Three-Dimensional Analysis of Enamel Crack Behavior Using Optical Coherence Tomography

The aim of this study was to nondestructively analyze enamel crack behavior on different areas of teeth using 3D swept source-optical coherence tomography (SS-OCT). Ten freshly extracted human teeth of each type on each arch ( n = 80 teeth) were inspected for enamel crack patterns on functional, contact and nonfunctional, or noncontact areas using 3D SS-OCT. The predominant crack pattern for each location on each specimen was noted and analyzed. The OCT observations were validated by direct observations of sectioned specimens under confocal laser scanning microscopy (CLSM). Cracks appeared as bright lines with SS-OCT, with 3 crack patterns identified: Type I - superficial horizontal cracks; Type II - vertically (occluso-gingival) oriented cracks; and Type III - hybrid or complicated cracks, a combination of a Type I and Type III cracks, which may or may not be confluent with each other. Type II cracks were predominant on noncontacting surfaces of incisors and canines and nonfunctional cusps of posterior teeth. Type I and III cracks were predominant on the contacting surfaces of incisors, cusps of canines, and functional cusps of posterior teeth. Cracks originating from the dental-enamel junction and enamel tufts, crack deflections, and the initiation of new cracks within the enamel (internal cracks) were observed as bright areas. CLSM observations corroborated the SS-OCT findings. We found that crack pattern, tooth type, and the location of the crack on the tooth exhibited a strong correlation. We show that the use of 3D SS-OCT permits for the nondestructive 3D imaging and analysis of enamel crack behavior in whole human teeth in vitro. 3D SS-OCT possesses potential for use in clinical studies for the analysis of enamel crack behavior.

Quality-of-life and performance status results from the phase III RAINBOW study of ramucirumab plus paclitaxel versus placebo plus paclitaxel in patients with previously treated gastric or gastroesophageal junction adenocarcinoma

BACKGROUND

The phase III RAINBOW trial demonstrated that the addition of ramucirumab to paclitaxel improved overall survival, progression-free survival, and tumor response rate in fluoropyrimidine-platinum previously treated patients with advanced gastric/gastroesophageal junction (GEJ) adenocarcinoma. Here, we present results from quality-of-life (QoL) and performance status (PS) analyses.

PATIENTS AND METHODS

Patients with Eastern Cooperative Oncology Group PS of 0/1 were randomized to receive ramucirumab (8 mg/kg i.v.) or placebo on days 1 and 15 of a 4-week cycle, with both arms receiving paclitaxel (80 mg/m(2)) on days 1, 8, and 15. Patient-reported outcomes were assessed with the QoL/health status questionnaires EORTC QLQ-C30 and EQ-5D at baseline and 6-week intervals. PS was assessed at baseline and day 1 of every cycle. Time to deterioration (TtD) in each QLQ-C30 scale was defined as randomization to first worsening of ≥10 points (on 100-point scale) and TtD in PS was defined as first worsening to ≥2. Hazard ratios (HRs) for treatment effect were estimated using stratified Cox proportional hazards models.

RESULTS

Of the 665 patients randomized, 650 (98%) provided baseline QLQ-C30 and EQ-5D data, and 560 (84%) also provided data from ≥1 postbaseline time point. Baseline scores for both instruments were similar between arms. Of the 15 QLQ-C30 scales, 14 had HR < 1, indicating similar or longer TtD in QoL for ramucirumab + paclitaxel. Treatment with ramucirumab + paclitaxel was also associated with a delay in TtD in PS to ≥2 (HR = 0.798, P = 0.0941). Alternate definitions of PS deterioration yielded similar results: PS ≥ 3 (HR = 0.656, P = 0.0508), deterioration by ≥1 PS level (HR = 0.802, P = 0.0444), and deterioration by ≥2 PS levels (HR = 0.608, P = 0.0063). EQ-5D scores were comparable between treatment arms, stable during treatment, and worsened at discontinuation.

CONCLUSION

In patients with previously treated advanced gastric/GEJ adenocarcinoma, addition of ramucirumab to paclitaxel prolonged overall survival while maintaining patient QoL with delayed symptom worsening and functional status deterioration.

