The effect of psychosocial factors on lung cancer mortality at one year

In this study newly diagnosed male and female lung cancer patients admitted to two Ontario Cancer Foundation treatment clinics were interviewed. Information was obtained on demographic variables, presence of other chronic illness and the following psychosocial attributes: locus of control, social support and personality traits. From the clinic charts, information on stage of disease and pathological diagnosis was obtained. After controlling for the effects of stage and pathological diagnosis, the following psychological variables were found to increase the odds of death from lung cancer among males and females combined at one year after diagnosis: a high need for one aspect of social support, a reserved personality and the extremes of the personality trait soberness vs enthusiasm.     

FM sonography in diffuse liver disease: prospective assessment and blinded analysis

FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease.     

用于筛选天然产物中脲酶抑制剂的脲酶活性测试方法的建立

抑制幽门螺杆菌产生的脲酶具有治疗胃炎和消化性溃疡的作用。用酚红指示剂和Ｂｅｒｔｈｅｌｏｔ试剂在９６孔培养板上检测重组脲酶活性，其灵敏度指标酚红法每ｍｇ酶蛋白引起的每分钟吸光度变化。△Ａ为６．９，而Ｂｅｒｔｈｅｌｏｔ法每ｍｇ酶蛋白引起的每分钟吸光度比值变化△Ａ为３１３。结果表明用Ｂｅｒｔｈｅｌｏｔ试剂检测重组脲酶活性适宜在９６孔培养板上大规模筛选天然产物中的脲酶抑制剂。     

Role of the endothelial adhesion molecule VCAM in murine cardiac allograft rejection.

Murine heterotopic cardiac isografts (C57B1/6----C57B1/6) undergo transient, non-destructive inflammation that is characterized by the acquisition of microvascular endothelial reactivity with the antibody MECA 32. Cardiac allografts (C57B1/6----DBA/2) undergo destructive inflammation that is characterized by the acquisition of reactivity with the antibody M/K-2, in addition to MECA 32. M/K-2 recognizes the murine endothelial adhesion molecule, VCAM-1. Hence, there appear to be antigen-dependent and antigen-independent forms of graft inflammation. Treatment of cardiac allograft recipients with 200 micrograms/day M/K-2 antibody retarded graft loss by only a few days, and did not interfere significantly with leukocytic infiltration, as detected by limiting dilution analysis of graft-reactive CTL, despite the fact that large amounts of M/K-2 could be detected on graft microvascular endothelia and in the peripheral blood as rejection progressed. These data indicate that VCAM is apparently not essential for the leukocytic infiltration and subsequent rejection of cardiac allografts, and is not involved in leukocytic infiltration of murine cardiac isografts.     

Identification of non-amplifying CYP21 genes when using PCR-based diagnosis of 21-hydroxylase deficiency in congenital adrenal hyperplasia (CAH) affected pedigrees

Steroid 21-hydroxylase deficiency is among the most common inborn errors of metabolism in man. Characterization of mutations in the 21- hydroxylase gene (CYP21) has permitted genetic diagnosis, facilitated by the polymerase chain reaction (PCR). The most common mutation is conversion of an A or C at nt656 to a G in the second intron causing aberrant splicing of mRNA. Homozygosity for nt656G is associated with profoundly deficient adrenal cortisol and aldosterone synthesis, secondary hypersecretion of adrenal androgens, and a severe form of congenital adrenal hyperplasia (CAH) characterized by ambiguous genitalia and/or sodium wasting in newborns. During the course of genetic analysis of CYP21 mutations in CAH families, we and others have noticed a number of relatives genotyped as nt656G homozygotes, yet showing no clinical signs of disease. A number of lines of evidence have led us to propose that the putative asymptomatic nt656G/G individuals are incorrectly typed due to dropout of one haplotype during PCR amplification of CYP21. For prenatal diagnosis, we recommend that microsatellite typing be used as a supplement to CYP21 genotyping in order to resolve ambiguities at nt656.      

