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Biomedical subjects

M F Chen

Publications and source records attributed to M F Chen.

At least 127 records · Page 7Linked to original sources
PubMed1998

Ultrasonic tissue characterization in predicting residual ischemia and myocardial viability for patients with acute myocardial infarction.

The identification of viable myocardium and residual ischemia in patients with acute myocardial infarction has important prognostic implications. The ultrasonic tissue characterization with integrated backscatter and dobutamine-atropine stress echocardiography were performed 8.3+/-3 days after AMI in 30 patients. After coronary angioplasty for the residual stenosis of infarct-related artery, both modalities were repeated. The parameter obtained from ultrasonic tissue characterization, phase-weighted variation, could differentiate the myocardium with residual coronary stenosis or nonviable myocardium from the viable myocardium without residual coronary stenosis (p < 0.001). Using the cutoff value of 5.8 dB, the sensitivity, specificity and accuracy for detecting viable myocardium without residual coronary stenosis were 75%, 100% and 90.2%, respectively. The phase-weighted variation of the viable infarction zone restored after the coronary stenosis was relieved. In contrast, the nonviable myocardium had a small phase-weighted variation that was irrelevant to the patency of the infarct-related artery. The ultrasonic tissue characterization may be used in identifying patients with acute myocardial infarction whose infarction zones are viable without residual ischemia.

Angioplasty↗
PubMed1998

Plasma thiamine deficiency associated with Alzheimer's disease but not Parkinson's disease.

In this study we compared plasma and erythrocyte thiamine levels in a group of patients with idiopathic Parkinson's Disease (iPD) to a group of patients with probable Alzheimer's Disease (pAD). pAD patients had significantly lower plasma thiamine levels (raw and z-score) than iPD patients. A significantly higher number of pAD patients had plasma thiamine deficiencies than iPD patients. The demographics of our patient groups were similar to those reported by other investigators, making age, sex and nutritional status unlikely explanations for our findings. These results suggest that plasma thiamine deficiency is associated with pAD but not with iPD.

Adult↗
PubMed1998

Hepatocellular carcinoma complicated with coexisting hepatolithiasis: pitfalls in diagnosis and management.

Nineteen patients with hepatocellular carcinoma associated with hepatolithiasis were retrospectively analyzed. Eleven of the 19 patients presented with hepatolithiasis-related biliary infection. Diagnosis was erroneously assumed to be hepatolithiasis alone, liver abscess, or cholangiocarcinoma in five of 11 patients before surgery was attempted. Middle-age, male sex, liver cirrhosis, hepatitis B or C infection, abnormal alpha-fetoprotein, and negative carcinoembryonic antigen raised the suspicion of associated hepatocellular carcinoma rather than cholangiocarcinoma in patients with hepatolithiasis. Antibiotics and nonoperative methods to resolve biliary infection first, followed by hepatectomy, in selected cases, to eradicate hepatocellular carcinoma and hepatolithiasis simultaneously provides the best chance for long-term survival. Otherwise, patients often died of hepatolithiasis-related biliary sepsis rather than hepatocellular carcinoma per se in the long run.

Adult↗
PubMed1998

Determinative role of peroxidized low-density lipoprotein in myocardial thromboxane synthesis during pacing-induced ischaemia in humans.

