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T W Chen

Publications and source records attributed to T W Chen.

17 recordsLinked to original sources
PubMed1994

Mucopolysaccharide histochemistry of the oviduct of the toad, Bufo melanostictus, before and during ovulation.

In both non-ovulating and ovulating toads of the species, Bufo melanostictus, the fimbrium stained only weakly for mucopolysaccharides (MPs) whereas the infundibulum stained strongly for neutral MPs and also for glycogen. In the non-ovulating toad, only neutral and sulphated MPs were detected in the goblet cells of the upper magnum, whereas sulphated, neutral and sialomucins were detected in the glands. In the middle magnum, sulphated and sialic acid-containing carboxylated MPs were detected in both the goblet cells and glands. In the lower magnum, neutral, sulphated, and sialic acid-containing MPs were detected in the goblet cells and only sulphated and sialic acid-containing MPs were detected in the glands. In the isthmus and ovisac, only sulphated MPs were present in the goblet cells. During ovulation, there was no change in the distribution of sulphated MPs throughout the oviduct. Sialic acid-containing MPs could not be detected in many of the goblet cells of the upper and lower magnum nor in most of the glands of the lower magnum.

Animals↗
PubMed1992

Spurious hyperchloremia and decreased anion gap in a patient with dextromethorphan bromide.

Although cold syrup containing dextromethorpan bromide is widely administered, the bromism due to cold syrup has not been reported. We report a patient who had negative anion gap with hyperchloremia and conscious loss because of daily intake of cold complex syrup (containing dextromethorphan bromide 0.4 mg/ml, acetaminophen 8.33 mg/ml) for headache for 4-5 years. The bromide content in cold complex syrup resulted in serum levels of bromide that interfered with the automated analyzers for chloride content. When conscious change is due to bromism, hemodialysis instead of forced hydration and diuresis should be performed immediately. Therefore, patients with a markedly negative anion gap with hyperchloremia should be considered as having halide intoxication.

Bromides↗
PubMed1992

Peritoneal clearances of carbon dioxide in the rat.

In our previous rat studies (Kidney Int. 1991; 39: 608-617) we evaluated peritoneal clearances (Cp) representing near exclusively diffusive CO2 transfer: for isosmotic (0.37% dextrose) and hyperosmotic (15% dextrose) solutions with pH 7.2-7.3, CpCO2 were 1.20 +/- 0.08 and 1.84 +/- 0.04 ml/min, respectively. In the present studies we have compared Cp of CO2 gas and HCO3- in anesthetized rats (n = 22) using solutions with dextrose contents as mentioned above but with pH 6.5 or 7.6; we have also evaluated how much Cp CO2 measurements obtained with solutions at these pH values differ from Cp shown earlier with the solutions of pH 7.2-7.3. Cp of CO2 gas and HCO3- were significantly higher under hyperosmotic than isosmotic conditions. The use of solutions of pH different from 7.2-7.3 resulted in higher Cp of CO2 gas: with isosmotic solutions of pH 6.5 and 7.6 mean increases were 25 and 75%, respectively; with hyperosmotic solutions respective increases were 45 and 134%. We conclude that dialysis solution osmolality and pH significantly change Cp of CO2 gas and HCO3- in the rat. For evaluation of peritoneal blood flow from diffusive transfer parameters of CO2 gas, smaller overestimation can be expected when dialysis solution pH is slightly under-than overadjusted compared to blood pH.

Animals↗
PubMed1992

A scanning and transmission electron microscopic study of the membranes of chicken egg.

Questions regarding the structure of the inner and outer shell membranes of the chicken egg were addressed in this study by correlating observations from light microscopy and scanning and transmission electron microscopy. The egg membrane had a limiting membrane, which measured .9 to .15 microns in thickness and appeared to be a continuous and an impervious layer, but the shell membrane did not. Under the SEM, each membrane was seen to be made up of several fibre layers. In the tear preparations viewed under the SEM two layers were observed in the egg membranes and three to five layers in the shell membrane, with an apparent plane of cleavage between each layer. Each fibre was made up of a central core and an outer mantle layers. The central core was perforated by channels which measured .08 to 1.11 microns in diameter and ran longitudinally along the length of the fibre. Between the mantle layer and the fibre core was a gap or cleft measuring between .03 to .07 microns. The diameter of the fibres of the inner layer of the egg membrane ranged between .08 to .64 microns, whereas those of the outer layer of the same membrane ranged from .05 to 1.11 microns. Fibres in the shell membrane ranged from .11 to 4.14 microns diameter.

