Lower Vitamin D Levels, but Not VDR Polymorphisms, Influence Type 2 Diabetes Mellitus in Brazilian Population Independently of Obesity.

Background and Objectives: Vitamin D levels have been associated with a diversity of diseases, including obesity. Vitamin D presents a pleiotropic action, and can regulate insulin secretion and inflammatory responses. Vitamin D receptor (VDR) gene polymorphisms are involved in the gene expression regulation and have been associated with type 2 diabetes mellitus (T2DM). This study aimed to evaluate the association between the polymorphisms ApaI (rs7975232), BsmI (rs1544410), FokI (rs10735810), and TaqI (rs731236) in the VDR gene in people diagnosed with T2DM, and plasma 25-hydroxivitamin D levels [25(OH)D]. Materials and Methods: A total of 101 T2DM patients and 62 gender, age, and body mass index (BMI) matched non-diabetic controls were included in this study. Molecular analyzes were performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The plasma 25(OH)D levels were measured by high performance liquid chromatography. Results: The plasma 25(OH)D levels were lower in T2DM patients (17.2 (16.6) ng/mL) when compared with the control subjects (30.8 (16.2) ng/mL, p < 0.0001), independently of obesity status. We found no difference between genotypic and allelic frequencies of the VDR polymorphisms when comparing the T2DM group and control group (p > 0.05 for all), and did not show any association with plasma 25(OH)D levels. Conclusions: These results suggest that T2DM is associated with lower plasma 25(OH)D levels, which are not related to BMI and VDR gene polymorphisms.

Polymorphisms in vitamin D receptor gene, but not vitamin D levels, are associated with polycystic ovary syndrome in Brazilian women.

This study aimed to investigate the association between vitamin D (VitD) levels, polymorphisms in VDR gene (ApaI, BsmI, FokI, and TaqI) and the polycystic ovary syndrome (PCOS) in a group of Brazilian women. A total of 100 patients with PCOS and 100 control women were included. The quantification of 25-hydroxyvitamin D (25(OH)D) was performed in high-performance liquid chromatography (HPLC). Polymorphisms on VDR gene were performed by PCR-RFLP. The BsmI AG genotype was more frequent in PCOS group, while the GG genotype was more frequent in the control group (p = .007). The frequency of the Taql CC genotype was higher in PCOS group, while the CT genotype was the most frequent in the control group (p = .021). Mean serum VitD levels were similar between the groups. However, there was a negative correlation between VitD levels and Ferriman-Gallwey score (p = .031, r = -.260) in the PCOS group. The TaqI and BsmI polymorphisms were associated with PCOS. Moreover, VitD levels are associated with the clinical hyperandrogenism. The data suggest the role of VitD in PCOS development and its complications.

Plasma antimony determination during cutaneous leishmaniasis treatment with intralesional infiltration of meglumine antimoniate.

OBJECTIVES: To evaluate the antimony (Sb) in plasma of patients who underwent a standardised meglumine antimoniate (MA) intralesional infiltration protocol for cutaneous leishmaniasis treatment. METHODS: The level of Sb in plasma was determined by atomic absorption spectroscopy, before and 1, 2, 4 and 6 hours after the first intralesional infiltration of MA to determine the parameters peak concentrations (C1 h ), area under curve of drug concentration in plasma from zero to 6 h (AUC0-6 h ) and elimination half-life (t½) of Sb. Blood samples were also collected weekly during the treatment period, always before infiltration. RESULTS: Fourteen patients underwent MA intralesional infiltration with doses ranging from 0.8 to 9 mg Sb/kg at the first infiltration. The C1 h ranged from 3850 to 47 095 mg × h/L and was the highest concentration obtained for 11 of 14 patients after the first intralesional infiltration of MA. A rapid initial phase of distribution lasting up to 4 h (2.6 ± 0.34 h) was followed by a slower elimination phase. Total skin lesion area, C1 h and AUC(0-6 h) were related to the dose of Sb infiltered (P < 0.05). Plasma Sb in samples collected weekly before the infiltration revealed antimony concentrations below the quantification limit (15.0 µg Sb/l) during the treatment period. CONCLUSIONS: Sb is quickly absorbed and eliminated after intralesional administration of MA, in a pattern similar to that reported with the Sb systemic administration. Using a therapeutic schedule limited to weekly intralesional infiltration of doses <10 mg Sb/kg does not result in plasma Sb accumulation.

