Therapeutic Potential for Sphingolipids in Inflammatory Bowel Disease and Colorectal Cancer.

Inflammatory bowel disease (IBD), characterized by chronic inflammation in the intestinal tract, increases the risk for the development of colorectal cancer (CRC). Sphingolipids, which have been implicated in IBD and CRC, are a class of bioactive lipids that regulate cell signaling, differentiation, apoptosis, inflammation, and survival. The balance between ceramide (Cer), the central sphingolipid involved in apoptosis and differentiation, and sphingosine-1-phosphate (S1P), a potent signaling molecule involved in proliferation and inflammation, is vital for the maintenance of normal cellular function. Altered sphingolipid metabolism has been implicated in IBD and CRC, with many studies highlighting the importance of S1P in inflammatory signaling and pro-survival pathways. A myriad of sphingolipid analogues, inhibitors, and modulators have been developed to target the sphingolipid metabolic pathway. In this review, the efficacy and therapeutic potential for modulation of sphingolipid metabolism in IBD and CRC will be discussed.

A novel HSPB1S139F mouse model of Charcot-Marie-Tooth Disease.

Charcot-Marie-Tooth Disease (CMT) is a commonly inherited peripheral polyneuropathy. Clinical manifestations for this disease include symmetrical distal polyneuropathy, altered deep tendon reflexes, distal sensory loss, foot deformities, and gait abnormalities. Genetic mutations in heat shock proteins have been linked to CMT2. Specifically, mutations in the heat shock protein B1 (HSPB1) gene encoding for heat shock protein 27 (Hsp27) have been linked to CMT2F and distal hereditary motor and sensory neuropathy type 2B (dHMSN2B) subtype. The goal of the study was to examine the role of an endogenous mutation in HSPB1 in vivo and to define the effects of this mutation on motor function and pathology in a novel animal model. As sphingolipids have been implicated in hereditary and sensory neuropathies, we examined sphingolipid metabolism in central and peripheral nervous tissues in 3-month-old HspS139F mice. Though sphingolipid levels were not altered in sciatic nerves from HspS139F mice, ceramides and deoxyceramides, as well as sphingomyelins (SMs) were elevated in brain tissues from HspS139F mice. Histology was utilized to further characterize HspS139F mice. HspS139F mice exhibited no alterations to the expression and phosphorylation of neurofilaments, or in the expression of acetylated α-tubulin in the brain or sciatic nerve. Interestingly, HspS139F mice demonstrated cerebellar demyelination. Locomotor function, grip strength and gait were examined to define the role of HspS139F in the clinical phenotypes associated with CMT2F. Gait analysis revealed no differences between HspWT and HspS139F mice. However, both coordination and grip strength were decreased in 3-month-old HspS139F mice. Together these data suggest that the endogenous S139F mutation in HSPB1 may serve as a mouse model for hereditary and sensory neuropathies such as CMT2F.

Pelvic floor disorder assessment of knowledge and symptoms: an educational intervention for Spanish-speaking women (PAKS study).

INTRODUCTION AND HYPOTHESIS: Educational interventions have been effective in improving postpartum knowledge, performance of pelvic floor exercises, and bowel-specific quality-of-life. Our primary objective was to determine if a video-based educational intervention on pelvic floor disorders (PFDs) would increase Spanish-speaking women's knowledge of PFDs, and secondarily to assess if it would decrease pelvic floor symptoms. We hypothesized that Spanish-speaking women would improve their pelvic floor knowledge and symptoms post-intervention. METHODS: Inclusion criteria included women age 18 years and older and self-reported as a predominantly Spanish-speaker or equally bilingual English- and Spanish-speaker. Changes in knowledge were assessed with the Prolapse and Incontinence Knowledge Questionnaire (PIKQ). Changes in symptoms were assessed with the Pelvic Floor Distress Inventory-20 (PFDI-20). Linear regression assessed for independent effects. RESULTS: One hundred and fourteen women were enrolled and 112 completed the pre- and post-intervention PIKQ. Mean (standard deviation [SD]) age was 50 (14) years. Immediate post-intervention scores showed significant improvement in knowledge. Total PIKQ score improved by 5.1 (4.7) points (p < 0.001). POP subscore improved by 2.7 (2.7) points (p<0.001) and UI subscore improved by 2.3 (2.5) points (p < 0.001). Improvement in knowledge continued after four weeks (p < 0.001). PFDI-20 prolapse (p=0.02), colorectal-anal (p < 0.001) and urinary (p = 0.01) scores significantly improved only for the most symptomatic women at baseline. Using linear regression, total PIKQ (p = 0.03) and total PFDI-20 scores (p = 0.04) were associated with predominantly Spanish-speakers versus fully bilingual. CONCLUSION: Findings support the efficacy of a video-based educational intervention to improve knowledge of PFDs in Spanish-speaking women. The most symptomatic women benefitted from this intervention.

