Short-term High-Intensity Interval Training Improves Fitness Before Surgery: A Randomised Clinical Trial

PURPOSE

Improving cardiopulmonary reserve, or peak oxygen consumption( V ˙ O_2peak ), may reduce postoperative complications, however this may be difficult to achieve between diagnosis and surgery. Our primary aim was to assess the efficacy of an approximate 14-session, preoperative High Intensity Interval Training(HIIT) program to increase V ˙ O_2peak by a clinically-relevant 2 mL·kg^-1 ·min^-1 . Our secondary aim was to document clinical outcomes.

METHODOLOGY

In this prospective study, participants aged 45-85 undergoing major abdominal surgery were randomised to standard care or 14 sessions of HIIT over 4 weeks. HIIT sessions involved approximately thirty minutes of stationary cycling. Interval training alternated one minute of high (with the goal of reaching 90% max heart rate at least once during the session) and low/moderate intensity cycling. Cardiopulmonary exercise testing(CPET) measured the change in V ˙ O_2peak from baseline to surgery. Clinical outcomes included postoperative complications, length of stay(LOS) and Short Form-36 quality of life questionnaire(SF-36).

RESULTS

Of 63 participants, 46 completed both CPETs and 50 completed clinical follow-up. There was a significant improvement in the HIIT group's mean ± SD V ˙ O_2peak (HIIT 2.87 ± 1.94 mL·kg¹ ·min^-1 vs standard care 0.15 ± 1.93, with an overall difference of 2.73 mL·kg¹ ·min^-1 95%CI [1.53, 3.93] p<0.001). There were no statistically significant differences between groups for clinical outcomes, although the observed differences consistently favoured the exercise group. This was most notable for total number of complications (0.64 v 1.16 per patient, p=0.07), SF-36 physical component score (p=0.06), and LOS (mean 5.5 v 7.4 days, p=0.07).

CONCLUSIONS

There was a significant improvement in V ˙ O_2peak with a four-week preoperative HIIT program. Further appropriately-powered work is required to explore the impact of preoperative HIIT on postoperative clinical outcomes.

Inhibition of calcium/calmodulin-dependent kinase II restores contraction and relaxation in isolated cardiac muscle from type 2 diabetic rats

BACKGROUND

Calcium/calmodulin-dependent kinase II-delta (CaMKIIδ) activity is enhanced during hyperglycemia and has been shown to alter intracellular calcium handling in cardiomyocytes, ultimately leading to reduced cardiac performance. However, the effects of CaMKIIδ on cardiac contractility during type 2 diabetes are undefined.

METHODS

We examined the expression and activation of CaMKIIδ in right atrial appendages from non-diabetic and type 2 diabetic patients (n = 7 patients per group) with preserved ejection fraction, and also in right ventricular tissue from Zucker Diabetic Fatty rats (ZDF) (n = 5-10 animals per group) during early diabetic cardiac dysfunction, using immunoblot. We also measured whole heart function of ZDF and control rats using echocardiography. Then we measured contraction and relaxation parameters of isolated trabeculae from ZDF to control rats in the presence and absence of CaMKII inhibitors.

RESULTS

CaMKIIδ phosphorylation (at Thr287) was increased in both the diabetic human and animal tissue, indicating increased CaMKIIδ activation in the type 2 diabetic heart. Basal cardiac contractility and relaxation were impaired in the cardiac muscles from the diabetic rats, and CaMKII inhibition with KN93 partially restored contractility and relaxation. Autocamtide-2-related-inhibitor peptide (AIP), another CaMKII inhibitor that acts via a different mechanism than KN93, fully restored cardiac contractility and relaxation.

CONCLUSIONS

Our results indicate that CaMKIIδ plays a key role in modulating performance of the diabetic heart, and moreover, suggest a potential therapeutic role for CaMKII inhibitors in improving myocardial function during type 2 diabetes.

Resting heart rate variability and exercise capacity in Type 1 diabetes

People with type 1 diabetes (T1D) have lower exercise capacity (V̇O_2max) than their age‐matched nondiabetic counterparts (CON), which might be related to cardiac autonomic dysfunction. We examined whether Heart Rate Variability (HRV; indicator of cardiac autonomic modulation) was associated with exercise capacity in those with and without T1D. Twenty‐three participants with uncomplicated T1D and 17 matched CON were recruited. Heart rate (HR; ECG), blood pressure (BP; finger photo‐plethysmography), and respiratory rate (respiratory belt) were measured during baseline, paced‐breathing and clinical autonomic reflex tests (CARTs); deep breathing, lying‐to‐stand, and Valsalva maneuver. Baseline and paced‐breathing ECG were analyzed for HRV (frequency‐domain). Exercise capacity was determined during an incremental cycle ergometer test while V̇O₂, 12‐lead ECG, and BP were measured. In uncomplicated T1D, resting HR was elevated and resting HRV metrics were reduced, indicative of altered cardiac parasympathetic modulation; this was generally undetected by the CARTs. However, BP and plasma catecholamines were not different between groups. In T1D, V̇O_2max tended to be lower (P = 0.07) and HR reserve was lower (P < 0.01). Resting Total Power (TP) had stronger positive associations with V̇O_2max (R² ≥ 0.3) than all other traditional indicators such as age, resting HR, and self‐reported exercise (R² = 0.042–0.3) in both T1D and CON. Alterations in cardiac autonomic modulation are an early manifestation of uncomplicated T1D. Total Power was associated with reduced exercise capacity regardless of group, and these associations were generally stronger than traditional indicators.

Impaired ventricular filling limits cardiac reserve during submaximal exercise in people with type 2 diabetes

Background

Attenuated increases in ventricular stroke volume during exercise are common in type 2 diabetes and contribute to reduced aerobic capacity. The purpose of this study was to determine whether impaired ventricular filling or reduced systolic ejection were responsible for the attenuated stroke volume reserve in people with uncomplicated type 2 diabetes.

