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1.
Eur Rev Med Pharmacol Sci ; 28(5): 1733-1740, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38497855

ABSTRACT

OBJECTIVE: Dental healthcare personnel face the potential danger of being exposed to infectious patients while administering local anesthesia injections during dental operations. This could lead to unintentional transfer of infectious diseases from patients to physicians. Although safety measures such as the One-hand-scoop technique and the use of safety syringes, plastic needle cap holders, and needles with safety caps are in place, there have been instances of needle stick injuries reported in clinics. This might be due to the lack of adherence to conventional safety measures or the impracticality of safety techniques and safety syringes. This article aims to demonstrate the utilization of dental tweezers, specifically London College tweezers or dental forceps, for the secure recapping of needles, eliminating the requirement for extra equipment or devices. SUBJECTS AND METHODS: After obtaining ethical approval (Approval No.: 024-01-2024) from the College of Dentistry, Dar Al Uloom University, 67 dental professionals, with consent for participation in the study, were included. They were requested to use dental tweezers/London College tweezers and dental extraction forceps such as maxillary anterior, mandibular anterior, and maxillary bayonet root forceps individually to recap the local anesthetic needles. The efficacy of these techniques was evaluated against the one-hand scoop technique for its ease, convenience, and reliability in preventing needle stick injuries. RESULTS: The evaluation of dental professionals regarding the ease of using dental tweezers to recap needles, compared to the one-hand scoop technique (p=0.592), maxillary bayonet root forceps (p=0.746), mandibular anterior forceps (p=0.380), and maxillary anterior forceps (p=0.808), did not yield statistically significant results. The assessment of the procedural simplicity of the one-hand scoop technique showed a satisfaction rate of over 40%, whereas the application of dental tweezers resulted in a satisfaction rate of 30%. However, the use of dental tweezers for needle recapping resulted in a satisfaction rate of over 50%, compared to a satisfaction rate of 30% for the one-handed scoop technique. CONCLUSIONS: There is no statistically significant difference in the assessment of the efficacy of dental tweezers and the one-hand scoop technique, bayonet root forceps, mandibular anterior forceps, maxillary anterior forceps, and dental tweezers for the needle capping technique. Therefore, dental forceps can be used instead of the one-handed scoop approach. The needle recapping procedure outlined in our study, aimed at preventing needle stick injuries, is simple to implement, and all dental specialties have convenient access to the required instruments.


Subject(s)
Needlestick Injuries , Humans , Needlestick Injuries/prevention & control , Reproducibility of Results , Anesthesia, Local , Anesthetics, Local , Dentists
2.
Eur Rev Med Pharmacol Sci ; 27(19): 9043-9049, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37843317

ABSTRACT

OBJECTIVE: There is an abundance of information on facelifts, blepharoplasties, rhinoplasty, and other cosmetic surgical procedures for the upper third of the face, but little is known about perioral lip rejuvenation. The aim of this article is to examine the existing literature on lip rejuvenation and perioral procedures related to lip rejuvenation. Additionally, this article aims to highlight the importance of addressing perioral areas alongside lip rejuvenation procedures, rather than solely focusing on lip rejuvenation. We also discussed the extensive procedures and materials used for lip rejuvenation, such as hyaluronic acid, botulinum toxin A, abobotulinum, onabotulinum, incobotulinum, prabobotulinum, fat grafts, silicone fillers, human collagen, collagen stimulating procedures such as derma pens and derma rolls, radiation frequency, stem cells, and plasma therapy, as well as the underlying factors that contribute to varying success rates. MATERIALS AND METHODS: A thorough literature search was done using PubMed, Cochrane, Ebsco search, Google Scholar, Scopus, and Web of Science for the articles pertaining to facial and lip cosmetic surgeries 1995-2020. Keywords for the search included anatomy of the face, facial aging, perioral areas, lip rejuvenation, botox, grafts, facelift, plastic surgery, stem cell therapy, plasma treatment, and cosmetic surgery. RESULTS: 37 articles met the study criteria. 14 out of 37 studies included procedures for lip and perioral region rejuvenation. The remaining 23 studies either involved lip procedures alone or lip procedures in conjunction with facial cosmetic procedures. Lip rejuvenation with perioral enhancement with hyaluronic acid gel demonstrated a 94.3% improvement on the lip fullness scale (LFS) one month after re-treatment. The amalgamation of lip and perioral region rejuvenation produces a synergistic effect. Whereas, sole lip rejuvenation procedures showed short-term results with less patient satisfaction, calling for secondary lip rejuvenation procedures. It was also observed that hyaluronic acid was the most commonly used agent for lip rejuvenation procedures with minimal or no side effects. CONCLUSIONS: In conjunction with perioral rejuvenation, lip rejuvenation procedures produce more aesthetically appealing results. However, any cosmetic surgical or non-surgical procedure is limited by the nature and composition of the products used. The use of FDA-approved products for rejuvenation is strongly advised to avoid undesirable side effects. Further extensive research is required on the long-term outcomes and adverse effects of stem cell transplants, such as tumor development.