Creation and Implementation of Virtual Urogynecology Patient Cases for Medical Student Education.

Introduction: Urogynecologic disorders are highly prevalent, and many physicians across various specialties will encounter and care for patients with pelvic floor disorders. Yet most medical students have had limited to no experience in diagnosing and managing pelvic floor disorders, resulting in a gap in clinical education. Methods: Three virtual and interactive urogynecologic patient cases were developed on an e-learning platform with an overall goal of increasing clinical exposure to various pelvic floor disorders. The cases were integrated into the medical student obstetrics and gynecology clerkship during the 2020-2021 academic year (n = 40). Participants provided feedback regarding usability, acceptability, and educational value of the cases. Results: Twenty-one students (52%) completed the survey. Ninety percent (n = 19) agreed or strongly agreed that they were satisfied with the cases, and 71% (n = 15) agreed or strongly agreed that they would recommend the virtual patient cases to other students. All students (n = 21) felt that the format was easy to use and reported that the cases were appropriate for their level of learning. Most students felt that the cases increased or significantly increased their confidence regarding nonsurgical and surgical management options for pelvic floor disorders. Discussion: Our findings suggest that these interactive virtual patient cases are an acceptable, valuable, and effective tool for learners. Utilizing the cases can help mitigate existing disparities in exposure to pelvic floor disorders both highlighted by and preceding the COVID-19 pandemic.

Obstructed defecation syndrome in the first week after pelvic reconstructive surgery.

INTRODUCTION AND HYPOTHESIS: Research shows that patients are concerned about postoperative bowel function after pelvic reconstructive surgery. The objectives of this study were to estimate the proportion of patients with obstructed defecation syndrome (ODS), a subtype of constipation, in the week after surgery, to identify associated patient-level and perioperative characteristics and the associated bother. METHODS: Women completed a preoperative and postoperative ODS questionnaire and postoperative bowel diary. Characteristics of women with and without postoperative ODS were compared. Chi-squared or Fisher's exact tests compared categorical variables. Student's t test or Wilcoxon rank-sum tests compared continuous variables. Multivariate logistic regression was assessed for independent effects. Wilcoxon rank-sum tests compared the groups with regard to bother. Spearman correlation coefficients described the relationship among bother, postoperative ODS score, and bowel diary variables. RESULTS: Of the 186 participants enrolled, 165 completed the postoperative ODS questionnaire. Of these, 39 women (23.6%, 95% CI 17.2-30.1) had postoperative ODS. Postoperative ODS was significantly associated with preoperative ODS (p < 0.001), posterior colporrhaphy (p = 0.03), surgery type (p = 0.01), and longer duration of surgery (p = 0.03). Using multivariate logistic regression controlling for age, only preoperative ODS was significantly associated with postoperative ODS (OR 2.68, 95% CI 1.73-4.17). Women with postoperative ODS reported more bother with their defecatory symptoms (p < 0.001). The degree of bother was significantly associated with postoperative ODS score (p < 0.001). CONCLUSION: Using a validated disease-specific questionnaire to identify ODS, this complication was identified in 23.6% of patients in the week after pelvic reconstructive surgery. Preoperative ODS was a significant and important risk factor for this complication.