Animals↗
PubMed1991

Ultrafiltration and effective peritoneal blood flow during peritoneal dialysis in the rat.

The dependence between maximum net ultrafiltration rate (nUFR) created by 15% dextrose dialysis solution and effective peritoneal capillary blood flow (EPBF) estimated by the diffusive mass transport coefficient (KBD) and peritoneal clearance (Cp) of CO2 gas was evaluated during 30 minute, 15 ml peritoneal dialysis exchanges in anesthetized rats (N = 18). The values of KBD for CO2 suggested a mean EPBF of 1.9 +/- 0.1 (SEM) ml/min for isosmotic exchanges and 2.7 +/- 0.2 ml/min for hyperosmotic ones with a mean maximum nUFR of 0.43 +/- 0.01 ml/min. Cp of CO2 measured after the first five minutes of dwell underestimated EPBF. In normally hydrated rats, maximum nUFR was achieved when the peritoneal filtration fraction was 32 +/- 2%. This value is similar to the glomerular filtration fraction in rats of 30%. Thus, our results indicate the following relationships: EPBF = (approximately 3 x maximum nUFR)/(1 - hematocrit). EPBF was about six times greater than maximum nUFR and exceeded about 57 times nUFR obtained under isosmotic conditions. These differences between EPBF and nUFR suggest normal EPBF is not a major limiting factor for maximum ultrafiltration achieved during peritoneal dialysis.

Animals↗
PubMed1991

Sieving and reflection coefficients for sodium salts and glucose during peritoneal dialysis in rats.

The two-part studies reported herein address peritoneal membrane ultrafiltrate (UF) characteristics during peritoneal dialysis exchanges in rats. In the studies of part 1, the sieving coefficients for sodium, chloride, and total solutes during hydrostatic UF after instillation of rat serum into the peritoneal cavity of rats were calculated. Thirty-six rats were divided into six groups (N = 6) according to the following peritoneal dialysis exchange cycle times: 60, 120, 180, 240, 480, and 960 min. Thirty milliliters of pooled rat serum were infused i.p. with the animal being conscious except during infusion and drainage. The study showed in the early phase of exchanges, when oncotic and osmotic pressure gradients were absent, net UF presumably due to capillary hydrostatic pressure and sodium sieving during such UF. Sieving coefficients for sodium (0.72), chloride (0.77) and total solutes (0.73) were determined by using standard formulae. In the second part of these studies, the kinetics of fluid movement after the instillation of 5% dextrose solution into the peritoneal cavity of rats were analyzed. A very low UF rate was observed early in the exchange when the glucose gradient between the dialysis solution and blood was at its peak. The UF rate gradually increased as the sodium entered the dialysis solution from the blood. At the time of low UF rate with high glucose gradient, presumably the osmotic pressure generated by the glucose in the dialysis solution was countered by the osmotic pressure of solutes in plasma, i.e., sodium and its anions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[In vitro cytotoxicity of Ganoderma lucidum on oral cancer cells].

The extract from the mycelium of Ganoderma lucidum was diluted into serial concentrations and added into in vitro cultured oral cancer and normal cell lines. After incubation for 24 hours, the survival fraction was determined by MTT colorimetric assay. The result revealed that the ID50 was about 3mg/ml and the total lethal dosage was beyond 4 mg/ml. This toxic effect was the same in both cancer and normal cells. Not only was there no difference between cancer and normal cells, but also the high dosage required in toxicity leads to the conclusion that the GL has no direct cytotoxic effect in cancer treatment.

Antineoplastic Agents, Phytogenic↗
PubMed1990

Renal excretion of zinc in patients with chronic uremia.

