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Simple Summary: This research considers means of improving the early detection and treatment of colorectal cancer (CRC), a common and deadly form of cancer often identified too late for effective treatment. In our study, we examined AIFM3, VGLL4, and WNT4 in cancerous and healthy tissues at various stages of CRC. We found that these markers behave differently as the cancer advances. AIFM3 appears in healthy tissue and early cancer stages but disappears as the cancer worsens. VGLL4 increases in the affected tissues as the cancer progresses, particularly noticeable from early to more advanced stages. WNT4 is higher in cancerous tissues, but decreases in the supportive tissue surrounding cancer cells as the disease advances. Low VGLL4 levels are linked to better patient survival, unlike the other two markers. This finding suggests that VGLL4 could be useful as an indicator of CRC prognosis, potentially guiding treatment approaches. Background/Objectives: Colorectal cancer (CRC) remains a significant health burden, and its delayed diagnosis at advanced stages leads to poor survival outcome. Detection of known and novel prognostic markers is essential. In this study, the status of likely prognostic markers—the apoptotic inducing factor (AIFM3), vestigial-like family member 4 (VGLL4), and WNT4—was evaluated. Methods: AIFM3, VGLL4, and WNT4 expression in CRC tissues across different stages (Dukes A–D) were analyzed using histological immunofluorescence staining and RNA sequencing analyses. Results: In advanced CRC stages, progressive loss of normal crypt architecture, reduction of goblet cells, and necrotic debris were detected along with differential expression patterns of AIFM3, VGLL4, and WNT4. AIFM3 exhibited high reactivity in the lamina propria of healthy tissue and Dukes A, but this was diminished in advanced CRC stages. VGLL4 expression, initially confined to the lamina propria, increased significantly in the epithelium of Dukes B and C, with a cytoplasmic localization pattern. WNT4 expression was elevated in the CRC epithelium across all stages, contrasting with a significant reduction in lamina propria reactivity. RNA sequencing corroborated these findings, showing significant downregulation of AIFM3 and WNT4 and upregulation of VGLL4 in CRC tissues compared to controls. Expression of AIFM3 and WNT4 showed no correlation with survival outcome, while low VGLL4 expression was correlated with better survival outcome. Conclusions: The results suggest distinct roles for AIFM3, VGLL4, and WNT4 in CRC progression, highlighting only VGLL4 as a potential prognostic marker. Further evaluation of VGLL4 and its specific role in CRC progression remains to be elucidated. [ABSTRACT FROM AUTHOR]

Long-term use of topical prostaglandins might initiate chronic conjunctival inflammation, leading to poor outcomes of glaucoma surgery. The aim of this study was to evaluate the immunoexpression pattern of HSP70, CTGF, SNAIL, aSMA, cMYB, and HIFa in the conjunctiva, episclera, and deep sclera in patients with glaucoma undergoing deep sclerectomy in order to establish an association between staining intensities and prostaglandin F2 (PGF2) treatment. Double immunofluorescence (HSP70, CTGF, SNAIL, aSMA, cMYB, and HIFa) was performed on conjunctiva, episclera, and deep sclera samples, which were obtained from 23 patients treated with PGF2 and 8 patients without PGF2 treatment. When comparing the ocular tissues of patients regarding treatment with PGF2 analogs, we found a significant increase in the immunoexpression of HSP70 in the conjunctival epithelium of patients treated with PGF2 analogs compared to those without PGF2 treatment. These patients also had an increase in SNAIL immunoexpression and a decrease in aSMA immunoexpression in the deep sclera. There were no significant differences in HIFa, CTGF, or cMYB immunoexpression levels between the two groups. Further research into the regulation of these factors in ocular tissues could lead to the development of potential novel therapeutic approaches in glaucoma management. [ABSTRACT FROM AUTHOR]

