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Biomedical subjects

N Katz

Publications and source records attributed to N Katz.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Control of schistosomiasis mansoni in Ravena (Sabará, state of Minas Gerais, Brazil) through water supply and quadrennial treatments.

In this study, the results obtained in a control programme of schistosomiasis in Ravena (Sabará, Minas Gerais) between 1980 and 1992 are evaluated. Control measures used in this programme were: specific treatment of the people infected with Schistosoma mansoni at four year-intervals (1980/84/88) and the supply of tap water to 90% of the residences in 1980. A significant reduction of the prevalence (36.7% to 11.5%, p < or = 0.05) and of the intensity of the infection (228.9 eggs per gram of feces (epg), s = 3.7 to 60.3 epg, s = 3.5, p < or = 0.05) was observed. No cases of the severe form of the disease were diagnosed in the area. Factors independently associated with the infection were in 1980 daily sand extraction and the lack of tap water in residences and in 1992 daily sand extraction and fishing and weekly swimming. Concluding, the supply of tap water together with quadrennial treatments significantly diminished both the prevalence and intensity of the S. mansoni infection, with the additional gain of persistent low indices even after four-year intervals between the treatments.

Brazil↗
PubMedDate not supplied

The serological differentiation of acute and chronic schistosomiasis japonica using IgA antibody to egg antigen.

Two groups of Schistosoma japonicum infected patients (acute and chronic) and non-infected individuals were studied using IgA antibody to egg antigen (SEA) and IgG and IgM antibodies to keyhole limpet haemocyanin (KLH). The means and standard deviation of the optical density in ELISA of acute, chronic and negative groups for IgA anti-SEA were 583 +/- 124.7, 98.2 +/- 78.8 and 82.2 +/- 39.3, respectively. There was a statistically significance between acute patients and chronic patients (P < 0.01). The means and standard deviation of IgG and IgM antibodies to KLH were 501.5 +/- 150.6, 113.0 +/- 79.1, 28.8 +/- 56.3 and 413.6 +/- 148.5, 70.2 +/- 14.8, 65.3 +/- 45.3, respectively. The detection results of IgA to SEA compared with the IgG and IgM to KLH did not demonstrate a significant difference (P < 0.01). The sensitivities of IgA to SEA and IgG and IgM antibodies to KLH for the detection of acute infection were 95.24%, 90.48% and 85.71%, respectively. Therefore, this study showed that the detection of IgA to SEA is also a useful new method for the serological differentiation of acute and chronic schistosomiasis japonica in humans.

Acute Disease↗
PubMedDate not supplied

Epidemiological characteristics of Schistosoma mansoni infection in rural and urban endemic areas of Minas Gerais, Brazil.

To compare the epidemiological profile and socioeconomic factors associated to the infection by Schistosoma mansoni in a rural and an urban endemic area a cross-sectional study was performed in Agua Branca de Minas (rural area) and Bela Fama (urban area), both situated in the State of Minas Gerais, Brazil. Two hundred and eighty eight individuals were surveyed in the rural area and 787 in the urban area. Water contact and socioeconomic questionnaires were used to identify risk factors for the infection. The prevalences of 38.8% and 9.7% and the geometric mean of eggs per gram of faeces of 117.8 and 62.3 were found in the rural and urban areas, respectively. By multivariate statistical analysis age groups over nine years old and previous specific treatment were associated with the infection in rural area. In urban area age over nine years old, low quality housing, weekly fishing and swimming were associated after adjustment by logistic regression.

Adolescent↗
PubMedDate not supplied

Circulating antigens levels in different clinical forms of the Schistosoma mansoni infection.

With the aim to evaluate the circulating cathodic antigen (CCA) levels in relation to the different clinical phases of Schistosoma sp. infection a sandwich ELISA using monoclonal antibody 5H11 was performed. The sera of three groups of 25 Brazilian patients with acute, intestinal and hepatosplenic forms of S. mansoni infection were tested and compared to a non-infected control group. Patients and control groups were matched for age and sex and the number of eggs per gram of feces was equally distributed among the three patient groups. Sensitivity of 100%, 72%, 52% of the assay was observed for the intestinal, hepatosplenic and acute toxemic groups respectively. The specificity was 100%. Intestinal and hepatosplenic groups presented CCA levels significantly higher in comparison to those observed for acute patients (F-ratio = 2,524; p = 0.000 and F-ratio = 6,314; p = 0.015 respectively). There was no significant difference of CCA serum levels between hepatosplenic and intestinal groups (F-ratio = 1,026; p = 0.316).

Acute Disease↗
PubMedDate not supplied

Ultrastructure of feminizing testicular Leydig cell tumors.

The ultrastructure of a feminizing testicular Leydig cell tumor was analytically compared with that of the five reported feminizing neoplasms and with that of the eight published masculinizing or hormonally inactive tumors. Certain observations were noteworthy but of uncertain significance. In the current case, nuclear outlines tended to be irregular, nuclear pores were relatively few, chromatin was often uniformly dispersed, and nucleoli were frequently multiple. Membranous whorls and "myelin figures" were common. Collectively, the nuclear aberrations were noted only in the two feminizing neoplasms studied by us. Other findings in the present case included abundant endoplasmic reticulum, swollen pleomorphic mitochondria, numerous lysosomes, "dark" and "light" Leydig cell nuclei, and specialized modifications of the plasma membrane. These observations were inconstantly present in the group as a whole, irrespective of hormonal activity. Employing present methods it is not feasible to correlate the fine anatomy of testicular Leydig cell tumors with their capability of hormonal function.

