Quantitative Analysis of Skin Erythema Due to Laser Hair Removal: A Diffusion Optical Spectroscopy Analysis

 Introduction: Laser hair removal needs an accurate understanding of tissue structure and chromophores content in order to optimize the selection of laser irradiation parameters. None of the optimized laser therapy might lead to side effects in skin tissue such as severe erythema, burn, scar etc. Therefore, guidance by a noninvasive real-time diagnostic method like optical spectroscopy technique is beneficial. The purpose of this survey is to analysis the skin hemoglobin spectrum quantitatively before and after hair removal laser irradiation to minimize the side effects of the procedure.Methods: To carry out a spectroscopy study, a halogen-tungsten light source was used in the wavelength region of 400-700 nm on an ocean optic device. The measurements were made on the facial area under identical conditions. Total 19 volunteers for laser hair removal by gentle laser Candela, ranging 14- 49 years old, were included in the study. A total of 18 spectra were taken from each person, 9 spectra before hair removal as a reference and 9 subsequent spectra. Colorimetry was done for all acquired before and after spectrums using Origin software (version 8.6). Then, the erythema index derived for each spectrum. Statistical analysis of correlation and normalization in colorimetry data were done using data analysis by SPSS (version 16).Results: Spectra analysis, before and after optical reflectance spectrums in laser hair removal procedure, revealed the subpeak derivation, and concentration on special visible wavelength 510-610 nm. We studied the changes of skin chromophores absorption. The derived erythema index [E] and colorimetry parameters a*, b*, l* were compared and correlated statistically. There was a statistically considerable direct linear correlation between a* and E while inverse linear correlation was observed for l* and E and no correlation for b* and E.Conclusion: Diffuse reflectance spectroscopy showed its potency as an accurate, noninvasive real-time as complementary method for laser treatment to detect erythema as a complication of the method, in order to optimize the parameters based on the tissue characteristics in various candidates

The Immediate Pain-Relieving Effects of Non-Thermal CO2 Laser Therapy on Genital Ulcers of Behcet’s Disease: A Case Report

Behçet’s disease (BD) is a chronic, relapsing, systemic vasculitis of unknown etiology. Oral and genital aphthous ulcers are considered as the hallmarks of BD. The genital ulcers of BD may be extremely painful and often refractory to multiple treatments. In addition, they exert a negative impact on the patient’s quality of life. Some investigations have demonstrated the significant and immediate pain-relieving effects of NTCLT (non-thermal CO2 laser therapy) on some oral lesions with no visible adverse effects. In this paper, we report a case of BD whose painful genital ulcers were irradiated with NTCLT and the patient’s pain caused by the ulcers relieved immediately and significantly with no visible complications

Low Level Laser Therapy in Management of Chemotherapy-Induced Oral Mucositis: Prophylaxis or Treatment?

INTRODUCTION: Chemotherapy-induced oral mucositis (COM) is a common, debilitating complication of cancer therapy. The aims of this study were to evaluate the effect of low level laser therapy (LLLT) on prevention of COM in patients with hematologic malignancies.METHODS: Fifty-five patients hospitalized to undergo chemotherapy in Imam Hospital were included into the study. These patients were divided into two groups. The oral cavity of the patients were illuminated by continues laser beam using a GaAlAs laser device with wavelength of 630 nm, power output 30 mW, and dose of 5 J/cm2 for six days (LLLT group). The patients in the second group underwent placebo irradiation (power output equal to zero) with the similar protocol. The severity of the COM was clinically evaluated based on WHO grading scale. The patientys’quality of life was assessed before and after the intervention according to EORTC QLQ-C30 questionnaire.RESULTS: The incidence of COM in LLLT group (31%) was less than the placebo group (41%). Mean duration of COM healing was 4.8 and 12 days in LLLT and placebo groups, respectively (p=0.03). Xereostomia was significantly less severe in LLLT group in comparison with the placebo group (p=0.007).CONCLUSION: Our findings showed that LLLT significantly reduced the incidence of oral mucositis of WHO grade 3 and 4 as the most debilitating form of oral mucositis,in which oral alimentation is impossible. Also, LLLT could reduce duration of oral mucositis, decreased the risk of secondary infection, and accelerated return to normal nutrition.

