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Biomedical subjects

S M Liu

Publications and source records attributed to S M Liu.

At least 37 records · Page 2Linked to original sources
PubMed2000

Angiotropic lymphoma manifesting as a solitary adrenal tumor in a case of ankylosing spondylitis.

Angiotropic lymphoma is an extremely rare disease characterized by intravascular accumulation of large neoplastic lymphocytes, with the clinical manifestations of fever, skin lesions and neurologic deficits. We report a patient who developed angiotropic lymphoma after a 10-year history of ankylosing spondylitis. The clinical disease manifested as a unilateral, solitary adrenal tumor, fever and body weight loss. The fever subsided after surgical removal of the adrenal tumor. Systemic chemotherapy was administered postoperatively. The patient was leading an uneventful life 44 months after the initial diagnosis. To our knowledge, this is the first case of angiotropic lymphoma associated with ankylosing spondylitis. It is also the second reported case manifesting with a unilateral solitary adrenal tumor without systemic involvement.

Adrenal Gland Neoplasms↗
PubMed2000

Transsulfuration, protein synthesis rate and follicle mRNA in the skin of young Merino lambs in response to infusions of methionine and serine.

Methionine (Met) is usually the first limiting amino acid for sheep and supplements of Met may increase production of wool and meat. The wool response may be due to an increased supply of cysteine (Cys) from transsulfuration (TS) of Met. Met is catabolized through homocysteine to form Cys when the S from Met is transferred to serine (Ser). We hypothesized that providing additional Met would create a deficiency of Ser and that by simultaneously providing Met and Ser, TS and wool growth could be increased more than by providing Met alone. The effects of i.v. infusions of Met and Ser to young Merino lambs on TS, fractional synthesis rate (FSR) of protein in skin, follicle mRNA and wool growth were examined. Following 4 d of constant i.v. infusion of 3 g Met/d, or 10 g Ser/d or both, the isotope tracers: L-[3-(13)C]Cys, L-[ring-d5]phenylalanine (Phe) and L-[2,3,3-d3]Ser were infused over 8 h to allow for measurements of irreversible loss rate (ILR), and TS in whole body and skin. Skin biopsies were taken for measurement of FSR. Wool growth rate was measured using autoradiography. An infusion of Met significantly (P < 0.05) improved wool growth rate and increased skin FSR, Cys supply from TS and enhanced levels of follicle mRNA (from the K2.10 intermediate filament gene and three gene families encoding keratin associated proteins KAP1, KAP4 and KAP12). The extra Met lowered Ser ILR. The infusion of Ser doubled Ser ILR in the body and increased skin FSR calculated using the Cys tracer in plasma (P < 0.05). However, there were no significant (P > 0.05) changes in TS, skin FSR calculated using the Phe and Ser tracers, follicle mRNA or wool growth rate as a result of Ser infusion. While there were trends towards increased TS and FSR with Ser infusion, the overall lack of significant changes indicates a high capacity for the de novo synthesis of Ser.

Animals↗
PubMed2000

Comparison of three chronic dialysis models.

The chronic peritoneal dialysis model is important for understanding the pathophysiology of peritoneal transport and for studying biocompatibility of peritoneal dialysis solutions. In this study, we compared three different chronic peritoneal dialysis models. A peritoneal catheter was placed in 23 male Sprague-Dawley rats, 12 of which had an intact omentum (model 1) and 11 of which received an omentectomy (model 2). Seven other rats, without a catheter, received a daily intraperitoneal injection (model 3). Each rat received a daily infusion of 25 mL of 3.86% glucose dialysis solution either through the catheter (models 1 and 2) or through injection (model 3) for 4 weeks. Then, a 4-hour dwell study using 3.86% glucose solution with an intraperitoneal volume marker and frequent dialysate and blood sampling was performed in each rat. The intraperitoneal volume was significantly lower in all the dialysis groups as compared to a control group (n = 6) in which the rats had no chronic dialysate exposure. The peritoneal fluid absorption rate, as well as the direct lymphatic absorption rate, was significantly higher in the three dialysis groups as compared to the control group. In general, no significant differences were seen in any of the parameters among the three dialysis models. Owing to catheter obstruction, three rats in model 1 and four rats in model 2 were lost during dialysis. Histological examination showed no significant differences among the three dialysis groups. Our results suggest that omentectomy may not be necessary in the chronic peritoneal dialysis model when using dialysate infusion and no drainage. Based on the present study, we think that perhaps model 1 may be the method of choice to test new peritoneal dialysis solutions. However, owing to its simplicity, model 3 could also be used if great care is taken to avoid puncturing the intestine or injecting into the abdominal wall.

