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Biomedical subjects

C A Owens

Publications and source records attributed to C A Owens.

At least 19 recordsLinked to original sources
PubMed1998

The inaccuracy of duplex ultrasonography in predicting patency of transjugular intrahepatic portosystemic shunts.

BACKGROUND & AIMS: A prospective double-blinded study with preset sonographic criteria has not been performed to assess the accuracy of duplex ultrasonography in determining the patency of transjugular intrahepatic portosystemic shunts (TIPS). The purpose of this study was to determine the sensitivity and specificity of duplex ultrasonography in predicting shunt malfunction using accepted preset sonographic criteria. METHODS: Sixty ultrasonographic and venographic follow-up comparisons were made on 38 cirrhotic patients who had undergone TIPS placement for variceal bleeding (n = 28) or intractable ascites (n = 10). Ultrasonographic results were analyzed by one of two board-certified ultrasonographers without knowledge of venographic findings. RESULTS: Of the 31 occluded (n = 8) and stenotic (n = 23) shunts, ultrasonography accurately predicted a shunt malfunction (occlusion or stenosis) in only 11 studies and incorrectly predicted patency in 20. Compared with venography, ultrasonography had a sensitivity of 35% and a specificity of 83% in predicting TIPS stenosis or occlusion. CONCLUSIONS: These results suggest that duplex sonography is not a sensitive test in predicting the presence of a hemodynamically significant stenosis and that shunt status should be assessed by venography and direct portal pressure measurements until a more reliable and proven noninvasive ultrasonographic criterion is devised.

Adult↗
PubMed1997

Lumbar but not cervical intrathecal DAMGO suppresses extrasegmental nociception in awake rats.

he effect of intrathecally administered [D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin (DAMGO) on withdrawal latencies evoked by noxious heat applied to either cervical or lumbar dermatomes was studied in awake rats. Administration of DAMGO to the lumbar intrathecal space produces a dose-dependent suppression of withdrawals evoked by noxious thermal stimulation in either lumbar or cervical dermatomes. Administration of the same doses of DAMGO to the cervical spinal cord produces a suppression of withdrawals evoked by stimulation in cervical but not lumbar dermatomes. Control experiments provide evidence that the drugs administered intrathecally to either enlargement do not spread to the other enlargement.

Analgesics, Opioid↗
PubMed1997

Pulmonary artery pseudoaneurysm after tube thoracostomy.

Pulmonary artery pseudoaneurysm has been described as a complication of Swan-Ganz catheterization and right heart catheterization. Isolated cases of this condition occurring in blunt and penetrating chest trauma have been reported. In this communication, we describe the case of a patient with intracranial hemorrhage who required positive-pressure ventilation and in whom subsequent pneumothorax developed, necessitating tube thoracostomy. A persistent opacification of the lung field resulted in evaluation with computed chest tomography and color-flow Doppler ultrasonography. A pseudoaneurysm of the lingular segmental artery was identified and successfully obliterated by Gelfoam coil embolization.

Aneurysm, False↗
PubMed1996

Cultured endometrial cancer cells exhibit autocrine growth factor stimulation that is not observed in cultured normal endometrial cells.

OBJECTIVE: To evaluate the autocrine stimulation hypothesis, primary cultures of malignant and normal endometrium were assayed for differences in response to growth factors (GF) GF and receptor blocking antibodies. METHODS: Thirteen normal and 10 malignant endometrial samples were collected. Cells were enzymatically dispersed and maintained in serum-free medium. They were incubated with epidermal GF (EGF), transforming GF-alpha (TGF-alpha), insulin-like GF-I (IGF-1), anti-EGF receptor antibody (Ab528), and anti-IGF-1 receptor antibody (alpha IR3) at physiologic concentrations. Tritiated thymidine incorporation was measured. RESULTS: Malignant endometrial cells increased thymidine incorporation when incubated with EGF (20.75%), TGF-alpha (19.8%), or IGF-1 (32.8%) compared to untreated control cells. When incubated with Ab528 or alpha IR3 antibodies alone, proliferation of malignant cells was inhibited (-12.4 and -23%, respectively, P < 0.003). Normal endometrial cells were inhibited by EGF (-24.9%), TGF-alpha (-25.6%), and IGF-1 (31.9%). Incubation of normal cells with Ab528 and alpha IR3 antibodies stimulated growth (125 and 115%, respectively, P < 0.02). CONCLUSIONS: These data are consistent with the autocrine stimulation hypothesis for neoplastic endometrium and illustrate differences compared to nonneoplastic endometrial growth factor-mediated proliferation.

Antibodies↗
PubMed1996

Antagonism of the antinocifensive action of halothane by intrathecal administration of GABAA receptor antagonists.

