Freezing temperature effects on photosystem II in Antarctic lichens evaluated by chlorophyll fluorescence

This study explores and compares the limits for photosynthesis in subzero temperatures of six Antarctic lichens: Sphaerophorus globosus, Caloplaca regalis, Umbilicaria antarctica, Pseudephebe minuscula, Parmelia saxatilis and Lecania brialmontii combining linear cooling and chlorophyll fluorescence methods. The results revealed triphasic S-curves in the temperature response of the maximum quantum yield (FV/FM) and effective quantum yield of photosystem II (ΦPSII) for all species. All investigated species showed a high level of cryoresistance with critical temperatures (Tc) below -20 °C. However, record low Tc temperatures have been discovered for L. brialmotii (-54 °C for FV/FM and -40 °C for ΦPSII) and C. regalis (-52 °C for FV/FM and -38 °C for ΦPSII). Additionally, the yield differentials (FV/FM - ΦPSII) in functions of temperature revealed one or two peaks, with the larger one occurring for temperatures below -20 °C for the above-mentioned species. Finally, Kautsky kinetics were measured and compared at different temperatures (20 °C, 10 °C, 0 °C and -10 °C and then -10 °C after 1 h of incubation). This research serves as a foundation for further developing investigations into the biophysical mechanisms by which photosynthesis is carried out at subzero temperatures.

Resistance of Primary Photosynthesis to Photoinhibition in Antarctic Lichen Xanthoria elegans: Photoprotective Mechanisms Activated during a Short Period of High Light Stress

The Antarctic lichen, Xanthoria elegans, in its hydrated state has several physiological mechanisms to cope with high light effects on the photosynthetic processes of its photobionts. We aim to investigate the changes in primary photochemical processes of photosystem II in response to a short-term photoinhibitory treatment. Several chlorophyll a fluorescence techniques: (1) slow Kautsky kinetics supplemented with quenching mechanism analysis; (2) light response curves of photosynthetic electron transport (ETR); and (3) response curves of non-photochemical quenching (NPQ) were used in order to evaluate the phenomenon of photoinhibition of photosynthesis and its consequent recovery. Our findings suggest that X. elegans copes well with short-term high light (HL) stress due to effective photoprotective mechanisms that are activated during the photoinhibitory treatment. The investigations of quenching mechanisms revealed that photoinhibitory quenching (qIt) was a major non-photochemical quenching in HL-treated X. elegans; qIt relaxed rapidly and returned to pre-photoinhibition levels after a 120 min recovery. We conclude that the Antarctic lichen species X. elegans exhibits a high degree of photoinhibition resistance and effective non-photochemical quenching mechanisms. This photoprotective mechanism may help it survive even repeated periods of high light during the early austral summer season, when lichens are moist and physiologically active.

Sulfate supplementation affects nutrient and photosynthetic status of Arabidopsis thaliana and Nicotiana tabacum differently under prolonged exposure to cadmium

Hydroponic experiments were performed to examine the effect of prolonged sulfate limitation combined with cadmium (Cd) exposure in Arabidopsis thaliana and a potential Cd hyperaccumulator, Nicotiana tabacum. Low sulfate treatments (20 and 40 µM MgSO₄) and Cd stress (4 µM CdCl₂) showed adverse effects on morphology, photosynthetic and biochemical parameters and the nutritional status of both species. For example, Cd stress decreased NO₃^- root content under 20 µM MgSO₄ to approximately 50% compared with respective controls. Interestingly, changes in many measured parameters, such as chlorophyll and carotenoid contents, the concentrations of anions, nutrients and Cd, induced by low sulfate supply, Cd exposure or a combination of both factors, were species-specific. Our data showed opposing effects of Cd exposure on Ca, Fe, Mn, Cu and Zn levels in roots of the studied plants. In A. thaliana, levels of glutathione, phytochelatins and glucosinolates demonstrated their distinct involvement in response to sub-optimal growth conditions and Cd stress. In shoot, the levels of phytochelatins and glucosinolates in the organic sulfur fraction were not dependent on sulfate supply under Cd stress. Altogether, our data showed both common and species-specific features of the complex plant response to prolonged sulfate deprivation and/or Cd exposure.

Antarctic Lichens under Long-Term Passive Warming: Species-Specific Photochemical Responses to Desiccation and Heat Shock Treatments

