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Biomedical subjects

C Rossi

Publications and source records attributed to C Rossi.

At least 199 records · Page 11Linked to original sources
PubMed1995

[Problems of indications for the treatment of aneurysm of the visceral arteries].

The authors report the clinical history and the treatment of 5 patients with visceral artery aneurysms. The celiac trunk, the common hepatic artery, the inferior pancreaticoduodenal artery and the splenic artery (in 2 different patients) were affected by the aneurysmal disease. Various techniques have been employed in the successful treatment of these patients: radiological embolization of the celiac trunk aneurysms, Dacron graft reconstruction of the common hepatic artery aneurysm, endosaccular ligature and PTFE patching of the inferior pancreatico-duodenal artery aneurysm, endosaccular ligature in one of the two splenic artery aneurysm and simple ligature and splenectomy in the remainder splenic artery aneurysm. Early diagnosis is important in these lesions, because of the trend toward rupture and subsequent high mortality rate. Ultrasonography (US), Computed Tomography (CT) and Magnetic Resonance (MR) are very helpful as diagnostic tools, however angiography represents the method of choice since it could be the first step of the embolization treatment. Furthermore angiography is useful for detection of associated visceral lesions and for the study of collateral blood supply. Treatment choice depends on visceral artery aneurysms localization, the presence of associate lesions and the possible general contraindications. In the latter case, radiological embolization could be the first-choice treatment.

Aged↗
PubMed1995

Atopic dermatitis and allergic diseases with thrombocytosis: a possible link.

BACKGROUND: Thrombocytosis can be present in patients with myeloproliferative disorders or can accompany various conditions, in particular chronic inflammatory diseases, namely chronic bowel diseases, rheumatoid arthritis, and nephritis. OBJECTIVE: We report our experience in 55 patients younger than 45 years of age with increased platelet counts (over 500 X 10(9)/L). Thirty-three were affected by essential thrombocytemia in agreement with polycytemia vera study group criteria and 22 by reactive thrombocytosis. Serotonin concentration has been determine in all the patients. RESULTS: Serotonin was decreased as expected in 23 out of the 33 patients with essential thrombocytemia. In the remaining ten subjects, serotonin was within normal limits as in reactive thrombocytosis. Eight of these subjects had positive histories for allergic rhinitis and two for atopic dermatitis. CONCLUSIONS: Chronic inflammation, present in patients with diseases of the immune system may cause an increased platelet number. One should consider with caution patients with thrombocytosis and positive histories for diseases of the immune system; probably a diagnosis of essential thrombocytemia is not justified.

Adult↗
PubMed1994

Role of 5-HT1A receptors in the antinociceptive action of 8-hydroxy-2-(di-n- propylamino)tetralin in the rat.

The role of 5-HT1A receptors in the antinociceptive action of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) was investigated by using the shock titration test in rats. A subcutaneous injection of 300 micrograms/kg 8-OH-DPAT significantly raised the threshold for flinching, jumping and vocalization whereas 100 micrograms/kg only inhibited the flinch response. l-Propranolol and (+)-[N-tert-butyl-3-4-(2-methoxyphenyl)piperazin-1-yl-2-phenyl propanamide dihydrochloride], (+)-WAY100135, two antagonists at 5-HT1A receptors at 10 mg/kg s.c. antagonized the effect of 300 micrograms/kg 8-OH-DPAT on all measures. The effect of 300 micrograms/kg 8-OH-DPAT on the three measures was unmodified in rats which had received 150 micrograms 5,7-dihydroxytryptamine intracerebroventricularly 10 days before testing. The results suggest that 8-OH-DPAT inhibits nociceptive responses by stimulating postsynaptic 5-HT1A receptors.

5,7-Dihydroxytryptamine↗
PubMed1994

Tacaribe virus gene expression in cytopathic and non-cytopathic infections.

