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E Silva

Publications and source records attributed to E Silva.

At least 91 records · Page 5Linked to original sources
PubMed1996

Malignant transformation in endometriosis of the urinary bladder: case report of clear cell adenocarcinoma.

Clear cell adenocarcinoma of the urinary bladder is a very rare neoplasm. This mullerian tumor frequently arises from ovarian endometriosis. We present a case of clear cell adenocarcinoma arising from endometriosis in the bladder; this is only the third such case report in the English language literature. Endometriosis involves the bladder in only approximately 1% of patients with this disease. The patient is a 40 year-old woman who has a history of adenocarcinoma arising from endometrial tissue in the bladder. Her tumor invaded the rectum, necessitating an anterior resection of the rectum as well as a partial cystectomy and a right oophorectomy. This case confirms that the relationship between endometriosis and clear cell adenocarcinomas of the female genital tract extends to the urinary bladder. Carboplatin chemotherapy was initiated in this patient.

Adenocarcinoma, Clear Cell↗
PubMed1996

Unusual presentation of a metastatic choriocarcinoma following a full term pregnancy: a case report.

Choriocarcinoma most commonly follows a molar pregnancy, but it may develop after any gestational event. If choriocarcinoma follows a term pregnancy, it is associated with an unfavorable outcome and a 60% survival rate. A 33 year female who had delivered a normal girl 4 months before, presented with a nodule on the scalp behind the right ear. The pathologic diagnosis was compatible with metastatic choriocarcinoma. This tumor did not respond to chemotherapy, and she died a year later of multiple liver and pulmonary metastases. The development of a choriocarcinoma following a full term pregnancy is associated with a poor prognosis. We suggest that patients who do not achieve a clinical or serological remission after EMA-CO treatment be considered for high dose chemotherapy such as transplant.

Adult↗
PubMed1996

[Purification of the natural 24kd (P24) of the type-1 human immunodeficiency virus (HIV-1) using immunoaffinity].

The use of systems to detect the presence of 24kd protein as well as the levels of antibodies to it, is very useful in the follow-up of HIV-1 infected individuals. To develop these systems it is necessary to have this protein purified. The present paper describes the purification of p24 starting from the semipurified viral flattening on saocaharose gradient, using immunoaffinity chromatography with monoclonal antibodies coupled to Sepharosa 4B activated with cyanogen bromide. For the characterization of the purified product it was used polyacrylamide gel electrophoresis with silver staining and immunoelectrotransference. As a result, it was obtained p24 which can be used for the development of diagnostic tools and monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1995

Visible light anaerobic photoconversion of tyrosine sensitized by riboflavin. Cytotoxicity on mouse tumoral cells.

The anaerobic phototransformation of tyrosine under visible light sensitized by riboflavin is reported. The cytotoxicity of the anaerobic photoproducts on in vitro-cultured myeloid mouse tumoral cells was demonstrated. A radical mechanism is proposed. Dityrosine was identified as one of the main anaerobic photoproducts by using absorption, emission and 1H-NMR spectra.

Aerobiosis↗
PubMed1995

Concurrence of Clostridium difficile toxin A enzyme-linked immunosorbent assay, fecal lactoferrin assay, and clinical criteria with C. difficile cytotoxin titer in two patient cohorts.

