Biomedical subjects

M H Tsai

Publications and source records attributed to M H Tsai.

At least 19 recordsLinked to original sources

PubMed2004

Comparison of the severity of illness scoring systems for critically ill cirrhotic patients with renal failure.

BACKGROUND: Mortality rates of cirrhotic patients with renal failure admitted to the medical intensive care unit (ICU) are high. End-stage liver disease is frequently complicated by disturbances of renal function. This investigation is aimed to compare the predicting ability of acute physiology, age, chronic health evaluation II and III (APACHE II and III), sequential organ failure assessment (SOFA), and Child-Pugh scoring systems, obtained on the first day of ICU admission, for hospital mortality in critically ill cirrhotic patients with renal failure. METHODS: Sixty-seven patients with liver cirrhosis and renal failure were admitted to ICU from April 2001-March 2002. Information considered necessary for computing the Child-Pugh, SOFA, APACHE II and APACHE III score on the first day of ICU admission was prospectively collected. RESULTS: The overall hospital mortality rate was 86.6%. Liver disease was most commonly attributed to hepatitis B viral infection. The development of renal failure was associated with a history of gastrointestinal bleeding. Goodness-of-fit was good for SOFA, APACHE II and APACHE III scores. The APACHE III and SOFA models reported good areas under receiver operating characteristic curve (0.878 +/- 0.050 and 0.868 +/- 0.051, respectively). CONCLUSION: Renal failure is common in critically ill patients with cirrhosis. The prognosis for cirrhotic patients with renal failure is poor. APACHE III and SOFA showed excellent discrimination power in this group of patients. They are superior to APACHE II and Child-Pugh scores in this homogenous group of patients.

APACHE↗

PubMed2003

Anticardiolipin antibodies in various diseases in Taiwan: a retrospective analysis.

The goals of this study are to determine the frequency of anticardiolipin antibodies (ACA) in patients with various diseases and to evaluate the clinical significance of ACA in Taiwan. We collected 690 patients from ACA laboratory records. They were divided into eight groups in order to compare ACA percentages. Positive rates of ACA in different disease groups were below 20%, except for 38.2% in autoimmune diseases with vascular thrombosis. Compared with old stroke, the ACA positivity in young stroke was not significantly different (P = 0.482). The positive percentage of lupus anticoagulant (LA) (2.86%) was lower than that of ACA (15.66%) in young stroke (P = 0.015). Among patients with pregnancy loss or prematurity, the ACA positivity in lupus patients (44.44%) was higher than without lupus (9.76%; P = 0.01). The prevalence of ACA is higher in patients with vascular thrombosis complicated by autoimmune diseases than with thrombosis alone in Taiwan. Young and old stroke do not differ in ACA positivity. Moreover, ACA is more prevalent than LA for young stroke related coagulation. The ACA positivity for pregnancy loss or prematurity is very low in Taiwan. In summary, this is the first report on the frequency of ACA and other coagulation factors in various diseases in Taiwan.

Adolescent↗

PubMed2002

Detection of recurrent nasopharyngeal carcinomas with positron emission tomography using 18-fluoro-2-deoxyglucose in patients with indeterminate magnetic resonance imaging findings after radiotherapy.

PURPOSE: The aim of this study was to evaluate the effectiveness of positron emission tomography (PET) using 18-fluoro-2-deoxyglucose (FDG) to detect recurrent nasopharyngeal carcinomas (NPC) when magnetic resonance imaging (MRI) findings are indeterminate. PATIENTS AND METHODS: After radiotherapy, 28 NPC patients with indeterminate MRI findings were included. MRI, FDG-PET, and biopsy were performed at least 4 months after radiotherapy and within 1 week. The final results were based on histopathologic findings and a clinical follow-up of at least 6 months. RESULTS: For detecting recurrent NPC in indeterminate MRI findings, the sensitivity, specificity and accuracy of FDG-PET were 100.0%, 92.9% and 96.4%, respectively. CONCLUSIONS: Based on these results, we can recommend FDG-PET for detecting recurrent NPC when MRI findings are indeterminate.

Adult↗

PubMed2002

Detection of cervical lymph node metastases in nasopharyngeal carcinomas: comparison between technetium-99m methoxyisobutylisonitrile single photon emission computed tomography and magnetic resonance imaging.

