Integrative phylogenetic, phylogeographic and morphological characterisation of the Unio crassus species complex reveals cryptic diversity with important conservation implications

The global decline of freshwater mussels and their crucial ecological services highlight the need to understand their phylogeny, phylogeography and patterns of genetic diversity to guide conservation efforts. Such knowledge is urgently needed for Unio crassus, a highly imperilled species originally widespread throughout Europe and southwest Asia. Recent studies have resurrected several species from synonymy based on mitochondrial data, revealing U. crassus to be a complex of cryptic species. To address long-standing taxonomic uncertainties hindering effective conservation, we integrate morphometric, phylogenetic, and phylogeographic analyses to examine species diversity within the U. crassus complex across its entire range. Phylogenetic analyses were performed using cytochrome c oxidase subunit I (815 specimens from 182 populations) and, for selected specimens, whole mitogenome sequences and Anchored Hybrid Enrichment (AHE) data on ∼ 600 nuclear loci. Mito-nuclear discordance was detected, consistent with mitochondrial DNA gene flow between some species during the Pliocene and Pleistocene. Fossil-calibrated phylogenies based on AHE data support a Mediterranean origin for the U. crassus complex in the Early Miocene. The results of our integrative approach support 12 species in the group: the previously recognised Unio bruguierianus, Unio carneus, Unio crassus, Unio damascensis, Unio ionicus, Unio sesirmensis, and Unio tumidiformis, and the reinstatement of five nominal taxa: Unio desectusstat. rev., Unio gontieriistat. rev., Unio mardinensisstat. rev., Unio nanusstat. rev., and Unio vicariusstat. rev. Morphometric analyses of shell contours reveal important morphospace overlaps among these species, highlighting cryptic, but geographically structured, diversity. The distribution, taxonomy, phylogeography, and conservation of each species are succinctly described.

Environmentally friendly splints for limb immobilisation: a systematic review

INTRODUCTION

Climate change is estimated to be the biggest global health threat of the 21st century, and has prompted calls to move away from processes in healthcare associated with high energy consumption and greenhouse gas emission. In musculoskeletal medicine, splints are widely used for limb immobilisation. These have typically been made from single-use materials such as gypsum, although in recent years purportedly environmentally friendly splints have been designed. In this systematic review, we set out to assess the clinical effectiveness of all commercially available environmentally friendly splinting materials, including Woodcast®.

METHODS

The AMED (Allied and Complementary Medicine Database), CINAHL® (Cumulative Index to Nursing and Allied Health Literature), Cochrane Central Register of Controlled Trials, Embase®, Emcare® and MEDLINE® databases were searched to identify studies assessing the clinical effectiveness of biodegradable and environmentally friendly splints prior to paper review and data extraction. Formal quantitative synthesis was not possible owing to the substantial heterogeneity in the study designs and outcome measures.

RESULTS

Six papers met the inclusion criteria, all investigating one particular splint material (Woodcast®). One was a case series, two were cohort studies and three were randomised controlled trials. Primary outcome measures were heterogeneous but the environmentally friendly splints were generally equivalent to traditional splint materials. Studies were mostly at a high risk of bias.

CONCLUSIONS

There is limited research assessing 'green' splints in practice although the data suggest similarity with existing materials and no substantial safety concerns. Further scrutiny of the clinical effectiveness and environmental credentials of such splints is also required.

Investigation of the safety and feasibility of AAV1/SERCA2a gene transfer in patients with chronic heart failure supported with a left ventricular assist device - the SERCA-LVAD TRIAL

The SERCA-LVAD trial was a phase 2a trial assessing the safety and feasibility of delivering an adeno-associated vector 1 carrying the cardiac isoform of the sarcoplasmic reticulum calcium ATPase (AAV1/SERCA2a) to adult chronic heart failure patients implanted with a left ventricular assist device. The SERCA-LVAD trial was one of a program of AAV1/SERCA2a cardiac gene therapy trials including CUPID1, CUPID 2 and AGENT trials. Enroled subjects were randomised to receive a single intracoronary infusion of 1 × 10¹³ DNase-resistant AAV1/SERCA2a particles or a placebo solution in a double-blinded design, stratified by presence of neutralising antibodies to AAV. Elective endomyocardial biopsy was performed at 6 months unless the subject had undergone cardiac transplantation, with myocardial samples assessed for the presence of exogenous viral DNA from the treatment vector. Safety assessments including ELISPOT were serially performed. Although designed as a 24 subject trial, recruitment was stopped after five subjects had been randomised and received infusion due to the neutral result from the CUPID 2 trial. Here we describe the results from the 5 patients at 3 years follow up, which confirmed that viral DNA was delivered to the failing human heart in 2 patients receiving gene therapy with vector detectable at follow up endomyocardial biopsy or cardiac transplantation. Absolute levels of detectable transgene DNA were low, and no functional benefit was observed. There were no safety concerns in this small cohort. This trial identified some of the challenges of performing gene therapy trials in this LVAD patient cohort which may help guide future trial design.

The relationship between temperature and hip and wrist fracture incidence

INTRODUCTION

Predicting when fracture incidence will rise assists in healthcare planning and delivery of preventative strategies. The aim of this study was to investigate the relationship between temperature and the incidence of hip and wrist fractures.

METHODS

Data for adults presenting to our unit with a hip or wrist fracture over a seven and eight-year period respectively were analysed. Incidence rates were calculated and compared with meteorological records. A Poisson regression model was used to quantify the relationship between temperature and fracture rate.

