Epitranscriptomic Regulations in the Heart.

RNA modifications affect key stages of the RNA life cycle, including splicing, export, decay, and translation. Epitranscriptomic regulations therefore significantly influence cellular physiology and pathophysiology. Here, we selected some of the most abundant modifications and reviewed their roles in the heart and in cardiovascular diseases: N6-methyladenosine (m6A), N6,2'-O-dimethyladenosine (m6Am), N1-methyladenosine (m1A), pseudouridine (?), 5 methylcytidine (m5C), and inosine (I). Dysregulation of epitranscriptomic machinery affecting these modifications vastly changes the cardiac phenotype and is linked with many cardiovascular diseases such as myocardial infarction, cardiomyopathies, or heart failure. Thus, a deeper understanding of these epitranscriptomic changes and their regulatory mechanisms can enhance our knowledge of the molecular underpinnings of prevalent cardiac diseases, potentially paving the way for novel therapeutic strategies. Keywords: Epitranscriptomics, RNA modifications, Epigenetics, m6A, RNA, Heart.

Myocardial m6A regulators in postnatal development: effect of sex.

N6-methyladenosine (m6A) is an abundant mRNA modification affecting mRNA stability and protein expression. It is a highly dynamic process, and its outcomes during postnatal heart development are poorly understood. Here we studied m6A machinery in the left ventricular (LV) myocardium of Fisher344 male and female rats (postnatal days one to ninety; P1-P90) using Western Blot. A downward pattern of target protein levels (demethylases FTO and ALKBH5, methyltransferase METTL3, reader YTHDF2) was revealed in male and female rat LVs during postnatal development. On P1, the FTO protein level was significantly higher in male LVs compared to females.

[Effect of COVID-19 Pandemic on Major Trauma Treated at a Level I Trauma Centre]. / Vliv pandemie Covid-19 na závazné úrazy osetrované v traumacentru I. typu.

PURPOSE OF THE STUDY The paper aims to evaluate the effect of COVID-19 pandemic on a change in the number of major trauma cases, their mechanism and length of hospital stay as seen by a Level I Trauma Centre. MATERIAL AND METHODS The retrospective study included a total of 755 major trauma patients (ISS ≥ 16) treated at our Level I Trauma Centre in the period 2018-2019 ("pre-COVID-19 time") and 2020-2021 ("COVID-19 time"). The effect of COVID-19 infection on the change in the number and nature of major trauma, mechanism of injury, length of treatment during prehospital care, length of hospital stay, and mortality. RESULTS Of the total number of 755 patients with major trauma, in the "pre-COVID-19 time" 399 patients were treated, while in the "COVID-19 time" it was 356 patients (p = 0.10). The mechanism of major trauma did not change, road traffic accidents prevailed (61% vs. 56%, p = 0.25), the proportion of injuries due to falls from height increased (25% vs. 32.5%, p = 0.08), a significant decrease was observed in the category of severe skiing injuries (7 vs. 2, p = 0.003). The severity of injuries evaluated by Injury Severity Score remained unchanged (25 vs. 25, p = 0.08), but an increased number of patients with traumatic brain injury (TBI) marked by the Abbreviate Injury Score (AIS) ≥ 4 was observed (38 vs. 56, p = 0.03). The total length of a hospital stay shortened (18 vs. 15 days, p = 0.04), but the mortality rate spiked (52 vs. 73 patients, p = 0.08). DISCUSSION In the "COVID-19 time", the total number of major trauma cases dropped just like in the other European countries. Despite restrictive measures imposing mobility restrictions, no change was reported in the mechanism of injury, with traffic accidents still prevalent, except for skiing injuries. Unlike the US, we did not see an increase in penetrating injuries due to interpersonal violence or suicidal behaviour. However, there was an increase in the percentage of patients with an isolated TBI as a result of a fall from height. An increase in mortality was reported due to an increase in severe TBI. The length of hospital stay was reduced as a result of efforts to maintain hospital bed availability. CONCLUSIONS During the COVID-19 pandemic, compared to the two years immediately preceding, no significant decrease in the number of major trauma cases was reported, despite the introduction of restrictive measures. The proportion of road traffic injuries remained the same, whereas the number of falls from height slightly increased, which consequently led to an increase in the number of severe TBI. The number of penetrating injuries due to acts of violence did not increase, but due to the lockdown there was a significant decrease in severe skiing-related injuries. The anti-epidemic measures in place did not prolong the pre-hospital care for severely injured patients. Key words: major trauma, Injury Severity Score, COVID-19, mechanism of injury.