We compared the effectiveness technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) of head and neck in evaluating cervical lymph node (LN) metastasis in nasopharyngeal carcinomas (NPC). Forty NPC patients with cervical LN metastases confirmed histopathologically underwent Te-99m MIBI SPECT and MRI of the head and neck to evaluate cervical LN metastases. For 16 LN lesions with discordant results between Tc-99m MIBI SPECT and MRI, Tc-99m MIBI SPECT could correctly detect 1 metastatic and 10 benign LN lesions as well as MRI could correctly detect 3 metastatic and 2 benign LN lesions. Agreement positive results of Tc-99m MIBI SPECT and MRI could correctly detect all of the remaining 24 metastatic LN lesions. Tc-99m MIBI SPECT has a better specificity but a lower sensitivity for detecting cervical LN metastases in NPC when compared with MRI. The combined use of Tc-99m MIBI SPECT and MRI could increase the accuracy compared with the single use of either Te-99m MIBI SPECT or MRI to detect cervical LN metastases in NPC.

Adult↗

PubMed2001

Fetal fetuin selectively induces apoptosis in cancer cell lines and shows anti-cancer activity in tumor animal models.

An apoptosis-inducing protein with molecular weight of 60 kDa has been purified from fetal bovine serum. The N-terminal amino acid sequence of this protein (e.g. I-P-L-D-P-V-A-G-Y-K) reveals that it is bovine fetuin, a fetal protein functioning to control embryogenesis. The apoptosis-inducing activity of fetuin is totally dependent on zinc. Depletion of zinc ion from fetuin or substitution of zinc ion by barium ion completely abolished the apoptosis-inducing activity of fetuin. Interestingly, while the fetuin isolated from fetal serum selectively induces apoptosis in cancer without affecting normal cells, the fetuin isolated from mature serum is completely inactive. This suggests that the biological activity of fetuin is under developmental regulation. In vivo, tumor animal model studies showed that fetuin enhanced survival by up to 141% in P388 leukemia animal model in mice. Fetuin was also found to inhibit prostate cancer formation in a PC-3 prostate cancer model in mice.

Animals↗

PubMed2001

X-ray absorption studies of carbon-related materials.

X-ray absorption near-edge structure (XANES) measurements have been performed on nitrogen-doped diamond films with three different dopant concentrations and iron-layer-stabilized carbon nanotube (CNT) structures with various diameters at the C K-absorption edge using the sample drain current mode. The C K-edge XANES spectra of these N-doped diamond films resemble that of the undoped diamond regardless of the dopant concentration, which suggest that the overall bonding configuration of the C atom is unaltered. N dopants are found to reduce the intensities of both the sp2- and sp3-bond-derived resonance features in the XANES spectra. On the other hand, the C K-edge XANES spectra of CNTs indicate that the intensities of the pi* and sigma* bands and the interlayer-state features vary with the diameter of the CNT. This phenomenon may be caused by the Fe-layer-catalysed bending of the graphite sheet and the interaction between C and Fe atoms.

Journal Article↗

PubMed2001

Schistosoma mansoni: molecular characterization of a tegumental Ca-ATPase (SMA3).

A cDNA encoding a Ca-ATPase homologue, designated SMA3, was isolated from an adult cDNA library of Schistosoma mansoni. The full-length cloned DNA contains a 3105-bp open reading frame that potentially encodes a 1035-amino-acid protein with a M(r) of 113,729 and a pl of 6.48. Homology searches for SMA3 reveal high sequence identity with a variety of Ca-ATPases from evolutionarily diverse organisms. SMA3 is predicted to contain 10 transmembrane regions typical of this protein family as well as other conserved domains, such as the phosphorylation site and FITC binding domain. The greatest sequence identity (40-50%) is found to those Ca-ATPases belonging to the secretory pathway subclass. Identification of the 5' end of the SMA3 cDNA by RACE analysis reveals the presence of a 36-base spliced leader RNA, suggesting that the SMA3 pre-mRNA is processed by trans-splicing. Northern analysis reveals a single dominant transcript of 5 kb in adult RNA preparations. Antibodies raised against an amino terminal peptide detect the protein in the adult tegument, suggesting that SMA3 functions to help control Ca homeostasis within the tegument and may play a role in signal transduction at the host parasite interface.

Amino Acid Sequence↗

PubMed2001

Octreotide potentiates PKC-dependent vasoconstrictors in portal-hypertensive and control rats.

