Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Optical pathlength measurements on adult head, calf and forearm and the head of the newborn infant using phase resolved optical spectroscopy

We have used an intensity modulated optical spectrometer, which measures the phase shift across tissue experienced by intensity modulated near-infrared light, to determine the absolute optical pathlength through tissue. The instrument is portable and takes only 5 s to record pathlength at four wavelengths (690 nm, 744 nm, 807 nm and 832 nm). The absolute pathlength divided by the known spacing between the light source and detector on the skin is the differential pathlength factor (DPF) which previous studies have shown is approximately constant for spacings greater than 2.5 cm. DPF results are presented for measurements on 100 adults and 35 newborn infants to determine the statistical variation on the DPF. All measurements were made at a frequency of 200 MHz with source-detector spacings of > 4 cm. Results at 807 nm show a DPF of 4.16(+/- 18.8%) for adult arm, 5.51(+/- 18%) for adult leg, 6.26(+/- 14.1%) for adult head and 4.99(+/- 9%) for the head of a newborn infant. A wavelength dependence was obtained for DPF on all tissues and a difference in DPF between male and female was observed for both the adult arm and leg. The results can be used to improve the quantitation of chromophore concentration changes in adults and newborn infants.

Cone-rod dystrophy due to mutations in a novel photoreceptor-specific homeobox gene (CRX) essential for maintenance of the photoreceptor

Genes associated with inherited retinal degeneration have been found to encode proteins required for phototransduction, metabolism, or structural support of photoreceptors. Here we show that mutations in a novel photoreceptor-specific homeodomain transcription factor gene (CRX) cause an autosomal dominant form of cone-rod dystrophy (adCRD) at the CORD2 locus on chromosome 19q13. In affected members of a CORD2-linked family, the highly conserved glutamic acid at the first position of the recognition helix is replaced by alanine (E80A). In another CRD family, a 1 bp deletion (E168 [delta1 bp]) within a novel sequence, the WSP motif, predicts truncation of the C-terminal 132 residues of CRX. Mutations in the CRX gene cause adCRD either by haploinsufficiency or by a dominant negative effect and demonstrate that CRX is essential for the maintenance of mammalian photoreceptors.

Measurement of cranial optical path length as a function of age using phase resolved near infrared spectroscopy

Near infrared spectroscopy (NIRS) has been used to measure concentration changes of cerebral hemoglobin and cytochrome in neonates, children, and adults, to study cerebral oxygenation and hemodynamics. To derive quantitative concentration changes from measurements of light attenuation, the optical path length must be known. This is obtained by multiplying the source/ detector separation by a laboratory measured differential path length factor (DPF) which accounts for the increased distance traveled by light due to scattering. DPF has been measured by time of flight techniques on small populations of adults and postmortem infants. The values for adults are greater than those for newborns, and it is not clear how to interpolate the present data for studies on children. Recent developments in instrumentation using phase resolved spectroscopy techniques have produced a bedside unit which can measure optical path length on any subject. We have developed an intensity modulated optical spectrometer which measures path length at four wavelengths. Two hundred and eighty three subjects from 1 d of age to 50 y were studied. Measurements were made at a fixed frequency of 200 MHz and a source detector separation of 4.5 cm. Results suggest a slowly varying age dependence of DPF, following the relation DPF690 = 5.38 + 0.049A0.877, DPF744 = 5.11 + 0.106A0.723, DPF807 = 4.99 + 0.067A0.814, and DPF832 = 4.67 + 0.062A0.819, where DPF690 is the DPF measured at 690 nm and A is age is expressed in years from full term. There was a wide scatter of values, however, implying that ideally DPF should be measured at the time of each study.

