Radiation Therapy Sensitizes Head-and-Neck Cancer Cells to Killing by Chimeric Antigen Receptor (CAR)-NK Cells Targeting CD70

PURPOSE/OBJECTIVE(S)

CAR-T cell therapy is limited by toxicity, high cost, logistical manufacturing issues in the autologous setting and risk of GVHD in the allogeneic setting. Substitution of T cells with NK cells opens the possibility for an allogeneic off-the-shelf product with a better safety profile. However, the inadequate efficacy of CAR-NK cells against solid tumors can be extrapolated from experience with CAR-T cells. There is limited but promising preclinical evidence that radiation therapy (RT) enhances CAR-T cell tumoricidal activity against solid tumors. However, there is no data examining the potential synergy between RT and CAR-NK cell therapy.

MATERIALS/METHODS

We engineered CAR-NK cells with CD27 receptor as extracellular domain to target its natural ligand CD70, which is overexpressed in head-and-neck cancers (HNSCC). CAR-NK cell killing was assessed real-time through xCELLigence cytotoxicity assays. CD70+ OQ01 human HNSCCs were used for most experiments. FaDu is a CD70- HNSCC (negative ctrl). UMRC3 is a CD70+ kidney cancer cell line (positive ctrl). CD70 expression pre- and post-RT was assessed by flow cytometry and Western blot. Ionizing RT was compared at 5 doses: 0, 1.75, 3.5, 7, and 14 Gy. A single dose of 3.5 Gy was used for most experiments. Post-radiation effects were generally assessed at 3 days or 9 days post-RT. Intracellular staining was used to assess NK cell expression of IFN-γ, CD107a, and TNF-α by flow cytometry. CD27/CD70 interaction blockade was through α-CD27 pre-treatment of CAR-NK cells.

RESULTS

OQ01 HNSCCs heterogeneously express CD70 and are killed by CD70 CAR-NK cells in vitro. Pre-conditioning low-dose RT of 3.5 Gy applied to OQ01 HNSCCs 3 days prior to coculture with NK cells enhances CD70 CAR-NK cell killing, with ∼30% increased cytotoxicity against the tumor cells. Low-dose RT by itself did not induce acute cytolysis. As a possible mechanism for the increased sensitivity of irradiated OQ01 cells to CD70 CAR-NK cells, we found that RT enhances CD70 expression among HNSCCs in a dose-dependent manner. There was no increase in NK cell expression of IFN-γ, CD107a, and TNF-α with exposure to irradiated target cells. CD27/CD70 blockade does not solely abrogate RT-induced sensitization toward CAR-NK cell killing. Despite RT induction of transient increased expression of CD70, which normalizes by 9 days post-RT, there is persistent increase in RT-synergized target cell killing even at this later timepoint. Thus, altogether, RT sensitizes CD70-expressing HNSCC cells to CAR-NK cell killing in vitro.

CONCLUSION

This work represents the first preclinical study to identify the synergy of RT and CAR-NK cell therapy in solid tumors and is the first demonstration of CAR-NK cell activity against human HNSCCs. We show significantly enhanced potency of CAR-NK cells against irradiated tumor cells in vitro. Collectively, this research will be vital to guide efforts expanding into other target antigens and tumor types.

Morphological remodeling of Coxiella burnetii during its biphasic developmental cycle revealed by cryo-electron tomography

Coxiella burnetii is an obligate zoonotic bacterium that targets macrophages causing a disease called Q fever. It has a biphasic developmental life cycle where the extracellular and metabolically inactive small cell variant (SCV) transforms inside the host into the vegetative large cell variant (LCV). However, details about the morphological and structural changes of this transition are still lacking. Here, we used cryo-electron tomography to image both SCV and LCV variants grown either under axenic conditions or purified directly from host cells. We show that SCVs are characterized by equidistant stacks of inner membrane that presumably facilitate the transition to LCV, a transition coupled with the expression of the Dot/Icm type IVB secretion system (T4BSS). A class of T4BSS particles were associated with extracellular densities possibly involved in host infection. Also, SCVs contained spherical multilayered membrane structures of different sizes and locations suggesting no connection to sporulation as once assumed.

Bdellovibrio predation cycle characterized at nanometre-scale resolution with cryo-electron tomography

Bdellovibrio bacteriovorus is a microbial predator that offers promise as a living antibiotic for its ability to kill Gram-negative bacteria, including human pathogens. Even after six decades of study, fundamental details of its predation cycle remain mysterious. Here we used cryo-electron tomography to comprehensively image the lifecycle of B. bacteriovorus at nanometre-scale resolution. With high-resolution images of predation in a native (hydrated, unstained) state, we discover several surprising features of the process, including macromolecular complexes involved in prey attachment/invasion and a flexible portal structure lining a hole in the prey peptidoglycan that tightly seals the prey outer membrane around the predator during entry. Unexpectedly, we find that B. bacteriovorus does not shed its flagellum during invasion, but rather resorbs it into its periplasm for degradation. Finally, following growth and division in the bdelloplast, we observe a transient and extensive ribosomal lattice on the condensed B. bacteriovorus nucleoid.

Prognostic role of intermountain risk score (IMRS) in intensive care unit patients with a diagnosis of COVID-19

OBJECTIVE

In this study, we aimed to assess the predictive value of Intermountain Risk Score (IMRS) in intensive care unit (ICU) patients with COVID-19.

PATIENTS AND METHODS

Our retrospective study included the data of 194 patients who were admitted to the COVID-19 ICU of a tertiary care center. COVID-19 diagnoses were made by a positive result from a real-time reverse-transcriptase (RT) polymerase chain reaction (PCR) assay of nasal and pharyngeal swab specimens. Patients who had negative RT-PCR results or who were not admitted to ICU and patients under 18 years old were excluded from the study. Complete blood count, biochemistry panel, and blood gas analysis results were gathered and compiled.

RESULTS

194 ICU patients with COVID-19 (PCR positive) were included in the study. The patients were divided into two groups according to IMRS (if IMRS was <15 in women and <17 in men, patients were included in the non-high-risk group, while patients with IMRS ≥15 in women and ≥17 in men were defined as a high-risk group). Multivariate regression analysis was performed to predict in-hospital mortality. The IMRS [OR: 1.17 (1.08-1.27) p<0.001)] was found to predict in-hospital mortality.

