Indwelling stents cause obstruction and induce ureteral injury and fibrosis in a porcine model.

OBJECTIVES: To investigate global changes in ureters at the transcriptional, translational and functional levels, both while stents are indwelling and after removal and recovery, and to study the effects of targeting pathways that play a potential role. METHODS: Pig ureters were stented for varying amounts of time (48 h, 72 h, 14 days) and the impact on peristalsis, dilatation and hydronephrosis were assessed. RNAseq, proteomic, histological and smooth muscle (SM) function analyses were performed on ureteric and kidney tissues to assess changes induced by stenting and recovery. Pathway analysis was performed using Ingenuity Pathway Analysis software. To study the impact of possible interventions, the effects of erythropoeitin (EPO) and a Gli1 inhibitor were assessed. RESULTS: Stenting triggers massive ureteric dilatation, aperistalsis and moderate hydronephrosis within 48 h. Pathways associated with obstruction, fibrosis and kidney injury were upregulated by stenting. Increased expression of GLI1, clusterin-α (a kidney injury marker) and collagen 4A2 (a fibrosis marker) was found in stented vs contralateral unstented ureters. EPO did not improve peristalsis or contraction force but did decrease non-purposeful spasming seen exclusively in stented ureters. Tamsulosin administration increased contractility but not rate of peristalsis in stented ureters. CONCLUSIONS: Ureters respond to stents similarly to how they respond to an obstruction, that is, with activation of pathways associated with hydronephrosis, fibrosis and kidney injury. This is driven by significant dilatation and associated ureteric SM dysfunction. EPO and tamsulosin induced mild favourable changes in SM physiology, suggesting that targeting specific pathways has potential to address stent-induced complications.

Interlayer Defect Detection in Intra-Ply Hybrid Composite Material (GF/CF) Using a Capacitance-Based Sensor.

Combining two types of reinforcement fiber in a common matrix may lead to different failure modes such as micro-cracks between the layers when the structure is subjected to lower stress levels. Real-time damage detection should be integrated into the hybrid composite structure to provide structural integrity and mitigate this problem. This paper outlines the working mechanisms and the fabrication of an integrated capacitive sensor in an intra-ply hybrid composite (2 × 2 twill weave). Uniaxial tensile and flexural tests were conducted to characterize the proposed sensor and provide self-sensing functionality (smart structure). The sensitivity and repeatability of the capacitive sensor were measured to be around 1.3 and 185 µΔC/Co, respectively. The results illustrate that onset of damage between layers can be detected by in situ monitoring. It can be seen that the initial damage was detected at the turning point where the relative change in capacitance begins to reduce while the load increases. Finite element modeling was also constructed to analyze the test results and explain the reasons behind the turning point. It was shown that the carbon yarns experienced high transverse shear stress (τxz) in the crimp region, leading to inter-fiber cracks.

Can Fasting Blood Sugar be Used as an Indicator of Long-Term Diabetic Control Instead of Estimated Average Glucose?

BACKGROUND: Diabetes mellitus is a chronic illness that is a worldwide issue. HbA1c has been used to monitor glycemic control in patients with diabetes for many years. Although HbA1c measurement is needed for calculating estimated average blood glucose (eAG), it is now recommended that eAG is used instead of HbA1c for expression of blood glucose control and communication with patients and health care providers. This study, investigated fasting blood glucose (FBS) as an indicator of overall chronic blood sugar control by assessing the correlation between FBS with eAG derived from HbA1c. METHODS: The blood samples for HbA1c assay were collected in EDTA tubes and were analyzed by an HPLC analyzer (G8 Tosoh, Japan). Blood samples for FBS were collected in serum separator tubes, transported, and centrifuged for 15 minutes at 3,000 g. FBS levels were determined in serum samples with the enzymatic hexokinase method by a clinical chemistry analyzer (Architect 8000, Abbott, USA). RESULTS: Statistical analysis was performed on 1,740 patients with type 2 diabetes mellitus with HbA1c levels above 6.5 mmol/L. The difference between FBS (9.3 ± 3.7 mmol/L) and eAG (11.14 ± 2.7 mmol/L) was statistically signif-icant (p < 0.0001). The correlation coefficient between FBS and eAG was r = 0.65 (95% CI; 0.62 - 0.69), with a p-value < 0.0001. While the correlation coefficient between FBS and eAG at HbA1c < 6.5% was r = 0.251 (95% CI, 0.16 - 0.34), with a significant p-value of < 0.00001. The combined data, standard deviation (SD), median, and interquartile range of eAG and FBS for all of the diabetic groups (n = 2,315), were 10.1 ± 3.00 mmol/L, 9.5 mmol/L, and 7.75 - 12.03 mmol/L for eAG, respectively. Similarly, these values were 8.5 ± 3.6 mmol/L, 7.5 mmol/L, and 6.0 - 10.00 mmol/L for FBS, respectively. CONCLUSIONS: We concluded that there is a moderate and significant positive correlation between fasting blood sugar and the estimated average blood glucose derived from HbA1c. Although FBS might be helpful for daily monitoring of diabetes. Further studies must be conducted to provide solid results to support that FBS and its derived variable eAG can replace HbA1c as an indicator of long-term overall control of T2DM patients.

