Anna Tofani

Corticotropin-releasing hormone inhibition of gonadotropin secretion during the menstrual cycle

To determine whether corticotropin-releasing hormone (CRH) exerts an inhibitory action on gonadotropin secretion in normal fertile women, the effects of CRH on luteinizing hormone (LH), follicle-stimulating hormone (FSH), and cortisol secretion were studied during the menstrual cycle. CRH had no effect on LH release during the midfollicular phase of the cycle. By contrast, IV injection of 100 micrograms CRH elicited significant decreases in LH concentrations during late follicular (-50%) and midluteal (-52%) phases of the cycle. LH concentrations decreased during the four-hours following injection of CRH and returned to those observed during the control period five hours after injection. Similarly, CRH elicited a significant decrease in FSH secretion during the midluteal phase of the cycle. CRH injection induced an increase in cortisol release during all phases of the cycle. These data demonstrate that exogenous CRH administration results in inhibition of gonadotropin secretion in late follicular and midluteal phases of the cycle. These results suggest that elevated endogenous CRH levels resulting in increased cortisol secretion could contribute to decreased gonadotropin secretion and, thus, disruption of reproductive function during stressful conditions in women.

Clinical relevance of radionuclide angiography and antimyosin immunoscintigraphy for risk assessment in epirubicin cardiotoxicity

BackgroundCardiotoxicity is the major limiting factor in anthracycline chemotherapy of advanced neoplastic disease. Epirubicin shows a more favorable therapeutic index than does doxorubicin, but it is still cardiotoxic. Limited data regarding epirubicin cardiotoxicity are available, and suggested guidelines for doxorubicin with left ventricular ejection fraction (LVEF) measurement may not be empirically useful for epirubicin therapy. This study evaluates the diagnostic role of antimyosin immunoscintigraphy for early identification of patients at risk for late pump dysfunction from cardiotoxicity induced by high-dose administration of epirubicin up to high cumulative dosages.Methods and ResultsChemotherapy with epirubicin was administered to 36 patients with cancer at a dosing rate of 160 mg/m2 as a bolus injection every 21 days to a cumulative dosage heart-lung ratio (HLR) measurements were performed before chemotherapy, at intermediate cumulative epirubicin dosages, at the end of treatment, and during the follow-up. LVEF decreased significantly at the end of the treatment and after therapy discontinuation. HLR values were significantly increased at intermediate epirubicin dosage levels and continued to increase to the end of the treatment but thereafter remained substantially unmodified for 3 to 6 months after therapy discontinuation. A value of HLR>1.85 at intermediate epirubicin dosage level showed a sensitivity of 95% and a specificity of 57% as a predictor of late LVEF impairment.ConclusionsLVEF appears more useful at high cumulative dosages and during follow-up to monitor late pump dysfunction, whereas HLR may be effective during the early phase of the therapy in determining which patients are at risk for development of late cardiac dysfunction.

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.

Sex-related naloxone influence on growth hormone-releasing hormone-induced growth hormone secretion in normal subjects

The effect of opiate-receptor antagonist naloxone on growth hormone (GH) release after growth hormone-releasing hormone (GHRH) 1-44 administration was investigated in ten normal men and 18 normal women during different phases of their menstrual cycle. Naloxone was infused at a rate of 1.6 mg/h in women and 1.6- and 3.2 mg/h in men, starting one hour before GHRH administration (50 micrograms iv as a bolus). On different day sessions, naloxone, GHRH, or saline were administered as controls. Naloxone infusion reduced the GHRH-induced GH release in normal women. The mean % inhibition of peak GH response was 83% during follicular phase, 46.5% during periovulatory phase, and 77.6% during luteal phase. On the contrary, in normal men, both doses of naloxone infusion were ineffective in blunting the GH response to GHRH. Our studies indicate that naloxone infusion was capable of inhibiting GH release induced by direct stimulation with GHRH in normal women, suggesting an opiate-antagonist action at the anterior pituitary level. The absence of such an effect in normal men strongly indicates a sex dependence of naloxone effects and suggests a role of the sexual steroid environment in opioid modulation of pituitary hormone secretion.

S-100 and NSE as serum markers in melanoma.

