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Wolf CR, Smith G, Smith RL. Science, medicine, and the future: Pharmacogenetics. BMJ (CLINICAL RESEARCH ED.) 2000; 320:987-90. [PMID: 10753155 PMCID: PMC1117913 DOI: 10.1136/bmj.320.7240.987] [Citation(s) in RCA: 214] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Harper M, Thompson TL, Zhu YN, Smith RL, Carden D, Coe L, Alexander B, Alexander JS. Rapid, high-yield method for the bulk purification of fibronectin from human plasma. Biotechniques 2000; 28:636-8. [PMID: 10769740 DOI: 10.2144/00284bm05] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Smith RL, Edwards MJ, Notaras E, O'Loughlin EV. Esophageal dysmotility in brothers with an FG-like syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS 2000; 91:185-9. [PMID: 10756339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
We present 4 brothers with developmental delay, minor anomalies, and symptoms due to gastrointestinal dysmotility. There was some resemblance with FG syndrome, although none of the brothers had sufficient findings to make this diagnosis. The index case presented with at age 1 month with screaming episodes, mild gastro-esophageal reflux (GER), and severe constipation. Esophageal manometry studies were consistent with the diagnosis of "nutcracker esophagus." Symptomatic and manometric improvement followed treatment with oral calcium channel blockers. Two older and less severely affected brothers had similar manometric findings but did not require treatment. A fourth brother with symptoms in infancy now has normal esophageal manometry findings. These boys in all likelihood have an X-linked syndrome with manifestations of FG syndrome, in which treatment with calcium channel blockers, produces clinical and manometric improvement. The FG syndrome is an X-linked syndrome of multiple congenital anomalies/mental retardation with facultative manifestations of gastrointestinal dysmotility, including gastro-esophageal reflux, severe feeding difficulties, and constipation. Esophageal dysmotility, in particular "nutcracker esophagus," should be suspected in infants with the FG syndrome and screaming attacks.
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Smith RL, Lin J, Trindade MC, Shida J, Kajiyama G, Vu T, Hoffman AR, van der Meulen MC, Goodman SB, Schurman DJ, Carter DR. Time-dependent effects of intermittent hydrostatic pressure on articular chondrocyte type II collagen and aggrecan mRNA expression. JOURNAL OF REHABILITATION RESEARCH AND DEVELOPMENT 2000; 37:153-61. [PMID: 10850821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The normal loading of joints during daily activities causes the articular cartilage to be exposed to high levels of intermittent hydrostatic pressure. This study quantified effects of intermittent hydrostatic pressure on expression of mRNA for important extracellular matrix constituents. Normal adult bovine articular chondrocytes were isolated and tested in primary culture, either as high-density monolayers or formed aggregates. Loaded cells were exposed to 10 MPa of intermittent hydrostatic pressure at a frequency of 1 Hz for periods of 2, 4, 8, 12, and 24 hrs. Other cells were intermittently loaded for a period of 4 hrs per day for 4 days. Semiquantitative reverse transcription polymerase chain reaction assays were used to assess mRNA signal levels for collagen types II and I and aggrecan. The results showed that type II collagen mRNA signal levels exhibited a biphasic pattern, with an initial increase of approximately five-fold at 4 and 8 hrs that subsequently decreased by 24 hrs. In contrast, aggrecan mRNA signal increased progressively up to three-fold throughout the loading period. Changing the loading profile to 4 hrs per day for 4 days increased the mRNA signal levels for type II collagen nine-fold and for aggrecan twenty-fold when compared to unloaded cultures. These data suggest that specific mechanical loading protocols may be required to optimally promote repair and regeneration of diseased joints.
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Corsetti JP, Sparks JD, Peterson RG, Smith RL, Sparks CE. Effect of dietary fat on the development of non-insulin dependent diabetes mellitus in obese Zucker diabetic fatty male and female rats. Atherosclerosis 2000; 148:231-41. [PMID: 10657558 DOI: 10.1016/s0021-9150(99)00265-8] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The obese Zucker diabetic fatty male rat (ZDF/Gmi¿trade mark omitted¿-fa) has become a widely used animal model of NIDDM, in contrast to the obese ZDF females that rarely develop NIDDM. However, preliminary observations suggest that obese ZDF females may become diabetic on high-fat diets. Therefore, we studied the effect of dietary fat on development of NIDDM, dyslipidemia, and alterations in organ-specific serum panels in obese ZDF males and females. Results indicated different effects of dietary fat-content on development of diabetes in males and females. Males, even on low fat-content diets, developed diabetes but the process was accelerated as a function of dietary fat-content, whereas only the highest fat-content diet induced development of NIDDM in obese ZDF females. Additionally, triglyceride/apolipoprotein B ratios demonstrated gender-specific differences in the nature of circulating lipoprotein particles independent of diabetic state with values for females approximately twice those of males indicating more highly triglyceride-enriched lipoprotein particles in females. We conclude that the obese ZDF female rat has the potential to become an important animal model of NIDDM especially in women where few models currently exist.
