PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “DOMS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,441 records · Page 80Linked to original sources

A three-choice discrimination procedure dissociates the discriminative stimulus effects of d-amphetamine and (+/-)-MDMA in rats.

(+/-)-3,4-Methylenedioxymethamphetamine (MDMA) produces subjective effects in humans that are similar to, but distinguishable from, those of psychostimulants. Drug discrimination studies in nonhumans have yielded inconsistent results regarding the similarities between MDMA and the psychomotor stimulant d-amphetamine. This study successfully used a 3-choice operant procedure to establish MDMA and d-amphetamine as discriminative stimuli in rats. Cocaine produced complete substitution for d-amphetamine, and LSD produced dose-dependent increases in MDMA-appropriate responding with nearly complete substitution (78%) for MDMA. The hallucinogen 2,5-dimethoxy-4-bromoamphetamine only partially substituted for MDMA and severely disrupted response rate. Fenfluramine and both isomers of 3,4-methylenedioxyamphetamine (MDA) all produced complete substitution for MDMA. The serotonin-receptor antagonist pirenpirone only partially blocked MDMA discrimination.

DOM 2,5-Dimethoxy-4-Methylamphetamine↗

Resistance to HIV-1 infection in caucasian individuals bearing mutant alleles of the CCR-5 chemokine receptor gene.

HIV-1 and related viruses require co-receptors, in addition to CD4, to infect target cells. The chemokine receptor CCR-5 (ref.1) was recently demonstrated to be a co-receptor for macrophage-tropic (M-tropic) HIV-1 strains, and the orphan receptor LESTR (also called fusin) allows infection by strains adapted for growth in transformed T-cell lines (T-tropic strains). Here we show that a mutant allele of CCR-5 is present at a high frequency in caucasian populations (allele frequency, 0.092), but is absent in black populations from Western and Central Africa and Japanese populations. A 32-base-pair deletion within the coding region results in a frame shift, and generates a non-functional receptor that does not support membrane fusion or infection by macrophage- and dual-tropic HIV-1 strains. In a cohort of HIV-1 infected caucasian subjects, no individual homozygous for the mutation was found, and the frequency of heterozygotes was 35% lower than in the general population. White blood cells from an individual homozygous for the null allele were found to be highly resistant to infection by M-tropic HIV-1 viruses, confirming that CCR-5 is the major co-receptor for primary HIV-1 strains. The lower frequency of heterozygotes in seropositive patients may indicate partial resistance.

Alleles↗

Diversity of receptors binding HIV on dendritic cell subsets.

The ability of HIV-1 to use dendritic cells (DCs) for transport and to transfer virus to activated T cells in the lymph node may be crucial in early HIV-1 pathogenesis. We have characterized primary DCs for the receptors involved in viral envelope attachment and observed that C-type lectin receptor (CLR) binding was predominant in skin DCs, whereas binding to emigrating and tonsil DCs was CD4-dependent. No one CLR was solely responsible for envelope binding on all skin DC subsets. DC-SIGN (DC-specific ICAM-3-grabbing nonintegrin) was only expressed by CD14(+)CDla(lo) dermal DCs. The mannose receptor was expressed by CD1a(hi) and CD14(+)CDla(lo) dermal DCs, and langerin was expressed by Langerhans cells. The diversity of CLRs able to bind HIV-1 in skin DCs may reflect their ability to bind a range of microbial glycoproteins.

Antigens, CD↗

Alzheimer's A beta(1-42) is generated in the endoplasmic reticulum/intermediate compartment of NT2N cells.

