Sex differences in surgical site infections following coronary artery bypass grafting: a retrospective observational study

BACKGROUND

Surgical site infection (SSI) following cardiac surgery poses a significant challenge for healthcare providers. Despite advances in surgical techniques and infection control measures, SSI remains a leading cause of morbidity and mortality, in addition to being a significant economic burden on healthcare services. Current literature suggests there is a reproducible difference in the incidence of SSI following cardiac surgery between sexes. We aim to assess the sex-specific predictive risk factors for sternal SSI following coronary artery bypass grafting (CABG) in addition to identifying any differences in the causative organisms between groups.

METHODS

Adult patients undergoing isolated CABG between January 2012 and December 2022 in one UK hospital organization were included. In this 10-year, retrospective observational study, a total of 10,208 patients met the inclusion criteria. Pre-operative risk factors were identified using univariate analysis. To assess dependence between sex and organism or Gram stain, a Pearson Chi-squared test with Yates correction for continuity was performed.

RESULTS

In total there were 8457 males of which 181 developed a sternal SSI (2.14%) and 1751 females, 128 of whom had a sternal SSI (7.31%). Male patients were found to be significantly more likely to develop an SSI secondary to a Gram-positive organism, whereas female patients were more likely to have a Gram-negative causative organism (P<0.00001). Staphylococcus was statistically more likely to be the causative organism genus in male patients. Pseudomonas aeruginosa was found to be twice as common in the female cohort compared with the male group.

CONCLUSION

In our study, we found a statistically significant difference in the causative organisms and Gram stain for post-CABG sternal SSIs between males and females. Male patients predominately have Gram-positive associated SSIs, whereas female SSI pathogens are more likely to be Gram negative. The preoperative risk profiles of both cohorts are similar, including being an insulin-dependent diabetic and triple vessel coronary artery disease. Given these findings, it prompts the question, should we be tailoring our SSI treatment strategies according to sex and associated risk profiles?

Impact of COVID-19 pandemic on surgical care of patients with acute aortic conditions

Background

The outbreak of COVID-19 pandemic catastrophically interrupted medical care systems causing substantial decrease in the admission of patients and consecutively a sharp decline in the number of surgeries and interventions. In several European countries, the nationwide lockdown severely restricted movement which may have contributed to this phenomenon on top of anxiety of patients to contract COVID-19 when admitted to hospital.

Purpose

The aim of this analysis was to evaluate the impact of the COVID-19 pandemic onto acute and elective thoracic aortic surgeries and interventions and to compare the data with the same period in 2019 in a single aortic centre.

Methods

Information on admission and surgery/intervention was extracted from hospital electronic record system. Patients who were admitted for treatment of aortic conditions between January 1st to June 30th both in 2019 and 2020 were identified and selected for this analysis. The time from referral to admission and surgery/intervention was noted for service delay analysis. Aortopathies were classified as type A aortic dissection, type B aortic dissection, aortic aneurysm and others. In a daily central hub meeting, urgency was defined as emergent (operation required before the next working day), urgent (operation needed within 48 hours), and elective. Patients' condition and comorbidities were represented by ACEF II score.

Results

Total case volume of 81 in 2019 reference period was reduced to 70 in 2020 (−14%). Elective cases significantly declined from 59 (72.8%) in 2019 to 30 (42.8%) in 2020 (−49%). Urgent and emergent cases were performed more frequently in 2020 with 40 cases versus 22 in 2019 (+45%).

The ACEF II score showed no difference for patients in both periods (2.1±1.9 vs. 2.5±2.1, p=0.221), however, a trend to higher ACEF II score in 2020 consistent with a higher proportion of urgent and emergent cases.

The overall in-hospital delay (from admission to surgery) was not significant affected with 1 (IQR 1–2) versus 1 (IQR 0–2); p=0.991. However, with the official declaration of a pandemic and introduction of restrictions, no in-hospital delay was documented.

In-hospital mortality was observed lower in 2019 as compared in 2020 (6.1% vs 11.4%, P=0.251).

Conclusion

The first wave of COVID-19 pandemic disrupted the aortic service, however, acute care for urgent thoracic aortic conditions and subsequent procedures even increased compared to 2019 as a result of both centralised allocation system and decline of elective cases. Acute aortic syndromes were managed despite COVID-19 according to current guidelines.