Quantitative analysis of the pyridinium crosslinks of collagen in urine using ion-paired reversed-phase high-performance liquid chromatography

A method has been developed for the simultaneous and rapid analysis of the 3-hydroxypyridinium crosslinks of mature collagen, pyridinoline and deoxypyridinoline, in samples of urine and tissue. After hydrolysis in 6 M HCl, samples were prefractionated by partition chromatography using columns packed with cellulose CF1. The appropriate fractions were freeze-dried and then subjected to high-performance liquid chromatography using a gradient system with 20 mM NH4Cl, pH 3.5, and acetonitrile, incorporating 1-octanesulfonic acid as an ion-pairing agent; the pyridinium crosslinks were detected fluorometrically. The limit of detection of both crosslinks was 1 pmol. The mean recoveries of added standard to samples ranged between 94.2 and 97.2%, and the reproducibility of the complete procedure was between 12 and 16%. An application of the method in the study of degenerative disorders of bone and connective tissue is illustrated.

JBrowse 2: a modular genome browser with views of synteny and structural variation

We present JBrowse 2, a general-purpose genome annotation browser offering enhanced visualization of complex structural variation and evolutionary relationships. It retains core features of JBrowse while adding new views for synteny, dotplots, breakpoints, gene fusions, and whole-genome overviews. It allows users to share sessions, open multiple genomes, and navigate between views. It can be embedded in a web page, used as a standalone application, or run from Jupyter notebooks or R sessions. These improvements are enabled by a ground-up redesign using modern web technology. We describe application functionality, use cases, performance benchmarks, and implementation notes for web administrators and developers.

Quantitative data on the magnitude of the systemic inflammatory response and its effect on micronutrient status based on plasma measurements

BACKGROUND

Plasma concentrations of several trace elements and vitamins decrease because of the systemic inflammatory response. Thus, low values do not necessarily indicate deficiency.

OBJECTIVE

The magnitude of this effect on plasma micronutrient concentrations was investigated to provide guidance on the interpretation of routine clinical results.

DESIGN

Between 2001 and 2011, the results (2217 blood samples from 1303 patients) of routine micronutrient screens (plasma zinc, copper, selenium, and vitamins A, B-6, C, and E) and all vitamin D results (4327 blood samples from 3677 patients) were extracted from the laboratory database. C-reactive protein concentrations were measured as a marker of the severity of inflammation and categorized into 6 groups; for each group, plasma micronutrient concentrations and percentage changes were calculated.

RESULTS

Except for copper and vitamin E, all plasma micronutrient concentrations decreased with increasing severities of the acute inflammatory response. For selenium and vitamins B-6 and C, this occurred with only slightly increased C-reactive protein concentrations of 5 to 10 mg/L. For each micronutrient, the change in plasma concentrations varied markedly from patient to patient. The magnitude of the effect was greatest for selenium and vitamins A, B-6, C, and D, for which the median plasma concentrations decreased by >40%.

CONCLUSIONS

The clinical interpretation of plasma micronutrients can be made only with knowledge of the degree of inflammatory response. A reliable clinical interpretation can be made only if the C-reactive protein is <20 mg/L (plasma zinc), <10 mg/L (plasma selenium and vitamins A and D), or <5 mg/L (vitamins B-6 and C).

Reducing sulfur compounds of the colon impair colonocyte nutrition: implications for ulcerative colitis

BACKGROUND

Mercaptides (sodium hydrogen sulfide and sodium methanethiol) and mercapto-fatty acid (sodium mercaptoacetate) are reducing agents that help to maintain anaerobic conditions in the colonic lumen. The metabolic effect of these agents on n-butyrate and glucose oxidation in human colonocytes is unknown.

METHODS

Isolated human colonocytes were prepared from 31 colectomy specimens, and generation of oxidative metabolites from [1-14C]n-butyrate and [6-14C]glucose was measured in the presence and absence of reducing agents. Injury to cells was judged by diminished production of metabolites.

RESULTS

The injurious action of mercaptides at all sites of the colon was of the order of sodium hydrogen sulfide > methanethiol > mercaptoacetate. Significant inhibition of n-butyrate (< 0.005) but not glucose oxidation was observed with sodium hydrogen sulfide in the ascending colon, splenic flexure, and rectosigmoid region. Hydrogen sulfide more significantly inhibited fatty acid oxidation in the rectosigmoid than in the ascending colon (P < 0.02).

