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Biomedical subjects

M Visser

Publications and source records attributed to M Visser.

At least 37 records · Page 2Linked to original sources
PubMed2002

The prediction of visceral fat by dual-energy X-ray absorptiometry in the elderly: a comparison with computed tomography and anthropometry.

INTRODUCTION: Effective methods for assessing visceral fat are important to investigate the role of visceral fat for the increased health risks in obesity. Techniques for direct measurement of soft tissue composition such as CT or MRI are expensive, time-consuming or require a relatively high radiation dose. Simple anthropometric methods, such as waist-to-hip ratio, waist circumference or sagittal diameter are widely used. However, these methods cannot differentiate between visceral and subcutaneous fat and are less accurate. The aim of the present study is to investigate whether the dual-energy X-ray absorptiometry (DXA) method, possibly combined with anthropometry, offers a good alternative to CT for the prediction of visceral fat in the elderly. METHODS: Subjects were participants in the Health ABC-study, a cohort study of black and white men and women aged 70-79, investigating the effect of weight-related health conditions on disablement. Total body fat and trunk fat were measured by DXA using a Hologic QDR 1500. A 10 mm CT scan at the L4-L5 level was acquired to measure visceral fat and total abdominal fat. Weight, height, sagittal diameter and waist circumference were measured using standard methods. Fat in a manually defined DXA subregion (4 cm slice at the top of iliac crest) at the abdomen was calculated in a sub-group of participants (n=150; 50% male; 45.3% Afro-American/54.7% Caucasian, age 70-79 y). This subregion, the standard trunk region and total fat were used as indicators of visceral fat. RESULTS: Total abdominal fat by DXA (subregion) was strongly correlated with total abdominal fat by CT (r ranging from 0.87 in white men to 0.98 in black women). The DXA subregion underestimated total abdominal fat by 10% compared to the CT slice. The underestimation by DXA was seen especially in people with less abdominal fat. The association of visceral fat by CT with the DXA subregion (r=0.66, 0.78, 0.79 and 0.65 for white and black men and women, respectively) was comparable with the association of the CT measure with the sagittal diameter (r=0.74, 0.70, 0.84 and 0.68). Combining DXA measurements with anthropometry gave only limited improvement for the prediction of visceral fat by CT compared to univariate models (maximal increase of r(2) 4%). CONCLUSION: DXA is a good alternative to CT for predicting total abdominal fat in an elderly population. For the prediction of visceral fat the sagittal diameter, which has a practical advantage compared to DXA, is just as effective.

Abdomen↗
PubMed2002

Efficacy of ivermectin delivered via a controlled-release capsule against small lungworms (Protostrongylidae) in sheep.

To evaluate the efficacy of an ivermectin controlled-release capsule (CRC), which delivers 1.6 mg ivermectin per day intraruminally for 100 days to sheep weighing 40-80 kg (IVOMEC Maximizer CR Capsule for adult sheep, Merial), against small lungworms two studies with 48 naturally infected adult female Merino Landrace sheep were conducted. The sheep were allocated by restricted randomization based on bodyweight to untreated controls or received an ivermectin CRC. Eight sheep per group were necropsied 35, 70 or 105 days post-treatment. Lungworms were recovered by dissection or peptic digestion of the lungs. Baermann/Wetzel technique was used for faecal lungworm larval counts at weekly intervals. The efficacy of treatment was 100% against Dictyocaulus filaria and Protostrongylus rufescens (P < 0.05) at each necropsy day. The efficacy against Protostrongylus brevispiculum, Cystocaulus ocreatus and Neostrongylus linearis increased from 35 to 105 days after administration of the CRC and was found to be 100% (P < 0.01), 96.6% (P < 0.01) or 99% (P < 0.01), respectively, at 105 days post-treatment. The reductions of Muellerius capillaris counts varied and were 96.2% (P < 0.05) at 70 days post-treatment and 44.6% (P > 0.1) at 105 days post-treatment. Faecal lungworm larvae disappeared nearly completely from at least 3 weeks after the ivermectin CRC administration for all protostrongylid species including M. capillaris so that pasture infectivity will be subsequently significantly reduced.

