Kinetics of individual limbs during level and slope walking with a unilateral transtibial bone-anchored prosthesis in the cat

Ongoing animal preclinical studies on transcutaneous bone-anchored prostheses have aimed to improve biomechanics of prosthetic locomotion in people with limb loss. It is much less common to translate successful developments in human biomechanics and prosthetic research to veterinary medicine to treat animals with limb loss. Current standard of care in veterinary medicine is amputation of the whole limb if a distal segment cannot be salvaged. Bone-anchored transcutaneous prostheses, developed for people with limb loss, could be beneficial for veterinary practice. The aim of this study was to examined if and how cats utilize the limb with a bone-anchored passive transtibial prosthesis during level and slope walking. Four cats were implanted with a porous titanium implant into the right distal tibia. Ground reaction forces and full-body kinematics were recorded during level and slope (±50%) walking before and 4–6 months after implantation and prosthesis attachment. The duty factor of the prosthetic limb exceeded zero in all cats and slope conditions (p < 0.05) and was in the range of 45.0–60.6%. Thus, cats utilized the prosthetic leg for locomotion instead of walking on three legs. Ground reaction forces, power and work of the prosthetic limb were reduced compared to intact locomotion, whereas those of the contralateral hind- and forelimbs increased (p < 0.05). This asymmetry was likely caused by insufficient energy generation for propulsion by the prosthetic leg, as no signs of pain or discomfort were observed in the animals. We concluded that cats could utilize a unilateral bone-anchored transtibial prosthesis for quadrupedal level and slope locomotion.     

Progesterone-dependent cathepsin L proteolytic activity in cat uterine flushings

Sequence analysis of a cDNA clone for the progesterone-dependent protein (PDP) of the cat uterus revealed that PDP may be cathepsin L. This study was undertaken to directly measure the cathepsin L activity in uterine flushings from pregnant and ovariectomized steroid-treated animals in order to confirm that PDP is cathepsin L. Optimum activity toward the substrate Z-Phe-Arg-NMec was observed at a pH of 5-6. Z-Phe-Phe-CHN2, a specific inhibitor of cathepsin L, significantly inhibited the proteolytic activity present in uterine flushings. Immunoabsorption of PDP from uterine flushings obtained from progesterone (P)-treated cats reduced cathepsin L proteolytic activity to levels observed in ovariectomized and estradiol (E2)-treated animals. In E2-primed and E2 + P-treated animals, proteolytic activity in uterine flushings was detectable after 7 days and peaked after 11-13 days of E2 + P treatment. This proteolytic activity was also dramatically increased before implantation (10-12 days after coitus) in pregnant cats. Thus, our data indicate that changes in cathepsin L activity in uterine flushings are correlated with changes in PDP, the uterine protein synthesized and released from the epithelial cells of the deep uterine glands. PDP, via its cathepsin L proteolytic activity, may play a role in the implantation process.     

Changes in endometrial and placental protein synthesis and morphology during pregnancy and pseudopregnancy in the cat

This study was undertaken to determine the effect of the implanting cat blastocyst on endometrial morphology and protein synthesis. Placental and endometrial tissues were obtained from pregnant and pseudopregnant cats and then cultured with L-[35S]methionine and analyzed for protein synthesis by 2-dimensional polyacrylamide gel electrophoresis followed by fluorography, and also processed for light microscopy. The progesterone-dependent protein (PDP), described previously by Boomsma and Verhage (Biol Reprod 1987; 37:117-126) and Verhage et al. (Biol Reprod 1989; 41:347-354), was identified by immunocytochemical and immunoblot analysis. Attachment began after 12 days, and the deep glands contained large deposits of PDP. By 20 days the placenta was well developed, and the deep endometrial glands under the placenta had regressed and lacked deposits of PDP. The placenta continued to develop and thicken as pregnancy progressed. The surface epithelium in the non-implantation site regions developed extreme convolutions, while the well-developed deep glands with large deposits of PDP began to regress by 4 weeks, becoming similar to those in the implantation site. The endometrial glands in the pseudopregnant animals maintained deposits of PDP even though apoptotic bodies were observed between 20 and 35 days. PDP synthesis was not detected in the implantation site after 16 days, but it continued in the nonimplantation site through 5 weeks. The synthesis of nine other proteins was significantly altered by the end of implantation such that the pattern in the non-site endometrium was different from the implantation site but similar to the pattern found in the pseudopregnant endometrium. As pregnancy progressed, protein synthesis was altered in the placental/junctional zone and the non-site endometrium, but in the deep endometrial portion of the implantation site it was largely unchanged and similar to the deep portion of the non-site. Thus, the implanting cat blastocyst has a significant effect on the morphology of the implantation site and non-site endometrium, and alters the protein synthetic activity of the implantation site endometrium but apparently not the non-site region. The morphology and protein synthetic patterns of the pregnant cat uterus show regional differentiation and continue to change as pregnancy progresses.     

