Detection of Genotype-Specific Antibody Responses to Glycoproteins B and H in Primary and Non-Primary Human Cytomegalovirus Infections by Peptide-Based ELISA

Background: Strain-specific antibodies to human cytomegalovirus (HCMV) glycoproteins B and H (gB and gH) have been proposed as a potential diagnostic tool for identifying reinfection. We investigated genotype-specific IgG antibody responses in parallel with defining the gB and gH genotypes of the infecting viral strains. Methods: Subjects with primary (n = 20) or non-primary (n = 25) HCMV infection were studied. The seven gB (gB1-7) and two gH (gH1-2) genotypes were determined by real-time PCR and whole viral genome sequencing, and genotype-specific IgG antibodies were measured by a peptide-based enzyme-linked immunosorbent assay (ELISA). Results: Among subjects with primary infection, 73% (n = 8) infected by gB1-HCMV and 63% (n = 5) infected by gB2/3-HCMV had genotype-specific IgG antibodies to gB (gB2 and gB3 are similar in the region tested). Peptides from the rarer gB4-gB7 genotypes had nonspecific antibody responses. All subjects infected by gH1-HCMV and 86% (n = 6) infected by gH2-HCMV developed genotype-specific responses. Among women with non-primary infection, gB and gH genotype-specific IgG antibodies were detected in 40% (n = 10) and 80% (n = 20) of subjects, respectively. Conclusions: Peptide-based ELISA is capable of detecting primary genotype-specific IgG responses to HCMV gB and gH, and could be adopted for identifying reinfections. However, about half of the subjects did not have genotype-specific IgG antibodies to gB.     

Personality type and neural circulatory control

Psychosocial factors, including type A personality, anger, hostility, and anxiety, have been implicated in the pathogenesis of cardiovascular disease. Abnormal sympathetic responses to stress may help explain the link between certain behavior patterns and cardiovascular disease. We tested the hypothesis that in normal humans, type A personality characteristics are associated with exaggerated heart rate, pressor, and sympathetic nerve responses to mental and physical stress. We measured heart rate, blood pressure, and muscle sympathetic nerve activity (obtained with direct intraneural recordings) at rest and during stress in 45 healthy subjects (19 men and 26 women, age 29.2+/-8.7 years) who had no chronic diseases and were taking no medications. Subjects were divided into tertiles based on type A scores. There were no significant differences in sympathetic or hemodynamic reactivity among the 3 different intensity levels of type A characteristics. Baseline measures and responses to stress tests were similar across the 3 groups. Sympathetic and hemodynamic changes during stress tests were also similar in subject groups stratified according to anger scale and cynicism scale. Sympathetic nerve and hemodynamic measurements at rest and during stress were not different in normal subjects with type A characteristics. Abnormalities in sympathetic or cardiovascular reactivity are unlikely to be implicated in any excess of cardiovascular disease in people with type A personality characteristics.     

Diurnal changes in the plasma concentrations of thyroxine and triiodothyronine and their binding to plasma proteins in the domestic duck (anas platyrhynchos)

Ducks were maintained on a 12-hr photoperiod and plasma concentrations of thyroxine (T₄) and triiodothyronine (T₃), the Sephadex T₄- and T₃-binding coefficients (T₄-BC and T₃-BC), and the free T₄ and T₃ indices (FT₄I and FT₃I) were measured at 2-hr intervals over a 24-hr period. Diurnal rhythms which could be fitted to theoretical sinusoidal curves were demonstrated for T₄ (P = 4.35 × 10^?6) and FT₄I (P = 1 × 10^?4) but not T₄-BC. The acrophases for T₄ and FT₄I were during the dark period. Changes in plasma T₃ concentration fitted a sinusoidal curve (P = 0.0056) with an acrophase during the photophase, but T₃-BC did not. There was evidence that changes in T₃ binding compensated for fluctuations in T₃ concentration. Changes in FT₃I did not follow a diurnal rhythm for there were peaks during the photophase and the scotophase.