Dental caries prevalence in children during temporary protective care according to type of abuse.

BACKGROUND: This study investigated the correlation between the prevalence of dental caries and the presence and type of abuse. METHODS: Participants were 534 children admitted for care at two child guidance centers (CGCs) in Niigata, Japan. Data pertaining to abuse, including the reason for temporary protective care and the type of abuse, and the oral examination results of the children, were collected. These results were then compared with those of a national survey and analyzed in relation to the presence and type of abuse. RESULTS: The odds ratio for decayed teeth was 4.1, indicating a higher risk in children admitted to the CGCs. However, no significant association was found between the presence of decayed, filled, or caries-experienced teeth and the presence of abuse. A significant positive association was observed between dental caries and one type of abuse, indicating a greater prevalence of dental caries in cases of neglect. The findings of this study suggest that the type of abuse, rather than its presence, is associated with dental caries. CONCLUSIONS: Our findings suggest that proactive support should be provided to children in problematic nurturing environments, regardless of whether they have been subjected to abuse.

The Role of Genetically Modified Human Feeder Cells in Maintaining the Integrity of Primary Cultured Human Deciduous Dental Pulp Cells.

Tissue-specific stem cells exist in tissues and organs, such as skin and bone marrow. However, their pluripotency is limited compared to embryonic stem cells. Culturing primary cells on plastic tissue culture dishes can result in the loss of multipotency, because of the inability of tissue-specific stem cells to survive in feeder-less dishes. Recent findings suggest that culturing primary cells in medium containing feeder cells, particularly genetically modified feeder cells expressing growth factors, may be beneficial for their survival and proliferation. Therefore, the aim of this study was to elucidate the role of genetically modified human feeder cells expressing growth factors in maintaining the integrity of primary cultured human deciduous dental pulp cells. Feeder cells expressing leukemia inhibitory factor, bone morphogenetic protein 4, and basic fibroblast growth factor were successfully engineered, as evidenced by PCR. Co-culturing with mitomycin-C-treated feeder cells enhanced the proliferation of newly isolated human deciduous dental pulp cells, promoted their differentiation into adipocytes and neurons, and maintained their stemness properties. Our findings suggest that genetically modified human feeder cells may be used to maintain the integrity of primary cultured human deciduous dental pulp cells.

Lip-closing strength in children is enhanced by lip and facial muscle training.

OBJECTIVES: Weakening of lip-closing strength (LCS) associated with an incompetent lip seal (ILS) may affect the oral balance between the lip and tongue pressures. The purpose of this study was to evaluate the effects of lip-closing training in children with lower LCS and/or abnormal habits across different age groups and to compare its effects on increasing LCS in children with malocclusion and/or oral habits. MATERIAL AND METHODS: Lip-closing training was performed by 154 Japanese children aged 3-12 years using a specialized training device at home for 3 months. Children with oral habits and/or exhibiting less than standard LCS were included. LCS was measured using a digital strain force gauge at a dental clinic at the beginning (T0) and after each month (after 3 months: T3). RESULTS: Children had higher LCS responses after lip-closing training. The first month of lip-closing training was more effective than the subsequent months. With lip-closing training, the LCS increased from an average of 6.2 N (T0) to 11.4 N (T3) in Group I, 7.9 N (T0) to 12.8 N (T3) in Group II, and 6.8 N to 11.4 N in Group III. Anterior cross bite, including reverse bite, open bite, and tongue thrusting, significantly reduced training effects. CONCLUSION: Our findings showed that lower LCS in children with ILS resulted in greater responses to lip-closing training in a short period, but oral dysfunction, such as abnormal habits, inhibited the positive effects of training. Our results suggest that less detrimental effects of malocclusion and abnormal oral habits lip-closing training enhances LCS in younger children.

Oral Function and Feeding Management in a Child with Alpha Thalassemia X-Linked Intellectual Disability Syndrome.