CONCLUSIONS

Metabolic effects of sodium hydrogen sulfide on butyrate oxidation along the length of the colon closely mirror metabolic abnormalities observed in active ulcerative colitis, and the increased production of sulfide in ulcerative colitis suggests that the action of mercaptides may be involved in the genesis of ulcerative colitis.

Early open reduction and internal fixation of the disrupted pelvic ring

Early open reduction and internal fixation (ORIF) of extremity fractures in patients with multiple injuries has been demonstrated to be safe, improve survival, and decrease the incidence of respiratory failure. Complications leading to abandonment of planned operative fixation and death in several patients with pelvic fractures led us to initiate a policy of early ORIF of the disrupted pelvic ring. Early ORIF of the pelvis was performed in 15 multiply injured patients between May 1984 and August 1985. Patients ranged in age from 13 to 79 years, their Hospital Trauma Index-ISS scores ranged from 14 to 68, and number of preoperative transfusions ranged from 0 to 42. Types of fractures were A-P compression, two, lateral compression, one, vertical shear, seven, complex, two, and acetabulum with ring disruption, three. All patients were resuscitated, transported in pneumatic antishock garments, and evaluated by abdominal and pelvic CT scan (in two patients following celiotomy). Preoperative angiograms to assess retroperitoneal hemorrhage in eight patients resulted in identification and control of significant bleeding in five. The mean time from injury to pelvic stabilization was 38 hours. Seven patients underwent ORIF within the first 24 hours. In most cases simultaneous anterior and posterior internal fixation was performed with the patient in the lateral decubitus position. Excluding associated procedures, operative time averaged 5.1 hours. Intra-operative transfusions averaged 4 units (range, 0-11). Rigid fixation was achieved in all patients. Most patients were out of bed by the third postoperative day. No patient developed respiratory failure. Two patients developed wound infections. Modification of our technique has avoided this complication in the latter part of this series.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of urinary hydroxypyridinium crosslink measurements as resorption markers in metabolic bone diseases

Analyses of the urinary concentration relative to creatinine of the collagen crosslinks, pyridinoline (Pyd) and deoxy-pyridinoline (Dpd) were made in 47 patients with metabolic bone diseases to assess the validity of these assays as indicators of bone resorption. The mean values for patients with Paget's disease of bone, primary hyperparathyroidism and osteomalacia were significantly higher (P less than 0.001) than those for age-matched healthy individuals. During treatment of Paget's disease with bisphosphonates, there was a steady decline in the urinary concentration of the crosslinks to the normal range; this change occurred earlier than for serum alkaline phosphatase. There were significant correlations (P less than 0.01) between the concentrations of both crosslinks and the corresponding values for hydroxyproline. At lower crosslink concentrations, however, these relationships were less marked due to large variations in hydroxyproline values. The results show that measurements of urinary Pyd and Dpd provide clinically applicable indices of bone resorption that are more specific than other markers.

Diabetes UK evidence-based nutrition guidelines for the prevention and management of diabetes

A summary of the latest evidence-based nutrition guidelines for the prevention and management of diabetes is presented. These guidelines are based on existing recommendations last published in 2011, and were formulated by an expert panel of specialist dietitians after a literature review of recent evidence. Recommendations have been made in terms of foods rather than nutrients wherever possible. Guidelines for education and care delivery, prevention of Type 2 diabetes, glycaemic control for Type 1 and Type 2 diabetes, cardiovascular disease risk management, management of diabetes-related complications, other considerations including comorbidities, nutrition support, pregnancy and lactation, eating disorders, micronutrients, food supplements, functional foods, commercial diabetic foods and nutritive and non-nutritive sweeteners are included. The sections on pregnancy and prevention of Type 2 diabetes have been enlarged and the weight management section modified to include considerations of remission of Type 2 diabetes. A section evaluating detailed considerations in ethnic minorities has been included as a new topic. The guidelines were graded using adapted 'GRADE' methodology and, where strong evidence was lacking, grading was not allocated. These 2018 guidelines emphasize a flexible, individualized approach to diabetes management and weight loss and highlight the emerging evidence for remission of Type 2 diabetes. The full guideline document is available at www.diabetes.org.uk/nutrition-guidelines.

