greater than 1.4 was found in 23 patients. Among these 23 patients, the side of the adenoma was correctly predicted in 19 patients and wrongly in 4.(ABSTRACT TRUNCATED AT 250 WORDS)