Alpha-thalassemia X-linked intellectual disability (ATR-X) syndrome affects males and is associated with profound developmental delay, facial dysmorphism, genital abnormalities, and alpha thalassemia. Appropriate oral health management for affected patients is important. The purposes of this report are to describe a case involving six years of oral health management, including training in eating, drinking and swallowing, for a patient with ATR-X syndrome, and to discuss the morphological and functional oral characteristics of this disorder. The patient's oral dysfunctions were incompetent lip-closing, inappropriate tongue protrusion, deviation of chewing acquisition, and incompetent oral and pharyngeal bolus propulsion. Other problems included inappropriate ingestion posture, low interest in meals, and poor oral hygiene. A stable oral intake and an improved eating posture were achieved through an intervention; however, the patient's inappropriate tongue protrusion, deviation of chewing acquisition, and incompetent bolus propulsion remained unchanged.

Tissue-Nonspecific Alkaline Phosphatase, a Possible Mediator of Cell Maturation: Towards a New Paradigm.

Alkaline phosphatase (ALP) is a ubiquitous membrane-bound glycoprotein capable of providing inorganic phosphate by catalyzing the hydrolysis of organic phosphate esters, or removing inorganic pyrophosphate that inhibits calcification. In humans, four forms of ALP cDNA have been cloned, among which tissue-nonspecific ALP (TNSALP) (TNSALP) is widely distributed in the liver, bone, and kidney, making it an important marker in clinical and basic research. Interestingly, TNSALP is highly expressed in juvenile cells, such as pluripotent stem cells (i.e., embryonic stem cells and induced pluripotent stem cells (iPSCs)) and somatic stem cells (i.e., neuronal stem cells and bone marrow mesenchymal stem cells). Hypophosphatasia is a genetic disorder causing defects in bone and tooth development as well as neurogenesis. Mutations in the gene coding for TNSALP are thought to be responsible for the abnormalities, suggesting the essential role of TNSALP in these events. Moreover, a reverse-genetics-based study using mice revealed that TNSALP is important in bone and tooth development as well as neurogenesis. However, little is known about the role of TNSALP in the maintenance and differentiation of juvenile cells. Recently, it was reported that cells enriched with TNSALP are more easily reprogrammed into iPSCs than those with less TNSALP. Furthermore, in bone marrow stem cells, ALP could function as a "signal regulator" deciding the fate of these cells. In this review, we summarize the properties of ALP and the background of ALP gene analysis and its manipulation, with a special focus on the potential role of TNSALP in the generation (and possibly maintenance) of juvenile cells.

RNA analysis based on a small number of manually isolated fixed cells (RNA-snMIFxC) to profile stem cells from human deciduous tooth-derived dental pulp cells.

BACKGROUND: Expression of stemness factors, such as octamer-binding transcription factor 3/4 (OCT3/4), sex determining region Y-box 2 (SOX2), and alkaline phosphatase (ALP) in human deciduous tooth-derived dental pulp cells (HDDPCs) can be assessed through fixation and subsequent immuno- or cytochemical staining. Fluorescence-activated cell sorting (FACS), a powerful system to collect cells of interest, is limited by the instrument cost and difficulty in handling. Magnetic-activated cell sorting is inexpensive compared to FACS, but is confined to cells with surface expression of the target molecule. In this study, a simple and inexpensive method was developed for the molecular analysis of immuno- or cytochemically stained cells with intracellular expression of a target molecule, through isolation of a few cells under a dissecting microscope using a mouthpiece-controlled micropipette. RESULTS: Two or more colored cells (~ 10), after staining with a chromogen such a 3,3'-diaminobenzidine, were successfully segregated from unstained cells. Expression of glyceraldehyde 3-phosphate dehydrogenase, a housekeeping gene, was discernible in all samples, while the expression of stemness genes (such as OCT3/4, SOX2, and ALP) was confined to positively stained cells. CONCLUSION: These findings indicate the fidelity of these approaches in profiling cells exhibiting cytoplasmic or nuclear localization of stemness-specific gene products at a small-scale.

Induced Tissue-Specific Stem Cells (iTSCs): Their Generation and Possible Use in Regenerative Medicine.

