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Tsai SJ, Hwang JP, Yang CH, Liu KM, Lirng JF. Inappropriate sexual behaviors in dementia: a preliminary report. Alzheimer Dis Assoc Disord 1999; 13:60-2. [PMID: 10192644 DOI: 10.1097/00002093-199903000-00009] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We investigated types of inappropriate sexual behavior (ISB) and patient characteristics in geriatric patients with dementia. The study group consisted of 133 consecutive geropsychiatric demented patients admitted to our ward. All patients underwent standardized diagnostic procedures for dementia, and ISB was assessed by a questionnaire completed by patients' caregivers and records during hospitalization. Patients were then subdivided on the basis of the presence or absence of ISB. Of the 133 demented patients, 20 (15.0%) were reported to demonstrate ISB at home or during hospitalization. Patients with ISB had various types of dementia. There were no significant differences in patients with and without ISB in regard to age, age of onset, gender, educational level, or Mini-Mental State Examination scores. ISB is not unusual in dementia patients and can be found in different types of dementia. Medical care providers need to be trained to discuss sexual issues with caregivers and offer ideas and training to help cope with patients with ISB.
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Abstract
OBJECTIVE This study investigated the deaths of patients sixty-five and older on a psychiatric ward to determine the mortality rate, the characteristics of illness, and the cause of death. METHODS We analyzed the case record of patients sixty-five and older who had died during hospitalization on a psychiatric ward during a seventeen-year period. Case data was collected by review of chart records. RESULTS The mortality rate in the patients sixty-five and older was 18/1208 (1.5%). Eight of these eighteen patients died of pneumonia. Mortality in the acutely ill geropsychiatric inpatients was difficult to predict. Age, sex, and diagnosis did not predict mortality. CONCLUSIONS To reduce mortality, especially in male veterans, management of geropsychiatric patients should include early recognition of pneumonia symptoms, especially for patients with history of pulmonary disease.
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Lin AT, Chen KK, Yang CH, Chang LS. Effects of outlet obstruction and its reversal on mitochondrial enzyme activity in rabbit urinary bladders. J Urol 1998; 160:2258-62. [PMID: 9817380 DOI: 10.1097/00005392-199812010-00096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE This study investigated the effects of outlet obstruction and its reversal on mitochondrial enzyme activity in the rabbit urinary bladder. MATERIALS AND METHODS We induced mild bladder outlet obstruction in male New Zealand White rabbits. Following two weeks of obstruction, one group of animals (n = 6) was sacrificed, while outlet obstruction was relieved in three additional groups of animals, which were sacrificed one (n = 5), two (n = 5) and four (n = 5) weeks after relieving the obstruction. Seven sham operated rabbits served as controls. We extracted mitochondria from fresh detrusor and assayed activities of key mitochondrial enzymes in the citric acid cycle, citrate synthase and malate dehydrogenase, as well as those in the electron transport chain, succinate cytochrome c reductase, NADH-cytochrome c reductase and cytochrome c oxidase. With high performance liquid chromatography (HPLC) we determined the tissue content of phosphocreatine and the adenine nucleotides (ATP, ADP and AMP), which was used for calculating energy charge. Responses of detrusor strips to 500 microM bethanechol and 120 mM KCl provided the assessment of detrusor contractility. RESULTS Contractile response of the detrusor strips to bethanechol stimulation was significantly reduced by outlet obstruction, nevertheless, it recovered gradually toward the control level after the relief of outlet obstruction. Outlet obstruction reduced the detrusor content of phosphocreatine, ATP and energy charge. After relieving the obstruction, however, these recovered gradually, reaching control levels 4 weeks later. The activities of all assayed enzymes were reduced by two weeks of outlet obstruction. Relieving the obstruction restored enzyme activity gradually but at different rates for different enzymes. Activities of the citric acid cycle enzymes citrate synthase and malate dehydrogenase recovered and were similar to control levels four weeks after relief of the obstruction. Of the enzymes in the electron transport chain, NADH cytochrome reductase activity recovered most quickly by one week after relief of the obstruction. The activity of cytochrome c oxidase improved more slowly, but 4 weeks after relieving the obstruction it, also, was restored and was similar to the control level. Succinate cytochrome reductase activity remained lower than the control over the entire four weeks of recovery. CONCLUSIONS The close association between mitochondrial enzyme activity, energy metabolism and contractility of the detrusor indicates the important role of mitochondrial enzyme damage in decreasing energy production and impairing contractile function of the urinary bladders following outlet obstruction. Our findings also show that various mitochondrial enzymes exhibit different susceptibilities and reversibilities to pathological stress.
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Lu PP, Liu HP, Shyr MH, Ho AC, Wang YL, Tan PP, Yang CH. Softened endothracheal tube reduces the incidence and severity of epistaxis following nasotracheal intubation. ACTA ANAESTHESIOLOGICA SINICA 1998; 36:193-7. [PMID: 10399514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND Many complications were reported to be related with nasotracheal intubation. Various chemical or mechanical techniques have been proposed to decrease hemorrhage and trauma associated with nasotracheal intubation but the results remain controversial. We conducted a prospective, randomized, single-blind study to elucidate the effect of an endotracheal tube softened with warm water before use on the incidence and severity of epistaxis following nasotracheal intubation. METHODS Sixty-two healthy, (ASA class I or II) patients scheduled for elective surgery were randomly assigned into two groups. Patients in the treatment group were intubated with a softened endotracheal tube made possible by heating it in warm water while those in the control group were intubated with unsoftened (intact) tube. Epistaxis was evaluated immediately after intubation and its severity was graded as none, mild, moderate and severe. The use of Magill forceps and postoperative nasal morbidity were also recorded. RESULTS The total incidence of epistaxis in the "unsoftened" group was significantly higher than that of "softened" group (76.7% vs. 43.8%, P = 0.0002). The severity of nasal hemorrhage was also significantly lightened in the "softened" group. No technical difficulty was encountered in intubation with a softened endotracheal tube by prewarming. The morbidity referable to nasal intubation, however, did not differ in both groups. CONCLUSIONS In conclusion, our study shows that using an endotracheal tube softened by warm water could reduce the incidence and severity of epistaxis during the act of nasotracheal intubation. It is an effective way and worth a try.
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Yang CH, Ji YY, Yeh M. The kinetics of IL-4 and IFN-gamma gene expression in mice after Trichosansin immunization. Cell Res 1998; 8:295-302. [PMID: 9934537 DOI: 10.1038/cr.1998.29] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Trichosanthin (TCS) is a potent allergen to mice. According to our previous experiments, it could bring out the IgE response to ovabumin (OVA) if TCS was given one day before OVA immunization, while OVA alone could not induce IgE to it. In this work, the kinetics of interleukin 4(IL-4) and interferon gamma(IFN-gamma) gene expression in the mesenteric lymph node (MLN) of TCS-immunized mice was investigated using a semi-quantitative RT-PCR method. It indicated that TCS induced significant IL-4 gene expression and the peaks of IL4 gene expression were on day one after TCS immunization in both primary and secondary response. In contrast, the IFN-gamma gene expression was suppressed. Furthermore, the IL-4 gene expression in the secondary response was lower than that in the primary response. Thus the presence of IgE memory B cells were studied. Results showed that the amount of mature IgE mRNA arose significantly and rapidly one day after TCS restimulation, while in the MLN of the mice primed 30 days before and without boost, it was almost as the same amount of the unimmunized control. These findings suggest the existence of the IgE memory B cells in the mice after the primary TCS immunization.
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Cheng AL, Yeh KH, Fine RL, Chuang SE, Yang CH, Wang LH, Chen DS. Biochemical modulation of doxorubicin by high-dose tamoxifen in the treatment of advanced hepatocellular carcinoma. HEPATO-GASTROENTEROLOGY 1998; 45:1955-60. [PMID: 9951847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
BACKGROUND/AIMS In vitro data have indicated that tamoxifen (> 2.5 uM) significantly enhances the cytotoxic effect of doxorubicin in hepatocellular carcinoma (HCC) cells. This clinical study was conducted to examine whether tamoxifen, at a dose sufficient to result in a plasma concentration of more than 2.5 uM, may improve the therapeutic efficacy of doxorubicin in patients with advanced HCC. METHODOLOGY A prospective phase II study was conducted. Eligible patients had unresectable and non-embolizable HCC, objectively measurable tumors, adequate neogram with absolute granulocyte count > 2,000/mm3 and platelet count > 1 x 10/mm3, total serum bilirubin < 3.0 mg/dl, age > or = 75 year, and a Karnofsky performance status < or = 50%. The treatment included oral tamoxifen 40 mg/m2, q.i.d, Day 1 to 7, and intravenous doxorubicin 60 mg/m2, Day 4, repeated every 3 weeks. RESULTS Between May 1994 and December 1996, a total of 38 patients were enrolled in the study. Thirty-six patients were evaluable for tumor response and treatment-related toxicities. There were 32 men and 4 women, with a median age of 49 years. They received an average of 3.8 (range:1-12) courses of chemotherapy. ECOG (Eastern Cooperative Oncology Group) Grade 3-4 leucopenia and Grade 3-4 thrombocytopenia developed in 27.2% and 12.5% courses given, respectively. Gastrointestinal toxicity was generally mild. Three patients developed symptomatic cardiac toxicity. Twelve patients (33.3%, 95% confidence interval 17-51%) had achieved a partial remission (PR), with a median progression-free survival of 7 months. Median survivals of the responders and non-responders were 10 and 3 months, respectively (p<0.05). The median Karnofsky performance status of the responders improved from 74.0+/-6.3% to a post-chemotherapy value of 93.2+/-4.6% (p<0.05) CONCLUSIONS High dose tamoxifen appears to be an effective biochemical modulator of doxorubicin in the treatment of HCC. Prospective randomized phase III studies comparing doxorubicin alone versus doxorubicin plus high-dose tamoxifen are needed.
