Introducing a new proforma for the safe use of intraoperative tourniquets in orthopaedic surgery

INTRODUCTION

The routine use of pneumatic tourniquets in orthopaedic surgery is widely adopted in current practice; however, practice varies considerably based mainly on anecdotal and cultural traditions. This Quality Improvement Project evaluated current service as per the newly published British Orthopaedic Association Standards for Trauma & Orthopaedics guideline on 'The Safe Use of Intraoperative Tourniquets'.

METHODS

Patient records were reviewed retrospectively for all patients who underwent orthopaedic surgery in September 2021 at one NHS hospital trust. Simultaneously, a nine-question survey was distributed to the orthopaedic teams allowing assessment of non-quantifiable aspects of the guidelines. The results were delivered as a local presentation, and trust-wide dissemination of posters using the mnemonic 'PRESSURE' was used to educate staff. The quantitative audit was repeated twice, after this intervention (March 2022) and after the advent of a new electronic patient record system with an online proforma (January 2023).

RESULTS

There was significant improvement (p<0.05) in all aspects of tourniquet documentation between the audit cycles. Maximum advised tourniquet duration was exceeded in <2% of cases regardless of guideline publication. Recommended pressures were used in less than one-third of cases in all audit cycles, with no significant change throughout. More than 50% of respondents sized their tourniquet on 'whatever looked best fit'.

CONCLUSIONS

Despite tourniquet usage being part of the UK Trauma & Orthopaedic Surgery curriculum, this study is the first to highlight a lack of compliance with 'gold standard' guidelines and the need for increased training for staff to ensure patients are exposed to the safest possible environment. Although electronic proformas can aid recording of information, the limitation to change is cultural tradition and anecdotal experience.

Comparative value of dapagliflozin vs empagliflozin in patients with heart failure and preserved ejection fraction: A cost-effectiveness analysis

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) imposes a high disease burden on patients, primarily because of multimorbidity and frequent hospitalizations. Recently, the American College of Cardiology Expert Consensus recommended treating all patients diagnosed with HFpEF with a sodium-glucose cotransporter 2 inhibitor, such as dapagliflozin or empagliflozin, to reduce the risk of cardiovascular death and hospitalization and improve health status. However, managing HFpEF can be expensive, highlighting the need to assess therapeutic alternatives that can minimize health care costs while optimizing patient outcomes. OBJECTIVE: To compare the cost-effectiveness of dapagliflozin vs empagliflozin in managing patients with HFpEF from the US health care system perspective. METHODS: We developed a Markov model to simulate a cohort of patients with HFpEF (defined as having a left ventricular ejection fraction ≥ 50%) treated with dapagliflozin or empagliflozin. Transition probabilities between 3 health states (HFpEF, hospitalization for heart failure, and death), costs, and quality of life weight input variables were obtained from the literature. In the base-case analysis, we estimated total expected costs, quality-adjusted life-years (QALYs) gained, and the incremental cost-effectiveness ratio (ICER) over a lifetime horizon. All future expected costs and QALYs were discounted at the annual rate of 3%. We conducted sensitivity analyses to demonstrate the robustness of the cost-effectiveness model findings. RESULTS: Dapagliflozin had an incremental expected lifetime cost of $29,896 compared with empagliflozin, resulting in an ICER of $36,902/QALY. Value-based price threshold analysis suggested that for empagliflozin to be cost-effective, it would need a 29% discount on its annual price. In a probabilistic sensitivity analysis, dapagliflozin would be the most preferred cost-effective option at willingness-to-pay thresholds of $50,000/QALY about 72% of the time. CONCLUSIONS: This cost-effectiveness analysis showed that, from the US health care system perspective, dapagliflozin was more cost-effective than empagliflozin, and its uptake may enhance long-term outcomes in patients with HFpEF.

AB0762 METABOLIC SYNDROME IN EGYPTIAN PSORIATIC ARTHRITIS PATIENTS

Background:

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis affecting 20:30% of patients with skin Psoriasis (PsO). It is strongly associated with obesity, particularly excess visceral adiposity, which leads to insulin resistance, hyperglycemia, dyslipidemia, and hypertension (HTN).

All the previous findings are grouped in Metabolic Syndrome (MetS) which increase the risk of development of Type 2 diabetes mellitus (T2DM) by five folds and cardiovascular disease (CVD) by two folds.

