Azoospermia of dogs with apoptotic germ cells and Leydig cells

Apoptotic cell death in the testes of 4 dogs with azoospermia was examined. Blood plasma luteinizing hormone (LH), testosterone (T), and estradiol-17beta (E2) concentrations, and testicular transferrin (Tf) concentration as a marker of Sertoli cell function were measured in the 4 azoospermic dogs and in 5 normal dogs. The spermatids in 2 of the 4 azoospermic dogs and the Leydig cells in 3 of them exhibited apoptotic cell death. Mean LH, E2, and Tf concentrations in the 4 azoospermic dogs were significantly higher than in the normal dogs (P<0.01). These findings suggested that the azoospermia in all 4 dogs might has been caused by abnormal functions of Sertoli cells as well as Leydig cells.     

The kinetics of hemopexin and alpha1-acid glycoprotein levels induced by injection of inflammatory agents in chickens.

The acute phase response to inflammation induces changes in the secretion of hepatic proteins. To examine the time course of an acute phase protein response in broiler chickens, the plasma levels of hemopexin (HX) and alpha1-acid glycoprotein (AGP) and liver HX mRNA were measured at various time points from 3 hr to 336 hr after an intraabdominal injection of either lipopolysaccharide (LPS), complete Freund's adjuvant, incomplete Freund's adjuvant, phytohemagglutin, or mineral oil. Uninjected chicks served as controls. The accumulation of liver HX mRNA began within 3 hr of stimulation and peaked at 12 hr. Relative to control levels, plasma HX and AGP levels increased by 6-12 hr postchallenge and peaked at 24 hr. Complete Freund's adjuvant and LPS treatments induced the greatest increase in plasma HX (threefold; P < 0.05). Plasma levels of HX and AGP returned to control levels at 336 and 168 hr postinjection, respectively. A second experiment demonstrated that turpentine induced a similar AGP response as LPS and that albumin is a negative acute phase protein. The results suggest that plasma levels of HX or AGP could be used as an indicator of the systemic component of a local inflammatory response in chickens.     

Severe cardiopulmonary responses following metrizamide injection into the central canal of the spinal cord of two dogs

The severe cardiopulmonary and electrocardiographic changes occurring after inadvertent metrizamide (Amipaque) administration into the central canal of the spinal cord are described in two dogs. These changes were characterized by respiratory arrest and severe tachyarrhythmias. The successful resuscitative measures are described and the possible mechanisms of the responses are discussed.     

Detection of cone dysfunction induced by digoxin in dogs by multicolor electroretinography

It is difficult to detect discrete cone function with the present conventional electroretinography (ERG) examination. In this study, we developed contact electrodes with a built-in color (red (644 nm), green (525 nm), or blue (470 nm)) light source (color LED-electrode), and evaluated an experimental model of digoxin in the dog. First, 17 normal Beagle dogs were used to determine which electrode works well for color ERG measurement on dogs. Then, color ERG was performed on seven normal Beagle dogs at various points during a 14-day period of digoxin administration. A single daily dose of 0.0125 mg/kg/day, which is within the recommended oral maintenance dosage range for dogs, was administered orally for 2 weeks. Ophthalmic examination, measurement of plasma concentration of digoxin, and color ERG examination were performed. On first examination, amplitudes of all responses were significantly (P < 0.01) lower with the red, than with the blue and green electrodes during ERG recording. In ERG using the red electrode, the standard deviation was large. According to these preliminary results, the red electrode was not used in the experimental dog model with digoxin. In the digoxin administrated animals, no significant change was observed in the ophthalmic examination findings. The digoxin level increased steadily throughout the dosing period but was always within the therapeutic range for dogs. In rod ERG, no abnormalities were detected with any electrode. In standard combined ERG, decreased amplitude of the a-wave was detected with every electrode. In single flash cone ERG, prolongation of implicit time was detected by color ERG with the blue and green electrodes. In 30-Hz flicker ERG, decreased amplitude was detected only by color ERG with the blue electrode. The decreased amplitude and prolonged implicit time recovered after termination of digoxin administration. Cone dysfunction induced by digoxin in the dog was revealed by multicolor ERG using blue and green LED-electrodes. Multi-color ERG was useful for detecting cone type-specific dysfunction in the dog.     

