Molecular basis of differential HLA class I-restricted T cell recognition of a highly networked HIV peptide

Cytotoxic-T-lymphocyte (CTL) mediated control of HIV-1 is enhanced by targeting highly networked epitopes in complex with human-leukocyte-antigen-class-I (HLA-I). However, the extent to which the presenting HLA allele contributes to this process is unknown. Here we examine the CTL response to QW9, a highly networked epitope presented by the disease-protective HLA-B57 and disease-neutral HLA-B53. Despite robust targeting of QW9 in persons expressing either allele, T cell receptor (TCR) cross-recognition of the naturally occurring variant QW9_S3T is consistently reduced when presented by HLA-B53 but not by HLA-B57. Crystal structures show substantial conformational changes from QW9-HLA to QW9_S3T-HLA by both alleles. The TCR-QW9-B53 ternary complex structure manifests how the QW9-B53 can elicit effective CTLs and suggests sterically hindered cross-recognition by QW9_S3T-B53. We observe populations of cross-reactive TCRs for B57, but not B53 and also find greater peptide-HLA stability for B57 in comparison to B53. These data demonstrate differential impacts of HLAs on TCR cross-recognition and antigen presentation of a naturally arising variant, with important implications for vaccine design.

Early onset of age-related changes in the retina of cystine/glutamate antiporter knockout mice

To determine the role of the cystine/glutamate antiporter on retinal structure and function, retinas of C57Bl/6J wild-type and xCT knockout mice, lacking the xCT subunit of the cystine/glutamate antiporter were examined from 6 weeks to 12 months of age. Fundoscopy, optical coherence tomography (OCT), and whole mount retinal autofluorescence imaging were used to visualise age-related retinal spots. Glial fibrillary acidic protein (GFAP) immunolabelling was used to assess retinal stress. Retinal function was evaluated using full-field and focal electroretinograms. Examinations revealed retinal spots in both wild-type and xCT knockout mice with the number of spots greater at 9 months in the knockout compared to wild-type. OCT confirmed these discrete spots were located at the retinal pigment epithelium (RPE)-photoreceptor junction and did not label with drusen markers. Whole mount lambda scans of the 9 month xCT knockout retinas revealed that the photoreceptor autofluorescence matched the spots, suggesting these spots were retinal debris. GFAP labelling was increased in knockout retinas compared to wild-type indicative of retinal stress, and the discrete spots were associated with migration of microglia/macrophages to the RPE-retina intersection. OCT revealed that the superior retina was thinner at 9 months in knockout compared to wild-type mice due to changes to the outer nuclear and photoreceptor layers. While global retinal function was not affected by loss of xCT, focal changes in retinal function were detected in areas where spots were present. Tother these results suggest that the xCT KO mice exhibit features of accelerated ageing and suggests that this mouse model may be useful for studying the underlying cellular pathways in retinal ageing.

A multi-site study on the impact of an advance care planning workshop on attitudes, beliefs and behavioural intentions over a 6-month period

BACKGROUND

This study evaluated the impact of the adapted version of the Respecting Choices® The Living Matters Advance Care Planning (ACP) facilitator training programme on trainees' attitudes on facilitation 6 months post-training.

SETTING AND PARTICIPANTS

Two hundred and twenty-one healthcare professionals consisting of doctors, nurses, medical social workers from different training venues in Singapore participated in the first phase of the study (pre- and post) of which 107 participated in the second phase 6 months later (follow-up).

METHODS

Participants self-rated their attitudes, beliefs and behavioural intentions through surveys at three time points in an evaluation design that utilised repeated measures one-way ANOVA (pre-, post-, follow-up). Between-group differences were also examined using independent t-test.

RESULTS

At follow-up, mean scores increased significantly in understanding, confidence, and competence. Changes in effect sizes were large. Although trainees continued to think that ACP is emotionally draining for facilitators, more than before, facilitation experience was considered pleasant for themselves with the positive change significant and moderate in effect size. Those who had experience completing/initiating ACP significantly held more positive views than those who did not.

CONCLUSIONS

The ACP facilitator training programme had lasting effects on enhancing the understanding, competence, and confidence of trainees. Importantly, findings showed that experience in actual facilitation within 6 months after training was important and giving trainees opportunities to facilitate is recommended.