Funding Acknowledgement

Type of funding sources: None.

1547 An Alternative Approach to High-Risk Resternotomy

Introduction

Resternotomies are associated with substantial perioperative morbidity and mortality. Strategies described in literature mostly involve peripheral cannulation pre-sternotomy. Disadvantages of this technique relate to prolonged systemic heparinisation and cardiopulmonary bypass (CPB) time and the sequelae of hypothermic circulatory arrest. We describe a two-stage approach that potentially reduces the complications associated with high-risk resternotomy.

Method

3 high-risk patients (from pre-operative CT images) were referred for redo complex aortic surgery. A right mini-thoracotomy incision was first made in the 4th or 5th intercostal space. The right lung was isolated and careful blunt dissection was carried out to mobilise the heart and great vessels attached to the sternum. Once these structures were free, thoracotomy incision was closed. A standard median sternotomy was then performed and central cannulation carried out after systemic heparinisation. Rest of the surgery was performed routinely. In one patient, aortic aneurysm was heavily adherent and attempts to mobilise it fully proved impossible. Resultantly, systemic heparinisation was administered and the patient was cannulated in the right superficial femoral artery and right atrium (via mini-thoracotomy). CPB was instituted and the patient cooled to 28 °C. Right superior pulmonary vein vent was introduced to prevent left ventricular distension from hypothermic ventricular fibrillation. Once the heart and aneurysm were decompressed on full CPB, complete mobilisation was performed safely. All 3 patients survived surgery without major complications.

Conclusions

Meticulous preoperative planning is key to management of high-risk resternotomy. We describe a novel technique which we believe minimises risk of morbidity and mortality in these complex cases.

Irrigation of radish (Raphanus sativus L.) with microcystin-enriched water holds low risk for plants and their associated rhizopheric and epiphytic microbiome

Microcystins (MCs) are toxins produced during cyanobacterial blooms. They reach soil and translocated to plants through irrigation of agricultural land with water from MC-impacted freshwater systems. To date we have good understanding of MC effects on plants, but not for their effects on plant-associated microbiota. We tested the hypothesis that MC-LR, either alone or with other stressors present in the water of the Karla reservoir (a low ecological quality and MC-impacted freshwater system), would affect radish plants and their rhizospheric and phyllospheric microbiome. In this context a pot experiment was employed where radish plants were irrigated with tap water without MC-LR (control) or with 2 or 12 μg L^-1 of pure MC-LR (MC2 and MC12), or water from the Karla reservoir amended (12 μg L^-1) or not with MC-LR. We measured MC levels in plants and rhizospheric soil and we determined effects on (i) plant growth and physiology (ii) the nitrifying microorganisms via q-PCR, (ii) the diversity of bacterial and fungal rhizospheric and epiphytic communities via amplicon sequencing. MC-LR and/or Karla water treatments resulted in the accumulation of MC in taproot at levels (480-700 ng g^-1) entailing possible health risks. MC did not affect plant growth or physiology and it did not impose a consistent inhibitory effect on soil nitrifiers. Karla water rather than MC-LR was the stronger determinant of the rhizospheric and epiphytic microbial communities, suggesting the presence of biotic or abiotic stressors, other than MC-LR, in the water of the Karla reservoir which affect microorganisms with a potential role (i.e. pathogens inhibition, methylotrophy) in the homeostasis of the plant-soil system. Overall, our findings suggest that MC-LR, when applied at environmentally relevant concentrations, is not expected to adversely affect the radish-microbiota system but might still pose risk for consumers' health.

P2272Determinants of left ventricular ATP availability measured in vivo and ex vivo in patients with severe aortic stenosis: correlation of creatine kinase activity with LVEF and ATP diffusion distance

Introduction

The transition to systolic failure in severe aortic stenosis (AS) increases mortality. There are currently no reliable markers of transition, and the guideline LVEF <50% threshold for intervention in asymptomatic severe AS does not capture all subjects at increased risk. In animal models, reduced ATP delivery capacity through creatine kinase (CK) is important, with modest increases in CK capacity conferring cardioprotection. ATP may also diffuse (independent of CK) from mitochondria to the contractile site. We have performed the first human study to test whether ATP diffusion distance relates to CK activity and whether CK activity is reduced in low LVEF severe AS.