Validation of a Spanish Version of the Prolapse and Incontinence Knowledge Questionnaire.

OBJECTIVE: The objective of this study was to validate a Spanish version of the Prolapse and Incontinence Knowledge Questionnaire (PIKQ). METHODS: Validation and reliability testing of the Spanish version of the PIKQ was conducted in 2 phases. In the first phase, a translation-back-translation method by 6 bilingual researchers was utilized to generate a final Spanish translation. In the second phase, bilingual women were randomized to complete the Spanish or English version first, followed by the alternate language. Agreement between individual items from English and Spanish versions was assessed by percent agreement and κ statistics. Intraclass correlation coefficients compared overall PIKQ scores and pelvic organ prolapse (POP) and urinary incontinence (UI) subscores. To establish test-retest reliability, we calculated Pearson correlation coefficients. In order to have a precision of 10% for 90% agreement, so that the lower 95% confidence interval would not be less than 80% agreement, 50 bilingual participants were required. RESULTS: Fifty-seven bilingual women were randomized and completed both versions of the PIKQ. Individual items showed 74%-97% agreement, good to excellent agreement (κ = 0.6-0.89) for 9 items and moderate agreement (κ = 0.4-0.59) for 14 items between English and Spanish PIKQ versions. Intraclass correlation coefficients of the overall score and POP and UI subscores showed excellent agreement (intraclass correlation coefficient = 0.81-0.91). Pearson correlation coefficients between initial and repeat Spanish scores were high: overall (r = 0.87) and for POP (r = 0.81) and UI subscores (r = 0.77). CONCLUSIONS: A valid and reliable Spanish version of the PIKQ has been developed to assess patient knowledge about UI and POP.

Surgical Repair of the Genital Hiatus: A Narrative Review.

INTRODUCTION AND HYPOTHESIS: An enlarged genital hiatus (GH) is associated with the development of prolapse and may be associated with prolapse recurrence following surgery; however, there is insufficient evidence to support surgical reduction of the GH as prophylaxis against future prolapse. The objective of this review is (1) to review the association between GH size and pelvic organ prolapse and (2) to discuss the existing literature on surgical procedures that narrow the GH. METHODS: A literature search was performed in the PubMed search engine, using the keyword "genital hiatus." Articles were included if they addressed any of the following topics: (1) normative GH values; (2) associations between the GH and prolapse development or recurrence; (3) surgical alteration of the GH; (4) indications, risks or benefits of surgical alteration of the GH. RESULTS: An enlarging GH has been observed prior to the development of prolapse. Multiple studies show that an enlarged pre- and/or postoperative GH is associated with an increased risk of recurrent prolapse following prolapse repair surgery. There are limited data on the specific risks of GH alteration related to bowel and sexual function. CONCLUSIONS: GH size and prolapse appear to be strongly associated. Because GH size appears to be a risk factor for pelvic organ prolapse, the GH size should be carefully considered at the time of surgery. Surgeons should discuss with their patients the risks and potential benefits of additional procedures designed to reduce GH size.

Prevalence of stress urinary incontinence and intrinsic sphincter deficiency in patients with stage IV pelvic organ prolapse.

AIM: To determine the prevalence of stress urinary incontinence (SUI) and intrinsic sphincter deficiency (ISD) in women with stage IV pelvic organ prolapse. METHODS: Retrospective analysis of women with stage IV prolapse who underwent multichannel urodynamic testing. Abdominal leak point pressures (ALPP) and maximum urethral closure pressures (MUCP) were recorded. ISD was defined as ALPP ≤60 cm of water and/or MUCP ≤20 cm of water. Percentages were used to present the proportion of subjects diagnosed with SUI and ISD. RESULTS: A total of 145 patients met inclusion criteria. Mean age was 69 years; most patients were Caucasian (56%). Eighty-two (56%) patients were found to have SUI on urodynamic testing. Thirty-six (44%) of these were asymptomatic and identified as having occult SUI. Sixteen (19.5%) patients were diagnosed with ISD using ALPP and/or MUCP. Six (37%) of the ISD patients had at least one MUCP value ≤20 cm of water and 12 (75%) had observed leakage with at least one ALPP value ≤60 cm of water. The number of patients with leakage at ALPP ≤60 cm of water increased with increasing bladder volumes. Five ISD patients (31%) had ALPP ≤60 cm of water at 200 mL, six (37.5%) had ALPP ≤60 cm of water at 300 mL and seven (43.8%) had ALPP ≤60 cm of water at 400 mL. CONCLUSION: Greater than 50% of patients with stage IV pelvic organ prolapse had SUI on urodynamic testing, and 20% were found to have ISD. Of the patients diagnosed with SUI, 40% were asymptomatic. These findings may assist in counseling and preoperative planning for women with stage IV prolapse.