CLINICALTRIALSGOV

NCT01170663.

Optimised paediatric CT dose at a tertiary children's hospital in Japan: a 4-y single-centre analysis

Since diagnostic reference levels (DRLs) for children are not currently established in Japan, the authors determined local DRLs for the full range of paediatric CT examinations in a single tertiary care children's hospital. A retrospective review of 4801 CT performance records for paediatric patients (<15 y old) who had undergone CT examinations from 2008 to 2011 was conducted. The most frequent examinations were of the head (52 %), followed by cardiac (15 %), temporal bone (9 %), abdomen (7 %), chest (6 %) and others (11 %). Approximately one-third of children received two or more CT scans. The authors' investigation showed that mean CTDIvol and DLP for head, chest and abdomen increased as a function of age. Benchmarking of the results showed that CTDIvol, DLP and effective dose for chest and abdomen examinations in this hospital were below average, whereas those for the head tended to be at or slightly above average of established DRL values from five countries. The results suggest that CT examinations as performed in a tertiary children's hospital in Japan are well optimised.

Improvement of spinal alignment and quality of life after corrective surgery for spinal kyphosis in patients with osteoporosis: a comparative study with non-operated patients

This study evaluated changes in spinal alignment and quality of life (QOL) after corrective spinal surgery for patients with postmenopausal osteoporosis and spinal kyphosis. Spinal global alignment and QOL were significantly improved after corrective spinal surgery but did not reach the level of non-operated controls.

INTRODUCTION

With the increased aging of society, the demand for corrective spinal instrumentation for spinal kyphosis in osteoporotic patients is increasing. However, previous studies have not focused on the improvement of quality of life (QOL) after corrective spinal surgery in patients with osteoporosis, compared to non-operated control patients. The purposes of this study were thus to evaluate changes in spinal alignment and QOL after corrective spinal instrumentation for patients with osteoporosis and spinal kyphosis and to compare these results with non-operated patients.

METHODS

Participants comprised 39 patients with postmenopausal osteoporosis ≥50 years old who underwent corrective spinal surgery using multilevel posterior lumbar interbody fusion (PLIF) for symptomatic thoracolumbar or lumbar kyphosis, and 82 age-matched patients with postmenopausal osteoporosis without prevalent vertebral fractures. Spinopelvic parameters were evaluated with standing lateral spine radiography, and QOL was evaluated with the Japanese Osteoporosis QOL Questionnaire (JOQOL), SF-36, and Roland-Morris Disability Questionnaire (RDQ).

RESULTS

Lumbar kyphosis angle, sagittal vertical axis, and pelvic tilt were significantly improved postoperatively. QOL evaluated with all three questionnaires also significantly improved after 6 months postoperatively, particularly in domain and subscale scores for pain and general/mental health. However, these radiographic parameters, total JOQOL score, SF-36 physical component summary score, and RDQ score were significantly inferior compared with non-operated controls.

CONCLUSIONS

The results indicate that spinal global alignment and QOL were significantly improved after corrective spinal surgery using multilevel PLIF for patients with osteoporosis and spinal kyphosis but did not reach the level of non-operated controls.

Abnormal cell proliferation in the p75NTR-positive basal cell compartment of the esophageal epithelium during squamous carcinogenesis

