Immunofluorescence of bovine virus diarrhea viral antigen in white blood cells from experimentally infected immunocompetent calves

A study to evaluate the detection of bovine virus diarrhea viral antigen using immunofluorescence testing of white blood cells was conducted. Five colostrum-deprived calves were inoculated intravenously with a cytopathic strain of the virus. Lymphocyte and buffy coat smears were prepared daily for direct immunofluorescent staining for detection of antigen. Lymphocytes were separated from heparinized blood using a Ficoll density procedure. Buffy coat smears were prepared from centrifuged blood samples collected using ethylenediaminetetraacetic acid as an anticoagulant. Bovine viral diarrhea virus antigen was detected by immunofluorescence between 3 and 11 days postinfection in lymphocyte smears and 3 to 12 days postinfection in buffy coat smears. Isolation of virus from both lymphocytes and buffy coat preparations correlated with detection of immunofluorescence. Serum neutralizing antibody to bovine virus diarrhea virus was detected on day 10 postinfection. Buffy coat smears were as sensitive as lymphocyte smears for the detection of antigen by immunofluorescence. It appeared that immunofluorescent staining of white blood cells was an effective method of detecting bovine virus diarrhea viral antigen.

Alterations of NAD and adenylyl dinucleotide metabolism in Chediak-Higashi syndrome fibroblasts

Chediak-Higashi syndrome (CHS) cells have been previously observed to exhibit several of the same characteristics as those of xeroderma pigmentosum (XP) and xeroderma pigmentosum variants. Cultured CHS fibroblasts have been examined for altered responses in both depletion of NAD and elevation of diadenosine-5',5"'-tetraphosphate (Ap4A) following DNA damage since both responses have been reported as altered in XP cells and since Ap4A has been reported as absent from the platelets of CHS patients. Lowering of NAD following UV irradiation occurred in CHS cells in a manner similar to that of control and XP variant cells, but different from that of XP cells. CHS fibroblasts were not found to be deficient in Ap4A and exhibit basal levels very similar to those of control fibroblasts. No change in Ap4A pools were observed which correlated with cell growth, in contrast to previously published reports. Furthermore, while Ap4A levels are not elevated in XP cells, we observe an elevation of Ap4A pools in CHS cells which mimics the elevations observed in control and XP variant cells. We conclude that: (1) CHS cells more closely resemble control or XP variant cells than XP cells with regard to NAD lowering and Ap4A elevation following UV irradiation; (2) the photosensitivity exhibited by CHS cells is not due to general defects in the synthesis of poly(ADP-ribose) from NAD or in Ap4A metabolism; and (3) alteration of Ap4A pool size in CHS fibroblasts is inappropriate as a biochemical marker for CHS.

Inhibition of simian virus 40 DNA replication in vitro by poly(ADP-ribosyl)ated diadenosine tetraphosphate

Poly(ADP-ribosyl)ated diadenosine tetraphosphate was found to inhibit the in vitro replication of SV40 DNA. This inhibition was sensitive to preincubation of the polymer with either poly(ADP-ribose) glycohydrolase, diadenosine tetraphosphate (Ap4A):ADP phosphohydrolase, or an excess of free Ap4A. In contrast, the general catalytic activity of DNA polymerase was not inhibited by the poly(ADP-ribosyl)ated Ap4A when activated salmon sperm DNA was used as a template. These data suggest that inhibition of SV40 DNA replication by poly(ADP-ribosyl)ated Ap4A requires both the intact polymer and intact Ap4A moiety and is specific to events occurring during the initiation or elongation of a double-stranded template. Since both poly(ADP-ribose) and Ap4A accumulate in cultured mammalian cells following stresses which are accompanied by DNA strand breaks, these data are consistent with a model in which poly(ADP-ribosyl)ated Ap4A inhibits DNA replication following DNA damage.

Lead poisoning in cattle

Lead poisoning is a frequent cause of poisoning in domestic animals. Signs of encephalopathy and gastroenteritis are commonly observed in cattle following lead poisoning. This article discusses the etiology, epidemiology, pathogenesis, clinical signs, diagnosis, postmortem findings, and treatment of lead poisoning in cattle.

