Development of a pseudo-typed virus particle based method to determine the efficacy of virucidal agents

The ongoing Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic has highlighted the threat that viral outbreaks pose to global health. A key tool in the arsenal to prevent and control viral disease outbreaks is disinfection of equipment and surfaces with formulations that contain virucidal agents (VA). However, assessment of the efficacy of virus inactivation often requires live virus assays or surrogate viruses such as Modified Vaccinia Virus Ankara (MVA), which can be expensive, time consuming and technically challenging. Therefore, we have developed a pseudo-typed virus (PV) based approach to assess the inactivation of enveloped viruses with a fast and quantitative output that can be adapted to emerging viruses. Additionally, we have developed a method to completely remove the cytotoxicity of virucidal agents while retaining the required sensitivity to measure PV infectivity. Our results indicated that the removal of cytotoxicity was an essential step to accurately measure virus inactivation. Further, we demonstrated that there was no difference in susceptibility to virus inactivation between PVs that express the envelopes of HIV-1, SARS-CoV-2, and Influenza A/Indonesia. Therefore, we have developed an effective and safe alternative to live virus assays that enables the rapid assessment of virucidal activity for the development and optimization of virucidal reagents.

Multi-modal neuroimaging signatures predict cognitive decline in multiple sclerosis: A 5-year longitudinal study

BACKGROUND

Cognitive impairment is a hallmark of multiple sclerosis (MS) but is usually an under-recorded symptom of disease progression. Identifying the predictive signatures of cognitive decline in people with MS (pwMS) over time is important to ensure effective preventative treatment strategies. Structural and functional brain characteristics as measured by various magnetic resonance (MR) methods have been correlated with variation in cognitive function in MS, but typically these studies are limited to a single MR modality and/or are cross-sectional designs. Here we assess the predictive value of multiple different MR modalities in relation to cognitive decline in pwMS over 5 years.

METHODS

A cohort of 43 pwMS was assessed at baseline and 5 years follow-up. Baseline (input) data consisted of 70 multi-modal MRI measures for different brain regions including magnetic resonance spectroscopy (MRS), diffusion tensor imaging (DTI) and standard volumetrics. Age, sex, disease duration and treatment were included as clinical inputs. Cognitive function was assessed using the Audio Recorded Cognitive Screen (ARCS) and the Symbol Digit Modalities Test (SDMT). Prediction modelling was performed using the machine learning package - GLMnet, where a penalised regression was applied to identify multi-modal signatures with the most predictive value (and the least error) for each outcome.

RESULTS

The multi-modal approach to neuroimaging was able to accurately predict cognitive decline in pwMS. The best performing model for change in total ARCS (tARCS) included 16 features from across the various MR modalities and explained 54 % of the variation in change over time (R2=0.54, 95 % CI=0.48-0.51). The features included nine MRS, four volumetric and two DTI parameters. The model also selected disease duration, but not treatment, as a predictive feature. By comparison, the best model for SDMT included several of the same above features and explained 39 % of the change over time (R2=0.39, 95 % CI=0.48-0.51). Conventional volumetric measures were about half as good at predicting change in tARCS score compared to the best multi-modal model (R2=0.26 95 % CI:0.22-0.29). The clinical interpretation of the best predictive model for change in tARCS showed that cognitive decline could be predicted with >90 % accuracy in this cohort (AUC=0.92, SE=0.86 - 0.94).

CONCLUSION

Multi-modal MRI signatures can predict cognitive decline in a cohort of pwMS over 5 years with high accuracy. Future studies will benefit from the inclusion of even more MR modalities e.g., functional MRI, quantitative susceptibility mapping, magnetisation transfer imaging, as well as other potential predictors e.g., genetic and environmental factors. With further validation, this signature could be used in future trials with high-risk patients to personalise the management of cognitive decline in pwMS, even in the absence of relapses.

Comparative Evaluation of Various Lens and Ring Flash Combination for Intraoral Photography

BACKGROUND

Extraoral and intraoral dental photographs serve as preoperative records and document the entire treatment. Correctly composed orthodontic photographs are crucial for remote diagnosis and may serve as a bulwark against medicolegal challenges.