Administration, Oral↗
PubMed2001

Re-evaluation of ivermectin efficacy against equine gastrointestinal parasites.

Two trials were conducted to confirm the efficacy of ivermectin paste against endoparasites of horses. In these trials, 20 ponies were treated with ivermectin oral paste at 200 mcg x kg body weight once on Day 0, and 20 ponies served as unmedicated controls. The animals carried naturally acquired parasite infections as confirmed by pretrial fecal examination. The animals were necropsied for worm recovery on Days 14, 15 or 16. Parasites recovered were identified to species. Horses treated with ivermectin had significantly (P<0.05) fewer (>99.0% reduction) adult small strongyles (Coronocyclus spp including C. coronatus, C. labiatus, C. labratus; Cyathostomum spp including C. catinatum, C. pateratum; Cylicocyclus spp including C. ashworthi, C. elongatus, C. insigne, C. leptostomum, C. nassatus, C. radiatus; Cylicodontophorus bicoronatus; Cylicostephanus spp including C. asymetricus, C. bidentatus, C. calicatus, C. goldi, C. longibursatus, C. minutus; Gyalocephalus capitatus; Parapoteriostomum spp including P. euproctus, P. mettami; Petrovinema poculatum; Poteriostomum spp including P. imparidentatum, P. ratzii) and adult large strongyles (Strongylus edentatus, S. vulgaris; Triodontophorus spp including T. brevicauda, T. serratus; Craterostomum acuticaudatum) than the controls. Ivermectin was also highly effective (94% to >99%, P<0.05-0.01) against Gasterophilus intestinalis larvae, Habronema spp., Oxyuris equi, Parascaris equorum. The data from these two trials confirm that ivermectin paste administered to horses orally at 200mcg x kg(-1) continues to be highly effective for treatment and control of a broad range of small and large strongyle species as well as other species of gastrointestinal parasites.

Administration, Oral↗
PubMed2001

[Roaming through methodology. XXXIV. Limitations of predictive models].

Predictive models can be readily used within the populations in which they were developed but they often give a less than satisfactory performance when applied to another population. The main cause of this poorer performance is the fact that predictive models are often developed and evaluated within one single population. In a lot of cases, the model includes too many predictors (or a small population is used), which increases the chance of overfitting. Both external and internal validation techniques have been developed to evaluate predictive models. The most stringent test is an external validation: the application of the model to a new population. The usability of a predictive model can be evaluated using the receiver operating characteristic (ROC) curve.

Data Interpretation, Statistical↗
PubMed2001

Heat kernel regularization of the effective action for stochastic reaction-diffusion equations.

The presence of fluctuations and nonlinear interactions can lead to scale dependence in the parameters appearing in stochastic differential equations. Stochastic dynamics can be formulated in terms of functional integrals. In this paper we apply the heat kernel method to study the short distance renormalizability of a stochastic (polynomial) reaction-diffusion equation with real additive noise. We calculate the one-loop effective action and its ultraviolet scale dependent divergences. We show that for white noise a polynomial reaction-diffusion equation is one-loop finite in d=0 and d=1, and is one-loop renormalizable in d=2 and d=3 space dimensions. We obtain the one-loop renormalization group equations and find they run with scale only in d=2.

Journal Article↗
PubMed2001

Weight loss from maximum body weight among middle-aged and older white women and the risk of hip fracture: the NHANES I epidemiologic follow-up study.