Detection and characterization of lipid hydroperoxides at picomole levels by high-performance liquid chromatography

A new method for the detection of various lipid hydroperoxides and hydrogen peroxide at the picomole level has been developed by combining an HPLC system with an ultrasensitive analytical system based on the detection of chemiluminescence emitted by isoluminol in the presence of hydroperoxide and microperoxidase. This HPLC separation removes interfering antioxidants so that the method can be applied to biological samples such as blood plasma lipids. Several HPLC conditions are described which allow simple identification of different lipid hydroperoxides.

Study on the etiologic role of bovine respiratory syncytial virus in pneumonia of dairy calves

Bovine respiratory syncytial virus (BRSV) was the viral agent most commonly identified in 14 epizootics of pneumonia in dairy calves. A microtiter serum-virus neutralization test proved to be the best means of identifying involvement of BRSV; seroconversion (fourfold or greater rise in titer) was demonstrated in 10 of the 14 epizootics. Only limited involvement of bovine viral diarrhea virus, infectious bovine rhinotracheitis virus, parainfluenza 3 virus, and bovine adenovirus type 3 was recognized. Pasteurella multocida was isolated in 12 of 14 epizootics, and Pasteurella haemolytica in 4 of 14 epizootics. Mycoplasmal and ureaplasmal agents were isolated in all 14 epizootics.

Alteration of adenyl dinucleotide metabolism by environmental stress

Exposure of cultured mammalian cells to a variety of conditions that induce the synthesis of stress proteins, including hyperthermia, ethanol, cadmium, and arsenite resulted in an increased cellular content of adenyl dinucleotides including diadenosine tetraphosphate (Ap4A). Exposure to other agents that cause metabolic perturbations not known to induce the synthesis of stress proteins, such as cyclohexamide, cytosine arabinoside, hydroxyurea, and ultraviolet irradiation did not alter the content of these nucleotides. It is proposed that these unique nucleotides may mediate adaptive responses of mammalian cells to environmental stress.

Seroepizootiologic study of bovine respiratory syncytial virus in a dairy herd

A 16-month seroepizootiologic study of bovine respiratory syncytial virus (BRSV) infection was conducted in a dairy herd. Results indicated that antibodies to BRSV present in serum from newborn calves were derived through the ingestion of colostrum. This passive immunity in calves became undetectable in an average of 99 days (SD = 36.5; range = 30 to 208 days). Two epizootics of respiratory tract disease occurred during the study period, and an association with BRSV was demonstrated in both epizootics. In the 2 epizootics, clinical signs of respiratory tract disease were only mildly to moderately severe, with no mortality or evidence of chronic pneumonia occurring. Seemingly, the passive immunity failed to protect calves from infection and disease caused by BRSV. Additionally, it was observed that if active immunity was induced by infection with BRSV, this immunity protected from the development of clinical disease, but not from reinfection upon subsequent exposures to BRSV.

Seroepizootiologic study of bovine respiratory syncytial virus in a beef herd

A seroepizootiologic study of bovine respiratory syncytial virus in a beef herd was conducted from February 1983 through March 1984. During the study period, 3 separate respiratory tract disease epizootics were recognized in calves after they had been split into 3 groups. Bovine respiratory syncytial virus infection was diagnosed in each epizootic on the basis of serologic evidence, postmortem findings, and immunofluorescent examination of lung tissue. Additionally, there was serologic evidence for involvement of bovine adenovirus type 3 in the epizootics in 2 of the groups of calves, but not in the 3rd. In 2 groups of calves, respiratory tract disease occurred in 2 stages, with the 1st stage being mild followed by apparent recovery. The 2nd stage, which was associated with a change to colder weather, was clinically more severe, with death loss occurring.

Bovine respiratory syncytial virus

The current knowledge is reviewed in regards to the importance of bovine respiratory syncytial virus in the bovine respiratory disease complex. The epidemiology, clinical disease, pathologic findings, pathogenesis, diagnosis, treatment, and prevention of this viral disease are discussed.