RESULTS

During the respective study periods, 8,380 patients presented with wrist fractures and 5,279 patients were admitted with hip fractures. All women (≥50 years: p<0.001; <50 years: p<0.001) and men aged ≥50 years (p=0.046) demonstrated an increased wrist fracture rate with reduced temperature. Men aged <50 years also had an increased wrist fracture rate with increased temperature (p<0.001).The hip fracture rate was highest in women aged ≥50 years but was not associated with temperature (p=0.22). In men aged ≥50 years, there was a significant relationship between reduced temperature and increased fracture rate (p<0.001).

CONCLUSIONS

Fragility fracture of the wrist is associated with temperature. Compared with an average summer, an additional 840 procedures are performed for wrist fractures during an average winter in our trust with an additional 798 bed days taken up at a cost of £3.2 million. The winter increase seen in male hip fracture incidence requires approximately 888 surgical procedures, with 18,026 bed days, and costs £7.1 million. Hip fracture incidence in older women is not related to temperature.

Proximal humerus fracture-dislocation managed by mini-open reduction and percutaneous screw fixation

BACKGROUND

We describe a minimally open reduction and percutaneous fixation technique for three- and four-part proximal humeral fracture-dislocations which preserves soft tissues.

METHODS

Eleven consecutive patients with three-and four-part proximal humeral fracture-dislocations (eight anterior, three posterior dislocations) were treated this way. The dislocation is reduced using a mini-open deltopectoral approach with a horizontal split in subscapularis. Fracture fragments are fixed with percutaneous screws. Constant and Oxford Shoulder Score were collected prospectively.

RESULTS

Mean age was 51 years (range 32-65). Mean follow-up was 36 months (range 24-72 months). At last follow-up mean Constant score was 75 (range 64-86) compared to 88 (range 85-92) for the uninjured shoulder. Mean Oxford shoulder score was 41 (range 34-46). One patient developed avascular necrosis. Screw back out was seen in three patients. These were removed under local anaesthesia. There were no screw penetrations of articular surface. One patient suffered a radial nerve neuropraxia which resolved.

CONCLUSION

These results are promising and comparable to published literature with other means of fixation for this complex problem. Due to minimal soft tissue dissection the complications rate is low.

Trends in paediatric distal radius fractures: an eight-year review from a large UK trauma unit

INTRODUCTION

This observational study investigated the incidence of distal radius fractures in children, to determine whether the rate is rising, the effect of seasonal variation on incidence and whether fracture type and rate of surgical intervention has changed, to help in determining costs for secondary care and to aid resource allocation.

MATERIALS AND METHODS

All paediatric patients(n = 6529) who sustained a distal radius fracture over an eight-year period (2007-2014) were identified. Poisson regression modelling was used to identify change in trends.

RESULTS

There was no change in distal radius fracture incidence, rate of surgical intervention (P = 0.36) or fracture type (P = 0.70). Overall incidence was 337 fractures per 100,000 patient/years. The highest fracture incidence was seen in older school boys (708 per 100,000 patient/years, P < 0.005). Overall fracture rate was lower in winter (P < 0.005). Incidence is highest in summer and the main variation is related to season.

DISCUSSION

These data can help to predict accurately the number of children presenting to the emergency department with wrist fractures depending on the time of year.

A systematic review and meta-analysis of interval training versus moderate-intensity continuous training on body adiposity

Interval training (including high-intensity interval training [HIIT] and sprint interval training [SIT]) is promoted in both scientific and lay media as being a superior and time-efficient method for fat loss compared with traditional moderate-intensity continuous training (MICT). We evaluated the efficacy of HIIT/SIT when directly compared with MICT for the modulation of body adiposity. Databases were searched to 31 August 2016 for studies with exercise training interventions with minimum 4-week duration. Meta-analyses were conducted for within-group and between-group comparisons for total body fat percentage (%) and fat mass (kg). To investigate heterogeneity, we conducted sensitivity and meta-regression analyses. Of the 6,074 studies netted, 31 were included. Within-group analyses demonstrated reductions in total body fat (%) (HIIT/SIT: -1.26 [95% CI: -1.80; -0.72] and MICT: -1.48 [95% CI: -1.89; -1.06]) and fat mass (kg) (HIIT/SIT: -1.38 [95% CI: -1.99; -0.77] and MICT: -0.91 [95% CI: -1.45; -0.37]). There were no differences between HIIT/SIT and MICT for any body fat outcome. Analyses comparing MICT with HIIT/SIT protocols of lower time commitment and/or energy expenditure tended to favour MICT for total body fat reduction (p = 0.09). HIIT/SIT appears to provide similar benefits to MICT for body fat reduction, although not necessarily in a more time-efficient manner. However, neither short-term HIIT/SIT nor MICT produced clinically meaningful reductions in body fat.

Exercise and ectopic fat in type 2 diabetes: A systematic review and meta-analysis

