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1.
Rev Sci Instrum ; 90(12): 124502, 2019 Dec 01.
Article in English | MEDLINE | ID: mdl-31893794

ABSTRACT

Micropore optics have recently been implemented in a lobster eye geometry as a compact X-ray telescope. Fields generated by rare-earth magnets are used to reduce the flux of energetic electrons incident upon the focal plane detector in such a setup. We present the design and implementation of the electron diverters for X-ray telescopes of two upcoming missions: the microchannel X-ray telescope onboard the space-based multiband astronomical variable objects monitor and the soft X-ray instrument onboard the solar wind magnetosphere ionosphere link explorer. Electron diverters must be configured to conform to stringent limits on their total magnetic dipole moment and be compensated for any net moment arising from manufacturing errors. The two missions have differing designs, which are presented and evaluated in terms of the fractions of electrons reaching the detector, as determined by relativistic calculations of electron trajectories. The differential flux of electrons to the detector is calculated, and the integrated electron background is determined for both designs.

2.
HLA ; 90(5): 295-299, 2017 11.
Article in English | MEDLINE | ID: mdl-28800212

ABSTRACT

A much larger sample (N = 2369) was used to evaluate a previously reported distribution of the A, AB and B blood group phenotypes in rhesus and cynomolgus macaques from six different regional populations. These samples, acquired from 15 different breeding and research facilities in the United States, were analyzed using a real-time quantitative polymerase chain reaction (qPCR) assay that targets single nucleotide polymorphisms (SNPs) responsible for the macaque A, B and AB phenotypes. The frequency distributions of blood group phenotypes of the two species differ significantly from each other and significant regional differentiation within the geographic ranges of each species was also observed. The B blood group phenotype was prevalent in rhesus macaques, especially those from India, while the frequencies of the A, B and AB phenotypes varied significantly among cynomolgus macaques from different geographic regions. The Mauritian cynomolgus macaques, despite having originated in Indonesia, showed significant (P ≪ .01) divergence from the Indonesian animals at the ABO blood group locus. Most Mauritian animals belonged to the B blood group while the Indonesian animals were mostly A. The close similarity in blood group frequency distributions between the Chinese rhesus and Indochinese cynomolgus macaques demonstrates that the introgression between these two species extends beyond the zone of intergradation in Indochina. This study underscores the importance of ABO blood group phenotyping of the domestic supply of macaques and their biospecimens.


Subject(s)
ABO Blood-Group System/metabolism , Blood Grouping and Crossmatching/methods , Animals , Geography , Macaca fascicularis , Macaca mulatta , Phenotype , Species Specificity
3.
Leukemia ; 30(11): 2133-2141, 2016 11.
Article in English | MEDLINE | ID: mdl-27416986

ABSTRACT

Acute lymphoblastic leukemia (ALL) in children exemplifies how multi-agent chemotherapy has improved the outcome for patients. Refinements in treatment protocols and improvements in supportive care for this most common pediatric malignancy have led to a cure rate that now approaches 90%. However, certain pediatric ALL subgroups remain relatively intractable to treatment and many patients who relapse face a similarly dismal outcome. Moreover, survivors of pediatric ALL suffer the long-term sequelae of their intensive treatment throughout their lives. Therefore, the development of drugs to treat relapsed/refractory pediatric ALL, as well as those that more specifically target leukemia cells, remains a high priority. As pediatric malignancies represent a minority of the overall cancer burden, it is not surprising that they are generally underrepresented in drug development efforts. The identification of novel therapies relies largely on the reappropriation of drugs developed for adult malignancies. However, despite the large number of experimental agents available, clinical evaluation of novel drugs for pediatric ALL is hindered by limited patient numbers and the availability of effective established drugs. The Pediatric Preclinical Testing Program (PPTP) was established in 2005 to provide a mechanism by which novel therapeutics could be evaluated against xenograft and cell line models of the most common childhood malignancies, including ALL, to prioritize those with the greatest activity for clinical evaluation. In this article, we review the results of >50 novel agents and combinations tested against the PPTP ALL xenografts, highlighting comparisons between PPTP results and clinical data where possible.


