The physiological and disturbing effects of surgical face masks in the COVID-19 era.

BACKGROUND: In the COVID-19 pandemic, the concern about mask-harmful effects disturbed mask-adherence. However, it is not certain whether the masks cause cardiopulmonary overload. OBJECTIVE: To investigate the physiological and disturbing effects of surgical face masks during exercise. METHOD: The study was conducted in a tertiary hospital with 100 healthy volunteers between September 2020 and January 2021. Individuals with impaired walking, cardiopulmonary disease, and smoking were not included in the study. Initially, respiratory rate (RR), heart rate (HR), oxygen saturation (SpO2), end-tidal carbon dioxide (EtCO2) were measured.  Participants underwent 6-minute walking test (6MWT) with and without surgical masks.  Mask-discomfort questionnaire was applied before and after 6 MWT with the mask. RESULTS: Surgical masks during 6 MWTs significantly increased HR, RR, and EtCO2 levels (p<0.001).  Walking distance (p<0.001) and SpO2 level (p=0.002) were significantly decreased with mask. In Mask-Discomfort Questionnaire, humidity, temperature, resistance, salinity, odor, fatigue (p<0.001), and itching (p=0.001) scores significantly increased after 6MWT with mask. CONCLUSION: In healthy volunteers, HR, RR, EtCO2 were increased, and SpO2 and walking distance were decreased in the short-term, light exercise performed with the surgical mask. Findings support the concern that masks may cause cardiopulmonary overload (Tab. 3, Fig. 1, Ref. 17). Text in PDF www.elis.sk Keywords: COVID-19, masks, physiology, psychological side effects, questionnaire.

Importance of acupuncture on premenstrual syndrome.

AIM: Premenstrual syndrome (PMS) is a complex group of symptoms. The clear reasons for PMS have not been understood completely. PMS includes emotional symptoms but mostly physical symptoms. METHODS: The study was carried out on 11 patients (23-40 age range) diagnosed as having PMS. DSM IV was taken into account as the criteria for diagnosis. Ren2, Ren6, Ren12, LI4, LI11, P6, Liv3, Sp6, St36 and Du20 points were used on patients for the effects of acupuncture. The treatment of acupuncture was applied for three menses. Furthermore, NOx, MDA and GSH values in blood were studied. RESULTS: The complaints of patients were observed to decrease or disappear completely. The most obvious changes were observed in myalgia, mastalgia and dysmenorrheal complaints (p < 0.000). Moreover, before starting the treatment of acupuncture, former blood values of NOx, MDA and GSH were compared with blood values of NOx, MDA and GSH after three cycles. An increase was observed for NOx levels after acupuncture treatment (p < 0.05). While there was no change in the oxidant stress indicator, MDA, an increase in antioxidant indicator GSH levels was observed (p < or = 0.05). CONCLUSION: Acupuncture to treat premenstrual syndrome can be considered as an effective treatment modality.

African dust-laden atmospheric conditions activate the trigeminovascular system.

It has been recently noticed that dust originating from deserts can be transported to other continents by the atmosphere and has an adverse effect on public health, such as increased asthma attacks. Dust originating from the Saharan Desert could initiate a series of reactions upon contact with cloud water and results in the formation of reduced iron (Fe(2+)), oxalate and various basic amino acids. We aimed to evaluate whether the simulation of Saharan dust-containing atmospheric conditions could trigger the trigeminovascular system. Freely moving rats incubated within simulated atmospheric conditions containing (i) Saharan dust, (ii) Co(60) gamma ray-treated Saharan dust (sterilized) and (iii) dust-free air, were investigated for the presence of c-fos expression in trigeminal nucleus caudalis (TNC) and for NOx (nitrate+nitrite) levels in blood samples. Atmospheric samples were analysed for microorganisms. Saharan dust-containing atmospheric conditions induced c-fos expression in nociceptive neurons within TNC. The number of c-fos+ neurons in superficial lamina of TNC was significantly higher in the Saharan dust group (32.9 +/- 5.3, P = 0.0001) compared with dust-free air (11.02 +/- 2.7) or Co(60)-treated Saharan dust groups (15.01 +/- 2.4). An increase in NOx levels was detected in blood samples of rats exposed to Saharan dust-containing atmosphere. This study has revealed an unknown environmental factor as a possible trigger for headache. It is the first time that transport of Saharan dust with the atmospheric air stream has been documented to be able to trigger the trigeminovascular system in animals. Further studies are needed to explore the mechanisms and molecules that mediate the nociceptive effect and to guide new treatment strategies.

