Subcortical volumes across the lifespan: Data from 18,605 healthy individuals aged 3-90 years

Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resources of the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Consortium to examine age-related trajectories inferred from cross-sectional measures of the ventricles, the basal ganglia (caudate, putamen, pallidum, and nucleus accumbens), the thalamus, hippocampus and amygdala using magnetic resonance imaging data obtained from 18,605 individuals aged 3-90 years. All subcortical structure volumes were at their maximum value early in life. The volume of the basal ganglia showed a monotonic negative association with age thereafter; there was no significant association between age and the volumes of the thalamus, amygdala and the hippocampus (with some degree of decline in thalamus) until the sixth decade of life after which they also showed a steep negative association with age. The lateral ventricles showed continuous enlargement throughout the lifespan. Age was positively associated with inter-individual variability in the hippocampus and amygdala and the lateral ventricles. These results were robust to potential confounders and could be used to examine the functional significance of deviations from typical age-related morphometric patterns.

Cortical thickness across the lifespan: Data from 17,075 healthy individuals aged 3-90 years

Delineating the association of age and cortical thickness in healthy individuals is critical given the association of cortical thickness with cognition and behavior. Previous research has shown that robust estimates of the association between age and brain morphometry require large-scale studies. In response, we used cross-sectional data from 17,075 individuals aged 3-90 years from the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Consortium to infer age-related changes in cortical thickness. We used fractional polynomial (FP) regression to quantify the association between age and cortical thickness, and we computed normalized growth centiles using the parametric Lambda, Mu, and Sigma method. Interindividual variability was estimated using meta-analysis and one-way analysis of variance. For most regions, their highest cortical thickness value was observed in childhood. Age and cortical thickness showed a negative association; the slope was steeper up to the third decade of life and more gradual thereafter; notable exceptions to this general pattern were entorhinal, temporopolar, and anterior cingulate cortices. Interindividual variability was largest in temporal and frontal regions across the lifespan. Age and its FP combinations explained up to 59% variance in cortical thickness. These results may form the basis of further investigation on normative deviation in cortical thickness and its significance for behavioral and cognitive outcomes.

Extensive mucocutaneous, oesophageal and otic lichen planus secondary to nivolumab therapy

We report a 73-year-old female with metastatic renal cell carcinoma who developed a widespread lichenoid reaction following nivolumab treatment. The timeline of the reaction strongly correlated with the nivolumab treatment and subsequent cessation. Our patient had cutaneous, mucosal, otic, ophthalmic and oesophageal involvement, demonstrating the potentially extensive nature of lichenoid reactions to anti-programmed cell death receptor-1 (anti-PD1) therapies. Although lichenoid reactions to anti-PD1 therapies are now well recognized, there have been no previous reports of otic or oesophageal involvement in the literature. Although cutaneous lichenoid reactions do not tend to be severe or treatment limiting, more widespread systemic lichenoid reactions are challenging to manage, particularly in the context of malignancy. This very unusual case highlights the importance of considering involvement beyond the skin in all lichenoid skin reactions.

Hong Kong Society of Clinical Blood Management recommendations for implementation of patient blood management

Patient blood management (PBM) is a patient-centred, multidisciplinary approach to optimise red cell mass, minimise blood loss, and manage tolerance to anaemia in an effort to improve patient outcomes. Well-implemented PBM improves patient outcomes and reduces demand for blood products. The multidisciplinary approach of PBM can often allow patients to avoid blood transfusions, which are associated with less favourable clinical outcomes. In Hong Kong, there has been increasing demand for blood in the ageing population, and there are simultaneous blood safety and donor issues that are adversely affecting the blood supply. To address these challenges, the Hong Kong Society of Clinical Blood Management recommends implementation of a PBM programme in Hong Kong, including strategies such as optimising red blood cell mass, improving anaemia management, minimising blood loss, and rationalising the use of blood and blood products.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Pain and gastrointestinal dysfunction are significant associations with psychiatric disorders in patients with Ehlers-Danlos syndrome and hypermobility spectrum disorders: a retrospective study

