Biomedical subjects

C Rossi

Publications and source records attributed to C Rossi.

At least 235 records · Page 13Linked to original sources

PubMed1992

Incidence of thrombocytosis in lymphomas.

Reactive thrombocytosis due to malignancies and in particular those related to lymphomas have not yet been extensively evaluated. We report data on thrombocytosis recognized in 18 out of 101 patients with lymphomas diagnosed in our department over the last 3 years. All showed high platelet counts at the time of diagnosis. The incidence of thrombocytosis seems to be more frequent in males (21.2%) than in females (14.8%) and a slightly higher frequency was found in Hodgkin's disease (21.4%) than in non Hodgkin's lymphomas (16.4%). The incidence of thrombocytosis in lymphomas seems to be similar to that seen in other malignancies and because of this we conclude that a high platelet count cannot be used to distinguish malignancies.

Bone Marrow↗

PubMed1991

Interleukin-1 and tumour necrosis factor induce hepatic haem oxygenase. Feedback regulation by glucocorticoids.

During the acute-phase response to bacterial endotoxins [lipopolysaccharide (LPS)] in mice, the hepatic activity of haem oxygenase (HO) is increased. We investigated the effects of the potential humoral mediators of inflammation, interleukin-1 (IL-1) and tumour necrosis factor (TNF), on hepatic HO activity. In mice, IL-1 or TNF (5 micrograms) caused an elevation of HO activity comparable with that after LPS exposure (20 micrograms). The induction of HO by both cytokines was more pronounced in adrenalectomized mice. In the intact mice induction of HO activity by cytokines was observed earlier than depression of 7-ethoxycoumarin O-de-ethylase, a cytochrome P-450-dependent enzyme activity. Pretreatment with dexamethasone of the intact mice (3 mg/kg) or of the adrenalectomized mice (0.4 mg/kg) prevented the induction of HO activity caused by LPS and IL-1 respectively. These results suggest that: (1) HO activity is increased during an IL-1- or TNF-mediated acute-phase response, so haem metabolism might be a potential target of inflammation, and (2) HO induction by IL-1 and TNF does not require glucocorticoids, which in fact act as antagonists of this cytokine-induced effect.

7-Alkoxycoumarin O-Dealkylase↗

PubMed1991

A clinicopathologic study of lymphoid neoplasias associated with human immunodeficiency virus infection in Italy.

The clinicopathologic features of 45 human immunodeficiency virus (HIV)-infected patients (mainly intravenous drug users [IVDU]) with lymphoid neoplasias seen from September 1984 through July 1990 at an Italian cancer center are reviewed. Thirty-five had systemic non-Hodgkin's lymphoma (NHL), and ten had Hodgkin's disease (HD). Histologically, 27 NHL cases were intermediate grade (five cases) or high grade (22 cases, 14 of the small noncleaved cell type), according to the Working Formulation. Eight NHL cases, including four anaplastic large cell (ALC) BerH2 (CD30)-positive lymphomas, were in the miscellaneous group. Immunohistologic and/or gene rearrangement analysis showed the B-cell origin of 20 of the 24 NHL cases studied. At presentation, 71% of NHL patients had advanced stages (Stage III or IV), and 85% had extranodal disease (predominantly gastrointestinal tract and marrow). Of the 23 patients evaluable for treatment, only seven had a complete clinical response after lymphoma therapy; the median survival of 34 evaluable patients was 22 months after the diagnosis of NHL. Fifteen patients died; most deaths were attributable to progressive lymphoma and opportunistic infections. As with NHL, advanced disease, extranodal involvement, aggressive histologic findings, and poor response to therapy were also observed in patients with HD. This study shows that lymphoid neoplasias occurring in Italian IVDU with HIV infection and those previously reported in North American homosexual men with HIV infection share similar clinicopathologic features. However, some features such as the absence of history of Kaposi's sarcoma at diagnosis, the lack of detection of primary brain and rectal NHL, and the occurrence of B-cell ALC BerH2 (CD30)-positive NHL were observed uniquely in this series of patients.

