Two germ granule eIF4E isoforms reside in different mRNPs to hand off C elegans mRNAs from translational repression to activation.

We studied the function of translation factor eIF4E isoforms in regulating mRNAs in germ cell granules/condensates. Translational control of mRNAs plays an essential role in germ cell gene regulation. Messenger ribonucleoprotein (mRNP) complexes assemble on mRNAs as they move from the nucleus into perinuclear germ granules to exert both positive and negative post-transcriptional regulation in the cytoplasm. In C. elegans , germ granules are surprisingly dynamic mRNP condensates that remodel during development. Two eIF4E isoforms (called IFE-1 and IFE-3), eIF4E-Interacting Proteins (4EIPs), RBPs, DEAD-box helicases, polyadenylated mRNAs, Argonautes and miRNAs all occupy positions in germ granules. Affinity purification of IFE-1 and IFE-3 allowed mass spectrometry and mRNA-Seq to identify the proteins and mRNAs that populate stable eIF4E mRNPs. We find translationally controlled mRNAs (e.g. pos-1, mex-3, spn-4, etc.) enriched in IFE-3 mRNPs, but excluded from IFE-1 mRNPs. These mRNAs also require IFE-1 for efficient translation. The findings support a model in which oocytes and embryos utilize the two eIF4Es for opposite purposes on critically regulated germline mRNAs. Careful colocalization of the eIF4Es with other germ granule components suggests an architecture in which GLH-1, PGL-1 and the IFEs are stratified to facilitate sequential interactions for mRNAs. Biochemical characterization demonstrates opposing yet cooperative roles for IFE-3 and IFE-1 to hand-off of translationally controlled mRNAs from the repressed to the activated state, respectively. The model involves eIF4E mRNPs shuttling mRNAs through nuclear pore-associated granules/condensates to cytoplasmic ribosomes.

Use of budget savings from patent expiration of cancer drugs to improve affordability and accessibility.

BACKGROUND: The introduction of generics after the loss of patent exclusivity plays a major role in budget savings by significantly decreasing drug prices. The aims of this study were to estimate the budget savings from off-patent cancer drugs in 2020-2024 and to inform decision makers on how these savings could be used to improve the affordability of innovative cancer treatments in South Korea. METHODS: A model was developed to calculate budget savings from off-patent cancer drug use in Korea over 5 years (2020-2024). Cancer drugs with one or more valid patents that expire between 2020 and 2024 in Korea were selected. Key input parameters in the model included market share of generics, market growth, and prices of originators and generics. To reflect market dynamics after patent expiration, the trends of the off-patent market were estimated using historical sales volume data of IQVIA from 2012 to 2018. The study assumed that the prices of off-patent drugs decreased according to the price regulations set by the Korean government and that the off-patent market sales volume did not grow. Sensitivity analyses were performed to investigate the uncertainty in model input parameters. RESULTS: A total of 24 cancer drugs which met selection criteria were identified. In the base case analysis, patent expiration of cancer drugs between 2020 and 2024 could lead to a spending reduction of ₩234,429 million ($203 million), which was 20% of the cancer drug expenditure in the 5-year period. The savings ranged from ₩157,633 million ($136 million) to ₩434,523 million ($376 million) depending on the scenarios in sensitivity analyses. CONCLUSIONS: The findings indicate that patent loss of cancer drugs could lead to a 20% reduction in spending on cancer drugs over the next 5 years in South Korea. The savings could be used to improve the affordability of innovative, advanced cancer drugs for 94,000 cancer patients by reallocating the budget savings from patent expiration.

The associations between insomnia and health-related quality of life in rehabilitation units at 1month after stroke.