Behavioral and Electrophysiological Responses Evoked by Chronic Infrared Neural Stimulation of the Cochlea

Infrared neural stimulation (INS) has been proposed as a novel method for neural stimulation. In order for INS to translate to clinical use, which would involve the use of implanted devices over years or decades, the efficacy and safety of chronic INS needs to be determined. We examined a population of cats that were chronically implanted with an optical fiber to stimulate the cochlea with infrared radiation, the first known chronic application of INS. Through behavioral responses, the cats demonstrate that stimulation occurs and a perceptual event results. Long-term stimulation did not result in a change in the electrophysiological responses, either optically-evoked or acoustically-evoked. Spiral ganglion neuron counts and post implantation tissue growth, which was localized at the optical fiber, were similar in chronically stimulated and sham implanted cochleae. Results from chronic INS experiments in the cat cochlea support future work toward INS-based neuroprostheses for humans.     

Oestrogen production by blastocyst and early embryonic tissue of various species

Oestrogen synthesis by the early embryo in vitro was studied with tissue from pigs, sheep, cows, roe deer, ferrets, cats, rabbits and a plains viscacha. Definitive evidence for aromatase activity and oestrogen synthesis in preimplantation trophoblast was obtained for the pig with the formation of oestrone, oestradiol-17 beta and oestradiol-17 alpha from 3H-labelled androstenedione and dehydroepiandrosterone. Aromatase activity was appreciably lower in all other species studied, and labelled oestrogens were recovered only from incubations of allantochorionic tissue of roe deer, recovered shortly after implantation, and from pooled samples of early embryonic tissue of cows. High aromatase activity in preimplantation trophoblast of pigs was associated with the maternal recognition of pregnancy and the occurrence of superficial implantation in this species.     

Distribution of Feline Blood Types Detected in the Copenhagen Area of Denmark

The purpose of the present study was to make the first survey of the distribution of feline AB blood types in the Copenhagen area of Denmark. A total of 244 cats (139 purebred cats and 105 Domestic Shorthair cats) were tested. 93% of all tested cats had blood type A. Neither an AB nor an O type cat was detected and thus, the frequency of blood type B among all tested cats was 7%. Most type B cats were purebred cats (Birman, British Shorthair and Persian cats). No association between sex and blood type could be demonstrated among British Shorthair and Persian cats. Thus, the present study indicates that cats in Denmark predominantly have blood type A, and that blood type B cats are rare, except for certain breeds such as Birman and British Shorthair cats.     

Chronic polyelectromyography in awake, unrestrained animals.

A procedure is described for making an implantable electrode array for recording EMG activity in muscles of awake, unrestrained animals (rats and cats) at rest, during rhythmic activity and in response to various reflexogenic stimuli. The electrode array consists of a percutaneous connector (covered with Dow-Corning Silastic Medical Adhesive), steel wire spiral leads contained in silicone tubing and silicone plate probes with platinum electrodes. These plate probes can be fixed either to the bone underneath the muscle, slipped under the fascia, or fixed between muscles. EMG records are presented of postural activity and ambulation in rats, mastication in cats and unilateral and bilateral spinal and supraspinal reflex responses in rat hind limb muscles up to 6 months after implantation. The advantages (and drawbacks) of this technique and its possible uses in neurophysiology are enumerated in the discussion.     

The Distribution of Several Elements in Cat Urine and the Relation Between the Content of Elements and Urolithiasis

The concentrations of elements in urine obtained from cats with urolithiasis were compared with those of healthy cats. The concentration of several elements, such as sodium (Na), phosphorus (P), sulfur (S), and potassium (K), in urine obtained from cats with urolithiasis was significantly higher than that of healthy cats. A significant correlation (p<0.01) was found between the concentration of magnesium (Mg) and that of other elements, such as P (r=0.8913), S (r=0.6817), and K (r=0.8391), in the urine obtained from healthy cats. A significant correlation (r=0.7422, p<0.05) was also obtained between the concentration of K and that of P in urine collected from cats with urolithiasis, but the slope of regression line was significantly different from that of the urine obtained from healthy cats. Other correlations observed in healthy cats were not obtained from cats with urolithiasis. However, a significant correlation between the concentration of magnesium (Mg) and that of calcium was obtained only from cats with urolithiasis. The results of the present study suggest that urinary concentrations of various elements in cats with urolithiasis are higher than those of healthy cats. Furthermore, the balance of elements in the urine of cats with urolithiasis was altered.     