Subject(s)
Antineoplastic Agents/therapeutic use , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Child , Humans , Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology , Salvage Therapy/trends , Xenograft Model Antitumor Assays
4.
Top Spinal Cord Inj Rehabil ; 22(4): 277-287, 2016.
Article in English | MEDLINE | ID: mdl-29339869

ABSTRACT

Background: Electrical stimulation therapy (EST) has been shown to be an effective therapy for managing pressure ulcers in individuals with spinal cord injury (SCI). However, there is a lack of uptake of this therapy, and it is often not considered as a first-line treatment, particularly in the community. Objective: To develop a pressure ulcer model of care that is adapted to the local context by understanding the perceived barriers and facilitators to implementing EST, and to describe key initial phases of the implementation process. Method: Guided by the Knowledge-to-Action (KTA) and National Implementation Research Network (NIRN) frameworks, a community-based participatory research (CBPR) approach was used to complete key initial implementation processes including (a) defining the practice, (b) identifying the barriers and facilitators to EST implementation and organizing them into implementation drivers, and (c) developing a model of care that is adapted to the local environment. Results: A model of care for healing pressure ulcers with EST was developed for the local environment while taking into account key implementation barriers including lack of interdisciplinary collaboration and communication amongst providers between and across settings, inadequate training and education, and lack of resources, such as funding, time, and staff. Conclusions: Using established implementation science frameworks with structured planning and engaging local stakeholders are important exploratory steps to achieve a successful sustainable best practice implementation project.


Subject(s)
Community-Based Participatory Research , Electric Stimulation Therapy , Pressure Ulcer/therapy , Spinal Cord Injuries/complications , Communication , Humans , Pressure Ulcer/etiology
5.
Oncogenesis ; 4: e149, 2015 May 18.
Article in English | MEDLINE | ID: mdl-25985210

ABSTRACT

Sgt1/Sugt1, a cochaperone of Hsp90, is involved in several cellular activities including Cullin E3 ubiqutin ligase activity. The high level of Sgt1 expression in colorectal and gastric tumors suggests that Sgt1 is involved in tumorigenesis. Here, we report that Sgt1 is overexpressed in colon, breast and lung tumor tissues and in Ewing sarcoma and rhabdomyosarcoma xenografts. We also found that Sgt1 heterozygous knockout resulted in suppressed Hras-mediated transformation in vitro and tumor formation in p53(-/-) mouse embryonic fibroblast cells and significantly increased survival of p53(-/-) mice. Moreover, depletion of Sgt1 inhibited the growth of Ewing sarcoma and rhabdomyosarcoma cells and destabilized EWS-FLI1 and PAX3-FOXO1 oncogenic fusion proteins, respectively, which are required for cellular growth. Our results suggest that Sgt1 contributes to cancer development by stabilizing oncoproteins and that Sgt1 is a potential therapeutic target.

6.
J Parasitol Res ; 2013: 703781, 2013.
Article in English | MEDLINE | ID: mdl-23970954

ABSTRACT

Cajanus cajan L, a member of the family Fabaceae, was identified from the Nigerian antimalarial ethnobotany as possessing antimalarial properties. The bioassay-guided fractionation of the crude methanol extract of C. cajan leaves was done in vitro using the multiresistant strain of Plasmodium falciparum (K1) in the parasite lactate dehydrogenase assay. Isolation of compound was achieved by a combination of chromatographic techniques, while the structure of the compound was elucidated by spectroscopy. This led to the identification of a cajachalcone, 2',6'-dihydroxy-4-methoxy chalcone, as the biologically active constituent from the ethyl acetate fraction. Cajachalcone had an IC50 value of 2.0 µ g/mL (7.4 µ M) and could be a lead for anti-malarial drug discovery.

7.
J Med Primatol ; 42(3): 120-31, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23480663

ABSTRACT

BACKGROUND: The genetic composition of cynomolgus macaques used in biomedical research is not as well-characterized as that of rhesus macaques. METHODS: Populations of cynomolgus macaques from Sumatra, Corregidor, Mauritius, Singapore, Cambodia, and Zamboanga were analyzed using 24 STRs. RESULTS: The Sumatran and Cambodian populations exhibited the highest allelic diversity, while the Mauritian population exhibited the lowest. Sumatran cynomolgus macaques were the most genetically similar to all others, consistent with an Indonesian origin of the species. The high diversity among Cambodian animals may result from interbreeding with rhesus macaques. The Philippine and Mauritian samples were the most divergent from other populations, the former due to separation from the Sunda Shelf by deepwater and the latter due to anthropogenic translocation and extreme founder effects. CONCLUSIONS: Investigators should verify their research subjects' origin, ancestry, and pedigree to minimize risks to biomedical experimentation from genetic variance stemming from close kinship and mixed ancestry as these can obscure treatment effects.


