Activin A: from sometime reproductive factor to genuine cytokine

The growth factor, activin A, was initially characterized as a putative reproductive hormone but is now known to have many other divergent roles. One of these is during inflammation. Following intravenous injection of bacterial lipopolysaccharide (LPS) into sheep, activin A is released extremely rapidly into the circulation. The release of activin A appears to be independent of fever, prostaglandins or other key proinflammatory cytokines such as TNF-alpha or IL-1beta. While the precise roles and function of this factor in inflammation are yet to be elucidated, the activin response occurs in other mammalian species besides the sheep and elevated activin has been documented for a number of clinical inflammatory conditions. Activin A therefore seems to be part of the regulatory component of the innate immune response.     

Canine sacroiliac luxation: anatomic study of dorsoventral articular surface angulation and safe corridor for placement of screws used for lag fixation

OBJECTIVE: To define a safe corridor in the dorsoventral plane to facilitate placement of screws inserted in lag fashion within the sacral body for fixation of sacroiliac fracture-luxation injuries in dogs. STUDY DESIGN: Anatomic study. SAMPLE POPULATION: Cadaveric canine sacra. METHODS: Canine sacra (n=45) were used for a radiographic study to define a safe corridor in the dorsoventral plane for placement of screws inserted in lag fashion for fixation of sacroiliac luxation in the dog. The defined safe corridor allowed drilling to a depth of 65% of the sacral width to ensure screw purchase of > or =60%. Effects of positioning and measurement techniques were evaluated. RESULTS: Eighty-seven safe corridors were measured. The mean articular surface was 100+/-4.52 degrees from horizontal. Mean maximum, optimum, and minimum safe corridor drill angles were 111+/- 4.57 degrees, 100+/-4.70 degrees, and 89+/-5.17 degrees, respectively, from the articular surface. Predicted surgeon error of +/-4 degrees was used to define the safe corridor for use clinically. CONCLUSIONS: In 91% of sacra, a drill angle of 100+/-4 degrees would remain ventral to the vertebral canal. Twelve sacra (14%) were at risk of penetration of the pelvic canal. A drill angle of 97+/-4 degrees avoids penetration of the vertebral canal in all sacra measured but risks ventral exit from the body in 30% of sacra studied. CLINICAL RELEVANCE: A drill angle of 97 degrees from the articular surface is recommended for insertion of screws for lag fixation of canine sacroiliac luxation.     

MAGNETIC RESONANCE IMAGING FEATURES OF CERVICAL SPINAL CORD MENINGIOMAS

The records of four dogs with cervical spinal cord meningiomas were retrospectively reviewed. Signalment, history, laboratory findings, neurological examination, and histopathological findings were evaluated. Magnetic resonance imaging (MRI) was performed using a 1.0-T superconducting magnet and T2-weighted (W) and noncontrast and postcontrast T1-W spin echo pulse sequences. Meningiomas were located at the level of the second, third, and fifth cervical vertebrae and the C2-3 intervertebral space. All meningiomas appeared as focal masses that were hyperintense to the spinal cord on T2-W images and iso- to hypointense on the T1-W images. They could be identified as intradural and extramedullary in origin based on a broad-based dural margin seen on at least one of the imaging planes and a gradual expansion of the subarachnoid space cranial and caudal to the mass, best noted on the transverse and dorsal plane images. On dorsal plane T2-W images in three dogs, expansion of the subarachnoid space adjacent to the mass appeared similar to the myelographic "golf tee" sign. All meningiomas exhibited moderate, well-defined contrast enhancement with dural tails seen in three of the four dogs. One dog had extension into the intervertebral foramen along the nerve and ipsilateral atrophy of the muscles of the neck. By differentiating the meningiomas from intramedullary tumors and by clearly depicting the extent of the masses, MRI provided valuable information about treatment options and prognosis.     

