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L Fonseca

Publications and source records attributed to L Fonseca.

49 records · Page 3Linked to original sources
PubMed1989

Postcensal estimates of household income distributions.

This article develops and evaluates a method for deriving postcensal estimates of household income distributions for counties. A modified lognormal probability curve is used as a model of income distribution. The function is closely related to the classical lognormal model, but it contains a nonlinear component in its derivation. Simulated postcensal estimates of household income distributions are compared with 1980 census data for the counties in California. The results indicate that the modified lognormal curve approximates observed income distributions well and produces reliable postcensal estimates for areas with a wide variety of median income levels and numbers of households.

Family↗
PubMed1983

Differential diagnosis between amoebic liver abscess and acute cholecystitis.

The Research Committee of the World Organization of Gastroenterology has gather information regarding the etiology of acute abdominal pain. Seven diseases cover 96% of the causes of this syndrome in many countries of the world, but some geographical variations have been observed. One example of these variations is amoebic liver abscess, present in 5 to 10% of Mexico City patients. Right upper quadrant pain is often present in amoebic liver abscess and acute cholecystitis. Thus, differential diagnosis of these two entities is difficult. Using discriminant analysis and "stepwise" procedures in 100 cases with cholecystitis and a similar number of patients with amoebic liver abscess, we found six variables (symptoms and signs with a significant chi square to distinguish between these two diseases. The symptoms and signs chosen were hepatomegaly, Murphy's sign, duration of pain greater than or equal to 48 hours, previous history of abdominal pain, dysentery, and facial pallor. These variables proved to be better than laboratory test results. With five of these variables it was possible to obtain an accuracy of 92%. Using six variables, if cases of tie (three variables present and three absent) were excluded, accuracy rose to 96%.

Abdomen, Acute↗
PubMedDate not supplied

The importance of sensitive detection of malaria parasites in the human and insect hosts in epidemiological studies, as shown by the analysis of field samples from Guinea Bissau.

A method based on the polymerase chain reaction (PCR) for highly sensitive detection and identification of human malaria parasites was applied to blood and mosquito samples obtained from a village in Guinea Bissau. The prevalence of parasites in the human population was shown to be greatly underestimated by microscopical examination. In particular, a high incidence of Plasmodium malariae and P. ovale parasites was revealed only by the PCR assay. Preliminary evidence was obtained to show that the distribution of P. malariae infections within the village was non-random. This was supported by analysis of the parasite species infecting the mosquito vector. The implication of these results for the design and interpretation of epidemiological surveys is discussed.

Animals↗
PubMedDate not supplied

Stromal distribution of CA 19-9 as a predictor of lymph node metastases in gallbladder cancer without serosal invasion.

Gallbladder cancer without serosal invasion is often diagnosed during the pathologic examination of a gallbladder removed for presumed benign disease. The role of reoperative procedures in these patients is not well established, making it important to define prognostic factors that predict cancer spread. To determine if the pattern of immunohistochemical staining with a monoclonal antibody against CA 19-9 could predict lymph node spread of cancer, 23 patients with gallbladder cancer without serosal invasion were reviewed. CA 19-9 reaction was present in pathology specimens from all 23 patients. Twelve samples (52.2%) showed CA 19-9 in the stroma adjacent to cancer cells, while the remaining 11 did not show any stromal staining against CA 19-9. Lymph node development was found in only 2 (18.2%) of these 11 patients in the nonstromal staining group and 9 (75%) of the 12 patients in the stromal staining group. As these differences were statistically significant, we conclude that immunohistochemical localization of CA 19-9 in gallbladder cancer may be useful in predicting the presence or absence of lymph node involvement, and in developing a rational approach for a reoperative procedure.

Aged↗
PubMedDate not supplied

Prediction of lymph node metastasis and prognosis from the assay of the expression of proliferating cell nuclear antigen and DNA ploidy in gastric cancer.

