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1.
Ann Oncol ; 29(6): 1423-1430, 2018 06 01.
Article in English | MEDLINE | ID: mdl-29648580

ABSTRACT

Background: The addition of bevacizumab to temozolomide-based chemoradiotherapy (TMZ/RT â†’ TMZ) did not prolong overall survival (OS) in patients with newly diagnosed glioblastoma in phase III trials. Elderly and frail patients are underrepresented in clinical trials, but early reports suggested preferential benefit in this population. Patients and methods: ARTE was a 2 : 1 randomized, multi-center, open-label, non-comparative phase II trial of hypofractionated RT (40 Gy in 15 fractions) with bevacizumab (10 mg/kg×14 days) (arm A, N = 50) or without bevacizumab (arm B, N = 25) in patients with newly diagnosed glioblastoma aged ≥65 years. The primary objective was to obtain evidence for prolongation of median OS by the addition of bevacizumab to RT. Response was assessed by RANO criteria. Quality of life (QoL) was monitored by the EORTC QLQ-C30/BN20 modules. Exploratory studies included molecular subtyping by 450k whole methylome and gene expression analyses. Results: Median PFS was longer in arm A than in arm B (7.6 and 4.8 months, P = 0.003), but OS was similar (12.1 and 12.2 months, P = 0.77). Clinical deterioration was delayed and more patients came off steroids in arm A. Prolonged PFS in arm A was confined to tumors with the receptor tyrosine kinase (RTK) I methylation subtype (HR 0.25, P = 0.014) and proneural gene expression (HR 0.29, P = 0.025). In a Cox model of OS controlling for established prognostic factors, associations with more favorable outcome were identified for age <70 years (HR 0.52, P = 0.018) and Karnofsky performance score 90%-100% (HR 0.51, P = 0.026). Including molecular subtypes into that model identified an association of the RTK II gene methylation subtype with inferior OS (HR 1.73, P = 0.076). Conclusion: Efficacy outcomes and exploratory analyses of ARTE do not support the hypothesis that the addition of bevacizumab to RT generally prolongs survival in elderly glioblastoma patients. Molecular biomarkers may identify patients with preferential benefit from bevacizumab. Clinical trial registration number: NCT01443676.


Subject(s)
Antineoplastic Agents, Immunological/therapeutic use , Bevacizumab/therapeutic use , Chemoradiotherapy/mortality , Glioblastoma/drug therapy , Glioblastoma/radiotherapy , Quality of Life , Radiation Dose Hypofractionation , Aged , Aged, 80 and over , Female , Follow-Up Studies , Glioblastoma/pathology , Humans , Male , Prognosis , Survival Rate
2.
J Appl Microbiol ; 117(5): 1328-35, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25066481

ABSTRACT

AIMS: In recent years, beer-spoilage cases from strictly anaerobic bacteria have risen in frequency, in connection with the production of non-pasteurized, non-alcohol and low-alcoholic beers and with the lowering of dissolved oxygen in the packaged beer. Selenomonas lacticifex, found in brewer's yeast and in biofilms covering some surfaces in brewery bottling area, is considered to be a beer-spoilage organism. This study aims to develop S. lacticifex-specific PCR assay. The objective of this study was also evaluation of the specificity and reproducibility of the developed PCR assay in real brewery samples. METHODS AND RESULTS: Three primers (one forward and two reverse) were designed for identification of the strictly anaerobic bacterium S. lacticifex on the basis of the species-specific sequences of the 16S rDNA region. The specificity of the primers was tested against 44 brewery-related non-target micro-organisms that could potentially occur in the same brewery specimens. None of the primer pairs amplified DNA from any of the non-S. lacticifex strains tested including genera from the same family (Pectinatus, Megasphaera, Zymophilus) and the closely related species Selenomonas ruminantium, showing thus 100% specificity. CONCLUSIONS: The PCR assay developed in this study enables the detection of the strictly anaerobic bacterium S. lacticifex in real brewery samples including pitching yeast. SIGNIFICANCE AND IMPACT OF THE STUDY: Selenomonas lacticifex-specific PCR assay developed in this study allows for the extension of the spectra of detected beer-spoilage micro-organisms in brewing laboratories and thus lowering the risk of contamination of the final product.


