We examined the effect of stroma-derived factors, hepatocyte growth factor (HGF) and leptin, on morphological differentiation of bovine mammary epithelial cells (BMEC) in collagen gel three-dimensional culture in vitro. BMEC treated with HGF, but not leptin, formed duct-like organoids. The formation of organoids by HGF was enhanced by treatment with a mixture of insulin, cortisol and prolactin, while BMEC treated with the mixture alone did not produce the organoid. In contrast, the formation of organoids by HGF was dose-dependently inhibited by simultaneous addition of leptin, regardless of the presence or absence of the hormone mixture. These results suggest that stroma-derived factors intricately regulate mammary epithelial morphogenesis.

An R664X nonsense mutant AE1 is responsible for dominant hereditary spherocytosis in cattle and is degraded by the proteasomal endoplasmic reticulum-associated degradation. The present study demonstrated that R664X AE1 translated in vitro had the trypsin-sensitve site identical to that of the wild-type AE1. The P661S/R664X mutant containing a possible N-glycosylation site at Asnsup(660) showed an increase in size by 3 kDa both in the cell-free translation system and in transfected HEK293 cells. Moreover, steady state levels of R664X and P661S/R664X in HEK293 cells were markedly increased in the presence of a proteasome inhibitior. These findings indicate that the truncated C-terminal region of R664X AE1 has lumenal localization in the endoplasmic reticulum and is not accessible to proteasomal machineries in the cytosol.

Anthrax is endemic in Western and North-western Provinces of Zambia. The disease occurs throughout the year and impacts negatively on the economy of the livestock industry and public health in Zambia. During 1989-1995, there were 1,626 suspected cases of anthrax in cattle in Western province and of these 51 were confirmed. There were 220 cases of human anthrax cases in 1990 alone and 248 cases during 1991-1998 with 19.1% and 7.7% case fatality rates, respectively. Interplay of the ecology of affected areas and anthropogenic factors seem to trigger anthrax epidemics. Anthrax has drawn considerable attention in recent years due to its potential use as a biological weapon. In this paper, the history, current status and approaches towards the control of the disease in Zambia are discussed. Quarantine measures restrict trade of livestock and exchange of animals for draught power resulting in poor food security at household levels. Challenges of anthrax control are complex and comprise of socio-political, economical, environmental and cultural factors. Inadequate funding, lack of innovative disease control strategies and lack of cooperation from stakeholders are the major constraints to the control of the disease.

To develop ELISA to detect antibodies specific to Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis), the carboxyl termini of the 34 kDa proteins of M. paratuberculosis and Mycobacterium avium subsp. avium (M. avium) were expressed in Escherichia coli expression system. Antibodies specific to M. paratuberculosis were detected with the truncated 34 kDa protein of M. paratuberculosis in ELISA after pre-absorption of serum samples with the truncated 34 kDa protein of M. avium. All the serum samples from cattle confirmed to be infected with M. paratuberculosis were positive and those from healthy cattle were negative in the present ELISA system. These results indicate that the established ELISA detects antibodies specific to M. paratuberculosis with high specificity and sensitivity and is an useful tool for the screening of Johne's disease.

Genotypes and subgenotypes of bovine viral diarrhea virus (BVDV) field isolates from Japan, Germany and the United States of America (USA) were identified, and the prevalent pattern of BVDV in individual countries was estimated genetically. Subgenotypes were determined based on phylogenetic analyses of nucleotide sequences of a part of the E2-coding gene of BVDV. Forty-five, 61 and 56 BVDV strains were isolated from naturally infected cattle in Japan, Germany and USA, respectively, between 1980 and 2003. The most prevalent BVDV in these three countries was BVDV - 1b. The second most prevalent BVDV strains were 1a, 1d and BVDV - 2 in Japan, Germany and USA, respectively. The most prevalent subgenotype 1b in each country constructed individual small clusters in the subgenotype 1b branch in the phylogenetic tree. Although cattle and/or cattle products were moving among the three countries as part of international trade, the distribution of BVDV in the field in each country showed long-standing individual patterns.

Substance P (SP) is colocalized with ACh in splanchnic nerves that innervate into adrenal medulla and the peptide has been shown to inhibit nicotinic agonists-induced catecholamine secretion. To elucidate the effects of SP on cytosolic Ca(2+) dynamics, the present study was conducted using fura-2-loaded isolated bovine adrenal chromaffin cells. Stimulation of the cells with nicotine (10-100mu-M) produced a rapid rise of cytosolic Ca(2+) concentration ([Ca(2+)]i), the peak level of which increased in a dose-dependent manner, followed by a gradual decay. In the presence of 10mu-M SP, the dose-response relationship of the peak levels shifted downward. Quantitative analyses implied that SP inhibits the nicotine-induced Ca(2+) influx in a noncompetitive manner. Nicotinic acetylcholine receptor is composed of two major functional domains: an agonist-binding site and an ionophore or channel domain. Agonist binding activates ionophore / channel domain and causes mainly Na(+) influx. This Na(+) influx depolarizes the cell and activates voltage-dependent Ca(2+) channels. Based on this fact, the present results indicate that SP dose not block nicotine binding sites but interferes with other sites of nicotinic receptor / channel molecule, most probably a channel domain. It was suggested that SP colocalized with ACh in splanchnic nerves functions as a physiological modulator of catecholamine secretion by non-competitively suppressing ACh-induced cytosolic Ca(2+) dynamics in bovine a

The distribution of bovine immunodeficiency virus (BIV) in the organs of experimentally infected cows was investigated by use of nested polymerase chain reaction (PCR). Two cows (Nos. 1 and 2) experimentally infected with BIV were alive without any clinical symptoms of BIV infection for 28 months. Viral and proviral genomes of BIV were continuously detected from peripheral blood leukocytes in those cows by nested PCR. Proviral genome of BIV were also detected in liver, lung, and spleen cells in the two cows, and in the brain in cow No.1. Viral genomes were detected in liver, lung and spleen cells in cow No.1, and detected only in spleen cells in cow No.2. These results suggest that BIV tended to the persistent in some organs, especially in the spleen