Progression of carotid intima-media thickness in patients treated with lipoprotein apheresis: real-world evidence over 12 years

Background

The extent of intervention effects on carotid intima-media thickness (CIMT) can predict the degree of atherosclerotic cardiovascular disease (ASCVD) risk reduction. There is limited evidence of long-term effects of lipoprotein apheresis on the CIMT progression.

Purpose

We hypothesized that regular lipoprotein apheresis over the course of 10 years may slow down progression of CIMT in patients with severe hypercholesterolemia.

Methods

This case series describes ten Caucasian patients (mean age 60±9 years, 70% female, 80% statin intolerant) with familial hypercholesterolemia and/or hyperlipoproteinemia(a) treated with lipoprotein apheresis at a single academic center between 2005 and 2020. The mean and maximum diastolic CIMT of the distal 1 cm of the far wall of the right and left common carotid arteries was measured by the same, trained sonographer utilizing an automated border-detection algorithm.

Results

The median pre-treatment low-density lipoprotein cholesterol (LDL-C) level was 214 mg/dL (95% confidence interval, 145 to 248), lipoprotein(a), 26 mg/dL (15 to 109; 40% with lipoprotein(a) >60 mg/dL). Using the imputed trajectories, period-specific on-treatment time-weighted averages for LDL-C and lipoprotein(a) were 141 mg/dL (IQR, 89 to 152) and 24 mg/dL (IQR, 12 to 119), respectively. The baseline mean CIMT was 850±170μm and maximum CIMT was 1040±220μm across the age range of 46 to 70 years. Over a median duration of 12 years, regular treatment with lipoprotein apheresis resulted in an average reduction in the mean CIMT of −40μm (IQR, −50 to 20) and maximum CIMT −30μm (IQR, −60 to −10). Among tested lipid and lipoprotein fractions in this sample, the follow-up mean CIMT values strongly correlated only with the baseline lipoprotein(a) levels. Median CIMT progression rates were as follows: mean common carotid, −4μm/y (IQR, −9 to 1), mean common carotid, −12μm/3y (IQR, −26 to 4), maximal common carotid, −3μm/y (IQR, −8 to −1). This translated into 70% (7/10) of cases demonstrating composite mean CIMT below their expected chronologic age, gender and race-stratified vascular age. There was a strong direct correlation between the mean CIMT value at the end of the treatment period and the age of treatment initiation. In this cohort of primary and secondary prevention of patients with severe hypercholesterolemia, the overall rate of ASCVD was 37.5 per 1000 person-years while on lipoprotein apheresis.

Conclusions

Our observation performed in the clinical setting, demonstrated a real-world effectiveness of lipoprotein apheresis. This analysis supports implementation of aggressive lipid-modifying strategies across all ages. Surveillance with CIMT allows for continued monitoring of atherosclerosis progression and increases compliance with the lipid-modifying therapies in the high-risk patients with poor statin tolerance in the clinical setting.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): KUMC

The accuracy of pre-operative (P)-POSSUM scoring and cardiopulmonary exercise testing in predicting morbidity and mortality after pancreatic and liver surgery: A systematic review

Background

Cardiopulmonary exercise-testing (CPET) and the (Portsmouth) Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity ((P)-POSSUM) are used as pre-operative risk stratification and audit tools in general surgery, however, both have been demonstrated to have limitations in major hepatopancreatobiliary (HPB) surgery.

Materials and methods

The aim of this review is to determine if CPET and (P)-POSSUM scoring systems accurately predict morbidity and mortality. Eligible articles were identified with an electronic database search. Analysis according to surgery type and tool used was performed.

Results

Twenty-five studies were included in the final review. POSSUM predicted morbidity demonstrated weighted O/E ratios of 0.75(95%CI0.57–0.97) in hepatic surgery and 0.85(95%CI0.8–0.9) in pancreatic surgery. P-POSSUM predicted mortality in pancreatic surgery demonstrated an O/E ratio of 0.75(95%CI0.27–2.13) and 0.94(95%CI0.57–1.55) in hepatic surgery. In both pancreatic and hepatic surgery an anaerobic threshold(AT) of between 9 0.5–11.5 ml/kg/min was predictive of post-operative complications, and in pancreatic surgery ventilatory equivalence of carbon dioxide(˙VE/˙VCO2) was predictive of 30-day mortality.

