Biomedical subjects

L Rossi

Publications and source records attributed to L Rossi.

At least 109 records · Page 6Linked to original sources

PubMed2000

Saccharomyces cerevisiae fungemia in a neutropenic patient treated with Saccharomyces boulardii.

A case of Saccharomyces fungemia in an 8-month-old baby affected by acute myeloid leukemia while receiving intensive chemotherapy is reported. The patient was receiving prophylaxis treatment with Saccharomyces boulardii capsules (Codex) to prevent diarrhea, which is commonly associated with this type of chemotherapy. Fever spiked just the day after ending the chemotherapy course, and a strain of Saccharomyces cerevisiae was isolated from blood culture although the patient was also receiving antifungal prophylaxis with fluconazole. The patient recovered, though still neutropenic, with amphotericin-B and removal of the central venous catheter. The common biochemical characteristics make it difficult to differentiate between the strain of Saccharomyces cerevisiae and that of Saccharomyces boulardii with routine methods. In other cases, authors demonstrated an identity between the two strains with a more detailed analysis. These reports raise concern about the potential side effects of such biotherapeutic agents.

Antifungal Agents↗

PubMed2000

A new acyclic heterodinucleotide active against human immunodeficiency virus and herpes simplex virus.

The most common therapies against human herpes virus (HSV-1) and human immunodeficiency virus (HIV-1) infectivity are based on the administration of nucleoside analogues. Acyclovir (ACV) is the drug of choice against HSV-1 infection, while the acyclic nucleoside phosphonate analogue PMPA has shown marked anti-HIV activity in a phase I and II clinical studies. As monocyte-derived macrophages are assumed to be important as reservoirs of both HSV-1 and HIV-1 infection, new approaches able to inhibit replication of both viruses in macrophages should be welcome. ACVpPMPA, a new heterodinucleotide consisting of both an antiherpetic and an antiretroviral drug bound by a phosphate bridge, was synthesized and encapsulated into autologous erythrocytes modified to increase their phagocytosis by human macrophages. ACVpPMPA-loaded erythrocytes provided an effective in vitro protection against both HSV-1 and HIV-1 replication in human macrophages.

Animals↗

PubMed2000

Morning recall of verbal material depends on prior sleep organization.

Despite the evidence that sleep may facilitate memory, controversial findings concern the role of sleep states (NREM, REM). We put forward the hypothesis that sleep organization, i.e. the regular occurrence of NREM-REM cycles, more than sleep states per se, may be crucial for the retention of verbal material presented before sleep. An experiment was performed in which recall of verbal material was requested of young subjects after three different kinds of night sleep: undisturbed sleep, fragmented sleep without sleep cycles disorganization, and fragmented sleep interrupted with sleep disorganization. Morning recall of verbal material was impaired after the night with disturbed sleep cycles, whereas it was not after the night with preserved sleep cycles; the amount of REM was similar in both cases. We conclude that the recall of verbal material is greatly affected by sleep cycle disorganization.

Adult↗

PubMed2000

Evidence of poly(ADP-ribosylation) in the cockroach Periplaneta americana.

Poly(ADP-ribosylation) is a post-translational modification of nuclear proteins typical of most eukaryotic cells. This process participates in DNA replication and repair and is mainly regulated by two enzymes, poly(ADP-ribose) polymerase, which is responsible for the synthesis of polymers of ADP-ribose, and poly(ADP-ribose) glycohydrolase, which performs polymer degradation. The aim of this work was to investigate in the cockroach Periplaneta americana L. (Blattaria: Blattidae) the behaviour of poly(ADP-ribosylation). In particular, we addressed: (i) the possible modulation of poly(ADP-ribosylation) during the embryonic development; (ii) the expression of poly(ADP-ribose) polymerase and glycohydrolase in different tissues; and (iii) the role of poly(ADP-ribosylation) during spermatogenesis. In this work we demonstrated that: (i) as revealed by specific biochemical assays, active poly(ADP-ribose) polymerase and glycohydrolase are present exclusively in P. americana embryos at early stages of development; (ii) an activity carrying out poly(ADP-ribose) synthesis was found in extracts from testes; and (iii) the synthesis of poly(ADP-ribose) occurs preferentially in differentiating spermatids/spermatozoa. Collectively, our results indicate that the poly(ADP-ribosylation) process in P. americana, which is a hemimetabolous insect, displays catalytical and structural features similar to those described in the holometabolous insects and in mammalian cells. Furthermore, this process appears to be modulated during embryonic development and spermatogenesis.

