Biomedical subjects

M C Reid

Publications and source records attributed to M C Reid.

At least 19 recordsLinked to original sources

PubMed2006

Light to moderate alcohol consumption is associated with better cognitive function among older male veterans receiving primary care.

Among older persons, the effects of light to moderate alcohol consumption on cognitive function remain inadequately defined. The authors sought to determine whether light to moderate drinking is associated with better cognitive function among older men. Participants included men aged 65 years or older enrolled in a Veteran's Administration (VA) primary care clinic. Current (past 1 year) and lifetime use, cognitive functioning (as determined by the Trail Making Part B, Symbol Digit, FAS, and Hopkins Verbal Learning tests), and demographic, psychosocial, and medical status were obtained using standardized methods. Participants (N = 760) had a mean age of 74 (range, 65-89) years. Current drinkers (n = 509) as compared with never (n = 31) and former (n = 220) drinkers demonstrated significantly better cognitive performance on 3 (Trails B, Symbol Digit, and Hopkins Verbal Learning) of the 4 tests (P < .01 for all comparisons). In multiple linear regression models, current light to moderate drinking (ie, 7 or fewer drinks per week), as compared to a reference group of never and former drinkers, was associated with better performance on the Trails B, Symbol Digit, and Hopkins Verbal Learning tests (P < .01 for all comparisons). The number of years drinking 7 or fewer drinks per week also was independently associated with better cognitive performance. Current consumption of 7 or fewer drinks per week and the number of years drinking at this level are both associated with better cognitive performance in older male veterans receiving primary care. These findings are consistent with the hypothesis that light to moderate drinking confers cognitive benefits to older persons.

Aged↗

PubMed2005

Are commonly ordered lab tests useful screens for alcohol disorders in older male veterans receiving primary care&#63.

Although mean corpuscular volume (MCV), aspartate aminotransferase (AST), alanine aminotransferases (ALT), and the AST/ALT ratio are sometimes used as markers of alcohol disorders, their utility has not been established in older persons. We determined the tests' performance characteristics for (1) at-risk drinking, (2) CAGE positivity, (3) at-risk drinking and CAGE positivity, and (4) a clinician-recorded diagnosis of alcohol abuse/dependence in a study of older male veterans receiving primary care. Participants (n = 587) included patients who had MCV, AST, and/or ALT data collected as part of routine care no more than 12 weeks before or after enrollment. MCV, AST, and ALT test results were obtained from the VA's database. At enrollment, the Timeline Followback and Alcohol Use Disorders Identification Test (AUDIT) were used to identify at-risk drinkers (> or = 15 drinks per week or AUDIT score > or = 8), and the CAGE questionnaire was administered to identify participants with a history abuse/dependent drinking (CAGE score > or = 2). Participants' medical records were reviewed to identify subjects with a clinician-recorded diagnosis of alcohol abuse/dependence. The prevalence of abnormal test results for MCV (threshold value = > 98), AST (> 41), ALT (> 41), and the AST/ALT ratio (> 2) was 11%, 4%, 4%, and 5%, respectively. The occurrence of at-risk drinking, CAGE positivity, at-risk drinking and CAGE positivity, and a clinician-recorded diagnosis of alcohol abuse/dependence was 11%, 25%, 5%, and 9%, respectively. Test sensitivity ranged from 3.9% to 25.4% and specificity from 88.5% to 97.1%, whereas positive likelihood ratios varied from 0.72 to 4.01 and negative likelihood ratios from 0.82 to 1.04. Areas under the receiver operating characteristic curve were similar (range = 0.50-0.58) across tests. In conclusion, MCV, AST, ALT, and the AST/ALT ratio are not useful markers of alcohol disorders in older male veterans.

Aged↗

PubMed2001

Properties and substrate of slow pathway exposed with a compact node targeted fast pathway ablation in rabbit atrioventricular node.