Sex-dependent effect of perinatal hypoxia on cardiac tolerance to oxygen deprivation in adults.

Epidemiological studies have demonstrated a relationship between the adverse influence of perinatal development and increased risk of ischemic heart disease in adults. From negative factors to which the fetus is subjected, the most important is hypoxia. The fetus may experience hypoxic stress under different conditions, including pregnancy at high altitude, pregnancy with anemia, placental insufficiency, and heart, lung, and kidney disease. One of the most common insults during the early stages of postnatal development is hypoxemia due to congenital cyanotic heart defects. Experimental studies have demonstrated a link between early hypoxia and increased risk of ischemia/reperfusion injury (I/R) in adults. Furthermore, it has been observed that late myocardial effects of chronic hypoxia, experienced in early life, may be sex-dependent. Unlike in males, perinatal hypoxia significantly increased cardiac tolerance to acute I/R injury in adult females, expressed as decreased infarct size and lower incidence of ischemic arrhythmias. It was suggested that early hypoxia may result in sex-dependent programming of specific genes in the offspring with the consequence of increased cardiac susceptibility to I/R injury in adult males. These results would have important clinical implications, since cardiac sensitivity to oxygen deprivation in adult patients may be significantly influenced by perinatal hypoxia in a sex-dependent manner.

Developmental and sex differences in cardiac tolerance to ischemia-reperfusion injury: the role of mitochondria 1.

Age and sex play an essential role in the cardiac tolerance to ischemia-reperfusion injury: cardiac resistance significantly decreases during postnatal maturation and the female heart is more tolerant than the male myocardium. It is widely accepted that mitochondrial dysfunction, and particularly mitochondrial permeability transition pore (MPTP) opening, plays a major role in determining the extent of cardiac ischemia-reperfusion injury. We have observed that the MPTP sensitivity to the calcium load differs in mitochondria isolated from neonatal and adult myocardium, as well as from adult male and female hearts. Neonatal and female mitochondria are more resistant both in the extent and in the rate of mitochondrial swelling induced by high calcium concentration. Our data further suggest that age- and sex-dependent specificity of the MPTP is not the result of different amounts of ATP synthase and cyclophilin D: neonatal and adult hearts, similarly as the male and female hearts, contain comparable amounts of MPTP and its regulatory protein cyclophilin D. We can speculate that the lower sensitivity of MPTP to the calcium-induced swelling may be related to the higher ischemic tolerance of both neonatal and female myocardium.

Change of tear osmolarity after refractive surgery.

  Purpose: To compare the influence of the LASIK and ReLEx SMILE refractive method on tear osmolarity Methods: Prospective non-randomized comparative study. We evaluated the results in two groups of patients who underwent binocular refractive surgery to remove myopia and possibly astigmatism in the eye clinic of Horní Pocernice. In each group were 15 patients (30 eyes), patients of one group undergoing FS-LASIK refractive surgery, in the second group a ReLEx SMILE procedure. Bilateral measurement of the tear film osmolarity using the TearLab instrument on the day of surgery, the first day after surgery, one month and 3 months after surgery was performed on each patient. Results: The mean preoperative value of the osmolarity of the tear film was practically the same in both groups, in the ReLEx SMILE group 294.9 ± 13.4 mOsm/l and in the FS-LASIK group 296.4 ± 13.1. One and three months after the surgery in the ReLEx SMILE group, these values increased to 301.4 and 296.4 ± 13.3 mOsm/l respectively, the elevation of values one month after surgery was statistically significant. In the FS-LASIK group, one month after surgery, the osmolarity was 320.1 ± 14.7, three months postoperatively 306.5 ± 13.1 mOsm / l. Both of these values compared to the preoperative value were statistically significantly higher. The increase of the mean osmolarity was statistically significantly higher in the FS-LASIK group compared to the ReLEx SMILE. Three months after surgery, the difference between groups was not statistically significant. Conclusion: In our group of patients, after the FS-LASIK refraction procedure, we noted a higher mean osmolarity of tear film in comparison with patients after the ReLEx SMILE in all evaluated timepoints (1 day, 1 month and 3 months after surgery). We consider ReLEx SMILE as a method with less impact on the quality of tear film, with a faster return to original osmolarity and potentially higher patient comfort. Key words: Tear osmolarity, Relex SMILE, FS-LASIK.