Methods

Peak aerobic capacity and total blood volume were measured in 17 people with diabetes and 16 non-diabetic controls with no evidence of cardiovascular disease. Left ventricular volumes and other systolic and diastolic functional parameters were measured with echocardiography at rest and during semi-recumbent cycle ergometry at 40 and 60% of maximal aerobic power and compared between groups.

Results

People with diabetes had reduced peak aerobic capacity and heart rate reserve, and worked at lower workloads than non-diabetic controls. Cardiac output, stroke volume and ejection fraction were not different at rest, but increased less in people with diabetes during exercise. Left ventricular end systolic volume was not different between groups in any condition but end diastolic volume, although not different at rest, was smaller in people with diabetes during exercise. Total blood volume was not different between the groups, and was only moderately associated with left ventricular volumes.

Conclusions

People with type 2 diabetes exhibit an attenuated increase in stroke volume during exercise attributed to an inability to maintain/increase left ventricular filling volumes at higher heart rates. This study is the first to determine the role of filling in the blunted cardiac reserve in adults with type 2 diabetes.

Electronic supplementary material

The online version of this article (10.1186/s12933-017-0644-1) contains supplementary material, which is available to authorized users.

Intratumoural evolutionary landscape of high-risk prostate cancer: the PROGENY study of genomic and immune parameters

BACKGROUND

Intratumoural heterogeneity (ITH) is well recognised in prostate cancer (PC), but its role in high-risk disease is uncertain. A prospective, single-arm, translational study using targeted multiregion prostate biopsies was carried out to study genomic and T-cell ITH in clinically high-risk PC aiming to identify drivers and potential therapeutic strategies.

PATIENTS AND METHODS

Forty-nine men with elevated prostate-specific antigen and multiparametric-magnetic resonance imaging detected PC underwent image-guided multiregion transperineal biopsy. Seventy-nine tumour regions from 25 patients with PC underwent sequencing, analysis of mutations, copy number and neoepitopes combined with tumour infiltrating T-cell subset quantification.

RESULTS

We demonstrated extensive somatic nucleotide variation and somatic copy number alteration heterogeneity in high-risk PC. Overall, the mutational burden was low (0.93/Megabase), but two patients had hypermutation, with loss of mismatch repair (MMR) proteins, MSH2 and MSH6. Somatic copy number alteration burden was higher in patients with metastatic hormone-naive PC (mHNPC) than in those with high-risk localised PC (hrlPC), independent of Gleason grade. Mutations were rarely ubiquitous and mutational frequencies were similar for mHNPC and hrlPC patients. Enrichment of focal 3q26.2 and 3q21.3, regions containing putative metastasis drivers, was seen in mHNPC patients. We found evidence of parallel evolution with three separate clones containing activating mutations of β-catenin in a single patient. We demonstrated extensive intratumoural and intertumoural T-cell heterogeneity and high inflammatory infiltrate in the MMR-deficient (MMRD) patients and the patient with parallel evolution of β-catenin. Analysis of all patients with activating Wnt/β-catenin mutations demonstrated a low CD8+/FOXP3+ ratio, a potential surrogate marker of immune evasion.

CONCLUSIONS

The PROGENY (PROstate cancer GENomic heterogeneitY) study provides a diagnostic platform suitable for studying tumour ITH. Genetic aberrations in clinically high-risk PC are associated with altered patterns of immune infiltrate in tumours. Activating mutations of Wnt/β-catenin signalling pathway or MMRD could be considered as potential biomarkers for immunomodulation therapies.

CLINICAL TRIALS.GOV IDENTIFIER

NCT02022371.

Is routine molecular screening for common α-thalassaemia deletions necessary as part of an antenatal screening programme?

Antenatal sickle and thalassaemia screening programmes are now established in most high prevalence areas in England. Although screening reliably detects β-thalassaemia trait, in many cases, results state that α-thalassaemia trait cannot be excluded. The detection of couples at risk of a child with hydrops fetalis is one of the aims of the national programme. We, therefore, performed polymerase chain reaction (PCR) for the common α-thalassaemia gene deletions to assess the usefulness of this technique in routine screening practice.

Between August 2001 and August 2002, of the 5092 women booked at the antenatal clinic, 425 were found to have a mean corpuscular haemoglobin (MCH) <27 pg in the absence of β-thalassaemia trait; 189 (44.5%) had an MCH <25 pg. All 425 patients underwent PCR analysis for the common deletions: –SEA (South-East Asian), –MED (Mediterranean), − α20.5, –FIL (Filipino), − α 3.7 and − α 4.2 genotypes.

In total, 130 (31%) women were positive for α-thalassaemia deletion; 86 (24.7%) were heterozygous for − α 3.7, 19 (4.4%) were homozygous for − α 3.7, 12 (2.8%) were heterozygous for − α 4.2, 1 (0.2%) was homozygous for − α 4.2, 11 (2.6%) were heterozygous for –SEA and one (0.2%) was heterozygous for the –MED genotype. Although the detection rate for α+-thalassaemia was high, a strategy of selective screening using MCH <25 pg and ethnic group (SEA, Middle East or Eastern MED) would have identified all individuals heterozygous for α0-thalassaemia.

Routine molecular screening for all forms of α-thalassaemia trait is unjustified in antenatal screening.

Detection of ubiquitous and heterogeneous mutations in cell-free DNA from patients with early-stage non-small-cell lung cancer

BACKGROUND

The aim of this pilot study was to assess whether both ubiquitous and heterogeneous somatic mutations could be detected in cell-free DNA (cfDNA) from patients with early-stage non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Three stage I and one stage II primary NSCLC tumors were subjected to multiregion whole-exome sequencing (WES) and validated with AmpliSeq. A subset of ubiquitous and heterogeneous single-nucleotide variants (SNVs) were chosen. Multiplexed PCR using custom-designed primers, coupled with next-generation sequencing (mPCR-NGS), was used to detect these SNVs in both tumor DNA and cfDNA isolated from plasma obtained before surgical resection of the tumors. The limit of detection for each assay was determined using cfDNA from 48 presumed-normal healthy volunteers.