Subject(s)
Cosmetic Techniques , Skin Aging , Humans , Lip/anatomy & histology , Hyaluronic Acid , Rejuvenation , Collagen
3.
Bioresour Technol ; 275: 109-122, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30579101

ABSTRACT

Ever-increasing swine wastewater (SW) has become a serious environmental concern. High levels of nutrients and toxic contaminants in SW significantly impact on the ecosystem and public health. On the other hand, swine wastewater is considered as valuable water and nutrient source for microalgae cultivation. The potential for converting the nutrients from SW into valuable biomass and then generating bioenergy from it has drawn increasing attention. For this reason, this review comprehensively discussed the biomass production, SW treatment efficiencies, and bioenergy generation potentials through cultivating microalgae in SW. Microalgae species grow well in SW with large amounts of biomass being produced, despite the impact of various parameters (e.g., nutrients and toxicants levels, cultivation conditions, and bacteria in SW). Pollutants in SW can effectively be removed by harvesting microalgae from SW, and the harvested microalgae biomass elicits high potential for conversion to valuable bioenergy.


Subject(s)
Biofuels , Biomass , Microalgae/metabolism , Wastewater , Animals , Swine
4.
J Int Soc Prev Community Dent ; 6(4): 285-90, 2016.
Article in English | MEDLINE | ID: mdl-27583214

ABSTRACT

AIM: The present study aims to compare the peri-implant bone status around immediately loaded dental implants treated with aminobisphosphonate solution and untreated control implants in terms of clinical and radiographical parameters. MATERIALS AND METHODS: A total of 24 patients were randomly divided equally into two groups. This study was conducted in accordance to the Helsinki's declaration of 1975, revised in 2000, and with the approval of the institutional ethical committee. In the control group after preparation, osteotomy sites were irrigated with normal saline solution, whereas in the test group osteotomy sites were irrigated with modified bisphosphonate solution and then TRX-OP, Hi-Tec dental implants were inserted. Clinical parameters, such as modified plaque and gingival index, probing depth, mobility, and radiographic parameters were recorded at baseline (0), 3, 6, and 9 months. Data analysis was performed using the Statistical Package for the Social Sciences version 17 for windows, and the statistical techniques employed were repeated measures analysis of variance, independent sample t-test, and paired sample t-test. RESULTS: Reduction in mean radiographic bone levels (height) was observed on the mesial and distal aspect of the control group in comparison to its baseline at all intervals. In the test group, there was reduction in mean radiographic bone levels on mesial and distal aspect of the implant site in comparison to its baseline till 6-month follow up, however, at 9 month, there was gain in bone level on both mesial and distal aspect of implant. This represents the effectiveness of sodium alendronate in enhancing the bone formation. On comparison, between both groups on mesial and distal aspect of implants, statistically significant differences were observed at 3 and 9 months on mesial and distal aspect, respectively, without any clinical evidence of mobility in the test group. CONCLUSION: Implant site treated with aminobisphosphonate solution represents greater efficacy in enhancing bone formation when used as an irrigant; thus, it is considered beneficial in implant dentistry.

