Comparison of in vivo and in vitro force decay of elastomeric chains/modules: a systematic review and meta analysis

BACKGROUND

The study evaluated and compared the force decay of orthodontic elastomeric chains/modules in both in vivo and in vitro settings.

METHODS

A protocol in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was formulated and registered with the International Prospective Register of Systematic Reviews. A total of 53 articles (44 in vitro and 9 in vivo studies) found via search of the electronic databases of Cochrane and the National Library of Medicine (MEDLINE; PubMed), and manual search of the gray literature from institutional library resources, were selected. Data extraction, quality analysis, risk of bias assessment, and meta-analysis of the level of force decay of elastomeric chains/modules were conducted per standard protocol, and suitable statistical analyses were applied.

RESULTS

The mean force decay in the in vivo setting was 41.9% at 24 hours, 42.6% after 1 week, 46.8% after 2 weeks, and 55.0% after 3 weeks. Similarly, the force decay in the in vitro studies was 38.9% at 24 hours, 42.1% after 1 week, 44.6% after 2 weeks, and 51.1% after 3 weeks. However, at the 95% confidence interval, the force decay rates of in vivo and in vitro studies overlap, with a statistically insignificant difference in force decay observed in the in vivo and in vitro settings.

CONCLUSIONS

This systematic review and meta-analysis observed more force decay in the in vivo studies versus the in vitro studies (although this difference was statistically insignificant), with the maximum force decay occurring during the initial days, with a reduction to approximately 50% within 3 weeks. Hence, change of the elastomeric chains/module, at intervals of 3 weeks, is advised. (PROSPERO registration no. CRD42020209535).

Abstract AP22: DNA DAMAGE RESPONSES AND IMMUNE PROFILING THROUGH HIGHLY MULTIPLEXED TISSUE IMMUNOFLUORESCENCE (T-CYCIF) IN HIGH-GRADE SEROUS OVARIAN CANCER

INTRODUCTION: Immune checkpoint blockade (ICB) has emerged as a new therapeutic approach for multiple cancers, however, the responses to single-agent ICBs have been modest in high-grade serous ovarian cancer (HGSOC). Preclinical and early clinical data indicate promising efficacy of combination with DNA damaging agents and immunotherapy, however lack of functional- and tissue geographical knowledge on the interplay between DNA repair and immune activation has hampered the future development of these strategies. The majority of HGSOC are deficient in homologous recombination (HR) DNA repair, and this deficiency is associated with increased immune recognition and potentially increased response to ICBs. Compelling evidence has shown that DNA damaging agents increase the expression of immune-regulatory genes, such as interferons, which can potentially overcome resistance to ICB. There is a critical need for a deeper understanding of the dynamics between DNA damage in cancer cells and anti-tumor immune responses in HGSOC in order to find rational combinations and predictive biomarkers for DNA damaging agents and immunotherapy.

RESULTS: We are employing a novel, high-multiplex tissue cyclic immunofluorescence (t-CycIF) platform allowing for the simultaneous detection of up to 60 different antigens at single cell resolution. To reveal the effects of between intrinsic and treatment-induced DNA damage in HGSOC, we are profiling the microenvironments in HGSOCs with inherent DNA repair deficiencies, and after DNA damaging therapy. We collected clinically annotated cohorts of 37 BRCA1/2 mutated and 17 HR wild-type patients (Strickland et al, 2016), as well as six paired pre- and post-treatment and 18 post-treatment tumor samples from patients undergoing neoadjuvant chemotherapy (NACT). Using image analysis we generated highly multiplexed single cell data for over 106 cells. Through supervised clustering, we evidenced distinct cell compositions in the tumor microenvironment of BRCA1/2 mutated and HR-wild type HGSOCs. Consistent with the role of immune-suppression in HGSOC progression, we found that high infiltration of CD4/FOXP3+ regulatory T-cells associated with more actively proliferating cancer cells. Interestingly, tumors with high expression of PD1/PD-L1 were found to have high infiltration of CD1c+ dendritic cells potentially indicating active suppression of antigen presenting pathways in these tumors. Further, tumors with high levels of DNA damage show active interferon signaling, which associated with significantly higher CD8+ cytotoxic T-cell infiltration. In addition, our preliminary evidence suggests heterogenous DNA damage response- and immune profiles in samples collected after NACT.

CONCLUSIONS: BRCA1/2 mutated tumors have a distinct microenvironment compared to HR-wt HGSOC. In support of earlier findings, FOXP3+ T-cells contribute to immune suppression in HGSOC. The high infiltration of dendritic cells and PD1/PD-L1 expression indicates a subgroup of HGSOC that are likely sensitive to ICBs. Further, increased DNA damage and interferon pathway activation delineated a more immunogenic subset of HGSOC. We conclude that t-CycIF could accelerate the development of rational strategies for combining DNA damaging agents with immunotherapy to ultimately improve the treatment and outcomes of patients with ovarian cancer.

Citation Format: Anniina Färkkilä, Jia-Ren Lin, Zoltan Maliga, Sameer S. Chopra, Bose Koruchupakkal, Brooke E. Howitt, Kyle C. Strickland, Sandro Santagata, Elizabeth M. Swisher, Ursula A. Matulonis, Jennifer. L. Guerriero, Kevin Elias, Panagiotis Konstantinopoulos, Peter K. Sorger, and Alan D. D'Andrea. DNA DAMAGE RESPONSES AND IMMUNE PROFILING THROUGH HIGHLY MULTIPLEXED TISSUE IMMUNOFLUORESCENCE (T-CYCIF) IN HIGH-GRADE SEROUS OVARIAN CANCER [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr AP22.

