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1.
Microbiol Resour Announc ; 12(6): e0025323, 2023 Jun 20.
Article in English | MEDLINE | ID: mdl-37255446

ABSTRACT

Five subcluster C1 mycobacteriophages, Blackbrain, Cactojaque, Kboogie, Trinitium, and YoungMoneyMata, were isolated from soil using the host Mycobacterium smegmatis mc2155. The genome sizes range from 154,512 to 156,223 bp. The largest genome encodes 237 predicted proteins, 34 tRNAs, and 1 transfer-messenger RNA (tmRNA).

2.
Microbiol Resour Announc ; 11(8): e0028622, 2022 Aug 18.
Article in English | MEDLINE | ID: mdl-35863046

ABSTRACT

Four lytic mycobacteriophages, namely, SynergyX, Abinghost, Bananafish, and Delton, were isolated from soil in Washington, DC, using the bacterial host Mycobacterium smegmatis mc2155. Analysis of the genomes revealed that they belong to two subclusters of actinobacteriophage cluster B (subclusters B2 and B3) and subcluster D1 of cluster D.

3.
Microbiol Resour Announc ; 10(27): e0030421, 2021 Jul 08.
Article in English | MEDLINE | ID: mdl-34236221

ABSTRACT

Two temperate mycobacteriophages, Dallas and Jonghyun, were isolated from soil in Washington, DC, using the bacterial host Mycobacterium smegmatis mc2155. Analysis of the genomes revealed that Dallas and Jonghyun belong to clusters J and G, respectively. The structures of the genomes are typical of their respective clusters.

4.
Front Mol Biosci ; 4: 76, 2017.
Article in English | MEDLINE | ID: mdl-29250526

ABSTRACT

We previously reported that the pseudophosphatase MK-STYX (mitogen activated kinase phosphoserine/threonine/tyrosine binding protein) dramatically increases the number of what appeared to be primary neurites in rat pheochromocytoma (PC-12) cells; however, the question remained whether these MK-STYX-induced outgrowths were bona fide neurites, and formed synapses. Here, we report that microtubules and microfilaments, components of the cytoskeleton that are involved in the formation of neurites, are present in MK-STYX-induced outgrowths. In addition, in response to nerve growth factor (NGF), MK-STYX-expressing cells produced more growth cones than non-MK-STYX-expressing cells, further supporting a model in which MK-STYX has a role in actin signaling. Furthermore, immunoblot analysis demonstrates that MK-STYX modulates actin expression. Transmission electron microscopy confirmed that MK-STYX-induced neurites form synapses. To determine whether these MK-STYX-induced neurites have pre-synaptic or post-synaptic properties, we used classical markers for axons and dendrites, Tau-1 and MAP2 (microtubule associated protein 2), respectively. MK-STYX induced neurites were dopaminergic and expression of both Tau-1 and MAP2 suggests that they have both axonal and dendritic properties. Further studies in rat hippocampal primary neurons demonstrated that MK-STYX altered their morphology. A significant number of primary neurons in the presence of MK-STYX had more than the normal number of primary neurites. Our data illustrate the novel findings that MK-STYX induces outgrowths in PC-12 cells that fit the criteria for neurites, have a greater number of growth cones, form synapses, and have pre-synaptic and post-synaptic properties. It also highlights that the pseudophosphatase MK-STYX significantly alters the morphology of primary neurons.

5.
Genome Announc ; 4(6)2016 Nov 23.
Article in English | MEDLINE | ID: mdl-27881532

ABSTRACT

ErnieJ, a cluster C mycobacteriophage that infects Mycobacterium smegmatis mc2155, was recovered from soil in Washington, DC. Its genome is 153,243 bp in size and encodes 227 predicted proteins, 30 tRNAs, and one transfer-messenger RNA (tmRNA). Ten percent of the predicted proteins have homologs in phages that infect nonmycobacterial Actinobacteria.