Subject(s)
Beer/microbiology , Polymerase Chain Reaction/methods , Selenomonas/isolation & purification , Biofilms , DNA Primers , RNA, Ribosomal, 16S/genetics , Selenomonas/physiology , Species Specificity
3.
Br J Neurosurg ; 27(4): 430-5, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23418781

ABSTRACT

BACKGROUND: The benefit of the introduction of alkylating chemotherapy in the treatment of glioblastoma multiforme (GBM) patients has been demonstrated by comparing radiotherapy with concomitant plus intermittent temozolomide (iTMZ) to radiation therapy. The isolated impact of the concomitant part of this protocol on survival was not investigated. We were therefore interested in the impact of the effect of the concomitant therapy part on survival. Hence, we compared patients treated with open surgery followed by radiotherapy and iTMZ with patients treated with concomitant plus iTMZ chemotherapy regarding overall (OS) and progression-free survival (PFS). METHODS: We performed a retrospective database search for the period between 2002 and 2007 and aimed at the identification of patients with primary GBM treated by open resection, radiotherapy (only radiotherapy = Group A and plus concomitant TMZ = Group B) and at least two cycles of TMZ. Patients were stratified for established prognostic markers like extent of resection, MGMT promoter methylation, Karnofsky Performance Scale (KPS), and age. RESULTS: Eighty-five patients were analysed, among which 42 patients (49%) were affiliated with Cohort A and 43 patients (51%) with Cohort B. Between both cohorts there was no significant difference regarding MGMT methylation status (p = 0.929), extend of resection (p = 0.102), KPS (p = 0.197) and age (p = 0.327). For the entire patient population, median OS was 18.6 months and PFS was 5.6 months. The extent of resection was significantly correlated with survival (OS: 21.5 vs. 16.1 months (p = 0.001) and PFS: 11.0 vs. 3.9 months (p = 0.044)). MGMT methylation status revealed a significant impact on OS (p = 0.008). Affiliation to Cohort A or B was neither correlated with PFS (p = 0.168) nor with OS (p = 0.343). CONCLUSION: Our study demonstrates that PFS and OS are strongly determined by the MGMT status and the extent of resection. Interestingly, concomitant radiochemotherapy was not superior to radiotherapy followed by iTMZ chemotherapy regarding OS and PFS.


Subject(s)
Antineoplastic Agents, Alkylating/pharmacology , Brain Neoplasms/therapy , Combined Modality Therapy/methods , DNA Modification Methylases/metabolism , DNA Repair Enzymes/metabolism , Dacarbazine/analogs & derivatives , Glioblastoma/therapy , Tumor Suppressor Proteins/metabolism , Antineoplastic Agents, Alkylating/administration & dosage , Antineoplastic Protocols , Biomarkers, Tumor , Brain Neoplasms/mortality , Brain Neoplasms/pathology , Chemoradiotherapy , Combined Modality Therapy/standards , DNA Methylation , Dacarbazine/administration & dosage , Dacarbazine/pharmacology , Female , Glioblastoma/mortality , Glioblastoma/pathology , Humans , Male , Middle Aged , Neurosurgical Procedures , Promoter Regions, Genetic , Retrospective Studies , Temozolomide , Treatment Outcome
4.
Br J Neurosurg ; 27(6): 772-8, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23662801

ABSTRACT

The prognostic role of O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation in glioblastoma patients treated with carmustine (BCNU) wafer implantation is unclear. Here, we report on a retrospective study of 47 patients with either newly diagnosed (30 patients) or recurrent (17 patients) glioblastoma (WHO grade IV) treated with BCNU (bis-chloroethylnitrosourea) wafers. Thirteen of the newly diagnosed patients received local BCNU and irradiation only (first-line BCNU), while 17 patients additionally received concomitant and adjuvant temozolomide (TMZ) radiochemotherapy (first-line BCNU + TMZ). Of the 17 patients treated for recurrent glioblastoma (second-line BCNU), 16 had received radiotherapy with concomitant and adjuvant TMZ as an initial treatment. Median overall survival (OS) did not significantly differ between 19 patients with MGMT promoter methylated tumors when compared to 28 patients with unmethylated tumors (18.9 vs 15.0 months; p = 0.1054). In the first-line BCNU + TMZ group, MGMT promoter methylation was associated with longer OS (21.0 vs 11.1 months, p = 0.0127), while no significant survival differences were detected in the other two subgroups. Progression-free survival did not significantly differ between patients with and without MGMT promoter methylated tumors in the entire patient cohort or any of the three subgroups. The first-line BCNU + TMZ group showed no significant difference in OS when compared to the first-line BCNU group (18.9 vs 14.7 months), but tended to have more therapy-related adverse effects (53% vs 24%, p = 0.105). In summary, MGMT promoter methylation showed a non-significant trend toward longer survival in our patient cohort. The combination of TMZ radiochemotherapy with local delivery of BCNU did not provide a significant survival benefit compared to local BCNU alone, but was associated with a higher rate of adverse effects. Owing to the small number of patients investigated, however, these findings would need to be corroborated in larger patient cohorts.


