Search PubMed⌕ Search

Biomedical subjects

J Kim

Publications and source records attributed to J Kim.

At least 775 records · Page 43Linked to original sources
PubMed1997

A comparison of behavioral and educational interventions for fibromyalgia.

OBJECTIVE: To compare a comprehensive behavioral intervention with an education/control condition in the treatment of patients with fibromyalgia (FM), and to explore the role of mediators of clinical improvement in both groups. METHODS: The effects of the behavioral and education/control interventions were evaluated across a 10 week treatment period and at 6 month followup on measures of pain, depression, disability, pain behaviors, and intervening variables. The behavioral intervention focused on the development of diverse pain coping skills, while the education/control condition presented information on a range of health related topic without emphasizing skill acquisition. RESULTS: Although improvement across time was found in depression, self-reported pain behaviors, observed pain behaviors, and myalgia scores, no differences in these criteria were found between the behavioral and education/control conditions. Multiple regression analyses revealed that changes in helplessness and passive coping were associated with improvement in a number of clinical outcomes. CONCLUSION: The findings illustrate the value of psychoeducational interventions in decreasing the psychological and behavioral effect of FM, and the value of reducing dysfunctional coping and helplessness in future intervention research.

Adult↗
PubMed1997

Psychosocial factors associated with complementary treatment use in fibromyalgia.

OBJECTIVE: To examine the frequency and predictors of reported complementary treatment use in a sample of 111 subjects with fibromyalgia (FM). The perspective was adopted that complementary treatment use represents a form of medical help-seeking that may be subject to a variety of biological, social, and psychological influences. METHODS: Patients with FM were recruited from community and university based clinics and support groups throughout the greater San Diego, California, area. Patients participated in a comprehensive evaluation of their pain, psychological functioning, and disability prior to their potential involvement in a clinical trial designed to help them copy with their condition. They were also administered a rheumatological evaluation to verify their FM and a 20 item questionnaire to assess their use of complementary treatment strategies specifically for coping with FM. RESULTS: Ninety-eight percent of the sample reported the use of at least one strategy over the preceding 6 months. Exercise, bed rest, vitamins, heat treatment, and spirituality/praying were the most frequently used strategies by subjects on a daily basis. Multiple regression analysis revealed that lower age, higher pain, and higher disability were uniquely associated with higher complementary treatment use. The Pain Rating Index, a measure of the subjective severity of pain from the McGill Pain Questionnaire, proved highly significant in explaining the relationship between pain and questionnaire scores. Pain coping strategies and quality of social support did not predict complementary treatment use. CONCLUSION: The findings suggest that poor clinical status is a major predictor of complementary treatment use in FM. However, longitudinal research is recommended to clarify the relationship between clinical status and help-seeking patterns in patients with FM over time.

Adult↗
PubMed1997

An empirical study of the Health Status Questionnaire System for use in patient-computer interaction.

Patient involvement in the health care process is very important to any attempt to improve health care quality and patient satisfaction. Although many computerized medical record systems have been introduced, physicians are the only players in the process of data collection and interpretation. A computerized version of the Health Status Questionnaire has been developed to provide a simple, inexpensive method of direct patient entry into the medical record. The system philosophy emphasizes user-centered design and an empirical study was conducted with one hundred twelve outpatients to evaluate the interface aspects of the system as well as the hardware preference of the patients. Statistical analysis indicate that the patients involved in the study rated the user interface of the Health Status Questionnaire System highly. The study also revealed that a considerable number of the general population still have negative preconceptions about their ability to handle a computer or similar looking machinery. When they were asked to use a desktop computer with a mouse, 26 out of 50 patients refused, while 61 out of 62 agreed to use a hand-held pen computer.

Attitude to Computers↗
PubMed1996

G.A and U.U mismatches can stabilize RNA internal loops of three nucleotides.

Optical melting experiments on oligoribonucleotides containing internal loops of three nucleotides (two nucleotides opposing one nucleotide) flanked by CG pairs show that the free energy of internal loop formation depends on the sequence of nucleotides within the loop. Internal loops with the potential for A.G and U.U mismatch pairing generally have more favorable free energies of formation than internal loops with potential AA, CC, AC, or UC pairings. In most cases, potential A.G and U.U pairings leaving a single unpaired nucleotide 5' to a flanking CG pair are most stable; those leaving a single nucleotide 3' to a flanking CG pair have intermediate stability. Internal loops of three nucleotides without potential A.G or U.U pairs are the least stable. The results provide an improved model for predicting the folding stabilities of internal loops of three nucleotides.

Adenine↗
PubMed1996

A neutralization site of DA strain of Theiler's murine encephalomyelitis virus important for disease phenotype.

