ABSTRACT
Background: Pheochromocytoma, the great masquerader, can have a varied spectrum of clinical manifestations. It can often cause a diagnostic challenge despite the availability of modern investigation modalities. Case: We present the case of a 38-year-old male who presented with uncontrolled hypertension for the past 10 years and heart failure for one year. The diagnosis of pheochromocytoma was missed in the initial setting, leading to a biopsy of the retroperitoneal mass. Fortunately, the patient survived the procedure. Subsequently, with the involvement of a multi-disciplinary team, he was optimized for surgery under strict cardiac monitoring. After the complete excision of the tumour, he showed significant improvement not only in his clinical symptoms but also in his cardiac status. Conclusions: This case emphasizes the age-old medical phrase of 'Primum non nocere or first, do no harm'. Any invasive procedure in a pheochromocytoma can lead to a massive release of catecholamines causing a hypertensive crisis, pulmonary oedema, and even cardiac arrest. Any young patient presenting with hypertension or heart failure should be investigated for secondary causes. Cardiomyopathy due to pheochromocytoma is because of catecholamine overload and usually reverses or improves after curative surgery.
ABSTRACT
BACKGROUND: Targeted therapies have transformed clinical management of advanced biliary tract cancer (BTC). Cell-free DNA (cfDNA) analysis is an attractive approach for cancer genomic profiling that overcomes many limitations of traditional tissue-based analysis. We examined cfDNA as a tool to inform clinical management of patients with advanced BTC and generate novel insights into BTC tumor biology. PATIENTS AND METHODS: We analyzed next-generation sequencing data of 2068 cfDNA samples from 1671 patients with advanced BTC generated with Guardant360. We carried out clinical annotation on a multi-institutional subset (n = 225) to assess intra-patient cfDNA-tumor concordance and the association of cfDNA variant allele fraction (VAF) with clinical outcomes. RESULTS: Genetic alterations were detected in cfDNA in 84% of patients, with targetable alterations detected in 44% of patients. Fibroblast growth factor receptor 2 (FGFR2) fusions, isocitrate dehydrogenase 1 (IDH1) mutations, and BRAF V600E were clonal in the majority of cases, affirming these targetable alterations as early driver events in BTC. Concordance between cfDNA and tissue for mutation detection was high for IDH1 mutations (87%) and BRAF V600E (100%), and low for FGFR2 fusions (18%). cfDNA analysis uncovered novel putative mechanisms of resistance to targeted therapies, including mutation of the cysteine residue (FGFR2 C492F) to which covalent FGFR inhibitors bind. High pre-treatment cfDNA VAF was associated with poor prognosis and shorter response to chemotherapy and targeted therapy. Finally, we report the frequency of promising targets in advanced BTC currently under investigation in other advanced solid tumors, including KRAS G12C (1.0%), KRAS G12D (5.1%), PIK3CA mutations (6.8%), and ERBB2 amplifications (4.9%). CONCLUSIONS: These findings from the largest and most comprehensive study to date of cfDNA from patients with advanced BTC highlight the utility of cfDNA analysis in current management of this disease. Characterization of oncogenic drivers and mechanisms of therapeutic resistance in this study will inform drug development efforts to reduce mortality for patients with BTC.
