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T Ray

Publications and source records attributed to T Ray.

At least 19 recordsLinked to original sources
PubMed2006

Interaction of HIPPI with putative promoter sequence of caspase-1 in vitro and in vivo.

To investigate the mechanism of increased expression of caspase-1 in Hippi expressing HeLa and Neuro 2A cells, reported earlier, we report here that HIPPI directly interacted with upstream sequence of caspase-1 gene (-700 to +17, 717 bp). Deletion of this 717 bp sequence and further analysis by electrophoretic mobility shift assay and fluorescence quenching revealed that HIPPI interacted with 60 bp (-151 to -92) upstream sequence of caspase-1. We also observed by chromatin immunoprecipitation assay that HIPPI interacted with the 717 bp sequence in vivo. In luciferase assay, when expression of the reporter gene was driven by either 717 bp or 60 bp caspase-1 upstream sequences, luciferase activity was increased in GFP-Hippi expressing HeLa cells in comparison to that obtained with parental HeLa cells with the same constructs. Similar result was obtained in Neuro2A cells with 717 bp caspase-1 upstream sequence. In summary, we showed that HIPPI could interact with the putative promoter sequence of caspase-1 and increased the expression of the downstream gene suggesting that HIPPI could act as transcription regulator.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Intentional puncture of the dural space as an aid to epidural placement in a morbidly obese parturient.

OBJECTIVE: In this case report the authors discuss a technique occasionally employed at their institution to aid in identification of the epidural space in morbidly obese parturients. CASE REPORT: A 29-year-old primagravida, with a body mass index of 90 (155 cm tall, 215 kg) presented for induction of labor. A 27-ga. Sprotte spinal needle was intentionally passed through a Weiss epidural needle and into the subarachnoid space to confirm placement of the Weiss needle in the epidural space. An epidural catheter was then placed which functioned well for labor and subsequent caesarian delivery. CONCLUSIONS: In selected patients, intentional puncture of the dura can aid in confirmation of the epidural space.

Adult↗
PubMed2000

High-throughput approaches to the quantitative analysis of ketoconazole, a potent inhibitor of cytochrome P450 3A4, in human plasma.

Ketoconazole, an imidazole-piperazine compound, is an orally active antimycotic agent. In addition, ketoconazole is a specific inhibitor of cytochrome P450 3A4. As about 60% of oxidized drugs are biotransformed by this isoform, the potential effect of a concomitant administration of ketoconazole on drug disposition may be of interest during drug development. The present paper describes three different approaches (methods A, B, and C) to attain high-throughput sample preparation and analysis in the quantification of ketoconazole in human plasma. Method A consisted of acetonitrile precipitation in a 96-well plate, transfer of the supernatant via a Tomtec Quadra 96 Model 320, and subsequent injection onto a 50 x 4.6 mm (i.d.) Develosil Combi-RP-5 column (packed with C30 bonded silica particles). Method B consisted of an identical sample preparation to method A with the exception that a Michrom Magic Bullet(trade mark) column, 2.0 --> 0.50 mm (i.d., tapered bore) x25 mm length, was used. Lastly, in method C, a turbulent-flow chromatography (TurboFlow LC/APCI-MS/MS) module was used for the direct analysis of ketoconazole in human plasma. A Sciex API 3000 was used in methods A and B, while a Micromass Quattro LC was employed in method C. Based on the values obtained for the calibrator (standard) and quality control samples, all three protocols yielded satisfactory accuracy, precision, and reduced manual sample preparation time.

Antifungal Agents↗
PubMed1998

Prophylactic angiotensin II infusion during spinal anesthesia for elective cesarean delivery.

