Biomedical subjects

Y F Liu

Publications and source records attributed to Y F Liu.

At least 91 records · Page 5Linked to original sources

PubMed1991

Ferritin in astrocytomas.

Ferritin in 119 astrocytoma cases was studied by immunocytochemical PAP and immunogold silver staining (IGSS) methods. In 57% of the cases, ferritin was found in the cytoplasm of the tumor cells. The higher the differentiation of the tumor cells, the less ferritin they contained. Contrary to the reaction of glial fibrillary acidic protein (GFAP), the positive rate of ferritin in various types and grades of astrocytomas was inversely proportional to their degree of differentiation. Electron microscopic observation in 30 cases showed ferritin in the cell sap, cytocavity network, endoplasmic reticulum, Golgi apparatus and also in lysosomes. Some of the cases had extraordinary high level of ferritin in their blood serum.

Astrocytoma↗

PubMed1991

A twelve month double-blind randomized study of the efficacy and immunogenicity of human and porcine insulins in non-insulin-dependent diabetics.

This study aims to compare the effectiveness and immunogenicity of semisynthetic human insulin (NOVO) and highly purified (monocomponent) porcine insulin over a 12 month period in 16 non-insulin-dependent diabetic subjects not previously exposed to insulin. Sixteen patients were randomly allocated for treatment with either human (n = 9) or monocomponent porcine (n = 7) insulin in a double-blind trial. Both groups were identical with respect to age, sex and measures of metabolic control. Significant insulin antibody was detected in seven of the nine patients (78%) 3 months after the commencement of human insulin therapy whereas it was detected in all patients (100%) in the group treated with monocomponent porcine insulin as early as 2 months after insulin therapy. Besides the delayed rise of insulin antibodies during the first 3 months of human insulin therapy, it tended to have a lower mean insulin antibody titer, though statistically insignificant, at the end of the study. No adverse reaction to either type of insulins was noted. It is concluded that both semisynthetic human and monocomponent porcine insulin were safe and effective. Although human insulin showed a slightly lower immunogenicity than monocomponent porcine insulin of the same formulation and purities, it was not non-immunogenic. Hence, there is no reason to treat all insulin-requiring diabetic subjects with human insulin except those who have developed insulin allergy or those at risk or with a history of allergy.

Adult↗

PubMed1991

Radioimmunolocalization of human malignant tumors with In-111 labeled monoclonal antibody.

An anti-human colon carcinoma monoclonal antibody 2C10 was radiolabeled with In-111 and studied in 15 patients with gastrointestinal and ovarian carcinoma. The labelling efficiency approached 100% and immunoactivity of the labeled antibody was over 75%. 2-3 mCi (1 mg) In-111-2C10 was given to the patients intravenously and scintigraphy was performed 72 hours after administration with a gamma camera. Specimens were also scanned in some of the patients. The resected tumors and remote margin were examined immunohistochemically. Positive scintigraphic images were obtained in 12/15 patients with colorectal cancer (10) and ovarian cancer (2). Negative results were seen in the two patients with gastric cancer. The scintigraphic results of 10 patients were confirmed surgically and pathologically. The remaining 5 were confirmed by endoscopy, B-ultrasonography or X-ray CT. Most patients had been definitely diagnosed before imaging except one patient with metastatic focus from ovarian cancer to colon and one with recurrent colon cancer were first detected with RIAD, showing the unique advantage the latfer. The high background radioactivity in the liver, however, is a conspicuous problem to be solved.

Adult↗

PubMed1991

[Effect of herbal prostatitis decoction on experimental prostatitis in rats].

Herbal prostatitis decoction is a great effective prescription to treat chronic prostatitis in promoting the blood circulation and relieving the stasis. The authors had succeeded in making rats experimental fibrous proliferation type prostatitis models by using xiaozhiling injection method. Rats were divided into two groups: the decoction-given group (DG) and the water-given group (WG). Microscopically, both inflammatory cell infiltration and fibroblast proliferation of interstitial tissue in the DG were slight than the WG (P less than 0.025, P less than 0.05). Transmission electron microscopic observations showed both the secretary particles and metal-granule-like substances (including Zn) of the gland cells in the DG were obviously increased. The lysosomes in the cytoplasm were increased also. The results performed a certain experimental basis for the functional mechanism of the herbal prostatitis decoction treatment.

