Effectiveness of full Pulpotomy compared with Root canal treatment in managing teeth with signs and symptOms indicative of irreversible pulpitis: a protocol for prospectiVE meta-analysis of individual participant data of linked randomised clinical trials (PROVE)

BACKGROUND

Full pulpotomy has been proposed as an alternative to root canal treatment in teeth with signs and symptoms indicative of irreversible pulpitis (IRP), but the evidence is limited, relying on underpowered studies with a high risk of bias. The aim of this study is to conduct a prospective meta-analysis (PMA) of individual participant data of a series of individual randomised trials to provide robust evidence on the clinical and cost-effectiveness of pulpotomy compared with root canal treatment.

METHODS

Individual participant data will be obtained from a series of randomised trials designed and conducted by a consortium of multi-national investigators with an interest in vital pulp treatment. These individualised trials will be conducted using a specified protocol, defined outcomes, and outcome measures. Ten parallel-group randomised trials currently being conducted in 10 countries will provide data from more than 500 participants. The primary outcome is a composite measure defined as (1) the absence of pain indicative of IRP, (2) the absence of signs and symptoms indicative of acute or chronic apical periodontitis, and (3) the absence of radiographic evidence of failure including radiolucency or resorption. Individual participant data will be obtained, assessed, and checked for quality by two independent reviewers prior to the PMA. Pooled estimates on treatment effects will be generated using a 2-stage meta-analysis approach. The first stage involves a standard regression analysis in each trial to produce aggregate data on treatment effect estimates followed by an inverse variance weighted meta-analysis to combine these aggregate data and produce summary statistics and forest plots. Cost-effectiveness analysis based on the composite outcome will be undertaken as a process evaluation to evaluate treatment fidelity and acceptability by patients and dentists.

RESULTS

The research question and trial protocol were developed and approved by investigators in all 10 sites. All sites use shared resources including study protocols, data collection forms, participant information leaflets, and consent forms in order to improve flow, consistency, and reproducibility. Each site obtained its own Institutional Review Board approval, and trials were registered in appropriate open access platforms. Patient recruitment has started in most sites, as of July 2023.

DISCUSSION

PMA offers a rigorous, flexible, and efficient methodology to answer this important research question and provide results with improved generalisability and external validity compared with traditional trials and retrospective meta-analyses. The results of this study will have implications for both the delivery of clinical practice and structured clinical guidelines' development.

TRIAL REGISTRATION

PROSPERO CRD42023446809. Registered on 08 February 2023.

Abstract P2-11-16: The safety and pathological impact of neoadjuvant radiotherapy for local advanced breast cancer undergoing mastectomy and autologous reconstruction

Introduction

Delayed breast reconstructions are preferred if post mastectomy radiotherapy is indicated due to lower complication rates compared to immediate permanent implant or autologous reconstructions (AR) but cosmetic outcomes are inferior. Radiotherapy has a deleterious effect on implants and autologous tissue and often an interim tissue expander is place which has inherent pain and complications.

However, neoadjuvant radiotherapy (NART) prior to surgery allows for definitive oncological surgery to be performed with an immediate AR in a single operation and the avoidance of a temporary expander. The aim of this study is to assess the safety and downstaging impact of NART.

Methods

This is a prospective review of patients who underwent NART at GenesisCare Victoria, the Austin and the Alfred hospital. 59 LABC patients (median age 49.2 years) were divided into two groups; clinically staged and pathologically staged for reporting. There were 15 pathologically staged patients (pStage 2A-3C) and 43 clinically staged patients (cStage 2A-3B). All patients initially underwent NACT, followed by NART (median dose 50.4Gy in 28 fractions) to the breast, supraclavicular fossa and level 3 axilla with or without coverage of their Level 1 and 2 axilla, and/or internal mammary nodes. Approximately 6 weeks after completing NART, patients underwent definitive surgery and AR.

Results

All patients completed their NART with minimal toxicity and no break in treatment. 55 patients had a skin-sparing mastectomy (SSM) and 3 patients had a modified radical mastectomy. All clinically staged patients underwent an AD. ARs with a DIEP flap were performed in the majority of patients (51). The average length of hospitalisation was 6.2 days.

