Long-term performance assessment of HPGE detectors used in the neutron activation analysis laboratory of IPEN-CNEN/SP (Brazil).

In this work, verification data for 11 HPGe detectors from two different manufacturers and three different intrinsic configurations were analyzed in respect to the stability of both the efficiency and resolution for the 122keV peak from 57Co and the 1332keV peak from 60Co. The results allow a discussion about the stability of these parameters over time (in some cases, almost 15 years), their sensitivity to imminent detector failures and their performance after a failure has been corrected; moreover, the results show a clear correlation between the manufacturer or configuration and the long-term performance of the detector.

Neural changes in the primate brain correlated with the evolution of complex motor skills.

Complex motor skills of eventual benefit can be learned after considerable trial and error. What do structural brain changes that accompany such effortful long-term learning tell us about the mechanisms for developing innovative behavior? Using MRI, we monitored brain structure before, during and after four marmosets learnt to use a rake, over a long period of 10-13 months. Throughout learning, improvements in dexterity and visuo-motor co-ordination correlated with increased volume in the lateral extrastriate cortex. During late learning, when the most complex behavior was maintained by sustained motivation to acquire the skill, the volume of the nucleus accumbens increased. These findings reflect the motivational state required to learn, and show accelerated function in higher visual cortex that is consistent with neurocognitive divergence across a spectrum of primate species.

Clinical course of drug-induced hypersensitivity syndrome treated without systemic corticosteroids.

BACKGROUND/AIM: Drug-induced hypersensitivity syndrome (DIHS) is a severe reaction to drugs which characteristically occurs after a long latency period. In addition, human herpes virus 6 (HHV-6) reactivation is a characteristic finding in DIHS, which has been known to be related to disease severity. Because DIHS has generally been treated by systemic corticosteroids, the natural clinical course is not clear. METHODS: Data for patients with both DIHS and HHV-6 reactivation were retrospectively collected from four hospitals. RESULTS: Data were collected on 12 patients ranging in age from 21 to 76 years (median, 65.5). All cases had been suspected of DIHS at their initial visit, and the elevation of serum anti-HHV-6 antibody had been confirmed (4-256 times: median; 32). The culprit drugs were carbamazepine (6), salazosulfapyridine (4), mexiletine (1) and zonisamide (1). The period of latency from the first administration of the drug ranged from 15 to 50 days (median, 30). All patients were treated conservatively for DIHS without systemic corticosteroids. The peaks of the patients' symptoms and laboratory findings were as follows (days from the onset of skin lesions): fever, 4-16 (median, 10.5); liver abnormality, 3-22 (median, 7.5); leukocytosis, 7-20 (median, 9). All patients recovered without pneumonia, myocarditis, nephritis or other systemic disease, from 7 to 37 days (median, 18) after withdrawal of the drug and from 11 to 44 days (median, 21) after the onset of skin lesions. CONCLUSION: It might be unnecessary to give systemic corticosteroids immediately to all patients suspected of having DIHS.

Periventricular and deep white matter leukoaraiosis have a closer association with cerebral microbleeds than age.

BACKGROUND: Taking an advantage of the high sensitivity of 3D T2*-weighted gradient-recalled-echo (GRE) imaging to cerebral microbleeds, we investigated the relationship between cerebral microbleeds and leukoaraiosis. METHODS: Participants aged 40 years or more have been evaluated for the presence of cerebral microbleeds using 3D T2*-GRE sequence since 2006. The severity of periventricular hyperintensity (PVH) and deep white matter hyperintensity (DWMH) on fluid attenuated inversion recovery images was assessed using Fazekas rating scales. Multivariate logistic regression analyses were conducted after adjustment for stroke subtype, age, PVH, DWMH, hypertension, dementia, and use of platelet aggregation inhibitors. Additionally, we examined the association between cerebral microbleeds and other covariates using a Pearson's correlation analysis. RESULTS: Amongst 389 patients, 67 patients had a single microbleed and 93 had multiple microbleeds. The prevalence of microbleeds was 83% amongst 53 patients with intracerebral hemorrhage (ICH), 49% amongst 173 with infarction, and 20% amongst 163 without any type of stroke. In the multivariate analyses, the odds ratio (95% CIs) of microbleed detection was 10.1, (4.12-24.8) for ICH, 2.33 (1.12-4.85) for atherosclerotic infarction, 1.66 (1.10-2.48) for PVH, and 1.49 (1.02-2.19) for DWMH. In the Pearson's correlation analysis, cerebral microbleeds were closely related to PVH (Pearson's correlation coefficient; 0.48) and DWMH (0.37), compared with age (0.16). CONCLUSIONS: High-grade PVH, high-grade DWMH, ICH, and atherosclerotic infarction were significantly independent predictors for cerebral microbleeds. In addition, we found that the grades of PVH and DWMH have a closer association with the number of cerebral microbleeds than age.

