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 1,405 records · Page 78Linked to original sources

CD4-independent utilization of the CXCR4 chemokine receptor by HIV-1 and HIV-2.

HIV entry is mediated by an interaction between CD4 and members of the chemokine receptor family of proteins. It is likely that CD4 induces conformational changes in the viral envelope glycoproteins that facilitate a subsequent interaction with the chemokine receptor. To understand these events, variants of HIV-2 and HIV-1 have been derived that are able to interact directly with CXCR4 in the absence of CD4. One HIV-2 variant. termed HIV-2/vcp, has an expanded host range that includes CXCR4+/CD4- lymphoid and nonlymphoid cell lines. In contrast to T-tropic isolates of HIV-1, HIV-2/vcp was shown to induce > 95% downregulation of CXCR4 on chronically infected cells and was able to superinfect HIV-1-infected cells. A variant of HIV-1/IIIB termed HIV-1/IIIBx was also derived that is both replication competent and fusogenic for a CD4-negative subclone of SupT1 cells, termed BC7. Infection of BC7 cells by HIV-1/IIIBx was resistant to anti-CD4 monoclonal antibodies but inhibited by the anti-CXCR4 mAb, 12G5. HIV-1/IIIBx was highly fusogenic on 3T3 cells expressing CXCR4 in the absence of CD4. In contrast to HIV-2/vcp, the host range of HIV-1/IIIBx was highly restricted and replication in several CD4+/CXCR4+ lymphoid cell lines was reduced compared to HIV-1/IIIB. In addition, HIV-1/IIIBx failed to downregulate CXCR4 on chronically infected cells. These studies indicate that HIV-1 and HIV-2 variants can be derived in vitro that utilize CXCR4 in the absence of CD4. Although the mechanism(s) for these changes remain unclear, possibilities include an increased avidity of the viral envelope glycoprotein for CXCR4 and/or the increased exposure of the chemokine receptor binding site. Further biochemical and molecular analysis of the envelope glycoproteins from these viruses should be helpful in addressing these and other possibilities.

Animals↗

Leu-3+ lymphocytes account for increased CSF cellularity.

Inflammatory conditions of the central nervous system (CNS) are often marked by an increase in lymphocyte number in the cerebrospinal fluid (CSF). In order to determine if changes in CSF cell numbers can alter T-lymphocyte subset composition in CSF or in blood, cell surface markers were evaluated in 25 CSF and paired blood samples from a variety of neurologically affected patients. T-cell subset levels in peripheral blood did not reflect subset levels in paired CSF samples. However, CSF samples with elevated cell numbers (greater than 3 cells/mm3) had significantly increased levels of Leu-3+ T-cells (P less than 0.001), but not Leu-2+ T-cells relative to CSF samples with low cell counts. These data suggest a selective increase in the Leu-3+ T-lymphocyte subset in CSFs with increased cellularity in patients with acute neurologic signs.

Antigens, Differentiation, T-Lymphocyte↗

Effects of electrical stimulation or lesion in nucleus accumbens on the behaviour of rats in a T-maze after administration of 8-OH-DPAT or vehicle.

Electrical brain stimulation may be a therapeutic alternative for irreversible lesions in treatment-resistant patients with obsessive-compulsive disorder (OCD). We compared the effects of electrical stimulation and lesion in the nucleus accumbens (n acc) on the behaviour of rats in a model for OCD. Rats were tested for spontaneous alternation behaviour (AB) in a T-maze and assigned to four groups: an electrode implant group with stimulation 'ON' (stimON) or 'OFF' (stimOFF), a lesion or a sham group. Postoperatively, the number of arm visits and AB were tested after 8-hydroxy-2-(di-n-propylamino)-tetralin hydrobromide (8-OH-DPAT; 2 mg/kg) or saline administration. After 8-OH-DPAT administration, more arm visits were counted in the stimON (92.2%) and lesion groups (79.3%) than in both control groups (stimOFF 54.2; sham 61.2%). AB was significantly decreased in the stimON (10.5%) and lesion groups (10.2%) relative to the sham (22.0%) but not to the stimOFF group (14.7%). After saline administration, rats performed more arm visits in the stimON (81.5% non-significant) and lesion groups (93.6% significant) relative to the stimOFF (70.8%) and the sham groups (74.5%). No significant differences, however, were observed for AB. In conclusion, both treatments resulted in a decreased AB after 8-OH-DPAT administration (modelling an increase in compulsions) and more arm visits.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

Binding affinity of sarpogrelate to 5-HT(2A) receptor ligand recognition sites in rat renal cortical and mesangial cells in culture.

