Pneumonia in horses induced by intrapulmonary inoculation of Streptococcus equi subsp. zooepidemicus

To evaluate the possibility that Streptococcus equi subsp. zooepidemicus (S.z) the causative bacterial agent of equine shipping fever pneumonia (ESFP), as well as to investigate its pathogenesis, 10 horses (seven Thoroughbreds and three Anglo-Arab species, ranging from 2-4 years in age) were experimentally inoculated, via an endoscope, into bronchus of the lung lobe with a dose of 30 ml of 1-7 x 10(8) CFU/ml of S.z. After inoculation, autopsy and pathological examinations were sequentially conducted 30 min, 1, 2, 3, 4, 17, 20 hr and 2 weeks later. Pneumonia induced by the intrapulmonary inoculation of S.z was characterized by small purulent pneumonic foci in the inoculated areas. With the lapse of time, these foci developed into serous hemorrhagic pneumonia, hemorrhagic purulent pneumonia, and then purulent, coagulation necrotic pneumonia. These pathomorphological characteristics of experimental pneumonia closely resemble those naturally occurring ESFP. There is strong evidence that S.z. is implicated as a causal factor in ESFP. S.z. grew in the mucus, exudate, and pulmonary effusions. Further, the bacteria showed resistance against phagocytosis by pulmonary alveolar macrophages (PAM) and neutrophils. Inhibition of PAM and neutrophil function is considered to be important in the development of pneumonia. With the progression of the disease, the neutrophils often adhered to the endothelial surface of the alveolar capillary lumen and played a role in generating coagulation necrosis of lung tissues.     

Isolation of Cryptosporidium andersoni Kawatabi type in a slaughterhouse in the northern island of Japan

Fecal samples were collected from 325 adult cattle and 108 pigs in a slaughterhouse in Hokkaido, the northern island of Japan. Five adult cattle were found to be positive for oocysts of Cryptopsoridium (1.5%). The oocysts were morphologically similar to those of Cryptosporidium andersoni. The partial sequence of the 18S rRNA gene of the isolate was 100% identical with that of the C. andersoni Kawatabi strain. SCID mice were infected after oral administration. Based on the morphology of the oocysts, the sequence of the 18S rRNA gene and the infectivity to SCID mice, the isolate was concluded to be of the same type as the C. andersoni Kawatabi strain that has been isolated in Honshu, the main island of Japan.     

High plasma estradiol-17beta levels in dogs with benign prostatic hyperplasia and azoospermia

The semen quality of 22 dogs (4 to 7 years old) with benign prostatic hyperplasia (BPH) was examined at the hospital of our university, and 4 of the 22 BPH dogs were diagnosed as azoospermic. The mean peripheral plasma estradiol-17beta (E2) level (17.3 pg/ml) of the 18 BPH dogs with spermatogenic function was higher than that of 5 normal male dogs and their mean T level (1.7 ng/ml) was lower. The mean E2 level (27.3 pg/ml) of the 4 BPH dogs with azoospermia was significantly higher than the value in the BPH dogs with spermatogenic function (P<0.01), and the mean T level (1.1 ng/ml) was significantly lower (P<0.05). Five normal male dogs were given 10 intramuscular injections of estradiol benzoate (E2B) 5 microg/kg, at 3-day intervals to investigate the relationship between high plasma E2 levels and the cause of the BPH and azoospermia. Their testes and prostates were measured and biopsied both before and 30 days after the start of E2B injections. At 30 days after the start of the E2B injections, the mean peripheral plasma T levels had decreased by half, and the mean testicular volume had decreased to 88% of original volume. The numbers of spermatocytes, spermatids, and spermatozoa in the seminiferous tubules of all of the dogs were significantly lower (P<0.05, 0.01). In addition, the mean prostatic volume increased to 130%, the mean height of the glandular epithelium decreased, and the glandular lumen became increased in diameter. These findings indicate that both BPH and serious spermatogenic dysfunction may be simultaneously induced by protracted high plasma E2 levels in dogs.     

