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J I Paz

Publications and source records attributed to J I Paz.

17 recordsLinked to original sources
PubMed1997

Duodenal leishmaniasis diagnosed by biopsy in two HIV-positive patients.

We describe two cases of duodenal leishmaniasis in patients with human immunodeficiency virus (HIV) infection, diagnosed by light and electron microscopy. The patients presented nonspecific signs and symptoms, blood cultures were sterile, and serological tests for Leishmania spp. were negative. Endoscopy showed normal-appearing mucosa in one patient and possible peptic duodenitis in the other patient. In these patients, the parasite was only detected in a duodenal biopsy specimen. In view of the unusual location of the parasite and the fact that the diagnostic and dissemination of the disease was established by means of conventional biopsy, this is not a routine procedure for the diagnosis of leishmaniasis because the classic procedures require the demonstration of antibodies and visualization in bone marrow, lymph nodes, liver and/or spleen aspirates. We decided to report these two cases to call attention to the possible finding of Leishmania amastigotes in biopsies from intestinal mucosa in HIV infected patients.

Adult↗
PubMed1995

Pilomatrixoma: a description of two cases diagnosed by fine-needle aspiration.

The present work reports on the findings obtained by fine-needle aspiration of two pilomatrixomas located on the upper limbs whose diagnosis was confirmed histologically. In both cases, the cytology disclosed a proliferation of small round basaloid cells that were dispersed and grouped in clusters together with squamous cells and abundant multinucleate giant cells. The differential diagnosis with other neoplasms is discussed.

Adult↗
PubMed1995

Diagnosis of genital infection caused by human papillomavirus using in situ hybridisation: the importance of the size of the biopsy specimen.

AIM: To determine the size of a cervical biopsy specimen with human papillomavirus (HPV) infection required to enable in situ hybridisation to be carried out with a guarantee of a reliable result. METHODS: In situ hybridisation was carried out in 142 cervical uterine biopsy specimens classified histologically as low grade and high grade squamous intraepithelial lesions. Epithelial length at the level of the basal membrane was measured by image analysis. The specimens were divided into 10 groups based on epithelial length. RESULTS: Of the biopsy specimens, 61.2% were HPV positive. In specimens with an epithelial length below 5 mm 31.9% were HPV positive; in those between 5 and 9 mm in length 67.5% were HPV positive; and in those greater than 9 mm in length 81.8% were positive for HPV. For low grade squamous intraepithelial lesions (n = 90), 68.4% of specimens with an epithelial length greater than 5 mm were HPV positive. For high grade squamous intraepithelial lesions (n = 52), 86.8% of specimens with an epithelial length greater than 5 mm were HPV positive. CONCLUSIONS: For a diagnosis of HPV infection using in situ hybridisation, the minimum length of epithelium in a cervical biopsy specimen should be 5 mm. For high grade squamous intraepithelial lesions, specimens over 5 mm in length are suitable. For low grade squamous intraepithelial lesions, to minimise the number of false negative results, the ideal minimum length is 10 mm.

Biopsy↗
PubMed1993

Oat-cell carcinoma of primary location in the pericardium. A case report.

A case of oat-cell carcinoma arising in the pericardium of a 51-year-old woman is described. The patient had multiple nodes; the largest was 2 x 1 cm. Two years later the patient presented with a tumor on her lower gum; this measured 2 mm and had similar characteristics to the previous one. The immunohistochemical study showed strong positivity for neuron-specific enolase. From review of the literature, it may be concluded that this is the first report of oat-cell carcinoma occurring in the pericardium.

Carcinoma, Small Cell↗
PubMed1992

Statistical evaluation of the predictive power of fine needle aspiration (FNA) of salivary glands. Results and cytohistological correlation.

Fine needle aspiration (FNA) of the salivary glands was carried out on 97 patients. Diagnosis was confirmed by histological findings in 93 patients. There were 75 benign lesions (including 52 benign tumours) and 18 malignant lesions. In our series "positive predictive value" of FNA was 0.900 and the negative predictive value was 0.963. Thus, the probability of a false positive is 0.100 and of a false negative 0.037.

Biopsy, Needle↗
PubMed1992

Comparative study of in situ hybridization and immunohistochemical techniques for the detection of human papillomavirus in lesions of the uterine cervix.

