Reduced incidence of retained placenta with induction of parturition in the cow

Two experiments were designed to determine whether pretreatment with Opticortenol (OPT), a long-acting corticosteroid, prior to induction of parturition with 25 mg of dexamethasone (DEX) alone or in combination with 500 mug cloprostenol (CLO) would result in a reduced incidence of retained placenta. In Experiment 1, 70% of the cows pretreated with 25 mg OPT on Day 270 of gestation calved before or within 24 hours of the scheduled induction treatment on Day 277. Cows induced to calve with DEX plus CLO without OPT pretreatment had an increased rate of placental retention (P<0.05), whereas, cows that received OPT were not different from the controls. In Experiment 2, cows received either 1 mg/25 kg OPT (high dosage) or 1 mg/50 kg OPT (low dosage) on Day 270 of gestation and were induced with DEX plus CLO on either Day 274 (4 days) or Day 276 (6 days). Cows claved 29.0 to 31.8 hours after induction treatment with 95% beginning to calve between 0700 and 1900 hours. The interval from calving to placental release and the incidence of retained placenta was not different between the high dosage 6-day group (29.4+/-8.2 hours, 29%) and the non-induced control cows (16.1+/-10.7 hours, 5%). When three cows in the high dosage 6-day group that retained their placentas for 30 to 36 hours were considered as not retained, the incidence of placental retention for that group was reduced still further to 17%. First service conception rates and pregnancy rates were lower in cows with retained placentas. Differences were significant (P<0.01) in Experiment 1 but not in Experiment 2. It was concluded that pretreatment with 1 mg/25 kg OPT 6 days prior to induction of parturition with DEX plus CLO in combination results in a predictable calving time, high calf viability, and a low incidence of placental retention.     

Isolation of a neuraminidase gene from Actinomyces viscosus T14V.

A genomic library of Actinomyces viscosus T14V DNA in lambda gt11 was screened for expression of neuraminidase activities. Four recombinant clones were detected that gave blue fluorescence upon incubation with a fluorogenic substrate, 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid. Of these, two were identical, and all of the neuraminidase-positive clones shared a common 3.4-kbp DNA region. Expression of the enzyme activities in Escherichia coli carrying the cloned DNA was independent of the lacZ promoter of the vector. Maxicell analysis revealed that the 3.4-kbp DNA insert directed synthesis of a protein with an apparent molecular mass of 100,000 Da. The protein from cell extracts of E. coli clones migrated as a single band that stained for enzyme activity after electrophoresis in a nondissociating polyacrylamide gel. Moreover, human erythrocytes incubated previously with cell lysates from neuraminidase-positive E. coli were hemagglutinated by Actinomyces spp. The enzyme expressed by E. coli was active on substrates containing alpha-2,3 and alpha-2,6 ketosidic linked sialyl residues. Similar substrate specificities were obtained for both the extracellular and cell-associated neuraminidases from A. viscosus T14V. The 3.4-kbp insert hybridized to DNA fragments in a Southern blot containing A. viscosus T14V chromosomal DNA that had been digested with various restriction endonucleases. Data from hybridization studies show that A. viscosus T14V contains a single copy of the neuraminidase gene.     

Papain kinetics in the presence of a water-miscible organic solvent

The effects of various concentrations of a water-miscible organic solvent [a 7:3 (v/v) mixture of N, N dimethylformamide and dimethylsulfoxide] on the kinetics of papain have been investigated. The parameters k(cat) and K(m) for the amidase and esterase activity of papain using N-alpha-benzoyl-DL-arginine-p-nitroanilide (BAPNA) and N-alpha-benzoyl-L-arginine ethyl ester (BAEE) as substrates were determined. For both types of activity, k(cat) initially increased (up to about 15% solvent), and then decreased with increasing concentrations of organic solvent. In contrast, K(m) increased sharply with the organic solvent concentration. Active site titration at 0 and 50% solvent indicated no change in the amount of active enzyme. Fluorometric measurements of the emission spectrum of papain did not indicate any major conformational changes with increasing concentrations of organic solvent.     

