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Biomedical subjects

P J Lin

Publications and source records attributed to P J Lin.

At least 73 records · Page 4Linked to original sources
PubMed1997

The role of Src kinase in the potentiation by ethanol of cytokine- and endotoxin-mediated nitric oxide synthase expression in rat hepatocytes.

This study demonstrates that exposure of primary rat hepatocytes or mouse BNL Cl.2 liver cell line to ethanol causes potentiation of tumor necrosis factor-alpha (TNF-alpha)- and lipopolysaccharide (LPS)-stimulated nitrite accumulation. The potentiating effect of ethanol (0.02-2 mM) appears to be time and concentration dependent. Consistent with nitrite production, the amount of inducible nitric oxide synthase (iNOS) mRNA and protein is initially detected at 4 hr after treatment with TNF-alpha/LPS/ethanol. Furthermore, the capability of these agents to induce iNOS expression is primarily determined by the age of the animals. Interestingly, antioxidants such as N-acetylcysteine (NAC), ascorbic acid, or alpha-tocopherol fail to inhibit TNF-alpha/LPS/ethanol-induced increase in iNOS protein. In addition, several kinase inhibitors, including staurosporine, genistein, curcumin, and herbimycin A, were used to examine their effects on this induction. Among them, only herbimycin A potently inhibits the accumulation of nitrite and iNOS expression. In vitro kinase assay verifies that Src tyrosine kinase is rapidly activated with a peak at 1 hr after treatment with TNF-alpha/LPS/ethanol but is not activated by these agents singly or doubly. As expected, herbimycin A can block Src kinase activity under circumstances in which iNOS expression is also inhibited. However, our results do not indicate that the mitogen-activated protein kinase is activated after treatment with these agents. The study results suggest that Src tyrosine kinase plays a prominent role in transducing the signal to induce iNOS expression in hepatocytes treated with TNF-alpha/LPS/ethanol.

Animals↗
PubMed1997

Cardiac tamponade in Taiwan.

We retrospectively reviewed all of the patients who were treated for cardiac tamponade at Linkou Chang Gung Memorial Hospital between January 1991 and December 1995. There were a total of 112 patients (57 males, 55 females) with a mean age of 51 +/- 14 years (53 +/- 15, 49 +/- 13, respectively). Dyspnea was the most common complaint (85%). The mean blood pressure was 129 +/- 24/78 +/- 17 mmHg, and only 8% had a systolic blood pressure of less than 90 mmHg. Sinus tachycardia was the most frequent electrocardiographic finding (72%, 62/86). Diffuse low voltage was noted in 35% (30/86) of the patients and electrical alternans was seen in 17% (15/86). The mean volume of pericardial effusion was 610 +/- 263 ml. Sixty-five percent of the pericardial effusions were bloody, 31% were serosanguineous, 2% were purulent and 2% were chylous. Overall, 54.5% of the patients had malignant diseases. Of the 61 patients who died, 79% had malignancies. Thirty-five (57%) of these 48 patients had lung cancer. The mean survival time from emergent pericardiocentesis was 3.4 months. In conclusion, non-traumatic cardiac tamponade had a poor prognosis because most patients had malignant etiologies. There is still no definitive treatment for recurrent malignant pericardial effusion-induced cardiac tamponade. Percutaneous pericardiocentesis as clinically required may be the most appropriate treatment, since it is questionable whether such subjects should be subjected to the unnecessary pain and suffering associated with an operative procedure, considering their short mean survival time.

Adolescent↗
PubMed1997

An alternative technique in the management of bullous emphysema. Thoracoscopic endoloop ligation of bullae.

STUDY OBJECTIVES: With the improvements in video-assisted thoracoscopic surgery, more older patients and patients with respiratory impairments are undergoing bulla ablation using new and costly technology. We evaluated the cost-effective technique of thoracoscopic endoloop ligation of bullae in patients with bullous emphysema. PATIENTS: From March 1992 through January 1996, 79 advanced age (mean age, 64 years) and oxygen dependency patients underwent thoracoscopic procedure using endoloop ligation for treatment of bullous emphysema. Clinical data were collected from chart review. Only patients with radiographically confirmed diagnosis of bullous emphysema were included in this evaluation. Thoracoscopic endoloop ligation of bulla was carried out under general anesthesia with double-lumen endotracheal tube and single-lung ventilation. RESULTS: Sixty-five patients (82%) exhibited subjective improvement in their symptom status at 3-month follow-up (from grade 2 or 3 to grade 1 or 2) according to the Modified Medical Research Council dyspnea scale. The mean duration of chest drainage was 6 days (range, 4 to 16 days). Average hospital stay was 9.5 days (range, 5 to 26 days). There was no postoperative death. A comparison of preoperative and postoperative functional evaluation was available in only 16 patients who showed an increase in FEV1 (from 0.85 to 1.02 L) and a decline in residual volume after operation. Complications include persistent airleak over 10 days in seven patients (8.9%), wound infection in three patients, and localized empyema in two patients. There was no recurrence after a mean follow-up of 21 months. CONCLUSION: These encouraging results have shown that thoracoscopic endoloop ligation of bulla has proved to be a safe, reliable, and cost-effective technique for bullous emphysema. With careful preoperative evaluation and meticulous postoperative care, many patients could be rehabilitated by endoloop litigation of the bullae.

