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Slomka J, Agich GJ, Stagno SJ, Smith ML. Physical restraint elimination in the acute care setting: ethical considerations. HEC Forum 1998; 10:244-62. [PMID: 10338978 DOI: 10.1023/a:1008844314555] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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352
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Smith ML, Evans GR, Gürlek A, Bouvet M, Singletary SE, Ames FC, Janjan N, McNeese MD. Reduction mammaplasty: its role in breast conservation surgery for early-stage breast cancer. Ann Plast Surg 1998; 41:234-9. [PMID: 9746077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Segmental resection and radiotherapy is an accepted alternative over mastectomy for small, staged breast malignancies. However, women with large, pendulous breasts have been documented to have poorer cosmetic outcomes when undergoing irradiation after breast conservative surgery compared with women with small- or medium-size breasts, thought to be caused by dose inhomogeneity. The purpose of this study was to evaluate the efficacy of combining reduction mammaplasty with breast conservative surgery to facilitate postoperative irradiation. Between 1988 and 1996, 10 women have undergone bilateral reduction mammaplasty for breast malignancy followed by radiation therapy at our center. All women wished to avoid mastectomy (average age, 59 years). All lesions were detected preoperatively on mammography. The average amount of tissue removed was 945 g per breast. A variety of reduction techniques were employed to include the malignant lesions. All patients received 50 Gy of radiation therapy delivered in 25 fractions following reduction mammaplasty during a 5-week period. Radiation therapy was usually initiated within 4 weeks following surgery. Follow-up is currently 37 months, with all patients being followed for at least 8 months. No patients have had complications from the surgery or radiation therapy. No local recurrent malignancies have been detected. Cosmesis has been good to excellent in all patients. Despite equivalent survival outcomes for mastectomy for early-stage breast cancer, certain women are not good candidates for breast conservation and radiation therapy. An alternative for women with large, pendulous breasts that combines breast conservation therapy and concurrent bilateral reduction mammaplasty should be considered. This combination, in selected women, provides good functional and cosmetic results, and at the same time minimizes the potential difficulties of radiation therapy.
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353
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Li PA, Gisselsson L, Keuker J, Vogel J, Smith ML, Kuschinsky W, Siesjö BK. Hyperglycemia-exaggerated ischemic brain damage following 30 min of middle cerebral artery occlusion is not due to capillary obstruction. Brain Res 1998; 804:36-44. [PMID: 9729262 DOI: 10.1016/s0006-8993(98)00651-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transient focal ischemia of brief duration (15-30 min) gives rise to brain damage. In normoglycemic animals this damage usually consists of selective neuronal necrosis (SNN), and is largely confined to the lateral caudoputamen. In hyperglycemic subjects damage occurs more rapidly, involves also neocortical areas, and is often of the pan-necrotic type ('infarction'). Since experiments on forebrain ischemia of 30 min duration suggest that microcirculatory compromise develops during recirculation, we studied whether focal ischemia of the same duration, followed by reperfusion for 1, 2 or 4 h, leads to microcirculatory dysfunction. To test this possibility, we fixed the tissue by perfusion and counted the number of formed elements (leukocytes, macrophages and erythrocytes) in capillaries and postcapillary venules. Furthermore, capillary patency was evaluated following in vivo injection of Evan's blue. Histopathological examination of tissue fixed by perfusion after 1, 2 and 4 h of recirculation showed an increasing density of SNN in the caudoputamen of normoglycemic animals. Hyperglycemic, but not normoglycemic, animals showed pan-necrotic lesions ('infarction') after 4 h of recirculation. As a result, the total volume of tissue damage (SNN plus infarction) was larger in hyper- than in normoglycemic animals at 2 and 4 h of recirculation. In addition, hyperglycemic animals showed involvement of neocortex which increased with the time of reperfusion. In the ischemic hemisphere, between 5 and 10% of counted capillaries contained formed elements. However, since hyperglycemic animals contained an equal (or smaller) amount of cells the results did not suggest that capillary 'plugging' could explain the aggravated damage. Moreover, both normo- and hyperglycemic animals showed close to 100% capillary patency. The results thus fail to support the notion that the aggravation of focal ischemic damage by hyperglycemia is due to obstruction of microvessel by swelling or leukocyte adherence.
