Integrating wearables and modelling for monitoring rehabilitation following total knee joint replacement

BACKGROUND AND OBJECTIVE

Wearable inertial devices integrated with modelling and cloud computing have been widely adopted in the sports sector, however, their use in the health and medical field has yet to be fully realised. To date, there have been no reported studies concerning the use of wearables as a surrogate tool to monitor knee joint loading during recovery following a total knee joint replacement. The objective of this study is to firstly evaluate if peak tibial acceleration from wearables during gait is a good surrogate metric for computer modelling predicted functional knee loading; and secondly evaluate if traditional clinical patient related outcomes measures are consistent with wearable predictions.

METHODS

Following ethical approval, four healthy participants were used to establish the relationship between computer modelling predicted knee joint loading and wearable measured tibial acceleration. Following this, ten patients who had total knee joint replacements were then followed during their 6-week rehabilitation. Gait analysis, wearable acceleration, computer models of knee joint loading, and patient related outcomes measures including the Oxford knee score and range of motion were recorded.

RESULTS

A linear correlation (R² of 0.7-0.97) was observed between peak tibial acceleration (from wearables) and musculoskeletal model predicted knee joint loading during gait in healthy participants first. Whilst patient related outcome measures (Oxford knee score and patient range of motion) were observed to improve consistently during rehabilitation, this was not consistent with all patient's tibial acceleration. Only those patients that exhibited increasing peak tibial acceleration over 6-weeks rehabilitation were positively correlated with the Oxford knee score (R² of 0.51 to 0.97). Wearable predicted tibial acceleration revealed three patients with a consistent knee loading, five patients with improving knee loading, and two patients with declining knee loading during recovery. Hence, 20% of patients did not present with satisfactory joint loading following total knee joint replacement and this was not detected with current patient related outcome measures.

CONCLUSIONS

The use of inertial measurement units or wearables in this study provided additional insight into patients who were not exhibiting functional improvements in joint loading, and offers clinicians an 'off-site' early warning metric to identify potential complications during recovery and provide the opportunity for early intervention. This study has important implications for improving patient outcomes, equity, and for those who live in rural regions.

Altered N-methyl D-aspartate receptor subunit expression causes changes to the circadian clock and cell phenotype in osteoarthritic chondrocytes

The chondrocyte circadian clock is altered in osteoarthritis. This change is implicated in the disease-associated changes in chondrocyte phenotype and cartilage loss. Why the clock is changed is unknown. N-methyl-D-aspartate receptors (NMDAR) are critical for regulating the hypothalamic clock. Chondrocytes also express NMDAR and the type of NMDAR subunits expressed changes in osteoarthritis.

OBJECTIVE

To determine if NMDAR regulate the chondrocyte clock and phenotype.

DESIGN

Chondrocytes isolated from macroscopically-normal (MN) and osteoarthritic human cartilage were treated with NMDAR antagonists or transfected with GRIN2A or GRIN2B-targetting siRNA. H5 chondrocytes were transfected with GluN2B-expression plasmids. Clock genes and chondrocyte phenotypic markers were measured by RT-qPCR.

RESULTS

PER2 amplitude was higher and BMAL1 amplitude lower in osteoarthritic compared to MN chondrocytes. In osteoarthritic chondrocytes, NMDAR inhibition restored PER2 and BMAL1 expression to levels similar to MN chondrocytes, and resulted in reduced MMP13 and COL10A1. Paradoxically, NMDAR inhibition in MN chondrocytes resulted in increased PER2, decreased BMAL1 and increased MMP13 and COL10A1. Osteoarthritic, but not MN chondrocytes expressed GluN2B NMDAR subunits. GluN2B knockdown in osteoarthritic chondrocytes restored expression of circadian clock components and phenotypic markers to levels similar to MN chondrocytes. Ectopic expression of GluN2B resulted in reduced BMAL1, increased PER2 and altered SOX9, RUNX2 and MMP13 expression. Knockdown of PER2 mitigated the effects of GluN2B on SOX9 and MMP13.

