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Biomedical subjects

G Lombardi

Publications and source records attributed to G Lombardi.

At least 163 records · Page 9Linked to original sources
PubMed2000

Cardiac effect of thyrotoxicosis in acromegaly.

Cardiac structure and function are affected both by acromegaly and hyperthyroidism. Whereas the former is mainly characterized by ventricular hypertrophy as well as diastolic and systolic impairment, the latter frequently leads to increased heart rate and enhancement of contractility and cardiac output. To further investigate this issue, we designed this two-arm study. In the first cross-sectional study, we compared echocardiography and radionuclide angiography results obtained in eight hyperthyroid acromegalic patients, eight hyperthyroid nonacromegalic patients, and eight healthy subjects. All acromegalic patients were receiving treatment for acromegaly at the onset of hyperthyroidism. In the second longitudinal study, performed in the group of acromegalic patients, we compared the cardiovascular results obtained during hyperthyroidism with the retrospective data obtained at the initial diagnosis of acromegaly and after 1-yr treatment for this disease and those prospective data obtained during the remission of hyperthyroidism. In the cross-sectional study, hyperthyroid acromegalic patients showed an increase in the left ventricular (LV) mass index (LVMi) compared to healthy and hyperthyroid controls (P < 0.05), with evidence of LVMi hypertrophy in five of them (62.5%). A significant correlation was found between LVMi and GH levels (r = 0.785; P < 0.05). The LV ejection fraction (LVEF) at rest was higher in the control hyperthyroid population than in healthy controls (P < 0.05), whereas the LVEF response to exercise was reduced in acromegalic patients (P < 0.05 vs. healthy controls). In acromegalics, the exercise-induced change in LVEF was significantly reduced compared to that in healthy controls (P < 0.001), but not to that in hyperthyroid controls (P < 0.07), being abnormal (<5% increase vs. baseline values) in six patients. Four of these six patients (66%) had elevated GH and insulin-like growth factor I levels during the treatment of acromegaly. An inverse correlation between GH and LVEF at rest (r = -0.896;P < 0.05) and at peak exercise (r = -0.950; P < 0.001) was recorded. The peak filling rate was reduced in hyperthyroid acromegalic patients compared to those in both control populations (P < 0.05). In the longitudinal study, acromegalic patients showed an increased LVMi during hyperthyroidism compared to that observed after successful treatment of acromegaly (P < 0.05); resting LVEF was increased compared to both basal (P < 0.001) and posttreatment values (P < 0.05). However, the exercise-induced change in LVEF was reduced (P < 0.05 vs. previous follow-up values). Remission of hyperthyroidism led to significant reduction of LVMi (P < 0.05) and resting LVEF (P < 0.05) and an increase in exercise-induced LVEF (P < 0.05). In light of these findings, hyperthyroidism produces a detrimental effect on the cardiovascular system of acromegalic patients, particularly in those with uncontrolled disease. Thus, control of GH and insulin-like growth factor I should be a major objective, as cardiovascular risk persists in patients with ineffective hormonal suppression, and constant endocrine and cardiovascular surveillance remain crucial steps in patient follow-up.

Acromegaly↗
PubMed2000

Subclinical Cushing's syndrome in patients with adrenal incidentaloma: clinical and biochemical features.

Incidentally discovered adrenal masses are mostly benign, asymptomatic lesions, often arbitrarily considered as nonfunctioning tumors. Recent studies, however, have reported increasing evidence that subtle cortisol production and abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis are more frequent than previously thought. The purpose of this study was to investigate the clinical and hormonal features of patients with incidentally discovered adrenal adenomas, in relation to their clinical outcome. Fifty consecutive patients with incidentally detected adrenal adenomas, selected from a total of 65 cases of adrenal incidentalomas, were prospectively evaluated. All of them underwent abdominal computed tomography scan and hormonal assays of the HPA axis function: circadian rhythm of plasma cortisol and ACTH, urinary cortisol excretion, 17-hydroxyprogesterone, androgens, corticotropin stimulation test and low-dose (2 mg) dexamethasone test. The patients were reevaluated at regular intervals (6, 12, and 24 months) for a median period of 38 months. Subtle hypercortisolism, defined as abnormal response to at least 2 standard tests of the HPA axis function in the absence of clinical signs of Cushing's syndrome (CS), was defined as subclinical CS. Mild-to-severe hypertension was found in 24 of 50 (48%) patients, type-2 diabetes in 12 of 50 (24%), and glucose intolerance in 6 of 50 (12%) patients. Moreover, 18 of 50 patients (36%) were diffusely obese (body mass index, determined as weight/height2, > 25), and 14 patients (28%) had serum lipid concentration abnormalities (cholesterol > or = 6.21 mmol/L, low-density lipoprotein cholesterol > or = 4.14 mmol/L and/or triglycerides > or = 1.8 mmol/L). Compared with a healthy population, bone mineral density Z-score, determined by the DEXA technique, tended to be slightly (but not significantly) lower in patients with adrenal adenoma (-0.41 SD). Endocrine data were compared with 107 sex- and age-matched controls, and patients with adenomas were found to have heterogeneous hormonal abnormalities. In particular, significantly higher serum cortisol values (P < 0.001), lower ACTH concentration (P < 0.05), and impaired cortisol suppression by dexamethasone (P < 0.001) were observed. Moreover, in patients with adenomas, cortisol, 17-OH progesterone, and androstenedione responses to corticotropin were significantly increased (P < 0.001, all), whereas dehydroepiandrosterone sulfate levels were significantly lower at baseline, with blunted response to corticotropin (P < 0.001, both). However, the criteria for subclinical CS were met by 12 of 50 (24%) patients. Of these, 6 (50%) were diffusely obese, 11 (91.6%) had mild-to-severe hypertension, 5 (41.6%) had type-2 diabetes mellitus, and 6 (50%) had abnormal serum lipids. The clinical and hormonal features improved in all patients treated by adrenalectomy, but seemed unchanged in all those who did not undergo surgery (follow-up, 9 to 73 months), except for one, who was previously found as having nonfunctioning adenoma and then revealed to have subclinical CS. In conclusion, an unexpectedly high prevalence of subtle autonomous cortisol secretion, associated with high occurrence of hypertension, diabetes mellitus, elevated lipids, and diffuse obesity, was found in incidentally discovered adrenal adenomas. Although the pathological entity of a subclinical hypercortisolism state remained mostly stable in time during follow-up, hypertension, metabolic disorders, and hormonal abnormalities improved in all patients treated by adrenalectomy. These findings support the hypothesis that clinically silent hypercortisolism is probably not completely asymptomatic.

