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Biomedical subjects

A Tofani

Publications and source records attributed to A Tofani.

At least 37 records · Page 2Linked to original sources
PubMed1995

In-111 octreotide scintigraphy in the diagnostic evaluation of en plaque meningioma. A case report.

A 44-year-old woman had a 13-year history of a small bulge of the left frontal region which had increased in size during the last year. At admission, an orange-sized, hard, fixed left frontal mass was found. Magnetic resonance imaging showed hyperostosis in the left frontal region which was causing a skull deformity and marked focal meningeal enhancement. A hyperostotic plaque meningioma was hypothesized. In-111 octreotide scintigraphy confirmed the diagnosis before surgery. In-111 octreotide scintigraphy allows biologic characterization of neoplasms in vivo.

Adult↗
PubMed1995

Somatostatin receptor imaging in CNS tumours using 111In-octreotide.

This study evaluates the in vivo visualization of somatostatin (SS) receptors in central nervous system (CNS) tumours using 111In-octreotide imaging and discusses the clinical implications. Ninety-five patients with histologically confirmed diagnosis of CNS tumours were imaged 2-4 and 24 h after the intravenous injection of 111-185 MBq of 111In-octreotide. An uptake index was computed using tumour/non-tumour ratios evaluated using a standard region-of-interest method. Semi-quantitative immunohistochemical studies of SS binding sites were performed on frozen tumour sections. All meningiomas, most pituitary adenomas and many glial tumours showed a positive scan, whereas all neurinomas, craniopharingiomas and ependymomas had negative receptor scans. Radio-octreotide uptake varied among the SS receptor positive CNS tumours: very intense in meningioma, intermediate in pituitary adenoma and of a low grade in glioma. The results of immunohistochemical studies confirmed the scintigraphic findings in all cases. We believe 111In-octreotide is a suitable radiopharmaceutical for characterizing CNS tumours in vivo as SS receptor positive or negative. This new neuronuclear imaging technique may be useful for differential diagnosis in selected cases, for post-surgical follow-up and in the assessment of differentiation in glial tumours.

Adenoma↗
PubMed1995

111In-octreotide scintigraphy in pituitary adenomas.

This study reports on 111In-octreotide scintigraphy in 20 patients affected with pituitary adenomas, including tracer uptake ratios and in vitro immunohistochemical characterization of the matostatin receptor state. 111In-octreotide uptake was already observed at 4 hours in 7/8 GH-secreting adenomas, in 5/7 non-secreting adenomas and in 1/5 prolactinomas. Concordance between the scan and the histochemical results was observed in all cases. The uptake ratios evaluated at 24 hours ranged from 2.3 to 4.2. The following conclusions were drawn: 1) 111In-octreotide is a suitable tracer to evaluate the somatostatin receptor state of pituitary adenomas; 2) Semi-quantitative measures of tracer uptake can be easily obtained with static planar scanning, but more refined techniques are needed for receptor kinetics evaluation; 3) This nuclear technique is a promising non-invasive tool to identify patients with somatostatin receptor positive pituitary adenomas who might potentially benefit from pre- and/or post-surgery cold octreotide medical treatment.

Adenoma↗
PubMed1994

Thallium-201 scintigraphy and chemotherapeutic response in rhabdomyosarcoma.

Thallium-201 scintigraphy was used to evaluate chemotherapeutic response in a case of rhabdomyosarcoma treated with epirubicin. A scintigraphic semiquantitative index of tumor viability was correlated with MRI and clinical assessment. Both imaging studies were performed before therapy and after treatment involving a cumulative dose of 640 mg/m2 of epirubicin. A very good inverse correlation was observed between Tl-201 uptake and tumor necrosis evaluated by MRI, leading to the conclusion that sequential Tl-201 scintigraphy may have a role not only in delineating the extent of the tumor, but in objectively assessing tumor response to therapeutic interventions. The proposed scintigraphic method is much simpler to perform and less expensive than MRI-derived semiquantitative measurement of tumor necrosis.

Adult↗
PubMed1994

TSH suppression by octreotide in differentiated thyroid carcinoma.

