Late diagnosis of HIV: A lookback on cases in North Cumbria

Late diagnosis of HIV remains a threat to personal and public health – both increasing the morbidity and mortality of the person and also increasing the chance of unknowingly transmitting HIV. Many HIV testing initiatives, including those of the British HIV Association (BHIVA), focus on levels of high prevalence (greater than 2:1000). However, late diagnosis can be an issue in areas of low prevalence – areas which can be less densely populated and in some cases classified as rural. In our rural catchment area, late diagnosis is an issue with 67% diagnosed late in 2015 (which is skewed by the single figure diagnoses). This lookback examined the number of missed opportunities for HIV diagnosis over a seven-year period and found that where diagnoses were made late in the context of a person having previously presented for care, unexplained weight loss, blood dyscrasias and lymphadenopathy were the most common presentations that could have triggered a HIV test.

Association of Salivary Amylase (AMY1) Gene Copy Number with Obesity in Alabama Elementary School Children

Salivary amylase (AMY1) is the most abundant enzyme in human saliva, responsible for the hydrolysis of α-1,4 glycosidic linkages that aids in the digestion of starch. Recently studies have shown that the copy number of AMY1 is associated with obesity; however, the data varies with location. One-third of children are overweight/obese in Alabama. In this study, we aim to determine the relationship between the copy number of AMY1 gene and obesity measurements in children from Alabama. One hundred twenty-seven children aged between 6 to 10 years participated in this study. Anthropometric measurements were measured using WHO recommendations. Genomic DNA was extracted from saliva, and the copy number of the AMY1 gene was estimated by digital PCR. The association between AMY1 copy number and obesity measurements was analyzed by linear regression. The mean AMY1 copy number significantly decreased in overweight/obese (6.21 ± 1.48) compared to normal weight (7.97 ± 2.35) children. AMY1 copy number inversely associated with the obesity measurements. African Americans had a stronger association between low AMY1 copy number and obesity compared to white/European Americans. Our findings suggest that overweight/obese children have a low AMY1 copy number and the effect is more prominent in African Americans.

2019 Frank Stinchfield Award: A comparison of prosthetic joint infection rates between direct anterior and non-anterior approach total hip arthroplasty

AIMS

We studied the impact of direct anterior (DA) versus non-anterior (NA) surgical approaches on prosthetic joint infection (PJI), and examined the impact of new perioperative protocols on PJI rates following all surgical approaches at a single institution.

PATIENTS AND METHODS

A total of 6086 consecutive patients undergoing primary total hip arthroplasty (THA) at a single institution between 2013 and 2016 were retrospectively evaluated. Data obtained from electronic patient medical records included age, sex, body mass index (BMI), medical comorbidities, surgical approach, and presence of deep PJI. There were 3053 male patients (50.1%) and 3033 female patients (49.9%). The mean age and BMI of the entire cohort was 62.7 years (18 to 102, sd 12.3) and 28.8 kg/m² (13.3 to 57.6, sd 6.1), respectively. Infection rates were calculated yearly for the DA and NA approach groups. Covariates were assessed and used in multivariate analysis to calculate adjusted odds ratios (ORs) for risk of development of PJI with DA compared with NA approaches. In order to determine the effect of adopting a set of infection prevention protocols on PJI, we calculated ORs for PJI comparing patients undergoing THA for two distinct time periods: 2013 to 2014 and 2015 to 2016. These periods corresponded to before and after we implemented a set of perioperative infection protocols.

RESULTS

There were 1985 patients in the DA group and 4101 patients in the NA group. The overall rate of PJI at our institution during the study period was 0.82% (50/6086) and decreased from 0.96% (12/1245) in 2013 to 0.53% (10/1870) in 2016. There were 24 deep PJIs in the DA group (1.22%) and 26 deep PJIs in the NA group (0.63%; p = 0.023). After multivariate analysis, the DA approach was 2.2 times more likely to result in PJI than the NA approach (OR 2.2 (95% confidence interval 1.1 to 3.9); p = 0.006) for the overall study period.

