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.
- MeSH
- chronická nemoc MeSH
- hemodynamika MeSH
- lidé MeSH
- nemoci cév * komplikace MeSH
- perfuze MeSH
- plíce diagnostické zobrazování MeSH
- plicní embolie * komplikace diagnostické zobrazování MeSH
- plicní hypertenze * diagnostické zobrazování MeSH
- retrospektivní studie MeSH
- senioři MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
EuCd_{2}As_{2} is now widely accepted as a topological semimetal in which a Weyl phase is induced by an external magnetic field. We challenge this view through firm experimental evidence using a combination of electronic transport, optical spectroscopy, and excited-state photoemission spectroscopy. We show that the EuCd_{2}As_{2} is in fact a semiconductor with a gap of 0.77 eV. We show that the externally applied magnetic field has a profound impact on the electronic band structure of this system. This is manifested by a huge decrease of the observed band gap, as large as 125 meV at 2 T, and, consequently, by a giant redshift of the interband absorption edge. However, the semiconductor nature of the material remains preserved. EuCd_{2}As_{2} is therefore a magnetic semiconductor rather than a Dirac or Weyl semimetal, as suggested by ab initio computations carried out within the local spin-density approximation.
- Publikační typ
- časopisecké články MeSH
The forensically important genus Thanatophilus Leach, 1815 (Coleoptera: Silphidae) is a widespread group of carrion beetles that occupies the Holarctic and Afrotropical realms. It has recently received more recognition, as its species are frequently detected on large carrion, including humans, and can be useful in estimating the time of colonization (TOC) and the post-mortem interval (PMI). The immature stages of Thanatophilus sinuatus (Fabricius, 1775) were reared on three different meat diets (pork liver, pork muscle, and chicken muscle). Diet influence on some of the essential life history traits of the species was examined for different populations. Our findings indicated an accelerated development on pork muscle followed closely by pork liver and a prolonged development on chicken muscle. The diet significantly affected the size, and the body condition (weight/ size) as both pork muscle and liver produced individuals in better physical condition (larger and heavier). The impact of two cyclic photoperiod regimes (16 h Light (L): 8 h Dark (D) and 12 h L: 12 h D) was further evaluated and indicated no significant variability.
- Klíčová slova
- development time, necrophagous, nutritional ecology, photoperiod, survival,
- MeSH
- brouci * MeSH
- dieta MeSH
- lidé MeSH
- rozmnožování MeSH
- stravovací zvyklosti MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Tacrine was the first drug used in the therapy of Alzheimer's disease (AD) and is one of the leading structures frequently pursued in the drug discovery of novel candidates for tackling AD. However, because tacrine has been withdrawn from the market due to its hepatotoxicity, ascribed to specific metabolites, concerns are high about the toxicity profile of newly developed compounds related to tacrine. From the point of view of drug safety, the formation of metabolites must be uncovered and analyzed. Bearing in mind that the main culprit of tacrine hepatotoxicity is its biotransformation to hydroxylated metabolites, human liver microsomes were used as a biotransformation model. Our study aims to clarify phase I metabolites of three potentially non-toxic tacrine derivatives (7-methoxytacrine, 6-chlorotacrine, 7-phenoxytacrine) and to semi-quantitatively determine the relative amount of individual metabolites as potential culprits of tacrine-based hepatotoxicity. For this purpose, a new selective UHPLC-Orbitrap method has been developed. Applying UHPLC-Orbitrap method, two as yet unpublished tacrine and 7-methoxytacrine monohydroxylated metabolites have been found and completely characterized, and the separation of ten dihydroxylated tacrine and 7-methoxytacrine metabolites was achieved for the first time. Moreover, the structures of several new metabolites of 7-phenoxytacrine and 6-chlorotacrine have been identified. In addition, the relative amount of these newly observed metabolites was determined. Based on the results and known facts about the toxicity of tacrine metabolites published so far, it appears that 7-phenoxytacrine and 6-chlorotacrine could be substantially less hepatotoxic compared to tacrine, and could potentially pave the way for metabolically safe molecules applicable in AD therapy.
