Comparison between malignant and nonmalignant splenic masses in dogs using contrast-enhanced computed tomography.

The ability of computed tomography (CT) to distinguish malignant from nonmalignant splenic masses was evaluated in 21 dogs with 24 masses. CT scans of the abdomen were performed pre- and postintravenous contrast medium administration before splenectomy or euthanasia. Splenic masses were evaluated objectively based on Hounsfield units (HU) and volume.

Comparative data from 2250 male and female sports divers: diving patterns and decompression sickness.

Background: The aim of the study was to compare the diving habits and histories of men and women in recreational scuba diving.

Methods: More than 10,000 questionnaires were circulated to recreational divers in the United Kingdom. Retrospective, broad-based information was requested concerning general health, smoking, alcohol, recreational drug use, diving habits and histories, and physician-confirmed and self-diagnosed episodes of decompression sickness (DCS).

Kinetics of release of heparin from alginate hydrogel.

Purpose: Injected sodium alginate may be a useful perivascular drug delivery vehicle. This study was performed to determine the release rates of heparin from sodium alginate hydrogels cross-linked with varying amounts of calcium gluconate.

Materials And Methods: Six hydrogels, composed of 0.

Reactivity and Coaggregation of p-Nitrophenyl Esters with Polymer Micelles at Solid Surfaces.

The polymer micelle, poly[(N-(n-dodecyl)-4-vinylpyridiniumco-N-ethyl-4-vinylpyridinium) bromide], PDE, containing 30% dodecyl groups has been found to promote the adhesion of lipophiles to various surfaces including quartz, polystyrene, and poly(methyl methacrylate) cuvette surfaces from aqueous solutions. The adsorption of PDE/ester coaggregates to the surfaces was studied by hydrolysis of p-nitrophenyl esters in aqueous PDE(30) solutions. The extent of reaction of p-nitrophenyl myristate, an ester with a linear acyl carbon chain length of 14, can be viewed as a probe to study the adhesion of the PDE/ester coaggregates to the cuvette surfaces.

Mutations in the terminase genes of bacteriophage lambda that bypass the necessity for FI.

DNA maturation in bacteriophage lambda is the process by which the concatemeric precursor DNA is cleaved at sites called cos to generate mature lambda DNA molecules. These DNA molecules are then packaged into procapsids, the empty capsid precursors. The enzyme that catalyses these events is lambda DNA terminase.

Conformation of manganese(II)-nucleotide complexes bound to rabbit muscle creatine kinase: 13C NMR measurements using [2-13C]ATP and [2-13C]ADP.

Conformations of cation-nucleotide complexes bound to rabbit muscle creatine kinase were investigated by measuring paramagnetic effects on 13C spin relaxation in E.Mn[2-13C]ATP and E.Mn[2-13C]ADP at three different frequencies, viz.

Structural characterization and sequence distributions of polysiloxanes using pyrolysis MS/MS.

Novel polysiloxanes, with 4-(dialkylamino)pyridine substituents, are characterized by pyrolysis tandem mass spectrometry. These polymers form abundant cyclic oligomeric ions under both desorption electron ionization (DEI) and desorption chemical ionization (DCI) conditions. Product MS/MS spectra of the cyclic ions reveal characteristic fragmentations under low energy collision activated dissociation.

Structural characterization of poly(N-alkyl-4-vinylpyridinium) triflates using pyrolysis/tandem mass spectrometry.

Desorption chemical ionization (DCI) and desorption electron ionization (DEI) of homo- and co-polymers of N-alkyl-4-vinylpyridinium triflates having ethyl, n-hexyl and n-dodecyl groups as N-alkyl substituents, produce mass spectra that display oligomeric ions. These positively charged ions are singly-charged and result from cleavage of the polymer into neutral oligomers and the loss of a single triflate anion per oligomer. Analogous negatively charged ions, in which each neutral oligomer carries an extra triflate anion, are observed in the desorption chemical ionization mass spectra.

Slow reversible inhibition of rabbit muscle aldolase by D-erythrulose 1-phosphate.

Rabbit muscle aldolase was found to be inactivated in a slow, reversible manner by D-erythrulose 1-phosphate. This compound combined rapidly and reversibly with the enzyme to form an initial complex, which then only slowly (ki = 0.28 min-1) converted to a kinetically more stable form.

Synthesis of a trans-acting inhibitor of DNA maturation by prohead mutants of phage lambda.

Bacteriophage lambda with mutations in genes that control prohead assembly and other head precursors cannot mature their DNA. In this paper we present evidence that the failure of these phage mutants to mature DNA is a reflection of a mechanism that modulates terminase nicking activity during normal phage development. We have constructed plasmids that contain the lambda-cohesive end site (cos) and the genes that code for DNA terminase, the enzyme that matures DNA by cutting at cos.

