Early-childhood body mass index and its association with the COVID-19 pandemic, containment measures and islet autoimmunity in children with increased risk for type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to determine whether BMI in early childhood was affected by the COVID-19 pandemic and containment measures, and whether it was associated with the risk for islet autoimmunity.

METHODS

Between February 2018 and May 2023, data on BMI and islet autoimmunity were collected from 1050 children enrolled in the Primary Oral Insulin Trial, aged from 4.0 months to 5.5 years of age. The start of the COVID-19 pandemic was defined as 18 March 2020, and a stringency index was used to assess the stringency of containment measures. Islet autoimmunity was defined as either the development of persistent confirmed multiple islet autoantibodies, or the development of one or more islet autoantibodies and type 1 diabetes. Multivariate linear mixed-effect, linear and logistic regression methods were applied to assess the effect of the COVID-19 pandemic and the stringency index on early-childhood BMI measurements (BMI as a time-varying variable, BMI at 9 months of age and overweight risk at 9 months of age), and Cox proportional hazard models were used to assess the effect of BMI measurements on islet autoimmunity risk.

RESULTS

The COVID-19 pandemic was associated with increased time-varying BMI (β = 0.39; 95% CI 0.30, 0.47) and overweight risk at 9 months (β = 0.44; 95% CI 0.03, 0.84). During the COVID-19 pandemic, a higher stringency index was positively associated with time-varying BMI (β = 0.02; 95% CI 0.00, 0.04 per 10 units increase), BMI at 9 months (β = 0.13; 95% CI 0.01, 0.25) and overweight risk at 9 months (β = 0.23; 95% CI 0.03, 0.43). A higher age-corrected BMI and overweight risk at 9 months were associated with increased risk for developing islet autoimmunity up to 5.5 years of age (HR 1.16; 95% CI 1.01, 1.32 and HR 1.68, 95% CI 1.00, 2.82, respectively).

CONCLUSIONS/INTERPRETATION

Early-childhood BMI increased during the COVID-19 pandemic, and was influenced by the level of restrictions during the pandemic. Controlling for the COVID-19 pandemic, elevated BMI during early childhood was associated with increased risk for childhood islet autoimmunity in children with genetic susceptibility to type 1 diabetes.

Graft-versus-host disease is locally maintained in target tissues by resident progenitor-like T cells

In allogeneic hematopoietic stem cell transplantation, donor αβ T cells attack recipient tissues, causing graft-versus-host disease (GVHD), a major cause of morbidity and mortality. A central question has been how GVHD is sustained despite T cell exhaustion from chronic antigen stimulation. The current model for GVHD holds that disease is maintained through the continued recruitment of alloreactive effectors from blood into affected tissues. Here, we show, using multiple approaches including parabiosis of mice with GVHD, that GVHD is instead primarily maintained locally within diseased tissues. By tracking 1,203 alloreactive T cell clones, we fitted a mathematical model predicting that within each tissue a small number of progenitor T cells maintain a larger effector pool. Consistent with this, we identified a tissue-resident TCF-1+ subpopulation that preferentially engrafted, expanded, and differentiated into effectors upon adoptive transfer. These results suggest that therapies targeting affected tissues and progenitor T cells within them would be effective.

Implementation of a treatment algorithm to decrease incidence of paralysis post endovascular thoracoabdominal aorta repair

BACKGROUND

Spinal cord ischemia (SCI) is a rare but devastating complication following aortic repair. Despite improvements in operative management and critical care of aortic disease patients, SCI remains one of the most serious and common complications after these procedures. Early recognition and rescue interventions can augment the outcome and reduce the morbidity or avoid permanent dysfunction. This is a single institution experience of creating an evidence-based algorithm for the treatment of SCI in patients after thoracoabdominal endovascular aortic repair (TEVAR).

INTERVENTION/METHODS

We implemented an evidence-based treatment algorithm for the management of acute SCI after TEVAR. A total of 131 TEVAR cases were reviewed, 59 cases preimplementation, and 72 cases postimplementation of an SCI treatment algorithm.

RESULTS

Lower extremity motor and/or sensory deficits were identified in 5.1% of preimplementation and 4.2% of postimplementation cases. SCI treatment interventions included increasing the mean arterial pressure (MAP) (66% pre and 100% post), placing lumbar drain (33% pre and 33% post), performing carotid subclavian bypass (33% pre and 33% post), initiating naloxone drip (66% pre and 100% post), and administering glipizide (0% pre and 100% post, P < .05). Long-term paralysis occurred in 66% of preimplementation and 0% of postimplementation cases.

CONCLUSIONS

By creating and implementing an SCI treatment algorithm we reduced both, time to detection and time to effective treatment of SCI and significantly improved our patients' neurological outcomes.

