Biomedical subjects
Publications and source records attributed to M Wood.
First-generation designs that covered a large area of enamel but had minimal retentive features still provided sufficient longevity to be classified as "permanent" type restorations. The goal of long-term service can be realized more consistently by incorporating second-generation designs with the ease of adhesive bonding.
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This paper describes the application of a window diagram technique to optimize the four components of eluent (sodium acetate, sodium heptanesulfonate, acetonitrile and pH adjusted by monochloroacetic acid), for complete separation of five catecholamine compounds and the internal standard (3,4-dihydroxybenzylamine, DHBA). In addition, studies were performed to address the problem of the variable recovery of DHBA from dog plasma due to a time-dependent loss of DHBA. We found that this phenomenon can be prevented by pH adjustment prior to addition of DHBA, allowing development of an accurate high-performance liquid chromatographic assay for plasma catecholamines in dogs.
We report a case of de novo acute monocytic leukemia in a 25-year-old man in whom the sole clonal cytogenetic abnormality was an additional isochromosome 1q. Cytogenetic polymorphisms indicate that, in addition to the formation of the isochromosome, a duplication of the remaining normal chromosome 1 had taken place. Other reported cases suggest an association between acute monocytic leukemia and i(1q).
To better understand the development of primary care classifications over the past 15 years, 10 primary care databases have been retrospectively analysed using the structure of the International Classification of Primary Care (ICPC) as the basis. All datasets were based on routine data collection using different classification systems by several family physicians during all encounters with their patients over considerable periods of time, in most cases one year. The prevalences or the rates of the available diagnostic--and reason for encounter--classes were distributed over four frequencies. With a few exceptions the distribution of diagnostic labels referring to common diseases is surprisingly similar. The use of ICPC however results in a quantum leap in the use of symptom and complaint diagnoses. Because of this shift primary care physicians now have available a classification with 400 diagnostic classes used with a prevalence of > or = 1/1000 patient-years or per 1000 visiting patients per year. The classification of reasons for encounter allows the physician to identify over 300 reasons for encounter used > or = 1/1000 patient years or per 1000 visiting patients per year. Family physicians have been successful in the development of new primary care classifications. Rag bag rubrics which are the result of the structure of ICPC are used relatively often and deserve more attention from primary care taxonomers.
The International Classification of Primary Care (ICPC) was developed to order medical concepts into classes that have been chosen for their relevance for family medicine. Family physicians use this to label the most prevalent conditions in their practice as well as their patients' symptoms and complaints. At the same time they do not want to be divorced from the needs of the medical community at large as these are reflected in the most recent medical nomenclature: the Tenth Revision of the International Classification of Diseases (ICD-10). A full conversion between all classes in the first and seventh component of ICPC (n = 646) with those of ICD-10 (n = 1983), with the exception of the chapter on external causes, has been prepared. It was concluded that ICD-10 at the three-digit level cannot function as a core classification for an international primary care system. Of the three-digit ICD-10 rubrics only 120 are compatible on a one to one basis with an ICPC rubric. A total of 114 three-digit ICD-10 rubrics have to be broken open into four-digit rubrics to allow at least one compatible conversion to one or more ICPC rubrics. On this basis only 25% of the diagnostic classes in ICPC can be converted to a single three- or four-digit ICD-10 rubric without lumping. The rest of ICD-10, either on the three- or on the four-digit level, has to be grouped into combinations of classes (lumping) to allow compatible conversion to the remaining rubrics of ICPC. Even though ICD-10 cannot serve as a core classification for primary care, a technical conversion between ICPC and ICD-10 is practically always possible which allows primary care physicians to implement ICD-10 as a contemporary nomenclature within the classification structure of ICPC.
