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Biomedical subjects

J Su

Publications and source records attributed to J Su.

At least 127 records · Page 7Linked to original sources
PubMed1995

[Isolation and reassociation of acetogen and methanogen in a syntrophobic coculture degrading butyrate anaerobically].

Anaerobic coculture BF2 which degraded butyrate into acetate and produced methane was isolated from granular methanogenic sludge. The coculture is associated syntrophically the Syntrophomonas subsp. saponavida strain CF2 with Methanobacterium formicicum strain MF2 and appeared to degraded C4 approximately C18 fatty acids including isobutyrate. The optimal temperature and pH for growth was 37 degrees C and 7.7 respectively. The strain CF2 was obtained in pure culture with crotonate as substrate and produces acetate and butyrate. The doubling time of strain CF2 in crotonate media was about 20 hours. Strain CF2 is Gram negative, slightly curved 0.2 approximately 0.3 x 2.0 approximately 3.0 micron with round ends, motile by lateral flagellation at the concave side, non sporeforming. With a hydrogen scavenging organism, such as Methanospillum hungatei JF1, Methanobacterium formicicum 1535, Methanobrevibacterium bryantii 1125 and Desulfovibrio sp. B11, the strain CF2 paired up and the defined coculture degraded butyrate to acetate. When the strain CF2 associated with the original accompanist, Methanobacterium formicius strain MF2, the reassociated couculture degraded butyrate to acetate and produced methane again.

Butyrates↗
PubMed1994

Protease nexin-1, a potent thrombin inhibitor, is reduced around cerebral blood vessels in Alzheimer's disease.

The clotting protease thrombin might contribute to the pathophysiology of central nervous system (CNS) injury and certain diseases by its ability to retract processes on neurons and astrocytes and to stimulate astrocyte proliferation. Protease nexin-1 (PN-1) is a 43 kDa thrombin inhibitor found predominantly in the brain where much of it resides around capillaries and large blood vessels. This location of PN-1 prompted the hypothesis that it may play a protective role against extravasated thrombin released following cerebrovascular injury or under certain pathological conditions. Recent studies indicated that the levels of PN-1 are markedly reduced in the postmortem brains of patients with Alzheimer's disease (AD). It was suggested that this reduction in PN-1 levels was due to the sequestration of PN-1 by extravasated thrombin. In the present study we examined the specific nature of this reduction by immunohistochemical staining of sections from control and AD brains using PN-1 specific antibodies. We show that the levels of PN-1 immunoreactivity around blood vessels and the number of blood vessels exhibiting PN-1 immunoreactivity were markedly reduced in the brains of patients with AD compared to age-matched controls; this reduction was reflected by a decrease in the levels of PN-1 activity and PN-1 protein. Thus an imbalance between PN-1 and thrombin may be a contributing factor in the pathology of AD.

Aged↗
PubMed1994

Receptor tyrosine phosphatase R-PTP-alpha is tyrosine-phosphorylated and associated with the adaptor protein Grb2.

Receptor tyrosine phosphatases (R-PTPases) have generated interest because of their suspected involvement in cellular signal transduction. The adaptor protein Grb2 has been implicated in coupling receptor tyrosine kinases to Ras. We report that a ubiquitous R-PTPase, R-PTP-alpha, is tyrosine-phosphorylated and associated in vivo with the Grb2 protein. This association can be reproduced in stably and transiently transfected cells, as well as in vitro using recombinant Grb2 protein. Association requires the presence of an intact SH2 domain in Grb2, as well as tyrosine phosphorylation of R-PTP-alpha. This observation links a receptor tyrosine phosphatase with a key component of a central cellular signalling pathway and provides a basis for addressing R-PTP-alpha function.

Adaptor Proteins, Signal Transducing↗
PubMed1994

Treatment of stage IE primary lymphoma of bone.

