A simple technical innovation to prevent needle stick injuries among dental professionals

OBJECTIVE

Dental healthcare personnel face the potential danger of being exposed to infectious patients while administering local anesthesia injections during dental operations. This could lead to unintentional transfer of infectious diseases from patients to physicians. Although safety measures such as the One-hand-scoop technique and the use of safety syringes, plastic needle cap holders, and needles with safety caps are in place, there have been instances of needle stick injuries reported in clinics. This might be due to the lack of adherence to conventional safety measures or the impracticality of safety techniques and safety syringes. This article aims to demonstrate the utilization of dental tweezers, specifically London College tweezers or dental forceps, for the secure recapping of needles, eliminating the requirement for extra equipment or devices.

SUBJECTS AND METHODS

After obtaining ethical approval (Approval No.: 024-01-2024) from the College of Dentistry, Dar Al Uloom University, 67 dental professionals, with consent for participation in the study, were included. They were requested to use dental tweezers/London College tweezers and dental extraction forceps such as maxillary anterior, mandibular anterior, and maxillary bayonet root forceps individually to recap the local anesthetic needles. The efficacy of these techniques was evaluated against the one-hand scoop technique for its ease, convenience, and reliability in preventing needle stick injuries.

RESULTS

The evaluation of dental professionals regarding the ease of using dental tweezers to recap needles, compared to the one-hand scoop technique (p=0.592), maxillary bayonet root forceps (p=0.746), mandibular anterior forceps (p=0.380), and maxillary anterior forceps (p=0.808), did not yield statistically significant results. The assessment of the procedural simplicity of the one-hand scoop technique showed a satisfaction rate of over 40%, whereas the application of dental tweezers resulted in a satisfaction rate of 30%. However, the use of dental tweezers for needle recapping resulted in a satisfaction rate of over 50%, compared to a satisfaction rate of 30% for the one-handed scoop technique.

CONCLUSIONS

There is no statistically significant difference in the assessment of the efficacy of dental tweezers and the one-hand scoop technique, bayonet root forceps, mandibular anterior forceps, maxillary anterior forceps, and dental tweezers for the needle capping technique. Therefore, dental forceps can be used instead of the one-handed scoop approach. The needle recapping procedure outlined in our study, aimed at preventing needle stick injuries, is simple to implement, and all dental specialties have convenient access to the required instruments.

Perspectives and challenges in lip rejuvenation: a systematic review

OBJECTIVE

There is an abundance of information on facelifts, blepharoplasties, rhinoplasty, and other cosmetic surgical procedures for the upper third of the face, but little is known about perioral lip rejuvenation. The aim of this article is to examine the existing literature on lip rejuvenation and perioral procedures related to lip rejuvenation. Additionally, this article aims to highlight the importance of addressing perioral areas alongside lip rejuvenation procedures, rather than solely focusing on lip rejuvenation. We also discussed the extensive procedures and materials used for lip rejuvenation, such as hyaluronic acid, botulinum toxin A, abobotulinum, onabotulinum, incobotulinum, prabobotulinum, fat grafts, silicone fillers, human collagen, collagen stimulating procedures such as derma pens and derma rolls, radiation frequency, stem cells, and plasma therapy, as well as the underlying factors that contribute to varying success rates.

MATERIALS AND METHODS

A thorough literature search was done using PubMed, Cochrane, Ebsco search, Google Scholar, Scopus, and Web of Science for the articles pertaining to facial and lip cosmetic surgeries 1995-2020. Keywords for the search included anatomy of the face, facial aging, perioral areas, lip rejuvenation, botox, grafts, facelift, plastic surgery, stem cell therapy, plasma treatment, and cosmetic surgery.

RESULTS

37 articles met the study criteria. 14 out of 37 studies included procedures for lip and perioral region rejuvenation. The remaining 23 studies either involved lip procedures alone or lip procedures in conjunction with facial cosmetic procedures. Lip rejuvenation with perioral enhancement with hyaluronic acid gel demonstrated a 94.3% improvement on the lip fullness scale (LFS) one month after re-treatment. The amalgamation of lip and perioral region rejuvenation produces a synergistic effect. Whereas, sole lip rejuvenation procedures showed short-term results with less patient satisfaction, calling for secondary lip rejuvenation procedures. It was also observed that hyaluronic acid was the most commonly used agent for lip rejuvenation procedures with minimal or no side effects.

