The histological response to chemotherapy as a predictor of the oncological outcome of operative treatment of Ewing sarcoma

Seventy-four patients who had a Ewing sarcoma of bone were managed with preoperative and postoperative chemotherapy and operative resection, with or without postoperative irradiation. The primary objectives of the study were to determine the histological response to preoperative chemotherapy in terms of the percentage of tumor necrosis and to assess the relationship between the histological response and the oncological outcome. The minimum duration of follow-up of the surviving patients who were continuously free of disease was five years. Sections of each operative specimen were examined, and the histological response to chemotherapy was graded semiquantitatively. Grade I indicated necrosis of 50 per cent of the tumor or less; grade II, necrosis of more than 50 per cent but less than 90 per cent; grade III, necrosis of 90 to 99 per cent; and grade IV, necrosis of 100 per cent of the tumor. Of the seventy-four tumors, forty-four (59 per cent) were exquisitely sensitive to chemotherapy and had complete (grade-IV) or nearly complete (grade-III) necrosis. In contrast, fourteen tumors (19 per cent) had little or no response to chemotherapy (grade I) and sixteen (22 per cent) had a moderate degree of necrosis (grade II). The histological response to preoperative chemotherapy (p = 0.0001), followed by the size of the tumor (p = 0.001), were the most important predictors of event-free survival. At five years, the rate of event-free survival was zero of fourteen patients who had had a grade-I response, six of sixteen who had had a grade-II response, and thirty-seven (84 per cent) of forty-four who had had a grade-III or IV response. The risk of local recurrence was most strongly associated with the operative margins; there were only four local recurrences (6 per cent) after sixty-seven resections with negative margins. Local recurrence may also have been influenced by the histological response and the use of local radiation. There were no local recurrences after operative treatment of six tumors that had been associated with pathological fracture. The histological response to preoperative chemotherapy and the size of the primary tumor are the most important clinical predictors of the outcome of operative treatment of non-metastatic Ewing sarcoma. These indicators should be used to identify patients who are at high risk for metastasis as such patients may be candidates for more intensive or novel therapies.     

Recombinant human erythrocyte cytochrome b5

The gene encoding the human erythrocyte form of cytochrome b5 (97 residues in length) has been prepared by mutagenesis of an expression vector encoding lipase-solubilized bovine liver microsomal cytochrome b5 (93 residues in length) (Funk et al., 1990). Efficient expression of this gene in Escherichia coli has provided the first opportunity to obtain this protein in quantities sufficient for physical and functional characterization. Comparison of the erythrocytic cytochrome with the trypsin-solubilized bovine liver cytochrome b5 by potentiometric titration indicates that the principal electrostatic difference between the two proteins results from two additional His residues present in the human erythrocytic protein. The midpoint reduction potential of this protein determined by direct electrochemistry is -9 +/- 2 mV vs SHE at pH 7.0 (mu = 0.10 M, 25.0 degrees C), and this value varies with pH in a fashion that is consistent with the presence of a single ionizable group that changes pKa from 6.0 +/- 0.1 in the ferricytochrome to 6.3 +/- 0.1 in the ferrocytochrome with delta H degrees = -3.2 +/- 0.1 kcal/mol and delta S degrees = -11.5 +/- 0.3 eu (pH 7.0, mu = 0.10). The 1D 1H NMR spectrum of the erythrocytic ferricytochrome indicates that 90% of the protein binds heme in the "major" orientation and 10% of the protein binds heme in the "minor" orientation (pH 7.0, 25 degrees C) with delta H degrees = -2.9 +/- 0.3 kcal/mol and delta S degrees = -5.4 +/- 0.9 eu for this equilibrium.     

Relationship of depressive, conduct, and comorbid disorders and social functioning in childhood

OBJECTIVE: To examine the relationship of depressive, conduct, and comorbid disorders and social functioning in psychiatrically referred youths. METHOD: Subjects were 94 boys and 67 girls (mean age at initial assessment = 11.5 years) who were repeatedly evaluated with standardized instruments during a mean interval of 4.4 years. On the basis of their diagnoses during the follow-up, children were designated as having had depressive, conduct, or both (comorbid) disorders or other conditions. Two domains of social functioning were assessed: social competence and self-esteem. RESULTS: Longitudinal analyses revealed that at any given point in time, depressive, conduct, and comorbid disorders were associated with low social competence and depressive disorder also was associated with low self-esteem. At the approximate age of 15 years, on average, children with a history of conduct or comorbid disorders had lower social competence than did children with a history of depressive disorder, but these groups endorsed similar levels of self-esteem. CONCLUSION: Some areas of social dysfunction associated with comorbid depressive and conduct disorders appear to reflect mostly the effects of conduct disorder. The latter condition has a more severe and longer-term impact on children's social competence than does depression. In addition, whereas depression has an adverse effect on self-esteem, this effect appears to be temporary.     