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Smith RL, Brown DH. Shy-Drager syndrome: an otolaryngology perspective. THE JOURNAL OF OTOLARYNGOLOGY 2000; 29:59-61. [PMID: 10709176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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Carr MM, Schmidbauer JA, Majaess L, Smith RL. Communication after laryngectomy: an assessment of quality of life. Otolaryngol Head Neck Surg 2000; 122:39-43. [PMID: 10629480 DOI: 10.1016/s0194-5998(00)70141-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The purpose of this study was to examine quality of life in laryngectomees using different methods of communication. A survey was mailed to all the living laryngectomees in Nova Scotia. Patients were asked to rate their ability to communicate in a number of common situations, to rate their difficulty with several communication problems, and to complete the EORTC QLQ-C30 quality-of-life assessment tool. Sixty-two patients responded (return rate of 84%); 57% were using electrolaryngeal speech, 19% esophageal speech, and 8.5% tracheoesophageal speech. These groups were comparable with respect to age, sex, first language, education level, and years since laryngectomy. There were very few differences between these groups in ability to communicate in social situations and no difference in overall quality of life as measured by these scales. The most commonly cited problem was difficulty being heard in a noisy environment. Despite the fact that tracheoesophageal speech is objectively most intelligible, there does not seem to be a measurable improvement in quality of life or ability to communicate in everyday situations over electrolaryngeal or esophageal speakers.
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Davis JL, Smith RL. Painful peripheral diabetic neuropathy treated with venlafaxine HCl extended release capsules. Diabetes Care 1999; 22:1909-10. [PMID: 10546032 DOI: 10.2337/diacare.22.11.1909] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Trindade MC, Nakashima Y, Lind M, Sun DH, Goodman SB, Maloney WJ, Schurman DJ, Smith RL. Interleukin-4 inhibits granulocyte-macrophage colony-stimulating factor, interleukin-6, and tumor necrosis factor-alpha expression by human monocytes in response to polymethylmethacrylate particle challenge in vitro. J Orthop Res 1999; 17:797-802. [PMID: 10632444 DOI: 10.1002/jor.1100170602] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The outcome of total joint arthroplasty is determined by biological events at the bone-implant interface. Macrophages phagocytose implant or wear debris at the interface and release proinflammatory mediators such as interleukins 1 and 6, tumor necrosis factor-alpha, and prostaglandin E2. These mediators are thought to contribute to the resorption of periprosthetic bone. Previous studies of tissues harvested from the bone-implant interface of failed orthopaedic implants demonstrated a possible role for two other cytokines, granulocyte-macrophage colony-stimulating factor and interleukin-4. The present study examined the effects of in vitro challenge with polymethylmethacrylate particles on the expression of granulocyte-macrophage colony-stimulating factor by primary human monocytes/macrophages and the role of interleukin-4 in regulating this expression. The polymethylmethacrylate particles caused a dose-dependent release of granulocyte-macrophage colony-stimulating factor at 48 hours. This release was accompanied by increased expression of interleukins 6 and 1beta and tumor necrosis factor-alpha. Release of the lysosomal enzyme hexosaminidase also increased in response to the particles. Interleukin-4 inhibited the expression of granulocyte-macrophage colony-stimulating factor, interleukin-6, and tumor necrosis factor-alpha at 48 hours in a dose-dependent manner. The data presented in this study confirm the hypothesis that interleukin-4 downregulates particle-induced activation of macrophages, as demonstrated by the decreased release of proinflammatory mediators.