Precision medicine is a developing trend in oncology, and it includes the prognosis and treatment of advanced-stage ccRCC. New predictive factors and therapeutic targets for this disease are steadily needed. The aim of this study was to explore the tumor expression of inversin as a potential prognostic factor and/or therapeutic target in ccRCC. We compared the expression of inversin between primary ccRCC and normal renal tissues by using immunohistochemistry and rtPCR in our cohort, and we also analyzed publicly available data from the TCGA-KIRC cohort. We found that the expression of inversin was significantly lower in primary tumor tissue, in comparison to solid normal tissue. Data from the KIRC study confirmed that a lower INVS expression level in ccRCC was significantly related with the overall and disease-specific survival, as well as with a shorter progression-free interval (p < 0.05). Four out of ten inversin interactome partners were significantly related with the overall and disease-specific survival in ccRCC. A lower expression of ANKS6 was a negative survival predictor, while a higher expression of NPHP3, DVL1, or DVL3 was related with a lower survival. The expression of INVS and its interactome partners in ccRCC was correlated with the differentiation of the tumor and metastasis. The expression of INVS and its partners was also correlated with tumor leukocyte infiltration and the expression of immune checkpoint genes. The results of this study point to inversin and a distinguished group of its interactome partners as potential prognostic factors in ccRCC, with their predominant involvement in the modulation of the inflammatory infiltration of the tumor microenvironment and a strong relationship with the metastatic potential of the tumor. [ABSTRACT FROM AUTHOR]

Melanoma is the most severe type of skin cancer and among the most malignant neoplasms in humans. With the growing incidence of melanoma, increased numbers of therapeutic options, and the potential to target specific proteins, understanding the basic mechanisms underlying the disease's progression and resistance to treatment has never been more important. LOXL3, SNAI1, and NES are key factors in melanoma genesis, regulating tumor growth, metastasis, and cellular differentiation. In our study, we explored the potential role of LOXL3, SNAI1, and NES in melanoma progression and metastasis among patients with dysplastic nevi, melanoma in situ, and BRAF+ and BRAF− metastatic melanoma, using immunofluorescence and qPCR analysis. Our results reveal a significant increase in LOXL3 expression and the highest NES expression in BRAF+ melanoma compared to BRAF−, dysplastic nevi, and melanoma in situ. As for SNAI1, the highest expression was observed in the metastatic melanoma group, without significant differences among groups. We found co-expression of LOXL3 and SNAI1 in the perinuclear area of all investigated subgroups and NES and SNAI1 co-expression in melanoma cells. These findings suggest a codependence or collaboration between these markers in melanoma EMT, suggesting new potential therapeutic interventions to block the EMT cascade that could significantly affect survival in many melanoma patients. [ABSTRACT FROM AUTHOR]

In hip fracture patients, who are mostly elderly, preexisting anemia can be worsened when combined with trauma and surgery. To this date, there is no unequivocal approach about transfusion thresholds. We analyzed hemoglobin (Hb) and hematocrit (Hct) levels at three time points in surgical patients with proximal femoral fractures (PFF) to see which levels were triggers for transfusions and whether transfusions were related to mortality after hospital discharge. A total of 956 patients were operated on from 1 January 2021 to 31 December 2022 at the University Hospital of Split and included in the study. There were more women (74%); 47% patients had admission Hb < 120 g/L. Transfusion was given preoperatively to 88, intraoperatively to 74 and postoperatively to 309 patients. Transfusion thresholds were as follows: Hb 84 g/L preoperatively, 99 intraoperatively and 83 postoperatively. After hospital discharge, 10.79% of patients died within the 1st month and 23% within 6 months. In the group of non-survivors, 60% of patients had admission Hb ≤ 117 g/L and the proportion of patients transfused preoperatively was two times higher. Preoperative transfusion thresholds could be set to higher levels for patients with surgically treated PFF. However, that could increase mortality even more. Further investigation is necessary. [ABSTRACT FROM AUTHOR]

