Rapid reperitonealization and wound healing in a preclinical model of abdominal trauma repair with a composite mesh.

PURPOSE: Peritoneal tissue healing is characterized by the simultaneous repopulation of mesothelial cells and the formation of neoperitoneum. Despite the common use of mesh products for abdominal wall repair, there are few investigations of how these materials may impact the peritoneal healing process. Here, we utilized an animal model of abdominal trauma to specifically investigate the peritoneal healing process in conjunction with a composite (poliglecaprone 25-coated polypropylene) mesh. METHODS: Abdominal wall injury was simulated in New Zealand White rabbits and peritoneal tissue was covered with composite mesh and fixed with peripheral sutures. Animals were sacrificed at regular intervals (up to 28 days) for macroscopic and microscopic evaluation. RESULTS: Mesothelial cells were consistently identified on the surface of the central areas of the implanted mesh as early as 3-5 days after implantation. From day 7 onward, the entire mesh surface was covered by neoperitoneum which matured over the remaining study intervals. Fibroblast ingrowth of the mesh was apparent by day 5 and increased over time, concurrent with fragmentation of the film on the composite mesh. CONCLUSIONS: These results suggest that composite mesh products used for abdominal wall repair do not significantly delay mesothelial repopulation. Study results also support the hypothesis that mesothelial cells involved in healing are derived, at least in part in this model, from free-floating precursor cells located within the peritoneal cavity.

The efficacy of eprinomectin extended-release injection against Hypoderma spp. (Diptera: Oestridae) in cattle.

The efficacy of eprinomectin in an extended-release injection (ERI) formulation was determined in cattle harboring naturally acquired infestations of first- or second- and third-stage larvae of Hypoderma spp. in three studies conducted according to the same protocol in the USA (two studies) and Germany (one study). Thirty cattle sourced from herds with a history of Hypoderma infestation were included in each study. Cattle were formed into replicates of three animals each on the basis of pre-treatment anti-Hypoderma antibody titers. Within replicates each animal was randomly allocated to one of the following treatments: ERI vehicle (control) at 1 mL/50 kg bodyweight, administered once on Day 0; Eprinomectin 5% ERI at 1 mL/50 kg bodyweight (1.0 mg eprinomectin/kg), administered once on Day 0 (when larvae were expected to be first instars); or Eprinomectin 5% ERI at 1 mL/50 kg bodyweight (1.0 mg eprinomectin/kg), administered once when larvae were second or third instars (study dependent, Day 73, 119, or 140). Treatments were administered by subcutaneous injection in front of the shoulder. In all studies, emerging and/or expressed Hypoderma larvae were recovered, speciated, and counted and viability was determined. Eprinomectin LAI treatment was 100% (p<0.05) efficacious against first- and second- or third-stage larvae of Hypoderma bovis (two studies) and Hypoderma lineatum (one study). All animals accepted the treatment well. No adverse reaction to treatments was observed in any animal in any study.

Biomechanical and histological evaluation of abdominal wall compliance with intraperitoneal onlay mesh implants in rabbits: a comparison of six different state-of-the-art meshes.

BACKGROUND: An ideal prosthetic mesh for incisional hernia repair should mimic the anisotropic compliance of the abdominal wall, and at lower loads should exhibit higher distensibility without impairment of safety at higher loads. This study evaluated the biomechanical properties of six meshes in a rabbit model. METHODS: New Zealand white rabbits were used for this study. Two meshes of the same brand (Ethicon Physiomesh™, Bard Composix(®) L/P, Gore Dualmesh(®), Bard Sepramesh(®), Ethicon Proceed(®) or Parietex™ Composite) were implanted into each animal for assessment of intra-abdominal hernia repair, with a total of ten meshes per group. Twelve weeks after implantation, the abdominal walls with ingrown meshes were harvested and examined biomechanically with a plunger test. The mesh-tissue compliance was evaluated by the forces exerted at given displacements and also described through a simple mathematical approximation. Abdominal wall samples were collected for histopathology, cell turnover and morphometry. RESULTS: No mesh-related complications were seen. The adhesion score was significantly higher in Bard Composix(®) L/P and Ethicon Proceed(®) meshes. Significant shrinkage was seen in Gore Dualmesh(®) and Parietex™ Composite meshes. Physiomesh™ exhibited the highest compliance during plunger testing, characterized by lower, more physiological reaction forces against tissue displacement than the competitor meshes. In contrast, the safety modulus was comparable in all groups. Histology showed less collagen and less foreign body reaction in the Physiomesh™ samples contributing to patient's comfort. CONCLUSION: In terms of safety, this study showed no superiority of any single mesh. The comfort modulus however differed, being lowest in the newly developed Physiomesh™.

