Cloning and periplasmic soluble expression of hepatitis B surface antigen gene in Escherichia coli

OBJECTIVE

The objective of this study was to clone and express the hepatitis B surface antigen gene (HBsAg) in Escherichia coli (E. coli), thereby aiming to develop potential local therapeutics for combating Hepatitis B virus (HBV) infection in the Pakistani community by producing HBsAg in E. coli.

MATERIALS AND METHODS

Blood serum samples were collected from hepatitis B-infected patients, and their genomic DNA was extracted. Real-time and nested polymerase chain reaction (PCR) was performed to amplify the HBsAg gene. The gene of interest was cloned into the pET20b expression vector and transformed into E. coli BL21 (DE3) using Isopropyl β-D-1-thiogalactopyranoside (IPTG) induction. The gene's precise size was confirmed with gene-specific external and internal primers (681 bp and 400 bp, respectively).

RESULTS

The HBsAg gene was successfully sequenced and submitted to GenBank, exhibiting 98% homology with targeted HBV sequences worldwide. The expression of HBsAg protein was confirmed through silver staining, Coomassie staining, western blot, and dot blot analysis.

CONCLUSIONS

The expressed protein clones are now available for further development as a local recombinant DNA vaccine to prevent hepatitis B viral infection in the local community.

Low Incidence of Late Lymphopenia Following Stereotactic Body Radiotherapy for Localized Prostate Cancer

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) is increasing in use for the treatment of localized prostate cancer. The utilization of highly conformal photon therapy such as SBRT may increase the whole-body integral dose. Lymphocytes are very radiation sensitive. This dose increase could lead to unintended consequences such as lymphopenia. Prior studies have shown that lymphopenia following radiation therapy may negatively impact long-term outcomes. This study sought to evaluate the incidence and timeline of chronic lymphopenia following prostate SBRT.

MATERIALS/METHODS

Institutional IRB (IRB#: 2012-1175) approval was obtained. The absolute lymphocyte count was measured 1-2 hours prior to robotic SBRT (35-36.25 Gy in 5 fractions) and at each follow-up (3, 6, 12, 18 and 24 months). Lymphopenia was graded using the CTCAEv.4: Grade 1 (1.0-0.8 k/μl), Grade 2 (0.8-0.5 k/μl), Grade 3 (0.5-0.2 k/μl) and Grade 4 (<0.2 k/μl). Late lymphopenia was defined as lymphopenia occurring 3 or more months post-SBRT.

RESULTS

From 2019 to 2022, 198 localized prostate cancer patients (23 low-, 148 intermediate-, and 27 high-risk according to the D'Amico classification) at a median age of 73.5 years were treated with SBRT (35-36.25 Gy) at Georgetown University Hospital on a prospective clinical trial. Baseline lymphopenia was uncommon: Grade 1 (3.5%), Grade 2 (1.5%) and Grade 3 (0%). The baseline ALC of 1.9 k/μl decreased to 1.5 k/μl at 3 months post-SBRT and then remained stable for the remainder of the two-year follow-up. Overall, 14.6% of men experienced lymphopenia in the two years following SBRT: Grade 1 (7.6%), Grade 2 (6.6%) and Grade 3 (0.5%). No patient experienced Grade 4 lymphopenia.

CONCLUSION

Prostate SBRT leads to a low rate of late lymphopenia with the vast majority of toxicities being low grade. The peak incidence occurred at 3 months post-SBRT. Resolution of lymphopenia occurs in most patients within two years after SBRT. Future studies should explore the possible impact on quality of life and cancer control outcomes.

Evidence of novel Treponema phylotypes implicated in contagious ovine digital dermatitis and association of treponemes with major lameness causing foot pathogens

In this study 269 swabs collected from 254 ovine foot lesions and 15 apparently healthy ovine feet were screened by PCR for the presence of major lameness causing foot pathogens viz. Treponema species, D. nodosus, F. necrophorum and T. pyogenes with the presumption that ovine foot lesion positive for Treponema species alone or in association with other three pathogens were categorized as contagious ovine digital dermatitis (CODD). While samples positive for D. nodosus alone or its combination with F. necrophorum and T. pyogenes were considered as footrot (FR) and samples in which F. necrophorum or T. pyogenes was found either alone or in combination were considered as interdigital dermatitis (ID). The overall occurrence of Treponema sp. in ovine foot lesions was 48.0%, and ranged from 33 to 58%. In Treponema positive samples D. nodosus, F. necrophorum and T. pyogenes were present in 34 (27.4%), 66 (54.4%) and 84 (68.5%) in contrast to Treponema negative samples in which these were present in 15 (11.1%), 20 (14.12%) and 17 (12.6%) samples, respectively. The data signifies that Treponema sp. are significantly associated with these foot pathogens and their different combinations with Treponema sp. influence the severity of CODD lesion. The identification of Treponema phylotypes was done by sequencing the 16S rRNA gene fragment of ten representative samples. Out of ten sequences, four (Trep-2, Trep-4, Trep-7 and Trep-10) were identical to Treponema sp. phylotype 1 (PT1) that belongs to phylogroup T. refringens-like, one sequence (Trep-1) was genetically close (90% sequence homology) to Treponema brennaborense while five sequences (Trep-3, Trep-5, Trep-6, Trep-8 and Trep-9) matched with uncultured bacterium clones of treponemes forming separate monophyletic group in phylogenetic tree and could represent new digital dermatitis phylogroup presently containing five ovine specific phylotypes. This is the first report on the presence of Treponema phylotypes other than three digital dermatitis (DD) Treponema phylogroups viz. T. phagedenis-like, T. medium/T. vincentii-like, and T. pedis-like that are frequently detected in CODD lesions. Metagenomic analysis of two representative samples revealed the abundance of genus Treponema in CODD lesion while this genus was absent in swab collected from clinically healthy foot suggesting that it might play primary role in producing CODD. These findings may further aid in understanding the etiopathogenesis of CODD and could help to develop appropriate treatment and mitigation strategies to combat the disease.

