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Biomedical subjects

K M Chen

Publications and source records attributed to K M Chen.

At least 91 records · Page 5Linked to original sources
PubMed1991

Alterations of high-energy phosphate, serum energy substrate and their metabolites after partial hepatectomy in rats.

Partial hepatectomy with resection of the median and left lateral lobes was performed on our experimental rat group. Another group undergoing a sham operation only was compared. The rats from both groups were allowed to eat freely after their operation. Rats were sacrificed at 6, 24, 48, and 72 hours post-operatively. Remnant liver weight, deoxyribonucleic acid (DNA) synthetic rate, DNA content, and mitotic index were chosen for monitoring regeneration. Adenosine triphosphate (ATP) and creatine phosphate (CP) in liver tissue, blood glucose, serum free fatty acid (FFA), total ketone bodies, and ketone body ratio (KBR) were measured. The results showed that: (1) the high-energy phosphate (ATP and CP) in liver tissue decreased sharply in the early phase after partial hepatectomy and recovered gradually; (2) the decrease in creatine phosphate was more marked than ATP; (3) the blood glucose level decreased, while the serum metabolites of FFA markedly increased in the early posthepatectomized phase; and (4) the KBR was markedly depressed in this early postoperative period.

Adenosine Triphosphate↗
PubMed1991

Primary malignant tumor of the small intestine.

The records of 101 patients with primary small intestinal malignant tumor at NTUH, collected from 1960 to 1989, were reviewed. These patients represented 1.2% of the patients with gastrointestinal cancer at NTUH over the same period. Fourty-two (41.6%) of the cancer patients had lymphomas, 30(29.7%) had adenocarcinomas, 26 (25.7%) had leiomyosarcomas, and 3(3.0%) had carcinoid tumors. The average age at cancer presentation was 47.5 years (range from 3 to 96). The lymphoma patients had an average age of 35.1 years, while adenocarcinoma patients averaged 60.4 years of age. Leiomyosarcoma and carcinoid tumors averaged 51.2 years and 59 years, respectively. There were 65 male patients and 36 female patients, and there was a male predominance in all groups except for the leiomyosarcoma group which had an equal sex ratio. Generally speaking, the incidence rate for the areas involved were similar in the duodenum, jejunum and ileum. However, adenocarcinomas were more common in the duodenum (53%) and 45% of lymphomas were found in the ileum, as were the carcinoid tumors (66%). The most common presenting symptom was abdominal pain (62%), with bleeding second (32%). Obstruction and palpable mass together were present in 29% of the cases. Body weight loss was found in 25% of patients, and 14% of the patients presented with acute abdomen due to intestinal perforation. Laparotomy was the most common diagnostic procedure (60%). Preoperative diagnoses were possible in cases of duodenal and upper intestinal malignancies, but were rarely possible in patients with lower intestinal malignancies. Sixty-eight patients (68%) underwent tumor resection for palliation or cure. The operation mortality was 4%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Factors affecting local or regional recurrence in breast cancer.

Between 1975 and 1989, 535 patients with infiltrating ductal carcinoma of the breast in various clinical stages were treated by modified radical mastectomy and axillary node clearance, followed by chemotherapy, endocrine therapy or radiotherapy. Median follow-up was 3 years (5 months to 15 years). Fifty-eight local or regional recurrences occurred. The 5-year and 10-year actuarial risks of breast recurrences were 14% +/- 2% and 23% +/- 4%, respectively. Using multivariate analysis with the Cox regression model, the most important multivariate-adjusted independent contributing factors to local or regional breast recurrences were age less than or equal to 40 (p less than 10(-4), relative risk = 2.94), positive lymph nodes greater than 3 (p less than 10(-3), relative risk = 2.57), and multicentricity (p = 0.044, relative risk = 2.73). The overall 5-year survival rate of recurrent patients was 64 +/- 7%, and was significantly worse when breast recurrence occurred in the first 18 months after operation. The multivariate-adjusted relative risk of death for early recurrence was 4.35 (p = 0.04). The unadjusted 5-year survival rate for early recurrence was 58% +/- 1%, and 85% +/- 8% for late recurrence. This study confirms the relationship between young age and low breast control rates. It emphasizes the adverse prognosis of early breast recurrences as compared to the relatively favorable outcome of late recurrences.