Bovids as indicators of Plio-Pleistocene paleoenvironments in east Africa

Reconstructions of the paleoenvironments of early hominids offer a framework for understanding hominid ecological and behavioral adaptations. Habitat reconstructions typically rely upon various biological or physical habitat indicators, and here we present reconstructions of the Plio-Pleistocene paleohabitats of Koobi Fora and Olduvai Gorge as based on fossil bovids (Artiodactyla: Bovidae). Bovids are the most common faunal element at most Neogene hominid and hominoid fossil localities and have been widely studied. This study addresses the functional morphology of the bovid femur through discriminant function analysis and provides additional support for the observation that certain features of the femur demonstrate clear correlations with the amount of vegetative cover in different modern habitats. The reconstructions for both Koobi Fora and Olduvai Gorge suggest that the full range of environments inhabited by living bovids was present during the Plio-Pleistocene. Koobi Fora appears to have had a somewhat higher percentage of more closed habitats than the relatively more open habitats of Olduvai Gorge. These habitat reconstructions are in broad agreement with other reconstructions based on a purely taxonomic approach to the bovid remains. Grounding our reconstructions of paleoenvironments in studies of functional morphology can help to develop a richer idea of the habitats and resources available to early hominids.

Identification of adiponectin as a novel hemopoietic stem cell growth factor

The hemopoietic microenvironment consists of a diverse repertoire of cells capable of providing signals that influence hemopoietic stem cell function. Although the role of osteoblasts and vascular endothelial cells has recently been characterized, the function of the most abundant cell type in the bone marrow, the adipocyte, is less defined. Given the emergence of a growing number of adipokines, it is possible that these factors may also play a role in regulating hematopoiesis. Here, we investigated the role of adiponectin, a secreted molecule derived from adipocytes, in hemopoietic stem cell (HSC) function. We show that adiponectin is expressed by components of the HSC niche and its receptors AdipoR1 and AdipoR2 are expressed by HSCs. At a functional level, adiponectin influences HSCs by increasing their proliferation, while retaining the cells in a functionally immature state as determined by in vitro and in vivo assays. We also demonstrate that adiponectin signaling is required for optimal HSC proliferation both in vitro and in long term hemopoietic reconstitution in vivo. Finally we show that adiponectin stimulation activates p38 MAPK, and that inhibition of this pathway abrogates adiponectin's proliferative effect on HSCs. These studies collectively identify adiponectin as a novel regulator of HSC function and suggest that it acts through a p38 dependent pathway.

Diabetes UK evidence-based nutrition guidelines for the prevention and management of diabetes

This article summarizes the Diabetes UK evidence-based guidelines for the prevention of Type 2 diabetes and nutritional management of diabetes. It describes the development of the recommendations and highlights the key changes from previous guidelines. The nutrition guidelines include a series of recommendations for the prevention of Type 2 diabetes, nutritional management of Type 1 and Type 2 diabetes, weight management, management of microvascular and macrovascular disease, hypoglycaemia management, and additional considerations such as nutrition support, end-of-life care, disorders of the pancreas, care of the older person with diabetes, nutrition provided by external agencies and fasting. The evidence-based recommendations were graded using the Scottish Intercollegiate Guidelines Network methodology and, in a small number of topic areas, where strong evidence was lacking, the recommendations were reached by consensus. The Diabetes UK 2011 guidelines place an emphasis on carbohydrate management and a more flexible approach to weight loss, unlike previous guidelines which were expressed in terms of recommendations for individual nutrient intakes. Additionally, the guidelines for alcohol have been aligned to national recommendations. The full evidence-based nutrition guidelines for the prevention and management of diabetes are available from: http://www.diabetes.org.uk/nutrition-guidelines.