DA strain of TMEV induces a chronic, persistent, demyelinating disease in SJL/J weanling mice, while inoculation with GDVII strain of TMEV induces an acute, lethal neurovirulent disease. We show that three amino acids in the DA EF loop-DAV P2 141 Lys, 143 Gly, and 173 Thr-are part of a neutralization site of DA monoclonal antibody (mAb), DAmAb1. DA virus with a mutation of VP2 143 from Gly to Asp, like wild-type virus, persists 6 weeks postinfection (PI) and produces white matter disease. DA virus with a mutation of VP2 141 from Lys to Asn persists but does not induce significant white matter disease. DA virus with a mutation of DA VP2 173 from Thr to Phe fails to persist or to induce significant white matter disease. The diversity and complexity of the mutant virus-induced disease phenotype presumably reflects the varied effects of the mutated amino acid residues on the three-dimensional structure of the viral capsid. The localization of DA VP2 141 and VP2 173 near the putative receptor binding region of the virus suggest that a disruption of interactions between the virus and its receptor is important in the late demyelinating disease and for virus neutralization.

Animals↗
PubMed1996

Nitrato(2,3,7,8,12,13,17,18-octaethylporphyrinato)iron(III).

The crystal structure of [Fe(C36H44N4)(NO3)] has been determined in the space group P1. The unit cell contains two molecules. The Fe atom is displaced out of the porphyrin plane by 0.50 A, the average Fe-Np distance is 2.056 (1) A (where Np is a porphyrin N atom) and the Fe-O(NO3) bond length is 2.016 (3) A.

Crystallography, X-Ray↗
PubMed1996

Assembly, specific binding, and crystallization of a human TCR-alphabeta with an antigenic Tax peptide from human T lymphotropic virus type 1 and the class I MHC molecule HLA-A2.

T lymphocytes use TCR-alphabeta to bind and to recognize complexes of antigenic peptides bound to MHC proteins located at the surface of APCs. We have assembled and crystallized this intercellular complex of TCR/peptide/MHC from soluble human TCR-alphabeta and soluble peptide/HLA-A2 complexes. The soluble TCR-alphabeta binds specifically to its in vivo ligand, the complex of HLA-A2, and a peptide from the Tax protein of human T lymphotropic virus type 1. The soluble TCR also binds in vitro to an altered peptide ligand, which appears to be a partial agonist in T cell assays as determined by its ability to elicit different cytolytic and lymphokine secretion responses. Heterodimerization and the antigenic specificity of the TCR do not require its interchain disulfide bond, transmembrane segments, or glycosylations. Crystals of the TCR/peptide/HLA-A2 complex diffract x-rays, providing the means to study in atomic detail the mechanism of Ag-specific cell-cell recognition between T cells and target cells.

Amino Acid Sequence↗
PubMed1996

Calexcitin: a signaling protein that binds calcium and GTP, inhibits potassium channels, and enhances membrane excitability.

A previously uncharacterized 22-kDa Ca(2+)-binding protein that also binds guanosine nucleotides was characterized, cloned, and analyzed by electrophysiological techniques. The cloned protein, calexcitin, contains two EF-hands and also has homology with GTP-binding proteins in the ADP ribosylation factor family. In addition to binding two molecules of Ca2+, calexcitin bound GTP and possessed GTPase activity. Calexictin is also a high affinity substrate for protein kinase C. Application of calexcitin to the inner surface of inside-out patches of human fibroblast membranes, in the presence of Ca2+ and the absence of endogenous Ca2+/calmodulin kinase type II or protein kinase C activity, reduced the mean open time and mean open probability of 115 +/- 6 pS K+ channels. Calexcitin thus appears to directly regulate K+ channels. When microinjected into molluscan neurons or rabbit cerebellar Purkinje cell dendrites, calexcitin was highly effective in enhancing membrane excitability. Because calexcitin translocates to the cell membrane after phosphorylation, calexcitin could serve as a Ca(2+)-activated signaling molecule that increases cellular excitability, which would in turn increase Ca2+ influx through the membrane. This is also the first known instance of a GTP-binding protein that binds Ca2+.

Amino Acid Sequence↗
PubMed1996

In simple synthetic promoters YY1-induced DNA bending is important in transcription activation and repression.

