Role of supportive maintenance therapy on implant survival: a university-based 17 years retrospective analysis.

OBJECTIVE: The objective of this study was to determine whether professional maintenance appointments were related to a decrease on dental implant loss. METHODS: We performed a retrospective review (1995-2012) of 1020 patient dental charts to collect data including a cadre of different variables such as age, gender, race, diabetes, osteoporosis, jaw location, implant dimensions and professional maintenance therapy. As a patient may have multiple implants which are correlated, we selected one random implant per patient to assure independence of observations assumption of the Cox proportional hazards regression model. Data analysis was performed using Kaplan-Meier survival curves and multivariate analysis using Cox proportional hazards regression analysis. RESULTS: Our results demonstrate that subjects with no maintenance had the lowest cumulative survival rate as compared to subjects with regular maintenance. In a multivariate Cox regression model, regular maintenance patients had the dental implant failure rate reduced by 90% as compared to no maintenance (P = 0.001). If patients had less than one maintenance visit per year, the failure rate was reduced by 60% as compared to no maintenance, but the difference was not statistically significant (P = 0.08). CONCLUSION: From this research, we conclude that a professional administered periodontal maintenance at least on an annual basis is a critical factor for implant survival.

Prevalent congenital anomalies and metabolic disorders among live-born neonates in hospitals in General Santos City, Philippines (2009-2012)

OBJECTIVES: Birth defects are among the leading causes of infant mortality and morbidity in the Philippines. While affected infants make up a sizable portion of live births in General Santos City (GSC), no information is available about their actual numbers. This study aims to fill the knowledge gap about the prevalence and nature of congenital anomalies (CAs) and congenital metabolic disorders (CMDs) in the city from 2009 to 2012. METHODS: A retrospective study of in-patient records from six(6) medical facilities was done for CA/CMD cases from 2009-2012. Among the CMDs tested were congenital hypothyroidism (CH), congenital adrenal hyperlasia (CAH), galactosemia (GAL), hyperphenyalaninemia (HPA), phenylkentonuria  (PKU) and glucose-6-phosphate dehydrogenase deficiency (G6PD def). RESULT: Collected data revealed 109 cases of CAs with limb deformities, oro-facial clefting and neural tube disorders comprising majority of cases. There were 878 reported cases of CMDs with glucose-6-phosphate dehydrogenase deficiency (G6PD def) as the most prevalent at 829 cases. There was also a preponderance of CAs/CMDs in a government hospital for the indigent. CONCLUSION: These result underscore the emergence of CAs and CMDs as a major health problem among newborns in GSC. Higher incidences of birth defects in one district hospital also reveal a tentative link between CA/CMD incidence and socioeconomic status. It is of paramount importance therefore, to undertake expansion of the newborn screening program and to establish local birth registries so that a more comprehensive and realistic picture of CA/CMD prevalence in the city will be obtained.

Differentiation of human dental stem cells reveals a role for microRNA-218.

BACKGROUND: Regeneration of lost periodontium is the ultimate goal of periodontal therapy. Advances in tissue engineering have demonstrated the multilineage potential and plasticity of adult stem cells located in periodontal apparatus. However, it remains unclear how epigenetic mechanisms controlling signals determine tissue specification and cell lineage decisions. To date, no data are available on micro-RNA (miRNA) activity behind human-derived dental stem cells (DSCs). MATERIAL AND METHODS: In this study, we isolated periodontal ligament stem cells, dental pulp stem cells and gingival stem cells from extracted third molars; human bone marrow stem cells were used as a positive control. The expression of OCT4A and NANOG was confirmed in these undifferentiated cells. All cells were cultured under osteogenic inductive conditions and RUNX2 expression was analyzed as a marker of mineralized tissue differentiation. The miRNA expression profile was obtained at baseline and after osteogenic induction in all cell types. RESULTS: The expression of RUNX2 demonstrated successful osteogenic induction of all cell types, which was confirmed by alizarin red stain. The analysis of 765 miRNAs demonstrated a shift in miRNA expression that occurred in all four stem cell types, including a decrease in hsa-mir-218 across all differentiated cell populations. Hsa-mir-218 targets RUNX2 and decreases RUNX2 expression in undifferentiated human DSCs. DSC mineralized tissue type differentiation is associated with a decrease in hsa-mir-218 expression. CONCLUSION: These data reveal a miRNA-regulated pathway for the differentiation of human DSCs and a select network of human miRNAs that control DSC osteogenic differentiation.

