CARLOS HENRIQUE DE MESQUITA

CARLOS HENRIQUE DE MESQUITA

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Increased adiposity by feeding growing rats a high-fat diet results in iron decompartmentalisation
2020 - LOBO, ALEXANDRE R.; GAIEVSKI, EDUARDO H.S.; MESQUITA, CARLOS H. de; DE CARLI, EDUARDO; TEIXEIRA, PRYSCILA D.S.; PEREIRA, ROSA M.R.; BORELLI, PRIMAVERA; SÁ, LILIAN R.M. de; COLLI, CELIA
The present study reports the effects of a high-fat (HF) diet of over 8 weeks on the Fe status of growing rats. Tissue Fe levels were analysed by atomic absorption spectrophotometry, and whole-body adiposity was measured by dual-energy X-ray absorptiometry. Histopathology and morphometry of adipose tissue were performed. Liver homogenates were used for measuring ferroportin-1 protein levels by immunoblotting, and transcript levels were used for Fe genes measured by real-time PCR. Tissue Fe pools were fit to a compartmental biokinetic model in which Fe was assessed using fourteen compartments and twenty-seven transfer constants (kj,i from tissue ‘i’ to tissue ‘j’) adapted from the International Commission on Radiological Protection (ICRP) 69. Ten kj,i were calculated from the experimental data using non-linear regression, and seventeen were estimated by allometry according to the formula ki;j ¼ a ×Mb. Validation of the model was carried out by comparing predicted and analysed Fe pool sizes in erythrocytes, the liver and the spleen. Body adiposity was negatively associated with serum Fe levels and positively associated with liver Fe stores. An inferred increase in Fe transfer from bone marrow to the liver paralleled higher hepatic Fe concentrations and ferritin heavy-chain mRNA levels in the HF diet-fed animals, suggesting that liver Fe accumulation occurred at least in part due to a favoured liver erythrocyte uptake. If this feeding condition was to be prolonged, impaired Fe decompartmentalisation may occur, ultimately resulting in dysmetabolic Fe overload.
Emission and transmission tomography system applied to analyze industrial process inside chemical reactors
2020 - MESQUITA, C.H.; VELO, A.F.; CALVO, W.P.; CARVALHO, D.V.; HAMADA, M.M.
The tomography techniques are widely used in many industries, such as: chemical, food, pharmaceutical and oil sectors. In the industries the tomography is used to diagnose the state of the machines of production and also in the control of quality of the produced objects. A portable tomography system known as instant-non-scanning type, a similar version of the fourth generation CT, was developed in this work. It is capable to obtain measurements in real time conditions without interrupting the operation of the industrial production and it is useful in the quality control of the means of production and the objects produced. This paper describes an innovative hybrid industrial tomographic system, i.e., simultaneous data from the emission of an internal radioactive source introduced inside to the object (67Ga citrate) and tomographic transmission using five sources of 137Cs positioned externally to the object which are distributed at the vertices of a pentagon. The tomographic system described here is useful for studying dynamic chemical phenomena, associated or not with multiphase systems commonly found in chemical reactors and distillation columns.
Influence of impurities on the radiation response of the TlBr semiconductor crystal
2017 - SANTOS, ROBINSON A. dos; MESQUITA, CARLOS H. de; SILVA, JULIO B.R. da; FERRAZ, CAUE de M.; COSTA, FABIO E. da; MARTINS, JOAO F.T.; GENNARI, ROSELI F.; HAMADA, MARGARIDA M.
Two commercially available TlBr salts were used as the rawmaterial for crystal growths to be used as radiation detectors. Previously, TlBr salts were purified once, twice, and three times by the repeated Bridgmanmethod. Thepurification efficiency was evaluated by inductively coupled plasma mass spectroscopy (ICP-MS), after each purification process. A compartmental model was proposed to fit the impurity concentration as a function of the repetition number of the Bridgman growths, as well as determine the segregation coefficients of impurities in the crystals. The crystalline structure, the stoichiometry, and the surface morphology of the crystals were evaluated, systematically, for the crystals grown with different purification numbers. To evaluate the crystal as a radiation semiconductor detector, measurements of its resistivity and gamma-ray spectroscopy were carried out, using 241Am and 133Ba sources. A significant improvement of the radiation response was observed in function of the crystal purity.
