• Title/Summary/Keyword: regeneration failure

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Canine Renal Failure Caused by Ochratoxin A and Citrinin in the Commercial Dog Food (시판 사료에 오염된 Ochratoxin A와 Citrinin에 의한 개의 신부전)

  • Ahn, So-Jeo;Jeoung, Seok-Young;Lim, Man-Su;Park, Son-Il;Han, Jeong-Hee;Kim, Doo
    • Journal of Veterinary Clinics
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    • v.24 no.2
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    • pp.82-87
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    • 2007
  • Five dogs with renal failure were referred to the Veterinary Medical Teaching Hospital at Kangwon National University. These dogs had the common history of consumption of Pedigree dry dog food produced in Thailand plant for over 1 month. The dogs showed anorexia, emaciation, vomiting, and polydipsia/polyuria. And in one severely affected dog, bloody diarrhea and hypothermia were seen. The remarkable clinicopathological signs were high value of BUN and creatinine. In some dogs, GGT, phosphorus and lipase were increased. However, no significant changes of complete blood count were found. In urinalysis, hematuria, low specific gravity urine, proteinuria, and calcium oxalate-like crystals were observed. Two severely affected dogs were died. The remained dogs were recovered gradually after change of dog food and supportive therapy. Pathological findings were seen typically in kidneys. Renal atrophy, congestion of the glomerular capillary, and diffuse degeneration, necrosis, dystrophic calcification and regeneration in the tubular epithelium were seen. Yellowish brown fluorolucent laminated materials or particles were quite often found in the lumina of the necrotizing renal tubules of cortex and medulla. Proliferation of fibrous tissue in the interstitium was also seen. By the mycotoxin analysis of the Pedigree dry dog food, ochratoxin A (OTA) and citrinin were detected as much as the concentration of 372.8 ppb and 8.3 ppb, respectively. The final diagnosis of renal failure caused by OTA and citrinin toxicosis was made on the basis of history takings, clinical signs, clinicopathological and pathological findings, and analysis of mycotoxins.

Resin bonding of metal brackets to glazed zirconia with a porcelain primer

  • Lee, Jung-Hwan;Lee, Milim;Kim, Kyoung-Nam;Hwang, Chung-Ju
    • The korean journal of orthodontics
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    • v.45 no.6
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    • pp.299-307
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    • 2015
  • Objective: The aims of this study were to compare the shear bond strength between orthodontic metal brackets and glazed zirconia using different types of primer before applying resin cement and to determine which primer was more effective. Methods: Zirconia blocks were milled and embedded in acrylic resin and randomly assigned to one of four groups: nonglazed zirconia with sandblasting and zirconia primer (NZ); glazed zirconia with sandblasting, etching, and zirconia primer (GZ); glazed zirconia with sandblasting, etching, and porcelain primer (GP); and glazed zirconia with sandblasting, etching, zirconia primer, and porcelain primer (GZP). A stainless steel metal bracket was bonded to each target surface with resin cement, and all specimens underwent thermal cycling. The shear bond strength of the specimens was measured by a universal testing machine. A scanning electron microscope, three-dimensional optical surface-profiler, and stereoscopic microscope were used to image the zirconia surfaces. The data were analyzed with one-way analyses of variance and the Fisher exact test. Results: Group GZ showed significantly lower shear bond strength than did the other groups. No statistically significant differences were found among groups NZ, GP, and GZP. All specimens in group GZ showed adhesive failure between the zirconia and resin cement. In groups NZ and GP, bonding failed at the interface between the resin cement and bracket base or showed complex adhesive and cohesive failure. Conclusions: Porcelain primer is the more appropriate choice for bonding a metal bracket to the surface of a full-contour glazed zirconia crown with resin cement.

PSME4 determines mesenchymal stem cell fate towards cardiac commitment through YAP1 degradation

  • Mira Kim;Yong Sook Kim;Youngkeun Ahn;Gwang Hyeon Eom;Somy Yoon
    • The Korean Journal of Physiology and Pharmacology
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    • v.27 no.4
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    • pp.407-416
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    • 2023
  • The regeneration of myocardium following acute circulatory events remains a challenge, despite numerous efforts. Mesenchymal stem cells (MSCs) present a promising cell therapy option, but their differentiation into cardiomyocytes is a time-consuming process. Although it has been demonstrated that PSME4 degrades acetyl-YAP1, the role of PSME4 in the cardiac commitment of MSCs has not been fully elucidated. Here we reported the novel role of PSME4 in MSCs cardiac commitment. It was found that overnight treatment with apicidin in primary-cultured mouse MSCs led to rapid cardiac commitment, while MSCs from PSME4 knock-out mice did not undergo this process. Cardiac commitment was also observed using lentivirus-mediated PSME4 knockdown in immortalized human MSCs. Immunofluorescence and Western blot experiments revealed that YAP1 persisted in the nucleus of PSME4 knockdown cells even after apicidin treatment. To investigate the importance of YAP1 removal, MSCs were treated with shYAP1 and apicidin simultaneously. This combined treatment resulted in rapid YAP1 elimination and accelerated cardiac commitment. However, overexpression of acetylation-resistant YAP1 in apicidin-treated MSCs impeded cardiac commitment. In addition to apicidin, the universal effect of histone deacetylase (HDAC) inhibition on cardiac commitment was confirmed using tubastatin A and HDAC6 siRNA. Collectively, this study demonstrates that PSME4 is crucial for promoting the cardiac commitment of MSCs. HDAC inhibition acetylates YAP1 and facilitates its translocation to the nucleus, where it is removed by PSME4, promoting cardiac commitment. The failure of YAP1 to translocate or be eliminated from the nucleus results in the MSCs' inability to undergo cardiac commitment.

