Methodological challenges in using human umbilical artery as a model for in vitro studies.

NEW FINDINGS: What is the central question of this study? What are the biggest challenges in performing in vitro studies on isolated human umbilical arteries? What is the main finding and its importance? The protocols presented in this study indicate some potential outcomes important for interpretation of the vascular responsivities of human umbilical arteries and could be useful for planning future in vitro studies with human umbilical arteries. ABSTRACT: Human umbilical artery (HUA) preparations are of particular importance for in vitro studies on isolated blood vessels because their sampling is not risky for the patient, and they can provide the closest possible impression of changes related to the uteroplacental circulation during pre-eclampsia. Using organ bath techniques, useful experimental protocols are provided for measuring some pathophysiological phenomena in the vascular responses of HUAs. Several vasoconstrictors (serotonin, prostaglandin F and phenylephrine) and vasodilators (acetylcholine and minoxidil) were seleted for determination of their vasoactivity in HUAs. The role of L-type voltage-operated calcium channels and different types of potassium channels (KATP , BKCa and KV ) were assessed, as was the impact of homocysteine. Serotonin was confirmed to be the most potent vasoconstrictor, while acetylcholine and phenylephrine caused variability in the relaxation and contraction response of HUA, respectively. The observed increase in serotonin-induced contraction and a decrease in minoxidil-induced relaxation in the presence of homocysteine suggested its procontractile effect on HUA preparations. Using selective blockers, it was determined that KATP and KV channels participate in the minoxidil-induced relaxation, while L-type voltage-dependent Ca2+  channels play an important role in the serotonin-induced contraction. The presented protocols reveal some of the methodological challenges related to HUA preparations and indicate potential outcomes in interpreting the vascular effects of the investigated substances, both in physiological conditions and in the homocysteine-induced pre-eclampsia model.

Pomegranate Peel Extract Attenuates Isoprenaline-Induced Takotsubo-like Myocardial Injury in Rats.

Takotsubo syndrome (TTS) is an acute heart failure syndrome characterised by catecholamine-induced oxidative tissue damage. Punica granatum, a fruit-bearing tree, is known to have high polyphenolic content and has been proven to be a potent antioxidant. This study aimed to investigate the effects of pomegranate peel extract (PoPEx) pre-treatment on isoprenaline-induced takotsubo-like myocardial injury in rats. Male Wistar rats were randomised into four groups. Animals in the PoPEx(P) and PoPEx + isoprenaline group (P + I) were pre-treated for 7 days with 100 mg/kg/day of PoPEx. On the sixth and the seventh day, TTS-like syndrome was induced in rats from the isoprenaline(I) and P + I groups by administering 85 mg/kg/day of isoprenaline. PoPEx pre-treatment led to the elevation of superoxide dismutase and catalase (p < 0.05), reduced glutathione (p < 0.001) levels, decreased the thiobarbituric acid reactive substances (p < 0.001), H2O2, O2- (p < 0.05), and NO2- (p < 0.001), in the P + I group, when compared to the I group. In addition, a significant reduction in the levels of cardiac damage markers, as well as a reduction in the extent of cardiac damage, was found. In conclusion, PoPEx pre-treatment significantly attenuated the isoprenaline-induced myocardial damage, primarily via the preservation of endogenous antioxidant capacity in the rat model of takotsubo-like cardiomyopathy.

Vasorelaxant effect of monoterpene carvacrol on isolated human umbilical artery.

Carvacrol (CRV) is the main compound of essential oils extracted primarily from Thymus and Origanum species. Its various biological activities were confirmed: antioxidant, anti-inflammatory, antibacterial, antifungal, anti-tumour, antinematodal, and vasorelaxant action. Although vasodilation mediated by CRV was previously described, the exact mechanism of its action has not yet been established. Hence, the aim of this study was to investigate CRV vasoactivity on human umbilical arteries (HUA) and the different pathways involved in its mechanism of action using the tissue bath methodology. CRV caused a significant decrease in vascular tension of 5-HT-pre-contracted umbilical arteries, with EC50 of 442.13 ± 33.8 µmol/L (mean ± standard error of the mean-SEM). At 300 µmol/L, CRV shifted downward the 5-HT concentration-response curve with a statistical significance of p < 0.001 obtained for the four highest concentrations. At a concentration of 1 mmol/L, CRV completely abolished BaCl2-induced contraction in Ca2+-free Krebs-Ringer bicarbonate solution and the BAY K 8644-induced contraction in Krebs-Ringer bicarbonate solution (p < 0.001). Isopentenyl pyrophosphate, the antagonist of TRPV3 channel, was able to decrease the efficacy of CRV (p < 0.001). The blocking of L-type Ca2+ channels on smooth muscle cells is the most probable mechanism of CRV-induced vasorelaxation. However, the role of TRPV3 channels in CRV-induced vasodilation of HUA cannot be excluded either.

