Elastin content is high in the canine cruciate ligament and is associated with degeneration

Cruciate ligaments (CLs) are primary stabilisers of the knee joint and canine cranial cruciate ligament disease (CCLD) and rupture is a common injury. Elastin fibres, composed of an elastin core and fibrillin containing microfibrils, are traditionally considered minor components of the ligament extracellular matrix (ECM). However, their content and distribution in CLs is unknown. The purposes of this study were to determine the elastin content of canine CLs and to ascertain its relationship to other biochemical components and histological architecture.Macroscopically normal CLs were harvested from Greyhounds (n = 11), a breed with a low risk of CCLD. Elastin, collagen and sulfated glycosaminoglycan content were measured and histological scoring systems were developed to quantify ECM changes using a modified Vasseur score (mVS) and oxytalan fibre (bundles of microfibrils) staining. Elastin contents were 9.86 ± 3.97% dry weight in the cranial CL and 10.79 ± 4.37% in the caudal CL, respectively, and did not alter with advancing histological degeneration. All CLs demonstrated mild degenerative changes, with an average mVS score of 11.9 ± 3.3 (maximum 24). Increasing degeneration of the ligament ECM showed a positive correlation (r = 0.690, P < 0.001) with increased oxytalan fibre staining within the ECM.Elastin is an abundant protein in CLs forming a greater proportion of the ligament ECM than previously reported. The appearance of oxytalan fibres in degenerative CL ECM may reflect an adaptive or reparative response to normal or increased loads. This finding is important for future therapeutic or ligament replacement strategies associated with cranial CL injury.     

Computed tomography to identify preoperative guidelines for internal fixation of the distal sesamoid bone in horses: an in vitro study

Objective: To assess the reliability of computed tomography (CT) to identify the direction of implant insertion for cortical screws along the longitudinal axis of intact (nonfractured) distal sesamoid bones. Study Design: In vitro study. Sample Population: Cadaveric paired equine forelimbs (n=16). Methods: Insertion of a cortical screw in lag fashion along the longitudinal axis of intact (nonfractured) distal sesamoid bones was evaluated in 2 groups (3.5 and 4.5 mm) of 8 paired limbs. In each group, the direction of the distal sesamoid bone was determined by CT (Equine XTC 3000 pQCT scanner). Screw placement was verified by specimen dissection. Implant direction was considered satisfactory if the entire screw length was within the distal sesamoid bone and not damaging the articular or flexural surfaces. Results: In our sample and according to our criteria, the proportion of satisfactory direction of screws was 0.63 (5/8) for 4.5 mm implants, and 0.87 (7/8) for 3.5 mm implants. Conclusions: CT is a useful imaging modality to identify anatomic landmarks for insertion of a 3.5 mm cortical screw in the distal sesamoid bone.     

Validation of a client-based clinical metrology instrument for the evaluation of canine elbow osteoarthritis

Objective : To validate a disease‐specific client‐based clinical metrology instrument (questionnaire) for dogs with chronic osteoarthritis of the elbow joint. Materials and Methods : This was a prospective cohort study involving 26 dogs with chronic osteoarthritis of the elbow with 24 associated clients. Validity (face and criterion), reliability and responsiveness of the metrology instrument (named “Liverpool Osteoarthritis in Dogs [elbow]”) were tested in a sequence of studies. Face validity involved use of international peer review. Reliability was assessed using a test‐retest scenario with a two week interval; peak vertical force as measured by a force platform was used as an external standard measure. Responsiveness was tested with a two week, single‐blinded placebo‐controlled intervention using a licensed non‐steroidal anti‐inflammatory drug. Results : The reliability of Liverpool Osteoarthritis in Dogs (elbow) in the test‐retest scenario was good; intraclass correlation coefficient is 0·89, 95 per cent confidence interval 0·75 to 0·95, compared with intraclass correlation coefficient 0·92, 95 per cent confidence interval 0·74 to 0·98, for peak vertical force. Responsiveness testing indicated that the “net” effect size (allowing for placebo effect) for Liverpool Osteoarthritis in Dogs (elbow) was 0·13 compared with (?)0·18 for the force platform. Criterion validity for Liverpool Osteoarthritis in Dogs (elbow) against peak vertical force was poor; Spearman’s rank correlation is ?0·24 (P=0·30). Clinical Significance : Liverpool Osteoarthritis in Dogs (elbow) was considered reliable with satisfactory responsiveness. The poor criterion validity suggests a mismatch between force platform peak vertical force and client perceptions of lameness. This instrument requires further validation in larger studies with alternative client groups and alternative therapeutic interventions, but this initial validation suggests that Liverpool Osteoarthritis in Dogs (elbow) is worthy of continued investigation.     

Expanding the Repertoire of Spongian-16-One Derivatives in Australian Nudibranchs of the Genus Goniobranchus and Evaluation of Their Anatomical Distribution

Extracts of the mantle and viscera of the Indo-Pacific nudibranchs Goniobranchus aureopurpureus and Goniobranchus sp. 1 afforded 11 new diterpenoids (1–11), all of which possess a tetracyclic spongian-16-one scaffold with extensive oxidation at C-6, C-7, C-11, C-12, C-13, and/or C-20. The structures and relative configuration were investigated by NMR experiments, while X-ray crystallography provided the absolute configuration of 1, including a 2′S configuration for the 2-methylbutanoate substituent located at C-7. Dissection of animal tissue revealed that the mantle and viscera tissues differed in their metabolite composition with diterpenes 1–11 present in the mantle tissue of the two nudibranch species.     

The Henry's Law Constant of Trichloroacetic Acid

The Henry's law constant of trichloroacetic acid [K′_H (mol kg^-1 atm^-1) for the equilibrium CCl₃COOH_(g) ? CCl₃COOH_(aq)] has been determined from measured partial pressures over aqueous solutions at 298.15 K and 308.15 K. Its value is given by: ln(K′_H) = (11.21 ± 0.5) – 8.66 × 10³ (l/T_r – l/T) where T (K) is temperature and T_r is equal to 298.15 K, for an aqueous phase dissociation constant (K_a) of 0.55 mol kg^-1 determined from literature osmotic coefficient and electromotive force data. Accuracy is estimated to be 4–30% in the product K′_HK_a. Trichloroacetic acid is highly soluble and will partition strongly into aqueous atmospheric aerosols, and completely into fog and cloud water. Its occurrence and transport in the environment are therefore to be associated primarily with liquid phases.     

甘蓝型油菜DH系主要性状及SSR分子标记分析

对173份甘蓝型油菜DH系材料主要农艺性状、品质性状以及SSR分子标记的分析表明,DH系系内性状表现高度一致。农艺性状中,分枝高度的变异系数最大（26.39%）,株高的变异系数最小（9.42%）;品质性状中,芥酸含量变异系数最大（62.86%）,含油量的变异系数最小（5.10%）。SSR分子标记分析发现,DNA谱带符合1∶1分离规律。