241Am-Be(α,n) CHARACTERIZATION FOR A NEW LABORATORY FACILITY IN BRAZIL.

The Laboratório de Ciências Radiológicas is developing an irradiator for neutron survey meters calibration. Part of this work is related to the characterization of the neutron source that will be used in the irradiator. Therefore, a source of 241Am-Be(α,n) was characterized according to the following attributes: neutron energy distribution, anisotropy and emission rate. In order to make these values into high-level metrological references traceable by the Bureau International des Poids et Mesures, these measurements were taken at the Neutron Laboratory part of the Laboratório Nacional de Metrologia das Radiações Ionizantes. Results obtained for the source spectrum have strong adherence to the reference spectrum established by ISO 8529-1. The new laboratory for neutron calibration will allow calibration in an approximate ambient dose equivalent ranging 20-4500 µSv/h.

Antimutagenic and antioxidant activity of the essential oils of Citrus sinensis and Citrus latifolia.

The essential oils of Citrus sinensis and Citrus latifolia showed antimycotic activity against Candida spp. isolated from the oral cavity; they are neither mutagenic on the Ames test nor cytotoxic. Their main components are R-(+)-limonene, ß-thujene, α-myrcene and γ-terpinene. The aim of this work was to evaluate their antimutagenic and antioxidant capacities. Antimutagenic properties were evaluated against MNNG and ENNG on S. typhimurium TA100; against 2AA on strain TA98 and in front of 4NQO and NOR on strain TA102. Both were antimutagenic against MNNG (p < 0.001) but only C. latifolia was antimutagenic against ENNG (p < 0.001). Both presented antimutagenic activity against 2AA (p < 0.001). They were antioxidant against the ROS-generating compound 4NQO (p < 0.001) and the antibiotic NOR (p < 0.001). In the antioxidant evaluation, the activity in DPPH assay was in a range of 6-23% for C. sinensis and of 22-71% for C. latifolia. Both were antioxidant compared with BHT in ß-carotene bleaching assay and were able to decreased apoptosis in HaCat cells stimulated with H2O2. The levels of intracellular superoxide ion were lower in the presence of both oils. In conclusion, the essential oils of C. sinensis and C. latifolia are antimutagenic against at least three types of mutagens and have antioxidants properties.

Environmental stress in the Gulf of Mexico and its potential impact on public health.

The Deepwater Horizon (DWH) oil spill in the Gulf of Mexico was the largest maritime oil spill in history resulting in the accumulation of genotoxic substances in the air, soil, and water. This has potential far-reaching health impacts on cleanup field workers and on the populations living in the contaminated coastal areas. We have employed portable airborne particulate matter samplers (SKC Biosampler Impinger) and a genetically engineered bacterial reporter system (umu-ChromoTest from EBPI) to determine levels of genotoxicity of air samples collected from highly contaminated areas of coastal Louisiana including Grand Isle, Port Fourchon, and Elmer's Island in the spring, summer and fall of 2011, 2012, 2013 and 2014. Air samples collected from a non-contaminated area, Sea Rim State Park, Texas, served as a control for background airborne genotoxic particles. In comparison to controls, air samples from the contaminated areas demonstrated highly significant increases in genotoxicity with the highest values registered during the month of July in 2011, 2013, and 2014, in all three locations. This seasonal trend was disrupted in 2012, when the highest genotoxicity values were detected in October, which correlated with hurricane Isaac landfall in late August of 2012, about five weeks before a routine collection of fall air samples. Our data demonstrate: (i) high levels of air genotoxicity in the monitored areas over last four years post DWH oil spill; (ii) airborne particulate genotoxicity peaks in summers and correlates with high temperatures and high humidity; and (iii) this seasonal trend was disrupted by the hurricane Isaac landfall, which further supports the concept of a continuous negative impact of the oil spill in this region.

A comprehensive motor symptom monitoring and management system: the bradykinesia case.

The current work describes a methodology to automatically detect the severity of bradykinesia in motor disease patients using wireless, wearable accelerometers. This methodology was tested with cross validation through a sample of 20 Parkinson's disease patients. The assessment of methodology was carried out through some daily living activities which were detected using an activity recognition algorithm. The Unified Parkinson's Disease Rating Scale (UPDRS) severity classification of the algorithm coincides between 70 and 86% from that of a trained neurologist depending on the classifier used. These severities were calculated for 5 second segments of the signal with 50% of overlap. A bradykinesia profiler is also presented in this work. This profiler removes the overlap of the segments and calculates the confidence of the resulting events. It also calculates average severity, duration and symmetry values for those events. The profiler has been tested with a bogus dataset. Future work includes better training for the severity classifier with a larger sample and testing the profiler with real, longterm patient data in a projected pilot phase in three European hospitals.

Videoscopic assessment of the maintenance status of gamma radiography exposure containers employed in Brazil.

