Taste dysfunction after COVID-19: Analysis with functional near-infrared spectroscopy.

<br><b>Introduction:</b> According to official data, COVID-19 emerged in China in December 2019 and has spread worldwide since then.</br> <br><b>Aim:</b> The aim of this study was to investigate differences in functional near-infrared spectroscopy (fNIRS) recordings between convalescent COVID-19 patients and a healthy control group, which could help to clarify the pathomechanism of dysgeusia in COVID-19.</br> <br><b>Material and methods:</b> The study included 16 participants, comprised of 8 convalescent COVID-19 patients and 8 healthy controls. All participants were examined with fNIRS. The amplitude of changes in oxyhemoglobin (oxyHb) concentration in the cerebral cortex was analyzed statistically (for the test and control groups after stimulation with a taste stimulus - citric acid solution).</br> <br><b>Results:</b> The differences in the amplitude of changes in oxyHb concentration in the cerebral cortex were not statistically significant between the groups. Discussion: Using fNIRS, a strong stimulation of the visual cortex was discovered in response to the taste stimulus, consisting of large, repetitive changes in oxyHb concentration occurring in parallel with stimulation of areas of the taste cortex. This phenomenon has not, to our knowledge, been described previously in the scientific literature. The exact location of the primary taste cortex is controversial, but to date the occipital cortex has not been considered to be involved.</br> <br><b>Conclusions: No difference was observed in the dynamics of changes in oxyHb in the examined areas of the cerebral cortex between convalescent COVID-19 patients and healthy controls. However, the determination of the role of the occipital cortex in the perception of taste requires further research.</br>.

Searching for the Mechanism of Action of Extremely Low Frequency Electromagnetic Field-The Pilot fNIRS Research.

There is an ongoing debate on the benefits of magnetic stimulation in neurological disorders. OBJECTIVES: We aimed to evaluate the influence of magnetic stimulation on blood oxygenation of the motor cortex using functional near-infrared spectroscopy (fNIRS). METHODS: A total of 16 healthy volunteer participants were subjected to four protocols. In the first two protocols, the participants remained at rest without (and then with) magnetic stimulation. In the next two protocols, motor cortex stimulation was achieved using a finger-tapping task, with and without magnetic stimulation. Changes in blood oxygenation levels within the motor cortex were recorded and analysed. RESULTS: No characteristic changes in the blood oxygenation level-dependent responses were observed in resting participants after magnetic stimulation. No statistically significant difference was observed in the amplitude of the fNIRS signal before and after magnetic stimulation. We observed characteristic blood oxygenation level-dependent responses after the finger-tapping task in the second protocol, but not after magnetic stimulation. CONCLUSIONS: Although we did not observe any measurable effect of the magnetic field on the haemodynamic response of the motor cortex, understanding the mechanism(s) of magnetic stimulation may be important. Additional, detailed studies are needed to prove or negate the potential of this medical procedure.

Influence of Freeze-Dried Diet on Oral Hygiene Indicators in Strict Isolation Condition of an Analog Space Mission.

Analog space missions were created to study the human factor in extraordinary conditions that would occur in future space habitats. Isolation has been shown to cause stress and disrupt individuals' daily routine, which can also affect their oral hygiene and lead to an increased risk of dental caries and gingivitis. The astronauts' specific freeze-dried diet is associated with "lazy" chewing, potential dehydration and vitamin A deficiency, which may adversely affect their saliva. The aim of this study is to investigate the influence of the freeze-dried diet on selected oral hygiene indicators in analog astronauts (AA) enduring strict isolation conditions during six consecutive analog space missions at the LunAres Research Station. During the experiment the oral hygiene and gingival inflammation status measurements were conducted on the group of AAs at the beginning and at the end of each mission. Measurements included four oral hygiene indicators: API, sOHI, PI by Silness and Loe and GBI by Ainamo and Bay. Each AA's individual scores were noted and analyzed. Statistically significant reduction in the amount of plaque and intensity of gingival bleeding was observed over the course of the study, which could indicate positive results of applied oral hygiene procedures despite unfavorable dietary and stressful isolation conditions.

The effect of ionising radiation on the physical properties of 3D-printed polymer boluses.

