Biomedical subjects

C Fiumara

Publications and source records attributed to C Fiumara.

At least 19 recordsLinked to original sources

PubMed1997

Physiological role of the opioid-cholinergic interaction in growth hormone neuroregulation: effect of sex and food intake.

Studies performed in animals and humans have suggested a functional interaction between opioid and cholinergic systems in the control of growth hormone (GH) secretion. Moreover, the sex-dependent modulation of GH secretion in humans is well established. To investigate the role of sex and food intake in the regulation of the reciprocal influences of opioids and acetylcholine in the modulation of GH secretion, we studied the GH response to pyridostigmine (PYR) alone and during a naloxone (NAL) infusion in a group of normal men and women before a meal (at 1:00 PM) and postprandially. In women, the response of GH to PYR alone before the meal was significantly lower than in the men (area under the curve [AUC], mean +/- SEM, 320.18 +/- 87.16 v 1,031.06 +/- 333.21 micrograms/L/90 min, P < .01). Before the meal, NAL completely abolished the response of GH to PYR in men (AUC, 1,031.06 +/- 333.21 v 16.50 +/- 7.50 micrograms/L/90 min, P < .01), whereas infusion of NAL did not significantly modify the GH response to PYR in women. Consumption of the meal significantly decreased PYR-induced GH release in both women (AUC, 21.75 +/- 12.75 v 320.18 +/- 87.16 micrograms/L/90 min, P < .05) and men (AUC, 45.75 +/- 18.75 v 1,031.06 +/- 333.21 micrograms/L/90 min, P < .01). Conversely, food intake did not change the effects of NAL infusion on the GH response to PYR either in women or in men. We conclude that the sex-dependent opioid modulation of PYR-induced GH secretion is observed before a meal but not in the postprandial state. Food intake may be hypothesized to influence the cholinergic regulation of GH secretion and the sex-dependent opioid modulation of central cholinergic tone.

Adult↗

PubMed1996

Pre- and postprandial pyridostigmine and oxiracetam effects on growth hormone secretion in anorexia nervosa.

Previous studies have shown that food ingestion is not capable of inhibiting the GHRH-induced GH release in anorexia nervosa, at variance with what is observed in normal subjects. Moreover, a cholinergic alteration has been hypothesized in this disorder. In a group of 24 anorectic patients in a stabilized phase of the illness, we tested, before and after a standard meal, the GH response to GHRH alone and after pre-treatment with pyridostigmine, an inhibitor of acetylcholinesterase, and, on a different day, with oxiracetam, which stimulates the central cholinergic neurones. The GH response to GHRH was significantly increased by both drugs in a fasting state. The postprandial response was not significantly modified by pyridostigmine nor by oxiracetam. Neither of these compounds was able to enhance the postprandial GH 'paradoxical' response to GHRH in anorectic patients. The lack of effect of both groups postprandially also suggests a suppression of somatostatinergic activity.

Acetylcholinesterase↗

PubMed1996

Naloxone influence on the growth hormone, prolactin and thyrotropin response to thyrotropin releasing hormone in acromegalic patients.

In order to gain insight into the neuroendocrine mechanism underlying the paradoxical GH response to TRH in acromegalic patients, we have investigated the effect of an infusion of Naloxone (Nal, 1.6 mg/hr for two hours), on a TRH test performed both in responder (n = 9) and non-responder (n = 5) acromegalic patients. The response of GH, PRL and TSH to TRH injection were evaluated. NAL did not exert significant variations in the GH response, even if different patterns of GH response during NAL were observed in the group of TRH-responder patients. Similarly, TRH-induced PRL response was not significantly affected by the infusion of an opiate antagonist. On the contrary, a significant inhibition of the TSH response was observed in the group of TRH-responder patients (delta TSH after TRH 4.76 +/- 1.11 microU/ml, after NAL + TRH 2.81 +/- 0.99 microU/ml, p < 0.05). No significant effects were observed in the TRH non-responder patients (delta TSH after TRH 4.58 +/- 1.44 microU/ml, after NAL + TRH 6.26 +/- 3.27 microU/ml). The differences observed in the two groups of patients could be ascribed to a different endogenous somatostatinergic tone and could furnish a prognostic indication in acromegalic patients.

