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Biomedical subjects

K Young

Publications and source records attributed to K Young.

At least 181 records · Page 10Linked to original sources
PubMed1982

Microbial hazards associated with bean sprouting.

The behaviour of microorganisms was studied in mung beans and alfalfa seeds before and after germination in modified, commercially available bean-sprouting kits. The microorganism were enumerated by the aerobic plate count (APC) and by total yeast and mold count procedures. Salmonella species were artificially inoculated into selected samples and were enumerated by the most probable number (MPN) method. After germination of the beans or seeds into mature sprouts, significant increases were noted in APCs and in MPN values of Salmonella species. Although counts of yeasts and molds did not increase significantly after germination, these samples show an increase in toxic Aspergillus flavus and potentially toxic Alternaria species. The presence of toxic Penicillium cyclopium molds also increase substantially in 5 samples of a single brand of mung beans. Analysis of selected sprout samples, however, showed no presence of aflatoxin.

Aflatoxins↗
PubMed1981

Kinetics of the pretransition of synthetic phospholipids. A calorimetric study.

The pretransition in aqueous dispersions of two synthetic phospholipids (dimyristoylphosphatidylcholine and dipalmitoylphosphatidylcholine) has been examined in detail by differential scanning calorimetry. The transition from the high-temperature state (state above pretransition) to the low-temperature state (state below pretransition) is complex and appears to occur via some metastable states. In contrast, the kinetics of the transition from the low- to the high-temperature state is consistent with an activated two-state model. The observed hysteresis is shown to arise mainly from the kinetic nature of the pretransition.

Calorimetry, Differential Scanning↗
PubMed1980

Development of a social dependency scale.

Social dependence was defined in terms of three capacities identified as necessary for the performance of an adult role. The three capacities are everyday self-care competence, mobility competence, and social competence. Measurement of these concepts was facilitated through the use of 12 6-point scales (4 for each capacity). Scores were then computed for each capacity (range 4-24) and for all three capacities together (range 12-72). Operationally, social dependence was defined as the sum of the individual's scores in the three areas: everyday self-care competence, mobility competence, and social competence. The revised instrument was tested on 60 subjects with advanced diseases to determine its reliability. The reliability coefficient alpha was .90, and the standardized-item alpha was .91.

Activities of Daily Living↗
PubMed1980

Patient response to hydrogel contact lenses: a comparative study.

Eleven subject (22 eyes) wore the best fitting lenses of each of four different types of hydrogel contact lenses (Bausch and Lomb Soflens contact lenses, Hydrocurve HCII contact lenses, AOSOFT-TM/Aquaflex hydrophilic contact lenses, and Alcon Tresoft contact lenses) in a random order for 2-3 week periods so that their short-term responses to the lenses could be evaluated and compared. None of the subjects had any contraindications to hydrogel lens wear. All the lenses centered well with proper movement. Using a double masked procedures, we evaluated each patient's response to each lens type according to the standard of success of Sarver, Harris and Polse. Approximately 63% to 72% of the patients were successful with each lens type. We found no statistically significant differences in the patients' responses to the different lens types, even though individual differences were found. The majority of our subjects were successful with several or all of the lens types evaluated.

Adult↗
PubMed1977

The closure of maternity services in Massachusetts. The causes, process, and hospital impact.

There has been a decline in the number of maternity services in Massachusetts from 120 in 1960 to 65 in 1975. Further consolidation must be carefully thought out with all options and possible outcomes thoroughly explored. The Massachusetts Maternity and Newborn Regionalization Project and the Massachusetts Hospital Association conducted a preliminary survey of Massachusetts Maternity services that had closed to understand the causes, process,, and hospital impact. The findings of this preliminary investigation, in addition to identifying areas for more intensive future research, provide some observations that should be of assistance to those considering a maternity service closure.

Female↗
PubMedDate not supplied

Cardiac function during stress testing in long-standing insulin-dependent diabetics.

Four dynamic tests of cardiac function were compared in a group of 13 long-standing insulin-dependent diabetics who had no clinical evidence of cardio-respiratory disease. One patient developed abnormal features during 24 hour ambulatory electrocardiograms while all 13 patients had normal exercise electrocardiograms. The change in left ventricular ejection fraction during dynamic supine exercise as measured by gated blood-pool scintigraphy was not significantly different from control subjects (p less than 0.1) while during cold stimulation testing the change in left ventricular ejection fraction in the diabetics was highly significantly different from the control subjects (p less than 0.01). Five of the patients had one or more abnormal tests of autonomic function. The cold stimulation test may be a sensitive index of cardiac dysfunction in diabetics but as the mechanism is unclear alternative explanations are possible. While the etiology of heart disease in such patients is uncertain it is likely to be multifactorial and this test may prove useful in investigating the natural history and pathogenesis of cardiac disease in diabetics.

Adolescent↗
PubMedDate not supplied

Assessment of a polyester-covered nitinol stent in the canine aorta and iliac arteries.

PURPOSE: To evaluate the patency and healing characteristics of a woven polyester fabric-covered stent in the canine model. METHODS: Twenty-four self-expanding covered stents were placed in the infrarenal aorta and bilateral common iliac arteries of eight dogs and evaluated at 1 (n = 2), 3 (n = 2), and 6 (n = 4) months. Stent assessment was done using angiography prior to euthanasia, and light and scanning electron microscopy. RESULTS: Angiographically, just prior to euthanasia, 8 of 8 aortic and 14 of 16 iliac endovascular covered stents were patent. Histologically, the stented regions showed complete endothelialization 6 months after graft implantation. A neointima had formed inside the stented vessel regions resulting in complete encasement of the fabric-covered stent by 3 months after graft implantation. Medial compression with smooth muscle cell atrophy was present in all stented regions. Explanted stent wires, examined by scanning electron microscopy, showed pitting but no cracks or breakage. CONCLUSION: The covered stent demonstrated predictable healing and is effective in preventing stenosis in vessels 10.0 mm or greater in diameter but does not completely preclude stenosis in vessels 6.0 mm or less in diameter.

