Katarina Jeremic

Synthesis of Carboxymethyl Starch

Carboxymethyl starch (CMS) was obtained under heterogeneous conditions as a product of the reaction of starch and monochloroacetic acid (MCA) in the presence of sodium hydroxide. The influence of the composition of the reaction mixture, the reaction time and temperature and the type of starch being carboxymethylated on the degree of substitution, DS, and limiting viscosity number, [η], was studied. The reaction temperature influenced the DS values, the highest values of the DS being obtained when the carboxymethylation was performed at 58 °C. Increase of the molar ratio of NaOH to anhydroglycose units leads to an increase in DS, but only to certain extent. The values of the DS and [η] of CMS increased almost linearly with increasing MCA amount in the reaction mixture. The reaction mixture changes caused by adding water to ethanol influenced the DS values of the obtained CMS samples, the maximum DS value being obtained for CMS sample synthesized in ethanol with 25% (v/v) water.

The utility of human epididymal protein 4, cancer antigen 125, and risk for malignancy algorithm in ovarian cancer and endometriosis.

Background In women with pelvic mass, cancer antigen 125 (CA125) had not achieved satisfactory sensitivity and specificity in the detection of ovarian cancer, particularly in patients with underlying endometriosis. The aim of this study was to determine the diagnostic potential of human epididymal protein 4 (HE4), the combination of HE4+CA125, and the Risk of Ovarian Malignancy Algorithm (ROMA) for patients with pelvic mass, particularly in differentiating endometriosis from carcinoma. Methods A prospective cross-sectional study was conducted at the Clinic for Gynecology and Obstetrics, Clinical Center of Serbia. Serum samples were obtained preoperatively from 108 women undergoing surgery for pelvic mass; 29 of them had ovarian carcinoma, and 79 had a nonmalignant ovarian disease (39 with benign tumor, 20 with endometriosis, 20 healthy controls). Sera were analyzed for the levels of HE4 and CA125 and were then compared with the final pathologic results. The diagnostic performance of HE4 and CA125 was estimated using receiver operating characteristic curve and area under the receiver operating characteristic curve. Results The level of HE4 and CA125 was significantly higher among the patients with malignant tumors, compared with patients with nonmalignant disease. At the predefined specificity of 95%, HE4 and CA125 showed sensitivity of 65.5% and 58.6%, respectively, whereas the combination of HE4+CA125 reached 68.9% at the same specificity. Importantly, the level of HE4 did not differ significantly between the patients with endometriosis and with other nonmalignant diseases (which was not the case with CA125). Risk of Ovarian Malignancy Algorithm classified 96% of benign premenopausal cases as at low risk for ovarian cancer. Conclusions HE4 showed satisfactory capability of distinguishing endometriosis from ovarian cancer, which CA125 lacked. The Risk of Ovarian Malignancy Algorithm score proved to be useful in excluding malignant diagnosis in premenopausal women.

Analysis of urologic complications after radical hysterectomy

OBJECTIVE Injuries of the ureter or bladder or development of vesicovaginal and ureterovaginal fistulas are the most serious complications in gynecological surgery. STUDY DESIGN This study included 536 women who underwent radical hysterectomy because of invasive cancer of the cervix uteri. RESULTS During the surgery the ureter was injured in 1.32% of cases, whereas the percentage of bladder injuries was 1.49. In the early postoperative period vesicovaginal or ureterovaginal fistulas appeared in 2.61% and 2.43% of cases, respectively. CONCLUSION The stage of the disease, obesity, diabetes, and postoperative surgical infection acted as predisposing factors of the urinary tract complications.

Conducting polymer materials

Conducting polymers represent a very interesting group of polymer materials Investigation of the synthesis, structure and properties of these materials has been the subject of considerable research efforts in the last twenty years. A short presentating of newer results obtained by investigating of the synthesis, structure and properties of two basic groups of conducting polymers: a) conducting polymers the conductivity of which is the result of their molecular structure, and b) conducting polymer composites (EPC), is given in this paper. The applications and future development of this group of polymer materials is also discussed.

Neonatal outcome in pregnant patients with antiphospholipid syndrome

Abstract Aims: The study aim was to evaluate pregnancy outcomes in patients with antiphospholipid syndrome (APS) and to determine which clinical parameters present risk factors for adverse pregnancy outcomes in these patients. Methods: The study included 55 patients with APS treated at the Clinic for Ob/Gyn, Clinical Center of Serbia, from 2006 to 2012. The control group consisted of 55 healthy pregnant women. Data regarding previous pregnancies and conception method were registered. Immunological and laboratory tests were performed. Pregnancy outcomes, including miscarriage, intrauterine fetal death, hypertensive disorders, diabetes mellitus, phlebothrombosis, fetal growth restriction, premature delivery, delivery method, perinatal asphyxia, respiratory distress syndrome, intraventricular hemorrhage, and necrotizing enterocolitis were followed. Results: The premature delivery rate in APS patients was 31.8%, and pregnancy loss was 18.2%. Significantly more patients with APS had thrombocytopenia, pregnancy losses, intrauterine growth restriction, and perinatal asphyxia compared with the control group. More miscarriages, preterm delivery, lower birth weight, preeclampsia, and IgM anticardiolipin antibody levels significantly correlated with adverse pregnancy outcomes. Although rare, respiratory distress syndrome can also worsen neonatal health status. According to ROC analysis, previous miscarriages correctly explained 66.3% of adverse pregnancy outcome cases. We generated four equations of adverse pregnancy outcome risk factors. Conclusions: The most important prognostic factor for pregnancy outcome in APS patients is the number of previous miscarriages. Using appropriate current therapeutic protocol can enable live birth of a healthy newborn in most cases.

