Impact of continuous positive airway pressure treatment on left atrial volume and function in patients with obstructive sleep apnoea assessed by real-time three-dimensional echocardiography

Background:

Obstructive sleep apnoea (OSA) has been reported as a predictor of left ventricle (LV) diastolic dysfunction and left atrium (LA) remodelling. The aim of this study is to evaluate the impact of OSA treatment with a continuous positive airway pressure device (CPAP) on the LA volume and function, as well as on the LV diastolic function.

Methods:

In total, 56 OSA patients were studied. All patients underwent real-time three-dimensional (RT3DE) and two-dimensional echocardiogram with tissue Doppler evaluation in order to estimate LA volumes, function and LV diastolic performance. A total of 30 patients with an apnoea-hypopnoea index greater than 20 were randomly selected to receive sham CPAP (n = 15) or effective CPAP (n = 15) for 24 weeks. They underwent echo examination on three different occasions: at baseline, after 12 weeks and 24 weeks of CPAP or sham CPAP.

Results:

In the effective CPAP group we observed the following changes from the baseline to the 24-week echo evaluation: (a) a reduction in the E/E′ ratio (10.3 (1.9) to 7.9 (1.3), p = 0.03); (b) an increase in the LA passive emptying fraction (28.8% (11.9%) to 46.8% (9.3%), p = 0.01); and (c) a reduction in the LA active emptying fraction (42.7% (11.5%) to 25.7 (15.7), p<0.01). In the sham group, there were no changes from the baseline to the 24-week echo. We found a positive correlation between 24 week/baseline LA active emptying volume and 24 week/baseline E/E′ ratios (r = 0.40, p<0.05) and a negative correlation between 24 week/baseline LA passive emptying volume and 24 week/baseline E/E′ ratios (r = −0.53, p<0.05). No significant changes were found on LA total emptying fraction.

Conclusion:

CPAP improved LV diastolic function and LA passive emptying, but not LA structural variables in OSA patients.

Trial registration number:

NCT00768807.

Comparing compression models for authorship attribution

In this paper we compare different compression models for authorship attribution. To this end, three different types of compressors, Lempel-Ziv type (GZip), block sorting type (BZip) and statistical type (PPM), along with two different similarity measures were considered in our experiments. Besides, two different attribution methods are analyzed in this paper. Through a series of experiments performed on two different databases, we were able to show that all the compressors behave similarly, but the similarity measures can vary considerably depending on the strategy used for authorship attribution. Our results corroborate with the literature in the sense that compression models are a good alternative for authorship attribution surpassing traditional pattern recognition systems based on classifiers and feature extraction.

Buccal Bullfrog (Rana catesbeiana Shaw) Oil Emulsion: A Mucoadhesive System Intended for Treatment of Oral Candidiasis

Oral candidiasis (OC) is an infectious disease caused by microorganisms of the genus Candida, leading to lesions in the buccal cavity. Its treatment consists of the administration of topical or systemic antifungal agents, which may compromise the patient compliance due to its side effects, highlighting the need for alternative treatments. In this scenario, bullfrog oil, an animal oil composed of a pool of saturated and unsaturated fatty acids, is introduced as a potential antifungal raw material. Thus, the aim of this work was to produce a mucoadhesive emulsified system able to deliver the bullfrog oil in the buccal cavity to treat the OC. The emulsion was produced and characterized by visual inspection, droplet size, polydispersity index (PdI), and zeta potential over the course of 60 days. In addition, its mucoadhesive ability was evaluated using an in vitro mucin model. The antifungal activity, evaluated by the broth microdilution assay and the biocompatibility, performed against human erythrocytes, were also carried out. The emulsion showed a droplet size of 320.79 ± 35.60 nm, a PdI of 0.49 ± 0.08, and a zeta potential of -38.53 ± 6.23 mV, with no significant changes over 60 days. The mucoadhesive properties of the system was improved by the use of pharmaceutical excipients. The antifungal activity showed that the bullfrog oil and the emulsion were able to inhibit the growth of different Candida species. Furthermore, the emulsion showed no significant hemolytic effect. Overall, the system showed suitable physicochemical characteristics and biocompatibility, with substantial in vitro antifungal activity, suggesting that this system can be further investigated for OC treatment.

0804 Sleep Bruxism, Awake Bruxism and Sleep Related Breathing Disorders in Adults With Down Syndrome

Introduction

To our knowledge, no studies have accessed theawake bruxism (AB) and stage by stage sleep bruxism (SB) in adults with Down syndrome. Recent works have shown that portable PSG systems are accurate for SB assessment even in the absence of audio-video recording. We aimed to evaluate the prevalence of awake bruxism, stage-by-stage sleep bruxism and Sleep Related Breathing Disorders (SRBD) in adults with Down syndrome.

Methods

Twenty-three adults with Down Syndrome (DS) were enrolled in this study. General health, dental status, parafunctional habits and temporomandibular symptoms were assessed. The history of SB/AB was taken from a questionnaire to the caregivers. A portable PSG type II system (Embla Embletta MPR+PG ST+Proxy, Natus, California-USA) was used to perform a full-sleep study at patients’ home. RMMA activity was defined as low (&gt;1 and &lt;2 episodes/h of sleep), moderate (&gt;2 and &lt;4 episodes/h of sleep), or high (&gt;4 episodes/h of sleep). PSG diagnose of SB was assumed if RMMA index was &gt;2 episodes/h of sleep.