Subject(s)
Bile Duct Neoplasms , Biliary Tract Neoplasms , Cell-Free Nucleic Acids , Humans , Cell-Free Nucleic Acids/genetics , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins p21(ras)/genetics , Bile Duct Neoplasms/genetics , High-Throughput Nucleotide Sequencing , Mutation , Biliary Tract Neoplasms/drug therapy , Biliary Tract Neoplasms/genetics , Biliary Tract Neoplasms/pathologyABSTRACT
Management of biliary tract cancers (BTCs) is rapidly evolving. Curative management relies on surgical resection followed by adjuvant capecitabine for cholangiocarcinoma and gallbladder cancers. Unfortunately relapse rate remains high, and better adjuvant strategies are urgently required. A majority of patients are diagnosed with advanced disease, when chemotherapy with cisplatin and gemcitabine followed by second-line 5-FU and oxaliplatin /irinotecan is the cornerstone of treatment for most patients in the absence of targetable alterations. Targeted therapies, including therapies for tumours with fibroblast growth factor receptor-2 (FGFR-2) fusions, isocitrate dehydrogenase-1 (IDH-1) mutations, B-Raf proto-oncogene serine/threonine kinase (BRAF) V600E mutations, neurotrophic tyrosine receptor kinase (NTRK) fusions, Human epidermal growth factor-2 (HER-2) amplifications, and/or microsatellite instability are rapidly changing the treatment paradigm for many patients with advanced BTC, especially for patients with intrahepatic cholangiocarcinoma. Because of this, molecular profiling should be considered early on patients pathway to allow adequate planning of therapy. Ongoing research is likely to clarify the role of immunotherapy, liver-directed therapy, and liver transplant for BTCs in the future.
Subject(s)
Bile Duct Neoplasms , Biliary Tract Neoplasms , Cholangiocarcinoma , Bile Duct Neoplasms/diagnosis , Bile Duct Neoplasms/genetics , Bile Duct Neoplasms/therapy , Bile Ducts, Intrahepatic/metabolism , Bile Ducts, Intrahepatic/pathology , Biliary Tract Neoplasms/diagnosis , Biliary Tract Neoplasms/genetics , Biliary Tract Neoplasms/therapy , Cholangiocarcinoma/diagnosis , Cholangiocarcinoma/genetics , Cholangiocarcinoma/therapy , Humans , Neoplasm Recurrence, LocalABSTRACT
BACKGROUND: Futibatinib is an oral, irreversible, highly selective fibroblast growth factor receptor (FGFR)1-4 inhibitor with potent preclinical activity against tumors harboring FGFR aberrations. This first-in-human, phase I dose-escalation trial (NCT02052778) evaluates the safety and pharmacokinetics/pharmacodynamics of futibatinib in advanced solid tumors. PATIENTS AND METHODS: Following a standard 3+3 dose-escalation design, eligible patients with advanced solid tumors refractory to standard therapies received 8-200 mg futibatinib three times a week (t.i.w.) or 4-24 mg once daily (q.d.). RESULTS: A total of 86 patients were enrolled in the nine t.i.w. (n = 42) and five q.d. cohorts (n = 44); 71 patients (83%) had tumors harboring FGF/FGFR aberrations. Three of nine patients in the 24-mg q.d. cohort experienced dose-limiting toxicities, including grade 3 increases in alanine transaminase, aspartate transaminase, and blood bilirubin (n = 1 each). The maximum tolerated dose (MTD) was determined to be 20 mg q.d.; no MTD was defined for the t.i.w. schedule. Across cohorts (n = 86), the most common treatment-emergent adverse events (TEAEs) were hyperphosphatemia (59%), diarrhea (37%), and constipation (34%); 48% experienced grade 3 TEAEs. TEAEs led to dose interruptions, dose reductions, and treatment discontinuations in 55%, 14%, and 3% of patients, respectively. Pharmacokinetics were dose proportional across all q.d. doses but not all t.i.w. doses evaluated, with saturation observed between 80 and 200 mg t.i.w. Serum phosphorus increased dose dependently with futibatinib on both schedules, but a stronger exposure-response relationship was observed with q.d. dosing, supporting 20 mg q.d. as the recommended phase II dose (RP2D). Overall, partial responses were observed in five patients [FGFR2 fusion-positive intrahepatic cholangiocarcinoma (n = 3) and FGFR1-mutant primary brain tumor (n = 2)], and stable disease in 41 (48%). CONCLUSIONS: Futibatinib treatment resulted in manageable safety, pharmacodynamic activity, and preliminary responses in patients with advanced solid tumors. The results of this phase I dose-escalation trial support 20 mg q.d. futibatinib as the RP2D. CLINICAL TRIAL REGISTRATION: FOENIX-101 (ClinicalTrials.gov, NCT02052778).
