Josip Juras

Some common features of probability distributions for precipitation

SummaryThis paper deals with various transformations commonly employed in order to obtain near normal distributions of precipitation data. In particular, we discuss the properties of the square-root-normal distribution and its relationship to the other commonly used two-parameter distributions. Similarities of different distributions are discussed with the aid of the normal probability graph and the moment-ratio diagram. The latter has the coefficient of variation on the abscissa and the coefficient of skewness on the ordinate. The examination of some historical data sets with the help of these diagrams demonstrates a large variety of forms, but also points to some of their common characteristics.

Fertility preservation options in breast cancer patients

Abstract The purpose of this review is to analyse current options for fertility preservation in young women with breast cancer (BC). Considering an increasing number of BC survivors, owing to improvements in cancer treatment and delaying of childbearing, fertility preservation appears to be an important issue. Current fertility preservation options in BC survivors range from well-established standard techniques to experimental or investigational interventions. Among the standard options, random-start ovarian stimulation protocol represents a new technique, which significantly decreases the total time of the in vitro fertilisation cycle. However, in patients with oestrogen-sensitive tumours, stimulation protocols using aromatase inhibitors are currently preferred over tamoxifen regimens. Cryopreservation of embryos and oocytes are nowadays deemed the most successful techniques for fertility preservation in BC patients. GnRH agonists during chemotherapy represent an experimental method for fertility preservation due to conflicting long-term outcome results regarding its safety and efficacy. Cryopreservation of ovarian tissue, in vitro maturation of immature oocytes and other strategies are considered experimental and should only be offered within the context of a clinical trial. An early pretreatment referral to reproductive endocrinologists and oncologists should be suggested to young BC women at risk of infertility, concerning the risks and benefits of fertility preservation options. Chinese abstract 本文旨在分析目前针对年轻乳腺癌患者生殖力保护的选择方法。由于癌症治疗技术的进步及延迟生育，越来越多的乳腺癌似乎应将其生殖力保护视为一项重要的问题。目前乳腺癌幸存者生殖力保护的选择范围囊括了完善的标准技术及实验性或临床性干预研究。标准方法中，随机启动卵巢刺激方案作为一项新技术可显著降低体外受精周期的总体时长。然而，目前对于雌激素敏感的肿瘤患者，使用芳香化酶抑制剂刺激方案优于接受他莫昔芬治疗。胚胎和卵母细胞冻存被认为是当今乳腺癌患者生殖力保护最成功的技术。由于应用GnRH激动剂的远期疗效尚存争议，且考虑其安全性和有效性，目前将化疗期间应用GnRH激动剂视为患者生殖力保护的实验性方法。卵巢组织冻存、卵母细胞体外成熟技术及其他技术都处于实验性阶段，且仅处于临床试验范围内。对于存在不孕不育风险的年轻乳腺癌患者，在权衡生殖力保护方法利弊后，应给予早期及时转至生殖内分泌专家和肿瘤学专家进行诊治。

Arachidonic and docosahexaenoic acid in the blood of a mother and umbilical vein in diabetic pregnant women

Abstract Objective: The aim of the study was to determine the total concentration of fatty acids (FAs) in the maternal vein serum and in the umbilical vein serum in pregnant women suffering from Type 1 diabetes compared to healthy women. Additional goal was to determine the percentages of arachidonic (AA) and docosahexaenoic acid (DHA) in comparison to the total concentration of FAs. Methods: The study included 63 pregnant women, 32 suffering from Type 1 diabetes and 31 healthy pregnant women. Extraction of total lipids was performed using gas chromatography. Results: There was statistically significant difference in the total FAs concentration in the maternal vein serum and the umbilical vein serum between the two groups. There was a statistically significant higher concentration of total FAs in the maternal and umbilical vein serum of the diabetic group. Higher AA and DHA concentrations were found in the maternal vein serum compared to an umbilical vein serum of the diabetic group. Conclusion: No difference was found in AA and DHA percentages in the maternal or in the umbilical vein serum of diabetic pregnant women. Despite of T1DM, a good metabolic control leads to insignificant changes in the AA and DHA levels in diabetic pregnancy.

Inhibin B for assessment of ovarian reserve after laparoscopic treatment of ovarian endometriomas