MATERIALS AND METHODS

In this prospective study, intraoral frontal photographs of patients with ideal occlusion were taken using two types of lenses (EF-S 18-55 mm f/3.5-5.6 IS STM lens (Canon, Tokyo, JP), SP 90 mm F/2.8 MACRO VC lens (Model F017 Tamron, NY, USA)) and two different ring flash systems (Meike FC-100 Macro Ring LED Light (Meike, China), Macro Ring flash Lite YN-14EX (Yongnuo digital, China)). The combination of lens and flash used was grouped into four groups. Twenty-eight intraoral photographs of patients were taken. An image quality assessment survey was distributed among two groups - 50 orthodontists and 50 other dental specialists.

RESULTS

The participants were asked to assess all the intraoral images and subjectively score them on a scale of one to ten, with one being very poor and ten being excellent, considering the sharpness, color, brightness, contrast, and overall quality of the image. The general dentists rated the images taken with a 90-mm macro lens and ring flash as the best quality photographs. Images obtained using an 18-55 mm lens and ring LED received significantly lesser scores and were graded good by dentists.

CONCLUSION

This combination of lens and flash may prove a valuable investment in the long-term aiding in excellent dental images for diagnosis and treatment monitoring.

Quantifying neutralising antibody responses against SARS-CoV-2 in dried blood spots (DBS) and paired sera

The ongoing SARS-CoV-2 pandemic was initially managed by non-pharmaceutical interventions such as diagnostic testing, isolation of positive cases, physical distancing and lockdowns. The advent of vaccines has provided crucial protection against SARS-CoV-2. Neutralising antibody (nAb) responses are a key correlate of protection, and therefore measuring nAb responses is essential for monitoring vaccine efficacy. Fingerstick dried blood spots (DBS) are ideal for use in large-scale sero-surveillance because they are inexpensive, offer the option of self-collection and can be transported and stored at ambient temperatures. Such advantages also make DBS appealing to use in resource-limited settings and in potential future pandemics. In this study, nAb responses in sera, venous blood and fingerstick blood stored on filter paper were measured. Samples were collected from SARS-CoV-2 acutely infected individuals, SARS-CoV-2 convalescent individuals and SARS-CoV-2 vaccinated individuals. Good agreement was observed between the nAb responses measured in eluted DBS and paired sera. Stability of nAb responses was also observed in sera stored on filter paper at room temperature for 28 days. Overall, this study provides support for the use of filter paper as a viable sample collection method to study nAb responses.

Evaluation of scanning accuracy for two commercially available intraoral scanners in reproducing orthodontic bracket dimensions

OBJECTIVE

The aim of this study was to compare the scanning accuracy of two different intra-oral scanners- MEDIT i500 and TRIOS 3 shape in reproducing orthodontic bracket dimensions.

MATERIALS AND METHODS

This in vivo cross-sectional study comprised seven subjects with a full complement of permanent dentition without third molars. Complete arch scanning was carried out with two intraoral scanners, such as MEDIT i500, TRIOS 3 shape, after bonding with brackets. The control group consisted of bracket dimensions measured directly by using Vernier calipers before bonding. Bracket dimensions of three-dimensional (3D) images were measured by using OrthoAnalyzer software. The accuracy of intraoral scanning was investigated by comparing bracket dimensions among the three groups using One-way ANOVA and Post-Hoc Tukey HSD test, and by evaluating outcomes for each quadrant and an individual tooth in complete-arch scans.

RESULTS

When comparing bracket dimensions of 3D images with manual measurements using a traditional Vernier caliper, MEDIT i500 showed no significant difference when compared to the control group (p>0.05) in full arch scanning as well as the quadrant and single tooth scans in complete arch scanning. TRIOS 3 shape showed a significant difference when compared to the control and MEDIT i500 group (p<0.05) for all parameters.

CONCLUSIONS

MEDIT i500 showed higher accuracy and better reproduction of orthodontic bracket dimensions than TRIOS 3 shape.

