Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 217
Filter
1.
PLoS One ; 13(12): e0207408, 2018.
Article in English | MEDLINE | ID: mdl-30540758

ABSTRACT

Interest in the individual differences underlying end user computer security behavior has led to the development of a multidisciplinary field of research known as behavioral information security. An important gap in knowledge and the motivation for this research is the development of ways to measure secure and insecure cyber behavior for research and eventually practice. Here we report a study designed to develop a technique for assessing secure and insecure cyber behavior for broad research use. The Susceptibility and Resilience to Cyber Threat (SRCT) is an immersive scenario decision program. The SRCT measures susceptibility to cyber threat and malicious behavior as well protective resilience actions via participant responses/decisions to emails, interactions with security dialogs, and computer actions in a real-world simulation. Data were collected from a sample of 190 adults (76.3% female), between the ages of 18-61 (mean age = 26.12). Personality, behavioral tendencies, and cognitive preferences were measured with standard previously validated protocols and self-report measures. Factor analysis suggested a 5 item secure actions scale and a 9 item insecure actions scale as viable to extract from the SRCT responses. Statistically analyzable distributions of secure and insecure cyber behaviors were obtained, and these subscales demonstrated acceptable internal consistency as hypothesized. Associations between SRCT scales and other indices of cyber behavior, as well as self-reported personality, were lower than predicted, suggesting that past research reporting links between self-reports of personality and self-reported cyber-behavior may be overestimating the links for actual cyber actions. However, our exploratory analyses suggest discrepancies between self-report and actions in the SRCT may be an interesting avenue to explore. Overall, results were consistent with theorizing and suggest the technique is viable as a construct measure in future research or as an outcome variable in experimental intervention designs.


Subject(s)
Computer Security , Risk Management , Adolescent , Adult , Computer Communication Networks , Female , Humans , Male , Middle Aged , Software , Young Adult
2.
J Sci Med Sport ; 21(12): 1215-1220, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29843960

ABSTRACT

OBJECTIVES: To determine injury risk-workload associations in collegiate American Football. DESIGN: Retrospective analysis. METHODS: Workload and injury data was recorded from 52 players during a full NCAA football season. Acute, chronic, and a range of acute:chronic workload ratios (ACWR: 7:14, 7:21 and 7:28 day) calculated using rolling and exponentially weighted moving averages (EWMA) were plotted against non-contact injuries (regardless of time lost or not) sustained within 3- and 7-days. Injury risks were also determined relative to position and experience. RESULTS: 105 non-contact injuries (18 game- and 87 training-related) were observed with almost 40% sustained during the pre-season. 7-21 day EWMA ACWR's with a 3-day injury lag were most closely associated with injury (R2=0.54). Relative injury risks were >3× greater with high compared to moderate and low ratios and magnified when combined with low 21-day chronic workloads (injury probability=92.1%). Injury risks were similar across positions. 'Juniors' presented likely and possibly increased overall injury risk compared to 'Freshman' (RR: 1.94, CI 1.07-3.52) and 'Seniors' (RR: 1.7, CI 0.92-3.14), yet no specific ACWR - experience or - position interactions were identified. CONCLUSIONS: High injury rates during college football pre-season training may be associated with high acute loads. In-season injury risks were greatest with high ACWR and evident even when including (more common and less serious) non-time loss injuries. Substantially increased injury risks when low 21-day chronic workloads and concurrently high EWMA ACWR highlights the importance of load management for individuals with chronic game- (non-involved on game day) and or training (following injury) absences.