CONCLUSIONS

NMDAR regulate the chondrocyte clock and phenotype suggesting NMDAR may also regulate clocks in other peripheral tissues. GluN2B expression in osteoarthritis may contribute to pathology by altering the chondrocyte clock.

Clozapine – a survey of patient perceptions

Aims and Method

We aimed to find out how patients on clozapine felt about clozapine treatment. A structured questionnaire was given to 1284 consecutive patients attending 27 clozapine clinics in the UK.

Results

The response rate was 44.4% (570 forms returned). This cohort of responders to the questionnaire consisted, for the most part, of Caucasian males who had been taking clozapine for more than 2 years. Respondents expressed largely favourable views on clozapine treatment. For example, 86.1% claimed to feel better on clozapine and 88.6% claimed to prefer to remain on clozapine than to change to another drug. Many patients stated that they disliked having to undergo blood testing, but a large majority (87.0%) felt that the advantages of clozapine outweighed disadvantages. All other responses supported this overall favourable view of clozapine therapy.

Clinical Implications

Patients stabilised on clozapine are largely content with their treatment. These results suggest that clozapine is effective as assessed by patients' own standards and that adherence to therapy is likely to be good.

Dietary treatment of Crohn's disease: perceptions of families with children treated by exclusive enteral nutrition, a questionnaire survey

Background

Diet is strongly associated with the aetiology of Crohn’s Disease (CD) and exclusive enteral nutrition (EEN) is the primary induction treatment in paediatric CD. This study explored opinions around the use of EEN and alternative novel, solid food-based diets (SFDs) expressed by paediatric patients with CD, previously treated with EEN and their parents.

Methods

This anonymous questionnaire surveyed families of CD patients treated with EEN over 1 year. Two questionnaire forms were completed; one asking the patients’ opinions and another referring to their main carer. This questionnaire explored participants’ demographic characteristics; acceptability of a repeat EEN course to treat a future flare (EEN repeat); their opinion on how difficult EEN would be compared to an example SFD; and their intention to participate in a future clinical trial assessing the therapeutic efficacy of an SFD in CD.

Results

Forty-one families of CD patients were approached with 29 sending replies (71%). Most of our participants were positive on completing another EEN course, however the majority would choose an SFD alternative (Patients:66, Parents:72%). Both patients and their parents rated EEN to be more difficult to adhere to compared to an example SFD (p < 0.05), and their ratings were strongly correlated (EEN:r = 0.83, SFD:r = 0.75, p < 0.001). The majority of our respondents would agree to participate in a clinical trial assessing an SFD’s effectiveness (Patients:79, Parents:72%) for the management of active CD.

Conclusions

While patients with CD and their families would accept an EEN repeat, the majority would prefer an SFD alternative. CD families surveyed are supportive of the development of solid food-based dietary treatments.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0564-7) contains supplementary material, which is available to authorized users.

The national incidence and clinical picture of SLE in children in Australia – a report from the Australian Paediatric Surveillance Unit

Objectives

The objectives of this paper are to prospectively determine the incidence of paediatric systemic lupus erythematosus (pSLE) in Australia as well as describe the demographics, clinical presentation and one-year outcome.

Study design

Newly diagnosed cases of pSLE were ascertained prospectively from October 2009 to October 2011 through the Australian Paediatric Surveillance Unit (a national monthly surveillance scheme for notification of childhood rare diseases) as well as national subspecialty groups. Questionnaires were sent to notifying physicians at presentation and at one year.

Results

The annual incidence rate was 0.32 per 105 children aged less than 16 years. The incidence was significantly higher in children of Asian or Australian Aboriginal and Torres Strait Islander parents. Approximately one-third of children underwent a renal biopsy at presentation and 7% required dialysis initially although only one child had end-stage kidney disease (ESKD) at one-year follow-up.

Conclusion

The incidence of pSLE in Australia is comparable to that worldwide with a significantly higher incidence seen in children of Asian and Australian Aboriginal and Torres Strait Islander backgrounds. Renal involvement is common but progression to ESKD, at least in the short term, is rare.