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354
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Smith ML, Bortnick RA, Sheikh MS, Fornace AJ. Chromatin relaxation by overexpression of mutant p53, HPV16-E6, or cyclin G transgenes. Exp Cell Res 1998; 242:235-43. [PMID: 9665821 DOI: 10.1006/excr.1998.4078] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In this study, using a cell line that carries endogenous wild-type p53 genes, we show that transfection of cells with mutant p53, HPV16-E6, or cyclin G transgenes results in the disruption of higher-order chromatin structure, as evidenced by enhanced sensitivity to micrococcal nuclease. Multiple mechanisms may contribute to this phenotype, including histone H1 phosphorylation, direct binding of oncoproteins to nuclear matrix attachment sites, and altered expression of component genes of the p53 pathway, whose products may function in maintenance of chromatin structure.
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355
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Kunsman GW, Jones R, Levine B, Smith ML. Methylephedrine concentrations in blood and urine specimens. J Anal Toxicol 1998; 22:310-3. [PMID: 9681334 DOI: 10.1093/jat/22.4.310] [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: 11/14/2022] Open
Abstract
Methylephedrine is a sympathomimetic amine that appears in many over-the-counter cough and cold medications throughout the world. The abuse of methylephedrine-containing medications has been reported in Japan. Although methylephedrine is not available in the United States, it was identified in 15 cases received by the Forensic Toxicology Laboratory, Division of Forensic Toxicology, Office of the Armed Forces Medical Examiner, Armed Forces Institute of Pathology over a two-year period; 12 of the 15 cases were collected from patients or decedents located within the confines of the continental United States. Methylephedrine was identified in each case by gas chromatography-nitrogen-phosphorus detection following an alkaline extraction and subsequently confirmed using full scan electron impact mass spectrometry. Quantitation of underivatized methylephedrine was performed using the same technique. Blood methylephedrine concentrations ranged from less than 0.05 to 0.28 mg/L (n = 14), and the mean methylephedrine concentration in urine was 1.6 mg/L (range, 0.15-6.8, n = 11 [excluding case 6]). A literature search revealed little information pertaining to the interpretation of methylephedrine concentrations in the blood. Six of the 15 cases presented here were positive for methylephedrine in the blood. Three of these cases were postmortem cases, and the other three cases were nonfatal aircraft mishaps. There is no evidence in any of these cases that methylephedrine was present at toxic concentrations; therefore, it appears from the cases reviewed in this study that blood methylephedrine concentrations less than 0.3 mg/L are not associated with significant toxicity.
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356
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Watenpaugh DE, Smith ML. Human cardiovascular acclimation to microgravity. JOURNAL OF GRAVITATIONAL PHYSIOLOGY : A JOURNAL OF THE INTERNATIONAL SOCIETY FOR GRAVITATIONAL PHYSIOLOGY 1998; 5:P15-8. [PMID: 11542332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
This brief review provides an update on recent studies of human cardiovascular responses to spaceflight. This report complements prior reviews of the acute responses and chronic acclimation of the cardiovascular system to actual and simulated microgravity.
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357
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Honaker CJ, Sprayberry NK, Smith ML. Better training for less money--from outer space. CARING : NATIONAL ASSOCIATION FOR HOME CARE MAGAZINE 1998; 17:50-2. [PMID: 10181307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Agencies that wish to develop innovative, interactive and entertaining inservices for their employees may want to look at the Alabama Department of Public Health's program, which has developed cost-effective inservice training for more than 6,000 employees working at 120 sites across the state. It works by using satellite technology--rocket science to bring the caring touch closer to home.