6.
Infect Dis (Auckl) ; 9: 21-32, 2016.
Article in English | MEDLINE | ID: mdl-27013886

ABSTRACT

Highly active antiretroviral (ARV) therapy (HAART) for chronic suppression of HIV replication has revolutionized the treatment of HIV/AIDS. HAART is no panacea; treatments must be maintained for life. Although great progress has been made in ARV therapy, HIV continues to replicate in anatomical and intracellular sites where ARV drugs have restricted access. Nanotechnology has been considered a platform to circumvent some of the challenges in HIV/AIDS treatment. Dispersion polymerization was used to fabricate two types (PMM and ECA) of polymeric nanoparticles, and each was successfully loaded with four ARV drugs (zidovudine, lamivudine, nevirapine, and raltegravir), followed by physicochemical characterization: scanning electron microscope, particle size, zeta potential, drug loading, and in vitro availability. These nanoparticles efficiently inhibited HIV-1 infection in CEM T cells and peripheral blood mononuclear cells; they hold promise for the treatment of HIV/AIDS. The ARV-loaded nanoparticles with polyethylene glycol on the corona may facilitate tethering ligands for targeting specific receptors expressed on the cells of HIV reservoirs.

8.
PLoS One ; 10(11): e0142328, 2015.
Article in English | MEDLINE | ID: mdl-26555697

ABSTRACT

Plasmodium falciparum infection can cause microvascular dysfunction, cerebral encephalopathy and death if untreated. We have previously shown that high concentrations of free heme, and C-X-C motif chemokine 10 (CXCL10) in sera of malaria patients induce apoptosis in microvascular endothelial and neuronal cells contributing to vascular dysfunction, blood-brain barrier (BBB) damage and mortality. Endothelial progenitor cells (EPC) are microvascular endothelial cell precursors partly responsible for repair and regeneration of damaged BBB endothelium. Studies have shown that EPC's are depleted in severe malaria patients, but the mechanisms mediating this phenomenon are unknown. Toll-like receptors recognize a wide variety of pathogen-associated molecular patterns generated by pathogens such as bacteria and parasites. We tested the hypothesis that EPC depletion during malaria pathogenesis is a function of heme-induced apoptosis mediated by CXCL10 induction and toll-like receptor (TLR) activation. Heme and CXCL10 concentrations in plasma obtained from malaria patients were elevated compared with non-malaria subjects. EPC numbers were significantly decreased in malaria patients (P < 0.02) and TLR4 expression was significantly elevated in vivo. These findings were confirmed in EPC precursors in vitro; where it was determined that heme-induced apoptosis and CXCL10 expression was TLR4-mediated. We conclude that increased serum heme mediates depletion of EPC during malaria pathogenesis.


Subject(s)
Antigens, CD34/immunology , Chemokine CXCL10/biosynthesis , Heme/physiology , Malaria, Falciparum/blood , Stem Cells/immunology , Toll-Like Receptor 4/physiology , Adolescent , Case-Control Studies , Cell Line , Chemokine CXCL10/blood , Child , Child, Preschool , Female , Humans , Malaria, Falciparum/immunology , Male , Toll-Like Receptor 4/blood
9.
Mater Sci Eng C Mater Biol Appl ; 56: 84-7, 2015 Nov 01.
Article in English | MEDLINE | ID: mdl-26249568

ABSTRACT

The chemical and physical characteristics of nanocrystalline hydroxyapatite particles which formed during the subcutaneous implantation of crab shell in Sprague-Dawley rats were studied using selected area electron diffraction (SAED) and high resolution transmission electron microscopy (HRTEM). The initial SAED characterization evidence indicated the presence of an amorphous calcium phosphate phase. The electron dense nanophase particles which formed in the wound healing zone displayed broad diffuse rings which usually indicate a low crystalline order or amorphous phase. High resolution transmission electron microscopy (HRTEM) revealed that these mineralized regions contained discrete single crystal particles less than 5nm in size. Micrographs taken at successively higher magnifications revealed very small nanoparticles with a hexagonal arrangement of ion channels with characteristic spacing of 0.54nm and 0.23nm. This study revealed that single crystal hydroxyapatite nanoparticles consisting of only a few unit cells formed via a biomineralization directed process.