The role of the genital hiatus and prolapse symptom bother.

INTRODUCTION AND HYPOTHESIS: Pelvic organ prolapse (POP) severity is poorly correlated with prolapse symptoms. The objective of this study was to investigate the association between genital hiatus (GH) size and presence and severity of bulge symptoms. METHODS: This analysis utilized data from a longitudinal study of parous women. Women underwent annual assessment of POP, GH size, and bulge symptoms. "Bother" was scored by participants reporting bulge symptoms. Three analyses evaluated the association between GH size and bulge symptoms, each using linear mixed models. First, we compared case visits (bulge symptoms reported) to control visits (bulge symptoms never reported), matching for stage. Second, among women who reported bulge sensation at least once during the study, we compared GH size at visits with and without bulge symptoms. Third, among women who reported bulge sensation, we investigated whether GH size was associated with "bother" score, controlling for stage. RESULTS: Of 1528 women (7440 visits), 148 women (803 visits) reported bulge symptoms at ≥ 1 visit and 1380 women never reported bulge symptoms (6637 visits). Comparing 315 case visits (bulge symptoms reported) to 1260 control visits (bulge symptoms never reported), GH size was significantly greater among case visits (3.05 cm versus 2.85 cm, p ≤ 0.0001). In the case-crossover analysis, GH size was similar for visits with and without bulge symptoms (p = 0.63). When evaluating GH size and degree of bulge symptom bother, bother severity was significantly associated with GH size (p = 0.003). CONCLUSIONS: Independent of stage, GH size was significantly associated with prolapse bulge symptoms and bother severity.

A New Method for Extraction and Analysis of Ricin Samples through MALDI-TOF-MS/MS.

We report for the first time the efficient use of accelerated solvent extraction (ASE) for extraction of ricin to analytical purposes, followed by the combined use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and MALDI-TOF MS/MS method. That has provided a fast and unambiguous method of ricin identification for in real cases of forensic investigation of suspected samples. Additionally, MALDI-TOF MS was applied to characterize the presence and the toxic activity of ricin in irradiated samples. Samples containing ricin were subjected to ASE, irradiated with different dosages of gamma radiation, and analyzed by MALDI-TOF MS/MS for verification of the intact protein signal. For identification purposes, samples were previously subjected to SDS-PAGE, for purification and separation of the chains, followed by digestion with trypsin, and analysis by MALDI-TOF MS/MS. The results were confirmed by verification of the amino acid sequences of some selected peptides by MALDI-TOF MS/MS. The samples residual toxic activity was evaluated through incubation with a DNA substrate, to simulate the attack by ricin, followed by MALDI-TOF MS/MS analyses.

The conception of administrators regarding the formation of a healthcare consortium in Pernambuco, Brazil: a case study.