Efficacy and safety of disinfectants for decontamination of N95 and SN95 filtering facepiece respirators: a systematic review

BACKGROUND

Decontaminating and reusing filtering facepiece respirators (FFRs) for healthcare workers is a potential solution to address inadequate FFR supply during a global pandemic.

AIM

The objective of this review was to synthesize existing data on the effectiveness and safety of using chemical disinfectants to decontaminate N95 FFRs.

METHODS

A systematic review was conducted on disinfectants to decontaminate N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO feed, and MedRxiv. Two reviewers independently determined study eligibility and extracted predefined data fields. Original research reporting on N95 FFR function, decontamination, safety, or FFR fit following decontamination with a disinfectant was included.

FINDINGS AND CONCLUSION

A single cycle of vaporized hydrogen peroxide (H₂O₂) successfully removes viral pathogens without affecting airflow resistance or fit, and maintains an initial filter penetration of <5%, with little change in FFR appearance. Residual hydrogen peroxide levels following decontamination were within safe limits. More than one decontamination cycle of vaporized H₂O₂ may be possible but further information is required on how multiple cycles would affect FFR fit in a real-world setting before the upper limit can be established. Although immersion in liquid H₂O₂ does not appear to adversely affect FFR function, there is no available data on its ability to remove infectious pathogens from FFRs or its impact on FFR fit. Sodium hypochlorite, ethanol, isopropyl alcohol, and ethylene oxide are not recommended due to safety concerns or negative effects on FFR function.

Decontaminating N95 and SN95 masks with ultraviolet germicidal irradiation does not impair mask efficacy and safety

Inadequate supply of filtering facepiece respirators (FFRs) for healthcare workers during a pandemic such as the novel coronavirus outbreak (SARS-CoV-2) is a serious public health issue. The aim of this study was to synthesize existing data on the effectiveness of ultraviolet germicidal irradiation (UVGI) for N95 FFR decontamination. A systematic review (PROSPERO CRD42020176156) was conducted on UVGI in N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO feed, and MedRxiv. Two reviewers independently determined eligibility and extracted predefined variables. Original research reporting on function, decontamination, or mask fit following UVGI were included. Thirteen studies were identified, comprising 54 UVGI intervention arms and 58 N95 models. FFRs consistently maintained certification standards following UVGI. Aerosol penetration averaged 1.19% (0.70-2.48%) and 1.14% (0.57-2.63%) for control and UVGI arms, respectively. Airflow resistance for the control arms averaged 9.79 mm H₂O (7.97-11.70 mm H₂O) vs 9.85 mm H₂O (8.33-11.44 mm H₂O) for UVGI arms. UVGI protocols employing a cumulative dose >20,000 J/m² resulted in a 2-log reduction in viral load. A >3-log reduction was observed in seven UVGI arms using >40,000 J/m². Impact of UVGI on fit was evaluated in two studies (16,200; 32,400 J/m²) and no evidence of compromise was found. Our findings suggest that further work in this area (or translation to a clinical setting) should use a cumulative UV-C dose of 40,000 J/m² or greater, and confirm appropriate mask fit following decontamination.

Decontaminating N95 and SN95 masks with ultraviolet germicidal irradiation does not impair mask efficacy and safety

Inadequate supply of filtering facepiece respirators (FFRs) for healthcare workers during a pandemic such as the novel coronavirus outbreak (SARS-CoV-2) is a serious public health issue. The aim of this study was to synthesize existing data on the effectiveness of ultraviolet germicidal irradiation (UVGI) for N95 FFR decontamination. A systematic review (PROSPERO CRD42020176156) was conducted on UVGI in N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO feed, and MedRxiv. Two reviewers independently determined eligibility and extracted predefined variables. Original research reporting on function, decontamination, or mask fit following UVGI were included. Thirteen studies were identified, comprising 54 UVGI intervention arms and 58 N95 models. FFRs consistently maintained certification standards following UVGI. Aerosol penetration averaged 1.19% (0.70-2.48%) and 1.14% (0.57-2.63%) for control and UVGI arms, respectively. Airflow resistance for the control arms averaged 9.79 mm H₂O (7.97-11.70 mm H₂O) vs 9.85 mm H₂O (8.33-11.44 mm H₂O) for UVGI arms. UVGI protocols employing a cumulative dose >20,000 J/m² resulted in a 2-log reduction in viral load. A >3-log reduction was observed in seven UVGI arms using >40,000 J/m². Impact of UVGI on fit was evaluated in two studies (16,200; 32,400 J/m²) and no evidence of compromise was found. Our findings suggest that further work in this area (or translation to a clinical setting) should use a cumulative UV-C dose of 40,000 J/m² or greater, and confirm appropriate mask fit following decontamination.