Subject(s)
Bone Substitutes/chemistry , Calcification, Physiologic/drug effects , Durapatite/chemistry , Nanoparticles/chemistry , Animals , Calcium Phosphates/chemistry , Crystallization/methods , Microscopy, Electron, Transmission/methods , Particle Size , Prostheses and Implants , Rats , Rats, Sprague-Dawley , Wound Healing/drug effects
10.
World J Microbiol Biotechnol ; 28(9): 2791-800, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22806719

ABSTRACT

(R)-3-Hydroxycarboxylic acids, chiral enantiomers of bacterial polyhydroxyalkanoates (PHA), may be valuable synthons for the production of numerous industrial materials such as ß-lactams, fungicides, flavors, pheromones and vitamins. In this study, (R)-3-hydroxycarboxylic acid [(R)-3HAs)] synthons were produced by Streptomyces sp. JM3 (JN166713) under batch fermentation. Initial confirmation of PHA production was achieved by matrix assisted laser desorption ionization-time of flight mass spectroscopy and gas chromatography/mass spectroscopy (GC/MS). Subsequently, (R)-3HAs were produced by in vivo depolymerization and the monomers were separated using acid precipitation and anion exchange chromatography. The (R)-3HAs were identified by GC/MS as 3-trimethylsiloxy esters of decanoic, octanoic and butanoic acids. This was further supported by (13)C nuclear magnetic resonance spectrometry. The (R)-3HAs exhibited antimicrobial activity against Escherichia coli O157:H7, Listeria monocytogenes (ATCC 7644) and Salmonella typhimurium (ATCC 14028) with minimum inhibitory concentration ranging from 12.5 to 25 mg ml(-1). However, the minimum bactericidal concentration data suggest that the (R)-3HAs may be bactericidal for E. coli O157:H7 and bacteriostatic for S. typhimurium and L. monocytogenes. Furthermore, the major purified synthon was shown to minimize the invasion of fibroblasts by S. typhimurium (ATCC 14028) [p < 0.05], using the MTT assay [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)].


Subject(s)
Anti-Infective Agents/analysis , Anti-Infective Agents/pharmacology , Polyhydroxyalkanoates/biosynthesis , Streptomyces/chemistry , 3T3 Cells , Animals , Colony Count, Microbial , Escherichia coli O157/drug effects , Fermentation , Fibroblasts/microbiology , Food Microbiology , Food Preservation/methods , Gas Chromatography-Mass Spectrometry , Listeria monocytogenes/drug effects , Mice , Microbial Sensitivity Tests , Polyhydroxyalkanoates/pharmacology , Salmonella typhimurium/drug effects
11.
Am J Trop Med Hyg ; 86(6): 936-42, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22665597

ABSTRACT

Pregnancy in sickle cell disease (SCD) patients is associated with increased risk of maternal and fetal mortality. This study determines pregnancy outcomes among women with SCD delivering at Korle-Bu Teaching Hospital, Accra, Ghana. Nine hundred sixty (960) medical records of pregnant women (131 HbSS, 112 HbSC, and 717 comparison group) from 2007 to 2008 were reviewed. The HbSS women were at increased risk of eclampsia (adjusted odds ratio [AOR] = 10.56, 95% confidence interval [CI] = 3.60-30.96, P < 0.001), intrauterine growth restriction (AOR = 4.00, 95% CI = 1.38-11.64, P = 0.011), and placenta previa (AOR = 22.03, 95% CI = 9.87-49.14, P < 0.001) compared with the comparison group. The HbSC women had increased risk for intrauterine fetal death (AOR = 3.38, 95% CI = 1.15-9.96, P = 0.027) and decreased risk of delivering low birth weight babies (AOR = 0.21, 95% CI = 0.06-0.73, P = 0.014). Women with SCD in Ghana are at a greater risk of morbidity and mortality in pregnancy compared with women without hemoglobinopathies. Improved maternal and fetal outcomes in Ghanaian women with SCD can be achieved through effective intervention by health care providers with thorough knowledge about predisposing factors toward adverse outcomes.