17-alpha-Hydroxyprogesterone↗
PubMed2000

Macroprolactinoma shrinkage during cabergoline treatment is greater in naive patients than in patients pretreated with other dopamine agonists: a prospective study in 110 patients.

To investigate whether previous treatment with bromocriptine (BRC) or quinagolide (CV) impairs a subsequent response to long-term cabergoline (CAB) treatment, we prospectively studied 110 patients with macroprolactinoma. Four groups of patients were considered: 1) naive: 26 untreated patients with a mean serum PRL levels of 1013.4 +/- 277.7 microg/L (+/- SEM; range, 185.5-5611 microg/L); 2) intolerant: 19 patients previously shown to be intolerant of BRC treatment with a mean serum PRL level of 539.4 +/- 172.2 microg/L (range, 174-3564 microg/L); 3) resistant: 37 patients shown to be resistant/hyporesponsive to BRC, CV, or both, with a mean serum PRL level of 602.6 +/- 136.8 microg/L (range, 148-3511 microg/L); and 4) responsive: 28 patients previously treated with BRC or CV for 1-5 yr, achieving normoprolactinemia and restoration of gonadal function, but no longer treated with BRC or CV because of poor compliance or because the drug was not available. After a 15- to 30-day washout period, the serum PRL level was 397 +/- 43.1 microg/L (140-978 microg/L). CAB treatment was given at doses ranging 0.25-3.5 mg weekly for 1 yr to 110 patients, for 2 yr to 104 patients, and for 3 yr to 81 patients. Magnetic resonance imaging was performed before and after 12, 24, and 36 months of CAB treatment to evaluate significant tumor shrinkage (>80% reduction of pretreatment tumor volume). Among the 26 naive patients, normoprolactinemia was achieved in 21 (80.8%) after 1-6 months at 0.25-2 mg/week and in 5 patients after 24 months at 0.5-3 mg/week. Tumor volume was reduced from 1431.5 +/- 310.3 to 47.2 +/- 21.5 mm3 (P < 0.0001); average tumor shrinkage was 92.1 +/- 2.9%; significant tumor shrinkage was observed in 92.3% of patients, and tumor mass completely disappeared in 16 patients (61.5%). Among the 19 intolerant patients, normoprolactinemia was achieved in 18 (94.7%) after 1-6 months of CAB treatment at 0.25-1 mg/week. One patient remained mildly hyperprolactinemic. Tumor volume was reduced from 1925 +/- 423.1 to 842.0 +/- 330.7 mm3 (P < 0.001); average tumor shrinkage was 66.2 +/- 6.4%; significant tumor shrinkage was obtained in 42.1% of patients, and tumor mass completely disappeared in 4 patients (21%). Among the 37 resistant patients, normoprolactinemia was achieved in 19 (51.3%) after 6-12 months at 1-2 mg/week and in the remaining 18 patients after 18-24 months at 3-3.5 mg/week. Tumor volume was reduced from 1208.0 +/- 173.7 to 471.2 +/- 87.3 mm3 (P < 0.005); average tumor shrinkage was 58.4 +/- 4.9%; significant tumor shrinkage was obtained in 10 of 33 patients (30.3%), and in no patient did tumor mass completely disappear. Among the 28 responsive patients, normoprolactinemia was achieved in 23 (82.1%) after 1-6 months at 1-2 mg/week and in 5 patients after 12 months at 3 mg/week. Tumor volume was reduced from 1351.3 +/- 181.5 to 757.1 +/- 193.6 mm3 (P < 0.01); average tumor shrinkage was 59.2 +/- 6.2%; significant tumor shrinkage was obtained in 10 of 26 patients (38.4%), and tumor mass completely disappeared in 4 patients (15.4%). Nadir PRL levels and percent tumor shrinkage during CAB treatment in naive patients were significantly lower (P < 0.001) and higher (P < 0.001), respectively, than those in the remaining three groups, and the average weekly dose of CAB in resistant patients was significantly higher (P < 0.001) than that in the remaining three groups. A significant association was found between tumor shrinkage and previous treatments (chi2 = 27.1; P < 0.0001). At the multistep correlation analysis, nadir PRL levels were the strongest predictors of tumor shrinkage (r2 = 0.556; P < 0.0001), followed by CAB dose (r2 = 0.577; P < 0.0001). The tolerability was excellent in 105 patients (95.4%). In conclusion, the prevalence of macroprolactinoma shrinkage after CAB treatment at standard doses for 1-3 yr was higher in naive patients (92.3%) than in intolerant (42.1%), resistant (30.3%), and responsive patients (38.4%). Thus, C

