Trypanosoma lewisi: Cell populations and antibody formation in riboflavin deficient rats

Summary The influence of riboflavin deficiency on severity and duration of parasitemia was studied in Trypanosoma lewisi infected rats.The host dietary groups were: (1) complete or full complement; (2) riboflavin-deficient, and (3) pair-fed or calorically restricted. In all dietary groups, trypomastigotes appeared in peripheral tail blood of all inoculated rats after 7-day incubation periods. Riboflavin-deficient rats and pair-fed controls rats showed greater numbers of parasites than control-diet rats throughout the infection. The maximum parasitemia was on day 14 in control-diet rats; day 16 in riboflavin-deficient rats, and day 14 in pair-fed control rats. Parasitemia in riboflavin-deficient animals lasted 4 or more days longer than in the other two dietary groups.The average coefficients of variation in body length of trypomastigotes indicated that the formation of the reproduction inhibiting antibody (ablastin) was delayed seven days in riboflavin-deficient animals as compared with that in pair-fed and normal control animals.     

Serum concentrations of oestradiol-17beta, progesterone, relaxin and chorionic gonadotrophin during blastocyst implantation in natural pregnancy cycle and in embryo transfer cycle in the rhesus monkey

The present study was undertaken to assess the temporal association between the profiles of serum concentrations of oestradiol-17beta, progesterone, chorionic gonadotrophin (CG) and relaxin in pregnancies established naturally, and after embryo transfer, as well as in failed pregnancies in rhesus monkeys. In naturally mated cycles (group 1) a conception rate of 75% was obtained. In group 1, the mean day of CG detection in serum was 11.5 +/- 1.9 day post-ovulation, and for relaxin, 9.0 +/- 2.5 day post-ovulation. In group 2, embryo transfer to synchronous, non-mated surrogate recipients was performed; seven embryo transfer cycles yielded three pregnancies which were allowed to continue to term and normal infants were delivered. In embryo transfer cycles the mean day of CG detection was 14.8 +/- 1.8 day post- ovulation, and for relaxin, 11.4 +/- 2.6 day post-ovulation. A delay of about 3 days was observed in the appearance in circulation of CG (P < 0.05) and also of relaxin (P < 0.05) between natural mated and embryo transfer conception cycles. Significant differences (P < 0.05 for progesterone and P < 0.03 for oestradiol) were obtained for the areas under the curves for progesterone and oestradiol between days 12 and 16 in conception cycles compared with failed pregnancies. These data provide the first observation of the normal hormonal signals associated with maternal recognition of transferred embryos during the peri- implantation period, and suggest that the use of such an experimental primate embryo transfer model may help to elucidate components of maternal and embryonic signal-response mechanisms during embryo implantation.      

A rapid microagglutination test for the diagnosis of Legionella pneumophila (serogroup 1) infection

A rapid microagglutination test has been developed which can be performed in 30 minutes. Ninety-seven percent of 96 patients diagnosed as having Legionella pneumophila (serogroup 1) infection by indirect immunofluorescence were also detected by the rapid microagglutination test.     

Comparison of the response of primary human peripheral blood mononuclear phagocytes from different donors to challenge with model polyethylene particles of known size and dose

The response of primary human peripheral blood mononuclear phagocytes to challenge with polyethylene particles of known size and dose was evaluated. Particles with mean sizes of 0.21, 0.49, 4.3, 7.2, and 88 microm were co-cultured with cells for 24 h prior to the assessment of cell viability and production of the osteolytic mediators IL-1beta, IL-6, TNFalpha, GM-CSF and PGE2. All particle fractions were evaluated at particle volume (microm3) to cell number ratios of 10:1 and 100:1 which were previously identified as being the most biologically active and clinically relevant. The heterogeneity of human individuals was clearly evident both in the profile and the magnitude of the response of the donors evaluated in this study (the response of donor 5 being 2- to 15-fold lower than that of the other donors). Only the sub-micrometre particles stimulated significantly enhanced cytokine secretion at the ratios tested: mean particle sizes of 0.49 and 0.21 microm being the most biologically active. Macrophages stimulated with particles outside this size range produced considerably lower levels of mediator. These results compared favourably with the results of earlier studies, which demonstrated that particles within the phagocytosable size range (0.1-10 microm) were the most biologically active. These results, therefore, confirm earlier findings and suggest that the size and volume of polyethylene particles are critical factors in macrophage activation. Furthermore, they suggest that the heterogeneity of human individuals may be another important factor in determining implant life and could provide the basis for a valuable diagnostic tool to identify those patients most at risk of implant loosening.     

