Chemical Genetics in C. elegans Identifies Anticancer Mycotoxins Chaetocin and Chetomin as Potent Inducers of a Nuclear Metal Homeostasis Response.

C. elegans numr-1/2 (nuclear-localized metal-responsive) is an identical gene pair encoding a nuclear protein previously shown to be activated by cadmium and disruption of the integrator RNA metabolism complex. We took a chemical genetic approach to further characterize regulation of this novel metal response by screening 41,716 compounds and extracts for numr-1p::GFP activation. The most potent activator was chaetocin, a fungal 3,6-epidithiodiketopiperazine (ETP) with promising anticancer activity. Chaetocin activates numr-1/2 strongly in the alimentary canal but is distinct from metal exposure, because it represses canonical cadmium-responsive metallothionine genes. Chaetocin has diverse targets in cancer cells including thioredoxin reductase, histone lysine methyltransferase, and acetyltransferase p300/CBP; further work is needed to identify the mechanism in C. elegans as genetic disruption and RNAi screening of homologues did not induce numr-1/2 in the alimentary canal and chaetocin did not affect markers of integrator dysfunction. We demonstrate that disulfides in chaetocin and chetomin, a dimeric ETP analog, are required to induce numr-1/2. ETP monomer gliotoxin, despite possessing a disulfide linkage, had almost no effect on numr-1/2, suggesting a dimer requirement. Chetomin inhibits C. elegans growth at low micromolar levels, and loss of numr-1/2 increases sensitivity; C. elegans and Chaetomiaceae fungi inhabit similar environments raising the possibility that numr-1/2 functions as a defense mechanism. There is no direct orthologue of numr-1/2 in humans, but RNaseq suggests that chaetocin affects expression of cellular processes linked to stress response and metal homeostasis in colorectal cancer cells. Our results reveal interactions between metal response gene regulation and ETPs and identify a potential mechanism of resistance to this versatile class of preclinical compounds.

Reducing crash risk for young drivers: Protocol for a pragmatic randomised controlled trial to improve young driver sleep.

Background: Road trauma is a leading cause of death and disability for young Australians (15-24 years). Young adults are overrepresented in crashes due to sleepiness, with two-thirds of their fatal crashes attributed to sleepy driving. This trial aims to examine the effectiveness of a sleep extension and education program for improved road safety in young adults. Methods: Young adults aged 18-24 years (n = 210) will be recruited for a pragmatic randomised controlled trial employing a placebo-controlled, parallel-groups design. The intervention group will undergo sleep extension and receive education on sleep, whereas the placebo control group will be provided with information about diet and nutrition. The primary outcomes of habitual sleep and on-road driving performance will be assessed via actigraphy and in-vehicle accelerometery. A range of secondary outcomes including driving behaviours (driving simulator), sleep (diaries and questionnaire) and socio-emotional measures will be assessed. Discussion: Sleep is a modifiable factor that may reduce the risk of sleepiness-related crashes. Modifying sleep behaviour could potentially help to reduce the risk of young driver sleepiness-related crashes. This randomised control trial will objectively assess the efficacy of implementing sleep behaviour manipulation and education on reducing crash risk in young adult drivers.

Epigenetic small-molecule screen for inhibition and reversal of acinar ductal metaplasia in mouse pancreatic organoids.

Background: Acinar ductal metaplasia (ADM) is among the earliest initiating events in pancreatic ductal adenocarcinoma (PDAC) development. Methods: We developed a novel morphology-based screen using organoids from wildtype and p48Cre/+ (Cre) mice to discover epigenetic modulators that inhibit or reverse pancreatic ADM more effectively than the broad-spectrum HDAC inhibitor trichostatin A (TSA). Results: Of the 144 compounds screened, nine hits and two additional natural product HDAC inhibitors were validated by dose-response analysis. The class I HDAC inhibitors apicidin and FK228, and the histone methyltransferase inhibitor chaetocin demonstrated pronounced ADM inhibition and reversal without inducing significant cytotoxicity at 1 µM. Thioester prodrug class I HDAC inhibitor largazole attenuated ADM while its disulfide homodimer was effective in both ADM inhibition and reversal. Prioritized compounds were validated for ADM reversal in p48Cre/+; LSL-KrasG12D/+ (KC) mouse organoids using both morphological and molecular endpoints. Molecular index analysis of ADM reversal in KC mouse organoids demonstrated improved activity compared to TSA. Improved prodrug stability translated into a stronger phenotypic and molecular response. RNA-sequencing indicated that angiotensinogen was the top inhibited pathway during ADM reversal. Conclusion: Our findings demonstrate a unique epigenetic mechanism and suggest that the phenotypic screen developed here may be applied to discover potential treatments for PDAC.

Perceived Neighborhood Characteristics and Sleep in Australian Adults.

