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1.
Eur J Paediatr Dent ; 19(3): 221-225, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30063155

ABSTRACT

AIM: To assess the immediate effect of a 60-minute oral health educational seminar for paediatric and family medicine residents in improving their knowledge, attitude, likelihoodtowards incorporating oral health preventive practice in their current practices to well-child visits, and confidence in identifying and referring patients with dental trauma. MATERIALS AND METHODS: Baseline pre- and post-test design was used to evaluate the immediate effect of a 60-minute PowerPoint oral health educational seminar given to the paediatric and family medicine residents. STATISTICS: Multiple-choice items were used and the pre- and post-test data were analysed with McNemar and Wilcoxon signed-rank tests. A p-value <0.05 was considered statistically significant. RESULTS: Sixty-eight residents participated in the oral health educational seminar and completed the questionnaire. The mean age of participants was 29.9 years old (SD ±4.8 yrs.). Immediately following a 60-minute oral health educational seminar, there was an overall significant increase in participants' knowledge, attitudes and likelihood towards incorporating oral health preventive practice in their current practices to well-child visits (p<0.05). More confidence in identifying and referring patients with dental trauma was reported by 100% of participants. CONCLUSIONS: A 60-minute oral health educational seminar was effective in improving paediatric and family medicine residents' immediate knowledge, attitude, and likelihood towards incorporating oral health preventive practice in their current practices to well-child visits. Significantly more residents felt more confident in identifying and referring patients with dental trauma. Key messages: an oral health educational seminar can be effective in improving paediatric and family medicine residents' immediate knowledge, attitude, and likelihood towards incorporating oral health preventive practice in their current practices to well-child visits.


Subject(s)
Education, Dental/organization & administration , Family Practice/education , Health Knowledge, Attitudes, Practice , Pediatrics/education , Adult , Female , Humans , Internship and Residency , Male
2.
J Appl Microbiol ; 125(4): 976-985, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29856506

ABSTRACT

AIMS: The objectives of this work were to characterize molecularly the morphologically described endophyte Balansia epichloe symbiotic on three grass species, and to determine the in situ production of ergot alkaloids on these three symbiota. METHODS AND RESULTS: Balansia epichloe symbiotic with smut grass (Sporobolus poiretii), love grass (Eragrostis hirsuta) and lace grass (Eragrostis capillaries, a new host) were characterized using DNA barcoding. Laser ablation electro spray ionization (LAESI)-mass spectrometry was used to detect ergot alkaloids in situ for each symbiotum. CONCLUSIONS: The three morphologically described symbionts on the three host grasses were indicated as belonging to the species B. epichloe, DNA barcoding suggested they were related although a cryptic species was suggested. LAESI-mass spectrometry showed that ergot alkaloids were produced in vivo in two hosts but not the third although this same symbiotum was related to one of the ergot alkaloid producing symbiota as revealed by the DNA-barcoding procedure. SIGNIFICANCE AND IMPACT OF THE STUDY: These results established the accumulation of ergot alkaloids in pot culture by a morpho species although there were variations with each species of grass. Barcoding described divergence among species, but considering its limitation, the suggested existence of cryptic species among this morphospecies requires substantiation by studies that are more rigorous.


Subject(s)
Endophytes/metabolism , Ergot Alkaloids/chemistry , Hypocreales/metabolism , Poaceae/chemistry , Poaceae/microbiology , Endophytes/chemistry , Endophytes/genetics , Endophytes/isolation & purification , Ergot Alkaloids/metabolism , Hypocreales/chemistry , Hypocreales/genetics , Hypocreales/isolation & purification , Mass Spectrometry , Molecular Structure , Phylogeny , Symbiosis
3.
J Appl Microbiol ; 125(3): 867-875, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29729222