Methods

19 patients with severe AS, LVEF ≥55% (AS-pEF, mean±SD LVEF 63±5%, mean gradient 48±14 mmHg) and 10 with severe AS, LVEF <55% (AS-rEF, LVEF 42±8%, mean gradient 32±11) underwent 31P-MRS for CK rate constant (kf) and phosphocreatine/ATP (PCr/ATP) ratio, and MRI for LV volumes. LV biopsies were taken during AVR and analysed for CK total activity, CK isoforms, total creatine, and citrate synthase (CS) activity. 9 biopsies also underwent serial block face scanning electron microscopy and mitochondria-sarcomere 3D distance distributions were plotted. Results were compared to 24 controls (LVEF 61±4%), of which 4 had LV biopsy (3 severe MS, 1 LA myxoma, MS-pEF). Surgical patients had flow-limiting atheroma excluded with invasive angiography and prior myocardial infarction excluded with late gadolinium enhancement MRI.

Results

When compared to controls, both CK total activity and CS activity were lower in AS-pEF (by 27% and 23% respectively, both p<0.05, Panels A-B). Although PCr/ATP reduced in AS-pEF (by 20%, p<0.001, panel C), kf (panel D) and CK flux estimated by kf × total creatine were not different. CK-MB expression reduced in AS-pEF (19 vs 27% of total CK, p=0.003), reflecting compensatory increases in CK-MM (p=0.26) and CK-BB (p=0.18) in the face of reduced CK activity.

AS-rEF was associated with further reduction in both CK and CS activities (by 32% and 22% respectively, both p<0.05, Panels A-B), but no differences in PCr/ATP, CK kf or relative CK isozyme expression were seen. There were no significant between-group differences in total creatine (Panel E). Overall this suggests that CK reserve and oxidative capacity potentially reduce in pressure overload, with further falls commensurate with systolic dysfunction.

When median mitochondria-sarcomere ATP diffusion distances were plotted against CK total activity a strong positive correlation was observed (r=0.86, p=0.003, Panel F). This suggests a compensatory reduction in diffusion distance develops when CK activity falls.

Conclusions

Transition to failure in severe AS is associated with lower oxidative capacity and maximal ATP delivery capacity through CK. Despite compensatory falls in ATP diffusion distance and altered CK isozyme expression, these changes may underlie susceptibility to EF decline in AS.

Acknowledgement/Funding

British Heart Foundation Clinical Research Training Fellowship (FS/15/80/31803) and Programme Grant (RG/18/12/34040).

P1611Non-invasive predictors of LV biopsy-obtained creatine kinase activity in patients with non-failing and failing myocardial hypertrophy

Introduction

Myocardial creatine kinase (CK) activity represents an important metabolic reserve: it correlates closely with contractile reserve and post-ischaemic function, keeps cytosolic [ADP] low, and optimises the free energy for ATP hydrolysis. It may also contribute to the transition to failure in the heart hypertrophied by chronic haemodynamic overload; modest up-regulation has been shown to be cardio-protective.

Total CK activity measurement requires chemical freeze-and-extract methods, which destroy tissue, precluding repeated measures. To date, non-invasive assessments of human myocardial CK flux (calculated as kf × [PCr], where kf is the pseudo-first-order forward rate constant measured by 31P-magnetic resonance spectroscopy (MRS) have not assessed creatine content or total CK activity. Thus we aimed to validate kf measurement against total CK activity and investigate predictors of CK activity.

Methods

39 subjects (median age 71, range 43–84) undergoing clinically indicated cardiac surgery had CK total activity measured from LV biopsy. 31 had severe AS (10 with impaired LVEF); 2 had severe primary MR; 5 had severe mitral stenosis (2 with impaired LVEF) and 1 had an LA mass. 35 of 39 contributed triplicate datasets: CK total activity, kf (31P-MRS TRiST sequence at 3T) and LV volumes (cine-MRI, 3T Siemens). 27 had severe AS (8 with impaired LVEF); other groups were the same. Exclusion criteria were prior myocardial infarction and flow-limiting coronary disease. Flash-frozen LV biopsies obtained within 15 min of cardiopulmonary bypass were analysed for CK total activity, total creatine, and citrate synthase (CS) activity (a marker of oxidative phosphorylation capacity).

