Biomedical subjects

S Y Kuo

Publications and source records attributed to S Y Kuo.

36 records · Page 2Linked to original sources

PubMed1996

Subunit structure of vacuolar proton-pyrophosphatase as determined by radiation inactivation.

Vacuolar proton-pyrophosphatase (H(+)-PPase) of mung bean seedlings contains a single kind of polypeptide with a molecular mass of approx. 73 kDa. However, in this study, a molecular mass of approx. 140 kDa was obtained for the purified vacuolar H(+)-PPase by size-exclusion gel-filtration chromatography, suggesting that the solubilized form of this enzyme is a dimer. Radiation inactivation analysis of tonoplast vesicles yielded functional masses of 141.5 +/- 10.8 and 158.4 +/- 19.5 kDa for PP1 hydrolysis activity and its supported proton translocation respectively. These results confirmed the in situ dimeric structure of the membrane-bound H(+)-PPase of plant vacuoles. Further target-size analysis showed that the functional unit of purified vacuolar H(+)-PPase was 71.1 +/- 6.7 kDa, indicating that only one subunit of the purified dimeric complex would sufficiently display its enzymic reaction. Moreover, in the presence of valinomycin and KCl, the functional size of membrane-bound H(+)-PPase was decreased to approx. 63.4 +/- 6.3 kDa. A working model was proposed to elucidate the structure of native H(+)-PPase on vacuolar membrane as a functional dimer. Factors that would disturb the membrane, e.g. membrane solubilization and the addition of valinomycin and KCl, may induce an alteration in its enzyme structure, subsequently resulting in a different functional size.

Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone↗

PubMed1996

Involvement of tyrosine residue in the inhibition of plant vacuolar H(+)-pyrophosphatase by tetranitromethane.

Plant vacuolar vesicles contain a novel H(+)-translocating pyrophosphatase (H(+)-PPase, EC 3.6.1.1). Modification of tonoplast vesicles and purified vacuolar H(+)-PPase from etiolated mung bean seedlings with tetranitromethane (TNM) resulted in a progressive decline in H(+)-translocating pyrophosphatase activity. The half-maximal inhibition was brought about by 0.6, 1.0, and 0.8 mM TNM for purified and membrane-bound H(+)-PPases, and its associated proton translocation, respectively. The maximal inhibition of vacuolar H(+)-PPase by TNM occurred at a pH value above 8. Loss of activity of purified H(+)-pyrophosphatase followed pseudo-first order rate kinetics, yielding a first-order rate constant (k2) of 0.039 s(-1) and a steady-state dissociation constant of inactivation (Ki) of 0.02 mM. Covalent modification of vacuolar H(+)-PPase by TNM increased Km value of the enzyme for its substrate without a significant effect on Vmax. Double logarithmic plots of the pseudo-first order rate constant (kobs) versus TNM concentration exhibited a slope of 0.88, suggesting that at least one tyrosine residue was involved in the inactivation of H(+)-PPase enzymatic activity. Further spectrophotometric measurements of the nitrated H(+)-pyrophosphatase indicated that TNM could modify approximately two tyrosine residues/subunit of the enzyme. However, Tsou's analysis revealed that only one of those modified tyrosine residues directly participated in the inhibition of enzymatic activity of vacuolar H(+)-PPase. The physiological substrate, i.e., dimagnesium pyrophosphate, provided substantial protection against inactivation by TNM. Moreover, NEM pretreatment of the enzyme decreased the number of subsequent nitration of vacuolar H(+)-PPase. Taken together, we suggest that vacuolar H(+)-pyrophosphatase contains a substrate-protectable tyrosine residue conferring to the inhibition of its activity and this tyrosine residue may be located in a domain sensitive to the modification of Cys-634 by NEM.

Electrophoresis, Polyacrylamide Gel↗

PubMed1995

Acquired immunodeficiency syndrome with CNS toxoplasmosis: a case report.