Ectopic adipose tissue surrounding the intra-abdominal organs (visceral fat) and located in the liver, heart, pancreas and muscle, is linked to cardio-metabolic complications commonly experienced in type 2 diabetes. A systematic review and meta-analysis was performed to determine the effect of exercise on ectopic fat in adults with type 2 diabetes. Relevant databases were searched to February 2016. Included were randomised controlled studies, which implemented≥4 weeks of aerobic and/or resistance exercise and quantified ectopic fat via magnetic resonance imaging, computed tomography, proton magnetic resonance spectroscopy or muscle biopsy before and after intervention. Risk of bias and study quality was assessed using Egger's funnel plot test and modified Downs and Black checklist, respectively. Of the 10,750 studies retrieved, 24 were included involving 1383 participants. No studies were found assessing the interaction between exercise and cardiac or pancreas fat. One study assessed the effect of exercise on intramyocellular triglyceride concentration. There was a significant pooled effect size for the meta-analysis comparing exercise vs. control on visceral adiposity (ES=-0.21, 95% CI: -0.37 to -0.05; P=0.010) and a near-significant pooled effect size for liver steatosis reduction with exercise (ES=-0.28, 95% CI: -0.57 to 0.01; P=0.054). Aerobic exercise (ES=-0.23, 95% CI: -0.44 to -0.03; P=0.025) but not resistance training exercise (ES=-0.13, 95% CI: -0.37 to 0.12; P=0.307) was effective for reducing visceral fat in overweight/obese adults with type 2 diabetes. These data suggest that exercise effectively reduces visceral and perhaps liver adipose tissue and that aerobic exercise should be a key feature of exercise programs aimed at reducing visceral fat in obesity-related type 2 diabetes. Further studies are required to assess the relative efficacy of exercise modality on liver fat reduction and the effect of exercise on pancreas, heart, and intramyocellular fat in type 2 diabetes and to clarify the effect of exercise on ectopic fat independent of weight loss.

Comparison of distal radius fracture intra-articular step reduction with volar locking plates and K wires: a retrospective review of quality and maintenance of fracture reduction

This study investigated the accuracy and maintenance of reduction of intra-articular steps achieved with closed reduction and percutaneous K wires and open reduction and a volar locking plate for the treatment of intra-articular distal radius fractures. We performed a retrospective review of 359 patients with an intra-articular fracture of their distal radius. Multivariate linear regression was undertaken to investigate the influence of multiple variables such as age, gender, initial displacement and treatment method on reduction despite differences between groups. A total of 36% of patients treated with K wires and 29% with volar locking plate had a step greater than or equal to 1 mm present on the first post-operative radiograph. A total of 23% treated with K wires and 28% with volar locking plate had a residual step of 1 mm or more on the last available radiograph. There was no difference identified between the two techniques for quality of initial reduction or persisting step on the last available radiographs. Step behaviour and further reduction of step post-operatively was similar for both treatment methods. Initial displacement and increased age influenced initial reduction. Initial fracture displacement shown radiologically was the only variable identified that influenced the persistence of a step on post-operative radiographs.

LEVEL OF EVIDENCE

IV.

Risk factors for intramedullary nail breakage in proximal femoral fractures: a 10-year retrospective review

INTRODUCTION Intramedullary nailing is a common treatment for proximal femoral fractures. Fracture of the nail is a rare but devastating complication that exposes often frail patients to complex revision surgery. We investigated which risk factors predict nail failure. METHODS We reviewed all cases of nail breakage seen over a 10-year period in a single busy trauma unit; 22 nail fractures were seen in 19 patients. Comparison was made with a group of 209 consecutive patients who underwent intramedullary fixation of a proximal femur fracture with no nail breakage over a 2-year period. RESULTS In the fractured nail group, mean age was 70.4 years (range 55-88 years).The mean time to fracture was 10 months (range 2.5-23 months). Logistical regression was used to show that low American Society of Anesthesiologists (ASA) score, subtrochanteric fracture and pathological fracture were independent risk factors for nail fracture. CONCLUSIONS Young patients with a low ASA score are at highest risk of nail breakage. We advise close follow-up of patients with these risk factors until bony union has been achieved. In addition, there may be merit in considering other treatment options, such as proximal femoral replacement, especially for those with pathological fracture with a good prognosis.

Metabolome variations in the Porphyromonas gingivalis vimA mutant during hydrogen peroxide-induced oxidative stress

The adaptability and survival of Porphyromonas gingivalis in the oxidative microenvironment of the periodontal pocket are indispensable for survival and virulence, and are modulated by multiple systems. Among the various genes involved in P. gingivalis oxidative stress resistance, vimA gene is a part of the 6.15-kb locus. To elucidate the role of a P. gingivalis vimA-defective mutant in oxidative stress resistance, we used a global approach to assess the transcriptional profile, to study the unique metabolome variations affecting survival and virulence in an environment typical of the periodontal pocket. A multilayered protection strategy against oxidative stress was noted in P. gingivalis FLL92 with upregulation of detoxifying genes. The duration of oxidative stress was shown to differentially modulate transcription with 94 (87%) genes upregulated twofold during 10 min and 55 (83.3%) in 15 min. Most of the upregulated genes (55%), fell in the hypothetical/unknown/unassigned functional class. Metabolome variation showed reduction in fumarate and formaldehyde, hence resorting to alternative energy generation and maintenance of a reduced metabolic state. There was upregulation of transposases, genes encoding for the metal ion binding protein transport and secretion system.

Acute effects of a high-volume resistance training session on lung function

AIM

The purpose of this study was to examine whether a high--volume compared to a low--volume whole--body resistance exercise session acutely impairs lung function.

METHODS

Fifteen competitive male bodybuilders (age 27.4 ± 5.4 y; body mass 89.7 ± 12.8 kg; stature 177.9 ± 4.8 cm), in a crossover trial, completed two resistance training protocols (high--volume: 5 sets per exercise; low--volume: 2 sets per exercise) and a control session (no exercise) on 3 separate occasions.

RESULTS

The physiological demands of the two resistance exercise sessions were significantly different as indicated by greater VE, VO2, and HR (P<0.05), and lower PETCO2 (P<0.05) responses for the majority of exercises during the high--volume compared to low--volume session. No significant differences were found for lung function measures (FVC, SVC, FEV1, FEV3, FEV6, IC, ERV, and MVV) between pre-- and post--session for the low--volume and high-volume sessions.

CONCLUSION

The findings suggest that the ventilatory muscle demands of a strenuous resistance exercise session are not great enough to acutely affect indices of lung function.

