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Biomedical subjects

M Haynie

Publications and source records attributed to M Haynie.

10 recordsLinked to original sources
PubMed2000

Frequency and clinical implications of fluid dynamically significant diffuse coronary artery disease manifest as graded, longitudinal, base-to-apex myocardial perfusion abnormalities by noninvasive positron emission tomography.

BACKGROUND: Diffuse coronary atherosclerosis is the substrate for plaque rupture and coronary events. Therefore, in patients with mild arteriographic coronary artery disease without significant segmental dipyridamole-induced myocardial perfusion defects, we tested the hypothesis that fluid dynamically significant diffuse coronary artery narrowing is frequently manifest as a graded, longitudinal, base-to-apex myocardial perfusion abnormality by noninvasive PET. METHODS AND RESULTS: In this study, 1001 patients with documented coronary artery disease by coronary arteriography showing any visible coronary artery narrowing underwent rest-dipyridamole PET perfusion imaging. Quantitative severity of dipyridamole-induced, circumscribed, segmental PET perfusion defects was objectively measured by automated software as the minimum quadrant average relative activity indicating localized flow limiting stenoses. Quantitative severity of the graded, longitudinal, base-to-apex myocardial perfusion gradient indicating fluid dynamic effects of diffuse coronary artery narrowing was objectively measured by automated software as the spatial slope of relative activity along the cardiac longitudinal axis. CONCLUSIONS: In patients with mild arteriographic disease without statistically significant dipyridamole-induced segmental myocardial perfusion defects caused by flow-limiting stenoses compared with normal control subjects, there was a graded, longitudinal, base-to-apex myocardial perfusion gradient significantly different from normal control subjects (P=0. 001) that was also observed for moderate to severe dipyridamole-induced segmental perfusion defects (P=0.0001), indicating diffuse disease underlying segmental perfusion defects; 43% of patients with or without segmental perfusion defects demonstrated graded, longitudinal, base-to-apex perfusion abnormalities beyond +/-2 SD of normal control subjects, indicating diffuse coronary arterial narrowing by noninvasive PET perfusion imaging.

Adult↗
PubMed1992

Fluoroscopic placement of jejunal feeding tubes.

Over a two-and-one-half year period, 50 children underwent placements of jejunal tubes through a nasal route (NJ, n = 47) or through an existing gastrostomy site (GJ, n = 119). There were four attempted placements (98% success rate). The NJ tubes remained in place an average of 13 days, and the GJ tubes remained in place an average of 37 days. Fluoroscopic time for placement of an NJ tube averaged 6 min (29 cases), and for a GJ tube 8 minutes (91 cases). In spite of the limited retention time, fluoroscopic time, and availability of alternative methods, fluoroscopically placed jejunal feeding tubes are still playing an active role in this institution.

Child, Preschool↗
PubMed1992

Project School Care: integrating children assisted by medical technology into educational settings.

The increasing number of children assisted by medical technology in the U.S. has led to a need for systematic planning for the children's care in community settings such as schools. Project School Care in Massachusetts provides consultation to school systems as schools respond to the challenge of integrating children assisted by medical technology into educational settings. The model of practice described includes the step-wise planning process and the ensuing training, enrollment, and monitoring procedures. Implications are explored with particular emphasis on upgrading of skills at all medical and educational levels. More input from school health personnel in administrative decision-making around enrollment of children with special health care needs is recommended. For these children, a health care plan should be incorporated into their Individualized Education Plans and into their school records.

Boston↗
PubMed1991

Myocardial metabolism of fluorodeoxyglucose compared to cell membrane integrity for the potassium analogue rubidium-82 for assessing infarct size in man by PET.

Potassium loss from damaged myocardial cells is linearly related to CPK enzyme loss reflecting extent of necrosis. The potassium analog, rubidium-82 (82Rb), is extracted after i.v. injection and retained in viable myocardium but is not trapped or washed out of necrotic regions. To compare myocardial cell metabolism with membrane dysfunction as indicators of necrosis/viability, 43 patients with evolving myocardial infarction and coronary arteriography had positron emission tomography using fluorodeoxyglucose (FDG) and the potassium analog 82Rb. Percent of heart showing FDG defects and 82Rb washout on sequential images indicating failure to retain the potassium analogue were visually assessed and quantified by automated software. Infarct size based on rubidium kinetics correlated closely with size and location on FDG images (visual r = 0.93, automated r = 0.82), suggesting that loss of cell membrane integrity for trapping the potassium analog 82Rb parallels loss of intracellular glucose metabolism, both comparable quantitative markers of myocardial necrosis/viability.

Carbohydrates↗
PubMed1991

Technology's children: report of a statewide census of children dependent on medical supports.

In April 1987, a census of children dependent on medical technology was carried out in Massachusetts to determine the one-month point prevalence. All medical and educational providers in the state who were likely to interact with such children were contacted and asked to complete a two-sided data form on youngsters (aged 3 months to 18 years) with tracheostomies, supplementary oxygen, respirators, suctioning, gastric feeding, central venous lines, ostomies, ureteral diversion, urethral catheterization and dialysis. Nearly 1250 children were found meeting these criteria. Capture-recapture analysis set the lower bound for technology dependence at 0.08% of the state's children. An analysis of the organ systems involved showed that 57% of the children had neurologic involvement--13% multisystem, 7% gastrointestinal-metabolic, 4% renal-genitourinary, and 3% musculoskeletal. Less than 1% of the children were reported as having immunologic or "other" disorders. Review of putative etiologies indicated that 45% of the children had congenital anomalies, 33% chronic medical diseases, 9% perinatal conditions, 7% hereditary-genetic disorders, 5% injuries, 2% infections, and 3% "other." The substantial prevalence of technology dependency among children creates challenges at the social, economic, and policy-making levels. It will be important to carry out systematic reporting and monitoring activities throughout time and across sites. This census is an example of one such statewide effort.