CONCLUSIONS

In this study, we showed that the IMRS score at admission can predict in-hospital mortality in intensive care unit patients with a diagnosis of COVID-19.

Association between Kelch-like ECH-associated protein-1 and GRACE risk score in non-ST elevation myocardial infarction

OBJECTIVE

In this study, we measured the levels of Kelch-like ECH-associated protein 1 (KEAP1), which has the potential antioxidant capacity, among non-ST elevation myocardial infarction (NSTEMI) patients compared with healthy controls. We also investigated the possible association between KEAP1 levels and the GRACE score, which is a universal risk score commonly used for patients with acute myocardial infarction.

PATIENTS AND METHODS

As the patient group, 78 patients admitted to our center with a diagnosis of NSTEMI were included in the study. As the control group, 77 individuals found to have normal coronary arteries after coronary arteriography were included (155 patients in total). GRACE risk scores and left ventricular ejection fractions (LVEFs) were calculated, KEAP1 levels were measured, and the usual blood tests were performed.

RESULTS

KEAP1 levels were significantly higher among the NSTEMI patients compared to the healthy control group (671.1 ± 120.7 vs. 262.7 ± 105.7, p < 0.001). We also found a moderate positive correlation between KEAP1 levels and GRACE risk scores among patients with NSTEMI (r = +0.521, p < 0.001). Additionally, a negative correlation between KEAP1 levels and LVEFs was detected (r = -0.264, p < 0.001).

CONCLUSIONS

Elevated KEAP1 levels have the potential to be used as a risk factor for NSTEMI in terms of clinical adverse events and poor prognosis at admission.

Structure and Assembly of the Proteus mirabilis Flagellar Motor by Cryo-Electron Tomography

Proteus mirabilis is a Gram-negative Gammaproteobacterium and a major causative agent of urinary tract infections in humans. It is characterized by its ability to switch between swimming motility in liquid media and swarming on solid surfaces. Here, we used cryo-electron tomography and subtomogram averaging to reveal the structure of the flagellar motor of P. mirabilis at nanometer resolution in intact cells. We found that P. mirabilis has a motor that is structurally similar to those of Escherichia coli and Salmonella enterica, lacking the periplasmic elaborations that characterize other more specialized gammaproteobacterial motors. In addition, no density corresponding to stators was present in the subtomogram average suggesting that the stators are dynamic. Finally, several assembly intermediates of the motor were seen that support the inside-out assembly pathway.

POS1245 REVERSAL OF DECLINE IN HUMORAL RESPONSE TO BNT162b2 mRNA COVID-19 VACCINE AFTER BOOSTER ADMINISTRATION IN AUTOIMMUNE INFLAMMATORY RHEUMATOID DISEASES (AIRD) PATIENTS

Background

Previous studies proved that mRNA vaccinations against SARS CoV2 induced significant humoral responses in AIRD patients (pts). However, the humoral response was blunted in pts treated with CD20 depleting antibodies. There are limited data regarding the long-term outcome of the humoral response and the contribution of the booster vaccine, in immunosuppressed AIRD pts.

Objectives

To assess the long-term outcome of the humoral response to mRNA vaccine against SARS CoV2, in AIRD pts treated with immunomodulating drugs, and the contribution of the booster vaccination.

Methods

Consecutive pts treated at the Rheumatology Institute at Rambam Hospital who received their first SARS-CoV-2 (Pfizer) vaccine were recruited to the study, at their routine visit. The visit included AIRD activity assessment and questioning regarding vaccine side effects. We performed serology test 4-6 weeks and 24 weeks after receiving the second dose of vaccine. Pts who received the booster (3rd vaccine) were invited for serology tests 4-8 weeks afterwards. The immunomodulating treatment was not modified, either before or after the vaccination. IgG Antibodies (Ab) against SARS COV2 virus were detected using the SARS-Cov-2 IgG II Quant (Abbott) assay based on a chemiluminescent microparticle immunoassay (CMIA) on the ARCHITECT ci8200system from Abbott. This assay is measuring IgG antibodies against the spike receptor-binding domain (S-RBD) of the virus. The test was considered positive above 50 AU/ml.

Results

262 pts (mean age(SD) 57(13), disease duration 11.2(7.4), were recruited. The cohort included 152 pts with inflammatory joint disease, 26 pts with systemic lupus erythematosus, 62 pts with other connective tissue disease and 22 pts with vasculitis; 27 % received csDMARDs only, 35% - b/tsDMARDs only, 30% - combined therapy (csDMARDs+b/tsDMARDs) and 26% received steroids. 225 pts (86%) were seropositive for IgG Ab against SARS CoV2 virus (median 2832.5 AU/ml, IQR 58-29499). 37 (14%) pts had negative tests, 23 (62.2%) of them were rituximab treated.

The IgG levels correlated with the medication used to treat the AIRD, the patients’ age but not with the type of the AIRD (Figure 1). 24 weeks afterwards, the median IgG level dropped to 282 AU/ml and 15% of the pts with previous seropositive tests became negative. The booster administration (Pfizer) significantly augmented the humoral response (median 8328 AU/ml, IQR 375-40000). De novo serologic response was observed in 10 out of 37 pts (4/23 rituximab treated pts).

Figure 1.

The reported side effects of the vaccine were minor (muscle sore, headache, low grade fever). The AIRD remained stable in all pts following all three vaccinations.

Conclusion

Although the vast majority of AIRD pts developed a substantial humoral response following the administration of the second dose of the Pfizer mRNA vaccine against SARS CoV2 virus, the humoral response significantly declined 24 weeks afterwards. An enhanced response was obtained after the third booster vaccination. Only minor side effects were reported and no apparent impact on AIRD activity was noted. Notably, 62% of the non-responders were treated with B cell depleting agents.

Acknowledgements

We would like to thank Mrs Tsofnat Margi and Mrs Sarit Elkouby for organisational support.