Adolescent↗
PubMed2000

Cardiovascular effects of depot long-acting somatostatin analog Sandostatin LAR in acromegaly.

Cardiovascular disease is the most severe complication of acromegaly accounting for the increased mortality of these patients. Recently, the slow-release form of octreotide (OCT; Sandostatin LAR, OCT-LAR), for im injection every 28 days, was reported to induce suppression of GH levels below 7.5 mU/L (2.5 microg/L) in 39-75% of patients, and normalization of insulin-like growth factor (IGF)-I levels for age in 64-88% of patients, with an excellent patients' compliance. The aim of the present study was to investigate the early effect of OCT-LAR treatment on the left ventricular (LV) structure and performance in 15 somatostatin analog-naive patients with acromegaly (GH, 94.8 +/- 24.9 mU/L; IGF-I, 757.9 +/- 66.6 microg/L), focusing on the early effect of GH and IGF-I suppression on the heart. Cardiac structure was investigated by echocardiography, whereas LV performance was investigated by gated-blood-pool scintigraphy, before and after 3 and 6 months of treatment with OCT-LAR. OCT-LAR was initially administered im, at a dose of 20 mg every 28 days, for 3 months. In six patients, the dose was then increased to 30 mg every 28 days to achieve disease control, which was considered when fasting and/or glucose-suppressed GH values were below 7.5 and 3.0 mU/L, respectively, together with IGF-I values within the normal range for age. The treatment with OCT-LAR for 6 months induced a significant decrease of GH (to 12.9 +/- 3.0 mU/L) and IGF-I levels (to 340.3 +/- 40.2 microg/L) in all 15 patients. After 6 months of treatment, the percent IGF-I suppression was 52.8 +/- 4.4%, and serum GH/IGF-I levels were normalized in 9 patients. A significant decrease of LV mass index (LVMi), interventricular septum thickness, and LV posterior wall thickness was observed in all 15 patients after 3 and 6 months of OCT-LAR treatment: LVMi was decreased by 19.1 +/- 2.0% without any difference in patients with (19.9 +/- 2.7%) or without disease control (17.8 +/- 3.3%). Among the 11 patients with LV hypertrophy, 6 normalized their LVMi after treatment. At study entry, an inadequate LV ejection fraction (LVEF) at rest (<50%) was found in 5 patients (33.3%), whereas an impaired response of LVEF at peak exercise (<5% increase of basal value) was found in 9 patients (60%). A significant increase in LVEF, both at rest (from 51.6 +/- 2.6 to 58.1 +/- 1.7%, P < 0.01) and at peak exercise (from 51.6 +/- 2.3 to 60.2 +/- 2.4%, P < 0.001) was found in patients with (as compared with those without) disease control (from 55.2 +/- 3.8 to 58.0 +/- 4% and from 61.8 +/- 4.6 to 61.8 +/- 3.4%, respectively). Among the 5 patients with inadequate LVEF at rest, all but 1 regained a normal LVEF after 6 months of treatment; whereas, among the 9 patients with an impaired response of the LVEF at peak exercise, 3 patients normalized, 4 improved, and 2 impaired their responses after treatment. The percent of IGF-I suppression was significantly correlated with the percent increase of resting LVEF (r = 0.644, P < 0.01). Exercise duration (from 6.0 +/- 0.7 to 7.3 +/- 0.7 min) and capacity (from 69.0 +/- 8.2 to 80 +/- 7.8 watts) were increased in the 15 patients considered as a whole, but the improvement in the exercise response was significant only in patients with disease control (P < 0.01 and P < 0.05, respectively) who also had an increase in the peak ejection rate (P = 0.03). No change in hemodynamic parameters, either at rest or at peak exercise, was found after treatment with OCT-LAR in the 15 patients. In conclusion, the results of the present study demonstrate that OCT-LAR im injections every 28 days induces a sustained suppression of GH levels and IGF-I levels in all acromegalic patients, allowing achievement of disease control in 60% of patients after 6 months of treatment. The sustained suppression of IGF-I levels was followed by a significant reduction of LVMi in all patients already after 3 months of treatment, with recovery of LV hypertrophy in 6 of 11 patients. (ABSTRACT TRUN

Acromegaly↗
PubMed2000

Muscle sympathetic nerve activity in patients with acromegaly.

