Reduced numbers and intense anti-ubiquitin immunostaining of bovine motor neurons affected with spinal muscular atrophy.

Motor neurons in the spinal cord affected with bovine spinal muscular atrophy (SMA) were investigated immunohistochemically using antibodies against bovine ubiquitin. Anti-ubiquitin immunostained many chromatolytic and swollen degenerating motor neurons in the ventral horn of the SMA-affected spinal cord. The most severely swollen cells showed a lightly-stained center and a strongly-stained periphery after immunostaining. However, there were many dark, shrunken neurons in a more advanced stage that showed a completely negative reaction when immunostained. Motor neuron counts differed significantly between SMA-affected and normal animals at the lumbar intumescence and at the fourth lumbar neuromere, but not at the brachial intumescence or the second cervical level.

Effect of cranial sympathectomy on circadian rhythms of cortisol, adrenocorticotropic hormone and melatonin in boars.

Following weaning at 24 +/- 1 d of age, crossbred boars were subjected to removal of the cranial cervical ganglia (GX, n = 8) or sham surgery (SHAM, n = 8). At 213 +/- 1 d of age, a catheter was inserted into a jugular vein or vena cava, and all boars were housed in environmentally controlled rooms at 22 degrees C with an equatorial photoperiod. After 2 wk of exposure to this photic environment, samples of plasma and serum were collected at hourly intervals for 24 h. The plasma was assayed for adrenocorticotropic hormone (ACTH) and the serum was assayed for cortisol and melatonin by RIA. The time-trends for all three hormones were described by regression models, which were tested for heterogeneity of regression between SHAM and GX treatments. The circadian rhythm of cortisol in serum was similar for SHAM and GX treatments. The profiles of ACTH were also similar between the two treatments, but circadian changes in concentrations of ACTH paralleling those of cortisol were not evident in either treatment. Overall, concentrations of ACTH were reduced (P = .06) for GX boars compared to SHAM boars. The time-trends of melatonin in serum differed (P less than .001) for GX and SHAM treatments, with a nocturnal rise in melatonin evident in some SHAM boars but not in GX animals. Four SHAM boars had profiles of melatonin that obviously entrained to the light-dark cycle. None of the boars in GX treatment had elevated concentrations of melatonin in serum during the dark period, relative to concentrations during the light.(ABSTRACT TRUNCATED AT 250 WORDS)

Auditory-evoked responses of dogs with different hearing abilities.

Sixteen dogs were separated into three groups, based on clinical impressions of their abilities to hear and historical information pertaining to their hearing loss: group I (n = 7) had normal hearing, group II (n = 4) had reduced hearing and group III (n = 5) were deaf. Monaural clicks of alternating polarities were used to elicit brainstem auditory-evoked responses. The responses of the normal group and of the reduced hearing group consistently had four major peaks (I, II, III-IV, V) with latencies similar to those previously reported in dogs with normal hearing. No difference (p greater than or equal to 0.05) was found in mean latencies of the four major waveforms when comparing the normal group with the reduced hearing group. Significant reductions in mean amplitudes of waves I (p less than 0.01) and II (p less than 0.025) were found in the reduced hearing group. No recognizable waves could be recorded from the deaf group, indicating a lack of peripheral auditory function.

Characterization of anatomic communications among the antebrachiocarpal, middle carpal, and carpometacarpal joints in cattle, using intra-articular latex, positive-contrast arthrography, and fluoroscopy.

OBJECTIVE: To evaluate the frequency and sites of communication among the antebrachiocarpal, middle carpal, and carpometacarpal joints in cattle. ANIMALS: 137 limbs were obtained from 72 fresh bovine cadavers submitted for necropsy because of problems unrelated to the carpus. PROCEDURE: 1 of the 3 injection sites was randomly assigned to both carpi of each ox, and a mixture of latex and barium sulfate was injected into the joint. Communication between 2 or more joints was determined by the presence of latex and contrast material in a joint adjacent to the injected joint by examination of frozen sections, positive-contrast arthrography, and fluoroscopy. RESULTS: Communication existed among the 3 joints in 18 specimens (13.1%). The middle carpal joint and the carpometacarpal joint always communicated. The antebrachiocarpal joint communicated with the middle carpal joint between the ulnar and intermediate carpal bones. The middle carpal and carpometacarpal joints always communicated between the fourth and fused second and third carpal bones. In a few specimens, additional sites of communication were identified at the palmar aspect of the fourth carpal bone and the fused second and third carpal bones. CONCLUSIONS AND CLINICAL RELEVANCE: Individual anatomic variation of the carpus in cattle should be considered when diagnostic or treatment protocols are established.