RESULTS

Tumor DNA and plasma-derived cfDNA was successfully amplified and sequenced for 37/50 (74%) SNVs using the mPCR-NGS method. Twenty-five (68%) were ubiquitous and 12 (32%) were heterogeneous SNVs. Variant detection by mPCR-NGS and WES-AmpliSeq in tumor tissue was well correlated (R(2) = 0.8722, P < 0.0001). Sixteen (43%) out of 37 SNVs were detected in cfDNA. Twelve of these were ubiquitous SNVs with a variant allele frequency (VAF) range of 0.15-23.25%, and four of these were heterogeneous SNVs with a VAF range of 0.28-1.71%. There was a statistically significant linear relationship between the VAFs for tumor and cfDNA (R(2) = 0.5144; P = 0.0018). For all four patients, at least two variants were detected in plasma. The estimated number of copies of variant DNA present in each sample ranged from 5 to 524. The average number of variant copies required for detection (VCRD) was 3.16 (range: 0.2-7.6 copies).

CONCLUSIONS

The mPCR-NGS method revealed intratumor heterogeneity in early-stage NSCLC tumors, and was able to detect both ubiquitous and heterogeneous SNVs in cfDNA. Further validation of mPCR-NGS in cfDNA is required to define its potential use in clinical practice.

Retrospective Derivation and Validation of an Automated Electronic Search Algorithm to Identify Post Operative Cardiovascular and Thromboembolic Complications

BACKGROUND

With increasing numbers of hospitals adopting electronic medical records, electronic search algorithms for identifying postoperative complications can be invaluable tools to expedite data abstraction and clinical research to improve patient outcomes.

OBJECTIVES

To derive and validate an electronic search algorithm to identify postoperative thromboembolic and cardiovascular complications such as deep venous thrombosis, pulmonary embolism, or myocardial infarction within 30 days of total hip or knee arthroplasty.

METHODS

A total of 34 517 patients undergoing total hip or knee arthroplasty between January 1, 1996 and December 31, 2013 were identified. Using a derivation cohort of 418 patients, several iterations of a free-text electronic search were developed and refined for each complication. Subsequently, the automated search algorithm was validated on an independent cohort of 2 857 patients, and the sensitivity and specificities were compared to the results of manual chart review.

RESULTS

In the final derivation subset, the automated search algorithm achieved a sensitivity of 91% and specificity of 85% for deep vein thrombosis, a sensitivity of 96% and specificity of 100% for pulmonary embolism, and a sensitivity of 100% and specificity of 95% for myocardial infarction. When applied to the validation cohort, the search algorithm achieved a sensitivity of 97% and specificity of 99% for deep vein thrombosis, a sensitivity of 97% and specificity of 100% for pulmonary embolism, and a sensitivity of 100% and specificity of 99% for myocardial infarction.

CONCLUSIONS

The derivation and validation of an electronic search strategy can accelerate the data abstraction process for research, quality improvement, and enhancement of patient care, while maintaining superb reliability compared to manual review.

Contemporary gene flow and the spatio-temporal genetic structure of subdivided newt populations (Triturus cristatus, T. marmoratus)

Gene flow and drift shape the distribution of neutral genetic diversity in metapopulations, but their local rates are difficult to quantify. To identify gene flow between demes as distinct from individual migration, we present a modified Bayesian method to genetically test for descendants between an immigrant and a resident in a nonmigratory life stage. Applied to a metapopulation of pond-breeding European newts (Triturus cristatus, T. marmoratus) in western France, the evidence for gene flow was usually asymmetric and, for demes of known census size (N), translated into maximally seven reproducing immigrants. Temporal sampling also enabled the joint estimation of the effective demic population size (Ne) and the immigration rate m (including nonreproductive individuals). Ne ranged between 4.1 and 19.3 individuals, Ne/N ranged between 0.05 and 0.65 and always decreased with N; m was estimated as 0.19-0.63, and was possibly biased upwards. We discuss how genotypic data can reveal fine-scale demographic processes with important microevolutionary implications.

Gains on 9p are common genomic aberrations in idiopathic myelofibrosis: a comparative genomic hybridization study

Ideopathic myelofibrosis (IMF) is a chronic myeloproliferative disorder resulting in bone marrow fibrosis as a consequence of growth factor release from clonal haematopoiesis. Conventional cytogenetic analysis identifies abnormalities in approximately a third of cases at diagnosis, although rarely uncovers unique, primary genetic events. We have used comparative genomic hybridization (CGH) to study 25 IMF cases and have compared the results with conventional cytogenetics. Metaphase cells were available for analysis in 13 cases, of which seven showed an abnormal karyotype. CGH chromosomal profiles showed imbalances in 21 of 25 cases. The most frequent aberrations were gains of 9p (12 cases), 2q (seven cases), 3p (seven cases), chromosome 4 (seven cases), 12q (seven cases), 13q (eight cases). The main losses were at 17q and occurred in six cases. The results for CGH and cytogenetics were matched for one case only. Investigation of IMF by CGH suggests that genomic aberrations are much more common than has been previously indicated by conventional cytogenetic analysis and occur in the majority of cases. Gains of 9p were the most frequent finding, occurring in 50% of patients and suggests that genes on 9p may play a crucial role in the pathogenesis of IMF.

Biomechanical properties of quadruple tendon and patellar tendon femoral fixation techniques

Two femoral fixation techniques for quadruple hamstring tendon grafts were compared under cyclic loading with the patellar tendon: the rectangular inserted pin (TransFix) and biodegradable interference screw fixation of the quadruple tendon and titanium interference screw fixation of the middle third of the patellar tendon. Porcine specimens were mounted onto a tension load machine, and the tendon-fixation-femur-complex was tested for stiffness, displacement during 800 cycles of loading between 50 and 250 N and ultimate tension load. TransFix fixation showed the greatest stiffness at 183.6 N/mm ( P<0.05). The least displacement under cyclic loading was observed for the titanium interference screw followed by the TransFix and biodegradable interference screw ( P<0.01). The ultimate tension load was greatest for the TransFix fixation at 1303+/-282 N, followed by patellar tendon fixation with 763+/-103 N and the biodegradable interference screw fixation with 480+/-133 N ( P<0.001). To reduce initial elongation of the graft and displacement at the fixation site, preconditioning of both the tendon and tendon-fixation complex is especially important when using quadruple tendons. TransFix fixation provides better stability and greater stiffness and pull-out strength than the other techniques. This finding is of clinical relevance to surgeons of the anterior cruciate ligament.

