Acoustic evaluation of the vertical distribution of dwarf ayu Plecoglossus altivelis altivelis in Lake Biwa

SUMMARY: The vertical distribution of dwarf ayu Plecoglossus altivelis altivelis in the pelagic waters of Lake Biwa was evaluated from June to September in 1995–97 from eight acoustic surveys using a quantitative echosounder. In each survey, echoes from a depth range of 3 m to the sea bottom were collected at a station every 2.7 s for 24 h together with measurements of vertical profiles of water temperature and chlorophyll-a. The ayu's echoes were identified using an underwater video camera. The ayu were observed near the maximum chlorophyll-a depth and above the thermocline. Their density was highest at depths of 4–11 m with 2–4 individuals/m ³ and was almost zero below 20 m. Echo signs were recorded as having a frequent duration of more than 1 h at night, whereas were of a shorter duration in the day. The fish stay in the epilimnion during the day without any clear vertical migration, but are distributed more uniformly at night. The advantages of remaining in the epilimnion are discussed in terms of food availability and predator avoidance.     

Histochemical studies on the dependence of secretory function of the major vestibular gland (Bartholin's gland) on ovarian steroid hormones in the cat.

The dependency of the secretory function of the feline major vestibular gland (Bartholin's gland) on the ovarian steroid hormones was studied histochemically. After estrogen (estradiol-17 beta or diethylstilbestrol), progesterone or a combination of these was administered to cats which were previously ovariohysterectomized, the major vestibular glands were removed, embedded in paraffin, sectioned, and stained by alcian blue, periodic acid-Schiff or peroxidase-labeled lectin (peanut agglutinin and wheat germ agglutinin). The vividly positive reactions to the stainings applied were observed in the secretory epithelial cells of the major vestibular glands in the estrogen treated animals. The dependency of the secretory function of the major vestibular glands on the estrogen was demonstrated in this study.     

Effect of bilateral cecal ligation on use of dietary energy in growing chickens

In order to determine the role of the cecum on energy use in growing chickens, metabolizability of the dietary energy and energy expenditure were examined in the week following bilateral ligation and washing out of the cecum. Apparent metabolizable energy (AME) values were 14.30 and 13.69 kJ/g air‐dry matter for sham‐operated and cecally ligated chickens, respectively. These values were found to be significantly different (P < 0.05). Although AME intake and fasting heat production were decreased by cecal ligation, the distribution of AME (measured as fasting and feeding heat production, as well as heat increment and energy retention, as a proportion of AME intake) was not affected. These results suggest that the cecum helps chickens extract AME from corn‐soybean type diets with little, if any, effect on AME use, based on the present study of growing chickens in the week following cecal ligation.     

Apoptosis in the porcine uterine endometrium during the estrous cycle, early pregnancy and post partum

The mammalian uterus changes dramatically during the estrous cycle, pregnancy, and involution post partum. Dynamic changes in the uterine endometrium are a type of homeostasis and proceed with proliferation and exclusion of cells. Homeostasis of the uterus is closely related to apoptosis involving various hormones and cytokines. The objective of the present study was to determine the morphological features and occurrence of apoptosis in the porcine endometrium during the estrous cycle, early pregnancy, and post partum. Cyclic changes in the morphology of the surface epithelium were observed during the estrous cycle. The heights of surface epithelia were significantly high on day 4 of the estrous cycle and the early pregnancy. The heights of the surface epithelium remained low from days 1 to 31 post partum. We then used terminal deoxynucleotidyl transferase-mediated biotinylated deoxyuridine triphosphate nick end-labeling (TUNEL) of the 3'-terminal of fragmented DNA, which is effective for detection of apoptosis in various tissues. We found that apoptosis in the porcine endometrium contributed to homeostasis of the endometrium during the estrous cycle through control of cell proliferation and exclusion. Conversely, apoptosis on days 4 and 8 of gestation before the implantation window depended on the plasma estrogen and progesterone levels; however, suppressive homeostasis of apoptosis occurred at the time of implantation on days 15, 18 and 21 of gestation. Our study is the first to demonstrate apoptotic cell death in the porcine endometrium directly by TUNEL method. The results strongly suggest that uterine homeostasis is mainly controlled by apoptosis during the estrous cycle and early pregnancy.     