The Miller Payne (MP) scoring index was used to record pathological responses in clinically staged patients. Overall 36 patients achieved significant downstaging of their disease, with MP scores of 5/5 for 20 and 4/5 for 16. Only 1 patient failed to achieve any downstaging with a MP score of 1/5. All 12 Her2 positive patients, 3/5 Triple negative patients and 5/26 Luminal A/B patients achieved a MP score of 5/5. All patients achieved R0 resection margins. This included 6 patients who had initial cT4 disease (cT4a X2, cT4b X1 and cT4d X3). 15 patients had initial cN2/3 disease and all successfully underwent their axillary dissections with R0 resections achieved. 10/15 had no involved axillary nodes with significant scarring seen in 6. 5/15 had residual involved nodes with significant scarring seen in 3 patients.

Post surgical toxicities were graded using Clavien-Dindo classification. 8 significant grade 3 toxicities were seen in 6 patients, with no grade 4 or 5 toxicities. No patients developed DVT or PE. No flap losses were seen.

Median follow up is 23 months. Cosmesis was rated as good to excellent in all cases. 1 patient developed simultaneous loco-regional and distant recurrence with another 3 patients developing distant metastases only.

Conclusion

This review demonstrated that NART is a safe technique, which has not lead to an increase in surgical complication rates or resulted in a detriment in cosmetic outcome. NART can achieve a shorter, simpler reconstructive journey for patients.

Citation Format: Baker C, Chao MW, Jassal S, Neoh D, Bevington E, Hyett A, Grinsell D, Loh SW, Zantuck N, Stoney D, Foley C, Law M, Chew G, Yu V, Cheng M, Guerrieri M, Taylor K, Chipman M, Cokelek M, Lim Joon D, Foroudi F. The safety and pathological impact of neoadjuvant radiotherapy for local advanced breast cancer undergoing mastectomy and autologous reconstruction [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-11-16.

A nonvoxel-based dose convolution/superposition algorithm optimized for scalable GPU architectures

PURPOSE

Real-time adaptive planning and treatment has been infeasible due in part to its high computational complexity. There have been many recent efforts to utilize graphics processing units (GPUs) to accelerate the computational performance and dose accuracy in radiation therapy. Data structure and memory access patterns are the key GPU factors that determine the computational performance and accuracy. In this paper, the authors present a nonvoxel-based (NVB) approach to maximize computational and memory access efficiency and throughput on the GPU.

METHODS

The proposed algorithm employs a ray-tracing mechanism to restructure the 3D data sets computed from the CT anatomy into a nonvoxel-based framework. In a process that takes only a few milliseconds of computing time, the algorithm restructured the data sets by ray-tracing through precalculated CT volumes to realign the coordinate system along the convolution direction, as defined by zenithal and azimuthal angles. During the ray-tracing step, the data were resampled according to radial sampling and parallel ray-spacing parameters making the algorithm independent of the original CT resolution. The nonvoxel-based algorithm presented in this paper also demonstrated a trade-off in computational performance and dose accuracy for different coordinate system configurations. In order to find the best balance between the computed speedup and the accuracy, the authors employed an exhaustive parameter search on all sampling parameters that defined the coordinate system configuration: zenithal, azimuthal, and radial sampling of the convolution algorithm, as well as the parallel ray spacing during ray tracing. The angular sampling parameters were varied between 4 and 48 discrete angles, while both radial sampling and parallel ray spacing were varied from 0.5 to 10 mm. The gamma distribution analysis method (γ) was used to compare the dose distributions using 2% and 2 mm dose difference and distance-to-agreement criteria, respectively. Accuracy was investigated using three distinct phantoms with varied geometries and heterogeneities and on a series of 14 segmented lung CT data sets. Performance gains were calculated using three 256 mm cube homogenous water phantoms, with isotropic voxel dimensions of 1, 2, and 4 mm.

RESULTS

The nonvoxel-based GPU algorithm was independent of the data size and provided significant computational gains over the CPU algorithm for large CT data sizes. The parameter search analysis also showed that the ray combination of 8 zenithal and 8 azimuthal angles along with 1 mm radial sampling and 2 mm parallel ray spacing maintained dose accuracy with greater than 99% of voxels passing the γ test. Combining the acceleration obtained from GPU parallelization with the sampling optimization, the authors achieved a total performance improvement factor of >175 000 when compared to our voxel-based ground truth CPU benchmark and a factor of 20 compared with a voxel-based GPU dose convolution method.

