Genome-wide association analysis of coffee drinking suggests association with CYP1A1/CYP1A2 and NRCAM

Coffee consumption is a model for addictive behavior. We performed a meta-analysis of genome-wide association studies (GWASs) on coffee intake from 8 Caucasian cohorts (N=18 176) and sought replication of our top findings in a further 7929 individuals. We also performed a gene expression analysis treating different cell lines with caffeine. Genome-wide significant association was observed for two single-nucleotide polymorphisms (SNPs) in the 15q24 region. The two SNPs rs2470893 and rs2472297 (P-values=1.6 × 10(-11) and 2.7 × 10(-11)), which were also in strong linkage disequilibrium (r(2)=0.7) with each other, lie in the 23-kb long commonly shared 5' flanking region between CYP1A1 and CYP1A2 genes. CYP1A1 was found to be downregulated in lymphoblastoid cell lines treated with caffeine. CYP1A1 is known to metabolize polycyclic aromatic hydrocarbons, which are important constituents of coffee, whereas CYP1A2 is involved in the primary metabolism of caffeine. Significant evidence of association was also detected at rs382140 (P-value=3.9 × 10(-09)) near NRCAM-a gene implicated in vulnerability to addiction, and at another independent hit rs6495122 (P-value=7.1 × 10(-09))-an SNP associated with blood pressure-in the 15q24 region near the gene ULK3, in the meta-analysis of discovery and replication cohorts. Our results from GWASs and expression analysis also strongly implicate CAB39L in coffee drinking. Pathway analysis of differentially expressed genes revealed significantly enriched ubiquitin proteasome (P-value=2.2 × 10(-05)) and Parkinson's disease pathways (P-value=3.6 × 10(-05)).

Two doses of the SARS-CoV-2 BNT162b2 vaccine enhance antibody responses to variants in individuals with prior SARS-CoV-2 infection

Understanding the impact of prior infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the response to vaccination is a priority for responding to the coronavirus disease 2019 (COVID-19) pandemic. In particular, it is necessary to understand how prior infection plus vaccination can modulate immune responses against variants of concern. To address this, we sampled 20 individuals with and 25 individuals without confirmed previous SARS-CoV-2 infection from a large cohort of health care workers followed serologically since April 2020. All 45 individuals had received two doses of the Pfizer-BioNTech BNT162b2 vaccine with a delayed booster at 10 weeks. Absolute and neutralizing antibody titers against wild-type SARS-CoV-2 and variants were measured using enzyme immunoassays and pseudotype neutralization assays. We observed antibody reactivity against lineage A, B.1.351, and P.1 variants with increasing antigenic exposure, through either vaccination or natural infection. This improvement was further confirmed in neutralization assays using fixed dilutions of serum samples. The impact of antigenic exposure was more evident in enzyme immunoassays measuring SARS-CoV-2 spike protein–specific IgG antibody concentrations. Our data show that multiple exposures to SARS-CoV-2 spike protein in the context of a delayed booster expand the neutralizing breadth of the antibody response to neutralization-resistant SARS-CoV-2 variants. This suggests that additional vaccine boosts may be beneficial in improving immune responses against future SARS-CoV-2 variants of concern.

Free fibular graft still has a place in the treatment of bone defects

We report on 27 patients illustrating the use of non-vascularized single fibular strut graft, augmented with a corticocancellous bone graft to bridge bone defects. The indications were varied and included infection, fracture with bone loss, non-union, bone tumour, bone cyst and congenital pseudarthrosis. Primary union was achieved in 92 per cent. Stress fracture occurred in 26 per cent and no significant fibular graft hypertrophy occurred. The aim of this paper is to show that the non-vascularized single fibular graft, if augmented with corticocancellous bone graft along its whole length, is a simple procedure that is still valid to bridge bone defects.

Deep infection after hip hemiarthroplasty: risk factors for infection and outcome of treatments

AIMS

Deep surgical site infection (SSI) remains an unsolved problem after hip fracture. Debridement, antibiotic, and implant retention (DAIR) has become a mainstream treatment in elective periprosthetic joint infection; however, evidence for DAIR after infected hip hemiarthroplaty is limited.

METHODS

Patients who underwent a hemiarthroplasty between March 2007 and August 2018 were reviewed. Multivariable binary logistic regression was performed to identify and adjust for risk factors for SSI, and to identify factors predicting a successful DAIR at one year.