INTRODUCTION: The properties and substrates of slow and fast AV nodal pathway remain unclear. This applies particularly to the slow pathway (SP), which is largely concealed by fast pathway (FP) conduction. We designed a new FP ablation approach that exposes the SP over the entire cycle length range and allows for its independent characterization and ablation. METHODS AND RESULTS: Premature stimulation was performed before and after FP ablation with 5.4 +/- 1.9 lesions (300-microm diameter each; overall lesion size 1.4 +/- 0.5 mm) targeting the junction between perinodal and compact node tissues in seven rabbit heart preparations. The resulting SP recovery curve and control curve had the same maximum nodal conduction time (165 +/- 22 msec vs 164 +/- 24 msec; P = NS) and effective refractory period (101 +/- 10 msec vs 100 +/- 9 msec; P = NS). The two curves covered the same cycle length range. However, the SP curve was shifted up with respect to control one at intermediate and long cycle lengths and thus showed a longer minimum nodal conduction time (81 +/- 15 msec vs 66 +/- 10 msec; P < 0.01) and functional refractory period (180 +/- 11 msec vs 170 +/- 12 msec; P < 0.05). The SP curve was continuous and closely fitted by a single exponential function. Small local lesions (2 +/- 1) applied to the posterior nodal extension resulted in third-degree nodal block in all preparations. CONCLUSION: The posterior nodal extension can sustain effective atrial-His conduction at all cycle lengths and account for both the manifest and concealed portion of SP. Slow and FP conduction primarily arise from the posterior extension and compact node, respectively.

Animals↗

PubMed2001

Exercise tolerance and quality of life in elderly patients with chronic atrial fibrillation.

BACKGROUND: Atrial fibrillation is the most common arrhythmia affecting the elderly. Although the risk of cardioembolic stroke is well defined, the effects of chronic atrial fibrillation on exercise tolerance and quality of life have been less well quantified. METHODS: We compared a group of 52 elderly patients with chronic atrial fibrillation to a group of 48 control patients in sinus rhythm. Each patient underwent an interview that incorporated the Short Form-36 Health Survey (SF-36) to quantify individual perceptions on quality of life. In addition each person underwent physiologic testing that included a Modified Bruce Protocol exercise tolerance test, 24-hour ambulatory monitor test, and an echocardiogram. RESULTS: Both groups were elderly, 77 vs 76 years of age (P=0.35). The two groups had similar ejection fractions, 55.4% vs 58.4% (P=0.10). The atrial fibrillation patients demonstrated a higher level of comorbidity based on the Charlson Comorbidity Index, 2.46 vs 1.57 (P=0.03). On formal exercise testing there was no statistical difference in exercise duration between the two groups 9.0 vs 10.1 minutes (P=0.24). Similarly the Physical Summary Score (PCS) and the Mental Summary Score (MCS) of the SF-36 quality of life survey did not demonstrate a statistical difference between the two groups. PCS: 43.0 vs 45.9 (P=0.24); MCS: 52.5 vs 55.7 (P=0.07). CONCLUSIONS: Despite a higher level of comorbidity, elderly, ambulatory patients with chronic atrial fibrillation demonstrate similar exercise tolerance and report similar quality of life to a group of age-matched control patients in sinus rhythm. There is a cohort of patients in chronic atrial fibrillation in whom a strategy of rate control and anticoagulation may be appropriate.

Aged↗

PubMed2000

Outpatient management of patients with alcohol problems.

This paper addresses the clinical presentation of patients with alcohol problems including screening, diagnosis, detoxification, treatment, referral, and longitudinal follow-up. The case-based discussion focuses on the clinical management of a patient whose hazardous drinking progresses to alcohol dependence and requires coordinated care. Ways in which internists can aid patients with alcohol problems by screening, giving brief advice, and providing appropriate referrals when indicated are discussed.

Alcohol Deterrents↗

PubMed2000

Screening for alcohol problems in primary care: a systematic review.

BACKGROUND: Primary care physicians can play a unique role in recognizing and treating patients with alcohol problems. OBJECTIVE: To evaluate the accuracy of screening methods for alcohol problems in primary care. METHODS: We performed a search of MEDLINE for years 1966 through 1998. We included studies that were in English, were performed in primary care, and reported the performance characteristics of screening methods for alcohol problems against a criterion standard. Two reviewers appraised all articles for methodological content and results. RESULTS: Thirty-eight studies were identified. Eleven screened for at-risk, hazardous, or harmful drinking; 27 screened for alcohol abuse and dependence. A variety of screening methods were evaluated. The Alcohol Use Disorders Identification Test (AUDIT) was most effective in identifying subjects with at-risk, hazardous, or harmful drinking (sensitivity, 51%-97%; specificity, 78%-96%), while the CAGE questions proved superior for detecting alcohol abuse and dependence (sensitivity, 43%-94%; specificity, 70%-97%). These 2 formal screening instruments consistently performed better than other methods, including quantity-frequency questions. The studies inconsistently adhered to methodological standards for diagnostic test research: 3 (8%) provided a full description of patient spectrum (demographics and comorbidity), 30 (79%) avoided workup bias, 12 (of 34 studies [35%]) avoided review bias, and 21 (55%) performed an analysis in pertinent clinical subgroups. CONCLUSIONS: Despite methodological limitations, the literature supports the use of formal screening instruments over other clinical measures to increase the recognition of alcohol problems in primary care. Future research in this field will benefit from increased adherence to methodological standards for diagnostic tests.