Abstract 139: DNA damage and immunoprofiling with highly multiplexed tissue immunofluorescence (t-CycIF) in high-grade serous ovarian cancer

Immune checkpoint blockade (ICB) has emerged as a new promising therapeutic approach in multiple cancers, however, the responses to single-agent ICBs have been modest in high-grade serous ovarian cancer (HGSOC). Preclinical- and early clinical data show promising efficacy of combining DNA damaging agents with immunotherapy. An improved understanding of the interplay between DNA damage in cancer cells and anti-tumor immune responses may therefore accelerate the development of rational drug combinations and identify predictive biomarkers. The majority of HGSOC are deficient in homologous recombination (HR) DNA repair, and use alternative, error-prone DNA repair pathways, that have been shown to be associated with increased immune recognition (Strickland et al, 2016). Compelling evidence has shown that DNA damaging agents increase the expression of immune-regulatory genes, such as MCH class I antigens, and interferons in HR deficient tumors. Further, HR deficient tumor exhibit an increased response to ICBs, and DNA damage-driven activation of interferon signalling has been shown to overcome resistance to ICBs (Wang et al, 2016). To reveal the relationship between intrinsic and treatment-induced DNA damage and the HGSOC immune microenvironment we are employing a novel, high-multiplex tissue cyclic immunofluorescence (t-CycIF) platform (Lin et al, 2016& 2017) allowing for the simultaneous detection of up to 60 different antigens at single cell resolution. Utilizing t-CycIF we are in the process of profiling the DNA damage and immune responses in three unique HGSOC clinical cohorts including i) tumors with inherent DNA repair deficiencies ii) pre- and post DNA damaging therapy iii) tumors collected in an innovative clinical trial combining Poly- ADP Ribose Polymerase inhibitor (PARPi) Niraparib and ICB Pembrolizumab. Using this high-dimensional, quantitative data we are mapping the abundance, spatial arrangement and functional state of cancer cells, immune cells, and stroma in the HGSOC microenvironment. The highly multiplexed t-CycIF data are processed with established computational algorithms and correlated with clinical outcomes. Our preliminary data shows that t-CycIF sensitively captures immune cell subpopulations, tumor heterogeneity and DNA damage in HGSOC. We anticipate that t-CycIF could accelerate the development of rational strategies for combining DNA damaging agents with immunotherapy to ultimately improve the treatment and outcomes of patients with ovarian cancer.

Citation Format: Anniina Farkkila, Sameer S. Chopra, Jia-Ren Lin, Zoltan Maliga, Bose Koruchupakkal, Kyle C. Strickland, Brooke E. Howitt, Sandro Santagata, Ursula A. Matulonis, Kevin Elias, Elizabeth M. Swisher, Panagiotis A. Konstantinopoulos, Peter Sorger, Alan D. D'Andrea. DNA damage and immunoprofiling with highly multiplexed tissue immunofluorescence (t-CycIF) in high-grade serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 139.

Effect of retraction of anterior teeth on pharyngeal airway and hyoid bone position in Class I bimaxillary dentoalveolar protrusion

BACKGROUND

To test the hypothesis that the retraction of anterior teeth has no effect on the dimensions of pharyngeal airway and to evaluate the retraction of anterior teeth on each parameter of pharyngeal airway.

METHODS

Twenty-two adult patients of Class I bimaxillary protrusion requiring first premolar extractions with maximum anchorage requirements were selected. The pharyngeal airway and dentofacial parameters of the patients were compared using pre- and post-treatment lateral cephalograms with the help of Student's paired t-test (P < 0.05). The relationship between airway size and dentofacial parameters was also evaluated using Pearson correlation coefficient.

RESULTS

The upper and lower lips were retracted by 2.25 and 5.4 mm after retraction of the incisors. The tips of upper and lower incisors were retracted by 7.75 and 7.15 mm, respectively. There was a statistically significant decrease in SPP-SPPW (P < 0.05), U-MPW (P < 0.001), TB-TPPW (P < 0.001), and change in HRGN (P < 0.01). A significant correlation was observed between the amount of retraction of lower incisor and decrease in the pharyngeal airway posterior to soft palate (r = 0.102), tongue (r = 0.322), and change in HRGN (r = 0.265).

CONCLUSIONS

The size of the pharyngeal (velopharyngeal and glossopharyngeal) airway reduced and hyoid bone position changed after retraction of the incisors in extraction space in bimaxillary protrusive adult patients.

Management of Tooth Size Arch Size Discrepancy (TSASD) in Patients with Sleep Disorder Breathing

This case report describes the interdisciplinary management of an adult patient with sleep disorder breathing i.e. snoring. Treatment involved combined ortho-surgical management. Marked improvement in general health, good esthetic results, and dental relationships were achieved by the treatment.

A radiographic study of external apical root resorption in patients treated with single-phase fixed orthodontic therapy

BACKGROUND

External apical root resorption (EARR) is one of the most common iatrogenic consequences of orthodontic tooth movement. Many factors like gender, duration, orthodontic force and duration of orthodontic treatment have been implicated to cause EARR.