An approach for the improved immobilization of penicillin G acylase onto macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) as a potential industrial biocatalyst.

The use of penicillin G acylase (PGA) covalently linked to insoluble carrier is expected to produce major advances in pharmaceutical processing industry and the enzyme stability enhancement is still a significant challenge. The objective of this study was to improve catalytic performance of the covalently immobilized PGA on a potential industrial carrier, macroporous poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) [poly(GMA‐co‐EGDMA)], by optimizing the copolymerization process and the enzyme attachment procedure. This synthetic copolymer could be a very promising alternative for the development of low‐cost, easy‐to‐prepare, and stable biocatalyst compared to expensive commercially available epoxy carriers such as Eupergit or Sepabeads. The PGA immobilized on poly(GMA‐co‐EGDMA) in the shape of microbeads obtained by suspension copolymerization appeared to have higher activity yield compared to copolymerization in a cast. Optimal conditions for the immobilization of PGA on poly(GMA‐co‐EGDMA) microbeads were 1 mg/mL of PGA in 0.75 mol/L phosphate buffer pH 6.0 at 25°C for 24 h, leading to the active biocatalyst with the specific activity of 252.7 U/g dry beads. Chemical amination of the immobilized PGA could contribute to the enhanced stability of the biocatalyst by inducing secondary interactions between the enzyme and the carrier, ensuring multipoint attachment. The best balance between the activity yield (51.5%), enzyme loading (25.6 mg/g), and stability (stabilization factor 22.2) was achieved for the partially modified PGA.

The thermal degradation kinetics of dextran and pullulan

The effect of molar mass and, in the case of dextran, of the degree of branching on the thermal degradation kinetics of dextran and pullulan was studied in the presence and absence of oxygen. Although the initial mass loss of the dextran samples occurred at higher temperatures than that of the pullulan samples, the overall thermal degradation activation energies were lower for dextran than for pullulan. In the case of dextran the thermal stability was found to decrease with molar mass and degree of branching. The molar mass of pullulan, in the range of 104 to 105 g/mol, appeared to have no significant influence on the thermal characteristics of the samples.ZusammenfassungIn und ohne Gegenwart von Sauerstoff wurde der Einfluß der Molekülmasse, im Falle von Dextran auch der Einfluß des Verzweigungsgrades auf die thermische Zersetzungskinetik von Dextran und Pullulan untersucht. Obwohl der anfängliche Masseverlust der Dextranproben bei höheren Temperaturen eintrat als bei den Pullulanproben, ist die Gesamtaktivierungsenergie der thermischen Zersetzung für Dextran niedriger als für Pullulan. Im Falle von Dextran sinkt die thermische Stabilität mit der Molekülmasse und dem Verzweigungsgrad. Die Molekülmasse von Pullulan scheint im Bereich 104 bis 105 g/mol keinen signifikanten Einfluß auf die thermischen Merkmale der Proben zu haben.

Hypersensitivity to Etoposide in case of metastatic gestational choriocarcinoma.

Etoposide is commonly used in the treatment of a variety of neoplasms. Hypersensitivity reactions to etoposide are infrequently reported and include hypotension, hypertension, flushing, diaphoresis, chest discomfort, dyspnea, bronchospasm and loss of consciousness. We report the case of a 39-year-old woman who experienced acute bronchospasm, tachycardia, hypoxia and hypotension. The symptoms resolved within an hour after administration of intravenous fluids, methylprednisolone, diphenhydramine and oxygen. Subsequently, the patient was given etoposide phosphate without incident.

Clinical outcome of a FIGO stage IV gestational choriocarcinoma

Choriocarcinoma is the most malignant tumor of gestational trophoblastic disease arising from any gestation. It has a tendency toward relapse as well as metastasis. Here, a case of relapsed high-risk choriocarcinoma (FIGO stage IV, WHO score 12) in a 37-year-old female presenting with vaginal bleedings is described. Relapse developed at the site of the surgical scar from hysterectomy that had been performed 2 years earlier. Although the patient was treated with aggressive chemotherapy, she was in a bad general condition and died from infection and liver insufficiency.

Fertility sparing therapy for metastatic gestational trophoblastic disease in young patients.

[1] Lemos NA, Arbo E, Scalco R, Weiler E, Rosa V, Cunha-Filho JS. Decreased antiMüllerian hormone and altered ovarian follicular cohort in infertile patients with mild/minimal endometriosis. Fertil Steril 2008;89(5):1064–8. [2] Corson SL, Gutmann J, Batzer FR, Wallace H, Klein N, Soules MR. Inhibin B as a test of ovarian reserve for infertile women. Hum Reprod 1999;14(11):2818–21. [3] Coric M, Barisic D, Pavicic D, Karadza M, Banovic M. Electrocoagulation versus suture after laparoscopic stripping of ovarian endometriomas assessed by antral follicle count: preliminary results of randomized clinical trial. Arch Gynecol Obstet 2011;283(2):373–8. [4] Hansen KR, Hodnett GM, Knowlton N, Craig LB. Correlation of ovarian reserve tests with histologically determined primordial follicle number. Fertil Steril 2011;95(1): 170–5.