Subject(s)
Animals, Laboratory/genetics , Genetic Variation , Macaca fascicularis/genetics , Animals , Asia, Southeastern , Geography , Mauritius , Microsatellite Repeats
8.
Tissue Antigens ; 80(4): 363-7, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22861170

ABSTRACT

Macaques are commonly used in biomedical research as animal models of human disease. The ABO phenotype of donors and recipients plays an important role in the success of transplantation and stem cell research of both human and macaque tissue. Traditional serological methods for ABO phenotyping can be time consuming, provide ambiguous results and/or require tissue that is unavailable or unsuitable. We developed a novel method to detect the A, B, and AB phenotypes of macaques using real-time quantitative polymerase chain reaction. This method enables the simple and rapid screening of these phenotypes in macaques without the need for fresh blood or saliva. This study reports the distribution of the A, B, and AB phenotypes of captive cynomolgus macaques that, while regionally variable, closely resembles that of rhesus macaques. Blood group B, as in rhesus macaques, predominates in cynomolgus macaques and its frequency distribution leads to a probability of major incompatibility of 41%. No silencing mutations have been identified in exon 6 or 7 in macaques that could be responsible for the O phenotype, that, although rare, have been reported. The excess homozygosity of rhesus and cynomolgus macaque genotypes in this study, that assumes the absence of the O allele, suggests the possibility of some mechanism preventing the expression of the A and B transferases.


Subject(s)
ABO Blood-Group System/genetics , Genetic Loci/immunology , Macaca fascicularis/genetics , Molecular Typing/methods , ABO Blood-Group System/immunology , Alleles , Animals , Base Sequence , DNA Primers , Exons , Homozygote , Humans , Macaca fascicularis/immunology , Macaca mulatta/genetics , Macaca mulatta/immunology , Molecular Sequence Data , Phenotype , Real-Time Polymerase Chain Reaction , Sequence Analysis, DNA , Species Specificity
9.
Postgrad Med J ; 87(1029): 450-2, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21459778

ABSTRACT

OBJECTIVE: To assess the understanding of commonly used abbreviations in the medical records among healthcare professionals. METHODS: A selection of abbreviations from surgical inpatient admissions (gathered over a 10 day period in October 2008), in the form of a standard questionnaire, was shown to different members of a multidisciplinary team to examine interpretation and knowledge. RESULTS: 209 questionnaires were analysed. The average correct response was 43%. Foundation Year 1 (F1) doctors scored the highest with 57% correct responses, whereas dieticians fared worst (20% correct). Among different abbreviations, NAD (91%) and SCBU (93%) were most often correctly answered, whereas CIC (3%) and STS (0.5%) were the most incorrectly answered. Certain abbreviations which are mostly used by nurses (eg, OTT) achieved a 75% correct response by them compared to only 11% by F1 and 10% by F2 doctors (p<0.001). Similarly, abbreviations such as COBH (p=0.025) and LUTS (p<0.001), although mostly correctly answered by junior doctors, were very poorly answered by nurses. CONCLUSION: The majority of healthcare professionals have a very poor knowledge of commonly used abbreviations. Use of unambiguous and approved list of abbreviations is suggested in order to ensure good communication in patient care.


Subject(s)
Abbreviations as Topic , Health Personnel/education , Medical Errors/prevention & control , Medical Records/standards , Cross-Sectional Studies , Humans , Surveys and Questionnaires
10.
J Ethnopharmacol ; 128(2): 501-12, 2010 Mar 24.
Article in English | MEDLINE | ID: mdl-20064598

