Cytochrome P450 CYP1B1 activity in renal cell carcinoma

Renal cell carcinoma (RCC) is the most common malignancy of the kidney and has a poor prognosis due to its late presentation and resistance to current anticancer drugs. One mechanism of drug resistance, which is potentially amenable to therapeutic intervention, is based on studies in our laboratory. CYP1B1 is a cytochrome P450 enzyme overexpressed in a variety of malignant tumours. Our studies are now elucidating a functional role for CYP1B1 in drug resistance. Cytochrome P450 reductase (P450R) is required for optimal metabolic activity of CYP1B1. Both CYP1B1 and P450R can catalyse the biotransformation of anticancer drugs at the site of the tumour. In this investigation, we determined the expression of CYP1B1 and P450R in samples of normal kidney and RCC (11 paired normal and tumour and a further 15 tumour samples). The O-deethylation of ethoxyresorufin to resorufin was used to measure CYP1B1 activity in RCC. Cytochrome P450 reductase activity was determined by following the reduction of cytochrome c at 550 nm. The key finding of this study was the presence of active CYP1B1 in 70% of RCC. Coincubation with the CYP1B1 inhibitor alpha-naphthoflavone (10nM) inhibited this activity. No corresponding CYP1B1 activity was detected in any of the normal tissue examined (n = 11). Measurable levels of active P450R were determined in all normal (n = 11) and tumour samples (n = 26). The presence of detectable CYP1B1, which is capable of metabolising anticancer drugs in tumour cells, highlights a novel target for therapeutic intervention

Executive functioning in patients with blepharospasm in comparison with patients with hemifacial spasm Funções executivas em pacientes com blefaroespasmo em comparação a pacientes com espasmo hemifacial

BACKGROUND: Non-motor symptoms have been described in primary dystonia, but the results on cognitive impairment in this condition are discordant. Blepharospasm (BM) is a type of primary focal dystonia characterized by recurrent and involuntary eye blinking. Hemifacial spasm (HS), a condition with different pathophysiology, constitutes an adequate control group when investigating non-motor disturbances in BM. OBJECTIVE:To compare the performance of patients with BM and HS in the Frontal Assessment Battery (FAB). METHOD: Twenty-two patients with BM and 29 patients with HS were submitted to the FAB and the Mini-Mental State Examination (MMSE). FAB scores were compared between the two groups. Correlations between FAB and sociodemographic and clinical variables were calculated. RESULTS: BM group was not different from HS in relation to gender, age, length of symptoms, educational level and performance in the MMSE. FAB scores were also similar in both groups. FAB scores correlated negatively with age and positively with educational level and MMSE scores. CONCLUSION: Executive functioning as assessed by FAB is not altered in BM in comparison with HS.<br>INTRODUÇÃO: Alterações não-motoras são descritas na distonia primária, embora sejam conflitantes os resultados sobre prejuízo cognitivo nessa condição. Blefaroespasmo (BE) é um tipo de distonia primária focal caracterizada por contrações recorrentes e involuntárias das pálpebras. Espasmo hemifacial (EH), cuja fisiopatologia é distinta do BE, constitui bom grupo controle quando se investiga alterações não-motoras no BE. OBJETIVO: Comparar o desempenho de pacientes com BE e com EH na Bateria de Avaliação Frontal (BAF). MÉTODO: BAF e Mini-Exame do Estado Mental (MEEM) foram administrados a 22 pacientes com BE e 29 com EH. Os escores da BAF foram comparados entre os dois grupos. Correlações entre resultados na BAF e variáveis sócio-demográficas e clínicas foram calculadas. RESULTADOS: Os grupos BE e EH foram semelhantes quanto a gênero, idade, duração dos sintomas, escolaridade e desempenho no MEEM. Os escores dos dois grupos na BAF foram também similares, correlacionando-se negativamente com idade e positivamente com escolaridade e desempenho no MEEM. CONCLUSÃO: As funções executivas avaliadas pela BAF não estão alteradas no BE em relação ao EH

Application of Methyl-TROSY to a Large Paramagnetic Membrane Protein Without Perdeuteration: \u3csup\u3e13\u3c/sup\u3eC-MMTS-labeled NADPH-cytochrome P450 Oxidoreductase

NMR spectroscopy of membrane proteins involved in electron transport is difficult due to the presence of both the lipids and paramagnetic centers. Here we report the solution NMR study of the NADPH-cytochrome P450 oxidoreductase (POR) in its reduced and oxidized states. We interrogate POR, first, in its truncated soluble form (70 kDa), which is followed by experiments with the full-length protein incorporated in a lipid nanodisc (240 kDa). To overcome paramagnetic relaxation in the reduced state of POR as well as the signal broadening due to its high molecular weight, we utilized the methyl-TROSY approach. Extrinsic 13C-methyl groups were introduced by modifying the engineered surface-exposed cysteines with methyl-methanethiosulfonate. Chemical shift dispersion of the resonances from different sites in POR was sufficient to monitor differential effects of the reduction–oxidation process and conformation changes in the POR structure related to its function. Despite the high molecular weight of the POR-nanodisc complex, the surface-localized 13C-methyl probes were sufficiently mobile to allow for signal detection at 600 MHz without perdeuteration. This work demonstrates a potential of the solution methyl-TROSY in analysis of structure, dynamics, and function of POR, which may also be applicable to similar paramagnetic and flexible membrane proteins

Planetary Mapping: A historical overview

The development of the methods of visualization, control, and content of planetary maps goes in parallel with terrestrial ones. Both reflect technological, scientific, sociopolitical, and graphic design changes. However, while terrestrial maps are ubiquitous and show abstract or iconic representations of the Earth features, planetary surfaces are much more frequently represented with uninterpreted images, despite the wealth of planetary spatial data. In this paper, we highlight the key maps and map series made before the space age and the new cartographic methods introduced in the early 1960s when rectified, geologic and airbrush maps, and space-borne planetary photography, revolutionized the way we can look at planetary surfaces. This chapter also highlights the most recent novel approaches in planetary cartography