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Biomedical subjects

M C Lee

Publications and source records attributed to M C Lee.

At least 271 records · Page 15Linked to original sources

Use of a total wash-out method in an open heart operation.

Pathological cold agglutinins may induce hemolysis in patients who need hypothermic cardiopulmonary bypass and blood transfusion. A simple technique, termed the total wash-out method, was used in a patient with high thermal amplitude, moderate-titer cold agglutinin before hypothermic cardiopulmonary bypass. The patient's cold agglutinin titer decreased abruptly after operation. None of the preoperative hemolysis phenomena were found during her 6 months of follow-up.

Agglutinins↗

Insensitivity of tensile failure properties of human bridging veins to strain rate: implications in biomechanics of subdural hematoma.

The effects of strain rate on tensile failure properties of human parasagittal bridging veins were studied in eight unembalmed cadavers. While bathed in physiological saline at 37 degrees C, the intact vessel was stretched axially by a servo-controlled hydraulic testing machine at either a low strain rate of 0.1-2.5 s-1 or a high rate of 100-250 s-1. The mean ultimate stretch ratios for low and high strain rates, respectively, were 1.51 +/- 0.24 (S.D. n = 29) and 1.55 +/- 0.15 (n = 34), and the ultimate stresses were 3.24 +/- 1.65 (n = 17) and 3.42 +/- 1.38 MPa (n = 20). Neither difference between strain rates was significant (p greater than 0.45). Thus, our results do not support the hypothesis that sensitivity of the ultimate strain of bridging veins to strain rate explains the acceleration tolerance data for subdural hematoma in primates [Gennarelli, R. A. and Thibault, L. E. (1982) Biomechanics of acute subdural hematoma. J. Trauma 22, 680-686].

Aged↗

Transatrial membranotomy for Budd-Chiari syndrome.

In a 7-year period, transatrial membranotomy was performed in 11 patients with membranous obstruction of the inferior vena cava. There were 5 men and 6 women, ranging in age from 23 to 53 years. Clinical symptoms included jaundice in 4 patients, hepatomegaly in 4, leg edema or varicose veins in 10, and venous collaterals over the abdominal and chest wall in all 11 patients. Transatrial membranotomy was performed through a median sternotomy in all patients. When inferior vena cava venography revealed that the obstruction was accompanied by long segmental thrombosis, additional dilation was performed with a Hegar dilator. There was no surgical mortality. Early operative complications included pulmonary embolism in 2 patients and bleeding requiring reoperation in 1. In a mean follow-up period of 30.6 months (range, 2 to 88 months), 9 patients had no symptoms, transient pericardial constriction developed in 1 patient and resolved 1 month later, and restenosis of the inferior vena cava developed in another patient 1 year after the first operation. This latter patient received a second transatrial membranotomy followed by percutaneous balloon angioplasty of the inferior vena cava, with a satisfactory result at 8 months follow-up. We conclude that transatrial membranotomy is an effective and safe procedure for patients with membranous obstruction of the inferior vena cava.

Adult↗

Muscle glycogen storage postexercise: effect of mode of carbohydrate administration.

The primary purpose of this study was to determine whether gastric emptying limits the rate of muscle glycogen storage during the initial 4 h after exercise when a carbohydrate supplement is provided. A secondary purpose was to determine whether liquid (L) and solid (S) carbohydrate (CHO) feedings result in different rates of muscle glycogen storage after exercise. Eight subjects cycled for 2 h on three separate occasions to deplete their muscle glycogen stores. After each exercise bout they received 3 g CHO/kg body wt in L (50% glucose polymer) or S (rice/banana cake) form or by intravenous infusion (I; 20% sterile glucose). The L and S supplements were divided into two equal doses and administered immediately after and 120 min after exercise, whereas the I supplement was administered continuously during the first 235 min of the 240-min recovery period. Blood samples were drawn from an antecubital vein before exercise, during exercise, and throughout recovery. Muscle biopsies were taken from the vastus lateralis immediately after and 120 and 240 min after exercise. Blood glucose and insulin declined during exercise and increased significantly above preexercise levels during recovery in all treatments. The increase in blood glucose during the I treatment, however, was three times greater than during the L or S treatments. The average insulin response of the L treatment (61.7 +/- 4.9 microU/ml) was significantly greater than that of the S treatment (47.5 +/- 4.2 microU/ml) but not that of the I (55.3 +/- 4.5 microU/ml) treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

Changes in the properties of the thyrotropin receptor antibody in patients with Graves' disease after radioiodine treatment.

