Hammerstein-Wiener Motion Artifact Correction for Functional Near-Infrared Spectroscopy: A Novel Inertial Measurement Unit-Based Technique.

Participant movement is a major source of artifacts in functional near-infrared spectroscopy (fNIRS) experiments. Mitigating the impact of motion artifacts (MAs) is crucial to estimate brain activity robustly. Here, we suggest and evaluate a novel application of the nonlinear Hammerstein-Wiener model to estimate and mitigate MAs in fNIRS signals from direct-movement recordings through IMU sensors mounted on the participant's head (head-IMU) and the fNIRS probe (probe-IMU). To this end, we analyzed the hemodynamic responses of single-channel oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) signals from 17 participants who performed a hand tapping task with different levels of concurrent head movement. Additionally, the tapping task was performed without head movements to estimate the ground-truth brain activation. We compared the performance of our novel approach with the probe-IMU and head-IMU to eight established methods (PCA, tPCA, spline, spline Savitzky-Golay, wavelet, CBSI, RLOESS, and WCBSI) on four quality metrics: SNR, △AUC, RMSE, and R. Our proposed nonlinear Hammerstein-Wiener method achieved the best SNR increase (p < 0.001) among all methods. Visual inspection revealed that our approach mitigated MA contaminations that other techniques could not remove effectively. MA correction quality was comparable with head- and probe-IMUs.

Improved Motion Artifact Correction in fNIRS Data by Combining Wavelet and Correlation-Based Signal Improvement.

Functional near-infrared spectroscopy (fNIRS) is an optical non-invasive neuroimaging technique that allows participants to move relatively freely. However, head movements frequently cause optode movements relative to the head, leading to motion artifacts (MA) in the measured signal. Here, we propose an improved algorithmic approach for MA correction that combines wavelet and correlation-based signal improvement (WCBSI). We compare its MA correction accuracy to multiple established correction approaches (spline interpolation, spline-Savitzky-Golay filter, principal component analysis, targeted principal component analysis, robust locally weighted regression smoothing filter, wavelet filter, and correlation-based signal improvement) on real data. Therefore, we measured brain activity in 20 participants performing a hand-tapping task and simultaneously moving their head to produce MAs at different levels of severity. In order to obtain a "ground truth" brain activation, we added a condition in which only the tapping task was performed. We compared the MA correction performance among the algorithms on four predefined metrics (R, RMSE, MAPE, and ΔAUC) and ranked the performances. The suggested WCBSI algorithm was the only one exceeding average performance (p < 0.001), and it had the highest probability to be the best ranked algorithm (78.8% probability). Together, our results indicate that among all algorithms tested, our suggested WCBSI approach performed consistently favorably across all measures.

Efficacy of erythritol powder air-polishing in active and supportive periodontal therapy: A systematic review and meta-analysis.

OBJECTIVE: This systematic review aimed to analyse available evidence to answer two focused questions about the efficacy of erythritol powder air-polishing (EPAP) (i) as an adjunctive during active periodontal therapy (APT) and (ii) as an alternative to hand/ultrasonic instrumentation during supportive periodontal therapy (SPT). Additionally, microbiological outcomes and patient's comfort/perceptions were assessed as secondary outcomes. METHODS: PubMed, Cochrane and Medline were searched for relevant articles published before February 2021 following PRISMA guidelines. The search was conducted by three independent reviewers, and the agreement was measured by Cohen's kappa score. Out of 1043 articles, eight randomized clinical trials were selected for systematic review and quantitative synthesis. Only periodontal parameters, such as clinical attachment level (CAL), probing pocket depth (PPD) and bleeding on probing (BoP), showed homogeneity and, thus, were selected for meta-analysis. RESULTS: The improvement in PPD and BoP scores after using EPAP was comparable with hand/ultrasonic instrumentation during both APT and SPT. Significant CAL gain was achieved with EPAP during APT (0.16 mm, p < 0.02) compared with hand/ultrasonic instrumentation at the end point, whereas non-significant CAL gain was achieved during SPT. No differences were observed regarding microbiological outcomes between the two treatment modalities. However, EPAP inflicted less pain and was better perceived by the patients. CONCLUSION: Erythritol powder air-polishing can substitute hand/ultrasonic instrumentation for SPT, and CAL gain is significantly improved when EPAP is used as an adjunct during APT. For microbiological outcomes, no significant differences were observed between the two approaches; however, EPAP was better tolerated by the patients than hand/ultrasonic instrumentation. CLINICAL RELEVANCE: Erythritol powder air-polishing can be used as an adjunct during APT and as an alternative to conventional mechanical debridement during SPT.

