Biomedical subjects

Martin H Leamon

Publications and source records attributed to Martin H Leamon.

7 recordsLinked to original sources

PubMed2006

Attentional control and brain metabolite levels in methamphetamine abusers.

BACKGROUND: Methamphetamine abuse is associated with neurotoxicity to frontostriatal brain regions with concomitant deleterious effects on cognitive processes. METHODS: By using a computerized measure of selective attention and single-voxel proton magnetic resonance spectroscopy, we examined the relationship between attentional control and brain metabolite levels in the anterior cingulate cortex (ACC) and primary visual cortex (PVC) in 36 currently abstinent methamphetamine abusers and 16 non-substance-using controls. RESULTS: The methamphetamine abusers exhibited reduced attentional control (i.e., increased Stroop interference) compared with the controls (p = .04). Bonferroni-adjusted comparisons revealed that ACC levels of N-acetyl aspartate (NAA)-creatine and phosphocreatine (Cr) were lower and that levels of choline (Cho)-NAA were higher in the methamphetamine abusers compared with the controls, at the adjusted p value of .0125. Levels of NAA-Cr, but not of Cho-NAA, within the ACC correlated with measures of attentional control in the methamphetamine abusers (r = -.41; p = .01) but not in controls (r = .22; p = .42). No significant correlations were observed in the PVC (methamphetamine abusers, r = .19; p = .28, controls, r = .38; p = .15). CONCLUSIONS: Changes in neurochemicals within frontostriatal brain regions including ACC may contribute to deficits in attentional control among chronic methamphetamine abusers.

Adult↗

PubMed2005

High-dose methadone maintenance in pregnancy: maternal and neonatal outcomes.

OBJECTIVE: This study assesses the effect of higher doses of methadone during pregnancy on maternal and fetal outcomes. STUDY DESIGN: We retrospectively reviewed clinical data for 81 mothers who received methadone and their 81 offspring. The cohort was divided into high-dose (>/=100 mg) and low-dose (<100 mg) groups. RESULTS: There were no differences in the rate of medication treatment for neonatal abstinence symptoms or days of infant hospitalization between the high-dose (mean, 132 mg) and low-dose (mean, 62 mg) groups. Despite longer histories of opiate abuse, the high-dose group had less illicit drug use at delivery. The whole cohort, which received an average of 101 mg/d, had an 81% rate of negative toxicology screens at delivery. CONCLUSION: High doses of methadone were not associated with increased risks of neonatal abstinence symptoms but had a positive effect on maternal drug abuse. Arbitrarily limiting methadone dose as a way of minimizing the risks of neonatal abstinence symptoms may be unwarranted.

Adult↗

PubMed2005

Measuring teaching effectiveness in a pre-clinical multi-instructor course: a case study in the development and application of a brief instructor rating scale.

BACKGROUND: Despite widespread use, misunderstandings persist about student evaluations of teaching. These evaluations have not been well examined in the common medical school setting of the multi-instructor, preclinical lecture course. PURPOSE: The study evaluated the psychometrics of a brief student evaluation of a teaching instrument developed for a multi-instructor 2nd-year course and described its application. METHODS: An 11-item instrument was developed and administered to 276 students to evaluate 27 lecturers per year in 3 years of an introductory clinical psychiatry course. A fully crossed research design allowed for a thorough analysis of variability in ratings. RESULTS: Generalizability analysis showed good reliability and relatively large Student x Lecturer interactions. Profile analysis generated distinct lecturer teaching profiles. CONCLUSIONS: Judicious use of a psychometrically sound student evaluation of a teaching instrument can be used to assist faculty and course development. Administering the evaluation instrument to an entire class produces no better reliability than administration to randomly selected subgroups of students.

Education, Medical, Undergraduate↗

PubMed2002

Educational perspectives: a discussion of teaching among colleagues.

Educational perspectives can be useful guides to our teaching in psychiatry. Nevertheless, formal training about teaching in psychiatry is uncommon and rarely includes the study of educational perspectives or theory that underlies teaching. Using a modified case-based format, the authors present three different critiques of a hypothetical faculty member who teaches from a behavioral learning perspective. Feedback from faculty with cognitive, social learning, and interpersonal-inspiration perspectives is provided. The value and application of understanding educational perspectives in teaching is discussed.

Journal Article↗

PubMed2002

Hospitalization of patients with cocaine and amphetamine use disorders from a psychiatric emergency service.

OBJECTIVES: Among the illicit stimulants, cocaine and amphetamines are the most widely abused. Although these drugs have similar psychoactive properties and routes of administration, their duration of action and mechanism of action are different, as are the psychiatric problems that accompany their use. The authors explored whether these differences and results of urine drug testing were associated with differences in use of psychiatric inpatient services. METHODS: The records of 2,357 patients admitted to a large county psychiatric emergency service were examined to determine whether patients admitted for amphetamine-related or cocaine-related disorders differed in rates of transfer to an inpatient psychiatric ward or in length of stay on the ward after transfer. The authors also examined whether positive or negative results of urine drug screens predicted transfer or length of stay. RESULTS: Patients with amphetamine-related disorders were more than a third more likely than patients with cocaine-related disorders to be transferred to the inpatient ward. Patients with negative urine screens were a third more likely than those with positive screens to be transferred and stayed slightly longer on the ward after transfer. Patients with cocaine-related disorders stayed slightly longer on the ward than patients with amphetamine-related disorders. CONCLUSIONS: Patients with amphetamine-related disorders have higher rates of psychiatric hospitalization than patients with cocaine-related disorders. Diagnostic uncertainty and other factors may also influence transfer rates and subsequent length of stay.

Adolescent↗

PubMed2002

Teaching implications of different educational theories and approaches.

Educational theory can and should form the basis for teaching in veterinary medicine. Nevertheless, formal training for teachers in veterinary medicine is uncommon and rarely includes study of different educational theories or perspectives, leaving educators to rely on informal or "hidden" educational constructs to guide them in their everyday teaching. Using a modified case-based format, we present critiques of a hypothetical teaching scenario from four different educational viewpoints: behaviorist, cognitive, social learning, and inspired teaching approaches. The importance and utility of formal educational theory in faculty development is discussed.

Education, Veterinary↗

PubMedDate not supplied

Epidemiology and public health Consequences of methamphetamine use in California's Central Valley.

Methamphetamine use is an increasingly serious public health problem in California and other parts of the country. Despite sensationalistic media attention, however, very little is known about users of this clandestinely consumed drug. Employing methods known as Rapid Assessment and Response, the authors describe the epidemiology and public health implications of methamphetamine use in California's Central Valley, with a focus on Sacramento, which many social indicators suggest has been more severely affected by methamphetamine than any city in the nation. Data sources for this report include interviews with drug users, statistical reports, epidemiologic studies, and local informed expert opinion. In their social demography, methamphetamine users in the Central Valley are in marked contrast to those of coastal cities such as Seattle and San Francisco, being largely heterosexual, and of mixed racial/ethnic heritage. Three-quarters or more initiate their use of the drug while still in their teens, with more than a quarter beginning use before the age of 15. Many of these rapidly gravitate to regular use, and continue using well into their thirties. Methamphetamine users are at much higher risk of infection with HIV than opiate users, particularly if they inject. Partly because methamphetamine enhances libido, users of the drug typically also have many more sexual partners. Not surprisingly, data indicate that methamphetamine users are more likely than heroin users to be HIV-infected. Methamphetamine appears to be less of a street drug than heroin, complicating efforts at street outreach. However, because it is typically used in social settings, a social or diffusion approach to HIV prevention might be particularly promising.

Amphetamine-Related Disorders↗