Muscle sympathetic nerve activity was measured in nine acromegalic patients (age, 35 +/- 4 yr; body mass index, 28 +/- 2 kg/m2) and eight healthy subjects (age, 32 +/- 3 yr; body mass index, 25 +/- 2 kg/m2) by combining the forearm arterial-venous difference technique with the tracer method [infusion of tritiated norepinephrine (NE)]. Muscle NE release was quantified both at rest and during physiological hyperinsulinemia while maintaining euglycemia (approximately 90 mg/dL) by means of the euglycemic clamp. Arterial plasma NE was similar in the two groups at rest (197 +/- 28 and 200 +/- 27 pg/mL (-1) and slightly increased during insulin infusion. Forearm NE release was 2.33 +/- 0.55 ng x liter(-1) x min(-1) in healthy subjects and 2.67 +/- 0.61 ng x liter(-1) x min(-1) in acromegalic subjects in the basal state and increased to a similar extent during insulin infusion in both groups (3.13 +/- 0.71 and 3.32 +/- 0.75 ng x L(-1) x min(-1), P < 0.05 vs. basal), indicating a normal stimulatory effect of insulin on muscle sympathetic activity. In contrast, insulin-stimulated forearm glucose uptake was markedly lower in acromegalic patients (2.3 +/- 0.4 mg x L(-1) x min(-1)) than in control subjects (7.9 +/- 1.3 mg x L(-1) x min(-1), P < 0.001), indicating the presence of severe insulin resistance involving glucose metabolism. Our data demonstrate that patients with long-term acromegaly have normal sympathetic activity in the skeletal muscle in the basal, postabsorptive state and normal increments in NE spillover in response to the sympatho-excitatory effect of insulin. Thus, the presence of severe insulin resistance in acromegaly is not accounted for by adrenergic mechanisms.

Acromegaly↗
PubMed2000

Cabergoline.

Cabergoline (CAB) (1-[(6-allelylergolin-8 beta-yl)carbonyl]-1-[3-(dimethylamino)propyl]-3-ethyl-urea) is an ergoline derivative with potent, selective and long-lasting inhibitory activity on prolactin (PRL) secretion acting on dopamine receptors present in pituitary lactotrophes. Receptor binding studies have demonstrated that CAB has high in vitro selectivity and affinity for the subtype D2 of the dopamine receptor. In cultures of rat anterior pituitary cells, the concentrations of CAB and bromocriptine required to inhibit PRL secretory activity by 50% (IC50) were 0.1 and 3.4 nmol/l, respectively. As compared to bromocriptine, CAB was more potent in inhibiting the binding of [3H]N-n-propylnorapomorphine and it occupied the receptor for longer. These effects were observed in all areas of the rat brain. In vivo, CAB at doses of 0.125-1 mg twice weekly caused a dose-dependent suppression of PRL secretion in women with hyperprolactinaemia. CAB was shown to be significantly more effective than bromocriptine in inducing a complete biochemical response and clinical efficacy and was better tolerated than bromocriptine in the majority of patients. Notable tumour shrinkage until tumour disappearance was observed during CAB treatment in most patients with macroprolactinoma. CAB was also shown to be effective in patients resistant or poorly responsive to bromocriptine. In view of the limited data on CAB-associated pregnancies and the long half-life of the drug, it is currently recommended that women seeking to became pregnant, once ovulatory cycles have been established, should discontinue CAB therapy 1 month before they intend to conceive. However, no data on negative effects on pregnancy or offspring have been reported. The great efficacy of CAB together with its excellent tolerability makes this drug the current treatment of choice for the majority of patients with hyperprolactinaemic disorders. Very recently, the efficacy of CAB treatment has been reported in patients with acromegaly and clinically non-functioning adenomas with controversial results. CAB was also reported to have some efficacy in patients with Nelson's syndrome and Cushing's disease although these data are available only for limited case reports.

Animals↗
PubMed2000

Effect of GH and/or testosterone deficiency on the prostate: an ultrasonographic and endocrine study in GH-deficient adult patients.