METHODS

Pre- and post-treatment OPGs of 60 orthodontic patients (30 males and 30 females) who had undergone treatment with a single phase of fixed orthodontic therapy were randomly selected from institutional archives. The root apices were evaluated for EARR by a single operator on an radiograph viewing box at a standardized source of light using a four-grade ordinal scale. Anterior EARR was measured on the maxillary and mandibular canines. Posterior EARR was measured on premolars, mesiobuccal and distobuccal roots of maxillary first molars and mesial and distal roots of mandibular first molars. The results were compiled and subjected to statistical analysis.

RESULTS

The cases in which the patients underwent therapeutic extraction had a relatively higher amount of EARR compared to the cases in which the patients were treated by non-extraction therapy (P < 0.001). Odds ratio indicated that extraction cases had two-fold increased risk of EARR than non-extraction cases (P < 0.001). No statistically significant difference was observed in the distribution of EARR based on gender or duration of orthodontic treatment (P > 0.05).

CONCLUSION

Therapeutic extraction is an important determinant of post-treatment EARR. Gender and duration of orthodontic treatment may not be important variables in the causation of EARR according to the findings of this study. However, longitudinal studies with larger sample size are required to validate the results of this study.

Comparative evaluation of anchorage reinforcement between orthodontic implants and conventional anchorage in orthodontic management of bimaxillary dentoalveolar protrusion

BACKGROUND

Increased upper lip procumbency is commonly associated with maxillary dentoalveolar protrusion with the major goal of reducing maxillary dentoalveolar protrusion. The treatment plan usually includes extraction of the maxillary first premolars, followed by retraction of anterior teeth with maximum anchorage. Dental implants have been widely accepted as successful adjuncts for obtaining maximum anchorage in orthodontic treatment.

METHODS

50 subjects between the ages of 13 and 17 years having bimaxillary dentoalveolar protrusion were included in the study. The patients were divided into two groups. Both groups received treatment with 0.022″ MBT prescription preadjusted edgewise appliance system. In addition, subjects of Group 'I' received the Nance button and lingual arch as anchorage reinforcement in the upper and lower arches, respectively. Subjects of Group 'II' received self-drilling titanium OI for anchorage reinforcement.

RESULTS

Significant retraction was achieved in all cases with good vertical control. Anchor loss was observed in both groups. Anchor loss was much higher in Group I compared to Group II, and an intergroup comparison for anchor loss was highly significant.

CONCLUSION

Implants as anchorage, for en masse retraction, can be incorporated into orthodontic practice. The use of orthodontic implants for anchorage is a viable alternative to conventional molar anchorage.

Comparative evaluation of anchorage loss between self-ligating appliance and Conventional pre-adjusted edgewise appliance using sliding mechanics - A retrospective study

BACKGROUND

Although a number of studies have been undertaken to evaluate the friction characteristics of self-ligating brackets, there have been only few studies which have actually evaluated the clinical efficiency of these self-ligating brackets. This study was done to evaluate the clinical efficiency of Passive SLB (Smart Clip) in terms of anchorage loss and total treatment duration by comparing it with a Conventional pre-adjusted edgewise (M.B.T.) bracket system.

METHODS

This was a retrospective study in which the study sample comprised of ten patients treated with Passive SLB (Smart Clip, 0.022″) and ten patients treated with Conventional pre-adjusted edgewise (M.B.T.) bracket system (0.022″) who required therapeutic extraction of U/L first premolars as a part of their orthodontic treatment plan. Pretreatment and post treatment lateral cephalograms were taken to evaluate the amount of anchorage loss. The total time required to complete the treatment was also recorded.

RESULTS

Anchorage loss observed with Passive SLB (Smart Clip) sagittally was 1.90 ± 0.68 mm in the maxilla and 1.90 ± 0.43 mm in the mandible and vertically was 0.52 ± 0.53 mm in the maxilla and 0.70 ± 0.69 mm in the mandible. Anchorage loss observed with Conventional pre-adjusted edgewise (M.B.T.) bracket system sagittally was 2.08 ± 0.43 mm in the maxilla and 1.95 ± 0.44 mm in the mandible and vertically was 0.50 ± 0.49 mm in the maxilla and 0.68 ± 0.53 mm in the mandible. The average time taken for the completion of treatment in Passive SLB (Smart Clip) and Conventional pre-adjusted edgewise (M.B.T.) bracket system was 14.0 ± 2.4 and 17.2 ± 2.6 months respectively.

CONCLUSION

There was no statistically significant difference in the quantum of anchor loss between Smart Clip self-ligating bracket system and Conventional pre-adjusted edgewise (M.B.T.) bracket system although Smart Clip self-ligating bracket system is efficient in reducing the overall treatment time.

Interdisciplinary Management of Patient with Advanced Periodontal Disease

This case report describes the interdisciplinary management of an adult patient with advanced periodontal disease. Treatment involved orthodontic and periodontal management. Good esthetic results and dental relationships were achieved by the treatment.

