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Biomedical subjects

C Y Yang

Publications and source records attributed to C Y Yang.

324 records · Page 18Linked to original sources

White count, pH and lactate in ascites in the diagnosis of spontaneous bacterial peritonitis.

In order to evaluate the diagnostic accuracy of ascitic pH and lactate for early confirmation of spontaneous bacterial peritonitis (SBP), 109 consecutive patients with ascites were studied. The mean ascitic leukocyte [white blood cell (WBC)] and polymorphonuclear cell (PMN) counts, pH and lactate levels in 42 patients with sterile "normal" ascites were 124 +/- 157 per mm3, 41 +/- 77 per mm3, 7.502 +/- 0.097 and 11.1 +/- 7.9 mg per dl, respectively. Mean ascitic WBC and PMN counts were significantly increased in 10 patients with SBP (10,452 +/- 8,091 and 9,522 +/- 7,470 per mm3), in 10 patients with bloody ascites (2,591 +/- 4,284 and 1,057 +/- 1,494 per mm3) and in 11 patients with cytology positive malignant ascites (1,529 +/- 2,071 and 868 +/- 1,601 per mm3) (p less than 0.001). Mean ascitic pH was significantly reduced in SBP (7.335 +/- 0.048), in bloody ascites (7.384 +/- 0.037) and in cytology positive malignant ascites (7.355 +/- 0.167) (p less than 0.001). Mean ascitic lactate was also significantly elevated in these three groups of patients (36.8 +/- 17.0, 42.8 +/- 35.8 and 24.0 +/- 17.5 mg per dl, respectively; p less than 0.001) as well as in patients with bacteremia (51.6 +/- 78.0 mg per dl, p less than 0.005). However, ascitic pH less than 7.31, ascitic lactate greater than 33 mg per dl were observed only in three of the patients with SBP.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascitic Fluid↗

The real-time ultrasonography of pancreatic pseudocyst: comparison of infected and noninfected pseudocysts.

The real-time ultrasonograms of 15 patients with pancreatic pseudocysts (10 infected and 5 noninfected) were analyzed to evaluate difference in ultrasound characteristics between the infected and noninfected pseudocysts. Only those who underwent ultrasound-guided aspiration or operation within one week after sonography were reviewed according to the size, multiplicity, air content, internal echoes, and wall characteristics (such as thickness, regularity, and calcification) of pseudocysts. Among these ultrasonographic features of pseudocysts, there was no statistically significant difference between the infected and noninfected pseudocysts in cyst size, wall characteristics (thickness, regularity, and calcification), multiplicity, and air content. The most important and unique feature was the internal echoes within the pseudocyst. The internal echoes were classified into three grades. All the infected pseudocysts and one noninfected pseudocysts had internal echoes of grade 1. The difference is statistically significant (p = 0.0037). These results indicate that grading internal echogenicity of the pseudocysts with real-time ultrasonographies can add additional information important in differentiating infected from noninfected pseudocysts.

Abscess↗

Appearance and persistence of hepatitis A IgM antibody in acute clinical hepatitis A observed in an outbreak.

143 patients with acute hepatitis A observed during a common source outbreak were tested for IgM class antibody to hepatitis A virus (IgM anti-HAV) by commercially available solid phase radioimmunoassays. All patients were IgM anti-HAV positive though six of them were initially negative when tested within three days after the onset of symptoms. The levels of IgM anti-HAV peaked two to four weeks after onset, and declined gradually thereafter. The probability of IgM anti-HAV positivity was 25% at the end of the sixth month, and 3.4% at the end of the ninth month after onset. No significant sex or age difference in the persistence of IgM anti-HAV was observed. It was suggested that the timing of the assay and the level of IgM anti-HAV should be considered in the etiological diagnosis of acute hepatitis.

Adolescent↗

Parathyroid hormone and parathyroid hormone related protein assays in the investigation of hypercalcemic patients in hospital in a Chinese population.