T cell exhaustion and a failure in antigen presentation drive resistance to the graft-versus-leukemia effect

In hematopoietic cell transplants, alloreactive T cells mediate the graft-versus-leukemia (GVL) effect. However, leukemia relapse accounts for nearly half of deaths. Understanding GVL failure requires a system in which GVL-inducing T cells can be tracked. We used such a model wherein GVL is exclusively mediated by T cells that recognize the minor histocompatibility antigen H60. Here we report that GVL fails due to insufficient H60 presentation and T cell exhaustion. Leukemia-derived H60 is inefficiently cross-presented whereas direct T cell recognition of leukemia cells intensifies exhaustion. The anti-H60 response is augmented by H60-vaccination, an agonist αCD40 antibody (FGK45), and leukemia apoptosis. T cell exhaustion is marked by inhibitory molecule upregulation and the development of TOX⁺ and CD39⁻TCF-1⁺ cells. PD-1 blockade diminishes exhaustion and improves GVL, while blockade of Tim-3, TIGIT or LAG3 is ineffective. Of all interventions, FGK45 administration at the time of transplant is the most effective at improving memory and naïve T cell anti-H60 responses and GVL. Our studies define important causes of GVL failure and suggest strategies to overcome them.

In hematopoietic stem cell transplants, T cells mediate graft-versus-leukemia (GVL), but GVL can fail leading to leukemia relapse. Here the authors use a mouse model in which T cells target the minor histocompatibility antigen H60 to show how this can occur, characterize the CD8⁺ T cell response and demonstrate how anti-CD40 antibody therapy improves GVL.

High prevalence of chronic venous disease among health care workers in the United States

BACKGROUND

Health care workers spend extended times standing and walking short distances and are at risk for development of chronic venous insufficiency (CVI). We conducted a hospital-wide venous screening program designed to measure the prevalence of and risk factors for clinical manifestations of CVI and ultrasound evidence of venous reflux or obstruction in health care workers. We also determined their risk for deep venous thrombosis (DVT).

METHODS

Free venous screening and education were offered to all hospital employees; the program started in April 2016, and results are presented from the first year. Demographics, medical history, and use of compression stockings were recorded. A physical examination determined the clinical class of the Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) classification for clinical disease, and an ultrasound test evaluated for reflux or obstruction in the common femoral vein, popliteal vein, and saphenofemoral junction. The Caprini score was recorded to evaluate risk of DVT. Descriptive statistics were reported, and logistic regression was used for multivariate analysis of risk factors.

RESULTS

We enrolled 636 participants (1272 legs); 93.0% were women. The median age was 42 years (interquartile range, 31-52 years), mean body mass index was 29.2 ± 6.6 kg/m2, and most participants were white (49.1%) or African American (39.5%); 18% reported having hypertension, 7.1% had diabetes, and 6.1% were current smokers. The majority reported occasional leg pain (72.7%) and evening leg swelling (42.3%). Only 2.7% used daily compression stockings. Clinical evidence of CVI was present in at least one leg in 69.1% (C1, 49.0%; C2, 17.7%; C3, 1.9%; C4, 0.2%; C5, 0.2%). Venous reflux was present in at least one leg in 82.1%; obstruction was rare (0.2%). Reflux in either the superficial (saphenofemoral junction) or the deep (femoral or popliteal) venous system was present in the majority (71.0%) of patients with CVI (clinical class ≥C1). Reflux and white race were risk factors for clinical disease; clinical disease, age, female sex, and white race were risk factors for reflux. On the basis of the Caprini score, 14.1% of participants were in the highest risk category for DVT when experiencing a high-risk situation (including 2.2% with history of DVT).

CONCLUSIONS

Prevalence of clinical CVI and venous reflux is high among health care workers despite a low frequency of cardiovascular comorbidities. Increased awareness about CVI and DVT and preventive strategies for venous disease must be instituted in this high-risk cohort.

Reduced length of stay and 30-day readmission rate on an inpatient vascular surgery service

As the cost of care for patients with specific diagnoses becomes fixed, hospitals must develop systems to reduce length of stay and optimize the use of hospital resources while maintaining a high quality of care. The goal of this study is to evaluate the implementation and efficacy of a system designed to reduce average length of stay on a vascular surgery service. To effectively reduce the average length of stay in our center, we restructured patient rounds, implemented multidisciplinary rounds, introduced clinical pathways to postoperative care, and expanded outpatient management of postoperative patients. A total of 1697 adult vascular surgery patients discharged while under the medical direction of a vascular surgeon between July 1, 2013, and June 30, 2016, were included in the study. Improving communication with critical staff and using procedural space outside of the main operating rooms led to a 2.8-day reduction in the length of stay (10.8 vs 8.0, P < .001). There was a trend toward a reduction in the 30-day readmission rate (12% vs 10%, respectively; P = .01) and no significant difference in the case-mix index as a measure of illness severity (2.5 vs 2.4, respectively; P = .15). Length of stay reductions were heterogeneous among the types of vascular diseases studied, with greater improvements seen in patients undergoing lower extremity amputation, lower extremity angiogram, and endovascular aneurysm repair for nonruptured abdominal aortic aneurysms. Less pronounced differences were observed in patients undergoing carotid artery endarterectomy or stenting and lower extremity bypasses. In conclusion, restructuring team rounds and instituting a multidisciplinary approach to discharge planning produced significant reductions in length of stay without a deleterious effect on patient care which may impact hospital profitability.