Though uremic patients have been reported to have subnormal zinc levels in plasma and an abnormal zinc metabolism, data on their renal excretion of zinc are still unavailable. In our study, 55 nondialyzed uremic patients had a markedly lower concentration of zinc in plasma and a lower urinary zinc excretion. They had a higher excretory fraction of zinc in the renal tubules and a higher ratio of zinc to creatinine excretion than normal subjects. We found that the total daily excretion of zinc, calcium, phosphate and ammonia was reduced, and that the ratio of calcium or ammonia to creatinine excretion decreased in uremic patients. Urinary zinc excretion was correlated with renal creatinine clearance (r = 0.50, p less than 0.001) in both normal subjects and uremic patients, but ammonia excretion was correlated with zinc excretion in normal subjects only. In uremia, urinary zinc excretion was correlated with urinary calcium (r = 0.55, p less than 0.001) and urinary phosphate excretion (r = 0.30, p less than 0.05). We conclude that the increased ratio of zinc to creatinine excretion and the excretory fraction of zinc in the renal tubules of uremic patients may increase the urinary zinc excretion, but a severe diminution of the glomerular filtered load of zinc may be the major factor in decreasing the urinary zinc excretion in uremia.

Adult↗
PubMed1990

Renal excretion of oxalate in patients with chronic renal failure or nephrolithiasis.

This study was carried out in order to investigate renal oxalate excretion in a group of normal subjects (n = 40), a group of patients with uremia (n = 52) and a group with nephrolithiasis (n = 34). We found that the mean concentrations of oxalate in the 24-hour urine specimens of both patient groups were below the normal range. Although the renal creatinine clearance (CCR) was significantly decreased in some stone patients (n = 14), decreased renal oxalate clearance was noted only in those patients with severe renal failure. Thus, plasma oxalate was found to be elevated only in patients with chronic renal failure (mean +/- SD, 49.7 +/- 12.4 mumol/l), while the normal value was 17.0 +/- 6.7 mumol/l. The mean tubular excretion fraction of oxalate was also found to increase markedly in uremia with a mean of 26.3 +/- 17.3% (in normal subjects, 11.7 +/- 7.5%), but their mean daily urinary excretion of oxalate decreased to 63.2 mumol/day (mean value of 232.6 mumol/day in normal subjects). A positive correlation was observed between oxalate and creatinine, and between oxalate and calcium excretion, which was not found in normal subjects or patients with kidney stones. In nephrolithiasic patients, the daily excretion of oxalate, calcium and phosphate had no discernible increment and the mean excretory ratio of oxalate, calcium or phosphate to creatinine was all within normal limits. But when the CCR of stone patients was below 80 ml/min, their daily excretion of oxalate and calcium decreased significantly (p less than 0.01) and the excretory ratio of phosphate to creatinine markedly increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Interzeta-globin gene hypervariable regions in Chinese: application to genetic diagnosis of adult polycystic kidney disease.

In order to investigate the interzeta-globin gene hypervariable regions (IZHVR) in Chinese, DNA samples from 114 unrelated normal individuals were analyzed using the restriction endonuclease BglII and hybridized with a 32P-labeled zeta-globin probe. Four polymorphic fragments containing IZHVR with different frequencies were found: 11.3 kb, 0.24; 10.8 kb, 0.50; 10.4 kb, 0.05, and 10.0 kb, 0.21. Using these polymorphic fragments as linkage markers, we were able to trace the affected siblings in a three-generation Chinese family with a history of adult polycystic kidney disease.

China↗
PubMed1988

Pancreatic enzymes in uremic patients with or without dialysis.

One hundred thirty blood samples from 87 patients with renal failure, but without abdominal pain, were analyzed for blood urea nitrogen (BUN), creatinine, amylase, p-isoamylase, and lipase simultaneously. We found that 74, 78, and 80% of the patients had hyperamylasemia, hyperisoamylasemia, and hyperlipasemia. None had amylase higher than five times the upper limit. A few patients (2.3%) had lipase elevated to more than 10 times the upper limit. No significant change of pancreatic enzyme level was noted as a result of hemodialysis, but a significant amount of amylase was removed from the circulation in patients receiving intermittent peritoneal dialysis. Significantly lower pancreatic enzyme levels were observed in patients with less impairment of renal function. We conclude that elevation of pancreatic enzymes in uremic patients is more frequent and more extensive than most articles indicate, and that the extent of increase is related more to renal function than to the modalities of dialysis the patients received.