A portable tomography system with seventy detectors and five gamma-ray sources in fan beam geometry simulated by Monte Carlo method
2017 - VELO, A.F.; HAMADA, M.M.; CARVALHO, D.V.S.; MARTINS, J.F.T.; MESQUITA, C.H.
This paper describes the Monte Carlo simulation, using MCNP4C, of a portable instant non-scanning tomography containing five radioactive sources with the same activities and seventy NaI(Tl) detectors constituted of five sets of fourteen detectors, diametrically opposite to each radioactive source. The detector was validated by comparison with the experimental measurements. The full width at half maximum (FWHM) deviation between the experimental and the simulated spectra was 3.5%. A steel pipe of 17 cm×0.5 cm (diameter×thickness) containing water and two dynamic bubbles of 2 cm and 4 cm diameter were simulated. The SIRT algorithm was used to reconstruct the images. The simulated images are presented in frames. On the first frame, no bubble is observed. On the subsequent frames, the growing of the bubbles is observed, reaching the maximum diameter; after that, the bubble begins to decrease progressively, until its disappearance. The measured bubble diameters generated by simulation were 43 ± 3 mm and 27 ± 2 mm for the bubbles of 40 mm and 20 mm diameters, respectively. The spatial resolution of the proposed simulated tomography was estimated by the Modulation Transfer Function (MTF), presenting a spatial resolution of 18.3 mm and 20.2 mm for samplings at 137Cs photopeak and full window, respectively.
Industrial tomography using three different gamma ray
2016 - MESQUITA, C.H. DE; VELO, A.F.; CARVALHO, D.V.S.; MARTINS, JOAO F.T.; HAMADA, M.M.
Expression of genes involved in porphyrin biosynthesis pathway in the human renal cell carcinoma
2015 - ROCHA FILHO, HUGO N. da; SILVA, EVELIN C. da; SILVA, FLAVIA R.O.; COURROL, LILIA C.; MESQUITA, CARLOS H. de; BELLINI, MARIA H.
Renal cell carcinoma (RCC) remains one of the greatest challenges of urological oncology and is the third leading cause of death in genitourinary cancers. Surgery may be curative when patients present with localized disease. Our previous results demonstrated the autofluorescence of blood PpIX in primary RCC mouse model and an increase in fluorescence intensity as a function of growth of the subcutaneous tumor mass. In another work, a nice correlation between the growth of the tumor mass and tissue fluorescence intensity was found. The aim of this study was to evaluate the expression profile of porphyrin biosynthesis pathway-related genes of human kidney cells. We used two kidney cell lines, one normal (HK2) and another malignant (Caki-1). Endogenous and 5-aminolevolinic acid (ALA) induced protoporphyrin IX (PpIX) HK2 and Caki-1 cells were analyzed by fluorescence spectroscopy. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to measure mRNA of those genes. Emission spectra were obtained by exciting the samples at 405 nm. For ALA untreated cells the maximum fluorescence intensity was detected at 635 nm. The mean peak area of emission spectra in both cells types increased linearly in function of cell number. Besides, basal levels of PpIX autofluorescence of each cell concentration of HK2 samples were significantly lower than those of Caki-1 samples. For ALA-treated cells the mean PpIX spectra shows PpIX emission peak at 635 nm with a shoulder at 700 nm. Analysis of PpIX fluorescence intensity ratio between tumor cells and HK2 cells showed that fluorescence intensity was, on average, 26 times greater in tumor cells than in healthy cells. qRT-PCR revealed that in Caki-1 ALA-treated cells, PEPT gene was significantly up-regulated and FECH and HO-1 genes were significantly down regulated in comparison with HK2 ALAtreated cells. In conclusion, our results demonstrate the preferential accumulation of ALA-induced PpIX in human RCC and also indicate that PEPT1, FECH and HO-1 genes are major contributors to this accumulation.