Factors influencing nodal yield in neck dissections for head and neck malignancies

OBJECTIVE

A standard lateral neck dissection should yield at least 18 lymph nodes. The goal of the present study was to examine what factors might influence the number of lymph nodes retrieved during a neck dissection.

METHODS

This was a retrospective cohort study in a tertiary academic referral centre for head and neck oncology. Two hundred and nineteen consecutive neck dissections were examined. Age of the patient and primary site were recorded, along with tumour histology, previous radiotherapy and final nodal count.

RESULTS

The mean age was 62.2 ± 13.0 years. The most common primary site was the oral cavity (38.8 per cent). The mean number of lymph nodes was 30.63 ± 13.9. In total, 17.8 per cent had undergone previous radiotherapy. The mean number of lymph nodes was 33.26 ± 13.27 in patients with no previous radiation exposure and 18.47 ± 9.46 in those with previous radiation treatment.

CONCLUSION

Lymph node yield from a neck dissection is likely multi-factorial in nature. Previous radiotherapy, the only significant contributor, led to a mean reduction of lymph node yield from 33.3 to 18.5.

Provision of smoking cessation support for patients following a diagnosis of cancer in Ireland

There is growing evidence that smoking cessation (SC) improves outcomes following diagnosis of cancer. Notwithstanding adverse outcomes, a significant number of those diagnosed with cancer continue to smoke. Our objective was to document the SC services provided for patients with cancer by specialist adult cancer hospitals across Ireland, a country with a stated tobacco endgame goal. A cross-sectional survey based on recent national clinical guidelines was used to determine SC care delivery across eight adult cancer specialist hospitals, and one specialist radiotherapy centre. Qualtrics was used. The response rate was 88.9% with data reported from seven cancer hospitals and one specialist radiotherapy centre, all indicating they had some SC related provision (100%). Stop smoking medications were provided to cancer inpatients in two hospitals, at outpatients and attending day ward services in one hospital. Smokers with cancer were referred automatically to the SC service in two hospitals at diagnosis. While stop smoking medications were available 24 h a day in five hospitals, most did not stock all three (Nicotine Replacement Therapy, Bupropion, Varenicline). One hospital advised they had data on uptake of SC services for smokers with cancer but were unable to provide detail. There is considerable variation in SC information and services provided to cancer patients across adult cancer specialist centres in Ireland, reflecting the suboptimal practice of smoking cessation for patients with cancer found in the limited international audits. Such audits are essential to demonstrate service gaps and provide a baseline for service improvement.

Smoking cessation for cancer patients through the lens of cancer specialists: challenges & solutions

Background

The benefits of smoking cessation (SC) for cancer patients are widely recognised. However, there has been a limited emphasis on SC in this context and it continues to be a challenge for cancer patients. As part of a larger feasibility study aiming to develop a structured SC pathway for cancer patients in Ireland, this qualitative study explored the SC practices, experiences and opinions of oncology healthcare professionals (HCPs).

Methods

Semi-structured interviews were conducted with 18 HCPs from lung, breast, cervical, head and neck and general oncology, across 4 specialist adult cancer hospitals in Ireland. Interview transcripts were analysed using thematic analysis.

Results

Four key themes emerged:

(1) Frequently ask and advise but infrequently assist: most HCPs ask about smoking and many advise about available supports, but few refer patients to SC services. Where offered, referrals were to hospital SC services and/or nicotine replacement therapy was prescribed; no HCP prescribed varenicline or bupropion. Barriers included lack of time, ill-defined referral pathways and lack of knowledge.

(2) Increased willingness but differing ability to quit: most patients were interested in quitting post diagnosis and had varying support needs, linked to cancer stage, social circumstances and stress levels.

(3) Need for an integrated or parallel service: all HCPs suggested that a structured and defined referral pathway will facilitate SC.

(4) Motivational counselling and pharmacotherapy combination: many HCPs suggested face to face as the best mode of intervention initially, with regular follow ups and ongoing support virtually, started pre-treatment, with an empathetic and empowering approach with provision of both motivational counselling and SC pharmacotherapy.

Conclusions

Smoking post cancer diagnosis has serious implications for cancer treatment and prognosis but is frequently overlooked. These findings will inform the design of a SC pathway for cancer patients.