Gill-associated virus and its association with decreased production of Penaeus monodon in Australian prawn farms

Gill-associated virus (GAV) was found to be associated with decreased prawn, Penaeus monodon, production when prawns from three farms (n = 45 ponds, 1800 prawns) were monitored for GAV over the production season using a graded RT-nPCR. The grading system used was a visualization of either the outer or inner nested PCR products. Prevalence and loading of GAV were associated with disease severity. Ponds with a higher initial prevalence and a larger increase in GAV load over the production period suffered disease outbreaks. Ponds with low initial prevalence of GAV but a larger increase in prevalence and large increase in load over the production period suffered chronic disease with no disease outbreak identified, yet low production. However, the ponds with moderate to low initial prevalence of GAV with a low increase in prevalence and load of GAV over the production period incurred no disease outbreak and comparatively high production. Ponds with GAV prevalence greater than 75% at 1 month post-stocking should be considered for termination as they have a high probability (95%) of having a disease outbreak. Emergency harvest when a disease outbreak occurs will significantly limit mortality losses.

Effect of dopamine D3 receptor gene polymorphisms and clozapine treatment response: exploratory analysis of nine polymorphisms and meta-analysis of the Ser9Gly variant

D2 blockade has been implicated in having a central role in antipsychotic response. However, treatment refractoriness, in spite of complete D2 blockade, as well as the efficacy of clozapine (CLZ) in a portion of this patient population, indicates the involvement of other factors as well. Several lines of evidence suggest a role for D3. Furthermore, an earlier meta-analysis by Jönsson et al. (2003) (n=233) suggested a role for genetic variation in the D3 gene. Relevant to this study, Jönsson et al. found the Ser allele of the D3 serine-to-glycine substitution at amino acid position 9 (Ser9Gly) polymorphism to be associated with worse CLZ response compared with the Gly allele. In this study, we attempt to validate these findings by performing a meta-analysis in a much larger sample (n=758). Eight other variants were also tested in our own sample to explore the possible effect of other regions of the gene. We report a negative but consistent trend across individual studies in our meta-analysis for the DRD3 Ser allele and poor CLZ response. A possible minor role for this single-nucleotide polymorphism cannot be disregarded, as our sample size may have been insufficient. Other DRD3 variants and haplotypes of possible interest were also identified for replication in future studies.

No association between ADRA2A polymorphisms and schizophrenia

There is evidence to suggest that the alpha(2A)-adrenergic receptor may be involved in schizophrenia. With attention directed at the upstream regulatory region of the gene which codes for this receptor (ADRA2A), we proposed that single nucleotide polymorphisms (SNPs) within this region influences susceptibility to schizophrenia by altering the expression of this receptor. We opted to test for an influence on susceptibility by association study using 112 schizophrenic/schizoaffective disorder patients and 159 controls. The region of interest was screened for SNPs using a combination of bioinformatic searches and sequencing. A total of nine SNPs were discovered, of which four (-5972-G/A, -2211-A/T, -1291-C/G and -261-G/A) were genotyped in the entire clinical sample. No associations were evident, suggesting no influence for these SNPs in susceptibility to schizophrenia.

Sensitivity and specificity of current diagnostic tests for gill-associated virus in Penaeus monodon

