Semi-automatic quantification of mosaic perfusion of lung parenchyma and its correlation with haemodynamic parameters in patients with chronic thromboembolic pulmonary hypertension.

AIM: To investigate the feasibility of semiautomatic quantification of mosaic perfusion and the associations between mosaic perfusion on computed tomography (CT; the ratio of hypoperfused parenchyma to the whole lung volume) and haemodynamic parameters through linear regression analysis. MATERIALS AND METHODS: Fifty-eight consecutive patients (mean age 66 years, 28 females) diagnosed with chronic thromboembolic pulmonary hypertension (CTEPH) in General University Hospital, Prague, in 2021 were evaluated retrospectively and underwent both right heart catheterisation and CT pulmonary angiography. The parameters derived from the CT examinations were correlated with the recorded haemodynamic parameters. RESULTS: A method was developed for semiautomatic detection of hypoperfused tissue from CT using widely available software and a statistically significant correlation was found between the proportion of hypoperfused parenchyma and the mean pulmonary artery pressure (mPAP; R2 0.22; p<0.01) and pulmonary vascular resistance (PVR; R2 0.09; p<0.05). CONCLUSIONS: The developed method facilitates the quantification of mosaic perfusion, which is associated with important haemodynamic parameters (mPAP and PVR) in patients with CTEPH.

A word on the microbiome: considerations about the history, current state, and terminology of an emerging discipline.

Since the beginning of the 21st century, a new discipline, microbiome science, has emerged as a key part of microbiology and related biomedical and ecological sciences. Microbiome science uses highly advanced molecular genetic and bioinformatic methods to study complex microbial communities. Unlike isolated microbes, microbial communities shaped by the environment, referred to as microbial consortia or microbiomes, follow their own laws that allow for significant functional specialization. The synthesis of multimethodology and multidisciplinary data enables microbiome science to move towards a holistic picture of the microbiome in an exceptionally effective way, but on the other hand, it burdens the field with terminological ambiguity of the key terms, which consequently need to be clearly codified in accordance with the international trends in the use of technical nomenclature. To this end, we present in our article the official position of the Czech Microbiome Society of the J. E. Purkyne Czech Medical Society on the use of appropriate Czech terms in both professional and general communication.

Search for Lepton Number and Flavor Violation in K

Searches for the lepton number violating K^{+}→π^{-}µ^{+}e^{+} decay and the lepton flavor violating K^{+}→π^{+}µ^{-}e^{+} and π^{0}→µ^{-}e^{+} decays are reported using data collected by the NA62 experiment at CERN in 2017-2018. No evidence for these decays is found and upper limits of the branching ratios are obtained at 90% confidence level: B(K^{+}→π^{-}µ^{+}e^{+})<4.2×10^{-11}, B(K^{+}→π^{+}µ^{-}e^{+})<6.6×10^{-11} and B(π^{0}→µ^{-}e^{+})<3.2×10^{-10}. These results improve by 1 order of magnitude over previous results for these decay modes.

Midazolam and dexmedetomidine sedation impair systolic heart function.

BACKGROUND: Sedation is an essential part of clinical practice. Despite this fact, we still lack data describing the exact impact of sedation on heart function. PURPOSE: To compare the changes in heart function, induced after sedation with either midazolam or dexmedetomidine, using cardiac magnetic resonance imaging (MRI). METHODS: A total number of 30 volunteers were randomized into two groups: 15 participants in the midazolam group (MID) and 15 participants in the dexmedetomidine group (DEX). Every participant underwent a one-session cardiac MRI before and after sedation onset. The following parameters were recorded: left and right ventricle stroke volume (Ao-vol and Pul-vol resp.) and maximum flow velocity through the mitral valve during early (E-diast) and late diastole (L-diast). A monitor recorded values of mean blood pressure (MAP), pulse (P) and blood oxygen saturation (SpO2) in 5-minute intervals. RESULTS: Dexmedetomidine led to a statistically significant decrease in Ao-vol (p = 0.006) and Pul-vol (p = 0.003), while midazolam decreased E-diast (p = 0.019) Ao-vol (p = 0.001) and Pul-vol (p = 0.01). The late diastolic filling was not influenced by the sedation technique. CONCLUSION: Both sedation regimens worsened the systolic function of both ventricles. Midazolam moreover attenuated early diastolic filling of the left ventricle (Tab. 3, Fig. 4, Ref. 19).