Industrial radiography is the most frequent method of non-destructive testing (NDT) used by Brazilian industrial facilities for investigating the material integrity of a test object. In Brazil, industrial radiography employs around 220 x-ray and 290 gamma radiography machines. About 90% of the latter uses iridium ((192)Ir) sources. The large majority of (192)Ir projectors in operation in Brazil have been in continuous usage for more than 25 years, which means that they are old and worn-out. Usually the majority of accidents concerning gamma radiography occur during the return of the source into the exposure container. Poor maintenance or imperfections of the internal channel of the exposure container can lead to accidental source exposure. In the present work the internal tube of 65 gamma machines from nine Brazilian companies that render gamma radiography services were analysed using an industrial videoscope. The internal images from the projectors were compared with the internal image of an apparatus that had never been used, i.e. has never received a radioactive source. From the 65 machines evaluated, nine showed irregularities of the internal tube. It was also observed that each company follows a different methodology for the maintenance and lubrication of the exposure containers and drive cables.

Lung exposure from inhalation of radon progeny: calculated from in vivo measurements of 210Pb in the skull.

To calculate the radiation dose to the lungs from the inhalation of radon and its short-lived progeny, an accurate estimate of cumulative exposure is necessary. In this preliminary study, the content of 210Pb in the skeleton is used to obtain a measure of integrated exposure to the lungs of people living in homes with above average concentrations of radon. Measurements of skeletal 210Pb made in vivo allow the exposed individuals to become, in effect, their own "samplers" and "dosimeters" through the normal physical and physiological processes of inhalation, deposition, and retention. 210Pb measurements have been made on 40 subjects whose homes have above average levels of radon. These data are used to obtain their cumulative lung exposures, defined as RLM (Respiratory Level Months). RLM is calculated from the numbers of atoms of RaA, RaB, and RaC,C' deposited in their respiratory systems over the time periods lived in the surveyed homes. The RLM values obtained are not significantly different than conventional WLM exposures calculated for the same time periods.

Strongyloidiasis detected by the agar plate culture method among patients infected by HIV.

To evaluate the rate of strongyloidiasis among HIV/AIDS patients, stools and duodenal juice were examined using the agar plate culture method. From January to June 1993, a total of 60 HIV/AIDS patients were required for duodenal aspirate and three serial samples of freshly passed stools. Stools and duodenal aspirate were dispensed on an agar plate culture; after incubation at 28 degrees C during 48 h, screening of plates was made at 10 x. The presence of furrows and worms of short buccal chamber and prominent genital primordium were positive for Strongyloides stercoralis. Most patients were men (91.7%); their mean age, of 33.9 years (SD +/- 10.6); their median CD4(+) T-cells count, of 105/microL (range of 12 to 646). S. stercoralis was detected in three patients (5%). In duodenal juice, the three patients showed the parasite, but in feces, only two (3.3%). In these two individuals, the worms were found in feces by agar culture and Faust's concentration method. The rate of S. stercoralis in feces of HIV/AIDS individuals (3.3%) by agar culture method was similar to that formerly reported from the general Mexican population (2.9%) using standard concentration procedures. Hence, in this immunocompromised population of a low prevalence city, there was no advantage to using an agar plate culture for strongyloidiasis.

Self-appraised health, HIV infection, and depression in female clients of AIDS counseling centers.

The development of effective coping strategies may require that women and men with HIV have an accurate, and to the greatest extent possible, positive, perception of their own health status. This has been found to be lacking among HIV-infected persons with limited education/information, including many minority adults. The objective of this study is to test several hypotheses that predict depression and perceived health in female adults with HIV. Data were obtained from 103 HIV-infected women (age > or = 18) who sought support, counseling, and maintenance services from one of four HIV care and referral centers in the mid-South. The results emphasize that perceived health status may fulfill a psychological distress-moderating or distress-aggravating function for women with HIV/AIDS.

A method to obtain subject background for low-level in-vivo measurements of the head.

Background for an in-vivo whole-body counter measurement is commonly obtained by averaging the counts of one or more matched (size, weight, gender) control subjects who have not been exposed to the radionuclide of interest. This limits the statistical significance to the time of the count, generally 30 min to 1 h when counting people. To obtain a human background with a small associated counting error in this manner would require counting the matching control subjects for a period much longer than they could tolerate. Also, it may not be possible to find a matching control subject who has not been exposed to the radionuclide of interest, as in the case of 210Pb, a nuclide that is normally present in air, food, and water, and to which everyone has been exposed all of their lives. This paper presents a method developed at New York University Medical Center, Nelson Institute of Environmental Medicine to obtain a matching background for any subject, for use in the measurement of 210Pb in the skull, in-vivo. It is obtained using a head phantom containing known amounts of potassium and calcium. The phantom, surrounded by three phoswich detectors in the same position as the subject's head, is counted repeatedly for long periods. Although it has been used to obtain "head" backgrounds only in the 210Pb spectral region, the method should be applicable to other regions of the low-energy phoswich spectrum.

