Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 26
Filter
1.
J Imaging ; 9(7)2023 Jul 06.
Article in English | MEDLINE | ID: mdl-37504813

ABSTRACT

Raster logs are scanned representations of the analog data recorded in subsurface drilling. Geologists rely on these images to interpret well-log curves and deduce the physical properties of geological formations. Scanned images contain various artifacts, including hand-written texts, brightness variability, scan defects, etc. The manual effort involved in reading the data is substantial. To mitigate this, unsupervised computer vision techniques are employed to extract and interpret the curves digitally. Existing algorithms predominantly require manual intervention, resulting in slow processing times, and are erroneous. This research aims to address these challenges by proposing VeerNet, a deep neural network architecture designed to semantically segment the raster images from the background grid to classify and digitize (i.e., extracting the analytic formulation of the written curve) the well-log data. The proposed approach is based on a modified UNet-inspired architecture leveraging an attention-augmented read-process-write strategy to balance retaining key signals while dealing with the different input-output sizes. The reported results show that the proposed architecture efficiently classifies and digitizes the curves with an overall F1 score of 35% and Intersection over Union of 30%, achieving 97% recall and 0.11 Mean Absolute Error when compared with real data on binary segmentation of multiple curves. Finally, we analyzed VeerNet's ability in predicting Gamma-ray values, achieving a Pearson coefficient score of 0.62 when compared to measured data.

2.
J Surg Res ; 255: 411-419, 2020 11.
Article in English | MEDLINE | ID: mdl-32619855

ABSTRACT

BACKGROUND: Preoperative type and screen (TS) is routinely performed before elective thoracic surgery. We sought to evaluate the utility of this practice by examining our institutional data related to intraoperative and postoperative transfusions for two common, complex procedures. MATERIALS AND METHODS: A single-center, retrospective review of a prospective thoracic surgery database was performed. Patients who underwent consecutive elective anatomic lung resection (ALR) and esophagectomy from January 2015 to April 2018 were included. Perioperative characteristics between patients who received transfusion of packed red blood cells and those who did not were compared. The rates of emergent and nonemergent transfusions were evaluated. Cost data were derived from institutional charges and Centers for Medicare & Medicaid Services fee schedules. RESULTS: Of 370 patients, 16 (4.3%) received a transfusion and four (1.1%) were deemed emergent by the surgeons and 0 (0%) by blood bank criteria. For ALR (n = 321), 13 (4.0%) received a transfusion, and four (1.2%) were emergent. For esophagectomies (n = 49), three (6.1%) received a transfusion, and none were emergent. Patients who underwent ALR requiring a transfusion had a lower preoperative hemoglobin (11.7 versus 13.4 gm/dL, P = 0.001), higher estimated blood loss (1325 versus 196 mL, P < 0.001), and longer operative time (291 versus 217 min, P = 0.003) than nontransfused patients. Based on current volumes, eliminating TS in these patients would save at least an estimated $60,100 per year. CONCLUSIONS: Emergent transfusion in ALR and esophagectomy is rare. Routine preoperative TS is most likely unnecessary for these cases. These results will be used in a quality improvement initiative to change practice at our institution.


Subject(s)
Blood Transfusion/statistics & numerical data , Esophagectomy/statistics & numerical data , Preoperative Care , Pulmonary Surgical Procedures/statistics & numerical data , Unnecessary Procedures , Aged , Female , Humans , Male , Middle Aged , Retrospective Studies
3.
Trends Pharmacol Sci ; 40(5): 298-308, 2019 05.
Article in English | MEDLINE | ID: mdl-30948191

ABSTRACT

Defective regulation of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signalling pathway in cancers, haematological diseases, and chronic inflammatory conditions highlights its clinical significance. While several biologic and small molecule therapeutics targeting this pathway have been developed, these have several limitations. Therefore, there is a need to identify new targets for intervention. Suppressor of cytokine signalling (SOCS) proteins are a family of inducible inhibitors of cytokine receptors that activate the JAK-STAT pathway. Here we propose that newly identified mechanisms controlling SOCS function could be exploited to develop molecularly targeted drugs with unique modes of action to inhibit JAK-STAT signalling in disease.