Key messages

• Despite increased willingness to quit, there is inadequate and inconsistent SC support provision for cancer patients.

• Tailored SC support should be an integral part of comprehensive cancer care.

Impact of antihypertensive medication regimens on blood pressure control in individuals with established coronary heart disease

Background and purpose

Hypertension is a major risk factor for coronary heart disease (CHD) development and progression, with pharmacological control of blood pressure reducing the risk of CHD events and death [1].

Treatment and control of blood pressure in CHD is suboptimal, with many patients failing to achieve guideline-directed targets [1,2]. This study aims to assess the relationship between antihypertensive medication regimens and blood pressure control in patients with hypertension and established coronary heart disease.

Methods

The iASPIRE study recently evaluated secondary prevention in an Irish cohort with coronary heart disease [2]. Based on a method used in a similar study [3], we calculated the average percentage daily dose of each prescribed antihypertensive agent. We then assessed the relationship between dose and number of antihypertensive agents with blood pressure control.

Results

540 (75.5%) of iASPIRE participants had an underlying diagnosis of hypertension, and at the study examination, 56% of these had a blood pressure ≥140/90 mmHg, while 83% had a blood pressure ≥130/80 mmHg. The median number of antihypertensive agents prescribed was 2 (IQR 1–2), with 88% of those with hypertension on at least one blood pressure medication. In participants with hypertension on treatment, the median percentage daily medication dose was 29% (IQR 14–50). After adjustment for age and sex, the addition of further antihypertensive medications increased the odds of achieving a blood pressure target of <130/80 mmHg (OR 1.3, 95% CI 1.07–1.69, p=0.012). The average percentage daily dose of each antihypertensive agent was lower in both participants with a medication-controlled blood pressure of <130/80 mmHg and <140/90 mmHg compared to those without blood pressure control (30% versus 37% p=0.006 and 33% versus 38% p=0.028 respectively).

Conclusion

Many patients with hypertension and coronary heart disease currently fail to achieve blood pressure control. This analysis found that an increasing number of antihypertensive medications but not increasing dose was associated with better blood pressure control. Combination therapy is superior to sequential monotherapy in the treatment of hypertension [1], and an approach that emphasises the initiation of several antihypertensive agents would likely lead to better blood pressure control in individuals with coronary heart disease.

Funding Acknowledgement

Type of funding sources: None.

The demographic, psychosocial and clinical characteristics associated with cardiac risk factor control: an analysis of secondary prevention in adults with established coronary heart disease

Funding Acknowledgements

Type of funding sources: None.

Background and Purpose

Achieving risk factor (RF) control in patients with established coronary heart disease (CHD) reduces the risk of CHD events.(1) Cross-sectional studies have shown that the implementation of current prevention guidelines is poor, with most patients failing to meet recommended targets.(2,3) This study aims to identify demographic, psychosocial and clinical characteristics associated with the non-achievement of RF targets in a population with CHD.

Methods

In this post-hoc cross-sectional analysis, multivariable logistic regression identified characteristics significantly associated with poor RF control in participants of the iASPIRE study which recently assessed secondary CHD prevention in Ireland.

Results

An unhealthy diet (Odds Ratio [OR] 1.6, 95% CI 1.1-2.4, p=0.015), male sex (OR 1.8, 95% CI 1.2-2.8, p=0.007) and type of acute coronary syndrome event (OR 0.6, 95% CI 0.4-0.9, p=0.012) were associated with failure to achieve blood pressure recommendations. Female sex (OR 2.3, 95% CI 1.4-3.8, p=0.002), lack of high-intensity statin (OR 2.4, 95% CI 1.5-3.8, p<0.001) and recurrent hospitalisation for CHD (OR 1.9, 95% CI 1.3-2.8, p=0.001) were associated with poor LDL-C control. Decreasing age (OR 0.9, 95% CI 0.9-1.0, p=0.018), marriage (OR 4.3, 95% CI 1.5-12.1, p=0.007) and insulin use (OR 9.7, 95% CI 1.9-50.4, p=0.007) were associated with a HbA1c of ≥53mmol/mol. The absence of a longstanding illness or disability and decreasing resting heart rate were associated with composite RF control.