Inherited CHST11/MIR3922 deletion is associated with a novel recessive syndrome presenting with skeletal malformation and malignant lymphoproliferative disease

Glycosaminoglycans (GAGs) such as chondroitin are ubiquitous disaccharide carbohydrate chains that contribute to the formation and function of proteoglycans at the cell membrane and in the extracellular matrix. Although GAG-modifying enzymes are required for diverse cellular functions, the role of these proteins in human development and disease is less well understood. Here, we describe two sisters out of seven siblings affected by congenital limb malformation and malignant lymphoproliferative disease. Using Whole-Genome Sequencing (WGS), we identified in the proband deletion of a 55 kb region within chromosome 12q23 that encompasses part of CHST11 (encoding chondroitin-4-sulfotransferase 1) and an embedded microRNA (MIR3922). The deletion was homozygous in the proband but not in each of three unaffected siblings. Genotyping data from the 1000 Genomes Project suggest that deletions inclusive of both CHST11 and MIR3922 are rare events. Given that CHST11 deficiency causes severe chondrodysplasia in mice that is similar to human limb malformation, these results underscore the importance of chondroitin modification in normal skeletal development. Our findings also potentially reveal an unexpected role for CHST11 and/or MIR3922 as tumor suppressors whose disruption may contribute to malignant lymphoproliferative disease.

[Minimal-invasive microwave coagulation therapy for liver tumours: laparoscopic and percutaneous access]

INTRODUCTION

Local ablative treatments play an important role in current surgical treatment strategies. Radiofrequency ablation (RFA) as one of the most popular examples suffers from partly inacceptable local tumour control. Microwave coagulation therapy (MCT) is a comparatively new type of ablation promising several improvements. This series is to the best of our knowledge the first within the central European area, which reports on the successful clinical implementation of MCT in a surgical department.

PATIENTS AND MATERIALS

A novel 915 MHz system (MedWaves™, AveCure Inc., SanDiego, CA/U. S. A.) was used to treat 47 patients with 80 tumour nodules in 51 treatment sessions. Average tumour size was 2.6 ± 0.9 cm. Indications were hepatocellular carcinoma in 29 patients and metastases in 14 as well as 4 cholangiocellular carcinomas. The approach was laparoscopic (20) or percutaneous (31). High-risk conditions defined by unfavourable tumour localisation like invisibility in native transabdominal ultrasound, superficial tumour site or risk of heat sink phenomena were found in 28 cases (53 %).

RESULTS

Local recurrence rate was 17 % on a per-patient and 12 % on a per-tumour basis (n = 9). One patient died because of incurable upper gastrointestinal bleeding during the postoperative hospital stay. No MCT-associated complication occurred. Median follow-up period was 20 months. Local tumour recurrence was significantly different on comparing laparoscopic to percutaneous MCT (p = 0.032, χ2 test), as was global recurrence (p = 0.011, χ2 test). In a univariate logistic Cox regression, tumour size, access and high-risk localisation were significant prognostic factors for local tumour recurrence, however, in a multivariate reiteration, only the chosen access to MCT (p = 0.012) and tumour size (p = 0.044) remain significant.

CONCLUSION

MCT seems to be a useful tool, easy to implement in a surgical environment and may eventually prove to be superior to other local ablative treatment modalities. Even unfavourable tumour localisations could be treated safely and efficiently using MCT without increased risk of local tumour recurrence.

Treatment of recurrent hepatocellular carcinoma confined to the liver with repeated resection and radiofrequency ablation: a single center experience

BACKGROUND

Recurrence of hepatocellular carcinoma (HCC) after surgical treatment is a common problem. It can be treated by radiofrequency ablation (RFA) or repeated hepatic resection (HR). This report compares both in a retrospective, single-institution database.

PATIENTS AND METHODS

A prospectively collected database was retrospectively analyzed. RFA was performed under ultrasound control using two different monopolar devices. All kinds of access were used: open surgical (n=10), percutaneous (n=13) and laparoscopic (n=4). HR was performed using an ultrasound aspiration device. Indication for a particular treatment was allocated on a case-by-case basis; the final decision was often made intraoperatively.

RESULTS

Survival after RFA (median 40 months) was similar compared to that after HR (48 months, p=0.641, logRank-test). Tumor-free survival was markedly impaired after RFA (15 vs. 29 months). This difference was however not significant (p=0.07, logRank-test). Both groups were different regarding occurrence of cirrhosis, maximal tumor size, time after initial diagnosis and duration of the procedure.

CONCLUSION

In this non-randomized retrospective trial, survival and disease-free survival was not significantly different when compared between patients treated by RFA and HR. There was however a tendency towards a longer tumor-free survival in the resected patients.

[Radiofrequency ablation for treatment of colorectal liver metastases: scientific evidence and clinical reality]

Radiofrequency ablation (RFA) of colorectal liver metastases is frequently reported, but, however, lacks clear criteria for indication and reliable, convincing results with 5-year survival ranging from 17 to 48 %. RFA may be the appropriate treatment modality in approximately 3 to 5 % of all patients suffering from colorectal liver metastases. To date, RFA seems to be limited to no more than three metastases, each smaller than 3 cm. The main indication remains irresectability due to number, site, distribution and/or marginal liver function. Tumours in the vicinity of larger vessels (predominantly branches of portal or hepatic veins) are a case for controversy, since advances in hepatobiliary surgery enable a proportion of patients to undergo resections which would have been declared irresectable until most recently, and the oncological value of a thermoablation is questioned, as a certain amount of temperature is lost due to convective heat sinks. RFA is not a curative alternative to hepatic resection unless small tumours appear during open or laparoscopic procedures in a patient with elevated risk for early recurrence or postoperative morbidity following liver resection. The inclusion of RFA into a holistic system of oncological therapy is mandatory. Early RFA followed by systemic (regional?) chemotherapy can rather be recommended than chemo only, RFA only or first-line chemo with subsequent RFA.