CONCLUSIONS

In conjunction with perioral rejuvenation, lip rejuvenation procedures produce more aesthetically appealing results. However, any cosmetic surgical or non-surgical procedure is limited by the nature and composition of the products used. The use of FDA-approved products for rejuvenation is strongly advised to avoid undesirable side effects. Further extensive research is required on the long-term outcomes and adverse effects of stem cell transplants, such as tumor development.

Synthesis, DNA binding and biological evaluation of benzimidazole Schiff base ligands and their metal(ii) complexes

Two novel benzimidazole ligands (E)-2-((4-(1H-benzo[d]imidazole-2-yl)phenylimino)methyl)-6-bromo-4-chlorophenol (L₁) and (E)-1-((4-(1H-benzo[d]imidazole-2-yl)phenylimino)methyl)naphthalene-2-ol (L₂) with their corresponding Cu(ii), Ni(ii), Pd(ii) and Zn(ii) complexes were designed and synthesized. The compounds were characterized by elemental, IR, and NMR (¹H & ¹³C) spectral analyses. Molecular masses were determined by ESI-mass spectrometry, and the structure of ligand L₁ was confirmed by single crystal X-ray diffraction analysis. Molecular docking was carried out for the theoretical investigation of DNA binding interactions. The results obtained were verified experimentally by UV/Visible absorption spectroscopy in conjunction with DNA thermal denaturation studies. It was observed that ligands (L₁ and L₂) and complexes (1-8) were moderate to strong DNA binders, as evident from the binding constants (K _b). The value was found to be highest for complex 2 (3.27 × 10⁵ M^-1) and lowest for 5 (6.40 × 10³ M^-1). A cell line study revealed that breast cancer cells were less viable to the synthesized compounds compared to that of standard drugs, cisplatin and doxorubicin, at the same concentration. The compounds were also screened for in vitro antibacterial activity for which complex 2 showed a promising broad-spectrum effect against all tested strains of bacteria, almost in the proximity of the reference drug kanamycin, while the rest of the compounds displayed activity against selected strains.

Image segmentation for neuroscience: lymphatics

A recent discovery in neuroscience prompts the need for innovation in image analysis. Neuroscientists have discovered the existence of meningeal lymphatic vessels in the brain and have shown their importance in preventing cognitive decline in mouse models of Alzheimer’s disease. With age, lymphatic vessels narrow and poorly drain cerebrospinal fluid, leading to plaque accumulation, a marker for Alzheimer’s disease. The detection of vessel boundaries and width are performed by hand in current practice and thereby suffer from high error rates and potential observer bias. The existing vessel segmentation methods are dependent on user-defined initialization, which is time-consuming and difficult to achieve in practice due to high amounts of background clutter and noise. This work proposes a level set segmentation method featuring hierarchical matting, LyMPhi, to predetermine foreground and background regions. The level set force field is modulated by the foreground information computed by matting, while also constraining the segmentation contour to be smooth. Segmentation output from this method has a higher overall Dice coefficient and boundary F1-score compared to that of competing algorithms. The algorithms are tested on real and synthetic data generated by our novel shape deformation based approach. LyMPhi is also shown to be more stable under different initial conditions as compared to existing level set segmentation methods. Finally, statistical analysis on manual segmentation is performed to prove the variation and disagreement between three annotators.

Biological activity tuning of antibacterial urotropine via co-crystallization: synthesis, biological activity evaluation and computational insight

Urotropine (1) is a synthetic heterocyclic antibacterial agent.

Synthesis, crystal structures, Hirshfeld surface analysis and spectroscopic studies of two Schiff bases of anisaldehyde and their urease and acetylcholinesterase inhibitory and antioxidant properties

