Atypical post-infectious glomerulonephritis with c-ANCA positivity followed by endocarditis.

Post-infectious glomerulonephritis (PIGN), an uncommon variety of glomerulonephritis (GN), is characterized by emergence of nephritic syndrome within a few weeks following an infectious event. PIGN typically presents as a mild condition and tends to resolve by the time of diagnosis for GN. Aggregatibacter actinomycetemcomitans belongs to the HACEK group of bacteria, which constitutes less than 3% of bacteria responsible for community-acquired infective endocarditis. We present a case of 29-year-old man suspected of lymphoma with B-symptoms along with severe splenomegaly and nephromegaly. Shortly after, he developed an episode of nephritic syndrome accompanied by acute kidney injury (AKI) and high titers of cytoplasmic ANCA (c-ANCA)-positivity. Kidney biopsy revealed PIGN with tubulointerstitial nephritis. Despite treatment with antibiotics and corticosteroid, he visited the emergency room due to worsening dyspnea and multi-organ failure. An echocardiogram showed a bicuspid aortic valve with vegetation unseen on previous echocardiogram. He underwent aortic valve replacement immediately without adverse events. Four months after valve replacement, his renal function and cardiac performance have remained stable. We report a case of PIGN with AKI and high titers of c-ANCA appearing later as an infective endocarditis due to Aggregatibacter actinomycetemcomitans. With careful clinical observation and appropriate and timely management, satisfactory outcomes for patient health are possible.

Implication of cystic fluid cytology of renal cell carcinoma on surgical practice.

OBJECTIVES: To evaluate the incidence of positive cystic fluid cytology and its risk factors in cystic renal cell carcinoma (RCC) addressing its implication on the current surgical practice. METHODS: All clinically diagnosed Bosniak III, IV cystic renal masses from March 2019 to August 2022 were studied prospectively. Database of patients' demographics and cystic tumor characteristics were recorded. Partial or radical nephrectomies were performed by either laparoscopic or robotic approach. Cystic fluid was collected right after specimen retrieval in the surgical field and examined by pathologist. Cytology results were compared to the demographic, perioperative variables using univariate and multivariate analysis. RESULTS: A total of 70 patients of histologically confirmed cystic RCC were included. Sixty seven patients underwent radical nephrectomy with laparoscopic or robotic approaches, while 3 patients underwent radical nephrectomy. There was no intraoperative cystic rupture or fluid spillage. Positive cystic fluid cytology findings were identified in 34 (48.6%) patients, while negative cystic fluid cytology were identified in 36 (51.4%) cases. Definite malignant cells were observed in 28 patients while the other six patients showed highly suspicious atypical cells. Histologically, 24 (70.8%) patients were proven clear cell RCC and 25 (73%) showed Fuhrman grade 1 or 2 in final histologic review in positive group. Univariate and multivariate regression analysis between positive and negative cytology groups showed that the presence of the malignant cells in cystic fluid was significantly associated with patients' age (> 55 years) and Bosniak grade of cystic tumor (p < 0.05). CONCLUSIONS: Definite malignant cells in cystic fluid cytology were observed through our study. Additionally, patients' age (> 55 years) and Bosniak grade were the significant risk factors of positive cytology in cystic RCC. Therefore, necessity of meticulous manipulation of cystic renal tumors, despite their clinical features, should not be underemphasized to avoid the least possible tumor cell seeding in case of cystic rupture when operating such high risk of positive cytology.

Three-Dimensional Bio-Printed Scaffold Sleeves With Mesenchymal Stem Cells for Enhancement of Tendon-to-Bone Healing in Anterior Cruciate Ligament Reconstruction Using Soft-Tissue Tendon Graft.