There are many pathological causes and potential mechanisms for hypercalcemia. We measured intact parathyroid hormone (PTH) and parathyroid hormone related protein (PTHrP) in the hypercalcemic in-patients and attempted to evaluate the roles of PTH and PTHrP in hypercalcemia due to malignancy. We performed a prospective study of 178 patients with corrected serum calcium concentrations greater than 2.74 mmol/l in a hospital over a 3-year period. We measured calcium and albumin using a Hitachi 747 autoanalyzer, and we measured PTH and PTHrP by two-site immunoradiometric assays (IRMA). Hypercalcemia was attributed to malignancy alone in 93 patients (52.3%), primary hyperparathyroidism (HPT) alone in 28 patients (15.7%), uremia with hemodialysis in 23 patients (12.9%), unknown in 16 patients (9%), primary HPT coexisting with malignancy in 7 patients (3.9%) and other rare causes (6.2%). Plasma PTHrP levels were elevated in 71/93 (76.3%) patients with hypercalcemia due to malignancy, but the elevated PTHrP percentage differed for each kind of tumor. PTHrP levels were elevated in 100% of patients with squamous carcinomas (CA) in the lung, esophagus, skin, cholangiocarcinoma of liver, and breast CA. The positive bony metastatic rate was 44.1% (41/93). There was no correlation between high PTHrP and bony metastasis. There was a good correlation between the corrected serum calcium and PTHrP levels (r = 0.476, p < 0.001), but no correlation between survival time and serum calcium level or PTHrP level. There was no significant difference in life expectancy after cancer diagnosis between the high PTHrP group and normal PTHrP group, and there was no significant difference in life expectancy after the first occurrence of hypercalcemia between the two groups. Measurement of both PTH and PTHrP levels led to a change in the initial diagnosis in 7 patients. In routine practice, measurement of serum PTH alone is not enough. This study suggests that the appropriate combination of PTH and PTHrP assays results in a more accurate diagnosis of the hypercalcemic causes. In addition, especially high PTHrP levels should be screened for malignancy. However, the prognosis in cancer patients after hypercalcemia with high PTHrP group, as compared to those with the normal PTHrP group is not significantly different.

Adult↗

Glutamate-, GABA-, and GAD-immunoreactivities co-localize in bipolar cells of tiger salamander retina.

The presence of inhibitory bipolar cells in salamander retina was investigated by a comparative analysis of the distribution of glutamate- and GABA-immunoreactivities (GLU-IR; GABA-IR) using a postembedding immunocytochemical method. GLU-IR was found in virtually all photoreceptors, bipolar cells and ganglion cells, neuronal elements that transfer information vertically through the retina. GLU-IR also was found in numerous amacrine cells in the mid and proximal inner nuclear layer as well as in the cytoplasm of horizontal cells, while the nucleus of horizontal cells was either lightly labeled or not labeled at all. GLU-IR was found in the outer plexiform layer and intensely in the inner plexiform layer, in which there was no apparent sublamination. Forty-seven percent of Type IB bipolar cells in the distal inner nuclear layer and 13% of the displaced bipolar cells were GABA-IR. All bipolar cells were also GLU-IR, indicating that GABA-IR bipolar cells were a subset of GLU-IR bipolar cells rather than a separate population. About 12% of the Type IB bipolar cells were moderately GABA-IR and likely comprised a GABAergic subtype. GLU-IR levels in the presumed GABAergic bipolar cells were higher than in other purely GLU-IR bipolar cells suggesting that these GABA-IR bipolar cells are glutamatergic as well. All of the displaced bipolar cells were only lightly GABA-IR, indicating that displaced bipolar cells comprise a more homogeneous class of glutamatergic cell than orthotopic bipolar cells. GAD-IR co-localized with GABA-IR in orthotopic but not displaced bipolar cells, further supporting the idea that some orthotopic bipolar cells are GABAergic. A small proportion of bipolar cells in salamander retina contain relatively high levels of both GABA and glutamate. Co-release of these substances by bipolar cells could contribute to the "push-pull" modulation of ganglion cell responses.

Animals↗

Field studies on 32P movement and P leaching from flooded paddy soils in the region of Taihu Lake, China.

Field experiments were done in two sites, Yixing and Changshu, Jiangsu province, China, to study P movement and leaching in flooded paddy soils. P movement in soil was investigated by using the KH2 32PO4 tracker method, and the amount of P leached from the soil layer in different depths was estimated by measuring P concentrations in the soil solution and saturated hydraulic conductivities in field. Determination was done about one month after P application. There was 46% and 42% of total 32P retained in the 0-5cm layer of soil in the Yixing site and in the Changshu site respectively. The 32P retained in the 25-30 cm layer was only about 1-2% of the total 32P added. Furthermore, 8.01% of 32P in the soil of Yixing site and 16.8% of 32P in the soil of Changshu site was lost from the layer 0-30 cm soil. The seasonal amounts of P leached from the top soil layer and from bottom layer are about 4.5-5.8% and 1.6-2.1% of the total P application, respectively. Changes of total P concentrations in soil solutions during rice growth showed that the fertilizer P applied before flooding of the paddy fields suffered a flash leaching loss and a slow leaching loss. We concluded that the fertilizer P could quickly move in the flooded paddy rice field and parts of it can enter into surface water and ground water. Unless the P application is well managed the risk of P loss and consequently environmental pollution exist.