This study reports the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy between a reverse transcriptase-nested polymerase chain reaction (RT-nPCR) and an enzyme-linked immunosorbent assay (ELISA) for the detection of gill-associated virus (GAV) from a sample of 120 Penaeus monodon. Subsequently, the same comparisons were applied to the ELISA and haemagglutination (HA) assays for detection of GAV from a second 120 prawns. The optical density (OD) or dilution cut-off point had a direct influence on the tested parameters. The cut-off OD of 0.5-0.6 with the ELISA produced a sensitivity of 98% compared with RT-nPCR. However, these OD produced the lowest accuracy (85.8% and 86.7%, respectively). The OD cut off of 0.75 resulted in the highest accuracy (91.7%) and NPV (81.3%) while it had the second highest sensitivity (97%) and PPV (93.3%). However, the OD cut off of 0.9 had the highest specificity (80%). With regards to HA, the titre cut off at 8 resulted in the highest sensitivity, specificity and NPV (94%, 100% and 100%, respectively) compared with the ELISA, while the HA titre of 16 gave the highest accuracy (73%) and the second highest specificity (75%). A HA titre of 64 gave the highest PPV (81%). Using the RT-nPCR as the gold standard, the ELISA had an accuracy of 91.7% when using a cut off >0.75 as a positive result. When compared with the ELISA, the HA had an accuracy of 73% when using an HA titre cut off greater than 16 as a positive result. These results indicate that alternative tests for GAV (ELISA and HA) can be used to explore multiple questions about the disease status of P. monodon stocks in a cost-effective manner.

Quantitative computer-assisted osteodensitometry in total hip arthroplasty

Several factors can cause bone loss and fixation failure following total hip arthroplasty (THA), including polyethylene wear debris, implant micromotion and stress shielding. Various techniques have been used in an effort to detect bone density loss in vivo, all with varying success. Quantitative computed tomography (qCT)-assisted osteodensitometry has been shown to be useful in assessing the in vivo structural bone changes after THA. It has a high resolution, accuracy and reproducibility, thereby making it a useful tool for research purposes, and it is able to differentiate between cortical and cancellous bone structures and assess the bone/implant interface. This technique also provides valuable information about the pattern of stress shielding which occurs around the prosthesis and can show early bony changes, which may prove informative about the quality of implant fixation and surrounding bone adaptation. In conjunction with finite-element analysis, qCT is able to generate accurate patient-specific meshes on which to model implants and their effect on bone remodelling. This technology can be useful to predict bone remodelling and the quality of implant fixation using prostheses with different design and/or biomaterials. In the future, this tool could be used for pre-clinical validation of new implants before their introduction in the market-place.

Effectiveness of measures to reduce emergency department waiting times: a natural experiment

OBJECTIVES

To determine what measures were introduced by emergency departments in response to the national monitoring week in March 2003, and which, if any, of these were most effective in reducing waiting times.

METHODS

A postal survey of all emergency departments in England was undertaken to gather data on measures taken. Department waiting times before, during, and after monitoring week were determined from data held by the Department of Health and linked to the survey data for analysis.

RESULTS

A total of 111/198 responses (56%) were received. Departments had taken a wide range of measures to improve waiting times. The commonest were additional senior doctor hours (39%), creation of a "four hour monitor" role (37%), improved access to emergency beds (36%), additional non-clinical staff hours (33%), additional junior doctor hours (32%), additional nursing hours (29%), and triage by senior staff (28%). In 35 departments (32%) no changes were made at all to usual practice. The biggest influence on improved performance during monitoring week was the number of measures that a department took, rather than any specific measure, although there was weak evidence that additional junior medical and non-clinical staff time may have contributed more than other measures.

CONCLUSIONS

Improved waiting time performance may depend, at least in the short term, more on the amount of effort expended than on introducing a single effective change. In addition, those measures most likely to be helpful are likely also to require additional resources.

[Development of a synthetic positive control which also detects plasmid contamination in diagnostic polymerase chain reaction]

This paper describes a technique for the development of a positive control for use in a nested PCR to show that the PCR has worked correctly with both outer and inner primers designed for diagnostic amplification of 618 bp and 317 bp products respectively. This positive control produces a larger product than the diagnostic sample that can be discriminated on an agarose gel. This technique is advantageous over traditional cloning of the diagnostic PCR product itself by: 1) making it visually easy to detect plasmid contamination and thus, prevent false positives from the plasmid; 2) develop a positive control when the target organism is at a very low prevalence so initial detection is not relied on for cloning positive controls. This will ensure the PCR is working correctly prior to diagnostic sampling, reducing false negatives; or 3) for developing a PCR and determining the sensitivity prior to the use of diagnostic samples. The methods used to produce this nested positive control demonstrates how to use large oligonucleotide primers in PCR without non-specific binding occurring.