1. Myocardial thromboxane A2 production increases in patients with pacing-induced ischaemia and correlates with a decrease in myocardial lactate extraction. The release of myocardial thromboxane A2 before any lactate production was observed in patients with unstable angina. This study was proposed to clarify whether the early thromboxane A2 release contributed to the ongoing myocardial ischaemia and to determine which metabolites can be attributed to the thromboxane A2 release. Thirty-five patients with chest pain and positive treadmill exercise test underwent atrial pacing to the predicted maximal heart rate. The pacing was maintained at this peak rate for 10 min, then ceased. Blood samples of the ascending aorta and coronary sinus were drawn simultaneously at rest, at 2 and 10 min of peak-pacing, and 5 and 10 min after termination of the pacing; samples were used for analyses of lipid profiles, prostacyclin, thromboxane A2, lactate and lipid peroxides on plasma and low-density lipoprotein particles. 2. Twenty out of 35 patients who displayed pacing-induced ischaemia were documented by electrocardiographic evidence of ST depression > 2 mm developing after 2 min of peak-pacing [ischaemic group, ST delta(+)]. They had (i) negative fractional lactate extraction; (ii) pacing-induced decreases of plasma thromboxane A2 levels in the coronary sinus blood (564 +/- 57 versus 479 +/- 47 ng/l, P < 0.05) at 2 min of peak-pacing; the data increased at 10 min of peak-pacing (564 +/- 57 versus 620 +/- 60 ng/l, P < 0.05), then returned to baseline levels at 5 and 10 min post-pacing; (iii) significantly increased lipid peroxides on low-density lipoprotein of the coronary sinus blood at 2 and 10 min of peak-pacing (each P < 0.001), as well as at 5 min post-pacing (P < 0.05); (iv) significant correlation between thromboxane A2 levels and lipid peroxides on low-density lipoprotein of the coronary sinus blood samples. 3. In ST delta(+) patients, myocardial thromboxane synthesis changed before lactate production and correlated with the increase of lipid peroxides on low-density lipoprotein of the coronary venous blood. This implies that lipid peroxides on low-density lipoprotein participate in thromboxane production and play a determinative role in pacing-induced ischaemia.

Analysis of Variance↗
PubMed1998

Surgical results in patients with dual hepatitis B- and C-related hepatocellular carcinoma compared with hepatitis B- or C-related hepatocellular carcinoma.

BACKGROUND: The purpose of our study was to report on the surgical outcomes of patients with hepatocellular carcinoma (HCC) with dual hepatitis B virus (HBV) and hepatitis C virus (HCV) infections and to assess the differences in the surgical results between those patients and the patients with hepatitis B- or hepatitis C-related HCC. METHODS: The operative outcomes of 13 patients with hepatitis B surface antigen (HBsAg)-positive and hepatitis C antibody (HCV Ab)-positive (the BC-HCC group) results, 57 patients with HBsAg-positive and HCV Ab-negative (the B-HCC group) results, and 34 patients with HBsAg-negative and HCV Ab-positive (the C-HCC group) results, who had undergone hepatic resection from 1991 to 1995, were compared. RESULTS: The operative mortality rate within 1 month after operation for patients with BC-HCC was 7.7%. No statistically significant difference was found compared with the patients with B-HCC and C-HCC (5.3% and 5.9%, respectively). The postoperative course of patients with BC-HCC was complicated by liver failure, postoperative ascites, and wound infection in one patient each. Also, no statistically significant difference was found among the groups (23.1%, 22.8%, and 20.5% for patients with BC-HCC, B-HCC, and C-HCC, respectively). The overall 1-, 3-, and 5-year survival rates of patients with BC-HCC in this series were 75%, 50%, and 40%, respectively. The postoperative recurrence rate was 66.7%. No statistically significant differences were found between the various groups of the virus-related HCC on the overall survival rate and disease-free survival rate. CONCLUSIONS: Hepatic resection for HCC in patients with dual HBV and HCV infections was associated with slightly higher operative morbidity and mortality rates, but there were no statistical differences compared with hepatitis B- or C-related HCC regarding the survival and recurrence rates.

Carcinoma, Hepatocellular↗
PubMed1998

Hepatocellular carcinoma presenting as pyogenic liver abscess: characteristics, diagnosis, and management.

