Search PubMed⌕ Search

Biomedical subjects

G Rossi

Publications and source records attributed to G Rossi.

At least 19 recordsLinked to original sources
PubMed1992

The receptor for the plasminogen activator of urokinase type is up-regulated in transformed rat thyroid cells.

Five rat thyroid cell lines were tested for the expression of the cell surface receptor for urokinase type plasminogen activator (uPA). All tested lines were found to bind uPA, but transformed 1-5G and Ki-Mol cells, which are also high uPA producers, bound at least ten times more uPA, as compared to non-producers, 'normal' TL5 cells. Moreover, it was possible to remove membrane-bound uPA by treating the cells with phosphatidylinositol-specific phospholipase C, suggesting that rat uPAR, like its human counterpart, is linked to the membrane by a glucosyl-phosphatidylinositol anchor. The specificity of the binding was tested by competition with three different synthetic peptides corresponding to amino acids 14-37 of human, rat and mouse uPA. The results indicate also that the receptor binding region of rat uPA is located within the growth factor domain of the molecule and that its expression may be dependent on the transformed state of the cells.

Amino Acid Sequence↗
PubMed1992

Conditioned place preference from ventral tegmental injection of morphine in neonatal rats.

When given peripherally, morphine produces a conditioned place preference (CPP) in adult and infant rats. In adults, morphine injected into the ventral tegmental area (VTA) is reinforcing and likely acts by activating mesolimbic dopamine neurons. Little is known of the neurobiological basis of reinforcement in the immature animal. To test whether the neural substrate of drug reinforcement is similar in adults and infants, 4-day-old pups were injected with one of 4 doses (0.05, 0.15, 0.45, 1.35 micrograms) of morphine or the vehicle directly into the VTA and were immediately confined to an odor-cued environment for 30 min. They were then tested for a preference between the cued environment and unadulterated wood shavings. The low dose of morphine (0.05 micrograms) injected into the VTA significantly increased duration of time spent in the conditioned environment, demonstrating conditioned preference for the conditioned area over the unscented area; the most effective injection sites were directly into the VTA. Stimulation of structures just outside the VTA, and higher doses of morphine were ineffective. On the basis of these findings we conclude that the neural substrates of reward in the neonate are similar to those of the adult.

Animals↗
PubMed1992

Surveillance and treatment of liver transplant recipients for candidiasis and aspergillosis.

Between June 1988 and May 1991 88 orthotopic liver transplants and 1 liver and pancreas transplant were performed at the Liver Transplantation Department of the Ospedale Maggiore of Milan. All the patients underwent mycological surveillance and received antifungal prophylaxis with oral amphotericin B (6000 mg/day) or oral or intravenous fluconazole (200 mg/day) from the time of their transplant. The incidence of Candida colonization was 67%. Fluconazole was superior to oral amphotericin B in the treatment of C. albicans colonization (9/9 vs 6/15), but less effective in the treatment of colonization by other Candida spp. (0/3 vs 3/3). Deep-seated candidiasis developed in 5 patients, caused by C. albicans in 4 cases and C. krusei in 1. C. albicans infection resolved rapidly with fluconazole in 2 subjects, with intravenous amphotericin B alone in 1, and with amphotericin B plus flucytosine in the other. On the contrary, C. krusei infection did not respond to treatment with amphotericin B combined with flucytosine. Aspergillosis was diagnosed in 11 patients, of whom 4 died from invasive aspergillosis, despite 15 and 26 days of amphotericin B treatment in 2. In another patient invasive aspergillosis, diagnosed a few hours before retransplantation, improved with liposomal amphotericin B, but this man died from cytomegalovirus infection one month later. Aspergillosis was eradicated by itraconazole in 4 other patients and by topical amphotericin B in 2 whose infection was localized to surgical wound.

Adolescent↗
PubMed1992

Selective arterial embolization in the treatment of aneurysmal bone cyst and angioma of bone.

Nineteen aneurysmal bone cysts and five angiomas of bone were treated by selective arterial embolization. The median follow-up was 22 months. In 17 patients healing occurred with complete relief of symptoms; in 11 of these almost complete ossification of the lesion resulted. In the remaining cases, little or no ossification was apparent but ossification may take 1 year or more to occur. No recurrence was observed in any of these cases. Recurrence occurred only in two cases. In one, growth of the recurrence stopped after a second embolization, and the X-rays showed no change. Selective arterial embolization represents a treatment of choice in aneurysmal bone cyst and angioma of bone especially of the spine, sacrum, or pelvis. In these sites embolization replaces surgery which might be hazardous due to intraoperative bleeding.

Adolescent↗
PubMed1992

Alternating hemiplegia of childhood: case report.