PURPOSE: To investigate the efficacy of the insertion of 3-dimensional (3D) bio-printed scaffold sleeves seeded with mesenchymal stem cells (MSCs) to enhance osteointegration between the tendon and tunnel bone in anterior cruciate ligament (ACL) reconstruction in a rabbit model. METHODS: Scaffold sleeves were fabricated by 3D bio-printing. Before ACL reconstruction, MSCs were seeded into the scaffold sleeves. ACL reconstruction with hamstring tendon was performed on both legs of 15 adult rabbits (aged 12 weeks). We implanted 15 bone tunnels with scaffold sleeves with MSCs and implanted another 15 bone tunnels with scaffold sleeves without MSCs before passing the graft. The specimens were harvested at 4, 8, and 12 weeks. H&E staining, immunohistochemical staining of type II collagen, and micro-computed tomography of the tunnel cross-sectional area were evaluated. Histologic assessment was conducted with a histologic scoring system. RESULTS: In the histologic assessment, a smooth bone-to-tendon transition through broad fibrocartilage formation was identified in the treatment group, and the interface zone showed abundant type II collagen production on immunohistochemical staining. Bone-tendon healing histologic scores were significantly higher in the treatment group than in the control group at all time points. Micro-computed tomography at 12 weeks showed smaller tibial (control, 9.4 ± 0.9 mm2; treatment, 5.8 ± 2.9 mm2; P = .044) and femoral (control, 9.6 ± 2.9 mm2; treatment, 6.0 ± 1.0 mm2; P = .03) bone-tunnel areas in the treated group than in the control group. CONCLUSIONS: The 3D bio-printed scaffold sleeve with MSCs exhibited excellent results in osteointegration enhancement between the tendon and tunnel bone in ACL reconstruction in a rabbit model. CLINICAL RELEVANCE: If secure biological healing between the tendon graft and tunnel bone can be induced in the early postoperative period, earlier, more successful rehabilitation may be facilitated. Three-dimensional bio-printed scaffold sleeves with MSCs have the potential to accelerate bone-tendon healing in ACL reconstruction.

Acute kidney injury induced by thrombotic microangiopathy in a patient with hemophagocytic lymphohistiocytosis.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a fatal clinical syndrome characterized by excessive immune activation and inflammation. It is frequently complicated by acute kidney injury (AKI) that often develops as acute tubular necrosis (ATN). Meanwhile, renal thrombotic microangiopathy (TMA) is a rare pathologic finding that mostly occurs in hemolytic uremic syndrome or thrombotic thrombocytopenic purpura. There are only few reports on TMA developing in patients with HLH. We present here a rare case of TMA associated HLH. CASE PRESENTATION: A 60-year-old woman was admitted for a fever of unknown origin that had persisted for several weeks. She presented with AKI and pancytopenia. Clinical, laboratory and bone marrow biopsy findings met the criteria of HLH. Kidney biopsy showed TMA and minimal ATN, which suggested that the primary cause of AKI was TMA in this case. Because of sustained oliguria, we initiated hemodialysis (HD) and also decided to use chemotherapy composed of dexamethasone, etoposide and cyclosporine for treatment of HLH. Six months after the initiation of chemotherapy, pancytopenia was completely resolved, indicating the resolution of HLH. At the same time, serum creatinine decreased to a normal range without the need for HD, suggesting the resolution of TMA. CONCLUSION: We report a case of renal TMA associated HLH. This case suggests that renal TMA should be considered as a primary cause of AKI in patients with underlying HLH.

Asymptomatic hematuria associated with urinary polyomavirus infection in immunocompetent patients.