In this retrospective study, we investigate the frequency and types of psychiatric disorders and their relationship to systemic manifestations in a cohort of 391 Ehlers-Danlos syndromes (EDS) and hypermobility spectrum disorder (HSD) patients based on the current 2017 International Classification of EDS diagnostic criteria. A detailed, systematic retrospective chart review was undertaken for patients assessed for HSD or EDS at two Canadian health centres. Patients were diagnosed according to the Villefranche criteria and reclassified for this study according to the 2017 International Classification of EDS. Data validation and statistical analyses were conducted. Psychiatric disorders were very common, with 49.4% of the total cohort affected; 28.9% reported multiple psychiatric diagnoses. Mood (34.5%) and somatoform (28.6%) disorders were most common. Interestingly, attention-deficit/hyperactivity disorder (ADHD) was significantly enriched in the HSD, but not EDS cohort (p = 0.0002, 95% CI 3.48-9.00) compared to the general population. There were no differences in the systemic associations with having psychiatric manifestations in the HSD compared to the EDS subsets. Muscle/body pain (OR 1.99) and gastrointestinal dysfunction (OR 2.07) were significantly associated with having mood disorders, and gastrointestinal dysfunction (OR 2.61) and nerve-related pain (OR 3.27) were associated with having somatoform disorders across the cohort. The common systemic associations with the presence of psychiatric manifestations in both HSD and EDS reaffirm that the conditions should be treated as a spectrum rather than as wholly separate entities, particularly with respect to psychiatric management. EDS and HSD patients share common psychiatric presentations, though ADHD is more common with HSD.

Meningoencephalitis in a Royal Marine after skinning reindeer in Norway

Meningoencephalitis presenting in service personnel overseas may present a diagnostic challenge due to the broad range of potential differential diagnosis as well as the requirement for rapid assessment and treatment. A 25-year-old Royal Marine was evacuated to the Royal Centre for Defence Medicine in Birmingham, UK, with a history of rash consistent with erythema chronicum migrans, a seizure, and lymphocytic pleocytosis after skinning reindeer in Norway. Neuroborreliosis was suspected and empirical antibiotics were administered. Despite subsequent negative serology for Borrelia burgdorferi, given the clinical features and lymphocytic pleocytosis, an atypical presentation of neuroborreliosis remains a possible diagnosis in this scenario. This case serves to illustrate that British military personnel on exercise are potentially at risk of contracting borreliosis both in the UK and abroad, serological tests can be unreliable, and the differential diagnosis of meningoencephalitis can be broad with specialist input often required.

Mortality Risk Factors Among Patients With Cirrhosis and a Low Model for End-Stage Liver Disease Sodium Score (≤15): An Analysis of Liver Transplant Allocation Policy Using Aggregated Electronic Health Record Data

Although the Model for End-Stage Liver Disease sodium (MELD Na) score is now used for liver transplant allocation in the United States, mortality prediction may be underestimated by the score. Using aggregated electronic health record data from 7834 adult patients with cirrhosis, we determined whether the cause of cirrhosis or cirrhosis complications was associated with an increased risk of death among patients with a MELD Na score ≤15 and whether patients with the greatest risk of death could benefit from liver transplantation (LT). Over median follow-up of 2.3 years, 3715 patients had a maximum MELD Na score ≤15. Overall, 3.4% were waitlisted for LT. Severe hypoalbuminemia, hepatorenal syndrome, and hepatic hydrothorax conferred the greatest risk of death independent of MELD Na score with 1-year predicted mortality >14%. Approximately 10% possessed these risk factors. Of these high-risk patients, only 4% were waitlisted for LT, despite no difference in nonliver comorbidities between waitlisted patients and those not listed. In addition, risk factors for death among waitlisted patients were the same as those for patients not waitlisted, although the effect of malnutrition was significantly greater for waitlisted patients (hazard ratio 8.65 [95% CI 2.57-29.11] vs. 1.47 [95% CI 1.08-1.98]). Using the MELD Na score for allocation may continue to limit access to LT.

Insights into targeting young male drivers with anti-speeding advertising: An application of the Step approach to Message Design and Testing (SatMDT)

In Australia, young drivers aged 17-25 years comprise 13% of the population yet account for 22% of all road deaths with young males over-represented in such trauma. Speeding represents a major contributing factor and advertising campaigns have long focused on promoting anti-speeding messages in the effort to reduce drivers' speeds. Positioned within a larger program of research aimed at developing, piloting, and evaluating a range of theoretically-informed anti-speeding messages, the current study reports results relating to the final phase of the research, the evaluation. Six messages were devised in accordance with the guiding framework, the Step approach to Message Design and Testing ([SatMDT]; Lewis et al., 2016) and based on the findings emerging from earlier qualitative and quantitative studies within the program of research. N=938 licensed drivers (n=455 males, 48%) aged 17-62 years completed an online survey. To ensure a controlled test of the persuasiveness of the message content, the messages were presented in an audio-based format and thus were devoid of potential confounds, such as images. The messages sought to address a particular belief (i.e., behavioural, normative, control) and to focus either on emphasising the positive aspects which make speeding less likely or challenging the negative aspects which make speeding more likely. Thus, key to this evaluation was to test the persuasiveness of the message content in terms of the particular belief and focus it was addressing. Participants were randomly assigned to either the Control condition (i.e., no exposure to a message) or the Intervention condition (i.e., exposed to one of the six messages presented as an audio-recorded message within the survey). Persuasiveness was assessed via a range of outcome measures including both direct (i.e., third-person perceptions, message rejection) as well as indirect measures (i.e., intentions, willingness to speed). Age, gender, and message type were independent variables (IVs), together with issue involvement as a covariate (or IV) in the study's analyses. Overall, positive persuasive effects, and a relative absence of any negative, dissuasive effects, were found for two messages, Glass Cars and The Lift. These messages addressed the same salient belief, control beliefs, with the former emphasising the factors which discourage speeding and the latter message challenging those factors which encourage speeding. The implications of the findings are discussed in terms of the insights they offer for the key content of future anti-speeding messages.

