Search PubMed⌕ Search

Biomedical subjects

K Li

Publications and source records attributed to K Li.

At least 415 records · Page 23Linked to original sources
PubMed1986

Asynchronous left ventricular wall motion early after coronary thrombosis.

To study regional wall motion early in the development of acute myocardial infarction, left ventriculograms performed in 24 patients before thrombolysis and within 3.5(1.2) (mean (SD] hours of the onset of pain were digitised frame by frame. Isometric and contour plots of regional wall motion were constructed. In 19 patients (seven with anterior descending, eight with right, and four with circumflex disease) thrombosis was demonstrated on an underlying stenosis. In 10 patients the two remaining coronary arteries were normal, and in nine, one or both showed important disease. Mean values of global indices of left ventricular function, including end diastolic volume, ejection fraction, peak ejection and filling rates, and cavity shape changes were all within normal limits, though end systolic volume was significantly raised. Total systolic amplitude of wall motion was normal in the affected area in all but seven patients (four with anterior descending, two with right, and one with circumflex thrombosis). Dyskinesis of more than 2 mm was seen in only three patients, all with thrombosis of the anterior anterior descending coronary artery, and hyperkinesis was present in four. The commonest abnormality of wall motion was hypokinesis during ejection followed by prolonged inward motion during isovolumic relaxation, which was seen in four patients with anterior descending, seven with right, and three with circumflex artery thrombosis. This was preceded by outward motion during isovolumic contraction and delayed inward motion during ejection in eight with right or circumflex thrombosis. Five of six patients without thrombosis had simple hypokinesis or dyskinesis without asynchrony. Disease of other coronary arteries did not affect the pattern of wall motion seen after right or circumflex coronary artery occlusion but it reduced the incidence of delayed inward motion along the free wall after thrombosis of anterior descending artery. Thus early after acute coronary thrombosis asynchronous wall motion is commoner than simple hypokinesis or dyskinesis. Its persistence suggests that in the setting of coronary artery thrombosis in man, residual contractile activity may persist for up to six hours after the onset of symptoms.

Acute Disease↗
PubMed1986

Changes in left ventricular regional asynchrony after intracoronary thrombolysis in patients with impending myocardial infarction.

Ventriculograms obtained before and a mean (SD) of 4.3 (2.5) weeks after intracoronary thrombolysis in 23 patients who were treated within 3.5 (3.1) hours of the onset of pain were examined for changes in asynchronous left ventricular wall motion. Lysis was achieved in 19 patients, and in 16 the affected artery was still patent at restudy. Angiograms were digitised frame by frame. Left ventricular volumes, ejection fraction, and peak ejection rate were all unchanged after thrombolysis, whereas peak filling rate fell, whether or not patency was achieved or maintained. Regional wall motion was examined by means of isometric and contour plots. The area supplied by the affected coronary artery showed simple hypokinesis or akinesis in 10 cases, which was unchanged at the second study in nine and improved in one. The commonest manifestation of asynchrony was delayed inward motion during isovolumic relaxation. This was present in 12 cases with or without associated hypokinesis; after thrombolysis wall motion improved significantly in eight and returned to normal in six, significantly more frequently than it did in patients with simple hypokinesis. Dyskinesis (three patients) and hyperkinesis (five patients) resolved in all. Outward wall motion during isovolumic relaxation reverted to normal in four out of five cases, and outward motion during isovolumic contraction reverted to normal in five out of seven. The frequency of improvement was also increased when the circulation to the affected segment was not compromised by an important residual stenosis. Flow in the affected artery was re-established or maintained significantly less frequently when simple hypokinesis or akinesis was present at the first study. These observations provide further evidence that asynchronous wall motion early after acute myocardial infarction represents residual contractile activity, and suggest that knowledge of its presence and distribution may be useful in assessing patients on whom thrombolysis is performed.

Coronary Angiography↗
PubMed1986

Anatomical correction for complete transposition and double outlet right ventricle: intermediate assessment of functional results.

Thirty three patients were followed up after anatomical correction of transposition of the great arteries or double outlet right ventricle and subpulmonary ventricular septal defect (Taussig-Bing anomaly). There were no late deaths and clinical progress was excellent. Cardiac catheterisation was performed in 17 patients two weeks to 44 months after operation. There were six patients with simple transposition, six with complete transposition and large ventricular septal defect, and five with the Taussig-Bing anomaly. Pressure gradients across the right ventricular outflow tract ranged from 5 to 72 mm Hg, being greater than 40 mm Hg in five patients. No patient was shown to have important valvar regurgitation and in 15 patients the coronary anastomoses were widely patent. Left ventricular function was assessed from digitised ventriculograms. Ventricular volume, shape, and ejection fraction were all normal for the group although patients with complex transposition showed a significantly lower mean (SD) ejection fraction than those with simple transposition (62(9) vs 77(9]. Analysis of regional wall motion showed a totally normal pattern in four patients; however, in seven patients a characteristic abnormality of anterior hypokinesis with delayed onset of inward wall motion was seen. Anatomical correction of transposition of the great arteries and the Taussig-Bing anomaly can be performed with satisfactory anatomical and functional results. The implications of the left ventricular wall motion abnormalities is unknown.