Cost-Benefit Analysis↗
PubMed1997

Thrombectomy for left ventricular protruding thrombi in a patient with dilated cardiomyopathy.

Left ventricular thrombus is one source of cardiogenic embolism. The protruding, mobile type is the highest risk subgroup but is rarely encountered. Thrombectomy is one choice of therapy, and variously recommended based primarily on the experience with myocardial infarction. We report a rare case of successful left ventricular thrombectomy for two protruding, mobile thrombi in a patient with idiopathic dilated cardiomyopathy in order to prevent repeat embolization.

Adult↗
PubMed1997

Home-made endoloops for bullous lung disease: a case report.

Various surgical techniques for bulla ablation have been used since the introduction of video-assisted thoracoscopic surgery. Endoscopic stapler resecting (Endo-GIA) is now the most common procedure for bulla ablation. Other endoscopic techniques include bulla suturing, clipping, laser ablation and electrocauterization. We present here a select report on using a "home-made" endoloop on a patient with bullous lung disease. No intraoperative morbidity was attributable to the procedure. The operating room time was 110 minutes, and ventilator support was given for 18 hours. The chest tube was removed on day 7 and the patient discharged on the ninth postoperative day uneventfully. The patient exhibited subjective improvement in his symptom preceptions during an one-month follow-up examination. A comparison of pre- and post operative functional evaluation showed increase in FEV1 (from 0.45 L to 1.02 L) during 3-month follow-up. From our experience, thoracoscopic home-made endoloop ligation is a safe and cost effective means of volume reduction surgery for bullous emphysema that interferes with optimum function of the adjacent lung parenchyma.

Aged↗
PubMed1997

Internal iliac artery aneurysmo-rectal fistula associated with multiple aortoiliac aneurysms.

Fistular communication between an internal iliac artery aneurysm and rectum presenting as massive lower gastrointestinal tract bleeding is a rare entity in clinical practice. Prompt diagnosis and experienced therapeutic application determine the outcome. Herein we report the successful management of such a complication. A 68-year-old male had multiple aneurysms over the abdominal aorta and bilateral iliac arteries. It was the largest aneurysm arising from the right internal iliac artery which ruptured into the rectum and resulted in massive hematochezia. After extraanatomical bypass with right axillo-femoral and femoro-femoral crossover grafts to restore the circulation to the bilateral lower limbs, the infrarenal abdominal aorta just immediately above the proximal aneurysm was transected and closed as a blind stump. All the aneurysms were included in this resection and as much of the infected aneurysm tissue was debrided as possible. The rectum was exteriorized using Hartmann's procedure. The patient survived the operation and was discharged in good condition.

Aged↗
PubMed1996

Prolonged circulatory arrest in moderate hypothermia with retrograde cerebral perfusion. Is brain ischemic?