BACKGROUND: The role of IGF-I in prostate development is currently under thorough investigation since it has been claimed that IGF-I is a positive predictor of prostate cancer. OBJECTIVE: To investigate the effect of chronic GH and IGF-I deficiency alone or associated with testosterone deficiency on prostate pathophysiology in a series of patients with hypopituitarism. DESIGN: Pituitary, androgen and prostate hormonal assessments and transrectal prostate ultrasonography (TRUS) were performed in 30 men with adulthood onset GH deficiency (GHD) and 30 age-matched healthy controls, free from previous or concomitant prostate disorders. RESULTS: Plasma IGF-I levels were significantly lower in GHD patients than in controls (Pearson's coefficient P<0.0001). At study entry, 6 of the 13 hypogonadal patients and 7 of the 17 eugonadal patients had plasma IGF-I below the age-adjusted normal range. At study entry, testosterone levels were low in 13 patients (mean +/-s.e.m., 3.8+/-1.0 nmol/l) while they were normal in the remaining 17 (19.4+/-1.4 nmol/l). No difference in prostate-specific antigen (PSA), and PSA density was found between GHD patients (either hypo- or eugonadal) and controls, while free PSA levels were significantly higher in eugonadal GHD than in controls (0.4+/-0.04 vs 0.2+/-0.03 microg/l; P<0.01). No difference in antero-posterior prostate diameter and transitional zone volume (TZV) was observed among groups, while both transverse and cranio-caudal diameters were significantly lower in hypogonadal (P<0.01) and eugonadal GHD patients (P<0.05) than in controls. Prostate volume (PV) was significantly lower in hypogonadal GHD patients (18.2+/-3.0 ml) and eugonadal GHD patients (22.3+/-1.6 ml), than in controls (25.7+/-1.4, P<0.05). The prevalence of prostate hyperplasia (PV>30 ml) was significantly lower in hypogonadal and eugonadal GHD patients, without any difference between them (15.3% and 5.8%), than in controls (43.3%) (chi(2)=6.90, P=0.005). No difference was found in PV between patients with normal or deficient IGF-I levels both in the hypogonadal group (19. 9+/-4.7 vs 17.3+/-4.0 ml) and in the eugonadal group (22.6+/-2.3 vs 21.8+/-2.5 ml). When controls and patients were divided according to age (<60 years and >60 years), PV was significantly lower in hypogonadal GHD patients aged below 60 years than in age-matched controls (P<0.01) or eugonadal GHD patients (P<0.01), without any difference between controls and eugonadal GHD patients. Controls aged above 60 years had significantly higher PV than both hypogonadal and eugonadal GHD patients (P<0.01). Calcifications, cysts or nodules were found in 56.7% of patients and in 50% of controls (chi(2)=0.067, P=0.79). In controls, but not in GHD patients, PV and TZV were correlated with age (r=0.82, r=0.46, P<0. 0001 and P<0.01 respectively). PV was also correlated with GH (r=-0. 52, P=0.0026), IGF-I (r=-0.62, P=0.0002) and IGF-binding protein 3 (IGFBP-3) levels (r=-0.39, P=0.032) but neither with testosterone or dihydrotestosterone (DHT) levels. In GHD patients TZV but not PV was correlated with age (r=0.58, P=0.0007) and neither TZV nor PV were correlated with GH, IGF-I or IGFBP-3 levels. CONCLUSIONS: Chronic GH deficiency in adulthood causes a decrease in prostate size, mostly in patients with concomitant androgen deficiency and age below 60 years, without significant changes in the prevalence of structural prostate abnormalities.

Adenoma↗
PubMed2000

Power Doppler ultrasonographic assistance in percutaneous ethanol injection of autonomously functioning thyroid nodules.

The purpose of this study was to explore the potential role of power Doppler sonography in guiding percutaneous ethanol injection of autonomously functioning thyroid nodules. Thirty-two patients with pretoxic adenoma and 15 with toxic adenoma underwent percutaneous ethanol injection under power Doppler sonographic guidance. All patients with pretoxic adenoma and 13 of 15 patients with toxic adenoma were treated successfully (normalization of circulating thyroid hormones and thyroid stimulating hormone levels and disappearance of nodular hyperactivity with complete recovery of extranodular tracer uptake at scintigraphy). Power Doppler sonography showed the progressive reduction of the intranodular blood flow until its extinction after 6 to 12 months. Nodular shrinkage was obtained in all patients (from 10.85 +/-1.04 to 2.9 +/- 0.3 ml in pretoxic adenoma and from 15.4 +/- 1.8 to 4.2 +/- 0.7 ml in toxic adenoma. Power Doppler sonographic guidance seems to improve the outcome of percutaneous ethanol injection, allowing detection of blood flow even in very small vessels, permitting the ethanol to be guided toward the main afferent vessels of the nodules, and making it possible to monitor the diffusion and the effects of ethanol on nodular vascularization.

Administration, Cutaneous↗
PubMed2000

Growth hormone and cardiac function.

Impaired cardiovascular function, which may reduce life expectancy, has recently been demonstrated both in GH deficiency and excess. Moreover, experimental and clinical studies support the evidence implicating GH and/or IGF-I in the regulation of heart development. The existence of a specific acromegalic cardiomyophathy characterized by myocardial hypertrophy with interstitial fibrosis, lympho-mononuclear infiltration and areas of monocyte necrosis which often result in biventricular concentric hypertrophy has been recenty demonstrated. By contrast, patients with childhood or adulthood-onset GH deficiency (GHD) present with abnormalities of structure and function of the left ventricle. In these patients, a significant increase in the vascular intima-media thickness and an increased number of atheromatous plaques have also been reported. The abnormalities of cardiovascular system could be partially reverted by suppressing GH and IGF-I levels in acromegaly or after GH remplacement therapy in GHD patients. The evidence that GH is able to increase cardiac mass suggested its use in the -treatment of chronic heart failure of diverse etiologies. GH administration was -demonstrated to induce an improvement in hemodynamics and clinical status in some patients. Although these data should be confirmed in double-blind placebo controlled studies in larger series, the promising results open new perspectives for GH treatment in humans.