Increased nitric oxide in exhaled air in patients with rheumatic heart disease.

BACKGROUND: Endogenous production of nitric oxide and its presence in exhaled air was observed in humans. Prior studies have yielded contrasting information about the production of nitric oxide in patients with heart failure. AIMS: The aim of this study was to measure nitric oxide in the exhaled air of patients with chronic rheumatic heart disease with and without pulmonary hypertension. METHODS: Seventy-four patients (6 patients had isolated mitral stenosis; 13 patients had combined mitral stenosis and mitral regurgitation; 1 patient had isolated mitral regurgitation; 54 patients had combined mitral and aortic valve disease) and 27 healthy subjects were entered in the study. The nitric oxide concentration in exhaled air was determined with a chemiluminescence analyser. Echocardiography was performed in all patients to assess the severity of the valve disease and for the measurement of pulmonary artery pressure. RESULTS: The level of exhaled nitric oxide was significantly greater in patients with rheumatic heart disease than in controls. The value of nitric oxide concentration in exhaled air was significantly increased in patients with pulmonary hypertension, as compared with patients who had normal pulmonary artery systolic pressure. CONCLUSION: We found increased nitric oxide in the exhaled air in patients with rheumatic heart disease, especially in those with pulmonary hypertension, compared with healthy patients.

Epidermal growth factor and glucocorticoid effects on blood prostaglandin E2 level in DENA-induced carcinogenesis.

This paper describes results on carcinogenesis in rats induced with diethylnitrosamine (DENA; 280 mg/kg single dose, i.p.). After inducing chemical carcinogenesis, the animals were treated with different compounds that affect cell proliferation and the effects on the blood prostaglandin E2 (PGE2) levels were observed. These compounds were epidermal growth factor (EGF, 10 micrograms/kg/24 h i.p., 7 days) and dexamethasone (4 mg/kg/24 h i.p., 7 days). The blood PGE2 levels of rats were measured by RIA (Radioimmunoassay). The blood PGE2 levels increased significantly following DENA and EGF administrations alone or together. Dexamethasone administration decreased the blood PGE2 levels. In conclusion the data show that the increase in the plasma PGE2 level by DENA treatment was enhanced by EGF but opposed by dexamethasone. This suggests that EGF may be effective as a promoter in chemical carcinogenesis.

Effects of EGF and allopurinol on prostaglandin and lipid peroxide levels in mucosa of stomach in restraint cold stress.

The cold and restraint gastric stress models were used in rats. Mucosal levels of prostaglandins, which have a protective effect on cells, and lipid peroxidation, a possible etiological factor in stress-induced gastric mucosal injuries, were investigated. Epidermal growth factor (EGF), which protects the gastric tissue from stress-induced lesions, and allopurinol, which inhibits xanthine oxidase, were given intraperitoneally. Both EGF and allopurinol decreased lipid peroxidation at the mucosal surface of the stomach. At the same time, allopurinol increased the serum gastrin levels and decreased the mucosal prostaglandin levels. It is concluded that EGF protects the gastric mucosal surface by way of increased tissue prostaglandin levels. EGF also decreased both serum gastrin and tissue malondialdehyde, an indicator of lipid peroxidation.

Effect of diethylnitrosamine on prostaglandin E and lipid peroxidation levels in rat's liver, lung and renal tissue.

We have investigated the generation of a prooxidant state and effect on prostaglandin E (PGE) levels after administration of diethylnitrosamine (DENA) to rats. Lipid peroxides were assayed by monitoring thiobarbituric acid (TBA) a reactive material. PGE--like activity was assayed by using bioassay procedure. Our results demonstrate that increased lipid peroxide and decreased PGE levels were found in a dose dependent manner in DENA injected groups when compared to control groups. According to these findings, it is suggested that there is a negative correlation between carcinogenic DENA induced lipid peroxidation and PGE in rat's liver, lung, and renal tissue.