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Hwang JP, Tsai SJ, Yang CH, Liu KM, Lirng JF. Hoarding behavior in dementia. A preliminary report. Am J Geriatr Psychiatry 1998; 6:285-9. [PMID: 9793576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Hoarding behavior has been reported in several mental disorders and is occasionally reported by the caregivers of dementia patients. Such behavior may have adverse effects on the patients and increase the burden of the caregivers. This study was conducted to investigate the prevalence of hoarding behavior in patients with dementia and identify the characteristics and psychiatric symptoms associated with it. The sample was 133 dementia patients admitted to a geropsychiatric ward. Of the 133 dementia patients, 30 (22.6%) showed hoarding. Hoarding was found in various types of dementia. Patients with hoarding had a higher prevalence of repetitive behaviors, hyperphagia, and pilfering. Results suggested that hoarding behavior is a common symptom in dementia patients and a complex phenomenon. Better understanding of the underlying pathogenesis may highlight specific pharmacological or behavioral methods for treatment of the behavior.
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Kuo ML, Shen SC, Yang CH, Chuang SE, Cheng AL, Huang TS. Bcl-2 prevents topoisomerase II inhibitor GL331-induced apoptosis is mediated by down-regulation of poly(ADP-ribose)polymerase activity. Oncogene 1998; 17:2225-34. [PMID: 9811453 DOI: 10.1038/sj.onc.1202133] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Poly (ADP-ribose) polymerase (PARP), a nuclear enzyme responsible for DNA strand breaks, has been recently suggested to be crucial for apoptosis induced by a number chemotherapeutic drugs. In this study, we demonstrated that the PARP activity could be evidently elevated with a peak at 6 h when HL-60 cells were treated with a new anticancer drug GL331. Coincident with the peak of PARP activity, an apparent DNA fragmentation and apoptotic morphology were observed in cells treated with GL331. The subsequent apoptotic DNA fragmentation induced by GL331 could be completely blocked by transfecting cells with anti-sense PARP retroviral vector or by treating cells with PARP inhibitor, 3-aminobenzamide (3-AB). This blocking effect thus suggests that activation of PARP was critically involved in GL331-induced apoptosis. The fact that Bcl-2 has been found to antagonize cell death induced by a wide variety of agents, accounts for why we examined whether if Bcl-2 could antagonize GL331 effects. Interestingly, ectopic overexpression of Bcl-2 in either HL-60 or U937 cells caused in resistance towards GL331-elicited DNA fragmentation and cytotoxic effect. Additionally, Bcl-2 also attenuated the poly(ADP-ribosyl)ation of PARP itself as well as Histone H1 at the early period of drug treatment. However, Bcl-2 did not influence the extent of DNA strand breaks induced by GL331 in either control or Bcl-2-overexpressing cells. In addition, analysis of basal PARP activity in control and several Bcl-2 overexpressing clones revealed that Bcl-2 down-regulated PARP activity under the condition without DNA damages. Above findings suggest that poly(ADP-ribosyl)ation of nuclear targets is important for apoptosis induced by DNA-reactive anticancer drugs.
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He X, Harper K, Grantham G, Yang CH, Creamer R. Serological characterization of the 3'-proximal encoded proteins of beet yellows closterovirus. Arch Virol 1998; 143:1349-63. [PMID: 9722879 DOI: 10.1007/s007050050380] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The 3'-proximal open reading frames (ORFs) of beet yellows closterovirus, California isolate (BYV-CA), were sequenced and the expression of the corresponding proteins analyzed. The nucleotide sequence of ORF 5 (coding for p24) was most conserved compared with ORF 7 (coding for p20) and ORF 8 (coding for p21) among the isolates analyzed. Polyclonal antisera were produced to GST fusion proteins of p24, p20, and p21. Accumulation of p24, CP, p20 and p21 was studied in infected Tetragonia expansa plants and Chenopodium quinoa protoplasts. All four proteins were expressed in all tissues (old leaves, young leaves and stems), and most abundantly in young leaves. The subcellular localization of each protein in different tissues showed that compared with p24, CP and p21, p20 accumulated less in transfected protoplasts. Immunogold labeling in sugarbeet with p24 and CP antisera demonstrated co-localization of p24 and CP in vascular petiole tissues. In infectivity neutralization tests, antisera against p24 and CP greatly reduced transmission of BYV by viruliferous aphids compared with viruliferous aphids fed on preimmune serum or antiserum to p21.
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160
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Yuan YR, Xia ZX, Yang CH, Yang BH, Yeh M. A possible hydrolysis mechanism of beta-naphthyl acetate catalyzed by antibodies. Cell Res 1998; 8:219-30. [PMID: 9791735 DOI: 10.1038/cr.1998.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The mechanism of ester hydrolysis has been extensively studied; however, the precise function of active-site residues in promoting catalysis is unclear. We describe here the structural models for the complex of a catalytic antibody Fv fragment with a phosphonate transition-state analogue, constructed by using gene cloning, sequencing and molecular modeling, mainly based on a known X-ray structure of a catalytic antibody. Hydrophobic and electrostatic analyses of the Fv/analog and Fv/substrate interaction suggest the hydrolysis mechanism: Tyr L91 and Tyr H97 play important roles to stabilize the beta-naphthyl group of hapten through pi-stack; His H35 donates a pair of free electrons at the atom NE2 to an active water and let it to be a partial hydroxide, which attacks the carbon atom of the carbonyl group of the substrate. Both His H35 and Arg L96 can form hydrogen bonds and stabilize the anionic tetrahedral intermediate formed during turnover. This mechanism emphasizes that an active water bridge may be formed during hydrolysis process.
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Roy K, Chiao JH, Spengler BA, Tolner B, Yang CH, Biedler JL, Sirotnak FM. Chromosomal localization of the murine RFC-1 gene encoding a folate transporter and its amplification in an antifolate resistant variant overproducing the transporter. CANCER GENETICS AND CYTOGENETICS 1998; 105:29-38. [PMID: 9689927 DOI: 10.1016/s0165-4608(98)00005-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A variant of the L1210 cell (L1210/R83) selected in the presence of the lipophilic antifolate, metoprine, and a concentration of the natural diastereoisomer of 5-formyltetrahydrofolate, lL5CHO-folateH4, suboptimum for growth exhibited a 35-fold increase compared to parental L1210 cells in one-carbon, reduced folate transport. This was evidenced by the increase in Vmax for [3H]MTX (methotrexate) influx and a commensurate increase in the amount of the 46 kilodalton (kDa) transport protein and reduced folate carrier (RFC-1) mRNA. The variant is resistant to lipophilic antifolates, but shows collateral sensitivity to classical folate analogues. Karyotype analysis of L1210/R83 cells revealed the presence of several new chromosome abnormalities. One of these was a large, submetacentric marker chromosome comprising a normal #10 and a longer, abnormally banded arm of uncertain origin which exhibited an interstitial, palely staining, HSR-like segment. The results of Southern and Northern blotting showed that the RFC-1 gene copy number and RNA transcript level were markedly increased (30-35 fold) in L1210/R83 cells. Fluorescence in situ hybridization (FISH) analysis revealed that the HSR-like segment in these cells was the site of amplified RFC-1 genes. Independent revertant subclones, obtained following growth in the absence of selection pressure, showed four- to 12-fold decreases in [3H]MTX influx Vmax and in amount of NHS (N-hydroxysuccinimide)-[3H]MTX affinity labeled one-carbon, reduced folate transporter compared to L1210/R83 cells. RFC-1 gene copy number also decreased, and the mean length of the HSR in these revertants declined 1.6- to 5-fold. Based upon genomic nucleotide sequencing, the RFC-1 gene in the normal mouse genome was localized to chromosome 10 in close association with the alpha 1 (Col18a1) collagen gene at 10B3(locus 41cM). The close association of these genes was confirmed by other data showing that the alpha 1 collagen gene was co-amplified in L1210/R83 cells. These results document the amplification at the site of a putative HSR in an L1210 cell variant of the RFC-1 gene regulating expression of the one-carbon, reduced folate transporter.