Complications after volar locking plate fixation of distal radius fractures

Volar locking plates are an increasingly popular treatment for distal radius fractures. We reviewed complications observed after volar locking plate fixation in a busy teaching hospital. The purpose of the study was to assess whether complication rates after volar locking plate use in general, routine trauma practice were higher than published literature from expert users. A retrospective review was carried out of patients treated with a volar locking plate between January 2009 and December 2010. The series included 206 procedures in 204 patients (77 males and 127 females) with mean age of 55 years (range 16-94). Surgery was performed by 18 different consultant surgeons and 11 registrars. A total of 22 complications were observed in 20 patients with an overall complication rate of 9.7%. Seven (3.4%) patients developed tendon problems including four (1.9%) tendon ruptures. Four (1.9%) patients required re-operation for metalwork problems; four patients developed complex regional pain syndrome (CRPS). Three fracture reduction problems were noted. A total of 16 further operations were carried out for complications. The overall complication rate was low even when surgery was done by many surgeons, suggesting that this is a safe and reproducible technique. This study provides information which can be used to counsel patients about risks, including those of tendon and metalwork problems. This allows patients to make an informed decision. Surgeons must have specific strategies to avoid these complications and remain vigilant so that these can be identified and managed early.

Fibula physeal fracture causing syndesmotic diastasis

We report an unusual physeal fibula fracture seen in a 12 year old child. The fragment was rotated and incarcerated in the distal tibiofibular joint causing syndesmotic diastasis. The fragment required open reduction and the fibula was stabilised with k-wires. The patient made an excellent recovery.

A systematic review and meta-analysis of the effect of aerobic vs. resistance exercise training on visceral fat

It is increasingly recognized that the location of excess adiposity, particularly increased deposition of visceral adipose tissue (VAT), is important when determining the adverse health effects of overweight and obesity. Exercise therapy is an integral component of obesity management, but the most potent exercise prescription for VAT benefit is unclear. We aimed to evaluate the independent and synergistic effects of aerobic exercise (AEx) and progressive resistance training (PRT) and to directly compare the efficacy of AEx and PRT for beneficial VAT modulation. A systematic review and meta-analysis was performed to assess the efficacy of exercise interventions on VAT content/volume in overweight and obese adults. Relevant databases were searched to November 2010. Included studies were randomized controlled designs in which AEx or PRT in isolation or combination were employed for 4 weeks or more in adult humans, where computed tomography (CT) or magnetic resonance imaging (MRI) was used for quantification of VAT pre- and post-intervention. Of the 12196 studies from the initial search, 35 were included. After removal of outliers, there was a significant pooled effect size (ES) for the comparison between AEx therapy and control (-0.33, 95% CI: -0.52 to -0.14; P < 0.01) but not for the comparison between PRT therapy and control (0.09, 95% CI: -0.17 to -0.36; P = 0.49). Of the available nine studies which directly compared AEx with PRT, the pooled ES did not reach statistical significance (ES = 0.23, 95% CI: -0.02 to 0.50; P = 0.07 favouring AEx). The pooled ES did not reach statistical significance for interventions that combined AEx and PRT therapy vs. control (-0.28, 95% CI: -0.69 to 0.14; P = 0.19), for which only seven studies were available. These data suggest that aerobic exercise is central for exercise programmes aimed at reducing VAT, and that aerobic exercise below current recommendations for overweight/obesity management may be sufficient for beneficial VAT modification. Further investigation is needed regarding the efficacy and feasibility of multi-modal training as a means of reducing VAT.

BCL2 mutations in diffuse large B-cell lymphoma

BCL2 is deregulated in diffuse large B-cell lymphoma (DLBCL) by the t(14;18) translocation, gene amplification and/or nuclear factor-κB signaling. RNA-seq data have recently shown that BCL2 is the most highly mutated gene in germinal center B-cell (GCB) DLBCL. We have sequenced BCL2 in 298 primary DLBCL biopsies, 131 additional non-Hodgkin lymphoma biopsies, 24 DLBCL cell lines and 51 germline DNAs. We found frequent BCL2 mutations in follicular lymphoma (FL) and GCB DLBCL, but low levels of BCL2 mutations in activated B-cell DLBCL, mantle cell lymphoma, small lymphocytic leukemia and peripheral T-cell lymphoma. We found no BCL2 mutations in GC centroblasts. Many mutations were non-synonymous; they were preferentially located in the flexible loop domain, with few in BCL2-homology domains. An elevated transition/transversions ratio supports that the mutations result from somatic hypermutation. BCL2 translocations correlate with, and are likely important in acquisition of, additional BCL2 mutations in GCB DLBCL and FL. DLBCL mutations were not independently associated with survival. Although previous studies of BCL2 mutations in FL have reported mutations to result in pseudo-negative BCL2 protein expression, we find this rare in de-novo DLBCL.

Effect of prolonged exercise and pre-exercise dietary manipulation on hepatic triglycerides in trained men

The purpose of this study was to examine the effect of exercise and pre-exercise dietary manipulation on hepatic triglyceride concentration (HTGC). HTGC was measured by proton magnetic resonance spectroscopy ((1)H-MRS) before and after 90 min of moderate intensity cycling in six endurance trained males following 67 h of mixed diet (M) and an isocaloric minimal carbohydrate (2%) high fat (83%) diet (HF). Diets were administered by balanced crossover design. Whole-body fat oxidation, plasma-free fatty acid (FFA), glycerol and triglyceride concentrations were significantly elevated during exercise in HF versus M (P < 0.05 for all). There was no significant treatment × time interaction for HTGC (P = 0.368). However, there was a significant net increase in HTGC (time effect) during the combined 6 h exercise and post-exercise period (P = 0.037). In conclusion, we observed no measurable net change in the hepatic triglyceride pool across a period involving a prolonged exercise bout. Furthermore, manipulation of pre-exercise dietary intake did not influence the interaction between the hepatic triglyceride concentration and exercise in lean trained men. This supports the contention that hepatic triglycerides do not meaningfully contribute to the high rate of fat oxidation observed during acute exercise, or the enhancement of this with regular exercise training and/or pre-exercise dietary manipulation.