We investigated the effect of a single dose of 131I upon thyrotropin receptor antibodies (TRAb) in 21 patients with Graves' disease. The thyrotropin receptor antibodies were assessed by parallel measurements of thyrotropin binding inhibitor immunoglobulin (TBII), thyroid stimulating antibody (TSAb), and thyroid stimulation blocking antibody (TSBAb) in serum by radioreceptor assay, stimulation of adenylate cyclase and inhibition of TSH-stimulated adenylate cyclase activation in FRTL-5 cells, respectively. Prior to radioiodine treatment TBII was detected in all 21 patients and TSAB in 19 patients. After radioiodine treatment TBII activities did not change during 12 months observation period, but in eight patients TSAb activities gradually decreased and were undetectable at the end of a 12 month observation period. Persistence of TSAb was not associated with clinical outcome. Eight patients developed hypothyroidism within 1 year after radioiodine treatment. Three of the hypothyroid patients developed TSBAb, and the appearance of TSBAb coincided with the development of hypothyroidism. These results suggest that TSBAb might develop after radioiodine treatment in a minority of patients with Graves' disease, and that the appearance of TSBAb, in addition to radiation induced thyroid destruction, might be involved in the development of hypothyroidism following radioiodine treatment.

Adolescent↗

[Continuous thoracic epidural fentanyl in postoperative pain control--a comparison of two different dosages].

We evaluate the postoperative pain relief using continuous epidural fentanyl infusion in two different dosages for thoracic and upper abdominal surgeries. A total of 21 ASA class III patients were studied. A thoracic epidural catheter was placed before surgery but pain control was begun when the patients became fully awake and complained of pain in the recovery room. Patients were divided into group A (n = 9) and group B (n = 12). Those in group A were given fentanyl 1.5 micrograms/kg in saline solution as initial dose followed by continuous infusion at a rate of 1 microgram/kg/h for 23 hours. In group B the initial dose and the maintenance dose were respectively 1.0 microgram/kg and 0.5 micrograms/kg/h. Following the initial dose, the intensity of pain was assessed hourly for a total of 24 hours using a visual analogue pain scale with scores from 0 to 10. In group A, the pain scale fell from the baseline level of 7.7 +/- 2.6 to 2.3 +/- 2.0 at the first hour while in group B it fell from 8.9 +/- 1.4 to 4.3 +/- 2.1. The pain scores following continuous infusion in groups A and B were respectively 1.3 +/- 1.5 and 2.9 +/- 1.7. Although the analgesic effect appeared to be better in group A, pain relief was satisfactory in both groups (p less than 0.01). Regarding respiratory depression, there was a greater degree of rise in PaCO2 in group A and some of the patients even had a PaCO2 value above 50 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Oral tramadol for extracorporeal shock wave lithotripsy].

Two hundred patients undergoing shock wave lithotripsy for renal calculi with the improved version of Dornier HM3 lithotripter system were randomly divided into group A and group B with 100 patients in each. Patients in group A were orally given tramadol 100 mg and lorazepam 1 mg and those in group B flunitrazepam 1 mg was given. Those in group A, who did not need supplemental medication during ESWL were subdivided in group A while those who needed an adjuvant of 100 micrograms intravenous fentanyl were subdivided in group A2. Like group A, those in group B, who did not need supplemental drug and those who needed 100 micrograms intravenous fentanyl were respectively subcategorized into groups B1 and B2. Drugs were given with 15 mL water 30 min prior to ESWL. Pre-operatively, an intravenous line and monitoring system which included noninvasive blood pressure and pulse oximeter were established. The entire course was divided into 5 stages i.e. stage I (prior to oral medication), stage II (10 min after medication), stage III (10 min following ESWL), stage IV (5 min following 100 micrograms intravenous fentanyl) and stage V (10 min after ESWL). The mean blood pressure, heart rate and SpO2, pain scale, sedation scale and side effects were recorded in various stages. The results showed that in group A 68 patients passed the ESWL smoothly (A1) and 32 patients needed supplemental fentanyl (A2). In group B 70 patients successfully underwent the ESWL (B1) while 30 patients needed supplemental fentanyl (B2). Ther were no significant changes in both groups in various stages regarding heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