Medical conditions and driving fitness of older Singaporean taxi drivers

BACKGROUND

Taxi driving has been associated with the risk of various diseases (e.g. cardiovascular disease, hypertension, diabetes, hyperlipaemia, back pain). Little is known about the relationship between health conditions and driving fitness of older taxi drivers who continue to work.

AIMS

To investigate the (i) prevalence of medical conditions and (ii) relationship between age and medical conditions, with on-road driving tests in the relicensing process of older taxi drivers aged ≥70 years, prior to the mandatory retirement age of 75 years.

METHODS

We analysed retrospectively all relicensing records (N = 855) of taxi drivers aged 70, 73 and 74 years that were submitted from April 2014 to April 2015.

RESULTS

All passed their medical fitness screening. Ninety-eight per cent passed their driving tests. Thirty-one per cent, 36% and 24% reported none, one and two medical conditions, respectively. These included hypertension (56%), eye disease (25%; cataracts 19%), diabetes (24%), corrected hearing impairment (14%), hyperlipaemia (12%) and heart disease (9%). Deafness (P < 0.001) was associated with older age. No past medical condition affected driving outcome.

CONCLUSION

Older Singaporean taxi drivers were healthy and generally competent drivers. Early effective preventive health screening and modifiable lifestyle intervention are recommended in older taxi drivers.

The predictors and economic burden of early-, mid- and late-onset cardiac implantable electronic device infections: a retrospective cohort study in Ontario, Canada

The rate of cardiac implantable electronic device (CIED) infection is increasing with time. We sought to determine the predictors, relative mortality, and cost burden of early-, mid- and late-onset CIED infections. We conducted a retrospective cohort study of all CIED implantations in Ontario, Canada between April 2013 and March 2016. The procedures and infections were identified in validated, population-wide health-care databases. Infection onset was categorized as early (0-30 days), mid (31-182 days) and late (183-365 days). Cox proportional hazards regression was used to assess the mortality impact of CIED infections, with infection modelled as a time-varying covariate. A generalized linear model with a log-link and γ distribution was used to compare health-care system costs by infection status. Among 17 584 patients undergoing CIED implantation, 215 (1.2%) developed an infection, including 88 early, 85 mid, and 42 late infections. The adjusted hazard ratio (aHR) of death was higher for patients with early (aHR 2.9, 95% CI 1.7-4.9), mid (aHR 3.3, 95% CI 1.9-5.7) and late (aHR 19.9, 95% CI 9.9-40.2) infections. Total mean 1-year health costs were highest for late-onset (mean Can$113 778), followed by mid-onset (mean Can$85 302), and then early-onset (Can$75 415) infections; costs for uninfected patients were Can$25 631. After accounting for patient and procedure characteristics, there was a significant increase in costs associated with early- (rate ratio (RR) 3.1, 95% CI 2.3-4.1), mid- (RR 2.8, 95% CI 2.4-3.3) and late- (RR 4.7, 95% CI 3.6-6.2) onset infections. In summary, CIED infections carry a tremendous clinical and economic burden, and this burden is disproportionately high for late-onset infections.

Low medical morbidity and mortality after acute courses of electroconvulsive therapy in a population-based sample

BACKGROUND

To determine event rates for specific medical events and mortality among individuals receiving electroconvulsive therapy (ECT).

METHOD

Population-based cohort study using health administrative data of acute ECT treatments delivered in Ontario, Canada, from 2003 to 2011. We measured the following medical event rates, per 10 000 ECT treatments, up to 7 and 30 days post-treatment: stroke, seizure, acute myocardial infarction, arrhythmia, pneumonia, pulmonary embolus, deep vein thrombosis, gastrointestinal bleeding, falls, hip fracture, and mortality.