Climate warming in the Antarctic tundra will affect locally dominant cryptogams. Being adapted to low temperatures and freezing, little is known about the response of the polar lichens’ primary photochemistry to warming and desiccation. Since 2008, we have monitored the ecophysiological responses of lichens to the future warming scenario during a long-term warming experiment through open top chambers (OTCs) on Fildes Peninsula. We studied the primary photochemical response (potential Fv/Fm and effective efficiency of photosystem II YPSII) of different lichen taxa and morphotypes under desiccation kinetics and heat shock experiments. As lichens grow slowly, to observe changes during warming we methodologically focused on carbon and nitrogen content as well as on the stable isotope ratios. Endemic Himantormia lugubris showed the strongest effect of long-term warming on primary photochemistry, where PSII activity occurred at a lower %RWC inside the OTCs, in addition to higher Fv/Fm values at 30 °C in the heat shock kinetic treatment. In contrast, Usnea aurantiaco-atra did not show any effect of long-term warming but was active at a thallus RWC lower than 10%. Both Cladonia species were most affected by water stress, with Cladonia aff. gracilis showing no significant differences in primary photochemical responses between the warming and the control but a high sensibility to water deficiency, where, at 60% thallus RWC, the photochemical parameters began to decrease. We detected species-specific responses not only to long-term warming, but also to desiccation. On the other hand, the carbon content did not vary significantly among the species or because of the passive warming treatment. Similarly, the nitrogen content showed non-significant variation; however, the C/N ratio was affected, with the strongest C/N decrease in Cladonia borealis. Our results suggest that Antarctic lichens can tolerate warming and high temperature better than desiccation and that climate change may affect these species if it is associated with a decrease in water availability.

Resistance of Antarctic moss Sanionia uncinata to photoinhibition: chlorophyll fluorescence analysis of samples from the western and eastern coasts of the Antarctic Peninsula

Interspecific differences in sensitivity of the Antarctic moss Sanionia uncinata from King George Island (KGI) and James Ross Island (JRI) to photoinhibitory treatment were studied in laboratory conditions using chlorophyll fluorescence techniques. Slow (Kautsky) and fast (OJIP) kinetics were used for the measurements. Samples were exposed to a short-term (60 min) photoinhibitory treatment (PIT, 2000 μmol·m^-2 ·s^-1 PAR). The photoinhibitory treatment (PIT) led to photoinhibition which was indicated by the decrease in F_V /F_M and Φ_PSII in KGI but not in JRI samples. However, this decrease was small and full recovery was reached 90 min after PIT termination. Non-photochemical quenching (NPQ) was activated during the PIT, and rapidly relaxed during recovery. Early stages of photoinhibition showed a drop in F_V /F_M and Φ_PSII to minimum values within the first 10 s of the PIT, with their subsequent increase apparent within fast (0-5 min PIT) and slow (5-50 min PIT) phases of adjustment. The PIT caused a decrease in the performance index (Pi_Abs), photosynthetic electron transport per reaction centre (RC) (ET₀ /RC). The PIT induced an increase in thermal dissipation per RC (DI₀ /RC), effectivity of thermal dissipation (Phi_D₀ ), absorption per RC (ABS/RC) and trapping rate per RC (TR₀ /RC). In conclusion, PIT led to only slight photoinhibition followed by fast recovery in S. uncinata from KGI and JRI, since F_V /F_M and Φ_PSII returned to pre-photoinhibitory conditions. Therefore, S. uncinata might be considered resistant to photoinhibition even in the wet state. The KGI samples showed higher resistance to photoinhibition than the JRI samples.

Inhibition of Primary Photosynthesis in Desiccating Antarctic Lichens Differing in Their Photobionts, Thallus Morphology, and Spectral Properties

Five macrolichens of different thallus morphology from Antarctica (King George Island) were used for this ecophysiological study. The effect of thallus desiccation on primary photosynthetic processes was examined. We investigated the lichens' responses to the relative water content (RWC) in their thalli during the transition from a wet (RWC of 100%) to a dry state (RWC of 0%). The slow Kautsky kinetics of chlorophyll fluorescence (ChlF) that was recorded during controlled dehydration (RWC decreased from 100 to 0%) and supplemented with a quenching analysis revealed a polyphasic species-specific response of variable fluorescence. The changes in ChlF at a steady state (Fs), potential and effective quantum yields of photosystem II (F_V/F_M, Φ_PSII), and nonphotochemical quenching (NPQ) reflected a desiccation-induced inhibition of the photosynthetic processes. The dehydration-dependent fall in F_V/F_M and Φ_PSII was species-specific, starting at an RWC range of 22-32%. The critical RWC for Φ_PSII was below 5%. The changes indicated the involvement of protective mechanisms in the chloroplastic apparatus of lichen photobionts at RWCs of below 20%. In both the wet and dry states, the spectral reflectance curves (SRC) (wavelength 400-800 nm) and indices (NDVI, PRI) of the studied lichen species were measured. Black Himantormia lugubris showed no difference in the SRCs between wet and dry state. Other lichens showed a higher reflectance in the dry state compared to the wet state. The lichen morphology and anatomy data, together with the ChlF and spectral reflectance data, are discussed in relation to its potential for ecophysiological studies in Antarctic lichens.