Animals↗

PubMed2000

Paratuberculosis in red deer (Cervus elaphus hippelaphus) in the western Alps.

During the hunting seasons 1995-96 to 1997-98, 19 red deer from the Upper Susa Valley (Cottian Alps) were examined for paratuberculosis (Johne's disease). Specific DNA amplification on mesenteric lymph nodes detected Mycobacterium avium paratuberculosis in 17 animals. Ten of these red deer were tested for serum antibodies by the AGID and ELISA tests, nine being negative. Three isolates from infected deer were genetically characterized by an arbitrarily primed polymerase chain reaction, and showed similar genetic polymorphism to that of bovine strains isolated in different Italian areas. The study showed that paratuberculosis is present in red deer of the Upper Susa Valley and that serological tests are not an efficient means for monitoring this infection.

Animals↗

PubMed2000

The antiproliferative effect of beta-carotene requires p21waf1/cip1 in normal human fibroblasts.

In normal human fibroblasts, beta-carotene induces a cell-cycle delay in the G1 phase independent of its provitamin A activity via a mechanism not yet elucidated. In this study we provide biochemical evidence showing that delayed progression through the G1 phase occurs concomitantly with: an increase in both nuclear-bound and total p21waf1/cip1 protein levels; an increase in the amount of p21waf1/cip1 associated with cdk4; the inhibition of cyclin D1-associated cdk4 kinase activity; and a reduction in the levels of hyperphosphorylated forms of retinoblastoma protein, and particularly, in phosphorylated Ser780. The role of p21waf1/cip1 in the antiproliferative effect of the carotenoid was further supported by genetic evidence that neither changes in cell-cycle progression nor in the phosphorylation status of retinoblastoma protein were observed in p21waf1/cip1-deficient human fibroblasts treated with beta-carotene. These results clearly demonstrate that p21waf1/cip1 is involved directly in the molecular pathway by which beta-carotene inhibits cell-cycle progression.

Cell Cycle↗

PubMed2000

Detection of Mycobacterium tuberculosis complex in lymph nodes of wild boar (Sus scrofa) by a target-amplified test system.

A detailed macroscopic and histological description is given of tuberculous-like lesions in mandibular lymph nodes obtained from wild boar (Sus scrofa) collected in Italy during the 1995/1996 hunting season, as well as a correlation with results obtained from a Mycobacterium tuberculosis complex target amplified test system. According to macroscopic appearance, lesions were largely represented by caseous-necrotic-calcified granulomata (n = 272/285; 95.4%), while histological investigations showed mainly necrotic-calcified (n = 82/218; 37.6%) and fibronecrotic-calcified (n = 81/218; 37.2%) lesions. When tested with a target rRNA amplification/hybridization technique to detect M. tuberculosis complex, 112 (43.6%) samples out of 275 tested gave positive results.

Animals↗

PubMed2000

Collagen cross-links and early postnatal growth in newborns with intrauterine growth retardation.