Subject(s)
Janus Kinases/metabolism , STAT Transcription Factors/metabolism , Signal Transduction/drug effects , Suppressor of Cytokine Signaling Proteins/metabolism , Animals , Humans , Janus Kinases/antagonists & inhibitors , Molecular Targeted Therapy , STAT Transcription Factors/antagonists & inhibitors , Small Molecule Libraries/pharmacology , Suppressor of Cytokine Signaling Proteins/antagonists & inhibitors
4.
Crit Care Explor ; 1(8): e0032, 2019 Aug.
Article in English | MEDLINE | ID: mdl-32166273

ABSTRACT

To determine if a set of time-varying biological indicators can be used to: 1) predict the sepsis mortality risk over time and 2) generate mortality risk profiles. DESIGN: Prospective observational study. SETTING: Nine Canadian ICUs. SUBJECTS: Three-hundred fifty-six septic patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Clinical data and plasma levels of biomarkers were collected longitudinally. We used a complementary log-log model to account for the daily mortality risk of each patient until death in ICU/hospital, discharge, or 28 days after admission. The model, which is a versatile version of the Cox model for gaining longitudinal insights, created a composite indicator (the daily hazard of dying) from the "day 1" and "change" variables of six time-varying biological indicators (cell-free DNA, protein C, platelet count, creatinine, Glasgow Coma Scale score, and lactate) and a set of contextual variables (age, presence of chronic lung disease or previous brain injury, and duration of stay), achieving a high predictive power (conventional area under the curve, 0.90; 95% CI, 0.86-0.94). Including change variables avoided misleading inferences about the effects of day 1 variables, signifying the importance of the longitudinal approach. We then generated mortality risk profiles that highlight the relative contributions among the time-varying biological indicators to overall mortality risk. The tool was validated in 28 nonseptic patients from the same ICUs who became septic later and was subject to 10-fold cross-validation, achieving similarly high area under the curve. CONCLUSIONS: Using a novel version of the Cox model, we created a prognostic tool for septic patients that yields not only a predicted probability of dying but also a mortality risk profile that reveals how six time-varying biological indicators differentially and longitudinally account for the patient's overall daily mortality risk.

5.
3 Biotech ; 8(10): 410, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30237957

ABSTRACT

The present study reports engineered cold tolerance and toxicity analysis in genetically modified tomato (Solanum lycopersicum L. cv. Pusa Ruby) developed through constitutive over expression of Nicotiana tabacum Osmotin gene. Rate of seed germination, seedling establishment and growth remained unaffected in the transgenic tomato in response to a low temperature (15 °C) treatment, but were significantly (P ≤ 0.05) reduced in the wild type. At reproductive stage, the wild type plants failed to recover at the low temperature (4.0 °C) treatment for 10 days but the transgenic plants survived successfully without any leaf senescence or other visible chilling injury symptoms. The quantitative transcript expression analysis confirmed up regulation of the transgene by 55% in the transgenic plants on cold treatment for 2 h whereas, the transcripts were not detected in the wild type. Containment evaluation under normal environmental conditions revealed similar morphology in both the transgenic and wild type tomato plants however an average fruit yield was higher in the transgenic plants (725.91 ± 39.27 g) than the wild type (679.84 ± 28.80 g). The composition of mature fruits in terms of element content was at par in both the transgenic and wild type except significantly higher Ca and Mg contents in the transgenic fruits than that of the wild type. Further, acute and sub-acute toxicity tests conducted in the adult female Wister rats revealed no mortality or significant changes in general and psychological behaviour, at par food intake and body weight and, normal biochemical, and hematological parameters for animals fed with the wild type or transgenic tomato fruits as compared to the control group, confirming its safety for animal consumption.

6.
Hum Mol Genet ; 27(2): 373-384, 2018 01 15.
Article in English | MEDLINE | ID: mdl-29177465

ABSTRACT

Attempts have been made to treat nonsense-associated genetic disorders by chemical agents and hence an improved mechanistic insight into the decoding of readthrough signals is essential for the identification and characterisation of factors for the treatment of these disorders. To identify either novel compounds or genes that modulate translation readthrough, we have employed dual reporter-based high-throughput screens that use enzymatic and fluorescence activities and screened bioactive National Institute of Neurological Disease Syndrome (NINDS) compounds (n = 1000) and siRNA (n = 288) libraries. Whilst siRNAs targeting kinases such as CSNK1G3 and NME3 negatively regulate readthrough, neither the bioactive NINDS compounds nor PTC124 promote readthrough. Of note, PTC124 has previously been shown to promote readthrough. Furthermore, the impacts of G418 on the components of eukaryotic selenocysteine incorporation machinery have also been investigated. The selenocysteine machinery decodes the stop codon UGA specifying selenocysteine in natural selenoprotein genes. We have found that the eukaryotic SelC gene promotes the selenocysteine insertion sequence (SECIS)-mediated readthrough but inhibits the readthrough activity induced by G418. We have previously reported that SECIS-mediated readthrough at UGA codons follows a non-processive mechanism. Here, we show that G418-mediated promotion of readthrough also occurs through a non-processive mechanism which competes with translation termination. Based on our observations, we suggest that proteins generated through a non-processive mechanism may be therapeutically beneficial for the resolution of nonsense-associated genetic disorders.