OBJECTIVE: This study evaluates the addition of octreotide and L-thyroxine to shorten the period of exposure to unduly elevated TSH levels in patients with differentiated thyroid carcinoma undergoing total body scan with 131I. DESIGN: Fourteen thyroidectomized patients were studied after total body scan and the restarting of different doses of thyroxine. After one year a second total body scan and a schedule of the same dose of thyroxine combined with octreotide were performed in each subject. PATIENTS: Patients were divided into four groups according to the treatment: seven patients received initially 100 micrograms of L-thyroxine (Group 1) and after 1 year 100 micrograms of L-thyroxine plus 300 micrograms of octreotide/day (Group 3); the other seven received initially 150 micrograms of L-thyroxine (Group 2) and then 150 micrograms of L-thyroxine plus 300 micrograms of octreotide/day (Group 4). MEASUREMENTS: Serum TSH, T3 and T4 were measured on the day of radioiodine administration (day 0) and after 14, 21, 30, 45, 60 and 90 days. RESULTS: Mean basal TSH levels were elevated in all four groups ranging from 104 to 91 mU/I without significant differences. The patterns of TSH inhibition were however different in the four groups studied. TSH remained very elevated for a long time in Group 1 patients: at day 90 the TSH value was still 2.1 +/- 1.2 mU/I (mean +/- SEM). Patients in Groups 2 and 3 showed a similar pattern: TSH was suppressed in 45 days. The most rapid TSH inhibition was observed in Group 4 patients with a mean decrease of 88% in 14 days and complete suppression in 30 days. CONCLUSIONS: TSH suppression by L-thyroxine is very slow and it can be significantly enhanced by combined octreotide administration. Combined therapy is safe and offers an alternative choice when high dosages of L-thyroxine are inappropriate or in conditions of advanced illness.

Adolescent↗
PubMed1993

Somatostatin receptor imaging in small cell lung cancer using 111In-DTPA-octreotide: a preliminary study.

Small cell lung cancer is a common and aggressive disease. Combined multiagent chemotherapy and radiotherapy can improve short-term prognosis, but long-term prognosis remains dim. Somatostatin receptors have been identified on the cellular surface of subsets of this cancer and may be associated with less aggressive evolution. Moreover, medical therapy with somatostatin analogues holds promise for neoplastic growth control. Planar scintigraphy has been performed in 15 patients with histologically proven small cell lung cancer at 4 and 24 h after the intravenous (i.v.) injection of 185 MBq 111In-octreotide (Octreoscan, BYK-Gulden). No short-term adverse effects were recorded; tumour uptake of the radiopharmaceutical was observed in 13 patients at 4 h and in 12 patients at 24 h suggesting more extensive disease than apparent by computed tomography (CT). It is highly likely that the 24 h uptake reflects the presence of somatostatin receptors on the tumour. Previous chemotherapy does not seem to play a key role in tumour visualization. 111In-octreotide is a suitable radiopharmaceutical for in vivo evaluation of somatostatin receptor status of small cell lung cancer. Quantitative scintigraphic methods are needed to investigate nonspecific binding and receptor kinetics.

Aged↗
PubMed1993

Somatostatin receptors in meningiomas: a scintigraphic study using 111In-DTPA-D-Phe-1-octreotide.

111In-octreotide (Octreoscan) planar scintigraphy was performed in 12 patients with suspected meningioma. The scan was positive in 10 patients with meningioma and negative in two patients with acoustic neurinoma assisting in the differential diagnosis. Good quality images were obtained as early as 2 h after injection and there was no increase in diagnostic quality at 24 h. No adverse effects were observed to radiopharmaceutical administration. The following conclusions are drawn: 111In-octreotide is a safe and fast test which can increase the specificity of traditional neuroimaging procedures.

Adolescent↗
PubMed1992

Corticotropin-releasing hormone inhibition of paradoxical growth hormone response to thyrotropin-releasing hormone in insulin-dependent diabetics.