CONCLUSION

We found a higher rate of PJI in DA versus NA approaches. Infection prevention protocols such as use of aspirin, dilute povidone-iodine lavage, vancomycin powder, and Gram-negative coverage may have been positively associated with diminished PJI rates observed for all approaches over time. Cite this article: Bone Joint J 2019;101-B(6 Supple B):2-8.

Treatment data and technical process challenges for practical big data efforts in radiation oncology

The term Big Data has come to encompass a number of concepts and uses within medicine. This paper lays out the relevance and application of large collections of data in the radiation oncology community. We describe the potential importance and uses in clinical practice. The important concepts are then described and how they have been or could be implemented are discussed. Impediments to progress in the collection and use of sufficient quantities of data are also described. Finally, recommendations for how the community can move forward to achieve the potential of big data in radiation oncology are provided.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

HSC-requirement for macrophage regeneration is tissue-specific

The current paradigm posits that a single long-term hematopoietic stem cell (LT-HSC) is capable of regenerating all components of the immune system. However, recent studies have overturned this paradigm by showing that tissue-resident macrophages (in brain, skin, and liver) develop from fetal progenitors in the yolk sac that emerge separate from, and prior to, the LT-HSC.

Recently, we have identified novel subsets of tissue-resident macrophages in the mouse peritoneum, namely Small and Large Peritoneal Macrophages (SPM and LPM). Here, using Runx1 lineage-tracing assays, we show that, similar to brain microglia, both SPM and LPM emerge at around embryonic day 8 (E8), prior to, and independent of, the conventional LT-HSC. However, after E11, the fetal liver LT-HSC can be called upon to regenerate both SPM and LPM, but not microglia. Single-cell high-dimensional phenotypic and gene expression assays reveal that LT-HSC-derived SPM and LPM are phenotypically and functionally comparable to their E8-derived yolk sac counterpart. After birth, and throughout adulthood, both peritoneum and liver, but not the brain, call upon LT-HSCs in the bone marrow to continuously regenerate their fetal-derived tissue-resident macrophages.

These results suggest that the requirement for LT-HSCs to regenerate macrophages is tissue-specific. In rodents, both peritoneum and liver, but not the brain, might be exposed to injuries and other exogenous insults that could require constant regeneration of their tissue-resident macrophages. Collectively, these findings add a new layer to the complex developmental landscape of the myeloid lineage and challenge the current notion that tissue-resident macrophages develop independently of the LT-HSCs.

Relationship Between 'Immediate' Resistive Index Measurement After Renal Transplantation and Renal Allograft Outcomes

BACKGROUND

The arterial resistive index, also referred to as the resistive index (RI) or Pourcelot Index, is a measure of pulsatile blood flow. Previous studies have demonstrated the usefulness of the RI as a predictor of allograft outcomes based on RI measurement in the later stages after transplantation. However, there is little evidence of the predictive value of "immediate" RI measurement within 24 hours after transplantation.

METHODS

We performed a retrospective cohort study of 305 adult renal transplants carried out between 2003 and 2013. The associations between immediate RI measurement (within 24 hours after transplantation) and donor, recipient, and surgical factors were analyzed. In addition, the correlations between immediate RI measurement and renal allograft outcomes, including delayed graft function (DGF) and transplant failure (TF), also were evaluated.

RESULTS

From a cohort of 305 patients, 52 were excluded on the basis of on confounding factors. Of the remaining 253 patients, the mean age was 48.4 years, 57.5% were male, and approximately one-third had diabetes. Two hundred twenty-six patients had an RI < 0.8, whereas only 27 had an RI ≥ 0.8. Significant associations were found between elevated RI (≥0.8) and both DGF (odds ratio = 3.22, P = .006) and TF (odds ratio = 3.54, P = .008).

CONCLUSIONS

Immediate RI measurement after renal transplantation is a strong predictor of both DGF and TF.