Animals↗

PubMed1990

Insulin insensitivity in offspring of parents with type 2 diabetes mellitus.

Measurements were made of the plasma glucose and insulin responses to a 75 g oral glucose challenge in 50 Chinese born in Taiwan, divided into two groups on the basis of family history of Type 2 diabetes. Twenty-five individuals (age 29 +/- 5 (+/- SD) years) had 2 parents with normal oral glucose tolerance, whereas at least 1 parent had Type 2 diabetes in the other 25 subjects (age 30 +/- 6 years). In addition, in vivo insulin action was estimated by determining the steady-state plasma glucose concentration during a 3-h continuous infusion of glucose, insulin, and somatostatin. Steady-state plasma glucose concentration was used as a measure of insulin-induced glucose disposal. The 50 subjects were non-obese, and of comparable gender distribution and body mass index. Plasma glucose and insulin concentrations in response to oral glucose were similar in the two groups. However, the steady-state plasma glucose concentration was significantly (p less than 0.01) higher in offspring with a family history of Type 2 diabetes when compared by two-way analysis of variance (mean +/- SE was 5.87 +/- 0.27 vs 5.12 +/- 0.32 mmol l-1). This difference was found despite a significantly (p less than 0.01) higher steady-state plasma insulin concentration during the infusion studies (0.705 +/- 0.027 vs 0.643 +/- 0.025 nmol l-1) in offspring of people with diabetes. The results support the view that resistance to insulin-stimulated glucose uptake is present in offspring of diabetic parents.

Adult↗

PubMed1990

An in vitro approach to the kinetics of insulin antibodies in diabetic patients.

The purpose of this study is to evaluate the binding behavior of plasma insulin antibodies (Iab) in diabetic patients, by the following parameters: Incubation time, temperature, buffer pH, and Iab titer. We investigated the plasma insulin binding patterns of 12 insulin-treated diabetic patients, and they were separated as higher titer group (Iab = 51.9 +/- 7.28, n = 6) and lower titer group (Iab = 14.88 +/- 4.75, n = 6). The procedure was: (1) plasma samples were deinsulinized by 0.12N HCL, dextran coated charcoal suspension and 0.12N NaOH. (2) I-125 monoiodoinsulin was used to prevent artifacts resulting from variability in ligand binding due to excessive iodination, (3) separation of free and bound insulin was accomplished by rapid precipitation of hormone-antibody complex with polyethylene glycol, and (4) decanting the supernatants and counting the pellets in the automatic gamma counter. The data were obtained as the condition of incubation time, temperature, buffer pH, and Iab titer. The results obtained by the Scatchard analysis indicated that high temperature (39 degrees C vs 37 degrees C) in vitro would increase the free insulin levels and decrease the low affinity binding capacity (Q2-Q1) of Iab in patients with high titer of Iab (greater than 40%), whereas this phenomenon is not observed in patients with low affinity binding sites of Iab in patients with low titers of insulin antibodies (less than 20%).

Antigen-Antibody Reactions↗

PubMed1989

An immunocytochemical study on the distribution of ferritin and other markers in 36 cases of malignant histiocytosis.

The distribution of ferritin in 36 autopsy cases of malignant histiocytosis was investigated by immunocytochemical staining, together with the detection of alpha 1-antichymotrypsin, alpha 1-antitrypsin, lysozyme, S-100 protein, and ricinus communis agglutinin in the consecutive sections. The results showed that ferritin-positive tumor cells were present in every case. The quantity of cellular ferritin in well-differentiated histiocytes was higher than that in atypical histiocytes. Double labeling showed that ferritin and alpha 1-antichymotrypsin might be located either in one tumor cell or in separate cells. Our data suggest that ferritin may be a tumor associated antigen in malignant histiocytosis, playing a regulatory role for tumor cell differentiation.