Alzheimer's disease (AD) is a neurodegenerative disorder involving the florid deposition of vascular and cerebral plaques composed chiefly of amyloid beta-peptide (A beta) derived from cleavage of the amyloid precursor protein (APP). Varying in length from 39 to 43 amino acids, A beta, particularly the longer A beta(42), is thought to play a significant role in AD pathogenesis. To better understand AD it is important to identify the subcellular organelles generating A beta. Studies using agents that disrupt endosomal/lysosomal function suggest that A beta is generated late in the secretory and endocytic pathways. However, much of what is known about A beta biosynthesis has been inferred by monitoring extracellular A beta levels since intracellular A beta is undetectable in most cell types. Consequently, the precise site or sites that generate A beta, or whether A beta(1-40) and A beta(1-42) are generated at the same point in the biosynthetic pathway, is not known. Using human NT2N neurons, we found that retention of APP in the endoplasmic reticulum/intermediate compartment (ER/IC) by three independent approaches eliminated production of intracellular A beta(1-40), but did not alter intracellular A beta(1-42) synthesis. These findings suggest that the ER/IC may be an important site for generating this highly amyloidogenic species of A beta.

Alzheimer Disease↗

Presenilins are not required for A beta 42 production in the early secretory pathway.

Presenilins 1 and 2 (PS1/PS2) have been suggested to be gamma-secretases responsible for the proteolytic cleavage of amyloid precursor protein (APP) to form amyloid-beta (A beta), a protein implicated in the development of Alzheimer's disease. Here we examined whether these presenilins are required for the generation of multiple A beta species by analyzing the production of several forms of secreted and intracellular A beta in mouse cells lacking PS1, PS2 or both proteins. Although most A beta species were abolished in PS1/PS2(-/-) cells, the production of intracellular A beta 42 generated in the endoplasmic reticulum/intermediate compartment was unaffected by the absence of these proteins, either singly or in combination. These results indicate that production of this pool of A beta occurs independently of PS1/PS2, and therefore, another gamma-secretase activity must be responsible for cleavage of APP within the early secretory compartments.

Alzheimer Disease↗

Epidural abscess causing tetraparesis: case report.

A case is presented of a 26-year-old male with a 8-day history of fever and back pain, and limb weakness beginning 24 hours before admission. An abscess caused by a staphylococcus aureus was localised in the thoracic paravertebral region with penetration in the subarachnoidal space at T1. Myelography appeared to be superior to CAT-scan and NMRI of the cervico-thoracal region in supporting the diagnosis. Treatment by laminectomy of C7-T3 48 hours after admission did not lead to neurological improvement and an incomplete tetraplegia persisted. The importance and difficulty of early diagnosis is stressed.

Abscess↗

Analysis of the 5-HT1A receptor involvement in passive avoidance in the rat.

1. The effects of the 5-HT2A/2C agonist DOB, the selective 5-HT1A agonist NDO 008 (3-dipropylamino-5-hydroxychroman), and the two enantiomers of the selective 5-HT1A agonist 8-OH-DPAT (R(+)-8-OH-DPAT and S(-)-8-OH-DPAT) were studied in a step-through passive avoidance (PA) test in the male rat. 2. The 5-HT1A agonists injected prior to training (conditioning) produced a dose-dependent impairment of PA retention when examined 24 h later. R(+)-8-OH-DPAT was four times more effective than S(-)-8-OH-DPAT to cause an impairment of PA retention. Both NDO 008 and the two enantiomers of 8-OH-DPAT induced the serotonin syndrome at the dose range that produced inhibition of the PA response, thus, indicating activation of postsynaptic 5-HT1A receptors. 3. Neither NDO 008 nor R(+)-8-OH-DPAT induced head-twitches, a behavioural response attributed to stimulation of postsynaptic 5-HT2A receptors. In contrast, DOB induced head-twitches at the 0.01 mg kg(-1) dose while a 200 times higher dose was required to produce a significant impairment of PA retention. 4. The impairment of PA retention induced by both NDO 008 and R(+)-8-OH-DPAT was fully blocked by the active S(+)- enantiomer of the selective 5-HT1A antagonist WAY 100135 and the mixed 5-HT1A/beta-adrenoceptor antagonist L(-)-alprenolol. In contrast, the mixed 5-HT2A/2C antagonists ketanserin and pirenperone were found to be ineffective. Moreover, the beta2-adrenoceptor antagonist ICI 118551, the beta-antagonist metoprolol as well as the mixed beta-adrenoceptor blocker D(+)-alprenolol all failed to modify the deficit of PA retention by NDO 008 and R(+)-8-OH-DPAT. None of the 5-HT1A or 5-HT2A/2C receptor antagonists tested or the beta-blockers altered PA retention by themselves. 5. A 3 day pretreatment procedure (200+100+100 mg kg(-1)) with the tryptophan hydroxylase inhibitor p-chlorophenylalanine (PCPA) did not alter PA retention and did not prevent the inhibitory action of the 5-HT1A agonists, indicating that their effects on PA do not depend on endogenous 5-HT. 6. The effects of NDO 008 on PA were also studied using a state-dependent learning paradigm. NDO 008 was found to produce a disruption of PA when given either prior to training or retention or both prior to training and retention but it failed to affect PA retention when given immediately after training. .7 These findings indicate that the deficit of passive avoidance retention induced by the 5-HT1A agonists is mainly a result of stimulation of postsynaptic 5-HT1A receptors but not 5-HT2A receptors. The 5-HT1A receptor stimulation appears to interfere with learning processes operating at both acquisition and retrieval.