Acromegaly↗

PubMed1996

Superselective intra-arterial radiometabolic therapy with I-131 lipiodol in hepatocellular carcinoma.

Superselective transcatheter arterial radioembolization with radioiodinated lipiodol and gelatin sponges was evaluated in 11 patients with nodular hepatocellular carcinoma. Thirteen tumor nodules were treated using 3-5 ml of lipiodol labeled with 259 to 2220 MBq of I-131 followed by gelatin sponge with the following results: 1) there was elevated uptake in 12 tumor nodules with high tumor-to-background ratios: 2) there was excellent clinical tolerance to the treatment (stable cirrhosis in 5 patients and cirrhosis progression in 2 cases); 3) there was good disease control with size reduction in five tumor lesions (41%) and no increase in seven lesions (59%) followed for 2 years; 4) there was a 2-year survival rate of 70%; and 5) three deaths due to hepatic failure at 2, 3, and 20 months after therapy. Superselective arterial radioembolization with I-131 lipiodol is a useful palliative approach to inoperable hepatocarcinoma, providing long-term local control without severe complications in the progression of cirrhosis.

Aged↗

PubMed1996

Radiosensitization with low-dose carboplatin enhances pain palliation in radioisotope therapy with strontium-89.

Strontium-89 (89Sr) is currently used for the treatment of painful bone metastases. This study reports the use of low-dose carboplatin as a radiosensitizer in 89Sr radioisotope therapy. The study design comprised two groups: 15 patients treated with 89Sr (148 MBq) followed by carboplatin (100 mg m-2 at 7 and 21 days) and 15 patients treated with 89Sr alone. Their pain response was assessed 8 weeks post-injection. Follow-up was continued for up to 1 year in the survivors. Twenty-seven patients were evaluable. A pain response was observed in 20 of 27 (74%) patients. The pain response in the patients treated with 89Sr and carboplatin was clearly superior to that seen in the patients treated with 89Sr alone (P = 0.025), whereas survival was only marginally better in the combined treatment group (8.1 vs 5.7 months, P = 0.19). No clinically significant adverse effects or myelosuppression by carboplatin were observed. Low-dose carboplatin enhances the effects of 89Sr radioisotope therapy on pain from bone metastases.

Adult↗

PubMed1995

GH response to oral and intravenous glucose load in acromegalic patients.

The lack of inhibition of Growth Hormone (GH) levels after glucose load is considered a marker of inappropriate GH secretion in acromegaly. In order to investigate the physiopathology of this phenomenon, we have studied the GH variations after an oral glucose load (0.75 g/kg BW per os, OGTT) or intravenous glucose bolus (25 g i.v., IVGTT), in a group of 12 acromegalic patients, aged 20 +/- 69 yr (mean 48), 5 males and 7 females, with basal GH levels ranging from 11 to 76.2 ng/ml. The results indicate that only a group of acromegalic patients (group 1) had a partial GH inhibition after OGTT (mean decrease: 56.4 +/- 4.2%), but in no patients GH levels were influenced by intravenous administration of glucose. It is possible that in group 1 patients, the gastroenteric response could partially influence the GH secretion by the pituitary tumor, probably due to an increased peripheral somatostatin release. The dissociation of the GH response to OGTT and IVTT could indicate a supersensitivity to peripheral somatostatin, related to a deficiency in central somatostatinergic tone and therefore represent a more unfavourable prognostic sign.

Acromegaly↗

PubMed1994

Opioid dysregulation in anorexia nervosa: naloxone effects on preprandial and postprandial growth hormone response to growth hormone-releasing hormone.

