Τρίτη 14 Φεβρουαρίου 2023

Nonlinear absorption‐based analysis of energy deposition in melanosomes for 532‐nm short‐pulsed laser skin treatment

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Abstract

Background and Objectives

The clinical use of 532-nm short-pulsed lasers has provided effective treatment of epidermal pigmented lesions. However, the detection of significant differences in treatment effects between picosecond and nanosecond lasers has still varied among clinical studies. For robust evaluation of the differences based on the treatment mechanism, this study presents a nonlinear absorption-based analysis of energy deposition in melanosomes for 532-nm short-pulsed laser treatment.

Study Design/Materials and Methods

Nonlinear absorption by melanin is modeled based on sequential two-photon absorption. Absorption cross-sections and nonradiative lifetimes of melanin, which are necessary for the nonlinear absorption-based analysis, are determined from transmittance measurement. Using the model and parameters, energy deposition in melanosomes was calculated with varying fluence and pulse width settings, including actual clinical parameters.

Results

The energy deposition in melanosomes increased with shorter laser pulses, and subnanosecond laser pulses were found to be most efficient. The comparison of energy deposition calculated using clinical parameters demonstrated the differences in treatment effects between picosecond and nanosecond lasers reported in clinical studies.

Conclusion

The nonlinear absorption-based analysis provides quantitative evidence for the safety and efficacy evaluation of short-pulsed laser treatments, which may lead to the establishment of numerical indices for determining treatment conditions. Future studies considering the effects of the surrounding tissue on energy deposition in melanosomes will be needed.
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Mitigating the return of acute respiratory virus infections

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Over the past two years, many countries have seen low levels of acute respiratory virus infection (ARVIs), a collective term for all respiratory viruses that infect humans, except for SARS-CoV-2. With the cessation of non-pharmacological interventions across many countries, SARS-CoV-2 continues to circulat e and the incidences of influenza, respiratory syncytial virus (RSV), and other respiratory viruses have increased this winter. For instance, Australia has recently experienced one of its most severe influenza seasons on record.1 In the US in November 2022, the Centers for Disease Control and Prevention (CDC) issued a health alert notice due to a surge in respiratory virus activity. Hospital admissions in the US related to influenza are at the highest levels in 10 years, and an early, severe spike in RSV cases resulted in considerable pressures on paediatric hospital beds.2There are several explanations for why this has happened. Firstly, most populations had little exposure to acute...
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Evaluation of the effectiveness of maternal immunization against pertussis in Alberta using agent-based modeling: A Canadian immunization research network study

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via Vaccine

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CONCLUSIONS: Our model predicts significant reduction in future pertussis cases in infants due to maternal vaccination, with immunological blunting slightly moderating its effectiveness. The model is most sensitive to maternal vaccination coverage. The interruption of exposure pathways plays a role in the reduction of pertussis burden in infants due to maternal immunization. The effect of maternal immunization on population other than infants remains to be elucidated.PMID:36775775 | DOI:10.1016/j.vaccine.2022.12.071 (Source: Vaccine)
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Prognostic significance of soft tissue deposits in head and neck squamous cell carcinoma: a systematic review and meta-analysis

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Soft tissue deposits, also known as tumour deposits (TDs), have not been studied well in head and neck squamous cell carcinoma (HNSCC) and are not included in any of the staging systems or treatment guidelines. The aim of this systematic review was to determine the prevalence and prognostic implications of TDs in patients with HNSCC. This systematic review of the literature was conducted following the PRISMA guidelines. The PubMed, Embase, and Scopus electronic databases were searched for relevant studies, from inception to August 2022. (Source: International Journal of Oral and Maxillofacial Surgery)
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MRI Investigation of the Differential Impact of Left Ventricular Ejection Fraction After Myocardial Infarction in Elderly vs. Nonelderly Patients to Predict Readmission for Heart Failure

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Background

Patients with ST-segment elevation myocardial infarction (STEMI), especially elderly individuals, have an increased risk of readmission for acute heart failure (AHF).