Pre-formed articulating knee spacer in two-stage revision for the infected total knee arthroplasty

We performed a prospective study to assess safety and effectiveness of a pre-formed articulating spacer made of gentamicin-impregnated acrylic cement in the management of infected total knee arthroplasty. Twenty-one consecutive patients with unilateral deep infection were treated by two-stage revision in two centres. Two patients were excluded, and 19 patients remained available for assessment. The mean implantation time of the spacer was 12 weeks. The rehabilitation programme between stages consisted in early range of motion exercises and partial weight bearing. Mean follow-up after removal of the spacer and insertion of the final prosthesis was 24 (range, 12-43) months. No patient had recurrence of infection at the latest follow-up. The mean Knee Society functional score during spacer management was rated 75 points and was rated 84 points at the latest follow-up. No device-related complication was observed.

A novel Shigella dysenteriae serovar isolated in Canada

The etiological agent most commonly associated with bacillary dysentery is Shigella. As part of its mandate, the Bacteriology and Enteric Disease Program of Health Canada identifies and serotypes unusual isolates of Shigella received from provincial laboratories of public health. In this report, six unusual isolates from three provinces were analyzed biochemically and serologically using slide and tube agglutinations and molecularly using standard pulsed-filed gel electrophoresis (PFGE), PCR, and PCR-restriction fragment length polymorphism (RFLP) techniques. All six isolates were identical. PFGE analysis grouped these strains; biochemically, they were mannitol negative and consistent with the profile of Shigella. Serologically, these strains produced weak reactions in Shigella dysenteriae serovars 4 and 16 and Escherichia coli O159 and O173 antisera. Molecular serotyping by PCR-RFLP of the rfb gene produced an S. dysenteriae serovar 2/E. coli O112ac pattern. They were positive by PCR for ipaH and ial enteroinvasive genes but negative for all other genes tested. Antiserum was prepared from one of the isolates and tested against Shigella and E. coli reference strains as well as the other isolates. The antiserum reacted with the five remaining isolates and showed cross-reactivity with S. dysenteriae serovars 1, 4, and 16; Shigella flexneri type 3; and E. coli O118, O159, O168, O172, and O173 antigens. Absorbing the sera with E. coli O159 and S. dysenteriae serovar 4 antigen removed all cross-reactions and only slightly reduced the homologous titer. Based on biochemical, molecular, and complete serological analysis, we propose that these six isolates represent a new provisional serovar of S. dysenteriae, type strain BEDP 02-5104.

Amisulpride augmentation of clozapine: an open non-randomized study in patients with schizophrenia partially responsive to clozapine

OBJECTIVE

Treatment options are very limited for individuals with schizophrenia resistant to clozapine. We tested the hypothesis that amisulpride augmentation would lead to an improvement in these patients.

METHOD

This was an open non-randomized study. Thirty-three patients with sub-optimal response to clozapine were commenced on amisulpride in addition to clozapine. Clinical status was evaluated at baseline, 3 and 6 months using the Positive And Negative Syndrome Scale (PANSS), Scale for the Assessment of Negative Symptoms (SANS), Global Assessment Scale (GAS), Calgary Depression Scale, Calgary Anxiety Scale and various side effect rating scales.

RESULTS

Twenty-eight subjects completed 6 months treatment on clozapine and amisulpride. There was a statistically significant improvement in the mean scores for PANSS, SANS and GAS at follow-up and no significant changes in side effect ratings.

CONCLUSION

Co-administration of amisulpride, in a group of patients partially or non-responsive to clozapine, may lead to a substantial improvement in positive and negative symptoms, without worsening the side effect burden.