International harmonisation of anthelmintic efficacy guidelines

The "International Co-operation on Harmonisation of Technical Requirements for Registration of Veterinary Medicinal Products (VICH)" is an international programme of co-operation between regulatory authorities and the animal health industries of the European Union, Japan, and the United States of America which aims to harmonise the technical requirements for the registration of veterinary medicinal products. Australia and New Zealand participate as active observers. The objective of the present paper is to present the guidelines established by the working group on Anthelmintic Efficacy Guidelines: (1) efficacy of anthelmintics: general requirements (VICH GL7); (2) efficacy of anthelmintics: specific recommendations for bovines (VICH GL12); (3) efficacy of anthelmintics: specific recommendations for ovines (VICH GL13); (4) efficacy of anthelmintics: specific recommendations for caprines (VICH GL14). These guidelines do not consist of rigid stipulations, but make clear recommendations on the minimal standards needed. To the veterinary profession, livestock producers and animal owners, harmonisation should mean quicker access to safer and more effective veterinary anthelmintics. In general, products should be relatively more affordable because of the reduction in registration costs and efficient use of resources by the regulatory authorities.     

Trophinin is expressed in the porcine endometrium during the estrous cycle

We investigated endometrial expression of trophinin mRNA and protein, homophilic cell adhesion molecules, during the estrous cycle of gilts. An immunopositive reaction for trophinin was observed in the luminal and glandular epithelia of the endometrium at all stages of the estrous cycle, but not in endometrial stromal cells or the myometrium. A partial coding sequence of porcine trophinin was similar to sequences in humans and mice, with homologies of 75% and 70%, respectively. As in humans and mice, the trophinin gene is expressed in the endometrium. Trophinin, however, is expressed in the endometrium of the pig throughout the estrous cycle, higher expression levels were observed at some points of the luteal phase, as in humans. These findings suggest that regulation of trophinin gene expression in the pig is different from that in mice, but similar to that in humans. Furthermore, the present results suggest that the pig might be a suitable model for studying the physiological importance of trophinin in early pregnancy in humans.     

Three dogs under 2 years of age with heartworm caval syndrome

Heartworm caval syndrome (CS) occurred in three dogs under 2 years of age. A 23-month-old dog was recovered by surgical and medical treatments, but the other 2 dogs (15 and 21 months old) died. Necropsy demonstrated 12 heartworms in the 15-month-old dog and 8 worms in the 21-month-old dog. Histopathologically, pulmonary arterial embolism caused by dead worms and thrombi were observed in these cases. The findings suggested that CS could develop regardless of canine age and worm burden if pulmonary arterial embolism related to worm death or thrombus formation were induced.     

International harmonisation of anthelmintic efficacy guidelines (Part 2).

The "International Co-operation on Harmonisation of Technical Requirements for Registration of Veterinary Medicinal Products (VICH)" is an international programme of co-operation between regulatory authorities and the animal health industries of the European Union, Japan and the United States of America which aims to harmonise the technical requirements for the registration of veterinary medicinal products. Australia and New Zealand participate as active observers. The objective of this second paper is to present additional guidelines established by the Working Group on anthelmintic guidelines: (1) efficacy of anthelmintics: specific recommendations for equine (VICH GL15), (2) efficacy of anthelmintics: specific recommendations for porcine (VICH GL16), (3) efficacy of anthelmintics: specific recommendations for canine (VICH GL19), (4) efficacy of anthelmintics: specific recommendations for feline (VICH GL20) and (5) efficacy of anthelmintics: specific recommendations for poultry (VICH GL21). These guidelines do not consist of rigid stipulations, but make clear recommendations on the minimal standards needed. To the veterinary profession, livestock producers and animal owners, harmonisation should mean quicker access to safer and more effective veterinary anthelmintics. In general, products should be relatively more affordable because of the reduction in registration costs and efficient use of resources by the regulatory authorities.     

Evaluation of intracranial pressure by transcranial Doppler ultrasonography in dogs with intracranial hypertension

Transcranial Doppler ultrasonography (TCD) has been used to confirm changes in cerebral hemodynamics. In this study, we investigated whether the parameters for the basilar artery measured by TCD were correlated with the intracranial and cerebral perfusion pressures in extreme intracranial hypertension. An intracranial hypertension model was produced in seven dogs by inflating a balloon inserted into the epidural space. The resistance index was compared with the corresponding intracranial pressure and cerebral perfusion pressure values during intracranial hypertension. A significant correlation was recognized between the resistance index and cerebral perfusion pressure. Therefore, measurement of the basilar artery by TCD in the dog with intracranial hypertension is useful in estimating the intracranial circulation in cases where the measurement of intracranial pressure is not available or not indicated.