Runx2, osx, and dspp in tooth development.

The transcription factors Runx2 and Osx are necessary for osteoblast and odontoblast differentiation, while Dspp is important for odontoblast differentiation. The relationship among Runx2, Osx, and Dspp during tooth and craniofacial bone development remains unknown. In this study, we hypothesized that the roles of Runx2 and Osx in the regulation of osteoblast and odontoblast lineages may be independent of one another. The results showed that Runx2 expression overlapped with Osx in dental and osteogenic mesenchyme from E12 to E16. At the later stages, from E18 to PN14, Runx2 and Osx expressions remained intense in alveolar bone osteoblasts. However, Runx2 expression was down-regulated, whereas Osx expression was clearly seen in odontoblasts. At later stages, Dspp transcription was weakly present in osteoblasts, but strong in odontoblasts where Osx was highly expressed. In mouse odontoblast-like cells, Osx overexpression increased Dspp transcription. Analysis of these data suggests differential biological functions of Runx2, Osx, and Dspp during odontogenesis and osteogenesis.

Isolation and characterization of multipotent human periodontal ligament stem cells.

BACKGROUND: Periodontal ligament (PDL) repair is thought to involve mesenchymal progenitor cells capable of forming fibroblasts, osteoblasts and cementoblasts. However, full characterization of PDL stem cell (SC) populations has not been achieved. OBJECTIVE: To isolate and characterize PDLSC and assess their capability to differentiate into bone, cartilage and adipose tissue. METHODS: Human PDL cells were stained for STRO-1, FACS sorted and expanded in culture. Human bone marrow SC (BMSC) served as a positive control. PDLSC and BMSC were cultured using standard conditions conducive for osteogenic, chondrogenic and adipogenic differentiation. Osteogenic induction was assayed using alizarine red S staining and expression of alkaline phosphatase (ALP) and bone sialoprotein (BSP). Adipogenic induction was assayed using Oil Red O staining and the expression of PPAR gamma 2 (early) and LPL (late) adipogenic markers. Chondrogenic induction was assayed by collagen type II expression and toluidine blue staining. RESULTS: Human PDL tissue contains about 27% STRO-1 positive cells with 3% strongly positive. In osteogenic cultures ALP was observed by day-7 in BMSC and day-14 in PDLSC. BSP expression was detectable by day-7; with more intense staining in PDLSC cultures. In adipogenic cultures both cell populations showed positive Oil Red O staining by day-25 with PPAR gamma 2 and LPL expression. By day-21, both BMSC and PDLSC chondrogenic induced cultures expressed collagen type II and glycosaminoglycans. CONCLUSIONS: The PDL contains SC that have the potential to differentiate into osteoblasts, chondrocytes and adipocytes, comparable with previously characterized BMSC. This adult PDLSC population can be utilized for potential therapeutic procedures related to PDL regeneration.

Phospholipase A2 activating protein (PLAA) is required for 1alpha,25(OH)2D3 signaling in growth plate chondrocytes.