We report the case of a 3 1/2 year old girl who had had attacks of alternating hemiplegia from the age of 6 months. Peculiar features from the etiopathogenetic angle seem to be the presence of a ring of mild stenosis of the vertebral artery on the right side, the influence of the upright posture on the onset of the attacks and perhaps also of variations in atmospheric pressure. The only drug that had some effect was flunarizine. Phenobartbital, haloperidol and nadolol had no appreciable effect.

Child, Preschool↗
PubMed1992

Phenobarbital in the prophylaxis of late posttraumatic seizures.

390 patients with severe head injuries were treated with phenobarbital (PB) orally for a period of 12 months in order to determine whether this drug could reduce the incidence of posttraumatic epilepsy (PTE). An intramuscular PB dose of 2.5-3 mg/kg body weight per day was administered within 24 hours after the trauma; after 5 days, or longer if the coma persisted, the drug was administered orally. Maintenance dosage adjustments, when necessary, were based on serial plasma concentrations of the drug, sustained at between 5 and 30 micrograms/ml. 293 patients completed the study. 66% of these presented one risk factor, while 34% presented two or more. 6 patients (2.04%) had at least one seizure during the twelve months. Plasma drug levels at the time of the seizure, with one exception of 15 micrograms/ml, ranged from 20 to 28 micrograms/ml. The results of the study indicate that PB administered during the first twelve months after the trauma, even at relatively low doses, can have a prophylactic effect on PTE.

Adolescent↗
PubMed1992

Metachromatic leukodystrophy: on an atypical case.

We describe an atypical case of juvenile metachromatic leukodystrophy. Motor conduction velocity was still within the normal range 3 years after clinical onset, in contrast to what is commonly found in this disease. Another unusual feature is the normal level of CSF protein. These data are discussed in the light of the sural nerve biopsy findings, which revealed only slight impairment.

Child↗
PubMed1992

Luteinizing hormone response to an intravenous infusion of substance P in normal men.

The effect of synthetic substance P (SP), infused intravenously in doses of 0.5, 1.0, or 1.5 pmol/kg-1/min-1 for 60 minutes, on gonadotropin secretion was evaluated in seven healthy men. SP tests and a control test with normal saline were randomly performed at weekly intervals. During the tests, SP infusion did not produce untoward side effects or changes in blood pressure. Plasma testosterone concentrations were normal in all subjects and remained unmodified during all tests, regardless of the infused dose of SP. Plasma luteinizing hormone (LH) levels were not modified when either normal saline or the lowest dose of SP were infused, whereas they were significantly increased in a dose-dependent fashion when larger amounts of SP were administered. In contrast, plasma follicle-stimulating hormone (FSH) concentrations did not change significantly during any test. These data demonstrate for the first time in normal men that the systemic infusion of SP stimulates LH release, without modifications of FSH secretion.

Adult↗
PubMed1992

Development of a Langerhans cell phenotype from peripheral blood monocytes.

Epidermal Langerhans cells (ELC) are definitively primed to differentiate into dendritic cells (DC). It is unknown at what stage of monocyte development this priming occurs. In a culture system characterized by low paracrine stimulation, i.e. Iscove's modified Dulbecco medium (IMDM) with 2% FCS, we tested the ability of peripheral blood monocytes to turn to the route of the LC-DC lineage. In this system monocytes did not develop significant yeast cell phagocytosis, although mannose receptors were available. However, they became strong stimulators of mannan specific T cell proliferation. Phenotype development was analysed by flow cytometry using the monoclonal antibodies OKT6 (CD1a), IOT2 (HLA-DR), IOM2 (CD14) and the ligand Man-BSA-FITC. CD1a was the first marker which distinguished cultured monocytes from developing macrophages, obtained by addition of 8% human serum. Like cord blood Langerhans cells (CBLC) they internalized OKT6 in deep coated pits. They maintained a phenotype of monocyte derived Langerhans cells (MoLC) during eight days of in vitro culture, expressing CD1a, mannose receptors and HLA-DR and decreasing CD14, if left in their own conditioned medium. MoLC could be converted into macrophages by addition of human serum only within the first four days in vitro. Our data suggest that monocytes acquire an LC phenotype by autocrine stimulation.

Antigens, CD↗
PubMed1992

Aggressive treatment of intrathoracic recurrences of thymoma.

