Tmem2 Deficiency Leads to Enamel Hypoplasia and Soft Enamel in Mouse.

Teeth consist of 3 mineralized tissues: enamel, dentin, and cementum. Tooth malformation, the most common craniofacial anomaly, arises from complex genetic and environmental factors affecting enamel structure, size, shape, and tooth eruption. Hyaluronic acid (HA), a primary extracellular matrix component, contributes to structural and physiological functions in periodontal tissue. Transmembrane protein 2 (TMEM2), a novel cell surface hyaluronidase, has been shown to play a critical role during embryogenesis. In this study, we demonstrate Tmem2 messenger RNA expression in inner enamel epithelium and presecretory, secretory, and mature ameloblasts. Tmem2 knock-in reporter mice reveal TMEM2 protein localization at the apical and basal ends of secretory ameloblasts. Micro-computed tomography analysis of epithelial-specific Tmem2 conditional knockout (Tmem2-CKO) mice shows a significant reduction in enamel layer thickness and severe enamel deficiency. Enamel matrix protein expression was remarkably downregulated in Tmem2-CKO mice. Scanning electron microscopy of enamel from Tmem2-CKO mice revealed an irregular enamel prism structure, while the microhardness and density of enamel were significantly reduced, indicating impaired ameloblast differentiation and enamel matrix mineralization. Histological evaluation indicated weak adhesion between cells and the basement membrane in Tmem2-CKO mice. The reduced and irregular expressions of vinculin and integrin ß1 suggest that Tmem2 deficiency attenuated focal adhesion formation. In addition, abnormal HA accumulation in the ameloblast layer and weak claudin 1 immunoreactivity in Tmem2-CKO mice indicate impaired tight junction gate function. Irregular actin filament assembly was also observed at the apical and basal ends of secretory ameloblasts. Last, we demonstrated that Tmem2-deficient mHAT9d mouse ameloblasts exhibit defective adhesion to HA-containing substrates in vitro. Collectively, our data highlight the importance of TMEM2 in adhesion to HA-rich extracellular matrix, cell-to-cell adhesion, ameloblast differentiation, and enamel matrix mineralization.

Role of Heparan Sulfate in Vasculogenesis of Dental Pulp Stem Cells.

Dental pulp stem cells (DPSCs) can differentiate into vascular endothelial cells and display sprouting ability. During this process, DPSC responses to the extracellular microenvironment and cell-extracellular matrix interactions are critical in regulating their ultimate cell fate. Heparan sulfate (HS) glycosaminoglycan, a major component of extracellular matrix, plays important roles in various biological cell activities by interacting with growth factors and relative receptors. However, the regulatory function of HS on vasculogenesis of mesenchymal stem cells remains unclear. The objective of this study was to investigate the role of HS in endothelial differentiation and vasculogenesis of DPSCs. Our results show that an HS antagonist suppressed the proliferation and sprouting ability of DPSCs undergoing endothelial differentiation. Furthermore, expression of proangiogenic markers significantly declined with increasing dosages of the HS antagonist; in contrast, expression of stemness marker increased. Silencing of exostosin 1 (EXT1), a crucial glycosyltransferase for HS biosynthesis, in DPSCs using a short hairpin RNA significantly altered their gene expression profile. In addition, EXT1-silenced DPSCs expressed lower levels of endothelial differentiation markers and displayed a reduced vascular formation capacity compared with control DPSCs transduced with scrambled sequences. The sprouting ability of EXT1-silenced DPSCs was rescued by the addition of exogenous HS in vitro. Next, we subcutaneously transplanted biodegradable scaffolds seeded with EXT1-silenced or control DPSCs into immunodeficient mice. Lumen-like structures positive for human CD31 and von Willebrand factor were formed by green fluorescent protein-transduced DPSCs. Numbers of blood-containing vessels were significantly lower in scaffolds loaded with EXT1-silenced DPSCs than specimens implanted with control DPSCs. Collectively, our findings unveil the crucial role of HS on endothelial differentiation and vasculogenesis of DPSCs, opening new perspectives for the application of HS to tissue engineering and dental pulp regeneration.

Impact of the lateral skeletal stability following bilateral sagittal split ramus osteotomy for mandibular asymmetry.