Prevalence of anti-Toxoplasma gondii antibodies in Cebus spp in the Santa Fe Zoological Park of Medellín, Colombia.

The prevalence of anti-Toxoplasma gondii antibodies was studied in 47 nonhuman primates of the Cebus species in the Santa Fe Zoological Park in Medellín, Colombia. Specific IgG titers (greater than 1/64) were detected in 40.9% of C. albifrons studied (n = 22), 13.3% of C. capucinus (n = 15), and 0% of C. apella (n = 10). Specific IgM was not detected in any of the animals studied.

Detection of antigens of larval Taenia solium in the cerebrospinal fluid of patients with the use of HPLC and ELISA.

The cerebrospinal fluid (CSF) obtained from patients suspected of having neurocysticerosis (79 samples), as well as from control patients (without neurological symptoms), was separated using a high performance liquid chromatography gel filtration column. During the chromatographic separation, the eluted fractions were collected separately according to distinctive peaks. The elution characteristics of CSF components were identified by aligning more than 100 chromatograms and 6 distinctive peaks, eluting in consistent positions. Samples of each peak were tested in an enzyme-linked immunosorbent assay (ELISA) for the presence of larval antigens. Forty-four of the suspected 79 cases were found to have larval antigens in their CSF and these antigens were detected in peak no. 2, the mean of which is approximately 110,000 molecular weight. Also, in some cases, larval antigens were found in peak no. 1; however, we were able to detect them in only 23 CSF samples out of 44 CSF samples in which larval antigens were present in peak no. 2. Nine of these 23 CSF samples (derived from 79 patients in which neurocysticercosis was suspected) were later confirmed by histopathology. Values of ELISA readings of 5 CSF samples obtained from control patients (0.054 +/- 0.064) were considered negative. Thus, in 44 of 79 CSF samples from patients suspected of having neurocysticercosis, the ELISA values were highly positive (0.551 +/- 0.293). The remaining 35 CSF samples gave ELISA readings of 0.092 +/- 0.062, which were not significantly different from values obtained with CSF of control patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of Taenia solium antigens in cerebrospinal fluid and larval antigens from patients with neurocysticercosis.

Two antigens (190 and 230 kDa) of the larvae of Taenia solium were detected in the cerebrospinal fluid (CSF) of 14 of 18 patients in which neurocysticercosis was suspected. Nine of these were confirmed by histopathology. Seven antigens were detected in cyst fluid of T. solium larvae removed from the brains of 6 infected patients. Two of these antigens had the same Mr as the T. solium antigens detected in the CSF. Polyacrylamide gel electrophoresis and electro-immunoblotting analyses were used for the identification and characterization. Antibodies in rabbit anti-larval antiserum and antibodies in sera of infected individuals recognized the same larval antigens in the larval cyst fluids and in the CSF of infected patients.

Immunochemical detection of antigens of larval Taenia solium and anti-larval antibodies in the cerebrospinal fluid of patients with neurocysticercosis.

A simple and quantitative enzyme-linked immunosorbent assay (ELISA) has been developed for the detection of antigens of larval Taenia solium in the cerebrospinal fluid (CSF) of patients with cerebral cysticercosis. Another ELISA was developed for detecting antibodies in CSF against larval antigens. The examination of sixteen patients with clinical diagnosis of cerebral cysticercosis revealed that eleven patients had both circulating larval antigens and anti-larval IgG (but not IgM) antibodies in their cerebrospinal fluids. Of these patients, those with surgically and histologically confirmed infections were all positive by the two tests. CSF samples from nine normal individuals and from six patients suffering from proven neurological disorders other than neurocysticercosis were negative for both tests. In development of these assays it was found that cross-linking of antigens to microtiter plates further improved the performance of the ELISA. The results of this study suggest that either or both of these tests may be useful in discriminating between neurocysticerosis and other clinically related diseases.

Antigen-antibody analyses in neurocysticercosis.

In this report we show that there are 37 polypeptides of larval Taenia solium which react with antibodies from humans with neurocysticercosis. Six of these 37 polypeptides are recognized by antibodies present in the sera of both patients and control individuals. Thus, a minimum of 31 antigens are specific for cysticerci. We describe herein the antigens more frequently recognized by the patients, and the immunoglobulin classes favored in antibody production against each of the cysticercal antigens. It was found that there are 10 major polypeptides with molecular weights of 200,000, 64,000, 62,000-61,000, 53,000, 45,000, 41,000, 36,000-35,000, 30,000 and 16,000 daltons. About 65% of the larval components found to be antigenic are glycoproteins with oligosaccharide chains containing N-acetyl-D-glycosamine and alpha-D-galactose. These results suggest that the sugar moieties of glycoproteins may play a role in the antigenicity of larval T. solium. Based on these observations polypeptides with molecular weights of 64,000, 53,000, and 32,000-30,000 daltons are probably the best choice as sources of antigen to develop an optimal immunological test for the serological diagnosis of neurocysticercosis.