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Biomedical subjects

K M Chen

Publications and source records attributed to K M Chen.

At least 73 records · Page 4Linked to original sources
PubMed1994

Topographic investigation of brain atrophy in parkinsonism-dementia complex of Guam: a comparison with Alzheimer's disease and progressive supranuclear palsy.

The topographic distribution of brain atrophy in nine patients with parkinsonism-dementia complex of Guam (Guam PDC) was evaluated quantitatively, and compared with that in six Japanese patients with Alzheimer's disease or senile dementia of Alzheimer type (AD), five Japanese patients with progressive supranuclear palsy (PSP), and nine Japanese control subjects. Characteristic features of Guam PDC were as follows: (1) severe atrophy of the frontal and temporal cortex with relative preservation of the white matter; (2) atrophy of the tectum, tegmentum and cerebral peduncle of the midbrain, and (3) atrophy of the tegmentum and base of the upper pons. In contrast, sectional areas of the tectum and cerebral peduncle of the midbrain were relatively well preserved in PSP, while in AD there was no significant atrophy in the brain stem.

Aged↗
PubMed1994

Occult breast carcinoma presenting with axillary lymph node metastases: report of two cases.

We report two unusual cases of occult breast carcinoma in which extensive axillary node metastasis was the first manifestation. A microscopic lesion of intraductal carcinoma was found in the tissue of one resected breast and a small infiltrative ductal carcinoma, 0.8 cm in size, in the greatest dimension in the other. Extensive metastasis was found in 26 out of 51 and 10 out of 15 axillary nodes, respectively. Results of immunohistochemical stains for estrogen and progesterone receptors on fresh frozen sections were negative for metastatic nodes in one case and both were positive for primary and metastatic tumors in the other. We review the literature and discuss the diagnosis, management and prognosis in female patients presenting with metastatic carcinoma in the axillary nodes.

Adult↗
PubMed1994

Immunohistochemical analysis of estrogen and progesterone receptor and neu expression in breast carcinoma.

To elucidate the frequency and biological significance of the expression of estrogen receptor (ER), progesterone receptor (PR), and neu oncogene in breast carcinoma, ER, PR and neu proteins were examined by immunohistochemical assay in 74 Taiwanese patients with breast carcinoma. In total, 56.8% and 48.7% of breast carcinoma were positive for ER and PR, respectively. In 91.9% of cases, the patients were either positive (48.7%) or negative (43.2%) for both ER and PR. Well differentiated carcinoma had higher frequencies of ER- (p < 0.02) and PR-positivities (p < 0.01). The ER and PR status did not correlate with tumor size, stromal lymphoid infiltration or axillary node status. The neu oncoprotein was expressed in 25.7% of breast carcinomas, but did not correlate with ER and PR status, tumor size, tumor grade, lymphoid infiltration, or axillary node status.

Biomarkers, Tumor↗
PubMed1994

[Reduced-size liver transplantation in mini pigs].

Liver transplantation as therapy for end stage hepatic disease has developed rapidly since the 1980s. Pediatric candidates, however, have suffered the greatest delay in receiving suitable organs, with 20% to 50% of deaths occurring in patients on the waiting list. To overcome the shortage of young donors, surgeons are currently experimenting with the technique of partial liver transplantation. In this study, 10 pairs of mini pigs were used for partial liver transplantation. UW (University Wisconsin) solution was used for liver preservation after the liver was procured. The left lobe was separated using the intact vascular branches method. The raw surface was covered with histoacryl orthotopically in the smaller pig in a position of 60 degrees-90 degrees counter clockwise rotation. The results were: (1) six of the ten transplanted pigs survived for more then one week without any immunosuppressive drugs; (2) the mean operation time was 5h 18 mins; (3) the mean ischemic time of the donor liver was 6h 25 mins; (4) the liver functions tests were acceptable until the day before death. Based on this experiment, we suggest that partial liver transplantation is feasible, both technically functionally.