Unlike the case for immunodeficient patients, little is known about polyomavirus (PV) infection in immunocompetent patients. PV infection in immunocompetent individuals has been reported sporadically, but little is known about asymptomatic hematuria. To determine the clinical significance and prevalence of urinary PV infection in immunocompetent patients, a total of 95 individuals admitted to Seoul St. Mary's hospital were investigated. Sixty-four patients were enrolled for evaluation of asymptomatic hematuria, and 31 healthy individuals served as controls. Clinical screening for PV infection was performed by urine cytology analysis by liquid-based preparation and urine RT-PCR for BK virus (BKV) and JC virus (JCV), respectively. The average age of the patients in the PV(+) - and PV(-) -groups with asymptomatic hematuria were 60 years and 46 years, respectively. Urine cytology analysis revealed decoy cells in 37/64 hematuria patients (38.9%), but not in healthy controls. They were more prevalent in male patients. Eighty-two patients (86.3%) had PV viruria, viz., 54/64 patients in the hematuria group and 28/31 in the control group. Interestingly, 28/31 (90.3%) cases in the healthy control group were positive for PV viruria, which exceeded the number in the hematuria group (84.4%). PV viruria was associated primarily with JCV, rather than BKV. PV viruria, including JCV viruria, correlated with urine decoy cells and increased age. In conclusion, urinary PV infection is common in immunocompetent patients with asymptomatic hematuria and is age-related. These data may provide an insight into the pathogenesis and future treatment of asymptomatic hematuria associated with urinary PV infection in immunocompetent patients.

Sirolimus conversion efficacy for graft function improvement and histopathology in renal recipients with mild to moderate renal insufficiency.

This study was designed to evaluate whether sirolimus (SRL) conversion effectively improves renal function and histopathology in calcineurin inhibitor (CNI)-treated renal recipients with mild to moderate renal insufficiency. SRL conversion from CNI was performed in patients who underwent kidney transplantation from 6 months to 5 yr prior to screening. Forty-five patients were enrolled. The effect of SRL conversion on graft function was evaluated, and protocol biopsies were performed preconversion and 1 yr after conversion. Overall graft function after SRL conversion gradually improved, and the improvement in renal function was closely associated with the shorter duration of CNI exposure. When we divided the patients by the duration of CNI exposure, the patients with less than 1 yr of CNI exposure demonstrated significant improvement, but patients with a greater than 1 yr CNI exposure did not exhibit significant improvement. In contrast, protocol biopsies demonstrated no significant improvements in the modified "ah" score or other Banff scores after SRL conversion. Furthermore, the duration of CNI treatment prior to SRL conversion was not associated with histological findings 1 yr after SRL conversion. SRL conversion improved graft function in renal recipients with mild to moderate renal insufficiency, but this effect is not accompanied by histological improvement.

Plant-Based Decellularization: A Novel Approach for Perfusion-Compatible Tissue Engineering Structures.

This study explores the potential of plant-based decellularization in regenerative medicine, a pivotal development in tissue engineering focusing on scaffold development, modification, and vascularization. Plant decellularization involves removing cellular components from plant structures, offering an eco-friendly and cost-effective alternative to traditional scaffold materials. The use of plant-derived polymers is critical, presenting both benefits and challenges, notably in mechanical properties. Integration of plant vascular networks represents a significant bioengineering breakthrough, aligning with natural design principles. The paper provides an in-depth analysis of development protocols, scaffold fabrication considerations, and illustrative case studies showcasing plant-based decellularization applications. This technique is transformative, offering sustainable scaffold design solutions with readily available plant materials capable of forming perfusable structures. Ongoing research aims to refine protocols, assess long-term implications, and adapt the process for clinical use, indicating a path toward widespread adoption. Plant-based decellularization holds promise for regenerative medicine, bridging biological sciences with engineering through eco-friendly approaches. Future perspectives include protocol optimization, understanding long-term impacts, clinical scalability, addressing mechanical limitations, fostering collaboration, exploring new research areas, and enhancing education. Collectively, these efforts envision a regenerative future where nature and scientific innovation converge to create sustainable solutions, offering hope for generations to come.

Discovery and Validation of Survival-Specific Genes in Papillary Renal Cell Carcinoma Using a Customized Next-Generation Sequencing Gene Panel.

