Osteochondral Dowel Transplantation for Repair of Focal Defects in the Knee: An Outcome Study Using an Ovine Model

Objective—A model system was developed to objectively assess the quality of articular cartilage after surgical reconstruction of focal defects in the medial femoral condyle using osteochondral dowel grafts.
Study Design—The surgical technique was developed and customized to reproducibly minimize surgical trauma and graft instability in order to improve the survival of the transplanted cartilage and the long-term integrity of the joint surfaces.
Animals or Sample Population—24 adult female Suffolk-Romanoff crossbred sheep.
Methods—Biomechanical creep testing, paravital staining for chondrocyte viability, histological analysis, and gross morphological analysis were performed at 3, 6, and 12 months postoperatively to compare fresh autografted osteochondral dowels with allografts that had been subject to a freezing protocol known to kill chondrocytes. The latter was used to investigate the time course of cartilage degeneration after injury. These two groups were also compared with normal unoperated control tissue.
Results—Biomechanical behavior, chondrocyte survival, and cartilage histology differed significantly between fresh grafts and those that had been frozen.
Conclusions —Indentation testing and paravital staining were able to identify degenerative changes earlier than other methods of assessment. The technique developed here reproducibly and reliably transplanted osteochondral dowel grafts while minimizing the confounding effects of surgical trauma and graft instability.
Clinical Relevance —The technique provides both a promising surgical technique for the repair of focal defects of the medial femoral condyle and a sensitive model for the future study of cryopreservation strategies for articular cartilage.     

环形窄缝中三叶型节流件阻力特性试验与数值研究

本文对环形窄缝中三叶型节流元件的阻力特性进行了试验研究,获得环缝中不同开口角度θ的三叶型节流件的阻力系数。同时,利用ICEM对带有不同开口角度θ的三叶型节流件环形窄缝进行三维立体建模并进行结构化网格划分。选用重整化k-ε湍流模型,利用Fluent软件进行三维流场模拟。结果表明:试验得到三叶型节流件的阻力系数随着开口角度增大而减小,且近似于指数函数变化;试验得到的不同开口角度θ的三叶型节流件阻力系数与数值模拟结果吻合较好,相对误差在8%以内。     

Use of Vaginal Electrical Resistance to Diagnose Oestrus,Dioestrus and Early Pregnancy in Synchronized Tropically Adapted Beef Heifers

The primary objective of this study was to determine whether a single measurement of intravaginal electrical resistance (VER), using the commercially available Ovatec^® probe, can discriminate between dioestrus and oestrus in Bos indicus females, which had been treated to synchronize oestrus. Santa Gertrudis heifers (n = 226) received one of three oestrous synchronization treatments: double PGF_2α 10 days apart, 8‐day controlled internal drug release (CIDR) treatment or CIDR pre‐synchronization + PGF_2α 10 days after CIDR removal. The heifers were inseminated within 12 h following observed oestrus, or, if not observed, at a fixed time approximately 80 h, following the last synchronization treatment. They were palpated per rectum for signs of pregnancy 9 weeks after artificial insemination (AI). Vaginal electrical resistance measurements were taken at the completion of synchronization treatments (presumed dioestrus), immediately prior to AI (oestrus), and then at 3 and 9 weeks post‐AI. Mean VER differed between presumed dioestrus and oestrus (113.7 vs 87.4, p < 0.001). The area under the receiver operating characteristics (ROC) curve was 0.925, indicating that VER was highly discriminatory between dioestrus and oestrus. Vaginal electrical resistance at time of AI was negatively associated with odds of conception when all inseminations were included in the analyses [odds ratio (OR) = 0.97; 95% CI 0.95–1.00; p = 0.018], but not when fixed time AIs were excluded (OR = 1.00; 95% CI 0.97–1.03; p = 0.982). Mean VER readings differed between pregnant and non‐pregnant animals at both 3 weeks (120.5 vs 96.7, p < 0.001) and 9 weeks (124.0 vs 100.3, p < 0.001) post‐AI. However, 3‐ and 9‐week VER measurements were not highly discriminatory between pregnancy and non‐pregnancy (area under ROC curve = 0.791 and 0.736, respectively). Mean VER at time of AI for animals diagnosed in oestrus differed between each of the oestrous synchronization treatments (84.7, 73.6 and 78.9, groups 1–3 respectively, p < 0.001). These findings suggest that measurement of VER may improve accuracy of oestrus diagnoses when selecting cattle for AI following oestrous synchronization programmes involving tropically adapted cattle.     