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Dobrozsi DJ, Smith RL, Sakr AA. Comparative mucoretention of sucralfate suspensions in an everted rat esophagus model. Int J Pharm 1999; 189:81-9. [PMID: 10518688 DOI: 10.1016/s0378-5173(99)00244-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A simple, rapid, and reproducible in vitro model was established to quantify the relative esophageal mucoadhesive properties of viscous liquid formulations, and the model was applied to compare marketed sucralfate suspensions (Gastrogel, Antepsin, and Ulcogant) to better understand differences in clinical performance. Rat esophageal mucosal segments were everted onto a glass rod and briefly immersed into a liquid formulation containing 51Cr microspheres. Indirect quantification of the retained formulation provided excellent recovery (98.7-101%) and reasonable precision (1.06-38.3% CV). Mucosal retention profiles of the formulations were determined by rinsing the coated tissue in relevant gastrointestinal fluids using the technique of reciprocating vertical immersion. Dispersions of the mucoadhesive hydrogel Carbopol 934P were employed to initially characterize the performance of the model with respect to composition of the rinse fluids, and type and amount of shear force during rinsing. Retention of Carbopol was sensitive to the mechanics of rinsing and to salivary salts but not mucin in the rinse medium. A sucralfate gel suspension (Gastrogel) showed much greater mucoadhesion and resistance to removal by saliva than two non-gel suspensions (Antepsin, Ulcogant). Results suggest that in situ gelation may be a contributing mechanism for strong esophageal retention. These in vitro results are in general agreement with published human esophageal retention data on similar sucralfate suspensions and lend credence to the everted rat esophagus as a qualitatively predictive in vitro model for development of esophageal mucoadhesive liquids.
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Smith RL. Degradative enzymes in osteoarthritis. FRONTIERS IN BIOSCIENCE : A JOURNAL AND VIRTUAL LIBRARY 1999; 4:D704-12. [PMID: 10525483 DOI: 10.2741/a388] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A central feature of the osteoarthritic disease process involves erosive destruction of the articular cartilage extracellular matrix (ECM) on the surfaces of diarthrotic joints. The resultant loss of joint function makes studies on mechanisms underlying ECM degradation critical for treatment of the disease and prevention of disability. Candidate pathways to account for the loss of cartilage involve expression of a combination of proteases that degrade the major cartilage matrix macromolecules, aggrecan and type II collagen. The specific types of enzymatic activities associated with the progressive removal of ECM and severity of joint disease include the matrix metalloproteinases, collagenase, gelatinase and aggrecanase(s). The degradative enzymes originate in synovial cells, cartilage cells, the chondrocytes, distributed within the ECM and leukocytes that actively invade the joint space. Specific enzymes arising from each of these tissues exhibit selective ECM degrading properties; the different categories of these tissue-derived enzymes will be discussed in this chapter. A perspective on the efficacy of existing agents and the potential for development of novel therapeutic agents is also included. While the degradative enzymes serve as a focal point for therapeutic intervention, a fundamental understanding of the mechanisms underlying degradative enzyme expression in osteoarthritis remains an important goal for prevention of disease.
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Trindade MC, Lind M, Goodman SB, Maloney WJ, Schurman DJ, Smith RL. Interferon-gamma exacerbates polymethylmethacrylate particle-induced interleukin-6 release by human monocyte/macrophages in vitro. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1999; 47:1-7. [PMID: 10400874 DOI: 10.1002/(sici)1097-4636(199910)47:1<1::aid-jbm1>3.0.co;2-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Periprosthetic membranes commonly observed at sites of total joint implant loosening exhibit abundant macrophages and particulate debris. Macrophages phagocytose orthopedic debris and release the pro-inflammatory mediators interleukin-1, interleukin-6, tumor necrosis factor-alpha, and prostaglandin E2. In addition, other immunologic agents, such as interferon-gamma, are present in tissues harvested from the bone-implant interface of failed orthopedic implants. The present study examined the effects of interferon-gamma on polymethylmethacrylate (PMMA) particle-challenged monocyte/macrophages in vitro. The effects of interferon-gamma were determined by measuring interleukin-6 and tumor necrosis factor-alpha release by primary human monocyte/macrophages following exposure to PMMA particles. Exposure of the monocyte/macrophages to PMMA particles resulted in a dose-dependent release of interleukin-6 and tumor necrosis factor-alpha at 48 h. The interleukin-6 release in response to PMMA particle challenge was stimulated by 76% and 127% in the presence of 1.0 and 10.0 ng/mL of interferon-gamma, respectively. Interferon-gamma challenge alone did not alter interleukin-6 release relative to controls. In contrast to interleukin-6, interferon-gamma challenge stimulated tumor necrosis factor-alpha release in a dose-dependent manner. In the presence of particles, addition of 1.0 and 10.0 ng/mL of interferon-gamma resulted in 17% and 171% increases in the levels of tumor necrosis factor-alpha release, respectively, relative to cultures challenged solely with particles. Blocking antibody to IFN-gamma inhibited the effect of IFN-gamma on particle-induced interleukin-6 and tumor necrosis factor-alpha release. The data presented in this study demonstrate that the immunologic modulator interferon-gamma exacerbates monocyte/macrophage release of the pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in response to PMMA particle challenge in vitro.
