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R Rossi

Publications and source records attributed to R Rossi.

At least 163 records · Page 9Linked to original sources
PubMed1999

[Multidisciplinary management of malignant hepatic tumors in children: a recent national experience].

BACKGROUND: Malignant hepatic tumors (Mht) are rare in children. Among them hepatoblastoma (HB) is the most common. AIM: To report the results of the multidisciplinary management in 6 consecutive children: five HB and one metastatic Wilms tumor (MWT). PATIENTS AND METHODS: The mean age of patients was 42 months. All HB patients had elevated serum alfafetoprotein (median 150,000 ng/ml). All patients received preoperative chemotherapy: HB patients received carboplatin/doxorubicin alternating with cisplatin, and the MWT patient, vincristine alone. Surgery included two formal right and two formal left hepatectomies, one extensive central resection with partial left segmentectomy, and one lateral segmentectomy. Extracorporeal circulation was used in the child with atrial involvement. All patients received postoperative chemotherapy. RESULTS: All tumors had variable regresion on preoperative chemotherapy. Complete resection with negative margins was achieved in all patients. The degree of tumor necrosis on histology ranged from 60% to 90%. Alfafetoprotein levels fell to under 10 ng/ml in all HB cases, one to three months after surgery. All patients survive free of disease at a median follow up of 19 months. CONCLUSION: A multidisciplinary approach including the well timed used of chemotherapy and surgery is highly effective in the management of pediatric malignant tumors.

Child↗
PubMed1998

Fast-reacting thiols in rat hemoglobins can intercept damaging species in erythrocytes more efficiently than glutathione.

The S-conjugation rates of the free-reacting thiols present on each component of rat hemoglobin with 5,5-dithio-bis(2,2-nitrobenzoic acid) (DTNB) have been studied under a variety of conditions. On the basis of their reactivity with DTNB (0.5 mM), three classes of thiols have been defined as follows: fast reacting (fHbSH), with t1/2 <100 ms; slow reacting (sHbSH), with t1/2 30-50 s; and very slow reacting (vsHbSH), with t1/2 180-270 s. Under paraphysiological conditions, fHbSH (identified with Cys-125beta(H3)) conjugates with DTNB 100 times faster than glutathione and approximately 4000 times more rapidly than (v)sHbSH (Cys-13alpha(A11) and Cys-93beta(F9)). Such characteristics of fHbSH reactivity that are independent of the quaternary state of hemoglobin are mainly due to the following: (i) its low pK (approximately 6.9, the cysteinyl anion being stabilized by a hydrogen bond with Ser-123beta(H1)) and (ii) the large exposure to the solvent (as measured by analysis of a model of the molecular surface) and make these thiols the kinetically preferred groups in rat erythrocytes for S-conjugation. In addition, because of the high cellular concentration (8 mM, i.e. four times that of glutathione), fHbSHs are expected to intercept damaging species in erythrocytes more efficiently than glutathione, thus adding a new physiopathological role (direct involvement in cellular strategies of antioxidant defense) to cysteinyl residues in proteins.

Animals↗
PubMed1998

Role of protein -SH groups in redox homeostasis--the erythrocyte as a model system.

