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Biomedical subjects

A De Rossi

Publications and source records attributed to A De Rossi.

At least 19 recordsLinked to original sources
PubMed2005

Palliative surgery for gastric cancer in elderly patients.

Poor survival rate of elderly patients affected by locally advanced or metastatic gastric cancer is related to primary tumour complications. Bleeding is the most important adverse event, other major complications are gastric outlet obstruction and nutritional deprivation. Rarely the patients will perforate the stomach cancer and there is a sudden end to their life; contamination of the ascites result in a rapid death. Thus, an aggressive approach toward palliation of this condition is resection: in this manner the expected survival is approximately one year. Derivation techniques or endoscopic treatments are applied in those patients whose operative risk is inacceptable; in these cases poor median survival is expected. The aim of this report in to refer about the experience in palliative surgery for gastric cancer in the Department of Geriatric Surgery of the University of Padua.

Aged↗
PubMed2004

Virological and immunological response to antiretroviral therapy in HIV-1 infected children: genotypic and phenotypic assays in monitoring virological failure.

Children differ from adults in both natural history of HIV-1 infection and their response to anti-retroviral therapy (ART). ART appears to be less successful in children than in adults at reducing HIV-1 RNA to below the level of detection of current assays. Nonetheless, children receiving ART frequently experience rises in CD4 cell counts, even in the absence of full virological suppression in plasma (discordant response). This immune repopulation in the presence of viral replication may increase the risk of emergence of drug-resistant viral variants. While the rationale for resistance testing is to optimise therapy, particularly when drugs are being changed following virological failure, it should be pointed out that currently available genotypic and phenotypic assays fail to detect drug resistance in about one third of viremic ART-treated children. This cannot be fully explained by the limitation of assays in detecting minor variants; factors other than resistance might be involved in the failure of therapy. Reduced fitness of drug-resistant viral variants is also unlikely to fully explain the discordant response to therapy, since immunological recovery is often observed even in the absence of detectable drug resistance. Rather, restoration of thymic function and higher thymic output may play a critical role in sustaining peripheral CD4 cell increases despite the persistence of viral replication. Such immune recovery might also drive the evolution of the replicating viruses.

Anti-HIV Agents↗
PubMed2004

Immune reconstitution in HIV-1 infected children with discordant response to antiretroviral therapies: patterns of HIV-1 env gene evolution driven by restoration of thymic function.

The evolution of human immunodeficiency virus type 1 (HIV-1) env gp120 region was addressed in HIV-1 infected children showing virological failure to antiretroviral therapy (ART). Sequence analysis of the replicating plasma virus at baseline and after one year of therapy documented evolution of gp120 in all subjects but one. Analysis of the host's selective pressure showed that the values of Ka/Ks ratios were higher in the V3 sequence than in the whole C2-V5 region in 4 of 5 children with improvement of thymic output. Moreover, in 2 of the 4 chidren, the V3 evolution paralleled with a reverse shift of the viral phenotype (from CXCR4-tropic to CCR5-tropic). These results suggest that, under ART, the V3 evolution towards less pathogenic viral variants may be driven by the host's increased selective pressure following restoration of thymic function and immune reconstitution.

Amino Acid Sequence↗
PubMed2003

CCR5 N-terminus peptides enhance X4 HIV-1 infection by CXCR4 up-regulation.

The HIV-1 envelope glycoprotein gp120 interacts consecutively with CD4 and CCR5 to mediate the entry of R5-HIV-1 strains into target cells. The N-terminus of CCR5, which contains several sulfated tyrosines, plays a critical role in gp120-CCR5 binding and, consequently, in viral entry. Here, we demonstrate that a tyrosine sulfated peptide, reproducing the entire N-terminal extracellular region of CCR5, its unsulfated analogue, and a point-mutated peptide are unable to inhibit R5-HIV-1 mediated infection, competing with the entire CCR5 in the formation of gp120-CD4-CCR5 complex. Surprisingly, these peptides show the capability of enhancing HIV-1 infection caused by X4 strains through the up-regulation of both CD4 and CXCR4 receptors.