BACKGROUND & AIMS: The effect of octreotide on vascular tone in the superior mesenteric artery (SMA) was studied in portal-hypertensive (portal vein-ligated) and sham-operated rats. METHODS: In vitro-perfused SMA vascular beds were tested for the cumulative dose-response to octreotide at baseline conditions and after preconstriction with different vasoconstrictors (alpha1-agonist methoxamine, endothelin [ET-1], phorbol ester [PdBu], and potassium chloride [KCl]). RESULTS: Octreotide did not affect baseline perfusion pressures (without preconstriction). alpha1-Adrenergic-, ET-1-, and PdBu-, but not KCl-, induced vasoconstriction was significantly potentiated by octreotide. This effect was dose-dependent and not different in portal vein-ligated and sham rats. Amplification of alpha1-adrenergic vasoconstriction by octreotide was significantly enhanced by nitric oxide inhibition (N(W)-nitro-L-arginine, 10(-4) mol/L) as well as by removal of the endothelium, and was completely suppressed by inhibition of protein kinase C (calphostin C, 1 micromol/L), phospholipase A2 (quinacrine, 5 micromol/L), and cyclooxygenase (indomethacin, 20 micromol/L). CONCLUSIONS: Not directly, but in the presence of vasoconstrictors involving activation of protein kinase C, octreotide exerts a local vasoconstrictive effect on vascular smooth muscle of SMA. This potentiation is equipotent in portal vein-ligated and sham rats, immediate in onset, and mediated via phospholipase A2 and cyclooxygenase-derived prostanoids. This indicates that in preprandial conditions octreotide enhances the vasoconstrictive effect of dependent vasoconstrictors.

Adrenergic alpha-Agonists↗

PubMed2001

Dynamics of changes in micronucleus frequencies in subjects post cessation of chronic low-dose radiation exposure.

To assess DNA damage remaining in peripheral lymphocytes, 48 individuals were evaluated twice for lymphocyte micronucleus frequencies by the cytokinesis-blocking cytochalasin B (CBMN) analysis post relocation from radio-contaminated apartments after various periods of time. The frequencies of CBMN at the first evaluation were significantly higher than those at the second examination (Chang et al., 1999c). These individuals were categorized into three groups: those with cumulative exposure of >300 mSv (defined as high exposure, HDose), those with 100-300 mSv (MDose) and those with <100 mSv (LDose). Using the Poisson mixed-effect model (Little et al., 1996), the estimated mean CBMN frequencies ( per thousand) for individuals in HDose, MDose and LDose exposure categories when they had only recently relocated were 21.8, 17.6 and 15.4, respectively. The estimated mean duration post relocation for the CBMN frequencies of these individuals to reduce to 10.2, the second CBMN frequency, on average, was 47.5, 37.2 and 28.3 months in the three exposure groups, respectively. The rates of change in CBMN frequencies were shown to be significantly higher in the HDose group than in the MDose and LDose groups. The results suggested a characteristic dose-dependent decline in the CBMN frequencies in the exposed population post cessation of chronic low-dose ionizing radiation exposure.

Adolescent↗

PubMed2001

Determination of 8-oxoguanine in individual cell nucleus of gamma-irradiated mammalian cells.

8-Oxoguanine, through its ability to mispair bases other than cytosine, is assumed to be one of the most potent premutagenic lesions in nuclear DNA damaged by reactive oxygen radicals. In this study, we examine whether the presence of residual 8-oxoguanine can be detected in mammalian cells after exposure to ionizing radiation. MOLT-4 human leukemia cells and CHO-K1 Chinese hamster cells were acutely irradiated in vitro with 0, 0.2, 0.4, 0.6 and 1.0 Gy gamma radiation at room temperature. The amounts of 8-oxoguanine and total DNA in the cell nucleus were detected by fluorescein-isothiocyanate (FITC)-labeled avidin, which binds specifically and directly to 8-oxoguanine, and propidium iodide, respectively. The intensity ratios between these two fluorescent dyes were then taken as indices to measure the content of 8-oxoguanine within individual cells. We found an apparent dose-dependent increase in the amount of 8-oxoguanine accumulated in cells of both lines. Moreover, the content of 8-oxoguanine decreased from 2 to 20 h after irradiation in CHO-K1 cells, which may reflect the time-dependent repair processes at the 8-oxoguanine lesions. This novel approach may provide a sensitive tool for in situ measurement of 8-oxoguanine in cells or even in the human body after exposure to ionizing radiation.

Animals↗

PubMed2001

Effect of platelet activating factor and butyrate on the expression of interleukin-2 receptor alpha in nasopharyngeal carcinoma cells.