The Effect of Experimental Cystitis and Iatrogenic Blood Contamination on the Urine Protein/Creatinine Ratio in the Dog

The effect of experimentally induced cystitis and iatrogenic blood contamination on the urine protein/creatinine ratio (U P/C) was evaluated in 17 dogs. Before they were included in the study, all dogs were judged to be healthy on the basis of physical examination, serum concentrations of urea nitrogen and creatinine, complete urinalysis, and a U P/C less than 0.4. A single urine sample was contaminated with increasing quantities of canine fresh whole blood (PCV = 42%; total protein = 6.2 g/dl). When added blood was equal to or greater than 25% of the total urine sample volume, the U P/C exceeded 3.5, a finding consistent with nephrotic range proteinuria. When added blood was 10% of the total urine sample volume, the U P/C was less than 1.8. Eleven Beagles underwent routine laparotomy during which a cystotomy was done. The median U P/Cs on postoperative days 1 and 2 were significantly increased compared with preoperative values (P less than 0.05); no U P/C exceeded 2.0. Renal biopsies performed on postoperative day 3 eliminated renal proteinuria as a source of urine protein. Five dogs had bacterial cystitis experimentally induced. At 72 and 96 hours after bacterial inoculation, the median U P/Cs were significantly increased (P less than 0.05); individual values ranged from 1.5 to 40.8. Renal biopsies performed between 5 and 6 days after inoculation eliminated renal proteinuria as a source of urine protein. Cytologic evaluation of urine sediment in each group did not correlate with the magnitude of the increase in the U P/C. The U P/C significantly increased in each model of lower urinary tract inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)     

利福昔明子宫注入剂稳定性及其对家兔阴道黏膜刺激性研究

为研究利福昔明子宫注入剂的稳定性,从而初步确定其保质期,本试验取3批利福昔明子宫注入剂进行稳定性试验考察,包括影响因素、高温加速及长期稳定性,利用高效液相色谱法测定试验过程中利福昔明含量及有关物质的含量,从而初步确定利福昔明子宫注入剂的保质期。根据相关技术指导原则对家兔进行阴道刺激性试验。稳定性试验结果表明,根据面积归一化法计算有关物质的含量均不超过3%,注入剂的性状、沉降、粒度未发生明显变化,主成分利福昔明的含量变化在拟定标示量90.0%~110.0%范围内,从而确定本品的有效期为2年。家兔阴道刺激性试验结果显示,利福昔明子宫注入剂给药部位（阴道）和生理盐水对照组给药部位都没有出现红斑和水肿,刺激强度的评分为0;试验组和对照组的阴道黏膜没有出现明显的充血、水肿及异常分泌物流出的现象,阴道黏膜刺激指数为0.25。因此,利福昔明子宫注入剂对家兔的阴道无刺激性。本品的临床安全性良好,可进一步推广使用。     

The Cryosurgical Treatment of Pigmentary Keratitis in Dogs An Experimental and Clinical Study

Forty normal dogs were exposed to double freezes of a 1 cm diameter area of their central corneas using a liquid nitrogen spray. Postoperative sequelae and final histopathologic results were evaluated. All eyes suffered epithelial damage and developed corneal edema, but dogs followed for 3 weeks returned to a normal or near normal condition. Nine clinical cases of pigmentary keratitis were subsequently treated by cryosurgery. The complications following this technique were similar to those seen in the experimental dogs. Reduction in corneal pigmentation and improvement of vision occurred in all cases.     