Subject(s)
Antineoplastic Agents , Neoplasms , Antineoplastic Agents/therapeutic use , Dose-Response Relationship, Drug , Humans , Maximum Tolerated Dose , Neoplasms/drug therapy , Protein Kinase Inhibitors/adverse effects , Receptor, Fibroblast Growth Factor, Type 1/therapeutic useABSTRACT
OBJECTIVE: An imbalance in oxidant-antioxidant status may impact the severity of sepsis. We hypothesised links between nitrosative stress and pro-inflammatory cytokines and their correlation with the severity of sepsis and associated organ dysfunction. METHODS: The hypothesis was tested in 110 patients with sepsis (in whom a disease severity score (APACHE II) and assessment of organ failure score (SOFA) were determined) and 55 healthy volunteers. Neutrophil inducible nitric oxide synthase (iNOS) expressions at mRNA and protein levels were estimated by real-time PCR and immuno-precipitation followed by Western blotting, respectively. Nitric oxide (NO) content was assessed in neutrophils by confocal microscopy, plasma nitrite by the Griess reaction and inflammatory cytokines (TNF-α, IFN-γ and IL-8) by ELISA (in plasma) and real-time PCR (in neutrophils). Serum bilirubin and creatinine were determined by routine methods and lung function by the PaO2/FiO2 ratio. RESULTS: Increased neutrophil iNOS expression and NO content, plasma total nitrite content and pro-inflammatory cytokines were present in sepsis patients (all P < 0.001). Plasma nitrite correlated with cytokines, APACHE II, SOFA, PaO2/FiO2 ratio, serum bilirubin and creatinine clearance (all r2 0.63-0.85, P < 0.001). Cytokines correlated with nitrite, APACHE II, SOFA, PaO2/FiO2 ratio, serum bilirubin and creatinine clearance (all r2 0.35-0.85, P < 0.001). CONCLUSION: Neutrophils iNOS expression, NO content, plasma nitrite and cytokines have a role in the assessment of the severity of sepsis and organ toxicity.
Subject(s)
Interferon-gamma/blood , Interleukin-8/blood , Multiple Organ Failure/diagnosis , Nitrosative Stress , Sepsis/diagnosis , Tumor Necrosis Factor-alpha/blood , APACHE , Adult , Aged , Bilirubin/blood , Biomarkers/blood , Case-Control Studies , Creatinine/blood , Female , Gene Expression , Humans , Male , Middle Aged , Multiple Organ Failure/blood , Multiple Organ Failure/physiopathology , Neutrophils/metabolism , Neutrophils/pathology , Nitric Oxide/blood , Nitric Oxide Synthase Type II/blood , Nitric Oxide Synthase Type II/genetics , Sepsis/blood , Sepsis/physiopathologyABSTRACT
BACKGROUND: Current data suggest that platinum-based combination therapy is the standard first-line treatment for biliary tract cancer. EGFR inhibition has proven beneficial across a number of gastrointestinal malignancies; and has shown specific advantages among KRAS wild-type genetic subtypes of colon cancer. We report the combination of panitumumab with gemcitabine (GEM) and oxaliplatin (OX) as first-line therapy for KRAS wild-type biliary tract cancer. METHODS: Patients with histologically confirmed, previously untreated, unresectable or metastatic KRAS wild-type biliary tract or gallbladder adenocarcinoma with ECOG performance status 0-2 were treated with panitumumab 6 mg kg(-1), GEM 1000 mg m(-2) (10 mg m(-2) min(-1)) and OX 85 mg m(-2) on days 1 and 15 of each 28-day cycle. The primary objective was to determine the objective response rate by RECIST criteria v.1.1. Secondary objectives were to evaluate toxicity, progression-free survival (PFS), and overall survival. RESULTS: Thirty-one patients received at least one cycle of treatment across three institutions, 28 had measurable disease. Response rate was 45% and disease control rate was 90%. Median PFS was 10.6 months (95% CI 5-24 months) and median overall survival 20.3 months (95% CI 9-25 months). The most common grade 3/4 adverse events were anaemia 26%, leukopenia 23%, fatigue 23%, neuropathy 16% and rash 10%. CONCLUSIONS: The combination of gemcitabine, oxaliplatin and panitumumab in KRAS wild type metastatic biliary tract cancer showed encouraging efficacy, additional efforts of genetic stratification and targeted therapy is warranted in biliary tract cancer.