Acromegaly↗
PubMed1999

Lack of T cell proliferation without induction of nonresponsiveness after antigen presentation by endothelial cells.

BACKGROUND: After priming or reactivation in lymph nodes, T cells recirculate to sites of inflammation, and enter tissues by migrating across activated endothelium. Given that activated endothelial and tissue parenchymal cells express both class I and class II MHC molecules, it is probable that transmigrating T cells encounter cognate antigen on endothelial cells, and on tissue parenchymal cells once they have entered the tissue. METHODS: In this study the consequences of antigen presentation by endothelial and epithelial cells to human CD4+ T cell clones were analyzed and compared by a two-step culture system. RESULTS: T cell clones that required B7-mediated costimulation to be activated were found not to be able to proliferate to antigen presented by either endothelial or epithelial cells, unless trans-costimulation was provided by the addition of B7-transfected cells in the cultures. Furthermore, antigen presentation by epithelial cells induced nonresponsiveness in the T cell clones. In contrast, after cognate recognition on endothelial cells, the ability of the T cell clones to proliferate to a subsequent rechallenge with antigen presented on a specialized APC was unaffected. CONCLUSIONS: These data suggest that endothelial cells have unique properties as antigen-presenting cells, in that they do not influence the subsequent reactivity of cognate T cells.

Animals↗
PubMed1999

Antigen recognition influences transendothelial migration of CD4+ T cells.

The functional significance of MHC class II expression by vascular endothelial cells remains obscure. In this study the possibility that Ag presentation by endothelial cells (EC) influences T cell transmigration, facilitating the recruitment of Ag-specific T cells into tissues, was investigated. The frequencies of T cells with specificity for an HLA-DR alloantigen, or for the recall Ag tetanus toxoid (TT), were measured in peripheral blood CD45RO+ (memory) CD4+ T cells before and after transmigration through gamma-IFN-treated EC monolayers. Frequencies of anti-DR17, IL-2-secreting T cells were fourfold higher in the T cells that transmigrated through a monolayer of DR17-expressing EC. Similar increases were seen in TT-specific, DR7-restricted T cells that transmigrated through TT-pulsed, DR7-expressing EC. To examine more directly the effects of cognate recognition of Ag presented by EC, T cell clones were used. For clones that proliferated in a costimulation-independent manner to Ag presented by EC, cognate recognition arrested transmigration. In contrast, Ag presentation by EC to B7-dependent T cell clones, which do not proliferate following cognate recognition of EC, enhanced the rate of transendothelial migration. These data suggest that Ag presentation by EC may serve to augment the recruitment of Ag-specific T cells into tissues and that proliferation and transmigration are mutually exclusive T cell responses.

B7-1 Antigen↗
PubMed1999

Inhibition of T cell apoptosis by IFN-beta rapidly reverses nuclear translocation of protein kinase C-delta.

Type I interferons rescue activated human T cells from cytokine deprivation-induced apoptosis. Our data now show that IFN-beta also rapidly inhibits apoptotic signals induced through the Fas receptor (CD95) in human T cells. To identify upstream signaling elements that could be targets of IFN-beta, we have studied protein kinase C (PKC). PKC-delta is actively involved in the regulation of apoptosis and immunofluorescence staining revealed that early in apoptosis PKC-delta accumulated in the nucleus. Addition of IFN-beta to T cells already deprived of survival factors or treated with anti-Fas antibody caused a rapid retranslocation of PKC-delta away from the nucleus. Furthermore, the generation of a constitutively active catalytic fragment by cleavage of PKC-delta by caspase 3 occurred only after translocation of full-length PKC-delta to the nucleus. IFN-beta also inhibited caspase 3 and the proteolytic activation of PKC-delta. We conclude from these studies that nuclear translocation of PKC-delta is an early event in T cell apoptosis and that IFN-beta rapidly reverses this process.

Apoptosis↗
PubMed1999

The pituitary uptake of (111)In-DTPA-D-Phe1-octreotide in the normal pituitary and in pituitary adenomas.