Animals↗
PubMed1994

[Molecular recognition between GlcNAc and Plasmodium falciparum merozoites].

In this study p-aminophenyl-2-acetamido-2-deoxy-beta-D-glucopyranoside was bound covalently to bovine serum albumin (BSA) to form neoglycoprotein (GlcNAc-BSA). The antigenicity of BSA and the pyranose structure of the sugar was preserved. By using the neoglycoprotein antibody against BSA and staphylococcal protein A-gold (SPA-gold), Plasmodium falciparum FCC-1/HN merozoites were immunolabeled. The labelled sample was observed under transmission electron microscope (TEM). The TEM pictures showed that colloidal gold pellets were distributed all over the merozoite surface. This is the first report on the direct experimental evidence of molecular recognition between GlcNAc-BSA (or GlcNAc) and Plasmodium falciparum merozoites. But free GlcNAc or even GlcN can inhibit the immunolabeleation. The results support the hypothesis that, besides N-acetylneuraminic acid, GlcNAc is involved as another recognized site on GPA for Plasmodium falciparum. Thus we further confirmed that N-acetyl of GlcNAc is not necessary for the recognition.

Acetylglucosamine↗
PubMed1993

Catecholamines: important factors in the increase of oxidative phosphorylation coupling in rat-liver mitochondria during the early phase of burn injury.

Thirty minutes after Sprague-Dawley rats had been injected subcutaneously with epinephrine or norepinephrine, the respiratory control ratio (RCR), the rate of O2 consumption in state 3 and the rate of ATP formation in liver mitochondria succinate respiratory chain were increased. The rate of O2 consumption in state 4 was increased or only slightly increased. When the rats were injected with the adrenergic blocking agents, timolol or phenoxybenzamine, 1 h before the burn, the activities of the succinate respiratory chain was partly inhibited 30 min postburn. Compared with our previous results, it can be suggested that catecholamines may play an important role in the increase of oxidative phosphorylation coupling in the early phase of burn injury.

Animals↗
PubMed1993

Laparoscopic-guided gastrostomy.

Gastrostomy is commonly performed in patients who have esophageal stenosis or difficulty in swallowing. The fact that most patients who require a gastrostoma are usually malnourished or debilitated urges surgeons to seek a convenient and reliable method for performing the operation. Percutaneous endoscopic gastrostomy (PEG) was introduced into clinical practice and recommended as the procedure of choice in the 1980s. However, PEG was not indicated and only traditional open gastrostomy was considered for those who had obstruction in their oroesophageal canal. We describe a technique for placement of a gastrostomy tube under laparoscopic control. The technique is easily mastered, requires equipment routinely used in laparoscopic control. The technique is easily mastered, requires equipment routinely used in laparoscopic surgery, and can be used by surgeons untrained in gastroendoscopy. When performed properly, the method is accurate, economic and reliable.

Gastrostomy↗
PubMed1993

Secular changes in the clinical manifestation and pathologic pattern of early gastric cancer in Taiwan.

To investigate whether there has been a time trend change in the percentage of early gastric cancer to gastric cancer and the clinicopathologic features of early gastric cancer in Taiwan, we reviewed 208 patients diagnosed between 1964 and 1992. Patients were divided into group I from 1964-1980 (n = 106) and group II from 1981-1992 (n = 102). The percentage of early gastric cancer among total gastric resections in group II (14.7%) did not differ from group I (12.7%; p = 0.19). Epigastralgia (58.2%) was the most common complaint; 11.8% (12/102) of cancers in group II were incidentally detected by endoscopy. Endoscopy provided a better diagnostic aid than did radiology. Tumors were frequently located in the antrum (50.9%) with a mean diameter of 2.8 cm. Small cancers of less than 1 cm in diameter were more prevalent in group II (37.3%) than group I (10.4%; p < 0.001). Cancers of the elevated type (17.8%) were uncommon in contrast to depressed ones (82.2%; p < 0.001). The frequency of mucosal carcinoma (51.0%) was similar to submucosal carcinoma (49.0%). Mucosal carcinoma had less lymph node metastases (3.1%) than submucosal carcinoma (12.2%; p < 0.05) with an overall frequency of metastases of 7.5% (14/186). The five-year survival rate of group I (91.7%) was not statistically different from group II (94.6%). We concluded that, except for the symptomatology and the ability to diagnose, the clinicopathologic features of early gastric cancer were similar between these two time periods. Repeated investigation of suspicious lesions and endoscopic screening on asymptomatic subjects may increase the rate of detection and thus guarantee a favorable outcome.