猫视神经年龄相关的形态学变化

对4只青年猫(1-3龄)和4只老年猫(10-13龄)视神经进行形态计量比较研究。取两个年龄组的颅内相应部分视神经进行横向连续切片,H.E染色于光镜下观察其基本结构;相邻切片进行结晶紫染色显示胶质细胞;神经丝蛋白(NF)免疫染色显示视神经纤维,胶质纤维酸性蛋白(GFAP)免疫染色显示星形胶质细胞(AS),对实验结果进行统计学分析并绘制纤维直径谱。与青年猫相比,老年猫视神经外膜厚度、直径、面积均显著增加,视神经纤维的密度和数量显著下降,且以视神经中央部纤维密度下降最显著;纤维直径谱分析结果显示,青、老年猫纤维直径分布范围相似,但老年猫的峰直径及纤维平均直径比青年猫的显著减小;另外,老年猫视神经束中的星形胶质细胞明显膨大,胶质细胞密度以及星形胶质细胞占胶质细胞总数的百分比均显著增加。结果表明:在衰老过程中视神经纤维出现明显的丢失现象,纤维平均直径显著减小使其对视觉信息的传导速度减慢,这可能是导致老年个体视觉分析速度下降的重要原因;老年个体视神经束内胶质细胞活动增强可能对维持视神经纤维形态、功能或延缓视神经进一步衰老起保护作用     

Observations on the development of Echinococcus multilocularis in cats

The development of a European isolate of Echinococcus multilocularis was compared in cats and dogs at the end of the prepatent period. Echinococcus multilocularis established in all dogs and cats, but worm recovery was significantly greater from dogs than from cats. Overall, worms in cats were not as advanced as those in dogs in terms of development and maturation, but there was no evidence of retarded development or stunted forms. These results confirm that dogs are highly susceptible to E. multilocularis, whereas cats have lower and more variable recovery rates. However, because cats produce thick-shelled eggs of E. multilocularis after experimental and natural infections, they have to be regarded as potential sources of infection both for intermediate and accidental hosts, including humans. However, their general role in the epidemiology of the infection has yet to be determined.     

The size of cells providing interhemispheric and intrahemispheric connections in the visual cortex of binocular vision-impaired cats

The size (somatic area) of 658 cells located in layers 2/3 of cortical areas 17, 18 of both hemispheres in intact monocularly deprived and bilateral strabismic cats was measured. These cells were retrogradely labelled after injections of horseradish peroxidase into ocular dominance columns in areas 17, 18. In all groups of cats, the mean somatic area of callosal cells was significantly larger than the mean somatic area of intrahemispheric cells. It was found that the mean somatic area of callosal cells was increased by 26.6% in monocularly deprived cats and by 20.2% in strabismic cats in relation to the mean somatic area of callosal cells in intact cats. In addition, the mean somatic area of intrahemispheric cells in monocularly deprived cats was indistinguishable from the mean somatic area of intrahemispheric cells in strabismic cats and in intact cats. It is concluded that early binocular vision impairments produce enlargement of callosal cells' size in the visual cortex.     

Investigating Some of the Factors that Affect the Selection of Shelter Cats by Adopters in the Czech Republic

Records on cat adoptions were collected from three cat shelters situated in different regions of the Czech Republic. Originally, 2,170 cats were admitted to the monitored shelters; of which 1,407 (65%) cats were adopted in the period from 2011 to 2015. Significantly (p < 0.001) greater numbers of cats were adopted in autumn and winter than in spring and summer. The differences in the numbers of adopted cats of different sex, age, or coat color corresponded with the differences in proportions of these characteristics in cats admitted to the monitored shelters. No effect of sex on time to adoption was found. However, age and coat color affected the length of stay (LOS). Geriatric cats had the greatest and adult cats the shortest LOS. Kittens, juveniles, and young adults did not differ in LOS but they all stayed in shelters longer (p < 0.05) than adult cats. The median length of the stay of dark-colored cats was significantly greater (p < 0.001) than that of cats with a light or medium shade of coat color. Significantly (p < 0.001) more cats were adopted by women (748; 76.2%) than by men (233; 23.8%). Understanding seasonal fluctuations in cat adoptions and potential adopter? preferences is crucial for shelter personnel to establish effective procedures for rehoming shelter cats. Considering the relatively long time to adoption (median LOS = 69 days, mean LOS = 139 days, range = 0–1,600 days) more efforts should be put into seeking strategies for reducing this.     

