A Lateral Approach to the Repair of Propagating Fractures of the Medial Condyle of the Third Metacarpal and Metatarsal Bone in 18 Racehorses

Objectives— To report the technique, observations on fracture configurations and results of treatment by fixation lag screw following the fracture plane determined by an approach to the third metacarpal/metatarsal bone (MC3/MT3) that begins laterally over the metacarpo(metatarso)phalangeal joint and extends dorsally over the diaphysis of the bone.
Study Design— Case series.
Animals— Thoroughbred horses (n=18) with propagating fractures of the medial condyle of MC3/MT3.
Methods— Retrospective analysis of case records of horses with fractures of the medial condyle of MC3/MT3 that propagated sagittaly or in a spiral configuration into the diaphysis, repaired surgically under general anesthesia by screw fixation in lag fashion through a lateral approach with periosteal reflection.
Results— Fractures were readily identified at surgery, enabling screw fixation in lag fashion following the fracture plane. Fracture configurations varied and could be classified as sagittal and spiral fractures with fractures within each group generally following a similar course. All horses recovered relatively uneventfully from general anesthesia and surgery, and all fractures healed well. Thirteen horses returned to training; 5 subsequently raced.
Conclusions— Repair of propagating sagittal and spiral fractures of the medial condyle of MC3/MT3 with diaphyseal involvement, through a lateral approach with periosteal reflection permits stable fixation with minimal complications. In this series there were no catastrophic failures.
Clinical relevance— Fractures of the medial condyle of MC3/MT3 that propagate either sagittaly or in a spiral configuration into the diaphysis can be successfully repaired with screw fixation in lag fashion using a lateral approach with periosteal reflection.     

VALUE OF A SINGLE-SHOT TURBO SPIN-ECHO PULSE SEQUENCE FOR ASSESSING THE ARCHITECTURE OF THE SUBARACHNOID SPACE AND THE CONSTITUTIVE NATURE OF CEREBROSPINAL FLUID

Three case history reports are presented to illustrate the value of the single-shot turbo spin-echo pulse sequence for assessment of the subarachnoid space. The use of the single-shot turbo spin-echo pulse sequence, which is a heavily T2-weighted sequence, allows for a rapid, noninvasive evaluation of the subarachnoid space by using the high signal from cerebrospinal fluid. This sequence can be completed in seconds rather than the several minutes required for a T2-fast spin-echo sequence. Unlike the standard T2-fast spin-echo sequence, a single-shot turbo spin-echo pulse sequence also provides qualitative information about the protein and the cellular content of the cerebrospinal fluid, such as in patients with inflammatory debris or hemorrhage in the cerebrospinal fluid. Although the resolution of the single-shot turbo spin-echo pulse sequence images is relatively poor compared with more conventional sequences, the qualitative information about the subarachnoid space and cerebrospinal fluid and the rapid acquisition time, make it a useful sequence to include in standard protocols of spinal magnetic resonance imaging.     

EFFECTS OF PELVIC POSITIONING AND SIMULATED DORSAL ACETABULAR RIM REMODELING ON THE RADIOGRAPHIC SHAPE OF THE DORSAL ACETABULAR EDGE

A radiographic study was conducted to evaluate the effect of pelvic rotation and of simulated dorsal acetabular rim (DAR) remodeling on the radiographic appearance of the dorsal acetabular edge (DAE). The DAE is the line connecting the cranial and caudal rims of the acetabulum when viewing a pelvic radiograph made with the dog in the ventrodorsal position with the hind limbs extended. In this study, it was hypothesized that the DAE would change with pelvic rotation and simulated DAR damage. Ventrodorsal radiographs of eight canine pelves were made at 0 degrees, 5 degrees, and 10 degrees of left and right pelvic rotation over its longitudinal axis. These radiographs were repeated following removal of 2, 4, and then 6 mm of bone from the right DAR of each pelvis. The ratio of acetabular width to maximum depth of the DAE was calculated. The area between the DAE and a straight line connecting the cranial and caudal acetabular rims was measured digitally. The DAE depth and area changed with pelvic rotation, and with increasing simulated DAR damage. A linear relationship between the obturator foramina width ratio and pelvic rotation allowed estimation of the degree and direction of pelvic rotation. Equations were developed from the data to assist with the estimation of the amount of DAR remodeling on a clinical radiograph.     