OxLDL plasma levels in patients with Alzheimer's disease.

OBJECTIVE: The objective of this study was to characterize the conventional lipid profile, oxLDL levels and ApoE polymorphism in patients with Alzheimer's disease (AD) and in elderly individuals without cognitive impairment. METHODS: Eighty elderly individuals were selected and the levels of oxLDL were determined using the ELISA kit, and ApoE gene polymorphism was investigated using polymerase chain reaction-restriction fragment length polymorphism. RESULTS: Significantly reduced levels of oxLDL were observed in patients with AD compared to the control group. A higher frequency of the ApoE ε4 allele was observed in patients with AD compared to controls. No difference was observed for total cholesterol, HDL-C, and LDL-C levels between the two groups, while triglyceride levels were higher in controls compared with patients with AD. CONCLUSION: The data analyzed together did not reveal significant differences in lipid profiles, including oxLDL levels. However, the importance of lipid changes in the genesis of the disease cannot be ruled out. Nevertheless, the ApoE ε4 allele was significantly more frequent in patients with Alzheimer's dementia in agreement with previous findings in the literature, but this genetic component did not change the levels of oxLDL.

OxLDL plasma levels in patients with Alzheimer's disease / Níveis plasmáticos de LDL-ox em pacientes com doença de Alzheimer

ABSTRACT Objective: The objective of this study was to characterize the conventional lipid profile, oxLDL levels and ApoE polymorphism in patients with Alzheimer's disease (AD) and in elderly individuals without cognitive impairment. Methods: Eighty elderly individuals were selected and the levels of oxLDL were determined using the ELISA kit, and ApoE gene polymorphism was investigated using polymerase chain reaction-restriction fragment length polymorphism. Results: Significantly reduced levels of oxLDL were observed in patients with AD compared to the control group. A higher frequency of the ApoE ε4 allele was observed in patients with AD compared to controls. No difference was observed for total cholesterol, HDL-C, and LDL-C levels between the two groups, while triglyceride levels were higher in controls compared with patients with AD. Conclusion: The data analyzed together did not reveal significant differences in lipid profiles, including oxLDL levels. However, the importance of lipid changes in the genesis of the disease cannot be ruled out. Nevertheless, the ApoE ε4 allele was significantly more frequent in patients with Alzheimer's dementia in agreement with previous findings in the literature, but this genetic component did not change the levels of oxLDL.

RESUMO Objetivo: O objetivo deste estudo foi caracterizar o perfil lipídico convencional, os níveis de LDL-ox e o polimorfismo da ApoE em pacientes com doença de Alzheimer (DA) e em indivíduos idosos sem comprometimento cognitivo. Métodos: Foram selecionados oitenta indivíduos idosos. Os níveis de LDL-ox foram determinados usando o kit ELISA e a investigação do polimorfismo do gene da ApoE por PCR-RFLP. Resultados: Níveis significativamente reduzidos de LDL-ox foram observados em pacientes com DA comparado ao grupo controle. Uma maior frequência do alelo ε4 da ApoE foi observada nos pacientes com DA em relação aos controles. Nenhuma diferença foi observada para os níveis de colesterol total, HDL-C e LDL-C entre os dois grupos, enquanto níveis de triglicérides foram mais altos em controles comparados aos pacientes com DA. Conclusão: Os dados analisados em conjunto não revelaram diferenças significativas no perfil lipídico, incluindo os níveis de LDL-ox. No entanto, não se pode excluir a importância de alterações lipídicas na gênese da doença. Não obstante, o alelo ε4 da ApoE foi signicativamente mais frequente nos pacientes com demência de Alzheimer em concordância com achados prévios da literatura, mas esse componente genético não interferiu nos níveis de LDL-ox.