The low affinity neurotrophin receptor p75NTR is known to be expressed in the mitotically quiescent basal layer (BL) of the normal esophageal epithelium. The aim of the present study was to detect oncogenic changes in the p75NTR-positive BL during esophageal squamous carcinogenesis. The normal epithelium (NE), low-grade intraepithelial neoplasia (LGN), high-grade intraepithelial neoplasia (HGN), and esophageal squamous carcinoma (SCC), in which invasion was limited to the muscularis mucosa, were obtained from surgically removed esophagi. The expression of p75NTR, the proliferation marker ki67, hTERT, p53, and p63 was examined immunohistochemically. The expression of p75NTR was detected in these tissues with average staining indexes (number of stained cells/100 nucleated cells; SI) of 1.00, 0.99, 0.81, and 0.73, respectively. The expression of ki67 in the BL significantly increased with the progression from LGN to HGN. The expression of hTERT and p53 significantly increased with the progression from NE to LGN, and then increased in a stepwise manner in HGN and SCC, with SI (hTERT/p53) of 0.10/0.11, 0.32/0.45, 0.50/0.72, and 0.65/0.61, respectively. The expression of p63 showed no significant difference among NE, LGN, HGN, and SCC, with SI of 0.82, 0.77, 0.85, and 0.87, respectively. A correlation was observed between the expression of ki67 and p53 (P = 0.005), while a negative correlation was found between p75NTR and hTERT (P = 0.01). Our results demonstrated that phenotypic changes from quiescent to active proliferation in the p75NTR-positive BL occurred during the progression from LGN to HGN. The altered expression of hTERT and p53 in the BL was detected in LGN, which suggested that additional oncogenic events that disrupt mitotic regulation in the p75NTR-positive quiescent BL may play a crucial role in malignant transformation. Further investigations using the isolation and tracing of p75NTR-positive cells in precancerous epithelia may provide us with a better understanding of squamous carcinogenesis.

Cloning and expression of 3-deoxy-d-manno-oct-2-ulosonic acid α-ketoside hydrolase from oyster hepatopancreas†

We have previously reported that oyster hepatopancreas contained three unusual α-ketoside hydrolases: (i) a 3-deoxy-d-manno-oct-2-ulosonic acid α-ketoside hydrolase (α-Kdo-ase), (ii) a 3-deoxy-D-glycero-D-galacto-non-2-ulosonic acid α-ketoside hydrolase and (iii) a bifunctional ketoside hydrolase capable of cleaving both the α-ketosides of Kdn and Neu5Ac (Kdn-sialidase). After completing the purification of Kdn-sialidase, we proceeded to clone the gene encoding this enzyme. Unexpectedly, we found that instead of expressing Kdn-sialidase, our cloned gene expressed α-Kdo-ase activity. The full-length gene, consisting of 1176-bp (392 amino acids, Mr 44,604), expressed an active recombinant α-Kdo-ase (R-α-Kdo-ase) in yeast and CHO-S cells, but not in various Escherichia coli strains. The deduced amino acid sequence contains two Asp boxes (S(277)PDDGKTW and S(328)TDQGKTW) commonly found in sialidases, but is devoid of the signature FRIP-motif of sialidase. The R-α-Kdo-ase effectively hydrolyzed the Kdo in the core-oligosaccharide of the structurally defined lipopolysaccharide (LPS), Re-LPS (Kdo(2)-Lipid A) from Salmonella minnesota R595 and E. coli D31m4. However, Rd-LPS from S. minnesota R7 that contained an extra outer core phosphorylated heptose was only slowly hydrolyzed. The complex type LPS from Neisseria meningitides A1 and M992 that contained extra 5-6 sugar units at the outer core were refractory to R-α-Kdo-ase. This R-α-Kdo-ase should become useful for studying the structure and function of Kdo-containing glycans.

Percutaneous radiofrequency ablation for hepatocellular carcinoma located in the caudate lobe of the liver

AIM

This study aimed to evaluate the effectiveness and safety of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) located in the caudate lobe of the liver.

PATIENTS AND METHODS

Between 2012 April and 2014 February, 142 patients with HCC meeting the Milan criteria were enrolled in this study. Of these patients, nine patients had HCC located in the caudate lobe (caudate group). Six of the nine cases were located in the Spiegel lobe, two cases were located in the paracaval portion and one case was located in the caudate process. We evaluated the local recurrence rate and RFA-related complications in the caudate group and non-caudate group.

RESULTS

The local recurrence rate in the caudate group was 12.5% at 1 year and 12.5% at 2 years, while the local recurrence rate in the non-caudate group was 14.9% at 1 year and 29.0% at 2 years; there were no significant differences between the groups. No complications were observed in the caudate group, and minor complications were observed in six patients (4.5%) in the non-caudate group. No major complications or mortalities were observed in either group, and the complication rates were not significantly different between the groups (P = 1).

CONCLUSIONS

RFA for HCC in the caudate lobe and the non-caudate lobe has equivalent effectiveness and safety. RFA is a promising treatment option for HCC arising in the caudate lobe.