Tacaribe virus (TV) replication was compared in Vero cells infected under conditions leading either to cell death (c.p.e.(+) infection) or to the establishment of persistence (c.p.e.(-) infection). To this end, two virus preparations were employed: one containing a ratio of standard (plaque-forming) viruses to interfering particles (IP) that would induce a distinct lytic response in Vero cells infected at multiplicities giving synchronous infection and another virus stock enriched in IP that would block the cell-killing potential of the cytolytic virus stock. The following results were obtained: (1) No qualitative differences were observed in the species of intracellular viral RNAs in the lytic infection in comparison with infections leading to persistence or during the early stages of persistence. (2) Levels of viral RNAs were severely reduced when the cells were infected with IP in addition to standard viruses, the RNA accumulation being inversely proportional to the ratio of IP to standard viruses used in the infections. (3) Accumulation of the three measurable mRNAs (those corresponding to the glycoprotein precursor [GPC], to the nucleoprotein [N], and to the p11Z protein) ended earlier in the c.p.e.(-) infections (around 18 hr p.i.) than in the c.p.e.(+) infection (45-68 hr p.i.). (4) The rates of synthesis of the GPC, N, and p11Z proteins were largely determined in both the c.p.e.(+) and c.p.e.(-) infections by the amounts of their corresponding mRNAs. (5) The kinetics of accumulation of the S genomes and also the ratios of the S genome to S antigenome were similar in the different infections (accumulation ending at 45-68 hr p.i.). (6) L genome accumulation proceeded for longer time (until 92 hr p.i.) in the c.p.e.(+) infection than in the c.p.e.(-) infections. In the latter accumulation ended at around 45 hr p.i. Until this time ratios of L genome to L antigenome were similar in the different infections. It is concluded that IP affect virus mRNA synthesis early after infection reducing in this way the rate of viral protein synthesis. Low levels of viral proteins might then limit virus replication. In addition, the results support the idea that in TV infections transcription and replication are independently regulated. The implications of these results with regards to the nature and mode of action of TV IP are discussed.

Animals↗
PubMed1994

The nonapeptide leucinostatin A acts as a weak ionophore and as an immunosuppressant on T lymphocytes.

Earlier studies have disclosed that leucinostatin A, a hydrophobic nonapeptide antibiotic, assumes an alpha-helical secondary structure in nonpolar environments. The present report demonstrates that the peptide acts as a weak ionophore facilitating the transport of mono-and divalent cations through the plasma membrane of T lymphocytes and through artificial membranes. Leucinostatin A does not change the thymidine uptake of both resting mouse thymocytes and peripheral blood lymphocytes but dose-dependently prevents the activation of T lymphocytes by tetradecanoyl-phorbol-acetate and by anti-T cell receptor antibody.

Amino Acid Sequence↗
PubMed1994

Serological relationships among viruses in the Hantavirus genus, family Bunyaviridae.

We examined the serological relationships among 32 hantavirus isolates collected from numerous geographic regions and hosts. We prepared rat immune sera to each virus and used these sera in hemagglutination inhibition (HAI) tests, enzyme-linked immunosorbent assays (ELISA), and plaque-reduction neutralization tests to establish the antigenic relationships among the isolates. Our studies included viruses that had been partially characterized previously, as well as isolates for which little or no serological data were available. Our results indicate that, in addition to the four established serological groups of hantaviruses, represented by Hantaan, Seoul, Puumala, and Prospect Hill viruses, there exist at least two other distinct groups of hantaviruses. These groups are represented by Thailand 749 virus, an isolate from Bandicota in Thailand, and by Thottapalayam virus, an isolate from Suncus in India. To compare more closely the antigenic relationships of the isolates to prototype Hantaan virus, we examined the reactivities of Hantaan G1- or G2-specific monoclonal antibodies with the envelope proteins of a number of the isolates. We found that several epitopes defined by monoclonal antibodies to the G2 protein were highly conserved as detected by HAI tests and ELISA. Almost all of the isolates could be neutralized by at least one G2-specific monoclonal antibody. In contrast, epitopes defined by G1 monoclonal antibodies were conserved only among Hantaan-like viruses.

Animals↗
PubMed1994

Evaluation of the reproductive efficiency of simmental and Friesian dairy cows farmed in Friuli (Northeast Italy) by the analysis of progesterone levels.