PURPOSE: A retrospective analysis was performed to assess the efficacy of various treatments of Stage IE primary non-Hodgkins lymphoma of bone. METHODS AND MATERIALS: Sixty-three patients with Stage IE primary non-Hodgkins lymphoma of bone (single osseous focus) were seen at our institution between the years 1970 and 1989. Information was obtained regarding each patients' presentation and clinical course. The histology was reviewed in all patients. Modern immunohistochemical stains were performed on each case with available paraffin-embedded tissue. RESULTS: The histologic classification of the tumors was as follows: 43 diffuse large cell, 13 diffuse mixed cell, 3 small noncleaved, and 4 unclassified. The most common presenting symptom was pain (97%) and the following bony sites were involved: 36 long bone, 9 flat bone, 13 spine, and 5 pelvis. Of the 63 cases, 50 were treated with radiation alone, 10 with chemotherapy and radiation, 2 with chemotherapy alone, and 1 with surgery alone. Univariate analysis revealed a suggestion of an improved 5-year disease-free survival for patients treated with chemotherapy and radiation vs. radiation alone (90% vs. 57% respectively, p = .08). Multivariate analysis (controlling for extent of initial evaluation, extent of pathological evaluation and other potential prognostic factors) showed that neither treatment resulted in superior outcome with respect to disease-free survival, disease specific survival, or overall survival, however, doses of radiation greater than 4000 cGy resulted in improved overall survival compared to lower doses (p = 0.01). CONCLUSION: This study supports the use of primary RT (> 4000 cGy) for Stage IE PLB, however, the addition of chemotherapy to the radiotherapeutic management may decrease the initial relapse rate of some patients. Future studies should address this question.

Adolescent↗
PubMed1994

Effects of the calcium channel blockers, diltiazem and Ro 40-5967, on systemic haemodynamics and plasma noradrenaline levels in conscious dogs with pacing-induced heart failure.

1. Calcium channel blockers increase cardiovascular morbidity and mortality in patients with left ventricular dysfunction. These adverse effects are probably related to the negative inotropic effect of calcium channel blockers and/or a neurohormonal activation. 2. The present study was designed to examine, in conscious dogs, the acute haemodynamic and sympathetic effects of diltiazem and Ro 40-5967 (a novel calcium channel blocker) in the control state and in heart failure. 3. Thirteen dogs were instrumented with a micromanometer and an aortic catheter. After completion of experiments in the control state, heart failure was induced by right ventricular pacing (250 beats min-1, 3 weeks). Diltiazem and Ro 40-5967 were given intravenously (0.8 mg kg-1 and 1.0 mg kg-1 respectively). Cardiac output was measured by a thermodilution technique. 4. In the control state, both agents decreased similarly mean aortic pressure with significant increases in heart rate, cardiac output (both +1.0 l min-1 and P < 0.001) and plasma noradrenaline (both +55%) without changes in left ventricular dP/dtmax. In heart failure, for matched decreases in mean aortic pressure, neither diltiazem nor Ro 40-5967 changed heart rate significantly; diltiazem decreased cardiac output (-0.3 l min-1, P < 0.02) and dP/dtmax (-14%, P < 0.001) while Ro 40-5967 still increased cardiac output (+0.3 l min-1, P < 0.02) although the increased amount was smaller than in the control state. Plasma noradrenaline level was increased more during diltiazem infusion (+120%) than during Ro 40-5967 infusion (+38%, P < 0.001). 5. Diltiazem and Ro 40-5967 have similar haemodynamic and sympathetic effects in the control state.Heart failure alters haemodynamic and sympathetic responses to both calcium channel blockers but the magnitude of the alteration appears to be different. Diltiazem exerts a depressant effect on cardiac function which cannot be overcome by its vasodilator effect and sympathetic stimulation, while Ro 40-5967 has little effect on cardiac function. These data suggest that novel calcium channel blockers with less depressant effect may not be detrimental in heart failure.

Animals↗
PubMed1994

[A fungus-derived novel nucleoside transport inhibitor potentiates the activity of antitumor drugs].

Antibiotic C3368-B (CB), identified as 3,9-dihydroxy-1-methoxy-7-methylanthraquinone, is produced by a fungus strain, Chrysosporium verrucosum Tubaki, isolated from a soil sample collected from Antarctica. CB was found to be a highly-active nucleoside transport inhibitor. By radiolabelled nucleoside assay, CB was shown to markedly inhibit thymidine and uridine transport in Ehrlich carcinoma cells, with IC50 values of 7.5 and 9.6 mumol.L-1 respectively. CB showed fairly low cytotoxicity to tumor cells. The IC50 values for epidermoid cancer KB cells and hepatoma BEL-7402 cells in clonogenic assay was 77 and 69 mumol.L-1. At relatively noncytotoxic concentrations, CB markedly enhanced the cytotoxicity of methotrexate, 5-fluorouracil, mitomycin C against KB cells and BEL-7402 cells. CB was also found to partly reverse the multi-drug resistance to vincristine and actinomycin D in leukemia L1210/MDR cells. The IC50 values were reduced by 4.9-fold (1.75 to 0.36 mumol.L-1) for vincristine and 3.3-fold (0.39 to 0.12 mumol.L-1) for actinomycin D. These results suggest that CB, as a newly-found nucleoside transport inhibitor, may be potentially useful in cancer chemotherapy.