Microgaps and Demineralization Progress around Composite Restorations

This study investigated the influence of adhesives and marginal sealing on demineralization progress using optical coherence tomography (OCT). Cavities (4 × 2 mm) were prepared in bovine incisors and restored using Clearfil SE Protect (SP), Bond Force (BF), Scotchbond Universal (SB), or G-Bond Plus (GB), followed by Estelite Flow Quick flowable composite. The control group received no adhesive (n = 10). After 3-d incubation in artificial saliva and 10,000 thermal cycles, gaps at enamel and dentin margins were measured at 8 locations on cross-sectional images obtained from each restoration using swept-source OCT at 1310-nm wavelength. Specimens were demineralized using acidified gel (pH = 4.5) for 5 wk and scanned every week to monitor the lesion progress at the same marginal locations. Repeated-measures analysis of variance showed that demineralization period and adhesive type and their interaction had a significant effect on the lesion size in both substrates (P < 0.001). SP, BF, and SB had significantly lower enamel and dentin initial gaps than the control and GB (P < 0.05). Enamel lesion progress was slower in the fluoride-releasing adhesives SP and BF and significantly different from SB, GB, and the control (P < 0.001). SP and BF dentin lesions were significantly different from GB and the control (P < 0.001), but not from SB (P > 0.05). A significant positive correlation (P < 0.05) was found between initial gap length and formed lesion size in both substrates, which was stronger in enamel (r = 0.63) than dentin (r = 0.35). Microgaps forming at the margins of restorations depend on adhesives and significantly contribute to the progress of demineralization around the margins, while fluoride release may decrease the rate of progression.

The AURKA/TPX2 axis drives colon tumorigenesis cooperatively with MYC

BACKGROUND

The MYC oncogene has long been established as a central driver in many types of human cancers including colorectal cancer. However, the realization of MYC-targeting therapies remains elusive; as a result, synthetic lethal therapeutic approaches are alternatively being explored. A synthetic lethal therapeutic approach aims to kill MYC-driven tumors by targeting a certain co-regulator on the MYC pathway.

PATIENTS AND METHODS

We analyzed copy number and expression profiles from 130 colorectal cancer tumors together with publicly available datasets to identify co-regulators on the MYC pathway. Candidates were functionally tested by in vitro assays using colorectal cancer and normal fibroblast cell lines. Additionally, survival analyses were carried out on another 159 colorectal cancer patients and public datasets.

RESULTS

Our in silico screening identified two MYC co-regulator candidates, AURKA and TPX2, which are interacting mitotic regulators located on chromosome 20q. We found the two candidates showed frequent co-amplification with the MYC locus while expression levels of MYC and the two genes were positively correlated with those of MYC downstream target genes across multiple cancer types. In vitro, the aberrant expression of MYC, AURKA and TPX2 resulted in more aggressive anchorage-independent growth in normal fibroblast cells. Furthermore, knockdown of AURKA or TPX2, or treatment with an AURKA-specific inhibitor effectively suppressed the proliferation of MYC-expressing colorectal cancer cells. Additionally, combined high expression of MYC, AURKA and TPX2 proved to be a poor prognostic indicator of colorectal cancer patient survival.

CONCLUSIONS

Through bioinformatic analyses and experiments, we proposed TPX2 and AURKA as novel co-regulators on the MYC pathway. Inhibiting the AURKA/TPX2 axis would be a novel synthetic lethal therapeutic approach for MYC-driven cancers.

Type 2 diabetes reduces the proliferation and survival of oligodendrocyte progenitor cells in ishchemic white matter lesions