Phospholipase A2 (PLA2) is pivotal in the rapid membrane-mediated actions of 1,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3]. Microarray analysis indicated that PLA2 activating protein (PLAA) mRNA is upregulated 6-fold before rat growth plate cells exhibit 1alpha,25(OH)2D3-dependent protein kinase C (PKC) increases, suggesting that it plays an important role in 1alpha,25(OH)2D3's mechanism of action. PLAA mRNA was confirmed in 1alpha,25(OH)2D3-responsive growth zone (prehypertrophic and upper hypertrophic cell zones) chondrocytes by RT-PCR and Northern blot in vitro and by in situ hybridization in vivo. PLAA protein was shown by Western blot and immunohistochemistry. PLAAs role in 1alpha,25(OH)2D3 signaling was evaluated in growth zone cell cultures using PLAA peptide. Arachidonic acid release was increased as was PLA2-specific activity in plasma membranes and matrix vesicles. PKCalpha, but not PKCbeta, PKCepsilon, or PKCzeta, was increased. PLAAs effect was comparable to that of 1alpha,25(OH)2D3 and was additive with 1alpha,25(OH)2D3. PLA2 inhibitors quinacrine and AACOCF3, and cyclooxygenase inhibitor indomethacin blocked the effect of PLAA peptide on PKC, indicating arachidonic acid and its metabolites were involved. This was confirmed using exogenous arachidonic acid. Prostaglandin acted via EP1 based on inhibition by SC19220 and not via EP2 since AH6809 had no effect. Like 1alpha,25(OH)2D3, PLAA peptide also increased activity of phospholipase C-specific activity via beta-1 and beta-3 isoforms, but not delta-1 or gamma-1; the effect of PLAA was via lysophospholipid but not via arachidonic acid. PLAA peptide decreased [3H]-thymidine incorporation to 50% of the decrease caused by 1alpha,25(OH)2D3. In contrast, PLAA peptide increased alkaline phosphatase-specific activity and proteoglycan production in a manner similar to 1alpha,25(OH)2D3. This indicates that PLAA is a specific activator of PLA2 in growth plate chondrocytes, and suggests that it mediates the membrane effect of 1alpha,25(OH)2D3, thereby modulating physiological response.

Lysophospholipid regulates release and activation of latent TGF-beta1 from chondrocyte extracellular matrix.

Transforming growth factor beta-1 (TGF-beta1) is released from the extracellular matrix of rat growth plate chondrocytes and activated by stromelysin-1 (matrix metalloproteinase 3, MMP-3), an enzyme that is stored in matrix vesicles. MMP-3 is released from these extracellular organelles by the direct action of 1alpha,25(OH)2D3 via activation of phospholipase A2 (PLA2), resulting in local production of lysophospholipids and matrix vesicle membrane destabilization. This effect of 1alpha,25(OH)2D3 is greater in matrix vesicles from growth zone chondrocyte cultures and PLA2 activity is higher in the growth zone in vivo, suggesting that it may depend on chondrocyte maturation state in the endochondral lineage. Previous studies have shown that latent TGF-beta1 can be activated by mild detergents in vitro, suggesting that lysophospholipids may act in vivo in a similar manner. To test this hypothesis, we determined if rat costochondral growth plate cartilage cells produce lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE) in a maturation state-dependent manner and if LPC or LPE could release and activate latent TGF-beta1 from the extracellular matrix produced by these cells. Rat growth plate chondrocytes produced both lysophospholipids, with growth zone cells producing higher levels of LPE via PLA1, and resting zone cells producing higher levels of LPC via PLA2. LPC and LPE directly increased activation of recombinant human latent TGF-beta1 in a biphasic manner with a peak at 2 microg/ml. Phosphatidylcholine, phosphatidylethanolamine, and LPE plasmalogen (LPEP), but not choline, also activated TGF-beta1. Latent TGF-beta1 incubated with LPC or LPE, but neither lysophospholipid alone, stimulated [3H]-thymidine incorporation of resting zone cells, indicating the TGF-beta1 released was biologically active. LPC and LPE also released TGF-beta1 in a dose- and time-dependent manner when incubated with cell-free extracellular matrices produced by the cells. These results indicate that LPC and LPE have important roles as regulators of rat growth plate chondrocytes by directly and indirectly activating TGF-beta1 stored in the extracellular matrix.

