[Dual energy computed tomography in diagnosis of urolithiasis: a new method for determining the chemical composition of urinary stones].

The "gold standard" for the diagnosis and evaluation of urinary stones is native computed tomography, which allows determining stone localization and size of with high accuracy. However, this imaging technique has limited diagnostic usefulness in determining the stone chemical composition. The newly introduced method of dual-energy computed tomography, based on obtaining images at two different energy levels is highly effective in determining the composition of urinary stones. The review outlines the principles and methods of performing dual-energy computed tomography using various scanners. The authors analyze the results of using this method for diagnosing urolithiasis, determining the stone chemical composition and point out the limitations and difficulties encountered in its application.

The sarcopenia and physical frailty in older people: multi-component treatment strategies (SPRINTT) project: description and feasibility of a nutrition intervention in community-dwelling older Europeans.

BACKGROUND: The "Sarcopenia and Physical Frailty in Older People: Multicomponent Treatment Strategies" (SPRINTT) project sponsored a multi-center randomized controlled trial (RCT) with the objective to determine the effect of physical activity and nutrition intervention for prevention of mobility disability in community-dwelling frail older Europeans. We describe here the design and feasibility of the SPRINTT nutrition intervention, including techniques used by nutrition interventionists to identify those at risk of malnutrition and to carry out the nutrition intervention. METHODS: SPRINTT RCT recruited older adults (≥ 70 years) from 11 European countries. Eligible participants (n = 1517) had functional limitations measured with Short Physical Performance Battery (SPPB score 3-9) and low muscle mass as determined by DXA scans, but were able to walk 400 m without assistance within 15 min. Participants were followed up for up to 3 years. The nutrition intervention was carried out mainly by individual nutrition counseling. Nutrition goals included achieving a daily protein intake of 1.0-1.2 g/kg body weight, energy intake of 25-30 kcal/kg of body weight/day, and serum vitamin D concentration ≥ 75 mmol/L. Survey on the method strategies and feasibility of the nutrition intervention was sent to all nutrition interventionists of the 16 SPRINTT study sites. RESULTS: Nutrition interventionists from all study sites responded to the survey. All responders found that the SPRINTT nutrition intervention was feasible for the target population, and it was well received by the majority. The identification of participants at nutritional risk was accomplished by combining information from interviews, questionnaires, clinical and laboratory data. Although the nutrition intervention was mainly carried out using individual nutritional counselling, other assisting methods were used as appropriate. CONCLUSION: The SPRINTT nutrition intervention was feasible and able to adapt flexibly to varying needs of this heterogeneous population. The procedures adopted to identify older adults at risk of malnutrition and to design the appropriate intervention may serve as a model to deliver nutrition intervention for community-dwelling older people with mobility limitations.

Is maternal progesterone actually independent of the fetal steroids?

Progesterone and estradiol are the foremost steroid hormones in human pregnancy. However, the origin of maternal progesterone has still not been satisfactorily explained, despite the generally accepted opinion that maternal LDL-cholesterol is a single substrate for placental synthesis of maternal progesterone. The question remains why the levels of progesterone are substantially higher in fetal as opposed to maternal blood. Hence, the role of the fetal zone of fetal adrenal (FZFA) in the synthesis of progesterone precursors was addressed. The FZFA may be directly regulated by placental CRH inducing an excessive production of sulfated 3beta-hydroxy-5-ene steroids such as sulfates of dehydroepiandrosterone (DHEAS) and pregnenolone (PregS). Due to their excellent solubility in plasma these conjugates are easily transported in excessive amounts to the placenta for further conversion to the sex hormones. While the significance of C19 3beta-hydroxy-5-ene steroid sulfates originating in FZFA for placental estrogen formation is mostly recognized, the question "Which maternal and/or fetal functions may be served by excessive production of PregS in the FZFA?" - still remains open. Our hypothesis is that, besides the necessity to synthesize de novo all the maternal progesterone from cholesterol, it may be more convenient to utilize the fetal PregS. The activities of sulfatase and 3beta-hydroxysteroid dehydrogenase (3beta-HSD) are substantially higher than the activity of cytochrome P450scc, which is rate-limiting for the placental progesterone synthesis from LDL-cholesterol. However, as in the case of progesterone synthesis from maternal LDL-cholesterol, the relative independence of progesterone levels on FZFA activity may be a consequence of substrate saturation of enzymes converting PregS to progesterone. Some of the literature along with our current data (showing no correlation between fetal and maternal progesterone but significant partial correlations between fetal and maternal 20alpha-dihydroprogesterone (Prog20alpha) and between Prog20alpha and progesterone within the maternal blood) indicate that the localization of individual types of 17beta-hydroxysteroid dehydrogenase is responsible for a higher proportion of estrone and progesterone in the fetus, but also a higher proportion of estradiol and Prog20alpha in maternal blood. Type 2 17beta-hydroxysteroid dehydrogenase (17HSD2), which oxidizes estradiol to estrone and Prog20alpha to progesterone, is highly expressed in placental endothelial cells lining the fetal compartment. Alternatively, syncytium, which is directly in contact with maternal blood, produces high amounts of estradiol and Prog20alpha due to the effects of type 1, 5 and 7 17?-hydroxysteroid dehydrogenases (17HSD1, 17HSD5, and 17HSD7, respectively). The proposed mechanisms may serve the following functions: 1) providing substances which may influence the placental production of progesterone and synthesis of neuroprotective steroids in the fetus; and 2) creating hormonal milieu enabling control of the onset of labor.