Subject(s)
Athletic Injuries/epidemiology , Football/injuries , Workload , Humans , Male , Risk Factors , United States , Universities
3.
J Anim Sci ; 90(12): 4297-307, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22829611

ABSTRACT

Foraging behavior is an expression of learning, context, and experience arising from integration of sensory information obtained during feeding with postingestive consequences of food ingestion. Although it has been well established that gustatory and olfactory systems of the mouth and nose provide sensory information to the consumer (in the form of flavor), sweet and bitter taste receptors have recently been identified in the intestinal tract of humans and rodents. It remains possible that sensory information generated in the gut could contribute to the learning process. Thus, a series of experiments was conducted to determine if classical associative learning occurs when the conditional stimulus circumvents oronasal presentation via direct delivery to the gut or peritoneal cavity. Mice receiving an intragastric infusion of 5 mM sodium saccharin immediately followed by LiCl administration demonstrated a significant decrease in preference for 5 mM saccharin in 4 consecutive 23 h, 2-bottle preference tests versus water (P = 0.0053). Saccharin was highly preferred in mice receiving intragastric (IG) saccharin only or interperitoneal (i.p.) injection of LiCl only. This reduced preference indicated that mice "tasted" saccharin infused into the gut. However, efforts to replicate with a reduced infusion volume failed to result in decreased preference. To understand if there were alternative pathways for oral detection of infused saccharin, mice received intragastric infusions (5.4 mM) and i.p. injections (10.8 mM) of sodium fluorescein. Fluorescence was observed from the tongues and esophagi of mice infused with volumes of 0.5 mL or more or injected with volumes of 0.25 mL or greater. Interperitoneal injections of 5 mM saccharin in mice resulted in reduced preference for 5 mM saccharin presented orally in 2-bottle preference tests (P = 0.0287). Oral delivery of a 500-fold less concentration of saccharin (0.01 mM) during conditioning resulted in a similar preference expression as shown in the initial IG experiment. These results demonstrate that although compounds may be tasted in the mouth absent of oral contact, associative learning is attenuated. Therefore, intestinal taste receptors are unlikely to participate directly in learning and recognition of foods during foraging events.


Subject(s)
Feeding Behavior/physiology , Gastrointestinal Tract/physiology , Learning/physiology , Lithium Chloride/pharmacology , Saccharin/pharmacology , Taste/physiology , Animals , Male , Mice , Sweetening Agents/pharmacology
4.
Clin Pharmacol Ther ; 91(1): 134-42, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22130119

ABSTRACT

Phosphodiesterases (PDEs) are important modulators of inflammation and wound healing. In this capacity, specific targeting of PDEs for the treatment of many diseases, including chronic obstructive pulmonary disease (COPD), has been investigated. Currently, treatment of COPD is suboptimal. PDE4 modulates the inflammatory response of the lung, and inhibition of PDE4 may be a novel, COPD-specific approach toward more effective treatment strategies. This review describes the state of PDE4-inhibitor therapy for use in COPD treatment.


Subject(s)
Drug Delivery Systems/trends , Phosphodiesterase 4 Inhibitors/administration & dosage , Pulmonary Disease, Chronic Obstructive/drug therapy , Pulmonary Disease, Chronic Obstructive/enzymology , Animals , Cyclic Nucleotide Phosphodiesterases, Type 4/metabolism , Drug Delivery Systems/methods , Humans , Treatment Outcome
5.
J Forensic Odontostomatol ; 29(2): 29-37, 2011 Dec 01.
Article in English | MEDLINE | ID: mdl-22717911

ABSTRACT

In most crimes where bite marks are discovered, photographic accuracy is crucial to the investigative process since in many instances the bite mark(s) may be the only evidence linking a particular suspect to the crime. Therefore, the rationale for employing superior photographic principles is mandatory for the investigation team. This paper will discuss current standards, best practice, and armamentaria for digital photography of bite mark injuries on skin. Full spectrum protocols will be described including Alternate Light Imaging, Reflective Ultra-violet, and Infrared techniques for photo-documentation of images of bite marks and other bruise patterns that have been inflicted on human skin.