RESULTS

A total of 135 831 ECT treatments were delivered to 8810 unique patients. Overall medical event rates were 9.1 and 16.8 per 10 000 ECT treatments respectively. The most common medical events were falls (2.7 and 5.5 per 10 000 ECT treatments) and pneumonia (1.8 and 3.8 per 10 000 ECT treatments). Fewer than six deaths occurred on the day of an ECT treatment. This corresponded to a mortality rate of less than 0.4 per 10 000 treatments. Deaths within 7 and 30 days of an ECT treatment, excluding deaths due to external causes (e.g., accidental and intentional causes of death), were 1.0 and 2.4 per 10 000 ECT treatments respectively.

CONCLUSION

Morbidity and mortality events after ECT treatments were relatively low, supporting ECT as a low-risk medical procedure.

Disease characterization of systemic lupus erythematosus (SLE) patients in Quebec

Objective Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by an array of organ manifestations that can appear during flares and disappear during remissions. The objectives of this study were: (i) to examine SLE manifestation groups longitudinally in an SLE cohort; and (ii) to assess the association between early antimalarial treatment and renal manifestations. Methods Seven SLE manifestation groups-cutaneous, hematologic, lung, musculoskeletal, neuropsychiatric, serositis, renal-were tracked using Kaplan-Meier survival curves in an incident SLE cohort from Quebec health administrative data ( n = 2010). A subgroup with provincial drug insurance coverage was followed over time to examine the association between early antimalarial treatment (within three months after SLE diagnosis) and renal manifestations using a Cox proportional hazards survival model. Results Cutaneous manifestations was the most common manifestation at SLE diagnosis (30.0%, 95% CI: 27.7-32.2%). About two-thirds (66.2%, 95% CI: 63.4-68.9%) of patients had evidence of at least one SLE manifestation at diagnosis, which increased to 87.2% (95% CI: 84.2-90.3%) by the end of follow-up. After adjusting for age, sex, early concomitant systemic steroid therapy, Charlson comorbidity index, primary care visits in the year prior and other SLE manifestations at baseline, no statistically significant association was established between antimalarial therapy and renal manifestations. Conclusion This study provides insight regarding organ manifestations within a population-based sample. Most patients identified with SLE had other diagnostic evidence that supports an underlying diagnosis of SLE. No protective effects for antimalarial agents against renal manifestations could be established in this population-based cohort.

Evaluation of DNA methylation at imprinted DMRs in the spermatozoa of oligozoospermic men in association with MTHFR C677T genotype

Altered DNA methylation has been previously identified in the spermatozoa of infertile men; however, the origins of these errors are poorly understood. DNA methylation is an epigenetic modification which is thought to play a fundamental role in male germline development. DNA methylation reactions rely on the cellular availability of methyl donors, which are primarily products of folate metabolism, where a key enzyme is methylenetetrahydrofolate reductase (MTHFR). The MTHFR C677T single nucleotide polymorphism (SNP) reduces enzyme activity and may potentially alter DNA methylation processes during germline development. The objective of this study was to determine whether altered DNA methylation in spermatozoa is associated with the MTHFR C677T SNP. DNA methylation was evaluated at the H19, IG-GTL2, and MEST imprinted differentially methylated regions in the spermatozoa of 53 men - 44 oligozoospermic men and nine fertile men with normal sperm parameters via bisulfite sequencing of sperm clones. The 44 infertile men were stratified by severity of oligozoospermia - three normal (>15 million spermatozoa/mL), eight moderate (5-15 million spermatozoa/mL), 23 severe (1-5 million spermatozoa/mL), and 10 very severe (<1 million spermatozoa/mL). MTHFR C677T SNP genotyping was conducted in a subset of 44 peripheral blood samples via restriction fragment length polymorphism. A total of three men - severe oligozoospermic and CT genotype - were found to be altered, which is defined as having ≥50% of their clones altered, where an altered clone was in turn defined as ≥50% of CpGs with incorrect DNA methylation patterns. The incidence of three altered men within the CT subgroup, however, was not significantly higher than the incidence in the CC subgroup. Taken together, altered DNA methylation in spermatozoa was not significantly associated with the MTHFR C677T SNP; however, there was a trend for higher incidence of alterations among severe oligozoospermic infertile men with CT genotypes.