Time Frame Analysis of Potassium Nitrate and Hydrogen Peroxide Diffusion into the Pulp Chamber

OBJECTIVES

The primary objective of this study was to evaluate the effect of an innovative double-layer, single-application desensitizing/whitening technique of potassium nitrate (PN) and hydrogen peroxide (HP) diffusion at different time points.

METHODS AND MATERIALS

Specimens were prepared from extracted caries-free human molars (n=90). Teeth were randomly assigned into four groups: Group A (HP CTRL) treated with 25% HP for 45 minutes, group B (PN CTRL) received a single-layer treatment of 5% PN for 45 minutes, group C received the double-layer treatment of 5% PN and 25% HP for 45 minutes, and group D received a 3% PN incorporated in a 40% HP gel for 45 minutes. PN and HP concentrations were measured at 5, 15, 30, and 45 minutes using standard chemical kits. Group comparisons were made using a repeated measures analysis of variance (ANOVA) test. Pairwise tests for differences in diffusion were done, using the Tukey adjustment of p values for multiple comparisons. A significance level of 5% was used.

RESULTS

Group A showed no significant difference in HP diffusion rates between the 5- and 15- minute, 15- and 30-minute, or 30- and 45-minute time points; group D showed a similar trend; however, group C differed significantly at the 5-and 15-minute time points (p=0.0004), at the 15-and 30-minute time points (p=0.0026), and the 30- and 45-minute time points (p=0.0014). For PN diffusion, groups B and C had significantly different levels at the 15-, 30-, and 45-minute time points (p=0.0005, p=0.0002, and p<0.0001, respectively); and at the 15-, 30-, and 45-minute time points, groups D and C had significantly different PN diffusion (p=0.0327, p=0.0004, and p< 0.0001, respectively). Group C had significantly different PN diffusion at the 5- and 15-minute time points (p=0.0004), the 15- and 30-minute time points (p=0.0026), and at the 30- and 45-minute time points (p=0.0014).

CONCLUSION

The double-layer technique showed superior diffusion of PN into the pulp chamber and did not affect the diffusion of HP when compared to other techniques. The double-layer technique may be suggested as an alternative tooth-whitening treatment to minimize tooth sensitivity.

Comparative assessment of periodontal treatment needs among the electronic cigarette users and traditional smokers

OBJECTIVE

It is currently presumptuous that electric cigarettes are less harmful than the conventional ones; this is increasing the consumption of electric cigarettes. Therefore, this study intended to evaluate the periodontal treatment needs among conventional smokers, electronic cigarette smokers and non-smokers. This cross-sectional designed study involved 150 patients with a mean age of 29.88±7.81 years.

PATIENTS AND METHODS

Among all patients, 50 patients were recruited in each group. The periodontal condition and the treatment need for the patients were assessed using the community periodontal index treatment need (CPITN). Fisher exact test was used to find the significant association of all three groups with the periodontal status and the treatment need. Female patients (12.5%) showed better periodontal status than the male patients (87.5%) and required less complicated periodontal treatment independently from smoking type.

RESULTS

Furthermore, deeper pocket depth ≥6 mm (75%) has been found among the conventional cigarette smokers whereas the majority of the electric cigarette smokers (50%) have calculus deposition. Thus, 50% of the electric smokers require professional scaling whereas 57.1% of conventional smokers prerequisite complex periodontal treatment.

CONCLUSIONS

Besides, there was a significant difference (p≤0.05) observed among all groups in periodontal health index and treatment need. Conventional cigarette consumers need more complicated periodontal treatment compared to the patients who consume electric cigarettes.

Effect of honey dressing material on palatal wound healing after harvesting a free gingival graft: a prospective randomized case control study

OBJECTIVE

The aim of this prospective randomized case-control study was to understand the clinical benefits and effect of honey as a dressing material on palatal wound healing after harvesting free gingival graft (FGG).

PATIENTS AND METHODS

This prospective randomized case-control study was conducted on a sample of 20 patients with 10 patients in each group. Medihoney dressing material was applied to the donor site in the test group, whereas no dressing material was applied to the control group. All the patients received the same medication (Ibuprofen 600 mg) and post-operative instructions straight away after the surgical procedure. Patients were given the follow-up appointment at first, second and fourth week after the surgery during which the length and the width of the donor site was measured and recorded.

