Mandibular reaction time to auditory and visual signals in young and elderly subjects

Mandibular reaction time was measured in young and elderly volunteers. Each subject was instructed to open the jaw from the closed position and to close the jaw from the open position as quickly as possible after perceiving an auditory or visual signal. The reaction time of the elderly subjects to both signals was significantly slower than that of the young subjects. This was due almost entirely to prolongation of the premotor time component. There was no difference in the maximum velocity of the jaw movement between the two groups of subjects.     

Conformation of sequential peptides containing proline residues

The conformational properties of Boc-Leu₃-(Pro₂GlyLeu₃)_n-Pro₂Gly-OH(n = 0, 1, 3, and 5) and Boc-Leu₃-(Pro₂GlyLeu₃)_n-Pro₂Gly-OBzl (n = 7, 9, and 11) were investigated in various organic solvents of high polarity using molar rotation and CD measurements. The peptides examined are assembled by the N-terminal, internal, and C-terminal segments having the sequences of Boc-Leu₃, Pro₂Gly-Leu₃, and Pro₂Gly-OX (X = H or Bzl), respectively. The conformational studies using the molar rotation of the oligopeptides and polypeptides in MeOH, DMSO, DMF, DMA, and NMP have made it clear that all the peptides have a randomly coiled structure. CD spectral patterns of the peptides in MeOH were essentially the same as each other and indicative of the randomly coiled structure. The additive nature of the total molar rotation and total molar ellipticity in Boc-Leu₃-(Pro₂GlyLeu₃)_n-Pro₂Gly-OX (X = H or Bzl) indicates that the “peptide segment separation” is indeed in operation in organic solvents of high polarity and that the peptide molecule can be considered to be assembled with the small peptide segments having a randomly coiled structure.     

A defective autologous mixed lymphocyte reaction in patients with idiopathic portal hypertension

The aetiology of idiopathic portal hypertension or hepatoportal sclerosis is unknown. In view of the indirect evidence for underlying immunologic abnormalities 14 patients (all middle-aged females) were studied. Various auto-antibodies were demonstrated in seven patients and high levels of serum immunoglobulins, either IgG, IgM or IgA were present in ten patients. T cell responsiveness to stimulation with either autologous or allogeneic non-T cells was examined in nine of 14 idiopathic portal hypertension patients and compared with responsiveness in patients with posthepatitic cirrhosis and splenomegaly, and healthy controls. Patients with cirrhosis had levels of T cell responsiveness which were not significantly different from those in healthy controls in both autologous and allogeneic mixed lymphocyte reactions. A distinctly reduced autologous mixed lymphocyte reaction was observed in all idiopathic portal hypertension patients. These data indicate that, like many other autoimmune diseases, abnormal serological features and impaired autoreactive T cell responsiveness exist in patients with idiopathic portal hypertension.     

Increased release of myeloperoxidase in vitro from neutrophils of patients with myeloperoxidase-specific anti-neutrophil cytoplasmic antibody (MPO-ANCA) related glomerulonephritis

Summary: In order to elucidate the role of neutrophils in the pathogenesis of MPO-specific anti-neutrophil cytoplasmic antibody (MPO-ANCA) related glomerulonephritis (GN), MPO release, beta-glucuronidase (BGL) release, superoxide anion (O₂⁻) production from the neutrophils of patients with MPO-ANCA related GN were measured. the effect of plasma on MPO release from neutrophils was also studied in patients with MPO-ANCA related GN. Neutrophils and plasma were obtained from patients with MPO-ANCA related GN, GN unrelated to MPO-ANCA and healthy controls. MPO release from the neutrophils of patients with MPO-ANCA related GN was higher than that of controls significantly. This was also higher than that in patients with GN unrelated to MPG-ANCA, but this was not statistically significant. Superoxide anion production from neutrophils of patients with MPO-ANCA related GN was significantly higher than that in patients with GN unrelated MPO-ANCA, However, BGL release was not significantly different among three groups. Furthermore, MPO release and O₂⁻ production increased in parallel with clinical activity of MPO-ANCA related GN. Neutrophils of patients with MPO-ANCA related GN showed to be significantly more sensitive to FMLP on MPO release than those in the other two groups. However, plasma from MPO-ANCA related GN increased the sensitivity to FMLP on MPO release, but not BGL release, in neutrophils obtained from healthy controls, whereas it suppressed MPO release from neutrophils with MPO-ANCA related GN. This suggests that in patients with MPO-ANCA related GN MPO can be highly released from activated neutrophils and that the plasma of patients with MPO-ANCA contains factor(s) which modulate reactivity of neutrophils.