The reactivities of the sulfhydryl groups of rat, turkey, human, and calf hemoglobin were studied together with the enzyme activities of glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, and glutaredoxin in lysed erythrocytes to evaluate their roles in regulating redox homeostasis. The results of -SH reactivity showed rate constants spanning four orders of magnitude (k2, calf, 6.67 M-1 s-1; rat -SH fast reacting, 2.8 x 10(4) M-1 s-1). Enzyme activities of glucose-6-phosphate dehydrogenase ranged from 0.402 U/ml (calf) to 0.900 U/ml (rat), glutathione reductase from 0. 162 U/ml (rat) to 0.381 U/ml (human), glutaredoxin from 0.778 U/ml (rat) to 2.28 U/ml (turkey), and glutathione peroxidase from 2.07 U/ml (human) to 27.3 U/ml (rat). Blood samples of the four species were also treated with 0.5-1.5 mM tert-butyl hydroperoxide (t-BOOH) or diamide, and levels of glutathione-derived species [GSH, GSSG, and glutathione-protein mixed disulfides (GS-SP)] were determined within 120 min and related to the corresponding protein -SH group (PSH) reactivities and enzyme repertoires. In all cases t-BOOH rapidly transformed GSH into GSSG by the action of glutathione peroxidase; GSSG was in turn transformed into GS-SP, according to the reaction GSSG + PSH --> GS-SP + GSH, or reduced back to GSH by glutathione reductase. The GSSG reduction was more efficient in rat and human blood, due to the contribution of the fast-reacting -SH of hemoglobin, in the rat, and to the efficiency of the enzyme repertoire of human blood. Calf blood showed a relatively low capacity to restore normal values after oxidative stress, due to its low PSH reactivity and the weak contribution of its enzymes. Diamide treatment, which is known to react nonenzymatically with thiols, gave increased GS-SP levels in rat and turkey, but not in human and calf blood, as expected from the different corresponding PSH reactivities. Species with relatively high PSH reactivity and glucose 6-phosphate dehydrogenase activity, such as the rat, therefore had a higher antioxidant capacity than species (calf) in which these parameters were relatively low.

Animals↗
PubMed1998

DNA ligase I is recruited to sites of DNA replication by an interaction with proliferating cell nuclear antigen: identification of a common targeting mechanism for the assembly of replication factories.

In mammalian cells, DNA replication occurs at discrete nuclear sites termed replication factories. Here we demonstrate that DNA ligase I and the large subunit of replication factor C (RF-C p140) have a homologous sequence of approximately 20 amino acids at their N-termini that functions as a replication factory targeting sequence (RFTS). This motif consists of two boxes: box 1 contains the sequence IxxFF whereas box 2 is rich in positively charged residues. N-terminal fragments of DNA ligase I and the RF-C large subunit that contain the RFTS both interact with proliferating cell nuclear antigen (PCNA) in vitro. Moreover, the RFTS of DNA ligase I and of the RF-C large subunit is necessary and sufficient for the interaction with PCNA. Both subnuclear targeting and PCNA binding by the DNA ligase I RFTS are abolished by replacement of the adjacent phenylalanine residues within box 1. Since sequences similar to the RFTS/PCNA-binding motif have been identified in other DNA replication enzymes and in p21(CIP1/WAF1), we propose that, in addition to functioning as a DNA polymerase processivity factor, PCNA plays a central role in the recruitment and stable association of DNA replication proteins at replication factories.

Amino Acid Sequence↗
PubMed1998

Effects of a high NaCl diet on eating and drinking patterns in pygmy goats.

Eating and drinking patterns of eight pygmy goats were recorded under two diets with different NaCl content. A 3% NaCl diet in comparison to a 0.5% NaCl diet caused a long lasting depression of food intake, whereas water intake did not change. Therefore, the ratio between cumulative water and food intake increased significantly. Feeding the 3% NaCl diet mainly decreased food intake through a decrease in the size (31%) and frequency (16%) of meals which were not associated with drinking. Size and frequency of meals associated with drinking were not substantially affected by the 3% NaCl diet. Size and frequency of drafts were not altered. Size of meals associated with drinking was generally bigger than that of meals not associated with drinking. These findings can best be explained by control of feeding through osmolality of rumen fluid. Ruminal osmolality seems to be less important for control of drinking.

Animals↗
PubMed1998

Treatment of children with relapsed soft tissue sarcoma: report of the German CESS/CWS REZ 91 trial.

