Toxins produced by arthropod parasites: Salivary gland proteins of human body lice and venom proteins of chelonine wasps

A review is presented of our ongoing research projects on the protein components of the saliva of human body lice and of the non-paralyzing venom of wasps in the subfamily Cheloninae. Sodium dodecyl sulfate-polyacryamide gel electrophoretic analysis of lice salivary gland proteins showed a predominance of high and intermediate mol. wt proteins. Immunoblotting with a low titer polyclonal antiserum to lice salivary proteins indicated that some, but not all, of the predominant high mol. wt salivary gland proteins are injected into the host during feeding. The venom of a Chelonus sp. wasp contains a chitinase, and a 33,000 mol. wt protein with a primary structure composed mostly of a series of 12 tandem repeats of a 14-residue sequence. The N-terminus of this protein and its homologs in a related species of Ascogaster share a conserved adjacent pair of acidic residues. Epitope mapping/immunoprecipitation experiments now in progress will provide information on which linear motifs are on the surface of the protein, and will thereby provide information on the tertiary structure of the protein.     

Emphysema in the renal allograft

Two diabetic patients in whom emphysematous pyelonephritis developed after renal transplantation are described. Clinical recognition of this unusual and serious infection is masked by the effects of immunosuppression. Abdominal radiographic, ultrasound, and computed tomography findings are discussed. The clinical presentation includes urinary tract infection, sepsis, and acute tubular malfunction of the allograft in insulin-dependent diabetics.     

Fate of vascularized and nonvascularized autografts

Controlled laboratory data demonstrate biologic and mechanical characteristics of orthotopically placed canine ulnar autografts. The pattern of bone repair was similar in vascular and nonvascular ulnar grafts beginning with resorption followed by appositional reactive bone formation. The time intervals in the sequence were accelerated in the vascularized grafts. Both the strength and stiffness of the vascularized grafts were found to be significantly greater in Groups studied from six weeks to six months postoperation. There was no statistical difference between the grafts for mechanical testing performed on dogs either one week or one year postoperation. The vascularized ulnar bone grafts fared better than comparably sized nonvascularized grafts and were more rapidly repaired. The mechanical testing demonstrated superior strength and stiffness of the vascularized grafts throughout the repair process.     

Tranexamic acid and early saphenous vein graft patency in conventional coronary artery bypass graft surgery: a prospective randomized controlled clinical trial

OBJECTIVE: Use of antifibrinolytic agents reduces the risk of bleeding and decreases the need for blood product use in patients undergoing cardiac surgery. The purpose of this study was to determine whether perioperative use of tranexamic acid decreases the rate of saphenous vein graft patency in the early postoperative period after conventional coronary artery bypass grafting surgery. METHODS: A total of 312 patients scheduled for elective coronary artery bypass grafting surgery with cardiopulmonary bypass were randomized to receive either tranexamic acid 100 mg/kg (n = 147) or placebo (n = 165) in a double-blinded fashion before the initiation of cardiopulmonary bypass. Saphenous vein graft patency was assessed with magnetic resonance imaging 5 to 30 days after surgery. RESULTS: Both groups were comparable with respect to baseline demographic data and surgical characteristics. A total of 237 (76%) patients underwent magnetic resonance imaging assessment. A total of 297 saphenous vein grafts were performed and 253 (85.2%; 95% confidence interval, 83.5%-86.9%) were seen in the tranexamic acid group, and 265 saphenous vein grafts were performed and 231 (87.2%; 95% confidence interval, 85.5%-88.9%) were seen in the placebo group (P = .4969). The blood loss and blood product transfusion rates in the tranexamic acid group were significantly lower than in the placebo group. There was no difference between groups with respect to postoperative morbidity and mortality. CONCLUSIONS: The administration of tranexamic acid before cardiopulmonary bypass did not seem to compromise early venous graft patency rates but reduced perioperative blood product transfusion rates. Consequently, tranexamic acid could be advocated for routine use in patients undergoing conventional coronary artery bypass grafting surgery.     

Late benefits 10-18 years after drug therapy for infection with Schistosoma haematobium in Kwale District, Coast Province, Kenya

Late benefits of remote antischistosomal therapy were estimated among long-term residents of an area with high transmission of Schistosoma haematobium (Msambweni, Kenya) by comparing infection and disease prevalence in two local adult cohorts. We compared 132 formerly treated adults (given treatment in childhood or adolescence > or = 10 years previously) compared with 132 age- and sex-matched adults from the same villages who had not received prior treatment. The prevalence of current infection, hematuria, and ultrasound bladder abnormalities were significantly lower among the previously treated group, who were found to be free of severe bladder disease. Nevertheless, heavy infection was equally prevalent (2-3%) in both study groups, and present rates of hydronephrosis were not significantly different. Therapy given in childhood or adolescence appears to improve risk for some but not all manifestations of S. haematobium infection in later adult life. Future prospective studies of continued treatment into adulthood will better define means to obtain optimal, community-based control of S. haematobium-related disease in high-risk locations.     

Effectiveness of a school-based intervention to increase health knowledge of cardiovascular disease risk factors among rural Mississippi middle school children

BACKGROUND: Few school-based interventions have been evaluated to assess health awareness among children in rural southern areas. The purpose of this controlled investigation was to increase health awareness among middle school-aged children residing in a racially diverse rural community in Mississippi. METHODS: This investigation assessed health knowledge before and after a 16-week school-based intervention in 205 fifth-grade students. Height, weight, BMI, body composition, waist circumference, dietary intake, blood lipids and lipoprotein concentrations, blood glucose concentrations, and resting blood pressure were measured to enhance student awareness of cardiovascular disease risk factors. Values in the intervention school were compared with those obtained simultaneously in a control school within the same community. RESULTS: The school-based intervention was effective in increasing health knowledge in the intervention as compared with the control school. Secondarily, it was effective in improving certain dietary behaviors. Utilizing health care professionals in the classroom to teach students appropriate lifestyles and actually measuring cardiovascular risk factors to increase awareness among students was effective in increasing overall health knowledge. CONCLUSIONS: Health knowledge of rural adolescents can be increased through partnerships with schools and multidisciplinary teams of health care professionals. Ongoing efforts to reduce childhood obesity and cardiovascular disease risk factors are urgently needed, and information obtained during this investigation may be used in planning school-based interventions in other diverse, rural communities.     

Mitochondrial DNA control region sequences from Nairobi (Kenya): inferring phylogenetic parameters for the establishment of a forensic database

Large forensic mtDNA databases which adhere to strict guidelines for generation and maintenance, are not available for many populations outside of the United States and western Europe. We have established a high quality mtDNA control region sequence database for urban Nairobi as both a reference database for forensic investigations, and as a tool to examine the genetic variation of Kenyan sequences in the context of known African variation. The Nairobi sequences exhibited high variation and a low random match probability, indicating utility for forensic testing. Haplogroup identification and frequencies were compared with those reported from other published studies on African, or African-origin populations from Mozambique, Sierra Leone, and the United States, and suggest significant differences in the mtDNA compositions of the various populations. The quality of the sequence data in our study was investigated and supported using phylogenetic measures. Our data demonstrate the diversity and distinctiveness of African populations, and underline the importance of establishing additional forensic mtDNA databases of indigenous African populations.