An integrative collaborative care model for people with mental illness and physical comorbidities

BACKGROUND

Many individuals with mental health problems have comorbid physical conditions, or may present with substance/alcohol misuse or abuse issues. This results in complex treatment challenges that may not be adequately addressed by a model of care that is solely delivered by an individual clinician using a sole intervention. Mainstream pharmacotherapeutic treatment of mental health problems often have limited effectiveness in completely resolving symptoms, and may cause adverse side effects. Adjunctive treatment approaches, including nutraceuticals, lifestyle and behaviour change interventions, are widely used to assist with treatment of mental health problems. However, whilst these can be generally safer with fewer side effects, they have varying levels of evidentiary support. These circumstances warrant reframing the current treatment approach towards a more evidence-based integrative model which may better address the real-world challenges of psychiatric disorders and comorbid physical conditions. In essence, this means developing an integrative model of care which embodies an evidence-informed, personalized stepwise approach using both conventional pharmacological treatments alongside novel adjunctive treatments (where applicable) via the application of a collaborative care approach.

DISCUSSION

In order to inform this position, a brief review of findings on common patterns of comorbidity in mental illness is presented, followed by identification of limitations of conventional treatments, and potential applications of integrative medicine interventions. Advantages and challenges of integrative mental health care, collaborative models of care, review of research highlights of select integrative approaches, and comment on potential cost advantages are then discussed. We propose that a collaborative care model incorporating evidence-based integrative medicine interventions may more adequately address mental health problems with comorbid medical conditions. Robust research is now required of such a model, potentially within an integrative clinical practice.

Sex-specific relevance of diabetes to occlusive vascular and other mortality: a collaborative meta-analysis of individual data from 980 793 adults from 68 prospective studies

BACKGROUND

Several studies have shown that diabetes confers a higher relative risk of vascular mortality among women than among men, but whether this increased relative risk in women exists across age groups and within defined levels of other risk factors is uncertain. We aimed to determine whether differences in established risk factors, such as blood pressure, BMI, smoking, and cholesterol, explain the higher relative risks of vascular mortality among women than among men.

METHODS

In our meta-analysis, we obtained individual participant-level data from studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration that had obtained baseline information on age, sex, diabetes, total cholesterol, blood pressure, tobacco use, height, and weight. Data on causes of death were obtained from medical death certificates. We used Cox regression models to assess the relevance of diabetes (any type) to occlusive vascular mortality (ischaemic heart disease, ischaemic stroke, or other atherosclerotic deaths) by age, sex, and other major vascular risk factors, and to assess whether the associations of blood pressure, total cholesterol, and body-mass index (BMI) to occlusive vascular mortality are modified by diabetes.

RESULTS

Individual participant-level data were analysed from 980 793 adults. During 9·8 million person-years of follow-up, among participants aged between 35 and 89 years, 19 686 (25·6%) of 76 965 deaths were attributed to occlusive vascular disease. After controlling for major vascular risk factors, diabetes roughly doubled occlusive vascular mortality risk among men (death rate ratio [RR] 2·10, 95% CI 1·97-2·24) and tripled risk among women (3·00, 2·71-3·33; χ2 test for heterogeneity p<0·0001). For both sexes combined, the occlusive vascular death RRs were higher in younger individuals (aged 35-59 years: 2·60, 2·30-2·94) than in older individuals (aged 70-89 years: 2·01, 1·85-2·19; p=0·0001 for trend across age groups), and, across age groups, the death RRs were higher among women than among men. Therefore, women aged 35-59 years had the highest death RR across all age and sex groups (5·55, 4·15-7·44). However, since underlying confounder-adjusted occlusive vascular mortality rates at any age were higher in men than in women, the adjusted absolute excess occlusive vascular mortality associated with diabetes was similar for men and women. At ages 35-59 years, the excess absolute risk was 0·05% (95% CI 0·03-0·07) per year in women compared with 0·08% (0·05-0·10) per year in men; the corresponding excess at ages 70-89 years was 1·08% (0·84-1·32) per year in women and 0·91% (0·77-1·05) per year in men. Total cholesterol, blood pressure, and BMI each showed continuous log-linear associations with occlusive vascular mortality that were similar among individuals with and without diabetes across both sexes.