Mandibular symphyseal distraction osteogenesis--simplified

The limb lengthening technique of distraction osteogenesis (DO) used in orthopedic surgery is a well established procedure. DO has been adapted to the facial skeleton to change the anterior-posterior position of the jaws. Historically, the mandibular arch transverse dimension has been considered immutable. Mandibular arch expansion is done with a variety of methods including Schwarz plates, lingual arches, functional appliances and arch wires; these methods produce limited dimensional change with questionable long-term stability. Adapting the Ilizarov treatment protocol to the mandibular symphysis can produce a regenerate bone thereby adding dimension to the innate basal bone. This can then be used to produce a potentially greater effect than the conventional modes of mandibular expansion. The modified mandibular symphyseal distraction device used by the authors is a tooth borne device fabricated with a Schwartz screw and self cured acrylic resin coverage over all the erupted mandibular teeth. The appliance used by the authors has been found to be very economical, easy to fabricate and clinically efficient. The surgical approach used, requiring surgery under local anesthesia in the outpatient department obviates need of hospital admission and the cost and time factors associated with in-patient therapy Mandibular Symphyseal Distraction Osteogenesis (MSDO) with this innovative low cost approach may be compared in a multi centric study with other established methods of MSDO.

Clinical evaluation of immediate loading of titanium orthodontic implants

BACKGROUND

Skeletal anchorage using dental implants, miniplates, miniscrews and microscrews provides an absolute anchorage for tooth movement. Miniscrew and microscrew implants have many benefits such as ease of placement and removal and immediate orthodontic force application.

METHODS

Fifteen subjects in the permanent dentition with an overjet ≥6 mm received treatment with the 0.018-inch pre-adjusted edgewise appliance system (Roth prescription) and extraction of all first premolars. Titanium orthodontic implants were placed in both the upper quadrants and were immediately loaded with elastic chain from the implant head to the sectional arch wire.

RESULT

The overall success rate of immediate loaded titanium orthodontic micro implants (OMI) in the present study was 83.33%, with a mean chairside time of 15.33 min of placing two implants in each patient. Peri-implant inflammation was the only complication observed. Most failures were in the initial part of the study. There was no significant difference in the success rate of implants based on sex, side of placement (right or left) and type of malocclusion.

CONCLUSION

The OMIs used in the present study proved to be effective and well tolerated in producing immediate orthodontic anchorage for the retraction.

A germline or de novo mutation in two families with Gaucher disease: implications for recessive disorders

Gaucher disease (GD) is an autosomal recessive storage disorder that most commonly results from the inheritance of one identifiable mutant glucocerebrosidase (GBA1) allele from each parent. Here, we report two cases of type 2 GD resulting from the inheritance of one identifiable paternal mutant allele and one allele that likely resulted from a maternal germline mutation. Germline mutations or mosiacism are not generally associated with autosomal recessive disorders. The probands from the two unrelated families had the same maternal mutation, leu444pro, that we propose resulted from a de novo maternal germline mutation occurring at this known 'hotspot' for mutation. This first report of a germline mutation for a common point mutation leu444pro (c.1448 T>C;p.leu483pro) in GD has significant implications for molecular diagnostics and genetic counseling in recessive disorders.

Homozygous PLCB1 deletion associated with malignant migrating partial seizures in infancy

Malignant migrating partial seizures in infancy (MMPEI) is an early onset epileptic encephalopathy with few known etiologies. We sought to identify a novel cause of MMPEI in a child with MMPEI whose healthy parents were consanguineous. We used array comparative genomic hybridization (CGH) to identify copy number variants genome-wide and long-range polymerase chain reaction to further delineate the breakpoints of a deletion found by CGH. The proband had an inherited homozygous deletion of chromosome 20p13, disrupting the promoter region and first three coding exons of the gene PLCB1. Additional MMPEI cases were screened for similar deletions or mutations in PLCB1 but did not harbor mutations. Our results suggest that loss of PLCβ1 function is one cause of MMPEI, consistent with prior studies in a Plcb1 knockout mouse model that develops early onset epilepsy. We provide novel insight into the molecular mechanisms underlying MMPEI and further implicate PLCB1 as a candidate gene for severe childhood epilepsies. This work highlights the importance of pursuing genetic etiologies for severe early onset epilepsy syndromes.

Occupational Hazards among Dental Surgeons

BACKGROUND

This study was conducted to assess and increase the level of awareness of occupational hazards among the dental surgeons of Indian Navy.

METHODS

The data was obtained using a self-administrated questionnaire from 17 serving dental surgeons that included questions on personal data, awareness of occupational hazards, safety measures practiced and experience of occupational hazard while in practice.

RESULTS

All the respondents were aware of the occupational hazards at workplace and had been vaccinated against Hepatitis B infection. 82.3% had regular exposure to dental amalgam. Backache was the commonest hazard in 70.59% members of the study.

CONCLUSION

This study shows that although there appears to be a high level of awareness of exposure to occupational hazards among the dental surgeons of the Indian Navy, the practical steps to prevent them needs to be reinforced. Increased awareness must be created about the dangers of chronic mercury poisoning, its prevention, the importance of regular monitoring of blood mercury levels and the mercury vapour levels in the clinic.

Feasibility of hepatic radiofrequency ablation in patients with bilioenteric anastomoses

BACKGROUND/AIMS

Radiofrequency ablation (RFA) in the liver is contraindicated in the presence of bilioenteric anastomoses, because it predisposes to occasionally devastating infectious complications. The purpose of this single-center experience is to demonstrate the technical feasibility of such procedures.