Serum level of soluble interleukin-2 receptor alpha (sIL-2Ralpha) has been shown to correlate with disease progression and prognosis of cancer patients. However, the available information about the source and the pathophysiological regulation of IL-2Ralpha in cancer cells is limited. This study addressed the questions of prognostic value and the source of sIL-2Ralpha in patients with nasopharyngeal carcinoma (NPC). Biological regulation of IL-2Ralpha was characterized in NPC cell lines. Serum sIL-2Ralpha levels of 113 NPC patients were measured by enzyme-linked immunosorbent assay (ELISA). Levels of sIL-2Ralpha in NPC patients were significantly higher than that in the healthy controls, and sIL-2Ralpha levels were correlated with disease progression and patient survival. IL-2Ralpha was identified in cancer cells by immunocytochemistry. In vitro, IL-2Ralpha expression was markedly increased following treatment with platelet activating factor and/or n-sodium butyrate. Increased secretion of IL-2Ralpha was also detected in the culture media. The secreted IL-2Ralpha could functionally bind IL-2. These results indicate that elevated sIL-2Ralpha was often detected in patients with advanced NPC. The elevated sIL-2Ralpha could be shed from NPC cells by a yet to be determined mechanism and IL-2Ralpha expression in NPC cells could be upregulated by platelet activating factor and butyrate.

Adult↗

PubMed2001

Acute jejunogastric intussusception: report of five cases.

The purpose of this study was to investigate the clinical manifestations and diagnosis of patients with acute jejunogastric intussusception. From May 1986 to June 1999, a total of 5 men (54-76 years old) were collected. Their initial presentations included epigastralgia (4), coffee-ground vomitus (3), frank hematemesis (1), and tarry stool (1). All patients had gastric surgeries 10-30 years previously. Radiograph of the abdomen showed a soft tissue density at the left upper quadrant in one patient. Panendoscopies were done in 4 patients. An obstructed efferent loop with a distended hyperemic small bowel protruding into the remnant of stomach was found in 3 cases, gangrenous change of the bowel wall in one of them. Stump cancer was diagnosed initially in the other patient. Barium study (3/5) showed efferent loop obstruction with "coil spring sing" and a central defect in the stomach. All 5 patients underwent segmental resection and end-to-end anastomosis between the 2nd to 6th hospital day. Operative findings were type II jejunogastric intussusception with retrograde invagination of a segment of efferent loop (30-100 cm in length) into the stomach. In conclusion, acute jejunogastric intussusception is an emergent condition. Early and accurate diagnosis is important. A high susception must be kept in mind in patients having a history of gastrojejunostomy with severe abdominal pain or upper gastrointestinal bleeding.

Acute Disease↗

PubMed2001

Anaphylaxis after propofol infusion for Port-A-Cath insertion in a 35-year old man.

Anaphylaxis to propofol is rare and has not been previously reported in Asia. We describe a 35-year-old man with nasopharyngeal carcinoma who developed acute respiratory distress and hypotension after propofol infusion for parenteral anesthesia for Port-A-Cath insertion. Chest roentgenogram showed bilateral diffuse alveolar infiltrates. Respiratory failure ensued, and vocal cord swelling was found during endotracheal intubation. Hemodynamic data included a low cardiac index, a low systemic vascular resistance, and a high pulmonary vascular resistance. His condition and the shadows on the chest roentgenogram improved quickly after fluid challenge and the use of vasopressors, antihistamine, and intravenous steroids. Early awareness and appropriate management are necessary to prevent a fatal outcome in patients with propofol anaphylaxis.

Adult↗

PubMed2001

Choroidal masses: a fourteen-year analysis.

BACKGROUND: Choroidal masses present much diversification in clinical features and incidence. The purpose of this study is to investigate the epidemiological and clinicopathological manifestations of different choroidal tumors in order to tabulate appropriate diagnostic approaches. METHODS: A retrospective analysis of patients with choroidal masses was conducted, the analysis being based upon the review of our medical records from January 1986 to December 1999 inclusively. A definite diagnosis of choroidal mass was confirmed by at least two experienced ophthalmologists. For patients who were enrolled in this study, an ophthalmic examination was conducted and medical history was recorded. Some ancillary tests, such as indirect ophthalmoscopy, ultrasonography, fluorescein angiography, computed tomography, and magnetic resonance imaging, were used to support the accuracy of our diagnoses. RESULTS: A total of 149 patients were enrolled in this study, of which 103 cases were excluded due to a loss of follow-up or incomplete medical records. Forty-six patients (51 eyes) included 12 cases (26%) of malignant metastases, 10 cases (22%) of hemangiomas, 2 cases (4%) of osteomas, 5 cases (11%) of melanocytomas, 8 cases (17%) of melanomas, and 9 cases (20%) of other melanocytic lesions. The male to female ratio was 21:25. The average length of follow-up was 20.5 months, and the average age of these patients was 42.8 years. Presenting with varied clinical incidence and pictures, each category of choroidal mass was investigated thoroughly. CONCLUSION: With more clinical experience and a better understanding of choroidal masses, we are able to propose an early differential diagnosis and therapeutic approach to the effective management of them in order to minimize ocular morbidity and improve patients' survival and quality of life.

