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Biomedical subjects

B L Holman

Publications and source records attributed to B L Holman.

At least 37 records · Page 2Linked to original sources
PubMed1996

Abnormal cerebral metabolism in polydrug abusers during early withdrawal: a 31P MR spectroscopy study.

Phosphorus magnetic resonance spectroscopy (31P MRS) at 1.5 T was performed on nine polysubstance abusing men. All nine patients met DSM-III-R criteria for concurrent cocaine and heroin dependence, were neurologically normal, were negative for the human immunodeficiency virus, and had normal clinical brain MRI scans. Patients were scanned 2-7 days after admission to a drug treatment unit. Eleven age-matched control subjects also were studied. The ISIS localized phosphorus spectra were obtained from a 5-cm thick axial brain slice and a 100-cc white matter volume. In the brain slice, the phosphorus metabolite signal expressed as a percentage of total phosphorus signal was 15% higher for phosphomonoesters, 10% lower for nucleotide triphosphates (beta-NTP), and 7% lower for total nucleotide phosphates in polydrug abusers compared with those in controls. Phosphodiesters, inorganic phosphate, phosphocreatine, total phosphorus, pH, and free magnesium concentration were unchanged. None of these parameters correlated with the methadone dose or the number of days abstinence. Single photon emission computed tomographic imaging of a subgroup of the patients revealed abnormal cerebral perfusion in 80% of the patients scanned. These data suggest that cerebral high energy phosphate and phospholipid metabolite changes result from long term drug abuse and/or withdrawal and that these changes can be detected and studied by 31P MRS.

Adult↗
PubMed1996

Collaboration using Internet for the development of case-based teaching files: report of the Computer and Instrumentation Council Internet Focus Group.

UNLABELLED: The Internet and particularly the World-Wide-Web is becoming a useful tool for the nuclear medicine community. METHODS: The Computer and Instrumentation Council of the Society of Nuclear Medicine convened an Internet Focus group to discuss collaboration using the Internet. The prototype application considered was development of case-based teaching files using the World-Wide-Web. Teaching file cases (clinical history, images, description of findings and discussion) on World-Wide-Web servers at different institutions are integrated using the Internet. The user can navigate from case to case using point-and-click hypertext linking. RESULTS: The initial experience with collaboration has been encouraging. An etiquette to help foster collaboration has been proposed. Development of quality control mechanisms and introduction of peer review were identified as issues needing further work. CONCLUSION: The World-Wide-Web offers great potential for new forms of collaboration. There is, however, a need to learn how to make best use of this new resource.

Computer Communication Networks↗
PubMed1995

Occupational and nonoccupational correlates of alcohol consumption in urban transit operators.

BACKGROUND: The influence of occupation and the worksite has emerged as an important area of study in research on alcohol consumption. Occupational and nonoccupational factors were studied in relation to alcohol consumption using data from a 1983-1985 cross-sectional study of transit operators. METHODS: A total of 1.853 operators underwent a medical examination for driver's license renewal (including information on age, ethnicity, gender, education). Of these operators, 1,448 completed a questionnaire about occupational (e.g., time of shift, job stressors) and nonoccupational (e.g., personality, life stressors) factors. From either the medical examination or the questionnaire, weekly alcohol consumption was available for 1,820 operators. Variables related to alcohol consumption in previous studies, or theoretically linked to consumption, were analyzed in relation to heavy ( > or = 15 drinks/week) and average weekly consumption. RESULTS: Heavy and average consumption were both related to several nonoccupational variables, including demographic (age, ethnicity, gender, marital status), personality (depression, anger expression), and life stress variables (i.e., life events). Heavy and average consumption were also related to several occupational variables, including job history (number of years driving, specific worksite) and job stressors. Neither measure was related to subjective job content (job demand, decision latitude). CONCLUSIONS: Variability in consumption by demographic factors among this population reflects that seen in society as a whole. However, occupational factors may influence consumption, since consumption was strongly related to (a) specific worksite and time of shift and (b) reported job stressors. Clarifying the exact influence of occupational and worksite factors on alcohol consumption will depend on the convergence of findings from different research designs (e.g., cross-sectional, longitudinal, ethnographic).

Adult↗
PubMed1995

SPECT perfusion imaging in the diagnosis of dementia.

Single-photon emission computed tomography (SPECT) imaging has provided the practicing clinician with a method of studying brain function in patients with dementia. A large and growing number of papers report the experiences of a number of laboratories in the use of this technique in the evaluation of demented patients. Studies from several laboratories comparing patients with Alzheimer's disease to control subjects report sensitivity and specificity of SPECT perfusion imaging to be in the 80% vicinity. In addition, a number of studies suggest that the dementias that show the greatest similarities in perfusion patterns to Alzheimer's disease are multi-infarct dementia and dementia associated with Parkinson's disease. Although considerable data exists to guide the physician, a rigorous scientific approach to studying patients in a prospective, unselected clinical sample, with autopsy confirmation of the diagnosis, is needed to define clearly the utility of the technique in diagnosing dementias.

Alzheimer Disease↗
PubMed1995

Inside BrighamRAD: providing radiology teaching cases on the Internet.

