Biomedical subjects

F Cocchi

Publications and source records attributed to F Cocchi.

27 records · Page 2Linked to original sources

PubMed1995

In vitro anti-HIV-1 antibody production in subjects in different stages of HIV-1 infection.

We evaluated the in vitro antibody production from peripheral blood mononuclear cells (PBMC) against HIV-1 proteins in infected adults. Fifty-four HIV-1 infected patients (four recent seroconverters, 15 asymptomatics with a CD4 count higher than 500/microliters, 27 asymptomatics with a CD4 count between 200 and 500/microliters and eight symptomatic patients) were tested. PBMC were incubated in the presence or absence of 1% pokeweed mitogen (PWM) at 37 degrees C for 8 days. Western blot assay, p24 antigen ELISA and anti-p24 antibody ELISA were performed on serum and culture supernatants. Spontaneous production of anti-env antibody in culture supernatants was evidenced in all subjects. All the positive supernatants for anti-core antibodies (18/54) were derived from asymptomatic patients. PBMC from recent seroconverters and from symptomatic patients did not produce any anti-core antibody. Antibody production decreased after stimulation with PWM. The concentration of p24 antigen did not significantly increase in p24 positive supernatants following acidification (P = 0.1), suggesting that the inability to detect p24 antibody was not due to the anti-p24 antibody complexed to p24 antigen in culture supernatants. In vitro production of anti-p24 antibodies was significantly more frequent in asymptomatic subjects with high CD4+ cell counts (P = 0.02) and was absent in recent seroconverters. This last finding suggests that during the initial phases of the infection, anti-p24 antibody production may be restricted to cells residing in lymphoid organs. In addition, the lower percentage of anti-core antibody in people with low CD4+ cell counts is not merely a consequence of the binding of the antibody to an increased amount of antigen, but probably reflects an impaired production or a sequestration of producing cells in lymphoid tissue during the late stages of the infection.

Acquired Immunodeficiency Syndrome↗

PubMed1995

Growth of macrophage-tropic and primary human immunodeficiency virus type 1 (HIV-1) isolates in a unique CD4+ T-cell clone (PM1): failure to downregulate CD4 and to interfere with cell-line-tropic HIV-1.

Human immunodeficiency virus type 1 (HIV-1) isolates derived directly from clinical samples are usually unable to grow in cytokine-independent continuous cell lines, thus hindering the study of their biological features and their sensitivity to humoral and cellular protective immunity. To overcome these limitations, we have derived from the Hut78 T-cell line a CD4+ clone (PM1) characterized by a unique susceptibility to a wide range of HIV-1 isolates, including primary and biologically pure macrophage (M phi)-tropic isolates (e.g., HIV-1BaL), which are unable to infect other human T- or promonocytic cell lines. Both primary and M phi-tropic HIV-1 establish persistent infection in PM1, with sustained levels of virus replication for prolonged periods. Experiments with chimeric viruses containing envelope fragments of HIV-1BAL inserted into the genetic framework of HXB2, a molecular clone derived from the cell-line-tropic isolate HIV-1IIIB, showed the third hypervariable domain (V3) of gp120 to be a critical determinant of the cell line tropism of HIV-1. Nevertheless, the V3 loop of HIV-1BaL was not sufficient to confer on the chimeras a bona fide M phi tropism. The biological characteristics of HIV-1BaL and of a primary isolate (HIV-1(573)) were investigated by using the PM1 clone. Infection of PM1 by HIV-1BaL was critically dependent on the CD4 receptor, as shown by competition experiments with an anti-CD4 monoclonal antibody (OKT4a) or with soluble CD4. However, the amount of soluble CD4 required for inhibition of HIV-1BaL was approximately 100-fold higher than for HIV-1IIIB, suggesting that the affinity of HIV-1BaL for CD4 is significantly lower. Infection of PM1 with either HIV-1BaL or HIV-1(573) failed to induce downregulation of surface CD4 expression and syncytium formation. Analogous results were obtained with a chimeric virus (HXB2[BaL PvuII-BamHI]) encompassing a large portion of gp120 and gp41 of HIV-1BaL, indicating that the env genes contain critical determinants for CD4 downregulation and syncytium formation. Consistent with the lack of CD4 downregulation, persistent infection of PM1 by HIV-1BaL or HIV-1(573) failed to interfere with HIV-1IIIB superinfection, as revealed by the expression of a type-specific V3 loop epitope (M77) and by the induction of extensive syncytium formation. This lack of interference suggests that a direct viral interaction may occur in vivo between biologically diverse HIV-1 strains.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗

PubMed1994

Eating disorder inventory in the assessment of psychosocial status in the obese patients prior to and at long-term following biliopancreatic diversion for obesity.

