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Biomedical subjects

C R Hung

Publications and source records attributed to C R Hung.

At least 55 records · Page 3Linked to original sources
PubMed1993

Plasma endothelin levels and surgically correctable pulmonary hypertension.

To know the changes in plasma endothelin of patients with pulmonary hypertension, we studied 32 patients with valvular heart disease. Among them, 22 patients had pulmonary hypertension (group I) and 10 had pulmonary arterial pressures in the normal range (group II). Plasma endothelin-1 concentrations of the patients in group I were significantly greater than those of the patients in group II (p < 0.05). No significant difference in plasma endothelin-3 concentrations existed between the two groups. Cardiac output and pulmonary capillary wedge pressure had a linear correlation with plasma endothelin-1 levels. There was also a significant correlation between plasma endothelin-1 levels and hemodynamic indicators of severity of pulmonary hypertension, such as mean pulmonary arterial pressure and pulmonary vascular resistance (p < 0.05). All patients in this study underwent surgical procedures for the correction of valvular lesions. All patients in group I showed a decrease in pulmonary arterial pressures, and their plasma endothelin-1 levels decreased from 3.84 +/- 0.20 pg/mL to 1.66 +/- 0.07 pg/mL (p < 0.05), whereas the plasma endothelin-3 levels had only slight variation from 0.64 +/- 0.11 pg/mL to 0.75 +/- 0.06 pg/mL (p > 0.05) between the preoperative and the postoperative stages. The results demonstrated that plasma endothelin-1 rather than endothelin-3 had a role in pulmonary hypertension. Several pieces of evidence pointed out that endothelin-1 functioned as a reactive mediator during vasoconstriction in the case of pulmonary hypertension rather than as a triggering factor of pulmonary hypertension.

Adolescent↗
PubMed1993

Infundibular pulmonic stenosis with intact ventricular septum: a report of 15 surgically corrected patients.

Infundibular pulmonic stenosis with intact ventricular septum of primary origin is an uncommon condition. We report 15 such patients (nine males and six females, aged 7-36 years) who had undergone surgical correction for the anomaly during the period between 1975 and 1992. The occurrence of this clinical setting represents 0.19% (15/7826) of all cardiac operations and 0.46% (15/3222) of congenital heart diseases undergoing surgical correction during that period of time. The lesion was of discrete fibromuscular hypertrophy of the infundibulum in all 15 patients. The presenting symptoms of most patients were exertional dyspnea and syncope; however, five patients with severe obstruction were asymptomatic. The peak systolic pressure gradient across the infundibulum ranged from 71 to 230 mmHg. There was only one operative death; the remainder had remained well following the surgery over a mean follow-up period of 35 months. Surgical correction for infundibular pulmonic stenosis is rewarding in the absence of heart failure.

Adolescent↗
PubMed1993

Plasma endothelin level changes during hemorrhagic shock.

The purpose of this study was to analyze changes in plasma endothelin-1 levels during hemorrhagic shock. Thirty-two mongrel dogs were divided into four equal groups with group I as the controls and groups II through IV as experimental groups. The dogs in the experimental groups underwent hemorrhagic procedures. The mean blood pressure was kept at the level of 65 mm Hg in group II, 50 mm Hg in group III, and 40 mm Hg in group IV. Blood samples were collected from each dog under the following conditions: (1) after induction of anesthesia, when the animals were hemodynamically stable, before the start of shock; (2) 1 minute after the mean arterial pressure dropped to the level designed for each group (shock 1); (3) 15 minutes after shock 1; (4) 30 minutes after shock 1; (5) 1 hour after shock 1; (6) 2 hours after shock 1; (7) 4 hours after shock 1; and (8) 8 hours after shock 1. Plasma endothelin-1 levels both in arterial and venous blood were analyzed in each dog. The results showed that (1) arterial endothelin-1 concentrations were considerably lower than venous concentrations at the baseline level; (2) after the shock-1 point, plasma endothelin-1 concentrations increased, first markedly and then evenly throughout the oligemic period; (3) elevation of plasma endothelin-1 levels was significantly linearly correlated with the amount of blood loss at the time of 2 hours after shock and thereafter; (4) the arterial/venous ratio of plasma endothelin-1 levels during the oligemic period was higher than that in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Traumatic rupture of the pericardium with a peculiar chest radiographic finding.