This study evaluated the stability of bilateral sagittal split ramus osteotomy (BSSRO) associated with positional plagiocephaly and temporal and masseter muscles using posteroanterior cephalogram analysis and three-dimensional computed tomography (3D-CT). This retrospective cohort study included 31 patients who underwent BSSRO for mandibular asymmetry. The cranial vault asymmetry index (CVAI) and the cephalic index were used as indicators of positional plagiocephaly. The distance from the vertical reference line to the menton (Me) was measured on posteroanterior cephalograms immediately and 1 year after surgery, and postoperative stability was assessed. Temporal and masseter muscles were constructed from 3D-CT data and their volumes were measured. Simple regression analysis showed a significant correlation between postoperative changes in the vertical reference line to the Me and the CVAI (R = 0.56, p = 0.001), the amount of surgical movement in the vertical reference line to the Me (R = 0.41, p = 0.023), and the variable temporal muscle volume (R = 0.27, p = 0.028). There was no significant correlation between postoperative changes in the vertical reference line to the Me and the cephalic index (R = 0.093, p = 0.62) and variable masseter muscle volume (R = 0.16, p = 0.38). According to multivariate analysis, CVAI (p = 0.003) and amount of surgical movement in the vertical reference line to the Me (p = 0.014) were significant predictors of postoperative change in the vertical reference line to the Me. Positional plagiocephaly and amount of surgical movement influence lateral skeletal stability following BSSRO for mandibular asymmetry.

Fabrication of Vascularized DPSC Constructs for Efficient Pulp Regeneration.

Dental pulp regeneration is a promising approach to restore the vitality of necrotic teeth. We have previously reported the fabrication of scaffold-free cell constructs containing only dental pulp stem cells (DPSCs) and their ability to form pulp-like tissue in the pulpless tooth. However, the DPSC construct could not build pulp-like tissue with a full root length because it is difficult to induce blood vessels from a small root canal foramen. Therefore, we hypothesized that vascular structure could be preformed in the DPSC construct by employing endothelial differentiation capability of DPSCs, and vascularized constructs might facilitate dental pulp regeneration in the pulpless tooth. In this study, vascularized DPSC constructs were fabricated by inducing endothelial differentiation, and then we investigated the behavior of differentiated DPSCs, the internal structure of cell constructs, and their pulp regenerative ability in vivo. We observed that DPSCs positive for CD31 and von Willebrand factor were localized at the outer layer of constructs and formed a reticulated lumen structure. The cells constituting the outer layer of the construct expressed endothelial differentiation markers at higher levels than cells in the inner part. These results indicated that DPSCs in the outer layer differentiated into endothelial cells and formed vascular-like structures in the cell construct. Next, a vascularized DPSC construct was transplanted into the human pulpless tooth that was implanted into immunodeficient mice in the subcutaneous space. After 6 wk of implantation, the vascularized construct formed pulp-like tissues with higher density of human CD31-positive blood vessels when compared with specimens implanted with a DPSC construct without prevascularization. These results suggest that the vascular structure formed in the DPSC construct facilitated the blood supply and enhanced pulp regeneration. This study demonstrates that a vascularized DPSC construct is a prospective biomaterial as an implant for novel dental pulp regeneration.

Gefitinib induction followed by chemoradiotherapy in EGFR-mutant, locally advanced non-small-cell lung cancer: LOGIK0902/OLCSG0905 phase II study.

