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Biomedical subjects

E L Franco

Publications and source records attributed to E L Franco.

85 records · Page 5Linked to original sources
PubMed1981

Reverse enzyme immunoassay for detection of specific anti-Toxoplasma immunoglobulin M antibodies.

A reverse enzyme immunoassay (R-EIA) is described, in which polystyrene muplates are sensitized with anti-immunoglobulin M (IgM) (mu chain) antibodies and then sequentially allowed to react with patient's serum, peroxidase-labeled Toxoplasma gondii soluble antigen, and substrate. Measurement of activity of the solid-phase bound enzyme conjugate was done by colorimetric reading of the final developed color and kinetically by the initial rate of color development. This R-EIA allowed full resolution between absorbance values of a group of 36 sera which presented positive results in the Toxoplasma IgM immunofluorescence test and the remaining groups, which consisted of 39 normal individuals, 22 rheumatoid factor-positive sera, 8 Waldenstrom's macroglobulinemic sera, 3 infectious mononucleosis samples, and 6 high-titered IgG anti-T. gondii sera. No interference of rheumatoid factor IgM or inhibition by high-titered specific IgG was detected, even in the false IgM immunofluorescence-positive rheumatoid factor samples. Likewise, false-negative IgM immunofluorescence samples gave positive R-EIA even without adsorption with Staphylococcus aureus protein A. The possibility of direct tagging of the antigen with the enzyme eliminates the need for using antigen and anti-antigen conjugates as separate layers, therefore eliminating one step in the assay.

Animals↗
PubMed1980

Immunoglobulin G and immunoglobulin M polar staining of Toxoplasma gondii in the indirect immunofluorescence test.

Polar staining (PS) of Toxoplasma gondii in the indirect immunofluorescence test has been considered a nonspecific reaction caused exclusively by certain immunoglobulin M (IgM) antibodies and confined to the anterior end of the parasite. After we observed a patient with positive serology for Chagas' disease who presented an IgG PS reaction, we studied sera from 120 patients with Chagas' disease, 20 sera from patients with Leishmania donovani infection, and 30 sera from patients with Leishmania braziliensis infection. When only those specimens having no detectable anti-Toxoplasma activity were considered, a significantly (P less than 0.01) higher prevalence of IgG PS was found in the Chagas' disease and L. donovani groups than in sera from normal American and Brazilian adults. Those sera also showed higher PS titers (1:64 to 1:1,024) when compared with controls (1:16 to 1:64). IgG PS titers did not decrease after serum treatment with 2-mercaptoethanol. However, the same treatment removed completely IgM PS. IgG PS, but not IgM PS, could be removed by adsorption with Trypanosoma cruzi epimastigotes. IgM PS was found in all samples studied, except in 41 of a group of 43 umbilical cord sera. It was found that the antigen source and the microscopy system can influence the detection of PS. It is proposed that after finding an intense IgG PS reaction, the laboratory should screen such serum also for anti-T. cruzi antibodies which may be undetected in the sample.

Adult↗
PubMedDate not supplied

Microcomputer-assisted univariate survival data analysis using Kaplan-Meier life table estimators.

We describe a microcomputer program (KMSURV) for exploratory univariate statistical analysis of survival data which is directly applicable to the evaluation of clinical trials and to retrospective epidemiological studies of hospital registry-based data. The program calculates life-table-like information based on Kaplan-Meier's product-limit estimators of the survivorship function S(t) and provides summary measures of average survival times. In addition, two non-parametric tests for the comparison of survival distributions are performed. A report-quality, high resolution plot of the S(t) estimates for all groups being compared complements each set of analyses. KMSURV is not a simple adaptation of a mainframe statistical analysis package and, thus, it utilizes efficiently the interactive environment which is inherent in microcomputing.

Actuarial Analysis↗
PubMedDate not supplied

Viral etiology of cervical cancer: a critique of the evidence.

Cancer of the uterine cervix is one of the most common malignant diseases worldwide. Although morbidity rates have declined in the past several decades as a consequence of wide-scale screening, the disease remains an important public health problem. The risk of cervical cancer is strongly influenced by sexual behavior, which suggests a causal role for an infectious agent. Certain types of human papillomaviruses (HPVs) seem to be involved in the genesis of the disease. In addition, there is good evidence that herpes simplex viruses may also be implicated. Recently, important epidemiological incoherences have been found with respect to the sexual transmission route of HPV infection in the causal pathway of cervical cancer. HPV infection rates in asymptomatic women do not seem to be related to sexual behavior, and if analyzed simultaneously sexual behavior and HPV infection seem to be independent predictors of cervical cancer risk. If confirmed by further research, these findings could signify that there may be alternative etiologic mechanisms for cervical cancer. Since some researchers have recently proposed public health action because of the acceptance of HPV infection as a necessary cause of cervical cancer, it is imperative that the aforementioned incoherences be immediately resolved by further research.

Female↗
PubMedDate not supplied

Preoperative irradiation therapy and radical hysterectomy: prognostic value of tumor regression after initial irradiation of squamous cell carcinoma of the cervix.