Rectal cancer - current treatment strategy and the tumor regression grade evaluation after neoadjuvant therapy in patients who underwent surgery at the I. Department of Surgery, General University Hospital in Prague between 2012 and 2016.

INTRODUCTION: The article contains a summary of the issues of staging and therapy with an emphasis on the neoadjuvant treatment and associated tumor regression grade with the analysis of our own group of patients. METHODS: Retrospective analysis of patients with rectal cancer who underwent a surgery at the 1st Department of Surgery - Thoratic, Abdominal and Injury Surgery; First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic, focusing on those who underwent neoadjuvant chemoradiotherapy and their pathologists evaluated tumor regression grade after the resection. RESULTS: The group consists of 161 patients operated on between 2012 and 2016. 47 patients underwent neoadjuvant oncological treatment with further evaluation of the tumor regression grade by a pathologist, a scoring system according to Ryan was used. A complete pathological response was elicited in 10.4% of patients, no response in 35.4% of patients, and partial tumor regression in 54.2%. CONCLUSION: Although there is a difference in our results compared to foreign publications, the proportion of patients remains comparable. Studies evaluating the advantages versus disadvantages of neoadjuvant therapy will certainly follow, and the question of the suitability of surgical treatment as the only curative solution is partially raised.

Treatment of anastomotic leak after Ivor Lewis esophagectomy.

INTRODUCTION: Anastomotic leak (AL) is one of the most serious surgical complications after esophagectomy. Endoscopic, radiological and surgical methods are used in the treatment of AL. The aim of this study was to retrospectively evaluate our therapeutic procedures and results of AL treatment after Ivor Lewis esophagectomy (ILE). METHODS: Retrospective audit of all ILEs performed in the years 20052019. Evaluation of AL treatment results according to Esophagectomy Complication Consensus Group (ECCG) classification and according to the primary therapeutic procedure with a focus on the treatment with esophageal stent. RESULTS: Out of 817 patients with ILE, AL was detected in 80 patients (9.8%): ECCG type I 33 (41%), type II 23 (29%) and type III 24 (30%) patients. Some 33 patients (41%) were treated conservatively. Esophageal stents were used in 39 patients (49%), of which 18 (23%) had concomitant percutaneous drainage and 17 (21%) were reoperated. Reoperation without a stent insertion was performed in 7 patients (9%). Esophageal diversion with cervical esophagostomy was performed in a total of 16 patients (20%). Esophageal stent treatment was successful in 24/39 patients (62%). Airway fistula occurred in 4 patients treated with stent (10%). Endoscopic vacuum therapy was successfully used in three patients after stent failure. Eight patients (10%) died as a result of AL. Mortality of AL type I, II and III was 0%, 4% and 29%. CONCLUSION: Successful treatment of AL requires an individual and multidisciplinary approach. The primary effort should aim to preserve anastomosis using endoscopic and radiological methods. In case of insufficient clinical effect, we recommend not to hesitate with reoperation. If primary therapy fails, the life-saving procedure is a cervical esophagostomy.

Evaluation of iris functional capillary density in experimental local and systemic inflammation.