Subject(s)
Antineoplastic Agents, Alkylating/therapeutic use , Brain Neoplasms/drug therapy , Brain Neoplasms/genetics , Carmustine/therapeutic use , Glioblastoma/drug therapy , Glioblastoma/genetics , O(6)-Methylguanine-DNA Methyltransferase/genetics , Adult , Aged , Antineoplastic Agents, Alkylating/administration & dosage , Antineoplastic Agents, Alkylating/adverse effects , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carmustine/administration & dosage , Carmustine/adverse effects , Chemoradiotherapy/methods , Combined Modality Therapy , DNA Methylation , Dacarbazine/administration & dosage , Dacarbazine/analogs & derivatives , Disease-Free Survival , Female , Humans , Karnofsky Performance Status , Male , Middle Aged , Prognosis , Promoter Regions, Genetic/genetics , Retrospective Studies , Survival Analysis , Temozolomide
5.
Oncogene ; 26(34): 5010-6, 2007 Jul 26.
Article in English | MEDLINE | ID: mdl-17311001

ABSTRACT

Deletions of chromosomal arms 1p and 19q are frequent in oligodendroglial tumours and have been associated with sensitivity to radio- and chemotherapy as well as favourable prognosis. By using microarray-based expression profiling, we found that oligodendroglial tumours with 1p and 19q losses showed significantly lower expression of the CBP/p300-interacting transactivator with glutamic acid/aspartic acid-rich carboxyl-terminal domain 4 gene (CITED4) at 1p34.2 as compared to tumours without 1p and 19q losses. Mutational analysis showed no CITED4 mutations in gliomas. However, 1p and 19q losses as well as low expression of CITED4 transcripts were significantly associated with hypermethylation of the CITED4-associated CpG island. In line with the latter finding, treatment of CITED4 hypermethylated glioma cell lines with 5-aza-2'-deoxycytidine and trichostatine A resulted in a marked increase of the CITED4 transcript levels. Furthermore, CITED4 hypermethylation was significantly associated with longer recurrence-free and overall survival of patients with oligodendroglial tumours. Taken together, our results indicate that CITED4 is epigenetically silenced in the vast majority of oligodendroglial tumours with 1p and 19q deletions and suggest CITED4 hypermethylation as a novel prognostic marker in oligodendroglioma patients.


Subject(s)
Brain Neoplasms/genetics , Chromosomes, Human, Pair 19 , Chromosomes, Human, Pair 1 , Loss of Heterozygosity , Oligodendroglioma/genetics , Transcription Factors/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Brain Neoplasms/mortality , Child , CpG Islands , DNA Methylation , Down-Regulation , Female , Gene Silencing , Humans , Male , Middle Aged , Oligodendroglioma/mortality , Polymorphism, Genetic , Survival Analysis , Transcription Factors/biosynthesis , Transcription, Genetic
6.
Oncogene ; 26(38): 5662-8, 2007 Aug 16.
Article in English | MEDLINE | ID: mdl-17334394

ABSTRACT

In a genome-wide screen using differential methylation hybridization (DMH), we have identified a CpG island within the 5' region and untranslated first exon of the secretory granule neuroendocrine protein 1 gene (SGNE1/7B2) that showed hypermethylation in medulloblastomas compared to fetal cerebellum. Bisulfite sequencing and combined bisulfite restriction assay were performed to confirm the methylation status of this CpG island in primary medulloblastomas and medulloblastoma cell lines. Hypermethylation was detected in 16/23 (70%) biopsies and 7/8 (87%) medulloblastoma cell lines, but not in non-neoplastic fetal (n=8) cerebellum. Expression of SGNE1 was investigated by semi-quantitative competitive reverse transcription-polymerase chain reaction and found to be significantly downregulated or absent in all, but one primary medulloblastomas and all cell lines compared to fetal cerebellum. After treatment of medulloblastoma cell lines with 5-aza-2'-deoxycytidine, transcription of SGNE1 was restored. No mutation was found in the coding region of SGNE1 by single-strand conformation polymorphism analysis. Reintroduction of SGNE1 into the medulloblastoma cell line D283Med led to a significant growth suppression and reduced colony formation. In summary, we have identified SGNE1 as a novel epigenetically silenced gene in medulloblastomas. Its frequent inactivation, as well as its inhibitory effect on tumor cell proliferation and focus formation strongly argues for a significant role in medulloblastoma development.