Amino Acid Sequence↗
PubMed2003

Determination of trenbolone and its metabolite in bovine fluids by liquid chromatography-tandem mass spectrometry.

A liquid chromatographic-tandem mass spectrometric (LC-MS-MS) method has been developed for the determination of trenbolone in bovine urine and serum. The aim was a control of the misuse of trenbolone in food-producing animals. The procedure involved, in both cases, a preliminary solid-phase clean-up followed by a liquid-liquid extraction for urine samples after a preliminary enzymatic hydrolysis. The extracts have been directly analysed by reversed-phase LC-MS-MS in selected reaction monitoring (SRM), acquiring two diagnostic product ions from the chosen precursor [M+H](+). The procedures were validated across the concentration range of 1-1500 ng/ml. The linearity, the inter- and intra-day accuracy and precision have been determined. The procedure was specific and the accuracy values were better than 20% at the limit of quantitation of spiked samples. The limit of quantification (LOQ) and the limit of detection (LOD) were, respectively, 1 ng/ml and 350 pg/ml for urine and serum. According to the draft, SANCO/1805/2000, we determined the decision limit CCalpha and the detection capability CCbeta. The recovery values for urine ranged from 87 to 128%, and for plasma the recovery was 70+/-4%. The procedure proved to be simple and suitable for routine and confirmatory purposes such as those developed for residue studies.

Animals↗
PubMed2002

Counterpropagating twin photons by parametric fluorescence.

An original geometry for parametric fluorescence is proposed and analyzed theoretically, in which counterpropagating twin photons are emitted in a thin waveguide. In this original down-conversion process, a dramatic decrease of the spectral signal bandwidth at degeneracy is expected, as compared to usual parametric fluorescence processes. The possibility of using the counterpropagating twin photons for quantum cryptography is emphasized. It is shown that the realization of a fibered semiconductor source of Einstein-Podolsky-Rosen photons is possible by this method.

Journal Article↗
PubMed2001

Polymorphisms in the CCR5 promoter region influence disease progression in perinatally human immunodeficiency virus type 1-infected children.

The effect of CC-chemokine receptor 5 (CCR5) promoter polymorphisms on the natural history of human immunodeficiency virus (HIV) disease was studied in 73 HIV-1-infected children. The CCR5(59338-59537) promoter haplotype, CCR5-59029A/G polymorphism, and CCR5Delta32 and CCR2-64I alterations were investigated. After exclusion of carriers of CCR5Delta32 or CCR2-64I, Kaplan-Meier analysis disclosed that children with the P1/P1(59353C,59356C,59402A) genotype progressed faster to disease than did children with other haplotypes (P=.016). When CCR2-64I carriers were included, this effect had borderline significance (P=.065) and was lost when CCR5Delta32 carriers were also considered (P=.387). The P1/P1 effect was strongest early after infection, when progression to disease was mainly associated with CCR5 coreceptor-using viruses. These results indicate that the P1/P1 genotype is predictive of rapid progression in HIV-1-infected children lacking CCR5Delta32 or CCR5-64I alleles. The observation of a linkage disequilibrium between P1 and 59029A might explain the previously reported association between 59029A homozygosity and rapid disease progression.

Adolescent↗
PubMed2001

Esthetic options for the fabrication of removable partial dentures: a clinical report.

This clinical report describes a procedure for influencing the esthetics of a Kennedy Class III-Modification 1 removable partial denture. The acrylic resin base is eliminated, and the retentive clasp placed on the first premolars is modified. This technique is simple and inexpensive, and in the treatment presented, it resulted in complete patient satisfaction.

Acrylic Resins↗
PubMed2001

Acquired immunodeficiency syndrome-related Kaposi's sarcoma regression after highly active antiretroviral therapy: biologic correlates of clinical outcome.