Induced tissue-specific stem cells (iTSCs) are partially reprogrammed cells which have an intermediate state, such as progenitors or stem cells. They originate from the de-differentiation of differentiated somatic cells into pluripotent stem cells, such as induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs), or from the differentiation of undifferentiated cells. They show a limited capacity to differentiate and a morphology similar to that of somatic cell stem cells present in tissues, but distinct from that of iPSCs and ESCs. iTSCs can be generally obtained 7 to 10 days after reprogramming of somatic cells with Yamanaka's factors, and their fibroblast-like morphology remains unaltered. iTSCs can also be obtained directly from iPSCs cultured under conditions allowing cellular differentiation. In this case, to effectively induce iTSCs, additional treatment is required, as exemplified by the conversion of iPSCs into naïve iPSCs. iTSCs can proliferate continuously in vitro, but when transplanted into immunocompromised mice, they fail to generate solid tumors (teratomas), implying loss of tumorigenic potential. The low tendency of iTSCs to elicit tumors is beneficial, especially considering applications for regenerative medicine in humans. Several iTSC types have been identified, including iTS-L, iTS-P, and iTS-D, obtained by reprogramming hepatocytes, pancreatic cells, and deciduous tooth-derived dental pulp cells, respectively. This review provides a brief overview of iPSCs and discusses recent advances in the establishment of iTSCs and their possible applications in regenerative medicine.

Lip-closing pressure during food intake from a spoon in normal children.

BACKGROUND: Understanding the refinement of self-feeding skills is useful for the assessment of oral functional development in children. OBJECTIVES: To determine normative data on lip closing during food intake in the development of independent spoon-feeding in normal children, we tested the hypothesis that lip-closing pressure and spoon operation differ depending on food type. METHODS: Fifteen normal children (eight boys, seven girls; mean age: 6.5 years) were asked to eat test foods (2, 3 and 5 g of yogurt and cream cheese) freely with a spoon. Lip-closing pressures and kinematic data on spoon operation were recorded simultaneously with a strain gauge transducer embedded in the spoon and Vicon motion analysis, respectively. RESULTS: In the most common lip-pressure pattern, only positive pressure was generated. In the second most common pattern, negative pressure occurred first, followed by positive pressure; this pattern was seen infrequently. Positive pressure (P < .001), pressure duration (P < .001) and spoon intra-oral time (P < .05) during intake of cream cheese (an adhesive food) were significantly greater than those during intake of yogurt (a non-adhesive food). Pressure onset occurred at the beginning of the spoon withdrawal period or at the turning point from spoon insertion to withdrawal, depending on the food. CONCLUSIONS: Lip-closing force and spoon operation varied depending on food type in preschool and early elementary school children. Our findings suggest the need to consider the importance of food diversity and to pay attention to the spoon withdrawal period when assessing the development and maturation of lip function.

Prevalence of an incompetent lip seal during growth periods throughout Japan: a large-scale, survey-based, cross-sectional study.

BACKGROUND: Systemic and local factors may lead to disruption of craniofacial growth and development, causing an imbalance between the orofacial skeleton, muscle and soft tissue, dental occlusion, and the dental arch during growth periods. We aimed to reveal whether the prevalence of incompetent lip seal (ILS) varies with age and region, as well as to clarify the factors related to an ILS, in a national, large-scale epidemiological study. METHODS: We surveyed 3399 children, from 3 to 12 years of age, visiting 66 pediatric dental clinics throughout Japan. For this survey, we employed a questionnaire consisting of 44 questions regarding daily health conditions and lifestyle habits. We evaluated the differences in ILS prevalence by age and region (using a Cochran-Armitage test for trend and a Kruskal-Wallis test), and the relationship between ILS and factors investigated in the questionnaire (using Spearman's rank correlation coefficient). RESULTS: We observed that 30.7% of Japanese children exhibited an ILS and that the ILS rate increased with age (p < 0.001). There were no regional differences in the rate of ILS in Japanese children (p = 0.506). We revealed that 12 of 44 survey items exhibited a statistically significant correlation with ILS (p < 0.001), using Spearman's rank correlation coefficient. These items involved orofacial morphology, mouth breathing, and possibly, allergic rhinitis. CONCLUSION: The rate of ILS seems to increase with age in children, throughout Japan. Therefore, this disorder may not self-correct during the growth periods in these children. Guidelines are required for pediatric dentists to recognize ILS among children aged 3-12 years.

Drug-Induced Naïve iPS Cells Exhibit Better Performance than Primed iPS Cells with Respect to the Ability to Differentiate into Pancreatic ß-Cell Lineage.