Prevalence of Cigarette Smoking and Influence of Associated Factors among Students of the University of Banja Luka: A Cross-Sectional Study.

Background and Objectives: Cigarette smoking among the youth population has increased significantly in developing countries, including Bosnia and Herzegovina. However, no extant literature assesses the prevalence of tobacco use, nor identifies factors associated with smoking. This study determined the prevalence of cigarette smoking among a specific cohort of students and assessed factors related to tobacco use in this population. Materials and Methods: This cross-sectional study included 1200 students at all faculties of Banja Luka University. Data were collected from questionnaires adapted from the Global Youth Tobacco Survey (GYTS) and the Global Health Professional Student Survey (GHPSS) standardized questionnaires and were analyzed using descriptive statistics, Pearson's χ2 test, and logistic regression. Results: When the prevalence of cigarette smoking within the last thirty days was recorded, we found that 34.1% of students smoked within this period. Nearly three-quarters (74.9%) of the student population had smoked or experimented with cigarette smoking. However, medical students were 27.2% less likely to smoke than their counterparts from other faculties. Overall, 87% of all students were aware of the harmful effects of cigarette smoking, 79% were aware of the harmful effects of secondhand smoke, and 65% reported that it was difficult to quit. Increased spending of personal money was associated with a higher probability of smoking, while exposure to secondhand smoke increased the odds of smoking by 62%. Conclusion: Policies, strategies, and action plans should be introduced in order to reduce the prevalence of smoking among university students and to create a smoke-free environment at the various universities involved.

KPC-Producing Klebsiella pneumoniae Isolates in Croatia: A Nationwide Survey.

BACKGROUND: In the last few years, Klebsiella pneumoniae strains producing K. pneumoniae carbapenemase (KPC) enzymes have emerged as important multidrug-resistant pathogens in hospitalized patients. This report describes KPC-producing isolates collected through the Croatian antimicrobial resistance surveillance program in the early stage of their dissemination in Croatia. MATERIALS AND METHODS: Forty-eight KPC-producing K. pneumoniae isolates, collected during a period from February 2011 to August 2013, were analyzed in this study. Antimicrobial susceptibility profiles were determined using disk diffusion and E-test. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used for epidemiological analysis. Identification of ß-lactamase genes and associated antibiotic resistance mechanisms was performed by polymerase chain reaction and positive products were sequenced. Localization of blaKPC was investigated by S1 PFGE and Southern hybridization. RESULTS: Of 40 participating centers in Croatia, KPC isolates were recorded in 9 of them. They all had multidrug-resistant phenotype, but showed varying levels of resistance to carbapenems. All isolates displayed ST258, and PFGE showed that all but one were closely related. All isolates harbored blaKPC-2. Isolate with a unique PFGE pattern produced TEM-1, while others produced TEM-116. All isolates harbored blaSHV-11, but were negative for blaCTX-M and blaAmpC genes. All isolates contain one KPC-harboring plasmid, ranging in size from ∼60 to ∼210 kb, characterized as FIIs and IncR. CONCLUSION: This report describes that the early stage of KPC-producing K. pneumoniae dissemination in Croatia is associated with a prolific PFGE type belonging to ST258. So far, the spread of an outbreak strain is limited to the northwest region of the country.

Periodontal disease increases risk for chronic obstructive pulmonary disease.

The aim of this study was to explore whether a periodontal disease could be a risk indicator for a chronic obstructive pulmonary disease (COPD). The examined group comprised 93 patients with COPD (mean age 65.8 years). The control group comprised 43 systemically healthy individuals (mean age 62.1 years). Respiratory and periodontal conditions were examined in both groups. COPB subjects had significantly worse periodontal conditions than controls (p < 0.05) with regard to each parameter of periodontal condition, except for gingival inflammation. COPD patients had higher Plaque Index than control patients (82.84 +/- 22.81 vs. 57.15 +/- 26.96; p < 0.001), higher periodontal depth (3.02 +/- 0.92 vs. 2.57 +/- 0.79 mm; p = 0.007), higher gingival recession (1.97 +/- 1.09 vs. 0.91 +/- 0.79 mm; p < 0.001), and higher mean clinical attachment loss (CAL) (4.12 +/- 1.74 vs. 2.91 +/- 1.27 mm; p < 0.001). Multiple logistic regression model, after controlling for other risk indicators, showed that periodontal disease, presented as CAL > or = 4 mm at > or = 60% sites, was associated with odds ratio of 3.2 (95% CI 1.0-9.8) for the COPB group. Data suggest that periodontal disease could be a risk indicator for COPD.