Impact of COVID-19 & Response Measures on HIV-HCV Prevention Services and Social Determinants in People Who Inject Drugs in 13 Sites with Recent HIV Outbreaks in Europe, North America and Israel

HIV/HCV prevention among people who inject drugs (PWID) is of key public health importance. We aimed to assess the impact of COVID-19 and associated response measures on HIV/HCV prevention services and socio-economic status of PWID in high-HIV-risk sites. Sites with recent (2011-2019) HIV outbreaks among PWID in Europe North America and Israel, that had been previously identified, were contacted early May 2020. Out of 17 sites invited to participate, 13 accepted. Semi-structured qualitative site reports were prepared covering data from March to May 2020, analyzed/coded and confirmed with a structured questionnaire, in which all sites explicitly responded to all 103 issues reported in the qualitative reports. Opioid maintenance treatment, needle/syringe programs and antiretroviral treatment /hepatitis C treatment continued, but with important reductions and operational changes. Increases in overdoses, widespread difficulties with food and hygiene needs, disruptions in drug supply, and increased homelessness were reported. Service programs rapidly reformed long established, and politically entrenched, restrictive service delivery policies. Future epidemic control measures should include mitigation of negative side-effects on service provision and socio-economic determinants in PWID.

Analysis of mitochondrial DNA mutations in Pakistani population diagnosed with cardiovascular diseases

Heart and blood vessel disorders, such as coronary heart disease, brain vessel disease, rheumatic heart disease, and others, are together referred to as cardiovascular disease (CVD). In this study, we sought to determine how mitochondrial Leucine Transfer RNA genes and CVDs are related (MT-L1 and MT-L2). From CVD patients in Peshawar, a total of 27 saliva samples were taken. Leu-tRNA genes expressed by mitochondria were amplified using polymerase chain reaction after DNA was removed. Ten samples were sent for sequencing after PCR and gene cleaning. We obtained all of the sequenced results, which were subsequently aligned and evaluated against the mitochondrial revised Cambridge Reference Sequence (rCRS). However, in our sequenced samples, Leu-tRNA MT-L1 and MT-L2 genes were determined to be unaltered. Thus, it is suggested that a large population be taken into account while screening for mutations in the mitochondrial encoded Leu-tRNA MT-L1 and MT-L2 genes of cardiac patients in areas of Pakistan. Additionally, it is recommended that patients with cardiac problems should also have other mitochondrial encoded genes checked for potential mutations. This could result in the identification of genetic markers that could be used for early CVD screening in Pakistan.

Beliefs, behaviour, and blood pressure: preliminary analysis from a pharmacy-based hypertension visualisation intervention to support medication adherence

Introduction

Hypertension is the leading preventable risk factor for cardiovascular disease, with an estimated prevalence of 31% worldwide1. Antihypertensive medication reduces both blood pressure (BP) and cardiovascular risk; however, approximately 50% of patients become nonadherent to antihypertensives within a year of treatment initiation2. Nonadherence can be considered as either intentional or unintentional. Research suggests that rather than being a solely passive process, illness beliefs and treatment perceptions may influence nonintentional nonadherence3, highlighting the importance of considering patients’ beliefs when supporting adherence. The use of visuals is one method to aid understanding of complex health information and influence treatment beliefs.

Aim

To investigate the feasibility and acceptability of a community pharmacy-based visualisation intervention (ViSTA-BP) and explore the preliminary effect on patients’ perceptions of hypertension, medication adherence and blood pressure.

Methods

ViSTA-BP is a digital intervention that allows users, through real-time animations, to visualise both the condition that is hypertension and how blood pressure affects the circulatory system. The purpose of ViSTA-BP was to improve patients’ understanding of hypertension, increase perceived necessity of treatment and ultimately support medication adherence. A mixed-methods pre-post design pilot study was conducted. NHS Research Ethics Committee Wales Rec 5 (reference 20/WA/0280) and Cardiff Metropolitan University (reference PGR-3806) granted ethical approval. The intervention was consultation-based and researcher-facilitated. Outcomes were recorded at baseline, immediately post-intervention, and at three-months. Validated questionnaires were used to measure illness and treatment beliefs (Brief Illness Perception Questionnaire (B-IPQ)/Beliefs about Medicines Questionnaire (BMQ)), adherence captured using self-report measures (Medicines Adherence Rating Scale (MARS-5)/recent adherence questionnaire) and medication dispensing/collection data. BP was measured at baseline and 3-month follow-up. Semi-structured interviews with patients and pharmacists explored intervention acceptability.

Results

Pharmacists recruited 69 patients with hypertension across five community pharmacies (CP) in South Wales; 54 attended the three-month follow-up. The ease of participant recruitment and high retention rates demonstrated the feasibility of delivering ViSTA-BP in this setting. ViSTA-BP content and the CP location were acceptable to patients and pharmacists. Time to deliver the intervention was a concern for pharmacists but not patients. There was no statistically significant change in adherence outcomes at three-month follow-up; however, the median scores for both self-report questionnaires were maximal at baseline. Changes were seen in illness belief scores, with a significant improvement in total B-IPQ score over time (p=0.04). Significant changes in B-IPQ treatment control (p=0.01), illness coherence (p&lt;0.001) and BMQ Necessity subscale scores (p=0.003) were reported at all time-points. There was a statistically significant improvement in both systolic (SBP) (p&lt;0.01) and diastolic BP (DBP) (p=0.03) three-months post-intervention. At baseline, 31% of participants had SBP at or below the UK target; however, at three-month follow-up, 59% were at or below the UK target.

