Experimental harvesting of wetland plants to evaluate trade-offs between reducing methane emissions and removing nutrients accumulated to the biomass in constructed wetlands.

Constructed wetlands built for water treatment often need biomass harvesting to remove nutrients from the system. Usually harvesting is done during the peak growing season to maximize the amount of nutrients removed from the system. This, however, can create huge methane fluxes that escape from plant tissues to the atmosphere. We used manual chambers and eddy covariance measurements to analyze the increase in methane emissions due to the harvesting of two common wetland species, Typha spp. and Schoenoplectus spp., in two climatically different constructed wetlands in Estonia and California. In addition, we determined the biomass nutrient and carbon concentrations from harvested biomass. We found that harvesting during the summer season, e.g. June and August, resulted in a significant release of methane at both sites. At the California site, baseline median methane emissions were 217.6 nmol m-2 s-1, and harvesting resulted in increases to 395.4 nmol m-2 s-1 that decreased to baseline emission within three days. Footprint modeling demonstrated that the emission increases measured by eddy covariance were dominated by contributions from the cut area to the total footprint signal. At the Estonian site, harvesting resulted in methane increases of 15.9 nmol m-2 s-1 to 110.4 nmol m-2 s-1 in August. However, in September and October the emission was significantly lower. Plant biomass analyses showed clear temporal dynamics in terms of nutrient concentration, being highest in summer and lowest in winter. Our experiments indicate that the optimal time for aboveground biomass harvesting is at the end of the growing season before nutrient translocation to belowground plant structures begins coinciding with lowest methane emissions. Therefore, strategic planning of the harvest timing may help reduce greenhouse gas emissions from managed wetlands and thus improve their multi-faceted ecological benefit.

[Transplacental transfer, tissue localization and morphological study of the rabbit placenta after the administration of pentacaine]. / Transplacentárny prechod, tkanivová lokalizácia a morfologická stúdia placenty králika po podaní pentakaínu.

On day 29 of gravidity, the New Zealand white breed rabbits were intravenously administered 3H-pentacaine (0.5 mg.kg-1), a new local anaesthetic agent with anti-ulcerous effect in order to study the distribution in pregnant females. Transplacental passage and a relatively homogenous distribution of unchanged pentacaine were found in the organs of females with the largest accumulation in the lungs. Pentacaine is distributed in the same manner in the fetal organs as in the organs of the mother, but the levels in the foetuses were significantly lower. A morphological study of the rabbit placenta on day 29 of gravidity after the doses of 1, 10 and 50 mg.kg-1 of pentacaine did not show any pathological changes.

Endoscopic gastroduodenal polypectomy.

The authors performed a total of 288 successful endoscopic gastroduodenal polypectomy procedures in 129 patients. Drawing on literary data and the results of follow-up of their own patients, they regard endoscopic gastroduodenal polypectomy as a successful and relatively low-risk method for secondary prevention of gastric cancer. Recurrence of adenomas, with malignant degeneration in 6-75%, was noted, only in the first year after primary polypectomy, in 8% of patients. Four percent of patients after adenoma polypectomy developed gastric carcinoma. Removal of gastroduodenal adenomas by endoscopy represents a final therapeutic procedure significantly reducing the possibility of these originally benign variants transforming into malignant ones. Even polyps smaller than 10 mm in diameter may be adenomas possessing a rather high malignant potential. The authors regard endoscopic polypectomy of hyperplastic polyps as a justified procedure since the literary data compiled and their own experience suggest polyp susceptibility to development of dysplasia. While this tendency gets manifest only rarely, it would be medically wrong to dismiss it as negligible. In case of removal of an early polypoid gastric carcinoma, endoscopic polypectomy is a therapeutic procedure only in clearly defined and histologically well classified cases. In other cases involving prominence of the gastroduodenal mucosa, it is an invaluable diagnostic method whose benefit is that it removes an entire polyp for histologic examination.

Decreased apolipoprotein levels in women with hyperprolactinemia related to increased estradiol level: effect of hepatic lesion?

In 3 groups of women (1. with pathological hyperprolactinemia, but low estradiol level--19 patients; 2. with pathological hyperprolactinemia, but high estradiol level--17 patients; 3. 16 healthy control women) the level of prolactin, estradiol, cortisol, total cholesterol, triglycerides and apolipoproteins A-I, A-II and B in serum was estimated together with routine clinical examination. In both hyperprolactinemic groups a significant decrease of apolipoprotein A-I and A-II was found, while in the group with high estradiol also a significant decrease of apolipoprotein B was observed. It is suggested that the increased level of prolactin results in an impairment of apolipoprotein biosynthesis and, in addition, in a group with high estradiol level also a lesion of liver function might occur which results in its decreased degradation.

Malignant tumors and embolizing paraneoplastic endocarditis.

A group of 4495 autopsied patients was evaluated. In 1011 (22.5%) of them various malignancies were found. In 20 of these cancer patients (2%) also a nonbacterial verrucous endocarditis was observed. The most serious complication of this paraneoplastic syndrome was central arterial embolization resulting in cerebral and myocardial infarctions. In our group this was observed in 12 patients (60%), in 9 cases of them infarction was the immediate cause of death. Fatal complications due to central embolization were seen also in 3 patients who had a malignant disease without symptoms of generalization. The most frequent tumors observed among the autopsied patients were adenocarcinomas of the digestive tract (40%). In the group of revealed tumors adenocarcinomas clearly prevailed (70%) in 10 cases (50%) also mucin production could be detected.