Subject(s)
High-Throughput Nucleotide Sequencing/methods , Small Molecule Libraries/pharmacology , Aminoglycosides/metabolism , Base Sequence , Casein Kinase Ialpha/metabolism , Codon, Nonsense , Codon, Terminator , Humans , NM23 Nucleoside Diphosphate Kinases/metabolism , Nucleic Acid Conformation , Oxadiazoles/pharmacology , Peptide Chain Termination, Translational , Protein Biosynthesis , Protein Synthesis Inhibitors , RNA, Messenger/genetics , RNA, Small Interfering/genetics
7.
Cell Mol Biol (Noisy-le-grand) ; 63(8): 109-114, 2017 Aug 30.
Article in English | MEDLINE | ID: mdl-28886323

ABSTRACT

The present study was carried out to investigate the mutagenic and cytotoxic potential of n-hexane and aqueous-methanolic whole plant extracts of Alternanthera bettzickiana. Aqueous-methanolic and n-hexane extracts of Alternanthera bettzickiana extracts were assessed for the mutagenic potential with Salmonella tester strains TA-100 and TA-102 in the presence and absence of the rodent enzyme activation system and cytotoxic potential was assessed by MTT assay. Aqueous-methanolic extract showed the presence of saponins, tannins, terpenoids, flavonoids and glycosides. However n-hexane extract revealed the presence of tannins and terpenoids only. It was found that a concentration as low as 15mg/mL of both extracts was more mutagenic to the TA 102 tester strain than TA-100. Hexane whole plant extract of Altenanthera bettzickiana was more mutagenic than aqueous-methanolic extract considering revertant colonies of TA 100 strain. Aqueous-methanolic and n-hexane whole plant extracts of Altenanthera bettzickiana showed higher mutagenic potential in the presence of the enzyme activation system. Mutagenicity of aqueous-methanolic extract increased with an enzyme activation system in case of TA 100 whereas mutagenicity of n-hexane extract decreased in the presence of the enzyme activation system with TA 100 and TA 102 strains. Aqueous-methanolic and n-Hexane whole plant extracts of Alternanthera bettzickiana showed an IC-50 of 493 and 456 µg/mL in BHK-21 cells respectively. It can be concluded that Altenanthera bettzickiana exhibited mutagenic activity in a bacterial reverse mutation assay with and without enzyme activation systems. However, it showed limited cytotoxicity to BHK-21 cells.


Subject(s)
Amaranthaceae/chemistry , Cytotoxins/pharmacology , DNA, Bacterial/drug effects , Mutagens/pharmacology , Animals , Cell Line , Cell Survival/drug effects , Cricetulus , Cytotoxins/isolation & purification , DNA, Bacterial/genetics , Flavonoids/chemistry , Flavonoids/isolation & purification , Glycosides/chemistry , Glycosides/isolation & purification , Hexanes/chemistry , Methanol/chemistry , Mutagens/isolation & purification , Pakistan , Plant Extracts/chemistry , Plants, Medicinal , Salmonella/drug effects , Salmonella/genetics , Saponins/chemistry , Saponins/isolation & purification , Solvents/chemistry , Tannins/chemistry , Tannins/isolation & purification , Terpenes/chemistry , Terpenes/isolation & purification , Water/chemistry
8.
Front Plant Sci ; 7: 22, 2016.
Article in English | MEDLINE | ID: mdl-26858739

ABSTRACT

NAC genes contribute to enhance survivability of plants under conditions of environmental stress and in secondary growth of the plants, thereby building biomass. Thus, genetic transformation of plants using NAC genes provides a possibility to tailor biofuel plants. Over-expression studies have indicated that NAC family genes can provide tolerance to various biotic and abiotic stresses, either by physiological or biochemical changes at the cellular level, or by affecting visible morphological and anatomical changes, for example, by development of lateral roots in a number of plants. Over-expression of these genes also work as triggers for development of secondary cell walls. In our laboratory, we have observed a NAC gene from Lepidium latifolium contributing to both enhanced biomass as well as cold stress tolerance of model plants tobacco. Thus, we have reviewed all the developments of genetic engineering using NAC genes which could enhance the traits required for biofuel plants, either by enhancing the stress tolerance or by enhancing the biomass of the plants.

