PubMed Health⌕ Search

Biomedical subjects

J T Lin

Publications and source records attributed to J T Lin.

At least 55 records · Page 3Linked to original sources
PubMed2000

Low frequency of bacteremia after endoscopic mucosal resection.

BACKGROUND: Endoscopic mucosal resection has become a popular alternative for the treatment of early-stage neoplasia of the gastrointestinal tract. However, there are still no data on the frequency of bacteremia associated with this form of treatment. METHODS: We conducted a prospective study of 21 men and 17 women undergoing endoscopic mucosal resection with a cap-fitted panendoscope for upper gastrointestinal lesions. Blood cultures were performed before, 10 minutes after, and 4 hours after the procedure for both aerobic and anaerobic bacteria. RESULTS: Blood culture at baseline was negative in all the patients. Two of 38 patients (5.3 %) had positive blood culture at 10 minutes after the procedure. The isolated microorganisms were Streptococcus salivarius and Corynebacterium species. All patients had negative blood cultures 4 hours later. None of these 38 patients had any symptoms or signs associated with infection. CONCLUSIONS: Bacteremia associated with endoscopic mucosal resection is infrequent and transient.

Adult↗
PubMed2000

Urgent endoscopic nasobiliary drainage without fluoroscopic guidance: A useful treatment for critically ill patients with biliary obstruction.

BACKGROUND: Endoscopic nasobiliary drainage (ENBD) is routinely performed under fluoroscopic control. This is a report of our experience with urgent ENBD without fluoroscopic guidance in critically ill patients. METHODS: Twenty-six critically ill patients who underwent urgent ENBD for biliary obstruction were analyzed. ENBD was performed without fluoroscopic control because of high risk of transportation or inaccessibility of the x-ray facilities. A pig-tailed nasobiliary catheter was inserted into the bile duct with the help of a guidewire under endoscopic control to bypass the site of obstruction. Successful placement was confirmed by free flow of bile on aspiration via the nasobiliary catheter. RESULTS: A nasobiliary catheter was successfully placed in 23 patients (88%). Adequate bile drainage was achieved in 20 patients with an overall success rate of 77%. There were no procedure-related complications. The mortality rate for patients with successful biliary drainage was 10% (2 of 20), in contrast to 83% (5 of 6) for the group in which drainage was unsuccessful. CONCLUSIONS: Urgent ENBD is effective for patients with biliary obstruction. With experience, this procedure may be successfully performed in critically ill patients without fluoroscopic guidance at primary care hospitals or intensive care units where fluoroscopic facilities are not readily available.

Adult↗
PubMed2000

The shrinkage-activated Na(+) conductance of rat hepatocytes and its possible correlation to rENaC.

At moderate cell shrinkage, activation of Na(+) channels is the most prominent mechanism of regulatory cell volume increase in rat hepatocytes. The amiloride sensitivity of these channels suggests a relation to the family of epithelial Na(+) channels (ENaCs). The present study was performed to determine the pharmacological profile of shrinkage-activated Na(+) channels and to test for ENaC expression in primary cultures of rat hepatocytes; in addition, the influence of the cell volume regulated serine/threonine kinase hSGK on activity and pharmacological profile of rENaC was examined in Xenopus oocytes. Conventional electrophysiology in hepatocytes reveals that the shrinkage-activated Na(+) channel is inhibited by amiloride and EIPA with IC(50) values of 6.0 and 0.12 micromol/l, respectively. Western blots and RT-PCR demonstrate that rat hepatocytes do express all three subunits (alpha, beta, gamma) of ENaC. Coexpression of hSGK with rENaC in Xenopus oocytes reveals that the kinase stimulates ENaC by a factor of 4. Moreover, hSGK decreases the affinity to amiloride (increase of IC(50) from 0.12 to 0.26 micromol/l) and increases the affinity to EIPA (decrease of IC(50) from 250 to 50 micromol/l). In conclusion, rat hepatocytes express ENaC, which is activated by the cell volume-sensitive kinase hSGK. ENaC may contribute to the Na(+) channels activated by osmotic cell shrinkage in hepatocytes, whereby the relatively low amiloride and high EIPA sensitivity of the channel could at least be partially due to modification by SGK, which decreases the amiloride and increases the EIPA sensitivity of ENaC.

Amiloride↗
PubMed2000

Associations of plasma aflatoxin B1-albumin adduct level with plasma selenium level and genetic polymorphisms of glutathione S-transferase M1 and T1.