This study aimed to explore how Dab1 functional silencing influences the expression patterns of different connexins in the developing yotari (yot) mice eyes as potential determinants of retinogenesis. Using immunofluorescence staining, the protein expression of Dab1, Reelin, and connexin 37, 40, 43, and 45 (Cx37, Cx40, Cx43, and Cx45) in the wild-type (wt) and yot eyes at embryonic days 13.5 and 15.5 (E13.5 and E15.5) were analyzed. Different expression patterns of Cx37 were seen between the wt and yot groups. The highest fluorescence intensity of Cx37 was observed in the yot animals at E15.5. Cx40 had higher expression at the E13.5 when differentiation of retinal layers was still beginning, whereas it decreased at the E15.5 when differentiation was at the advanced stage. Higher expression of Cx43 was found in the yot group at both time points. Cx45 was predominantly expressed at E13.5 in both groups. Our results reveal the altered expression of connexins during retinogenesis in yot mice and their potential involvement in retinal pathology, where they might serve as prospective therapeutic targets. [ABSTRACT FROM AUTHOR]

Fetal hypoxia due to placental dysfunction is the hallmark of fetal growth restriction (FGR). Preferential perfusion of the brain (brain-sparing effect), as a part of physiological placental cardiovascular compensatory mechanisms to hypoxia, in FGR was reported. Therefore, the correlation between vascular endothelial growth factor A (VEGF-A) protein expression in the FGR placentas and newborns' early neurological outcome was examined. This study included 50 women with FGR complicated pregnancies and 30 uneventful pregnancies. Fetal hemodynamic parameters, neonatal acid–base status after delivery, placental pathohistology and VEGF-A expression were followed. Early neonatal morphological brain evaluation by ultrasound and functional evaluation of neurological status by Amiel – Tison Neurological Assessment at Term (ATNAT) were performed. VEGF-A protein expression level was significantly higher in the FGR placentas than normal term placentas (Fisher–Freeman–Halton's test, p≤0.001). No statistically significant correlation between placental VEGF-A expression and different prenatal and postnatal parameters was noticed. Whereas the alteration of an early neurological status assessed by ATNAT was found in 58 % of FGR newborns, morphological brain changes evaluated by UZV was noticed in 48 % of cases. No association between the level of placental VEGF-A expression and the early neurological deficits was found. As far as we know this is the first study of a possible connection between VEGF-A protein expression in the FGR placentas and neonates' early neurological outcomes. The lack of correlation between the FGR placental VEGF-A expression and neonates' neurological outcome could indicate that optimal early neurodevelopment may take place due to compensatory mechanism not related to placental VEGF-A expression. [ABSTRACT FROM AUTHOR]