A mouse organotypic tissue culture model for autosomal recessive congenital ichthyosis

BACKGROUND

Autosomal recessive congenital ichthyoses (ARCIs) are keratinization disorders caused by impaired skin barrier function. Mutations in the genes encoding the lipoxygenases 12R-LOX and eLOX-3 are the second most common cause of ARCIs. In recent years, human skin equivalents recapitulating the ARCI phenotype have been established.

OBJECTIVES

To develop a murine organotypic tissue culture model for ARCI.

METHODS

Epidermal keratinocytes were isolated from newborn 12R-LOX-deficient mice and cocultivated with mouse dermal fibroblasts embedded in a scaffold of native collagen type I.

RESULTS

With this experimental set-up the keratinocytes formed a well-organized multilayered stratified epithelium resembling skin architecture in vivo. All epidermal layers were present and the keratinocytes within showed the characteristic morphological features. Markers for differentiation and maturation indicated regular epidermal morphogenesis. The major components of epidermal structures were expressed, and were obviously processed and assembled properly. In contrast to their wild-type counterparts, 12R-LOX-deficient skin equivalents showed abnormal vesicular structures in the upper epidermal layers correlating with altered lipid composition and increased transepidermal water loss, comparable with 12R-LOX-deficient mice.

CONCLUSIONS

The mouse skin equivalents faithfully recapitulate the 12R-LOX-deficient phenotype observed in vivo, classifying them as appropriate in vitro models to study molecular mechanisms involved in the development of ARCI and to evaluate novel therapeutic agents. In contrast to existing human three-dimensional skin models, the generation of these murine models is not constrained by a limited supply of material and does not depend on in vitro expansion and/or genetic manipulations that could result in inadvertent genotypic and phenotypic alterations.

Activated sludge rheology: a critical review on data collection and modelling

Rheological behaviour is an important fluid property that severely impacts its flow behaviour and many aspects related to this. In the case of activated sludge, the apparent viscosity has an influence on e.g. pumping, hydrodynamics, mass transfer rates, sludge-water separation (settling and filtration). It therefore is an important property related to process performance, including process economics. To account for this, rheological behaviour is being included in process design, necessitating its measurement. However, measurements and corresponding protocols in literature are quite diverse, leading to varying results and conclusions. In this paper, a vast amount of papers are critically reviewed with respect to this and important flaws are highlighted with respect to rheometer choice, rheometer settings and measurement protocol. The obtained rheograms from experimental efforts have frequently been used to build viscosity models. However, this is not that straightforward and a lot of errors can be detected with respect to good modelling practice, including fair model selection criteria, qualitative parameter estimations and proper model validation. These important steps are however recurrently violated, severely affecting the model reliability and predictive power. This is illustrated with several examples. In conclusion, dedicated research is required to improve the rheological measurements and the models derived from them. At this moment, there is no guidance with respect to proper rheological measurements. Moreover, the rheological models are not very trustworthy and remain very "black box". More insight in the physical background needs to be gained. A model-based approach with dedicated experimental data collection is the key to address this.

Principles of an enhanced MBR-process with mechanical cleaning

Up to date, different physical and chemical cleaning protocols are necessary to limit membrane fouling in membrane bioreactors. This paper deals with a mechanical cleaning process, which aims at the avoidance of hypochlorite and other critical chemicals in MBR with submerged flat sheet modules. The process basically consists of the addition of plastic particles into the loop circulation within submerged membrane modules. Investigations of two pilot plants are presented: Pilot plant 1 is equipped with a 10 m(2) membrane module and operated with a translucent model suspension; pilot plant 2 is equipped with four 50 m(2) membrane modules and operated with pretreated sewage. Results of pilot plant 1 show that the establishment of a fluidised bed with regular particle distribution is possible for a variety of particles. Particles with maximum densities of 1.05 g/cm(3) and between 3 and 5 mm diameter form a stable fluidised bed almost regardless of activated sludge concentration, viscosity and reactor geometry. Particles with densities between 1.05 g/cm(3) and 1.2 g/cm(3) form a stable fluidised bed, if the velocity at the reactor bottom is sufficiently high. Activities within pilot plant 2 focused on plant optimisation and the development of an adequate particle retention system.

