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International Journal of Environmental... Apr 2021The tobacco industry promotes electronic nicotine delivery systems (ENDS) and heated tobacco products (HTP) as a safer alternative to conventional cigarettes with... (Review)
Review
The tobacco industry promotes electronic nicotine delivery systems (ENDS) and heated tobacco products (HTP) as a safer alternative to conventional cigarettes with misleading marketing sustained by studies with conflict of interest. As a result, these devices sell without regulations and warnings about their adverse effects on health, with a growing user base targeting young people. This systematic review aimed to describe the adverse effects on the respiratory system in consumers of these devices. We conducted a systematic review and bibliometric analysis of 79 studies without conflict of interest evaluating ENDS and HTP effects in the respiratory system in experimental models, retrieved from the PubMed database. We found that the damage produced by using these devices is involved in pathways related to pulmonary diseases, involving mechanisms previously reported in conventional cigarettes as well as new mechanisms particular to these devices, which challenges that the tobacco industry's claims. The present study provides significant evidence to suggest that these devices are an emerging public health problem and that they should be regulated or avoided.
Topics: Adolescent; Electronic Nicotine Delivery Systems; Humans; Lung; Marketing; Tobacco Industry; Tobacco Products
PubMed: 33924379
DOI: 10.3390/ijerph18084079 -
The Journal of Clinical and Aesthetic... Jun 2023Phototherapy has gained popularity in the recent decades for the treatment of various immune-mediated dermatological conditions since it is more-cost effective and less...
Phototherapy has gained popularity in the recent decades for the treatment of various immune-mediated dermatological conditions since it is more-cost effective and less toxic compared to systemic therapies. This systematic review aims to inform dermatology providers of the risks and benefits of phototherapy, especially in patients at risk for malignancies. Ionizing energy from phototherapy results in DNA photolesions, namely of cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs). Without adequate repair, these mutations increase the risk for carcinogenesis. Additionally, phototherapy can also indirectly cause DNA damage through the formation of reactive oxygen species (ROS), which damage of several structural and functional proteins and DNA. When choosing a phototherapy modality, it also important to take into consideration the side effect profiles associated with each modality. For instance, a 10-fold higher dose of NB-UVB is required to produce a similar amount of CPDs compared with BB-UVB. Patients who undergo UVA with psoralen (PUVA) can be susceptible to developing skin malignancies up to 25 years after receiving their last treatment. It would behoove providers to consider optimal radiation dosage given each patients' level of skin pigmentation and potential for photoadaptation. Additionally, there are measures have been proposed to minimize deleterious skin changes, such as a 42-degree Celsius heat treatment using a 308nm excimer laser prior to UVB phototherapy and low frequency, low intensity electromagnetic fields along with UVB. However, as performing routine skin exams, remain paramount in the prevention of phototherapy-induced neoplasia.
PubMed: 37361361
DOI: No ID Found -
Critical Reviews in Toxicology Nov 2022Existing literature suggests an association between chronic cadmium (Cd) exposure and the induction of DNA damage and genotoxicity. However, observations from individual... (Meta-Analysis)
Meta-Analysis Review
Existing literature suggests an association between chronic cadmium (Cd) exposure and the induction of DNA damage and genotoxicity. However, observations from individual studies are inconsistent and conflicting. Therefore current systematic review aimed to pool evidence from existing literature to synthesize quantitative and qualitative corroboration on the association between markers of genotoxicity and occupational Cd exposed population. Studies that evaluated markers of DNA damage among occupationally Cd-exposed and unexposed workers were selected after a systematic literature search. The DNA damage markers included were chromosomal aberrations (chromosomal, chromatid, sister chromatid exchange), Micronucleus (MN) frequency in mono and binucleated cells (MN with condensed chromatin, lobed nucleus, nuclear buds, mitotic index, nucleoplasmatic bridges, pyknosis, and karyorrhexis), comet assay (tail intensity, tail length, tail moment, and olive tail moment), and oxidative DNA damage (8-hydroxy-deoxyguanosine). Mean differences or standardized mean differences were pooled using a random-effects model. The Cochran- test and statistic were used to monitor heterogeneity among included studies. Twenty-nine studies with 3080 occupationally Cd-exposed and 1807 unexposed workers were included in the review. Cd among the exposed group was higher in blood [4.77 μg/L (-4.94-14.48)] and urine samples [standardized mean difference 0.47 (0.10-0.85)] than in the exposed group. The Cd exposure is positively associated with higher levels of DNA damage characterized by increased frequency of MN [7.35 (-0.32-15.02)], sister chromatid exchange [20.30 (4.34-36.26)], chromosomal aberrations, and oxidative DNA damage (comet assay and 8OHdG [0.41 (0.20-0.63)]) compared to the unexposed. However, with considerable between-study heterogeneity. Chronic Cd exposure is associated with augmented DNA damage. However, more extensive longitudinal studies with adequate sample sizes are necessary to assist the current observations and promote comprehension of the Cd's role in inducing DNA damage. CRD42022348874.