Objectives:

The aim of this work was to define those who fulfill MetS criteria in PsA patients thus of greater risk to develop CVD and T2DM.

Methods:

Fifty PsA patients diagnosed according to the CASPAR criteria and 50 matched healthy controls were included in this study.

All patients were subjected to thorough clinical evaluation of the musculoskeletal system. The disease activity was assessed by DAPSA and BASDAI. Skin severity was assessed by the PASI. Disability assessment was done by the HAQ-DI. Laboratory investigations included: CRP, uric acid and diabetic profile (includingHOMA-IR) and lipid profile in patients and control subjects.

Subjects were defined as having MetS according to International Diabetes Federation (IDF) criteria:

Abdominal obesity was measured by Waist circumference (WC) for Egyptian cutoffs values (WC>100.5 cm in men and >96.25 cm in women).The subjects must have central obesity to identify MetS plus any two of the following four factors:

Results:

Metabolic syndrome was significantly higher among PsA patients than control group (42% Vs 16% respectively).

Regarding frequency of MetS components, obesity was the highest component among PsA patients (62%) as illustrated in Figure 1.

CRP mean level was significantly higher in PsA patients compared to control group with p <0.001*. CRP serum level showed a positive significant correlation with DAPSA score and HOMA-IR (P= 0.031, 0.002 respectively)

Correlations between MetS components and (disease activity, skin severity and physical function) are shown in Table 1.

Conclusion:

1-There is high frequency of MetS in PsA patients compared to control group.

2- Obesity and DMT2 were the most common components of MetS.

References:

[1]Eder L, Harvey P, Chandran V, Rosen CF, Dutz J, Elder JT, et al. Gaps in diagnosis and treatment of cardiovascular risk factors in patients with psoriatic disease: an international multicenter study. The Journal of rheumatology. 2018:jrheum. 170379.

[2]Alberti KGMM, Zimmet P, Shaw J. Metabolic syndrome—a new world-wide definition. A consensus statement from the international diabetes federation. Diabetic medicine. 2006;23(5):469-80.

Psoriatic ArthritisMetabolic syndromeWCBMITGHDLFBSHOMA-IRSystolic BPDiastolic BPDAPSArs-0.2330.0810.086-0.1160.2630.3870.136-0.170P0.3080.7280.7100.6160.2500.0830.5570.462BASDAIrs0.798*0.1520.060-0.110-0.424-0.2940.168-0.027P<0.001*0.5090.7980.6360.0550.1960.4670.906PASIrs0.435*0.2260.363-0.521*-0.276-0.253-0.054-0.060P0.049*0.3240.1060.015*0.2270.2680.8180.795HAQ-DIrs0.1890.1760.168-0.286-0.240-0.184-0.343-0.276P0.4130.4450.4660.2090.2950.4240.1280.225

Disclosure of Interests:

None declared

SURGE complex of Plasmodium falciparum in the rhoptry-neck (SURFIN4.2-RON4-GLURP) contributes to merozoite invasion

Plasmodium falciparum invasion into red blood cells (RBCs) is a complex process engaging proteins on the merozoite surface and those contained and sequentially released from the apical organelles (micronemes and rhoptries). Fundamental to invasion is the formation of a moving junction (MJ), a region of close apposition of the merozoite and the RBC plasma membranes, through which the merozoite draws itself before settling into a newly formed parasitophorous vacuole (PV). SURFIN4.2 was identified at the surface of the parasitized RBCs (pRBCs) but was also found apically associated with the merozoite. Using antibodies against the N-terminus of the protein we show the presence of SURFIN4.2 in the neck of the rhoptries, its secretion into the PV and shedding into the culture supernatant upon schizont rupture. Using immunoprecipitation followed by mass spectrometry we describe here a novel protein complex we have named SURGE where SURFIN4.2 forms interacts with the rhoptry neck protein 4 (RON4) and the Glutamate Rich Protein (GLURP). The N-terminal cysteine-rich-domain (CRD) of SURFIN4.2 mediates binding to the RBC membrane and its interaction with RON4 suggests its involvement in the contact between the merozoite apex and the RBC at the MJ. Supporting this suggestion, we also found that polyclonal antibodies to the extracellular domain (including the CRD) of SURFIN4.2 partially inhibit merozoite invasion. We propose that the formation of the SURGE complex participates in the establishment of parasite infection within the PV and the RBCs.