Characterization of anatomic communications of the fetlock in cattle, using intra-articular latex injection and positive-contrast arthrography.

OBJECTIVE: To evaluate the frequency and sites of communication between the lateral and medial synovial sacs of the metatarsophalangeal or metacarpophalangeal joints in cattle. ANIMALS: 188 limbs were obtained from 55 fresh bovine cadavers submitted for necropsy because of problems unrelated to the fetlocks. PROCEDURE: In each ox, lateral or medial synovial sacs of each fetlock were randomly assigned. Joints were injected with a mixture of latex and barium sulfate. Communication between 2 joints was determined by presence of latex and contrast material in a joint adjacent to the injected joint by examining frozen sections and use of positive-contrast arthrography. RESULTS: Communication between the 2 synovial sacs existed in 186 of 188 (98.9%) specimens. The communication site between lateral and medial synovial sacs was located at the level of the proximal sesamoid bones, between the distal aspect of the interdigital band of the axial branch of the interosseus muscle and the metacarpal or metatarsal bone. CONCLUSIONS AND CLINICAL RELEVANCE: Although communication between the lateral and medial synovial sacs did not exist in 2 specimens, the fetlock in cattle can be treated as 1 compartment.

Characterization of anatomic communications between the femoropatellar joint and lateral and medial femorotibial joints in cattle, using intra-articular latex, positive contrast arthrography, and fluoroscopy.

OBJECTIVE: To evaluate the frequency of communication between the lateral and medial femorotibial joints and the femoropatellar joint in cattle. DESIGN: 1 of 3 injection sites was randomly assigned to each ox. ANIMALS: 102 limbs were obtained from 55 fresh bovine cadavers presented for necropsy with problems unrelated to the stifle. PROCEDURE: The joints were injected with a mixture of latex and barium sulfate. Communication between 2 or more joints was determined by the presence of latex and contrast material in a joint adjacent to the injected joint by examining frozen sections and positive-contrast arthrography. RESULTS: Communication between the 3 joints was present in 58 (56.9%) limbs. The femoropatellar and the medial femorotibial joints always communicated. Thirteen of 38 (34.2%) specimens injected in the lateral femorotibial joint did not communicate with the 2 other joints. The femoropatellar joint communicated with the lateral and medial femorotibial joints on the distal abaxial aspect of the trochlear ridge. CONCLUSION: Individual anatomic variation of the stifle in cattle should be considered when diagnostic or treatment protocols are established. CLINICAL RELEVANCE: The lateral femorotibial joint should be treated separately because it does not consistently communicate with the femoropatellar or medial femorotibial joint.

Hypertrophic muscular dystrophy in a young dog.

Hypertrophic muscular dystrophy was diagnosed in a 10-month-old male Rat Terrier with hypersalivation, dysphagia, gait abnormalities, and generalized weakness. Serum creatine kinase activity was high, and electromyography revealed myotonic discharges. Histologic examination of a muscle biopsy specimen revealed muscle fiber degeneration, clusters of basophilic regenerating fibers, and endomysial fibrosis. Staining for dystrophin, a sarcolemmal protein, was decreased, compared with that in muscle specimens from clinically normal dogs. Treatment with mexiletene hydrochloride and procainamide hydrochloride resulted in temporary improvement in clinical signs, but the disease became refractory to treatment, and the dog was euthanatized. Clinical and histologic characteristics of this dystrophin deficiency-related muscular dystrophy were similar to those of X-linked muscular dystrophy in dogs, hypertrophic muscular dystrophy in cats, and Duchenne muscular dystrophy in humans.

X-ray optics. 2: A technique for high resolution spectroscopy.

A novel combination of optical elements and properties is combined to achieve high spectral resolution using grazing incidence optics of modest quality. We show through analysis and ray tracing of examples that using radial groove gratings at high blaze angles in the manner of an echelle spectrograph can provide high spectral resolution. We compare this arrangement to the conventional in-plane designs and show the off-plane to be superior in nearly every respect. Cross dispersion can be provided by the energy resolution of a CCD detector. Then, we show how additional resolution can be squeezed from the system by strategic placement of gratings to take advantage of the azimuthal response of a Wolter x-ray optic. With a telescope that has only 30-sec of arc imaging we are able to support resolution lambda/deltalambda of 3000, while a conventional design at the same graze angle supports resolution of only 200.

Ototoxicity in dogs and cats.