Topics: Humans; Cadmium; Micronucleus Tests; Occupational Exposure; DNA Damage; Chromosome Aberrations
PubMed: 36802997
DOI: 10.1080/10408444.2023.2173557 -
Reproductive Biology and Endocrinology... Jan 2023Infertility affects one in every six couples in developed countries, and approximately 50% is of male origin. In 2021, sperm DNA fragmentation (SDF) testing became an... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Infertility affects one in every six couples in developed countries, and approximately 50% is of male origin. In 2021, sperm DNA fragmentation (SDF) testing became an evidence-based test for fertility evaluations depicting fertility more clearly than standard semen parameters. Therefore, we aimed to summarize the potential prognostic factors of a higher SDF.
METHODS
We conducted a systematic search in three medical databases and included studies investigating any risk factors for SDF values. We calculated mean differences (MD) in SDF with 95% confidence interval (CI) for exposed and non-exposed individuals.
RESULTS
We included 190 studies in our analysis. In the group of associated health conditions, varicocele (MD = 13.62%, CI: 9.39-17.84) and impaired glucose tolerance (MD = 13.75%, CI: 6.99-20.51) had the most significant increase in SDF. Among malignancies, testicular tumors had the highest impact, with a maximum of MD = 11.3% (CI: 7.84-14.76). Among infections, the overall effects of both Chlamydia and HPV were negligible. Of lifestyle factors, smoking had the most disruptive effect on SDF - an increase of 9.19% (CI: 4.33-14.06). Different periods of sexual abstinence did not show significant variations in SDF values. Age seemed to have a more drastic effect on SDF from age 50 onwards, with a mean difference of 12.58% (CI: 7.31-17.86). Pollution also had a detrimental effect - 9.68% (CI: 6.85-12.52).
CONCLUSION
Of the above risk factors, varicocele, impaired glucose tolerance, testicular tumors, smoking, pollution, and paternal age of over 50 were associated with the highest SDF.
TRIAL REGISTRATION
CRD42021282533.
Topics: Humans; Male; Middle Aged; Semen; DNA Fragmentation; Varicocele; Glucose Intolerance; Spermatozoa; Life Style; Testicular Neoplasms; Infertility, Male
PubMed: 36653793
DOI: 10.1186/s12958-023-01054-0 -
Reviews on Environmental Health Mar 2023Inappropriate processing and disposal of electronic waste (e-waste) expose workers and surrounding populations to hazardous chemicals, including clastogens and aneugens.... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Inappropriate processing and disposal of electronic waste (e-waste) expose workers and surrounding populations to hazardous chemicals, including clastogens and aneugens. Recently, considerable literature has grown around e-waste recycling, associated chemical exposures and intermediate health outcomes, including DNA damage. Micronuclei (MN) frequency has been widely used as a biomarker to investigate DNA damage in human populations exposed to genotoxic agents. We conducted a systematic review of published studies to assess DNA damage in e-waste-exposed populations and performed a meta-analysis to evaluate the association between e-waste exposure and DNA damage.
METHODS
This systematic review with meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement checklist. Articles published in English from January 2000 through December 2020 investigating the associations between e-waste exposure and DNA damage were retrieved from the following three major databases: MEDLINE, ProQuest, and Scopus. Studies that reported the use of MN assay as a biomarker of DNA damage were included for meta-analysis. Studies that also reported other DNA damage biomarkers such as chromosomal aberrations, comet assay biomarkers, 8-hydroxy-2'-deoxyguanosine (8-OHdG), telomere length, apoptosis rate were reported using narrative synthesis.
RESULTS
A total of 20 publications were included in this review, of which seven studies were within the occupational setting, and the remaining 13 studies were ecological studies. The review found six biomarkers of DNA damage (micronuclei, comets assay parameters (tail length, % tail DNA, tail moment, and olive tail moment), 8-OHdG, telomere length, apoptosis rate and chromosomal aberrations) which were assessed using seven different biological matrices (buccal cells, blood, umbilical cord blood, placenta, urine and semen). Most studies showed elevated levels of DNA damage biomarkers among e-waste exposed populations than in control populations. The most commonly used biomarkers were micronuclei frequency (n=9) in peripheral blood lymphocytes or buccal cells and 8-OHdG (n=7) in urine. The results of the meta-analysis showed that electronic waste recycling has contributed to an increased risk of DNA damage measured using MN frequency with a pooled estimate of the standardized mean difference (SMD) of 2.30 (95% CI: 1.36, 3.24, p<0.001) based on 865 participants.