Adult↗

PubMed1991

Role of central serotonergic neurons in the effect of sertraline in rats in the forced swimming test.

Sertraline, administered i.p. in single doses or as three injections in 24 h, significantly reduced the immobility of rats in the forced swimming test at 64 and 100 mumol/kg. The effect of three doses of 64 mumol/kg in 24 h was not modified in animals treated i.p. with metergoline (5 mg/kg) 3 h before testing. I.c.v. administration of 150 micrograms 5,7-dihydroxytryptamine, which depleted brain serotonin, or infusion of 6 micrograms 6-hydroxydopamine in the locus coeruleus, which markedly depleted noradrenaline in terminal regions, was also ineffective. The effect of 64 mumol/kg sertraline, once daily for 7 days, was not modified by i.c.v. 5,7-dihydroxytryptamine. The effect of three doses of 64 mumol/kg sertraline in 24 h was instead completely antagonized by 100 mg/kg sulpiride given 90 min before testing. The exact mechanism of this effect and its relevance for the favourable effects of sertraline in human depression remain to be clarified.

1-Naphthylamine↗

PubMed1991

Inhibition of murine melanoma cell-matrix adhesion and experimental metastasis by albolabrin, an RGD-containing peptide isolated from the venom of Trimeresurus albolabris.

Albolabrin, a 7.5-kDa cysteine-rich protein isolated from the venom of Trimeresurus albolabris, contains the arginine-glycine-aspartic acid (RGD) cell recognition sequence found in many cell adhesion-promoting extracellular matrix proteins, such as fibronectin and laminin. Albolabrin belongs to a family of RGD-containing peptides, termed disintegrins, recently isolated from the venom of various vipers and discovered to be potent inhibitors of both platelet aggregation and cell-substratum adhesion. Here we report that albolabrin inhibited the attachment of B16-F10 mouse melanoma cells to either fibronectin or laminin absorbed on plastic. When immobilized on plastic, albolabrin promoted B16-F10 melanoma cell attachment; this was inhibited by either RGD-serine (RGDS) or antibodies to integrins, suggesting that albolabrin binds via its RGD amino sequence to integrin receptors expressed on the melanoma cell surface. In an in vivo experimental metastasis system, albolabrin at a concentration of 300-600 nM inhibited C57BL/6 mouse lung colonization by tail vein-injected mouse melanoma cells and was at least 2000 times more active than RGDS in this assay. We propose that albolabrin inhibits tumor cell metastasis by inhibiting integrin-mediated attachment of melanoma cells to RGD-containing components of the extracellular matrix in the mouse lung.

Animals↗

PubMed1991

A stochastic mover/stayer model for an HIV epidemic.

A multicompartmental model is proposed to deal with the spread of the HIV epidemic. Stratification with respect to high- and low-risk groups is taken into account, introducing a "fuzzy" decomposition of the compartment of susceptibles. The infectivity period is staged using different levels of CD4 cell counts. Asymptotic behavior is studied, and some simulation results are reported in tabular and graphic forms.

Computer Simulation↗

PubMed1991

Pleiotropic-resistant phenotype is a multifactorial phenomenon in human colon carcinoma cell lines.

The biochemical basis of multidrug-resistant (MDR) phenotype has been investigated in drug-resistant sublines independently obtained in our laboratories by single step doxorubicin (DOX) selection of LoVo, DLD1, and SW948 human colon carcinoma (HCC) cell lines. All the chemoresistant sublines have been found to be cross-resistant to DOX, actinomycin-D (ACT-D) and vincristine (VCR) but not to cis-diamminedichloroplatinum (CDDP), and have exhibited an increased expression level of mdr1 mRNA and gp170 glycoprotein. Comparative analyses in drug-resistant and sensitive cells of resistance index, extracellular and intracellular equitoxic DOX concentrations, and mdr1 gene products expression have indicated that MDR phenotype is a multifactorial phenomenon due to different and possibly independent biochemical mechanisms which cooperate, in varying degrees from cell line to cell line, in conferring cellular chemoresistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1991

Concentrations of VP16 and VM26 in human brain tumors.

