A comparative study of induction of estrus and ovulation by three different intravaginal devices in ewes during the non-breeding season

The aim of the present study was to compare three methods of estrus synchronization in ewes during the non-breeding season. Forty-two ewes were randomly grouped for three treatments with different intravaginal devices for 12 days: Group A) CIDR, Group B) Self-made P sponge, Group C) MAP (medroxyprogesterone acetate) cream sponge. Furthermore, all groups were divided into two treatments with (R) or without ram presence to examine the "ram effect". Blood was collected from all treated ewes, and progesterone (P(4)), estradiol 17-beta (E(2)) and luteinizing hormone (LH) concentrations were measured by enzyme-immunoassay. All ewes showed estrus behavior between Day 0 to 3 after device removal, and the mean onset times of their estrus were 23.0, 33.0 and 21.0 h for Groups AR, BR and CR, respectively. On Day 5 as examined by laparoscopy, the ovulation rates (and number of ovulated ewes) were 1.45 (11/11), 1.25 (12/14) and 1.21 (14/14) for Groups A, B and C, respectively. In Group C, the time to LH surge was significantly (P<0.05) later (32.4 h) than those in Groups A (27.0 h) and B (25.5 h). Ram presence did not affect the number of ovulated ewes, ovulation rate or time to LH surge. The ram introduction group had significantly (P<0.05) lower E(2) concentrations during the period from 0 h to 36 h than the groups without ram presence. These results suggest that the self-made P sponge or MAP cream sponge was effective as well as CIDR, and ram introduction was not necessary, for induction of estrus and ovulation during the non-breeding season.     

Toluene Exposure Leads to a Change in Expression Patterns of β Defensins in the Mouse Tracheal Epithelium

Defensins are generally implicated in the quick resistance of epithelial surfaces to microbials; however, recent reports have indicated that defensins also have unknown purposes in relation to noninfectious diseases. In this study, the localization patterns of anti-microbial peptides, β defensins (BDs), in the tracheal epithelium of male C3H mice under exposure to toluene were analyzed by immunohistochemistry. Mice were exposed one to ten times to toluene for 30 min by nose-only inhalation. Expression of BDs was revealed by immunohistochemistry in serial sections of trachea after the final exposure. Expression of BD-1 was usually observed at almost the same levels in all exposure groups, and expression of BD-2 was observed in the control group; however, the signals for BD-2 decreased gradually with frequency of exposure. In the group exposed ten times, expression of BD-2 decreased to far lower than that of the control group. No expression of BD-3 was detected in any groups. Interestingly, expression of BD-4 increased to the maximum in the group exposed four times and decreased to a level lower than that of the control in the group exposed ten times. The results of the present study indicated that toluene gas might change the expression pattern of BDs in the tracheal epithelial cells. The oscillation of expression of BD-4 was quite characteristic and might contribute to morphological damage in on the epithelial cells.     

En block resection of a large hepatocellular carcinoma involving the caudal vena cava in a dog

A 13-year-old neutered female Shih Tzu was referred for investigation of a cranial abdominal mass. Investigations including conventional radiography, abdominal ultrasonography and computed tomography confirmed the mass in the caudate lobe of the liver. As a collateral vein originating from the caudal vena cava (CVC) communicated with the azygos vein, the CVC was ligated and transected cranial to the right renal vein and cranial to the mass under temporary occlusion of the thoracic descending aorta and posthepatic CVC. The mass combined with the CVC was excised. The mass was confirmed as hepatocellular carcinoma (HCC). This report describes the first case with successful en bloc resection of a large HCC involving the CVC in a dog.     

