212 FATIGUE EXPERIENCED BY ADULTS WITH LONG-COVID WAS NOT ASSOCIATED WITH AN EMG-DERIVED MUSCLE FATIGUE INDEX

Background

One of the most prominent challenges of the COVID-19 pandemic is the emergence of the post-COVID-19 syndrome or ‘long-COVID’ following the acute phase of the viral infection. With a plethora of debilitating symptoms across many physiological systems, the pathophysiology of long-COVID remains elusive and subject of intense research efforts. Adults with long COVID are often affected by prolonged fatigue, which could be linked to neuromuscular function impairment. We hypothesised that there might be a correlation between subjective fatigue and an Electromyograph(EMG)-derived muscle fatigue index in adults with long-COVID.

Methods

As part of a neuro-cardiovascular instability assessment protocol, participants were asked to squeeze the thigh muscles as hard as possible for ten seconds during both supine resting and after active and passive standing (head-up tilt) tests. Surface EMG was used to capture on each leg the physiological activity of the vastus lateralis and rectus femoris during the squeezes, from which the muscle fatigue index was computed based on both the mean and median frequencies of each 10-second maximum prompted muscle contraction. Using two-sided Spearman correlation coefficients, we examined the associations between the muscle fatigue indices and self-reported fatigue measured by the Chalder Fatigue Scale (CFQ).

Results

108 participants were included, 77 female and 31 male, with a mean age of 46 (range 25-78) years, 22% of whom were hospitalised in the acute phase of SARS-CoV-2 infection. Strong intercorrelations were found between the muscle fatigue indices derived from the mean and median frequencies of thigh muscle contractions. However, no significant correlations were detected between the muscle fatigue indices and CFQ scores.

Conclusion

Self-reported fatigue as measured by the CFQ was not associated with an EMG-derived muscle fatigue index in this long-COVID cohort.

123 ACUTE-PHASE BED-REST DURATION WAS ASSOCIATED WITH LOWER GRIP STRENGTH IN A POST-COVID-19 COHORT

Background

Though age-related muscle loss is traditionally associated with older cohorts, strong evidence suggests a life-spanning precipitation of decreasing muscle mass and strength beginning as early as the fourth decade of life, with established deleterious consequences for later-life morbidity and mortality. Periods of low activity and bed rest (LA/BR) can further compound this depletion of muscle strength. Our aim was to examine such associations in a post-COVID-19 cohort.

Methods

Participants reporting ongoing symptomatology and fatigue post COVID-19 underwent assessments of grip strength via hand-held dynamometry (2 measures on each hand). Demographics of COVID-19 illness, including time since diagnosis, duration of LA/BR during acute illness, and levels of fatigue were captured via self-reported questionnaires. Independent predictors of mean grip strength were investigated using a linear regression model.

Results

Forty-nine participants underwent assessments (69% female, mean age 44(12) years). At the time of assessment, days post COVID-19 diagnosis ranged from 39–522 (mean 262(140)). The mean self-reported period of LA/BR during the acute illness was 15(18) days. In general, participants reported significant levels of fatigue (median Chalder Fatigue Scale score 22(8)). Mean grip strength was 41.3(6.3) Kg for men and 22.8(6.7) Kg for women. When predictors of grip strength were investigated, an increased duration of LA/BR was found to be associated with lower grip strength, independently of age, gender, time since COVID-19 diagnosis, and self-reported fatigue (Beta = −0.158, 95% Confidence Interval − 0.242 to −0.074, p = 0.001).

Conclusion

In this cohort, every day of LA/BR during acute COVID-19 illness was independently associated with subsequent lower grip strength of approximately 150 g. These results underscore the importance of early mobilization and discouraging bed rest in the acute phase of COVID-19. Patients who are isolating should be encouraged to maintain physical activity and muscle strength as part of a modified isolation-friendly rehabilitation programme.

Meta-analysis of the influence of lifestyle changes for preoperative weight loss on surgical outcomes

Background

The aim was to investigate whether preoperative weight loss results in improved clinical outcomes in surgical patients with clinically significant obesity.

Methods

This was a systematic review and aggregate data meta-analysis of RCTs and cohort studies. PubMed, MEDLINE, Embase and CINAHL Plus databases were searched from inception to February 2018. Eligibility criteria were: studies assessing the effect of weight loss interventions (low-energy diets with or without an exercise component) on clinical outcomes in patients undergoing any surgical procedure. Data on 30-day or all-cause in-hospital mortality were extracted and synthesized in meta-analyses. Postoperative thromboembolic complications, duration of surgery, infection and duration of hospital stay were also assessed.