9.
Cancer Cell Int ; 14(1): 122, 2014.
Article in English | MEDLINE | ID: mdl-25469108

ABSTRACT

BACKGROUND: Tumour homing capacity of engineered human adipose-derived mesenchymal stromal cells (ADMSCs) expressing anti-tumour agents might be the key for a much safer and yet efficient targeted tumour therapy. However, ADMSCs exhibit resistant to most gene transfection techniques and the use of highly efficient viral vectors has several disadvantages primarily concerning safety risk. Here, we optimized the use of highly efficient and safe nucleofection-based transfection using plasmid encoded for TNF-Related Apoptosis Inducing Ligand (TRAIL) into ADMSCs and investigated the potential anti-tumourigenic of TRAIL-expressing ADMSCs (ADMSCs-TRAIL) on selected cancer models in vitro. METHODS: Different concentration of TRAIL-encoded plasmid and ADMSCs were nucleofected and the percentage of fluorescence cells were analyzed to determine the optimal condition. TRAIL protein and mRNA were validated in nucloeofected ADMSCs using ELISA and RT-PCR respectively. Evaluation of TRAIL specific death receptors were performed on both tumours (A549/lung tumour, LN18/glioblastoma and HepG2/hepatocellular carcinoma) and haematological malignant lines (REH/acute lymphocytic leukaemia, K562/chronic myelogenous leukaemia and KMS-28BM/multiple myeloma) using flow cytometry. ADMSCs-TRAIL was subsequently assessed for anti-tumourigenic properties using both proliferation assay (MTS assay) and apoptosis assay (Annexin-V / Propidium Iodide staining). RESULTS: Nucleofection showed increased total plasmid concentration (2 µg to 8 µg) resulted in significantly higher reporter expression (11.33% to 39.7%) with slight reduction on cells viability (~10%). ADMSCs-TRAIL significantly inhibited ~50% of cell proliferation in LN18, signifying sensitivity of the cell to ADMSCs-TRAIL mediated inhibition. Inhibition of both tumour and malignant lines proliferation by ADMSCs-TRAIL conditioned medium noticed in HepG2, A549 and REH respectively, whereas K562 and KMS-28BM malignant lines exhibit resistant to ADMSCs-TRAIL mediated inhibition. Moreover, we found that native ADMSCs alone were capable of inducing apoptosis in both LN18 and HepG2 tumour lines, despite substantial increased on the percentage of apoptosis by ADMSCs-TRAIL. CONCLUSION: ADMSCs-TRAIL selectively inhibit cancer model and markedly induces apoptosis. Through investigation of the specific TRAIL death receptors expression, we saw that the receptors expression did influence the sensitivity of some but not all cancer lines to TRAIL-mediated inhibition. This study provides further insight into the anti-tumourigenic potential of ADMSCs-TRAIL on different cancer models.

10.
Mol Biol Rep ; 41(11): 7479-89, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25106524

ABSTRACT

We report elevated biomass and altered growth characteristics of tobacco plants up on transformation with a NAC (NAM, ATAF1/2,CUC2) gene (GenBank Accession FJ754254) isolated from Lepidium latifolium L. (LlaNAC). Transgenic plants showed significant differences in fresh weight, midrib length of longest leaf, leaf area, height of the plant, root and shoot weights, etc. during vegetative phase. On 100th day after sowing (DAS), plants of transgenic lines were 2-3 times taller than the wild type plants, though no significant difference was recorded in moisture contents of any of the plant tissues. Over-expression of NAC gene up to 2,000 fold was recorded in leaves of transgenic plants on 100th DAS. Interestingly, transgenic plants showed significantly shortened (P(t) = 0.02-0.04) life cycle, as they showed a completely altered growth behaviour. Transgenic plants entered reproductive phase earlier by 60 days, with lines NC2 and NC7b entering first, followed by line NC10. However, the time period spent in the reproductive phase by the plant was nearly twice in case of transgenic lines NC2, NC7b and NC10, as compared to the wild type plants. Despite that, these lines completed their life cycle in 45-60 days lesser than the time taken by wild-type tobacco plants. No difference was recorded in fruit and seed yield of transgenic or wild type plants. To the best of our knowledge, this is the first report on over-expression of NAC gene causing altered growth and biomass patterns. We expect this study to become an important reference towards future engineering of plants for fuel and fodder purposes.


Subject(s)
Biofuels , Gene Expression Regulation, Plant/physiology , Genetic Engineering/methods , Lepidium/genetics , Nicotiana/growth & development , Plant Proteins/genetics , Transformation, Genetic/genetics , Acclimatization/genetics , Biomass , Cold Temperature , Gene Expression Regulation, Plant/genetics , Lepidium/metabolism , Life Cycle Stages/genetics , Nicotiana/genetics
11.
Colloids Surf B Biointerfaces ; 102: 63-9, 2013 Feb 01.
Article in English | MEDLINE | ID: mdl-23006553

