Comparative Analysis of Approaches to Regulation and Monitoring of Workers for Internal Radiation Exposure

Purpose: Harmonization and improvement of the system for regulating the internal radiation exposure of workers and the basic requirements for ensuring radiation safety with international requirements and recommendations. Material and methods: Issues related to the development of approaches to regulation and monitoring of workers for internal radiation exposure in the process of evolution of the ICRP recommendations and the national radiation safety standards, are considered. The subject of analysis is the standardized values: dose limits for workers and permissible levels as well as directly related methods of monitoring of workers for internal radiation exposure, whose purpose is to determine the degree of compliance with the principles of radiation safety and regulatory requirements, including non-exceeding the basic dose limits and permissible levels. The permissible levels of inhalation intake of insoluble compounds (dioxide) of plutonium-239 are considered as a numerical example. Results: Based on the analysis of approaches to the regulation and monitoring of workers for internal radiation exposure for the period from 1959 to 2019, it is shown that a qualitative change in the approach occurred in the 1990s. It was due to a decrease in the number of standardized values by introducing a single dose limit for all types of exposure: the effective dose E, which takes into account the different sensitivity of organs and tissues for stochastic radiation effects (WT), using the previously accepted concepts of the equivalent dose H and groups of critical organs. From the analysis it follows that the committed effective dose is a linear transformation of the intake, linking these two quantities by the dose coefficient, which does not depend on the time during which the intake occurred, and reflects certain exposure conditions of the radionuclide intake (intake routes, parameters of aerosols and type of radionuclide compounds). It was also shown that the reference value of the function z(t) linking the measured value of activity in an organ (tissue) or in excretion products with the committed effective dose for a reference person, which is introduced for the first time in the publications of the ICRP OIR 2015-2019, makes it possible to standardize the method of measuring the normalized value of the effective dose. Based on the comparison of the predicted values of the lung and daily urine excretion activities following constant chronic inhalation intake of insoluble plutonium compounds at a rate equal annual limit of intake (ALI) during the period of occupational activity 50 years it was shown that the modern biokinetic models give a slightly lower level (on average 2 times) of the lungs exposure compared to the models of the previous generation and a proportionally lower level (on average 1.4 times) of plutonium urine excretion for the standard type of insoluble plutonium compounds S. However, for the specially defined insoluble plutonium compound, PuO2, the level of plutonium urine excretion differs significantly downward (on average 11.5 times) compared to the models of the previous generation. Conclusion: With the practical implementation of new ICRP OIR models, in particular for PuO2 compounds, additional studies should be carried out on the behavior of insoluble industrial plutonium compounds in the human body. Besides, additional possibilities should be used to determine the intake of plutonium by measuring in the human body the radionuclide Am-241, which is the Pu-241 daughter. To determine the plutonium urine excretion, the most sensitive measurement techniques should be used, having a decision threshold about fractions of mBq in a daily urine for S-type compounds and an order of magnitude lower for PuO2 compounds. This may require the development and implementation in monitoring practice the plutonium-DTPA Biokinetic Model.

Sympathoadrenal activity and sleep: in the search for a marker of hyperarousal in insomnia

Objective. To assess subjective and objective sleep characteristics and urinary metanephrine levels in patients with insomnia. Design and methods. We included patients with insomnia complaints and those without sleep– related complaints (control group) 18–75 years old. Subjective evaluation of the main sleep characteristics during the last month was assessed by the Pittsburgh Sleep Quality questionnaire, daytime sleepiness — by the Epworth Sleepiness Scale. For objective sleep evaluation we performed one-night polysomnography (PSG). Within 1 week after the PSG, daily urine was collected to determine the level of metaepinephrine. Results. The groups did not differ by age, mean sleep duration over the past month, number of night awakenings by the Pittsburgh Questionnaire, and level of daytime sleepiness. Sleep latency in insomnia group was 15 minutes longer than in the control group. PSG showed higher apnea-hypopnea and desaturation indices in the control group. There were no differences in daily urinary metanephrine excretion in the main and control groups. Correlation analysis showed no significant association between the metanephrine levels and the severity of somnolence and the index of periodic limb movements. Conclusions. Our analysis showed no significant differences in the daily urine metanephrine levels and the main PSG sleep characteristics among subjects with and without insomnia. Further work is required to clarify markers of insomnia and their negative health effects.

Relationships of urolithogenicity index with some components of urine composition in healthy old female rats

Background. Despite the long history, the results of studies of the impact of balneotherapy in the resort of Truskavets on the lithogenicity of urine are ambiguous, so the topic remains relevant. The aim of this study was to determine the relationship between the lithogenicity index of urine and a number of components of its composition. Materials and Methods. Experiment was performed on 60 healthy old female Wistar rats 220-300 g. Ten animals remained intact, using daily water from drinking ad libitum. Other animals for 6 days were loaded through the tube with daily and various mineral waters at a dose of 1,5 mL/100 g of body mass. The day after the completion of the drinking course collected daily urine, which determined the content of a number of components of the composition. We calculated urine lithogenicity index (Lith) by the formula: Lith = (Uric acid•Calcium/Magnesium•Creatinine)0,25. Results. The most significant effect on the Lith is the concentration of magnesium (r=-0,730), followed by uric acid (r=0,583), calcium (r=0,352) and creatinine (r=-0,298). Medium molecular polypeptides, catalase, sodium, phosphates and urea has been identified as prolithogenic factors while tubular reabsorption of water as litholytic factor. The chemical composition of the fluids consumed by animals has little effect on the lithogenicity index of urine. Conclusion. Both prolithogenic and litholytic factors are present in the urine, which depend little on the chemical composition of the fluid used.

