An Analysis of Extensor Carpi Ulnaris Groove Morphology and Tendon Instability.

BACKGROUND: The extensor carpi ulnaris (ECU) tendon has a distinct subsheath at the distal ulna. Symptomatic tears of this subsheath and subluxation of the ECU tendon often require reconstruction. We sought to determine the anatomical constraints of the ECU subsheath. METHODS: The ECU subsheath was exposed on 12 fresh-frozen upper extremities. The tip of the ulnar styloid, the distal ulnar joint surface, and the proximal extent of the distal radio-ulnar joint were identified and dimensions measured. Subluxation of the tendon was then assessed with and without an intact subsheath in 9 specimens. The travel of the tendon was measured in pronation through supination and flexion before and after sectioning of the subsheath. RESULTS: The ECU subsheath is 8.9 mm (standard deviation [SD] = 0.8 mm) wide proximally and 9.0 mm (SD = 1.2 mm) distally. The distal ulnar insertion is 0.5 mm (SD = 0.8 mm) proximal to the tip of the styloid, and stretches 10.2 mm (SD = 2.7 mm) proximally. From maximum pronation to maximum supination and flexion, the ECU tendon traveled 3.32 mm (SD = 4.24) medially when the subsheath was intact and 5.42 mm (SD = 5.0 mm) after sectioning. The maximum depth of the ulnar groove was 2.5 mm (1.59-3.56 mm). There was no significant association between changes in ECU subluxation and the depth of the ECU groove (Spearman's rho = 0.25). CONCLUSION: The ECU subsheath is roughly 1 cm square stretching proximally from the ulnar styloid. ECU groove depth is not a significant independent predictor of tendon subluxation.

Effects of Maternal Fenbendazole on Litter Size, Survival Rate, and Weaning Weight in C57BL/6J Mice.

Fenbendazole is a broad-spectrum benzimidazole commonly used in laboratory animal medicine as an anthelmintic for elimination of pinworms. This drug is generally regarded as safe, with minimal side effects. Some data in rodent species indicate multiple physiologic effects of fenbendazole, including changes in immune parameters and behavior, but no studies to date have evaluated possible effects on reproduction in mice. The purpose of the current study was to determine the effects of several treatment regimens of fenbendazole on reproductive parameters in C57BL/6J mice. Uninfected mice were given fenbendazole-treated feed continuously or every other week until pups were born or weaned. This treatment also was combined with environmental decontamination. No significant differences in litter size, survival rate, or weaning weight were detected between groups. Under the conditions of this study, fenbendazole treatment does not affect reproduction in C57BL/6J mice.

Contaminated Shipping Materials Identified as the Source of Rotaviral Infection of Exported Mice.

Over a 4-wk period in 2017, we received notification from 7 different institutions that mice exported from our SPF barrier facilities had tested positive for mouse rotavirus (MRV). The exports originated from several different buildings across multiple campuses. Our institution excludes MRV in all of our barrier facilities and has historically been free of this virus. Extensive testing of our rooms from which the exported mice originated did not detect the presence of rotavirus. The single commonality among the 7 shipments was the use of shipping boxes acquired from one vendor. These shipping boxes arrived at our institution prepackaged with unsterilized feed and bedding, which we hypothesized was the source of the rotavirus. To test this hypothesis, we housed naïve sentinel mice in clean cages with feed and bedding transferred from 29 unopened, unused shipping boxes. Sentinel mice were exposed to this bedding and feed for 14 d and then evaluated through MRV serology and PCR assay. Of the 29 sentinels, 24 were seropositive for MRV, and 14 of the 29 were PCR positive. These results provided direct evidence that MRV detected by recipient institutions originated from the contaminated feed or bedding within the shipping boxes. To our knowledge, this report is the first description of contaminated materials in shipping boxes resulting in rotaviral infection of mice during export.

Biomechanical Comparison of Superior Versus Anterior Plate Position for Fixation of Distal Clavicular Fractures: A New Model.

OBJECTIVES: Although most clavicular fractures are amenable to nonoperative management, metadiaphyseal fractures are considerably more complex, with rates of suboptimal healing as high as 75% when treated nonoperatively. The poor results are ascribed to the deforming forces on the distal clavicle from the surrounding muscles and the weight of the arm. It recently has been noted that some operative fixations of these fractures are also failing when a standard superiorly placed plate is used. We hypothesized that anterior plating, when compared with superior plating, improves the strength and durability of the construct by redirecting the axis of the major deforming force across rather than in line with the screws of the construct. METHODS: Six pairs of fresh-frozen human cadaveric clavicles with the scapula attached by the coracoclavicular ligaments were osteotomized just medial to the ligaments and plated with a standard 3.5-mm limited-contact dynamic compression plate. Specimens were potted and mounted on a materials testing system machine, preserving the anatomic relationship of the clavicle and scapula. They were then loaded through the coracoclavicular ligaments to mimic the weight of the arm pulling inferiorly. Each specimen was loaded with 375 N at 1 Hz for 2000 cycles. Sequential loading was then applied at 25-N intervals until failure. Statistical analysis was performed using a Wilcoxon signed-rank test. RESULTS: The superiorly plated specimens failed after fewer cycles and with lower force than the anteriorly plated specimens. The median number of cycles to failure was 2082 for anterior plated specimens and 50 for superiorly plated (P = 0.028). The median load to failure was 587.5 N in the anterior group and 375 N in the superior group (P = 0.035). The median stiffness was 46.13 N/mm for anterior and 40.45 N/mm for superior (P = 0.375) plates. CONCLUSIONS: Anteriorly plated distal third clavicular fractures have superior strength and durability compared with fractures plated superiorly when using a physician-contoured, 3.5-mm, limited-contact, dynamic compression plate in this cadaver model.