PURPOSE: Papillary renal cell carcinoma (PRCC), the second most common kidney cancer, is morphologically, genetically, and molecularly heterogeneous with diverse clinical manifestations. Genetic variations of PRCC and their association with survival are not yet well-understood. This study aimed to identify and validate survival-specific genes in PRCC and explore their clinical utility. MATERIALS AND METHODS: Using machine learning, 293 patients from the Cancer Genome Atlas-Kidney Renal Papillary Cell Carcinoma (TCGA-KIRP) database were analyzed to derive genes associated with survival. To validate these genes, DNAs were extracted from the tissues of 60 Korean PRCC patients. Next generation sequencing was conducted using a customized PRCC gene panel of 202 genes, including 171 survival-specific genes. Kaplan-Meier and Log-rank tests were used for survival analysis. Fisher's exact test was performed to assess the clinical utility of variant genes. RESULTS: A total of 40 survival-specific genes were identified in the TCGA-KIRP database through machine learning and statistical analysis. Of them, 10 (BAP1, BRAF, CFDP1, EGFR, ITM2B, JAK1, NODAL, PCSK2, SPATA13, and SYT5) were validated in the Korean-KIRP database. Among these survival gene signatures, three genes (BAP1, PCSK2, and SPATA13) showed survival specificity in both overall survival (OS) (p = 0.00004, p = 1.38 × 10-7, and p = 0.026, respectively) and disease-free survival (DFS) (p = 0.00002, p = 1.21 × 10-7, and p = 0.036, respectively). Notably, the PCSK2 mutation demonstrated survival specificity uniquely in both the TCGA-KIRP (OS: p = 0.010 and DFS: p = 0.301) and Korean-KIRP (OS: p = 1.38 × 10-7 and DFS: p = 1.21 × 10-7) databases. CONCLUSIONS: We discovered and verified genes specific for the survival of PRCC patients in the TCGA-KIRP and Korean-KIRP databases. The survival gene signature, including PCSK2 commonly obtained from the 40 gene signature of TCGA and the 10 gene signature of the Korean database, is expected to provide insight into predicting the survival of PRCC patients and developing new treatment.

Sex-specific survival gene mutations are discovered as clinical predictors of clear cell renal cell carcinoma.

Although sex differences have been reported in patients with clear cell renal cell carcinoma (ccRCC), biological sex has not received clinical attention and genetic differences between sexes are poorly understood. This study aims to identify sex-specific gene mutations and explore their clinical significance in ccRCC. We used data from The Cancer Genome Atlas-Kidney Renal Clear Cell Carcinoma (TCGA-KIRC), The Renal Cell Cancer-European Union (RECA-EU) and Korean-KIRC. A total of 68 sex-related genes were selected from TCGA-KIRC through machine learning, and 23 sex-specific genes were identified through verification using the three databases. Survival differences according to sex were identified in nine genes (ACSS3, ALG13, ASXL3, BAP1, JADE3, KDM5C, KDM6A, NCOR1P1, and ZNF449). Female-specific survival differences were found in BAP1 in overall survival (OS) (TCGA-KIRC, p = 0.004; RECA-EU, p = 0.002; and Korean-KIRC, p = 0.003) and disease-free survival (DFS) (TCGA-KIRC, p = 0.001 and Korean-KIRC, p = 0.000004), and NCOR1P1 in DFS (TCGA-KIRC, p = 0.046 and RECA-EU, p = 0.00003). Male-specific survival differences were found in ASXL3 (OS, p = 0.017 in TCGA-KIRC; and OS, p = 0.005 in RECA-EU) and KDM5C (OS, p = 0.009 in RECA-EU; and DFS, p = 0.016 in Korean-KIRC). These results suggest that biological sex may be an important predictor and sex-specific tailored treatment may improve patient care in ccRCC.

DHPLC is a highly sensitive and rapid screening method to detect BRAF(V600E) mutation in papillary thyroid carcinoma.