The bcp gene in the bcp-recA-vimA-vimE-vimF operon is important in oxidative stress resistance in Porphyromonas gingivalis W83

The ability of Porphyromonas gingivalis to overcome oxidative stress in the inflammatory environment of the periodontal pocket is critical for its survival. We have previously demonstrated that the recA locus, which carries the bacterioferritin co-migratory protein (bcp) gene and has a unique genetic architecture, plays a role in virulence regulation and oxidative stress resistance in P. gingivalis. To further characterize the bcp gene, which was confirmed to be part of the bcp-recA-vimA-vimE-vimF operon, we created a P. gingivalis bcp-defective isogenic mutant (FLL302) by allelic exchange. Compared with the wild-type, FLL302 had a similar growth rate, black pigmentation, β-hemolysis and UV sensitivity. Although there was no change in the distribution of gingipain activity, there was a 30% reduction in both Arg-X and Lys-X activities in the mutant strain compared with the wild-type. When exposed to 0.25 mm hydrogen peroxide, P. gingivalis FLL302 was more sensitive than the wild-type. In addition, the cloned P. gingivalis bcp gene increased resistance to 0.25 mm hydrogen peroxide in a bcp-defective Escherichia coli mutant. The mutant also demonstrated decreased aerotolerance when compared with the wild-type. Porphyromonas gingivalis FLL302 and the wild-type strain had similar virulence profiles in a mouse model of virulence. These observations suggest that the bcp gene may play a role in oxidative stress resistance but has a decreased functional significance in the pathogenic potential of P. gingivalis.

Cholecystobronchial fistula secondary to adenomyomatosis of the gallbladder

A case of cholecystobronchial fistula secondary to adenomyomatosis of the gallbladder is described. A cholecystobronchial fistula is a very unusual cause of fistulation between the bronchial and biliary tree. This is only the fifth reported case in the English language literature.

Short-term suppression of plasma free fatty acids fails to improve insulin sensitivity when intramyocellular lipid is elevated

AIMS

Metabolic responses to manipulation of the plasma free fatty acid (FFA) concentration were assessed in six healthy men via cross-over design to determine whether FFAs independently influence insulin sensitivity.

METHODS

Intramyocellular lipid (IMCL) was measured by proton magnetic resonance spectroscopy and insulin sensitivity via frequently sampled intravenous glucose tolerance test (IVGTT) after 67 h of two identical low carbohydrate/high fat (LC) diets which were used to elevate IMCL and plasma FFAs. To uncouple the influence of FFAs and IMCL on insulin sensitivity, FFAs were suppressed 30 min prior to and during IVGTT in one treatment [LC + nicotinic acid (NA)] by NA ingestion.

RESULTS

Vastus lateralis IMCL was significantly elevated in LC (13.3 +/- 1.1 x 10(-3)) and LC + NA (13.5 +/- 1.1 x 10(-3)) (P < 0.01 for both), but was not different between conditions (P > 0.05). Plasma FFAs were raised in LC (0.79 +/- 0.08 mmol/l) and LC + NA (0.80 +/- 0.11 mmol/l) (P < 0.01 for both) and were significantly reduced by NA ingestion prior to (0.36 +/- 0.05 mmol/l, P < 0.01) and during IVGTT (P < 0.05) in LC + NA. Despite marked differences in plasma FFA availability, insulin sensitivity and glucose tolerance were not different between LC and LC + NA (P > 0.05 for both).

CONCLUSIONS

Plasma FFAs appear to exert no immediate effect on insulin sensitivity/glucose tolerance independent of their action on intracellular lipid moieties. Further research is required to elucidate the duration of FFA suppression required to restore insulin sensitivity following lipid-induced insulin resistance.

Effect of altered pre-exercise carbohydrate availability on selection and perception of effort during prolonged cycling

This study assessed the effect of altered carbohydrate (CHO) availability on self-selected work rate during prolonged time-trial cycling. Eight endurance-trained men undertook two experimental cycling time-trials after glycogen-depleting exercise and 2 days of: (a) high (9.3 +/- 0 g CHO kg(-1) day(-1)) (HC) and (b) low CHO intakes (0.6 +/- 0.1 g CHO kg(-1) day(-1)) (LC), via a double-blinded crossover design. All feedback regarding performance was removed during both exercise trials. Self-selected external power output was not different during the first 2 h of exercise between experimental conditions (P > 0.05), despite reported sensations of increased tiredness before and during exercise, significantly reduced whole body CHO oxidation (P < 0.05), plasma lactate concentrations (P < 0.05) and earlier onset of fatigue during exercise in LC versus HC. Perceived exertion was not different throughout exercise between conditions (P > 0.05). Mean power output declined significantly in LC versus HC (P < 0.05) after approximately 2 h of exercise, and was associated with significant reductions in cadence, heart rate and plasma glucose concentration (P < 0.05). These results demonstrate that when compared with time-trial cycling performed after a HC diet, reduced CHO availability does not initially alter self-selected work rate in endurance athletes who are deceived of their CHO status prior to exercise. This finding suggests that reduced work rate during exercise following lowered CHO intake may, in part, be a consequence of the subject's awareness of dietary CHO restriction rather than solely a physiologically mediated action. Further research is required to distinguish the influence of circulating glucose and peripheral glycogen availability on pacing strategy during prolonged exercise.

