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Biomedical subjects

C K Liu

Publications and source records attributed to C K Liu.

At least 19 recordsLinked to original sources
PubMed1995

[The changes of central and peripheral nerve conduction and the effect of thyroxine replacement in thyroidectomized rats].

The aim of this study is to make serial BAEPs and PNCS in hypothyroid rats in order to provide objective and quantitative methods of detecting dysfunction of the central and peripheral nervous system in hypothyroid status and elucidating the relationship between the recovery potential and the duration of hypothyroid status. Thyroidectomy was performed in eighteen naive 5-month-old Sprague-Dawley rats in order to induce hypothyroid status, which was confirmed by RIA study 1-2 months after the surgery. Initial BAEP and PNCS were performed in two groups of the hypothyroid animals 1 and 3 months after thyroidectomy. Following the initial examination, thyroxin replacement therapy was given to each hypothyroid group, and then followed by BAEPs and PNCS at two month intervals, up to twice normal studies or six months after the initiation of therapy. In the BAEP study, the prolonged I-V inter-peak latency was the most consistent abnormal finding in all hypothyroid rats. Delayed peak latencies as well as prolonged I-III and III-V inter-peak intervals occurred when the hypothyroid status was longer than one month. We noted that the longer the hypothyroid status, the more severe the central conduction dysfunction. Nonetheless, these abnormalities always returned to normal after the replacement therapy if the hypothyroid state was shorter than 3 months in duration. For the PNCS study, all groups of thyroidectomized rats showed the normal results. We think the peripheral nervous system of rats may be more resistant to damage by hypothyroidism than the central nervous system.

Animals↗
PubMed1992

A quantitative MRI study of vascular dementia.

We studied the MRI and clinical factors associated with dementia following stroke by quantifying ventricle-to-brain ratio (VBR), anatomic region of infarction, and cortical, subcortical, and white matter areas of infarction in 24 stroke patients with dementia and 29 nondemented stroke patients. The factors that most strongly correlated with dementia were total white matter lesion (WML) area, left WML, VBR, right WML, age, left cortical infarction area, left parietal infarction area, and total infarction area. Using discriminant analysis, these factors correctly classified 28 of 29 nondemented patients and 18 of 24 demented patients. Both cortical and white matter total infarction area measurements were strongly associated with dementia in stroke patients, suggesting that these factors strongly influenced the development of dementia following stroke. There was a strong association between dementia and left- but not right-hemisphere infarction area. The only demographic factor that strongly associated with dementia was age.

Aged↗
PubMed1992

Types of dementia in Taiwan--a prospective study.

We prospectively investigated 100 consecutive inpatients with suspected dementia to evaluate the relative frequency of various types of dementia in a general hospital of Taiwan. Dementia was confirmed in 86 cases (86%) according to the dementia criteria of the third revised edition of the Diagnostic and Statistical Manual of Mental Disorders and Clinical Dementia Rating Scale (greater than or equal to 1). In contrast to the western developed countries, vascular dementia (VD) (35%) was the leading type of dementia, followed by Alzheimer's disease (AD) (27%), mixed VD and AD (MIX) (14%), and other degenerative diseases (10%). Ten cases (11.6%) of potentially treatable dementia were identified and 8 of 10 had good improvement after appropriate treatment. There were significant age differences among patients with MIX, AD and VD (p less than 0.01). Those with MIX were the oldest (72.12 +/- 9.4) followed by AD (69.70 +/- 8.52) and VD (64.81 +/- 9.12). Males were slightly predominant in this series (male:female = 50:36). A comprehensive clinical investigation including laboratory tests, electroencephalography and CT are necessary in the assessment of demented patients in order to make correct etiological diagnoses which lead to appropriate treatment or management of this terrifying syndrome.

Adult↗
PubMed1991

Watershed infarcts, Tc-99m HMPAO SPECT and CT correlation. Case reports.

We report on the use of Tc-99m hexamethylpropylene amineoxime (HMPAO) in watershed infarcts in five patients who had focal neurologic symptoms. Good correlation between Tc-99m HMPAO and CT was found in two patients. In three patients only Tc-99m HMPAO SPECT in a watershed distribution showed a perfusion abnormality that explained the clinical findings. Tc-99m HMPAO SPECT may be more sensitive than CT in the detection of infarctions in the watershed distribution.

Adult↗
PubMed1989

[The effects of metrizamide myelography on electroencephalographic changes].