Improving the Success of Strategic Management Using Big Data.

Strategic management involves determining organizational goals, implementing a strategic plan, and properly allocating resources. Poor access to pertinent and timely data misidentifies clinical goals, prevents effective resource allocation, and generates waste from inaccurate forecasting. Loss of operational efficiency diminishes the value stream, adversely impacts the quality of patient care, and hampers effective strategic management. We have pioneered an approach using big data to create competitive advantage by identifying trends in clinical practice, accurately anticipating future needs, and strategically allocating resources for maximum impact.

Comparison of intramedullary fixation techniques in the maintenance of functional anatomy of the elbow after fixation of the proximal ulna.

The objective of this study was to compare intramedullary (IM) nail and IM screw fixation for reattachment of the proximal ulna. Preserved elbow anatomy served as the primary outcome and was defined as the distance between the coronoid process and the olecranon. A retrospective cohort study of 31 patients treated with IM fixation of the proximal ulna was performed. Radiographs were used to compare displacement distances between the coronoid process and the olecranon, with average follow-up of approximately 5 months. IM nail fixation corresponded to a mean displacement of -0.65 mm between the olecranon and coronoid process, versus 0.23 mm for IM screw fixation. No patients were identified with loss of reduction of bone fragments. Both IM fixation techniques maintained the functional anatomy of the elbow. Minimal displacement of bone fragments and no identified loss of reduction suggest that both techniques could be reasonable alternatives to more traditional approaches.

Surgical techniques of olecranon fractures.

Olecranon fractures are common upper extremity injuries. The vast majority are treated with operative fixation. Many treatment techniques have been described including tension band and plating. This review covers the most commonly used fixation techniques in detail, including pearls and pitfalls with case examples of both successful treatments and potential complications.

Assessing cervical dislocation as a humane euthanasia method in mice.

Research investigators often choose to euthanize mice by cervical dislocation (CD) when other methods would interfere with the aims of a research project. Others choose CD to assure death in mice treated with injected or inhaled euthanasia agents. CD was first approved for mouse euthanasia in 1972 by the AVMA Panel on Euthanasia, although scientific assessment of its humaneness has been sparse. Here we compared 4 methods of spinal dislocation--3 targeting the cervical area (CD) and one the thoracic region--in regard to time to respiratory arrest in anesthetized mice. Of the 81 mice that underwent CD by 1 of the 3 methods tested, 17 (21%) continued to breathe, and euthanasia was scored as unsuccessful. Postmortem radiography revealed cervical spinal lesions in 5 of the 17 cases of unsuccessful CD euthanasia. In addition, 63 of the 64 successfully euthanized mice had radiographically visible lesions in the high cervical or atlantooccipital region. In addition, 50 of 64 (78%) mice euthanized successfully had radiographically visible thoracic or lumbar lesions or both. Intentionally creating a midthoracic dislocation in anesthetized mice failed to induce respiratory arrest and death in any of the 18 mice subjected to that procedure. We conclude that CD of mice holds the potential for unsuccessful euthanasia, that anesthesia could be valuable for CD skills training and assessment, and that postmortem radiography has minimal promise in quality-control assessments.

Effects of multimodal analgesia on the success of mouse embryo transfer surgery.

Multimodal analgesia is promoted as the best practice pain management for invasive animal research procedures. Universal acceptance and incorporation of multimodal analgesia requires assessing potential effects on study outcome. The focus of this study was to assess effects on embryo survival after multimodal analgesia comprising an opioid and nonsteroidal antiinflammatory drug (NSAID) compared with opioid-only analgesia during embryo transfer procedures in transgenic mouse production. Mice were assigned to receive either carprofen (5 mg/kg) with buprenorphine (0.1 mg/kg; CB) or vehicle with buprenorphine (0.1 mg/kg; VB) in a prospective, double-blinded placebo controlled clinical trial. Data were analyzed in surgical sets of 1 to 3 female mice receiving embryos chimeric for a shared targeted embryonic stem-cell clone and host blastocyst cells. A total of 99 surgical sets were analyzed, comprising 199 Crl:CD1 female mice and their 996 offspring. Neither yield (pups weaned per embryo implanted in the surgical set) nor birth rate (average number of pups weaned per dam in the set) differed significantly between the CB and VB conditions. Multimodal opioid-NSAID analgesia appears to have no significant positive or negative effect on the success of producing novel lines of transgenic mice by blastocyst transfer.