An Investigation of Uterine Nitric Oxide Production in Mares Susceptible and Resistant to Persistent Breeding‐Induced Endometritis and the Effects of Immunomodulation

The first objective of this study was to evaluate intrauterine nitric oxide (NO) and endometrial inducible NO synthase (iNOS) in mares susceptible or resistant to persistent breeding‐induced endometritis (PBIE) within 24 h after breeding. Mares susceptible (n = 6) or resistant (n = 6) to PBIE were inseminated over five cycles, and uterine secretions and endometrial biopsies were collected before and 2, 6, 12 and 24 h after insemination. Uterine secretions were analysed for NO and biopsies were analyzed for iNOS expression. A second experiment evaluated the effect of treatment with dexamethasone or mycobacterial cell wall extract (MCWE) on uterine NO production and endometrial iNOS mRNA expression. Six susceptible mares were inseminated over three cycles with (i) killed spermatozoa without treatment (control), (ii) killed spermatozoa with 50 mg of dexamethasone IV or (iii) MCWE IV 24 h prior to insemination with killed spermatozoa. Six resistant mares were inseminated with killed spermatozoa as a control. Six hours after breeding, uterine biopsies and secretions were collected and evaluated for NO and iNOS mRNA. In Experiment 1, resistant mares had an increase in iNOS mRNA expression 2 h post‐breeding compared to baseline (p = 0.045), 12 h (p = 0.014) and 24 h (p = 0.001). Susceptible mares had higher expression 2 h compared to 6 h (p = 0.046). No differences were observed in mRNA or protein expression of iNOS between resistant and susceptible mares. Resistant mares had a relatively steady amount of total intrauterine NO over 24 h, while susceptible mares had an increase over time, with a significantly higher increase in total NO than resistant mares at 6 (p = 0.04) and 12 h (p = 0.032). In Experiment 2, no differences were observed for iNOS mRNA expression. Susceptible mares had increased NO when compared to resistant mares (p = 0.008) and MCWE decreased NO (p = 0.047).     

猪葡萄球菌感染裸鼠及BALB/c小鼠模型的研究

用一株本室分离鉴定能够引起猪渗出性皮炎的猪葡萄球菌(S.hyicus GZ1)经肌肉注射裸鼠和BALB/C小鼠,意图研究裸鼠和BALB/C小鼠对猪葡萄球菌的易感性及猪葡萄球菌对裸鼠和BALB/C小鼠的致病性。结果表明裸鼠和BALB/C小鼠均可被感染,并表现各自的临床症状。裸鼠在感染后2到3d背部和面部皮肤开始出现大量小的红色囊泡,4到5d后部分囊泡消失,部分形成结痂。一些裸鼠眼睛还会有较多脓性分泌物渗出,感染两周后相继死亡。BALB/C小鼠感染该菌后多表现急性临床症状,感染后2到3d就相继死亡,因此表现不出明显的眼观病变,只有很少一部分小鼠皮肤上会出现炎性渗出,导致该处皮肤脱落。研究表明:BALB/C小鼠比裸鼠对猪葡萄球菌更易感,裸鼠感染后产生清晰可见的临床症状,而BALB/C小鼠在感染后往往还来不及表现明显的临床症状就相继死亡。可见,猪葡萄球菌不仅对猪有致病性,对裸鼠和BALB/C小鼠也都表现出不同程度的致病性。     

Effect of Progesterone Prior to GnRH-PGF2α Treatment on Induction of Oestrus and Pregnancy in Anoestrous Awassi Ewes