Yeast recombinant Factor C from horseshoe crab binds endotoxin and causes bacteriostasis

Carcinoscorpius rotundicauda Factor C cDNA has been cloned and expressed in Pichia pastoris to produce a recombinant full-length Factor C (rFC) which is both immunoreactive and functional. The presence of a functional endotoxin-binding domain on rFC was ascertained by LPS-binding assays. One involved the relative binding affinity of rFC to electroblotted lipid A moiety of LPS. The second assay showed that rFC competed against native Factor C contained in C. rotundicauda amebocyte lysate (CAL) to bind LPS. Purification of rFC enhanced its binding affinity to LPS. By agglutination, rFC caused bacteriostasis of Gram-negative bacteria within 2 h. In an in vivo system, rFC also decreased the mortality of actinomycin D-sensitized/LPS-challenged mice. The rFCEE, bearing the 5' terminal LPS binding domain displayed a lowered affinity for LPS. This is in contrast to the rFCSN subclone that is devoid of the 5' end of Factor C, and which does not bind LPS. The presence of a fully-functional endotoxin binding domain in rFC probably requires a full-length protein for co-operative interaction of its downstream sequences. Thus, rFC has potential in the detection and removal of contaminating LPS from biological specimens and fluids for injection, since it is capable of binding both free and bound lipid A.

Expression of full length and deletion homologues of Carcinoscorpius rotundicauda Factor C in Saccharomyces cerevisiae: immunoreactivity and endotoxin binding

Deletion homologues of the cloned Factor C cDNAs from the horseshoe crab Carcinoscorpius rotundicauda were engineered to express in Saccharomyces cerevisiae under the regulation of a galactose-inducible promoter. Expression cassettes were constructed in the vectors: pEMBLyex4 and YEpsec1 to direct, respectively, the intracellular expression, and the secretion of the protein into the culture medium using a heterologous signal sequence. The effect of insert size on the efficiency of expression and the functionality of the resulting recombinant Factor C (rFC) were studied by creating expression constructs bearing various deletion and/or hybrid fragments of Factor C. Removal of the long 5' UTR from the Factor C cDNA improved expression of the rFC. 3' Deletions of up to 84%, or internal deletions of 65% of the Factor C cDNA resulted in either the lack of detectable amounts of Factor C or loss of immunoreactivity. Depending on the construct, full length or partial rFC-related proteins were correspondingly expressed intracellularly, regardless of the vector. The rFC partitioned with the insoluble cell fraction, was solubilised with either SDS or Triton X-100, and found to be immunoreactive. The rFCs were functionally active, being able to bind Gram-negative bacterial endotoxin, provided critical regions of the endotoxin-binding domain were preserved.

Proposed mechanism of antibacterial action of chemically modified apatite for reduced bone infection

Surface-bound silver ions were demonstrated to be responsible for the antibacterial action of silver, silicon-containing hydroxyapatite (Ag,Si-HA). X-ray photoelectron spectroscopy, transmission electron microscopy, and induced coupled plasma spectroscopy results suggested that silver ions in the crystal structure diffused toward the crystal surface of Ag,Si-HA, and interacted with adherent Staphylococcus aureus bacteria, thus damaging the cell wall and inducing leakage of potassium ions. All these steps constitute the mechanism of antibacterial action for Ag,Si-HA. Consequently, Ag,Si-HA gave rise to a 7-log reduction of the adherent bacteria as compared to HA and Si-HA at 168 h. Silicon in Ag,Si-HA helped to mitigate the reduced effect of bone differentiation in Ag-HA as shown in the alkaline phosphatase, type I collagen and osteocalcin results, promoting enhanced biological response, without compromising the antibacterial property. On the whole, Ag,Si-HA containing an optimized content of 0.5 wt % silver and 0.7 wt % silicon provides antibacterial properties and enhanced biological response.