Autophagy is the primary intracellular degradation system, and it plays an important role in many biological and pathological processes. Studies of autophagy involvement in developmental processes are important for understanding various processes. Among them are fibrosis, degenerative diseases, cancer development, and metastasis formation. Diabetic kidney disease is one of the main causes of chronic kidney disease and end-stage renal failure. The aim of this study was to investigate the immunohistochemical expression patterns of LC3B, LAMP2A, and GRP78 during different developmental stages of early-developing human kidneys and in samples from patients with type II diabetes mellitus. During the 7/8th DW, moderate expression of LC3B and LAMP2A and strong expression of GRP78 were found in the mesonephric glomeruli and tubules. In the 9/10th DW, the expression of LC3B and LAMP2A was even more pronounced in the mesonephric tubules. LC3B, LAMP2A, and GRP78 immunoreactivity was also found in the paramesonephric and mesonephric ducts and was stronger in the 9/10th DW compared with the 7/8th DW. In addition, the expression of LC3B, LAMP2A, and GRP78 also appeared in the mesenchyme surrounding the paramesonephric duct in the 9/10th DW. In the 15/16th DW, the expression of LC3B in the glomeruli was weak, that of LAMP2A was moderate, and that of GRP78 was strong. In the tubuli, the expression of LC3B was moderate, while the expression of LAMP2A and GRP78 was strong. The strongest expression of LC3B, LAMP2A, and GRP78 was observed in the renal medullary structures, including developing blood vessels. In postnatal human kidneys, the most extensive LC3B, LAMP2A, and GRP78 expression in the cortex was found in the epithelium of the proximal convoluted tubules, with weak to moderate expression in the glomeruli. The medullary expression of LC3B was weak, but the expression of LAMP2A and GRP78 was the strongest in the medullary tubular structures. Significantly lower expression of LC3B was found in the glomeruli of the diabetic patients in comparison with the nondiabetic patients, but there was no difference in the expression of LC3B in the tubule–interstitial compartment. The expression of LAMP2A was significantly higher in the tubule–interstitial compartments of the diabetic patients in comparison with the nondiabetic patients, while its expression did not differ in the glomeruli. Extensive expression of GRP78 was found in the glomeruli and the tubule–interstitial compartments, but there was no difference in the expression between the two groups of patients. These data give us new information about the expression of LC3B, LAMP2A, and GRP78 during embryonic, fetal, and early postnatal development. The spatiotemporal expression of LC3B, LAMP2A, and GRP78 indicates the important role of autophagy during the early stages of renal development. In addition, our data suggest a disturbance in autophagy processes in the glomeruli and tubuli of diabetic kidneys as an important factor in the pathogenesis of diabetic kidney disease. [ABSTRACT FROM AUTHOR]

Hodgkin lymphoma (HL) is a rare lymphoid neoplasm in which Hodgkin/Reed–Stenberg (HRS) cells are admixed with a population of non-neoplastic inflammatory cells and fibrosis. Dysregulated expressions of cell cycle regulators and transcription factors have been proven as one of the hallmarks of HL. In that context, SATB1 and p16 have been reported as potential regulators of HL progression and survival. However, to date, no studies have assessed the expression levels of SATB1 and p16 in HL in Croatian patients or their prognostic values. Therefore, we investigated the expression pattern of SATB1 and p16 in paraffin-embedded lymph node biopsies using standard immunohistochemistry. We found that 21% of the patients stained positive for SATB1, while 15% of the patients displayed positive staining for p16. Furthermore, we aimed to understand the prognostic value of each protein through the analysis of the overall survival (OS) and progression-free survival (PFS). SATB1 showed a significantly positive correlation with better OS and PFS, while p16 expression had no impact. Interestingly, when patients were stratified by a combination of the two studied markers, we found that patients in the SATB1+/p16- group tended to have the best prognosis in HL, according to statistical significance. In conclusion, SATB1 and p16 might be potentially useful as diagnostic and prognostic markers for HL. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate treatment outcomes in adolescents who underwent laparoscopic surgery with an ultrasonic scalpel for symptomatic varicocele compared with adolescents who underwent surgery with a polymer clip. Methods: A total of 270 adolescents with a median age of 16 (interquartile range, IQR 13–17) years were included in the study. Taking into account the laparoscopic varicocelectomy technique used, the patients were divided into two groups. In the first group (n = 151), a polymer clip was used, while in the second group (n = 119), an ultrasonic scalpel was used to resect the spermatic vessels. The primary outcome measure was the effect of the laparoscopic technique used on treatment outcomes (postoperative complications and recurrence rates). Secondary outcomes were the duration of surgery and anesthesia and the length of hospital stay. Results: The duration of the surgical procedure (12 min (IQR 11, 15) versus 15 min (12, 19), p = 0.029) and anesthesia (21.5 min (16, 29.5) versus 28 min (23, 34), p = 0.003) was shorter in the group of adolescents in whom laparoscopic varicocelectomy was performed with an ultrasonic scalpel than in the group in which a polymer clip was used. No statistically significant difference was found between the groups studied in terms of length of hospital stay, recurrence rate (p >0.999), and complications (p = 0.703). There were no cases of testicular atrophy in either group. In the group of patients who underwent laparoscopic varicocelectomy with an ultrasonic scalpel, a slightly higher incidence of hydroceles was found (n = 4, 3.4%) than in the group in which a polymer clip was used (n = 2, 1.3%) (p = 0.410). At six-month follow-up, it was found that the majority of patients showed moderate or significant improvement in the spermogram after laparoscopic varicocelectomy (n = 85, 89.5%). In addition, the subjective discomfort or pain disappeared in the majority of patients (n = 71, 93.4%). The testicular volume increased significantly in 132 adolescents (89.8%). Conclusions: Laparoscopic varicocelectomy with a polymer clip or ultrasonic scalpel is safe and effective in adolescents with symptomatic varicocele. Treatment outcomes after laparoscopic varicocelectomy are the same regardless of whether a polymer clip or an ultrasonic scalpel is used to resect the spermatic vessels. The use of an ultrasonic scalpel for resection of the spermatic vessels shortens the overall duration of surgery and anesthesia. [ABSTRACT FROM AUTHOR]