ABSTRACT

AIMS: Biofilms are composed of micro-organisms within a matrix of chemically complex polymer compounds and from these structures many unknown competitive factors are suggested that many considered are important consequences for biological control. This research was undertaken to study further the endophyte, Bacillus mojavensis and its relationships to biofilm and two classes of lipopeptides considered relevant for biocontrol of plant pathogens. METHODS AND RESULTS: Laser ablation electrospray ionization mass spectrometry and conventional MS/MS were used to study in situ biofilm production and the production of lipopeptides fengycin and surfactin in different strains of B. mojavensis in plate and test tube culture on two media. All strains were capable of producing biofilm in vitro along with the accumulation of surfactin and fengycin although no concentration-dependent relationship between lipopeptide accumulation and biofilm was observed. CONCLUSION: All strains studied produce biofilms in culture with the accumulated surfactin and fengycin, demonstrating that endophytic bacteria also produced biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates that this endophytic species produced biofilms along with two biocontrol compounds of which one, surfactin, considered by others as a quorum sensor, highlighting its ecological role as a signalling mechanism in planta.


Subject(s)
Bacillus/chemistry , Biofilms , Lipopeptides , Peptides, Cyclic , Spectrometry, Mass, Electrospray Ionization/methods , Lipopeptides/analysis , Lipopeptides/chemistry , Peptides, Cyclic/analysis , Peptides, Cyclic/chemistry
4.
Transl Psychiatry ; 7(4): e1095, 2017 04 18.
Article in English | MEDLINE | ID: mdl-28418405

ABSTRACT

Dampened adenosine A2A receptor (A2AR) function has been implicated in addiction through enhancement of goal-directed behaviors. However, the contribution of the A2AR to the control of impulsive reward seeking remains unknown. Using mice that were exposed to differential reward of low rate (DRL) schedules during Pavlovian-conditioning, second-order schedule discrimination, and the 5-choice serial reaction time task (5-CSRTT), we demonstrate that deficits of A2AR function promote impulsive responses. Antagonism of the A2AR lowered ERK1 and ERK2 phosphorylation in the dorsal hippocampus (dHip) and potentiated impulsivity during Pavlovian-conditioning and the 5-CSRTT. Remarkably, inhibition of ERK1 and ERK2 phosphorylation by U0126 in the dHip prior to Pavlovian-conditioning exacerbated impulsive reward seeking. Moreover, we found decreased A2AR expression, and reduced ERK1 and ERK2 phosphorylation in the dHip of equilibrative nucleoside transporter type 1 (ENT1-/-) null mice, which displayed exacerbated impulsivity. To determine whether impulsive response behavior is associated with hippocampal neuroblast development, we investigated expression of BrdU+ and doublecortin (DCX+) following 5-CSRTT testing. These studies revealed that impulsive behavior driven by inhibition of the A2AR is accompanied by increased neuroblast proliferation in the hippocampus.


Subject(s)
Cell Proliferation/genetics , Hippocampus/metabolism , Impulsive Behavior/physiology , MAP Kinase Signaling System/genetics , Neurogenesis/genetics , Receptors, Adenosine A2/genetics , Animals , Choice Behavior , Conditioning, Classical , Doublecortin Protein , Mice , Mice, Inbred C57BL , Mice, Inbred Strains , Phosphorylation , Reaction Time , Reward
5.
Cult Med Psychiatry ; 40(3): 383-403, 2016 Sep.
Article in English | MEDLINE | ID: mdl-26487660

ABSTRACT

"Thinking too much", and variations such as "thinking a lot", are common idioms of distress across the world. The contextual meaning of this idiom of distress in particular localities remains largely unknown. This paper reports on a systematic study of the content and cause, consequences, and social response and coping related to the local terms |x'an n|a te and |eu-ca n|a te, both translated as "thinking a lot", and was part of a larger ethnographic study among the Khwe of South Africa. Semi-structured exploratory interviews with community members revealed that "thinking a lot" refers to a common experience of reflecting on personal and interpersonal problems. Consequences were described in emotional, psychological, social, behavioral, and physical effects. Coping strategies included social support, distraction, and religious practices. Our contextualized approach revealed meanings and experiences of "thinking a lot" that go beyond a psychological state or psychopathology. The common experience of "thinking a lot" is situated in socio-political, economic, and social context that reflect the marginalized and displaced position of the Khwe. We argue that "thinking a lot" and associated local meanings may vary across settings, may not necessarily indicate psychopathology, and should be understood in individual, interpersonal, community, and socio-political dimensions.