COHESION OF SOIL PARTICLES AND THE INTRINSIC RESISTANCE OF SIMPLE SOIL SYSTEMS TO WIND EROSION

In a simple dry soil system in which erosion is taking place by virtue of the impact of saltating sand grains, the intrinsic variables affecting soil resistance can be investigated with the aid of a mathematical model. The soil erodibility depends on the cohesiveness of the soil which is indicated by the tensile strength. This is directly proportional to the packing density of the system, to the co-ordination number of the particles, and to the inter-particle bond strength. Tensile strength is inversely proportional to the cube of the particle diameter. In a cohesive material any decrease in the particle size produces a great increase in the tensile strength and hence the mechanical stability is improved, but because the particles are lighter they are easily eroded once they are disturbed.     

CHANNELLING OF ALLUVIAL DEPRESSION SOILS IN IRAQ AND SUDAN

Distinctive channel patterns in the floors of alluvial clay depressions in Iraq and Sudan as well as in other parts of the arid zone have been described as gilgai in the past though their morphology differs from examples of gilgai as originally described in Australia. The soils on which the channels develop vary considerably and do not always contain large proportions of expanding lattice clay. The formation of the micro-relief may not necessarily involve heaving of the subsoil as in the Australian gilgai. It is formed rather by a process of uneven settling and compaction, the patterns of channelling being controlled by pre-existing surface irregularities. If the formation of the micro-relief does not involve heaving, it is probable that the channels will not reform after reclamation. The term‘tabra channels’ is suggested for the feature.     

转几丁质酶-葡聚糖酶基因水稻稻瘟病抗谱分析

用来源于云南各地属于24个稻瘟病菌（[i]Magnaporthe grisea[/i]）生理小种的33个菌株,对受体品种南29及其4个转几丁质酶 β-1,3-葡聚糖酶串联基因水稻T5代品系进行了温室接种鉴定。结果表明,不能侵染受体品种南29 的13个菌株也不能侵染转基因品系,可侵染受体品种南29 的20个菌株一般不能侵染转基因品系,转基因水稻对稻瘟病菌抗性范围较受体对照扩大,证明转几丁质酶 葡聚糖酶基因水稻对稻瘟病具有一定的广谱抗性;诱发条件下,转基因品系大田叶瘟病情指数为0～1级,穗瘟发病率为0.3%～10.23%,抗性较受体对照大幅度提高,表明这些品系在稻瘟病抗病育种中是有应用潜力的。     

油田冷凝式燃气加热炉节能效果分析

锅炉的热效率在很大程度上取决于排烟热损失的程度。介绍了油田冷凝式燃气加热炉的结构及其应用 ,指出采用冷凝式燃油燃气加热炉可以将排烟温度降至水露点以下 ,既可以减少排烟中不凝气体的显热 ,又可以回收排烟中水蒸气的潜热 ,因此 ,采用冷凝式燃油燃气加热炉能大幅度减小排烟热损失 ,提高锅炉热效率 ,是一种节能、节水、减少污染的理想燃油燃气加热炉     

Spatial variations in feeding and condition of juvenile pink and chum salmon off Vancouver Island, British Columbia