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Chou ML, Yang CH. FLD interacts with genes that affect different developmental phase transitions to regulate Arabidopsis shoot development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1998; 15:231-242. [PMID: 9721681 DOI: 10.1046/j.1365-313x.1998.00204.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A new fld mutant allele, fld-2, which significantly delayed flowering, was isolated and characterized in Arabidopsis thaliana. Even under long-day conditions after more than 100 days in the greenhouse, the majority of fld-2 mutant plants had not bolted. In addition, mutant inflorescences produced more than 10 co-florescences that were subtended by a high number of rosette-like leaves before giving rise to flowers. The late-flowering phenotype of the fld-2 mutation could be partially overcome by both vernalization and GA treatment but it was not influenced by 5-azaC treatment. Phenotypic analyses of double mutants indicated that fld-2 is epistatic to early flowering mutants elf1, elf2 and elf3. In addition, fld-2 could enhance vegetative characteristics in embryonic flower 1 (emf1) mutants by causing many small sessile leaves in fld-2 emf1 double mutants. The relief of the terminal flower 1 (tfl1) mutant phenotype in fld-2 tfl1 double mutants, and the enhancement of leafy (lfy) and apetala1 (ap1) mutant phenotypes in fld-2 lfy and fld-2 ap1 double mutants, suggest that FLD is also likely to be involved in the floral transition. Our results strongly suggest that the FLD gene plays a key role in regulating the reproductive competence of the shoot and results in different developmental phase transitions in Arabidopsis.
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Park S, Lee DK, Yang CH. Inhibition of fos-jun-DNA complex formation by dihydroguaiaretic acid and in vitro cytotoxic effects on cancer cells. Cancer Lett 1998; 127:23-8. [PMID: 9619854 DOI: 10.1016/s0304-3835(97)00543-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The effect of dihydroguaiaretic acid (DHGA), isolated from the aryls of Myristica fragrans, on the transcription factor (fos-jun dimer) action was investigated via in vitro assay. DHGA showed an inhibitory effect against the complex formation of the fos-jun dimer and the DNA consensus sequence with an IC50 value of 0.21 micromol. Nordihydroguaiaretic acid (NDGA) and curcumin also inhibited fos-jun dimer action showing IC50 values of 7.9 and 6.9 nmol, respectively. DHGA and NDGA suppressed leukemia, lung cancer and colon cancer in an in vitro bioassay. The in vitro experiment suggested that inhibition of fos-jun-DNA complex formation could be due to the direct interference of fos-jun dimer binding onto the DNA consensus sequence by NDGA and curcumin.
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Yang CH, Murti A, Pfeffer LM. STAT3 complements defects in an interferon-resistant cell line: evidence for an essential role for STAT3 in interferon signaling and biological activities. Proc Natl Acad Sci U S A 1998; 95:5568-72. [PMID: 9576923 PMCID: PMC20418 DOI: 10.1073/pnas.95.10.5568] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
STAT proteins play critical roles in the signal transduction pathways for various cytokines. The type I interferons (IFNalpha/beta) promote the DNA-binding activity of the transcription factors STAT1, STAT2, and STAT3. Although the requirement for STAT1 and STAT2 in IFNalpha/beta signaling and action is well documented, the biological importance of STAT3 to IFN action has not yet been addressed. We found that STAT3 plays a critical role in signal transduction by IFNalpha/beta. A human cell line that is resistant to the antiviral and antiproliferative activities of IFN but is still IFN-responsive by virtue of STAT1 and STAT2 activation was found to be defective in STAT3 activation and in induction of NF-kappaB DNA-binding activity. Expression of STAT3 in these resistant cells complemented these signaling defects and also markedly increased cellular sensitivity to the antiviral and antiproliferative effects of IFN. Because STAT3 is involved in the induction of NF-kappaB DNA-binding activity and in the induction of antiviral and antiproliferative activity, our results place STAT3 as an important upstream element in type I IFN signal transduction and in the induction of biological activities. Therefore, our results indicate that STAT1 and STAT2 are not the only STATs required for the expression of the key biological activities of IFNalpha/beta.
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Choi HJ, Kang SW, Yang CH, Rhee SG, Ryu SE. Crystallization and preliminary X-ray studies of hORF6, a novel human antioxidant enzyme. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 1998; 54:436-7. [PMID: 9761920 DOI: 10.1107/s0907444997011153] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
HORF6 is a member of the novel antioxidant enzyme family found in humans. A recombinant form of hORF6 expressed and purified from E. coli has been crystallized by the hanging-drop method using various PEG's as precipitating agents. HORF6 crystallizes in two different monoclinic space groups, P21 and C2. The P21 crystals have unit-cell dimensions of a = 47.85, b = 75.17, c = 63.30 A and beta = 110.21 degrees and contain two monomers per asymmetric unit, while the C2 crystals have unit-cell dimensions of a = 165.27, b = 95.44, c = 166.44 A and beta = 128.97 degrees and contain more than six monomers per asymmetric unit. The P21 crystals with the smaller unit cell diffract X-rays better and behave well for the X-ray analysis. A native data set from a single crystal of the P21 space group gas been collected to 2.0 A resolution.
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Choi HJ, Kang SW, Yang CH, Rhee SG, Ryu SE. Crystal structure of a novel human peroxidase enzyme at 2.0 A resolution. NATURE STRUCTURAL BIOLOGY 1998; 5:400-6. [PMID: 9587003 DOI: 10.1038/nsb0598-400] [Citation(s) in RCA: 313] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hydrogen peroxide (H2O2) has been implicated recently as an intracellular messenger that affects cellular processes including protein phosphorylation, transcription and apoptosis. A set of novel peroxidases, named peroxiredoxins (Prx), regulate the intracellular concentration of H2O2 by reducing it in the presence of an appropriate electron donor. The crystal structure of a human Prx enzyme, hORF6, reveals that the protein contains two discrete domains and forms a dimer. The N-terminal domain has a thioredoxin fold and the C-terminal domain is used for dimerization. The active site cysteine (Cys 47), which exists as cysteine-sulfenic acid in the crystal, is located at the bottom of a relatively narrow pocket. The positively charged environment surrounding Cys 47 accounts for the peroxidase activity of the enzyme, which contains no redox cofactors.
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Runkel L, Pfeffer L, Lewerenz M, Monneron D, Yang CH, Murti A, Pellegrini S, Goelz S, Uzé G, Mogensen K. Differences in activity between alpha and beta type I interferons explored by mutational analysis. J Biol Chem 1998; 273:8003-8. [PMID: 9525899 DOI: 10.1074/jbc.273.14.8003] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Type I interferon (IFN) subtypes alpha and beta share a common multicomponent, cell surface receptor and elicit a similar range of biological responses, including antiviral, antiproliferative, and immunomodulatory activities. However, alpha and beta IFNs exhibit key differences in several biological properties. For example, IFN-beta, but not IFN-alpha, induces the association of tyrosine-phosphorylated receptor components ifnar1 and ifnar2, and has activity in cells lacking the IFN receptor-associated, Janus kinase tyk2. To define the structural basis for these functional differences we produced human IFN-beta with point mutations and compared them to wild-type IFN-beta in assays that distinguish alpha and beta IFN subtypes. IFN-beta mutants with charged residues (N86K, N86E, or Y92D) introduced at two positions in the C helix lost the ability to induce the association of tyrosine-phosphorylated receptor chains and had reduced activity on tyk2-deficient cells. The combination of negatively charged residues N86E and Y92D (homologous with IFN-alpha8) increased the cross-species activity of the mutant IFN-betas on bovine cells to a level comparable to that of human IFN-alphas. In contrast, point mutations in the AB loop and D helix had no significant effect on these subtype-specific activities. A subset of these latter mutations did, however, reduce activity in a manner analogous to IFN-alpha mutations. The effects of these mutations on IFN-beta activity are discussed in the context of a family of related ligands acting through a common receptor and signaling pathway.
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Lin AM, Yang CH, Chai CY. Striatal dopamine dynamics are altered following an intranigral infusion of iron in adult rats. Free Radic Biol Med 1998; 24:988-93. [PMID: 9607609 DOI: 10.1016/s0891-5849(97)00398-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In vivo electrochemical detection was employed to examine iron-induced oxidative injury on dopamine dynamics in the nigrostriatal system of urethane-anesthetized rats. Seven days after an intranigral infusion of iron, oxidative stress was confirmed by an elevated lipid peroxidation in lesioned substantia nigra (SN). Local application of potassium (K+) evoked dopamine releases from the dopamine-containing nerve terminals in the striatum. Both amplitude and rate of clearance (Tc) of evoked dopamine releases were lower in striatum with lesioned SN; however, the time course parameters of dopamine release in the lesioned group were not different from those of the intact group, indicating a reduction in dopamine clearance. Indeed, iron-induced oxidative stress attenuated the effect of nomifensine, a high-affinity dopamine uptake blocker, on dopamine clearance. In striatum with intact SN, the amplitude and time course parameters of signals by exogenous dopamine were increased and Tc was decreased by nomifensine. In contrast, nomifensine did not significantly alter the dopamine signals of the lesioned group. Taken together, in addition to the increased lipid peroxidation in SN, our in vivo electrochemical data demonstrates that iron-induced oxidative injury attenuates K+-evoked dopamine release and dopamine uptake in the ipsilateral striatum. The diminished nomifensine effect implies a lack of high-affinity dopamine uptake sites.