OBJECTIVE: The principal objective of this study was to investigate the relationship between insomnia and health-related quality of life (HRQoL) during the early stage of stroke rehabilitation. METHODS: The subjects were 214 first-time stroke patients admitted to a rehabilitation unit at one of three Korean hospitals. Within 7days after stroke, functions were evaluated using; the Berg Balance Scale, the Modified Barthel Index, the Mini Mental State Examination, the Frontal Assessment Battery, Screening Tests for Aphasia and Neurologic-Communication Disorders, and the National Institute of Health Stroke Scale. Insomnia, depression, anxiety, and HRQoL were investigated at one month after stroke. Insomnia was defined as presence of at least one of the four following; difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, and non-restorative sleep. HRQoL was assessed using the Short Form Health survey SF-8. Depression and anxiety were measured using the Hospital Anxiety Depression Scale. Multivariate linear regression analysis was conducted to examine the association between insomnia and HRQoL. RESULTS: The prevalence of insomnia at one month after stroke was 59.5%. Patients with insomnia were more likely to be older and female and to have depression and anxiety. Patients with insomnia had poorer physical and mental HRQoL. By multivariate analyses, physical HRQoL was significantly associated with type of stroke, hypnotic usage, balancing function, and insomnia. Mental HRQoL was significantly associated with balancing function, depression, and insomnia. CONCLUSION: Insomnia was found to be negatively associated with physical and mental HRQoL in stroke patients during the early stage of rehabilitation.

The Effect of Sleep Disturbances on the Functional Recovery of Rehabilitation Inpatients Following Mild and Moderate Stroke.

OBJECTIVE: The aim of the study was to explore the impact of insomnia and sleep disturbance on the functional outcomes of mild and moderated stroke. DESIGN: A multicenter-observational and correlation study was performed. Two hundred eighty patients with mild-moderate severity stroke admitted to three acute hospitals rehabilitation departments. Diagnostic Statistical Manual of Mental Disorders, Fourth Edition, criteria were used to define patients with insomnia and any sleep disturbance. Patient's initial and final functions were evaluated using the Korean version of the Berg Balance Scale, the Korean version of Modified Barthel Index, the Korean version of Mini-Mental State Examination, the Korean version of the Frontal Assessment Battery, and the Korean version of National Institute of Health Stroke Scale. Sleep disturbance and function were assessed with respect to stroke severity as defined by the Korean version of National Institute of Health Stroke Scale. RESULTS: The prevalence of Diagnostic Statistical Manual of Mental Disorders, Fourth Edition insomnia and any sleep disturbance were 26.9% and 56.7%, respectively. After adjusting for age, sex, depression, anxiety, length of stay, and hypnotic usage, the improvement of Korean version of the Berg Balance Scale was significantly lower in the any sleep disturbance group. In the moderate stroke group, the Korean version of the Berg Balance Scale improvement was significantly lower in the any sleep disturbance group, whereas in the mild stroke group, the Korean version of the Berg Balance Scale improvement was not significant. CONCLUSIONS: Sleep disturbance after stroke was found to have negative effects on functional recovery, especially balance improvement in moderate stroke group.

Space maintenance in autogenous fresh demineralized tooth blocks with platelet-rich plasma for maxillary sinus bone formation: a prospective study.

This prospective study evaluated the effectiveness of autogenous fresh demineralized tooth block (Auto-FDT block) with platelet-rich plasma (PRP) for maxillary sinus augmentation with simultaneous implant installation. Auto-FDT block with PRP was used in Group 1 (n = 15) and combined graft (allograft and xenograft) powder with PRP was used in Group 2 (n = 15). For up to 2 years after the final prosthesis was installed, clinical and radiographic examinations were performed to evaluate the amount of graft materials, residual alveolar height (RAH), sinus height (SH) after grafting, augmented graft height (AGH) and resorption height (RH). In ten cases, biopsies were harvested for histological and histomorphometric analyses. A total of 59 implants were placed in a severe atrophic posterior maxilla with less than 5 mm of RAH and sinus augmentation. None of the patients developed sinusitis or other complications, such as implant loss. The graft material extracted included one molar (or 2 premolars) in Group 1 and 1.8 cc in Group 2. The radiologic examination revealed the following average between-group difference SH (Group 1, 14.12 ± 1.63 mm vs Group 2, 16.51 ± 1.29 mm) and AGH (Group 1, 11.62 ± 2.22 mm vs Group 2, 13.65 ± 1.35 mm). However, sufficient SH and AGH were observed for the implants in the Auto-FDT block group. Two years after final prosthesis was installed, no between-group difference in the RH was observed (Group 1, 1.23 ± 0.73 mm vs Group 2, 1.77 ± 0.54 mm, P = 0.021). The histomorphometric analysis revealed no between-group difference in the new bone volume (Group 1, 23.13 ± 1.42 % vs Group 2, 24.18 ± 2.19 %, P = 0.548). The results showed that Auto-FDT block with PRP can be used in grafted sinuses for implants with only one extracted molar (or two premolars). Auto-FDT block with PRP promotes new bone formation that is comparable with combined grafts. Auto-FDT block with PRP is as an alternative to bone grafting and can be a predictable procedure for sinus augmentation.