Absorption↗
PubMed1999

Modeling the effects of sodium chloride on degradation of chloramphenicol in aquaculture pond sediment.

Sodium chloride was added to aquaculture pond sediment to determine effects of different salinities on degradation of chloramphenicol (CM). In this experiment, freshwater (0 ppt salinity) eel pond sediment slurries (10% w/v) were amended with sodium chloride to obtain salinities of 12, 24 and 36 ppt. There were no significant differences in sorption rate either between aerobic and anaerobic conditions or among various salinities. Degradation of CM fitted well to the decaying exponential curve. The degradation rates under anaerobic conditions were significantly greater than those under aerobic conditions. As salinity increased, the degradation rates decreased under both aerobic and anaerobic conditions. The differences in degradation rates either between aerobic and anaerobic conditions or among various salinities were attributed to the effects of microbial activities under different environments.

Anaerobiosis↗
PubMed1999

Diagnostic and prognostic values of plasma levels of fibrinolytic markers in ovarian cancer.

OBJECTIVE: The aim of this study was to find out whether any of the fibrinolytic parameters could be used as tumor markers in predicting the prognosis of ovarian cancers. MATERIALS AND METHODS: In the present study, we determined the plasma concentrations of tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), PAI-2, and uPA receptor (uPAR) in 25 patients with ovarian cancer, 16 patients with benign gynecologic tumor or inflammation, and 36 healthy controls in order to find out whether the plasma levels of these markers could be used to evaluate the prognostic value in patients with gynecologic cancers. We also determined two tissue concentrations of malignant tumor (one was at the tumor site itself and the other at the cut-end tissue of the tumor, which was expected to be free of tumor) in order to see the correlation between plasma and tissue concentrations. RESULTS: Plasma PAI-1 was significantly higher in patients with malignancy than in the healthy controls (P = 0.0001). There was no significant correlation between plasma and tissue concentrations, either tumor tissue or cut-end tissue, of the same parameters. Tissue concentrations of uPA, PAI-1, and PAI-2 were significantly higher and tPA significantly lower in the malignant tumor tissue than in the cut-end tissue in the patients with ovarian cancer (P = 0.014, 0.03, 0.002, and 0.01, respectively). Plasma PAI-1 was significantly higher in patients in the late stage of ovarian cancer than in the early stages and in the controls. CONCLUSION: From our study, we concluded that plasma levels of PAI-1 were correlated with the presence of malignant ovarian cancer and higher stage of disease.

Adult↗
PubMed1999

Neuropeptide Y overexpression in the preweanling Zucker (fa/fa) rat.

Hypothalamic preproNPY overexpression in the Zucker fatty (fa/fa) rat was examined. In situ hybridization was used to determine the relative level of preproNPY mRNA in the arcuate nucleus of +/+, +/fa, and fa/fa pups aged postnatal day 2 (P2), 5, 9, 12, or 25. The relative optical density (ROD) of probe hybridization in the arcuate, the area of hybridization (A), and the product of ROD x A (a measure of total arcuate preproNPY mRNA hybridization) were measured. Values were normalized to the mean +/fa value within each litter. Initial analysis showed that preproNPY mRNA hybridization (ROD x A) in fa/fa pups was significantly higher than +/fa and +/+ pups on P9, 12, and 25, and significantly higher than +/fa on P5. No significant difference between lean (+/+ and +/fa) genotypes, however, were observed at any age tested. Values from the lean genotypes were, therefore, pooled, and data were normalized to the mean value of lean animals for analysis. This analysis revealed that preproNPY mRNA hybridization in fa/fa pups was higher than lean littermates as early as P2.