5.
J Int Soc Prev Community Dent ; 6(Suppl 1): S47-52, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27195227

ABSTRACT

AIM AND OBJECTIVES: This study attempted the evaluation of the efficacy of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) in alveolar defects after removal of bilateral mandibular third molars. MATERIALS AND METHODS: A total of 30 patients reporting to Department of Oral and Maxillofacial Surgery and having bilateral mandibular third molar impaction in both male and female aged between 18 and 30 years were included in this study. PRF and PRP were placed in extraction site and recalled at 2(nd), 4(th), and 6(th) month postoperatively. Data were statistically analyzed using IBM SPSS software for Windows, version 19.0. IBM Corp., Armonk, NY, USA. RESULTS: This study showed decreased probing depth in PRF group compared to PRP and control one. This signifies a better soft tissue healing of extraction sockets with PRF as compared to the PRP and the control group and increase in the bone density highlights the use of PRP and PRF certainly as a valid method in inducing hard tissue regeneration. CONCLUSION: This study indicates a definite improvement in the periodontal health distal to second molar after third molar surgery in cases treated with PRF as compared to the PRP group and control group. Hence, PRP and PRF can be incorporated as an adjunct to promote wound healing and osseous regeneration in mandibular third molar extraction sites.

6.
Eur Spine J ; 25 Suppl 1: 75-9, 2016 05.
Article in English | MEDLINE | ID: mdl-26155896

ABSTRACT

INTRODUCTION: Inflammatory pseudotumors (IPTs) are benign lesions with unknown etiology, probably an immunological reaction to a traumatic or an infective insult or sometimes considered as an IgG4-related autoimmune disorder. It can occur as an isolated or multi-centric lesion and are reported to involve almost all parts of the human body. Although lung and orbital IPTs are reported commonly, central nervous system involvement is a rare occurrence. Only seven cases of spinal epidural IPTs have been reported to date. These are clinically and radiologically a diagnosis of exclusion. It is an exclusive histopathological diagnosis. CASE REPORT: We present here a 49-year-old female with 2 months history of progressive weakness in lower limbs, with no history suggestive of any traumatic, infective, inflammatory, or neoplastic pathology. Both clinical and radiological investigations were inconclusive. There was a mass lesion in the epidural space (predominantly in the posterior and right lateral space) at T1-T3 vertebral levels compressing the thoracic spinal cord. Considering the progressive nature of her neurological deficit, an emergency decompressive laminectomies of T1-T3 vertebrae were done with excision of the compressive mass lesion. Histopathological examination showed a rich lympho-plasmacytic cell infiltrates with storiform spindle cells and dense fibrosis, which was diagnostic of IPT. Post-operatively there was a rapid recovery in neurology and she became ambulatory at the end of 2 weeks. The purpose of this case report is to discuss the clinical, histopathological and radiological features, differential diagnosis, management, and prognosis of spinal IPT on the background of relevant literature review.


Subject(s)
Epidural Space , Granuloma, Plasma Cell/complications , Paraplegia/etiology , Diagnosis, Differential , Epidural Space/diagnostic imaging , Female , Granuloma, Plasma Cell/diagnostic imaging , Granuloma, Plasma Cell/pathology , Humans , Immunoglobulin G/analysis , Laminectomy , Middle Aged , Paraplegia/pathology , Spinal Cord Compression/etiology , Spinal Cord Compression/pathology , Thoracic Vertebrae/diagnostic imaging , Thoracic Vertebrae/surgery
7.
Indian J Tuberc ; 62(1): 43-5, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25857565

ABSTRACT

A 29 year old lady presented with vague right lower quadrant abdomen and thigh pain for the past 4 years. X-ray pelvis with both hips was remarkably normal, and MRI was suggestive of osteomyelitis in right ilium and proximal femur. Biopsy confirmed the lesion as tubercular. Isolated bone involvement by tuberculosis without a joint or pulmonary involvement is extremely rare in immunocompetent patients and has not been reported in literature so for. Tuberculosis should be suspected in patients presenting with multiple bone lesions, especially in endemic areas. Prompt surgical drainage and ATT forms the mainstay of treatment.


Subject(s)
Antitubercular Agents/administration & dosage , Drainage/methods , Femur , Ilium , Osteomyelitis , Tuberculosis, Osteoarticular , Adult , Biopsy , Female , Femur/pathology , Femur/surgery , Humans , Ilium/pathology , Ilium/surgery , Magnetic Resonance Imaging , Osteomyelitis/diagnosis , Osteomyelitis/physiopathology , Osteomyelitis/therapy , Tomography, X-Ray Computed , Treatment Outcome , Tuberculosis, Osteoarticular/diagnosis , Tuberculosis, Osteoarticular/physiopathology , Tuberculosis, Osteoarticular/therapy
8.
Biochem Biophys Res Commun ; 459(1): 113-7, 2015 Mar 27.
Article in English | MEDLINE | ID: mdl-25724946

