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Biomedical subjects

M Wood

Publications and source records attributed to M Wood.

At least 19 recordsLinked to original sources
PubMed1992

Optimization of high-performance liquid chromatographic assay for catecholamines. Determination of optimal mobile phase composition and elimination of species-dependent differences in extraction recovery of 3,4-dihydroxybenzylamine.

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.

Animals↗
PubMed1992

Isochromosome 1q in acute monocytic leukemia: a new nonrandom association.

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).

Adult↗
PubMed1992

International primary care classifications: the effect of fifteen years of evolution.

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.

Humans↗
PubMed1992

The conversion between ICPC and ICD-10. Requirements for a family of classification systems in the next decade.

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.

Humans↗
PubMed1992

Identification of the pharmacogenetic determinants of alfentanil metabolism: cytochrome P-450 3A4. An explanation of the variable elimination clearance.

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)

Alfentanil↗
PubMed1992

Computerized quantitative dynamic analysis of facial motion in the paralyzed and synkinetic face.

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.

Adolescent↗
PubMed1991

Direct myocardial revascularization without extracorporeal circulation. Experience in 700 patients.

Between May 1978 and March 1990, 700 patients were operated on with direct coronary surgery without extracorporeal circulation (ECC): 529 (76 percent) were male and 171 (24 percent) were female. The average age was 64 years (range, 35 to 86 years), 454 (65 percent) had unstable angina, 163 (23 percent) had stable angina, 51 (7 percent) had postmyocardial infarction angina, and 32 (5 percent) had acute myocardial infarction at the moment of the operation. In this series of patients, all branches of the coronary arteries were bypassed; the mammary artery was used in 40 percent of the cases, the average bypass per patient was 2.2 (range, 1 to 5), and 26 percent had associated disease of high risk to undergo ECC. The morbidity was 4 percent and the mortality for this series of patients was 1 percent; the probability of survival at seven years was 90 percent. This experience shows us that this surgery is an alternative in the treatment of coronary disease, especially for aged patients with associated disease, in some cases of acute transmural infarction, and also for patients who need coronary angioplasty. Also, it can improve the relation cost/benefit in coronary surgery.

Adult↗
PubMed1979

Altered drug binding due to the use of indwelling heparinized cannulas (heparin lock) for sampling.

The effect of the use of the so-called heparin lock for blood sampling on the binding of propranolol has been studied and a cumulative dose-response curve to heparin constructed. The use of this method of blood sampling introduced considerable artifactual changes into the measurement of propranolol's plasma binding. The free fraction rose from 9.9% to 13.4% after only 50 U of heparin was used to flush the cannula. The increase in the free fraction of propranolol showed excellent correlation with the increase in free fatty acid levels (p less than 0.001, r = 0.996). The importance of ensuring that sampling techniques do not introduce artifactual changes in pharmacokinetic studies is emphasized.

Adult↗
PubMed1979

Acute appendicitis during pregnancy.

Case reports (1970--1977) of thirty-five pregnant women with acute appendicitis were reviewed. Eighty-eight per cent had symptoms less than 24 hours and were operated on within 12 hours. No maternal or fetal loss occurred. Morbidity and mortality should be minimal if, when appendicitis is suspected in a pregnant woman, immediate operation is performed.

Acute Disease↗
PubMed1979

Presidential address: Eponyms in biliary tract surgery.

A selected group of men whose eponyms are currently used in biliary tract surgery are described. The eponyms chosen comprise two areas: gross anatomy (Glisson, Wirsung, Santorini, Winslow, Heister, and Vater) and operative anatomy (Kocher, Courvoisier, Morison, Hartmann, Calot, Roux, and Oddi). A brief review of biliary tract disease from antiquity until the 17th century places these men in proper historical sequence. A condensed biographical sketch of each man's life and work is provided and a few closing comments are made about eponyms.

Animals↗
PubMed1979

Vertebral arteriovenous fistulas.

Vertebral arteriovenous fistulas are rare. A report of two cases is presented with problems related to diagnosis and therapy. An alternative approach to surgical management is given.

Adult↗