Venous carbon dioxide embolism in pigs: an evaluation of end-tidal carbon dioxide, transesophageal echocardiography, pulmonary artery pressure, and precordial auscultation as monitoring modalities.

We evaluated the effects of CO2 embolism on end-tidal carbon dioxide (ETCO2) and compared four methods for detection of gas embolism. Fourteen pigs were monitored for CO2 embolism with transesophageal echocardiography (TEE), changes in ETCO2, changes in mean pulmonary artery pressure (MPAP), and precordial auscultation (AUSC). Serial injections of CO2 (ranging from 0.

Structure-activity study of neuropeptide FF: contribution of N-terminal regions to affinity and activity.

Twenty neuropeptide FF (NPFF) analogs having various lengths were synthesized by solid-phase peptide synthesis to gain more information on the role of N-terminal residues for the NPFF receptor affinity. The affinities were evaluated in the rat spinal cord membrane preparations, and the biological activities were measured on morphine analgesia in the mouse tail-flick test. Shortening of the NPFF sequence from the N-terminal produced only a moderate decrease in affinity until NPFF (4-8) was reached.

Molecular systematics of hystricognath rodents: evidence from the mitochondrial 12S rRNA gene.

Nucleotide sequence variation among 22 representatives of 14 families of hystricognathid rodents was examined using an 814-bp region of the mitochondrial 12S ribosomal RNA (rRNA) gene composing domains I-III. The purpose of this study was twofold. First, the phylogenetic relationships among Old World phiomorph (primarily African) and New World caviomorph (primarily South American) families were investigated, with a special emphasis on testing hypotheses pertaining to the origin of New World families and the identification of major monophyletic groups.

Contribution of oxidative metabolism and glycolysis to ATP production in hypertrophied hearts.

The contribution of glycolysis and oxidative metabolism to ATP production was determined in isolated working hypertrophied hearts perfused with Krebs-Henseleit buffer containing 3% albumin, 0.4 mM palmitate, 0.5 mM lactate, and 11 mM glucose.

Preischemic glycogen reduction or glycolytic inhibition improves postischemic recovery of hypertrophied rat hearts.

The purpose of this study was to determine whether metabolites produced by glycolysis during ischemia significantly contribute to myocardial injury of hypertrophied hearts. The accumulation of glycolytic metabolites during ischemia was reduced by means of glycogen reduction or by treatment with the glycolytic inhibitor, 2-deoxy-D-glucose (2-DG) before ischemia. Hearts from aortic-banded (Band) and sham-operated (Sham) rats (8 wk postop) were isolated, perfused with Krebs buffer, and had a left ventricular (LV) balloon to measure developed pressure.

Characterization of a potent agonist for NPFF receptors: binding study on rat spinal cord membranes.

Specific receptors for the octapeptide FLFQPQRFamide (NPFF), a mammalian FMRFamide-like neuropeptide with anti-opiate properties have been identified in rat central nervous system. However, exploration of the biological role of this peptide requires a peptidase-resistant agonist. In this study, the stability and binding characteristics of [125I]DYLMeFQPQRFamide, a radioiodinated analogue of NPFF, on rat spinal cord tissue were determined and compared with those of [125I]YLFQPQRFamide, the reference ligand which previously permitted to characterize NPFF binding sites.

Autoradiographic localization of receptors for neuropeptide FF, FLFQPQRFamide, in human spinal sensory system.

The regional distribution of FLFQPQRFamide binding sites on fresh unfixed cryostate sections from post mortem specimens of human spinal cord and lower medulla oblongata was studied by quantitative autoradiographic methods using [125I]YLFQPQRFamide as ligand. Samples were taken from five cases who had died with no history of neurological disease at ages ranging from 5 months to 66 years. The biochemical and pharmacological characteristics of [125I]YLFQPQRFamide binding to mounted tissue sections were comparable to those reported for the rat in a previous study.

Rapid Identification of Rhizobia by Restriction Fragment Length Polymorphism Analysis of PCR-Amplified 16S rRNA Genes.

Forty-eight strains representing the eight recognized Rhizobium species, two new Phaseolus bean Rhizobium genomic species, Bradyrhizobium spp., Agrobacterium spp., and unclassified rhizobia from various host plants were examined by restriction fragment length polymorphism (RFLP) analysis of 16S rRNA genes amplified by polymerase chain reaction (PCR).

Cromakalim and cicletanine against pacing-induced myocardial ischemia in conscious rabbits.

Myocardial ischemia assessed by intracavital ST-segment elevation, shortening of ventricular effective refractory period (VERP), and increase in left ventricular end-diastolic pressure (LVEDP) was provoked by ventricular overdrive pacing (VOP) in conscious rabbits. Cromakalim (10 micrograms/kg), an ATP-sensitive K+ channel opener, and cicletanine (30 mg/kg), a cGMP-phosphodiesterase inhibitor, reduced VOP-induced ST-segment elevation and LVEDP-increase. Under resting conditions, cromakalim lowered blood pressure, increased heart rate (HR), and shortened VERP, whereas cicletanine decreased HR, prolonged VERP without changing blood pressure.

Opposite effects of cell growth factors and cicletanine sulfate on the sodium-independent [Cl-/HCO3-] exchange in cultured vascular smooth muscle.