ABSTRACT

The ATP binding cassette (ABC) transporters, represent one of the largest superfamilies of primary transporters, which are very essential for various biological functions. The crystal structure of ATP-binding subunit of an ABC transporter from Geobacillus kaustophilus has been determined at 1.77 Å resolution. The crystal structure revealed that the protomer has two thick arms, (arm I and II), which resemble 'L' shape. The ATP-binding pocket is located close to the end of arm I. ATP molecule is docked into the active site of the protein. The dimeric crystal structure of ATP-binding subunit of ABC transporter from G. kaustophilus has been compared with the previously reported crystal structure of ATP-binding subunit of ABC transporter from Salmonella typhimurium.


Subject(s)
ATP-Binding Cassette Transporters/chemistry , ATP-Binding Cassette Transporters/metabolism , Geobacillus/chemistry , Adenosine Triphosphate/metabolism , Amino Acid Sequence , Amino Acid Transport Systems, Basic/chemistry , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Binding Sites , Crystallography, X-Ray , Models, Molecular , Molecular Docking Simulation , Molecular Sequence Data , Protein Conformation , Protein Multimerization , Sequence Alignment
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 133: 677-82, 2014 Dec 10.
Article in English | MEDLINE | ID: mdl-24996209

ABSTRACT

Transparent crystal of glycine barium nitrate (GBN) has been grown from aqueous solution by slow evaporation technique at room temperature. Powder XRD study reveals the crystalline nature of the grown sample. Single crystal XRD study shows that the GBN belongs to orthorhombic crystal system. FTIR spectral study confirms the presence of the functional groups in the grown crystal. The presence of wide transparency window in the UV-visible region makes GBN crystal suitable for opto-electronic device applications. The grown sample has SHG efficiency is 0.8 times that of standard KDP crystal. Dielectric studies reveal that both dielectric constant and dielectric loss decreases with increase in frequency. Photoconductivity study confirms the negative photoconducting nature of the crystal.


Subject(s)
Barium Compounds/chemistry , Glycine/analogs & derivatives , Barium Compounds/chemical synthesis , Crystallization , Glycine/chemical synthesis , Nitrates/chemical synthesis , Nitrates/chemistry , Spectrophotometry, Ultraviolet , Spectroscopy, Fourier Transform Infrared , X-Ray Diffraction
10.
Biochem Biophys Res Commun ; 451(1): 126-30, 2014 Aug 15.
Article in English | MEDLINE | ID: mdl-25065739

ABSTRACT

In the L-Serine biosynthesis, D-3-phosphoglycerate dehydrogenase (PGDH) catalyzes the inter-conversion of D-3-phosphoglycerate to phosphohydroxypyruvate. PGDH belongs to 2-hydroxyacid dehydrogenases family. We have determined the crystal structures of PGDH from Sulfolobus tokodaii (StPGDH) and Pyrococcus horikoshii (PhPGDH) using X-ray diffraction to resolution of 1.77Å and 1.95Å, respectively. The PGDH protomer from both species exhibits identical structures, consisting of substrate binding domain and nucleotide binding domain. The residues and water molecules interacting with the NAD are identified. The catalytic triad residues Glu-His-Arg are highly conserved. The residues involved in the dimer interface and the structural features responsible for thermostability are evaluated. Overall, structures of PGDHs with two domains and histidine at the active site are categorized as type IIIH and such PGDHs structures having this type are reported for the first time.


Subject(s)
Phosphoglycerate Dehydrogenase/chemistry , Pyrococcus horikoshii/enzymology , Sulfolobus/enzymology , Archaeal Proteins/chemistry , Archaeal Proteins/genetics , Archaeal Proteins/metabolism , Binding Sites , Catalytic Domain , Crystallography, X-Ray , Enzyme Stability , Models, Molecular , NAD/metabolism , Phosphoglycerate Dehydrogenase/genetics , Phosphoglycerate Dehydrogenase/metabolism , Protein Conformation , Protein Multimerization
11.
Biochem Biophys Res Commun ; 449(1): 107-13, 2014 Jun 20.
Article in English | MEDLINE | ID: mdl-24832735