Although weight loss increases bone loss and hip fracture risk in older women, little is known about the relation between weight loss in middle-aged women and subsequent hip fracture risk. The objective of this study was to determine the association between weight loss from reported maximum body weight in middle-aged and older women and the risk of hip fracture. Data were from a nationally representative sample of 2180 community-dwelling white women aged 50-74 years from the Epidemiologic Follow-up Study of the first National Health and Nutrition Examination Survey (NHEFS). In this prospective cohort study, incident hip fracture was ascertained during 22 years of follow-up. The adjusted relative risks associated with weight loss of 10% or more from maximum body weight were elevated for both middle-aged (RR 2.54; 95% CI 1.10-5.86) and older women (RR 2.04; 95% CI 1.37-3.04). For both ages combined, women in the lowest tertile of body mass index at maximum who lost 10% or more of weight had the highest risk of hip fracture (RR 2.37; 95% CI 1.32-4.27). Weight loss from maximum reported body weight in women aged 50-64 years and 65-74 years increased their risk of hip fracture, especially among those who were relatively thin. Weight loss of 10% or more from maximum weight among both middle-aged and older women is an important indicator of hip fracture risk.

Aged↗
PubMed2001

Species of flea (siphonaptera) infesting pets and hedgehogs in Germany.

The species of flea infesting pets and hedgehogs in Germany were investigated through a survey of small animal practitioners throughout the country who were asked to collect specimens at their veterinary practices. A total of 625 veterinarians/veterinary practices responded and provided 2445 intact anti identifiable flea specimens. These fleas originated from 294 dogs (795 fleas), 334 cats (1152 fleas), 76 hedgehogs (481 fleas), five domestic rabbits (10 fleas), one golden hamster (four fleas) and one ferret (three fleas). Dogs were found to be infested with Archaeopsylla erinacei, Chaetopsylla globiceps, Ctenocephalides canis, Ctenocephalides felis, Hystrichopsylla talpae, Nosopsyllus fasciatus, Paraceras melis and Pulex irritans. From cats, Archaeopsylla erinacei, Ceratophyllus gallinae, Ceratophyllus garei, Ctenocephalides felis, Ctenophthalmus assimilis, Hystrichopsylla talpae, Monopsyllus sciurorum, Nosopsyllus fasciatus, Spilopsyllus cuniculi and Typhloceras poppei were collected. In both dogs and cats the most prevalent species were Ctenocephalides felis (78.9% and 91.6%, respectively) and Archaeopsylla erinacei (21.1% and 12.6%, respectively) followed by Ctenocephalides canis in dogs (5.8%) and Hystrichopsylla talpae in cats (1.2%). The fleas isolated from rabbits were Ctenocephalides felis, Hystrichopsylla talpae and Spilopsyllus cuniculi. Nosopsyllus fasciatus and Ctenocephalides felis were recovered from the golden hamster and the ferret, respectively. The hedgehogs were found to be infested with Archaeopsylla erinacei, Ceratophyllus gallinae and Ctenocephalides felis.

Animals↗
PubMed2001

Calibration and validation of an air-displacement plethysmography method for estimating percentage body fat in an elderly population: a comparison among compartmental models.

BACKGROUND: The use of hydrostatic weighing (HW) to measure body composition in the elderly can be difficult and is based on the assumption of constancy of body compartments. OBJECTIVE: We calibrated and validated a new air-displacement plethysmography (AP) method for measuring body composition in the elderly. DESIGN: A 4-compartment equation for calculating percentage body fat (%BF) that used body density (D(b)), total body water, and bone mineral content was used as the criterion for evaluating %BF estimated by the 2- and 3-compartment models. D(b) was measured by HW [D(b(HW))] and by use of the AP instrument [D(b(AP))] in 30 elderly men and 28 elderly women aged 70-79 y. RESULTS: D(b(AP)) was not significantly different from D(b(HW)). However, analysis of variance showed a significant two-way interaction between sex and compartment model (P < 0.02), indicating that the comparisons between the sexes were different across all compartment models. The %BF calculated for the women was significantly higher than that calculated for the men by both HW and AP and for all compartment models. CONCLUSION: Our data indicate that D(b(AP)) was not significantly different from D(b(HW)). Although differences were seen in %BF between the sexes, we observed no significant differences among the compartment models within each sex for this group of older individuals.

