Dependence of inertial cavitation induced by high intensity focused ultrasound on transducer <i>F</i>-number and nonlinear waveform distortion.

Pulsed high intensity focused ultrasound was shown to enhance chemotherapeutic drug uptake in tumor tissue through inertial cavitation, which is commonly assumed to require peak rarefactional pressures to exceed a certain threshold. However, recent studies have indicated that inertial cavitation activity also correlates with the presence of shocks at the focus. The shock front amplitude and corresponding peak negative pressure (p -) in the focal waveform are primarily determined by the transducer F-number: less focused transducers produce shocks at lower p -. Here, the dependence of inertial cavitation activity on the transducer F-number was investigated in agarose gel by monitoring broadband noise emissions with a coaxial passive cavitation detector (PCD) during pulsed exposures (pulse duration 1 ms, pulse repetition frequency 1 Hz) with p- varying within 1-15 MPa. Three 1.5 MHz transducers with the same aperture, but different focal distances (F-numbers 0.77, 1.02, 1.52) were used. PCD signals were processed to extract cavitation probability, persistence, and mean noise level. At the same p -, all metrics indicated enhanced cavitation activity at higher F-numbers; specifically, cavitation probability reached 100% when shocks formed at the focus. These results provide further evidence supporting the excitation of inertial cavitation at reduced p - by waveforms with nonlinear distortion and shocks

RUSSIAN MEDICAL EDUCATION FROM INTERNATIONAL STUDENTS’ VIEW POINT: CHALLENGES AND COPING STRATEGIES

Purpose. The manuscript is devoted to the burning issue of education internationalization in modern society. Having come to study in Russia, many international students face a number of difficulties concerning various aspects of their life activity. The authors aim to study international students’ opinion regarding their residence in the European North and their study at the Russian medical university. Methodology. Survey findings of 149 Indian students studying at the International Faculty of General Practitioners of the Northern State Medical University (NSMU), Arkhangelsk compose the research basis. Results. Main challenges encountered by international students in the conditions of the European North, their attitude to the organization and quality of the educational process in the university were revealed. Cold climate, language barrier, the lack of traditional foods and separation from family are believed to be the main factors that make it difficult for junior students to learn. Senior students express their disappointment at the lack of clinical practice due to the distance learning during the pandemic and different level of students and teachers’ language proficiency. In general, students speak positively about university educational process and are satisfied with Russian education quality. Practical implications. Research findings can be used to develop recommendations for improving the socio-pedagogical adaptation of international students in Russian universities

Comparison of methods of physical examination of the bronchopulmonary system offered by the russian school of propaedeutics and foreign medical universities

The aim of the study - to evaluate the usefulness from the point of view of students, as well as the clinical significance of physical diagnostic methods structured in training videos "methods of examination of a patient with a pathology of the respiratory system", offered by the national school of propaedeutics, and videos used by foreign universities.Цель исследования - оценить, полезность с точки зрения обучающихся, а также клиническую значимость физикальных методов диагностики, структурированных в обучающие видео «методика обследования пациента спатологией респираторной системы», предлагаемых отечественной школой пропедевтики, и видео, использующихся зарубежными вузам

p-Adic Mathematical Physics

A brief review of some selected topics in p-adic mathematical physics is presented.Comment: 36 page

Left Ventricle Non-Compaction Myocardium and Thrombophilia in a Pregnant Woman

Non-compaction of the ventricular myocardium (NCM) is a genetic cardiomyopathy usually due to mutationof the G4.5 gene located in the Xq28 chromosomal region. This congenital disorder is characterized by pronounced trabeculations and intertrabecular recesses resulting from abnormal embryogenesis between the fifth and eighth fetal weeks. The reported prevalence in the general population is between 0.014% and 1.3%. The classic triad of complications includes heart failure, ventricular arrhythmias and systemic embolic events, although some patients have an asymptomatic form. NCM is commonly diagnosed by echocardiography, but contrast ventriculography, CT and MRI can also be used. Here we present a case of left ventricle NCM, manifested after respiratory infection, in a pregnant patient with congenital thrombophilia and a history of myocardial infarction