Angiography↗
PubMed1985

Establishment of a model of transplantable myelocytic leukemia (L801) in LACA mice.

A transplantable myelocytic leukemia model of LACA mice, designated by the name of L801, was established by intravenous injection of spleen cell suspension from mice with radiation-induced myelocytic leukemia into mice of the same strain. Until now, for more than three years, the L801 has maintained stable and rapid growth and has been reproduced for over 130 serial passages. The incidence of leukemia in inoculated animals was approximately 100% and mean survival time was 10.9 +/- 2.1 days. The L801 is of myelocytic type which has been determined by cytological, cytochemical, pathological and ultrastructural observations. Its karyotype was hypodiploid, characterized by modal number of 39, loss of Y chromosome and an abnormal huge marker chromosome. The cell cycle duration of the L801 was 16 h. C-type viral particles were observed under the electron-microscope. The L801 was sensitive, to varying extents, to various anti-tumor agents. We presume that the L801 is a useful tool in studies on mechanism of leukemogenesis, anti-tumor agent screening and treatment of experimental tumors.

Animals↗
PubMed1984

[Chemotherapy of advanced genitourinary carcinoma with cis-diamminedichloroplatinum].

Eighteen patients with advanced genitourinary carcinoma have been treated with cis-diamminedichloroplatinum (CDDP) since 1978, at our University Hospital. They were 3 patients with prostatic cancer, 3 patients with bladder cancer, 6 patients with testicular tumors, 5 patients with renal cell carcinoma and 1 patient with malignant pheochromocytoma. Four patients with testicular tumors were administrated CDDP, bleomycin (BLM) and vinblastine (VBL). A testicular tumor patient was given CDDP, vincristine and actinomycin-D, a bladder cancer patient was given CDDP, VBL and Pepleomycin as combined chemotherapy. The remaining 12 patients were treated only with CDDP. Five of the 6 patients with testicular tumor and a case of choriocarcinoma of left kidney showed an objective response. As side effects, bone marrow suppression was inevitable when VBL and BLM were given along with CDDP. Renal dysfunction was seen in 5 patients on whom BVP regimen was employed. Various degrees of nausea and vomiting were present in almost all patients during CDDP administration. The combination chemotherapy with CDDP appears to be effective in nonseminomatous testicular tumor. The effectiveness of CDDP against other genitourinary carcinomas may require further investigation.

Adolescent↗
PubMed1984

Microdosimetry and thermoluminescence.

The mechanism for production of light from a thermoluminescent phosphor requires the combination of a trapped electron and hole at a luminescent center. The kinetics is that of a second-order process. Accordingly one may expect a similarity in the formalism for describing thermoluminescent emission (TL) and the theory of dual radiation action in radiobiology (TDRA). The TDRA was developed to provide a framework for describing the effects of ionizing radiation on biological systems. It requires the interaction of two primary units of radiation damage called "sublesions" to form a "lesion" which may then be expressed as a biological effect. The physical parameters used in the TDRA come from microdosimetry, which deals with the deposition of energy by ionizing radiation in domains whose dimensions are of the order of micrometers. This paper explores the relationships between microdosimetric concepts and a description of TL properties, such as TL dose-response curves and TL LET dependence. This is then compared with similar quantities in biology to determine the possible relevance of TL as a biological model.

Cell Survival↗
PubMed1983

[Non-epitherial malignant neoplasms of the breast--a clinicopathological study of 4 cases].

Between 1972 and 1981, 4 women with breast sarcoma underwent treatment at our department; they accounted for 1.1% (4 of 355) of all female breast malignancies. There was one case of malignant lymphoma and liposarcoma each, and 2 cases of malignant cystosarcoma phyllodes. The patients averaged 31.0 years of age. Of the two cases of cystosarcoma phyllodes, one had coexisting lobular carcinoma in situ arising in a fibroadenoma of the contralateral breast, the other had a coexisting lung cancer. Mastectomy was performed in 3 cases, irradiation in one (malignant lymphoma). All patients received concurrent chemotherapy. The regional lymph nodes were not involved, and 2 patients are alive and well without recurrence.