INTERPRETATION

Independent of other major vascular risk factors, diabetes substantially increased vascular risk in both men and women. Lifestyle changes to reduce smoking and obesity and use of cost-effective drugs that target major vascular risks (eg, statins and antihypertensive drugs) are important in both men and women with diabetes, but might not reduce the relative excess risk of occlusive vascular disease in women with diabetes, which remains unexplained.

FUNDING

UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Union BIOMED programme, and National Institute on Aging (US National Institutes of Health).

Gd(III) complexes as paramagnetic tags: Evaluation of the spin delocalization over the nuclei of the ligand

Complexes of the Gd(III) ion are currently being established as spin labels for distance determination in biomolecules by pulse dipolar spectroscopy. Because Gd(III) is an f ion, one expects electron spin density to be localized on the Gd(III) ion - an important feature for the mentioned application. Most of the complex ligands have nitrogens as Gd(III) coordinating atoms. Therefore, measurement of the (14)N hyperfine coupling gives access to information on the localization of the electron spin on the Gd(III) ion. We carried out W-band, 1D and 2D (14)N and (1)H ENDOR measurements on the Gd(III) complexes Gd-DOTA, Gd-538, Gd-595, and Gd-PyMTA that serve as spin labels for Gd-Gd distance measurements. The obtained (14)N spectra are particularly well resolved, revealing both the hyperfine and nuclear quadrupole splittings, which were assigned using 2D Mims ENDOR experiments. Additionally, the spectral contributions of the two different types of nitrogen atoms of Gd-PyMTA, the aliphatic N atom and the pyridine N atom, were distinguishable. The (14)N hyperfine interaction was found to have a very small isotropic hyperfine component of -0.25 to -0.37MHz. Furthermore, the anisotropic hyperfine interactions with the (14)N nuclei and with the non-exchangeable protons of the ligands are well described by the point-dipole approximation using distances derived from the crystal structures. We therefore conclude that the spin density is fully localized on the Gd(III) ion and that the spin density distribution over the nuclei of the ligands is rightfully ignored when analyzing distance measurements.

The motherhood choices decision aid for women with rheumatoid arthritis increases knowledge and reduces decisional conflict: a randomized controlled trial

BACKGROUND

For many women with Rheumatoid Arthritis (RA) motherhood decisions are complicated by their condition and complex pharmacological treatments. Decisions about having children or expanding their family require relevant knowledge and consultation with their family and physician as conception and pregnancy has to be managed within the RA context. Relevant information is not readily available to women with RA. Therefore a randomized controlled study was conducted to evaluate the effectiveness of a new motherhood decision aid (DA) developed specifically for women with RA.

METHODS

One hundred and forty-four women were randomly allocated to either an intervention or control group. All women completed a battery of questionnaires at pre-intervention, including, the Pregnancy in Rheumatoid Arthritis Questionnaire (PiRAQ), the Decisional Conflict Scale (DCS), the Hospital Anxiety and Depression Scale (HADS), and the Arthritis Self-Efficacy Scale (ASES), and provided basic demographic information. Women in the DA group were sent an electronic version of the DA, and completed the battery of questionnaires for a second time post-intervention.

RESULTS

Women who received the DA had a 13 % increase in relevant knowledge (PiRAQ) scores and a 15 % decrease in scores on the decisional conflict (DCS), compared to the control group (1 %, 2 % respectively). No adverse psychological effects were detected as evident in unchanged levels of depression and anxiety symptoms.

CONCLUSIONS

The findings of this study suggest that this DA may be an effective tool in assisting women with RA when contemplating having children or more children.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, http://www.anzctr.org.au/ , ACTRN12615000523505.

