Biomedical subjects

M Marcus

Publications and source records attributed to M Marcus.

At least 55 records · Page 3Linked to original sources

PubMed1998

Consistency across panels of ratings of appropriateness of dental care treatment procedures.

OBJECTIVE: To report on a study investigating the consistency across different consensus panels of ratings of appropriateness for dental procedures. RESEARCH DESIGN: The study conducted four consensus panels to determine, under various conditions, the appropriateness of five options for patients: no treatment; filling; crown; root canal with a filling or crown; extraction. The patients were categorised according to age; regular versus irregular use of dental care; degree of caries; degree of pain; degree of periodontal disease. PARTICIPANTS: The panellists were dentists enrolled in a continuing education programme on assessing the quality of dental care. The panellists were all individuals employed by various dental plans to evaluate the quality of care plans operating in California. RESULTS: The results indicate that the method does distinguish the dimensions of appropriateness used by the panellists in making their decisions, and that it is possible to substantially increase consensus among a diverse group of dentists and across separate panels on some procedures. However, it also showed that the process is sensitive to varying panels and that different variables had different outcomes in the ratings from the various panels. CONCLUSION: The consensus panel method holds some promise for determining the appropriateness of dental care. However the results of this study question whether it results in consistent ratings across different panels.

Adult↗

PubMed1997

The Union Health Center: a working model of clinical care linked to preventive occupational health services.

As health care provision in the United States shifts to primary care settings, it is vital that new models of occupational health services be developed that link clinical care to prevention. The model program described in this paper was developed at the Union Health Center (UHC), a comprehensive health care center supported by the International Ladies Garment Workers Union (now the Union of Needletrades, Industrial and Textile Employees) serving a population of approximately 50,000 primarily minority, female garment workers in New York City. The objective of this paper is to describe a model occupational medicine program in a union-based comprehensive health center linking accessible clinical care with primary and secondary disease prevention efforts. To assess the presence of symptoms suggestive of occupational disease, a health status questionnaire was administered to female workers attending the UHC for routine health maintenance. Based on the results of this survey, an occupational medicine clinic was developed that integrated direct clinical care with worker and employer education and workplace hazard abatement. To assess the success of this new approach, selected cases of sentinel health events were tracked and a chart review was conducted after 3 years of clinic operation. Prior to initiation of the occupational medicine clinic, 64% (648) of the workers surveyed reported symptoms indicative of occupational illnesses. However, only 42 (4%) reported having been told by a physician that they had an occupational illness and only 4 (.4%) reported having field a workers' compensation claim for an occupational disease. In the occupational medicine clinic established at the UHC, a health and safety specialist acts as a case manager, coordinating worker and employer education as well as workplace hazard abatement focused on disease prevention, ensuring that every case of occupational disease is treated as a potential sentinel health event. As examples of the success of this approach, index cases of rotator cuff tendonitis, lead poisoning, and formaldehyde overexposure in three patients and their preventative workplace follow-up, affecting approximately 150 workers at three worksites, are described. Work-related conditions diagnosed during the first 3 years of clinic operation included cumulative trauma disorders (141 cases), carpal tunnel syndrome (47 cases), low back disorders (33 cases), lead poisoning (20 cases), and respiratory disease (9 cases). This pilot project represents a new model for effective integration of clinical care and occupational disease prevention efforts within a primary care center. It could serve as a prototype for development of such services in other managed and primary care settings.

Ambulatory Care Facilities↗

PubMed1997

Differential effects of acute and chronic nicotine on dopamine output in the core and shell of the rat nucleus accumbens.