Adult↗
PubMed1984

Activities of fatty acid desaturases and fatty acid composition of liver microsomes in rats fed beta-carotene and 13-cis-retinoic acid.

The fatty acid composition of microsomal lipids and the activities of delta 9- and delta 6-desaturases in liver microsomes of rats fed diets supplemented with beta-carotene and two levels of 13-cis-retinoic acid were studied. Four groups of male, weanling rats were fed semipurified diets containing 0 or 100 mg beta-carotene per kg diet, and 20 or 100 mg 13-cis-retinoic acid per kg diet. After 11 weeks of feeding, the rats were killed, liver microsomes were prepared and assayed for delta 9-desaturase and delta 6-desaturase activities. The activity of delta 9-desaturase was lower in liver microsomes of rats fed beta-carotene-supplemented diet or the diet supplemented with the higher level of 13-cis-retinoic acid. Microsomal delta 6-desaturase activity was, however, higher in liver of rats fed 13-cis retinoic acid; there was no effect of beta-carotene on delta 6-desaturase activity. The fatty acid compositional data on total lipids of liver microsomes were consistent with the diet-induced changes in fatty acid desaturases. Phospholipid composition of liver microsomes was also altered as a result of feeding beta-carotene or 13-cis-retinoic acid-containing diets. The proportions of phosphatidylethanolamine were generally higher, whereas those of phosphatidylcholine were lower in the experimental groups as compared with the control.

Animals↗
PubMed1983

Effect of probenecid on the pharmacokinetics of aminophylline.

The authors investigated the effect of probenecid on the pharmacokinetics of aminophylline. Seven normal volunteers served as their own controls in a crossover study. In the first phase, subjects received an oral dose of aminophylline after an overnight fast. In the second phase, probenecid was given orally 30 minutes prior to the administration of aminophylline. Serum and urine theophylline levels were determined by high performance liquid chromatography. Statistical analysis showed that probenecid had no significant effect on any of the pharmacokinetic parameters measured. Probenecid appears to have little or no influence on the liver metabolism of theophylline.

Aminophylline↗
PubMedDate not supplied

Peritoneal transfer of carbon dioxide in the rat.

In the authors' previous rat studies (Kidney Int 39: 608-617, 1991), peritoneal clearances (Cp) representing near exclusively diffusive CO2 transfer were evaluated: for isosmotic (0.37% dextrose) and hyperosmotic (15% dextrose) solutions with pH 7.2-7.3, Cp CO2 were 1.20 +/- 0.08 and 1.84 +/- 0.04 ml/min, respectively. In the present studies peritoneal transfer parameters (D/B, Cp) of CO2 gas, HCO3-, and total CO2 (tCO2) in anesthetized rats have been compared (n = 22) using solutions with dextrose contents as mentioned above but with a pH of 6.5 or 7.6; how much Cp CO2 measurements obtained with solutions at these pH values differ from Cp shown earlier with solutions of pH 7.2-7.3 has also been evaluated. When the pH was the same, transfer parameters of CO2 gas, HCO3-, and tCO2 were significantly higher under hyperosmotic conditions. The use of solutions with a pH different from 7.2-7.3 resulted in higher Cp of CO2 gas: with isosmotic solutions at pH 6.5 and 7.6, mean increases were 25 and 75%, respectively; with hyperosmotic solutions respective increases were 45 and 134%. The authors conclude that dialysis solution pH, especially under hyperosmotic conditions, significantly changes parameters of diffusive CO2 transfer in the rat. For evaluation of peritoneal blood flow from diffusive transfer parameters of CO2 gas, smaller overestimation can be expected when dialysis solution pH is slightly under than overadjusted compared to blood pH.

Animals↗