Subject(s)
Anemia, Sickle Cell/epidemiology , Fetal Growth Retardation/epidemiology , Placenta Previa/epidemiology , Pregnancy Complications, Hematologic/epidemiology , Pregnancy Outcome , Adolescent , Adult , Anemia, Sickle Cell/blood , Anemia, Sickle Cell/therapy , Birth Weight , Eclampsia , Female , Fetal Death/blood , Fetal Growth Retardation/blood , Gestational Age , Ghana/epidemiology , Hospitals, Teaching , Humans , Logistic Models , Maternal Mortality , Multivariate Analysis , Placenta Previa/blood , Pregnancy , Pregnancy Complications, Hematologic/blood , Retrospective Studies , Risk Factors , Young Adult
13.
Am J Trop Med Hyg ; 85(1): 12-21, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21734118

ABSTRACT

The effectiveness of intermittent preventive treatment during pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) against malaria and anemia is unclear because of the spread of SP-resistant Plasmodium falciparum. This study evaluates the effectiveness of IPTp-SP among pregnant women attending the antenatal clinic at Korle-Bu Teaching Hospital in Accra, Ghana. A cross-sectional study comparing malaria and anemia prevalence among pregnant women using IPTp-SP with non-IPTp-SP users was conducted during June-August 2009. A total of 363 pregnant women (202 of IPTp users and 161 non-IPTp users) were recruited. A total of 15.3% of IPTp users had malaria compared with 44.7% of non-IPTp users (P < 0.001). A total of 58.4% of non-IPTp users were anemic compared with 22.8% of IPTp users (P < 0.001). When we controlled for other variables, the difference in the prevalence of malaria (odds ratio = 0.18, 95% confidence interval = 0.08-0.37) and anemia (odds ratio = 0.20, 95% confidence interval = 0.12-0.34) remained significant. The recommended IPTp-SP regimen is useful in preventing malaria and anemia among pregnant women in Ghana.


Subject(s)
Anemia/prevention & control , Antimalarials/therapeutic use , Malaria/prevention & control , Pregnancy Complications, Parasitic/prevention & control , Pyrimethamine/therapeutic use , Sulfadoxine/therapeutic use , Adolescent , Adult , Anemia/complications , Drug Combinations , Female , Humans , Malaria/complications , Pregnancy , Surveys and Questionnaires , Young Adult
14.
Article in English | MEDLINE | ID: mdl-20706538

ABSTRACT

In sub-Saharan Africa, approximately 30 million pregnant women are at risk of contracting malaria annually. Nearly 36% of healthy pregnant women receiving routine antenatal care tested positive for Plasmodium falciparum HRP-II antigen in Ghana. We tested the hypothesis that asymptomatic HRP II positive pregnant women expressed a unique Th1 and Th2 phenotype that differs from healthy controls. Plasma from healthy (n = 15) and asymptomatic (n = 25) pregnant women were evaluated for 27 biomarkers (IL-1b, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-15, IL- 17, Eotaxin, bFGF-2, G-CSF, GM-CSF, IFN-gamma, IP-10, MCP-1, MIP-1alpha, MIP-1beta, PDGF-bb, RANTES, TNF, and VEGF) associated with Th1 and Th2 cytokine homeostasis. IL-10 and G-CSF levels were elevated in the asymptomatic group when compared with the healthy group (P = .031 and .041, resp.). The median ratios of IL-1beta:5, IL-1beta:10, IL-1beta:G-CSF, IL-1beta:Eotaxin, IL-12:G-CSF, IL-15:10, IL-17:G-CSF, IL-17:Eotaxin, TNF:IL-4, TNF:IL-5, and TNF:G-CSF were significantly different among the two groups. Thus, asymptomatic malaria carriage may be linked to circulating levels of IL-10 and G-CSF.


Subject(s)
Granulocyte Colony-Stimulating Factor/blood , Interleukin-10/blood , Malaria, Falciparum/blood , Pregnancy Complications, Infectious/blood , Adult , Biomarkers/analysis , Female , Humans , Malaria, Falciparum/diagnosis , Pregnancy
15.
J Ind Microbiol Biotechnol ; 37(8): 849-56, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20467780