A 46-year-old man was admitted because of progressive exertional dyspnea and pulsating neck vein for 3 years. He had a history of car accident with his chest struck by the steering wheel 10 years previously. Physical checkup and laboratory studies revealed severe tricuspid regurgitation. The chest radiography disclosed mild cardiomegaly and shift of the heart towards the left hemithorax with a bizarre cardiac silhouette showing double contour over the left ventricular border, suggesting the possibility of partial absence of the left pericardium. The latter diagnosis was confirmed at open heart surgery for the associated severe tricuspid regurgitation.

Accidents, Traffic↗
PubMed1993

Comparison between the effects of crude saikosaponin and 16, 16-dimethyl prostaglandin E2 on tannic acid-induced gastric mucosal damage in rats.

Hung, C.R., T.S. Wu and T.Y. Chang. The comparison between the effects of ethanol-extracted saikosaponin (SS) and 16, 16-dimethyl prostaglandin E2 (dmPGE2) on gastric acid back diffusion and mucosal damage induced by 100 mg/kg of acidified tannic acid (tannic acid dissolved in 100 mm HCl + 54 mM NaCl solution) was studied in the vagotomized rat. Crude saikosaponin (500 mg/kg) given by intragastric irrigation (I.G.) produced a significant inhibition (p < 0.05), while dmPGE2 (100 micrograms/kg) provoked a significant increase (p < 0.05) in acid back diffusion induced by acid solution. When graded doses of SS (100-1000 mg/kg) were added to acidified tannic acid solution and instilled to the stomach, a dose-dependent inhibition in acidified tannic acid-induced mucosal ulceration and acid back diffusion was achieved. The decrease in the H+ concentration and the increase in the Na+ concentration in the final samples induced by acidified tannic acid were also significantly (p < 0.05) inhibited by the same doses of SS. However, neither intraduodenal (I.D.) nor intravenous (i.v.) administration of SS was effective in inhibiting these ulcerogenic parameters. When dmPGE2 (3-100 micrograms/kg) was given concomitantly with acidified tannic acid solution, the acid back diffusion as well as mucosal ulceration provoked by acidified tannic acid were not significantly improved. The volume of luminal contents but not electrolyte concentrations in the final sample was considerably increased by adding dmPGE2 to the acidified tannic acid solution. The failure of I.D. or i.v. of dmPGE2 in inhibiting tannic acid-induced acid back diffusion and mucosal ulceration was also observed in other series of experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

16,16-Dimethylprostaglandin E2↗
PubMed1993

Effect of pH on endothelin-1 secretion of aortic strips.

In this study, aortic strips taken from mongrel dogs were used as experimental material. After preparation, the aortic strips were incubated in a designed control medium or an experimental medium (adding thrombin or epinephrine to the control medium). The pH value of each incubation medium mentioned above was adjusted with HCl or NaOH to a level of 8.0, 7.4, 7.0 and 6.6, respectively, in order to investigate the influence of medium acidity on the production of endothelin-1 from endothelial cells using aortic strips. After a designated time duration (one hour, three hours, six hours and 12 hours, respectively), the incubation media were collected for assay of endothelin-1. The results demonstrated that the endothelin-1 level of the incubation medium was elevated when: 1) the incubation time was lengthened; 2) the incubation medium was more acidic; 3) the aortic strips were incubated with a stimulant, such as thrombin and epinephrine; and 4) the endothelial cells on the aortic strips were intact. This indicates that the secretion of endothelin-1 is: 1) time-dependent, 2) pH-dependent, 3) stimulant-dependent and 4) endothelium-dependent.

Animals↗
PubMed1993

Surgical treatment of infantile cardiac tumor: report of a case.

