Photomicrographic evaluation of stallion spermatozoal motility characteristics

A photomicrographic method for evaluation of stallion spermatozoal motility was developed, and spermatozoal image and velocity characteristics were defined. The photomicrographic method was compared with visual estimation of motility in the same semen sample over time. Using photomicrography, velocities and percentages of individual spermatozoal image characteristics were determined. Although there was a high correlation between results of the 2 methods, results of the photomicrographic method were more repeatable than were those of the visual method.     

犬精液低温保存稀释液的研究

试验对苏联红犬精液的低温保存稀释液进行了研究。结果表明,犬精液低温保存的稀释液以Tris-葡萄糖稀释液(Tris3.04%,柠檬酸1.7%,葡萄糖1.25%,卵黄20%)为最佳,在4℃保存3 d后,犬精液的精子活率仍可达0.662 5±0.058 2,精子活率>0.1的存活达5.750 0 d±0.462 9 d。在Tris-葡萄糖稀释液中加入0.5%的甘氨酸或1%的牛血清白蛋白并不能明显提高犬精子的低温保存效果,反而添加BSA后,精子活率在0.1以上的存活时间出现明显缩短(P<0.01)。     

Effects of orvus ES paste on canine spermatozoal longevity after freezing and thawing

Because of weak resistance of canine sperm to freezing, an applicable method of preparing canine frozen semen has not yet been established. We added various concentrations of Orvus ES Paste (OEP) to egg yolk Tris-fructose citrate, and investigated its effectiveness on survival of spermatozoa. Addition of 0.5-1.0% OEP to the extender for freezing canine semen was effective in prolonging post-thaw survival of spermatozoa.     

Use of a computerized system for evaluation of equine spermatozoal motility

Three ejaculates from each of 3 stallions were used to evaluate a computerized system (Hamilton-Thorn motility analyzer; HTMA) for measuring equine spermatozoal motility. Variance components (ejaculate-within-stallion, chamber-within-ejaculate, and microscopic field-within-chamber) were determined for each stallion after diluting ejaculates to 25 x 10(6) spermatozoa/ml with a skim milk-glucose seminal extender. The HTMA was compared with frame-by-frame playback videomicrography (VIDEO) for determining: percentage of spermatozoal motility and spermatozoal number in microscopic fields; curvilinear velocity and straight-line velocity of individual spermatozoa for 5 track types; and repeatability of those velocity measurements. The effect of spermatozoal number per microscopic field on incidence of intersecting spermatozoa and the outcome of intersecting spermatozoa also were evaluated. Greatest variability in motility measures was generally attributed to the microscopic field-within-chamber component. The HTMA was highly correlated with VIDEO for estimation of spermatozoal numbers per microscopic field (r = 0.99; P less than 0.001) and motility (r = 0.97; P less than 0.001); however over the entire range of spermatozoal numbers, the HTMA yielded higher spermatozoal numbers per microscopic field (P less than 0.05) and higher motility (P less than 0.05) than did VIDEO. The HTMA- and VIDEO-derived measurements of curvilinear and straight-line velocities were highly correlated for all spermatozoal track types, but both measures were higher (P less than 0.05) by use of the HTMA than by use of VIDEO for most track types. For 3 of 5 track types, measurements of curvilinear and straight-line velocities were less variable (P less than 0.05), using the HTMA, rather than VIDEO.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of canine cumulus oophorus on homologous sperm motility