Cudrania tricuspidata Stem Extract Induces Apoptosis via the Extrinsic Pathway in SiHa Cervical Cancer Cells.

The focus of this study is the anti-cancer effects of Cudrania tricuspidata stem (CTS) extract on cervical cancer cells. The effect of CTS on cell viability was investigated in HPV-positive cervical cancer cells and HaCaT human normal keratinocytes. CTS showed significant dose-dependent cytotoxic effects in cervical cancer cells. However, there was no cytotoxic effect of CTS on HaCaT keratinocytes at concentrations of 0.125-0.5 mg/mL. Based on this cytotoxic effect, we demonstrated that CTS induced apoptosis by down-regulating the E6 and E7 viral oncogenes. Apoptosis was detected by DAPI staining, annexin V-FITC/PI staining, cell cycle analysis, western blotting, RT-PCR, and JC-1 staining in SiHa cervical cancer cells. The mRNA expression levels of extrinsic pathway molecules such as Fas, death receptor 5 (DR5), and TNF-related apoptosis-inducing ligand (TRAIL) were increased by CTS. Furthermore, CTS treatment activated caspase-3/caspase-8 and cleavage of poly (ADP-ribose) polymerase (PARP). However, the mitochondrial membrane potential and expression levels of intrinsic pathway molecules such as Bcl-2, Bcl-xL, Bax, and cytochrome C were not modulated by CTS. Taken together, these results indicate that CTS induced apoptosis by activating the extrinsic pathway, but not the intrinsic pathway, in SiHa cervical cancer cells. These results suggest that CTS can be used as a modulating agent in cervical cancer.

Various autogenous fresh demineralized tooth forms for alveolar socket preservation in anterior tooth extraction sites: a series of 4 cases.

The aim of this study was to evaluate the clinical relevance of autogenous fresh demineralized tooth (Auto-FDT) prepared at chairside immediately after extraction for socket preservation. Teeth were processed to graft materials in block, chip, or powder types immediately after extraction. Extraction sockets were filled with these materials and dental implants were installed immediately or after a delay. A panoramic radiograph and a conebeam CT were taken. In two cases, tissue samples were taken for histologic examination. Vertical and horizontal maintenance of alveolar sockets showed some variance depending on the Auto-FDT and barrier membrane types used. Radiographs showed good bony healing. Histologic sections showed that it guided good new bone formation and resorption pattern of the Auto-FDT. This case series shows that Auto-FDT prepared at chairside could be a good material for the preservation of extraction sockets. This study will suggest the possibility of recycling autogenous tooth after immediate extraction.

Demineralized deciduous tooth as a source of bone graft material: its biological and physicochemical characteristics.