Background and Objectives: Colorectal cancer (CRC) is the most frequently diagnosed malignant disease of the gastrointestinal system, and new diagnostic and prognostic markers are needed to elucidate the complete tumor profile. Materials and Methods: We used CRC tumor tissues (Dukes' A-D) and adjacent noncancerous tissues of 43 patients. Immunohistochemistry was used to examine the expression of phosphodiesterase 4B (PDE4B), phosphodiesterase 4D (PDE4D), and secreted frizzled related protein 5 (SFRP5) markers. We also analyzed the expression levels of PDE4B, PDE4D, and SFRP5 in CRC tissues compared to control tissues using RNA-sequencing data from the UCSC Xena browser. Results: In CRC stages, the distribution of PDE4B-positive cells varied, with differing percentages between epithelium and lamina propria. Statistically significant differences were found in the number of PDE4B-positive epithelial cells between healthy controls and all CRC stages, as well as between different CRC stages. Similarly, significant differences were observed in the number of PDE4B-positive cells in the lamina propria between healthy controls and all CRC stages, as well as between different CRC stages. CRC stage Dukes' C exhibited a significantly higher number of PDE4B-positive cells in the lamina propria compared to CRC stage Dukes' B. Significant differences were noted in the number of PDE4D-positive epithelial cells between healthy controls and CRC stages Dukes' A, B, and D, as well as between CRC stage Dukes' C and stages A, B, and D. CRC stage Dukes' A had significantly more PDE4D-positive cells in the lamina propria compared to stage D. Significant differences were also observed in the number of SFRP5-positive cells in the lamina propria between healthy controls and all CRC stages, as well as between CRC stages Dukes' A and D. While the expression of PDE4D varied across CRC stages, the expression of SFRP5 remained consistently strong in both epithelium and lamina propria, with significant differences noted mainly in the lamina propria. The expression levels of PDE4B, PDE4D, and SFRP5 reveal significant differences in the expression of these genes between CRC patients and healthy controls, with notable implications for patient prognosis. Namely, our results demonstrate that PDE4B, PDE4D, and SFRP5 are significantly under-expressed in CRC tissues compared to control tissues. The Kaplan–Meier survival analysis and the log-rank (Mantel–Cox) test revealed distinct prognostic implications where patients with lower expression levels of SFRP5 exhibited significantly longer overall survival. The data align with our immunohistochemical results and might suggest a potential tumor-suppressive role for these genes in CRC. Conclusions: Considering significantly lower gene expression, aligned with our immunohistochemical data in tumor tissue in comparison to the control tissue, as well as the significantly poorer survival rate in the case of its higher expression, we can hypothesize that SFRP5 is the most promising biomarker for CRC out of the observed proteins. These findings suggest alterations in PDE4B, PDE4D, and SFRP5 expression during CRC progression, as well as between different stages of CRC, with potential implications for understanding the molecular mechanisms involved in CRC development and progression. [ABSTRACT FROM AUTHOR]