Adolescent↗

PubMed2000

New therapies for alcohol problems: application to primary care.

Primary care physicians are frequently involved in the longitudinal care of patients with alcohol problems and in helping patients to decrease their alcohol consumption. Recent clinical trials provide evidence in support of new treatment strategies for these patients. Brief interventions have been used successfully to reduce alcohol consumption in patients with hazardous and harmful drinking. Twelve-step facilitation, cognitive behavioral, and motivational enhancement therapies have produced sustained drinking reductions in patients with alcohol dependence. Pharmacologic therapies, such as naltrexone and acamprosate, have been effective in decreasing alcohol consumption when provided along with psychosocial counseling in patients with alcohol dependence. The current review highlights the application of these new therapies to primary care physicians' efforts on behalf of their patients with alcohol problems.

Acamprosate↗

PubMed2000

Alcohol exposure and health services utilization in older veterans.

The objective of this study was to determine if increased alcohol exposure is associated with greater use of health services among older veterans. A total of 129 older veterans (> or =65 years old), receiving longitudinal care in a Veterans' Administration primary care clinic, were followed retrospectively for up to 42 months. Subjects were screened at baseline for problem drinking with the CAGE or the quantity-frequency questions from the Alcohol Use Disorders Identification Test (QF-AUDIT), and stratified by exposure into three categories: abstainers, social drinkers, and problem drinkers. Outcomes included total outpatient clinic visits, laboratory tests, radiologic and other technologic procedures, as well as acute care hospitalizations. For all subjects (N = 129), no association was found between alcohol exposure and use of any outpatient services. Among CAGE-screened (n = 62) abstainers, social drinkers, and problem drinkers, significant differences were found in the median number of laboratory tests (7.3 vs. 3.4 vs. 7.1, P = 0.004) and hospitalizations (0.3 vs. 0.0 vs. 0.3, P = 0.001) per patient year of follow-up. No exposure-outcome associations were present, however, among QF-AUDIT-screened subjects (n = 67). We were unable to demonstrate a consistent relationship between alcohol exposure and health services utilization. The effects of alcohol on older veterans' use of health services varied with the method used to measure alcohol exposure. Additional studies are needed to determine whether multiple, or possibly new, measures can more precisely define the health effects of alcohol in older populations.

Aged↗

PubMed2000

Similarities in the disturbances in cortical information processing in alcoholism and aging: a pilot evoked potential study.

OBJECTIVE: To examine the hypothesis that chronic alcohol use causes accelerated aging of the brain. METHODS: The auditory evoked potentials (EPs) were compared in three groups of 10 subjects each: (a) middle-aged individuals meeting DSM-IV criteria for alcohol dependence, (b) age- and gender-matched group of healthy individuals, and (c) an older (>65 years) group of gender-matched healthy individuals. Multiple levels of cortical information processing were examined using EPs. Early stages of information processing, related to sensory gating and stimulus classification (P50, N100/P200), were studied using a paired-click paradigm. Later stages of information processing associated with memory upgrading and identification of novel stimuli (P300) were studied using an oddball paradigm. RESULTS: The amplitude and latency of the P300 of the alcoholic patients and the older healthy subjects differed significantly from those of the younger healthy group. Both groups showed changes that have been reported in association with aging. A tendency towards decreased sensory gating in later stages of information processing was noted in the aged healthy individuals. CONCLUSIONS: These data suggest that alcohol dependence may accelerate the aging process. The tendency towards a sensory gating deficit during the attentive phase of information processing in older healthy subjects requires further investigation because it may be a marker for an increased proneness to developing psychotic symptoms in that group.