We herein report on a male infant who was diagnosed as having a cardiac tumor at the age of four days. This baby was quite well after birth, with the exception of a heat murmur heard by the pediatrician in a routine physical examination. Echocardiograms disclosed a tumor located in the muscular portion of the interventricular septum, almost occupying the whole right ventricular chamber. The patient underwent near total excision of the tumor to relieve the right ventricular outflow obstruction when he was 54 days old. The pathologic report revealed a rhabdomyoma.

Heart Neoplasms↗
PubMed1992

Surgical implications of juxtaposed atrial appendages and the associated anomalies.

Juxtaposition of the atrial appendages (JAA) is an uncommon anomaly of the heart that is frequently associated with other cardiac abnormalities, such as transposition of the great arteries and tricuspid atresia. We encountered 7 patients with JAA from July 1984 to July 1989 at National Taiwan University Hospital. The JAA was right-sided in 1 patient and left-sided in 6. The patients' ages ranged from 10 months to 12 years. The cardiac anomalies in the patient with right JAA were double-outlet right ventricle and ventricular septal defect, which was repaired with a patch. Of the 6 patients with left JAA, 5 had transposition of the great arteries, and in 3 of them obstructive tricuspid lesions (tricuspid stenosis in 1, tricuspid atresia in 2) were noted. Three patients with left JAA and normal tricuspid valve underwent total correction (one Senning operation and two Rastelli operations). The other 3 patients with tricuspid obstruction underwent total cavopulmonary connection (2) and Fontan operation (1). We concluded that, first, left JAA was more frequently seen and associated with more morbid anatomy than right JAA. Second, if left JAA is discovered in planning biventricular repair for transposition of the great arteries, the tricuspid valve should be inspected carefully to rule out tricuspid obstruction.

Child↗
PubMed1992

T lymphocyte changes in open heart surgery.

To investigate the effect of open heart surgery on T lymphocytes and their subpopulations, 20 patients, who had undergone moderate- to high-dose fentanyl anesthesia and a cardiopulmonary bypass (CPB), were studied using flow cytometry techniques and monoclonal antibodies during and after surgery. The ages of these patients ranged from four to 61 years with eight being male and 12 being female. The disease entity consisted of four with coronary, six with congenital and 10 with valvular heart disease. No cyanotic patients were included in this study. Peripheral blood samples were collected before anesthesia, immediately before the surgical incision, on the first postoperative day (POD1) and on the second postoperative day (POD2), respectively. We found no significant changes in the percentage of total T cells (T3), or helper (T4) and suppressor (T8) T cells during anesthesia before the surgical incision. On POD1, all T lymphocyte subset percentages decreased significantly when compared to pre-operative values (total T cells: 58.4 +/- 12.6 vs 24.4 +/- 8.4, helper T cells: 33.3 +/- 10.1 vs 15.4 +/- 6.3, suppressor T cells: 23.0 +/- 6.4 vs 10.0 +/- 4, all p less than 0.001) but returned to preoperative levels on POD2. Throughout the study period, there were no significant changes in the T helper cell to T suppressor cell ratio. In spite of the transient decrease in T lymphocytes and their subpopulations, no clinical evidence of infection was noted in any patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Effects of fibrin glue on hemostasis.

In order to decrease complications following incomplete hemostasis, we tried to make a safe, efficient and highly concentrated fibrin glue by thawing single-donor fresh frozen plasma. Using a unique animal model, in which arterial bleeding was created, fibrin glue and some related hemostatic agents were tested to evaluate their hemostatic effectiveness. The results demonstrated that: 1) the concomitant use of cryoprecipitate-thrombin tissue glue with adjuvant (aprotinin or calcium chloride) had a better hemostatic effect than the use of cryoprecipitate-thrombin tissue glue alone (p < 0.05); 2) impregnation of fibrin glue with a suitable vehicle was advisable to accelerate the coagulation plug formation and to enhance the mechanical strength of the adhesive plug; 3) Gelform, used as a vehicle to hold the fibrin glue, had a more efficient hemostatic effect than gauze, collagen fleece and Surgicel (p < 0.05); 4) systemic heparinization attenuated the effectiveness of the hemostatic agents and aggravated the bleeding problem, but a low hematocrit level did not; 5) fibrin glue had its own limitations, especially under systemic heparinization, on hemostatic effectiveness in a high-pressure system. Understanding the characteristics of fibrin glue, as mentioned above, definitely improved the hemostatic effectiveness of the glue, especially after failure of the usual methods of controlling bleeding.

