The benefits of index telephone consultations in patients referred on the two-week wait colorectal cancer pathway.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic led to hospitals in the UK substituting face-to-face (FtF) clinics with virtual clinic (VC) appointments. We evaluated the use of virtual two-week wait (2-ww) lower gastrointestinal (LGI) clinic appointments, conducted using telephone calls at a district general hospital in England. METHODS: Patients undergoing index outpatient 2-ww LGI clinic assessment between 1 June 2019 and 31 October 2019 (FtF group) and 1 June 2020 and 31 October 2020 (VC group) were identified. Relevant data were obtained using electronic patient records. Compliance with national cancer waiting time targets was assessed. Environmental and financial impact analyses were performed. RESULTS: In total, 1,531 patients were analysed (median age=70, male=852, 55.6%). Of these, 757 (49.4%) were assessed virtually via telephone; the remainder were seen FtF (n=774, 50.6%). Ninety-two (6%, VC=44, FtF=48) patients had malignant pathology and 64 (4.2%) had colorectal cancer (CRC); of these, 46 (71.9%, VC=26, FtF=20) underwent treatment with curative intent. The median waiting times to index appointment, investigation and diagnosis were significantly lower following VC assessment (p<0.001). The cancer detection rates (p=0.749), treatments received (p=0.785) and median time to index treatment for CRC patients (p=0.156) were similar. A significantly higher proportion of patients were seen within two weeks of referral in the VC group (p<0.001). VC appointments saved patients a total of 9,288 miles, 0.7 metric tonnes of CO2 emissions and £7,482.97. Taxpayers saved £80,242.00 from VCs. No formal complaints were received from patients or staff in the VC group. CONCLUSION: Virtual 2-ww LGI clinics were effective, safe and were associated with tangible environmental and financial benefits.

A retrospective audit of the timescales involved in the diagnosis and management of suspected Achilles tendon ruptures at a single National Health Service trust: A quality service improvement and redesign project.

Introduction: The Achilles tendon is the most frequently ruptured tendon. Prompt diagnosis of this injury ensures optimal management decisions are instituted early ensuring the best outcome and patient experience, at minimal cost to the United Kingdom National Health Service. Despite this, regional and national variations to diagnosis and management exist, with anecdotal evidence of inefficiencies in the local patient pathway. To explore this further, a retrospective departmental audit of timescales from presentation to ultrasound diagnosis and definitive treatment decision was undertaken. Methods: All suspected Achilles tendon ruptures in 2018 were identified through electronic and written patient records, and information on timescales involved in the diagnosis and management of each compiled. Descriptive statistics were used to map each step of the pathway and timescales involved, with performance assessed against local departmental standards and the Swansea Morriston Achilles Rupture Treatment (SMART) protocol. Results: In total, 119 patients were identified, of which 113 received an ultrasound examination. Local departmental standards were met in the majority of cases, with 78% (n = 88) diagnosed by ultrasound within one week of the request and 83% (n = 91) given a treatment decision within two weeks of presentation. However, this was suboptimal when compared with timeframes utilised for developing the SMART protocol, with only 7% (n = 8) scanned within 48 hours of presentation. Conclusions: Key areas of the patient pathway were identified for quality service improvement and redesign, with multidisciplinary discussion resulting in the development of a revised patient pathway which expedites diagnosis and treatment for these injuries.

The effect of nitroglycerin ointment on great saphenous vein targeted venous access site diameter with endovenous laser treatment.