BACKGROUND: Poor sleep can contribute to poorer health and socioemotional outcomes. Sleep health can be influenced by a range of individual and other socioecological factors. Perceptions of neighborhood physical and social characteristics reflect broader social-level factors that may influence sleep, which have not been well studied in the Australian context. This study examined the association between perceived neighborhood characteristics and sleep in a large sample of Australians. METHODS: Data were from 9,792 people aged 16 years or older, from Waves 16 and 17 of the nationally representative Household, Income and Labour Dynamics in Australia Survey. Associations between perceived neighborhood characteristics (neighborly interaction and support, environmental noise, physical condition, and insecurity) and self-reported sleep duration, sleep disturbance, and napping were examined using multiple logistic regression models. RESULTS: "Neighborhood interaction and support" and "neighborhood physical condition" were not significantly associated with any sleep outcomes after adjusting for relevant covariates. However, "environmental noise" and "neighborhood insecurity" remained significantly associated with sleep duration and sleep disturbance. None of the neighborhood characteristics were associated with napping. Furthermore, associations did not significantly vary by gender. CONCLUSIONS: This study highlights the potential benefit of public health policies to address noise and safety in neighborhoods to improve sleep.

Epigenetic Small-Molecule Screen for Inhibition and Reversal of Acinar Ductal Metaplasia in Mouse Pancreatic Organoids.

Background: Acinar ductal metaplasia (ADM) is among the earliest initiating events in pancreatic ductal adenocarcinoma (PDAC) development. Methods: We developed a novel morphology-based screen using organoids from wildtype and p48 Cre/+ (Cre) mice to discover epigenetic modulators that inhibit or reverse pancreatic ADM more effectively than the broad-spectrum HDAC inhibitor trichostatin A (TSA). Results: Of the 144 compounds screened, nine hits and two additional natural product HDAC inhibitors were validated by dose-response analysis. The class I HDAC inhibitors apicidin and FK228, and the histone methyltransferase inhibitor chaetocin demonstrated pronounced ADM inhibition and reversal without inducing significant cytotoxicity at 1 µM. Thioester prodrug class I HDAC inhibitor largazole attenuated ADM while its disulfide homodimer was effective in both ADM inhibition and reversal. Prioritized compounds were validated for ADM reversal in p48 Cre/+ ;LSL-Kras G12D/+ (KC) mouse organoids using both morphological and molecular endpoints. Molecular index analysis of ADM reversal in KC mouse organoids demonstrated improved activity compared to TSA. Improved prodrug stability translated into a stronger phenotypic and molecular response. RNA-sequencing indicated that angiotensinogen was the top inhibited pathway during ADM reversal. Conclusion: Our findings demonstrate a unique epigenetic mechanism and suggest that the phenotypic screen developed here may be applied to discover potential treatments for PDAC.

Sleep mediates the relationship between precarious employment and mental health.

Background: Current evidence suggests that precarious employment is a risk factor for poor mental health. Although the mechanisms underpinning this relationship are unclear, poor sleep has been proposed to have a role in this relationship. This study explored the mediating effects of poor sleep quality and duration on the relationship between precarious employment and mental health. Methods: Data were obtained from wave 17 of the Household, Income and Labour Dynamics in Australia survey. A novel precarious employment score (PES) was developed using exploratory and confirmatory factor analyses (CFA) in 8127 workers (4195 female, aged 18-65). Structural equation modelling (SEM) was used to evaluate the mediating effect of sleep quality and duration on the relationship between precarious employment and mental health (SF-36 mental health subscale). Results: The PES identified 650 workers with a high level of precariousness, 2417 with a moderate level of precariousness, and 5060 workers with a low level of precariousness out of 8127 in total. There was a significant direct association between precarious employment and mental health; with higher precarity increasing the likelihood of poor mental health. The SEM results revealed that sleep quality partially mediated the association between precarious employment and mental health (Coefficient = 0.025, 95 % CI [0.015, 0.034], P ≤ 0.001). However, a mediation effect was not found for sleep duration. Conclusion: Encouraging precarious employees to improve sleep quality may mitigate the adverse effects of precarious work on their mental health. Further objective measurement of sleep duration warrants a more accurate insight into this mediating effect in this group.

Precarious employment and associated health and social consequences; a systematic review.

OBJECTIVE: This systematic review aims to identify, evaluate, and summarise the consequences of precarious employment. METHODS: We included studies published within the last ten years (Jan 2011-July 2021) that employed at least two of three key dimensions of precarious employment: employment insecurity, income inadequacy, and lack of rights and protection. RESULTS: Of the 4,947 initially identified studies, only five studies met our eligibility criteria. These five studies were of moderate quality as assessed by the Newcastle-Ottawa Scale. Our review found that the current literature predominantly defines precarity based on the single criterion of employment insecurity. Our review identified evidence for the negative consequences of precarious employment, including poorer workplace wellbeing, general health, mental health, and emotional wellbeing. The findings indicated an increase in the magnitude of these adverse outcomes with a higher degree of job precariousness. CONCLUSIONS: The rise of employment precariousness will likely continue to be a major issue in the coming years. More research is needed to inform effective policies and practices using a consensus definition of precarious employment. IMPLICATIONS FOR PUBLIC HEALTH: The presence of adverse effects of precarious employment suggests workplace initiatives are essential to mitigate the negative consequences of precarity.

Interventions to increase sleep duration in young people: A systematic review.