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Trindade MC, Song Y, Aspenberg P, Smith RL, Goodman SB. Proinflammatory mediator release in response to particle challenge: studies using the bone harvest chamber. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1999; 48:434-9. [PMID: 10421684 DOI: 10.1002/(sici)1097-4636(1999)48:4<434::aid-jbm6>3.0.co;2-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This study reports on the effects of phagocytosable particles on proinflammatory mediator release in an animal model. Bone harvest chambers (BHCs) were implanted bilaterally into mature rabbits; phagocytosable ultrahigh molecular weight polyethylene (UHMWPE) and polystyrene (PS) particles, and the carrier sodium hyaluronate (HE) were tested for their ability to stimulate proinflammatory mediator release. Tissues were harvested after 3, 4, or 6 weeks. Retrieved tissues were placed into culture medium. The release of the proinflammatory mediators interleukin-6 (IL-6), interleukin-1beta (IL-1beta), and tumor necrosis factor alpha (TNF-alpha) into the culture medium was assessed using bioassays. DNA content and dry weights were also measured. The maximal biological response to the PE particles with respect to TNF-alpha and IL-1beta was observed at three weeks with 11- and fivefold stimulations over controls, respectively. The maximal response to PE particles with respect to IL-6 was observed at 4 weeks with a twofold stimulation over controls. Similar patterns were seen with PS particles; however, PE particles stimulated higher cytokine release. PE particles stimulated the expression of IL-1beta, IL-6, and TNF-alpha in the BHC model. Cell culture and human retrieval studies also implicate these proinflammatory mediators in loosening and osteolysis of total joint replacements. Thus, the BHC is a useful in vivo model to document the effects of particles on the evolution of biological responses to particulate debris.
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Newberne P, Smith RL, Doull J, Goodman JI, Munro IC, Portoghese PS, Wagner BM, Weil CS, Woods LA, Adams TB, Lucas CD, Ford RA. The FEMA GRAS assessment of trans-anethole used as a flavouring substance. Flavour and Extract Manufacturer's Association. Food Chem Toxicol 1999; 37:789-811. [PMID: 10496381 DOI: 10.1016/s0278-6915(99)00037-x] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This publication is the fourth in a series of safety evaluations performed by the Expert Panel of the Flavour and Extract Manufacturers' Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavouring substances under conditions of intended use. In this review, scientific data relevant to the safety evaluation of trans-anethole (i.e. 4-methoxypropenylbenzene) as a flavouring substance is critically evaluated by the FEMA Expert Panel. The evaluation uses a mechanism-based approach in which production of the hepatotoxic metabolite anethole epoxide (AE) is used to interpret the pathological changes observed in different species and sexes of laboratory rodents in chronic and subchronic dietary studies. Female Sprague Dawley rats metabolize more trans-anethole to AE than mice or humans and, therefore, are the most conservative model for evaluating the potential for AE-induced hepatotoxicity in humans exposed to trans-anethole from use as a flavouring substance. At low levels of exposure, trans-anethole is efficiently detoxicated in rodents and humans primarily by O-demethylation and omega-oxidation, respectively, while epoxidation is only a minor pathway. At high dose levels in rats, particularly females, a metabolic shift occurs resulting in increased epoxidation and formation of AE. Lower activity of the "fast" acting detoxication enzyme epoxide hydrolase in the female is associated with more pronounced hepatotoxicity compared to that in the male. The continuous intake of high dose levels of trans-anethole (i.e. cumulative exposure) has been shown in dietary studies to induce a continuum of cytotoxicity, cell necrosis and cell proliferation. In chronic dietary studies in rats, hepatotoxicity was observed when the estimated daily hepatic production of AE exceeded 30 mg AE/kg body weight. In female rats, chronic hepatotoxicity and a low incidence of liver tumours were reported at a dietary intake of 550 mg trans-anethole/kg body weight/day. Under these conditions, daily hepatic production of AE exceeded 120 mg/kg body weight. Additionally, neither trans-anethole nor AE show any evidence of genotoxicity. Therefore, the weight of evidence supports the conclusion that hepatocarcinogenic effects in the female rat occur via a non-genotoxic mechanism and are secondary to hepatotoxicity caused by continuous exposure to high hepatocellular concentrations of AE. trans-Anethole was reaffirmed as GRAS (GRASr) based on (1) its low level of flavour intake (54 microg/kg body weight/day); (2) its metabolic detoxication pathway in humans at levels of exposure from use as a flavouring substance; (3) the lack of mutagenic or genotoxic potential; (4) the NOAEL of 120 mg trans-anethole/kg body weight/day in the female rat reported in a 2 + -year study which produces a level of AE (i.e. 22 mg AE/kg body weight/day) at least 10,000 times the level (0.002 mg AE/kg body weight day) produced from the intake of trans-anethole from use as a flavouring substance; and (5) the conclusion that a slight increase in the incidence of hepatocellular tumours in the high dose group (550 mg trans-anethole/kg body weight/day) of female rats was the only significant neoplastic finding in a 2+ -year dietary study. This finding is concluded to be secondary to hepatotoxicity induced by high hepatocellular concentrations of AE generated under conditions of the study. Because trans-anethole undergoes efficient metabolic detoxication in humans at low levels of exposure, the neoplastic effects in rats associated with dose-dependent hepatotoxicity are not indicative of any significant risk to human health from the use of trans-anethole as a flavouring substance.