Animals↗
PubMed1992

Open heart surgery in geriatric patients.

With the progress of medical science, the scope of open heart surgery has expanded. From 1975 through 1987, we operated on 114 consecutive patients aged 65 years and over with the aid of a cardiopulmonary bypass in the Department of Surgery, National Taiwan University Hospital. The annual number of these elderly patients has increased gradually, reaching 6.4% of the annual open heart cases in 1987. Eighty-six of our 114 patients were males and 28 were females. Their ages ranged from 65 to 88 years with an average of 68.5 years. Overall, 65 patients (57%) were operated on for coronary artery disease and/or its associated lesions; 41 (36%), for valvular heart disease; six, for aortic dissection; two, for cardiac tumor; and one, for congenital pulmonary stenosis. One patient had combined coronary artery disease and aortic dissection. The mortality for isolated coronary artery bypass surgery was 12%; for single valvular surgery it was 11%. The complexity of the surgical procedure increased the operative mortality. The overall mortality was 23.6% (27/114), with subsequent death in 5.7% during an average of 25 months of follow-up. Because of the degeneration of organ-systems in elderly patients, and its frequent association with poor cardiac reserve and other medical problems, these elderly cardiac patients should be checked thoroughly before they are considered for open heart surgery. Our experience suggests that open heart surgery can be done in selected patients aged 65 years or older with acceptable risks. Age alone should not be an absolute contraindication to surgery, and clinical improvement is to be expected after surgery.

Age Factors↗
PubMed1992

The role of endothelin-1 during ischemia-reperfusion injury.

In order to investigate the role of endothelin-1 during ischemia-reperfusion injury, 80 adult male Wistar rats were subjected to three hours of ischemia and one hour of reperfusion. Animals were evenly divided into eight groups. The rats in group 1 served as the normal control group, while the rats in group 2 received an intravenous infusion of endothelin-1 in a dosage of 0.5 ng/kg/min, group 3 in a dosage of 5 ng/kg/min, and group 4 in a dosage of 50 ng/kg/min. The rats in group 5 were infused with angiotensin II (10 ng/kg/min). The rats in group 6 received an intravenous infusion of 10,000 units of superoxide dismutase and 10,000 units of catalase. Group 7 rats were infused with endothelin-1 (50 ng/kg/min), superoxide dismutase (10,000 units), and catalase (10,000 units). Group 8 rats received an infusion of angiotensin II (10 ng/kg/min), superoxide dismutase (10,000 units) and catalase (10,000 units). The infusions were given during the reperfusion period. After one hour of reperfusion, the gastrocnemius and soleus muscles of the experimental animals were excised and assayed for ischemia-reperfusion injury by measuring triphenyltetrazolium chloride (TTC) reduction. The results showed that the limb activity of the ischemic extremity was 40.33 +/- 2.75% in group 1, 41.62 +/- 4.08% in group 2, 14.42 +/- 3.14% in group 3, 4.43 +/- 1.05% in group 4, 23.81 +/- 3.51% in group 5, 57.23 +/- 4.52% in group 6, 31.79 42- 3.63% in group 7, and 27.39 +/- 3.95% in group 8. Endothelin-1 reduced the limb activity in a dose-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Total cavopulmonary connection for surgical treatment of complex congenital heart disease.

