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Biomedical subjects

T K Lee

Publications and source records attributed to T K Lee.

At least 109 records · Page 6Linked to original sources
PubMed1994

Curvilinear relations between age and hemostatic parameters in Chinese.

The role of hemostatic factors in the pathogenesis of cardiovascular disease has gained much attention recently. Information about hemostatic factors, and their age patterns is sparse for orientals. With the data collected in the Cardiovascular Disease Risk Factor Two-township Study in Taiwan, this study shows that, in general, the older the age, the stronger the tendency toward thrombosis. With advancing age, prothrombin time, activated partial thromboplastin time, and antithrombin-III level decreased steadily; but mean values of fibrinogen, factor VIIc, and factor VIIIc increased. Gender differences in the age patterns of the above factors are carefully described. Curvilinear relations between hemostatic factors and age were demonstrated for adults aged 18 and above for all hemostatic factors studied. This curvilinearity should be taken into consideration when adjusting for the effect of age in data analysis to avoid residual confounding, particularly when the age range of the study subjects is wide.

Adolescent↗
PubMed1994

Seroprevalence study of Helicobacter pylori infection in patients with gastroduodenal diseases.

To investigate Helicobacter pylori (H. pylori) infection in subjects with and without gastroduodenal diseases in Taiwan, IgG antibodies to H. pylori were examined in 136 healthy volunteers, 101 patients with non-ulcer dyspepsia, 122 gastric ulcers, 119 duodenal ulcers, and 161 gastric adenocarcinomas. The seropositivity was highest in duodenal ulcers (87.4%) (p < 0.001, as compared to healthy volunteers), followed by gastric ulcers (76.2%) (p < 0.01, as compared to healthy volunteers), but similar among gastric adenocarcinomas (60.3%), healthy volunteers (58.8%), and patients with non-ulcer dyspepsia (55.5%). Higher acquisition of H. pylori in younger patients with duodenal and gastric ulcers suggests a strong association with H. pylori. No ulcer characteristics, including number, location, and activity, were significantly statistically associated with the seropositivity of H. pylori in gastric and duodenal ulcers. Similarly, the location, extent of invasion, and histology of gastric adenocarcinoma was not significantly statistically associated with the seropositivity of H. pylori.

Adenocarcinoma↗
PubMed1993

Pathogenesis of pancreatic sepsis.

Although pancreatic sepsis is the most common cause of major morbidity and mortality associated with acute pancreatitis, the pathogenesis of such infections is unknown. Since intraperitoneal foci of inflammation are known to promote bacterial translocation, we hypothesized that acute pancreatitis promotes bacterial translocation that leads to infection of the inflamed pancreas and peripancreatic tissues. Non-lethal acute pancreatitis was induced in rats, and the translocation of live bacteria to the pancreas, mesenteric lymph nodes, liver, and spleen was determined. The presence of orally fed fluorescent beads, sensitive inert markers of translocation, was also determined in the pancreas and mesenteric lymph nodes. Live bacteria were recovered from 33% of the pancreata of rats with acute pancreatitis but from none of the control rats. Beads were visualized in 91% of the pancreata of rats with acute pancreatitis but in none of the pancreata from control rats. Beads were not visualized in the mesenteric lymph nodes of rats with acute pancreatitis, suggesting a transperitoneal route of migration. We conclude that acute pancreatitis promotes bacterial translocation leading to transperitoneal infection of the pancreas. These results support the use of selective decontamination of the gut and peritoneal lavage for the prevention of pancreatic infections in acute pancreatitis.

Animals↗
PubMed1993

Successful treatment of ongoing intestinal allograft rejection permits recovery of graft structure and function.