Agriculture↗

Sequence, structure, receptor-binding domains and internal repeats of human apolipoprotein B-100.

Apolipoprotein (apo) B-100, the major protein component in low density lipoprotein (LDL), is the ligand that binds to the LDL receptor. It is important in the metabolism of LDL and elevated plasma levels of LDL-apo B are strongly associated with increased risk of coronary artery disease. Although apo B-100 is of great clinical and biological importance its primary structure has defied chemical elucidation, mainly because of its enormous size, insolubility, and tendency to aggregate. Less than 5% of the apo B-100 sequence has been reported, despite the efforts of many laboratories over the past twenty years. Here we report the complete amino acid sequence of human apo B-100 as deducted by sequence analysis of complementary DNA clones; 2,366 of the 4,536 residues were also confirmed by direct sequencing of apo B-100 tryptic peptides. The distribution of trypsin-accessible and -inaccessible peptides of the protein on LDL is non-random and they can be grouped into 5 hypothetical domains. Of 20 potential N-glycosylation sites identified in the sequence, 13 were found by direct peptide sequencing to be glycosylated, and 4 unglycosylated. Examination of the primary structure of apo B-100 reveals that it contains a large number of long (greater than 70 residues) internal repeats and an even larger number of shorter ones, suggesting that the apo B-100 sequence was derived largely from internal duplications. Finally, using synthetic peptides of a specific region of apo B-100, we have identified a potential LDL receptor-binding domain (residues 3,345-3,381) which can bind to the LDL receptor and suppress 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase activities in cultured human fibroblasts.

Amino Acid Sequence↗

Female lung cancer and petrochemical air pollution in Taiwan.

To investigate the relationship between petrochemical air pollution and female lung cancer, we conducted a matched case-control study among women who had died in Taiwan from 1990 through 1994. Data about all eligible female lung cancer deaths were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. The control group included women who died from nonneoplasms and diseases that were not associated with respiratory problems. We pair-matched the controls to the cases by sex, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each case. We used the proportion of a municipality's total population employed in the petrochemical manufacturing industry as an indicator of a resident's exposure to air emissions from the petrochemical manufacturing industry. The subjects were divided into tertiles according to the above indicator. Women who lived in the 2 groups of municipalities characterized by higher levels of petrochemical pollution had a statistically significant higher risk of developing lung cancer than the group that lived in municipalities with the lowest petrochemical air pollution levels (after controlling for possible confounders). The linear trend was also statistically significant (p < .05). The results of this study shed important light on the relationship between the Taiwan petrochemical industry and the resulting risk to human health.

Age Factors↗

An enhanced process for encapsulating aspirin in ethyl cellulose microcapsules by solvent evaporation in an O/W emulsion.

An enhanced process for microencapsulating aspirin in ethylcellulose was demonstrated using an oil-in-water emulsification/solvent evaporation technique. Methylene chloride (CH2Cl2) was used as the dispersed medium and water as the dispersing medium. The recovered weight, particle size distribution, aspirin loading efficiency, and the aspirin release rate of microcapsules were analysed. The addition of appropriate amounts of non-solvent (n-heptane) prior to the emulsification increases the recovered weight, but decreases the size of the formed microcapsules. The addition of non-solvent also changes the microcapsule characteristics, resulting in a coarser surface and an increased release rate. Increasing the polymer (ethylcellulose) concentration in the dispersed phase increases the size of the microcapsules, the recovered weight, and loading efficiency, but decreases the release rate. The release rate follows first-order kinetics during the first 12 h, suggesting a monolithic system with aspirin uniformly distributed in the microcapsule.

Aspirin↗

Encapsulating aspirin into a surfactant-free ethyl cellulose microsphere using non-toxic solvents by emulsion solvent-evaporation technique.