Smoke gets in your eyes: smoking and visual impairment in New Zealand

AIM

To estimate the burden of visual impairment attributable to smoking in New Zealand.

METHODS

Review of Medline-indexed literature on the relationship between smoking and eye disease and use of relevant New Zealand morbidity and smoking prevalence data.

RESULTS

The international literature indicates there is strong evidence that smoking is a major cause of eye disease and blindness--particularly for cataracts and age-related macular degeneration (AMD). Using the most relevant international risk estimates, we estimated that 1335 people who are registered blind in New Zealand have AMD attributable to current and past smoking (26.8% of all AMD cases in the 55 years plus age-group). It was also estimated that 31 of the registered cases of visual impairment due to cataract and 396 hospitalisations for cataract surgery per year, are attributable to smoking. While subject to various methodological limitations, these estimates are probably under-estimates of the true burden of eye disease attributable to smoking.

CONCLUSIONS

Smoking is a major cause of untreatable visual impairment and also a significant reason for cataract surgery in New Zealand. There is a need for more intensive tobacco control activities in New Zealand.

Control elements of Dictyostelium discoideum prespore specific gene 3B

Expression of the prespore-specific gene 3B in Dictyostelium discoideum Ax-2 cells is first detectable late in development with 3B mRNA levels peaking at 18 h (Corney et al., 1990). Sequence analysis of 3B cDNA and genomic clones revealed two exons, 319bp and 341bp long, separated by an 82bp intron, which encode a 219 residue protein with no significant similarity to any other reported gene product. Transcription starts at an A residue 45bp upstream from the translation initiation codon, preceded by a TATA-like sequence and an oligo-dT stretch. The 5' flanking sequence of the 3B gene is extremely A + T rich but contains five G/C rich stretches, each approximately 7bp long, which have strong sequence similarity to the G boxes found upstream of other developmentally regulated Dictyostelium genes. Analysis of both 3B promoter-CAT reporter gene and 3B promoter-lacZ reporter gene constructs showed that 908bp of 5' flanking sequence is sufficient to confer correct developmental and cell-type specific regulation. Sequential 5' deletion analysis revealed that positive elements lie upstream of position -304 and that negative element(s) lie between positions -264 and -241. Nevertheless, a 286bp promoter fragment containing only sequence located downstream of position -241 directed essentially correct reporter gene expression. Point mutation analysis identified cis-acting elements within this 'sufficient' promoter fragment which activate transcription (G box V and psp-AT type sequences). A short (56bp) region of the 3B promoter sequence containing both G box IV and the psp-AT type element binds two types of nuclear factor, one present in cells throughout development and a second that appears only in late development with a time course comparable to 3B gene induction.

Melatonin for treatment of sleep disorders in children with developmental disabilities

This study explored the safety and efficacy of synthetic melatonin in the treatment of sleep problems in 20 children with developmental disabilities, in a randomized, double-blind, placebo-controlled 6-week trial of melatonin versus placebo. All but 2 children fell asleep more quickly when receiving melatonin than placebo. Overall, the greater the sleep latency (time to fall asleep) was at baseline or when receiving placebo, the more pronounced was the decrease in sleep latency with melatonin. The effect of melatonin on sleep latency was significant (P < .05). The duration of sleep while receiving melatonin was significantly greater than baseline (P < .007) but was not significantly different from placebo, and no difference in the number of awakenings was noted. No side effects were reported. Eleven of 18 parents (61%) correctly identified the weeks their child received melatonin. This study suggests that synthetic melatonin reduces sleep latency in children with developmental disabilities.

Identification of novel FLT-3 Asp835 mutations in adult acute myeloid leukaemia

Genomic DNA from 97 cases of adult de novo acute myeloid leukaemia (AML) was screened using polymerase chain reaction (PCR) and conformation-sensitive gel electrophoresis (CSGE) for FLT3 exon 20 mutations. Initial sequencing of four cases, representing the spectrum of CSGE abnormalities, revealed changes affecting codon Asp835 in three cases and also an intron 20 A to G change. In order to identify all possible Asp835 alterations, as well as the frequency of the intronic change nucleotide 2541 + 57 A-->G, the patient PCR products were digested with EcoRV and NlaIII respectively. Seven cases (7.2%) possessed a mutation affecting Asp835; these were identified, following DNA sequencing, as Asp835Tyr (n = 5), Asp835His (n = 1) and Asp835del (n = 1). Alterations affecting Asp835 were not found in 80 normal control DNA samples. In contrast, the nucleotide 2541 + 57 A-->G change was shown to be a polymorphism, with an allelic frequency of 0.24 for the G and 0.76 for the A allele. This study reports, for the first time, point mutations in the human FLT3 gene that, because of their homology with other class III receptor tyrosine kinase mutations, probably result in constitutive activation of the receptor.

Simultaneous choroidal melanoma and rhegmatogenous retinal detachment

A case is reported of a 30-year-old man who presented with the unusual combination of a unilateral inferonasal choroidal melanoma and an unassociated rhegmatogenous retinal detachment attributable to a large horseshoe tear in the superotemporal quadrant. Over 20 cases of simultaneous occurrence of these two phenomena have now been reported but this patient appears to be the youngest. The reports of this uncommon association are reviewed.

Is epidural analgesia associated with an improved outcome following open Nissen fundoplication?

Postoperative epidural analgesia is increasingly popular in paediatric practice, although evidence of its benefit is scarce. We performed a retrospective analysis of a series of 104 consecutive open Nissen fundoplications, to determine whether mode of analgesia, epidural (n=65) or opioid infusion (n=39), influenced certain outcome measures, including intensive care utilization, duration of hospital stay, morbidity and mortality. The two groups were similar in terms of demographic characteristics and associated pathologies. Overall, morbidity and mortality (2%) rates were low. Mean duration of hospital stay was significantly greater for the opioid group, compared to those receiving epidural analgesia (13 vs. 8 days, P < 0.05). The number of patients who remained in hospital for more than 7 days was also significantly greater in the opioid group. Accepting the limitations of a retrospective study, these data suggest that epidural analgesia might be associated with an improved outcome following Nissen fundoplication and this merits a prospective study.

