Non-invasive brain stimulation (NIBS) probing the dorsolateral prefrontal cortex (DLPFC) has been shown to have little effect on working memory. The variability of NIBS responses might be explained by inter-subject brain anatomical variability. We investigated whether baseline cortical brain thickness of regions of interest was associated with working memory performance after NIBS by performing a secondary analysis of previously published research. Structural magnetic resonance imaging data were analyzed from healthy subjects who received transcranial direct current stimulation (tDCS), intermittent theta-burst stimulation (iTBS), and placebo. Twenty-two participants were randomly assigned to receive all the interventions in a random order. The working memory task was conducted after the end of each NIBS session. Regions of interest were the bilateral DLPFC, medial prefrontal cortex, and posterior cingulate cortex. Overall, 66 NIBS sessions were performed. Findings revealed a negative significant association between cortical thickness of the bilateral dorsolateral prefrontal cortex and reaction time for both tDCS (left: P=0.045, right: P=0.037) and iTBS (left: P=0.007, right: P=0.007) compared to placebo. A significant positive association was found for iTBS and posterior cingulate cortex (P=0.03). No association was found for accuracy. Our findings provide the first evidence that individual cortical thickness of healthy subjects might be associated with working memory performance following different NIBS interventions. Therefore, cortical thickness could explain - to some extent - the heterogeneous effects of NIBS probing the DLPFC.

Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [99mTc(MIBI)6]+ as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol:chloroform (25:75), Whatman 3MM paper and ethanol:chloroform (25:75), and the more expensive ITLC-SG and 1-propanol:chloroform (10:90) were suitable systems for the direct determination of radiochemical purity of [99mTc(MIBI)6]+ since impurities such as 99mTc-reduced-hydrolyzed (RH),99mTcO4 - and [99mTc(cysteine)2]-complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines.

The pathogenesis of nonsteroidal anti-inflammatory drug (NSAID) enteropathy is a complex process involving the uncoupling of mitochondrial oxidative phosphorylation and inhibition of cyclooxygenase (COX). Rofecoxib, a selective inhibitor of COX-2, has shown less gastric damage, but the same beneficial effect is not clear in the case of the small bowel. Fifty-seven male Wistar rats (250-350 g) were divided into three groups (N = 19 each) to evaluate the effect of this NSAID on the rat intestine. The groups received 2.5 mg/kg rofecoxib, 7.5 mg/kg indomethacin or water with 5% DMSO (control) given as a single dose by gavage 24 h before the beginning of the experiment. A macroscopic score was used to quantify intestinal lesions and intestinal permeability was measured using [51Cr]-ethylenediaminetetraacetic acid ([51Cr]-EDTA). The extent of intestinal lesion, indicated by a macroscopic score, was significantly lower when rofecoxib was administered compared to indomethacin (rofecoxib = 0.0 vs indomethacin = 63.6 ± 25.9; P < 0.05) and did not differ from control. The intestinal permeability to [51Cr]-EDTA was significantly increased after indomethacin (control = 1.82 ± 0.4 vs indomethacin = 9.12 ± 0.8%; P < 0.0001), but not after rofecoxib, whose effect did not differ significantly from control (control = 1.82 ± 0.4 vs rofecoxib = 2.17 ± 0.4%; ns), but was significantly different from indomethacin (indomethacin = 9.12 ± 0.8 vs rofecoxib = 2.17 ± 0.4%; P < 0.001). In conclusion, the present data show that rofecoxib is safer than indomethacin in rats because it does not induce macroscopic intestinal damage or increased intestinal permeability.

OBJETIVO: O diagnóstico de osteomielite crônica em atividade ou sobreposta a outras patologias é difícil, pois estas situações mascaram os achados radiológicos de infecção. A especificidade da cintilografia do esqueleto ou com gálio-67 também é reduzida pela influência da remodelação óssea na captação destes radiofármacos. Anticorpos policlonais marcados com tecnécio-99m (Tc-99m-IgG) apresentam captação independente do metabolismo ósseo, sendo um dos radiofármacos em investigação para avaliação mais específica de infecção. CASUÍSTICA E MÉTODO: Neste estudo comparou-se a cintilografia com Tc-99m-IgG, cintilografia óssea trifásica e cintilografia com gálio-67 no diagnóstico da osteomielite crônica em atividade em 23 segmentos ósseos; correlacionando-as com dados clínico-laboratoriais e radiológicos. RESULTADOS: Oito dos 23 segmentos foram classificados como infectados, 11 não infectados e quatro inconclusivos. A sensibilidade e especificidade encontradas para cintilografia óssea, com gálio-67 e com Tc-99m-IgG foram, respectivamente, 88 e 36%, 75 e 73%, 88 e 82%. CONCLUSÃO: Os resultados sugerem que a Tc-99m-IgG possa ser utilizada no diagnóstico da osteomielite crônica em atividade.