Circulating microparticles levels are increased in patients with diabetic kidney disease: A case-control research.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is associated with chronic lowgrade inflammation. Microparticles (MPs) are extracellular microvesicles released during apoptosis and cellular activation. The MP's pro-coagulant and pro-inflammatory activities are involved in endothelial dysfunction observed in T2DM patients. This study aimed to evaluate the circulating MPs profile in T2DM patients with diabetic kidney disease (DKD) and correlate it with clinical and laboratorial parameters. METHODS: MPs derived from platelets (PMPs), leukocytes (LMPs), endothelial cells (EMPs), and expressing tissue factor (TFMPs) were measured by flow cytometry, in plasma of 39 DKD patients and 30 non-diabetic controls. RESULTS: We observed higher PMPs, LMPs, EMPs, and TFMPs (all p<0.0001) levels in case group as compared to controls. For patients with DKD, circulating MPs levels were influenced by gender, but not by obesity status nor by T2DM onset. Fasting glucose and 25-hydroxyvitamin D levels showed correlation with circulating MPs levels in both groups. CONCLUSIONS: These results suggest that type 2 diabetes mellitus patients with DKD presented higher circulating MPs levels - PMPs, LMPs, EMPs, and TFMPs - which correlated with metabolic alterations.

An efficient analytical method for determination of S-phenylmercapturic acid in urine by HPLC fluorimetric detector to assessing benzene exposure.

Benzene is an important occupational and environmental contaminant, naturally present in petroleum and as by-product in the steel industry. Toxicological studies showed pronounced myelotoxic action, causing leukemic and others blood cells disorders. Assessing of benzene exposure is performed by biomarkers as trans, trans-muconic acid (AttM) and S-phenylmercapturic acid (S-PMA) in urine. Due to specificity of S-PMA, this biomarker has been proposed to asses lower levels of benzene in air. The aim of this study was to validate an analytical method for the quantification of S-PMA by High-Performance Liquid Chromatography with fluorometric detector. The development of an analytical method of S-PMA in urine was carried out by solid phase extraction (SPE) using C-18 phase. The eluated were submitted to water bath at 75°C and nitrogen to analyte concentration, followed by alkaline hydrolysis and derivatization with monobromobimane. The chromatography conditions were reverse phase C-18 column (240mm, 4mm and 5µm) at 35°C; acetonitrile and 0.5% acetic acid (50:50) as mobile phase with a flow of 0.8mL/min. The limits of detection and quantification were 0.22µg/L and 0.68µg/L, respectively. The linearity was verified by simple linear regression, and the method exhibited good linearity in the range of 10-100µg/L. There was no matrix effect for S-PMA using concentrations of 40, 60, 80 and 100µg/L. The intra- and interassay precision showed coefficient of variation of less than 10% and the recovery ranged from 83.4 to 102.8% with an average of 94.4%. The stability of S-PMA in urine stored at -20°C was of seven weeks. The conclusion is that this method presents satisfactory results per their figures of merit. This proposed method for determining urinary S-PMA showed adequate sensitivity for assessment of occupational and environmental exposure to benzene using S-PMA as biomarker of exposure.

Intestinal toxicity evaluation of long-circulating and pH-sensitive liposomes loaded with cisplatin.