Adipose Tissue↗
PubMed2001

Attenuation of skeletal muscle and strength in the elderly: The Health ABC Study.

Although loss of muscle mass is considered a cause of diminished muscle strength with aging, little is known regarding whether composition of aging muscle affects strength. The skeletal muscle attenuation coefficient, as determined by computed tomography, is a noninvasive measure of muscle density, and lower values reflect increased muscle lipid content. This investigation examined the hypothesis that lower values for muscle attenuation are associated with lower voluntary isokinetic knee extensor strength at 60 degrees/s in 2,627 men and women aged 70-79 yr participating in baseline studies of the Health ABC Study, a longitudinal study of health, aging, and body composition. Strength was higher in men than in women (132.3 +/- 34.5 vs. 81.4 +/- 22.0 N x m, P < 0.01). Men had greater muscle attenuation values (37.3 +/- 6.5 vs. 34.7 +/- 7.0 Hounsfield units) and muscle cross-sectional area (CSA) at the midthigh than women (132.7 +/- 22.4 vs. 93.3 +/- 17.5 cm(2), P < 0.01 for both). The strength per muscle CSA (specific force) was also higher in men (1.00 +/- 0.21 vs. 0.88 +/- 0.21 N x m x cm(-2)). The attenuation coefficient was significantly lower for hamstrings than for quadriceps (28.7 +/- 8.7 vs. 41.1 +/- 6.9 Hounsfield units, P < 0.01). Midthigh muscle attenuation values were lowest (P < 0.01) in the eldest men and women and were negatively associated with total body fat (r = -0.53, P < 0.01). Higher muscle attenuation values were also associated with greater specific force production (r = 0.26, P < 0.01). Multivariate regression analysis revealed that the attenuation coefficient of muscle was independently associated with muscle strength after adjustment for muscle CSA and midthigh adipose tissue in men and women. These results demonstrate that the attenuation values of muscle on computed tomography in older persons can account for differences in muscle strength not attributed to muscle quantity.

Adipose Tissue↗
PubMed2001

Determinants of bone mineral density in older men and women: body composition as mediator.

This study aimed to assess the relative importance of several determinants of bone mineral density (BMD) and to examine to what extent these potential determinants influence total hip BMD through body composition. The study population consisted of 522 participants (264 women and 258 men) of the Longitudinal Aging Study Amsterdam (LASA), aged 65 years and over, and living in Amsterdam and its vicinity. BMD of the total hip was measured using dual-energy X-ray absorptiometry (DXA). Potential determinants of BMD were age, weight change since age 25 years, lifestyle factors, chronic diseases, medication use, and hormonal factors. Potential mediators between the possible determinants and BMD were two measures of body composition: fat mass (FM) and appendicular muscle mass (AMM). Multiple regression analyses including all potential determinants in one model without body composition identified age, weight change, walking activity, and sex hormone-binding globulin (SHBG) as independent determinants for total hip BMD in women. In men, current smoking, participation in sports, and parathyroid hormone (PTH) concentration were independently associated with total hip BMD. When total hip BMD was regressed on the potential determinants and each measure of body composition, it appeared that FM, and to a lesser extent, muscle mass (MM), were independently related to BMD. In women, adjustment for FM reduced the strength of the associations of weight change, walking activity, and SHBG with total hip BMD. Adjustments for MM did not influence the associations between the determinants and BMD. In men, neither FM nor MM appeared to play a mediating role between the determinants and BMD. It can be concluded that (1) FM and MM are strong independent determinants of total hip BMD and that (2) FM possibly plays a mediating role in the association of weight change, walking activity, and SHBG with total hip BMD in women.

Adipose Tissue↗
PubMed2001

Low-grade systemic inflammation in overweight children.