Like several drugs of abuse, nicotine increase dopamine (DA) release in the nucleus accumbens (NAC). In the present study, the effects of acute and chronic nicotine on DA output in two subdivisions of the NAC, the core and the shell, which are largely associated with motor control and limbic functions, respectively, were examined by means of in vivo differential normal pulse voltammetry in anesthetized, pargyline-treated rats. In the first experiment, acute administration of nicotine (25, 50 and 100 micrograms/kg, cumulative doses; i.v.) was found to increase DA levels in the NACshell to 163% of baseline, whereas DA output in the NACcore was not significantly affected. In the second experiment, animals were pretreated with twelve daily injections of saline or nicotine (0.5 mg/kg, i.p.); about 24 hours after the last injection, the animals were challenged with nicotine (50 micrograms/kg and 100 micrograms/kg, cumulative doses; i.v.). Under these conditions, nicotine increased DA output in the NACshell in saline-pretreated animals to 248% and in nicotine-pretreated rats to 180%. Also, nicotine increased DA output in the NACcore in saline-pretreated animals to 185%, whereas no significant effect was observed in nicotine-pretreated rats. The results of the present experiments indicate (i) that acutely administered nicotine or nicotine challenge in chronically pretreated animals with either saline or nicotine consistently increases DA release to a greater extent in the NACshell than in the NACcore, and (ii) that chronic nicotine pretreatment reduces the stimulatory-action of nicotine on DA output in either the shell or the core subdivision of the NAC.

Animals↗

PubMed1997

Measurement variability in upper extremity posture among VDT users.

Hand and arm posture while keying is frequently mentioned as a risk factor for upper extremity musculoskeletal disorders (UEMSDs) among video display terminal (VDT) operators. However, many epidemiologic studies have not included measures of posture of VDT operators, in part, because of the difficulty of assessing posture rapidly and reliably among large numbers of subjects. For a single measure of posture to be useful for estimating dose-response relationships between posture and risk of UEMSDs, the within-subject variability of the postural measure must be smaller than the between-subject variability of the postural measure. In addition, the measure must be stable over time. We estimate the ratio of between- to within-subject variability for manual goniometry by measuring six postural angles on six occasions among 19 subjects using VDTs. For each postural angle, between-subject variability was substantially and statistically significantly larger than within-subject variability. Stability of postural measures over time was sufficient to justify a single postural measurement in epidemiologic studies. We conclude that manual goniometry can provide useful information about upper extremity posture among VDT users for use in epidemiologic studies of UEMSDs.

Adult↗

PubMed1997

Clinical measures and treatment needs.

Clinically evaluated oral health outcome variables from the ICS-II USA data set were examined in the diverse ethnic groups, for two adult age cohorts (35-44 and 65-74 years). These measures were derived from epidemiological examinations and include the DMFT components, loss of attachment, and an indicator of treatment need--the ratio of decayed teeth over decayed and filled teeth. The ratio of decayed over decayed and filled teeth was used in multivariate analysis, since this measure represents an area where public policy could have an impact if determinants were understood. The most important independent variables were race-ethnicity, educational attainment, no fear of dental visits because of pain, and oral hygiene practices. Having a usual source of dental care and visiting the dentist within the past 12 months did not appear to be as important in predicting unmet needs as these other variables. To bridge the gap between the oral health status of majority and minority populations, health educators in minority communities need to become more accessible, have a pro-active interest in oral health, and also be cognizant of the various socio-cultural issues influencing oral health. The problems regarding Native American adults are more complex and require more careful study.

Adult↗

PubMed1997

Consumer satisfaction.

Patient satisfaction with dental care is compared across six United States groups: Whites in Baltimore and San Antonio, African-Americans in Baltimore, Hispanics in San Antonio, and Native Americans in the Southwest and the Dakotas. First, differences in patient satisfaction across ethnic groups and between two age groups (65-74 years old and 35-44 years old) are considered. Generally, people from all age and ethnic groups were satisfied with the last dental visit. Second, patient satisfaction is conceptualized as an oral health outcome influenced by characteristics of the dental service utilizer: predisposing sociodemographic characteristics, predisposing oral beliefs, enabling characteristics, oral needs, oral health behaviors, and oral health status. Multivariate analyses by age and ethnic group are used to identify characteristics that influence patient satisfaction. Sociodemographic characteristics were important among the elderly. Strong oral health beliefs influenced patient satisfaction among younger adults. Enabling characteristics were important predictors among the Native American groups. This model explained 15%-30% of the variability in patient satisfaction among the study age and ethnic groups.