Animals↗
PubMed1994

[Analytical method of guiqi mixture and its main ingredient Astragalus root].

Chuanxiog Rhizome, Chinese Angelica Root and Scrophularia Root in Guiqi mixture have been identified by TLC. A TLC-densitometric method for determining astragalosied in the patent medicine and its main ingredient Astragalus Root has been established. This method is sensitive and highly reproducible, with RSD under 3.0% and recovery over 98%.

Chromatography, Thin Layer↗
PubMed1993

Malignant tracheoesophageal fistula in patients with esophageal cancer.

BACKGROUND: Patients with esophageal cancer and a malignant tracheoesophageal fistula (TEF) have an extremely poor prognosis. Additionally, these patients often are denied treatment with radiation therapy because there is concern that these treatments may increase the size and associated problems of the TEF. METHODS: To determine the appropriate treatment (use of radiation therapy) for patients with esophageal cancer and malignant TEF, a review was performed of all such cases seen at the Mayo Clinic between 1971 and 1991. RESULTS: Between 1971 and 1991, 41 patients with malignant TEF arising as a result of esophageal cancer were seen at the Mayo Clinic in Rochester. Twenty-eight of these cancers were locally recurrent, and this group of patients had a uniformly poor outcome (median survival time, 1.4 months). Thirteen patients had a malignant TEF and had not received previous treatment for their esophageal cancer. The median survival length was 4 months for this group of patients. Of the 41 patients in this study, 10 received radiation therapy for their malignant TEF (30-66 Gy). The median survival length of this group of patients was 4.8 months. Six of these 10 patients died of metastatic disease (median survival length, 9 months), and there was no evidence of progression of the local tumor. Four of these 10 patients died of local progression of the malignancy (median survival length, 3 months). CONCLUSIONS: Radiation therapy did not increase the severity of the TEF. The authors conclude that radiation therapy can be administered safely in patients with TEF resulting from esophageal cancer. In some patients, radiation treatment may contribute to stabilization of the local tumor process (60% of patients treated with radiation therapy died of metastatic disease without local progression of tumor); however, all patients in this study eventually died of esophageal cancer.

Adenocarcinoma↗
PubMed1993

The 5q- syndrome: a single-institution study of 43 consecutive patients.

A favorable prognosis and a low rate of leukemic transformation has been attributed to the 5q- syndrome, a myelodysplastic syndrome (MDS) characterized by macrocytic anemia, hypolobulated micromegakaryocytic hyperplasia, and an interstitial deletion of chromosome 5. We examined the characteristics and outcome of 43 consecutive patients in our institution strictly defined by morphologic criteria and a solitary 5q- cytogenetic defect. The median age at diagnosis was 68 years, with a clear female predominance (7:3). Eighty percent of the patients were red blood cell transfusion-dependent at diagnosis and all untransfused patients had macrocytic indexes. In contrast, significant neutropenia or thrombocytopenia was rare. The French-American-British (FAB) class distributions were RA (72%), RARS (7%), RAEB (16%), and RAEB-IT (5%). At a median follow-up of 31 months, 56% of the patients survive, with a projected median survival of 63 months. The incidence of acute leukemia was 16% and was uniformly fatal. Clinical hemosiderosis occurred in 28% of the patients, resulting in two deaths. Neither survival nor the risk of leukemic transformation was predictable from initial clinical parameters, including FAB classification, Bournemouth score, and degree of aneuploidy. The lack of significant neutropenia and thrombocytopenia seemed to account for a very low incidence of infection and bleeding resulting in a prognosis equal or superior to historical patients with MDS. Therapeutic endeavors, including the use of corticosteroids, androgens, cis-retinoic acid, pyridoxine, and danazol, were largely unsuccessful.

Acute Disease↗
PubMed1993

Treatment of ovarian cancer in elderly women. Mayo Clinic-North Central Cancer Treatment Group studies.