Subject(s)
Bites, Human/pathology , Photography, Dental , Forensic Anthropology/methods , Forensic Dentistry/methods , Humans , Image Processing, Computer-Assisted , Information Management , Infrared Rays , Light , Photography, Dental/methods , Photography, Dental/standards , Software , Ultraviolet Rays
6.
Epilepsy Res ; 58(2-3): 175-83, 2004 Feb.
Article in English | MEDLINE | ID: mdl-15120748

ABSTRACT

PURPOSE: Our research program uses genetic linkage and association analysis to identify human seizure sensitivity and resistance alleles. Quantitative trait loci mapping in mice led to identification of genetic variation in the potassium ion channel gene Kcnj10, implicating it as a putative seizure susceptibility gene. The purpose of this work was to translate these animal model data to a human genetic association study. METHODS: We used single stranded conformation polymorphism (SSCP) electrophoresis, DNA sequencing and database searching (NCBI) to identify variation in the human KCNJ10 gene. Restriction fragment length polymorphism (RFLP) analysis, SSCP and Pyrosequencing were used to genotype a single nucleotide polymorphism (SNP, dbSNP rs#1130183) in KCNJ10 in epilepsy patients (n = 407) and unrelated controls (n = 284). The epilepsy group was comprised of patients with refractory mesial temporal lobe epilepsy (n = 153), childhood absence (n = 84), juvenile myoclonic (n = 111) and idiopathic generalized epilepsy not otherwise specified (IGE-NOS, n = 59) and all were of European ancestry. RESULTS: SNP rs#1130183 (C > T) alters amino acid 271 (of 379) from an arginine to a cysteine (R271C). The C allele (Arg) is common with conversion to the T allele (Cys) occurring twice as often in controls compared to epilepsy patients. Contingency analysis documented a statistically significant association between seizure resistance and allele frequency, Mantel-Haenszel chi square = 5.65, d.f. = 1, P = 0.017, odds ratio 0.52, 95% CI 0.33-0.82. CONCLUSION: The T allele of SNP rs#1130183 is associated with seizure resistance when common forms of focal and generalized epilepsy are analyzed as a group. These data suggest that this missense variation in KCNJ10 (or a nearby variation) is related to general seizure susceptibility in humans.


Subject(s)
Genetic Predisposition to Disease/genetics , Genetic Variation/genetics , Potassium Channels, Inwardly Rectifying , Potassium Channels/genetics , Seizures/genetics , Chi-Square Distribution , Confidence Intervals , Gene Frequency/genetics , Genotype , Humans , Odds Ratio , Quantitative Trait Loci/genetics
7.
J Cardiovasc Pharmacol Ther ; 7 Suppl 1: S7-S10, 2002 Jan.
Article in English | MEDLINE | ID: mdl-12011966

ABSTRACT

UNLABELLED: The aim of this study was to demonstrate whether HR (Paroven-Venoruton; 0-(beta-hydroxyethyl)-rutosides), was effective in improving the microcirculation in venous hypertension and microangiopathy. Sixty patients with severe venous hypertension due to chronic venous insufficiency, ankle swelling, and lipodermatosclerosis were included. After informed consent, patients were randomized into a treatment group and a placebo group. Patients in the treatment group received oral HR (2 g/day for 8 weeks); those in the placebo group received a comparable placebo. RESULTS: The two groups were comparable for age and sex distribution. The mean age was 45 years (SD 9) in the treatment group (31 patients) and 45.5 (SD 10) in the placebo group (29 patients). There were no differences between the placebo and treatment groups at inclusion. There was no change between inclusion and measurements at 8 weeks in the placebo group. A significant decrease (P < 0.05) in flux at rest and rate of ankle swelling was observed in the treatment group. The decrease in capillary filtration was associated with improvement in signs and symptoms (P < 0.05). The difference in flux, sign and symptoms, and filtration was clinically important at 8 weeks in the treatment group when compared with the placebo group. No adverse effects were observed. CONCLUSION: Venous microangiopathy was improved by HR treatment.