Ferroelectric switching of band alignments in LSMO/PZT/Co multiferroic tunnel junctions: an ab initio study

Band alignments in ferroelectric tunnel junctions (FTJs) are expected to play a critical role in determining the charge transport across the tunneling barrier. In general, however, the interface band discontinuities and their polarization dependence are not well known in these systems. Using a first-principles density-functional-theory approach, we explore the ferroelectric (FE) polarization dependence of the band alignments in [Formula: see text] (LSMO/PZT/Co) multiferroic tunnel junctions, for which recent experiments indicated an ON/OFF conductivity behavior upon switching the PZT FE polarization. Our results on the pseudomorphic defect-free LSMO/PZT/Co FTJs evidence a major FE switching effect on the band discontinuities at both interfaces. Based on the changes in the band alignments, we provide a possible explanation for the observed trends in the resistive switching.

Plasmodium falciparum merozoite surface protein 3: oligomerization, self-assembly, and heme complex formation

Merozoite surface protein 3 of Plasmodium falciparum, a 40-kDa protein that also binds heme, has been biophysically characterized for its tendency to form highly elongated oligomers. This study aims to systematically analyze the regions in MSP3 sequence involved in oligomerization and correlate its aggregation tendency with its high affinity for binding with heme. Through size exclusion chromatography, dynamic light scattering, and transmission electron microscopy, we have found that MSP3, previously known to form elongated oligomers, actually forms self-assembled filamentous structures that possess amyloid-like characteristics. By expressing different regions of MSP3, we observed that the previously described leucine zipper region at the C terminus of MSP3 may not be the only structural element responsible for oligomerization and that other peptide segments like MSP3(192-196) (YILGW) may also be required. MSP3 aggregates on incubation were transformed to long unbranched amyloid fibrils. Using immunostaining methods, we found that 5-15-μm-long fibrillar structures stained by anti-MSP3 antibodies were attached to the merozoite surface and also associated with erythrocyte membrane. We also found MSP3 to bind several molecules of heme by UV spectrophotometry, HPLC, and electrophoresis. This study suggested that its ability to bind heme is somehow related to its inherent characteristics to form oligomers. Moreover, heme interaction with a surface protein like MSP3, which does not participate in hemozoin formation, may suggest a protective role against the heme released from unprocessed hemoglobin released after schizont egress. These studies point to the other roles that MSP3 may play during the blood stages of the parasite, in addition to be an important vaccine candidate.

The fate of indefinite and low-grade dysplasia in ulcerative colitis and primary sclerosing cholangitis colitis before and after liver transplantation

BACKGROUND

Patients with primary sclerosing cholangitis (PSC) and ulcerative colitis (UC) are at an increased risk of colorectal neoplasia, but it is unknown if liver transplantation (LT) alters neoplasia progression.

AIM

To examine the natural history of indefinite dysplasia (IND) and low-grade dysplasia (LGD) that develop in patients with PSC-UC with and without LT.

METHODS

We performed a retrospective review of patients with PSC and UC evaluated at our institution between 1993 and 2011 who were diagnosed with IND or LGD before or after LT for PSC. The primary end point was neoplasia progression or persistent LGD.

RESULTS

Ninety-six patients (non-LT n = 63, LT n = 33) were examined. For the IND group, multifocal lesions were significantly associated with time to neoplasia progression [hazard ratio (HR), 3.5; 95% confidence interval (CI), 1.3-9.7], while 5-aminosalicylate (5-ASA) use was protective (HR, 0.2; 95% CI, 0.1-0.6). For patients with LGD, multifocal lesions were significantly associated with the primary end point (HR, 7.1; 95% CI, 1.7-28.3), while LT was protective (HR, 0.3; 95% CI, 0.1-0.9).

CONCLUSIONS

In PSC-UC patients with IND, 5-ASA use was associated with a decreased the risk of neoplasia progression, regardless of transplant status. In contrast, multifocal IND and LGD were associated with neoplasia progression or persistent LGD. Patients who developed LGD following LT for PSC were less likely to have progressive neoplasia or persistent LGD, compared with those who had not been transplanted.