Acute rejection episodes often complicate clinical small bowel transplantation, which prompted us to investigate whether such episodes can be reversed and the intestinal graft salvaged. Inbred Lewis rats that received fully allogeneic Brown-Norway small bowel allografts were treated with cyclosporin A (10 mg/kg) for 5 days, and the drug was then discontinued. Clinical and histologic signs of acute rejection developed, and the animals were subsequently treated with FK 506 (2 mg/kg) on days 14, 16, and 18. Survival was significantly prolonged (201.7 +/- 46.8 days) when compared with animals that were not administered FK 506 (16.5 +/- 0.8 days) or allograft recipients that received no immunosuppressive therapy (10.8 +/- 0.7 days). The histologic changes and functional impairment due to rejection that were observed prior to the start of the FK 506-therapy were reversed. However, biopsy specimens of all animals exhibited features of chronic rejection. This study provides evidence that acute rejection of intestinal allografts can be successfully treated with a short course of FK 506.

Acute Disease↗
PubMed1993

Occlusive and reperfused myocardial infarction: detection by using MR imaging with gadolinium polylysine enhancement.

PURPOSE: To assess the capability of gadolinium polylysine-enhanced cardiac magnetic resonance (MR) imaging in depicting normal and ischemic myocardium during occlusion and reperfusion of the left anterior descending artery. MATERIALS AND METHODS: Contrast-enhanced MR images were obtained in 18 cats during 90 minutes each of occlusion and reperfusion. The change in signal intensity (SI) was compared among normal myocardium and central and peripheral ischemic zones. Results were compared with those of 2,3,5-triphenyltetrazolium chloride staining. RESULTS: During occlusion, the ischemic zone lacked enhancement while normal myocardium had gradual enhancement. During reperfusion, the ischemic zone had strong enhancement. In cats with large infarction, the central and peripheral ischemic zones had intermediate and high SI, respectively; in cats with focal or no infarction, the entire ischemic zone had high SI. CONCLUSION: Occlusive and reperfused myocardial infarction can be detected at gadolinium polylysine-enhanced MR imaging by means of differential SI changes in normal myocardium and central and peripheral ischemic zones.

Animals↗
PubMed1993

Combined use of aspirin and heparin inhibits in vivo acute carotid thrombosis.

BACKGROUND AND PURPOSE: Carotid atherosclerotic thrombosis is an important cause of ischemic stroke in Western countries. The therapeutic efficacy of either aspirin or heparin alone in this setting is still controversial. Recently we developed a simple model, the "clamp" method, to induce acute carotid mural thrombosis in vivo in guinea pigs. In this study, we used this model to evaluate the antithrombotic effects of aspirin, heparin, and their combination. METHODS: Sixty-four male guinea pigs were divided equally into control, aspirin, heparin, and combined groups. Physiological saline, aspirin (5 mg/kg body wt), heparin (200 units/kg body wt), or a combination of aspirin and heparin, respectively, was injected via the jugular vein before the use of the clamp method. Thirty minutes after the injection of saline or drug(s), Péan's forceps was used to clamp the carotid artery at a tangent angle for 3 minutes. One hour later, the carotid artery was resected and prepared for observation under a scanning electron microscope or light microscope to evaluate the degree of mural thrombosis. RESULTS: The results showed that the combination of aspirin and heparin had an excellent effect in inhibiting in vivo acute carotid thrombosis (p < 0.001) and was significantly better than the effect of aspirin alone (p < 0.01) or heparin alone (p < 0.01). CONCLUSIONS: Our study clearly demonstrated that the combined use of aspirin and heparin produced a much better antithrombotic effect than either agent alone at sites of carotid endothelial injury when given before the injury. This combined regimen may be useful clinically in acute carotid thrombosis secondary to carotid diseases or carotid endarterectomy.

Animals↗
PubMed1993

Is health care different? Popular support of federal health and social policies.