Subject(s)
Cerebellar Neoplasms/pathology , DNA Methylation , Medulloblastoma/pathology , Neuroendocrine Secretory Protein 7B2/genetics , Azacitidine/analogs & derivatives , Azacitidine/pharmacology , Base Sequence , Cell Line, Tumor , Cell Proliferation , Cerebellar Neoplasms/genetics , CpG Islands/genetics , DNA Modification Methylases/antagonists & inhibitors , Decitabine , Down-Regulation/drug effects , Down-Regulation/genetics , Enzyme Inhibitors/pharmacology , Gene Expression Profiling , Gene Expression Regulation, Neoplastic/drug effects , Humans , Medulloblastoma/genetics , Molecular Sequence Data , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Transcription, Genetic/drug effects
7.
Clin Exp Immunol ; 153(3): 351-9, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18637103

ABSTRACT

Refractory coeliac disease (RCD) is a very rare and dangerous form of CD, in which gluten-free diet loses its therapeutic effect and the damage of intestinal mucosa persists. Because of the adherence to the diet, serological markers of CD [immunoglobulin A (IgA) antibodies against gliadin, tissue transglutaminase (tTG) and endomysium] are often missing in RCD patients. We found substantially elevated levels of IgA anti-calreticulin (CRT) antibodies in the sera of almost all RCD patients tested. These sera were negative for IgA antibodies to gliadin and tTG and only some of them showed IgA antibodies to enterocytes. Analysis of patients' IgA reactivity to CRT fragments (quarters and halves) by Western blotting revealed differences in the specificity of IgA antibodies between RCD and CD patients. We therefore used the Pepscan technique with synthetic overlapping decapeptides of CRT to characterize antigenic epitopes recognized by serum IgA antibodies of RCD patients. Employing this method we demonstrated several dominant antigenic epitopes recognized by IgA antibodies of RCD patients on the CRT molecule. Epitope GVTKAAEKQMKD was recognized predominantly by serum IgA of RCD patients. Our results suggest that testing for serum IgA antibodies against CRT and its selected peptide could be a very useful tool in RCD differential diagnosis.


Subject(s)
Antibodies, Anti-Idiotypic/immunology , Calreticulin/immunology , Celiac Disease/immunology , Immunoglobulin A/immunology , Aged , Antibodies, Anti-Idiotypic/blood , Blotting, Western , Calreticulin/blood , Celiac Disease/blood , Celiac Disease/diagnosis , Diet, Gluten-Free/adverse effects , Enterocytes/chemistry , Enterocytes/immunology , Enzyme-Linked Immunosorbent Assay , Female , Gliadin/blood , Gliadin/immunology , Humans , Immunoglobulin A/blood , Male , Middle Aged , Sensitivity and Specificity , Transglutaminases/blood , Transglutaminases/immunology
8.
Folia Microbiol (Praha) ; 52(5): 463-70, 2007.
Article in English | MEDLINE | ID: mdl-18298042

ABSTRACT

tmRNA and protein SmpB are the main components required for rescue of stalled ribosomes incapable of properly elongating or terminating the polypeptide chain. We examined the tmRNA level and protein synthesis in Streptomyces aureofaciens, S. griseus and S. collinus synthesizing tetracycline, streptomycin and kirromycin, respectively, during various stress conditions. Downshift in temperature caused a decrease in protein synthesis but the level of tmRNA increased. Shift up in temperature induced decay of tmRNA in all strains and in S. collinus led to stimulation and in S. aureofaciens and S. griseus to inhibition of protein synthesis. At high NaCl concentrations protein synthesis was inhibited and tmRNA decayed. Shift in pH from 7.0 to 5.0 had no pronounced effect on the tmRNA level while upshift to pH 9.0 in S. collinus and S. aureofaciens caused inhibition of protein synthesis and decay of tmRNA in S. collinus. In contrast, protein synthesis and tmRNA level increased in S. griseus at the alkaline pH. Our data show that tmRNA abundance is important for survival of streptomycetes under certain unfavorable conditions.