The Use of Infrared Auto Refractometer for Meibomian Gland Imaging.

Introduction This study proposes the utility of an infrared auto refractometer for meibography and compares miebographs obtained by an auto refractometer to meibographs obtained by a designated meibography machine. Methods A prospective observational comparative study of meibographs of patients with clinical signs of meibomian gland dysfunction (MGD) using a designated meibography machine and an infrared auto refractometer. Five masked, experienced interpreters graded the images of the two machines. The Kappa test was used to calculate Intra-rater and inter-rater agreements between the meibography machine and automated refractor grading of meibomian gland dysfunction. Results High-quality photos of all 30 eyes delineating the meibomian glands (MG) were successfully obtained with both the meibography machine and the autorefractor. Both methods had a good intra-rater agreement (κ= 0.667 to 0.784, average 0.738). Poor to fair interrater agreement was noticed in the grading of autorefractor images (k= -0.030 to 0.343, average 0.092) and poor to moderate agreements between investigators for meibography machine images (K= -0.016 to 0.420, average 0.173). Conclusion A commercially available auto refractometer could capture high-quality non-contact IR digital meibographs.

Ureteral Obstruction Promotes Ureteral Inflammation and Fibrosis.

BACKGROUND: Hydronephrosis and renal impairment may persist even after relieving an obstruction, particularly in cases of chronic obstruction. Obstruction can cause fibrotic changes of the ureter, potentially contributing to long-term kidney damage. OBJECTIVE: To characterise pathophysiological changes of obstructed ureters with focus on inflammatory responses triggering fibrosis and potential impairment of ureteral function. DESIGN, SETTING, AND PARTICIPANTS: Eighty-eight mice were randomly assigned to unilateral ureteral obstruction (UUO) for 2 d, UUO for 7 d, and UUO for 7 d followed by 8 d of recovery, or a control group (no prior surgical intervention). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Peristaltic rate was determined over 2 min by direct visualisation with a microscope, while hydronephrosis was assessed by ultrasound. Obstructed and contralateral ureters were harvested, and underwent histopathological evaluation. We quantified 44 cytokines/chemokines, and five matrix metalloproteases using Luminex technology. Cell composition was characterised via immunofluorescence. Statistical significance was assessed using Welch analysis of variance, Kruskal-Wallis test, and Dunnett's T3 multiple comparison test. RESULTS AND LIMITATIONS: Obstruction resulted in hydronephrosis and significantly impaired peristalsis. Marked fibrosis was observed in lamina propria, muscle layer, and adventitia. Connective tissue in obstructed ureters showed hyperaemia and leucocyte infiltration. Unsupervised hierarchical clustering demonstrated different cytokine/chemokine patterns between groups. Ureters obstructed for 7 d followed by recovery were notably different from other groups. Inflammatory cytokines, chemoattractants, and matrix metalloproteases increased significantly in obstructed ureters. Contralateral unobstructed ureters showed significantly increased levels of chemokines and matrix metalloproteases. Immunofluorescence confirmed activation of T cells, Th1 and Th2 cells, and M1 macrophages in obstructed and contralateral ureters, and a shift to M2 macrophages following prolonged obstruction. CONCLUSIONS: Ureteral obstruction triggers severe inflammation and fibrosis, which may irreversibly impair ureteral functionality. Function of the unobstructed contralateral ureter may be regulated by a systemic immune response as a result of the obstruction. PATIENT SUMMARY: Here, we studied in more detail the way the ureter responds to being blocked. We conclude that a strong immune response is activated by the blockage, leading to changes in the structure of the ureter possibly impacting function, which may not be reversible. This immune response also spreads to the opposite ureter, possibly allowing it to change its function to compensate for the reduced functionality of the blocked ureter.