Forces and deformations of the abdominal wall--a mechanical and geometrical approach to the linea alba.

Force-elongation responses of the human abdominal wall in the linea alba region were determined by tensile tests in which the linea alba was seen to exhibit a nonlinear elastic, anisotropic behavior as is frequently observed in soft biological tissues. In addition, the geometry of the abdominal wall was determined, based on MRI data. The geometry can be specified by principal radii of curvature in longitudinal of approximately 470 mm and in the transverse direction of about 200 mm. The determined radii agree with values found in other studies. Mechanical stresses, deformations and abdominal pressures for load cases above 6% elongation can be related using Laplace's formula and our constitutive and geometrical findings. Results from uni- and biaxial tensile tests can thus be compared using this model. Calculations confirm that abdominal pressures of approximately 20 kPa correspond to related biaxial forces of about 3.4N/mm in the transverse and 1.5 N/mm in the longitudinal direction. Young's moduli can be calculated with respect to the uniaxial as well as the biaxial loading. At these physiological loadings, a compliance ratio of about 2:1 between the longitudinal and transversal directions is found. Young's moduli of about 50 kPa occur in transversal direction and of about 20 kPa in longitudinal direction at transverse and longitudinal strains both in the order of 6%. These findings coincide with results from other investigations in which the properties of the abdominal wall have been examined.

Experimental evaluation of the safety and biocompatibility of a new antireflux prosthesis.

Previous studies have shown that encircling of the esophagogastric junction by a semiabsorbable scarf effectively prevents gastroesophageal reflux. The present study was performed to assess the long-term safety and biocompatibility of this type of scarf. The semiabsorbable scarf was implanted into 20 dogs either laparoscopically or via laparotomy. Pre- and post-operatively, contrast radiography, esophageal manometry, and upper gastrointestinal endoscopy were performed. No cases of perforation, stricture formation or other adverse effects were found after 1 and 2 years. It is concluded that the new type of scarf is without any adverse side-effects. Functional evaluation in reflux patients appears to be warranted.

Induction and maintenance of gastric ulceration in horses in simulated race training.

Gastric ulceration is a prevalent condition of racehorses. A number of models of gastric ulceration have been described, but none mimic the conditions of a horse in training. The objectives of this study were to determine whether gastric ulcers could be induced and maintained in a group of horses in simulated race training. In addition, serum cortisol was measured on a weekly basis to investigate the possibility that stress may be important in the pathogenesis of gastric ulceration. Thirty horses used in the trial were fed Bermuda grass hay and 6 kg of a concentrate diet, and exercised 6 days/week at speed over a distance of 1.6-2.4 km. Serum was collected and gastroendoscopic examinations performed on a weekly basis for the duration of the trial. All horses developed moderate to severe ulceration, and ulcers were maintained for the 56 day period of the trial. Only one horse had signs of abdominal discomfort, which resolved with minimal symptomatic treatment and without the use of anti-ulcer medications. Serum cortisol remained within reference ranges for the duration of the trial. Although there was some variation between the weekly examinations, serum cortisol concentrations were decreased from values obtained at the start of the trial. In this study ulcers developed without the administration of nonsteroidal anti-inflammatory agents or withholding of feed. This model provides a method to study the condition, and to investigate the effects of medications on the healing of ulcers in racehorses.

Effect of omeprazole paste on gastric acid secretion in horses.

In a multicentre trial, 13 cannulated horses were treated orally once daily with a paste that delivered omeprazole at a dose of 4 and 5 mg/kg bwt in a 2-period crossover design to evaluate steady state gastric acid suppression. In each period, basal (unstimulated) and pentagastrin-stimulated gastric output were evaluated at 5-8 h after 5 doses, at 13-16 h after 10 doses, and at 21-24 h after 15 doses. Baseline data for gastric acid secretion were collected once for each horse in the month prior to initiation of omeprazole treatment. The inhibition of gastric acid secretion relative to baseline values, following treatment with omeprazole, were calculated and expressed as per cent. Pharmacokinetic data were also collected in this trial. At 4 mg/kg bwt, the oral paste formulation of omeprazole inhibited both basal and pentagastrin-stimulated gastric acid secretion by 99% at 5-8 h after treatment and by 83% (basal) and 90% (pentagastrin-stimulated) at 21-24 h. Inhibition following the administration of omeprazole at a dose of 5 mg/kg bwt was not significantly greater than when given at 4 mg/kg bwt. The results from this study could possibly lead to the development of an effective and practical antisecretory treatment of ulcer disease in horses.