We performed a 17-year retrospective analysis of 10 cases of hepatocellular carcinoma presenting as pyogenic liver abscess. Spontaneous tumor necrosis and biliary obstruction caused by tumor thrombi, superimposed with bacterial infection, were the two major pathogeneses. Exact diagnosis of the underlying hepatocellular carcinoma was made for five of the 10 patients before management was attempted. Main clinical manifestations included fever, chills, right-upper-quadrant pain, malaise, anorexia, jaundice, and hepatomegaly. Characteristics such as middle age and male sex, seropositivity for hepatitis B and/or hepatitis C, chronic liver disease, unexplained anemia, marked weight loss, and a severely inversed albumin/globulin ratio raise suspicions about the underlying hepatocellular carcinoma. Management strategies included percutaneous drainage (n = 3), surgical drainage (n = 4), and hepatectomy (n = 3) in addition to administration of parenteral antibiotics in all cases. The prognosis was dismal, with a mean survival of 3.5 months (range, 8 days to 6 months).

Adult↗
PubMed1998

Clinical studies of mucin-producing cholangiocellular carcinoma: a study of 22 histopathology-proven cases.

OBJECTIVE: We present the clinical features and outcomes of 22 surgically treated and histopathology-proven cases of mucin-producing cholangiocellular carcinoma (MPCCC). BACKGROUND: Cholangiocellular carcinoma (CCC) is an uncommon malignancy. Unlike hepatocellular carcinoma, it is difficult to set up a high-risk group, and a specific tumor marker has yet to be found. Chronic liver disease is usually not found to be associated with CCC. Information about patients with MPCCC is limited, and the frequency of MPCCC in all patients with CCC has not been reported. METHODS: The clinical features of 22 surgically treated and histopathology-proven cases of MPCCC were reviewed, including morbidity, mortality, and follow-up results. Factors that may influence the outcomes were also analyzed. Clinical features and outcomes of 148 patients with non-mucin-producing cholangiocellular carcinoma (non-MPCCC) were also summarized for comparison. RESULTS: Of 170 cases of CCC, 22 (12.9%) were MPCCC. Imaging studies were important in the differential diagnosis of CCC. Operative findings (e.g., gross appearance of the liver, mucobilia found by common bile duct exploration, choledochoscopic findings, and frozen section) were useful in the diagnosis of MPCCC. Surgical procedures included common bile duct exploration, or hepaticostomy, and intraoperative choledochoscopy in all 22 patients. Hepatic resection was done in 14 of the 22 cases (63.6%). No early surgical mortality was noted. Wound infections (two patients), bile leak (one patient), and intraabdominal abscess (one patient) were the postoperative complications. The 1-, 2-, 3-, 4-, and 5-year survival rates were 86.5%, 68.5%, 59.0%, 38.5%, and 31.0%, respectively. A significant difference in survival pattern was found between the MPCCC and non-MPCCC patient groups. Patients with hepatic resection had a significantly better prognosis than those without resection. Although patients with hepatolithiasis had a better survival pattern than those without hepatolithiasis, the difference was not statistically significant. CONCLUSIONS: We present the clinical features and outcomes of 22 surgically treated and histopathology-proven cases of MPCCC. Patients with hepatic resection were found to have better survival rates.

Adenocarcinoma, Mucinous↗
PubMed1998

Selective application of laparoscopy and fibrin glue in the failure of nonoperative management of blunt hepatic trauma.