DOM 2,5-Dimethoxy-4-Methylamphetamine↗

Psychological distress in the 5-year period after predictive testing for Huntington's disease.

The paper reports on a 5-year longitudinal study on psychological distress after predictive testing for Huntington's disease (HD) and on correlates of post-test distress. Psychometric tests and questionnaires were used. The tested persons were invited to participate in the follow-up study; the uptake rate was 75% (24 carriers, 33 non-carriers). Three time points were included: baseline, 1 year and 5 years post-test. Five years after the test, mean distress scores of both carriers and non-carriers were within the normal range. Carriers did not differ from non-carriers with regard to mean general distress. Compared to non-carriers, however, carriers had significantly less positive feelings (P<0.001) and were more consciously avoiding HD-related situations and thoughts (P<0.01). These findings reflect the carriers' conscious and unconscious attempt to escape from pessimism and to minimise negative consequences of the test result. Psychological distress 5 years post-test was significantly associated with ego-strength (P<0.05 to P<0.001). Except for intrusion and avoidance, distress was also associated with test motivation (P<0.05 to P<0.01). Compared with baseline level, mean depression, general and specific anxiety had significantly decreased 1 year and 5 years post-test (P<0.05 to 0.01). This evolution was independent of the test result. However, based on test motivation, a subgroup of tested persons having long lasting psychological distress could be identified, also irrespective of test result. Persons who asked the test to get rid of the uncertainty, without being able to specify implications for substantial life areas, had more psychological distress before and after the test than those who wanted the test for specific reasons (P<0.001 to P<0.0001). Moreover, the pattern of post-test anxiety differed over time, depending on the test motivation (P<0.05). The findings suggest that pre- and post-test counselling should pay special attention to persons with lower ego-strength and with an unspecified test motivation, because they are at higher risk for long-term psychological distress, independently of the test result.

Adaptation, Psychological↗

Screening for FMR-1 premutations in 122 older Flemish males presenting with ataxia.

Recently, Hagerman et al described the occurrence of a late-onset neurological disorder in five male carriers of the fragile-X (FMR-1) premutation. The major characteristics of this disorder, designated the Fragile-X Tremor Ataxia Syndrome (FXTAS), are progressive intention tremor, cerebellar ataxia and cognitive decline. Most cases of FXTAS published thus far were ascertained through families with a known fragile-X proband. Since cerebellar ataxia is one of the main cardinal features, we performed FMR-1 premutation screening in 122 male patients, older than 50 years, who were referred to us for testing of the spinocerebellar ataxia (SCA 1, 2, 3, 6, 7) genes and who were found to be negative. In this group of patients, we found five patients with an FMR-1 premutation. In four of them, a definite diagnosis of FXTAS could be made, based on the proposed diagnostic clinical and radiological criteria for FXTAS. In light of these figures, we recommend that FMR-1 analysis should be included in the molecular diagnostic work-up in the group of male ataxia patients older than 50 years.