VP16 and VM26 were determined by high pressure liquid chromatography in intracerebral tumors, adjacent normal brain tissue, plasma and CSF samples from 24 patients given the two drugs before surgical resection of the tumor. The drugs were administered at doses of 100-150 mg/m2 as a 1-hour i.v. infusion, between 1.5 and 12 hours before surgery. Concentrations of VP16 ranged between 1.05 and 3.28 micrograms/g in tumors in the series of patients who received the drug 1.5-3 hours before surgery and between less than 0.05 and 1.12 micrograms/g in four patients who received the drug 9-13 hours before surgery. Tumor concentrations of VM26 also varied, ranging from less than 0.05 to 1.68 micrograms/g between 1.5 and 12 hours before surgery. VP16 and VM26 in the apparently normal brain tissue surrounding the tumor were low or undetectable except in one patient who had received radiotherapy, in whom we found 3.1 micrograms/g.

Adult↗

PubMed1991

Intra-arterial urokinase infusion in diabetic patients with rapidly progressive ischemic foot lesions.

OBJECTIVE: The effectiveness of local intra-arterial thrombolysis by urokinase was evaluated in eight non-insulin-dependent diabetic patients with angiographic evidence of infrapopliteal occlusive disease and rapidly progressive foot lesions. RESEARCH DESIGN AND METHODS: With an electric peristaltic pump, urokinase was infused for 96 h by a 5-6 F catheter introduced into the femoral artery and placed immediately above the occluded infrapopliteal arteries. After baseline, angiography was repeated at 24- to 48-h intervals and at conclusion of the treatment. RESULTS: Six patients showed immediate improvement of clinical symptoms. Angiography revealed the reestablishment of blood flow in collateral vessels of the leg and foot in the dorsal pedal artery in three patients and in the plantar arch in two. Recanalization of the major arteries of the trifurcation was not achieved. After 12 mo of follow-up, all limbs were salvaged, although four patients required vascular reconstruction to further improve foot perfusion and complete healing. CONCLUSIONS: Intra-arterial urokinase, which opens collateral and smaller vessels of the leg and foot in patients with diabetes, may be effective in improving blood flow in lower extremities and in making the patient a better candidate for vascular surgery.

Aged↗

PubMed1991

Thrombosis and hemorrhage in thrombocytosis: evaluation of a large cohort of patients (357 cases).

We report clinical and laboratory findings in a large cohort of patients with thrombocytosis (357 cases). At the time of study, the patients showed a platelet number greater than 500 x 10(9)/L. The follow-up of patients ranged between 3 and 16 years. 123 patients were affected by polycythemia vera (PV), 97 by essential thrombocythemia (ET), 13 by chronic myeloid leukemia (CML) and 31 by myelofibrosis (MF). In 93 subjects, the thrombocytosis was reactive (ST). We found the highest incidence of thrombosis in PV patients, especially concerning the cerebro-vascular system; thrombosis, but in a lower percentage, was recognized in MF patients. Also, ET patients showed a number of thrombosis in peripheral arteries. Thrombosis of the coronary arteries were quite rare while 25% of MPD subjects showed peripheral vein thrombosis. We take into account that many patients showed thrombocytosis associated to one or more atherosclerotic risk factors. Hemorrhages were present especially in CML and in ET, but were not as frequent as thrombosis. The most common bleeding manifestations affected skin and mucosa. Hemorrhages after surgical procedures were also frequent. Gastro-intestinal bleeding was not strictly related to anti-aggregating therapy and occurred not only in PV but also in ET patients.

Adult↗

PubMed1991

[The usefulness of angiographic studies in the vascular complications of liver transplantation. The authors' own experience].

The authors report their experience with angiographic techniques in the diagnosis of vascular complications after liver transplantation. From 1986 to 1990, 78 patients were transplanted in our Hospital; of them, 8 underwent angiographic investigations for vascular complications. Angiography is very important when vascular complications are suspected, in the patients with a rise in cytolytic enzymes and in bilirubine levels, with hyperpyrexia, and with bioptic confirmation of no rejection. Duplex US is useful in the evaluation of portal canalization; if there are any doubts, angiography is performed also in the preoperative phase.