OBJECTIVE: To examine structural and physicochemical characteristics of demineralized deciduous tooth powder (DDTP) in relation to demineralization time and to present potential of using DDTP as a bone graft material. STUDY DESIGN: For structural and physicochemical analysis, scanning electron microscopy, inductively coupled plasma spectrometry, energy-dispersive X-ray analysis, X-ray diffraction analysis, differential scanning calorimetry, and Brunauer-Emmett-Teller surface area analysis were performed. In in vivo experiments, DDTP was grafted in 20 Sprague-Dawley rats' calvarial defects, and radiographic and histologic examination and histomorphometric analysis were performed. RESULTS: In vitro studies confirmed physicochemical demands for collagen-based bone graft material, such as lowered calcium content, lowered crystallinity of hydroxyapatite, and exposed organic structures to demineralization. In vivo experiment indicated new bone formation in DDTP-grafted sites and gradual resorption of the grafted particles. Defect closure rate was significantly higher in the 8-week DDTP-grafted group compared with control (P < .05). CONCLUSIONS: Deciduous teeth had structural and physicochemical characteristics suitable for grafting with appropriate demineralization. Bone healing was observed to have successfully occurred in DDTP-grafted sites.

An alternative treatment option for a bony defect from large odontoma using recycled demineralization at chairside.

Odontoma is the most common odontogenic benign tumor, and the treatment of choice is generally surgical removal. After excision, bone grafts may be necessary depending on the need for further treatment, or the size and location of the odontoma. Although the osteogenic capacity of a demineralized tooth was verified as early as 1967 by Urist and many other investigators, the cumbersome procedure, including a long demineralization time, may be less than comfortable for clinicians. A modified ultrasonic technology, with periodic negative pressure and temperature control, facilitated rapid and aseptic preparation of demineralized teeth for bone grafts. This approach reduces the demineralization time dramatically (≤80 minutes), so that the graft material can be prepared chairside on the same day as the extraction. The purpose of this article is to describe two cases of large compound odonotomas used as graft material prepared chairside for enucleation-induced bony defects. These two clinical cases showed favorable wound healing without complications, and good bony support for future dental implants or orthodontic treatment. Finally, this report will suggest the possibility of recycling the benign pathologic hard tissue as an alternative treatment option for conventional bone grafts in clinics.

Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy Studies on Processed Tooth Graft Material by Vacuum-ultrasonic Acceleration.

PURPOSE: The current gold standard for clinical jawbone formation involves autogenous bone as a graft material. In addition, demineralized dentin can be an effective graft material. Although demineralized dentin readily induces heterotopic bone formation, conventional decalcification takes three to five days, so, immediate bone grafting after extraction is impossible. This study evaluated the effect of vacuum ultrasonic power on the demineralization and processing of autogenous tooth material and documented the clinical results of rapidly processed autogenous demineralized dentin (ADD) in an alveolar defects patient. METHODS: The method involves the demineralization of extracted teeth with detached soft tissues and pulp in 0.6 N HCl for 90 minutes using a heat controlled vacuum-ultrasonic accelerator. The characteristics of processed teeth were evaluated by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Bone grafting using ADD was performed for narrow ridges augmentation in the mandibular area. RESULTS: The new processing method was completed within two hours regardless of form (powder or block). EDS and SEM uniformly demineralized autotooth biomaterial. After six months, bone remodeling was observed in augmented sites and histological examination showed that ADD particles were well united with new bone. No unusual complications were encountered. CONCLUSION: This study demonstrates the possibility of preparing autogenous tooth graft materials within two hours, allowing immediate one-day grafting after extraction.

Vertical Augmentation of Maxillary Posterior Alveolar Ridge Using Allogenic Block Bone Graft and Simultaneous Maxillary Sinus Graft.

The maxillary posterior area is the most challenging site for the dental implant. Although the sinus graft is a predictable and successful technique for rehabilitation of atrophic and pneumatized posterior maxilla, when there is severe destruction of alveolar bone, a very long crown length remains challenging after successful dental implants installation with sinus graft. We performed vertical augmentation of the maxillary posterior alveolar ridge using the allogenic block bone graft with a simultaneous sinus graft using allogenic and heterogenic bone chips. After about six months, we installed the dental implant. After this procedure, we achieved a more favorable crown-implant fixture ratio and better results clinically and biomechanically. This is a preliminary report of vertical augmentation of maxillary posterior alveolar ridge using allogenic block bone graft and simultaneous maxillary sinus graft. Further research requires longer observation and more patients.