Over the past several years there has been a striking increase in policymakers' attention to health care reform. This paper explores whether there has been a corresponding shift in popular attitudes and identifies factors that may have changed these attitudes. The first part of the analysis relies on survey data collected between 1975 and 1989 to estimate a set of regression models, relating support for federal involvement in health care, antipoverty programs, and general domestic policies to a set of sociodemographic characteristics. Relative to other federal policies, support for health initiatives grew over this period. During the same period, long-standing differences in support between rich and poor, old and young, educated and uneducated, all narrowed for health care, though they did not for other types of federal policies. The second part of this study explores motivations that might account for these patterns. We identify a half dozen ways in which health care may be viewed as "different," that is, more or less appropriate for federal action. Analysis of survey data from 1987 suggests that there are relatively small differences in the attitudes and perceptions that motivate support for federal health initiatives, relative to federal domestic policies in general. However, there are more striking differences between health programs and more overtly redistributive policies. Compared to redistributive federal programs, support for federal health initiatives are (a) less identified with racial minorities or economically disadvantaged groups, (b) less constrained by notions of individual responsibility, (c) more closely associated with concerns about equal opportunity in American society, and (d) somewhat more constrained by choices between federal and local government. These patterns persist whether or not respondents are politically active and whether they report themselves to be liberal or conservative. We suggest that the growing support for federal intervention in health care, relative to other social policies, is in part an inadvertent by-product of ideological positions popularized during the Reagan and Bush administrations. We draw from these results some predictions about the course of the ongoing debate over federal health policies.

Adult↗
PubMed1993

The anatomy of Nikyo (Aikido's second teaching).

Nikyo is the second teaching of Aikido (ni-two, kyo-teaching, in Japanese). It is a joint-lock technique that results in extreme pain. It allows one to control an opponent by destroying his will to continue fighting. Nikyo is accomplished by flexing and adducting an opponent's wrist producing an instantaneous sharp pain that causes him to fall to his knees involuntarily to alleviate the pressure. The exact etiology of the pain elicited by this technique has been obscure to many practitioners. The usual explanations have been nerve compression, joint capsular stretch, tendon/muscle strain, or partial ligamentous disruption. Studies of a cadaver's wrist have shown that Nikyo forcibly compresses the pisiform bone against the ulna, two bones that do not normally articulate. The intense pain thereby produced results from stimulation of the periosteal nerves in these bony surfaces.

Carpal Bones↗
PubMed1993

Helicobacter pylori infection in a randomly selected population, healthy volunteers, and patients with gastric ulcer and gastric adenocarcinoma. A seroprevalence study in Taiwan.

To investigate the association of Helicobacter pylori and gastric ulcer and adenocarcinoma, IgG antibodies against H. pylori were examined in 823 randomly selected subjects, 92 healthy volunteers, 117 patients with gastric ulcer, and 148 with gastric adenocarcinomas in Taiwan, where the prevalence of gastric adenocarcinoma is high. The seropositivity of this population in Taiwan was 54.4%. Gastric ulcer patients had a higher seropositivity (83.8%) than healthy volunteers (62.0%) and gastric adenocarcinoma patients (62.2%) (P < 0.001). Gender difference, blood type, and habit of smoking were not associated with the seroprevalence in any study groups. Gastric ulcer coexistent with duodenal ulcer had a higher seropositivity (94.7%) (P < 0.05). The seropositivity of H. pylori in gastric adenocarcinoma patients was higher than in healthy volunteers only in younger age and was not associated with histologic type, invasion, and location of major tumors. The results reemphasize the association of H. pylori infection with gastric ulcer but not with gastric adenocarcinoma in Taiwan.

Adenocarcinoma↗
PubMed1993

Recovery from aphasia and conversion of handedness: a case report.

A remarkably rapid and complete recovery from aphasia and conversion from right to left handedness was documented in a hemiplegic individual after surgery for an arteriovenous malformation (AVM) in the dominant hemisphere. The possible mechanisms of recovery were discussed and we have reviewed the literature about the pattern of cerebral dominance. Her rapid recovery could be explained by the co-dominance of the right and left cerebral hemispheres.

Adult↗
PubMed1993

Variations associated with disaggregation methods in DNA flow cytometry.