[Progesterone neuroactive metabolites in human pregnancy]. / Progesteron a jeho neuroaktivní metabolity v mechanismu porodu.

OBJECTIVE: Review of the physiological role of neuroactive and neuroprotective steroids in human pregnancy. DESIGN: A review article. SETTING: Gynecological-Obstetrical Clinic, 1st Medical Faculty, Charles University and General Hospital, Prague. CONCLUSION: Human parturition is a multi-factorial process. Various mechanisms related to the onset of labor were suggested. Estrogens show accelerating increase in late pregnancy, which probably reflect the increasing activity of fetal zone of the fetal adrenal. This zone is stimulated by progressive increase of placental CRH resulting in excessive production of conjugated 3beta-hydroxy-5-en-steroids, which are transported by circulation to placenta and further metabolized to active hormones. Some progesterone metabolites probably participate in pregnancy sustaining via modulation of ligand-gated ion channels in the CNS and periphery. In this review, the question was addressed whether the catabolism of pregnancy sustaining progesterone metabolites accelerate like the estrogen formation.

[Perinatal outcome of twin pregnancies after fertilization in vitro and after spontaneous conception]. / Perinatální výsledky dvojcetných tehotenství po IVF a po spontánní koncepci.

OBJECTIVE: To compare the obstetric outcome of twin pregnancies after IVF with spontaneously conceived twins and thus determine whether IVF twins require greater care. TYPE OF STUDY: A retrospective study. SETTING: The Department of Obstetrics and Gynaecology, 1st Faculty of Medicine of Charles University, Prague. METHODS: Statistical evaluation of obstetric outcome between the group of 46 twin pregnancies after IVF and 85 spontaneously conceived twins. We evaluated the following parameters: signs of abortion and premature delivery, bleeding in pregnancy, premature rupture of membranes, performed cerclage, incidence of praeclampsia, gestational diabetes mellitus and hepatopathy of the mother. Pathological ultrasound findings were also evaluated--disturbances in foetal growth and the amount of amniotic fluid. In these parameters we also evaluated the time of the first signs of their development. Further, we evaluated the type of delivery, the gestational age at delivery, birth weight, birth weight discordance and perinatal mortality. RESULTS: We found statistically significant differences in the method of delivery--more cesarean sections in the IVF group (71.7%) than in spontaneous ones (44.7%). Another difference was the gestational age at which cerclage were performed--earlier in the IVF group (average 22.8 weeks) than in spontaneous ones (average 25.7 weeks). In the other evaluated parameters we did not find any statistically significant differences between the two groups. CONCLUSION: In our retrospective analysis of twin pregnancies, deliveries and neonatal outcome, except for the method of delivery and time of performing cerclage, we did not find any important significant differences between the IVF and spontaneously conceived twins. However, it is necessary to remember the generally worse obstetric outcome of twin compared to singleton pregnancies.

[Significance of the operational test parameters in selection of a diagnostic test for Helicobacter infection]. / Znachenie operatsionnykh kharakteristik testa pri vybore metoda diagnostiki infektsii Helicobacter pylori.

The group of 89 patients was examined, 63 of them suffered by a duodenal ulcerative disease, 11--by gastric ulcerative disease and 15--by chronic gastritis. It was conducted the comparison of the following indices: sensitivity, specificity, relationship of probability and diagnostic efficiency of histological, cytological methods, urease and respiratory tests, method of polymerase chain reaction, qualitative and quantitative definition of antibodies of the class IgG in serum blood to H. pylori by a method of enzyme immunoassay and Western-blot for H. pylori infection diagnostics was carried out. The results show that in choice of a diagnostic method of infection H. pylori it is better to use such characteristics as sensitivity and specificity, which more objectively reflect the diagnostic possibilities of each test.