Alternate Pathway Activation in Sickle Cell Disease and ��-Thalassemia Major

Total hemolytic complement activity (CH50), immuno-electrophoretic conversion of Factor B (C3PA), and of C3 were studied in 16 patients with sickle cell disease in a steady state, eight patients in crisis, and ten patients with β-thalassemia major anemia maintained on a constant transfusion regimen. Patients with sickle cell disease in a steady state have moderatley 56 (percent) depressed conversion of Factor B in addition to markedly decreased conversion of C3 in four of ten patients. One of the three sickle cell patients and two of the four thalassemia patients with low C3 conversion levels have died subsequent to the studies. The combination of chronically decreased Factor B conversion in the face of markedly decreased C3 conversion may make these patients occasionally vulnerable to overwhelming infection analagous to the situation seen in postsplenectomy cases.     

Observations on excystment in vitro ofCotylurus variegatus metacercariae (Trematoda: Strigeidae)

Excystment in vitro ofCotylurus variegatus metacercariae requires a trypsin-bile salt medium for digesting the cyst wall, and events are triggered by a rise in environmental temperature of up to 41°C. Pepsin pretreatment, while effective in removing extraneous host tissues, is not a prerequisite for excystment in vitro. The metacercaria plays an active role in its release, contractile movements being stimulated by bile salts over a temperature range of 30–41° C. Synthetic sodium taurocholate was only one third effective in excystment compared with sodium taurocholate from ox bile. Excystment was maximal at pH 7.5, but conditions of osmolarity, redox potential or gas phase were not of apparent importance.     

Dipeptidyl peptidase 9 sets a threshold for CARD8 inflammasome formation by sequestering its active C-terminal fragment

1. Download : Download high-res image (167KB)
2. Download : Download full-size image

     

Cell-mediated immune responses to chlamydial antigens in guinea pigs injected with inactivated chlamydiae

Cell-mediated immunity (CMI) to chlamydial antigens was readily induced in guinea pigs by a single injection of Betaprone-inactivated chlamydiae in complete Freund adjuvant. The CMI was measured in vivo by delayed hypersensitivity skin tests, and in vitro by inhibition of migration of peritoneal exudate cells and by proliferation of lymph node lymphocytes. There was an overall correlation between in vivo and in vitro responses. Of the in vitro assays, migration inhibition reflected the state of sensitization, as judged by skin tests, more uniformly than lymphocyte stimulation. Extensive inter- and intra-species cross-reactivity was noted between LB-1, a strain ofC. trachomatis, and three strains ofC. psittaci, 6BC, GPIC, and 562F. Cross-reactivity between LB-1 and 6BC was one-way only, by all three parameters: LB-1 elicited strong cross-reactions in 6BC-immunized animals but not vice versa. Antichlamydial antibodies could not be demonstrated in any of the animals by microimmunofluorescence.     

Relationship between health beliefs and psychological variables in diabetic patients

The present paper is focused on the relationship between psychological variables and health beliefs in 93 diabetic men. A Diabetes Health Belief Scale was used to assess general health motivation, treatment beneficial, severity, susceptibility, psychological barriers, cues to action, and structural elements. The psychological variables included two measures of locus of control, depression, somatization, interpersonal sensitivity, obsessive—compulsiveness, anxiety, self-esteem, and attitudes toward diabetes, doctor, and medical care. Ten of the 11 psychological variables were correlated with various aspects of health beliefs. This indicates the extent to which the health beliefs are enmeshed with the psychological dynamics of the person. It would seem important to take such a psychological profile into consideration when attempting to understand and even alter the health beliefs.     

Role of lymphocyte activation products (LAP) in cell-mediated immunity. I. Preparation and partial purification of guinea-pig LAP

Partial purification of soluble products of guinea-pig lymphocyte activation (LAP) was undertaken by fractional precipitation with ammonium sulphate, ion-exchange and Sephadex chromatography, and by immune precipitation of inducing antigen and of contaminating serum protein. During these purification steps the activity of macrophage migration-inhibition factor (MIF) was concentrated up to 1300-fold and separated from inducing antigen and serum protein. An endpoint assay was devised for expressing antigen-induced MIF activity of LAP fractions as weights of material giving 30% inhibition of migration (MI₃₀ doses).

MIF activity precipitated between 50% and 80% saturated ammonium sulphate and eluted from DEAE-cellulose at pH 7·9 at intermediate salt concentrations (0·03–0·2 M phosphate). On Sephadex gel filtration MIF activity was concentrated in fractions of molecular weight range 56,000–82,000 with a smaller amount of activity eluting from 20,000–56,000. After immune precipitation of extraneous protein and elution from DEAE-cellulose, LAP material was found to have an MI₃₀ dose of 0·4 μg.

Materials representative of antigen and serum protein-depleted MIF were selected for intralymphatic injection in order to determine whether MIF-rich LAP fractions were able to induce paracortical distension in guinea-pig lymph nodes (see following paper).

     

Electromyographic and affective responses of episodic tension-type headache patients and headache-free controls during stressful task performance

Thirty-four subjects meeting diagnostic criteria for episodic tension-type headache and 42 who rarely experienced headaches participated in two laboratory sessions in which cephalic electromyographic (EMG) activity, electrodermal activity, heart rate, and finger temperature were recorded. Subjects performed relaxation, choice reaction time, psychomotor tracking, voluntary muscle contraction, and cold pressor tasks. Headache subjects showed significantly greater EMG activity than controls during baseline and stressful task performance. During relaxation, both groups reduced EMG activity from baseline levels, and there was no significant difference in EMG level between the groups during relaxation. Headache subjects reported higher levels of subjective anxiety, depression, anger, and stress than controls. Headache subjects also reported higher levels of pain than controls, and headache subjects reported greater pain during stressful task performance relative to baseline and recovery periods.This research was supported by NIH Grant R01-NS-25114.