Discussion/Conclusion

ViSTA-BP was considered a feasible researcher-facilitated intervention in this CP setting. Improvements seen in blood pressure control, patients’ understanding of hypertension, and perceptions of utility and necessity of treatment highlight the potential for the ViSTA-BP intervention to help reduce cardiovascular risk in the future. While preliminary analysis shows promise, further adequately powered research studies are necessary to evaluate future ViSTA-BP impact.

References

1. Mills KT, Stefanescu A, He J. The global epidemiology of hypertension. Nat Rev Nephrol. 2020;16(4):223-237. doi:10.1038/s41581-019-0244-2

2. Vrijens B, Antoniou S, Burnier M, de la Sierra A, Volpe M. Current situation of medication adherence in hypertension. Front Pharmacol. 2017;8. doi:10.3389/fphar.2017.00100

3. Gadkari AS, McHorney CA. Unintentional non-adherence to chronic prescription medications: how unintentional is it really? BMC Health Serv Res. 2012;12(1):98. doi:10.1186/1472-6963-12-98

Anti-Claw Procedure with Modified Dynamic Flexor Digitorum Superficialis Transfer for Ulnar Nerve Palsy: Our Experience

Introduction

The ulnar nerve palsy is a distressing injury, resulting in clawing of hand. The cause of clawing is due to paralysis of the interosseous muscles in the presence of functioning long extensor and long flexors of fingers. Various methods have been proposed to correct this deformity which include both static and dynamic procedures. In this study, we share our experience with flexor digitorum superficialis tendon transfer using Zancolli's modification for anti-claw correction.

Materials and methods

It was a retrospective case series study. A record of 53 patients was included in the study, during a period between June 2013 to July 2017 with ulnar nerve palsy. The procedure done was flexor digitorum superficialis tendon transfer as dynamic anti-claw procedure. The follow-up period was three months. The outcomes assessed were grip strength by using sphygmomanometer and active range of motion of fingers assessed by fingers tips touching the palm.

Result

Fifty-three patients were included out of them, there were fifty males and three females. The mean age was 28±10 years. All patients underwent flexor digitorum superficialis transfer for ulnar claw hand. A total of 84.9% patients have good grip strength and 83% showed good active range of motion.

Conclusion

Flexor digitorum superficialis tendon transfer is found to be effective, reliable and reproducible technique in ulnar nerve palsy where patient need grip strength, good range of motion and acceptable hand function for daily routine work.

144 A PILOT STUDY TO BENCHMARK FRAILTY NEEDS IN AN ACUTE OLDER SURGICAL INPATIENTS

Background

Evidence to support screening for frailty among acute surgical inpatients is limited. Our aim was to identify surgical inpatients on a general/vascular surgery ward with unmet, frailty-associated needs.

Methods

From 01/03/2022 to 12/04/2022, all inpatients under a vascular/general surgery service in a model 4 hospital were screened for frailty using a modified THINKfrail tool. An abbreviated CGA (‘little g’), to identify what matters to the patient, mobility and functional impairment, mood and mental state and medication review was performed and actions taken on the results.

Results

138 patients were admitted under the surgical teams during the study period. 30% (n=42) were over 70 years. 8% (n=11) screened positive for frailty, all of whom underwent a ‘little g’. The mean (SD) age was 77 (4) years. 45% (n=5) were male. Identified needs were included abnormal 4AT in 50% (n=5), 3 of whom had no prior diagnosis of dementia. 45% had altered ADLs resulting in a reduced ability to dress or mobilise. 80% (N=9) required optimisation of mobility and/or physical function. 45% (n=5) had medication changes made.

Conclusion

A simple modified THINKfrail tool can be implemented by surgical nurses to screen for patients who may need geriatric input. Most have physio and OT needs and 45-50% have undetected cognitive or medication related issues, detected by employing a ‘little g’. Employing a ward-based frailty screen, followed by little g assessment is effective. This approach should be prospectively validated.

Clopidogrel monotherapy following dual antiplatelet therapy in patients with acute coronary syndrome post-drug-eluting stent implantation: a systematic review and direct/indirect treatment comparison

Background

In patients with acute coronary syndromes (ACS) receiving a drug-eluting stent (DES), treatment with dual antiplatelet therapy (DAPT) reduces the risk of recurrent ischemic events. Optimal duration of DAPT depends on patient characteristics and switching to single antiplatelet therapy (SAPT) is recommended after the course of DAPT.

Purpose

The aim of this study was to evaluate the comparative efficacy and safety of switching to clopidogrel SAPT following DAPT in patients with ACS post DES-implantation.

Methods

A systematic literature review (SLR) was conducted by searching MEDLINE®, Embase, and CENTRAL up to July 27, 2021. Randomized controlled trials (RCTs) and observational studies that evaluated clopidogrel SAPT following DAPT in adults with ACS post-DES implantation were included. Heterogeneity of included studies was vetted in a feasibility assessment. Random effects meta-analyses were conducted using the metafor package for R. Direct comparisons were conducted for clopidogrel vs. aspirin and clopidogrel vs. DAPT. Using the Bucher method, aspirin vs. DAPT was indirectly compared by taking the difference between their respective pooled treatment effects vs. clopidogrel. A sensitivity analysis was conducted by including studies with a follow-up of 12 months.