This systematic review explored the outcomes of current interventions to increase sleep duration in healthy young people (14-25 years). Nine databases were systematically searched, and 26 studies were included in this review. Quality assessment of the included studies was evaluated using two tools: the Newcastle-Ottawa scale, and Cochrane Risk of Bias. The interventions incorporated a range of strategies including behavioral (46.2%), educational (26.9%), a combination of behavioral and educational (15.4%), and other strategies such as physical therapy (11.5%). The findings indicate that behavioral and combination interventions were consistently effective in increasing sleep duration in healthy young people. Educational interventions alone were less effective at increasing young people's sleep duration. Of all the included studies, only one randomized control trial but none of the non-randomized trials were rated as good quality. Our findings suggest a combination of strategies with an emphasis on personalization of intervention could possibly maximize the chances of success at improving sleep duration in healthy young people. More high-quality studies with long-term assessments (≥ 6 months) should be conducted to test the efficacy and durability of interventions to increase sleep duration in young people, as well as the clinical implications to mental and physical health.

Targeted and functional genomics approaches to the mechanism of action of lagunamide D, a mitochondrial cytotoxin from marine cyanobacteria.

Lagunamide D, a cyanobacterial cyclodepsipeptide, exhibits potent antiproliferative activity against HCT116 colorectal cancer cells (IC50 5.1 nM), which were used to probe the mechanism of action. Measurements of metabolic activity, mitochondrial membrane potential, caspase 3/7 activity and cell viability indicate the rapid action of lagunamide D on mitochondrial function and downstream cytotoxic effects in HCT116 cells. Lagunamide D preferentially targets the G1 cell cycle population and arrests cells in G2/M phase at high concentration (32 nM). Transcriptomics and subsequent Ingenuity Pathway Analysis identified networks related to mitochondrial functions. Lagunamide D induced mitochondrial network redistribution at 10 nM, suggesting a mechanism shared with the structurally related aurilide family, previously reported to target mitochondrial prohibitin 1 (PHB1). Knockdown and chemical inhibition of ATP1A1 sensitized the cells to lagunamide D, as also known for aurilide B. We interrogated potential mechanisms behind this synergistic effect between lagunamide D and ATP1A1 knockdown by using pharmacological inhibitors and extended the functional analysis to a global level by performing a chemogenomic screen with a siRNA library targeting the human druggable genome, revealing targets that modulate susceptibility to lagunamide D. In addition to mitochondrial targets, the screen revealed hits involved in the ubiquitin/proteasome pathway, suggesting lagunamide D might exert its effects by additionally affecting proteostasis. Our analysis illuminated cellular processes of lagunamide D that can be modulated in parallel to mitochondrial functions. The identification of potential synergistic drug combinations that can alleviate undesirable toxicity may open possibilities to resurrect this class of compounds for anticancer therapy.

[Posterior Tibial Slope as a Morphological Risk Factor for Anterior Cruciate Ligament Reconstruction: a Retrospective Cohort Study]. / Zadní sklon tibie jako rizikový morfologický faktor kolena u náhrady PZV: hodnocení souboru pacientu.

PURPOSE OF THE STUDY Increased tibial slope facilitates anterior translation of tibia relative to the femur, thereby increasing the load on both the native and replaced anterior cruciate ligament. This study aims to retrospectively review the posterior tibial slope in a cohort of our patients after the ACL reconstruction and revision ACL reconstruction. Based on the results obtained by measurements, we aimed to confirm or disprove the claim that the increased posterior tibial slope is one of the risk factors of the ACL reconstruction failure. Another aim of the study was to assess whether there are any correlations between the posterior tibial slope and basic somatic parameters (height, weight, BMI) or the patient s age. MATERIAL AND METHODS The posterior tibial slope was measured retrospectively on lateral X-rays of 375 patients. There were 83 revision reconstructions and 292 primary reconstructions performed. The patient s age at the time of injury, height and weight were recorded and the BMI was calculated. The findings were then statistically analysed. RESULTS The mean posterior tibial slope in 292 primary reconstructions was 8.6 degrees, whereas the mean posterior tibial slope in 83 revision reconstructions was 12.3 degrees. The difference between the studied groups was statistically (p<0.0001) and substantively significant (d=1.35). In the breakdown into men and women, the mean tibial slope was 8.6 degrees in the group of men with primary reconstruction and 12.4 degrees in the group of men with revision reconstruction (p < 0.0001, d = 1.38). A similar result was achieved in women where in the group with primary reconstruction the mean tibial slope was 8.4 degrees, while in the group with revision reconstruction it was 12.3 degrees (p < 0.0001, d = 1.41). Furthermore, a higher age in men at the time of revision surgery (p = 0.009; d = 0.46) and a lower BMI in women at the time of revision surgery (p = 0.0342; d = 0.12) were observed. Conversely, neither height nor weight were different, both when comparing the whole groups and the groups in a breakdown by sex. DISCUSSION As regards the main aim, our results are in line with the results reported by majority of other authors, and they are substantively significant. The posterior tibial slope is a significant risk factor in anterior cruciate ligament replacements, with tibial slope above 12 degrees increasing the risk of ligament failure, namely both in men and women. On the other hand, this is obviously not the sole cause of the ACL reconstruction failure since there are also other risk parameters. It is not yet clear whether it makes sense to indicate correction osteotomy before the ACL replacement in all patients with an increased posterior tibial slope. CONCLUSIONS Our study confirmed a greater posterior tibial slope in the revision reconstruction group compared to the primary reconstruction group. Thus, we confirmed that greater posterior tibial slope may be a factor leading to the ACL reconstruction failure. Since the posterior tibial slope is easily measured on the baseline X-rays, we recommend to perform this measurement routinely before each ACL reconstruction. In the case of a high posterior tibial slope, slope correction should be considered to prevent potential ACL reconstruction failure. Key words: anterior cruciate ligament reconstruction, ACL graft failure, morphological risk factors, posterior tibial slope.