Disclosure of Interests

None declared

Novel transient cytoplasmic rings stabilize assembling bacterial flagellar motors

The process by which bacterial cells build their intricate flagellar motility apparatuses has long fascinated scientists. Our understanding of this process comes mainly from studies of purified flagella from two species, Escherichia coli and Salmonella enterica. Here, we used electron cryo-tomography (cryo-ET) to image the assembly of the flagellar motor in situ in diverse Proteobacteria: Hylemonella gracilis, Helicobacter pylori, Campylobacter jejuni, Pseudomonas aeruginosa, Pseudomonas fluorescens, and Shewanella oneidensis. Our results reveal the in situ structures of flagellar intermediates, beginning with the earliest flagellar type III secretion system core complex (fT3SScc) and MS-ring. In high-torque motors of Beta-, Gamma-, and Epsilon-proteobacteria, we discovered novel cytoplasmic rings that interact with the cytoplasmic torque ring formed by FliG. These rings, associated with the MS-ring, assemble very early and persist until the stators are recruited into their periplasmic ring; in their absence the stator ring does not assemble. By imaging mutants in Helicobacter pylori, we found that the fT3SScc proteins FliO and FliQ are required for the assembly of these novel cytoplasmic rings. Our results show that rather than a simple accretion of components, flagellar motor assembly is a dynamic process in which accessory components interact transiently to assist in building the complex nanomachine.

A rare tumor case in an adult patient with neurofibromatosis: Lumbar ependymoma

In patients with type 1 neurofibromatosis (NF1), there is an increased susceptibility to tumor development in the central nervous system due to the loss of neurofibromin, an inactivator of the protooncogene Ras. NF1 has a broad clinical spectrum,which includes spinal tumors. Although the most common intramedullary tumor of the spinal cord in adults is ependymoma, few patients with NF1 accompanied by spinal ependymoma have been reported to date, and the localization of the tumors is cervical and thoracic in these cases. In this study, we report the case of a patient with NF1 presenting to our clinic with low back pain and gait disturbance. The patient had an intradural extramedullary ependymoma at the L2-3 vertebra level. This report is the first case of NF1 with spinal ependymoma localized in the lumbar region.

In situ imaging of bacterial outer membrane projections and associated protein complexes using electron cryo-tomography

The ability to produce outer membrane projections in the form of tubular membrane extensions (MEs) and membrane vesicles (MVs) is a widespread phenomenon among diderm bacteria. Despite this, our knowledge of the ultrastructure of these extensions and their associated protein complexes remains limited. Here, we surveyed the ultrastructure and formation of MEs and MVs, and their associated protein complexes, in tens of thousands of electron cryo-tomograms of ~90 bacterial species that we have collected for various projects over the past 15 years (Jensen lab database), in addition to data generated in the Briegel lab. We identified outer MEs and MVs in 13 diderm bacterial species and classified several major ultrastructures: (1) tubes with a uniform diameter (with or without an internal scaffold), (2) tubes with irregular diameter, (3) tubes with a vesicular dilation at their tip, (4) pearling tubes, (5) connected chains of vesicles (with or without neck-like connectors), (6) budding vesicles and nanopods. We also identified several protein complexes associated with these MEs and MVs which were distributed either randomly or exclusively at the tip. These complexes include a secretin-like structure and a novel crown-shaped structure observed primarily in vesicles from lysed cells. In total, this work helps to characterize the diversity of bacterial membrane projections and lays the groundwork for future research in this field.

Potential role of the geriatric nutritional risk index as a novel risk factor for the development of non-valvular atrial fibrillation in patients with heart failure

PURPOSE

The geriatric nutritional risk index (GNRI) is a simple and objective nutritional assessment tool for elderly patients. Lower GNRI values are associated with a worse prognosis in heart failure with reduced ejection fraction (HFrEF). Our aim is to investigate the relationship between malnutrition and follow-up cardiovascular (CV) events in HFrEF.

METHODS

A retrospective study was performed on 362 patients with HFrEF. The baseline GNRI was calculated at the first visit. The patients were divided into three groups according to the GNRI: >98, no-risk group; 92 to ≤98, low risk group; 82 to <92, moderate‑to‑high‑risk group. The study endpoint was a composite of follow-upCV events, including all-cause mortality, non-valvular atrial fibrillation (NVAF) , need for cardioverter defibrillator (ICD) therapy, HfrEF‑related hospitalizations and need for percutaneous coronary interventions (PCIs).

RESULTS

Follow-up data showed that the group with moderate-to-high risk had a significantly higher incidence of NVAF, PCIs and all-cause mortality compared to other groups (p<0.001, p: 0.026 and p0.05). Mean GNRI value was 83.3 in NVAF patients and 101.1 in patients without NVAF (p<0.001). Kaplan Meier survival analysis showed that patients from the group with moderate-to-high risk had a significantly worse survival rate (p < 0.001). In the multivariate Cox regression analysis, the group with moderate-to‑high risk (HR=3.872) and ICD implantations (HR=4.045) were associated with increased mortality.

CONCLUSION

The GNRI value may have a potential role for predicting future events, especially NVAF in patients with HfrEF (Tab. 4, Fig. 2, Ref. 27).

Erratum: Azimuthal Anisotropy of K_{S}^{0} and Λ+Λ[over ¯] Production at Midrapidity from Au+Au Collisions at sqrt[s]_{NN}=130 GeV [Phys. Rev. Lett. 89, 132301 (2002)]

This corrects the article DOI: 10.1103/PhysRevLett.89.132301.

Erratum: Azimuthal Anisotropy at the Relativistic Heavy Ion Collider: The First and Fourth Harmonics [Phys. Rev. Lett. 92, 062301 (2004)]

This corrects the article DOI: 10.1103/PhysRevLett.92.062301.