Adult↗

PubMed1999

Alcohol use and functional disability among cognitively impaired adults.

BACKGROUND: The extent to which alcohol exposure increases risk for functional disability among older adults with cognitive impairment has not previously been assessed. OBJECTIVE: To examine the potential relationship between alcohol use and functional disability among older cognitively impaired adults. DESIGN: Retrospective medical record review. SETTING: Hospital-based geriatric assessment center. PARTICIPANTS: Two hundred forty-two consecutive participants with Mini-Mental Status Examination scores of < or = 24. MEASUREMENTS: Proxy-reported alcohol intake was classified in categories of never, former, light (< 1 drink/week), moderate (> or = 1 but < 14 drinks/week), and heavy (> or = 14 drinks/week) drinkers, and functional status was determined by proxy-reported performance in seven basic (BADL) and seven instrumental (IADL) activities of daily living (0 = poorest function and 14 = best function). RESULTS: Compared with never drinkers, moderate drinkers demonstrated higher mean BADL (12.2 vs 11.4, P = .033) and IADL scores (6.6 vs 5.6, P = .067), whereas heavy drinkers had higher BADL (12.8 vs 11.4, P = .019) but lower IADL scores (4.8 vs 5.6, P = .425). Former drinkers demonstrated both lower BADL (10.8 vs 11.4, P = .107) and IADL scores (3.9 vs 5.6, P = .011) compared with never drinkers. Evaluation of a potential dose-response effect was limited due to low numbers of light and heavy drinkers. CONCLUSIONS: Among cognitively impaired adults, moderate and heavy drinkers demonstrated better BADL function, whereas former drinkers had poorer IADL function, compared with never drinkers. Prospective studies that incorporate additional measures of exposure (e.g., cumulative lifetime consumption) and function (e.g., performance-based tests) may provide a more comprehensive understanding of alcohol's effects among older cognitively impaired adults.

Activities of Daily Living↗

PubMed1998

The consequences of overdiagnosis and overtreatment of Lyme disease: an observational study.

BACKGROUND: The adverse consequences associated with overdiagnosis and overtreatment of Lyme disease, although previously recognized, have received inadequate attention. OBJECTIVE: To determine the use of health services and occurrence of treatment-related illness, disability, and distress among patients in whom Lyme disease is inappropriately diagnosed or treated. DESIGN: Observational cohort study. SETTING: University-based Lyme disease clinic. PARTICIPANTS: 209 patients with a presumptive diagnosis of Lyme disease previously assigned by referring physicians, the patients themselves, or both. MEASUREMENTS: Self-reported data, review of medical records, and standardized instruments were used to determine 1) use of health services in terms of number of outpatient visits, number of physicians seen, types of serologic tests, and days of antibiotic treatment; 2) occurrence of antibiotic-related adverse events; and 3) levels of disability, depression, and stress. RESULTS: Of the 209 patients, 44 (21%) met criteria for active Lyme disease, 40 (19%) had previous but not active Lyme disease, and 125 (60%) had no evidence of current or previous infection. In general, patients with active Lyme disease (who were not the focus of this study) had good outcomes. Patients with previous Lyme disease and patients with no evidence of Lyme disease used considerable health resources (median number of office visits, 11 and 7; median number of serologic tests, 4 and 4; and median days of antibiotic treatment, 75 and 42), had frequent minor adverse drug events (53% and 55%), reported significant disability (proportion of symptomatic days during which normal activities could not be performed, 16% and 18%), and had high rates of depression (38% and 42%) and stress (52% and 45%). CONCLUSIONS: Overdiagnosis and overtreatment of Lyme disease are associated with inappropriate use of health services, avoidable treatment-related illness, and substantial disability and distress.

Adult↗

PubMed1998

Academic calculations versus clinical judgments: practicing physicians' use of quantitative measures of test accuracy.