Conclusion

POSSUM demonstrates an overall lack of predictive fit for morbidity, whilst CPET variables provide some predictive power for post-operative outcomes. Development of a new HPB specific risk prediction tool would be beneficial; the combination of parameters from POSSUM and CPET, alongside HPB specific markers could overcome current limitations.

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Current pre-operative scoring for pancreatic and liver surgery is inaccurate.

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In pancreatic and liver surgery anaerobic threshold scores were predictive of complications.

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In pancreatic surgery ventilatory equivalence of carbon dioxide was predictive of mortality.

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P-POSSUM is inaccurate for predicting mortality and morbidity in pancreatic surgery.

Bioelectrical impedance analysis (BIA)-derived phase angle (PA) is a practical aid to nutritional assessment in hospital in-patients

BACKGROUND

Nutritional status can be difficult to assess. Bioelectrical impedance analysis (BIA)-derived phase angle (PA), and the plasma markers citrulline and transthyretin (pre-albumin) have the potential to assist, but the protocol of fasting and resting for BIA renders the investigation impractical for routine use, especially so in populations at high risk of malnutrition.

AIMS

1 To clarify whether starving and resting are necessary for reliable measurement of PA. 2 To identify whether PA, citrulline and transthyretin correlate with nutritional status.

METHODS

Eighty consenting adult in-patients were recruited. Nutritional status was determined by subjective global assessment (SGA) used as gold standard. The Malnutrition Universal Screening Tool (MUST) was used and anthropometric measurements were performed. Serum was analysed for citrulline and transthyretin. PA was measured using Bodystat 4000. The PA was considered to define malnutrition when lower than reference ranges for sex and age, and severe malnutrition if more than 2 integers below the lower limit. Anthropometric measurements were categorised according to WHO reference centiles. Ordinal logistic regression estimated the strength of association of PA, citrulline and transthyretin with SGA. PA values in the different metabolic states were compared using paired t tests.

RESULTS

All 80 subjects completed the BIA and the nutritional assessments in the 3 different states; 14 declined to provide blood samples for the biochemical assays. Malnutrition was identified in 32 cases, severe malnutrition in 14 cases, the remaining 34 cases were deemed not to be malnourished. PA was strongly inversely associated with SGA (Odds Ratio [OR] per unit increase = 0.21, CI 0.12-0.37, p < 0.001). PA was not influenced by exercise (p = 0.134) or food intake (p = 0.184). Transthyretin was inversely associated with malnourished/severely malnourished states (OR = 0.98, 95% CI 0.97-0.99, p = 0.001), but had poorer predictive values than PA. There was no significant association between citrulline concentration and SGA (OR = 1.01, 95% CI 0.99-1.04, p = 0.348).

CONCLUSIONS

The BIA-derived PA reliably identifies malnutrition. It is strongly associated with SGA but requires less skill and experience, and out-performs circulating transthyretin, rendering it a promising and less operator-dependent tool for assessing nutritional status in hospital patients. Our novel demonstration that fasting and bed-rest are unnecessary consolidates that position.

Vitamin D deficiency in Malawian adults with pulmonary tuberculosis: risk factors and treatment outcomes

SETTING: Vitamin D deficiency is common in African adults with tuberculosis (TB), and may be exacerbated by the metabolic effects of anti-tuberculosis drugs and antiretroviral therapy (ART). It is unclear whether vitamin D deficiency influences response to anti-tuberculosis treatment.

OBJECTIVES: To describe risk factors for baseline vitamin D deficiency in Malawian adults with pulmonary TB, assess the relationship between serum 25-hydroxy vitamin D (25[OH]D) concentration and treatment response, and evaluate whether the administration of anti-tuberculosis drugs and ART is deleterious to vitamin D status during treatment.

DESIGN: A prospective longitudinal cohort study.