Rat costochondral chondrocytes produce 17beta-estradiol and regulate its production by 1alpha,25(OH)(2)D(3).

Prior studies have shown that 17beta-estradiol (17beta-E(2)) regulates growth plate chondrocyte maturation and differentiation. This study examines the hypothesis that 17beta-E(2) is a local regulator of rat costochondral growth plate chondrocytes by determining whether these cells express aromatase mRNA and enzyme activity, produce 17beta-E(2), and regulate 17beta-E(2) production by vitamin D(3) metabolites in a gender-specific and cell-maturation-dependent manner. Aromatase gene expression was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and northern analysis of total RNA from male and female chondrocytes. Aromatase specific activity was measured in cell layer lysates of confluent male and female rat costochondral resting zone (RC) and growth zone (GC) cartilage cells that had been treated for 24 h with 1alpha, 25(OH)(2)D(3), 24R,25(OH)(2)D(3), or transforming growth factor (TGF)-beta1. 17beta-E(2) released into the culture media of treated cells was measured by radioimmunoassay (RIA). Female RC cells expressed the highest levels of aromatase mRNA compared with male RC cells and both male and female GC cells. Aromatase activity was present in male and female cells and was 1.6 times greater in female RC cells than female GC cells; male RC and GC cells displayed comparable levels. All cultures produced 17beta-E(2), with a 2.5-fold greater production by female RC cells than female GC cells or either cell type from male rats. Treatment of cultures with 1alpha,25(OH)(2)D(3) caused a dose-dependent increase in 17beta-E(2) production by female RC (1.5-fold greater than control cells) and female GC (threefold greater than control cells) cells. In contrast, 1alpha,25(OH)(2)D(3) had no effect on male GC cells and increased production in male RC cells by only 10% at the highest concentration of 1alpha,25(OH)(2)D(3) used. Neither 24R, 25(OH)(2)D(3) nor TGF-beta1 had an effect on 17beta -E(2) production. These results support our hypothesis and indicate that 17beta-E(2) is most likely a local regulator of rat costochondral growth plate chondrocytes.

Dynamic SIMS ion microscopy imaging of intracellular boron accumulation from carboranyl nucleosides in glioma cells.

BACKGROUND: Selective accumulation of boron-10 isotope in the nuclei of cancer cells is pivotal to the success of Boron Neutron Capture Therapy (BNCT). Sophisticated microanalytical techniques are needed for checking the selectivity and boron delivery characteristics of experimental BNCT drugs. The present study employs a secondary ion mass spectrometry (SIMS) based subcellular isotopic imaging technique of ion microscopy for testing four carboranyl nucleosides. MATERIALS AND METHODS: CDU, HMCDU, CTU, and CFAU were tested for their boron delivery to the nuclear and cytoplasmic compartments of U251 human and F98 rat glioma cells. Quantitative SIMS analysis of boron was carried out in cryogenically prepared cells. RESULTS: For all drugs, the cell cytoplasm revealed significantly higher boron than the nucleus. However, the boron partitioning between the cell nucleus and the nutrient medium indicated 6.4-10.6 times higher boron in the nucleus. CONCLUSION: Carboranyl nucleosides studied here may provide efficient BNCT agents and need further evaluations of their efficacy.

Activation of latent transforming growth factor beta1 by stromelysin 1 in extracts of growth plate chondrocyte-derived matrix vesicles.