The ocular microcirculation represents an important target to treat inflammatory diseases of eye, where impairment of microvascular blood flow plays key role as, for example, in anterior uveitis. To evaluate novel interventions targeting the microcirculation, appropriate and reliable tools to study this particular microvascular bed are needed. Intravital microscopy (IVM) belongs to several methods allowing evaluation of microcirculation experimentally, even in small animals. The aim of our study was to examine the iridial microcirculation (IMIC) in uveitis induced by local or systemic endotoxin administration in rats and mice by IVM and to propose new parameters to quantify the changes within the IMIC. Systemic inflammation was induced in rats by intravenous endotoxin administration, control group received normal saline intravenously. Local inflammation was induced in mice by intravitreal endotoxin administration, the control group received normal saline intravitreally. IVM of IMIC was performed in animals receiving systemic endotoxin prior injection and 1 and 2 h afterwards, respectively, in animals receiving intravitreal endotoxin/saline prior local injection and 5 h afterwards. Obtained video recordings were analyzed off-line. Functional capillary density (FCD) and dysfunctional capillary density (DCD) were evaluated for description of IMIC, and calculation of FCD/DCD ratio was performed. In systemic inflammation, FCD was significantly decreased compared to control animals. In local inflammation, the number of functional capillaries in the IMIC was significantly reduced following the endotoxin challenge. Analysis of the DCD revealed a significant increase in capillaries with reduced perfusion after intravitreal endotoxin administration and right shift of the FCD/DCD ratio was observed after endotoxin local injection. Detecting and quantifying changes in IMIC during systemic or local inflammation in experimental animals by IVM was feasible. Therefore, IVM of the IMIC represents a valuable tool to evaluate and quantify inflammatory changes in experimental eye disease.

Utility of cardiac CT for evaluating delayed contrast enhancement in dilated cardiomyopathy.

BACKGROUND: The presence of myocardial fibrosis is associated with adverse outcome in dilated cardiomyopathy (DCM). Delayed contrast-enhanced cardiac magnetic resonance (DE-CMR) currently represents the gold standard in noninvasive evaluation of myocardial scarring. However, a significant number of patients are unable to undergo DE-CMR study for various reasons. We sought to determine the diagnostic accuracy of cardiac CT (CCT) compared with CMR in the investigation of the presence of delayed contrast enhancement (DCE) in subjects with DCM. METHODS: We prospectively enrolled 17 consecutive patients with DCM, who were initially referred to our institution because of recently manifested heart failure due to unexplained left ventricular systolic dysfunction. In all subjects, CCT and DE-CMR were performed within 1 week. RESULTS: CCT and DE-CMR showed satisfactory agreement in detecting DCE (agreement in 82% cases, κ = 0.56) with 50% sensitivity, 100% specificity, and a positive predictive value of 100%. CONCLUSION: CCT may be a valuable method for detecting DCE in patients with DCM. CCT thus might be considered as an alternative method to DE-CMR in the assessment of the presence and extent of myocardial fibrosis in subjects who are not suitable for DE-CMR examination.

In situ assessment of the renal microcirculation in mechanically ventilated rats using sidestream dark-field imaging.

For microcirculation research there is a need for baseline data and feasibility protocols describing microcirculation of various organs. The aim of our study was to examine the reliability and reproducibility of sidestream dark-field (SDF) imaging within the renal cortical microcirculation in rats. Renal microcirculation was observed using SDF probe placed on the exposed renal surface via the upper midline laparotomy. Video sequences recorded intermittently in short apneic pauses were analyzed off-line by using AVA 3.0 software (MicroVision Medical, Amsterdam, the Netherlands). Results are expressed as mean (SD) or median (25-75% percentiles). We obtained 60 clear sequences from all recorded analyzable videos from all the animals. The total small vessel and all vessel density (in mm.mm(-2) ) were (28.79 ± 0.40) and (28.95 ± 0.40), respectively. The perfused small and all vessel density were (28.79 ± 0.40) and (28.95 ± 0.40), respectively. The DeBacker Score was (19.14 ± 0.43), the proportion of perfused vessels was 100% (100-100%) and the microvascular flow index was 3.49 (3-3.75). We conclude SDF imaging provides a reliable method to examine the renal microvascular bed in vivo and thus can be used for the study of the renal cortical vascular network in various experimental diseases models and clinical settings.

Noninvasive assessment of the iridial microcirculation in rats using sidestream dark field imaging.