Sperm ejaculated by 8 beagle dogs and the cumuli oophori collected from 3 estrous beagle bitches were co-incubated, and penetration of the sperm into cumuli was observed to investigate the influence of cumuli on homologous sperm.The percentages of hyperactivated sperm and acrosome-reacted sperm were calculated after incubation with homogenized cumuli. The hyaluronic acid content of the incubated cumuli was measured, and hyperactivation and the acrosome reaction of the sperm were evaluated in medium containing hyaluronic acid. The mean percentage of hyperactivated sperm (33.0%) and number (3.0) of sperm that had penetrated a cumulus among sperm incubated for 7 hr were significantly higher than the values for sperm incubated for 0.5 hr (P<0.01). Almost all sperm that had penetrated the cumuli had intact acrosome, as though they were hyperactivated. The percentages of motile sperm (77.3%) and hyperactivated sperm (23.6%) after 2 hr incubation in the medium containing homogenized cumuli were significantly higher than in control medium (P<0.01), but there was no difference between cumulus and control media in the percentages of acrosome-reacted sperm. The hyaluronic acid content of a cumulus increased after 24 hr incubation. After 2 and 4 hr of incubation the percentages of hyperactivated sperm in the medium containing hyaluronic acid were significantly higher than in the control medium (P<0.01). These results suggest that canine hyperactivated sperm with intact acrosome can penetrate homologous cumuli and that the sperm are able to pass through the cumulus because the hyperactivated movement is maintained by hyaluronic acid secreted by the cumulus cells.     

Evaluation of canine gastric motility with ultrasonography

For the evaluation of canine gastric motility with ultrasonography, contraction number of pyloric antrum and gastric emptying time (GET) by area and volume method developed by Bolondi et al.'s method were studied in 14 dogs. All experimental dogs were administered with saline and soup solution (10 ml/kg, B.W.). The mean values of contraction number of pyloric antrum in saline and soup group were 4.19 +/- 1.30/min and 4.82 +/- 0.65/min before feeding, and overall mean values were 4.66 +/- 1.37/min and 5.13 +/- 1.71/min, respectively. The mean values of the GET by area and volume method were 36.73 +/- 11.27, 40.00 +/- 8.87 min in saline group and 61.35 +/- 17.58, 59.11 +/- 14.46 min in soup group. In the GET in saline and soup groups, there was no significant difference between the area and volume method (p>0.05). Therefore, Bolondi et al.'s method by ultrasound can be used to evaluate the antropyloric motility and gastric emptying time with area and volume methods. The area method is easier to determine the GET than the volume method, but the latter is more accurate.     

Radiographic examination of the canine spine

Radiography plays an essential part in the diagnosis of spinal disease in the dog. Careful positioning of the patient and attention to technique are important in obtaining diagnostic films and sedation or general anaesthesia is usually required, especially if the animal is in pain or muscle spasm. Additional information may be obtained by myelography, a technique in which a water-soluble iodine-containing contrast medium is injected into the subarachnoid space via the cisterna magna, under general anaesthesia. The advent of two new contrast media, iopamidol and iohexol, has rendered this a relatively safe procedure which may be carried out in practice. The radiological features of a variety of canine spinal conditions are discussed, including congenital and developmental abnormalities, infective, nutritional and degenerative conditions and trauma and neoplasia.     

Histologic examination of selected areas of canine pulmonary arteries

Selected areas of pulmonary arteries from 18 healthy mixed-breed dogs were examined using histologic staining techniques. Smooth muscle cell, collagen, and elastin content of the tunica intima and tunica media were assessed. Fifteen dogs had abnormalities of tunica intima or tunica media in at least one arterial section examined. Of all arterial sections examined, 40% had histologic changes of the tunica intima or tunica media, and 42% of these vascular lesions were in the main pulmonary artery. The most commonly occurring pathologic change was loss of smooth muscle cells and elastin of the tunica media and replacement by collagen. This lesion is similar to cystic medionecrosis of the aorta. Seemingly, a high frequency of spontaneous vascular lesions exist in pulmonary arteries of young dogs.     

Real-time ultrasonographic evaluation of canine gastric motility in the postprandial state

Gastric motility is affected by several pathological conditions which may induce upper gastrointestinal clinical symptoms. The pathogenesis of canine gastric motility disorders is poorly understood because of methodological limitations. This study aimed at establishing a simple method for evaluating postprandial gastric motility in dogs. Gastric motility was ultrasonographically assessed in 7 healthy beagles using a technique previously described in humans. The motility index (MI), an indicator of gastric antral motility, was calculated by measuring the area of the gastric antrum in both a contracted and relaxed phase and by counting the number of contractions. The MI was measured every 30 min for 3 hr after feeding and compared with gastric emptying as assessed by a (13)C-octanoic acid breath test. The MI at 30 min had the lowest variability in the 7 dogs (mean SD, 9.77 ± 0.42; coefficient of variance, 4.25%), and a significant correlation was observed with gastric emptying coefficient (R(2)=0.8126, P=0.005) and half-emptying time (R(2)=0.654, P=0.027). When atropine was administered, a significant decrease in the MI at 30 min was observed compared with the control (9.77 ± 0.42 vs. 5.19 ± 0.22, P=0.0003). In conclusion, evaluation of the MI at 30 min is suitable for assessing gastric motility and enables us to assess gastric motility simply in a short time. By using this method, further studies for the pathogenesis of canine gastric motility disorders are warranted.     