Subject(s)
Adaptation, Psychological , Interpersonal Relations , Stress, Psychological/ethnology , Thinking , Adult , Aged , Female , Humans , Male , Middle Aged , Qualitative Research , South Africa/ethnology
6.
Transl Psychiatry ; 5: e621, 2015 Aug 18.
Article in English | MEDLINE | ID: mdl-26285131

ABSTRACT

Acamprosate has been widely used since the Food and Drug Administration approved the medication for treatment of alcohol use disorders (AUDs) in 2004. Although the detailed molecular mechanism of acamprosate remains unclear, it has been largely known that acamprosate inhibits glutamate action in the brain. However, AUD is a complex and heterogeneous disorder. Thus, biomarkers are required to prescribe this medication to patients who will have the highest likelihood of responding positively. To identify pharmacometabolomic biomarkers of acamprosate response, we utilized serum samples from 120 alcohol-dependent subjects, including 71 responders (maintained continuous abstinence) and 49 non-responders (any alcohol use) during 12 weeks of acamprosate treatment. Notably, baseline serum glutamate levels were significantly higher in responders compared with non-responders. Importantly, serum glutamate levels of responders are normalized after acamprosate treatment, whereas there was no significant glutamate change in non-responders. Subsequent functional studies in animal models revealed that, in the absence of alcohol, acamprosate activates glutamine synthetase, which synthesizes glutamine from glutamate and ammonia. These results suggest that acamprosate reduces serum glutamate levels for those who have elevated baseline serum glutamate levels among responders. Taken together, our findings demonstrate that elevated baseline serum glutamate levels are a potential biomarker associated with positive acamprosate response, which is an important step towards development of a personalized approach to treatment for AUD.


Subject(s)
Alcohol-Related Disorders/blood , Alcohol-Related Disorders/drug therapy , Glutamic Acid/blood , Taurine/analogs & derivatives , Acamprosate , Alcohol Deterrents/blood , Alcohol Deterrents/therapeutic use , Biomarkers/blood , Humans , Taurine/blood , Taurine/therapeutic use , Treatment Outcome
7.
Ecotoxicology ; 23(5): 929-38, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24723096

ABSTRACT

A major contaminant of concern for mountaintop removal/valley fill (MTR/VF) coal mining is selenium (Se), an essential micronutrient that can be toxic to fish. Creek chubs (Semotilus atromaculatus), green sunfish (Lepomis cyanellus), and composite insect samples were collected in March-July, 2011-2013 at two sites within the Mud River, West Virginia. One site (MR7) receives MTR/VF coal mining effluent, while the reference site (LFMR) does not. MR7 water had significantly higher concentrations of soluble Se (p < 0.01) and conductivity (p < 0.005) compared to LFMR. MR7 whole insects contained significantly higher concentrations of Se compared to LFMR insects (p < 0.001). MR7 creek chubs had significantly higher Se in fillets, liver, and ovary tissues compared to LFMR samples (p < 0.0001, p < 0.0001, and p < 0.02, respectively). MR7 green sunfish fillets contained significantly higher Se (p < 0.0001). Histological examination showed LFMR creek chub gills contained a typical amount of parasitic infestations; however MR7 gills contained minimal to no visible parasites. X-ray absorption spectroscopic analyses revealed that MR7 whole insects and creek chub tissues primarily contained organic Se and selenite. These two species of Mud River fish were shown to specifically accumulate Se differently in tissues compartments. Tissue-specific concentrations of Se may be useful in determining potential reproductive consequences of Se exposure in wild fish populations.


