Interdisciplinary approach to functional voice disorders: the psychiatrist''s role

The Trichuris muris-mouse model of intestinal helminth infection provides a convenient system to examine the immune mechanisms operating during acute and chronic infection. Particular subsets of helper T lymphocytes (CD4+Th cells) play an important role in regulating infection via the secretion of distinct groups of cytokines. Reciprocal activation of Th cell subsets is associated with either expulsion of the parasites from the intestine (Th2 cells) or chronic infection (Th1 cells). In vivo neutralization experiments using anti-cytokine monoclonal antibodies show that critical cytokines are involved, with interferon-gamma playing an important role in the establishment of chronic trichuriasis and interleukin-4 in expulsion of the parasite from the gut. This model has provided clear evidence of a crucial role for distinct cytokines in mediating host protection against intestinal helminth infection and that manipulation of the immune response through the Th cell-cytokine axis can benefit either the host or the parasite. As such, the T. muris model is poised to generate important new data relevant not only to intestinal helminthiasis but to the wider field of parasite immunity and infection in general.     

Production of anti-erythrocyte antibodies by leukemic and nonleukemic B cells in chronic lymphocytic leukemia patients

We have assessed the specificity of antibodies from the leukemic B cells of five patients with both chronic lymphocytic leukemia and autoimmune hemolytic anemia (CLL-AHA). Leukemic cells from one patient displayed surface immunoglobulin with heavy and light chain isotypes identical to that of the patient's anti-red blood cell (RBC) antibodies, and the leukemic cells secreted antibodies in vitro with anti-RBC activity. However, in the remaining patients, the leukemic cells displayed surface immunoglobulin with light chain isotypes different from that of the patient's anti-RBC antibodies and secreted antibodies in vitro with no detectable anti-RBC activity. Thus, there are two distinct classes of CLL-AHA patients, differentiated by the presence or absence of an anti-RBC antibody-producing leukemic B cell clone. The apparent heterogeneity in the source of pathogenic anti-RBC antibodies may impact the treatment response of the two classes of CLL-AHA patients.     

Comparison of different separative techniques in the quantitative determination of active compound enclosed in liposomal systems

The suitability of three different separative techniques, dialysis, gel filtration and centrifugation, for determining the percentage of active compound included (PAI) in liposomal systems was assessed. Two model compounds, glucose and vitamin E acetate were encapsulated in dipalmitoylphosphatidylcholine (DPPC), soybean lecithin (SL) and hydrogenated soybean lecithin (HSL) multilamellar vesicles (MLV). Vitamin E acetate PAI values from DPPC MLV liposomes obtained by dialysis, gel filtration and centrifugation, were compared with those determined by differential scanning calorimetry. Glucose PAI values from DPPC MLV liposomes, obtained using the same separative techniques, were compared with that calculated by taking into account the glucose content of the liposome internal aqueous phase on the basis of liposome mean size determined by light scattering.
Vitamin E acetate and glucose PAI values from SL and HSL liposomes were compared with those obtained for DPPC liposomes. Dialysis proved suitable for PAI determination for both lipophilic and hydrophilic compounds, centrifugation was found to be suitable only for the determination of lipophilic compound PAI values while gel filtration using Sephadex G-25M proved inadequate for the determination of PAI values for both lipophilic and hydrophilic compounds in the experimental conditions used in this study.     

316L不锈钢中添加Al后的抗腐蚀性能

合金中添加Al可提高其抗腐蚀性能.在316L不锈钢中添加不同含量的Al,研究了合成的合金在5%H2SO4中的均匀腐蚀速率和在65%浓HNO3中的晶间腐蚀速率.结果表明:合金均匀腐蚀速率和晶间腐蚀速率均随着Al含量增加先减小后增大;添加2.00%,4.00%Al的合金的均匀腐蚀速率和晶间腐蚀速率较低;添加了Al的合金的晶间腐蚀速率低于未加Al的合金.     

A MARANTHUS CRUENTUS LECTIN: PURIFICATION, STABILITY, AND SOME BIOCHEMICAL PROPERTIES

Amaranth lectin from Amaranthus cruentus seeds was isolated, purified and partially characterized. The purification method used was based on its ability to interact with fetuin. Effects of temperature, pH and buffers and concentration were determined by measurement of lectin hemagglutination activity. Amaranth lectin biological activity was best maintained at temperatures between 4 and 30°C and pH's above or below 5. It was possible to store amaranth lectin at 4°C in acetate buffers, pH 4.8, for prolonged periods and to concentrate it 10-fold by ultrafiltration with only 18% loss of activity. A subunit molecular weight of 32,500 daltons was determined by SDS-PAGE for amaranth lectin.     

Physico-chemical properties of a protein-inhibitor of serine proteinases from the potato]

Serine proteases inhibitor with pl-7.3, isolated from potatoe tubers by isoelectric focusing procedure as described previously (V.V. Mosolov et al., Bioorganic Chem., 1, 1449, 1975), was homogeneous under ultracentrifugation, having sedimentation coefficient S20,w 2.8S. Its molecular weight, investigated by sedimentation equilibrium and gel filtration through Sephadex G-100, was found to be 32500 and 31500 respectively. The Stokes radius R and frictional ratio f/fo were found to be 24 A and 1.14. The molecular weight of the inhibitor as determined by sodium dodecylsulfate polyacrylamide electrophoresis was twice as low as determined in ultracentrifuge and by gel filtration procedure. It is suggested that the inhibitor is dimer and consists of two protomers of equal molecular weight.