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Biomedical subjects

J T Lin

Publications and source records attributed to J T Lin.

At least 271 records · Page 15Linked to original sources
PubMed1979

Ethanediol monoester hydrolysis by monoacylglycerol lipase of rat liver microsomes.

The hydrolysis of long-chain monoester of ethanediol by rat,liver subcellular fractions was investigated in order to define the carboxylic acid ester hydrolase involved and to localize the enzymic activity. We found that with 1-O-hexadecanoyl [U-14C]ethanediol as substrate, hydrolytic activity was foremost associated with the rough microsomal fraction. The pH optimum occurred at 8.5. The apparent Km and V values were 6.5 . 10(-4) M and 13 mumol/h per mg microsomal protein, respectively. Enzymic activity was inhibited by p-chloromercuribenzoate and by diisopropylfluorophosphate, whereas NaF was less effective and CaCl2 did not affect apparent activity. Amongst a number of carboxylic acid esters tested as substrate, only long-chain 1-acyl and 2-acyl glycerols inhibited acyl diol hydrolysis competitively (Ki approximately 0.9 mM). It was concluded that long-chain monoesters of ethanediol are hydrolyzed by the monoacyl glycerol lipase system associated with the rat liver microsomal fraction. Because diol monoester is also utilized by the cholinephosphotransferase system of liver to form highly lytic acyl diol phosphocholines, efficient diol monoester hydrolysis by monoglyceride lipase may be a significant step in regulating acyl diol phosphocholine levels in biological systems.

Animals↗
PubMed1976

Psychiatric symptoms with initiation of carbidopa-levodopa treatment.

Two patients who had had no previous psychiatric symptoms became psychotic after their antiparkinsonism medication was changed from levodopa alone to a combination of levodopa and carbidopa, despite adherence to the appropriate and recommended dosage. Psychiatric symptoms disappeared after treatment with levodopa alone was resumed.

Aged↗
PubMed1975

Diol lipids of rat liver. Quantitation and structural characteristics of neutral lipids and phospholipids derived from ethanediol, propanediols, and butanediols.

Specific enzymatic and chemical degradation of neutral lipid and phospholipid fractions from rat liver revealed the presence of novel types of lipid metabolites bearing a short-chain diol backbone. Diol-derived lecithin and cephalin analogs were readily cleaved by phospholipase C (EC 3.1.4.3) from Bacillus cereus, although the cephalin analogs required "carrier" lecithin to sustain hydrolysis. The products of phosphilipase hydrolyses as well as the neutral lipid fractions were subjected to alkaline and acidic methanolysis, and constituent short-chain diols were analyzed as long-chain cyclic acetals. Gas chromatographymass spectrometry confirmed that 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, and 1,3 butanediol can form the polyol backbone of neutral lipids and phospholipids. [1,1,2,2-2H]Ethanediol monohexadecanoate, dihexadecanoate, hexadecanoylphosphorylcholine, hexadecanoylphosphorylethanolamine were synthesized chemically and served as internal standards to assure accurate quantitation of the low levels of diol lipids (350 mug/g ot total lipid) present in rat liver.

Animals↗
PubMedDate not supplied

Gray-scale and color Doppler sonographic diagnosis of epiploic appendagitis.

Depending on its location, epiploic appendagitis may mimic nearly any acute abdominal condition. We present the case of a patient with left lower quadrant pain. Sonography demonstrated an ovoid, hyperechoic, noncompressible lesion at the point of tenderness but no inflammatory changes in the adjacent colonic wall. Color Doppler sonography showed no flow in the lesion. Based on the sonographic diagnosis of epiploic appendagitis, conservative treatment was given, with complete recovery in 5 days. Awareness of these sonographic findings may aid in the early diagnosis of epiploic appendagitis and avoid unnecessary treatment.

Abdominal Pain↗
PubMedDate not supplied

Obstructive jaundice caused by hepatocellular carcinoma: detection by endoscopic sonography.

Tumor thrombus in the extrahepatic biliary tree is a rare mechanism of obstructive jaundice. We present a patient with a minute hepatocellular carcinoma in the caudate lobe that invaded the common hepatic duct and caused biliary obstruction. Endoscopic sonography showed a tumor thrombus with central echogenicity and a "nodule-in-nodule" pattern and suggested the correct diagnosis.