A paradoxical growth hormone (GH) response to thyrotropin-releasing hormone (TRH) has been observed in type 1 diabetic patients and was hypothetically attributed to a reduced hypothalamic somatostatin tone. We have previously reported that corticotropin-releasing hormone (CRH) inhibits GH response to growth hormone-releasing hormone (GHRH) in normal subjects, possibly by an increased release of somatostatin. To study the effect of CRH on anomalous GH response to TRH, we tested with TRH (200 micrograms intravenously [IV]) and CRH (100 micrograms IV) + TRH (200 micrograms IV) 13 patients (six males and seven women) affected by insulin-dependent diabetes mellitus. A paradoxical GH response to TRH was observed in seven of 13 patients, one man and six women. In these subjects, the simultaneous administration of CRH and TRH significantly reduced the GH response to TRH, as assessed by both the maximal GH mean peak +/- SE (2.18 +/- 0.67 v 9.2 +/- 1.26 micrograms/L, P less than 0.005) and the area under the curve (AUC) +/- SE (187 +/- 32 v 567 +/- 35 micrograms.min/L, P less than .001). CRH had no effect on TRH-induced thyroid-stimulating hormone (TSH) release. Our data demonstrate that the paradoxical GH response to TRH in patients with type 1 diabetes mellitus is blocked by CRH administration. This CRH action may be due to an enhanced somatostatin release. Our data also show that exogenous CRH has no effect on TSH response to TRH, thus suggesting the existence of separate pathways in the neuroregulation of GH and TSH secretion.

Adult↗
PubMed1992

Crossed cerebello-cerebral diaschisis: a SPECT study.

A scintigraphic single photon emission computed tomographic (SPECT) evaluation of frontal perfusion alteration was performed in five patients with known cerebellar lesions but with normal supratentorial computed tomographic (CT) or magnetic resonance (MR) scans. A clearly evident asymmetry was found in prefrontal areas in the four subjects with acquired cerebellar damage. The fifth subject, who had congenital left cerebellar hypoplasia, did not show any frontal flow asymmetry. The data support the growing clinical evidence that the cerebellum contributes to the cognitive processes of the frontal lobes and suggest a possible role for SPECT examination in the assessment of functional cognitive impairment in patients with acquired cerebellar lesions.

Adolescent↗
PubMed1992

Effects of sex and age on pyridostigmine potentiation of growth hormone-releasing hormone-induced growth hormone release.

Previous studies have shown that pyridostigmine (PD) is capable of increasing the growth hormone (GH) response to GH-releasing hormone (GHRH) in young healthy subjects. In order to investigate the influence of age and sex on the PD potentiation of GHRH-induced GH release, we have studied the GH response to GHRH (50 micrograms i.v.) 1 h after oral administration of placebo or PD (60 mg) in 8 young healthy men (aged 19-28 years) and 8 age-matched young women (aged 18-25 years) during the follicular phase of the menstrual cycle, as well as in 8 postmenopausal women (aged 57-62 years) and 8 age-matched elderly men (aged 56-64 years). In the same subjects the effect of PD alone (60 mg p.o.) was also studied. Furthermore, in 6 postmenopausal women and 6 elderly men, the effect of a 30-mg PD oral dose on GH secretion and GH response to GHRH was evaluated with a similar protocol. The GH responses (mean +/- SE) to GHRH + placebo were similar in young men (peak 20.1 +/- 2 ng/ml, AUC 1,250 +/- 113 ng/ml/min) and women (peak 29.3 +/- 2.3 ng/ml, AUC 1,769 +/- 305 ng/ml/min). PD 60 mg was capable of significantly increasing the GH response to GHRH in young men (peak 43.5 +/- 5.1 ng/ml, AUC 3,734 +/- 472 ng/ml/min, p less than 0.005) but not in women (peak 39 +/- 2.3 ng/ml, AUC 2,479 +/- 205 ng/ml/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Activation of cholinergic tone by pyridostigmine reverses the inhibitory effect of corticotropin-releasing hormone on the growth hormone-releasing hormone-induced growth hormone secretion.

