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J C Tsai

Publications and source records attributed to J C Tsai.

At least 19 recordsLinked to original sources

Decreased B cells and IgA-secreting B cells partially explain the high prevalence of IgA deficiency in dialysis patients.

AIMS: We previously reported 2 hemodialysis (HD) patients with recurrent infections and selective immunoglobulin A deficiency (IgAD). We further demonstrated that serum IgA levels were lower and the prevalence of IgAD was higher in uremic patients. The exact mechanisms of IgAD in uremic patients largely remained unclear. In some patients, it was caused by anti-IgA antibody neutralization and subsequent destruction. We performed the present study to survey if there is any defect in IgA production. MATERIALS AND METHODS: 288 patients were initially included for examination of serum immunoglobulins. 16 normal persons, 16 dialysis patients without IgAD, and 12 dialysis patients with IgAD were enrolled after the initial examination. Blood was drawn into heparinized tubes. WBC counts and lymphocyte percentage were examined by a CBC counter. Lymphocytes were separated by the Ficoll-Paque method. Flow cytometry was utilized to isolate the B cell and IgA-secreting B cell after staining with CD 19 phycoerythrin and FITC-conjugated rabbit anti-human IgA antibody. RESULTS: There is no significant difference between WBC counts or total lymphocyte counts of these 3 groups. However, we found a lower percentage of total lymphocyte counts in dialysis patients, either with or without IgAD. The total B cell numbers were lower in dialysis patients with IgAD. In addition, there were fewer IgA-secreting B cells in dialysis patients with IgAD. CONCLUSION: Decreased B cell and IgA-secreting B cell counts are seen in uremic patients with IgAD. This, in turn, indicates that there might be a defect of IgA production in some patients, rather than IgA destruction by anti-IgA antibodies as seen in some other patients. Further study is needed to investigate the mechanisms of decreased B cells and IgA-secreting B cells.

Adult↗

7-84 parathyroid hormone fragments are proportionally increased with the severity of uremic hyperparathyroidism.

AIMS: Recent progress in PTH assay has revealed that the intact PTH assay kit in current use does not differentiate between the truncated 7-84 PTH molecule and the 1-84 PTH molecule. In our series, we examined the effectiveness of a new PTH assay as a noninvasive method of evaluating severity of uremic hyperparathyroidism. METHODS AND MATERIALS: Two hundred and seventy hemodialysis (HD) patients recruited from three HD centers were included and divided into subgroups according to the conventional iPTH assay results. Pre-dialysis blood samples were collected and subjected to two different PTH assays: "intact" PTH assay (iPTH) and "whole" PTH (wPTH) assay. Two biochemical markers of bone remodeling were also examined. RESULTS: In all cases, PTH levels determined by the wPTH assay were in the average 32.3% lower than those determined by the iPTH assay. The difference of the results of the two PTH assay methods, which indicated the portion of 7-84 PTH fragments of the total PTH molecules measured with the iPTH assay, was gradually increased while the severity of uremic hyperparathyroidism increased. Biochemical markers of bone formation/resorption showed a similar change. CONCLUSION: The portion of the 7-84 PTH fragments and markers of increased bone turnover increased in proportion to the severity of uremic hyperparathyroidism. This finding disproves the hypothetical role of 7-84 PTH fragments alone as the noninvasive marker of low-turnover bone disease in HD patients.

Adult↗

The effects of exercise training on walking function and perception of health status in elderly patients with peripheral arterial occlusive disease.

OBJECTIVE: To determine the effects of 12-week exercise programme on ambulatory function, free-living daily physical activity and health-related quality of life in disabled older patients with intermittent claudication. DESIGN: Prospective, randomized controlled trial. SETTING: University Medical Center and Veterans Affairs Medical Center, Taipei, Taiwan. SUBJECTS: Thirty-two of 64 patients with Fontaine stage II peripheral arterial occlusive disease (PAOD) were randomized to exercise training and 32 to usual care control. Five patients from the exercise group and six patients from the control group dropped out, leaving 27 and 26 patients, respectively, completing the study in each group. INTERVENTIONS: Twelve weeks of treadmill exercise training. MAIN OUTCOME MEASURES: Treadmill walking time to onset of claudication pain and to maximal claudication pain, 6-min walk distance, self-reported ambulatory ability and perceived health-related quality of life (QOL). RESULTS: Compliance of exercise programme was 83% of the possible sessions. Exercise training increased treadmill walking time to onset of claudication pain by 88% (P < 0.001), time to maximal pain by 70% (P < 0.001), and 6-min walk distance by 21% (P < 0.001). SUBJECTS: Perception of health-related QOL improved from 12% to 178% in the exercise group. These improvements were significantly better than the changes in the control group (P < 0.05). CONCLUSIONS: Significant improvements in claudication following 12-week exercise training in elderly PAOD patients were observed. Increase in treadmill walking time to maximal claudication pain in these patients translated into the improvement of perceived physical health, which enabled the patients to become more functionally independent.

