BCG vaccination policies in Mexico]

The authors report a 110 cervical cerclage operations for cervical incompetence. Shirodkar's technique was used and cerclage was carried out between the 9th and 20th week of amenorrhea. Out of 110 patients submitted to the procedure, 98 gave birth to a live infant weighing more than 1000 g which amounts to a success rate of 89%. Duration of pregnancy ranged between 26 and 41 weeks. If only pregnancies having proceeded to 37 weeks of amenorrhea are considered, the success rate amounts to 68%.     

Excision of products of oxidative DNA base damage by human NTH1 protein

A functional human homologue of Escherichia coli endonuclease III (Nth-Eco protein) has recently been cloned and characterized [Aspinwall, R., Rothwell, D. G., Roldan-Arjona, T., Anselmino, C., Ward, C. J., Cheadle, J. P., Sampson, J. R., Lindahl, T., Harris, P. C., and Hickson, I. D. (1997) Proc. Natl. Acad. Sci. U.S.A., 94, 109-114]. This enzyme, designated hNTH1 protein, shares an extensive sequence similarity with Nth-Eco protein and a related enzyme from Schizosaccharomyces pombe (Nth-Spo protein). We investigated the substrate specificity of this human enzyme for oxidative DNA base damage, using the technique of gas chromatography/isotope-dilution mass spectrometry. Four different DNA substrates damaged by various free radical-generating systems were used. 5-Hydroxycytosine, thymine glycol, 5-hydroxy-6-hydrothymine, 5,6-dihydroxycytosine, and 5-hydroxyuracil were substrates of hNTH1 protein among 17 lesions found in DNA substrates. The substrate specificity and excision kinetics of the human enzyme were found to be significantly different from those of Nth-Spo and Nth-Eco proteins.     

Solid-phase extraction of Mn(II), Co(II), Ni(II), Cu(II), Cd(II) and Pb(II) ions from environmental samples by flame atomic absorption spectrometry (FAAS)

A new method using a column packed with Amberlite XAD-2010 resin as a solid-phase extractant has been developed for the multi-element preconcentration of Mn(II), Co(II), Ni(II), Cu(II), Cd(II), and Pb(II) ions based on their complex formation with the sodium diethyldithiocarbamate (Na-DDTC) prior to flame atomic absorption spectrometric (FAAS) determinations. Metal complexes sorbed on the resin were eluted by 1 mol L(-1) HNO3 in acetone. Effects of the analytical conditions over the preconcentration yields of the metal ions, such as pH, quantity of Na-DDTC, eluent type, sample volume and flow rate, foreign ions etc. have been investigated. The limits of detection (LOD) of the analytes were found in the range 0.08-0.26 microg L(-1). The method was validated by analyzing three certified reference materials. The method has been applied for the determination of trace elements in some environmental samples.     

Lipoprotein composition in the insulin-deficient non-acidotic phase of type I diabetic patients and early evolution after the start of insulin therapy

Lipoproteins, including intermediate density lipoproteins and lipoprotein(a), and apolipoproteins A-I, B, C-II, C-III and E, were studied in 13 newly-diagnosed type I diabetic patients with severe insulinopenia without dehydration or acidosis. At baseline, the main finding was a significant increase in serum triglycerides due to raised triglyceride concentrations in all lipoproteins, particularly triglyceride-rich lipoproteins. Cholesterol concentrations were slightly increased in lipoproteins and led to a significant increase in serum cholesterol. Two days after the start of insulin therapy, lipoprotein profiles had normalized except for the LDL triglyceride contents, which remained significantly increased on the fifth day of treatment. No significant modifications were observed in lipoprotein(a), apolipoproteins A-I and E concentrations throughout the study. However, serum apolipoproteins B, C-II and C-III were increased at baseline and fell to normal levels 2 days after the start of insulin therapy. On the other hand, apolipoprotein C-II/C-III ratios in high and very low density lipoprotein, showed no significant differences at baseline compared with controls, suggesting that an apolipoprotein C-II deficiency or apolipoproteins Cs imbalance can be ruled out. In conclusion, significant lipoprotein abnormalities were observed in the insulin-deficient state of type I diabetes mellitus; insulin therapy normalizes the lipoprotein profile in two days, except for low density lipoprotein triglyceride contents which remain increased at the fifth day.     

Apolipoprotein(a) genetic polymorphism and serum lipoprotein(a) concentration in patients with peripheral vascular disease

Serum lipoprotein(a) (Lp(a)) levels were measured in 89 men with peripheral vascular disease (PVD) and 129 (100 male and 29 woman) healthy controls. Apolipoprotein(a) genetic polymorphism was determined by immunoblotting in all subjects. Patients with PVD had significantly higher serum Lp(a) levels than controls. Apolipoprotein(a) phenotype frequencies in patients with PVD did not differ from those of the control group. Both patients and controls with phenotype S2 had higher serum Lp(a) levels than those with phenotype S4. It should be emphasized that serum Lp(a) levels were significantly higher in PVD patients than controls for those with phenotype S2, S3/S4 and S4. Raised serum Lp(a) levels together with other lipoprotein abnormalities in patients with PVD imply a high cardiovascular risk. Genetic polymorphism clearly influences serum Lp(a) levels both in patients and controls. In patients with PVD, environmental and/or other genetic factors must play a role in raising Lp(a) levels.     

A neural network-based approach for calculating dissolved oxygen profiles in reservoirs

A Neural Network (NN) modelling approach has been shown to be successful in calculating pseudo steady state time and space dependent Dissolved Oxygen (DO) concentrations in three separate reservoirs with different characteristics using limited number of input variables. The Levenberg–Marquardt algorithm was adopted during training. Pre-processing before training and post processing after simulation steps were the treatments applied to raw data and predictions respectively. Generalisation was improved and over-fitting problems were eliminated: Early stopping method was applied for improving generalisation. The correlation coefficients between neural network estimates and field measurements were as high as 0.98 for two of the reservoirs with experiments that involve double layer neural network structure with 30 neurons within each hidden layer. A simple one layer neural network structure with 11 neurons has yielded comparable and satisfactorily high correlation coefficients for complete data set, and training, validation and test sets of the third reservoir.     

Enhancement of intramammary lymph nodes with lymphoid hyperplasia: a potential pitfall in breast MRI

We present three cases of breast lesions labeled as probable intramammary lymph nodes that showed an increase in size on follow-up mammography. Contrast-enhanced MRI was performed and the three lesions showed strong and rapid uptake of the intravenous contrast. Core needle biopsy established the diagnosis of lymphoid hyperplasia in all three patients. Because intramammary lymph nodes affected by benign processes can present findings similar to malignant lesions, the usefulness of contrast-enhanced MRI in these cases is controversial.