Spatial variations in feeding and condition of juvenile pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon, and their implications for growth, were examined on the Vancouver Island continental shelf in early summer 1992. Juvenile pink salmon off northern Vancouver Island had more material in their stomachs, were in better condition, and had higher potential growth rates (from a bioenergetics model) than pink salmon off southern Vancouver Island. These variations were consistent with spatial differences in zoo-plankton biomass, there being more plankton in the northern region. There was a significant positive relationship between condition of pinks and the amount of material in their stomachs, suggesting a positive feedback on feeding success. Juvenile chum in the north also had more material in their stomachs than chum to the south. However, condition factor was not significantly different between southern and northern regions nor was there a significant relationship between condition factor and the weight of stomach contents for chum on the southern shelf. A bioenergetics model suggests that chum in the south were food limited. Stable carbon isotope data also indicated different feeding histories for some chum in the southern region, which may have been recent migrants onto the continental shelf from near-shore areas, or possibly a nearby hatchery. Estimation of the energy required by juvenile salmon to migrate north in a continental shelf area with low zooplankton biomass and a weak northerly current (inner shelf), compared with an area with higher zooplankton biomass but a strong southerly current (outer shelf), indicated sufficient surplus energy only in the inner shelf, consistent with observations of northward migrations predominantly through this area. Spatial variations in current velocity and zooplankton biomass can affect feeding, condition, and potential growth of juvenile pink and chum salmon off Vancouver Island.     

Photosensitivity in a Kennel of Harrier Hounds

Résumé— Une dermite s'est développé subitement dans un chenil de 30 chiens courants chez 12 d'entre eux. A la fois des males et des femelles étaient atteints et les lésions étaient limitées aux régions non pigmentées, principalement la face, les membres et la région inguinale. Initiallement les lésions étaient un érythème, un ?déme et une exsudation. Des croutes brunes se sont ensuite formées, et chez la plupart des animaux trés atteints, la peau a laissé la place à un escarre brun agglutiné dans les poils. Un pus malodorant était accumulé sous l'escarre. Les chiens moyennement atteints ont guerie sans traitement et les plus atteints ont guerie après exérèse des escarres et antibiothérapie. Aucun des chiens n'est mort et la plupart ont retrouvé une peau normale au bout de 3 mois. Cliniquement et histologiquement, ces lésions étaient compatibles avec une photosensibilisation, mais il a été impossible de retrouver l'agent causal. [Fairley, R. A., MacKenzie, I. S. Photosensitivity in a kennel of harrier hounds (Photosensibilisation dans un chenil de chiens courants). Resumen— Una condición de la piel se desarrolló de repente en 12 de 30 perros harrier. Afectó a machos y hembras y las lesiones se limitaban a areas de piel sin pigmento, principalmente la cara, patas e ingle. Inicialmente, la piel afectada estaba eritematosa, edematosa y húmeda. Entonces se formaban costras marrones y, en los perros más gravemente afectados, la piel se desprendia dejando una costra marrón seca enredada en el pelo. Debajo de la costra se acumulaba un exudado purulento maloliente. Los perros levemente afectados mejoraron sin tratamiento y los más gravemente afectados lo hicieron despues de tratamiento antibiotico y extirpación de la costra y el pus acumulado. Ninguno de los perros murió y la piel de la mayoria de ellos era normal en 3 meses. Clinica e histologicamente, las lesiones eran compatibles con una condición de fotosensibilidad de la piel, pero las investigaciones no lograron encontrar ningún agenté fotodinámico responsable. [Fairley, R. A., Mackenzie, I. S. Photosensitivity in a kennel of harrier hounds (Fotosensibilidad en una perrera de perros harrier). Abstract— A skin condition developed suddenly in 12 out of 30 harrier hounds. Both males and females were affected and lesions were confined to areas of unpigmented skin, mainly on the face, legs and groin. Initially the affected skin was erythematous, edematous and moist. Brown crusts then formed, and in the most severely affected dogs the skin sloughed leaving a dry brown eschar matted in the hair. A foul-smelling purulent exudate accumulated under the eschar. The mildly affected dogs improved without treatment and the most severely affected dogs improved following antibiotic treatment and the removal of the eschar and the accumulated pus. None of the dogs died and the skin of most dogs was normal within 3 months. Clinically and histologically, the lesions were compatible with a photosensitive skin condition, but investigations failed to find any responsible photodynamic agent.