Aged↗

Partners of mutation-carriers for Huntington's disease: forgotten persons?

This study focuses on psychological distress and coping strategies in partners of tested persons 5 years after predictive testing for Huntington's disease. A total of 16 carrier-couples and 17 noncarrier-couples participated in the study. Self-report questionnaires were used, assessing depression level, anxiety, intrusive and avoidance thoughts and coping strategies. Partners of carriers have as much distress as carriers, and for some distress variables even more (P<0.05-0.001). They clearly experience more psychological distress than noncarriers' partners, as expected (P<0.05-0.001). Regarding coping strategies, carriers' partners adopt more passive strategies (passive-regressive and avoiding reactions; P<0.05) and less active strategies (social support seeking and problem solving; P<0.05-0.001), compared to carriers. For both carriers and partners, the adoption of more passive strategies for coping was associated with more distress and the use of more active strategies with less distress (for carriers: P<0.05-0.001; for carriers' partners: P<0.05). The presence of children before predictive testing was an additional result-specific distress factor in carriers and their partners. In conclusion, carriers' partners have at least as much psychological distress as carriers, but partners have the tendency to draw back. The results suggest that the grief of carriers' partners may be 'disenfranchised', or not socially recognised, as if they have no right to mourn. We moreover interpreted the results referring to concepts such as anticipatory grief, psychological defences, dissonance processes and imbalanced partner relationship. Finally, we formulated some implications for genetic counselling.

Adaptation, Psychological↗

Retroviral mRNA nuclear export elements regulate protein function and virion assembly.

Rodent cells are notable for their inability to support normal assembly of HIV particles. In this report, we address possible causes for this defect by considering the hypothesis that mRNA-associated events occurring in the nucleus can regulate the activity of their encoded proteins in the cytoplasm. We show that altering the RNA nuclear export element used by HIV gag-pol mRNA from the Rev response element to the constitutive transport element restores both the trafficking of Gag to cellular membranes and efficient HIV assembly in murine cells. These results suggest that two phases of the HIV life cycle, RNA export and capsid assembly, that have hitherto been regarded as distinct are, in fact, linked. Thus, protein function and fate may depend upon the full and precise history of its encoding mRNA.

3T3 Cells↗

Detection of simulated periodontal bone gain by digital subtraction radiography with tuned-aperture computed tomography. The effect of angular disparity.

OBJECTIVES: To investigate the influence of angular disparity on observer detection of simulated bone gain in digital subtraction radiography using tuned-aperture computed tomography (TACT). MATERIALS AND METHODS: Simulated periodontal defects were created in interproximal and buccal or lingual (tooth-obscured) areas of the premolar and molar regions of a dry human skull. Radiographs were obtained before and after known weights of amorphous bone were added to the defects to simulate bone gain. The skull was positioned in a multidirectional tomographic unit to achieve reproducibility. A series of nine basis images were acquired with a CMOS intra-oral receptor and repeated using angular disparities of 10 degrees, 20 degrees, and 30 degrees. Stacks of TACT slices generated from the basis images were paired for image-registration, histogram-equalization and subtraction using TACT Workbench. Eight calibrated observers randomly assessed the presence or absence of bone gain using a 5-point confidence scale. ROC curves were generated and A(z) values were analysed using ANOVA. RESULTS: There were significant differences in the performance of the observers (P=0.034), defect location (P=0.005), amount of bone gain (P<0.001), angular disparity (P=0.003) and angular disparity x defect location interaction (P=0.019). Mean A(z) values in detecting bone gain were 0.90, 0.85, 0.79 for angular disparities of 10 degrees, 20 degrees, and 30 degrees respectively. CONCLUSIONS: Smaller angular disparity provided better detection of bone gain with TACT-subtraction using nine basis-projections. This effect of angular disparity was especially evident with tooth-obscured defects.

Alveolar Bone Loss↗