Depending on promoter context, YY1 can activate or repress transcription, or provide a site for transcription initiation. To investigate whether the ability of YY1 to induce DNA bending influenced its ability to activate and repress transcription, simple synthetic promoters were constructed in which the YY1 binding site was inserted between the TATA box and either the NF1 or AP1 recognition sequences. In transient transfections of COS cells, the NF1YY1TATA and NF1RYY1TATA promoters exhibited a dramatic 15-20-fold increase in correctly initiated transcription. These promoters exhibited even larger 60-80-fold increases in transcription in HeLa cells. Neither multiple copies of the YY1 binding site alone, nor placement of a YY1 site upstream of the NF1 site activated transcription. Deletion of 4 bp between the NF1 and YY1 sites, which changes the phase of the DNA bends, abolished the 16-fold activation of transcription by NF1YY1TATA. Insertion of the YY1 site between the AP1 site and the TATA box decreased transcription approximately 3-fold. Replacing the YY1 binding site with an intrinsic DNA bending sequence mimicked this transcription repression. Sequences of similar length which do not bend DNA fail to repress AP1-mediated transcription. Gel mobility shift assays were used to show that binding of YY1 to its recognition sequence did not repress binding of AP1 to its recognition sequences. Our data indicate that YY1-induced DNA bending may activate and repress transcription by changing the spatial relationships between transcription activators and components of the basal transcription apparatus.

Animals↗
PubMed1996

Thermodynamics of coaxially stacked helixes with GA and CC mismatches.

The thermodynamics of RNA helix-helix interfaces with intervening single- and tandem-GA or single-CC mismatches were studied by UV melting experiments. The model system consists of a hairpin with a four- or five-nucleotide 5' overhang which is bound by a short oligomer, creating the helical interface. Single GA interfaces are found to have favorable free energy increments of about 2 kcal/mol. This is similar to those reported for coaxially stacked flush interfaces of AU base pairs [Walter A. E., & Turner, D. H. (1994) Biochemistry 33, 12715-12719]. The free energy increment of the GA mismatches depends little on the sequence of the closing base pairs of the helixes, whether the break in the phosphate backbone is 5' or 3' with respect to the mismatch or whether the chains are extended beyond the helix-helix interface. Surprisingly, interfaces with single-CC mismatches have favorable free energy increments similar to those of GA interfaces, even though CC mismatches in coaxial stacks occur much less frequently in known RNA secondary structures. The results provide experimental support for the assumption that a bonus free energy is required for coaxially stacked helixes with intervening GA mismatches when free energy minimization is used to predict RNA secondary structures.

Base Composition↗
PubMed1996

DNA bending between upstream activator sequences increases transcriptional synergy.

To determine if DNA bending enhances transcriptional synergy between tandem upstream activators, we constructed a series of synthetic promoters containing either an AP1 or an NF1 site linked to four copies of the putative transcription factor binding site ACGTGA incorporated into an intrinsic DNA bending sequence. In transient transfection, the intrinsic bending sequence between AP1 and the TATA box or between NF1 and the TATA box elicited a strong synergistic activation of transcription. The synergistic activation of transcription was greatly reduced when the intrinsic bending sequence was replaced with a mutant sequence which retains the binding site, but does not bend the DNA, and when the intrinsic bending sequence was upstream of the AP1 or NF1 sites. These data indicate that bent DNA located between upstream activator sequences can facilitate transcriptional synergism between bound activators.

Animals↗
PubMed1996

Effect of morphine on proopiomelanocortin gene expression and peptide levels in the hypothalamus.

Opiates have been reported to suppress POMC in the medial basal hypothalamus (MBH) but studies have been complicated by the fact that acutely, in the rat, opiates stimulate corticosterone and inhibit gonadal steroid release, which could both affect POMC in brain. We have therefore examined POMC gene expression and peptide levels in the MBH of castrated rats after 10 days of treatment with subcutaneous morphine or placebo pellets and after pellet removal. POMC mRNA was measured by solution hybridization assay and beta-endorphin (beta-EP) and alpha-MSH were measured by RIA. In castrated male rats, the mean POMC mRNA concentration in the MBH was 1.67 +/- 0.11 pg/microgram RNA in the control animals and decreased to 1.17 +/- 0.11 pg/microgram RNA in the morphine-treated animals (P < 0.01). Similarly in castrated, estradiol replaced female rats, the mean POMC mRNA level in the MBH was 1.36 +/- 0.19 pg/microgram RNA and decreased to 0.82 +/- 0.08 pg/microgram RNA after morphine treatment (P < 0.05). beta-EP levels were not significantly different in either study. When castrated male rats were similarly morphine pelleted and killed either on day 10 or 2 days later after pellet removal, the mean POMC mRNA level again fell from 1.83 +/- 0.21 in the controls to 1.28 +/- 0.20 pg/microgram RNA after 10 days of morphine; 2 days after pellet removal levels remained suppressed at 0.80 +/- 0.08 pg/microgram RNA (P < 0.01). In this study the concentrations of beta-EP and alpha-MSH were both noted to decline in the MBH after morphine treatment (P < 0.05). When the forms of beta-EP in the MBH were characterized by HPLC, a decrease in the concentration of beta-EP was again seen after morphine but no significant differences in the pattern of beta-EP processing or in the relative amounts of beta-EP1-31 compared to beta-EP1-27 and beta-EP1-26 were noted in morphine-treated animals. There was also no significant effect of 10(-6)-10(-4) M morphine on basal or KCl-stimulated release of beta-EP or gamma 3-MSH release from the perifused rat hypothalamus in vitro. We conclude that morphine suppresses POMC gene expression in the hypothalamus of chronically treated male and female rats. Persistent changes were also noted during morphine withdrawal. In some cases this was accompanied by a fall in beta-EP peptide content. These effects were seen in castrated animals with and without sex steroid replacement and are thus independent of the effects of morphine on the pituitary-gonadal axis. These results show that opiate drugs modify endogenous opioid systems in the brain and provide further support for the hypothesis that such changes may contribute to mechanisms of opiate dependence and withdrawal.