Are aberrant BCR--ABL transcripts more common than previously thought?

We report the use of multiplex polymerase chain reaction (PCR), using 4% polyacrylamide gel electrophoresis (PAGE) for the detection of BCR-ABL transcripts in Philadelphia-positive disease. Three out of 50 cases [two out of 37 chronic myeloid leukaemia (CML), one out of 13 acute lymphoblastic leukaemia (ALL)] possessed rare breakpoints; an e19a2 and e13a3 in CML and an e1a3 in the ALL. We suggest that multiplex PCR using 4% PAGE and optimized for smaller transcript detection may lead to a higher detection rate of rare BCR-ABL breakpoints. Multiplex PCR, however, failed to distinguish e13a2 from e1a3 transcripts. Finally, the presence of e13a3 in CML supports the view that abl exon 2 sequences are unnecessary for the pathogenesis of 'classic' CML.

Results of liver transplantation for nodular regenerative hyperplasia

Liver transplantation has been performed in individuals with a pretransplant clinical diagnosis of cirrhosis but with nodular regenerative hyperplasia histologically. The purpose of this report is to investigate the results of liver transplantation in patients proven to have nodular regenerative hyperplasia post-transplant. A retrospective review was undertaken of four patients who underwent liver transplantation with a histologic diagnosis of nodular regenerative hyperplasia. All were felt to be cirrhotic on clinical grounds. Final histology of the explanted liver was confirmed by a single pathologist. Their ages ranged from 39 to 54 years, and three of the four were male. Three had pretransplant needle liver biopsies, two percutaneous and one transjugular. All revealed nonspecific reactive changes. Ultrasound and MRI were interpreted as consistent with cirrhosis in four of four and three of four cases, respectively. Portal vein flow was hepatopedal in three and absent in one. Pretransplant clinical characteristics and frequency were as follows: bleeding varices two, clinical ascites three, encephalopathy three, and impaired hepatic synthetic function two. All four patients underwent successful liver transplantation. There were no episodes of acute rejection. All are alive and well with normal graft function 2 to 4 years post-transplant. We conclude the following. 1) Patients with clinical end-stage liver disease due to underlying nodular regenerative hyperplasia can successfully undergo transplantation. 2) Nodular regenerative hyperplasia can present with signs and symptoms of liver failure, is difficult to diagnose by needle biopsy, and can be difficult to discriminate clinically from cirrhosis. 3) Although each case must be individually evaluated transplantation may be the optimal therapy in patients presenting with complications of liver failure.

FLT3 internal tandem duplication mutations in adult acute myeloid leukaemia define a high-risk group

Genomic DNA from 106 cases of adult de novo acute myeloid leukaemia (AML) was screened by polymerase chain reaction (PCR) and gel electrophoresis for FLT3 internal tandem duplication (ITD) mutations within the juxtamembrane (JM) domain. FLT3 mutations were detected in 14 cases (13.2%) and occurred in FAB types M1 (4 out of 14 cases), M3 (1 out of 10 cases), M4 (5 out of 37 cases) and M5 (4 out of 11 cases). Sequence analysis of four cases with abnormal PCR electrophoretic patterns revealed in frame duplications in the region of exon 11 of between 27 and 111 base pairs. Three are predicted to result in the tandem duplication of adjacent amino acid residues and one to result in a tandem duplication plus insertion of a novel amino acid motif. Statistical analysis showed the FLT3 mutations to be a strong prognostic factor, with patients lacking the mutation surviving significantly longer from diagnosis (mean 29.1 months) than those with an ITD (mean 12.8 months; P = 0.0002). Thirteen of the 14 patients with FLT3 mutations died within 18 months of diagnosis. FLT3 mutations were of prognostic significance in good risk disease (P = 0.04), as well as in patients with standard risk disease (P = 0.0096). This study demonstrates that the FLT3 ITD mutation occurs in a significant percentage of adult AML cases and is an important adverse prognostic factor that appears independent of conventional karyotypic findings.

Preoperative evaluation of living renal donors: comparison of CT angiography and MR angiography

PURPOSE

To compare computed tomographic (CT) angiography and magnetic resonance (MR) angiography for preoperative evaluation of living renal donors.

MATERIALS AND METHODS

Thirty-five living renal donors underwent preoperative contrast material-enhanced CT angiography and gadolinium-enhanced MR angiography. Each study was interpreted by two independent radiologists blinded to all other studies and to interpretations provided by other reviewers. Eighteen kidneys had surgical correlation.

RESULTS

CT demonstrated 33 supernumerary arteries in 19 patients, bilateral solitary arteries in 16 patients, and 18 proximal arterial branches in 16 patients. MR demonstrated 26 supernumerary arteries in 15 patients, bilateral solitary renal arteries in 20 patients, and 21 proximal arterial branches in 16 patients. Interobserver agreements for MR (kappa = 0. 74) and CT (kappa = 0.73) were similar to the agreement between MR and CT (kappa = 0.74). Among the kidneys chosen for nephrectomy, one small accessory artery and one proximal arterial branch were missed with CT and MR. Two of the accessory arteries suggested at CT were not found at nephrectomy. By averaging data for both modalities, supernumerary arteries were present in 49% of kidney donors and were bilateral in approximately 17%. Proximal arterial branches were present in 46% of kidney donors.

CONCLUSION

Preoperative CT and MR angiography of the renal arteries in renal donors demonstrate substantial agreement. Interobserver disagreement in the interpretation of CT and MR angiograms is related to 1-2-mm-diameter vessels.