ABSTRACT

NADP(+) dependent isocitrate dehydrogenase (IDH) is an enzyme catalyzing oxidative decarboxylation of isocitrate into oxalosuccinate (intermediate) and finally the product α-ketoglutarate. The crystal structure of Thermus thermophilus isocitrate dehydrogenase (TtIDH) ternary complex with citrate and cofactor NADP(+) was determined using X-ray diffraction method to a resolution of 1.80 Å. The overall fold of this protein was resolved into large domain, small domain and a clasp domain. The monomeric structure reveals a novel terminal domain involved in dimerization, very unique and novel domain when compared to other IDH's. And, small domain and clasp domain showing significant differences when compared to other IDH's of the same sub-family. The structure of TtIDH reveals the absence of helix at the clasp domain, which is mainly involved in oligomerization in other IDH's. Also, helices/beta sheets are absent in the small domain, when compared to other IDH's of the same sub family. The overall TtIDH structure exhibits closed conformation with catalytic triad residues, Tyr144-Asp248-Lys191 are conserved. Oligomerization of the protein is quantized using interface area and subunit-subunit interactions between protomers. Overall, the TtIDH structure with novel terminal domain may be categorized as a first structure of subfamily of type IV.


Subject(s)
Isocitrate Dehydrogenase/chemistry , Isocitrate Dehydrogenase/ultrastructure , Models, Chemical , Models, Molecular , Thermus thermophilus/enzymology , Amino Acid Sequence , Binding Sites , Computer Simulation , Crystallization , Molecular Sequence Data , Protein Binding , Protein Conformation , Protein Structure, Tertiary
12.
Oncogene ; 33(7): 832-41, 2014 Feb 13.
Article in English | MEDLINE | ID: mdl-23334329

ABSTRACT

Adult stem cells are multipotent and persist in small numbers in adult tissues throughout the lifespan of an organism. Unlike differentiated cells, adult stem cells are intrinsically resistant to senescence. It is unclear how adult stem cells in solid organs respond to oncogenic stimulation and whether these cells have a role in tumor initiation. We report here that expression of BRAF(V600E) in human neural crest progenitor cells (hNCPCs) did not induce growth arrest as seen in human melanocytes, but instead, increased their cell proliferation capacity. These cells (hNCPCs(V600E)) acquired anchorage-independent growth ability and were weakly tumorigenic in vivo. Unlike in human melanocytes, BRAF(V600E) expression in hNCPCs did not induce p16(INK4a) expression. BRAF(V600E) induced elevated expression of CDK2, CDK4, MITF and EST1/2 protein in hNCPCs, and also induced melanocytic differentiation of these cells. Furthermore, overexpression of MITF in hNCPCs(V600E) dramatically increased their tumorigenicity and resulted in fully transformed tumor cells. These findings indicate that hNCPCs are susceptible to BRAF(V600E)-induced transformation, and MITF potentiates the oncogenic effect of BRAF(V600E) in these progenitor cells. These results suggest that the hNCPCs are potential targets for BRAF(V600E)-induced melanocytic tumor formation.


Subject(s)
Adult Stem Cells/metabolism , Cell Transformation, Neoplastic/genetics , Neural Crest/pathology , Neural Stem Cells/metabolism , Proto-Oncogene Proteins B-raf/genetics , Skin/pathology , Adult Stem Cells/pathology , Animals , Cell Proliferation , Cell Transformation, Neoplastic/metabolism , Cell Transformation, Neoplastic/pathology , Cells, Cultured , DNA Copy Number Variations , Female , Gene Expression , Humans , Male , Melanoma/genetics , Melanoma/metabolism , Melanoma/pathology , Mice, Inbred NOD , Mice, SCID , Microphthalmia-Associated Transcription Factor/genetics , Mutation, Missense , Neoplasm Transplantation , Neural Stem Cells/pathology , Phenotype , Proto-Oncogene Proteins B-raf/metabolism , Tumor Burden
13.
Public Health Action ; 3(Suppl 1): S38-42, 2013 Nov 04.
Article in English | MEDLINE | ID: mdl-26393068