BACKGROUND: Circulatory arrest (CA), which provides a bloodless field and good visualization without the need of aortic cross-clamp, is commonly used to facilitate repair of aortic lesions. However, extended periods of CA may impair cerebral metabolism and cause ischemic injury. Studies were performed to evaluate the efficacy of retrograde cerebral perfusion (RCP) in protecting the brain from ischemic injury during a prolonged period of CA in moderate hypothermia. METHODS AND RESULTS: Twenty-three patients (18 men and 5 women) were operated on for aortic lesions (17 acute type A aortic dissection and 6 chronic type A aortic dissection with Marfan's syndrome). The aortic operations were performed with CA (58 to 104 minutes; mean +/- SD, 75 +/- 12 minutes) at a rectal temperature of 23.3 +/- 0.5 degrees C (21 degrees C to 25 degrees C). For RCP, cold (14 degrees C to 18 degrees C) oxygenated blood (300 mL/min) was pumped to the superior vena cava with internal jugular venous pressure of 15 +/- 5 mm Hg. The cardiopulmonary bypass time was 157 +/- 18 minutes. Cortical blood flow during RCP detected by subdural laser Doppler probe was 10 +/- 5% of baseline. Percent oxygen extraction and pyruvate and lactate levels (26 +/- 2% and 0.43 +/- 0.17 and 45 +/- 16 mg/dI) were insignificantly different from those before CA (28 +/- 3% and 0.71 +/- 0.08 and 62 +/- 20 mg/dL, P > .05). Creatine kinase-BB isoenzyme was undetectable. All but 1 patient survived the operation (95.5%) and woke up without neurological deficit. Follow-up (mean, 13 months) was complete in all survivors. There were no late deaths. Cerebral functional studies performed 3 months after discharge showed results insignificantly different from those of the normal control subjects. CONCLUSIONS: There is no evidence of ischemia of the brain during prolonged moderate hypothermic CA with the aid of RCP. Retrograde cerebral perfusion effectively extends the safe time of CA. Deep hypothermia during CA seems unnecessary.

Adult↗
PubMed1996

The endothelium-dependent response of human hepatic artery after preservation with the UW solution.

The University of Wisconsin's (UW) solution has been used commonly for current liver transplantation. However, its effect on the vascular endothelium remains unclear. Experiments were designed to study the effects. Human hepatic arteries harvested from patients with hepatocellular carcinoma undergoing liver resection were preserved in 4 degree C physiological solution (group 1, the content showed on the text) and UW solution (group 2) for 1 hr. Segments of preserved and control (group 3) hepatic arteries were suspended in organ chamber to measure the isometric force. The relaxations to acetylcholine (ACH) and adenosine diphosphate in segments of hepatic artery with endothelium were significantly greater than those segments without endothelium. The maximal relaxation to ACH in arterial segments with endothelium of group 2 was significantly different from those of group 1 and 3 (group 1 to group 3, 82 +/- 2%, 57 +/- 6%, and 83 +/- 4% of the initial tension contracted by neoepinephrine (3 X 10-7 mole/l, P < 0.05). The maximal relaxation to adenosine diphosphate was similar to the response to ACH. Perfusate hypoxia (oxygen tension 30 +/- 5 mmHG) caused endothelium-dependent contraction of the arterial segments (group 1 to group 3, 233 +/- 32%, 276 +/- 35%, and 251 +/- 40% of the initial tension, P < 0.05). Endothelium-independent relaxation and contraction of human hepatic artery to sodium nitroprusside and norepinephrine were not altered by UW solution. In summary, the impaired endothelium-dependent relaxation by UW solution and prominent endothelium-dependent contraction to hypoxia of human hepatic artery would favor vasospasm and thrombus formation after liver transplantation.

Adenosine↗
PubMed1996

Video-assisted mitral valve operations.

BACKGROUND: Video-assisted endoscopy has been applied frequently in the management of a variety of surgical diseases. However, it has rarely been applied in mitral valve surgery. METHODS: We report 2 patients who received emergency operations for thrombosis of a mitral prosthesis (patient 1, a 68-year-old man) and acute mitral regurgitation due to rupture of anterior chordae (patient 2, a 75-year-old woman). They both had severe congestive heart failure. Cardiogenic shock was noted in patient 2. The mitral valve was approached through a right anterior minithoracotomy with the aid of an endoscope by means of projected images on the video monitor under femorofemoral cardiopulmonary bypass. The aorta was not cross-clamped, and the myocardium was protected by continuous coronary perfusion with hypothermic fibrillatory arrest. The left atrium was entered posterior to the interatrial groove. Thrombectomy and mitral valve repair were performed successfully. RESULTS: The duration of extracorporeal circulation was 204 and 147 minutes, respectively. Both patients recovered from the operation rapidly with uneventful postoperative courses. CONCLUSIONS: Our preliminary results suggest that video-assisted endoscopic cardiac surgery is technically feasible and could be performed in the milieu of open heart surgery.

Aged↗
PubMed1996

Video-assisted cardiac surgery in closure of atrial septal defect.