Previously, we have shown that in the opposite extremes of nutritional status, obesity and anorexia nervosa (AN), growth hormone (GH) response to growth hormone-releasing hormone (GH-RH) is not inhibited by the ingestion of a normal 800-cal meal consumed at lunch time (1 PM), which is at variance with results in normal subjects. However, in obese patients the postprandial increase in GH response to GH-RH is inhibited by an infusion of naloxone (NAL). In this study we have tested anorectic patients, performing the following tests at 1 PM: GH-RH test (50 micrograms IV) or, in a different day session, NAL (1.6 mg/h, starting 30 minutes before GH-RH) + GH-RH test (50 micrograms IV). The tests were performed in the following three different experimental conditions: (1) short-term fasting studies (lasting from breakfast), (2) long-term fasting studies (from midnight of the day before) and (3) postprandial studies (after a standard meal consumed 1 hour before the test). In AN, the GH response to GH-RH was not influenced by NAL infusion at 1 PM, in both short- and long-term fasting studies (short-term fasting: peak values after GH-RH alone, 26.5 +/- 6.5 ng/mL, during NAL, 28.0 +/- 3.3 ng/mL; long-term fasting: peak values after GH-RH alone, 32.2 +/- 6.8 ng/mL, during NAL, 30.6 +/- 4.0 ng/mL). A partial NAL-inhibitory effect was instead observed in postprandial studies, as evidenced by the calculation of areas under the curve ([AUCs] 1,662.1 +/- 90.0 after GH-RH alone v 1,090.5 +/- 245.4 ng/mL/h during NAL).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

Growth hormone response to growth hormone-releasing hormone in early abstinent alcoholic patients.

The alpha-2-adrenoceptor agonist clonidine is able to stimulate GHRH secretion directly or via beta-endorphin and, therefore, induces a GH release in normal subjects. This effect has been shown to be blunted in alcoholism during early abstinence, due to central alterations of adrenergic mechanisms. To evaluate pituitary responsiveness to direct stimulation with GHRH, we have studied the GH and PRL response to GHRH in 10 alcoholics during early abstinence. Our data indicate that the pituitary response to GHRH is intact in abstinent alcoholics, except in obese patients, who displayed a blunted GH response. GHRH did not increase PRL. The dissociation between clonidine and GHRH in GH stimulation could reveal a different neuroendocrine mechanism, in comparison with other psychiatric disorders (anorexia nervosa), in which such a dissociation is accompanied by a PRL response to GHRH.

Adult↗

PubMed1993

Opioid-dopaminergic interactions in primary empty sella.

Previous studies have indicated different abnormalities of PRL secretion in patients with primary empty sella (PES). Since it is known that endogenous opiates and dopamine interact in modulating PRL secretion, we have studied the effect of an opiate receptor blockade (with Naloxone, NAL, 1.6 mg/h as a continuous infusion) on anterior pituitary hormones and on PRL responsiveness to metoclopramide (MCP), in 10 premenopausal normoprolactinemic patients with PES, studied in follicular phase, in order to investigate neurotransmitter abnormalities present in such a syndrome. NAL failed to significantly affect LH and FSH basal levels; on the contrary, slight but significant increases in PRL and GH secretion were observed. NAL partially blunted the PRL responsiveness to the dopaminergic blockade, which was very marked when tested after MCP alone. These data confirm that the modulation of anterior pituitary hormone secretion is different in PES patients, when compared with normal subjects. The infusion of NAL induced a "paradoxical" increase in hormones (PRL and GH) which are normally stimulated by endogenous opiates; but, on the other side, it blocked the marked PRL responsiveness to the dopaminergic blockade, which is characteristic of PES syndrome. This phenomenon seems to indicate that the relationships between dopaminergic and opiatergic neurons could be modified by the neuroanatomic alteration which is present in this complex syndrome.

Adult↗

PubMed1993

Pyridostigmine effects on TSH response to TRH in adult and children obese subjects.