Kidney failures in infants are mostly caused by congenital anomalies of the kidney and urinary tract (CAKUT), which are among the most common congenital birth disorders worldwide when paired with cardiac abnormalities. People with CAKUT often have severe kidney failure as a result of a wide range of abnormalities that can occur alone or in conjunction with other syndromic disorders. In this study, we aimed to investigate the expression pattern of CAKUT candidate genes alpha-8 integrin (ITGA8) and Van Gogh-like 2 (VANGL2) in fetal tissues of healthy and CAKUT-affected kidneys using immunohistochemistry and immunofluorescence. We found that under CAKUT circumstances, the expressions of ITGA8 and VANGL2 are changed. Additionally, we showed that VANGL2 expression is constant during fetal aging, but ITGA8 expression varies. Moreover, compared to normal healthy kidneys (CTRL), ITGA8 is poorly expressed in duplex kidneys (DKs) and dysplastic kidneys (DYS), whereas VANGL2 is substantially expressed in dysplastic kidneys (DYS) and poorly expressed in hypoplastic kidneys (HYP). These results point to VANGL2 and ITGA8 as potential prognostic indicators for CAKUT malformations. Further research is necessary to explore the molecular mechanisms underlying this differential expression of ITGA8 and VANGL2. [ABSTRACT FROM AUTHOR]

Our study examines the immunoexpression patterns of Megalin, Cubilin, Caveolin-1, Gipc1 and Dab2IP in the embryonic development (E) and postnatal (P) mouse kidney, with a focus on differentiating patterns between wild-type (wt) and yotari, Dab1−/− (yot) mice. Immunofluorescence revealed raised immunoexpression of receptors Megalin and Cubilin at the ampulla/collecting ducts and convoluted tubules across all developmental stages, with the most prominent immunoexpression observed in the convoluted tubules and the parietal epithelium of the Bowman's capsule. Quantitative analysis showed a higher percentage of Megalin and Cubilin in wt compared to yot mice at E13.5. Co-expression of Megalin and Cubilin was observed at the apical membrane of convoluted tubules and the parietal layer of the Bowman's capsule. The staining intensity of Megalin varied across developmental stages, with the strongest reactivity observed at the ampulla and collecting ducts at embryonic day (E) 13.5 in wt mice. In contrast, Caveolin-1 exhibited high immunoexpression in the metanephric mesenchyme, blood vessels, and the border area between the metanephric mesenchyme and renal vesicle, with a decrease in immunoexpression as development progressed. Gipc1 showed diffuse cytoplasmic staining in metanephric mesenchyme, convoluted tubules and collecting ducts, with significant differences in immunoexpression between wild-type and yot mice at both investigated embryonic time points. Dab2IP immunofluorescent staining was most prominent in renal vesicle/glomeruli and ampulla/collecting ducts at E13.5, with mild staining intensity observed in the distal convoluted tubules postnatally. Our findings elucidate distinct immunoexpression of patterns and potential parts of these proteins in the development and function of the kidney, highlighting the importance of further investigation into their regulatory mechanisms. [ABSTRACT FROM AUTHOR]