Central nervous system (CNS) toxoplasmosis is an important infectious complication of acquired immunodeficiency syndrome (AIDS) which appears to result from reactivation of a previously acquired infection and requires prolonged treatment. A 31-year-old male presented in a drowsy mental state and with an unstable gait. Computerized tomographic (CT) scan and magnetic resonance imaging (MRI) showed multiple nodular lesions in the cerebrum and cerebellum; the seropositivity for the human immunodeficiency virus (HIV-1) and high serum IgG toxoplasma titers were also demonstrated. A presumptive diagnosis of CNS toxoplasmosis was based on neurological signs and neuroradiological findings. This was confirmed by improvement in both clinical and neuroradiological pictures during treatment with pyrimethamine and clindamycin. Four months later, however the patient died of intracranial hemorrhage and massive upper GI bleeding.

Acquired Immunodeficiency Syndrome↗

PubMed1995

Coexisting IgA nephropathy and leukocytoclastic cutaneous vasculitis associated with ankylosing spondylitis: a case report.

A patient with ankylosing spondylitis and coexisting IgA nephropathy and leukocytoclastic cutaneous vasculitis is described. Renal biopsy demonstrated mesangial proliferative glomerulonephritis with prominent IgA, C3 and fibrin deposition in the glomeruli. Simultaneously, leukocytoclastic cutaneous vasculitis with prominent IgG, IgA and C3 deposition of dermal vessel wall was also observed in the skin biopsy specimen. Such associations have been previously reported in only four cases. This report once again indicates that antigenic mucosal stimulation may play an important role in the pathogenesis of ankylosing spondylitis.

Adult↗

PubMed1995

Lupus in Chinese male: a retrospective study of 61 patients.

BACKGROUND: Systemic lupus erythematosus (SLE) has traditionally been considered a disease of women, and is uncommon in men. In recent years, several large clinical series of male lupus patients have been reported. As no known data are available for lupus in males from Taiwan, a retrospective analysis of data from male lupus patients was done to determine whether these patients differed from other series of male or female SLE patients in the literature. METHODS: Sixty-one male lupus patients, diagnosed and followed in Tri-Service General Hospital, between 1983 and 1993, were studied and their data analyzed, retrospectively. RESULTS: The mean age of diagnosis was 30 +/- 17 (mean +/- SD, range: 13-81) years. The peak age of diagnosis was between 13 and 40 years. The mean duration of follow-up was 36 +/- 36 (range: 2-256) months. The 1-, 5- and 10-year survival rates were 84%, 76% and 75%, respectively. The frequency of clinical manifestations were renal disease, 75%; malar rash, 70%; arthritis, 60%; fever, 56%; photosensitivity, 48%; pleuritis, 39%; pericarditis, 31%; alopecia, 31%; mucosal ulcers, 29%; neuropsychiatric disease, 26%; discoid lupus, 21%; vasculitis, 15%; Raynaud's phenomenon, 10%; and lymphadenopathy, 2%. The frequency of abnormal laboratory findings were antinuclear antibodies (ANA), 95%; hypocomplementemia, 77%; antibodies to double-stranded DNA (anti-dsDNA), 57%; leukopenia, 44%; lupus erythematosus (LE) cells, 39%; anti-Ro, 39%; anti-Smith antibodies (anti-Sm), 19%; thrombocytopenia, 18%; rheumatoid factor, 17%; anti-ribonucleoprotein antibody (anti-RNP), 14%; autoimmune hemolytic anemia, 8%; false-positive venereal disease research laboratory test (VDRL), 6% and anti-La, 4%. CONCLUSIONS: In a review of the 61 ethnic Chinese male lupus patients, a higher frequency of renal disease, malar rash and photosensitivity, but a lower frequency of arthritis and lymphadenopathy, compared to previous reports of Caucasians. There were no significant immunological differences from other series of male lupus, except a lower frequency of anti-dsDNA. In general, poor prognosis was noted for male lupus patients here.

Adolescent↗

PubMed1995

X-linked agammaglobulinemia: a case report.