Adult↗

PubMed1997

Nitrate toxicosis in beef and dairy cattle herds due to contamination of drinking water and whey.

Four cases of rarely reported nitrate toxicosis due to contamination of drinking water or whey were recorded in 2 beef and 2 dairy cattle herds. In the cases associated with water contamination, water containing ammonium nitrate as a fertilizer for irrigating orchards accidentally entered drinking water troughs for cattle through malfunctioning 1-way valves. The whey contamination in 1 instance was caused by transportation in containers which contained traces of concentrated ammonium nitrate; the 2nd case was induced by whey derived from the production of a specialty cheese produced by the incorporation of nitrate. Mortality occurred in 2 herds and abortions in the 2 other herds. Affected cows responded well to treatment, but some animals remained in a deteriorated physical condition for several months.

Animal Feed↗

PubMed1996

Upper extremity musculoskeletal symptoms among female office workers: associations with video display terminal use and occupational psychosocial stressors.

The relationships between musculoskeletal symptoms and both video display terminal (VDT) use and occupational psychosocial stress were assessed among women office workers by self-administered questionnaires. Significantly increased odds ratios for neck or shoulder symptoms were observed for subjects who had ever used a VDT, had less job security, and had more stressful work during the 2 weeks prior to completion of the questionnaire. Significantly increased odds ratios for arm and hand symptoms were observed for subjects who had used a VDT for more than 6 years, reported a very crowded workplace, or reported very stressful work during the 2 weeks prior to completion of the questionnaire. Among current non-users, those who previously used VDTs were more likely to report upper extremity musculoskeletal symptoms than those who had never used VDTs. This suggests that individuals with symptoms may be more likely to reduce their VDT usage, distorting results of cross-sectional studies.

Adult↗

PubMed1996

Methodological limitations in the study of video display terminal use and upper extremity musculoskeletal disorders.

Upper extremity musculoskeletal disorders may occur as a result of work with keyboard-equipped video display terminals. Many studies of the associations between keyboard use and upper extremity disorders have appeared in both the human factors and occupational epidemiologic literature. Methodological limitations and inconsistent results have limited conclusions that can be made from these studies, however. Although exposure conditions can be carefully controlled, human factors studies are limited by relatively small sample sizes, short exposure durations, and reliance on outcome measures with unknown relevance to chronic adverse health effects. Epidemiologic studies have been limited by poor ascertainment of both exposure and health outcome. Many have failed to control for any potential confounding. An almost exclusive reliance on cross-sectional study designs has resulted in possible bias from selective survival, exposure-effect reversal, and poor estimates of exposures occurring prior to development of the disorder. Given the inconsistency in the literature and the growing controversy surrounding this issue, prospective study of this question using objective methods for assessment of exposure and health outcome is recommended. This design allows identification of incident cases and minimizes bias from selective survival. In addition, ergonomic and psychosocial variables prior to onset of symptoms can be ascertained periodically. Given estimates for up to 100 million video display terminals to be in use in the United States by the year 2000, clarification of the health effects of their use is critical.

Arm Injuries↗

PubMed1996

Indicators of oral health in diverse ethnic and age groups: findings from the International Collaborative Study of Oral Health Outcomes (ICS-II) USA research locations.