RESULTS

A total of 3,966 patients were identified. The overall rate of SSI was 1.7% (51 patients (1.3%) with deep SSI, and 18 (0.45%) with superficial SSI). In all, 50 patients underwent revision surgery for infection (43 with DAIR, and seven with excision arthroplasty). After adjustment for other variables, only concurrent urinary tract infection (odds ratio (OR) 2.78, 95% confidence interval (CI) 1.57 to 4.92; p < 0.001) and increasing delay to theatre for treatment of the fracture (OR 1.31 per day, 95% CI 1.12 to 1.52; p < 0.001) were predictors of developing a SSI, while a cemented arthroplasty was protective (OR 0.54, 95% CI 0.31 to 0.96; p = 0.031). In all, nine patients (20.9%) were alive at one year with a functioning hemiarthroplasty following DAIR, 20 (46.5%) required multiple surgical debridements after an initial DAIR, and 18 were converted to an excision arthroplasty due to persistent infection, with six were alive at one year. The culture of any gram-negative organism reduced success rates to 12.5% (no cases were successful with methicillin-resistant Staphylococcus aureus or Pseudomonas infection). Favourable organisms included Citrobacter and Proteus (100% cure rate). The all-cause mortality at one year after deep SSI was 55.87% versus 24.9% without deep infection.

CONCLUSION

Deep infection remains a devastating complication regardless of the treatment strategy employed. Success rates of DAIR are poor compared to total hip arthroplasty, and should be reserved for favourable organisms in patients able to tolerate multiple surgical procedures. Cite this article: Bone Jt Open 2021;2(11):958-965.

Characteristics of travelling waves under various conditions

In this mapping study, the goal was to investigate in 10 subjects the phenomenon of the travelling waves (TW), especially of alpha activity, under conditions of (1) rest, (2) calculations, (3) emotional experience and (4) pain. The TW during wakefulness usually arose from the areas with the highest amplitude of alpha, called major peaks, for both positive (pos.) and negative (neg.) polarities. These areas were Pz (pos. and neg.) at rest, O2 (pos.) and Pz (neg.) during calculation, O1 (pos.) and O2 (neg.) during emotion and T6 (pos.) and O1 (neg.) during pain. When differences were determined between the latter 3 conditions and the resting state, a focal event-related desynchronization (ERD) became evident on T5 during math, on Pz during emotion and on both CP areas during pain. Surrounding the areas of ERD were areas of event-related synchronization (ERS). The TW were related to phase differences between the different electrode locations, seen more frequently with the pos. polarity, and more often with emotion or calculation. The direction of the TW was most often toward the midline during rest, from the right to midline (calculation), from the left to midline (emotion) and from the midline to the left (pain). Changes on one side of the head were often associated with opposite types of changes on the other side. Sleep spindles were also analyzed showing the major peaks on Fz and F4 with pos. polarities often seen anteriorly and neg. polarities posteriorly. TW were also seen with spindles, more often with the positive polarity. The direction was usually from the midline for the positive polarity and toward the midline for the neg. phase. The phenomenon of the TW is discussed, especially its possible neurophysiological significance as a means of transmitting information throughout the brain.

How well can step-off and gap distances be reduced when treating intra-articular distal radius fractures with fragment specific fixation when using fluoroscopy

INTRODUCTION

Although fragment specific fixation has proved to be an effective treatment regime, it has not been established how successfully this treatment could be performed using fluoroscopy and what the added value of arthroscopy could be. Establish gap and step-off distances after in intra-articular distal radius fractures that have been treated with fragment specific fixation while using fluoroscopy.

MATERIAL

Forty-four patients with an intra-articular distal radius fracture were treated with fragment specific fixation while using fluoroscopy.

METHODS

After the treatment of the intra-articular distal radius fracture with fragment specific fixation and the use of fluoroscopy, but before the completion of the surgical intervention, all gap, and step-off distances were determined by using arthroscopy. In addition, the joint was checked for any other wrist pathologies.

RESULTS

Arthroscopy after the surgical intervention showed that in 37 patients no gap distances could be detected, while in six patients a gap distance of≤2mm was found and in one patient, a gap distance of 3mm. Similarly, arthroscopy revealed no step-off distances in 33 patients, while in 11 patients a step-off distance of≤2mm was found. Although additional wrist pathologies were found in 48% of our population, only one patient needed surgical intervention. Three months after the surgical intervention wrist flexion was 41±10°, wrist extension 51±17°, ulnar deviation 19±10°, radial deviation 32±12° while patients could pronate and supinate their wrist to 85±5° and 74±20°, respectively.