A 20-year-old male was admitted with fever and hemoptysis. Agammaglobulinemia was found, with bronchiectasis and sinusitis. Clinical and laboratory evidence included immunological examinations, bone marrow and small intestinal biopsies. Results suggested a diagnosis of X-linked agammaglobulinemia. After treatment with antibiotics and intravenous human immunoglobuline, the clinical symptoms demonstrated progressive improvement. The case is reported along with a review of the literature.

Adult↗

PubMed1994

Prostromelysin and procollagenase genes are differentially up-regulated in chondrocytes from the knees of rabbits with experimental osteoarthritis.

OBJECTIVE: To determine the relative expressions of matrix metalloprotease (MMP) genes pro-MMP1 and pro-MMP3 in the cartilage of rabbits with experimentally induced osteoarthritis (OA), and to assess the role of the chondrocyte in this process. METHODS: OA was induced in rabbits after partial medial meniscectomy. Rabbits were killed at 4 weeks or 8 weeks, and total cellular RNA was prepared from cartilage and probed by Northern blotting with pro-MMP 32P-labeled complementary DNA. Monolayer chondrocytes were used to assess MMP-inducing activity of chondrocyte factor(s). RESULTS: Pro-MMP messenger RNAs (mRNAs) were up-regulated in experimental OA cartilage; pro-MMP3 mRNA expression exceeded that of pro-MMP1. Conditioned medium from OA-derived chondrocytes up-regulated pro-MMP mRNAs in normal chondrocytes. CONCLUSION: Up-regulation of MMP genes in this OA model may contribute to cartilage degradation. Chondrocytes up-regulate MMP genes via an autocrine pathway.

Animals↗

PubMed1994

Positive antinuclear antibody in peripheral T cell lymphoma: a case report.

The association of malignant lymphoma with positive antinuclear antibody is uncommon, and their relationship is not clear. Here a 35-year-old man is presented who initially had a high titer of antinuclear antibody; later, peripheral T cell lymphoma was found. It is suggested than an unexplained high antinuclear antibody titer may warrant searching for a malignancy.

Adult↗

PubMed1994

An experimental model of osteoarthritis in rabbit.

BACKGROUND: From both a microscopic and a metabolic view, experimental animal models are very important for study of the pathogenesis of osteoarthritis. A new, different operative procedure was used in rabbit models, and the pathologic findings were evaluated. METHODS: Twelve New Zealand white rabbits were divided into six groups; eight were used as animal models and four, for drug efficacy study. Transection of the anterior cruciate and medial collateral ligaments on the left knee joint, and sham-operation were performed on the right knee joint. Rabbits were sacrificed post surgery from 4, 6, 8 and 12 weeks. Eight parameters from gross to microscopic findings were used in order to evaluate osteoarthritic changes. Indomethacin and aspirin were chosen for the drug efficacy experiment; the two rabbits of each group were sacrificed at the end of the sixth week post-surgery. RESULTS: According to pathological findings, this operative procedure can produce osteoarthritic changes, visible both microscopically and macroscopically. There were osteoarthritic changes in the fourth week post-surgery group and, obviously, in the eighth week; these persisted until 12th weeks post-surgery. Neither indomethacin nor aspirin showed any effect in preventing osteoarthritis progression. CONCLUSIONS: Transection of the anterior cruciate and medial collateral ligament rabbit model can produce osteoarthritic lesions in the knee joint. This model can be used for further biochemical and metabolic studies.

Animals↗

PubMed1994

Intermittent intravenous treatment of lupus nephritis with cyclophosphamide: a four-year experience with twenty-four patients.