Subject(s)
Adenocarcinoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biliary Tract Neoplasms/drug therapy , Gallbladder Neoplasms/drug therapy , Adenocarcinoma/mortality , Adenocarcinoma/secondary , Adult , Aged , Antibodies, Monoclonal/administration & dosage , Biliary Tract Neoplasms/mortality , Biliary Tract Neoplasms/pathology , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Disease-Free Survival , Female , Gallbladder Neoplasms/mortality , Gallbladder Neoplasms/pathology , Humans , Kaplan-Meier Estimate , Lymphatic Metastasis , Male , Middle Aged , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Panitumumab , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins p21(ras) , Treatment Outcome , ras Proteins/genetics , GemcitabineSubject(s)
Developing Countries , Diffusion of Innovation , Evidence-Based Practice/methods , Health Services Research/organization & administration , Public Health , Telemedicine/organization & administration , Clinical Competence , Efficiency, Organizational , Electronic Health Records , Evidence-Based Practice/organization & administration , Global Health , Health Knowledge, Attitudes, Practice , Health Services Research/methods , Humans , Public Sector , Telemedicine/instrumentationSubject(s)
Antibodies, Antineutrophil Cytoplasmic/blood , Lupus Erythematosus, Systemic/diagnosis , Myeloblastin/blood , Peroxidase/blood , Adult , Enzyme-Linked Immunosorbent Assay , Female , Fluorescent Antibody Technique, Indirect , Humans , Lupus Erythematosus, Systemic/blood , Lupus Erythematosus, Systemic/immunology , Myeloblastin/immunology , Peroxidase/immunology , Sensitivity and SpecificityABSTRACT
We have been developing an approach for automatically quantifying organ motion for adaptive radiation therapy of the prostate. Our approach is based on deformable image registration, which makes it possible to establish a correspondence between points in images taken on different days. This correspondence can be used to study organ motion and to accumulate inter-fraction dose. In prostate images, however, the presence of bowel gas can cause significant correspondence errors. To account for this problem, we have developed a novel method that combines large deformation image registration with a bowel gas segmentation and deflation algorithm. In this paper, we describe our approach and present a study of its accuracy for adaptive radiation therapy of the prostate. All experiments are carried out on 3-dimensional CT images.
Subject(s)
Imaging, Three-Dimensional/methods , Pattern Recognition, Automated/methods , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/radiotherapy , Radiographic Image Interpretation, Computer-Assisted/methods , Radiotherapy, Computer-Assisted/methods , Tomography, X-Ray Computed/methods , Algorithms , Artificial Intelligence , Cluster Analysis , Humans , Male , Radiographic Image Enhancement/methods , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
We have reported a simple method of determination of plasma oxalate using a Cl(-) and NO(3)(-) insensitive oxalate oxidase purified from grain sorghum leaf and commercially available peroxidase from horseradish [Pundir et al., Ind. J. Biochem. Biophys., 35 (1998) 120-122]. The present report describes the immobilization of both the enzymes onto alkylamine glass, their kinetic properties and application for discrete analysis of plasma oxalate. In the analytic method, H(2)O(2) generated from plasma oxalate by immobilized oxalate oxidase is measured colorimetrically at 520 nm by oxidative coupling with 4-aminophenazone, and phenol catalyzed by immobilized peroxidase. The minimum detection limit of the method is 2.5 micromol/l. Analytic recovery of added oxalate in plasma was 89. 5+/-4.1% (mean+/-S.D.). The within and between day CV for plasma oxalate measurement were <9.37 and <11.0%, respectively. The normal range of plasma oxalate as measured by the present method was 3.6 to 5.7 micromol/l. The method is not only free from interference by plasma Cl(-) and NO(3)(-) but also provides the reuse of glass beads and thus reduces the cost of analysis for routine.