METHODOLOGY

Patients with bilioenteric anastomoses were offered ultrasound-guided RFA, if an interdisciplinary tumor board endorsed this decision, or an intraoperative opportunity to achieve a tumor-free situation emerged. All procedures were carried out under general anesthesia in a surgical operation theatre. RFA was performed percutaneously (n=3) and open surgically (n=3) with two different types of monopolar devices. All patients received antibiotic prophylaxis with various different agents.

RESULTS

Six patients with seven tumor nodules were treated. The average age of the patients was 59 +/- 7 years. Mean size of the tumors was 20 +/- 7 mm. Median follow up was 15 months. No infectious complication including intrahepatic abscess occurred. No local recurrence was detected.

CONCLUSIONS

The presented data indicates the feasibility of RFA in patients with bilioenteric anastomoses, and infectious problems, namely intrahepatic abscess formation, do not inevitably occur. The role of antimicrobial prophylaxis remains unclear. The importance of ensuring an unobstructed and uninhibited biliary flow distally in the bilioenteric track is stressed.

Advances in image guided conventional and minimal invasive liver surgery

Technological developments, advances in perioperative medicine and ongoing scientific research have led to reduced rates of mortality and morbidity in patients undergoing major liver surgery. Under these conditions, the frontier of resectability is constantly in movement towards more complex cases with extended tumor spread and potentially minimized remnant liver volume. A promising technique to support oncological correct and safe liver surgery is the introduction of preoperative computer based planning models and intraoperative navigation systems. Whereas three-dimensional (3D) liver models are commercially available and have been clinically implemented, the use of navigation systems is currently under evaluation by different groups using a variety of techniques. This manuscript is meant to give the reader an overview on current developments, difficulties and future aspects of image guided liver surgery.

Ultrasonographic evaluation of inflammatory swellings of buccal space

OBJECTIVES

The main objective of the study was a) to differentiate cellulitis and abscess in buccal space region, b) to study the ultrasonographic anatomy of cheek region and c) to investigate the use of ultrasound in the diagnosis of inflammatory swellings of cheek region.

PATIENTS AND METHODS

The study consisted of 25 patients with unilateral buccal space inflammatory swellings of odontogenic origin. The contra lateral side was used as control. Toshiba ultrasonographic device with a linear array transducer (5-8 MHz) was used. The areas of interest were scanned under both transverse and longitudinal sections and were interpreted by a single observer. The clinical diagnosis of cellulitis or abscess was confirmed by the absence or presence of pus respectively both sonographically and by aspiration. Also various anatomical structures present in buccal space were studied.

RESULTS

Clinically 23 (92%) were diagnosed as buccal space abscess and 2 (8%) were cellulitis. Ultrasonographically and therapeutically 24 (96%) were buccal space abscess and 1 (4%) was cellulits. The sensitivity of clinical criteria over ultrasonographic diagnosis was 96% with a specificity of 100%. Also the cheek thickness in males and females varied from 8.2 to 17.1 mm with a mean of 11.6 mm+/-2.1 (SD) and 8.2 mm to 14.2 mm with a mean of 11+/-1.8 (SD). The subcutaneous tissue appeared moderately echogenic, buccinator--highly echogenic, deep adipose tissue--less echogenic and parotid duct was appreciated as a thin hyperechogenic band crossing the buccinator muscle. Buccal space, masticator space and parotid space were appreciated.

CONCLUSION

This study supports the ultrasonographic method of imaging of orofacial inflammatory swellings with high sensitivity and specificity. This imaging modality can also help in aspiration of pus in different spaces. We have described the ultrasonographic anatomy of the above mentioned spaces which can help a beginner in this field.

Voltage-gated sodium channels are required for heart development in zebrafish

RATIONALE

Voltage-gated sodium channels initiate action potentials in excitable tissues. Mice in which Scn5A (the predominant sodium channel gene in heart) has been knocked out die early in development with cardiac malformations by mechanisms which have yet to be determined.

OBJECTIVE

Here we addressed this question by investigating the role of cardiac sodium channels in zebrafish heart development.

METHODS AND RESULTS

Transcripts of the functionally-conserved Scn5a homologs scn5Laa and scn5Lab were detected in the gastrulating zebrafish embryo and subsequently in the embryonic myocardium. Antisense knockdown of either channel resulted in marked cardiac chamber dysmorphogenesis and perturbed looping. These abnormalities were associated with decreased expression of the myocardial precursor genes nkx2.5, gata4, and hand2 in anterior lateral mesoderm and significant deficits in the production of cardiomyocyte progenitors. These early defects did not appear to result from altered membrane electrophysiology, as prolonged pharmacological blockade of sodium current failed to phenocopy channel knockdown. Moreover, embryos grown in calcium channel blocker-containing medium had hearts that did not beat but developed normally.

CONCLUSIONS

These findings identify a novel and possibly nonelectrogenic role for cardiac sodium channels in heart development.

[Impact of the body mass index on the prognosis and complication rate after surgical resection of cancers at the oesophagogastric junction]

BACKGROUND

An elevated body mass index (BMI) is associated with an increased incidence of cancer at the gastro-oesophageal junction. Less is known about the postoperative complication rate and prognosis in relation to the BMI.