Ears are special sense organs whose principal functions are hearing and maintaining equilibrium. Aminoglycoside antibiotics, erythromycin, polymyxin B, and cisplatin can affect either or both of these functions by binding with, injuring, and/or destroying special receptor cells associated with these functions. Severe hearing loss manifests itself as deafness, whereas loss of equilibrium will present as abnormal righting reflexes, nausea, and vomiting. Damage is proportional to levels of these ototoxins in the endolymphatic fluids. Evidence suggests that toxicity may be influenced by endolymphatic calcium concentrations, and levels of cAMP and cGMP are altered in specialized cochlear cells during ototoxicity, suggesting an additional mechanism for ototoxicity. The administration of salicylates and loop diuretics may potentiate the action of ototoxins, especially aminoglycoside antibiotics, probably by increasing the levels of these toxins in the endolymphatic fluid. Although many of these assessments have been made in laboratory animals, applicability may also be expected in small domestic animals, and extreme care should be taken in prescribing potentially ototoxic drugs to small animals. Cochlear damage from ototoxic compounds occurs initially in the cells detecting high-frequency sounds located at the lower basal region. In aging dogs and humans, this sensitivity of receptors in the lower basal region is enhanced. Early auditory damage is detectable by BAER and cochlear microphonic potentials. Vestibular responses can also be detected early as vestibular ocular reflexes and visual-vestibulo-ocular reflexes. Early detection is especially important because early changes can sometimes be reversible. Cavinton (apovincaminic acid) and fosfomycin represent examples of experimental agents being evaluated in laboratory animals for application as potential treatments to limit the ototoxicity associated with various drugs.

A novel method for preparing histology slides without a microtome.

A study was undertaken to determine if it might be possible to prepare tissue sections on slides without the use of paraffin embedding, microtome sectioning, or cryostat sectioning which involve equipment and training not always available to scholars or professionals wishing to examine tissue microscopically. After evaluating many different reagents, cutting instruments and solid supports, we developed a method involving application of super glue to a slide, adhering a section of tissue to it, cutting the tissue with a disposable microtome blade, staining the tissue and removing the superglue with a commercially available product. The sections are similar to those sectioned on a microtome, but do not at this time equal their quality. However, histoarchitecture is preserved and individual cell morphology is usually good. We conclude that this is a viable method for preparing histology sections without the use of a microtome or cryostat, something long thought impossible. We have dubbed the method 'RAMP' (Rapid Adhesive-Mediated Procedure).

Atlanto-occipital fusion in two polled Hereford calves.

Two cases of atlanto-occipital fusion were diagnosed in Polled Hereford calves. The cause, genetic or environmental, of this abnormality could not be determined. Since relatively minor traumatic forces during birth can cause severe injury in the head region, atlanto-occipital fusion should be ruled out in calves dying acutely after assisted parturition.

Optical constants for thin films of Ti, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Ir, Os, Pt, and Au from 24 A to 1216 A.

Reflectance vs incidence angle measurements have been performed from 24 A to 1216 A on electron-beam evaporated samples of Ti, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Os, Ir, Pt, and Au, and using a nonlinear least-squares curve-fitting technique, the optical constants have been determined. Independently measured values of the incident beam polarization, film thicknesses, and film surface roughnesses are incorporated into the derivation of the optical constants. Additionally, Auger electron spectroscopy depth profiling measurements have been performed on each sample to characterize sample composition including oxidation and contamination.

The 825-1110 angstroms EUV spectrum of Venus.

On 15 August 1994 we launched the EUVS sounding rocket payload to observe the 825-1110 angstrom region of Venus's far ultraviolet airglow spectrum. The EUVS telescope/spectrograph obtained good data at five times higher spectral resolution than was previously available in the far ultraviolet. We present these data and compare our results to those obtained by the Galileo UVS and Venera 11/12 UV spectrophotometers. We identify several new spectral emission features, including both singly ionized nitrogen and molecular nitrogen in Venus's spectrum. We also see evidence for electron-impact-induced emission from CO. Finally, the EUVS data indicate that the "Ar" emissions detected in Venus's far ultraviolet spectrum by Venera 11/12 spectrophotometers are in fact not due to argon, thus eliminating the discrepancy between in situ and remote sensing measurements.

Optical constants for thin films of C, diamond, Al, Si, and CVD SIC from 24 A to 1216 A.

A method for deriving optical constants from reflectance vs angle of incidence measurements using a nonlinear least-squares curve-fitting technique based on the chi(2) test of fit is presented and used to derive optical constants for several thin-film materials. The curve-fitting technique incorporates independently measured values for the film surface roughness, film thickness, and incident beam polarization. The technique also provides a direct method for estimating probable errors in the derived optical constants. Data are presented from 24 A to 1216 A for thin-film samples of C, synthetic diamond, Al, Si, and CVD SiC. Auger electron spectroscopy depth profiling measurements were performed on some of the samples to characterize sample composition including oxidation and contamination.