Zero field splitting fluctuations induced phase relaxation of Gd3+ in frozen solutions at cryogenic temperatures

Distance measurements using double electron-electron resonance (DEER) and Gd(3+) chelates for spin labels (GdSL) have been shown to be an attractive alternative to nitroxide spin labels at W-band (95GHz). The maximal distance that can be accessed by DEER measurements and the sensitivity of such measurements strongly depends on the phase relaxation of Gd(3+) chelates in frozen, glassy solutions. In this work, we explore the phase relaxation of Gd(3+)-DOTA as a representative of GdSL in temperature and concentration ranges typically used for W-band DEER measurements. We observed that in addition to the usual mechanisms of phase relaxation known for nitroxide based spin labels, GdSL are subjected to an additional phase relaxation mechanism that features an increase in the relaxation rate from the center to the periphery of the EPR spectrum. Since the EPR spectrum of GdSL is the sum of subspectra of the individual EPR transitions, we attribute this field dependence to transition dependent phase relaxation. Using simulations of the EPR spectra and its decomposition into the individual transition subspectra, we isolated the phase relaxation of each transition and found that its rate increases with |ms|. We suggest that this mechanism is due to transient zero field splitting (tZFS), where its magnitude and correlation time are scaled down and distributed as compared with similar situations in liquids. This tZFS induced phase relaxation mechanism becomes dominant (or at least significant) when all other well-known phase relaxation mechanisms, such as spectral diffusion caused by nuclear spin diffusion, instantaneous and electron spin spectral diffusion, are significantly suppressed by matrix deuteration and low concentration, and when the temperature is sufficiently low to disable spin lattice interaction as a source of phase relaxation.

The Northwick Park Heart Study: evidence from the laboratory

The Northwick Park Heart Study (NPHS) has shown associations of high plasma fibrinogen and factor VII (FVIIc) levels with the risk of death from coronary heart disease (CHD). The finding for fibrinogen has been confirmed in many other studies. Whereas one further study has found a similar prospective association for FVIIc, several have not. Experimental studies have demonstrated the impact that the coagulation activity of fibrinogen and FVIIc have on the progression and phenotype of atherosclerotic lesions. FVIIc-driven thrombin generation and fibrin formation within the vessel wall are important determinants of both plaque (in)stability and atherothrombosis. In blood, local concentrations of FVIIc and thrombin may be sufficient to allow interactions between these serine proteases and protease-activated receptors, to drive cellular inflammatory reactions that further promote these processes. Local fibrinogen concentrations dictate fibrin clot structure and resistance to fibrinolysis. Within the atherosclerotic plaque, coagulation reactions driven by proinflammatory stimuli may initially support lesion stability (as part of wound healing), but, with advanced inflammation, thrombin and fibrin generation diminish because of proteolytic activity contributing to plaque instability. The NPHS findings have proved controversial, but, in the light of current knowledge, a reappraisal of the importance of FVIIc and fibrinogen in atherosclerosis, atherothrombosis and CHD is justified. Hypercoagulability, reflected in turn by thrombin generation capacity, and local concentrations of coagulation proteins, including FVIIc and fibrinogen, is linked to plaque phenotype, and even minute local concentrations of fibrinogen and proteases such as FVIIc may affect thrombin generation capacity.

Navigating motherhood choices in the context of rheumatoid arthritis: women's stories

OBJECTIVE

Planning a family is a complex decision. For women with chronic conditions such as rheumatoid arthritis (RA), there are additional concerns about their own and their baby's health. This qualitative study examined women's experiences of negotiating their family decisions in the context of RA.

METHODS

A qualitative study was conducted in 14 women who provided a written account of their motherhood decisions and experiences. Those 'stories' were then thematically analysed.

RESULTS

RA was found to affect women's motherhood decisions and experiences. Three key themes were identified for both the process of decision making and the experience of that decision: capacity, uncertainty and acceptance. Only two of the women decided not to have children, while for others the decision centred on changing expectations from the number of children they planned to have, to parenting within the restrictions of their physical abilities.

CONCLUSION

While many women struggled through the negotiations of their motherhood choices, those who chose to have children reported great joy in that experience. The challenges faced by women with RA contemplating motherhood, however, highlight the need for understanding and support from health professionals and the provision of resources so that women can make informed choices.