- Klíčová slova
- 6-chlorotacrine, 7-methoxytacrine, 7-phenoxytacrine, Human liver microsomes biotransformation, Tacrine, Ultra-High-Performance-Liquid-Chromatography-Mass-Spectrometry (UHPLC-MS/MS),
- MeSH
- Alzheimerova nemoc * farmakoterapie metabolismus MeSH
- cholinesterasové inhibitory chemie MeSH
- jaterní mikrozomy metabolismus MeSH
- lékové postižení jater * metabolismus MeSH
- lidé MeSH
- takrin MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- cholinesterasové inhibitory MeSH
- takrin MeSH
Coleoptera are currently considered a fundamental tool to help solve criminal investigations, allowing forensic entomologists to estimate post-mortem intervals and obtain other ecology-related information. Thanatophilus rugosus (Linnaeus, 1758) is an important necrophagous beetle distributed through most of the Palaearctic region, where it is readily found on human bodies and animal carcasses. In this study, the new thermal summation models for all the developmental stages of Thanatophilus rugosus are provided. Beetles were reared at six different constant and ecologically relevant temperatures (12, 14, 16, 18, 20, and 22 °C), and their developmental times were measured. Thermal summation constants were calculated for each developmental stage (egg, three larval instars, post-feeding stage, and pupa).
- MeSH
- brouci růst a vývoj MeSH
- forenzní entomologie metody MeSH
- stravovací zvyklosti MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Insect pupae sampled at a death scene may be used to estimate the post-mortem interval. The pupal age is however difficult to estimate, as there are no good quantitative markers for the age of a pupa. We present a novel method for pupal age estimation based on the quantification of contrast in intensity between the eyes of a pupa and the middle grey photography card as a standard background. The intensity is measured on a standardized scale from 0 (perfect black) to 255 (perfect white) using computer graphical software and pictures of the eye and the background taken with a stereomicroscope. Eye-background contrast is calculated by subtracting the average intensity of the eye from the average intensity of the background. The method was developed and validated using pupae of Necrodes littoralis (Linnaeus, 1758) (Coleoptera: Silphidae), one of the most abundant beetle species on human cadavers in Central Europe. To develop the model, pupae were reared in 17, 20 and 23 °C, with a total of 120 specimens. The method was validated by three raters, using in total 182 pupae reared in 15, 17, 20, 23 and 25 °C. We found a gradual increase in eye-background contrast with pupal age. Changes followed generalized logistic function, with almost perfect fit of the model. Using our method pupal age was estimated with the average error of 8.1 accumulated degree-days (ADD). The largest error was 27.8 ADD and 95% of age estimates had errors smaller than 20 ADD. While using the method, different raters attained similar accuracy. In conclusion, we have demonstrated that eye-background contrast is a good quantitative marker for the age of N. littoralis pupae. Contrast measurements gave accurate estimates for pupal age. Our method is thus proven to be a candidate for a reliable approach to age insect pupae in forensic entomology.
- MeSH
- barva MeSH
- brouci fyziologie MeSH
- forenzní entomologie metody MeSH
- kukla fyziologie MeSH
- mikroskopie MeSH
- pigmentace MeSH
- počítačová grafika MeSH
- reprodukovatelnost výsledků MeSH
- software MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Gastroesophageal reflux disease (GERD) is a rather common disease with a prevalence reaching up to 10 or 20% in the western world. The most specific symptoms which point to the diagnosis of GERD are feelings of heartburn and the regurgitation of acidic stomach contents into the esophagus. However, a certain number of patients do not respond to standard therapy, and in these cases, it is necessary to resort to other treatment methods, such as laparoscopic fundoplication or electrostimulation of the lower esophageal sphincter. The aim of our work was to design and manufacture a miniature, battery-less stimulator to provide electric stimulation of the lower esophageal sphincter, which could be implanted deep into the submucosa of the distal esophagus. The main goal was to provide a battery-less system as opposed to traditional battery neurostimulators to reduce the size and weight of the device. An electronic prototype of a wirelessly powered implantable device was developed. We used animal models for the experiments. The device is designed to treat GERD via electrical stimulation of the muscularis propria. It is implanted into the submucosal pocket by the lower esophageal sphincter with an endoscope. This method of implantation is superior to esophageal stimulators used today because of very low invasiveness of the surgery. Bipolar neurostimulation via two gold-plated leads is provided. The device does not have any source of energy; it is powered wirelessly which reduces the risk of potential battery leakage and reduces the overall dimensions.
