B-type Natriuretic Peptide as a Marker of Different Forms of Systemic Sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is an autoimmune connective tissue disease which affects various tissues and organs, including skin, lungs, kidneys, gastrointestinal tract and cardiovascular system. Cardiac involvement is the most commonly recognized problem and a significant cause of morbidity. The brain natriuretic peptide (BNP) is a previously known marker of elevated cardiovascular risk in SSc, but the levels of BNP in various forms of SSc have not been investigated so far. AIM: The aim of our study was to evaluate the influence of SSc on the function of the right ventricle and the right atrium using the echocardiographic parameters. Moreover, we examined the levels of BNP in different forms of SSc as well as the association of disease severity with the plasma concentrations of BNP. METHODS: We included 42 patients with newly diagnosed SSc and patients whose disease had been diagnosed earlier. SSc patients and non-SSc control patients were examined by using echocardiography and the concentrations of BNP were determined. RESULTS: We analyzed differences in the parameters of right ventricle (RV) function and right atrium (RA) function between SSc patients and healthy controls. The two groups had similar distribution of gender, but SSc patients were significantly older than controls. RV wall thickness was increased in SSc patients (p<0.001), while right ventricular end-systolic area (RVESA; p=0.408) and right ventricular end-diastolic area (RVEDA; p=0.368) did not differ among the examinees. In contrast, RA minor-axis dimension (p=0.001) and the tricuspid annular plane systolic excursion (TAPSE) (p=0.001) were significantly higher in SSc patients. Also, we analyzed differences in brain natriuretic peptide (BNP) concentrations between diffuse cutaneous systemic sclerosis (DSSc) and limited cutaneous systemic sclerosis (LSSc) patients. DSSc patients had significantly higher concentrations of BNP. We found that levels of BNP were in significant positive correlations with age (p=0.007), disease duration (p=0.023), C reactive protein (CRP) (p=0.032), right ventricle fractional area change (FAC) (p=0.022), pulmonary vascular resistance (PVR) and Rodnan score (p=0.019). CONCLUSIONS: Given the obtained results, the laboratory determination of BNP could be useful in differentiating different forms of systemic sclerosis as well as in predicting the severity of the disease and future cardiovascular complications.

Influence of occupational exposure to low-dose ionizing radiation on the plasma activity of superoxide dismutase and glutathione level.

BACKGROUND/AIM: During exposure to low-level doses (LD) of ionizing radiation (IR), the most of harmful effects are produced indirectly, through radiolysis of water and formation of reactive oxygen species (ROS). The antioxidant enzymes--superoxide dismutase (SOD): manganese SOD (MnSOD) and copper-zinc SOD (CuZnSOD), as well as glutathione (GSH), are the most important intracellular antioxidants in the metabolism of ROS. Overproduction of ROS challenges antioxidant enzymes. The aim of this study was to examine if previous exposure to low doses of IR induces adaptive response by means of stimulation of intracellular antioxidant defense system. METHODS: We investigated a group of medical workers occupationally exposed to IR (n = 44), 29 male and 15 female. The controls (n = 33) consisted of medical workers not exposed to IR, 23 male and 10 female. The examinees from both groups worked in the same environment and matched in crucial characteristics. All measurements were performed by a calibrated thermoluminiscent dosimeter type CaF2:Mn. SOD activity and GSH content were measured spectrophotometrically in the plasma of both groups of medical workers. Half of each blood sample was irradiated by 2Gy of gamma radiation, dose-rate 0.45 Gy/min, and the distance from the source of 74 cm. RESULTS: The dosimetry results indicate that occupational doses were very low. Our results confirmed significantly higher SOD activity in the exposed vs. unexposed workers (p < 0.00006). SOD activity after irradiation of blood samples failed to show a significant difference between the exposed workers and the controls (p = 0.905), even the difference in each group before and after the irradiation was significant. In blood samples of the exposed workers expression of enzymes after the irradiation, was not as high as in the controls, or even in the case of the exposed in nuclear medicine personnel, SOD activity was decreased. There were no significant differences in the content of GSH between the groups. CONCLUSION: Our results pointed out that occupational exposure to low doses of IR compromised mitochondrial function. During occupational exposure, the activity of antioxidant enzymes was increased as a protection against the increased production of ROS. After high-dose irradiation dysfunction of mitochondrial system was noticed, suggesting the break-down of antioxidant defense and failure of an adaptive response. Therefore, the "chronic oxidative stress" might reduce antioxidant defense in the case of accidental exposure to high doses of IR. It could indirectly increase the incidence of some other "free radicals' diseases" in occupationally exposed personnel.

[Occupational exposure to ionizing radiation and the occurrence of cataract]. / Profesionalna ekspozicija jonizujucem zracenju i katarakta.

Radiation cataract is one of ensuing effects of ionizing radiation, since its threshold dose under which it does not occur, and above which it shows dose dependency, has been observed. Clinical course of radiation cataract is identical for all the types of ionizing radiation and is very typical. Minimal dose for progressive cataract formation is determined by the type of radiation, i.e., its relative biological efficacy, dose, and the duration of the exposure period. Theoretically, threshold dose existence does not exclude the incidence of cataract formation under significantly smaller doses, as well. The aim of this study was to analyze the incidence of cataract formation among the medical staff professionally exposed to ionizing radiation. Neither of the diagnosed cataracts had typical morphology, nor was the correlation established between the dose, exposure time, and the cataract formation. All the diagnosed cataracts were described as premature, and therefore ionizing radiation was considered as a co-factor in premature cataract formation in the examined groups.