We investigated the variations in DNA ploidy by flow cytometry (FC) among cell suspensions acquired by different disaggregation methods from the same tumor specimens. Cell suspensions (n = 121) of 40 solid tumors were obtained by mechanical mincing (n = 33), enzymatic digestion (n = 19), in vitro fine needle aspiration (FNA) (n = 34) or scraping (n = 35) of the tumor tissues. Mechanical disaggregation gave the highest cell yield, whereas enzymatic digestion provided the best cell viability. The mean values for the G0/G1 coefficient of variation, DNA indices and percent S phase were not significantly different in cell suspensions obtained with the four methods. However, the yield of malignant cells ranged from 60.4 +/- 5.3% (SEM) (enzymatic) to 82.3 +/- 3.1% (scraping). Tissue aliquots of 32 tumors were disaggregated by three to four methods, and the combined results of DNA ploidy obtained from different cell preparations showed that 22 tumors were nondiploid, but concordance with an abnormal DNA peak was found in only 27.3% (6/22) of the DNA nondiploid tumors. Our results indicate that scraping tumor tissue appears to be the best method for DNA FC since it has the highest percentage (61.3) of DNA nondiploid clones. Also, we believe the multiple samplings may provide comprehensive information on the DNA ploidy of solid tumors.

Biopsy, Needle↗
PubMed1993

Automated solid-phase extraction of opiates from urine (I).

The extraction of morphine and codeine in urine by C18 bonded-phase columns was studied using a fully automated solid-phase extraction system. Extracts of urine were analysed by a high-performance liquid chromatographic method. Recovery of the opiates depends on the urine pH, and the choice of washing solvents and eluent. Studies were carried out on the optimisation of eluent volume by establishing a recovery-time profile for the elution process. Regenerated C18 bonded-phase columns could be re-used with negligible carry-over and insignificant recovery loss. An automated extraction procedure was developed for morphine and codeine in urine with absolute recoveries exceeding 80%.

Chromatography, Liquid↗
PubMed1993

Automated solid-phase extraction of opiates from urine (II). Establishing criteria for the detection of opiate abuse.

Automation in the laboratory was taken one step further with the introduction of automated solid-phase extraction of opiates from urine using C18 bonded-phase columns as an alternative to traditional liquid-liquid partitioning. A comparison of the automated procedure with an established liquid-liquid extraction procedure showed a linear correlation between the two over the concentration range studied. Criteria for the identification of opiate abusers were established to adapt this new methodology to large-scale screening of urine specimens.

Codeine↗
PubMed1992

Mucosal glutamine utilization after small-bowel transplantation: an electrophysiologic study.

A short course of FK 506 after small bowel transplantation averts rejection in the rat and achieves indefinite survival of the recipient whose nutritional status is dependent on the function of the intestinal graft. Ex vivo electrophysiologic studies using the Ussing Cell were conducted to delineate functional competence of the graft by evaluating mucosal ion transport and glutamine utilization. Orthotopic small-bowel transplantation was performed in Lewis (LEW) rats as recipients of either Brown-Norway (BN) allografts or LEW syngeneic grafts. Allograft recipients received FK 506 either as a short course (2 mg/kg on Day 0-4 after transplantation) or continuously (2 mg/kg Day 0-4, then 0.5 mg/kg weekly). Ileal mucosa was harvested from small bowel grafts 9 and 60 days after transplantation and mounted in the Ussing Cell containing Hanks' balanced salt solution with/without L-glutamine (20 mM). Transmembrane potential difference (PD), which represents mucosal active ion transport, and mucosal resistance, an index of membrane integrity, were recorded. Nine days after transplantation, mucosal PD was the same in the ileum from syngeneic grafts, allografts treated with FK 506 and normal LEW and BN rats, and the addition of glutamine increased PD equally in all groups. In comparison, PD was markedly decreased in allografts undergoing rejection, and the glutamine response was blunted. Sixty days after transplantation, mucosal PD was reduced in allografts treated with a short course of FK 506, but normal in allografts receiving continuous immunosuppression with FK 506 and in syngeneic grafts. A decrease of mucosal resistance was not a feature of rejection nor a sequel of limited FK 506 therapy. Our data indicate that allograft rejection results in a significant decrease in mucosal PD and a poor response to glutamine. Control of rejection by FK 506 preserves normal electrophysiologic responses of the allograft mucosa.