PATIENTS AND METHODS

We investigated 108 patients with cancer of the cardia and a BMI below (group 1, n = 56) or above (group 2, n = 52) 25 kg / m (2), who were operated from 2000 to 2006 in our department. According to the Siewert classification, the tumours were subdivided into 3 types. Patients with type I cancers (n = 26) received a transthoracic oesophageal resection with gastric pull up. Patients with type II (n = 61) or type III (n = 21) cancers underwent an extended gastrectomy. The complication rates and survival were analysed.

RESULTS

The complications were pulmonary (respiratory insufficiency n = 12, pneumonia n = 12, bronchitis n = 7, pulmonary embolism n = 2), surgical (anastomotic leakage n = 7, abscesses n = 8, bleeding n = 2, chylus fistula n = 1), or functional (dysphagia n = 5, nausea n = 5, heart burn n = 4, delayed enteral passage n = 6, vomiting n = 9). Patients of group 2 showed more delayed enteral passages (5 vs. 1) and more vomiting (7 vs. 2) than those of group 1. The median stay in the intensive care unit was shorter in group 1 than in group 2 (3 vs. 5 days) (p = 0.021). Overall hospitalisation was 14 days in the mean in both groups. We found no significant difference in the postoperative mortality of 6.5 % (n = 7) between the two groups. Overall survival after a follow-up of 42 months was 34 % (group 1) and 25 % (group 2). The difference did not reach statistical significance (p = 0.961). Patients with an elevated BMI show slightly more complications than those with a lower BMI.

CONCLUSIONS

Our data show that patients with elevated BMI have slightly more complications and an identical long term survival as patients with normal body weight.

Surgical results of patients after esophageal resection or extended gastrectomy for cancer of the esophagogastric junction

Precise classification of cancers of the esophagogastric junction according to Siewert may be difficult for the presence of Barrett's esophagus or hiatal hernia, which subsequently leads to a difficult choice of the surgical procedure of esophagectomy or gastrectomy. Ninety-six patients with such cancers were operated on in our department in 7 years. Twenty-nine patients (30.2%), classified as type I (group 1), underwent a transthoracic esophagectomy with gastric pull up. Sixty-seven patients (69.8%) classified as type II or III (group 2) underwent an extended gastrectomy. We compared the patients of both groups retrospectively for disease-free survival and postoperative complications. The general performance status of most patients was comparable in both groups and was assigned to the American Society of Anesthesiologists class II or III. Statistically significant differences between the groups were seen for the postoperative reintubation rate [group 1: 31.0% vs. group 2: 9.0% (P = 0.009)], median time for surgery [group 1: 6 (3.5-8.5) hours vs. group 2: 4.7 (2.2-11.5) hours (P = 0.001)], time in the intensive care unit [group 1: 6 (3-85) days vs. group 2: 3 (1-54) days (P = 0.001)], median hospitalization time [group 1: 23 (14-105) days vs. group 2: 18 (10-63) days (P = 0.018)]. No statistical difference was observed for the recurrence-free survival of 40% after 3 years (P = 0.311), the mortality rate, the morbidity rate (P = 0.108), surgical and respiratory complications, and the incidence of anastomotic leakage (P = 0.645). We conclude that in selected cases it may be possible to perform an extended gastrectomy for small type I cancers.

Development and validation of a three dimensional ultrasound based navigation system for tumor resection

BACKGROUND

Intraoperative navigation is a rapidly emerging procedure in orthopaedic surgery and neurosurgery. For abdominal tumors (e.g. liver metastasis) and soft tissue tumors there is only limited experience with navigation techniques due to problems of organ shift and tissue deformation. We have developed a navigation system for tumor resection in soft tissue based on 3D ultrasound imaging and optical tracking.

METHODS

Two different modes of navigation were evaluated and compared with conventional surgery in an experimental soft tissue model. Both techniques were based on 3D ultrasound and an optical tracking system for intraoperative real time registration of surgical instruments. These two techniques were used: a) Indirect navigation with ultrasound guided insertion of a tracked hook needle into the tumor; and b) Direct navigation using a 3D image which was obtained with an optically tracked 3D ultrasound probe. It was the aim of both techniques to achieve a circumferential resection margin of 2cm around the tumor.

RESULTS

A total of 23 resections were performed consisting of indirect (n=7) and direct (n=10) navigation and conventional surgery (n=6) as gold standard. For indirect navigation a median deviation from the ideal resection margin (accuracy) of 0.32cm was measured. Direct navigation showed an accuracy of 0.16cm compared to 0.42cm with conventional surgery. Navigated surgery showed for both techniques a significant increase of resection accuracy compared to conventional resection (p<0.05).

CONCLUSION

3D ultrasound based indirect and direct optoelectronic navigation for resection of soft tissue tumors is feasible and may improve intraoperative orientation with increased surgical precision.

Vertebrate heart growth is regulated by functional antagonism between Gridlock and Gata5

Embryonic organs attain their final dimensions through the generation of proper cell number and size, but the control mechanisms remain obscure. Here, we establish Gridlock (Grl), a Hairy-related basic helix-loop-helix (bHLH) transcription factor, as a negative regulator of cardiomyocyte proliferative growth in zebrafish embryos. Mutations in grl cause an increase in expression of a group of immediate-early growth genes, myocardial genes, and development of hyperplastic hearts. Conversely, cardiomyocytes with augmented Grl activity have diminished cell volume and fail to divide, resulting in a marked reduction in heart size. Both bHLH domain and carboxyl region are required for Grl negative control of myocardial proliferative growth. These Grl-induced cardiac effects are counterbalanced by the transcriptional activator Gata5 but not Gata4, which promotes cardiomyocyte expansion in the embryo. Biochemical analyses show that Grl forms a complex with Gata5 through the carboxyl region and can repress Gata5-mediated transcription via the bHLH domain. Hence, our studies suggest that Grl regulates embryonic heart growth via opposing Gata5, at least in part through their protein interactions in modulating gene expression.