Mortality from hepatocellular carcinoma (HCC) is extraordinarily high in Matzu, an island off the coast of Southeastern China. To investigate factors associated with plasma aflatoxin B1 (AFB1)-albumin adduct level, we studied 304 healthy adult residents from Matzu. AFB1-albumin adducts were determined by competitive enzyme-linked immunosorbent assay, hepatitis B surface antigen status by enzyme immunoassay, genotypes of glutathione S-transferase (GST) M1 and T1 by polymerase chain reaction, plasma selenium by atomic absorption spectrometry, and plasma retinol, alpha-tocopherol, alpha-carotene, and beta-carotene levels by high-performance liquid chromatography. Men had higher AFB1-albumin adduct levels than women. GSTM1-nonnull and GSTT1-null genotypes and low plasma selenium level were significantly associated with an increased level of AFB1-albumin adducts among men, whereas age was significantly correlated with adduct level among women. High intake of fermented beans was associated with an increased adduct level among men and women. The inverse associations between plasma selenium level and AFB1-albumin adducts were statistically significant among those with null genotypes of GSTM1 and GSTT1, but not among the nonnull genotypes. This study provides insight into the dietary and genetic factors influencing AFB1-albumin adduct formation in an isolated population with high liver cancer mortality.

Adult↗
PubMed2000

Punctate midline myelotomy for the relief of visceral cancer pain.

OBJECT: This study offers clinical support for the concept that neurosurgical interruption of a midline posterior column pathway by performing a punctate midline myelotomy (PMM) provides significant pain relief without causing adverse neurological sequelae in cancer patients with visceral pain refractory to other therapies. METHODS: A PMM of the posterior columns was performed in six cancer patients in whom visceral pain had been refractory to other therapies. The cause of the visceral pain was related to residual, progressive, or recurrent local cancer or postirradiation effects. Clinical efficacy of the procedure was examined by comparing patient pain ratings and narcotic usage pre- and post-PMM. Follow-up periods ranged from 3 to 31 months. Examination of the results indicates a significant reduction in pain ratings as well as a significant reduction in daily narcotic use. No adverse neurological effects were observed. One spinal cord has been recovered for postmortem examination. CONCLUSIONS: These findings provide corroborating clinical evidence for the existence of a newly recognized midline posterior column pathway that mediates the perception of visceral pelvic and abdominal pain. Preliminary data indicate that significant pain relief can be obtained following PMM with minimal neurological morbidity and suggest that the procedure may provide an alternative treatment modality for cancer-related pain in patients in whom adequate pain control with narcotics cannot be achieved or narcotic side effects cannot be tolerated.

Abdominal Neoplasms↗
PubMed2000

Distinct clinicopathologic and genetic profiles in sporadic gastric cancer with different mutator phenotypes.

A subset of sporadic gastric cancers (GC) exhibits microsatellite instability (MSI). To define the precise role of MSI in GC, a total of 100 patients with sporadic GC were classified into three groups, i.e., high-frequency MSI (MSI-H), low-frequency MSI (MSI-L), and microsatellite stable (MSS), based on 10 microsatellite markers. Mutational analyses of TGFbetaRII, IGFIIR, BAX, MSH3, MSH6, E2F4, MSH2, MLH1, and TP53 genes, and methylation and protein expression of MLH1 and MSH2 were performed and correlated. Twenty-seven percent of GC showed MSI at least in one locus and could be further graded as MSI-H (14%) and MSI-L (13%). No clinicopathologic difference was noted between GC with MSI-L and MSS. Compared with GC with MSI-L or MSS, GC with MSI-H had a significantly higher frequency of antral location, intestinal subtype, H. pylori seropositivity, but a lower incidence of lymph node metastasis, and displayed a higher frequency of frameshift mutations of TGFbetaRII, IGFIIR, BAX, MSH3, and E2F4 genes but a lower incidence of TP53 mutations. Furthermore, hypermethylation of the MLH1 promoter was responsible for the loss of protein function in 13 of 14 MSI-H tumors. It was concluded that a specific phenotype and a distinct profile of genetic alterations exist in MSI-H GC. We speculate that epigenetic inactivation of MLH1 by methylation plays a crucial role in initiating such a pathway of carcinogenesis. In contrast, GCs with MSS and MSI-L exhibit clinicopathologic features that are distinct from MSI-H tumors and have a higher frequency of TP53 mutations, suggesting that they may evolve through an entirely different pathway.

Adaptor Proteins, Signal Transducing↗
PubMed2000

The development of algorithms in electrical impedance computerized tomography.

Electrical Impedance Computerized Tomography (EICT) is an imaging method to reconstruct the impedance distribution inside of domain through the boundary injected current and display the impedance contrast ratio as an image. This paper concentrates on developing two algorithms to enhance the quality of the conductivity image. The two algorithms are "Fine-Mesh Conversion Method" and "Sub-Domain EICT Method". "Fine-Mesh Conversion Method" is a numerical calibration process to find a coarse mesh impedance network that behaves like a fine mesh network in terms of giving similar voltages under the same current excitations. "Sub-Domain EICT" solves a higher resolution EICT with the cost of a lower resolution EICT by combining "Fine-Mesh Conversion Method", and a Fuzzy Logic Inference Systems (FLIS) classifier.