This study assessed growth and skeletal metabolism in full-term newborns with intrauterine growth retardation (IUGR) and determined the value of the urinary excretion of collagen cross-links in predicting postnatal catch-up growth. We studied 38 newborns (16 females) born at term with a birth weight less than the 10th centile of the reference and a ponderal index ([PI] 100 x weight in g/length in cm3) of 2.27 +/- 0.19. The sample was divided into 23 children with proportionate ([P] PI > or = 10th centile of the reference) and 15 with nonproportionate ([NP] PI < 10th centile of the reference) IUGR. The weight, head circumference, length, and knee-heel length of the newborns at days 7, 14, 30, 60, and 90 were measured. The height of 23 of the 38 children was also assessed at 27 +/- 6 months of life. Urinary collagen cross-links were analyzed by high-performance liquid chromatography at day 14 and day 60. Most of the infants (68%) underwent catch-up growth, and the growth performance at 3 months was independent of the proportions at birth. Children who did not show catch-up growth in the first trimester of life failed to normalize in height in the following 2 years. The urinary excretion of pyridinoline (Pyd) was not related to the anthropometric measurements. In P children, urinary excretion of deoxypiridinoline (Dpd) at day 14 significantly correlated with the gain in length during the first 3 months, accounting for 25% of the variance. In NP children, these correlations between urinary Dpd and the gain in length were not significant. The evaluation of urinary Dpd excretion at 2 weeks of age might help to determine the therapeutic regimen in IUGR children.

Anthropometry↗

PubMed2000

European priorities for research to support legislation in the area of food contact materials and articles.

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.

Decision Making↗

PubMed2000

Hepatocellular carcinoma complicating liver cirrhosis in type IIIa glycogen storage disease.

Type III glycogen storage disease (GSD III) is an autosomal recessive disorder characterized by the accumulation of abnormal glycogen in the liver and, in most patients, in the muscle. Although liver fibrosis is a well-known consequence of GSD III, until now only eight cases of liver cirrhosis and two cases of hepatocellular carcinoma have been described in patients affected by this disease. In this case report, the authors describe the clinical history of a patient affected by GSD III who developed severe liver disease during her adult life, progressing from fibrosis to cirrhosis and finally to hepatocellular carcinoma. Until now, the hepatic involvement in GSD III has been considered by most authors as mild and almost always self-limiting. This report, together with the previously published cases, clearly indicates that severe and progressive liver disease may complicate this metabolic disorder. These observations advise a careful hepatologic follow-up of patients affected by GSD III.

Carcinoma, Hepatocellular↗

PubMed2000

Mycobacterium paratuberculosis infection in two free-ranging Alpine ibex.

The authors report two cases of Mycobacterium paratuberculosis infection in free-ranging Alpine ibex (Capra ibex) from two different herds in the Western Alps, Italy. One ibex, found dead in October 1998, was in poor condition. The second animal died due to trauma following capture with a dart gun. The only gross lesions observed were the enlargement of the mesenteric and iliac lymph nodes. Samples from both ibex tested positive to polymerase chain reaction for a primer set specific for the M. paratuberculosis insertion sequence IS900 and one ibex also tested positive to the Zielh-Nielsen stain. Isolation by bacterial culture was not successful. The infected ibex originated from herds in which seroreactors to M. paratuberculosis had been found previously. Seroreactors to M. paratuberculosis were also detected in sympatric cattle.

Animals↗

PubMed2000

[Clinical considerations and statistical analysis on 100 patients with oral lichen planus].

BACKGROUND: Oral Lichen planus (OLP) is an inflammatory disease, characterized by the presence of polygonal papules which can confluence and affect any part of the oral mucosa, and occurring in many different forms. The clinical picture of the popular form may be characterized exclusively by asymptomatic whitish striae, while the erosive form is extremely painful and disabling. The aim of this research was to evaluate the behavior of the reticular and erosive form of OLP taking into consideration the following three pathologies: hepatitis B, C and diabetes. METHODS: The data of 100 patients affected by OLP (43 males and 57 females) where analyzed, the patients have been observed at the G. Eastman hospital in Rome, Italy in the period between November 1995 and May 1998. Group I presented papular lesions, while group II presented atrophic-erosive lesions with or without the presence of papular lesions. RESULTS: A comparative analysis between the two groups, performed with chi 2 corrected by the Yates formula and if necessary followed by the Fisher test, demonstrated a higher average age and a larger extension of the oral lesions for group II (p < 0.05). The presence of viral hepatitis B was 6% overall, its prevalence in group II, 5% (p > 0.05); the presence of viral hepatitis C was 13% overall, its prevalence in group II 11%; the presence of diabetes was 10% overall, its prevalence in group II 7%. The buccal mucosa was the most frequently affected area in both groups. CONCLUSIONS: The results obtained confirm the possibility of an association between hepatitis and OLP, but a statistically significant relationship between hepatitis and OLP erosive type, has not been observed.