BACKGROUND: The role of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) induction coupled with standard concurrent chemoradiotherapy (CRT) is unclear in unresectable, stage III, EGFR-mutant non-small-cell lung cancer (NSCLC). Therefore, a phase II trial was conducted to evaluate the efficacy and safety of gefitinib induction followed by CRT in this disease setting. PATIENTS AND METHODS: Patients with unresectable, EGFR-mutant, stage III NSCLC were administered gefitinib monotherapy (250 mg/day) for 8 weeks. Subsequently, patients without disease progression during induction therapy were administered cisplatin and docetaxel (40 mg/m2 each) on days 1, 8, 29, and 36 with concurrent radiotherapy at a total dose of 60 Gy. The primary endpoint was the 2-year overall survival (OS) rate, which was hypothesized to reach 85%, with a threshold of the lower limit of 60%. RESULTS: Twenty patients (median age: 66 years; male/female: 9/11; histology: 20 adenocarcinoma; stage IIIA/IIIB: 9/11; and exon 19/21: 10/10) were enrolled. The 2-year OS rate was 90% (90% confidence interval: 71.4% to 96.8%), indicating that this trial met the primary objective. The overall response rate and 1- and 2-year progression-free survival rates were 85.0%, 58.1%, and 36.9%, respectively. Grade ≥3 adverse events (>10%) included hepatic toxicity during the induction phase and neutropenia and febrile neutropenia in the CRT phase. Radiation pneumonitis grade ≥3 or treatment-related death did not occur. CONCLUSIONS: This is the first prospective study to demonstrate the favorable efficacy and safety of EGFR-TKI induction followed by standard CRT in EGFR-mutant, stage III NSCLC. Further confirmatory studies are needed.

The stress kinase mitogen-activated protein kinase kinase (MKK)7 is a negative regulator of antigen receptor and growth factor receptor-induced proliferation in hematopoietic cells.

The dual specificity kinases mitogen-activated protein kinase (MAPK) kinase (MKK)7 and MKK4 are the only molecules known to directly activate the stress kinases stress-activated protein kinases (SAPKs)/c-Jun N-terminal kinases (JNKs) in response to environmental or mitogenic stimuli. To examine the physiological role of MKK7 in hematopoietic cells, we used a gene targeting strategy to mutate MKK7 in murine T and B cells and non-lymphoid mast cells. Loss of MKK7 in thymocytes and mature B cells results in hyperproliferation in response to growth factor and antigen receptor stimulation and increased thymic cellularity. Mutation of mkk7 in mast cells resulted in hyperproliferation in response to the cytokines interleukin (IL)-3 and stem cell factor (SCF). SAPK/JNK activation was completely abolished in the absence of MKK7, even though expression of MKK4 was strongly upregulated in mkk7(-/-) mast cell lines, and phosphorylation of MKK4 occurred normally in response to multiple stress stimuli. Loss of MKK7 did not affect activation of extracellular signal-regulated kinase (ERK)1/2 or p38 MAPK. mkk7(-/-) mast cells display reduced expression of JunB and the cell cycle inhibitor p16INK4a and upregulation of cyclinD1. Reexpression of p16INK4a in mkk7(-/-) mast cells abrogates the hyperproliferative response. Apoptotic responses to a variety of stimuli were not affected. Thus, MKK7 is an essential and specific regulator of stress-induced SAPK/JNK activation in mast cells and MKK7 negatively regulates growth factor and antigen receptor-driven proliferation in hematopoietic cells. These results indicate that the MKK7-regulated stress signaling pathway can function as negative regulator of cell growth in multiple hematopoietic lineages.

In situ X-ray diffraction study on the growth kinetics of NiO nanoparticles.

The growth kinetics of NiO nanoparticles have been studied by in situ X-ray diffraction using two detection systems (conventional and imaging plate). NiO nanoparticles were formed by thermal decomposition after heating of an amorphous compound formed by the coprecipitation method. It was found that the detection method using an imaging plate is more efficient than the conventional detection mode for observing changes in the crystallite growth of nanocrystalline materials. Studies have been carried out to investigate the effects of the heating rates on the particles growth. The results suggest that the growth process of the particles is accelerated when the samples are treated at low heating rates. The evolution of particles size and the diffusion coefficient obtained from X-ray powder diffraction patterns are discussed in terms of the thermal conditions for the two types of detection.

Distribution of the first metastatic lymph node in colon cancer and its clinical significance.