Subject(s)
Hydroxyethylrutoside/analogs & derivatives , Hydroxyethylrutoside/pharmacology , Hypertension/complications , Vascular Diseases/drug therapy , Vasoconstrictor Agents/pharmacology , Adult , Edema , Female , Humans , Male , Microcirculation , Middle Aged , Placebos , Prospective Studies , Skin Ulcer , Treatment Outcome , Venous Insufficiency/drug therapy , Venous Insufficiency/etiology
8.
Neuropsychobiology ; 44(3): 150-5, 2001.
Article in English | MEDLINE | ID: mdl-11586055

ABSTRACT

Two genetically different strains, Brown Norway rats (BNR) and Wistar Kyoto rats (WKR), with the latter showing higher emotionality and lower plasma stress catecholamine responses, were compared for their voluntary intake of ethanol, nicotine, cocaine and morphine. Younger BNR self-administered the same amounts of all 4 substances as did the younger WKR suggesting a similar genetic basis for all drugs at this age. Older BNR consumed less ethanol and nicotine but equal amounts of cocaine and morphine as compared to older WKR, and older BNR were more sensitive to the effects of ethanol than WKR suggesting a different genetic basis for different drugs at an older age. Forcing both strains to consume one of the drugs did not affect a subsequent voluntary consumption of ethanol and morphine but reduced nicotine intake in WKR and decreased cocaine intake in both strains suggesting that drug use is determined by individual preferences and not drug exposure per se. The behavioral characteristics of both strains coincide only with the self-administration of ethanol and nicotine supporting a possible genetic linkage between anxiety/stress and ethanol and nicotine use.


Subject(s)
Aging/physiology , Behavior, Animal/physiology , Cocaine/administration & dosage , Cocaine/pharmacology , Ethanol/administration & dosage , Ethanol/pharmacology , Morphine/administration & dosage , Morphine/pharmacology , Nicotine/administration & dosage , Nicotine/pharmacology , Rats, Inbred Strains , Self Administration , Administration, Oral , Animals , Male , Rats , Rats, Inbred BN , Rats, Inbred WKY
9.
Genomics ; 75(1-3): 35-42, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11472065

ABSTRACT

We conducted a quantitative trait locus (QTL) mapping study to dissect the multifactorial nature of maximal electroshock seizure threshold (MEST) in C57BL/6 (B6) and DBA/2 (D2) mice. MEST determination involved a standard paradigm in which 8- to 12-week-old mice received one shock per day with a daily incremental increase in electrical current until a maximal seizure (tonic hindlimb extension) was induced. Mean MEST values in parental strains were separated by over five standard deviation units, with D2 mice showing lower values than B6 mice. The distribution of MEST values in B6xD2 F2 intercrossed mice spanned the entire phenotypic range defined by parental strains. Statistical mapping yielded significant evidence for QTLs on chromosomes 1, 2, 5, and 15, which together explained over 60% of the phenotypic variance in the model. The chromosome 1 QTL represents a locus of major effect, accounting for about one-third of the genetic variance. Experiments involving a congenic strain (B6.D2-Mtv7(a)/Ty) enabled more precise mapping of the chromosome 1 QTL and indicate that it lies in the genetic interval between markers D1Mit145 and D1Mit17. These results support the hypothesis that the distal portion of chromosome 1 harbors a gene(s) that has a fundamental role in regulating seizure susceptibility.


Subject(s)
Electroshock , Pain Threshold , Animals , Chromosome Mapping , Crosses, Genetic , Epilepsy/genetics , Genetic Markers , Genetic Predisposition to Disease , Genotype , Mice , Mice, Congenic , Mice, Inbred C57BL , Microsatellite Repeats , Models, Statistical , Phenotype , Polymorphism, Genetic , Quantitative Trait, Heritable , Sex Factors
10.
J Bacteriol ; 183(13): 3967-73, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11395460