The BRAF(V600E) mutation has been reported to occur in 30% to 80% of papillary thyroid carcinomas (PTCs). Although direct sequencing is the method most commonly used to identify mutations, this technique is not sensitive enough to accurately detect low level mutation. To determine the optimal diagnostic method for detecting the BRAF(V600E) mutation in PTC, we compared the diagnostic efficacy of four representative detection methods in formalin-fixed paraffin-embedded thyroid tissues obtained from 40 patients diagnosed with PTC. To detect the BRAF(V600E) mutation, we amplified exon 15 of the BRAF gene and performed mutational analysis with direct sequencing, denaturing high-performance liquid chromatography (DHPLC), pyrosequencing and colorimetric assay. The BRAF mutation was detected in 33 cases (82.5%) by DHPLC, 23 cases (57.5%) by direct sequencing, 22 cases (55.0%) by pyrosequencing, and 37 cases (92.5%) by colorimetric assay. The sensitivity, negative predictive value and accuracy of DHPLC were 100%. The specificity and positive predictive values for DHPLC, direct sequencing and pyrosequencing were 100%, and for colorimetric assay they were 14.3% and 83.8%, respectively. The kappa value for DHPLC was a perfect 1.0, which was superior to the other methods. In conclusion, DHPLC is a sensitive, specific and accurate method for detecting the BRAF(V600E) mutation, especially low level mutation, in PTC.

Type III membranoproliferative glomerulonephritis in a patient with primary Sjögren's syndrome.

Renal involvement in the form of glomerulonephritis in Sjögren's syndrome (SS) is less common and usually a latent sequel in the course of the disease. We report a patient with Type III membarnoproliferative glomerulonephritis (MPGN) with hypothyroidism, which precedes the onset of the clinical manifestation of SS. She received immunosuppressions consisting of i.v. cyclophosphamide and high-dose corticosteroid and subsequently oral corticosteroid resulting in complete remission of nephrotic syndrome. To our knowledge, this is the first report of successfully treated Type III MPGN associated with SS.

Immunostaining of p16(INK4a)/Ki-67 and L1 capsid protein on liquid-based cytology specimens obtained from ASC-H and LSIL-H cases.

BACKGROUND: Atypical squamous cell cannot exclude high-grade squamous intraepithelial lesion (ASC-H) and low-grade intraepithelial lesion cannot exclude high-grade squamous intraepithelial lesion (LSIL-H) are ambiguous diagnostic entities for the prediction of high-grade cervical lesion. Objective and reproducible tests for predicting high-grade cervical lesions are needed to reduce unnecessary colposcopic referrals or follow-ups. OBJECTIVE: We aimed to identify an adequate set of adjunctive markers to predict cervical intraepithelial neoplasia grade 2+ (CIN2+) in residual liquid-based cytology specimens (LBCS). METHODS: We conducted p16 (INK4a)/Ki-67 and L1 capsid protein immunostaining and human papillomavirus (HPV) DNA typing on 56 LBCS diagnosed with ASC-H or LSIL-H, all of which were subjected to histologic confirmation or follow-up cytologic examination. RESULTS: Positivity for p16 (INK4a)/Ki-67 was associated with a histology of CIN2+ (P=0.047) and CIN3+ (P=0.002). Negativity for L1 capsid protein was associated with CIN2+ confirmed at follow-up (P=0.02).Positivity for high-risk HPV (HR-HPV) was associated with CIN2+ confirmed at follow-up (P=0.036) and a histology of CIN2+ (P=0.037). The sensitivity, specificity, positive predictive value, and negative predictive value for predicting follow-up CIN2+ were 76.2%, 51.4%, 48.5%, and 78.3%, respectively, for p16 (INK4a)/Ki-67 immunostaining; 95.2%, 34.3%, 46.5%, and 92.3%, respectively, for L1 capsid protein; and 66.7%, 67.7%, 54.5%, and 77.8%, respectively, for HR-HPV. The classification and regression tree analysis showed that the combined results of p16 (INK4a)/Ki-67 andL1 capsid protein immunostaining and the HR-HPV test, conducted sequentially, correctly classified 81.8% of samples (27/33)in the prediction of a histology of CIN2 + in ASC-H or LSIL-H. For determination of the histology of cervical intraepithelial neoplasia grade 3+ (CIN3+)in ASC-H or LSIL-H, we found that the combined results of p16 (INK4a)/Ki-67 and L1 capsid protein immunostaining correctly classified 78.8% (26/33) of samples. CONCLUSIONS: p16(INK4a)/Ki-67 and L1 capsid protein immunostaining and HR-HPV testing of residual LBCS diagnosed with ASC-H or LSIL-H are useful objective biomarkers for predicting CIN2+. Immunostaining for p16(INK4a)/Ki-67 and L1 capsid protein are sufficient to predict CIN3+.