There is considerable variability in the elimination clearance of the opioid analgesic alfentanil. It has been shown previously that alfentanil clearance is independent of the polymorphic debrisoquine hydroxylase (P-450 2D6), and it is therefore of interest to identify the human cytochrome P-450 enzymes involved in noralfentanil formation, the primary reaction involved in the oxidative N-dealkylation at the piperidine nitrogen. Purified human P-450 3A4 showed appreciable catalytic activity, and yeast recombinant P-450 3A4 also showed alfentanil oxidation activity. When microsomes prepared from different human liver samples were compared, noralfentanil formation activity was well correlated (r = 0.95,P less than 0.005) with nifedipine oxidation (a P-450 3A4 marker) but not with markers of other P-450s, including phenacetin O-deethylation (P-450 1A2), chlorzoxazone 6-hydroxylation (P-450 2E1), and (S)-mephenytoin 4'-hydroxylation (a P-450 2C enzyme). Using antibodies that recognize specific human P-450 enzymes (immunoinhibition techniques), it was possible to demonstrate that anti-P-450 3A4 nearly completely inhibited alfentanil oxidation activity in the human liver microsomes, but no other antibodies showed a measurable inhibitory effect. Selective chemical inhibitors of P-450 3A4, gestodene and troleandomycin, inhibited as much as 90% of the microsomal noralfentanil formation activity, but other chemical inhibitors did not show a detectable inhibitory effect. 7,8-Benzoflavone inhibited as much as 90% of the alfentanil oxidation activity of the microsomal or reconstituted P-450 3A4 system. This work indicates that P-450 3A4 contributes significantly to human liver microsomal alfentanil oxidation, whereas P-450 2D6 does not contribute.(ABSTRACT TRUNCATED AT 250 WORDS)
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Diagnosis, treatment, prognosis, and the neurobiology of recovery of facial paralysis has been impeded by the inability to quantitate facial movement objectively. The purpose of this paper is to report our preliminary results in the study of the paralyzed face using a newly developed computerized quantitative dynamic analysis system. Five normal volunteer subjects, and 17 patients with facial paralysis or paresis, from a wide range of etiologies, were analyzed utilizing the computerized analysis system; eight of these patients had synkinesis. Raw data image-change intensity: duration curves, numeric and graphic displays of curve parameter descriptive statistics, and rank order correlation analyses showed high levels of correlation between the computerized facial motion analysis and the House-Brackmann facial nerve grading system and a clinical grading scale for synkinesis. These data suggest that it is possible to develop a computerized image-difference analysis system that approximates the human ability to access facial movement and, additionally, deliver an equal-interval continuous quantitative data scale dynamic over a spectrum of time during facial motion.
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Since 1960, most newer medical schools have been community-based and have used existing community hospitals and a large number of volunteer faculty. As these schools have evolved, many have developed more traditional characteristics. To assess the positive and negative features of these new schools, chairs of departments of surgery from 21 community-based medical schools and 17 traditional schools were surveyed to acquire information on policies and practices related to faculty development, undergraduate and graduate education, hospital relationships, clinical activities, research, and relationships with community physicians. Responses were analyzed and compared. Most community-based schools have succeeded in their mission, partly at the expense of controls usually found in more traditional schools.
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Although self-monitoring of blood glucose (SMBG) is an integral part of the daily self-care regimen for the effective management of insulin-dependent diabetes mellitus (IDDM), compliance with this task remains a significant problem, particularly for adolescents. Research should be focused on identifying other management approaches which may supplement SMBG. One potential approach involves placing greater reliance on the patient's own ability to estimate glucose levels. Although some research has examined blood glucose self-estimation in adults, little is known about this construct in children and adolescents. The purpose of the current study was to examine the accuracy of blood glucose self-estimates in adolescents with IDDM and examine the relation between child characteristics and accuracy. The results for 70 adolescents with IDDM indicated that as a group they were moderately accurate in estimating their glucose levels; however, much variability in accuracy was found among subjects. Subject characteristics were not found to be significantly related to accuracy.
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We have studied the effect of i.v. anaesthesia with propofol in the emulsion (Intralipid) formulation on drug distribution and metabolism in six dogs using dual-route administration of propranolol as a model compound. Each dog was studied on two consecutive days: day 1 awake and day 2 during propofol anaesthesia (6 mg kg-1 followed by an infusion of 0.8 mg kg-1 min-1). Propofol anaesthesia was associated with reduced intrinsic clearance by 40% (P less than 0.05) but no significant difference in systemic clearance or hepatic plasma flow. Propofol produced marked changes in drug distribution; volume of distribution (Vss) of propranolol increased 54% from 82.5 (SEM 7.3) litre awake to 127.3 (27) litre during propofol anaesthesia (P less than 0.05). This change was accompanied by an increase (P less than 0.05) in the free fraction of propranolol from 8.5 (0.7) % in awake to 14.0 (0.7) % in propofol-anaesthetized dogs. The combination of the effects of both drug clearance and protein binding resulted in a 65% decrease in the intrinsic clearance of unbound drug (P less than 0.05). In contrast with the effects of propofol on drug distribution, infusion of Intralipid alone in another group of six dogs had no significant effects on drug distribution, protein binding or drug metabolism. We conclude that propofol is a modest inhibitor of drug metabolism, but has major effects on propranolol distribution, possibly by changing plasma protein binding.