Sidestream dark field imaging represents a novel, noninvasive method to study the microcirculation in humans and animals. To-date, it has been used extensively in various peripheral tissues (e.g. sublingual area, intestinal mucosa), however no data for the ocular vasculature, including the iridial microcirculation, are currently available. Therefore, the aim of this study was to examine the reliability and reproducibility of sidestream dark field imaging within the iridial microcirculation in experimental animals. Male Lewis rats were anaesthetized and the iris microvasculature was observed using an sidestream dark field probe gently placed against a cover slip covering the right eye. All video sequences recorded were analysed off-line by using AVA 3.0 software (MicroVision Medical, Amsterdam, The Netherlands). Results are expressed as mean (±SE) or median (interquartile range). Clear images were recorded from each animal and the total number of analysable video sequences was 50. All raw data for selected vessel density parameters passed normality test. The total all and small vessel density (in mm mm(-2) ) were 22,6 (±0,58) and 19,6 (±0,68), respectively. The perfused all and small vessel density were 20,9 (±0,61) and 19,1 (±0,65), respectively. The mean values of all iris vessel density parameters are shown in Figure 4. The DeBacker Score (n/mm) was 15,2 (±0,45), the proportion of perfused vessel was 94,5% (89,8-99,1%), and the MFI was 3 points (3-3). Taken together, these results indicate that SDF imaging provides a reliable and noninvasive method to examine the iridial microvascular bed in vivo and, thus, may provide unique opportunities for the study of the iridial vascular network in various experimental and clinical settings and disease models.

Intra-arrest formation of right-heart thrombi -- a case illustrated by real-time ultrasonography.

The presence of free-floating right-heart thrombus has been reported in a cardiac arrest patient in the periarrest period. Free-floating right atrial thrombus is a rare phenomenon seen in patients developing severe pulmonary embolism, and is associated with increased mortality. However, there have been no previously reported cases of right-heart thrombus formation during a resuscitated cardiac arrest. We present the pre-hospital case of a woman in the clinical setting of cardiogenic shock due to acute myocardial infarction who developed asystolic cardiac arrest on the scene. Recent implementation of ultrasonography into the regional pre-hospital care protocol enabled sonographic investigation before and during cardiac arrest. This allowed detection of right atrial septal thrombus formation in the course of advanced life support and its migration through the tricuspid valve. The pathophysiological consequences, clinical significance and potential therapeutic options are discussed.

[Serious sepsis treatment in intensive care departments in the Czech Republic -  EPOSS Project pilot results]. / Lécba tezké sepse na pracovistích intenzivní péce v Ceské republice -  pilotní výsledky projektu EPOSS.

INTRODUCTION: Severe sepsis is still associated with significant morbidity and mortality, which is however different, as well as its management, depending on the region. What is the situation in the Czech Republic and what is the character of patients with severe sepsis is currently not known. The aim of the project is to describe the processes of care, outcome and characteristics of patients with severe sepsis admitted to the intensive care department of the Czech Republic. METHODS: This is a multicentre and observational project with retrospective enrollment of patients who meet the criteria for severe sepsis before or within 24 hours after admission to selected intensive care units (ICU EPOSS). RESULTS: 394 patients were analyzed. Median age at admission was 66 (56- 76) years, males predominated (58.9%) and the median APACHE II score on admission was 25 (19- 32). Patients were predominantly medical (56.9%) and most were secondary admitted from other ICU (53.6%). Meeting the criteria of severe sepsis was most frequently within the period (± 4 hours) of admission the EPOSS ICU (77.6%). Median total fluid intake during the first 24 hours was 6,680 (4,840- 9,450) ml. Most patients required mechanical ventilation (58.4%). Compliance with the resuscitation bundle of severe sepsis in our group was very good and was associated with lower mortality of patients. Most frequently, the EPOSS ICU length of stay (LOS) was 7 (3- 15) days and median hospital LOS was 13 (8- 28) days. Hospital mortality in our cohort was 35.8%. CONCLUSION: Introducing the project, which in its first stage obtained valuable and internationally comparable data about patients with severe sepsis admitted to the involved ICU in the Czech Republic.

[Peripartal life-threatening hemorrhage - interdisciplinary consensus opinion]. / Peripartální zivot ohrozující krvácení - mezioborové konsenzuální stanovisko.

22 experts from the fields of gynecology and obstetrics, anesthesiology and resuscitation, intensive care, hematology and transfusion medicine has developed recommendations for diagnosis and procedure for life-threatening peripartum haemorrhage, which is still one of the most common causes of maternal mortality in childbirth. This guidelines, which is valid for the Czech Republic, supported by a total of 10 professional medical societies. There are based on new knowledge applicable at this time and is focused mainly on eliminating the most common causes of bleeding during delivery and prevention of haemorrhagic shock.