BACKGROUND: Renal involvement in systemic lupus erythematosus commonly leads to renal failure and death. We conducted a study to evaluate the efficacy and side effects of intermittent intravenous treatment with cyclophosphamide of patients with lupus nephritis. METHODS: Twenty-four patients with lupus nephritis were recruited at Tri-Service General Hospital from 1988 to 1992. Cyclophosphamide was administered intravenously monthly for three months, and then every three months. 24-hour urinary protein, creatinine clearance, serum creatinine, blood urea nitrogen, C3 and C4 levels, serum albumin, hemoglobin, and dosage of prednisolone were recorded before each treatment. During treatment, the side effects were monitored. RESULTS: Two patients progressed to renal failure within one year and one patient after three years. Fifteen patients completed therapy for one year. Among these 15 patients, the levels of hemoglobin, serum albumin, and C3 significantly increased at six months, then became stable; the level of C4 increased at 12 months. In contrast, the dosage of prednisolone decreased significantly at six months. There was no significant difference of creatinine clearance, 24-hour urinary protein, serum creatinine, and blood urea nitrogen before and after treatment. The most common side effects were nausea and vomiting. No severe side effect necessitated discontinuing therapy with cyclophosphamide. CONCLUSIONS: Intermittent intravenous therapy in lupus nephritis with cyclophosphamide can significantly increase levels of hemoglobin, serum albumin, C3 and C4, and keep renal function stable. Poor response was found in a subset of patients. The side effects were mild in the present study.

Adult↗

PubMed1994

Lupus nephritis: an analysis of 70 cases.

BACKGROUND: The influence of renal morphology and clinical factors at biopsy on the development of renal failure in patients with lupus nephritis remain controversial. We investigated the relation between renal histologic finding and clinical manifestations, and evaluated prognostic factors and short-term prognosis among patients with lupus nephritis. METHODS: Seventy patients with lupus nephritis were enrolled in the study from 1982 to 1992 at the Tri-Service General Hospital. Renal biopsy specimens from these patients were assessed according to the World Health Organization (WHO) classification, activity and chronicity indices, and clinical parameters. Survival was analyzed by using the day of renal biopsy as the starting point. The end point of renal survival was the date when patient started to receive regular hemodialysis. RESULTS: In pathological finding, one patient was grouped as Class I (1.4%); 14, as Class II (20%); 15, as Class III (21.4%); 29, as Class IV (41.4%); 9, as Class V (12.9%), and 2, as Class VI (2.9%). The scores of activity indices were highest in Class IV. The blood levels of C3 and C4 in Class V were significantly higher than Class IV. The values of BUN and 24-hour urine protein in Class II were significant lower than Class IV. Patients who progressed to renal failure had significantly higher numbers of death, higher serum creatinine and chronicity index, less creatinine clearance, and higher numbers of hypertension at the time of biopsy. Nephrotic syndrome was not associated with renal failure. Patient and renal survivals did not differ among WHO classifications. The patient and renal survivals were 84%, 60% and 85%, 72% at one and five years, respectively. Seventeen patients (24.2%) progressed to end-stage renal disease and 21 patients (30%) died during the study period. The leading causes of death were sepsis and renal failure. CONCLUSIONS: WHO classification had little correlation with clinical and renal information. At the time of biopsy the elevated serum creatinine and hypertension were good predictors for end-stage renal disease. Poor patient and renal survivals were found in this study.

Adolescent↗

PubMed1993

[Preventive chemotherapy after transurethral prostatectomy: a randomized study].

The usefulness of preventive chemotherapy was studied in transurethrally prostatectomized patients with no prior urinary tract infections. They were divided into two groups (A and B) randomized by the envelope method. A was administered intravenously piperacillin (PIPC) 2 g once after surgery, and twice on the following day. B was similarly administered PIPC intravenously, followed by oral administration of tosufloxacin tosilate (TFLX) 300 mg twice daily from the second to the fifth day. Of the total of 135 cases, 104, 45 in A and 59 in B, conformed to the patient standards established for analysis. Efficacy was assessed by the primary physician and also according to a unified standard in which the onset of a post-surgical infection and a bacteriuria of 10(4) or greater CFU/ml observed ten days after surgery were regarded as ineffective. An intergroup statistically significant difference was not observed in the efficacy rate assessed by the primary physician. However, according to the unified standard assessment, B showed a significantly higher efficacy rate (88.1%) than A (62.2%). The administration of TFLX following PIPC was useful. With an indwelling catheter, B exhibited a significantly greater efficacy rate when the retention period was four days or longer. The efficacy was greater in both groups if lavage was not performed, and this effect was greater in A. Consequently, the administration of TFLX was considered more useful for long-term indwelling catheter cases. Neither serious side effects, nor clinical test abnormalities were observed in this study.