Recurrent Meesmann''s corneal epithelial dystrophy after penetrating keratoplasty

Endoscopic treatment of chronic pancreatitis has drawn benefits from endoscopic procedures previously described for the main bile duct. Endotherapy is developing throughout the world. Cyst drainage procedures certainly represent the largest step forward in that non-surgical approach, whatever it is either direct (through the stomach or the duodenum) or indirect through the papilla in the duodenum. This procedure gives similar results to surgery with a lower morbidity. Pancreatic duct drainage associated with stone clearance is feasible and provides good results which have not yet been compared with those obtained thanks to surgery. Nonetheless, when the duct is not widely dilated it has been proven to be a satisfactory alternative to surgery. By contrast, chronic cholestasis does not appear to be a good indication of endotherapy.     

Hydrogen bonding at the active site of delta 5-3-ketosteroid isomerase

The solution secondary structure of the highly active Y55F/Y88F "Tyr-14-only" mutant of delta 5-3-ketosteroid isomerase complexed with 19-nortestosterone hemisuccinate has been shown to consist of three helices, a six-stranded mixed beta-sheet, and five turns. The steroid binds near the general acid, Tyr-14, on helix 1, near the general base, Asp-38, on the first strand of the beta-sheet, and on the hydrophobic face of the beta-sheet [Zhao, Q., Abeygunawardana, C., & Mildvan, A. S. (1997) Biochemistry 36, 3458-3472]. On this hydrophobic face, Asp-99 is the only polar residue. Free isomerase shows a deshielded exchangeable proton resonance at 13.1 ppm assigned to the N epsilon H of neutral His-100. Its fractionation factor (phi = 0.79) and slow exchange with solvent suggest it to be buried or involved in an H-bond. The binding of dihydroequilenin or estradiol to isomerase induces the appearance of two additional deshielded proton resonances, one at 18.2 ppm assigned to the gamma-carboxyl proton of Asp-99, and the other, at 11.6 ppm, assigned to the zeta-OH proton of Tyr-14. While mutation of Asp-99 to Ala results in the disappearance of only the resonance near 18 ppm [Wu, R. W., Ebrahemian, S., Zwrotny, M. E., Thornberg, L. D., Perez-Alverado, G. C., Brothers, P., Pollack, R. M., & Summers, M. F. (1997) Science 276, 415-418], both of these resonances disappear in mutants lacking Tyr-14, suggesting an H-bonded catalytic diad, Asp-99-COOH--Tyr14-OH--O-steroid enolate. The catalytic diad is further supported by NOEs from the beta 1 and beta 2 protons of Asp-99 to the epsilon protons of Tyr-14, and from the zeta-OH proton of Tyr-14 to the gamma-carboxyl proton of Asp-99, indicating close proximity of these two residues, and by other data from the literature. A strong, low-barrier H-bond between Asp-99 and Tyr-14 is indicated by the 6.2 ppm deshielding, low fractionation factor (phi = 0.34) and slow exchange of the resonance at 18.2 ppm. A normal H-bond between Tyr-14 and the steroid is indicated by the 1.8 ppm deshielding, fractionation factor of 0.97 and the slow exchange of the resonance at 11.6 ppm. It is suggested that the 10(4.7)-fold contribution of Tyr-14 to catalysis is made possible by strong H-bonding from Asp-99 in the catalytic diad which strengthens general acid catalysis by Tyr-14. It is also noted that highly deshielded proton resonance on enzymes between 15 and 20 ppm, assigned to low-barrier H-bonds, generally involve carboxyl groups.     

