Accelerated Electron Ionization-Induced Changes in the Myenteric Plexus of the Rat Stomach.

The influence of accelerated electrons on neuronal structures is scarcely explored compared to gamma and X-rays. This study aims to investigate the effects of accelerated electron radiation on some pivotal neurotransmitter circuits (cholinergic and serotonergic) of rats' myenteric plexus. Male Wistar rats were irradiated with an electron beam (9 MeV, 5 Gy) generated by a multimodality linear accelerator. The contractile activity of isolated smooth muscle samples from the gastric corpus was measured. Furthermore, an electrical stimulation (200 µs, 20 Hz, 50 s, 60 V) was performed on the samples and an assessment of the cholinergic and serotonergic circuits was made. Five days after irradiation, the recorded mechanical responses were biphasic-contraction/relaxation in controls and contraction/contraction in irradiated samples. The nature of the contractile phase of control samples was cholinergic with serotonin involvement. The relaxation phase involved ACh-induced nitric oxide release from gastric neurons. There was a significant increase in serotonergic involvement during the first and second contractile phases of the irradiated samples, along with a diminished role of acetylcholine in the first phase. This study demonstrates an increased involvement of serotonergic neurotransmitter circuits in the gastric myenteric plexus caused by radiation with accelerated electrons.

Robotic stereotactic radiosurgery with CyberKnife - brain metastases and fibrinolysis.

OBJECTIVES: Deviations in haemostasis are found in about 50 % of patients with cancer and up to 90% of those with metastatic disease. Many studies investigate the dynamics of the processes of coagulation and fibrinolysis and their role as a predictor of therapeutic response, early relapse, or metastasis risk. BACKGROUND: To investigate the serum levels of urokinase plasminogen activator (uPA) in patients with brain metastases treated with robotic stereotactic radiosurgery (SRS) with CyberKnife. MATERIAL AND METHODS: Serum levels of urokinase plasminogen activator (uPA) were measured in 66 patients with solid tumours, divided into two groups, with oligometastatic disease and brain metastases. In this prospective longitudinal study, the serum levels of uPA were measured before starting the therapy and at the first, third, and sixth months after patients were irradiated with the CyberKnife system. RESULTS: Analysis of serum uPA levels in the post-treatment period showed a statistically significant decrease between the baseline and the 6 months post-treatment time point in both patient groups. The baseline value of serum uPA in the group with lung cancer decreased by 62.7 %, and in the group with other types of cancer - by 60 %. Despite the significant reduction of serum uPA levels 6 months after the treatment, the levels remained significantly higher in both groups than in healthy controls. CONCLUSION: Ongoing research on uPA and cancer will enrich our knowledge and expand the possibilities for clinical utilization of the marker in the oncology setting (Tab. 2, Ref. 18).

Effects of Electron Radiation on Serotonin Signaling and Reactivity of Rat Gastric Smooth Muscle.

Ionizing radiation in radiotherapy can disrupt cellular functions based on radiation type, energy, and dose. However, investigations on the effects of accelerated electrons, particularly on serotonin mediation, are limited. This study aimed to investigate changes in serotonin signal transduction (targeting 5-HT2A and 5-HT2B receptors) in gastric smooth muscle (SM) samples isolated from rats irradiated with accelerated electrons (linear accelerator Siemens Primus S/N 3561) and their effects on serotonin-induced reactions. The radiation effects were examined in samples prepared five days after the procedure. The contractile activity of smooth muscle samples was measured using an isometric method. The expression of 5-HT2A and 5-HT2B receptors was determined by immunohistochemical assay. Increased contractile reactivity to exogenous serotonin (1.10-8-1.10-4 mol/L) was observed in irradiated samples compared to controls. The expression of 5-HT2A and 5-HT2B receptors was significantly increased in the irradiated tissue. By selecting appropriate time intervals between equimolar (1.10-6 mol/L) sequential serotonin exposures, a process of desensitization associated with agonist-induced internalization was established in control samples, which was absent in irradiated samples. In conclusion, irradiation with accelerated electrons affects the agonist-induced receptor internalization of 5-HT2A and 5-HT2B receptors and increases their expression in rat gastric SM, which alters their contractile reactivity to exogenous serotonin.