Purpose

To study the impact of left ventricular ejection fraction (LVEF) by MRI to predict AHF in elderly (>70 years) and nonelderly patients after STEMI.

Study Type

Prospective.

Population

Multicenter registry of 759 reperfused STEMI patients (23.3% elderly).

Field Strength/Sequence

1.5-T. Balanced steady-state free precession (cine imaging) and segmented inversion recovery steady-state free precession (late gadolinium enhancement) sequences.

Assessment

One-week MRI-derived LVEF (%) was quantified. Sequential MRI data were recorded in 579 patients. Patients were categorized according to their MRI-derived LVEF as preserved (p-LVEF, ≥50%), mildly reduced (mr-LVEF, 41%–49%), or reduced (r-LVEF, ≤40%). Median follow-up was 5 [2.33–7.54] years.

Statistical Tests

Univariable (Student's t, Mann–Whitney U, chi-square, and Fisher's exact tests) and multivariable (Cox proportional hazard regression) comparisons and continuous-time multistate Markov model to analyze transitions between LVEF categories and to AHF. Hazard ratios (HR) with 95% confidence intervals (CIs) were computed. P < 0.05 was considered statistically significant.

Results

Over the follow-up period, 79 (10.4%) patients presented AHF. MRI-LVEF was the most robust predictor in nonelderly (HR 0.94 [0.91–0.98]) and elderly patients (HR 0.94 [0.91–0.97]). Elderly patients had an increased AHF risk across the LVEF spectrum. An excess of risk (compared to p-LVEF) was noted in patients with r-LVEF both in nonelderly (HR 11.25 [5.67–22.32]) and elderly patients (HR 7.55 [3.29–17.34]). However, the mr-LVEF category was associated with increased AHF risk only in elderly patients (HR 3.66 [1.54–8.68]). Less transitions to higher LVEF states (n = 19, 30.2% vs. n = 98, 53%) and more transitions to AHF state (n = 34, 53.9% vs. n = 45, 24.3%) were observed in elderly than nonelderly patients.

Data Conclusion

MRI-derived p-LVEF confers a favorable prognosis and r-LVEF identifies individuals at the highest risk of AHF in both elderly and nonelderly patients. Nevertheless, an excess of risk was also found in the mr-LVEF category in the elderly group.

Evidence Level

2.

Technical Efficacy

Stage 2.
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QSM Throughout the Body

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Magnetic materials in tissue, such as iron, calcium, or collagen, can be studied using quantitative susceptibility mapping (QSM). To date, QSM has been overwhelmingly applied in the brain, but is increasingly utilized outside the brain. QSM relies on the effect of tissue magnetic susceptibility sources on the MR signal phase obtained with gradient echo sequence. However, in the body, the chemical shift of fat present within the region of interest contributes to the MR signal phase as well. Therefore, correcting for the chemical shift effect by means of water-fat separation is essential for body QSM. By employing techniques to compensate for cardiac and respiratory motion artifacts, body QSM has been applied to study liver iron and fibrosis, heart chamber blood and placenta oxygenation, myocardial hemorrhage, atherosclerotic plaque, cartilage, bone, prostate, breast calcification, and kidney stone.
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Use of a novel body mandibular plane (mental foramen–protuberance menti) in analyzing mandibular asymmetry compared with conventional border mandibular plane