Zinc-substituted hydroxyapatite: a biomaterial with enhanced bioactivity and antibacterial properties

Hydroxyapatite (HA) is a synthetic biomaterial and has been found to promote new bone formation when implanted in a bone defect site. However, its use is often limited due to its slow osteointegration rate and low antibacterial activity, particularly where HA has to be used for long term biomedical applications. This work will describe the synthesis and detailed characterization of zinc-substituted HA (ZnHA) as an alternative biomaterial to HA. ZnHA containing 1.6 wt% Zn was synthesized via a co-precipitation reaction between calcium hydroxide, orthophosphoric acid and zinc nitrate hexahydrate. Single-phase ZnHA particles with a rod-like morphology measuring ~50 nm in length and ~15 nm in width, were obtained and characterized using transmission electron microscopy and X-ray diffraction. The substitution of Zn into HA resulted in a decrease in both the a- and c-axes of the unit cell parameters, thereby causing the HA crystal structure to alter. In vitro cell culture work showed that ZnHA possessed enhanced bioactivity since an increase in the growth of human adipose-derived mesenchymal stem cells along with the bone cell differentiation markers, were observed. In addition, antibacterial work demonstrated that ZnHA exhibited antimicrobial capability since there was a significant decrease in the number of viable Staphylococcus aureus bacteria after in contact with ZnHA.

Tooth Agenesis Association with Self-reported Family History of Cancer

It has been proposed that tooth agenesis and cancer development share common molecular pathways. We performed a cross-sectional study to investigate the epidemiological and molecular association between tooth agenesis and self-reported family history of cancer. Eighty-two individuals with tooth agenesis and 328 individuals with no birth defect were recruited from the same institution. Tooth agenesis was assessed in permanent teeth and was defined based on the age of the participants and when initial tooth formation should be radiographically visible. We also investigated the role of genes involved in dental development that have been implicated in tumorigenesis, and 14 markers in AXIN2, FGF3, FGF10, and FGFR2 were genotyped. Individuals with tooth agenesis had an increased risk of having a family history of cancer ( p = 0.00006; OR = 2.7; 95% C.I., 1.6-4.4). There were associations between AXIN2, FGF3, FGF10, and FGFR2 with tooth agenesis [ i.e., individuals who carried the polymorphic allele of FGFR2 (rs1219648) presented higher risk for having premolar agenesis ( p = 0.02; OR = 1.8; 95% C.I., 1.1-3.0)]. In conclusion, tooth agenesis was associated with positive self-reported family history of cancer and with variants in AXIN2, FGF3, FGF10, and FGFR2. Prospective studies are needed to confirm if tooth agenesis can be used as a risk marker for cancer.

Outcomes and native renal recovery following simultaneous liver-kidney transplantation

With the increase in patients having impaired renal function at liver transplant due to MELD, accurate predictors of posttransplant native renal recovery are needed to select candidates for simultaneous liver-kidney transplantation (SLK). Current UNOS guidelines rely on specific clinical criteria for SLK allocation. To examine these guidelines and other variables predicting nonrecovery, we analyzed 155 SLK recipients, focusing on a subset (n = 78) that had post-SLK native GFR (nGFR) determined by radionuclide renal scans. The 77 patients not having renal scans received a higher number of extended criteria donor organs and had worse posttransplant survival. Of the 78 renal scan patients, 31 met and 47 did not meet pre-SLK UNOS criteria. The UNOS criteria were more predictive than our institutional criteria for all nGFR recovery thresholds (20-40 mL/min), although at the most conservative cut-off (nGFR ≤ 20) it had low sensitivity (55.3%), specificity (75%), PPV (67.6%) and NPV (63.8%) for predicting post-SLK nonrecovery. On multivariate analysis, the only predictor of native renal nonrecovery (nGFR ≤ 20) was abnormal pre-SLK renal imaging (OR 3.85, CI 1.22-12.5). Our data support the need to refine SLK selection utilizing more definitive biomarkers and predictors of native renal recovery than current clinical criteria.

Incidence, diagnosis, and outcomes of vocal fold immobility after esophageal atresia (EA) and/or tracheoesophageal fistula (TEF) repair

BACKGROUND

The diagnosis of vocal fold paralysis in an infant is a devastating finding that may require a permanent tracheotomy. The incidence of congenital vocal fold paralysis is unknown, but it is thought to be more common in infants with anatomic anomalies in the aero-digestive system. Vocal fold paralysis after surgical repair of esophageal atresia and tracheoesophageal fistula is a rare finding often diagnosed after multiple failed extubations. Currently infants do not routinely undergo documentation of vocal fold motion prior to esophageal atresia repair. We report here on our experience with this rare complication.