Damage-inducible intragenic demethylation of the human TP53 tumor suppressor gene is associated with transcription from an alternative intronic promoter

Wild-type TP53 exons 5-8 contain CpG dinucleotides that are prone to methylation-dependent mutation during carcinogenesis, but the regulatory effects of methylation affecting these CpG sites are unclear. To clarify this, we first assessed site-specific TP53 CpG methylation in normal and transformed cells. Both DNA damage and cell ageing were associated with site-specific CpG demethylation in exon 5 accompanied by induction of a truncated TP53 isoform regulated by an adjacent intronic promoter (P2). We then synthesized novel synonymous TP53 alleles with divergent CpG content but stable encodement of the wild-type polypeptide. Expression of CpG-enriched TP53 constructs selectively reduced production of the full-length transcript (P1), consistent with a causal relationship between intragenic demethylation and transcription. 450K methylation comparison of normal (TP53-wildtype) and cancerous (TP53-mutant) human cells and tissues revealed focal cancer-associated declines in CpG methylation near the P1 transcription start site, accompanied by rises near the alternate exon 5 start site. These data confirm that site-specific changes of intragenic TP53 CpG methylation are extrinsically inducible, and suggest that human cancer progression is mediated in part by dysregulation of damage-inducible intragenic CpG demethylation that alters TP53 P1/P2 isoform expression. © 2015 The Authors. Molecular Carcinogenesis Published by Wiley Periodicals, Inc.

Structural and biophysical characterization of the α-carbonic anhydrase from the gammaproteobacterium Thiomicrospira crunogena XCL-2: insights into engineering thermostable enzymes for CO2 sequestration

Biocatalytic CO2 sequestration to reduce greenhouse-gas emissions from industrial processes is an active area of research. Carbonic anhydrases (CAs) are attractive enzymes for this process. However, the most active CAs display limited thermal and pH stability, making them less than ideal. As a result, there is an ongoing effort to engineer and/or find a thermostable CA to fulfill these needs. Here, the kinetic and thermal characterization is presented of an α-CA recently discovered in the mesophilic hydrothermal vent-isolate extremophile Thiomicrospira crunogena XCL-2 (TcruCA), which has a significantly higher thermostability compared with human CA II (melting temperature of 71.9°C versus 59.5°C, respectively) but with a tenfold decrease in the catalytic efficiency. The X-ray crystallographic structure of the dimeric TcruCA shows that it has a highly conserved yet compact structure compared with other α-CAs. In addition, TcruCA contains an intramolecular disulfide bond that stabilizes the enzyme. These features are thought to contribute significantly to the thermostability and pH stability of the enzyme and may be exploited to engineer α-CAs for applications in industrial CO2 sequestration.

Association of proinflammatory cytokines and chemotherapy-associated cognitive impairment in breast cancer patients: a multi-centered, prospective, cohort study

BACKGROUND

Existing evidence suggests that proinflammatory cytokines play an intermediary role in postchemotherapy cognitive impairment. This is one of the largest multicentered, cohort studies conducted in Singapore to evaluate the prevalence and proinflammatory biomarkers associated with cognitive impairment in breast cancer patients.

PATIENTS AND METHODS

Chemotherapy-receiving breast cancer patients (stages I-III) were recruited. Proinflammatory plasma cytokines concentrations [interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-8, IL-10, granulocyte-macrophage colony-stimulating factor, interferon-γ and tumor necrosis factor-α] were evaluated at 3 time points (before chemotherapy, 6 and 12 weeks after chemotherapy initiation). The FACT-Cog (version 3) was utilized to evaluate patients' self-perceived cognitive disturbances and a computerized neuropsychological assessment (Headminder) was administered to evaluate patients' memory, attention, response speed and processing speed. Changes of cognition throughout chemotherapy treatment were compared against the baseline. Linear mixed-effects models were applied to test the relationships of clinical variables and cytokine concentrations on self-perceived cognitive disturbances and each objective cognitive domain.