OBJECTIVE: Human adipose tissue expresses and releases the proinflammatory cytokine interleukin-6, potentially inducing low-grade systemic inflammation in persons with excess body fat. To limit potential confounding by inflammation-related diseases and subclinical cardiovascular disease, we tested the hypothesis that overweight is associated with low-grade systemic inflammation in children. DESIGN AND SETTING: The third National Health and Nutrition Examination Survey, 1988-1994, a representative sample of the US population. PARTICIPANTS: A total of 3512 children 8 to 16 years of age. OUTCOME MEASURES: Elevated serum C-reactive protein concentration (CRP; >/=.22 mg/dL) and white blood cell count (10(9) cells/L). RESULTS: Elevated CRP was present in 7.1% of the boys and 6.1% of the girls. Overweight children (defined as having a body mass index or a sum of 3 skinfolds (triceps, subscapula, and supra-iliac) above the gender-specific 85th percentile) were more likely to have elevated CRP than were their normal-weight counterparts. After adjustment for potential confounders, including smoking and health status, the odds ratio (OR) was 3.74 (95% confidence interval [CI]: 1.66-8.43) for overweight boys and the OR was 3.17 (95% CI: 1.60-6.28) for overweight girls, based on the body mass index. Based on the sum of 3 skinfolds, these ORs were 5.11 (95% CI: 2.36-11.06) and 2.89 (95% CI: 1.49-5.59) for boys and girls, respectively. Overweight was also associated with statistically significant higher white blood cell counts. The results were similar when restricted to healthy, nonsmoking, nonestrogen-using children. CONCLUSIONS: In children 8 to 16 years of age, overweight is associated with higher CRP concentrations and higher white blood cell counts. These findings suggest a state of low-grade systemic inflammation in overweight children. inflammation, obesity, children.

Adipose Tissue↗
PubMed2001

[Escherichia coli eradication from the blader urine by amoxicillin-sulbactam. Intrinsic activity of the inhibitor].

RATIONALE: At urine concentrations obtained after the oral administration of amoxicillin-sulbactam (500/500 mg) this combination inhibits roughly 90% of Escherichia coli and Proteus mirabilis strains. AIMS: To administer amoxicilin-sulbactam 875/125 mg and to determine: a) minimum inhibitory concentration (MIC) of sulbactam for E. coli and P. mirabilis; b) urine inhibitory titres power (UIT) against amoxicillin-resistant E. coli or P. mirabilis; c) urine concentrations of sulbactam; and to verify whether sulbactam 125 mg as single drug, attains a high enough UIT to support the intrinsic action of the inhibitor; and to compare the activity of amoxicillin-sulbactam and amoxicillin-clavulanate and that of sulbactam and clavulanate. METHODS: Twelve healthy volunteers received a single oral dose of amoxicillin-sulbactam 875/125 mg or amoxicillin-clavulanate 875/125 mg, according to a randomized cross-over design. Urine samples were drawn at: 0 (basal), 2, 4, and 6 hours after dosing. Urine pH, specific gravidity and UIP were assessed. Thirty nine strains isolated from urine samples were used: 30 TEM-1 producing E. coli strains and 3 extended spectrum CTX-M-2 betalactamase-producing E. coli; and 6 P. mirabilis resistant to both combinations. In 6 healthy volunteers, sulbactam 125 mg was administered orally and UIT against E. coli (MIC amoxicillin > 2048 mg/l) was assessed. RESULTS AND DISCUSSION: MIC-90 for amoxicillin plus sulbactam or clavulanate were similar to those for sulbactam or clavulanate alone, without any difference attributable to the chemical composition of the urine. The activity of amoxicillin plus the inhibitors could be due, not only to the inhibition of betalactamase but also to the intrinsic effect of the inhibitor. Both combinations showed an equivalent inhibitory activity. Two-hour UIT remained high for the entire 6-h evaluation period. Sulbactam concentration far exceed sulbactam MIC for the 6h-period, inhibiting urine E. coli. We disagree with the cut-off limit proposed for intermediate values of NCCLS, which, for these antimicrobial are 16/8, a value lower than those obtained in urine samples after the administration of betalactamase inhibitors. This may be an explanation for the beneficial effect of amoxicillin-sulbactam in the recovery of uncomplicated lower urinary tract infections in women when the involved strains were considered resistant by diffusional methods.