CONCLUSIONS
Taken together, evidence from this systematic review with meta-analysis suggest that occupational and non-occupational exposure to e-waste processing is associated with increased risk of DNA damage measured through MN assay and other types of DNA damage biomarkers. However, more studies from other developing countries in Africa, Latin America, and South Asia are needed to confirm and increase these results' generalizability.
Topics: Humans; Electronic Waste; Mouth Mucosa; DNA Damage; Chromosome Aberrations; Biomarkers
PubMed: 34727591
DOI: 10.1515/reveh-2021-0074 -
Advances in Experimental Medicine and... 2019DNA fragmentation, or the accumulation of single- and double-strand DNA breaks, is a common property of sperm, and an increase in the level of sperm DNA fragmentation is...
DNA fragmentation, or the accumulation of single- and double-strand DNA breaks, is a common property of sperm, and an increase in the level of sperm DNA fragmentation is known to influence natural reproduction. The effect of sperm DNA fragmentation on male infertility and assisted reproductive treatment (ART) outcomes remains controversial and is one of the most frequently debated topics of reproductive medicine. For the past 30 years, a number of assays have been developed to quantify the level of sperm DNA fragmentation. In this chapter, we review the causes of sperm DNA fragmentation, describe the commonly used tests to evaluate these abnormalities, and perform a systematic review of existing studies to determine the impact of sperm DNA fragmentation on male fertility and ART outcomes.
Topics: DNA Fragmentation; Female; Humans; Infertility, Male; Male; Reproduction; Reproductive Techniques, Assisted; Spermatozoa; Treatment Outcome
PubMed: 31301048
DOI: 10.1007/978-3-030-21664-1_6 -
Sports Medicine (Auckland, N.Z.) Jan 2020Exercise is widely recognised for its health enhancing benefits. Despite this, an overproduction of reactive oxygen and nitrogen species (RONS), outstripping antioxidant... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Exercise is widely recognised for its health enhancing benefits. Despite this, an overproduction of reactive oxygen and nitrogen species (RONS), outstripping antioxidant defence mechanisms, can lead to a state of (chronic) oxidative stress. DNA is a vulnerable target of RONS attack and, if left unrepaired, DNA damage may cause genetic instability.
OBJECTIVE
This meta-analysis aimed to systematically investigate and assess the overall effect of studies reporting DNA damage following acute aerobic exercise.
METHODS
Web of Science, PubMed, MEDLINE, EMBASE, and Scopus were searched until April 2019. Outcomes included (1) multiple time-points (TPs) of measuring DNA damage post-exercise, (2) two different quantification methods (comet assay and 8-oxo-2'-deoxyguanosine; 8-OHdG), and (3) protocols of high intensity (≥ 75% of maximum rate of oxygen consumption; VO) and long distance (≥ 42 km).
RESULTS
Literature search identified 4316 non-duplicate records of which 35 studies were included in the meta-analysis. The evidence was strong, showcasing an increase in DNA damage immediately following acute aerobic exercise with a large-effect size at TP 0 (0 h) (SMD = 0.875; 95% CI 0.5, 1.25; p < 0.05). When comparing between comet assay and 8-OHdG at TP 0, a significant difference was observed only when using the comet assay. Finally, when isolating protocols of long-distance and high-intensity exercise, increased DNA damage was only observed in the latter. (SMD = 0.48; 95% CI - 0.16, 1.03; p = 0.15 and SMD = 1.18; 95% CI 0.71, 1.65; p < 0.05 respectively).
CONCLUSIONS
A substantial increase in DNA damage occurs immediately following acute aerobic exercise. This increase remains significant between 2 h and 1 day, but not within 5-28 days post-exercise. Such an increase was not observed in protocols of a long-distance. The relationship between exercise and DNA damage may be explained through the hormesis theory, which is somewhat one-dimensional, and thus limited. The hormesis theory describes how exercise modulates any advantageous or harmful effects mediated through RONS, by increasing DNA oxidation between the two end-points of the curve: physical inactivity and overtraining. We propose a more intricate approach to explain this relationship: a multi-dimensional model, to develop a better understanding of the complexity of the relationship between DNA integrity and exercise.