Previous studies have shown that corticotropin-releasing hormone (CRH) is capable of inhibiting growth hormone (GH) secretion in response to GH-releasing hormone (GHRH). In an attempt to clarify the mechanism of the CRH action, we have studied the effect of enhanced cholinergic tone induced by pyridostigmine on the CRH inhibition of the GH response to GHRH in a group of six normal men and six normal women. All subjects presented a normal GH response to 50 micrograms i.v. GHRH administration (mean peak +/- SEM plasma GH levels 20 +/- 2.9 micrograms/l in men and 28.9 +/- 2.9 micrograms/l in women) with a further significant increase after pyridostigmine pretreatment (60 mg orally given 60 min before GHRH) in men (GH peaks 43.1 +/- 6.9 micrograms/l, p less than 0.005) but not in women (GH peaks 39.2 +/- 3.0 micrograms/l). In the same subjects, peripherally injected CRH (100 micrograms) significantly inhibited the GH response to GHRH (GH peaks 8.1 +/- 0.6 micrograms/l in men, p less than 0.005 and 9.9 +/- 0.7 micrograms/l in women, p less than 0.005). Pyridostigmine (60 mg) given orally at the same time of CRH administration (60 min before GHRH) reversed the CRH inhibition of GHRH-induced GH secretion (GH peaks 35.3 +/- 8.2 micrograms/l in men and 35 +/- 3.3 micrograms/l in women) with a response not significantly different to that seen in the pyridostigmine plus GHRH test. Our data confirm that pyridostigmine is capable of potentiating the GHRH-induced GH release in normal male but not female subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Acute complications in the course of "mild" hyperparathyroidism.

It is generally accepted that some patients affected by mild asymptomatic primary hyperparathyroidism need not be treated with surgery, but may be medically managed without risk. However, our experience regarding 5 of these cases observed in the last two years, suggests a different approach. These patients, initially diagnosed as having mild hyperparathyroidism based on only moderately elevated serum concentrations of calcium and followed medically for years, were referred to us for a sudden worsening of their clinical course. One 35-year-old man presented hemorrhagic gastritis with severe anemia and type II AV block with syncopal attacks. Three women, aged 51, 64 and 65 years, presented with severe hypercalcemia associated with renal failure in two and with marked bone disease in another. In all these cases parathyroid neoplasms were preoperatively localized (by ultrasonography, CT scan and radioactive 201-Tl 99-Tc scan) and surgically removed. Histological examination showed a parathyroid carcinoma in the male patient and single gland enlargements in the three females. A fifth patient, a 65-year-old woman, was referred to us in critical condition: severe hypercalcemia, osteopenia with femur fracture, myocardial infarction and renal failure. She died in a few days, in spite of intensive medical care. These cases suggest that patients with hyperparathyroidism initially diagnosed as "mild" need close medical observation and preferably, in our opinion, should undergo surgery.

Acute Kidney Injury↗
PubMed1991

Influence of naloxone infusion on prolactin and growth hormone response to growth hormone-releasing hormone in anorexia nervosa.

Anorexia nervosa (AN) is frequently associated with anomalies of growth hormone (GH) and prolactin (PRL) secretion. We studied the GH and PRL responses to GHRH1-44 (50 micrograms IV) and the effect of a naloxone infusion (1.6 mg/hr), started 1 hr before GHRH administration, on this response in 12 female patients with AN, aged 15-30 yr, and in seven normal women, aged 19-27 yr, during the follicular phase as controls. In AN, GHRH induced an increase in GH levels similar to that observed in normal subjects. A significant inhibition of the GH response to GHRH was observed during naloxone infusion, similar to the inhibition in normal female subjects during the follicular phase. PRL levels showed a significant increment after GHRH alone and a slight, nonsignificant, PRL increment after GHRH during naloxone infusion in AN patients. In contrast a slight PRL decrease was observed after GHRH, both before and during naloxone infusion, in the normal subjects. Our study demonstrates that endogenous opioids play a role in influencing PRL secretion in patients with AN different from their role in normal subjects.

