Successful ablation of atrioventricular nodal reentry tachycardia in a patient with persistent left superior vena cava

We report the case of a patient with atrioventricular nodal reentry tachycardia associated with persistent left superior vena cava draining to a large coronary sinus. Successful ablation was performed at the level of the superior lip of the coronary sinus ostium.     

Comparative modeling of substrate binding in the S1' subsite of serine carboxypeptidases from yeast, wheat, and human

Human cathepsin A ("lysosomal protective protein"; E.C.3.4.16.5) is a multifunctional lysosomal protein which forms a high-molecular-weight complex with beta-galactosidase and alpha-neuraminidase, protecting them against intralysosomal proteolysis. In addition to this protective function, cathepsin A is a serine carboxypeptidase and the understanding of its catalytic function requires a definition of its substrate specificity. For this purpose, we used a combined experimental [Pshezhetsky, A. V., Vinogradova, M. V., Elsliger, M.-A., El-Zein, F., Svedas, V.K., & Potier, M. (1995) Anal. Biochem. 230, 303-307] and theoretical approach comparing cathepsin A to two different homologous carboxypeptidases of the same family: yeast carboxypeptidase Y and wheat carboxypeptidase II. We computed the energies involved in substrate binding to the S1' subsite (C-terminal) of cathepsin A using a structural model based on the X-ray structure of the homologous wheat carboxypeptidase II. The binding energies of N-blocked Phe-Xaa dipeptide substrates to the active sites of cathepsin A, wheat carboxypeptidase II, and yeast carboxypeptidase Y were estimated using a molecular mechanics force field supplemented with a solvation energy term. This theoretical analysis showed a good correlation with the experimentally determined free energies of substrate binding. This result validates the use of this approach to analyze the energetics of substrate binding to the S1' subsite and provides a rational interpretation of serine carboxypeptidase-substrate interactions in molecular terms. We conclude that the three serine carboxypeptidases have similar affinities for substrates with hydrophobic P1' amino acid residues but that the wheat enzyme has an additional capacity for binding positively charged P1' residues. Finally, the substrate specificity of human cathepsin A is very similar to that of carboxypeptidase Y, with a high binding affinity for substrates with hydrophobic P1' residues, but the affinity of cathepsin A for P1; Phe residue is higher than for the Leu residue.     

Detecting feigned depression and schizophrenia on the MMPI-2

Increasingly, investigations evaluating the effectiveness of the MMPI-2 in the assessment of malingering employ methodologies whereby research participants are asked to feigned specific disorders rather than just to "fake bad." Yet there is little research addressing the issue of whether different validity scales and indicators work differently in the detection of different feigned disorders. In this study the comparative effectiveness of a number of validity scales and indicators on the MMPI-2 to assess feigned depression and feigned schizophrenia were evaluated. Overall, the validity scales and indicators were better at detecting feigned schizophrenia than they were in detecting feigned depression, attributable, most likely, to closer familiarity with depressive experiences. The validity scales F, Fb, and F(p) best distinguish patients with schizophrenia from participants feigning schizophrenia, and F and Fb best distinguish patients with depression from participants feigning depression.     

Direct and residual effect of fertilizer zinc application on the yield and chemical composition of rice-wheat crops in an alkali soil

A field experiment was conducted on an alkali soil to evaluate the direct and the residual effect of six levels of zinc i.e. 0, 2.25, 4.5, 9.0, 18.0 and 27.0 kg Zn ha^–1 added either once to the first crop only or continuously to each crop on the growth, yield and chemical composition of plants grown in a rice-wheat cropping sequence. The soils were amended with gypsum applied at the uniform rate of 14 t ha^–1. Zinc was supplied as zinc sulphate. Application of zinc at the rate of 2.25 kg ha^–1 to both rice and wheat crops or an annual application of 4.5 kg Zn ha^–1 only to rice was found optimum for rice-wheat sequence. Higher zinc applications increased the availability of zinc in the soil and its content in the plants but did not increase crop yield. DTPA extractable zinc build up was more for zinc applied at the rate of 2.25 kg ha^–1 to each crop compared to a single zinc application of equivalent amount. Results of these studies have shown that continuous Zn application up to 27 kg Zn ha^–1 to each crop did not induce nutrient imbalances and had no adverse effect on crop yield.     