INTRODUCTION: The pattern of distribution of lymph node metastasis in resected specimens of colon cancer has been rarely reported in the English literature. The aim of this study was to determine the location of the first metastatic lymph node, giving insight into the drainage pattern of colon cancer lymphatics. METHOD: All lymph nodes in the mesentery of the resected specimen were carefully harvested and their precise locations documented. Patients with a single metastatic node in the resected specimen were included in the study. RESULTS: Ninety-three patients with only one metastatic lymph node found on histology were studied. The mean number of lymph nodes per specimen was 22.3 (range: 8-72). The patients' first metastatic node was not directly below the tumour in 48% of cases. The first metastatic node was found in the region either along the feeding vessels (skipping the pericolic nodes) or in the pericolic area outside 5 cm on either side of the tumour edge in 18% of cases. No factors were found to be predictive for lymph node metastasis occurring elsewhere other than in the pericolic region just below the tumour. CONCLUSION: Although there has been recent resurgence of interest in using sentinel node biopsy to limit surgical dissection to facilitate minimally access and natural orifice surgery, the present study is a warning that this may compromise oncological clearance. Radical surgery should remain standard practice for colorectal cancer.

Accelerated learning curve for colorectal resection, open versus laparoscopic approach, can be attained with expert supervision.

BACKGROUND: Laparoscopic colorectal resection (LCR) is gaining popularity. Nonetheless, open surgery remains an important technique. Thus, surgeons should be technically proficient in both open and laparoscopic surgery. One question however remains unanswered: Can training for open and LCR occur simultaneously? The objective of this paper is to review the learning curve for open and laparoscopic colon resection of one surgeon who underwent a rigorous training program. METHODS: A review of consecutive patients who underwent surgery for colon and rectosigmoid junction cancers by one trainee surgeon was performed. This surgeon had completed his basic surgical residency but had limited experience in colorectal cancer surgery. In total, 75 patients were included in this study. All operations were supervised by at least one staff surgeon with experience of more than 300 LCR cases. The trainee surgeon was allowed to train in both laparoscopic and open colorectal resection simultaneously. RESULTS: Forty-three patients underwent laparoscopic resection, while 32 patients underwent open surgery. Age, gender, mean body mass index (BMI), preoperative risk, and history of past abdominal surgery showed no significant difference between laparoscopic and open groups. There were no differences in tumor stage [International Union against Cancer (UICC)] or tumor size (p = 0.068 and 0.228, respectively). The morbidity rate for open and laparoscopic surgery was 3.1% (1/32) and 4.7% (2/43), respectively (p = 0.484). Operation time decreased with increasing experience, and plateaued after 25 cases in the laparoscopic group and 22 cases in the open group. The learning curve for open cases was 11 cases, and 7 for laparoscopic surgery. CONCLUSIONS: Surgeons who have completed a basic surgical residency but have limited colorectal surgery experience can learn both open and laparoscopic colorectal surgery simultaneously in an effective manner under supervision by well-experienced surgeons.

VE-Cadherin and Anastomosis of Blood Vessels Formed by Dental Stem Cells.

It is known that dental pulp stem cells (DPSCs) can be induced to differentiate into vasculogenic endothelial (VE) cells. However, the process that results in sprouting and anastomosis of DPSC-derived vessels remains unclear. Here, we performed studies to understand the mechanisms underpinning the anastomosis of the host vasculature with blood vessels generated by DPSCs (a model for mesenchymal stem cells). VE-cadherin-silenced primary human DPSCs seeded in tooth slice/scaffolds and transplanted into the subcutaneous space of immunodeficient mice generated fewer functional blood vessels (i.e., anastomosed with the host vasculature) than control DPSCs transduced with scrambled sequences. Both VE-cadherin-silenced and mitogen-activated protein kinase kinase 1 (MEK1)-silenced cells showed a decrease in the number of capillary sprouts in vitro. Interestingly, DPSC stably transduced with a VE-cadherin reporter demonstrated that vascular endothelial growth factor (VEGF) induces VE-cadherin expression in sprouting DPSCs undergoing anastomosis, but not in quiescent DPSCs. To begin to understand the mechanisms regulating VE-cadherin, we stably silenced MEK1 and observed that VEGF was no longer able to induce VE-cadherin expression and capillary sprout formation. Notably ERG, a transcriptional factor downstream from MEK/ERK, binds to the promoter region of VE-cadherin (chip assay) and is induced by VEGF in DPSCs. Collectively, these data defined a signaling pathway triggered by VEGF that results in phosphorylation of MEK1/ERK and activation of ERG leading to expression of VE-cadherin, which is required for anastomosis of DPSC-derived blood vessels. In conclusion, these results unveiled a signaling pathway that enables the generation of functional blood vessels upon vasculogenic differentiation of DPSCs.