Safety, acceptability and endoscopic findings in foals and yearling horses treated with a paste formulation of omeprazole for twenty-eight days.

A paste formulation of the H+,K(+)-ATPase inhibitor omeprazole was evaluated in Thoroughbred foals and yearlings for its safety and acceptability. Twenty foals age 11-16 weeks and 20 yearling horses age 15-17 months were included and gastroscopic examinations performed 1-3 days before and at the end of each trial. Lesions were scored on a scale of 0 to 3 and animals allocated based on endoscopic lesion score and sex, with 4 animals in each of 5 replicates. Dosages of 4 mg omeprazole/kg bwt or sham treatment were administered once daily for 28 days, from a syringe graduated in 50 lb (22.68 kg) increments, the amount of paste administered being rounded up to the nearest corresponding weight in pounds. Acceptability of the paste or sham treatment was assessed and recorded by the individual administering the treatment on the basis of the tolerance or resistance to insertion of the syringe into the mouth, administration of the paste and if the paste was swallowed or actively expelled by the animal. Safety was determined on the basis of daily observation recordings and physical examination findings during and at the conclusion of the trial. Treatment was judged to have been accepted for all 420 doses of omeprazole paste and all 140 sham doses given to foals during the trial and for 418/420 doses of paste and all 140 sham doses given to yearlings. Two doses of paste were entirely rejected by yearlings. On the initial endoscopic examination, lesions were observed in the gastric squamous epithelial mucosa in 4 foals and 3 yearlings, and single small, superficial erosions were seen in the gastric glandular mucosa of 2 foals. On the second examination there were small, superficial erosions in the squamous mucosa in 3 foals and 2 yearlings, multi-focal superficial erosions in 1 foal and 1 yearling, and 1 foal had large areas of erosion extending from the margo plicatus toward the dorsal fundus. No lesions in the glandular mucosa were seen in foals or yearlings. There were no significant differences (P < 0.05) in lesion scores between the beginning and the end of the trials in the omeprazole-treated or sham-treated groups of foals or yearlings. A paste formulation of omeprazole, administered at a dose of 4 mg/kg bwt once daily for 28 days, was determined to be highly acceptable to the foals and yearlings we studied, and no adverse effects attributable to the medication were noted.

Acceptability of a paste formulation and efficacy of high dose omeprazole in healing gastric ulcers in horses maintained in race training.

Gastric ulceration has been found to occur in 80-90% of Thoroughbreds in active race training. Previously, variable success has been reported using mucosal surface protectants and H2 receptor antagonist. Omeprazole, a substituted benzimidazole, has been shown to inhibit gastric acid secretion in both man and animals. Fourteen horses, in active race training and with endoscopic evidence of moderated to severe gastric ulceration were divided into 2 groups: Group 1 (7 horses) were given placebo paste orally once daily for 28 days; Group 2 (7 horses) received 1.54 g active omeprazole in the placebo once daily for 28 days. Logs detailing administration and acceptability of the paste, and the horse's feeding and training regime were maintained by the trainer of each horse. Endoscopic examination of the stomach occurred at the beginning of the trial, and at 13-17 days and 27-31 days following commencement of the trial. Those horses that were free of ulceration on Days 27-31 were reexamined on Days 35-49. Acceptability of the paste, whether with or without active omeprazole, was deemed excellent in all horses except on one occasion, when one horse swallowed the paste following initial mild reluctance. Of the horses given the placebo (Group 1), 3 were withdrawn after the 13-17 day endoscopic examination: 1 horse to be given a H2 receptor antagonist, 1 horse was removed from training due to aryepiglottic entrapment and 1 horse had a greater than 10% fall in bodyweight from the start of the trial. Of the horses given active omeprazole (Group 2), one horses was relocated to another race track following the 13-17 day endoscopic examination. For the horses given placebo (Group 1), there was no change in the severity of ulceration. In contrast, the severity of ulceration in the horses given active omeprazole was significantly reduced at 13-17 days and 27-31 days. In 2 Group 2 horses, ulcers that had been completely eliminated subsequently returned when reexamined at 35-49 days. The results of this study suggest that omeprazole, employing a once daily dosing schedule, is effective at reducing the severity or eliminating gastric ulcers in Thoroughbreds in active race training.