RESULTS: The median baseline 25(OH)D concentration of the 169 patients (58% human immunodeficiency virus [HIV] infected) recruited was 57 nmol/l; 47 (28%) had vitamin D deficiency (<50 nmol/l). Baseline 25(OH)D concentrations were lower during the cold season (P < 0.001), with food insecurity (P = 0.034) or in patients who consumed alcohol (P = 0.019). No relationship between vitamin D status and anti-tuberculosis treatment response was found. 25(OH)D concentrations increased during anti-tuberculosis treatment, irrespective of HIV status or use of ART.

CONCLUSIONS: Vitamin D deficiency is common among TB patients in Malawi, but this does not influence treatment response. Adverse metabolic effects of drug treatment may be compensated by the positive impact of clinical recovery preventing exacerbation of vitamin D deficiency during anti-tuberculosis treatment.

Evidence of thymic reconstitution after highly active antiretroviral therapy in HIV-1 infection

OBJECTIVES

We aimed to provide evidence of thymic reconstitution after highly active antiretroviral therapy (HAART) in HIV-1 infected patients and to correlate this with the restoration of peripheral naïve T cells.

METHODS

Positron emission tomography (PET) enables definitive evidence of thymic activity, indicating functional potential. In this case study, a single patient who initiated HAART demonstrated reconstitution of the naïve T-cell pool and underwent thymic PET scans at baseline and 2 and 6 months following initiation of therapy. Two patients who failed to demonstrate such reconstitution acted as controls. These patients (mean age 27 years) had chronic HIV infection with low CD4 T-cell counts (mean 82, range 9-160 cells/microL blood). Increased function of the thymus visualized by PET was correlated with phenotypic changes in CD4 and CD8 T cells in the periphery measured by flow cytometry, and with numbers of recent thymic emigrants measured by quantification of the numbers of T-cell receptor excision circles (TRECs) in peripheral cells.

RESULTS

In one patient, clear correlations could be drawn between visible activity within the thymus, as measured by increased [F18]fluorodeoxyglucose (FDG) uptake, and regeneration of naïve CD4 (CD45RA/CD62L) T cells, increased numbers of CD4 T cells, controlled viraemia and increased numbers of recent thymic emigrants. A second patient displayed no increase in peripheral CD4 count and no increase in thymic activity. The third patient elected to stop therapy following the 2-month time point.

CONCLUSIONS

The use of PET suggests that thymic activity may increase after HAART, indicating that the thymus has the potential to be functional even in HIV-1 infected persons with low CD4 T-cell counts.

Catecholamine responses to high intensity cycle ergometer exercise: Body mass or body composition?

The purpose of this study was to compare the sympathoadrenergic and metabolic responses following 30 s of maximal high intensity cycle ergometry exercise when cradle resistive forces were derived from total-body mass (TBM) or fat-free mass (FFM). Increases in peak power output (PPO) and pedal velocity were recorded when resistive forces reflected FFM (953 +/- 114 W vs 1020 +/- 134 W; 134 +/- 8 rpm vs 141 +/- 7 rpm ; P < 0.05). No differences were observed between mean power output (MPO), fatigue index (FI%), work done (WD) or heart rate (HR) when the TBM and FFM protocols were compared. There were no differences between the TBM and FFM protocols for adrenaline (A), noradrenaline (NA) or blood lactate concentrations ([La-]B) recorded at rest, immediately post or 24 h post exercise. However, increases in blood concentrations of A and NA (P < 0.05) were recorded for both the TBM and FFM protocol immediately post exercise. Significant correlations (P < 0.05) were recorded between PPOs, immediate post- exercise NA and [La-]B for both the TBM and FFM protocols. [La-]B levels were also significantly elevated (P < 0.01) immediately post exercise for both the TBM and FFM protocols. The results from this study suggest that greater peak power outputs are obtainable with no subsequent differences in neurophysiological or metabolic stress as determined by plasma A, NA and [La-]B concentrations when resistive forces reflect FFM and not TBM during loading procedures. The findings also indicate that immediate post exercise concentrations return to resting levels 24 h post exercise.