Aged↗

Two-dimensional granular Poiseuille flow on an incline: multiple dynamical regimes.

We investigate experimentally the flow of a monolayer of spherical beads through a channel on a smooth incline that is bounded by rough sidewalls. Using high-speed video imaging and particle tracking, we measure the positions and velocities of all particles in the field of view. We find that the flows are accelerating and dilute if the channel exit is open. On the other hand, if the exit is constricted, flows can reach a state in which the local time-averaged velocity is invariant along the stream. In the latter case, we find a continuous transition from an oscillatory two-phase flow (2PF) regime with wide density variations to a uniform dense flow regime, depending on the channel width and the mean flow speed. These two regimes exhibit distinct density variation, time regularity, and transverse profiles. The rough sidewalls are found to be necessary for the 2PF regime. In the dense regions of both flows, particles exhibit temporary arches, long-range correlated velocities, inhomogenuous propagation of disturbances, and hexagonal lattice structures. On the other hand, the dilute regions of the two-phase flow are nearly collisionless. Existing models can neither fully describe the dynamics of both the dense and the dilute regions nor explain the spontaneous switching between them.

Journal Article↗

Vascular endothelial growth factor induces manganese-superoxide dismutase expression in endothelial cells by a Rac1-regulated NADPH oxidase-dependent mechanism.

Vascular endothelial growth factor (VEGF) is a potent vascular endothelial cell-specific mitogen that modulates endothelial cell function. In the present study, we show that VEGF induces manganese-superoxide dismutase (MnSOD) mRNA and protein in human coronary artery endothelial cells (HCAEC) and pulmonary artery endothelial cells. VEGF-mediated induction of MnSOD mRNA was inhibited by pretreatment with the NADPH oxidase inhibitors, diphenyleneiodonium (DPI), and 4-(2-aminoethyl)-benzenesulfonyl fluoride, but not with the nitric oxide synthase inhibitor L-NAME (N-monomethyl-L-arginine) or the xanthine oxidase inhibitor allopurinol. VEGF stimulation of MnSOD was also inhibited by adenoviral-mediated overexpression of catalase Cu, Zn-SOD and a dominant-negative form of the small GTPase component of NADPH oxidase Rac1 (Rac1N17). Treatment of HCAEC with VEGF resulted in a transient increase in ROS production at 20 min, as measured by 2,7-dichlorodihydrofluorescein oxidation. This effect was abrogated by expression of Rac1N17. Taken together, these findings suggest that VEGF induces MnSOD by an NADPH oxidase-dependent mechanism and that VEGF signaling in the endothelium is coupled to the redox state of the cell.

Adenoviridae↗

Plasma and urinary endothelin-1 in focal segmental glomerulosclerosis.

The kidney is an important site of endothelin-1 (ET-1) production and is particularly susceptible to ET-1 action. Infusion of ET-1 in rats induces both functional and morphological alterations in the kidneys. Increased plasma level of ET-1 has been reported in patients with chronic renal failure. However, there are still no reports on the plasma and urinary ET-1 levels in patients with focal segmental glomerulosclerosis (FSGS). In the present study, we have measured the plasma concentration and urinary excretion rate of ET-1 in 15 patients with nephrotic syndrome due to FSGS, and observed the serial changes of plasma and urinary ET-1 in nephrotic rats with FSGS, induced by repeated injection with puromycin aminonucleoside (PAN). ET-1 was measured with radioimmunoassay. The results showed that plasma ET-1 concentration in FSGS patients was significantly higher than in normal controls (P < 0.05), and that urinary ET-1 excretion rate was also significantly higher in FSGS patients than in normal controls (P < 0.01). In FSGS patients, the plasma and urinary ET-1 was significantly correlated (P < 0.05), and the urinary ET-1 excretion rate was significantly correlated with the amount of proteinuria (P < 0.05) and the glomerular sclerosing score (P < 0.01). In the ten rats with PAN-induced FSGS, serial examination showed a significant increase in plasma ET-1 after 8 weeks of injections, while the urinary ET-1 excretion rate showed a biphasic increase that showed a peak after 4 to 6 weeks. The same changes in plasma and urinary ET-1 levels were not observed in control rats injected with normal saline at the same frequency. Our results suggest that ET-1 may be involved in the pathogenesis of FSGS in both humans and rats.