Subject(s)
RNA, Bacterial/metabolism , Streptomyces aureofaciens/physiology , Streptomyces/physiology , Blotting, Northern , Hydrogen-Ion Concentration , Protein Biosynthesis , RNA, Messenger/metabolism , RNA, Transfer/metabolism , Sodium Chloride/adverse effects , Temperature
9.
Clin Neuropathol ; 25(2): 95-7, 2006.
Article in English | MEDLINE | ID: mdl-16550743

ABSTRACT

Numerous studies have shown that cavernous malformations may be localized in almost every region of the brain as well as in the spinal cord. Spinal cord cavernous malformations (SCCM) have been diagnosed more frequently since magnetic resonance imaging (MRI) has become more widely available. Most are asymptomatic but may present as a diagnostic challenge with diffuse symptoms ranging from mere sensory deficits to paraparesis possibly affecting both upper and lower motor neuron. A 29-year-old Arabian man was admitted to the hospital with a progressive sensory loss to light touch, pin prick and vibration of the right and in a lesser extent of the left leg without any association to a particular dermatome. He additionally presented with progressing paresthesias in both legs, unsteady gait and incipient bladder- and bowl incontinence starting approximately 1 week prior to admission. Spinal MRI showed a central, slightly lateralized intramedullary lesion 1 cm in diameter located within the conus medullaris that was suspicious for an intramedullary cavernous malformation. The lesion was accompanied by a perifocal edema and showed an inhomogeneous hypointense core on T2WI consistent with an acute cavernous hemorrhage. Treatment of symptomatic intramedullary cavernous angiomas should, if possible, consist of total surgical excision. It is essential to achieve complete removal during the first operation to avoid any residues that may lead to further bleeding.


Subject(s)
Hemangioma, Cavernous/pathology , Hemorrhage/pathology , Sensation Disorders/etiology , Spinal Cord Neoplasms/pathology , Adult , Hemangioma, Cavernous/surgery , Hemorrhage/etiology , Humans , Magnetic Resonance Imaging , Male , Neurosurgical Procedures , Recovery of Function , Spinal Cord Neoplasms/surgery
10.
Folia Microbiol (Praha) ; 51(6): 517-24, 2006.
Article in English | MEDLINE | ID: mdl-17455787

ABSTRACT

Transition from exponential phase of growth to stationary phase in Streptomyces aureofaciens is characterized by a decrease in the rate of translation and induction of tetracycline (Ttc) biosynthesis. In exponential phase, no significant changes were found in the activity of ribosomes at binding of ternary complex Phe-tRNA.EF-Tu.GTP to the A-site on ribosomes. Overexpression of Ttc in stationary phase is accompanied by a decrease in the binding of the ternary complex Phe-tRNA.EF-Tu.GTP to the A-site of ribosome and a formation of an aggregate with Ttc by part of the ribosomes. Antibiotics that cause ribosome to stall or pause could increase the requirement for tmRNA in the process called trans-translation. We found differences in the level of tmRNA during the development of S. aureofaciens. Subinhibitory concentrations of Ttc, streptomycin and chloramphenicol induced an increase in the tmRNA level in cells from the exponential phase of growth. In vitro trans-translation system of S. aureofaciens was sensitive to Ttc at a concentration of > 15 micromol/L; the trans-translation system can thus be considered to contribute to resistance against Ttc produced only at sublethal concentrations. These experiments suggest that the main role of the rising tmRNA level at the beginning of the Ttc production is connected with ribosome rescue.


Subject(s)
Bacterial Proteins/biosynthesis , RNA, Bacterial/metabolism , Streptomyces aureofaciens/metabolism , Tetracycline/biosynthesis , Anti-Bacterial Agents/pharmacology , Chloramphenicol/pharmacology , Guanosine Triphosphate/metabolism , Peptide Elongation Factor Tu/metabolism , Protein Biosynthesis , Protein Synthesis Inhibitors/pharmacology , RNA, Messenger/metabolism , RNA, Transfer, Phe/metabolism , Ribosomes/metabolism , Spectinomycin/pharmacology , Streptomyces aureofaciens/genetics , Streptomyces aureofaciens/growth & development , Tetracycline/pharmacology
11.
Gene ; 187(2): 281-7, 1997 Mar 18.
Article in English | MEDLINE | ID: mdl-9099893

ABSTRACT

A fragment (172 bp) of B. subtilis phage phi29 DNA, which does not contain a functional promoter for phage transcription, has been shown to direct transcription in the promoter-probe plasmid pPV33. The promoter candidate found in this fragment by the computer method of acceptability is compared with cryptic promoters selected by this computer method. It is characterized in vitro by electron microscopic visualization of RNA polymerase binding and 'run off' transcription, and in vivo by high resolution S1 mapping.