Modulating the rigidity and mineralization of collagen gels using poly(lactic-co-glycolic acid) microparticles.

Extensive efforts have been made to prepare osteoconductive collagen gels for the regeneration of normal bone and the pathological examination of diseased bone; however, collagen gels are often plagued by limited controllability of their rigidity and mineral deposition. This study reports a simple but efficient strategy that tunes the mechanical properties of, and apatite formation in, collagen gels by incorporating hydrolyzable poly(lactic-co-glycolic acid) (PLGA) microparticles within the gels. The PLGA microparticles are associated with the collagen fibrils and increased both the gel's elasticity and rigidity while minimally influencing its permeability. As compared with pure collagen gels, the PLGA microparticle-filled collagen gels, termed PLGA-Col hydrogels, significantly enhanced the deposition of apatite-like minerals within the gels when incubated in simulated body fluid or encapsulated with mesenchymal stem cells (MSCs) undergoing osteogenic differentiation. Finally, PLGA-Col hydrogels mineralized by differentiated MSCs led to an enhanced formation of bone-like tissues within the hydrogels. Overall, the PLGA-Col hydrogel system developed in this study will serve to improve the quality of osteoconductive matrices for both fundamental and clinical studies that are relevant to bone repair, regeneration, and pathogenesis.

Reamer-mediated transalveolar sinus floor elevation without osteotome and simultaneous implant placement in the maxillary molar area: clinical outcomes of 391 implants in 380 patients.

OBJECTIVES: Minimally invasive sinus elevation and augmentation using a transalveolar approach can reduce perioperative complications and patient discomfort. A specially designed reamer accomplishes this without the use of an osteotome or a mallet. The objective of this study is to present this technique with relevant clinical cases and patient outcomes. MATERIAL AND METHODS: Series of reamers with one cutting and one reaming edge were used to prepare an osteotomy site for posterior maxillary areas. A total of 391 osteotomies were prepared with the reamer in 380 patients, and 373 implants were placed simultaneously. In addition to the procedure's success parameters, levels of intraoperative patient comfort were monitored using a visual analogue scale. RESULTS: The mean height of the residual alveolar process was 5.8 (0.9) mm, whereas mean elevation of the sinus floor was 6.2 (0.4) mm. Eighteen (4.6%) Schneiderian membrane perforations occurred, and the 2-year survival rate was 95.4%. The success rate was 92.7% in sites with thin sinus floors (< 4 mm) and 96.4% in sites with greater bone height (> 4 mm). None of the patients experienced any discomfort during the procedure. CONCLUSIONS: Within the limits of the present study, it can be concluded that reamer-mediated transalveolar sinus floor elevation is a reliable method for implant placement in the posterior maxilla, even at sites with ≤ 4 mm of residual alveolar bone height. This reamer-mediated procedure is less invasive than traditional osteotomy and can minimize patient discomfort during sinus floor elevation.

Platelet-rich fibrin is a Bioscaffold and reservoir of growth factors for tissue regeneration.

The platelet-rich fibrin (PRF) is known as a rich source of autologous cytokines and growth factors and universally used for tissue regeneration in current clinical medicine. However, the microstructure of PRF has not been fully investigated nor have been studied the key molecules that differ PRF from platelet-rich plasma. We fabricated PRF under Choukroun's protocol and produced its extract (PRFe) by freezing at -80°C. The conventional histological, immunohistological staining, and scanning electron microscopy images showed the microstructure of PRF, appearing as two zones, the zone of platelets and the zone of fibrin, which resembled a mesh containing blood cells. The PRFe increased proliferation, migration, and promoted differentiation of the human alveolar bone marrow stem cells (hABMSCs) at 0.5% concentration in vitro. From the results of proteome array, matrix metalloproteinase 9 (MMP9) and Serpin E1 were detected especially in PRFe but not in concentrated platelet-rich plasma. Simultaneous elevation of MMP9, CD44, and transforming growth factor ß-1 receptor was shown at 0.5% PRFe treatment to the hABMSC in immunoblot. Mineralization assay showed that MMP9 directly regulated mineralization differentiation of hABMSC. Transplantation of the fresh PRF into the mouse calvarias enhanced regeneration of the critical-sized defect. Our results strongly support the new characteristics of PRF as a bioscaffold and reservoir of growth factors for tissue regeneration.