Results

Of 5,349 records identified, seven unique studies (four RCTs and three observational studies) were eligible to be included in the SLR and quantitative treatment comparison. Risk of major adverse cardiovascular events (MACE) was lower in patients who switched to clopidogrel SAPT after DAPT compared with those who switched to aspirin monotherapy (hazard ratio [HR]: 0.72; 95% confidence interval [CI]: 0.54, 0.98), and this difference was significant. No significant difference in risk of MACE was found between switching to clopidogrel SAPT after DAPT and continuation of DAPT (HR: 0.90; 95% CI: 0.65, 1.25). This finding was consistent with the sensitivity analysis representing studies with follow-up of 12 months (HR: 0.95; 95% CI: 0.69, 1.31). Risk of bleeding was not analysed due to insufficient data across included studies for patients with ACS. However, within-study findings from one RCT of 4,136 patients demonstrated a significantly lower risk of bleeding, defined as thrombolysis in myocardial infarction (major and/or minor, for switching to clopidogrel SAPT following DAPT compared with continuation of DAPT (0.54% vs. 1.17% of patients had bleeding [HR: 0.46; 95% CI: 0.23, 0.94]).

Conclusion

Findings from this SLR suggest switching to clopidogrel SAPT after DAPT in ACS post-DES implantation has a lower risk of MACE compared with switching to aspirin monotherapy, and no difference in the risk of MACE compared with continuation of DAPT. There was insufficient data across the included studies to evaluate the bleeding risk, however, a single study indicated a lower bleeding risk with switching to clopidogrel SAPT.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sanofi

Plasma hydroxyanthranilic acid as a predictor of stress induced myocardial ischemia in non-obstructive coronary artery disease

Background

The tryptophan catabolite hydroxyanthranilic acid (HAA) has potent immunomodulatory and vasoactive effects. HAA is also a precursor in the synthesis of nicotinamide adenine dinucleotide (NAD), a crucial cofactor in energy-metabolism. We have previously demonstrated that elevated plasma HAA predicted risk of myocardial infarction.

Purpose

To explore if plasma HAA is associated with stress induced myocardial ischemia in non-obstructive coronary artery disease (CAD).

Methods

In 132 patients with chest pain and non-obstructive CAD by coronary computed tomography angiography (CCTA), plasma HAA was analyzed by gas chromatography tandem mass spectrometry. All participants underwent myocardial contrast stress echocardiography. Myocardial ischemia was assessed as delayed contrast replenishment at peak dobutamine stress during real-time low mechanical index imaging and destruction replenishment. The extent of ischemia was defined as the number of segments with delayed contrast enhancement using a 17-segment left ventricular model. Associations of plasma HAA with myocardial ischemia was evaluated in a multivariate adjusted linear regression model.

Results

Mean (SD) age at inclusion was 63 (8) years and 56% were women. At CCTA, the median (25th, 75th percentile) coronary artery calcium (CAC) score was 42 (13–107) Agatston units, whereas the mean (SD) segment involvement score (SIS) was 2.6 (1.6). Myocardial ischemia was found in 52% of patients with on average 5 (3) ischemic segments per patient. Serum HAA did not correlate with the CAC score or SIS (p&gt;0.29). After multivariate adjustment including age, sex, body mass index, systolic blood pressure, diabetes, current smoking, and LDL cholesterol, the odds ratio and 95% confidence interval for myocardial ischemia was 1.55 (1.04–2.32), P=0.03, per SD increment of plasma HAA levels (log transformed). Plasma HAA was also associated with the extent of myocardial ischemia with a multivariate adjusted β of 0.26, P=0.004.

Conclusion

Plasma HAA is associated with the extent of myocardial ischemia in non-obstructive CAD. Potential roles of this metabolite in atherogenesis, vascular dysfunction and as a predictor of myocardial ischemia should be further elucidated.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Western Norway Regional Health Authority

Functional Outcome of Arthroscopic Anterior Cruciate Ligament Reconstruction Using Hamstring Autograft with Fixation Using Endobutton at Femoral End and Bioabsorbable Screw at Tibial End

Anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. It can be repaired and reconstructed by open and endoscopic method, the gold standard is, however, endoscopic reconstruction. It is usually reconstructed using bone patellar tendon bone (BPTB) or Hamstring autograft. The graft is supported using endobutton at the femoral end while bioabsorbable interference screw at the tibial end. This study aimed to determine how a certain fixation procedure for quadrupled hamstring autografts worked out. This prospective observational study duration period was 1 year in which 40 patients with ACL injury were treated with arthroscopic reconstruction using hamstring autograft from January 2020 to December 2020 with 6 months follow up after surgery. On the femoral side, an endobutton was used to secure the graft, while the tibial end was secured using a bioabsorbable screw. The International Knee Documentation Committee (IKDC) scoring system was used for prospective evaluation. According to subjective IKDC scoring, 20(50.0%) results were very good, 14(35.0%) were good, 4(10.0%) were satisfactory and 2(5.0%) were bad. In 95.0% patients the state of knee joint is very good compared to preoperative state. Of all the 40 patients underwent ACL reconstruction, 38(95.0%) patients are satisfied with the results of the operation.

The influence of anastomotic techniques on postoperative anastomotic complications: Results of the Oesophago-Gastric Anastomosis Audit

BACKGROUND

The optimal anastomotic techniques in esophagectomy to minimize rates of anastomotic leakage and conduit necrosis are not known. The aim of this study was to assess whether the anastomotic technique was associated with anastomotic failure after esophagectomy in the international Oesophago-Gastric Anastomosis Audit cohort.