Adolescent↗
PubMed1991

Sexual dimorphism of pyridostigmine potentiation of growth hormone (GH)-releasing hormone-induced GH release in humans.

Sex differences in the neuroregulation of GH secretion are not now known in humans. To investigate whether activation of cholinergic tone by pyridostigmine could cause a sex-related difference in the pituitary responsiveness to GH-releasing hormone (GHRH), we have studied the GH response to GHRH in 16 normal subjects (8 men and 8 women) tested after oral placebo or different doses of pyridostigmine (30, 60, and 120 mg). Each subject presented a normal response after iv administration of 50 micrograms GHRH and placebo. In men each dose of pyridostigmine induced a significant increase in the GH response to GHRH, as assessed by both the maximal GH peak and the area under GH curve. In women, on the contrary, the GH response to GHRH was not potentiated by pretreatment with pyridostigmine at any given dose. Only five female subjects were tested with 120 mg pyridostigmine because of the severe side-effects of the drug at this dosage. Our present data strongly suggest that in humans there is a sex-related difference in the neuroregulation of GH secretion and this is probably expressed through a different cholinergic tone.

Adult↗
PubMed1990

Corticotropin-releasing hormone inhibition of growth hormone-releasing hormone-induced growth hormone release in man.

Recent studies in the rat have shown that intracerebroventricular administration of CRH inhibited spontaneous pulsatile GH secretion and prevented GH-releasing hormone (GHRH)-induced GH release. We have studied the effect of CRH on GHRH-induced GH release in man. In the first study, CRH was injected iv at three different doses (100, 50, or 25 micrograms) at 0800 h together with 50 micrograms GHRH in six men and six women. In a second study, 100 micrograms CRH were given iv at 0800 h, 1 h before the administration of 50 micrograms GHRH in five men and five women. Each subject demonstrated a normal GH response after the administration of 50 micrograms GHRH plus saline. All doses of CRH administered simultaneously with GHRH significantly inhibited GHRH-induced GH release in women [peak value +/- SE after GHRH plus saline, 28.9 +/- 2.9 micrograms/L; after GHRH plus 100 micrograms CRH, 9.9 +/- 0.7 micrograms/L (P less than 0.001); after GHRH plus 50 micrograms CRH, 8.7 +/- 0.8 micrograms/L (P less than 0.001); after GHRH plus 25 microgram CRH, 9.5 +/- 1.6 microgram/L (P less than 0.001]). In contrast, in men, while a dose of 100 micrograms CRH was capable of suppressing GHRH-induced GH secretion (peak value +/- SE, 8.1 +/- 0.6 vs. 20 +/- 2.9 micrograms/L; P less than 0.001), no inhibition was observed after 50- and 25-micrograms doses. When 100 micrograms CRH were injected 1 h before the administration of 50 micrograms GHRH, it strongly inhibited GHRH-induced GH secretion in both men (peak value +/- SE, 6.2 +/- 2.8 vs. 24.6 +/- 5.9 micrograms/L; P less than 0.02) and women (peak value +/- SE, 14.2 +/- 4.5 vs. 37.8 +/- 6.7 micrograms/L; P less than 0.005), and this inhibition lasted up to 2 h post-CRH administration. These results demonstrate that CRH is capable of inhibiting GHRH-induced GH release in both men and women. Furthermore, the findings suggest that a sexual dimorphism in the neuroregulation of GH secretion may be present in man. In view of the inhibitory action of CRH on GH secretion, simultaneous administration of CRH and GHRH for testing should be avoided in clinical practice.

Adult↗
PubMed1990

[The role of autoimmune mechanisms in the hyperthyroidism-viral hepatitis syndrome: a possible noncausal association. A review of the literature and the authors' own cases].

Several patients with both Basedow-Graves' hyperthyroidism and viral hepatitis were observed and it was hypothesised that this association could be explained by the individual genetic pattern in which an immunological fragility conditioned a predisposition to autoimmune diseases. This paper reports on the cases observed, the patients' histocompatibility antigen profile and the experimental data found in the literature on autoimmune involvement in the two diseases, whose association may not be coincidental.

Antibody Formation↗