Evidence suggesting the regulation of a coagulation factor levels in rabbits by a transferable plasma agent.
New Zealand white rabbits were given 30 ml of goat serum intravenously. This procedure resulted in an immediate decrease in platelet count, fibrinogen, and levels of coagulation factors II, V, VII, and X, due to consumption coagulopathy. These factors returned toward baseline levels approximately 12 hr after the injection. Plasma from rabbits who had received goat serum 48 hr previously (donor rabbits) was injected into recipient rabbits. This procedure resulted in a slight rise in the level of coagulation factor II (range, 20%-30%) and a significant rise in factors V (35%-75%), VII (35%-235%), and X (35%-75%) in the recipients. When plasma from control donor rabbits who had not received goat serum was injected into recipients, there was no change in these coagulation factors. It is postulated that the reduction in coagulation factor levels in donor rabbits induces a "coagulopoietin" for each factor or one "coagulopoietin" for all factors which stimulates increased synthesis and/or release of these factors in recipient rabbits. (+info)
The role of colorstrum on the occurrence of immunoglobulin G subclasses and antibody production in neonatal goats.
Quantitative determinations of IgG1 and IgG2, in one group of colostrum-fed and one group of colostrum-deprived neonatal goats revealed that the occurrence of the IgG1 subclass preceeded that of the IgG2 in both cases. In the colostrum-fed animals the IgG2 appeared, on an average, in the fourth week of life whereas in the colostrum-deprived animals the IgG2 was detected as early as three weeks after birth. At the age of twelve weeks the mean concentrations for IgG, and IgG2 were higher in the animals deprived of colostrum. The immune response to human gamma globulin was studied in colostrum-fed and colostrum-deprived neonatal goats which were immunized at birth and again after four and eight weeks. Following the first two antigen administrations a significantly higher response was obtained in the colostrum-fed neonates. However, the third injection determined a similar response in both groups. A marked suppressive effect on the immune response was observed in colostrum-fed neonatal goats when specific antibodies were present in the colostrum after preimmunization of the mothers with human gamma globulin. (+info)
A novel epitope for the specific detection of exogenous prion proteins in transgenic mice and transfected murine cell lines.
Prion diseases are closely linked to the conversion of host-encoded cellular prion protein (PrPC) into its pathological isoform (PrPSc). PrP conversion experiments in scrapie infected tissue culture cells, transgenic mice, and cell-free systems usually require unique epitopes and corresponding monoclonal antibodies (MAbs) for the immunological discrimination of exogenously introduced and endogenous PrP compounds (e.g., MAb 3F4, which is directed to an epitope on hamster and human but not on murine PrP). In the current work, we characterize a novel MAb designated L42 that reacts to PrP of a variety of species, including cattle, sheep, goat, dog, human, cat, mink, rabbit, and guinea pig, but does not bind to mouse, hamster, and rat PrP. Therefore, MAb L42 may allow future in vitro conversion and transgenic studies on PrPs of the former species. The MAb L42 epitope on PrPC includes a tyrosine residue at position 144, whereas mouse, rat, and hamster PrPs incorporate tryptophane at this site. To verify this observation, we generated PrP expression vectors coding for authentic or mutated murine PrPCs (i.e., codon 144 encoding tyrosine instead of tryptophan). After transfection into neuroblastoma cells, MAb L42 did not react with immunoblotted wild-type murine PrPC, whereas L42 epitope-tagged murine PrPC was strongly recognized. Immunoblot and fluorescence-activated cell sorting data revealed that tagged PrPC was correctly posttranslationally processed and translocated to the cell surface. (+info)
Cloning and sequencing of beta-mannosidase gene from Aspergillus aculeatus no. F-50.
The manB gene, coding for a unique beta-mannosidase (MANB) of Aspergillus aculeatus, was cloned from genomic and cDNA libraries, and sequenced. The gene consists of 2,811 bp encoding a polypeptide of 937 amino acid residues with a molecular mass of 104,214 Da. The A. aculeatus MANB shared amino acid sequence identity with MANB of human (24%), goat (24%), bovine (24%), and Caenorhabditis elegans (22%). When the A. aculeatus MANB was compared with other related enzymes, a Glu residue corresponding to the active site identified by the Escherichia coli beta-galactosidase and the human beta-guclonidase was conserved. This is the first fungal gene that encodes MANB. (+info)
The effect of bovine somatotropin treatment on production of lactating angora does with kids.
