Carotid artery: percutaneous transbrachial selective arteriography with a 4-F catheter

Bilateral selective common carotid artery catheterization was attempted in 72 patients by means of percutaneous placement of a 4-F catheter from a right brachial artery puncture site in the antecubital fossa. The success rate was high (95.8%) and the complication rate low (6.9%), and there were no instances of brachial artery spasm or thrombosis. The experience, while small, suggests that selective common carotid arteriography can be done safely and efficaciously from the right brachial artery approach.     

Effects of dietary vanadium exposure on levels of regional brain neurotransmitters and their metabolites

Adult male CD-1 mice were treated with various levels of vanadate in drinking water for 30 days. The levels of catecholamine and indoleamine neurotransmitters and their major metabolites were measured in six different brain regions. Vanadium caused a dose-related decrease in norepinephrine (NE) levels in hypothalamus, the region rich in this biogenic amine. Levels of the NE metabolite, vanillylmandelic acid (VMA), correspondingly decreased in the same region. Although hypothalamic dopamine (DA) also showed a significant decline, vanadium had little effect on DA metabolites. Levels of 5-hydroxytryptamine (5-HT) and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were not influenced. Levels of DA were not affected in the corpus striatum, where the highest levels of this amine are observed. Effects of vanadium on various biogenic amines and their metabolites were only marginal in other brain regions. Results suggest that vanadium has a selective effect on adrenergic pathways, and effects on other hypothalamic amines appear to be secondary. These observations support the pro-oxidant potential of vanadate ion on catecholamines suggested earlier.     

Prolongation of islet xenograft survival by cryopreservation

Our attempt to reduce islet immunogenicity by slow cooling to -40 degrees C, storage at -196 degrees C, and rapid thawing is based on the differential susceptibility of various cell types to a freeze-thaw process. Five hundred rat islets (greater than or equal to 100 micron) were immediately implanted or cryopreserved and then implanted beneath the renal capsule of streptozocin-induced diabetic mice with or without an injection of anti-lymphocyte serum at the time of transplantation. Thirteen days after transplantation, all fresh xenografts had rejected, whereas 37.5% of cryopreserved grafts were still functioning. In immunosuppressed mice, 6.2% of fresh xenografts and 54.5% of cryopreserved grafts were functioning 19 days after transplantation. These results show that cryopreservation can extend xenograft survival.     

Evaluation of toluene exposure via drinking water on levels of regional brain biogenic monoamines and their metabolites in CD-1 mice

Toluene, a potentially neurotoxic substance, is found in trace amounts in groundwater. Adult male CD-1 mice were continuously fed drinking water ad libitum containing 0, 17, 80, and 405 mg/liter toluene. After a 28-day treatment, animals were tested for endogenous levels of the biogenic monoamines norepinephrine (NE), dopamine (DA), and serotonin (5-HT) and their respective metabolites. 3-methoxy-4-hydroxymandelic acid (VMA), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA), in six discrete brain regions. The maximum toluene-induced increases of biogenic amines and their metabolites generally occurred at a toluene concentration of 80 mg/liter. In the hypothalamus, a major NE-containing compartment, the concentrations of NE significantly increased by 51, 63, and 34% in groups dosed with 17, 80, and 405 mg/liter, respectively. Significant increases of NE were also observed in the medulla oblongata and midbrain. Concomitantly, concentrations of VMA increased in various brain regions. Concentrations of DA were significantly higher in the corpus striatum and hypothalamus. Alterations in levels of DA metabolites, DOPAC and HVA, were marginal. Toluene significantly increased concentrations of 5-HT in all dissected brain regions, except cerebellum, and increased the 5-HIAA levels in the hypothalamus, corpus striatum, and cerebral cortex.     