Effects of omeprazole paste on healing of spontaneous gastric ulcers in horses and foals: a field trial.

A multicentre, blinded, randomised complete-block, field trial was conducted with 140 horses and foals age 4 weeks-28 years to determine if omeprazole paste is effective and safe in promoting healing of spontaneous gastric ulcers under a variety of field conditions and in different breeds and ages of horses. Horses in the study had gastric ulceration as determined by gastroscopy and were divided into replicates of 4 or 5 animals. One horse in each replicate was assigned randomly to receive an empty omeprazole syringe (sham-dosed control) and the remaining horses received omeprazole paste once daily for 28 days. Gastroscopy was repeated at the end of the study. Horses treated with omeprazole had significantly (P < 0.01) more improvement in ulcer scores at the end of the study compared with controls. Ulcers were improved in 32.4 and 99.0% of the control and omeprazole groups, respectively. Ulcers were completely healed in 8.9 and 86.7% of the control and omeprazole groups, respectively. Under typical field conditions, omeprazole was effective at enhancing healing of spontaneous gastric ulcers in horses of a variety of ages and breeds.

Efficacy of omeprazole paste in the treatment and prevention of gastric ulcers in horses.

Equine gastric ulcer syndrome (EGUS) is very common among performance horses, with a reported prevalence of approximately 90% in racehorses, and also > 50% in foals. Omeprazole, an acid pump inhibitor 5 times more potent than ranitidine, has been used with great success to treat EGUS. This multicentre study of Thoroughbred racehorses with endoscopically verified gastric ulcers was designed to demonstrate the efficacy of an equine oral paste formulation of omeprazole in the treatment and prevention of recurrence of EGUS. Of the 100 horses entered into the study, 25 were sham-dosed for the full 58 days of the study. The remaining 75 horses all received omeprazole paste, 4 mg/kg bwt/day once daily for 28 days. At Day 28, 25 of treated horses continued on this dosing regimen while 25 received a half dose (2 mg/kg bwt once daily) and 25 horses were sham-dosed. By Day 28, gastric ulcers were completely healed in 77% of omeprazole-treated horses, while 92% were significantly (P < 0.01) improved. In contrast, 96% of the sham-dosed horses still had gastric ulcers at Day 28. The improvement was maintained in horses that continued on either a full dose or half dose of omeprazole paste until Day 58. However, in those horses that were removed from omeprazole treatment at Day 28, the incidence and severity of the gastric ulcers at the end of the study were similar to those horses that did not receive the omeprazole paste. This study demonstrates that omeprazole paste, 4 mg/kg bwt per os, once daily, is highly effective in healing gastric ulcers in Thoroughbred racehorses and that either a full dose or half dose of omeprazole paste effectively prevents the recurrence of EGUS. The study also indicates that gastric ulcers in untreated horses did not demonstrate a significant rate of spontaneous healing.

Efficacy of eprinomectin against Hypoderma spp in cattle.

OBJECTIVE: To determine the efficacy of a topical formulation of eprinomectin against natural infestations of first (L1)-stage, and second and third (L2/L3)-stage larvae of Hypoderma spp. ANIMALS: 140 approximately 6- to 18-month-old cattle of various breeds. PROCEDURE: Cattle, selected from herds with high prevalence of Hypoderma infestation, were treated in 4 experiments: within each replicate, 1 animal received eprinomectin at a dosage of 500 micrograms/kg of body weight against first-stage larvae (L1). The second animal received the same treatment against second or third-stage larvae (L2/L3). The third animal served as an untreated control. In a fifth experiment, visible warbles were treated on half of the cattle. Remaining cattle served as vehicle-treated controls. In 1 experiment, warbles were examined from time of treatment until all lesions were resolved. In 4 experiments, emerging Hypoderma larvae were recovered, speciated, and enumerated, and viability was determined. RESULTS: Eprinomectin (500 micrograms/kg) efficacy was complete against L1. Hypoderma L2/L3 eradication approached 100% efficacy (1 live larva was recorded). Warbles in treated cattle resolved in a significantly shorter time than did those in controls. Adverse reactions related to treatment were not observed in any of the trials. CONCLUSIONS: Eprinomectin (500 micrograms/kg) applied topically was safe and highly efficacious for treatment of all larval stages of Hypoderma spp in these trials. CLINICAL RELEVANCE: Attributes of eprinomectin besides antiparasite efficacy allow treatment of all classes of cattle with no need for meat or milk withdrawal.