Oral health awareness, attitude towards dental treatment, fear of infection and economic impact during COVID-19 pandemic in the Middle East.

OBJECTIVES: To assess the impact of COVID-19 on oral hygiene (OH) awareness, attitude towards dental treatment, fear of infection and economic impact in the Middle East. METHODS: This survey was performed by online distribution of questionnaires in three countries in the Middle East (Jordan, Iraq and Egypt). The questionnaire consisted of five sections: the first section was aimed at collecting demographic data and the rest sections used to assess OH awareness, attitude towards dental treatment, degree of fear and economic impact of COVID-19. The answers were either multiple choice, closed-end (Yes or No) or 5-point Likert scale for the last four sections. RESULTS: A total of 3782 respondents completed the questionnaire. Overall, OH awareness was low (mean ±SD; 1.84 ± 1.03), while attitude towards dental treatment (5.04 ± 1.68) and economic impact (11.29 ± 4.37) were moderately affected. In addition, fear of infection showed moderately high level (14.04 ± 4.11). All subgroups of the demographic variables showed significant differences among them in relation to OH awareness and attitude towards dental treatment. The regression model suggested country, gender, age, education level, income level and fear as predictors for OH awareness (R2 0.036) and attitude towards dental care (R2 0.141). CONCLUSIONS: The pandemic negatively impacted the level of OH awareness. However, the attitude towards dental treatment was moderately affected. Increasing public fear and compromised economy influenced OH awareness and the attitude towards dental treatment.

A randomized double-blind clinical trial to evaluate the efficacy of chlorhexidine, antioxidant, and hyaluronic acid mouthwashes in the management of biofilm-induced gingivitis.

OBJECTIVES: To investigate the antiplaque and antigingivitis efficacy in addition to evaluating side effects and subjects' perceptions of three commercially available mouthwashes. METHODS: This study was a double-blind, parallel, and short-term trial. A total of 75 dental students with biofilm-induced gingivitis were included in the final analysis of the current study. Clinical parameters (plaque index and bleeding on probing) and the staining effect were measured at baseline and after 7 days. In addition, a VAS-based assessment questionnaire was completed by the participants. RESULTS: All interventions significantly reduced plaque scores, but chlorhexidine (CHX) had a significantly higher effect than the hyaluronic acid (HA) and antioxidant mouthwashes. However, all mouthwashes significantly reduced the total bleeding scores to <10% in 53% of the patients, compared to the baseline record. Additionally, teeth underwent shade changes in association with all interventions by the end of the study. Analysis of feedback about the mouthwashes showed that the participants seemed to prefer the HA mouthwash over the other mouthwashes. CONCLUSIONS: CHX remains the most effective antiplaque mouthwash although HA and antioxidants are as effective as CHX in reducing bleeding. In addition, based on its better acceptance by the participants, HA is potentially a good alternative to CHX.

Platelet-rich fibrin as an adjunct to scaling and root planing in treatment of shallow periodontal pockets: A randomized clinical trial.