Energy well spent fighting the diabetes epidemic

As the global burden of type 2 diabetes increases, medical science races to comprehensively understand its molecular aetiology. We suggest that the apparent struggle to seek a pharmacological or molecular victory to the diabetes epidemic is a flawed strategy given that evolution has already provided us with the best medicine. Recent molecular evidence highlights the interaction between muscle fatty acid kinetics in dictating whole body insulin action. Insights from an evolutionary perspective suggest that the ability of the body to evoke insulin resistance and store energy as fat within muscle cells is a normal physiological response to aid our survival during food or carbohydrate scarcity, but this 'hunter-gatherer physiology' predisposes to diabetes in a modern environment characterized by ample food availability and muscle inactivity. We contend that the true value of physical activity in the prevention and treatment of insulin resistance has been missed by the medical community because scientific investigation has been constructed upon physical activity recommendations that were never intended for this purpose. These recommendations provide a level of metabolic stress insufficient to be compatible with the expectations of our genes.

8-oxo-7,8-dihydroguanine is removed by a nucleotide excision repair-like mechanism in Porphyromonas gingivalis W83

A consequence of oxidative stress is DNA damage. The survival of Porphyromonas gingivalis in the inflammatory microenvironment of the periodontal pocket requires an ability to overcome oxidative stress caused by reactive oxygen species (ROS). 8-oxo-7,8-dihydroguanine (8-oxoG) is typical of oxidative damage induced by ROS. There is no information on the presence of 8-oxoG in P. gingivalis under oxidative stress conditions or on a putative mechanism for its repair. High-pressure liquid chromatography with electrochemical detection analysis of chromosomal DNA revealed higher levels of 8-oxoG in P. gingivalis FLL92, a nonpigmented isogenic mutant, than in the wild-type strain. 8-oxoG repair activity was also increased in cell extracts from P. gingivalis FLL92 compared to those from the parent strain. Enzymatic removal of 8-oxoG was catalyzed by a nucleotide excision repair (NER)-like mechanism rather than the base excision repair (BER) observed in Escherichia coli. In addition, in comparison with other anaerobic periodontal pathogens, the removal of 8-oxoG was unique to P. gingivalis. Taken together, the increased 8-oxoG levels in P. gingivalis FLL92 could further support a role for the hemin layer as a unique mechanism in oxidative stress resistance in this organism. In addition, this is the first observation of an NER-like mechanism as the major mechanism for removal of 8-oxoG in P. gingivalis.

Alkyl hydroperoxide peroxidase subunit C (ahpC) protects against organic peroxides but does not affect the virulence of Porphyromonas gingivalis W83

The cloned Porphyromonas gingivalis alkyl hydroperoxide reductase (ahpC) gene complemented an ahpC defect in Escherichia coli. To study the role of ahpC in protecting against oxidative stress in P. gingivalis a 1.8 kb fragment containing the ahpC gene was amplified from the chromosome of P. gingivalis W83. This gene was insertionally inactivated using the ermF-ermAM antibiotic resistance cassette and used to create a ahpC-deficient mutant by allelic exchange. One mutant strain, designated FLL141, demonstrated no change in the growth rate, black pigmentation, beta-hemolysis or level of proteolytic activity compared to the parent strain. Although P. gingivalis FLL141 was more sensitive to hydrogen peroxide than the parent strain, there was no change in its virulence potential in the mouse model compared to the wild-type strain. These findings suggest that the ahpC gene plays a role in peroxide resistance in P. gingivalis but does not contribute significantly to virulence.

Insulin resistance and elevated triglyceride in muscle: more important for survival than "thrifty" genes?

Elevated intramyocellular triglyceride (IMTG) is strongly associated with insulin resistance, though a cause and effect relationship has not been fully described. Insulin sensitivity and IMTG content are both dynamic and can alter rapidly in response to dietary variation, physical activity and thermoregulatory response. Physically active humans (athletes) display elevated IMTG content, but in contrast to obese persons, are insulin sensitive. This paradox has created confusion surrounding the role of IMTG in the development of insulin resistance. In this review we consider the modern athlete as the physiological archetype of the Late Palaeolithic hunter-gatherer to whom the selection pressures of food availability, predation and fluctuating environmental conditions applied and to whom the genotype of modern man is virtually identical. As food procurement by the hunter-gatherer required physical activity, "thrifty" genes that encouraged immediate energy storage upon refeeding after food deprivation (Neel, 1962) must have been of secondary importance in survival to genes that preserved physical capacity during food deprivation. Similarly genes that enabled survival during cold exposure whilst starved would be of primary importance. In this context, we discuss the advantage afforded by an elevated IMTG content, and how under these conditions, a concomitant muscle resistance to insulin-mediated glucose uptake would also be advantageous. In sedentary modern man, adiposity is high and skeletal muscle appears to respond as if a state of starvation exists. In this situation, elevated plasma lipids serve to accrue lipid and induce insulin resistance in skeletal muscle. Reversal of this physiological state is primarily dependent on adequate contractile activity, however, in modern Western society, physical inactivity combined with abundant food and warmth has rendered IMTG a redundant muscle substrate.