Ovarian reserve is reduced in patients with ovarian endometriomas [1]. Healthy ovarian tissue can be removed during laparoscopic stripping, and electrocoagulation further diminishes ovarian reserve. Inhibin B can be used as a clinical test for ovarian reserve in patients undergoing standard assisted reproductive technology [2]. The aim of the present prospective study was to assess serum levels of inhibin B to determine whether laparoscopic stripping of endometriomas diminished ovarian reserve; and to compare the effect on ovarian reserve of suturing and bipolar electrocoagulation performed for hemostasis during the procedure. The studywas conducted fromNovember 1, 2008, to December 28, 2010, at the Zagreb University Hospital Center, Zagreb, Croatia. The institutional Ethics Committee approved the study and all patients provided written informed consent. A total of 121 patients aged 18–35 years (mean, 29.9±4.3 years) with clinical and ultrasound diagnosed unilateral ovarian endometriomas, measuring 30 mm or more, underwent laparoscopic stripping of the cyst wall and were randomized to undergo hemostasis achieved by either ovarian suturing (n=61) or bipolar electrocoagulation (n=60). Serum levels of inhibin B were measured on day 3 of the menstrual cycle before the operation and 3 months after the operation. The G*Power system (www.psycho.uni-duesseldorf.de) was used to determine that a sample size of 119 patients would have 80% power to detect the clinically important difference at α=0.05. The dependent sample t test was used to determine the differences between levels of inhibin B before and after the operation. Pb0.05 was considered statistically significant. For all 121 patients, mean postoperative inhibin B level was significantly lower compared with the mean preoperative level (55.8±27.4 vs 64.4±27.3 pg/mL; P=0.017). Mean postoperative inhibin B level was significantly lower in the group that underwent bipolar electrocoagulation group compared with the group that underwent suturing (50.6±26.0 vs 61.0±28.2 pg/mL; P=0.04; Table 1). Laparoscopic treatment of endometriomas reduces ovarian reserve irrespective of the hemostatic technique used. The present study showed significantly lower postoperative inhibin B levels among women in the bipolar electrocoagulation group compared with the suturing group. These data are consistent with other studies [3,4]. Despite the well-known intracycle variability of inhibin B in serum, it can be used as a marker to assess ovarian reserve. The present study confirms that hemostasis achieved by suturing has fewer adverse effects on ovarian reserve than bipolar electrocoagulation, and is therefore advantageous.

On precipitation monitoring with theoretical statistical distributions

A common practice in meteorological drought monitoring is to transform the observed precipitation amounts to the standardised precipitation index (SPI). Though the gamma distribution is usually employed for this purpose, some other distribution may be used, particularly in regions where zero precipitation amounts are recorded frequently. In this study, two distributions are considered alongside with the gamma distribution: the compound Poisson exponential distribution (CPE) and the square root normal distribution (SRN). They are fitted to monthly precipitation amounts measured at 24 stations in Croatia in the 55-year-long period (1961–2015). At five stations, long-term series (1901–2015) are available and they have been used for a more detailed investigation. The accommodation of the theoretical distributions to empirical ones is tested by comparison of the corresponding empirical and theoretical ratios of the skewness and the coefficient of variation. Furthermore, following the common approach to precipitation monitoring (CLIMAT reports), the comparison of the empirical and theoretical quintiles in the two periods (1961–1990 and 1991–2015) is examined. The results from the present study reveal that it would be more appropriate to implement theoretical distributions in such climate reports, since they provide better evaluation for monitoring purposes than the current empirical distribution. Nevertheless, deciding on an optimal theoretical distribution for different climate regimes and for different time periods is not easy to accomplish. With regard to Croatian stations (covering different climate regimes), the CPE or SRN distribution could also be the right choice in the climatological practice, in addition to the gamma distribution.

SUVREMENE PREVENCIJSKE STRATEGIJE PORASTA PREDOVULACIJSKOG PROGESTERONA TIJEKOM STIMULACIJE JAJNIKA U POSTUPKU IZVANTJELESNE OPLODNJE

The purpose of this review is to present contemporary measures for preventing the increase in preovulatory progesterone (P) and its adverse effects on ovarian stimulation in in vitro fertilization (IVF). For the last 20 years, the increase of preovulatory P has been a topic of numerous discussions because its role is not fully understood in terms of its impact on pregnancy outcome after IVF. Some studies failed to establish a connection between the preovulatory P increase and successful IVF outcome regardless of the level of P, while, conversely, most other studies have reported on adverse effects of elevated P concentrations. Current strategies to prevent the increase in preovulatory P include an individualized approach with the use of mild stimulation protocols and early application of human chorionic gonadotropin for ovulation induction among good responders, delay in the transfer of fresh embryos from 3rd to 5th day, and cryopreservation of all embryos with the thawed embryo transfer in the natural cycle. Nevertheless, further studies are needed to confirm the current preventive methods or enable the application of new strategies in order to lower or eliminate the detrimental effects of preovulatory P rise during ovarian stimulation in IVF.

Prevalence, treatment and control of hypertension in a Croatian endemic nephropathy area.

Background: Hypertension is not considered to be a characteristic of endemic nephropathy (EN). Recent observations suggested that it might be more prevalent than it was reported before. Aim: The aim of our study was to analyze prevalence, treatment and control of hypertension in a Croatian endemic area. Methods: In the present cross-sectional study, 1,602 farmers were enrolled, 1,246 from EN and 356 from control villages. Epidemiological and medical histories were taken and clinical and laboratory examinations performed for kidney function. Blood pressure was measured following the ESH/ESC guidelines. Results: The prevalence of hypertension in EN villages was higher than in control (50.8 vs. 46.5%, p = 0.005). There was no difference in overall treatment, control of all and treated hypertensives between the villages. In all villages, women were treated more than men (EN 41.6 vs. 28.4%, p < 0.001; control 46.4 vs. 27.3%, p < 0.001), but better control of treated was achieved in men (EN 24.7 vs. 17.4%, p = 0.002; control 29.6 vs. 15.5%, p = 0.002). Women had lower income and level of education than men (p < 0.01). Conclusion: Hypertension is highly prevalent in endemic villages. In all villages, men had better blood pressure control despite being treated less. This finding could be explained by poorer education and income in women.