ABSTRACT
In human-altered landscapes, specialist butterflies typically form spatially restricted populations, genetically differentiated due to dispersal restrictions. Generalists, in contrast, display minimum differentiation but high genetic diversity. While local-level actions suffice to conserve specialists and landscape-level actions are necessary for generalists, minimum information exists regarding conservation of species with intermediate features. We targeted two congeneric butterflies, the recently re-expanding Argynnis adippe and the strongly declining A. niobe, co-occurring in the pastoral landscape of the Carpathian Mountains, Czech Republic. We integrated species distribution models, mark-recapture and microsatellite analysis to compare their habitat requirements, adult demography, dispersal and genetic patterns, and expanded the genetic analysis across the Carpathian Arc and beyond to delimit spatial conservation units. In two mountain valleys, both species formed interconnected populations numbering thousands of individuals. Mobility patterns suggested the populations' interconnection across the Czech Carpathians. Genetic diversity was extremely poor in the nonthreatened A. adippe and moderate in the declining A. niobe. No population differentiation was detected within the Czech Carpathians (~1500 km2 ). Low genetic diversity and no differentiation was preserved in A. adippe across East Central Europe, whereas in A. niobe, populations from Serbia were differentiated from the Carpathian Arc + Alps. The high adult mobility linked to low differentiation probably reflects the distribution of larval resources, historically widespread but sparse and currently declining for A. niobe (grazing-disturbed grounds), while currently increasing for A. adippe (abandonment scrub, disturbed woodlands). Units as large as entire mountain systems define population boundaries, and hence conservation management units, for both species.
Subject(s)
Butterflies , Animals , Humans , Butterflies/genetics , Genetics, Population , Europe , Ecosystem , DemographyABSTRACT
Healthcare data held by state-run organisations is a valuable intangible asset for society. Its use should be a priority for its administrators and the state. A completely paternalistic approach by administrators and the state is undesirable, however much it aims to protect the privacy rights of persons registered in databases. In line with European policies and the global trend, these measures should not outweigh the social benefit that arises from the analysis of these data if the technical possibilities exist to sufficiently protect the privacy rights of individuals. Czech society is having an intense discussion on the topic, but according to the authors, it is insufficiently based on facts and lacks clearly articulated opinions of the expert public. The aim of this article is to fill these gaps. Data anonymization techniques provide a solution to protect individuals' privacy rights while preserving the scientific value of the data. The risk of identifying individuals in anonymised data sets is scalable and can be minimised depending on the type and content of the data and its use by the specific applicant. Finding the optimal form and scope of deidentified data requires competence and knowledge on the part of both the applicant and the administrator. It is in the interest of the applicant, the administrator, as well as the protected persons in the databases that both parties show willingness and have the ability and expertise to communicate during the application and its processing.
Subject(s)
Confidentiality , Data Anonymization , Humans , PrivacyABSTRACT
INTRODUCTION: Chloramphenicol is an antibiotic with a broad spectrum of action and excellent tissue penetration. It had been widely used in clinical practice until the 1970s, but due to its potential myelotoxicity, it was gradually replaced by newly introduced antibiotics in the following years. The aim of the study was to find out to what extent and with what experience it is currently used in the Czech Republic. METHODS: A questionnaire survey was conducted in July and August 2022. The heads of all inpatient infectious diseases departments, hospital infectious diseases specialists and consulting microbiologists from antibiotic centers in large teaching hospitals without an infectious diseases department were asked to fill out the questionnaire. RESULTS: Thirty-five out of 39 hospitals contacted took part in the study, a response rate of 90 %. Chloramphenicol is used in 37 % of participating hospitals, with a frequency of up to 10 patients treated per year. The most common indications are brain abscesses, purulent meningitis, intra-abdominal, pelvic and lung abscesses, and polymicrobial infections with anaerobes. Chloramphenicol is almost always administered as an alternative antibiotic because of polyvalent allergy, bacterial resistance, and failure of previous treatment. Sixty-six percent of respondents described the effect as reliable or partially reliable, 34 % did not rate the effect. Fifty-two percent of respondents considered a dose of 8-9 g to be the maximum dose for an adult patient. In practice, 60 % of respondents did not encounter or could not assess the myelotoxic effects of chloramphenicol, 37 % observed reversible bone marrow suppression at least once, and only one respondent encountered aplastic anemia once. CONCLUSION: Unfortunately, chloramphenicol is currently used in less than half of hospitals in the Czech Republic. Because of its unique properties, it still has a place in today's anti-infective treatment. When properly indicated and after weighing the benefits and risks, it can be a suitable and sometimes life-saving alternative.