ABSTRACT

A new type of fluorescent carbon based nanomaterial has drawn considerable attention due to their unique physicochemical properties. Carboxyl functionalized carbon nanoparticles are well documented in the literature. However, the carbonyl moiety in the carboxyl group considerably reduces the photoluminescence quantum yield. In this study, we present a direct, simple and novel synthetic route to produce hydroxyl functionalized fluorescent carbon nanoparticles derived from candle soot using organic base and surfactant which could be readily scaled up. The functionalization of carbon nanoparticle was confirmed by various spectroscopic techniques. (1)H NMR and FTIR measurements have been used to confirm the presence of sp(2) carbon in the form of aryl and hydroxyl moieties. MALDI-TOF Mass and TGA measurements further confirmed the functionalization. Structural characterization of these particles by Raman spectroscopy showed characteristic peaks located at 1333 and 1583 cm(-1) corresponding to diamond-like (D) and graphite-like (G) bands of the carbon allotropes respectively. The minimum grain size of 7.3 nm was calculated using Raman spectra of the functionalized carbon nanoparticles which corroborate well with the results of dynamic light scattering (DLS) and TEM studies. UV-vis spectroscopic measurements displayed an absorption band at ca. 245 nm, which was consistent with the optical characteristics of functionalized carbon nanoparticles. PL measurements confirmed that the functionalized carbon nanoparticles have characteristic emission peak and shows fluorescence under blue light excitation. With a combination of free dispersion in water and attractive PL properties, these functionalized carbon nanoparticles hold promise for application in nanotechnology.


Subject(s)
Carbon/chemistry , Nanoparticles/chemistry , Microscopy, Electron, Transmission , Nanotechnology , Spectrum Analysis, Raman , Surface Properties
12.
Hum Mol Genet ; 17(11): 1683-94, 2008 Jun 01.
Article in English | MEDLINE | ID: mdl-18321866

ABSTRACT

Heterozygous germline defects in a gene encoding a type II receptor for bone morphogenetic proteins (BMPR-II) underlie the majority of inherited cases of the vascular disorder known as pulmonary arterial hypertension (PAH). However, the precise molecular consequences of PAH causing mutations on the function of the receptor complex remain unclear. We employed novel enzymatic and fluorescence activity based techniques to assess the impact of PAH mutations on pre-mRNA splicing, nonsense-mediated decay (NMD) and receptor complex interactions. We demonstrate that nonsense and frameshift mutations trigger NMD, providing further evidence that haplo-insufficiency is a major molecular consequence of disease-related BMPR2 mutations. We identified heterogeneous functional defects in BMPR-II activity, including impaired type I receptor phosphorylation, receptor interactions and altered receptor complex stoichiometry leading to perturbation of downstream signalling pathways. Importantly, these studies demonstrate that the intracellular domain of BMPR-II is both necessary and sufficient for receptor complex interaction. Finally and to address the potential for resolution of stoichiometric balance, we investigated an agent that promotes translational readthrough of a BMPR2 nonsense reporter construct without interfering with the NMD pathway. We propose that stoichiometric imbalance, due to either haplo-insufficiency or loss of optimal receptor-receptor interactions impairs BMPR-II mediated signalling in PAH. Taken together, these studies have identified an important target for early therapeutic intervention in familial PAH.


Subject(s)
Bone Morphogenetic Protein Receptors, Type II/genetics , Bone Morphogenetic Protein Receptors, Type II/metabolism , Codon, Nonsense , Hypertension, Pulmonary/enzymology , Hypertension, Pulmonary/genetics , RNA Stability , Aminoglycosides/pharmacology , Bone Morphogenetic Protein Receptors, Type I/metabolism , Exons , Genes, Reporter , Humans , Introns , Phosphorylation , Protein Biosynthesis/genetics , RNA Precursors/metabolism , RNA Splicing/genetics , RNA, Messenger/metabolism , Signal Transduction , Transcription, Genetic/drug effects
13.
Nucleic Acids Res ; 33(7): e66, 2005 Apr 11.
Article in English | MEDLINE | ID: mdl-15824058

ABSTRACT

Methods for determining protein-protein interactions in mammalian cells typically rely on single reporter functions and are susceptible to variations between samples particularly in regard to levels of transcription, processing and translation. A method has been developed for determining protein-protein interactions in mammalian cells, which bypasses these variables confounding single reporter assays. The approach utilizes two units of gene expression linked to reporter functions that are interposed by a deactivation-activation unit in such a way that the downstream expression unit is switched off. Hence upstream expression occurs regardless of protein-protein interaction, leading to the production of the upstream reporter. In the event of protein-protein interactions, the downstream expression unit is switched on leading to dual reporter read outs. Thus, the ratio of the two reporter activities provides a measure to determine the efficiency of protein-protein interactions. To access the system we screened a mutant of BMPR2 where the interaction between BMPR-II and LIMK is abrogated. BMPR-II is a type II receptor of the TGFbeta superfamily and plays a key role in the pathogenesis of familial pulmonary arterial hypertension. This system has potential for high-throughput screening of libraries (peptide, chemical, cDNA, etc.) to isolate agents that are capable of interfering with highly selective protein-protein interaction.