Conversion of bacteriorhodopsin into a chloride ion pump.

In the light-driven proton pump bacteriorhodopsin, proton transfer from the retinal Schiff base to aspartate-85 is the crucial reaction of the transport cycle. In halorhodopsin, a light-driven chloride ion pump, the equivalent of residue 85 is threonine. When aspartate-85 was replaced with threonine, the mutated bacteriorhodopsin became a chloride ion pump when expressed in Halobacterium salinarium and, like halorhodopsin, actively transported chloride ions in the direction opposite from the proton pump. Chloride was bound to it, as revealed by large shifts of the absorption maximum of the chromophore, and its photointermediates included a red-shifted state in the millisecond time domain, with its amplitude and decay rate dependent on chloride concentration. Bacteriorhodopsin and halorhodopsin thus share a common transport mechanism, and the interaction of residue 85 with the retinal Schiff base determines the ionic specificity.

Function of PI3Kgamma in thymocyte development, T cell activation, and neutrophil migration.

Phosphoinositide 3-kinases (PI3Ks) regulate fundamental cellular responses such as proliferation, apoptosis, cell motility, and adhesion. Viable gene-targeted mice lacking the p110 catalytic subunit of PI3Kgamma were generated. We show that PI3Kgamma controls thymocyte survival and activation of mature T cells but has no role in the development or function of B cells. PI3Kgamma-deficient neutrophils exhibited severe defects in migration and respiratory burst in response to heterotrimeric GTP-binding protein (G protein)-coupled receptor (GPCR) agonists and chemotactic agents. PI3Kgamma links GPCR stimulation to the formation of phosphatidylinositol 3,4,5-triphosphate and the activation of protein kinase B, ribosomal protein S6 kinase, and extracellular signal-regulated kinases 1 and 2. Thus, PI3Kgamma regulates thymocyte development, T cell activation, neutrophil migration, and the oxidative burst.

Colorectal surgery in octogenarian patients--outcomes and predictors of morbidity.

INTRODUCTION: Surgery for elderly patients pose a constant challenge. This study aims to review the outcome and find predictors of adverse outcome in octogenarians undergoing major colorectal resection for cancer. METHODS: A review of 121 octogenarians who underwent colorectal cancer surgery between September 1992 and May 2008 was performed. Comorbidities were quantified using the weighted Charlson Comorbidity Index and ASA classification. CR-POSSUM scores and ACPGBI scores and the predicted mortality rates were calculated. Outcome measures were morbidity rates and 30-day mortality rates. RESULTS: The patients had a mean age of 83.5 years (range, 80-99). The mean index of comorbidity was 3.1 (2-7) and 12.5% of patients were classified ASA III and above. The mean predicted mortality rate based on CR-POSSUM and ACPGBI scoring models were 11.2% and 5.4% respectively. The overall observed morbidity rate was 30.7% and 30-day mortality was 1.6. Factors found on bivariate analysis to be significantly associated with an increased risk of morbidity were tumor presenting with complication, comorbid coronary heart disease, serum urea levels, ASA classification > or =3 and comorbidity index 3 of 5 > or = 5. Multivariate analysis revealed the latter two factors to be independent predictors of morbidity. CONCLUSION: Octogenarians undergoing major colorectal resection have an acceptable perioperative morbidity and mortality rate and survival rate and should not be denied surgery based on age alone. Comorbidity index scores and ASA scores are useful tools to identify poor risk patients.

Understanding the anatomy of lymphatic drainage and the use of blue-dye mapping to determine the extent of lymphadenectomy in rectal cancer surgery: unresolved issues.