Expression of the bcl-2 oncoprotein in meningiomas

The purpose of this study was to assess the expression of the bcl-2 oncoprotein in meningiomas and to compare it with the phenotype, the Ki-67 proliferative index and the sex hormone receptor status of the tumors. The expression of the bcl-2 oncoprotein was studied by Western blotting and immunohistochemistry. A quantitative study of the Ki-67 proliferative index and the expression of estrogen and progesterone receptors was performed. Western blot detected the bcl-2 oncoprotein in nearly all meningiomas. Immunohistochemistry detected the oncogene in only 43.5% of the cases. Expression of bcl-2 was essentially by spindle cells of transitional and fibrous meningiomas expressing neural cell adhesion molecule. There was neither correlation between the expression of bcl-2 and Ki-67 proliferative index of meningiomas nor statistical concordance between the expression of bcl-2 oncoprotein by meningiomas and their sex hormone receptor protein status. Inhibition of apoptosis could be involved in the growth of meningiomas with a mesenchymal differentiation.     

Preparation and evaluation of slow-release pan-coated indomethacin granules

Granules containing indomethacin crystals are coated with Eudragit solutions of different RL/RS ratios using a pan coating technique. The process is reproducible with regard to drug content, inexpensive and the formed granules were directly compressed into tablets. In vitro release of indomethacin from coated granules, tablets and capsules was studied as a function of different ratios of Eudragit RL/RS in the coating solution. The release of the drug was significantly reduced by the coating process in comparison with a formulation made from uncoated granules, prepared using 10 per cent gelatin solution as a binder. Release data were found to follow a diffusion-controlled model.     

The prolonged hematologic effects of a single injection of PEG-rHuMGDF in normal and thrombocytopenic mice

A single injection of > or =10 microg/kg PEG-rHuMGDF in mice causes a dose-dependent increase in circulating platelets beginning on day 3 and peaking on days 5-6. The mean platelet volume and platelet distribution width at doses > or =100 microg/kg initially increase in a dose-dependent fashion and later decrease. However, the mean platelet volume does not change when platelets are incubated with PEG-rHuMGDF in vitro. The number of marrow megakaryocytes increases in a dose-dependent fashion as early as day 1 and peaks on day 3. Marrow megakaryocyte colony-forming units (CFU-Meg) do not increase on days 1-3 at a dose of 100 microg/kg (a dose that increases platelet numbers two- to threefold and may be clinically relevant), but the relative frequency of high ploidy megakaryocytes and the proportion of large marrow megakaryocytes (29-50 microm in diameter) increases. After a dose of 1,000 microg/kg the percentage of megakaryocytes in mitosis peaks at 24-48 hours and the percentage of megakaryocytes incorporating BrdU is maximal at 48 hours, the relatively delayed peak of BrdU incorporation most likely representing endomitosis. The relative frequency of type II and III megakaryocytes peaks on days 3 and 4, respectively. Pharmacokinetic analysis of PEG-rHuMGDF shows peak serum concentrations at 2-4 hours and a terminal half-life of 11.4+/-2.5 hours. A single injection of PEG-rHuMGDF ameliorates carboplatin-induced megakaryocytopenia and thrombocytopenia in a dose-response dependent fashion. In conclusion, a single injection of PEG-rHuMGDF increases megakaryocyte and platelet production in normal and myelo-suppressed mice.     

Specific recognition of HLA-E, but not classical, HLA class I molecules by soluble CD94/NKG2A and NK cells

The CD94/NKG2 receptors expressed by subpopulations of NK cells and T cells have been implicated as receptors for a broad range of both classical and nonclassical HLA class I molecules. To examine the ligand specificity of CD94/NKG2 proteins, a soluble heterodimeric form of the receptor was produced and used in direct binding studies with cells expressing defined HLA class I/peptide complexes. We confirm that CD94/NKG2A specifically interacts with HLA-E and demonstrate that this interaction is dependent on the association of HLA-E with peptide. Moreover, no interaction between CD94/NKG2A and classical HLA class I molecules was observed, as assayed by direct binding of the soluble receptor or by functional assays using CD94/NKG2A+ NK cells. The role of the peptide associated with HLA-E in the interaction between HLA-E and CD94/NKG2A was also assessed. All class I leader sequence peptides tested bound to HLA-E and were recognized by CD94/NKG2A. However, amino acid variations in class I leader sequences affected the stability of HLA-E. Additionally, not all HLA-E/peptide complexes examined were recognized by CD94/NKG2A. Thus CD94/NKG2A recognition of HLA-E is controlled by peptide at two levels; first, peptide must stabilize HLA-E and promote cell surface expression, and second, the HLA-E/peptide complex must form the ligand for CD94/NKG2A.