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I Martinez

Publications and source records attributed to I Martinez.

76 records · Page 5Linked to original sources
PubMedDate not supplied

Contribution to the laboratory diagnosis of human cryptosporidiosis.

Human cryptosporidiosis is an infection caused by Cryptosporidium spp, a coccidial protozoan of emergencial pathogenicity and responsible for severe and prostrating watery diarrhea, mainly in immunocompromised patients. Smears of stools submitted to concentration and staining by carbol fuchsin technique has been used in our laboratory as a diagnostic procedure for cryptosporidiosis. The long time observing the smears in the microscope due to the small size of the forms and the low contrast of the staining led us to introduce some modifications in the original protocol for the acid-fast staining. The smears were treated with the carbol fuchsin solution for 3 minutes as recommended by LENNETTE et al., 1985 and the solution of the ethyl alcohol 70%-chloride acid 0.5% was used instead of the ethyl alcohol-sulfuric acid 5% recommended by HENRIKSEN & POHLENZ, 1981. Smears were treated with the discoloration solution for 2 minutes. These modifications promoted a better washing out of the excess of carbol fuchsin therefore increasing the dye efficiency. In such conditions, the visualization of protozoan oocysts on the slides examined became easier. They were observed by the contrast of their intense pink-reddish pigmentation against the blue background. It's worthwhile to emphasize that these modifications offer advantages when time and accuracy are concerned.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Highly efficient eukaryotic gene expression vectors for peptide secretion.

Recently, we constructed a series of highly efficient universal eukaryotic gene expression vectors (Sheay et al., BioTechniques 15:856-862, 1993). Such vectors contain a viral promoter and enhancer followed by the adenovirus tripartite leader sequence, a multiple cloning site for the insertion of the gene of interest and a polyadenylation sequence. To enable expression of peptides to be secreted into the tissue culture medium or to be incorporated into the cell membrane, several modifications have been introduced into such vectors: stop codons in all three reading frames were inserted at the end of the multiple cloning site and a DNA sequence coding for a signal peptide for transport through the endoplasmatic reticulum (ER) was introduced downstream of the adenovirus tripartite leader sequence followed by two unique restriction enzyme recognition sites. A protocol is described that allows fast and easy cloning of peptide-coding regions, i.e., PCR products, for expression and secretion. The transport of a genetically engineered chimeric transmembrane protein connected to this ER leader sequence was as efficient as that of the original protein from which the ER sequence has been derived. These universal vectors can also be used for the easy construction of any chimeric transmembrane or secretion proteins.

Amino Acid Sequence↗
PubMedDate not supplied

Detection of HPV DNA by in situ hybridization in benign, premalignant and malignant lesions of the oral mucosa.

Evidence has accumulated in recent years that relates certain types of human papillomaviruses (HPV) to the development of some tumors. We use in situ hybridization to study DNA from HPV 6/11, 16/18 and 31/33/35 in 6 squamous papillomas, 18 hyperkeratotic/acanthosis lesions with and without dysplasia (5 and 13 cases respectively) and 27 squamous cell carcinomas of the oral mucosa. HPV DNA was found in 66% of squamous papillomas, 38.4% of hyperkeratotic/acanthosis lesions without dysplasia, 60% of epithelial dysplasia and 37% of squamous cell carcinomas. HPV DNA 6/11 was the most common type found, and in squamous cell carcinomas HPV DNA appear more frequently in well differentiated tumors.

Adult↗