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: There is only scant literature on the anticancer components of medicinal plants from Nigeria, yet traditional healers in the area under study claim to have been managing the disease in their patients with some success using the species studied. AIM OF STUDY: To document plants commonly used to treat cancer in South-western Nigeria and to test the scientific basis of the claims using in vitro cytotoxicity tests. METHODS: Structured questionnaires were used to explore the ethnobotanical practices amongst the traditional healers. Methanol extracts of the most common species cited were screened for cytotoxicity using the sulforhodamine B (SRB) assay in both exposure and recovery experiments. Three cancer cell lines (human breast adenocarcinoma cell line MCF-7, human large cell lung carcinoma cell line COR-L23 and human amelanotic melanoma C32) and one normal cell line (normal human keratinocytes SVK-14) were used for the screening of the extracts and the fractions obtained. The extract of Cajanus cajan showed considerable activity and was further partitioned and the dichloromethane fraction was subjected to preparative chomatography to yield six compounds: hexadecanoic acid methyl ester, alpha-amyrin, beta-sitosterol, pinostrobin, longistylin A and longistylin C. Pinostrobin and longistylins A and C were tested for cytotoxicity on the cancer cell lines. In addition, an adriamycin-sensitive acute T-lymphoblastic leukaemia cell line (CCRF-CEM) and its multidrug-resistant sub-line (CEM/ADR5000) were used in an XTT assay to evaluate the activity of the pure compounds obtained. RESULTS: A total of 30 healers from S W Nigeria were involved in the study. 45 species were recorded with their local names with parts used in the traditional therapeutic preparations. Cytotoxicity (IC(50) values less than 50 microg/mL) was observed in 5 species (Acanthospermum hispidum, Cajanus cajan, Morinda lucida, Nymphaea lotus and Pycnanthus angolensis). Acanthospermum hispidum and Cajanus cajan were the most active. The dichloromethane fraction of Cajanus cajan had IC(50) value 5-10 microg/mL, with the two constituent stilbenes, longistylins A and C, being primarily responsible, with IC(50) values of 0.7-14.7 microM against the range of cancer cell lines. CONCLUSIONS: Most of the species tested had some cytotoxic effect on the cancer cell lines, which to some extent supports their traditional inclusion in herbal preparations for treatment of cancer. However, little selectivity for cancer cells was observed, which raises concerns over their safety and efficacy in traditional treatment. The longistylins A and C appear to be responsible for much of the activity of Cajanus cajan extract.


Subject(s)
Cajanus/chemistry , Ethnobotany , Neoplasms/drug therapy , Plants, Medicinal/chemistry , Plants/chemistry , Cell Line, Tumor , Data Collection , Ethnopharmacology , Flavanones/isolation & purification , Flavanones/toxicity , Humans , Male , Nigeria , Oleanolic Acid/analogs & derivatives , Oleanolic Acid/isolation & purification , Oleanolic Acid/toxicity , Plant Leaves/chemistry , Sitosterols/isolation & purification , Sitosterols/toxicity
11.
J Ethnopharmacol ; 122(2): 410-5, 2009 Mar 18.
Article in English | MEDLINE | ID: mdl-19121378

ABSTRACT

OBJECTIVE: To investigate the toxicity of an ethanolic extract of the aerial parts of Tithonia diversifolia, used in Nigeria to treat malaria, in rats. MATERIALS AND METHODS: A 70% ethanol extract was administered orally to adult Wistar rats at various dosages (400-1600 mg/kg) and the animals sacrificed and various organs examined at a range of times from 30 min up to 24 h after administration. RESULTS: The studies showed a dose- and time-dependent toxic effect, which was reversible on the kidney and liver while there was no noticeable adverse effect on the morphology of the heart, spleen and brain. CONCLUSION: A 70% ethanol extract of the aerial parts of Tithonia diversifolia, which had previously been shown to reduce parasitemia in mice infected with Plasmodium, displayed kidney and liver toxicity at the lowest dose tested. The use of this plant extract against malaria therefore raises concerns over its safety.