Pluripotent stem cells are classified as naïve and primed cells, based on their in vitro growth characteristics and potential to differentiate into various types of cells. Human-induced pluripotent stem cells (iPSCs, also known as epiblast stem cells [EpiSCs]) have limited capacity to differentiate and are slightly more differentiated than naïve stem cells (NSCs). Although there are several in vitro protocols that allow iPSCs to differentiate into pancreatic lineage, data concerning generation of ß-cells from these iPSCs are limited. Based on the pluripotentiality of NSCs, it was hypothesized that NSCs can differentiate into pancreatic ß-cells when placed under an appropriate differentiation induction condition. We examined whether NSCs can be efficiently induced to form potentially pancreatic ß cells after being subjected to an in vitro protocol. Several colonies resembling in vitro-produced ß-cell foci, with ß-cell-specific marker expression, were observed when NSC-derived embryoid bodies (EBs) were induced to differentiate into ß-cell lineage. Conversely, EpiSC-derived EBs failed to form such foci in vitro. Intrapancreatic grafting of the in vitro-formed ß-cell foci into nude mice (BALB/c-nu/nu) generated a cell mass containing insulin-producing cells (IPCs), without noticeable tumorigenesis. These NSCs can be used as a promising resource for curing type 1 diabetes.

Influence of food adhesivity and quantity in lip closing pressure.

Lip closing is an important motor act in food acquisition. Appropriate food capture in anticipatory and early oral stages of feeding is essential for mastication and swallowing. The aim of this study was to investigate the effect of food type and quantity on lip closing pressure during food capture with a spoon, and to identify normal lip function during food acquisition in healthy young adults. Twenty young healthy males (age range: 22-30 years) participated in this study. They were asked to eat the test food freely with a spoon. Test foods were yogurt and cream cheese, which were given in quantities of 3, 5 and 10 g in weight; 3 ml water was included as a reference. A strain gauge transducer was embedded in the spoon in advance, and lip closing pressures during food capture were measured and recorded. The Vicon motion analysis system was used to collect three-dimensional kinematic data of spoon operation. Positive pressure with lip closing during capture of adhesive food, such as cream cheese, significantly increased (P < 0.001). Moreover, positive pressure significantly decreased when food quantity increased (P < 0.01), irrespective of food type. Negative pressure that preceded positive pressure appeared more frequently during cream cheese intake and increased when food quantity on the spoon increased (P < 0.001). These findings indicated that participants sucked or squeezed the spoon further during capture of adhesive food. Maximum mouth opening occurred predominantly during the spoon insertion period, while mouth closing occurred predominantly during the spoon withdrawal period. After mouth closing, all subsequent lip pressure events appeared in the withdrawal period. Our results may be useful for comprehending normal lip function during food acquisition in healthy young adults. They may also aid in the diagnosis and management of abnormal lip function in oral hypofunction and dysfunction, which can be examined in future studies.

piggyBac Transposon-Based Immortalization of Human Deciduous Tooth Dental Pulp Cells with Multipotency and Non-Tumorigenic Potential.

We aimed to immortalize primarily isolated human deciduous tooth-derived dental pulp cells (HDDPCs) by transfection with piggyBac (PB)-based transposon vectors carrying E7 from human papilloma virus 16 or complementary DNA (cDNA) encoding human telomerase reverse transcriptase (hTERT). HDDPCs were co-transfected with pTrans (conferring PB transposase expression) + pT-pac (conferring puromycin acetyltransferase expression) + pT-tdTomato (conferring tdTomato cDNA expression) and pT-E7 (conferring E7 expression) or pTrans + pT-pac + pT-EGFP (conferring enhanced green fluorescent protein cDNA expression) + pT-hTERT (conferring hTERT expression). After six days, these cells were selected in medium containing 5 µg/mL puromycin for one day, and then cultured in normal medium allowing cell survival. All resultant colonies were harvested and propagated as a pool. Stemness and tumorigenic properties of the established cell lines ("MT_E7" for E7 and "MT_hTERT" for hTERT) with untransfected parental cells (MT) were examined. Both lines exhibited proliferation similar to that of MT, with alkaline phosphatase activity and stemness-specific factor expression. They displayed differentiation potential into multi-lineage cells with no tumorigenic property. Overall, we successfully obtained HDDPC-derived immortalized cell lines using a PB-based transfection system. The resultant and parental cells were indistinguishable. Thus, E7 and hTERT could immortalize HDDPCs without causing cancer-associated changes or altering phenotypic properties.