Thyrotropin releasing hormone (TRH) administration is known to induce a greater TSH response in normal subjects than in obese subjects. In obesity even GH and PRL response to various stimuli are blunted, presumably because of an augmented somatostatinergic tone in obese subjects. Further studies have shown that pyridostigmine (Pyr), an acetylcholinesterase inhibitor, is capable of augmenting GH in obesity by means of somatostatin inhibition. In order to evaluate the possible interference of an increased somatostatinergic tone on TSH secretion, we studied the TSH response to a TRH bolus in 5 obese children with or without a pyr pretreatment. Similarly, we tested a group of 10 obese adult subjects, with TRH alone or TRH plus pyr administration, 30 min or 60 min before TRH. All subjects had a body weight of 30-50% greater than I.B.W. Our data show that a pretreatment with pyr, 60 min before TRH administration, significantly augments the TSH response in adult obese subjects but not in children; the modality of pyr administration seems to be crucial to evidenciate such an alteration since the pyr pretreatment is not effective when administered 30 min before TRH. The absence of this pyr effect in obese children induces to hypothesize that somatostatinergic tone is differentially modulated in children vs adult obese subjects.

Adolescent↗

PubMed1993

Naloxone effects on post-prandial glucose, insulin and C-peptide levels in obese subjects.

In order to investigate the relationships between glucose metabolism, insulin secretion and endogenous opioids in obese patients, we have studied the effects of a naloxone infusion on insulin and C-peptide release after a normal meal (800 kcal) eaten at 12.00 hr in 16 obese women, aged 20-61 yr, with a BMI ranging from 25 to 37.2 kg/m2, with normal glucose tolerance (Group 1) and with NIDDM (Group 2). Naloxone was administered in a bolus of 1.6 mg i.v., followed by a continuous infusion of 4 mg in 2 hr starting immediately after feeding. In Group 1 naloxone infusion significantly increased the glucose levels, but insulin secretion was unaffected. In Group 2, naloxone infusion failed to modify significantly the postprandial levels of glucose, insulin and C-peptide. Therefore, in our study naloxone infusion seems to have beta-endorphin-like effects in non-diabetic obese subjects by increasing their glycemic levels, with no evidence of expected insulin decrease. In diabetic obese patients we observed a trend towards decrease in glycemic values during naloxone infusion, as expected, due to insulin plasma levels increase. By these data we can hypothesise a complex regulatory role of opioids in metabolic balance in obesity. In diabetic patients, naloxone can improve the surviving insulin secretion with better glucose tolerance. In non-diabetic subjects naloxone exerts its effects, probably, on peripheral organs.

Adult↗

PubMed1993

[Gastroenterologic pathology and replacement organotherapy in thyroidectomized patients].

Thyroid replacement therapy in patients treated by near-total or total thyroidectomy, as well as spontaneous hypothyroidism , can be difficult in patients with alterations in absorption functions or specific gastroenteric diseases. We have studied 25 patients, 22 women and 3 men, 18-72 years old (mean 47 years), affected by spontaneous or post-surgical hypothyroidism, who presented, during the usual replacement therapy, persistently elevated or high-normal TSH levels, and therefore required repeated variations in the prescribed dose of thyroxine. In these patients we evaluated hormone pattern, the presence of autoantibodies (anti-tyroglobulin, anti-Sm, anti-DNA, anti-microsomal antigens, anti-gliadin and anti-parietal cell), and performed an esophagogastroduodenoscopy (EGD) with histological examination. In all patients, plasma TSH ranged from 2.5 to 20 microU/ml. Only 17% of patients exhibited the presence of antibodies against thyroglobulin, 17% of patients had antibodies against microsomal antigens, 6% of patients presented antibodies against nuclear antigens; 4% had against gliadin. Histological examination revealed chronic gastritis (98%) with atrophic aspects (20%) and intestinal metaplasia (28%); and chronic duodenitis (86%) with villus abnormalities (23%) and total villus atrophy (4%). We underline the case of a patient, treated by total thyroidectomy for papillary carcinoma, who presented, two months after starting L-thyroxine therapy, a recurrence of celiac disease, that had been silent after childhood. The EGD showed, at the level of the second duodenal segment, a reduction of number and thickness of mucosal folds; the histological examination showed total villus atrophy, elongated crypts and a dense infiltration of chronic inflammatory cells in the lamina propria. Our experience underlines the frequent association of gastroenteric disease and hypothyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

[Adrenal gland cysts. Our experience].