We detected specific binding of 3H-ketanserin (0.6 nM) in rat renal cortical membrane preparations (4.70 +/- 0.57 fmol/mg protein) and mesangial cells (7.55 +/- 0.92 fmole/10(6) cells). Thus, the value in the renal cortical membrane corresponded to 15% of that in the cerebral cortical membranes (30.0 +/- 2.9 fmole/mg protein). The affinity of 3H-ketanserin binding displacement activities by sarpogrelate, a selective 5-HT2A receptor antagonist, in the renal cortical membrane (IC50; 0.448 +/- 0.061 microM) and mesangial cells (IC50; 0.656 +/- 0.187 microM) were almost 100-fold less than that in the cerebral cortical membrane (IC50; 4.62 +/- 1.02 nM). In the renal cortical membranes and mesangial cells, methysergide displaced a tiny fraction of 3H-ketanserin binding at concentrations up to 10 microM. These results did not explain the functional activity of 5-HT in the mesangial cells, and we conclude that specific 3H-ketanserin binding sites in the mesangial cells consisted of methysergide-resistant and non-serotonergic sites with low affinity for sarpogrelate.

DOM 2,5-Dimethoxy-4-Methylamphetamine↗

Expression of multiple functional chemokine receptors and monocyte chemoattractant protein-1 in human neurons.

Functional chemokine receptors and chemokines are expressed by glial cells within the CNS, though relatively little is known about the patterns of neuronal chemokine receptor expression and function. We developed monoclonal antibodies to the CCR1, CCR2, CCR3, CCR6, CXCR2, CXCR3 and CXCR4 chemokine receptors to study their expression in human fetal neurons cultured from brain tissue as well as the clonally derived NT2.N human neuronal cell line (NTera 2/cl.D1). Specific monoclonal antibody labeling demonstrated expression of CCR2, CXCR2, CXCR3 and CXCR4 on neurons from both sources. Co-labeling studies revealed strong expression of CXCR3 and CXCR4 on both dendritic and axonal processes, with a weaker expression of CXCR2 and CCR2. Reverse transcriptase-polymerase chain reaction analysis of pure NT2.N neurons confirmed RNA expression for CCR2, CXCR2, CXCR3 and CXCR4. No changes in the neuronal labeling pattern of chemokine receptor expression were noted when NT2.N neurons were grown on a supporting layer of astrocytes, again consistent with similar patterns seen in primary human fetal brain cultures. Analysis of single-cell calcium transients revealed a robust response to stromal derived factor-1alpha (CXCR4) and melanocyte growth-stimulating activity (CXCR2), and variable response to monocyte chemoattractant protein-1 (CCR2) or interferon-gamma inducible protein-10 (CXCR3). Finally, we detected the release of monocyte chemoattractant protein-1 from pure cultures of NT2.N neurons, but not undifferentiated NT2 cells. These data indicate that individual neurons may not only co-express multiple functional chemokine receptors, but also that neurons themselves produce chemokines which may influence cellular function within the central nervous system.

Astrocytes↗

Cross-protection between Actinobacillus pleuropneumoniae biotypes-serotypes in pigs.