Do budget-holding physicians respond to price? the case of fundholding in the UK

In an effort to improve the efficiency of the healthcare sector, some countries have experimented with various forms of 'internal market' in public healthcare provision. In some models, policymakers have assumed that actors will behave, as in a retail market, by responding to price in the course of seeking the best 'value for money' from healthcare providers. In the study reported here we examined the responsiveness of general practitioners to price during the British experiment in general practice (GP) fundholding. The study analysed routine data on 29 423 referrals for elective care made by 129 practices in one city to two competing providers of secondary care. Indices of price responsiveness were calculated for each practice from their manifest referral behaviour. These were then used to compare fundholding and non-fundholding practices. The results showed no difference between these groups in their propensity to respond to published procedure prices, even when potential savings were very large. Our findings are consistent with the reported views of fundholding GPs that price was a secondary consideration in their referral behaviour, and provides further evidence that healthcare markets cannot be understood in simplistic terms.

NHS Direct: consistency of triage outcomes

OBJECTIVES

To examine the consistency of triage outcomes by nurses using four types of computerised decision support software in NHS Direct.

METHODS

119 scenarios were constructed based on calls to ambulance services that had been assigned the lowest priority category by the emergency medical dispatch systems in use. These scenarios were presented to nurses working in four NHS Direct call centres using different computerised decision support software, including the NHS Clinical Assessment System.

RESULTS

The overall level of agreement between the nurses using the four systems was "fair" rather than "moderate" or "good" (kappa=0.375, 95% CI: 0.34 to 0.41). For example, the proportion of calls triaged to accident and emergency departments varied from 22% (26 of 119) to 44% (53 of 119). Between 21% (25 of 119) and 31% (37 of 119) of these low priority ambulance calls were triaged back to the 999 ambulance service. No system had both high sensitivity and specificity for referral to accident and emergency services.

CONCLUSIONS

There were large differences in outcome between nurses using different software systems to triage the same calls. If the variation is primarily attributable to the software then standardising on a single system will obviously eliminate this. As the calls were originally made to ambulance services and given the lowest priority, this study also suggests that if, in the future, ambulance services pass such calls to NHS Direct then at least a fifth of these may be passed back unless greater sensitivity in the selection of calls can be achieved.

Investigation of promoter variants of the histamine 1 and 2 receptors in schizophrenia and clozapine response

We report the identification of four novel histamine 1 (H1-17-C/T, -974-C/A, -1023-A/G and -1536-G/C) and four novel histamine 2 promoter polymorphisms (H2-294-A/G, -592-A/G, -1018-G/A and -1077-G/A) which we have investigated for involvement in susceptibility to schizophrenia, and in clinical response to clozapine treatment. We identified a weak independent association between variants at the H1-1536-G/C locus and schizophrenia, where an excess of the H1-1536-C allele was observed amongst such patients (P = 0.036). However upon correction for multiple testing this relationship was no longer statistically significant. Similar investigation of the H2 receptor polymorphisms revealed association between genotype at the H2-1018-G/A locus and clinical response to clozapine treatment (P = 0.027), though upon correction for multiple testing this difference was no longer significant. We have concluded that the participation of these variants in the disorder is unlikely, particularly in view of their apparent lack of function and unlikely influence on receptor expression. However their nature alludes to the potential presence of other more important alterations further along these regions, where sequences encoding alternate promoters have recently been identified for each receptor that may yet be found to harbour such polymorphisms.

Impact of NHS Direct on other services: the characteristics and origins of its nurses

OBJECTIVE

To characterise the NHS Direct nurse workforce and estimate the impact of NHS Direct on the staffing of other NHS nursing specialties.

METHOD

A postal survey of NHS Direct nurses in all 17 NHS Direct call centres operating in June 2000.

RESULTS

The response rate was 74% (682 of 920). In the three months immediately before joining NHS Direct, 20% (134 of 682, 95% confidence intervals 17% to 23%) of respondents had not been working in the NHS. Of the 540 who came from NHS nursing posts, one fifth had come from an accident and emergency department or minor injury unit (110 of 540), and one in seven from practice nursing (75 of 540). One in ten (65 of 681) nurses said that previous illness, injury, or disability had been an important reason for deciding to join NHS Direct. Sixty two per cent (404 of 649) of nurses felt their job satisfaction and work environment had improved since joining NHS Direct.