Subject(s)
Antimalarials/toxicity , Asteraceae , Kidney/drug effects , Plant Extracts/toxicity , Animals , Brain/drug effects , Cell Size/drug effects , Female , Heart/drug effects , Kidney/pathology , Leukocyte Count , Liver/drug effects , Male , Nigeria , Organ Size/drug effects , Phytotherapy , Plant Components, Aerial , Rats , Rats, Wistar , Spleen/drug effects
12.
Phytother Res ; 23(5): 719-24, 2009 May.
Article in English | MEDLINE | ID: mdl-19107731

ABSTRACT

Epilobium parviflorum Schreb. (Onagraceae) is used for the treatment of benign prostatic hyperplasia (BPH), but its biological action is not entirely identified. This paper aims to report data on E. parviflorum with respect to its antioxidant and antiinflammatory effects. The aqueous acetone extract of E. parviflorum showed higher antioxidant effect in the DPPH assay than well known antioxidants and inhibited the lipid peroxidation determined by the TBA assay (IC(50) = 2.37 +/- 0.12 mg/mL). In concentrations of 0.2-15.0 microg/mL the extract possessed a protective effect, comparable to catalase (250 IU/mL), against oxidative damage, generated in fibroblast cells. In the COX inhibition assay E. parviflorum decreased the PGE(2) release, so showing inhibition of the COX-enzyme (IC(50) = 1.4 +/- 0.1 microg/mL).


Subject(s)
Anti-Inflammatory Agents/pharmacology , Antioxidants/pharmacology , Epilobium/chemistry , Plant Extracts/pharmacology , Prostatic Hyperplasia/drug therapy , Cells, Cultured , Cyclooxygenase 1/metabolism , Cyclooxygenase 2/metabolism , Dinoprostone/metabolism , Humans , Hydrogen Peroxide/metabolism , Inhibitory Concentration 50 , Lipid Peroxidation/drug effects , Male , Oxidative Stress/drug effects
13.
J Ethnopharmacol ; 119(3): 507-12, 2008 Oct 28.
Article in English | MEDLINE | ID: mdl-18573327

ABSTRACT

OBJECTIVE: To investigate the stem bark of Sideroxylon inerme L. and its compounds for tyrosinase-inhibition activity and to evaluate the mechanism involved of the most potent compounds in tyrosinase inhibition. MATERIALS AND METHODS: Three different extracts (acetone, methanol and dichloromethane) of Sideroxylon inerme L. were evaluated for their inhibitory effect in vitro on the monophenolase and diphenolase activated forms of tyrosinase, using a colorimetric procedure. This test was used for bioactivity-guided isolation of two active compounds using column chromatography and TLC. Active extracts were also investigated for their inhibitory effect on melanogenesis in cultured B16 melanoma cells. Antioxidant activities of the methanolic extract of Sideroxylon inerme and purified compounds were investigated using the 1,2-diphenyl-2-picrylhydrazyl (DPPH) antioxidant assay. The inhibition of tyrosinase activity relative to the inhibition of its activity at the transcriptional level was also studied by determination of the degree of expression of mRNAs for this gene by using extract of Sideroxylon inerme-treated cells (B16F10) and semi-quantitative RT-PCR. RESULTS: Methanolic and acetonic extracts of the stem bark of Sideroxylon inerme showed significant inhibition of monophenolase activity (IC50 values of 63 microg/ml and 82 microg/ml, respectively). The methanolic extract also exhibited 37% reduction of melanin content at 6.2 microg/ml in melanocytes without being significantly toxic to the cells. Examination for inhibition of monophenoloxidase in situ on TLC, followed by column chromatographic purification of the stem bark extract of Sideroxylon inerme, resulted in the isolation of two active compounds, epigallocatechin gallate and procyanidin B1, with IC50 values against monophenolase of 30 microg/ml and > 200 microg/ml, respectively. Epigallocatechin gallate exhibited a greater anti-tyrosinase activity than arbutin. Sideroxylon inerme bark extracts, epigallocatechin gallate and procyanidin B1 exhibited antioxidant DPPH radical scavenging activities with EC50 values of 1.54 microg/ml, 1.33 microg/ml and 1.68 microg/ml, respectively and were not particularly cytotoxic. During mechanism studies it was evident that at the transcription level, Sideroxylon inerme (25 microg/ml) was acting as a potent tyrosinase inhibitor compared to controls (untreated cells and kojic acid). CONCLUSION: The bark extract of Sideroxylon inerme and the two isolated compounds warrant further investigation in clinical studies to be considered as skin-depigmenting agents.