METHODS

This prospective observational multicenter cohort study included patients undergoing esophagectomy for esophageal cancer over 9 months during 2018. The primary exposure was the anastomotic technique, classified as handsewn, linear stapled, or circular stapled. The primary outcome was anastomotic failure, namely a composite of anastomotic leakage and conduit necrosis, as defined by the Esophageal Complications Consensus Group. Multivariable logistic regression modeling was used to identify the association between anastomotic techniques and anastomotic failure, after adjustment for confounders.

RESULTS

Of the 2238 esophagectomies, the anastomosis was handsewn in 27.1%, linear stapled in 21.0%, and circular stapled in 51.9%. Anastomotic techniques differed significantly by the anastomosis sites (P < .001), with the majority of neck anastomoses being handsewn (69.9%), whereas most chest anastomoses were stapled (66.3% circular stapled and 19.3% linear stapled). Rates of anastomotic failure differed significantly among the anastomotic techniques (P < .001), from 19.3% in handsewn anastomoses, to 14.0% in linear stapled anastomoses, and 12.1% in circular stapled anastomoses. This effect remained significant after adjustment for confounding factors on multivariable analysis, with an odds ratio of 0.63 (95% CI, 0.46-0.86; P = .004) for circular stapled versus handsewn anastomosis. However, subgroup analysis by anastomosis site suggested that this effect was predominantly present in neck anastomoses, with anastomotic failure rates of 23.2% versus 14.6% versus 5.9% for handsewn versus linear stapled anastomoses versus circular stapled neck anastomoses, compared with 13.7% versus 13.8% versus 12.2% for chest anastomoses.

CONCLUSIONS

Handsewn anastomoses appear to be independently associated with higher rates of anastomotic failure compared with stapled anastomoses. However, this effect seems to be largely confined to neck anastomoses, with minimal differences between techniques observed for chest anastomoses. Further research into standardization of anastomotic approach and techniques may further improve outcomes.

A Novel Blockchain-Based Model for Blood Donation System

In Pakistan, existing blood control systems or blood information management systems are limited in terms of efficient data retrieval of donor to consumer. There is no communication network in place for extra blood in one location to be demanded from a region if blood is limited, resulting in blood wastage. Due to a lack of accessibility and sufficient blood quality testing, blood contaminated with illnesses such as HIV has been used for transfusion in some cases. This study proposes a ledger blood management system to address these challenges. The trail has been represented as a supply-chain management problem following the blood. By trailing the blood stream and donation a single platform for transferring blood and the problem results among blood groups, the proposed system, built on the hyperledger fabric model, adds more traceability toward the blood transfusion process. It also helps to reduce unjustified blood wastage by providing an integrated system for transferring lifeblood and the thing extracts among lifeblood banks. A web app is also designed for accessing the network for simplicity of usage and security is enhanced by implementing block chain hyperfebric ledger system through Key Value System (KVS) system.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Chemical divergence of the Juglans Regia L. across districts Swat and Dir, Khyber Pakhtunkhwa, Pakistan

Juglans regia L. are nutritious fruit bearing plants mostly found in Northern areas of Pakistan. The population of walnuts was explored from district Dir and Swat Khyber Pakhtunkhwa, Pakistan for their geographical, climatic and chemical divergence. The geographical differences such as altitude, latitude and longitude whereas climatic differences viz. soil EC, soil pH, precipitations, intensity of light, temperature and soil temperature. In both districts TPC ranged from 211.2±0.6 to 227.8±0.4 mg/100g, RSA ranged from 43.32±1.5% to 52.18±0.4%, conductivity ranged from 296.43±0.6 to 312.22±0.3 S/m and elemental composition such as iron, copper, calcium, zinc and magnesium in Dir differs from 0.312±0.032, 0.209±0.13, 20.0±0.313, 0.406±0.10 and 10.2±0.030 mg/L to 0.543±0.65, 0.698±0.82, 28.7±0.234, 0.685±0.15 and 17.6±0.015 mg/L respectively. Altitude and temperature showed a correlation with total phenolics contents and radical scavenging activity while soil pH, precipitations, soil temperature, soil Ec and light intensity indicated a weak correlation with chemical traits of walnuts. Further studies of walnuts are needed to explore their therapeutically important phytochemicals to succeed naturally pharmaceutical nutrients of the maximum significance for the health of human beings.

Textbook outcome following oesophagectomy for cancer: international cohort study

Background

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

Methods

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

Results

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter ‘no major postoperative complication’ had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P &lt; 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P &lt; 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

Conclusion

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Textbook outcome following oesophagectomy for cancer: international cohort study

BACKGROUND

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

METHODS

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

RESULTS

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter 'no major postoperative complication' had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

CONCLUSION

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Green synthesis of gold nanaoparticles using Delphinium Chitralense tuber extracts, their characterization and enzyme inhibitory potential

Green synthesis has been introduced as an alternative to chemical synthesis due to the serious consequences. Metal nanoparticles synthesized through green approach have different pharmaceutical, medical and agricultural applications. The present study followed a green and simple route for the preparation of potentially bioactive gold nanoparticles (Au NPs). Au NPs were prepared via green synthesis approach using crude basic alkaloidal portion of the tuber of Delphinium chitralense. The green synthesized Au NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) fourier transform infrared (FTIR), and UV-Visible spectrophotometer. Morphological analysis shows that Au NPs have cubic geometry with different sizes. UV-Vis spectroscopic analysis confirmed the synthesis of Au NPs while XRD proved their pure crystalline phase. The Au NPs showed promising dose dependent inhibition of both AChE and BChE as compared to the crude as well as standard drug.