METHOD

A retrospective review was done of patients with esophageal atresia and/or tracheoesophageal fistula from 1985 to 2009. Patient demographics, operative techniques, and outcomes were collected.

RESULTS

150 patients were identified. Mean age at surgical intervention was 12 ± 33 days. Otolaryngology service was consulted for 13% of patients with postoperative failure. Awake fiberoptic laryngoscopy identified 3% of patients with vocal fold paralysis. Bilateral vocal fold paralysis was found in 3 patients, and 2 patients had unilateral vocal fold paralysis. Patients with bilateral paralysis were treated with tracheotomy; unilateral paralysis was treated expectantly.

CONCLUSION

In this study, 3% of patients were diagnosed with vocal fold paralysis after esophageal atresia repair. The etiology of vocal fold paralysis in this study is difficult to assess. Pre-operative fiberoptic laryngoscopy is recommended to identify children with congenital vocal fold paralysis prior to surgical intervention, especially in those requiring revision surgery.

Thermal Treatments Modulate Bacterial Adhesion to Dental Enamel

Numerous studies have demonstrated the effects of laser-induced heat on demineralization of enamel; however, no studies have investigated the link between heat/laser-induced changes in physicochemical properties and bacterial adhesion. In this study, we investigated the effects of thermal treatment on surface properties of enamel such as hydrophobicity and zeta potential. Bacterial adhesion to treated surfaces was characterized by confocal laser scanning microscopy, and adhesion force was quantified by atomic force microscopy. The hydrophobicity of enamel increased after heating (p < 0.05), and the zeta potential of heated enamel became more negative than that of the control (p < 0.01). Streptococcus oralis and S. mitis were more hydrophilic than S. sanguis, with more negative zeta potential (all p < 0.01). S. mitis and S. oralis occupied significantly less area on enamel after being heated (p < 0.05). Heating reduced the adhesion force of both S. mitis and S. oralis to enamel with or without saliva coating. Reduction of adhesion force was statistically significant for S. mitis (p < 0.01), whereas that of S. oralis was not statistically significant (p > 0.05). Heating did not affect the adhesion of S. sanguis with or without saliva coating. In conclusion, thermal treatment and photothermal/laser treatments may modulate the physicochemical properties of enamel, preventing the adhesion of some bacterial species.

Antipsychotic dose and diminished neural modulation: a multi-site fMRI study

BACKGROUND

The effect of antipsychotics on the blood oxygen level dependent signal in schizophrenia is poorly understood. The purpose of the present investigation is to examine the effect of antipsychotic medication on independent neural networks during a motor task in a large, multi-site functional magnetic resonance imaging investigation.

METHODS

Seventy-nine medicated patients with schizophrenia and 114 comparison subjects from the Mind Clinical Imaging Consortium database completed a paced, auditory motor task during functional magnetic resonance imaging (fMRI). Independent component analysis identified temporally cohesive but spatially distributed neural networks. The independent component analysis time course was regressed with a model time course of the experimental design. The resulting beta weights were evaluated for group comparisons and correlations with chlorpromazine equivalents.

RESULTS

Group differences between patients and comparison subjects were evident in the cortical and subcortical motor networks, default mode networks, and attentional networks. The chlorpromazine equivalents correlated with the unimotor/bitemporal (rho=-0.32, P=0.0039), motor/caudate (rho=-0.22, P=0.046), posterior default mode (rho=0.26, P=0.020), and anterior default mode networks (rho=0.24, P=0.03). Patients on typical antipsychotics also had less positive modulation of the motor/caudate network relative to patients on atypical antipsychotics (t(77)=2.01, P=0.048).

CONCLUSION

The results suggest that antipsychotic dose diminishes neural activation in motor (cortical and subcortical) and default mode networks in patients with schizophrenia. The higher potency, typical antipsychotics also diminish positive modulation in subcortical motor networks. Antipsychotics may be a potential confound limiting interpretation of fMRI studies on the disease process in medicated patients with schizophrenia.

Bowel obstruction after treatment of intra-abdominal tumors

BACKGROUND

Tumors of the solid viscera are one of the most common types of pediatric malignancies. Due to the intra-abdominal location of many of these neoplasms, laparotomy and/or bowel resection are often necessary, predisposing patients to postoperative intestinal obstruction. Additionally, chemotherapy and radiation therapy may lead to acute and chronic bowel injury, also potentially predisposing these patients to postoperative bowel obstruction. We reviewed our data over an eleven-year period to identify the incidence of obstruction as well as factors associated with its development.

