Action of long(R)-insulin-like growth factor-1 on protein metabolism in beef heifers

Insulin-like growth factor-1 (IGF-1) is perhaps the most important endogenous factor controlling growth. Most studies to date in livestock have shown that IGF-1 has greatest efficacy when animals are in a catabolic state. We have determined the effects of an iv infusion of the IGF-1 analog Long(R³)-IGF-1 on protein metabolism in beef heifers that were slowly losing liveweight because of restricted feeding. There was a tendency for both whole-body protein and skeletal muscle protein to be conserved in Long(R³)-IGF-1-treated heifers. Long(R³)-IGF-1 administration markedly reduced the plasma concentrations of all amino acids measured and glucose. There was a significant change in the profile differences of endogenous plasma IGF-1 concentrations during the 8-hr infusion period, with plasma IGF-1 decreasing sharply in the test group. There was a significant difference in mean profiles for plasma IGF-2 between the test and control groups. Overall, plasma IGF-2 for the control group decreased only slightly over time (about 40 ng/ml), whereas the test group decreased dramatically (by about 140 ng/ml). Increased plasma concentrations of a 31–32-kDa IGF-binding protein (possibly IGF-binding protein-1) in the treated group was detected by radioligand blot. We found that Long(R³)-IGF-1 infusion tended to preserve whole-body and muscle protein in beef heifers on a low-quality diet, and suggest that further investigation of this treatment may provide an alternative approach to reducing weight loss during the dry season.     

Acute and persistent alterations in pulmonary inflammatory cells and airway mast cells induced by Sendai virus infection in neonatal rats

Neonatal rats inoculated with parainfluenza type 1 (Sendai) virus develop alveolar dysplasia and bronchiolar hypoplasia by 30 to 110 days after inoculation. Weanling rats do not develop these abnormalities. Because neonatal animals have hyporesponsive immune and inflammatory cell functions, and because neonatal rats support pulmonary viral replication for longer duration and are delayed in their viral antibody response compared to weanling rats, we compared inflammatory and immune responses of two age groups of rats following viral inoculation. Data from quantitative bronchoalveolar lavage 1 to 29 days following viral inoculation demonstrated that neonates had significantly fewer (P less than 0.05) lymphocytes and macrophages in their bronchoalveolar fluid per cm2 alveolar surface than weanlings. Magnitude of neutrophil responses in neonatal rats compared to weanlings were not depressed. Pulmonary interferon activity was lower in neonates than in weanlings at 2, 3, 4, and 5 days after viral inoculation. Neonates failed to make antibody following intraperitoneal inoculation of inactivated viral antigen, whereas weanling rats had detectable viral antibody by 3 to 5 days after injection of antigen. At 90 days after inoculation of neonates, viral-inoculated rats had over 100-fold greater numbers (P less than 0.05) of mast cells in enzyme-dissociated lung preparations compared to age-matched controls. Viral-inoculated rats had two- to three-fold greater densities of mast cells (#/mm) in bronchiolar walls (P less than 0.02) than did control rats.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transmission of visceral leishmaniasis through blood transfusions from infected English foxhounds to anemic dogs.

OBJECTIVE: To conduct serologic surveillance for Leishmania spp in English foxhounds from a kennel, as well as recipients of blood from these dogs, and determine whether L infantum organisms could be transmitted via blood transfusion. DESIGN: Serologic prevalence survey. ANIMALS: 120 English foxhounds and 51 dogs of various breeds receiving blood from these donors. PROCEDURE: Foxhound blood donors, foxhound nondonors, and nonfoxhound blood recipient dogs were evaluated serologically for Leishmania spp by indirect fluorescent antibody testing. Dogs that received packed RBC (PRBC) transfusions from foxhound donors from mid-1996 through mid-2000 were identified. Furthermore, dogs were serologically evaluated if they had received fresh frozen plasma (FFP) transfusions in 1999 and 2000 from seropositive foxhound blood donors. RESULTS: Thirty percent of the English Foxhounds were seropositive for Leishmania spp (titer > or = 1:16), although the degree of seropositivity varied considerably during the period. Furthermore, 57 foxhounds had been used as donors from 1996 to 2000, and 342 units of PRBC had been transfused to at least 227 patients. All 25 dogs screened that received PRBC from seronegative foxhound donors tested negative, whereas 3 of 7 dogs that received PRBC from seropositive donors tested positive. All 9 dogs that received FFP from seropositive foxhound donors remained seronegative. CONCLUSIONS AND CLINICAL RELEVANCE: To our knowledge, this report documents the first transmission of Leishmania spp by blood transfusion. The use of foxhounds as blood donors may not be advisable in North America.     