The formation of healthcare consortia is a management strategy adopted by a number of cities in Brazil in order to minimize the difficulties the population has in access to services of greater technological complexity. As administrators are the main governmental actors in the promotion of this strategy, the aim of the present study was to identify the motives, expectations and difficulties faced by the mayors, and secretaries of health that make up a healthcare consortium undergoing a formation process in the rural, coastal zone of the state of Pernambuco. A descriptive, qualitative, case study was conducted. Data collection was carried out through semi-structured interviews held with mayors and secretaries of health of the municipalities participating in the consortium. Data were analyzed by means of content analysis, using the NVivo 2.0 software program. The administrators cited difficulty in access to specialized services and the high cost of transporting patients to distant locations for treatment as motives for the formation of the consortium. With the implantation of this healthcare strategy, the expectations are a reduction in costs regarding patient transportation, an increase in access to services of greater complexity, and negotiations with other spheres of government. The main difficulties faced are political-partisan conflicts and excessive bureaucracy. Although there were no considerable divergences in the administrators' perceptions, it was evident that those who initiated the formation of the consortium offered a deeper, more detailed discourse, thereby demonstrating greater involvement when compared to those who offered continuity to the process.

Soybean toxin (SBTX), a protein from soybeans that inhibits the life cycle of plant and human pathogenic fungi.

Soybean toxin (SBTX) is a 44 kDa glycoprotein that is lethal to mice (LD(50) = 5.6 mg/kg). This study reports the toxicity of SBTX on pathogenic fungi and yeasts and the mechanism of its action. SBTX inhibited spore germination of Aspergillus niger and Penicillium herguei and was toxic to Candida albicans, Candida parapsilosis, Kluyveromyces marxiannus , Pichia membranifaciens, and Saccharomyces cerevisiae. In addition, SBTX hampered the growth of C. albicans and K. marxiannus and inhibited the glucose-stimulated acidification of the incubation medium by S. cerevisiae, suggesting that SBTX interferes with intracellular proton transport to the external medium. Moreover, SBTX caused cell-wall disruption, condensation/shrinkage of cytosol, pseudohyphae formation, and P. membranifaciens and C. parapsilosis cell death. SBTX is toxic to fungi at concentrations far below the dose lethal to mice and has potential in the design of new antifungal drugs or in the development of transgenic crops resistant to pathogens.

Prostaglandin E2 (PGE2) increases the number of rat bone marrow osteogenic stromal cells (BMSC) via binding the EP4 receptor, activating sphingosine kinase and inhibiting caspase activity.

Prostaglandin E(2) (PGE(2)) is bone-anabolic, i.e. stimulates bone formation and increases bone mass. In this study, we explored possible intracellular mechanisms of its increase of osteogenic cells in rat bone marrow. Adherent rat bone marrow cells were counted after 12-48 h or cultured for 21 days and mineralized nodules were counted. Also, apoptosis of marrow cells was measured after in vivo PGE(2) injection. PGE(2) (100 nM) increased 2-3 fold the number of adherent BMSC, an effect which was mediated via binding the EP(4) receptor since it was mimicked by forskolin and 11-deoxy-prostaglandin E(1) (PGE(1)) and was blocked by DDA and L-161982 (EP(4) antagonist). PGE(2) stimulated sphingosine kinase (SPK) activity since its effects were blocked by DMS (SPK inhibitor) and mimicked by SPP (SPK product). PGE(2) reduced the activity of caspase-3 and -8 in BMSC and their inhibitors increased BMSC number and nodule formation. In vivo, PGE(2) prevented the increase in the apoptosis of bone marrow cells caused by indomethacin. We propose that PGE(2) exerts an anti-apoptotic effect on BMSC, thereby increasing their number and subsequent osteoblastic differentiation. Such an effect could explain how PGE(2) stimulates bone formation in vivo.

In vitro effects of enamel matrix proteins on rat bone marrow cells and gingival fibroblasts.

Emdogain (EMD), a formulation of Enamel Matrix Proteins (EMP), is used clinically for periodontal regeneration, where it stimulates cementum formation and promotes gingival healing. In this study, we investigated the in vitro effects of EMD on rat bone marrow stromal cells (BMSC) and gingival fibroblasts (GF). EMD (at 25 micro g/mL) increased the osteogenic capacity of bone marrow, as evidenced by approximately three-fold increase in BMSC cell number and approximately two-fold increase in alkaline phosphatase (ALP) activity and mineralized nodule formation. The presence of EMD in the initial stages (first 48 hrs) of the culture was crucial for this effect. In contrast, EMD did not induce osteoblastic differentiation of GF (evidenced by lack of mineralization or ALP activity) but increased up to two-fold both their number and the amount of matrix produced. These in vitro data on BMSC and GF could explain the promotive effect of EMD on bone formation and connective tissue regeneration, respectively.