Aged↗
PubMedDate not supplied

Development of a potent bombesin receptor antagonist with prolonged in vivo inhibitory activity on bombesin-stimulated amylase and protein release in the rat.

Of the various types of potent bombesin(Bn)/gastrin releasing peptide receptor antagonists that have been discovered, the desMet14-methyl ester peptides are devoid of residual agonist activity and are among the most potent in terms of in vitro receptor blockade and also in terms of their prolonged inhibition of bombesin-stimulated amylase and protein release in the rat. We have now examined the in vitro and in vivo properties of a new series of methyl ester analogues, [D-Phe6]Bn(6-13)OMe, [D-Phe6,D-Ala11]Bn(6-13)OMe, N alpha-propionyl-[D-Ala24]GRP(20-26)OMe, and [D-pentafluoro-Phe6,D-Ala11]Bn(6-13)OMe, which have an additional D-amino acid substituent and some highly lipophilic moieties at the N-terminus. All analogues were able to potently antagonize the ability of Bn to stimulate amylase release from rat acinar cells, with IC50 values of 2.4, 2.5, 0.6, and 1.3 nM, respectively. The four peptides were found to have binding affinities for these cells comparable to Bn itself, with K(i)s of 10.3, 2.8, 5.5, and 3.6 nM, respectively, but all had little or no affinity for neuromedin B receptors on murine C6 cells. Single bolus IV injections of these peptides were found to potently inhibit amylase and protein release caused by IV infusion of bombesin into the rat. Generally the peptides containing the D-Ala substituent were longer acting than [D-Phe6]Bn(6-13)OMe, so that [D-Phe6,D-Ala11]Bn(6-13)OMe and N alpha-propionyl-[D-Ala24]GRP(20-26)OMe displayed significant inhibitory effects for up to 1.5 h after administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMedDate not supplied

Clinicopathologic study of 208 patients with early gastric cancer in Taiwan: a comparison between Eastern and Western countries.

To investigate whether there are any differences between the clinicopathologic characteristics of early gastric cancer (EGC) patients in Eastern and Western countries, 208 Taiwanese patients with EGC were reviewed between 1964 and 1992. The incidence of cancer has increased slightly over the 29-year period. Men were diagnosed with EGC frequently than women, and their mean age was 56 years. Epigastralgia (58.2%) was the most common symptom, whereas 5.8% of cancers were incidentally detected by endoscopy. Physical signs and laboratory tests were of limited value in making the diagnosis. Endoscopy was a better diagnostic aid than radiology. Tumours were frequently located in the lower third (53.2%) and middle third (43.3%) of the stomach. Cancers of the elevated type (17.8%) were less frequent than the depressed type (82.2%). Type IIc (31.2%) was the most common macroscopic type. 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 5-year survival rate was 90.8%. The clinicopathologic characteristics of EGC in Taiwan were similar to those of Western countries and other Eastern countries. Improvement of diagnostic examinations and endoscopic surveillance of asymptomatic subjects may lead to early diagnosis and thus ensure a more favourable outcome.

Europe↗
PubMedDate not supplied

Serum pepsinogen I and pepsinogen II, and the ratio of pepsinogen I/pepsinogen II in peptic ulcer diseases: with special emphasis on the influence of the location of the ulcer crater.