Automated analysis of the pyridinium crosslinks of collagen in tissue and urine using solid-phase extraction and reversed-phase high-performance liquid chromatography

A fully automated method for assaying the collagen crosslinking amino acids, pyridinoline and deoxypyridinoline, in human urine samples or tissue hydrolysates is described. Samples were processed using a Gilson ASPEC system with solid-phase extraction of the crosslinks on columns containing 100 mg of microgranular cellulose. Introduction of an additional solvent step during sample preparation allowed direct analysis by reversed-phase HPLC and elimination of the drying step used previously in a manual method. Use of a synthetic pyridinoline derivative as internal standard enabled accurate quantification of the crosslinks by correcting for recoveries through the whole assay. Samples were analyzed in sequential mode with a total assay time of 30 min. The automated assay showed close correlation with the manual method for both free and total crosslink determinations in human urine (r > 0.97). Reproducibility was improved, as seen from replicate analyses of human urine (CV < 3% for automated pyridinoline measurement compared with 8-12% previously observed for the manual method). Crosslink excretion is the most useful marker of collagen degradation in metabolic bone diseases and arthritic disorders. The automated assay which has been developed is rapid, convenient, and reliable and will greatly facilitate the monitoring of urinary collagen crosslinks and their tissue levels in clinical investigations.

Measurement of bone collagen degradation in hyperthyroidism and during thyroxine replacement therapy using pyridinium cross-links as specific urinary markers

Urinary excretion of the bone collagen derived pyridinium cross-links pyridinoline (PYD) and deoxypyridinoline (DPD) was measured in 19 patients (4 M:15 F) with untreated thyrotoxicosis, and 20 pre-, and 20 postmenopausal women taking T4 100-200 micrograms daily for autoimmune hypothyroidism. Both PYD and DPD excretion (nanomoles per mmol creatinine) was elevated in the thyrotoxic patients compared to 287 controls; median 131 vs. 26 and 37.5 vs. 7.2, respectively, P less than 0.0001. In premenopausal women mean urinary pyridinium cross-link excretion and serum osteocalcin levels were similar in both T4-treated and matched control groups, despite suppression of serum TSH concentrations to below 0.1 mU/L in 14 of the 20 taking T4. In postmenopausal women mean (+/- 1 SE) urinary PYD excretion (nanomoles per mmol creatinine) was raised in those taking T4, relative to euthyroid controls; 40.0 +/- 2.7 vs. 32.1 +/- 2.3, P less than 0.05. DPD excretion and serum osteocalcin levels were also higher, but not significantly. When only the T4-treated women with a subnormal serum TSH were considered the difference in PYD excretion was more marked, and mean DPD excretion was also significantly elevated; 13.7 +/- 1.3 vs. 10.1 +/- 0.8, P less than 0.05.

CONCLUSION

bone collagen breakdown is increased in thyrotoxicosis, and in postmenopausal women taking sufficient T4 to suppress serum TSH. Similarly treated premenopausal women appear to be at lower risk.

A hypercoagulable state follows orthotopic liver transplantation

Orthotopic liver transplantation may be associated during the postoperative period with hepatic artery thrombosis, a catastrophic occurrence generally necessitating emergency retransplantation. To assess the contribution of the coagulation mechanism to this complication, the levels of procoagulant and anticoagulant proteins were followed in 41 liver transplant patients during the first 10 postoperative days. The mean activities of all procoagulant factors reach normal values on day 1 except for factors V and VII, which achieve normal activity by day 3. Supernormal levels of factor VIII activity and antigen are noted (peak values on day 5 of 334% +/- 113% and 481% +/- 260%, respectively). The anticoagulant proteins show delayed recovery, with deficient antithrombin III levels seen in 81% of patients on day 3 and 57% on day 5. Similarly, proteins C and S are subnormal in 24% and 21%, respectively on day 3, and 20% and 10%, respectively, on day 5. During this period, elevated levels of thrombin/antithrombin complexes are encountered, reflecting in vivo activation of the coagulation mechanism. Activated thrombin is, therefore, being generated at a time when a decrease in the major regulatory anticoagulant proteins exists. These data suggest an imbalance between the hemostatic and thrombotic mechanisms and indicate a sustained prothrombotic state that may contribute to the risk for hepatic artery thrombosis. Using a regimen of low-dose heparin and fresh frozen plasma infusion, no thromboses have been seen in 65 consecutive liver transplants.