Among the techniques currently used for the detection of human papillomavirus (HPV) in genital lesions, only two correlate HPV with the histopathological findings of the lesion: immunohistochemistry and in situ hybridization. Consequently, we were prompted to carry out a comparative study on both techniques to check their utility and efficacy as routine diagnostic methods. 52 biopsy specimens of uterine cervix diagnosed histopathologically as condylomas and cervical intraepithelial neoplasia+koilocytosis were studied by immunohistochemical and in situ hybridization techniques using a polyclonal antibody against the common antigen of the HPV capsid and three biotinylated DNA probes specific to HPV types 6/11, 16/18 and 31/35/51. Immunohistochemistry detected 21 positive cases (40.38%), whereas in situ hybridization detected 40 positive cases (76.92%); of the latter, 30 were positive for HPV types 6/11, 3 for HPV types 16/18 and 11 for HPV types 31/35/51. The results suggest that in situ hybridization is a more sensitive technique than immunohistochemistry. However, we recommend the use of both techniques in the case of potentially malignant lesions since better prognostic information can be obtained from joint analysis of both results.

Adolescent↗
PubMed1992

Study of infection by human papillomavirus in severe dysplasias and carcinomas in situ of the uterine cervix using immunohistochemistry and in situ hybridization.

Diagnosis of human papillomavirus (HPV) infection in uterine cervical lesions is usually based on histopathological criteria and, in some cases, is confirmed by immunohistochemistry. The recent development of in situ hybridization techniques has facilitated the detection of HPV in these lesions. Consequently, we carried out a study on 18 uterine cervical biopsy specimens histopathologically diagnosed as severe dysplasias and carcinomas in situ, using an immunohistochemical method with a rabbit polyclonal antibody against the HPV common structural antigen and in situ hybridization techniques with three biotinylated DNA probes for HPV types 6/11, 16/18, and 31/35/51. By immunohistochemistry only one case (5.5%) proved to be positive, whereas by in situ hybridization 12 HPV-positive cases were obtained (66.6%), of which 7 were positive for HPV types 16/18 (38.8%) and 6 for HPV types 31/35/51 (33.3%). One case was positive with positive with both DNA probes. From our results it can be inferred that in situ hybridization is a more sensitive technique than immunohistochemistry for confirming the presence of HPV in severe dysplasias and carcinomas in situ of the uterine cervix. Furthermore, in situ hybridization provides much more information than immunohistochemistry since it permits the identification of the HPV types causing the lesion.

DNA Probes↗
PubMed1991

Carcinosarcoma of the stomach with endocrine differentiation. A case report.

An unusual tumor was observed in a 67-year-old man. Microscopically, the tumor was composed of epithelial cells forming glands (CEA, EMA-positive) and spindle-shaped cells (vimentin-positive). A third component was a cell population ultrastructurally characterized by intracytoplasmic granules surrounded by a membrane; these proved to be chromogranin A-positive in the immunoperoxidase study.

Aged↗
PubMedDate not supplied

Immunohistochemical modifications of "B cells" in experimentally-induced pancreatic cancer--correlation with serum insulin values.

In pancreatic ductal adenocarcinoma induced in the Syrian hamster by N-nitrosobis (2-oxopropyl) amine (Bop) B cells persisted with focal dispersion in the tumor zone. The localization of these varied depending on whether the animals had initial or long standing tumors. In the animals with initial tumors, immunohistochemical techniques indicated the B cells formed part of the tumoral glands and/or were intimately related to the cells of the walls of the tumor glands or present in the stroma. Insulin values were high in these animals. In the longer-developed tumors, insulin levels tended to be lower and although B cells were seen forming part of the tumor glands, those in the tumoral stroma were predominant.

Animals↗
PubMedDate not supplied

Experimental pancreatic adenocarcinoma: an immunohistochemical study for CA 19-9 and its correlation with serum levels.

Experimental pancreatic carcinoma induced in Golden Syrian Hamsters by subcutaneous injections of N-nitrosobis-(2-oxopropyl) amine (BOP) was studied during the different phases of its development by determination of serum CA 19-9 levels and tissue labeling with CA 19-9 TM. Significant differences were observed in the CA 19-9 values between the controls and animals with carcinoma (p less than 0.01) and between the latter and animals with cystic or cystic papillary lesions (p less than 0.01). Distribution of the deposits of CA 19-9 TM was different in the initial tumoral lesions and in the longer-developed tumors. An important correlation was observed between tissue deposits and serum levels of this tumor marker.

Adenocarcinoma↗
PubMedDate not supplied

Usefulness of antral brushing samples stained with Diff-Quik in the cytologic diagnosis of Helicobacter pylori. A comparative methodologic study.

We studied the usefulness of antral cytologic specimens obtained by brushing and stained with Diff-Quik in the diagnosis of gastric colonization by Helicobacter pylori in 102 patients, comparing this method with other commonly employed techniques. We report on the sensitivity, specificity, predictive value for positive and negative cases of each of the techniques used, and diagnostic problems posed by each. In general, the Diff-Quik-stained samples proved to be the most useful. This technique is a simple, economical and practical method for the diagnosis of gastric colonization by H pylori.

Biopsy↗