Proteomic analysis of differentially expressed proteins in bovine endometrium with endometritis.

Endometritis is one of the primary reasons for reproductive failure. In order to investigate endometritis-associated marker proteins, proteomic analysis was performed on bovine endometrium with endometritis. In bovine endometritis, desmin, α-actin-2, heat-shock protein (HSP) 27, peroxiredoxin-6, luteinizing hormone receptor isoform 1, collectin-43 precursor, deoxyribonuclease-I (DNase-I), and MHC class I heavy chain (MHC-Ih) were up-regulated. In contrast, transferrin, interleukin-2 precursor, hemoglobin ß subunit, and potassium channel tetramerisation domain-containing 11 (KCTD11) were down-regulated in comparison to normal endometrium. The proteomic results were validated by semiquantitative-PCR and immunoblot analysis. The mRNA levels of desmin, transferrin, α-actin-2, HSP27, KCTD11, and MHC-Ih were up-regulated by over 1.5-fold, and showed a pattern similar to their proteomic profiles. Desmin and α-actin-2 protein showed positive correlations between proteomic analysis and immunoblot analysis. These results suggest that desmin and α-actin-2 may play important roles in endometritis-related function, and could be useful markers for the diagnosis of bovine endometritis.

Immediate loading as a vehicle for interdisciplinary training in implant placement and restoration.

Recently, implant surgery has been introduced into postdoctoral prosthodontic programs; however, efficient training models to teach this have not been described to date. For training models to be effective and acceptable to all parties, a mutually beneficial situation must be created, and guidelines that can be followed easily need to be described. The purpose of this report is to suggest immediate loading of dental implants as an example for an interdisciplinary training model that integrates both the surgical aspects of implant therapy into the education of prosthodontic graduate students and the prosthodontic aspects of implant therapy into the training of periodontal graduate students. A flow chart of training steps is described for a patient treated with an immediately loaded mandibular fixed full-arch prosthesis on five interforaminal implants. Both the prosthodontic and the periodontal residents were involved in all phases of treatment. These postdoctoral students were in the final year of their program. Therefore, individual treatment steps could be taught interchangeably and accomplished by the student of the other specialty under the supervision of a clinical instructor. The unique characteristic of the immediate loading procedure, which includes surgical implant placement as well as immediate conversion of an existing denture into a fixed implant-supported provisional prosthesis, allows each postgraduate student to experience detailed surgical and prosthodontic treatment in a controlled environment on the day of surgery.

Dedifferentiated liposarcoma of the retroperitoneum.

A dedifferentiated liposarcoma of the retroperitoneum is an extremely rare tumor. A 51-year old man was admitted to our department because a retroperitoneal mass was seen on abdominal computed tomography at another hospital. Computed tomography of the abdomen and magnetic resonance imaging showed a large pelvic mass located in the right hemipelvis, and it was pushing the right ureter and invading the right kidney, duodenum, colon and inferior vena cava. The patient underwent right radical nephrectomy, pylorus preserving pancreatoduodenectomy, right hemicolectomy and artificial blood vessel replacement for the inferior vena cava. The histopathological diagnosis was dedifferentiated liposarcoma and the patient was free from recurrence on the computed tomography that was done 6 months after the operation.

Healing of rabbit calvarial bone defects using biphasic calcium phosphate ceramics made of submicron-sized grains with a hierarchical pore structure.