BACKGROUND: The present study was performed to evaluate the possibilities of relapse treatment in patients heavily pretreated for a soft tissue sarcoma. PATIENTS AND METHODS: Prospective, multicenter study in 44 soft tissue sarcoma (STS) patients with first relapse. Primary diagnosis was embryonal rhabdomyosarcoma (RME) in 17 patients, alveolar rhabdomyosarcoma (RMA) in 13, primitive neuroectodermal tumor (PNET) in 6, and miscellaneous soft tissue sarcomas in 8 patients. Initial chemotherapy consisted of carboplatin/etoposide combination (150 mg/m2 each, days 1 to 4) followed by local therapy including surgical treatment and, whenever possible, radiotherapy. RESULTS: In 11/17 patients without primary tumor resection, CR or PR was achieved following the initial two cycles of chemotherapy (61%). The probability of event-free survival (pEFS) for RME patients was 0.41 +/- 0.12 at 5 years, and 0.25 +/- 0.12 for RMA patients. But, in contrast no PNET patient or patient with another soft-tissue sarcoma achieved long-term remission. Additional local radiotherapy significantly (P = 0.002) improved pEFS (3-year estimates of 0.23 +/- 0.2 vs. 0.1 +/- 0.1 in patients without radiotherapy). CONCLUSIONS: In patients with RME, relapse treatment employing a carboplatin/etoposide combination may induce a second remission in approximately 40% of patients. Surgical excision and additional local radiotherapy seem to be essential to maintain a stable remission. In patients with RMA or PNET, however, this treatment strategy is of no long-term benefit.

Antineoplastic Agents, Alkylating↗
PubMed1998

The role of cysteine in the regulation of blood glutathione-protein mixed disulfides in rats treated with diamide.

The kinetics of GSH, GSSG, and thiol-protein mixed disulfides (RS-SP) of GSH (GS-SP) and cysteine (CYS-SP) were studied in rat blood and liver in the time range 0-120 min after treatment with 100 and 200 mg/kg i.p. of diamide. Total consumption (10 min) and regeneration (120 min) of blood GSH, matched by parallel increases and decreases in RS-SP, were observed. GSSG did not change appreciably. No dose-effect relationship was obtained with either treatment. On the contrary, in vitro treatment of blood with 0.75 mM diamide provoked the same trends of GSH and RS-SP as in vivo (e.g., reversible modifications), whereas treatment with 1.5 mM caused drops and rises in GSH and RS-SP, respectively, without any subsequent return to control values. The presence of a hematic factor responsible for RS-SP regulation is hypothesized in the in vivo experiment. Successive experiments involving in vitro pretreatment with 2 mM diamide and treatment with 0.5 mM of various thiols indicated that cysteine (CYS), but not GSH or N-acetylcysteine, rapidly restored erythrocyte GSH and RS-SP to their basal levels. No evident sign of hemolysis was observed in these experiments. These results indicate that CYS is a diffusible thiol important for RS-SP regulation. Analysis of whole blood of rats treated with 100 mg/kg i.p. diamide and the presence of two reversible peaks (about 10 times the corresponding control level) of CYS-SP and free CYS confirmed the plausible role of CYS in maintaining the reversibility of the process. Preliminary results in liver of rats treated with 100 mg/kg diamide indicated that CYS may act by metabolic cooperation between organs. We suggest that CYS may have a role in the regulation of the intracellular redox state of rat erythrocytes during oxidative stress.

Animals↗
PubMed1998

Antithrombin III (ATIII) replacement therapy in patients with sepsis and/or postsurgical complications: a controlled double-blind, randomized, multicenter study.

BACKGROUND: ATIII is decreased in sepsis and/or shock and its baseline value correlates with mortality. The efficacy of ATIII therapy on mortality was assessed in a selected group of patients admitted to the intensive care unit (ICU) in a double-blind, randomized, multicenter study. METHODS: 120 patients admitted to the ICU with an ATIII concentration < 70% were randomized to receive ATIII (total dose 24000 units) or placebo treatment for 5 days; 56 patients had septic shock. RESULTS: ATIII concentrations in the treated group remained constant throughout the treatment period (range 97-102%). The Kaplan-Meier analysis showed no difference in overall survival between the two groups: 50 and 46% for ATIII and placebo, respectively. Septic shock and hemodynamic support were unbalanced in the two groups at admission. Therefore the Cox analysis was carried out after adjusting for these two variables. Treatment with ATIII decreases the risk of death with an odds ratio (OR) of 0.56. Of the covariates analyzed, septic shock and the baseline multiple organ failure score were negatively associated with survival and plasma activity level was positively associated with survival with an OR of 0.97 for each 1% increase in the ATIII plasma concentration at baseline. CONCLUSIONS: The results of ATIII treatment in this population of patients suggests that replacement therapy reduces mortality in the subgroup of septic shock patients only.