ABSTRACT

SETTING: Two tertiary care hospitals and 12 peripheral health institutions (PHIs) in Trivandrum, Kerala, India. OBJECTIVE: To determine factors associated with the prevalence of diabetes mellitus (DM) among tuberculosis (TB) patients and examine differences in the proportion of new DM cases among TB patients diagnosed at tertiary care centres and PHIs. DESIGN: A descriptive study: TB patients diagnosed during March-September 2012 were screened for known DM. Those with unknown DM status were tested for random blood glucose and fasting blood glucose (FBG); FBG ≥ 126 mg/dl was diagnosed as new DM. RESULTS: Of 920 TB patients, 689 (72%) were male and the mean (standard deviation) age was 47.6 (16.4) years. Of these, 298 (32.4%) were diabetic: 235 (26%) had previously known DM and 63 (7%) were newly diagnosed. During the screening at PHIs and tertiary care hospitals, respectively 30/183 (16.4%) and 33/737 (4.5%) were newly diagnosed with DM (OR 3.71; 95%CI 2.17-6.32). Overall, age >50 years and pulmonary tuberculosis were independently associated with a higher prevalence of diabetes. CONCLUSION: As nearly one in three TB patients had DM, we recommend that TB patients should be routinely screened for DM in Kerala. As the proportion of new DM was higher among TB patients diagnosed at PHIs, we would recommend that specific attention and investment be directed to PHIs.

14.
Biosens Bioelectron ; 35(1): 413-415, 2012 May 15.
Article in English | MEDLINE | ID: mdl-22424752

ABSTRACT

Because of the advantages of low cost, good electrical conductivity and high oxidation resistance, nitrogen-doped carbon (NDC) materials have a potential to replace noble metals in microbial fuel cells (MFCs) for wastewater treatment. In spite of a large volume of studies on NDC materials as catalysts for oxygen reduction reaction, the influence of sulfide on NDC materials has not yet been explicitly reported so far. In this communication, nitrogen-doped carbon powders (NDCP) were prepared by treating carbon powders in nitric acid under reflux condition. Sodium sulfide (Na(2)S) was added to the cathodic electrolyte to compare its effects on platinum (Pt) and NDCP cathodes. Cell voltages, power density and cathodic potentials were monitored without and with Na(2)S and after Na(2)S was removed. The maximum cell voltage of the MFCs with Pt cathode decreased by 10% in the presence of Na(2)S that did not change the performance of the MFC with NDCP cathode, and the maximum power density of the MFC with NDCP cathode was even 11.3% higher than that with Pt cathode (222.5 ± 8 mW m(-2) vs. 199.7 ± 4 mW m(-2)).


Subject(s)
Bioelectric Energy Sources/microbiology , Sulfides/pharmacology , Carbon , Electric Conductivity , Electrodes , Equipment Design , Hydrogen-Ion Concentration , Nitrogen , Oxidation-Reduction , Platinum
15.
Oncogene ; 31(47): 4898-911, 2012 Nov 22.
Article in English | MEDLINE | ID: mdl-22286766

ABSTRACT

There is enormous interest to target cancer stem cells (CSCs) for clinical treatment because these cells are highly tumorigenic and resistant to chemotherapy. Oct4 is expressed by CSC-like cells in different types of cancer. However, function of Oct4 in tumor cells is unclear. In this study, we showed that expression of Oct4 gene or transmembrane delivery of Oct4 protein promoted dedifferentiation of melanoma cells to CSC-like cells. The dedifferentiated melanoma cells showed significantly decreased expression of melanocytic markers and acquired the ability to form tumor spheroids. They showed markedly increased resistance to chemotherapeutic agents and hypoxic injury. In the subcutaneous xenograft and tail vein injection assays, these cells had significantly increased tumorigenic capacity. The dedifferentiated melanoma cells acquired features associated with CSCs such as multipotent differentiation capacity and expression of melanoma CSC markers such as ABCB5 and CD271. Mechanistically, Oct4-induced dedifferentiation was associated with increased expression of endogenous Oct4, Nanog and Klf4, and global gene expression changes that enriched for transcription factors. RNAi-mediated knockdown of Oct4 in dedifferentiated cells led to diminished CSC phenotypes. Oct4 expression in melanoma was regulated by hypoxia and its expression was detected in a sub-population of melanoma cells in clinical samples. Our data indicate that Oct4 is a positive regulator of tumor dedifferentiation. The results suggest that CSC phenotype is dynamic and may be acquired through dedifferentiation. Oct4-mediated tumor cell dedifferentiation may have an important role during tumor progression.