Adult↗

PubMed1991

Surgical management of corneal perforation with expanded polytetrafluoroethylene (Gore-Tex).

We report a series of six patients with spontaneous corneal perforations successfully treated with a temporary graft of expanded polytetrafluoroethylene (Gore-Tex) until a definitive penetrating keratoplasty could be performed. Two other patients had a paralimbic perforation treated with an artificial lamellar Gore-Tex graft. No infection or extrusion developed, and the artificial graft kept the anterior chamber tight in all cases. Gore-Tex appears to be a safe and effective material for use in treating acute central and peripheral corneal perforation.

Adult↗

PubMed1990

Effect of angiotensin II on the antitumor activity and cardiotoxicity of doxorubicin.

The effects of angiotensin II (AII) on the antitumor activity and cardiotoxicity of doxorubicin (DXR) were tested in rats bearing Walker 256/A carcinoma. The animals received 2, 4 or 6 mg/kg of DXR as a bolus i.v. injection, with or without a concurrent i.v. infusion of 2 micrograms/kg/min of AII, starting 1 h prior to DXR administration for a total of 6 h. Neither the antitumor activity, nor the myocardial toxicity of DXR, as assessed by ECG evaluation (Q alpha T duration), were affected by AII at the tested dose. 100% of the animals receiving 6 mg/kg of DXR with or without AII were cured from the tumor, but subsequently some of them developed toxic signs and eventually died within the 12th week after treatment. Rats receiving DXR + AII showed a higher long-term survival than those receiving DXR alone; therefore, a possible interference with other DXR-induced side effects, such as nephrotoxicity, is hypothesized.

Angiotensin II↗

PubMed1990

Epidemiological and linkage studies on Huntington's disease in Italy.

The results of an epidemiological survey on Huntington's disease in the Lazio Region, Central Italy, and of linkage studies in a subset of families are reported. From a total of 99 ascertained families and 491 patients, a prevalence of 25.6 X 10(-6) was obtained, with distributions of age at onset and age at death similar to those described in the literature. No relationship with the sex of the transmitting parent was observed. Analysis of 10 chromosome 4 restriction fragment length polymorphisms in 11 families showed consistent linkage between the genetic loci D4S10, D4S43 and D4S95, and the disease. A recombination rate of 0.08 for D4S10 markers was obtained in this sample. Allelic frequencies of DNA markers in the general population are also reported.

Adolescent↗

PubMed1990

Percutaneous transcatheter arterial embolization of bone and soft tissue tumors.

Arterial embolization was performed in 36 patients with tumors of bone and soft tissue. Embolization was the only treatment in seven patients with benign lesions. Fourteen patients underwent embolization before surgery to obtain hemostasis and/or reduce tumor size. Fifteen patients with inoperable primary bone tumors or skeletal metastases underwent palliative embolization. The best results were obtained in aneurysmal bone cysts.

Bone Cysts↗

PubMed1990

A stochastic model of the genetic predisposition to ageing: an application to twin data.

In previous papers a stochastic model of the ageing process has been proposed. Some genetic parameters (redundance, repair) have been used to explain the observed differential predisposition to the process and family heredity. Because the process is basically due to effective random mutations, any individual of the population would be predisposed differently to ageing according to the structure of his/her genome. In the present paper, the previous model is generalized to take into account an additional genetic parameter, namely, the stability against random mutations, defined as the probability that a random mutation in a codon would produce no mutation in the corresponding protein. Estimation problems connected with the model are approached on the basis of twin data in maximum likelihood estimation as well as in bayesian framework. Some comparisons between the two methods are reported.

Aging↗

PubMed1990

Interaction of purine nucleotides with inert paramagnetic Cr(III) probes evaluated by NMR relaxation effects. Molecular mechanics calculations on Cr(III) and Co(III) polyphosphate complexes.