CONCLUSIONS

The nonvoxel-based convolution method yielded substantial performance improvements over a generic GPU implementation, while maintaining accuracy as compared to a CPU computed ground truth dose distribution. Such an algorithm can be a key contribution toward developing tools for adaptive radiation therapy systems.

Lymph node yield following injection of patent blue V dye into colorectal cancer specimens

AIM

The study aimed to assess whether the ex vivo injection of patent blue V dye would increase lymph node yield in operative specimens of colorectal cancer.

METHOD

A randomized controlled trial was carried out in which patients undergoing resection for colonic cancer were allocated to patent V blue or no patent blue V dye submucosal injection of the operative specimen. The number of lymph nodes found in each group was compared.

RESULTS

Between 1 January and 31 December 2008, 68 patients were randomized. Thirty-three patients received patent blue V dye and 34 did not. In the former group the median number of blue nodes identified was 11, compared with a median of 9 in the no dye group. After the application of Carnoy's solution lymph node count was 16 in each group. There was no significant difference between all these results.

CONCLUSION

Ex vivo injection of patent blue V dye submucosally in a peritumour location did not increase the lymph node count or the percentage of specimens having more than 12 lymph nodes identified.

Dynamic hydrostatic pressure promotes differentiation of human dental pulp stem cells

The masticatory apparatus absorbs high occlusal forces, but uncontrolled parafunctional or orthodontic forces damage periodontal ligament (PDL), cause pulpal calcification, pulp necrosis and tooth loss. Morphology and functional differentiation of connective tissue cells can be controlled by mechanical stimuli but effects of uncontrolled forces on intra-pulpal homeostasis and ability of dental pulp stem cells (DPSCs) to withstand direct external forces are unclear. Using dynamic hydrostatic pressure (HSP), we tested the hypothesis that direct HSP disrupts DPSC survival and odontogenic differentiation. DPSCs from four teenage patients were subjected to HSP followed by assessment of cell adhesion, survival and recovery capacity based on odontogenic differentiation, mineralization and responsiveness to bone morphogenetic protein-2 (BMP-2). HSP down-regulated DPSC adhesion and survival but promoted differentiation by increasing mineralization, in vivo hard tissue regeneration and BMP-2 responsiveness despite reduced cell numbers. HSP-treated DPSCs displayed enhanced odontogenic differentiation, an indication of favorable recovery from HSP-induced cellular stress.

In vivo effects of CB2 receptor-selective cannabinoids on the vasculature of normal and arthritic rat knee joints

BACKGROUND AND PURPOSE

Cannabinoids (CBs) are known to be vasoactive and to regulate tissue inflammation. The present study examined the in vivo vasomotor effects of the CB2 receptor agonists JWH015 and JWH133 in rat knee joints. The effect of acute and chronic joint inflammation on CB2 receptor-mediated responses was also tested.

EXPERIMENTAL APPROACH

Blood flow was assessed in rat knee joints by laser Doppler imaging both before and following topical administration of CB2 receptor agonists. Vasoactivity was measured in normal, acute kaolin/carrageenan inflamed and Freund's complete adjuvant chronically inflamed knees.

KEY RESULTS

In normal animals, JWH015 and JWH133 caused a concentration-dependent increase in synovial blood flow which in the case of JWH133 was blocked by the selective CB2 receptor antagonist AM630 as well as the transient receptor potential vanilloid-1 (TRPV1) antagonist SB366791. The vasodilator effect of JWH133 was significantly attenuated in both acute and chronically inflamed knees. Given alone, AM630 had no effect on joint blood flow.

CONCLUSION AND IMPLICATIONS

In normal joints, the cannabinomimetic JWH133 causes hyperaemia via a CB2 and TRPV1 receptor mechanism. During acute and chronic inflammation, however, this vasodilatatory response is significantly attenuated.