Results

Multiple, novel correlations were observed between CK total activity (IU/mg protein) and CS activity (r=0.87, p=9e-13), total creatine (r=0.59, p=8e-5), kf (r=0.42, p=0.013), total creatine × kf (r=0.64, p=4e-5), LVESVi (r=−0.52, p=8e-4), LVEF (r=0.48, p=0.002) and LVMi (r=−0.42, p=0.009) (Panels A-E) (LVEDVi and non-indexed counterparts were also significant correlates.) The most predictive linear regression model incorporating elements of the CK rate equation included total creatine (nmol/mg protein), kf (/s), and kf × LVESVi (ml/m2) (adjusted R2=0.56, beta=0.426, 0.618, −1.968 and p=0.001, 5e-5, 0.003 respectively, Panel F).

Figure 1

Conclusions

These results are the first evidence of agreement between non-invasive estimates of human cardiac CK activity (kf) and freeze-extracted chemical methods. The key original finding is that it is feasible to attempt to predict CK capacity in vivo by using a combination of techniques (creatine by 1H MRS, CK kf by 31P-MRS and LVESVi by cine imaging). The key insight is that CK capacity is best estimated not simply from what the rate equation would predict (creatine and kf), but that other factors relating to failing contractility reduce CK activity independently from creatine content and enzyme kf.

Acknowledgement/Funding

British Heart Foundation Clinical Research Training Fellowship (FS/15/80/31803) and Programme Grant (RG/18/12/34040).

Estimating the birth prevalence and pregnancy outcomes of congenital malformations worldwide

Congenital anomaly registries have two main surveillance aims: firstly to define baseline epidemiology of important congenital anomalies to facilitate programme, policy and resource planning, and secondly to identify clusters of cases and any other epidemiological changes that could give early warning of environmental or infectious hazards. However, setting up a sustainable registry and surveillance system is resource-intensive requiring national infrastructure for recording all cases and diagnostic facilities to identify those malformations that that are not externally visible. Consequently, not all countries have yet established robust surveillance systems. For these countries, methods are needed to generate estimates of prevalence of these disorders which can act as a starting point for assessing disease burden and service implications. Here, we describe how registry data from high-income settings can be used for generating reference rates that can be used as provisional estimates for countries with little or no observational data on non-syndromic congenital malformations.

Renal allograft recipients fail to increase interferon-γ during invasive fungal diseases

Invasive fungal diseases are a major cause of death in renal allograft recipients. We previously reported that adjunctive recombinant human interferon-γ therapy has clinical utility for invasive fungal diseases after renal transplantation. We have now developed a rapid peripheral blood-based quantitative real-time PCR assay that enables accurate profiling of cytokine imbalances. Our preliminary studies in renal transplant patients with invasive fungal diseases suggest that they fail to mount an adequate interferon-γ response to the fungal infection. In addition, they have reduced IL-10 and increased TNF-α when compared to stable renal transplant patients. These preliminary cytokine profiling-based observations provide a possible explanation for the therapeutic benefit of adjunctive human interferon-γ therapy in renal allograft recipients with invasive fungal diseases.

Prenatal diagnosis for thalassaemia in Egypt: what changed parents' attitude?

OBJECTIVES

To present the current status of the prenatal diagnosis services and results from the largest thalassaemia center in Egypt treating 3000 patients. Traditionally, prenatal diagnosis has not been successful in reducing the births of affected children in Egypt, because the majority of women undergoing prenatal diagnosis continued to have affected pregnancies.

METHODS

Seventy-one pregnant mothers at risk for β-thalassaemia underwent prenatal diagnosis by chorionic villus sampling (n=57) or amniocentesis (n=14) between 11 to 14 weeks of gestation. Molecular characterization of fetal DNA by reverse dot blot hybridization and polymerase chain reaction-amplification refractory mutation system techniques was conducted in all cases.