Subject(s)
Bacillus Phages/genetics , Computer Simulation , DNA, Viral , Promoter Regions, Genetic , Transcription, Genetic , Bacillus subtilis/virology , Base Sequence , Chromosome Mapping , Cloning, Molecular , DNA-Directed RNA Polymerases/metabolism , DNA-Directed RNA Polymerases/ultrastructure , Gene Expression , Molecular Sequence Data , Plasmids/ultrastructure , Single-Strand Specific DNA and RNA Endonucleases/metabolism , Tetracycline Resistance/genetics
12.
Cancer Gene Ther ; 8(11): 843-51, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11773974

ABSTRACT

Somatic gene therapy with the herpes simplex virus type I thymidine kinase gene/ganciclovir (HSV-Tk/GCV) system and murine retroviral vector producer cells (VPCs) was introduced as a new adjuvant treatment modality to treat tumor bulk and to prevent tumor recurrence in patients harboring malignant glioma. The single-center experience after treatment of 27 patients undergoing tumor resection followed by intracerebral VPC injection for HSV-Tk suicide gene therapy will be presented focused on findings of systematic and close MRI follow-up and a few histological specimens. The data indicate that hemorrhagic necrosis due to endothelial cell transfection mediated vessel necrosis and that local inflammatory immune response occurs frequently after gene therapy. These phenomena seem to be specific because none of the patients of a control group showed any similar features. The prognosis (time to progression, survival) of the patients with "bystander effects" after gene therapy was better, but compared to those patients without bystander effects, they were also privileged by a favorable constellation of prognostic factors. Therefore, the appearance of these neuroradiologic features cannot serve as an indicator for treatment effectiveness and outcome.


Subject(s)
Brain Neoplasms/therapy , Brain/blood supply , Bystander Effect , Encephalitis/etiology , Ganciclovir/therapeutic use , Genetic Therapy/adverse effects , Glioma/therapy , Herpesvirus 1, Human/enzymology , Thymidine Kinase/genetics , Transfection/methods , Adolescent , Adult , Aged , Aged, 80 and over , Brain/pathology , Brain Neoplasms/diagnosis , Encephalitis/diagnosis , Encephalitis/immunology , Female , Genetic Vectors , Glioma/diagnosis , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neovascularization, Pathologic/diagnosis , Retroviridae/genetics
13.
FEMS Microbiol Lett ; 187(1): 9-14, 2000 Jun 01.
Article in English | MEDLINE | ID: mdl-10828392

ABSTRACT

We demonstrated two different DNA-dependent RNA polymerase (RNAP) alpha subunits in spores of Streptomyces granaticolor with apparent molecular masses of 40 and 43 kDa. The 43-kDa subunit was also found in vegetative cells. These two proteins are highly similar to each other as well as to other bacterial RNAP alpha subunits. The 40-kDa subunit is shortened from its C-terminus, in the portion of the protein, required for binding of DNA and transcription regulators. The gene for RNAP alpha from S. granaticolor was cloned and sequenced and the corresponding protein was overproduced in Escherichia coli. In vitro experiments using purified RNAP alpha showed that the cell free extract from spores of S. granaticolor exhibits proteolytic activity responsible for the alpha subunit shortening, whereas that from vegetative cells does not. This modification of alpha subunit might point to a novel mechanism of transcriptional control in streptomycetes.


Subject(s)
Bacterial Proteins/isolation & purification , DNA-Directed RNA Polymerases/isolation & purification , Streptomyces/enzymology , Amino Acid Sequence , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Cloning, Molecular , DNA-Directed RNA Polymerases/genetics , DNA-Directed RNA Polymerases/metabolism , Electrophoresis, Polyacrylamide Gel , Genes, Bacterial , Mass Spectrometry , Molecular Sequence Data , Molecular Weight , Peptide Mapping , Polymerase Chain Reaction , Recombinant Proteins/isolation & purification , Sequence Alignment , Spores, Bacterial/enzymology , Transcription, Genetic
14.
J Neurosurg ; 91(6): 1041-4, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10584854

ABSTRACT

The authors report the case of a man who had suffered a penetrating metal splinter injury to the left frontal lobe at 18 years of age. Thirty-seven years later the patient developed a left-sided frontal tumor at the precise site of the meningocerebral scar and posttraumatic defect. Histological examination confirmed a glioblastoma multiforme adjacent to the dural scar and metal splinters. In addition, a chronic abscess from which Propionibacterium acnes was isolated was found within the glioma tissue. The temporal and local association of metal splinter injury with chronic abscess, scar formation, and malignant glioma is highly suggestive of a causal relationship between trauma and the development of a malignant brain tumor.