S-100 protein and neuron-specific enolase (NSE) have recently been proposed as serum markers for melanoma. In this study NSE and S-100 serum levels were assayed by commercial IRMA methods in 53 patients with melanoma. The overall prevalence of abnormal marker levels was similar for NSE (26%) and S-100 (30%). The 24 patients in stages I and II had uniformly normal S-100 levels, but abnormal NSE levels were observed in 3 out of the 12 patients in stage II (33%) and in 1 out of 12 in stage I. NSE appears thus to be the marker of choice in the early stages, where its increase points to disease progression. In patients in stages III and IV the prevalence of abnormal values was 34% for NSE and 55% for S-100 (p = < 0.05). In the latter group diagnostic sensitivity increased to 62% if isolated elevation of each marker was considered. In patients with advanced stage disease, both NSE and S-100 should be assayed.

Naloxone inhibition of postprandial growth hormone releasing hormone-induced growth hormone release in obesity

The effects of opiate receptor antagonist naloxone on growth hormone (GH) release after growth hormone-releasing hormone (GHRH) administration were investigated, before or after feeding, at 13.00 h, in 20 obese women and in 10 normal women. When GHRH was administered to obese women before a meal at lunch time, the mean peak plasma GH levels were very low, while plasma GH responses significantly increased after feeding. Naloxone, infused at a rate of 1.6 mg/h starting 1 h before GHRH administration (50 micrograms i.v. as a bolus), was capable of inhibiting GH release induced by administration of GHRH after feeding. On the contrary, naloxone did not induce significant variations on the fasting GHRH-induced GH release. In normal women, naloxone did not significantly modify the GH response to GHRH, both before and after lunch. The inhibitory effect of naloxone indicates that in obese women there is an increased opioid activity, which could represent an abnormal response of the gastrointestinal tract to food ingestion.

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.

Radioiodine-induced changes in lymphocyte subsets in patients with differentiated thyroid carcinoma.

Abstract.This study evaluated changes in lymphocyte subsets in patients with thyroid carcinoma who received iodine-131 for diagnostic and therapeutic purposes. Twenty thyroid cancer patients were entered in the study after total thyroidectomy: ten patients (group A) underwent whole-body scintigraphy with 185 MBq of 131I and the other ten (group B) received 3700 MBq of 131I therapy. All patients were in a hypothyroid state at the time of administration of 131I and started l-thyroxine 150 µg/day 3 days after 131I administration. Free and bound triiodothyronine and thyroxine, thyroid-stimulating hormone, thyroglobulin, thyroglobulin antibodies, thyroid peroxidase/microsomal antibodies, white blood cell, lymphocyte counts and lymphocyte subsets were serially determined at baseline and at days 2, 7, 15, 30 and 60 after 131I administration. Twenty healthy age- and sex-matched individuals were used as a reference population for lymphocyte subset values. In group A only a reduction in NK cells at days 7 (P=0.043) and 15 (P=0.037) was observed. In group B, patients showed a delayed reduction in the total lymphocyte count at days 15, 30 and 60 (P=0.008, 0.004 and 0.018, respectively), and a decrease in B cells throughout the study (at days 7, 15, 30 and 60: P=0.006, 0.0017, 0.0017 and 0.0017 respectively). A transient decrease in NK cells was observed at days 15 (P=0.025) and 30 (P=0.008). Among T cells, the helper phenotype (CD4+) was mainly affected, resulting in a reduction in the CD4+/CD8+ ratio at day 60 (P=0.046). Comparing the two groups, the numbers of B lymphocytes at day 30 (P=0.023) and NK cells at days 2 (P=0.037) and 30 (P=0.023) were significantly lower in group B. Neither group showed any clinical sign of immunosuppression during the follow-up period. In patients with thyroid cancer the sensitivity of lymphocytes to the effects of 131I administered for diagnostic or therapeutic purposes depends upon lymphocyte phenotype and 131I activity. NK cells are the most radiosensitive cells, being reduced even by low 131I activity. At higher activity all subtypes show a reduction, which is more marked and prolonged for B lymphocytes and, to a lesser extent, for T-helper lymphocytes. These changes do not result in clinically relevant immunosuppression.

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 TI-201 uptake and tumor necrosis evaluated by MRI, leading to the conclusion that sequential TI-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.

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.