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Biomedical subjects

N Hunt

Publications and source records attributed to N Hunt.

At least 37 records · Page 2Linked to original sources
PubMed2000

Prediction of violence on a psychiatric intensive care unit.

The aim of the present study was to identify patients who were at particular risk of violent behaviour, over a period of one month in a psychiatric high dependency unit, and to examine whether particular patients could be identified at admission who would subsequently be violent. Medical records, and other documents for 52 inpatients were included. Demographic, historical and clinical data available at admission were noted. All violent incidents were recorded and classified. Seventeen of 52 patients committed physical violence, usually to the staff. Most incidents were carried out by a small number of individuals. Identifying the violent, using variables available at admission, was not possible. The ward admitted a group with a subsequent high rate of violence. Prediction within this high-risk group was not possible. Measures aimed at preventing violence on a local secure ward should apply to all patients and should not be targeted just at those that would appear to be the most likely to be violent.

Adult↗
PubMed2000

Improvement in function after valgus bracing of the knee. An analysis of gait symmetry.

The use of a valgus brace can effectively relieve the symptoms of unicompartmental osteoarthritis of the knee. This study provides an objective measurement of function by analysis of gait symmetry. This was measured in 30 patients on four separate occasions: immediately before and after initial fitting and then again at three months with the brace on and off. All patients reported immediate symptomatic improvement with less pain on walking. After fitting the brace, symmetry indices of stance and the swing phase of gait showed a consistent and immediate improvement at 0 and 3 months, respectively, of 3.92% (p = 0.030) and 3.40% (p = 0.025) in the stance phase and 11.78% (p = 0.020) and 9.58% (p = 0.005) in the swing phase. This was confirmed by a significant improvement at three months in the mean Hospital for Special Surgery (HSS) knee score from 69.9 to 82.0 (p < 0.001). Thus, wearing a valgus brace gives a significant and immediate improvement in the function of patients with unicompartmental osteoarthritis of the knee, as measured by analysis of gait symmetry.

Adult↗
PubMed2000

A confirmatory factor analysis of the Impact of Event Scale using a sample of World War II and Korean War veterans.

This study assessed the factor structure of the Impact of Event Scale (IES), a measure of intrusion and avoidance, using a sample of World War II and Korean War veterans who had experienced combat 40-50 years earlier. A series of 3 confirmatory factor analytic models were specified and estimated using LISREL 8.3. Model 1 specified a 1-factor model. Model 2 specified a correlated 2-factor model. Model 3 specified a 2-factor model with additional cross-factor loadings for Items 2 and 12. Model 3 was found to fit the data. In addition, this model was found to be a better explanation of the data than the other models. Also in addition, the correlations between the Intrusion and Avoidance factors and the 4 subscales of the 28-item General Health Questionnaire were examined to determine the distinctiveness of the two IES factors.

Aged↗
PubMed2000

The development of a tactile graphic version of IOTN for visually impaired patients.

The Index of Orthodontic Treatment Need (IOTN) is a visual-based index and has been widely used. This paper describes the development and evaluation of tactile graphics representing the aesthetic component (AC) of IOTN for the use of visually impaired patients (VI). Four tactile graphics were produced corresponding to IOTN photographs 1 (graphic 1, no treatment - mild need), 5 (graphic 2, moderate need), 8 (graphic 3, severe need; increased overjet) and 10 (graphic 4, severe need). Nine (30-50 years) expert consumers from the Royal National Institute for the Blind (RNIB) and 13 VI schoolchildren (11-16 years) evaluated the graphics. The evaluation was in terms of design features, complexity of information and ease of use. Each individual was asked to arrange the graphics in order of severity of malocclusion. The procedure was repeated after 30 min to test individual reliability (www.clinorthodres.com/cor-c-084/). The consumer group was able to identify the main features in each graphic and found them easy to use. Six had arranged the graphics correctly at the first attempt and five on their second. The children were able to distinguish the different oral features, except the overjet presentation in graphic 2. Nine children arranged the graphics correctly at the first attempt, but only six at the second. The confusion centred for both groups on presenting an increased overjet with graphic 2. A modification was undertaken to enhance the anterior-posterior nature of the image. Fifteen VI schoolchildren reassessed the modified graphics, 14 arranged them correctly at the first attempt and 13 at the second. The study concluded that IOTN tactile graphics were well accepted and showed a good reliability.

Journal Article↗
PubMed2000

The development of a tactile graphic version of IOTN for visually impaired patients.