Percentage Incidences of Bacteria in Mahseer (Tor putitora), Silver carp (Hypophthalmichthys molitrix) Fish Collected from Hatcheries and Local Markets of District Malakand and Peshawar of Khyber Pakhtunkhwa, Pakistan

Fish is the main source of animal protein for human diet. The aim of this study was to find out prevalence of pathogenic bacteria of two selected economically important fish of Pakistan namely Mahseer (Tor putitora) and Silver carp (Hypophthalmichthys molitrix). Live fish samples from hatcheries and dead fish samples from different markets of study area were randomly collected. The fish samples were analyzed for isolation, identification and prevalence of bacteria. The isolated bacteria from study fish were identified through biochemical test and about 10 species of pathogenic bacteria were identified including the pathogenic bacteria to human and fish namely, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus iniae, Serratia spp. Citrobacter spp. Stenotrophomonas spp. Bacillus spp. and Salmonella spp. The bacterial percentage frequency of occurrence in Silver carp and Mahseer fish showed Pseudomonas aeruginosa 21.42%, Staphylococcus epidermidis 17.85%, Escherichia coli 11.90%, Staphylococcus aureus 9.52%, Citrobacter spp. 9.52%, Serratia spp. 8.33%, Streptococcus iniae 7.14%, Stenotrophomonas spp. 5.95%, Bacillus spp. 4.76% and Salmonella spp. 3.57%. The study revealed that Fish samples of Mahseer and Silver carp that were collected from markets have found more isolates (10 bacterial species) than did the fresh fish pond samples (03 bacterial species) of hatcheries. The occurrence of pathogenic bacteria in study fish showed risk factor for public health consumers.

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND

The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting.

METHODS

Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups.

RESULTS

Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005).

CONCLUSION

Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.

The association between novel ST2, BNP, atrial fibrillation and heart failure

Background/Introduction

ST2, a novel marker of fibrosis has been proposed as a novel biomarker for heart failure. There is paucity of data suggesting its association with Atrial Fibrillation (AF), in particular, with regards to the its independent effect after adjustment for clinical factors and traditional biomarkers such as BNP. There is increasing evidence that inflammation and fibrosis are important players in the pathogenesis of AF, the most common arrhythmia that is associated with considerable morbidity.

Purpose

We sought to examine the association of ST2 with AF and its possible incremental value in combination with traditional biomarkers already used in routine clinical practice such as BNP.

Methods

Unselected patients presenting to a Cardiology service who had BNP for clinical reasons, concomitantly had ST2 sent. These patients included those with heart failure, acute coronary syndromes and AF, as well as patients attending cardioversion and cardiac catheterisation. The association between ST2, BNP and clinical factors was examined. ST2 was examined in tertiles as its distribution was highly skewed. Raised BNP was defined as usual (≥100 pg/ml).

Results

Of the 619 patients, the mean age was 69 years and 66% were male. The prevalence of co-morbidities were: Coronary heart disease - CHD (41%), Atrial Fibrillation – AF (30%), Heart Failure - HF (20%), Chronic Kidney Disease – CKD (23%). The mean eGFR was 68 ml/h and the mean LV ejection fraction was 55%. Both ST2 and BNP levels were significantly higher in patients with heart failure, CKD and AF. Mean levels of ST2 were (in ng/ml): HF vs no HF (65 vs. 38, p=0.0001) and in CKD vs. no CKD (49 vs. 41, p=0.001), CAD vs no CAD (43 vs. 42, p=0.3). Mean levels of BNP were (in pg/ml): HF vs no HF (579 vs. 131, p=0.0001), CKD vs. no CKD (379 vs. 173, p=0.0001), CAD vs. no CAD (239 vs. 206, p=0.5).

In patients with AF, levels of both ST2 and BNP were higher, as were their mean ages and prevalence of co-morbidities (see Table 1). Both ST2 and BNP correlated with AF (Pearson r=0.2, p&lt;0.0001 for ST2 and r=0.5, p&lt;0.0001 for BNP). There was also a graded association of ST2 with AF (15%, 33% and 40% across tertiles of ST2, p=0.0001).

Both ST2 and raised BNP were significant associated with AF in both univariable and multi-variable regression models, and remained independent predictors when adjusted for HF, CHD, LV EF and eGFR (Table 2, Model 2 – Relative risk ratio of AF with ST2 across tertiles 1.5, p0.005, and Odds ratio of AF with raised BNP 7.4, p&lt;0.001). However, ST2 loses significance when BNP is added to the model in combination (Table 2 – Model 3).

Conclusions

Both ST2 and BNP are independent predictors of AF even after adjustment for heart failure and other clinical factors. When ST2 is used in combination with BNP, raised BNP appears to be a stronger predictor of AF than ST2.

Funding Acknowledgement

Type of funding sources: None.

Impact of epicardial adipose tissue accumulation on left ventricular mass and hypertrophy in non-obstructive coronary artery disease

Introduction

Increased left ventricular mass index (LVMi) and left ventricular hypertrophy (LVH) by echocardiography are common in obesity and important cardiovascular risk predictors associated with myocardial ischemia in non-obstructive coronary artery disease (CAD). Accumulation of epicardial adipose tissue (EAT) suggest a possible direct impact on LVMi and LVH.

Purpose

To explore the association between EAT volume, LVMi and LVH in patients with chest pain and non-obstructive CAD.