A comparative study of human exposures to household air pollution from commonly used cookstoves in Sri Lanka

Solid fuel burning cookstoves are a major source of household air pollution (HAP) and a significant environmental health risk in Sri Lanka. We report results of the first field study in Sri Lanka to include direct measurements of both real-time indoor concentrations and personal exposures of fine particulate matter (PM_2.5 ) in households using the two most common stove types in Sri Lanka. A purposive sample of 53 households was selected in the rural community of Kopiwatta in central Sri Lanka, roughly balanced for stove type (traditional or improved 'Anagi') and ventilation (chimney present or absent). At each household, 48-h continuous real-time measurements of indoor kitchen PM_2.5 and personal (primary cook) PM_2.5 concentrations were measured using the RTI MicroPEM^™ personal exposure monitor. Questionnaires were used to collect data related to household demographics, characteristics, and self-reported health symptoms. All primary cooks were female and of an average age of 47 years, with 66% having completed primary education. Median income was slightly over half the national median monthly income. Use of Anagi stoves was positively associated with a higher education level of the primary cook (P = 0.026), although not associated with household income (P = 0.18). The MicroPEM monitors were well-received by participants, and this study's valid data capture rate exceeded 97%. Participant wearing compliance during waking hours was on average 87.2% on Day 1 and 83.3% on Day 2. Periods of non-compliance occurred solely during non-cooking times. The measured median 48-h average indoor PM_2.5 concentration for households with Anagi stoves was 64 μg/m³ if a chimney was present and 181 μg/m³ if not. For households using traditional stoves, these values were 70 μg/m³ if a chimney was present and 371 μg/m³ if not. Overall, measured indoor PM_2.5 concentrations ranged from a minimum of 33 μg/m³ to a maximum of 940 μg/m³ , while personal exposure concentrations ranged from 34 to 522 μg/m³ . Linear mixed effects modeling of the dependence of indoor concentrations on stove type and presence or absence of chimney showed a significant chimney effect (65% reduction; P < 0.001) and an almost significant stove effect (24% reduction; P = 0.054). Primary cooks in households without chimneys were exposed to substantially higher levels of HAP than those in households with chimneys, while exposures in households with traditional stoves were moderately higher than those with improved Anagi stoves. As expected, simultaneously measuring both indoor concentrations and personal exposure levels indicate significant exposure misclassification bias will likely result from the use of a stationary monitor as a proxy for personal exposure. While personal exposure monitoring is more complex and expensive than deploying simple stationary devices, the value an active personal PM monitor like the MicroPEM adds to an exposure study should be considered in future study designs.

Association between child caries and maternal health-related behaviours

OBJECTIVE

To examine the association between 2-6 year-olds' caries experience and selected maternal oral and general health-related behaviours in an American sample.

METHODS

Data pertaining to 917 child/mother pairs was from the Third National Health and Nutrition Examination Survey 1988-1994. Child caries experience was indicated by the presence of one or more decayed or filled tooth. Data on maternal smoking, frequency of dental visits, consumption of unhealthy food and oral hygiene was linked to children data using the natality file. An aggregate behavioural variable was created. Logistic Regression models were used to assess the association between child caries experience and maternal behaviours adjusting for child's age, gender, ethnicity, dental visits and mother's age, education and poverty-income ratio.

RESULTS

All four maternal behaviours were significantly associated with child caries in fully adjusted models with odds ratios 1.42 (95% CI: 1.01,2.01) for current smokers versus non-smokers, 1.01 (95% CI: 1.01,1.02) for frequent consumption of unhealthy food, 1.63 (95% CI: 1.15,2.31) for infrequent dental visits, and 2.49 (95% CI: 1.44,4.29) for poor oral hygiene.

CONCLUSIONS

The results indicate that children's caries experience is related to a number of maternal behaviours including behaviours not directly related to caries such as smoking. Maternal oral and general health-related behaviours should be incorporated in children's caries risk assessment and in behaviour changing interventions provided in dental practice to improve children's oral health.

Medical humanities: a closer look at learning

The inclusion of medical humanities with medical curricula is a question that has been the focus of attention for many within the evolving field. This study addressed the question from a medical education perspective and aimed to investigate what students at Trinity College Dublin learned from participating in a short medical humanities student-selected module in their first year of an undergraduate medical programme. A total of 156 students provided a written reflection on a memorable event that occurred during their student-selected module. The reflections were analysed using the Reflection Evaluation for Learners' Enhanced Competencies Tool (REFLECT) and through qualitative thematic analysis of the written reflections. Evidence of learning from the REFLECT quantitative analysis showed that 50% of students displayed higher levels of reflection when describing their experience. The reflection content analysis supported the heterogeneous nature of learning outcome for students, with evidence to support the idea that the module provided opportunities for students to explore their beliefs, ideas and feelings regarding a range of areas outside their current experience or world view, to consider the views of others that they may have not previously been aware of, to reflect on their current views, and to consider their future professional practice.