CONCLUSION

The NHS Direct nurse workforce currently constitutes a small proportion (about 0.5%) of all qualified nurses in the NHS, although it recruits relatively experienced and well qualified nurses more heavily from some specialties, such as accident and emergency nursing, than others. However, its overall impact on staffing in any one specialty is likely to be small. NHS Direct has succeeded in providing employment for some nurses who might otherwise be unable to continue in nursing because of disability.

The reported use of dietary supplements (sip feeds) in hospitals in Wessex, UK

AIMS

To assess the prevalence of the use of supplements (sip feeds) in district general, psychiatric and community hospitals in the former Wessex health region.

METHOD

Cross sectional study of prevalence and determinants of supplement use in 10 district general hospitals (covering medical, surgical, orthopaedic, and elderly specialities), 4 psychiatric hospitals and 3 community hospitals.

RESULTS

Overall 14% of patients were being supplemented although the variation across hospitals and specialities was wide (0%-35%); elderly care patients within district hospitals were most likely to be supplemented (20%; range 12-35%). In 34% of patients there was no documented reason as to why supplements were given. 60% of patients were not weighed on admission; 70% did not have a weight history recorded and 83% did not have a current weight recorded. Documentation regarding supplement use appeared to be recorded in an unsystematic manner.

CONCLUSIONS

Many patients were not being weighed on admission and appeared to have no documentation as to why supplements were given. Given the importance of malnutrition in hospital patients a more evidence based, objective approach to assessing nutritional requirements, intake and support may be beneficial.

Human fibroblast replicative senescence can occur in the absence of extensive cell division and short telomeres

Ectopic expression of telomerase blocks both telomeric attrition and senescence, suggesting that telomeric attrition is a mitotic counting mechanism that culminates in replicative senescence. By holding human fibroblast cultures confluent for up to 12 weeks at a time, we confirmed previous observations and showed that telomeric attrition requires cell division and also, that senescence occurs at a constant average telomere length, not at a constant time point. However, on resuming cell division, these long-term confluent (LTC) cultures completed 15-25 fewer mean population doublings (MPDs) than the controls prior to senescence. These lost divisions were mainly accounted for by slow cell turnover of the LTC cultures and by permanent cell cycle exit of 94% of the LTC cells, which resulted in many cell divisions being unmeasured by the MPD method. In the LTC cultures, p27(KIP1) accumulated and pRb became under-phosphorylated and under-expressed. Also, coincident with permanent cell cycle exit and before 1 MPD was completed, the LTC cultures upregulated the cell cycle inhibitors p21(WAF) and p16(INK4A) but not p14(ARF) and developed other markers of senescence. We then tested the relationship between cell cycle re-entry and the cell cycle-inhibitory proteins following subculture of the LTC cultures. In these cultures, the downregulation of p27(KIP1) and the phosphorylation of pRb preceded the complete resumption of normal proliferation rate, which was accompanied by the down-regulation of p16(INK4A). Our results show that most normal human fibroblasts can accumulate p16(INK4A), p21(WAF) and p27(KIP1) and senesce by cell division-independent mechanism(s). Furthermore, this form of senescence likely requires p16(INK4A) and perhaps p27(KIP1).

Applications of pharmacogenetics in psychiatry: personalisation of treatment

In spite of the lack of epidemiological information, pharmacogenetic research has produced evidence of the relationship between genes and treatment response. Genetic variants of metabolic enzymes are related to toxic reactions; polymorphisms in genes coding for drug-targeted neurotransmitter receptors influence therapeutic efficacy. Also, recent studies have shown that response to antipsychotic drugs can be predicted by looking at the individual's pharmacogenetic profile. In addition to providing the first evidence that treatment response can be predicted by looking at a core of key genes, these studies illustrate the feasibility of individualisation of psychiatric treatment.