BACKGROUND: With a 25% reduction in ovarian cancer mortality rate between 1973 and 1988 among younger American women, the overall control of ovarian cancer appeared to be improving. Unfortunately, American women older than 65 years of age experienced a 16% increase in mortality from this disease during that same interval. We examined our therapeutic outcomes following systemic chemotherapy administered to women of various ages accepted for treatment on phase III Mayo Clinic and North Central Cancer Treatment Group protocols between 1974 and 1988. METHODS: Three randomized studies of chemotherapy for Stage III and IV epithelial ovarian carcinoma were analyzed for possible effects of age on the results of treatment. All of the patients, regardless of age, had been enrolled and treated according to standard accession and dosage adjustment criteria. RESULTS: Among our 383 patients, 107 (28%) were 65 years of age or older. Although the elderly women tolerated our five different chemotherapy regimens nearly as well as did the younger patients, we found that progressively greater dose reductions were required for treatment continuation with advancing age between groups aged 44 years or younger, 45-64 years, and 65 years and older. When nonserous histology, Stage IV, ECOG performance status above 0, tumor grade above 1, and extent of residual disease greater than 2 cm were considered, our Cox model analysis yielded no firm evidence that age 65 years and older per se (P = 0.58) was a negative prognostic factor for survival. CONCLUSIONS: Elderly women eligible for randomized clinical trials tolerated Stage III and IV epithelial ovarian carcinoma and its chemotherapy nearly as well as did younger women. Among this population of women accepted for study in our three clinical trials, age 65 years and older per se was not proven to be a negative prognostic factor in our multivariate analysis.

Aged↗
PubMed1993

Prognostic features and survival in young adults with early/intermediate chronic lymphocytic leukemia (B-CLL): a single institution study.

Information regarding natural history and prognostic factors for early/intermediate B-cell chronic lymphocytic leukemia (B-CLL) in young adults is limited. We analysed 62 young adults (< or = 50 years old) with early/intermediate B-CLL who were seen at our institution during initial diagnosis over a 15-year period. These patients had been followed for a median duration of 7 years. Median age for the entire group was 44 years and 72% were > or = 40 years old. Actuarial median survival from initial diagnosis for the entire group was 140 months. Upon univariate analysis, significant survival advantage was observed in patients with Rai stages 0 and 1 versus stage II disease (median survival 140 versus 60 months, p = 0.01) and in those with lymphocyte doubling time (LDT) of > 1 year versus < or = 1 year (median survival 150+ versus 94 months, p = 0.06). Similarly there was a trend towards longer survival in patients with a leucocyte count of < or = 50,000/microliters when compared to those with higher counts although the difference was not statistically significant. The bone marrow infiltration pattern was not prognostically useful. Upon multivariate analysis, only Rai stage and LDT were prognostically useful. Patients who did not respond to initial therapy with alkylating agents had the worst prognosis, with a median survival of only 19 months. Assessment of presenting clinical stage, LDT, and degree of initial treatment response may prompt earlier consideration of alternative therapeutic modalities such as purine nucleoside analogs or bone marrow transplantation in younger patients with early/intermediate B-CLL.

Adolescent↗
PubMed1993

[Evaluation of routine gas determinations in umbilical cord blood at cesarean section].

From 1985 to 1989, analysis of the umbilical cord blood gas in 546 cases of cesarean section delivery under spinal anesthesia was carried out to evaluate its relationship with neonatal asphyxia, and the following results were obtained. (1) The UApH of a normal newborn with an Apgar score > 7 was 7.28 +/- 0.04. Acidosis occurred in 33.3% of the infants born with an Apgar score < 7, but the incidence was only 3.9% in those with an Apgar score > 7. Sixteen% of the acidosis was metabolic and 84% belonged to the mixed type. The UApH and Apgar scores were most significantly related. (2) The abnormal UVpH was 4.9% (< M - 2SD). (3) There was no significant difference in UApH between cesarean section performed before and after the onset of labor. (4) The short term morbidity included: one death, 2 cases of convulsions, 2 cases of cerebral edema, and one case of periventricular leukomalacia. (5) The long term morbidity in the 29 cases referred to NICU included: 18 cases of normal growth, 2 cases of severe cerebral palsy, 3 cases of mild cerebral palsy, and 6 cases of mental retardation. (6) In view of the long term morbidity of the newborn, as seen in the correlation between the Apgar score and UApH, it was considered that, the critical points in neonatal asphyxia were Apgar score < or = 3 and UApH < 7.10. My results suggested that the umbilical cord blood gas analysis was helpful for the diagnosis of neonatal asphyxia, and the prognosis of the newborn.