Microencapsulation of aspirin in ethylcellulose was studied in a surfactant-free, water-in-oil type of emulsification/solvent evaporation process using non-toxic solvents. Ethanol was used as the dispersed phase and soybean oil as the continuous phase. The recovered weight, particle size distribution, aspirin loading efficiency, and the aspirin release rate of microspheres were analysed. The addition of a small amount of non-solvent (water) prior to the emulsification was found to have a significant impact on the microencapsulation process. Adding non-solvent increases the recovered weight and the size of the microspheres. The addition of non-solvent also markedly changes the microsphere characteristics, resulting in a coarser surface and an increased release rate. Increasing the emulsification evaporation temperature increases the size of the microsphere, but reduces the recovered weight and loading efficiency. The release rate follows a first-order kinetics and Higuchi matrix kinetics at low concentrations of non-solvent, suggesting a monolithic system with aspirin uniformly distributed in the microsphere.

Anti-Inflammatory Agents, Non-Steroidal↗

Interaction of low density lipoproteins with human aortic elastin.

Interaction between lipoproteins and elastin in the arterial wall may play an important role in atherosclerotic lipid deposition, but binding affinities and other characteristics of the interaction have not been determined previously. Elastin was isolated by hot alkali treatment of human aortic tissue. At 4 degrees C, radioiodinated human low density lipoprotein (LDL) bound to more than one class of binding sites on elastin. Sites of highest affinity had an apparent dissociation constant of 3.6 x 10(-8) M. Total binding at an LDL concentration of 50 micrograms/ml ranged from 4 to 50 ng LDL protein/mg elastin. The binding was relatively specific, since binding was competitively inhibited by LDL and apo E-containing high density lipoprotein (HDL) but only modestly by HDL3. Atherosclerotic elastin exhibited a twofold to fourfold higher capacity for binding LDL, but a reduced affinity. At 37 degrees C, normal elastin exhibited an initial rapid binding of LDL, with a slower linear phase of binding over a 15-hour period, indicating an additional complex process at this temperature. Consideration of the expected LDL concentrations in the arterial intima, in comparison with binding affinities, suggests that LDL binding to elastin probably occurs in the intima and may foster atherosclerotic lipid deposition.

Albumins↗

Structure of apolipoprotein B-100 of human low density lipoproteins.

We have analyzed low density lipoproteins (LDL) apolipoprotein (apop) B structure by direct sequence analysis of LDL apo B-100 tryptic peptides. Native LDL were digested with trypsin, and the products were fractionated on a Sephadex G-50 column. The partially digested apo B-100 still associated with lipids was recovered in the void volume (designated trypsin-nonreleasable, TN, peptides). The released peptides (designated trypsin-releasable, TR, peptides) in subsequent peaks were repurified on two successive high-performance liquid chromatography (HPLC) columns. The TN peak was delipidated and redigested with trypsin, and the resulting peptides were purified on two successive HPLC columns. Using this approach, we sequenced over 88% of LDL apo B-100, extending and refining our previous study (Nature 1986;323:738-742) which covered 52% of the protein. TN peptides made up 31%, and the TR peptides, 34% of the apo B-100 sequence; 23.7% were found under both TN and TR categories. Based on its differential trypsin releasability, apo B-100 can be divided into five domains: 1) residues 1----1000, largely TR; 2) residues 1001----1700, alternating TR and TN; 3) residues 1701----3070, largely TN; 4) residues 3071----4100, mainly TR and mixed; and 5) residues 4101----4536, almost exclusively TN. Domain 1 contained 14 of the 25 Cys residues in apo B. Domain 4 encompassed seven N-glycosylation sites, and contained the putative receptor binding domains. All 19 potential N-glycosylation sites were directly sequenced: 16 were found to be glycosylated and three were not. Three pairs of disulfide bridges were also mapped. Finally, a combination of cDNA sequencing, direct mRNA sequencing, and comparison of published apo B-100 sequences allowed us to identify specific amino acid residues within apo B-100 that seem to represent bona fide allelic variations. Our study provides information on LDL apo B-100 structure that will be important to our understanding of its conformation and metabolism.

Amino Acid Sequence↗

Newcastle disease virus isolated from recent outbreaks in Taiwan phylogenetically related to viruses (genotype VII) from recent outbreaks in western Europe.