EXPERIMENTAL STUDY ON THE HEALING PROCESSES AFTER MICROVASCULAR ANASTOMOSES;Light and Scanning electron microscopic observations (미세혈관 문합수술후 치유과정에 관한 실험적 연구)

  • Yoon, Jae-Hyun;Lee, Eun-Joo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.12 no.1
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    • pp.72-81
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    • 1990
  • Because failure of microvascular flap grafting has sometimes been attributed to vascular obstruction in the anastomotic site, this study investigated the healing process after microvascular anastomoses. The healing process of anastomotic sites were observed by the use of the light and the scanning electron microscope after microvascular anastomoses of the right common carotid artery in rats. The experimental animals were sacrificed on the 4th day, 1st, 2nd, 4th and 6th week. Throughout the whole experimental period, arterial patency rate was 78% (11/14). At the early stage, it was possible to recognize histologically disappearance of endothelial cell and rupture of part of the media. Subintimal hyperplasia and the growth of media appeared around the suture line at the 2nd week. Endothelial cell regeneration occurred and the depth of vessel wall was normalized at the 4th week. By the scanning electron microscope, at the early stage, the anastomotic site was covered with many platelets, red blood cells, fibrins and macrophages. At the 4th week, the insertion site of the thread was completely covered with normal endothelial cells which were parallel to longitudinal axis of vessels and complete reendothelialization over the anastomotic site seemed to take about 6th week.

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Shoot Regeneration from Leaf Explants of Digitalis purpurea L. (디기탈리스의 잎 절편으로부터 신초의 재분화)

  • Hwang, Sung-Jin;Lee, Hye-Jung;Hwang, Baik
    • Korean Journal of Medicinal Crop Science
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    • v.11 no.5
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    • pp.397-401
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    • 2003
  • Digitalis purpurea L. is a medicinal herb and have been used to congestive heart failure, mycocardial infarction, edema, angina etc. A protocol has been developed for in vitro propagation of adventitious shoot buds directly from leaf segments of D. purpurea Leaf explants of D. purpurea directly formed shoot buds when cultured on a MS medium supplemented with $2\;mg/l$ BA and $0.1\;mg/l$ IAA for 5 weeks. Adventitious shoots were multiplied by subculturing on the $B_5$ medium and shoot elongation was developed by subculturing on the WPM medium. Root formation from the shoot regenerated was achieved on MS basal medium containing 1 mg/ IBA.

Antimicrobial surfaces for craniofacial implants: state of the art

  • Actis, Lisa;Gaviria, Laura;Guda, Teja;Ong, Joo L.
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.39 no.2
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    • pp.43-54
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    • 2013
  • In an attempt to regain function and aesthetics in the craniofacial region, different biomaterials, including titanium, hydroxyapatite, biodegradable polymers and composites, have been widely used as a result of the loss of craniofacial bone. Although these materials presented favorable success rates, osseointegration and antibacterial properties are often hard to achieve. Although bone-implant interactions are highly dependent on the implant's surface characteristics, infections following traumatic craniofacial injuries are common. As such, poor osseointegration and infections are two of the many causes of implant failure. Further, as increasingly complex dental repairs are attempted, the likelihood of infection in these implants has also been on the rise. For these reasons, the treatment of craniofacial bone defects and dental repairs for long-term success remains a challenge. Various approaches to reduce the rate of infection and improve osseointegration have been investigated. Furthermore, recent and planned tissue engineering developments are aimed at improving the implants' physical and biological properties by improving their surfaces in order to develop craniofacial bone substitutes that will restore, maintain and improve tissue function. In this review, the commonly used biomaterials for craniofacial bone restoration and dental repair, as well as surface modification techniques, antibacterial surfaces and coatings are discussed.

