ABSTRACT. Age-associated changes of magnetic resonance imaging (MRI) on the brain were evaluated in 19 beagle dogs aged from 8-month-to 16-year-old. A significant correlation of the volume of lateral ventricle space was observed in the dogs with age advanced, however, no correlation was found between hippocampus size and the aging. The hypo-intensity areas on T2-weighted MRI were detected in globus pallidus and substantia nigra with a significant correlation of both intensity ratios to lateral ventricle with age advanced. These areas were coincided with the accumulation of iron in the slice of the brain with Perls' staining. In addition, hyperintensity area, suggesting perivascular demyelination with fluid-filled space, was also observed in white matter surrounding the lateral ventricle on T2-weighted MRI. These results suggested that age-associated changes of T2-weighted MRI were developed in the dog brain, especially in globus pallidus, substantia nigra, and white matter surrounding lateral ventricle, like as those reported in the human brain KEY WORDS: age-associated change, brain, canine, hypo-and hyper-intensity, MRI.J. Vet. Med. Sci. 67(10): 961-967, 2005 Magnetic resonance imaging (MRI) has been used as a noninvasive and useful diagnostic technique for evaluating age related brain disorders, such as Alzheimer's disease, Parkinson's disease, and dementia, indicating severe atrophy of the brain, hippocampus, amygdala, and temporal lobe, gray matter, and dilatation of ventricle space, and cortical sulci, [9,17,26,28,34]. However, age-associated similar changes of MRI was also observed in the clinically healthy human brain, indicating brain atrophy, dilatation of ventricle space and cortical sulci, hypo-intensity area in globus pallidus and substantia nigra, and hyper-intensity area in white matter [7,16,20,31]. In addition, age-associated pathological changes of the brain, including developments of senile plaque, decrease number of neuronal cell, deposit of lipofuscin, and activation of astrocyte, have also been well documented [8,12,23,38]. Therefore, it is necessary for diagnose of age related degenerative diseases to evaluate age-associated changes in the brain. Various age-associated changes were detected in aged dogs with occasionally abnormal behaviors [4,6,10,27,30], like as those reported in human [13]. Although MRI has been applied in veterinary clinics and experimental medicine, several reports were on clinical cases and few reports on age-associated changes in the dog brain [5,37]. This study deals with ageassociated changes in MRI on the brain, especially lateral ventricle space, hippocampus size, and hypo-and hyperintensity area, in beagle dogs with age advanced. MATERIALS AND METHODS Animals:Clinically healthy 19 beagle dogs (8 male and 11 female), aged from 8-month-to 16-year-old, were used. All the dogs were bred, reared, and kept in Medicinal Safety Research Laboratories, Sankyo Co., Ltd. under the condition of circumstance temperature at 22 ± 2°C. The air extraction was designed to be 10...

Background The potential effects of aerobic and resistance training in patients with severe chronic kidney disease (CKD) are not fully elucidated. This study investigated the effects of a home‐based exercise programme on physical functioning and health‐related quality of life (HRQOL) in patients with Stage 4 CKD, equivalent to estimated glomerular filtration rate of 15–30 mL/min/1.73 m2. Methods Forty‐six patients with Stage 4 CKD (median age, 73 years; 33 men) were randomly assigned to exercise (n = 23) and control (n = 23) groups. Exercise group patients performed aerobic exercise at 40–60% peak heart rate thrice weekly and resistance training at 70% of one‐repetition maximum twice weekly at home for 6 months. Control patients received no specific intervention. Primary outcomes were distance in incremental shuttle walking test and HRQOL assessed using the Kidney Disease Quality of Life—Short Form questionnaire. Secondary outcomes included kidney function assessed with combined urea and creatinine clearance, urinary biomarkers, and anthropometric and biochemical parameters associated with CKD. Results Improvement in incremental shuttle walking test was significantly greater in the exercise group compared with controls (39.4 ± 54.6 vs. −21.3 ± 46.1; P < 0.001). Among Kidney Disease Quality of Life domains, significant mean differences were observed between the exercise group and the control group in work status, quality of social interaction, and kidney disease component summary outcomes (12.76 ± 5.76, P = 0.03; 5.97 ± 2.59, P = 0.03; and 4.81 ± 1.71, P = 0.007, respectively). There were greater reductions in natural log (ln)‐transformed urinary excretion of liver‐type fatty acid‐binding protein, ln serum C‐reactive protein, and acylcarnitine to free carnitine ratio in the exercise group compared with controls, with significant between‐group differences of −0.579 ± 0.217 (P = 0.008), −1.13 ± 0.35 (P = 0.003), and −0. 058 ± 0.024 (P = 0.01), respectively. Conclusions Our 6 month home‐based exercise programme improved aerobic capacity and HRQOL in patients with Stage 4 CKD, with possible beneficial effects on kidney function and CKD‐related parameters.