Subject(s)
Biochemistry/methods , Horseradish Peroxidase/chemistry , Oxalates/blood , Oxidoreductases/chemistry , Poaceae/enzymology , Adolescent , Adult , Child , Female , Glass/chemistry , Horseradish Peroxidase/metabolism , Humans , Hydrogen-Ion Concentration , Kinetics , Male , Middle Aged , Models, Chemical , Oxidoreductases/analysis , Oxidoreductases/isolation & purification , Reproducibility of Results , TemperatureABSTRACT
PURPOSE: We reviewed our experience with patients who have undergone stereotactic radiosurgery (SRS) for brain metastases secondary to renal cell carcinoma (RCC). Analysis was performed to determine the survival, local control, distant brain failure (DBF), and then to define which tumors may not require upfront whole-brain radiotherapy (WBRT). METHODS AND MATERIALS: Twenty-nine patients with 66 tumors underwent SRS from 1991 to 1998. Median follow-up from time of brain metastases diagnoses relative to each tumor was 12.5 months and 6.8 months from the time of SRS. Median SRS dose was 1,800 cGy to the 60% isodose line. Three patients had undergone SRS for previously treated tumors. RESULTS: Median survival time from diagnosis was 10.0 months. Overall survival was not affected by age, addition of WBRT, number of lesions, tumor volume, or the presence of systemic disease. Of the 23 patients with follow-up neuroimaging, 4 of 47 (9%) tumors recurred. The addition of WBRT did not improve local control. Of the 13 patients who presented with a single lesion, 3 went on to develop DBF (23%), while 6 of the 10 patients who presented with multiple metastases developed DBF (60%). CONCLUSION: Patients with brain metastases secondary to RCC treated by SRS alone have excellent local control. The decision of whether or not to add WBRT to SRS should depend on whether the patient has a high likelihood of developing DBF. Our study suggests that patients who present with multiple brain lesions may be more likely to benefit from the addition of WBRT because they appear to be more than twice as likely to develop DBF as compared to patients with a single lesion.
Subject(s)
Brain Neoplasms/radiotherapy , Brain Neoplasms/surgery , Carcinoma, Renal Cell/radiotherapy , Carcinoma, Renal Cell/surgery , Cranial Irradiation/methods , Kidney Neoplasms/pathology , Radiosurgery , Adult , Aged , Analysis of Variance , Brain/pathology , Brain/radiation effects , Brain Neoplasms/secondary , Carcinoma, Renal Cell/secondary , Combined Modality Therapy , Female , Follow-Up Studies , Humans , Male , Middle Aged , Necrosis , Radiotherapy Dosage , Survival Analysis , Time FactorsABSTRACT
PURPOSE: To evaluate local control and overall survival after primary surgery for patients with atypical meningiomas. METHODS AND MATERIALS: From the Department of Pathology database, we identified 491 cases of meningioma treated at the Cleveland Clinic Foundation from 1979 through 1995. Thirty-three were diagnosed with atypical meningioma. Eleven of the excluded patients had incomplete records, were lost to follow-up, or received treatment elsewhere. Of the 22 evaluable patients, 15 underwent gross total resection (GTR), 4 had a subtotal resection (STR), and 3 had a resection of unknown extent. Eight patients received radiation therapy (2 after initial resection and 6 after at least one recurrence). The median radiation dose was 5,400 cGy (range 3,500-5,940). The median age at presentation was 55.5 years, the male:female ratio was 14:8, and 19/22 patients had a Karnofsky performance score (KPS) > or =80. The independent variables analyzed for overall survival and local control were gender, KPS (> or =80 vs. < 80), extent of surgery (GTR vs. STR or unknown extent of surgery), and postoperative radiation therapy. RESULTS: Median survival was 10.6 years, with a median follow-up of 5.5 years (range 1.5-14.8). Eight of the 22 patients had local recurrence, including 2/15 with GTR, 3/4 with STR, and all 3 patients who underwent resection of unknown extent. At 10 years, patients with GTR had a higher local control rate than those who had either a STR or a resection of unknown extent (87% vs. 17%; p = 0.02). The 5- and 10-year overall survival rates for the entire group were 91% and 76%, respectively. Patients who had GTR had 5- and 10-year overall survival of 87% and 87%, respectively. Patients with STR or resection of unknown extent had 5- and 10-year overall survival rates of 100% and 75%, respectively. CONCLUSION: In patients with atypical meningiomas, gross total resection is associated with a lower recurrence rate than in subtotal resection.