Acidosis↗
PubMed1992

A phase II study of recombinant human alpha-interferon in advanced hormone-refractory prostate cancer.

To determine the efficacy of recombinant human leukocyte alpha-interferon (IFL-RA) in advanced hormone-refractory prostate cancer, the authors treated 40 patients with IFL-RA administered intramuscularly at a dose of 10 x 10(6) U/m2 three times weekly. Toxicity was substantial and necessitated at least a 50% dose reduction in all but five patients during the first 1-2 months of therapy. No responses were observed in patients with bone metastases, but complete and partial regression of nodal disease were observed in two patients with extraosseous disease (overall response rate, 5%; 95% confidence interval, 0.64-17.75%). The authors conclude that IFL-RA cannot be recommended at this dose and schedule in patients with advanced prostate cancer, but additional study of its use in patients with nodal disease may be warranted.

Adenocarcinoma↗
PubMed1992

Phase II trial of intravenous hexamethylmelamine in patients with advanced ovarian cancer.

A Phase II trial of an intravenous preparation of Hexamethylmelamine was performed in ovarian cancer. Patients who had received prior Platinum based chemotherapy and had measurable disease were eligible. Among 15 evaluable patients, there were no objective responses. Two patients did show clinical and laboratory evidence of improvement. Toxicity was predominantly nausea and vomiting with minimal other toxicity. This intravenous form of Hexamethylmelamine has not shown meaningful activity in ovarian cancer patients who have failed prior platinum treatment.

Altretamine↗
PubMed1992

Splenectomy in advanced chronic lymphocytic leukemia: a single institution experience with 50 patients.

PURPOSE: To assess the efficacy of splenectomy in the treatment of refractory cytopenias associated with advanced chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: The histories of 57 patients with CLL who underwent splenectomy at the Mayo Clinic between 1975 and 1991 were retrospectively reviewed. Of the 57 patients, 50 underwent splenectomy for reasons directly related to their disease process such as cytopenias or symptomatic splenomegaly. The histories from these 50 patients were studied to assess the response to splenectomy and the operative morbidity and mortality. RESULTS: Ninety-four percent of patients were in Rai stage III or IV with extensive marrow infiltration, massive splenomegaly, and cytopenias refractory to chemotherapy. A positive response to splenectomy was defined at 3 months of follow-up as: (1) a hemoglobin level of 11 g/dL or greater in a patient with a preoperative value less than 11 g/dL; or (2) a platelet count of 100 x 10(3)/mm3 or greater in a patient with a preoperative value less than 100 x 10(3)/mm3. A positive response was achieved in 77% of patients with anemia, 70% of patients with thrombocytopenia, and 64% of patients with both anemia and thrombocytopenia. The response was sustained at 1 year of follow-up in 86%, 84%, and 85% of the patients, respectively. Postoperative transfusion requirements decreased correspondingly. The operative morbidity was 26%, and the operative mortality was 4%. The mean duration of hospitalization was 9.8 days (median: 9 days; range: 5 to 24 days). The actuarial median survival after splenectomy was 41 months in responders and 14 months in nonresponders. We found no preoperative parameters that were clearly predictive of a poor hematologic response. In particular, outcome was not affected by preoperative spleen size or the degree of marrow infiltration by CLL. All patients with symptomatic splenomegaly had an improved sense of well-being. CONCLUSION: In this, the largest single institution study to date, we found splenectomy to be efficacious in providing durable remissions of refractory cytopenias and in relieving symptomatic splenomegaly in the majority of patients with CLL. The procedure is associated with a low perioperative mortality. Although the impact on survival is uncertain, the improved peripheral blood counts may allow the administration of adequate doses of myelosuppressive chemotherapy.

Actuarial Analysis↗
PubMed1992

[Kinetics of pharmacologic effects of radix Aconiti Lateralis Preparata and sini decoction].

In the study of analgesic action of Radix Aconiti Lateralis Preparata and Sini Decoction hot-plate method was used and the time-effect relationship was determined. The biological half-lives were 11.05 h and 6.84 h respectively. In the study of the effect on inflammation induced by egg white in the ankle joints of rats, the method of complement ED50 was used. The residual rates of the dosages after an interval of 6 hours were 0.60 and 0.69, and the biological half-lives were 8.11 h and 11.35 h respectively.

Animals↗