METHODS

A retrospective data analysis of all patients diagnosed with intra-abdominal Wilms' tumor, rhabdomyosarcoma, neuroblastoma, and Hodgkin's and non-Hodgkin's lymphoma in a single institution from 1997 to 2007 was conducted. Data collected included demographic factors, operations, incidence of small bowel obstruction (SBO) and the use of adjuvant or neoadjuvant chemoradiation therapy. Patients who developed SBO were compared to those who did not develop obstruction. Data comparisons were analyzed statistically using Fisher's exact test, 2-tailed Student's t-Test, or chi-square proportional analysis with significance reported for p<0.05.

RESULTS

A total of 291 patients were identified during the study period. Mean age at diagnosis was 8.1+/-5.8 years. Males accounted for 57% of all patients. Tumor distribution was as follows: Wilms' tumor: 56 (19%); non-Hodgkin's lymphoma: 71 (24%); Hodgkin's lymphoma: 64 (22%); rhabdomyosarcoma: 32 (11%); and neuroblastoma: 68 (24%). There were a total of 12 bowel obstructions in 11 patients (3.7%). Mean follow-up for all patients was 3.6+/-2.7 years. Children with bowel obstruction were more likely to be male (4.5:1, p=0.061) and younger (4.2 years versus 8.1 years; p=0.087). Wilms' tumor accounted for 45% of patients with bowel obstruction, but made up only 19% of the study population. The incidence of bowel obstruction in patients with Wilms' tumor was 8.9% compared to an overall incidence of 3.8% (p=0.043).

CONCLUSION

Bowel obstruction is relatively uncommon after intra-abdominal malignancies in children. Wilms' tumor, rhabdomyosarcoma and Burkitt's lymphoma appear to be associated with the highest risk of bowel obstruction.

Overexpression of the orphan receptor Nur77 alters glucose metabolism in rat muscle cells and rat muscle in vivo

AIMS/HYPOTHESIS

A hallmark feature of the metabolic syndrome is abnormal glucose metabolism which can be improved by exercise. Recently the orphan nuclear receptor subfamily 4, group A, member 1 (NUR77) was found to be induced by exercise in muscle and was linked to transcriptional control of genes involved in lipid and glucose metabolism. Here we investigated if overexpression of Nur77 (also known as Nr4a1) in skeletal muscle has functional consequences for lipid and/or glucose metabolism.

METHODS

L6 rat skeletal muscle myotubes were infected with a Nur77-coding adenovirus and lipid and glucose oxidation was measured. Nur77 was also overexpressed in skeletal muscle of chow- and fat-fed rats and the effects on glucose and lipid metabolism evaluated.

RESULTS

Nur77 overexpression had no effect on lipid oxidation in L6 cells or rat muscle, but did increase glucose oxidation and glycogen synthesis in L6 cells. In chow- and high-fat-fed rats, Nur77 overexpression by electrotransfer significantly increased basal glucose uptake and glycogen synthesis, but no increase in insulin-stimulated glucose metabolism was observed. Nur77 electrotransfer was associated with increased production of GLUT4 and glycogenin and increased hexokinase and phosphofructokinase activity. Interestingly, Nur77 expression in muscle biopsies from obese men was significantly lower than in those from lean men and was closely correlated with body-fat content and insulin sensitivity.

CONCLUSIONS/INTERPRETATION

Our data provide compelling evidence that NUR77 is a functional regulator of glucose metabolism in skeletal muscle in vivo. Importantly, the diminished content in muscle of obese insulin-resistant men suggests that it might be a potential therapeutic target for the treatment of dysregulated glucose metabolism.

Perception versus reality?: Virtual crossmatch--how to overcome some of the technical and logistic limitations

The goal of this work was to evaluate concordance between (a) actual flow cytometric crossmatch (FCXM) that is performed by the OPO laboratory servicing our transplant center and (b) virtual XM (vXM) prediction based on antibody identification by solid-phase methods performed in our laboratory. A total of 1586 FCXM, performed between June 2007 and September 2008, between all potential deceased donors in our region and sera from patients awaiting kidney or kidney-pancreas transplant, listed at Northwestern Memorial Hospital were evaluated. A key finding of this analysis was the understanding that a thorough vXM cannot be performed in some donor/recipient pairs due to the lack of certain antibody profile data specific to the donor in question. Obtaining more in depth and stringent information regarding antibody specificities, we demonstrate an excellent sensitivity and specificity of the vXM assays- 86.1% and 96.8%, respectively, with a positive likelihood ratio and negative likelihood ratios of 26.9 and 0.14, respectively. The vXM can serve as an outstanding tool to predict HLA compatibility between donor and recipient, with the caveat that the presence/absence of all antibodies against the potential donor and their strength have been thoroughly investigated.

