Toothbrushes as a Source of DNA for Gender and Human Identification-A Systematic Review

Comparison of gender identification using exfoliated cells obtained from toothbrush and miswak: A longitudinal study

Gender identification plays a pivotal role in forensic medicine. Among the various methods used for gender identification, deoxyribose nucleic acid (DNA) based methods are considered accurate. Exfoliated oral mucosal cells that are harvested from oral hygiene aids can be potentially used for gender identification using real-time polymerase chain rection (PCR). The aim of the present longitudinal study is to assess and compare the efficacy of toothbrush and miswak as potential tools to harvest exfoliated cells for gender identification. Forty healthy volunteers were recruited and asked to clean their teeth using new toothbrush and fresh miswak each day for 4 days. Toothbrush and miswak used by the participants were subjected to DNA analysis immediately, 1st, 2nd and 6th month. The absorbance of DNA samples were quantified and gender identification was done by amplification of sex determining gene-Sex determining region Y gene (SRY) and ALT1 genes using real-time PCR. The number of correct and positive identification for samples at various time points were tabulated and subjected to statistical analysis. Post hoc power analysis showed that the study had a power of 93%. Correct and positive gender identification was observed for the samples (100%) obtained using miswak, for tooth brush it reduced to 95%, 80%, and 35% at the end of 1st, 2nd, and 6th month. The differences seen at the end of 2nd month and 6th month were statistically significant. Miswak is a better tool to harvest exfoliated cells for gender identification when compared to a toothbrush. Hence, miswak can serve as a potential tool in forensic medicine for DNA extraction and subsequently victim identification.

A systematic review of patient-reported dignity and dignified care during acute hospital admission

AIMS

To synthesize quantitative evidence on levels of dignity during acute hospital admission and identify barriers and facilitators to patients' dignity or dignified care from the perspective of hospitalized patients. The secondary aim was to examine the relationship between dignity and demographic, clinical and psychological characteristics of patients.

DESIGN

A systematic review based on the protocol of the Preferred Reporting Items for Systematic reviews and Meta-Analyses guideline for reporting systematic reviews.

DATA SOURCES

Five electronic databases (PubMed, CINAHL, Embase, PsycINFO, AgeLine) were searched in February 2021, followed by backward-forward searching using Web of Science and Scopus databases.

REVIEW METHODS

Potentially eligible articles were scrutinized by two reviewers. Articles that met the eligibility criteria were appraised for quality using the Critical Appraisal Tool for Cross-Sectional Studies. Two reviewers extracted data for the review and resolved differences by consensus.

RESULTS

Out of 3052 potentially eligible studies, 25 met the inclusion criteria. Levels of dignity for hospitalized patients vary widely across geographic locations. Patients' dignity is upheld when healthcare professionals communicate effectively, maintain their privacy, and provide dignity therapy. Patients' perceptions of dignity were, in some studies, reported to be associated with demographic (e.g. age, marital status, gender, employment, educational status), clinical (e.g. hospitalization, functional impairment, physical symptoms) and psychological (e.g. depression, anxiety, demoralization, coping mechanisms) variables whilst other studies did not observe such associations.

CONCLUSION

Patients in acute care settings experience mild to a severe loss of dignity across different geographic locations. Patients' dignity is influenced by several demographic, clinical and psychological characteristics of patients.

IMPACT

The findings of the review support impetus for improvement in dignified care for hospitalized patients, addressing factors that facilitate or impede patients' dignity. Measures aimed at alleviating suffering, fostering functional independence and addressing patients' psychosocial needs can be used to promote dignity.

Role of Toothbrushes as Gene Expression Profiling Tool for Oral Cancer Screening in Tobacco and Alcohol Users

AIM

The use of toothbrushes was investigated as a potential RNA source and gene expression profiling tool for oral cancer screening in tobacco and alcohol users.

METHODOLOGY

A total of 20 subjects were selected on the basis of inclusion and exclusion criteria. They were divided into two groups: group I-healthy controls (n = 6); group II-individuals who consume tobacco and alcohol (n = 14). After the volunteers brushed their teeth using a soft-bristle toothbrush with ~0.5 gm of toothpaste, the toothbrushes were collected, and the gene expression of BAX, BCL2, CDK4, CKDN2A, GNB3, and TCF7L2 was assessed.

RESULTS

The gene expression of BAX decreased significantly in alcoholics and smokers (0.13867 ± 0.12014), while the gene expression of BCL2 increased in alcoholics and smokers (1.91001 ± 0.90425) in comparison with healthy controls (p = 0.0054 and p = 0.0055). Although there was increased expression of CDK4, CKDN2A, and TCF7L2 and decreased expression of GNB3 in smokers and alcoholics, the results were not significant.

CONCLUSIONS

A toothbrush is a good source of RNA, and gene expression analysis can be performed using the genetic material retrieved from toothbrushes, which can aid in the early diagnosis of oral squamous cell carcinoma among tobacco and alcohol users. Further studies with a larger sample size and different durations of toothbrush use should be conducted to explore the role of toothbrushes as a noninvasive tool for disease diagnosis.