BACKGROUND: Angiotensin II may prove useful in treating regional anesthesia-induced hypotension in obstetric patients, because it causes less uterine vasoconstriction than do other vasoconstrictor drugs (such as phenylephrine). This study compared (1) maternal blood pressure and heart rate and (2) fetal status at delivery in parturients given either prophylactic angiotensin II or ephedrine infusion during spinal anesthesia for elective cesarean delivery. METHODS: Fifty-four women were randomized to receive either angiotensin II or ephedrine infusion intravenously during spinal anesthesia for elective cesarean section delivery. Simultaneous with subarachnoid injection, infusion of angiotensin II (2.5 microg/ml) or ephedrine (5 mg/ml) was initiated at 10 ng x kg(-1) x min(-1) and 50 microg x kg(-1) x min(-1), respectively. The rate of each infusion was adjusted to maintain maternal systolic blood pressure at 90-100% of baseline. RESULTS: Cumulative vasopressor doses (mean+/-SD) through 10, 20, and 30 min were 150+/-100, 310+/-180, and 500+/-320 ng/kg in the angiotensin group and 480+/-210, 660+/-390, and 790+/-640 microg/kg in the ephedrine group. Maternal heart rate was significantly higher (P < 0.001) during vasopressor infusion in the ephedrine group than in the angiotensin group. Umbilical arterial and venous blood pH and base excess were all significantly higher (P < 0.05) in the angiotensin group than in the ephedrine group. CONCLUSIONS: Angiotensin II infusion maintained maternal systolic blood pressure during spinal anesthesia without increasing maternal heart rate or causing fetal acidosis.

Acid-Base Equilibrium↗
PubMed1997

Syndesmotic screw placement: a biomechanical analysis.

At the present time, syndesmotic screw fixation is recommended when there is a tibiofibular diastasis, a Maisonneuve fracture, or syndesmotic instability after fixation of distal tibia-fibula fractures. The aim/purpose of this study was to demonstrate the optimal level of syndesmotic screw placement before creation of a Maisonneuve fracture. Legs of 17 embalmed cadavers underwent knee disarticulation. The legs were then dissected to expose the syndesmosis/interosseous membrane. The paired cadaver legs were tested in two groups. In group I (10 pairs), the left legs were tested without any syndesmotic fixation and the right legs were tested with the syndesmosis fixed at 2.0 cm above the tibiotalar joint. In group II (7 pairs), the syndesmosis in each left leg was fixed at 3.5 cm above the tibiotalar joint and the right leg syndesmosis was fixed at 2.0 cm above the tibiotalar joint. After ligament section and syndesmosis fixation, each leg was then jig mounted with transfixing wires through the proximal tibia and calcaneus. The ankle was placed in neutral with 15 degrees of pronation and a load of 150 pounds and a strain gauge anchored medially and laterally. The proximal tibia was internally rotated while the ankle was held fixed until syndesmotic, bony, or hardware failure occurred. Torsional force, the degree of rotation and the amount of syndesmotic widening were quantitated. Two-tailed t-test comparing no fixation with fixation at 2.0 cm indicated less syndesmotic widening with screw placed at 2.0 cm (P = 0.04). Two-tailed t-test comparing screw fixation at 2.0 cm and 3.5 cm indicated less syndesmotic widening with screw placed at 2.0 cm (P = 0.07). It would seem reasonable to place a syndesmotic screw at 2.0 cm above tibiotalar joint.

Ankle Injuries↗
PubMed1995

Tris-dependent oxidative DNA strand scission during electrophoresis.

The DNA of two Streptomyces species contains site-specific labile modifications. During gel electrophoresis the DNA can undergo Tris-dependent strand scission at the positions of these modifications. Our investigations into the nucleolytic activity which reacts with the modifications implicate a peracid derivative of Tris formed at the anode; the kinetics of production and decay of this activity were followed using both a DNA cleavage assay and a reduced methyl viologen assay to measure oxidant. Anode activation could be chemically mimicked by addition of peracetic acid to Tris buffers. We tested the DNA cleavage activity of several other compounds after anode or chemical activation; we used an analogue of Tris lacking a primary amine group and also several reagents known to promote DNA strand cleavage by amine-catalysis at abasic sites. Anode generation of oxidant could be detected for compounds containing either hydroxyl or carboxyl groups. However, DNA cleavage activity correlated with oxidant formation only for those compounds also containing primary amine groups. These results support a mechanism of DNA strand scission at modification sites via concerted peracid-mediated oxidative and amine-catalysed reactions. The novel finding of Tris-dependent formation of a long-lived reactive oxidant at the anode suggests that this compound is unsuited as an electrophoresis buffer for certain biological macromolecules.

Amines↗
PubMed1992

Tris-dependent site-specific cleavage of Streptomyces lividans DNA.

During conventional gel electrophoresis, Streptomyces lividans DNA undergoes site-specific double-strand cleavage at the positions of closely opposed unstable modifications introduced into the DNA in vivo. We investigated this electrophoretic instability and demonstrated that it was dependent on Tris. Tris buffer was activated at the anode to generate a nucleolytic species; prior to activation, Tris was not able to cleave the DNA. The nucleolytic species was shown to react with thiourea, which could thus protect the DNA from strand cleavage. Non-degradative electrophoresis of the DNA could also be achieved in an alternative buffer such as Hepes.