Comparison of the Cobas 4800 HPV test and the Seeplex HPV4A ACE with the hybrid capture 2 test.

BACKGROUND: It is well-known that persistent cervical infections with high-risk human papillomavirus (HPV) are related to the development of high-grade cervical intraepithelial neoplasia and invasive cervical cancer and that infection with HPV 16 and HPV 18 accounts for approximately 70% of all cases of invasive cervical cancer. METHODS: We performed 3 HPV molecular tests-the Cobas 4800 HPV test, the Seeplex HPV4A ACE, and the hybrid capture 2 (HC2) test-in 146 cervical swab samples to compare between these three tests. RESULTS: There was a concordance rate of 82.8% between the results of the Cobas 4800 HPV and the HC2 test and a concordance rate of 84.9% between the results of the Seeplex HPV4A ACE and the HC2 test. Between the Cobas 4800 HPV test and the Seeplex HPV4A ACE, there was a concordance rate of 89.6% in the detection of high-risk HPV between the results and a concordance rate of 98.7% in the detection of HPV 16 or 18. When an abnormal Pap test was defined as ≥ low grade squamous intraepithelial lesion (LSIL), the sensitivity of the Cobas 4800 HPV test, the Seeplex HPV4A ACE and the HC2 test were 71.1%, 80.0%, and 88.9%, respectively, while their specificities were 76.4%, 74.5%, and 67.9%, respectively. CONCLUSIONS: The results of this study suggest that the Cobas 4800 HPV test and the Seeplex HPV4A ACE may be as effective as the HC2 test in detecting HR HPV and that the concordance between the results of the Cobas 4800 HPV test and the Seeplex HDV4A ACE may be higher in the detection of HPV 16 and HPV18 than concerning high-risk HPV.

142Development of an alginate-gelatin bioink enhancing osteogenic differentiation by gelatin release.

Hydrogels are natural bioink options for cellular printing due to their high-water content and permeable three-dimensional (3D) polymeric structure, which are favorable for cellular anchoring and metabolic activities. To increase the functionality of hydrogels as bioinks, biomimetic components are often incorporated, such as proteins, peptides, and growth factors. In this study, we aimed to enhance the osteogenic activity of a hydrogel formulation by integrating both the release and retention of gelatin so that gelatin serves as both an indirect support for released ink component on cells nearby and a direct support for encapsulated cells inside a printed hydrogel, thereby fulfills two functions. Methacrylate-modified alginate (MA-alginate) was chosen as the matrix because it has a low cell adhesion effect due to the absence of ligands. The gelatin-containing MA-alginate hydrogel was fabricated, and gelatin was found to remain in the hydrogel for up to 21 days. The gelatin remaining in the hydrogel had positive effects on encapsulated cells, especially on cell proliferation and osteogenic differentiation. The gelatin released from the hydrogel affected the external cells, showing more favorable osteogenic behavior than the control sample. It was also found that the MA-alginate/gelatin hydrogel could be used as a bioink for printing with high cell viability. Therefore, we anticipate that the alginate-based bioink developed in this study could potentially be used to induce osteogenesis in bone tissue regeneration.

Support-less ceramic 3D printing of bioceramic structures using a hydrogel bath.

