Eight-year retrospective study investigating tooth survival after primary non-surgical root canal treatment in a UK military cohort

INTRODUCTION

Root canal treatment (RCT) plays an important role in preserving the dentition by deferring other invasive treatments. Data on tooth survival and predictive factors for tooth loss after RCT in the military cohort are lacking. This investigation aimed to determine the proportion of teeth surviving in an 8-year period after RCT and identify potential predictive factors for tooth loss in a UK military cohort.

METHODOLOGY

A retrospective review of an integrated electronic health record for military patients who had received RCT was performed in a random sample of 205 patients (n=219 root-filled teeth) who had received RCT between 1 January 2011 and 1 January 2012. Tooth survival was defined as tooth presence, regardless of signs or symptoms, and measured from the point of root filling until either the end of the designated study period or time of extraction. Survival was evaluated using Kaplan-Meier estimates and association with tooth loss using the χ2 test. Potentially significant predictive factors were investigated using univariate Cox regression.

RESULTS

Tooth survival following RCT was 98% after 24 months; 88% after 48 months; 83% after 72 months; and 78% after 96 months. Four predictive factors were found to affect tooth loss as follows: preoperative pain (HR=3.2; p<0.001), teeth with less than two proximal contacts (HR=3.0; p=0.01), teeth with cores involving more than two surfaces (HR=2.0; p=0.03) and postoperative unscheduled dental attendances (UDA) (HR=2.7; p=0.01).

CONCLUSIONS

Within the limitations of this study, the presence of preoperative pain; teeth with less than two proximal contacts or with cores involving more than two tooth surfaces; and occurrence of postoperative UDA were found to significantly increase the hazard of tooth loss.

Hs27 fibroblast response to contact guidance cues

Contact guidance is the phenomena of how cells respond to the topography of their external environment. The morphological and dynamic cell responses are strongly influenced by topographic features such as lateral and vertical dimensions, namely, ridge and groove widths and groove depth ([Formula: see text], respectively). However, experimental studies that independently quantify the effect of the individual dimensions as well as their coupling on cellular function are still limited. In this work, we perform extensive parametric studies in the dimensional space-well beyond the previously studied range in the literature-to explore topographical effects on morphology and migration of Hs27 fibroblasts via static and dynamic analyses of live cell images. Our static analysis reveals that the [Formula: see text] is most significant, followed by the [Formula: see text]. The fibroblasts appear to be more elongated and aligned in the groove direction as the [Formula: see text] increases, but their trend changes after 725 nm. Interestingly, the cell shape and alignment show a very strong correlation regardless of [Formula: see text]. Our dynamic analysis confirms that directional cell migration is also strongly influenced by the [Formula: see text], while the effect of the [Formula: see text] and [Formula: see text] is statistically insignificant. Directional cell migration, as observed in the static cell behavior, shows the statistically significant transition when the [Formula: see text] is 725 nm, showing the intimate links between cell morphology and migration. We propose possible scenarios to offer mechanistic explanations of the observed cell behavior.

In silico interrogation of the miRNAome of infected hematopoietic cells to predict processes important for human cytomegalovirus latent infection

Human cytomegalovirus (HCMV) latency in CD34+ progenitor cells is the outcome of a complex and continued interaction of virus and host that is initiated during very early stages of infection and reflects pro- and anti-viral activity. We hypothesized that a key event during early infection could involve changes to host miRNAs, allowing for rapid modulation of the host proteome. Here, we identify 72 significantly upregulated miRNAs and three that were downregulated by 6hpi of infection of CD34+ cells which were then subject to multiple in silico analyses to identify potential genes and pathways important for viral infection. The analyses focused on the upregulated miRNAs and were used to predict potential gene hubs or common mRNA targets of multiple miRNAs. Constitutive deletion of one target, the transcriptional regulator JDP2, resulted in a defect in latent infection of myeloid cells; interestingly, transient knockdown in differentiated dendritic cells resulted in increased viral lytic IE gene expression, arguing for subtle differences in the role of JDP2 during latency establishment and reactivation of HCMV. Finally, in silico predictions identified clusters of genes with related functions (such as calcium signaling, ubiquitination, and chromatin modification), suggesting potential importance in latency and reactivation. Consistent with this hypothesis, we demonstrate that viral IE gene expression is sensitive to calcium channel inhibition in reactivating dendritic cells. In conclusion, we demonstrate HCMV alters the miRNAome rapidly upon infection and that in silico interrogation of these changes reveals new insight into mechanisms controlling viral gene expression during HCMV latency and, intriguingly, reactivation.