OBJECTIVES: To evaluate the efficacy of platelet-rich fibrin (PRF) as an adjunct to scaling and root planing (ScRp) for healing shallow periodontal pockets. METHODS: Twelve patients with periodontitis were enrolled in this split-mouth, randomized clinical trial. A total of 24 shallow periodontal pockets (4-6 mm) were treated by either ScRp alone (control) or PRF (test). Clinical attachment loss (CAL), probing pocket depth (PPD), bleeding on probing (BOP), and plaque index (PLI), as well as platelet-derived growth factor-BB (PDGF-BB) by enzyme-linked immunosorbent assay (ELISA) in gingival crevicular fluid (GCF) were measured at baseline and at 1- and 3-month follow-up visits. RESULTS: At 1- and 3-month follow-up visits, greater CAL gains (2.6 ± 0.25 mm and 3.26 ± 0.31 mm, respectively) and PPD reductions (2.58 ± 0.38 and 3.31 ± 0.39 mm, respectively) were observed in the test group compared to those in controls (CAL gain of 1.01 ± 0.49 mm and 1.43 ± 0.48 mm; PPD reduction of 1.1 ± 0.55 and 1.37 ± 0.49 mm, respectively). In addition, the increase in PDGF-BB in GCF in the test group (724.5 ± 186.09 pg/µl and 1957.5 ± 472.9 pg/µl) was significantly greater than that in controls (109.3 ± 24.07 and 614.64 ± 209.3 pg/µl) at 1- and 3-month follow-up visits, respectively. CONCLUSIONS: The noninvasive use of PRF as an adjunct to ScRp successfully improved clinical periodontal parameters and might contribute to increased PDGF-BB in GCF.

Planning a sustainable neurosurgery mentorship program in a war-torn country: experience from Iraq.

The importance of mentorships in medical education and neurosurgery is highly attributed to the support and encouragement of the advances and learning opportunities for medical students and junior neurosurgeons. Planning a mentorship program according to the target audience offers to satisfy different interests and enhance education. One of the main issues with most of the already implemented programs is the sustainability and inability to maintain continuous cycles of mentorship, which have a negative impact and have led to an interrupted pattern of learning which eventually leads to a decline in the engagement of participants and loss of interest. This problem is most pronounced in war-torn countries, with Iraq as an example, where external circumstances lead to an arrest in the educational process and a depletion of the resources useful for such programs and training courses. This paper aims to address the main pathways essential in planning a sustainable mentorship program in a war-torn country by highlighting our experience in maintaining an ongoing mentorship with nine consecutive courses over the last 6 years in Iraq.

Teleproctoring in therapeutic neurointervention: Experience from Iraq-Saudi Arabia collaboration.

Background: Proctoring in neuroendovascular surgery is one of the potential solutions for the shortage of personnel and experience, particularly in unstable and limited-resource areas such as Iraq. Methods: The study was conducted at the Baghdad Neurovascular Center (BNC), the first Hybrid neurovascular institution in Iraq, where sequential online zoom-based meetings between the BNC team and the expert from the Kingdom of Saudi Arabia were used for teleproctoring for neurointerventional procedures. Results: A total of 28 sessions were conducted, four sessions for each case. Seven cases with various intracranial vascular lesions were operated for neuroendovascular procedures from July/2021 to March/2022. The teleproctoring for each case included four sequential sessions: (1) preoperative planning, (2) device selection and preparation, (3) intraoperative live-stream proctoring, and (4) postoperative reflection and follow-up planning. The procedures include coiling for dural arteriovenous fistula; preoperative tumor embolization; preoperative, partial, and staged embolization for arteriovenous malformation; coiling for intracranial aneurysm; and attempted Giant aneurysm flow-diversion. Major complications were avoided through teleproctoring, and all patients had good outcomes. In addition, the teleproctoring provided an effective training experience to the local neuroendovascular team that is otherwise not feasible. Conclusion: Teleproctoring is an effective and feasible tool to improve patient outcomes and provide a training experience to the local neuroendovascular teams in resource-limited regions.

Bilateral basal ganglia hemorrhage in a 2-year-old child.