Adult↗

PubMed1999

Metabolism, mitochondrial uptake and toxicity of 2', 3'-dideoxycytidine.

2',3'-Dideoxycytidine (ddCyd) is a prescription anti-retroviral drug that causes mitochondrial toxicity and peripheral neuropathy. ddCyd is actively phosphorylated by cytosolic deoxycytidine kinase and nucleoside (di)phosphate kinase to the 5'-triphosphate derivative. However, 2',3'-dideoxycytidine 5'-diphosphocholine (ddCDP-choline) was also found in human cells incubated with ddCyd. In this paper we show that ddCDP-choline is produced from dideoxyCTP (ddCTP) and phosphocholine by phosphocholine cytidylyltransferase. dCTP and CTP appear to activate this synthesis in a concentration-dependent manner. Although ddCTP and ddCDP-choline can both enter the mitochondria, ddCDP-choline uptake is more efficient than ddCTP uptake. These data suggest that ddCDP- choline is the ddCyd metabolite that is probably responsible for mitochondrial toxicity. The uptake of ddCTP and ddCDP-choline by mitochondria is inhibited by 3.0 mM l-carnitine in the cell-free system investigated; when added to U937 cells grown in the presence of 0.25 microM ddCyd, 3.0 mM l-carnitine partially abrogated the mitochondrial toxicity of ddCyd.

Animals↗

PubMed1999

Histologic findings in the conduction system after cardiac transplantation and correlation with electrocardiographic findings.

The study of the sinus node and the specialized atrioventricular junction by serial sections in cardiac transplantation revealed that acute rejection involving the conduction system was equally severe as the working myocardium, with the exception of the His bundle. During acute rejection, the sudden appearance of a first-degree atrioventricular block may suggest severe involvement of the conduction system with impending cardiac arrest.

Adult↗

PubMed1999

Anatomic study of the pelvis in carcinoma of the uterine cervix as related to the box technique.

PURPOSE: To review the radiation therapy "box" technique for cancer of the cervix by means of magnetic resonance imaging (MRI), lymphangiography, and anatomic studies on cadavers. METHODS AND MATERIALS: From 1993 to 1996, the anatomic borders of the "box" technique used at our Radiation Oncology Department-the superior border of the AP-PA fields at the inferior edge of L4; the inferior border at the inferior edge of the ischium; the lateral borders placed 2.5 cm outside of the bony pelvis rim; the anterior border of the lateral fields over the anterior edge of the pubic symphysis; and the posterior at the S2-S3 interspace-were reviewed in 35 sagittal MRI and 10 lymphangiographies of patients with FIGO IB (6), IIA (6), IIB (19), IIIB (3), and IVA (1). An anatomic revision was conducted on 30 cadavers to identify aortic bifurcation, lymphatic nodes, and uterus flexion. RESULTS: In 50% of the patients with FIGO IB, the posterior border of the lateral field was inadequate to encompass the planning target volume (PTV), and in 67% with Stage IIA. In IIB, the anterior border was inadequate in 1 patient, and the posterior in 8 (42%). In IIB and IVA patients, the PTV was not encompassed. When correlating the anterior and posterior borders of the lateral field and the treatment volume in the 35 sagittal MRIs, the posterior border of the lateral field was inadequate in 49%, and the anterior border in 9% of the cases. According to the lymphangiography, the portals encompassed the external iliac nodes. Dissected female pelvises revealed that the aortic bifurcation occurred at the level of the inferior L4 edge in 80% of the cadavers. There was no correlation between uterus flexion in MRIs and in cadavers. CONCLUSION: The design of the lateral fields of the four-field technique for the irradiation of the uterine cervix based on anatomic bone references failed to encompass the planning-target volume in a significant number of patients.