Metrizamide, a non-ionic water soluble contrast medium, is used in myelography for detecting spinal cord lesions. Because it is an injection in the subarachnoid space, the effects on the central nervous system following metrizamide myelography should be studied. Electroencephalography can offer a non-invasive and objective method for evaluating the functions of the central nervous system. From September to December 1986, 30 cases which had received cervical or lumbar metrizamide myelography were collected. After myelography, in addition to a history review and neurologic examination, electro-encephalography was carried out within 24 hours. If the EEG record revealed abnormal, a series of EEG follow-ups were conducted until recordings were normal. The incidence of clinical adverse effects following Metrizamide myelography was 53.3% and 66.6% respectively in cervical and lumbar injections. No significant difference was found between the two groups. Secondly, the abnormal rate of the EEG record was 40.0% and 60.0% following cervical and lumbar myelography. The difference was also not significant. Lastly, the relation between clinical adverse effects and an abnormal EEG records was poor in cervical metrizamide myelography but good in lumbar myelography. The conclusions suggested by this research that the clinical adverse effects and the abnormal EEG record after metrizamide myelography are transient and are reversible changes. The mechanism of complications following cervical and lumbar metrizamide are different. Although complications may occur following cervical and lumbar metrizamide myelography, it remains a practical method in detecting spinal cord lesions.

Adult↗
PubMed1988

Thromboembolic complications in coronary angiography associated with the use of nonionic contrast medium.

Thromboembolic complications occurred during diagnostic coronary arteriography in three patients in spite of systemic heparinization. These mishaps were associated with the use of a nonionic contrast medium, which is known not to have a significant protective effect on coagulation pathways. If nonionic contrast media are to be used in angiographic studies of critical organs, meticulous technique is imperative, and adequate systemic heparinization is recommended.

Aged↗
PubMed1984

Abnormal isoelectric focusing patterns of serum galactosyltransferase activity in patients with liver neoplasia.

Serum galactosyltransferase activity (GT) has been studied using isoelectric focusing chromatography in normal subjects, in patients with non-neoplastic liver diseases, and patients with liver neoplastic diseases (hepatoma and liver metastases) using isoelectric focusing chromatography. Freshly obtained serum was applied to an isoelectric focusing column containing Ampholine (pH 4-6) and the fractions were assayed using asialo-agalactofetuin as the galactose acceptor. Three peaks of GT activity were found in sera from normal subjects at pH 4.8, 4.95, and 5.1. In contrast, sera from patients with hepatoma or with gastrointestinal adenocarcinoma with liver metastases contained only two peaks of GT activity (pI 4.75 and 4.95). Sera from patients with non-neoplastic liver diseases had similar GT isoelectric focusing patterns as those from normal subjects. These results suggest that the isoelectric focusing patterns of serum GT activity may be useful in characterizing human liver neoplasia.

Adenocarcinoma↗
PubMed1983

Glycosyltransferase alterations are cell type related when human promyelocytic leukemia (HL-60) cells are treated with various inducers of differentiation.

We have assayed glycosyltransferase activities during the granulocytic and macrophage-like differentiation of human promyelocytic leukemia (HL-60) cells. Functional granulocytic differentiation was assayed by the decarboxylation of 2-deoxyglucose in addition to nitroblue tetrazolium reduction. Dimethylsulfoxide (DMSO) treated HL-60 cells, induced to granulocytic differentiation, had higher 2-deoxy-glucose decarboxylation activity, and contained less sialyltransferase (ST), more fucosyltransferase (FT), and more N-acetylglucosaminyltransferase (NGT) activities than untreated cells. HL-60 cells treated with another granulocytic differentiator, retinoic acid, also had higher 2-deoxyglucose decarboxylation activity, and contained less ST, more FT, and more NGT activities than untreated cells. In contrast, cells treated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) reported to differentiate HL-60 to macrophage-like cells, but did not show an increased level of 2-deoxyglucose decarboxylation activity, but contained more galactosyltransferase (GT) and FT activities as compared to untreated cells. These findings suggest that the alterations of glycosyltransferase levels during the differentiation of precursor cells may not depend upon different inducers, but are characteristic of the phenotypic expression of the mature cell type.

Cell Line↗
PubMed1982

Characterization of galactosyltransferase released from human hepatoma cells.