BACKGROUND: Most blunt hepatic trauma patients can be managed nonoperatively. The current failure rate in adult blunt hepatic trauma is reportedly 0 to 19%. We wished to evaluate the applicability of laparoscopy and fibrin glue as a minimally invasive alternative to laparotomy in these unsuccessfully nonoperative cases. METHODS: All adult patients with blunt hepatic trauma managed nonoperatively at Linkou, Chang Gung Memorial Hospital Medical Center, Taipei, Taiwan, over a 2-year period from July 1, 1994, to June 30, 1996, were eligible for the study. A laparoscopic examination was performed on those who failed conservative care before undertaking an exploratory laparotomy. Fibrin glue was sprayed over the wound surface if ongoing hemorrhage was evident from any liver laceration. The clinical data, operative and laparoscopic findings, operative methods, and outcomes of these patients were studied. RESULTS: Of the 61 patients, 55 patients were successfully treated without operation. Of the six failures (10%) all were liver related. After the introduction of laparoscopy, the nontherapeutic laparotomy rate would have decreased from 100% (6 of 6) to 50% (3 of 6), and with the adjunctive use of fibrin glue, the laparotomy rate went down to 0% (0 of 6). There were no deaths among the six patients receiving laparoscopy and fibrin glues; and only one developed a liver abscess, for a morbidity rate of 17% (1 of 6). CONCLUSIONS: The selective use of laparoscopy and fibrin glue can effectively reduce the nontherapeutic laparotomy rate among blunt hepatic trauma patients who fail nonoperative management.

Adolescent↗
PubMed1998

Leukocyte-endothelial adherence correlates with pancreatic nitric oxide production in early cerulein-induced pancreatitis in rats.

The role of nitric oxide (NO) in microcirculation during the development of acute pancreatitis was not clear. An in vivo microscopic technique was used for evaluating leukocyte-endothelial adherence in the pancreatic microcirculation after induction (cerulein) of acute pancreatitis. Microdialysis was performed to detect pancreatic nitrate concentration (NO level) by high-performance liquid chromatography. Cerulein caused significantly reduced flow velocity in 1 h (31 %) and increased the number of sticking leukocytes in 2 h; both persisted for at least 3 h. Pancreatic NO level was found to be significantly elevated (2.5-fold) in 1 h and also persisted for 3 h. Both microcirculatory changes and NO elevation were significantly alleviated in cerulein-induced animals pretreated with NO synthase inhibitor (NG-nitro-L-arginine), indicating that elevation of NO could precede and account for a major portion of the observed microcirculatory changes. Furthermore, there was a strong positive correlation between numbers of adherent leukocytes and pancreatic NO level, suggesting that during the development of acute pancreatitis, NO could play an adverse role in microcirculation.

Animals↗
PubMed1998

Cholangiocarcinoma presenting as pyogenic liver abscess: is its outcome influenced by concomitant hepatolithiasis?

OBJECTIVE: The etiology of pyogenic liver abscess is changing. Malignant biliary obstruction has emerged as one of the most important causes. We explored the clinical course of pyogenic liver abscess caused by cholangiocarcinoma. METHODS: The medical records of 19 patients with cholangiocarcinoma presenting as pyogenic liver abscess were reviewed. Of them, 57.8% (11 of 19) had concomitant hepatolithiasis. Escherichia coli and Klebsiella pneumoniae were the most common pathogens isolated from aspirates of the abscesses. Eight patients received percutaneous drainage, whereas 11 patients initially underwent surgical drainage because of the presence of ascites or coagulopathy or lack of awareness of the underlying cholangiocarcinoma. RESULTS: Overall, the hospital mortality rate was 36.8% (seven of 19). Patients with hepatolithiasis had a hospital mortality rate of 54.5% (six of 11), compared with 12.5% (one of eight) in those without (p < 0.01). Notably, 84.2% (16 of 19) of the patients died within 6 months after the diagnosis was made. CONCLUSIONS: Cholangiocarcinoma presenting as liver abscess has a dismal prognosis. Concomitant hepatolithiasis worsened the infectious process and adversely affected the survival.

Adult↗
PubMed1998

Hyperbaric oxygen pretreatment attenuates hepatic reperfusion injury.