Subject(s)
Enzyme Inhibitors/pharmacology , Monophenol Monooxygenase/antagonists & inhibitors , Sapotaceae/chemistry , Skin Pigmentation/drug effects , Animals , Antioxidants/pharmacology , Biphenyl Compounds , Cell Survival/drug effects , Colorimetry , DNA Primers , Indicators and Reagents , Melanins/metabolism , Melanocytes/drug effects , Melanocytes/metabolism , Mice , Picrates , Plant Bark/chemistry , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plant Stems/chemistry , Pyrones/chemistry , Pyrones/pharmacology , RNA/biosynthesis , RNA/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction , South Africa
14.
Cancer Gene Ther ; 15(3): 183-92, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18188187

ABSTRACT

CPT-11 is a potent antitumor agent that is activated by carboxylesterases (CE) and intracellular expression of CEs that can activate the drug results in increased cytotoxicity to the drug. As activation of CPT-11 (irinotecan-7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin) by human CEs is relatively inefficient, we have developed enzyme/prodrug therapy approaches based on the CE/CPT-11 combination using a rabbit liver CE (rCE). However, the in vivo application of this technology may be hampered by the development of an immune response to rCE. Therefore, we have developed a mutant human CE (hCE1m6), based on the human liver CE hCE1, that can activate CPT-11 approximately 70-fold more efficiently than the wild-type protein and can be expressed at high levels in mammalian cells. Indeed, adenoviral-mediated delivery of hCE1m6 with human tumor cells resulted in up to a 670-fold reduction in the IC(50) value for CPT-11, as compared to cells transduced with vector control virus. Furthermore, xenograft studies with human tumors expressing hCE1m6 confirm the ability of this enzyme to activate CPT-11 in vivo and induce antitumor activity. We propose that this enzyme should likely be less immunogenic than rCE and would be suitable for the in vivo application of CE/CPT-11 enzyme/prodrug therapy.


Subject(s)
Camptothecin/analogs & derivatives , Carboxylesterase/genetics , Prodrugs/therapeutic use , Xenograft Model Antitumor Assays , Adenoviridae/genetics , Amino Acid Sequence , Animals , Antineoplastic Agents, Phytogenic/metabolism , Antineoplastic Agents, Phytogenic/therapeutic use , Blotting, Western , COS Cells , Camptothecin/metabolism , Camptothecin/therapeutic use , Carboxylesterase/chemistry , Carboxylesterase/metabolism , Cell Proliferation/drug effects , Chlorocebus aethiops , Combined Modality Therapy , Crystallography, X-Ray , Genetic Therapy/methods , Humans , Irinotecan , Mice , Mice, SCID , Molecular Sequence Data , Mutagenesis, Site-Directed , Mutation , Prodrugs/metabolism , Protein Structure, Secondary , Protein Structure, Tertiary , Sequence Homology, Amino Acid , Transfection
15.
Oncogene ; 27(5): 694-9, 2008 Jan 24.
Article in English | MEDLINE | ID: mdl-17724478

ABSTRACT

We have previously described the identification of a nucleoside analog transcriptional inhibitor ARC (4-amino-6-hydrazino-7-beta-D-ribofuranosyl-7H-pyrrolo[2,3-d]-pyrimidine-5-carboxamide) that was able to induce apoptosis in cancer cell lines of different origin. Here, we report the characterization of ARC on a panel of neuroblastoma cell lines. We found that these cell lines were more than 10-fold sensitive to ARC than to the well-known nucleoside analog DRB (5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole), and that ARC-induced apoptosis proceeds through mitochondrial injury. Also, we observed that ARC-mediated cell death was accompanied by caspase-3 cleavage and repression of antiapoptotic proteins such as Mcl-1 and survivin. Conversely, we found that overexpression of Mcl-1-protected neuroblastoma cell line NB-1691 from ARC-induced apoptosis. Furthermore, we found that while ARC inhibited the phosphorylation of Akt Ser-473 in multiple cancer cell lines, forced expression of myristoylated Akt promoted resistance to ARC-induced apoptosis in neuroblastoma cells. In addition, we observed that ARC was able to downregulate the protein levels of N-myc, a commonly amplified oncogene in neuroblastomas, and Akt protected N-myc from ARC-induced downregulation. These data suggest that ARC may antagonize different antiapoptotic pathways and induce apoptosis in neuroblastoma cells via multiple mechanisms. Overall, ARC could represent an attractive candidate for anticancer drug development against neuroblastomas.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Neuroblastoma/pathology , Nucleosides/pharmacology , Proto-Oncogene Proteins c-akt/drug effects , Proto-Oncogene Proteins c-myc/drug effects , Pyrimidines/pharmacology , Caspase 3/metabolism , Humans , Inhibitor of Apoptosis Proteins , Microtubule-Associated Proteins/metabolism , Mitochondria/drug effects , Myeloid Cell Leukemia Sequence 1 Protein , Neoplasm Proteins/metabolism , Phosphorylation , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Proto-Oncogene Proteins c-myc/metabolism , Survivin , Tumor Cells, Cultured
16.
Phytother Res ; 22(2): 254-5, 2008 Feb.
Article in English | MEDLINE | ID: mdl-17705142