Diversion of vena caval flow directly into the pulmonary circulation--total cavopulmonary connection--has been tried at our hospital for two years as an alternative to the modified Fontan procedure for surgical treatment of complex congenital heart disease other than tricuspid atresia in 26 cases with six operative mortalities. The causes of death were low cardiac output in four, uncontrollable paroxysmal supraventricular tachycardia in one and airway obstruction in one. Except for one late death which occurred three months after surgery due to sepsis, the 19 patients who survived the operation were followed up for four to 27 months (mean 15 months). All of them improved clinically (NYHA Class 1). Graded bicycle exercise tests were performed in five of them at three to 12 months after surgery, and their exercise tolerance was comparable to that of patients with an atriopulmonary connection. In conclusion, total cavopulmonary connection is an acceptable alternative to the modified Fontan operation for surgical treatment of complex congenital heart disease, although longer follow-up is necessary.

Adolescent↗
PubMed1992

Hyperamylasemia following cardiopulmonary bypass.

In order to study the occurrence of postbypass hyperamylasemia, 75 patients undergoing cardiopulmonary bypass (CPB) were studied from March 1989 to January 1990. There were 49 males and 26 females. Among them, 27 had congenital heart disease, 30 had valvular disease, and 18 had coronary artery disease. There were 27 patients with at least one elevated serum amylase sample after operation. Thus, the overall incidence of hyperamylasemia was 36%. As compared with the preoperative data (1.3%), there was a statistically significant difference in the occurrence of hyperamylasemia (p less than 0.05). Three patients had overt clinical pancreatitis postoperatively. There was no positive correlation between the serum amylase level and the occurrence of pancreatitis (p greater than 0.05). Forty-two cases had a significant elevation of the amylase creatinine clearance ratio (ACCR) after CPB. However, there was no significant difference between the groups with pulsatile and nonpulsatile CPB (p greater than 0.05). Three patients (4%) died in our series. The causes of death were heart failure in two and fulminant pancreatitis associated with low cardiac output in one. Although our experience in dealing with pancreatitis improved survival, mortality was still high (33.3%) in our series. Nevertheless, there was no apparent correlation between mortality and postbypass hyperamylasemia (p greater than 0.05). Logistic regression analysis was used to analyze the risk factors of the occurrence of hyperamylasemia, and the analysis revealed that patients with coronary artery disease were susceptible to postbypass hyperamylasemia. Our studies indicate that the use of total serum amylase or ACCR to monitor for the occurrence of pancreatitis in postbypass patients is inadequate.(ABSTRACT TRUNCATED AT 250 WORDS)

Amylases↗
PubMed1991

Protective effect of cimetidine on tannic acid-induced gastric damage in rats.

The effect of cimetidine on the acidified tannic acid-induced back diffusion of gastric acid and mucosal damage was investigated in the vagotomized rat. After intragastric irrigation for 1 to 3 h, tannic acid (20-500 mg kg-1) produced a dose-related increase in gastric volume and the loss of luminal H+. The change of mucosal permeability to the electrolyte, either the loss of H+ or the gain of Na+, K+, and Ca2+, induced by tannic acid was significantly diminished by the combination with intragastric cimetidine. However, intravenous injection of cimetidine did not protect this damage and back diffusion of acid neutralized intragastric cimetidine did not reduce the back diffusion of acid and Na+, K+, and Ca2+ output provoked by acid solution. Thus, the neutralizing action of cimetidine seems responsible.

Animals↗
PubMed1991

Atypical myxoma.

We report the case of a 38-year-old woman with a large thin-walled cystic mass (6 x 5 x 4.5 cm) filled with arterial blood in the right atrium. The cystic mass with blood content was clearly delineated by transesophageal cross-sectional echocardiography and magnetic resonance imaging of the heart. At operation, a silver-whitish, smooth surfaced cystic mass was found attached to the free wall of the right atrium between the superior vena cava and the right atrial appendage with a broad base. Microscopically, the wall of the cyst was composed of stellate mesenchymal cells embedded within a myxoid matrix which was proved by alcian blue stain. To our knowledge, this type of cardiac myxoma has not been previously reported.

Adult↗