The present research was conducted 1) to investigate the usefulness of progesterone profiles for the study of reproductive efficiency, 2) to identify new reproductive indexes and 3) to examine the possibility of modelling changes in the biological status of animals. Two groups of dairy cows were chosen for this investigation: Italian Simmental and Italian Friesian cows. Milk samples were taken from each cow every 3 to 4 d between Day 10 and Day 240 after calving, and whey progesterone was determined by RIA. The cows were classified into the following 4 categories on the basis of their luteinic activity: 1) Acyclic cows with P4 values <100 pg/ml; 2) Cyclic cows with a normal cycle (1 or 2 samples <100 pg/ml, followed by 1 sample >/=120 pg/ml, followed by at least 3 samples >/=200 pg/ml, followed by 1 sample <100 pg/ml) or a short cycle (1 or 2 samples <100 pg/ml, followed by 1 sample >/=120 pg/ml, followed by 2 samples >/= 200 pg/ml, followed by 1 sample <100 pg/ml followed by a normal cycle); 3) pregnant cows with P4 values >120 pg/ml at 21 to 24 d from AI; and 4) cows with atypical luteinic activity and P4 values >120 pg/ml in a single sample. Analysis of the P4 frequency distribution indicated that ovarian activity resumed from Day 15 and Day 18 after calving in the Italian Friesian and Italian Simmental cows, respectively, and the highest percentage of cyclic cows was observed on Day 60 for Italian Friesian cows (45%) and Day 70 for Italian Simmental cows (55%). The acyclic phase was considered to be concluded by Day 164 and Day 120 for Italian Friesian and Italian Simmental cows, respectively. By Day 240, 66% of Italian Friesian cows and 79% of Italian Simmental cows were pregnant. The percentage of cows with atypical luteinic activity was almost constant throughout the experiment (Italian Friesian=5 to 10%, Italian Simmental=10 to 15%). The calving-conception interval was 104 d for Italian Friesian cows and 94 d for Italian Simmental cows. In both groups, the area on the P4 frequency diagram representing the acyclic cows was not very different from that representing the cyclic cows, while the area occupied on the diagram by pregnant animals was larger. These results are derived from an accurate mathematical analysis. The average number of times in the acyclic status for both groups of cows was about 3-fold smaller than the average number in the cyclic status.

Journal Article↗
PubMed1994

Essential thrombocythemia and pregnancy: a report of six normal pregnancies in five untreated patients.

OBJECTIVE: To report our experience with essential thrombocythemia complicating pregnancy. METHODS: Over a 5-year period, we studied 21 women of reproductive age affected by essential thrombocythemia. Diagnoses were based on previously published Polycythemia Vera Study Group criteria. RESULTS: Five of our 21 patients became pregnant (total six pregnancies). All pregnancies were carried to term, with uncomplicated deliveries of normally formed infants. No thrombotic or hemorrhagic complications were encountered. CONCLUSION: Normal pregnancy and delivery is readily possible in patients with essential thrombocythemia.

Adult↗
PubMed1994

Electromotive administration of a new morphine formulation: morphine citrate.

Two formulations of morphine citrate were synthesized: trimorphine citrate, 3(MH)+(C6H5O7)3- and morphine sodium citrate, 3(MH)+3Na+2(C6H5O7)3-. Four healthy individuals volunteered to undergo electromotive administration of the two formulations. Application of electric current (2 mA) to solutions of trimorphine citrate for 1 h resulted in iontophoretic transcutaneous administration of therapeutic quantities of morphine, without deleterious reduction in the pH of the drug solutions. Application of a 2-mA current to solutions of morphine sodium citrate for 2 h resulted in combined iontophoretic and electrophoretic delivery of morphine with increased administration rates and an improved buffering capacity of the drug solutions.

Administration, Cutaneous↗
PubMed1994

Enzyme-linked immunosorbent assay using a recombinant baculovirus-expressed Bacillus anthracis protective antigen (PA): measurement of human anti-PA antibodies.

We developed an antigen capture enzyme-linked immunosorbent assay (ELISA) which does not require purified protective antigen (PA) for detection of human antibodies to Bacillus anthracis PA. Lysates of Spodoptera frugiperda (Sf-9) cells infected with recombinant baculovirus containing the PA gene were used as the source of PA to develop the ELISA. Recombinant PA from crude Sf-9 cell lysates or PA purified from B. anthracis Sterne strain was captured by an anti-PA monoclonal antibody coated onto microtiter plates. We demonstrated that human serum antibody titers to PA were identical in the ELISA whether we used crude Sf-9 cell lysates containing recombinant baculovirus-expressed PA or purified Sterne PA. Finally, false-positive results observed in a direct ELISA were eliminated with this antigen capture ELISA. Thus, the antigen capture ELISA with crude preparations of baculovirus-expressed PA is reliable, safe, and inexpensive for determining anti-PA antibody levels in human sera.