Dual X-ray absorptiometry detects disease- and treatment-related alterations of bone density in prostate cancer patients

Metastatic bone disease is an important clinical problem which has proven difficult to study because of a lack of noninvasive investigative modalities. Here we show that dual-energy X-ray absorptiometry (DXA) scanning provides clinically useful information about the status of metastatic bone lesions in cancer patients undergoing palliative treatment. In the study group of 21 patients, a significant increase in metastatic bone mineral density (BMD) was confirmed in prostate (n = 14) relative to breast (n = 7) cancer patients. With respect to the prostate cancer cohort, further increases in lesional BMD were evident in all evaluable patients in whom biochemical progression occurred; conversely, lesional BMD declined in patients who had a partial response to therapy. BMD of uninvolved bone decreased with all types of androgen-deprivation therapy regardless of whether patients responded or relapsed. We conclude that BMD changes in both lesional and uninvolved bone are readily detectable in metastatic prostate cancer, and propose that DXA scanning represents a promising new approach to monitoring the natural history and therapeutic course of this disease.

Urinary catecholamine excretion in relation to renal function

The urinary excretions of the free catecholamines noradrenaline, adrenaline and dopamine were measured in 50 patients (33 men and 17 women) with chronic renal failure. Stability studies showed that the catecholamines were stable in unacidified urine as long as the pH was not greater than 7.5 and the urine was acidified within 2-3 h of collection. The outputs of noradrenaline and dopamine correlated positively with creatinine clearance and in patients with clearances above 40 mL/min were similar to those in healthy volunteers (n = 20). However, adrenaline output was not correlated with creatinine clearance although it was lower in patients with renal failure compared with healthy volunteers. The urinary free catecholamine output during the first 10 days after a renal transplant was significantly less than normal, presumably because renal function was still impaired. However, in patients treated with cyclosporin A (CyA) combined with prednisolone the catecholamine excretion was lower compared with those treated with CyA and azathioprine. Impairment in renal function can have a marked effect on the output of free catecholamines and must be borne in mind when interpreting values that may have pathological significance.

Bias due to incomplete follow up in a cohort study

AIM

To investigate the bias introduced by incomplete follow up in a cohort study of ocular outcome after premature birth.

METHODS

A geographically defined cohort of children born before 32 weeks' gestation was prospectively recruited at birth to study the ocular outcome at 2 years. On the basis of attendance at 2 years, the children's families were allocated to one of three groups: group 1 attended for follow up, group 2 were difficult to trace, and group 3 were very reluctant for assessment. All children were examined by a single ophthalmologist, masked to these groupings.

RESULTS

558 children (98.8% of study group) were examined, of whom 505 were in group 1, 20 in group 2, and 33 in group 3. The groups which were more difficult to study (groups 2 and 3) showed a significantly higher prevalence of ocular abnormalities, including strabismus (p=0. 02) and cicatricial retinopathy of prematurity (p=0.002) compared with those attending for follow up. Further, not all of these cases could have been identified by review of the children's previous records. Ocular abnormalities would be underestimated by 16% (11.3% in group 1 compared with 13.4% in the total cohort, p=0.77).

CONCLUSIONS

This study suggests that the prevalence of abnormalities would be underestimated by incomplete follow up, as those subjects who were most difficult to obtain for study had a significantly higher prevalence of abnormalities.

Risk factors for strabismus in children born before 32 weeks' gestation

AIM

To investigate risk factors associated with strabismus in children born prematurely.

METHODS

Prospective study of all children born before 32 weeks' gestation between 1 January 1990 and 31 December 1991 in a geographically defined population of approximately 3 million in the Northern Region of the United Kingdom. All children were examined aged 2 years by the same ophthalmologist and paediatrician.

RESULTS

558 children (98.6% of study group) were examined. Logistic regression showed an increased risk of strabismus in children with cicatricial retinopathy of prematurity (p=0.02), refractive error (p=0.003), family history of strabismus (p<0.0001), and poor neurodevelopmental outcome (p<0.0001), in particular impaired locomotor skills (p=0.008) and hand-eye coordination (p=0. 001). Gestational age and regressed acute ROP were not independent risk factors for strabismus (p=0.92 and 0.85 respectively).