Ablation of demineralized dentin using a mid-infrared tunable nanosecond pulsed laser at 6 µm wavelength range for selective excavation of carious dentin.

In dental clinic, some lasers have already realized the optical drilling of dental hard tissue. However, conventional lasers lack the ability to discriminate and excavate carious tissue only, and still depend on the dentist's ability. The objective of this study is to develop a selective excavation of carious dentin by using the laser ablation with 6 µm wavelength range. Bovine dentin demineralized with lactic acid solution was used as a carious dentin model. A mid-infrared tunable pulsed laser was obtained by difference-frequency generation technique. The wavelength was tuned around the absorption bands called amide 1 and amide 2. In the wavelength range from 5.75 to 6.60 µm, the difference of ablation depth between demineralized and normal dentin was observed. The wavelength at 6.02 µm and the average power density of 15 W/cm(2), demineralized dentin was removed selectively with less-invasive effect on normal dentin. The wavelength at 6.42 µm required the increase of average power density, but also showed the possibility of selective ablation. In the near future, development of compact laser device will open the minimal invasive laser treatment to the dental clinic.

[Vacuum-assisted closure therapy for the treatment of sternal wound infection after cardiac surgery].

Sternal wound infection is still one of the critical and challenging complications after cardiac surgery. Vacuum-assisted closure (VAC) therapy is a unique and simple system that helps promote wound healing. We report 3 cases with the sternal wound infection after cardiac surgery, in which VAC therapy was applied between January, 2005 and April, 2007. Two of them had good response to VAC therapy and had their wound healed after 3 and 5 weeks, respectively. However, the remaining case, in which bilateral internal thoracic artery had been taken down for coronary artery bypass grafting (CABG) and osteomyelitis of the sternum was not well controlled, did not respond to VAC therapy. Our results suggested that VAC might facilitate wound healing of the patients with sternal wound infection only after abscess was drained and opened, while it might not be useful for the patents with osteomyelitis.

Tear function and lipid layer alterations in dry eye patients with chronic graft-vs-host disease.

PURPOSE: To investigate the changes in the tear film lipid layer in haematopoietic stem cell transplantation (HSCT) patients with dry eye (DE) associated with chronic graft-vs-host disease (cGVHD) and compare with HSCT recipients without DE. METHODS: We performed a prospective study in 10 HSCT patients with DE associated with cGVHD and 11 HSCT recipients without DE. We performed Schirmer's test, tear film break up time examinations, ocular surface dye staining and meibum expressibility test and DR-1 tear film lipid layer interferometry. DR-1 interferometry images of the tear film surface were assigned a 'DR-1 grade' according to the Yokoi severity grading system. The DR-1 grades were analysed according to the presence or absence of DE, conjunctival fibrosis and systemic cGVHD. RESULTS: The mean DR-1 severity grade in patients with DE related to cGVHD (DE/cGVHD group; 3.9+/-0.9) was significantly higher than in patients without DE after HSCT (non-DE/non-cGVHD group; 1.3+/-0.6; P<0.05). The DR-1 grade for HSCT recipients with conjunctival fibrosis was significantly higher than in patients without conjunctival fibrosis (P<0.05). When DE severity was graded according to the recommendation of the 2007 Dry Eye Workshop Report, our results showed a correlation between the severity of DE and DR-1 grades (r=0.8812, P<0.0001). CONCLUSION: DR-1 interferometry may be applicable to diagnosing DE and evaluating its progression subsequent to HSCT.

Implantação das boas práticas de fabricação em uma queijaria artesanal, produtora do queijo tipo Boursin / Implementation of good manufacturing practices in an industrial installation, a producer of Boursin cheese

Atualmente a indústria de alimentos se encontra em transição. Os produtos artesanais devem obedecer a um padrão de qualidade mantendo, dessa forma, um mercado competitivo e promissor. O objetivo desse trabalho foi avaliar o fluxograma de produção artesanal do queijo tipo Boursin, desde a ordenha até o envase do produto. As análises utilizadas para a massa do queijo e da água da ordenha foram a de Número Mais Provável (NMP) para coliformes a 45°C. Os resultados mostraram que o ponto crítico se encontrava na higiene de ordenha e no tempo e temperatura de dessora, apresentando NMP maior que 240 coliformes fecais por grama.(...) Conclui-se que o binômio tempo e temperatura são pontos importantes não só para a indústria de laticínios como também para a produção artesanal de queijos, pois estes estão diretamente relacionados com a multiplicação e fermentação microbiana.