Do Concomitant Systematic Biopsies Add to Fusion Targeted Biopsies in the Diagnosis and Management of Clinically Significant Prostate Cancer?

OBJECTIVE

Magnetic resonance imaging targeted biopsy clearly detects more clinically significant prostate cancer than systematic biopsy. Whether concomitant systematic biopsy adds to targeted biopsy in the detection of clinically significant prostate cancer remains uncertain. The primary outcome measure of this study was to ascertain the percentage of clinically significant prostate cancer on systematic biopsy missed by targeted biopsy. Furthermore, we sought to determine whether systematic biopsy results influenced the clinical management of patients.

MATERIALS AND METHODS

This prospective observational study included all men undergoing Fusion targeted biopsy in our Health Board. All men had PI-RADS scores of 3-5 on magnetic resonance imaging. Histology from targeted biopsy and systematic biopsy was reviewed to determine any additional benefit of performing systematic biopsy. Clinical outcomes were also reviewed. Clinically significant prostate cancer was defined by (i) International Society of Urological Pathology ≥ 2 and (ii) UCL criteria of any primary Gleason 4 or core length ≥ 6 mm.

RESULTS

A total of 104 men were included in the study of whom 18 patients were biopsy naïve, 65 had at least 1 previous negative biopsy, and 20 had previous biopsies that showed clinically insignificant cancer. The percentage of clinically significant prostate cancer missed on targeted biopsy was between 9.1% and 11.1%. Moreover, 17.1% of patients with clinically significant prostate cancer would not have proceeded to radical treatment if the systematic biopsy had not been performed.

CONCLUSION

Our data support a growing field of evidence that although magnetic resonance imaging targeted biopsy is more sensitive than systematic biopsy at detecting clinically significant prostate cancer, systematic biopsy adds to the number of patients diagnosed with clinically significant prostate cancer in those already undergoing prostate biopsy.

P103 Impact of the COVID-19 pandemic on the sleep of patients of a multidisciplinary sleep clinic

Introduction

This study aimed to assess the impact of the COVID-19 pandemic on the sleep of adult patients of a multidisciplinary sleep clinic.

Methods

Patients were invited to complete online surveys: Survey 1 in October 2020 (increased COVID-19 restrictions) followed by Survey 2 in February 2021 (after easing of restrictions for a COVIDSafe summer).

Results

Of the 746 patients invited to participate, 73 completed and 8 partially returned Survey 1 (mean age 50.1 years, range 21–83 years, 58% female). Subsequently, 46 completed and 5 partially answered Survey 2. In Survey 1, 22/74 (29.7%) reported reduced sleep quantity and 31/75 (41.3%) indicated worse sleep quality compared with prior to the pandemic. In Survey 2, 33/46 (71.7%) described unchanged sleep quantity whilst 5/46 (10.9%) reported increased sleep quantity since easing COVID-19 restrictions. 36/46 (78.3%) indicated unchanged sleep quality whereas 5/46 (10.9%) described improved sleep quality since easing restrictions. However, 9/46 (19.6%) reported that their sleep remained worse compared with pre-pandemic. For patients who completed both surveys, there was no significant change in Insomnia Severity Index scores (Survey 1 mean 13.6, Survey 2 mean 12.9, mean difference -0.67 [95%CI -2.02, 0.68], p=0.32) or PROMIS Sleep-Related Impairment 8a T-scores (Survey 1 mean 59.0, Survey 2 mean 59.5, mean difference 0.44 [95%CI -1.55, 2.42], p=0.66).

Discussion

The COVID-19 pandemic has negatively affected the sleep of 44% of patients. Following easing of restrictions, symptoms of insomnia and sleep-related impairment did not change significantly, and 19.6% reported that their sleep was not back to their pre-pandemic baseline.

Malignant metastatic deposits in an immunocompromised patient—could this be tuberculosis?

We report the case of a 50-year-old female renal transplant patient who developed disseminated deposits initially diagnosed as metastatic malignancy of unknown primary. She declined a tissue diagnosis but subsequently developed recurrent sepsis and symptomatic unilateral pleural effusion. Mycobacterium tuberculosis was cultured from pleural fluid. Following introduction of anti-tuberculous medications, her symptoms improved rapidly and the progression of her disseminated deposits stabilized. Tuberculosis is well-known to be associated with immunocompromised patients. It is a curable disease and should remain an important differential diagnosis for transplant patients who develop suspicious malignant metastatic lesions.