CONCLUSION

Intra-articular distal radius fractures can be treated successfully with fragment specific fixation and the use of fluoroscopy. As almost all gap and step-off distances could be reduced to an acceptable level, the scope for arthroscopy to further improve this treatment regime is limited. The functional outcome scores that were found 3 months after the surgical intervention were similar to what has been reported in other studies using different treatment option. These findings suggest that fragment specific fixation is a good alternative for treating intra-articular distal radius fractures. As in most cases, only fluoroscopy is needed for fragment specific fixation, this treatment technique is a good treatment option for resource-limited hospitals, setting who do not have access to arthroscopy.

LEVEL OF EVIDENCE

III, case-control study.

Can the Clinical Frailty Scale on admission predict 30-day survival, postoperative complications, and institutionalization in patients with fragility hip fracture? : a cohort study of 1,255 patients

AIMS

We assessed the value of the Clinical Frailty Scale (CFS) in the prediction of adverse outcome after hip fracture.

METHODS

Of 1,577 consecutive patients aged > 65 years with a fragility hip fracture admitted to one institution, for whom there were complete data, 1,255 (72%) were studied. Clinicians assigned CFS scores on admission. Audit personnel routinely prospectively completed the Standardised Audit of Hip Fracture in Europe form, including the following outcomes: 30-day survival; in-hospital complications; length of acute hospital stay; and new institutionalization. The relationship between the CFS scores and outcomes was examined graphically and the visual interpretations were tested statistically. The predictive values of the CFS and Nottingham Hip Fracture Score (NHFS) to predict 30-day mortality were compared using receiver operating characteristic area under the curve (AUC) analysis.

RESULTS

Significant non-linear associations between CFS and outcomes were observed. Risk of death within 30 days rose linearly for CFS 1 to 5, but plateaued for CFS > 5. The incidence of complications and length of stay rose linearly for CFS 1 to 4, but plateaued for CFS > 4. In contrast, the risk of new institutionalization rose linearly for CFS 1 to 8. The AUCs for 30-day mortality for the CFS and NHFS were very similar: CFS AUC 0.63 (95% CI 0.57 to 0.69) and NHFS AUC 0.63 (95% CI 0.57 to 0.69).

CONCLUSION

Use of the CFS may provide useful information on outcomes for fitter patients presenting with hip fracture, but completion of the CFS by the admitting orthopaedic team does not appear successful in distinguishing between higher CFS categories, which define patients with frailty. This makes a strong case for the role of the orthogeriatrician in the early assessment of these patients. Further work is needed to understand why patients assessed as being of mild, moderate, and severe frailty do not result in different outcomes. Cite this article: Bone Joint J 2022;104-B(8):980-986.

Genetic and gut microbiome determinants of SCFA circulating and fecal levels, postprandial responses and links to chronic and acute inflammation

Short-chain fatty acids (SCFA) are involved in immune system and inflammatory responses. We comprehensively assessed the host genetic and gut microbial contribution to a panel of eight serum and stool SCFAs in two cohorts (TwinsUK, n = 2507; ZOE PREDICT-1, n = 328), examined their postprandial changes and explored their links with chronic and acute inflammatory responses in healthy individuals and trauma patients. We report low concordance between circulating and fecal SCFAs, significant postprandial changes in most circulating SCFAs, and a heritable genetic component (average h2: serum = 14%(SD = 14%); stool = 12%(SD = 6%)). Furthermore, we find that gut microbiome can accurately predict their fecal levels (AUC>0.71) while presenting weaker associations with serum. Finally, we report different correlation patterns with inflammatory markers depending on the type of inflammatory response (chronic or acute trauma). Our results illustrate the breadth of the physiological relevance of SCFAs on human inflammatory and metabolic responses highlighting the need for a deeper understanding of this important class of molecules.

Longitudinal assessment of symptoms and risk of SARS-CoV-2 infection in healthcare workers across 5 hospitals to understand ethnic differences in infection risk

BACKGROUND

: Healthcare workers (HCWs) have increased rates of SARS-CoV-2 infection compared with the general population. We aimed to understand ethnic differences in SARS-CoV-2 seropositivity among hospital healthcare workers depending on their hospital role, socioeconomic status, Covid-19 symptoms and basic demographics.

METHODS

A prospective longitudinal observational cohort study. 1364 HCWs at five UK hospitals were studied with up to 16 weeks of symptom questionnaires and antibody testing (to both nucleocapsid and spike protein) during the first UK wave in five NHS hospitals between March 20 and July 10 2020. The main outcome measures were SARS-CoV-2 infection (seropositivity at any time-point) and symptoms. Registration number: NCT04318314.