Assessment of atmospheric metallic pollution in the metropolitan region of São Paulo, Brazil, employing Tillandsia usneoides L. as biomonitor.

Tillandsia usneoides L. is an epiphytic bromeliad plant able to absorb water and nutrients directly from the air. For this reason this species was selected to carry out a monitoring study of air pollution in the metropolitan region of São Paulo, Brazil. Five consecutive transplantation experiments (8 weeks each) were performed in 10 sites of the city, submitted to different sources of air pollution (industrial, vehicular), using plants collected from an unpolluted area. After exposure, trace metals were analyzed in the plant by instrumental neutron activation analysis. Traffic-related elements such as Zn and Ba presented high concentrations in exposure sites near to heavy traffic avenues (cars, buses and trucks) and may be associated to vehicular sources. For Zn and Co the highest contents were related to industrial zones and can be associated to the presence of anthropogenic emission sources. The rare earth elements, Fe and Rb, probably have soil particles as main source.

Varicose veins associated with CADASIL result from a novel mutation in the Notch3 gene.

No genetically diagnosed cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) pedigrees with venous insufficiency have been described. In a CADASIL pedigree with varicose veins, the authors have identified a novel heterozygous mutation in the 3' splice acceptor site of intron 15 of the Notch3 gene. This, based on mRNA analysis, resulted in skipping of exon 16 including eight cysteine residues of EGF-like repeats.

Characterization of trace elements in Casearia medicinal plant by neutron activation analysis.

Leaves of Casearia sylvestris, Casearia decandra and Casearia obliqua plant species, collected at the Atlantic Forest in Brazil, were analyzed by using instrumental neutron activation analysis (INAA). Short and long irradiations using thermal neutron flux of the IEA-R1 nuclear reactor were carried out for these analyses. Concentrations of Ca, K and Mg were found in these samples at the percentage levels, Br, Cl, Fe, Mn, Na, Rb and Zn at the microg g(-1) levels and Co, Cr, Cs, La, and Sc at the microg kg(-1) levels. Comparisons were made among the element concentrations obtained in these three Casearia species and significant differences were found for the elements Cl, Co, Cs, Cr, La, Mn, Na and Sc. The precision and the accuracy of the results were evaluated by analyzing the certified reference materials NIST-1515 Apple Leaves and NIST-1573a Tomato Leaves.

Diesel emissions significantly influence composition and mutagenicity of ambient particles: a case study in São Paulo, Brazil.

In 2003, a bus strike paralyzed the fleet of buses in Sao Paulo, Brazil during 3 days, from 6 to 8 of April, the complete interruption of services being achieved on the 7th. We evaluated the effect of the absence of this source of pollution on the composition, mutagenicity, and toxicity of the fine particulate material collected during this period. Particles were sampled in glass fiber filters on days 7 and 15 of April of 2003 (strike and nonstrike days, respectively), using a high-volume sampler. Trace element determinations (As, Br, Co, Cl, Fe, La, Mn, Sb, Sc, and Th) of particulate material samples were carried out by neutron activation analysis. Sulfur determination was done by X-ray fluorescence analysis. The ratio between nonstrike/strike concentrations of hydrocarbons associated with automotive emissions (benzene, toluene, ethyl-benzene, and xylenes; BTEX) was determined by gas chromatography/mass spectrometry. Mutagenesis of testing solutions was determined by means of the Tradescantia micronucleus assay in early tetrads of Tradescantia pallida. The inhibition of mitosis of the cells of the primary meristema of the root tips of Allium cepa was used as an index of the toxicity. Fine particle trace element contents were lower during the strike. The concentrations of sulfur and BTEX were 50% and 39.3% lower, respectively, on the strike day. A significant (P=0.038) reduction of micronuclei induced by fine particles sampled during the strike was observed. No effect of the strike on toxicity was detected. These results indicate that a program aiming to reduce emissions of the bus fleet in our town may impact positively the air quality by reducing the mutagenic potential of ambient particles.

WT1 expression level and clinical factors in multiple myeloma.