Risperidone in the treatment of two very young children with autism

This report describes the use of risperidone in the treatment of two very young children with autistic disorder, a 29-month-old boy and a 23-month-old boy, respectively. These children presented with severe and persistent symptoms of aggression and irritability that had not responded to previous treatment. In both cases, risperidone significantly reduced aggression and improved social relatedness. One patient's treatment with risperidone was complicated by persistent tachycardia and QTc interval prolongation that was dose-related. Consideration should be given to the appropriate use of medication in the treatment of very young children with autism when other interventions do not prove helpful.

Genetic variation within and relatedness among wood and plains bison populations

There are two recognized subspecies of bison, wood (Bison bison athabascae) and plains (Bison bison bison) bison. The establishment of most bison populations from a small number of individuals has raised concerns about their genetic variation. To this end, 11 bison populations were surveyed with 11 microsatellite loci in order to calculate genetic variation and genetic distances. Mean number of alleles ranged between 3.18 at Antelope Island State Park (Utah) and 6.55 at Wood Buffalo National Park (Alberta and Northwest Territories). Mean heterozygosity ranged from 0.295 at Antelope Island State Park to 0.669 at Custer State Park (South Dakota). The amount of genetic variability present in the bison populations as measured by mean number of alleles and overall probability of identity was found to correlate with the number of founders for all sampled populations. The G-test for heterogeneity revealed some evidence for the existence of subpopulations at Wood Buffalo National Park, however very small genetic distances between these subpopulations suggest that nuclear material from the plains bison introduced into Wood Buffalo National Park has diffused throughout the park. Genetic distances between the sampled populations were generally larger between than within the two bison subspecies.

Genetic variation within and relatedness among wood and plains bison populations

There are two recognized subspecies of bison, wood (Bison bison athabascae) and plains (Bison bison bison) bison. The establishment of most bison populations from a small number of individuals has raised concerns about their genetic variation. To this end, 11 bison populations were surveyed with 11 microsatellite loci in order to calculate genetic variation and genetic distances. Mean number of alleles ranged between 3.18 at Antelope Island State Park (Utah) and 6.55 at Wood Buffalo National Park (Alberta and Northwest Territories). Mean heterozygosity ranged from 0.295 at Antelope Island State Park to 0.669 at Custer State Park (South Dakota). The amount of genetic variability present in the bison populations as measured by mean number of alleles and overall probability of identity was found to correlate with the number of founders for all sampled populations. The G-test for heterogeneity revealed some evidence for the existence of subpopulations at Wood Buffalo National Park, however very small genetic distances between these subpopulations suggest that nuclear material from the plains bison introduced into Wood Buffalo National Park has diffused throughout the park. Genetic distances between the sampled populations were generally larger between than within the two bison subspecies.Key words: Bison bison bison, Bison bison athabascae, DNA microsatellites, genetic variation, genetic relatedness.

Report from the National Transplantation Pregnancy Registry (NTPR): outcomes of pregnancy after transplantation

Specific data on pregnancies following transplantation continue to accrue in the National Transplantation Pregnancy Registry (NTPR) in each type of organ recipient, with the following conclusions: 1. While the majority of kidney recipients appear to tolerate pregnancy well, a small percentage develops rejection, graft dysfunction and/or graft deterioration. Overall, there is a slight increase in the mean postpartum creatinine level when compared with the prepregnancy level, which has been noted in previous investigations by the NTPR. One neonatal death attributed to thrombotic cardiomyopathy was noted in a set of twins of a tacrolimus-based kidney recipient, but no other death has been noted in any of the additional reports among the recipients given newer immunosuppression regimens. Follow-up of offspring of these recipients is ongoing. 2. No structural malformations have been noted among offspring exposed to mycophenolate mofetil, but exposures are limited. (5 mothers, 29 fathers). 3. Female liver recipients with biopsy-proven acute rejection during pregnancy appear to be at greater risk for both poorer newborn outcomes and recurrent rejection episodes. In the setting of acute rejection diagnosed during pregnancy, close attention is warranted, anticipating that birthweight may be lower and that a substantial percentage of these female recipients may have recurrent rejection episodes. 4. Pancreas-kidney grafts can maintain normoglycemia throughout pregnancy. A high incidence of maternal hypertension, prematurity and low birthweight have been noted, so, as in other recipient groups, these are high-risk pregnancies. Maternal pancreas and kidney function must be closely monitored. 5. No specific prepregnancy predictors of adverse outcomes have yet been identified among heart or lung recipients although none of the deaths among heart recipients in the NTPR database occurred within 2 years of delivery. When compared with other solid organ recipients, female lung recipients may face higher risks, particularly related to rejection. Whether prepregnancy factors can help to predict either heart or lung recipients at risk requires continued study. 6. No structural malformations or significant learning disabilities have been noted in follow-up of the offspring of CsA-treated females, the largest group of offspring followed to date with a mean age of 4-5 years. Continued surveillance of children will be essential to determine if effects become apparent as age-related developmental delays or other problems in immune function or fertility later in life. 7. Newer regimens as well as new combinations of agents will continue to be studied. It is essential that non-viable as well as viable pregnancy outcomes be reported to the registry (i.e., recipients with pregnancies that result in spontaneous abortion or termination should be included for study). True estimates of non-viable outcomes have been difficult to assess. Additionally, inclusion of reports of pathologic evaluations at delivery hospitals will be helpful to determine whether spontaneous abortions are a result of lethal malformations related to immunosuppressive or other medication exposure. Safety of pregnancy for parent and child remain the primary goals of the NTPR.