The Index of Orthodontic Treatment Need (IOTN) is a visual-based index and has been widely used. This paper describes the development and evaluation of tactile graphics representing the aesthetic component (AC) of IOTN for the use of visually impaired patients (VI). Four tactile graphics were produced corresponding to IOTN photographs 1 (graphic 1, no treatment - mild need), 5 (graphic 2, moderate need), 8 (graphic 3, severe need; increased overjet) and 10 (graphic 4, severe need). Nine (30-50 years) expert consumers from the Royal National Institute for the Blind (RNIB) and 13 VI schoolchildren (11-16 years) evaluated the graphics. The evaluation was in terms of design features, complexity of information and ease of use. Each individual was asked to arrange the graphics in order of severity of malocclusion. The procedure was repeated after 30 min to test individual reliability (http://www.clinorthodres.com/cor-c-084/). The consumer group was able to identify the main features in each graphic and found them easy to use. Six had arranged the graphics correctly at the first attempt and five on their second. The children were able to distinguish the different oral features, except the overjet presentation in graphic 2. Nine children arranged the graphics correctly at the first attempt, but only six at the second. The confusion centred for both groups on presenting an increased overjet with graphic 2. A modification was undertaken to enhance the anterior-posterior nature of the image. Fifteen VI schoolchildren reassessed the modified graphics, 14 arranged them correctly at the first attempt and 13 at the second. The study concluded that IOTN tactile graphics were well accepted and showed a good reliability.

Journal Article↗
PubMed1999

Deposition of calcium pyrophosphate in tissue after revision arthroplasty of the hip.

We reviewed histologically the incidence and pathogenesis of the deposition of calcium pyrophosphate dihydrate (CPPD) crystals in the pseudocapsule, femoral and acetabular membranes and periprosthetic tissue at revision of 789 cases of failed total hip replacement. In 13, periprosthetic tissues were found to have deposits of CPPD crystals in areas of cartilaginous metaplasia; four also showed evidence of localised deposition of amyloid. None of the patients had a history of chondrocalcinosis in the hip or other joints. Cartilaginous metaplasia and other changes in periprosthetic tissues may predispose to the deposition of CPPD and associated localised amyloid.

Acetabulum↗
PubMed1999

Medical packaging: more for less?

The market for medical devices is governed by the need to have validated products and processes, clean manufacturing environments and proven shelf-life. All this, often for products that are disposable, low-unit-cost items and, as such, highly price sensitive. This, in turn, has an impact on the businesses supplying the market. This article considers one such supply market, packaging, and the steps taken by packaging manufacturers to respond to these pressures while maintaining long-term, viable products.

Cost-Benefit Analysis↗
PubMed1998

Enhanced high density oligonucleotide array-based sequence analysis using modified nucleoside triphosphates.

Pairs of high density oligonucleotide arrays (DNA chips) consisting of >96 000 oligonucleotides were designed to screen the entire 5.53 kb coding region of the hereditary breast and ovarian cancer BRCA1 gene for all possible sequence changes in the homozygous and heterozygous states. Single-stranded RNA targets were generated by PCR amplification of individual BRCA1 exons using primers containing T3 and T7RNA polymerase promoter tails followed by in vitro transcription and partial fragmentation reactions. Fluorescent hybridization signals from targets containing the four natural bases to >5592 different fully complementary 25mer oligonucleotide probes on the chip varied over two orders of magnitude. To examine the thermodynamic contribution of rU.dA and rA.dT target.probe base pairs to this variability, modified uridine [5-methyluridine and 5-(1-propynyl)-uridine)] and modified adenosine (2,6-diaminopurine riboside) 5'-triphosphates were incorporated into BRCA1 targets. Hybridization specificity was assessed based upon hybridization signals from >33 200 probes containing centrally localized single base pair mismatches relative to target sequence. Targets containing 5-methyluridine displayed promising localized enhancements in hybridization signal, especially in pyrimidine-rich target tracts, while maintaining single nucleotide mismatch hybridization specificities comparable with those of unmodified targets.

Base Pair Mismatch↗
PubMed1998

Function of the nasal muscles in normal subjects assessed by dynamic MRI and EMG: its relevance to rhinoplasty surgery.