CONCLUSIONS

This study has identified factors which are independently related to strabismus (although not necessarily causative) and others which are related only indirectly. This may contribute both to the management of children born prematurely and to future studies of the aetiology of strabismus.

Urinary excretion of pyridinium crosslinks in healthy 4-10 year olds

Urinary pyridinoline and deoxypyridinoline, pyridinium crosslinks released during breakdown of mature collagen, might serve as useful markers of bone resorption. Before their role can be identified, reference values must be established. In this study, free pyridinoline (f-Pyr), free deoxypyridinoline (f-DPyr), and creatinine (Cr) were measured in first morning void urine samples from 250 girls and 265 boys between the ages of 4 and 10 years. Overall, there was a decrease in f-Pyr:Cr and f-DPyr:Cr ratios with increasing age in both sexes, but there was a wide range of values for individuals of similar ages. Further studies are required to assess whether urinary pyridinium crosslink excretion is sufficiently deranged in conditions affecting bone metabolism for the measurement of these compounds to be of clinical value.

Evaluation of a new method for the analysis of free catecholamines in plasma using automated sample trace enrichment with dialysis and HPLC

BACKGROUND

Analysis of urinary free catecholamines was automated recently, but analysis of plasma samples posed special difficulties. The present study was undertaken to evaluate a new method for the automated analysis of plasma catecholamines.

METHODS

The procedure is based on an improved sample handling system that includes dialysis and sample clean-up on a strong cation trace-enrichment cartridge. The catecholamines norepinephrine, epinephrine, and dopamine are then separated by reversed-phase ion-pair chromatography and quantified by electrochemical detection.

RESULTS

Use of a 740- microL sample is required to give the catecholamine detection limit of 0.05 nmol/L and analytical imprecision (CV) between 1.1% and 9.3%. The assay can be run unattended, although >12 h of analysis time is not recommended without cooling of the autosampler rack. Comparison (n = 68) of the automated cation-exchange clean-up with the well-established manual alumina procedure gave excellent agreement (mean, 3.78 +/- 2.76 and 3.8 +/- 2.89 nmol/L for norepinephrine and 0.99 +/- 1.72 and 1.08 +/- 1.78 nmol/L for epinephrine). Hemodialysis had no clear effect on plasma norepinephrine. Epinephrine concentrations were similar (0.05 < P < 0.1) in chronic renal failure patients (0.24 +/- 0.3 nmol/L; n = 15) and healthy controls (0.5 +/- 0.24 nmol/L; n = 31). Dopamine was not quantified, being usually <0.2 nmol/L.

CONCLUSION

The availability of such a fully automated procedure should encourage the more widespread use of plasma catecholamine estimation, e.g., after dialysis, exercise, or trauma/surgery and in the investigation of catecholamine-secreting tumors, particularly in the anuric patient.

Pre-dialysis serum albumin is a poor indicator of nutritional status in stable chronic haemodialysis patients

The correlation between pre-dialysis serum albumin and mortality has been linked with malnutrition. We measured pre and post-dialysis albumin in 86 stable haemodialysis patients and compared them with anthropometric measurements and body mass index (BMI). On the basis of pre-dialysis albumin 13% of patients would be classified as high risk, whilst on the basis of post-dialysis albumin only 12% would be classified as high risk. Change in albumin could be predicted by fluid removal during haemodialysis. Pre-dialysis albumin correlated weakly with mid upper arm circumference (MUAC). Post dialysis albumin correlated with MUAC and triceps skin fold thickness (TSF). There was a weak negative correlation between age and post-dialysis albumin. TSF strongly correlated with MUAC and BMI. Pre-dialysis albumin appears to be a poor predictor of nutritional status and does not correlate well with other nutritional parameters. The excess risk of death associated with a low pre-dialysis albumin may be related to fluid overload rather than malnutrition.

Usefulness of pindolol in neurocardiogenic syncope

We prospectively studied the efficacy of pindolol, a beta-adrenergic blocker with intrinsic sympathomimetic activity (ISA), for the prevention of syncope recurrences in 31 patients with recurrent neurocardiogenic syncope. Pindolol proved to be an effective treatment, even in patients who had previously failed treatment with conventional beta blockers, suggesting a clinical benefit from addition of ISA to beta blockade in this setting.