Adult↗
PubMed1991

Tumoricidal activity of interferon-r activated peripheral monocytes in colorectal cancer patients.

Peripheral blood monocytes obtained from 8 colorectal cancer patients and 6 normal controls were incubated in vitro with interferon-r (IFN-r) in the presence of bacterial lipopolysaccharide (LPS). The cytotoxic properties of the monocyte were determined subsequent to the interaction with radiolabeled autologous, allogeneic, as well as cultured colorectal cancer cells. Monocytes from normal controls and all colorectal cancer patients were activated in vitro to become tumoricidal; monocytes lysed tumorigenic cells but not nontumorigenic cells. Activators of protein kinase C (e.g. phorbol esters, PMA) and Ca2+ ionophores (A23187) when added alone did not effect the activation state of the monocyte. Whereas, PMA and A23187 cooperatively reproduced the ability of IFN-r to prime monocytes for tumoricidal activity. In the presence of PMA, A23187, and EGTA, the addition of excessive Ca2+ was sufficient for priming, whereas the addition of excessive Mg2+ was much less efficient. Priming by IFN-r, however, was not blocked by EGTA. An efflux of Ca2+ from preloaded monocytes was significantly increased by A23187 and by IFN-r. Quin-2/AM, an intracellular chelator of Ca2+, blocked priming by IFN-r. The results suggest that priming of monocytes for tumoricidal function by IFN-r may be involved in the activation of protein kinase C and mobilization of intracellular Ca2+.

Aged↗
PubMed1991

Olfactory dysfunction in three neurodegenerative diseases.

Olfactory dysfunction is among the first signs of Alzheimer's disease (AD), idiopathic Parkinson's disease (PD), and the parkinsonism-dementia complex (PDC) of Guam. We have recently demonstrated that the odor identification and detection deficits of patients with PD are equivalent to those of patients with mild AD when subtle differences in cognitive function are statistically controlled for by analysis of covariance. In contrast, patients with progressive supranuclear palsy (PSP) and patients with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism evidence olfactory function much more similar to that of normal controls. In the present study, we administered the University of Pennsylvania Smell Identification Test and the Picture Identification Test to 24 patients with early signs of the PDC of Guam and statistically compared their test scores to those of 24 early-stage AD and 24 early-stage PD patients of similar age and gender from the United States mainland. Although the PDC group evidenced slightly more difficulty in identifying pictures than did the other 2 groups, the odor identification deficit associated with this disorder was of the same magnitude as that observed in AD and PD, suggesting that olfactory testing cannot be used to distinguish among these 3 diseases and that the olfactory dysfunction of these disorders may reflect a common neurologic substrate.

Adult↗
PubMed1990

Functional changes of the NADH respiratory chain in rat-liver mitochondria and the content changes of high-energy phosphate groups in rat liver and heart during the early phase of burn injury.

Using glutamate plus malate as substrates, the respiratory control ratio of liver mitochondria from burned male Sprague-Dawley rats with full skin thickness burns covering 20 per cent of the body surface area were increased at 45, 60, 75 and 90 min and using alpha-ketoglutarate, were increased at 60 and 75 min after burning, the peak being at 75 min postburn. The ADP/O ratio and the rate of ATP formation were also increased at about 75 min postburn and the ATP content in liver was increased at 120 min following burning. The ATP and creatine phosphate contents in heart tissue were increased at 120 min and at 105, 120 and 135 min postburn respectively. A sham-injured group acted as control. All the results suggested an increased oxidative phosphorylation coupling in some organs during the early phase of burn injury.

Adenosine Diphosphate↗
PubMed1990

Proliferation, interleukin-2 production and receptor expression in peripheral blood mononuclear cells from colorectal cancer patients.