Racial-ethnic group differences are assessed using a standardized set of oral health indicators, as well as various predisposing, enabling and need characteristics collected in the International Collaborative Study of Oral Health Outcomes (ICS-II) USA research locations. The unique data set contains comparable data on African-American, Native American, Hispanic, primarily Mexican-American, and White adults. Age group differences in oral health indicators are also compared in two adult age cohorts (35-44 and 65-74 years). Since data were collected from geographically diverse regions of the United States, differences in oral health indicators are considered within the context of different dental care delivery systems and external environments. Results indicate that the gap in oral health between Whites and ethnic minority groups is pervasive across research locations and age cohorts. Variation in regional dental care delivery systems and the varying effects of race-ethnicity and age cohort suggest that alternative health promotion strategies will be needed for improving oral health in diverse populations.

Adult↗

PubMed1996

Comparison of access and costs of Medicaid dental services in a hospital clinic and community practices.

OBJECTIVES: This paper reports the results of a three-year evaluation of access to dental care and its associated costs for Aid to Families with Dependent Children (AFDC) beneficiaries enrolled in a hospital-based health maintenance organization (HMO) or a fee-for-service (FFS) option. METHODS: Medicaid enrollees (n = 3, l655) having a year of eligibility were assigned to either the hospital HMO or FFS care, and their use of dental care and its costs compared. RESULTS: A higher percent of those beneficiaries enrolled in the FFS option used dental care than those in the HMO plan. FFS enrollees also had more annual visits per person than those in the randomly assigned HMO group. FFS dental patients treated in the hospital had the highest costs of any payment-provider combination studied. CONCLUSIONS: To understand the mix of utilization rates, visits, and costs, one must take into account the way in which the HMO hospital plan is reimbursed, the way in which the dental department is reimbursed, and the way in which the dental provider is reimbursed.

Adolescent↗

PubMed1995

New trends in natural language processing: statistical natural language processing.

The field of natural language processing (NLP) has seen a dramatic shift in both research direction and methodology in the past several years. In the past, most work in computational linguistics tended to focus on purely symbolic methods. Recently, more and more work is shifting toward hybrid methods that combine new empirical corpus-based methods, including the use of probabilistic and information-theoretic techniques, with traditional symbolic methods. This work is made possible by the recent availability of linguistic databases that add rich linguistic annotation to corpora of natural language text. Already, these methods have led to a dramatic improvement in the performance of a variety of NLP systems with similar improvement likely in the coming years. This paper focuses on these trends, surveying in particular three areas of recent progress: part-of-speech tagging, stochastic parsing, and lexical semantics.

Algorithms↗

PubMed1995

Ritanserin potentiates the stimulatory effects of raclopride on neuronal activity and dopamine release selectivity in the mesolimbic dopaminergic system.