A human hepatoma cell line (SK-H-MA) released a large amount of sialyltransferase (ST) and galactosyltransferase (GT) into the culture medium, whereas cells derived from normal human liver (Chang) released a large amount of GT but very little ST. The characteristics of hepatoma GT were studied since an abnormal GT isoenzyme has been associated with human gastrointestinal neoplasms. Both hepatoma and Chang medium GT activities had an absolute requirement for MnCl2 (25 mmol/l) and a broad optimal pH between 6.5 and 7.0, and were not affected by 0.1% Triton X-100. These two enzyme preparations were inhibited to the same extent by N-acetylglucosamine and N-acetylgalactosamine, while N-acetylglucosamine was 100 times more potent than N-acetylgalactosamine. Various nucleotides inhibited both enzyme activities equally well. Uracil-containing nucleotides were better inhibitors than thymine-containing nucleotides, and other nucleotides were only slightly inhibitory. The most effective inhibitor was UDP. More of the GT activity in hepatoma medium (65%) as compared to Chang medium (35%) bound to concanavalin A-Sepharose, and was eluted with 2.5% alpha-methylmannoside. These results suggest that the GTs from hepatoma and Chang media are not different in their enzymatic activity but may differ in their carbohydrate contents, which may be another manifestation of the neoplastic nature of the hepatoma cell line.

Animals↗
PubMed1980

12-O-tetradecanoyl-phorbol-13-acetate release of glycosyltransferases from human blood cells.

The mononuclear cells separated from human blood by Ficoll-Hypaque centrifugation contained and released sialyltransferase, galactosyltransferase, and fucosyltransferase. Granulocytes contained and released lesser amounts of glycosyltransferases, whereas platelets released more fucosyltransferase than sialyltransferase or galactosyltransferase. When mononuclear cells were incubated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA), the release of these three glycosyltransferases increased two- to six-fold, and cell suspension glycosyltransferase activities decreased 10-50%. Mononuclear cells were fractionated into lymphocytes and monocytes using baby hamster kidney cells microexudate-coated flasks. TPA stimulated the release of glycosyltransferases from lymphocytes but not from monocytes. The release of glycosyltransferases by TPA-treated mononuclear cells was not further stimulated by reincubation with TPA and was not affected by puromycin, cAMP, or cGMP. Concanavalin A, a mitogenic stimulator of lymphocytes, also stimulated the release of glycosyltransferases from mononuclear cells, but to a lesser extent. TPA did not stimulate the release of 5'-nucleotidase or decrease its activity on the cell pellet. Triton X-100 (0.2%) stimulated the release of glycosyltransferases to the same extent as TPA, but also caused the release of 5'-nucleotidase. [(3)H]TPA bound specifically and reversibly to mononuclear cells. The possible relationship between glycosyltransferase release and TPA effect on the plasma membrane is discussed.

Cell Separation↗
PubMed1979

The specific release of sialytransferase activity by human hepatoma cell lines.

Sialyltransferase (EC 2.4.99.1) is released in large amounts by two hepatoma cell lines (SK-H-MA and CLH) established from patients with hepatocellular carcinoma (hepatoma). This release requires protein synthesis and glycoprotein synthesis, but not cell division. In contrast, sialyltransferase is released in minimal amounts by a cell line derived from normal human liver (Chang). The hepatoma cells also contain more surface and cellular sialyltransferase activity than Change cells. Hepatoma sialyltransferase has properties similar to other sialyltransferases. Using a calibrated Sephadex G-200 column, it is resolved into two forms with molecular weights of 65 000 and 80 000.

Carcinoma, Hepatocellular↗
PubMed1977

The clinical and physiological implications of hepatoma B12-binding proteins.

A serum B12-binding protein with increased sialic acid content (termed hepatoma B12-binding protein) that causes elevations of serum B12 and unsaturated B12-binding capacity has been found in some patients with hepatocellular carcinoma (hepatoma). We now report another patient with hepatoma with initial near-normal, unsaturated B12-binding capacity that increased 400-fold as the disease progressed and then fell 50% with response to chemotherapy. A perfusate of the tumor in the liver had 5 times more B12-binding protein than did the serum and was immunologically the same as the serum hepatoma B12-binding protein isolated from previous cases. A cell line derived from hepatoma produced significant amounts of B12-binding protein similar to hepatoma B12-binding protein, whereas cell lines from normal liver and other neoplasia did not. The hepatoma sera, perfusate, and media from the hepatoma cell line contained elevated sialyltransferase activity. These data suggest that some hepatomas produce increased hypersialylated B12-binding protein that is cleared slowly from the plasma and accumulates there as hepatoma B12-binding protein.

Adolescent↗