Serologic studies of bovine respiratory syncytial virus in Minnesota cattle

Serum antibody titers to bovine respiratory syncytial virus were determined for 559 cattle. Serum samples were obtained through the Minnesota State-Federal Brucellosis Laboratory and were collected over a 1-year period. Results of this study revealed an antibody prevalence of 65.5% to bovine respiratory syncytial virus. The distribution of antibody titers is presented, as well as analysis of titers based on breed, sex, and age of the cattle.

Vertebral fracture, extensor hypertonia of thoracic limbs, and paralysis of pelvic limbs (Schiff-Sherrington syndrome) in an Arabian foal

An Arabian foal, which was recumbent for 4 days, had signs of extensor rigidity of the thoracic limbs and hypotonic paralysis of the pelvic limbs. Survey radiography revealed a lesion at T15, with radiographic impression of a compression fracture or a hemivertebra. Postmortem examination revealed a fracture at T15. Clinical and pathologic findings in this case were compatible with the Schiff-Sherrington syndrome, which is characterized by thoracic limb extensor hypertonia associated with paraplegia from acute thoracolumbar trauma.

Determination of diadenosine 5',5''',-P1,P4-tetraphosphate levels in cultured mammalian cells

A simple method for measuring the cellular content of diadenosine 5',5'''-P1,P4-tetraphosphate (Ap4A) in cultured mammalian cells is described. Ap4A was rapidly extracted by dissolving cell monolayers using 0.1 N NaOH. It was separated from the bulk of cellular components in a single step by selective adsorption to a highly specific boronate affinity resin. Subpicomole amounts were quantified by a luciferin-luciferase bioluminescence assay performed in the presence of alkaline phosphatase and venom phosphodiesterase. The selectivity of this assay for Ap4A in cultured mouse cells was established by high-performance liquid chromatography. This method allows the routine measurement of subpicomole amounts of Ap4A derived from a single dish of cells.

Developmental biochemistry of cottonseed embryogenesis and germination : XVII. Developmental expression of genes for the principal storage proteins

The developmental time period and the magnitude of expression of the genes for the principal cottonseed storage proteins have been measured by several means. RNA was extracted from cotton cotyledons at stages during embryogenesis and the relative amounts of the mRNAS for these proteins were determined by cell-free translation in the wheat germ system and by dot and northern hybridization of the RNA with cloned cDNA probes representing the three subfamilies of the major storage protein genes. The rates of reassociation in solution of some of the RNAs with one of the cDNA clones were also determined. Data from all four procedures show that the storage protein mRNAs are demonstrable in very small embryo cotyledons, rapidly reach a high abundance level that is maintained during most of embryo growth, and then fall precipitously in amount in the last days of embryogenesis. The expression of all three gene subfamilies appears coordinate.Further, cDNA reverse transcribed from the poly(A)(+) mRNA from a stage of maximum storage protein synthesis was hybridized to saturation with cDNA clones representing each of the subfamilies. These data indicate that the mRNAs for two of the families reach the same relative level in the total mRNA population which is about 15% of the total mRNA mass. The mRNA of the third subfamily comprises only 5% of the total mRNA mass at this stage. This apparent 3∶3∶1 ratio of mRNAs does not change during the period of storage protein synthesis. Based on the amounts of the storage protein species in the mature seed, the mRNAs of each subfamily appear to be translated to the same extent during embryogenesis.

Expanded-beam connector design study

A theoretical analysis of an expanded-beam connector is presented, and it is shown that considerable scope exists for optimization of the design. A ray-tracing technique is used to quantify the importance of various parameters in determining the insertion loss. The design guidelines are presented in graphical form, and their usefulness is demonstrated in several examples of practical interest.