Междисциплинарный интегративный подход к ведению беременности при доброкачественных и пограничных опухолях яичника: клинический случай и обзор литературы

The management and treatment of patients with various malignancies during pregnancy appears to be a pressing issue to date. Ovarian tumors take the 4th place among all neoplasms diagnosed during pregnancy. The study aimed to investigate an interdisciplinary integrative approach to pregnancy management in case of benign and borderline ovarian tumors.The article presents the analysis of the pregnancy course in women with borderline and malignant ovarian tumors. When detecting a tumor during pregnancy, obstetric and surgical tactics is determined in a multidisciplinary team together with an oncologist.It is possible not only to prolong pregnancy without additional chemotherapy but also to preserve fertility in the future in patients with borderline tumors and stage I malignant tumors.Ведение и лечение пациенток с онкологическими заболеваниями на фоне беременности сегодня представляется очень актуальной проблемой. Среди всех онкологических заболеваний, выявляемых при беременности, опухоли яичников занимают 4 место. Цель исследования — изучить междисциплинарный интегративный подход к ведению беременности при доброкачественных и пограничных опухолях яичника.В статье представлены данные по анализу течения беременности у женщин с пограничными и злокачественными опухолями яичников.При обнаружении опухолей во время беременности акушерская и хирургическая тактика определяются индивидуально совместно с онкологом.При пограничных опухолях, а также злокачественных опухолях Iа стадии возможно не только пролонгирование данной беременности без дополнительного химиотерапевтического лечения, но и сохранение фертильности в дальнейшем

Do Fleas Affect Energy Expenditure of Their Free-Living Hosts?

Parasites can cause energetically costly behavioural and immunological responses which potentially can reduce host fitness. However, although most laboratory studies indicate that the metabolic rate of the host increases with parasite infestation, this has never been shown in free-living host populations. In fact, studies thus far have shown no effect of parasitism on field metabolic rate (FMR).We tested the effect of parasites on the energy expenditure of a host by measuring FMR using doubly-labelled water in free-living Baluchistan gerbils (Gerbillus nanus) infested by naturally occurring fleas during winter, spring and summer. We showed for the first time that FMR of free-living G. nanus was significantly and positively correlated with parasite load in spring when parasite load was highest; this relationship approached significance in summer when parasite load was lowest but was insignificant in winter. Among seasons, winter FMRs were highest and summer FMRs were lowest in G. nanus.The lack of parasite effect on FMR in winter could be related to the fact that FMR rates were highest among seasons. In this season, thermoregulatory costs are high which may indicate that less energy could be allocated to defend against parasites or to compensate for other costly activities. The question about the cost of parasitism in nature is now one of the major themes in ecological physiology. Our study supports the hypothesis that parasites can elevate FMR of their hosts, at least under certain conditions. However, the effect is complex and factors such as season and parasite load are involved

Ультразвуковое исследование при планировании операций по поводу меланомы кожи конечностей