[Avoidance of axillary lymph node dissection in breast cancer patients with metastatic sentinel node - a pilot study]. / Vynechání disekce axily u karcinomu prsu pri pozitivní sentinelové uzline - pilotní studie.

INTRODUCTION: Axillary lymph node dissection (ALND) is a standard procedure for locoregional control in metastatic sentinel lymph nodes (SN). A number of studies have provided evidence that avoiding ALND does not worsen the general prognosis. METHODS: A group of 249 female patients with sentinel lymph node biopsy was analysed retrospectively for a 3-year period. The patients were divided into two groups - with non-metastatic SN and with metastatic SN. In the metastatic SN group, the patients were further divided into a group with ALND and a group without ALND, and additional lymph nodes (non-sentinel) in ALND and oncological treatment were evaluated. The goal was to find out whether ALND and oncological treatment affect the disease-free interval (DFI) and overall survival (OS) in the group of patients with metastatic SN and to compare the results with the control group. The histopathology and biology of the primary tumour, its size and the number of metastatic SN were subsequently evaluated as the factors that may be useful for predicting metastatic non-sentinel lymph node positivity. RESULTS: There was a high risk of metastatic non-sentinel lymph nodes in the cases of metastatic SN (63%). Addition of ALND does not prolong either DFI or DFS without post-operative radiotherapy and systemic oncological treatment, both of which can provide a comparable length of DFI as well as DFS without ALND. Patients with metastatic SN with and without ALND had a DFI of 70 and 72 months, respectively, and a 5-year survival of 84% and 80%, respectively. Tumours over 2 cm, tumours with high proliferative activity and a high grade can be regarded as predictors of metastatic non-sentinel lymph nodes. CONCLUSION: In a small patient group it has been demonstrated that the avoidance of ALND in 1 or 2 metastatic SN, regardless of the prognostic factors, does not affect either DFI or DFS if adjuvant oncological treatment is administered. High-grade tumours, tumours with high proliferative activity and tumours larger than 2 cm carry a significantly higher risk of metastatic non-sentinel lymph nodes. Nowadays, the avoidance of ALND in metastatic SN is not a lege artis procedure; further large studies are needed to create scientific guidelines.Key words: metastatic sentinel lymph node - avoidance of axillary dissection - breast cancer.

Tumour necrosis factor-α contributes to improved cardiac ischaemic tolerance in rats adapted to chronic continuous hypoxia.

AIM: It has been demonstrated that tumour necrosis factor-alpha (TNF-α) via its receptor 2 (TNFR2) plays a role in the cardioprotective effects of preconditioning. It is also well known that chronic hypoxia is associated with activation of inflammatory response. With this background, we hypothesized that TNF-α signalling may contribute to the improved ischaemic tolerance of chronically hypoxic hearts. METHODS: Adult male Wistar rats were kept either at room air (normoxic controls) or at continuous normobaric hypoxia (CNH; inspired O2 fraction 0.1) for 3 weeks; subgroups of animals were treated with infliximab (monoclonal antibody against TNF-α; 5 mg kg(-1), i.p., once a week). Myocardial levels of oxidative stress markers and the expression of selected signalling molecules were analysed. Infarct size (tetrazolium staining) was assessed in open-chest rats subjected to acute coronary artery occlusion/reperfusion. RESULTS: CNH increased myocardial TNF-α level and expression of TNFR2; this response was abolished by infliximab treatment. CNH reduced myocardial infarct size from 50.8 ± 4.3% of the area at risk in normoxic animals to 35.5 ± 2.4%. Infliximab abolished the protective effect of CNH (44.9 ± 2.0%). CNH increased the levels of oxidative stress markers (3-nitrotyrosine and malondialdehyde), the expression of nuclear factor κB and manganese superoxide dismutase, while these effects were absent in infliximab-treated animals. CNH-elevated levels of inducible nitric oxide synthase and cyclooxygenase 2 were not affected by infliximab. CONCLUSION: TNF-α plays a role in the induction of ischaemia-resistant cardiac phenotype of CNH rats, possibly via the activation of protective redox signalling.

