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Biomedical subjects

M Giusti

Publications and source records attributed to M Giusti.

At least 163 records · Page 9Linked to original sources

Effect of low-dosage recombinant human growth hormone therapy on pulmonary function in hypopituitary patients with adult-onset growth hormone deficiency.

An impairment of the pulmonary function has been described in adult patients with childhood-onset growth hormone deficiency (GHD). We examined forced vital capacity (FVC), forced expiratory volume (FEV1), total lung capacity (TLC), functional residual capacity (FRC), residual volume (VR) and the index of inspiratory strength, middle tidal volume and tidal inspiratory time ratio (TV/I), in 29 patients with adult-onset GHD. Data were compared with those obtained in 46 healthy control subjects. Only the FEV1/FVC ratio was statistically different (p = 0.04) between the two groups of subjects. In a group of 15 GHD patients low dosages (0.5-1 IU/day s.c., bedtime) of recombinant human GH (rh-GH; n. = 8 subjects) or placebo (n. = 7) were given at random for a 6-month period. A significant increase in IGF-I levels was noted in the rh-GH-treated group (p = 0.04) but not in the placebo group. After the 6-month period no statistically significant changes in pulmonary function were found between the rh-GH-treated and placebo-treated GHD patients. This study shows that adult-onset GHD patients suffer from minimal impairment of pulmonary function. Low rh-GH dosages able to induce an increase in IGF-I levels do not improve pulmonary function. The effect of rh-GH on respiratory muscle strength could be related to the age at which GHD diagnosis is made, or induced only by high rh-GH dosages given for a long time.

Adult↗

Immunoreactive and bioactive LH release from pituitaries of intact or castrated male rats: effect of in vitro GnRH and KCl administration.

The in vitro immunoreactive (i-LH) and bioactive (b-LH) LH release from hemipituitaries of intact adult male rats (INT) or rats castrated 7 days earlier (CAS) was studied. Hemipituitaries were incubated for 30 min (time 1) plus an additional 30 min (time 2) with GnRH (10 nM) and/or KCl (50 mM), according to one of the following protocols: media alone (C), KCl+KCl (K/K), GnRH+GnRH (G/G), KCl+GnRH (K/G), GnRH+KCl (G/K). All of the hemipituitaries were further incubated in media alone for 120 min (time 3). I-LH, b-LH and i-FSH were assayed on the media. In both models, the highest bioactive:immunoactive (b/i) ratio was noted during time 1; however, CAS always secreted more b-LH than INT at any given time of the study. In INT, GnRH--but not KCl--administration during time 2 resulted in blunted i-LH. During the same time, the b/i ratios decreased in all groups but G/K. LH secretion recovered during time 3 in all groups. In CAS, i-LH levels comparable to those of time 1 were sustained by either stimulus during time 2, while the b/i ratios were markedly decreased. LH secretion recovered in the K/K group during time 3. These results suggest that: 1) promptly releasable pools of b-LH are available in both models; 2) CAS always secrete more b-LH; 3) in INT, desensitization occurs involving parallel changes in both i-LH and b-LH, while changes in b-LH rather than i-LH are noted in CAS; 4) prolonged KCl administration might play a role in new gonadotropin synthesis and/or release.

Animals↗

Twenty-four hour profile of integrated TSH concentration in puberty.

The 24-h pattern of integrated serum TSH concentrations has been investigated in 12 healthy adult males and 14 pubertal boys by means of continuous blood flow sampling. For every subject the integrated values and the mean concentrations, corresponding to the entire 24 hours, to the daytime (08:00-20:00) and to the nighttime (20:00-08:00) were calculated. A circadian rhythmicity has been shown in boys, as well as in adults. The mean TSH concentrations were significantly higher in boys with respect to adults. The nyctohemeral maximum was mostly recorded in pubertal boys after sleep and in adults before the onset of sleep. Mean and integrated concentrations corresponding to the nighttime period were significantly higher than those corresponding to the daytime in both groups. In conclusion, the 24-h TSH secretion seems different in boys with respect to adults both in the increased concentrations and in the time (generally after the onset of sleep) of the maximum.

