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Biomedical subjects

L Sinibaldi

Publications and source records attributed to L Sinibaldi.

At least 37 records · Page 2Linked to original sources
PubMed1987

Inhibition of BK virus haemagglutination by gangliosides.

The effect of gangliosides extracted from human group O Rh+ erythrocytes on haemagglutination by BK virus was investigated. Experiments were performed on both ganglioside mixtures and isolated fractions separated by column chromatography and characterized by thin-layer chromatography. These results were compared with those obtained with standard preparations of gangliosides, and the inhibiting activity was shown to be confined mainly to gangliosides with a RF lower than GM1. It was also observed that the insertion of gangliosides in liposomes increased the haemagglutination-inhibiting activity and that ganglioside coating restored the ability of glycosidase-treated human red blood cells to agglutinate.

BK Virus↗
PubMed1985

Gangliosides in early interactions between vesicular stomatitis virus and CER cells.

In the present report an attempt was made to elucidate the role of gangliosides in early interactions between vesicular stomatitis virus (VSV) and CER cells. Research was carried out to test the ability of gangliosides from mammal brains and from CER cells to inhibit viral attachment to susceptible cells. The incubation of VSV in the presence of gangliosides decreased the subsequent infection of CER cells by the virus. When similar experiments were performed with gangliosides inserted in liposomes the inhibition of infection was enhanced. Since carbohydrate moieties could participate to rhabdovirus binding as a part of a glycolipid receptor, CER cells were subjected to the action of glycosidases and these produced a fall in the viral attachment. Deglycosilated CER cells reacquired their susceptibility to virus infection after coating with gangliosides immediately after enzyme treatment. Results obtained show the participation of gangliosides in the receptorial structure for vesiculovirus of susceptible CER cells.

Animals↗
PubMed1984

Hereditary factor VII deficiency: report of a case of intracranial hemorrhage.

A case of factor VII deficiency in a 52-year-old woman who developed central nervous system hemorrhage is here reported. Screening coagulation tests were all normal except for prothrombin time, normotest and thrombotest. Specific assays of vitamin K-dependent factors revealed that factor VII activity was reduced (11 U/dl). The studies of the family demonstrated that 2 sisters out of 4 were heterozygous for the defect. The activity of factor VII in the offspring, classified as obligatory carriers, ranged between 62 and 78 U/dl, the antigen between 55 and 75 U/dl. The wide variability of factor VII in normal people and the possible compensative effect of normal alleles in carriers do not allow to define the variant, namely if the patient is a CRMR homozygote or a CRMR/CRM-double heterozygote.

Antigens↗
PubMed1982

Role of carbohydrates in cell membrane receptors for vesicular stomatitis virus.

A study has been made to clarify the importance of some carbohydrate components of goose red blood cell and BHK 21 cell membrane receptors for vesicular stomatitis virus (VSV). Experiments have been carried out by inducing enzymatic modifications on the surface of intact cells and following the interaction between VSV and treated cells. Results obtained indicate that the removal of mannose, galactose and fucose from cell membranes reduces the attachment of the virus to cell receptors.

Animals↗
PubMed1981

Receptors for BK virus on human erythrocytes.

The chemical nature of BK virus receptors on human erythrocytes was investigated. Glycosidases, KIO4, proteases, phospholipases and other substances acting specifically on different structures of plasma membranes were used to ascertain the role of surface cell components in the interaction with BK virus. The results obtained indicate an analogy between BK virus receptors on red cells and non-antibody serum inhibitors active against haemagglutination by the same virus.

BK Virus↗
PubMed1980

Capacity of staphylococci to grow in the presence of ovotransferrin or CrCl3 as a character of potential pathogenicity.

A total of 150 strains of staphylococci, clinically isolated, were tested for sensitivity to ovotransferrin (conalbumin). Among these, all the 50 coagulase-positive, mannitol-positive, and deoxyribonuclease-positive staphylococci appeared to be resistant to conalbumin, i.e., capable of growing in the presence of this transferrin. Among the other 100 strains, which were not classified as S. aureus, some appeared to be resistant and some were sensitive. The different behavior toward conalbumin is related to varying degrees of efficiency of the bacterial iron transport systems and, to test this, a simple method can be used, based on the addition of CrCl3 to the culture medium. The precipitation of iron produced by chromium salts has an effect on the growth of staphylococci similar to that produced by conalbumin and reveals the differences in the iron transport systems which occur in the genus Staphylococcus.

Biological Transport↗
PubMed1980

Separation by affinity chromatography of human very low and low density lipoproteins inhibiting Sindbis virus haemagglutination.

The haemagglutination-inhibiting activity of human serum towards Sindbis virus is linked to very low and low density lipoprotein classes, in particular to their lipid component. To investigate the specific role played in this inhibition by carbohydrates contained in the molecule, inhibitor separation was carried out by Concanavalin A-Sepharose affinity chromatography. A different behaviour among the inhibiting molecules in relation to the carbohydrate content was observed. The importance of mannose for the biological activity of the inhibitor is discussed.

Carbohydrates↗
PubMed1979

Different sensitivity of hemagglutinating and hemolytic activities of Sendai virus to non-antibody inhibitors.

Research was carried out in order to verify if some components of human serum, which are capable of inhibiting the hemagglutination by Sendai virus, are active even towards the hemolysis by the same virus. It was ascertained that both orosomucoid and low-density lipoproteins obtained by floatation had no action on the hemolysis by Sendai virus while lipoproteins precipitated with dextrane sulphate showed a certain inhibiting effect. This action however is not due to lipoproteins but is probably related to some substances used in the method of precipitation.

Antibodies, Viral↗
PubMed1978

[Studies of the possible importance of complement in increasing the hemagglutination-inhibiting activity of rabbit IgM against Sendai virus].

An investigation has been carried out in order to ascertain the effect of the presence of complement on the HI antibodies of the IgM class obtained in rabbit against Sendai virus. Contrary to the results obtained by some AA. with other viruses, in this case the presence of complement in the form of fresh guinea-pig serum has not modified the HI titre. It has however been demonstrated that in the guinea-pig serum an inhibitor is present, which is active towards Sendai virus and can be identified as a 19S alpha-globulin.

Animals↗
PubMedDate not supplied

Effect of natural and semisynthetic polymers on rabies virus infection in CER cells.

Different natural and semisynthetic polymeric carbohydrates inhibited rabies virus infection in chicken-embryo-related cells by interfering with the virus adsorption process; a dose-dependent relationship was exhibited. Among polysaccharides tested, the neutral polymer Scleroglucan and the negatively charged Keltrol, glyloid sulphate 4324, glyloid sulphate 4327 and alginic acid were the most effective and remained active at concentrations far below the cytotoxicity threshold. Data obtained indicated that the inhibition mechanism of polymers may be related to the ability of these compounds to bind to viral envelopes, although their interaction with cell surfaces cannot be excluded. The charge density and the polymeric backbone of the molecules seem to play a role in influencing the antiviral properties, whereas other features such as the sugar moieties do not appear to be relevant.

Adsorption↗
PubMedDate not supplied

[Cerebrovascular manifestations while taking combined estrogens and progestins for contraceptive purposes. Clinical cases].

This study concerns 20 patients with cerebrovascular disease in the course of oral contraception with estrogens/progestins. The assumption of oral contraceptives appears to be related to the cerebrovascular manifestations, which could be caused by alterations of the blood vessel walls or of the coagulative process induced by estrogens/progestins. The thrombogenic action of these substances could be enhanced by preexisting conditions such as protein C or protein S deficiency.

Adult↗