Subject(s)
Genes, Reporter , Protein Interaction Mapping/methods , Bone Morphogenetic Protein Receptors, Type II , Cell Line , Fluorescent Dyes , Humans , Luciferases/analysis , Luciferases/genetics , Microscopy, Fluorescence , Protein Serine-Threonine Kinases/genetics , Recombinant Fusion Proteins/analysis , beta-Galactosidase/analysis , beta-Galactosidase/genetics
14.
Mol Microbiol ; 53(2): 405-17, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15228523

ABSTRACT

The leading region of the conjugal bacterial plasmid ColIb-P9 contains three dispersed repeats of a 328 bp sequence homologous to Frpo, a sequence from plasmid F that acts as a promoter in single-stranded DNA. One of these sequences, ssi3, inactive in the double-stranded form, promoted in vitro transcription exclusively from the single strand that is transferred during conjugation. Promoter activity was dependent on the presence of RNA polymerase holoenzyme containing sigma 70. Transcription initiated from the position predicted from folding the single-stranded DNA to form a pseudo double-stranded hairpin structure containing recognizable -35 and -10 promoter elements. Footprinting of RNA polymerase holoenzyme on single-stranded ssi3 DNA was consistent with this suggestion. Mutagenesis of the putative -35 region inactivated the promoter, but random mutations in the -10 region had little effect. The putative -10 region is a poor match to the consensus sequence and contains mismatched bases. Elimination of these mismatches invariably destroyed single-strand promoter activity. These observations reveal the crucial contribution of the unpaired bases in the -10 region in potentiating the formation of the productive open complex with RNA polymerase.


Subject(s)
Bacteriocin Plasmids/genetics , DNA, Single-Stranded/physiology , Nucleic Acid Conformation , Promoter Regions, Genetic , Repetitive Sequences, Nucleic Acid , Transcription, Genetic , Base Pair Mismatch , Conjugation, Genetic , Consensus Sequence , DNA Footprinting , DNA, Bacterial/genetics , DNA, Bacterial/physiology , DNA, Single-Stranded/genetics , DNA-Directed RNA Polymerases/metabolism , F Factor/genetics , Gene Expression Regulation, Bacterial , Mutation , Sequence Homology , Sigma Factor/metabolism
15.
Hum Mol Genet ; 12(11): 1337-48, 2003 Jun 01.
Article in English | MEDLINE | ID: mdl-12761049

ABSTRACT

The hnRNP G family comprises three closely related proteins, hnRNP G, RBMY and hnRNP G-T. We showed previously that they interact with splicing activator proteins, particularly hTra2beta, and suggested that they were involved in regulating Tra2-dependent splicing. We show here that hnRNP G and hTra2beta have opposite effects upon the incorporation of several exons, both being able to act as either an activator or a repressor. HnRNP G acts via a specific sequence to repress the skeletal muscle-specific exon (SK) of human slow skeletal alpha-tropomyosin, TPM3, and stimulates inclusion of the alternative non-muscle exon. The binding of hnRNP G to the exon is antagonized by hTra2beta. The two proteins also have opposite effects upon a dystrophin pseudo-exon. This exon is incorporated in a patient to a higher level in heart muscle than skeletal muscle, causing X-linked dilated cardiomyopathy. It is included to a higher level after transfection of a mini-gene into rodent cardiac myoblasts than into skeletal muscle myoblasts. Co-transfection with hnRNP G represses incorporation in cardiac myoblasts, whereas hTra2beta increases it in skeletal myoblasts. Both the cell specificity and the protein responses depend upon exon sequences. Since the ratio of hnRNP G to Tra2beta mRNA in humans is higher in skeletal muscle than in heart muscle, we propose that the hnRNP G/Tra2beta ratio contributes to the cellular splicing preferences and that the higher proportion of hnRNP G in skeletal muscle plays a role in preventing the incorporation of the pseudo-exon and thus in preventing skeletal muscle dystrophy.


Subject(s)
Drosophila Proteins , Heterogeneous-Nuclear Ribonucleoproteins/metabolism , RNA Splicing , RNA/metabolism , Ribonucleoproteins/metabolism , Base Sequence , Cardiomyopathy, Dilated/genetics , Cells, Cultured , Dystrophin/genetics , Dystrophin/metabolism , Exons , Heterogeneous-Nuclear Ribonucleoproteins/genetics , Humans , Molecular Sequence Data , Muscle, Skeletal/cytology , Muscle, Skeletal/physiology , Myoblasts, Cardiac/physiology , Organ Specificity , Pseudogenes , Ribonucleoproteins/genetics , Tropomyosin/genetics , Tropomyosin/metabolism
16.
Acta Cytol ; 45(4): 605-9, 2001.
Article in English | MEDLINE | ID: mdl-11480726