ABSTRACT

Polyhydroxyalkanoates (PHAs) are naturally occurring biodegradable polymers with promising application in the formulation of plastic materials. PHAs are produced by numerous bacteria as energy/carbon storage materials from various substrates, including sugars and plant oils. Since these substrates compete as food sources, their use as raw material for industrial-scale production of PHA is limited. Therefore, efforts have been focused on seeking alternative sources for bacterial production of PHA. One substrate that seems to have great potential is the seed oil of Jatropha curcas plant. Among other favorable properties, J. curcas seed oil is non-edible, widely available, and can be cheaply produced. In this study, Pseudomonas oleovorans (ATCC 29347) was grown in a mineral salt medium supplemented with saponified J. curcas seed oil as the only carbon source under batch fermentation. Optimum PHA yield of 26.06% cell dry weight was achieved after 72 h. The PHA had a melting point (T(m)) between 150 and 160 degrees C. Results of polymer analyses by gas chromatography/mass spectrometry (GC/MS) identified only the methyl 3-hydroxybutanoate monomeric unit. However, electrospray ionization-time of flight mass spectroscopy (ESI-TOF MS) confirmed that the PHA was a copolymer with the characteristic HB/HV peaks at m/z 1155.49 (HB) and 1,169, 1,184-1,194 (HV). The data were further supported by 1H and 13C NMR analysis. Polymer analysis by gel permeation chromatography (GPC) indicated a peak molecular weight (MP) of 179,797, molecular weight (M(W)) of 166,838, weight number average mass (M(n)) of 131,847, and polydispersity (M(w)/M (n)) of 1.3. The data from this study indicate that J. curcas seed oil can be used as a substrate to produce the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3HB-co-3HV).


Subject(s)
Jatropha/chemistry , Oils/metabolism , Polyesters/metabolism , Pseudomonas oleovorans/metabolism , Carbon/metabolism , Chromatography, Gel , Culture Media/chemistry , Fermentation , Gas Chromatography-Mass Spectrometry , Magnetic Resonance Spectroscopy , Molecular Weight , Polyesters/chemistry , Seeds/chemistry , Spectrometry, Mass, Electrospray Ionization , Time Factors , Transition Temperature
16.
Mol Biochem Parasitol ; 162(2): 172-6, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18848585

ABSTRACT

The severity of malaria is multi-factorial. It is associated with parasite-induced alteration in pro-inflammatory and anti-inflammatory cytokine and chemokine levels in host serum and cerebrospinal fluid. It is also associated with sequestration and cytoadherence of parasitized erythrocytes (pRBCs) in post-capillary venules and blood-brain barrier (BBB) dysfunction. The role of these factors in development of vascular injury and tissue damage in malaria patients is unclear. While some studies indicate a requirement for pRBC adhesion to vascular endothelial cells (ECs) in brain capillaries to induce apoptosis and BBB damage, others show no role of apoptosis resulting from adhesion of pRBC to EC. In the present study, the hypothesis that soluble factors from Plasmodium falciparum-infected erythrocytes induce apoptosis in human brain vascular endothelial (HBVEC) and neuroglia cells (cellular components of the BBB) was tested. Apoptotic effects of parasitized (pRBC) and non-parasitized erythrocyte (RBC) conditioned medium on HBVEC and neuroglia cells were determined in vitro by evaluating nuclear DNA fragmentation (TUNEL assay) in cultured cells. Soluble factors from P. falciparum-infected erythrocytes in conditioned medium induced extensive DNA fragmentation in both cell lines, albeit to a greater extent in HBVEC than neuroglia, indicating that extended exposure to high levels of these soluble factors in serum may be associated with vascular, neuronal and tissue injury in malaria patients.


Subject(s)
Apoptosis , Brain/cytology , Endothelium, Vascular/cytology , Erythrocytes/parasitology , Neuroglia/cytology , Plasmodium falciparum/metabolism , Plasmodium falciparum/pathogenicity , Animals , Blood-Brain Barrier/metabolism , Brain/blood supply , Brain/metabolism , Cells, Cultured , Endothelial Cells/metabolism , Endothelial Cells/parasitology , Humans , Neuroglia/metabolism , Neuroglia/parasitology
17.
Am J Trop Med Hyg ; 78(5): 733-5, 2008 May.
Article in English | MEDLINE | ID: mdl-18458305

ABSTRACT

Detection of Plasmodium falciparum parasites in patients with malaria necessitates drawing blood, which increases the risk of accidental infections and is poorly accepted in communities with blood taboos. Thus, non-invasive, cost-effective malaria tests that minimize the need for blood collection are needed. Plasmodium falciparum histidine-rich protein II (PfHRP II) levels in plasma and saliva were compared in malaria-positive and -negative patients in Ghana. Plasma and saliva obtained from 30 thick-film positive and 10 negative children were evaluated for PfHRP II by ELISA. Among the 30 children with positive blood smear, 16 (53%) were PfHRP II positive in plasma and 13 (43%) had PfHRP II positive saliva. The sensitivity of PfHRP II detection was 53% for plasma and 43% for saliva. The specificity was 100% with no false positive for both plasma and saliva when compared with blood smear. Thus, rapid detection of PfHRP II antigen in saliva may be a useful non-invasive and cost-effective malaria diagnostic technique.


