Unsupervised Segmentation of Knee Bone Marrow Edema-like Lesions Using Conditional Generative Models.

Bone marrow edema-like lesions (BMEL) in the knee have been linked to the symptoms and progression of osteoarthritis (OA), a highly prevalent disease with profound public health implications. Manual and semi-automatic segmentations of BMELs in magnetic resonance images (MRI) have been used to quantify the significance of BMELs. However, their utilization is hampered by the labor-intensive and time-consuming nature of the process as well as by annotator bias, especially since BMELs exhibit various sizes and irregular shapes with diffuse signal that lead to poor intra- and inter-rater reliability. In this study, we propose a novel unsupervised method for fully automated segmentation of BMELs that leverages conditional diffusion models, multiple MRI sequences that have different contrast of BMELs, and anomaly detection that do not rely on costly and error-prone annotations. We also analyze BMEL segmentation annotations from multiple experts, reporting intra-/inter-rater variability and setting better benchmarks for BMEL segmentation performance.

Effect Of Eight Hours Per Day Of Intermittent Self Prone Positioning For Seven Days On The Severity Of Covid-19 Pneumonia/ Acute Respiratory Distress Syndrome.

BACKGROUND: Prone positioning improves ventilation-perfusion mismatch, distribution of gravitational gradient in pleural pressure, and oxygen saturation significantly in patients with Covid pneumonia. We aimed to find out the efficacy of eight hours per day of intermittent selfprone positioning for seven days in patients affected with COVID-19 pneumonia/ ARDS. METHODS: This Randomized Clinical Trial was conducted in the Covid isolation wards of Ayub Teaching Hospital, Abbottabad. Patients suffering from COVID-19 pneumonia/ ARDS were enrolled with permuted block randomization into a control and an experimental group each consisting of 36 patients. Parameters of Pneumonia Severity Index (PSI) score along with other sociodemographic data was noted on a preformed structured questionnaire. Death was confirmed by requesting the death certificate of patients on the 90th day of enrolment. Data Analysis was done with SPSS Version 25. Tests of significance were applied to calculate the difference in the patients of the two groups with respect to respiratory physiology and survival. RESULTS: The mean age of the patients was 63.79±15.26 years. A total of 25 (32.9%) male and 47 (61.8%) female patients were enrolled. Statistically significant improvement was found in the respiratory physiology of the patients at 7th and 14th DOA between the groups. Pearson Chi-Square test of significance showed a difference in mortality between the two groups at 14th DOA (pvalue=0.011) but not at 90th DOA (p-value=0.478). Log Rank (Mantel-Cox) test of significance, applied on the Kaplan Meier curve and showed no statistically significant difference among the groups based on the survival of the patients. (p-value=0.349). CONCLUSIONS: Early transient improvement in respiratory physiology and mortality does occur with 8 hours of self-prone positioning for seven days but there is no effect on the 90-day survival of the patients. Thus, the impact of the manoeuvre on improving survival needs to be explored with studies having an application of the manoeuvre for a longer duration and period.

Exocrine gland structure-function relationships.

Fluid secretion by exocrine glandular organs is essential to the survival of mammals. Each glandular unit within the body is uniquely organized to carry out its own specific functions, with failure to establish these specialized structures resulting in impaired organ function. Here, we review glandular organs in terms of shared and divergent architecture. We first describe the structural organization of the diverse glandular secretory units (the end-pieces) and their fluid transporting systems (the ducts) within the mammalian system, focusing on how tissue architecture corresponds to functional output. We then highlight how defects in development of end-piece and ductal architecture impacts secretory function. Finally, we discuss how knowledge of exocrine gland structure-function relationships can be applied to the development of new diagnostics, regenerative approaches and tissue regeneration.