Peripheral blood mononuclear cells (PBMC) were cultured with phytohemagglutinin (PHA) in 46 colorectal cancer patients and 27 normal controls. By collectively comparing the cancer patients with the normal controls, the cancer patients had: (1) decreased interleukin-2 (IL-2) secretion, (2) fewer interleukin-2 receptor (IL-2R) expression on cell surface, and (3) less 3H thymidine incorporation. The ability of the phorbol ester, phorbol 12-myristate 13-acetate (PMA), and the calcium ionophore, A23187, in co-stimulation with PHA, to enhance the IL-2 secretion, IL-2R expression and 3H thymidine incorporation were studied in the PBMC of colorectal cancer patients. By adding A23187 into the PHA-stimulated PBMC from colorectal cancer patients, IL-2 production and IL-2R expression were increased up to levels equal to that obtained in PHA-stimulated PBMC from normal controls. Whereas there was no significant increase in proliferative response. However, PMA has no effect on all three parameters. A23187 is known to be effective in elevating cytosolic free Ca2+ and PMA is regarded as an activator of protein kinase C. Therefore, we may conclude that the impairment of IL-2 production and IL-2R expression in PHA-stimulated cultures is mainly due to failure of the free Ca2+ release which can be repaired by A23187. While protein kinase C activation may not be impaired since its deficit in IL-2 production and IL-2R expression can not be corrected by PMA.

Aged↗
PubMed1990

A technique using V-shaped transmural suture fixation in percutaneous endoscopic gastrostomy.

A new method of percutaneous endoscopic gastrostomy (PEG) using V-shaped transmural suture fixation was performed on 2 patients with advanced carcinoma. This method secures the gastrostoma in a way superior to the conventional technique. It facilitates exchange of the catheter and avoids potential morbidity caused by peritoneal leakage even when tube feeding has been initiated in the early post-insertion stage. Inadvertent complications of hematoma formation and necrotizing fasciitis can also be prevented.

Aged↗
PubMed1990

Liver regeneration after partial hepatectomy: effects of glucose and branched-chain amino acid.

The phenomenon of liver regeneration has been observed within several days after partial hepatectomy, though there is still much controversy as to its initiation, regulation, and the control factors behind it. Male Wistar rats weighing around 200 g were used as subjects in this study. Partial hepatectomy with resection of the median and left lateral lobes (67.31%) was performed. High glucose, low glucose, or high or low branched-chain amino acid (BCAA) solutions were given intravenously 2 days prior to the partial hepatectomy. The rats were sacrificed at 6, 24, 48, and 72 hours after the operation. Remnant liver weight, Deoxyribonucleic acid (DNA) content, DNA synthesis rate, and mitotic index were chosen as markers for comparing the effects of the glucose and branched-chain amino acid solutions on liver regeneration. The results were as follows: (1) following removal of two-thirds of a rat's liver, DNA synthesis increased abruptly, peaking at 24 hours, the mitotic index reached a maximum at 48 hours, and the remaining lobes had doubled in size by 48 hours and had attained around 90% of the normal liver weight at 72 hours; (2) judging by the results of the remnant liver weight, DNA content, and DNA synthesis rate, the low glucose infusion rates showed the worst regenerative condition; and (3) the only effect of BCAA on liver regeneration observed was that low BCAA infusion rates resulted in a lower DNA content in the remnant liver.

Amino Acids, Branched-Chain↗
PubMed1990

Aortomesenteric bypass using autogenous saphenous vein graft for superior mensenteric artery aneurysm: report of a case.

We report a 62-year-old man who had symptoms of abdominal angina and was diagnosed preoperatively with a superior mesenteric artery (SMA) aneurysm. The findings of the CT scan and angiography revealed a 3 X 4 cm saccular aneurysm at the proximal site of the SMA. During abdominal exploration, a weak pulsation of the SMA branches distal to the aneurysm was felt. The aneurysmal cavity was full of old thrombi. Brisk retrograde bleeding from the orifices of the connecting collaterals was seen after removal of the thrombi. Our operative procedures included endoaneurysmorrhaphy, proximal ligation, and distal interruption of the aneurysm. Vascular reconstruction by an aortomesenteric bypass using a segment of autogenous saphenous vein graft was also done. After creating the vein graft bypass, the weak pulsation of the distal SMA branches became normalized. The patient enjoyed an uneventful postoperative course and did not complain of abdominal pain on clinical follow up. Four months later, he received an evaluation including angiography and CT scan, which confirmed that the vein graft was patent and without deformity.