Role of free oxygen radicals and prostanoids in the pathogenesis of Henoch-Schönlein Purpura.

The pathogenesis of Henoch-Schonlein Purpura (HSP) is still controversial. The aim of our study was to investigate the role of oxidative stress and cyclooxygenase (CO) pathway products in the pathogenesis of HSP. In order to investigate this, malondialdehyde (MDA) levels, indicating lipid peroxidation, prostaglandin E (PGE)-like activity as inflammatory mediator and vitamin E (vit-E) levels indicating anti-oxidant status were studied in a group of 10 children with HSP (five girls and five boys, aged 6-21 years, mean 10.7 years), both in the acute and recovery phase of the disease and in five age and sex-matched healthy children as a control group. The patients were also grouped into low and high clinical score groups. Plasma levels of MDA and PGE-like activity were significantly elevated in the active phase of HSP compared to the recovery phase. Vit-E levels were significantly reduced in the active phase compared to the recovery phase. The plasma levels of PGE-like activity of the patients obtained in the active phase were significantly higher than the levels of the control group, whereas the levels of the recovery phase were significantly lower than in the control group. No such difference between the controls and MDA and vit-E levels in the patient group was shown. No correlation between the clinical scores and the parameters studied could be found. Our findings indicate that oxidant stress and CO pathway products may play a role in the pathogenesis of HSP.

Biochemical alterations in neonatal hypoxic ischaemic brain damage.

Asphyxiated (n = 39) and control (n = 23) were elected for the study. Free radical-mediated lipid peroxidation, prostaglandin E2 and vitamin E levels were studied and the degree of hypoxic ischaemic encephalopathy was determined in each case. In the hypoxic group the concentration of prostaglandin E2 activity (P < 0.05) and malondialdehyde levels (P < 0.01) were significantly higher when compared to that of controls. The high vitamin E concentrations in the asphyxiated infants supports the role of oxygen free radicals in hypoxic ischaemic encephalopathy of newborns.

The serum nitric oxide levels in patients with Duchenne muscular dystrophy.

Nitric oxide is formed in skeletal muscle by the neuronal type nitric oxide synthase and the signalling function of dystrophin and related compounds are in part mediated by nitric oxide. Duchenne muscular dystrophy, mdx mice and patients with Becker dystrophy demonstrated neuronal type nitric oxide synthase deficiency in muscle biopsy specimens. We have intended to find out whether the plasma nitric oxide levels show any abnormality in patients with Duchenne muscular dystrophy. Serum NO levels of Duchenne patients (4.191+/-2.82 micromol/l) were significantly lower than those of the control (39.53+/-19.43 micromol/l) and cerebral palsy (77.84+/-21.70 micromol/l) groups.

Changes in blood haemorheological parameters after submaximal exercise in trained and untrained subjects.

The blood stream is affected by viscosity and many other haemorheological factors such as lipid peroxidation in the plasma and red blood cells. The aim of this study was to investigate the changes of haemorheological parameters after submaximal exercise in trained and untrained subjects. The results indicated that heart rate, lymphocyte count, erythrocyte deformability, plasma lipid peroxide levels and erythrocyte glutathione peroxidase activity are increased after submaximal exercise.

Effects of moderate altitude on exhaled nitric oxide, erythrocytes lipid peroxidation and superoxide dismutase levels.

The purpose of this study was to investigate the effects of staying at a moderate altitude (2,300 m, 7 d) on the levels of plasma nitrite, exhaled nitric oxide (NO), malondialdehyde (MDA) and superoxide dismutase (SOD). Measurements were obtained from 9 female (mean age 18.3 +/- 2) and 9 male (mean age 19.3 +/- 3.7) cross-country volunteer skiers: before, during (1st day, 7th day) and after staying at a moderate altitude. Exhaled nitric oxide levels were measured only before and after staying at the altitude. Nitrite levels increased throughout the stay at the altitude, while MDA levels decreased. In parallel with the nitrite levels, SOD activities were also found to have increased. Exhaled NO values were decreased after the stay at the moderate altitude. These results show that altitude hypoxia causes decreased in NO levels in the lung but increased systemic NO levels in the blood due to inhibition of erythrocyte lipid peroxidation.

The effect of melatonin on liver superoxide dismutase activity, serum nitrate and thyroid hormone levels.