Cell proliferation of 174 specimens obtained from the primary gastric cancers using endoscopic biopsy was investigated by immunohistochemical analysis with the monoclonal antibody PC10, which recognizes a proliferating cell nuclear antigen (PCNA) in formalin-fixed and paraffin-embedded material. All the examined samples showed nuclear staining for PCNA in cancer cells. The investigation was to test the correlation between PCNA labeling and lymph node metastasis. DNA aneuploidy was often encountered in tumors with nodal involvement and lymphatic invasion. The logistic regression analysis identified PCNA labeling rates (LRs), tumor size, and macroscopic type as independent significant factors for lymph node metastasis. When the PCNA LRs and clinicopathologic parameters were entered into the Cox regression analysis, PCNA LRs and DNA ploidy emerged as independent significant prognostic factors. In addition, combination assay of PCNA LRs and DNA ploidy yielded a powerful prognostic indication for patients with gastric cancer.

Bromodeoxyuridine↗
PubMedDate not supplied

p53 detection as a prognostic factor in early gastric cancer.

Immunohistochemical detection of p53 was performed in archival material of 129 early gastric cancers. Positive staining was detected in 22.5% (29/129) of the cases. No significant association could be established with any clinicopathological criteria but a trend of a higher rate of p53 detection was observed among large tumors (> 6 cm) and in cases with lymph node involvement. Prognosis was significantly worse for patients with p53-positive staining tumors. The 5-year survival rate was 92.1% for patients with p53-negative tumors and 71.2% for those with positive malignancies (p = 0.001). p53 detection and lymph node involvement emerged as independent prognostic factors in a Cox model including other clinicopathological criteria. Immunochemical detection of p53 may become an important aid in the preoperative evaluation of patients with early gastric cancer.

Humans↗
PubMedDate not supplied

Usefulness of the detection of Toxoplasma gondii antigens in AIDS patients.

Toxoplasmic encephalitis (TE) is a mayor cause of central nervous system infection in patients with acquired immunodeficiency syndrome (AIDS). Toxoplasma antibodies were detected in 56 of 79 patients with AIDS (71%), in the present study. Fourteen out of 57 seropositive patients developed TF (25%) and had Toxoplasma gondii antigen detected in their urine. For this, most of them received an effective therapy, with the subsequent disappearance of the symptoms and discontinuity of excretion of the T. gondii antigens. Our results suggest that the monitoring of T. gondii antigen in the urine of AIDS patients may be useful to decide on the proper time for therapy, as well as to avoid the beginning of neurologic signs in these patients.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Toxoplasma gondii antigenuria in patients with acquired immune deficiency syndrome.

A longitudinal study was performed with sera and urine of patients with acquired immune deficiency syndrome (AIDS), taken before, during and after clinically Toxoplasma infection. The tested patients were followed for an average of two years. The titres of the specific IgG and IgM antibodies were measured by an indirect fluorescent antibody test (IFAT), and the appearance of circulating antigens of T. gondii was determined in 36 urine samples of 13 patients with neurotoxoplasmosis by means of the coagglutination test. The presence of T. gondii antigens in the urine of AIDS patients by this test was correlated with the immunoblot technique, with clinical symptoms and also with pathological findings. Our results indicate that the detection of T. gondii antigens in the urine of AIDS patients can be regarded as a rapid and efficient method for the diagnosis of acute toxoplasmosis.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Drug resistance patterns among hospitalized tuberculous patients in Rio de Janeiro, Brazil, 1993-1994.

The purpose of this study was to analyze the prevalence and risk factors for drug resistance among hospitalized patients in two tertiary care centers, an acquired immunodeficiency syndrome (AIDS) reference center and a sanatorium, in Rio de Janeiro, Brazil. From 1993-1994, 389 patients were diagnosed as having tuberculosis (TB). Isolates from 265 patients were tested for in vitro susceptibility to rifampin and isoniazid. Resistance to one or more drugs was detected in 44 patients (16.6%) and was significantly more common among recurrent cases in both hospitals (p=0.03 in the AIDS center and p=0.001 in the sanatorium). Twenty seven patients (10.2%) had isolates resistant to both isoniazid and rifampin. Multi-drug resistance was associated with human immunodeficiency virus (HIV) infection among patients who had never been treated for TB. In conclusion, drug-resistant TB is high in hospitalized patients in Rio de Janeiro, especially among HIV infected patients. Therefore, measures to control TB and prevent nosocomial transmission need urgently to be set up in the Brazilian hospitals.

AIDS-Related Opportunistic Infections↗