OBJECTIVES: This study investigated the efficacy of new bone graft substitutes - biphasic calcium phosphates (BCP) made of submicron-sized grains with fully interconnected wide-range micron-scale pores in two different macrodesigns: donut shaped with a 300-400 microm central macropore (n-BCP-1) or rod-shaped (n-BCP-2)--in the healing of rabbit calvarial defects, and compared their bone-healing properties with those of various commercial bone substitutes, which included substitutes with similar BCP composition (MBCP and Osteon), anorganic bovine bone (Bio-Oss), and beta-TCP (Cerasorb). MATERIAL AND METHODS: The surface morphology of the bone substitutes was investigated using scanning electron microscopy (SEM). Defects 8 mm in diameter were created in the calvaria of 30 adult male New Zealand White rabbits and were filled with six types of bone substitutes. The percentage of newly formed bone (NB%) was evaluated histomorphometrically 4 and 8 weeks after implantation. RESULTS: SEM observation showed submicron-sized grains with fully interconnected micropore structures in the n-BCP-1 and n-BCP-2 groups; these groups also showed considerable new bone formation in inner micropores as well as on the outer surfaces. The n-BCP-1 group exhibited enhanced new bone formation and direct ingrowth of bone tissue with blood vessels into central pores. Histomorphometric analysis showed significantly greater NB% in the n-BCP-1 group when compared with the other groups at 4 and 8 weeks (P<0.05). CONCLUSION: A new BCP ceramics made of submicron-sized grains with a hierarchical pore structure was an effective osteoconductive material for the treatment of osseous defects of rabbit calvaria.

Material-based deployment enhances efficacy of endothelial progenitor cells.

Cell-based therapies are attractive for revascularizing and regenerating tissues and organs, but clinical trials of endothelial progenitor cell transplantation have not resulted in consistent benefit. We propose a different approach in which a material delivery system is used to create a depot of vascular progenitor cells in vivo that exit over time to repopulate the damaged tissue and participate in regeneration of a vascular network. Microenvironmental conditions sufficient to maintain the viability and outward migration of outgrowth endothelial cells (OECs) have been delineated, and a material incorporating these signals improved engraftment of transplanted cells in ischemic murine hindlimb musculature, and increased blood vessel densities from 260 to 670 vessels per mm(2), compared with direct cell injection. Further, material deployment dramatically improved the efficacy of these cells in salvaging ischemic murine limbs, whereas bolus OEC delivery was ineffective in preventing toe necrosis and foot loss. Finally, material deployment of a combination of OECs with another cell population commonly isolated from peripheral or cord blood, endothelial progenitor cells (EPCs) returned perfusion to normal levels in 40 days, and prevented toe and foot necrosis. Direct injection of an EPC/OEC combination was minimally effective in improving limb perfusion, and untreated limbs underwent autoamputation in 3 days. These results demonstrate that vascular progenitor cell utility is highly dependent on the mode of delivery, and suggest that one can create new vascular beds for a variety of applications with this material-controlled deployment of cells.

Isolation and characterization of postnatal stem cells from human dental tissues.

It was reported that postnatal stem cells are present in adult tissues such as bone marrow, liver, muscle, dental pulp, and periodontal ligament. We isolated postnatal stem cells from human dental tissues such as dental pulp (DPSC), periodontal ligament (PDLSC), periapical follicle (PAFSC), and the surrounding mandibular bone marrow (MBMSC) to ascertain their properties. Immunocytochemistry proved the existence of stem cells in these cell populations using STRO-1 as a stem cell marker. These cells also expressed the mesenchymal stem cell (MSC) markers CD29 and CD44. The isolated cells showed self-renewal capabilities and colony-forming efficiency. Almost all of the dental stem cells showed optimal growth when they were cultured in alpha modification of Eagle's medium (alpha-MEM) supplemented with 10% fetal calf serum (FCS) and 100 microM ascorbic acid. Only the PAFSC showed increased proliferation in 20% FCS and 50 microM ascorbic acid. All of the dental stem cells were capable of differentiating into adipocytes and mineral nodule forming cells. MBMSC, in particular, showed much better mineralization compared to the others. These results indicate that MSCs exist in various tissues of the teeth and can differentiate into osteoblasts, adipocytes, and other kinds of cells with varying efficiency.