[Recombinant activated factor VII in the treatment of life threatening post-partum haemorrhage; registry UniSeven in the Czech Republic]. / Rekombinantní aktivovaný faktor VII (rFVIIa) v lécbe závazného poporodního krvácení data z registru UniSeven v Ceské republice.

OBJECTIVE: To analyze the data related to the treatment of 80 Czech patients with life threatening postpartum haemorrhage recorded in the clinical registry UniSeven during years 2004-2009. DESIGN: Retrospective, observational, multicentre study. SETTINGS: ICU and Obstetrics departments of University and Regional hospitals in Czech Republic. MATERIAL AND METHODS: UniSeven is an international academic project of Masaryk University in Brno, Czech Republic, focused on recording of clinical data related to "off-label" use of rFVIIa (Novo Seven) in life threatening bleeding. Data of 80 case reports of post partum haemorrhage from the registry was analysed from the clinical (efficacy and safety) as well as laboratory aspects. RESULTS: In 97.5% of our patients the treatment with rFVIIa was able to control the bleeding. In 53 women (66.3%) only one dose of rFVIIa was sufficient to control the bleeding. The rest of the patient received two or more rFVIIa doses. First dose of rFVIIa given to patients who needed more than one dose was significantly lower (96.6 microg/kg) compared to patient succesfully treated with one dose only (110.6 microg/kg; p = 0.048). The mortality rate in our cohort of patients was 2.5%. We have not recorded any thrombembolic event as and adverse event related to the rFVIIa treatment. In 74.3% of patients where rFVIIa was administered before considering the hysterectomy, it was able to avoid hysterectomy what we consider to be a significant improvement of the patients' quality of life. CONCLUSIONS: Our data were also considered during the work up of national guidelines for the treatment of life threatening post-partum haemorrhage in the Czech Republic.

In situ assessment of the liver microcirculation in mechanically ventilated rats using sidestream dark-field imaging.

Assessment of hepatic microcirculation by on-line visualization has been impossible for a long time. Sidestream dark-field (SDF) imaging is a relatively new method allowing direct visualization of both mucosal microcirculation and surface layers microcirculation of solid organs using hand-held probe for direct contact with target tissue. The aim of this study was to evaluate the feasibility of studying the rat hepatic microcirculation in situ by SDF imaging. The liver lobes were left in situ, and images were obtained using SDF imaging on the surface of the liver via upper midline laparotomy. Images were captured intermittently during 10-sec apnoea and recorded. The microvascular parameters were compared with previous validation studies. Clear high contrast SDF images were successfully obtained. Quantitative analysis revealed a mean FSD (functional sinusoidal density) of 402+/-15 cm/cm(2), a sinusoidal diameter of 10.2+/-0.5 microm and postsinusoidal venular diameter of 33.9+/-13 microm. SDF imaging is a suitable noninvasive method for accurate quantification of the basic microcirculatory parameters of the liver in situ without a need to exteriorize the liver lobes. This method seems to be applicable in animal studies with possibility to use SDF imaging also intraoperatively, providing unique opportunity to study liver microcirculation during various experimental and clinical settings.

[Current cooling methods for induction of mild hypothermia in cardiac arrest survivors]. / Soucasné ochlazovací metody pro indukci mírné hypotermie po srdecní zástave.

Induction of mild therapeutic hypothermia early after return of spontaneous circulation improves prognosis of cardiac arrest survivors. Rapid cooling of the patients and correct maintainance of the target therapeutic temperature followed by controlled slow rewarming can be achieved by several noninvasive and invasive methods of various efficacy. Elementary and the most frequently used methods are surface cooling via ice-packs and rapid intravenous administration of cold crystaloids. Mattress cooling systems and facilities for endovascular cathether-cooling are more sophisticated, manageable and ensure more precise titration of therapeutic temperature. Cooling caps and helmets leading to selective head cooling can be used as the complementary techniques. Several other methods are too instrumentation-intensive, too invasive or investigated in animal experiments only. Anyway, near future may bring a rapid development of new effective and safe cooling systems.

Noninvasive in vivo assessment of the skeletal muscle and small intestine serous surface microcirculation in rat: sidestream dark-field (SDF) imaging.