RESULTS

Twenty-four women (33.8%) were found to have affected fetuses; 100% of these women opted to terminate the pregnancy. The change in attitude towards termination of pregnancy was related to in-depth counseling of the religious aspects towards prenatal diagnosis and termination of pregnancy. Forty-eight women (66.2%) with normal or carrier fetuses for β-thal requested human leukocyte antigen typing of the fetal material to determine if the fetus was a human leukocyte antigen match for their existing thalassaemic siblings.

CONCLUSION

This study demonstrates that prenatal diagnosis is feasible and acceptable in Egypt, a Muslim country, provided an in-depth discussion, which also addresses the religious considerations of prevention, is held with the couples.

Decreased motor cortex γ-aminobutyric acid in amyotrophic lateral sclerosis

OBJECTIVES

To determine if there are in vivo differences in γ-aminobutyric acid (GABA) in the motor cortex and subcortical white matter of patients with amyotrophic lateral sclerosis (ALS) compared with healthy controls using proton magnetic resonance spectroscopy (1H-MRS).

METHODS

In this cross-sectional study, 10 patients with ALS and 9 age- and sex-matched healthy controls (HCs) underwent 3T edited 1H-MRS to quantify GABA centered on the motor cortex and the subcortical white matter.

RESULTS

Compared with healthy controls, patients with ALS had significantly lower levels of GABA in the left motor cortex (1.42 ± 0.27 arbitrary institutional units vs. 1.70 ± 0.24 arbitrary institutional units, p = 0.038). There was no significant difference in GABA levels between groups in the subcortical white matter (p > 0.05).

CONCLUSION

Decreased levels of GABA are present in the motor cortex of patients with ALS compared to HCs. Findings are consistent with prior reports of alterations in GABA receptors in the motor cortex as well as increased cortical excitability in the context of ALS. Larger, longitudinal studies are needed to confirm these findings and to further our understanding of the role of GABA in the pathogenesis of ALS.

Obtaining the Correspondence Between Bayesian and Neural Networks

We present in this paper a novel method for eliciting the conditional probability matrices needed for a Bayesian network with the help of a neural network. We demonstrate how we can obtain a correspondence between the two networks by deriving a closed-form solution so that the outputs of the two networks are similar in the least square error sense, not only when determining the discriminant function, but for the full range of their outputs. For this purpose we take into consideration the probability density functions of the independent variables of the problem when we compute the least square error approximation. Our methodoloy is demonstrated with the help of some real data concerning the problem of risk of desertification assessment for some burned forests in Attica, Greece where the parameters of the Bayesian network constructed for this task are successfully estimated given a neural network trained with a set of data.

Cerebral blood flow alterations in pain-processing regions of patients with fibromyalgia using perfusion MR imaging

BACKGROUND AND PURPOSE

Widespread pain sensitivity in patients with FM suggests a CNS processing problem. The purpose of this study was to assess alterations in perfusion as measured by DSC in a number of brain regions implicated in pain processing between patients with FM and healthy controls.

MATERIALS AND METHODS

Twenty-one patients with FM and 27 healthy controls underwent conventional MR imaging and DSC. For DSC, 12 regions of interest were placed in brain regions previously implicated in pain processing. rCBF values were calculated for each region of interest. Subjects answered mood/pain coping questionnaires and underwent clinical/experimental pain assessment.

RESULTS

There were significant correlations between the thalamic rCBF values and the pain-control beliefs of FM subjects. The strength of the relationship between clinical pain measures and thalamic rCBF values increased after adjusting for pain-control beliefs. There was a significantly different distribution pattern of rCBF values across various brain regions between the FM group and the healthy controls. There was a lower degree of correlation in the FM group between the thalamic rCBF values and the other brain regions relative to the healthy controls.

CONCLUSIONS

Significant correlations were found between thalamic rCBF values and pain belief values. These data suggest that there are baseline alterations of brain perfusion in patients with FM. rCBF values of the thalami exhibited lower correlations with respect to other brain regions thought to be involved in pain processing compared with those in healthy controls.