In recent years, a method for designing radiotherapy boluses using 3D printing technology has been established in the West Pomeranian Oncology Centre in Szczecin, Poland. The aim of the present study was to investigate whether the ionising radiation used in radiotherapy affects the physical properties of the printing material. Particularly, the purpose of this study was to determine the effect of a 60 Gy X-ray radiation dose on the hardness and dimensions of 3D-printed boluses. Four cuboids were printed on a Zortrax M200 printer with acrylonitrile-butadiene-styrene (ABS) polymer. All printed samples were exposed to 60 Gy of X-ray radiation delivered by a medical accelerator. After irradiation, changes in the hardness (using Vickers test) and dimensions of the prints were measured. The therapeutic X-ray dose had a minimal effect on the dimensions of the printed samples, resulting in a maximum contraction of only 0.4%. Changes of the hardness were not statistically significant. In conclusion, regarding the radiotherapy planning process, the application of this therapeutic X-ray dose does not significantly influence the hardness and dimensions of ABS-printed boluses.

High Signal Resolution Pulse Oximetry as a Prognostic Indicator of Radiotherapy Toxicity: A Pilot Study.

INTRODUCTION: Radiotherapy plays a prominent role in the multidisciplinary treatment of cancers. Despite new irradiation techniques, radiation-induced cardiotoxicity remains a leading cause of morbidity and mortality. Therefore, prognostic indicators of radiotherapy toxicity are essential. This study aimed to investigate the influence of applied radiotherapy on the pulse wave recording and thereby on cardiovascular health, as well as to assess whether high signal resolution (HSR) pulse oximetry could be used as a prognostic indicator of radiotherapy toxicity. METHODS: A total of 19 patients treated with radiotherapy to the lung or left breast were analyzed. Pulse oximetry was performed on all eligible patients (before and after the administration of a radiation dose) using the PULS-HSR program, which increases the resolution of the pulse wave recording. RESULTS: Among the analyzed variables, we found the total dose administered to the target, as well as the treatment duration, significantly positively correlated with the change in ventricle/aorta volume ratio. The ventricle/aorta volume ratio parameter is the ratio between the area under the HSR pulse wave generated by the contraction of the left ventricle until the aortic valve closes and the area of the HSR pulse wave responsible for expansion and contraction of the aorta. CONCLUSION: The pilot study indicates HSR pulse oximetry, especially the ventricle/aorta volume ratio parameter, as a potential prognostic indicator of toxicity from radiation for breast and lung cancers.

Evaluation of the rectal V30 parameter in patients diagnosed with postoperative endometrial cancer.

BACKGROUND: The present paper reports on analysis of 184 patients who were diagnosed with endometrial cancer. The main objective of this study was to address parameter Vrec(30Gy) which determines a volume of the rectum irradiated with a dose of 30 Gy during radiotherapy. MATERIALS AND METHODS: All patients were irradiated with an IMRT technique on linear accelerators. The planning target volume (PTV) contour was determined by a radiation oncologist. The clinical target volume (CTV) was drawn on CT images obtained in a prone position. For statistical analysis, appropriate tests (e.g. the Shapiro-Wilk, Wilcoxon) were used. RESULTS AND DISCUSSION: The performed analysis showed that the recommended condition for Vrec(30Gy) is met only in 3% of patients and the observed median value exceeds 90%. The obtained results were compared with the studies in which the Vrec(30Gy) values were related to various radiotherapy techniques. CONCLUSIONS: The analysis showed that the condition for Vrec(30Gy) is satisfied in the case of only 3% of patients. Due to the difficulty with meeting the condition, it should be reconsidered based on real results.

Nursing Care During Neonatal Electroencephalographs.

BACKGROUND: Electroencephalography (EEG) enables the precise evaluation of a neonate's condition. Three factors that determine the quality of care during this procedure are knowledge, experience, and attitude. The role of the nurse during EEG recordings was evaluated in this study, and the requirements for successfully performing neonatal EEGs, along with practical suggestions, are presented. METHODS: Evidence in the literature as well as clinical expertise forms the basis for this review. RESULTS: From our observations and practice during EEGs, we found that the following conditions must be met to successfully perform an EEG examination in a newborn: safety, a period of sleep and calm wakefulness of the neonate, good technical conditions, and no external interferences. Key conditions include the maintenance of safety rules and cooperation between nurses, EEG technicians, and parents. CONCLUSION: The EEG examinations in neonates weighing less than 1500 g or those requiring respiratory support should only be performed by a trained neonatal intensive care unit nurse.

Correlation of Retinopathy of Prematurity with Bronchopulmonary Dysplasia.

Retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD) are diseases that occur only in preterm infants. The etiology of these disorders is multifactorial; however, it is believed that some of the factors in children presenting with BPD affect both the initiation and severity of ROP. The aim of the study was to evaluate the degree of clinical severity of ROP in infants with BPD compared to those without BPD. METHODOLOGY: Infants were divided into two groups: the BPD+ study group and BPD- control group. Parameters including the incidence of ROP and its severity were compared. RESULTS: In neonates with BPD, more severe forms of ROP occurred significantly more frequently than in infants without BPD. Newborns with BPD required significantly longer use of mechanical ventilation; moreover, the number of days in which the concentration of oxygen in the respiratory mixture exceeded 50% was greater in BPD+ children. Children with BPD also received more blood transfusions compared to children without BPD. CONCLUSIONS: Newborns in the BPD+ study group showed advanced stages of ROP more often than newborns in the BPD- control group. The etiology of ROP and BPD is multifactorial; however, our findings suggest oxygen plays a significant role in the development of these diseases.

Utilization of a 3D printer to fabricate boluses used for electron therapy of skin lesions of the eye canthi.

This work describes the use of 3D printing technology to create individualized boluses for patients treated with electron beam therapy for skin lesions of the eye canthi. It aimed to demonstrate the effectiveness of 3D-printed over manually fabricated paraffin boluses. The study involved 11 patients for whom the construction of individual boluses were required. CT scans of the fabricated 3D-printed boluses and paraffin boluses were acquired and superimposed onto patient CT scans to compare their fitting, bolus homogeneity, and underlying dose distribution. To quantify the level of matching, multiple metrics were utilized. Matching Level Index (ML) values ranged from 0 to 100%, where 100% indicated a perfect fit between the reference bolus (planned in treatment planning system) and 3D-printed and paraffin bolus. The average ML (± 1 SD) of the 3D-printed boluses was 95.1 ± 2.1%, compared to 46.0 ± 10.1% for the manually fabricated paraffin bolus. Correspondingly, mean doses were closer to the prescribed doses, and dose spreads were less for the dose distributions from the 3D-printed boluses, as compared to those for the manually fabricated paraffin boluses. It was concluded that 3D-printing technology is a viable method for fabricating boluses for small eye lesions and provides boluses superior to our boluses manually fabricated from paraffin sheets.

EEG, brain maturation, and the development of retinopathy of prematurity.

OBJECTIVES: The factors that influence the central nervous system (CNS) development can affect either the retina or the brain cortex. Immaturity of the brain cortex reflects immaturity of the retina and vice versa. The immature retina is more vulnerable than the mature retina, and is therefore more likely to develop retinopathy of prematurity (ROP). The aim of this study was to compare electroencephalographic brain maturity with ROP severity. METHODS: Twenty-one prematurely born infants were divided into two groups according to the severity of ROP. The first group included 12 infants with ROP stage 3 or more and the second group included nine infants with ROP stage 2 or less. We have proposed an index of CNS maturity (M) as a percentage of interburst interval elongation compared with the norm using video-electroencephalography (vEEG). RESULTS: The median M value was 1.07 (range = 0.43-4.44) for infants with severe ROP and -0.1 (range = -1.0 to 1.45) for infants with mild or no ROP (p = 0.000948). CONCLUSIONS: The study revealed that CNS maturation delay expressed as M value was higher among infants with severe ROP than among infants with mild or no ROP. EEG examination in prematurely born infants may prove to be a useful tool for predicting ROP development.

The role of hemoglobin variant replacement in retinopathy of prematurity.

OBJECTIVE: To conduct tests of relationships between different factors that could influence the course of retinopathy of prematurity (ROP) and ROP, particularly the role of hemoglobin variant replacement in adult blood transfusions. METHODS: A retrospective, observational study of 83 infants born between 23 and 34 wks gestation was conducted. RESULTS: The infants without ROP, with 1 and 2 stage of ROP and with ≥ 3 stage of ROP received Q 28 (12-134); 51 (14-149); 156 (38-244) ml/kg of transfused blood, respectively, and the factor Qt was 1,545 (560-10,045); 3,093 (614-13,419); 11,907 (1,288-20,638) (ml/kg)·day, respectively. For the same groups MCV(35) (mean cell volume at the arbitrary time of the 35(th) wk post-conception) was 92.3 (82.9-110.5); 91.0 (79.3-101.4); 87.1 (80.2-94.8) fl, respectively, and factor P(MCV)/t was 99.5 (89.2-108.8); 96.3 (84.6-106.3); 90.7 (85.3-96.5) fl, respectively. There is high influence on the stage of ROP of the amount of transfused blood and MCV, both with or without the time factor. The statistical differences between P(MCV)/t were more significant than the differences between MCV(35), for different stages of ROP. CONCLUSIONS: The influence of the time factor on the statistical differences of MCV but not on the amount of transfused adult blood suggests that HbF - HbA replacement may play a role in ROP development.