Adult↗

PubMed1989

Evidence for the presence of disulfide bridges in opioid receptors essential for ligand binding. Possible role in receptor activation.

The mobility of purified mu opioid binding protein in SDS-polyacrylamide gek electrophoresis is sensitive to the presence of reducing agents. In the presence of increasing concentrations of DTT the apparent molecular weight increases in a stepwise fashion from 53 kDa to 65 kDa. This reduction in mobility is attributed to the successive breakage of disulfide bridges, resulting in an increasingly asymmetric molecule. Treatment of cell membranes from various brain areas with reducing agents, such as DTT, produced a concentration-dependent inhibition of opioid binding. Sensitivity to DTT inhibition varied between receptor types, mu greater than delta much greater than kappa. For mu receptors, agonist binding was considerably more sensitive to DTT than antagonist binding. Inhibition by DTT is readily reversible and is unaffected by Na+ and/or Mg2+ ions. Reversibility may be partially prevented by the inclusion of a low concentration of a reducing reagent such as glutathione which does not inhibit binding but blocks reformation of disulfide bonds. Scatchard analysis of saturation data shows that DTT causes a pronounced decrease in binding affinity with little effect on receptor number. It is suggested that disulfide bonds are essential for ligand binding and that cleavage of one or more of these bonds may play a role in opioid receptor activation by agonists.

Animals↗

PubMed1989

The effect of intrauterine devices (stainless steel ring, copper-T220 and levonorgestrel) on the DNA content in isolated human endometrial cells.

The effect of three different intrauterine devices on the DNA content in human endometrial cells has been studied in 29 women before and after the insertion of an IUD; a stainless steel ring (9 subjects), Copper-T220 (11 subjects) and a medicated IUD releasing levonorgestrel at a rate of 2 micrograms/day (9 subjects). The material was grouped into "bleeders" (having more than 8 days of bleeding and spotting per month) and "non-bleeders" (having less than 8 days of bleeding and spotting per month). The DNA content was assessed on isolated endometrial cells smeared from thin biopsies and the amount of DNA per cell nucleus was measured by means of a Feulgen microspectrophotometric method. No significant difference was found between the "bleeders" and the "non-bleeders" as to the DNA content. Nevertheless, when the total number of subjects were pooled together, a significant increase in the DNA content was found in the post-insertion specimens in the groups of women using the SS and the T-Cu IUDs. Furthermore, a significant decrease in the DNA content was also found when the specimens obtained after the insertion of the LNG IUD were compared with those obtained after 24 months' use of the stainless steel ring and the Copper-T220 device (p less than 0.01 and p less than 0.002, respectively). It is concluded that the insertion of an inert IUD or an T-Cu IUD, induces significant alterations in the DNA content of the human endometrium adjacent to the device, whereas the use of the LNG device does not significantly modify the DNA synthesis when used for 3-10 months. No correlation was found between the DNA content per cell and the number of days of bleeding and spotting.

Adult↗

PubMed1989

[Assessment of endoscopic embolization in the management of esophageal varices].

Between February 1984 and September 1987, endoscopic embolization (EE) was performed in 26 patients with esophageal varices. The effects of EE were evaluated with endoscopic findings according to the general rules for recording endoscopic findings on esophageal varices as specified by the Japanese Research Society for Portal Hypertension. 1) When the result was regarded as effective if a patient had Cw, F1, R-C sign (-), Li and Lm or disappearance of varices, the improvement was found in 66.7% for Color, 79.2% for R-C sign, 54.2% for Form and 45.8% for Location after EE. 2) Recurrence of varices was found in 50% of the patients (12/24) and 4 of 12 cases (33.3%) had rebleeding. 3) When the endoscopic findings before and after EE were compared between relapsed and unrelapsed cases, relapsed patients had more unfavorable endoscopic findings, furthermore, the extent of improvements was also worse than that of unrelapsed cases. 4) As complications, slight fever, dysphagia and epigastric pain were found in most cases, however, all were cured conservatively. In conclusion, EE is useful and safety tool for the improvement of endoscopic findings of the patients with esophageal varices.