BACKGROUND: Video-assisted endoscopy has been applied in the management of a variety of intrathoracic vascular lesions. Here we report its use in the correction of intracardiac congenital defects. METHODS: Eight patients (3 male and 5 female) underwent operation for closure of an atrial septal defect. The patients ranged in age from 2.0 to 60.9 years (mean, 19.2 +/- 19.0 years). The patients weighed 11 to 66 kg (mean, 41.3 +/- 23.5 kg). The ratio of pulmonary blood flow to systemic blood flow ranged from 2.0 to 6.0 (mean, 3.4 +/- 1.3). The mean pulmonary artery pressure was 19.7 +/- 4.0 mm Hg (range, 13 to 24 mm Hg). The operations were performed through a right anterior minithoracotomy and guided by video-assisted endoscopic techniques under femorofemoral or femoral-right atrial extracorporeal circulation. The aorta was not cross-clamped, and the myocardium was protected by continuous coronary perfusion with hypothermic fibrillatory arrest (rectal temperature, 22.0 degrees +/- 2.0 degrees C). Transesophageal echocardiographic monitoring was maintained during the operations. The right atrium was entered after pericardiotomy. Primary closure of the defect was performed successfully in all patients. Conventional nondisposable instruments were used for dissection, grasping, suturing, and hemostasis. RESULTS: The durations of extracorporeal circulation and operation ranged from 47 to 126 minutes (mean, 80 +/- 31 minutes) and from 2.2 to 4.5 hours (mean, 3.1 +/- 0.8), respectively. All patients recovered from the operation rapidly with an uneventful postoperative course. CONCLUSIONS: Our experience demonstrates that video-assisted cardiac surgery is technically feasible and can be used with excellent results for the repair of congenital heart defects in general.

Adolescent↗
PubMed1996

Augmented endothelium-dependent constriction to hypoxia early and late following reperfusion of the canine coronary artery.

1. Canine coronary arteries with intact endothelium respond to hypoxaemia or serotonin infusion with dilatation, but when the endothelium is injured or dysfunctional, these stimuli can cause constriction. The present studies investigated whether or not regional ischaemia and reperfusion alter endothelium-dependent responsiveness of canine coronary arteries in vivo and in vitro. 2. In organ chamber experiments, isolated control and reperfused coronary artery rings were contracted with prostaglandin F2 alpha and exposed to hypoxia (PO2 less than 5 mmHg). 3. Hypoxia augmented the response of reperfused arteries more than that of controls. The hypoxic augmentation was blocked by NG-monomethyl-L-arginine, an inhibitor of nitric oxide synthesis from L-arginine. 4. These findings demonstrate that early following coronary reperfusion the hypoxic augmentation, which is mediated by a nitric oxide-dependent pathway in the endothelium, is facilitated. 5. In vivo studies revealed hyperconstriction of reperfused arteries in response to hypoxaemia (PO2 = 30-40 mmHg) and administration of either serotonin or ergonovine. 6. Twelve weeks following reperfusion injury, coronary arteries still exhibited augmented endothelium-dependent hypoxic augmentations in vitro, which were inhibited by NG-monomethyl-L-arginine. 7. Furthermore, resting coronary segments with endothelium displayed hypoxia-induced contractions that could not be inhibited by indomethacin, the lipoxygenase inhibitor AA861, superoxide dismutase plus catalase, deferoxamine, ouabain, or NG-monomethyl-L-arginine. 8. These endothelium-dependent hypoxic response may play a role in the pathogenesis of hyperconstriction (vasospasm) following coronary reperfusion.

Analysis of Variance↗
PubMed1996

Video-assisted cardiac surgery. Preliminary experience in reoperative mitral valve surgery.

OBJECTIVES: Video-assisted endoscopic techniques had been applied in the surgical correction of patent ductus arteriosus, vascular ring, or coronary artery disease. However, it has been used only recently in the correction of reoperative mitral valve lesions. DESIGN: Video-assisted cardiac operations were performed on four patients who had received surgical interventions on their mitral valves and needed emergent reoperation. PATIENTS: Four patients (3 men and 1 woman) received emergency surgery from September to December 1995 for thrombosis of mechanical mitral prosthesis (2 patients) and severe mitral regurgitation with previously failed mitral valve repair (2 patients). Six previous operations had been performed on these mitral valves. Patient ages ranged from 26.7 to 68.1 years (mean, 47.3 years). Preoperatively, acute pulmonary edema occurred in two patients, cerebral emboli occurred in one patient, and sepsis was found in one patient. Mechanical ventilatory support was used in two patients before operation. INTERVENTION: The operations were performed through right anterior minithoracotomy, guided by video-assisted endoscopic techniques with femoro-femoral extracorporeal circulation. The operative procedures were thrombectomy of mitral prosthesis in two patients, mitral valve repair in one patient, and mitral valve replacement in one patient. RESULTS: The duration of extracorporeal circulation was 166 to 320 min (222 +/- 67 min) and the operation time was 4.6 to 6.8 h (6.1 +/- 1.0 h). All patients recovered from the operations rapidly with uneventful postoperative courses except 1 patient who had sepsis preoperatively and died 2 months later. CONCLUSION: Our experience demonstrates that video-assisted cardiac surgery is technically feasible and could be performed in reoperation of the mitral valve.