Subject(s)
Cyprinidae/metabolism , Insecta/metabolism , Perciformes/metabolism , Selenium/metabolism , Water Pollutants, Chemical/metabolism , Animals , Coal Mining , Female , Gills/chemistry , Insecta/chemistry , Liver/chemistry , Muscles/chemistry , Ovary/chemistry , Selenium/analysis , Water/analysis , X-Ray Absorption Spectroscopy
8.
J Comp Pathol ; 149(4): 434-45, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23664425

ABSTRACT

Laboratory fish species are used increasingly in biomedical research and are considered robust models for the study of regenerative processes. Studies investigating the response of the fish liver to injury have demonstrated the presence of a ductular reaction and oval-like cells in injured and regenerating liver. To date, however, it is unclear if this cell population is the piscine equivalent of oval cells (OCs) or intermediate hepatobiliary cells (IHBCs) identified in rodents and man, respectively. The present study defines the process of OC differentiation in fish liver using histopathology, immunohistochemistry and transmission electron microscopy. To generate OC proliferation in Japanese medaka (Oryzias latipes), hepatic injury was induced by exposure of adult fish to either microcystin LR or dimethylnitrosamine. A transgenic strain of medaka expressing a red fluorescent protein (RFP) exclusively in hepatocytes was used. The morphological response to injury was characterized by a ductular reaction comprised of cytokeratin (CK) AE1/AE3(+) OCs progressing to IHBCs variably positive for CK and RFP and finally mature RFP(+) hepatocytes and CK(+) cholangiocytes. These observations support a bipotential differentiation pathway of fish OCs towards hepatocytes and cholangiocytes. Ultrastructural morphology confirmed the presence of OCs and differentiation towards hepatocytes. These results demonstrated clear similarities between patterns of reaction to injury in fish and mammalian livers. They also confirm the presence of, and support the putative bipotential lineage capabilities of, the fish OC.


Subject(s)
Hepatocytes/cytology , Liver Regeneration/physiology , Liver/injuries , Stem Cells/cytology , Animals , Animals, Genetically Modified , Cell Differentiation/physiology , Disease Models, Animal , Female , Hepatocytes/ultrastructure , Immunohistochemistry , Male , Microscopy, Electron, Transmission , Oryzias , Stem Cells/ultrastructure
9.
Mar Pollut Bull ; 63(5-12): 86-90, 2011.
Article in English | MEDLINE | ID: mdl-21592532

ABSTRACT

Hepatic lipidosis is a non-specific biomarker of effect from pollution exposure in fish. Fatty liver is often misdiagnosed or overlooked in histological assessments due to the decreasing application of specific fat procedures and stains. For example, ethanol dehydration in standard paraffin processing removes lipids, leaving vacuoles of which the precise nature is unknown. Lipids can be identified using osmium post-fixation in semi-thin resin sections or transmission electron microscopy. However, both are expensive and technically demanding procedures, often not available for routine environmental risk assessment and monitoring programs. The current emphasis to reduce and refine animal toxicity testing, requires refinement of the suite of histopathological techniques currently available to maximize information gained from using fish for toxicity testing and as bio-indicators of environmental quality. This investigation has successfully modified an osmium post-fixation technique to conserve lipids in paraffin-embedded tissues using medaka (Oryzias latipes) eleutheroembryos and eggs (embryos) as lipid rich models.


Subject(s)
Embryo, Nonmammalian/metabolism , Lipid Metabolism , Liver/metabolism , Osmium/chemistry , Ovum/metabolism , Paraffin Embedding/methods , Animals , Embryo, Nonmammalian/pathology , Liver/pathology , Models, Biological , Oryzias
10.
Cell Death Differ ; 17(3): 488-98, 2010 Mar.
Article in English | MEDLINE | ID: mdl-19816510

ABSTRACT

Neurodegenerative diseases are often associated with dysfunction in protein quality control. The endoplasmic reticulum (ER), a key site for protein synthesis, senses stressful conditions by activating the unfolded protein response (UPR). In this study we report the creation of a novel mouse model in which GRP78/BiP, a major ER chaperone and master regulator of UPR, is specifically eliminated in Purkinje cells (PCs). GRP78-depleted PCs activate UPR including the induction of GRP94, PDI, CHOP and GADD34, feedback suppression of eIF2alpha phosphorylation and apoptotic cell death. In contrast to current models of protein misfolding in which an abnormal accumulation of ubiquitinated protein is prominent, cytosolic ubiquitin staining is dramatically reduced in GRP78-null PCs. Ultrastructural evaluation reveals that the ER shows prominent dilatation with focal accumulation of electron-dense material within the ER. The mice show retarded growth and severe motor coordination defect by week 5 and cerebellar atrophy by week 13. Our studies uncover a novel link between GRP78 depletion and reduction in cytosolic ubiquitination and establish a novel mouse model of accelerated cerebellar degeneration with basic and clinical applications.