Adolescent↗
PubMed1980

Effect of hormone manipulation on oxidation, reduction and sulphurylation of dehydroepiandrosterone and oestrone in DMBA-induced rat mammary tumours.

Using the DMBA-induced mammary tumour as a model, the effect of hormone manipulation on steroid sulphurylation and on oxidative and reductive metabolism has been investigated. Oestradiol-17 beta, or oestradiol-17 beta + progesterone, administered to oophorectomized animals, had no effect on adenosine-3'-phosphate-5'-phosphosulphate formation in the tumours. Dehydroepiandrosterone sulphotransferase was also unaffected. A large increase in oestrogen sulphotransferase following administration of oestrogen + progesterone was observed in some but not all tumours, and the overall results were not statically significant. The major metabolities of dehydroepiandrosterone, by both human and carcinogen-induced rat mammary tumours in vitro, are 7-oxygenated derivatives. Oestrogen administration led to a significantly decreased production of total 7-oxygenated derivatives of dehydroepiandrosterone. Conversion to 5-androstene-3 beta, 17 beta-diol was unaffected by the hormones. The rate of formation of oestradiol-17 beta from oestrone was increased 5-fold in growing tumours from animals receiving oestrogen, or oestrogen + progesterone, compared to regressing tumours in oophorectomized control animals.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1979

Estimation of kinetic parameters of neutrophilic, eosinophilic, and basophilic granulocytes in human blood.

Two hematologically normal patients with glioblastoma and six patients with chronic lymphocytic leukemia received continuous 3H-thymidine infusions for 3--10 days. In autoradiographs of blood cell smears taken for 25 days or more after the beginning of 3H-thymidine administration the labeling index and the labeling intensity of granulocytes were determined. A sufficiently high labeling intensity, i.e. a sufficiently long autoradiographic exposure time was found to be critical for obtaining valid and reproducible results. On the basis of certain assumptions discussed in detail, complete labeling of cells with 3H-thymidine followed by autoradiographic evaluation and mathematical analysis of the labeling patterns seems to be a suitable method for estimation of kinetic parameters of postmitotic granulocytes in vivo. The mean intramedullary maturation and storage time was observed to be 115 +/- 7 h or neutrophils, 103 +/- 4 h for eosinophils and 103 +/- 11 h for basophils. The mean relative inflow rate into the blood (or relative turnover rate in the blood) was found to be 4.2 +/- 0.4/h for neutrophils, 4.0 +/- 0.4%/h for eosinophils and 1.2 +/- 0.3%/h for basophils. The mean blood transit time (or blood sojourn time) was estimated to be 25 +/- 2 h or neutrophils, 26 +/- 3 h for eosinophils and 89 +/- 21 h for basophils. Accordingly the half lifes (T 1/2) of granulocytes in the blood were 17.3 +/- 1.4 h for neutrophils, 18.0 +/- 2.1 for eosinophils and 62 +/- 15 h for basophils. Under the quasi steady state conditions of this study the kinetics of granulocytes in the present CLL patients appeared to be normal, despite a marked lymphocytic infiltration of the bone marrow. The apparent discrepancy between these findings and the data obtained with autotransfusion of DFP-labeled granulocytes is discussed.

Aged↗
PubMed1978

Products of dehydroepiandrosterone metabolism by human mammary tumors and their influence on estradiol receptor binding.

The high concentrations of dehydroepiandrosterone and its 3beta-sulfate in the blood are potential preocursors for further metabolism by normal and tumorous human mammary tissue. In vitro metabolism of 7n-3H- and 1,2,6,7(n)-3H-dehydroepiandrosterone by fifteen mammary tumors was examined. Some 10--50% of the radioactivity recovered was in the form of 7-oxygenated derivatives: the major metabolite being 7alpha-hydroxydehydroepiandrosterone accompanied by lesser amounts of the 7beta-epimer. 5-Androstene-3beta,17beta-diol was formed in all but one case. Evidence showed that the high yield of 7alpha-hydroxy derivative resulted from direct action of a 7alpha-hydroxylase capable of using both dehydroepiandrosterone and 5-androstene-3beta,17beta-diol as substrates. Although 5-androstene-3beta,17beta-diol competed with estradiol-17beta for the estrogen receptor, this property was considerably reduced as a consequence of the introduction of a 7alpha-hydroxyl or 16alpha-hydroxyl group. Dehydroepiandrosterone, which competed less effectively for the estrogen receptor site, showed almost no affinity for the site upon the introduction of a 7alhpa-hydrocyl group. A regulatory role for the 7alpha-hydroxylase is outlined.

Androstenediols↗