Approximately half of the cases of chronic kidney disease (CKD) in childhood are caused by congenital anomalies of the kidney and urinary tract (CAKUT). Specific genes were identified as having significant importance in regard to the underlying genetic factors responsible for the CAKUT phenotype, and in our research, we focused on analyzing and comparing the expression levels of ectodysplasin A2 receptor (EDA2R), protocadherin9 (PCDH9), and TNF receptor-associated factor 7 (TRAF7) proteins in the cortex and medulla of healthy control kidneys during developmental phases 2, 3, and 4. We also performed an analysis of the area percentages of the mentioned proteins in the cortical and medullary sections of healthy embryonic and fetal kidneys compared to those affected by CAKUT, including duplex kidneys (DK), horseshoe kidneys (HK), hypoplastic kidneys (HYP), and dysplastic kidneys (DYS). We found that the CAKUT candidate gene proteins EDA2R, PCDH9, and TRAF7 are all expressed during normal human kidney development stages. In DYS, the expression of EDA2R was higher than in normal kidneys, likely due to EDA2R's role in apoptosis, which was upregulated in specific cases and could possibly contribute to the formation of DYS. The expression of PCDH9 was lower in HK, which can be attributed to the possible role of PCDH9 in cell migration suppression. Decreased PCDH9 expression is linked to increased cell migration, potentially contributing to the development of HK. The level of TRAF7 expression was reduced in all examined kidney disorders compared to normal kidneys, suggesting that this reduction might be attributed to the crucial role of TRAF7 in the formation of endothelium and ciliogenesis, both of which are essential for normal kidney development. Further research is required to ascertain the function of these proteins in both the typical development of the kidney and in CAKUT. [ABSTRACT FROM AUTHOR]

The estimation of distances and angles is a routine part of an orthopedic surgical procedure. However, despite their prevalence, these steps are most often performed manually, heavily relying on the surgeon's skill and experience. To address these issues, this study presents a sensor-equipped drill system which enables automatic estimation of the drilling angle and channel length. The angular accuracy and precision of the system were tested over a range of inclination angles and proved to be superior to the manual approach, with mean absolute errors ranging from 1.9 to 4.5 degrees for the manual approach, and from 0.6 to 1.3 degrees with the guided approach. When sensors were used for simultaneous estimation of both the inclination and anteversion angles, the obtained mean absolute errors were 0.35 ± 0.25 and 2 ± 1.33 degrees for the inclination and anteversion angles, respectively. Regarding channel length estimation, using measurements obtained with a Vernier caliper as a reference, the mean absolute error was 0.33 mm and the standard deviation of errors was 0.41 mm. The obtained results indicate a high potential of smart drill systems for improvement of accuracy and precision in orthopedic surgical procedures, enabling better patient clinical outcomes. [ABSTRACT FROM AUTHOR]

Vesicoureteral reflux (VUR) is defined as the urine backflow from the urinary bladder to the pyelo-caliceal system. In contrast, intrarenal reflux (IRR) is the backflow of urine from the renal calyces into the tubulointerstitial space. VURs, particularly those associated with IRR can result in reflux nephropathy when accompanied by urinary tract infection (UTI). The prevalence of IRR in patients with diagnosed VUR is 1–11% when using voiding cystourethrography (VCUG), while 11.9–61% when applying the contrast-enhanced voiding urosonography (ceVUS). The presence of IRR diagnosed by VCUG often correlates with parenchymal scars, when diagnosed by a 99mTc dimercaptosuccinic acid scan (DMSA scan), mostly in kidneys with high-grade VURs, and when diagnosed by ceVUS, it correlates with the wide spectrum of parenchymal changes on DMSA scan. The study performed by both ceVUS and DMSA scans showed IRRs associated with non-dilated VURs in 21% of all detected VURs. A significant difference regarding the existence of parenchymal damage was disclosed between the IRR-associated and IRR-non-associated VURs. A higher portion of parenchymal changes existed in the IRR-associated VURs, regardless of the VUR grade. That means that kidneys with IRR-associated VURs represent the high-risk group of VURs, which must be considered in the future classification of VURs. When using ceVUS, 62% of places where IRR was found were still unaffected by parenchymal changes. That was the basis for our recommendation of preventive use of long-term antibiotic prophylaxis until the IRR disappearance, regardless of the VUR grade. We propose a new classification of VURs using the ceVUS method, in which each VUR grade is subdivided based on the presence of an IRR. [ABSTRACT FROM AUTHOR]