Cicletanine sulfate was tested on bicarbonate-dependent pHi changes in cultured vascular smooth muscle (A10 line). Cicletanine sulfate exhibited double reactivity with regard to the cell alkalinization induced by bicarbonate uptake. The analysis of 11 concentration-response curves revealed a high reactivity component (IC50 approximately 3.

Evaluation of the true effect of experimental parameters on the reduction / oxidation processes observed in fast-atom bombardment/liquid secondary spectrometry.

The peak intensities observed in the molecular ion regions of fast-atom bombardment/liquid secondary ion mass spectra contain contributions from the parent ion species, its one- and two-electron reduction/oxidation products, and chemical background signal due to beaminduced damage. There are several solution and instrumental parameters that can affect the distribution of peak intensities in the molecular ion region. In this study, the analyte concentration and primary beam density and energy were varied systematically to investigate their effects on the measured peak intensities.

Characterization of a morphine-modulating peptide, FLFQPQRFamide, in the rat hypophysis: biochemical and immunocytochemical studies.

The octapeptide FLFQPQRFamide (F8Fa) is a FMRFamide-like peptide with a certain number of antiopiate properties. Previous studies have shown that both F8Fa specific receptors and F8Fa-like material are present in the rat central nervous system. In this study, RIA revealed that the rat neurohypophysis also contains F8Fa immunoreactive (IR) material (230 +/- 49 pg/neural lobe).

Regional myocardial capillary erythrocyte transit time in the normal resting heart.

A major determinant of oxygen transport to the myocardium is the time spent by the erythrocytes (red blood cells [RBCs]) traversing the microcirculation. Although it has been shown that the myocardium has regional differences in blood volume, blood flow, metabolism, and sensitivity to ischemic injury, the regional distribution of RBC transit times through the myocardial capillaries has not been previously measured. The present study was designed to measure the regional myocardial capillary RBC transit time by a new technique to determine whether there are regional differences in the capillary RBC transit time in the normal resting heart.

Analogues of F8Famide resistant to degradation, with high affinity and in vivo effects.

Four analogues of Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2, a mammalian FMRFamide-like peptide with antiopiate properties, were synthesized with N-terminus modifications and were shown to have high affinity for F8Famide binding sites. The degradation rate of these analogues in mouse brain slices was 3 times lower than that of the natural peptide. One analogue, (2DME)Y8Fa (D.

Early effect of gadopentetate and iodinated contrast media on rabbit kidneys.

Rationale And Objectives: The authors compared the physiologic and nephrotoxic effects of the magnetic resonance imaging contrast medium gadopentetate with two conventional radiographic contrast media.

Methods: Rabbits were injected intravenously with one of the following solutions: 1) gadopentetate (0.1 M); 2) iohexol (300 mg I/mL); 3) metrizoate (300 mg I/mL); and 4) NaCl (0.

Autoradiographic distribution of receptors to FLFQPQRFamide, a morphine-modulating peptide, in rat central nervous system.

The neuropeptide FLFQPQRFamide is a structure related to FMRFamide which is able to inhibit the effects of both endogenous and exogenous opiates. This morphine-modulating activity is mediated via the stimulation of specific FLFQPQRFamide receptors, different from opiate receptors. In vitro quantitative receptor autoradiography was performed on frozen sections of rat central nervous system to characterize binding properties and visualize FLFQPQRFamide receptors using the specific ligand [125I]YLFQPQRFamide, a radio-iodinated analogue of FLFQPQRFamide.

'Salvage atherectomy' for discrete arterial dissections resulting from balloon angioplasty.

Objective: To review the outcome of attempted salvage atherectomy performed following failed balloon angioplasty at a single centre.

Design: Retrospective study.

Patients: All patients undergoing percutaneous directional atherectomy shortly after failed coronary or peripheral balloon angioplasty at St Paul's Hospital, Vancouver, British Columbia, are reported.

Modulation of human lymphocyte proliferation by FLFQPQRFamide, a FMRFamide-like peptide with anti-opiate properties.

The octapeptide Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F8Fa), originally detected in mammalian brain by antisera raised against the invertebrate peptide Phe-Met-Arg-Phe-NH2 (FMRFamide) is a neuropeptide able to antagonize the actions of both endogenous and exogenous opiates. Since it is well accepted that lymphocytes are targets for opiates, we have tested the effect of F8Fa on T cell proliferation from normal human peripheral blood lymphocytes. Our study shows that F8Fa exerts a concentration-dependent diphasic modulation of human T lymphocyte proliferation.

DNA systematics and evolution of the artiodactyl family Bovidae.

Nine additional sequences from representatives of different tribes of the family Bovidae were combined with six published artiodactyl sequences to provide orthologous mtDNA for investigation of bovid phylogeny and evolution. Each species was represented by a homologous 2.7-kilobase-pair stretch of mtDNA for the complete 12S and 16S rRNA genes and three adjacent tRNA genes.

Nucleotide sequence variation in the mitochondrial 12S rRNA gene and the phylogeny of African mole-rats (Rodentia: Bathyergidae).

Mitochondrial DNA (mtDNA) sequence variation was examined in eight taxa of the African rodent family Bathyergidae, as well as in two taxa representative of the Old-World hystricognathid rodent families Petromyidae and Thryonomyidae. A total of 812 bp, constituting domains I-III of the 12S ribosomal rRNA gene, were compared for each taxon. The high levels of intrafamilial mtDNA sequence divergence observed (average 16.