The 1H NMR relaxation effects produced by paramagnetic Cr(III) complexes on nucleoside 5'-mono- and -triphosphates in D2O solution at pH' = 3 were measured. The paramagnetic probes were [Cr(III)(H2O)6]3+, [Cr(III)(H2O)3(HATP)], [Cr(III)(H2O)3(HCTP)] and [Cr(III)(H2O)3(UTP)-, while the matrix nucleotides (0.1 M) were H2AMP, HIMP-, and H2ATP2-. For the aromatic base protons, the ratios of the transverse to longitudinal paramagnetic relaxation rates (R2p/R1p) for the [Cr(III)(H2O)6]3+/H2ATP2-, [Cr(III)(H2O)3(HATP)]/H2ATP2-, [Cr(III)(H2O)3(HCTP)]/H2ATP2 and [Cr(III)(H2O)3(UTP)]-/H2ATP2 systems were below 2.33 so the dipolar term predominates. For a given nucleotide, R1p for the purine H(8) signal was larger than for the H(2) signal with the [Cr(III)(H2O)6]3+ probe, while R1p for the H(2) signal was larger with all the other Cr(III) probes. Molecular mechanics computations on the [Cr(III)(H2O)4(HPP)(alpha,beta)], [Cr(III)(NH3)4(HPP)(alpha,beta)], [Co(III)(NH3)3(H2PPP)(alpha,beta,gamma)] and [Co(III)(NH3)4(HPP)(alpha,beta)] complexes gave calculated energy-minimized geometries in good agreement with those reported in crystal structures. The molecular mechanics force constants found were then used to calculate the geometry of the inner sphere [Cr(III)(H2O)6]3+ and [Cr(III)(H2O)3(HATP)(alpha,beta,gamma)] complexes as well as the structures of the outer sphere [Cr(III)(H2O)6]3(+)-(H2AMP) and [Cr(III)(H2O)6]-(HIMP)- species. The gas-phase structure of the [Cr(III)(H2O)3(HATP)(alpha,beta,gamma)] complex shows the existence of a hydrogen bond interaction between a water ligand and the adenine N(7)(O...N = 2.82 A). The structure is also stabilized by intramolecular hydrogen bonds involving the -O(2')H group and the adenine N(3) (O...N = 2.80 A) as well as phosphate oxygen atoms and a water molecule (O...O = 2.47 A). The metal center has an almost regular octahedral coordination geometry. The structures of the two outer-sphere species reveal that the phosphate group interacts strongly with the hexa-aquochromium probe. In both complexes, the nucleotides have a similar "anti" conformation around the N(9)-C(1') glycosidic bond. However, a very important difference characterizes the two structures. For the (HIMP)- complex, strong hydrogen bond interactions exist between one and two water ligands and the inosine N(7) and O(6) atoms, respectively (O...O = 2.63 A; O...N = 2.72, 2.70 A). For the H2AMP complex, the [Cr(III)(H2O)6]3+ cation does not interact with N(7) since it is far from the purine system. Hydrogen bonds occur between water ligands and phosphate oxygens. The Cr-H(8) and Cr-H(2) distances revealed by the energy-minimized geometries for the two outer sphere species were used to calculate the R1p values for the H(8) and H(2) signals for comparison with the observed R1p values: 0.92(c), 1.04(ob) (H(8)) and 0.06(c), 0.35(ob) (H(2)) for H2AMP; and 3.76(c), 4.53(ob) (H(8)) and 0.16(c), 0.77(ob) s-1 (H(2)) for HIMP-.(ABSTRACT TRUNCATED AT 400 WORDS)

Chromium↗

PubMed1990

On the estimation of the age at onset distribution in Huntington's chorea using the EM algorithm.

Huntington's chorea is a late onset disease of the nervous system whose mode of inheritance conforms to the autosomal dominant model. The present paper shows how the problem of estimating the distribution of age at onset of the disease can be dealt with as an incomplete data problem via the EM algorithm, both in the parametric and non-parametric setting. In this way it is possible to take into account not only the heterozygotes in the population under study who are manifestly affected, but also those who are apparently unaffected. The estimation of the distribution of age at onset of the disease is required for estimating the posterior probability of heterozygosity of the individual at risk using Bayes' theorem. The proposed approach was applied to data derived from a survey carried out on the population of Latium, Italy.

Adolescent↗