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Biomedical subjects

J Ling

Publications and source records attributed to J Ling.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Anatomical and functional studies on surgical and non-surgical treatment of mandibular condylar process fractures].

OBJECTIVE: This study aim at comparing anatomical and functional recovery from surgical and non-surgical treatment of condylar process fractures. METHODS: Totally Forty-nine patients, 22 treated by performing operation, and 27 using non-surgical methods, were included in this study. Displaced angle of condylar, maximal mouth opening, lateral deviation on opening and masticatory function were analyzed using radiological and clinical examinations 6 weeks and 1 year after treatment. RESULTS: Patients treated by surgical method had significantly greater initial displaced angle of condyles than did the group treated non-surgically, but patients treated non-surgically had significantly greater displaced angle of condylar and lateral deviation on opening than did the group treated surgically 6 weeks and 1 year after the therapy finished. Patients treated surgically had significantly greater masticatory function than did the group treated non-surgically 6 weeks and 1 year after treatment. Six weeks later, patients treated surgically had significantly greater maximal mouth opening than did the group treated non-surgically. CONCLUSION: Surgical treatment may be helpful in anatomical and functional recovery of mandibular condyles for patients with displaced condylar process fractures.

Adult↗
PubMed2001

[The role of Fos protein in modulation of dental pain in central nerve system].

OBJECTIVE: The aims of this study were to reveal the relationship between Fos protein expression, the transcription of preproenkephalin (PENK) mRNA, and the change of enkephalin (ENK) level initiated by experimental dental pain, and to understand the central modulation mechanism of dental pain. METHODS: The techniques of Immunohistochemistry in situ hybridization and radioimmunoassay were applied respectively to detect the expression of Fos, the transcription of PENK mRNA, and the change of ENK level in the experimental nucleus of the spinal tract of the trigeminal nerve, caudal part (sp5c) of rats. RESULTS: It was found that Fos protein expression was in a time-dependent manner. Fos appeared half hour after the pain stimulation, and its peak occurred two hours after the pain stimulation, but disappeared slowly four hours later. The transcription of PENK mRNA was seen two hours after the pain stimulation, its peak appeared four hours later and it disappeared eight hours later. The level of ENK increased significantly (P < 0.01) in the caudal part of the spinal tract of the trigeminal nerve four hours after pain stimulation. CONCLUSION: Fos protein may take a part in the central modulation of dental pain by initiating PENK mRNA transcription which led to the increment of ENK.

Animals↗
PubMed2000

Stable and unstable transgene integration sites in the human genome: extinction of the Green Fluorescent Protein transgene in K562 cells.

In gene transfer experiments including gene therapy studies, expression of the integrated transgenes in host cells often declines with time. The molecular basis of this phenomenon is not clearly understood. We have used the Green Fluorescent Protein (GFP) gene as both a selectable marker and a reporter to study long-term transgene integration and expression in K562 cells. Cells transfected with plasmids containing the GFP gene coupled to the HS2 or HS3 enhancer of the human beta-globin Locus Control Region (LCR) or the cytomegalovirus (CMV) enhancer were sorted by either fluorescence-activated-cell-sorting (FACS) alone or FACS combined with drug selection based on a co-integrated drug resistance gene. The two groups of selected cells were subsequently cultured for long periods up to 250 cell generations. Comparison of long-term GFP transgene integration and expression in these two groups of cells revealed that the K562 genome contains two types of transgene integration sites: i) abundant unstable sites that permit transcription but not long-term integration of the transgenes and thus eliminate the transgenes in 60-250 cell generations and ii) rare stable sites that permit both efficient transcription and long-term stable integration of the transgenes for at least 200 cell generations. Our results indicate that extinction of GFP expression with time is due at least in part to elimination of the gene from the host genome and not entirely to transcriptional silencing of the gene. However, long-term, stable expression of the transgene can be achieved in cells containing the transgene integrated into the rare, stable host sites.

Binding Sites↗
PubMed2000

The role of 5'-leader length, secondary structure and PABP concentration on cap and poly(A) tail function during translation in Xenopus oocytes.

The 5'-cap structure and poly(A) tail of eukaryotic mRNAs function synergistically to promote translation initiation through a physical interaction between the proteins that bind to these regulatory elements. In this study, we have examined the effect of leader length and the presence of secondary structure on the translational competence and the function of the cap and poly(A) tail for mRNAs microinjected into Xenopus oocytes. Increasing the length of the 5'-leader from 17 to 144 nt resulted in a 2- to 4-fold increase in expression from an mRNA containing an unstructured leader but increased expression up to 20-fold for an mRNA containing 5'-proximal structure. Consequently, the presence of secondary structure was less inhibitory for those mRNAs with a longer 5'-leader. Co-injection of poly(A)-binding protein (PABP) mRNA increased the function of the cap and poly(A) tail in promoting translation from poly(A)(+) but not poly(A)(-) mRNAs, particularly for mRNAs containing secondary structure. In the absence of an internal ribosome entry site, expression from the distal cistron of a dicistronic mRNA increased as a function of the length of the intercistronic region and the concentration of PABP. The inhibitory effect of intercistronic located secondary structure on translation was position-dependent. Indeed, the effect of secondary structure was abolished if positioned 134 nt upstream of the distal cistron. These data suggest that the length of a leader, the presence of secondary structure and the concentration of PABP determine the extent to which the cap and poly(A) tail regulate translation.