Aging↗
PubMed1999

Biodegradation of coplanar polychlorinated biphenyls by anaerobic microorganisms from estuarine sediments.

In this study, we investigated the biodegradability of biphenyl and 5 congeners (one non-planar and four coplanar) of polychlorinated biphenyl (PCB). Biphenyl, the non-planar congener 2,3',4',5-tetrachlorobiphenyl (25-34 CB), and the four coplanar congeners 3,3',4,4'-tetrachlorobiphenyl (34-34 CB), 3,4,4',5-tetrachlorobiphenyl (345-4 CB), 3,3',4,4',5-pentachlorobiphenyl (345-34 CB), and 3,3',4,4',5,5'-hexachlorobiphenyl (345-345 CB) were amended at a concentration of 10 mg/L into anoxic sediment slurries collected from the estuaries of the Tansui River and the Erjen River. During 2 years' incubation under sulfidogenic conditions, biphenyl was persistent, while all other chlorinated congeners, except for 345-345 CB, were dechlorinated with or without a lag period in sediment slurries collected from both rivers. Dechlorination of coplanar and non-planar congeners began with para chlorine removal. All para chlorines from the mono-, di-, and trichlorobiphenyl groups could be removed by sediment slurries from both rivers. Microbial communities in sediment from the Erjen River additionally fostered meta-dechlorination activity, but only after removal of all the para chlorines. Addition of Tween 20 (0.05%, v/v) into sediment slurries from the Tansui River did not enhance dechlorination rates or extents, but the addition of toluene- or 3-chlorobenzoate-adapted sediments enhanced dechlorination of 34-34 CB and 345-4 CB.

Anaerobiosis↗
PubMed1999

Principles underlying the organization of movement initiation from quiet stance.

The purpose of this study was to determine common principles underlying the programming of movement initiation from quiet stance. Subjects were asked to initiate gait, step over a ruler, or to step over a 10 cm high obstacle at a self-paced speed and as fast as possible. The independent variables were initiation condition (gait initiation, stepping over a ruler or obstacle) and initiation speed (self-paced and as fast as possible). The dependent measures for the stance limb only were the latency between postural soleus (S(1)) EMG inhibition and tibialis anterior (TA) EMG onset, the duration of both TA and soleus (S(2)) activity following TA, duration and slope, impulse, and peak forces of the anterior-posterior (Fx) ground reaction force. Selected timing events were also monitored. Analysis of variance was used to determine main and interaction effects. The following results were obtained. (1) The interval from the inhibition of S(1) postural activity to the onset of TA remained invariant between all conditions. (2) The duration of TA increased and S(2) decreased with an increase in speed of initiation. There was no difference in TA and S(2) duration between the initiation conditions. (3) Time to heel-off remained invariant for all conditions. (4) Prior to heel-off all force variables increased with initiation speed but were similar between initiation conditions. After heel-off force variables were different between speeds and conditions being greater for fast speed and stepping over the obstacle. Two conclusions may be drawn from this study. First, the results indicate that gait initiation consists of two, highly coordinated motor programs. Heel-off of the stance limb is the division between these two programs. Second, our findings also suggest that gait initiation and stepping are governed by the same motor programs.

Adult↗
PubMed1999

Massive ascites caused by peritoneal extramedullary hematopoiesis as the initial manifestation of myelofibrosis.