Single-stranded DNA oligoaptamers: molecular recognition and LPS antagonism are length- and secondary structure-dependent

In Gram-negative bacterial infection, lipopolysaccharide (LPS) readily overwhelms the host innate immune system, which could result in inflammation and sepsis in severe cases. Therefore, developing anti-LPS molecules would confer an efficient antibacterial strategy. We used SELEX (Systemic Evolution of Ligands by EXponential enrichment) to isolate single-stranded DNA (ssDNA) aptamers. By immobilizing and exposing different orientations of the LPS molecule on hydrophobic and hydrophilic surfaces, two populations of aptamers were captured from a library of 10(14-15) ssDNA oligonucleotides. Progressive SELEX enriched the aptamers towards thymidine residues. The more hydrophobic aptamers with T-rich loops showed strong molecular recognition for the lipid A moiety of LPS, binding at affinity of up to K(D) of 10(-9)M, and eliciting 95% neutralization of endotoxicity. The longer ssDNAs exhibited greater avidity for LPS and conferred more efficacious antagonism against LPS. The nucleotide composition imposes subtle influence on the aptamer folding and affinity for LPS.

Rituximab failed to improve nephrotic syndrome in renal transplant patients with recurrent focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) recurs in 30% of patients with FSGS receiving a first renal transplant and in over 80% of patients receiving a second transplant after a recurrence. Recurrence often leads to graft failure. The pathogenesis remains unknown and may involve a circulating permeability factor that initiates injury to the glomerular capillary. There are anecdotal reports of pediatric patients with posttransplant lymphoproliferative disorder (PTLD) and recurrent FSGS who have had remission of proteinuria after treatment with rituximab. These observations have prompted speculation that B cells may play a role in the pathogenesis of recurrent FSGS. We report four consecutive adult patients with early recurrent FSGS refractory or dependent on plasmapheresis who received rituximab (total dose 2000-4200 mg). None of the patients treated with rituximab achieved remission in proteinuria, and one patient experienced early graft loss. In these four adult renal transplant patients with recurrent FSGS, rituximab failed to diminish proteinuria.

Atomic force microscopy study of the antimicrobial action of Sushi peptides on Gram negative bacteria

The antibacterial effect of the endotoxin-binding Sushi peptides against Gram-negative bacteria (GNB) is investigated in this study. Similar characteristics observed for Atomic force microscopy (AFM) images of peptide-treated Escherichia coli and Pseudomonas aeruginosa suggest that the Sushi peptides (S3) evoke comparable mechanism of action against different strains of GNB. The results also indicate that the Sushi peptides appear to act in three stages: damage of the bacterial outer membrane, permeabilization of the inner membrane and disintegration of both membranes. The AFM approach has provided vivid and detailed close-up images of the GNB undergoing various stages of antimicrobial peptide actions at the nanometer scale. The AFM results support our hypothesis that the S3 peptide perturbs the GNB membrane via the "carpet-model" and thus, provide important insights into their antimicrobial mechanisms.

Endotoxin Levels in Rural Thai and Urban Singaporean Homes

BACKGROUND

Exposure to dust endotoxin and allergens in early childhood may influence the development of allergic diseases.

AIMS

This study aimed to evaluate dust endotoxin and dust mite allergens in urban Singapore and rural Thai homes of young children and study potential environmental influences.

METHODS

Mattress dust endotoxin and Der p 1, Der f 1, group 2 (Der f 2 and Der p 2) and Blo t 5 allergen levels were quantified in 101 infant mattress dust samples, 51 from urban Singapore and 50 from rural Thailand. Comprehensive questionnaires on the home environment and cleaning practices were completed.

RESULTS

Endotoxin levels in rural Thailand were significantly higher than in urban Singapore (geometric mean 26,334.12 +/- 4.60 and 18,377.85 +/- 2.52 endotoxin units/g, respectively; p = 0.032). In contrast, higher levels of Der f 1 (p = 0.02), group 2 (p < 0.01) and Blo t 5 (p < 0.01) allergens were found in Singapore homes compared with rural Thai homes. Multiple logistic regression analysis showed that the use of detergents (p = 0.001) and disinfectants (p = 0.024) to clean floors and mattress protectors (p = 0.021) were independently associated with lower endotoxin levels.

CONCLUSION

Endotoxin levels are higher in rural compared with urban homes in South East Asia. The reverse was true for dust mite allergen levels. Certain identifiable home environmental conditions and practices accounted for the differences in endotoxin levels.