Nematocidal efficacy of eprinomectin, delivered topically, in naturally infected cattle.

OBJECTIVE: To assess the nematocidal efficacy of eprinomectin in naturally infected cattle. ANIMALS: 62 (31 eprinomectin-treated and 31 control) beef mixed-breed or Holstein cattle, either 6 to 11 or 48 to 96 months old. PROCEDURE: Cattle were housed 21 to 27 days before treatment to allow parasites to reach maturity. Animals were grouped by sex, ranked by weight, and randomly assigned to treatment group. Fecal flotation was done to identify cattle with intestinal nematode infections. Treatment groups were: 1--eprinomectin topical vehicle (1 ml/10 kg) and 2--eprinomectin topical solution (1 ml/10 kg). Cattle were euthanatized by replicate on day 14 or 15, and standard procedures were used to recover of pulmonary, abomasal, small intestinal, and large intestinal nematodes. RESULTS: Eprinomectin efficacy across all trials was 100% against adult Trichostrongylus axei, Haemonchus placei, Oesophagostomum radiatum, and Dictyocaulus viviparus, as well a fourth-stage larval Oes radiatum, Ostertagia ostertagi, Nematodirus helvetianus, and Cooperia spp. Efficacy against adult O ostertagi, Cooperia oncophora, C punctata, C surnabada, C spatulata, N helvetianus, Trichuris sp, and Trichuris fourth-stage larvae was 99.9 and 99.8, 99.6, 98.9, 98.3, 99.7, 97.8, and 84.3%, respectively. All results were significant (P < 0.01) except those for C spatulata. Adverse reactions were not observed. CONCLUSION AND CLINICAL RELEVANCE: Eprinomectin is a safe and effective nematocide against naturally acquired nematode infections in cattle when administered at a dosage of 500 micrograms/kg. Milk and meat withholding is not necessary when using this product.

Eprinomectin: a novel avermectin for control of lice in all classes of cattle.

Eight trials were conducted in the United States to determine the efficacy of eprinomectin applied topically against four common species of lice in cattle. In two dose titration trials, eprinomectin dosages of 125 to 750 mcg/kg body weight applied topically were compared to untreated controls. In dose confirmation studies, animals treated topically with eprinomectin applied at the rate of 500 mcg/kg were compared to vehicle-treated controls. Four species of lice were present in these trials: Linognathus vituli, Haematopinus eurysternus, Solenopotes capillatus, all sucking lice, and Damalinia (Bovicola) bovis, the cattle biting louse. Louse counts were made on six to nine predilection sites (the same number of sites in all animals in the same trial) prior to treatment. The same sites were counted again seven days after treatment and weekly thereafter until trial termination eight weeks after treatment. When no lice were found in the predilection sites, a modified whole body search was conducted. Each species of lice was present on at least six animals in each treatment group on at least one counting date in two or more trials. No lice were found on any animal treated topically with eprinomectin at a dosage of > or = 500 mcg/kg after 14 days posttreatment until termination of the trials eight weeks after treatment.

The efficacy of ivermectin (pour-on) against the eyeworms, Thelazia gulosa and Thelazia skrjabini in naturally infected cattle.

Sixteen crossbred beef cattle, 6-8 months of age, were used to determine the efficacy of ivermectin in a pour-on formulation against natural infections of Thelazia spp. Cattle were weighed on Day 0, ranked in descending order by bodyweight and sequentially paired. Within each pair, one animal was randomly assigned to an untreated control group, while the other animal was treated with a pour-on formulation of ivermectin applied topically at 1.0 ml per 10 kg bodyweight to achieve a dosage of 500 mg ivermectin kg-1 body weight. On Day 14 all animals in both treatment groups were slaughtered. The eyes and surrounding tissues were removed and examined for eyeworms. A total of 86 adult worms (74 Thelazia skrjabini and 12 Thelazia gulosa) were recovered from the untreated control animals. T. skrjabini was found in seven, and T. gulosa in three, of the eight untreated control animals. Two T. skrjabini, one from each of two animals, were found on the surface of the eyes of cattle that had received ivermectin treatment. The reduction in the geometric mean number for T. gulosa collected from treated animals was 100% (P > 0.1) relative to controls, and 97.02% (P = 0.0025) for T. skrjabini relative to controls.