Results

A total of 6060 patients in four RCTs and 12 cohort studies, all from European and North American centres, were identified. Most were in the field of bariatric surgery and all had some methodological limitations. The pooled effect estimate suggested that preoperative weight loss programmes were effective, leading to significant weight reduction compared with controls: mean difference –7·42 (95 per cent c.i. –10·09 to –4·74) kg (P < 0·001). Preoperative weight loss interventions were not associated with a reduction in perioperative mortality (odds ratio 1·41, 95 per cent c.i. 0·24 to 8·40; I2 = 0 per cent, P = 0·66) but the event rate was low. The weight loss groups had shorter hospital stay (by 27 per cent). No differences were found for morbidity.

Conclusion

This limited preoperative weight loss has advantages but may not alter the postoperative morbidity or mortality risk.

Venous malformations of the head and neck: current concepts in management

Low-flow venous malformations are congenital lesions and they are the third most common vascular anomaly in the head and neck. In this paper, the third in a series of three educational reviews, we discuss current trends in their management, and include a summary of common sclerosant agents used in their control.

The use of foam sclerotherapy to treat low-flow vascular malformations of the head and neck

Liquid sclerotherapy, laser and surgery have been used in the treatment of head and neck vascular anomalies with variable success for many years. A multidisciplinary team consisting of plastic surgery, maxillofacial surgery and interventional radiology currently treats such lesions by converting liquid sclerosant into foam. Foam sclerotherapy is currently used successfully to treat varicosities of the lower limbs and in this study, we present four cases in which 3% sodium tetradecyl sulfate has been used to treat low-flow vascular malformations in the head and neck.

The contemporary management of midface and craniofacial trauma

The successful management of midface and craniofacial trauma requires a thorough understanding of the anatomy and functional demands of this complex region. To achieve optimal outcomes, it is necessary that these injuries are accurately diagnosed and managed in a multi-disciplinary environment at the appropriate time. This review article discusses an overview of these injuries and highlights some of the key principles of management.

Carbon deposition and phase transformations in red mud on exposure to methane

A characterization study detailing the phase transformations and microstructural nature of the carbon deposited during methane decomposition over red mud has been undertaken. In situ XRD was carried out to study the phase transformation sequences of red mud during the reaction. Scanning electron microscopy, high resolution transmission electron microscopy, thermogravimetric analysis, BET surface area determination and CHN analysis were carried out to investigate the properties of the post-reaction samples. Exposure to methane with increasing temperature caused a stepwise reduction of iron oxides in red mud and promoted methane cracking leading to carbon deposition. The presence of carbon nanostructures was confirmed by HRTEM observations. The carbon formed was graphitic in nature and the spent red mud, rich in Fe and Fe(3)C formed as a result of the reduction of the iron oxide, was magnetic in nature. The surface area of the material was enhanced upon reaction. In addition, reactivity comparisons between goethite and red mud were carried out to study the formation of carbon oxides during reaction.

Use of a temporary cohort ward as part of an intervention to reduce the incidence of meticillin-resistant Staphylococcus aureus in a vascular surgery ward

This article describes the effect of introducing a cohort area into a vascular surgery ward where a sustained increase in new cases of meticillin-resistant Staphylococcus aureus (MRSA) made the implementation of standard MRSA infection control precautions untenable. A recent review of published reports concluded, 'that little evidence could be found to suggest that isolation measures recommended in the UK are effective'. The authors recommended a reporting format to enable the evidence for isolation to be gathered more systematically. This paper follows the recommended reporting format. The setting was a 30-bedded acute and subacute vascular surgery ward within a tertiary care hospital in Glasgow, UK. The data were analysed as an interrupted time series of 19 months pre-cohort, eight months with cohort and eight months post cohort. Following the instigation of the cohort area, there was a significant reduction in the number of nosocomial MRSA isolates from patients (P=0.0005). This reduction was sustained after the cohort area was discontinued. In conclusion, effective separation of MRSA-colonized/-infected patients from patients who are not colonized/infected with MRSA, using a cohort area, resulted in a significant reduction in MRSA cross-colonization and cross-infection. The resulting reduction in MRSA prevalence within the unit facilitated effective screening and isolation of subsequent patients once the cohort area had been discontinued.

Acute exacerbation of macroglossia

We report the case of a large venous malformation of the tongue, preventing the patient from being able to contain it within the oral cavity. The extent of the malformation precluded a complete surgical excision. The immediate problems were; impending airway compromise, inability to speak, eat or drink, severe discomfort due to exposure-induced dryness and an embarrassing spectacle. This case demonstrates that even malformations considered to be incurable may be managed appropriately.