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Collins SD, Smith RL, Gonzalez C, Stewart KP, Hagopian JG, Sirota JM. Fourier-transform optical microsystems. OPTICS LETTERS 1999; 24:844-846. [PMID: 11543549 DOI: 10.1364/ol.24.000844] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The design, fabrication, and initial characterization of a miniature single-pass Fourier-transform spectrometer (FTS) that has an optical bench that measures 1 cm x 5 cm x 10 cm is presented. The FTS is predicated on the classic Michelson interferometer design with a moving mirror. Precision translation of the mirror is accomplished by microfabrication of dovetailed bearing surfaces along single-crystal planes in silicon. Although it is miniaturized, the FTS maintains a relatively high spectral resolution, 0.1 cm-1, with adequate optical throughput.
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Smith RL, Barrett RJ, Sanders-Bush E. Mechanism of tolerance development to 2,5-dimethoxy-4-iodoamphetamine in rats: down-regulation of the 5-HT2A, but not 5-HT2C, receptor. Psychopharmacology (Berl) 1999; 144:248-54. [PMID: 10435391 DOI: 10.1007/s002130051000] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
RATIONALE Defining the mechanism of tolerance development to hallucinogenic drugs will help to explain their mechanism of action. OBJECTIVES The present study was conducted to determine first, if tolerance develops to the discriminative stimulus (DS) properties of the hallucinogen, 2,5 dimethoxy-4-iodo-amphetamine (DOI) and second, the mechanism mediating tolerance. METHODS Rats were trained to discriminate 0.75 mg/kg DOI from saline on a concurrent VI-30-min schedule of reinforcement with a 15-min time-out for incorrect responses. To evaluate tolerance development, rats were assigned to one of four groups and treated with either chronic saline or chronic DOI. Prior to chronic treatment, two groups were tested for choice behavior following vehicle administration while the remaining two groups were tested following the administration of 0.375 mg/kg DOI. One group from each pre-test condition was injected with either saline or DOI (1 mg/kg) for 8 days. Twenty-four hours after the last chronic injection the pre-test treatments were replicated. Using receptor autoradiography, the density of 5-HT2A and 5-HT2C receptors was measured in independent groups of rats that had received identical treatment conditions. RESULTS Animals receiving chronic DOI showed a 60% decrease in DOI lever responding (from 100% to 40%) when tested on 0.375 mg/kg DOI, while animals receiving chronic saline showed no change in percent choice (100%) on the DOI lever. Significant changes in binding were observed in 5-HT2A receptors but not 5-HT2C receptors. The results of tests with antagonists were consistent with the changes in binding. CONCLUSIONS These results suggest that behavioral tolerance to DOI reflects neuroadaptive changes in 5-HT2A receptors.
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Smith RL, Davis JM, Speckman P. Assessing the human health risk of atmospheric particles. NOVARTIS FOUNDATION SYMPOSIUM 1999; 220:59-72; discussion 72-9. [PMID: 10231825 DOI: 10.1002/9780470515600.ch4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The health implications of atmospheric particulate matter have become a topic of much interest on both sides of the Atlantic, but especially in the USA, where they were at the centre of the debate over the Environmental Protection Agency's (EPA) revision of the National Ambient Air Quality Standard in 1997. Much of this debate revolves around claims that particulate matter (usually represented by PM10) in the atmosphere directly influences mortality, hospital admissions with respiratory diseases, and so on. In this paper, we take a critical look at one of these issues, the influence of PM10 on deaths in the elderly population. Two data sets are considered, one from Birmingham (Alabama) and the other from Chicago. In both cases we find a significant PM10-mortality relationship in some of the models fitted, but not in others. Other issues considered include the existence of a threshold below which PM10 has no discernible influence, the interaction with other pollutants and the mortality displacement or harvesting effect (the theory that the direct effect of PM10 is limited to a very small subset of the population who are already critically ill and whose death is only advanced by a few hours or days as a result of air pollution). Overall, our conclusion is that there are too many uncertain issues to allow us to make definitive statements about a causal relationship between PM10 and mortality.