ABSTRACT

In Pseudomonas putida DOT-T1E multidrug efflux pumps of the resistance-nodulation-division family make a major contribution to solvent resistance. Two pumps have been identified: TtgABC, expressed constitutively, and TtgDEF, induced by aromatic hydrocarbons. A double mutant lacking both efflux pumps was able to survive a sudden toluene shock if and only if preinduced with small amounts of toluene supplied via the gas phase. In this article we report the identification and characterization in this strain of a third efflux pump, named TtgGHI. The ttgGHI genes form an operon that is expressed constitutively at high levels from a single promoter. In the presence of toluene the operon is expressed at an even higher level from two promoters, the constitutive one and a previously unreported one that is inducible and that partially overlaps the constitutive promoter. By site-directed mutagenesis we constructed a single ttgH mutant which was shown to be unable to survive sudden 0.3% (vol/vol) toluene shocks regardless of the preculture conditions. The mutation was transferred to single and double mutants to construct mutant strains in which two or all three pumps are knocked out. Survival analysis of induced and noninduced cells revealed that the TtgABC and TtgGHI pumps extruded toluene, styrene, m-xylene, ethylbenzene, and propylbenzene, whereas the TtgDEF pump removed only toluene and styrene. The triple mutant was hypersensitive to toluene, as shown by its inability to grow with toluene supplied via the vapor phase.


Subject(s)
Bacterial Proteins , Biological Transport, Active/physiology , Genes, Bacterial , Membrane Transport Proteins , Pseudomonas putida/metabolism , Toluene/metabolism , Anti-Bacterial Agents/metabolism , Base Sequence , Benzene Derivatives/metabolism , Carrier Proteins/genetics , Carrier Proteins/metabolism , Cloning, Molecular , Drug Resistance, Microbial , Molecular Sequence Data , Mutagenesis, Insertional , Pseudomonas putida/drug effects , Toluene/pharmacology
11.
Neuropsychopharmacology ; 24(3): 291-9, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11166519

ABSTRACT

Mature male and female mice from six inbred stains were tested for susceptibility to behavioral seizures induced by a single injection of cocaine. Cocaine was injected ip over a range of doses (50-100 mg/kg) and behavior was monitored for 20 minutes. Seizure end points included latency to forelimb or hindlimb clonus, latency to clonic running seizure and latency to jumping bouncing seizure. A range of strain specific sensitivities was documented with A/J and SJL mice being most sensitive and C57BL/6J most resistant. DBA/2J, BALB/cByJ and NZW/LacJ strains exhibited intermediate sensitivity. EEG recordings were made in SJL, A/J and C57BL/6J mice revealing a close correspondence between electrical activity and behavior. Additionally, levels of cocaine determined in hippocampus and cortex were not different between sensitive and resistant strains. Additional studies of these murine strains may be useful for investigating genetic influences on cocaine-induced seizures.


Subject(s)
Brain/metabolism , Cocaine/pharmacokinetics , Cocaine/toxicity , Disease Models, Animal , Kainic Acid/pharmacokinetics , Kainic Acid/toxicity , Mice, Inbred Strains , Seizures/chemically induced , Animals , Brain/drug effects , Cerebral Cortex/metabolism , Cocaine/administration & dosage , Dose-Response Relationship, Drug , Electroencephalography , Female , Genetic Predisposition to Disease , Hippocampus/metabolism , Kainic Acid/administration & dosage , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Inbred DBA , Seizures/genetics
12.
Pharmacol Biochem Behav ; 66(2): 397-401, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10880696

ABSTRACT

Extracellular dopamine levels were determined by microdialysis in the core and shell of the nucleus accumbens and the frontal cortex of rats before and after an injection of cocaine (20 mg/kg, IP). After removal of the probes, these same animals were then tested for their voluntary intake of cocaine using the two-bottle, free-choice paradigm. Baseline dopamine levels and their responses to an injection of cocaine differed among the three brain areas. No significant correlations were found between baseline dopamine levels in any of the three brain regions and the voluntary cocaine consumption. A significant negative correlation was found between cocaine-induced increases in extracellular dopamine in the shell of the nucleus accumbens and the voluntary intake of cocaine (r = -0.73, p < 0.01). No such correlations were observed in the accumbens core region or the frontal cortex. These results provide further evidence of the role of the accumbal shell region in cocaine preference, and indicate that cocaine-induced increases in dopamine levels play a role in oral cocaine self-administration or preference. In addition, this relatively novel approach in using the same animals for both cocaine induced neurotransmitter responses and cocaine preference studies can also be applied for the study of other neurotransmitters and drugs of abuse.


