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Biomedical subjects

C Barrera

Publications and source records attributed to C Barrera.

25 records · Page 2Linked to original sources
PubMed1980

[Bacteriological evaluation of a procedure for disinfecting the Olympus GIF-D2 panendoscope].

We have performed a total of 107 cultures from three critical areas of an Olympus Panendoscope Model GIF-D2 in order to evaluate bacteriologically cur system of desinfection of this endoscope. Samples were taken from the distal end, external surface and biopsy canal before and after an endoscopic examination was performed. The procedure of desinfection employed was as follows: washing of the distal end, external surface and biopsy canal with Hexaclorophel (Phisohex) diluted 50% with water and a second washing with tap water. In the middle of the study, we added a second washing of the biopsy canal with ten ml. of ether alcohol to allow for better drying. As a result of the present study we observed that in the distal end in 50% of the samples we encountered bacteria. Cultures of the external surface were positive in 20% of samples. The biopsy canal should be washed with ether alcohol to allow for complete drying, because when we did not use this method, Pseudomonas Aeruginosa was isolated. After this modification we did not isolate bacteria. The most frequent types of isolated bacteria were from the normal oropharyngeal flora. From the present study we can conclude that desinfection of the Panendespe with Hexaclorophen gives satisfactory results on the external surface of the endoscope. Biopsy canal requires additional washing with ether alcohol. However, both procedures do not assure a satisfactory desinfection of the distal end.

Bacteriological Techniques↗
PubMed1976

A new model for antisperm autoimmunity in guine pigs.

Adult outbread male guinea pigs were autoimmunized without adjuvant. Homogenates were prepared with one of their own testes previously submitted "in vivo" and "in vitro" to thermal injury. Animals received a single or daily repeated intradermal injection without added adjuvant, in one or different skin sites. Guinea pigs daily sensitized in the same site during 30 days showed the presence of: a) dermal granuloma at the site of injection; b) several foci of typical allergic orchitis; c) delayed hypersensitivity detected by inhibition of macrophage migration; d) moderate titres of spermagglutinins and negligible levels of hemagglutinating antibodies. Guinea pigs receiving a single dose in one site only developed delayed hypersensitivity. Animals daily sensitized with the same dose of altered antigen in different sites, or with normal testis antigen either in one or different sites, showed negative results. The correlation among testicular lesion, dermal granuloma and cellular immunity is discussed. It is concluded that testis autosensitization is obtained in the absence of added adjuvant provided that a thermally injured gonad used as antigen is repeatedly injected in the same site.

Animals↗
PubMedDate not supplied

Leucocyte populations in semen and male accessory gland function: relationship with antisperm antibodies and seminal quality.

Semen samples from 279 infertility patients attending an Immunological Centre were analysed to evaluate the relationship between the populations of leucocytes, seminal quality, antisperm antibodies, and seminal vesicle function. The most frequent finding between leucocytospermic samples was asthenozoospermia (57%), whereas in non-leucocytospermic samples normozoospermia was the most frequent finding (47%). In the samples with asthenozoospermia, granulocytes predominated, whereas in those with oligozoospermia and azoospermia a reduction in the number of macrophages and lymphocytes was observed, suggesting an obstructive process at the level of epididymis and/or vas deferens where these leucocytes are mostly produced. In the case of hypofunction of the seminal vesicles there was a predominance in granulocytes. The increased levels of each type of leucocytes affected seminal quality only when seminal vesicles were affected. Only the elevated granulocytes count was related to a decrease in sperm motility. In those samples with leucocytospermia, positive antisperm antibodies (ASA) were associated with low sperm motility, low sperm normal morphology, and low value of seminal corrected fructose, whereas, in the absence of leucocytospermia, ASA, were more related to low sperm counts. These data suggest that granulocytes were more related to seminal vesicles dysfunction and sperm motility changes, and that ASA may be observed in the presence or absence of leucocytospermia.

Adult↗
PubMedDate not supplied

Evidence for hybridization by multilocus enzyme electrophoresis and random amplified polymorphic DNA between Leishmania braziliensis and Leishmania panamensis/guyanensis in Ecuador.

The taxonomic attribution of four Leishmania stocks isolated from humans in Ecuador has been explored by both multilocus enzyme electrophoresis and random amplified polymorphic DNA. For three loci, MLEE results showed patterns suggesting a heterozygous state for a diploid organism, while the corresponding homozygous states are characteristic of the Leishmania panamensis/guyanensis complex and Leishmania braziliensis, respectively. Other enzyme loci showed characters attributable to either the L. panamensis/ guyanensis complex or L. braziliensis. RAPD profiles exhibited for several primers a combination of the Leishmania panamensis/ guyanensis complex and L. braziliensis characters. These data hence suggest that the four stocks are the result of hybridization between L. panamensis/guyanensis and L. braziliensis. MLEE data show that the results cannot be attributed to either mixture of stocks, or an F1 in the framework of a simple Mendelian inheritance.

Animals↗