Measuring perinatal mental health risk

The purpose of this review was to critically analyse existing tools to measure perinatal mental health risk and report on the psychometric properties of the various approaches using defined criteria. An initial literature search revealed 379 papers, from which 21 papers relating to ten instruments were included in the final review. A further four papers were identified from experts (one excluded) in the field. The psychometric properties of six multidimensional tools and/or criteria were assessed. None of the instruments met all of the requirements of the psychometric properties defined. Some had used large sample sizes but reported low positive predictive values (Antenatal Risk Questionnaire (ANRQ)) or insufficient information regarding their clinical performance (Antenatal Routine Psychosocial Assessment (ARPA)), while others had insufficient sample sizes (Antenatal Psychosocial Health Assessment Tool, Camberwell Assessment of Need-Mothers and Contextual Assessment of Maternity Experience). The ANRQ has fulfilled the requirements of this analysis more comprehensively than any other instrument examined based on the defined rating criteria. While it is desirable to recommend a tool for clinical practice, it is important that clinicians are made aware of their limitations. The ANRQ and ARPA represent multidimensional instruments commonly used within Australia, developed within large samples with either cutoff scores or numbers of risk factors related to service outcomes. Clinicians can use these tools, within the limitations presented here, to determine the need for further intervention or to refer women to mental health services. However, the effectiveness of routine perinatal psychosocial assessment continues to be debated, with further research required.

Male breast cancer: follow-up recommendations after surgery

Abstract #4130

Introduction: National Comprehensive Cancer Network (NCCN) guidelines for female breast cancer treatment and surveillance are well established, but data on male breast cancers are not collected. As an NCCN institution, our objective was to examine practice patterns and follow-up for male breast cancer.&#x2028; Methods: After IRB approval, a prospective breast database from 1990-2008 was queried for male patients. Medical records were examined for traditional factors (TNM, receptor status, treatment, gynecomastia) and follow-up practices such as mammogram use. Survival analysis was performed using the Kaplan-Meier method with 95% confidence intervals (CI) generated for 5-yr estimates. The logrank test was used to compare node positive/negative cohorts.&#x2028; Results: Of the 19,132 patients in the database, 71 (0.4%) were male; 64 had complete data. The median age for the 64 patients was 68.8yrs (range 29-85yrs). 89.1% presented with a palpable mass. 12.5% had gynecomastia in the cancer breast and 9.4% had contralateral gynecomastia. 18/64 (28.1%) had a familial history of breast, ovarian or colon cancer. One patient had bilateral synchronous breast cancer. Seven (10.9%) had previous prostate cancer and 4 (6.25%) had other synchronous cancers (2 papillary thyroid, 2 lung). Genetic testing was offered to all 64; 3 accepted. Two men had contralateral prophylactic mastectomy years later. The mean/median invasive tumor size was 2.0/1.6cm (range 0.0-10.0cm) and all but 2 tumors were ductal. 63 had a mastectomy (65.1% with axillary node dissection; 34.9% with sentinel lymph node biopsy). Lymph node involvement occurred in 25/64 (39.1%). Under NCCN guidelines, 49/64 (76.6%) should receive chemotherapy and chest wall radiation should be given to 27/64 (42.2%) based on tumor size and nodal status. Chemotherapy was offered to 50.0%; 35.9% received chemotherapy. Chest wall radiation was given in 59.3%. 63/64 were ER positive; 49 (77.8%) received hormone therapy. Follow-up annual mammograms were obtained in 27/64 (42.2%)[all BIRADs 1 or 2], not obtained in 28/64 (43.8%), and unknown in 9/64 (14.0%). Median follow-up was 26.1mos (range: 0.26-377.8mos). The 5-yr survival estimates and 95% CI for node positive and negative diseases were 75% (95% CI=46-90%) and 93% (95% CI=74-98%) respectively. For comparison, 5-yr survival rates from the NSABP B-04 trial were 60% in node-positive and 75% in node-negative disease. Four patients (6.3%) died of disease; 10 (15.6%) are alive with distant disease; 47 (73.4%) have no evidence of disease; and 3 (4.7%) are unknown or dead of other causes. There were 2 local recurrences (3.1%) [1 chest wall, 1 in-breast] and no metachronous contralateral breast cancer development. Conclusions: Male breast cancer is uncommon, as is contralateral breast cancer. Men were less likely to receive/accept chemotherapy/hormone therapy/genetic testing/annual mammograms and more likely to receive radiation based on NCCN guidelines, but survival compared to historic females was no worse. Creation of follow-up guidelines for males may be different than females.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4130.