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358
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Gisselsson L, Smith ML, Siesjö BK. Influence of hypoglycemic coma on brain water and osmolality. Exp Brain Res 1998; 120:461-9. [PMID: 9655231 DOI: 10.1007/s002210050419] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To study the effects of pronounced hypoglycemia on brain osmolality and brain edema formation, fasted rats were rendered hypoglycemic by injection of insulin, and subjected to 30 min of hypoglycemic coma. Recovery was accomplished by glucose administration. The change in water content in different brain regions was measured as a change in specific gravity after 30 min of hypoglycemic coma, or 30, 60, and 180 min after glucose administration. Plasma and brain tissue osmolality were measured in separate animals. The results show a significant decrease in specific gravity (increase in water content) in all structures measured (caudoputamen, neocortex, hippocampus, and cerebellum) at the end of the period of coma, as well as after 30 min and 60 min of recovery. At 180 min of recovery, brain water was normalized. The edema affected all structures to the same degree regardless of their vulnerability to hypoglycemic damage. Brain tissue osmolality showed a tendency to decrease with decreasing tissue glucose content. The decrease was significant (P<0.01) at 30 min of isoelectric coma. In the recovery phase, normal brain osmolality was restored within 30 min. Measurements of blood-brain barrier (BBB) permeability after 30 min of hypoglycemic coma showed no extravasation of Evan's blue, though a small but significant increase in the permeability for aminoisobutyric acid (AIB) in caudoputamen and in cerebellum was found. To analyze the importance of tissue acidosis for formation of edema, hypoglycemic animals were made acidotic by increasing the CO2 concentration in inspired air to produce an arterial plasma pH of 6.8-6.9. In these animals the edema was of a similar degree to the normocapnic animals, and the permeability for AIB was normal. We conclude that osmolytic mechanisms are not the primary cause of the selective neuronal vulnerability in hypoglycemic coma. Furthermore, the BBB is largely intact during a hypoglycemic insult.
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Abstract
Scaly scalp is a common problem in the pediatric and adolescent population. The possible causes range from the commonly seen tinea capitis and seborrheic dermatitis to rare systemic diseases such as dermatomyositis and Letterer-Siwe disease. In all cases a thorough history and physical examination are important first steps to successful diagnosis and treatment.
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360
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Smith ML, Hanley WB, Clarke JT, Klim P, Schoonheyt W, Austin V, Lehotay DC. Randomised controlled trial of tyrosine supplementation on neuropsychological performance in phenylketonuria. Arch Dis Child 1998; 78:116-21. [PMID: 9579151 PMCID: PMC1717450 DOI: 10.1136/adc.78.2.116] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To test the efficacy of tyrosine supplementation, as an adjunct to dietary treatment, on neuropsychological test performance in individuals with phenylketonuria. DESIGN A randomised controlled trial of tyrosine supplementation using a double blind crossover procedure with three four week phases. SETTING The Hospital for Sick Children, Toronto. PARTICIPANTS 21 individuals with phenylketonuria (ages 6 to 28 years, mean 11.3). INTERVENTION Participants were given 100 mg/kg body weight/d of L-tyrosine or L-alanine (placebo). RESULTS At baseline, performance on several of the neuropsychological test measures was correlated with tyrosine levels. Dietary supplements of tyrosine increased plasma tyrosine concentrations; however, no change in test performance was found across the tyrosine and placebo phases of the study. CONCLUSIONS Tyrosine supplementation of this type does not appear to alter neuropsychological performance in individuals with phenylketonuria.
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362
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Li PA, Vogel J, He QP, Smith ML, Kuschinsky W, Siesjö BK. Preischemic hyperglycemia leads to rapidly developing brain damage with no change in capillary patency. Brain Res 1998; 782:175-83. [PMID: 9519261 DOI: 10.1016/s0006-8993(97)01150-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The present experiments were undertaken to explore whether exaggeration of ischemic brain damage by preischemic hyperglycemia is due to lack of capillary patency in the postischemic period. Normo- and hyperglycemic rats were exposed to 10 min of forebrain ischemia. Histopathological changes were evaluated after 6 and 16-18 h of recovery by light microscopy, and capillary patency was assessed at the same time points by a double-staining technique, depicting perfused and morphologically identifiable capillaries. The results demonstrate that some neuronal damage was detectable after 6 h of recirculation which was aggravated after 16-18 h of recirculation in hyperglycemic rats. In contrast, the degree of capillary patency was similar in normo- and hyperglycemic rats. In both groups the perfusion marker, Evans blue, perfused about 95% of all capillaries when injected 10 s before decapitation. Since preischemic hyperglycemia exaggerates brain damage without cessation of capillary perfusion the primary targets of hyperglycemic brain damage may not be capillaries but neurons or glial cells.