A selective EP4 receptor antagonist abrogates the stimulation of osteoblast recruitment from bone marrow stromal cells by prostaglandin E2 in vivo and in vitro.

Recent evidence indicates that systemic administration of PGE2 increases bone formation and bone mass via activation of the EP4 receptor. Previously, we demonstrated that osteoblastic recruitment from rat bone marrow stromal cells (BMSC) is a major mechanism for the anabolic effect of PGE2. In this study, we used a selective EP4 antagonist to test if the stimulation of osteoblast differentiation from rat BMSC in vitro and in vivo involves the EP4 receptor. In vitro, PGE2 (100 nM) increased nodule formation and alkaline phosphatase (ALP) activity in cultures of rat BMSC 1.5- to 2-fold. These effects were abolished by the EP4 antagonist at 10(-6) M but not 10(-9) M. Furthermore, PGE2 increased the number of surviving adherent BMSC by approximately 225% and the EP4 antagonist prevented this effect as well. The antagonist had no effect on basal levels of nodule formation and adherent cell number. In vivo, daily systemic administration of PGE2 at 6 mg/kg for 2 weeks increased cancellous bone area (by approximately 50%) and increased nodule formation (measured as mineralized area) in ex vivo stromal cultures by approximately 50%. Pre-administration of the EP4 antagonist at 10 mg/kg abrogated both the increase in bone mass as well as the increase in nodule formation. These data indicate that PGE2 stimulates osteoblastic commitment of BMSC via activation of the EP4 receptor.

Inhibition of cyclo-oxigenase-2 activity does not abolish the anabolic effect of prostaglandin E2 in vivo or in vitro.

It was previously reported that the expression of cyclo-oxigenase-2 (COX-2) is induced by prostaglandin E(2) (PGE(2)) in vitro in an osteogenic cell line and organ culture, suggesting an autoamplification mechanism. In this study, we first tested whether this phenomenon also occurs in bone tissue in vivo and found that a single anabolic dose of PGE(2) (5 mg/kg) induced (between 30 and 120 min) in rat tibiae, an increase in the mRNA level of COX-2 (2.5- to 9-fold) but not that of COX-1. Secondly, to test whether COX-2 activity in generating endogenous prostaglandins (PGs) is required for the in vivo anabolic properties of PGE(2), young male rats were injected daily with either vehicle (8% ethanol) or 5 mg/kg PGE(2) for 21 days. PGE(2)-injected rats received, 45 min prior to PGE(2), either dimethyl sulphoxide (as vehicle) or one of two doses of NS-398, a selective COX-2 inhibitor: a low dose (3 mg/kg) or a high dose (10 mg/kg). PGE(2) increased bone formation (measured as cancellous mineralizing surface, mineral apposition rate and bone formation rate) and bone mass (measured as cancellous bone area and surface and cortical width). None of these increases was suppressed by pre-administration of NS-398. In contrast, the high dose of NS-398 effectively suppressed an increase in rat hind-paw volume induced by a local carrageenan injection. Furthermore, since COX-2 inactivation may affect PG receptor expression, we found that pre-administration of NS-398 did not abolish the induction in EP(4) receptor mRNA levels, caused by PGE(2) in rat bone tissue. For in vitro testing, rat femoral bone marrow stromal cell cultures were initiated and were incubated in the absence or presence of PGE(2) at 100 nM (as an inducer) and with increasing concentrations of NS-398 (10(-8) M to 10(-5) M) for 21 days, after which time mineralized (Von-Kossa positive) nodules were counted. PGE(2) increased nodule formation as previously reported; however, NS-398 reduced nodule formation in both control and PGE(2)-treated cultures to the same extent. We conclude that while the level of COX-2 mRNA is increased in vivo by administration of PGE(2), inhibition of its activity (i.e. generation of endogenous PGs) does not abolish the anabolic effect of PGE(2).