We performed a retrospective analysis of ultrasound scans in 42 patients with cutaneous melanoma of the extremities in planning the closure of skin defects with skin fascial island flaps supplied by perforating vessels. First, the primary melanoma focus was scanned by ultrasound to reveal characteristics of the skin, tumor and adjacent tissues. Then we detected perforating vessels to mark them and to select the sites for the island flaps. Ultrasound examination was performed using the IU 22 PHILIPS, GE Logiq E9 and Supersonic imagine AIxPLORER MultiWave Systems with linear multi-frequency sensors (517 MHz) in the B-mode, color and power Doppler to visualize the blood flow. We clarified the criteria of the necessary and sufficient parameters according to Doppler ultrasound visualization for surgical treatment of cutaneous melanoma of the extremities by the suggested method in preoperative period, as well as monitoring of the flap state after surgery. The transfer of flaps on perforating vessels did not cause blood flow disorders in them: the mean arterial blood flow velocity was 13.1 ± 4.7 cm/sec before surgery and 12.8 ± 5.4 cm/sec after it. The maximal venous flow velocity was on average 7.0 ± 1.3 cm/sec before surgery and 6.2 ± 0.8 cm/sec after it. Thus, triplex ultrasound significantly facilitates the selection and individual design of the flap with the inclusion of feeding vessels of sufficient potential, helps in planning the operation, reduces the risk of failure and improves the results of treatment. This method contributes to the radicalization of surgical intervention with a simultaneous decrease in the risk of postoperative complications and acceleration of medical and social rehabilitation of patients.Проведен ретроспективный анализ ультразвуковых исследований у 42 больных меланомой кожи конечностей при планировании закрытия кожного дефекта островковыми кожно-фасциальными лоскутами на перфорантных сосудах. Вначале выполнялось УЗИ первичного очага меланомы для уточнения характеристик кожи, опухоли, прилежащих тканей. Затем осуществлялся поиск перфорантных сосудов для их маркировки и определения расположения островковых лоскутов. УЗИ выполнены на экспертных аппаратах «IU 22 PHILIPS», GE «Logiq E9», «Supersonic imagine AIxPLORER multi Wave» линейными мультичастотными датчиками (5–17 мГц) в В-режиме, цветовом и энергетическом картировании кровотока. Уточнены критерии необходимых и достаточных параметров по результатам сонодопплерографической визуализации для хирургического лечения меланомы кожи конечностей по предлагаемому способу в предоперационном периоде и мониторинг состояния лоскутов после операции. Было установлено, что перемещение лоскутов на перфорантных сосудах не приводило к нарушениям кровотока в них: до операции средняя скорость артериального кровотока составила 13,1±4,7 см/с, после операции – 12,8±5,4 см/с. Максимальная венозная скорость до операции в среднем была 7,0±1,3 см/с, после операции – 6,2±0,8 см/с. Таким образом, триплексное сканирование значительно облегчает выбор и индивидуальный дизайн лоскута с включением в него питающих сосудов достаточного потенциала, существенно помогает в планировании операции, снижет риск неудач и способствует улучшению результатов лечения. Данный метод способствует повышению радикальности хирургического вмешательства с одновременным снижением риска послеоперационных осложнений, ускорением медицинской и социальной реабилитации больных

Type 1 Diabetes Impairs Cardiomyocyte Contractility in the Left and Right Ventricular Free Walls but Preserves It in the Interventricular Septum

Type 1 diabetes (T1D) leads to ischemic heart disease and diabetic cardiomyopathy. We tested the hypothesis that T1D differently affects the contractile function of the left and right ventricular free walls (LV, RV) and the interventricular septum (IS) using a rat model of alloxan-induced T1D. Single-myocyte mechanics and cytosolic Ca2+ concentration transients were studied on cardiomyocytes (CM) from LV, RV, and IS in the absence and presence of mechanical load. In addition, we analyzed the phosphorylation level of sarcomeric proteins and the characteristics of the actin-myosin interaction. T1D similarly affected the characteristics of actin-myosin interaction in all studied regions, decreasing the sliding velocity of native thin filaments over myosin in an in vitro motility assay and its Ca2+ sensitivity. A decrease in the thin-filament velocity was associated with increased expression of β-myosin heavy-chain isoform. However, changes in the mechanical function of single ventricular CM induced by T1D were different. T1D depressed the contractility of CM from LV and RV; it decreased the auxotonic tension amplitude and the slope of the active tension-length relationship. Nevertheless, the contractile function of CM from IS was principally preserved. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This work was supported by the Russian Science Foundation № 18-74-10059. The work was performed using the equipment of the Shared Research Center of Scientific Equipment of Institute of Immunology and Physiology

The mechanisms of antibiotic resistance in major pathogens of purulent-inflammatory complications in cancer patients