Intramyocellular triacylglycerol in prolonged cycling with high- and low-carbohydrate availability

Vastus lateralis intramyocellular lipid (IMCL) content was assessed by (1)H-magnetic resonance spectroscopy before and after prolonged time trial cycling bouts of approximately 3-h duration. Six highly trained male cyclists completed a double-blind, randomized, crossover design of two experimental trials after a strenuous exercise bout and 48 h of high (HC) (9.32 +/- 0.08 g. kg(-1). day(-1)) and low (LC) (0.59 +/- 0.21 g. kg(-1). day(-1)) dietary carbohydrate. Resting IMCL content was significantly higher after LC vs. HC (P < 0.01) and was reduced during exercise by 64 and 57%, respectively. IMCL was not different between conditions after exercise (P > 0.05). The approximately twofold increase in IMCL degradation in LC compared with HC suggests that higher rates of whole body lipid metabolism in LC were in part attributable to a greater IMCL utilization. Four subjects experienced reductions of IMCL in excess of 70% during exercise. To our knowledge, this is the first study to report near depletion of IMCL during prolonged cycling, indicating that IMCL, presumably the triacylglycerol component, may be exhausted by prolonged strenuous exercise.

Toward a new synthesis: population genetics and evolutionary developmental biology

Despite the recent synthesis of developmental genetics and evolutionary biology, current theories of adaptation are still strictly phenomenological and do not yet consider the implications of how phenotypes are constructed from genotypes. Given the ubiquity of regulatory genetic pathways in developmental processes, we contend that study of the population genetics of these pathways should become a major research program. We discuss the role divergence in regulatory developmental genetic pathways may play in speciation, focusing on our theoretical and computational investigations. We also discuss the population genetics of molecular co-option, arguing that mutations of large effect are not needed for co-option. We offer a prospectus for future research, arguing for a new synthesis of the population genetics of development.

Rapid speciation via parallel, directional selection on regulatory genetic pathways

Regulatory genetic pathways are ubiquitous in organisms and play a central role in the realization of the phenotype during development. We explored the proposition that these pathways can provide a plausible source of the epistatic variation that has been implicated in the evolution of postzygotic reproductive isolation. We modeled gene regulation as a matching function between the product of one locus and the promoter site of the next locus in the pathway, with binding strength determining the amount of product. When the phenotype is subject to parallel selection in a pair of independent populations, we find that the fitnesses of F(1)and F(2)hybrids often drop to very low values as the populations respond in genetically different and incompatible ways. The simulations support the predictions of the analytical models. Hybrid fitness reduction occurs more often as the number of loci in the pathway increases, and as the binding site interactions become more complex. Less hybrid fitness reduction is seen when the populations start with imperfect binding in the pathway. In contrast, when we constructed the phenotype without gene regulation using multiplicative rules, isomorphic to the additive phenotype commonly assumed in evolutionary models, we found no appreciable F(1)fitness reduction and only slight F(2)fitness reduction. The interaction of genetic drift and mutation, even at very high rates, did not reduce hybrid fitness at all on the time-scales we considered. Clearly, the evolution of regulatory genetic pathways can play an important role in speciation, but much more empirical information is needed on the effect of allelic variability in regulatory site interactions before this role is fully understood.

Three words three shapes: A clinical test of memory

Three Words - Three Shapes was designed as an easy "bedside" test for elderly patients that assesses verbal and nonverbal memory within the same modality. In the present study, it was administered to patients with probable Alzheimer's disease (PRAD), a control group of non-demented older subjects (NC) and a group of patients with Korsakoff's amnesia (KA). Incidental recall and several other measures of learning, retention and recognition differentiated control from PRAD and KA subjects. PRAD and KA subjects' performance was similar, but there were some material-specific interactions. This test is relatively easy and some of the derived measures could prove useful in staging amnesia progression beyond the earliest stages of PRAD when more difficult tests yield floor effects.

Validity of unbound digoxin measurements by immunoassays in presence of antidote (Digibind)

Measurement of unbound digoxin in presence of Fab fragments may be useful in management of overdoses. The analysis can be performed on serum directly or on ultrafiltrate of serum. The architecture of the immunoassay may influence the validity of results obtained using these two approaches. We tested this hypothesis by preparing serum mixtures containing various concentrations of digoxin and Digibind and analyzed them by the immunoassays before and after ultrafiltration. Four samples collected from Digibind-treated patients were also analyzed before and after ultrafiltration. The slopes and the y-intercepts of the measured versus the expected values for serum and its ultrafiltrate overlapped for the MEIA digoxin assay. For other three immunoassays tested (ACS:180, Stratus, and On-Line), either the slope or the intercept for measured versus the expected results for serum were significantly different (P < 0.05) than those for ultrafiltrate. Following addition of digoxin and Digibind, differences in results for serum analyzed directly or after ultrafiltration were < 0.50 ng/ml. Comparable samples from digoxin-overdosed patients treated with Digibind had differences of > 1.0 ng/ml. Previous claims reporting direct analysis of digoxin in presence of antidote but not having used patient samples for validation should be revisited. To date, analysis of serum ultrafiltrate by an immunoassay proven not to have matrix bias remains the most accurate approach in measuring unbound digoxin in presence of antidote.

A two-component affinity chromatography purification of Helix pomatia arylsulfatase by tyrosine vanadate

The inhibition of Helix pomatia arylsulfatase by the synergistic combination of N-acetyl-l-tyrosine ethyl ester and vanadate has been extended to affinity chromatography for purification. In the presence of vanadate, l-tyrosine ethyl ester (TEE), immobilized on CH-Sepharose 4B retained arylsulfatase from the digestive juice or lyophilized powder of H. pomatia. No enzyme was retained without vanadate or with arsenate or phosphate. Arylsulfatase was eluted from the column matrix by removing the vanadate to less than 50 microM with buffer containing EDTA to chelate the vanadate. Escherichia coli alkaline phosphatase and potato acid phosphatase, two enzymes which are inhibited by vanadate but not by the vanadate-TEE complex, were not retained by the immobilized TEE under any conditions used. The sulfatase activity was completely separated from contaminating glucuronidase activity present in the crude enzyme extracts. The Ki for the immobilized vanadate-TEE system was found to be 5.0 x 10(-7) M with a capacity of 25 mg/ml swollen gel. A purification of greater than 40-fold from the lyophilized powder of H. pomatia (Sigma Type H-5) was achieved using this technique. The Ki/Keq of other phenols with vanadate were determined in a 96-well plate format as an example of a rapid screening technique that could be extended to other phosphoryl and sulfuryl-transfer enzyme classes.