Adolescent↗

Single-dose ritanserin and alcohol in healthy volunteers: a placebo-controlled trial.

A double blind cross-over design trial was carried out to investigate the effect of simultaneous administration of alcohol (0.5 g/kg) and ritanserin (10 mg) on biological and behavioral functioning. Twenty healthy volunteers were selected to participate in the study. To assess the effect of treatments the following evaluations were performed: psychomotor tests, vital signs, intoxication, euphoria, and mood. In addition, ritanserin and alcohol plasma concentration were measured. Psychomotor performance and vital signs during the ritanserin session did not differ significantly from the placebo session. Similar results were obtained in regard to alcohol intoxication, euphoria, and mood, except for tiredness and alertness, which were significantly different compared to placebo. Differences in blood alcohol concentration between the ritanserin and the placebo sessions did not attain significance. Plasma ritanserin concentration was 143 ng/ml 1 h after alcohol administration and decayed to 53 ng/ml 6 h after alcohol consumption in the active treatment session. Our findings tend to indicate that ritanserin neither enhances the central nervous system depressant effect of alcohol nor produces a pharmacokinetic interaction during acute alcohol ingestion.

Adult↗

Preliminary study of sentinel node identification with 99mTc colloid and blue dye in patients with endometrial cancer.

AIMS AND BACKGROUND: Intraoperative lymphatic mapping and sentinel node (SLN) biopsy have generated a tremendous amount of interest and are already established as part of the standard practice in the surgical management of breast cancer and melanoma. To reduce extensive radical procedures and decrease the morbidity in the treatment of gynecologic malignancies, much effort is being made to use less aggressive interventions. The purpose of our study was to determine the feasibility of SLN mapping in a group of patients with endometrial cancer at early stages. METHOD AND STUDY DESIGN: Between September 2000 and May 2001 11 patients with endometrial cancer FIGO stage Ib (n = 10) and IIa (n = 1) underwent laparoscopic SNL detection during laparoscopy-assisted vaginal hysterectomy with bilateral salpingo-oophorectomy and bilateral systematic pelvic lymphadenectomy. Radioactive isotope injection was performed 24 hours before surgery and blue dye injection was performed just before surgery in the cervix at 3,6, 9 and 12 hours. A 350 mm laparoscopic gamma scintyprobe MR 100 type 11, 99mTc settled (Pol Hi Tech), was used intraoperatively for SLN detection. RESULTS: Seventeen (17) SLNs were detected with lymphoscintigraphy (six bilateral and five unilateral). At laparoscopic surgery we found the same locations belonging at internal iliac lymph nodes (the so-called Lebeuf-Godard area, lateral to the inferior vesical artery, ventral to the origin of the uterine artery and medial or caudal to the external iliac vein). Fourteen (14) SLNs were negative on histological analysis and three were positive for micrometastases (mean SLN sections = 60). All other pelvic lymph nodes were negative at histological analysis. The same SLN locations detected with the gamma scintyprobe were observed at laparoscopy after patent blue dye injection. CONCLUSIONS: Our preliminary data suggest that combined 99mTc-labeled colloid and vital blue-dye techniques are feasible for SLA detection in endometrial cancer; they represent a very promising tool to transform the management of early-stage endometrial cancer. The clinical validity of this combined technique should be evaluated prospectively.

Adult↗

Nitric oxide biphasically modulates GH secretion in cultured cells of GH-secreting human pituitary adenomas.