Subject(s)
Cocaine/administration & dosage , Dopamine/metabolism , Nucleus Accumbens/drug effects , Nucleus Accumbens/metabolism , Animals , Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Cocaine/pharmacology , Cocaine-Related Disorders/metabolism , Male , Rats , Rats, Sprague-Dawley , Self Administration
13.
Acad Med ; 75(5): 426-31, 2000 May.
Article in English | MEDLINE | ID: mdl-10824764

ABSTRACT

In 1998, the authors, acting on behalf of the National Board of Medical Examiners (NBME), undertook a review of the scoring policy for the United States Medical Licensing Examination (USMLE). The main goal was to determine the likely effect of changing from numeric score reporting to reporting pass-fail status. Several groups were surveyed across the nation to learn how they felt they would be affected by such a change, and why: all 54 medical boards; 1,600 randomly selected examinees (including 250 foreign medical graduates) who had recently taken either Step 1, Step 2, or Step 3 of the USMLE; 2,000 residency directors; the deans, education deans, and student affairs deans at all 125 U.S. medical schools accredited by the Liaison Committee on Medical Education; and all 17 members of the Council of Medical Specialty Societies. Responses from the different groups surveyed varied from 80% to a little less than half. The authors describe in detail the various views of the respondents and their reasons. Some members in each group favored each of the reporting formats, but the trend was to favor numeric score reporting. The majority of the responding examinees desired that their USMLE scores be sent to them in numeric form but sent to their schools and to residency directors in pass-fail form. Based on the responses and a thorough discussion of their implications, the Composite Committee (which determines USMLE score-reporting policy) decided that there is no basis at this time for changing the current policy, but that it would review the policy in the future when necessary.


Subject(s)
Clinical Competence/statistics & numerical data , Educational Measurement , Licensure , Data Collection , United States
15.
Life Sci ; 65(12): 1247-55, 1999.
Article in English | MEDLINE | ID: mdl-10503940

ABSTRACT

We determined whether two naturally occurring steroids, cortisol and 17beta-estradiol (E2), can rapidly modulate the activity of an important membrane protein, human erythrocyte (RBC) Na+,K+-ATPase, an enzyme that does not bind either hormone directly. We also determined the membrane binding locations for cortisol and E2 and their effects on membrane molecular structure and fluidity. Direct application of both steroids to intact human RBC significantly altered maximum ouabain-sensitive 86Rb uptake within 5 min: Cortisol decreased it by 24%, whereas E2 increased it by 18%. As determined by small angle x-ray diffraction, these steroids occupied distinct time-averaged binding locations in the RBC membrane, cortisol localizing near the bilayer surface, 14-29 A from the bilayer center, and E2 localizing deep within the hydrocarbon core, 0-7 A from the bilayer center. Neither steroid significantly changed overall bilayer width or membrane fluidity. These data suggest that cell membrane protein function can be altered rapidly and differentially by naturally occurring steroids. This effect did not appear to be related to the different binding locations of the steroids in the membrane or to their influence on membrane fluidity.


Subject(s)
Cell Membrane/metabolism , Erythrocytes/enzymology , Estradiol/pharmacology , Hydrocortisone/pharmacology , Sodium-Potassium-Exchanging ATPase/metabolism , Adult , Cell Membrane/drug effects , Estradiol/metabolism , Female , Humans , Hydrocortisone/metabolism , Lipid Bilayers/chemistry , Male , Middle Aged , Spectrometry, Fluorescence , X-Ray Diffraction
16.
J Neurosci ; 19(16): 6733-9, 1999 Aug 15.
Article in English | MEDLINE | ID: mdl-10436030