The growing demand of pharmaceutical industry for more effective drugs requires new molecules with promising medicinal activities. In the present work, a natural product anisaldehyde was treated with hydrazine and 3,5-dichloroaniline to synthesize their Schiff bases, ASB1 and ASB2, which were assessed for various bioactivities. ASB1 was synthesized by conventional reflux method while ASB2 was synthesized by reflux as well as by mechanochemical grinding method which gave higher yield. The bases were recrystalised, and their structures were elucidated based on XRD and spectroscopic studies. Hirshfeld surface analysis was also carried out. They showed considerable urease inhibitory activity, almost comparable with the standard thiourea. The activity of ASB1 was much higher than ASB2. Acetylcholinesterase inhibitory activity of ASB1 was also higher than that of ASB2. The antioxidant activities were determined using DPPH, ABTS radical scavenging and total antioxidant capacity (TAC) assays. The bases were very poor scavengers of DPPH radical. However, they showed considerable anti-radical activity against ABTS radical, ASB2 being more active than ASB1, while ASB1 showed higher TAC than ASB2. In conclusion, the bases appeared to have good drugability as inhibitors of urease and acetylcholinesterase enzymes. They can be easily synthesized for possible large-scale applications. The grinding method proved to be more efficient than the reflux method.

Abstract P4-04-06: Study of the mutational landscape of normal and pregnant breast to predict pregnancy-associated breast cancer risk

Background: Amongst the various risk factors for breast cancer (BC), the molecular basis which may explain the correlation between age at first full-term and breast cancer risks is still understudied. Epidemiology studies indicate that an early first full-term pregnancy (before 25 years of age) confers a significant level of protection towards the development of post-menopausal BC compared to the risk in nulliparous or late-parous women. On the other hand, any pregnancy relates to a higher risk in developing cancer during or within one year of pregnancy (pregnancy-associated breast cancer, PABC). Thus, the relation between age of pregnancy and breast cancer risk may be too difficult to explain using only epidemiology data.

Aims of the study: With our research study, we aim to study a cohort of 60 normal breast samples of nulliparous and age-matched early- and late-parous women collected from Komen Tissue Bank, University of Indiana, and to create for the first time a mathematical model of cell clone expansion in the normal breast growth. This will allow us to determine how the rates of both cancer drivers, passenger mutations and genetic variations are affected by pregnancy. We then aim to translate this in cancer tissues, and to determine how the rate of the same mutations in both pregnancy and non pregnancy-associated cancers (post-menopausal). At the same time, we intend to create a mouse model which will be used to further validate our model, where driver mutations will be induced in the mammary epithelium of pregnant mice of different ages. This will allow us to test our model of growth of a mutated clone in a pregnancy environment, and to determine what are the molecular changes in the pregnant mammary gland which can trigger a different BC risk in the early-parous cohort.

Results: To examine the mutational landscape in the normal parous and nulliparous women, we extracted DNA from laser-capture microdissected epithelium and the stroma, the latter of which will be used to eliminate germ line mutations. We are currently analysing the results from Whole Genome Sequencing at 30x 100pe on a MGISEQ2000 platform on a first set of samples (two nulliparous samples and two age-matched parous samples from both early and late pregnancy). Our procedure for processing and analysis of this data follows the Broad Institute's “GATK Best Practice Guidelines” for use of next generation sequencing (NGS) data. Based on the collected data, we plan to continue with targeted sequencing or whole genome sequencing on the remaining samples.

Conclusions: Our study will provide novel information on which areas of the genome are mostly mutated or altered in the normal breast, and will indicate how mutated cells, including mutations in driver genes for breast cancer, and genetic alterations change in the contest of pregnancy. With the mathematical model of clone growth/extinction, we intend to explain how different ages of pregnancy can significantly alter the clone composition in the normal breast and result in a different probability of developing breast cancer.

Citation Format: Cereser B, Tabassum N, Carter P, Del Bel Belluz L, Stebbing J. Study of the mutational landscape of normal and pregnant breast to predict pregnancy-associated breast cancer risk [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-04-06.

Stem cell niche: Dynamic neighbor of stem cells

Stem cell niche is a specialized and dynamic microenvironment around the stem cells which plays a critical role in maintaining the stemness properties of stem cells. Over the years, advancement in the research activity has revealed the various important aspects of stem cell niche including cell-cell interaction, cell-extracellular matrix interaction, a large number of soluble signaling factors and various biochemical and biophysical cues (such as oxygen tension, flow, and shear and pore size). Stem cells have the potential to be a powerful tool in regenerative medicine due to their self-renewal property and immense differentiation potential. Recent progresses in in vitro culture conditions of embryonic stem cells, adult stem cells and induced pluripotent stem cells have enabled the researchers to investigate and understand the role of the microenvironment in stem cell properties. The engineered artificial stem cell niche has led to a better execution of stem cells in regenerative medicine. Here we elucidate the key components of stem cell niche and their role in niche engineering and stem cell therapeutics.