An experiment was conducted to examine the effect of progesterone prior to a GnRH‐PGF_2α treatment on oestrus and pregnancy in seasonally anoestrous Awassi ewes. Twenty‐four ewes were randomly assigned to three groups to be pre‐treated with 60 mg medroxyprogesterone acetate sponges (group A), 600 mg progesterone sponges (group B) or blank sponges (group C) for 4 days. All ewes were injected with 100 μg of GnRH 24 h after sponge removal followed, 5 days later, by 20 mg PGF_2α injection. Ewes were exposed to three fertile rams at the time of PGF_2α injection (day 0, 0 h) and were checked for breeding marks at 6‐h intervals for 5 days. Blood samples were collected from all ewes 1 day (day ?10) prior to sponge insertion, at the time of sponge removal (day ?6), 1 day following sponge removal (day ?5, at the time of GnRH injection) and at the time of PGF_2α injection (day 0) for analysis of progesterone. Progesterone concentrations on days ?10 and ?5 were basal and averaged 0.2 ± 0.04 and 0.2 ± 0.2 ng/ml, respectively. Progesterone concentrations on day ?6 were elevated only in group B ewes and were higher (p < 0.0001) than those of groups A and C. Progesterone concentrations on day 0 were higher (p = 0.002) in groups A and B than group C. Oestrous responses occurred only in ewes of groups A and B (p > 0.05). Induced oestrus conception rate was greater (p < 0.01) in group A than groups B and C. Ewes returned to oestrus 17–20 days following day 0 were two of eight, six of eight and three of eight of groups A, B and C, respectively, all of which eventually lambed. The overall lambing rate was 82% in progesterone‐primed ewes compared with only 38% non‐progesterone‐primed ewes (p < 0.05). Progesterone priming apparently sensitizes GnRH‐PGF_2α‐treated seasonally anoestrous ewes and increases their response in oestrus and pregnancy rates.     

Resistance mechanisms and farm-level distribution of fecal Escherichia coli isolates resistant to extended-spectrum cephalosporins in pigs in Spain

Introduction

Fecal Escherichia coli isolates showing a phenotype of reduced susceptibility or resistance to extended-spectrum cephalosporins are common among pigs in Spain. The aim of this study was to describe the main beta-lactam resistance mechanisms carried by these strains and their distribution at farm-level.

Materials and methods

Twenty-nine E. coli isolates showing reduced susceptibility or resistance to extended-spectrum cephalosporins were collected from a sampling frame of 80 pig farms distributed over 13 Spanish provinces. The survey was carried out at the slaughterhouse level in 2004.

Results

Of the 29 isolates, 21 (72%) met the criteria for a positive phenotypic confirmatory test for extended-spectrum beta-lactamases (ESBL). The following ESBLs were detected: SHV-12 (12 isolates, 41%), CTX-M-1 (three isolates, 10%), CTX-M-9 (three isolates, 10%), and CTX-M-14 (three isolates, 10%). The remaining eight isolates (28%) were phenotypically non-ESBL, with seven of them (24%) showing mutations on the chromosomal ampC gene promoter at positions −42 (C → T), −18 (G → A), −1 (C → T), and +58 (C → T). A multiplex PCR for detection of plasmidic class C beta-lactamases was negative for all isolates.

Conclusion

Different ESBLs and other mechanisms linked to extended-spectrum cephalosporin resistance are widely distributed among fecal E. coli from slaughter pigs in Spain.     

Methods and Errors in Measurements of Synovial Fluid Volume in Stifles with Low Volume and High Viscosity Synovial Fluid. An Experimental Study in Goats

Synovial fluid (SF) volume was calculated using various methods in the stifles of goats, in which the cranial cruciate ligament had been transected on one side. Measurements were performed prior to surgery and again 4,8, and 18 weeks following surgery, by measuring the dilution of an injected radioactive tracer diluted by the SF. Later, 7 months following surgery, SF volume measurements using simple arthrocentesis were performed on stifles in 9 of the goats, and the SF that could not be aspirated, was calculated using 2 indirect methods simultaneously on identical fluids in 3 of these goats. SF was also collected directly during staged arthrotomy of the stifles in 4 goats.There were conflicting results between methods, but the resulting calculated SF volumes seemed to be larger in the operated stifles compared to the controls for all the methods at about the same degree. The 2 indirect methods used to calculate the fluid remaining in the joints following arthrocentesis gave disparate volume calculations. The experiments revealed sources of error in all methods. Direct methods failed to acquire the total fluid volume, and indirect methods were subject to improper mixing and escape of the injected fluid or synovial fluid or both. It was concluded that none of the methods could be used to measure the “true” volume of SF, if such a concept exists and can be defined. None of the methods were considered reliable to compare volumes in different type of joints containing this type of fluid. It was, however, concluded that all the methods gave indication of increased SF volume present on a relative basis when paired joints were compared.     