PURPOSE: To determine how often practicing physicians use the customarily recommended quantitative methods that include sensitivity, specificity, and likelihood ratio indexes; receiver operator characteristic (ROC) curves; and Bayesian diagnostic calculations. PARTICIPANTS AND METHODS: A random sample of 300 practicing physicians (stratified by specialty to include family physicians, general internists, general surgeons, pediatricians, obstetrician/gynecologists, and internal medicine subspecialists) were briefly interviewed in a telephone survey. They were asked about the frequency with which they used the formal methods, the reasons for non-use, and if they employed alternative strategies when appraising tests' diagnostic accuracy. RESULTS: Of the 300 surveyed physicians, 8 (3%) used the recommended formal Bayesian calculations, 3 used ROC curves, and 2 used likelihood ratios. The main reasons cited for non-use included impracticality of the Bayesian method (74%), and nonfamiliarity with ROC curves and likelihood ratios (97%). Of the 174 physicians who said they used sensitivity and specificity indexes, 165 (95%) did not do so in the recommended formal manner. Instead, the physicians directly estimated tests' diagnostic accuracy by determining how often the test results were correct in groups of patients later found to have, or to be free of, the selected disease. CONCLUSIONS: The results indicate that most practicing physicians do not use the formal recommended quantitative methods to appraise tests' diagnostic accuracy, and instead report using an alternative direct approach. Although additional training might make physicians use the formal methods more often, the physicians' direct method merits further evaluation as a potentially pragmatic tool for the determination of tests' diagnostic accuracy in clinical practice.

Adult↗

PubMed1998

Physician awareness of alcohol use disorders among older patients.

OBJECTIVES: To determine primary care physicians' awareness of, and screening practices for, alcohol use disorders (AUDs) among older patients. DESIGN: Cross-sectional telephone survey of a national sample of primary care physicians. PARTICIPANTS: Physicians randomly sampled from the Masterfile database of the American Medical Association and stratified by specialty as family practice physicians, internal medicine physicians, and either family practice or internal medicine physicians with geriatric certification. MAIN RESULTS: A total of 171 physicians were contacted: 155 (91%) agreed to participate, and responses were analyzed from 150 (50 family practice, 50 internal medicine, 50 with geriatric certification). The median prevalence estimate of AUDs among older patients was 5% for each group of physicians. In contrast to published prevalence rates of AUDs ranging from 5% to 23%, 38% of physicians reported prevalence estimates of less than 5%, and 5% cited estimates of at least 25%. Compared with the other groups, the physicians with geriatric certification were more likely to report no regular screening (42% vs 20% for family practice vs 18% for internal medicine, p = .01), while younger (<40 years) and middle-aged physicians (40-55 years) reported higher annual screening rates relative to older physicians (>55 years) (77% vs 60% vs 44% respectively, p = .03). Among physicians who regularly screened (n = 110), 100% asked quantity-frequency questions, 39% also used the CAGE questions, and 15% also cited use of biochemical markers. CONCLUSIONS: Primary care physicians may "underdetect" AUDs among older patients. The development of age-specific screening methods and physician education may facilitate detection of older patients with (or at risk for) these disorders.

Aged↗

PubMed1997

Geriatric substance use disorders.

AUDs are increasingly recognized as common problems among older adults. The magnitude of this problem is likely to increase over ensuing decades as baby boomers reach retirement age with drinking habits that are significantly different from current cohorts of older adults. Barriers to detection are numerous and include nonspecificity of alcohol-related presentations, patient denial, and clinicians' unwillingness to recognize that patients can and do develop alcohol problems in later life. Despite the limitations of current screening and diagnostic instruments, the authors recommend use of the CAGE as a formal screening tool for older patients because of its brevity, demonstrated efficacy, and convenience. In patients who answer affirmatively to any CAGE question, diagnostic certainty can be increased by use of follow-up questions or referral to an alcohol treatment specialist. Referral of patients with established alcohol abuse or dependence is essential for definitive treatment, and successful outcomes can be expected and are gratifying once achieved. In patients with less severe AUDs, brief interventions with frequent follow-up are recommended. Age-specific screening and diagnostic instruments for older AUD patients, once fully developed and validated, will facilitate identification. Much less is known about other substance use disorders in older adults. Psychoactive drug use is not uncommon in this patient population and may result in adverse health outcomes. Treatment interventions proposed for AUDs are advocated for older adults found to have other substance use disorders as well and are likely to yield improved outcomes. Future investigations that better define the epidemiology, detection, and treatment of other substance use disorders in older populations are clearly warranted at this time.

Aged↗

PubMed1997

The case of Medea--a view of fetal-maternal conflict.