[Arthroscopic Superior Capsule Reconstruction with a Long Head of the Biceps Tendon Autograft: One-Year Follow-up Results]. / Rocní klinické výsledky artroskopické rekonstrukce horní kapsuly ramenního kloubu pomocí slachy dlouhé hlavy bicepsu.

PURPOSE OF THE STUDY: Superior Capsule Reconstruction (SCR) of the shoulder joint has recently been included in the portfolio of interventions as a solution to irreparable rotator cuff tears. One of the options is to use a long head of the biceps tendon (LHBT) autograft. This paper presents the fi rst clinical outcomes of the SCR of the shoulder joint using the LHBT autograft. MATERIAL AND METHODS It is a prospective non-randomised study in which 14 patients were included, namely 7 men and 7 women. The patients were evaluated using the pain VAS, UCLA (The University of California at Los Angeles) Shoulder Rating Scale and ASES (The American Shoulder and Elbow Surgeons) Shoulder Score. The minimum follow-up was 12 months after surgery. The measured values were analysed using the standard statistical methods. RESULTS From August 2020 to January 2022, a total of 14 SCR with biceps tendon autograph were performed at our department. The mean age of the patients was 62 years (40-72). The mean value of the UCLA Shoulder Score was 12.36 ± 2.92 points preoperatively, while after surgery the obtained values increased to the mean value of 28.86 ± 3.08 points. The ASES score was 25.48 ± 3.89 points preoperatively and 82.41 ± 7.95 points at one year after surgery. The preoperative mean VAS score was 6.14 ± 1.10 points and 1.36 ± 0.93 points at one year after surgery. The mean active shoulder fl exion measured preoperatively was 140 degrees, whereas at one year after surgery it was 171 degrees. The mean active abduction reached 123 degrees before surgery and 169 degrees after surgery. The mean active external rotation of the shoulder joint was 59 degrees preoperatively and 52 degrees postoperatively. The mean active external rotation at 90 degrees of abduction was 52 degrees preoperatively and 60 degrees postoperatively. Whereas the improvement as against the preoperative status measured by the UCLA, ASES and pain VAS was signifi cant, the differences in the range of motion were signifi cant in the case of active fl exion and abduction only. DISCUSSION Painful irreparable rotator cuff tear constitutes an indication for SCR. The reconstruction is performed using autografts, allografts and xenografts. In literature, several SCR surgical techniques using a long head of the biceps tendon have been presented. In most of these techniques the supraglenoid insertion of the LHBT was left intact. Our study showed a signifi - cant relief from problems and good functional outcomes at 1 year after surgery when the biceps tendon had been used. Similar results are reported also by other studies using the biceps tendon for SCR. When comparing this study and the other study we published earlier on SCR with xenografts, there is no signifi cant difference in the clinical outcomes between these two techniques. On the very contrary, they are slightly better in some parameters. CONCLUSIONS Arthroscopic SCR of the shoulder joint with the biceps tendon reports good clinical outcomes at one year after surgery both with regard to the relief from problems and range of motion. Due to low morbidity of graft harvesting, low cost, and easy surgical technique, it appears to be the fi rst-choice method for superior capsule reconstruction of an irreparable tear of supraspinatus or infraspinatus if the long head of the biceps tendon is preserved. A longer follow-up period and evaluation of a larger study population would be necessary to defi nitely confi rm the success rate of the described procedure. KEY WORDS: massive rotator cuff tears, irreparable rotator cuff tears, superior capsular reconstruction, autograft, long head of the biceps tendon.

Anxiolytic Effect of Peptides from Sea Anemone Heteractis crispa, Modulators of TRPV1 and ASIC Channels.

A number of studies confirmed the involvement of transient receptor potential vanilloid (TRPV) and acid-sensing (ASIC) ion channels in the physiological processes associated with the development of anxiety disorders. This makes their ligands new potential anxiolytic agents. We examined the efficacy of two peptides from the sea anemone Heteractis crispa, Hcr 1b-2 and HCRG21, affecting ASIC1a and TRPV1 channels, respectively, in the open field and elevated plus maze tests. According to the obtained data, HCRG21 significantly decreases both the level of anxiety and stimulates the activity of animals at doses of 0.01-1 mg/kg, whereas Hcr 1b-2 has a weak anxiolytic effect only at a dose of 0.1 mg/kg. The pharmacodynamic study showed that the HCRG21 has an anxiolytic effect for 2 h, and its effectiveness is higher than that of the reference drug.

An epigenetic small molecule screen to target abnormal nuclear morphology in human cells.