Methods

We included 129 patients with chest pain and non-obstructive CAD (&lt;50% stenosis) by coronary computed tomography (CT) angiography. EAT volume was quantified using a semiautomatic analysis software on non-contrast cardiac CT images. Patients were grouped according to EAT volume, where high EAT volume was adjudicated when EAT volume was in the highest tertile (≥125 ml). Left ventricular mass was assessed by echocardiography, calculated by the Devereux formula and indexed for height in the allometric power of 2.7 (LVMi). LVH was defined as LVMi &gt;46.7 g/m2.7 in women and &gt;49.2 g/m2.7 in men. Coronary artery plaque burden was assessed as calcium score and segment involvement score on coronary CT angiography.

Results

High EAT volume was more common in men with higher BMI, waist circumference, serum triglycerides and higher prevalence of hypertension and obesity (all p&lt;0.05). Age, coronary calcium score and coronary artery segment involvement score did not differ between groups. Patients with high EAT volume had higher LVMi compared to those with low EAT volume (42.5 g/m2.7 vs. 36.1 g/m2.7, p=0.003), while there was no difference in EAT volume among patients with or without LVH. In univariable logistic regression analysis, high EAT volume was associated with higher LVMi (OR 1.05 [95% CI 1.01–1.10] per g/m2.7, p=0.015). After adjusting for hypertension and obesity in a multivariable model, higher LVMi remained significantly associated with high EAT volume (Model 1, Table 1), but the association was attenuated after adjusting for sex (Model 2, Table 1).

Conclusion

High EAT volume was associated with increased LVMi in patients with non-obstructive CAD, independent of hypertension and obesity, while there was no association with LVH. This suggest that direct infiltration of adipose tissue in the myocardium may contribute to the development of increased LVMi.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Western Norwegian Regional Health Authorities Table 1

Long-term outcomes of intravenous drug use associated infective endocarditis: a contemporary 20-year study

Introduction

Intravenous drug use (IVDU) associated infective endocarditis (IE) is a clinically challenging case. Not only can the natural history of IE in the IVDU population be significantly different, making detection a diagnostic dilemma, additional social factors associated with this population can drastically change management, including suitability for surgery or long-term intravenous access for antibiotics Furthermore, the rates of IVDU are increasing globally, leading to increasing incidence of IVDU associated IE.

Purpose

With a lack of clear mangement guidelines for IVDU associated IE, our study assesses the differences in presentation, management and long-term prognosis of IE between the IVDU population and the non-IVDU population to help guide future care.

Methods

This is an observational cohort study on a prospectively collected database of 350 patients treated for IE at our centre between 1999 and 2015. Patients were followed-up until death or January 2021. The primary outcome was all-cause mortality. Continuous variables were compared using unpaired t-test. Categorical variables were compared using Chi-square test when sample size was &gt;5 or Fisher's exact test when sample size was ≤5. Long-term survival data was analysed using Kaplan-Meier survival curves.

Results

The IVDU population was younger, more likely to have concurrent infections and other substance use, while the non-IVDU population was older with a higher level of overall comorbidity. IVDU patients were more likely to become reinfected (p-value=0.034) but had better long-term survival compared to the non-IVDU population (p&lt;0.001). Survival estimates at 15-years were 64.98% (95% CI: 50.94–75.92%) for the IVDU population compared to 26.67% (95% CI: 19.76–34.05%) for the non-IVDU population (p-value&lt;0.0001).

Conclusion

Despite having higher levels of reinfection, IVDU patients have better long-term outcomes of IE compared to non-IVDU patients. Therefore, IVDU patients should not have blanket restrictions on the management they are offered unless the individual has clear contraindications to a particular therapy.

Funding Acknowledgement

Type of funding sources: None.

143 Massive Intra-Hepatic Subcapsular Liver Haematoma Post-Laparoscopic Cholecystectomy- A Rare Complication of a Common Procedure'

Case Presentation

A 59-year-old female presented with symptomatic biliary colic. Her past medical history was noted for obesity (BMI&gt;50). She underwent an elective LC with an uncomplicated intraoperative course; however, post-operatively she developed hypovolaemic shock with an acute haemoglobin drop requiring fluid resuscitation and blood transfusion. Emergency CT revealed a massive subcapsular haematoma measuring 21cm×3.1cm× 17cm at the right liver margin without evidence of ongoing bleeding. She was managed conservatively- as per a tertiary hepatobiliary surgery centre’s advice- with meticulous clinical observations, serial monitoring of haemoglobin, and repeat CT to assess for interval progressions. She progressed well with conservative management and did not require surgical or radiological intervention. A follow-up liver sonography performed eight weeks post-discharge confirmed a complete resolution.

Conclusion

Giant ISH is an exceedingly rare but life-threatening complication following LC which merits special attention. Our case demonstrates the necessity of close postoperative monitoring of patients undergoing LC and considering the possibility of ISH in those who experience refractory postoperative hypotension. It also highlights the decisive role of diagnostic imaging in securing a timely and accurate diagnosis of post-LC ISH.