OBJECTIVE: To investigate the role of tumor persistence in patients submitted to irradiation therapy and radical hysterectomy. DESIGN: A retrospective analysis of prognostic factors. LOCATION: Hospital A.C. Camargo, São Paulo, Brazil, a private non-profitmaking foundation and tertiary referral centre. PATIENTS: A total of 629 cases of invasive squamous cell carcinoma of the cervix were studied. Criteria for inclusion in the study were: confirmed histological diagnosis of squamous cell carcinoma and no previous treatment (except for preoperative radiotherapy carried out at the Hospital A.C. Camargo itself). At the end of the follow-up period, 410 patients (65%) had no evidence of disease and 219 (34.8%) had died because of the tumor. INTERVENTION: The patients were submitted to radical surgery and radiation therapy, separately or in combination between 1953 and 1982. MAIN OUTCOMES MEASURES: Multivariate analysis of the different variables was performed according to the Cox regression method. RESULTS: The variables of prognostic value were, in decreasing order of importance: the decade of patient admission (p = 0.0001), the modality of therapy employed (p = 0.0005), the presence of residual tumor in the surgical specimens (p = 0.0055) and the clinical stage of the disease (p = 0.0575). CONCLUSION: Radiation therapy controlled a considerable number of local tumors and pelvic lymph nodes but not all of them in every patient. There is a specific group of patients for whom radical surgery is necessary to achieve control of the disease.

Brachytherapy↗
PubMedDate not supplied

Prognostic value of human papillomavirus in the survival of cervical cancer patients: an overview of the evidence.

Some studies have suggested that the presence in tumors of nucleic acids from human papillomavirus (HPV) constitutes a prognostic marker of disease severity in cervical cancer. There are two conflicting lines of evidence in this regard. First, the presence of HPV 18 is equated to rapid progression through early disease stages, possibly resulting in a more aggressive clinical course. Although fragmentary, in terms of the clinical and epidemiological basis, this line of evidence has some experimental support. Second, the absence of HPV from the tumor would confer a worse prognosis than if any viral types were present. Unlike the former, the latter line of evidence is not bolstered by experimental data but emerged from persuasive clinical studies, which had adequate sample sizes, used survival end points, and controlled for confounders. The absence of HPV in some tumors could indicate that they originated through different oncogenic mechanisms, perhaps resulting in different cell proliferation rates and, consequently, distinct clinical behavior. On the other hand, HPV detectability could simply be a correlate of other genuine prognostic characteristics, which would explain its association with survival. Both the nature and the mechanism of the prognostic role for HPV in cervical cancer remain to be elucidated. The paucity of studies can be attributed to the labor-intensive nature of assays for HPV. It is hoped that the advent of the polymerase chain reaction method will facilitate the conduct of retrospective studies of archival histopathology specimens and survival information.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMedDate not supplied

Steroid hormone receptors in male breast diseases.

Estrogen (ER), progesterone (PR), glucocorticoid (GR) and androgen (AR) receptors were assayed in tumor samples from 8 cases of male breast cancer (MBC) and 20 cases of male gynecomastia. Seven out of eight (87.5%) male tumor samples had positive ER assays with values ranging from 12 to 180 fmol/mg protein. Of the seven ER positive cases of MBC, six, had positive PR activity with high titers. Positive GR and AR values were also detected in 75% of MBC cases. Concentrations of all four receptors were significantly correlated with each other. With gynecomastic tissue, the proportion of receptor-positive patients was 20% ER, 20% PR, 20% AR, and 45% GR. Except for GR, steroid receptor values for MBC individuals were significantly higher than those of gynecomastia patients.

Aged↗
PubMedDate not supplied

Prognostic factors and relative risk in hypopharyngeal cancer--related parameters concerning stage, therapeutics and evolution.

The prognostic value of 16 parameters was evaluated in a series of 126 squamous cell carcinoma of hypopharynx between 1978 and 1985 at the "Serviço de Cirurgia de Cabeça e Pescoço" of the "Hospital Heliópolis", São Paulo. The variables considered were: age, sex, ethnic background, interval between diagnosis and detection of first symptom, extension of primary lesion (T), N categories, histologic evaluation of primary lesion (pT) and neck node metastasis (pN), number of clinical positive nodes (NGPOS), radiation, chemotherapy and recurrence of the disease (local, regional and distant metastasis). After a multifactorial study using Cox life table model (3) and Dixon mathematic-statistical model (8), 5 of those 16 parameters were found to influence survival, independently. The five variables organized according to hypopharynx cancer prognostic significance were: age, odynophagia, number of clinical (NGPRE) and histological (NGPOS) metastatic lymph nodes and radiation therapy; odynophagia and radiotherapy were the variables that decreased the relative risk of recurrence in the survival of cancer of the hypopharynx.

Adult↗
PubMedDate not supplied

Determinants of AIDS preventive behaviour among dental professionals.

This study was conducted to assess concerns regarding AIDS and to identify determinants of poor preventive behaviour among dentists. Questionnaires were distributed to a random sample of 342 professionals. Respondents showed the lowest knowledge scores on topics dealing with symptoms, epidemiology and AIDS control. The predictors of poor AIDS knowledge were: more than ten years of practice and a strong belief to be professionally susceptible to HIV infection. Sterilization of high speed drills was disappointing; only 14.2% of dentists reported using heat sterilization. Predictors of poor preventive behaviour were: poor ability in clinical AIDS identification, more than ten years of practice and poor knowledge of AIDS prevention and control. Dental burs were the major cause of occupational injury. Professionals who recap needles are three times more likely to sustain needlesticks than those who do not. Our results suggest the need to increase AIDS knowledge and to improve compliance to infection control measures among dentists.

Acquired Immunodeficiency Syndrome↗