Plasma volume and estimated liver plasma flow during hyperbaric and hyperoxic exposures in awake dogs.

Five different experiments were conducted to determine if estimated liver plasma flow and/or plasma volume were changed as a result of exposure to 2.8 atmospheres absolute (ATA) while breathing 100% oxygen or 6 ATA while breathing compressed air. The experiments were designed to separate the relative roles of the ambient pressure, the partial pressure of oxygen, the time of high oxygen exposure or some combination of these factors on any observed changes.

Hemodynamic effects of 10% dextrose and of dextran 70 on hemorrhagic shock during exposure to hyperbaric air and hyperbaric hyperoxia.

Six groups of six conditioned dogs each were instrumented with an electromagnetic flow-meter transducer around the pulmonary artery, and indwelling silastic cannulae in the pulmonary artery, the left ventricle, the ascending aorta, and the right atrium. After allowing a minimum of 5 d for recovery, the dogs were studied under normobaric conditions, breathing air, at 2.8 atmospheres absolute (ATA), breathing 100% oxygen (PO2 2128 mm Hg) and at 6 ATA breathing air (PO2 960 mm Hg).

The maturation of coliphage lambda DNA in the absence of its packaging.

In vivo, lambda DNA cannot be cleaved at cos (matured) if proheads are not present; in vitro, however, cos cleavage readily takes place in the absence of proheads. In order to investigate this paradox, we have constructed plasmids that synthesize lambda terminase in vivo upon induction. The plasmids also contain cos at the normal position, about 190 bp upstream of lambda gene Nul.

Pharmacokinetics of pentobarbital under hyperbaric and hyperbaric hyperoxic conditions in the dog.

High hydrostatic pressure has been shown to reverse the anesthetic effects of barbiturates. However, attempts to distinguish between two possible causes of this reversal, changes in drug disposition or changes in drug-receptor interaction, have not been reported. This study examined the possible effects of hyperbaria and hyperbaric hyperoxia on the distribution and clearance of pentobarbital in the dog.

Hemodynamic effects of lactated Ringer's solution on hemorrhagic shock during exposure to hyperbaric air and hyperbaric hyperoxia.

Three groups of six dogs each were instrumented with an electromagnetic flow-meter around the pulmonary artery, and indwelling silastic cannulas in the pulmonary artery, the left ventricle, the ascending aorta and the right atrium. After allowing 5-7 d for recovery the dogs were studied under normobaric conditions, breathing air, at 2.8 atmospheres absolute (ATA) breathing 100% oxygen (PO2 approximately equal to 2128 mm Hg) and at 6 ATA breathing air (PO2 approximately equal to 960 mm Hg).

Salicylate pharmacokinetics in the dog at 6 ATA in air and at 2.8 ATA in 100% oxygen.

Hyperbaric air and hyperbaric hyperoxia, which have been shown to decrease both liver plasma flow and plasma volume in dogs, may potentially affect the disposition of drugs whose distribution and/or elimination are dependent upon those actions. This study examined the effects of those conditions on the disposition of salicylic acid, using the dog as a model. The drug was administered to six mixed-breed dogs as a 10 mg sodium salicylate/kg i.

Drug disposition under hyperbaric and hyperbaric hyperoxic conditions: meperidine in the dog.

Patients being treated for a variety of conditions with hyperbaria or hyperbaric hyperoxia, and ill or injured deep sea divers being decompressed, may require concomitant drug therapy. This study examined the possible effects of those conditions on the distribution and elimination of meperidine, using the dog as a model. The drug was administered to six mixed-breed dogs as a 1.

Hemodynamic effects of Dextran 40 on hemorrhagic shock during hyperbaria and hyperbaric hyperoxia.

Three groups of six dogs each were instrumented with an electromagnetic flow-meter around the pulmonary artery, and indwelling silastic cannulas in the pulmonary artery, the left ventricle, the ascending aorta and the right atrium. After 7-10 d, dogs were studied under normobaric conditions, breathing air, at 2.8 atmospheres absolute (ATA) breathing 100% oxygen (PO2 approximately equal to 2128 mm Hg), and at 6 ATA breathing air (PO2 approximately equal to 960 mm Hg).

An evaluation of plasma volume expanders in the treatment of decompression sickness.

Each of 29 goats was instrumented with an ultrasonic flowmeter transducer around the left common carotid artery and a silastic catheter in the anterior vena cava. Following recovery from the surgery the goats were subjected to a dive protocol designed to elicit symptoms of decompression sickness (DCS). The goats were returned to the surface and, following a 20-min observation period, were either left untreated (controls) or treated with one of five different plasma volume expanders.