Melatonin is a main neurohormone of the pineal gland. The effects of melatonin on the level of serum thyroid-stimulating hormone (TSH), thyroxine (T(4)), triiodothyronine (T(3)), nitrate, melatonin and liver superoxide dismutase (SOD) activity were examined in rats. Melatonin was injected at the dose of 10 mg/kg for 7 days, 2 h before turning the lights off. Rats were decapitated at 10:00 a.m. and 02:00 a.m., which are the times of the lowest and highest serum melatonin levels, respectively. Blood and tissue samples were collected. Decreased TSH, T(3), T(4) and nitrate levels were determined in the melatonin-injected and nighttime groups. Melatonin levels showed a diurnal rhythm. SOD activity increased in the melatonin-treated group. The results demonstrate that increased SOD activity, and reduced serum TSH, T(3), T(4) and nitrate levels correlated with the serum melatonin levels.

Effect of arthrocentesis and sodium hyaluronate injection on nitrite, nitrate, and thiobarbituric acid-reactive substance levels in the synovial fluid.

OBJECTIVE: To evaluate the effect of arthrocentesis and sodium hyaluronate (SH) injections on nitrite, nitrate, and thiobarbituric acid-reactive substance (TBA-RS) levels in temporomandibular joint internal derangements. STUDY DESIGN: Arthrocentesis was performed on 10 patients, and 15 patients received a supplemental injection of SH after arthrocentesis. All these patients received an SH injection 15 days after the first intervention. The synovial fluid samples were obtained before arthrocentesis on the first appointment and before the SH injection 15 days later. Nitrite and nitrate levels were measured with a highly sensitive and specific chemiluminescence detection method, and the concentration of lipid peroxidation products was assessed by means of the thiobarbituric acid reaction. RESULTS: Symptomatic improvement was seen in both groups. Nitrite, nitrate, and TBA-RS levels only decreased significantly (P <.05) with a supplemental SH injection after arthrocentesis. CONCLUSIONS: Intra-articular injections of SH may reduce nitrite, nitrate, and TBA-RS levels that play a role in the pathogenesis of various temporomandibular disorders.

Impact of stress, gender and menstrual cycle on immune system: possible role of nitric oxide.

Stress is a factor found to be involved in the etiology of many diseases. Gender and menstrual cycle phases are other factors affecting the predisposition of individuals for certain diseases. Results from animal and human studies suggest that the distribution of immune system cells may change at different phases of the menstrual cycle. Acute mental stress in humans alters immune variables, too. The increase in the number of natural killer (NK) cells is the most consistent finding among the immune variables, though there are controversies for the other lymphocyte groups. Nitric oxide (NO) as an immune mediator has an unsettled role whether it causes the redistribution of the immune cells, or is an end product of lymphocyte activation. This study was planned to investigate the effect of mental stress on lymphocyte subtypes and the role of NO, for men and women at different phases of the cycle. For this purpose, healthy men (n = 10) and women (n = 10), during the follicular and luteal phases underwent Stroop colour-word interference and cold pressor tests. The immune system responses before and after the tests were determined by cell counts with the flowcytometer. Menstrual cycle phase was ascertained by plasma estrogen and progesterone measurements. Stress response was evaluated by blood pressure (BP) and heart rate (HR) measurements throughout the tests and plasma cortisol and urinary metanephrine and vanillylmandelic acid (VMA) measurements before and after the tests. Plasma and urinary NO determinations were performed before and after the test was completed. All the results were analysed with the appropriate statistical methods. The luteal phase differed from the other groups due to the presence of suppressed immune response to acute stress, including decreased CD4/CD8 ratio and NK cell percentage. On the other hand, acute stress caused a shift from cellular to humoral immunity in men. As indicated by these results, individual reaction towards stress is affected by gender and menstrual cycle phase. NO appears to be a possible effector molecule for these differences.

The effect of epidermal growth factor on serum zinc levels.

Epidermal growth factor is a potent stimulator of the growth of epithelial and mesenchymal cells. In this study the effect of epidermal growth factor on the cells of developing mice intestine and on the serum zinc concentrations were assessed. Higher serum zinc concentrations (840.21 +/- 187.82 mg/dl) were found in the mice given epidermal growth factor (n: 10) as compared to the values obtained in the controls (347.55 +/- 108.88 mg/dl), (n: 12) (p less than 0.05).