Background: Basal ganglia hemorrhage (BGH) is an intracerebral subtype of hemorrhage located in the caudate nucleus, putamen, globus pallidus, or adjacent structures such as the thalamus or internal capsule. Bilateral involvement of both basal ganglia is exceedingly infrequent. Herein, we report a case of a 2-year-old female who was discovered to have spontaneous bilateral BGH with a unique hemorrhagic extension. Case Description: A 2-year-old female child who presented with a decreased level of consciousness, seizure, and fever was discovered to have bilateral BGH during imaging evaluation that extended from the head of the caudate to involve the putamen, globus pallidus, and anterior limb of the internal capsule. Conclusion: Bilateral BGH is extremely rare, and to the best of our knowledge, this is the first case report in pediatric age groups.

Synthesis, molecular docking and anti-inflammatory evaluation of new trisubstituted pyrazoline derivatives bearing benzenesulfonamide moiety.

A new series of trisubstituted pyrazoline bearing benzenesulfonamide moiety 6a,b-10a,b were designed, synthesised and evaluated for their anti-inflammatory in vitro. Before starting the synthesis, docking study has been used to insert compounds within the COX-2 structure active site using celecoxib drug as a reference. Final compounds 6a,b-10a,b were synthesised by condensing chalcones bearing pyridine moiety 1a,b-5a,b with 4-hydrazinyl benzenesulfonamide hydrochloride. In vitro, their anti-inflammatory activity was assessed using egg-white paw edema method, they showed moderate to strong inhibitory activity. Notably, Compounds 6a (29.78%), 7a (28.43%), 9a (27.92%) and 10a (27.92%) exhibited significant percentage inhibition at 300 min and results are comparable with percentage inhibition drug celecoxib (22.67%) and this result is highly agreement with docking scoring study.

Extensive tension pneumocephalus presented in the setting of a challenging etiology.

Background: Pneumocephalus (PNC) is a well-described consequence in postoperative settings and skull fractures that is usually self-limiting. It can get complicated into tension PNC on some rare occasions, leading to an intracranial mass effect. PNC was also reported after unintentional dural puncture throughout the epidural anesthesia process. However, tension PNC resulting from epidural anesthesia procedures is an extremely rare outcome that implies urgent intervention to relieve the tension within the brain. Here, we report a case of an extensive tension intraventricular PNC 2 days following an epidural anesthesia procedure for a femur fixation surgery. Case Description: A 23-year-old male presented to the emergency department with basal skull fractures and a femur fracture due to a motorcycle accident. His skull base fracture was managed conservatively then he underwent a femur fixation procedure under epidural anesthesia. Two days after, he developed a severe headache with a disturbed level of consciousness. Computed tomography of the brain revealed an extensive PNC that involved all the subarachnoid spaces down to the cervical region and compressing the cerebellum, which was not found in the initial imaging. The patient's status improved after the twist-drill burr-hole evacuation of air under the water seal. Conclusion: Extensive tension PNC can occur after traumatic brain injury, especially after epidural anesthesia. Such cases should gain high focus because they may differ from simple PNC regarding diagnosis, treatment, and follow-up.

More Laboratory Simulations-Fewer Brain Complications: Prospects from the First Neurosurgery Laboratory in Iraq.

BACKGROUND: The intensive training requirements needed to achieve the requisiste microneurosurgical milestones makes proper training and skill acquisition a challenge to the novice neurosurgeon. This problem is compounded in low- and middle-income nations, where neurosurgery is subject to a myriad of human and financial resource constraints. A temporary solution may be provided by low-cost laboratories that are adaptive to local needs. METHODS: The "HOZ NeuroSurgery LAB" is a nonprofit facility dedicated to microneurosurgery education and skills training. The laboratory, established in June 2015, is housed at the Neurosurgery Teaching Hospital in Baghdad, Iraq. It operates under the motto "More Laboratory Simulation-Fewer Brain Complications.". The fundamental infrastructure of the facility consists of a relatively inexpensive microscope, indigenous locally created training equipment, and animal-based models. RESULTS: Since its inception, this lab has functioned as a hub for resident education and microneurosurgery service, in addition to contributing to the specialty's academic output in the nation. The lab is directly responsible for training 4 vascular neurosurgeons who are currently directing the nation's first organized neurovascular service. Also, it has delivered 53 microneurosurgery skills courses, coordinated 8 student neurosurgery elective cycles with a total of 532 participants, and published approximately 70 research articles. CONCLUSIONS: Our experience may serve as a model for other low- and middle-income countries interested in using the principle of "doing more with less" to overcome some of the challenges associated with microneurosurgery in these parts of the world.