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Nakashima Y, Sun DH, Trindade MC, Maloney WJ, Goodman SB, Schurman DJ, Smith RL. Signaling pathways for tumor necrosis factor-alpha and interleukin-6 expression in human macrophages exposed to titanium-alloy particulate debris in vitro. J Bone Joint Surg Am 1999; 81:603-15. [PMID: 10360689 DOI: 10.2106/00004623-199905000-00002] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Loosening of the implant after total joint arthroplasty remains a serious problem. The activation of macrophages by wear debris from implants, mediated by the release of cytokines that elicit bone resorption, may lead to loosening. The purpose of the present study was to elucidate the mechanisms of macrophage activation by titanium particles from the components of implants and to identify the signaling pathways involved in particle-mediated release of cytokines. METHODS Macrophages were isolated from mononuclear leukocytes obtained from healthy human donors and were exposed to titanium-alloy particles that had been obtained from periprosthetic membranes collected at revision total joint arthroplasties and then enzymatically prepared. The experimental protocols included examination of the effects of the inhibition of phagocytosis and the binding of antibodies to macrophage complement receptors on particle-induced macrophage activation. The release of the proinflammatory cytokines TNF-alpha (tumor necrosis factor-alpha) and IL-6 (interleukin-6) was used to assess macrophage activation. The signaling pathways involved in the induction of cytokine release were analyzed by identification of phosphorylated proteins with use of the Western blot technique and by translocation of the transcription factors nuclear factor-kappa B (NF-kappaB) and nuclear factor-interleukin-6 (NF-IL-6) into the nuclear protein fraction with use of electrophoretic mobility shift assays. The role of serine/threonine and tyrosine kinase pathways in the activation of nuclear factors and the release of cytokines was examined with use of selective pharmacological agents. RESULTS Exposure of macrophages to titanium-alloy particles in vitro for forty-eight hours resulted in a fortyfold increase in the release of TNF-alpha and a sevenfold increase in the release of IL-6 (p<0.01). Phagocytosis of particles occurred in approximately 73 percent of the macrophages within one hour of exposure. Pretreatment of the macrophages with cytochalasin B reduced phagocytosis by 95 percent but did not reduce the release of TNF-alpha or IL-6. Thus, phagocytosis of particles was not necessary for induction of the release of TNF-alpha or IL-6 in the cultured macrophages. Ligation of the macrophage CD11b/CD18 receptors by integrin-specific antibodies also increased the release of TNF-alpha and IL-6. Antibodies to CD11b/ CD18 receptors (macrophage Mac-1 receptors) reduced phagocytosis of particles by 50 percent (p<0.05). (The CD11b/CD18 macrophage receptor is the macrophage receptor for the complement component CR3bi. The CD11b/CD18 macrophage receptor can also bind to ICAM-1 and ICAM-2. CD is the abbreviation for cluster of differentiation, and ICAM is the abbreviation for intercellular adhesion molecule.) Inhibition of phagocytosis was not accompanied by a decrease in the release of TNF-alpha and IL-6. Blocking RNA synthesis with actinomycin D or preventing protein synthesis with cycloheximide abolished or decreased particle-induced release of TNF-alpha and IL-6 from the macrophages. Macrophage release of TNF-alpha and IL-6 in response to particles coincided with increased tyrosine phosphorylation and mitogen-activated protein kinase activation. Inhibition of tyrosine and serine/threonine kinase activity decreased the particle-induced release of cytokines. Exposure of macrophages to either titanium-alloy particles or to antibodies to the receptor proteins CD11b and CD18 for thirty minutes activated the transcription factors NF-kappaB and NF-IL-6. Inhibition of particle phagocytosis did not block activation of the transcription factors. However, inhibition of tyrosine and serine/threonine kinase activity decreased the activation of NF-kappaB and NF-IL-6. CONCLUSIONS These data suggest that particle induced macrophage release of TNF-alpha and IL-6 does not require phagocytosis but is dependent on tyrosine and serine/threonine kinase activity culminating in activation of
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Abstract
An increased urinary excretion of trimethylamine and its N-oxide were observed in man following the oral intake (15 mmol) of choline (63% dose as trimethylamine and its N-oxide), D,L-carnitine (31% dose) and trimethylamine N-oxide (78% dose). Similar ingestion of betaine, creatinine or lecithin failed to elicit any significant increases. Of 46 different foods investigated, only fish and other sea-products gave rise to significant increases in urinary trimethylamine and N-oxide. Ingestion of fruits, vegetables, cereal and dairy produce, and meats had no measurable effects. Reasons for the apparent lack of trimethylamine provision by foods previously thought to be precursors are given and the role of gut microflora highlighted.