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Haung MD, Yang CH. EMF genes interact with late-flowering genes to regulate Arabidopsis shoot development. PLANT & CELL PHYSIOLOGY 1998; 39:382-393. [PMID: 9615462 DOI: 10.1093/oxfordjournals.pcp.a029381] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To investigate the genetic mechanisms regulating the transition from vegetative to reproductive phase in Arabidopsis, double mutants between two embryonic flower (emf) and 12 different late-flowering mutants were constructed and analyzed. Double mutants in all combinations displayed the emf phenotypes without forming rosettes during early development; however, clear variations between different double mutants were observed during late development. fwa significantly enhanced the vegetative property of both emf mutants by producing a high number of sessile leaves without any further reproductive growth in emf1 fwa double mutants. It also produced numerous leaf-like flower structures similar to those in leafy ap1 double mutant in emf2 fwa double mutants. Nine late-flowering mutants, ft, fca, ld, fd, fpa, fe, fy, fha, and fve, caused different degrees of increase in the number of sessile leaves, the size of inflorescence, and the number of flowers only in weak emf1 and emf2 mutant alleles background. Two late-flowering mutants, co and gi, however, had no effect on either emf1 and emf2 mutant alleles in double mutants. Our results suggest that FWA function in distinct pathways from both EMF genes to regulate flower competence by activating genes which specify floral meristem identity. CO and GI negatively regulate both EMF genes, whereas the other nine late-flowering genes may interact with EMF genes directly or indirectly to regulate shoot maturation in Arabidopsis.
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Yang CH, Ho GD. Resistance and Susceptibility of Arabidopsis thaliana to Bacterial Wilt Caused by Ralstonia solanacearum. PHYTOPATHOLOGY 1998; 88:330-334. [PMID: 18944956 DOI: 10.1094/phyto.1998.88.4.330] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT Tomato bacterial wilt caused by Ralstonia solanacearum is a model system for studying plant-bacterial interactions, because it is genetically one of the best characterized plant diseases. We demonstrate here that four different strains of R. solanacearum, two from radishes (Rd4 and Rd15) and two from tomato (Ps21 and Ps95), can infect 27 different ecotypes of Arabidopsis thaliana, causing different responses. All ecotypes tested were highly susceptible to strain Rd15, which caused symptoms similar to those observed in tomato plants. For example, leaf drooping and discoloration developed just 3 days after inoculation, and plants completely wilted within 1 week. Strains Rd4 and Ps95 were less infectious than Rd15. With these two strains, a variety of disease responses were observed among different ecotypes at 2 weeks after inoculation; both susceptible and resistant ecotypes of A. thaliana were identified. Ps21 was the least infectious of the four strains and caused almost no symptoms in any of the ecotypes of Arabidopsis tested. Direct bacterial isolation and plant skeleton hybridization analysis from infected plants indicated that bacterial colonization was correlated with the severity of symptoms. Growth of bacteria was limited to the infection site in resistant plants, whereas the bacteria spread throughout susceptible plants by 1 week after inoculation.
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Guo D, Dunbar JD, Yang CH, Pfeffer LM, Donner DB. Induction of Jak/STAT signaling by activation of the type 1 TNF receptor. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1998; 160:2742-50. [PMID: 9510175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cellular responses to TNF are initiated by either of two cell surface receptors, the type 1 TNF receptor (TNFR1) and the type 2 TNF receptor (TNFR2). Although neither receptor contains an intrinsic protein tyrosine kinase, such activity has been implicated in TNF action. In this study, we show that murine TNF induces the tyrosine phosphorylation and activation of the intracellular Janus tyrosine kinases Jak1, Jak2, and Tyk2 in murine 3T3-L1 adipocytes. Activation of Jak kinases by TNF was associated with tyrosine phosphorylation of STAT1, STAT3, STAT5, and STAT6, but not STAT2 or STAT4, showing that TNF acts on a specific subset of these latent cytoplasmic transcription factors in 3T3-L1 adipocytes. Agonist antiserum to TNFR1 induced Jak kinase and STAT protein phosphorylation. Phosphorylation of Jak proteins was also induced by human TNF, which selectively binds to TNFR1 on murine cells. 35S-labeled Jak kinases were precipitated from a cell-free system and from lysates of 3T3-L1 adipocytes by a glutathione S-transferase fusion protein containing the cytoplasmic domain of TNFR1. These results suggest that the cytoplasmic domain of TNFR1 can directly interact with and form signaling complexes with Jak kinases. Jak2 was precipitated from HeLa cells by antiserum to TNFR1, directly demonstrating their association in vivo. Thus, TNF activates a Jak/STAT signal-transduction cascade by acting through TNFR1.
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Basu L, Yang CH, Murti A, Garcia JV, Croze E, Constantinescu SN, Mullersman JE, Pfeffer LM. The antiviral action of interferon is potentiated by removal of the conserved IRTAM domain of the IFNAR1 chain of the interferon alpha/beta receptor: effects on JAK-STAT activation and receptor down-regulation. Virology 1998; 242:14-21. [PMID: 9501047 DOI: 10.1006/viro.1997.9002] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The first cloned chain (IFNAR1) of the human interferon-alpha (IFN alpha) receptor acts as a species-specific transducer for type 1 IFN action when transfected into heterologous mouse cells. Stably transfected mouse L929 cell lines expressing truncation mutants of the intracellular domain of the human IFNAR1 chain were tested for biological responses to human IFN alpha. Deletion of the intracellular domain resulted in a complete loss of sensitivity to the biological activity of human IFN but markedly increased IFNAR1 cell surface expression, demonstrating that the intracellular domain is required for biological function and contains a domain that negatively regulates its cell surface expression. Removal of the conserved membrane distal 16-amino-acid IRTAM (Interferon Receptor Tyrosine Activation Motif) sequence: (1) increased sensitivity to IFN alpha's antiviral activity, (2) increased the rapid IFN alpha-dependent formation of STAT-containing DNA-binding complexes, (3) prolonged tyrosine phosphorylation kinetics of the JAK-STAT pathway, and (4) blocked the IFN-dependent down-regulation of the IFNAR1 chain. These results indicate that the IRTAM negatively regulates signalling events required for the induction of IFN's biological actions via regulating receptor down-regulation.
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Piao Z, Park C, Lee JS, Yang CH, Choi KY, Kim H. Homozygous deletions of the CDKN2 gene and loss of heterozygosity of 9p in primary hepatocellular carcinoma. Cancer Lett 1998; 122:201-7. [PMID: 9464511 DOI: 10.1016/s0304-3835(97)00403-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
To elucidate the alterations of CDKN2 in hepatocarcinogenesis, we performed a loss of heterozygosity (LOH) study using eight polymorphic markers surrounding the CDKN2 gene and analyzed the homozygous deletions and mutations of the CDKN2 gene in 41 primary hepatocellular carcinomas (HCCs). Frequent LOH (27.8-44%) was found in the eight loci on chromosome 9p, however, no intragenic mutations of CDKN2 were observed by PCR-SSCP analysis. Homozygous deletions were detected in 25 of 41 HCCs (61%) by a comparative multiplex PCR. No expression of the CDKN2 protein was noted in five out of nine available HCCs by Western blot analysis. These results suggest that inactivation of the CDKN2 gene in HCC is a frequent event in which homozygous deletions are the most common mechanism of CDKN2 inactivation.
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Lee DK, Kim B, Lee SG, Gwon HJ, Moon EY, Hwang HS, Seong SK, Lee M, Lim MJ, Sung HJ, Shin DH, Yoon SJ, Yang CH. Momordins inhibit both AP-1 function and cell proliferation. Anticancer Res 1998; 18:119-24. [PMID: 9568065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The activation of Jun/Fos is a crucial factor in transmitting the tumor promoting signal from the extracellular environment to nuclear transcription machinery. One of the final steps in signal transduction is the binding of Jun/Fos to the AP-1 site in order to express gene transcription. Utilizing this concept, we screened about 100 extracts of natural plants to search for a Jun-Fos function inhibitor. The methanol extract of Ampelopsis radix reduced Jun/Foc retardation remarkably. The active principles of the extract were isolated and purified by repeated column chromatography and their structures were identified as oleanolic acid glycosides known as momordin I, Id, and Ie. These compounds reduced the Jun/Fos-DNA interaction and their activities were quantitated with liquid scintillation counting of corresponding bands. Among them, momordin I had the strongest inhibitory activity, with an IC50 value of 22.8 micrograms/ml. The methanol extract and momordin I, Id and Ie also showed cell cytotoxicity against human cancer cell lines. As expected from a gel shift assay, momordin I showed the strongest cytotoxicity and its IC50 value was from 7.280 micrograms/ml to 16.05 micrograms/ml depending on the cell line. With these data, it may be concluded that the mechanism of anticancer activity of momordin I comes from its inhibitory effect on the protein-DNA interaction. The in vivo test was done only with the methanol extract. The extract showed measurable anticancer activity against murine colon cancer. The wet tumor weight reduction rate was 17.73% at 90 mg/kg dose. We suggest that the Jun/Fos-DNA interaction results in cell cytotoxicity.
