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Biomedical subjects

C N Lee

Publications and source records attributed to C N Lee.

At least 127 records · Page 7Linked to original sources
PubMed1992

Early experiences of intra-operative trans-oesophageal echocardiography (TEE) in mitral valve repair.

Whenever possible Mitral valve repair should be performed instead of Mitral valve replacement. It is important to assess the adequacy of the repair during the operation so that any corrective steps may be taken immediately. We present three cases of Mitral valve repair in which the intraoperative TEE was used to assess the adequacy of the repair. There was good correlation of the immediate post bypass TEE findings and early post operative transthoracic echocardiographic findings. Intraoperative TEE is a useful tool in the early assessment of Mitral Valve Repair.

Adult↗
PubMed1992

Dietary fats and inflammatory bowel disease in Asians.

Chemically processed, hydrogenated fats, such as margarine, have been implicated in the aetiology of inflammatory bowel disease. Toxic by-products may occur in their production or during frying and cooking. A survey of dietary oil usage was conducted among Asians in Leicester, comparing inflammatory bowel disease patients with healthy controls. Two groups were comparable for age, sex, religion, place of birth, number of years spent in Britain and vegetarian status. There were no significant differences in actual oils used between healthy controls and patients with ulcerative colitis or Crohn's disease (chi 2 = 0.142 and 1.803 respectively, p greater than 0.50). However patients with Crohn's disease were found to recycle their cooking oil significantly more often than age and sex-matched colitics (p less than 0.05) and particularly age and sex-matched controls (p less than 0.01). A similar study needs to be conducted in India where the incidence of inflammatory bowel disease is low. If this difference is confirmed a programme of health education in cooking habits could lower the incidence of Crohn's disease.

Dietary Fats↗
PubMed1992

Purine modulation of prostaglandin F2 alpha (PGF2 alpha)-induced premature luteolysis in vivo in nonpregnant sheep.

In two separate experiments, control and PGF2 alpha-treated unilaterally ovariectomized ewes received vehicle or adenosine every four hours through an exteriorized catheter installed either to parafuse the ovarian vascular pedicle of the remaining ovary containing a corpus luteum (CL) or to infuse intrauterine ipsilateral to the remaining ovary with the CL. Infusions were given every four hours from day 7 through day 22 postestrus or until ewes returned to estrus. Chronic infusion of vehicle intrauterine or parafusion of the ovarian vascular pedicle with vehicle in PGF2 alpha-treated ewes shortened the interestrous interval compared to controls (P less than 0.05). However, chronic parafusion of the ovarian vascular pedicle with adenosine in PGF2 alpha-treated ewes prevented a PGF2 alpha-induced premature luteolysis (P less than 0.05) but not when adenosine was infused chronically intrauterine (P greater than 0.05). It is concluded that adenosine can block a PGF2 alpha-induced premature luteolysis in vivo and may have roles in regulation of luteal secretion of progesterone but it is probably not the embryonic antiluteolysin of early pregnancy in ewes.

Adenosine↗
PubMed1992

Ectopic thymoma: a case for median sternotomy for complete thymectomy.

Thymomas are normally found in the superior mediastinum or the upper part of the anterior mediastinum. We report a case of thymoma arising in the inferior aspect of the anterior mediastinum. This case illustrates that thymic tissue may be found low in the anterior mediastinum and supports the practice of a median sternotomy approach for thorough mediastinal exploration in all cases of thymectomy.

Aged↗
PubMed1991

Combined resection of hepatoblastoma and intracaval right atrial extension with profound hypothermia and circulatory arrest.

Hepatoblastoma is an uncommon liver neoplasm in children but its intraatrial extension through the inferior vena cava is extremely rare. The case described is a 3-year-old boy in whom profound hypothermia and circulatory arrest were used to resect a hepatoblastoma and its extension to the right atrium. This technique allows maximal resection and relief of venous obstruction from atrial extension of hepatoblastoma.

Carcinoma, Hepatocellular↗
PubMed1991

Haemodynamic effects of ketanserin following coronary artery bypass grafting.

