Complicated anorectal sepsis: Validation of scoring system for predicting anorectal sepsis severity

Anorectal sepsis is a common and potentially serious medical condition characterized by infection and inflammation of the anal canal and surrounding tissues. However, the lack of standardized and comprehensive scoring systems specifically tailored for predicting the severity of anorectal sepsis poses challenges in clinical practice. This study aimed to develop and validate a scoring system for predicting the severity of anorectal sepsis by incorporating relevant patient factors. A retrospective cohort study was conducted at Mansoura University Hospital, a tertiary care center, over a period of 5 years. The study population consisted of 330 patients diagnosed with anorectal sepsis during the study period. A scoring system was developed using multiple variables, with each variable assigned a specific score based on its clinical significance and weight in predicting disease severity. The developed scoring system's predictive performance was evaluated using receiver operating characteristic (ROC) analysis, calculating the area under the ROC curve to assess discriminative ability. Descriptive statistics were used to summarize the demographic and clinical characteristics of the study population. Chi-square tests or t tests were performed to assess differences between non-severe and severe anal sepsis groups. The scoring system consisted of 12 variables, with a maximum total score of 18. The logistic regression analysis revealed significant associations between localized swelling, presentation within 72 hours, multiple drainage sessions, and severe anorectal sepsis. The ROC analysis showed an area under the curve of 0.85, indicating good discriminative ability of the scoring system. The scoring system was developed and validated in a single center, which may limit its generalizability to other settings. The scoring system demonstrated good predictive performance and can be a valuable tool for clinicians in assessing disease severity, guiding treatment decisions, and identifying high-risk patients.

Examining the Applicability of Surgical Coaching Rules for Resident Autonomy in Non-teaching Hospitals

INTRODUCTION

This retrospective study aims to analyze the impact of standardized rules for teaching in university hospitals on surgical resident autonomy and patient safety, as measured by patient outcomes, and also examines the learning curves for residents and their impact on patient outcomes in a non-teaching hospital.

METHODS

The data for the study was collected retrospectively from medical records of 2000 adult patients who went through surgical procedures from January 2020 to December 2022. Participants were categorized into two groups based on the supervision level provided by attending surgeons and residents. Appropriate statistical methods were used to analyze the data.

RESULTS

It was observed that operative times of cases handled by both attending and resident surgeons were less than those handled by residents alone. On the other hand, the former group had a significantly higher burden of comorbidities and higher rate of perioperative complications than the latter. These results have important implications for the training of medical residents and the overall delivery of healthcare services in university hospitals.

CONCLUSION

The findings will also help towards better understanding of the effectiveness of these rules and their potential for improving the quality of care provided by residents in these settings.

Multi-level 3D genome organization deteriorates during breast cancer progression

Breast cancer entails intricate alterations in genome organization and expression. However, how three-dimensional (3D) chromatin structure changes in the progression from a normal to a breast cancer malignant state remains unknown. To address this, we conducted an analysis combining Hi-C data with lamina-associated domains (LADs), epigenomic marks, and gene expression in an in vitro model of breast cancer progression. Our results reveal that while the fundamental properties of topologically associating domains (TADs) remain largely stable, significant changes occur in the organization of compartments and subcompartments. These changes are closely correlated with alterations in the expression of oncogenic genes. We also observe a restructuring of TAD-TAD interactions, coinciding with a loss of spatial compartmentalization and radial positioning of the 3D genome. Notably, we identify a previously unrecognized interchromosomal insertion event, wherein a locus on chromosome 8 housing the MYC oncogene is inserted into a highly active subcompartment on chromosome 10. This insertion leads to the formation of de novo enhancer contacts and activation of the oncogene, illustrating how structural variants can interact with the 3D genome to drive oncogenic states. In summary, our findings provide evidence for the degradation of genome organization at multiple scales during breast cancer progression revealing novel relationships between genome 3D structure and oncogenic processes.