Determination of leucocyte antibody binding capacity (ABC): the need for standardization

The flow cytometric determination of antigen density, or cellular antibody binding capacity, is now an accepted technique for the characterization of cells in health and disease. In HIV infection, for example, antigen density changes in CD38 expression may be an important indicator of disease progression. Our experience of using one such method, Quantum Simply Cellular, which measures antibody binding capacity (ABC), has highlighted several technical factors which can affect the results. We report the influence of pH, incubation temperature and time, antibody fluorochrome and titre, as well as lysing reagent (FACS Lysing Solution v. Ortho-mune Lysing Reagent) on the ABC of anti-CD3, CD4 and CD8 of normal lymphocytes. In addition, the effect of single, double or triple-staining was assessed. The results indicate that the ABC values are influenced by all the variables studied. The pH range tested (6.0-9.0) demonstrated that pH 7.4 gave maximal binding. Furthermore, temperature also influenced the pH of the two lysing solutions, and thus potentially the ABC. Antibody concentration, fluorochrome and staining technique are also important factors with an observed difference of up to 458,855 ABC between the various fluorochromes. In addition a maximal difference of 130,119 ABC was observed between single and triple staining techniques. In conclusion, if antigen quantification is to be used in the clinical setting, an internationally standardized method is required to ensure the reproducibility of results from centre to centre. Our data suggests that single staining, using fluorescein isothiocynate (FITC) conjugated antibodies with all reagents at pH 7.4 + 0.1, with incubation and lysing carried out at 20 + 1 degrees C, could be used as a 'benchmark' method for ABC determination using the QSC system.

Fragile X syndrome

Fragile X syndrome is the most common form of inherited mental retardation. It is seen in people of all nationalities and in all areas of the world. Fragile X syndrome can be a devastating condition, as many boys are severely retarded and require multiple services. Treatment involves behaviour management techniques, appropriate school placement, community support for the family, and careful medical follow-up often including psychopharmacology. The genetics of fragile X syndrome is now understood, prenatal testing is available, and the disorder is preventable through appropriate genetic counselling. This review focuses on the neurobiology of fragile X syndrome, its clinical features and treatment.

Validation of three paediatric pain scores for use by parents

Twenty children undergoing general surgery and 20 children undergoing otorhinolaryngological surgery were simultaneously assessed on two occasions by a doctor and a parent using three pain scoring systems. The pain scoring systems used were the Objective Pain Score, a four point numerical score and a 100 mm visual analogue scale. There was a high correlation between the scores given by the doctor and by the parents for all three scoring systems with parents consistently giving slightly higher scores than the doctor. The correlation coefficients for parental and medical pain scores in recovery were 0.77 for the Objective Pain Score, 0.70 for the four point numerical score and 0.69 for the visual analogue scale (p < 0.01). At 1 h after leaving the recovery area the correlation coefficients were 0.81, 0.80 and 0.73 respectively (p < 0.01). These results suggest that parental scoring of pain in children will be useful in future audit and research of analgesic regimens, particularly in day-case surgery.

Evaluation of a novel stable whole blood quality control material for lymphocyte subset analysis: results from the UK NEQAS immune monitoring scheme

The UK NEQAS immune Monitoring Scheme (UK NEQAS) evaluates the performance of laboratories routinely performing T-lymphocyte subset analysis on HIV-infected individuals. The scheme originally issued fresh whole blood, but a significant problem was that of analyte stability, especially 36 h postphlebotomy. To circumvent this problem, we have developed a novel stabilisation procedure that ensures retention of leucocyte light scatter and immunological staining characteristics for up to 300 days. In addition, the stabilised whole blood preparation is fully compatible with flow cytometer technology, incorporating either whole blood lysis or "no wash, no lyse" techniques. The ranges of interlaboratory coefficient of variation for the stabilised material are now tighter than those previously obtained with fresh whole blood. Development of this novel material has enabled overseas laboratories to participate in the UK NEQAS immune Monitoring Scheme and could in the future lead to the production of reference and/or calibration reagents for leucocyte immunophenotyping.

Impact of serum lipids on long-term graft and patient survival after renal transplantation

The results after primary cadaveric renal transplantation in 665 consecutive patients were reviewed with respect to posttransplant serum lipids. Data were available for 182 of 665 patients on serum total cholesterol and triglycerides at 1 year posttransplant. Hypercholesterolemia (cholesterol > 200 mg/dl) developed in 141 of 182 patients (77%) and hypertriglyceridemia developed in 73 of 166 patients (44%). At 1 year posttransplant, hypercholesterolemia and hypertriglyceridemia both correlated with age at transplant (P = 0.0001, P = 0.01). Hypercholesterolemia and hypertriglyceridemia were also correlated with obesity as determined by body mass index (kg/m2) (P = 0.006, P = 0.01). Hypertriglyceridemia at 1 year posttransplant correlated with pretransplant triglyceride level (P = 0.006), but hypercholesterolemia did not correlate with pretransplant cholesterol level (P = 0.53). Hyperlipidemia was not correlated with cyclosporine (CsA) or prednisone dose (mg/kg), CsA trough levels, number of rejection episodes, or serum creatinine at 1 year. Despite significant differences in serum cholesterol and triglycerides, actuarial graft and patient survival were similar between the normolipidemic and hyperlipidemic groups.

Obesity as a risk factor after combined pancreas/kidney transplantation

The impact of pretransplant overweight/obesity was analyzed in a group of 268 consecutive primary pancreas renal transplant recipients. Obesity was defined as body mass index (BMI) greater than 27 kg/m2. BMI was available for 240 of the 268 patients. A total of 88% (212/240) of the patients had a BMI < or = 27 and 28/240 (12%) had BMI > 27. There were no significant differences in age, sex, or race between obese and nonobese patients. The incidence and degree of posttransplant hypertension, weight gain, increase in BMI, and hyperlipidemia did not differ on the basis of pretransplant BMI. Serum creatinine at one year posttransplant was slightly increased in obese patients, but the increase was not statistically significant. Cumulative prednisone dose (mg/kg) as well as cyclosporine (CsA) dose (mg/kg) at one year was not significantly different between obese and nonobese patients. However, there was a marginally significant negative correlation between BMI and one-year cumulative (mg/kg) prednisone dose (P = .06). Types and frequency of posttransplant complications were similar between obese and nonobese patients, although there was a slightly higher incidence of wound related complications in obese patients (11% vs. 6.8%) (P = NS). There was no difference in the frequency of acute rejection episodes in obese and nonobese patients. Actuarial patient survival was comparable between patients with BMI < or = 27 versus those with BMI > 27 (P = .10). However, actuarial graft survival, both pancreas and renal, were significantly decreased in patients with BMI > 27 (P = .029). The decrease in pancreas and kidney graft survival in obese patients could not be attributed to decreased "early" patient survival, increased incidence of perioperative or postoperative complications, differences in hypertension, acute rejection episodes, serum lipids, or immunosuppression dosage. The most common causes of graft loss were rejection and patient death in both obese and nonobese patients. After three years posttransplant, the decreased pancreas and renal graft survival in obese patients corresponded to decreased patient survival. The most common cause of patient death was cardiovascular complications in both obese and nonobese PKT recipients.

