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Biomedical subjects

G Rossi

Publications and source records attributed to G Rossi.

At least 469 records · Page 26Linked to original sources
PubMed1993

Interactions of promonocytic U937 cells with proteins of the extracellular matrix.

Monocyte interaction with proteins of the extracellular matrix (ECM) is regulated by expression of specific cell-surface receptors. 12-O-tetradecanoyl phorbol-13-acetate (TPA) has been shown to induce the promonocytic cell line U937 to a more differentiated monocyte-like state. In this study we have analysed the attachment of U937 cells to ECM proteins and the effects of treatment with TPA on this process. Non-induced U937 cells attach to fibronectin- and Matrigel-coated surfaces without TPA stimulation, but TPA further increases adherence to these substrates as measured by an enhanced binding and by the lower concentration of proteins needed in the substrate to achieve 50% of maximal cell adhesion. Attachment to type I collagen was seen only with activated U937 cells, whereas no measurable attachment to bovine serum albumin, vitronectin, and type IV collagen was detected. TPA-activated U937 cells showed a two-fold increase in the expression of the RGD-dependent integrin receptors alpha 3 and alpha 5, and a reduction in the expression of alpha 4, another fibronectin-specific receptor, whereas the common beta 1 chain was unchanged. Attachment of U937 cells to fibronectin was primarily mediated by the alpha 3 and alpha 5 integrins, as revealed by the ability of GRGDS peptides to inhibit attachment, whereas the CS-1 peptide, containing the alpha 4 binding site, was largely ineffective in blocking attachment.

Cell Adhesion↗
PubMed1993

[Splenic embolization and hepatic chemoembolization: combined transcatheter treatment of hepatocellular carcinoma in cirrhosis with hypersplenism].

Liver cirrhosis with hypersplenism is often associated with HCC. In many such cases, chemoembolization (TACE) may be very difficult because of the high incidence of hemorrhagic complications due to treatment and/or following portal hypertension, as well as for poor hematologic tolerance to antiblastic drugs in cirrhotic patients. Six patients with nodular HCC and cirrhosis (Child B) with hypersplenism were treated by combined TACE and partial splenic embolization (PSE) to reduce splenic size and to improve hematologic and hepatic function rates. Actual and long-lasting (up to 6 months since TACE/PSE) positive results were observed in splenic size and in hepatic function synthesis, as well as on hematologic and hemocoagulation factors. The clinical-laboratory improvement following TACE/PSE allowed TACE to be completed in all cases, following the usual protocol based on 3 procedures. Therefore, in the patients with advanced/decompensated cirrhosis and hypersplenism associated with HCC, the combined one-step TACE/PSE treatment can be said to improve patients' tolerance to antiblastic drugs and to reduce the risk of hemorrhagic complications due to invasive radiologic procedures and/or to portal hypertension.

Carcinoma, Hepatocellular↗
PubMed1993

[Bone metastasis of hepatocellular carcinoma: observations in patients treated with transcatheter arterial chemoembolization].

Bone metastases from hepatocellular carcinoma (HCC) are fairly rare, their average occurrence rate being 7.3%. Seven cases of secondary bone lesions (2%) were observed in a series of 347 consecutive cases treated with transcatheter arterial chemoembolization (TACE). The conventional X-ray and the CT patterns of secondary bone involvement were studied, together with histologic features, tumor and cirrhosis stage, and follow-up results. Bone metastases were detected in the early stages of cirrhosis and HCC, which suggested that patients might experience long survival if adequately treated. On the other hand, due to the lower rate of bone metastases in our series than in untreated cases, TACE cannot be said to be of even partial value in the treatment of distant HCC metastases. At any rate, bone metastasis alone is not necessarily a sign of poor prognosis, if it is adequately treated with radio-chemotherapy.

Arteries↗
PubMed1993

Percutaneous embolization of subclavian pseudoaneurysmatic arteriovenous iatrogenic fistula by steel coils.

A case of iatrogenic subclavian arterio-venous fistula with pseudoaneurysm formation is described. Treatment by means of percutaneous embolization, on the venous side, with steel coils has been successful; in order to avoid complications, the arterial side was blocked by an angioplasty balloon. After discussing the more common complications of subclavian vein puncture, the Authors conclude that percutaneous embolization is a valuable alternative to surgery even in such a lesion, especially when the surgical risk is high.

Aneurysm↗
PubMed1993

[Results of the use of the Strecker and Palmaz stents in the iliac artery region. Two years' experience].

Our personal experience is reported with the use of vascular endoprostheses (Strecker and Palmaz stents) in the non-surgical treatment of iliacofemoral steno-occlusive arteriopathy. Over a 15-month period, 56 PTAs were performed in 40 patients; 20 vascular endoprostheses were positioned--17 Strecker and 3 Palmaz stents--in 16 patients, to correct such PTA complications as dissections or to improve the results of a suboptimal PTA maneuver. Venous DSA follow-up was performed at 30 days, and serial color-Doppler US studies were performed every fourth month. Immediate and satisfying clinical results were observed in 15/16 patients (93.7%): only one case of acute thrombosis following the procedure was observed, which could not be treated with intraarterial fibrinolytic therapy and was therefore operated on. Overall long-term patency rate is 100%, mean follow-up is 13.8 months. Finally, the indications for the use of such devices in iliacofemoral arteriopathies are critically discussed, together with the criteria of choice of a type of stent over another one, the immediate and long-term results and the best follow-up protocols.

Arterial Occlusive Diseases↗
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↗