[Phyllodes breast tumors]. / Fyloidní nádory prsu.

INTRODUCTION: Phyllodes tumour is a breast tumour occurring very rarely. It accounts for only in 1% of all cases of breast tumour. The diagnosis of phyllodes tumours can be difficult in consideration of the small number of cases. Treatment of phyllodes tumours is always surgical. METHODS: In 2004-2013, we operated on twelve female patients with phyllodes tumours out of the total number of 1564 surgeries for breast tumours (0.8%) at the Department of Surgery at Teaching Hospital in Pilsen. We evaluated the age, the biological behaviour of the tumour depending on the tumour size and duration, the distant metastases, therapy and survival. RESULTS: The average age at the time of surgery was fifty years (2684), the duration of disease to the surgical solution ranged from one month to ten years. Tumour size was in the range of two to twenty-nine centimetres, tumours measuring less than five centimetres were always benign. Tumour excision for benign phyllodes tumour was performed seven times. Malignant phyllodes tumour was diagnosed five times with mastectomy performed in each case, and the axilla was exenterated in three cases where nodes were benign in each of them. In one case, mastectomy was followed by radiotherapy because the tumour reached the edge of the resected part; the other patients were only monitored. In two patients, tumour spreading into the lungs was diagnosed at five to ten months after breast surgery. One patient with generalized disease died, the other ones live with no local recurrence of this disease. Median survival is fifty-two months; the disease-free interval is fifty months. CONCLUSION: The results show that if phyllodes tumour is diagnosed in time, it is almost exclusively benign. If the case history is longer and the tumour is growing, the likelihood of malignancy increases. Surgical treatment is also sufficient in the case of malignant forms. The breast surgery does not need to be supplemented with exenteration of axilla.Key words: breast - phyllodes tumour.

Involvement of PKCepsilon in cardioprotection induced by adaptation to chronic continuous hypoxia.

Continuous normobaric hypoxia (CNH) renders the heart more tolerant to acute ischemia/reperfusion injury. Protein kinase C (PKC) is an important component of the protective signaling pathway, but the contribution of individual PKC isoforms under different hypoxic conditions is poorly understood. The aim of this study was to analyze the expression of PKCepsilon after the adaptation to CNH and to clarify its role in increased cardiac ischemic tolerance with the use of PKCepsilon inhibitory peptide KP-1633. Adult male Wistar rats were exposed to CNH (10 % O(2), 3 weeks) or kept under normoxic conditions. The protein level of PKCepsilon and its phosphorylated form was analyzed by Western blot in homogenate, cytosolic and particulate fractions; the expression of PKCepsilon mRNA was measured by RT-PCR. The effect of KP-1633 on cell viability and lactate dehydrogenase (LDH) release was analyzed after 25-min metabolic inhibition followed by 30-min re-energization in freshly isolated left ventricular myocytes. Adaptation to CNH increased myocardial PKCepsilon at protein and mRNA levels. The application of KP-1633 blunted the hypoxia-induced salutary effects on cell viability and LDH release, while control peptide KP-1723 had no effect. This study indicates that PKCepsilon is involved in the cardioprotective mechanism induced by CNH.

[Sarcoma of the chest wall after radiotherapy for breast carcinoma - a case report]. / Sarkom hrudní steny po ozárení pro karcinom prsu kazuistika.