Adult↗
PubMedDate not supplied

Comparison of the performance of younger and older adults on three versions of a puzzle reproduction task.

OBJECTIVES: Because constructional ability is a crucial perceptual-motor skill that relates to daily functioning, it should be accurately assessed in clients with neurological dysfunction. This study examined three versions of the Puzzle Reproduction task (a constructional ability task) of the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) in order to determine whether a reduced-detail version of the task would be easier (i.e., require less time to complete) than the original version and whether a subplacement version would be more difficult to perform (i.e., require more time to complete) than the original version. In addition, the study examined whether older adult subjects would perform more slowly than younger adult subjects. METHODS: Seventy-two right-handed adults with no disabilities were divided into two age groups: 18 to 30 years old (n = 36) and 58 to 70 years old (n = 36). Each subject was tested on one of three versions of the LOTCA Puzzle Reproduction task (i.e., original subplacement, simplified). RESULTS: For the older subjects, the simplified version of the task required significantly less time than the original version, although there was not a significant time difference between the original and subplacement versions. For the younger subjects, the subplacement versions. required significantly more time than the original version, but there was no significant time difference between the original and simplified versions. Results also indicated that older subjects took significantly longer to perform all three versions of the task than did the younger subjects. CONCLUSION: The findings support the use of the simplified version of the LOTCA Puzzle Reproduction task with older adults or with persons with major cognitive-perceptual difficulties. Further studies of the level of difficulty of the subplacement version are needed to examine whether this version is more sensitive to constructional deficits in a sample of person with neurological impairments because even mild constructional deficits have been shown to relate to disabilities in daily functioning.

Adult↗
PubMedDate not supplied

[Assessment of schistosomiasis and other intestinal parasitoses in school children of the Bambuí municipality, Minas Gerais, Brazil].

This work was carried out with the purpose of determining the prevalence of intestinal parasitoses in the school children of Bambuí, through parasitological examinations (direct and Kato-Katz methods) and reevaluating the snails' breeding places described in the county. Of the 2,091 school children examined, 20.1% had at least one parasitic infection. Giardia lamblia, Entamoeba coli, Ascaris lumbricoides and hookworm are the most frequent parasites, with a prevalence of 6.2%, 6.2%, 4.8% and 1.4%, respectively. The hookworms were significantly more frequent among students from the rural area and in those aged over 14 years, while the prevalence of E. coli was greater in the urban area and the G. lamblia was more frequent in children under 6 years old. Only three children shed eggs of Schistosoma mansoni. The only intermediate host found was Biomphalaria glabrata and none of them was shedding cercariae of S. mansoni. When these data were compared with data from other surveys previously effected in the county, a decline was observed in the prevalence of all parasites. Some hypotheses which may explain this decline are discussed, such as: intense urbanization process and improvement of social-sanitary conditions of the county.

Adolescent↗
PubMedDate not supplied

Comparison of the tumor markers tumor M2-PK, CEA, CYFRA 21-1, NSE and SCC in the diagnosis of lung cancer.

The study presents data comparing the new tumor marker Tumor M2-PK with CEA, CYFRA 21-1, NSE and SCC in the diagnosis of lung cancer. Tumor M2-PK is quantitatively detectable in EDTA-plasma with a sensitive ELISA. The results of the tumor marker test were compared with respect to the different histological tumor types and with the tumor staging. So far 144 newly diagnosed lung cancer patients were included. Significantly elevated tumor marker concentrations were found with progressive tumor stages. The best correlation with the tumor stage was observed for Tumor M2-PK and CYFRA 21-1. Comparison of the sensitivities in the detection of lung cancer indicated that the Tumor M2-PK-test (sensitivity: 58%) is more efficient than the CEA-Test (sensitivity: 39%) or CYFRA 21-1 (sensitivity: 48%). Generally higher sensitivity for non-small cell lung cancer only was shown for Tumor M2-PK (sensitivity: 65%), CEA (sensitivity: 42%) and CYFRA 21-1 (sensitivity: 58%). For small-cell lung cancer the marker NSE was more sensitive than all other markers. Initial follow-up studies indicate that Tumor M2-PK and CYFRA 21-1 can be used to monitor disease with tumor progression or regression during chemotherapy. The present data indicated that Tumor M2-PK could be a valuable tumor marker for the detection of lung cancer.

Antigens, Neoplasm↗
PubMedDate not supplied

[Simultaneous determination of specific antigen, antibody and immune complexes in the serum of patients with chronic schistosomiasis].

The main steps of a sensitive and quantitative technique for the simultaneous determination, in the same microplate, of antigen, antibody and specific immune complexes has been described. The assay involved principles of the double sandwich technique used in the "Enzyme-Linked Immunosorbent Assay" (ELISA). The technique proved to be useful for the estimation of antigen, antibody and specific immune complexes in sera of patients with human chronic hepato-intestinal schistosomiasis.

Adolescent↗