Post-mortem metabolism in fresh porcine, ovine and frozen bovine muscle

After slaughter, beef carcasses (n = 20) in groups of two were subjected to five treatments (one side only) including intermittent spray-chilling using water, 1% acetic acid or 1% lactic acid, or a single spray treatment with 1% acetic acid or 1% lactic acid. Intermittent spray-chilling consisted of two sprays of 30 s duration per hour for 12h. Single spray treatment consisted of one 30 s spray after entering the chill cooler. The other side of each carcass (control) was air chilled (at 2 to 3°C; air velocity 1 to 3 m/s) only. Five subprimal cuts were taken from each side at 48 h post mortem, vacuum packaged and stored for 28 days at 2°C. Intermittent sprays of sides with acetic or lactic acid resulted in significant (1.8-4.3 log/cm(2)) reductions in aerobic plate count of the strip loin, boneless rib and clod over their controls after these subprimal cuts had been vacuum packaged and stored for 28 days at 2°C in high-oxygen barrier (HOB) film. Lactobacillus spp. were dominant in the microflora of the subprimals from the control and treated sides. When sides were treated with a single sprays of acid, significant reductions in APC were noted only for some cuts of sides treated with lactic acid. After 28 days of storage, there were few significant differences in percentage purge, lean color, and off-odor scores between subprimals from control and treated sides.     

Detection of coronary stenoses on source and projection images using three-dimensional MR angiography with retrospective respiratory gating: preliminary experience

OBJECTIVE: Our objective was to study the ability of three-dimensional MR angiography with retrospective respiratory gating to reveal stenoses in proximal coronary arteries on source and projection images. CONCLUSION: Proximal coronary artery stenoses can be identified using three-dimensional MR angiography with retrospective respiratory gating, both with projection images and on source images alone. Reasons for missed lesions included collateral vessels and retrograde flow distal to complete occlusion and volume averaging of vessels with adjacent structures. Causes of false-positive interpretations included small foci of decreased signal intensity distal to complete occlusion, partial volume effects on individual partitions, and regions of distal vessels leaving the imaging plane.     

Diagnostic value of nasal provocation testing and rhinomanometry in allergic rhinitis

Assessment of the hemodynamic and anatomic results following balloon angioplasty of discrete native coarctation of the aorta, with particular attention to "remodeling," has required repeat cardiac catheterization and angiography, which is invasive and has limited resolution. Eight patients with hypertension and discrete native coarctation with an otherwise normally developed aortic arch underwent angioplasty at 5.0 +/- 6.8 years of age. Angiographic cross-sectional areas of the aorta indexed to body surface area at the isthmus (I), coarctation site (C), and 1 cm distal to the coarctation site (Cd) pre- and postangioplasty were compared with MRI-indexed cross-sectional areas 18 +/- 10 months (MRI-1) and 35 +/- 11 months (MRI-2) postangioplasty. From preangioplasty to MRI-2, the isthmus was smaller (149 +/- 22 versus 127 +/- 27 mm2/m2; p < 0. 05). The coarctation site was larger postangioplasty (25 +/- 9 versus 116 +/- 40 mm2/m2; p < 0.001) with continued growth at latest follow-up (116 +/- 40 versus 164 +/- 36 mm2/m2; p < 0.01). The segment 1 cm distal to the coarctation site continued to decrease in area at latest follow-up (267 +/- 78 versus 163 +/- 38 mm2/m2; p < 0. 001). I versus C versus Cd at MRI-2 were similar, whereas postangioplasty and MRI-1 cross-sectional area measurements were significantly different. Following angioplasty of discrete native coarctation, the aorta becomes more uniform or undergoes "remodeling." Noninvasive MRI is an effective means of evaluating the anatomic result following balloon angioplasty, obviating the need for repeated invasive cardiac catheterizations.     

The Conversion of UDP-Glc to UDP-Man: In Silico and Biochemical Exploration To Improve the Catalytic Efficiency of CDP-Tyvelose C2-Epimerases

A promiscuous CDP-tyvelose 2-epimerase (TyvE) from Thermodesulfatator atlanticus (TaTyvE) belonging to the nucleotide sugar active short-chain dehydrogenase/reductase superfamily (NS-SDRs) was recently discovered. TaTyvE performs the slow conversion of NDP-glucose (NDP-Glc) to NDP-mannose (NDP-Man). Here, we present the sequence fingerprints that are indicative of the conversion of UDP-Glc to UDP-Man in TyvE-like enzymes based on the heptagonal box motifs. Our data-mining approach led to the identification of 11 additional TyvE-like enzymes for the conversion of UDP-Glc to UDP-Man. We characterized the top two wild-type candidates, which show a 15- and 20-fold improved catalytic efficiency, respectively, on UDP-Glc compared to TaTyvE. In addition, we present a quadruple variant of one of the identified enzymes with a 70-fold improved catalytic efficiency on UDP-Glc compared to TaTyvE. These findings could help the design of new nucleotide production pathways starting from a cheap sugar substrate like glucose or sucrose.     