Low admission serum albumin as prognostic determinant of 30-day case fatality and adverse functional outcome following acute ischemic stroke

Introduction

Over 80% of stroke deaths occur in low-income and middle-income regions of the world. Identification of predictors of mortality is vital so that prompt therapeutic measures could be instituted to improve outcome. Previous studies have identified factors such as stroke severity, stroke type, older age, impairment of consciousness and hyperglycaemia as predictors of mortality for acute stroke but mortality remain high among patients hospitalized for acute stroke. The study objective was to determine the association between admission serum albumin levels and short-term outcome following acute ischaemic stroke in Nigerians.

Methods

Consecutive first-ever acute ischaemic stroke patients were prospectively enrolled between February 2009 and May 2010. Stroke severity at presentation was determined using National Institute of Heath Stroke Score (NIHSS). Admission serum chemistry including albumin, were measured. Patients were then followed up for 30 days and outcome measures applied at the end of the study were 30-day mortality and functional outcome using the Modified Rankin Scale (MRS) and graded as favourable(MRS 0-3) or unfavourable(MRS 4-6). Relationship between serum albumin and stroke outcome was determined.

Results

75 acute stroke cases were studied. Mean age was 57.68 ± 12.4 years. Outcome was favourable in 48% while 30-day case fatality was 17.3%. The mean age (61.13 years) of those with poor outcome was significantly higher than those with favourable outcome. Mean serum albumin (3.03g/dL) of those with favourable outcome was also significantly higher than (2.08g/dL) of those with unfavourable outcome (p=0.0001). Patients that died had significantly lower serum albumin (1.66g/dl) than survivors (p=0.0001).Receiver operating characteristics curve for optimal cut off point of serum albumin to predict survival or death within 30 days revealed area under the cure (AUC) of 0.870, p-value 0.0001, 95% C/I=0.759-0.982. Serum albumin of 1.55g /dL has sensitivity of 100% and specificity of 61.5%. NIHSS and serum albumin were predictors of poor outcome using multiple regression.

Conclusion

Low admission serum albumin was an independent determinant of poor outcome.

Pyrano[4,3-b]quinolines library generation via iodocyclization and palladium-catalyzed coupling reactions

Synthesis of a 80-member library of novel pyrano[4,3-b]quinolines in solution-phase is reported. The key intermediate, 4-iodopyrano[4,3-b]quinolines were synthesized by the electrophilic iodocyclization of corresponding ortho-alkynyl aldehydes in good to excellent yields under mild reaction conditions. Subsequently a diverse set of libraries was generated by employing palladium-catalyzed Suzuki-Miyaura, Heck, and Sonogashira coupling reactions on 4-iodopyrano[4,3-b]quinolines. In this way, a series of structurally different and biologically interesting molecules were obtained. Some of the selected compounds were screened against 3D7 strains of Plasmodium falciparum for antimalarial activity. Suzuki coupling products 6{3} and 6{21} and Heck coupling product 8{12} exhibit promising antimalarial activity.

Preparation and in vitro evaluation of thiolated chitosan microparticles

The objective of this study was to prepare a microparticulate drug delivery system being based on a new thiomer, namely a chitosan 2-iminothiolane conjugate (chitosan-TBA conjugate). Due to thiol groups being immobilized on chitosan, chitosan-TBA conjugate exhibits improved mucoadhesive and permeation enhancing properties. Because of these features microparticulate drug delivery systems based on chitosan-TBA conjugate might be a promising tool for the non-invasive administration of hydrophilic macromolecular drugs. Chitosan-TBA conjugate microspheres were prepared by the emulsification/solvent evaporation method. Fluorescein-isothiocyanate labelled dextran (FITC-dextran) was chosen as a model hydrophilic drug. Microspheres have been characterized by morphological analysis, thiol group content, swelling behaviour, polymer degradation drug load determination, dissolution test and mucoadhesion studies. Results reported in this work demonstrated the possibility to obtain stable microspheres without cross-linking agents. Thiolated chitosan microspheres seem to be more stable in aqueous media with respect to unmodified chitosan. The degradability by lysozyme appears quite similar for both polymers, showing that chemical modification does not influence the biodegradable properties of chitosan. Microspheres were able to control the drug release for at least 1 h, exhibiting comparatively strong mucoadhesive properties. The chitosan-TBA conjugate microparticles remain on the mucosa in a 2.5-fold higher concentration with respect to unmodified chitosan microparticles. These data suggest that chitosan-TBA conjugate microspheres have the potential to be used as a mucoadhesive drug delivery system.