BACKGROUND: The hind brain and the spinal cord, regions that contain high concentrations of gamma-aminobutyric acid (GABA) and GABA receptors, have been implicated as sites of action of inhalational anesthetics. Previous studies have established that general anesthetics potentiate the effects of gamma-aminobutyric acid at the GABAA receptor. It was therefore hypothesized that the suppression of nocifensive movements during anesthesia is due to an enhancement of GABAA receptor-mediated transmission within the spinal cord. METHODS: Rats in which an intrathecal catheter had been implanted 1 week earlier were anesthetized with halothane. Core temperature was maintained at a steady level. After MAC determination, the concentration of halothane was adjusted to that at which the rats last moved in response to tail clamping. Saline, a GABAA, a GABAB, or glycine receptor antagonist was then injected intrathecally. The latency to move in response to application of the tail clamp was redetermined 5 min later, after which the halothane concentration was increased by 0.2%. Response latencies to application of the noxious stimulus were measured at 7-min intervals during the subsequent 35 min. To determine whether these antagonists altered baseline response latencies by themselves, another experiment was conducted in which the concentration of halothane was not increased after intrathecal administration of GABAA receptor antagonists. RESULTS: Intrathecal administration of the GABAA receptor antagonists bicuculline (0.3 micrograms) or picrotoxin (0.3, 1.0 micrograms) antagonized the suppression of nocifensive movement produced by the small increase in halothane concentration. In contrast, the antinocifensive effect of the increase in halothane concentration was not attenuated by the GABAB receptor antagonist CGP 35348 or the glycine receptor antagonist strychnine. By themselves, the GABAA receptor antagonists did not alter response latency in rats anesthetized with sub-MAC concentrations of halothane. CONCLUSIONS: Intrathecal administration of bicuculline or picrotoxin, at doses that do not change the latency to pinch-evoked movement when administered alone, antagonized the suppression of noxious-evoked movement produced by halothane concentrations equal to or greater than MAC. These results suggest that enhancement of GABAA receptor-mediated transmission within the spinal cord contributes to halothane's ability to suppress nocifensive movements.

Analgesics↗
PubMed1992

Formyl peptide stimulates and ATP gamma S potentiates [3H]cytidine 5'-diphosphate diglyceride accumulation in human neutrophils.

Although it is evident that the chemotactic peptide FMLP activates O2-formation in neutrophils via the phosphoinositidase-mediated second messenger system, it is less clear how endogenous priming agents such as ATP and platelet activating factor potentiate FMLP action. In our study, we have examined the possible effects of the stable ATP analog adenosine 5'-O-[3-thiotriphosphate] (ATP gamma S) on cellular levels of inositol 1,4,5-trisphosphate, [Ca2+]i and diglyceride (DG), in resting and in FMLP-stimulated neutrophils. Although all three measures were increased in the presence of FMLP, only the increase in DG was enhanced by pretreatment (priming) with ATP gamma S. We also measured the accumulation of the phosphoinositide cycle intermediate cytidine 5'-diphosphate (CDP)-DG to assess possible effects of priming on phosphoinositide resynthesis. The addition of FMLP to [3H]cytidine-prelabeled neutrophils elicited an increase in the accumulation of [3H]CDP-DG that was maximally enhanced in cells that were pretreated with cytochalasin B. The stimulated accumulation of [3H]CDP-DG was completely reversed by the addition of myo-inositol. Treatment of [3H]cytidine-prelabeled neutrophils with ATP gamma S (10-100 microM) resulted in a dose-dependent synergistic increase in FMLP-stimulated [3H]CDP-DG accumulation, whereas ATP gamma S alone had no effect. The observed increases in DG and in [3H]CDP-DG, in contrast to inositol 1,4,5-trisphosphate and [Ca2+]i responses, correlates well with the ATP gamma S-priming of FMLP-induced O2-formation. A similar potentiation of FMLP-induced stimulation of CDP-DG formation was also observed with platelet-activating factor. It is proposed that the priming of FMLP responses in neutrophils proceeds via a mechanism that selectively enhances DG production through a mechanism that is independent of FMLP-induced breakdown of phosphatidylinositol bisphosphate.

Adenosine Triphosphate↗
PubMed1991

Absence of FMLP receptors on rat macrophages.

Although rat peritoneal neutrophils in the presence of cytochalasin B demonstrate superoxide (O2-) responses to the chemotactic peptide N'-formyl-met-leu-phe (FMLP), neither elicited rat peritoneal macrophages nor rat alveolar macrophages show an O2- response to FMLP (in the presence or absence of cytochalasin B), although a good O2- response to opsonized zymosan is demonstrated by both types of macrophages. Using Fura-2 loaded cells, peritoneal macrophages failed to show an increase in intracellular calcium after exposure to FMLP, f-nor-leu-phe, F-met-met-met, or F-norleu-leu-phe-norleu-lys. FMLP also failed to induce elevations in intracellular calcium in alveolar macrophages. In 3H-FMLP binding studies, the lack of responsiveness of peritoneal and alveolar macrophages was associated with the lack of FMLP receptors on these cell types, in striking contrast to the presence of functional receptors on rat neutrophils.

Animals↗
PubMed1988

The role of promotion in alcoholism treatment marketing.

This article is an overview of the promotion function as a part of the ATM's marketing mix. It approaches various promotion decision areas from a managerial perspective, focusing upon some key components of promotion planning. Rather than provide specific operational or implementation details (how to write a brochure) it is more conceptual in nature and offers a framework for promotion planners. The article addresses promotion management, promotion objectives, analysis for promotion planning, the promotion mix, and addresses the benefits and limitations of some specific promotion tools available to the ATM manager. It treats ATMs as a service and reveals specific implications for promotion strategy dictated by services. The article also reports promotion tools employed by Alabama ATMs citing data from the Alabama study.

Advertising↗
PubMed1987

Thermic effects of tocolytic agents: decreased temperature with magnesium sulfate.

The effect of the tocolytic agents terbutaline and magnesium sulfate on patients' temperatures was examined. Fifty-two women admitted for preterm labor were randomized to a treatment protocol for one of the two agents. Oral temperatures were measured initially and every two hours during treatment. There was no significant difference between the initial temperature and the lowest temperature recorded during treatment in the terbutaline group, but temperature decreased significantly during treatment with magnesium sulfate. This decrease in maternal temperature may have importance in the treatment of preterm labor with magnesium sulfate in patients with an infectious etiology for uterine activity.

Adult↗