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Hsu KY, Tan PP, Lin CC, Chen CH, Li JY, Yang CH, Shyr MH. Low-flow anesthesia in adult orthotopic liver transplantation: a preliminary clinical experience. ACTA ANAESTHESIOLOGICA SINICA 1997; 35:229-36. [PMID: 9553239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Anesthesia in orthotopic liver transplantation (OLT) may carry with complex hemodynamic, body temperature, and metabolic alterations. Although OLT cases increased in recent years in Taiwan, experiences remained limited. Notable advantage of low flow anesthesia may include reduced consumption of anesthetic gases and vapors, reduced environmental pollution and cost-saving. This study investigated patient profiles and the feasibility of low-flow rebreathing technique for adult orthotopic liver transplantation. METHODS Since June 1996, there were six OLT patients who received low flow anesthesia with isoflurane. All patients received hepatic veno-venal anastmosis (so-called piggy back procedure). Two patients were excluded from this study because of different surgical procedure (total occlusion of inferior vena cava and inferior vena cava veno-venal anastmosis). During maintenance of anesthesia, isoflurane was carried by a mixture of oxygen and air at a total fresh gas flow of 0.6 L/min. Alongside with the standard anesthesia machine and physiologic monitors, a newly designed Swan-Ganz catheter was introduced to measure and record cardiac output, systemic vascular resistance, pulmonary artery pressure, central venous pressure, and core temperature in a real-time manner. Blood samples were collected at 6 predetermined time-points in each patient for analysis of arterial blood gases, electrolytes, lactate and glucose concentrations. RESULTS The anesthetic time was 916 +/- 26 min (900 to 930 min). All patients regained their consciousness within 30 min after completion of surgery. The hemodynamics were relatively stable except after reperfusion of the liver. There was a significant decrease in mean arterial blood pressure, which occurred with accompaniment of a reduction of systemic vascular resistance and increased cardiac output. Arterial blood gas, electrolyte, and glucose were, however, maintained within acceptable limits. Blood lactate was progressively increased and reached its peak after reperfusion of the liver until the end of surgery. The core temperature was well maintained above 34 degrees C. No patient developed hypoxia or hypercapnia. CONCLUSIONS Low-flow rebreathing anesthetic technique maintained acceptable patient profiles and good body temperature preservation in orthotopic liver transplantation. These characteristics make it a promising method in maintenance of anesthesia for OLT.
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Shyr MH, Ho AC, Lin CC, Hsu KY, Yang CH, Chen CH. Propofol anesthesia in a patient with Isaacs syndrome--report of a case and literature review. ACTA ANAESTHESIOLOGICA SINICA 1997; 35:241-5. [PMID: 9553241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Isaacs syndrome is an unusual lower motor neuron disease characterized by myokymia (muscle twitching), muscular stiffness, and decreased tendon reflexes. We reported a patient who was affected with this rare disease, with manifestation of involuntary muscular contractions and required general anesthesia for bilateral tonsillectomies. Understanding the presentation and characterization of this unusual disease may be helpful in making choice of anesthetics or anesthetic techniques. Its possible mechanisms of action and its specific considerations in anesthesia in the literature are reviewed and discussed.
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Yang CH, Liu CZ, Huang TF, Yang CM, Lui KR, Chen MS, Hung PT. Inhibition of RPE cell-mediated matrix adhesion and collagen gel contraction by crovidisin, a collagen-binding snake venom protein. Curr Eye Res 1997; 16:1119-26. [PMID: 9395771 DOI: 10.1076/ceyr.16.11.1119.5106] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE Cell-mediated collagen gel contraction plays an important role in the pathogenesis of proliferative vitreoretinopathy (PVR). Anti-adhesion therapy has been suggested as a promising strategy in the treatment of PVR. Crovidisin, a snake venom protein isolated from Crotalus viridis, has been shown to bind selectively to collagen and to inhibit collagen-induced platelet aggregation. In the present study, the effectiveness of crovidisin in inhibiting the attachment of retinal pigment epithelial (RPE) cells to collagen, and RPE cell-mediated collagen gel contraction, was evaluated. METHODS Fluorescein isothiocyanate (FITC)-conjugated crovidisin was prepared and used to evaluate its binding affinity for collagen type I, fibronectin, vitronectin, and laminin. The inhibitory effect of crovidisin on RPE cell-mediated extracellular matrix attachment and collagen gel contraction was evaluated by cell adhesion and type I collagen gel contraction assays. The cytotoxic effect of crovidisin was examined with a cell proliferation assay, using the Alamar blue method. Flavoridin, an Arg-Gly-Asp-containing peptide from viper venom, was used for comparison. RESULTS FITC-conjugated crovidisin bound selectively to collagen type I with high affinity. It did not bind to other matrix proteins, including fibronectin, vitronectin and laminin, nor to RPE cells. Crovidisin inhibited RPE cell attachment to type I collagen in a dose-dependent manner. This inhibitory effect was enhanced by the presence of flavoridin. Crovidisin also dose-dependently inhibited RPE cell-mediated type I collagen gel contraction. Crovidisin was non-toxic to RPE cells. CONCLUSIONS Crovidisin, a snake venom-derived collagen-binding protein, possessing an inhibitory activity on RPE cell-collagen interaction and RPE cell-mediated collagen gel contraction, may be a useful tool for studying cell-collagen interaction, and a potential anti-adhesion therapeutic agent for ocular disorders in which cell-collagen interaction in involved, such as PVR.
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Abstract
BACKGROUND Delusional jealousy is a major motive for violence and is sometimes found in demented patients. This study was undertaken to investigate the frequency and the characteristics of delusional jealousy in demented patients. METHOD The sample population consisted of 133 demented patients admitted to the geropsychiatric ward. Patients with and without delusional jealousy were compared in terms of general characteristics and psychotic symptoms. RESULTS Of the 133 demented patients, 21 (15.8%) showed delusional jealousy. Delusional jealousy was found in various types of dementia. There were no significant differences between the two groups in regard to age, age at onset, gender, educational level, and Mini-Mental State Examination score. All patients with delusional jealousy had at least one other psychotic symptom. CONCLUSION Delusional jealousy is a common problem in dementia. The psychobiological factors of delusional jealousy and cognitive function in demented patients may differ. There may be various underlying factors for the development of delusional jealousy in dementia.
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179
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Tsai KS, Lin JC, Chen CK, Cheng WC, Yang CH. Effect of exercise and exogenous glucocorticoid on serum level of intact parathyroid hormone. Int J Sports Med 1997; 18:583-7. [PMID: 9443589 DOI: 10.1055/s-2007-972685] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Most previous studies suggest that physical exercise, or physiological response to exercise such as cortisol and adrenaline secretion regulate parathyroid hormone (PTH) secretion in humans. To investigate the effects and possible interaction of exercise and excessive glucocorticoid on PTH secretion, we examined the serum of levels of intact-PTH, cortisol, adrenocorticotrophic hormone (ACTH), calcium, magnesium and phosphorus before and during one-hour of bicycle-ergometric exercise at 60% of maximal oxygen uptake. These exercise tests were performed on eight Chinese male volunteers aged between 20 and 25 years, once with and once without pretreatment with 0.5 mg of dexamethasone taken orally 9.5 hours in advance. The results showed that dexamethasone pretreatment significantly lowered basal levels of cortisol and ACTH, but intact PTH did not change. After 60 minutes of bicycling, intact PTH level increases by 50% of baseline both with and without dexamethasone pretreatment. Serum levels of calcium, corrected for changes in serum albumin concentration, phosphorus and magnesium also increased in both cases. This study demonstrated an increase of intact-PTH with exercise which was not associated with hypocalcemia or hypomagnesemia, and was not altered in the presence of mild exogenous glucocorticoid excess and suppressed endogenous cortisol secretion.
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Abstract
A 35-year-old male with glucose-6-phosphate dehydrogenase (G6PD) deficiency was admitted because of right chest (pleuritic) pain, fever, cough with scarce production of blood-tinged sputum, and generalized yellowish discolouration of skin for 2 days. Radiographic examination revealed right lower lobe necrotizing pneumonia. Hypotension, dyspnoea and severe haemolysis was noted the next day. Echo-guided lung aspiration and sputum cultures both grew Acinetobacter baumannii. Antibiotic therapy was started immediately, but fever persisted and abscess formation was noted 1 week later. After aggressive supportive and antibiotic therapy, he made a slow but complete recovery from the pneumonia, and was then discharged in a stable condition. Acinetobacter baumannii is a well-known causative agent of nosocomial infections, particularly in intensive units. Community-acquired pneumonia, however, is quite rare, and usually has a fulminant course and high case fatality rate.