Adenocarcinoma in situ of the uterine cervix: an experience with 100 cases

OBJECTIVE

The aim of this study was to ascertain whether cold knife conization alone for cervical adenocarcinoma in situ is safe.

METHODS

One hundred consecutive patients with a histologically proven adenocarcinoma in situ (AIS) of the cervix were studied from 1970 to 1992.

RESULTS

Ninety-two women presented with abnormal smears, and of these 56% contained abnormal glandular cells. Sixty-seven (74%) of 90 women who underwent colposcopy had an abnormal examination, but a glandular abnormality was suspected in only 19 (28%). In all, 80 cold knife conizations were performed. In 7, no abnormality was found following punch biopsy. The margins were free of disease in 55 (75%). The most commonly involved margin in the remainder was the apical. Conization was followed by hysterectomy in 20 women: in 8 of these the cone margins were free and residual disease was found in 2 of the extirpated uteri: as these were extramural cases, inadequate sampling could not be excluded. Of the 12 women where hysterectomy followed conization with diseased margins, 9 had residual disease in the hysterectomy specimen. The definitive therapy was cold knife conization in 56 patients, hysterectomy in 38, and electrocoagulation diathermy in 6. Follow-up of the 53 patients treated by conization alone ranging from 1 to 16 years, with a mean of 8 years (3 have been lost to follow-up) revealed no recurrence of AIS or adenocarcinoma to date.

CONCLUSION

It is concluded that cold knife conization is a safe therapeutic modality, provided that the cone biopsy has been adequately sampled and the margins are free.

Comparison of frontal plane trunk kinematics and hip and knee moments during anticipated and unanticipated walking and side step cutting tasks

BACKGROUND

Frontal plane trunk and lower extremity adjustments during unanticipated tasks are hypothesized to influence hip and knee neuromuscular control, and therefore, contribute to anterior cruciate ligament (ACL) injury risk. The aims of this study were to examine frontal plane trunk/hip kinematics and hip and knee moments (measures of neuromuscular control) during unanticipated straight and side step cut tasks.

METHODS

Kinematic and kinetic variables were collected while subjects performed two anticipated tasks, including walking straight (ST) and side step cutting (SS), and two unanticipated tasks (STU and SSU). Foot placement, thorax-pelvis-hip kinematic variables and hip and knee moments were calculated over the first 30% of stance.

FINDINGS

Hip abduction angles and knee moments were significantly affected by task and anticipation. Hip abduction angles decreased, by 4.0-7.6 degrees , when comparing the SSU task to the ST, STU and SS tasks. The hip abduction angles were associated with foot placement and lateral trunk orientation.

INTERPRETATION

Hip abduction angles and foot placement, not lateral trunk flexion influence trunk orientation. Anticipation influences hip and knee neuromuscular control and therefore may guide the development of ACL prevention strategies.

Sulphide impairment of substrate oxidation in rat colonocytes: a biochemical basis for ulcerative colitis?