Adult↗

Effect of barrier disruption by acetone treatment on the permeability of compounds with various lipophilicities: implications for the permeability of compromised skin.

The permeability of compromised skin barrier was investigated in vitro using acetone-disrupted hairless mouse skin as a model membrane. The effect of compound lipophilicity was studied using sucrose, caffeine, hydrocortisone, estradiol, and progesterone as model compounds. The results demonstrated that permeability barrier disruption by acetone treatment significantly enhanced the permeability of the skin to both hydrophilic and amphipathic compounds, including sucrose, caffeine and hydrocortisone. This effect was more prominent with caffeine and hydrocortisone at different transepidermal water loss (TEWL) levels. Acetone treatment, however, didn't appear to alter the percutaneous penetration of highly lipophilic compounds, such as estradiol and progesterone. The characteristics of skin permeability were described by parabolic relationships between log P(WS) (permeability coefficient of whole skin) and log K(O/W) (octanol/water partition coefficient) at different degrees of permeability barrier disruption. The optimal log K(O/W) of compounds for skin penetration appeared to decrease with an increase in TEWL levels. The maximal permeability achieved was similar through skin displaying different TEWL levels. In an attempt to explore the underlying mechanisms for the changes in skin permeability, the stratum corneum/normal saline partition coefficients of water, caffeine, and hydrocortisone either decreased or remained unaffected with an increase in TEWL. Electron microscopic examinations have revealed reductions in stratum corneum lipid content and alterations in intercellular membrane structures as a result of acetone treatment, whereas negligible changes in the number of horny layers were observed by safranin staining of the stratum corneum. We have concluded that the enhancement in skin permeability to both hydrophilic and amphipathic compounds by acetone treatment arose mainly because of the increase in stratum corneum diffusivity at higher TEWL levels. The results imply the possibility of using both TEWL and drug lipophilicity to predict alterations in skin permeability and hence the dose adjustment of topically applied medication for patients with impaired skin barrier function.

Acetone↗

Molecular weight dependence of polyethylene glycol penetration across acetone-disrupted permeability barrier.

Previous studies have demonstrated that permeability barrier disruption by acetone treatment significantly enhances skin permeability to both hydrophilic and amphipathic compounds, but not to highly lipophilic compounds. The purpose of the present study was to investigate the dependence of permeability on molecular weight (MW) in acetone-disrupted hairless mouse skin in contrast to normal skin. Penetration of polyethylene glycol (PEG) 300, 600, and 1,000 over 12 h was measured using diffusion cells. High-performance liquid chromatographic methods with refractive index detection were used to separate and quantitate the individual oligomeric species in the PEG samples. Percutaneous penetration of PEGs exhibited slightly steeper MW dependency at a transepidermal water loss (TEWL) of 30-41 g/m2 per h in comparison with TEWLs of 0-10 (control skin), 10-20, and 20-30 g/m2 per h, with a higher percentage of smaller oligomer PEGs penetrating than larger ones. Increasing the TEWL of the skin increased the penetration of all the PEG oligomers, and the degree of the enhancement relative to penetration through control skin increased with MW and was maximal for oligomers with a MW ranging from 326 to 414 Da. Within the limit of quantitation of the assay, the MW cut-off for PEG penetration across mouse skin with TEWLs of 0-10, 10-20, and 20-30 g/m2 per h was 414, 590, and 942 Da, respectively, while all the measurable oligomers up to MW 1,074 Da were able to penetrate skin with TEWLs in the range 30-41 g/m2 per h. The results suggest that not only higher amounts but also more varieties of chemicals may penetrate skin with a compromised barrier than normal skin, implying a higher risk of intoxication and hypersensitization by environmental agents through diseased skin with impaired barrier function.

Acetone↗

Needle aspiration and endodiathermy treatment of epithelial inclusion cyst of the iris.

PURPOSE: To report a case of recurrent epithelial inclusion cyst of the iris treated with needle aspiration and endodiathermy. METHODS: Case report. A 27-year-old man with a history of congenital cataracts, congenital nystagmus, cataract surgery in each eye at 3 years of age, and a long-standing iris epithelial cyst presented with decreased vision of 20/400 in the better seeing left eye. The reduced vision was diagnosed secondary to growth of the iris inclusion cyst over the pupil. RESULTS: The iris cyst, which occluded the chamber angle and pupil, was treated with aspiration, separation of the cyst wall from the cornea, and endodiathermy. Twelve months after cyst surgery, no evidence existed of epithelial cyst regrowth. The visual function was significantly improved, although Snellen visual acuity was unchanged at 20/400. CONCLUSION: The minimal invasiveness of needle aspiration and diathermy can result in a satisfactory outcome without undertaking more extensive and invasive surgical treatments for epithelial inclusion cysts of the anterior chamber.