The incorporation of lamotrigine into the routine automated sequential trace enrichment of dialysates assay of anticonvulsants

We have extended automated sequential trace enrichment of dialysates and high performance liquid chromatography to include the simultaneous assay of lamotrigine with other anticonvulsant drugs: phenobarbitone, carbamazepine and phenytoin. The procedure is reliable and precise (between-batch coefficients of variation < 2.8%) with no interference from other commonly prescribed drugs. Patients on lamotrigine presented with serum concentrations up to 67 mumol/L with no adverse effects, suggesting that the therapeutic range may need re-appraisal.

Refractive errors in children born before 32 weeks gestation

PURPOSE

To document the refractive errors in a cohort of children born before 32 weeks gestation.

METHODS

All children born before 32 weeks gestation between 1 January 1990 and 31 December 1991 to mothers resident in the Northern Region of the National Health Service were examined at 2 years old (n = 558).

RESULTS

Stage 3 or worse retinopathy of prematurity (ROP) was associated with myopia. In those not developing stage 3 or worse ROP, the refractive errors were myopia in 1.5%, hypermetropia > 4 dioptres (D) in 5.4%, anisometropia > 1 D in 1.1% and astigmatism > 1.25 D in 5.7%.

CONCLUSION

The incidence of refractive errors in those not developing stage 3 or worse ROP was similar to that in the general population.

The performance of an infra-red interactance instrument for assessing total body fat

Infra-red interactance has been evaluated as a technique for measuring total body fat in comparison with a range of alternative methods. The alternative techniques employed were neutron activation analysis, tritiated water dilution, whole-body potassium-40 counting, skinfold anthropometry, bioelectrical impedance analysis and the body mass index. The study group consisted of 43 healthy adults (16 males and 27 females). For 11 women, measurements were obtained before and after 11 weeks on a very low-calorie diet, giving a total of 54 sets of data. Correlation coefficients between infra-red interactance and the other techniques varied between 0.58 (p < 0.0002) and 0.80 (p < 0.0001) for females, and between 0.64 (p < 0.009) and 0.94 (p < 0.0001) for males. The average fat for the study group was underestimated by 15% using infra-red interactance in comparison with the average fat obtained from the other techniques. It was also noted that the infra-red interactance instrument yielded a very narrow range of body fats in females in comparison with the other techniques. It is essential that these differences are reconciled before infra-red interactance takes a significant role in body composition analysis.

Audit of 6 years' experience of breast fine needle aspiration (FNA) cytology using the cytospin method; improvement through multidisciplinary clinical audit

A breast FNA cytology service for palpable breast lumps was commenced in 1989 using the cytospin method. Over the following 6 years 2314 aspirates were received. The results were audited in detail in 1990, 1991/1992 and 1994. Multidisciplinary clinical audit meetings followed each audit cycle. Practice change was agreed after each audit. Each audit cycle was followed by demonstrable improvement in the complete sensitivity of the technique, being respectively 79%, 88% and 96%. The cytospin method is a viable alternative to the conventional smear method.

Reliability of rectal biopsy in distinguishing between chronic inflammatory bowel disease and acute self-limiting colitis

AIMS

In order to assess the validity of previously proposed criteria for the differentiation of chronic inflammatory bowel disease (CIBD) from acute self-limiting colitis (ASLC) all rectal biopsies were reported by a single histopathologist with a long-term gastrointestinal interest over a 4.5-year period.

METHODS AND RESULTS

The presence or absence of distorted crypt architecture, increased lymphocytes and plasma cells, villous mucosal architecture, granulomata, basal lymphoid aggregates, basal giant cells and Paneth cell metaplasia was noted for each biopsy. The definite presence of any of the above features, with the exception of intramucosal granulomata, was regarded as indicative of CIBD. Eighteen months later all available case notes were examined and the presenting clinical symptoms and working clinical diagnosis extracted. The final diagnosis, histopathological diagnosis and the presence or absence of any of the above histopathological features were correlated and the positive predictive value of each histopathological feature was calculated. A correct diagnosis of either CIBD or ASLC was made in 80 of 84 and 29 of 31 cases, respectively.