ABSTRACT

BACKGROUND: Mucinous cystadenocarcinoma of the salivary gland is a rare entity. Review of the literature from 1991 to 1999 revealed no previous reports on its cytologic features. CASE: A 25-year-old man had a slowly growing, painless mass in the left parotid gland. Fine needle aspiration biopsy, performed prior to surgical excision, showed clusters of minimally atypical epithelial cells in which occasional vacuolated cells containing mucin could be seen. Pathologic evaluation of the resected parotid mass showed it to be a mucinous cystadenocarcinoma. CONCLUSION: The cytologic differential diagnosis of mucinous cystadenocarcinoma is with low grade mucoepidermoid carcinoma and with mucinous adenocarcinoma. Mucinous cystadenocarcinoma must be cystic; cysts may be present in low grade mucoepidermoid carcinoma, but their size and prominence varies. Mucinous adenocarcinoma is not cystic but gelatinous. Nuclei are bland in both mucinous cystadenocarcinoma and low grade mucoepidermoid carcinoma but are atypical in mucinous adenocarcinoma. There is no squamous differentiation in either mucinous cystadenocarcinoma or mucinous adenocarcinoma, but it is subtle in low grade mucoepidermoid carcinomas. Mucinous cystadenocarcinoma should be considered a potential candidate in the differential diagnosis of mucinous lesions that can occur in the salivary gland.


Subject(s)
Cystadenocarcinoma, Mucinous/pathology , Parotid Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Biopsy, Needle , Cystadenocarcinoma, Mucinous/diagnosis , Female , Humans , Male , Parotid Neoplasms/diagnosis
17.
J Biol Chem ; 275(20): 14846-52, 2000 May 19.
Article in English | MEDLINE | ID: mdl-10809727

ABSTRACT

The synthesis of eukaryotic selenoproteins involves the recoding of an internal UGA codon as a site for selenocysteine incorporation. This recoding event is directed by a selenocysteine insertion sequence in the 3'-untranslated region. Because UGA also functions as a signal for peptidyl-tRNA hydrolysis, we have investigated how the rates of translational termination and selenocysteine incorporation relate to cis-acting elements in the mRNA as well as to trans-acting factors in the cytoplasm. We used cis-elements from the phospholipid glutathione peroxidase gene as the basis for this work because of its relatively high efficiency of selenocysteine incorporation. The last two codons preceding the UGA were found to exert a far greater influence on selenocysteine incorporation than nucleotides downstream of it. The efficiency of selenocysteine incorporation was generally much less than 100% but could be partially enhanced by concomitant overexpression of the tRNA(Sec) gene. The combination of two or three UGA codons in one reading frame led to a dramatic reduction in the yield of full-length protein. It is therefore unlikely that multiple incorporations of selenocysteine are processive with respect to the mode of action of the ribosomal complex binding to the UGA site. These observations are discussed in terms of the mechanism of selenoprotein synthesis and its ability to compete with termination at UGA codons.


Subject(s)
Peptide Chain Termination, Translational , Proteins/genetics , RNA, Transfer, Amino Acid-Specific/genetics , Selenocysteine/metabolism , 3' Untranslated Regions/genetics , Amino Acid Sequence , Animals , Base Sequence , Binding Sites , Codon/genetics , Cysteine/metabolism , Humans , Mice , Molecular Sequence Data , Mutagenesis, Insertional , Oligodeoxyribonucleotides/chemistry , Plasmids , Protein Biosynthesis , Proteins/chemistry , Selenoproteins , Sequence Alignment , Sequence Homology, Amino Acid , Xenopus
18.
Br J Cancer ; 71(2): 357-62, 1995 Feb.
Article in English | MEDLINE | ID: mdl-7841053

ABSTRACT

The measurement of tumour cell proliferation is becoming increasingly recognised in defining prognostic groups. Proliferating cell nuclear antigen (PCNA) immunolocalisation can be used as an index of cell proliferation and may define the extent of departure from normal growth control. The monoclonal antibody PC10 stains PCNA in archival paraffin-embedded tissue. This study investigates its potential as a prognostic marker in early and advanced ovarian cancer. A three-stage immunoperoxidase technique was developed to detect the monoclonal antibody PC10. Archival paraffin-embedded tissue from 19 stage I ovarian tumours (13 malignant and six borderline) and 79 advanced (stage IIb-IV) ovarian tumours (patients entered into the Third North-West Thames Ovarian Cancer Trial) was immunostained with PC10. PC10 immunostaining was performed successfully in 91.8% of cases. The PC10 labelling index (PC10 LI) ranged from 1.5% to 88% with a mean value of 47.4%. Stage I borderline tumours had significantly lower PCNA labelling indexes than stage I malignant tumours (P < 0.048). In advanced disease there was an inverse correlation between PC10 and overall survival, and in those patients who underwent good debulking surgery (37 patients with disease < 2 cm diameter) a low PC10 value (< 36.5%) correlated with improved survival (log-rank trend test for survival, chi 2 = 5.75, P = 0.017). PCNA immunostaining defines a good prognostic subgroup in adequately debulked patients with ovarian cancer.