Detection of a progesterone-dependent secretory protein synthesized by cat endometrium

Uterine flushings and culture media from endometrial explants incubated in the presence of radiolabeled amino acids were analyzed using one-(1-D) and two-dimensional (2-D) gel electrophoresis to identify proteins synthesized by the endometrium and subsequently released into the uterine lumen. 1-D and 2-D analyses of uterine flushings and culture media of endometrial explants obtained from 7- to 11-day pregnant cats (pre-implantation) showed a Mr 30,000 protein that appeared on 2-D gels as a family of macromolecules with isoelectric points between 6.5 and 7.0. This family of macromolecules was also present in the culture media of implantation-site tissue obtained from 12- to 16-day pregnant cats and of nonimplantation-site endometrium obtained form 12- to 28-day pregnant cats. The Mr 30,000 protein was absent in uterine flushings and culture media from estrous and 3- to 5-day-pregnant cats. In ovariectomized, steroid-treated animals, the Mr 30,000 protein was only detected in flushings and media from those animals treated with progesterone, regardless of the presence or absence of estradiol-priming and/or simultaneous estradiol treatment. In daily flushings obtained from ovariectomized, steroid-treated cats equipped with an indwelling uterine catheter, the Mr 30,000 protein was absent during the 14 days of estradiol treatment and was first detected 3-4 days after the onset of estradiol plus progesterone treatment. This protein was not detected in serum from estrous, 9-day pregnant, ovariectomized, and ovariectomized, steroid-treated animals. This study shows that 1) a progesterone-dependent protein, with an approximate molecular weight of 30,000 and an isoelectric point of 6.5-7.0, first appears within the uterine lumen soon after the arrival of the blastocyst and continues to be present during implantation; 2) the synthesis and release of the Mr 30,000 protein is dependent on progesterone regardless of the presence or absence of estradiol; and 3) the onset of secretion of the Mr 30,000 protein requires 3-4 days of continuous progesterone treatment in the estradiol-primed cat.     

Roles of the auxiliary genes and AP-1 binding site in the long terminal repeat of feline immunodeficiency virus in the early stage of infection in cats.

To examine the roles of auxiliary genes and the AP-1 binding site in the long terminal repeat of feline immunodeficiency virus (FIV) in vivo, three mutant viruses, which are defective in the vif gene ([delta]vif), ORF-A gene (deltaORF-A), and AP-1 binding site (deltaAP-1), and wild-type virus as a positive control were separately inoculated into three specific-pathogen-free cats. These cats were assessed by measuring the number of proviral DNA copies in peripheral blood mononuclear cells (PBMCs), the CD4/CD8 ratio and antibody responses to FIV for 16 weeks and then examining histological changes at necropsy. Although viral DNAs were detected in PBMCs from all 12 cats to various degrees until 16 weeks postinoculation, no virus was recovered from PBMCs of cats infected with (delta)vif virus during the observation period. However, a very weak antibody response was induced in one cat infected with the (delta)vif virus. In contrast, despite the successful recovery of virus from both groups of cats infected with deltaORF-A and deltaAP-1 virus, antibody responses and decrease in the CD4/CD8 ratio in the groups were milder than those in cats infected with wild-type virus. Furthermore, the numbers of proviral DNA copies in PBMCs from the two groups were not able to reach the level in cats infected with wild-type virus during the observation period. From these results, we conclude that these mutant viruses are still infectious for cats but failed in efficient viral replication and suggest that these auxiliary genes and enhancer element are important or essential to full viral replication kinetics and presumably to full pathogenicity during the early stage of infection in vivo.     