Effect of chronic alcohol consumption on rat uterine spontaneous motility, prostaglandin production and triglyceride metabolism

The spontaneous isometric developed tension (IDT), the synthesis and release of prostaglandins (PGs) into the incubating medium and the metabolism of triglycerides (TGs) in uterine strips isolated from controls and chronic ethanol fed rats, were studied. In order to observe how the uterus of rats fed alcohol reacts during a situation of metabolic emergency, the above mentioned studies were done in the presence or in the absence of glucose in the incubating medium. The decrement of IDT as time progressed was significantly greater in strips obtained from rats which had been drinking 20% ETOH than in controls. Nevertheless, the absolute magnitude of the initial IDT was similar in both groups. On the other hand, the decline of the frequency of contractions (FC) of uterine strips isolated from controls and from ETOH-exposed rats, after 60 min of spontaneous activity was similar. When the uterine strips isolated from ETOH-exposed and from control rats were suspended in glucose-free solution they exhibited the same decrement of IDT and FC after 60 min of activity. The basal release of PGE1 and PGE2 was similar in control tissues incubated in medium containing glucose, but the output of PGE2 was significantly smaller than that of PGE1 in uterine strips isolated from ETOH-exposed rats. The production of PGE1 and PGE2 by uteri suspended in glucose-free medium was similar in control preparations. On the contrary the release of both PGs differs in uterine strips from ETOH-exposed rats, i.e. the output of PGE2 was significantly smaller than in controls and the release of PGE1 increased around 4-fold in comparison with controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Role of tissue hypoxia as the mechanism of lactic acidosis during E. coli endotoxemia.

We compared the hemodynamic and metabolic alterations produced in rabbits by similar decreases in cardiac output created by inflating a balloon placed in the right ventricle (n = 6) with those produced by an intravenous bolus of Escherichia coli lipopolysaccharide (LPS; SEP group; n = 6). We measured O2 consumption (VO2), O2 transport (TO2), and O2 extraction ratio (ERO2) for the whole animal and also for the left hindlimb. Both groups experienced similar decreases in cardiac output, systemic TO2, and VO2 and similar increases in ERO2. For the hindlimb, TO2 was similar, but VO2 and ERO2 were lower for the SEP group 30 min after LPS administration (P less than 0.05); however, this difference disappeared during the remainder of the experiment. Arterial lactate concentration was greater (P less than 0.05) for the SEP group. There were no differences in skeletal muscle PO2, measured with a multiwire surface electrode, or in cardiac and skeletal muscle concentrations of high-energy phosphates. We hypothesize that a direct effect of LPS on cellular metabolism may have resulted in greater arterial lactate concentration for the SEP group.     

Monoclonal antibodies to rabbit liver cytochrome P-448

Cytochrome P-448 (mol wt 55,000 Daltons) from rabbit liver was purified to a specific content of 16.6 nmol/mg. Mice were immunised with this preparation, their spleens removed and dissociated lymphocytes hybridised with myeloma cells. Four monoclonal antibodies against cytochrome P-448 were raised and partially characterised. All four antibodies interacted with cytochrome P-448 in intact microsomal fractions and selectively immunoadsorbed cytochrome P-448 from solubilised microsomal preparations. One of the antibodies inhibited benzo[a] pyrene hydroxylase activity in a reconstituted system, one had no effect on activity and two increased activity. The possible applications of such antibodies are discussed.     

Hypertrophic cardiomyopathy associated with left ventricular aneurysm and normal coronary arteries: Case study indicating genetic tendencies of cardiomyopathy

A 50-year-old man presented with hypertrophic obstructive cardiomyopathy (HOC) associated with a left ventricular aneurysm and normal coronary arteries. His history revealed no evidence of myocardial infarction or atypical angina. Physical examination disclosed HOC but did not suggest the presence of an aneurysm. Although the patient was treated medically, heart failure ensued, and he died suddenly while working his farm. Subsequent investigation of the patient's family revealed that three of his five children were also affected by cardiomyopathy, which was especially pronounced in the eldest, a 22-year-old man. The possible hemodynamic relationship between HOC and left ventricular aneurysm is discussed, along with probable indications. The role of left ventricular aneurysm is also presented in relation to the natural history of the disease.     

Particle selection in the nauplius of Calanus pacificus

Food selection by the nauplius of Calanus pacificus is definedas the ability to ingest certain kinds of particles in behavioralpreference to others that occur simultaneously in the same environment.Using mixtures of planktonic algae and plastic beads of differentor similar sizes, the nauplii strongly selected the algal cells,consuming them almost exclusively, and at similar rates to thecontrols with only algae. In some cases, however, ingestionrates on the algae were lower than the in the controls, mainlywhen the mixture was composed of algal cells and plastic beadsof smaller sizes able to be captured by the nauplii. Selectionof algal particles was also observed when pollen grains or detrituswere used instead of the plastic beads. Selection behavior alsooccurred when mixtures of two algae of different sizes wereoffered to the nauplii, and it was dependent on the proportionand concentration of both kinds of algae in the mixture. Thepossible effect of particle production on the observed selectivepatterns is discussed.