Adult↗
PubMed1993

Effects of direct lytic factors from southern Chinese cobra venom on Ca2+ movement in rabbit aorta strip.

The purified direct lytic factors (DLF) from southern Chinese cobra (Naja naja atra) venom induced a contractile response in Ca(2+)-free Krebs' solution and a further increase in the tension following a subsequent addition of Ca2+ into bath. After depletion of intracellular Ca2+ pool by phenylephrine, DLF failed to induce any contractile response. In 45Ca2+ experiments, DLF increased both 45Ca2+ release and 45Ca2+ influx. Procaine 2 mmol.L-1 decreased the DLF induced 45Ca2+ release and 45Ca2+ influx by 67 +/- 23% and 46 +/- 32%, respectively. Nifedipine and verapamil 1 mmol.L-1 markedly inhibited the contractile response and the 45Ca2+ influx induced by DLF. These results suggest that DLF induces extracellular Ca2+ entry through voltage dependent Ca2+ channel and Ca2+ release from the intracellular Ca2+ pool which is sensitive to phenylephrine.

Animals↗
PubMed1992

Lymphokinetic monitoring of a liver transplant recipient treated with OKT3.

Orthotopic liver transplantation was performed on a 48-year-old female patient with end-stage liver disease due to primary biliary cirrhosis. A course of OKT3 (5 mg/kg intravenously for 14 days) was given as immunosuppressive therapy. Lymphocyte population, T lymphocyte subsets and the lymphokine level in the peripheral blood were serially measured. Total T cells disappeared in the peripheral circulation within 10 minutes after an injection of OKT3. Helper T cells and suppressor T cells were also suppressed during the course of treatment. The ratio of T4/T8 declined from 2.5 to around 1.3. The serum interleukin-2 and the interleukin-2 receptor did not change markedly during treatment. The serum neopterin level increased after discontinuation of OKT3. The anti-mouse OKT3 antibody increased after the ninth day of OKT3 treatment. OKT3 showed potent T cell suppressive activity.

Female↗
PubMed1992

[Factors in recurrence after curative resection of rectal cancer].

Data on 409 Patients who had a curative resection for rectal cancer at the National Taiwan University Hospital between 1977 and 1989 were analysed to determine the independent effect on recurrence. In our series, the total operative mortality rate was 1.7% and the resectability rate was 88.1%. For these cases who received curative resection, the overall 5-year survival rate was 62.6%. The 5-year survival rate varied according to the Dukes' stage: stage A, 96.4%; stage B, 73.3% and stage C, 39.6%. The total recurrence rate after curative resection was 35.9%, including local recurrence 18.3%, systemic recurrence 12.0%, and combined recurrence 5.6%. According to Dukes' staging system, the recurrence rate for stage A, B and C were 0%, 22.4% and 63.8%, respectively. We used Cox's regression model to analyse the patients characteristics and pathological variables on recurrence and to assess the independent influence of each when all other factors were held constant. The pathological stage of the cancer had the strongest association. Other variables found to have an independent yet significant importance, were CEA level and tumor size. The identification of the patient group, at a high risk of recurrence, might promote a more judicious selection for surgical procedure and trials of adjuvant therapy.

Adult↗
PubMed1992

Rat liver regeneration after partial hepatectomy: effects of insulin, glucagon and epidermal growth factor.