Fourier-transform Raman spectroscopic study of a Neolithic waterlogged wood assemblage

The use of Fourier-transform Raman spectroscopy for characterising lignocellulosics has increased significantly over the last twenty years. Here, an FT-Raman spectroscopic study of changes in the chemistry of waterlogged archaeological wood of Pinus sp. and Quercus sp. from a prehistoric assemblage recovered from northern Greece is presented. FT-Raman spectral features of biodeteriorated wood were associated with the depletion of lignin and/or carbohydrate polymers at various stages of deterioration. Spectra from the archaeological wood are presented alongside spectra of sound wood of the same taxa. A comparison of the relative changes in intensities of spectral bands associated with lignin and carbohydrates resulting from decay clearly indicated extensive deterioration of both the softwood and hardwood samples and the carbohydrates appear to be more deteriorated than the lignin. The biodeterioration of the archaeological timbers followed a pattern of initial preferential loss of carbohydrates causing significant loss of cellulose and hemicellulose, followed by the degradation of lignin.

Minimal hepatic encephalopathy in children: evaluation with proton MR spectroscopy

BACKGROUND AND PURPOSE

Minimal hepatic encephalopathy (MHE) in children is difficult to evaluate because of lack of standardized neuropsychological tests for all age ranges. The purpose of this retrospective study of children with clinically suspected MHE was to investigate relationships between brain MR spectroscopy metabolites and biochemical markers of encephalopathy as well as measures of liver disease severity.

MATERIALS AND METHODS

A total of 12 children (age range, 9-19 years; 8 female) with clinically suspected MHE were studied by short TE brain MR spectroscopy on a 1.5T magnet. We estimated gray matter (GM) and white matter (WM) metabolite concentrations using "LCModel" software. Regional metabolite concentrations were examined for correlation with various parameters, including plasma ammonia, the ratio of branched-chain to aromatic amino acids (BCAA/AAA), model for end stage liver disease/pediatric end stage liver disease (MELD/PELD) and Child-Pugh scores, bilirubin, albumin, and platelet counts.

RESULTS

Myo-inositol (mIns) levels correlated with BCAA/AAA ratios (r = 0.86; P = .002 for GM and r = 0.77; P = .01 for WM). WM choline (Cho) levels and GM mIns levels showed significant negative correlation with ammonia levels (r = -0.58; P = .04 and r = -0.65; P = .02, respectively). A positive significant correlation trend was present for GM glutamine/glutamate (Glx) and ammonia levels (r = 0.66; P = .05). There was no correlation of brain MR spectroscopy parameters and severity of liver disease.

CONCLUSIONS

Brain MR spectroscopy metabolites in children with suspected MHE show significant correlations with plasma ammonia levels and BCAA/AAA. As in adults, brain MR spectroscopy in children may be helpful in establishing a diagnosis of MHE.

Minimal hepatic encephalopathy in children: evaluation with proton MR spectroscopy

BACKGROUND AND PURPOSE

Minimal hepatic encephalopathy (MHE) in children is difficult to evaluate because of lack of standardized neuropsychological tests for all age ranges. The purpose of this retrospective study of children with clinically suspected MHE was to investigate relationships between brain MR spectroscopy metabolites and biochemical markers of encephalopathy as well as measures of liver disease severity.

MATERIALS AND METHODS

A total of 12 children (age range, 9-19 years; 8 female) with clinically suspected MHE were studied by short TE brain MR spectroscopy on a 1.5T magnet. We estimated gray matter (GM) and white matter (WM) metabolite concentrations using "LCModel" software. Regional metabolite concentrations were examined for correlation with various parameters, including plasma ammonia, the ratio of branched-chain to aromatic amino acids (BCAA/AAA), model for end stage liver disease/pediatric end stage liver disease (MELD/PELD) and Child-Pugh scores, bilirubin, albumin, and platelet counts.

RESULTS

Myo-inositol (mIns) levels correlated with BCAA/AAA ratios (r = 0.86; P = .002 for GM and r = 0.77; P = .01 for WM). WM choline (Cho) levels and GM mIns levels showed significant negative correlation with ammonia levels (r = -0.58; P = .04 and r = -0.65; P = .02, respectively). A positive significant correlation trend was present for GM glutamine/glutamate (Glx) and ammonia levels (r = 0.66; P = .05). There was no correlation of brain MR spectroscopy parameters and severity of liver disease.