Prevalence of active HCV infection and genotypic distribution among the general population of district Mardan, Pakistan

Hepatitis C virus (HCV) is the serious global public health burden of liver disease. Approximately 170 million people in the world are infected with (HCV). In Pakistan, where the disease has high occurrence rate. The present study envisages an up-to-date prevalence of HCV and genotypic distribution in the general population of Mardan District, Khyber Pakhtunkhwa (KP), Pakistan. The blood samples from 6,538 individuals including 3,263 males and 3,275 females were analyzed for hepatitis C surface antigen by Immuno-chromatographic test (ICT), Enzyme-linked immunosorbent assay (ELISA), and reverse transcription-polymerase chain reaction (PCR). It was found that 396 (12.13%) out of 3263 individuals contained antibodies in their blood against HCV, while among the different age groups, the highest incidences of HCV antibodies were found in the 31-40 age group (11.01%). The ICT positive samples were further screened by nested PCR to determine the existence of active HCV-RNA. It was identified that 7.11% (3263) of the total population (6538) tested was positive, among which the 461 (14.07%) females possessed antibodies in their blood against HCV. Our data showed total HCV infection in the investigated population was 5.78%. Higher percentage of HCV prevalence was detected in males than females in the age group 31-40 and 41-50. To compare the prevalence of HCV genotypes age-wise in male and female genotype 3a was found most prevalent genotype followed by 1a, 2a and 3b, respectively.

Serological prevalence of hepatitis B virus (HBV) in Mardan district, Khyber Pakhtunkhwa, Pakistan

Hepatitis B virus infection is perilous among the five types of Hepatitis, as it remains clinically asymptomatic. The present study draws up-to-date prevalence of Hepatitis B virus (HBV) in the general population of Mardan, Khyber Pakhtunkhwa Pakistan. The blood samples from 4803 individuals including 2399 male and 2404 females were investigated. All the suspected samples were analyzed for hepatitis B surface antigen using Immuno-chromatographic test (ICT), Enzyme-linked immunosorbent assay (ELISA), and followed by Reverse transcription-polymerase chain reaction (RT-PCR). Results showed that 312 (13.00%) out of 2399 individuals contained antibodies in their blood against HBV, while among the different age groups, the highest incidences of HBV antibodies were found in the age of 21-30 groups (10.73%). Furthermore, the ICT positive samples were screened by nested polymerase chain reaction to detect the existence of active HBV-DNA. It was observed that 169 (7.04%) out of (2399) male of the total population (4803) tested was positive. On the other hand, the female 463 (19.25%) possessed antibodies in their blood against HBV. Accumulatively, our results showed a higher percentage of HBV prevalence in males than females in the age group 21-30 years. The total HCV infected in Mardan general population was recorded at 5.7% comprising both male and female.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Mortality from esophagectomy for esophageal cancer across low, middle, and high-income countries: An international cohort study

BACKGROUND

No evidence currently exists characterising global outcomes following major cancer surgery, including esophageal cancer. Therefore, this study aimed to characterise impact of high income countries (HIC) versus low and middle income countries (LMIC) on the outcomes following esophagectomy for esophageal cancer.

METHOD

This international multi-center prospective study across 137 hospitals in 41 countries included patients who underwent an esophagectomy for esophageal cancer, with 90-day follow-up. The main explanatory variable was country income, defined according to the World Bank Data classification. The primary outcome was 90-day postoperative mortality, and secondary outcomes were composite leaks (anastomotic leak or conduit necrosis) and major complications (Clavien-Dindo Grade III - V). Multivariable generalized estimating equation models were used to produce adjusted odds ratios (ORs) and 95% confidence intervals (CI95%).

RESULTS

Between April 2018 to December 2018, 2247 patients were included. Patients from HIC were more significantly older, with higher ASA grade, and more advanced tumors. Patients from LMIC had almost three-fold increase in 90-day mortality, compared to HIC (9.4% vs 3.7%, p < 0.001). On adjusted analysis, LMIC were independently associated with higher 90-day mortality (OR: 2.31, CI95%: 1.17-4.55, p = 0.015). However, LMIC were not independently associated with higher rates of anastomotic leaks (OR: 1.06, CI95%: 0.57-1.99, p = 0.9) or major complications (OR: 0.85, CI95%: 0.54-1.32, p = 0.5), compared to HIC.

CONCLUSION

Resections in LMIC were independently associated with higher 90-day postoperative mortality, likely reflecting a failure to rescue of these patients following esophagectomy, despite similar composite anastomotic leaks and major complication rates to HIC. These findings warrant further research, to identify potential issues and solutions to improve global outcomes following esophagectomy for cancer.

Food handlers: an important reservoir of protozoans and helminth parasites of public health importance

Food handlers plays a primary role in the transmission of pathogenically important protozoans and helminth parasites. This study was aimed to evaluate the prevalence of intestinal pathogenic protozoans and helminth parasites among food handlers in and around University of Malakand, Lower Dir, Pakistan. Stool samples were collected from 642 food handlers (all of male) in a cross-sectional study from January to November, 2017. Wet Mount Techniques and concentration methods by using salt and formol-ether solutions. Three hundred and eighty four cases (59.8%) were found infected with one more parasites. Most of the individuals were found infected with helminth (47.6%) as compared to intestinal protozoans (0.93%). Seventy two cases (11.2%) of the cases presented mixed infection with both intestinal protozoan and helminth parasites. The order of prevalence for intestinal helminth was Ancylostoma duodenale (n = 258, 40.1%), followed by Taeniasa ginata (n=96, 14.9%) Ascaris lumbricoides (n = 54, 8.40%) and Trichuris trichura (n=30, 4.60%). For intestinal protozoa, Entamoeba histolytica/dispar (n = 36, 5.64%) was the only protozoan detected. Mono-parasitism was higher than poly-parasitism. Family size income and education level were the factors significantly (P<0.05) associated in the parasites prevalence. Current research showed that IPIs are primarily the foodborne pathogens still an important public health problem in Pakistan. Effective control programs on parasitic diseases transfer and their associated factors are recommended.