Directional control of angiogenesis to produce a designed multiscale micro-vascular network with bioprinting

Department of Biomedical EngineeringThe biomimetic vascular network is a key element in regeneration of viable, functional and scalable artificial tissues. In this study, we developed a multiscale vascular network that can be patterned freely by using bioprinting technology. An endothelialized channel of several hundred micrometer scale was directly printed. The micro-vascular network consisting of tubular structures of several tens of micrometers was generated through the direction control of angiogenic sprouting using the chemotaxis effect. For this purpose, human umbilical vein endothelial cells (HUVEC) and angiogenic factor secreting cells, normal human dermal fibroblasts (NHDF), were co-patterned at 1 to 2 mm intervals using water soluble bio-ink and alginate based bio-ink, respectively. Then, a bridge pattern connecting the two patterned gels was made with fibrin gel. After printing, an endothelialized channel of about 800 ??m was formed by selective removal of water soluble bio-ink. The angiogenic sprouting was induced at about 200 ??m/day along the bridge pattern from the channel. It was also possible to fabricate a multiscale micro-vascular network with diagonal, wave and branch shapes using bridge patterns of various designs. In this study, we investigated the functionality of hepatocytes by co-culturing mouse primary hepatocytes after fabricating a vascular construct with hepatic lobule-shaped pattern to confirm the utility of the constructed process. As a result, we could confirm largely improved albumin and urea secretion. Based on these results, we confirmed that the tissue specific multiscale vascular network could be constructed. This technique should provide a useful tool for the development of functional and scalable vascularized tissues.clos

Shaping the Emerging Norms of Using Large Language Models in Social Computing Research

The emergence of Large Language Models (LLMs) has brought both excitement and concerns to social computing research. On the one hand, LLMs offer unprecedented capabilities in analyzing vast amounts of textual data and generating human-like responses, enabling researchers to delve into complex social phenomena. On the other hand, concerns are emerging regarding the validity, privacy, and ethics of the research when LLMs are involved. This SIG aims at offering an open space for social computing researchers who are interested in understanding the impacts of LLMs to discuss their current practices, perspectives, challenges when engaging with LLMs in their everyday work and collectively shaping the emerging norms of using LLMs in social computing research

Robot-Assisted Radical Prostatectomy:Modified Ultradissection Reduces pT2 Positive Surgical Margins on the Bladder Neck

The purpose of this study was to compare the positive surgical margin (PSM) rates of 2 techniques of robot-assisted radical prostatectomy (RARP) for pT2 (localized) prostate cancer. A retrospective analysis was conducted of 361 RARP cases, performed from May 2005 to September 2008 by a single surgeon (KHR) at our institution (Yonsei University College of Medicine). In the conventional technique, the bladder neck was transected first. In the modified ultradissection, the lateral border of the bladder neck was dissected and then the bladder neck was transected while the detrusor muscle of the bladder was well visualized. Perioperative characteristics and outcomes and PSM rates were analyzed retrospectively for pT2 patients (n＝217), focusing on a comparison of those undergoing conventional (n＝113) and modified ultradissection (n＝104) techniques. There was no difference between the conventional and modified ultradissection group in mean age, BMI, PSA, prostate volume, biopsy Gleason score, and DʼAmico prognostic criteria distributions. The mean operative time was shorter (p＜0.001) and the estimated blood loss was less (p＜0.01) in the modified ultradissection group. The PSM rate for the bladder neck was significantly reduced by modified ultradissection, from 6.2% to 0% (p＜0.05). In conclusion, modified ultradissection reduces the PSM rate for the bladder neck

Bucillamine prevents cisplatin-induced ototoxicity through induction of glutathione and antioxidant genes.

Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH

CT Evidence for Subchondral Trabecular Injury of the Femoral Head in Transient Osteoporosis of the Hip: A Case Report

A 28-yr-old woman presented with both hip pain that started sequentially during the peripartum period. Diagnosis of transient osteoporosis of the hip (TOH) was made based on typical findings of plain radiographs and magnetic resonance images. The subchondral trabeculae of the femoral head were evaluated on serially taken coronal multiplanar reformation computerized tomogram images. At 4 weeks after pain onset, marked decrease in the sclerotic density with irregular discontinuation was observed in the primary compression trabeculae. At 12 weeks, a focal area of irregular thickening of trabeculae was observed. At 20 weeks, sclerotic density of trabeculae recovered markedly and the focal area of irregular trabecular thickening disappeared. At 1 yr, subchondral trabeculae recovered almost completely. The evidence of subchondral trabecular injury was observed in the femoral heads of TOH

Yonsei Experience in Robotic Urologic Surgery - Application in Various Urological Procedures

PURPOSE: The da Vinci robot system has been used to perform complex reconstructive procedures in a minimally invasive fashion. Robot-assisted laparoscopic radical prostatectomy has recently established as one of the standard cares. Based on experience with the robotic prostatectomy, its use is naturally expanding into other urologic surgeries. We examine our practical pattern and application of da Vinci robot system in urologic field. PATIENTS AND METHODS: Robotic urologic surgery has been performed during a period from July 2005 to August 2008 in a total of 708 cases. Surgery was performed by 7 operators. In our series, radical prostatectomy was performed in 623 cases, partial nephrectomy in 43 cases, radical cystectomy in 11 cases, nephroureterectomy in 18 cases and other surgeries in 15 cases. RESULTS: In the first year, robotic urologic surgery was performed in 43 cases. However, in the second year, it was performed in 164 cases, and it was performed in 407 cases in the third year. In the first year, only prostatectomy was performed. In the second year, partial nephrectomy (2 cases), nephroureterectomy (3 cases) and cystectomy (1 case) were performed. In the third year, other urologic surgeries than prostatectomy were performed in 64 cases. The first robotic surgery was performed with long operative time. For instance, the operative time of prostatectomy, partial nephrectomy, cystectomy and nephroureterectomy was 418, 222, 340 and 320 minutes, respectively. Overall, the mean operative time of prostatectomy, partial nephrectomy, cystectomy and nephrourectectomy was 179, 173, 309, and 206 minutes, respectively. CONCLUSION: Based on our experience at a single-institution, robot system can be used both safely and efficiently in many areas of urologic surgeries including prostatectomy. Once this system is familiar to surgeons, it will be used in a wide range of urologic surgeryope