Increased Expression of Cell Surface SSEA-1 is Closely Associated with Naïve-Like Conversion from Human Deciduous Teeth Dental Pulp Cells-Derived iPS Cells.

Stage-specific embryonic antigen 1 (SSEA-1) is an antigenic epitope (also called CD15 antigen) defined as a Lewis X carbohydrate structure and known to be expressed in murine embryonal carcinoma cells, mouse embryonic stem cells (ESCs), and murine and human germ cells, but not human ESCs/induced pluripotent stem cells (iPSCs). It is produced by α1,3-fucosyltransferase IX gene (FUT9), and F9 ECCs having a disrupted FUT9 locus by gene targeting are reported to exhibit loss of SSEA-1 expression on their cell surface. Mouse ESCs are pluripotent cells and therefore known as "naïve stem cells (NSCs)." In contrast, human ESCs/iPSCs are thought to be epiblast stem cells (EpiSCs) that are slightly more differentiated than NSCs. Recently, it has been demonstrated that treatment of EpiSCs with several reprograming-related drugs can convert EpiSCs to cells similar to NSCs, which led us to speculate that SSEA-1 may have been expressed in these NSC-like EpiSCs. Immunocytochemical staining of these cells with anti-SSEA-1 revealed increased expression of this epitope. RT-PCR analysis also confirmed increased expression of FUT9 transcripts as well as other stemness-related transcripts such as REX-1 (ZFP42). These results suggest that SSEA-1 can be an excellent marker for human NSCs.

Repeated human deciduous tooth-derived dental pulp cell reprogramming factor transfection yields multipotent intermediate cells with enhanced iPS cell formation capability.

Human tissue-specific stem cells (hTSCs), found throughout the body, can differentiate into several lineages under appropriate conditions in vitro and in vivo. By transfecting terminally differentiated cells with reprogramming factors, we previously produced induced TSCs from the pancreas and hepatocytes that exhibit additional properties than iPSCs, as exemplified by very low tumour formation after xenogenic transplantation. We hypothesised that hTSCs, being partially reprogrammed in a state just prior to iPSC transition, could be isolated from any terminally differentiated cell type through transient reprogramming factor overexpression. Cytochemical staining of human deciduous tooth-derived dental pulp cells (HDDPCs) and human skin-derived fibroblasts following transfection with Yamanaka's factors demonstrated increased ALP activity, a stem cell marker, three weeks after transfection albeit in a small percentage of clones. Repeated transfections (≤3) led to more efficient iPSC generation, with HDDPCs exhibiting greater multipotentiality at two weeks post-transfection than the parental intact HDDPCs. These results indicated the utility of iPSC technology to isolate TSCs from HDDPCs and fibroblasts. Generally, a step-wise loss of pluripotential phenotypes in ESCs/iPSCs occurs during their differentiation process. Our present findings suggest that the reverse phenomenon can also occur upon repeated introduction of reprogramming factors into differentiated cells such as HDDPCs and fibroblasts.

Isolation and characterization of lymphoid enhancer factor-1-positive deciduous dental pulp stem-like cells after transfection with a piggyBac vector containing LEF1 promoter-driven selection markers.

OBJECTIVE: Lymphoid enhancer-binding factor-1 (LEF1) is a 48-kD nuclear protein that is expressed in pre-B and T cells. LEF1 is also an important member of the Wnt/ß-catenin signaling pathway that plays important roles in the self-renewal and differentiation of embryonic stem cells. We speculated that LEF1 might function in the stem cells from human exfoliated deciduous teeth (SHED). In this study, we attempted to isolate such LEF1-positive cells from human deciduous dental pulp cells (HDDPCs) by genetic engineering technology, using the human LEF1 promoter. DESIGN: A piggyBac transposon plasmid (pTA-LEN) was introduced into HDDPCs, using the Neon® transfection system. After G418 selection, the emerging colonies were assessed for EGFP-derived fluorescence by fluorescence microscopy. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed using RNA isolated from these colonies to examine stem cell-specific transcript expression. Osteoblastic or neuronal differentiation was induced by cultivating the LEF1-positive cells with differentiation-inducing medium. RESULTS: RT-PCR analysis confirmed the expression of several stem cell markers, including OCT3/4, SOX2, REX1, and NANOG, in LEF1-positive HDDPCs, which could be differentiated into osteoblasts and neuronal cells. CONCLUSIONS: The isolated LEF1-positive HDDPCs exhibited the properties of stem cells, suggesting that LEF1 might serve as a marker for SHED.