5' Untranslated Regions↗
PubMed2000

Stability of a varicella-zoster virus glycoprotein E epitope.

The epitope stability of a varicella-zoster virus (VZV) glycoprotein E (gE) was analyzed with monoclonal antibodies (mAbs) in cells infected with different passages of various VZV strains and isolates. The gE-specific mAbs recognized same antigenic sites (epitopes) in VZV isolates with various passage history. All VZV strains and virus-isolates reacted with an anti-gE monoclonal antibody by immunoprecipitation, or indirect fluorescent antibody staining test. Sera from VZV seropositive individuals reacted with a truncated VZV gE glycoprotein, designated TgpI-511. Also, human mononuclear cells (MNCs) stimulated with TgpI-511 glycoprotein were shown to produce VZV-specific antibodies in vitro. The results demonstrated the stability of these gE epitopes tested in this study in TgpI-511 and among the VZV-isolates obtained from different passages. These results also suggest that VZV glycoproteins as well as live attenuated or killed varicella vaccines containing these epitopes could be used as therapeutic booster vaccines in adults and the elderly to prevent zoster.

Adolescent↗
PubMed2000

Rethinking patient satisfaction: patient experiences of an open access flexible sigmoidoscopy service.

The high morbidity and mortality rates for colo-rectal cancer in Teesside, UK, have led to the initiation of an open access service in two local National Health Service Trust hospitals. This paper reports the results of a pilot patient satisfaction study of the service using a combination of participant-observation, in-depth interviews and questionnaire methods. Although offering a standardised service, ethnographic study revealed interesting differences in practice and follow-up procedures between the two hospitals. Patients, both verbally and on paper, expressed high levels of satisfaction with the services offered at both hospitals, yet in-depth, qualitative research revealed a more complex picture. The evidence from this research will be used to argue that standard consumer satisfaction questionnaires of health provision are inadequate indicators of patients' experience of health care delivery.

Adult↗
PubMed2000

What influences participation in clinical trials in palliative care in a cancer centre?

Like any other specialty, palliative care needs a scientific foundation on which to base its practice. Research in palliative care is particularly difficult because of the characteristics of the patient population under study (e.g. advanced disease, poor performance status and limited prognosis). The aim of this paper was to highlight the challenges of recruitment into clinical trials in palliative care. Information on all patients treated at a specialist cancer centre who were referred for consideration of entry into any one of 23 clinical trials in palliative care was collected prospectively over 4 years to determine factors that influence patients to accept or reject entry into a study. Of the 1206 patients referred, 558 (46%) met the entry criteria. Of these, 362 (30%) agreed to enter and 248 (21% of all those referred) completed the study. Thus, 65% of all eligible patients were entered into trials but only 44% of these completed the study. The relatively high percentage of patients entered probably reflects the site (a cancer centre with a high research profile) and is not typical of other palliative care centres or hospices. The most common reasons given for unwillingness to participate were a wish to defer to a later date, a deterioration in condition, distance from home to hospital, a lack of interest, transfer to another unit, inability to give consent and family objection. In order to maximise patient accrual into trials in palliative care, studies should be designed to suit the patient population under study (e.g. be of short duration with realistic entry criteria) and not necessarily mirror the trial methodology of therapeutic trials in oncology.

Adolescent↗
PubMed2000

Inflammatory bowel disease: epidemiology and management in an English general practice population.

BACKGROUND: Inflammatory bowel diseases have significant long-term morbidity and healthcare resource consequences. Studies based on secondary care records may have underestimated the contribution of general practitioners (GPs) to its management. AIMS: To describe the epidemiology and management of inflammatory bowel disease using GP records as the primary data source. METHODS: A systematic search of GP clinical records in northern England, identifying cases of inflammatory bowel disease, patient consultation behaviour, prescribing patterns, and extent of specialist care. RESULTS: In a population of 135 723, the incidence of ulcerative colitis was 13. 9/100 000 per year (CI: 7.5-20.3) and for Crohn's disease 8.3/100 000 per year (CI: 3.4-13.2). The age-sex adjusted point prevalence for ulcerative colitis on 1st January 1995 was 243.4/100 000 (CI: 217.4-269.4) and for Crohn's disease 144.8/100 000 (CI: 124.8-168.8). The mean number of consultations (s.d.) with specialists and GPs were similar, both in the first 12 months after referral (specialists 3.94 +/- 3.15, GPs 3.34 +/- 3.55) and in the most recent 12 months (1.02 +/- 2.02, 1.04 +/- 2.04). Only 29.9% of all patients were definitely under specialist care. CONCLUSIONS: Prevalence rates, but not incidence rates, for inflammatory bowel disease are substantially higher than previously described in UK populations. General practitioners make a significant contribution to meeting the healthcare needs of these patients.