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Okubara PA, Arroyo-Garcia R, Shen KA, Mazier M, Meyers BC, Ochoa OE, Kim S, Yang CH, Michelmore RW. A transgenic mutant of Lactuca sativa (lettuce) with a T-DNA tightly linked to loss of downy mildew resistance. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 1997; 10:970-7. [PMID: 9353944 DOI: 10.1094/mpmi.1997.10.8.970] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
One hundred and ninety-two independent primary transformants of lettuce cv. Diana were obtained by co-cultivation with Agrobacterium tumefaciens carrying constructs containing maize Ac transposase and Ds. R2 families were screened for mutations at four genes (Dm) for resistance to downy mildew. One family, designated dm3t524, had lost resistance to an isolate of Bremia lactucae expressing the avirulence gene Avr3. Loss of resistance segregated as a single recessive allele of Dm3. The mutation was not due to a large deletion as all molecular markers flanking Dm3 were present. Loss of Dm3 activity co-segregated with a T-DNA from which Ds had excised. Genomic DNA flanking the right border of this T-DNA was isolated by inverse polymerase chain reaction. This genomic sequence was present in four to five copies in wild-type cv. Diana. One copy was missing in all eight deletion mutants of Dm3 and altered in dm3t524, indicating tight physical linkage to Dm3. Three open reading frames (ORFs) occurred in a 6.6-kb region flanking the insertion site; however, expression of these ORFs was not detected. No similarities were detected between these ORFs and resistance genes cloned from other species. Transgenic complementation with 11-to 27-kb genomic fragments of Diana spanning the insertion site failed to restore Dm3 function to two ethyl methanesulfonate (EMS)-induced mutants of Dm3 or to cv. Cobham Green, which naturally lacks Dm3 activity. Therefore, either the T-DNA inserted extremely close to, but not within, Dm3 and the mutation may have been caused by secondary movement of Ds, or Dm3 activity is encoded by a gene extending beyond the fragments used for complementation.
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Kim H, Yoon BY, Yang CH. Evidence for the essential histidine residues in geranylgeranyl transferase type I from bovine testis. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1997; 43:453-62. [PMID: 9350353 DOI: 10.1080/15216549700204241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Geranylgeranyl transferase was purified 30,000-fold by sequential use of 30-50% ammonium sulfate fractionation, Q-Sepharose anion exchange chromatography, Phenyl Superose hydrophobic interaction chromatography, Sephacryl S-300 gel filtration chromatography, and peptide (YREKKFFCAIL) affinity chromatography. Geranylgeranyl transferase, when incubated with diethyl pyrocarbonate (DEPC), a histidine-specific reagent, shows time-dependent inactivation, and the activity is restored by the addition of neutral hydroxylamine. The inactivation follows pseudo-first order kinetics with a second order rate constant of 0.319 M-1min-1. The overall results thus provide evidence that a histidine residue in the active site is involved in the catalytic mechanism of the geranylgeranyl transferase reaction.
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Tsai SJ, Hwang JP, Yang CH, Liu KM, Lo Y. Capgras' syndrome in a patient with vascular dementia: a case report. Kaohsiung J Med Sci 1997; 13:639-42. [PMID: 9385782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Capgras' syndrome is characterized by a subjective certainty that a familiar person has been replaced by an identical double. This syndrome has been observed in psychiatric and neurological diseases, and has been reported in several cases of dementia of the Alzheimer type. Here, we present a patient with vascular dementia in whom Capgras' syndrome developed in the early stages of dementia, and who exhibited violence. This case suggests that Capgras' syndrome can occur in vascular dementia. In older patients with this syndrome, dementia should also be considered in its differential diagnosis. In addition, patients with Capgras' syndrome should be evaluated for violent potential.
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Wang H, Yang CH, Lee G, Chang F, Wilson H, del Campillo-Campbell A, Campbell A. Integration specificities of two lambdoid phages (21 and e14) that insert at the same attB site. J Bacteriol 1997; 179:5705-11. [PMID: 9294425 PMCID: PMC179457 DOI: 10.1128/jb.179.18.5705-5711.1997] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
It was shown previously that phage 21 and the defective element e14 integrate at the same site within the icd gene of Escherichia coli K-12 but that 21 integrase and excisionase excise e14 in vivo very infrequently compared to excision of 21. We show here that the reverse is also true: e14 excises itself much better than it excises an adjacent 21 prophage. In vitro integrase assays with various attP substrates delimit the minimal attP site as somewhere between 366 and 418 bp, where the outer limits would include the outermost repeated dodecamers suggested as arm recognition sites by S. J. Schneider (Ph.D. dissertation, Stanford University, Stanford, Calif., 1992). We speculate that the reason 21 attP is larger than lambda attP (240 bp) is because it must include a 209-bp sequence homologous to the 3' end of the icd transcript in order to allow icd expression in lysogens. Alteration of portions of 21 attP to their e14 counterparts shows that 21 requires both the arm site and core site sequences of 21 but that replacements by e14 sequences function in some positions. Consistent with Schneider's in vivo results, and like all other known integrases from lambdoid phages, 21 requires integration host factor for activity.
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Abstract
This report studied behavioural disturbances in psychiatric inpatients with dementia of the Alzheimer's type (DAT) in Taiwan. The sample consisted of 75 inpatients with DAT who were consecutively admitted to the geropsychiatric ward. Their behavioural disturbances were obtained from semistructured interviews with families and ward observation. There were eight main behavioural disturbances: getting lost, repetitive phenomena, sleep disturbance, aggression, wandering, hyperphagia, hoarding behaviour, and inappropriate sexual behaviour. Number of behavioural disturbances, wandering, hyperphagia and sleep disturbance were significantly associated with the severity of cognitive impairment.
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186
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Hwang JP, Tsai SJ, Yang CH. Geriatric psychiatry in Taiwan. Int J Geriatr Psychiatry 1997; 12:960-3. [PMID: 9309477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Yang CH, Hung PT. Intraocular lens position and anterior chamber angle changes after cataract extraction in eyes with primary angle-closure glaucoma. J Cataract Refract Surg 1997; 23:1109-13. [PMID: 9379386 DOI: 10.1016/s0886-3350(97)80089-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To prospectively study the anterior chamber angle in eyes with chronic primary angle-closure glaucoma (PACG) having posterior chamber intraocular lens (IOL) implantation and evaluate IOL position and intraocular pressure (IOP). SETTING National Taiwan University Hospital, Taipei, Taiwan. METHODS Using Scheimpflug image processing, the anterior chamber angles were studied in 20 consecutive eyes with chronic PACG and 10 control eyes before and after posterior chamber IOL implantation. Anterior chamber depth, chamber angle width, IOL position, and IOP change were evaluated. RESULTS Mean anterior chamber depth in the PACG group was 2.04 +/- 0.29 mm preoperatively and 3.44 +/- 0.16 mm postoperatively. The anterior chamber angle widened significantly in relation to the superior, inferior, temporal, and nasal quadrants after surgery. The degree of IOL tilting and decentration was the same in both the PACG and control groups. All eyes in the PACG group maintained an IOP under 21 mm Hg during the 6 month follow-up. Eighty-four percent maintained or decreased their antiglaucoma medication; 16% required increased medication. CONCLUSION Cataract extraction with posterior chamber IOL implantation in eyes with PACG controlled IOP well in most cases.
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Yang CH, Lee YC. Major depressive disorder with delusion of having AIDS: a case report. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1997; 60:173-5. [PMID: 9419956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Acquired immune deficiency syndrome (AIDS) has become a topic of increasing public concern. Several conditions have been described in patients who are afraid that they have acquired AIDS, including depression, somatization disorders, hypochondriasis, adjustment disorders and various psychoses. This paper presents a case study of a young man with persistent fear of having AIDS. In spite of negative HIV test results, the patient still insisted that he suffered from AIDS. The psychiatric diagnosis was major depressive disorder with delusion of having AIDS. The patient was treated with fluoxetine 40 mg qd and sulpiride 400 mg qn. After two weeks on medication, his fear of AIDS subsided and he improved remarkably. The most important intervention in patients with delusion of having AIDS is to identify and treat the underlying psychopathology. The following case is representative of our experience.
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Cho HS, Park YN, Lyu CJ, Park SM, Oh SH, Yang CH, Yang WI, Kim KY. EBV-elicited familial hemophagocytic lymphohistiocytosis. Yonsei Med J 1997; 38:245-8. [PMID: 9339134 DOI: 10.3349/ymj.1997.38.4.245] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Familial hemophagocytic lymphohistiocytosis (FHL) is a rapidly fatal illness, usually encountered in infancy, characterized by fever, hepatosplenomegaly, pancytopenia, and central nervous system involvement. Microscopic examination of tissue shows a non-malignant lymphohistiocytic infiltrate, with prominent erythrophagocytosis. FHL is an autosomal recessive hereditary disorder but may develop secondarily to other conditions such as immunosuppression, malignancies, fat overload and certain infections. We recently experienced a case of siblings developing FHL, which may be associated with EBV infection.