CONCLUSIONS

Brain MR spectroscopy metabolites in children with suspected MHE show significant correlations with plasma ammonia levels and BCAA/AAA. As in adults, brain MR spectroscopy in children may be helpful in establishing a diagnosis of MHE.

Proton MR spectroscopy in the evaluation of cerebral metabolism in patients with fibromyalgia: comparison with healthy controls and correlation with symptom severity

BACKGROUND AND PURPOSE

Widespread pain sensitivity in patients with fibromyalgia (FM) suggests a central nervous system (CNS)-processing problem. Therefore, it is conceivable that metabolic alterations exist in pain-processing brain regions of people with FM compared with healthy controls (HC) and that such metabolic data could correlate with clinical symptoms. The purpose of this study was to test these hypotheses using proton MR spectroscopy ((1)H-MR spectroscopy).

MATERIALS AND METHODS

There were 21 patients with FM and 27 HC who underwent conventional structural MR imaging and additional 2D-chemical shift imaging (CSI) MR-spectroscopy sequences. For the 2D-CSI spectroscopy, larger volumes of interest (VOIs) were centered at the level of the basal ganglia and the supraventricular white matter. Within these larger areas, 16 smaller voxels were placed in a number of regions previously implicated in pain processing. N-acetylaspartate (NAA)/creatine(Cr), choline (Cho)/Cr and NAA/Cho ratios were calculated for each voxel. Subjects underwent clinical and experimental pain assessment.

RESULTS

Mean metabolite ratios and ratio variability for each region were analyzed by using repeated-measures analysis of variance (ANOVA). Correlations between clinical symptoms and metabolite ratios were assessed. Cho/Cr variability in the right dorsolateral prefrontal cortex (DLPFC) was significantly different in the 2 groups; a significant correlation between Cho/Cr in this location and clinical pain was present in the FM group. Evoked pain threshold correlated significantly with NAA/Cho ratios in the left insula and left basal ganglia.

CONCLUSION

Our data suggest that there are baseline differences in the variability of brain metabolite relative concentrations between patients with FM and HC, especially in the right DLPFC. Furthermore, there are significant correlations between metabolite ratios and clinical and experimental pain parameters in patients with FM.

Heart transplantation for homozygous familial transthyretin (TTR) V122I cardiac amyloidosis

Heart failure is the usual cause of death in patients with amyloid cardiomyopathy. The commonest form of hereditary cardiac amyloidosis is associated with the Val122Ile variant of transthyretin (TTR), which is carried by 3-4% of the African American population. Here, we report the outcome of the first cardiac transplantation in a patient with TTR V122I. A 59-year-old Caribbean man presented with biventricular failure. Other than previous bilateral carpel tunnel syndrome, he had been well and had no evidence of extracardiac amyloidosis. An endomyocardial biopsy demonstrated amyloid of TTR type. Sequencing of TTR gene indicated homozygosity for V122I. He underwent cardiac transplantation and 3 years later, remains well with no evidence of allograft or systemic amyloid deposition.

Intracranial infections: clinical and imaging characteristics

The radiologist plays a crucial role in identifying and narrowing the differential diagnosis of intracranial infections. A thorough understanding of the intracranial compartment anatomy and characteristic imaging findings of specific pathogens, as well incorporation of the clinical information, is essential to establish correct diagnosis. Specific types of infections have certain propensities for different anatomical regions within the brain. In addition, the imaging findings must be placed in the context of the clinical setting, particularly in immunocompromised and human immunodeficiency virus (HIV)-positive patients. This paper describes and depicts infections within the different compartments of the brain. Pathology-proven infectious cases are presented in both immunocompetent and immunocompromised patients, with a discussion of the characteristic findings of each pathogen. Magnetic resonance spectroscopy (MRS) characteristics for several infections are also discussed.