Subject(s)
Anti-Infective Agents , Bacterial Infections , Communicable Diseases , Adult , Humans , Chloramphenicol/adverse effects , Anti-Bacterial Agents/adverse effects , Bacterial Infections/drug therapy , Anti-Infective Agents/therapeutic useABSTRACT
The updated Czech guidelines differ in some aspects from the 2021 guidelines issued by the ESCMID Study Group for Clostridium difficile. The key points of these Czech recommendations may be summarized as follows: ⢠The drug of choice for hospitalized patients is orally administered fidaxomicin or vancomycin. In outpatients with a mild first episode of C. difficile infection, metronidazole can also be used. ⢠If the patient's response to treatment is good and there are no complications, the duration of antibiotic treatment can be reduced (e.g. to 5 days in case of fidaxomicin or to 6-7 days in case of vancomycin). ⢠If oral therapy is impossible, the drug of choice is tigecycline, 100 mg i.v., b.i.d., with initial shortening of the interval between the first and second doses for faster saturation. If the severity of the disease progresses during this antibiotic treatment, it is necessary to access the ileum or cecum, i.e. to perform double ileostomy or percutaneous endoscopic cecostomy, and to instill vancomycin or fidaxomicin lavages. ⢠Fulminant C. difficile colitis should be treated with oral fidaxomicin ± tigecycline i.v. If peristalsis ceases, fidaxomicin should be administered into the ileum or cecum as described above. If sepsis develops, a broad-spectrum beta-lactam antibiotic (piperacillin/tazobactam, carbapenem) i.v. is added to topically administered fidaxomicin instead of tigecycline i.v.; at the same time, colectomy should be considered as the last resort. ⢠To treat first recurrence, fidaxomicin or vancomycin is administered with a subsequent fecal microbiota transplant (FMT) from a healthy donor. For second or subsequent recurrence, administration of fidaxomicin is of little benefit; the therapy of choice is oral vancomycin and subsequent FMT. Prolonged vancomycin or fidaxomicin taper and pulse treatment is appropriate only when FMT cannot be performed.
Subject(s)
Clostridioides difficile , Clostridium Infections , Colitis , Humans , Vancomycin/therapeutic use , Fidaxomicin/therapeutic use , Clostridioides , Tigecycline/therapeutic use , Czech Republic , Aminoglycosides/adverse effects , Clostridium Infections/drug therapy , Anti-Bacterial Agents/therapeutic use , Colitis/chemically induced , Colitis/drug therapyABSTRACT
OBJECTIVES: The aim of the study was to obtain data on demands on the intensive care capacities to treat COVID-19 patients, and to identify predictors for in-hospital mortality. METHODS: The prospective observational multicentre study carried out from 1 March till 30 June 2020 included adult patients with confirmed SARS-CoV-2 infection with respiratory failure requiring ventilatory support or high-flow nasal oxygen therapy (HFNO). RESULTS: Seventy-four patients, 46 males and 28 females, median age 67.5 (Q1-Q3: 56-75) years, were included. Sixty-four patients (86.5%) had comorbidity. Sixty-six patients (89.2%) were mechanically ventilated, four of them received extracorporeal membrane oxygenation therapy. Eight patients (10.8%) were treated with non-invasive ventilation and HFNO only. The median of intensive care unit (ICU) stay was 22.5 days. Eighteen patients (24.3%) needed continuous renal replacement therapy. Thirty patients (40.5%) died. Age and acute kidney injury were identified as independent predictors of in-hospital death, and chronic kidney disease showed trend towards statistical significance for poor outcome. CONCLUSIONS: Sufficient number of intensive care beds, organ support equipment and well-trained staff is a decisive factor in managing the COVID-19 epidemic. The study focused on the needs of intensive care in the COVID-19 patients. Advanced age and acute kidney injury were identified as independent predictors for in-hospital mortality. When compared to clinical course and ICU management of patients with severe community-acquired pneumonia caused by other pathogens, we observed prolonged need for ventilatory support, high rate of progression to acute respiratory distress syndrome and significant mortality in studied population.
