Biomedical subjects

R Pelayo

Publications and source records attributed to R Pelayo.

24 records · Page 2Linked to original sources

PubMed1990

[Immunochemical differences in the surface polysaccharides obtained from Entamoeba histolytica strain HM1:IMSS and its virulent (C-A) and non-virulent (L-6) clones].

There probably exist many different surface molecular polysaccharides with different compositions of their constituent sugars, in the different zymodemes. This fact might have a repercussion upon the resistance to the lysis of the complement. Seeking to prove this hypothesis, the ideal would be to obtain polysaccharide molecules of type LPFG of pathogenic and non-pathogenic zymodemes, demonstrating that there is a difference in the chemical composition of their polysaccharides. If this were true, a serologic classification, of the different zymodemes, would be possible in a fashion similar to gram-negative bacteria. Our results suggest the existence of structural differences between the polysaccharides of a virulent clone (C-A) and a non-virulent one (L-6).

Animals↗

PubMedDate not supplied

Pediatric sleep-related breathing disorders.

Sleep-related breathing disorders (SRBD) can occur at any age. Obstructive sleep apnea, upper airway resistance syndrome and obstructive hypopnea syndrome all lie on the pathological continuum of SRBD. These disorders can have a great impact on a child's quality of life and can progress to significant complications. The symptoms, signs, work-up, and treatment of SRBD in children are discussed.

Age of Onset↗

PubMedDate not supplied

Narcolepsy in children: a practical guide to its diagnosis, treatment and follow-up.

Narcolepsy is a neurological syndrome characterised by daytime somnolence and cataplexy which often begins in childhood. Failing to recognise the condition may lead to mislabelling a child as lazy or depressed. The diagnostic criteria for narcolepsy vary with age. In children 8 years and older a Multiple Sleep Latency Test with an average latency of less than 8 minutes, and 2 or more sleep onset REM episodes supports the diagnosis. Human leucocyte antigen (HLA) marker DQbeta1 -0602 has been associated with narcolepsy. The current evidence supports the hypothesis that transmission of narcolepsy is multifactorial. with at least two genes, one of which is non-HLA related. The goal of all therapeutic approaches in narcolepsy is to control the narcoleptic symptoms and allow the patient to continue to fully participate in personal and academic activities. This usually requires a combination of behavioural therapy along with medication. Medications for patients with excessive sleepiness are usually stimulants, including amphetamines. However, a novel wake promoting agent, modafinil, is now available. Cataplexy can be controlled by medications with noradrenergic reuptake-blocking properties, such as clomipramine and fluoxetine, through their active metabolites. Increased awareness of narcolepsy is important to allow earlier diagnosis. Research on the effects different medications have, specifically on children with narcolepsy, has been very limited.

Child↗

PubMedDate not supplied

[Factors of Salmonella typhi virulence in relation to the development of new vaccines].

Although many vaccines against typhoid fever have been developed, none have been adapted for their further application on developing countries. In order to get better vaccines, the virulence factors of both S. typhi and S. typhimurium have been studied. Thus, some protection assays have been made using surface antigens involved on virulence or using live attenuated vaccines of bacteria mutated on virulence genes. Here we present a brief review about virulence factors studied so far for the development of new vaccines.

Adolescent↗

PubMedDate not supplied

[Monoclonal antibodies against the lipopolysaccharide of Salmonella typhi 9,12,VI:d. Analysis of passive protection in a mouse model of typhoid fever].

The current work was undertaken in order to assess the role of the monoclonal antibodies (Mabs) to lipopolysaccharide (LPS) of Salmonella typhi in the induction of passive protection against the challenge with the bacteria in a mice model. BALB/c mice were immunized with the whole bacteria, mice with high anti-LPS antibody titers were killed, the spleens were removed and splenocytes were fused with the mouse plasmocytoma SP2/0. Two IgM monoclonal antibodies against porins were developed. Each one of these Mabs recognized the polysaccharide region of LPS. Passive immunization with supernatant fluid of mice with one of these monoclonal antibodies did not protect against challenged with 20 LD50 and 100 LD50 of Salmonella typhi. The results suggest that LPS is not valuable immunogen for the induction of a protective status against typhoid fever.

Animals↗

PubMedDate not supplied

[Elaboration of an immunosorbent for the purification of porins from Salmonella typhi 9, 12, Vi:d].

The current work was undertaken to purify porins of Salmonella typhi, which are outer membrane proteins (OMPs) that induce protection in mice against challenge with the bacteria in mucin. OMPs, isolated with a non-ionic detergent, had a 4% contamination with LPS (endotoxin) and molecular sizes ranging from 17 to 70 KDa. Porins (Mw 38-41 KDa) were isolated from OMPs preparative SDS-PAGE. Anti-porins antisera were raised in rabbits and specific IgG was purified, which was coupled to Sepharose-CNBr. This immunosorbent was used to purify LPS-free porins.

Antibodies, Bacterial↗