Irregular nuclear shapes are a hallmark of human cancers. Recent studies suggest that alterations to chromatin regulators may cause irregular nuclear morphologies. Here we screened an epigenetic small molecule library consisting of 145 compounds against chromatin regulators for their ability to revert abnormal nuclear shapes that were induced by gene knockdown in noncancerous MCF10A human mammary breast epithelial cells. We leveraged a previously validated quantitative Fourier approach to quantify the elliptical Fourier coefficient (EFC ratio) as a measure of nuclear irregularities, which allowed us to perform rigorous statistical analyses of screening data. Top hit compounds fell into three major mode of action categories, targeting three separate epigenetic modulation routes: 1) histone deacetylase inhibitors, 2) bromodomain and extraterminal domain protein inhibitors, and 3) methyl-transferase inhibitors. Some of the top hit compounds were also efficacious in reverting nuclear irregularities in MDA-MB-231 triple negative breast cancer cells and in PANC-1 pancreatic cancer cells in a cell-type-dependent manner. Regularization of nuclear shapes was compound-specific, cell-type specific, and dependent on the specific molecular perturbation that induced nuclear irregularities. Our approach of targeting nuclear abnormalities may be potentially useful in screening new types of cancer therapies targeted toward chromatin structure.

Inflammasome Activation in Gingival Epithelial Cells.

Inflammasomes are multiprotein complexes that assemble in host cells upon recognition of infection or danger via pattern recognition receptors and/or danger recognition receptors. The assembly of inflammasomes results in the activation of caspase-1 and is followed by the enzymatic maturation and secretion of inflammatory cytokines like interleukin 1ß (IL-1ß) and IL-18.In the oral cavity, gingival epithelial cells (GECs) line the mucosa and have a barrier role for invading pathogens. In these cells, the NLRP3 inflammasome is the best studied and has been shown to play a role in the inflammatory immune response against a variety of oral pathogens. As such, in order to study gingivitis and other oral pathologic inflammatory conditions, studying the activation of inflammasomes is important. The simplest way to detect inflammasome activation is to detect the activated caspase-1, as well as the secretion of mature IL-1ß and IL-18, via ELISA, Western blot, and immunofluorescence techniques.Here we describe the detection of NLRP3 inflammasome activation by the oral pathogen Porphyromonas gingivalis in human GECs via these three methods and mention other methods and techniques that we have successfully used together with these in our quest to understand the host-pathogen interaction.

[Arthroscopic Bankart Repair with Remplissage for Anterior Instability: Functional Outcomes, Risk of Failure]. / Artroskopická Bankartova operace se soucasnou remplissage: funkcní výsledky, riziko selhání.

PURPOSE OF THE STUDY This study aimed to evaluate the clinical outcomes and the rate of recurrence in patients who had undergone arthroscopic Bankart repair with remplissage for anterior instability of the glenohumeral joint. MATERIAL AND METHODS The study included 96 arthroscopic Bankart procedures with remplissage performed between 2013 and 2019 at our department in 93 patients (81 men and 12 women; with the mean age of 33 years). We gathered and analysed preoperative data, including a 3D-CT scan of the affected shoulder. Apart from stability, the functional results were assessed postoperatively using the WOSI, SSV, Rowe score, and by measuring the strength of shoulder girdle muscles. The non-parametric MannWhitney U-test was used to identify the predisposing factors for recurrence of glenohumeral instability. RESULTS The arthroscopic Bankart repair with remplissage was indicated in 74 shoulders for primary TUBS and in 22 shoulders as a revision procedure. The recurrent instability was observed in 13 of 96 operated shoulders (13.5%). Subjective instability (positive apprehension test in the extreme positions of the shoulder joint, in abduction and external rotation in particular) was reported by 10 patients (10/13; 77%), three patients experienced a redislocation of the glenohumeral joint in the postoperative follow-up (3/13 patients; 23%). The risk of recurrence of the glenohumeral instability was not correlated with either the number of previous stabilisation procedures, or any other preoperative or intraoperative parameters. Conversely, a new postoperative injury was a factor of key importance. The patients with recurrent instability (subjective instability or glenohumeral dislocation) achieved a significantly lower Rowe score, SSV, postoperative VAS, and worse overall satisfaction with the procedure compared to the group with no recurrent instability. The remplissage induced minor limitations of external rotation at 0° abduction and internal rotation at 90° abduction. After rehabilitation, the muscle strength of the operated shoulder in both groups was comparable to that of the untreated shoulder in all planes of the shoulder range of motion. DISCUSSION Our study confirms the clinical relevance of the addition of remplissage to the arthroscopic Bankart procedure for reducing the rate of recurrent glenohumeral instability in TUBS with a clinically significant Hill-Sachs lesion. Satisfaction with the surgical outcome is high; the functional outcomes are very good, including muscle strength. Surprisingly, though, the risk of recurrent instability does not correlate with the number of implants used in the stabilisation procedure. CONCLUSIONS Addition of remplissage to the arthroscopic Bankart stabilisation in patients with a clinically significant Hill-Sachs lesion shows a low risk of recurrence of glenohumeral instability after surgery compared to the conventional arthroscopic Bankart repair alone. The remplissage does cause minor restrictions in the glenohumeral joint external rotation, but it was not reflected in the satisfaction of patients or a lower clinical score of the shoulder joint. The preoperative assessment of the HillSachs lesion using the "glenoid track" on a 3D-CT scan helps improve the preoperative planning and prediction of outcomes of the stabilisation procedure. Key words: glenohumeral instability, Bankart defect, Hill-Sachs lesion, Bankart repair, remplissage, arthroscopy.