Surgical management of congenital coronary artery fistula.

Over a period of 6 years, 8 patients underwent surgical treatment at our hospital for congenital coronary artery fistula (CAF). The ages of the patients ranged from 4 months to 50 years (mean 22.7 years). Continuous heart murmurs could be heard in all patients, except one. The diagnosis was made by retrograde aortography and/or selective coronary arteriography. Only one patients had associated cardiac disease. All the drainage sites of the CAF were on the right side of the heart (right atrium, right ventricle, pulmonary artery). Two patients had both right and left CAFs. Symptoms due to "coronary steal" by a coronary artery fistula were demonstrated by a nuclear medicine study in one of our patients. Four patients were operated on with the aid of cardiopulmonary bypass. The other 4 patients were treated with suture ligation directly. There was no surgical mortality or morbidity, and the longterm results have been good. Since surgical correction is safe and effective, it would appear desirable for all patients with CAF be operated on. However, surgical intervention is controversial in asymptomatic patients.

Adult↗

Job and life satisfaction among rural physicians. Results of a survey.

Results of a survey of approximately half of Minnesota's rural physicians show that these physicians appear to be well-satisfied with their jobs (average rating of 2.5 on a five-point scale with 2 = very satisfied and 3 = moderately satisfied). In aggregate, areas of greatest job satisfaction are the diversity of patients physicians see, physicians' contact with others, and their ability to derive personal gratification from patient care. Salary/income was not a source of dissatisfaction. Areas of least satisfaction are physicians' opportunities for promotion, their ability to remain knowledgeable, and their role in making organizational and administrative decisions. Rural Minnesota physicians feel least work stress about their feelings of clinical competence/interpersonal relations at work and anxieties about the future. Areas of greatest stress focus on time pressures and realities of medical practice, i.e., being reimbursed by third-party payers and meeting the need for certainty when medical knowledge only allows for approximation. These physicians are reasonably happy with their lives in general (5.4 on a seven-point scale with 7 = delighted, 1 = terrible). In aggregate, areas of lowest life satisfaction are physicians' social relations, leisure activities, and finances. Examination of subgroups shows that women are statistically less satisfied with their living situations; younger physicians are less satisfied with their work, their living situations, and their leisure activities; physicians who spend more than 10 hours per week on administrative duties are less satisfied with their living and social situations; and physicians who see more than 100 patients per week are less satisfied with their social relations.

Humans↗

Acute mitral regurgitation secondary to blunt chest trauma: report of a case.

A 24-year-old male patient who sustained blunt trauma to the chest resulting in a flail chest, myocardial contusion and injury to mitral valve is reported. An emergency surgical correction of the mitral lesion was performed. A high index of suspicion, prompt diagnosis and aggressive intervention of such injuries can lead to successful repair of such a potentially fatal cardiac trauma.

Acute Disease↗

Muscle glycogen storage after different amounts of carbohydrate ingestion.