Tissue-Specific Stem Cells Obtained by Reprogramming of Non-Obese Diabetic (NOD) Mouse-Derived Pancreatic Cells Confer Insulin Production in Response to Glucose.

Type 1 diabetes occurs due to the autoimmune destruction of pancreatic ß-cells in islets. Transplantation of islets is a promising option for the treatment of patients with type 1 diabetes that experience hypoglycemic unawareness despite maximal care, but the present shortage of donor islets hampers such transplantation. Transplantation of insulin-producing cells derived from the patients themselves would be one of the most promising approaches to cure type 1 diabetes. Previously, we demonstrated that insulin-producing cells could be produced by transfecting murine pancreatic cells with Yamanaka's reprogramming factors. Non-obese diabetic (NOD) mice are naturally occurring mutant mice defective in insulin production due to autoimmune ablation of pancreatic ß-cells. In this study, we showed that glucose-sensitive insulin-producing cells are successfully generated by transfecting primary pancreatic cells from NOD mice (aged 6 months old) with a plasmid harboring the cDNAs for Oct-3/4, Sox2, Klf4, and c-Myc. Transfection was repeated 4 times in a 2 day-interval. Sixty-five days after final transfection, cobblestone-like colonies appeared. They proliferated in vitro and expressed pluripotency-related genes as well as Pdx1, a transcription factor specific to tissue-specific stem cells for the ß-cell lineage. Transplantation of these cells into nude mice failed to produce teratoma unlike induced pluripotent stem cells (iPSCs). Induction of these cells to the pancreatic ß-cell lineage demonstrated their capability to produce insulin in response to glucose. These findings suggest that functional pancreatic ß-cells can be produced from patients with type 1 diabetes. We call these resultant cells as "induced tissue-specific stem cells from the pancreas" (iTS-P) that could be valuable sources of safe and effective materials for cell-based therapy in type 1 diabetes.

Quantitative evaluation of toothbrush and arm-joint motion during tooth brushing.

OBJECTIVES: It is very difficult for dental professionals to objectively assess tooth brushing skill of patients, because an obvious index to assess the brushing motion of patients has not been established. The purpose of this study was to quantitatively evaluate toothbrush and arm-joint motion during tooth brushing. MATERIALS AND METHODS: Tooth brushing motion, performed by dental hygienists for 15 s, was captured using a motion-capture system that continuously calculates the three-dimensional coordinates of object's motion relative to the floor. The dental hygienists performed the tooth brushing on the buccal and palatal sides of their right and left upper molars. The frequencies and power spectra of toothbrush motion and joint angles of the shoulder, elbow, and wrist were calculated and analyzed statistically. RESULTS: The frequency of toothbrush motion was higher on the left side (both buccal and palatal areas) than on the right side. There were no significant differences among joint angle frequencies within each brushing area. The inter- and intra-individual variations of the power spectrum of the elbow flexion angle when brushing were smaller than for any of the other angles. CONCLUSIONS: This study quantitatively confirmed that dental hygienists have individual distinctive rhythms during tooth brushing. All arm joints moved synchronously during brushing, and tooth brushing motion was controlled by coordinated movement of the joints. The elbow generated an individual's frequency through a stabilizing movement. CLINICAL RELEVANCE: The shoulder and wrist control the hand motion, and the elbow generates the cyclic rhythm during tooth brushing.

Choice of Feeders Is Important When First Establishing iPSCs Derived From Primarily Cultured Human Deciduous Tooth Dental Pulp Cells.