INTRODUCTION: Sarcoma occurring in soft tissues after radiotherapy is a rare complication of radiation treatment of tumours. It was most often described after treatment for breast cancer as well as for non-Hodgkin lymphoma and cervical carcinoma. The time interval between the radiation therapy and the development of the sarcoma can be very wide. Treatment demands radical surgical resection of the sarcoma with the edge of the resected tissue without tumour cells. In some cases, this is followed by chemotherapy or radiotherapy. The median survival time is 23 months, the longest survival being associated with sarcomas removed in a radical way. CASE REPORT: We present the case of a female patient with recurring leiomyosarcoma of the chest wall after radiotherapy for cancer of the right breast. In 2006, this 62-year-old patient was operated on to keep her right breast with axilla exenteration. After the surgery, hormonal therapy was followed by adjuvant radiotherapy of the right breast and the adjacent axilla. We used a linear accelerator and the total amount of radiation was 50 Gy (2 Gy fractionally once a day, five days a week). Four years after the operation, leiomyosarcoma was diagnosed in the pectoral muscle at the site where the tumour of the right breast had been excised. Between 2011 and 2013, a total of five operations of re-occurring sarcoma were performed - two excisions of the tumour, a mastectomy, rib resection and, at last, block resection of the chest wall. Adjuvant oncological treatment was not indicated. The patient, now being 69 years old, is still in a good physical and mental condition without any generalization of the disease. CONCLUSION: Sarcoma of the chest wall is a relatively rare consequence of radiotherapy for breast cancer. Sarcoma treatment involves radical surgical resection of the tumour whenever possible. The surgery is mostly followed by radiotherapy which, however, is impossible in a patient after breast-preserving surgery for carcinoma with radiotherapy. Chemotherapy is not very effective in sarcomas. Therefore, the operation needs to be performed by an experienced surgeon in a sufficiently radical way.

[Difficult diagnosis of breast carcinoma]. / Obtízná diagnostika karcinomu prsu.

The breast carcinoma is the most frequent cancer in women. The diagnosis has certain rules but sometimes it brings diagnostic difficulties. The aim of this article is to point out specific cases of breast cancer and to transmit our practical experience with the situations when ordinary diagnostic methods failed. The authors present four cases of the patients with breast carcinoma.

N-acetylcysteine treatment prevents the up-regulation of MnSOD in chronically hypoxic rat hearts.

Chronic intermittent hypoxia (CIH) is associated with increased production of reactive oxygen species that contributes to the adaptive mechanism underlying the improved myocardial ischemic tolerance. The aim was to find out whether the antioxidative enzyme manganese superoxide dismutase (MnSOD) can play a role in CIH-induced cardioprotection. Adult male Wistar rats were exposed to intermittent hypobaric hypoxia (7000 m, 8 h/day, 25 exposures) (n=14) or kept at normoxia (n=14). Half of the animals from each group received N-acetylcysteine (NAC, 100 mg/kg) daily before the hypoxic exposure. The activity and expression of MnSOD were increased by 66 % and 23 %, respectively, in the mitochondrial fraction of CIH hearts as compared with the normoxic group; these effects were suppressed by NAC treatment. The negative correlation between MnSOD activity and myocardial infarct size suggests that MnSOD can contribute to the improved ischemic tolerance of CIH hearts.

[Harmatoma of the breast--case report]. / Hamartom prsu--kazuistika.

OBJECTIVE: To describe rare hamartoma of the breast in a 31-year-old female. DESIGN: Case report. SETTINGS: Department of Special Diagnostics SPAU, Charles University Hospital Pilsen. SUBJECT AND METHOD: A 31-year-old female was examined for breast asymmetry. A huge tumor was revealed in right mammary gland using ultrasonography. Encapsulated tumor 10x10x10 cm was removed. Subsequent histological examination revealed breast hamartoma. The patient is alive and well without signs of disease one year after excision. CONCLUSION: Hamartoma of the breast is a rare benign tumor. Diagnostics is very complicated and it is almost impossible to establish correct diagnosis preoperatively. A simple excision is a sufficient treatment with good curative effect.