OBJECTIVE: This paper reviews the literature on the pathways of lymphatic drainage of the rectum and their significance in radical cancer surgery. METHOD: This paper reviews some of the seminal works on the lymphatic drainage of the rectum and its surgical implications when operating on patients with rectal cancer. Publications were searched via Medline, sourced from reference lists and by cross referencing with the most widely cited papers. RESULTS: The classical European description of the anatomy of the lymphatic drainage of the rectum is presented. Early lymphatic mapping techniques and the role of newer technologies in lymphatic mapping, including sentinel lymph node mapping are discussed. The differing philosophies between Western practice, of dissection in the plane of the fascia propria and the Japanese wider pelvic lymphadenectomy are discussed. CONCLUSIONS: A clear understanding of the regional lymphatic drainage of the rectum and precise anatomical mobilisation of the rectum is the surgical cornerstone to excellent locoregional control of rectal cancer. The success of the differing Western and Japanese philosophies on the degree of pelvic lymphadenectomy suggests a possible role for 'selective wide pelvic lymphadectomy'. Mapping lateral lymphatic drainage pathways could augment the selection process for radiotherapy.

Sushi-roll wrap of Seprafilm for ileostomy limbs facilitates ileostomy closure.

BACKGROUND: Sodium hyaluronate and carboxymethylcellulose membrane (Seprafilm) reduced postoperative intraabdominal adhesion. In this study, we examined whether Seprafilm reduces operative difficulties in ileostomy closure. PATIENTS AND METHODS: During the creation of the ileostomy, Seprafilm was cut in half and used to wrap both the ileum and mesentery. Patients who underwent ileostomy closure before February 2008 (without Seprafilm, Group T, n = 18) and after March (with Seprafilm, Group S, n = 18) were enrolled in this study. All operations were performed by surgical residents. Operative time and perioperative complications were analyzed. RESULTS: The mean operative time of Group S (106.88 min) was significantly less than that of Group T (120.6 min). The amount of intraoperative bleeding in Groups S and T was not significantly different and there were no major complications. CONCLUSION: Seprafilm applied to the two limbs of the ileostomy and mesentery facilitate ileostomy closure done by non-expert surgeons.

X-ray diffraction in superabsorbing crystals: absorption intrinsic width.

The several mathematical formulations of X-ray diffraction theory facilitate its understanding and use as a materials characterization technique, since one can opt for the simplest formulation that adequately describes the case being studied. As synchrotrons advance, new techniques are developed and there is a need for simple formulations to describe them. One of these techniques is soft resonant X-ray diffraction, in which the X-rays suffer large attenuation due to absorption. In this work, an expression is derived for the X-ray diffraction profiles of reflections where the linear absorption is far greater than primary extinction; in other words, the crystal is superabsorbing. The case is considered of a parallel plate crystal, for which the diffraction profile of the superabsorbing crystal is computed as a function of crystal size normal to the diffraction planes. For thin crystals or those with negligible absorption, the diffraction profile of a superabsorbing crystal coincides with the result of the kinematical theory. For thick crystals, the absorption intrinsic profile is obtained, described by a Lorentzian function and characterized by the absorption intrinsic width. This absorption intrinsic width is proportional to the linear absorption coefficient and its expression is similar to that for the Darwin width, while the absorption intrinsic profile is a special case of the Laue dynamical theory, and it is similar to the Ornstein-Zernike Lorentzian. The formulation of X-ray diffraction of superabsorbing crystals is simple and provides new perspectives for the soft resonant X-ray diffraction technique.

The phosphoinositide-3 kinase gamma-Akt pathway mediates renal tubular injury in cisplatin nephrotoxicity.

Nephrotoxicity is a frequent complication of cisplatin-based chemotherapy often limiting its use. In this study, we attempted to the role of the phosphoinositide-3 kinase (PI3K)-gamma-Akt pathway in this form of acute kidney injury. Using PI3K-gamma knockout mice, we found that a conventional dose of cisplatin was more lethal in the knockout mice where the blood urea nitrogen and serum creatinine were significantly higher in them than in wild-type mice. Phosphorylation of Akt in the renal tubules was abrogated in the knockout mice with the severity of renal dysfunction and numbers of TUNEL (terminal deoxynucleotidyl transferase (TdT) mediated nick-end labeling)-positive renal tubule cells being higher in the knockout than in wild-type mice. Cisplatin treatment significantly increased. Caspase-3 activity, histone-associated DNA fragments, and number of annexin V-positive cells was significantly higher in cisplatin-treated primary cultured renal tubular epithelial cells of knockout mice. Transfection of dominant-active forms of Akt and PI3K-gamma ameliorated apoptosis of the tubule epithelial cells derived from the knockout mice. Our results suggest that the PI3K-gamma-Akt pathway lessens apoptosis and plays a critical role in the maintenance of renal function in cisplatin-induced acute kidney injury.