The purpose of this study was to determine whether the rate of muscle glycogen storage could be enhanced during the initial 4-h period postexercise by substantially increasing the amount of the carbohydrate consumed. Eight subjects cycled for 2 h on three separate occasions to deplete their muscle glycogen stores. Immediately and 2 h after exercise they consumed either 0 (P), 1.5 (L), or 3.0 g glucose/kg body wt (H) from a 50% glucose polymer solution. Blood samples were drawn from an antecubital vein before exercise, during exercise, and throughout recovery. Muscle biopsies were taken from the vastus lateralis immediately, 2 h, and 4 h after exercise. Blood glucose and insulin declined significantly during exercise in each of the three treatments. They remained below the preexercise concentrations during recovery in the P treatment but increased significantly above the preexercise concentrations during the L and H treatments. By the end of the 4 h-recovery period, blood glucose and insulin were still significantly above the preexercise concentrations in both treatments. Muscle glycogen storage was significantly increased above the basal rate (P, 0.5 mumol.g wet wt-1.h-1) after ingestion of either glucose polymer supplement. The rates of muscle glycogen storage, however, were not different between the L and H treatments during the first 2 h (L, 5.2 +/- 0.9 vs. H, 5.8 +/- 0.7 mumol.g wet wt-1.h-1) or the second 2 h of recovery (L, 4.0 +/- 0.9 vs. H, 4.5 +/- 0.6 mumol.g wet wt-1. h-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗

Surgical treatment of supracristal type of ventricular septal defect.

Surgically treated ventricular septal defect (VSD) was of supracristal type in 120 of 389 Chinese patients; 93 of the 120 were younger than 15 years. Concomitant aortic anomalies were present in 58 of the patients (regurgitation in 23 and cusp prolapse in 35). Corresponding figures among the 93 patients of the under-15 group were 40 (9 + 31). Direct suture or patch closure of the supracristal VSD and replacement or plication of anomalous aortic valves were the methods used. The results of direct closure were equal to those of patch closure. One patient died of subacute bacterial endocarditis, which had been present preoperatively. There were no other deaths. The postoperative observation period was 6 months to 7 years. As the incidence of associated valvulopathy increases with patient age, early operation for supracristal VSD, regardless of shunt volume, is advocated.

Adolescent↗

Computerized quality control of radioimmunoassay in Korea.

Automated data processing and quality control of radioimmunoassays offer not only increased speed but also a more thorough and statistically rigorous analysis of results. An external quality assessment scheme for serum thyroxine, triiodothyronine and thyroid stimulating hormone (TSH) assays was performed in five nuclear medicine laboratories in Korea to compare with the assay performances of the World Health Organization Radioimmunoassay Program. The required radioimmunoassay kits were supplied through the International Atomic Energy Agency (IAEA). We have determined the weighted root mean squared error, and variance ratio as the indices of standard curve and also the average batch coefficient of variation (ABCV) as the parameters of response error relationship curve and precision profile. There was a good fit for the triiodothyronine assay, but 3 of 5 laboratories showed possible bad fit in the T4 and TSH assay systems. The ABCV was less than 5 percent for the T3 and T4 assay system, however for the TSH system, only 1 laboratory showed the ABCV value of less than 5 percent. We have also calculated the within batch variation (drift) and between laboratory variations.

Electronic Data Processing↗

Duration of occupancy of opiate receptors by naltrexone.

To determine the duration of blockade of mu-opiate receptors by naltrexone, we measured the binding of [11C]carfentanil in the brain of five normal volunteers with a positron radiation detection system before and 1, 48, 72, 120, and 168 hr after naltrexone administration. The half-time of blockade by naltrexone in the brain ranged from 72 to 108 hr which is greater than the fast plasma clearance components (4-12 hr) of naltrexone or its metabolite, beta-naltrexol, but corresponds well to the half-time of the terminal phase of plasma naltrexone clearance (96 hr). These results are consistent with the duration of the pharmacologic effects of naltrexone in response to heroin administration and indicate that 50 mg/day of oral naltrexone results in plasma levels in excess of that needed to saturate opiate receptors. This is the first example of the use of a simple dual-detector system with positron-emitting radioactive drugs to provide information regarding the duration of action of the drug on its specific receptor site. The plasma clearance half-time of a drug may not give an accurate reflection of the duration of action of the drug on a specific neuroreceptor site. Direct measurement of drug effects on recognition sites greatly extend current studies of pharmacokinetics.

Administration, Oral↗