Volumetric bone tissue defects are beyond the intrinsic regenerative capacity of bone tissue. With the recent development of ceramic 3D printing, various bioceramic scaffolds that can induce bone regeneration are being actively developed. However, hierarchical bone is complex, with overhanging structures that require additional sacrificial support during ceramic 3D printing. Not only can this increase the overall process time and material consumption, but breaks and cracks may occur when sacrificial supports are removed from fabricated ceramic structures. In this study, a support-less ceramic printing (SLCP) process using a hydrogel bath was developed to facilitate the manufacture of complex bone substitutes. A hydrogel bath, consisting of pluronic P123 with temperature-sensitive properties, mechanically supported the fabricated structure when the bioceramic ink was extruded into the bath and promoted the cement reaction to cure the bioceramic. SLCP enables the fabrication of complex bone constructs with overhanging structures, such as the mandible and maxillofacial bones, with reduced overall processing time and material consumption. Scaffolds fabricated by SLCP showed more cell adhesion, higher cell growth rate, and osteogenic protein expression due to their rougher surface than conventionally printed scaffolds. Hybrid scaffolds were fabricated by SLCP to co-print cells and bioceramics, and SLCP provided a cell-friendly environment, exhibiting high cell viability. SLCP enables control of the shape of various cells, bioactive substances, and bioceramics and thus can be used as an innovative 3D bioprinting technique to manufacture complex hierarchical bone structures.

Signal-Decay Based Approach for Visualization of Buried Defects in 3-D Printed Ceramic Components Imaged with Help of Optical Coherence Tomography.

We propose the use of Optical Coherence Tomography (OCT) as a tool for the quality control of 3-D-printed ceramics. Test samples with premeditated defects, namely single- and two-component samples of zirconia, titania, and titanium suboxides, were printed by stereolithography-based DLP (Digital Light Processing) processes. The OCT tomograms obtained on the green samples showed the capability of the method to visualize variations in the layered structure of the samples as well as the presence of cracks and inclusions at depths up to 130 µm, as validated by SEM images. The structural information was visible in cross-sectional images as well as in plan-view images. The optical signal measured from the printed zirconia oxide and titanium oxide samples showed strong attenuation with depth and could be fit with an exponential decay curve. The variations of the decay parameter correlated very well with the presence of defects and material variation. When used as an imaging quantity, the decay parameter projects the position of the defects into 2-D (X,Y) coordinates. This procedure can be used in real time, it reduces the data volume up to 1000 times, and allows for faster subsequent data analysis and transfer. Tomograms were also obtained on sintered samples. The results showed that the method can detect changes in the optical properties of the green ceramics caused by sintering. Specifically, the zirconium oxide samples became more transparent to the light used, whereas the titanium suboxide samples became entirely opaque. In addition, the optical response of the sintered zirconium oxide showed variations within the imaged volume, indicating material density variations. The results presented in this study show that OCT provides sufficient structural information on 3-D-printed ceramics and can be used as an in-line tool for quality control.

Fabrication of color-graded feldspathic dental prosthetics for aesthetic and restorative dentistry.

OBJECTIVE: Feasibility investigation of natural teeth shades replication on dental prosthetics fabricated via functionally graded additive manufacturing (FGAM) using combination of feldspathic porcelain (FP) and yttrium aluminum garnet cerium (Y3Al5O12:Ce, YAG:Ce) as a promising esthetic restoration option. METHODS: Color-graded feldspathic crown fabrication parameter through FGAM method was comprehensively examined from the slurry rheology, cure depth, debinding to sintering temperature. Effect of light absorbent also checked towards overcuring reaction during UV exposure by the shape comparison. Lastly, the flexural bending strength measured following ISO 6872:2015 to assure the applicability. Applying the studied parameter, natural teeth shades then imitated and investigated by alteration of FP and FP + 0.1 wt% YAG:Ce (Y-FP). Generated color across the structure captured through mobile camera, interpreted through the CIELAB coordinate and the gradation confirmed by the color differences (ΔE00) calculated using CIEDE2000 formula. RESULT: Parameter study indicated that 70 wt% of FP slurry with 3 wt% dispersant and 0.2 wt% light absorbent is favored. It produces excellent flowability in our FGAM system with less overcuring justified by edge margin reduction from 95.65° to 90.00° after UV exposure on rectangle shapes masking. The obtain structure also offers adequate flexural bending strength of 106.26 MPa (FP) and 101.36 MPa (Y-FP) after sintering at 780 °C. This validated the materials as class 2 dental prosthetics citing ISO 6872:2015. Color gradation was verified by the yellow b* value reduction (14.8 to -3.33) as it shifted from cervical to incisal area while ΔE00 further affirmed the differences from each segment in comparison with the FP and Y-FP. SIGNIFICANCE: Color gradation was successfully replicated by FP and YAG:Ce composition shift via FGAM technique. This result highlights the potential of FGAM as an alternative for fabricating dental prosthetics with high efficiency and improved esthetic appeal.