Diagnostic features of Alzheimer's disease extracted from PET sinograms

Texture analysis of positron emission tomography (PET) images of the brain is a very difficult task, due to the poor signal to noise ratio. As a consequence, very few techniques can be implemented successfully. We use a new global analysis technique known as the Trace transform triple features. This technique can be applied directly to the raw sinograms to distinguish patients with Alzheimer's disease (AD) from normal volunteers. FDG-PET images of 18 AD and 10 normal controls obtained from the same CTI ECAT-953 scanner were used in this study. The Trace transform triple feature technique was used to extract features that were invariant to scaling, translation and rotation, referred to as invariant features, as well as features that were sensitive to rotation but invariant to scaling and translation, referred to as sensitive features in this study. The features were used to classify the groups using discriminant function analysis. Cross-validation tests using stepwise discriminant function analysis showed that combining both sensitive and invariant features produced the best results, when compared with the clinical diagnosis. Selecting the five best features produces an overall accuracy of 93% with sensitivity of 94% and specificity of 90%. This is comparable with the classification accuracy achieved by Kippenhan et al (1992), using regional metabolic activity.

Influence of clenbuterol treatment during six weeks of chronic right ventricular pressure overload as studied with pressure-volume analysis

OBJECTIVES

Chronic pressure overload cardiac hypertrophy produces ventricular dysfunction. There is evidence that clenbuterol, a beta(2)-adrenoceptor agonist, produces cardiac hypertrophy with preserved function in rodents. We sought to determine the cardiac hypertrophic effects of clenbuterol on the thin-walled ventricles of large animals undergoing chronic pressure overload by means of pulmonary artery banding.

METHODS

Right ventricular pressure-volume loops were obtained in open-chest sheep before and after 6-1/2 weeks of pulmonary artery banding by using micromanometer conductance catheters. Animals were randomly assigned to treatment with either saline solution (n = 7) or clenbuterol (n = 8). Treatment was started immediately after pulmonary artery banding.

RESULTS

Acute pulmonary artery banding increased the right ventricular systolic pressure equally in both groups (saline group, 23.9 +/- 3.3 to 48.1 +/- 9.7 mm Hg; clenbuterol group, 24.3 +/- 2.8 to 48.6 +/- 10.7 mm Hg [mean +/- standard deviation]). Six weeks of treatment produced no significant differences in the body weight, heart weight, heart/body weight ratio, right ventricular wall thickness, heart rate, and stroke volume between the groups. However, the slope of the end-systolic pressure-volume relation and the slope of the first derivative of the right ventricular developed pressure/end-diastolic volume relation were significantly increased when compared with baseline values in clenbuterol-treated animals but not in saline-treated animals.

CONCLUSION

Clenbuterol treatment during pulmonary artery banding improves systolic function of the chronically pressure-overloaded right ventricle. This has important implications for the use of pharmacologic agents in modulating cardiac adaptation.

A national register for surveillance of inherited disorders: beta thalassaemia in the United Kingdom

OBJECTIVE

To demonstrate the value of a national register for surveillance of services for an inherited disorder.

METHODS

Data from the United Kingdom Thalassaemia Register and the United Kingdom Register of Prenatal Diagnosis for Haemoglobin Disorders were combined in a database; these registers include all fetuses known to have been diagnosed with beta thalassaemia major, beta thalassaemia intermedia, or haemoglobin E/beta thalassaemia in the United Kingdom. Data were extracted to show outcomes (selective abortion or live birth) of all fetuses and the status of those born with a disorder (alive, dead, successful bone marrow transplant, or lost to follow-up) by parents' region of residence and ethnicity.

FINDINGS

At the end of 1999 the register included 1074 patients, 807 of whom were alive and residing in the United Kingdom. A successful bone marrow transplant has been performed for 117 out of 581 (20%) patients born since 1975. Residents of Pakistani origin are now the main group at risk in the United Kingdom, replacing residents of Cypriot origin. This has led to a marked shift in the need for services from the south-east of England to the Midlands and the north of England. Despite the acceptability of prenatal diagnosis, the proportion of affected births remains 50% higher than would be expected, reflecting a widespread failure to deliver timely screening and counselling to carriers. Even though effective treatment is available the annual number of deaths is rising, indicating that better tolerated treatments are needed.

CONCLUSION

A national diagnosis register is a powerful instrument for monitoring the treatment and prevention of inherited disorders and for highlighting correctable shortcomings. In view of the increasing possibilities for genetic screening there is a strong case for central funding for such databases within modern health services.