APACHE↗
PubMed1998

Economic aspects of empiric antibiotic therapy for febrile neutropenia in children with cancer.

Several antibiotic regimens have been proposed worldwide for empiric treatment of febrile neutropenia in children with cancer, but none of them shows clear advantages in terms of clinical efficacy. Therefore, other parameters, including drug acquisition costs, should be considered in the selection of treatment. Children receive a "fraction" of a standard daily dose, and this fraction is generally calculated on the basis of body weight; therefore, the cost of each day of therapy is determined by the packages available for each single drug. We calculated the acquisition costs of various drugs proposed for the empiric treatment of febrile neutropenia in children with cancer, and then we estimated the daily cost of therapy referred to different patient weights. In general, the combination regimen with ceftriaxone plus aminoglycoside turned out to be less expensive than other regimens (including monotherapy with third-generation cephalosporins or carbapenems).

Anti-Bacterial Agents↗
PubMed1998

Modification in serum concentrations of aminoterminal propeptide of type III procollagen in patients with previous transmural myocardial infarction.

The aim of our study was to evaluate the modification of serum concentration of aminoterminal propeptide of type III procollagen (PIIINP) in 70 patients with previous transmural myocardial infarction. In 38 patients (group 1 ) PIIINP levels increased at 6 and 12 months after infarction; in 32 patients (group 2) PIIINP increased at 6 months, returning to baseline at 12 months. At the same time we observed a significant left ventricular enlargement and worsening of the performance in group 1, whereas in group 2 an improvement was seen in left ventricular volumes and performance. In conclusion, rearrangement of collagen myocardial matrix plays an important role in left ventricular postinfarction modification. This process can be easily followed over time in a noninvasive manner by dosing serum PIIINP concentrations.

Aged↗
PubMed1998

Synthesis, characterisation and biological activity of three copper (II) complexes with a modified nitrogenous base: 5-formyluracil thiosemicarbazone.

Three Cu(II) co-ordination compounds with a novel ligand, 5-formyluracil thiosemicarbazone (H3ut), have been synthesised and characterised by single-crystal X-ray diffraction and subsequently tested in vitro on human leukemic cells. The crystal structures revealed, in all three cases, a square pyramidal co-ordination geometry of the copper atom with the ligand lying on the basal plane and behaving as an SNO terdentate ligand. These three compounds have been tested on human leukemic cell line K562 and CEM. In these experiments the complexes have demonstrated to inhibit cell growth and one of them to induce apoptosis. In the paper we also report the spectrophotometric characterization of the free ligand.

Apoptosis↗
PubMed1998

Amylin reduces food intake more potently than calcitonin gene-related peptide (CGRP) when injected into the lateral brain ventricle in rats.

Amylin and the structurally and functionally related peptide calcitonin gene-related peptide (CGRP) have been shown to reduce food intake in rats. The aim of the present study was to compare the anorectic potency of both peptides over a wide dose range when administered into the lateral brain ventricle (ICV). Furthermore, we also tested the influence of a lesion in the area postrema/nucleus of the solitary tract (AP/NTS) region on the anorectic effects of amylin and CGRP after ICV administration because AP/NTS lesion has been shown to reduce the anorectic effects of both peptides when injected intraperitoneally (IP). Amylin [1-510 pmol/rat (0.004-2 microg/rat) ICV] and CGRP [1-131 pmol/rat (0.004-0.5 microg/rat) ICV] dose-dependently reduced food intake in food-deprived rats. At a dose of 26 pmol/rat (0.1 microg/rat), amylin almost completely suppressed food intake for 1 h after injection. Amylin [EC50 = 2 pmol/rat (0.007 microg/rat)] was markedly more potent than CGRP [57 pmol/rat (0.215 microg/rat)] with regard to its anorectic effect. A lesion in the AP/NTS region did not influence the anorectic effects of amylin and CGRP after administration into the lateral ventricle. It is concluded that amylin is more potent than CGRP in reducing food intake after administration into the lateral brain ventricle. Receptors in the forebrain may mediate the anorectic effects of both peptides when administered via this route.