OBJECTIVES: To assess the effect of topically applied nitroglycerin (NTG) ointment (2%) on preoperative targeted venous access site great saphenous vein (GSV) diameter in patients undergoing endovenous laser treatment (ELT). METHODS: In this double-blinded randomized study design, 75 patients received either (A) treadmill ambulation only, (B) topically applied NTG ointment only, or (C) topically applied NTG ointment + treadmill ambulation. Targeted venous access vein diameters were measured before therapeutic intervention and then repeated after approximately 30 min following pretreatment intervention. Presence of venospasm and the number of ultrasound-guided venous access attempts during each ELT procedure were assessed during the study. RESULTS: The mean pretreatment vein diameter was 2.6 mm (range 0.9-4.9 mm). The post-treatment percentage change in vein diameter for group A (treadmill ambulation only) was +2.7% (P = 0.403), whereas group B (NTG only) and group C (NTG + treadmill ambulation) demonstrated significant venodilatation of +69.0% (P < 0.0001) and +51.7% (P < 0.0001), respectively. Statistical analysis of variances and multivariate linear regression model revealed topically applied NTG ointment and 'C' classification of clinical, aetiological, anatomical and pathological elements (CEAP) were each significant predictors for venodilatation percentage change (P < 0.001 and = 0.028, respectively). CONCLUSION: Pretreatment with topically applied NTG ointment (2%) produced a statistically significant, as well as subjective clinically significant venodilatation change in the targeted venous access site diameter of patients undergoing ELT of the GSV in this study.

The kinetic properties and sensitivities to inhibitors of lactate dehydrogenases (LDH1 and LDH2) from Toxoplasma gondii: comparisons with pLDH from Plasmodium falciparum.

Toxoplasma gondii differentially expresses two forms of lactate dehydrogenase in tachyzoites and bradyzoites, respectively, designated LDH1 and LDH2. Previously it was demonstrated that LDH1 and LDH2 share a unique structural feature with LDH from the malarial parasite Plasmodium falciparum (pLDH), namely, the addition of a five-amino acid insert into the substrate specificity loops. pLDH exhibits a number of kinetic properties that previously were thought to be unique to pLDH. In the present study, kinetic properties of LDH1 and LDH2 were compared with those of pLDH. LDH1 and LDH2 exhibit broader substrate specificity than pLDH. For both LDH1 and LDH2, 3-phenylpyruvate is an excellent substrate. For LDH2, 3-phenylpyruvate is a better substrate even than pyruvate. By comparison, pLDH does not utilize 3-phenylpyruvate. Both LDH1 and LDH2 can utilize the NAD analog 3-acetylpyridine adenine dinucleotide (APAD) efficiently, similar to pLDH. LDH1 and LDH2 are inhibited competitively by a range of compounds that also inhibit pLDH, including gossypol and derivatives, dihydroxynaphthoic acids, and N-substituted oxamic acids. The lack of substrate inhibition observed with pLDH is also observed with LDH2. By comparison, LDH1 differs from LDH2 in exhibiting substrate inhibition in spite of an identical residue (M163) at a cofactor binding site that is thought to be critical for production of substrate inhibition. For gossypol and gossylic iminolactone, but not the other gossypol derivatives tested, the in vitro inhibition of T. gondii LDH activity correlated with specific inhibition of T. gondii tachyzoite growth in fibroblast cultures.

Simple and efficient method for measuring anti-toxoplasma immunoglobulin antibodies in human sera using complement-mediated lysis of transgenic tachyzoites expressing beta-galactosidase.

A simple and efficient method using transgenic Toxoplasma gondii tachyzoites expressing beta-galactosidase was developed for detection of specific antibodies against the parasite in sera of patients. The titers obtained with the new test were similar to those obtained with the Sabin-Feldman dye test run in parallel. Although significant changes in endpoint titers were not observed when sera drawn sequentially at 2- to 3-week intervals were tested with both procedures, apparent differences in antibody affinity were observed with the new test which were not perceptible with the Sabin-Feldman dye test. Like the Sabin-Feldman dye test, the new test is based on complement lysis of tachyzoites, but it is much easier to perform and the reaction is read colorimetrically instead of visually.

Directing differentiation in Theileria annulata: old methods and new possibilities for control of apicomplexan parasites.