Four groups of hysterectomy-derived and colostrum-deprived pigs were intranasally inoculated with an Actinobacillus pleuropneumoniae biotype 1-serotype 2 strain (producing RTX toxins ApxII and ApxIII. 6 pigs), an A. pleuropneumoniae biotype 1-serotype 10 strain (producing ApxI. 5 pigs), an A. pleuropneumoniae biotype 2-serotype 2 strain (producing ApxII, 5 pigs) or saline (controls, 7 pigs). All pigs were exposed to A. pleuropneumoniae biotype 1-serotype 2 endobronchial challenge. After challenge, severe clinical signs were observed in all control pigs, one pig immunized with the A. pleuropneumoniae biotype 1-serotype 10 strain and two pigs immunized with the A. pleuropneumoniae biotype 2-serotype 2 strain. These pigs died within 36 h after challenge and 20 to 50% of the lungs were macroscopically affected. In the other pigs, clinical signs were mild or absent and no or only small, focal lung lesions were observed when euthanized at 48 h after challenge. At the time challenge neutralizing antibodies against ApxI only. ApxII only and both ApxII and III were present in sera of pigs immunized with the A. pleuropneumoniae biotype 1-serotype 10 strain, the A. pleuropneumoniae biotype 2-serotype 2 strain and the A. pleuropneumoniae biotype 1-serotype 2 strain, respectively. These results indicate that immune mechanisms other than Apx neutralizing antibodies were involved in partial cross-protection of pigs immunized against A. pleuropneumoniae biotype 1-serotype 10 and challenged with the A. pleuropneumoniae biotype 1-serotype 2.

Actinobacillus Infections↗

Variations in occurrences of nutrition-related diseases in Sub-Saharan Africans in stages of transition: what of the future?

In many Sub-Saharan African populations, in particular urban dwellers, there have been marked rises in the prevalences of obesity in women, hypertension, diabetes, and cerebral vascular disease. Yet there have been only slight rises in coronary heart disease. To learn more of the roles of the various influencing factors in the puzzling situations described, some aspects of the past and present occurrences of these diseases are described and discussed, with comparisons being made with corresponding situations in African Americans, as well as in certain white populations. Despite increases in the knowledge of influencing factors, such fail to explain fully the epidemiologic situations described. As to the future, judging from the experiences of other populations, despite continuing indigence, within the next generation significant rises in coronary heart disease in certain African populations seem to be inevitable. However, in many of those populations, in particular those in the South, the extent of changes, apart from those linked with level of socioeconomic state, will be strongly affected by the rising epidemic of human immunodeficiency virus and acquired immunodeficiency syndrome.

Africa South of the Sahara↗

Unusual visualization of an adrenal carcinoma on NP-59 scintiscan.

[Iodine-131]6-beta-iodomethylnorcholesterol (NP-59) visualization of adrenocortical carcinoma is unusual. We describe a 17-year-old female with virilization and elevated plasma testosterone, dehydroepiandrosterone sulfate (DHEAS) and aldosterone. Magnetic resonance imaging disclosed a 9-cm right adrenal mass. NP-59 adrenal scanning displayed unilateral uptake of tracer and no visualization of the contralateral adrenal gland. Exploratory laparotomy revealed adrenocortical carcinoma. Subsequent immunohistochemical studies confirmed that the tumor was capable of producing a mixture of steroids, including testosterone, DHEAS and aldosterone. Visualization of an adrenal tumor on NP-59 scintiscan is an unusual finding, which cannot exclude the possibility of malignancy.

Adolescent↗

Secondary supratentorial anaplastic astrocytoma following treatment of medulloblastoma.

The development of secondary tumours is a rare but well known late effect of radiation therapy of lesions in the central nervous system. Most radiation-induced tumours are of mesenchymal origin, but on rare occasions gliomas can occur. We describe a patient in whom a supratentorial anaplastic astrocytoma developed 15 years after surgery and radiotherapy for a childhood posterior fossa medulloblastoma. A concise review of the pertinent literature is given.

Astrocytoma↗

Torque variations during repeated passive isokinetic movements of the knee in subjects with Parkinson's disease and healthy control subjects.

The purpose of this study was to quantify response variations during isokinetic passive movements of the knee in subjects with Parkinson's disease. Parkinsonian patients demonstrated a greater decrease of resistive torque compared to healthy control subjects, particularly in tests at higher velocities and during knee flexion movements. Responses were influenced by electromyographic activity in stretched and shortened muscle groups and also by mechanical factors. The results indicate that repetition of movements needs to be taken into account when measuring hypertonia in parkinsonian subjects.

Journal Article↗

Opportunities and challenges in targeting HIV entry.