Alloys↗
PubMedDate not supplied

Effect of mecillinam on peptidoglycan synthesis during the division cycle of Salmonella typhimurium 2616.

The effects of mecillinam, ampicillin and cephalexin on peptidoglycan synthesis in Salmonella typhimurium 2616 have been studied at equivalent concentrations or "isoactivities". Using antibiotics at isoactivities allows a direct comparison of the biochemical effects of different antibiotics. When mecillinam was added at different times during the division cycle at a concentration that produced 50% inhibition of peptidoglycan synthesis in an exponential culture over a short period of time, the inhibition of synthesis was greatest in the newborn cells and least in the dividing cells. Antibiotic competition experiments showed that mecillinam preferentially bound to penicillin-binding protein 2 in S. typhimurium 2616. High performance liquid chromatography analysis of the residual peptidoglycan synthesized in the presence of mecillinam showed an unexpected increase in pentapeptides and a significant increase in cross-linking. Other antibiotics added at equivalent activities did not show an increase in cross-linking.

Amdinocillin↗
PubMedDate not supplied

Glycosylated haemoglobin in uraemia.

Glycosylated haemoglobin (GHb) was measured in 71 patients with stable chronic renal failure by the thiobarbituric acid (TBA) reaction and by agar gel electrophoresis. Nineteen patients were diabetic. Of the non-diabetics, 22 were treated conservatively (including 8 children), 15 by maintenance haemodialysis, and 15 by continuous ambulatory peritoneal dialysis. GHb measured by both methods correlated with postprandial blood glucose levels. There was a significant discrepancy between the two methods only in patients with serum urea concentrations greater than 30 mmol/l, mean +/- SD, (6.8 +/- 2.6% vs 8.2 +/- 2.5% for TBA and electrophoresis, respectively). This difference, delta GHb, correlated with serum urea, serum creatinine, and serum bicarbonate, but after logistic regression of results from all 71 patients only serum urea was associated with delta GHb. Lower haemoglobin and GHb and high fetal haemoglobin concentrations in the haemodialysis group suggested increased haemolysis in these patients. Measurement of GHb by the TBA method and by agar gel electrophoresis remain useful indicators of hyperglycaemia in patients with mild, stable chronic renal failure.

Adolescent↗
PubMedDate not supplied

Application of the pin-hole collimator in small animal nuclear scintigraphy: a review.

The pin-hole collimator is used to improve spatial resolution and magnify areas of interest. The pin-hole collimator has many applications in small animal veterinary scintigraphy. The principles of image formation for the pin-hole and parallel hole collimators are reviewed. The effects of distance on resolution and sensitivity are presented for the pin-hole and parallel hole collimators. Specific application of the pin-hole collimator in veterinary scintigraphy are discussed.

Animal Diseases↗
PubMedDate not supplied

Quantitative 99mTc-pertechnetate thyroid scintigraphy in normal beagles.

This study was done to investigate the validity of published canine thyroid/salivary (T/S) ratios of approximately 1 in normal dogs and to determine thyroid uptake of 99mTc-pertechnetate (pertechnetate) measured as percent uptake of injected dose. These parameters were evaluated in 13 Beagle dogs over a 4 hour period. Mean +/- standard deviation (SD) and median T/S ratios of 1.2 +/- 0.3 and 1.1 were essentially the same at twenty minutes and 1 hour. T/S values ranged from 0.9 to 2.2 at 20 minutes and from 0.8 to 2.4 at 1 hour. T/S ratio values progressively declined over the subsequent time intervals with mean +/- SD and median values of 0.6 +/- 0.2 and 0.6, respectively, measured at 4 hours. The mean +/- SD maximum percent dose uptake of pertechnetate within the thyroid gland was 0.55% +/- 0.15% with a range of 0.28% to 0.90%. The mean +/- SD time interval from injection of pertechnetate to maximum uptake within the thyroid gland was 160 +/- 55 minutes with a range 31-240 minutes. The data derived from this study of normal dogs may be useful in the evaluation of dogs with thyroidal diseases including hypothyroidism.

Animals↗
PubMedDate not supplied

Contrast harmonic ultrasound of spontaneous liver nodules in 32 dogs.

Thirty-two dogs with spontaneous hepatic nodules were given intravenous ultrasound contrast medium (Definity or Sonovue) and imaged with contrast harmonic software on a conventional ultrasound machine system. Digital video images were initially reviewed to describe the perfusion pattern of malignant nodules. The images were reviewed again to test this pattern against all individual nodules. Subjectively, there was improved conspicuity of malignant nodules after contrast enhancement compared with conventional imaging and increased numbers of malignant nodules were often noted. There was decreased conspicuity of benign nodules and no additional nodules were seen after contrast enhancement. There was a highly significant (P < 0.0001) association of malignancy with a hypoechoic nodule at surrounding normal liver peak contrast enhancement. Benign nodules were isoechoic to the surrounding normal liver at peak contrast enhancement. Only one benign nodule (hepatoma) had regions of hypoechogenicity compared with the surrounding normal liver at peak liver contrast enhancement. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were highly significant (P < 0.0001) (100%, 94.1%, 93.8%, 100%, and 96.9%, respectively). No complications or morbidity was noted throughout the course of the study. Contrast harmonic ultrasound appears to be accurate at discriminating between naturally occurring benign and malignant nodules in the liver of dogs.

Adenocarcinoma↗