Animals↗
PubMed1994

Detection and identification of Leptospira interrogans serovars by PCR coupled with restriction endonuclease analysis of amplified DNA.

Primers for PCR were selected from a sequenced fragment of clone pL590, which contains a repetitive element present in the genome of Leptospira interrogans serovar hardjo type hardjoprajitno (M. L. Pacciarini, M. L. Savio, S. Tagliabue, and C. Rossi, J. Clin. Microbiol. 30:1243-1249, 1992). A specific DNA fragment was amplified from the genomic DNAs of serovar hardjo type hardjoprajitno and nine serovars also belonging to L. interrogans as a consequence of the spread of the same or a closely related repetitive element within this species (Pacciarini et al., J. Clin. Microbiol. 30:1243-1249, 1992). In addition, specific amplification was obtained from two Leptospira borgpetersenii serovars (tarassovi and hardjo type hardjobovis). Negative PCR results were observed with all of the other Leptospira serovars tested, including nonpathogenic ones (serovars patoc and andamana), another spirochete (Borrelia burgdorferi), bacteria commonly found in biological samples, and swine and bovine cell lines. Direct PCR on biological samples such as kidney samples demonstrated that preliminary isolation and culture of Leptospira cells are not required for efficient detection. Furthermore, digestion of the amplified DNA with the enzymes HinfI and DdeI yielded specific polymorphic patterns, allowing discrimination among the majority of the serovars. These methods were applied to 25 field isolates of serovar pomona, leading to the conclusion that they were suitable for the simple and rapid detection of L. interrogans and for serovar identification.

Animals↗
PubMed1994

Identification and characterization of a 3C-like protease from rabbit hemorrhagic disease virus, a calicivirus.

Expression studies conducted in vitro and in Escherichia coli led to the identification of a protease from rabbit hemorrhagic disease virus (RHDV). The gene coding for this protease was found to be located in the central part of the genome preceding the putative RNA polymerase gene. It was demonstrated that the protease specifically cuts RHDV polyprotein substrates both in cis and in trans. Site-directed mutagenesis experiments revealed that the RHDV protease closely resembles the 3C proteases of picornaviruses with respect to the amino acids directly involved in the catalytic activity as well as to the role played by histidine as part of the substrate binding pocket.

Amino Acid Sequence↗
PubMed1994

A newborn with ring chromosome 10, aganglionic megacolon, and renal hypoplasia.

A newborn infant is reported who had aganglionic megacolon, renal hypoplasia, severe growth retardation, generalised hypotonia, and various dysmorphic features. Chromosome analysis of lymphocytes and fibroblasts showed a ring chromosome 10 with breakpoints at p13-15 and q26. AluI digestion showed that the ring chromosome was monocentric. FISH with an alpha satellite probe specific for chromosome 10 showed one signal only in about 20% of interphase nuclei. It is suggested that aganglionic megacolon could result from dynamic somatic mosaicism owing to loss of the ring chromosome.

Chromosome Mapping↗
PubMed1994

End-stage cardiac failure in humans is coupled with the induction of proliferating cell nuclear antigen and nuclear mitotic division in ventricular myocytes.

Proliferating cell nuclear antigen (PCNA) is a late growth-regulated gene that is expressed at the G1-S boundary of the cell cycle and is required for DNA synthesis and cell proliferation. Since quantitative results suggest that myocyte hyperplasia occurs in the decompensated human heart, we postulated that induction of the PCNA gene may be present in the failing heart in humans. PCNA protein was detected in myocardial samples obtained from the left and right ventricles of patients with congestive heart failure. Endomyocardial biopsies collected from donor subjects were used as control tissue. The percentage of positively stained myocyte nuclei in the ventricles was established by using PCNA monoclonal antibody and the immunoperoxidase technique. The localization of PCNA in myocytes was confirmed by alpha-sarcomeric actin antibody staining. PCNA labeling was present in left ventricular myocytes of 29 of the 32 hearts examined. In the right ventricle, 24 of the 29 samples showed positive staining. In a subset of 25 patients, the percentage of PCNA-labeled myocyte nuclei was measured and found to constitute 49 +/- 22% of left ventricular myocytes. A similar analysis for the right ventricle, conducted in 21 patients, showed that 49 +/- 19% of the myocyte nuclei exhibited PCNA protein. In addition, mitotic figures in myocytes were documented. A quantitative analysis of this cellular process revealed that 11 myocyte nuclei per 1 million cells exhibited mitotic images in chronic heart failure. Immediately after myocardial infarction, two cells per million showed mitotic division, and this phenomenon was restricted to the region adjacent to the necrotic tissue. No PCNA labeling or nuclear mitotic images were detected in the ventricular myocardium of control subjects. Thus, the observation that diffuse PCNA labeling and myocyte mitotic division are present in hearts with end-stage failure strongly suggests that adult ventricular myocytes are not terminally differentiated cells and that myocyte cellular hyperplasia may constitute a growth reserve mechanism of the diseased heart.