Animals↗
PubMed1992

Process development for the recovery and purification of recombinant protein G.

The domains of protein G from streptococcus which bind immunoglobulin G have been cloned and expressed in Escherichia coli (Fahnestock et al., 1986). Because protein G binds to several animal immunoglobulin G's, it has many immunochemical applications. This report describes process development for large-scale production of this recombinant protein G (also known as GammaBind G). In 200 l cultures of E. coli, this protein G variant was released from the cell into the culture medium by heating at 80 degrees C for 10 min. The concentration was monitored by either a competitive enzyme-linked immunoassay or a liquid chromatographic assay. Cross-flow microfiltration with 0.22 micron membrane was used to remove the cells. The protein G-rich permeate from the cross-flow microfilter was purified by affinity chromatography using a 5 l column of IgG-Sepharose 6 Fast Flow, which yielded 16-18 g of protein G per column cycle. The pools of purified protein G were concentrated and desalted using ultrafiltration. The salt-free protein G was then lyophilized as bulk product. The overall recovery through the entire process was 50-64%. The analysis of the final product included sodium dodecyl sulfate polyacrylamide gel electrophoresis, UV-visible spectrum, high performance gel filtration, endotoxin level and binding efficiency to human IgG Sepharose.

Bacterial Proteins↗
PubMed1992

Perinatal mortality and prevalence of major congenital malformations of twins in Taipei city.

In order to examine perinatal mortality and prevalence of major congenital malformations in twins, deliveries in four teaching hospitals in Taipei City were studied. Among a total of 73,264 deliveries from October 1985 to June 1989, there were 844 pairs of twins. The zygosity of the twin pairs was determined by sex, placentation and 12 red blood cell antigens. There were 482 MZ and 252 DZ twin pairs identified, but the zygosity of a further 110 twin pairs was indeterminable due to lack of information on plancentation and/or blood types. A total of 4,573 singletons delivered in one study hospital from July 1986 to June 1987 were also studied as controls. The perinatal mortality rate was 7.5% for MZ twins, 1.4% for DZ twins, and 0.7% for singletons. The concordance rate of perinatal death was significantly higher in MZ (60%) than in DZ (0%) twins. The prevalence of major congenital malformations was 2.7% for MZ twins, 1.0% for DZ twins, and 0.6% for singletons. The concordance rate of major congenital malformations was 18% for MZ twins, but no DZ pair was concordant in any major congenital malformation. The concordance rate of facial clefts was 29% for MZ twins. There were 2 sets of conjoined twins giving a prevalence rate of 2.7 per 100,000 deliveries. These findings showing the prevalence of perinatal mortality and major congenital malformation to be highest in MZ twins, intermediate in DZ twins and lowest in singletons, suggest the importance of intrauterine environments in the determination of perinatal mortality and congenital malformations.

Congenital Abnormalities↗
PubMed1992

Secular trend and associated factors of twinning in Taiwan.

Delivery records of public hospitals and local health centers were analyzed to investigate the secular trend of multiple births from 1955 to 1990 in Taiwan. Twinning rates decreased gradually from the late 1950s to 1973, slightly increased and remained stable from 1974 to 1980, and then increased strikingly from 1981 to 1990. During the study period, MZ rates were consistently higher than DZ rates except in 1986 when a higher DZ rate was observed. The highest MZ rate of 7.7 per 1,000 deliveries was observed in 1985, while the highest DZ rate of 4.6 per 1,000 deliveries was observed in 1986. The triplet incidence rate also declined from the early 1960s to 1973 and then increased markedly from 1974 to 1990. A case-control study including 482 MZ and 252 DZ twin pairs and 1,496 singletons was carried out in four teaching hospitals in Taipei City between October 1985 and June 1989 to examine factors related to twinning. The zygosity of twin pairs was determined by sex, placentation and red blood cell antigens. Multiple logistic regression analysis showed that the higher the maternal age, the lower the MZ and DZ rates, while the higher the parity, the higher the rates. There was no association of paternal age or of maternal educational level with twinning rates.

Adult↗