The accurate and sensitive diagnosis of Clostridium difficile-related diarrhea, normally treated with vancomycin, has become increasingly important in light of the emergence of dangerous new strains of vancomycin-resistant enterococci. In order to improve the threshold for C. difficile diagnosis and treatment, a number of commonly used assays for the diagnosis of C. difficile diarrhea were examined. These included an enzyme-linked immunosorbent assay for C. difficile toxin A (ToxA), a CHO cell culture assay for fecal C. difficile (cyto)toxin B, and a lactoferrin latex agglutination assay for fecal lactoferrin (LFLA). We studied 722 fecal specimens submitted by physicians for C. difficile toxin testing at the Salem, Va., Veterans' Affairs Hospital and at the University of Virginia Medical Center in Charlottesville. Charts were reviewed from 123 Veterans' Hospital patients and 114 University of Virginia patients for clinical criteria indicative of C. difficile diarrhea. An increasing titer of CHO cell cytotoxicity was correlated with an increasing likelihood of ToxA positivity (5 to 90%), LFLA positivity (39 to 77%), and clinical agreement (28 to 85%). However, some data indicate that the CHO cell cytotoxicity assay may be nonspecific when positive only at low titers. When the CHO assay result is positive at high titers, it remains the best diagnostic tool. Yet, when it is positive at a low titer, careful interpretation of the results in conjunction with other assays and the clinical setting is warranted, especially in light of new drug-resistant strains of microorganisms.

Animals↗
PubMed1995

Peritoneal papillary serous carcinoma: response to Taxol in platinum resistant disease.

A case of peritoneal papillary serous carcinoma which developed after total abdominal hysterectomy and bilateral salpingo-oophorectomy for a benign condition is presented. The patient was treated with platinum-based chemotherapy to which she initially responded, but then the tumor progressed. High dose paclitaxel (250 mg/m2) was given. The patient tolerated this treatment well, achieving a rapid partial response with good palliation of symptoms. Paclitaxel should be considered for patients with a platinum resistant peritoneal papillary serous carcinoma.

Carboplatin↗
PubMed1994

In vivo diagnosis of cervical intraepithelial neoplasia using 337-nm-excited laser-induced fluorescence.

Laser-induced fluorescence at 337-nm excitation was used in vivo to differentiate neoplastic [cervical intraepithelial neoplasia (CIN)], nonneoplastic abnormal (inflammation and human papilloma viral infection), and normal cervical tissues. A colposcope (low-magnification microscope used to view the cervix with reflected light) was used to identify 66 normal and 49 abnormal (5 inflammation, 21 human papilloma virus infection, and 23 CIN) sites on the cervix in 28 patients. These sites were then interrogated spectroscopically. A two-stage algorithm was developed to diagnose CIN. The first stage differentiated histologically abnormal tissues from colposcopically normal tissues with a sensitivity, specificity, and positive predictive value of 92%, 90%, and 88%, respectively. The second stage differentiated preneoplastic and neoplastic tissues from nonneoplastic abnormal tissues with a sensitivity, specificity, and positive predictive value of 87%, 73%, and 74%, respectively. Spectroscopic differences were consistent with a decrease in the absolute contribution of collagen fluorescence, an increase in the absolute contribution of oxyhemoglobin attenuation, and an increase in the relative contribution of reduced nicotinamide dinucleotide phosphate [NAD(P)H] fluorescence as tissue progresses from normal to abnormal in the same patient. These results suggest that in vivo fluorescence spectroscopy of the cervix can be used to diagnose CIN at colposcopy.

Cervix Uteri↗
PubMed1994

Community prevalence of hepatitis C viraemia: a polymerase chain reaction study.

In order to estimate the prevalence of HCV carriage in an inner city health district, we undertook a polymerase chain reaction (PCR) based survey of sera collected from 1,0002 patients attending general practitioners for reasons unrelated to liver disease. The series comprised 305 sample selected sera patients sample from sera 995 patients previously screened by C100 antigen-based anti-HCV tests. Overall, 7 patients were positive for HCV RNA. Four cases had anti-C100 antibodies to HCV, 2 were strictly negative but had high-normal/borderline optical densities by ELISA assay, while one was completely anti-HCV negative. All but one had normal liver function tests. Only 3/7 PCR positive cases had any serum marker for hepatitis B (HBV) exposure (2 HBsAg positive, 1 IgM anti-HBc positive). The minimum point prevalence of HCV carriage in this community is 0.7%, approximating the HBsAg carriage in the same population (1%). HCV carriage in this inner city population is considerably higher than would be predicted by blood donor surveys. A positive anti-HCV anti-body (anti-C100) test is poorly predictive (approximately 10%) of HCV RNA carriage in a general practice based population in which measurement of "surrogate" (HBV related) HCV markers would have detected only 3/7 cases of presumed chronic HCV carriage.