Soiled bedding sentinels for the detection of fur mites in mice.

Identification and eradication of murine fur mite infestations are ongoing challenges faced by many research institutions. Infestations with Myobia musculi and Myocoptes musculinus can lead to animal health problems and may impose unwanted research variables by affecting the immune and physiologic functions of mice. The purpose of this study was to evaluate the utility and efficacy of soiled bedding sentinels in the detection of fur mite infestations in colony mice. Female young-adult CRL:CD1(ICR) mice (n = 140) were exposed over a 12-wk period to various volume percentages of soiled bedding (11%, 20%, 50%, and 100%) from fur-mite-infested animals. Mice were tested every 2 wk with the cellophane tape test to identify the presence of fur mite adults and eggs. At the end of 12 wk, all mice exposed to 11%, 20%, and 50% soiled bedding tested negative for fur mites. One of the 35 mice (3%) receiving 100% soiled bedding tested positive for fur mites at the end of the 12-wk follow-up period. These findings suggest that the use of soiled bedding sentinels for the detection of fur mite infestations in colony mice is unreliable.

Dietary soy protein isolate ameliorates atherosclerotic lesions in apolipoprotein E-deficient mice potentially by inhibiting monocyte chemoattractant protein-1 expression.

Soy-based diets reportedly protect against the development of atherosclerosis; however, the underlying mechanism(s) for this protection remains unknown. In this report, the mechanism(s) contributing to the atheroprotective effects of a soy-based diet was addressed using the apolipoprotein E knockout (apoE-/-) mice fed soy protein isolate (SPI) associated with or without phytochemicals (SPI+ and SPI-, respectively) or casein (CAS). Reduced atherosclerotic lesions were observed in aortic sinus and enface analyses of the descending aorta in SPI+- or SPI(-)-fed apoE-/- mice compared with CAS-fed mice. SPI+-fed mice showed 20% fewer lesions compared with SPI(-)-fed mice. Plasma lipid profiles did not differ among the 3 groups, suggesting alternative mechanism(s) could have contributed to the atheroprotective effect of soy-based diets. Real-time quantitative PCR analyses of proximal aorta showed reduced expression of monocyte chemoattractant protein-1 (MCP-1), a monocyte chemokine, in mice fed both soy-based diets compared with the CAS-fed mice. These findings paralleled the reduced number of macrophages observed in the lesion site in the aorta of SPI+- or SPI(-)-fed mice compared with CAS-fed mice. In an in vitro LPS-induced inflammation model, soy isoflavones (genistein, daidzein, and equol alone or in combination) dose dependently inhibited LPS-induced MCP-1 secretion by macrophages, suggesting a role for soy isoflavones for the protective in vivo effects. Collectively, these findings suggest that the reduction in atherosclerotic lesions observed in mice fed the soy-based diet is mediated in part by inhibition of MCP-1 that could result in reduced monocyte migration, an early event during atherogenesis.

Syncope, massive aspiration, and sudden death following rattlesnake bite.

Fatalities following rattlesnake bite are rare in the United States, usually occur some hours following the bite, and are generally secondary to direct venom effects. We report a patient with acute syncope and subsequent massive aspiration resulting in airway obstruction and rapid death following a probable Northern Pacific rattlesnake (Crotalus oreganus oreganus) bite.

Toward measurement of social exchange resources: reciprocal contributions and receipts.

This study investigates development of measures for the social resources which may be exchanged in working relationships, such as between supervisors and subordinates or between employees and work group peers. Items designed to measure social resource categories were administered to a heterogeneous sample of 260 employees from diverse organizations. This sample was fairly evenly divided by sex, age, job type, and employment tenure. Analysis showed both contribution and receipt of social resources can be distinctly measured for four different categories (information, respect, liking, and effort).

Molecular cloning of an oxytocin-like receptor expressed in the chicken shell gland.

The avian homologs of arginine vasopressin (AVP) and oxytocin (OT) are arginine vasotocin (AVT) and mesotocin (MT), respectively. In birds, AVT shares many of the functions of AVP including regulation of fluid balance, blood pressure regulation and the stress response. AVT also plays an oxytocin-like reproductive role in birds by stimulating uterine (shell gland) contraction during oviposition. The role of MT in avian reproduction is not clear. Here, we report the cloning of a third neuropeptide receptor in the chicken (Gallus gallus). Parsimony analysis reveals that the new receptor has highest homology to mammalian OT receptors and the MT receptors of non-mammalian vertebrates. Moreover, the receptor bears far less homology to the two avian VT receptors that have been cloned. Reverse transcription-polymerase chain reaction and in in situ hybridization analyses reveal the receptor is expressed in both the endometrium and myometrium of the shell gland. The expression pattern and high homology to OT receptors suggest that the receptor may stimulate myometrial contraction and therefore play a critical role in oviposition.