Cadaver↗

PubMed1999

Import of DNA into mammalian nuclei by proteins originating from a plant pathogenic bacterium.

Import of DNA into mammalian nuclei is generally inefficient. Therefore, one of the current challenges in human gene therapy is the development of efficient DNA delivery systems. Here we tested whether bacterial proteins could be used to target DNA to mammalian cells. Agrobacterium tumefaciens, a plant pathogen, efficiently transfers DNA as a nucleoprotein complex to plant cells. Agrobacterium-mediated T-DNA transfer to plant cells is the only known example for interkingdom DNA transfer and is widely used for plant transformation. Agrobacterium virulence proteins VirD2 and VirE2 perform important functions in this process. We reconstituted complexes consisting of the bacterial virulence proteins VirD2, VirE2, and single-stranded DNA (ssDNA) in vitro. These complexes were tested for import into HeLa cell nuclei. Import of ssDNA required both VirD2 and VirE2 proteins. A VirD2 mutant lacking its C-terminal nuclear localization signal was deficient in import of the ssDNA-protein complexes into nuclei. Import of VirD2-ssDNA-VirE2 complexes was fast and efficient, and was shown to depended on importin alpha, Ran, and an energy source. We report here that the bacterium-derived and plant-adapted protein-DNA complex, made in vitro, can be efficiently imported into mammalian nuclei following the classical importin-dependent nuclear import pathway. This demonstrates the potential of our approach to enhance gene transfer to animal cells.

Agrobacterium tumefaciens↗

PubMed1999

Heterodimer-loaded erythrocytes as bioreactors for slow delivery of the antiviral drug azidothymidine and the antimycobacterial drug ethambutol.

Disseminated infection with Mycobacterium avium complex (MAC) remains the most common serious bacterial infection in patients with advanced AIDS. The organisms that make up this complex are found ubiquitously in the environment, yet rarely cause disseminated disease in nonimmunocompromised human patients; on the contrary, up to 50% of patients with AIDS may ultimately develop the pathology. Hence, therapeutic strategies able to inhibit HIV and Mycobacterium replication are needed. Because of the rapid plasma elimination and toxicity of the most commonly used drugs, daily multiple-drug therapies must often be continued throughout life, frequently causing major side effects and, as a consequence, poor patient compliance. Therefore, alternative strategies that reduce the toxicity of the drugs and allow prolonged application intervals are sorely needed. Since erythrocytes (RBCs) can behave as bioreactors able to convert impermeant prodrugs to membrane-releasable active drugs, new compounds (AZTpEMB, AZTpEMBpAZT, and AZTp2EMB) consisting of both an antiretroviral and an antimicrobial drug were designed and synthesized. Among these, only AZTp2EMB was hydrolyzed by erythrocyte enzymes and could be encapsulated inside RBCs. AZTp2EMB-loaded RBCs slowly released AZT and EMB in culture medium, reducing its concentration by one-half about every 48 hr of incubation at 37 degrees C. Moreover, when AZTp2EMB-loaded erythrocytes were incubated for 6 days in the presence of human macrophages infected with Mycobacterium avium (M. avium) a marked bactericidal effect (>1 log) was observed. Thus, AZTp2EMB-loaded erythrocytes could be used as endogenous bioreactors for AZT and EMB delivery in the treatment of HIV and M. avium infection.

Anti-HIV Agents↗

PubMed1999

Substituted indole-2-carboxylates as potent antagonists of the glycine binding site associated with the NMDA receptor.

A novel series of indole-2-carboxylate analogues of GV150526 (1) in which the propenoic double bond was substituted with different "probes" or replaced by a isosteric cyclopropyl moiety were synthesized and evaluated for their affinity profile in order to obtain further information on the pharmacophoric model of the glycine binding site associated to the NMDA receptor.

Animals↗