Between 1974 and 1988, 21 patients with intrathoracic recurrences of thymoma received radiotherapy with radical intent; surgery was always attempted when considered feasible: 11 patients were partially (6 cases) or totally (5 cases) resected before irradiation, while in the other 10 radiotherapy was the only treatment. In 7 cases the recurrence was confined to the anterior mediastinum, 9 had pleural nodules without mediastinal lesions and 5 had both mediastinal and pleural lesions. Mediastinal recurrences were treated by opposed parallel mediastinal fields with 2/3 of the dose delivered through the anterior port: doses ranged between 38 and 44 Gy; a boost of 10-16 Gy was given in patients not radically resected. Pleural nodules were treated with a variety of techniques according to the extent of the lesions. The 7-year survival of the whole group was 70%; 5 patients died: 4 with intrathoracic progression and one with distant metastases. The survival was 74% in the 11 patients having received surgery, either radical or subtotal, and 65% in the 10 patients treated with radiotherapy alone: the difference is not significant. Patients with Karnofsky index greater than 70 had a significantly better survival (100%, versus 28%, p = 0.0015). This is a selected series of patients presenting recurrences still amenable to a radical treatment either by surgery and radiotherapy or by radiotherapy alone: the results confirm that an aggressive approach is warranted in patients in good general conditions with recurrences confined to the mediastinum and/or 1 hemithorax.

Adult↗
PubMed1992

Abnormal growth hormone and cortisol, but not thyroid-stimulating hormone, responses to an intravenous glucose tolerance test in normal-weight, bulimic women.

Abnormal growth hormone (GH) and adrenocorticotropic hormone (ACTH)/cortisol secretory patterns in response to a glucose load have been observed in underweight anorectic women. The present study was performed in an attempt to establish whether changes in the hypothalamic/pituitary sensitivity to hyperglycemia occur in bulimia in the absence of weight disturbance. Therefore, serum GH, plasma cortisol, and plasma insulin concentrations were measured in eight women with normal weight bulimia and in eight normal women during an intravenous glucose (0.33 g/kg as an IV bolus) tolerance test (IGTT). In addition, since abnormal pituitary hormone responses to a glucose load might reflect alterations in somatostatin (SRIH) release, TSH secretion also was measured, in view of its sensitivity to SRIH inhibition. Both GH and cortisol levels progressively and significantly declined during IGTT in the normal subjects. In the bulimic women, cortisol levels remained unchanged, whereas GH concentrations rose significantly after glucose injection. Plasma cortisol and serum GH levels were significantly higher in the bulimic than in the control subjects. No significant differences between groups were observed in hyperglycemia-induced insulin increments or in TSH decrements. These data indicate that an altered sensitivity to hyperglycemia affects the hypothalamic/pituitary centers controlling the secretion of the counterregulatory hormones GH and ACTH/cortisol in bulimia nervosa. The lack of a simultaneous change in the TSH secretory pattern argues against a possible involvement of SRIH in the pathophysiology of this disorder.

Adult↗
PubMed1992

Different effects of baclofen on LH and cortisol responses to naloxone in normal men.

The possible involvement of GABAergic B receptors in the control of LH and ACTH/cortisol secretion in response to naloxone was evaluated in seven normal men. Subjects were tested with naloxone (4 mg IV bolus plus 10 mg infused over 2 hr) with or without previous treatment with the gamma-aminobutyric acid (GABA)-ergic B receptor agonist, baclofen (5, 10 or 15 mg PO 30 min before naloxone). In additional experiments, six normal men were tested with 15 mg baclofen or placebo 30 min before a 2-hr infusion of normal saline. Plasma cortisol levels rose 70% in response to naloxone. The naloxone-induced cortisol rise was not modified by pretreatment with baclofen (5, 10 or 15 mg). Plasma LH concentrations rose 66% in response to naloxone. When the lowest dose of baclofen (5 mg) was administered, the LH response to naloxone remained unchanged. In contrast, 10 mg baclofen produced a significant reduction, and 15 mg baclofen completely abolished the naloxone-induced LH rise. The administration of baclofen or placebo alone did not change basal plasma levels of cortisol and LH. These data suggest that, in normal men, GABA B receptors participate in the endogenous opioidergic control of LH secretion, but not of ACTH/cortisol secretion.

Adrenocorticotropic Hormone↗
PubMed1992

Influence of basal androgen levels in euandrogenic women on glucose homeostasis.