Subject(s)
Apoptosis/physiology , Heat-Shock Proteins/metabolism , Purkinje Cells/physiology , Unfolded Protein Response , Animals , Behavior, Animal/physiology , Calbindins , Calnexin/metabolism , Cerebellum/cytology , Cerebellum/metabolism , Cerebellum/pathology , Endoplasmic Reticulum Chaperone BiP , Female , Heat-Shock Proteins/genetics , Humans , Male , Mice , Mice, Knockout , Neurodegenerative Diseases/metabolism , Neurodegenerative Diseases/pathology , Purkinje Cells/cytology , S100 Calcium Binding Protein G/metabolism , Signal Transduction/physiology , Ubiquitin/metabolism
11.
Cult Med Psychiatry ; 33(2): 219-65, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19333741

ABSTRACT

This article explores the nightmares of Cambodian refugees in a cultural context, and the role of nightmares in the trauma ontology of this population, including their role in generating post-traumatic stress disorder (PTSD). Among Cambodian refugees attending a psychiatric clinic, we found that having a nightmare was strongly associated with having PTSD (chi(2) = 61.7, P < 0.001, odds ratio = 126); that nightmares caused much distress upon awakening, including panic attacks, fear of bodily dysfunction, flashbacks and difficulty returning to sleep; that nightmare content was frequently related to traumatic events; that nightmares resulted in a decrease in the sense of "concentric ontology security" (i.e., in an increased sense of physical and spiritual vulnerability in a culture that conceives of the self in terms of concentric, protective layers), including fears of being attacked by ghosts; and that nightmares frequently led to the performance of specific practices and rituals aiming to extrude and repel attacking forces and to create "protective layers." Cases are presented to illustrate these findings. The Discussion considers some treatment implications of the study.


Subject(s)
Dreams , Refugees/psychology , Safety , Adult , Cambodia/ethnology , Female , Humans , Interviews as Topic , Male , Massachusetts , Middle Aged , Stress Disorders, Post-Traumatic/ethnology , Stress Disorders, Post-Traumatic/psychology
13.
Arch Environ Contam Toxicol ; 55(4): 659-69, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18704254

ABSTRACT

We examined the sensitivity of the wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting the toxicant into their eggs. Six groups of wood duck eggs (n = 35 to 211 per trial) were injected with 0 to 4600 pg TCDD/g egg between 2003 and 2005. Injections were made into yolk prior to incubation, and eggs were subsequently incubated and assessed weekly for mortality. Significant TCDD-induced mortality was not observed through day 25 (90% of incubation). Liver, heart, eye, and brain histology were generally unremarkable. Hepatic ethoxyresorufin-O-deethylase activity, a biomarker of dioxin-like compound exposure, was induced by 12-fold in the 4600 pg/g treatment relative to controls. The median lethal dose for chicken (Gallus domesticus) eggs we dosed identically to wood duck eggs was about 100 pg/g, similar to other assessments of chickens. Among dioxin-like compound embryo lethality data for 15 avian genera, the wood duck 4600 pg/g no-observed-effect level ranks near the middle. Because no higher doses were tested, wood ducks may be like other waterfowl (order Anseriformes), which are comparatively tolerant to embryo mortality from polychlorinated dibenzo-p-dioxins and dibenzofurans when exposed by egg injection.