The external nose is generally considered to have a relatively static shape. Movement of the nose and the potential for change of external shape and the internal airway have been assessed by (1) cadaver dissection and (2) dynamic studies during a standardized series of facial expressions in 13 subjects; video recording of the movement of skin markers, electromyography, and moving magnetic resonance images. A standard description of muscle anatomy is presented. The dynamic investigations indicated the following. Video analysis showed the components of muscle action: dilatation, constriction of the nostril, depression of the tip, vertical contraction in the bridge, and elevation of the alar, in different expressions. Electromyography confirmed muscle actions during expression and phonation. Magnetic resonance imaging demonstrated large changes in the external shape of the nose and nasal aperture due to muscle actions. Muscle function should be given greater consideration in aesthetic and cleft rhinoplasty.

Electromyography↗
PubMed1998

Strategies for mutational analysis of the large multiexon ATM gene using high-density oligonucleotide arrays.

Mutational analysis of large genes with complex genomic structures plays an important role in medical genetics. Technical limitations associated with current mutation screening protocols have placed increased emphasis on the development of new technologies to simplify these procedures. High-density arrays of >90,000-oligonucleotide probes, 25 nucleotides in length, were designed to screen for all possible heterozygous germ-line mutations in the 9.17-kb coding region of the ATM gene. A strategy for rapidly developing multiexon PCR amplification protocols in DNA chip-based hybridization analysis was devised and implemented in preparing target for the 62 ATM coding exons. Improved algorithms for interpreting data from two-color experiments, where reference and test samples are cohybridized to the arrays, were developed. In a blinded study, 17 of 18 distinct heterozygous and 8 of 8 distinct homozygous sequence variants in the assayed region were detected accurately along with five false-positive calls while scanning >200 kb in 22 genomic DNA samples. Of eight heterozygous sequence changes found in more than one sample, six were detected in all cases. Five previously unreported sequence changes, not found by other mutational scanning methodologies on these same samples, were detected that led to either amino acid changes or premature truncation of the ATM protein. DNA chip-based assays should play a valuable role in high throughput sequence analysis of complex genes.

Ataxia Telangiectasia Mutated Proteins↗
PubMed1998

Microvascular and cellular responses in the optic nerve of rats with acute experimental allergic encephalomyelitis (EAE).

The optic nerve of rats with EAE was examined at various times to determine the integrity of the blood-brain barrier (BBB) and to assess monocyte-macrophage, T cell, and microglial responses. In naive control animals, leakage of horseradish peroxidase (HRP) and the presence of cells expressing major histocompatibility complex (MHC) class II antigen were evident in the meninges of the retrobulbar optic nerve. In rats with EAE, microglia in the region of the lamina cribrosa and in the regions adjacent to the meninges became activated from day 7 to 8 postinduction (pi). HRP leakage was also evident in the region of the lamina cribrosa from day 7 to 8 pi. On day 8 pi, infiltration of inflammatory cells and Monastral blue leakage were apparent in the myelinated region of the optic nerve. The intensity of these cellular and vascular changes peaked at day 12 pi, when signs of clinical disease became manifest. Monocytes-macrophages expressing MHC class II and the ED1 antigen, together with lymphocytes expressing the alphabetaT cell receptor, constituted the major proportion of cells associated with inflammatory lesions. Thus: (i) the inherent weakness of the BBB as well as the presence of both antigen (myelin) and MHC class II+ cells in the retrobulbar optic nerve are likely susceptibility factors for the frequent involvement of this region in EAE and multiple sclerosis; and (ii) activation of microglia occurs early in the pathogenesis of experimental optic neuritis.

Animals↗
PubMed1998

Microvascular and cellular responses in the retina of rats with acute experimental allergic encephalomyelitis (EAE).

The microvascular and cellular responses in the retina during acute EAE were characterized using whole-mount preparations. The earliest detectable event was the accumulation of monocytes and T cells within veins on day 7 postinduction (pi). Mild breakdown of the blood-retinal barrier (BRB), activation of microglia and infiltration of monocytes and T cells into the retinal parenchyma were first evident on days 7 to 8 pi. Monocyte adhesion to the vessel wall and breakdown of the BRB were colocalized in the same vessel segments and occurred predominantly in veins. The marked difference in response observed in the retina versus the myelinated region of the optic nerve suggests that two types of inflammatory cascades are initiated. A mild response, characterised by very low numbers of T cells and monocytes and an absence of expression of MHC class II by resident microglia, is initiated when only small amounts of the encephalitogenic antigen are present in the perivascular space or associated with perivascular antigen-presenting cells. A full blown inflammatory reaction, as observed in the optic nerve, is initiated in the presence of substantial amounts of encephalitogenic antigen. This severe response is characterised by the infiltration of large numbers of CD4+, CD8+ T cells and ED1+ monocytes, and by abundant MHC class II expression by resident microglia as well as other cell types. Thus, MHC class II expression by resident microglia may be a possible effective amplifier mechanism if the encephalitogenic antigen is encountered in the tissue parenchyma.