Subject(s)
Meningeal Neoplasms/mortality , Meningeal Neoplasms/surgery , Meningioma/mortality , Meningioma/surgery , Analysis of Variance , Dose-Response Relationship, Radiation , Female , Follow-Up Studies , Humans , Male , Meningeal Neoplasms/radiotherapy , Meningioma/radiotherapy , Middle Aged , Neoplasm Recurrence, Local/radiotherapy , Radiotherapy, Adjuvant , Retrospective Studies , Sex Factors , Survival Analysis , Treatment OutcomeABSTRACT
Induction of apoptosis in Drosophila requires the activity of three closely linked genes, reaper, hid and grim. Here we show that the proteins encoded by reaper, hid and grim activate cell death by inhibiting the anti-apoptotic activity of the Drosophila IAP1 (diap1) protein. In a genetic modifier screen, both loss-of-function and gain-of-function alleles in the endogenous diap1 gene were obtained, and the mutant proteins were functionally and biochemically characterized. Gain-of-function mutations in diap1 strongly suppressed reaper-, hid- and grim-induced apoptosis. Sequence analysis of these alleles revealed that they were caused by single amino acid changes in the baculovirus IAP repeat domains of diap1, a domain implicated in binding REAPER, HID and GRIM. Significantly, the corresponding mutant DIAP1 proteins displayed greatly reduced binding of REAPER, HID and GRIM, indicating that REAPER, HID and GRIM kill by forming a complex with DIAP1. These data provide strong in vivo evidence for a previously published model of cell death regulation in Drosophila.
Subject(s)
Apoptosis/genetics , Apoptosis/physiology , Drosophila Proteins , Drosophila/cytology , Drosophila/genetics , Genes, Insect , Insect Proteins/antagonists & inhibitors , Insect Proteins/physiology , Alleles , Animals , Drosophila/metabolism , Eye/anatomy & histology , Inhibitor of Apoptosis Proteins , Insect Proteins/genetics , Microscopy, Electron, Scanning , Models, Biological , Mutation , Neuropeptides/genetics , Peptides/genetics , PhenotypeABSTRACT
The adenovirus E1B 19,000-molecular-weight (19K) protein is a potent inhibitor of apoptosis and cooperates with E1A to transform primary rodent cells. E1B 19K shows sequence and functional homology to the mammalian antiapoptotic gene product, Bcl-2. Like Bcl-2, the biochemical mechanism of E1B 19K function includes binding to and antagonization of cellular proapoptotic proteins such as Bax, Bak, and Nbk/Bik. In addition, there is evidence that E1B 19K can affect gene expression, but whether this contributes to its antiapoptotic function has not been determined. In an effort to further understand the functions of E1B 19K, we screened for 19K-associated proteins by the yeast two-hybrid system. A novel protein, Btf (Bcl-2-associated transcription factor), that interacts with E1B 19K as well as with the antiapoptotic family members Bcl-2 and Bcl-xL but not with the proapoptotic protein Bax was identified. btf is a widely expressed gene that encodes a protein with homology to the basic zipper (bZip) and Myb DNA binding domains. Btf binds DNA in vitro and represses transcription in reporter assays. E1B 19K, Bcl-2, and Bcl-xL sequester Btf in the cytoplasm and block its transcriptional repression activity. Expression of Btf also inhibited transformation by E1A with either E1B 19K or mutant p53, suggesting a role in either promotion of apoptosis or cell cycle arrest. Indeed, the sustained overexpression of Btf in HeLa cells induced apoptosis, which was inhibited by E1B 19K. Furthermore, the chromosomal localization of btf (6q22-23) maps to a region that is deleted in some cancers, consistent with a role for Btf in tumor suppression. Thus, btf may represent a novel tumor suppressor gene residing in a unique pathway by which the Bcl-2 family can regulate apoptosis.