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O'Connor SE, Pearce J, Smith RL, Vogeli D, Walton P. Monitoring the quality of pre-registration education: development, validation and piloting of competency based performance indicators for newly qualified nurses. NURSE EDUCATION TODAY 1999; 19:334-341. [PMID: 10595070 DOI: 10.1054/nedt.1999.0645] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The clinical competence or 'fitness for purpose' of newly qualified nurses continues to be an important professional and corporate issue that as yet has no objective means of assessment. A mixed group of managers, clinicians and educationalists was commissioned to develop a method for the measurement and evaluation of performance during the first year of employment of newly qualified nurses. Two instruments were developed and the results of the initial pilot study are demonstrated in this article. The results are preceded by a review of the relevant literature. The initial pilot study results indicate that in the case of both instruments the tests designed do give clear results on the small numbers used. A complete picture of the validity of the audit tool will not be seen until the results of the full validation study, including the above exercise, are known. However, the results to date indicate that the instruments have the potential to demonstrate the clinical competency of newly qualified staff on employment in their first post and their development over the first year of employment.
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171
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Lamb FS, Clayton GH, Liu BX, Smith RL, Barna TJ, Schutte BC. Expression of CLCN voltage-gated chloride channel genes in human blood vessels. J Mol Cell Cardiol 1999; 31:657-66. [PMID: 10198195 DOI: 10.1006/jmcc.1998.0901] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chloride (Cl) ion channels play a critical role in the response of both vascular smooth muscle (VSM) and endothelial (ENDO) cells to agonist stimulation. In VSM, agonist-induced Cl currents produce membrane depolarization, resulting in calcium influx through voltage-sensitive channels. ENDO cells also activate Cl currents after either agonist application or perturbation of cell volume. Although some of these currents have been characterized biophysically, the genes involved have not been identified. The CLCN family of voltage-dependent Cl channel genes comprises nine members (CLCN1-7, Ka and Kb) which demonstrate quite diverse functional characteristics while sharing significant sequence homology. We used Northern-blot analysis to study the expression of these Cl channel genes in cultured human aortic and coronary VSM cells and in aortic ENDO cells. CLCN3 is by far the most abundant CLC channel mRNA in both VSM and ENDO cells. Lower levels of expression are seen for CLCN2, CLCN4, CLCN5 and CLCN6. Expression levels were similar in VSM and ENDO cells except for CLCN4 which was more highly expressed in ENDO cells. In situ hybridization was used to confirm the expression of CLCN3 in intact human fetal lung. CLCN3 message was seen in VSM and ENDO cells of both large and small pulmonary vessels, indicating that their detection by Northern blotting was not an artifact of cell culture. CLCN3 is also expressed in pulmonary epithelial and bronchial smooth muscle cells but not in chondrocytes or pulmonary interstitial cells. Recent studies suggest that CLCN3 may encode the swelling-induced Cl conductance. We used whole cell patch clamp recording to demonstrate swelling-induced Cl currents in these cultured VSM cells. This suggests that the CLCN3 protein is expressed; however, the functional role of this current in VSM remains to be determined.
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172
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Moorhead JW, Clayton GH, Smith RL, Schaack J. A replication-incompetent adenovirus vector with the preterminal protein gene deleted efficiently transduces mouse ears. J Virol 1999; 73:1046-53. [PMID: 9882305 PMCID: PMC103924 DOI: 10.1128/jvi.73.2.1046-1053.1999] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/1998] [Accepted: 10/20/1998] [Indexed: 11/20/2022] Open
Abstract
Adenoviruses offer great potential as gene therapy agents but are limited by the strong inflammatory response that occurs in response to the recombinant virus. Since the degree of inflammation correlates in part with the potential of the viral vector for replication, we constructed a preterminal protein (pTP) deletion mutant adenovirus type 5 vector, Ad5dl308DeltapTPbeta-gal, that is replication incompetent due to deletion of the pTP gene and that has the E1 genes replaced by the Escherichia coli lacZ reporter gene under the control of the cytomegalovirus major immediate-early promoter. This virus was compared with a first-generation, replication-defective adenovirus vector, Ad5dl308beta-gal, that is isogenic except that it contains a wild-type pTP gene. To examine transduction efficiency and induction of inflammation, we developed a novel system involving intradermal injection of BALB/c mouse ears. Mouse ears can be accurately measured to determine the degree of edema as an indirect measurement of inflammation. Edema and inflammation were induced in a dose- and time-dependent manner by both viruses and correlated well. LacZ activity correlated inversely with edema and inflammation. The pTP-defective vector Ad5dl308DeltapTPbeta-gal transduced mouse ears much more efficiently and induced edema and inflammatory cell infiltration approximately 10-fold less efficiently than the first-generation vector Ad5dl308beta-gal. The diminished inflammatory response and increased efficiency of transduction observed with Ad5dl308DeltapTPbeta-gal indicate its promise as a gene therapy agent for other tissues. The results also demonstrate that the mouse ear model offers potential for the study of adenovirus-induced inflammation because of the ready access of the ears, the relative ease of continuous measurement, and the sensitivity to adenovirus transducing vectors.
