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Biomedical subjects

S Guida

Publications and source records attributed to S Guida.

13 recordsLinked to original sources
PubMed1992

Processing of interleukin-1 in cells of monocytic lineage is differentiation-dependent.

The interleukin-1 (IL-1) alpha and beta precursor proteins are processed and released from several cell types in the absence of a canonical signal peptide. To gain some insight into the mechanisms that allow the production of IL-1 alpha and beta, we have investigated by immunoprecipitation the synthesis, their release and processing in a promyeloblastic cell line of tumoral origin, U937, and in peripheral blood monocytes. We show that U937 monocytic cells, on induction with a tumor-promoting agent, synthesize and release into the culture medium proIL-1 beta but do not process it. Similarly, peripheral blood monocytes left in adherence for 24 h or longer, prior to addition of lipopolysaccharide, synthesize and release proIL-1 alpha and beta without detectable processing of either cytokine. Processing and release of IL-1 alpha and beta by peripheral blood monocytes can be observed when monocytes are left to adhere for periods less than 15 h before lipopolysaccharide addition. IL-1 alpha and beta show similar kinetics of release from the cells, suggesting the existence of a common mechanism regulating their secretion. Since peripheral blood monocytes left in adherence in the presence of lipopolysaccharide differentiate into macrophages, we conclude that release and processing of IL-1 can occur independently and that processing depends on the stage of differentiation of monocytes, i.e. only the monocytes at an early stage of differentiation produce 17-kDa IL-1 alpha and beta.

Cell Adhesion↗
PubMed1992

The chicken IL-1 receptor: differential evolution of the cytoplasmic and extracellular domains.

The evolutionary conservation of a sequence or part of it can help to identify the essential functional and structural domains within a protein. We have cloned and characterised a cDNA coding for the type-I interleukin-1 receptor (IL-1R) of chick (ch) embryo fibroblasts. The comparison of the amino acid (aa) sequences of the avian with that of murine (m) and human (h) IL-1Rs shows a 60% homology. The intracellular domain is the most conserved region of the chIL-1R, showing 76-79% homology to the murine and human sequences, respectively. The striking conservation of the cytoplasmic region of the receptor is confirmed by its homology with the Toll receptor protein of Drosophila melanogaster. The alignment between the chicken and D. melanogaster proteins shows the presence of four aa blocks with more than 80% homology. The possible functional significance of this homology is discussed. The extracellular binding region of the receptor has a clearly recognisable immunoglobulin-like structure although the sequence divergence is higher than in the cytoplasmic domain.

Amino Acid Sequence↗
PubMed1992

Chronicity rate of hepatitis B virus infection in the families of 60 hepatitis B surface antigen positive chronic carrier children: role of horizontal transmission.

It is known that the 5%-10% of adults infected with hepatitis B virus (HBV) develop a chronic infection and that HBV infection acquired at birth by an hepatitis B surface antigen (HBsAg)/hepatitis B "e" antigen (HBeAg)-positive mother almost invariably leads to chronic infection. Little information is, however, available about the risk of HBV infection acquired in childhood becoming chronic. We have, therefore, studied the chronicity rate of HBV infection in the families of 60 consecutive HBsAg-positive chronic carrier children. Of parents 81.5% and 78.6% of children showed serological evidence of past or ongoing HBV infection. The chronicity rate was significantly higher among children (73.4%) than parents (35.6%). Such a high chronicity rate in these children was not correlated with vertical transmission, since this was reported in only 1.7% of them. It is noteworthy that the chronicity rate of HBV infection was not significantly different between children of HBsAg-positive mothers and those in whom infection must have been horizontally transmitted because their mothers were HBsAg-negative. Although the families studied represent a selected sample and the role of genetic factors could not be excluded, our results seem to show that the most important factor in determining the outcome of infection is the acquisition of hepatitis B during childhood.

Adolescent↗
PubMed1992

Nutritional status and growth in children with chronic hepatitis B.

As reported for other chronic liver diseases, hepatitis B virus (HBV) chronic infection might result in malnutrition. In order to establish whether this disease could be responsible of malnutrition and hence influence growth, 75 children, chronically infected with HBV, have been followed up for 4 years. Thirty-one of them had chronic active hepatitis (CAH), 25 chronic persistent hepatitis (CPH), 14 chronic lobular hepatitis (CLH), and five cirrhosis (three active, two inactive). The nutritional status was evaluated every 12 months, with careful physical and laboratory examinations. General nutritional status was estimated according to Waterlow criteria (13, 14). At our first observation, 50 children were following a balanced diet with a caloric intake adequate for age and weight, whereas 25 were on a low-fat diet, begun in the belief of its therapeutic value. For seven patients of this second group, the caloric intake was below the daily requirement. The latter group showed a growth failure in weight when they were first seen at our center and gained weight when the dietary intake was normalized. However, no biochemical feature of malnutrition was observed in all the 75 children. At the end of the follow-up period, the nutritional status was satisfactory for all of them.

Alanine Transaminase↗
PubMed1992

Evaluation of two epoxy ether compounds for biocompatible potential.