Topics: DNA Damage; Exercise; Humans
PubMed: 31529301
DOI: 10.1007/s40279-019-01181-y -
Archives of Toxicology Nov 2022Studies suggest that chronic lead (Pb) exposure may induce deoxyribonucleic acid (DNA) damage. However, there is no synthesised evidence in this regard. We... (Meta-Analysis)
Meta-Analysis Review
Studies suggest that chronic lead (Pb) exposure may induce deoxyribonucleic acid (DNA) damage. However, there is no synthesised evidence in this regard. We systematically reviewed existing literature and synthesised evidence on the association between chronic Pb exposure and markers of genotoxicity. Observational studies reporting biomarkers of DNA damage among occupationally Pb-exposed and unexposed controls were systematically searched from PubMed, Scopus and Embase databases from inception to January 2022. The markers included were micronucleus frequency (MN), chromosomal aberrations, comet assay, and 8-hydroxy-deoxyguanosine. During the execution of this review, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Mean differences in the biological markers of DNA damage between Pb-exposed and control groups were pooled using the random-effects model. The heterogeneity was assessed using the Cochran-Q test and I statistic. The review included forty-five studies comparing markers of DNA damage between Pb-exposed and unexposed. The primary studies utilised buccal and/or peripheral leukocytes for evaluating the DNA damage. The pooled quantitative results revealed significantly higher DNA damage characterised by increased levels of MN and SCE frequency, chromosomal aberrations, and oxidative DNA damage (comet assay and 8-OHdG) among Pb-exposed than the unexposed. However, studies included in the review exhibited high levels of heterogeneity among the studies. Chronic Pb exposure is associated with DNA damage. However, high-quality, multicentred studies are required to strengthen present observations and further understand the Pb's role in inducing DNA damage. CRD42022286810.
Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers; Chromosome Aberrations; Comet Assay; DNA; DNA Damage; Humans; Lead; Micronucleus Tests; Occupational Exposure
PubMed: 35930012
DOI: 10.1007/s00204-022-03352-9 -
Andrologia Feb 2022The updated meta-analysis was conducted to further verify the effect of varicocele on sperm DNA damage, supplying clinicians and researchers with high-grade evidence.... (Meta-Analysis)
Meta-Analysis Review
The updated meta-analysis was conducted to further verify the effect of varicocele on sperm DNA damage, supplying clinicians and researchers with high-grade evidence. The sperm DNA damage was evaluated by DNA fragmentation index (DFI), associated with the male fertility capability tightly. PubMed, Web of Science and Cochrane Library were searched extensively for eligible studies with the search terms: varicocele, sperm DNA and sperm DNA damage. Finally, a total of 12 studies were included in our meta-analysis with a total of 845 patients diagnosed with varicocele and 2,377 healthy controls. A statistical difference of DFI between varicocele patients and healthy controls was found after pooling the data ((Standardised mean difference) SMD: 1.40, 95%CI: 0.83-1.98, p < .0001), using the random effect model. We conducted subgroup analysis according to study region (Brazil and Other countries), detection methods of DFI (TUNEL, Comet, and SCSA), sample size (<50 and >50) and age (<30 and >30 years), based on substantial heterogeneity among eligible studies. The stability of pooled results was verified by sensitivity analysis. All these statistical analyses were conducted using Stata version 16.0. In conclusion, patients diagnosed with clinical varicocele had higher DFI than healthy controls, which means varicocele could impair sperm DNA, consequently the fertility potential of affected men.
Topics: Adult; DNA Damage; DNA Fragmentation; Humans; Infertility, Male; Male; Spermatozoa; Varicocele
PubMed: 34658054
DOI: 10.1111/and.14275 -
Andrology Jul 2017Beside cytotoxic drugs, other drugs can impact men's fertility through various mechanisms. Via the modification of the hypothalamic-pituitary-gonadal axis hormones or by... (Review)
Review
Beside cytotoxic drugs, other drugs can impact men's fertility through various mechanisms. Via the modification of the hypothalamic-pituitary-gonadal axis hormones or by non-hormonal mechanisms, drugs may directly and indirectly induce sexual dysfunction and spermatogenesis impairment and alteration of epididymal maturation. This systematic literature review summarizes existing data about the negative impact and associations of pharmacological treatments on male fertility (excluding cytotoxic drugs), with a view to making these data more readily available for medical staff. In most cases, these effects on spermatogenesis/sperm maturation/sexual function are reversible after the discontinuation of the drug. When a reprotoxic treatment cannot be stopped and/or when the impact on semen parameters/sperm DNA is potentially irreversible (Sulfasalazine Azathioprine, Mycophenolate mofetil and Methotrexate), the cryopreservation of spermatozoa before treatment must be proposed. Deleterious impacts on fertility of drugs with very good or good level of evidence (Testosterone, Sulfasalazine, Anabolic steroids, Cyproterone acetate, Opioids, Tramadol, GhRH analogues and Sartan) are developed.
Topics: Animals; Cryopreservation; DNA Damage; Drug-Related Side Effects and Adverse Reactions; Fertility; Fertility Preservation; Humans; Infertility, Male; Male; Risk Assessment; Risk Factors; Sexual Behavior; Sperm Banks; Spermatogenesis; Spermatozoa
PubMed: 28622464
DOI: 10.1111/andr.12366