FINDINGS

272 of 1364 HCWs (mean age 40.7 years, 72% female, 74% White, ≥6 samples per participant) seroconverted, reporting predominantly mild or no symptoms. Seropositivity was lower in Intensive Therapy Unit (ITU) workers (OR=0.44 95%CI 0.24, 0.77; p=0.0035). Seropositivity was higher in Black (compared to White) participants, independent of age, sex, role and index of multiple deprivation (OR=2.61 95%CI 1.47-4.62 p=0.0009). No association was seen between White HCWs and other minority ethnic groups.

INTERPRETATION

In the UK first wave, Black ethnicity (but not other ethnicities) more than doubled HCWs likelihood of seropositivity, independent of age, sex, measured socio-economic factors and hospital role.

Ultrasonography detection of radiolucent foreign bodies in soft tissue compared to computed tomography scan

Thirty-one patients with suspected radiolucent foreign bodies (wooden splinters) in soft tissues of extremities were investigated by plain radiography, computed tomography (CT) scan and ultrasonography to the area suspected clinically. Ultrasonography detected and localized radiolucent foreign bodies in 18 of the 31 patients, while only 14 were seen on CT scan. Following surgical exploration, the presence of foreign bodies was confirmed in 20 patients; thus, the accuracy of ultrasonography was 90% while that of CT scan was 70%. The size of foreign body, the presence of infection or the delay in diagnosis had no effect on results. Ultrasonography is clearly a reliable method of detecting radiolucent foreign bodies in soft tissues of extremities.

Decontamination and Reuse of N95 Masks: A Narrative Review

BACKGROUND

The COVID-19 pandemic has presented an unprecedented strain on healthcare supplies. Currently there is a global shortage of personal protective equipment (PPE), especially N95 masks. In order to safeguard healthcare personnel in this critical time and to mitigate shortages of N95 respirators, reuse of N95 respirators has to be considered.

METHODS

Using PubMed and Science Direct, a literature search was conducted to find and synthesize relevant literature on decontamination of N95 respirators for their subsequent reuse. Peer-reviewed publications related to methods of decontamination from January 2007 to April 2020 in the English language are included in this narrative review. Bibliographies of articles for relevant literature were also scrutinized. Findings. A total of 19 studies are included in this narrative review. The appraised methods include ultraviolet germicidal irradiation (UVGI), moist heat incubation (MHI), ethylene oxide (EtO), hydrogen peroxide vapor (HPV), microwave steam bags (MSB), microwave-generated steam (MGS), dry microwave oven irradiation, hydrogen peroxide gas plasma (HPGP), dry heat, liquid hydrogen peroxide, and bleach and alcohol.

CONCLUSION

In light of the COVID-19 pandemic, reuse of N95 respirators, although suboptimal, can be considered. Evidence reveals that UVGI, MHI, and HPV are amongst the safest and efficacious methods for decontamination of N95 masks. More research is needed to establish the safety and effectiveness of MGS, MSB, dry heat, EtO, liquid hydrogen peroxide, and HPGP. Alcohol, microwave irradiation, and bleach are not recommended because they damage N95 respirators.

Sciatic nerve neuritis of no cause in primary total hip replacement: A case series

Neuritis of the sciatic nerve is a rare complication of total hip replacements. It is characterized by symptoms of neuropathic pain with or without motor and or sensory symptoms. Causes include direct intra-operative trauma or mechanical lengthening of the nerve. Cases of sciatic nerve neuritis without an organic cause however, are rarer still. We present two cases of sciatic nerve neuritis post total hip replacement with no identified organic cause. Whereas the reversal of the underlying cause has shown improvement in symptoms, in cases without an organic cause our experience advocates close observation and conservative management with spontaneous resolution of symptoms.

Reinfection or relapse of COVID-19 in health care workers; case series of 2 patients from Pakistan

During an ongoing pandemic of severe acute respiratory syndrome coronavirus 2, main question which has arisen in everyone's mind is about the immune response that may protect from reinfection. Coronaviruses are known for short-term immunity. Their ability of mutations enables them to escape host immunity, thus increasing chances of reinfection. Here we report two cases of reinfection among health care workers who presented with symptoms of COVID-19 disease, after 3 months of first infectious course. Such documentations are necessary for epidemiological purposes and also to monitor response of virus on re-exposure.

Bony non-union in a patient receiving androgen deprivation therapy for prostate cancer

We present a case of a 76-year-old man who underwent a corrective femoral osteotomy for a varus deformity and stress fractures. The patient was on androgen deprivation therapy (ADT) for prostate cancer and the osteotomy failed to heal. At 13 months, the ADT was stopped and bony union was achieved in 3 months. Orthopaedic surgeons treating fractures in this patient population need to aware of the problems associated with ADT and closely liaise with oncologists and urologists to stop ADT or start alternative treatment until bony union has been achieved.