Prevalence and risk indicators for destructive periodontal diseases in 3 urban American minority populations

BACKGROUND, AIMS

Destructive periodontal diseases have been reported disproportionately more prevalent and severe in African-Americans relative to other American populations. Differences in subgingival microbiota and host immune response have also been reported for African-Americans, implying that risk factors for disease progression may also differ for these populations. Since it is not clear whether these differences are truly genetic or due to confounding variables such as social economic status, we examined a series of clinical, environmental, demographic, and microbiologic features associated with periodontal disease status in a group of 185 urban minority subjects resident within the greater New York metropolitan area.

METHODS

The study population consisted of 56 Asian-American, 71 African-American and 58 Hispanic subjects. Clinical data recorded included pocket depth, attachment level, gingival erythema, bleeding upon probing, suppuration, and the presence of supragingival plaque. Environmental and demographic data recorded included smoking history, years resident in the United States, whether the subject reported a private dentist and occupational status. Subgingival plaque was sampled from the mesial aspect of all teeth exclusive of third molars and the levels of 40 subgingival species enumerated using checkerboard DNA-DNA hybridization.

RESULTS

The African-American group had more missing teeth, deeper periodontal pocket depth and more attachment loss than the Asian-American or Hispanic groups. However, the African-American group were less likely to report having a private dentist, had a greater proportion of smokers and a greater proportion of unskilled individuals. The profile of subgingival species differed among the three ethnic/racial groups with A. actinomycetemcomitans, N. mucosa, S. noxia and T. socranskii significantly elevated in the Asian-American group and P. micros significantly elevated in the African-American group. When subset by occupational status, numbers of missing teeth, pocket depth, attachment level and prior disease activity were all found increased in the unskilled relative to the professional group. Local factors including the mean % of sites with plaque, marginal gingival erythema, bleeding upon probing and suppuration were also elevated in the unskilled group. The microbial profile differed among the 3 occupational groups with the unskilled group having elevated numbers of species associated with destructive periodontal diseases.

CONCLUSIONS

Although greater destructive periodontal disease prevalence and severity were found in the African-American group, these results suggest that environmental and demographic variables, such as occupational status, may have a greater influence on risk indicators associated with disease prevalence and progression in these populations.

Correlation between EBV DNA and rearrangement and expression of Bcl-2 gene in aggressive non-Hodgkin's lymphoma

Previous in vitro studies have shown that bcl-2 expression can be induced by transfection of Epstein-Barr virus (EBV)-negative non-Hodgkin's lymphoma (NHL) cell lines with EBV. This induced expression of bcl-2 is important for the long survival of EBV-positive cells and might be a first step in tumorigenesis. The purpose of the present study was to investigate the possibility of similar correlation between bcl-2 expression and EBV infection in vivo in a cohort of patients with aggressive NHL, who were uniformly evaluated and treated with effective chemotherapy. The 42 patients included were 25-65 years old. None had prior treatment, discordant lymphoma, or human immunodeficiency virus seropositivity. Fresh biopsied samples were obtained and stored frozen for analysis of bcl-2 gene rearrangement major break point and of EBV DNA by PCR. Bcl-2 protein expression was estimated by Western blot, and enzyme immunoassay. With a median follow-up of 30 months, overall survival (OS) and disease-free survival (DFS) were measured to determine the prognostic significance of these variables. Analyzable DNA was present in all samples, 24% demonstrating bcl-2 rearrangement and 33% showing EBV DNA. Patients with bcl-2 gene rearrangement tended to have shorter DFS, and OS than patients without translocation. Bcl-2 protein expression was not correlated to gene rearrangement and had no significant influence on survival. The presence of EBV DNA in NHL had no prognostic significance but was correlated to bcl-2 expression. EBV-positive tumors showed higher bcl-2 expression than EBV-negative tumors did. Our results suggest a role of EBV infection in inducing bcl-2 expression as a survival factor for EBV-positive cells.