The Emerging Risk Factors Collaboration: analysis of individual data on lipid, inflammatory and other markers in over 1.1 million participants in 104 prospective studies of cardiovascular diseases

Many long-term prospective studies have reported on associations of cardiovascular diseases with circulating lipid markers and/or inflammatory markers. Studies have not, however, generally been designed to provide reliable estimates under different circumstances and to correct for within-person variability. The Emerging Risk Factors Collaboration has established a central database on over 1.1 million participants from 104 prospective population-based studies, in which subsets have information on lipid and inflammatory markers, other characteristics, as well as major cardiovascular morbidity and cause-specific mortality. Information on repeat measurements on relevant characteristics has been collected in approximately 340,000 participants to enable estimation of and correction for within-person variability. Re-analysis of individual data will yield up to approximately 69,000 incident fatal or nonfatal first ever major cardiovascular outcomes recorded during about 11.7 million person years at risk. The primary analyses will involve age-specific regression models in people without known baseline cardiovascular disease in relation to fatal or nonfatal first ever coronary heart disease outcomes. This initiative will characterize more precisely and in greater detail than has previously been possible the shape and strength of the age- and sex-specific associations of several lipid and inflammatory markers with incident coronary heart disease outcomes (and, secondarily, with other incident cardiovascular outcomes) under a wide range of circumstances. It will, therefore, help to determine to what extent such associations are independent from possible confounding factors and to what extent such markers (separately and in combination) provide incremental predictive value.

WISDOM: history and early demise - was it inevitable?

In 1989, the UK Medical Research Council (MRC) agreed that, if feasible, a randomized controlled trial to assess the long-term risks and benefits of hormone replacement therapy (HRT) was a priority. Feasibility work began in 1990 and demonstrated that a large-scale multicenter trial was possible. An application for funding for a main trial was submitted to MRC in 1993 and, after extensive review, funding was released in late 1996. Set-up work for the trial - the Women's International Study of long Duration Oestrogen after Menopause (WISDOM) - began in 1997 with recruitment in 1999. In October 2002, following the early discontinuation of one arm of the US Women's Health Initiative HRT trial, the MRC decided to stop the WISDOM trial. This article, by the principal UK investigators of WISDOM, sets out the background and history of the trial.

Use of personal medical records for research purposes

The established practice of doctors using medical records for research purposes is threatened by the recent proposed guidelines from the Department of Health, the BMA, and the European Commission. The European Commission has proposed that explicit consent should be obtained from each patient before his or her medical records can be used; the proposals from the Department of Health and the BMA would require all research that needs access to personal medical records to be submitted to an ethics committee. We believe that these proposals would seriously impair an entire category of research and suggest therefore that another set of guidelines, proposed by a Royal College of Physicians' working group, should be used to modify the proposals. The guidelines of the working group encourage the use of medical records for research and ensure that such use can be made in a confidential manner without causing harm.

Knee joint contact pressure decreases after chronic meniscectomy relative to the acutely meniscectomized joint: a mechanical study in the goat

Several studies have shown that meniscectomy causes an immediate, acute increase in knee joint contact pressure and that changes in pressure distribution cause remodeling of bone and soft tissue. Presumably, this remodeling in turn affects contact pressures. This study tested the hypothesis that medial compartment contact pressure increases immediately after medial meniscectomy and then decreases with time. Supporting hypotheses regarding medial compartment contact area and lateral compartment pressures also were tested. Unilateral medial meniscectomy was performed on seven adult goats. Four or 8 months later, contact pressure and area were measured in vitro in the involved joints, as well as in the contralateral joints, before and after removal of the meniscus. The medial compartment pressures of the chronically meniscectomized joints were significantly less than those of the acutely meniscectomized paired joints but remained significantly greater than those of the intact joints. For the 4 and 8 month groups combined, the mean pressures of the acutely and chronically meniscectomized joints were greater than the pressures of the paired intact joints by 70 and 42%, respectively. The mean medial compartment contact areas of the acute and chronic joints were lower than those of the intact joints by 60 and 50%, respectively; mean lateral compartment pressures remained the same. This study indicates that joint remodeling reduces joint contact pressures. It also suggests that the effectiveness of a treatment to reduce pressure concentrations may be determined only by comparison, at the same postoperative time, of the pressure with that of the chronically meniscectomized joint, since pressures decreased with time without treatment.