Microcirculatory derangement, energy depletion and lipid peroxidation have been related to development of ischemia-reperfusion injury in the liver. This study investigates the effects of hyperbaric oxygen (HBO) on hepatic ischemia-reperfusion injury. Adult, male Sprague-Dawley rats were used. Three groups were evaluated: 1) sham-operated control (laparotomy only, no ischemia, no HBO), n=8; 2) ischemia control (1-h ischemia, 2-h reperfusion, no HBO), n=8; and 3) HBO pretreatment (100%, oxygen, 2.5 atm absolute, 90 min) plus ischemia (1-h ischemia, 2-h reperfusion), n=8. An in vivo microscope was used to investigate hepatic microcirculation. Tissue malondialdehyde (MDA) and adenosine triphosphate (ATP) were determined. In comparison with the ischemia control group, HBO significantly improved harmful insults following ischemia-reperfusion. HBO lessened adherent leukocyte count (6.00+/-1.31 cells/200 microm vs 11.38+/-2.88 cells/200 microm), and improved flow velocity (1.72+/-0.26 mm/s vs 0.83+/-0.19 mm/s) in post-sinusoidal venules. HBO also reduced MDA (1.04+/-0.24 nmol/mg protein vs 2.24+/-0.49 micromol/g protein), and increased ATP (2.03+/-0.17 micromol/g wet wt vs 0.73+/-0.11 micromol/g wet wt) levels. This study demonstrates that HBO before ischemia may ameliorate the ischemia-reperfusion injury of the liver in the rat model.

Adenosine Triphosphate↗
PubMed1998

Tracheal botryomycosis in a patient with tracheopathia osteochondroplastica.

Tracheal botryomycosis has never been reported in the literature. A 68 year old man presented with progressive dyspnoea and an exophytic mass below the vocal cords was found by bronchoscopy. Pathological study of the mass showed tracheal botryomycosis probably associated with Peptostreptococcus spp infection. The patient was given intravenous penicillin for six weeks. Tracheal obstruction necessitated tracheal resection and the surgical specimen revealed typical findings of tracheopathia osteochondroplastica without residual lesions of botryomycosis.

Aged↗
PubMed1998

The correlation between skin electrical conductance and the score of qi vacuity.

In traditional Chinese medicine, the syndrome of qi vacuity means that the patient's body has a low level of energy to react to stress. Recently, we used a score, the QV score, by scaling the severity of symptoms and signs of qi vacuity in patients with tiredness. The aim of this study was to investigate the relationship between QV score and skin electrical conductance in patients with tiredness. One hundred and forty-three healthy controls and 103 patients with tiredness were involved. Each subject received a weak electrical stimulation with constant voltage (1.75 volt), and conductance was measured between two different limbs. The mean value of skin conductance among four limbs was calculated and expressed by a special unit, namely Chin. The correlation between the skin conductance and QV score was analyzed by a linear regression analysis. The results showed that skin electrical conductance of healthy controls was negatively correlated with age (r-coefficient = -0.51, P = 0.000). The skin conductance of patients with tiredness was significantly lower than that of healthy controls with matching age (P = 0.000 by Student's t-test). Moreover, there was a positive correlation between the decrease of skin conductance and the QV score in patients with tiredness (r-coefficient = +0.68, P = 0.000). These results suggest that a decrease in skin electrical conductance may be closely related to the severity of qi vacuity. The skin conductance test is a simple, reliable, and quantitative method for detection of syndrome of qi vacuity.

Adult↗
PubMed1998

Assessment of the coronary artery disease and systolic dysfunction in hypertensive patients with the dobutamine-atropine stress echocardiography: effect of the left ventricular hypertrophy.