An 83-year-old man presented with massive ascites. Cytological examination of the ascites revealed primitive hematopoietic cells. The specimen of bone marrow biopsy disclosed diffuse fibrosis, which suggested myelofibrosis with extramedullary hematopoiesis as the cause of ascites. His symptoms resolved dramatically after administration of hydroxyurea. Ascites formation in myelofibrosis is often attributed to presinusoidal portal hypertension and occurs in the context of well-established disease. This case demonstrates that myelofibrosis may manifest as massive ascites caused by peritoneal implants of myeloid tissues. Extramedullary hematopoiesis should be included in the differential diagnosis of ascites.

Aged↗
PubMed1998

Expression of Epstein-Barr virus in patients with Hodgkin's disease in Taiwan.

BACKGROUND: The association of Epstein-Barr virus (EBV) with Hodgkin's disease (HD) is intimately related to socioeconomic status. The proportion of HD patients with EBV is high in developing countries but low in developed countries. The aim of this study was to delineate the association of EBV with HD in Taiwan. METHODS: Tissues from 70 consecutive cases of HD were examined for the presence of EBV, for the latent membrane protein (LMP- 1) by immunohistochemistry, and for EBER-1 by in situ hybridization. RESULTS: There were 53 males and 17 females, with a mean age of 42 years (range, 7-75 years). Histologic subtypes included nodular sclerosis in 36 cases (51.4%), mixed cellularity in 26 (37.1%), lymphocyte predominance in 6, and lymphocyte depletion in 2. Overall, EBV was expressed in 44 cases (62.9%), with EBER-1 expression detected in 40 (57.1%) and LMP-1 detected in 38 (54.3%). The following histologic subtypes were associated with EBV: lymphocyte predominance in 1 of 6 cases (16.7%), nodular sclerosis in 23 of 36 cases (63.9%), mixed cellularity in 18 of 26 cases (69.2%), and lymphocyte depletion in 2 of 2 cases (100%). CONCLUSIONS: EBV association with HD is relatively high in Taiwan. Although EBV was detected in all subtypes and at all ages in this study, the low endemic incidence of HD in Taiwan suggests that other factors, besides EBV, play a role in the pathogenesis of HD.

Adolescent↗
PubMed1998

Diagnostic and prognostic values of plasma levels of fibrinolytic markers in gastric cancer.

In the present study, we determined the plasma and tissue concentrations of tissue-type plasminogen activator, urokinase-type plasminogen activator, plasminogen activator inhibitor-1, plasminogen activator inhibitor-2 and urokinase-type plasminogen activator receptor in 32 patients with pathology-proved gastric cancer. The plasma levels of the same markers were compared in 37 patients with benign gastric ulcer in order to find out if these plasma levels could be used to evaluate the prognostic value in patients with gastric cancer. Plasma plasminogen activator inhibitor-1 was significantly higher in gastric cancer than in benign gastric disease (p < 0.0005), whereas plasma urokinase-type plasminogen activator was significantly lower in patients with gastric cancer than in those with benign ulcer (p = 0.003). There was no significant correlation between tissue and plasma concentrations of the same parameters. The plasma and tissue levels of fibrinolytic parameters were not affected by tumor size or distant metastasis, whereas tumor tissue concentration of urokinase-type plasminogen activator receptor and plasminogen activator inhibitor-2 were significantly higher in N0 than in N1 and N2, and tissue plasminogen activator inhibitor-1 was significantly higher in N0 than in N1. Plasma levels of the five fibrinolytic parameters could not take the place of the corresponding tissue concentrations on the diagnosis and prediction of prognosis in patients with gastric cancer. Tissue concentrations of urokinase-type plasminogen activator receptor and plasminogen activator inhibitor-2, especially the latter, can be used to predict lymph node involvement in patients with gastric cancer.

Aged↗
PubMed1998

Gas chromatography/mass spectrometry analyses of [2,3,3-d3] serine, [2,3,3-d3] cysteine and [3-13 C] cysteine in plasma and skin protein: measurement of transsulphuration in young sheep.