Subject(s)
Brain Neoplasms/pathology , Foreign Bodies/pathology , Frontal Lobe/injuries , Glioblastoma/pathology , Head Injuries, Penetrating/pathology , Metals , Adolescent , Adult , Brain Abscess/pathology , Brain Abscess/surgery , Brain Neoplasms/surgery , Cell Transformation, Neoplastic/pathology , Cicatrix/pathology , Cicatrix/surgery , Follow-Up Studies , Foreign Bodies/surgery , Frontal Lobe/pathology , Glioblastoma/surgery , Head Injuries, Penetrating/surgery , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/surgery , Propionibacterium acnes , Reoperation
15.
J Neurosurg ; 93(2): 335-41, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10930023

ABSTRACT

The authors report on an 11-year-old boy in whom proptosis of the eye caused by a benign intraosseous xanthofibroma of the left orbital wall became clinically apparent at the age of 4 years. Two years later he developed bilateral papilledema, at which time computerized tomography and magnetic resonance studies revealed multiple enhancing intracranial lesions. The largest mass was located in the left middle fossa; other lesions were located at the tentorium cerebelli, in both lateral ventricles, near the superior sagittal sinus, and extracranially near the left jugular vein. The mass in the left middle fossa was resected and diagnosed as juvenile xanthogranuloma (JXG). Thirty months later, the patient again became symptomatic, exhibiting behavioral abnormalities and a decrease in mental powers. At that time, the two remaining lesions in both lateral ventricles had grown enough to cause trapping of the temporal horns and raised intracranial pressure. These lesions were successively resected and histopathologically confirmed to be JXGs. However, resection of the second intraventricular lesion was complicated by postoperative bilateral amaurosis, presumably caused by postdecompression optic neuropathy. According to a review of the literature, fewer than 20 patients with JXG involving the central nervous system have been reported. The patient described in this report is the first in whom multiple intracranial JXGs developed in the absence of cutaneous manifestations. Although JXGs are biologically benign lesions, the treatment of patients with multifocal and/or progressive intracranial manifestations is problematic.


Subject(s)
Brain Diseases/pathology , Xanthogranuloma, Juvenile/pathology , Brain Diseases/surgery , Child , Disease Progression , Humans , Male , Optic Nerve Injuries , Postoperative Complications , Xanthogranuloma, Juvenile/surgery
16.
J Biomol Struct Dyn ; 4(3): 477-89, 1986 Dec.
Article in English | MEDLINE | ID: mdl-3271452

ABSTRACT

Circular dichroism spectroscopy, absorption spectroscopy, measurements of Tm values, sedimentation analysis and electron microscopy were used to study properties of calf thymus DNA in methanol-water mixtures as a function of monovalent cation (Na+ or Cs+) concentration and also in the presence of divalent cations Ca2+, Mg2+, and Mn2+. In the absence of divalent cations only slight conformational changes occurred and no condensation and/or aggregation could be detected. The Tm values depend on the amount of methanol and on the nature and concentration of cations. In methanol-water mixtures higher thermal stability was observed in solutions containing Cs+ ions. Up to 40% (v/v) methanol the addition of divalent ions leads to DNA stabilization. At methanol concentration higher than 50% the presence of divalent cations causes DNA condensation and denaturation even at room temperature. The denaturation is reversible with respect to EDTA addition indicating that no separation of complementary strands occurred and the resulting form of DNA is probably similar to the P form. DNA destacking appears to be a direct consequence of stronger cation binding by the condensed DNA in methanol-water mixtures.


Subject(s)
Cations , DNA , Methanol , Nucleic Acid Conformation , Water , Animals , Cations, Divalent , Cations, Monovalent , Cattle , Circular Dichroism , DNA/ultrastructure , Hot Temperature , Nucleic Acid Denaturation , Thymus Gland
17.
Folia Biol (Praha) ; 36(1): 12-22, 1990.
Article in English | MEDLINE | ID: mdl-2160894

ABSTRACT

Binding of the major avian retroviral nucleocapsid protein ASLV NC(p12) to the MAV-1 (myeloblastosis-associated virus) proviral dsDNA and viral ssRNA was analysed using electron microscopy. Specificity of the binding was estimated by special computer programs. The NC(p12) protein bound to MAV-1 proviral dsDNA (clone pAT153--MAV-1), but specificity of this binding was not found by computer evaluation. NC(p12) also bound to nondenatured 70S viral RNA at a rate of 25 +/- 3 molecules per RNA molecule. When this RNA was denatured either before or after the complexing, it showed no binding affinity for the protein. This result implies that preserved secondary structure of the viral RNA was required for the binding.