Pathogenicity of serotype 8 fowl adenovirus isolated from gizzard erosions of slaughtered broiler chickens

The pathogenicity of serotype 8 fowl adenovirus (FAV), isolated from gizzard erosions of slaughtered broiler chickens, was investigated. In experiment 1, 29 5-day-old specific-pathogen-free (SPF) chickens were inoculated with the isolates of serotype 8 FAV, M013 (group 1) or G0054 (group 2) strain, via an oral route. There were no clinical signs in any of chickens after inoculation, and mild gizzard erosions were observed macroscopically and microscopically in three inoculated chickens of group 2. FAV was recovered from gizzards and rectums but was not recovered from pancreas and livers from chickens in both inoculated groups. In experiment 2, 27 1-day-old SPF chickens were inoculated with the G0054 strain by intramuscular route. Five, 6, and 3 inoculated chickens died on days 3, 4, and 5 postinoculation (PI), respectively. Four, 3, 1, and 1 inoculated chickens became moribund with severe clinical signs such as ruffled feathers, severe depression and closed eyes from days 3 to 6 PI, respectively. Macroscopically, the common characteristic of the gross lesions of dead chickens and euthanized moribund chickens was discoloration of liver. FAV was recovered from the gizzard, liver, pancreas and rectum. Virus titers in the liver and pancreas were high until day 6 PI. Histologically, necrotizing hepatitis and pancreatitis with intranuclear inclusion bodies were observed in the inoculated chickens. These results indicate that some strains of serotype 8 FAV are able to reproduce not only gizzard erosion by oral inoculation but inclusion body hepatitis (IBH) by intramuscular inoculation.     

Antihypertensive properties of spinach leaf protein digests

Leaf protein containing approximately 50% rubisco (ribulose bisphosphate carboxylase/oxygenase) was obtained from fresh spinach leaf with the use of a simple extraction method. Pepsin and pepsin-pancreatin digests of spinach leaf protein have potent angiotensin-I converting enzyme inhibitory properties with IC(50) values of 56 and 120 microg/mL, respectively. Both digests of leaf protein have antihypertensive effects after oral administration to spontaneously hypertensive rats (SHR) with minimum effective doses of 0.25 and 0.5 g/kg, respectively. The maximum antihypertensive effect for the pepsin digest was observed 4 h after oral administration, while for the pepsin-pancreatin digest, the maximum effect was observed 2 h after oral administration. Undigested spinach leaf protein did not exert any significant antihypertensive effect after oral administration to SHR at doses of 0.5 and 1 g/kg. Obtained results show that the pepsin digest of leaf protein may be useful in treatment of hypertension.     

Efficacy of vaccination with porcine reproductive and respiratory syndrome virus following challenges with field isolates in Japan

The objective of this study was to evaluate the influences of genetic and antigenic variations in field isolates of porcine reproductive and respiratory syndrome virus (PRRSV) on vaccine efficacy. Four-week-old pigs were vaccinated with a commercial modified live virus vaccine. Four weeks after vaccination, pigs in both the vaccinated group and the non-vaccinated group were challenged intranasally with 10(7) TCID(50) of PRRSV wt-11 (Experiment 1) or PRRSV wt-7 (Experiment 2). Based on genome sequencing of ORF5 and cross neutralization test results, PRRSV wt-11 is similar to the vaccine strain, whereas wt-7 is distinct from the vaccine strain. In the vaccinated challenged groups, clinical signs were less severe, the mean rate of weight gain was greater, and gross lung lesions were less severe when compared with the non-vaccinated challenged groups in both experiments. In Experiment 1, the virus was isolated from serum at 3 days post-challenge, and the mean virus titers in broncho-alveolar lavage fluids (BALF) and tissues were lower in pigs in the vaccinated challenged groups compared with those in the non-vaccinated challenged group. In Experiment 2, virus isolation from serum, BALF and tissues showed no significant differences between the groups. These results suggest that commercial PRRSV vaccine could be effective in reducing clinical disease following a challenge with field isolates of PRRSV. However, with regards to virological protection, the efficacy of the vaccine may be affected by the nature of the PRRSV isolates.     

Immunohistochemical distribution of viral antigens in pigs naturally infected with porcine teschovirus

A distribution of porcine teschovirus (PTV) antigens in pigs naturally infected with PTV is presented using the method of immunohistochemical examination. In the nervous system, PTV antigens were found in the cytoplasm of neuronal cells and glial cells distributed in the spinal ventral horn and brain stem, and also in the cytoplasm of ganglion cells in the spinal ganglion. No antigens were seen in the cerebral hemisphere. In the nervous system, the distribution of PTV antigens was consistent with lesions characteristic of nonsuppurative encephalomyelitis. In the other examined organ, PTV antigens were observed in bronchiolar epithelial cells in the lung, hepatocytes in the liver, epithelial cells in the tonsils and the myenteric nerve plexus in the small and large intestine.