BACKGROUND: Nitric oxide (NO) biphasically modulates osteoclast function, sperm motility and testosterone production by exerting a positive effect at low concentrations and a negative effect at high concentrations. In this study the effect due to administration of four NO-donors, each releasing an individual amount of NO, was studied on GH secretion from human adenomatous GH-secreting cells. METHODS: Sodium nitroprusside (SNP), diethylenetriamine NO adduct (DETA/NO), diethylamine/NO complex sodium salt (DEA/NO), and S-nitroso-N-acetylpenicillamine (SNAP) were administered at a concentration of 10-4 M to cells isolated after transsphenoidal adenomectomy from five acromegalic patients. RESULTS: SNP significantly (p < 0.01) increased GH secretion, while the other NO donors inhibited GH secretion in comparision with the amount of GH spontaneously released by unstimulated cells. Each drug showed an individual degree of inhibitory potency: DEA/NO > DETA/NO > SNAP. Nitrite accumulation in the media was measured as a marker of NO released by each individual drug and was found to be different for each drug (DEA/NO > DETA/NO > SNAP > SNP). A negative correlation (R = -0.93; p < 0.05) was found between nitrite release and GH secretion induced by each drug. CONCLUSIONS: These data show that low and quasi-physiological levels of NO, such as those released by SNP, stimulate GH secretion, while high NO levels, such as those released by the other NO-donors, inhibit GH secretion. Thus, NO is shown to be able to modulate GH secretion in a dose-dependent manner in GH adenomatous cells from human pituitary adenomas.

Adenoma↗

[Long-term treatment of central diabetes insipidus with oral DDAVP].

Clinical use of the DDAVP (1-Deamino-8-D-Arginine Vasopressin) is now the first choice in treatment of Central Diabetes Insipidus. It is an analogue of Vasopressin with a higher antidiuretic potency, less vasopressor activity, and a longer duration of action. This drug still presents some problems of administration route. A lot of studies were published about different administration routes of DDAVP: sublingual tablets, parenteral solution, nose spray and suction de-epithelialized skin. Some authors have utilized the oral route (solution or tablets) with good results in short-term treatment. We think the formulation in tablets of DDAVP is an efficacious support of the therapy in this disease also for long-treatment. In our study 3 patients with Central Diabetes Insipidus (aged 22-56; 2 idiopathic and 1 post-surgery) previously treated with DDAVP nasal solution (10 micrograms/day; 36-156 months), have been submitted to a chronic treatment with DDAVP tablets for a period of 24-36 months. The DDAVP tables were administered at the dosage of 400-600 micrograms/day in 2-3 administrations. The patients were studied at intervals of 3-6 months, and on each occasion full blood count, glucose, azotaemia, creatinine, liver function tests, electrolytes, urine volume, density and osmolality were estimated. The long-treatment with oral DDAVP was able to keep a good control of the disease in all patients. In case 1 we had a significant reduction of urine volume (p < 0.01) and a significant increase (p < 0.01) of urine osmolality in comparison with previous treatment with nasal solution; in case 2 and 3 no significant changes were observed. No side effects were noted during this study. The drug has been well tolerated and the compliance of patients was better during oral DDAVP than nasal solution. In our opinion the oral DDAVP is an effective and safe solution for the treatment of Central Diabetes Insipidus, and give to the patients a better quality of life in comparison to the nasal solution.

Administration, Intranasal↗

[Treatment of central diabetes insipidus using oral DDAVP. Comparison with intranasal treatment].

The Authors have done a clinical study on the efficacy of desmopressin (DDAVP) tablets in the treatment of central diabetes insipidus in 13 patients who were previously treated with intranasal DDAVP. A comparison has been made between peroral and intranasal forms of DDAVP measuring the urinary volume and osmolarity daily. The right dosage of DDAVP tablets was between 150 and 600 micrograms/die. The patients showed very good compliance during the 4 weeks of treatment with DDAVP.

Administration, Intranasal↗

LHRH-induced gonadotropin release before and after short-term therapy with cabergoline in hyperprolactinaemic patients.

Cabergoline is a new ergot derivative with long-lasting PRL lowering effect. Basal and LHRH stimulated (50 micrograms i.v.) gonadotropin secretion was evaluated before and during cabergoline treatment (0.5-2 mg/week) in 28 women with pathological hyperprolactinaemia. After 4 weeks, PRL and E2 were significantly (p less than 0.01) reduced and increased, respectively. Basal LH and FSH levels did not change. Both LH (p less than 0.05) and FSH (p less than 0.02) responsiveness to LHRH was decreased from the former to the latter test. The study underlines drug-induced variations in gonadotropin responsiveness to LHRH which are probably due to variations in the steroid milieu.

Adolescent↗