Health promotion board-ministry of health clinical practice guidelines: treating tobacco use and dependence

The Health Promotion Board (HPB) has updated the clinical practice guidelines on Treating Tobacco Use and Dependence to provide health professionals in Singapore with evidence-based interventions for smoking cessation. This article reproduces the introduction and executive summary of key guideline recommendations (with recommendations from the guidelines) from the HPB-MOH Clinical Practice Guidelines on Treating Tobacco Use and Dependence, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Health Promotion Board website: http://www.hpb.gov.sg/cpg-smoking-cessation. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Impaired Akt phosphorylation in insulin-resistant human muscle is accompanied by selective and heterogeneous downstream defects

AIMS/HYPOTHESIS

Muscle insulin resistance, one of the earliest defects associated with type 2 diabetes, involves changes in the phosphoinositide 3-kinase/Akt network. The relative contribution of obesity vs insulin resistance to perturbations in this pathway is poorly understood.

METHODS

We used phosphospecific antibodies against targets in the Akt signalling network to study insulin action in muscle from lean, overweight/obese and type 2 diabetic individuals before and during a hyperinsulinaemic-euglycaemic clamp.

RESULTS

Insulin-stimulated Akt phosphorylation at Thr309 and Ser474 was highly correlated with whole-body insulin sensitivity. In contrast, impaired phosphorylation of Akt substrate of 160 kDa (AS160; also known as TBC1D4) was associated with adiposity, but not insulin sensitivity. Neither insulin sensitivity nor obesity was associated with defective insulin-dependent phosphorylation of forkhead box O (FOXO) transcription factor. In view of the resultant basal hyperinsulinaemia, we predicted that this selective response within the Akt pathway might lead to hyperactivation of those processes that were spared. Indeed, the expression of genes targeted by FOXO was downregulated in insulin-resistant individuals.

CONCLUSIONS/INTERPRETATION

These results highlight non-linearity in Akt signalling and suggest that: (1) the pathway from Akt to glucose transport is complex; and (2) pathways, particularly FOXO, that are not insulin-resistant, are likely to be hyperactivated in response to hyperinsulinaemia. This facet of Akt signalling may contribute to multiple features of the metabolic syndrome.

Development of an immortalised, post-pubertal gonadotrophin-releasing hormone neuronal cell line

Gonadotrophin-releasing hormone (GnRH) is important in reproduction, although some of the mechanisms for its synthesis and release remain elusive. Progress in understanding the GnRH neurone has been hampered by the limited number and diffuse distribution of the neurone in the mammalian brain. Several stable GnRH-expressing cell lines have been developed using in vivo expression of the simian virus 40 T Antigen (TAg), and they have been helpful for the study of gene expression and neuronal function. However, expression of an immortalising gene may interfere with normal cellular function. We developed a novel GnRH-secreting cell line transgenic mouse model suitable for targeted transformation in post-pubertal mice using a tetracycline-regulated TAg transgene. This clonal cell line, GRT, expresses neuronal markers and GnRH. GRT cells grown in medium containing tetracycline-free serum express increasing mRNA levels of GnRH associated with declining levels of TAg expression. The novelty and ultimately the usefulness of this cell line is that TAg expression, which could affect the GnRH neuronal phenotype, can be regulated by tetracycline.

Skin wound closure with a novel shape-memory alloy fixator

BACKGROUND

Previously, we have described novel, thermally deployable tissue fixators based on the shape-memory properties of nickel titanium. The present study reports on the in vivo wound closure with these fixators as a preliminary to evaluating their use for bowel anastomoses.

METHODS

Twenty adult Sprague-Dawley rats had 2.0-cm dorsal skin incisions approximated either with shape-memory alloy (SMA) fixators or conventional skin staples on a random basis. Electrical resistance heating was used to transform and deploy the SMA fixators into the wound. The rats were killed on day 14 or day 28 and wound specimens were harvested for force distraction studies and histologic examination.

RESULTS

There was no incidence of wound dehiscence. 14- and 28-day wounds from both groups showed no significant difference in breaking force or energy. Histology revealed appropriate stages of wound healing for both SMA-closed and control wounds.

CONCLUSIONS

The results confirm the efficacy and safety of tissue-edge approximation with SMA fixators.