Simultaneous rapid measurement of whole blood myoglobin, creatine kinase MB, and cardiac troponin I by the triage cardiac panel for detection of myocardial infarction

This multicenter study evaluated the Biosite Triage(R) Cardiac Panel as a quantitative, multimarker, whole blood system for the detection of acute myocardial infarction (MI). Optimum cutoffs for the discrimination of acute MI (n = 192 patients, 59 with MI) as determined by ROC curve analyses were as follows: 0.4 microgram/L for cardiac troponin I (cTnI); 4.3 microgram/L for the creatine kinase MB isoenzyme (CK-MB); and 107 microgram/L for myoglobin. The Triage Panel showed the following concordances for detection or rule-out of MI compared with established devices: cTnI >89%; CK-MB >81%; myoglobin >69%. No significant differences were present between methods for the same marker. Diagnostic efficiencies demonstrated comparable sensitivities and specificities for the diagnosis of MI in patients presenting with symptoms compared with the Dade, Beckman, and Behring CK-MB, cTnI, and myoglobin assays; the ratio of sensitivity to specificity for each marker was as follows: cTnI, 98%:100%; CK-MB, 95%:91%; myoglobin, 81%:92%. The areas under the ROC curves for the Biosite myoglobin, CK-MB, and cTnI were 0.818, 0.905, and 0.970, respectively; the areas were significantly different, P <0.05. In patients with skeletal muscle injury and renal disease, the Triage cTnI showed 94% and 100% specificity, respectively. The Triage panel offers clinicians a whole blood, point-of-care analysis of multiple cardiac markers that provides excellent clinical sensitivity and specificity for the detection of acute MI.

The population genetics of synthetic lethals

Synthetic lethals are variants at different loci that have little or no effect on viability singly but cause lethality in combination. The importance of synthetic lethals and, more generally, of synthetic deleterious loci (SDL) has been controversial. Here, we derive the expected frequencies for SDL under a mutation-selection balance for the complete haploid model and selected cases of the diploid model. We have also obtained simple approximations that demonstrate good fit to exact solutions based on numerical iterations. In the haploid case, equilibrium frequencies of carrier haplotypes (individuals with only a single mutation) are comparable to analogous single-locus results, after allowing for the effects of linkage. Frequencies in the diploid case, however, are much higher and more comparable to the square root of the single-locus results. In particular, when selection operates only on the double-mutant homozygote and linkage is not too tight, the expected frequency of the carriers is approximately the quartic root of the ratio between the mutation rate and the selection coefficient of the synthetics. For a reasonably wide set of models, the frequencies of carriers can be on the order of a few percent. The equilibrium frequencies of these deleterious alleles can be relatively high because, with SDL, both dominance and epistasis act to shield carriers from exposure to selection. We also discuss the possible role of SDL in maintaining genetic variation and in hybrid breakdown.

Quality of life and later adverse health outcomes in patients with suspected heart attack

We tested the hypothesis that low quality of life (QOL) after discharge from hospital with ischaemic heart disease (IHD) is associated with higher rates of later adverse outcomes (death and subsequent hospital admission for acute myocardial infarction or congestive cardiac failure). Three hundred and seventy-five patients previously enrolled in an intervention study which assessed QOL six months after hospitalisation were followed up for an additional 18 months. The rates of adverse outcomes increased as QOL decreased (high QOL 9%; moderate 18%; low 28%). After adjustment for known prognostic factors, the risk of an adverse outcome was still higher in 'low' and 'moderate' compared to 'high' QOL subjects (low QOL adjusted OR = 2.6, 95% CI = 1.2-5.8; moderate 1.9, 0.8-4.2). In conclusion, QOL after discharge from hospital appears to be an independent predictor of later morbidity and mortality.

Prediction of patient nonadherence with home-based exercise for cardiac rehabilitation: the role of perceived barriers and perceived benefits

BACKGROUND

The aim of this study was to determine whether cardiac patients' perceptions of the barriers to and benefits of home exercise while in hospital and 6 weeks after discharge are predictive of nonadherence with regular home exercise 6 months after discharge from hospital.

METHODS

A prospective longitudinal study of 459 patients age 75 years or less and discharged from any of six public hospitals in the Lower Hunter Region of New South Wales, Australia, with a diagnosis of acute myocardial infarction or angina was conducted.

RESULTS

Multivariate logistic regression analysis, using data provided by 281 (61.2%) patients, showed that cardiac patients' perceptions of the benefits of and the physical environment and time barriers to home exercise while in hospital were predictive of nonadherence with regular home exercise 6 months after discharge from hospital, after adjustment for potential confounders. Six weeks after discharge from hospital, patients' perceptions of the enjoyment and time barriers to home exercise were predictive of nonadherence at follow-up, after adjustment for potential confounders.

CONCLUSIONS

Cardiac patients' perceptions of the barriers to and benefits of home exercise may be modifiable sources of nonadherence. A randomized controlled trial is required to confirm and extend upon these findings.