Conclusion

Several demographic, psychosocial and clinical characteristics are associated with achieving guideline-recommended RF targets. These findings will support the development of targeted solutions that will improve guideline implementation and the practice of CHD prevention in a high-risk population.

Bempedoic acid and PCSK9 inhibitor eligibility in a contemporary population with atherosclerotic cardiovascular disease

Funding Acknowledgements

Type of funding sources: None.

Background and Purpose

The reduction of low-density lipoprotein cholesterol (LDL-C) in patients with established coronary heart disease (CHD) reduces the risk of atherosclerotic cardiovascular disease (ASCVD) events.(1) Many CHD patients fail to achieve guideline-recommended LDL-C targets without prohibitively expensive proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9 inhibitors).(2, 3, 4) This study aims to assess the impact that bempedoic acid may have on PCSK9 inhibitor eligibility in a population with CHD and ascertain whether its universal adoption would lead to overall cost-savings and a cost-effective reduction in ASCVD events.

Methods and Results

This retrospective analysis included 635 participants from the iASPIRE study, which recently assessed secondary prevention in an Irish cohort of CHD patients. We applied the 2019 ESC/EAS dyslipidaemia guideline LDL-C target of <1.4mmol/L and simulated the average treatment effect of improved lipid-lowering therapy with statins, ezetimibe and bempedoic acid. 86.3% of iASPIRE participants did not have LDL-C control and qualified for treatment intensification. Optimisation of statin therapy would allow 24.4% of patients to achieve their LDL-C goal, while the addition of ezetimibe would improve this to 55.7% leaving 44.3% eligible for a PCSK9 inhibitor. Utilising bempedoic acid would further reduce the proportion eligible to 18.7%. Based on current market prices and the universal application of ESC/EAS recommendations,(1, 5) the adoption of bempedoic acid would reduce the annual treatment costs associated with PCSK9 inhibitor use by almost 50% and result in cost savings per prevented CVD event.

Conclusions

The vast majority of CHD patients currently fail to achieve the recommended LDL-C target in everyday clinical practice. Ezetimibe and optimised statin therapy would enable most patients to meet their LDL-C goal. Employing bempedoic acid in patients with poor LDL-C control would significantly reduce the requirement for PCSK9 inhibitors and lead to cost savings per prevented CVD event.

Oro-Naso-Sino-Orbital-Cutaneous Fistula From Prolonged Cocaine Use

Presentation We present the case of a 48-year-old man with nasal cellulitis and subsequent oro-naso-sino-orbital-cutaneous fistula from prolonged cocaine use. Diagnosis Initial laboratory investigations reported a raised white cell count (WBC) and C-Reactive Protein (CRP) and subsequently a positive atypical anti-neutrophil cytoplasm antibodies (ANCA) and positive anti-proteinase (PR3). Perihilar lung nodularity on chest imaging raised the possibility of a systemic autoimmune response. His urinalysis was positive for cocaine. Treatment He was commenced on Augmentin, Amphotericin B and Prednisolone. An obturator was created to manage the oro-nasal fistula. A subsequent naso-cutaneous defect was re-approximated. Daily nasal saline douche and abstinence of cocaine were recommended. Discussion Cocaine use in the community is rising and poses a challenge to multiple facets of our health care system.

Mortality and long-term outcomes of palliative inotropes in ischemic and non-ischemic cardiomyopathy

Background

Palliative inotropes are frequently utilized for symptom management in patients with end stage heart failure who are unable to undergo durable advanced heart failure therapies. With the advent of improved medical management and early intervention, palliative inotropes may allow for improved patient outcomes than seen previously. In this study, we aim to investigate the survival and outcomes of palliative inotrope therapy and its impacts on ischemic versus non-ischemic cardiomyopathy.

Methods

We retrospectively analyzed 220 patients with American Heart Association Stage D heart failure who were discharged with palliative inotrope therapy after January 1, 2010. Patients who underwent mechanical circulatory support (MCS) or those who underwent heart transplant were excluded. Those with a history of coronary artery disease, myocardial infarction, history of percutaneous intervention, or coronary artery bypass grafting were assigned to ischemic cardiomyopathy (ICM), while patients without these findings were assigned to non-ischemic cardiomyopathy (NICM). Statistical analysis was completed using Chi-Square and Student's t-tests, wherein p<0.05 was considered statistically significant.