Prevalence and Risk Factors Associated With Acute Kidney Injury After Transcatheter Aortic Valve Replacement at a Tertiary Hospital in Riyadh, Saudi Arabia.

BACKGROUND: Despite recent advancements in techniques, peri- and post-procedural complications still pose a significant challenge in the high-risk transcatheter aortic valve replacement (TAVR) patient population. This study aims to investigate and assess the prevalence of acute kidney injury (AKI) following TAVR, and to identify the risk factors associated with its occurrence. METHODS: We conducted the study at King Abdulaziz Medical City, Riyadh, Saudi Arabia from January 2016 to December 2022. We extracted data from electronic medical records. We categorized and compared patients based on their diagnosis of AKI+ following TAVR, or their absence of AKI- after the procedure. RESULTS: The study included a total of 344 patients who underwent TAVR. The mean age of the patients was 77.8 ± 8.9 years, 61.8% were male, and the average body mass index was 30.5±7.0. In terms of comorbidities, 70.8% of the patients had diabetes mellitus, 80.5% had hypertension, 8.7% had hypothyroidism, 2.0% had hematological disorders, 23.6% had congestive heart disease, 20.4% had cerebrovascular disease, 4.1% had peripheral vascular disease, 7.3% had cancer, and 34.4% had other comorbidities. The prevalence of AKI was 60 (17.50%) following the procedure. Cerebrovascular diseases showed a significant association with AKI (OR= 3.381, 95% CI, 1.65-6.91, p = 0.001). Chronic kidney disease has a significant effect on AKI (OR = 2.56, 95%CI, 1.02-6.39, p = 0.044). The creatinine level on Day 0 has a significant association with AKI (OR = 1.01, 95%CI, 1.006-1.017, p = 0.0001). CONCLUSIONS: These findings highlight the importance of assessing and managing these risk factors (cerebrovascular diseases, chronic kidney disease, and creatinine level on Day 0) in TAVR patients to mitigate the occurrence and severity of AKI. By understanding and addressing these factors, healthcare providers can potentially improve patient outcomes and reduce the incidence of AKI-associated TAVR procedures.

Indwelling stents cause severe inflammation and fibrosis of the ureter via urothelial-mesenchymal transition.

To explore the pathways and mechanisms driving inflammation and fibrosis in stented ureters. In total, six healthy female pigs underwent cystoscopic unilateral ureteral stent insertion (6 Fr). After 14 days indwelling time, ureteral tissue was harvested in three pigs, while the remaining three pigs had their stents removed, and were recovered for 7 days. Three separate pigs served as controls. Tissue from stented and contralateral ureters was analysed histologically to evaluate tissue remodelling and classify the degree of inflammation and fibrosis, while genome, proteome and immunohistochemistry analysis was performed to assess changes at the transcriptional and translational levels. Finally, immunofluorescence was used to characterize the cell composition of the immune response and pathways involved in inflammation and fibrosis. Statistical analysis was performed using GraphPad Prism and RStudio for Welch ANOVA, Kruskal-Wallis and Dunnett's T3 multiple comparison test. Stents cause significant inflammation and fibrosis of ureters. Gene set enrichment analysis confirmed fibrotic changes and tissue proliferation and suggests that epithelial-mesenchymal transition is a driver of fibrosis. Moreover, IL-6/JAK/STAT and TNFα via NF-κB signalling might contribute to chronic inflammation promoting a profibrotic environment. Immunostaining confirmed epithelial-mesenchymal transition in the urothelium and NF-κB expression in ureters stented for 14 days. Tissue alterations do not fully recover after 7 days. Histological evaluation showed that contralateral, unstented ureters are affected by mild inflammation. Our study showed that stenting has a significant impact on the ureter. Chronic inflammation and epithelial-mesenchymal transition are drivers of fibrosis, potentially impairing ureteral functionality in the long term. Furthermore, we observed mild inflammation in contralateral, unstented ureters.