Markers of activation of coagulation in cancer patients.

BACKGROUND: Prothrombotic tendency is characteristic of tumors. The aim of the study is to investigate the changes in the laboratory parameters for coagulation and fibrinolysis, namely in fibrinogen, thrombin-antithrombin complex (ТАТ), tissue factor (ТF), prothrombin fragment (F1+2), antithrombin III (AT III), D-dimer and screening coagulation tests in cancer patients before initiation of chemotherapy. MATERIALS AND METHODS: Levels of F1+2, fibrinogen, ТАТ, AT III, TF, D-dimer, PT, aPTT and TT were measured baseline in 80 patients with breast and lung cancer before systemic treatment. The same parameters were investigated in 65 healthy volunteers. TF, ТАТ, F1+2 were measured by ELISA; AT III, D-dimer, fibrinogen and screening coagulation tests were measured by automated coagulation system Sysmex CS 2000i.  RESULTS: Levels of F1+2, fibrinogen, ТАТ, TF, and D-dimer in cancer patients were significantly higher than those in the control group, while the levels of ATIII activity were significantly lower (p < 0.001). The highest area under the ROC curve was for D-dimer, which made it a good marker for the risk of thrombosis. CONCLUSION: Higher levels of TF, ТАТ, F1+2, fibrinogen and D-dimer and lower activity of АТ III in cancer patients support our hypothesis of an association between malignant disease and coagulation disorders. Cancer patients are at an increased risk of thrombosis wherefore antithrombotic prophylaxis may be considered (Tab. 6, Fig. 2, Ref. 34). Text in PDF www.elis.sk Keywords: coagulation, fibrinolysis, cancer.

The role of 18F-FDG PET/CT and single isotope 99mTc-tetrofosmin scintigraphy combined with SPECT in diagnosis of multiple endocrine neoplasia type 1 syndrome.

We present a case of a 47-year-old woman with type 1 multiple endocrine neoplasia, primary hyperparathyroidism, insulinoma, and nonfunctioning pituitary adenoma. In July 2017, the patient was referred to the Department of Nuclear Medicine of St George University Hospital in Plovdiv for a PET/CT scan because of persistent hypoglycemic episodes and high serum insulin levels. A whole-body PET/CT examination was performed 65 min after intravenous application of 188 MBq 18F-FDG on a hybrid PET/CT scanner (Biograph mCT 64, Siemens). We detected a low metabolically active lesion 10 mm in diameter (SUVmax - 2.00), located below the left thyroid lobe suspicious for parathyroid adenoma. In the remaining scanned areas there were no PET/CT data for other areas with increased glucose metabolism with malignant characteristics that could be associated with the underlying disease.

Vitamin D levels in patients with non-Hodgkin lymphoma/diffuse large B-cell lymphoma, chronic lymphocytic leukemia and multiple myeloma.

PURPOSE: To investigate serum vitamin D levels in patients newly diagnosed with non-Hodgkin lymphoma/diffuse large B-cell lymphoma (NHL-DLBCL), multiple myeloma (MM) and chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: We measured serum levels of vitamin D by ELISA in 103 patients prior to initiation of treatment, of whom 37 were diagnosed with MM, 32 with CLL and 34 with NHL-DLBCL. RESULTS: Suboptimal serum vitamin D levels (<30 ng/mL) were observed in all 103 patients. In 14 patients, serum vitamin D levels were between 20 and 30 ng/mL, while all other patients had vitamin D deficiency (<20 ng/mL). Severe vitamin D deficiency (<10 ng/mL) was observed in 32.3% of NHL-DLBCL patients, 28.1% of CLL patients and 81% of MM patients. CONCLUSION: We observed low serum vitamin D levels in the majority of patients newly diagnosed with NHL-DLBCL, CLL and MM.