Results

Of the 220 patients, 87 had NICM as opposed to 133 with ICM. Mean age was found to be higher among patients with ICM (70 [62–79]) compared to NICM (65 [55–72], p-value <0.01). No significant difference was seen in total days on inotrope therapy (p=0.6). While more patients in both groups were placed on milrinone as opposed to dobutamine, there was no difference between patients with ischemic and NICM (p=0.66 and 0.51 respectively). Although a greater number of patients with NICM had been lost to follow up, admitted to hospice, or expired at 2 years (p<0.01), survival at 3 months, 1 year, and 2 years showed no difference between both groups. No difference was seen in number of hospitalizations or clinic visits in one year. Both groups had similar complication rates with intravenous-access related PICC line infections and new arrhythmias. (See Table).

Conclusion

Despite more frequent use of durable mechanical support devices, many patients who are deemed unsuitable for invasive measures are treated with palliative inotrope therapy. We have found that there is no significant difference in survival, complications, and outcomes of patients on palliative inotropes among ischemic and NICM. These findings show the versatility of palliative inotrope therapy in end stage heart failure. Further studies with larger populations need to be evaluated.

Funding Acknowledgement

Type of funding sources: None.

Title: Characterizing environmental stress responses of aposymbiotic Astrangia poculata to divergent thermal challenges

Anthropogenic climate change threatens corals globally and both high and low temperatures are known to induce coral bleaching. However, coral stress responses across wide thermal breadths remain understudied. Disentangling the role of symbiosis on the stress response in obligately symbiotic corals is challenging because this response is inherently coupled with nutritional stress. Here, we leverage aposymbiotic colonies of the facultatively symbiotic coral, Astrangia poculata, which lives naturally with and without its algal symbionts, to examine how broad thermal challenges influence coral hosts in the absence of symbiosis. A. poculata were collected from their northern range limit and thermally challenged in two independent 16-day common garden experiments (heat and cold challenge) and behavioral responses to food stimuli and genome-wide gene expression profiling (TagSeq) were performed. Both thermal challenges elicited significant reductions in polyp extension. However, there were five times as many differentially expressed genes (DEGs) under cold challenge compared to heat challenge. Despite an overall stronger response to cold challenge, there was significant overlap in DEGs between thermal challenges. We contrasted these responses to a previously identified module of genes associated with the environmental stress response (ESR) in tropical reef-building corals. Cold challenged corals exhibited a pattern consistent with more severe stressors while the heat challenge response was consistent with lower intensity stressors. Given that these responses were observed in aposymbiotic colonies, many genes previously implicated in ESRs in tropical symbiotic species may represent the coral host's stress response in or out of symbiosis.

Left ventricular pseudoaneurysm: an inadvertent consequence of COVID-19-a case report

Background

Left ventricular pseudoaneurysm (LVP) is an uncommon but serious mechanical complication of acute myocardial infarction (AMI). The immediate medical complications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are well recognized, but its indirect effect on patients and healthcare systems is potentially less perceivable.

Case summary

In this report, a 72-year-old man who was anxious about attending hospital during the SARS-CoV-2 pandemic was eventually found to have a total right coronary artery occlusion after a delayed emergency department presentation. He ultimately developed severe symptomatic heart failure and cardiac magnetic resonance imaging (CMR) revealed that a large LVP with concomitant severe ischaemic mitral regurgitation had evolved from his infarct. The patient was successfully discharged home after the surgical replacement of his mitral valve and repair of his LVP.

Discussion

This case highlights a salient downstream effect of Coronavirus disease 2019 (COVID-19): the delay in presentation, diagnosis, and management of common treatable conditions such as AMI. It also underscores the importance of non-invasive multimodal imaging on the timely identification of the mechanical complications of AMI. In particular, CMR can play a crucial role in the characterization and management of LVP.

P3: CASE-CONTROL STUDY OF SEXUAL BEHAVIOUR IN HPV-POSITIVE ORAL CAVITY AND OROPHARYNGEAL CANCER

Introduction

HPV infection is recognised as the main aetiological factor responsible for the increased incidence of oropharyngeal squamous cell carcinomas (OPSCC). Currently the epidemiology of oral HPV infection and OPSCC is poorly understood. In this study we aim to define the relationship between sexual behaviours and HPV-positive OPSCC.