Ultrasonographic evaluation of adhesions induced by incisional gastropexy in 16 dogs

A study was undertaken to evaluate the use of ultrasonography to assess the gastropexy site for permanent adhesion in clinical cases. Two groups, each comprising eight dogs, were studied, all 16 cases undergoing decompression, anatomical repositioning of the stomach and an incisional gastropexy after gastric dilatation-volvulus (GDV). Group 1 was set up as a prospective group in which ultrasonographic examinations were performed three times (mean three, 12 and 67 days) after surgery to evaluate the gastropexy region. The gastropexy site was assessed ultrasonographically at only one stage (mean 449 days after surgery) in the group 2 dogs. Criteria used to assess the usefulness of the ultrasonographic evaluation included the ability to identify the gastropexy site, to obtain measurements of the length and thickness of the site and to assess the ultrasonographic appearance of the different gastric wall layers. The average number of peristaltic contractions and degree of gastric filling were also evaluated. The fixation between the stomach and the abdominal wall was easily detected in all 16 cases. Ultrasonography proved to be a simple and non-invasive technique to assess the permanency of the gastropexy. The Incisional gastropexy was relatively easy to perform and induced permanent adhesions in all 16 dogs, without recurrence of GDV.     

盐酸异丙肾上腺素致犬慢性心肌缺血模型的制备

为制备盐酸异丙肾上腺素致犬慢性心肌缺血模型,将12只比格犬随机分为空白组及模型组,模型组犬按1.1 mg/kg剂量皮下注射盐酸异丙肾上腺素,空白组犬给予相应的生理盐水,于试验后不同时间检测血压、心率及心电图的改变。结果显示,与空白组犬相比,模型组犬血压降低(P0.01或P0.05),心率加快(P0.01或P0.05),ST段抬高(P0.01或P0.05);表明盐酸异丙肾上腺素诱导犬慢性心肌缺血模型成功建立。     

Pulmonary hypoplasia induced by liquid paraffin injection into fetal thoracic cavity with special reference to renal development in rats

The present study was designed to clarify lung-kidney interrelation in fetal rats. On fetal day 20, liquid paraffin (LP) was injected into fetal thoracic cavity to produce pulmonary hypoplasia. No significant difference in body and renal weights were noted between the LP injected and control fetuses. The weight of lung, however, was significantly lower in the LP injected fetuses than in the control ones. Histological examinations on the lung and kidney of the LP injected fetuses revealed that the lung was hypoplastic characterized by rich interstitium and reduced air spaces. In the kidney, mature types of glomeruli and profiles of proximal tubules near them were increased in number. Furthermore, strong expression of EGF immunoreactivity was noted in the apical cytoplasm of epithelium of the proximal tubules in the LP injected fetuses. These findings indicate that lung-kidney interrelation exists in fetal rats during late gestational days, and suggest that interruption of the lung development induces accelerated growth of the kidney in fetal rats.     

Echocardiographic changes induced by moderate to marked hypobaric hypoxia in dogs