Accuracy of a new apex locator: an in vitro study.

AIM: The purpose of this study was to test in an in vitro model the accuracy of a Bingo 1020 electronic apex locator, to compare the results to those of a well known apex locator, Root ZX, as well as to those of the radiographic method of tooth length determination. METHODOLOGY: A total of 120 extracted teeth, preserved in Thymol solution and kept refrigerated, was used for the study. The experiment was performed on single-rooted teeth and on one-root canal, chosen randomly, in multirooted teeth. The teeth were randomly divided into 12 groups of 10 teeth each. After access preparation, the actual length (AL) was measured. The teeth were embedded in an alginate model specially developed for testing apex locators. Electronic tooth length measurements (EL) were carried out prior to root canal preparation using the two electronic apex locators (EAL) - Root ZX and Bingo 1020; three measurements were taken and an average computed. After the third measurement, the file was left in the root canal and a periapical radiograph was taken. The radiographic length (RL) was recorded by measuring the file length from the coronal reference point to the tip of the file. Each root canal was then prepared to a no. 40 K-file diameter using a standardized technique; saline was used for irrigation. Upon completion of the root canal preparation, EL measurements were taken by each EAL in dry conditions and with different irrigation solutions. Each measurement was repeated three times. The RL was recorded according to the last EL measurement. Results were subjected to statistical analysis. RESULTS: In all parameters tested, a significant statistical difference was found between Bingo 1020 and the Root ZX. Measurements obtained using the Bingo 1020 were consistently closer to the AL (0.08 mm) than those obtained using the Root ZX. Both EALs measured the tooth length with great accuracy and a positive correlation of 0.76 (P = 0.00) existed between the two devices. No significant difference was found between the two apex locators when measurements were taken with the different irrigants (P = 0.34) and the content of the root canal did not affect the accuracy of the measurements. Lengths obtained by calculations from the radiographs were longer than the AL as well as the length obtained by both EALs (P = 0.00). CONCLUSIONS: The Bingo 1020 proved to be as reliable as Root ZX and was user friendly. Under the experimental conditions, electronic measurements were more reliable than radiographs in the process of root length determination.

Systemic prostaglandin E2 increases cancellous bone formation and mass in aging rats and stimulates their bone marrow osteogenic capacity in vivo and in vitro.

Prostaglandin E(2) (PGE(2)) has been shown to exert a bone anabolic effect in young and adult rats. In this study we tested whether it possesses a similar effect on bone formation and bone mass in aging rats. Fifteen-month-old rats were injected daily with either PGE(2) at 5 mg/kg or vehicle for 14 days. PGE(2) treatment stimulated the rate of cancellous bone formation (a approximately 5.5-fold increase in bone formation rate), measured by the incorporation of calcein into bone-forming surfaces at the tibial proximal metaphysis. This effect resulted in increased cancellous bone area (+54%) at the same site. Since PGE(2) treatment resulted in a much higher proportion of bone surface undergoing bone formation and thus lined with osteoblasts, we tested the hypothesis that PGE(2) stimulates osteoblast differentiation from bone marrow precursor cells both in vivo and in vitro. We found that ex vivo cultures of bone marrow stromal cells from rats injected for 2 weeks with PGE(2) at 5 mg/kg per day yielded more ( approximately 4-fold) mineralized nodules and exhibited a greater (by 30-40%) alkaline phosphatase activity compared with cultures from vehicle-injected rats, attesting to a stimulation of osteoblastic differentiation by PGE(2). We also compared the osteogenic capacity of bone marrow from aging (15-month-old) versus young (5-week-old) rats and its regulation by PGE(2) in vitro. Bone marrow stromal cell cultures from aging rats exhibited a greatly diminished osteogenic capacity, reflected in reduced nodule formation ( approximately 6% of young animals) and lower alkaline phosphatase activity ( approximately 60% of young animals). However, these parameters could be stimulated in both groups of animals by incubation with 10-100 nM PGE(2). The magnitude of this stimulation was greater in cultures from aging rats (+550% vs +70% in nodule formation of aging compared with young rats). In conclusion, we demonstrate here that PGE(2) exerts a bone anabolic effect in aging rats, similar to the effect we and others have reported in young, growing rats. The PGE(2)-stimulated bone formation, which augments bone mass, most likely results from recruitment of osteoblasts from their bone marrow stromal precursors.