The pathophysiology of microcirculation is intensively investigated to understand disease development at the microscopic level. Orthogonal polarization spectral (OPS) imaging and its successor sidestream dark-field (SDF) imaging are relatively new noninvasive optical techniques allowing direct visualization of microcirculation in both clinical and experimental studies. The goal of this experimental study was to describe basic microcirculatory parameters of skeletal muscle and ileal serous surface microcirculation in the rat using SDF imaging and to standardize the technical aspects of the protocol. Interindividual variability in functional capillary density (FCD) and small vessels (<25 microm in diameter) proportion was determined in anesthetized rats on the surface of quadriceps femoris (m. rectus femoris and m. vastus medialis) and serous surface of ileum. Special custom made flexible arm was used to fix the SDF probe minimizing the pressure movement artifacts. Clear high contrast images were analyzed off-line. The mean FCD obtained from the surface of skeletal muscle and ileal serous surface was 219 (213-225 cm/cm(2)) and 290 (282-298 cm/cm(2)) respectively. There was no statistically significant difference between rats in mean values of FCD obtained from the muscle (P = 0.273) in contrast to ileal serous surface, where such difference was statistically significant (P = 0.036). No statistically significant differences in small vessels percentage was detected on either the muscle surface (P = 0.739) or on ileal serous surface (P = 0.659). Our study has shown that interindividual variability of basic microcirculatory parameters in rat skeletal muscle and ileum is acceptable when using SDF imaging technique according to a highly standardized protocol and with appropriate fixation device. SDF imaging represents promising technology for experimental and clinical studies.

The role of embolization in radical surgery of renal cell carcinoma spinal metastases.

BACKGROUND: Radical surgery of renal cell carcinoma spinal metastases carries a high risk due to potentially life-threatening extreme blood loss. Radical preoperative embolization of renal cell carcinoma metastases alone is not necessarily a guarantee of extreme blood loss not occurring during operation. METHODS: A retrospective analysis of 15 patients following radical surgery for a spinal metastases of a renal cell carcinoma was performed. Eight patients were embolized preoperatively and 7 were not. We analysed features influencing peroperative blood loss: size and extent of tumour, complexity of surgical approaches and radicality of embolization. RESULTS: The embolized and non embolized groups were not comparable before treatment. They differed markedly in size of tumour as well as the complexity of approach. In the embolized group the size of the tumour was, on average, twice as large as that in non embolized patients and more complex approaches were used twice as frequently. Despite findings suggesting that embolization was effective, blood loss was greater in the embolized group of 8 patients (4750 ml), compared to the non-embolized group of 7 patients (1786 ml). CONCLUSION: Metastasis size, extent of tumour, technical complexity of surgery and the completeness of preoperative embolization had an important effect on the amount of peroperative blood loss. The evaluation of the benefits of preoperative embolization only on the basis of blood loss is not an adequate method.

Genetic history of the African Sahelian populations.

From a biogeographic perspective, Africa is subdivided into distinct horizontal belts. Human populations living along the Sahel/Savannah belt south of the Sahara desert have often been overshadowed by extensive studies focusing on other African populations such as hunter-gatherers or Bantu in particular. However, the Sahel together with the Savannah bordering it in the south is a challenging region where people had and still have to cope with harsh climatic conditions and show resilient behaviours. Besides exponentially growing urban populations, several local groups leading various lifestyles and speaking languages belonging to three main linguistic families still live in rural localities across that region today. Thanks to several years of consistent population sampling throughout this area, the genetic history of the African Sahelian populations has been largely reconstructed and a deeper knowledge has been acquired regarding their adaptation to peculiar environments and/or subsistence modes. Distinct exposures to pathogens-in particular, malaria-likely contributed to their genetic differentiation for HLA genes. In addition, although food-producing strategies spread within the Sahel/Savannah belt relatively recently, during the last five millennia according to recent archaeological and archaeobotanical studies, remarkable amounts of genetic differences are also observed between sedentary farmers and more mobile pastoralists at multiple neutral and selected loci, reflecting both demographic effects and genetic adaptations to distinct cultural traits, such as dietary habits.