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.

The Determination of Procalcitonin Concentration in Early-Onset Neonatal Infection.

The aim of this study was to assess the clinical usefulness of blood procalcitonin (PCT) levels for the diagnosis and therapeutic monitoring of early-onset neonatal sepsis (EONS). PCT as well as C-reactive protein (CRP) levels and white blood cell (WBC) count were measured in venous blood from 57 infected and 72 uninfected neonates. Differences between groups for PCT, CRP, and WBC levels were significant. The threshold value on the receiver operating characteristic curve in the prediction of EONS was 5.33 ng/mL for PCT, 9.3 mg/L for CRP, and 14.9 × 109/L for WBC. There was no effect of antibiotic administered to the mother on PCT, CRP, and WBC levels in neonatal blood sampled before treatment of EONS. Evidently reduced PCT levels are observed after 2 days of treatment. The authors conclude that prenatal antibiotic therapy does not reduce the value of PCT levels in blood for the diagnosis of EONS.

The Effect of an Eextremely Low Frequency Magnetic Field on Larvae Production in the Parasite-Host System: Fasciola hepatica-Galba truncatula: a Preliminary Study.

The aim of this study was to determine the effect of an extremely low-frequency magnetic field (ELFMF) on the production of liver fluke larvae in a parasite-host system: Fasciola hepatica--Galba truncatula. Both F. hepatica eggs and F. hepatica-infected snails were exposed to an ELFMF (50 Hz, 2.0 mT) for 14 days and 36 days, respectively. F. hepatica-infected snails were divided into 4 groups, 10 specimens each. The snails of groups I and II were infected with F. hepatica larvae--miracidia obtained from control cultures, while the snails of groups III and IV were infected with miracidia reared from eggs that had been incubated in an ELFMF. After infection, the snails of groups II and IV were placed in an ELFMF, while those of groups I (control) and III were housed outside the ELFMF. At 36 days post-infection (dpi) there were no statistically significant differences between the number of F. hepatica larvae--cercariae and metacercariae, obtained from G. truncatula snails in the control group (group I) and the snail groups exposed to ELFMF (groups II, III and IV). However, a statistically significant difference between the average number of F. hepatica larvae in snail groups III and IV may indicate that the duration of exposure to ELFMF, i.e. embryogenesis period vs. the entire larval development, played a role in the production of F. hepatica larvae, and resulted in a reduction of their number.

Usefulness of estimation of blood procalcitonin concentration versus C-reactive protein concentration and white blood cell count for therapeutic monitoring of sepsis in neonates.

AIM: This study was intended to assess the clinical usefulness of blood procalcitonin (PCT) concentrations for the diagnosis and therapeutic monitoring of nosocomial neonatal sepsis. MATERIAL/METHODS: The enrolment criterion was sepsis clinically manifesting after three days of life. PCT concentrations were measured in venous blood from 52 infected and 88 uninfected neonates. The results were interpreted against C-reactive protein (CRP) concentrations and white blood cell counts (WBC). RESULTS: Differences between the two groups in PCT and CRP concentrations were highly significant. No significant differences between the groups were noted for WBC. The threshold value on the receiver operator characteristic curve was 2.06 ng/mL for PCT (SE 75%; SP 80.68%; PPV 62.22%; NPV 88.75%; AUC 0.805), 5.0 mg/L for CRP (SE 67.44%; SP 73.68%; PPV 42.02%; NPV 88.89%; AUC 0.801), and 11.9 x109/L for WBC (SE 51.16%; SP 50.68%; PPV 23.16%; NPV 78.13%; AUC 0.484). Procalcitonin concentrations decreased 24 hours after initiation of antibiotic therapy and reverted to the control level after 5-7 days. C-reactive protein concentrations began to decline after two days of antibiotic therapy but were still higher than in the control group after 5-7 days of treatment. No significant changes in WBC during the treatment were observed. CONCLUSIONS: Procalcitonin concentrations in blood appear to be of use for the diagnosis and therapeutic monitoring of nosocomial infections in neonates as this parameter demonstrates greater sensitivity and specificity than C-reactive protein. White blood cell counts appear to be of little diagnostic value in the early phase of infection or for therapeutic monitoring.