Method

We performed a hospital-based, case-control study of 30 patients with HPV-positive and 30 patients with HPV-negative newly diagnosed oral cavity and OPSCC. The participants underwent questionnaire based interviews investigating variables such as age, gender, tobacco use, alcohol intake, and sexual behaviour.

Result

Subjects in the HPV-positive tumour subgroup had significantly less tobacco use then their HPV-negative counterparts (odds ratio, 0.92, 95% CI 0.9-1.17). A history of oral sexual activity was significantly more likely in the HPV-positive tumour subgroup (odds ratio, 5.23, 95% CI, 1.66-16.51), however this association did not remain significant when adjusted for age, gender, smoking and alcohol consumption. Similarly, there was significantly less alcohol consumption overall in the HPV-positive tumour subgroup (odds ratio, 0.107, 95% CI 0.96-1.01), but this association was no longer significant when adjusted for covariables.

Conclusion

Significantly less smoking was prevalent in patients with HPV-positive OPSCC. Although patients with HPV-positive tumours had less alcohol consumption and a stronger history of oral sexual activity overall, greater numbers are required in order to show a significant association. This further supports the known association between HPV-infection and OPSCC and the department of health's decision to commence vaccination of boys before the onset of sexual activity.

Take-home message

HPV-positive oropharyngeal cancer can develop without exposure to established risk factors such as tobacco use or excessive alcohol consumption. This change in pathogenesis should lead a change in how we prevent and manage the disease.

Tracheostomy stomal seeding following oral cavity resection

BACKGROUND

Tracheal stoma recurrence following oral cavity surgery is exceedingly rare. Although several different mechanisms for this have been described, the pathogenesis still remains uncertain.

METHODS

We present the case of a gentleman who presented 6-months following oral cavity SCC resection with a large fungating mass at his previous tracheostomy site, and also review the reported literature on this rare phenomenon.

RESULTS

Four weeks after diagnosis of his recurrence he underwent a total laryngectomy, wide-local skin excision and reconstruction with a pectoralis major pedicled flap. He recovered well initially following his operation, however unfortunately contracted nosocomial SARS-Cov2 and succumbed from respiratory complications during his post-operative recovery.

CONCLUSION

Stomal recurrence after temporary tracheostomy for oral cavity malignancies are very rare. Previously reported management of these can vary from surgical to palliative treatment. Methods to prevent these include delaying tracheostomy until after surgical resection, packing the pharynx during resection and adjuvant radiotherapy.

Targeting Lifestyle Behavior to Improve Brain Health: User-Experiences of an Online Program for Individuals with Subjective Cognitive Decline

BACKGROUND

Online programs targeting lifestyle have the potential to benefit brain health. We aimed to develop such a program for individuals with subjective cognitive decline (SCD). These individuals were reported to be at increased risk for dementia, and report both an intrinsic need for brain health information and motivation to participate in prevention strategies. Co-creation and user-evaluation benefits the adherence to and acceptance of online programs. Previously, we developed a prototype of the online program in co-creation with the users .

OBJECTIVES

We now aimed to evaluate the user-experiences of our online lifestyle program for brain health.

DESIGN

30-day user test; multi-method.

SETTING

Participants were recruited in a memory clinic and (online) research registries in the Netherlands (Alzheimer Center Amsterdam) and Germany (Center for memory disorders, Cologne).

PARTICIPANTS

Individuals with SCD (N=137, 65±9y, 57% female).

MEASUREMENTS

We assessed user-experiences quantitatively with rating daily advices and usefulness, satisfaction and ease of use questionnaires as well as qualitatively using telephone interviews.

RESULTS

Quantitative data showed that daily advices were rated moderately useful (3.5 ±1.5, range 1-5 points). Participants (n=101, 78%) gave moderate ratings on the programs' usability (3.7±1.3, max 7), ease of learning (3.6±1.9) and satisfaction (4.0±1.5), and marginal ratings on the overall usability (63.7±19.0, max 100). Qualitative data collected during telephone interviews showed that participants highly appreciated the content of the program. They elaborated that lower ratings of the program were mainly due to technical issues that hindered a smooth walk through. Participants reported that the program increased awareness of lifestyle factors related to brain health.