Animals↗
PubMed1996

Expression of normal and mutant huntingtin in the developing brain.

Huntington's disease (HD) is caused by a genetic mutation that results in a polyglutamine expansion in huntingtin. The time course of neuronal loss in the HD striatum and other affected brain regions before the onset of symptoms is unknown. To determine the potential influence of huntingtin on brain development, we examined its expression in the developing mouse and in human control and HD brain. By Western blot, huntingtin was detected throughout the adult mouse brain and at all stages of embryonic and postnatal brain development. The protein increased significantly between postnatal day 7 (P7) and P15, which marks a period of active neuronal differentiation and enhanced sensitivity to excitotoxic injury in the rodent striatum. Immunoreactivity was found in neurons throughout the brain and localized mostly to the somatodendritic cytoplasm and to axons in fiber bundles. Staining was variable in different groups of neurons and within the same cell population. In developing brain, huntingtin was limited primarily to neuronal perikarya. Increased immunoreactivity in large neurons followed the gradient of neurogenesis and appeared in the basal forebrain and brainstem by embryonic days 15-17, in regions of cortex by P0-P1, and in the striatum by P7. In human brain at midgestation (19-21 weeks), huntingtin was detected in all regions. The brain of a 10-week-old infant with the expanded HD allele expressed a higher molecular weight mutant form of huntingtin at levels comparable to those of the wild-type protein. Thus, mutant huntingtin is expressed before neuronal maturation is complete. Results suggest that huntingtin has an important constitutive role in neurons during brain development, that heterogeneity in neuronal expression of the protein is developmentally regulated, and that the intraneuronal distribution of huntingtin increases in parallel with neuronal maturation. The presence of mutant huntingtin in the immature HD brain raises the possibility that neurons may be affected during brain development and possibly in the postnatal period when vulnerability to excitotoxic injury is at its peak.

Animals↗
PubMed1996

Site-directed mutagenesis of the human adenosine A2A receptor. Critical involvement of Glu13 in agonist recognition.

A glutamic acid residue in the first transmembrane domain of the human adenosine A2A receptor was mutated to glutamine. Radioligand binding studies on COS-7 cell membranes expressing either the wild-type or the mutant receptor revealed that the affinity of the prototypic agonist CGS21680 (2-[4-[(2-carboxyethyl)phenyl]ethylamino]-5'-N-ethylcarboxamidoadenosine ) for the mutant receptor was 15-fold lower than for the wild-type receptor. This was confirmed in functional studies with intact cells. The EC50 values of CGS21680 for the stimulation of cAMP production differed in a similar way. Antagonists of various chemical structure were equally effective on both mutant and wild-type receptors, thus the mutation selectively diminishes agonist affinity. We propose an indirect perturbation of the binding site, perhaps through a proton transfer mechanism as suggested by molecular modelling.

Cyclic AMP↗
PubMed1996

Recent amplification of rat ID sequences.

The rodent identifier (ID) family of repeats has amplified at an extremely high rate in the rat genome in recent evolutionary time, resulting in 130,000 copies per haploid genome. Statistical analyses support the grouping of 119 individual rat ID elements into four major and three minor subfamilies based on six diagnostic nucleotide positions. The consensus sequence of the oldest subfamily is identical to the ID region of the rat BC1 RNA gene, suggesting that the BC1 gene has dominated the early amplification of rat ID elements. The other six subfamilies share at least one diagnostic mutation in relation to the BC1 gene and show much less nucleotide sequence divergence, indicating that the recent large amplification of rat ID elements has been driven by another lineage of master gene(s) in the rat genome. This is consistent with the formation of a new lineage of master elements for ID amplification in rat. The formation of most rat ID elements appears to have occurred during the past three million years based on the results that four out of five randomly chosen ID elements are present only in the genome of one rat species and not in other closely related species.

Animals↗