Antibody-induced activation of the hyaluronan receptor function of CD44 requires multivalent binding by antibody

CD44 can function as a receptor for hyaluronan (HA). However, many cell lines and normal hematopoietic cells that express CD44 do not constitutively bind HA. A monoclonal antibody (mAb) specific for CD44 (IRAWB14) has been described previously which induces CD44-mediated binding of HA rapidly (seconds to minutes) in some cell lines and in normal murine T cells. Of 16 CD44-specific mAb tested in the present study, only 3 exhibited this activity. Monovalent Fab fragments were prepared from two IgG2a antibodies that induce HA binding (IRAWB 14 and IRAWB 26) and used to determine whether multivalent binding was required for induction of HA receptor function. Fab from both antibodies had a tendency to form multivalent aggregates. After addition of iodoacetamide to prevent further aggregation, multimeric and monovalent forms were separated by gel filtration. This made it possible to compare the inducing activity of monovalent and multivalent antibody fragments of identical composition in the absence of Fc determinants. Multimeric forms were very active at inducing binding of fluorescein-conjugated HA (Fl-HA). Monovalent Fab fragments of both antibodies had 20- to 50-fold lower binding activity than intact antibody or multimer. IRAWB 26 Fab monomers were completely inactive in the induction of HA-binding. The observed weak inducing activity of IRAWB 14 Fab monomer could be attributed to very low levels of contaminating multimer. Induction of HA binding could also be achieved by using anti-immunoglobulin to cross-link Fab monomers of IRAWB 26. Thus, multivalent binding was required for the activation of HA binding by CD44-specific antibody, suggesting that the distribution of CD44 molecules on the cell surface is important for HA receptor function. In kinetic studies, induction of HA receptor function occurred simultaneously with antibody binding at 0°C (ice water bath). Furthermore, antibody could induce HA binding in paraformaldehyde-fixed cells, which were permeable to propidium iodide and trypan blue, suggesting that intracellular signaling mechanisms were not involved in induction of receptor function. We conclude, therefore, that these CD44-specific antibodies are inducing HA binding by directly influencing the distribution of CD44 on the cell surface. The possibility of a concurrent change in CD44 conformation is not ruled out. We discuss possible mechanisms by which CD44 might be activated to bind HA in vivo.     

Unique properties of fetal lymphoid progenitors identified according to RAG1 gene expression

RAG1/GFP knockin mice were exploited to isolate and characterize fetal lymphoid progenitors. CD11b and IL-7Ralpha are expressed in a developmental stage-dependent fashion, revealing how substantial numbers of early lymphoid progenitors were discarded or neglected in previous studies. The myeloerythroid potential of fetal progenitors in clonal assays declined in synchrony with activation of the RAG1 locus but was not completely extinguished. Lymphoid differentiation corresponded to patterns of gene expression previously found for adult marrow, but no fraction of fetal liver was enriched with respect to B + T progenitors. Also, unlike adults, fetal lymphoid progenitors transiently expressed endothelial cell markers. These findings help to reconcile discrepancies in previous reports and suggest that the fetal immune system arises via unique mechanisms.     

Identification of very early lymphoid precursors in bone marrow and their regulation by estrogen

Estrogen is a negative regulator of lymphopoiesis and provides an experimental tool for probing relationships between lymphocyte precursors and stem cells. We found that expression of lymphocyte-associated genes and immunoglobulin (Ig) gene rearrangement occurred before CD45R acquisition. Lymphoid-restricted progenitors that were Lin(-)IL-7R alpha(+)c-kit(lo)TdT(+) (lineage marker(-), interleukin receptor 7 alpha(+), c-kit(lo) and terminal deoxynucleotidyl transferase(+)) were selectively depleted in estrogen-treated mice; within a less differentiated Lin-c-kit(hi) fraction, functional precursors of B and T, but not myeloid, cells were also selectively depleted. TdT and an Ig heavy chain transgene were detected within a hormone-regulated Lin(-)c-kit(hi)Sca-1(+)CD27(+)Flk-2(+)IL-7R alpha(-) subset of this multipotential progenitor population. Identification of these extremely early lymphoid precursors should facilitate investigation of the molecular mechanisms that control lineage-fate decisions in hematopoiesis.     

Co-expression of different types of Fc receptors on murine peritoneal macrophages

Simultaneous expression of particular immunoglobulin Fc receptors (FcR) was studied on the plasma membranes of murine peritoneal macrophages. This was facilitated by the use of sheep red blood cells (SRBC) and/or synthetic microspheres coated with monoclonal antibodies of different isotypes. It was concluded that a majority of macrophages bear more than one type of FcR; macrophages bearing at least three types of FcR were present in the peritoneal cavity; macrophages bearing Fc mu R did not bind IgE, IgA or IgG; all macrophages bearing Fc alpha R also expressed Fc gamma 2bR, Fc gamma 3R and Fc epsilon R; all macrophages bearing Fc epsilon R also expressed Fc gamma 2bR and Fc alpha R. Except for Fc alpha R, essentially equivalent numbers of FcR-bearing macrophages were detected when antibody-coated SRBC or polymeric microspheres were used. Simultaneous applications of these reagents permitted the most detailed and direct investigations yet performed of multiple FcR expression on individual cells.