CONCLUSIONS

Overall user-experience of the online lifestyle program was moderate to positive. Qualitative data showed that content was appreciated and that flawless, easy access technique is essential. The heterogeneity in ratings of program content and in program use highlights the need for personalization. These findings support the use of online self-applied lifestyle programs when aiming to reach large groups of motivated at-risk individuals for brain health promotion.

Small mammal responses to long-term large-scale woodland creation: the influence of local and landscape-level attributes

Habitat loss and fragmentation greatly affect biological diversity. Actions to counteract their negative effects include increasing the quality, amount and connectivity of seminatural habitats at the landscape scale. However, much of the scientific evidence underpinning landscape restoration comes from studies of habitat loss and fragmentation, and it is unclear whether the ecological principles derived from habitat removal investigations are applicable to habitat creation. In addition, the relative importance of local- (e.g., improving habitat quality) vs. landscape-level (e.g., increasing habitat connectivity) actions to restore species is largely unknown, partly because studying species responses over sufficiently large spatial and temporal scales is challenging. We studied small mammal responses to large-scale woodland creation spanning 150 yr, and assessed the influence of local- and landscape-level characteristics on three small mammal species of varying woodland affinity. Woodland specialists, generalists, and grassland specialists were present in woodlands across a range of ages from 10 to 160 yr, demonstrating that these species can quickly colonize newly created woodlands. However, we found evidence that woodlands become gradually better over time for some species. The responses of individual species corresponded to their habitat specificity. A grassland specialist (Microtus agrestis) was influenced only by landscape attributes; a woodland generalist (Apodemus sylvaticus) and specialist (Myodes glareolus) were primarily influenced by local habitat attributes, and partially by landscape characteristics. At the local scale, high structural heterogeneity, large amounts of deadwood, and a relatively open understory positively influenced woodland species (both generalists and specialists); livestock grazing had strong negative effects on woodland species abundance. Actions to enhance habitat quality at the patch scale focusing on these attributes would benefit these species. Woodland creation in agricultural landscapes is also likely to benefit larger mammals and birds of prey feeding on small mammals and increase ecosystem processes such as seed dispersal.

The Amino Acid Sequence in Fibrin Responsible for High Affinity Thrombin Binding

Human fibrin has a low affinity thrombin binding site in its E domain and a high affinity binding site in the carboxy-terminal region of its variant ’ chain (’408-427). Comparison of the ’ amino acid sequence (VRPEHPAETEYDSLYPEDDL) with other protein sequences known to bind to thrombin exosites such as those in GPIb , the platelet thrombin receptor, thrombomodulin, and hirudin suggests no homology or consensus sequences, but Glu and Asp enrichment are common to all. Tyrosine sulfation in these sequences enhances thrombin exosite binding, but this has not been uniformly investigated. The fibrinogen ’ chain mass determined by electrospray ionization mass spectrometry, was 50,549 Da, a value 151 Da greater than predicted from its amino acid/carbohydrate sequence. Since each sulfate group increases mass by 80 Da, this indicates that both tyrosines at 418 and 422 are sulfated. A series of overlapping ’ peptides was prepared for evaluation of their inhibition of 125I-labeled PPACK-thrombin binding to fibrin. ’414-427 was as effective an inhibitor as ’408-427 and its binding affinity was dependent on all carboxy-terminal residues. Mono Tyr-sulfated peptides were prepared by substituting non-sulfatable Phe for Tyr at ’ 418 or 422. Sulfation at either Tyr residue increased binding competition compared with non-sulfated peptides, but was less effective than doubly sulfated peptides, which had 4 to 8-fold greater affinity. The reverse ’ peptide or the forward sequence with repositioned Tyr residues did not compete well for thrombin binding, indicating that the positions of charged residues are important for thrombin binding affinity

Hypofibrinogenaemia with Compound Heterozygosity for Two γ Chain Mutations – γ 82 Ala→Gly and an Intron Two GT→AT Splice Site Mutation

We investigated the molecular basis of hypofibrinogenaemia in a woman with a history of recurrent, pregnancy-associated bleeding, and miscarriage. She had a Clauss fibrinogen of 0.9 mg/ml and SDS PAGE of purified fibrinogen showed a normal pattern of chains. However careful inspection of reverse phase chain separation profiles showed apparent homozygosity for a more hydrophilic form of the γ chain. DNA Sequencing showed only heterozygosity for a CGT→GGT (Ala→Gly) mutation at codon γ82, but further sequencing showed an additional GT splice sequence mutation at the 5’ end of intron 2 of the γ gene. Translation of mRNA containing this intron would result in premature truncation explaining the phenotypic homozygosity of the γ82 Ala→Gly substitution. The patient’s sister had a mild bleeding disorder with hypofibrinogenaemia and she too was a compound heterozygote for the γ mutations. Her nephew had only the novel splice site mutation, while her mother and daughter inherited only the γ82 Ala→Gly substitution.