Cisplatin (CDDP) is a chemotherapeutic agent widely used in several anticancer protocols for instance head and neck, testicle, ovarian, lung and peritoneal carcinomatosis. According to the literature, the use of CDDP is associated with several side effects; among them, we highlighted the mucositis. CDDP, when administered by IP, promoted significant intestinal epithelium alterations in an experimental model. Our research group has proposed that the incorporation of CDDP into long-circulating and pH-sensitive liposomes (SpHL-CDDP) could help to overcome some side effects induced by this drug. Thus, we evaluated signs of intestinal toxicity 24h and 72h after the administration of a single i.p dose of free CDDP or SpHL-CDDP to healthy Swiss mice. Twenty-four hours after administration of free CDDP, the mice showed signs of intestinal toxicity, principally weight loss, increased intestinal permeability associated with a decrease in expression of tight junctions, and histological damage with the presence of inflammatory infiltrates and activation of ERK1/2 and NF-κB. These changes persisted after 72h. While signs of intestinal toxicity were also observed 24h after administration of SpHL-CDDP, after 72h body weight and intestinal permeability of mice in this group were similar to those of mice in the control group. In comparison with the free CDDP treatment group, 72h after treatment mice in the SpHL-CDDP group showed better histological parameters, lower levels of inflammatory infiltrate with increased IL-10 and IgA levels, and less activation of caspase-3, ERK1/2 and NF-κB. These differences could account for the recovery of the intestinal epithelium observed in mice treated with SpHL-CDDP but not in mice treated with free CDDP. In conclusion, here we show that encapsulation of CDDP in SpHL lessens intestinal damage and that, as such, SpHL-CDDP is a promising candidate for clinical use.

Homocysteine: validation and comparison of two methods using samples from patients with pulmonary hypertension / Homocisteína: validação e comparação entre dois métodos utilizando amostras de pacientes com hipertensão pulmonar

Introduction and objective: The determination of homocysteine plasma levels has been reported as a risk marker of interest in severe diseases involving endothelial injury and associated with the development or progression of atherosclerotic lesions and thrombus formation. The aims of this study were to validate method for quantification of plasma homocysteine by high performance liquid chromatography (HPLC) with fluorimetric detection, and to compare the results obtained from patients with pulmonary hypertension by HPLC with those obtained by spectrophotometric enzymatic cycling (S-Ec) method. Materials and methods: The validation parameters, such as linearity, matrix effect, precision, accuracy, detection and quantitation limits, and robustness of the method were evaluated aiming to demonstrate that it is suitable for the intended use. The data obtained in the quantification of homocysteine using the validated method (HPLC) and the spectrophotometric enzymatic cycling (S-Ec) method, were compared. Results: The method was precise, accurate, and robust; it also had good recovery and showed no matrix effect. The linearity covered a range of 5.0-85.0 µmol/l and the limits of detection and quantification were 1.0 µmol/l and 3.4 µmol/l, respectively. The results obtained for homocysteine determination by HPLC and S-Ec methods were comparable. Conclusion: The validated HPLC method showed good performance for quantification of plasma homocysteine levels, while S-Ec method provided results for homocysteine comparable with those obtained by the validated method; therefore, this methodology is a potential alternative of automated method for clinical laboratories. .

Introdução e objetivo: A determinação dos níveis plasmáticos de homocisteína tem sido relatada como um marcador de risco de interesse em doenças graves que cursam com lesões endoteliais, estando associada ao desenvolvimento ou à progressão de lesões ateroscleróticas e formação de trombos. Os objetivos do presente estudo compreenderam validar o método de dosagem de homocisteína plasmática por cromatografia líquida de alta eficiência (CLAE) com detecção fluorimétrica, analisar amostras de pacientes com hipertensão pulmonar e comparar os resultados obtidos por CLAE com aqueles obtidos com a metodologia espectrofotométrica enzimática cíclica (E-Ec). Materiais e métodos: Os parâmetros de validação linearidade, efeito de matriz, precisão, exatidão, limites de detecção e quantificação, além de robustez do método foram avaliados visando demonstrar que este está apropriado para o uso pretendido. Os dados obtidos na quantificação de homocisteína pelo método validado (CLAE) e pela metodologia espectrofotométrica enzimática cíclica (kit da Labtest) foram comparados. Resultados: O método mostrou-se preciso, exato, robusto, com boa recuperação e não apresentou efeito de matriz. A linearidade abrangeu a faixa de 5 a 85 µmol/l, e os limites de detecção e quantificação foram 1 µmol/l e 3,4 µmol/l, respectivamente. Quanto à comparação dos resultados da determinação de homocisteína por CLAE e por E-Ec, eles foram comparáveis. Conclusão: O método validado por CLAE apresentou desempenho adequado para mensuração dos níveis plasmáticos de homocisteína, enquanto o uso da metodologia E-Ec forneceu resultados para homocisteína comparáveis com aqueles obtidos pelo método validado, sendo esta metodologia uma opção de método automatizado para laboratórios clínicos. .

