Use of photochemical reactions in flow injection: determination of oxalate in urine

The use of photochemical reactions in flow injection (FI) is reported. The irradiation of an FI reactor with a suitable source facilitates the development of the iron(III)-oxalate reaction, allowing the amperometric determination of the anion in the range 1.0-13.0 micrograms ml-1, with a relative standard deviation of 1.1% and a sampling frequency of 40 h-1. The proposed method was applied successfully to the determination of oxalate in urine samples.

Bone marrow biopsy in myelodysplastic syndromes: morphological characteristics and contribution to the study of prognostic factors

Ten characteristics of bone marrow (BM) biopsies in paraffin sections, obtained at diagnosis from patients with myelodysplastic syndromes (MDS) classified according to the FAB criteria, were analysed to identify both the most relevant morphologic data and any possible influence on survival. Agreement between two observers was obtained for 94% of the data. BM cellularity was increased in 63% of the cases and was higher in refractory anaemia with excess of blasts (RAEB). RAEB in transformation (RAEB-t) and chronic myelomonocytic leukaemia (CMML) (P = 0.001). Dysmegakaryopoiesis and dyserythropoiesis were present respectively in 83% and 72% of the cases, with slight differences among the FAB subtypes. Abnormal localization of immature precursors (ALIP) was found in more than half of the cases and somewhat more frequently seen in the RAEB + RAEB-t + CMML group (P = 0.07). Eosinophilia, plasmacytosis and reticulin fibrosis were evident in 26%, 18% and 47% of the cases respectively. Cellularity (P = 0.006), eosinophilia (P = 0.009) and, to some extent, dysmegakaryopoiesis (P = 0.07) bore a certain relationship with survival on univariate analysis. The presence of ALIP was not seen to affect the outcome. Multivariate analysis showed that the cellularity and presence of dysmegakaryopoiesis, in BM biopsy, added significant independent prognostic information to that achieved with age, platelet count and proportion of blast cells in BM aspirate, three variables with proven prognostic value in MDS patients. Using a regression model including these five characteristics we have stratified the patients into low, intermediate and high-risk groups with different survivals (P = 0.00001). The present findings show that BM biopsy is able to provide both morphological characteristics and information about the prognosis of survival, and should thus be included in the initial evaluation of MDS.

Flow injection analysis: A new approach to pharmaceutical determinations

A review is presented in which the fundamental principles, instrumentation and practical aspects of flow injection analysis (FIA) are discussed. A particular focus is put on applications in pharmaceutical chemistry, which offers a wide scope to the new technique.

Bone marrow histologic pattern--the best single prognostic parameter in chronic lymphocytic leukemia: a multivariate survival analysis of 329 cases

In previous studies, the prognostic value of bone marrow (BM) histologic patterns in chronic lymphocytic leukemia (CLL) has been demonstrated. In order to investigate whether such a value is independent of other prognostic parameters, a multivariate survival analysis (Cox's regression model) was undertaken in a series of 329 CLL patients in whom a BM had been performed. The following binary variables were included in the analysis: age (more than 60 years), lymphadenopathy (more than two areas involved), splenomegaly, hepatomegaly, absolute lymphocyte count (more than 30,000 microL), anemia (hemoglobin less than 10 g/dL), thrombocytopenia (less than 100,000 microL), and BM pattern (diffuse v nondiffuse). Three variables entered the regression at significant level: BM pattern (P less than .001), anemia (P less than .001), and hepatomegaly (P = .03). The model was also tested by expressing the variables in a continuous way when possible. Again, BM pattern entered first in the regression (P less than .001), followed by the hepatomegaly (P = .002), hemoglobin level (P = .02), and lymphadenopathy (P = .04). When both the binary and the continuous models were tested separately in 227 patients with BM as initial staging procedure and in 102 patients in whom this was performed later during the course of the disease, in all instances, BM pattern entered first in the regression at a highly significant level. BM histologic pattern appears to be a better single prognostic parameter than any one of the variables employed in current clinical staging systems. A combined clinicopathologic system incorporating the BM pattern, together with the usual clinical variables, is presented.