The problem of microbial antibiotic resistance and investigation of its underlying mechanisms is of paramount importance for all fields of clinical medicine, including oncology. The aim of the study was to examine the mechanisms of antibiotic resistance for major pathogens causing purulent-inflammatory complications in cancer patients. Materials and methods. In 2012—2015 there was conducted a prospective examination of 184 cancer patients, including 67 patients at the Department of Surgery no. 1 and 117 patients at the Intensive Care Unit of the Krasnoyarsk Regional Clinical Oncology Center named after A.I. Kryzhanovsky. For this, we collected bronchoalveolar lavage fluid, wound discharge and investigated the material by using bacteriological method, as well as MALDI-TOF. Antibiotic sensitivity was studied as follows: disco-diffusion, double disc method, carbapenem inactivation method, staphylococcal sensitivity — by screening method, PCR, E-test method, and serial dilutions in Muller-Hinton broth. Genotyping and antibiotic resistance mechanisms study were performed by using PCR, M-PCR, and sequencing. The WHONET program (WHO) was used, with significance level set at p &lt; 0.05. Results. Microbiological examination of bronchoalveolar lavage fluid and wound discharge samples allowed to uncover prevalent associations of multi-resistant (MDR) and extremely resistant pathogens (XDR). The microflora of the lower respiratory tract and in the wound secretion in cancer patients were found to be dominated by non-fermenting Gram-negative bacteria reaching up to 44.5% and 48%, respectively; as well as order Enterobacteriales found in 24% and 34.9%, respectively; Gram-positive bacteria — 24% and 17.1%, respectively. Imipenem- and/or meropenem-resistant P. aeruginosa and A. baumannii, K. pneumoniae strains, were assessed for MBL production phenotypically, as well as the genes of the most common VIM, IMP types, whereas A. baumannii — for OXA-23, OXA-40, and OXA-58; and K. pneumoniae — for OXA-48. 20 strains and 16 strains of P. aeruginosa and A. baumannii, respectively, were studied by PCR. It was found that A. baumannii strains formed no MBL, but 56.3% of A. baumannii isolates (9 strains) produced OXA-23 and OXA-40 carbapenemases. Among P. aeruginosa strains there were three of them which possessed VIM (15.0%), whereas the remaining strains formed no MBL, but were resistant to carbapenems being associated with other resistance mechanisms, e.g. efflux, decreased permeability of cell wall etc. Among 6 isolates of K. pneumoniae, 1 strain produced OXA-48. In cancer patients, the percentage of methicillin-resistant strains among all members of the genus Staphylococcus was 48.9% (4 strains belonged to MRSA). PVL- MRSA strains belonged to the clones ST239/spa3(t037)/SCCmecIIIA/tst,sek,seq+ (75%) and ST8/ spa1(t008)/SCCmecIVc/sea+ (25%). MRSA ST239 showed multiple antibiotic resistance: to aminoglycosides (aacA-aphD, aadD genes were detected), linkcosamides/macrolides (the ermA gene was detected), fluoroquinolones (mutations in the GyrA gene — Ser84Leu; in GrlA- Ser80Phe), rifampicin (MIC more than 128 gg/ml; mutations in the rpoB gene are His481Asn, Ile527Met), sulfamethoxazole, tetracycline (tetM gene), and chloramphenicol (66.7% of isolates, the cat gene encoding chloramphenicol acetyl transferase was detected); but sensitive to vancomycin (MIC 1.0 gg/ ml), linezolid in 100% of cases. MRSA ST8 are resistant to aminoglycosides (aacA-aphD, aadD genes), lincosamides/macrolides (ermC gene), tetracyclines (tetK gene), chloramphenicol (cat gene); and 100% sensitive to fluoroquinolones, rifampicin (MIC 0.006 gg/ml), sulfamethaxazole, vancomycin (MIC 1.0 gg/ml), daptomycin (MIC 0.094 gg/ml), linezolid (MIC 0.75 gg/ml). Conclusion. Thus, it was found that members of the order Enterobacteriales, A. baumannii, P. aeruginosa and MRSA retain high resistance to a large number of antibacterial drugs of almost all classes. These data should be taken into account while choosing proper antibiotic therapy, as well as controlling spread of nosocomial infections caused by multiresistant microorganisms