Evaluation of serum laminin as a tumor marker in breast cancer

Laminin is a noncollagenous constituent of the extracellular matrix (basement membrane). Increased serum concentrations were recorded in patients with a variety of cancers. The clinical usefulness of serum laminin as a marker for breast cancer was investigated in 60 female patients with malignant breast tumors (30 metastatic, 30 non-metastatic). Subjectively healthy age-matched women (n = 30) served as a control group. Laminin was significantly higher in breast cancer patients than in normal controls. Serum laminin levels were also significantly higher in patients with metastasis than in those without metastasis. A positive correlation was observed between serum laminin and the breast cancer-associated antigen CA 15-3 in the tumor patients. The sensitivity and specificity values of laminin for cancer detection at the optimum decision level [mean + 2 SD (1.4 U/ml)] were 75% and 97% respectively, with a 98% positive predictive value, 66% negative predictive value, and 82% diagnostic efficiency. For the detection of metastasis, serum laminin exhibited 77% sensitivity and 100% specificity [best decision level: mean + 2 SD (1.9 U/ml)], with a 100% positive predictive value, 81% negative predictive value, and 88% diagnostic efficiency. The latter specificity and positive predictive value were superior to those obtained with serum CA 15-3. These results suggest that serum determination of laminin could be a useful diagnostic tool in breast cancer and a valuable parameter in the prediction of metastasis.

Modification of the expression of adenosine 3',5'-cyclic monophosphate-induced differentiated functions in neuroblastoma cells by beta-carotene and D-alpha-tocopheryl succinate

OBJECTIVE

The role of beta-carotene and vitamin E in modifying the effect of cell differentiating agent has not been studied. This study has investigated the effects of beta-carotene and d-alpha-tocopheryl succinate (alpha-TS) on adenosine 3',5'-cyclic monophosphate (cAMP) induced differentiated functions in murine neuroblastoma cells (NBP2) in culture.

METHODS

Prostaglandin E1 (PGE1), a stimulator of adenylate cyclase, and 4-(3-butoxy-4-methoxy-benzyl)-2-imidazolidinone (R020-1724), an inhibitor of cyclic nucleotide phosphodiesterase, were used to induce differentiation in NB cells.

RESULTS

Both beta-carotene and alpha-TS markedly enhanced the level of morphologic differentiation (neurite formation) induced by both PGE1 and R020-1724. However, beta-carotene and alpha-TS by themselves were ineffective. These vitamins increased tyrosine hydroxylase (TH) activity. However, beta-carotene did not significantly affect PGE1- and R020-1724-stimulated rise in TH activity. alpha-TS at a higher concentration inhibited PGE1- and R020-1724-stimulated increase in TH activity. None of the above treatments affected basal choline acetyltransferase (ChAT) activity. beta-carotene and alpha-TS caused a transient increase in cAMP level, and they also enhanced the effect of PGE1 and R020-1724 on cAMP level in a transient manner.

CONCLUSION

These results suggest that beta-carotene and alpha-TS modify the effects of cAMP stimulating agents on differentiation of NB cells in culture.

Cloning and sequence analysis of the X-prolyl-dipeptidyl-aminopeptidase gene (pepX) from Lactobacillus delbrückii ssp. lactis DSM7290

Lactobacillus delbrückii ssp. lactis DSM7290 possesses an X-prolyl-dipeptidyl-aminopeptidase, designated PepX, which catalyses the hydrolytic removal of N-terminal dipeptidyl residues from peptides containing proline in the penultimate position. Using the specific substrate L-Ala-L-Pro-p-nitroanilide, PepX was purified by a four-step procedure including ammonium sulphate fractionation, hydrophobic interaction chromatography, ion exchange chromatography, and affinity chromatography. The N-terminus of the purified protein was sequenced. Screening of a gene library of chromosomal Lactobacillus delbrückii ssp. lactis DSM7290 DNA in the low-copy-number vector pLG339 resulted in the identification of the pepX gene in Escherichia coli using a specific plate assay with Gly-L-Pro-beta-naphthylamide as substrate. Nucleotide sequence analysis revealed an open reading frame of 2376 bp, coding for a protein of 792 amino acids with a molecular mass of 88449 Da.