Risk Stratification of Differentiated Thyroid Cancer at King Abdullah Specialized Children's Hospital Endocrinology Clinic in Riyadh, Saudi Arabia.

Background Papillary thyroid cancer (PTC), a well-differentiated form of cancer, accounts for the majority of thyroid malignancies, and the incidence of PTC is on the rise. While the rate of PTC recurrence is considered to be low, there are broad spectrums of clinical and biological behavior that can lead to disease recurrence. The American Thyroid Association (ATA) risk stratification system for differentiated thyroid cancer is used as a prognostic tool to guide decision-making and management strategies most likely to achieve a favorable outcome. Aim This study aimed to estimate the prevalence of PTC recurrence in each category of the ATA risk stratification system and determine the appropriate iodine dose to be administered at the King Abdulaziz Medical City Endocrinology Clinic in Riyadh, Saudi Arabia. Methods A cross-sectional retrospective chart review was conducted on adult patients with PTC who underwent thyroidectomy procedures at the King Abdullah Specialized Children's Hospital (KASCH) Endocrinology Clinic in Riyadh between 2015 and 2023. IBM SPSS (Statistical Package for the Social Sciences) version 25 (IBM Corp., Armonk, NY) was used for data analysis. Results Of the 697 patients included in the study, 82.4% were females. About 5% had suffered from PTC recurrence, and 54.4% had low-risk stratification. In addition, more than half (52.1%) had received radioactive iodine (RAI). The recurrence of PTC was significantly associated with age (P = 0.019), ATA risk stratification (P = 0.0001), RAI therapy (P = 0.001), and iodine dosage (P = 0.013). Conclusion Both low PTC recurrence rates and low-risk stratification were observed among the PTC patients. The risk factors relating to PTC recurrence included high-risk stratification, advanced age, RAI therapy, and the dosage of RAI administered.

Controversies associated with ureteral access sheath placement during ureteroscopy.

The use of ureteral access sheaths (UAS) is common practice during routine flexible ureteroscopy procedures. However, debates and concerns continue amongst endourologists on routine UAS placement. UAS placement allows for multiple passages of the ureteroscope, decreases intrarenal pressure, and may improve stone-free rates. However, concerns for the UAS's effectiveness in these claimed benefits and complications related to UAS placement has been documented and investigated by many. In this review, we will discuss the controversies surrounding the placement of UAS during ureteroscopy.

Patient-reported outcomes after breast reconstructive surgery: A prospective cross-sectional study.

BACKGROUND: With advancements in and the evolution of the medical field, several methods and surgical techniques have been developed for breast reconstruction after mastectomy. Generally, we can categorize these strategies into two broad groups: autologous reconstruction and implant-based reconstruction. This study aimed to analyze the satisfaction rate between these groups, considering age, timing of breast reconstruction, body mass index (BMI), major complications, and the need for radiotherapy or chemotherapy. MATERIALS AND METHODS: All the patients who underwent a mastectomy and subsequent breast reconstruction surgery at our institution between August 1, 2013, and August 31, 2017, were invited to complete a BREAST-Q questionnaire. To compare the quality of life and complication rate between the autologous and implant-based reconstruction groups, data were collected from specific patients. All participants completed the Arabic version of the postoperative reconstruction module. RESULTS: Among 61 patients, 43 (70.5%) completed the two domains of the BREAST-Q questionnaire, about the satisfaction with the implanted breast and satisfaction with the surgical outcome. These patients were divided into two groups: autologous (n = 21) and implant-based (n = 22) groups. The mean score of satisfaction with the implanted breast was 43.5 for the autologous group and 39.6 for the implant-based group. For the surgical outcome, the scores for the autologous and implant-based groups were 45.4 and 56.0, respectively. However, there was neither a statistical significance in the satisfaction with the implanted breast nor the surgical outcome between the two groups. CONCLUSION: Although there are many different surgical techniques to reconstruct a breast after mastectomy, there is still no specific surgical method that is perfect or well-suited for all patients undergoing breast reconstruction surgery. In our study, we found that there was no significant difference in satisfaction between the ABR and IBR group.