Serum Levels of Vitamin D in Patients with Multiple Myeloma.

AIM: То investigate the serum levels of vitamin D in newly diagnosed patients with multiple myeloma. PATIENTS AND METHODS: In this study we measured the serum levels of vitamin D in 37 patients (19 women, 18 men) at a median age of 68 years and a diagnosis of MM according to the International Myeloma Working Group (IMWG) criteria. The immunoassay tests used for the quantification of 25 (OH) - Vitamin D were original ELISA kits Immundiagnostic and the measurement was done before starting the treatment. RESULTS: Serum levels below the optimum (<30 ng/ml) were recorded in all 37 patients. The median value of vitamin D was 4.3±6.5 mg/ml, the maximum value measured was 24.7 mg/ml, which is below the lower limit of the reference value for deficiency. CONCLUSIONS: In this study, we found extremely low serum vitamin D levels in most of the newly diagnosed MM patients.

Brain Metastases from Non-small-cell Lung Carcinoma - CyberKnife Re-irradiation after Gamma Knife Radiosurgery.

Lung cancer is the most common neoplasia and the most common cause of cancer mortality. The condition is usually diagnosed at a locally advanced or metastatic stage, which is a bad prognostic factor. Around 40% of all oncology patients with brain metastases have lung cancer.Modern linear accelerators allow clinicians to perform radiosurgery and deliver a high radiation dose to low volume with a high dose gradient. Herein we present a 55-year-old male patient who received radiosurgery four times over three years - two times with Gamma Knife and two times with CyberKnife. Re-irradiation gives the opportunity to treat a local progression of a metastasis, which already has been irradiated. A series of control brain magnetic resonance imaging confirmed a good local control of treated lesions with no necrosis in surrounding healthy tissue or significant oedema. The neurological symptoms were completely controlled and the quality of life of the patient improved considerably. Radiosurgery is a prevalent, non-invasive, painless method of treatment with proven clinical results. It may be reused as long as it has clinical benefits to the patient.

Changes in the Contractile Activity and Reactivity to 5-HT of Smooth Muscles of Rats Following Total Body Irradiation with Accelerated Electrons.

BACKGROUND: Besides its "classical" neurotransmitter function in the central and peripheral nervous systems, serotonin, or 5-hydroxytryptamine (5-HT) is also a local hormone in a number of tissues, including those of the GI tract. Radiation is known to be able to disrupt certain functions of the tract, modulated by 5-HT-signaling pathways, or the serotonin receptors themselves. AIM: The present investigation focused on clarifying the nature and extent of influence of an accelerated electron beam with energy of 9 MeV on the serotonergic mediation of healthy smooth muscle gastric tissue of rats following total body irradiation of the animals. MATERIALS AND METHODS: The study involved a control group and two experimental groups of animals exposed to 1 and 5 Gy, respectively, using Siemens Primus S/N 3561. Circular smooth muscle tissues were isolated from rats 1 hour and 18 hours after they were exposed to 1 and 5 Gy and also 5 days after irradiation from the rats that received a dose of 5 Gy in order to investigate the action of exogenous serotonin at increasing concentrations from 10-8 to 10-4 mol/l. The contractile reactivity of each group SM preparations was registered isometrically. RESULTS: Electron beams with energy of 9 MeV did not damage the contractile apparatus of gastric SM of rats and had a stimulating effect on contractility resulting from rapidly developing processes (1 hour) or later occurring once (5 days). CONCLUSIONS: Difference was observed in the importance of the factors of received dose, lapse of time from irradiation to investigation of SM tissues, and exogenous 5-HT concentration for the changes in SM reactivity in serotonin-induced tonic and phasic responses.