Studies on the sexual behaviour, haematology and spermatogenesis of male rabbits infected with Trypanosoma brucei brucei

A total of 24 crossbreed buck rabbits (New Zealand White × chinchilla) were used to evaluate the effect of experimental infection with Trypanosoma brucei on symptoms, sexual behaviours, haematology and spermatogenesis. The rabbits were divided into two groups (A and B) of 12 rabbits each. Group A rabbits were infected with 1.25 × 10⁶ of T. brucei, whereas group B served as the uninfected control. The trypanosomes were detectable in the blood of all the infected bucks by day 7 post-infection (PI) with mean pre-patent period of 4.7 ± 0.85 days. The red blood cell (RBC) and packed cell volume (PCV) decreased significantly (P < 0.05) from day 8 to 28 PI. The values however improved from day 36 PI and were similar to the uninfected control. The reverse was the case of parasitaemia. Two rats died at the peak of the decrease in RBC and PCV and increase in parasitaemia. There was also significant (P < 0.05) loss in live and testis weights, reduced libido and impaired spermatogenesis in the infected group. The infected bucks showed clinical signs similar to that reported in other trypanosome-infected animals. It is concluded that susceptibility of crossbreed rabbits usually kept in Africa to pathogenic trypanosomes is characterised by an acute stage manifested by anaemia, high parasitaemia and death and chronic stage manifested by improved PCV and RBC, very low parasitaemia but high tissue damage and low productivity. Control of this disease in endemic areas for purpose of commercial rabbit production is advocated.     

Comparison of hospitalization rates in patients with community-acquired pneumonia treated with 10 days of telithromycin or clarithromycin

SUMMARY

Aims: To compare the impact on hospitalization rates and the clinical efficacy of oral telithromycin and clarithromycin treatment in patients with community-acquired pneumonia (CAP).

Patients and methods: Outpatients aged >18 years (n?=?448) with CAP were enrolled in a randomized, double-blind, multinational study and received telithromycin 800?mg once daily (n?=?224) or clarithromycin 500?mg twice daily (n?=?224) for 10 days. The primary outcome measure was clinical efficacy at post-therapy/test of cure (Days 17–24) in the per-protocol population. Frequency of CAP-related hospitalizations, physician visits/tests/procedures, and additional respiratory tract infection-related antibacterial use were compared by treatment group (intent to treat population) up to the late post-therapy visit (Days 31-36). Study investigators who were blinded to the treatment arm assessed whether hospital admissions were CAP related or not. Hospitalization costs (US$) associated with telithromycin and clarithromycin treatment were compared.

Results: Per-protocol clinical cure rates for telithromycin and clarithromycin were statistically equivalent (88.3% [143/162] vs 88.5% [138/156] - difference: ?0.2%; 95% CI: ?7.8, 7.5). There were four CAP-related hospitalizations (1.8 events/100 patients) among patients treated with telithromycin vs eight (3.6 events/100 patients) among clarithromycin patients (p?=?0.281). The total number of CAP-related hospital days for telithromycin and clarithromycin patients was 23 vs 64 days (10.3 vs 28.6 days/100 patients), respectively (p?=?0.177). CAP-related hospitalization costs per 100 telithromycin and clarithromycin patients were $20360 vs $70567, respectively (difference: ?25182; 95% CI: ?49531; 9168).

Conclusions: This study demonstrates that telithromycin is an effective therapy for outpatients with CAP. There were no significant differences in hospitalization rates between treatments; however, a tendency towards a numerically reduced number of hospitalizations/days required in hospital among telithromycin patients was observed. This could potentially translate into reduced hospitalization costs for telithromycin vs clarithromycin in the treatment of CAP.     

A technique for isolating heterophils from blood of orange-winged Amazon parrots (Amazona amazonica amazonica)

Blood samples from adult orange-winged Amazon parrots (Amazona amazonica amazonica) were collected to develop a rapid and efficient technique for isolating pure populations of morphologically intact and functional heterophils. In addition, normal haematological parameters for the orange-winged Amazon parrots (n=20) were established and found to be within the reported range of other Amazon species. Heterophil isolation (n=16) was maximally achieved by concentrating the white blood cells with 3% hetastarch prior to running the sample through a polysucrose and disodium diatrizoate centrifugation. The isolation procedure yielded an average heterophil recovery of 61.9%, the purity exceeded 92.6% and viability was 98.9%. Cell integrity was evaluated utilising flow cytometry, cytochemistries, and light microscopy. In this study, isolated heterophils exhibited morphological and cytochemical characteristics similar to whole blood heterophils and were phagocytically active. The results of this study demonstrate that an intact, viable and functionally active heterophil population can successfully be isolated from relatively small volumes of blood and that these cell populations can be further studied employing in vitro bioassaying techniques.     