AUTOTRANSPLANTATION OF TRANSPOSITIONED MAXILLARY CENTRAL INCISOR WITH MESIODENS AND IMPACTED MAXILLARY CANINE : A CASE REPORT (과잉치를 동반한 상악 중절치 전위와 상악 견치 매복에서 자가이식에 의한 치험례)

  • Nam, Dong-Woo;Kim, Hyun-Jung;Nam, Soon-Hyeun;Kim, Young-Jin
    • Journal of the korean academy of Pediatric Dentistry
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    • v.24 no.4
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    • pp.727-733
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    • 1997
  • Autotransplantation is a procedure which transplants teeth from the original position to other positions in the same individual. It is classified surgical reposition by intraalveolar autotransplantation and transalveolar autotransplantation. The prognosis for successful autotransplantation is dependent on a number of factors such as root development, surgical technique, patient's age, endodontic treatment, time and type of splinting, preservation of periodontal ligament and storage medium. The most important factor is preservation of periodontal ligament. The cause of the failure of transplantation include damage of the transplant during removal from deep palatal malposition, poor regeneration of the bone around the transplant and chronic periodontal infection. In case I, Impacted maxillary canine for which surgical exposure and orthodontic treatment was impossisle was transplanted. After 2 weeks, It showed periapical radiolucency and external root resorption. So, endodontic treatment was done. One year later, permanent filling was done with gutta percha. In case II, Transpositioned maxillary central incisor was transplanted after extraction of impacted mesiodens. Pulp vitality was maintained during 5 months without other clinical symptons.

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Clinical effectiveness of combining platelet rich fibrin with alloplastic bone substitute for the management of combined endodontic periodontal lesion

  • Goyal, Lata
    • Restorative Dentistry and Endodontics
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    • v.39 no.1
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    • pp.51-55
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    • 2014
  • The term "endo-perio" lesion has been proposed to describe the destructive lesion resulting from inflammatory products found in varying degrees in both the periodontium and the pulpal tissues. In most of the cases, clinical symptoms disappear following successful endodontic therapy. However failure after conventional root canal treatment calls for surgical intervention. A 35 year old male patient with endo-perio lesion in right maxillary lateral incisor was treated with platelet rich fibrin (PRF) and alloplastic bone substitute after conventional endodontic therapy. At the end of 6 months there was gain in clinical attachment, increased radiographic bone fill and reduction in probing depth which was maintained till 18 month follow-up. Present case report aims to evaluate the efficacy of PRF and alloplastic bone substitute in the management of intrabony defect associated with endo-perio lesion in maxillary lateral incisor because the healing potential of PRF and bone graft has not been widely studied in endodontics. The use of PRF allows the clinician to optimize tissue remodelling, wound healing and angiogenesis by the local delivery of growth factors and proteins. The novel technique described here enables the clinician to be benefited from the full regenerative capacity of this autologous biologic material.

Analysis of Welding Phenomena and Effect of Short Circuit Current Rise Slope in the High Speed $CO_2$ Welding of Steel Sheets ($CO_2$박판 고속용접에서 용접현상 분석과 전류상승기울기의 영향)

  • Kim, Young-Sam;Ryoo, Hoi-Soo;Kim, Hee-Jin
    • Journal of Welding and Joining
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    • v.23 no.5
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    • pp.14-19
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    • 2005
  • In high speed $CO_2$ welding, it has been blown to produce no sound bead with undercut or humping bead. In this study welding phenomena through synchronized high speed camera and output welding voltage and current waveform has been analyzed. For the purpose to improve a welding bead, effect of short circuit current rise slope has been examined. With commercial power source it was produced no sound bead by instantaneous short circuit, long arc period and stubbing at welding speed 2.5mm/min Humping bead or undercut were showed by instantaneous short circuit and long arc period. Also, the weld bead was not formed during the long short circuit period after stubbing start and long arc extinguishment period after wire sticking by failure of arc regeneration, because the droplet was not transferred to weld pool. With increasing short circuit current rise slope the frequency of stubbing was decreased and the normal short circuit rate was increased. A control of short circuit current rise slope was effective factor in high speed welding.

Are There Hopeful Therapeutic Strategies to Regenerate the Infarcted Hearts?

  • Gyu-Chul Oh;Yeon-Jik Choi;Bong-Woo Park;Kiwon Ban;Hun-Jun Park
    • Korean Circulation Journal
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    • v.53 no.6
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    • pp.367-386
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    • 2023
  • Ischemic heart disease remains the primary cause of morbidity and mortality worldwide. Despite significant advancements in pharmacological and revascularization techniques in the late 20th century, heart failure prevalence after myocardial infarction has gradually increased over the last 2 decades. After ischemic injury, pathological remodeling results in cardiomyocytes (CMs) loss and fibrosis, which leads to impaired heart function. Unfortunately, there are no clinical therapies to regenerate CMs to date, and the adult heart's limited turnover rate of CMs hinders its ability to self-regenerate. In this review, we present novel therapeutic strategies to regenerate injured myocardium, including (1) reconstruction of cardiac niche microenvironment, (2) recruitment of functional CMs by promoting their proliferation or differentiation, and (3) organizing 3-dimensional tissue construct beyond the CMs. Additionally, we highlight recent mechanistic insights that govern these strategies and identify current challenges in translating these approaches to human patients.