Experimental studies on the oxygen tension in the myocardium and changes of cardiac function in hypoxia

Using adult mongrel dogs, experiments were performed to elucidate the relationship between the changes in the myocardial oxygen tension (PmO2) in anoxia and disturbances of cardiac function. Dogs, forced to inspire 100% N2, suffered from a respiratory arrest after 5 min, and developed acute anoxia. However, by 100% O2 inhalation 2 min after the onset of the respiratory arrest, the anoxia rapidly resolved. The arterial oxygen tension (PaO2), left intra ventricular oxygen tension (PLVO2) and PmO2 showed the most pronounced fall 2 min after the respiratory arrest induced by N2 inhalation. The arterial carbon deoxide tension (PaCO2) decreased until the respiratory arrest, after which it started to rise. When inhalation of 100% O2 was initiated at the anoxia, the PaO2, PLVO2 and PmO2 recovered within 1 min followed by a rise beyond the baseline value. Left ventricular end-diastolic pressure (LVEDP), left atrial mean pressure (LAm), left ventricular systolic pressure (LVSP), aortic mean pressure (Aom), maximum rate of force development by left ventricle (LVmax.dp/dt), total peripheral resistance (TPR), cardiac output (CO) and heart rate (HR) were measured. At the onset of anoxia, these parameters decreased sharply. When inhalation of 100% O2 was initiated within 2 min of the respiratory arrest, these disturbances of cardiac function recovered rapidly. The fall of PmO2 plays an important role in the impairment of cardiac function.     

High performance liquid chromatographic determination of trimethoprim residues in egg yolk and albumen in a feeding experiment

In a feeding experiment, the residues of trimethoprim (TMP) in egg yolk and albumen were determined by high performance liquid chromatography (HPLC). Laying hens were divided into four groups. The first group was designated as control and fed with TMP free diet during the experimental period. The second, third and fourth groups were administered with the feeds containing 4 p.p.m., 16 p.p.m. and 56 p.p.m. TMP, respectively, for 19 days and, thereafter, fed with TMP free diet. TMP was mainly found in yolk in all the three administered levels. In the medication period, the average concentration of TMP in the yolk of the second, third and fourth groups was 0.05, 0.25, and 0.90 p.p.m., respectively. After withdrawal of medication, the residues of TMP in yolk in the second, third and fourth groups decreased below the detection limit at 0.02 p.p.m. on days 4, 9, and 11, respectively.     

Effect of fat content on sensory characteristics of marbled beef from Japanese Black steers

To analyze the sensory characteristics of meat samples with a crude fat content between 23.8% and 48.6% taken from 34 Japanese Black steers, we grilled the meat and subjected it to analytical sensory evaluation. We also measured the amounts of moisture, protein, nucleic acid and glutamic acid. An increase in crude fat content increased the tenderness, juiciness, and fattiness in the meat quality evaluation. An increase in crude fat content reduced the crude protein and moisture contents; it also slightly reduced the nucleic acid and glutamic acid contents, although when the reductions in these umami components were assessed relative to the moisture content they changed little. Increasing the fat content up to a certain point greatly enhanced the umami intensity and beef flavor intensity in the meat quality evaluation and raised the overall evaluation score; the peak of the appropriate crude fat content for these purposes was about 36%.     

Search for an index for the taste of Japanese Black cattle beef by panel testing and chemical composition analysis

To search for an index for chemical composition related to superior taste in Japanese Black beef, we conducted panel tests and analyzed the chemical composition of seven beef brands. Thirty‐five sirloin beefs from five heifers were used in this study, sold under seven beef brands graded as more than A4 on the Japanese Meat Grade scale. The chemical composition analyses assessed both raw and roasted meat, the latter of which was roasted under the same conditions as those used for the panel test. Results of the panel test and chemical composition analyses revealed that fatty acid composition, sugar content, adenosine triphosphage (ATP)‐related compounds, amino acid composition and odor composition in the sirloin meat differed among beef brands. Furthermore, the correlations of chemical compositions between roasted and raw meat were significantly high. Sugar content and ATP‐related compounds in roasted meat were significantly correlated with the item ‘overall evaluation’ of the panel test. ATP‐related compounds, such as inosinic acid, carnosine and taurine, in roasted and raw meat were correlated significantly with the item ‘umami intensity’ of the panel test. These results suggest that the composition of these components is important for an index related to the overall evaluation of beef.