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Shyr MH, Tsai TH, Yang CH, Chen HM, Ng HF, Tan PP. Propofol anesthesia increases dopamine and serotonin activities at the somatosensory cortex in rats: a microdialysis study. Anesth Analg 1997; 84:1344-8. [PMID: 9174318 DOI: 10.1097/00000539-199706000-00031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We sought to estimate the activities of dopamine and serotonin in animals receiving propofol anesthesia. The in vivo microdialysis technique was used in Sprague-Dawley rats (n = 6) to measure the major metabolites of dopamine and serotonin, i.e. 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (4-hydroxy-3-methyphenylacetic acid; HVA) and 5-hydroxy indole acetic acid (5-HIAA) in the somatosensory cortex. We also measured the levels of propofol in the brain and blood by microdialysis sampling in another group of rats (n = 6). During the experiment, the rat was infused intravenously (IV) with propofol at a rate of 10 mg x kg(-1) x h(-1) for 60 min and 60 mg x kg(-1) x h(-1) for 40 min. We found that IV infusion of propofol at a rate of 60 mg x kg(-1) x h(-1) significantly increased DOPAC, HVA, and 5-HIAA. We also determined that these changes correlated well with propofol levels in the brain and blood. We concluded that anesthetic doses of propofol increased the functional activities of dopamine and serotonin in the cortex. These increases correlate well with propofol levels in the cortex and blood.
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191
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Yang CC, Chou SC, Hung PT, Yang CH, Hung L, Tsai CB. Anterior chamber angles shallowing and intraocular pressure after topical pilocarpine. J Ocul Pharmacol Ther 1997; 13:219-24. [PMID: 9185037 DOI: 10.1089/jop.1997.13.219] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Pilocarpine has been well recognized as the drug of choice for acute angle-closure glaucoma. The purpose of this study is to clarify quantitatively the change of anterior chamber angle and depth with the passage of time after pilocarpine drop administration. Chamber angles of the four quadrants and chamber depths were measured in 18 normal subjects by Scheimpflug Video Image prior to and 30, 60, and 180 minutes after administration of one drop of 4% pilocarpine in one eye, while the opposite eye served as control. The anterior chamber angle and depth showed a significant shallowing at 30, 60 and 180 minutes after 4% pilocarpine administration with a maximal effect of -3.61 degrees and -0.15 mm at 30 minutes, respectively, while the reduction of intraocular pressure reached its maximal effect at 180 minutes. These facts should be well understood in the treatment of angle-closure glaucoma.
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192
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Hwang JP, Yang CH, Tsai SJ, Liu KM. Delusions of theft in dementia of the Alzheimer type: a preliminary report. Alzheimer Dis Assoc Disord 1997; 11:110-2. [PMID: 9194958 DOI: 10.1097/00002093-199706000-00008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Delusions of theft are commonly found in patients with dementia of the Alzheimer type (DAT). This report describes the frequency, onset, and characteristics of delusions of theft in DAT patients. The sample consisted of 54 geropsychiatric inpatients with DAT; delusions of theft were found in 30 (55.6%) patients. Two thirds of these patients had delusions of theft within 1 year after onset of illness. There were no significant differences in age, age of onset, duration of disease, years of education, or the Mini-Mental State Examination (MMSE) score between patients with and without delusions of theft. Delusions of theft frequently occur in the early stage of dementia, when the patients' cognitive impairments are relatively mild. The presence of this symptom may warrant a diagnosis of DAT.
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193
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Pfeffer LM, Mullersman JE, Pfeffer SR, Murti A, Shi W, Yang CH. STAT3 as an adapter to couple phosphatidylinositol 3-kinase to the IFNAR1 chain of the type I interferon receptor. Science 1997; 276:1418-20. [PMID: 9162009 DOI: 10.1126/science.276.5317.1418] [Citation(s) in RCA: 222] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
STAT (signal transducers and activators of transcription) proteins undergo cytokine-dependent phosphorylation on serine and tyrosine. STAT3, a transcription factor for acute phase response genes, was found to act as an adapter molecule in signal transduction from the type I interferon receptor. STAT3 bound to a conserved sequence in the cytoplasmic tail of the IFNAR1 chain of the receptor and underwent interferon-dependent tyrosine phosphorylation. The p85 regulatory subunit of phosphatidylinositol 3-kinase, which activates a series of serine kinases, bound to phosphorylated STAT3 and subsequently underwent tyrosine phosphorylation. Thus, STAT3 acts as an adapter to couple another signaling pathway to the interferon receptor.
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194
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Wu YL, Chang CC, Chang HC, Yang CH, Liao ST. Clinical experience of HIV/AIDS in a municipal hospital in Taiwan. ZHONGHUA MINGUO WEI SHENG WU JI MIAN YI XUE ZA ZHI = CHINESE JOURNAL OF MICROBIOLOGY AND IMMUNOLOGY 1997; 30:84-95. [PMID: 10592814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
To describe the spectrum of epidemiological and major clinical manifestations of patients infected by human immunodeficiency virus type 1 (HIV-1) in a municipal hospital, a retrospective review was done of 53 HIV-1-infected patients who had been admitted to Taipei Municipal Jen-Ai Hospital between January 1990, and July 1996. The majority (94.3%) of the patients in the cohort were male. Peak incidence was found in the fourth decade (28.3%). Forty-four (83%) patients presented in the first hospital stay with acquired immunodeficiency syndrome (AIDS). The mean duration between establishment of diagnosis of HIV-1 infection and that of AIDS was 11.2 (0-84) months. Heterosexual transmission accounted for 54.7% of the infections in the study group, and bi-/homosexual men made up another 32%. Psychosis of new onset was noted in two patients. In all AIDS indicator conditions, Pneumocystis carinii pneumonia (PCP) was the leading opportunistic infection among AIDS patients. PCP was also on the top of initial manifestations of HIV-1 infection. One patient with Penicillium marneffei infection was diagnosed to have AIDS. The mean CD4 count at admission of AIDS patients was much lower than that of non-AIDS patients (32 vs. 297/microliter, p < 0.0005). During the follow-up period 24 of 53 patients died. Mean survival time of 23 expired patients after establishment of diagnosis of AIDS was 6.4 (0-29) months. The results indicated that males outnumbered females greatly in the number of cases. Sexual activity remained the most important route of infection. Psychosis of new onset may be an early manifestation of HIV-associated encephalopathy and requires more attention. In addition, the outcome was poor as most patients in this area did not become aware of risk of HIV-1 infection until they were seriously illed with full-blown AIDS that they would seek medical help. PCP was the most common incentive for medical consultation. Penicillium marneffei infection is endemic in southeast Asia, and should be classified as an AIDS indicator condition in Taiwan.
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195
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Lin AT, Yang CH, Chang LS. Impact of aging on rat urinary bladder fatigue. J Urol 1997; 157:1990-4. [PMID: 9112578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE Little is known about the fatigability of the urinary bladder. In these experiments, we characterized contractile and bioenergetic changes in bladder fatigue and investigated the impact of aging on these changes. MATERIALS AND METHODS Whole urinary bladders from 3-month-old (n = 17) and 24-month-old (n = 12) SD rats were isolated and individually mounted in organ baths. The bladders were electrostimulated repeatedly (50 volts, 32 Hz, 1 MS; every 2.5 minutes). The pressure generation, rate of pressure generation and the emptying ability (% volume emptied) of the isolated bladders were measured with each stimulation. After the 20th electrostimulation, the bladders were immediately stimulated with 500 microM bethanechol. Upon completion of their series of stimulations, some of the bladders were quickly frozen in liquid nitrogen. Tissue phosphocreatine and ATP content of the frozen bladders and a group (six 3-month-old and six 24-month-old rats) of fresh bladder tissues was determined using high performance liquid chromatography (HPLC). RESULTS The results can be summarized as follows: (1) Pressure generation, rate of pressure generation and emptying ability were gradually reduced in both young and aged bladders as repeated stimulation proceeded. (2) The final bethanechol stimulation emptied the same intravesical volume as the 20th electrostimulation emptied (in both groups), indicating that bladder fatigue is due to a post-synaptic mechanism. (3) As compared to their own first responses, aged rats exhibited significantly greater rates of reduction in both pressure generation and emptying ability than did young rats. (4) Analysing fresh bladder tissues, the phosphocreatine and ATP concentration of the aged bladders were significantly less than those of the young bladders-13.2 +/- 2.0 and 1.2 +/- 0.3 nmol/mg. protein respectively in the aged bladders vs. 21.2 +/- 1.8 and 7.5 +/- 1.0 nmol/mg. protein respectively in the young bladders. After repeated stimulation, phosphocreatine and ATP concentration were reduced in both groups (1.4 +/- 0.3 and 0.43 +/- 0.1 nmol./mg. protein in the aged bladders, 7.5 +/- 1.4 and 4.1 +/- 0.5 nmol./mg. protein in the young bladders), with a greater degree of reduction in the aged bladders. CONCLUSION These observations indicate that, in response to repeated electrostimulation, aged rat bladders became fatigued faster than young bladders. Decreased capability in energy production might be one contributing factor for faster fatiguability of the aged urinary bladders.