Peculiarities of neuroendocrine and metabolic effects of sulfate-chloride sodium-magnesium mineral waters "Myroslava" and "Khrystyna" of Truskavets’ spa in healthy female rats

Background. Earlier we found that the newly created sulfate-chloride sodium-magnesium drinking mineral waters of Truskavets’ spa have similar neuroendocrine and metabolic effects on healthy old female rats significantly different from daily water. The aim of this study is to elucidate the effects of these mineral waters on the neuroendocrine status and metabolism of these animals. Materials and Methods. Experiment was performed on 50 healthy female Wistar rats. Animals of the first group remained intact, using tap water from drinking ad libitum. Rats of the control group for 6 days injected a tap water through the tube at a dose of 1,5 mL/100 g of body mass. The rats of the main groups received the water "Myroslava" and "Khrystyna". The day after the completion of the drinking course in all rats, at first, assessed the state of autonomous regulation by parameters of the HRV. The plasma levels of the hormones of adaptation were determined: corticosterone, triiodothyronine and testosterone (by the ELISA) as well as electrolytes: calcium, magnesium, phosphates, chloride, sodium and potassium; nitric metabolites: creatinine, urea, uric acid, medium molecular polypeptides, bilirubin; lipid peroxidation products and antioxidant enzymes, as well as cholesterol, amylase and glucose. Most of the listed parameters of metabolism were also determined in daily urine. In the adrenals the thickness of glomerular, fascicular, reticular and medullar zones was measured. Results. To identify exactly those parameters, the set of which all four groups of animals differ significantly from each other, the information field of the registered parameters was subjected to discriminant analysis. The program included in the model 8 endocrine and 16 metabolic parameters, information about which is condensed into three roots. The first root reflects directly the SOD and corticosterone and inversely the reticular zone as well as plasma uric acid and glucose. The second root contains information about Nap/Kp ratio, natrihistia, amylasemia, magnesiumuria as well as inversely about kaliemia. The third root reflects directly the triiodothyronine, parathyroid activity, plasma Ca, natriuria and chloriduria as well as urine malondyaldehide. Inversely displays the root information about the testosterone, Ku/Nau ratio, glomerular zone, plasma katalase and Na as well as uricosuria and amylasuria. In the information space of the three discriminant roots, all four groups are quite clearly distinguished. Classification accuracy is 94% (three errors). Conclusion. The newly created sulfate-chloride sodium-magnesium drinking mineral waters of Truskavets resort have specific endocrine and metabolic effects on healthy old female rats with weekly use. This provides a basis for preclinical studies.

E-cigarette Smoking (Vaping) and Markers of Vascular Wall Damage in Young Subjects without Cardiovascular Disease

Aim: to investigate the effect of nicotine-containing vapes in comparison with traditional tobacco smoking on markers of vascular wall damage: high sensitivity C-reactive protein (hsCRP), albuminuria (AU), and ankle-brachial index (ABI).Material and Methods: We examined 369 young subjects without cardiovascular diseases (age median 21 [20;21] years) (159 men and 210 women). The hsCRP levels in the serum were assessed by immunochromatographic express method. AU was investigated in daily urine by a quantitative reflex photometry. ABI was determined by plethysmography.Results: All subjects were divided into groups: non-smokers (n=196, 53.1%), smokers of traditional cigarettes (n=83, 22.5%) and smokers of nicotine-containing vapes (n=90, 24.4%). The groups did not differ in main anthropometric data. Median hsCRP levels in smokers (14.30 [11; 16.5] mg/l in tobacco-smokers and 13.15 [9.65; 17.5] mg/l in vapers) were significantly higher vs nonsmokers (3.0 [2; 5.6] mg/l). In tobacco-smokers (33.0 [21.5; 60] mg) and vape smokers (45.0 [20; 115] mg), the median AU was statistically significantly higher than in non-smokers (12.0 [10; 20] mg). ABI levels were significantly lower in the groups of tobacco smokers (0.98 [0.91; 0.99]) and vapers (0.85 [0.79; 0.93]) when compared with nonsmokers (1.125 [1.01; 1.18]), and the median ABI in vapers was lower than in tobacco smokers (p<0.001). In the group of tobacco smokers, the hsCRP level correlated with the smoker's index (rs=0.31, p<0.05), and AU (rs=0.54, p<0.05) and ABI (rs=-0.28, p<0.05) with a daily inhaled nicotine dose. In the group of vapers, CRP was associated with smoking experience (rs=0.338, p<0.05), AU with a daily inhaled nicotine dose (rs=0.79, p<0.05), and ABI with BMI (rs=-0.33, p<0.05), heart rate (rs=-0.24, p<0.05) and smoking experience (rs=-0.235, p<0.05). According to the results of multivariate regression analysis the hsCRP level was related with only the smoking experience (B=0.91±0.19, p=0.000005), AU level with the daily inhaled nicotine dose (B=1.59±0.7, p=0.0121) and smoking experience (B=3.07±1.23, p=0.0179), and ABI level with only smoking experience (B=-0.09±0.004, p=0.0419).Conclusion: In smokers, both traditional and vapers, the levels of hsCRP, AU are significantly higher, and the ABI is lower than in healthy young nonsmokers. The most significant influence on the level of hsCRP is exerted by the experience of tobacco and vape smoking; to the AU level – the experience of tobacco and vaping and the daily inhaled nicotine dose, and by the value of the ABI – the experience of vaping.