Subject(s)
Antigens, Neoplasm/analysis , Biomarkers, Tumor/analysis , Immunoenzyme Techniques , Ovarian Neoplasms/chemistry , Ovarian Neoplasms/mortality , Proliferating Cell Nuclear Antigen/analysis , Adult , Aged , Antibodies, Monoclonal/immunology , Antigens, Neoplasm/immunology , Carboplatin/therapeutic use , Cell Division , Combined Modality Therapy , England/epidemiology , Female , Humans , Laparotomy , Life Tables , Middle Aged , Neoplasm Staging , Neoplasm, Residual , Ovarian Neoplasms/pathology , Ovarian Neoplasms/therapy , Paraffin Embedding , Prognosis , Proliferating Cell Nuclear Antigen/immunology , Radiotherapy, Adjuvant , Survival Analysis
19.
Int J Cancer ; 56(4): 603-8, 1994 Feb 15.
Article in English | MEDLINE | ID: mdl-8112898

ABSTRACT

Transforming growth factor alpha (TGF-alpha) has multifunctional biological effects on a variety of mesenchymal and epithelial cells. It is a potent mitogen for a number of normal and transformed cell types, regulates extracellular matrix (ECM) production and promotes breast, kidney and lung morphogenesis. To clarify the role of ECM proteins in the morphogenetic and mitogenic effects of TGF-alpha, we have used a human colon carcinoma cell line (SW1222) which expresses EGF receptor. Here we show that TGF-alpha at 1 ng/ml increases the proliferation of SW1222 cells, but only when they are cultured on plastic rather than collagen-coated plates. Higher concentrations of TGF-alpha (10 ng/ml) did not increase cell proliferation but significantly enhanced the crypt-like glandular differentiation when cells were grown in 3-dimensional collagen gel (p = 0.027). These effects were accompanied by increased expression of alpha 2 beta 1 and alpha 3 beta 1 integrin molecules, which are receptors for extracellular matrix proteins, and by a statistically significant increase in binding of SW1222 cells to type-1 collagen. The effects of TGF-alpha both on binding to type-1 collagen and on morphological differentiation in 3-dimensional collagen gel were inhibited by monoclonal antibodies recognizing the alpha 2 beta 1 integrin. These data indicate that the morphogenetic or mitogenic activities of TGF-alpha are critically dependent on cellular interactions with extracellular matrix proteins and are primarily mediated by the alpha 2 beta 1 integrin receptor. Inappropriate expression of this growth factor, seen in tumours whose cell-matrix interactions are greatly impaired, could have deleterious effects on the maintenance of normal tissue architecture and growth control.


Subject(s)
Colonic Neoplasms/pathology , Extracellular Matrix Proteins/physiology , Mitogens/pharmacology , Transforming Growth Factor alpha/pharmacology , Antibodies, Monoclonal/pharmacology , Cadherins/metabolism , Cell Differentiation , Cell Division , Collagen/metabolism , Humans , Integrin alpha3beta1 , Integrins/immunology , Integrins/metabolism , Integrins/physiology , Morphogenesis , Tumor Cells, Cultured
20.
Cell Prolif ; 26(5): 449-60, 1993 Sep.
Article in English | MEDLINE | ID: mdl-9087535

ABSTRACT

The immunohistochemical expression of transforming growth factor-alpha (TGF alpha) has been examined in a range of normal adult epithelial tissues from both man and rat using an anti-hTGF alpha monoclonal antibody (GF10). No differences in distribution were apparent between man and rat. In the continually renewing epithelium of the gastrointestinal tract, no staining was seen within the proliferative compartments, but strong immunoexpression was noted in various differentiated populations. In the testis, the spermatogonia were unstained, but the more luminally orientated germ cells were strongly positive. In the gastrointestinal tract, at least, any mitogenic action of TGF alpha must be mediated through a relatively long paracrine loop. In contrast, the differentiated parenchyma of kidney, salivary gland and liver remained unstained apart from collecting ducts in the kidney, striated ducts in salivary glands and bile ducts in the liver. The association of TGF alpha with tubule formation was reinforced by the very strong staining of newly forming bile ducts in a model of liver oval cell proliferation. Thus, in all the epithelia studied there was a distinct spatial pattern of TGF alpha immunoreactivity.


Subject(s)
Transforming Growth Factor alpha/metabolism , Adult , Animals , Antibodies, Monoclonal , Colon/metabolism , Epithelium/metabolism , Gastric Mucosa/metabolism , Humans , Immunohistochemistry , Intestine, Small/metabolism , Kidney/metabolism , Liver/metabolism , Male , Parotid Gland/metabolism , Rats , Rats, Inbred F344 , Rats, Sprague-Dawley , Testis/metabolism , Tissue Distribution , Transforming Growth Factor alpha/immunology
SELECTION OF CITATIONS
SEARCH DETAIL
...