Adrenal cysts are an uncommon finding, in most cases unexpectedly discovered in the evaluation of nonspecific abdominal pain or at autopsy. Cystic adrenal masses can be classified into neoplastic and non-neoplastic aetiologies. The distinction between malignant and benign adrenal cysts can still be difficult. Cysts of neoplastic aetiology occur as a result of necrosis and cystic degeneration within both benign and malignant tumours. Non-neoplastic cysts have been conventionally divided into four categories: endothelial (45%), haemorrhagic or pseudocystic (39%), epithelial (9%) and parasitic (7%). Small adrenal cysts are clinically silent, while cysts of large size can cause displacement and compression of adjacent organs. The radiological aim is to detect the adrenal mass and CT is regarded as the best method available for this detection, although a differentiation between benign and malignant tumours can be difficult. Here we report our experience in nine patients with adrenal cysts. Abdominal pain was the dominant sign, two patients were hypertensive, one presented a palpable mass at abdominal examination and another presented oligomenorrhea with hypertrichosis, in five patients the adrenal mass was discovered unexpectedly during radiologic examination. All cysts in our patients were unilateral. All patients were examined by ultrasound and CT, one by RM, three by 75Se-Seleniumcholesterol cortical scintigraphy and two by 131I-MIBG medullary scintigraphy. In three patients a percutaneous aspiration of the cyst was performed via a posterior approach with CT or US guidance. This approach has been used for diagnostic and therapeutic purposes. Examination of aspirated cyst fluid for steroid hormones showed markedly elevated cortisol levels compared with normal plasma cortisol levels in one patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Gland Diseases↗

PubMed1993

[A case of adrenal adenoma with radiologic "cystic" appearance associated with hypophyseal adenoma].

Expansive lesions of the adrenal glands without signs of hormonal hypersecretion are usually discovered "incidentally", and are therefore called "incidentalomas". Since the silent adrenal masses constitute a heterogeneous group of lesions, the most important issue raised by the identification of these masses is their possible malignant potential. Therefore, the age and sex of the patients, the size of the mass, its imaging characteristic and its histologic features are the most important factors in the assessment of nonfunctioning adrenal masses. We report here the case of a women, aged 43 years mild hypertension, harbouring a great adrenal mass of 8 cm diameter, with cystic appearance at CT scan and ultrasonography, it did not show any uptake after 75Se-Seleniumcholesterol or 131I-Metaiodobenzyl-guanidine. The patient was also affected by mild hyperprolactinemia caused a small pituitary adenoma. After selective venography, she underwent the surgical removal of the left adrenal gland with its mass, which showed a hystological picture of adrenal adenoma. The postoperative course was clinically normal. The interest of this case resides: in the dimensions of the adrenal tumor (the presence of adenomas greater than 6 cm diameter is extremely rare); in the radiographic findings, showing a cystic appearance, probably related to a fluid component, in the association of adrenal and pituitary adenoma, as a possible variant of multiple endocrine neoplasia (MEN) of type I.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗

PubMed1993

[Reevaluation of the I-dopa test in acromegaly: anatomo-clinical and prognostic correlations].