Apicomplexan parasites are major pathogens of humans and domesticated animals. The ability of these organisms to evade the host immune response and the emergence of drug-resistant parasites indicates a need for the identification of novel control strategies. Ideally, selected targets should be shared by a range of apicomplexans and fundamental to parasite biology. One process of apicomplexan biology which may provide this type of target is the molecular regulation of stage differentiation. This paper has reviewed studies carried out on differentiation of Theileria annulata and has highlighted general similarities with other apicomplexan differentiation steps. Similarities include asynchrony of differentiation, the loss (attenuation) of differentiation potential and an association between reduced proliferation and differentiation. In addition, novel data are presented assessing a possible role for a signal transduction mechanism or a direct involvement of classical heat-shock polypeptides in regulating differentiation of T. annulata in vitro. These studies, and previously published data, have led to the postulation that progression to the next stage of the life-cycle can be predetermined and involves the attainment of a quantitative threshold by regulators of gene expression. A modification of this model takes into account that for certain in-vitro systems, or differentiation steps in vivo, the process has to be initiated by alteration of the extracellular environment. Work which has shown that the time taken to achieve differentiation can be increased or decreased is also outlined. The ability to change the timing of differentiation suggests that the associated regulatory mechanism could be manipulated directly to significantly influence the outcome of an apicomplexan infection. The observation that a number of existing drugs and control strategies may exert their protective effect by altering differentiation potential supports this possibility.

Modulation of growth relative to division regulates expression of a Theileria annulata infection associated antigen in HL-60 cells differentiating towards granulocytes.

The protozoan parasite Theileria annulata has the ability to immortalise the bovine leukocyte in which it resides. Immortalisation is known to be associated with a number of molecular and antigenic alterations to the host cell. In this study cells of related lineage were compared with T. annulata infected cells, using a monoclonal antibody which detects an infection associated glycoprotein on the host cell surface. The results show that this antibody recognises a 160 kDa antigen in HL-60 cells, and that expression of this antigen is up-regulated as cells are induced to differentiate towards granulocytes, but not macrophages. Up-regulation was observed to proceed in a quantitative manner, with progression through an intermediate phase, before full antigen expression and granulocyte formation was observed. Limited incubation with inducer (DMSO) for 18 h indicated that intermediate cells could revert to negative cells, while longer exposure resulted in conversion to high level antigen expression and a commitment to differentiate. Alteration of cell culture conditions and modulation of division (DNA synthesis) relative to growth (protein synthesis) by incubation in aphidicolin resulted in an increase in the number of cells expressing antigen at both the intermediate level and the level associated with commitment. Based on these results and related studies we present a model which proposes that differentiation is initiated, and then progresses to a quantitative commitment threshold, by altering the level of key regulators of gene expression relative to their DNA templates.

Identification and preliminary characterization of temperature-sensitive mutations affecting HlyB, the translocator required for the secretion of haemolysin (HlyA) from Escherichia coli.

We have carried out a genetic analysis of Escherichia coli HlyB using in vitro(hydroxylamine) mutagenesis and regionally directed mutagenesis. From random mutagenesis, three mutants, temperature sensitive (Ts) for secretion, were isolated and the DNA sequenced: Gly10Arg close to the N-terminus, Gly408Asp in a highly conserved small periplasmic loop region PIV, and Pro624Leu in another highly conserved region, within the ATP-binding region. Despite the Ts character of the Gly10 substitution, a derivative of HlyB, in which the first 25 amino acids were replaced by 21 amino acids of the lambda Cro protein, was still active in secretion of HlyA. This indicates that this region of HlyB is dispensable for function. Interestingly, the Gly408Asp substitution was toxic at high temperature and this is the first reported example of a conditional lethal mutation in HlyB. We have isolated 4 additional mutations in PIV by directed mutagenesis, giving a total of 5 out of 12 residues substituted in this region, with 4 mutations rendering HlyB defective in secretion. The Pro624 mutation, close to the Walker B-site for ATP binding in the cytoplasmic domain is identical to a mutation in HisP that leads to uncoupling of ATP hydrolysis from the transport of histidine. The expression of a fully functional haemolysin translocation system comprising HlyC,A,B and D increases the sensitivity of E. coli to vancomycin 2.5-fold, compared with cells expressing HlyB and HlyD alone. Thus, active translocation of HlyA renders the cells hyperpermeable to the drug. Mutations in hlyB affecting secretion could be assigned to two classes: those that restore the level of vancomycin resistance to that of E. coli not secreting HlyA and those that still confer hypersensitivity to the drug in the presence of HlyA. We propose that mutations that promote vancomycin resistance will include mutations affecting initial recognition of the secretion signal and therefore activation of a functional transport channel. Mutations that do not alter HlyA-dependent vancomycin sensitivity may, in contrast, affect later steps in the transport process.