The haemodynamic effects of ketanserin were studied consecutively in seventeen patients in the intensive care unit following coronary artery bypass grafting. Hypertensive patients (Group 1, systolic blood pressure (SBP) greater than or equal to 150 mmHg following discontinuation of nitroprusside, n = 10) received intravenous ketanserin 10 mg and infusion of 0.1 mg.kg-1.hr-1 with additional boluses as required to maintain SBP less than or equal to 130 mmHg for one hour. Non-hypertensive patients (Group 2, SBP less than 150 mmHg, n = 7) received a 5 mg bolus and the same infusion. Ketanserin significantly decreased arterial blood pressure (P less than 0.001) in all patients in Group 1. Heart rate was decreased but not significantly. Cardiac index, systemic and pulmonary vascular resistance and pulmonary shunt fraction were not significantly altered from pre-ketanserin values when blood pressure was controlled with nitroprusside. Normotensive patients in Group 2 did not show any undesirable hypotension or significant haemodynamic changes. Mean nitroprusside dose requirements following ketanserin therapy were significantly reduced by 91.6% in Group 1 and 78.4% in Group 2 (P less than 0.05). Ketanserin is effective in treating hypertension following coronary artery bypass grafting with an advantage of lack of reflex tachycardia.

Adult↗
PubMed1991

Isolation and typing of herpes simplex virus from clinical specimens collected at National Taiwan University Hospital, 1981-1990.

From 1981 to 1990, 10,167 clinical specimens were collected at National Taiwan University Hospital from the cases with suspected viral infections. Three hundred of herpes simplex virus (HSV) were isolated from these samples (isolation rate; 3.0%). One hundred and fifty-one strains were isolated from non-genital, and 149 strains from genital areas. HSV strains were typed by direct immunofluorescence staining technique. The type specific monoclonal antibodies were used in the test. Most of the HSV strains isolated from non-genital areas were type 1 (HSV-1) (147/151, 97.4%) whereas most of the strains from genital areas were type 2 (HSV-2) (140/149, 94.0%). All nine strains of HSV-1 isolated from genital areas were from female patients. The predominance of HSV-1 in non-genital area infections, and of HSV-2 in genital area infections, did not change during the ten years under review.

Female↗
PubMed1991

Antenatal ultrasonic findings of craniofacial malformations.

Fetal craniofacial malformations were identified sonographically in 13 cases. Holoprosencephaly and median cleft syndrome were the most frequent findings. Cleft lip, cleft palate, single nostril, cyclopia and hypotelorism were also seen. Seven of the 13 cases (54%) had polyhydramnios. Amniocentesis was performed on 12 fetuses, and 5 of them showed autosomal trisomy. Accordingly, when craniofacial malformation is recognized antenatally, a careful survey of the fetus for other associated structural anomalies and cytogenetic study are indicated to aid in diagnosis and subsequent obstetric and neonatal management. Also screening for fetal craniofacial malformation is recommended during mid-trimester ultrasound examinations.

Abnormalities, Multiple↗
PubMed1991

Oviductal vein resection affects pregnancy rates in sheep.

Progesterone is delivered locally via the oviductal vein to the cranial uterine horn ipsilateral to the ovary bearing the corpus luteum. Removal of the oviductal vein reduces this local delivery of progesterone. The objective of this experiment was to determine if local delivery of progesterone via the oviductal vein is necessary for embryo survival. Twenty-five nulliparous ewes were bred at estrus to fertile rams. On day 4 following breeding, ewes were randomly assigned to one of two treatment groups: oviductal vein resection (n = 11) or sham operated controls (n = 14). Following midventral laparotomy, the oviductal vein was isolated, ligated and removed. In the sham surgery control ewes, the oviductal vein was isolated, sutures were placed around the vein but were left unsecured. Following surgery, ewes were returned to the flock. Jugular venous blood samples were collected daily for 25 days after surgery and every third day until day 68 post breeding. On day 85 post breeding, ewes were laparotomized again to confirm pregnancy and location of the fetus. Blood samples were analyzed for progesterone via radioimmunoassay. The proportion of ewes pregnant in the oviductal vein resected groups were greater (p less than or equal to .08) than in the control, sham surgery group. Transuterine migration of embryos occurred in 2/4 pregnant, sham operated control ewes whereas migration occurred in 0/8 of the pregnant, oviductal vein resected ewes. Patterns of progesterone secretion differed (p less than or equal to .001) between pregnant and nonpregnant ewes across the entire sampling period. During maternal recognition of pregnancy, days 13 to 21 after breeding, overall mean jugular venous concentrations of progesterone were lower (p less than or equal to .05) in the oviductal vein resected ewes and patterns of secretion tended to differ (p less than or equal to .09) between oviductal vein resected and sham operated control ewes. It is concluded that oviductal vein resection increases pregnancy rates in nulliparous ewes and this may be due to a reduction in the local delivery of an inhibitor of embryo survival, possibly progesterone, or by maintaining the appropriate uterine environment conducive to a successful pregnancy.