Adult↗
PubMed2001

[Multicenter study in southern South America of the in vitro activity of telithromycin in strains with defined resistance phenotypes isolated from community-acquired respiratory infections].

Telithromycin was the first ketolide to be approved in Europe and is in the approval process in the United States. It is structurally related to the macrolides; it has a keto group in the C3 position rather than cladinose. A carbamate group is also present at C11-C12. As a result, it has a reduced induction of the MLSB resistance mechanism (erm gene), it is not affected by the flux mechanism (mef gene), it has higher stability at low pH and has increased intrinsic activity compared with clarithromycin and azithromycin. Phase III studies have shown telithromycin to be effective in the treatment of community-acquired upper and lower respiratory tract infections. Its long half-life allows for oral once-daily dosing. From a pharmacokinetic point of view, its activity has been shown to be AUC(24h)/MIC dependent. It is active against bacteria involved in atypical pneumonia. The aim of our study was to determine the activity of telithromycin in isolates with defined resistance phenotypes obtained from community-acquired respiratory tract infections. Twelve centers in Argentina, Chile, Paraguay and Uruguay participated in the study. Each center collected three strains of the following species and resistance patterns: S. pyogenes, S. pneumoniae with resistance or intermediate resistance to oxacillin, erythromycin-resistant S. pneumoniae, clindamycin-resistant S. pneumoniae, oxacillin-susceptible S. aureus, erythromycin-resistant S. aureus, ampicillin-susceptible and -resistant M. catarrhalis and H. influenzae. Agar diffusion susceptibility tests with NeoSensitabs tablets (Rosco, Denmark) were carried out at each center. Isolates were sent to the coordinating center, where MICs were determined using agar microdilution and the Seppala test was used to determine the resistance mechanism to macrolides. The 327 isolates received were susceptible to telithromycin. Eighty percent of the erythromycin-resistant S. pneumoniae isolates were likely resistant due to a flux mechanism, and all those resistant to clindamycin were resistant due to the erm inducible mechanism. Only 20 out of 36 strains of clindamycin-resistant S. pneumoniae and 25 of the 36 ampicillin-resistant H. influenzae strains could be collected, thereby showing that these resistance patterns are less common in the participating South American countries than in other areas. The in vitro activity of telithromycin suggests that it is a promising antibacterial drug for the treatment of community-acquired respiratory tract infections.

Anti-Bacterial Agents↗
PubMed2000

Effects of Psoroptes ovis infection and its control with an ivermectin controlled-release capsule on growing sheep. 2. Evaluation of wool production and leather value.

To evaluate the prophylactic and therapeutic effects of an ivermectin controlled-release capsule (IVM-CRC) on the productivity of growing sheep infested with Psoroptes ovis 24 male and 24 female Merino landrace lambs, 5-6 months old and weighing 21.2-35.0 kg, were used. Sixteen replicates of three animals were formed based on sex and Day 0 body weight. Within each replicate animals were randomly allocated to one of three groups: untreated control; IVM-CRC on Day 0; IVM-CRC on Day 84. For treatment an IVM-CRC for sheep weighing 20-45 kg was used which is designed to deliver ivermectin at a minimum dose of 20 microg/kg/day for 100 days. The lambs were infested with 50-60 P. ovis mites each on days 14 and 21. The animals were shorn on Day 126. After slaughter on Day 127 the quality of the leather produced from their skins was evaluated. The IVM-CRC treatment on Day 0 prevented the establishment of P. ovis. All untreated lambs became infested. The lambs treated with an IVM-CRC on Day 84 became mite-free from Day 112 onwards. The lambs which were treated on Day 0 had significantly (p<0.05) greater clean fleece weight (1.5 kg) and fleece yield (52.1%) than the untreated controls (0.9 kg and 34.1%, respectively) or than lambs treated on Day 84 (1.0 kg and 47.8%, respectively). Clean fleece weight and fleece yield were in the tendency (p=0.055) or significantly (p<0. 001) greater, respectively, for lambs treated on Day 84 than for the untreated controls. The chrome tanned dried crust leather of all untreated controls and six of the 16 lambs treated on Day 84 showed grain surface defects such as discolourations, indurations and coarse, pitted grain. The useful (defect-free) leather size was significantly (p<0.01) higher for the lambs treated on Day 0 (100%) than for the lambs treated on Day 84 (82.7%) and the untreated controls (7.8%). The physical testing revealed that the leather of sheep treated on Day 0 had significantly (p<0.05) higher thickness, elongation break and tear resistance than the leather of both untreated controls and sheep treated on Day 84. There were no significant differences in the physical characteristics of the leather of the untreated controls and the sheep treated on Day 84.