Relative sensitivity of polymerase chain reaction assays used for detection of feline herpesvirus type 1 DNA in clinical samples and commercial vaccines

OBJECTIVE: To determine relative detection rates and detection limits for 6 published polymerase chain reaction (PCR) assays used for detection of feline herpesvirus type 1 (FHV-1) DNA. SAMPLE POPULATION: 5 vaccines licensed for use in preventing FHV-1-associated disease; 15 conjunctival biopsy specimens collected from cats with keratitis, conjunctivitis, or both; and a plaque-purified field isolate of FHV-1 cultured in vitro. PROCEDURE: Vaccines and clinical samples were assessed for FHV-1 DNA by use of all 6 assays. Detection rates were calculated by assuming that any sample in which FHV-1 DNA was detected was a true-positive result. Detection limits were estimated by use of serial dilutions of DNA extracted from cultured FHV-1 and 1 clinical sample. RESULTS: Testing by use of all 6 assays resulted in detection of FHV-1 DNA in all 5 vaccines. Testing by use of all 6 assays yielded concordant results for 9 of 15 conjunctival biopsy specimens (8 with negative results and 1 with a positive result). Calculated detection rates for clinical samples ranged from 29% to 86%. Assay sensitivity was ranked similarly by use of detection rate or detection limit. CONCLUSIONS AND CLINICAL RELEVANCE: Testing by use of all assays was equally likely to detect vaccine virus. Therefore, a positive PCR result in a cat may reflect vaccine virus rather than wild-type virus. Test sensitivity as assessed by detection limits and detection rates varied greatly. Because FHV-1 can be shed in clinically normal animals, high detection rate will not necessarily correlate with high diagnostic sensitivity.     

Light intensity can influence plasma FSH and age at sexual maturity in domestic pullets

1. Shaver White and ISA Brown pullets were reared to 140 d in cage groups of 8 on a 10-h photoperiod of incandescent light and maintained at an illuminance of 3 or 25 lux, or transferred from 3 to 25 lux or from 25 to 3 lux at 63 or 112 d of age. 2. Plasma follicle stimulating hormone (FSH) concentration at 63 and 112 d was higher in both breeds for pullets maintained at an illuminance of 25 lux compared with 3 lux. After 2-4 d, and relative to constant-illuminance controls, plasma FSH increased significantly for ISA Brown transferred from 3 to 25 lux at 63 d and for Shaver White transferred at 112 d. Irrespective of genotype, plasma FSH for pullets given a decrease in illuminance at 63 or 112 d showed a tendency for less change than did constant-illuminance controls. 3. There was no significant difference in sexual maturity for ISA Brown maintained on 3 or 25 lux, but Shaver White pullets exposed to constant 3 lux matured later than those maintained on 25 lux. Shaver White matured later following an increase from 3 to 25 lux at 63 and 112 d, and earlier subsequent to a decrease from 25 to 3 lux at 112 d. ISA Brown pullets were not significantly affected by a change in illuminance at 63 or 112 d, though their responses were in the same direction as Shaver White. 4. Changes in plasma FSH in the 2- to 4-d period following a change in illuminance at 63 or 112 d were not significantly correlated with sexual maturity.     

Determination of biogenic amines in aerobically stored beef using high-performance thin-layer chromatography densitometry

The aim of this study was to develop a high-performance thin-layer chromatography densitometry method to simultaneously evaluate levels of different biogenic amines (BAs) in beef stored aerobically at 4°C. Steaks from M. longissimus thoracis et lumborum muscles were overwrapped with polyvinyl chloride film and stored for 0, 4, 7, and 10 days. For this purpose, the solvent system and pH for the derivatization of BAs with dansyl chloride were optimized. Moreover, this method was also validated for linearity, limits of detection and quantification, precision, and recovery. As found using this method in beef samples, spermine content decreased significantly after 7 days of storage, and tyramine and cadaverine were not detected until day 10.     

Natural causes of death in non-suckling grey seals (Halichoerus grypus)

Thirty-four grey seals which died of natural causes were examined. They ranged in age from aborted fetuses to adults, but suckling pups were excluded from the study. The commonest primary cause of death was pneumonia and a variety of parasitoses occurred as secondary lesions.     

Evaluation of heparin for prophylaxis of equine laminitis: 71 cases (1980-1986)

The records of 71 horses with small intestinal disorders requiring surgical correction were disorders requiring surgical correction were reviewed to compare the prevalence of laminitis in those horses treated prophylactically with heparin and the prevalence of horses not treated with heparin. The prevalence of laminitis was 13% (9/71), and there was no significant difference (P less than 0.05) in the prevalence of laminitis between the 2 groups. The lack of significant benefit after treatment with heparin indicates that further work needs to be done on the equine coagulation system before heparin can be advocated for prevention of laminitis.