Subject(s)
COVID-19 , Adult , Aged , Critical Care , Female , Hospital Mortality , Humans , Male , Prospective Studies , SARS-CoV-2ABSTRACT
The guidelines provide evidence-based recommendations for the management of COVID-19. The clinical manifestations of the disease are described and indication criteria for hospital admission of patients with COVID-19 are listed. Polymerase chain reaction and antigen testing are used in direct diagnostics. Indirect detection of infection by antibodies is currently of limited value. There are a number of hematological and biochemical laboratory test used to diagnose COVID-19. Pathological values of some laboratory parameters are associated with severity of COVID-19. Of the imaging studies, chest X-ray, chest computer tomography and lung ultrasound are used. COVID-19 therapy includes symptomatic and specific therapy (antivirals, immunotherapeutics and anticoagulants) and intensive care in the severe and critical forms of the disease. Remdesivir and favipiravir are available as antiviral agents. Immunotherapeutics include monoclonal antibodies (casirivimab/imdevimab, bamlanivimab/etesevimab), dexamethas one, baricitinib and tocilizumab. Low-molecular-weight heparin is a dominant form of anticoagulant therapy. The guidelines provide specific therapeutic recommendations for each stage of the disease. Antibiotics are recommended only if bacterial superinfection is suspected or demonstrated, which is not common in the early stages of the disease.
Subject(s)
COVID-19 , Antiviral Agents/therapeutic use , Humans , Lung/diagnostic imaging , SARS-CoV-2 , UltrasonographyABSTRACT
Photosensitive compounds found in herbs have been reported in recent years as having a variety of interesting medicinal and biological activities. In this review, we focus on photosensitizers such as hypericin and its model compounds emodin, quinizarin, and danthron, which have antiviral, antifungal, antineoplastic, and antitumor effects. They can be utilized as potential agents in photodynamic therapy, especially in photodynamic therapy (PDT) for cancer. We aimed to give a comprehensive summary of the physical and chemical properties of these interesting molecules, emphasizing their mechanism of action in relation to their different interactions with biomacromolecules, specifically with DNA.
Subject(s)
Anthraquinones/chemistry , Antineoplastic Agents/pharmacology , Neoplasms/drug therapy , Perylene/analogs & derivatives , Photosensitizing Agents/pharmacology , Animals , Anthracenes , Antineoplastic Agents/chemistry , Humans , Perylene/chemistry , Perylene/pharmacology , Photochemotherapy , Photosensitizing Agents/chemistryABSTRACT
The article summarizes the known facts regarding the selection of antibiotics for the treatment of sepsis and similar serious infections, their mechanism of action, dosage and mode of administration. Particular attention is paid to early antibiotic therapy: a delay of several hours in the onset of antibiotic therapy can be tolerated if it helps to clarify the aethiology and to refine the treatment. However, in case of the very acute infections it is necessary to start antibiotic treatment immediately; diagnostic procedures are mentioned that can be used for the selection of the appropriate drug.