Atypical slow-flow paramedian AVM with venous varix.

Background: Cerebral arteriovenous malformations (CAVMs) are either clinically silent or symptomatic. The most common presentation in more than half of all CAVMs presenting patients is hemorrhage which is accompanied by long-standing neurological morbidity and mortality. This report presents a case of an atypical large, slow-flow paramedian AVM with a dilated venous varix managed with surgery. The impact of the intraoperative findings on the diagnosis and the operative technique will be discussed. Case Description: In otherwise, healthy 26-year-old male complained of repeated episodes of generalized seizures and loss of consciousness. Brain magnetic resonance imaging (MRI) revealed a right parietal paramedian arteriovenous malformation (AVM) with signs of an old hemorrhagic cavity beneath it. Digital subtraction angiography demonstrated a slow-filling AVM with dilated venous varix drains into the superior sagittal sinus. However, the exact point of drainage cannot be appreciated. The filling of the AVM occurred precisely with the beginning of the venous phase. Intraoperatively, we noticed a whitish spherical mass, thick hemosiderin tissue, and a large cavity below the nidus; then, a complication-free complete microsurgical resection of this high-grade AVM was performed. Postoperatively, the patient suffered two attacks of seizures in the first few hours after the surgery, for which he received antiepileptics. MRI was clear during follow-up, and the patient was seizure-free and neurologically intact. Conclusion: Parietal convexity AVMs are challenging lesions to tackle. However, the chronicity and the slow-filling of the AVM, in this case, can render the surgical pathway more direct and accessible.

Extracranial carotid localized fibromuscular dysplasia: A case report and literature review.

Background: Fibromuscular dysplasia (FMD) is a noninflammatory and nonatherosclerotic arteriopathy that is characterized by irregular cellular proliferation and deformed construction of the arterial wall that causes segmentation, constriction, or aneurysm in the intermediate-sized arteries. The incidence of FMD is 0.42-3.4%, and the unilateral occurrence is even rarer. Herein, we report a rare case of a localized extracranial carotid unilateral FMD associated with recurrent transient ischemic attacks (TIAs) treated by extracranial-intracranial bypass for indirect revascularization. The specific localization of the disease rendered our case unique. Methods: We conducted a review of the PubMed Medline database search using the following combined formula: ((FMD [Title/Abstract]) AND ((isolated [Title/Abstract]) OR (localized [Title/Abstract]))) AND Internal carotid artery (ICA) (Title/Abstract). Additional resources were included by screening the reference list of the selected papers. Results: A total of six cases were found, and all accounted for localized FMD affecting the ICA. The age range was between 19 and 52, the male-to-female ratio was (2:4), and all of the cases consisted of unilateral carotid FMD, mainly on the left side with a left-to-right ratio of 5:1. The management and outcome of these cases varied according to the case and associated complications. Conclusion: Extracranial localized FMD of the ICA is a rare subtype of FMD that has little documentation in the literature. In our case, it was a localized extracranial carotid unilateral FMD associated with recurrent TIAs. The appropriate treatment was using the intracranial-extracranial bypass.

Analysis of the molecular and biological variability of Zucchini yellow mosaic virus isolates from Iran and Iraq.