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363
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Smith ML, Stagno SJ, Dolske M, Kosalko J, McConnell C, Kaspar L, Lederman R. Induction procedures for psychogenic seizures: ethical and clinical considerations. THE JOURNAL OF CLINICAL ETHICS 1998; 8:217-29. [PMID: 9436080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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364
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Moskop JC, Smith ML, De Ville K. Ethical and legal aspects of teratogenic medications: the case of isotretinoin. THE JOURNAL OF CLINICAL ETHICS 1998; 8:264-78. [PMID: 9436085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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365
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Smith ML, Fornace AJ. Correspondence re: J. S. DeFrank et al., p53-null cells are more sensitive to ultraviolet light only in the presence of caffeine. Cancer Res., 56: 5365-5368, 1996. Cancer Res 1997; 57:5434-6. [PMID: 9393772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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366
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Smith ML, Fornace AJ. p53-mediated protective responses to UV irradiation. Proc Natl Acad Sci U S A 1997; 94:12255-7. [PMID: 9356435 PMCID: PMC33783 DOI: 10.1073/pnas.94.23.12255] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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367
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Stagno SJ, Smith ML. The use of placebo in diagnosing psychogenic seizures: who is being deceived? Semin Neurol 1997; 17:213-8. [PMID: 9311062 DOI: 10.1055/s-2008-1040931] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Induction procedures have been employed by some neurologists as a method of attempting to determine whether paroxysmal events experienced by the patient are psychogenic in origin. Although various techniques are used, those involving injection of intravenous saline and placebo patches are the focus of this article because they involve deception of the patient and raise the greatest ethical concerns. Issues of potential harm to the patient are examined in light of the typical psychological profile of patients who have psychogenic seizures. In addition, reliability of the procedure, possible benefit to the patient, and alternatives to using the procedure are considered. Finally, the question of whether there is ethical justification to consider induction procedures as an acceptable exception to informed consent is discussed. The authors argue that there is little if any justification for using induction procedures involving placebos, and that when the procedure is considered justifiable it should be done only if examination by a mental health professional discloses no psychological contraindications to proceeding and if a debriefing of the patient explaining the process and purpose of the induction is to take place following the procedure.
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368
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Tsuchidate R, He QP, Smith ML, Siesjö BK. Regional cerebral blood flow during and after 2 hours of middle cerebral artery occlusion in the rat. J Cereb Blood Flow Metab 1997; 17:1066-73. [PMID: 9346431 DOI: 10.1097/00004647-199710000-00008] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this study we explored if the secondary bioenergetic failure, which occurs a few hours after recirculation, following transient middle cerebral artery occlusion (MCAO) in rats, is caused by a compromised reflow. We induced 2 hours of MCAO and measured CBF at the end of the ischemia, as well as 15 minutes, 1, 2, and 4 hours after the start of recirculation, using autoradiographic or tissue sampling 14C-iodoantipyrine techniques. After 2 hours of MCAO, the autoradiographically measured CBF in the ischemic core areas was reduced to 3 to 5% of contralateral values. The reduction in CBF was less in neighboring, penumbral areas. After recirculation, flow already normalized in core tissues after 15 minutes, and remained close to normal for the 4 hours recirculation period studied. However, in penumbral tissues, recovery CBF values were usually below normal. The results show that tissues that are heavily compromised by the 2-hour period of ischemia and are destined to incur infarction, show a "relative hyperemia" during recirculation. In fact, some areas of the previously densely ischemic tissue showed overt hyperperfusion. This finding raises the question whether the relative or absolute hyperemia reflects events that are pathogenetically important. Because drugs that clearly ameliorate the final damage incurred fail to alter the relative hyperperfusion of previously ischemic tissues, it is concluded that vascular events in the reperfusion period do not play a major role in causing the final damage.
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369
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Abstract
When Jehovah's Witnesses refuse blood, they regularly ask their physicians to explore and provide all other medically and scientifically based alternatives, even when these alternatives may not be as effective and may carry risk of failure that could lead to physical disabilities or death. An awareness of the values at stake and of other cases from personal experience and the literature can help physicians, patients, and their families to move toward ethically responsible decisions and actions.