PML modulates epigenetic composition of chromatin to regulate expression of pro-metastatic genes in triple-negative breast cancer

The promyelocytic leukemia (PML) protein organizes nuclear aggregates known as PML nuclear bodies (PML-NBs), where many transcription factors localize to be regulated. In addition, associations of PML and PML-NBs with chromatin are described in various cell types, further implicating PML in transcriptional regulation. However, a complete understanding of the functional consequences of PML association to DNA in cellular contexts where it promotes relevant phenotypes is still lacking. We examined PML chromatin association in triple-negative breast cancer (TNBC) cell lines, where it exerts important oncogenic functions. We find that PML associates discontinuously with large heterochromatic PML-associated domains (PADs) that contain discrete gene-rich euchromatic sub-domains locally depleted of PML. PML promotes heterochromatic organization in PADs and expression of pro-metastatic genes embedded in these sub-domains. Importantly, this occurs outside PML-NBs, suggesting that nucleoplasmic PML exerts a relevant gene regulatory function. We also find that PML plays indirect regulatory roles in TNBC cells by promoting the expression of pro-metastatic genes outside PADs. Our findings suggest that PML is an important transcriptional regulator of pro-oncogenic metagenes in TNBC cells, via transcriptional regulation and epigenetic organization of heterochromatin domains that embed regions of local transcriptional activity.

Cellular and Genomic Features of Muscle Differentiation from Isogenic Fibroblasts and Myoblasts

The ability to recapitulate muscle differentiation in vitro enables the exploration of mechanisms underlying myogenesis and muscle diseases. However, obtaining myoblasts from patients with neuromuscular diseases or from healthy subjects poses ethical and procedural challenges that limit such investigations. An alternative consists in converting skin fibroblasts into myogenic cells by forcing the expression of the myogenic regulator MYOD. Here, we directly compared cellular phenotype, transcriptome, and nuclear lamina-associated domains (LADs) in myo-converted human fibroblasts and myotubes differentiated from myoblasts. We used isogenic cells from a 16-year-old donor, ruling out, for the first time to our knowledge, genetic factors as a source of variations between the two myogenic models. We show that myo-conversion of fibroblasts upregulates genes controlling myogenic pathways leading to multinucleated cells expressing muscle cell markers. However, myotubes are more advanced in myogenesis than myo-converted fibroblasts at the phenotypic and transcriptomic levels. While most LADs are shared between the two cell types, each also displays unique domains of lamin A/C interactions. Furthermore, myotube-specific LADs are more gene-rich and less heterochromatic than shared LADs or LADs unique to myo-converted fibroblasts, and they uniquely sequester developmental genes. Thus, myo-converted fibroblasts and myotubes retain cell type-specific features of radial and functional genome organization. Our results favor a view of myo-converted fibroblasts as a practical model to investigate the phenotypic and genomic properties of muscle cell differentiation in normal and pathological contexts, but also highlight current limitations in using fibroblasts as a source of myogenic cells.

Gene Regulatory Interactions at Lamina-Associated Domains

The nuclear lamina provides a repressive chromatin environment at the nuclear periphery. However, whereas most genes in lamina-associated domains (LADs) are inactive, over ten percent reside in local euchromatic contexts and are expressed. How these genes are regulated and whether they are able to interact with regulatory elements remain unclear. Here, we integrate publicly available enhancer-capture Hi-C data with our own chromatin state and transcriptomic datasets to show that inferred enhancers of active genes in LADs are able to form connections with other enhancers within LADs and outside LADs. Fluorescence in situ hybridization analyses show proximity changes between differentially expressed genes in LADs and distant enhancers upon the induction of adipogenic differentiation. We also provide evidence of involvement of lamin A/C, but not lamin B1, in repressing genes at the border of an in-LAD active region within a topological domain. Our data favor a model where the spatial topology of chromatin at the nuclear lamina is compatible with gene expression in this dynamic nuclear compartment.

Local euchromatin enrichment in lamina-associated domains anticipates their repositioning in the adipogenic lineage

Background

Interactions of chromatin with the nuclear lamina via lamina-associated domains (LADs) confer structural stability to the genome. The dynamics of positioning of LADs during differentiation, and how LADs impinge on developmental gene expression, remains, however, elusive.