Effect of Arylamine AcetyltransferaseNat3Gene Knockout onN-Acetylation in the Mouse

Arylamine N-acetyltransferases (NAT) catalyze the biotransformation of many important arylamine drugs and procarcinogens. NAT can either detoxify or activate procarcinogens, complicating the manner in which these enzymes may participate in enhancing or preventing toxic responses to particular agents. Mice possess three NAT isoenzymes: Nat1, Nat2, and Nat3. Whereas Nat1 and Nat2 can efficiently acetylate many arylamines, few substrates appear to be appreciably metabolized by Nat3. We generated a Nat3 knockout mouse strain and used it along with our double Nat1/2(-/-) knockout strain to further investigate the functional role of Nat3. Nat3(-/-) mice showed normal viability and reproductive capacity. Nat3 expression was very low in wild-type animals and completely undetectable in Nat3(-/-) mice. In contrast, greatly elevated expression of Nat3 transcript was observed in Nat1/2(-/-) mice. We used a transcribed marker polymorphism approach to establish that the increased expression of Nat3 in Nat1/2(-/-) mice is a positional artifact of insertion of the phosphoglycerate kinase-neomycin resistance cassette in place of the Nat1/Nat2 gene region and upstream of the intact Nat3 gene, rather than a biological compensatory mechanism. Despite the increase in Nat3 transcript, the N-acetylation of p-aminosalicylate, sulfamethazine, 2-aminofluorene, and 4-aminobiphenyl was undetectable either in vivo or in vitro in Nat1/2(-/-) animals. In parallel, no difference was observed in the in vivo clearance or in vitro metabolism of any of these substrates between wild-type and Nat3(-/-) mice. Thus, Nat3 is unlikely to play a significant role in the N-acetylation of arylamines either in wild-type mice or in mice lacking Nat1 and Nat2 activities.

National survey on the susceptibility of Bacteroides fragilis group: report and analysis of trends in the United States from 1997 to 2004

The susceptibility trends for the species of the Bacteroides fragilis group against various antibiotics from 1997 to 2004 were determined by using data for 5,225 isolates referred by 10 medical centers. The antibiotic test panel included ertapenem, imipenem, meropenem, ampicillin-sulbactam, piperacillin-tazobactam, cefoxitin, clindamycin, moxifloxacin, tigecycline, chloramphenicol, and metronidazole. From 1997 to 2004 there were decreases in the geometric mean (GM) MICs of imipenem, meropenem, piperacillin-tazobactam, and cefoxitin for many of the species within the group. B. distasonis showed the highest rates of resistance to most of the beta-lactams. B. fragilis, B. ovatus, and B. thetaiotaomicron showed significantly higher GM MICs and rates of resistance to clindamycin over time. The rate of resistance to moxifloxacin of B. vulgatus was very high (MIC range for the 8-year study period, 38% to 66%). B. fragilis, B. ovatus, and B. distasonis and other Bacteroides spp. exhibited significant increases in the rates of resistance to moxifloxacin over the 8 years. Resistance rates and GM MICs for tigecycline were low and stable during the 5-year period over which this agent was studied. All isolates were susceptible to chloramphenicol (MICs < 16 microg/ml). In 2002, one isolate resistant to metronidazole (MIC = 64 microg/ml) was noted. These data indicate changes in susceptibility over time; surprisingly, some antimicrobial agents are more active now than they were 5 years ago.

General gynaecology: Intrauterine lignocaine as an anaesthetic during endometrial sampling: a randomised double-blind controlled trial

OBJECTIVE

To evaluate the effectiveness of intrauterine lignocaine as an anaesthetic during endometrial sampling.

DESIGN

Prospective, randomised, double-blind, placebo-controlled trial.

SETTING

Outpatient gynaecological minor operation unit in a public hospital.

POPULATION

Two hundred premenopausal women scheduled for endometrial sampling because of abnormal uterine bleeding.

METHODS

Transcervical intrauterine instillation of 5 mL of 2% lignocaine or 5 mL of normal saline before performing endometrial sampling with vacuum aspirator.

MAIN OUTCOME MEASURES

Evaluation of pain associated with the procedure using a visual analogue scale.

RESULTS

The use of intrauterine lignocaine reduced pain during suction curettage in endometrial sampling.

CONCLUSIONS

Transcervical instillation of lignocaine reduced pain during endometrial sampling.