Results

According to caregiver’s report, AB was present in all patients whereas only 13.1% had SB. PSG records showed a SB prevalence of 91.3%, with a mean RMMA index 40.0±30.0/h. Only 2 (8,7%) showed RMMA index of 0.0/h. SB episodes were predominant in N3 and REM sleep stage in 14 and 9 patients, respectively. All but one (95,7%) patient (isolated snoring) presented with OSA (AHI=32.8±28.6). A unique TMD symptom (pain on palpation) was present in 8,7% of the global sample.

Conclusion

The high prevalence of “definitive SB” together with the high prevalence of OSA and snoring point in favor to the recommendation of routine PSG in adults with DS. Furthermore, the low sensitivity of parent-oriented questionnaires reinforces the need of more accurate assessment tools in order to get a better standard of care in this particular group of patients.

Support

State of Sao Paulo Research Support Foundation - FAPESP grant number: 2017/06835-8

[Chagas disease in a rural area of Northeast Brazil]

A serological and medical survey on Chagas disease was carried out between December 1997 and June 2000 in four villages of the semi-arid rural Northeast Brazil. The average human serological prevalence rate of 11.8% was strongly linked with age: 1.1% for people under 25, 13.7% for people aged of 26 to 49, 29.5% for people aged of 50+. The clinical form was indeterminate for 57% of the infected population, cardiac for 35%, digestive or mixed for 8%. The infected patients under 55 received at home an etiologic treatment with benznidazol. The survey confirms the drastic reduction of Trypanosoma cruzi transmission during the last decades, especially since 25 years. This situation is the result jointly of the antivectorial activities, improvement of education level and changes in the way of life. However Chagas disease is still a serious problem, especially for numerous middle-aged infected adults. The situation could be improved by increasing the serologic screening in the field as well as the counselling and the treatment of the patients.

0657 Impact of Treatment With Mandibular Advancement Oral Appliance on Respiratory Parameters, Sleep and Cardiometabolic Risk Factors of CPAP Non-Adherent Patients With Severe Obstructive Sleep Apnea

Introduction

Obstructive sleep apnea (OSA) may trigger systemic changes linked to important cardiometabolic risk factors such as hypertension, stroke and diabetes II. As a life-threatening, multifactorial disorder, OSA demands a multiprofessional approach. The most common worldwide treatments are Continuous Positive Airway Pressure (CPAP) and Mandibular Advancement Oral Appliance (OAm). The aim of this study was to evaluate the impact of OAm treatment on CPAP non-adherent patients with severe OSA, comparing objective and subjective data between baseline and follow up.

Methods

A prospective study was carried out including non-adherent severe OSA patients, which were referred to OAm therapy evaluation. Patients presenting with snoring, gasping/choking during sleep, fatigue and daily sleepiness were evaluated by a sleep medicine specialist and the diagnosis of severe OSA with a basal polysomnography (PSG). All the patients were treated with a standard OAm (PMPositioner®). Baseline and Follow up (6 months) sleep parameters (PSG and Epworth Sleepiness Scale - ESS) were compared to assess treatment efficacy.

Results

Seventeen patients (9 with hypertension and 8 with hypertension + diabetes) met the inclusion criteria and 13 finished the protocol. After treatment with OAm the following parameters improved significantly: OSA severity (44.5±13.5 to 9.0±4.3, p≤0.001), ODI (46.8±11.6 to 12.1±9.1(p&lt;0.05)), REM (18.4± 4.8 to 21.5± 2.9 (p&lt;0.05)) and SaO2nadir (75.7± 9.4 to 87.0±3.6, p&lt;0.001), ESS (p&lt;0.005). Ten patients (58%) reported a reduction either in systolic and diastolic blood pressure with 3 of them (30%) reduced the hypertensive drug dose.

Conclusion

Our findings show that OAm is a safe and effective treatment option to CPAP non-adherent severe OSA patients. Furthermore OAm therapy had also a positive impact on cardiometabolic risk factors which are particularly relevant outcomes in OSA patients.

Support

State of Sao Paulo Research Support Foundation (FAPESP).

Beyond Traditional Sunscreens: A Review of Liposomal-Based Systems for Photoprotection

Sunscreen products are essential for shielding the skin from ultraviolet (UV) radiation, a leading cause of skin cancer. While existing products serve this purpose, there is a growing need to enhance their efficacy while minimizing potential systemic absorption of UV filters and associated toxicological risks. Liposomal-based formulations have emerged as a promising approach to address these challenges and develop advanced photoprotective products. These vesicular systems offer versatility in carrying both hydrophilic and lipophilic UV filters, enabling the creation of broad-spectrum sunscreens. Moreover, their composition based on phospholipids, resembling that of the stratum corneum, facilitates adherence to the skin's surface layers, thereby improving photoprotective efficacy. The research discussed in this review underscores the significant advantages of liposomes in photoprotection, including their ability to limit the systemic absorption of UV filters, enhance formulation stability, and augment photoprotective effects. However, despite these benefits, there remains a notable gap between the potential of liposomal systems and their utilization in sunscreen development. Consequently, this review emphasizes the importance of leveraging liposomes and related vesicular systems as innovative tools for crafting novel and more efficient photoprotective formulations.