Increased serum nitrite/nitrate (NOx) and malondialdehyde (MDA) levels during alcohol withdrawal in alcoholic patients.

Serum nitrite/nitrate (NOx) and malondialdehyde (MDA) levels of 40 male alcoholic patients and 14 healthy male controls were investigated. Severity of alcohol withdrawal in alcoholic patients was evaluated by using the Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar) scale just before taking the blood samples. NOx levels in serum samples were determined based on the reduction of nitrate to nitrite by vanadium chloride. MDA levels were also determined spectrophotometrically at 540 nm. The total CIWA-Ar score of alcohol-withdrawn patients was found to be 17.7. NOx and MDA levels were significantly increased in alcoholics during alcohol withdrawal as compared to control subjects. In conclusion, we observed increased serum NOx levels and lipid peroxidation during alcohol withdrawal in alcoholic patients.

Effects of protamine on nitric oxide level in the pulmonary circulation.

Protamine reversal of heparin anticoagulation often causes systemic hypotension by releasing nitric oxide (NO) from vascular endothelium. We investigated the hypothesis that protamine prevents severe pulmonary vasoconstriction by increasing NO. Twenty patients undergoing elective coronary artery bypass graft surgery were included in the study. Nitrite and nitrate levels--as end-metabolites of NO--were measured in blood samples obtained before and after protamine administration. Mean arterial pressure, heart rate, mean pulmonary artery pressure, central venous pressure and left atrial pressure were noted as hemodynamic data. Nitrite levels were 4.64 +/- 0.67 mumol in the right atrium and 4.84 +/- 0.95 mumol in the left atrium before protamine administration. The difference was insignificant statistically. These measurements were 4.85 +/- 0.92 in the right atrium and 5.28 +/- 0.66 mumol in the left atrium after protamine administration. This increase was significant (p < 0.05). The measurements of nitrate levels were completely parallel with those of nitrite. Mean arterial pressures were 78.9 +/- 7.59 mm-Hg before protamine and 74.1 +/- 8.55 mm-Hg after protamine (p = 0.03). The changes in other hemodynamic parameters were not significant. Protamine augments NO production and prevents the pulmonary circulation from possible vasoconstriction.

Intentional communicative behaviours of Turkish-speaking children with normal and delayed language development.

BACKGROUND: Language profiles may predict whether children with slower language development will catch up to their peers by overcoming this transient phenomenon or will be at risk for persistent language disorders. The research of the last decade has focused on this topic. Some researchers have emphasized the significance of developing communicative intentions, which provide a potential predictor of later language competence. In Turkey, children with slower language development may not be diagnosed partly because of the lack of sufficient standardized assessment/evaluation tools, educational and therapeutic media, and qualified speech-language therapists. In devising appropriate evaluation instruments, it is necessary to examine cross-linguistic variation in early language acquisition. The purpose of this study therefore is to observe, describe and assess early communicative behaviours of 15-36 months old Turkish-speaking children by using a functional communicative approach. METHODS: The research was designed within a qualitative-descriptive paradigm, involving qualitative data collection, observation and data analysis procedures. A total of 16 children, eight typically developing and eight language delayed, served as subjects. The classification system used in this study for coding children's communicative intentions was mostly based upon a system used by Dore (1977). Each variable was referred to as one of three intentional categories: regulating behaviours (request for object, request for action and protest), social interaction (direct attention, greeting and acknowledgement) and joint attention (comment/statement, asking for information and responding). A non-parametric Mann-Whitney U-test was carried out to verify the descriptive measures in comparing the delayed and normal group performance. RESULTS: As expected, the mode of expressing communicative intentions varied as a function of age for both groups. Children with normal language development were observed to express intentions within the category of joint attention more frequently whereas the children with delayed language expressed intentions related to the variables of regulating behaviours and social interaction.

Free radicals and antioxidant systems.

Free radicals are undesirable peroxides that have long been implicated in several deleterious effects in our body including aging process. They also play an important role in many physiological processes. For they are very reactive in nature, there are some anti-oxidant systems to scavenge or to quench them.