Subject(s)
Ducks/physiology , Embryo, Nonmammalian/drug effects , Embryonic Development/drug effects , Environmental Pollutants/toxicity , Polychlorinated Dibenzodioxins/toxicity , Teratogens/toxicity , Abnormalities, Drug-Induced , Animals , Cytochrome P-450 CYP1A1/biosynthesis , Dose-Response Relationship, Drug , Embryo, Nonmammalian/embryology , Enzyme Induction , Immunoenzyme Techniques , Lethal Dose 50 , Liver/drug effects , Liver/enzymology , Microsomes, Liver/drug effects , Microsomes, Liver/enzymology , Organ Size/drug effects , Risk Assessment , Sensitivity and Specificity , Species Specificity
14.
Cell Death Differ ; 15(9): 1460-71, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18551133

ABSTRACT

In mammalian cells, endoplasmic reticulum (ER) stress has recently been shown to induce autophagy and the induction requires the unfolded protein response (UPR) signaling pathways. However, little is known whether autophagy regulates UPR pathways and how specific UPR targets might control autophagy. Here, we demonstrated that although ER stress-induced autophagy was suppressed by class III phosphatidylinositol-3'-kinase (PI3KC3) inhibitor 3-methyladenine (3-MA), wortmannin and knockdown of Beclin1 using small interfering RNA (siRNA), only 3-MA suppressed UPR activation. We discovered that the UPR regulator and ER chaperone GRP78/BiP is required for stress-induced autophagy. In cells in which GRP78 expression was knocked down by siRNA, despite spontaneous activation of UPR pathways and LC3 conversion, autophagosome formation induced by ER stress as well as by nutrition starvation was inhibited. GRP78 knockdown did not disrupt PI3KC3-Beclin1 association. However, electron microscopic analysis of the intracellular organelle structure reveals that the ER, a putative membrane source for generating autophagosomal double membrane, was massively expanded and disorganized in cells in which GRP78 was knocked down. ER expansion is known to be dependent on the UPR transcription factor XBP-1. Simultaneous knockdown of GRP78 and XBP-1 recovered normal levels of stress-induced autophagosome formation. Thus, these studies uncover 3-MA as an inhibitor of UPR activation and establish GRP78 as a novel obligatory component of autophagy in mammalian cells.


Subject(s)
Autophagy , Endoplasmic Reticulum/metabolism , Heat-Shock Proteins/physiology , Molecular Chaperones/physiology , Adenine/analogs & derivatives , Adenine/pharmacology , Apoptosis Regulatory Proteins/metabolism , Apoptosis Regulatory Proteins/physiology , Autophagy/drug effects , Beclin-1 , Cell Line , Endoplasmic Reticulum/ultrastructure , Endoplasmic Reticulum Chaperone BiP , Heat-Shock Proteins/antagonists & inhibitors , Heat-Shock Proteins/genetics , Humans , Membrane Proteins/metabolism , Membrane Proteins/physiology , Molecular Chaperones/antagonists & inhibitors , Molecular Chaperones/genetics , Phagosomes/ultrastructure , Phosphatidylinositol 3-Kinases/metabolism , Protein Folding , RNA Interference , Signal Transduction
15.
Exp Eye Res ; 85(1): 23-33, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17531974

ABSTRACT

The goal of this study was to examine the characteristics of electrically induced retinal damage. A retinal prosthesis must be both effective and safe, but most research related to electrical stimulation of the retina has involved measures of efficacy (for example, stimulus threshold), while relatively little research has investigated the safety of electrical stimulation. In this study, a single platinum microelectrode was inserted into the vitreous cavity of normally-sighted adult Long Evans pigmented rats. In one group of animals, no contact was made between the electrode and the retina and current pulses of 0.05 (n=3) and 0.2 (n=6) microC/phase were applied. In a second group, visible contact (slight dimpling of the retina) was made between the electrode and the retina and current pulses of 0.09 (n=4) microC/phase were applied. In both cases, stimulus pulses (biphasic, cathodic first, 1 ms/phase) were applied for 1 h at 100 Hz. Also, control experiments were run with no electrical stimulation with retina contact (n=4) and with no retinal contact (n=3). After stimulation, the animal was survived for 2 weeks with ocular photography and electroretinography (ERG) to document changes. During the follow-up period, retinal changes were observed only when the electrode contacted the retina, with or without electrical stimulation. No difference was noted in ERG amplitude or latency comparing the test eye to the stimulated eye. Histological analysis was performed after sacrifice at 2 weeks. A semi-quantitative method for grading 18 features of retina/RPE/choroidal appearance was established and integer grades applied to both test and control eyes. Using this method and comparing the most severely affected area (highest grade), significant differences (p<0.05) were noted between experiments with retinal contact and without retinal contact in all features except inner nuclear layer thickness. No difference was noted within a group based on the intensity of electrical stimulus applied. The size of the affected area was significantly larger with both retinal contact and electrical stimulation compared to with retinal contact alone. We conclude that mechanical pressure alone and mechanical pressure with excessive electrical stimulation causes damage to the retina but that electrical stimulation coupled with mechanical pressure increases the area of the damage.