To investigate the effect of the location of the ulcer crater on the serum levels of pepsinogen I (PGI), pepsinogen II (PGII) and the ratio of PGI/PGII, these parameters were determined in 161 healthy controls, 29 patients with gastric ulcer in the gastric body (GU-I), 65 with coexistent gastroduodenal ulcer (GU-II), 104 with gastric ulcer in the prepyloric region (GU-III), and 116 with duodenal ulcer (DU). Serum PGI levels were significantly higher (P < 0.01) in patients with GU-III (110.6 +/- 65.1 ng/mL), GU-II (100.0 +/- 46.6 ng/mL), and DU (92.2 +/- 35.2 ng/mL) than in the controls (77.4 +/- 31.4 ng/mL), while there were no significant differences between GU-I (82.5 +/- 36.3 ng/mL) and the controls. Patients with gastric ulcer in any region had significantly higher (P < 0.01) serum PGII levels (GU-I, 20.0 +/- 15.7 ng/mL; GU-II, 15.5 +/- 10.9 ng/mL; GU-III, 14.3 +/- 10.0 ng/mL) than the controls (10.6 +/- 6.0 ng/mL) and the patients with DU (10.0 +/- 5.5 ng/mL), whereas no significant differences existed between the latter two. The ratio of PGI/PGII in GU-I (5.86 +/- 3.90) was significantly lower (P < 0.01) than any other group (controls, 8.83 +/- 4.70; GU-II, 8.33 +/- 4.99; GU-III; 9.64 +/- 6.13; DU, 10.45 +/- 4.49), while patients with DU it was significantly higher (P < 0.01) than any other groups. These findings indicate that peptic ulcer is comprised of a heterogeneous group of diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Effect of hepatitis C antibody screening in blood donors on post-transfusion hepatitis in Taiwan.

A national screening programme for antibody to hepatitis C virus (HCV) in blood donors in Taiwan began in July 1992 using a second-generation immunoassay. To study the impact of this screening on post-transfusion hepatitis in Taiwan, a prospective study on post-transfusion hepatitis, that was started in 1987, was continued. As of June 1994, 245 patients who received a blood transfusion after July 1992 had completed a follow-up period for more than 6 months post-transfusion. Of them, seven (2.8%) recipients developed acute post-transfusion hepatitis. The hepatitis in six cases could not be attributed to infection by hepatitis A, B, C, D, E viruses or cytomegalovirus (CMV) or Epstein-Barr virus (EBV). The remaining patient seroconverted to both IgG and IgM anti-CMV. All seven patients recovered in 6 months without development of chronicity, and the mean peak alanine aminotransferase level was lower compared with that of the cases before anti-HCV screening (i.e. pre-July 1992). These results indicate that the current anti-HCV screening has effectively interrupted HCV transmission through blood transfusion in Taiwan.

Adult↗
PubMedDate not supplied

Weekly 24-hour infusion of high-dose 5-fluorouracil and leucovorin in the treatment of advanced gastric cancers. An effective and low-toxic regimen for patients with poor general condition.

Systemic chemotherapy for advanced gastric cancer is frequently associated with significant treatment-related toxicity, which is particularly serve in patients presenting with a poor general condition. A search for effective and low-toxic regimens for this group of patients is mandatory. A weekly 24-hour infusion of high-dose 5-fluorouracil (5-FU) and leucovorin (HDFL) has previously been demonstrated to be an effective treatment for advanced colorectal cancer with minimal toxicity. In the past 3 years, this regimen has been tested at our institutes in patients with advanced gastric cancer, the general condition of whom had made the use of intensive combination chemotherapy impossible. The regimen consisted of a weekly 24-hour infusion of 2,600 mg/m2 of 5-FU and 300 mg/m2 of leucovorin. From August 1992 to December 1995, 34 patients had been treated with this regimen for a total of 488 courses (average: 14.4 per patient). Hematological toxicity of this regimen was minimal, with grade 3 or 4 leukopenia developing in only 1 (2.9%) patient. Other nonhematological toxicities were also negligible except a reversible neurotoxicity which developed in 2 patients. Twenty-five patients were eligible for response analysis. One complete response, 11 partial responses, 5 stable diseases, and 8 progressive diseases were observed. The response rate was 48% (32-72%, 95% CI). The median overall survival (OS) of the whole group was 7 months (range: 1-18+). The median OS and time to progression of the responders were 8.5 months (range: 2-18) and 5 months (range: 2-10+), respectively. The palliative effect was satisfactory with the Karnofsky performance status of the responders improving from a median of 50% (range: 20-90%) to 70% (range: 50-100%). Our retrospective data suggested that HDFL is an effective and low-toxic palliative treatment even in patients with a very poor general condition. We advocated that this regimen should be further tested in ordinary patients with advanced gastric cancer.

Adult↗