Subject(s)
Apoptosis , Proto-Oncogene Proteins c-bcl-2/physiology , RNA-Binding Proteins , Repressor Proteins/chemistry , Repressor Proteins/physiology , Transcription Factors/chemistry , Transcription Factors/physiology , Tumor Suppressor Proteins , Adenovirus E1A Proteins/metabolism , Amino Acid Sequence , Animals , Blotting, Northern , Cell Cycle , Cell Line , Cell Nucleus/metabolism , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Fluorescent Antibody Technique, Indirect , Genes, Reporter , HeLa Cells , Histidine/pharmacology , Humans , Kidney/metabolism , Models, Genetic , Molecular Sequence Data , Nerve Tissue Proteins/chemistry , Nerve Tissue Proteins/metabolism , Plasmids , Rats , Saccharomyces cerevisiae , Tissue Distribution , Transformation, GeneticABSTRACT
An oxalate oxidase (EC 1.2.3.4) purified from grain sorghum leaves was immobilized onto alkylamine and arylamine glass beads through glutaraldehyde coupling and diazotization with a conjugation yield of 10.8 mg/g support and 9.2 mg/g support, respectively. The enzyme retained 67.5% and 34.1% of its initial specific activity after immobilization onto alkylamine and arylamine glass, respectively. The enzyme exhibited an increase in optimum pH, temperature for maximum activity, energy of activation (Ea) and time for linearity but decrease in thermal stability at 60 degrees C after immobilization on both types of beads. The K(m) value for oxalate was increased by 9- to 10-fold but Vmax remained unaltered after immobilization. Both alkyl and arylamine glass bound enzyme was unaffected by physiological concentrations of Cl- and NO3-. The analytic importance of this work is demonstrated.
Subject(s)
Fabaceae/chemistry , Oxidoreductases/isolation & purification , Plants, Medicinal , Adult , Amines , Anions , Chelating Agents , Chlorides , Edetic Acid , Enzyme Stability , Enzymes, Immobilized , Glass , Heating , Humans , Hydrogen-Ion Concentration , Metals , Microspheres , Nitrates , Oxalates/urine , Oxidoreductases/chemistry , Plant Leaves/chemistry , ZirconiumABSTRACT
A membrane bound oxalate oxidase from leaves of Amaranthus spionsus has been partially purified and immobilized on alkylamine glass with a yield of 9.2 mg protein/g support. The enzyme retained 99.4% of initial activity of free enzyme after immobilization. There was no change in the optimum pH (3.5) and Vmax but the temperature for maximum activity was slightly decreased (35 degrees C) and energy of activation (Ea) and Km for oxalate were increased after immobilization. The immobilized enzyme preparation was stable for 6 months, when stored in distilled water at 4 degrees C. Presence of Cl- did not affect the activity of immobilized enzyme.
Subject(s)
Amines/chemistry , Enzymes, Immobilized/metabolism , Oxidoreductases/metabolism , Plant Leaves/enzymology , Adult , Enzymes, Immobilized/chemistry , Humans , Male , Oxidoreductases/chemistryABSTRACT
Quantitative chemical analysis of 225 urinary calculi (128 Renal, 57 bladder and 40 ureter) collected from hospitals of different districts of Haryana was carried out. CaOxM was found to be present as a major component in all the stones analysed, while MAP, HA, CA and UA were found in 83.7%, 83.6%, 13% and 78.9% cases, respectively. The content of CaOxM was found to be higher in renal stones as compared to ureter and bladder stones, while the concentration of MAP was higher in bladder stones as compared to kidney and ureter stones. HA content was higher in ureter and UA was higher in bladder stones as compared to other urinary stones.