Subject(s)
Electric Stimulation/adverse effects , Retina/pathology , Animals , Electrodes , Electroretinography/methods , Fluorescein Angiography/methods , Immunohistochemistry/methods , Photoreceptor Cells/pathology , Pigment Epithelium of Eye/pathology , Rats , Rats, Long-Evans , Retinal Degeneration/etiology , Retinal Degeneration/pathology
16.
Amino Acids ; 30(4): 425-34, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16583308

ABSTRACT

We report an investigation of the site specificity, extent and nature of modification of bovine serum albumin (BSA) incubated with fructose or glucose at physiological temperature and pH. Sites of early glycation (Heyns rearrangement products (HRP) from fructose; fructoselysine (FL) from glucose) as well as advanced glycation (N(epsilon)-(carboxymethyl)lysine; CML) were analyzed by liquid chromatography-mass spectrometry. The major site of modification by fructose, like glucose, is Lysine-524 and this results in, respectively, 31 and 76% loss of the corresponding unmodified tryptic peptide, Gln525-Lys533. In addition, total lysine, HRP, FL, CML and N(epsilon)-(carboxyethyl)lysine in the incubations, was quantified. Almost all of the loss of lysine in the fructose-modified BSA was attributed to the formation of CML, with the yield of CML being up to 17-fold higher than glucose-modified BSA. A mechanism for the formation of CML from the HRP is proposed.


Subject(s)
Fructose/chemistry , Glycation End Products, Advanced/chemical synthesis , Lysine/analogs & derivatives , Serum Albumin, Bovine/chemistry , Amino Acid Sequence , Animals , Binding Sites , Cattle , Chromatography, High Pressure Liquid , Glucose/chemistry , Glycosylation , Hydrogen-Ion Concentration , Kinetics , Lysine/chemical synthesis , Lysine/chemistry , Molecular Sequence Data , Sensitivity and Specificity , Serum Albumin, Bovine/chemical synthesis , Temperature , Time Factors
17.
J Appl Microbiol ; 100(1): 185-94, 2006.
Article in English | MEDLINE | ID: mdl-16405699

ABSTRACT

AIMS: To determine the effects of concentrations of fusaric acid on the growth of several strains of the biocontrol bacterial endophyte Bacillus mojavensis and other species within the Bacillus subtilis group, as well as the genetic relationships within this small group of Gram-positive bacteria, and their antagonisms to Fusarium verticillioides, which produce fusaric acid. METHODS AND RESULTS: The growth of 50 Bacillus strains and species were tested at two concentrations of fusaric acid determined in maize infected by an isolate of F. verticillioides. Molecular characterizations of the strains and species of bacteria were determined with an automated ribotyper. The growth of bacteria measured under both concentrations with an automated turbidometer, Bioscreen, indicated that fusaric acid was toxic to most strains of the bacterial endophyte B. mojavensis. However, the effects of these two concentrations on other Bacillus species varied in that fusaric acid was either bacteriocidal or bacteriostatic to most species. CONCLUSIONS: These data indicate that the concentrations of fusaric acid are inhibitory to the growth of most Bacillus species, some of which are used as biocontrol agents. This suggests that the endophytic and saprophytic states of F. verticillioides and other Fusarium species cannot be controlled by fusaric-acid-sensitive Bacillus species. SIGNIFICANCE AND IMPACT OF STUDY: Mycotoxic Fusarium species, such as F. verticillioides, are competitive because all produce fusaric acid, which is inhibitory to biocontrol bacteria, and mutants tolerant to fusaric acid must be developed in order to be effective on biocontrol bacteria.