[Resorbable implant materials in retinal detachment surgery. Initial animal experiment studies]. / Resorbierbare Plombenmaterialien in der Amotiochirurgie. Erste tierexperimentelle Untersuchungen.

In detachment surgery after a mechanically stabile chorioretinal scar is at present full scleral indentation no longer mandatory. Following these considerations absorbable scleral implants have been developed and tested in an animal model. Cylindrical pieces of absorbable composite-material with a diameter of 5 mm were sutured as radial scleral explants in 18 rabbits. The composite material consisted of a polyglactin-polydioxanon ratio 7:1. The absorption time for polyglactin is 60 days, for polydioxanon 180 days. The explants produced initially in ultrasonographically measured buckle height between 3.2 and 4.0 mm. The clinical and ultrasonographical follow up study demonstrated a continuous decrease of buckle height. Two weeks after implantation there was a medium height of 2.0 mm after five weeks a medium elevation of 0.5 mm was found. Histopathological examinations showed incidence of a slight resorptive inflammation in the area of the buckle which was not evident after 12 weeks. No scleral infiltration or scleral thinning was found. The promising results have justified controlled clinical trials with the absorbable material which might allow to combine the advantages of silicone sponge explants (precise localization) with those of scleral buckles by inflatible balloons (reversibility).

[Reducing tension in sutures of peripheral nerves]. / Spannungsentlastung bei Nähten peripherer Nerven.

A method is presented to reinforce normal suturing techniques in median and ulnar nerve repairs at the level of the forearm or wrist. If the distance between the stumps does not exceed 20 to 30 mm the coaptation can be protected from tension by two ribbons of polydioxanone (PDS) which are sutured to the epineurium bridging the site of the suture of the nerve. PDS ribbons proved to give remarkable support to experimental nerve repairs using epineural, perineural or Tsuge suture techniques. In further experiments with tibial nerves of rats the PDS ribbon did not interfere with the nerve function or with axon sprouting. Follow-up investigations of thirty-two median and ulnar nerve injuries treated with primary or secondary interfascicular sutures using PDS ribbons of 20 mm length and 1 mm width to protect the suture line revealed satisfactory reinnervation. The late results with this method were superior to a comparable group treated with autografts.

Efficacy of ivermectin in a topical formulation against induced gastrointestinal and pulmonary nematode infections, and naturally acquired grubs and lice in cattle.

Efficacy of ivermectin in a topical formulation was evaluated in cattle against adult gastrointestinal and pulmonary nematode infections (experiment 1, n = 24), the 2nd- and 3rd-stage larvae of Hypoderma spp (experiment 2, n = 12), and the biting louse Damalinia bovis (experiment 3, n = 12). Nematode infections were induced and grubs and lice were naturally acquired. Treatments consisted of a single dose of ivermectin in a topical formulation of 200, 500, or 1,000 micrograms/kg of body weight in experiment 1 or 500 micrograms/kg in experiments 2 and 3. At 1,000 micrograms/kg, ivermectin was 100% effective against Ostertagia ostertagi, Trichostrongylus colubriformis, Oesophagostomum radiatum, Nematodirus helvetianus, Haemonchus placei, and Dictyocaulus viviparus and was greater than 99% effective against Cooperia oncophora, C punctata, and T axei. At 500 micrograms/kg, the efficacy was 100% against C oncophora, C punctata, O ostertagi, T axei, Oes radiatum, N helvetianus, Haem placei, and Dict viviparus and greater than 99% against T colubriformis. At 200 micrograms/kg, the efficacy was 100% against Oes radiatum, Haem placei, and Dict viviparus, greater than 99% for O ostertagi, 96% for C oncophora, 86% for C punctata, 90% for T axei, 85% for T colubriformis, and 71% for N helvetianus. At 500 micrograms/kg, ivermectin was highly effective against the grubs Hypoderma bovis and H lineatum and eliminated the louse Damalinia bovis.

[Refixation of osteochondral fragments using absorbable plastic pins]. / Refixation osteochondraler Fragmente durch resorbierbare Kunststoffstifte.

The authors report on the fixation of cartilage-bone fragments via an (absorbable) PDS rod. The study was conducted with 18 rabbit knee joints. Good healing of the fragments was seen over a period of 10 weeks. In vitro examinations of the rod showed satisfactory tearing and bending strength with only slow deterioration of strength due to hydrolysis. On the basis of these studies the authors believe that the rods are suitable for fixing small fragments in accident surgery. Other fields of application are possible and require to be investigated.