It is known that in acromegalic patients the GH secretion exhibits a pattern of response to various stimuli that differs from that observed in normal subjects. We have evaluated the paradoxical GH response to 1-Dopa in acromegaly, in order to clarify the relationships between this datum and the tumour size, the basal GH secretion, the GH response to TRH and the long-term prognosis. MATERIALS AND METHODS. 34 acromegalic patients, 12 men and 22 women, aged 35-70 yr, participated in this study. They were divided in 4 classes, according to Hardy's classification of pituitary neoplasias: (1) intrasellar microadenomas, < 10 mm (n = 8); (2) intrasellar macroadenomas, > 10 mm (n = 14); 3) adenomas with local expansion (n = 9); (4) adenomas with extrasellar expansion (n = 3). All patients underwent a 1-Dopa-test; 18 of them underwent a TRH-test. Basal postoperative GH and basal pre- and postoperative PRL levels were also determined. RESULTS. The basal preoperative GH values in all patients ranged between 16 and 278 ng/ml. 22 patients showed a paradoxical response to 1-Dopa, 12 were non-responders. The following results were observed in the different classes: [table: see text] Moreover, 10 subjects (56%) were TRH-responders (9 of them were also 1-Dopa-responders, 1 was non-responder) and 8 were TRH non responders (6 were 1-Dopa non-responders, 2 were 1-Dopa responders). Basal postoperative GH values were > 5 in 17 1-Dopa responders and in 9 non responders. Basal preoperative PRL levels were > 25 ng/ml in 7 1-Dopa responders and in 2 non responders. After surgery, basal PRL became normal in 5 responder patients. DISCUSSION. In a previous work we have correlated the paradoxical GH response to TRH with tumour size and GH levels, observing a higher percentage of paradoxical response in patients in class I and II and, postoperatively, lower GH levels in preoperative TRH responders. So, we have underlined the good prognostic feature of a preoperative paradoxical response. In this paper we have evaluated the paradoxical GH response to 1-Dopa in the different Hardy's classes and compared it with the GH levels and the GH response to TRH. The results show that a paradoxical response can be observed more frequently in small (class I) adenomas than in greater size ones, and in presence of lower GH basal levels. Moreover, a concordance between 1-Dopa and TRH tests can be observed. CONCLUSIONS. The results clearly indicate that the responses to dynamic GH tests should be evaluated considering the anatomic characteristics of the neoplasias. It could be suggested that the paradoxical response can be expressed only when hypothalamus-pituitary interactions are intact.

Acromegaly↗

PubMed1992

Influence of pyridostigmine on growth hormone (GH) response to GH-releasing hormone pre- and postprandially in normal and obese subjects.

The effect of pyridostigmine (PYR), an inhibitor of acetylcholinesterase, on the GH response to GH-releasing hormone (GHRH) before and after a meal was studied in 14 normal subjects (8 females and 6 males) and 21 obese subjects (13 females and 8 males). In normal subjects tested in a fasting state, PYR was capable of stimulating GH secretion and increasing the GH response to GHRH. These effects were not apparent after food, suggesting a reduction in cholinergic hypothalamic activity. In obese subjects tested in a fasting state, PYR was ineffective when administered alone. On the contrary, it was able to increase the GH response to GHRH. After food, the augmenting effect of PYR on the GH response to GHRH was not observed, whereas a delayed inhibition of the GH response was found after PYR plus GHRH treatment. Our findings support the hypothesis that cholinergic hypothalamic activity plays a pivotal role in impaired GH regulation and the altered sensitivity of GH secretion to metabolic fuels in obese subjects.

Adult↗

PubMed1992

Calcium antagonists and hormone release. VIII. Effects of verapamil infusion on C-peptide to insulin molar ratio in normal subjects and obese subjects with normal glucose tolerance.

It is known that calcium-antagonist drugs can modify the insulin response to various secretagogues. In order to clarify whether calcium-antagonist effect was directed at the level of pancreatic insulin secretion or hepatic insulin extraction and further investigate the pathogenesis of hyperinsulinemia in obesity, an oral glucose tolerance test (OGTT) was performed in basal conditions and during a Verapamil infusion (VE, 5 mg/h x 3.5 h) in 12 normal subjects and 14 obese patients with normal glucose tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

GH response to GHRH before and after meals at different hours of the day in obese patients.

In normal subjects several factors are involved in the regulation of the GH response to GHRH, such as nutritional status, metabolic fuels and neurotransmitters. We previously have shown a paradoxical increase in the GH response to GHRH after meals in obese patients, in contrast to the blunted GH response observed after feeding in normal subjects. We have further investigated this phenomenon, studying the GH response to GHRH before and after meal at three different hours during the day in 10 obese patients, aged 18-35 yr, in comparison to that in eight normal women, aged 20-35 yr. GHRH was injected in a fasting state or 1 hr after a standard meal (800 KCal). In obese subjects, after food ingestion the peak GH response to GHRH was increased at 0900h and 1300h and was significant when the patients were tested after lunch (1300h). On the contrary, in the evening the GH response to GHRH remained unchanged, both before and after feeding. These data point to an altered sensitivity of GH secretion to metabolic signals in patients with obesity.

Adolescent↗