Medea killed her children to take away the smile from her husband's face, according to Euripides, an offence against nature and morality. What if Medea had still been carrying her two children, perhaps due to give birth within a week or so, and had done the same? If this would also have been morally reprehensible, would that be a judgment based on her motives or on her action? We argue that the act has multiple and holistic moral features and that, in fact, there is no absolute principle, such as the right of the fetus to life, which governs our moral judgments about fetal-maternal conflicts. We suggest that they illustrate a pervasive feature of human moral discourse and can only be addressed by attending to a range of negotiable moral considerations which depend on particular features of each situation.

Abortion, Eugenic↗

PubMed1992

Hydrophobicity scale for proteins based on inverse temperature transitions.

In general, proteins fold with hydrophobic residues buried, away from water. Reversible protein folding due to hydrophobic interactions results from inverse temperature transitions where folding occurs on raising the temperature. Because homoiothermic animals constitute an infinite heat reservoir, it is the transition temperature, Tt, not the endothermic heat of the transition, that determines the hydrophobically folded state of polypeptides at body temperature. Reported here is a new hydrophobicity scale based on the values of Tt for each amino acid residue as a guest in a natural repeating peptide sequence, the high polymers of which exhibit reversible inverse temperature transitions. Significantly, a number of ways have been demonstrated for changing Tt such that reversibly lowering Tt from above to below physiological temperature becomes a means of isothermally and reversibly driving hydrophobic folding. Accordingly, controlling Tt becomes a mechanism whereby proteins can be induced to carry out isothermal free energy transduction.

Amino Acid Sequence↗

PubMed1988

A source of error in phenylketonuria screening.

The escalating number of blood specimens from late-fed premature or very sick newborns greatly increases the risk of missing the diagnosis of phenylketonuria (PKU). Babies receiving antibiotics have uninterpretable "clear-zone" results with the traditional Guthrie bacteriologic inhibition assay (BIA). For the past year the authors have reexamined the blood phenylalanine level on specimens giving the "clear-zone" effect by BIA by use of the McCaman-Robins chemical-fluorescent assay (CFA). Spuriously high blood phenylalanine levels occurred in four babies who were receiving ampicillin and whose specimens were collected on filter paper and autoclaved in preparation for the BIA. None of the babies proved to have PKU. The fluorescent interference caused by ampicillin resulted from the heat of autoclaving the specimen. The authors recommend that the blood specimen should not be autoclaved before analysis by either BIA or CFA.

Agar↗

PubMed1984

Effects of diethyldithiocarbamate and nickel chloride on glutathione and trace metal concentrations in rat liver.

Concentrations of reduced glutathione (GSH) and oxidized glutathione (GSSG) and 4 trace metals (Ni, Cu, Mn, Zn) were measured in livers from rats treated with sodium diethyldithiocarbamate (DDC, 0.67 or 1.33 mmol/kg, i.m.) and NiCl2 (0.25 or 0.50 mmol/kg, s.c.), singly or in combination. In rats treated with DDC or NiCl2, singly, hepatic GSH was diminished at 4 h and returned to control levels (or slightly above) at 17 h. In rats that received DDC plus NiCl2, hepatic GSH was not diminished at 4 h after increased 1.4-1.8-fold at 17 h. Hepatic GSSG was diminished at 4 h after NiCl2 treatment and returned to control values at 17 h; hepatic GSSG did not differ from control values at 4 h or 17 h after treatment with DDC, alone or combined with NiCl2. Hepatic Ni was below the detection limit (approximately 20 nmol/g) in control and DDC-treated rats; hepatic Ni was increased to 53 +/- 26 (S.D.) nmol/g at 17 h after treatment with NiCl2 alone, and was increased 6-fold (308 +/- 63 nmol/g) in rats that received Ni plus DDC. Under the same conditions, hepatic Zn was increased 33% or 41%, respectively, in rats that received NiCl2 or DDC, singly, and was not further increased by combined treatment; hepatic Cu and Mn concentrations were unaffected by NiCl2 or DDC, singly, but were diminished in rats that received NiCl2 and DDC. This study suggests: (a) that increased hepatic uptake of Ni is largely responsible for the synergistic induction of heme oxygenase activity in rats treated with NiCl2 and DDC; and (b) that increased hepatic uptake of Zn contributes to the induction of hepatic metallothionein by NiCl2 and DDC.

Animals↗