Subject(s)
Cell Dedifferentiation , Neoplastic Stem Cells/metabolism , Octamer Transcription Factor-3/physiology , Phenotype , Animals , Cell Hypoxia , Cell Line, Tumor , Cell Movement , Cell Proliferation , Cell Shape , Cell Survival , Gene Expression Regulation, Neoplastic , Genes, Reporter , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Kruppel-Like Factor 4 , Kruppel-Like Transcription Factors/genetics , Kruppel-Like Transcription Factors/metabolism , Melanoma/metabolism , Melanoma/pathology , Mice , Mice, Inbred NOD , Mice, SCID , Nanog Homeobox Protein , Neoplasm Transplantation , Neoplastic Stem Cells/physiology , Octamer Transcription Factor-3/genetics , Octamer Transcription Factor-3/metabolism , Promoter Regions, Genetic , Spheroids, Cellular/metabolism , Transcriptome
16.
Bioresour Technol ; 108: 89-93, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22265594

ABSTRACT

Given few in-depth studies available on the application of nitrogen-doped carbon powders (NDCP) to air-cathode microbial fuel cells (ACMFCs), a low-cost and durable catalyst of NDCP was prepared and used as cathodic catalyst of ACMFCs. Compared to the untreated carbon powders, the N-doped treatment significantly increased the maximum power density (MPD) of ACMFC. A two-step pretreatment of heat treatment and hydrochloric acid immersion can further obviously increase the MPD. With a reasonably large loading of catalyst, the MPD of NDCP based ACMFC was comparable to that of carbon-supported platinum (Pt/C) based ACMFC, while the cost was dramatically reduced. The pretreatment increased the key nitrogen functional groups, pyridinic-like and pyrrolic-like nitrogen. A third new key nitrogen functional group, nitrogen oxide, was discovered and the mechanism of its contribution was explained. Compared to the inherent deterioration problem of Pt/C, NDCP exhibited high stability and was superior for long-term operation of ACMFCs.


Subject(s)
Bioelectric Energy Sources , Carbon/chemistry , Electrodes , Nitrogen/chemistry , Catalysis , Hot Temperature , Hydrochloric Acid
17.
Oncogene ; 31(13): 1649-60, 2012 Mar 29.
Article in English | MEDLINE | ID: mdl-21860424

ABSTRACT

Erythropoietin (Epo) is widely used clinically to treat anemia associated with various clinical conditions including cancer. Data from several clinical trials suggest significant adverse effect of Epo treatment on cancer patient survival. However, controversy exists whether Epo receptor (EpoR) is functional in cancer cells. In this study, we demonstrated that EpoR mRNA expression was detectable in 90.1% of 65 melanoma cell lines, and increased copy number of the Epo and EpoR loci occurred in 30 and 24.6% of 130 primary melanomas, respectively. EpoR knockdown in melanoma cells resulted in diminished ERK phosphorylation in response to Epo stimulation, decreased cell proliferation and increased response to the inhibitory effect of hypoxia and cisplatin in vitro. EpoR knockdown significantly decreased melanoma xenograft size and tumor invasion in vivo. On the contrary, constitutive activation of EpoR activated cell proliferation pathways in melanoma cells and resulted in increased cell proliferation and resistance to hypoxia and cisplatin treatment in vitro. EpoR activation resulted in significantly larger xenografts with increased tumor invasion of surrounding tissue in vivo. Daily administration of recombinant Epo fails to stimulate melanoma growth in vivo, but the treatment increased vascular size in the xenografts. Increased local recurrence after excision of the primary tumors was observed after Epo treatment. Epo induced angiogenesis in Matrigel plug assays, and neutralization of Epo secreted by melanoma cells results in decreased angiogenesis. These data support that EpoR is functional in melanoma and EpoR activation may promote melanoma progression, and suggest that Epo may stimulate angiogenesis and increase survival of melanoma cells under hypoxic condition in vivo.


Subject(s)
Erythropoietin/adverse effects , Melanoma/genetics , Receptors, Erythropoietin/genetics , Skin Neoplasms/genetics , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , DNA Copy Number Variations , Disease Progression , Epoetin Alfa , Erythropoietin/genetics , Gene Knockdown Techniques , Humans , Melanoma/metabolism , Mice , Mice, Nude , Neoplasm Transplantation , Neovascularization, Pathologic , Recombinant Proteins/adverse effects , Signal Transduction/drug effects , Transcriptional Activation
18.
Bioresour Technol ; 101(14): 5250-5, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20171090