This study was performed to evaluate whether left ventricular hypertrophy (LVH) can influence the diagnostic accuracy of coronary artery disease (CAD) using the dobutamine stress echocardiography (DSE) in hypertensive patients. In addition to the detection of CAD, the relationship between systolic dysfunction and the quantitation wall motion scoring system of DSE was studied also. DSE was performed in 101 patients. There were 45 (45%) patients with a history of acute myocardial infarction. Twenty-eight patients (28%) had electrocardiographic LVH and 59 patients (58%) had echocardiographic LVH. A total of 74 patients (73%) had angiographically documented CAD defined as > or = 50% diameter stenosis. For the 56 patients without history of myocardial infarction, the diagnostic sensitivity, specificity, and accuracy in detecting CAD were not influenced by LVH defined by either electrocardiography or echocardiography. For the total patients, the diagnostic sensitivity, specificity, and accuracy in detecting multivessel disease were also not influenced by LVH defined by either method. The resting global wall motion score was correlated well with the left ventricular ejection fraction in patients with and without LVH (r = -0.70, p < 0.001 vs. r = -0.70, p < 0.001). When using the resting wall motion score of 24 as a cutoff value, the diagnostic sensitivity, specificity, and accuracy of systolic dysfunction (defined by left ventricular ejection fraction <40%) were 79, 86 and 85%, respectively. In conclusion, the diagnostic accuracy of CAD using the DSE was not affected by LVH in hypertensive patients. In addition to detection of coronary artery disease, the resting wall motion score of DSE was able to detect systolic dysfunction in patients with and without LVH.

Aged↗
PubMed1998

Increase in resting levels of superoxide anion in the whole blood of uremic patients on chronic hemodialysis.

Recently, we developed a new method to measure the resting level of superoxide anion in whole blood using an ultrasensitive chemiluminescence analyzer and lucigenin amplification. The advantage of this method is that the assay system can be performed in the absence of leukocyte isolation and stimulant administration. In this study, we applied this method to measure the blood resting levels of superoxide anion in 104 uremic patients on chronic hemodialysis (CHD) and 98 sex- and age-matched healthy controls to clarify the influence of HD on blood levels of superoxide anion. Simultaneously, the plasma levels of copper, zinc superoxide dismutase (Cu,Zn-SOD), glutathion peroxidase (GPX), myeloperoxidase (MPO) and lactoferrin (Lacto-F) were measured. The results showed that the basal blood levels of superoxide anion, Cu,Zn-SOD, and MPO in CHD patients were significantly greater than those of healthy controls. However, there was no difference in the basal plasma levels of Lacto-F and GPX between CHD patients and healthy controls. One session of HD further increased the blood levels of superoxide anion, MPO, Lacto-F and Cu,Zn-SOD but not GPX. These results suggest that the blood levels of superoxide anion are higher in CHD patients and further increase after one session of HD. This mechanism should be studied further.

Acridines↗
PubMed1998

Prognostic factors in node-negative breast cancer patients: the experience in Taiwan.

BACKGROUND: Adjuvant chemotherapy has improved the length of disease-free survival and overall survival in node-negative breast cancer patients. It has been a common practice to select only the patients with higher rates of recurrence for adjuvant therapy. Therefore, it is essential to define the risk factors in node-negative breast cancer patients. MATERIALS AND METHODS: Two hundred fifty-five patients with axillary node-negative breast cancers without adjuvant chemotherapy or hormonal therapy at Chang Gung Memorial Hospital between 1981 and 1986 were included in this study. Tissue blocks for DNA flow cytometry study was available in the tumors of 145 patients. RESULTS: The median follow-up period was 121 months and the percentages of patients with 10 years of disease-free survival (DFS) and overall survival (OS) were 75.1% and 82.2%, respectively. The significant poor prognostic factors for 10 years of OS were a tumor size larger than 3 cm, negative estrogen and progesterone receptor status, and having a non-diploid tumor (p value = 0.0176, 0.048 and 0.016, respectively). The patients with frozen section, high mitotic rate, and Scarff-Blood-Richardson (SBR) grade II and III tumors had a worse prognosis than the others, but this trend did not reach statistical significance. The patients with positive estrogen receptor status had a 10-year disease-free rate (DFR) of 94%, and these with tumors less than 2 cm plus SBR grade I had a 10-year DFR of 92%. CONCLUSION: The node-negative breast cancer patients with a low risk of recurrence were those who had estrogen receptor positive, tumor less than 2 cm with SBR grade I, and intraductal carcinomas. Adjuvant chemotherapy would be no benefit for these patients.

Adult↗