Adult↗
PubMed1996

Modified Blalock-Taussig shunt: statistical analysis of potential factors influencing shunt outcome.

From January 1986 to December 1991, 100 modified Blalock-Taussig Shunts (MBTS) using PTFE (polytetrafluoroethylene) grafts were performed on 86 patients with complex cyanotic congenital cardiac malformations at this hospital. The ages of patients ranged from 15 days to 22 years. Thirty-seven were operated upon in infancy and one in the neonatal period. Varying sizes of grafts were used: 3 mm in 3 cases, 4 mm in 18, 5 mm in 44, 6 mm in 34 and 8 mm in one. The mean follow-up period was 13.5 months (ranged from one to 50 months). There were one hospital mortality and one morbidity. One year shunt patency rate was 90%. Univariate analysis showed the age of the patient operated upon and graft size were risk factors for shunt patency. With an encouraging 90% early shunt patency rate, we can now adopt MBTS as an alternative without hesitancy. Yet, the surgical technique and perioperative care of those cyanotic neonates receiving this palliation still remain a challenge.

Adult↗
PubMed1996

Experimental patch bronchoplasty with ringed vascular graft.

The best surgical technique in bronchial reconstruction is resection and end to end anastomosis, but in some cases either pathology length, reduction in tissue elasticity, or such circumstances, patch bronchoplasty may be necessary to reestablish air-passage continuity. The purpose of this experiment would thus try to investigate the possibility of using ringed polytetrafluoroethylene (PTFE) graft to repair the diseased bronchus. A 2 x 1 cm patch segment of bronchus resected in 10 dogs were followed up with monthly bronchoscopy and endoscopic photography. Euthanasia was performed at 3, 6 and 9 months or when signs of respiratory distress developed. At postmortem examination, the anastomoses were examined grossly and with light microscopy. In 5 of the 10 dogs that underwent bronchial repair with PTFE, granulation tissue developed at the anastomoses resulting in airway obstruction after 6 to 9 months. No epithelial growth occurred over the graft between the suture lines. We conclude that the granulation tissue formation at the anastomosis and the lack of respiratory epithelial ingrowth across the graft makes PTFE unsuitable for patch repair of the bronchial defect.

Animals↗
PubMed1996

Primary chondrosarcoma of the heart: a case report.

Chondrosarcoma involving the heart has been previously reported but is extremely rare. Most chondrosarcoma described in the literature are secondary, and the primary site can be identified. We present an unusual case of primary cardiac chondrosarcoma which originated in the left atrium. Severe pulmonary edema was the first presentation. The sarcoma subsequently metastasized to the mandible and finally recurred in the right heart causing severe pulmonary emboli and myocardial failure.

Adult↗
PubMed1995

Endothelium-dependent contraction of canine coronary artery is enhanced by crystalloid cardioplegic solution.

Experiments were designed to determine whether hyperkalemic crystalloid cardioplegic solution enhances endothelium-dependent contraction of coronary arteries. Segments of canine coronary arteries (n = 8 in each group) were preserved in cold (4 degrees C) crystalloid cardioplegic solution (group 1) and physiologic solution (group 2) for 60 minutes. Segments of preserved and control (group 3) coronary arteries with or without endothelium were suspended in organ chambers to measure isometric force. Perfusate hypoxia (oxygen tension 35 +/- 5 mm Hg) caused endothelium-dependent contraction in the arteries of all three groups. However, vascular segments with endothelium of group 1 exhibited hypoxic contraction (68.5% +/- 15.3% of the initial tension contracted by prostaglandin F2 alpha 2 x 10(-6) mol/L, p < 0.05) that was significantly greater than contraction of the group 2 and group 3 segments with endothelium (26.6% +/- 5.6% and 20.6 +/- 4.4%). The hypoxic contraction in arteries of group 1 could be attenuated by NG-monomethyl-L-arginine, the blocker of endothelial cell synthesis of the nitric oxide from L-arginine. The action of NG-monomethyl-L-arginine could be reversed by L-arginine but not D-arginine. Thus after preservation with cardioplegic solution, augmented endothelium-dependent contraction, occurs by L-arginine-dependent pathway, would favor coronary vasospasm after cardiac operation.

Animals↗