Aged↗

PubMed1993

[The influence of Chinese traditional medicine on the production and activity of interleukin 1 (IL-1)].

Interleukin 1 (IL-1) is a cytokine closely related to the pathogenesis of inflammation and chronic destructive changes in rheumatoid arthritis (RA). Analysis of the effect of antirheumatic drugs on IL-1 production and activity is of great importance in exploring the therapeutic mechanism of RA. The purpose of the present study was to investigate the effect of Chinese herbs (10 prescription and 15 single drugs), which was often used in the treatment of RA, on the production and activity of IL-1. The production of IL-1 was tested through human monocytes stimulated with zymosan and measured by ELISA method; the activity of IL-1 was measured by its effect on the proliferation of murine thymocytes. The results showed that Tripterygium Wilfordii Hook, Tripterygil Hyhoglauci Tetrandrine significantly inhibited both of IL-1 production and IL-1 activity; while Aconiti Tuber, Ephedrae Herba, Atractyloidis Rhizoma, Atractyloidis Lanceae Rhizoma, Ledebouiellae Radix slightly inhibited IL-1 activity but not affecting IL-1 production. The ten prescriptions had no inhibitory effect on both of IL-1 production and IL-1 activity.

Animals↗

PubMed1992

Inhibition of tonoplast ATPase by 2',3'-dialdehyde derivative of ATP.

The 2',3'-dialdehyde derivative of ATP (dial-ATP) has been shown to be an affinity label for the ATP binding site of the H(+)-ATPase from tonoplast of etiolated mung bean seedlings (Vigna radiata L.). The dial-ATP caused marked inactivation of enzymatic activities of both membrane-bound and soluble ATPase and its associated proton translocation. The inactivation was reversible, but could be stabilized by NaBH(4). The sodium dodecyl sulfatepolyacrylamide gel electrophoresis pattern revealed that the dial-ATP binding site was in the large (A) subunit of ATPase. The inhibition could be substantially protected by its physiological substrate ATP, pyrophosphate, and nucleotides in the decreasing order: ATP > pyrophosphate > ADP = AMP > GTP > CTP = UTP. A Lineweaver-Burk plot showed that the mode of inhibition was competitive with respect to ATP. Loss of ATPase activity followed pseudo-first order kinetics with a K(i) of 4.1 millimolar, a minimum inactivation half-time of 20 seconds, and a pseudo-first order rate constant of 0.035 s(-1). The double logarithmic plot of apparent rate constant versus dial-ATP concentration gave a slope of 0.927, indicating that inactivation results from reaction of at least one lysine residue at the catalytic site of the large subunit. Labeling studies with [(3)H]dial-ATP indicate that the incorporation of approximately 1 mole of dial-ATP per mole ATPase is sufficient to completely inhibit the ATPase. A working model of nonequivalent subunits for enzymatic mechanism of vacuolar ATPase is suggested.

Journal Article↗

PubMed1992

[A case of advanced seminoma treated effectively with single agent carboplatin therapy].

Cisplatin has played a major role in the treatment of germ cell tumors. However, it causes renal damage, severe nausea and vomiting. It is also neurotoxic and ototoxic. Carboplatin is an analog of cisplatin which, does not cause renal damage at therapeutic doses. It is not neurotoxic or ototoxic and it produces less gastrointestinal toxicity than cisplatin. We used carboplatin alone as an initial chemotherapy in a 36-year-old man with stage IIB seminoma. Following left radical orchiectomy the patient received 4 courses of carboplatin chemotherapy. After the first course of chemotherapy, tumor markers (LDH, beta-HCG) returned to the normal range. After 4 courses, the size of the retroperitoneal metastases was significantly reduced. The toxicity of 4 courses of carboplatin chemotherapy was generally milder than that of cisplatin-based combination chemotherapies such as PVB or VAB-6. There were no episodes of septicemia, thrombocytopenic bleeding or renal deterioration. The patient did not suffer from alopecia, neuropathy, symptomatic hearing loss, severe nausea or vomiting. Nine months after the completion of carboplatin chemotherapy, the patient remains well and free from disease progression. This case strongly suggests that single agent carboplatin therapy could be an effective and less-toxic treatment for advanced seminoma.