Previous studies have shown that matrix vesicles isolated from cultures of costochondral growth zone chondrocytes and treated with 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] can activate recombinant human latent transforming growth factor beta1 (rhTGF-beta1). It is unknown what enzyme or other factor in the extracellular organelles is responsible for the activation. This study tested the hypothesis that enzymes present in matrix vesicles can activate latent TGF-beta1 and that this is regulated by 1alpha,25(OH)2D3. To do this, we examined the ability of matrix vesicle extracts to activate small latent rhTGF-beta1. In addition, enzymes previously determined to be present in matrix vesicles were screened for their ability to activate small latent rhTGF-beta1. Recombinant human matrix metalloproteinase 2 (rhMMP-2; 72 kDa gelatinase), rhMMP-3 (stromelysin 1), purified human plasminogen, and purified urokinase (plasminogen activator) were each tested at varying concentrations. To assess the role of cell maturation, we used a cell culture model in which chondrocytes are derived from two distinct zones of rat costochondral cartilage, the resting zone and the growth zone. Matrix vesicles were isolated from these cultures and then tested. The results showed that extracts of matrix vesicles produced by both growth zone and resting zone chondrocytes were able to activate small latent rhTGF-beta1. The effects were dose and time dependent, with greater activity being found in extracts of matrix vesicles from the growth zone chondrocyte cultures. Only rhMMP-3 was able to activate small latent rhTGF-beta1, indicating that stromelysin-1, but not MMP-2, plasminogen, or urokinase, was involved. As observed in the extracts, the effect of rhMMP-3 was time and dose dependent. When anti-MMP-3 antibody was added to matrix vesicle extracts from both cell types, activation of small latent rhTGF-beta1 was dose-dependently blocked. Neither 1alpha,25(OH)2D3 nor 24R,25(OH)2D3 had a direct effect on activation of small latent rhTGF-beta1 by the extracts. However, when intact matrix vesicles were treated with 1alpha,25(OH)2D3, their ability to activate small latent rhTGF-beta1 was increased. Inhibition of phospholipase A2 with quinacrine blocked the 1alpha,25(OH)2D3-dependent effect. These results suggest that the ability of 1alpha,25(OH)2D3-treated matrix vesicles to activate small latent TGF-beta1 is via action of the secosteroid on the matrix vesicle membrane, not on the enzymes responsible for activating latent TGF-beta1. Because matrix vesicles isolated from growth zone chondrocytes have been shown to contain increased phospholipase A2 activity after treatment with 1alpha,25(OH)2D3, it is likely that this secosteroid promotes loss of membrane integrity through phospholipase A2-dependent formation of lysophospholipids, resulting in the release of MMP-3 into the matrix, where latent TGF-beta1 is stored. Taken together, the results of the current study show that matrix vesicles produced by growth plate chondrocytes contain MMP-3, that this enzyme is at least partially responsible for activation of small latent TGF-beta1 in the matrix, and that 1alpha,25(OH)2D3 regulates MMP release from matrix vesicles.

Ion microscopy in biology.

Ion microscopy, a mass spectrometry based isotopic imaging technique, is uniquely suited for ion transport related problems in biological systems. Due to its high sensitivity, it can image the transport and distribution of both major and minor elements (isotopes) at subcellular resolutions. The images of major elements such as K, Na, CI, etc., can be viewed directly and recorded in real-time from the microchannel plate-fluorescent screen detector of the instrument. The low concentration physiologically important elements, such as Ca, need about one minute of integration for good quality imaging. The isotopic imaging capability of ion microscopy provides a unique approach for the use of stable isotopes as tracers. In this way, one can image both the endogenous and the transported isotopes independently. Strict cryogenic sample preparations are essential for ion transport studies. Correlative imaging of the same cell with laser scanning confocal microscopy and ion microscopy can positively identify smaller cytoplasmic compartments such as the Golgi apparatus in calcium images. We have identified the Golgi apparatus as a calcium storing organelle. Another unique application of ion microscopy is the imaging of boron from boronated drugs used in Boron Neutron Capture Therapy (BNCT) of cancer. Ion microscopy is capable of rapid screening of potential drugs for BNCT. This critical information is essential for the fundamental understanding of BNCT. Ion microscopy is now at the stage where it can provide previously unattainable answers to important biomedical questions.

Intracellular boron localization and uptake in cell cultures using imaging secondary ion mass spectrometry (ion microscopy) for neutron capture therapy for cancer.