Algorithms↗
PubMed2000

Accurate diagnosis of Helicobacter pylori infection by stool antigen test and 6 other currently available tests in children.

Invasive and noninvasive tests have been developed for the diagnosis of Helicobacter pylori infection. Because H pylori infection is acquired in childhood and adolescence, accurate diagnosis of the infection in the pediatric population is important. We conducted a study to compare invasive tests: culture, biopsy urease test, histology, and polymerase chain reaction on gastric biopsy specimens, with noninvasive tests: serology, (13)C-urea breath test, and a new diagnostic modality, stool antigen test to diagnose H pylori infection. A total of 53 children with symptoms were enrolled in this study, and all had completed the 7 diagnostic tests for H pylori. All the diagnostic tests except serology were excellent methods of diagnosing H pylori infection in children; the diagnostic accuracy was as follows: stool antigen test 96.2%, biopsy urease test 96.2%, histology 98.1%, polymerase chain reaction 94.3%, culture 98.1%, (13)C-urea breath test 100%, and serology 84.9%. The stool antigen test, being highly sensitive and specific, will be potentially very helpful in diagnosing H pylori infection in children.

Adolescent↗
PubMed2000

Cellular uptake of dietary flavonoid quercetin 4'-beta-glucoside by sodium-dependent glucose transporter SGLT1.

Although it has been suggested that the intestinal glucose transporter may actively absorb dietary flavonoid glucosides, there is a lack of direct evidence for their transport by this system. In fact, our previous studies with the human Caco-2 cell model of intestinal absorption demonstrated that a major dietary flavonoid, quercetin 4'-beta-glucoside, is effluxed by apically expressed multidrug resistance-associated protein-2, potentially masking evidence for active absorption. The objective of this study was to test the hypothesis that quercetin 4'-beta-glucoside is a substrate for the intestinal sodium-dependent D-glucose cotransporter SGLT1. Cellular uptake of quercetin 4'-beta-glucoside was examined with Caco-2 cells and SGLT1 stably transfected Chinese hamster ovary cells (G6D3 cells). Although quercetin 4'-beta-glucoside is not absorbed across Caco-2 cell monolayers, examination of the cells by indirect fluorescent microscopy as well as by HPLC analysis of cellular content revealed cellular accumulation of this glucoside after apical loading. Consistent with previous observations, the accumulation of quercetin 4'-beta-glucoside in both Caco-2 and G6D3 cells was markedly enhanced in the presence of multidrug resistance-associated protein inhibition. Uptake of quercetin 4'-beta-glucoside was greater in SGLT1-transfected cells than in parental Chinese hamster ovary cells. Uptake of the glucoside by Caco-2 and G6D3 cells was sodium-dependent and was inhibited by the monovalent ionophore nystatin. In both Caco-2 and G6D3 cells, quercetin 4'-beta-glucoside uptake was inhibited by 30 mM glucose and 0.5 mM phloridzin. These results demonstrate for the first time that quercetin 4'-beta-glucoside is transported by SGLT1 across the apical membrane of enterocytes.

Animals↗
PubMed2000

Abdominal wall necrosis following transcatheter arterial chemoembolization for hepatocellular carcinoma.

A 76-year-old man, who had inoperable hepatocellular carcinoma, had been treated with transcatheter arterial chemoembolization (TACE) 11 times, percutaneous ethanol injection therapy three times and conformal radiotherapy once, all in other hospitals. At this admission, he developed myocutaneous necrosis in the right abdominal wall after TACE, via the collateral of the right internal mammary artery (IMA). Necrosis of the abdominal wall was due to ischemic changes caused by embolization of the distal branches of the IMA, which were aggravated by previous radiation therapy. We advise that embolization of the IMA in patients who have received radiotherapy should be avoided, if possible.

Abdominal Muscles↗
PubMed2000

Biochemical aspects of castor oil biosynthesis.

Castor oil is 90% ricinoleate (12-hydroxy-oleate) and has numerous industrial uses. Components of castor bean (Ricinus communis L.) pose serious problems to processors. We are evaluating two complementary approaches to providing a safe source of castor oil.

Acyl Coenzyme A↗
PubMed1999

Preoperative sonographic diagnosis of midgut malrotation with volvulus in adults: the "whirlpool" sign.