Adult↗

PubMed1989

The content and composition of immunoreactive somatostatin in monkey pancreas.

A highly sensitive and specific radioimmunoassay (RIA) was developed for analyzing somatostatin (SRIF-LI). The monkey pancreas was lyophilized and extracted with 2N acetic acid. The content and composition of immunoreactive somatostatin in monkey pancreas were then evaluated by chromatography process and RIA. The concentration of SRIF-LI in monkey pancreas was around 513.8 ng/g dry weight. At least 3 components of SRIF-LI were detected in pancreatic extracts. The major component of SRIF-LI (about 92%) was SS-14, and other two were SS-28 and a form bigger than SS-28.

Animals↗

PubMed1989

[The primary and secondary pathological changes in the brain in patients with epidemic hemorrhagic fever].

Pathological changes of brain in 12 patients died of epidemic hemorrhagic fever were analysed. Those cases having clinical history of hypotension and typical shock showed ischemic changes and necrosis of brain and its seguelae accompanying synchronous with infarct-like necrosis of the kidneys or pituitary gland (secondary change). One patient who died in the febrile stage showed scattered necrosis of nerve cells with neuronophagia (primary change). Immunocytochemical study on one recent case showed diffusely distributed positive virus antigen in neurons and glial cells of various kinds and even occasional positive reaction was seen in the nuclei.

Adult↗

PubMed1989

[Cloning and expression of tryptophan synthetase gene (TRP5) in yeast].

TRP5, one of five genes required for tryptophan synthetase in S. cerevisiae, has been isolated on recombinant plasmids. A genomic DNA bank, containing the entire yeast genome was constructed by complete digestion of yeast 1412-4D DNA with restriction endonuclease BamH1, size fractionated by sucrose gradient (2-4 kb), and insertion of the fragments into the yeast shuttle vector pCN60. 9 recombinants plasmids capable of complementing trp5 mutations were isolated by transformation of yeast cell C9 (alpha, trp5, adel, ade6). The recombinant plasmids, containing 3.2 kb DNA fragments located TRP5 gene, were named pCN60 (TRP5). Tryptophan synthetase activity of transformants was 3-fold higher than that of original strain 1412-4D.

Cloning, Molecular↗

PubMed1989

Immunogenicity of highly purified porcine and human insulins in diabetic patients with high titers of insulin antibody.

Twenty-nine non-insulin-dependent diabetic Chinese subjects previously treated with conventional porcine isophane insulin (NPH) for a period of time, whose titer of serum insulin antibody was greater than 40% were changed to either highly purified pork insulin (Nordisk, Denmark) or human insulin of recombinant DNA origin (Eli Lilly, USA) for 1 year in a double-blind and randomized trial. The human (n = 16) and pork insulin (n = 13) groups were carefully matched for age, sex and measures of metabolic control. In highly purified pork-insulin-treated patients, the glycated hemoglobin and fasting blood sugar values began to fall significantly from a mean of 13.2% to 12.3% (p less than 0.05) and 228 mg/dl to 183 mg/dl (p less than 0.005), respectively, 2 months after the commencement of this study, whereas insulin antibody levels began to fall significantly from a mean of 61.8% to 49.5% (p less than 0.01) 6 months after the start of the study. Also, daily insulin doses increased significantly from a mean of 58 units to 70 units (p less than 0.005) 6 months after the start of the study. In human-insulin-treated patients, there were no significant changes in the glycated hemoglobin values. The fasting blood sugar levels fell significantly (p = 0.0515) at the end of the study period but the insulin antibody levels did not show any significant change during the same study period. Daily insulin dose increased significantly from a mean of 51 units to 57 units (p less than 0.01) 4 months after beginning the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1988