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.

Recording of amplitude-integrated electroencephalography, oxygen saturation, pulse rate, and cerebral blood flow during massage of premature infants.

OBJECTIVE: Stimulation of the nervous system plays an important role in brain function and psychomotor development of children. Massage can benefit premature infants, but has limitations. STUDY DESIGN: The authors conducted a study to verify the direct effects of massage on amplitude-integrated electroencephalography (aEEG), oxygen saturation (SaO(2)), and pulse analyzed by color cerebral function monitor (CCFM) and cerebral blood flow assessed by the Doppler technique. RESULTS: The amplitude of the aEEG trend during massage significantly increased. Massage also impacted the dominant frequency δ waves. Frequency significantly increased during the massage and return to baseline after treatment. SaO(2) significantly decreased during massage. In four premature infants, massage was discontinued due to desaturation below 85%. Pulse frequency during the massage decreased but remained within physiological limits of greater than 100 beats per minute in all infants. Doppler flow values in the anterior cerebral artery measured before and after massage did not show statistically significant changes. Resistance index after massage decreased, which might provide greater perfusion of the brain, but this difference was not statistically significant. CONCLUSION: Use of the CCFM device allows for monitoring of three basic physiologic functions, namely aEEG, SaO(2), and pulse, and increases the safety of massage in preterm infants.

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.

Does prenatal antibiotic therapy compromise the diagnosis of early-onset infection and management of the neonate?

AIM: To assess the impact of prenatal antibiotic treatment on procalcitonin (PCT) and C-reactive protein (CRP) concentrations in cord blood, and on the rate of positive neonatal blood cultures. METHODS: Neonates with early-onset infection (Group A; n=46) were compared with healthy controls (Group B; n=240). We evaluated the relationship between prenatal antibiotic therapy and early-onset infection, and for interactions with antibiotic therapy in the neonate immediately after birth. RESULTS: In the Group A antibiotics were administered significantly more often prenatally and more often to neonates just after birth. The percentage of negative blood cultures in infected neonates was higher when antibiotic treatment was instituted prenatally. Differences in cord blood PCT and CRP concentrations were significant between both groups and were independent of prenatal antibiotic treatment. Streptococcus agalactiae was the most frequent species. CONCLUSIONS: Almost one-third of neonates present with early-onset infection in spite of prenatal antibiotic therapy. Cord blood PCT and CRP measurements may be helpful in the diagnosis of infection also in cases when antibiotic therapy was started prenatally. Prenatal antibiotic administration reduced the number of positive blood cultures in neonates with early-onset infection and was associated with a greater rate of antibiotic treatment after birth in neonates without infection.

Extremely low frequency magnetic field and the hatching rate of Fasciola hepatica eggs, the fecundity and survival of liver fluke-infected snail, Lymnaea truncatula.

Eggs of Fasciola hepatica were exposed for 10 days to extremely low frequency magnetic field (ELFMF) at the frequency of 50 Hz and density of 2 mT (rms). The results show an accelerated hatching of F. hepatica eggs in relation to control (non-exposed) group. The host snails, Lymnaea truncatula, were divided into three groups; those of groups I and II were infected with the miracidia of F. hepatica hatched from control egg culture, whereas those of group III were infected with miracidia hatched from eggs affected by ELFMF. Thereafter, snails of groups II and III were exposed to ELFMF for 53 days, whereas those of group I were not exposed. At day 14 post infection, a significant decrease was observed in the number of cocoons laid by snails of group III, compared with control. Also, significant mortality in group III snails was observed 42 days post infection. The increased mortality and a lower number of cocoons laid by group III snails have probably resulted from enhanced stimulation of metacercarial parthenogenetic reproduction in consequence of infecting the molluscs with miracidia reared under ELFMF.