Animals↗
PubMed1998

cis-Active elements of Friend spleen focus-forming virus: from disease induction to disease prevention.

The polycythemic strain of the Friend spleen focus-forming virus (SFFVp) is a replication-defective, acutely transforming retrovirus inducing a bistage erythroleukemia in susceptible mice. The first stage of the disease is an acute polyclonal erythroblastosis induced by the proliferation-promoting effect of gp55. gp55 is expressed from a spliced subgenomic message of SFFVp and stimulates the cellular receptor for erythropoietin. Using a selectable SFFVp that otherwise mimics the specificity of the disease, we demonstrate that the kinetics of the polyclonal expansion depends on the transcriptional strength of the retroviral cis-active elements. By exchanging gp55 for apathogenic genes, we show that SFFVp enhancer and splice signals can be successfully utilized for the development of retroviral vectors mediating very efficient transgene expression in hematopoietic cells. Apathogenic selectable SFFVp-based vectors carrying distinct enhancer alterations are a valuable tool to analyze transcriptional control of leukemia viruses in the absence of oncogenic proteins. Moreover they might have therapeutic potential.

Animals↗
PubMed1998

Relaxin-like factor expression as a marker of differentiation in the mouse testis and ovary.

Expression of the relaxin-like factor (RLF) was studied at the messenger RNA (mRNA) and protein levels in the testes and ovaries of the mouse, as well as through testicular development and differentiation in the mouse testis. In situ hybridization or RT-PCR, and immunohistochemistry using a polyclonal antibody raised against a recombinant protein, provided mutually confirmatory results for a high expression of RLF in the Leydig cells of the adult testis and at a much lower level of expression in the luteal cells of the ovary through the cycle, pregnancy, and in lactation. Analysis of protein and mRNA expression, through postnatal testicular development, indicated moderate RLF expression also in the fetal population of Leydig cells, even in the hpg mutant mouse, lacking an active pituitary-gonadal axis. Prepubertal Leydig cells, however, exhibit only very low-level RLF gene expression, this phenotype persisting in the adult hpg mouse. In summary, fetal Leydig cells express RLF in an LH/human CG-independent fashion, whereas LH/human CG is essential to induce RLF expression in the adult-type Leydig cell. In cultured adult Leydig cells or in the mouse tumor MA-10 cell line, RLF mRNA is expressed in a constitutive fashion. RLF thus seems to be a useful marker of Leydig cell differentiation status.

Animals↗
PubMed1998

Dependence on computer games by adolescents.

As computer game playing is a popular activity among adolescents, a questionnaire study was undertaken with 387 adolescents (12-16 years of age) to establish their "dependence" using a scale adapted from the DSM-III-R criteria for pathological gambling. Analysis indicated that one in five adolescents were currently "dependent" upon computer games. Boys played significantly more regularly than girls and were more likely to be classified as "dependent." The earlier children began playing computer games it appeared the more likely they were to be playing at "dependent" levels. These and other results are discussed in relation to research on other gaming dependencies.

Adolescent↗
PubMed1998

How effective is lithium in the prevention of relapse in bipolar disorder? A prospective naturalistic follow-up study.

OBJECTIVE: The effectiveness of lithium in preventing recurrences of bipolar disorder was examined prospectively for 2 years in two representative samples of bipolar I patients being treated in a comprehensive program following recommended guidelines. METHOD: One hundred and twenty patients were recruited from consecutive admissions to two catchment area psychiatric services (one in the United Kingdom, the other in New Zealand). They were seen at 3-monthly intervals by a member of the research team. Treatment was adjusted according to clinical needs. RESULTS: Overall, two-thirds of the patients had a recurrence. Of the 57 on lithium as sole treatment, 39 (68%) had a further episode; 17 after stopping lithium. The 42 on other mood stabilisers and/or an antipsychotic, with or without lithium, did no better. By contrast, only eight (38%) of the 21 who were taking no prophylactic medication had a recurrence. CONCLUSIONS: Lithium is much less effective in clinical practice than would be expected from clinical trial results. A major reason for this is poor compliance. Alternative treatment strategies are needed to improve the outcome for bipolar disorder patients.

Adolescent↗