Adult↗
PubMed1993

Mouse antithrombotic assay. Inhibition of platelet thromboembolism by disintegrins.

The mouse antithrombotic assay represents a model of fatal pulmonary thromboembolism induced by intravenous injection of collagen and epinephrine. Mice were protected by low doses of two disintegrins, albolabrin (10 micrograms/mouse) and eristostatin (0.6 micrograms/mouse), whereas high doses of a thrombin inhibitor and an inhibitor of von Willebrand Factor binding to glycoprotein Ib were not effective. Injection of collagen and epinephrine resulted in the drop of platelet count and accumulation of platelet aggregates in the lung that appears to be the immediate cause of death. Albolabrin or eristostatin administration did not prevent the decrease of platelet count. Injection of albolabrin resulted in the formation of smaller and reversible platelet aggregates in the lungs and decreased accumulation of 51Cr-labeled platelets in the lung suggesting that this disintegrin decreases formation of platelet aggregates in vivo. We compared the effects of albolabrin and erisostatin on platelet aggregation, tail bleeding time, and survival of challenged animals. Eristostatin was about 5 times more potent in inhibiting platelet aggregation in vitro than albolabrin and 38 times more potent than albolabrin in protecting animals from sudden death. Both disintegrins, at the same doses (0.6-5 micrograms/mouse), caused similar dose-dependent prolongation of the bleeding time; however, only eristostatin exerted a protective effect. In conclusion, a) the mouse antithrombotic assay is a suitable model to screen and to evaluate the potency of platelet fibrinogen receptor antagonists in vivo; b) the results of the antithrombotic assay correlate better with the inhibition of platelet aggregation in vitro than with the prolongation of bleeding time.

Amino Acid Chloromethyl Ketones↗
PubMed1993

Clonidine-induced place preference is mediated by alpha 2-adrenoceptors outside the locus coeruleus.

Clonidine, administered intraperitoneally at doses of 0.05 and 0.5 mg/kg, produced a conditioned place preference when paired with the less preferred compartment. No preference for either compartment was found when a balanced conditioning place preference paradigm was used. Infusion of 6 micrograms/microliters 6-hydroxydopamine in the locus coeruleus, which markedly depleted noradrenaline in terminal regions, did not modify the effect of 0.05 and 0.5 mg clonidine on place preference. The effect of 0.5 mg/kg was prevented by 1 mg/kg idazoxan, an alpha 2-adrenoceptor antagonist, but not by 3 mg/kg prazosin, which blocks alpha 1-adrenoceptors. Idazoxan by itself (at doses from 0.3 to 3 mg/kg) induced a conditioned place preference when paired with the less preferred side. The results suggest that clonidine has motivational properties which serve to attenuate the aversiveness of the less preferred side in a conditioned place preference paradigm. Stimulation of alpha 2-adrenoceptors postsynaptic to noradrenaline-containing neurons seems to be involved.

Adrenergic alpha-Antagonists↗
PubMed1993

Environmental aspects of pesticide use in Italian agriculture.

Pesticides used in agriculture accumulate in organisms and reach man through complex metabolic pathways. Accurate analysis of pesticides presence in each step of the food chain is necessary because of the high number of these substances, their potential toxicity and the presence of amplified toxic effects due to synergic interactions. In the same way it is necessary to evaluate the environmental effects of the whole pesticides cycle, from industrial production until final disposal of used containers and residuals. Furthermore recent introduction of new categories of chemicals which are not strictly classifiable as pesticides (photosynthetic activity stimulators, aesthetic aspect enhancers) and not yet sufficiently studied in their metabolic behaviour, increase the problem complexity. Complete studies about these complex problems and about the effects on ecosystems have not yet been carried out in Italy, due to ambiguous laws and regulations, inadequate data collection methods and decisional influence of the chemical industry on agriculture policy.

Agriculture↗