Action of a pancreatin and an Aspergillus oryzae protease on whey proteins: correlation among the methods of analysis of the enzymatic hydrolysates

The objectives of this study were to hydrolyze whey proteins using a pancreatin and an Aspergillus oryzae protease; to evaluate the degree of hydrolysis (DH) and the peptide profile; and to establish the correlations among the analytical methods. Ten hydrolysates were prepared at different reaction times and the highest DH was obtained by the protein content method. Good correlations (r > 0.87) between the methods of formaldehyde and orthophthalaldehyde (OPA), formaldehyde and osmometry as well as osmometry and OPA were observed using pancreatin. Similar results were obtained between OPA and soluble protein content for the A. oryzae protease. The action of pancreatin produced the highest contents of di- and tripeptides (9.07, 7.12 and 6.46%) and the lowest of large peptides (42.43, 41.33 and 41.13%), after 3, 4 and 5 h of hydrolysis, respectively. Using pancreatin, the DH measured by formol titration and OPA was positively correlated with medium peptide content and negatively correlated with large peptide content. For the A. oryzae protease, a strong negative correlation was observed between the large peptide content and the DH measured by the OPA method.

Investigation of alternative organic solvents and methods for the preparation of long-circulating and pH-sensitive liposomes containing cisplatin.

Recent studies using long-circulating and pH-sensitive liposomes containing cisplatin (SpHL-CDDP) have resulted in a formulation with improved pharmacokinetic, toxicity and tumor localization properties. In this study, SpHL-CDDP were prepared in both laboratory and pilot scales. This study evaluated the possibility of using the dehydration-rehydration method, as well as using alternative organic solvents (ethyl acetate/ethanol mixtures at 2:1 and 1:1 volume ratios), for the preparation of liposomes by the reverse-phase evaporation (REV) method. The influence of different concentrations of cisplatin (CDDP) (2.0, 1.0, 0.5 and 0.25 mg/mL) on the entrapment percentage and size of SpHL-CDDP was also investigated. In addition, carbohydrates were tested as cryoprotectants in a freeze-thaw study as a pretest to screen the type to be used in the freeze-drying process. A decrease in the encapsulation percentage of CDDP and an increase in the vesicle diameter could be observed for both liposome formulations prepared with ethyl acetate:ethanol mixtures, as compared with REV liposomes prepared with ethyl ether. It is important to note that after applying either quick or slow cooling, the mean diameter of SpHL (empty liposomes) proved to be similar when in the presence of cryoprotectants. In sum, the optimal processing conditions were achieved when using a 0.5 mg/mL CDDP solution, ethyl ether and the REV method, resulting in liposomal dispersions of mean diameters and homogeneities that were deemed suitable for intravenous administration.

Aterotrombose e antiagregantes plaquetários / Atherothrombosis and antiplatelet drugs

A aterotrombose é uma doença do sistema circulatório cujas manifestações clínicas mais significativas (infarto do miocárdio e acidente vascular encefálico) representam atualmente as principais causas de mortalidade, com expectativa de que sua incidência aumente nos próximos anos. O uso clínico de antiagregantes plaquetários encontra-se firmemente consolidado como terapia de escolha na prevenção primária e secundária de eventos clínicos relacionados à aterotrombose. A presente revisão tem como objetivo realizar uma descrição dos aspectos gerais da aterotrombose e dos principais fármacos antiagregantes plaquetários, com uma descrição breve de seus aspectos farmacodinâmicos e farmacocinéticos.