Coexpression of full-length gamma-aminobutyric acid(B) (GABA(B)) receptors with truncated receptors and metabotropic glutamate receptor 4 supports the GABA(B) heterodimer as the functional receptor

Direct evidence is lacking to show whether the gamma-aminobutyric acid (GABA)(B) gb1-gb2 heterodimer is the signaling form of the receptor. In this study, we tested whether gb1a or gb2 subunits when coexpressed with truncated receptors or metabotropic glutamate receptor mGluR4 could form functional GABA receptors. Coexpression of the ligand binding N-terminal domain of gb1a or the C-terminal portion of gb1a composing the seven-transmembrane segments and intracellular loops with gb2 could not reconstitute functional receptors. We next examined whether mGluR4, which forms homodimers and is structurally related to GABA(B), could act as a surrogate coreceptor for gb1 or gb2. The coexpression of mGluR4 and gb1a led to the expression of gb1a monomers on cell surface membranes as determined by immunoblot analysis and flow cytometry. However, mGluR4-gb1a heterodimers were not formed, and membrane-expressed gb1a monomers were not functionally coupled to adenylyl cyclase in human embryonic kidney 293 cells or activated inwardly rectifying potassium (Kir) channels in Xenopus oocytes. Similarly, the coexpression of mGluR4 and gb2 led to nonfunctional GABA receptors. GABA-activated distal signaling events resulted only after the coexpression and heterodimerization of gb1 and gb2. Taken together with the truncated receptor studies, the data suggest that a high degree of structural specificity is required to form the functional GABA(B) receptor that is a gb1-gb2 heterodimer.     

Migraine-associated vertigo

A retrospective analysis was performed on consecutive series of 363 patients presenting with vertigo; 32% had migraine. Of the 224 patients with no pathology other than migraine or vestibular dysfunction, migraineurs had a significantly higher prevalence of normal, central, and combined central and peripheral vestibular dysfunction compared to non-migraineurs. The combination of central and peripheral vestibular signs was a feature of migraine with aura. The results support the hypothesis that migraine-associated vertigo is a diagnostic entity.     

Isolation and characterization of murine cell surface components. I. Purification of milligram quantities of Thy-1.1

The Thy-l.1 molecule was isolated from the BW5147 murine lymphoblastoid cell line. The initial step in purification was the preparation of a crude plasma membrane fraction followed by acetone precipitation. The acetone pellet was solubilized using deoxycholate (DOC) and Thy-1.1 was purified by use of a Lens culinaris lectin affinity column and an AcA-34 gel filtration column. The purified glycoprotein with Thy-1.1 activity had a mol wt of approximately 25,000 daltons. The isolation of this molecule was effected by detecting Thy-I activity utilizing rabbit anti- mouse brain serum tested on rat thymocytes. Congenic anti-Thy-l.1 serum was ineffective in detecting Thy-l.1 after DOC solubilization. An antiserum prepared in rabbits to the purified Thy-1.1 was found to be cytotoxic to mouse and rat thymocytes. The cytotoxic activity of this antisera could be completely absorbed with AKR/Jax brain and thymus but was not absorbed by liver. In addition, AKR/Jax thymocytes totally absorbed all cytotoxic activity of the rabbit anti-purified Thy-1 serum for BW5147 cells suggesting that the cell line shares identical specificities with normal thymocytes. The purified Thy-1.1 molecule was able to totally absorb the cytotoxic activity of mouse congenic anti-Thy-1. These studies serve as a model for the isolation of other murine lymphoid cell surface components in quantities for detailed structural and functional analysis.     

The measurement of erythrocyte deformability using micropore membranes. A sensitive technique with clinical applications.

This article describes a positive-pressure filtration technique using low pore-density, 3 microns pore-diameter polycarbonate membranes employed to evaluate erythrocyte deformability in a clinically oriented hematology laboratory. Mean erythrocyte resistance to filtration was expressed by a numerical index which takes into account both the initial resistance of dilute red cell suspensions to passage across the membrane and the relative pressure rise observed after filtration of 30 ml of the same suspension (3 . 10(8) cells). The resistance index of 99 blood samples obtained from 88 healthy adult volunteers ranged between 1.4 and 2.9, with normal Gaussian distribution and mean of 2.04. Values obtained on similarly prepared samples from 20 patients with various hemolytic anemias always fell outside this range, indicating a reduced deformability in every case. The existence of a strong positive correlation was found between the resistance index and the degree of reticulocytosis in these patients. This method appears more sensitive than previously described filtration techniques in detecting the presence of small numbers of poorly deformable erythrocytes in vivo, while being more practical and statistically more significant than the micropipette elastimetry technique. Our results, however, raise a new question concerning the role of reticulocytes in the evaluation of red cell deformability on blood samples from patients with hemolytic anemia.