Adult↗

PubMed1990

An essential arginyl residue in the tonoplast pyrophosphatase from etiolated mung bean seedlings.

Tonoplast membrane of etiolated mung bean (Vinga radiata. L.) seedlings contained H(+)-translocating pyrophosphatase (PPase). Modification of tonoplast vesicles and partially purified PPase from etiolated mung bean seedlings with arginine-specific reagents, phenylglyoxal (PGO) and 2,3-butanedione (BD), resulted in a marked decline in H(+)-translocating PPase activity. The half-maximal inhibition was brought about by 20 millimolar PGO and 50 millimolar BD for membrane bound and 1.5 millimolar PGO and 5.0 millimolar BD for soluble PPase, respectively. The substrate, Mg(2+)-pyrophosphate, provided partial protection against inactivation by these reagents. Loss of activity of partially purified PPase followed pseudo-first order kinetics. The double logarithm plots of pseudo-first order rate constant versus reagent concentrations gave slopes of 0.88 (PGO) and 0.90 (BD), respectively, suggesting that the inactivation may possibly result from reaction of at least one arginyl residue at the active site of H(+)-translocating PPase.

Journal Article↗

PubMed1990

Interferon production from peripheral blood, synovial fluid, and synovial tissue lymphocytes in patients with rheumatoid arthritis and ankylosing spondylitis.

A previous study demonstrated that interferon was present in the serum of 30% of the patients with systemic lupus erythematosus (SLE), which was significantly higher than the 4.5% found in normal controls. We also recently reported that interferon production was deficient from SLE mononuclear cells, which has been attributed to immunodeficiency of the lymphocytes. In this study, interferon measurement included lymphocytes obtained from peripheral blood (PB), synovial fluid (SF) and synovial tissue (ST) in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). PB from normal subjects (NS) was used as a control. The results showed with PHA stimulation, that the interferon level in PBL (L = lymphocyte) in NS (70.0 +/- 67.5) was significantly higher when compared with PBL in RA (27.9 +/- 21.6). However, there was no difference between PBL in NS and AS. With ConA stimulation, the interferon level was significantly higher in the PBL of NS (130 +/- 59) and as compared with the PBL in RA (83.6 +/- 53.5). The SFL in RA (67.8 +/- 31.1) and the STL in RA (77.2 +/- 93.2) were also significantly different. It is concluded that interferon production was deficient not only in PBL in RA, but also in SF and STL in RA. The reduced interferon production from PB, SF and ST lymphocytes in RA patients may be due to previous release or immunodeficiency. Lymphocyte interferon production was normal in AS, which suggests that the lymphocyte abnormality between RA and AS may be different.

Adult↗

PubMedDate not supplied

Cytokines and cell surface markers in prediction of cardiac allograft rejection.

Endomyocardial biopsy is generally used to quantify heart allograft rejection and guide immunotherapy. Biopsy, however, is invasive, costly, and risky. Since rejection requires lymphocyte activation, the purpose of this study was to assess alternative methods to evaluate rejection dynamics by investigating serum levels of cytokines and cell surface markers after heart transplantation. Interleukin-2-receptor bearing CD4+T (IL-2R/CD4) cell levels were higher in the peripheral blood of human transplant recipients with rejection grade 2 (p < 0.02). HLA-DR/CD3 levels were somewhat higher in rejection grade 2. There was no correlation between biopsy scores and serum levels of tumor necrosis factor (TNF-alpha), IL-2, or percentage of T cell, NK cell, B cell, CD4+T cell, CD8+T cell, HLA-DR/CD4, HLA-DR/CD8, IL-2R/CD3, IL-2R/CD8. Interleukin-1 (IL-1 beta) was not detectable in all of the samples. The current studies suggest that monitoring lymphocyte IL-2R/CD4 and HLA-DR/CD3 levels is useful in predicting cardiac transplant rejection.

Adult↗