Fetal Hematopoietic Stem Cell Transplantation Fails to Fully Regenerate the B-Lymphocyte Compartment

B cells are key components of cellular and humoral immunity and, like all lymphocytes, are thought to originate and renew from hematopoietic stem cells (HSCs). However, our recent single-HSC transfer studies demonstrate that adult bone marrow HSCs do not regenerate B-1a, a subset of tissue B cells required for protection against pneumonia, influenza, and other infections. Since B-1a are regenerated by transfers of fetal liver, the question arises as to whether B-1a derive from fetal, but not adult, HSCs. Here we show that, similar to adult HSCs, fetal HSCs selectively fail to regenerate B-1a. We also show that, in humanized mice, human fetal liver regenerates tissue B cells that are phenotypically similar to murine B-1a, raising the question of whether human HSC transplantation, the mainstay of such models, is sufficient to regenerate human B-1a. Thus, our studies overtly challenge the current paradigm that HSCs give rise to all components of the immune system.

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Purified LT-HSC transplantation fails to fully regenerate the murine immune system

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LT-HSC transplants selectively fail to regenerate B-1a cells

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LT-HSC transplantation does not regenerate VH11-encoded natural antibodies

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Human fetal liver regenerate peritoneal B cells that resemble murine B-1a

Alternate electrode placement for whole body and segmental bioimpedance spectroscopy

Bioimpedance spectroscopy (BIS) is frequently used to monitor body fluid and body composition in healthy and clinical populations. BIS guidelines state that there should be no skin lesions at the site of electrodes, and if lesions are present, electrode positions should be changed. However, alternate electrode positions are yet to be reported. This study aimed to determine if ventral electrode placements were suitable alternatives for whole body and segmental BIS measurements. Three alternate electrode placements were assessed for whole body BIS using a combination of ventral hand and foot electrode placements. An alternate position was assessed for upper and lower body segmental BIS. The results demonstrated that for whole body BIS, if drive and sense electrodes on the hand are moved to ventral positions, but foot electrodes remain in standard positions, then whole body BIS variables were comparable to standard electrode positioning (percentage difference range  =  0.01 to 1.65%, p  =  0.211-0.937). The alternate electrode placement for upper limb segmental BIS, results in BIS variables that are comparable to that of the standard positioning (percentage difference range  =  0.24-3.51%, p  =  0.393-0.604). The alternate lower limb electrode position significantly altered all resistance and predicted BIS variables for whole body and lower limb segmental BIS (percentage difference range  =  1.06-12.09%, p  <  0.001). If wounds are present on the hands and/or wrist, then the alternate electrode position described in this study is valid, for whole body and upper limb segmental BIS.

Hepatitis E virus in patients with decompensated chronic liver disease: a prospective UK/French study

BACKGROUND

In developed countries, hepatitis E is a porcine zoonosis caused by hepatitis E virus (HEV) genotype 3. In developing countries, hepatitis E is mainly caused by genotype 1, and causes increased mortality in patients with pre-existing chronic liver disease (CLD).

AIM

To determine the role of HEV in patients with decompensated CLD.

METHODS

Prospective HEV testing of 343 patients with decompensated CLD at three UK centres and Toulouse France, with follow-up for 6 months or death. IgG seroprevalence was compared with 911 controls.