Subject(s)
Antigens, Protozoan/analysis , Malaria, Falciparum/diagnosis , Protozoan Proteins/analysis , Saliva/parasitology , Adolescent , Animals , Antigens, Protozoan/blood , Child , Child, Preschool , Female , Humans , Male , Protozoan Proteins/blood , Reference Values , Sensitivity and Specificity , Specimen Handling/methods
18.
Malar J ; 6: 147, 2007 Nov 12.
Article in English | MEDLINE | ID: mdl-17997848

ABSTRACT

BACKGROUND: Plasmodium falciparum can cause a diffuse encephalopathy known as cerebral malaria (CM), a major contributor to malaria associated mortality. Despite treatment, mortality due to CM can be as high as 30% while 10% of survivors of the disease may experience short- and long-term neurological complications. The pathogenesis of CM and other forms of severe malaria is multi-factorial and appear to involve cytokine and chemokine homeostasis, inflammation and vascular injury/repair. Identification of prognostic markers that can predict CM severity will enable development of better intervention. METHODS: Postmortem serum and cerebrospinal fluid (CSF) samples were obtained within 2-4 hours of death in Ghanaian children dying of CM, severe malarial anemia (SMA), and non-malarial (NM) causes. Serum and CSF levels of 36 different biomarkers (IL-1beta, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12 (p70), IL-13, IL-15, IL-17, Eotaxin, FGF basic protein, CRP, G-CSF, GM-CSF, IFN-gamma, TNF-alpha, IP-10, MCP-1 (MCAF), MIP-1alpha, MIP-1beta, RANTES, SDF-1alpha, CXCL11 (I-TAC), Fas-ligand [Fas-L], soluble Fas [sFas], sTNF-R1 (p55), sTNF-R2 (p75), MMP-9, TGF-beta1, PDGF bb and VEGF) were measured and the results compared between the 3 groups. RESULTS: After Bonferroni adjustment for other biomarkers, IP-10 was the only serum biomarker independently associated with CM mortality when compared to SMA and NM deaths. Eight CSF biomarkers (IL-1ra, IL-8, IP-10, PDGFbb, MIP-1beta, Fas-L, sTNF-R1, and sTNF-R2) were significantly elevated in CM mortality group when compared to SMA and NM deaths. Additionally, CSF IP-10/PDGFbb median ratio was statistically significantly higher in the CM group compared to SMA and NM groups. CONCLUSION: The parasite-induced local cerebral dysregulation in the production of IP-10, 1L-8, MIP-1beta, PDGFbb, IL-1ra, Fas-L, sTNF-R1, and sTNF-R2 may be involved in CM neuropathology, and their immunoassay may have potential utility in predicting mortality in CM.


Subject(s)
Biomarkers/blood , Biomarkers/cerebrospinal fluid , Malaria, Cerebral/blood , Malaria, Cerebral/cerebrospinal fluid , Chemokine CCL5/blood , Chemokine CCL5/cerebrospinal fluid , Chemokine CXCL10/blood , Chemokine CXCL10/cerebrospinal fluid , Chemokines, CC/blood , Chemokines, CC/cerebrospinal fluid , Child , Child, Preschool , E-Selectin/blood , E-Selectin/cerebrospinal fluid , Enzyme-Linked Immunosorbent Assay , Fas Ligand Protein/blood , Fas Ligand Protein/cerebrospinal fluid , Female , Ghana , Humans , Immunoassay , Infant , Interleukin 1 Receptor Antagonist Protein/blood , Interleukin 1 Receptor Antagonist Protein/cerebrospinal fluid , Interleukin-8/blood , Interleukin-8/cerebrospinal fluid , Malaria, Cerebral/mortality , Male , Prognosis , Survival Rate , Tumor Necrosis Factor-alpha/blood , Tumor Necrosis Factor-alpha/cerebrospinal fluid
19.
Leuk Res ; 29(8): 863-79, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15978937