Feeder cells are generally required to maintain embryonic stem cells (ESCs)/induced pluripotent stem cells (iPSCs). Mouse embryonic fibroblasts (MEFs) isolated from fetuses and STO mouse stromal cell line are the most widely used feeder cells. The aim of this study was to determine which cells are suitable for establishing iPSCs from human deciduous tooth dental pulp cells (HDDPCs). Primary cultures of HDDPCs were cotransfected with three plasmids containing human OCT3/4, SOX2/KLF4, or LMYC/LIN28 and pmaxGFP by using a novel electroporation method, and then cultured in an ESC qualified medium for 15 days. Emerging colonies were reseeded onto mitomycin C-treated MEFs or STO cells. The colonies were serially passaged for up to 26 passages. During this period, colony morphology was assessed to determine whether cells exhibited ESC-like morphology and alkaline phosphatase activity to evaluate the state of cellular reprogramming. HDDPCs maintained on MEFs were successfully reprogrammed into iPSCs, whereas those maintained on STO cells were not. Once established, the iPSCs were maintained on STO cells without loss of pluripotency. Our results indicate that MEFs are better feeder cells than STO cells for establishing iPSCs. Feeder choice is a key factor enabling efficient generation of iPSCs.

Associations between the autonomic nervous system and the second derivative of the finger photoplethysmogram indices.

AIM: The indices of the second derivative of the finger photoplethysmogram(SDPTG) denote stiffness of large arteries, peripheral vascular resistance and vascular aging. However, the association between the autonomic nervous activity and the SDPTG indices has not yet been elucidated. METHODS: The SDPTG and heart rate variability(HRV) were consecutively measured in the sitting position on the day before surgery in 168 patients 18-89 years of age. The relationships between the SDPTG indices(b/a, c/a, d/a and e/a) and HRV indices(power spectral analysis and time domain analysis parameters) were analyzed. The relationships between c/a and atherosclerosis-based conditions and risk factors for atherosclerosis were also evaluated. RESULTS: The SDPTG index b/a was negatively associated and the d/a index was positively associated with the low-frequency(LF)(R=-0.44 and 0.42, respectively) and high-frequency(HF) components(R=-0.31 and 0.35, respectively). The SDPTG index c/a was also positively associated with the LF(R=0.40) and HF(R=0.44) components. A multivariate regression analysis showed that the LF, HF and heart rate were independent determinants of the c/a. Furthermore, the c/a values were significantly lower in the patients with hypertension, diabetes mellitus and hyperlipidemia than in those without these diseases, and a reduced c/a was significantly associated with increased serum triglyceride and total cholesterol concentrations. CONCLUSIONS: These findings suggest that a decrease in c/a is associated with a reduced baroreflex response of the peripheral vasomotor activity and a decreased cardiac parasympathetic activity. Furthermore, a decrease in c/a was found to be associated with atherosclerosis-based conditions, such as hypertension, diabetes mellitus and hyperlipidemia.

Analysis of tooth brushing cycles.

OBJECTIVE: The aim of this study was to demonstrate the effectiveness of an analysis of tooth brushing cycles using a system that measures tooth brushing motion and brushing force with an accelerometer and strain tension gage attached to a toothbrush. BACKGROUND: Mechanical plaque removal with a manual toothbrush remains the primary method of maintaining good oral hygiene for the majority of the population. Because toothbrush motion has not been fully understood, it should be clarified by analysis of tooth brushing cycles. METHODS: Twenty healthy female dental hygienists participated in this study. Their tooth brushing motions were measured and analyzed using an American Dental Association-approved manual toothbrush to which a three-dimensional (3-D) accelerometer and strain tension gage were attached. 3-D motion and brushing force on the labial surface of the mandibular right central incisor and the lingual surface of the mandibular left first molar were measured, analyzed, and compared. Multilevel linear model analysis was applied to estimate variables and compare motion and forces related to the two tooth surfaces. RESULTS: The analysis of tooth brushing cycles was feasible, and significant differences were detected for durations and 3-D ranges of toothbrush motion as well as brushing force between the two tooth surfaces. CONCLUSION: The analysis used in this study demonstrated an ability to detect characteristics of tooth brushing motion, showing tooth brushing motion to change depending on the brushed location. These results also suggest that more detailed instructions might be required according to patient's oral condition.