ABSTRACT

Cassia siamea L. (Fabaceae) was identified from the southwest Nigerian ethnobotany as a remedy for febrile illness. This led to the bioassay-guided fractionation of stem bark of the plant extract, using the parasite lactate dehydrogenase assay and multi-resistant strain of Plasmodium falciparum (K1) for assessing the in vitro antimalarial activity. Emodin and lupeol were isolated from the ethyl acetate fraction by a combination of chromatographic techniques. The structures of the compounds were determined by spectroscopy, co-spotting with authentic samples and comparison with literature data. Both compounds were found to be the active principles responsible for the antiplasmodial property with IC(50) values of 5 microg/mL, respectively.


Subject(s)
Antimalarials/pharmacology , Cassia/chemistry , Plant Bark/chemistry , Plant Extracts/pharmacology , Plasmodium falciparum/drug effects , Animals , Antimalarials/chemistry , Emodin/chemistry , Emodin/pharmacology , Parasitic Sensitivity Tests , Pentacyclic Triterpenes , Plant Extracts/chemistry , Triterpenes/chemistry , Triterpenes/pharmacology
17.
Environ Microbiol ; 9(7): 1772-9, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17564610

ABSTRACT

Campylobacter lari is a rare human pathogen most commonly associated with birds and shellfish. Little information has been published regarding its prevalence in other environments, or on its potential role as a reservoir of antibiotic resistance. In this study, we characterized 109 C. lari isolated from a range of hosts using pulsed-field gel electrophoresis of macro-restricted chromosomal DNA, and by determining their susceptibility to a panel of four antibiotics. Pulsed-field gel electrophoresis analysis showed C. lari to be genetically diverse, particularly in isolates from wild birds and environmental water. The most common composite macro-restriction profile (cMRP) was found in multiple hosts (cattle, badgers, wild birds and rabbits), and seven other cMRPs were recovered from more than one host. All isolates were resistant to nalidixic acid and ciprofloxacin. Resistance to erythromycin and ampicillin was uncommon, but was observed in isolates from wild birds, cattle, wild mammals and water samples. The presence of the same cMRP in multiple hosts provides further evidence of transmission between livestock, wildlife and the environment, or for a common source of infection.


Subject(s)
Animals, Wild/microbiology , Campylobacter lari/genetics , Cattle/microbiology , Drug Resistance, Bacterial/genetics , Genetic Variation , Water Microbiology , Animals , Anti-Bacterial Agents/toxicity , Campylobacter lari/drug effects , Cluster Analysis , Dairying , Electrophoresis, Gel, Pulsed-Field , Genotype , Microbial Sensitivity Tests , United Kingdom
18.
Nat Prod Res ; 21(5): 396-400, 2007 May.
Article in English | MEDLINE | ID: mdl-17487609

ABSTRACT

This study reports on the alpha-amylase inhibitory and antimicrobial activities of Senecio leucanthemifolius Poiret. Extracts of S. leucanthemifolius were tested for their antimicrobial and antifungal activities against seven different pathogenic microorganisms using the microdilution technique. The ethyl acetate extract exhibited a strong antibiotic activity against Staphylococcus aureus with a MIC value of 31.25 microg mL(-1), while the n-hexane extract showed a significant activity against dermatophytic fungi. S. leucanthemifolius extracts were tested also for their potential hypoglycemic activity through the in vitro inhibition of alpha-amylase. The dichloromethane extract inhibited alpha-amylase with a value of 56.6% at 0.05 mg mL(-1) and the n-butanol extract showed a value of 89.2% at 1 mg mL(-1).


