A murine photothrombotic stroke model with an increased fibrin content and improved responses to tPA-lytic treatment

The Rose Bengal (RB) dye-based photothrombotic stroke (PTS) model has many methodological advantages including consistent location and size of infarct, low mortality, and relatively simple surgical procedures. However, the standard PTS has the caveat of poor responses to tissue-type plasminogen activator (tPA)–mediated lytic treatment, likely as a result of the platelet-rich, fibrin-poor content of the blood clots. Here we tested whether the admixture of thrombin (80 U/kg) and RB dye (50 mg/kg) in the proximal middle cerebral artery (MCA)–targeted PTS will modify the clot composition and elevate the responsiveness to tPA-lytic treatment (Alteplase, 10 mg/kg). Indeed, intravital imaging, immunostaining, and immunoblot analyses showed less-compacted platelet aggregates with a higher fibrin content in the modified thrombin (T) plus RB photothrombotic stroke (T+RB-PTS) model compared with the standard RB-PTS-induced clots. Both RB-PTS and T+RB-PTS showed steady recovery of cerebral blood flow (CBF) in the ischemic border from 1 day after infarction, but without recanalization of the proximal MCA branch. Intravital imaging showed high potency of restoring the blood flow by tPA after single vessel-targeted T+RB-PTS. Further, although intravenous tPA failed to restore CBF or attenuate infarction in RB-PTS, it conferred 25% recovery of CBF and 55% reduction of the infarct size in T+RB-PTS (P < .05) if tPA was administered within 2 hours postphotoactivation. These results suggest that T+RB-PTS produces mixed platelet:fibrin clots closer to the clinical thrombus composition and enhanced the sensitivity to tPA-lytic treatment. As such, the modified photothrombosis may be a useful tool to develop more effective thrombolytic therapies of cerebral ischemia.

Lumbar Epidural Contrast Spread Patterns for the Interlaminar Approach: Three-Dimensional Analysis Using Antero-Posterior, Lateral, and Contralateral Oblique Views

Objective To describe and analyze lumbar epidural contrast spread patterns in antero-posterior (AP), lateral, and contralateral oblique (CLO) views. Methods Lumbar epidural contrast spread patterns after interlaminar injection were prospectively collected in AP, lateral, and several CLO views and analyzed for multiple variables; three-dimensional mapping was also performed. Results Epidural contrast patterns were prospectively analyzed in 28 subjects. The median volume of contrast injected was 2 mL; the AP view was more sensitive than the lateral view to detect foraminal uptake (13/28, 46%, 95% confidence interval [CI] = 27–66%, vs 7/28, 25%, 95% CI = 11–45% subjects). CLO view demonstrated the most consistent location for epidural contrast spread, with contrast contacting the ventral laminar margin in 28/28 (100%, 95% CI = 87–100%) patients. The most common location of contrast spread in the lateral view was at the facet joint lucency, with only 8/28 (29%, 95% CI = 13%–49%) subjects showing contrast contacting the spinolaminar junction. Lateral view was more sensitive than the CLO view in ventral epidural contrast spread detection. The extent and distribution of the spread did not bear any relationship to the volume injected or to the needle location in AP view. Conclusions CLO view provides the most consistent landmark for lumbar epidural contrast spread, and lateral view is most suited to confirming ventral epidural spread. The AP view may be the most optimal for determining target access when considering access to the dorsal root ganglia; in an individual patient, the volume injected and needle location in AP view do not reliably predict target access. The volume to be injected and the need to re-access or obtain multisite access must be prospectively determined, based upon observation of the spread.

Quantifying the Center of Elbow Rotation: Implications for Medial Collateral Ligament Reconstruction

Background: Medial collateral ligament (MCL) reconstruction of the elbow mandates precise characterization of where the centerline of elbow rotation projects onto the medial epicondyle (ME). A muscle-splitting approach allows the flexor-pronator muscles to remain attached to the ME and facilitates visualization of the MCL remnant, the sublime tubercle, and the ulnohumeral joint line. Knowledge of where the centerline of rotation intersects the ME relative to the ulnohumeral joint line may assist the surgeon during placement of the proximal drill hole. Methods: Models were created from the computed tomography scans of 29 normal elbows. The centerline of rotation, center of the trochlea, sublime tubercle, and ulnohumeral joint line were identified. Measurements were taken from the ulnohumeral joint line to the center of the trochlea and to the centerline of rotation in the sagittal view and along the course of the MCL. Results: The centerline of rotation intersected the ME in a consistent location. With the elbow flexed 90°, the trochlea center and the centerline of rotation are essentially in line with each other. There are significant differences between the distances from the ulnohumeral joint line to the center of the trochlea and to the centerline of rotation in both the sagittal view and along the course of the MCL. Conclusions: The centerline of rotation is located 14.31 mm (1.70) from the ulnohumeral joint line in the sagittal view and 16.54 mm (2.09) from the ulnohumeral joint line along the course of the MCL.

HIDE THICKNESS OF MARKET-WEIGHT SWINE AS AFFECTED BY LINE AND SEX

Two hundred and eighty purebred boar and gilt carcasses, representing two genetic lines and 143 crossbred boars, barrows, and gilts were measured for hide thickness at three anatomical locations. A breed difference in hide thickness was apparent. Boars had thicker hides than gilts in the purebred carcasses and gilts and barrows in the crossbred carcasses. Gilt carcasses generally had thicker hides than barrow carcasses. Consistent location differences were evident in the purebred carcasses. Key words: Swine, carcasses, hides, skins, thickness, grading

Optimizing Visual Search and Cursor Movement in Pull-Down Menus

A de facto standard is emerging for the design of pull-down menus. A set of menu items is presented to the user, with temporarily unavailable items listed in a lighter, “grayed-out” font. This ensures the consistent location of each item, but requires the user to visually scan over and possibly move the cursor through extra items that cannot be selected. Previous research has shown that both location and number of items affect users' ability to select items in menus. We examined the tradeoff between these factors by evaluating an alternative in which inactive items are deleted instead of grayed out. Deleting inactive items resulted in faster menu item selection than did graying them out.

Genotype-Environment Interaction Effects in Peanut Variety Evaluation1

Data of both early-and late-maturity groups from the Georgia peanut (Arachis hypogaea L.) variety trails under irrigated and non-irrigated management at two locations in 1975 and 1976 were used to estimate the magnitude of the variety x environment interaction of pod yield, %TSMK, %OK, %DK, %TK, %ELK, %Fancy and g/100 seed. Irrigation treatments caused marked responses of varieties and interaction effects for some of these traits. Both first-and second-order interactions varied under different treatments and for different traits. The significant varieties x locations x years interaction in most traits examined indicated that the varieties x years interaction varied with location. The relatively small values for varieties x location and for varieties x years indicate that there were no consistent location or year effects on differential varietal response for most of those traits during this period of testing. However, results indicate that the variety component significantly exceeded the first-and the second-order interactions and suggest that the varietal effect would be consistently present, especially for pod yield and size factors (g/100 seed, %Fancy and %ELK).