Animals↗
PubMed1991

The purine adenosine amplifies the response to gonadotropins and inhibits prostaglandin F2 alpha (PGF2 alpha) suppression of gonadotropin stimulation of bovine luteal cells in vitro.

Dispersed bovine luteal cells collected on day 7 or 13 postestrus were incubated in vitro with human chorionic gonadotropin (hCG) or prostaglandins E1 or E2 (PGE1; PGE2) in the presence or absence of adenosine, dipyridamole and/or prostaglandin F2 alpha (PGF2 alpha). Secretion of progesterone by day 7 or 13 bovine luteal cells was increased by hCG, PGE1 or PGE2 which was increased further when co-incubated with adenosine (p less than 0.05). Adenosine alone increased secretion of progesterone by day 7 luteal cells (p less than 0.05) but not by day 13 luteal cells (p greater than 0.05). PGF2 alpha inhibited the gonadotropic response to hCG, PGE1 or PGE2 (p less than 0.05) which was reduced by adenosine (p less than 0.05) by day 7 or 13 bovine luteal cell suspensions. Dipyridamole reduced the adenosine-facilitated response to hCG, PGE1 or PGE2 by day 7 or 13 luteal cell suspensions (p less than 0.05). It is concluded that adenosine enhances the steroidogenic response by functional bovine luteal cells to hCG, PGE1 or PGE2 and that adenosine reduces the luteolytic response to PGF2 alpha by gonadotropin-stimulated bovine luteal cells in vitro.

Adenosine↗
PubMed1991

Myocardial revascularisation in patients with carotid artery disease.

From January 1987 to December 1989, 80 patients with carotid bruit and/or history of transient ischaemic attack/stroke underwent digital subtraction angiography (DSA) prior to consideration for coronary artery bypass graft. Thirty-eight patients (Group I) out of the 80 had coronary artery bypass graft done with postoperative stroke in five (13.2%); this contrasted with a group of 320 patients (Group II) without cerebrovascular disease who underwent coronary artery bypass graft during the same period with postoperative stroke in two cases (0.63%) (p less than 0.0005). Carotid artery stenosis was noted on the DSA in 66% of Group I patients, with significant disease (greater than 70% occlusion) in 15%, while the study was normal in 34% of cases. Combined carotid endarterectomy and coronary artery bypass graft was done in five of Group I patients, with postoperative stroke in one; this was the only one among the stroke patients with significant carotid disease. All strokes, except in one patient, resolved within one to 6 1/2 months. These results suggest that the risk of stroke after coronary artery bypass graft is increased in patients with carotid bruit or history of transient ischaemic attack/stroke and in the presence of established carotid artery disease. The place of combined carotid endarterectomy and coronary artery bypass graft in these cases remains to be determined.

Angiography, Digital Subtraction↗
PubMed1991

Assessment of ventricular septal defect by colour flow mapping.

The purpose of this study was to evaluate the usefulness of colour flow mapping (CFM) in the diagnosis and classification of congenital ventricular septal defect (VSD) and in the confirmation of spontaneous and surgical closure. Between August 1988 and March 1990, a total of 102 patients with isolated VSD (82 preoperative and 20 postoperative), age ranging from one day to 14 years, were subjected to 176 echocardiographic examinations. Sequential cross sectional imaging and CFM were the main modalities of assessment with conventional Doppler interrogation for quantitative measurements. In the preoperative group, there were 56 (68.3%) perimembranous (pm) VSD, 14 (17.1%) muscular (m) VSD and 12 (14.6%) doubly committed subarterial (dcsa) VSD. Ventricular septal defect was detected by CFM only in 88.9% of m/VSD, 57.6% of dcsa/VSD and 11.8% of pm/VSD (p less than 0.01). Spontaneous closure rate was highest in m/VSD (28.6%) followed by pm/VSD (8.9%) (p = 0.05). None of the dcsa/VSD closed as assessed by CFM. In the postoperative group, CFM served to quickly confirm complete closure without residual left to right shunt in 20 patients. In addition, CFM was useful in the assessment of haemodynamics and flow directed Doppler interrogation. Hence, CFM is a useful adjunct to cross sectional imaging in the assessment of children with isolated VSD.