Diabetes mellitus (DM) is a major risk factor for stroke and it exacerbates tissue damage after ischemic insult. Diabetes is one of the important causes of the progression of white matter lesion, however, the pathological mechanisms remain unclear. The present study evaluated the influences of type 2 DM on ischemic subcortical white matter injury and the recruitment of oligodendrocyte progenitor cells (OPCs) under chronic cerebral hypoperfusion using type 2 diabetic (db/db) mice. After bilateral common carotid artery stenosis (BCAS), the rarefaction in the white matter was more severe in db/db mice than in db/+ mice, and the number of glutathione S-transferase-pi (GST-pi)-positive mature oligodendrocytes (OLG) was lower in db/db mice than in db/+ mice at 4 and 8 weeks after ischemia. There were no significant differences in the number of single-stranded DNA (ssDNA)-positive apoptotic cells in the deep white matter between the db/db and db/+ mice. We found a transient increase in the platelet-derived growth factor receptor-α (PDGFRα)-positive OPCs in white matter lesions after ischemia. However, significantly fewer PDGFRα-positive OPCs were detected in db/db than db/+ mice from 4weeks after BCAS. The number of Ki67-positive proliferating cells in the deep white matter was significantly lower in db/db mice than in db/+ mice from 4 to 8weeks after BCAS. Most of the Ki67-positive cells were PDGFRα-positive OPCs. Finally, we assessed the survival of 5-bromo-2'-deoxyuridine (BrdU)-positive proliferating cells in ischemic white matter, and found significantly poorer survival of BrdU/PDGFRα-positive OPCs or BrdU/GST-pi-positive OLGs in the db/db mice compared to the db/+ mice in the white matter after BCAS. Our findings suggest that the type 2 DM mice exhibited more severe white matter injury 8 weeks after chronic ischemia. Decreased proliferation and survival of OPCs may play an important role in the progression of white matter lesions after ischemia in diabetics.

Difference in efficacy of proton pump inhibitor between new-onset and recurrent gastroesophageal reflux disease: Result from a study of on-demand versus continuous maintenance therapy in Japan

BACKGROUND-OBJECTIVE

No study has focused on the difference in efficacy of maintenance therapy between patients with new-onset and recurrent gastroesophageal reflux disease (GERD). The aim of this study is to reveal this point.

METHODS

Endoscopically proven GERD patients who had completed 8-week initial therapy were sequentially randomized to continuous arm (Omeprazole 20mg od) or on-demand arm (Omeprazole 20mg on-demand). Patients filled in daily symptoms and tablet usages for 24 weeks. Patients underwent upper GI endoscopy at 24 weeks. Symptom relief was defined as no symptoms for>6 days during a week. The numbers of patients who achieved symptom relief and mucosal healing were compared between the new-onset and recurrent groups in the continuous arm and in the on-demand arm, respectively.

RESULTS

Among new-onset GERD [n=82 (continuous: 42 patients, on-demand: 40)], continuous arm achieved significant symptom-relief than in on-demand arm at 4*,5*,6** and 17*week. Among recurrent GERD [n=36(continuous: 17 patients, on-demand: 19)], continuous arm achieved significant symptom-relief at 1**,2*,3*,4*,5**,7**,8**,17* and 18* week, respectively (*<0.05,**<0.01). The number of healed patients was significantly higher in new-onset group (60/68, 88.2%) than in recurrent group (17/30, 56.7%) (<0.01).

CONCLUSION

Since therapeutic response during maintenance therapy was poor in recurrent GERD, continuous therapy is recommended in order to maintain symptom-relief and mucosal healing. Hippokratia 2015, 19 (1): 53-56.

α-N-Acetylglucosaminidase from Bifidobacterium bifidum specifically hydrolyzes α-linked N-acetylglucosamine at nonreducing terminus of O-glycan on gastric mucin

α-Linked N-acetylglucosamine is one of the major glyco-epitopes in O-glycan of gastroduodenal mucin. Here, we identified glycoside hydrolase (GH) family 89 α-N-acetylglucosaminidase, termed AgnB, from Bifidobacterium bifidum JCM 1254, which is essentially specific to GlcNAcα1-4Gal structure. AgnB is a membrane-anchored extracellular enzyme consisting of a GH89 domain and four carbohydrate-binding module (CBM) 32 domains. Among four CBM32 domains, three tandem ones at C-terminus showed to bind porcine gastric mucin, suggesting that these domains enhance the enzyme activity by increasing affinity for multivalent substrates. AgnB might be important for assimilation of gastroduodenal mucin by B. bifidum and also applicable to production of prebiotic oligosaccharides from porcine gastric mucin.