Excitation-contraction coupling in normal and myopathic hamster hearts III: functional deficiencies in interstitial glycoproteins

Extracellular and surface bound Ca is essential to excitation-contraction (E-C) coupling in mammalian cardiac muscle. In intact hearts from cardiomyopathic hamster with congestive heart failure, a concomitant decrease in the Ca content of a superficial pool was associated with the reduced contractility. Ca binding to cardiac sarcolemmal ghosts prepared from these hearts revealed two binding sites by Scatchard plot. In normal hamsters, the low affinity site had a capacity of 114 nmol Ca.mg-1 protein, a KD of 1.5 mmol . litre-1 and was sensitive to neuraminidase treatment but not to 100 mmol . litre-1 Na, K, or Li, Ca binding in vitro approached a 1:1 relationship with the sialic acid content of the ghosts, 159 nmol . mg-1 protein. The activity of the enzyme responsible for glycosidically linking sialic acid to interstitial and sarcolemmal glycoproteins, sialyltransferase, was reduced from 1.80 to 0.41 pmol . mg-1 protein in the myopathic hearts. We suggest the functional defect in the hamster cardiomyopathy is a reduction in sialyltransferase activity leading to the deficiency in surface sialic acid residues. As a consequence, contractility is reduced, but Ca influx is increased. Reflex sympathetic activity increases Ca influx resulting in "Ca overload" and eventual cellular necrosis.

Cytochrome P-450 and hepatic drug biotransformation during progressive cardiac disease in cardiomyopathic hamsters

Reductions in cytochrome P-450 levels and aminopyrine N-demethylase activity of hepatic microsomes obtained from cardiomyopathic hamsters (BIO 14.6) occurred at all stages of the disease before the development of congestive heart failure (CHF). Cytochrome b5 levels were reduced only in animals with CHF when compared with age-matched controls (BIO.RB). Total microsomal protein and p-nitrophenol glucuronidation were not affected by the disease process. We conclude that the reduction in cytochrome P-450 levels and N-demethylase activity in cardiomyopathic hamsters is not a consequence of CHF, but is one of the manifestations of the disease process.

Self-control training for inmates

This paper describes a structured group training program which teaches prison inmates behavior modification techniques of relaxation, desensitization, self-image improvement, correct assertiveness, etc. to help them gain greater control over their own lives.

Biological disposition of rigid analogs of amphetamine

Tissue levels of amphetamine and of amphetamine analogs with a rigid conformation (2-aminoindan, 2-aminotetralin, and 2-aminobenzocycloheptene) were measured in rats by a spectrofluorometric method involving the reaction of the primary amine group with fluorescamine. All drugs were concentrated in tissues, the order of distribution being lungs greater than kidneys greater than liver=spleen=brain greater than muscle greater than fat=heart greater than blood. In brain, amphetamine and 2-aminoindan were present mostly in the supernatant fraction after high speed centrifugation onbrain homogenates; the two higher molecular weight drugs were present at slightly greater concentrations in the particulate fraction. All four drugs disappeared from rat brain with half-lives of 1-2 hr. Iprindole pretreatment increased drug levels in brain and prolonged the half-lives by two- to threefold. The data suggest that the biological disposition of the rigid analogs resembles generally that of amphetamine and that all of the drugs are probably metabolized by ring hydroxilation in the rat.

Biochemical pharmacology of some chlorinated 3-phenyl-piperidines in rats

Chlorinated 3-phenyl-piperidines were administered to rats with the expectation--based on structural similarities--that they might resemble chlorinated amphetamines pharmacologically. The 3-chloro, 4-chloro, and 3,4-dichloro compounds all lowered serotonin and 5-hydroxyindoleacetic acid levels in rat brain, whereas the 2-chloro compound had no effect. The brain levels and half-lives of the four compounds suggested that the compounds might be metabolized by hydroxylation at the 4- position of the phenyl ring. Desmethylimipramine, an inhibitor of amphetamine hydroxylation in the 4- position, markedly elevated brain levels of the 2-chloro compound and to a lesser extent of the 3-chloro compound. The 2-chloro compound did not lower brain serotonin levels even in desmethylimipramine-treated rats, however. The results suggest that some pharmacologic properties of the chlorinated 3-phenyl-piperidines are indeed similar to those of chlorinated amphetamines.