Subject(s)
Avian Leukosis Virus/genetics , Avian Myeloblastosis Virus/genetics , Capsid Proteins , Capsid/metabolism , DNA, Viral/metabolism , Proviruses/metabolism , RNA, Viral/metabolism , Retroviridae Proteins , Viral Core Proteins/metabolism , Animals , Avian Myeloblastosis Virus/metabolism , Binding Sites , Carrier Proteins/metabolism , Chickens , DNA/metabolism , DNA, Viral/ultrastructure , DNA-Binding Proteins/metabolism , Proviruses/genetics , RNA, Viral/ultrastructure , RNA-Binding Proteins
18.
Folia Biol (Praha) ; 36(1): 1-11, 1990.
Article in English | MEDLINE | ID: mdl-2160893

ABSTRACT

Using SP-Sephadex column chromatography we isolated from an avian retrovirus, AMV(MAV), nucleic acid-binding proteins ASLV NC(p12) and MA(p19). As shown by several criteria, namely SDS-PAGE, PR(p15) protease activity, and nucleic acid binding assay with the use of both ss and ds DNAs, our NC(p12) and MA(p19) isolates are virtually pure proteins mutually not cross-contaminated. Rabbit anti-NC(p12) and anti-MA(p19) sera which we prepared did not cross-react mutually. We conclude that both NC(p12) and MA(p19) and antibodies against them are adequately pure preparations for investigating their nucleic acid binding specificities towards AMV(MAV) genomic RNA and MAV-1 proviral DNA using electron microscopy supported by computer analysis of electron micrographs.


Subject(s)
Avian Leukosis Virus/genetics , Avian Myeloblastosis Virus/genetics , Capsid Proteins , Capsid/metabolism , Retroviridae Proteins/metabolism , Viral Core Proteins/metabolism , Viral Matrix Proteins/metabolism , Animals , Antibodies, Viral/immunology , Avian Myeloblastosis Virus/metabolism , Capsid/isolation & purification , Carrier Proteins/metabolism , Chickens , Chromatography, Gel , DNA, Viral/metabolism , DNA-Binding Proteins/metabolism , Electrophoresis, Polyacrylamide Gel , Immunoblotting , RNA, Viral/metabolism , RNA-Binding Proteins , Retroviridae Proteins/isolation & purification , Viral Core Proteins/isolation & purification , Viral Matrix Proteins/isolation & purification
19.
Folia Biol (Praha) ; 36(1): 23-31, 1990.
Article in English | MEDLINE | ID: mdl-2160895

ABSTRACT

The binding of the avian retroviral matrix protein ASLV MA(p19) to homologous viral ssRNA and proviral dsDNA was analysed using electron microscopic methods combined with a special computer evaluation. No binding affinity of MA(p19) to homologous nondenatured or denatured viral RNA was found. In contrast, ASLV MA(p19) was shown to have one specific binding site on MAV-1 proviral dsDNA at position 6795 +/- 345 bp from the 5' end of the molecule. A second specific binding site was found in a cellular sequence.


Subject(s)
Avian Leukosis Virus/genetics , Avian Myeloblastosis Virus/genetics , DNA, Viral/metabolism , Proviruses/metabolism , RNA, Viral/metabolism , Retroviridae Proteins/metabolism , Viral Matrix Proteins/metabolism , Animals , Binding Sites , Chickens , Cloning, Molecular , DNA, Viral/ultrastructure , DNA-Binding Proteins/metabolism , Proviruses/genetics , RNA, Viral/ultrastructure , Retroviridae Proteins/ultrastructure , Viral Matrix Proteins/ultrastructure
20.
Folia Microbiol (Praha) ; 36(2): 120-6, 1991.
Article in English | MEDLINE | ID: mdl-1823645

ABSTRACT

Partially purified DNA-dependent RNA polymerase of Streptomyces granaticolor was further separated on phosphocellulose in 50% glycerol and a single activity peak was obtained. The enzyme isolated in this way consisted of 4 main proteins with molar mass of 145, 132, 50 and 46 kg/mol. These four subunits represented 93% proteins of the active fraction. To test the ability of RNA polymerase to recognize specific sites on DNA, binding sites for RNA polymerase on phage phi 29 DNA were mapped by electron microscopy. The specific binding sites detected were compared with those for RNA polymerases from Escherichia coli and Bacillus subtilis.


Subject(s)
Bacteriophages/enzymology , DNA-Directed RNA Polymerases/metabolism , Streptomyces/enzymology , Binding Sites , DNA, Viral/metabolism , DNA-Directed RNA Polymerases/isolation & purification
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