Psychological traits of obese patients, assessed with the Eating Disorder Inventory (EDI), were compared to those of subjects in the long-term following biliopancreatic diversion for obesity (BPD), when body weight has been steadily normal for over 1 year and any preoccupation with dieting and weight has been completely abandoned. The overall results suggest that the stable body weight normalization on a completely free diet does confer considerable psychological benefit on obese individuals. On the basis of the EDI results, post-BPD subjects were divided into weight-preoccupied and not-weight-preoccupied individuals. In the not-weight-preoccupied subjects, the psychosocial status and emotional rectivity were closely similar to those observed in lean control persons, whereas the few weight-preoccupied subjects, in spite of completely normal body weight, showed residual body dissatisfaction and personality traits very similar to those of eating-disordered patients.

Adolescent↗

PubMed1993

The use of bioelectrical impedance analysis for monitoring body composition changes during nutritional support.

Body composition was measured with bioelectric impedance analysis (BIA) in 30 patients with protein malnutrition following biliopancreatic diversion. Determinations were carried out prior to, during, and at the completion of intravenous nutritional support when the nutritional parameters had completely reverted to normal. Before treatment, body weight (BW), lean body mass (LBM), and body fat (BF) values were similar to those of controls, whereas the total body sodium/total body potassium (TBNa/TBK) and extracellular mass/body cell mass (ECM/BCM) ratios were considerably higher. During the support, no changes in BW, LBM, and BF were demonstrated, although a sharp decrease of TBNa/TBK and ECM/BCM was observed, thus demonstrating improved LBM composition. At the end of parenteral feeding, the BW, LBM, and BF values were similar to those observed before the support, while a further decrease in TBNa/TBK and ECM/BCM demonstrated a recovery towards normal of body composition. The full correspondence between clinical and BIA findings therefore suggests that this method may be valuable for monitoring body composition changes during nutritional support.

Adult↗

PubMed1993

A rapid method for site-specific mutagenesis using larger plasmids as templates.

To facilitate the introduction of specific point mutations in plasmids that are too large to be amplified efficiently by a single PCR, we have developed a method for site-directed mutagenesis by generating partial plasmid fragments, which introduces changes as simply as conventional techniques. Plasmids containing a fragment of the human immunodeficiency virus type-1 (HIV-1) envelope gene were subjected to PCR with four pairs of PCR primers for each desired point mutation. One primer in each of two of these four pairs contained the desired mutation. The four pairs of primers were designed so that four overlapping fragments were amplified from the plasmid template, two of which contained the mutation. These fragments were then reannealed and electroporated directly into Escherichia coli. The desired mutation was typically found in 66% to 83% of the resulting colonies. The technique is almost as simple as previous techniques, shows similar efficiency and is applicable to plasmids that would normally be too large for efficient site-specific mutagenesis. The entire procedure, from PCR amplification to transfection into E. coli, can be completed in one day.

Base Sequence↗

PubMed1993

[Eating behavior and energy expenditure].

The relationships between the resting energy expenditure (REE), measured by indirect calorimetry, and eating behavior, assessed by the "Three Factor Eating Questionnaire" were evaluated. The study was carried out in a group of healthy never-obese subjects and in two groups of formerly obese people, who have maintained a normal weight for more than two years. The subjects of the first formerly obese group had brought their body weight to normal by dieting. The second one comprised subjects following biliopancreatic diversion for obesity (BPD) in the long term, who maintain a normal weight because of the intestinal malabsorption due to the operation regardless of food consumption. In comparison with the other subjects, significantly higher cognitive restraint score values were observed in the post-diet subjects. Furthermore, a negative significant correlation between cognitive restraint and REE was found in the non operated subjects, while such correlation was not present in the BPD subjects. Therefore, in normal people cognitive restraint has to be considered to be related to behavioral-cognitive factors rather than biologically driven by energy requirements.

Adult↗

PubMed1991

Soluble interleukin-2 receptor decrease in the sera of HIV-infected patients treated with zidovudine.