Programmed Flagellar Ejection in Caulobacter crescentus Leaves PL-subcomplexes

The bacterial flagellum consists of a long extracellular filament that is rotated by a motor embedded in the cell envelope. While flagellar assembly has been extensively studied,¹ the disassembly process remains less well understood. In addition to the programmed flagellar ejection that occurs during the life cycle of Caulobacter crescentus, we and others have recently shown that many bacterial species lose their flagella under starvation conditions, leaving relic structures in the outer membrane.^2-7 However, it remains unknown whether the programmed flagellar ejection of C. crescentus leaves similar relics or not. Here, we imaged the various stages of the C. crescentus life cycle using electron cryo-tomography (cryo-ET) and found that flagellar relic subcomplexes, akin to those produced in the starvation-induced process, remain as a result of flagellar ejection during cell development. This similarity suggests that the programmed flagellar ejection of C. crescentus might share a common evolutionary path with the more general, and likely more ancient,³ starvation-related flagellar loss.

In Situ Imaging and Structure Determination of Biomolecular Complexes Using Electron Cryo-Tomography

Electron cryo-tomography (cryo-ET) is a technique that allows the investigation of intact macromolecular complexes while they are in their cellular milieu. Over the years, cryo-ET has had a huge impact on our understanding of how large biomolecular complexes look like, how they assemble, disassemble, function, and evolve(d). Recent hardware and software developments and combining cryo-ET with other techniques, e.g., focused ion beam milling (FIB-milling) and cryo-light microscopy, has extended the realm of cryo-ET to include transient molecular complexes embedded deep in thick samples (like eukaryotic cells) and enhanced the resolution of structures obtained by cryo-ET. In this chapter, we will present an outline of how to perform cryo-ET studies on a wide variety of biological samples including prokaryotic and eukaryotic cells and biological plant tissues. This outline will include sample preparation, data collection, and data processing as well as hybrid approaches like FIB-milling, cryosectioning, and cryo-correlated light and electron microscopy (cryo-CLEM).

Effects of antimicrobial photodynamic therapy on antibiotic-resistant Escherichia coli

This study used Electron Cryo-tomography (ECT) and fluorescent images to evaluate antimicrobial photodynamic therapy (aPDT) on the envelope architecture of a Gram-negative bacteria and the effects of combined therapy of aPDT and antibiotics. Standard and clinical suspension of Escherichia coli were submitted to photodynamic treatment with methylene blue solution (100μM) and a 100 mW LED emitting at 660 nm with 3 and 18 J of energy. As a control group, a suspension of E. coli was submitted to penicillin V for 60 min at 30 °C, to compare the damage in cell wall structure. After treatment, ECT images were collected and E. coli biofilms were grown in glass-cover slides and stained with live/dead staining for fluorescence analysis before and after treatments. Bacteria were also submitted to disc diffusion and MIC₅₀ tests with Ampicillin, Amoxicillin + Clavulanic acid, Clindamycin and Erythromycin. For in vivo experiment Galleria mellonella larvae were infected with E. coli and treated with antibiotics, aPDT or combined therapy. ECT images presented damage to cell walls and vesicles structures inside and outside the bacteria and fluorescent images showed dose dependent effect of aPDT. Antibiotic or aPDT alone did not improve the survival of caterpillars, but the combined therapy significantly increased survival curve. ECT and fluorescent images shows that aPDT seems to promote micro-damages to cell envelope and causes the production of membrane vesicles permeabilizing cell membranes. The results showed that pre-treating bacterial cells with a photosensitizer and light make them more susceptible to antibiotics and could be an alternative to local infection treatment by resistant bacteria.

3D evaluation of tooth crown size ın unilateral cleft lip and palate patients

Aim

The aim of this retrospective study is to evaluate and compare the 3-dimensional (3D) crown sizes of the left and right sides of upper and lower dental arches in patients with unilateral cleft lip and palate (UCLP).

Materials and Methods

Dental casts of 94 patients all in permanent dentition were included in this study. Dental casts were divided into three groups as 36 casts with unilateral left cleft lip and palate (ULCLP), 18 casts with unilateral right cleft lip and palate (URCLP), and 40 casts without cleft (control). Mesiodistal (MD), buccolingual (BL), and gingiva incisal (GI) values of each tooth were measured by scanning the dental models with a high-precision optical 3D scanner. Paired t-test and independent t-test were used for statistical analysis.

Results

U1 MD, U6 MD (P = 0.001) and BL (P = 0.01), L3 GI (P = 0.05) were greater in UCLP patients on the non-cleft side while U1 GI, L1 BL, L5 MD (P = 0.001), L4 MD, and BL (P = 0.01) values were found to be greater on the cleft side. Comparison of the cleft-sides and the control group showed that MD, BL, and GI dimensions of teeth on the cleft sides were generally found to be smaller, excluding the UR7 GI values for URCLP group (P = 0.05).

Conclusion

In the measurements of teeth size, reliable and repeatable results were acquired through 3D software. Tooth size asymmetries can occur non-syndromic UCLP patients in both jaws. MD, BL, and GI dimensions of teeth are mostly found to be smaller in patients with CLP.

Diagnostic utility of oxidative and non-oxidative markers for spontaneous bacterial peritonitis in non-malign ascites

OBJECTIVE

In this study, we aimed to investigate the diagnostic availability of oxidant and antioxidant parameters in ascites for spontaneous bacterial peritonitis (SBP).

MATERIAL AND METHODS

This study was carried out between July and October 2018 with 25 patients with SBP and 24 patients without SBP. Patients with acute infection, those taking vitamin supplements and antioxidant medication, smoking and drinking alcohol, and patients without ascites culture were excluded from the study.

RESULTS

In patients with SBP compared those without SBP median paraoxonase (3.1 vs 15.6 ; p <0.001), median stimulated paraoxonase (12.6 vs 53.1 ; p <0.001), median arylesterase (769,9 vs 857,5 ; p = 0,003) and median catalase (10 vs 22,2 ; p = 0,003) were found to be lower and median myeloperoxidase (8.1 vs 1.1 ; p <0.001) were found to be higher. There was a positive correlation between paraoxonase levels and stimulated paraoxonase levels, arylesterase levels and catalase levels, there was a negative correlation between paraoxonase levels and myeloperoxidase levels. Paraoxonase levels 3.7 and lower, stimulated paraoxonase levels 25.8 and lower, arylesterase levels 853.4 and lower, catalase levels 11.8 and lower and myeloperoxidase levels 2.7 and more predicted the the presence of SBP with high specificity and high sensitivity. Paraoxonase and stimulated paraoxo-nase levels were found to have superior performance in predicting the presence of SBP compared to arylesterase levels (p <0.05).