Characterization of the mechanisms by which HIV-1 enters cells has allowed for an increased understanding of not only tropism and pathogenesis, but also the identification of new targets for rational drug design. Several classes of HIV-1 entry inhibitors have been developed. Antagonists targeting the interaction of the viral envelope protein and receptors on the cell surface, as well as peptides that target an intermediate in the fusion process, have shown promise in vitro and are currently being evaluated in clinical trials. The addition of entry inhibitors to current drug regimens has the potential to significantly improve the therapeutic options for infected individuals, which is crucial for those resistant to or failing currently available therapies.

Attachment Sites, Microbiological↗

Stable secretion of a soluble, oligomeric form of rabies virus glycoprotein: influence of N-glycan processing on secretion.

Rabies virus glycoprotein (RGP) is a 505 amino acid type I transmembrane glycoprotein that is important in the pathogenesis of rabies virus infection. RGP also stimulates the development of neutralizing antibodies by the host. N-linked glycosylation is required for both cell surface expression and immunogenicity of RGP. In the current study, a soluble form of RGP, constructed by insertion of a stop codon external to the transmembrane domain, was expressed in transfected Chinese hamster ovary cells. The soluble form of RGP was found to be appropriately antigenic and immunogenic. Similar to full-length RGP, the soluble form was assembled into homodimers and homotrimers. Core glycosylation was required for secretion of soluble RGP and cell surface expression of full-length RGP. In addition, initial glucose trimming of the N-glycans was necessary and sufficient for secretion of soluble RGP and cell surface expression of full-length RGP. Further N-glycan processing was not required for secretion or cell surface expression of soluble or full-length RGP, respectively.

Animals↗

Glu11 site cleavage and N-terminally truncated A beta production upon BACE overexpression.

Amyloid beta peptides (A beta) are generated by the proteolytic processing of the amyloid beta precursor protein (APP). The newly identified beta-site APP-cleaving enzyme (BACE) cleaves APP at Asp1 as well as between Tyr10 and Glu11 of A beta, producing C-terminal fragments (CTFs) C99 and C89, respectively. Subsequent cleavage by gamma-secretase gives rise to A beta 1-40/42 and A beta 11-40/42. Although both full-length and A beta peptides truncated at residue 11 have been identified in amyloid plaques in the AD brain, the relative proportion of these two cleavage products produced by BACE and secreted into the medium by cultured cells is unknown. Using cell lines stably overexpressing BACE, we found that A beta 11-40 and A beta 11-42 are major A beta cleavage products generated by BACE. We further showed that BACE utilizes both full-length APP as well as C99 as substrates for the production of C89, and that A beta 11-40/42 can be generated by sequential cleavage of single APP molecules by BACE and gamma-secretase. Taken together, the abundance of A beta 11-40/42 produced by BACE suggests that their roles in AD pathogenesis may be underestimated.

Amyloid Precursor Protein Secretases↗

Presenilin modulates Pen-2 levels posttranslationally by protecting it from proteasomal degradation.

The gamma-secretase complex functions to cleave several type I transmembrane proteins within their transmembrane domains. These include the amyloid precursor protein, which is central to Alzheimer's disease pathogenesis, as well as N-cadherin and Notch, which regulate transcription. This complex is composed of four requisite integral membrane proteins: presenilin 1 (PS1) or presenilin 2 (PS2), nicastrin, Pen-2, and Aph-1. How these proteins coordinately regulate one another and assemble to form a functional complex is not well understood. In this report we demonstrate that PS1 selectively enhances the stability of Pen-2 protein but not that of nicastrin or Aph-1. In the absence of PS1, Pen-2 was rapidly degraded by the proteasome. As PS1 levels increased, so too did the half-life of Pen-2 and therefore its steady-state levels. In addition, Pen-2 protein levels correlated with PS1 levels not only in cell culture but in transgenic mouse models as well. The genetic absence of PS1 and PS2, and therefore of gamma-secretase-dependent mediation of transcriptional activity, did not affect Pen-2 mRNA levels. Rather, presenilin (PS) regulates Pen-2 levels posttranslationally by preventing its degradation by the proteasome. Thus, the amount of Pen-2 protein is effectively titrated by its PS binding partner, and the rapidity with which Pen-2 is degraded in the absence of PS interactions could provide a mechanism to tightly regulate gamma-secretase complex assembly.

Alzheimer Disease↗