The effect of different tobacco tar levels on DNA damage in cigarette smoking subjects

The Smoky Impact of Nicotinic Acetylcholine Receptors on Testicular Function

Smoking habits (from classic cigarettes to e-cigarettes and heated tobacco) are a relatively common finding in the medical histories of couples referred to fertility centers. Tobacco smoke and e-cigarettes may deliver many substances with known harmful effects on both general and reproductive health, including nicotine. Nicotinic Acetylcholine receptors (nAChRs) form a heterogeneous family of ion channels that are differently expressed in different tissues. According to the homomeric or heteromeric combination of at least five different subunits (named from α to ε), they have peculiar pharmacological and biophysical properties. nAChRs respond to the neurotransmitter acetylcholine, which influences a number of physiological functions not restricted to neurons and plays an important role in the structure and function of non-neuronal tissues such as the testis. nAChRs are also the target of Nicotine, the active element responsible for tobacco addiction. This review summarizes recent findings on the involvement of nAChRs in testicular physiology, highlighting the effects of nicotine exposure observed in animal studies and clinical settings. We will discuss the latest data on fertility outcomes and the implications for understanding nAChR functions in reproductive health.

Evaluating the Effects of Cigarette Smoking and Heated Tobacco Products on Hard Dental Tissues: A Comparative Histological and Colorimetric Analysis

OBJECTIVES

This study aimed to evaluate and compare the impact of cigarette smoking (CS) and heated tobacco (HT) on the alteration of color and ultrastructural characteristics of human enamel and cementum.

BACKGROUND

According to tobacco companies, a less harmful substitute for CS is HT products. Nevertheless, comprehensive research on the effects of HT on tooth structures has been lacking. This study aimed to evaluate and compare the impact of CS and HT on the alteration of color and ultrastructural characteristics of human enamel and cementum.

MATERIALS AND METHODS

Thirty intact and noncarious human maxillary premolars extracted for orthodontic treatment purposes, previously disinfected, were used in the study. The specimens were randomly separated into six groups (n = 10), as follows: Group 1: enamel without smoking exposure; Group 2: enamel exposed to CS; Group 3: enamel exposed to HT; Group 4: cementum without smoking exposure; Group 5: cementum exposed to CS; and Group 6: cementum exposed to HT. The measurement of color change was conducted using a spectrophotometer. The surface alterations and mineral composition of enamel and cementum were evaluated using scanning electron microscopy and energy-dispersive X-ray spectroscopy. ANOVA test followed by Tukey's post hoc test was used to determine significant differences between groups.

RESULTS

Results showed that CS had a more pronounced effect on enamel and cementum color changes than HT. The impact of CS and HT on color changes was more evident in cementum than in enamel. Surface morphology of enamel and cementum showed alterations in histology following exposure to both smoking types. Moreover, the mineral content experienced a significant reduction after using CS and HT. The reduction in calcium content after CS and HT exposure was similar. However, HT led to a significant decrease in the phosphorus content of enamel when compared with CS. At the same time, CS exposure in cementum resulted in a more significant reduction in Ca/P ratio than HT.

CONCLUSIONS

Although HT may appear to present a lower danger to hard dental tissues than CS, it is not entirely harmless. CS results in more color changes on the enamel and cementum of teeth. Both smoking methods affected the mineral content of teeth, with CS having a significant effect on the roots, while HT significantly affected the crowns' mineral composition.

Tracking the Variations in Trace and Heavy Elements in Smoking Products Marketed in Oman and Egypt: Risk Assessment After Implementation of Constraining Protocols

Tobacco smoking is becoming one of the major worldwide concerns regarding environmental pollution as well as health threats. In 2005, the World Health Organization (WHO) released the Framework Convention On Tobacco Control (FCTC), which outlined protocols for controlling tobacco products. Oman was one of the leading countries to follow these protocols; however, Egypt has only followed these protocols recently in 2020. One of the main challenges in tobacco product control is the variation in their trace element's types and amounts from country to country owing to differences in agriculture techniques and used chemical additives. Smoking releases different toxic metal ions found in them into the air, and hence, analyzing trace amounts of metals in tobacco smoking products is becoming more critical. The proposed research aims to evaluate the current levels of 11 heavy metals (namely, As, Pb, Cd, Co, Cr, Be, Ba, Mn, Ni, Fe, and Hg) in 22 tobacco products available in Egypt and Oman using inductively coupled plasma optical emission spectroscopy and a direct mercury analyzer. Although some elements such as Be, Co, and Cd were absent, the positive detection of As and Pb and the levels of Ba, Cr, and Ni are still alarming, especially for heavy smokers. The obtained results were then statistically related to previously published data in 2017 to explore the effectiveness of implementing the FCTC protocols within the Egyptian market. The outcomes suggested a positive impact of FCTC protocol implementation in Egypt, besides the lower levels of elemental content for Omani products compared to the Egyptian market.

Comet assay as a suitable biomarker for in vivo oral carcinogenesis: a systematic review

BACKGROUND AND OBJECTIVES

In order to detect genetic damage, different methods have been developed, such as micronuclei and comet assay. The comet assay presents some advantages when compared to the other aforementioned methods, including wide versatility, as any eukaryotic cell can be evaluated at an individual cellular level. In this context, the aim of this systematic review was designed to help further elucidate the following question: is the comet assay a suitable biomarker of in vivo oral carcinogenesis?

MATERIAL AND METHODS

The present systematic review was performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Full manuscripts from 18 studies were carefully selected in this setting.

RESULTS

A total of 15 studies demonstrated positive findings for genotoxicity in peripheral blood or oral cells in patients with pre-malignant lesions or oral cancer. In the quality assessment of studies, 1 was classified as Strong, 5 were considered as Moderate, and 12 were classified as Weak.

CONCLUSION

In summary, the comet assay can be a useful biomarker for oral carcinogenesis. However, further studies with more strict parameters are suggested (with less uncontrolled confounders) in order to increase findings reliability for diagnosis of oral potentially malignant lesions.