Enhancement of properties of a cell-laden GelMA hydrogel-based bioink via calcium phosphate phase transition.

To improve the properties of the hydrogel-based bioinks, a calcium phosphate phase transition was applied, and the products were examined. We successfully enhanced the mechanical properties of the hydrogels by adding small amounts (< 0.5 wt%) of alpha-tricalcium phosphate (α-TCP) to photo-crosslinkable gelatin methacrylate (GelMA). As a result of the hydrolyzing calcium phosphate phase transition involvingα-TCP, which proceeded for 36 h in the cell culture medium, calcium-deficient hydroxyapatite was produced. Approximately 18 times the compressive modulus was achieved for GelMA with 0.5 wt%α-TCP (20.96 kPa) compared with pure GelMA (1.18 kPa). Although cell proliferation decreased during the early stages of cultivation, both osteogenic differentiation and mineralization activities increased dramatically when the calcium phosphate phase transition was performed with 0.25 wt%α-TCP. The addition ofα-TCP improved the printability and fidelity of GelMA, as well as the structural stability and compressive modulus (approximately six times higher) after three weeks of culturing. Therefore, we anticipate that the application of calcium phosphate phase transition to hydrogels may have the potential for hard tissue regeneration.

The Oxford classification as a predictor of prognosis in patients with IgA nephropathy.

BACKGROUND: In 2009, the Oxford classification was developed as a pathological classification system for immunoglobulin A nephropathy (IgAN) to predict the risk of disease progression. The aim of this retrospective study was to evaluate the clinical and pathologic relevance of the Oxford classification in Korean patients with a pathologic diagnosis of IgAN. PATIENTS AND METHODS: We reviewed the renal pathology archives from January 2000 to December 2006 at Seoul St Mary's Hospital in Korea and identified 273 patients, who were diagnosed as having IgAN. We enrolled 197 patients who were available for further clinicopathologic analysis. All cases of IgAN were categorized according to the WHO classification, the semiquantitative classification and the Oxford classification. These pathologic classifications were compared. The clinical and laboratory findings at the time of biopsy were compared with those at the end of the follow-up according to the Oxford classification. RESULTS: When three pathologic classifications were compared, M1, S1, E1, T1 or T2 were associated with a higher score in the activity index. S1, T1 or T2 were associated with a higher score in the chronicity index and a higher grade in the WHO classification. The clinical and laboratory findings were compared according to the Oxford classification. At the time of biopsy, the proteinuria in patients with M1 was more than that of M0 (P = 0.035). At the end of follow-up, the number of antihypertensive drugs taken among patients with M1 was greater than that of patients with M0 (P = 0.001). At the time of biopsy, the proteinuria of patients with S1 was greater than that of S0 patients (P = 0.009). At the end of follow-up, the number of patients who received immunosuppressants was increased as the grade of T increased (P = 0.000). At the end point of the follow-up, the estimated glomerular filtration rate (eGFR) decreased as the grade of T increased (P = 0.008). The time-average proteinuria after adjusting the initial proteinuria increased significantly with increasing degree of T (P = 0.000). Levels of tubular atrophy/interstitial fibrosis were predictive for survival from end-stage renal disease or of having a 50% reduction of eGFR. CONCLUSION: The pathologic variables of the Oxford classification correlated significantly with other classifications (the WHO classification and the semiquantitative classification). The Oxford classification is a simple method for predicting renal outcome and differentiating between active and chronic lesions. We suggest that the Oxford classification offers an advantage for determining treatment policy for patients with IgAN.