Subject(s)
Bacterial Infections , Sepsis , Anti-Bacterial Agents , Bacterial Infections/drug therapy , Humans , Sepsis/drug therapyABSTRACT
The microbial etiology and source of sepsis influence the inflammatory response. Therefore, the plasma levels of cytokines (IL-6, IL-8, and IL-10), chemokines (CCL2/MCP-1, MIP-1ß), heparin-binding protein (HBP), soluble CD14 (sCD14), and cortisol were analyzed in blood from septic patients obtained during the first 96 hours of intensive care unit hospitalization. The etiology was established in 56 out of a total of 62 patients enrolled in the study. Plasma concentrations of MCP-1, sCD14, IL-6, and IL-10 were significantly higher in patients with community-acquired pneumonia (CAP; n = 10) and infective endocarditis (IE; n = 11) compared to those with bacterial meningitis (BM; n = 18). Next, cortisol levels were higher in IE patients than in those with BM and CAP, and at one time point, cortisol was also higher in patients with gram-negative sepsis when compared to those with gram-positive infections. Furthermore, cortisol and MCP-1 levels correlated positively with the daily measured SOFA score. In addition, HBP levels were significantly higher in patients with IE than in those with BM. Our findings suggest that MCP-1, sCD14, IL-6, IL-10, cortisol, and HBP are modulated by the source of sepsis and that elevated MCP-1 and cortisol plasma levels are associated with sepsis-induced organ dysfunction.
Subject(s)
Biomarkers/metabolism , Sepsis/metabolism , Aged , Antimicrobial Cationic Peptides/metabolism , Blood Proteins/metabolism , Carrier Proteins/metabolism , Chemokine CCL2/metabolism , Chemokine CCL4/metabolism , Critical Care , Female , Humans , Hydrocortisone/metabolism , Interleukin-10/metabolism , Interleukin-6/metabolism , Interleukin-8/metabolism , Lipopolysaccharide Receptors/metabolism , Male , Middle AgedABSTRACT
We present a case of a 17-year-old female with anti-NMDAR encephalitis probably associated with vaccination against yellow fever. Her symptoms occurred 27 days after vaccination against yellow fever. Anti-NMDAR encephalitis manifested as acute psychosis, memory loss and catatonia following fever with complex partial epileptic seizures. Interictal electroencephalogram showed slow-wave delta background activity with "delta brushes". The diagnosis was confirmed by NMDAR antibody positivity in serum and cerebrospinal fluid. Since ovarian teratoma, as the most common cause of anti-NMDAR encephalitis, did not develop within five years from its onset, the association with vaccination against yellow fever seems to be highly probable.
Subject(s)
Anti-N-Methyl-D-Aspartate Receptor Encephalitis/complications , Clostridioides difficile/isolation & purification , Clostridium Infections/therapy , Fecal Microbiota Transplantation , Yellow Fever Vaccine/adverse effects , Yellow Fever Vaccine/immunology , Adolescent , Female , HumansABSTRACT
Sepsis was understood as a disease caused by an invasive bacterial infection associated with deluging of organism with bacterial toxins (blood poisoning). Schottmüllers definition emphasized the existence of a focus as the source of invading bacteria. Further research led to the discovery of the cytokine cascade and to the recognition that sepsis is induced by our own endogenous mediators. The dysfunction or failure of various organs in sepsis can be explained both by hemodynamic disorders which originate in the altered microcapillars but also by a complex transformation of metabolism. To explain metabolic changes, the theory of tissue hibernation was postulated. According to the alternative theory, metabolic changes arise due to attenuation of mitochondrial function, which develops as part of a complex antibacterial response. Definitions of sepsis from the mid-19th century to the present are described.Key words: pathogenesis of sepsis - sepsis - sepsis definition - septic shock.