Adult↗

Evidence-based recommendations for the diagnosis and treatment of neovascular glaucoma.

PURPOSE: To succinctly update information on the pathogenesis, etiology, diagnosis, and treatment of neovascular glaucoma based on a systematic review of available literature and to provide summary recommendations rated for their importance to clinical outcome. CLINICAL RELEVANCE: Neovascular glaucoma is a devastating ocular disease that often results in loss of vision. The current standard of care includes retinal ablation and control of increased intraocular pressure with medical and surgical therapy. LITERATURE REVIEW METHODOLOGY: The authors conducted a MEDLINE literature search of articles published in English from 1966 to the present. Each article reviewed was rated as to the strength of evidence it provided, and summary ratings for the strength of evidence supporting clinical recommendations were generated. RESULTS: Level A (most important to patient outcome) recommendations for the diagnosis of neovascular glaucoma include a high index of suspicion, a full ocular examination including undilated gonioscopy, and pupil examination. In regard to treatment, Level A recommendations include treatment of the underlying disease origin, complete panretinal photocoagulation (if retinal ischemia is a factor), and medical control of both elevated intraocular pressure and inflammation. Level B recommendations (moderately important to patient outcome) encompass glaucoma surgery to control intraocular pressure when medical therapy is unsuccessful, although the ideal surgical procedure is unknown. Currently, trabeculectomy with antimetabolite therapy, aqueous shunt implants, and diode laser cyclophotocoagulation are the preferred surgical treatment options. CONCLUSIONS: The current literature on neovascular glaucoma has few articles that provide strong evidence in support of therapy recommendations (level I). Future research studies are needed to address areas in which the current evidence is moderately strong (level II) or weak, consisting only of a consensus of expert opinion (level III). Whenever practicable, these studies should be prospective, randomized clinical trials.

Antimetabolites↗

The adsorption of Congo red and vacuum pump oil by rice hull ash.

Rice hull ash (RHA) of large surface area was obtained by acid wash and then calcination at 600 degrees C for 4 h. The white ash was then mixed with kaolin and starch to make pellet adsorbents with reasonable strength to be utilized in a packed column. Both ash and pellet samples showed good adsorption capacities toward the organic substances in wastewater. Furthermore, the surface nature of the white ash and pellet adsorbent could be modified through either hydration or esterification reactions. Corresponding changes in silanol concentrations were successfully correlated to changes in adsorption capacity toward either Congo red or vacuum pump oil molecules.

Adsorption↗

Chlamydia pneumoniae and multiple sclerosis: no significant association.

The cause of multiple sclerosis (MS) is unknown. Despite indications from epidemiological and identical-twin studies that MS is infectious, no virus or other infectious agent has been tightly linked to disease. The isolation of Chlamydia pneumoniae from the cerebrospinal fluid (CSF) of MS patients and the detection of both Chlamydia-specific DNA and antibody in MS CSF have been reported. Other analyses of brain and CSF have shown no significant difference in C. pneumoniae-specific DNA or antibody between MS and control subjects. Recent work has revealed intrathecal production of C. pneumoniae-specific IgG in only 24% of MS patients compared with 5% of control patients. More importantly, the major CSF oligoclonal bands from MS patients did not react to C. pneumoniae.

Adult↗

Angiotensin-converting enzyme gene insertion/deletion, not bradykinin B2 receptor -58T/C gene polymorphism, associated with angiotensin-converting enzyme inhibitor-related cough in Chinese female patients with non-insulin-dependent diabetes mellitus.