BACKGROUND: Kaposi's sarcoma (KS) is the most common cancer seen in subjects with acquired immunodeficiency syndrome (AIDS). KS etiology and pathogenesis are still ill defined, and no definite improvement in survival has been obtained with current chemotherapeutic regimens. This open prospective study was aimed at evaluating the clinical response of AIDS-related KS to highly active antiretroviral therapy (HAART), a combination of protease and reverse transcriptase inhibitors, as well as the relationship between clinical response, human immunodeficiency virus type 1 (HIV-1) burden, and antibody titer against human herpesvirus 8 (HHV8) proteins. PATIENTS AND METHODS: Fourteen KS patients were studied; 12 were in the poor-risk group. At given intervals, the patients underwent clinical examination, and their CD4(+) cell counts, plasma HIV-1 RNA levels, and antibody titers to lytic-phase ORF65 and latent-phase HHV8 proteins were determined. RESULTS: When last seen, the overall clinical response rate was 86% (median follow-up, 22 months); 10 complete and two partial responses were achieved, and two patients showed disease progression. All patients with complete or partial response showed a consistent decrease in HIV-1 RNA levels, with a corresponding increase in CD4(+) cell counts; HIV-1 RNA levels in the two progressors remained persistently high, despite a change in HAART. HHV8 ORF65 antibody titers were generally higher in patients with extensive skin or mucosal/visceral involvement versus patients with limited disease; no differences in latent-phase HHV8 antibody titers were observed in relation to tumor burden. CONCLUSION: The findings indicate that antiretroviral therapy with protease inhibitors is effective for AIDS-related KS; the clinical response was correlated with a decrease in plasma HIV-1 RNA levels and an increase in CD4(+) lymphocytes, whereas antibody levels to the lytic-phase HHV8 protein were influenced by the extent of tumor involvement.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Telomerase activity and clinical progression in chronic lymphoproliferative disorders of B-cell lineage.

The activation of telomerase, which specifically occurs in neoplastic cells to avoid telomere attrition at each cell division, is a necessary event in tumorigenesis. The evidence that telomerase is also present in normal B cells at different levels according to their differentiation and activation state makes the study of telomerase activity in B cell tumors particularly interesting. This review summarizes data concerning telomerase activity in chronic lymphoproliferative disorders of B-cell lineage (B-CLD), making suggestions regarding B-cell development and B-cell tumor histogenesis. The role of telomerase activity as a potential prognostic marker, as well as a target of new antineoplastic strategies is discussed.

B-Lymphocytes↗
PubMed2000

Co-receptor usage of HIV-1 primary isolates, viral burden, and CCR5 genotype in mother-to-child HIV-1 transmission.

OBJECTIVE: To investigate the relationship between CC chemokine receptor 5 (CCR5) genotype, viral load and co-receptor usage of maternal HIV-1 isolates in perinatal HIV-1 transmission. PATIENTS AND METHODS: A total of 181 mothers and infants were studied at the time of delivery. Wild-type (wt) and delta32 CCR5 alleles were determined by means of polymerase chain reaction (PCR). The viral load in maternal plasma samples was determined by a quantitative reverse transcriptase-PCR assay; co-receptor usage of maternal isolates was determined by viral infection in cells stably expressing CCR5 or CXC chemokine receptor 4 (CXCR4) co-receptors. RESULTS: HIV-1 transmission rates in wt/wt and wt/delta32 mothers (14.7 versus 15.8%), and in wt/wt and wt/delta32 infants (14.6 versus 14.3%) were similar. Mothers transmitting infection to wt/delta32 infants had significantly higher HIV-1-RNA levels than those who transmitted infection to wt/wt infants (5.4 versus 4.1 log10 copies/ml, P = 0.03). In wt/wt children there was a positive relationship between transmission rate and maternal viral load over the entire range of HIV-1 values, whereas in wt/delta32 children transmission occurred only at viral loads greater than 4.0 log10 copies/ml. Logistic regression analysis confirmed that the relationship between viral load and transmission varied according to the child's CCR5 genotype (P = 0.035; adjusted for zidovudine prophylaxis and mode of delivery, P = 0.090). Moreover, the majority of wt/wt transmitting mothers had R5-type isolates, whereas none of the wt/delta32 mothers with an R5-type virus transmitted HIV-1 to their wt/delta32 infants. CONCLUSION: Taken together, these findings suggest that CCR5 delta32 heterozygosity exerts a protective effect against perinatal transmission in children exposed to a low maternal viral burden of an R5-type isolate.