Midgut malrotation and volvulus, found mostly in children, are rare and difficult to diagnose preoperatively in adults. We report 2 cases in which a 68-year-old man and a 75-year-old woman presented with intermittent cramping abdominal pain, abdominal distention, and vomiting. Abdominal sonography demonstrated wrapping of the superior mesenteric vein and bowel loops around the superior mesenteric artery (the "whirlpool sign") in both patients. Abdominal CT revealed similar findings. The diagnoses of midgut volvulus and mesenteric malrotation were made, and the patients underwent laparotomy. The man was confirmed to have duodenojejunal malrotation and volvulus, and the woman had cecal volvulus. The whirlpool sign is valuable for the preoperative diagnosis of mesenteric vessel malrotation and midgut volvulus.

Aged↗
PubMed1999

Sonographic "gastric corona sign": diagnosis of gastric pneumatosis caused by a penetrating gastric ulcer.

We present a case of gastric pneumatosis associated with splenoportal venous gas caused by a giant penetrating gastric ulcer. On sonography, the gastric pneumatosis appeared as a circular hyperechoic band with distal reverberations due to gas collection in the gastric wall; we termed this appearance the "gastric corona sign. "Awareness of this sonographic sign may aid in the early diagnosis of gastric pneumatosis.

Aged↗
PubMed1999

Biosynthesis of ricinoleate in castor oil.

Castor oil is 90% ricinoleate (12-hydroxyoleate) and has numerous industrial uses. Components of castor bean (Ricinus communis L.) pose serious problems to processors. Other researchers have cloned the gene for the oleoyl hydroxylase, but transgenic plants produce only about 20% hydroxy fatty acid. To improve such transgenic substitutes for castor, we are using HPLC analysis of castor bean microsomal suspensions to follow the hydroxylase reaction and the movement of 14C-ricinoleate through phospholipid into triacylglycerol. Most labeled ricinoleate is rapidly removed from the phospholipid fraction as free fatty acid and incorporated into triacylglycerol, with triricinolein predominating. Elucidation of the basis for high incorporation of ricinoleate and exclusion of oleate from triacylglycerols will identify genes that can be used to engineer high ricinoleate production in transgenic plants.

Castor Oil↗
PubMed1999

Characterization of Neurospora crassa mutants isolated following repeat-induced point mutation of the beta subunit of fatty acid synthase.

Neurospora crassa cel-2 mutants were isolated following repeat-induced point mutation using part of the gene encoding beta-fatty acid synthase. These mutants are phenotypically less leaky than cel-1, which has a defective alpha-fatty acid synthase. The cel-2 mutant had a strict fatty acid (16:0) requirement for growth, and synthesized less fatty acid de novo than cel-1. Unlike cel-1, cel-2 has impaired fertility, and homozygous crosses are infertile, suggesting a low but strict requirement for fatty acid synthesis during sexual development. Like cel-1, cel-2 synthesized unusually high levels of the polyunsaturate 18:3(Delta9,12,15), and elongated 18:2(Delta9,12 )and 18:3(Delta9,12,15 )to 20:2(Delta11,14) and 20:3(Delta11,14,17), respectively. These fatty acids are not synthesized by wild-type, except following treatment with cerulenin (a fatty acid synthase inhibitor), demonstrating that inhibition of fatty acid biosynthesis results in a relative increase in both fatty acid desaturation and elongation activity.

Alleles↗
PubMed1999

Isolation of a Helicobacter pylori protein, FldA, associated with mucosa-associated lymphoid tissue lymphoma of the stomach.

BACKGROUND & AIMS: The growth of gastric mucosa-associated lymphoid tissue lymphoma (MALToma) seems to depend on the stimulation of Helicobacter pylori. We attempted to identify specific antigen(s) from H. pylori strains associated with MALToma. METHODS: Membranous and secreted proteins of H. pylori were compared on sodium dodecyl sulfate-polyacrylamide gel electrophoresis by Western blot using sera from patients with MALToma. RESULTS: A 19-kilodalton protein was seen in all strains isolated from patients with MALToma but uncommonly in other strains. The protein was purified and sequenced. Amino acid sequence comparison showed it was an FldA homologue, a putative flavodoxin protein. DNA sequencing in 26 strains revealed that a nucleotide G insertion at position 481 of the fldA gene was more frequently observed in strains associated with MALToma than other strains (9/9 vs. 6/17; P = 0.002). The mutation caused a short truncation. A recombinant protein with this truncation was expressed and tested. Sera of 12 (70.6%) of 17 patients with MALToma were positive for the antibody to the recombinant protein, and 7 (16.7%) of 42 control patients were positive (12/17 vs. 7/42; P < 0.0001). CONCLUSIONS: Truncated FldA of H. pylori is associated with gastric MALToma. It may be involved in the pathogenesis of gastric MALToma. Antibody to this antigen could be used as a serological marker of the disease.

Adult↗