RESULTS

At first week, a significant difference in the proportion of patients showing the healing of donor site percentage was found to be 56% (both in width and length) for test group vs. 44% (both in width and length) for the control group (p=0.001). At 4-week, the healing of donor site percentage was found to be 86% (in width) and 91% (in length) for test group vs. 14% (in width) and 9% (in length) for the control group, the difference being statistically significant (p=0.001).

CONCLUSIONS

The result of this current study suggests that the honey dressing material accelerated the wound healing process of the palatal wound after harvesting FGG. It also showed a shorter recovery period along with less post-operative morbidity.

Translation and validation of the “Smell Diskettes” Olfaction Test into Arabic

Objective: This study aims to translate and validate the 'Smell Diskettes' screening tool from English into Arabic. The significance of this study stems from the lack of reliable and rapid olfaction screening tests available to Arabic speaking patients and healthcare practitioners. Methods: This is a prospective cohort, multi-center study. A forward-backward translation of the olfaction screening test was done to translate the text into Arabic. Data was collected from two groups: a control group (n=125) of which 84 percent were females (n=105) and a mean age of 22.4 of subjectively normosmic individuals from Alfaisal University and a patients group (n=82) of which 35.4 percent females (n = 29) with a mean age of 38.2, all of whom were diagnosed with olfactory disturbances related to rhinological pathologies, from King Abdulaziz University Hospital (KAUH) in Riyadh, Saudi Arabia. One of the limitations we faced due to convenience sampling and COVID-19 pandemic restrictions was the inability to perform a “test-retest” on study subjects. Results: The study included 207 subjects, out of whom 82 (40 percent) were patients from the rhinology clinic at King Abdulaziz University Hospital (KAUH) and 125 (60 percent) were recruited as controls from Alfaisal University. The average olfaction scores for the control group and the patients’ group were 7/8 and 5/8, respectively. Conclusion: This study has determined that the Arabic-language version is a valid and useful instrument used in clinical practice and for research purposes. The development of this tool will allow more patients in Arabic-speaking countries to be screened for olfactory disturbances.

Neonatal plastibell circumcision: does the thread type matter? a prospective randomized study

INTRODUCTION

Plastibell is one of the most common disposable devices used for circumcision. The study aims to determine whether changing the thread type from cotton to polypropylene to tie around the Plastibell in neonatal circumcision would result in faster separation of the ring.

PATIENTS AND METHODS

Prospective, randomized, clinical and biomechanical studies were performed. All circumcisions were performed by a single surgeon. Data collected included anthropometric measures, demographic data, procedure time, complications, parent satisfaction, follow-up, and outcomes. The biomechanical study measured the tensile properties of both threads using a universal testing machine (4465; Instron, Norwood, MA).

RESULTS

Two hundred full-term, male neonates aged between 24 and 48 h were circumcised using Plastibell. Both groups were similar in gestational age, age at circumcision, body weight, height, head circumference, Apgar score at 1 and 5 min, procedure time, Plastibell size, and parent satisfaction. The subjects were randomized into two groups of 100 neonates each: group I where Plastibell was tied by a cotton thread supplied by the manufacturer and group II where Plastibell was tied by Polypropylene 0. The mean duration for Plastibell fall-off was 8.98 days and 7.74 days in cotton thread and Polypropylene 0, respectively (P-value < 0.001). There was no difference regarding the complications for both groups. The diameters of the cotton and Polypropylene 0 threads were 0.68 mm and 0.35 mm, respectively. The measured tensile strengths of cotton and Polypropylene thread were 180 MPa and 457 MPa, respectively.

CONCLUSION

Plastibell tied by Polypropylene 0 fell off faster than that tied by cotton thread, with no significant differences in adverse effects or complications. This finding might be relevant for anxious parents and caregivers. Further studies are needed to examine other types and sizes of threads to investigate whether this separation period can be reduced further.