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370
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Kunsman GW, Levine B, Costantino A, Smith ML. Phencyclidine blood concentrations in DRE cases. J Anal Toxicol 1997; 21:498-502. [PMID: 9323532 DOI: 10.1093/jat/21.6.498] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Phencyclidine (PCP) concentration was measured in blood obtained from 259 individuals over a two-year period subsequent to Drug Recognition Expert (DRE) evaluation by the Maryland State Police. The purpose of this study was to evaluate the accuracy of the DRE in the identification of PCP-related impairment using the presence of PCP in blood to confirm drug use and to test for a correlation between PCP concentrations in blood and impairment as indicated by DRE evaluation. Of the 259 cases evaluated, 124 were identified as positive for PCP based on DRE evaluation, 130 were positive for PCP based on toxicological analysis, and 56 of the 124 were identified as positive for PCP only by DRE and subsequently confirmed to contain only PCP. The mean PCP concentration for those cases in which only PCP was identified by both DRE and toxicology was 51 ng/ml (standard deviation, 26 ng/mL) with a range of values of 12-118 ng/mL. Although no correlation was determined between PCP concentration and behavior, it is clear that, even at concentrations as low as 12 ng/mL, PCP-induced behavioral effects are measurable by DRE evaluation. This study also revealed that despite a low false-positive rate (3%) of detection of PCP use by the DRE, the false-negative rate of 8% supports the conclusion that the toxicological analysis of blood specimens for PCP provides the necessary, objective corroboration of the DRE's opinion concerning impairment.
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371
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Smith ML, Hua XY, Marsden DL, Liu D, Kennaway NG, Ngo KY, Haas RH. Diabetes and mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS): radiolabeled polymerase chain reaction is necessary for accurate detection of low percentages of mutation. J Clin Endocrinol Metab 1997; 82:2826-31. [PMID: 9284704 DOI: 10.1210/jcem.82.9.4222] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A 6-yr-old boy presented with muscle weakness, lactic acidemia, and insulin-dependent diabetes mellitus (IDDM). Using PCR and restriction enzyme analysis, he was found to have the classical A3248G mitochondrial DNA (mtDNA) mutation frequently associated with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). The mutation was confirmed by sequencing muscle mtDNA. The mutation in mtDNA from muscle, lymphoblasts, and blood was clearly demonstrable by standard methods using ethidium bromide staining. His mother also had IDDM, but no A3243G mutation could be detected in her blood or transformed lymphoblasts using the same PCR technique. When PCR was carried out in the presence of [32P]deoxycytidine triphosphate, subsequent autoradiography detected the presence of the mutation at low levels in mtDNA from the mother's lymphoblasts and blood. Study of the mother's muscle showed a mitochondrial myopathy, despite the fact that she was asymptomatic. We emphasize that the increased sensitivity of radiolabeled PCR may be necessary to detect small percentages of heteroplasmic A3243G mtDNA mutation in blood from diabetic subjects. Otherwise the incidence of mtDNA mutations in both IDDM and non-insulin dependent diabetes may be underestimated.
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372
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Moskop JC, Smith ML, De Ville K. Ethical and Legal Aspects of Teratogenic Medications: The Case of Isotretinoin. THE JOURNAL OF CLINICAL ETHICS 1997. [DOI: 10.1086/jce199708307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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373
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McIntosh DG, Colcher D, Seemayer T, Smith ML. The intraoperative detection of ovarian adenocarcinoma using radiolabeled CC49 monoclonal antibody and a hand-held gamma-detecting probe. Cancer Biother Radiopharm 1997; 12:287-94. [PMID: 10851478 DOI: 10.1089/cbr.1997.12.287] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A phase II study to evaluate the safety and efficacy of the 125I-radiolabeled anti-TAG-72 monoclonal antibody, CC49, as a component of a system for the intraoperative detection of occult ovarian cancer deposits was carried out at the University of Nebraska Medical Center. Patients entered into the study were to have surgery for evaluation of their disease status. The primary objective of this study was to determine the ability of a gamma-detecting probe (GDP), the Neoprobe 1000, to intraopertively localize sites of disease not identified by traditional surgical or radiographic evaluation. It was postulated that improved detection of cancer foci might allow for therapeutic excision or might result in an alteration of subsequent treatment. Ten patients were enrolled in the study between May 1993 and March 1994. Nine of the patients were undergoing second-look surgery after completing primary chemotherapy. The remaining patient was having surgery to assess possible cancer recurrence. All patients received an intravenous injection of 2 mCi/1 mg 125I-radiolabeled CC49 without complication. After a mean of 24.5 days, the patients' background radiation counts were deemed low enough for accurate intraoperative cancer localization, and surgery was performed. Any visibly or palpably abnormal areas were biopsied after being evaluated with the GDP. Any areas suspicious for malignancy by GDP evaluation were also biopsied. Two patients without evident disease by radiographic or surgical examination had histologically confirmed metastases localized by the GDP. Four patients had obvious disease at surgery which was variably confirmed by the GDP; two of these patients had baseline elevations in circulating TAG-72 antigen levels that may have affected binding of antibody to the tumor. This system of radioimmunoguided surgery was well tolerated and practical in its application, and it permitted disease detection that resulted in potentially beneficial changes in patient management.