The Internet provides opportunities for widely distributing educational materials such as teaching files. Since a teaching file is both a tradition and a requirement in an accredited diagnostic radiology training program, many of the same resources can be committed to designing it for Internet access. The advantages include easier availability for the department residents and fellows, communication to a wider audience, the opportunity for networking and collaboration with other institutions during development, and making information available for more rapidly than traditional publications. Since material available on the Internet represents an alternative means of publication, all cases in an electronic teaching file, as is the case with BrighamRad, should be subject to peer review. A successful computer-based teaching file requires department-wide commitment of trainees and staff as well as additional expertise in multimedia instruction, computer-based graphics and design, image manipulation, programming, and database management. Quality efforts take time and require continual adaptation and support as technology and the laws and customs governing the use of electronically published material evolve. The process should be ongoing, and the departmental commitment must be long term and continuous.

Computer Communication Networks↗
PubMed1995

Improved regional cerebral blood flow in chronic cocaine polydrug users treated with buprenorphine.

UNLABELLED: Chronic cocaine and polydrug abuse have been associated with regional abnormalities in cerebral perfusion. The authors have previously demonstrated that these abnormalities are partially reversible after drug addiction treatment with buprenorphine. This study was designed to separate the effect on cerebral perfusion of abstinence from drug use from that of buprenorphine directly. METHODS: Fifteen cocaine- and heroin-dependent men were studied with 99mTc-hexamethylpropyleneamine oxime (HMPAO) brain SPECT. The men, all part of an inpatient drug abuse treatment research program, were randomly assigned after detoxification to receive placebo or either 6 or 12 mg daily buprenorphine treatment. SPECT studies were performed at baseline, after maximum dosage was reached and after tapering off the study drug. Studies were compared visually with regard to the number and location of perfusion defects by reviewers blinded to treatment assignment. RESULTS: Subjects receiving buprenorphine had a significant reduction in the number of defects per study between baseline and maximum buprenorphine dose as compared with those receiving placebo (decrease of 4 +/- 5.4 versus increase of 4.8 +/- 4.7, p = 0.006). These differences were dose-related. Improvement with buprenorphine was temporary, with return to baseline after tapering off. CONCLUSION: Buprenorphine treatment, and not abstinence from drug use alone, leads to improvement in regional cerebral perfusion abnormalities in chronic cocaine- and heroin-dependent men.

Adult↗
PubMed1994

Mitochondrial localization and characterization of 99Tc-SESTAMIBI in heart cells by electron probe X-ray microanalysis and 99Tc-NMR spectroscopy.

As the development of targeted intracellular magnetic resonance contrast agents proceeds, techniques for the quantitative analysis of the subcellular compartmentation and characterization of metallopharmaceuticals must also advance. To this end, the subcellular distribution and chemical state of hexakis (2-methoxyisobutyl isonitrile) technetium-99 (99Tc-SESTAMIBI), the ground state of the organotechnetium radiopharmaceutical used for the noninvasive evaluation of myocardial perfusion and viability by scintigraphy, has been determined by a novel application of electron probe X-ray microanalysis (EPXMA) and 99Tc-NMR spectroscopy. In cryopreserved cultured chick heart cells equilibrated in 36 microM 99Tc-SESTAMIBI, EPXMA imaging of mitochondria yielded a respiratory uncoupler-sensitive characteristic 99Tc X-ray peak representing 32.0 +/- 2.9 nmoles Tc/mg dry weight, while EPXMA of cytoplasm or nucleus showed no peak significantly greater than the threshold detectability limit of approximately 1 nmole/mg dry weight. Technetium-99 NMR spectroscopy of heart cells equilibrated with 99Tc-SESTAMIBI showed a single peak at -45.5 ppm with no evidence of significant line broadening or chemical shift compared to aqueous chemical standards, indicating that the majority of the complex exists unbound within the mitochondrial matrix. These data quantitatively demonstrate the localization of this lipophilic cationic organometallic complex within mitochondria in situ, consistent with a sequestration mechanism dependent on membrane potentials. Furthermore, this study establishes the general feasibility of combined EPXMA and NMR spectroscopy for the direct subcellular localization and characterization of metallopharmaceuticals, techniques that are readily applicable to MR contrast agents.

Animals↗
PubMed1994

In vivo metabolism of the technetium isonitrile complex [Tc(2-ethoxy-2-methyl-1-isocyanopropane)6]+.

Technetium(2-ethoxy-2-methyl-1-isocyanopropane)6+, [Tc-EIBT] is a complex of technetium(I) structurally similar but slightly more lipophilic than the commercial myocardial perfusion agent Cardiolite [Tc-MIBI]. Tc-EIBI exhibits rapid extraction from the blood into heart, liver, kidney and striated muscle and rapid hepatobiliary clearance. In the guinea pig, unlike Tc-MIBI, this compound is almost completely enzymatically metabolized to numerous cationic complexes containing a mixture of ethyl other and hydroxy isonitrile ligands. Substitution of the ethyl other group for a methyl ether produces an agent that shows selective in vivo metabolism and more rapid clearance from the liver.

Animals↗
PubMed1994

Medical impact of unedited preliminary radiology reports.

PURPOSE: To determine the potential frequency of adverse patient outcomes resulting from erroneous preliminary radiology reports. MATERIALS AND METHODS: The authors determined the number of preliminary radiology reports that changed substantively between the preliminary and final version during a 10-day collection period. They analyzed 200 of 1,648 reports to determine the potential for adverse outcome. RESULTS: Only 5.6% of the preliminary radiology reports were changed substantively. Two percent of all reports contained changes that would have led to additional testing or treatment and, possibly, increased morbidity. CONCLUSION: Immediate electronic transfer of a preliminary radiology report results in a small but important number of adverse outcomes; however, if a final edited report follows within 24 hours and referring physicians are called whenever the preliminary report contains erroneous information, the benefits of rapid information transmission may outweigh the additional risks.

Boston↗