Adolescent↗
PubMed1990

Rapid laboratory diagnosis of human cytomegalovirus infection using monoclonal antibody.

The monoclonal antibody E. 13, recognized an early nonstructure antigen (68 KD) of human cytomegalovirus (HCMV), was used for early detection of HCMV in cell cultures. The virus antigen could be detected by the indirect immunofluorescence staining (IF) technique 6 hours after inoculation of HCMV AD169 and NTUH871233 strains into human embryonic lung fibroblast (HELF) cells growing in shell vials prepared by low speed centrifugation (700xg) at 25 degrees C for 1 hour. The intensity of fluorescence reached a peak 14 hours after virus inoculation and remained at the same level for 72 hours. The feasibility of application of this technique for rapid detection of HCMV in the clinical virology laboratory was tried. A total of 201 urine specimens requesting HCMV isolation were inoculated into HELF cells using the shell vial culture method. The virus growth in the shell vial cultures was detected by the indirect IF technique with the monoclonal antibody E.13 at 16 to 18 hours postinoculation. The results obtained were compared with those of the conventional tube culture method. The sensitivity and specificity of the test vs the conventional tube culture method for detection of HCMV in clinical specimens were 93.06% and 99.22%, respectively. The average time of virus isolation by the conventional culture method was 10.9 days, whereas final results with the shell vial culture method were obtained in only one day. The above results indicate that detection of HCMV early antigen in infected cells with monoclonal antibody E.13 is a sensitive and reliable method for rapid diagnosis of HCMV infections.

Antibodies, Monoclonal↗
PubMed1990

Current issues in heart transplantation.

Dramatic advances in heart transplantation have been made in the last decade. It is now a standard treatment option for end stage cardiac disease. There is tremendous potential for research and advances in the areas of heart transplantation, heart-lung transplantation, mechanical assist devices and the artificial heart. A few issues of current interest in heart transplantation are selected for discussion.

Follow-Up Studies↗
PubMed1990

The role of protamine dose assay in reversal of heparin following extracorporeal circulation for open heart surgery.

The amount of protamine required for the neutralisation of heparin following cardiopulmonary bypass was determined by a Protamine Titration Assay using the principle of the dose--response curve and the patient's estimated blood volume. In 300 open heart surgery patients, infusion of the determined dose of protamine normalised the Activated Clotting Time (ACT) to baseline levels in 97% of these patients and produced adequate hemostasis. Our present study showed that the dose of protamine dropped to 75% of the dose calculated by conventional method of heparin to protamine ratio of 1:1. This had minimised the adverse effects of excessive protamine administration and optimised coagulation control after extracorporeal circulation.

Adolescent↗
PubMed1989

Progesterone in uterine and arterial tissue and in jugular and uterine venous plasma of sheep.

Concentrations of progesterone in uterine and arterial tissue and in uterine and jugular venous plasma were determined. Blood was collected on Days 4 and 9 postestrus from the jugular vein and the first and last venous branches draining each uterine cornu; uterine tissue and arteries were subsequently collected. Progesterone was greater (p less than 0.05) in the cranial third than in the middle or caudal thirds of the uterine horn adjacent to the corpus luteum (CL)-bearing ovary or in any third of the contralateral horn. Progesterone in uterine arterial segments adjacent to the CL-bearing ovary was higher (p less than 0.05) than in contralateral segments. Progesterone was higher (p less than 0.05) in blood from the first venous branch of the cranial third of the uterine cornu adjacent to the ovary with the CL, than in the last branch of the caudal third, or contralateral horn, or in jugular blood. When oviductal veins were resected on Day 9 postestrus, progesterone in the first vein draining the cranial third of the uterine cornu adjacent to the CL-containing ovary was not different (p greater than 0.05) 48 h after resection than in the same vessel in the opposite horn or in jugular blood. We concluded that progesterone and other ovarian products may be delivered to the uterus locally.

Animals↗