Polymorphisms in the genes for mGluR types 7 and 8: association studies with schizophrenia

A dysfunctional glutamatergic system has been implicated in the pathophysiology of schizophrenia. The group III metabotropic glutamate receptor (mGluR) types 7 and 8 presynaptically inhibit glutamate release, thereby modulating glutamatergic transmission in the brain. We conducted association studies to investigate the novel Tyr433Phe (mGluR7) variant and the 2846-C/T (mGluR8) polymorphism in schizophrenia. Both variants, present at high frequencies, failed to demonstrate any significant association with schizophrenia (mGluR7 [Tyr433Phe] allele: P=0.33; genotype: P=0.63; mGluR8 [2846-C/T] allele: P=0.72; genotype: P=0.63).

Systematic screening of the 14-3-3 eta (eta) chain gene for polymorphic variants and case-control analysis in schizophrenia

The neuronal protein 14-3-3 eta is a candidate gene for schizophrenia because it maps chromosome 22q12, a region implicated in the disease by linkage analysis, and is involved in brain development. We systematically screened this gene for polymorphic variants by comparison of public EST sequence data (five cDNAs and 72 ESTs, 21,155 bp of sequence) in parallel with single-stranded conformational polymorphism analysis, and we compared these methods by using a simple power calculation. Twelve potential polymorphisms were identified from EST sequence comparison, and two of these (a 5'-VNTR and 753G/A) were confirmed by SSCP analysis and sequencing. Three additional infrequent polymorphisms (-408T/G; 177 C/G; and 989 A/G) were found by SSCP only. We next examined these variants for association with schizophrenia. One variant in untranslated region of exon 1 (-408 T/G) was found to occur more frequently in the schizophrenic subjects (8%) than the controls (3%; P = 0.01). After fivefold correction of the P value for multiple testing, marginal association was found. Haplotype analysis of pairs of polymorphisms provided no evidence for association of this gene with schizophrenia in the population studied. Am. J. Med. Genet. (Neuropsychiatr. Genet. ) 96:736-743, 2000.

Identification of novel polymorphisms in the 5' flanking region of CYP1A2, characterization of interethnic variability, and investigation of their functional significance

CYP1A2 activity has been demonstrated to be bimodally or trimodally distributed in several populations, consistent with a codominant or recessive functional genetic polymorphism. However, studies aimed at identifying polymorphisms in CYPIA2 have not yet adequately accounted for this distribution pattern. To search for functional polymorphisms, we performed genome-walking, polymerase chain reaction (PCR) sequencing, and cloning, and identified three novel polymorphisms in the 5' flanking region of CYP1A2: a T-3591G substitution, a G-3595T substitution, and a T-3605 insertion. The frequency of the T-3591G substitution was determined by a PCR-restriction fragment length polymorphism assay, and found to be significantly higher (P < 0.0001) in Taiwanese (allele frequency 0.128, n = 125) compared to Caucasians (0.017, n = 87) or African Americans (0.024, n = 104). The functional consequence of the T-3591G and the G-3595T substitutions was determined by site-directed mutagenesis followed by transient transfection experiments. The T-3591G mutation was shown to be nonfunctional, while although the G-3595T mutation appeared to result in an increase in promoter activity, this was only to a small degree and therefore unlikely to be important in vivo. In addition, we report 532 bases of 5' flanking sequence further upstream than that reported to date, and four sequence discrepancies compared to the original published sequence (G-3649C, deltaT-3650, deltaA-4072, and C-4093 ins).

New labour and Britain's National Health Service: an overview of current reforms

Britain's National Health Service (NHS) has been the subject of unprecedented market reforms, which have failed to solve its problems. The New Labour government elected in 1997 has halted the drive toward the marketization of health care and replaced cost with quality as the central concern of NHS administration and policy. Major changes are occurring in the regulation of professional activity, with profound implications for the medical profession and the health service. The authors discuss these changes and possible future problems for the NHS.