OBJECTIVE: To evaluate possible relationships between insulin action and the normal variations of serum androgens in euandrogenic women. DESIGN: Prospective evaluation of insulin action in normal nonobese women using hyperglycemic and euglycemic hyperinsulinemic clamp techniques, correlating insulin action to serum testosterone (T), free T, androstenedione (A), and dehydroepiandrosterone sulfate (DHEAS). Statistical analysis used Spearman's rank correlation. SETTING: Yale University Clinical Research Center. PARTICIPANTS: Nonobese females with normal oral glucose tolerance tests, on no medications known to affect glucose metabolism, having the following range of serum androgen levels: T, 0.69 to 3.12 nmol/L; free T, 0.17 to 1.25 nmol/L; A, 2.48 to 11.31 nmol/L; DHEAS, 0.68 to 10.61 mumol/L. Total number of patients studied: hyperglycemic clamps, n = 58; euglycemic hyperinsulinemic clamps, n = 43. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Pancreatic insulin secretion in response to hyperglycemia and insulin action as assessed by insulin-mediated glucose utilization using the euglycemic, hyperinsulinemic clamp technique. RESULTS: We identified no significant correlation between serum androgens and either glucose uptake or insulin-mediated glucose utilization. Glucose-stimulated insulin release was negatively correlated with serum T and free T throughout the normal range of these hormones. CONCLUSION: We conclude that, within the normal range, variations of serum androgens are not correlated with changes in the response to insulin. It seems unlikely, therefore, that modest increases of serum androgens within the normal range are responsible for inducing insulin resistance.

Androgens↗
PubMed1992

Differences in left ventricular structural and functional changes between pheochromocytoma and essential hypertension. Role of elevated circulating catecholamines.

Experimental findings suggest that catecholamines increase protein synthesis and play a role in cardiac hypertrophy. We hypothesize that elevated circulating plasma catecholamines in pheochromocytoma influence cardiac structural and functional remodeling. We compared 15 patients with surgically proven pheochromocytoma and 15 with untreated essential hypertension; we matched the patients for age, sex, body surface area, and blood pressure (BP) levels. Left ventricular hypertrophy (LVH) was identified by M-mode echocardiography in six patients with pheochromocytoma and in four with essential hypertension. Among both groups there were no differences in cardiac structure, no correlation between left ventricular mass and BP, no significant differences in mitral E-F slope, no correlation between either plasma norepinephrine or plasma epinephrine levels, and no differences in the left ventricular structural indices measured. In the pheochromocytoma group, left ventricular end systolic stress and end systolic diameter were significantly lower and left ventricular percent fractional shortening was higher. Plasma norepinephrine levels were higher in the pheochromocytoma group, but did not differ among patients of that group with and without LVH. We conclude that in both pheochromocytoma and essential hypertension, only a subset of patients develop evidence of LVH, and that in pheochromocytoma, the elevation of circulating plasma catecholamines is not necessarily associated with LVH. These results indicate that factors other than catecholamines and BP determine the development of LVH in pheochromocytoma.

Adolescent↗
PubMed1992

Hypoglycemia-induced arginine vasopressin and oxytocin release is mediated by glucoreceptors located inside the blood-brain barrier.

Arginine vasopressin (AVP) and oxytocin (OT) responses during an insulin (0.15 IU/kg body weight) tolerance test (ITT) were evaluated in normal men while they were infused with normal saline, glucose or fructose. Insulin-induced hypoglycemia produced significant plasma AVP and OT increments in the control test. The infusion of fructose was unable to change the posterior pituitary hormonal responses to hypoglycemia. In contrast, AVP and OT responses during ITT were completely abolished when the concomitant infusion of glucose prevented insulin-induced hypoglycemia. These data exclude a direct role of hyperinsulinemia in the mechanism underlying the AVP and OT responses during ITT. Furthermore, since glucose, but not fructose, crosses the blood-brain barrier (BBB), the posterior pituitary hormone responses to hypoglycemia appear to be generated by stimulations of glucosensitive areas located inside the BBB.

Adult↗
PubMed1992

Stimulation of ACTH/cortisol by intravenously infused substance P in normal men: inhibition by sodium valproate.

The effect of synthetic substance P (SP), infused intravenously in doses of 0.5, 1 or 1.5 pmol/kg-1/min-1 over 60 min on ACTH/cortisol secretion was evaluated in 7 healthy men. SP tests and a control test with normal saline were randomly performed at weekly intervals. During tests, SP infusion did not produce untoward side effects or changes in blood pressure. Plasma ACTH and cortisol levels were not modified when normal saline or the lowest dose of SP were infused, whereas they were significantly increased in a dose-dependent fashion when higher amounts of SP were administered. Further studies were performed in another 7 healthy men to test the possible influence of GABAergic neurotransmission on the ACTH/cortisol response to SP. For this purpose, subjects were tested with SP (1.5 pmol/kg-1/min-1) alone and on a different occasion with SP after pretreatment with the GABAergic agent sodium valproate (200 mg 16, 8 and 1 h before the SP test). Again, the administration of SP induced a significant increase in plasma ACTH and cortisol levels. The pretreatment with sodium valproate completely abolished both ACTH and cortisol responses to SP. These data demonstrate for the first time in humans that the systemic infusion of SP stimulates ACTH/cortisol secretion, suggesting the involvement of a GABAergic mechanism in the regulation of the action of SP.

Adrenocorticotropic Hormone↗