Early detection of an early onset infection in the neonate based on measurements of procalcitonin and C-reactive protein concentrations in cord blood.

BACKGROUND: The aim of this study was to test the diagnostic model of combining procalcitonin (PCT) and C-reactive protein (CRP) levels in the cord blood and routinely used biochemical parameters and clinical data in the prediction of early onset neonatal infection. METHODS: PCT and CRP concentrations were measured in cord blood of neonates with infection (group A, n=46) and compared with uninfected neonates (group B, n=240). Inclusion criteria for group A were based on obstetric history, clinical data and results of laboratory tests. Logistic regression was applied. The receiver operating characteristic (ROC) curves were constructed for PCT, CRP and the diagnostic model. RESULTS: There was a highly significant (p<0.000001) difference in PCT and CRP concentrations between both groups. The cut-off point for PCT in cord blood was 1.22 ng/mL [sensitivity % (SE%) 80.43, specificity % (SP%) 71.67, positive predictive value % (PPV%) 35.24, negative predictive value % (NPV%) 95.03], and 1.0 mg/L for CRP (SE% 73.91, SP% 77.92, PPV% 39.08, NPV% 93.97). In total, seven variables were included in the model (concentrations of PCT and CRP in cord blood, tocolysis, nutritional status of the newborn, Apgar score, neutrophil ratio and red blood cell count in neonatal venous blood), which proved to offer the highest sensitivity (91.3%; 95% CI: 83-99) and specificity (90%; 95% CI: 86-94) for the detection of early onset neonatal infection. The likelihood ratio for the model was high at 9.13, with PPV% 63.64 (95% CI: 52-75), NPV% 98.18 (95% CI: 96-100) and calculated area under the curve at 0.973. CONCLUSIONS: The diagnostic model based on seven clinical and laboratory parameters, using the concentration of PCT and CRP measurements in the cord blood, could be a useful tool for the prediction of early onset neonatal infection.

Reliability of semiquantitative determination of procalcitonin serum concentrations in neonates.

We studied the diagnostic usefulness of semiquantitative determination of procalcitonin (PCT) concentrations in neonatal serum by reference to a quantitative method. We compared 302 results of PCT measurements in 151 samples of venous blood collected during the 1st 7 days of life. The semiquantitative BRAHMS PCT-Q test and the quantitative immunoluminometric LUMItest were compared with Cohen's kappa as a measure of concordance. Concordance was revealed for 28.4% of samples, whereas 11.9% showed total disagreement. Concordance between both methods reached 88% when results from the next (lower or higher) category were included. The weighted kappa value was 0.235, indicative of satisfactory agreement between both methods. The semiquantitative BRAHMS PCT-Q test reveals satisfactory concordance with the quantitative method when results in the next category are included to account for readout error. The semiquantitative test is rapid, easy to use, and helpful as a supportive test when the quantitative assay is not available.

Umbilical cord blood serum procalcitonin concentration in the diagnosis of early neonatal infection.

OBJECTIVE: To evaluate serum procalcitonin concentration in umbilical cord blood for diagnosis of intrauterine bacterial infection. MATERIALS AND METHODS: A prospective study was conducted between 2000 and 2001. Serum procalcitonin concentrations were evaluated in 187 umbilical cord blood samples. Five groups have been defined: controls A (n=37), full-term noninfected B1 (n=80) and infected neonates B2 (n=8), preterm noninfected C1 (n=38) and infected C2 (n=24) newborns. An immunoluminometric assay was used to determine procalcitonin concentration. The Mann-Whitney U-test and Spearman's correlation ratio were applied. The sensitivity and specificity, the positive and negative predictive values, and the area under receiver operating characteristic curves were calculated. RESULTS: A statistically higher serum procalcitonin concentration was found in the preterm infected group (p<0.005; C2 vs A and C1). CONCLUSION: Serum procalcitonin concentration in umbilical cord blood may be a useful parameter in the diagnosis of early neonatal infection.