Adult↗
PubMed2000

The effect of a nonverbal aid on preschoolers' recall for color.

The purpose of the present study was to investigate whether the provision of a nonverbal memory aid would improve preschoolers' recall of color. Forty 4-year-old children carried out 2 tasks with the same set of colored objects. Colors were not referred to, nor were children told that their recall would later be tested. One day later, the children were split into 2 groups. One group was given a chart containing both the colors of the objects and distractor colors. The other group was not given a chart. Recall for object color was tested. There was an effect of chart provision; children who used the chart recalled more colors correctly than did those who did not use a chart. This result indicates (a) that even very young children can make use of props to facilitate their recall and (b) that such memory aids need not be exact copies of previously seen objects. Implications of these findings for eyewitness recall are discussed.

Child Behavior↗
PubMed2000

Immunolocalization analysis of transforming growth factor-beta1 in the growth plates of broiler chickens with high and low incidences of tibial dyschondroplasia.

Immunolocalization of transforming growth factor-beta1 (TGF-beta1) was determined in growth plates of two lines of broiler chickens with low and high incidences of tibial dyschondroplasia (TD). Ultrathin sections of growth plates from each line were treated with a polyclonal antibody specific for TGF-beta1, followed by colloidal gold-labeled protein A. Immunolocalization for TGF-beta1 was observed in chondrocytes of all zones of growth plates of low and high TD incidence lines. However, immunolocalization in extracellular matrix was restricted to the hypertrophic zones of both lines. In the hypertrophic zone of low TD incidence line, immunolocalization of TGF-beta1 in the extracellular matrix adjacent to collapsed cartilage canals (matrix streaks) was significantly greater than immunolocalization between patent cartilage canals. A similar increase was not observed in the high TD incidence line. Results indicate that chondrocytes of all zones of the growth plate contain TGF-beta1 but do not release it into extracellular matrix until hypertrophy has occurred. Greater concentrations of TGF-beta1 adjacent to collapsed cartilage canals may play a role in controlling angiogenesis and directing invasion of mineralized hypertrophic cartilage by metaphyseal blood vessels. A low concentration of TGF-beta1 in the extracellular matrix adjacent to collapsed cartilage canals of the high TD incidence line may be a factor in limiting vascular invasion of dyschondroplastic cartilage of TD lesions.

Animals↗
PubMed2000

Heat shock protein HSP101 binds to the Fed-1 internal light regulator y element and mediates its high translational activity.

The internal light-regulatory element (iLRE) of ferredoxin (Fed-1) mRNA, comprising the 5' leader and at least the first 13 codons of the open reading frame, controls transcript abundance after illumination of the plant in a translation-dependent manner. We have characterized the RNA binding activities associated with the Fed-1 iLRE and have identified one activity as the heat shock protein HSP101, a protein shown to bind the 5' leader of tobacco mosaic virus. HSP101 was sufficient and necessary to mediate a high level of translational activity from a Fed-1 iLRE-containing mRNA in yeast. Moreover, the Fed-1 iLRE substantially enhanced translation of reporter mRNAs in plant protoplasts expressing HSP101. Expression of HSP101 was subject to developmental regulation in leaves in that expression was highest in young leaves. These data suggest that Fed-1 mRNA may use the HSP101 regulatory mechanism as a means of ensuring a high level of translation required for the light-mediated regulation of Fed-1 mRNA stability.

Binding Sites↗
PubMed2000

Audit in practice: the referral of dying patients to palliative care.

Audit should be an integral part of any palliative care service. Terminal care is a continuum of palliative care. When looking for an objective measure for referrals to a new palliative care service within a specialist cancer hospital in Ireland, patient death was used as an end point. Audits were carried out looking at inpatient deaths during two separate 8-month periods. All inpatient deaths during the study periods were noted and records compared to find those who were referred to the palliative care service before death. The first audit revealed that relatively few dying patients were referred to the newly formed palliative care team; by the time the second audit was carried out, referrals had increased. For many patients their final hospital admission was for active anti-cancer treatment and was of short duration. Data from these audits were presented on several different occasions to both nursing and medical staff. This article describes these audits in detail and highlights some of the issues raised. Audit in palliative care is discussed.