The aim of this study was to compare the pituitary (111)In-DTPA-D-Phe1-octreotide uptake measured in 49 patients subjected to the scintigraphy for SS-R expressing tumors not located in the sellar region with that measured in 38 patients with pituitary adenomas. The 87 subjects enrolled in this study were divided into two groups: the first included SSR-expressing tumors (SS-ET), 10 thymomas, 13 differentiated thyroid carcinomas, 4 carcinoids, 5 neuroendocrine tumors, 5 insulinomas, 6 melanomas, 2 renal carcinomas, 2 pheocromocytomas, and 2 parathyroid tumors, while the second included pituitary adenomas, 25 GH-secreting, 4 GH/PRL-mixed and 9 clinically nonfunctioning adenomas (NFA). Planar and single-photon-emission tomography images of the head were obtained 2-4 and 24 hours after the injection of 77-103 MBq of (111)In-DTPA-D-Phe1-octreotide and pituitary uptake was measured by the region of interest method. A 4 point score was used to grade the pituitary-to-blood (T-to-B) ratios: 0=negative; 1 =faint (T-to-B=<1.5); 2=moderate (T-to-B=1.6-3.5); 3=intense (T-to-B=>3.5). In patients with pituitary adenomas, the percent suppression of GH and alpha-subunit levels after 6-12 months of octreotide treatment (0.3-0.6 mg/day) was correlated to T-to-B ratios. After 2-4 hr from injection, pituitary (111)In-DTPA-D-Phe1-octreotide uptake was moderate/intense in 2 out of 49 SS-ET (4%), 18 out of 29 acromegalics (62%) and 6 NFA (66.6%), while a faint uptake was detected in 4 SS-ET (8%), 8 GH-secreting adenomas (27.5%) and 3 NFA (33.3%). Negative scan was detected in the remaining 43 SS-ET (87.7%) and 3 GH-secreting microadenomas (10.3%). 24 hr after injection, pituitary (111)In-DTPA-D-Phe1-octreotide uptake was moderate/intense in SS-ET (10.2%), 21 GH-secreting adenomas (72.4%), and 9 NFA (100%) while a faint uptake was detectable in 15 SS-ET (30.6%), and 6 GH-secreting adenomas (20.7%). No uptake was visualized in 29 SS-ET, and 2 GH-secreting adenomas. By MRI a pituitary tumor was shown in the 2 SS-ET with early moderate tracer uptake. Normalization of circulating GH/IGF-I levels and suppression of alpha-subunit levels was achieved in 16 of 18 acromegalics (88.9%) and 5 of 6 NFA-bearing patients, respectively, with scan scored 2-3 at early images. Eleven acromegalics (37.9%) and 2 NFA (22.2%) displayed significant tumor shrinkage (> or =30% of baseline size) during long-term octreotide therapy. Both in GH-secreting and in NFA, a significant correlation was found between percent GH or alpha-subunit suppression after 6-12 months of octreotide therapy and T-to-B ratios both in early (r=0.626; p<0.0001 and r=0.738, p=0.003, respectively) and late images (r=0.569; p=0.002 and r=0.8, p=0.01, respectively). In conclusion, the (111)In-DTPA-D-Phe1-octreotide uptake in pituitary adenomas was significantly correlated to octreotide treatment. However, since pituitary (111)In-DTPA-D-Phe1-octreotide uptake was clearly detectable in 40% of patients with SS-ET not located in the pituitary region at 24 hr post-injection, (111)In-DTPA-D-Phe1-octreotide scintigraphy with late pituitary images can not be considered an useful method to predict the chronic responsiveness to octreotide in individual patients. Caution should also be taken in evaluating the results of the scintigraphy with early images in patients with scant uptake before excluding them from treatment.

Adenoma↗
PubMed1999

Effects of two years of growth hormone (GH) replacement therapy on bone metabolism and mineral density in childhood and adulthood onset GH deficient patients.

The aim of the current study was to evaluate bone metabolism and mass before and after 2 years of GH replacement therapy in adults with childhood or adulthood onset GH deficiency. Thirty-six adults with GH deficiency, 18 with childhood onset, 18 with adulthood onset GH deficiency and 28 sex-, age-, height- and weight-matched healthy subjects entered the study. Biochemical indexes of bone turnover such as serum osteocalcin, serum carboxyterminal telopeptide of type-I procollagen, urinary hydroxyproline/creatinine and deoxypyridinoline/creatinine, of soft tissue formation such as aminoterminal propeptide of type-III and bone mineral density were evaluated. Childhood onset GH deficient patients had significantly decreased bone (osteocalcin: 2.5+/-1.3 vs 6.6+/-4.8 mcg/l, p<0.001) and soft tissue formation (aminoterminal propeptide of type III: 273+/-49 vs 454+/-23 U/I, p<0.001) indexes and normal bone resorption indexes (serum carboxyterminal telopeptide of type-I procollagen: 105+/-48 vs 128+/-28 mcg/l p=NS; urinary hydroxyproline/creatinine: 0.19+/-0.16 vs 0.28+/-0.16 mmol/mol, p=NS; urinary deoxypyridinoline/creatinine: 21 +/-10 vs 25+/-8 mcmol/mol, p=NS) compared to healthy subjects. On the contrary, no significant difference in bone turnover indexes between adulthood onset GH deficient patients and healthy subjects was found. Moreover, significantly decreased bone mineral density at any skeletal site and at whole skeleton was found in GH deficient patients compared to healthy subjects (e.g. femoral neck: 0.74+/-0.13 vs 0.97+/-0.11 g/cm2, p<0.001). In addition, a significant reduction of bone mineral density was found in childhood compared to adulthood onset GH deficient patients at any skeletal site, except at femoral neck. After 3-6 months of treatment, both groups of patients had a significant increase in bone turnover and in soft tissue formation. In particular, in childhood onset GH deficient patients after 3 months osteocalcin increased from 2.5+/-1.3 to 7.9+/-2.1 mcg/l, p<0.001 aminoterminal propeptide of type-III from 273+/-49 to 359+/-15 U/I p<0.001; serum carboxyterminal telopeptide of type-I procollagen from 105+/-48 to 201+/-45 mcg/l, p<0.001; urinary hydroxyproline/creatinine from 0.19+/-0.16 to 0.81+/-0.17 mmol/mol, p<0.001; urinary deoxypyridinoline/creatinine from 21 +/-10 to 54+/-20 mcmol/mol, p<0.001; while in adulthood onset GH deficient patients after 6 months osteocalcin increased from 4.2+/-3.6 to 6.5+/-1.9 mcg/l, p<0.05; aminoterminal propeptide of type- III from 440+/-41 to 484+/-37 U/I, p<0.05; serum carboxyterminal telopeptide of type-I procollagen from 125+/-40 to 152+/-22 mcg/l, p<0.05; urinary hydroxyproline/creatinine from 0.24+/-0.12 to 0.54+/-0.06 mmol/mol, p<0.001; urinary deoxypyridinoline/creatinine from 23+/-8 to 42+/-5 mcmol/mol, p<0.001. No significant difference in bone turnover between pre- and post-treatment period was found after 18-24 months of GH therapy. Conversely, bone mineral density was slightly reduced after 3-6 months of GH therapy, while it was significantly increased after 18-24 months. In fact, femoral neck bone mineral density values significantly rose from 0.74+/-0.13 g/cm2 to 0.87+/-0.11 g/cm2 (pre-treatment vs 2 years of GH treatment values). In conclusion, patients with childhood or adulthood onset GH deficiency have osteopenia that can be improved by long-term treatment with GH.