RESULTS

Ninety-nine patients were included (age 50.5 ± 8.4 years; 81.8% Chinese; mean duration of education = 10.8 ± 3.3 years). Higher plasma IL-1β was associated with poorer response speed performance (estimate: -0.78; 95% confidence interval (CI) -1.34 to -0.03; P = 0.023), and a higher concentration of IL-4 was associated with better response speed performance (P = 0.022). Higher concentrations of IL-1β and IL-6 were associated with more severe self-perceived cognitive disturbances (P = 0.018 and 0.001, respectively). Patients with higher concentrations of IL-4 also reported less severe cognitive disturbances (P = 0.022).

CONCLUSIONS

While elevated concentrations of IL-6 and IL-1β were observed in patients with poorer response speed performance and perceived cognitive disturbances, IL-4 may be protective against chemotherapy-associated cognitive impairment. This study is important because cytokines would potentially be mechanistic mediators of chemotherapy-associated cognitive changes.

Abstract LB-85: Damage-inducible intragenic demethylation activates transcription of an alternative intronic promoter in TP53-wildtype but not mutant human cells and tumors

Unlike the well-known effects of promoter methylation, the functional significance of altered intragenic (gene body) CpG methylation remains unclear, particularly in genes such as the TP53 tumor suppressor which lack a 5′ CpG island. Here we show that CpG-specific demethylation of TP53 exon 5 in normal human and mouse cells is inducible by X-irradiation; this is accompanied by co-expression of a 5′-truncated TP53 isoform, raising the possibility that demethylation permits transcription from the known alternative promoter (P2) in intron 4. Consistent with this, in vivo expression of fully pre-methylated TP53 exonic constructs is associated with reduced basal and damage-inducible expression of both full-length and truncated TP53. In contrast, virally TP53-reconstituted Caco-2 and PC-3 human cancer cell lines respond to damage by upregulating expression of full-length TP53 and reducing expression of the truncated RNA isoform; CDKN1A expression varies directly with P2 isoform expression but inversely with the P1 transcript in these cells, suggesting that the isoform mediates downstream transactivation. 450K methylation analysis of adjacent normal and TP53-mutated human pancreatic cancer tissues suggests a mutation-specific decrease of intragenic TP53 methylation in intron 1 near P1 (p &lt; 0.02 ) and a reciprocal increase in intron 4 near P2 (p &lt; 0.01). Archival TP53 database analysis indicates that CpG-specific mutation frequency in human tumors is inversely associated with damage-inducible demethylation at the same sites in vitro (Spearman coefficient -7.1 ), consistent with methylation-dependent downregulation of transcription-coupled repair. We conclude that intragenic alterations of TP53 methylation are both physiologically inducible and functional, and hypothesise that tumor progression is drivable by either (i) intragenic hypermethylation affecting P1 as a field defect in TP53-wt tumor or adjacent normal tissues, or (ii) damage-inducible repression of P2 isoform expression associated with defective intron 4 demethylation, together with overexpression of full-length p53, in TP53-mutant tumors and cells.

Citation Format: James Blackburn, Robert Ng, Daniel Roden, Jianmin Wu, Richard J. Epstein. Damage-inducible intragenic demethylation activates transcription of an alternative intronic promoter in TP53-wildtype but not mutant human cells and tumors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-85. doi:10.1158/1538-7445.AM2014-LB-85

Long-term outcome and quality of life after supercharged jejunal interposition for oesophageal replacement

BACKGROUND

The consequences of major conduit necrosis following oesophagectomy are devastating. Jejunal interposition with vascular supercharging is an alternative reconstructive method if colon is unavailable. Aims of this study were to review the long-term outcome and quality of life of patients undergoing this surgery in our tertiary unit.

METHODS

Patients undergoing oesophageal reconstruction with supercharged jejunum were identified and retrospective review of hospital notes performed. Each patient was then interviewed for follow up data and quality of life assessment using the EORTC QLQ-C30 questionnaire.

