Donald A. Thomas

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The organization and response properties of nociceptive neurons in area 1 of the primary somatosensory cortex (SI) of anesthetized monkeys were examined. The receptive fields of nociceptive neurons were classified as either wide-dynamic-range (WDR) neurons that were preferentially responsive to noxious mechanical stimulation, or nociceptive specific (NS)(More)
We have used quantitative zymography to measure levels of the type IV collagenases matrix metalloproteinase (MMP)-9 and MMP-2 in 42 biopsies of transitional cell carcinoma and in 7 biopsies of normal bladder. Mean levels of MMP-9 were significantly higher in tumor compared with normal samples (P = 0.08). Levels of MMP-9 and active MMP-2 increased with tumor(More)
We have examined the spinal analgesic activity of opioid agonists and antagonists in a model of short term, unilateral, carrageenan-induced inflammation/hyperalgesia. Rats received a single s.c. injection of carrageenan (2-6 mg in saline) 3-24 h prior to testing hindpaw withdrawal latencies to noxious thermal stimuli. Dose-response curves for intrathecally(More)
This study tested the ability of a nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME), to attenuate behavioral hyperalgesia in a rat model of neuropathic pain [Bennett, G.J. and Xie, Y.-K., Pain, 33 (1988) 87-107]. A mononeuropathy was produced by chronic constriction injury (CCI) of the sciatic nerve. Thermal hyperalgesia was(More)
We examined the effects of morphine microinjected into the medullary dorsal horn (MDH) on the ability of monkeys to detect temperature increases in the noxious heat range. Behavioral detection latency and the percentage of correct detections were used as measures of the perceived intensity of noxious heat stimuli. Three monkeys were trained to detect a(More)
BACKGROUND Pruritus is a common side effect of epidural and intrathecal morphine administration in humans. This naloxone-reversible pruritus is typically present on the trunk, but is often severe around the eyes and nose, of the patients. The brain stem has been proposed as the site where opioids act to produce this effect. The authors studied the effect of(More)
OBJECTIVES To determine whether loss of the tumour suppressor gene retinoblastoma (Rb) and increased expression of the p53 protein were associated with increased tumour cell growth fraction. PATIENTS AND METHODS Tumours from 105 patients (72 men, 33 women; median age 69 years, range 35-89) with newly diagnosed primary transitional cell bladder carcinoma(More)
Epidural and intrathecal administration of opioids to humans can produce facial pruritus and scratching that is naloxone reversible. It has been proposed that opioids may act at the level of the medulla to produce facial pruritus and associated scratching behavior. We investigated the effects of mu, delta and kappa opioid-receptor agonists microinjected(More)
Our hypothesis is that rotation increases apoptosis in standard tissue culture medium at shear stresses of greater than approximately 0.3 dyn/cm2. Human MIP-101 poorly differentiated colorectal carcinoma cells were cultured for 6 d in complete medium in monolayers, on Teflon®-coated nonadherent surfaces (static three-dimensional [3D]) or in rotating 3D(More)
In response to the U.S. President’s Vision for Space Exploration (January 14, 2004), NASA has revised its utilization plans for ISS to focus on (1) research on astronaut health and the development of countermeasures that will protect our crews from the space environment during long duration voyages, (2) ISS as a test bed for research and technology(More)