Clinical usefulness of intradermal fluorescein and patent blue violet dyes for sentinel lymph node identification in dogs

The first lymph node receiving drainage from a specific anatomic region is referred to as the sentinel lymph node (SLN). This study sought to evaluate the intradermal use of two dyes, patent blue violet (PBV) and fluorescein (FL), for SLN mapping in the dog. Multiple intradermal injections were performed in five healthy dogs using two dyes, PBV in 0.9% NaCl and FL in solutions of 0.9% NaCl and 6% hetastarch. Skin flaps were raised and followed to the first area of discrete stain uptake. Areas of uptake were identified as lymph nodes grossly and by cytology. Identification of a SLN for each area of intradermal injection was accomplished for 98% of the injection sites. Intradermal injections of both PBV and FL dyes produce readily visible staining of lymphatic vessels and SLNs in healthy dogs and are sufficient to allow ready identification of these structures during postmortem dissection.     

Protection of cattle against rinderpest with vaccinia virus recombinants expressing the HA or F gene

Rinderpest is a highly contagious ruminant viral disease manifested by a rapid course and greater than 90% mortality. Infectious vaccinia virus recombinants were constructed that express either the hemagglutinin or the fusion gene of rinderpest virus. All cattle vaccinated with either recombinant or with the combined recombinants produced neutralizing antibodies against rinderpest virus and were protected against the disease when challenged with more than 1000 times the lethal dose of the virus.     

The density of inflows to Onondaga Lake,U.S.A., 1980 and 1981

The temporal distributions of the densities of inflows to Onondaga Lake were calculated for the spring to fall period of 1980 and 1981, and compared to the attendant density stratification in ion enriched Onondaga Lake. The industrial utilization of the lake resulted in substantial density differences between the inflows and the lake. Inflows carrying substantial fractions of industrial ionic waste were more dense than the lake, and at times plunged to stratified layers. Water withdrawn from the lower layers of the lake for industrial cooling was displaced to the upper layers as a result of heating. Dilute fluvial inflows were substantially less dense than the lake. The density differences between the inflows and the lake were largely responsible for the rather unique features of density stratification documented for the lake in 1980, and are probably of further importance in nutrient loading to, and cycling in, Onondaga Lake.     

Nature of the transient activation of soil microorganisms by ethanol or acetaldehyde

Low molecular weight alcohols and aldehydes emanating from undecomposed plant residues cause a rapid activation of microbial respiration and growth in soil. To determine the relative utilization of added volatile or endogenous microbial reserves during a transient period of activation, ethanol-1,2-¹⁴C or acetaldehyde was added to soil. With concentrations of ethanol giving near maximal respiration, 80–90 per cent of the CO₂ evolved in excess of the control came from labelled ethanol. For comparison, similar experiments were performed with spores of Fusarium solani under conditions where ethanol was a required substrate for germination. About 70–90 per cent of the CO₂ evolved in excess of the control came from added ethanol. In both the soil and spore systems enhanced respiration continued for less than 5 hr and ceased when the volatile substrate was depleted. Few endogenous reserves were utilized, and substantial amounts of cellular materials apparently were accumulated during this process. No changes in numbers of soil microorganisms were observed either during the transient activation or during the subsequent 2 weeks.