Hypobaric (high-altitude) hypoxia is a physiologic cause of pulmonary hypertension, and alters left ventricular (LV) systolic and diastolic function. In the presence of tricuspid regurgitation, systolic pulmonary artery pressure can be measured noninvasively using the peak tricuspid regurgitation velocity and the Bernoulli equation. In the absence of measurable tricuspid regurgitation, severity of pulmonary hypertension may be estimated using two-dimensional, M-mode, and Doppler-derived parameters. To evaluate the usefulness of echocardiographic parameters for detecting mild-to-moderate pulmonary hypertension caused by moderate-to-marked hypoxia and to study the effect of high-altitude hypoxia on systolic and diastolic LV function in dogs, 19 Greenland dogs were examined at moderate altitude (2300 m) and high altitude (3500 m), and 10 Greenland control dogs were examined at 700-900 m. Evaluated parameters were pulmonary flow profile (shape, right ventricular acceleration time (RVAT), ejection time (RVET), RVAT/ET), peak mitral inflow velocities (LVE, LVA, LVE/A-ratio), LV % fractional shortening (FS), systolic time intervals (LVPEP, LVPEP/ET), and stroke volume index (SVI). Notching during deceleration was common in dogs at high altitude and in the control dogs, but not in dogs at moderate altitude. RVAT was shorter in dogs at high altitude compared with moderate altitude, but not compared with control dogs. Peak A-velocity was higher and E/A-ratio was lower in dogs at high altitude compared with moderate altitude and control dogs. FS was increased in dogs at high altitude compared with moderate altitude, and LVPEP and LVPEP/ET were shorter in the dogs at high altitude compared with moderate altitude and control dogs. In conclusion, significant differences in pulmonary flow profiles and systolic and diastolic parameters can be observed echocardiographically in dogs at different degrees of hypobaric hypoxia. However, overlap between the groups compromises their usefulness for diagnosing and estimating the degree of mild-to-moderate pulmonary hypertension in individual dogs.     

Tetramine cupruretic agents: a comparison in dogs

The cupruretic effects of 2 tetramine (N,N'-bis (2-aminoethyl) alkane diamine) chelators were examined in healthy dogs fed a commercial dog food containing 12.2 micrograms of copper/g of dry diet. Two groups of 3 dogs each were given either 300 mg of 2,2,2-tetramine tetrahydrochloride or 2,3,2-tetramine tetrahydrochloride for 23 consecutive days. Serum and 24-hour urine samples obtained before drug administration and during therapy were analyzed for copper, zinc, and iron concentrations. Both tetramines produced a significant cupruresis without significant changes in serum copper or in serum or urine zinc and iron concentrations. The 2,3,2-tetramine tetrahydrochloride produced a 4- to 9-fold greater cupruresis than did 2,2,2-tetramine tetrahydrochloride and resulted in a daily loss of more than 2 mg of copper in the urine. The dogs had no laboratory or clinical evidence of toxic side effects to either cupruretic agent during the treatment period. The results of the present study indicate that 2,3,2-tetramine should be an effective decoppering drug for use in dogs.     

Comparison of histamine release induced by morphine and oxymorphone administration in dogs

Cardiovascular effects (vasodilatation, hypotension) of morphine administration have been attributed to central actions and peripheral histamine release. In the study reported here, we compared plasma histamine (Hm) concentrations after morphine sulfate and oxymorphone HCl administration in conscious dogs. Five healthy adult dogs (mean body weight, 10.1 kg) were randomly administered morphine (2 mg/kg of body weight, IV) or oxymorphone (0.2 mg/kg, IV) by a 5-second bolus injection at weekly intervals. Venous blood samples (5 ml) were collected from jugular veins before and at 1, 2, 5, 15, 30, and 60 minutes after drug administration. Behavioral changes were recorded. Plasma was analyzed by a radioenzymatic technique, using purified histamine N-methyltransferase as an enzyme catalyst (sensitivity of assay, 40 pg Hm/ml). Mean base-line Hm value for all dogs was 0.55 ng/ml. The mean Hm value was significantly higher (P less than 0.05) than the base-line value at 1, 2, 5, 15, and 60 minutes after morphine administration (531.4, 251.0, 113.0, 31.5, and 1.0 ng of Hm/ml, respectively), but there were no significant increases in histamine values from base-line values at any time after oxymorphone administration. All dogs given morphine and 1 dog given oxymorphone showed excitatory behavior; 2 dogs given morphine and 3 dogs given oxymorphone salivated profusely.     