CONCLUSION

In this study it was shown that paraoxonase, stimulated paraoxonase, arylesterase, catalase and myeloperoxidase activities can be used for the diagnosis and severity of SBP.

Monocyte/HDL ratio predicts hypertensive complications

OBJECTIVE

We aimed to investigate whether a simple and easily calculated parameter such as monocyte/ HDL ratio (MHR) may be used in predicting non-dipper (NDHT)-dipper HT (DHT) end organ damage.

METHODS

70 NDHT and 73 DHT patient groups were included in the study according to ambulatory blood pressure screening results. Basic laboratory parameters and spot urine samples were evaluated. Transthoracic echocardiography and ophthalmological examination were performed for end-organ damages.

RESULTS

The MHR among the groups was higher in the NDHT group; which was statistically significant (p≤0.001). In the NDHT group, albumin, creatinine, protein values, protein/creatinine ratio in the spot urine were significantly higher than in the DHT group (p≤0.05). Left ventricular hypertrophy (LVH) and retinopathy were also more frequently observed in the NDHT group (p≤0.001 and p=0.001, respectively). MHR in patients with LVH and retinopathy was significantly higher than in those without these complications (p=0.001).

CONCLUSION

Easy to use, non-invasive and simple calculation, MHR can be used to predict end organ damage in hypertensive cases, and can be also used to distinguish between DHT/NDHT groups. This data supports the role of inflammation (Tab. 7, Ref. 14).

Publisher Correction: In vivo structure of the Legionella type II secretion system by electron cryotomography

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

In vivo structure of the Legionella type II secretion system by electron cryotomography

The type II secretion system (T2SS) is a multiprotein envelope-spanning assembly that translocates a wide range of virulence factors, enzymes and effectors through the outer membrane of many Gram-negative bacteria1-3. Here, using electron cryotomography and subtomogram averaging methods, we reveal the in vivo structure of an intact T2SS imaged within the human pathogen Legionella pneumophila. Although the T2SS has only limited sequence and component homology with the evolutionarily related type IV pilus (T4P) system4,5, we show that their overall architectures are remarkably similar. Despite similarities, there are also differences, including, for example, that the T2SS-ATPase complex is usually present but disengaged from the inner membrane, the T2SS has a much longer periplasmic vestibule and it has a short-lived flexible pseudopilus. Placing atomic models of the components into our electron cryotomography map produced a complete architectural model of the intact T2SS that provides insights into the structure and function of its components, its position within the cell envelope and the interactions between its different subcomplexes.

In situ imaging of the bacterial flagellar motor disassembly and assembly processes

The self-assembly of cellular macromolecular machines such as the bacterial flagellar motor requires the spatio-temporal synchronization of gene expression with proper protein localization and association of dozens of protein components. In Salmonella and Escherichia coli, a sequential, outward assembly mechanism has been proposed for the flagellar motor starting from the inner membrane, with the addition of each new component stabilizing the previous one. However, very little is known about flagellar disassembly. Here, using electron cryo-tomography and sub-tomogram averaging of intact Legionella pneumophila, Pseudomonas aeruginosa, and Shewanella oneidensis cells, we study flagellar motor disassembly and assembly in situ. We first show that motor disassembly results in stable outer membrane-embedded sub-complexes. These sub-complexes consist of the periplasmic embellished P- and L-rings, and bend the membrane inward while it remains apparently sealed. Additionally, we also observe various intermediates of the assembly process including an inner-membrane sub-complex consisting of the C-ring, MS-ring, and export apparatus. Finally, we show that the L-ring is responsible for reshaping the outer membrane, a crucial step in the flagellar assembly process.

Prolactin levels in drug-naïve first episode nonaffective psychosis patients compared with healthy controls. Sex differences

Recent studies have found hyperprolactinemia in first episode psychotic patients that had not previously received antipsychotic treatment (drug-naïve). Our goal was to learn whether there were differences in baseline prolactin concentrations between drug-naïve psychotic patients and healthy controls, as well as to study possible gender differences in the prolactin elevation. A cross-sectional study was conducted that included 61 drug-naïve psychosis patients and 45 healthy controls (aged between 14-55 years old). A blood sample was extracted between 8 and 10 a.m. Prolactin levels and TSH were determined. The Perceived Stress Scale (PSS) was conducted across the sample. This study showed significantly higher levels of prolactin in drug-naïve patients compared to healthy controls. These results were maintained after controlling prolactin levels for sex, age, THC consumption, baseline TSH, and PSS. A significant correlation between prolactin and PSS was not observed. Significant differences in prolactin levels between men and women were not observed. These results are clinically important because if elevated baseline prolactin levels are detected in these patients, it will be necessary to initiate neuroleptics that do not increase this hormone. There was no evidence that stress was related to an increase in prolactin at the onset of psychosis.

Simulations suggest a constrictive force is required for Gram-negative bacterial cell division

To divide, Gram-negative bacterial cells must remodel cell wall at the division site. It remains debated, however, whether this cell wall remodeling alone can drive membrane constriction, or if a constrictive force from the tubulin homolog FtsZ is required. Previously, we constructed software (REMODELER 1) to simulate cell wall remodeling during growth. Here, we expanded this software to explore cell wall division (REMODELER 2). We found that simply organizing cell wall synthesis complexes at the midcell is not sufficient to cause invagination, even with the implementation of a make-before-break mechanism, in which new hoops of cell wall are made inside the existing hoops before bonds are cleaved. Division can occur, however, when a constrictive force brings the midcell into a compressed state before new hoops of relaxed cell wall are incorporated between existing hoops. Adding a make-before-break mechanism drives division with a smaller constrictive force sufficient to bring the midcell into a relaxed, but not necessarily compressed, state.