Subject(s)
Sepsis/physiopathology , Hemodynamics/physiology , Humans , Multiple Organ Failure/physiopathologySubject(s)
Coronavirus Infections/mortality , Coronavirus Infections/prevention & control , Health Policy , Pandemics/prevention & control , Pneumonia, Viral/mortality , Pneumonia, Viral/prevention & control , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/diagnosis , Czech Republic/epidemiology , Europe , Humans , Masks , Pneumonia, Viral/diagnosis , Protective Factors , Public Health Surveillance/methods , Quarantine , SARS-CoV-2ABSTRACT
PURPOSE: The objective of this survey was to determine the incidence of Clostridium difficile infections (CDI) at the Department of Infectious Diseases, Bulovka Hospital, and to evaluate clinical and epidemiological data on CDI patients together with a detailed molecular characterisation of C. difficile isolates. The patient outcomes were correlated to causative C. difficile PCR-ribotype. METHODS: The twelve-month study (2013) comprised patients two years of age and older with CDI. CDI severity was estimated using ESCMID criteria and ATLAS scoring. C. difficile isolates were further characterized using ribotyping, Multiple-Locus Variable Tandem-Repeats analysis (MLVA) and investigation of antibiotic-resistance determinants (gyrA, gyrB, rpoB, ermB). RESULTS: A total of 619 diarrhoeal stools were investigated. Seventy-two stool samples were GDH and toxin A/B positive, and 39 samples were GDH positive only and subsequently toxigenic C. difficile was cultured. In total, 111 C. difficile isolates were characterized, of which 64 (57.7%) belonged to PCR-ribotype 176. MLVA analysis of PCR-ribotype 176 isolates revealed 11 clonal complexes. Seventy-two isolates (64.9%) showed amino acid substitution Thr82Ile in the GyrA, and sixty-two isolates (55.9%) showed amino acid substitutions Arg505Lys together with His502Asn, or Asp492Glu together with Arg505Lys in the RpoB. Twelve isolates (10.8%) were ermB positive. Severe CDI according to the ESCMID criteria was recorded in forty-two patients (37.8%), and sixteen patients (14.4%) had ATLAS score ≥ 6. Twenty-nine patients (26.1%) had recurrent CDI and twenty-four patients (21.6%) died during the study period. CONCLUSIONS: A higher rate of severe CDI, recurrences and mortality in association with PCR-ribotype 176 infections were observed. The high incidence of PCR-ribotype 176 in the study, and the presence of clonal relatedness between PCR-ribotype 176 isolates, indicate its higher capacity to spread in a hospital setting, which in turn highlights the need to implement strict epidemic measures when PCR-ribotype 176 occurs.
Subject(s)
Bacterial Proteins/genetics , Clostridioides difficile/classification , Cross Infection/diagnosis , Diarrhea/diagnosis , Enterocolitis, Pseudomembranous/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Child , Child, Preschool , Clostridioides difficile/drug effects , Clostridioides difficile/genetics , Clostridioides difficile/isolation & purification , Cross Infection/drug therapy , Cross Infection/mortality , Cross Infection/pathology , Diarrhea/drug therapy , Diarrhea/mortality , Diarrhea/pathology , Drug Resistance, Bacterial/genetics , Enterocolitis, Pseudomembranous/drug therapy , Enterocolitis, Pseudomembranous/mortality , Enterocolitis, Pseudomembranous/pathology , Female , Gene Expression , Humans , Male , Middle Aged , Multilocus Sequence Typing , Mutation , Retrospective Studies , Ribotyping , Severity of Illness Index , Survival Analysis , Treatment OutcomeABSTRACT
This article gives information on selected alternative medicine methods (AMM) under conditions of the Czech health care system. They can be defined as contemporaneous diagnostic and therapeutic methods which differ in their theoretical fundaments as well as practices from the evidence based medicine. This definition is controversial because these methods are an intrinsically incompatible aggregate of modalities acting as a placebo above all. We can encounter many "therapeutic" and "examination" methods which are practiced namely by healers without formal medical education, and connected closely with esotericism. A general feature of the alternative methods is a void usage of scientific concepts and theories, e.g. the concept of energy.Motivations of patients and doctors are briefly introduced here. However, AMM is also an ethical problem because the doctor should help the patient with maximum efficiency hence excluding the methods with a questionable, small or negligible efficiency. The opinions how to find the way out from this situation are divergent. It could be a refusal or a very reserved attitude to AMM plus maximisation of the placebo effect enhancing the efficiency of a rational therapy. Furthermore, the methods most spread in the Czech Republic are subjected to elementary critics - the homoeopathy, acupuncture, the so-called "bioresonance" instrumental methods, psychic healing, and also some refused methods in cancer treatment. In our opinion medicine disposes of sufficient knowledge and experience to assess the efficiency of AMM and refuse them in causal therapy, eventually. Their use as a placebo should be carefully considered.Key words: alternative medicine, placebo, homeopathy, acupuncture.