Atherothrombosis is a circulatory system disease whose most significant clinical manifestations (myocardial infarction and stroke) are today the leading causes of death worldwide, expected to increase over the coming years. The clinical use of antiplatelet agents is firmly established as the therapy of choice in primary and secondary prevention of clinical events related to atherothrombosis. This review offers a description of the general aspects of atherothrombosis and the main antiplatelet drugs,with a brief outline of their pharmacodynamic and pharmacokinetic aspects.

Multivariate approach in the optimization procedures for the direct determination of manganese in serum samples by graphite furnace atomic absorption spectrometry.

A method for direct determination of manganese (Mn) in human serum by graphite furnace atomic absorption spectrometry (GFAAS) was proposed in this work. The samples were only diluted 1:4 with nitric acid 1% (v/v) and Triton(®) X-100 0.1% (v/v). The optimization of the instrumental conditions was made using multivariate approach. A factorial design (2(3)) was employed to investigate the tendency of the most intense absorbance signal. The pyrolysis and atomization temperatures and the use of modifier were available and only the parameter modifier use did not have a significant effect on the response. A Center Composed Design (CCD) presented best temperatures of 430 °C and 2568 °C for pyrolysis and atomization, respectively. The method allowed the determination of manganese with a curve varying from 0.7 to 3.3 µg/L. Recovery studies in three concentration levels (n=7 for each level) presented results from 98 ± 5 to 102 ± 7 %. The detection limit was 0.2 µg/L, the quantifying limit was 0.7 µg/L, and the characteristic mass, 1.3 ± 0.2 pg. Intra- and interassay studies showed coefficients of variation of 4.7-7.0% (n=21) and 6-8%(n=63), respectively. The method was applied for the determination of manganese in 53 samples obtaining concentrations from 3.9 to 13.7 µg/L.

Determination of manganese in urine and whole blood samples by electrothermal atomic absorption spectrometry: comparison of chemical modifiers.

In this work, methodologies to determine manganese (Mn) in urine and whole blood by electrothermal atomic absorption spectrometry were developed. The use of Ru, Rh, and Zr as permanent modifiers, Pd as a modifier in solution, and the condition without modifier were investigated for the direct determination of Mn in urine and whole blood samples. The best results for Mn in urine and in whole blood were obtained without modifier use. The analytical characteristic, such as accuracy, precision and limit of detection of the proposed methodology were adequate.

Determinação simultânea dos ácidos hipúrico metil-hipúrico urinários por métodos cromatográficos: comparação entre cromatografia líquida de alta eficiência e cromatografia gasosa capilar / Simultaneous determination of urinary hyppuric and methylhyppuric acids through chromatographic methods: comparation between high performance liquid chromatography and capilary gas chromatography

O presente trabalho foi realizado objetivando-se comparar a eficiência de dois métodos analíticos, um por cromatografia líquida de alta eficiência (CLAE) e outro por cromatografia em fase gasosa com coluna capilar (CG), na determinação conjunta do ácido hipúrico (AH) e ácido metil-hipúrico (AMH) em urina de indivíduos expostos ocupacionalmente ao tolueno e xileno. Após a validação analítica foi observado que o método CLAE apresentou melhores precisão intra e interensaio, porcentagem de recuperação e sensibilidade. Amostras de urina de trabalhadores expostos aos dois solventes em fábrica de tintas-latex foram analisadas pelos dois métodos validados e os resultados avaliados estatisticamente...

