Biomedical subjects

Ming-Che Lee

Publications and source records attributed to Ming-Che Lee.

5 recordsLinked to original sources

PubMed2006

A severe vicious cycle in uncontrolled subarachnoid hemorrhage: the effects on cerebral blood flow and hemodynamic responses upon intracranial hypertension.

In subarachnoid hemorrhage (SAH), Cushing postulated that the increase in systemic arterial pressure (SAP) in response to elevation of intracranial pressure (ICP) was beneficial to cerebral perfusion. However, in uncontrolled SAH, the increased SAP may cause more bleeding into the subarachnoid space and further increase the ICP. We created an animal model to simulate SAH by connecting a femoral arterial catheter to the subarachnoid space. The global cerebral blood flow (CBF) was measured with a venous outflow method. The purposes were to observe the CBF change under the simulated SAH, and to evaluate the effects of an adrenergic blocker and a vasodilator. In addition, spectral analysis of the aortic pressure and flow was employed for the analysis of hemodynamic changes at various ICP levels. When the femoral arterial blood was allowed to flow into the subarachnoid space, the ICP was elevated. The Cushing response to increased ICP caused an increase in SAP. A vicious cycle was generated between ICP and SAP. The CBF under the vicious cycle was greatly depressed. The dog developed pulmonary edema (PE) within 5 mins. An alpha-adrenergic blocker (phentolamine) and a vasodilator (nitroprusside) were beneficial to the reduction of SAP and ICP, improvement of CBF, and prevention of PE. Hemodynamic analysis revealed that graded increases in ICP caused increases in SAP, total peripheral resistance, arterial impedance, and pulse reflection with decreases in stroke volume, cardiac output and arterial compliance. The hemodynamic changes may contribute to acute left ventricular failure that leads to pressure and volume loading in the lung circulation, and finally acute PE.

Adrenergic alpha-Antagonists↗

PubMed2006

Primary appendiceal malignancy: a clinicopathologic study.

Primary appendiceal cancer is a rare neoplasm. We analyzed the clinicopathologic characteristics and clinical outcomes of patients with primary appendiceal cancer treated at Buddhist Tzu Chi General Hospital in Eastern Taiwan. We reviewed the medical records of patients who had appendectomy at our hospital over a 10-year period and studied those who had histologically proven malignant appendiceal neoplasms. We treated eight such patients: seven males and one female. Their median age was 66 years (range, 59-78 years). There were three mucinous adenocarcinomas, two colonic type adenocarcinomas, and three adenocarcinoids. No patient was diagnosed correctly before surgery, and five (62.5%) had a preoperative diagnosis of acute appendicitis. Operative procedures included right hemicolectomy or partial colectomy in four, debulking and right hemicolectomy in three, and appendectomy only in one. With a mean follow-up of 64 months (range, 3-132), patients with adenocarcinoid lesions had better prognosis than those with adenocarcinomas. The important prognostic factors of primary appendiceal cancer included histologic subtypes and the extent of dissemination. In our series, palliative resection for disseminated lesions with or without additional chemotherapy resulted in long-term survival.

Adenocarcinoma↗

PubMed2005

Left paraduodenal hernia presenting as recurrent small bowel obstruction.

Internal herniation of the small bowel is a relatively rare cause of intestinal obstruction. Left paraduodenal hernia resulting from abnormal rotation of the midgut during embryonic development is the most common form of congenital internal hernia. We report our experience in the diagnosis and management of a young male with left paraduodenal hernia presenting as recurrent intestinal obstruction. Correct preoperative diagnosis of left paraduodenal hernia had been difficult due to non-specific clinical presentations, but the advent of modern imaging technology makes early and correct diagnosis possible. Due to the risk of obstruction and strangulation, surgical treatment is indicated; however, timely intervention increases the likelihood of a favorable outcome.

Adult↗

PubMed2005

Natriuretic peptides cause relaxation of human and guinea-pig gallbladder muscle through interaction with natriuretic peptide receptor-B.

Atrial natriuretic peptide (ANP) binding sites have been demonstrated in the guinea-pig gallbladder muscle with unclear function. To investigate effects of natriuretic peptides in the gallbladder, we measured relaxation of isolated human and guinea-pig gallbladder strips caused by natriuretic peptides, including C-type natriuretic peptide (CNP), brain natriuretic peptide (BNP) and ANP, as well as des[Gln18, Ser19, Gly20, Leu21, Gly22]ANP(4-23) amide (cANP(4-23)), a selective natriuretic peptide receptor-C (NPR-C) agonist. Results in the human gallbladder were similar to those in the guinea-pig gallbladder. CNP, BNP, ANP and cANP(4-23) alone did not cause contraction or relaxation in resting gallbladder strips. However, in carbachol or endothelin-1-contracted strips, CNP caused moderate, sustained and concentration-dependent relaxation. The relaxation was not affected by tetrodotoxin or atropine in endothelin-1-contracted gallbladder strips and not by tetrodotoxin in carbachol-contracted strips. These indicate a direct effect of CNP on the gallbladder muscle. The relative potencies for natriuretic peptides to cause relaxation were CNP>>BNP> or = ANP. cANP(4-23) did not cause relaxation. These indicate the existence of the natriuretic peptide receptor-B (NPR-B) mediating the relaxation. Taken together, these results demonstrate that natriuretic peptides cause relaxation of human and guinea-pig gallbladder muscle through interaction with the natriuretic peptide receptor-B.

Animals↗

PubMed2002

Influence of cold ischemia time and graft transport distance on postoperative outcome in human liver transplantation.

PURPOSE: The association between hepatic allograft cold ischemia time (CIT) and graft transport distance (GTD) in human liver transplantation was examined by investigating whether extended graft transportation prolongs the CIT and adversely affects graft survival. METHODS: We retrospectively analyzed 186 consecutive orthotopic liver transplants (OLTs) done between May 1997 and July 1998. The number of miles from the donor hospital to the University of Pittsburgh Medical Center in a straight line was measured in each case, and defined as the GTD. The OLTs were divided into two groups according to whether the GTD was </=200 miles or >200 miles. The latter group was then subdivided into groups of GTD 200-400 miles, GTD 400-600 miles, and GTD >600 miles. The CIT and graft outcome within 90 days after OLT were assessed. RESULTS: Extended GTD prolonged the CIT ( P < 0.001). The rate of hepatic allograft loss in the long GTD group was significantly higher than that in the short GTD group ( P = 0.018). When the OLTs were subdivided according to GTD, the CIT increased and graft survival decreased as the GTD extended. Hepatic allograft transportation for a long distance prolonged the CIT and decreased the graft survival rate. CONCLUSION: Since prolonged CIT is a major risk factor, avoiding long-distance graft transportation is recommended when the donor risk factors are high.

Adolescent↗