猫小脑皮质GABA能神经元年龄相关性变化

为探讨青年猫和老年猫小脑皮质GABA能神经元及其表达的年龄相关性变化,利用Nissl染色显示小脑皮质结构及神经元,免疫组织化学ABC法标记GABA免疫阳性神经元。光镜下观察,采集图像,并利用图像分析软件对分子层、蒲肯野细胞层和颗粒层神经元及GABA免疫阳性神经元及其灰度值进行分析统计。结果显示,GABA免疫阳性神经元、阳性纤维及终末在青年猫和老年猫小脑皮质各层均有分布。与青年猫相比,老年猫分子层、蒲肯野细胞层神经元和GABA免疫阳性神经元密度及其GABA免疫阳性反应强度均显著下降(P<0.01),颗粒层神经元密度和GABA免疫阳性强度也显著下降(P<0.01),但其GABA免疫阳性神经元密度无显著变化(P>0.05);蒲肯野细胞的胞体萎缩,阳性树突分枝减少。因此认为,衰老过程中猫小脑皮质GABA能神经元的丢失和GABA表达的下降,可能是老年个体运动协调、精确调速和运动学习等能力下降的重要原因之一。     

Investigation of anti-Toxoplasma gondii antibodies in cats of the Ankara region of Turkey Using the Sabin-Feldman dye test and an indirect fluorescent antibody test

Blood samples from 99 cats from the Ankara province of Turkey were examined for the presence of anti-Toxoplasma gondii antibody with the use of both the Sabin-Feldman dye test (DT) and an indirect fluorescent antibody test (IFAT). Forty of the 99 sera (40.3%) were positive for antibodies against T. gondii with the DT, whereas the IFAT assay detected antibodies in 34 (34.3%). The study also evaluated 3 factors for their potential association with the presence of T. gondii antibody: age (<1 yr, 1-2 yr, and >2 yr), gender (female vs. male), and outdoor access (stray, owned with outdoor access, or indoor only). The DT detected antibodies in 3 cats under 1 yr of age, 22 cats between 1 and 2 yr, and 15 cats older than 2 yr, whereas the IFAT found 1, 18, and 15 cats positive for antibodies, respectively, in each of these categories. Of 61 female cats, 27 (44.2%) were positive by the DT; and of 38 male cats, 13 (34%) were positive by the DT. For the IFAT, 24 female cats (39.3%) and 10 male cats (26.3%) were positive. The percent seropositivity in indoor cats was 30.8% by the DT and 23.1% by the IFAT. In stray cats, the percent seropositivity was 52.8% by the DT and 41.7% by the IFAT. Antibody presence was significantly associated with age, but not with outdoor access.     

Alterations in the immune system in cats fed diets with excess cystine

As part of an ongoing biochemical study in nutrition we examined blood profiles, serum chemistry, lymphocyte transformation and lymphoid pathology in cats fed a diet containing 5% cystine with and without taurine. Automated blood counts of whole blood samples showed a decrease in red blood cell counts accompanied by a significant decrease in hemoglobin and hematocrit in cats fed 5% cystine in the absence of taurine compared to cats fed 0.05% taurine (control). A significant increase was noted in serum cholesterol in cats fed cystine and cystine/taurine compared to cats fed control diets. There were no significant differences in lymphocyte transformation using leukocytes isolated from the spleen and blood with the mitogens, phytohemagglutinin and pokeweed. However, lymphocyte transformation of both spleen and blood without mitogen from the excess cystine group were significantly higher than leukocytes from the 0.05% taurine group (control). Pathological examination of regional lymph nodes, livers, and spleens showed histological abnormalities in cats fed the excess cystine diet. These results indicate that there are alterations in the immune system of cats fed a diet containing 5% cystine with and without dietary taurine.     

The influence of strabismus and monocular deprivation on the size of callosal cells in cortical areas 17 and 18 of the cat

To reveal the changes in visual cortex structure following impaired early binocular experience, the size (somatic area) of callosal cells in areas 17, 18 ofmonocularly deprived and convergent strabismic cats was measured. Horseradish peroxidase was injected into the single ocular dominance columns of areas 17, 18 and the transition zone 17/18. In both groups of impaired cats the mean size of callosal cells in area 17 was increased in comparison to intact cats. In area 18, the similar difference was found in monocularly deprived cats only. It was shown that the differences in the mean sizes of cells are due to the increase of the number of large cells. In strabismic cats, the portion of large cells (soma > 200 mkm2) in area 17 was 58% and in area 18 was 8%. The relative share of large cells in areas 17 and 18 of monocularly deprived cats was similar (28 and 26 % correspondingly). These data show that early binocular vision impairments may lead to the changes in cytoarchitecture of cortical layers where the interhemispheric connections originate.