Although Wilm's Tuomor gene (WT1) was first identified as a tumor suppressor gene for Wilm's tumor, WT1 overexpression has been detected in different malignant cell types including leukemia. Increased expression of WT1 in acute leukemia is potentially used as a marker of minimal residual disease. However, the significance of the gene for multiple myeloma is still not clear. To determine the clinical relevance of WT1 expression in multiple myeloma, we examined the association of clinical parameters and WT1 expression in bone marrow for 17 newly diagnosed multiple myeloma patients. WT1 was assessed by real-time quantitative polymerase chain reaction (RQ-PCR) and calculated standardized WT1 expression level per 100 plasma cells in the bone marrow specimen as "corrected WT1". The expression of standardized WT1 and corrected WT1 in myeloma was 59 to 1,600 copies/microg RNA and 0.05 to 406.3 copies/microg RNA/100 plasma cells, respectively, lower than in leukemia. WT1 transcripts increased when clinical factors worsen, including the stage, amount of M protein, Hb, platelet count, blood urea nitrogen (BUN), creatinine, serum alkaline phosphatase (ALP), calcium, beta2-microglobulin, thymidine kinase activity (TK), and C-reactive protein (CRP). In conclusion, the expression level of WT1 could be an additional marker to the standard parameters considered in risk assessment for multiple myeloma.

Uranium incorporation biokinetics in poultry bonesas function of phytase doses

Direct alpha-energy spectroscopy in liquids is possible by placing a chemically selective polymer thin film upon the surface of passivated silicon diodes. By utilizing polymer thin films with high affinity for actinides, we have been able to selectively concentrate actinides of interest upon the diode surface, resulting in a substantial increase in sensitivity relative to a direct measurement. With this film coated diodes, we were able to obtain in-situ alpha spectra with energy resolution comparable to that of conventional alpha-spectroscopy. The response of the thin film coated diode was found to be linear over . The sensitivity and reversibility is a function of the membrane complexation chemistry.

Long-term accumulation of uranium in bones of Wistar rats as a function of intake dosages.

Groups of Wistar rats were fed with ration doped with uranyl nitrate at concentration A ranging from 0.5 to 100 ppm, starting after the weaning period and lasting until the postpuberty period when the animals were sacrificed. Uranium in the ashes of bones was determined by neutron activation analysis. It was found that the uranium concentration in the bones, as a function of A, exhibits a change in its slope at approximately 20 ppm-a probable consequence of the malfunctioning of kidneys. The uranium transfer coefficient was obtained and an analytical expression was fitted into the data, thus allowing extrapolation down to low doses. Internal and localized doses were calculated. Absorbed doses exceeded the critical dose, even for the lowest uranium dosage.

Long-term accumulation and microdistribution of uranium in the bone and marrow of beagle dog.

The accumulation and microdistribution of uranium in the bone and marrow of Beagle dogs were determined by both neutron activation and neutron-fission analysis. The experiment started immediately after the weaning period, lasting till maturity. Two animal groups were fed daily with uranyl nitrate at concentrations of 20 and 100 microg g(-1) food. Of the two measuring techniques, uranium accumulated along the marrow as much as in the bone, contrary to the results obtained with single, acute doses. The role played by this finding for the evaluation of radiobiological long-term risks is discussed. It was demonstrated, by means of a biokinetical approach, that the long-term accumulation of uranium in bone and marrow could be described by a piling up of single dose daily incorporation.

Reproductive status of western mosquitofish inhabiting selenium-contaminated waters in the Grassland water district, Merced county, California.

This study was implemented to determine if western mosquitofish (Gambusia affinis) populations in the Grassland Water District suffer from impaired reproduction because of seleniferous inflows of agricultural drainwater from the Grassland Bypass Project. During June to July 2001, laboratory trials with pregnant female fish collected from two seleniferous treatment sites exposed to selenium-laden drainwater and two nonseleniferous reference sites yielded fry that averaged > 96% survival at birth. In addition, none of the newborn fry exhibited evidence of teratogenesis, a typical consequence of selenium toxicity. Chemical analysis of postpartum female fish and their newborn fry indicated that mosquitofish from seleniferous sites accumulated relatively high body burdens of selenium (3.96 to 17.5 microg selenium/g in postpartum female fish and 5.35 to 29.2 microg selenium/g in their fry), whereas those from nonseleniferous sites contained lower body burdens (0.40 to 2.72 microg selenium/g in postpartum female fish and 0.61 to 4.68 microg selenium/g in their fry). Collectively, these results strongly suggest that mosquitofish inhabiting selenium-contaminated waters are not experiencing adverse reproductive effects at current levels of selenium exposure.