The specificity of Sushi peptides for endotoxin and anionic phospholipids: potential application of POPG as an adjuvant for anti-LPS strategies

Sushi peptides [S1 (Sushi 1 peptide) and S3] are derived from the LPS (lipopolysaccharide; also known as endotoxin)-binding domains of an LPS-sensitive serine protease, Factor C, from the horseshoe crab (Carcinoscorpius rotundicauda). S1 and S3 interact at high affinity with LPS. The intermolecular disulphide bonding in the S3 dimer is indispensable for its LPS binding, disruption and consequent neutralization. Simultaneously, the specific interaction between the Sushi peptides and bacterial membrane phospholipids further explains the selective propensity of these peptides for the gram-negative bacteria. Our findings yield insights into a complex molecular paradigm in which the juxtaposition of LPS molecules and the anionic phospholipid POPG (1-palmitoyl-2-oleoyl phosphatidylglycerol) on the bacterial outer membrane confers such interfacial properties which create the optimal environment for the interaction between the peptides and bacterial membrane lipids.

Spatial and temporal coordination of expression of immune response genes during Pseudomonas infection of horseshoe crab, Carcinoscorpius rotundicauda

Knowledge on how genes are turned on/off during infection and immunity is lacking. Here, we report the co-regulation of diverse clusters of functionally related immune response genes in a horseshoe crab, Carcinoscorpius rotundicauda. Expressed sequence tag (EST) clusters for frontline immune defense, cell signalling, apoptosis and stress response genes were expressed or repressed spatio-temporally during the acute phase of Pseudomonas infection. An infection time course monitored by virtual Northern evaluation indicates upregulation of genes in blood cells (amebocytes) at 3-h postinfection, whereas most of the hepatopancreas genes remained down regulated over 72 h of infection. Thus, the two tissues orchestrate a coordinated and timely response to infection. The hepatopancreas probably immuno-modulates the expression of other genes and serves as a reservoir for later response, if/when chronic infection ensues. On the other hand, being the first to encounter pathogens, we reasoned that amebocytes would respond acutely to infection. Besides acute transactivation of the immune genes, the amebocytes maintained morphological integrity, indicating their ability to synthesise and store/secrete the immune proteins and effectors to sustain the frontline innate immune defense, while simultaneously elicit complement-mediated phagocytosis of the invading pathogen. Our results show that the immune response against Pseudomonas infection is spatially and temporally coordinated.

De novo design of potent antimicrobial peptides

Lipopolysaccharide (LPS), shed by gram-negative bacteria during infection and antimicrobial therapy, may lead to lethal endotoxic shock syndrome. A rational design strategy based on the presumed mechanism of antibacterial effect was adopted to design cationic antimicrobial peptides capable of binding to LPS through tandemly repeated sequences of alternating cationic and nonpolar residues. The peptides were designed to achieve enhanced antimicrobial potency due to initial bacterial membrane binding with a reduced risk of endotoxic shock. The peptides designed displayed binding affinities to LPS and lipid A (LA) in the low micromolar range and by molecular modeling were predicted to form amphipathic beta-hairpin-like structures when they bind to LPS or LA. They also exhibited strong effects against gram-negative bacteria, with MICs in the nanomolar range, and low cytotoxic and hemolytic activities at concentrations significantly exceeding their MICs. Quantitative structure-activity relationship (QSAR) analysis of peptide sequences and their antimicrobial, cytotoxic, and hemolytic activities revealed that site-directed substitutions of residues in the hydrophobic face of the amphipathic peptides with less lipophilic residues selectively decrease the hemolytic effect without significantly affecting the antimicrobial or cytotoxic activity. On the other hand, the antimicrobial effect can be enhanced by substitutions in the polar face with more polar residues, which increase the amphipathicity of the peptide. On the basis of the QSARs, new analogs that have strong antimicrobial effects but that lack hemolytic activity can be proposed. The findings highlight the importance of peptide amphipathicity and allow a rational method that can be used to dissociate the antimicrobial and hemolytic effects of cationic peptides, which have potent antimicrobial properties, to be proposed.

Effectiveness ofCyanothece spp. andCyanospira capsulata exocellular polysaccharides as antiadhesive agents for blocking attachment ofHelicobacter pylori to human gastric cells

The effect of cyanobacterial polysaccharides (from Cyanothece spp. and Cyanospira capsulata) on the binding of Helicobacter pylori to gastric epithelial cells was evaluated. The antiadhesive action on Kato III and HeLa S3 human gastric cell lines was established.