Subject(s)
Complementary Therapies/methods , Czech Republic , HumansABSTRACT
OBJECTIVES: Problems with importing non-registered medicines for treating rare life-threatening infectious diseases led to establishment of the Emergency Anti-Infective Drug Reserve (EAIDR) for the Czech Republic. METHODS: Thirteen anti-infective drugs are included in the project: antisera against rabies virus, varicella-zoster virus, and botulinum toxin; antituberculosis drugs (intravenous rifampicin and isoniazid; capreomycin, cycloserine, and clofazimine); antiparasitics (intravenous quinine, primaquine, meglumine antimoniate, and praziquantel); and pentamidine. These drugs are imported according to the Czech drug legislation (specific drug availability programs). Realization: The project, approved by the Czech Ministry of Health in September 2013, was started in January 2014. The anti-infective drugs sufficient for 2-4 patients are permanently available in the Toxicological Information Center (TIC) in Prague. The medicines can be applied in any hospital throughout the Czech Republic within several hours. CONCLUSIONS: All but three drugs are available at present; the remaining ones will be imported after new batches of these drugs are released.
Subject(s)
Anti-Infective Agents/supply & distribution , Emergencies , National Health Programs , Czech Republic , HumansABSTRACT
Clostridium difficile infection (CDI) is a disease of varying severity. Its manifestations range from mild diarrhea to life-threatening paralytic ileus, painful distension of the large bowel, and sepsis. Another possible manifestation of the disease is recurring colitis that can exhaust the patient. For establishing the diagnosis, the patient's stool should be examined with two or three different microbiological methods (testing for clostridial toxins A and B; testing for clostridial glutamate dehydrogenase, anaerobic culture with specific media, or PCR detection of genes for production of clostridial toxins). An alternative way of assessing the etiology is colonoscopic examination; the disease is confirmed if characteristic patchy pseudomembranes are present in the bowel mucosa. Optimal treatment depends on severity of the disease and on the risk of recurrence. Metronidazole, vancomycin and fidaxomicin are used as basic drugs. Fecal transplantation is effective in recurrent disease. In the hospital setting, patients suffering from CDI should be isolated for the entire duration of diarrhea. Surveillance rules also should be applied, together with early treatment of symptomatic patients and prevention of the spread of the infection. Higher incidence of CDI in a ward implies that the local antibiotic prescription habits should be revised.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Clostridioides difficile/isolation & purification , Enterocolitis, Pseudomembranous/diagnosis , Clostridium Infections/microbiology , Czech Republic/epidemiology , Diarrhea/microbiology , Enterocolitis, Pseudomembranous/epidemiology , Enterocolitis, Pseudomembranous/metabolism , Feces/microbiology , Health Policy , Humans , Practice Guidelines as TopicABSTRACT
Proteinase-activated receptors (PARs) were discovered more than 25 years ago and since then, their role in cancer has been under investigation. Research has primarily focused on the receptors located on the membrane of cancer cells and their impact on metabolism, intracellular signalling, and proliferation. Regarding the host response to cancer, studies have predominantly examined the relationship of thrombin receptors (PAR-1, PAR-3, and PAR-4) with blood clotting in distant metastatic spread. However, limited studies have examined the role of PARs, especially PAR-2, in the host anti-tumor immunity. This review article provides insights into the role of PAR-2 on cancer cells and immune competent cells involved in cancer development and progression. It also discussed the current knowledge of the importance of PAR-2 activation at various stages of cancer progression and its association with cancer-related pain.