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MESH Headings
- Adenoviruses, Human/genetics
- Adenoviruses, Human/immunology
- Adenoviruses, Human/physiology
- Animals
- Cell Line, Transformed
- Cell Transformation, Viral
- Defective Viruses/genetics
- Defective Viruses/physiology
- Ear/virology
- Female
- Gene Deletion
- Gene Expression
- Genes, Reporter
- Genetic Vectors/genetics
- Genetic Vectors/immunology
- Genetic Vectors/physiology
- Humans
- Injections, Intradermal
- Mice
- Mice, Inbred BALB C
- Models, Biological
- Phosphoproteins/genetics
- Phosphoproteins/immunology
- Protein Precursors/genetics
- Protein Precursors/immunology
- Transformation, Genetic
- Viral Proteins/genetics
- Viral Proteins/immunology
- Virus Replication
- beta-Galactosidase/genetics
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173
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Smith TL, Walz BJ, Smith RL. A death education curriculum for emergency physicians, paramedics, and other emergency personnel. PREHOSP EMERG CARE 1999; 3:37-41. [PMID: 9921739 DOI: 10.1080/10903129908958904] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Although death education is a standard component in most medical schools and nursing programs, few include instruction on dealing with sudden death. Typically, death education courses overlook instruction in areas germane to emergency medicine, e.g., making death notifications, interacting with survivors during the immediate grief period, and reducing professional stress innate to working with newly bereaved persons. This curriculum was developed to address the paucity of existing death education materials for emergency professionals. Topics include death perspectives and awareness, death typology, cultural and religious considerations, communicating with bereaved persons, making death notifications, and dealing with initial grief reactions. Units of instruction are outlined, including educational goals, descriptions of units, teaching strategies, and supplemental readings.
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174
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Nakashima Y, Sun DH, Trindade MC, Chun LE, Song Y, Goodman SB, Schurman DJ, Maloney WJ, Smith RL. Induction of macrophage C-C chemokine expression by titanium alloy and bone cement particles. THE JOURNAL OF BONE AND JOINT SURGERY. BRITISH VOLUME 1999; 81:155-62. [PMID: 10068024 DOI: 10.1302/0301-620x.81b1.8884] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Particulate wear debris is associated with periprosthetic inflammation and loosening in total joint arthroplasty. We tested the effects of titanium alloy (Ti-alloy) and PMMA particles on monocyte/macrophage expression of the C-C chemokines, monocyte chemoattractant protein-1 (MCP-1), monocyte inflammatory protein-1 alpha (MIP-1alpha), and regulated upon activation normal T expressed and secreted protein (RANTES). Periprosthetic granulomatous tissue was analysed for expression of macrophage chemokines by immunohistochemistry. Chemokine expression in human monocytes/macrophages exposed to Ti-alloy and PMMA particles in vitro was determined by RT-PCR, ELISA and monocyte migration. We observed MCP-1 and MIP-1alpha expression in all tissue samples from failed arthroplasties. Ti-alloy and PMMA particles increased expression of MCP-1 and MIP-1alpha in macrophages in vitro in a dose- and time-dependent manner whereas RANTES was not detected. mRNA signal levels for MCP-1 and MIP-1alpha were also observed in cells after exposure to particles. Monocyte migration was stimulated by culture medium collected from macrophages exposed to Ti-alloy and PMMA particles. Antibodies to MCP-1 and MIP-1alpha inhibited chemotactic activity of the culture medium samples. Release of C-C chemokines by macrophages in response to wear particles may contribute to chronic inflammation at the bone-implant interface in total joint arthroplasty.
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175
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Wigley TML, Smith RL, Santer BD. Anthropogenic influence on the autocorrelation structure of hemispheric-mean temperatures. Science 1998; 282:1676-9. [PMID: 9831552 DOI: 10.1126/science.282.5394.1676] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
It is shown that lagged correlations for and cross-correlations between observed hemispheric-mean temperature data differ markedly from those for unforced (control-run) climate model simulations. The differences can be explained adequately by assuming that the observed data contain a significant externally forced component involving both natural (solar) and anthropogenic influences and that the global climate sensitivity is in the commonly accepted range. Solar forcing alone cannot reconcile the differences in autocorrelation structure between observations and model control-run data.
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