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374
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Bertrand PP, Kunze WA, Bornstein JC, Furness JB, Smith ML. Analysis of the responses of myenteric neurons in the small intestine to chemical stimulation of the mucosa. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:G422-35. [PMID: 9277422 DOI: 10.1152/ajpgi.1997.273.2.g422] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Responses of myenteric AH and S neurons to local application of chemicals to the mucosa of the guinea pig small intestine were obtained using conventional intracellular recording techniques. Preparations were dissected to reveal the myenteric plexus over one-half of the circumference of the gut with intact mucosa on the the half. Neurons were impaled within the exposed one-half, whereas potential stimulants, in buffered saline, were transiently applied to the mucosa, 1-1.5 mm circumferential from the impalement. The stimulants elicited action potentials (AP) in AH neurons that did not arise from synaptic activity. AH neurons also responded with slow excitatory postsynaptic potentials (EPSP). S neurons were activated synaptically, via fast and slow EPSP, but not nonsynaptically. Mucosal application of solutions of a low pH (3-5) or a high pH (9-11) were both effective stimulants. Solutions of a neutral pH, which was also a control for mild mechanical stimulation, were usually ineffective. Both a short-chain fatty acid, acetate (pH 7.2), and 5-hydroxytryptamine elicited responses in each neuronal type. We conclude that myenteric AH neurons of the guinea pig distal ileum are primary afferent neurons that respond to a variety of mucosally applied chemical stimuli with burst of AP. In addition, the physiologically evoked transmission of slow EPSP to AH neurons suggests that primary afferent neurons interconnect in a self-reinforcing network. S neurons are second or higher order neurons in the reflex pathways.
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375
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Albayrak S, Zhao Q, Siesjö BK, Smith ML. Effect of transient focal ischemia on blood-brain barrier permeability in the rat: correlation to cell injury. Acta Neuropathol 1997; 94:158-63. [PMID: 9255391 DOI: 10.1007/s004010050688] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Prolonged ischemia is known to damage the blood-brain barrier, causing an increase in vascular permeability to proteins. We studied the time course of extravasation of endogenous albumin in rats after 1 and 2 h of middle cerebral artery (MCA) occlusion followed by 6, 12, and 24 h of recirculation. In a separate group of rats that had undergone 1 h of MCA occlusion and 6 h of recirculation, influx of [14C]aminoisobutyric acid (AIB) from blood to brain was also measured. After 1 h of occlusion followed by 6 h of recirculation, neuronal damage was evident in caudoputamen, but there were no signs of blood-brain barrier leakage to either AIB or albumin. At 12 h, the caudoputamen contained extravasated albumin, and at 24 h extravasation was extended to the somatosensory cortex. Animals subjected to 2 h of MCA occlusion showed albumin extravasation in caudoputamen already at 6 h of recirculation, and at 12 and 24 h albumin was abundant in the major part of the right hemisphere. This study suggests that damage to neurons precedes leakage of the blood-brain barrier. Even a relatively short period of ischemia such as 1 h will result in markedly increased vascular permeability. However, a longer transient ischemic insult disrupts the blood-brain barrier earlier than a shorter one.
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