Adolescent↗
PubMed1990

Limited myocardial perfusion reserve in patients with left ventricular hypertrophy.

Experimental studies in animals have suggested that coronary flow reserve may be limited in patients with left ventricular hypertrophy (LVH). Accordingly, to noninvasively determine the effect of LVH on myocardial perfusion reserve, 25 patients, 9 with LVH and 16 controls, underwent positron imaging with rubidium-82 (82Rb) (30-55 mCi) or nitrogen-13 (13N) ammonia (12-19 mCi) at rest and following intravenous dipyridamole and handgrip stress. LVH was documented by echocardiographic and/or electrocardiographic measurements. LVH patients had either no chest pain (n = 8) and/or a normal coronary angiogram (n = 6). Nine simultaneous transaxial images were acquired, and the mean ratio of stress to rest activity (S:R), based on all regions for each heart, was calculated as an estimate of myocardial perfusion reserve. There were no regional differences in activity (i.e., perfusion defects) in any of the studies. S:R averaged 1.41 +/- 0.10 (s.d.) for controls and 1.06 +/- 0.09 for patients with LVH (p less than 0.0001). These data provide support for an abnormality in perfusion reserve in patients with LVH.

Cardiomegaly↗
PubMed1979

Enhanced uptake of 3H-glucosamine by macrophages stimulated by macrophage-activating factor.

The enhanced uptake and incorporation of 3H-glucosamine by guinea pig peritoneal exudate macrophages stimulated by macrophage-activating factor (MAF) were studied. MAF was produced by concanavalin A- (Con A) stimulated lymphocytes. Two systems were developed to assay this phenomenon, one using microtiter plates, the other using suspension cultures. Enhanced uptake of 3H-glucosamine by macrophages was found after 48-hr incubation in microtiter plates and after 24 hr in suspension cultures. Increased uptake of 14C-glucose and 3H-galactose was also observed under these conditions. The enhanced uptake of 3H-glucosamine was markedly reduced or abolished by the addition of glucose to the cell cultures or by replacement of the medium with fresh medium before pulsing with labeled sugar. These observations indicate that the mechanism of enhanced uptake reflects in part increased glucose utilization by the stimulated macrophages.

Animals↗
PubMed1976

Changes in anticoagulation in dogs assayed by three methods.

As a preliminary to a membrane oxygenator study, a study was made of clotting indices in dogs and their intercorrelation and relationship to human data. The most useful criterion for monitoring coagulation in experimental extracorporeal systems was sought. Linear regression and correlation analysis indicated that activated partial thromboplastin time (APTT) predicted whole blood clotting time with a correlation of 0.77 (p less than 0.01). Changes in the APTT with time after heparinization were similar to those previously reported in man, making the animal model an acceptable one for use in developing extracorporeal systems such as the membrane oxygenator. When blood activated recalcification time (BART), APTT, and whole blood clotting time (WBCT) assays were compared on the basis of applicability to studies of extracorporeal support, the APTT and the BART assays proved superior to the WBCT assay due to their reduced variability and increased speed of determination. The variability of the BART assay was the lowest, and its sensitivity was the same as the APTT assay. The principal drawback to the BART assay was not experienced in this study; that is, its dependence on adequate platelet levels which are unpredictable in extracorporeal systems.

Animals↗
PubMedDate not supplied

Prevalence of medical technology assistance among children in Massachusetts in 1987 and 1990.

In 1987 and 1990 in Massachusetts, surveys were conducted to determine the size, pattern of distribution, and trends in the population of children assisted by medical technology. The authors obtained an unduplicated count of all Massachusetts children from 3 months to 18 years of age who used one or more of the following: tracheostomy, respirator, oxygen, suctioning, gastrostomy, jejunal or nasogastric feedings, ostomies, urethral catheterization, ureteral diversion, intravenous access, or dialysis. By comparing counts obtained from medical and educational sources, the authors were able to perform a capture-recapture analysis to estimate the overall number of children dependent upon these technologies. The number of children identified in our surveys increased from 1,085 in 1987 to 1,540 in 1990. However, the capture-recapture analysis yielded estimates of 2,147 plus or minus 230 for 1987 and 2,237 plus or minus 131 for 1990. This suggests that the population of children dependent upon medical technology was essentially stable during this period, and that the 42 percent increase in the number of children identified in our survey reflected improved sampling techniques. During the 3 years, shifts in the pattern of technology use were noted, however. Use of oxygen and gastrostomy increased, and urostomy use declined. A change in the age distribution of the children was also documented, with a shift in the preponderence of technology use from 12 to 24 months in 1987 to children in the first year of life in 1990. Using the 1990 estimate and the 1990 U.S. census figures, an overall prevalence estimate of 0.16 percent was calculated. Applying this to the U.S.child population yields an estimate of 101,800 children assisted by medical technology nationwide(assuming comparable technology use in other States). This information will facilitate policy analysis and program planning on regional and national levels for this medically complex group of children.

Adolescent↗