Aneurysm↗
PubMed1990

Evaluation of systemic hemodynamic effects on post-transplant perfusion to renal allograft.

Hemodynamic parameters and post-transplant renal perfusion were evaluated in 24 cadaver kidney transplantation. Cardiac output (CO), systemic vascular resistance (SVR) and mean arterial pressure (MAP), were continuously monitored in each patient via a transesophageal Doppler cardiac output monitor and radial arterial catheter. Seventeen were well perfused (Group 1) after releasing vascular clamps. Six among group 1 presented as the clinical picture of acute tubular necrosis. Seven were poorly perfused (Group 2). Post-anastomotic CO significantly increased in group 1, and decreased in group 2. SVR significantly decreased in group 1, and increased in group 2. MAP were not significantly different between group 1 and 2. Treatments based on hemodynamic derangement were initiated as soon as it was detected. Correction of CO was associated with the improvement of post-anastomotic renal perfusion, while SVR and MAP were not. Among the 7 poorly perfused kidneys, 5 became well perfused before leaving the operating room. The remaining 2 resumed their hemodynamic stability and renal function a few days later after oral captopril was administered. Two among the 6 acute tubular necrosis resumed renal function as long as hemodynamic stability was restored. Our study demonstrates that hemodynamic parameters are parallel to renal perfusion status. Restoration of hemodynamic derangement not only improves renal perfusion but also renal function. It is concluded that hemodynamic instability and graft ischemic time contribute to the variation of post-transplant perfusion to renal allograft. Non-invasive cardiac output monitor is a safe and reliable monitor which we recommend to be used during the operation of kidney transplantation.

Adult↗
PubMed1989

A numerical method for the computation of induced currents inside 3-D heterogeneous biological bodies by ELF--LF electric fields.

A numerical technique, based on the combination of surface-charge integral equations (SCIE) and an impedance network method, has been developed to compute internal electric fields and currents inside 3-D heterogeneous biological bodies with arbitrary grounding impedances induced by ELF-LF electric fields. The method has been applied to a biological concentric-sphere and the numerical results agree well with an existing analytical solution. Numerical results of the induced current inside a simplified heterogeneous model of the human head computed by this method are also presented.

Body Surface Area↗
PubMed1989

Effects of monomeric and polymeric diets on small intestine following massive resection.

Since the introduction of long-term total parental nutrition, it has been possible to raise the survival rate in patients with massive intestinal resection. How to increase the remaining intestinal mucosa hyperplasia in these patients has become the focus of many studies. Early postoperative enteral feeding with exogenous intraluminal nutrition was considered to be one of the most essential factors. The best enteral food pattern, however, is still not conclusive. In this study, we used the animal model of rats with 60% small intestinal resection, giving them different kinds of enteral diets through gastrostomy tubes. The monomeric diet included amino acid, glucose, disaccharide, and triglyceride. The polymeric diet included the usual source of nutrition such as protein, polysaccharide, and fat. The rats were killed three weeks later. Histopathological changes of the remaining bowel and H3 thymidine incorporation to mucosal DNa were measured. We found: (1) hyperplasia of the remaining bowel in the 60% resected rats was definitely increased more than the rats of the sham operation; (2) from the protein content, the DNA content of mucosa cells, the villus height and crypt depth points of view, the polymeric diet fed rats had a better adaptation; (3) on the 21st postoperative day, the DNA synthetic rate was still very high in polymeric diet fed rats, but returned to preoperative levels in rats fed with a monomeric diet. Our conclusion of this study is that a polymeric diet can contribute to a better intestinal mucosa regeneration than a monomeric diet in the rats with massive intestinal resection.

Adaptation, Physiological↗
PubMed1989

A case of acute superior mesenteric embolism successfully treated by embolectomy.