A prospective study to compare the efficacy of noradrenaline verses terlipressin in hepatorenal syndrome in patients with advanced cirrhosis

Background: Hepatorenal syndrome (HRS) is functional renal failure occurring in advanced stage liver disease associated with poor prognosis. The best treatment is liver transplantation. Terlipressin is effective in treatment of HRS but noradrenaline has been suggested as cheaper and readily available alternative and we aimed to compare the efficacy of noradrenaline and terlipressin in patients with HRS.Methods: 30 patients were allocated to each group and group A received infusion of noradrenaline at dose of 0.5 mg/hr (maximum 3 mg/hr) and group B received terlipressin at dose 1 mg intravenously 6 hourly until reversal of HRS or completion of 7 days of therapy. Intravenous albumin (20 g/day) was given to both groups. Decrease in serum creatinine and increase in daily urine output and mean arterial pressure (MAP) helped us in comparison.Results: Out of 60 cirrhotics screened, 51 were randomised into group A (N=22) or group B (N=29). Baseline characteristics of both groups were similar. In group A, 0% showed complete response while 31.8% showed partial response but majority (68.2%) showed no response. In group B, 89.7% showed complete response and 6.9% showed partial response. Decrease in serum creatinine in both groups (group A- 3.91±1.58 mg/dl to 3.07±1.68 mg/dl; group B- 3.21±1.24 mg/dl to 1.36±0.87 mg/dl). Both groups showed an increase in MAP (group A- 76.93±6.18 mmHg to 89.49±6.93 mmHg; group B- 75.54±5.51 mmHg to 89.92±5.07 mmHg).Conclusions: Noradrenaline was not as effective as terlipressin in treatment of HRS.

Diuretic Resistance Treated with Low-Dose Hydralazine: A Case Report and Review of the Literature

We present a case of severe diuretic resistance and edema from acute cardiorenal syndrome complicating heart failure with preserved ejection fraction (HFpEF) and mild alcoholic liver disease. High doses of intravenous (iv) furosemide plus iv doses of chlorothiazide failed to increase the daily urine output (UV) above 1,500 mL or the fractional excretion of sodium (FE_Na) above 2%. The addition of a relatively low dose of hydralazine (10 mg thrice daily PO) during 5 days of constant iv infusion of furosemide plus iv bolus chlorothiazide doubled the UV and FE_Na while reducing the serum creatinine concentration from 3.3 to 2.0 mg/dL. Hydralazine may have restored a response to the diuretics by increasing the renal blood flow and thereby the renal diuretic delivery, or by reducing the filtration fraction or reducing the renal congestion and thereby reducing the proximal reabsorption during blockade of distal reabsorption with diuretics. Further mechanistic studies of low-dose hydralazine for diuretic resistance are warranted.

A case report of satisfactory post-left knee replacement pain control after switching from oxycodone to buprenorphine

This case report demonstrates using buprenorphine 32 mg to achieve adequate pain control after a total knee replacement. The patient stopped buprenorphine 48 hours before surgery. He was prescribed 150 tablets of oxycodone 5 mg. After finishing oxycodone, he experienced significant pain that was relieved by 32 mg of buprenorphine daily. Urine drug screens were negative perioperatively. Patients with opioid use disorder require careful discharge planning to avoid opioid relapses or misuses of pain medications. Buprenorphine offers many unique advantages in acute pain control, including lower risk of respiratory depression, abuse potential, and lower risk of nephrotoxicity.

Calcium-phosphorus relationships in the combined course of stable ischemic heart disease in patients with obesity

The purpose of the study was to optimize the diagnosis and prediction of the development of structural and functional disorders of bone tissue in patients with SCHD and obesity. Thus, lipid profile analysis showed a clinically significant increase in total cholesterol and triglycerides in patients with SCHD. Serum bone mineral status did not exceed normal values, but serum total calcium levels were significantly higher in patients with SCHD and obesity compared to other groups. The indicators of calcium-phosphorus metabolism in the daily urine of patients with SCHD were significantly higher. When conducting densitometric studies in patients with SCHD with normal weight, osteopenic conditions were diagnosed more often than in patients with overweight and obesity. That is, the comorbid course of SCHD and obesity is a high risk of osteodeficiency, which is confirmed by early changes in calcium-phosphorus metabolism.