RESULTS

Six patients (5 men) (median age 59 years (range 34-72) underwent supercharged pedicled jejunal (SPJ) interposition from May 2005-August 2010. Indications for surgery were loss of both gastric and colonic conduits following surgery for oesophageal cancer (n = 4), loss of gastric conduit and previous colectomy (n = 1) and lastly, gastric and colonic infarction in a strangulated paraoesophageal hernia (n = 1). Median time to reconstruction was 12 months [6-15 range]. There were no in-hospital deaths. Median postoperative stay was 46 days [13-118]. Three patients required surgical re-intervention for leak, sepsis and reflux, respectively. Median follow up was 6.5 years [range 7-102 months]. One patient died seven months following surgery due to respiratory complications. On follow up, 5 patients have an enteral diet without supplemental nutrition, maintaining weight and good quality of life scores.

CONCLUSIONS

Supercharged jejunal interposition is a suitable alternative conduit for delayed oesophageal replacement in patients with otherwise limited reconstructive options. Good functional outcomes can be achieved despite formidable technical challenges in this group.

Use of electroacupuncture to accelerate the antidepressant action of selective serotonin reuptake inhibitors: a single-blind, randomised, controlled study

1. Patients treated with dense cranial electroacupuncture stimulation (DCEAS) had a significantly greater reduction in the 17-item Hamilton Rating Scale for Depression scores and clinically significant response to treatment than those having sham acupuncture (19.4% vs.8.8%). 2. Neither sham acupuncture nor DCEAS had effects on the platelet serotonin system. 3. In the early phase of selective serotonin reuptake inhibitor treatment for depressed patients, DCEAS could be used as an additional therapy. 4. Neurobiological mechanisms responsible for DCEAS effects warrant further investigation using neuroimaging.

Parvoviruses: structure and infection

Parvoviruses package a ssDNA genome. Both nonpathogenic and pathogenic members exist, including those that cause fetal infections, encompassing the entire spectrum of virus phenotypes. Their small genomes and simple coding strategy has enabled functional annotation of many steps in the infectious life cycle. They assemble a multifunctional capsid responsible for cell recognition and the transport of the packaged genome to the nucleus for replication and progeny virus production. It is also the target of the host immune response. Understanding how the capsid structure relates to the function of parvoviruses provides a platform for recombinant engineering of viral gene delivery vectors for the treatment of clinical diseases, and is fundamental for dissecting the viral determinants of pathogenicity. This review focuses on our current understanding of parvovirus capsid structure and function with respect to the infectious life cycle.

Use of myocutaneous flaps for perineal closure following abdominoperineal excision of the rectum for adenocarcinoma

INTRODUCTION

Abdominoperineal excision (APE) following radiotherapy is associated with a high rate of perineal wound complications. The use of myocutaneous flaps may improve wound healing. We present our experience using myocutaneous flaps for immediate reconstruction.

METHOD

Prospective data were collected on patients undergoing APE from October 2003 to December 2008. Patient demographics, operating time, wound complications and length of stay were recorded.

RESULTS

Fifty-one patients underwent APE for rectal adenocarcinoma, 21 had primary closure and 30 had myocutaneous flap closure (24 VRAM, 6 gracilis). The proportion of patients undergoing preoperative radiotherapy in each group were 62% and 93% respectively (P = 0.011). There were no major complications following primary closure of the unirradiated perineum. Major perineal wound complications requiring reoperation or debridement were seen in three (14%) patients following primary closure and five (17%) patients with flap closure. After radiotherapy, closure with a flap reduced the length of stay from 20 to 15 days, but this difference was not statistically significant (P = 0.36).

CONCLUSION

The use of flap closure in irradiated patients is associated with fewer perineal complications and a shorter hospital stay.

Crystal structure of YfeU protein from Haemophilus influenzae: a predicted etherase involved in peptidoglycan recycling

The crystal structure of the H. influenzae YfeU protein, was determined at 1.90 A resolution using multi-wavelength anomalous diffraction. YfeU belongs to a very large conserved family of proteins found mainly in bacteria but also in archaea and eukaryota. The protein is a homolog of eukaryotic glucokinase regulator and is predicted to be a sugar phosphate isomerase or aminotransferase. Here we describe the structure of YfeU and discuss the possible function as an etherase possibly involved in peptidoglycan recycling.