This study evaluated the role of insulin, glucagon and the epidermal growth factor (EGF) on liver regeneration after partial hepatectomy. Male Wistar rats, weighing approximately 200 g, were used. A partial hepatectomy, with resection of the medial and left lateral lobes (67.31%), was performed on the control group and seven hormone-treated groups: insulin, glucagon, EGF, insulin plus glucagon, insulin plus EGF, glucagon plus EGF, and a combination of the three hormones. The hormones were administered subcutaneously two days prior to the partial hepatectomy. The groups administered insulin were allowed to drink 20% glucose in water. Another group of rats received simulated operations, i.e., only a laparotomy was performed. The rats were killed at six, 24, 48 and 72 hours after the operation. Remnant liver weight, deoxyribonucleic acid (DNA) content, rate of DNA synthesis, mitotic index, blood glucose and serum insulin levels were measured. The results showed that: 1) the effects of single hormone administration on posthepatectomy liver regeneration were not obvious; 2) combined administration of insulin and glucagon increased the weight of the remnant liver, the DNA content, and the rate of DNA synthesis; 3) the combined administration of insulin, glucagon, and EGF increased the regeneration based on the remnant liver weight and mitotic index; and 4) there was no concordance between the change in blood glucose levels and the effect of hormones during liver regeneration.

Animals↗
PubMed1992

Surgery in cholangitis: bacteriology and choice of antibiotic.

Owing the frequent occurrence of intrahepatic stones in orientals, cholangitis presents a real problem. Surgery and antimicrobial drug therapy are the main forms of treatment. A retrospective study of choledochotomy, including biliary tract surgery, performed between July 1987 and June 1990, was conducted. Cases with negative common duct exploration during cholecystectomy were excluded. Among 186 cases, 128 (68%) had positive bile growth, which was defined as cholangitis. Sepsis-related complications occurred in 51 patients (27.4%), including 3 surgical deaths, 30 wound infections, and 18 others. The complication rate was higher in the cholangitis group than in the negative group (37.5% vs. 5.2%). However, if peri-operative antibiotics were effective against the cultured bacteria species, the complication rate was 16.9%; if not, the complication rate was 85.3%. For the different-generation cephalosporins used in the peri-operative period, the complication rates were 32.2%, 20.8%, and 27.6% each for 1st, 2nd, and 3rd generation cephalosporins, with no statistically significant differences. In microbiological study, polymicrobial infection was the rule. On average, 2.3 species were grown from each specimen. Enterococcus proved the most important species with a 54% culture rate. E. coli and Pseudomonas were important gram-negative bacilli, with culture rates of 46.1% and 39.1%, respectively. Anaerobic species were cultured in 12.3% of the patients. For good coverage of cholangitis prior to operation, the proper antibiotic should have potency against gram-positive Enterococcus, gram-negative bacilli, especially Pseudomonas and E. coli, and anaerobic species, especially Bacteroides.

Adult↗
PubMed1991

Alpha 1-adrenoceptors mediate the responses to BHT-920 and rauwolscine in dog mesenteric artery after partial depolarization by KCl.

In normal (5 mM KCl) HEPES buffer solution, BHT-920 and rauwloscine did not produce any contractile responses in dog mesenteric artery strips. However, when the preparation was bathed in 20 mM KCl HEPES buffer solution, BHT-920 and rauwloscine evoked significant contractile responses. These effects were markedly inhibited by parazosin which caused a parallel shift to the right of the concentration-response curve to BHT-920. In 45Ca uptake experiments carried out in the 20 mM KCl HEPES buffer solution BHT-920 and rauwolscine significantly increased 45Ca influxes which were reduced by prazosin. These results suggest that postsynaptic alpha 1-adrenoceptors in dog mesenteric artery mediate the contractile responses and the 45Ca influxes induced by BHT-920 and rauwloscine after partial depolarization by 20 mM KCl.

Adrenergic alpha-Agonists↗
PubMed1991

Odor identification deficit of the parkinsonism-dementia complex of Guam: equivalence to that of Alzheimer's and idiopathic Parkinson's disease.

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↗