A novel bio-based thermosetting elastomer was prepared by the lipase-catalyzed polymerization of methyl ricinoleate with subsequent vulcanization. Some mechanical properties of the cured carbon black-filled polyricinoleate compounds were evaluated as a thermosetting elastomer. It was found that the carbon black-filled polyricinoleate compounds were readily cured by sulfur curatives to produce a thermosetting elastomer that formed a rubber-like sheet with a smooth and non-sticky surface. The curing behaviors and mechanical properties were dependent on both the molecular weight of the polyricinoleate and the amount of the sulfur curatives. Cured compounds consisting of polyricinoleate with a molecular weight of 100,800 showed good mechanical properties, such as a hardness of 48 A based on the durometer A measurements, a tensile strength at break of 6.91 MPa and an elongation at break of 350%.

ABSTRACT. Age-associated changes of visual evoked potentials by flash stimulation (flash VEP) were evaluated in 53 beagle dogs aged from 1-to 15-year-old. Among the components of flash VEP consisted of 3 positive (P1, P2 and P3) and 2 negative (N1 and N2) peaks by 150 msec, the latency of P2 and the later peaks (N2 and P3) were significantly delayed with aging. Both amplitudes of the P2-N2 and N2-P3 also showed a significant correlation with aging. The flash VEP is considered to be an available and useful technique to evaluate not only for visual pathway, but also some disturbance of neurological functions, like as those reported in demented human. KEY WORDS: age-associated change, canine, flash VEP.J. Vet. Med. Sci. 68(1): 79-82, 2006 Visual evoked potentials (VEPs) indicated electrophysiological responses from retina to visual cortex is reported to be an useful technique for evaluating optic pathway [8] and also to be a sensitive indicator for dementia in human [4,18,22]. Visser et al. [21] demonstrated that the latency of the flash VEP components was delayed in the patients with dementia, especially Alzheimer's disease. The latency of the positive peak 2 (P2 :mean latency was 100 msec) and the later components were significantly delayed, although the similar results were sometimes detected in aged human. The flash VEP recorded in dogs showed 3 positive (P1, P2 and P3) and 2 negative (N1 and N2) components by 150 msec after the flash stimuli, like as those reported in human [11,17,19]. In addition, various age-associated pathological and/or physiological changes were commonly observed in aged dogs as well as aged human [5,10]. Since there are few diagnostic techniques for dementia in dogs, age-associated changes of the flash VEP were evaluated using various aged beagle dogs.Total 53 beagle dogs (25 male and 28 female) aged from 1-to 15-year-old kept in Medical Safety Research Laboratories, Sankyo Co., Ltd., were used.The flash VEP was recorded using needle electrodes inserted in the midline of the scalp according to the method reported by Strain et al. [18]. Briefly, electrodes of recording, reference, and ground were placed over the midline of the nuchal crest, forehead, and vertex, respectively. Prior to recording, the dogs were instilled the mydriatic drug, including tropicamide and phenylephrine hydrochloride, and subcutaneously given atropine sulfate (0.05 mg/kg) and intramuscularly given xylazine (2-3 mg/kg) for the sedation. Then the dogs were dark-adapted at least 1 hr and the flash VEP were recorded in the dark shielded room. The white flash stimulus was given 1/sec with the intensity of 0.6 joule using a photostimulator (SLS-3100 Photostimulator, Nihon Kohden Co., Tokyo, Japan). The xenon lamp was located about 15 cm in front of the examined eye and another eye was covered with the black cloth. The responses were recorded with signal averager (Neuropack Four Mini, Nihon Kohden Co, Tokyo, Japan). The bandpass filter was set at 1 Hz low and 1,000 Hz high. In this study, consecutive 30 responses wer...

ABSTRACT. Visual evoked potentials by flash stimulation (flash VEP) were analyzed in dogs using a topographic method. The flash VEP consisted of 3 positive (P1, P2 and P3) and 2 negative (N1 and N2) components by 150 msec after the flash stimuli. On the topographic mappings, a negative response area was observed in the frontal region of the scalp in the stimulated site followed by the shifting of the area to the contralateral frontal region and occipital region, during the first 100 msec. The negative response area in the frontal region in the stimulated site, contralateral frontal and temporal region, and occipital region were corresponded to N1, P2, and N2 on the flash VEP, respectively, according to their latencies. In the dogs with experimentally impaired the right lateral geniculate body, the latency of P2 was prolonged, and N2 and P3 were disappeared after the left eye stimulation. On the topographic mapping, only the early negative response area was detected on the stimulated site of the frontal region of the brain. Therefore, it is concluded that P1 and N1, P2, and N2 are referred to the retinal potentials, the potentials from the retina to the brainstem included the lateral geniculate body, and those from the brainstem to the visual cortex, respectively. KEY WORDS: canine, flash stimulus, lateral geniculate body, topographic mapping, visual evoked potential.