Design, synthesis, in-vitro thymidine phosphorylase inhibition, in-vivo antiangiogenic and in-silico studies of C-6 substituted dihydropyrimidines

Thymidine phosphorylase (TP) is an angiogenic enzyme. It plays an important role in angiogenesis, tumour growth, invasion and metastasis. In current research work, we study the effect of structural modification of dihydropyrimidine-2-ones (DHPM-2-ones) on TP inhibition. A series of eighteen new derivatives of 3,4-dihydropyrimidone-2-one were designed and synthesized through the structural modification at C-6 position. All these new derivatives were then assessed for in-vitro inhibition of thymidine phosphorylase (TP) from E. coli. Oxadiazole derivatives 4a-e exhibited excellent TP-inhibition at low micromolar concentration levels better than standard drug 7-deazaxanthine (7-DX). Among all these compounds, 4b was found to be the most potent with IC₅₀ = 1.09 ± 0.004 μM. Anti-angiogenesis potential of representative compounds were also studied in a chorioallantoic membrane (CAM) assay. Here again, compound 4b was found to be the potent anti-angiogenesis compound in a CAM assay. Docking studies were also performed with Molecular Operating Environment (MOE) to further analyse the mode of inhibition of these compounds. Binding mode analysis of the most active inhibitors showed that these are well accommodated into the binding site of enzyme though stable hydrogen bonding and hydrophobic interactions.

Pulmonary Arterio-Venous Malformation (PAVM): A Rare Case Report

A 6-year-old boy from Comilla, was admitted in Dhaka Medical College Hospital with exertional dyspnea, central cyanosis, clubbing and was finally diagnosed as pulmonary Arterio-Venous Malformation (PAVM) by bubble contrast echocardiography, and pulmonary CT angiography. As PAVM is rare in children, it is often not thought of in differential diagnoses and the diagnosis remains in disguise. In this report, we described the clinical presentation of 6-year-old child with PAVM and also how to investigate the case to get the diagnosis.

Determination of anti-microbial susceptibilities of Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis

OBJECTIVE

A retrospective study to determine the antibiotic resistance pattern seen in respiratory tract pathogens.

MATERIALS AND METHODS

All sputum samples received during one year period (2000) were cultured by standard laboratory technique and antibiotic sensitivity was performed by Kirby Bauer disc method.

RESULT

A total of 238 respiratory pathogens were isolated. All three isolates (Haemophilus influenzae, Streptococcus pnuemoniae and Moraxella catarrhalis) were highly resistant against Trimethoprim Sulfamethoxazole. Strep. pnuemoniae was not resistant to Penicillin. Rest of the antibiotics showed good response.

CONCLUSION

Strep. pnuemoniae is still very sensitive to Penicillin and all three pathogens were resistant to Timethoprim Sulfamethoxazale.

Properties of the radicals formed by one-electron oxidation of acetaminophen--a pulse radiolysis study

The semi-iminoquinone radical of acetaminophen, which has previously been proposed as a possible hepatotoxic intermediate in the cytochrome P-450 catalysed oxidation of acetaminophen, has been generated and studied by pulse radiolysis. In the absence of other reactive solutes, the radical decays rapidly by second order kinetics with a rate constant (2k2) of (2.2 +/- 0.4) x 10(9) M-1 sec-1. In alkaline solutions the radical deprotonates with a pK of 11.1 +/- 0.1 to form a radical-anion, as confirmed by the effect of ionic strength on the rate of radical decay. The acetaminophen radical-anion reacts with resorcinol at high pH values, leading to the formation of a transient equilibrium from which the one-electron reduction potential of the semi-iminoquinone radical of acetaminophen is estimated to be +0.707 +/- 0.01 V at pH 7. This value predicts that acetaminophen should be oxidised by thiyl radicals. This was confirmed by pulse radiolysis experiments for reaction of the cysteinyl radical, for which rate constants of 7 x 10(6) M-1 sec-1 at pH 7 and 2.7 x 10(8) M-1 sec-1 at pH 11.3 were obtained. The reaction of O2 with the acetaminophen semi-iminoquinone radical could not be detected by pulse radiolysis, and alternative mechanisms for superoxide radical formation are discussed.