Impact of colloidal and soluble organic material on membrane performance in membrane bioreactors for municipal wastewater treatment

Two parallel membrane bioreactors (2 m3 each) were operated over a period of 2 years. Both pilots were optimised for nitrification, denitrification, and enhanced biological phosphorous elimination, treating identical municipal wastewater under comparable operating conditions. The only constructional difference between the pilots was the position of the denitrification zone (pre-denitrification in pilot 1 and post-denitrification in pilot 2). Despite identical modules and conditions, the two MBRs showed different permeabilities and fouling rates. The differences were not related to the denitrification scheme. In order to find an explanation for the different membrane performances, a one-year investigation was initiated and the membrane performance as well as the operating regime and characteristics of the activated sludge were closely studied. MLSS concentrations, solid retention time, loading rates, and filtration flux were found not to be responsible for the different performance of the submerged modules. These parameters were kept identical in the two pilot plants. Instead, the non-settable fraction of the sludges (soluble and colloidal material, i.e. polysaccharides, proteins and organic colloids) was found to impact fouling and to cause the difference in membrane performance between the two MBR. This fraction was analysed by spectrophotometric and size exclusion chromatography (SEC) methods. In a second step, the origin of these substances was investigated. The results point to microbiologically produced substances such as extracellular polymeric substances (EPS) or soluble microbial products (SMP).

Correlation between membrane fouling and soluble/colloidal organic substances in membrane bioreactors for municipal wastewater treatment

Two similar membrane bioreactors of 2 m3 each were operated in parallel over two years under the same operational conditions, fed with the same municipal wastewater. The only process and operational difference between both pilot plants was the position of the denitrification zone (pre-denitrification in pilot 1 and post-denitrification in pilot 2). Despite parallel operation, the two MBRs exhibited different fouling rates and decreases in permeability. These differences could not be accounted for by MLSS concentrations, loading rates, or filtration flux. In a one-year investigation, soluble and colloidal organic material in the activated sludge of both MBR was regularly analysed by spectrophotometric and Size Exclusion Chromatography (SEC) methods. The larger organic molecules present in the sludge water phase (i.e. polysaccharides, proteins and organic colloids) originating from microbial activity (extracellular polymeric substances) were found to impact on the fouling and to explain the difference in membrane performance between the two MBR units. In both pilot plants, a linear relationship could be clearly demonstrated between the fouling rate of the membrane and the concentration of polysaccharides in the sludge water phase during a 5 month operational period at an SRT of 8 days.

Performance of a bioreactor with submerged membranes for aerobic treatment of municipal waste water

Aerobic treatment of municipal waste water in a membrane bioreactor was studied for 535 d. Apart from sampling, sludge was retained completely by a submerged hollow fibre membrane with a pore-size of 0.2 microm. The pilot plant comprised an anoxic zone to enable denitrification. The maximum liquid hold-up of the plant was 3.9 m3. In this study the reactor performance and the stability of the process and the membrane capacity were investigated. A stable flux of 181 m(-2)h(-1) could be realised with a mean transmembrane pressure difference of 0.3bar with air-bubbling and backflushing the membrane and cleaning it in place every two months for one or two hours. For about 140d, a flux of 271 m(-2)h(-1) was achieved, but cleaning became necessary more often. The hydraulic retention time (HRT) varied between 10.4 and 15.6h. Accordingly the volumetric loading rate was between 1.1 and 1.7kg CODm(-3)d(-1). No inoculum was used. The mixed liquor suspended solids (MLSS) concentration gradually increased to 18-20g MLSSl(-1). The feed to microorganism (F/M) ratio varied according to the operation conditions but decreased against a value of 0.07 kg COD kg(-1) MLSSd(-1). Treatment performance was very stable and on a high level. The COD was reduced by 95%. Nitrification was complete and up to 82% of the total nitrogen could be denitrified.

New genotypes in Fy(a-b-) individuals: nonsense mutations (Trp to stop) in the coding sequence of either FY A or FY B

Duffy blood group antigens are carried on a glycoprotein that is predicted to pass through the erythrocyte membrane seven times and is a promiscuous chemokine receptor. The Fy(a- b-) phenotype is present in two-thirds of African-American Blacks but is rare in Caucasians. In Blacks, the phenotype is due to a non-functional GATA-1 motif in the FY B, which silences the gene in erythrocytes but not in other tissues, and these patients do not generally make anti-Fyb or anti-Fy3. We describe here the molecular analysis of FY in three unrelated Caucasians who were studied because they had strong anti-Fy3 in their serum. Each was found to have a point mutation that was predicted to change a tryptophan to a premature stop codon in the coding sequence. In one patient (patient 1), the nonsense mutation was at nucleotide 287 of the major transcript in FY A; in another (patient 2), it was at nucleotide 407 in the major transcript of FY B; and in a third (patient 3), it was at nucleotide 408 of the major transcript of FY A.