- Publikační typ
- časopisecké články MeSH
Gastric dysmotility can be a sign of common diseases such as longstanding diabetes mellitus. It is known that the application of high-frequency low-energetic stimulation can help to effectively moderate and alleviate the symptoms of gastric dysmotility. The goal of our research was the development of a miniature, endoscopically implantable device to a submucosal pocket. The implantable device is a fully customized electronics package which was specifically designed for the purpose of experiments in the submucosa. The device was endoscopically inserted into the submucosal pocket of a pig stomach and partially severed pig side in order to adequately simulate a live animal model. The experiment confirmed that the designed device can be implanted into the submucosa and is capable of the measurement of sensor data and the transmission of this data wirelessly in real time to a computer outside of the body. After proving that the device can be implanted submucosally and transmit data, further experiments can now be performed, primarily with an electrogastrography (EGG) instrument and implantable device with tissue stimulation capability.
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: Early diagnosis of the appendiceal carcinoid during first trimester of pregnancy. DESIGN: Case report. SETTING: Department of Obstetrics and Gynaecology, Merciful Brothers Hospital, Brno. METHODS: Own observation, review of literature. CONCLUSION: In case of unclear clinical or intraoperative finding, the appendectomy may reveal a serious disease. Thorough examination of the appendix should be a part of every gynaecological operation.
- Klíčová slova
- appendix pregnancy., carcinoid, neuroendocrine tumor,
- MeSH
- apendektomie MeSH
- apendix * MeSH
- dospělí MeSH
- gynekologie * MeSH
- karcinoid patologie chirurgie MeSH
- lidé MeSH
- nádorové komplikace v těhotenství patologie chirurgie MeSH
- nádory apendixu patologie chirurgie MeSH
- těhotenství MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- přehledy MeSH
OBJECTIVE: Subclinical hypothyroidism (SH) is associated with a moderately elevated risk of heart failure events among older adults. The objective of our prospective study was to assess the impact of thyroid hormone replacement therapy (HRT) with low doses of L-thyroxine (6.25-25 µg/day) on left ventricular diastolic function in patients with SH. MATERIALS AND METHODS: 33 patients with SH and 25 healthy controls were involved. All participants underwent standard echocardiography and Doppler imaging at baseline and, the patient group, also after a course of HRT. RESULTS: At baseline, patients with SH showed significantly lower E (0.79 ± 0.22 vs. 0.93 ± 0.19, p < 0.001), E/A ratio (1.19 ± 0.29 vs. 1.31 ± 0.25, p < 0.003), and higher intraventricular septum thickness (IVST) (0.99 ± 0.14 vs. 0.89 ± 0.18, p < 0.001) in comparison with healthy controls. After 6 months of therapy, the E/A ratio underwent significant increase (1.28 ± 0.21 vs. 1.19 ± 0.29, p < 0.001), while the IVS displayed a robust reduction (0.92 ± 0.16 vs. 0.99 ± 0.14, p < 0.001). CONCLUSIONS: HRT with low-dosed L-thyroxine may improve left ventricular diastolic function in patients with SH.
- Klíčová slova
- Echocardiography, Heart failure, Left ventricular diastolic function, Subclinical hypothyroidism,
- MeSH
- dopplerovská echokardiografie MeSH
- dospělí MeSH
- dysfunkce levé srdeční komory chemicky indukované MeSH
- funkce levé komory srdeční účinky léků MeSH
- hormonální substituční terapie škodlivé účinky MeSH
- hypotyreóza komplikace farmakoterapie MeSH
- lidé středního věku MeSH
- lidé MeSH
- prospektivní studie MeSH
- studie případů a kontrol MeSH
- thyroxin škodlivé účinky MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Názvy látek
- thyroxin MeSH