CONCLUSIONS

Villous mucosal architecture and Paneth cell metaplasia were found to be specific features of CIBD. Distorted crypt architecture, basal lymphoid aggregates and plasma cell infiltration of the lamina propria were also useful features but strict definition of these features is required and discussed. Intramucosal epithelioid granulomas were identified in eight cases of CIBD and four cases of ASLC. In association with ruptured crypts intramucosal granulomas are not specific features of Crohn's colitis.

Estimating social adjustment following spinal trauma--II: Population trends and effects of compensation on adjustment

Adaptation to, or acceptance of, acquired spinal cord injury is accepted as an essentially longitudinal process. Changes in an individual's social, financial and domestic positions in turn affect issues concerning quality of life and self-image. The responses of 302 individuals with spinal cord injury in the United Kingdom and United States of America are presented to produce individual profiles of social adjustment. The differences between the UK and USA groups are presented, together with a combined analysis which addresses, in particular, the effects which being involved in litigation has on the process of social adjustment. Individual data concerning social adjustment, provided through a scale developed by the authors, and the utility of graphical presentation of the data is also presented. Such presentation has been found to have particular importance in clinical interview, situations by providing a framework for further exploration of individual adjustment difficulties, and in legal settings.

Estimating social adjustment following spinal trauma--I: Who is more realistic--patient or spouse? A statistical justification

Whilst assessment of functional independence has been accomplished, to a greater extent, following spinal trauma, assessing social adjustment remains an area requiring considerable further investigation. Providing premorbid estimation of adjustment is an area which presents a number of methodological difficulties both in the collection and interpretational of longitudinal data. Such analyses tend to allow overall estimates of adjustment to be made but which lack individual specificity. Analyses are presented of over 250 individuals, and their closest relative's assessment, of social adjustment to their spinal cord injury. Using a modification of an established scale for assessing social adjustment it has been possible to establish the statistical level of agreement and address the hypothesis of differential perception of the extent of adjustment problems by the injured person and their closest relative. The study allows for the conclusion that an injured person's perception of adjustment is at least as reliable as their closest relative, and that there is further evidence to support the essential accuracy of their estimations of premorbid and current levels of adjustment. Both issues are of clinical importance, particularly in relation to any medico-legal compensation aspects.

Metaiodobenzylguanidine as an index of atrioventricular nodal adrenergic activity

Despite its importance, little is known about the uptake, storage and release of catecholamines in the atrioventricular (AV) node and His bundle. Previous in vitro studies have been limited by metabolism of norepinephrine. Metaiodobenzylguanidine (MIBG) shares many transport properties with norepinephrine and is considered a functional marker of adrenergic activity.

METHODS

We used [125I]MIBG +/- 99mTc-sestamibi (99mTc-MIBI) and [123I]MIBG +/- 201TI] to evaluate regional differences in adrenergic activity between cardiac conductive and contractile elements in rats. Histological localization of the AV node and His bundle was performed using stains for acetylcholinesterase.

RESULTS

Densitometric evaluation of autoradiographs, obtained from 20-mu thick sections of hearts from rats injected with either [125I]MIBG +/- 99mTc-MIBI (n = 4) and [123I]MIBG +/- 201TI (n = 6), revealed that there was approximately 30% more MIBG uptake in the AV node and His bundle compared to atrial or ventricular muscle (p < 0.05). Color-coded functional maps, generated by computer to simultaneously display 123I or [125I]MIBG and perfusion markers, revealed that the heterogeneous distribution of MIBG was independent of myocardial blood flow.

CONCLUSION

When used as a selective functional marker of adrenergic activity in the cardiac conduction system, 123I- or [125I]MIBG autoradiography demonstrates increased adrenergic activity in the AV node and His bundle compared with the left ventricle. MIBG imaging provides a new research technique to probe in vivo modulation of AV nodal and His bundle sympathetic activity.