Binding Sites↗
PubMed1987

Subinhibitory concentrations of tetracycline alter fibrinogen binding by Bacteroides intermedius.

Previous studies from our laboratory have shown that a strain of Bacteroides intermedius, VPI 8944, an organism isolated originally from a patient with acute necrotizing ulcerative gingivitis, binds human fibrinogen rapidly, reversibly, specifically, saturably, and with high affinity (M.S. Lantz, L.M. Switalski, K.S. Kornman, and M. Höök, J. Bacteriol. 163:623-628, 1985). We examined the effect of growth in subinhibitory levels (sub-MICs) of tetracycline on fibrinogen binding by these bacteria and found concentration-dependent inhibition of fibrinogen binding by bacteria grown in the presence of tetracycline over the range of tetracycline concentrations from 1/64 to 1/8 the MIC. Analysis of the binding data suggests that bacteria grown in the presence of sub-MICs of tetracycline bind fewer fibrinogen molecules per cell than do bacteria grown in the absence of the drug. If fibrinogen-mediated adherence is important in the establishment B. intermedius in periodontal lesions and lesions of acute necrotizing ulcerative gingivitis, then tetracycline may be effective in disrupting establishment of these organisms at concentrations well below those required to achieve a bacteriostatic effect.

Bacteroides↗
PubMed1982

Abnormalities in monoamine levels in the central nervous system of the genetically epilepsy-prone rat.

Norepinephrine, dopamine, and 5-hydroxytryptamine concentrations were determined in the central nervous systems of genetically epilepsy-prone rats (GEPR) and in control rats. Norepinephrine concentrations were abnormal in all major areas of the central nervous system of the GEPR, with decrements existing in the telencephalon, hypothalamus-thalamus, midbrain, pons-medulla and spinal cord. An increment in the concentration of this neurotransmitter existed in the cerebellum. Dopamine concentrations were normal in all areas of the GEPR brain. Abnormalities in 5-hydroxytryptamine concentrations were also present in the GEPR. They were exclusively decrements and occurred in the telencephalon, hypothalamus-thalamus, midbrain, and pons medulla. Concentrations of this neurotransmitter were normal in the cerebellum and spinal cord. Coupled with our earlier pharmacologic data, these observations support our concept that noradrenergic and/or 5-hydroxytryptaminergic decrements are etiologically important in seizure susceptibility in the GEPR. The lack of abnormalities in brain dopamine concentrations strengthens our hypothesis that dopaminergic transmission does not regulate seizure susceptibility in this model.

Animals↗
PubMed1980

Paroxysmal facial neuralgia secondary to a posterior communicating artery aneurysm.

Paroxysmal facial neuralgia, typified by classical tic douloureux, may be secondary to intermittent compression of the trigeminal nerve by pulsating vascular structures. The critical area of compression, at least for producing true trigeminal neuralgia, is felt to be the dorsal root entry zone. One case of paroxysmal facial neuralgia, secondary to more distal compression of the trigeminal nerve by a large posterior communicating artery aneurysm, is reported here. The location of the compression may be important in producing the atypical characteristics of paroxysmal facial neuralgia that is not classical tic douloureux. The pain was relieved by clipping the aneurysm without excision or rupture of the sack.

Facial Neuralgia↗
PubMedDate not supplied

Effect of 'Compound R' on thermal burn and full-depth wound contracture in fuzzy rats.

We evaluated the efficacy of Compound R emulsion on wound contraction in fuzzy rats. While the rats were under anesthesia, two mirror-image burn wounds were inflicted on the depilated back skin of each. Wounds were assigned randomly to treatment or placebo (oil), and the wound-scar areas were measured when they healed. A second set of wounds was created by taking two 6 millimeter punch biopsies from each rat and treated with Compound R or placebo. Under anesthesia, areas of the wound were measured on days 0, 5, 8 and on healing. Mean+/-SE areas for the healed burn wounds were: 151+/-24 mm2 for the treated and 102+/-26 mm2 for the placebo side (paired Student's t test, t=4.21, p=0.0015). Areas for Compound R-treated punch biopsy-induced wounds were significantly larger than placebo treated at each time point (p < 0.01). Results from this study show that Compound R impeded wound contraction.

Animals↗