[Unstable RAMP Lesions of the Medial Meniscus in ACL-Deficient Knee: Comparing the Outcomes of Outside-in versus All-inside Surgical Repair - a Retrospective Study]. / Nestabilní RAMP léze mediálního menisku u LCA deficientního kolena: srovnání výsledku operacní terapie technikou outside-in versus all-inside ­ retrospektivní studie.

PURPOSE OF THE STUDY We present the results of the retrospective study comparing the clinical outcomes of outside-in versus all-inside suture techniques of unstable RAMP lesions (RL) of the medial meniscus in patients with simultaneous ACL lesion with a minimum two-year follow-up. MATERIAL AND METHODS The retrospective evaluation covered two groups of patients who underwent the arthroscopic repair of unstable RL in combination with anterior cruciate ligament reconstruction (ACLR). Group 1 included 42 patients (28 men/24 women). Group 2 consisted of 36 patients (21 men/15 women). In Group 1, RL suture repair using the outside-in technique by posteromedial approach with absorbable PDS suture was performed, while in Group 2 the all-inside technique of RL suture via the standard anteromedial portal was applied using the Fast-Fix system (Smith Nephew, USA). The evaluation was done preoperatively and postoperatively with the mean follow-up of 27.9 months in Group 1 and 30.1 months in Group 2. The patients were assessed using the subjective IKDC score and the side-to-side difference (SSD) in ventral laxity was measured by Genourob (GNRB) laximeter at the applied pressure of 134 N and 250 N. Moreover, the failure rate of RAMP lesion repair, ACL graft, necessity of secondary partial meniscectomy and return to pre-injury level of sport were analysed. RESULTS The median IKDC score increased in Group 1 from 56 points preoperatively to 92 points postoperatively and in Group 2 from 58 points preoperatively to 90 points postoperatively (p>0.05). The median value of SSD in ventral laxity of the knee measured by the GNRB laximeter at the applied pressure of 134 N in Group 1 was 5.6 mm preoperatively and 1.9 mm postoperatively and in Group 2 it was 5.9 mm preoperatively and 2.3 mm postoperatively. At the pressure of 250 N, the median value in Group 1 was 7.9 mm preoperatively and 2.7 mm postoperatively and in Group 2 it was 8.1 mm preoperatively and 3.2 mm postoperatively. When comparing the SSD of the groups postoperatively, no statistically significant difference was found (p>0.05). Revision arthroscopy was performed in 8 patients. In 1 patient (2.4 %) in Group 1 and in 4 patients (11.1%) in Group 2 a rerupture of the RL of the meniscus occurred and partial meniscectomy was performed. In Group 2, statistically significant higher occurrence of the RL suture failure (p<0.05) was reported and there was a need to perform partial medial meniscectomy (p<0.05). The ACL graft failure was observed in 2 patients (4.7%) in Group 1 and in 3 patients (8.3%) in Group 2 (p>0.05). 31 evaluated patients (73.8%) from Group 1 and 24 patients (66.7%) from Group 2 (p>0.05) returned to the pre-injury level of sports activities. DISCUSSION When comparing the outcomes of individual techniques of the RL repair published in recent literature with our conclusions, we may state that the results of subjective as well as objective criteria achieved were similar to those reported by other authors worldwide. No study has so far been published which would compare the outcomes of the by us presented two surgical techniques of the RL suture in an ACL-deficient knee with a minimum follow-up of 24 months. CONCLUSIONS Both the surgical techniques of unstable RL repair in combination with the ACLR using a tendon graft result in a statistically significant improvement of clinical outcomes postoperatively. In Group 2, with the all-inside RL repair, a statistically significant higher failure rate of RL repair was confirmed as well as the need to perform secondary partial meniscectomy compared to Group 1. Key words: RAMP lesion, ACL-deficient knee, unstable medial meniscus lesion, repair of meniscus, all-inside technique, posteromedial technique, ACL reconstruction.

[Effect of a Single Dose of Tranexamic Acid Administered during Anterior Cruciate Ligament Reconstruction Using Hamstrings: a Randomized Clinical Study]. / Efekt jednorázového podání kyseliny tranexamové pri rekonstrukci predního zkrízeného vazu hamstringy: randomizovaná klinická studie.