Effect of direct hemoperfusion using polymyxin B immobilized fiber on inflammatory mediators in patients with severe sepsis and septic shock.

The objective of this study was to investigate retrospectively the effect of direct hemoperfusion using polymyxin B immobilized fiber (PMX-DHP) in a cartridge to remove endotoxin on inflammatory mediators in septic patients. PMX-DHP was performed 59 times in 40 patients with severe sepsis and septic shock due to gram-negative bacterial infection. Mean age and APACHE II score were 63 years and 22, respectively. The first treatments with PMX-DHP were started when patient hemodynamics were unstable even after conventional therapies. The second treatments were performed in 19 patients whose hemodynamics were still unstable after the first PMX-DHP. The changes in inflammatory mediator levels were compared from baseline to post treatment with PMX-DHP. Statistical differences were calculated using the Wilcoxon rank sum test. Plasma endotoxin could be detected in 34 patients, which was significantly decreased in 20 cases measured by a chromogenic kinetic limulus amebocyte lysate assay (p=0.0254) and in 14 cases measured by a new limulus turbidimetric time assay (p=0.0196). Monocyte counts in peripheral blood decreased significantly (p=0.0402). Interleukin-6 decreased significantly (p=0.0020). Blood pyruvate also decreased significantly (p=0.0025). At the same time, mean arterial pressure, pulse pressure, systemic vascular resistance index, and urine output were significantly increased. These results indicated that PMX-DHP could decrease inflammatory mediators and be effective to interrupt the pathogenic sequence leading to septic shock due to gram-negative bacterial infection.

The limit of application of the Scherrer equation.

The Scherrer equation is a widely used tool to obtain crystallite size from polycrystalline samples. Its limit of applicability has been determined recently, using computer simulations, for a few structures and it was proposed that it is directly dependent on the linear absorption coefficient (µ0) and Bragg angle (θB). In this work, a systematic study of the Scherrer limit is presented, where it is shown that it is equal to approximately 11.9% of the extinction length. It is also shown that absorption imposes a maximum value on it and that this maximum is directly proportional to sin θB/µ0.

Pulp Regeneration by 3-dimensional Dental Pulp Stem Cell Constructs.

Dental pulp regeneration therapy for the pulpless tooth has attracted recent attention, and clinical trial studies are underway with the tissue engineering approach. However, there remain many concerns, including the extended period for regenerating the dental pulp. In addition, the use of scaffolds increases the risk of inflammation and infection. To establish a basic technology for novel dental pulp regenerative therapy that allows transplant of pulp-like tissue, we attempted to fabricate scaffold-free 3-dimensional (3D) cell constructs composed of dental pulp stem cells (DPSCs). Furthermore, we assessed viability of these 3D DPSC constructs for dental pulp regeneration through in vitro and in vivo studies. For the in vitro study, we obtained 3D DPSC constructs by shaping sheet-like aggregates of DPSCs with a thermoresponsive hydrogel. DPSCs within constructs remained viable even after prolonged culture; furthermore, 3D DPSC constructs possessed a self-organization ability necessary to serve as a transplant tissue. For the in vivo study, we filled the human tooth root canal with DPSC constructs and implanted it subcutaneously into immunodeficient mice. We found that pulp-like tissues with rich blood vessels were formed within the human root canal 6 wk after implantation. Histologic analyses revealed that transplanted DPSCs differentiated into odontoblast-like mineralizing cells at sites in contact with dentin; furthermore, human CD31-positive endothelial cells were found at the center of regenerated tissue. Thus, the self-organizing ability of 3D DPSC constructs was active within the pulpless root canal in vivo. In addition, blood vessel-rich pulp-like tissues can be formed with DPSCs without requiring scaffolds or growth factors. The technology established in this study allows us to prepare DPSC constructs with variable sizes and shapes; therefore, transplantation of DPSC constructs shows promise for regeneration of pulpal tissue in the pulpless tooth.