1. Isolated colonic epithelial cells of the rat were incubated for 40 min with [6-14C]glucose and n-[1-14C]butyrate in the presence of 0.1-2.0 mmol/l NaHS, a concentration range found in the human colon. Metabolic products, 14CO2, acetoacetate, beta-hydroxybutyrate and lactate, were measured and injury to cells was judged by diminished production of metabolites. 2. Oxidation of n-butyrate to CO2 and acetoacetate was reduced at 0.1 and 0.5 mmol/l NaHS, whereas glucose oxidation remained unimpaired. At 1.0-2.0 mmol/l NaHS, n-butyrate and glucose oxidation were dose-dependently reduced at the same rate. 3. To bypass short-chain acyl-CoA dehydrogenase activity necessary for butyrate oxidation, ketogenesis from crotonate was measured in the presence of 1.0 mmol/l NaHS. Suppression by sulphide of ketogenesis from crotonate (-10.5 +/- 6.1%) compared with control conditions was not significant, whereas suppression of ketogenesis from n-butyrate (-36.00 +/- 5.14%) was significant (P = < 0.01). Inhibition of FAD-linked oxidation was more affected by NaHS than was NAD-linked oxidation. 4. L-Methionine (5.0 mmol/l) significantly redressed the impaired beta-oxidation induced by NaHS. Methionine equally improved CO2 and ketone body production, suggesting a global reversal of the action of sulphide. 5. Sulphide-induced oxidative changes closely mirror the impairment of beta-oxidation observed in colonocytes of patients with ulcerative colitis. A hypothesis for the disease process of ulcerative colitis is that sulphides may form persulphides with butyryl-CoA, which would inhibit cellular short-chain acyl-CoA deHydrogenase and beta-oxidation to induce an energy-deficiency state in colonocytes and mucosal inflammation.

Left ventricular remodelling and haemodynamic effects of multisite biventricular pacing in patients with left ventricular systolic dysfunction and activation disturbances in sinus rhythm: sub-study of the MUSTIC (Multisite Stimulationin Cardiomyopathies) trial

AIMS

To use echocardiography to determine early and late haemodynamic effects of atrio-biventricular (A-BiV) pacing on left ventricular (LV) function and their interrelations with exercise tolerance.

METHODS

Thirty-four patients with ejection fraction <35% (18 idiopathic dilated cardiomyopathy (DCM) and 16 ischaemic cardiomyopathy, in sinus rhythm and with intra-ventricular conduction delay (IVCD)) were implanted with transvenous A-BiV pacemakers. Echocardiographic measurements were compared before implantation, after 3 months A-BiV pacing, and 3 months inactive pacing (ventricular inhibited pacing at 40 beats x min(-1)as part of a crossover design, and at 9- and 12-month longitudinal follow-up.

RESULTS

Total isovolumic time (IVT) halved after 3 months A-BiV pacing (from 20.1+/-4.4 to 10.7+/-4.9s min(-1), P<0.001) and did not change thereafter. LV cavity size fell after 3 months (end-diastolic dimension (EDD) 7.3+/-0.8 to 6.8+/-0.8 cm, P<0.001, and end-systolic dimension (ESD) 6.2+/-0.8 to 5.9+/-0.8 cm, P<0.05), with a further fall in EDD and ESD (by 8.4+/-7.8 and 8.8+/-7.8mm, respectively, both P<0.001) after 12 months. Although not a primary end-point of the study, the 12-month reduction in LVEDD and LVESD was greater in idiopathic DCM (by 8.9 and 9.8mm, P<0.01, respectively) compared with ischaemic cardiomyopathy. The 6-min walk rose by 15% (P<0.01) and peak VO(2)by 10% (P<0.05) after 3 months, with no further increase by 12 months, and no difference between idiopathic DCM and ischaemic cardiomyopathy. The increase in peak VO(2)at 12 months correlated with the fall in ESD (r=0.47, P=0.03).

CONCLUSIONS

A-BiV pacing shortens total IVT, reduces LV cavity size, and increases exercise tolerance in patients with DCM and IVCD. Ischaemic cardiomyopathy does not affect the exercise response, although it does reduce the extent of reverse remodelling.

A diet rich in walnuts favourably influences plasma fatty acid profile in moderately hyperlipidaemic subjects

OBJECTIVE

To compare two low fat diets one rich in walnuts on parameters of lipid metabolism in a group of hyperlipidaemic subjects.

DESIGN

A randomised cross over study.

