Prevalence of Intestinal Parasitic Infections among the Bulgarian Population Over a Three Year Period (2015 - 2017).

The aim of the present study is to perform a retrospective analysis of the prevalence of intestinal parasitic infections among the Bulgarian population over the period 2015 - 2017. The study involved all Bulgarians and foreign nationals residing in the country who had been tested for intestinal protozoa and helminths. A total of 23,785 infections have been revealed, of which 17,712 (74.47 %) were helminth and 6,073 (25.53 %) protozoan invasions. Enterobiasis was found to be the most prevalent among patients infected with intestinal helminths (81.75 %), while giardiasis (62.05 %) was the most common among those diagnosed with protozoan infections. In spite of improved living conditions and increasing public health awareness, parasitic diseases in general, and intestinal parasitic infections in particular, still represent a significant part of the overall morbidity in Bulgaria, thus posing a major issue for the public health care system.

Patient dosimetry in paediatric diagnostic radiology.

A study of patient exposure in paediatric diagnostic radiology was conducted in three dedicated paediatric departments. The entrance surface dose was assessed by three methods: direct measurement by thermoluminescent dosemeters, calculation from the dose-area product and from the tube output. The results obtained by the these methods were compared, proving that all of them are applicable for the assessment of paediatric doses. Subsequently, the accumulated data were compared with the mean values from other similar studies and to the reference dose levels set by the Commission of European Communities, which clearly demonstrated the need for further investigation of the paediatric dose levels in Bulgaria and for optimisation of the radiological practice.

An estimate of the influence of the measurement procedure on patient and phantom doses in breast imaging.

This work is aimed to study the variability of dosimetry results owing to various measurement methodologies for breast dosimetry. This is performed in the frame of the development of a national protocol for breast dosimetry. Doses for standard phantom and group of patients were calculated for two mammography systems from the tube output measured with a calibrated ionisation chamber. The backscatter from the phantom under the chamber contributes to an increase in dosimeter readings of approximately 0.8-1.5%, whereas the proximity of the compression plate to the chamber causes increase in the measured air kerma value by 6.5-7%. High value layer (HVL) measured with solid-state detector without corrections for energy dependence was 17% higher than the one measured with ionisation chamber, which causes corresponding overestimation of average glandular dose (AGD). The use of conversion factors based on typical but not measured HVL values leads to 3.5-5.6% overestimation of AGD. Although the sources of uncertainty were taken into account, the difference between the phantom and patient doses was 24%. Some practical recommendations to be included in the national dosimetry protocol are summarised.

Patient dose in interventional radiology: a European survey.

Patient doses for a few common fluoroscopy-guided procedures in interventional radiology (IR) (excluding cardiology) were collected from a few radiological departments in 13 European countries. The major aim was to evaluate patient doses for the basis of the reference levels. In total, data for 20 procedures for about 1300 patients were collected. There were many-fold variations in the number of IR equipment and procedures per population, in the entrance dose rates, and in the patient dose data (total dose area product or DAP, fluoroscopy time and number of frames). There was no clear correlation between the total DAP and entrance dose rate, or between the total DAP and fluoroscopy time, indicating that a number of parameters affect the differences. Because of the limited number of patients, preliminary reference levels were proposed only for a few procedures. There is a need to improve the optimisation of IR procedures and their definitions and grouping, in order to account for their different complexities.

[Pathogenetic basis of the diagnosis and treatment of lymphedema of the lower extremities]. / Patogeneticheskie osnovy diagnostiki i lecheniia limfedemy nizhnikh konechnostei.

A combined clinico-morpho-physiologic investigation was conducted in 98 patients with primary and secondary lymphatic edema. All patients underwent lymphography by means of electron and light microscopy; biopsy specimens obtained from a lymphatic vessel at lymphography were investigated histologically, and contractility records were made. Pronounced disorders were demonstrated in the lymphatic vessels and their myocytes. New rational schedules of pathogenetic treatment for lymphedema of the lower limbs are outlined on the basis of the reported findings.

[Inhibition of spontaneous lymph vessel contraction evoked by transmural stimulation]. / Tormozhenie spontannykh sokrashchenii limfaticheskikh sosudov, vyzyvaemoe transmural'noi stimuliatsiei

In isolated sections of mesenteric lymphatic vessels, the constrictory responses to transmural electrical stimulation were studied. Inhibition of the spontaneous rhythm occurring primarily at low frequencies was revealed as well as the inhibition following the excitatory effect of high--frequency stimulation. Analysis of the transmural inhibition showed the latter to occur as the result of activation of adrenergic nervous plexus and to be fulfilled by the beta--adrenoreceptors.

[The contractile and electrical activity of the smooth muscles of the major lymph vessels]. / Sokratitel'naia i elektricheskaia aktivnost' gladkikh myshts magistral'nykh limfaticheskikh sosudov

In rats, catecholamines were found to increase the rate of the muscles spontaneous rhythmic contractions while the alpha- and beta-blocking agents suppressed them. The spontaneous contractions were blocked in the uncalunm medium. Rhythmic electrical stimulation evoked contracture-like responses the uncalunm of which depended on the strength, frequency, and duration of the stimulation. In spontaneoulsy active preparations, single electrical stimuli evoked contractions according to the "all or nothing" rule. The membrane potential magnitude varied within the limits of 25-37 mV, and action potentials were related to the contractions. The data obtained suggest that the functional unit of conduction of spontaneous or evoked excitation waves is represented by a group of smooth muscle cells within a single lymphangion.

[The theory of lymphangion and current approaches to the pathogenesis, diagnosis and treatment of lymphedema of the lower extremities]. / Teoriia limfangiona i sovremennye podkhody k patogenezu, diagnostike i lecheniiu limfedemy nizhnikh konechnostei.

The paper describes the results of examination carried out by the Sankt-Peterburg school of lymphologists, pertaining to the structure, physiological properties and function of lymphangions responsible for active lymph transport. The problems of the pathogenesis, diagnosis and treatment of lymphedema of the lower extremities used in clinical practice are reviewed from the standpoint of the new theory. The data obtained as a result of the clinico-morphofunctional studies allowed to delineate the stages of lymphedema as dependent on the degree of lymphocytic structure and function integrity. Based on the aforesaid the new approaches to the diagnosis and selection of the treatment methods for lymphedema of the lower extremities have been formulated.