Ultrasound-guided parasternal injection in dogs: a cadaver study

ObjectivesTo describe the technique of performing an ultrasound-guided distal parasternal intercostal block and to determine the distribution of two volumes of methylene blue dye solution injected in canine cadavers.Study designProspective cadaver study.AnimalsA group of seven canine cadavers weighing 12–34 kg.MethodsThe space between the transversus thoracic and the internal intercostal muscles is a virtual cavity. Ultrasound-guided injections in the distal (parasternal) intercostal space were performed using dye solution at 0.05 mL kg^–1 in each intercostal space from the second to seventh (LV, low volume, six injections per dog) in one hemithorax, and 0.1 mL kg^–1 in the third, fifth and seventh intercostal spaces (HV, high volume, three injections in each dog) on the contralateral side. Anatomical dissection was carried out to describe dye spread characteristics and staining of intercostal nerves.ResultsThe ultrasonographic landmarks for injection were identified in each cadaver. In the LV group the solution was found in every intercostal space (36/36), whereas the HV injection stained six intercostal spaces in two dogs, five in two, and in two dogs the solution was found in four and three spaces, respectively, demonstrating multisegmental distribution. Intrapleural staining was observed after two injections.Conclusions and clinical relevanceUltrasound-guided injection of 0.05 mL kg^–1 at the distal intercostal space resulted in staining of the intercostal nerve in all dogs when performed in every space and may be an appropriate alternative to previously reported techniques. A single injection of 0.1 mL kg^–1 may anaesthetize more than one intercostal nerve, but not consistently. Clinical investigations are warranted to better characterize and to refine this locoregional technique.     

Penetration of tinidazole into the gingival crevicular fluid in dogs

Tinidazole was administered as a single oral dose of 15 mg kg-1 to 12 dogs, and its concentration in the plasma and gingival crevicular fluid (GCF) was measured at one and two hours by high performance liquid chromatography. Tinidazole was detectable in GCF in five dogs at one hour (6.8 +/- 2.6 micrograms ml-1) and in six dogs at two hours (9.2 +/- 1.4 micrograms ml-1) and in all plasma samples. In those animals with no detectable tinidazole in GCF, either the concentration of tinidazole in plasma was low or the volume of the GCF sample was insufficient for determination. The observed tinidazole levels in GCF exceeded the minimal inhibitory concentration values for most anaerobic oral bacteria.     

Radiographic findings in induced bacterial pyelonephritis in dogs

Unilateral bacterial pyelonephritis was induced in nine dogs. The upper urinary tracts of these and six control dogs were evaluated by excretory urography prior to and 9 to 10 days following experimental manipulations. Two of the dogs with unilateral pyelonephritis and one control dog were evaluated at intervals throughout a 58-day period. At necropsy, all nine inoculated kidneys were infected, one experimental dog had bilateral pyelonephritis, and one control dog had unilateral pyelonephritis. Most of the infected kidneys had abnormal radiographic changes 9 to 10 days after induction of infection. There was no statistically significant radiographic change in size of infected kidneys at 9 to 10 days. Seven of the 11 infected kidneys and 7 of the 9 inoculated kidneys had renal pelvic and ureteral dilatation. Of the nine dogs with unilateral pyelonephritis, six had decreased opacity of contrast medium in the collecting system and of the vascular nephrogram on the infected side. The size of infected kidneys decreased progressively during the 58-day period. In one of the two dogs evaluated throughout the period, the collecting system of the infected kidney remained dilated; in the other, it returned toward normal size.     

An increase in metabolic acidosis induced by chloralose anaesthesia in dogs after sino-vagal denervation

Chloralose anaesthesia in dogs increased the H+ ion concentration significantly from its reference values. The findings favoured that it was most probably engendered through anaesthetic depression of neural centre regulating H+ ion concentration of blood. Such increase was largely contributed by a significant increase in its metabolic fraction. A further increase of metabolic fraction after separate and joint section of carotid sinus nerves and vagi indicated their holding effect. The section of carotid sinus nerve induced greater increase in this fraction than that of vagi. It indicated differences between the two nerves in their metabolic fraction controlling influence. Hyperpnoea after vagi section decreased the carbonic acid fraction, whereas marginally reduced ventilation after carotid sinus nerve section increased the carbonic acid fraction. Moreover, the overall changes in H+ ion concentration followed the changes in carbonic acid fraction. The present study suggested that the depressive effect of chloralose anaesthesia on H+ ion controlling neural mechanism could be largely determined by degree of increase in its metabolic fraction.