Chloride and sodium ion concentrations in saliva and sweat as a method to diagnose cystic fibrosis / Dosagem da concentração dos íons cloreto e sódio na saliva e no suor para o reconhecimento de pacientes com fibrose cística

Abstract Objective: Cystic fibrosis diagnosis is dependent on the chloride ion concentration in the sweat test (≥ 60 mEq/mL - recognized as the gold standard indicator for cystic fibrosis diagnosis). Moreover, the salivary glands express the CFTR protein in the same manner as sweat glands. Given this context, the objective was to verify the correlation of saliva chloride concentration and sweat chloride concentration, and between saliva sodium concentration and sweat sodium concentration, in patients with cystic fibrosis and healthy control subjects, as a tool for cystic fibrosis diagnosis. Methods: There were 160 subjects enrolled: 57/160 (35.70%) patients with cystic fibrosis and two known CFTR mutations and 103/160 (64.40%) healthy controls subjects. Saliva ion concentration was analyzed by ABL 835 Radiometer® equipment and, sweat chloride concentration and sweat sodium concentration, respectively, by manual titration using the mercurimetric procedure of Schales & Schales and flame photometry. Statistical analysis was performed by the chi-squared test, the Mann -Whitney test, and Spearman's correlation. Alpha = 0.05. Results: Patients with cystic fibrosis showed higher values of sweat chloride concentration, sweat sodium concentration, saliva chloride concentration, and saliva sodium concentration than healthy controls subjects (p-value < 0.001). The correlation between saliva chloride concentration and sweat chloride concentration showed a positive Spearman's Rho (correlation coefficient) = 0.475 (95% CI = 0.346 to 0.587). Also, the correlation between saliva sodium concentration and sweat sodium concentration showed a positive Spearman's Rho = 0.306 (95% CI = 0.158 to 0.440). Conclusions: Saliva chloride concentration and saliva sodium concentration are candidates to be used in cystic fibrosis diagnosis, mainly in cases where it is difficult to achieve the correct sweat amount, and/or CFTR mutation screening is difficult, and/or reference methods for sweat test are unavailable to implement or are not easily accessible by the general population.

Resumo Objetivo: O diagnóstico da fibrose cística depende do valor da concentração de íons de cloreto no teste do suor (≥ 60 mEq/mL - reconhecido como o indicador-padrão para o diagnóstico da doença). Além disso, as glândulas salivares expressam a proteína RTFC igualmente às glândulas sudoríparas. Nesse contexto, nosso objetivo foi verificar a correlação da concentração de cloreto na saliva e a concentração de cloreto no suor e entre a concentração de sódio na saliva e a concentração de sódio no suor em pacientes com fibrose cística e indivíduos controles saudáveis, como uma ferramenta para diagnóstico de fibrose cística. Métodos: Contamos com a participação de 160 indivíduos [57/160 (35,70%) com fibrose cística e duas mutações no gene RTFC conhecidas e 103/160 (64,40%) indivíduos controles saudáveis]. A concentração de íons na saliva foi analisada pelo equipamento ABL 835 da Radiometer® e a concentração de cloreto no suor e sódio no suor, respectivamente, por titulação manual utilizando o método mercurimétrico de Schales & Schales e fotometria de chama. A análise estatística foi realizada pelo teste qui-quadrado, pelo teste de Mann-Whitney e pela correlação de Spearman. Alpha = 0,05. Resultados: Os pacientes com fibrose cística apresentaram maiores valores na concentração de cloreto no suor, concentração de sódio no suor, concentração de cloreto na saliva e concentração de sódio na saliva do que os indivíduos-controle saudáveis (valor de p < 0,001). A correlação entre as concentrações de cloreto na saliva e cloreto no suor mostrou Rho de Spearman (coeficiente de correlação) positivo = 0,475 (IC de 95% = 0,346 a 0,587). Além disso, a correlação entre concentração de sódio na saliva e concentração de sódio no suor mostrou Rho de Spearman positivo = 0,306 (IC de 95% = 0,158 a 0,440). Conclusões: A concentração de cloreto na saliva e a concentração de sódio na saliva são candidatas a ser usadas como diagnóstico de fibrose cística, principalmente em casos em que é difícil atingir a quantidade correta de suor, e/ou o exame da mutação RTFC é difícil e/ou o método de referência para o teste do suor não se encontra disponível ou não é de fácil acesso ao público em geral.

Concentration changes of electrolytes in vitreous humor of acidosis associated with different postmortem interval in rabbits / 重庆医科大学学报

Objective:To investigate the chemical composition changes in vitreous humor of rabbits at different times after the death of acute acidosis. Methods: 30% Sodium Dihydrogen Phosphate were used in rabbits to induce the animal model of acute acidosis,and we observed the ionic concentration changes in vitreous humor at different times. Results:72 hours after the death of acute acidosis,the concentration of Potassium,Magnesium,Phosphorus in vitreous humor were gradually increased and Calcium were decreased gradually with the time of death. Sodium performance instability,the change of chlorinity firstly decreased and then increased.Potassium ions was closely related to death time (R2=0.976 1). Conclusion:After the death of acute acidosis,the concentration of Potassium in the vitreous humor of rabbits can be used to infer PMI in the death of acute acidosis.

Preparative Method of CRRT Displacement Liquid / 中国药房

OBJECTIVE:To investigate the feasibility and accuracy of the current preparative method of CRRT displacement liquid in hospital preparation manufacturing laboratory.METHODS:The electrolytes in 8 CRRT displacement liquid samples were determined and the RSD values were calculated by comparison with theoretic value;the effects of ionic concentration and volume of raw material on the preparing results as well as the RSD of volume error were investigated.RESULTS:The RSD between theoretical and practical ionic concentrations was lower than 4.14%.The maximum change of ionic concentration caused by concentration of solution was 5.32 mmol?L-1;The maximum volume change caused by volume loading was 62 mL and the displacement liquid ionic concentration lower than theoretical value was 0.4 mmol?L-1.The RSD of volume difference was 2.46%.CONCLUSION:The preparing results of CRRT displacement liquid by the preparative method adopted in our hospital can meet the clinical standard on this preparation.

Concentration of K~+ and Mg~(2+) in vitreous humor taken by alternative micro-sampling method from both eyes of rabbits for the estimation of postmortem interval / 中国法医学杂志

72h), the average deviations are over 15 hours. The average deviations of Equation 2 are almost all above 10 hours. The average deviations of Equation 3 are the lowest of the three.Conclusion The [K~+] and [Mg~(2+)] in the vitreous humor rises while the PMI extends. There are correlations between the concentration of K~+ and Mg~(2+) in the vitreous humor and the PMI. For the estimation of PMI, we suggest that the equation with R2 lower than 0.98, or with high average deviations should not be used. It seems that multiple regression equation could increase the accuracy of PMI estimation.