[Transcutaneous ultrasound]

Preoperative transcutaneous ultrasound allows surgeons to assess the pathology directly, thus supplementing clinical examination of the patient. Technical advances including power doppler, three-dimensional ultrasound, and the advent of ultrasound contrast agents have increased the quality and broadened the diagnostic spectrum of ultrasound. This article reviews relevant new aspects of transcutaneous ultrasound in the surgical setting.

ST-segment abnormalities and premature complexes are predictors of new-onset atrial fibrillation: the Niigata preventive medicine study

BACKGROUND

Left ventricular hypertrophy is a known risk factor for atrial fibrillation (AF). However, it is not well understood whether other electrocardiogram abnormalities are associated with development of AF.

METHODS

This was a community-based cohort study based upon a database of annual health examinations. We included 63,386 subjects aged > or = 50 years, without baseline AF (including atrial flutter), structural heart disease, or heart failure, who completed the annual examination during a 10-year follow-up period (1991-2002). The electrocardiographic risk factors for AF were studied in the subjects.

RESULTS

Atrial fibrillation developed in 873 subjects. Age, male sex, body mass index, hypertension, systolic and diastolic blood pressure, and diabetes were significant risk factors for the development of AF. In multivariable logistic regression analysis adjusted for these risk factors, electrocardiographic left ventricular hypertrophy (odds ratio [OR], 1.43), ST-segment abnormality without left ventricular hypertrophy (OR, 1.89), and the presence of premature complexes during a 10-second recording (OR, 2.89) were significantly associated with AF, whereas either right (OR, 0.84) or left bundle branch block (OR, 0.96) was unrelated. The risk for AF increased progressively with the severity of both ST-segment change and premature complexes.

CONCLUSIONS

ST-segment abnormality and comparably high-frequency premature complexes were each associated with increased risk for the development of AF. These electrocardiographic findings may be useful to stratify high-risk subjects for new-onset AF.

[Ultrasound contrast agents for liver diagnostics]

Ultrasound contrast agents have achieved a high level of acceptance in diagnostics of liver tumors. Contrast-enhanced ultrasound can, on the one hand, be used for detection of liver tumors, e.g., during the search for metastases in tumor staging, and, on the other hand, for tumor characterization. The dispersion behavior of the ultrasound contrast agent plays a decisive role in the characterization and the enhancement patterns correspond to a large extent to those already known from contrast-enhanced computed tomography. Contrast-enhanced ultrasound can also be employed for monitoring ablative tumor therapies, visualization of vessels difficult to depict, and measurement of the so-called liver transit time.

Bonded Pendulum Appliance

Orthodontic therapies involving no compliance from patients are the mainstay of modern orthodontics. Class II division 1 malocclusions constitute the bulk of cases requiring extractions to facilitate space gain to correct it. The Pendulum Appliance is an effective and reliable method for distalizing maxillary molars. Its major advantages are minimal dependence on patient compliance, ease of fabrication, one-time activation, adjustment of the springs if necessary to correct minor transverse and vertical molar positions and patient-acceptance. Simple laboratory procedure for fabrication and relatively low cost make it an excellent appliance to be incorporated into regular practice.

Charakterisierung von Lebertumoren durch kontrastverstärkte Sonographie und digitale Graustufenbestimmung

PURPOSE

The characterization of different liver tumors is of therapeutic and prognostic relevance and has been the purpose of several studies. Although ultrasound offers the opportunity to detect hepatic tumors without ionizing radiation, its previous techniques did not lead toward a definitive differentiation of different tumor entities. The purpose of this study was the clinical evaluation of contrast enhanced ultrasound followed by quantitative digital analysis in patients with focal hepatic tumors.

MATERIALS AND METHODS

In a prospective study, 50 patients (18 females, 32 males, age 28 to 83 years, mean age 59.4 years) with liver tumors previously detected by CT (n = 47) or MRI (n = 3) were examined by ultrasound of the upper abdomen using conventional technique and phase inversion technique after intravenous application of sulfur-based contrast enhancer SonoVue. At scheduled intervals after application of the contrast enhancer, a digital image was stored and the characteristic signal course of each lesion determined semiquantitatively. The gold standard was either resection (n = 17), percutaneous needle biopsy (n = 19) or the clinical course (n = 14).

RESULTS

While the percentage of tumors correctly characterized by CT/MRI amounted to 78 %, the percentage increased from 60 % using conventional ultrasound to 86 % using contrast enhanced ultrasound including grey-scale analysis. Typical graphs were achieved for different tumor entities on digital grey-scale analysis. The optimal intervals for the differentiation of particular entities were 20 and 100 seconds after injection.

CONCLUSION

Quantification of contrast enhanced ultrasound is an addition to the previous diagnostic procedure in hepatic tumors. It offers the possibility of an investigator-independent characterization of lesions and should be evaluated in further studies.