Modeling the cost-effectiveness of granulocyte colony-stimulating factor use in early-stage breast cancer

PURPOSE: To model the cost-effectiveness (CE) of granulocyte colony-stimulating factor (G-CSF) in early-stage breast cancer when its use is directed to those most in need of the medication. METHODS: A conditional CE model was developed for the use of G-CSF based on a ranking of patient need as determined by patient blood counts during the first cycle of chemotherapy. In the base case, no G-CSF was used. In the alternative case, G-CSF was used in the following manner. If the risk of a neutropenic event (as defined by a predictive model based on nadir absolute neutrophil count [ANC] and hemoglobin decrease in cycle 1) was equal to or exceeded a predetermined critical value "T," then patients would receive G-CSF in cycles 2 through 6 of chemotherapy. If the risk of an event was less than T, patients would not use G-CSF unless an event occurred, at which time G-CSF would be administered with every subsequent cycle. RESULTS: A decision rule (T) that would allow the most needy 50% of early-stage breast cancer patients to receive G-CSF after the first cycle of chemotherapy resulted in a CE ratio of $34,297 dollars per life-year saved (LYS). If only the most needy 10% of patients received G-CSF, then the associated CE ratio was $23,748/LYS; if 90% of patients could receive the medication, the CE ratio would be $76,487/LYS. These estimates were relatively insensitive to inpatient hospital cost estimates (inpatient costs for fever and neutropenia of $3,090 to $7,726 per admission produced dollar per LYS figures of $34,297 to $32,415, respectively). However, the model was sensitive to assumptions about the shape of the relationship between dose reduction and disease-free survival (DFS) at 3 years. CONCLUSION: Providing G-CSF to the neediest 50% of early-stage breast cancer patients (as defined by first-cycle blood counts) starting after the first cycle of chemotherapy is associated with a CE ratio of $34,297/LYS, which is well in the range of CE ratios for treatment of other common medical conditions. Furthermore, conditional CE studies, based on predictive models that incorporate individual patient risk, allow one to define populations for which therapy is, or is not, cost-effective. Limitations of our present understanding of the shape of the chemotherapy dose-response curve, especially at low levels of dose reductions, affect these results. Further work is required to define the shape of the dose-response curve in early-stage breast cancer.     

1996 Peritoneal Dialysis Core Indicators Study: report on nutritional indicators

BACKGROUND: The duration of breast feeding has not yet been thoroughly described in France. A prospective survey has been performed on 150 breast feeding mothers to determine its duration. The objective of this study was to analyse predicting factors of this duration. METHODS: A questionnaire including sociological, psychological and medical variables was completed by the mothers and fathers. After discharge, the mothers were contacted every month by a physician until the completion of weaning. RESULTS: The median duration was 10 weeks. By univariate analysis, several variables were associated with a longer duration: decision to breast feed before pregnancy (12 weeks vs 9 weeks; P < 0.01), multiparity (17 weeks vs 12 weeks, P < 0.05), high paternal social level (14 weeks vs 9 weeks, P < 0.001), high maternal education level (12 weeks vs 9 weeks; P < 0.05), mother's idea of "bad" milk (9 weeks vs 30 weeks; P < 10(-6), satisfied mothers (11 weeks vs 2 weeks; P < 0.001), motivation to breast feed (P < 0.05), baby and mother in the same room during the night (13 weeks vs 10 weeks; P < 0.05), and formula supplementation (6 weeks vs 13 weeks; P < 0.01). The mother's return to work was related to a decline in the breast feeding rate at 12 weeks, yet working women generally breast fed the most frequently before returning to work, and many women breast fed and worked concomitantly. A Cox multivariate analysis took into account six significant variables: "bad" milk (lower duration), mother who had been fed, mother satisfied with breast feeding, multiparity, high maternal education, closer proximity of baby to mother (longer duration). DISCUSSION: The duration in our study is longer than in other studies in France. Predictive factors are sociological, linked to maternal education, and psychological, with antecedent of mother breast feeding and decision before pregnancy. The role of the mother's occupation was not very important because working women are generally at a higher social level. The role of the father was analysed, as well as the role of professional workers, family and breast feeding women's associations. CONCLUSION: Factors of breast feeding duration can be somewhat modified, but it is necessary to respect the plans of both the mother and the father. However, early assistance in the hospital and after discharge can help parents realize their plans for prolonged breast feeding and helps obviating the cessation of 20% of mothers during the 1st month.