Influência da hidrólise ácida na quantificação de 2, 5-hexanodiona em urina de indivíduos expostos ocupacionalmente ao n-hexano / Influence of acid hydrolysis in 2, 5-hexanedione quantification from the urine of individuals occupationally exposed to n-hexane

A 2,5-hexanodiona (2,5-HD) urinária tem sido o biomarcador mais utilizado no monitoramento da exposição ocupacional ao n-hexano. Vários autores relatam alterações nos níveis urinários do metabólito em função do tipo de tratamento aplicado à amostra. A legislação brasileira estabelece que a determinação da 2,5-HD urinária seja realizada por cromatografia gasosa (CG), mas não faz referência ao preparo das amostras para a análise. Com o objetivo de estudar a influência da hidrólise ácida no resultado das determinações de 2,5-HD, amostras de urina de indivíduos expostos e não-expostos ao n-hexano, foram analisadas por cromatografia em fase gasosa utilizando-se duas técnicas, respectivamente, com e sem hidrólise ácida...

Estabilidade química de alguns indicadores biológicos em amostra de urina / Chemical stability of some biological indicators in urine samples

Um dos fatores mais importantes no controle de qualidade de um laboratório de análise toxicológicas é a adequada conservaçäo e armazenamento do agente a ser analisado. O laboratório de Toxicologia da FAFAR/UFMG, ao integrar a Rede Nacional do INAMPS, preocupou-se em estudar e estabelecer o período de estabilidade química de alguns fármacos, de modo a esclarecer, adequadamente, os usuários do laboratório quanto ao tempo máximo aceitável entre a coleta e o envio da amostra ao laboratório, assim como os cuidados necessários para o seu transporte. Forma selecionados inicialmente para o trabalho o ácido tricloroacético, o ácido delta aminolevulinico e o fenol. Os dois primeiros analisados por expectrofotometria e o último por cromatografia gasosa. Os compostos mostraram-se estáveis o suficiente para, quando armazenados nas condiçöes do trabalho, serem manuseados mesmo após sete dias da coleta.

Validade de correçäo de valores de ALA-U através da densidade urinária e da concentraçäo de creatinina / Confirmation of U-ALA results through the urinary density and the creatinine content

A determinaçäo do ácido delta aminolevulínico urinário (ALA-U é um dos Indices Biológicos de Exposiçäo (IBE) mais utilizados no controle biológico da exposiçäo ocupacional ao chumbo. O ALA é geralmente determinado na urina colhida ao final da jornada de trabalho, e as variaçöes decorrentes do fluxo urinário säo corrigidas através da concentraçäo de creatinina ou da densidade urinária . O presente trabalho faz um estudo estatístico de 223 resultados de ALA-U obtidos mno Laboratório de Análises Toxicológicas da Faculdade da Faculdade de Fármacia da UFMG, procurando avaliar a validade dessas correçöes. Os resultados demonstram que näo existe diferença significativa entre os valores näo corrigidos e os corrigidos pela densidade, tornando-se desnecessária a utilizaçäo deste parâmetro como fator de correçäo das variaçöes do fluxo urinário

Otimizaçäo das condiçöes analíticas para a determinaçäo espectrofotométrica de àcido delta-aminolevulínico urinário (ALA-U) / Optimization of the analytical conditions for the spectrophotometric determination of urinary-aminolevulinic acid (U-ALA)

Procurando otimizar as condiçöes analíticas da determinaçäo de ALA-U, pelo método de TOMOKUNI & OGATA (1972)1, foi idealizado o presente trabalho. Apesar de o método analítico ser simples e fácil, algumas de suas etapas podem resultar em erros na concentraçäo de ALA-U. Assim, a possível perda ou contaminaçäo durante a fase de ciclizaçäo e de separaçäo do ALA, o papel do intervalo de tempo entre a formaçäo do produto colorido e a leitura espectro fotométrica e a importância da utilizaçäo do espectrofotômetro de duplo feixe na leitura das absorvância foram testadas e discutidas no presente trabalho