Three major outbreaks of Newcastle disease (ND) occurred in Taiwan in the last three decades (in 1969, 1984, and 1995). Newcastle disease viruses (NDVs) isolated in the three outbreaks, together with those isolated in 1998, were sequenced between nucleotides 47 and 435 of the fusion gene. A phylogenetic tree based on sequences obtained showed that the NDV isolated in 1969 was similar to the genotype III viruses. In contrast, all isolates in 1984 and seven of the eight isolates in 1995, together with all isolates in 1998, fell into the genotype VII. These results suggest that the 1969 outbreak of ND in Taiwan was caused by the genotype III virus, whereas the 1984 and 1995 outbreaks were caused by the genotype VII viruses. To date, the genotype VII viruses have caused many outbreaks in east Asia and western Europe. We suspect that these outbreaks have constituted the fourth panzootic of ND, which is distinct from the third panzootic caused by the "pigeon PMV-1 viruses." NDV isolated in Taiwan in 1984 was the earliest isolation of the genotype VII virus.

Amino Acid Sequence↗

The effect of intragastric acidity on Helicobacter pylori eradication with bismuth-metronidazole-amoxicillin.

BACKGROUND/AIMS: Adding an acid secretion inhibitor to anti-H. pylori regimens may be potentially valuable for enhancing the effectiveness of antimicrobials that exhibit markedly reduced activity at low pH. This study was conducted to evaluate intragastric acidity as a factor in H. pylori eradication with bismuth-based triple therapy. METHODOLOGY: Forty patients with duodenal ulcer and H. pylori infection were included. The patients were divided into 2 groups--normacid (n = 20) and hyperacid (n = 20)--based on the amount of time that 24-hour intragastric pH took to reach the level pH > or = 3. All patients received bismuth subsalicylate (600 mg 3 times daily), metronidazole (500 mg 3 times daily) and amoxicillin (500 mg 3 times daily) for 2 weeks. Then, all patients continued treatment with ranitidine (150 mg twice daily) for 8 weeks prior to the follow-up examination. Blood samples were collected before treatment for measurement of fasting gastrin and pepsinogen-I. RESULTS: Nine patients (45%) in the normacid group and 8 patients (40%) in the hyperacid group reported side effects. However, there were only 2 patients (10%) in each group who withdrew from the study due to intolerance of side-effects. There was no difference in the H. pylori eradication rate between the normacid and hyperacid groups (16/18, 88.9% vs. 15/18, 83.3%). CONCLUSIONS: Without co-administration of anti-secretary agents, intragastric acid is not a significant factor in the effectiveness of H. pylori eradication with bismuth-based triple therapy.

Adult↗

The normal width of anterior hip synovial recess in children.

To establish the diagnostic criteria for hip joint effusion, the normal width of the anterior hip synovial recess in children and the difference between both hips of the same child were examined in this study. Eight kindergarten schools were randomly selected for study in Kaohsiung City. The width of anterior hip synovial recess of 1,568 hips in 784 children (421 boys, 363 girls) was measured by ultrasound scanner with 7.5-MHz linear probe. The age of children ranged from 2.5 to 6.6 years old. During measurement, the children were put in supine position with hips and knees in extension and patella facing up. The results revealed that the mean width of the anterior synovial recess was 7.29+/-1.15 mm. Linear correlation of the width of synovial recess to age and height was disclosed and expressed as follows: width (millimeters) equal to 6.52+0.013x age (months), or width (millimeters) equal to 3.97+0.030x height (centimeters). The mean difference between both hips of the same child was 0.611+/-0.523 mm, and the difference was independent from the factors of age, gender, height, or weight (p>0.05). Ninety-five percent of the differences should be < or =1.46 mm, so that if the difference between hips is >1.46 mm, hip joint effusion should be suspected.

Child↗

Nucleotide sequence and phylogenetic analysis of Newcastle disease virus isolates from recent outbreaks in Taiwan.

Portions of the hemagglutinin neuraminidase (HN) gene of Newcastle disease virus (NDV) isolates from two recent outbreaks were sequenced to investigate epidemiology of this disease in Taiwan. These NDV isolates were all viscerotropic velogenic according to the clinical lesions produced in chickens. Sequence data were obtained from 14 NDV isolates (12 from 1995 and 2 from 1984). All isolates differed in their nucleotide sequences (from 0.3 to 15.3%), and represented potentially different strains of NDV. Phylogenetic analysis revealed that these isolates are closely related to viruses isolated from Japan and Malaysia. Some viruses isolated in 1995 appeared to evolve from viruses isolated in 1984. The results suggest that the 1995 outbreak of Newcastle disease (ND) in Taiwan may have been caused by multiple strains of velogenic NDV that have cocirculated in Taiwan for some time. Moreover, NDV isolates from racing pigeons were very similar to isolates from chickens in the same period, suggesting that both domestic and free-living birds were involved in the spread of ND in Taiwan.

Amino Acid Sequence↗