PURPOSE OF THE STUDY Anterior cruciate ligament reconstruction is one of the most common reconstruction surgeries. The unintended consequences of the surgery are hemarthrosis, blood loss, knee swelling and postoperative pain. The purpose of the study was to evaluate the effect of a single dose of intravenous tranexamic acid (TXA) on the postoperative parameters and functional status of the knee joint 3 months after surgery. MATERIAL AND METHODS It is a prospective randomised clinical study. An intravenous injection of TXA equivalent to 15 mg/kg in 100 ml of saline solution was administered to the test group during the surgery (20 minutes before the end of the surgery). The control group was administered 100 ml of saline solution without TXA. In both groups, the following parameters were evaluated preoperatively and postoperatively (on Day 1 and Day 10 and at 1 month and 3 months): thigh circumference at 1 cm above the patella, Coupens and Yates (CY) score for swelling, and pain score (VAS). At 24 hours after the surgery, the blood loss (secretion into the drain) and decrease in hemoglobin (Hb) and hematocrit (HCT) levels compared to the preoperative levels were assessed. The functional status of the knee joint was assessed based on the Lysholm knee scoring scale and the IKDC subjective knee evaluation form preoperatively, or at 1 and 3 months postoperatively. RESULTS In the test group, a significantly lower blood loss was detected 24 hours after the surgery. The mean difference of 128 ml compared to the control group was both statistically and practically significant (p < 0.001, d =1.42). The test group showed a lower decrease in Hb and HCT levels postoperatively compared to the control group, although with no statistical significance. On the first postoperative day, slightly better results of the thigh circumference at 1 cm above the patella and of the CY score were observed in the test group. However, during the follow-up check performed postoperatively on Day 10, the differences in the thigh circumference at 1 cm above the patella, CY score and pain VAS score were negligible. The differences in the functional status of the knee joint between the two groups ascertained during the check performed 1 month and 3 months after the surgery were insignificant. DISCUSSION Our study, just like other studies, confirms a significant effect of a single dose of intravenous TXA on the volume of blood loss and early postoperative swelling, which are the parameters affecting the early postoperative course. Even though the intervention does not affect the subsequent result of surgery, it can undoubtedly be of benefit perioperatively. There is a fairly limited number of randomised clinical studies on this topic in literature, with most of them published in the last 7 years. Further research should, among other things, optimise the protocol and identify a suitable candidate for TXA administration in patients undergoing an ACL reconstruction. CONCLUSIONS Our study confirmed the positive effect of a single dose of intravenous TXA during the reconstruction of anterior cruciate ligament using hamstrings on early postoperative blood loss and early postoperative swelling, which can have a positive effect on wound healing and prevent postoperative complications. Therefore, in agreement with available literature, we recom mend administering a single dose of intravenous TXA in ACL reconstruction, unless there is a contraindication to this therapy. Key words: anterior cruciate ligament reconstruction, hamstrings tranexamic acid, single intravenous administration, clinical evaluation.

[Benefits of the Acetabular Microfracture Technique in Arthroscopic Treatment of Chondral Defects in Femoroacetabular Impingement Syndrome: Two-Year Results of a Multicenter Prospective Randomized Study]. / Prínos provedení mikrofraktur acetabula pri artroskopické terapii chondrálních defektu u femoroacetabulárního impingement syndromu: dvouleté výsledky multicentrické prospektivní randomizované studie.

PURPOSE OF THE STUDY Two-year clinical results of a multicenter prospective randomized study in patients with arthroscopically treated Femoro - acetabular Impingement syndrome and concurrently performed microfracture for grade IV chondral lesions of the acetabulum. MATERIAL AND METHODS The study evaluated a group of 55 patients of the originally enrolled 92 patients with the underlying diagnosis of FAI syndrome with intraoperatively confirmed grade IV acetabular chondropathy of up to 4 cm2 in size, who had undergone a comprehensive hip arthroscopy (correction of structural cam-type and/or pincer-type deformity, labral refixation or partial labral resection etc.) performed by two experienced surgeons. The patients were randomized intraoperatively using a closed envelope method into two groups. In Group 1 (31 patients), microfractures for chondral defects was performed, while in Group 2 the patients underwent a defect debridement procedure only. The studied group included a total of 7 professional and 48 recreational athletes (33 men and 22 women), with the mean age of 34.4 in Group 1 and 31.1 in Group 2. Preoperatively and 6, 12 and 24 months postoperatively the modified Harris Hip Score (mHHS) parameters and VAS score were evaluated and also revision surgeries, conversion to endoprosthesis, and occurrence of complications were recorded. RESULTS Preoperatively, no statistical difference between the two groups was found in the studied parameters (mHHS and VAS). Postoperatively (after 6, 12 and 24 months), in both groups a statistically significant increase in mHHS and VAS score was reported. When comparing the mHHS parameter at individual evaluated times in Group 1 and Group 2, a statistically significant difference was confirmed at 12 and 24 months after surgery (P < 0.001), namely in favour of Group 1. At 6 months postoperatively, no statistically significant difference in this parameter between the two groups was confirmed (P = 0.068). When comparing the VAS score parameter in these two groups at individual times, no statistically significant difference was confirmed at 6 and 12 months after surgery (P= 0.83 / P= 0.39). A statistically significant difference in the VAS score parameter was observed only at 24 months after surgery, namely in favour of Group 1 (P< 0.037). In the course of the follow-up period, altogether 3 patients (2 patients from Group 1) were indicated for revision hip arthroscopy and in 1 female patient an endoprosthesis was implanted. No severe intraoperative or postoperative complications were observed. DISCUSSION In agreement with other authors worldwide, the arthroscopic treatment of FAI syndrome, if indicated and performed correctly, was confirmed to improve the clinical condition of patients postoperatively, regardless of the technique used in treating the chondral defect. Based on our results as well as conclusions of other world authors, in treating the grade IV defects of smaller size it is appropriate, in treating the cartilage, to prefer the microfracture surgery, which is less demanding both technically and financially and contrary to mere debridement allows to fill the original defect by fibrocartilage tissue. CONCLUSIONS The benefits of the acetabular microfracture in patients with the FAI syndrome treated arthroscopically were confirmed. A statistically significant difference between the two studied groups was reported in the mHHS parameter at 12 and 24 months after surgery and also in the VAS parameter at 24 months in favour of the group with performed microfracture. In both the studied groups, the arthroscopy resulted in a statistically significant improvement of the assessed quality of life parameters. Key words: hip arthroscopy, femoroacetabular impingement syndrome, chondral defect, microfracture, abrasive chondroplasty.