Clinical and cost-effectiveness of a new nurse-led continence service: a randomised controlled trial

BACKGROUND: Continence services in the UK have developed at different rates within differing care models, resulting in scattered and inconsistent services. Consequently, questions remain about the most cost-effective method of delivering these services. AIM: To evaluate the impact of a new service led by a continence nurse practitioner compared with existing primary/secondary care provision for people with urinary incontinence and storage symptoms. DESIGN OF STUDY: Randomised controlled trial with a 3- and 6-month follow-up in men and women (n = 3746) aged 40 years and over living in private households (intervention [n = 2958]; control [n = 788]). SETTING: Leicestershire and Rutland, UK. METHOD: The continence nurse practitioner intervention comprised a continence service provided by specially trained nurses delivering evidence-based interventions using predetermined care pathways. They delivered an 8-week primary intervention package that included advice on diet and fluids; bladder training; pelvic floor awareness and lifestyle advice. The standard care arm comprised access to existing primary care including GP and continence advisory services in the area. Outcome measures were recorded at 3 and 6 months post-randomisation. RESULTS: The percentage of individuals who improved (with at least one symptom alleviated) at 3 months was 59% in the intervention group compared with 48% in the standard care group (difference of 11%, 95% CI = 7 to 16; P<0.001) The percentage of people reporting no symptoms or 'cured' was 25% in the intervention group and 15% in the standard care group (difference of 10%, 95% CI = 6 to 13, P = 0.001). At 6 months the difference was maintained. There was a significant difference in impact scores between the two groups at 3 and 6 months. CONCLUSIONS: The continence nurse practitioner-led intervention reduced the symptoms of incontinence, frequency, urgency and nocturia at 3 and 6 months; impact was reduced; and satisfaction with the new service was high.     

Genotypic variation in the Bordetella pertussis virulence factors pertactin and pertussis toxin in historical and recent clinical isolates in the United Kingdom

The reemergence of pertussis has been reported in several countries despite high vaccination coverage. Studies in The Netherlands and Finland have investigated polymorphism in the genes coding for two important virulence factors of Bordetella pertussis, pertactin and pertussis toxin, and identified the emergence and subsequent dominance in circulating strains of pertactin and toxin variants not found in the whole-cell vaccine (WCV). The study described here investigated whether such variation had occurred in the United Kingdom, which presently has low levels of pertussis. Sequence analysis of the genes for pertactin (prnA) and the pertussis toxin S1 subunit (ptxA) among isolates of B. pertussis from 285 United Kingdom patients, from 1920 to 1999, revealed three prnA variants, prnA(1), prnA(2), and prnA(3), and two ptxA variants, ptxA(1) and ptxA(2), showing differences in nucleic acid sequence. The proportion of pertactin gene types not included in the United Kingdom WCV, i.e., prnA(2) and prnA(3), has increased in recent years and was found in 21 of 86 (24%) strains from the 1980s and 56 of 105 (53%) strains from the 1990s. To date, the presence of these nonvaccine prnA types has not been associated with a resurgence of pertussis in the United Kingdom. The distribution of prnA and ptxA types in The Netherlands, Finland, and the United Kingdom in the 1990s is distinct. The most striking difference in the United Kingdom isolates is that all 105 of the most recent circulating strains (from 1998 to 1999) are of a pertussis toxin type found in the United Kingdom WCV, i.e., ptxA(1).