The atypical profile of clozapine and some other new antipsychotic drugs has been attributed to a relatively selective effect on the mesolimbic dopaminergic system, as well as to their potent serotonin 5-HT2 receptor antagonism and high ratio of 5-HT2 to dopamine D2 receptor affinities. It is unclear, however, how concurrent 5-HT2 and D2 receptor antagonism specifically affects the mesoaccumbens and the mesocortical dopaminergic systems. The present study examined the effect of pretreatment with the 5-HT2 receptor antagonist, ritanserin, on changes in midbrain dopamine neuronal activity as well as in forebrain, extracellular concentrations of dopamine, induced by relatively low doses of the D2 receptor antagonist raclopride, utilizing in vivo extracellular single cell recording techniques and voltammetry in anesthetized rats, as well as microdialysis in freely moving rats. Raclopride alone (10-2560 microgram/kg, i.v.) induced a dose-dependent increase in three parameters of neuronal activity, i.e. burst firing, firing rate and variation coefficient, of midbrain DA neurons. This effect of raclopride was more pronounced in cells of the ventral tegmental area than in cells of the substantia nigra-zona compacta. Ritanserin alone (1.0 mg/kg, i.v.) also increased all three parameters of neuronal activity in dopamine cells of the ventral tegmental area, but only firing rate in the cells of the substantia nigra. Ritanserin pretreatment (30 min) significantly enhanced the stimulatory effects of low doses of raclopride (10-20 micrograms/kg, s.c.) increased extracellular concentrations of dopamine in the medial prefrontal cortex and the dorsolateral striatum by 75 and 110%, respectively, as measured by microdialysis. Ritanserin alone (1.5 mg/kg, s.c.) did not significantly affect cortical and striatal extracellular dopamine concentrations; however, pretreatment (40 min) with ritanserin elevated the raclopride-induced increase of dopamine concentrations in the medial prefrontal cortex of about 250%, but failed to affect the action of raclopride on striatal dopamine levels. Raclopride alone (10 and 320 micrograms/kg, i.v.) dose-dependently increased extracellular concentrations of dopamine in the nucleus accumbens and the dorsolateral striatum to about 500%, as determined by voltammetry. Ritanserin alone (1.0 mg/kg, i.v.) did not significantly affect the voltammetric dopamine signal in the nucleus accumbens or the dorsolateral striatum; however, ritanserin pretreatment (30 min) enhanced the raclopride-induced increase in accumbal but not striatal dopamine concentrations to about 1600%. The stimulatory effect of the combined ritanserin plus raclopride treatment on neuronal activity and DA release was more pronounced in the mesolimbic than the nigrostriatal dopaminergic system. The present data indicate that concurrent 5-HT2 and D2 receptor antagonism selectively affects the activity of the mesolimbic dopaminergic system. These findings provide an experimental basis for the notion that combined 5-HT2 and D2 receptor antagonism may underlie the limbic mode of action of at least some atypical antipsychotic drugs and consequently contribute to their unique therapeutic effects.

Animals↗

PubMed1995

Mode of action of atypical neuroleptics in relation to the phencyclidine model of schizophrenia: role of 5-HT2 receptor and alpha 1-adrenoceptor antagonism [corrected].

In experiments in rats, by the use of single-cell recordings from midbrain dopamine (DA) neurons of the ventral tegmental area (VTA), the systemic administration of the schizophrenomimetic N-methyl-D-aspartate receptor antagonists phencyclidine (PCP) or dizocilpine (MK-801) caused an increased firing rate but reduced the variability of firing in VTA DA neurons. Burst firing was increased in cells predominantly located in the paranigral nucleus, a subdivision of the VTA largely projecting to the nucleus accumbens and other limbic regions, but reduced in DA cells predominantly located in the parabrachial pigmented nucleus, another subdivision of the VTA that projects largely to the prefrontal cortex (PFC). Thus, a severely impaired signal-to-noise ratio within the PFC DA projection was obtained, concomitant with an overactive mesolimbic DA system. The administration of high doses of ritanserin or atypical neuroleptics with prominent serotonin (5-hydroxytrypyamine) 5-HT2 receptor antagonist action, such as clozapine or amperozide, produced preferential activation of the PFC DA projection. In contrast, the selective D2 receptor antagonist raclopride caused a greater activation of the subcortical than cortical DA projections, as assessed by microdialysis experiments in vivo from our laboratory. Adding ritanserin treatment to raclopride markedly enhanced the raclopride-induced increase in DA levels in the medial PFC, an effect probably mediated by augmentation of the raclopride-induced increase in the burst firing of meso-cortical DA neurons, but failed to affect the action of raclopride on striatal DA levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

PubMed1995

Neuroepithelial bodies in relatively mature lungs: an investigation in prenatal and newborn lambs.

Lungs of fetal and neonatal lambs were found to contain small, inconspicuous and widely dispersed neuroepithelial bodies (NEB). Under the light microscope, NEB could only be identified with certainty by their positive immune reaction to antibodies against serotonin. At the ultrastructural level, a large number of dense-cored vesicles was found in the corpuscular cells of the NEB. However, the number of intracorpuscular nerve endings was small. We conclude from these findings that, in the lamb, NEB act primarily as local regulators of lung function and that their reflex-mediated actions may be of secondary importance. This may be related to the fact that lungs of lambs at birth are relatively mature compared to those of various other species. Increased maturation of lungs and a concomitant decreased risk of insufficient oxygenation might be associated with the presence of an oxygen-sensitive chemoreceptor with primarily local actions for prevention of hypoxia.