Adult↗
PubMed1999

Unusual association of thyroiditis, Addison's disease, ovarian failure and celiac disease in a young woman.

The coexistence of autoimmune endocrine diseases, particularly autoimmune thyroid disease and celiac disease (CD), has recently been reported. We here present a 23-year-old woman with a diagnosis of hypothyroidism due to Hashimoto's thyroiditis, autoimmune Addison's disease, and kariotypically normal spontaneous premature ovarian failure. Considering the close association between autoimmune diseases and CD, we decided to search for IgA anti-endomysium antibodies (EmA) in the serum. The positivity of EmA and the presence of total villous atrophy at jejunal biopsy allowed the diagnosis of CD. On a gluten-free diet the patient showed a marked clinical improvement accompanied, over a 3-month period, by a progressive decrease in the need for thyroid and adrenal replacement therapies. After 6 months, serum EmA became negative and after 12 months a new jejunal biopsy showed complete mucosal recovery. After 18 months on gluten-free diet, the anti-thyroid antibodies titre decreased significantly, and we could discontinue thyroid substitutive therapy. This case emphasizes the association between autoimmune polyglandular disease and CD; the precocious identification of these cases is clinically relevant not only for the high risk of complications (e.g. lymphoma) inherent to untreated CD, but also because CD is one of the causes for the failure of substitute hormonal therapy in patients with autoimmune thyroid disease.

Addison Disease↗
PubMed1999

Percutaneous ethanol injection under Power Doppler ultrasound assistance in the treatment of autonomously functioning thyroid nodules.

Power Doppler (PD) is a recent color-Doppler Ultrasound (US)-technique, which allows to detect the presence of flow even in very small vessels, providing a sort of angiographic micromap. The aim of this study was to evaluate whether percutaneous ethanol injection (PEI) outcome might be improved by injecting the ethanol into the nodule under PD assistance. Thus, 14 patients affected with pretoxic (PTA) and 8 with toxic adenoma (TA) were submitted to this alternative tool. Before PEI, all patients were submitted to a careful endocrinological study, including an US-guided fine-needle biopsy in order to exclude the presence of malignancy. In addition, all the nodules were evaluated at PD-US and their vascular patterns were recorded on videotape and compared with those obtained after treatment. The procedure consisted of slow injection of sterile ethanol under direct PD-US control. The number of PEI sessions was 2.3+/-0.1 in PTA and 3.0+/-0.3 in TA. All patients were also evaluated 3, 6, 12 and 18 months after PEI. Successful therapy was considered when normalization of thyroid hormones and TSH was achieved together with the disappearance of nodular hyperactivity and complete recovery of extra-nodular tracer uptake at scintigraphy. PEI was tolerated very well by all patients. The most common side effect was a transient local or irradiated pain. All patients with PTA and 6 out of 8 patients with TA were successfully treated. In these cases, PD-US showed the progressive reduction of the intranodular blood flow, up to its extinction after 6-12 months, with the presence of little perilesional vascular spots. Nodular shrinkage was obtained in all patients (from 4.7+/-0.7 to 1.1+/-0.4 ml in PTA and from 21.0+/-2.8 to 6.2+/-1.6 ml in TA). In conclusion, PD assistance improves PEI procedure, since it allows to guide the ethanol injection towards the principal afferent vessels of the nodules and to monitor the diffusion and the effects of ethanol on nodular vascularization.

Adenoma↗