ABSTRACT

DBA/2J (D2) and C57BL/6J (B6) mice exhibit differential sensitivity to seizures induced by various chemical and physical methods, with D2 mice being relatively sensitive and B6 mice relatively resistant. We conducted studies in mature D2, B6, F1, and F2 intercross mice to investigate behavioral seizure responses to pentylenetetrazol (PTZ) and to map the location of genes that influence this trait. Mice were injected with PTZ and observed for 45 min. Seizure parameters included latencies to focal clonus, generalized clonus, and maximal seizure. Latencies were used to calculate a seizure score that was used for quantitative mapping. F2 mice (n = 511) exhibited a wide range of latencies with two-thirds of the group expressing maximal seizure. Complementary statistical analyses identified loci on proximal (near D1Mit11) and distal chromosome 1 (near D1Mit17) as having the strongest and most significant effects in this model. Another locus of significant effect was detected on chromosome 5 (near D5Mit398). Suggestive evidence for additional PTZ seizure-related loci was detected on chromosomes 3, 4, and 6. Of the seizure-related loci identified in this study, those on chromosomes 1 (distal), 4, and 5 map close to loci previously identified in a similar F2 population tested with kainic acid. Results document that the complex genetic influences controlling seizure response in B6 and D2 mice are partially independent of the nature of the chemoconvulsant stimulus with a locus on distal chromosome 1 being of fundamental importance.


Subject(s)
Chromosome Mapping , Convulsants/toxicity , Pentylenetetrazole/toxicity , Seizures/etiology , Animals , Female , Genetic Predisposition to Disease , Genome , Genotype , Lod Score , Male , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , Quantitative Trait, Heritable , Seizures/chemically induced , Seizures/genetics
17.
Psychiatr Genet ; 8(4): 227-33, 1998.
Article in English | MEDLINE | ID: mdl-9861641

ABSTRACT

Agarose gel electrophoresis with ethidium bromide staining (AGE/EBS) is an efficient and reliable method for analyzing microsatellite polymorphisms. We report the use of AGE/EBS for analyzing DNA microsatellite polymorphisms in a preliminary quantitative trait loci (QTL) study of seizure susceptibility in which a candidate gene strategy was used to direct initial mapping efforts. F2 intercross progeny, derived from seizure-sensitive DBA/2J (D2) and seizure-resistant C57BL/6J (B6) inbred strains of mice, were tested for their sensitivity to the seizure-inducing effect of pentylenetetrazol (PTZ), a gamma-aminobutyric acid (GABA) receptor antagonist. A semi-automated method is described, in which DNA microsatellites were amplified by polymerase chain reaction (PCR) to yield products of 100-200 base pair (bp) in length. Alleles were separated on 3-6% MetaPhor agarose gels, stained with ethidium bromide, and visualized by ultraviolet (UV) illumination. Univariate analysis of genotype and phenotype data provides evidence for a seizure-related QTL on chromosome 5, near genes coding for the GABAA receptor subunits alpha 5 and gamma 3. Interestingly, this suggestive QTL derives from the more resistant B6 strain, but it nonetheless provides impetus for the characterization of possible strain differences in these two candidate genes. Overall, these results demonstrate that AGE/EBS can be useful for rapid screening of genomic regions of special interest in QTL mapping studies.


Subject(s)
Electrophoresis, Agar Gel/methods , Mice, Inbred C57BL/genetics , Mice, Inbred DBA/genetics , Microsatellite Repeats , Quantitative Trait, Heritable , Receptors, GABA-A/genetics , Seizures/genetics , Animals , Chromosome Mapping , Convulsants/toxicity , Crosses, Genetic , DNA/analysis , DNA/genetics , Drug Resistance , Ethidium , Female , Fluorescent Dyes , GABA-A Receptor Antagonists , Genetic Predisposition to Disease , Genotype , Male , Mice , Pentylenetetrazole/toxicity , Seizures/chemically induced , Staining and Labeling
18.
Brain Res ; 813(1): 207-10, 1998 Nov 30.
Article in English | MEDLINE | ID: mdl-9824700