Superior mesenteric artery embolism is undoubtedly fatal unless operative intervention is promptly performed. The first case successfully managed by embolectomy in Taiwan is reported in this communication. The key to successful management lies in the early suspicion in patients with atrial fibrillation or recent myocardial infarction, presenting with sudden abdominal pain and an unremarkable physical examination. Abdominal angiography is strongly recommended; however, immediate laparatomy should not be postponed if angiography is not available. Early embolectomy is the only useful means of treatment to restore mesenteric circulation, preserve the bowel and rescue the patient. A 56-year-old woman was admitted with a 5-year history of rheumatic heart disease and atrial fibrillation. She had a sudden attack of severe abdominal pain 8 hours after cardiac catheterization. Abdominal examination was not remarkable and plain abdominal X-ray was negative, while bloody stools and leukocytosis developed 7 hours later. Superior mesenteric embolism was highly suspected and emergency laparotomy was performed. Successful embolectomy was carried out through the distal approach and the patient recovered completely without requiring small bowel resection. All branches of the superior mesenteric artery were demonstrated patent upon postoperative angiography.

Embolism↗
PubMed1989

Angiodysplasia of the gastrointestinal tract: report of 5 cases and review of the literature.

With the application of more refined examinations, angiodysplasia is now being recognized as a common cause of bleeding in patients suffering from lower gastrointestinal bleeding. The diagnosis can be made by angiography or occasionally by colonofiberscopy. Angiography allows one to make this diagnosis even after bleeding has ceased. The lesions may not be clinically evident at the time of surgery, and the diagnosis must be made preoperatively to allow for proper treatment. A right hemicolectomy is the treatment of choice since these lesions are frequently multiple and seldom, if ever, occur distal to the proximal transverse colon. The pathophysiology, diagnosis, management and salient features of these lesions are described. The management of 5 patients is discussed.

Adult↗
PubMed1987

Role of surgery in the treatment of primary carcinoma of the liver: a 31-year experience.

During the 31 year period 1954 to 1985, 225 major hepatic resections have been performed for symptomatic primary carcinoma of the liver, of which right hepatic lobectomy was performed in 115, extended right hepatic lobectomy in 11, trisegmentectomy in 2, left hepatic lobectomy in 94, and middle hepatectomy in 3. In addition there were 107 partial hepatic resections for 89 asymptomatic small hepatocellular carcinomas. In the 225 patients undergoing major hepatic resection, the operative mortality was 8.0 per cent. In the 107 patients undergoing partial hepatic resection, the operative mortality was 5.6 per cent. Of the total of 314 hepatic resections for primary carcinoma of the liver, 309 were undertaken for hepatocellular carcinoma and the remaining 5 were carried out for cholangiocarcinoma. All hepatic resections in this series were performed with the finger fracture technique without controlling the hepatic hilar vessels, hepatic ducts or hepatic veins outside the liver, although hepatic clamping and the Pringle manoeuvre were also used in selective cases. Of 207 cases who survived major hepatic resection, 119 cases died within one year after the operation, mainly due to recurrence of cancer in the remaining residual lobe, lung metastasis or late hepatic failure. The 5 year survival rate is 18.0 per cent, 12 patients are still alive and well after more than 5 years and the longest survival is 23 years. Of the 89 patients with small asymptomatic hepatocellular carcinomas, 28 died within one to four years of surgery because of a second new growth.

Adult↗
PubMed1987

A cohort study of amyotrophic lateral sclerosis and parkinsonism-dementia on Guam and Rota.

A prospective study of the incidence of new cases of amyotrophic lateral sclerosis and parkinsonism-dementia was conducted by follow-up of 899 Chamorros in the Mariana Islands who participated in a baseline medical examination and interview in 1968. During a 15-year follow-up period, 28 new neurologically confirmed cases occurred, including 23 with parkinsonism-dementia and five with amyotrophic lateral sclerosis. The low incidence of amyotrophic lateral sclerosis was consistent with the reported disappearance of this disease from the Mariana Islands. However, the continuing high incidence of parkinsonism-dementia was not in agreement with a similarly reported disappearance nor with the hypothesis of a common cause of both diseases. Of 23 selected baseline examination variables, only the preference for traditional Chamorro food was significantly associated with an increased risk of parkinsonism-dementia. A review of the accumulated epidemiologic data on these neurologic diseases in the Mariana Islands did not support the current hypothesis that a chronic nutritional deficiency of calcium is a cause of both amyotrophic lateral sclerosis and parkinsonism-dementia.

Adult↗