To investigate the genetic susceptibility associated with cough related to angiotensin-converting enzyme inhibitor (ACEI) therapy in patients with type 2 diabetes, 189 non-insulin-dependent diabetes mellitus (NIDDM) patients with proteinuria or hypertension treated with perindopril were studied. Cough was considered to be present if the patients had been bothered by a cough during treatment and if they had had related symptoms for at least 2 weeks without an identifiable cause. Polymerase chain reaction (PCR) coupled with single-strand conformation polymorphism (SSCP) was used to detect polymorphisms of ACE and bradykinin B2-receptor genes. After 8 weeks of treatment, 49.2% (93 of 189) of our NIDDM patients were found to be suffering from ACEI-related cough. ACEI-related cough was mainly associated with female patients, with 71.7% (76 of 106) of female and only 20.5% (17 of 83) of male patients experiencing cough after ACEI treatment. There was a significant association of ACE II genotype with ACEI-related cough. The genotype frequencies were 58.2% for II, 47.8% for ID, and 16.7% for DD in patients with ACEI-associated cough and 41.8% for II, 52.2% for ID, and 83.3% for DD in subjects without ACEI-associated cough (chi(2) = 10.268; df = 2, P =.006). As female patients made up the majority of the subjects suffering from ACEI-related cough, we further analyzed the association of ACE I/D genotype with ACEI-related cough separately by sex. Male patients with ACEI-related cough were not associated with ACE I/D genotype distribution, while female patients were strongly associated with ACE I/D genotype polymorphism (chi(2) = 16.12; df = 2; P <.001). There was no association between the bradykinin B2 receptor gene -58T/C polymorphism with ACEI-related cough. In conclusion, our results indicate that Chinese diabetic female subjects are susceptible to ACEI-related cough, and this susceptibility may be genetically predetermined.

Angiotensin-Converting Enzyme Inhibitors↗

Refractive change after dorzolamide use in patients with primary open-angle glaucoma and ocular hypertension.

The purpose of this study was to evaluate refractive and anterior chamber depth changes after short-term dorzolamide use in patients with primary open-angle glaucoma (POAG) and ocular hypertension (OH). This study was prospective and non-comparative and included 34 patients. Baseline refraction and anterior chamber depth were compared to the refraction and anterior chamber depth 14 days after commencing dorzolamide to determine if refraction or anterior chamber depth had been affected. Before dorzolamide use, the mean refractive error was -0.88 +/- 3.53 D (+/-SD). The mean refractive error was -0.94 +/- 3.65 D (+/-SD) two hours post-dose after 14 days of dorzolamide use, which was not significantly different (P = 0.50). The mean pre-treatment anterior chamber depth was 3.088 +/- 0.385 mm (+/-SD), which did not differ significantly from the post-treatment anterior chamber depth mean of 3.092 +/- 0.389 mm (+/-SD) (P = 0.88). The results of the study show that refraction and anterior chamber depth are not significantly altered by short-term dorzolamide use in patients with POAG and OH with no history of previous dorzolamide use.

Adolescent↗

Latanoprost-induced iris heterochromia and open-angle glaucoma: a clinicopathologic report.

PURPOSE: To report the histopathologic and immunohistochemical findings from the iridectomy specimen of a patient with acquired unilateral iris heterochromia due to latanoprost. PATIENT AND METHODS: A 45-year-old woman with open-angle glaucoma and unilateral iris heterochromia was evaluated for uncontrolled intraocular pressure increase. Subsequently, the patient underwent trabeculectomy with mitomycin C and an iridectomy specimen was obtained for analysis. RESULTS: The histopathologic analysis of the iridectomy specimen did not reveal any nuclear atypia, nuclear crowding, or mitotic figures. Immunohistochemical studies showed that the iris melanocytes were negative for HMB45 and S-100, and weakly positive for Melan A. CONCLUSION: Latanoprost-associated iris color change may exhibit a diffuse, uniform, dark velvet-brown appearance, thereby simulating diffuse iris melanoma. Histopathologic and immunohistochemical analysis confirmed the benign characteristics of the affected iris melanocytes.

Antihypertensive Agents↗

Epidermal growth factor induces Egr-1 promoter activity in hepatocytes in vitro and in vivo.

Early growth response-1 (Egr-1) is a transcription factor that couples short-term changes in the extracellular milieu to long-term changes in gene expression. Under in vitro conditions, the Egr-1 gene has been shown to respond to many extracellular signals. In most cases, these findings have not been extended to the in vivo setting. The goal of the present study was to explore the role of epidermal growth factor (EGF) in mediating Egr-1 expression in hepatocytes under both in vitro and in vivo conditions. In HepG2 cells, Egr-1 protein and mRNA were upregulated in the presence of EGF. In stable transfections of HepG2 cells, a 1,200-bp Egr-1 promoter contained information for EGF response via a protein kinase C-independent, mitogen-activated protein kinase-dependent signaling pathway. A promoter region containing the two most proximal serum response elements was sufficient to transduce the EGF signal. In transgenic mice that carry the Egr-1 promoter coupled to the LacZ reporter gene, systemic delivery of EGF by intraperitoneal injection resulted in an induction of the endogenous Egr-1 gene and the Egr-1-lacZ transgene in hepatocytes. Together, these results suggest that the 1,200-bp promoter contains information for EGF response in hepatocytes both in vitro and in intact animals.

Animals↗