An Experimental Study on the Treatment and Prevention of Shimao Zheng Fleece-Eating) in Sheep and Goats in the Haizi Area of Akesai County in China

A series of experimental trials on methods of treatment and prevention of shimao zheng fleece-eating) were carried out using various sulphates. The results confirmed the hypothesis that this is a local nutritional and metabolic disease, caused mainly by a sulphur deficiency, that could be prevented or cured with supplementary sulphur in the diet. In field studies, the clinical signs virtually disappeared within 14 days of the animals receiving medicated pellets. Over the same period, the concentrations of sulphur in the blood, liver and spleen returned to normal and the pathological changes in the skin improved. The condition of the controls became worse in each of these respects over this time. However, the pathological changes in the musculature were not alleviated by the treatment.     

Axial Pattern Flap Based on the Cutaneous Branch of the Superficial Temporal Artery in Dogs: An Experimental Study and Case Report

OBJECTIVE: To determine the anatomic guidelines and viability of an axial pattern flap based on the cutaneous branch of the superficial temporal artery (STA) in dogs. Application of the flap in a clinical patient is reported. STUDY DESIGN: Flap viability in control and experimental groups was determined 7 days postoperatively. ANIMALS: A total of 14 mature, mesaticephalic dogs; 1 clinical patient. METHODS: The cutaneous branch of the STA and vein were incorporated in the flaps of the experimental groups (group A, n = 5; group B, n = 4) and were ligated in the control group (n = 5). Flap length was extended in experimental group B. Seven days postoperatively, the length and area of tissue that remained viable in each flap was determined and compared with similar measurements performed intraoperatively. Cutaneous fluorescence was also used postoperatively to assess flap perfusion. The flap used in the clinical patient had the same dimensions as flaps developed in group A. RESULTS: Mean survival length (+/- SD) of STA flaps [group A, 9.1 (0.8) cm], was significantly increased (P < .05) compared with control flaps [7.0 (0.6) cm]. Percentage flap length survival (+/- SD) of STA flaps [group A, 91.8 (8.9)%], was significantly increased (P < .05) compared with control flaps [71.6 (7.0)%]. Mean percentage area of survival (+/- SD) of STA flaps [group A, 93.1 (7.5)%], was significantly increased (P < .05) compared with control flaps [73.5 (7.4)%]. Group B flaps had a mean survival length of 10.4 (1.1) cm, percentage flap length survival of 69.5 (4.8)%, and mean percentage area of survival of 69.1 (6.5)%. There was no positive correlation between the area of flap fluorescence at days 0, 1, and 3, and the area of flap survival. Application of the flap in a clinical patient allowed primary wound reconstruction with 100% survival. CONCLUSION: A flap based on the cutaneous branch of the STA may be a source of skin for reconstructive procedures of the maxillofacial region in dogs. CLINICAL RELEVANCE: Knowledge of the anatomic landmarks and expected viability of a STA axial pattern flap is essential before consideration of its use as a reconstructive surgical technique.     

Assessment of Awareness about Antibiotic Resistance and Practices Followed by Veterinarians for Judicious Prescription of Antibiotics: An Exploratory Study in Eastern Haryana Region of India

Tropical Animal Health and Production - The rise of antibiotic resistance and its global outreach has recently become a subject of increasing importance in veterinary research with an objective to...