Chorioamnionitis and outcome in extremely preterm infants

INTRODUCTION

Chorioamnionitis is a risk factor for preterm delivery. Intrauterine infection leads to the fetal inflammatory response which is characterised by elevated cytokine levels. Chorioamnionitis is reported to cause accelerated but abnormal lung maturation, resulting in decreased incidence of respiratory distress syndrome (RDS) but increased chronic lung disease (CLD), and predisposes the infant to cerebral injury.

OBJECTIVE

To investigate the relation between chorioamnionitis and RDS, CLD, cerebral lesions, neurodevelopmental outcome and mortality in a cohort of extremely premature infants.

MATERIALS AND METHODS

Infants born between 1997 and 2001 with a gestational age of less than 28 weeks or a birth weight of less than 1000 g were divided into two groups: Group 1 with evidence of chorioamnionitis and Group 2 without. Outcomes of these two groups of infants were compared.

RESULTS

A total of 388 infants were included (105 in Group 1 and 283 in Group 2). Chorioamnionitis was significantly associated with an increased risk of extreme preterm delivery. Group 1 showed a trend towards an increased incidence of CLD and mortality, while the incidence of periventricular leukomalacia, retinopathy of prematurity (ROP) and necrotising enterocolitis (NEC) were similar between the two groups. Subgroup analysis of 2-year neurodevelopmental outcome showed an increased trend towards cerebral palsy and visual impairment, while the incidence of developmental delay and hearing impairment are similar between the two groups.

CONCLUSION

Extremely preterm infants with chorioamnionitis showed a trend towards an increased incidence of CLD, mortality, cerebral palsy and visual impairement, but a decreased risk of RDS.

Variation in mortality and intraventricular haemorrhage in occupants of Pacific Rim nurseries

OBJECTIVE

A network of neonatal intensive care units in Pacific Rim countries was formed to compare infant risk factors, clinical practices, and outcomes for very low birthweight infants.

METHODOLOGY

A multicentre, prospective study compared outcomes for infants born smaller than 1501 g or at less than 31 weeks gestation.

RESULTS

Gestational age-specific survival and incidence of intracranial haemorrhage varied for infants born in these nurseries. We found differences in infant risk factors among the nurseries. There were also significant differences in the use of antenatal steroids, but similar rates for Caesarean section and surfactant treatment. The factor most predictive of neonatal death and severe intracranial abnormality was an elevated Clinical Risk Index for Babies (CRIB) score. Antenatal steroid treatment (>24 h prior to delivery) was associated with improved survival and decreased incidence of severe intracranial abnormalities. Antenatal steroid treatment for less than 24 h prior to delivery was not associated with improved survival. Caesarean delivery was associated with improved survival, but showed no benefit regarding the incidence of severe intracranial abnormality.

CONCLUSIONS

Our Pacific Rim nursery network found differences in neonatal outcomes that correlated best with measures of neonatal risk at birth, antenatal steroid treatment, and Caesarean delivery. These data emphasize the importance of obstetric care to improve postnatal outcomes in premature infants, and highlight the usefulness of CRIB scores in these patients.

Hepatitis B carrier and perinatal outcome in singleton pregnancy

The objective of this article is to evaluate the effect of hepatitis B antigenemia on perinatal outcome. Perinatal outcome of 824 women with hepatitis B surface antigen (HbsAg) was compared with 6281 women without hepatitis B surface antigen (control) from June 1996 to September 1998. The maternal characteristics were comparable between the two groups. Perinatal outcome was comparable between groups. The incidences of preterm birth, premature prelabor rupture of membranes, prelabor rupture of membranes, small for gestational age, neonatal jaundice, fetal distress, perinatal asphyxia, congenital abnormality, gastrointestinal tract abnormality, and perinatal mortality were similar among the two groups. We conclude that the presence of hepatitis B surface antigen in pregnant women does not pose additional risk for the pregnancy.

Caretaker Brca1: keeping the genome in the straight and narrow

Inheritance of germline BRCA1 mutations is associated with a high risk of breast and ovarian cancers. A multitude of cellular functions has been ascribed to BRCA1, including transcription activation and various aspects of DNA repair. So far, indirect evidence has indicated a role for BRCA1 in the repair of double-strand breaks. Recently, an elegant gene targeting design was used to provide definitive evidence that BRCA1 promotes homologous recombination and limits nonhomologous mutagenic repair processes. This reaffirms the role of BRCA1 as caretaker in preserving genomic integrity.