Subject(s)
Bacillus/drug effects , Enzyme Inhibitors/pharmacology , Fusaric Acid/pharmacology , Bacillus/genetics , Bacillus/growth & development , Bacillus subtilis/drug effects , Bacillus subtilis/genetics , Bacillus subtilis/growth & development , Culture Media , Deoxyribonuclease EcoRI/metabolism , Food Microbiology , Fusarium/chemistry , Mycoses/microbiology , Pest Control, Biological , Phylogeny , Plant Diseases/microbiology , Ribotyping/methods , Zea mays/microbiology
18.
Mycopathologia ; 159(1): 65-73, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15750733

ABSTRACT

Fusarium verticillioides is an important fungus occupying dual roles in the maize plant. The fungus functions as an endophyte, a fungal/host interaction beneficial to the growth of some plants. At other times, the fungus may function as a mycotoxin producing pathogen. The advantages and/or disadvantages of the endophytic relationship must be established in order to target appropriate sites for controlling diseases and mycotoxins in maize. One possibility could be to ensure seed maize is fungal free prior to planting. Reciprocal inoculations were made with two fungal isolates on seed of two maize genotypes. Yield was measured at harvest by ear and seed characters and vegetative growth at one-month intervals for plant survival, height, weight and stem diameter. Yield and vegetative growth differed among mature plants only once based on seed inoculation status. In 1998, plant weight was reduced and seed weight per ear was increased for the dent maize, GT-MAS: gk, grown from F. verticillioides RRC 374-inoculated seed compared to other seed treatments. Most vegetative characters were reduced at the first collection for Silver Queen plants grown from F. verticillioides-inoculated seed in 1997 and 1999, but not in 1998. However, no significant differences occurred among mature Silver Queen plants during any of the three growing seasons. In conclusion, yield and vegetative growth of mature maize plants grown from F. verticillioides-inoculated seed were equal to or greater than plants grown from non-inoculated seed under south Georgia field conditions during 1997, 1998, and 1999.


Subject(s)
Fusarium/growth & development , Seeds/microbiology , Zea mays/growth & development , Zea mays/microbiology , Climate , Georgia , Symbiosis
19.
Arch Environ Contam Toxicol ; 48(1): 87-98, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15657810

ABSTRACT

Using original artificial fertilization methods with medaka (Oryzias latipes), the effects of exposure to cypermethrin on gametes, fertilization, and embryonic development were investigated. The relative sensitivity was studied with 96-hour duration, 24-hour renewal exposures to six nominal concentrations of cypermethrin ranging from 3.1 100.0 microg cypermethrin/L. Tests were initiated at different developmental stages: unfertilized egg (stage 0), late morula (stage 9), eminence of swim bladder (stage 29), and maximum flexion of the atrioventricular region (stage 34). Cypermethrin did not affect the fertilization process. Predominant sublethal effects in embryos included transient visceral edemas intimately associated to the gall bladder with subsequent pericardial edemas. Other sublethal effects were observed in surviving larvae and included spastic movements with or without ability to respond to stimulus (>/=6.3 microg cypermethrin/L), spinal curvatures, and delayed or absence of swim bladder inflation (>/=12.5 microg cypermethrin/L). The exposure of the gametes (stage 0) or animals during earlier embryonic development (stages 9 or 29) was not a critical window for cypermethrin exposure. Although the incidence of edemas in embryos occurred mainly during exposure of these early developmental stages, embryo and larva lethality and the incidence of transient sublethal effects in hatchlings showed that the later exposure window (stage 34) was the most sensitive. The stage 34 group involved advanced organogenetic stages in which the chorion partially degraded before hatching. Our studies reinforced the idea that a combination of morphologic and functional impairment evaluation is a more sensitive response to developmental toxicants than morphologic defects alone.


Subject(s)
Insecticides/toxicity , Oryzias/embryology , Pyrethrins/toxicity , Water Pollutants, Chemical/toxicity , Animals , Biological Assay/methods , Embryo, Nonmammalian/drug effects , Embryo, Nonmammalian/physiology , Fertilization in Vitro , Larva/drug effects , Larva/physiology , Oryzias/physiology , Ovum/drug effects , Ovum/physiology
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