Adult↗

PubMed2001

Results of 12-year clinical study of giant retinal tear.

BACKGROUND: To evaluate the surgical results of scleral buckling alone on eyes with retinal detachment with giant retinal tears of less than 120 degrees, without inverted flap or proliferative vitreoretinopathy, and vitrectomy combined with scleral buckling with or without intraoperative usage of perfluorocarbon liquid (PFCL) in complicated cases. METHODS: Retrospectively, we reviewed giant retinal tear cases treated at Chang Gung Memorial Hospital, Kaohsiung, Taiwan between January 1, 1989 and August 31,2000. The surgical techniques consisted of standard three-port pars plana vitrectomy combined with scleral buckling in complicated cases, PFCL used intraoperatively in later cases, and scleral buckling alone in minor cases. RESULTS: A total of 47 consecutive eyes with giant retinal tears with retinal detachment in 45 patients with no previous history of ocular penetrating injury or vitreoretinal operations were enrolled in this study. The follow-up period was at least three months for all patients. Thirty-four eyes (72.3%) had giant retinal tears of less than 180 degrees, 12 eyes (25.5%) had tears between 180 degrees and 270 degrees, and one eye had two giant retinal tears. Scleral buckling combined with vitrectomy was performed in 36 complicated eyes (76.6%), PFCL was used intraoperatively later in 24 eyes, and scleral buckling was used alone in 11 minor cases (23.4%). Thirty eyes (63.8%) gained reattachment after the first surgery. Altogether, the retinas of 38 of 47 eyes (80.9%) remained attached at the last follow-up examination. CONCLUSION: In minor cases of giant retinal tear, scleral buckling alone without vitrectomy may be considered the primary surgical procedure. In complicated cases, using PFCL intraoperatively not only affords many advantages during surgery, but also raises the retinal reattachment rate.

Adolescent↗

PubMed2001

Methimazole-induced pulmonary hemorrhage associated with antimyeloperoxidase-antineutrophil cytoplasmic antibody: a case report.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis has been recently recognized in Graves' disease patients treated with antithyroid drugs. We describe the case of an 18-year-old girl who developed antimyeloperoxidase ANCA (MPO-ANCA)-positive vasculitis manifesting as a skin lesion and hemoptysis with hypoxic respiratory failure after taking methimazole. An open lung biopsy was consistent with acute capillaritis. Both skin and sural nerve biopsy showed lymphocytic vasculitis. Administration of steroid and plasmapheresis produced a good clinical response.

Adolescent↗

PubMed2000

Free colon transfer for pharyngo-oesophageal reconstruction.

This report describes free transfer of transverse colon for reconstruction of the hypopharynx and cervical oesophagus. The transverse colon based on the middle colic vessels was used in three patients following laryngo-pharyngo-oesophagectomy for hypopharyngeal squamous carcinoma. There were no flap failures or intra-abdominal complications. Solid diet was well tolerated. Transverse colon is easy to harvest, has a long vascular pedicle, wide diameter and good ischaemic tolerance. Contrast studies showed it to be a wide bore passive conduit. Compared with currently available options these features may allow better outcome in pharyngo-oesophageal reconstruction and warrant further evaluation.

Adult↗

PubMed2000

Virus infection in patients with histiocytic necrotizing lymphadenitis in Taiwan. Detection of Epstein-Barr virus, type I human T-cell lymphotropic virus, and parvovirus B19.

The relationship of Epstein-Barr virus (EBV), type I human T-cell lymphotropic virus (HTLV-I), and parvovirus B19 to histiocytic necrotizing lymphadenitis was studied prospectively in 10 Taiwanese patients using materials obtained by fine-needle aspiration and lymph node biopsy. The presence of EBV was detected by in situ hybridization for EBV-encoded RNA expression. Immunocytochemistry was used to detect virus-encoded protein for EBV and parvovirus B19. DNA in situ hybridization and polymerase chain reaction were performed to determine the existence of HTLV-I provirus. Expressions of EBV-encoded RNA and Fas ligand were detected in all cases. Expression of EBV-encoded protein was identified in only 1 case. Neither HTLV-I nor parvovirus B19 was detected in any case.

Adolescent↗