Animals↗

PubMed1995

Managed care and dentistry: promises and problems.

At its inception in the mid-1950s, managed care held a number of promises for dental care providers and dental patients. Sometime during the development of managed care, however, many programs lost sight of the importance of provider equity. Using data from current programs, the authors contrast the original promises with the realities of managed care in dentistry.

Capitation Fee↗

PubMed1994

Prazosin modulates the changes in firing pattern and transmitter release induced by raclopride in the mesolimbic, but not in the nigrostriatal dopaminergic system.

Most antipsychotic drugs are, in addition to being dopamine (DA) D2 receptor antagonists, also relatively potent alpha 1 adrenoceptor antagonists. Here, we have studied the effects of the selective DA D2 receptor antagonist raclopride, alone and in combination with the selective alpha 1 adrenoceptor antagonist, prazosin, on midbrain DA neurons utilizing extracellular single cell recording techniques. As a reference compound, haloperidol (0.05-1.6 mg/kg, i.v.), a potent antagonist at both DA D2 receptors and alpha 1 adrenoceptors, was included in the electrophysiological part of the study. In addition, in vivo voltammetry was used to measure extracellular DA concentrations in the nucleus accumbens (NAC) and the dorsolateral striatum (STR) in anesthetized, pargyline pretreated rats treated with the above drugs. Raclopride (10-5120 micrograms/kg, i.v.) induced a dose dependent increase in firing rate of DA neurons in the ventral tegmental area (VTA), that was significant already at 10 micrograms/kg, and in the substantia nigra-zone compacta (SN-ZC), that reached significance at 2560 micrograms/kg. Burst firing of DA neurons was also increased in the VTA at 40 micrograms/kg, as well as in the SN-ZC at 640 micrograms/kg. A low dose of raclopride (80 micrograms/kg, cumulated dose) induced a significant increase in extracellular DA concentrations in NAC to 490% and in STR to 220%. A high dose of raclopride (2560 micrograms/kg, cumulated dose) induced a 930% increase in extracellular DA concentrations in NAC, but only a 280% increase in STR. These data demonstrate that raclopride exerts a relatively selective action on mesolimbic DA neurons. Prazosin (0.3 mg/kg, i.v.) decreased burst firing of VTA, but not SN-ZC DA neurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Factors associated with the use of screening mammography in a primary care setting.

Despite consensus recommendations the use of screening mammography remains low. We examined physician and patient related variables associated with requests to undergo screening mammography in a primary care setting, in order to assess current barriers to screening mammography at the level of the physician-patient interaction. A sample of 261 women over the age of 50, whose primary care was provided by resident physicians in a large, urban, academic medical center were examined. Data concerning patients and physicians demographic and clinical characteristics were abstracted. The data were analyzed by Chi-square and stepwise logistic regression. Forty-five percent of the patients were offered screening mammography within the study year and 53% were offered mammography over the preceding two years. Variables significantly associated with a request for screening included a previous history of breast disease (p < .001) and the severity of the patient's overall medical condition. Patients with an overall medical condition rated as mild were more likely to be requested to undergo screening than patients rated as moderately or severely ill (p < .01). Patients with higher educational levels were also more likely to be offered screening (P = .06). First year postgraduate (PGY 1) physicians requested more mammograms than PGY 2 or PGY 3 physicians (P < .05). A multivariable model utilizing logistic regression confirmed the association of the significant variables above with screening requests. Physicians were more likely to request mammography in patients at higher risk for developing breast cancer and less likely to request it in patients who had co-morbid illness. Increasing physician understanding of the importance and benefits of mammography and further investigation of strategies to ensure physician compliance with mammography recommendations are necessary to increase utilization.

Aged↗