During the growing season of 2018, several field-grown cucurbit plants in different parts of Iraq and Iran were surveyed for the presence of zucchini yellow mosaic virus (ZYMV), using two degenerate primer pairs (CIF/Rev and NIb2F/3R) targeting the two separated partial regions of the potyvirus genome (CI and NIb respectively). 7 out of 20 samples were confirmed to be infected with ZYMV. Phylogenetic analyses based on the CI gene grouped all Iranian and two Iraqi (ZYMV1 and ZYMV2) isolates together with isolates from the Middle East in the subgroup (AI), whereas the other Iraqi (ZYMV3 and ZYMV4) isolates were clustered in the subgroup (DI), which was only consisted of American isolates. The highest and lowest identity between the studied isolates and the GenBank isolates showed that the two genes (CI, NIb) of each isolate particularly the Iraqi isolates were more similar to a specific and geographically scattered mosaic of worldwide isolates, suggestive of mixed infection might have occurred between different worldwide isolates in Iraq. Furthermore, the first complete nucleotide sequence of an Iraqi ZYMV (ZYMV-Iq) isolate was done, using the Illumina sequencing technique. The complete nucleotide sequence of ZYMV-Iq isolate was 9650 nt, excluding the 3'poly (A) tail. ZYMV-Iq isolate shared the highest nt identity of 98.8% with an American (KC665630) isolate. Phylogenetic analysis based on the full genome sequence placed ZYMV-Iq in subgroup A of group I alongside 18 isolates from the US and two isolates from Australia. In addition, recombination analysis detected lone significant recombination between ZYMV-Iq and South Korean (AY279000) isolate. Moreover, the results showed that symptom intensity was varied across experimental host plants.

Evaluation of treatment of acne scars with 25% trichloroacetic acid chemical peel followed by manual dermasanding.

BACKGROUND: Acne scars are common problems encountered in daily dermatologic practice. AIMS: To evaluate the effectiveness and safety of 25% trichloroacetic acid (TCA) alone or followed by manual dermasanding in repeated sessions for the treatment of mild and moderate acne scars. PATIENTS/METHODS: Thirteen patients (nine females and four males) were enrolled. Twenty-five percent TCA superficial peel was performed in all patients, followed in 11 of them by manual dermasanding. Thirteen sessions of TCA peeling, one session for each patient, were done, and twenty-four sessions of dermasanding with different numbers for each patient. Acne scars were graded into a score ranging from 0 to 20, the score was recorded at each visit, and the results were compared. RESULTS: The score of scarring acne decreased after TCA peeling and each dermasanding session. The improvement was statistically significant. The improvement continued after the last dermasanding session. After both procedures, no significant complications were recorded except persistent erythema and post-inflammatory hyperpigmentation, which disappeared in all patients at 3-month follow-up visit. CONCLUSION: Trichloroacetic acid superficial peel followed by manual dermasanding in separate sessions was effective and the improvement became more significant after repeated dermasanding sessions for the treatment of mild and moderate acne scars.

Whole genome characterization of wisteria vein mosaic virus from Iran and its relationship to other members of bean common mosaic virus group.

To date, the complete genome of two wisteria vein mosaic virus (WVMV) has been sequenced worldwide. Here, the genomic sequence of WVMV isolated from Wisteria sinensis in Iran was determined for the first time, using deep RNA sequencing and RT-PCR followed by Sanger sequencing. The sequence was 9694 nucleotides in length; excluding the 3'-poly(A) tail and contained a single open reading frame of 9279 nucleotides encoding a large polyprotein of 3092 amino acids and predicted molecular weight of 35,368 KDa. The genome contained nine putative proteolytic cleavage sites and motifs conserved in homologous proteins of other potyviruses. Sequence analysis suggested that WVMV-Ir sequence shared 76.37-86.01% nucleotide (nt) identity and 82.45-91.91% amino acid (aa) identity with two other isolates (Beijing and JEBU-p) available in the GenBank, the highest with the Chinese isolate Beijing (86.01% nt identity, 91.91% aa identity). Sequence identities over most of the genome were within the range 80-86% and 85-95% at the nt and aa levels, respectively; however, high variability was observed in the 5'-UTR (51.62%), P1 (62.03% nt identity, 50.78% aa identity) and P3 (79.82%nt identity, 78.67% aa identity) regions, suggesting that Ir, Beijing, and JEBU-p are three different strains. These variabilities may be due to different mutation phenomena of a common ancestor virus or mutations caused by different selection pressures in different agro-ecological regions. The results of the phylogenetic analysis indicated that WVMV was most closely related to soybean mosaic virus and watermelon mosaic virus and less closely related to the zantedeschia mild mosaic virus and dasheen mosaic virus. In the greenhouse, WVMV-Ir caused severe symptoms in Phaseolus vulgaris, Vicia faba, W. sinensis, Chenopodium quinoa, C. amaranticolor, and Nicotiana benthamiana. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02957-8.