ABSTRACT

C57BL/6J (B6) and DBA/2J (D2) mice have been characterized previously as seizure-resistant and seizure-sensitive, respectively, a distinction based primarily upon a differential response to the convulsant effects of various drugs. In the present study, electroconvulsive shock (ECS) was used to assess maximal electroshock threshold (MET) in B6, D2 and hybrid mice. Results revealed that D2 mice have a significantly lower MET compared to B6 mice. There was also a significant gender effect for B6 and F2 mice with females exhibiting a lower MET compared to males. METs for F1 and F2 intercross mice were intermediate between the two parental strains. The difference in variance between F2 and F1 generation mice indicated that about three-quarters of the total variance is due to genetic influence. Taken together, results of this study suggest that the large difference in MET between B6 and D2 mice is a highly heritable trait which may yield to genetic dissection through use of quantitative trait locus mapping.


Subject(s)
Seizures/etiology , Animals , Electroshock , Female , Male , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , Quantitative Trait, Heritable , Seizures/genetics , Species Specificity
19.
Proc Natl Acad Sci U S A ; 95(14): 8322-7, 1998 Jul 07.
Article in English | MEDLINE | ID: mdl-9653185

ABSTRACT

The clinicopathological phenotype of the Gerstmann-Sträussler-Scheinker disease (GSS) variant linked to the codon 102 mutation in the prion protein (PrP) gene (GSS P102L) shows a high heterogeneity. This variability also is observed in subjects with the same prion protein gene PRNP haplotype and is independent from the duration of the disease. Immunoblot analysis of brain homogenates from GSS P102L patients showed two major protease-resistant PrP fragments (PrP-res) with molecular masses of approximately 21 and 8 kDa, respectively. The 21-kDa fragment, similar to the PrP-res type 1 described in Creutzfeldt-Jakob disease, was found in five of the seven subjects and correlated with the presence of spongiform degeneration and "synaptic" pattern of PrP deposition whereas the 8-kDa fragment, similar to those described in other variants of GSS, was found in all subjects in brain regions showing PrP-positive multicentric amyloid deposits. These data further indicate that the neuropathology of prion diseases largely depends on the type of PrP-res fragment that forms in vivo. Because the formation of PrP-res fragments of 7-8 kDa with ragged N and C termini is not a feature of Creutzfeldt-Jakob disease or fatal familial insomnia but appears to be shared by most GSS subtypes, it may represent a molecular marker for this disorder.


Subject(s)
Gerstmann-Straussler-Scheinker Disease/genetics , Gerstmann-Straussler-Scheinker Disease/metabolism , Gerstmann-Straussler-Scheinker Disease/physiopathology , Mutation , Prions/genetics , Adult , Aged , Female , Genetic Markers , Humans , Male , Middle Aged , Peptide Fragments/genetics , Peptide Fragments/metabolism , Prions/metabolism
20.
Clin Neuropharmacol ; 21(3): 181-9, 1998.
Article in English | MEDLINE | ID: mdl-9617510

ABSTRACT

There is strong evidence to support the hypothesis that the rapid effects of steroids on neurons are membrane-mediated. Rapid steroid effects have been demonstrated in the absence of intracellular receptors, in the presence of RNA or protein synthesis inhibitors, and in response to steroids coupled to large proteins that block access to intracellular receptors. This study selectively reviewed the emerging body of evidence suggesting that steroids have multiple sites of cellular actions, and explored in depth one possible membrane-mediated mechanism of action, the membrane-intercalation model.


Subject(s)
Cell Membrane/drug effects , Lipid Bilayers/metabolism , Steroids/pharmacology , Biophysical Phenomena , Biophysics , Cholesterol/pharmacology , Female , Humans , Lipid Bilayers/chemistry , Male , Models, Molecular , X-Ray Diffraction
SELECTION OF CITATIONS
SEARCH DETAIL
...