Emergency hospital admissions and readmissions of patients aged over 75 years and the effects of a community-based discharge scheme

This paper reports the results of a retrospective review which analysed emergency admissions and readmissions of elderly patients to a district general hospital. All patients received standard after-care allocated by the community health and social services departments following referral by hospital staff. In addition, half of the cohort was randomly allocated to receive care attendant support for a maximum of 12 hours a week for two weeks following the first and any subsequent discharge from hospital. The effect of this additional community support on emergency readmissions was also reviewed. The findings show that the patients randomly allocated to receive the modest domiciliary after-care service were less likely to have another emergency readmission or multiple readmissions. The results suggest that patients over 75 years-of-age, living alone, or having two or more emergency admissions within six months, should have a domiciliary assessment and follow-up after hospital discharge.

A common genetic polymorphism associated with lower coagulation factor VII levels in healthy individuals

We have identified a genetic polymorphism of factor VII that is strongly associated with plasma factor VII coagulant activity (factor VIIc) in healthy individuals from the United Kingdom. This polymorphism was detected after Msp I digestion of polymerase chain reaction-amplified genomic DNA. In a sample of 284 men, the frequency of the M2 allele (loss of cutting site) is 0.1, and individuals with the M1M2 genotype have factor VIIc levels 22% below the sample mean (p less than 0.0001). Msp I genotype was found to be the strongest predictor of factor VIIc, accounting for 20.2% of the variance, with cholesterol accounting for an additional 3.5%. The base change that gives rise to the Msp I polymorphism is a G-to-A substitution in the codon for amino acid 353, leading to replacement of arginine (Arg) with glutamine (Gln) in the protein product of the M2 allele (designated Gln 353). Three individuals homozygous for the M2 allele have both low factor VIIc and low factor VII protein concentrations. The conformation of the Gln 353 molecule may be different from that of the Arg 353 protein, affecting its intracellular processing, secretion, turnover in plasma, or activity. In view of its association with lower factor VIIc levels, possession of the M2 allele may confer protection against thrombosis and myocardial infarction.

Restriction fragment length polymorphisms of the apolipoprotein A-I, C-III, A-IV gene locus. Relationships with lipids, apolipoproteins, and premature coronary artery disease

Data from various laboratories have indicated associations of various alleles determined by RFLPs within or adjacent to several apolipoprotein genes with abnormalities in plasma lipids and/or premature coronary artery disease (CAD). In order to assess such relationships we have examined allele frequencies of 8 different RFLPs within or adjacent to the apo A-I, C-III and A-IV gene complex on the long arm of chromosome 11 (MspI, 5' to the apo A-I gene; MspI, within the apo A-I gene; PstI, 3' to the apo A-I gene; SstI, 3' to the apo C-III gene; PvuII, within the apo C-III gene; PvuII, 5' to the apo C-III gene; XbaI, within the apo A-IV gene; and XbaI, 3' to the apo A-IV gene) in 202 patients with CAD (50% narrowing of one or more coronary arteries) prior to age 60 and 145 normal controls. None of the allele frequencies of these RFLPs were significantly different in cases as compared to controls. With regard to associations with plasma lipids and apolipoprotein levels, the rare allele determined by the absence of the PstI site was associated with elevated triglyceride levels (P less than 0.05) in cases, but not in controls. In contrast, the rate MspI allele 5' to the apo A-I gene was associated with elevated triglyceride levels (P less than 0.05) in controls but not in cases. In both cases and controls, subjects with the uncommon SstI allele had triglyceride levels that were 9 and 38% higher than in those without this allele. These differences were significant (P less than 0.05) only in controls. Our data indicate that the rare allele determined by the SstI site within this gene complex deserves further study in order to understand its association with elevated triglycerides in Caucasian populations. However, at the present time all these DNA markers lack sufficient specificity to be clinically useful for CAD risk assessment.