Subject(s)
Anti-Bacterial Agents/pharmacology , Antifungal Agents/pharmacology , Hypoglycemic Agents/pharmacology , Plant Extracts/pharmacology , Senecio/chemistry , Anti-Bacterial Agents/chemistry , Antifungal Agents/chemistry , Escherichia coli/drug effects , Hypoglycemic Agents/chemistry , Microbial Sensitivity Tests , Microsporum/drug effects , Plant Extracts/chemistry , Staphylococcus aureus/drug effects , Trichophyton/drug effects
19.
Nat Prod Res ; 21(1): 47-55, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17365689

ABSTRACT

The methanol extract from the stems and fruits of Swinglea glutinosa (Rutaceae) afforded 11 known acridone alkaloids and three N-phenylethyl-benzamide derivatives, glycocitrine-IV, 1,3,5-trihydroxy-4-methoxy-10-methyl-2,8-bis(3-methylbut-2-enyl)acridin-9(10H)-one, 1,3,5- trihydroxy-2,8-bis(3-methylbut-2-enyl)-10-methyl-9-acridone, citbrasine, citrusinine-II, citrusinine-I, 5-dihydroxyacronycine, pyranofoline, 3,4-dihydro-3,5,8-trihydroxy-6-methoxy-2,2,7-trimethyl-2H-pyrano[2,3-a]acridin-12(7H)-one, 2,3-dihydro-4,9-dihydroxy-2-(2-hydroxy-propan-2-yl)-11-methoxy-10-methylfuro[3,2-b]acridin-5(10H)-one, bis-5-hydroxyacronycine, N-(2-{4-[(3,7-dimethylocta-2,6-dien-1-yl)oxy]phenyl}ethyl)benzamide, N-(2-{4-[(3,7-dimethyl-4-acethyl-octa-2,6-dien-1-yl)oxy]phenyl}ethyl)benzamide, and severine acetate. All compounds isolated were examined for their activity against three cancer cell lines: human lung carcinoma (COR-L23), human breast adenocarcinoma (MCF7), human melanoma (C32), and normal human fetal lung cell line, MRC-5. The acridones tested exhibited weak cytotoxicity but the amides showed moderate nonselective cytotoxic activity.


Subject(s)
Acridines/isolation & purification , Acridines/pharmacology , Antineoplastic Agents, Phytogenic/isolation & purification , Antineoplastic Agents, Phytogenic/pharmacology , Benzamides/isolation & purification , Benzamides/pharmacology , Rutaceae/chemistry , Acridines/chemistry , Antineoplastic Agents, Phytogenic/chemistry , Benzamides/chemistry , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans , Inhibitory Concentration 50 , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Optical Rotation , Spectrometry, Gamma , Spectrophotometry, Ultraviolet
20.
J Ethnopharmacol ; 110(3): 391-400, 2007 Apr 04.
Article in English | MEDLINE | ID: mdl-17317057

ABSTRACT

Although in vivo models give a more accurate reflection of the activity of substances used in traditional medicine, their use in many countries is severely restricted due to economic and ethical concerns, and this has resulted in the widespread use of in vitro tests in ethnopharmacological studies. Such tests are very useful where the identity of compounds responsible for the biological activity of an extract is being investigated and where limited supplies of material are available, but it is important to consider a variety of factors before making over-predictive claims of that activity in one particular system explains the traditional use. The use of only one bioassay gives a very incomplete picture of the effect of the extract on the whole system involved. A symptom may be due to a number of disease states and, consequently, a variety of mechanisms may serve as targets for bioassays. In a similar way, it is very unusual for there to be only one target for a particular disease so a variety of test systems must be employed. Examples are given of batteries of test systems used to test plants and other materials with a reputation of being useful in wound-healing, diabetes, cancer and to treat cognitive decline associated with old age. In addition, consideration must be given to factors such as absorption into the body and metabolism of any substances present, either to decrease or increase the effect of the 'actives'.


Subject(s)
Biological Assay/methods , Drug Evaluation, Preclinical/methods , Ethnopharmacology/methods , Plants, Medicinal , Biological Assay/ethics , Ethnopharmacology/economics , Ethnopharmacology/ethics , Medicine, Traditional , Models, Biological , Phytotherapy , Plant Extracts
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