A new procedure using stable isotope labelled serine (L-[2,3,3-d3] serine) and cysteine (L[13-3-13 C] cysteine) and analysis by gas chromatography/mass spectrometry (GC/MS) has been developed to measure transsulphuration in sheep. The enrichments of the tracers in plasma and skin biopsy samples were measured by GC/electron impact MS analysis of the t-butyldimethylsilyl derivatives. The measured recoveries of the standards enriched with [3-13 C] cysteine from 0.1% to 8%, or with [2,3,3-d3] serine from 0.14% to 14% were greater than 99% of the theoretical values, and the variation coefficients were less than 3% when the enrichment was higher than 0.5%. The use of dithiothreitold (DTT) as a reducing agent before deproteinization of the sample and during the derivatizations successfully increased the cysteine peak area and significantly improved reproducibility in the analysis. The cysteine residues in protein from the skin biopsy were also during the protein hydrolysis with DTT in 6 n HCI. The method was applied to measure transsulphuration of methionine in young sheep. The amount of cysteine derived from transsulphuration accounted for 17% to 21% of the irreversible loss rate of cysteine, depending on the substrate supplies. The results are consistent with other reports. Compared with conventional methods of measuring transsulphuration using radioactive isotopes, the processes of animal experimentation was sample analysis were simple, and there were no radiation hazards. The method should prove useful in studies on the metabolism of methionine and cysteine in human and animals.

Amino Acids, Sulfur↗
PubMed1998

Toxicity and anaerobic biodegradability of pyridine and its derivatives under sulfidogenic conditions.

Attempts were made to correlate the chemical structure of pyridine and 15 pyridine derivatives with both their biodegradability by estuarine sediment microorganisms under anaerobic conditions and also with their toxicity to the marine bacterium Vibrio fischeri Beijerinck 1889 by using the Microtox bacterial assay. Among monosubstituted pyridines, comparisons of different substituents at positions C-2, C-3, or C-4 atom of the pyridine ring showed that isomers of carboxylpyridine (COOHPYR), hydroxypyridine (OHPYR), and cyanopyridine (CNPYR) were more susceptible to biotransformation than isomers of chloropyridine (ClPYR) and methylpyridine (CH3PYR) in anoxic estuarine sediment slurries under sulfidogenic conditions. Isomers with the functional group at the C-2 or C-3 atom of the pyridine ring were biotransformed faster than those with the same functional group at C-4. The only exception was 4-ClPYR, which was biotransformed within 130 days, while 2- and 3-ClPYR continued to persist in the anoxic sediment slurries. Median effect concentrations (EC50) of pyridine and pyridine derivatives were in the range of 0.027 to 49.1 mmol/L. Pyridine derivatives with -CN and -OH functional groups tended to be less toxic, while pyridine derivatives with -CH3, -Cl, and -COOH functional groups tended to be more toxic. Isomers with the substituent at C-2 were less toxic than the C-3 or C-4 isomers. There was no clear correlation between the pseudo-first-order rate constants for the microbial transformation of pyridine and its derivatives and their toxicity to the marine bacterium.

Anaerobiosis↗
PubMed1998

The influence of live weight, live-weight change and diet on protein synthesis in the skin and skeletal muscle in young Merino sheep.

Wool growth is derived directly from protein synthesis in the skin of sheep, and is affected by the nutritional status of the animals. The present experiment examined both protein synthesis in the skin and muscle and wool growth in Merino lambs differing in live weight, intake and dietary protein source. The experiment was a 2(3) factorial design: twenty-four 5-month-old lambs initially weighing 33 kg (heavy) or 25 kg (light) were fed on a hay-based diet with either lupin seed or rapeseed meal as the major protein sources to maintain live weight (M) for 56 d, or were fed at 0.6 M for 28 d (period 1) followed by 28 d at 1.6 M (period 2). Fractional protein synthesis rates (FSR, % per d) in the skin and the m. longissimus dorsi on days 4 and 24 of period 1 and day 4 of period 2 were measured by means of a flooding dose of L-[ring-d5]phenylalanine, and wool growth on a skin patch over period 1 was also measured. The FSR ranged from 13.2 to 20.2% per d in the skin, higher than reported for other breeds, and 1.53-3.07% per d in the muscle. Sheep on the low intake (0.6 M) had significant reductions in FSR, protein content (g), protein synthesis (g/d) in the skin, and wool growth (g/d). The heavy lambs had similar FSR to the light lambs, but had a higher skin protein content and total protein synthesis per unit of skin area (100 cm2) and, therefore, grew more wool. The rapeseed-meal diet increased FSR and wool growth only in the light lambs over the short term. The protein deposited in wool over period 1 was 0.185 of the total protein synthesis in the skin, regardless of live weight, intake or diet, a result similar to other breeds. With the changes in dietary intake, protein synthesis in the skin and muscle responded differentially, with nutrient partitioning at sub-maintenance in favour of wool growth but at supra-maintenance, following a nutrient restriction, in favour of weight gain in young growing sheep.

