Biomedical subjects

D B Matthews

Publications and source records attributed to D B Matthews.

30 records · Page 2Linked to original sources

PubMed1995

Acute ethanol impairs spatial memory but not stimulus/response memory in the rat.

The present studies investigate how acutely administered ethanol (ETOH) affects the use of spatial memory. Previous electrophysiological results have shown that acutely administered ETOH alters the firing of hippocampal neurons and that prenatal or chronic exposure to ETOH produces deficits on spatial learning tasks, tasks dependent on the hippocampus. In contrast, it has also been demonstrated that acutely administered ETOH does not impair spatial localization. In the current studies, rats were trained to perform a spatial or stimulus/response task under saline. After training, rats were injected with ETOH, and the use of spatial or stimulus/response memory was tested. Acutely administered ETOH impaired the use of spatial memory, but not the use of stimulus/response memory. Because the use of spatial memory requires an intact hippocampus, the present studies suggest that acutely administered ETOH selectively impairs behaviors dependent on the hippocampus.

Animals↗

PubMed1994

The deliberate misdiagnosis of major depression in primary care.

OBJECTIVE: Because the correct diagnosis of a psychiatric condition can jeopardize reimbursement and other benefits, physicians deliberately substitute alternative diagnoses. We estimated the prevalence of alternative coding for major depression by primary care physicians and the reasons for its occurrence. DESIGN: Cross-sectional mail survey with telephone follow-up of nonresponders. SETTING: Primary care practices in communities across the nation. PARTICIPANTS: Physicians were eligible to participate if they were randomly selected from membership lists of two professional organizations of primary care clinicians. Four hundred forty-four physicians (70.0% of eligible physicians and 89.5% of eligible physicians we could locate) completed the survey by mail or telephone. MAIN OUTCOME MEASURE: Substitution of an alternative code for major depression within a 2-week period. RESULTS: Of our respondents, 50.3% (SE, +/- 2.5%) reported that they had substituted another diagnostic code during a 2-week period for one or more patients whom they recognized met the criteria for major depression in the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition. Thirty-one percent of depressed patients received alternative codes. The most common reasons for these substitutions involved physician uncertainty about the diagnosis and problems with reimbursement for services if a diagnosis of major depression was coded. CONCLUSION: The practice of deliberately substituting another diagnostic code for major depression is widespread among primary care providers. Physicians who employ deliberate misdiagnosis circumvent inequitable policies for particular patients, but the impact of substitution on the health care system as a whole deserves more careful consideration.

Adult↗

PubMed1991

Threatening and otherwise inappropriate letters to members of the United States Congress.

The authors examine the characteristics of threatening and otherwise inappropriate communications sent to members of the U.S. Congress by a sample of 86 subjects, 20 of whom threatened assassination. We quote excerpts from these letters and provide quantitative data on such variables as the volume, duration, form, and appearance of such communications; the enclosures; the subjects' perceived relationships to the recipients; the thematic content of the communications; and the messages and threats communicated. Comparisons between 43 subjects who pursued encounters with members of Congress and 43 who did not revealed 17 factors associated with such pursuit. In this population, threateners were significantly less likely to pursue an encounter than inappropriate letter writers who did not threaten, regardless of the type of threat or the harm threatened. Inappropriate letters to members of Congress are compared with those directed to Hollywood celebrities. Mentally disordered persons writing to public figures often mention and sometimes threaten public figures other than those to whom the letters are addressed, which raises important issues regarding notification of endangered third parties and the sharing of information among protective agencies.

Correspondence as Topic↗

PubMed1985

Response of a 'susceptible' Escherichia coli to metronidazole therapy: an investigation using experimental subcutaneous abscesses.

Earlier experiments under anaerobic conditions in vitro had indicated that Gram-negative facultative anaerobes were susceptible to therapeutically attainable concentrations of metronidazole. This prompted us to study the response of one such strain to metronidazole therapy. Mice with 3-day-old subcutaneous abscesses induced by 'susceptible' Escherichia coli (accompanied by potentiating agent and obligately anaerobic Bacteroides fragilis) were given metronidazole by mouth (250 mg/kg/dose 12 hourly) either as a two- or a four-dose course. This therapy reduced the viable numbers of E. coli/abscess by a mere 0.3 log10 and 0.7 log10, respectively. Assays showed that concentrations of metronidazole in abscess-contents compared favourably with those in the earlier in vitro experiments. But measurement of redox potentials in abscesses indicated that the conditions in these (-191 mV vs. Ag/AgCl) were not nearly as reduced as those in experiments in vitro (-650 mV). This, and the known dependence of metronidazole on low redox potentials for expression of its antimicrobial ability, appears to be the explanation for the poor anticoliform effect in the subcutaneous abscess model. Full assessment of the clinical implications of these observations must await the availability of data regarding redox potentials in clinical situations.

Abscess↗

PubMed1982

Fine points aside: data are data.

Movement responses by 5 1/2- to 6 1/2-year-old children on the Holtzman Inkblot Test were reported on by Lockwood et al. in volume 45 of this Journal. Criticism of the findings discussed in that article by J. Swartz, Reinehr, and C. Swartz was published in the December, 1981, volume of the Journal. The present article rebuts their criticism and emphasizes the significance of the original findings which reflect new and highly discrepant normative M response data from that previously available.

Comment↗

PubMed1981

Two studies of the movement responses in young children: new and highly discrepant norms.

The Holtzman Ink Blot Test was administered to 5- to 6-year-old children and analyzed for movement response. The range and frequency of movement response in both an original and replication study are significantly greater than would have been anticipated for this age group based upon available normative data. NO significant differences were found in the frequency of Human Movement and Animal Movement responses. No sex difference among subjects was found in the range and frequency of movement responses produced. These new findings call into question previously reported data as well as some of the theoretical presumptions underlying the production of movement responses by young children.

Journal Article↗

PubMed1981