Animals↗
PubMed2000

Effects of psoroptes ovis infection and its control with an ivermectin controlled-release capsule on growing sheep. 1. Evaluation of weight gain, feed consumption and carcass value.

To evaluate the prophylactic and therapeutic effects of an ivermectin controlled-release capsule (IVM-CRC) on the productivity of growing sheep infested with Psoroptes ovis 24 male and 24 female Merino landrace lambs, 5-6 months old and weighing 21.2-35.0 kg, were used. Sixteen replicates of three animals were formed based on sex and Day 0 body weight. Within each replicate animals were randomly allocated to one of three groups: untreated control; IVM-CRC on Day 0; IVM-CRC on Day 84. For treatment an IVM-CRC for sheep weighing 20-45 kg was used which is designed to deliver ivermectin at a minimum dose of 20 microg/kg per day for 100 days. The lambs were infested with 50-60 P. ovis mites each on Days 14 and 21. Mites in skin scrapings were counted on Days 70, 84, 98, 112 and 126. Body weight and feed consumption were measured every 2 weeks from Day 0 to 126. The animals were slaughtered on Day 127 and their carcasses evaluated. The IVM-CRC treatment on Day 0 prevented the establishment of P. ovis. All untreated lambs became infested. The lambs treated with an IVM-CRC on Day 84 became mite-free from Day 112 onwards. The lambs treated on Day 0 had significantly (p<0.05) greater body weight gain from Day 0 to 84 (13.9 kg) and Day 0 to 126 (20.9 kg) than the untreated controls (9.6 and 12.8 kg, respectively) and the sheep treated on Day 84 (8.4 and 14.9 kg, respectively). Feed consumption (Days 0-126) for sheep treated with the IVM-CRC on Day 0 was higher than for sheep treated on Day 84 (p<0.05) and for the untreated controls (p<0.1). The carcasses of sheep treated with the IVM-CRC on Day 0 had significantly (p<0.05) higher warm and cold weights, carcass yield, rib eye area and back fat thickness than the untreated control group and the sheep treated with the IVM-CRC on Day 84. The sheep treated with the ivermectin CRC on either Day 0 or 84 had significantly (p<0.05) better muscle scores and lower muscle pH 1h post-slaughter than the untreated controls. There was no significant (p>0.1) difference between warm and cold carcass weights, carcass yield and rib eye area between sheep treated on Day 84 and untreated controls.

Animals↗
PubMed2000

Synthesis and evaluation of 9,9-dimethylxanthene tricyclics against trypanothione reductase, Trypanosoma brucei, Trypanosoma cruzi and Leishmania donovani.

Derivatives of 9,9-dimethylxanthene were synthesised and evaluated against trypanothione reductase (TR) and in vitro against parasitic trypanosomes and leishmania. High in vitro antiparasitic activity was observed for some derivatives with one compound showing high activity against all three parasites (ED50 values of 0.02, 0.48 and 0.32 microM, for Trypanosoma brucei, Trypanosoma cruzi, and Leishmania donovani, respectively). The lack of correlation between inhibitory activity against TR and ED50 values suggests that TR is not the target.

Animals↗