Oligosaccharide Configuration of Fibrinogen Kaiserslautern: Electrospray Ionisation Analysis of Intact γ Chains

Electrospray ionisation mass spectrometry was used to probe the structure of the new N-linked oligosaccharide in fibrinogen Kaiserslautern (γ 380 Lys→Asn). The mass increase of 2177 Da in the new γ chain indicated the attachment of a fully sialylated biantennary oligosaccharide on the new Asn residue; the expected increase for this change being 2192 Da. Some 95% of the new oligosaccharide was in the disialylated state while only 5% of the endogenous γ chain carbohydrate was disialylated in the control. Mass measurements of intact Kaiserslautern γ chains after neuraminidase treatment of the native fibrinogen confirmed a total of three residues of sialic acid in the dominant isoform. Incubation with endoglycosidase F showed that the new oligosaccharide was more resistant to hydrolysis than the endogenous one. Recent X-ray analyses of covalently linked D domains show that position γ 380 is distant from both the GPR binding pocket and the D-D interface. It appears that the polymerisation defect of this fibrinogen results from electrostatic repulsion between condensing protofibrils and that this is induced by the two new residues of sialic acid that are present on the new γ chain.

Hypofibrinogenemia due to Novel 316 Asp → Tyr Substitution in the Fibrinogen Bβ Chain

We investigated the molecular basis of hypofibrinogenemia in a woman with a plasma fibrinogen of 1.0 mg/mL. After sequencing the coding region and intronic boundaries of all three fibrinogen genes a single heterozygous GACTAC mutation was identified at codon 316 of the B gene. This AspTyr substitution segregated with the hypofibrinogenemia in the only other affected family member. Examination by SDS-PAGE, isoelectric focussing, reverse phase chromatography and electrospray ionisation (ESI) mass spectrometery, failed to detect expression of the new B chain in purified plasma fibrinogen. The absence of the variant chain was confirmed by ESI tryptic mapping; while the [M + 1 H] and [M + 2 H] ions of the affected peptide (MGPTELLIEMEDWK) were clearly visible at 1,692 and 847 m/z, there were no new signals (1741 or 871 m/z) that would at indicate expression of the variant in plasma. Asp 316 and itschain homologue (Asp 252) are conserved in all known species and this is the first report of a mutation at either of these. The residue appears to be critical in maintaining the structure of the five stranded sheet that forms the dominant structural feature of the D domains.

Novel Fibrinogen Truncation with Deletion of Bβ Chain Residues 440-461 causes Hypofibrinogenaemia

A 24-year-old male with hepatitis C was initially diagnosed with hypofibrinogenaemia during investigations prior to a liver biopsy. He had a low functional and gravimetric fibrinogen concentration of 1.0 mg/mL and DNA sequencing of all exons, exon-intron boundaries and promoter regions of the fibrinogen Aα, Bβ, and γ genes revealed a single heterozygous g→a mutation at nucleotide 8035 of the Bβ gene. This creates a premature stop at the Trp 440 codon and results in a 22-residue truncation of the Bβ chain. Analysis of purified plasma fibrinogen by SDS PAGE, reverse phase HPLC and ESI MS, however, failed to detect any of the truncated chains in the plasma fibrinogen. The non-expression of aberrant molecules was further confirmed by functional analysis, which revealed normal fibrin polymerisation. The principal structural feature of the independently folding βD domain is its five-stranded anti-parallel β sheet. The deletion here of residues 440 to 461 removes the second strand from this sheet structure and appears to impact on the viability of the nascent chain and its ability to be incorporated into mature fibrinogen molecules. The mutation does not however provoke the formation of hepatic inclusion bodies.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.