Epitope Characterization of an Aromatase Monoclonal Antibody Suitable for the Assessment of Intratumoral Aromatase Activity

Immunohistochemistry is one of the most suitable methods for the detection of intratumoral aromatase in order to identify patients who may respond to aromatase inhibitor therapy in hormone-dependent breast cancer. Previous studies showed statistically significant correlation between results of immnuohistochemistry and biochemical analysis in carcinoma components stained by aromatase monoclonal antibody 677. In this study, determination of the antigenic peptides recognized by aromatase antibodies through epitope mapping, combined with the new knowledge on aromatase-reductase interaction, provide insights for understanding various immunostaining patterns using different aromatase antibodies. Our studies on aromatase-reductase interaction also provided critical information on how aromatase and reductase interact with each other on the endoplasmic reticulum membrane, and identified key residues, including K108 of aromatase, that are involved in the interaction with reductase. Through epitope mapping and taking into consideration the interference with aromatase immunohistochemical staining by NADPH-cytochrome P450 reductase, we demonstrated that monoclonal antibody 677 is a suitable antibody for an assessment of intratumoral aromatase activity in breast cancer patients for making clinical management decisions. These results also provide valuable information to identify new aromatase antibodies for immunohistochemical diagnosis of hormone-dependent breast cancer in future.     

Association of Serum Parathyroid Hormone Levels With All-Cause and Cause-Specific Mortality Among U.S. Adults

ObjectiveTo examine whether parathyroid hormone (PTH) is associated with mortality among U.S. adults.MethodsThis study included 8286 U.S. adults aged ≥20 years with a measurement of serum intact PTH from the National Health and Nutrition Examination Survey 2003-2006 linked to national mortality data through 2015. Multivariable Cox proportional hazard regression models were employed to estimate the adjusted hazard ratio (aHR) of all-cause and cause-specific (cardiovascular and cancer) mortality according to intact PTH levels (low or low-normal, <38; middle-normal, 38-56; high-normal, 57-74; high, >74 pg/mL). We also stratified the analyses by serum albumin-adjusted calcium and 25-hydroxy vitamin D (25OHD) levels.ResultsDuring a median follow-up of 10.1 years, the mean age was 49 years, and 48% were men. After adjusting for potential confounders, both the high-normal and high PTH groups showed higher risks of all-cause mortality than the low or low-normal PTH group (high-normal PTH, aHR, 1.28; 95% confidence interval [CI], 1.10-1.48; high PTH, aHR, 1.42; 95% CI, 1.19-1.69]. When stratified by calcium and 25OHD levels, the association between high PTH and mortality was also found among participants with albumin-adjusted calcium levels of ≥9.6 mg/dL (aHR, 1.53; 95% CI, 1.17-2.01) and those with 25OHD levels of ≥20 ng/mL (aHR, 1.46, 95% CI, 1.17-1.82). We found no evidence of the increased cause-specific mortality risks in the high PTH group.ConclusionHigher PTH levels were associated with an increased risk of all-cause mortality, particularly among participants with albumin-adjusted calcium levels of ≥9.6 mg/dL or 25OHD levels of ≥20 ng/mL.     

Endogenous thiol protease inhibitor from rat liver

A thiol protease inhibitor was purified from rat liver by a rapid procedure involving heat treatment of the post-lysosomal fraction, affinity chromatography on papain-Sepharose 4B and Sephadex G-75. The purified inhibitor appeared homogeneous on sodium dodecyl sulfate electrophoresis. The inhibitor had a molecular weight of about 11,500 and consisted of three forms (pI 4.9, 5.2 and 5.6). The preparation inhibited thiol proteases, such as papain, cathepsin H, cathepsin B and cathepsin L, but not serine proteases (trypsin, chymotrypsin, mast cell protease and cathepsin A) or cathepsin D.     

Ultrastructural localization of hCG in the placenta and in testicular germ cell tumors

Human chorionic gonadotrophin(hCG)-producing cells in the human placenta and in testicular germ cell tumors have been investigated by ultrastructural immunohistochemistry using labeled Fab'fragments of anti-hCG-alpha and anti-hCG-beta. Most reaction products were demonstrated in the rough endoplasmic reticulum (rER) and perinuclear spaces of syncytiotrophoblastic giant cells ( STGC ) occurring in embryonal carcinomas and in syncytial cells observed in choriocarcinomas and in normal placenta. The rER of placental and choriocarcinomatous syncytial cells was highly developed and invariably showed a positive reaction. However, the rER of STGCs varied both with regard to its degree of development and its immunoreactivity with hCG. Localization of hCG in the Golgi apparatus and in cytoplasmic granules was indefinite. Mononuclear cells reacting positively with anti-hCG-alpha or -beta were also demonstrated. Cytotrophoblast-like cells which failed to react with anti-hCG-alpha or -beta were noted adjacent to sTGCs and the significance of these cells is discussed.     

Establishment of hybridomas secreting human monoclonal antibodies against tetanus toxin and hepatitis B virus surface antigen

Mouse-human heterohybrids (M X H) were constructed and compared with other cell lines (human or mouse) as parental cells to obtain hybrids secreting human monoclonal antibody (MoAb). One of the M X H lines, HM-5, was far superior to the others and useful for establishing hybrids secreting human MoAb. Using HM-5 as a parental cell line, we have obtained 2 hybrids secreting human anti-tetanus toxoid MoAb with neutralizing activity and a hybrid secreting human anti-hepatitis B virus surface antigen (HBsAg) MoAb which recognizes the a-determinant of HBsAg.     

Grouping of isolates in AG 2 ofRhizoctonia solani by total cellular fatty acid analysis

Total-cellular fatty acid compositions of 34 isolates ofRhizoctonia solani belonging to intraspecific groups (ISGs) of anastomosis group (AG) 2, i.e., AG 2-1, AG 2-2 IIIB (mat rush), AG 2-2 IV (sugar beet), AG 2-2 LP (turfgrass), and AG 2–3 (soybean), were compared. The major fatty acids identified were palmitic, stearic, and oleic acids. Principal component analysis based on the percentage composition of total cellular fatty acids revealed consistently low variability among isolates of a single ISG of AG 2. Average linkage cluster analysis showed that isolates obtained from turfgrass representing a newly proposed group, AG 2-2 LP, were differentiated from other AG 2 ISGs. Isolates of another newly proposed group AG 2–3, from diseased soybean were also closely related to AG 2-1 and AG 2-2 IIIB but distinguishable from the AG 2-1 and AG 2-2 LP isolates by the average linkage cluster analysis. These results suggested that the percentage composition of total-cellular fatty acids is a distinct characteristic for the five ISGs belonging to AG 2, and fatty acid analysis is useful for the differentiation and characterization of these ISGs of AG 2 inR. solani.