Cetirizine↗
PubMed2000

Vulvar carcinoma in a 12-year-old girl with vertically acquired human immunodeficiency virus infection.

We report the first case of a girl with vertically acquired human immunodeficiency virus (HIV) infection, who developed invasive squamous cell carcinoma of the vulva at 12 years of age. Lesions resembling bowenoid papulosis covered the perianal area as well. She underwent a nonmutilating surgical excision of the infiltrating lesion. More than 3 years later, her clinical condition is excellent, although dysplastic, noninfiltrating multifocal lesions persist. This case highlights the need to perform careful periodic genital examinations in all HIV-infected children and adolescents born to HIV-positive mothers.

CD4 Lymphocyte Count↗
PubMed2000

Late Epstein-Barr virus infection of a hepatosplenic gamma delta T-cell lymphoma arising in a kidney transplant recipient.

BACKGROUND AND OBJECTIVE: gd T-cell lymphomas are only exceptionally observed in transplanted patients. Aim of this study was the detailed characterization of one such case. DESIGN AND METHODS: The patient developed spontaneous splenic rupture six years after kidney transplantation. The splenic red pulp was infiltrated by medium-sized and large lymphoid cells with two or more nucleoli. At autopsy, similar lymphoid cells infiltrated the hepatic sinusoids. Histologic, immunologic and molecular studies were carried out. RESULTS: By immunohistochemistry, the atypical lymphoid cells were found to express CD3, CD45 and CD43, indicating their T-lineage origin. Approximately 99% of spleen mononuclear cells (MNC) were CD3(+), gammadelta TcR+, CD4-, CD8-, alphabeta TcR-. A clonal gammadelta TcR rearrangement (Vgamma1-Jgamma1.3/2.3-Cgamma2; Vdelta1-Ddelta2-Jdelta1) was detected. The final diagnosis was peripheral T-cell lymphoma, hepato-splenic gammadelta-type. EBV infection of spleen MNC was documented by molecular studies. However, in situ hybridization for EBER-1 (EBV-RNA) showed that only a minority of malignant lymphoid cells (5-7%) were EBV-infected. INTERPRETATION AND CONCLUSIONS: It is concluded that EBV infection was as a late event involving an already transformed gd T-cell clone.

Adult↗
PubMed1999

Restriction of HIV type 1 infection in macrophages heterozygous for a deletion in the CC-chemokine receptor 5 gene.

Homozygosity for a 32-base pair deletion (delta32) within the CC-chemokine receptor 5 (CCR5) gene confers resistance to infection by R5-type HIV-1 isolates. To ascertain how CCR5delta32 heterozygosity influences the susceptibility of lymphocytes and macrophages to HIV-1 infection, peripheral blood lymphocytes (PBLs) and monocyte-derived macrophages (MDMs) from three HIV-1-uninfected CCR5delta32 heterozygous infants and three HIV-1-uninfected CCR5 wild-type homozygous infants were exposed to two R5-type primary isolates. HIV-1 infection was monitored by DNA-PCR and p24 antigen determination; CCR5 and CCR5delta32 transcripts were quantified by competitive reverse transcription-PCR. Wild-type homozygous MDMs and PBLs and heterozygous PBLs were infected by both viral isolates, albeit with different efficiencies, but heterozygous MDMs showed restriction to HIV-1 infection. Lower levels of CCR5 mRNA and protein expression were found in heterozygous versus wild-type homozygous MDMs and PBLs. Interestingly, wild-type homozygous MDMs showed higher levels of CCR5 mRNA expression compared with wild-type homozygous PBLs, while heterozygous MDMs had lower levels of CCR5 wild-type mRNA and a higher CCR5delta32/CCR5 mRNA ratio compared with heterozygous PBLs. These findings suggest that CCR5delta32 heterozygosity confers a different degree of protection against HIV-1 in PBLs and MDMs, depending on the ratio of wild-type and mutant CCR5 mRNA in the two cell types, and may delay virus spread in the host by preventing infection of monocytes and macrophages.

Adult↗