Adult↗
PubMed1994

Fluorescence spectroscopy: a diagnostic tool for cervical intraepithelial neoplasia (CIN).

A spectroscopic system incorporating a pulsed nitrogen laser, an optical fiber probe, and an optical multichannel analyzer was utilized to record fluorescence spectra of the intact cervix at colposcopy. Spectra were obtained from 66 colposcopically normal areas and 49 histologically abnormal areas (5 pathologic inflammation, 21 HPV infection, 9 CIN I, 10 CIN II, and 4 CIN III) in 28 patients. The resulting spectra could be used to differentiate histologically abnormal tissues from colposcopically normal tissues with a sensitivity, specificity, and positive predictive value of 92, 90, and 88%. Furthermore, CIN could be differentiated from nonneoplastic abnormal tissues with a sensitivity, specificity, and positive predictive value of 87, 73, and 74%. These results suggest that laser-induced fluorescence can be used in the recognition and differential diagnosis of CIN at colposcopy.

Algorithms↗
PubMed1994

Nucleolar organizer regions: a potential prognostic factor in adenocarcinoma of the endometrium.

Nucleolar organizer regions, which are evaluated using a silver stain for paraffin-embedded sections (AgNOR), can be used as a measurement of cellular proliferative activity. In the endometrium significant differences have been seen between benign and malignant lesions. To determine if AgNOR counts are of prognostic value in endometrial cancer, we examined 28 patients who developed recurrent disease after surgical stage Ib and Ic endometrial cancer and compared this group with a matched control group of patients who did not develop recurrence. The mean AgNOR number per cell was significantly higher in patients with recurrent disease (P = 0.001). Only five of these patients had values less than 4, whereas only three of the control group had values higher than 4. There was also a significant difference in the percentage of cells with more than 5 and more than 8 AgNORs (P = 0.001). After radiation therapy, the number of AgNORs per cell decreased. Recurrent tumors had higher AgNOR counts than the respective primary tumors. In conclusion, patients at increased risk for recurrent endometrial cancer can be identified by high AgNOR counts. Further evaluation of this parameter and comparison to other prognostic factors seems warranted.

Adenocarcinoma↗
PubMed1994

Riboflavin-sensitized photoprocesses of tryptophan.

The photodegradation of tryptophan in oxygen saturated aqueous solution sensitized by riboflavin is accompanied by the generation of the following reactive oxygen species: 1O2, OH., H2O2 and O2.-. When parallel photodegradation experiments are run with 14C-riboflavin in one case and 14C-tryptophan in the other and the irradiation products are separated by Sephadex G-15 and C18-HPLC, the generation of the following species is detected: aggregate forms of riboflavin, indolic products associated to flavins, indolic products of molecular weight higher than tryptophan, formylkynurenine, and other tryptophan photodecomposition products. The significance of the riboflavin anion radical and tryptophan cation radical as intermediates in the photoproduct formation is discussed.

Catalase↗
PubMed1994

Visible light effects on tumoral cells in a culture medium enriched with tryptophan and riboflavin.

When NSO/2 myeloid cell line and teratocarcinoma F9 cells were irradiated in Dulbecco's modified Eagle medium enriched with tryptophan and riboflavin, toxic photoproducts for these tumoral cells were generated. The active participation of 1O2 and .OH was established using specific scavengers and quenchers. A cytotoxic effect was also observed when unirradiated tumoral cells were incubated in a previously irradiated culture medium enriched with tryptophan and riboflavin. When irradiated medium was used alone, enriched only with tryptophan or only with riboflavin, no toxic effect was observed. The relevance of charge transfer processes between triplet riboflavin and tryptophan in the generation of cytotoxic photoproducts is discussed.

Animals↗