Adult↗
PubMed2000

[The effect of non-surgical periodontal therapy on blood sugar level of non-insulin dependent diabetes mellitus diabetics with periodontitis].

OBJECTIVE: To investigate the effect of periodontal therapy on blood sugar level of non-insulin dependent diabetes mellitus(NIDDM) diabetics with periodontitis. METHODS: Patients with unfavorable control of diabetes were selected from out patients of the first affiliated hospital of Sun Yat-sen University of Medical Science. The percentage of bleeding on probing, probing depth and glycosylated hemoglobin level were studied at baseline, four weeks and eight weeks after non-surgical treatment. RESULTS: The percentage of bleeding on probing and probing depth were significantly reduced in all the patients after treatment. The mean glycosylated hemoglobin level were significantly decreased in patients with advanced periodontitis while patients with moderate periodontitis showed no changes following therapy. CONCLUSIONS: The control of periodontal inflammation can improve metabolism to some extent in patients with diabetes mellitus, but the effect may relate to blood sugar level and periodontal conditions at baseline.

Aged↗
PubMed1999

Secondary structure in the 5'-leader or 3'-untranslated region reduces protein yield but does not affect the functional interaction between the 5'-cap and the poly(A) tail.

The 5'-cap structure and poly(A) tail of eukaryotic mRNAs cooperate to promote translation initiation but whether this functional interaction benefits certain classes of mRNAs has not been investigated. In this study, we investigate whether a structured 5'-leader or 3'-untranslated region (UTR) affects the cap/poly(A) tail interaction. A structured leader reduced the degree to which the 5'-cap promoted translation in plant cells and inhibited translation from capped and uncapped mRNAs equally in yeast. Secondary structure within the 3'-UTR reduced translational efficiency when adjacent to the stop codon but had little effect on the cap/poly(A) tail synergy. The functional interaction between the cap and poly(A) tail was as important for an mRNA with a structured leader or 3'-UTR as it was for an unstructured mRNA in either species, suggesting that these structures can reduce translation without affecting the functional interaction between the cap and poly(A) tail. However, the loss of Xrn1p, the major 5'-->3' exoribonuclease in yeast, abolished cap-dependent translation and the functional interaction between the cap and poly(A) tail, suggesting that the cap/poly(A) tail synergy is of particular importance under conditions of active RNA turnover.

3' Untranslated Regions↗
PubMed1999

Malignant astrocytoma cell attachment and migration to various matrix proteins is differentially sensitive to phosphoinositide 3-OH kinase inhibitors.

Phosphoinositide 3-OH kinase (PI3-K) has been shown to play an important role in the signaling pathway necessary for cytoskeletal reorganization in non-astrocytic cells. We investigated the role of PI3-K in U-251 MG human malignant astrocytoma cell adhesion and migration. Attachment of U-251 MG cells to vitronectin, fibronectin, laminin, and collagen was inhibited in a concentration-dependent manner by two specific inhibitors of PI3-K (Wortmannin and LY294002). Attachment to vitronectin, fibronectin, and laminin was more sensitive to inhibition of PI3-K (45% inhibition at 10 nM Wortmannin) than attachment to collagen (25% inhibition at 100 nM Wortmannin). Similarly, migration toward these substrates showed differential sensitivity to inhibition. Attachment of the cells to these matrix proteins resulted in an increase in PI3-K activity, as compared to that of cells in suspension, with attachment to vitronectin resulting in the greatest increase in PI3-K activity. p125 focal adhesion kinase (p125FAK) was found to co-immunoprecipitate with PI3-K from the NP40-soluble cell fraction of a 1% NP40 detergent lysate of cells in the early stages of adhesion to vitronectin and fibronectin, but not during adhesion to collagen. The expression of p125FAK protein and level of phosphorylation were similar on adherence to all three substrates. These data indicate that the sensitivity of U-251MG cell attachment and migration to PI3-K inhibitors is substrate-dependent, and that complex formation of PI3-K and p125FAK correlates with this sensitivity to PI3-K inhibitors. Our data suggest a role for PI3-K and p125FAK complex formation in PI3-K activation.

Astrocytoma↗
PubMed1999

Electromagnetic and thermal modeling of SAR and temperature fields in tissue due to an RF decoupling coil.

The finite difference time domain method is used to calculate the specific absorption rate (SAR) due to a butterfly surface coil in a realistic tissue model of the leg. The resulting temperature distribution and temperature changes are found using a finite difference solution to the bioheat transfer equation. Reasonable agreement is found between predicted temperature changes and those measured in vivo provided that the resulting hyperthermia does not induce noticeable changes in perfusion. The method is applicable to radiofrequency dosimetry problems associated with high Bo field magnetic resonance systems and where knowledge of spatial variation in SAR is important in assessing the safety of new magnetic resonance procedures.

Absorption↗