Laboratory parameters which are modified following administration of zidovudine are becoming increasingly useful in monitoring the efficacy of treatment of early stages of HIV-1 infection. The serum levels of soluble interleukin (sILR)-2 receptor, which have been reported to increase early in HIV-1 infection, were found to be significantly lower in 24 patients being treated with zidovudine than in 69 patients who were not treated, 28 of whom had CD4+ counts greater than 400 x 10(6)/l, and 41 less than 400 x 10(6)/l, respectively (P less than 0.0001). A prospective study group of 33 subjects treated with zidovudine demonstrated a decrease in sIL-2R during therapy (base values 2113 +/- 1131 versus 1444 +/- 728 after 90 days of therapy; P less than 0.0007). The reduction of sIL-2R was greater in those subjects were p24 antigen became negative during treatment. sIL-2R therefore seems to be a useful tool in the monitoring of therapy with zidovudine.

CD4-Positive T-Lymphocytes↗

PubMedDate not supplied

The novel receptors that mediate the entry of herpes simplex viruses and animal alphaherpesviruses into cells.

An extended array of cell surface molecules serve as receptors for HSV entry into cells. In addition to the heparan sulphate glycosaminoglycans, which mediate the attachment of virion to cells, HSV requires an entry receptor. The repertoire of entry receptors into human cells includes molecules from three structurally unrelated molecular families. They are (i) HveA (herpesvirus entry mediator A), (ii) members of the nectin family, (iii) 3-O-sulphated heparan sulphate. The molecules have different attributes and play potentially different roles in HSV infection and spread to human tissues. All the human entry receptors interact physically with the virion envelope glycoprotein D (gD). (i) HveA is a member of the TNF-receptor family. It mediates entry of a restricted range of HSV strains. Its expression is restricted to few lineages (e.g. T-lymphocytes). (ii) The human nectin1alpha (HIgR), nectin1delta (PRR1-HveC), and the nectin2alpha (PRR2alpha-HveB) and nectin2delta (PRR2delta) belong to the immunoglobulin superfamily. They are homologues of the poliovirus receptor (CD155), with which they share the overall structure of the ectodomain. The human nectin1alpha-delta are broadly expressed in cell lines of different lineages, are expressed in human tissue targets of HSV infection, serve as receptors for all HSV-1 and HSV-2 strains tested and mediate entry not only of free virions, but also cell-to-cell spread of virus. (iii) The 3-O-sulphated heparan sulphate is expressed in some selected human cell lines (e.g. endothelial and mast cells) and human tissues, and mediates entry of HSV-1, but not HSV-2. The human nectin2alpha and nectin2delta serve as receptors for a narrow range of viruses. A characteristic of the human nectin1alpha-delta is the promiscuous species non-specific receptor activity towards the animal alphaherpesviruses, pseudorabies virus (PrV) and bovine herpesvirus 1 (BHV-1). By contrast with the human nectin1delta, its murine homologue (mNectin1delta) does not bind gD at detectable level, yet it mediates entry of HSV, as well as of PrV and BHV-1. This provides the first example of a mediator of HSV entry independent of a detectable interaction with gD.

Alphaherpesvirinae↗

PubMedDate not supplied

[Oral pathology in autologous bone marrow transplantation (ABMT). Its prevention and local treatment].

The level of chemo-radiotherapy that patients must undergo in the course of ABMT treatment causes a direct toxic mucous damage and serious medulla aplasia with subsequent neutropenia. Both factors significantly affect the appearance of oral complications. These represent one of the most frequent (congruent to 85%) postoperative problems. Particular attention must be paid to the conditions of the oral cavity during the phase immediately preceding the transplantation, owing to the fact that serious aplasia that patient show, may have potentially lethal consequences. Therefore, the authors of this study followed the patients during the pre-transplantation and post-transplantation phase, putting into practice a whole range of procedures whose aim is the prevention of oral lesions or the limitation of their seriousness and duration. The Hematology Department of San Martino Hospital admitted 30 patients, 22 with LNH and 8 with LLA, 10 men and 20 women. 10 patients represented the control group. The patients were visited approximately one month before the transplantation; they underwent x-ray examination and an objective examination of the oral cavity. On the basis of the results of these first examinations, each patient would be assigned to different therapeutic protocols so that all the patients would be surgically treated only when the state of the oral cavity was sufficiently good. Since admittance to hospital for ABMT, the patients were followed 3 times a week, then different protocols of prophylaxis and local therapy were applied, according to the presence of bacteriological, viral or fungal localized or diffused oral lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