Circulating CD20dim T-lymphocytes increase with age: evidence for a memory cytotoxic phenotype

The CD20 antigen has been regarded as a B lineage specific, 35 kDa, non-glycosylated membrane phosphoprotein, which functions as either a Ca2+ ion channel or as a regulatory protein of such a channel. Weak expression of CD20 (CD20dim), however, has recently been reported on a sub-population of T lymphocytes. We present results which confirm the existence of a CD20dim T lymphocyte population and show that such cells have a reduced antibody-binding capacity, when compared to CD20bright B-cells (10337 +/- 642 and 346311 +/- 24264 respectively). In addition, CD20dim cell counts vary with age, with the highest levels occurring in octogenarians: cord blood 0.3 +/- 0.1% (n = 13), 20-60 year-old group 2.1 +/- 1.1% (n = 18) and individuals > or = 61 years of age 6.9 +/- 3.2% (n = 10) (P < 0.001). Further characterization of CD20dim T cells, using three colour flow cytometry, demonstrated a predominantly memory cytotoxic phenotype, in that the cells were CD8+CD28+CD45RO+T-CR alpha beta +CD38-HLA-DR-.

Typing and subtyping of influenza viruses in clinical samples by PCR

Type A and B influenza viruses can cause a wide spectrum of illness, and these viruses are responsible for considerable mortality and morbidity. Rapid typing of isolates is desirable when amantadine treatment or prophylaxis of contacts of type A influenza virus carriers is considered, but the available rapid techniques lack sensitivity and standard diagnostic methods require expansion of virus in tissue culture or embryonated hens' eggs. We developed a series of oligonucleotide primers able to detect, type, and subtype type A influenza viruses in a single reverse transcription-PCR. RNA was isolated from clinical specimens, and cDNA was generated with random primers. PCR was carried out with a mixture of primers specific for influenza viruses of types B, A/H1 and A/H3, and subtyping of the neuraminidase was carried out on the same cDNA template under identical conditions. Amplified products were detected by ethidium bromide staining of amplified products after agarose gel electrophoresis. When it was used to test 98 clinical specimens, this method was comparable to standard culture techniques in the detection, typing, and subtyping of influenza viruses.

Heterodyne detection of swept-carrier frequency-selective optical memory signals

Swept-carrier time-domain optical memories [Opt. Lett. 17, 535 (1992)] are unique in that memory output signals occur cotemporally with the excitation field (read field) responsible for their generation. We demonstrate that this fact provides for the convenient detection of memory signals through their heterodyne interference with the cotemporal read field. Memory implementation is dramatically simplified.

Experimental demonstration of swept-carrier time-domain optical memory

Swept-carrier time-domain optical memory [Opt. Lett. 17, 535 (1992)] has been proposed as a means of storing optical data streams in inhomogeneously broadened spectral recording materials. The process provides for full utilization of the material storage bandwidth regardless of the data rate and permits storage of data sequences with durations exceeding the material dephasing time. We report what we believe is the first experimental demonstration of this storage process. Our experiments, implemented with frequency-swept diode lasers and Tm(3+):YAG storage material, demonstrate single-event storage of 98-bit data streams whose duration is an order of magnitude longer than the material dephasing time.

Proteolytic processing of reovirus is required for adherence to intestinal M cells

Reovirus adheres specifically to apical membranes of mouse intestinal M cells and exploits M-cell transepithelial transport activity to enter Peyer's patch mucosa, where replication occurs. Proteolytic conversion of native reovirus to intermediate subviral particles (ISVPs) occurs in the intestine, but it is not known whether conversion is essential for interaction of virus with M cells. We tested the capacity of native virions, ISVPs, and cores (that lack outer capsid proteins) to bind to intestinal epithelial cells in vivo and found that only ISVPs adhered to M cells. Thus, intraluminal conversion of native reovirus to ISVPs is a prerequisite for M-cell adherence, and outer capsid proteins unique to ISVPs (either sigma 1 or products of mu 1) mediate interaction of virus with M-cell apical membranes.

Association of the reovirus S1 gene with serotype 3-induced biliary atresia in mice

A panel of serotype 3 (T3) reovirus strains was screened to determine their relative capacities to cause lethal infection and hepatobiliary disease following peroral inoculation in newborn mice. A wide range of 50% lethal doses (LD50s) was apparent after peroral inoculation of the different virus strains. Two of the strains, T3 Abney and T3 clone 31, caused mice to develop the oily fur syndrome associated with biliary atresia. The capacity to cause biliary atresia was not related to the capacity to cause lethal infection, however, because the LD50s of T3 Abney and T3 clone 31 were grossly disparate. Examination of liver and bile duct tissues revealed histopathologic evidence of biliary atresia and hepatic necrosis in T3 Abney-infected mice but not in mice inoculated with a T3 strain of similar virulence or with the hepatotropic T1 Lang strain. The consistency with which T3 Abney-infected mice developed biliary atresia-associated oily fur syndrome permitted us to determine the viral genetic basis of reovirus-induced biliary atresia. Analysis of reassortant viruses isolated from an in vitro coinfection with T3 Abney and T1 Lang indicated a strong association of the hepatobiliary disease-producing phenotype with the T3 Abney S1 gene, which encodes the viral cell attachment protein, sigma 1. Amino acid residues within the sigma 1 protein that were unique to disease-producing T3 strains were identified by comparative sequence analysis. Specific changes exist within two regions of the protein, one of which is thought to be involved in binding to host cell receptors. We hypothesize that changes within this region of the protein are important in determining the tropism of this virus for bile-ductular epithelium.