Fourteen Angora does (35+/-2 kg), each with a single kid and in the first month of lactation, were used to determine ongoing (Period 1) and residual (Period 2) effects of chronic bovine somatotropin (bST) treatment. Specifically, we sought to determine whether chronic bST treatment was capable of improving milk yield, and thus kid growth, and mohair production of nursing does. The experiment consisted of a 2-wk pretreatment period, 5 wk of weekly subcutaneous treatment of slow-release bST (n = 7; Period 1), and a 4-wk posttreatment period (Period 2). The weekly dose of bST was calculated to release 100 microg/(kg BW.d(-1)). To estimate milk production, kids were separated from the does daily for 5 h, and their BW was recorded before and after suckling. The difference in BW was taken as milk production for 5 h. Fiber growth was measured by shearing does at the start of the experiment and at the end of Periods 1 and 2. Dry matter intake and BW of does were not affected by bST (P>.05). Average daily gain of kids that were suckling bST-treated does was higher (P<.05) than for kids of untreated does during Period 1 (184 vs. 139 g/d) but not during Period 2 (140 vs. 136 g/d; P>.10). Treatment with bST did not affect (P>.10) milk composition or clean fleece production in either period. Injection of bST did not affect (P>.10) plasma concentrations of glucose (mean = 49.5 mg/dL), urea N (mean = 19 mg/dL), total protein (mean = 72.5 g/d), or NEFA (mean = 122 microEq/L). During the period of bST treatment, plasma concentrations of somatotropin and IGF-I were increased (P<.05), concentrations of thyroxine and cortisol were decreased (P<.10), and plasma insulin levels were unchanged (P>.10) by bST. In conclusion, treatment of Angora dams with bST did not change DMI or mohair growth, but it improved growth of their kids. (+info)
Mechanical maceration of alfalfa.
Maceration is an intensive forage-conditioning process that can increase field drying rates by as much as 300%. Because maceration shreds the forage and reduces its rigidity, improvements in bulk density, silage compaction, and ensiling characteristics have been observed. Macerating forage also increases the surface area available for microbial attachment in the rumen, thereby increasing forage digestibility and animal performance. Feeding trials with sheep have shown increases in DMI of 5 to 31% and increases in DM digestibility of from 14 to 16 percentage units. Lactation studies have demonstrated increases in milk production and BW gain for lactating Holstein cows; however, there is a consistent decrease in milk fat percentage when dairy cattle are fed macerated forage. In vitro studies have shown that maceration decreases lag time associated with NDF digestion and increases rate of NDF digestion. In situ digestibility studies have shown that maceration increases the size of the instantly soluble DM pool and decreases lag time associated with NDF digestion, but it may not consistently alter the rate or extent of DM and NDF digestion. (+info)
Experimentally induced bovine spongiform encephalopathy did not transmit via goat embryos.
Goats are susceptible to experimental challenge with bovine spongiform encephalopathy (BSE). This study set out to investigate whether the transmission of BSE could occur in goats following the transfer of embryos from experimentally infected donor females into uninfected recipient females. The results showed no evidence of transmissible spongiform encephalopathy disease in any of the offspring which developed from embryos from infected donors, nor indeed in any of the recipient females used as surrogate dams. In addition, there was no indication of experimental BSE spreading as either a venereal infection to males used in mating or by maternal transmission to offspring born naturally to experimentally infected donors, although numbers were small. (+info)
Serotyping of Cryptococcus neoformans isolates from clinical and environmental sources in Spain.
We determined biovars and serotypes of 154 isolates of Cryptococcus neoformans from clinical and environmental sources from different areas of Spain. All clinical isolates belonged to C. neoformans var. neoformans. Serotypes showed an irregular distribution. C. neoformans var. gattii serotype B was isolated from necropsy specimens from goats with pulmonary disease. (+info)