ABSTRACT

Human monocytic THP-1 cells can be induced to differentiate to macrophages when treated with phorbol 12-myristate 13-acetate (PMA). It is understood that before initiating cell differentiation, PMA treatment must first induce an inhibition of cell growth. Since the initial biochemical and molecular events that are associated with this growth inhibition have not been characterized, the present study was carried out to elucidate the molecular mechanisms associated with the PMA-induced growth arrest of THP-1 cells. Our results indicate that PMA inhibits THP-1 cells at G1-phase of the cell cycle, via a complex mechanism associated with the modulation of the expression of several cell cycle regulators, initiated by the cellular generation of reactive oxygen species (ROS). Both p21WAF1/CIP1 mRNA and protein were upregulated 24 h post PMA treatment as demonstrated by ribonuclease protection assay and Western blotting, respectively. Because these cells lack functional p53, this effect was independent of p53 activity. Electrophoretic mobility shift assay showed that the PMA-induced activation of the p21WAF1/CIP1 promoter was driven by the specific protein 1 (Sp1) transcription factor through Sp1-binding sites. Additionally, our study demonstrates that PMA-induces the upregulation of p21 through a protein kinase C (PKC)-mediated ROS-dependent signaling mechanism involving MAP kinase activation.


Subject(s)
Cell Proliferation/drug effects , Gene Expression Regulation, Leukemic/drug effects , Monocytes/drug effects , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Tetradecanoylphorbol Acetate/analogs & derivatives , Tetradecanoylphorbol Acetate/pharmacology , Antioxidants/pharmacology , CDC2-CDC28 Kinases/antagonists & inhibitors , Cell Cycle/drug effects , Cell Cycle Proteins/drug effects , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Cyclin-Dependent Kinase 2 , Cyclin-Dependent Kinase Inhibitor p21 , Extracellular Signal-Regulated MAP Kinases/metabolism , Flavonoids/pharmacology , G1 Phase/drug effects , Humans , Phosphorylation , Protein Kinase C/metabolism , RNA, Messenger/drug effects , Retinoblastoma Protein/drug effects , Retinoblastoma Protein/metabolism , S Phase/drug effects , Tetradecanoylphorbol Acetate/antagonists & inhibitors , Time Factors
20.
Respir Physiol ; 129(3): 289-96, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11788132

ABSTRACT

Following exposure of anesthetized and unanesthetized rats to hypercapnic stress, arginine vasopressin (AVP)-containing neurons of the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei were examined for expression of the c-fos gene encoded protein (c-Fos). In addition, we determined whether AVP-containing PVN neurons activated by hypercapnia project to phrenic nuclei. In adult control rats, only scant c-Fos-like immunoreactive neurons were observed within the hypothalamic nuclei. A marked increase in c-Fos positive cells was induced after 2 h of breathing a gas mixture with elevated CO(2) (5% CO(2), 21% O(2) and 74% N(2), or 1 h following breathing of 12% CO(2,) 21% O(2,) and 67% N(2)). Colocalization studies of AVP and c-Fos protein revealed that in the PVN, 75% of AVP-containing cells expressed c-Fos immunoreactivity. c-Fos and AVP were coexpressed in 60% of SON neurons in anesthetized rats. In addition, retrograde labeling studies with cholera toxin b subunit (CTb) revealed that a subpopulation of PVN cells (15%) that project to phrenic nuclei are activated by hypercapnia, as indicated by c-Fos expression. These results indicate that (i) PVN and SON AVP-containing neurons are part of the neuronal networks that react to hypercapnic exposure; and (ii) a subset of CO(2) reactive PVN cells innervate phrenic nuclei.


Subject(s)
Arginine Vasopressin/metabolism , Hypercapnia/metabolism , Neurons/metabolism , Paraventricular Hypothalamic Nucleus/metabolism , Proto-Oncogene Proteins c-fos/metabolism , Supraoptic Nucleus/metabolism , Animals , Hypercapnia/physiopathology , Male , Neurons/physiology , Paraventricular Hypothalamic Nucleus/physiopathology , Phrenic Nerve/physiopathology , Rats , Rats, Sprague-Dawley , Supraoptic Nucleus/pathology , Synaptic Transmission/physiology
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