Routine laboratory analysis for preclinical research in the pharmaceutical industry in Italy: An overview

Last year, the GEET (Italian Association for Haematology and Haematochemistry in Toxicology), which covers most pharmaceutical companies and contract laboratories in Italy, carried out an explorative survey on the analytical procedures commonly used for measuring haematological and clinicochemical parameters in laboratory animals.The aim of this survey was to check the differences between methods and procedures in order to evaluate a potential standardisation among laboratories. The GEET members provided information on the experimental procedures employed and parameters evaluated in their Research Laboratories for dog and rat samples.The variables considered in this paper are blood collection (fasting, anaesthesia, site of withdrawal, anticoagulants), urine collection (water load, preservatives), nature of sample, sample storage, analytical methods and equipment.     

Effects of fasting on haematology and clinical chemistry values in the rat and dog

Many regulatory toxicity guidelines and the recommendation of AACC-DACC/ASVCP joint task force of the USA on clinical pathology testing require overnight fasting for rats and non-rodents before blood sampling. However, the reason why animals must be fasted before blood sampling is unclear in toxicology studies.Fasting, one of many preanalytical conditions, can lead to false low or high values, which in turn may lead to misinterpretation of test compound effects in toxicological studies. This paper reviews the literature with respect to fasting, and reports on our own studies, in the hope of increasing the awareness among investigators of these problems.Haematocrit values and plasma chemistry values in blood obtained from rats and dogs following fasting were compared with unfasted animals. In male F344 rats, after 16 h fasting, body weight decreased. Increases in aspartate aminotransferase (AST)/glutamic oxaloacetic transaminase (GOT) and decreases of plasma alkaline phosphatase (ALP), total cholesterol (CHO), triglycerides (TG), phospholipids (PL), urea nitrogen (UN) and calcium were observed. Haematocrit, plasma alanine aminotransferase (ALT)/glutamic pyruvic transaminase (GPT), total proteins (TP), glucose, and inorganic phosphorus (IP) were unchanged. In male beagle dogs after 16 h fasting, TG, PL, UN, calcium and IP were decreased. Haematocrit, ALP, TP, albumin, glucose, CHO, creatinine, AST/GOT, ALT/GPT, LDH and CPK were not changed.Our own studies show that in order to avoid excessive stress to test animals, the fasting period should be decided case by case, and not made uniform in toxicology studies. It would be useful if regulatory guidelines made some mention of both the effect of feeding, and of stress caused by fasting.     

Study of a new indirect method based on absolute norms of variation to detect autologous blood transfusion

The aim of this study was to investigate an indirect method based on a determination of absolute norms of variation in biological markers that could be used to identify autologous blood transfusion within the framework of the fight against doping. The selection of markers was made from experimental variations obtained during different phases including an increase in training volume at sea level, high altitude training, blood withdrawal and autologous blood reinfusion. The global statistical method was then developed in order to fix absolute norms of variation for each selected marker. The markers selected were haematocrit (Hct), haemoglobin concentration ([Hb]), stimulation index (Off-hr) and the absolute norms of variation (normΔ) established for a maximal 15 days period were normΔHct_0–15 >6%, normΔ[Hb]_0–15 >4% and normΔOff-hr_0–15 >20%. From analyses between two blood samples spaced at an interval of maximum 15 days, this method allows to show “abnormal” variation when a variation for one of the selected markers is strictly superior to the absolute norms of variation established. The legal framework for an immediate application of this method could be that of the internal regulations implemented by each international federation in accordance with the health policy in vigour.     

Normal haematology of captive saker falcons (Falco cherrug)

A complete haematological study was carried out on 25 clinically normal captive female saker falcons (Falco cherrug) in order to establish normal haematology reference values for the species. The results are compared with values obtained in captive peregrine falcons.     

Erythropoietin

Endocrinology is rarely seen as having any great contribution to make to haematology, other than in a few specialist areas. The enormous expansion of knowledge in both subjects in recent years has begun to challenge this perception as more areas of interaction between the two disciplines become clear. The role of erythropoietin and the interactions involved in the immune response have been particularly interesting to haematologists, and have generated a greater awareness of the potential role of hormones in haematological processes.The effects of haematological factors on the reproductive system or the effects of growth hormone, prolactin and insulin-like growth factors on haemopoiesis have also shown the potential for many more examples of interaction.It is now quite obvious that many hormonal systems need to be considered as areas of haematological interest and that a growing field of study is rapidly revealed which may hold the key to a clearer understanding of the mechanisms underlying many haematological processes.Originally presented at ECCP 93.