Quantitative ion microscopy of freeze-fractured, freeze-dried cultured cells is a technique for single cell and subcellular elemental analysis. This review describes the technique and its usefulness in determining the uptake and subcellular distribution of the boron from boron neutron capture therapy drugs.

CT of pneumoparotitis.

A case of clinically unsuspected pneumoparotitis diagnosed by CT is presented. The CT demonstration of air collections in the parotid gland and in the parotid ducts until their buccal orifices, as well as in the adjacent high-pressure buccal air pockets, determines the diagnosis.

Manometry and electromyography of the pharyngeal muscles in patients with dysphagia.

Simultaneous recording of the electromyographic activity of the pharyngeal muscles and the intraluminal pressure in the upper sphincter zone was performed routinely in patients with swallowing problems for the first time, to our knowledge. This technique was found to be very useful for the localization of the "site of lesion." The procedure is safe, easy to master, and causes minimal inconvenience. It can reveal, in the most direct way, whether the disturbance is in the hypopharyngeal musculature (represented by the inferior constrictor muscle), in the cricopharyngeal muscle (spasm or lack of relaxation), or in the synchronization between them. Simultaneous recording of intraluminal pressure adds valuable information about the mechanical events associated with electromyographic activity. It was found that in pathologic cases there is quite often no correlation between the electrical and mechanical events. Thus, simultaneous recording of both electrical and mechanical events is essential for the understanding of the pathophysiology of disturbances of deglutition.

Posttraumatic gustatory rhinorrhea.

We describe a case of gustatory rhinorrhea in which gustatory stimuli caused nasal obstruction and secretion simulating cerebrospinal rhinorrhea. This disorder was presumably caused by faulty regenerated parasympathetic nerve fibers reaching the nasal mucosa or, possibly, by a congenital condition. The characteristics of this disorder are compared with other autonomic disorders of the head and neck.

Electromyography of the inferior constrictor and cricopharyngeal muscles during swallowing.

Electromyography (EMG) of the inferior pharyngeal constrictor (IC) and the cricopharyngeal (CP) muscle was recorded in 18 patients with swallowing and/or aspiration problems who were candidates for cricopharyngeal myotomy. The EMG recordings were compared to those of 13 "normal" subjects who did not suffer from such problems. Differences in EMG activity between the control group and the patient group were considered with respect to the clinical symptoms in the patient group. Recording of EMG in the CP and IC muscles is relatively safe, useful, and easily mastered. The technique may provide important information regarding the function of some of the muscles involved in deglutition.

[Analysis of high frequency and low amplitude late potentials in the body surface electrocardiogram, in acute and chronic stages of ischemic cardiopathy]. / Análisis de los potenciales tardíos de alta frecuencia y baja amplitud del electrocardiograma de superficie, en las fases aguda y crónica de la cardiopatía isquémica.

A study to evaluate late potentials (LP) was carried out in 50 patients diagnosed as suffering from coronary heart disease. All the patients were divided into two groups: Group A, was made of 25 patients in the acute period of myocardial infarction, and group B, was made of other 25 patients in the chronic phase, with more of 3 months of evolution from the acute event. Average age in group A was 54.2 years, and 58.1 years in group B. Twenty normal volunteer subjects (group C) were also studied as a reference group. All the subjects in the 3 groups were in normal sinus rhythm, and no one of them showed bundle branch block in the basal ECG. Analysis of the vector magnitude was made for each point of the averaged wave, as the result of the mean root square of the addition of bipolar leads X, Y and Z, using a LP-3000 Fidelity Medical Inc. equipment, with a four poles Butterworth filter. LP were detected in 32% of the patients in group A, and in 56% of the group B (p less than 0.001). No LP was observed in patients of the group C. Concerning the localization of myocardial infarction, maximum CPK value, or Lown's grade of ventricular arrhythmias observed in coronary care unit, or in the 3rd week Holter monitoring, did not show significant statistical correlationship with the presence of LP in group A.(ABSTRACT TRUNCATED AT 250 WORDS)