Single- versus double-layer closure of the caesarean (uterine) scar in the prevention of gynaecological symptoms in relation to niche development - the 2Close study: a multicentre randomised controlled trial

BACKGROUND

Double-layer compared to single-layer closure of the uterus after a caesarean section (CS) leads to a thicker myometrial layer at the site of the CS scar, also called residual myometrium thickness (RMT). It possibly decreases the development of a niche, which is an interruption of the myometrium at the site of the uterine scar. Thin RMT and a niche are associated with gynaecological symptoms, obstetric complications in a subsequent pregnancy and delivery and possibly with subfertility.

METHODS

Women undergoing a first CS regardless of the gestational age will be asked to participate in this multicentre, double blinded randomised controlled trial (RCT). They will be randomised to single-layer closure or double-layer closure of the uterine incision. Single-layer closure (control group) is performed with a continuous running, unlocked suture, with or without endometrial saving technique. Double-layer closure (intervention group) is performed with the first layer in a continuous unlocked suture including the endometrial layer and the second layer is also continuous unlocked and imbricates the first. The primary outcome is the reported number of days with postmenstrual spotting during one menstrual cycle nine months after CS. Secondary outcomes include surgical data, ultrasound evaluation at three months, menstrual pattern, dysmenorrhea, quality of life, and sexual function at nine months. Structured transvaginal ultrasound (TVUS) evaluation is performed to assess the uterine scar and if necessary saline infusion sonohysterography (SIS) or gel instillation sonohysterography (GIS) will be added to the examination. Women and ultrasound examiners will be blinded for allocation. Reproductive outcomes at three years follow-up including fertility, mode of delivery and complications in subsequent deliveries will be studied as well. Analyses will be performed by intention to treat. 2290 women have to be randomised to show a reduction of 15% in the mean number of spotting days. Additionally, a cost-effectiveness analysis will be performed from a societal perspective.

DISCUSSION

This RCT will provide insight in the outcomes of single- compared to double-layer closure technique after CS, including postmenstrual spotting and subfertility in relation to niche development measured by ultrasound.

TRIAL REGISTRATION

Dutch Trial Register ( NTR5480 ). Registered 29 October 2015.

Rapid tilt-series acquisition for electron cryotomography

Using a new Titan Krios stage equipped with a single-axis holder, we developed two methods to accelerate the collection of tilt-series. We demonstrate a continuous-tilting method that can record a tilt-series in seconds, but with loss of details finer than ∼4 nm. We also demonstrate a fast-incremental method that can record a tilt-series several-fold faster than current methods and with similar resolution. We characterize the utility of both methods in real biological electron cryotomography workflows. We identify opportunities for further improvements in hardware and software and speculate on the impact such advances could have on structural biology.

Evaluation of pentraxin-3 in familial Mediterranean fever patients during attack and attack-free periods

INTRODUCTION

Pentraxin-3 (PTX-3) is a prototype of pentraxin proteins that have been shown to be involved in acute phase response. In this study, we aimed to investigate the relationship between PTX-3 levels and familial Mediterranean fever (FMF) disease, and to evaluate PTX-3 as a novel diagnostic marker of FMF.

METHOD

Forty-three male patients diagnosed with FMF and 42 healthy individuals were included in the study. Patients with other inflammatory diseases and patients who used drugs having anti-inflammatory properties were excluded from the research. Blood samples were obtained during both attack and attack-free periods.

RESULTS

Patient attack periods were confirmed by combining physical examination and elevation of acute phase reactants. Acute phase reactants were significantly higher in attack versus attack-free periods (p < 0.01), however PTX-3 levels were not significantly different between the two periods. Additionally, PTX-3 levels in FMF patients were higher than in controls in both attack (917.29 ± 725.29 vs 451.83 ± 291.95, p < 0.01) and attack-free periods (748.23 ± 487.53 vs 451.83 ± 291.95, p < 0.01).

CONCLUSION

In this study, we showed that PTX-3 levels, in both FMF attack and attack-free periods, were significantly higher than in the control group. Finally, PTX-3 may be a promising biomarker for FMF diagnosis and may predict FMF attacks (Tab. 2, Fig. 2, Ref. 18).

The presence and absence of periplasmic rings in bacterial flagellar motors correlates with stator type

The bacterial flagellar motor, a cell-envelope-embedded macromolecular machine that functions as a cellular propeller, exhibits significant structural variability between species. Different torque-generating stator modules allow motors to operate in different pH, salt or viscosity levels. How such diversity evolved is unknown. Here, we use electron cryo-tomography to determine the in situ macromolecular structures of three Gammaproteobacteria motors: Legionella pneumophila, Pseudomonas aeruginosa, and Shewanella oneidensis, providing the first views of intact motors with dual stator systems. Complementing our imaging with bioinformatics analysis, we find a correlation between the motor’s stator system and its structural elaboration. Motors with a single H⁺-driven stator have only the core periplasmic P- and L-rings; those with dual H⁺-driven stators have an elaborated P-ring; and motors with Na⁺ or Na⁺/H⁺-driven stators have both their P- and L-rings embellished. Our results suggest an evolution of structural elaboration that may have enabled pathogenic bacteria to colonize higher-viscosity environments in animal hosts.

Bacteria are so small that for them, making their way through water is like swimming in roofing tar for us. In response, these organisms have evolved a molecular machine that helps them move in their environment. Named the bacterial flagellum, this complex assemblage of molecules is formed of three main parts: a motor that spans the inner and outer membranes of the cell, and then a ‘hook’ that connects to a long filament which extends outside the bacterium. More precisely, the motor is formed of the stator, an ion pump that stays still, and of a rotor that can spin. Different rings can also be present in the space between the inner and outer membranes (the periplasm) and surround these components. The stator uses ions to generate the energy that makes the rotor whirl. In turn, this movement sets the filament in motion, propelling the bacterium. Depending on where the bacteria live, the stator can use different types of ions. In addition, while many species have a single stator system per motor, some may have several stator systems for one motor: this may help the microorganisms move in different conditions.