Relieving Pain in Oral Lesions of Pemphigus Vulgaris Using the Non-ablative, Non-thermal, CO2 Laser Therapy (NTCLT): Preliminary Results of a Novel Approach

Introduction: Pemphigus vulgaris (PV) is a chronic, serious autoimmune mucocutaneous bullous disease. Oral lesions in PV may be extremely painful. This pain may adversely affect the patients’ oral intake and quality of life. This before-after clinical trial was designed to assess the pain relieving effects of single session of non-ablative, non-thermal CO2 laser therapy (NTCLT) in oral lesions of PV.Methods: Fifty painful oral lesions of fourteen patients with PV were illuminated by CO2 laser (power: 1 W, scanning the lesions with rapid circular motion of the handpiece) passing through a thick layer of transparent gel with high water content. The pain severity of the oral lesions was reported by the patients up to the fourth postoperative day. They were also asked to continue their existing systemic treatment during the course of this study as a precondition for the participation.Results: The severity of contact and non-stimulate (non-contact) pain declined immediately and significantly after NTCLT (P < 0.001). The pain relieving effect was sustained during the four successive days of follow-up. The procedure was pain free and no kind of analgesics was required. Following NTCLT, there were no visible thermal complications such as destruction, ablation or irritation of the oral lesions.Conclusion: The results of the trial proposed that single session of NTCLT could immediately and significantly relieve pain in oral lesions of PV, without any visible thermal complications

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Clinical effect of Non-Thermal CO2 Laser Therapy (NTCLT) on Pain Relief of Oral Aphthous Ulcers of Behçet’s Disease: Pain Relieving Effects of NTCLT on Oral BD Ulcers

Introduction: Behçet’s disease (BD) is a debilitating and chronic vasculitis that can affect multiple organs. Recurrent oral aphthosis is the most common clinical feature of BD. The remarkable pain associated with painful oral ulcers can exert a major impact on the patients’ quality of life. Non-thermal CO2 laser therapy (NTCLT) as a novel photobiomodulative approach has recently been used for significant and immediate pain reduction of some types of painful oral lesions such as recurrent aphthous stomatitis, pemphigus Vulgaris, and so on. In this procedure by some considerations, the conventional CO2 laser is used as a non-surgical, non-thermal, photobiomodulative laser without any visible thermal adverse effects. In this article, we report ourexperiences about the analgesic effects of NTCLT on painful oral aphthous ulcers of BD.Case Presentation: We report four cases of BD, whose painful oral aphthous ulcers were irradiated with NTCLT. Immediately after NTCLT, the pain of the lesions was significantly relieved with no visible complications.Conclusion: The results of this study suggest that NTCLT could be proposed as a hopeful procedure for significant and instant pain relief of oral aphthous ulcers of BD without any visible thermal adverse effects. DOI:10.34172/jlms.2021.72

Non-thermal CO2 Laser Therapy (NTCLT): A Novel Photobiomodulative Approach for Immediate Pain Relief of Patchy Oral Mucositis Due to Chemotherapy of Solid Tumors: NTCLT/ pain relief of COM

Introduction: Chemotherapy-induced oral mucositis (COM) is a prominent complication of chemotherapy (CT). Non-thermal CO2 laser therapy (NTCLT) has been demonstrated as an innovative and safe photobiomodulative approach in some kinds of painful oral lesions. The purpose of this study was to evaluate the palliative effects of one session of NTCLT on COM lesions.Methods: Patients with painful COM (WHO grade:≥2) were included in this before-after clinical trial based on the eligibility criteria. The oral lesions were irradiated with a CO2 laser (power: 1 W, scanning the lesions with the rapid circular motion of the defocused handpiece) through a thick layer (3-4 mm) of a transparent gel containing a high water content. The severity of pain in the lesions was self-assessed using a 0-to-10 visual analog scale (VAS) for 7 consecutive days. The evaluating physician visited the patients on the 3rd and 7th days in search of any kind of complications.Results: Seventeen adult patients with 35 patches of OM due to chemotherapy of solid tumors completed the trial. Immediately after NTCLT, the mean for non-contact VAS pain scores of the lesions significantly declined from 4.91±2.356 to 0.29±0.622 (P<0.001) and the mean for contact VAS pain scores from 7.77±1.57 to 1.31±1.18 (P<0.001). The mean VAS pain scores of the lesions showed statistically significant differences between the follow-up periods compared to the baseline (P<0.001). The process was completely pain-free and required no anesthesia. After NTCLT, no kind of thermal adverse effects such as irritation, destruction, aggravation, and even erythema were observed.Conclusion: Based on the results of this before-after clinical trial, NTCLT has the potential to be considered a non-invasive and safe palliative option for the pain management of patchy OM due to chemotherapy of solid tumor