RESULTS

11/343 patients (3.2%) had acute hepatitis E infection, and three died. There were no differences in mortality (27% vs. 26%, OR 1.1, 95% CI 0.28-4.1), age (P = 0.9), bilirubin (P = 0.5), alanine aminotransferase (P = 0.06) albumin (P = 0.5) or international normalised ratio (P = 0.6) in patients with and without hepatitis E infection. Five cases were polymerase chain reaction (PCR) positive (genotype 3). Hepatitis E was more common in Toulouse (7.9%) compared to the UK cohort (1.2%, P = 0.003). HEV IgG seroprevalence was higher in Toulouse (OR 17, 95% CI 9.2-30) and Truro (OR 2.5, 95% CI 1.4-4.6) than in Glasgow, but lower in cases, compared to controls (OR 0.59, 95% CI 0.41-0.86).

CONCLUSIONS

Hepatitis E occurs in a minority of patients with decompensated chronic liver disease. The mortality is no different to the mortality in patients without hepatitis E infection. The diagnosis can only be established by a combination of serology and PCR, the yield and utility of which vary by geographical location.

Segmental colonic length and mobility

INTRODUCTION

Locoregional variation in the human colon is important in surgical practice; the length and mobility of different colonic regions impacts on laparoscopic and endoscopic colorectal procedures. The aim of this study was to refine anatomical understanding of the colon in terms of segmental length and mobility.

METHODS

The colons of 35 cadavers were examined to determine lengths of caecum as well as ascending, transverse, descending and rectosigmoid colon, and to characterise colonic mobility at each location in terms of the mesenteric attachments. The presence of Jackson's membrane (a congenital peritoneal band of the right colon) was also documented.

RESULTS

The mean total colonic length was 131.2cm (standard deviation [SD]: 13.4cm). There was no correlation with height, age or sex; the best predictor of total colonic length was the length of the rectosigmoid segment. The mean height of the transverse mesocolon was 7.4cm (SD: 3.6cm) and that of the sigmoid mesocolon was 6.3cm (SD: 2.6cm). Two-thirds of the subjects had a mobile portion of the ascending colon and nearly one-third had a mobile descending colon. A mobile ascending colon was significantly more common in females. Jackson's membrane was present in 66% of the subjects.

CONCLUSIONS

This cadaveric study suggests that rectosigmoid length accounts for most of the variability in total colonic length. The significant proportion of colons with mobility of the ascending and descending segments prompts revision of the traditional anatomical teaching of these segments as fixed and retroperitoneal. Mobility of the ascending colon may account for the anecdotal finding that colonoscopy is more challenging in female patients. Jackson's membrane was identified in most colons.

Towards more efficient burn care: Identifying factors associated with good quality of life post-burn

BACKGROUND

As minor burn patients constitute the vast majority of a developed nation case-mix, streamlining care for this group can promote efficiency from a service-wide perspective. This study tested the hypothesis that a predictive nomogram model that estimates likelihood of good long-term quality of life (QoL) post-burn is a valid way to optimise patient selection and risk management when applying a streamlined model of care.

METHOD

A sample of 224 burn patients managed by the Burn Service of Western Australia who provided both short and long-term outcomes was used to estimate the probability of achieving a good QoL defined as 150 out of a possible 160 points on the Burn Specific Health Scale-Brief (BSHS-B) at least six months from injury. A multivariate logistic regression analysis produced a predictive model provisioned as a nomogram for clinical application. A second, independent cohort of consecutive patients (n=106) was used to validate the predictive merit of the nomogram.

RESULTS AND DISCUSSION

Male gender (p=0.02), conservative management (p=0.03), upper limb burn (p=0.04) and high BSHS-B score within one month of burn (p<0.001) were significant predictors of good outcome at six months and beyond. A Receiver Operating Curve (ROC) analysis demonstrated excellent (90%) accuracy overall. At 80% probability of good outcome, the false positive risk was 14%. The nomogram was validated by running a second ROC analysis of the model in an independent cohort. The analysis confirmed high (86%) overall accuracy of the model, the risk of false positive was reduced to 10% at a lower (70%) probability. This affirms the stability of the nomogram model in different patient groups over time. An investigation of the effect of missing data on sample selection determined that a greater proportion of younger patients with smaller TBSA burns were excluded due to loss to follow up.

CONCLUSION

For clinicians managing comparable burn populations, the BSWA burns nomogram is an effective tool to assist the selection of patients to a streamlined care pathway with the aim of improving efficiency of service delivery.