As microbes colonize environments with a different pH or viscosity, they constantly evolve new versions of the motor which are more suitable to their new surroundings. However, a part of the motor remains the same across species. Overall, it is still unclear how bacterial flagella evolve, but examining the structure of new motors can shed light upon this process. Here, Kaplan et al. combine a bioinformatics approach with an imaging technique known as electron cryo-tomography to dissect the structure of the flagellar motor of three species of bacteria with different stator systems, and compare these to known motors of the same class.

The results reveal a correlation between the nature of the stator system and the presence of certain elements. Stators that use sodium ions, or both sodium and hydrogen ions, are associated with two periplasmic rings surrounding the conserved motor structure. These rings do not exist in motors with single hydrogen-driven stators. Motors with dual hydrogen-driven stators are, to some extent, an ‘intermediate state’, with only one of those rings present. As all the studied species currently exist, it is difficult to know which version of the motor is the most ancient, and which one has evolved more recently.

Capturing the diversity of bacterial motors gives us insight into the evolutionary forces that shape complex molecular structures, which is essential to understand how life evolved on Earth. More practically, this knowledge may also help us design better nanomachines to power microscopic robots.

The novel diagnostic marker in low-LVEF heart failure patients

OBJECTIVE

The structural and compositional changes in the myocardium seem to have a major role in the development of heart failure (HF).Imbalance between production and degradation in extracellular collagen results in increase of collagen synthesis biomarkers in the circulation as the carboxy-terminal propeptide of type I procollagen (PIP). Here we aimed to determine role of PIP in the diagnosis of chronic HF.

MATERIAL AND METHODS

87 patients with HF group and 80 healthy subjects were enrolled into the study. Echocardiographic examination was performed.At the beginning of the study, serum B type natriuretic peptide (BNP), PIP, high sensitive C-reactive protein (hs-CRP) were measured . The subjects were followed for one year then after.

RESULTS

Average PIP value of HF group was significantly higher than that of the control group (p < 0.001). Both hs-CRP and BNP values were well correlated to PIP values (p < 0.001). In the HF group, PIP value of patients who died at the end of one year was similar to that of patients who survived at the end of first year.

CONCLUSION

PIP may not mirror acute events in follow-up of chronic heart failure but it is a very beneficial biomarker in diagnosis of low-LVEF heart failure with high sensitivity and specificity (Tab. 2, Fig. 1, Ref. 16).

Prognostic Utility of Hypokalemia in Cirrhotic Patients

BACKGROUND AND AIM

We researched the relationships between serum potassium level and prognostic scores and complications of cirrhosis, and mortality.

METHODS

This study was performed retrospectively in Turkish High Specialty Training and Research Hospital between 2009 and 2015. Patients who had missing patient files and electrolyte disorder for another reason, showed complications at the time of application and were using diuretics were excluded from the study.

RESULTS

218 patients were included in the study. During the follow-up period, 23.4% (n: 51) of the entire population passed away. Compared to the patients who survived, the patients who passed away had higher HCC and HES development rate, mean Child-Pugh and MELD score and lower mean blood potassium level. The stepwise multivariable Cox regression model which included significant independent predictors showed that ChildPugh score (HR: 1.29; p <0.001), MELD score (HR:1.13; p= 0.006), and potassium level (HR: 0.18; p< 0.001) were independent predictors of mortality. The cut off value for potassium level in predicting mortality was found to be ≤ 3.4 mmol/L with 80.4% sensitivity and 100% specificity. Compared to the patients with a potassium level > 3.4 mmol/L, the patients with a potassium level ≤ 3.4 mmol/L had higher mortality rate, HCC and HES development rate, mean Child-Pugh and mean MELD scores.

CONCLUSION

Hypokalemia is an important prognostic factor in cirrhotic patients.

Laparoscopy in the management of lumboperitoneal shunt catheter in obese patients with pseudotumor cerebri

Lumboperitoneal shunts are widely used for the treatment of patients diagnosed with pseudotumor cerebri (PTC). Obesity is a risk factor for PTC. In particular, catheter migration out of the abdominal cavity is more commonly observed in morbidly obese patients. The aim of this study was to discuss the underlying mechanisms of catheter migration and treatment modalities in morbidly obese patients with PTC. The present study included four morbidly obese patients. All cases had undergone the previous laparotomy for insertion of a distal catheter into the abdominal cavity. In three cases, migration of the distal catheter out of the abdominal cavity was observed. Migration of the proximal tip of the catheter out of the spinal canal was observed in the fourth case. In all cases, laparoscopic revision surgeries were performed. During revision surgery, a catheter tunnel was prepared immediately over the external oblique fascia to obtain the shortest and deepest tunnel, and a distal catheter was inserted by laparoscopic guidance posterolaterally, i.e., through the postaxillary line. None of the patients developed any complications during the follow-up period of 4 years. We recommend laparoscopic insertion of distal catheters through the postaxillary line into the abdominal cavity using as short a catheter route as possible. Thus, tension and traction on the catheter due to abdominal movements can be decreased in morbidly obese patients to prevent catheter migration.

Israel transcutaneous bilirubin nomogram predicts significant hyperbilirubinemia

OBJECTIVE

We constructed a transcutaneous bilirubin (TcB) nomogram to represent major sectors of the Israeli population. We studied the risk of hyperbilirubinemia, defined as meeting the requirements for phototherapy, per percentile risk category.

STUDY DESIGN

Newborns ⩾36 weeks gestation were tested daily for TcB, using Drager JM-103 devices, during birth hospitalization. A nomogram was constructed and divided into four risk groups and validated by calculating the need for phototherapy for each group.

RESULTS

A total of 3303 measurements were performed on 1059 consecutive newborns including Ashkenazi, Sephardic and mixed Ashkenazi/Sephardic Jews, Arab and Ethiopian Jewish. Phototherapy risk increased progressively and more than 100-fold, from 0/225 in the <40th percentile group through 27/120 (22.5%) for those >95th percentile (relative risk (95% confidence interval) 102 (6 to 1669) for those >95th percentile compared with those <40th percentile). The optimal risk for discriminating the need for phototherapy was >75th percentile (sensitivity 93.33, specificity 59.47).

CONCLUSION

The risk of significant hyperbilirubinemia increased progressively with increasing percentile. Newborns >75th percentile groups are at high risk for phototherapy and should be closely monitored.