ABSTRACT

The catalytic activity of modified carbon powder (Vulcan XC-72R) for oxygen reduction reaction (ORR) in an air-breathing cathode of a microbial fuel cell (MFC) has been investigated. Chemical modification was carried out by using various chemicals, namely 5% nitric acid, 0.2N phosphoric acid, 0.2N potassium hydroxide and 10% hydrogen peroxide. Electrochemical study was performed for ORR of these modified carbon materials in the buffer solution pH range of 6-7.5 in the anodic compartment. Although, these treatments influenced the surface properties of the carbon material, as evident from the SEM-EDX analysis, treatment with H(2)PO(4), KOH, and H(2)O(2) did not show significant activity during the electrochemical test. The HNO(3) treated Vulcan demonstrated significant ORR activity and when used in the single-chamber MFC cathode, current densities (1115mA/m(2), at 5.6mV) greater than those for a Pt-supported un-treated carbon cathode were achieved. However, the power density for the latter was higher. Such chemically modified carbon material can be a cheaper alternative for expensive platinum catalyst used in MFC cathode construction.


Subject(s)
Bioelectric Energy Sources , Electrodes , Air , Catalysis , Electrochemistry/methods , Equipment Design , Hydrogen Peroxide/chemistry , Hydroxides/chemistry , Microscopy, Electron, Scanning/methods , Nitric Acid/chemistry , Phosphoric Acids/chemistry , Platinum/chemistry , Potassium Compounds/chemistry , Water Pollutants, Chemical , Water Purification/methods
19.
Med Chem ; 4(5): 457-65, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18782042

ABSTRACT

A series of N10-substituted-2-methyl acridone derivatives are synthesized and are examined for its ability to reverse P-glycoprotein (P-gp) mediated multidrug resistance (MDR) in breast cancer cell lines MCF-7 and MCF-7/Adr. The structural requirement of in-vitro anti-cancer and reversal of drug resistance are studied. The results showed that compound 16 with four carbon spacer exhibited promising in-vitro anti-cancer and reversal of drug resistance in comparison to the other analogues.


Subject(s)
Acridones/pharmacology , Antineoplastic Agents/pharmacology , Drug Resistance, Neoplasm , Multidrug Resistance-Associated Proteins/antagonists & inhibitors , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Acridones/chemical synthesis , Antineoplastic Agents/chemical synthesis , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor/drug effects , Cell Line, Tumor/pathology , Humans , Models, Chemical
20.
Chem Biol Interact ; 176(2-3): 212-9, 2008 Nov 25.
Article in English | MEDLINE | ID: mdl-18638463

ABSTRACT

We report herein in vitro anti-proliferative activity and duplex DNA complex studies of a series of N10-substituted acridone derivatives. All the molecules have been designed on the basis of the presence of specific recognition patterns consisting of hydrogen bond acceptors (or electron donors), carbonyl, chloro groups with precise spatial separation and structural features (lipophilicity, positive charge at neutral pH and presence of aromatic rings). The in vitro cytotoxic effects have been demonstrated against human promyelocytic leukemia sensitive cell line (HL-60), including its multidrug cross-resistance of two main (P-gp and MRP) phenotype sublines vincristine-resistant (HL-60/VINC) and doxorubicin-resistant (HL-60/DX) cancer cell lines. Compound 4 showed very good activity against sensitive and resistant cell lines. The noncovalent complexes of these molecules with DNA duplex has been investigated in gas phase by using a fast, robust and sensitive electrospray ionization mass spectrometry (ESI-MS) technique. Equilibrium association constants (K1) and percentage of intact complexes were determined. The combined results show that these acridone derivatives interact with DNA duplex by intercalation between the base pairs, possess higher affinity to GC than AT base pairs of the DNA and they could not interact noncovalently with the minor grooves of the DNA in solution-free gas phase. Examination of the relationship between lipophilicity and cytotoxic properties of acridone derivatives showed a poor correlation. The in vitro cytotoxic studies in resistant cancer cell lines of compound 4 showed that it might be a promising new hit for further development of anti-MDR agent.


Subject(s)
Acridones/chemistry , Acridones/toxicity , DNA/chemistry , DNA/drug effects , Drug Resistance, Multiple , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , HL-60 Cells , Humans , Molecular Structure , Molecular Weight , Spectrometry, Mass, Electrospray Ionization , Stereoisomerism , Structure-Activity Relationship
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