Results

We examined changes in the association of lamin B1 with the genome in the first 72 h of differentiation of adipose stem cells into adipocytes. We demonstrate a repositioning of entire stand-alone LADs and of LAD edges as a prominent nuclear structural feature of early adipogenesis. Whereas adipogenic genes are released from LADs, LADs sequester downregulated or repressed genes irrelevant for the adipose lineage. However, LAD repositioning only partly concurs with gene expression changes. Differentially expressed genes in LADs, including LADs conserved throughout differentiation, reside in local euchromatic and lamin-depleted sub-domains. In these sub-domains, pre-differentiation histone modification profiles correlate with the LAD versus inter-LAD outcome of these genes during adipogenic commitment. Lastly, we link differentially expressed genes in LADs to short-range enhancers which overall co-partition with these genes in LADs versus inter-LADs during differentiation.

Conclusions

We conclude that LADs are predictable structural features of adipose nuclear architecture that restrain non-adipogenic genes in a repressive environment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13059-022-02662-6.

Patient radiation dose from x-ray guided endovascular aneurysm repair: a Monte Carlo approach using voxel phantoms and detailed exposure information

Endovascular aneurysm repair (EVAR) is a well-established minimally invasive technique that relies on x-ray guidance to introduce a stent through the femoral artery and manipulate it into place. The aim of this study was to estimate patient organ and effective doses from EVAR procedures using anatomically realistic computational phantoms and detailed exposure information from radiation dose structured reports (RDSR). Methods: Lookup tables of conversion factors relating kerma area product (P_KA) to organ doses for 49 different beam angles were produced using Monte Carlo simulations (MCNPX2.7) with International Commission on Radiological Protection (ICRP) adult male and female voxel phantoms for EVAR procedures of varying complexity (infra-renal, fenestrated/branched and thoracic EVAR). Beam angle specific correction factors were calculated to adjust doses according to x-ray energy. A MATLAB function was written to find the appropriate conversion factor in the lookup table for each exposure described in the RDSR, perform energy corrections and multiply by the respective exposure P_KA. Using this approach, organ doses were estimated for 183 EVAR procedures in which RDSRs were available. A number of simplified dose estimation methodologies were also investigated for situations in which RDSR data are not available. Results: Mean estimated bone marrow doses were 57 (range: 2-247), 86 (2-328) and 54 (8-250) mGy for infra-renal, fenestrated/branched and thoracic EVAR, respectively. Respective effective doses were 27 (1-208), 54 (1-180) and 37 (5-167) mSv. Dose estimates using non-individualised, average conversion factors, along with those produced using the alternative Monte Carlo code PCXMC, yielded reasonably similar results overall, though variation for individual procedures could exceed 100% for some organs. In conclusion, radiation doses from x-ray guided endovascular aneurysm repairs are potentially high, though this must be placed in the context of the life sparing nature and high success rate for this procedure.

The therapeutic effect of probiotics on rheumatoid arthritis: a systematic review and meta-analysis of randomized control trials

Rheumatoid arthritis is an autoimmune disease in which probiotics appears to have an immune modulating action along with decreased inflammatory process. Therefore, we aim to investigate the efficacy of probiotics as an adjuvant therapy for rheumatoid arthritis. A comprehensive literature search was performed using nine databases including PubMed and Web of Science. Interesting data was extracted and meta-analyzed. We assessed the risk of bias using Cochrane Collaboration's tool. The protocol was registered in PROSPERO (CRD 42016036769). We found nine studies involving 361 patients who met our eligibility criteria. Our meta-analysis indicated that pro-inflammatory cytokine IL-6 was significantly lower in the probiotics compared with the placebo group (standardized mean difference = - 0.708; 95% confidence interval (CI) - 1.370 to 0.047, P = 0.036). However, there was no difference between probiotics and placebo in disease activity score (mean difference 0.023; 95% CI - 0.584 to 0.631, P = 0.940). Probiotics lowered pro-inflammatory cytokines IL-6 in RA; however, its clinical effect is still unclear. Hence, many high-quality randomized controlled trials (RCTs) are still needed to prove this effect.