In vitro viability, mitogenicity and clonogenic capacity of periodontal ligament cells after storage in six different media.

The choice of storage medium for preserving traumatically avulsed teeth is important for the success of future replantation. The objectives of this study were to evaluate the effectiveness of six different media: culture medium, alpha minimal essential medium (alpha-MEM), milk, Hank's balanced salt solution (HBSS), ViaSpan and conditioned medium (CM) to preserve cultured periodontal ligament fibroblasts (PDLF). Periodontal ligament fibroblasts were obtained from explants of human healthy extracted teeth. Plates with confluent PDLF were soaked in the various media for 2, 8 and 24 h at 4 degrees C. A control group was incubated with culture medium at 37 degrees C. After incubation, cell viability was determined by trypan blue exclusion test. Viable cells were then analyzed for mitogenic (with thymidine) and clonogenic capacity (by culturing one cell/well). Storage of PDLF up to 24 h decreased their vitality by only 2%-14%. Vitality of the PDLF after 2, 8 and 24 h was highest when stored in milk or HBSS (91%-97%) and lowest when stored in ViaSpan or CM (82%-93%). PDLF stored for 2-8 h in various media had a mitogenic capacity comparable to the control. However, increasing the storage period to 24 h decreased the mitogenicity of the cells by 3%-39%. The highest mitogenicity was found in PDLF stored in milk or HBSS and the lowest in CM or ViaSpan. The clonogenic capacity of the cells dropped by 38%-71% after 24 h and was the best indicator of the deteriorating effect of long storage. Milk and HBSS were the most effective in preserving the clonogenic capacity. Nevertheless, reduction in the viability, mitogenicity or clonogenic capacity was statistically significant in nearly all the tested media only after 24 h of incubation. In conclusion, HBSS and milk were the most effective media for preserving the viability, mitogenicity and clonogenic capacity after storage for up to 24 h at 4 degrees C.

Apical extent of rotary canal instrumentation with an apex-locating handpiece in vitro.

PROBLEM: The Tri Auto ZX (J. Morita Co., Kyoto, Japan) is a cordless endodontic handpiece with a built-in apex locator that is programmed to reverse the direction of rotation when the file reaches a predetermined apical level or when torque becomes excessive. OBJECTIVE: The purpose of this investigation was to examine the apical extent of rotary canal instrumentation and the ability to maintain apical constriction with the Tri Auto ZX at different automated settings. STUDY DESIGN: In 60 extracted teeth, canals were measured to the apical constriction, first visually and then electronically with the Tri Auto ZX; then they were instrumented with nickel titanium rotary files. For the instrumentation, the automatic apical reverse mechanism of the handpiece was set to 1, 1.5, or 2; these settings correspond to different distances from the apical foramen. Instrumentation was carried out apically until rotation was reversed by the automatic apical reverse function; the instrumented length was then measured, and the canal was filled with gutta-percha and sealer. The integrity of the apical constriction was assessed by exposing the apical 4 mm of the canal and observing the dentin-cementum junction. Paired t-tests were used to compare the visually measured length, the electronically measured length, and the instrumented length for each tooth. RESULTS: On average, the electronically measured length was 0.54 mm shorter than the visually measured length (p < 0.05). When the automatic apical reverse mechanism's setting was 1, the instrumented length was 0.1 mm shorter than the electronically measured length; when the setting was 1.5, the instrumented length was 0.36 mm shorter than the electronically measured length (p < 0.01). Results were inconsistent when the setting was 2. CONCLUSION: Instrumentation with the automatic apical reverse feature set at 1 consistently approximated the apical constriction; however, the constriction was frequently enlarged.