Chiral Surface Lattice Resonances

Collective excitation of periodic arrays of metallic nanoparticles by coupling localized surface plasmon resonances to grazing diffraction orders leads to surface lattice resonances with narrow line width. These resonances may find numerous applications in optical sensing and information processing. Here, a new degree of freedom of surface lattice resonances is experimentally investigated by demonstrating handedness-dependent excitation of surface lattice resonances in arrays of chiral plasmonic crescents. The self-assembly of particles used as mask and modified colloidal lithography is applied to produce arrays of planar and 3D gold crescents over large areas. The excitation of surface lattice resonances as a function of the interparticle distance and the degree of order within the arrays is investigated. The chirality of the individual 3D crescents leads to the formation of chiral lattice modes, that is, surface lattice resonances that exhibit optical activity.     

Effect of shigella enterotoxin 1 (ShET1) on rabbit intestine in vitro and in vivo

The purpose of this study was to identify the optimal knot construction for interrupted dermal sutures. A synthetic braided absorbable suture, sizes 3-0 and 5-0, was selected for this evaluation. With reproducible mechanical performance tests, we determined that the construction of secure knots without ears required one additional throw as compared with secure knots with 3-mm ears. The direction of applied tension did not alter knot security, with the exception of granny knots, which required an extra throw when tension was applied parallel to the suture loop. Because interrupted dermal knot construction is accomplished without knot ears and with an applied tension parallel to the wound, one additional throw must be added to the knot to ensure knot security.     

Immunogenicity of a Salmonella typhi CVD 908 candidate vaccine strain expressing the major surface protein gp63 of Leishmania mexicana mexicana

Attenuated Salmonella typhi are attractive for use as live vector vaccines to express protozoal antigens and deliver them to the human immune system. The gene encoding the mature form of Leishmania mexicana mexicana gp63 under control of tac promoter was integrated into the delta aroC locus of the chromosome of attenuated delta aroC, delta aroD S. typhi strain CVD 908. After oral immunization of BALB/c mice with two 1 x 10(9) colony forming unit doses given 21 days apart, CVD 908 omega (delta aroC::Ptac-gp63) elicited a broad T cell-mediated immune response against L. m. mexicana gp63 as demonstrated by: (1) lymphoproliferative response to fixed whole L. m. mexicana promastigotes; (2) activation of IL-2 (but not IL-4)-producing lymphocytes; (3) appearance of cytotoxic T cells against mouse mastocytoma cells expressing gp63. This T-cell mediated immune response was associated with significant protection in F1 (BALB/cXC57Bl/6) mice challenged in their footpads with a wild type strain of L. m. mexicana.     

Prolonged expression of zinc finger immediate-early gene mRNAs and decreased protein synthesis following kainic acid induced seizures

STUDY DESIGN: A high-resolution strain measurement technique was applied to axially loaded parasagittal sections from thoracic spinal segments. OBJECTIVES: To establish a new experimental technique, develop data analysis procedures, characterize intrasample shear strain distributions, and measure intersample variability within a group of morphologically diverse samples. SUMMARY OF BACKGROUND DATA: Compression of intact vertebral bodies yields structural stiffness and strength, but not strain patterns within the trabecular bone. Finite element models yield trabecular strains but require uncertain boundary conditions and material properties. METHODS: Six spinal segments (T8-T10) were sliced in parasagittal sections 6-mm thick. Axial compression was applied in 25-N increments up to sample failure, then the load was removed. Contact radiographs of the samples were made at each loading level. Strain distributions within the central vertebral body were measured from the contact radiographs by an image correlation procedure. RESULTS: Intrasample shear strain probability distributions were log-normal at all load levels. Shear strains were concentrated directly inferior to the superior end-plate and adjacent to the anterior cortex, in regions where fractures are commonly seen clinically. Load removal restored overall sample shape, but measurable residual strains remained. CONCLUSIONS: This experimental model is a suitable means of studying low-energy vertebral fractures. The methods of data interpretation are consistent and reliable, and strain patterns correlate with clinical fracture patterns. Quantification of intersample variability provides guidelines for the design of future experiments, and the strain patterns form a basis for validation of finite element models. The results imply that strain uniformity is an important criterion in assessing risk of vertebral failure.