Dysregulated expression of the major telomerase components in leukaemic stem cells

Telomere loss is rapid during the progression of chronic myeloid leukaemia (CML) and correlates with prognosis. We therefore sought to measure expression of the major telomerase components (hTR and hTERT) in CD34+ cells from CML patients and normal controls, to determine if their altered expression may contribute to telomere attrition in vivo. High-purity (median 94.1%) BCR-ABL+ CD34+ cells from CML (n=16) and non-CML (n=14) patients were used. CML samples had a small increase in telomerase activity (TA) compared to normal samples (approximately 1.5-fold, P=0.004), which was inversely correlated with the percentage of G0 cells (P=0.02) suggesting TA may not be elevated on a cell-to-cell basis in CML. Consistent with this, hTERT mRNA expression was not significantly elevated; however, altered mRNA splicing appeared to play a significant role in determining overall full length, functional hTERT levels. Interestingly, Q-RT-PCR for hTR demonstrated a mean five-fold reduction in levels in the chronic phase (CP) CML samples (P=0.002), raising the possibility that telomere homeostasis is disrupted in CML. In summary, the molecular events regulating telomerase gene expression and telomere maintenance during the CP of CML may influence the disease progression observed in these patients.

Cortical bone screw fixation in ionically modified apatite cements

Hydroxyapatite cements are used in reconstruction of the face; usually in well-defined cavities where the cement can be stabilized without the need for internal fixation. A hydroxyapatite cement that could enable screw fixation and some loading therefore has considerable potential in maxillofacial reconstruction. It has been demonstrated recently that water demand of calcium phosphate cements can be reduced by ionically modifying the liquid component. This study investigated the capacity of an ionically modified precompacted apatite cement to retain self-tapping cortical bone screws. Screw pullout forces were determined in the direction of the screw long axis and perpendicular to it, using cortical bone and polymethylmethacrylate cement as a control. In bending pullout tests, measured forces to remove screws from ionically modified precompacted cement were insignificantly different from cortical bone. However, pullout forces of bone screws from hydroxyapatite cement decreased with aging time in vitro.

Modified retractor for use in sectioning the inferior alveolar nerve

We designed a modified tonsillar blade to retract the tissues medial to the ramus of the mandible to gain access to the inferior alveolar nerve at the lingula.

Clinical leadership

FOR SOME TIME now we have been contemplating the meaning of leadership. We recognised the need to discover a new direction to refresh the environments in which we work and aid implementation of the emerging health- care agenda. Most of all, we wanted to develop a leadership style that would, by focusing on team and group working, have an impact on patient care.

Pyridoxal 5'-phosphate inhibition of adenovirus DNA polymerase

Pyridoxal phosphate modification of adenovirus DNA polymerase results in loss of DNA polymerase activity, whereas the 3' --> 5' exonuclease activity is unaffected. Inhibition by pyridoxal phosphate is time-dependent, displays saturation kinetics, and is reversible in the presence of excess primary amine unless the pyridoxal phosphate-enzyme adduct is first reduced with NaBH4. Thus, inhibition is the consequence of Schiff base formation between the aldehyde moiety of pyridoxal phosphate and primary amino groups on the enzyme. In addition to inhibiting DNA polymerase activity, pyridoxal phosphate also inhibited the ability of the enzyme to initiate viral DNA replication, by transfer of dCMP onto the preterminal protein. Neither template-primer nor dNTP protect against pyridoxal phosphate inhibition, but the combination of template-primer and complementary substrate dNTP protected both initiation and DNA polymerase activities. Thus, it is likely that both the dCMP transfer activity required for initiation and DNA polymerase activity are carried out at the same site of the enzyme.

Malignant hyperpyrexia in oral surgery--case report and literature review

A case of malignant hyperpyrexia (MH) occurring in a patient undergoing orthognathic surgery is reported which resulted in the procedure being abandoned prior to completion. The oral surgeon's role in recognising the early clinical signs of masseteric spasm and central cyanosis is highlighted. The case shows that with proper investigation and management the MH susceptible patient was able to have a second anaesthetic with safety to complete the surgery.

Adenovirus DNA binding protein: helix destabilising properties

Adenovirus DNA binding protein is a multifunctional protein essential for viral DNA replication. To investigate the role of the DNA binding protein in this process its interaction with partial DNA duplexes was examined. Duplex regions of DNA, created when a short DNA strand is annealed to its complementary sequence present in the single stranded form of M13 phage DNA, were efficiently unwound by DNA binding protein in a reaction that required neither ATP nor MgCl2. The unwinding activity of DNA binding protein was reduced by conditions which increased the stability of DNA duplexes. DNA unwinding by DNA binding protein was highly co-operative and required the single stranded DNA to be completely coated with the protein. Completely double stranded DNA could also be unwound by DNA binding protein but this reaction was sensitive to the G+C content of the DNA and could only be observed with relatively short DNA duplexes up to 45 base pairs in length. When these short double stranded DNA molecules contained binding sites for the transcription factors NFI and NFIII addition of the cognate factor blocked DNA binding protein mediated unwinding of the particular DNA duplex. Cleavage of DNA binding protein with chymotrypsin and isolation of the 39,000 molecular weight C-terminal fragment indicated that the unwinding activity was located in this domain of the protein. In support of this contention a monoclonal antibody, which had previously been mapped to this region, specifically inhibited the DNA unwinding activity. These activities of DNA binding protein are likely to be involved in DNA replication, where the destabilisation of DNA duplexes could be important both during initiation and elongation.