Subject(s)
Neoplasms , Receptor, PAR-2 , Humans , Receptor, PAR-2/metabolism , Neoplasms/metabolism , Receptor, PAR-1/metabolism , Signal Transduction/physiologyABSTRACT
ABSTRACT: A 41-year-old man was admitted to hospital due to sudden loss of consciousness. A regional brain perfusion SPECT/low-dose CT showed abnormal 99m Tc-HMPAO uptake in the right hemisphere frontotemporally without any other supratentorial or infratentorial radiotracer uptake. A neuropathological examination disclosed a middle cerebral artery aneurysm. Presumably, vessel wall fibrosis prevented collapse. Multiple transmural dissections of the fibrotic aneurysmal wall were the source of the subarachnoid hemorrhage. This interesting image shows that radiotracer accumulation in cerebral artery aneurysms can be a diagnostic pitfall in brain death scintigraphy assessment.
Subject(s)
Brain Death , Brain , Male , Humans , Adult , Brain Death/diagnostic imaging , Brain/diagnostic imaging , Biological Transport , Neuroimaging , Single Photon Emission Computed Tomography Computed TomographyABSTRACT
PURPOSE: A new generation of CT detectors were recently developed with the ability to measure individual photon's energy and thus provide spectral information. The aim of this work was to assess the performance of simultaneous fat and iron quantification using a clinical photon-counting CT (PCCT) and its comparison to dual-energy CT (DECT), MRS and MRI at 3 T. METHODS: Two 3D printed cylindrical phantoms with 32 samples (n = 12 fat fractions between 0 % and 100 %, n = 20 with mixtures of fat and iron) were scanned with PCCT and DECT scanners for comparison. A three-material decomposition approach was used to estimate the volume fractions of fat (FF), iron and soft tissue. The same phantoms were examined by MRI (6-echo DIXON, a.k.a. Q-DIXON) and MRS (multi-echo STEAM, a.k.a. HISTO) at 3 T for comparison. RESULTS: PCCT, DECT, MRI and MRS computed FFs showed correlation with reference fat fraction values in samples with no iron (r > 0.98). PCCT decomposition showed slightly weaker correlation with FFref in samples with added iron (r = 0.586) compared to MRI (r = 0.673) and MRS (r = 0.716) methods. On the other hand, it showed no systematic over- or underestimation. Surprisingly, DECT decomposition-derived FF showed strongest correlation (r = 0.758) in these samples, however systematic overestimation was observed. FF values computed by three-material PCCT decomposition, DECT decomposition, MRI and MRS were unaffected by iron concentration. CONCLUSIONS: This in-vitro study shows for the first time that photon-counting computed tomography may be used for quantification of fat content in the presence of iron deposits.
Subject(s)
Iron , Tomography, X-Ray Computed , Tomography, X-Ray Computed/methods , Magnetic Resonance Imaging/methods , Phantoms, Imaging , AlgorithmsABSTRACT
Small colony variants (SCVs) are subpopulations of a bacterial strain that differ in morphology, growth rate, metabolism, and antibiotic sensitivity from the parent line. They are associated with chronic and difficult-to-treat infections. SCV endocarditis is very rare and usually associated with intracardiac devices. Herein, we report a case of endocarditis caused by SCV-forming Enterococcus faecalis that affected the native heart without any known predisposition.