Animal Nutritional Physiological Phenomena↗
PubMed1998

Continuous infusion cisplatin and etoposide chemotherapy for cancer of unknown primary site (CUPS) in Taiwan, a region with a high prevalence of endemic viral infections.

BACKGROUND: To evaluate the efficacy and toxicity of cisplatin/etoposide continuous infusion chemotherapy for cancer of unknown primary site in Taiwan, a region with a high prevalence of endemic viral infections. METHOD: Between April 1994 and February 1996, 20 patients with a diagnosis of CUPS were treated, including 15 males and five females, of average age 63.3 years (range 41-83 years). Continuous intravenous infusion of etoposide 80 mg/m2 and cisplatin 25 mg/m2 was given for 3 days every 3 weeks. Pretreatment tumor marker and viral serology studies were performed for baseline evaluation. Nearly two-thirds of the patients had poorly differentiated carcinoma. The average number of metastatic sites was 2.65 (range 1-4), with liver and lymph node involvement predominating. RESULTS: The overall response rate was 25% (95% CI 17.7-32.3%); 30.7% for poorly differentiated cancers and 25% for well differentiated cancers. Median survival was 4 months (range 1-12 months), 4.8 months for patients attaining partial response. Toxicity was moderate, grade 3 and 4 neutropenia occurred in 55% and grade 3 and 4 thrombocytopenia in 40%; other toxicities were mild. CA125 and CA199 were elevated in more than 50% of patients. Viral serology studies were not significantly different from those of the indigenous population. CONCLUSION: Etoposide and cisplatin combination chemotherapy has modest activity in patients with extensive CUPS and, at the schedule and dosage given, it is associated with moderate toxicity.

Adult↗
PubMed1998

Inhibition of postvitrectomy fibrin using troxerutin.

PURPOSE: To evaluate the efficacy of intraocular infusion of troxerutin in the inhibition of fibrin formation after vitrectomy in a rabbit model. METHODS: Lensectomies and vitrectomies were performed in a masked fashion on seven eyes treated with a 10-mM infusion of troxerutin and on seven control eyes that received only a balanced salt solution infusion. Masked grading of intraocular fibrin formation and intravitreal hemorrhage was performed for 1 week. RESULTS: On postoperative days 1 and 2, the control group exhibited a greater mean fibrin index (MFI) percentage than the troxerutin-treated group (day 1, 27.7% versus 19.5% MFI; day 2, 14.5% versus 6.1% MFI, respectively). On postoperative day 3, both groups showed an MFI of 1.8%. On postoperative days 5 and 7, both groups showed only minimal presence of fibrin. Neither of the two groups had an increased rate of intraocular hemorrhage. CONCLUSIONS: Infusion of 10 mM troxerutin resulted in a relative decrease in the amount of fibrin produced without an increased risk of intraocular hemorrhage in treated eyes compared with controls, but the difference was not statistically significant. Further studies may be warranted to evaluate the optimal dose of troxerutin alone or a possible role for its use in conjunction with other drugs employing a different mechanism of action in the prevention of fibrin formation.

Animals↗