Therapeutic and reproductive cloning--implications and recommendations

The announcement of Dolly's birth took the world by storm, mainly because what was thought impossible has become possible. Optimism that new approaches in agriculture and medicine abound, as much as fear and imagination leading to Frankenstein-like scenarios. Scientifically, cloning refers to replicating an animal with the same nuclear genetic material; whilst it may refer to embryos as the source material, the current storm refers to differentiated ("somatic") cells. Cloning technology is useful in the following areas: agriculture, to produce animals of superior or specific qualities; endangered animals, to increase genetic diversity through widening the gene pool; understanding fundamental questions in developmental embryology, through the use of laboratory animals; and in human therapy, to produce cells and possibly tissues for repair and regeneration. In the first 2 instances, it is reproductive cloning. In the last instance, it is therapeutic cloning, as no individuals are "produced". Human reproductive cloning is not allowed by all governments that have deliberated on it, and therapeutic cloning is allowed by some under certain circumstances. As therapeutic cloning has great potential in cures of many diseases, it should be allowed but with safeguards to prevent abuse and reproductive cloning in the human.

Diabetes mellitus and bladder cancer--an epidemiological relationship?

An epidemiological association between diabetes mellitus and transitional cell carcinoma of the bladder has been proposed. This study looked retrospectively at 125 patients with transitional cell carcinoma of the bladder as a study group and 80 other hospital patients with conditions not specifically associated with diabetes mellitus as a control group. Diabetic patients had an increased, significant odds ratio for bladder cancer compared with non diabetics even after adjustment for smoking and age [OR: 2.69 p=0.049 (95% CI 1.006-7.194)] A history of smoking OR 2.16 p=0.013 (95% C.I. 1.175-3.964) is a significant independent association with transitional cell carcinoma of the bladder as is age: p=0.001 OR 1.07. We propose potential pathogenic pathways for transitional cell carcinoma of the bladder in diabetic patients based on altered integrin and cadherin distribution in urothelial cells in diabetic patients. A larger study is planned to confirm an association between diabetes mellitus and transitional cell carcinoma of the bladder.

Evaluation of the Hemocue portable hemoglobinometer after major joint arthroplasty

We evaluated the potential use of the Hemocue (Hemocue AB, Sweden) portable hemoglobinometer on the 1st postoperative evening after major joint arthroplasty. We compared hemoglobinometer values with conventional Coulter counter laboratory analysis in a population of 67 patients. The hemoglobinometer proved practical, economical, and accurate in general, although 2 outlying values were severe enough as potentially to influence clinical decision making. Potential causes and solutions are discussed.

Immigration and economic welfare: resource and environmental aspects

"The relation between immigration and the economic welfare of residents is analyzed for resource-rich economies (such as Australia) both under competitive conditions and when various distortions are present. Immigration provides efficiency gains for residents under distortion-free competition for standard 'gains from trade' reasons. Such reasons, however, tend to be ignored by immigration and 'optimal population' theorists who raise the issue of restricting immigration without explicitly referring to the distortions. In situations where distortions and externalities are present, we argue that it is generally preferable to devise policies which specifically target the distortions than to restrict immigration."

The evolution and outcome of cavitating periventricular leukomalacia in infancy. A study of 46 cases

Forty six infants with the ultrasonic diagnosis of cavitating periventricular leukomalacia (CPVL) have been reviewed. Follow up examination results allow correlation between the ultrasound appearances and subsequent neurodevelopmental and neurological deficits. The highest incidence of this condition was found in infants at and below 27 weeks gestation, and occurred in 15% of very premature infants surviving 14 days or more. Cavities developed 15 days after the onset of periventricular echodensity (median time). Ventricular dilatation occurred in 24% of the infants who developed cavities. Follow up information was available in 27 infants and 18 of these (67%) had significant neurodevelopmental handicap. The location of echolucent cavities were described as involving anterior, middle or posterior cerebral zones or any combination of these. Cerebral palsy was closely related to the presence of cavities, but there was little association between cavities and developmental delay. Four factors were found to predict cerebral palsy: cavities within the occipital zone, the involvement of multiple regions of the brain, lesions greater than 1 cm in diameter and cavities associated with subcortical leukomalacia. Lesions confined to the anterior or middle zones were unlikely to be associated with significant handicap. The presence of cavities per se was not associated with a higher incidence of severe developmental delay.

Social criteria for evaluating population change: an alternative to the Blackorby-Donaldson criterion

"An ethical objection is raised against the Blackorby-Donaldson criterion of optimum population maximizing the sum total of utilities in excess of some critical level, since it may disprefer a social state with more people and with more worthwhile lives. However, the criterion may serve as a practicably reasonable compromise between maximizing total and average utility. Nevertheless, an alternative compromise (the maximization of number-dampened total utility) is proposed that is free from the above objection."