Overexpression of Substance P in pig airways increases MUC5AC through an NF-kß pathway.

Substance P (SP) is a tachykinin that regulates airway mucous secretion in both health and disease. Our study aimed to determine whether overexpression of SP without pre-existing inflammation was sufficient to induce changes in mucin secretion and transport in small airways. Utilizing porcine precision-cut lung slices, we measured the impact of AAV-mediated overexpression of SP on airway physiology ex vivo. Immunofluorescence signal intensity for MUC5AC was significantly increased in SP-overexpressed precision-cut lung slices compared to GFP controls. No difference in MUC5B signal intensity between treatments was detected. SP-overexpressed precision-cut lung slices also exhibited decreased IL10 mRNA, an important inhibitor of mucous cell metaplasia. Overt deficits in mucociliary transport were not noted, though a trend for decreased mean transport speed was detected in methacholine-challenged airways overexpressing SP compared to GFP controls. Pharmacologic inhibition of the NF-kß pathway abrogated the effects of overexpression of SP on both MUC5AC and IL10. Collectively, these data suggest that overexpression of SP in the absence of existing inflammation increases MUC5AC via activation of the NF-kß pathway. Thus, these data further highlight SP as a key driver of abnormal mucous secretion and underscore NF-kß signaling as a pathway of potential therapeutic intervention.

[Incidence, Morphology and Clinical Significance of Hill-Sachs Lesions in Shoulder Instability - CT Scan Evaluation of the Group of Patients]. / Incidence, morfologie a klinický význam HillovýchSachsových lézí u nestabilních ramenních kloubu ­ CT hodnocení souboru pacientu.

PURPOSE OF THE STUDY Shoulder instability is often times accompanied by associated injuries caused by the humeral head displacement. These are primarily bone lesions on the head and socket of the glenohumeral joint. The purpose of this study was to evaluate the frequency, morphology and clinical significance of bone lesions in shoulder instabilities in a group of patients operated in our department for glenohumeral instability between 2012 and 2019. MATERIAL AND METHODS The ongoing evaluation included 373 patients with trauma and habitual instability who had undergone surgery in our department in the period from 2012 to 2019. All patients underwent a preoperative 3D CT scan of the shoulder joint. Subsequently, the morphology and clinical significance of individual bone lesions were evaluated based on the older Burkhart s concept of engaging/nonengaging lesions and the newer concept of glenoid track by Yamamoto and Di Giacomo of 2007, 2014 or 2020. RESULTS The frequency of Hill-Sachs lesion was 83.4% (311) in our group of patients. In nearly two thirds (211 cases) also a bone defect on glenoid was detected (59.3%). When comparing the basic types of instabilities, in the TUBS group the Hill-Sachs lesions were present up to twice as often as in the group with AMBRI instability. Clinically significant Hill-Sachs lesions according to the older concept of engaging/ nonengaging lesions of Burkhart were reported in 104 cases (34%). Clinically significant lesions according to the newer concept of Yamamoto and DiGiacomo (the so-called off-track lesions) were observed in 173 cases (55.6%). Classified as critical were the clinically insignificant lesions (the so-called on-track lesions), which by their location were near the glenoid track. These lesions were found in 80 patients. After adding up the significant (off-track) and critical on-track lesions, we arrived at 253 (81.4%) clinically significant lesions based on the updated Yamamoto concept. DISCUSSION The frequency of Hill-Sachs lesions and glenoid defects identified by us is close to the upper limit of the range described in literature (8 to 100%). Based on the recent study by Yamamoto, added to these defects were the so-called peripheral ontrack defects, the clinical significance of which is currently indisputable. The oldest classification into engaging/nonengaging lesions revealed only 34% of the significant lesions, but this concept does not evaluate the glenoid defect. The newer concept by Yamamoto/DiGiacomo resulted in detecting 55.6% of significant Hill-Sachs lesions. The latest modification of the glenoid track of 2020, which includes also the on-track lesions in the critical zone among the significant lesions, in our group of patients classified 81% of lesions as clinically significant. CONCLUSIONS Our study confirmed the very frequent occurrence of clinically significant Hill-Sachs lesions in shoulder instabilities. Therefore, for the sake of successful shoulder stabilisation surgery detailed preoperative planning with 3D CT of the shoulder joint and evaluation of the associated bone lesions are necessary. The highest detection of clinically significant lesions was achieved by the latest modification of the glenoid track concept. Future studies will have to prove the effect of this classification on the result of surgical treatment. Key words: shoulder instability, glenoid track; bone defects, Hill-Sachs lesion; bipolar lesions; 3D CT evaluation.