Amyloid↗
PubMed1998

Localization of the repetitive telomeric sequence (TTAGGG)n in four sturgeon species.

We analysed the localization of the telomeric sequence (TTAGGG)n in four species of the genus Acipenser, namely A. naccarii (2n = 246 +/- 6), A. ruthenus (2n = 118 +/- 4), A. gueldenstaedti (2n = 256 +/- 6) and A. baeri (2n = 246 +/- 8). The hybridization signal was localized at the telomeres of all chromosomes in A. naccarii, A. ruthenus and A. baeri. In A. gueldenstaedti, two chromosomes were entirely marked with blocks of telomeric repeating sequences. The results are discussed in the light of their evolutionary inference.

Animals↗
PubMed1998

Distribution of indicator bacteria and bacteriophages in shellfish and shellfish-growing waters.

Shellfish (mussels and clams) and shellfish-growing waters were examined for indicator bacteria according to the EC regulations, Salmonella spp., coliphages and anti-Salmonella phages. Samples were collected both from natural-growing areas along the coast and from authorized shellfish-harvesting beds. The coastal area was affected by organic pollution and extensive faecal contamination and, according to the legal requirements, was unsuitable for shellfish farming. The shellfish collected along the coast also showed faecal contamination at levels which did not conform to legal standards. No significant differences were observed between the frequency of isolation of somatic coliphages and indicator bacteria from sea water. In contrast, both the authorized and wild coastal shellfish were contaminated by coliphages at a significantly higher level than the corresponding bacterial indicators for faecal contamination (chi 2 test, P < 0.01). Coliphage concentrations were significantly correlated with faecal indicators in marine waters (P < 0.001) and sediments (P < 0.05), but no correlation was found in shellfish, thus showing their low specificity as indicators of faecal pollution of human origin in shellfish of economic importance.

Analysis of Variance↗
PubMed1998

Cytokine response to group B streptococcus infection in mice.

This study was undertaken to better understand the complex relationship between specific and non-specific host defence mechanisms and group B streptococci (GBS). A comprehensive kinetics analysis of cytokine mRNA expression was performed, by Northern blot assay, in peritoneal exudate cells (PEC) and spleen cells (SC) recovered from CD-1 mice at various times during the course of an intraperitoneal infection with a lethal dose (5 x 10(3) microorganisms/mouse) of type Ia GBS, reference strain 090 (GBS-Ia). Analysis of cytokines involved in the development of a specific TH response shows that GBS-Ia in PEC induce only a weak increase of IL-2 mRNA expression and in SC a cytokine pattern characterized by IL-2, IFN-gamma and IL-12 in the absence of IL-4, IL-5 and IL-10. This selected cytokine pattern could provide appropriate conditions for the development of a TH1 response. Analysis of inflammatory cytokines, which are usually induced early during an in vivo infection, shows that there is a significant expression of mRNA specific for IL-1beta, TNFalpha and IL-6, both in PEC and SC only at 24 h which persists at a high level until 36 h. This delayed cytokine induction, accompanied by the contemporary activation of splenic phagocytic cells, occurs only when the number of GBS-Ia is extremely high. In fact, at 24 h GBS-Ia have heavily colonized all organs. In vitro infection of thioglycollate-elicited peritoneal macrophages confirms that the ability of GBS-Ia to induce a strong inflammatory cytokine response depends strictly on the number of infecting microorganisms. Indeed, macrophages respond to GBS-Ia with a very rapid induction of IL-1beta and TNFalpha mRNA when infected at a ratio of 1:10, but not at 100:1. Two major observations emerged from this study: (1) GBS-Ia, by inducing a cytokine pattern which seems to favour development of a TH1 response, could evade antibody production essential for resistance to GBS; and (2) inflammatory cytokine response is induced when a heavy microbial invasion of the host has already occurred. These novel features of GBS-Ia could contribute to the development and progression of lethal infection in mice.

Animals↗