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ABSTRACT
Objectives
To compare a novel body mandibular horizontal plane (mental foramen–protuberance menti; Body-MHP) with the conventional border mandibular horizontal plane (gonion–menton [Me]; Border-MHP) to assess mandibular body inclination and dental compensation of skeletal Class III patients with and without facial asymmetry.
Materials and Methods
Retrospective data obtained from diagnostic cone-beam computed tomography of 90 skeletal Class III patients (mean age, 21.67 ± 2.93 years; range, 15.0–30.6 years) were divided into symmetry (n = 30) and asymmetry groups (n = 60). The asymmetry group was subdivided into roll (n = 30) and non-roll types (n = 30). The differences in body inclination and dental measurements (distance and angle) according to two mandibular planes (Body-MHP and Border-MHP) were assessed in the groups and subgroups.
Results
Mandibular body inclinations relative to the Body-MHP were not different in the roll-type asymmetric mandibl e between the sides, while those relative to the Border-MHP were different (P < .001). For the mandibular first molar positions relative to the Border-MHP, the differences in vertical distance between the sides were undermeasured and the inclination differences were overmeasured when compared relative to the Body-MHP.
Conclusions
The Body-MHP demonstrated better bilateral similarity in body inclination compared with the Border-MHP in patients with roll-type facial asymmetry. The novel body mandibular plane ensures an accurate diagnosis for tooth movement and jaw surgery, particularly in the roll-type asymmetric mandible.
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Phylogenetic origin of Helicobacter pylori pathogenicity island and risk of stomach cancer and high-grade premalignant gastric lesions

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imageInfection by Helicobacter pylori (Hp) has been causally linked to risk of gastric cancer (GC). The coevolution of Hp and humans shaped the risk of GC as our species left Africa and migrated to the other continents. Latin America (LatAm) is a high GC incidence region where Hp evolved uniquely in the 500 years since European colonization. Differential virulence of the Hp cagA-pathogenicity island (cagPAI) by ancestral origin has been reported. We hypothesized that Hp phylogenetic origin might play a role in determining GC risk in LatAm. We used genotypes of 50 Hp genetic variants mapping to the Hp cagPAI, studied in 1220 subjects from Venezuela, Colombia, Mexico and Paraguay, who were infected with cagA-positive Hp, including 150 GC, 177 high-grade premalignant lesions (HGPMLs) and 893 low-grade premalignant lesions. We estimated the phylogenetic origin of Hp cagPAI in all study subjects by use of the STRUCTURE software and principal component analysis (PCA) and tested whether the estimated African ancestry percentage was associated with the risk of GC or HGPML. African ancestral component estimates by STRUCTURE and PCA were highly correlated. STRUCTURE-based African origin estimate was not significantly associated with the risk of HGPML, but it was inversely associated with GC risk: the OR associated with the continuous values of African component was 0.09 (95% CI, 0.01–0.85; P = 0.035). Simi lar trends were observed for GC with PCA-based estimates, but the association was not statistically significant. These results suggest that Hp ancestral origin may play a role in gastric carcinogenesis.
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Participation in breast cancer screening and its influence on other cancer screening invitations: study in women aged 56 years old in four French departments

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imageBackground Today, women 50 years of age are offered three types of cancer screening in France. However, participation is not optimal. The aim was to describe (1) participation in organised breast cancer screening (OS) of women aged 56 years old, and the influence of this participation on colorectal and cervical cancer screening, (2) the reasons for non-participation in breast cancer OS, and (3) the reasons for screening before age 50. Methods A questionnaire was sent to 56-year-old women in four French departments to identify their participation behaviour in three breast cancer OS invitations and their reasons for non-participation. Three groups were determined according to the number of participations in breast cancer OS (3, 1–2 and 0). We described the quantitative responses and grouped the qualitative responses thematically. Results A total of 4634 women responded to the questionnaire. Seventy-six percent had undergone all three breast cancer OS, 16% irregular and 7% non-participant. Among women who irregularly perform breast cancer OS, 50.5% also irregularly perform colorectal cancer OS. Women who participated in all three invitations for the breast cancer OS performed more smear tests than women in the other groups. Many of the irregular participants or non-participants underwent opportunistic screening, often initiated before the age of 50. The reasons for non-participation in breast cancer OS were mainly medical or participation in opportunistic screening. Conclusion There is no fundamental opposition to participation in breast cancer screening. However, it remains of the utmost importance that women should be better informed about OS and its benefits.
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