SETTING

Department of Human Nutrition, University of Otago, Dunedin, New Zealand

SUBJECTS

Twenty one men with mean (s.d.) levels of total and LDL cholesterol of 6.58 (0.60) and 4.63 (0.58) respectively.

INTERVENTIONS

For two periods of four weeks subjects were asked to consume two low fat diets (fat 30% total energy), one containing, on average, 78 g/d walnuts. Walnuts obtained through Lincoln University and the Walnut Growers Group (South Canterbury).

RESULTS

Participants reported a higher total fat intake on the walnut diet (38% compared with 30% on the low fat diet P < 0.01) The most consistent change in fatty acid profile of triacylglycerol, phospholipid and cholesterol ester on the walnut diet was a significant (P < 0.01) increase in linoleic acid. Triacylglycerol linolenate also increased significantly (P < 0.01). Total and LDL cholesterol were lower on both experimental diets than at baseline, 0.25 mmol/l and 0.36 mmol/l respectively on the walnut diet and 0.13 mmol/l and 0.20 mmol/l respectively on the low fat diet. High density lipoprotein cholesterol was higher on both the walnut and low fat diets when compared to baseline (0.15 mmol/l and 0.12 mmol/l, respectively). When comparing the walnut and low fat diets only apo B was significantly lower (P < 0.05) on the walnut diet.

CONCLUSIONS

Despite an unintended increase in the total fat intake on the walnut diet, fatty acid profile of the major lipid fractions showed changes which might be expected to reduce risk of cardiovascular disease. The reduction of apolipoprotein B suggests a reduction in lipoprotein mediated risk, the relatively low myristic acid content of both diets perhaps explaining the absence of more extensive differences in lipoprotein levels on the two diets.

A critical review of the potential impacts of marine seismic surveys on fish & invertebrates

Marine seismic surveys produce high intensity, low-frequency impulsive sounds at regular intervals, with most sound produced between 10 and 300Hz. Offshore seismic surveys have long been considered to be disruptive to fisheries, but there are few ecological studies that target commercially important species, particularly invertebrates. This review aims to summarise scientific studies investigating the impacts of low-frequency sound on marine fish and invertebrates, as well as to critically evaluate how such studies may apply to field populations exposed to seismic operations. We focus on marine seismic surveys due to their associated unique sound properties (i.e. acute, low-frequency, mobile source locations), as well as fish and invertebrates due to the commercial value of many species in these groups. The main challenges of seismic impact research are the translation of laboratory results to field populations over a range of sound exposure scenarios and the lack of sound exposure standardisation which hinders the identification of response thresholds. An integrated multidisciplinary approach to manipulative and in situ studies is the most effective way to establish impact thresholds in the context of realistic exposure levels, but if that is not practical the limitations of each approach must be carefully considered.

Sputum trace metals are biomarkers of inflammatory and suppurative lung disease

BACKGROUND

Induced sputum cytology and protein biomarkers can be used to assess airways inflammation. Increases in sputum iron have been described in inflammatory lung disease. We hypothesized that other sputum metals may be affected by airways inflammation and investigated their potential value as biomarkers.

METHODS

Sputum was obtained from 20 healthy control subjects and from patients with inflammatory pulmonary diseases (23 with cystic fibrosis [CF], 16 with bronchiectasis, 17 with asthma, and 23 with COPD), and iron, zinc, manganese, and copper were measured. Fourteen patients with CF were also studied through an exacerbation cycle.

RESULTS

Sputum zinc and iron were elevated in CF and non-CF bronchiectasis vs controls (P < .001, zinc; P < .01 iron). Manganese was elevated in asthma (P < .01) and bronchiectasis (P < .05) vs controls. Copper was elevated in CF vs controls (P < .05). Zinc decreased (P < .01) following treatment of CF exacerbation. In subjects with CF zinc levels correlated with other biomarkers.

CONCLUSIONS

These results suggest a relationship of high concentrations of total zinc and iron with airways inflammation in CF and non-CF bronchiectasis, with longitudinal changes being observed in CF. Further work is required to elucidate potential inflammatory mechanisms related to these observations.