Bovine arterial tissue exposed to two epoxy ether compounds (Denacol EX-313 and Denacol EX-810) was evaluated for its biocompatible potential by in vitro and in vivo test procedures. The battery of test procedures included percent Inhibition of Cell Growth, Medium Eluate Method (MEM), Agar Overlay (AO), Blood Compatibility, Acute Mouse Systemic Injection, Rabbit Intracutaneous Irritation, Rabbit Subcutaneous Implantation, Guinea Pig Maximization, and Ames Tests. The epoxy exposed tissue was found to be noncytotoxic, nonmutagenic, and biocompatible by the test methods employed. In addition, the maximum concentrations of the unreacted Denacol EX-313 and EX-810 solutions found to demonstrate noncytotoxic reactions by the MEM and AO procedures were identified as 55 and 60 ppm for the MEM and 150 and 200 ppm for the AO procedure, respectively. These studies suggest that Denacol EX-313 and EX-810 are acceptable solutions for the processing of implantable tissue provided the epoxy residuals remain below those levels found to be cytotoxic.

Animals↗
PubMed1991

T lymphocyte activation is associated with viral replication in chronic hepatitis B virus infection of childhood.

Activated circulating T lymphocytes expressing HLA-DR (mean +/- s.d. 11.0 +/- 5.2%) or interleukin-2 receptor (IL-2R) (2.1 +/- 1.7%) were significantly increased in 63 children with chronic hepatitis B virus (HBV) infection when compared with 33 age-matched healthy controls (3.0 +/- 1.3%, P less than 0.01, and 0.1 +/- 0.4%, P less than 0.01). HBeAg-positive patients had higher percentage of DR (11.9 +/- 5.1%) or IL-2R (2.4 +/- 1.7%) positive T lymphocytes than anti-HBe-positive children (7.4 +/- 3.6% and 1.1 +/- 1.5%, P less than 0.01 and P = 0.02 respectively). Similarly, HBV DNA-positive patients had higher percentage of DR (10.5 +/- 3.3) or IL-2R (3.2 +/- 1.7%) positive T cells than HBV DNA-negative children (6.6 +/- 2.8% and 1.2 +/- 1.5%, P less than 0.01 for both). There was a positive correlation between percentage of DR positive T lymphocytes and levels of HBV DNA. Sixty-two per cent of the DR-positive T lymphocytes were cytotoxic/suppressor and 35% helper/inducer. The relationship between viral replication and T lymphocyte activation is discussed.

Adolescent↗
PubMedDate not supplied

Is it possible to use the hypoosmotic swelling test as criteria for "freezeability" of human semen in an AID program?

The aim of this study was to determine the possibility of the introduction of another parameter--the hypoosmotic swelling test--in the evaluation of the freezing potentially of anonymous donor's semen sample to be utilized in an AID program. 154 donor semen samples were frozen using classic seminal parameters: HOS tests were performed but not utilized as criteria for freezeability. All specimens were thawed and another HOS test was performed. All specimens were divided into two groups on the basis of the pre freezing HOS test value--HOS tests positive (> or = 55%) and HOS test negative (< 55%)--to verify if it's possible to correlate this value to the recovery of a good motility after thawing. A further division was performed: HOS tests highly positive (> or = 70%), HOS positive (60-55%) and HOS tests negative (< 55%) but the authors did not find any statistical difference. As concerns the clinical evaluation, were considered the last 15 pregnancies achieved with 11 samples out of 22 utilized. There was not any statistical difference. The data could seem to confirm the hypothesis that it is not possible to utilize the HOS test as a predictive value of "freezeability" of human semen sample.

Cryopreservation↗
PubMedDate not supplied

Superovulation with buserelin and gonadotropins dramatically improves the success rate of intrauterine insemination with husband's washed semen.

The purpose of this study was to determine the effectiveness of intrauterine insemination with husband's washed semen during stimulated cycles using a combined treatment of GnRH agonist (buserelin) and gonadotropins. 47 infertile couples were studied; 25 couples were treated with buserelin and gonadotropins (study group) and 22 (control group) received clomiphene citrate alone. Indications for treatment, in both groups, were male subfertility, cervical factor or unexplained infertility. For sperm preparation, the same swim up technique in both groups was used. In the study group, 15 pregnancies were achieved (pregnancy rate: 60%) whereas only 5 pregnancies were achieved in the control group (pregnancy rate: 22.7%) (p less than 0.01). The pregnancy rate per cycle was 17.6 and 4.8 respectively (p less than 0.01). The mean number of follicles per cycle (+/- SEM) was 3.6 +/- 0.2 and 1.7 +/- 0.07, respectively (p less than 0.0005). Comparing successful and unsuccessful cycles a difference was observed only among the levels of 17 beta E2, both per cycle and per follicle/cycle (1075 +/- 165.4 vs 721 +/- 57.6 and 319.8 +/- 42.6 vs 219.9 +/- 17.8; p less than 0.01 and p less than 0.0005 respectively). The authors conclude that intrauterine insemination with washed sperm during stimulated superovulatory cycles is a successful mode of therapy in all couples with infertility not associated with anatomic damage of the adnexa or with chronic anovulation.

Adult↗