Dentists' Practices and Attitudes Toward Using Personal Protection Equipment and Associated Drawbacks and Cost Implications During the COVID-19 Pandemic.

Objectives: During the COVID-19 pandemic, dentists have had to work under stressful conditions due to the nature of their work. Personal protection equipment (PPE) has become mandatory for work in the dentistry field. This study aimed to examine dentists' practices and attitudes regarding the use of PPE and the associated drawbacks and cost implications during the pandemic. Methods: A questionnaire-based survey was used and was divided into five sections dedicated to collect demographic variables and to examine the dentists' practices, attitudes toward PPE, drawbacks, and cost of using PPE. Mann-Whitney U and Kruskal-Wallis tests were used to compare different sections of the questionnaire and linear regression was used to determine the predictors of the dentists' practices and attitudes toward PPE. Results: The mean of practices regarding use of PPE was 5.41 ± 1.71 (median 6), attitude toward using PPE scored 2.26 ± 0.90 (median 2), while the means of drawbacks and cost recorded equal scores of 5.22 ± 1.24 (median 5) and 1.68 ± 0.74 (median 2), respectively. The recently graduated dentists, those with postgraduate degrees and those working in the private sector demonstrated higher levels of practices on PPE than their counterparts. Regression analysis revealed that practices of PPE can be predicted on the basis of qualifications and work place, whereas attitude toward PPE is significantly influenced by qualification only. Conclusions: The study participants demonstrated satisfactory levels of practices and positive attitudes toward PPE. While complaints from using PPE and their cost were moderately affected.

In Vitro Homeostasis of Rat Oral Epithelial Cell Cultures Following Withdrawal of Periodontal Pathogens.

Inflammation of periodontal tissues is the consequence of interaction between periodontal pathogens and immune system. This is associated with increased expression of inflammatory cytokines, which may exert destructive effect to the periodontal tissues when released over long period. The aim of this study was to chronologically track the homeostasis of oral keratinocytes following removal of periodontal pathogens. This was done by investigating expression of selected inflammatory markers and integrity of epithelial monolayers in vitro. Rat oral keratinocytes were stimulated with heat-killed Fusobacterium nucleatum and Porphyromonas gingivalis over 7-days then bacteria were washed away and epithelial cells re-cultured for 3-days. Expression of IL-1ß, IL-6, and IL-8 was measured by ELISA while transcription of tissue inhibitor of metalloproteinase-1 (TIMP-1) and matrix metalloproteinase -8 (MMP-8) was measured by polymerase chain reaction before and after removal of bacteria. Integrity of epithelial sheet was investigated by using transepithelial electrical resistance. Data showed general downregulation of IL-1b, IL-6, and IL-8 associated with restoring transcription of TIMP-1 and MMP-8 to normal level following removal of bacteria from epithelial cultures. However, expression of IL-8 and MMP-8 remained significantly higher than unstimulated epithelial cells despite withdrawal of F. nucleatum and P. gingivalis respectively from oral keratinocytes cultures. In addition, integrity of epithelial barrier function remained compromised even after removal of P. gingivalis. Results suggest that even after three days following removal of periodontal pathogens, oral keratinocytes sustained persistent upregulation of certain inflammatory markers that could compromise integrity of epithelial barrier function.