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196
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Pfeffer LM, Basu L, Pfeffer SR, Yang CH, Murti A, Russell-Harde D, Croze E. The short form of the interferon alpha/beta receptor chain 2 acts as a dominant negative for type I interferon action. J Biol Chem 1997; 272:11002-5. [PMID: 9110990 DOI: 10.1074/jbc.272.17.11002] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We have characterized the functional properties of the short form of the human interferon alpha/beta receptor chain 2 (IFNAR2), denoted IFNAR2.1. IFNAR2.1 contains a shortened cytoplasmic domain when compared with the recently cloned full-length IFNAR2 chain (IFNAR2. 2). We show that IFNalpha8 and IFNbeta1b induce antiviral and antiproliferative activity in mouse cell transfectants expressing the human IFNAR1 chain of the receptor and induce the formation of STAT1/STAT2 dimers in IFN-stimulated response element (ISRE)-dependent gel shift assays. In contrast, coexpression of IFNAR2.1 with IFNAR1 reduces the IFN-induced antiviral, antiproliferative and ISRE-dependent gel shift binding activity conferred by IFNAR1 alone. No antiviral or antiproliferative response to IFN, nor IFN-induced ISRE-dependent gel shift binding activity, was observed when IFNAR2.1 was expressed alone in murine cells. Therefore, IFNAR2.1 acts as a dominant negative for these IFN-induced activities. Our results suggest that IFNAR2.1 represents a nonfunctional version of the full-length chain (IFNAR2.2).
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197
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Chiao JH, Roy K, Tolner B, Yang CH, Sirotnak FM. RFC-1 gene expression regulates folate absorption in mouse small intestine. J Biol Chem 1997; 272:11165-70. [PMID: 9111015 DOI: 10.1074/jbc.272.17.11165] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Mediated folate compound transport inward in isolated luminal epithelial cells from mouse small intestine was delineated as pH-dependent and non-pH-dependent components on the basis of their differential sensitivity to the stilbene inhibitor, 4, 4'-diisothiocyanatostilbene-2,2'-disulfonic acid. pH dependence was manifested as higher maximum capacity (Vmax) for influx of l, L-5-CH3-H4folate at acidic pH compared with neutral or alkaline pH with no effect on saturability (Km). The pH-dependent component was relatively insensitive to inhibition by 4, 4'-diisothiocyanatostilbene-2,2'-disulfonic acid and highly saturable (Km or Ki = 2 to 4 microM) in the case of folic acid, folate coenzymes, and 4-aminofolate analogues as permeants or inhibitors. The non-pH-dependent component was highly sensitive to 4, 4'-diisothiocyanatostilbene-2,2'-disulfonic acid and poorly and variably saturable (Km or Ki = 20 to >2000 microM) with respect to these folate compounds. Only the pH-dependent transport component was developmentally regulated, showing much higher maximum capacity for l,L-5-CH3-H4folate influx in mature absorptive rather than proliferative crypt cells. The increase in pH-dependent influx during maturation was associated with an increase in RFC-1 gene expression in the form of a 2.5-kilobase RNA transcript and 58-kDa brush-border membrane protein detected by folate-based affinity labeling and with anti-mouse RFC-1 peptide antibodies. The size of this protein was the same as that encoded by RFC-1 mRNA. The treatment of mature absorptive cells with either the affinity label or the anti-RFC-1 peptide antibodies inhibited influx of l, L-[3H]-5-CH3-H4folate in a concentration-dependent manner. These results strongly suggest that pH-dependent folate absorption in this tissue is regulated by RFC-1 gene expression.
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198
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McNeill H, Yang CH, Brodsky M, Ungos J, Simon MA. mirror encodes a novel PBX-class homeoprotein that functions in the definition of the dorsal-ventral border in the Drosophila eye. Genes Dev 1997; 11:1073-82. [PMID: 9136934 DOI: 10.1101/gad.11.8.1073] [Citation(s) in RCA: 148] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The Drosophila eye is composed of dorsal and ventral mirror-image fields of opposite chiral forms of ommatidia. The boundary between these fields is known as the equator. We describe a novel gene, mirror (mrr), which is expressed in the dorsal half of the eye and plays a key role in forming the equator. Ectopic equators can be generated by juxtaposing mrr expressing and nonexpressing cells, and the path of the normal equator can be altered by changing the domain of mrr expression. These observations suggest that mrr is a key component in defining the dorsal-ventral boundary of tissue polarity in the eye. In addition, loss of mrr function leads to embryonic lethality and segmental defects, and its expression pattern suggests that it may also act to define segmental borders. Mirror is a member of the class of homeoproteins defined by the human proto-oncogene PBX1. mrr is similar to the Iroquois genes ara and caup and is located adjacent to them in this recently described homeotic cluster.
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199
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Perentesis JP, Bendel AE, Shao Y, Warman B, Davies SM, Yang CH, Chandan-Langlie M, Waddick KG, Uckun FM. Granulocyte-macrophage colony-stimulating factor receptor-targeted therapy of chemotherapy- and radiation-resistant human myeloid leukemias. Leuk Lymphoma 1997; 25:247-56. [PMID: 9168435 DOI: 10.3109/10428199709114164] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Contemporary therapies for acute myeloid leukemia (AML) commonly fail to cure patients because of the emergence of drug resistance. Drug resistance in AML is multifactorial but can be associated with the overexpression of transmembrane transporter molecules, including P-glycoprotein (Pgp) or the multidrug resistance-associated protein (MRP), or associated with inactivation of the p53 tumor suppressor gene, as well as overexpression of the anti-apoptotic protein bcl-2. We are investigating if novel recombinant biotherapeutics can circumvent these resistance mechanisms to effectively treat refractory AML. To target the lethal action of diphtheria toxin (DT) to high affinity granulocyte-macrophage colony-stimulating factor (GMCSF) receptors on AML blasts, we have produced a recombinant chimeric fusion toxin, DTctGMCSF. Since DTctGMCSF enters and kills its target cells by unique mechanisms (GMCSF-receptor binding and protein synthesis inhibition) and is not similar in structure to Pgp or MRP substrates, we postulated that it would be an active agent against therapy-resistant AML. DTctGMCSF was selectively cytotoxic (IC50 1-10ng/ml) to GMCSF-receptor positive AML cells expressing the Pgp- or MRP-associated multi-drug resistant phenotypes, despite high level resistance to conventional chemotherapeutic agents. DTctGMCSF also efficiently killed AML cells deficient in p53 expression, as well as radiation-resistant AML cells and mixed lineage leukemia cells expressing high levels of bcl-2. In addition, DTctGMCSF killed > 99% of primary leukemic progenitor cells from therapy-refractory AML patients under conditions that we have previously found to not adversely affect the proliferative capacity or differentiation of pluripotent normal hematopoietic progenitor cells. DTctGMCSF may prove useful in treating myeloid leukemias that are otherwise resistant to a wide range of conventional therapies.
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Bendel AE, Shao Y, Davies SM, Warman B, Yang CH, Waddick KG, Uckun FM, Perentesis JP. A recombinant fusion toxin targeted to the granulocyte-macrophage colony-stimulating factor receptor. Leuk Lymphoma 1997; 25:257-70. [PMID: 9168436 DOI: 10.3109/10428199709114165] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Human granulocyte-macrophage colony stimulating factor (GMCSF) and its high affinity receptor function to regulate the proliferation and differentiation of myeloid lineage hematopoietic cells, and may participate in the pathogenesis of many malignant myeloid diseases. We have used genetic engineering based on the elucidated molecular structures of human granulocyte-macrophage colony-stimulating factor and diphtheria toxin (DT) to produce a recombinant fusion toxin, DTctGMCSF, that targets diphtheria toxin to high affinity GMCSF receptors expressed on the surface of blast cells from a large fraction of patients with acute myeloid leukemia (AML). DTctGMCSF was specifically immunoreactive with antidiphtheria toxin and anti-GMCSF antiseras, and exhibited the characteristic catalytic activity of diphtheria toxin, catalyzing the in vitro ADP-ribosylation of purified elongation factor 2. The cytotoxic effects of DTctGMCSF were examined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-tetrazolium (MTT) bromide assay of cell viability and in vivo assays of protein synthesis inhibition. DTctGMCSF were specifically cytotoxic to human leukemia cell lines bearing high affinity receptors for human GMCSF with IC50 of 10(-9) to 10(-11) M. It was not toxic to mammalian hematopoietic cell lines lacking human GMCSF (hGMCSF) receptors. In receptor positive cells, cytotoxicity can be specifically blocked by a large excess of hGMCSF, confirming that its cytotoxicity is mediated through the hGMCSF receptor. THough DTctGMCSF inhibited granulocyte-macrophage colony formation by committed myeloid progenitor cells (CFU-GM), it did not significantly affect erythroid burst formation by committed erythroid progenitor cells (BFU-E), or mixed granulocyte-erythroid-macrophage-megakaryocyte colony formation by pluripotent multilineage progenitor cells (CFU-GEMM). DTctGMCSF holds promise for the treatment of myeloid lineage malignancies, and is a useful reagent to study hematopoiesis.
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