DNA polymorphisms of the apolipoprotein B gene in patients with premature coronary artery disease

Elevated plasma levels of low density cholesterol and their major apolipoprotein (apo B) are associated with an increased risk of coronary artery disease (CAD). We have examined allele frequencies of restriction fragment length polymorphisms (RFLP) of the apo B gene in 111 male Caucasians with premature CAD (mean age 49 +/- 7 years) and in 122 elderly Caucasian males (mean age, 73 +/- 5 years), free of clinical cardiovascular disease. The rare allele (R1) of the EcoR1 RFLP in exon 29, resulting in an amino acid change (Glu----Lys4154) was seen more frequently in CAD than in controls (0.270 vs 0.207, P less than 0.05). The R1 RFLP and the MspI insertion polymorphisms (MI) within the 3' hypervariable region (HVR) were observed together in 87% and are likely in linkage disequilibrium. The MI RFLP were slightly more frequent in CAD than control (0.239 vs. 0.211, P = 0.08). A second MspI RFLP in exon 26 results in an amino acid change (Arg----Glu3611); the rare allele M2 was seen more frequently in patients than in controls (0.150 vs. 0.057, P less than 0.005). No significant differences in allele frequencies were observed for the Xba1 RFLP in exon 26 (0.500 vs. 0.529, P = ns) or for the PvuII RFLP near the 5' end (P2) (0.105 vs. 0.088, P = ns). No statistically significant differences in lipid, lipoprotein cholesterol or apolipoproteins A-I and B were observed in patients or in controls. Two of the RFLPs examined (R1 and M2) result in changes in amino acid sequence and their allele frequencies are increased in CAD cases when compared with controls. Genetic variability within the apo B gene may thus contribute to cardiovascular risk. The physiological effects of individual mutations within apo B remain to be determined. It is unlikely, however that the single site polymorphisms examined in this study, will impart further information about CAD risk than conventional lipid parameters.

Effect of dietary ascorbic acid on the susceptibility of steelhead trout (Salmo gairdneri) to nitrite toxicity

Four diets, each containing different levels of ascorbic acid were fed to duplicate groups of steelhead trout (Salmo gairdneri) in two four-week periods. Tolerance to nitrites increased when the concentration of ascorbic acid was high. Flow-through bioassays in fingerlings showed that when the temperature increased the percent of methemoglobin in their blood also increased. The tolerance to nitrite toxicity was less in large fish than in those smaller fed the same concentration of ascorbic acid. Possibly ascorbic acid acts in the reduction of methemoglobin to hemoglobin, and also it has a protective effect against stress in the fish. A "safe" level of 200 mg/kg of ascorbic acid in practical diets was reached.

Design problems in research on rehabilitation after brain damage

This paper is based on a report to the Committee on Coordination of Research into Rehabilitation after Closed Head Injury and Stroke, sponsored by the Medical Research Council (MRC). A review is presented of some of the most important factors to be considered in rehabilitation studies, drawing attention to some of the more common pitfalls.

Comparison of variability of different methods of measuring fibrinolytic activity

The Northwick Park Heart Study has drawn attention to the variability, especially within-person, of the dilute blood clot lysis time (DBCLT). However, this method has considerable practical advantages in large-scale surveys. The variability of DBCLT has therefore been compared with that of the euglobulin lysis time (ELT) and the euglobulin fibrin plate area (EFPA). Each measurement has been made 10 times over a 9 month period in each of 12 healthy people; fibrinogen levels have also been measured. As expected, highly significant correlations (r) have been obtained between the three methods: DBCLT and ELT, + 0.63; DBCLT and EFPA, - 0.47; ELT and EFPA, - 0.54 (P<0.001 in each case). The between-person variance, distinguishing one person from another, accounts for 60% of the total variance in DBCLT, 35% in ELT and 10% in EFPA. For fibrinogen, the value is nearly 90%. The rest of the variance in each case is accounted for by biological within-person variation and laboratory error. Thus, while DBCLT is a variable method of determining an individual’s characteristic level of fibrinolytic activity, it is probably less so than other commonly used methods. The results of this experiment suggest that a previous estimate of the within-person variability of DBCLT (Meade and North, 1977, British Medical Bulletin, 33, 283) may have been too high.