Prokinetic effect of the 5-HT4R agonist mosapride on canine gastric motility

We assessed prokinetic action of gastroprokinetic agent, mosapride in dogs. Open-label cross-over study. Six healthy beagles were administered single oral mosapride at doses of 0.5, 0.75, 1, and 2 mg/kg 30 min prior to feeding, followed by 1-week interval. The motility index (MI) of gastric contraction was ultrasonographically evaluated by change rate of antral area and contraction number. Significant increases in MI were observed at doses of 0.75 mg/kg (mean ± SEM, 11.11 ± 0.19), 1 mg/kg (11.65 ± 0.34), and 2 mg/kg (12.04 ± 0.34), compared with that of the control (9.37 ± 0.51). Mosapride administration (2.0 mg/kg, BID) for 1 week had no adverse effects on blood tests or health of the animals. In conclusion, 0.75 to 2 mg/kg of mosapride produces gastric prokinetic actions without adverse effects.     

Technique for physiological examination of canine skeletal muscle in vivo

A technique is described for studying the physiological function of canine skeletal muscle in vivo. The contractile properties of the tarsal flexor muscles were examined in three beagle dogs under general anaesthesia. The force responses to electrical stimulation of the common peroneal nerve were measured at various frequencies to determine the frequency:force relationship for this muscle group. Fatigue characteristics were also examined during intermittent stimulated activity delivered in a set pattern of frequencies. The results provide quantitative characterisation of muscle function which is repeatable. The technique described could be applied to other animals and is a potentially powerful tool for evaluating the effects of drugs on muscle performance.     

Effect of canine immune macrophages and canine immune serum on the growth of Ehrlichia canis

The effect of canine immune macrophages and canine immune serum (CIS) on the growth of Ehrlichia canis was studied in vitro. Treatment of E canis organisms with CIS before they were inoculated into immune macrophage cultures, coupled with pre- and postinoculation maintenance of cultures in CIS, suppressed macrophage infection rates to 1% or less. Immune macrophages collected from E canis-carrier dogs and maintained in canine normal serum were more resistant to the intracellular growth of E canis than were normal macrophages maintained in the same serum. Ehrlichiae introduced into normal macrophage cultures maintained in canine normal serum multiplied within the macrophages and destroyed them. Maximal immunity to intracellular growth of E canis, maximal destruction of this organism, or both, required the interaction of E canis with both humoral and cellular factors in proper sequence.     

Pentoxifylline induces capacitation and acrosome reaction and improves quality of motility in canine ejaculated spermatozoa

To evaluate effects of different concentrations of pentoxifylline, as phosphodiesterase inhibitor, on quality of motility, capacitation and acrosome reaction, Ejaculated spermatozoa were collected from crossbred dogs. The sperm were incubated at concentrations of 0.1, 1, 10 and 100 mM pentoxifylline for 2 h. Conventional assessment was also made on the percentage of motility and quality of motility of spermatozoa; values were expressed as sperm motility index (SMI). Capacitation and acrosome reaction were also evaluated by chlortetracycline fluorescence staining. SMI as quality index of sperm was significantly increased in concentrations of 10 and 100 mM pentoxifylline during 1 and 2 h compared to control. The number of capacitated or acrosome reacted spermatozoa significantly (P < 0.05) were higher than controls at high concentrations of pentoxifylline (10 and 100 mM) during 1 and 2 h. In conclusion, high concentration of pentoxifylline is able to induce capacitation and acrosome reaction and improves quality of motility in canine ejaculated spermatozoa.