BACKGROUND: Active chronic osteomyelitis or complicating osteomyelitis are difficult to be diagnosed by radiological imaging modalities, such as plain radiograph and CT. They frequently cause increased bone remodeling, leading to nonspecific uptake of Tc-99m-bone scan agents and gallium-67. New radiopharmaceuticals with greater infection avidity are being developed, including the nonspecific polyclonal immunoglobulin (IgG) labeled with technetium-99m. Tc-99m-IgG may be available as a ready to use kit, with no reported side effects, low patient absorbed radiation dose and low cost. MATERIAL AND METHODS: 23 bone segments with suspected active chronic osteomyelitis or violated bone osteomyelitis were studied by Tc-99m-IgG scintigraphy. All patients underwent standard three-phase bone scintigraphy using methylene diphosphonate (Tc-99m-MDP), gallium-67 scintigraphy and plain radiographs, compared with clinical evaluation and laboratory tests values. RESULTS: Infection was found in 8 sites. Sensitivity and specificity for Tc-99m-MDP, gallium-67 and Tc-99m-IgG scintigraphy were, respectively, 88 and 36%, 75 and 73%, 88 and 82%. CONCLUSION: Tc-99m-IgG may be usefull in the scintigraphic evaluation of osteomyelitis.

Foram estudados 26 pacientes com epilepsia do lobo temporal clinicamente documentada por vários EEGs com atividade epileptiforme intercrítica e TC de crânio normal. SPECT com99mTC HMPAO e ressonância magnética (RM) foram realizados em todos os casos. 61.5% (n=16) das RM e 65.4% (n=17) dos SPECTs revelaram algum tipo de anormalidade. Atrofia hipocampal, nas imagens enfatizadas em Tl e presença de hipersinal nas imagens enfatizadas em T2, sugerindo esclerose mesial temporal, foram o principal achado (n=12; 75% das RM anormais). RM correlacionou-se ao EEG em 50% (n=13). Concordância entre RM e SPECT ocorreu em 30.7% (n=8) e entre SPECTe EEG em 57.7% (n=15). RM, SPECT e EEG foram congruentes em 26.9% (n=7). Estes resultados refletem o valor do SPECT intercrítico e RM na detecção e lateralização de anormalidades em epilepsia do lobo temporal. Por outro lado, em dois casos, o SPECT correlacionou-se mal com o EEG. Este método funcional não deve ser utilizado isoladamente na detecção de focos temporais. RM é mais útil do que a TC como recurso de neuroimagem na epilepsia do lobo temporal. Ela pode detectar pequenas lesões estruturais e esclerose mesial temporal, não facilmente identificáveis pela TC.

26 patients with temporal lobe epilepsy clinically documented by several abnormal interictal surface EEGs with typical unitemporal epileptiform activity and a normal CT scan were studied. Interictal99mTC HMPAO brain SPECT and MRI were performed in all subjects. Abnormalities were shown in 61.5% of MRI (n=16) and 65.4% of SPECT (n=17). Hippocampal atrophy associated to a high signal on T2-weighted MRI slices suggesting mesial temporal sclerosis was the main finding (n=12; 75% of abnormal MRI). MRI correlated well to surface EEG in 50% (n=13). There was also a good correlation between MRI and SPECT in 30.7% (n=8). SPECT and EEG were in agreement in 57.7% (n=l5). MRI, SPECT and EEG were congruent in 26.9% (n=7). These results support the usefulness of interictal brain SPECT and MRI in detecting lateralized abnormalities in temporal lobe epilepsy. On the other hand, in two cases, interictal SPECT correlated poorly with surface EEG. This functional method should not be used isolately in the detection of temporal lobe foci. MRI is more useful than CT as a neuroimaging technique in temporal lobe epilepsy. It may detect small structural lesions and mesial temporal lobe sclerosis which are not easily seen with traditional CT scanning.