Tp-e interval and Tp-e/QT ratio in patients with celiac disease

OBJECTIVES

Celiac disease is a chronic immune-mediated disease of the small intestine. It has been known that dilated cardiomyopathy and ischemic coronary artery disease have become more frequent in patients with celiac disease. The aim of the study was to assess Tp-e interval and Tp-e/QT ratio in patients with celiac disease.

MATERIAL AND METHODS

This study was conducted at a single center in collaboration with gastroenterology and cardiology clinics. Between January 2014 and June 2015, a total of 76 consecutive patients were enrolled (38 patients with celiac disease and 38 control subjects). Tp-e interval, Tp-e/QT and Tp-e/QTc ratio were measured from the 12-lead electrocardiogram.

RESULTS

Tp-e interval (64.2±11.0 vs. 44.5±6.0; p<0.001), Tp-e/QT ratio (0.18±0.02 vs. 0.13±0.02; p<0.001) and Tp-e/QTc ratio (0.16±0.02 vs. 0.11±0.01; p<0.001) were significantly higher in patients with celiac disease than control subjects. There was a significant positive correlation between Tp-e/QTc ratio and disease duration in patients with celiac disease (r=0.480, p=0.003) and also there was a significant positive correlation between Tp-e/QTc ratio and erythrocyte sedimentation rate (r=0.434, p<0.001).

CONCLUSIONS

Our study showed that Tp-e interval, Tp-e/QT and Tp-e/QTc ratios were increased in patients with celiac disease. Whether these changes increase the risk of ventricular arrhythmia deserve further studies.

Factors associated with increased irisin levels in the type 1 diabetes mellitus

OBJECTIVE

The aim of the present study was to determine the irisin levels in patients with the type 1 diabetes mellitus (T1DM) and to examine the relation of irisin levels with the inflammation and autoimmunity.

METHODS

This study included 35 cases diagnosed with T1DM and 36 healthy volunteers. Antiglutamic acid decarboxylase (anti-GAD), islet cell antibody (ICA), and insulin autoantibody levels were measured in patients at the time when they were included into the study and recorded from the patient files. Serum irisin levels were measured by ELISA kit.

RESULTS

The median irisin levels were determined higher in T1DM group compared to the control one (6.8 ng/ml vs. 4.8 ng/ml, p=0.022; respectively). Median irisin levels were higher in anti-GAD (p=0.022) and ICA (p=0.044) positive groups compared to negative groups. In T1DM group, irisin levels displayed positive correlation with glycosylated hemoglobin (HbA1c) (r=0.377, p<0.001) and anti-GAD (r=0.392, p=0.020) and negative correlation with creatinine (r=-0390, p=0.021). In multivariate regression model, HbA1c (B±SE: 2.76±17683, p<0.001), and anti-GAD (B±SE: 2.311±0.610, p=0.001) were determined as independent predictors for predicting the irisin levels.

CONCLUSION

In patients with T1DM, which chronic inflammation and autoimmunity take part in their etiopathogenesis, anti-GAD levels were an independent risk factor for the irisin. Th is may suggest that factors such as inflammation and autoimmunity can be effective in the synthesis of irisin.

Influence of different irrigation and nitrogen levels on crude oil and fatty acid composition of maize (

The effect of irrigation and nitrogen fertilizer levels on the crude oil and fatty acid composition of maize cultivars was studied. Three levels of irrigation (50, 75 and 100% of field capacity) and nitrogen (100, 200 and 300 kg·ha-1) were used for treatment groups. After harvest, the crude oils were extracted and fatty acid profiles were determined by Gas Chromatography system. The study was repeated for two years and the interaction effects of fertilizer and irrigation were determined. Our results show that the crude oil content was affected positively by the fertilizer and the irrigation applications. As expected, the most abundant fatty acid was linoleic and the harvest year did not alter it. The highest linoleic acid content value was obtained with a 50% field capacity and 300 kg·ha-1 fertilizer treatment combination. In addition, fatty acid contents varied with the changing of interaction effects except for myristic and palmitic acid. Oleic acid was the second abundant fatty acid in the oil samples and the lowest oleic acid value was obtained with a 50% field capacity and 300 kg·ha-1 fertilizer treatment combination. Oleic acid content tended to increase with 75% field capacity but 100% field capacity treatment decreased in it.

Photon-Induced Near-Field Electron Microscopy of Eukaryotic Cells

Photon-induced near-field electron microscopy (PINEM) is a technique to produce and then image evanescent electromagnetic fields on the surfaces of nanostructures. Most previous applications of PINEM have imaged surface plasmon-polariton waves on conducting nanomaterials. Here, the application of PINEM on whole human cancer cells and membrane vesicles isolated from them is reported. We show that photons induce time-, orientation-, and polarization-dependent evanescent fields on the surfaces of A431 cancer cells and isolated membrane vesicles. Furthermore, the addition of a ligand to the major surface receptor on these cells and vesicles (epidermal growth factor receptor, EGFR) reduces the intensity of these fields in both preparations. We propose that in the absence of plasmon waves in biological samples, these evanescent fields reflect the changes in EGFR kinase domain polarization upon ligand binding.

Heme oxygenase-1 promoter polymorphisms: do they modulate neonatal hyperbilirubinemia?

The role of genetic factors in the modulation of serum bilirubin levels and the pathophysiology of neonatal hyperbilirubinemia is being increasingly recognized. Heme oxygenase-1 (HO-1) is the rate-limiting enzyme by which heme is catabolized to biliverdin and thence to bilirubin, with the simultaneous release of equimolar quantities of ferrous iron (Fe³⁺) and carbon monoxide. Polymorphisms of the HO-1 gene promoter may modulate transcriptional activity, thereby augmenting or attenuating HO-1 expression with resultant modulation of the production of bilirubin. Few studies have related these polymorphisms to neonatal bilirubin metabolism and have reported conflicting results. In this clinical review, we surveyed the role of HO-1 gene promoter polymorphisms in the control of bilirubin production and further considered their role, if any, in the pathophysiology of neonatal hyperbilirubinemia.