Chlorophyll a fluorescence and Raman spectroscopy can monitor activation/deactivation of photosynthesis and carotenoids in Antarctic lichens

Lichens survive harsh weather of Antarctica as well as of other hostile environments worldwide. Therefore, this investigation is important to understand the evolution of life on Earth in relation to their stress tolerance strategy. We have used chlorophyll a fluorescence (ChlF) and Raman spectroscopy, respectively, to monitor the activation/deactivation of photosynthesis and carotenoids in three diverse Antarctic lichens, Dermatocarpon polyphyllizum (DP), Umbilicaria antarctica (UA), and Leptogium puberulum (LP). These lichens, post 4 h or 24 h of hydration, showed differences in their ChlF transients and values of major ChlF parameters, e.g., in the maximum quantum efficiency of PSII photochemistry (F_v/F_m), and yields of fluorescence and heat dissipation (Φ_f,d), of effective quantum efficiency of PSII photochemistry (Φ_PSII) and of non-photochemical quenching (Φ_npq), which may be due to quantitative and/or qualitative differences in the composition of their photobionts. For understanding the kinetics of hydration-induced activation of photosynthesis, we screened Φ_PSII of these lichens and reported its non-linear stimulation on a minute time scale; half of the activation time (t_1/2) was fastest ~4.05 ± 0.29 min for DP, which was followed by 5.46 ± 0.18 min for UA, and 13.95 ± 1.24 min for LP. Upon drying of fully activated lichen thallus, there was a slow decay, in hours, of relative water content (RWC) as well as of F_v/F_m. Raman spectral signatures were different for lichens having algal (in DP and UA) and cyanobacteria (in LP) photobionts, and there was a significant shift in ν₁(C=C) Raman band of carotenoids post 24 h hydration as compared to their value at a dry state or post 4 h of hydration; this shift was decreased, when drying, in DP and LP but not in UA. We conclude that hydration nonlinearly activated photosynthetic apparatus/reactions of these lichens in minute time range but there was a de-novo synthesis of chlorophylls as well as of carotenoids post 24 h. Their dehydration-induced deactivation, however, was comparatively slow, in hours range, and there seemed a degradation of synthesized chlorophylls and carotenoids post dryness. We conclude that in extremophilic lichens, their photosynthetic partners, in particular, possess a complex survival and photoprotective strategy to be successful in the extreme terrestrial environments in Antarctica.

Eco-Physiological Screening of Different Tomato Genotypes in Response to High Temperatures: A Combined Field-to-Laboratory Approach

High temperatures represent a limitation for growth and development of many crop species. Several studies have demonstrated that the yield reduction of tomato under high temperatures and drought is mainly due to a photosynthetic decline. In this paper, a set of 15 tomato genotypes were screened for tolerance to elevated temperatures by cultivating plants under plastic walk-in tunnels. To assess the potential tolerance of tomato genotypes to high temperatures, measurements of chlorophyll fluorescence, pigments content and leaf functional traits have been carried out together with the evaluation of the final yields. Based on the greenhouse trials, a group of eight putative heat-sensitive and heat-tolerant tomato genotypes was selected for laboratory experiments aimed at investigating the effects of short-term high temperatures treatments in controlled conditions. The chlorophyll fluorescence induction kinetics were recorded on detached leaves treated for 60 min at 35 °C or at 45 °C. The last treatment significantly affected the photosystem II (PSII) photochemical efficiency (namely maximum PSII quantum efficiency, F_v/F_m, and quantum yield of PSII electron transport, Φ_PSII) and the non-photochemical quenching (NPQ) in the majority of genotypes. The short-term heat shock treatments also led to significant differences in the shape of the slow Kautsky kinetics and its significant time points (chlorophyll fluorescence levels minimum O, peak P, semi-steady state S, maximum M, terminal steady state T) compared to the control, demonstrating heat shock-induced changes in PSII functionality. Genotypes potentially tolerant to high temperatures have been identified. Our findings support the idea that chlorophyll fluorescence parameters (i.e., Φ_PSII or NPQ) and some leaf functional traits may be used as a tool to detect high temperatures-tolerant tomato cultivars.

Effect of UV-B radiation on the content of UV-B absorbing compounds and photosynthetic parameters in Parmotrema austrosinense from two contrasting habitats

We studied the resistance of Parmotrema austrosinense to UV-B stress. We focused on the effects of a high dose UV-B radiation on the content of chlorophylls, carotenoids and UV-B screening compounds. Photosynthetic parameters were measured by chlorophyll fluorescence (potential and effective quantum yields, photochemical and non-photochemical quenching) and evaluated in control and UV-B-treated lichens. Lichens from two different locations in Cordoba, Argentina, were selected: (i) high altitude and dry plots at (Los Gigantes) and (ii) lowland high salinity plots (Salinas Grandes). UV-B treatment led to a decrease in the content of photosynthetic pigments and UV-B screens (absorbance decrease in 220-350 nm) in the samples from Salinas Grandes, while in Los Gigantes samples, an increase in UV-B screen content was observed. Chlorophyll fluorescence parameters showed a UV-B-induced decline in F_V /F_M , Φ_PSII and qP indicating limitation of primary photosynthetic processes in photosystem II (PSII) of symbiotic alga, more pronounced in Salinas Grandes samples. Protective mechanism of PSII were activated by the UV-B treatment to a higher extent in samples from Salinas Grandes (NPQ 0.48) than in Los Gigantes samples (NPQ 0.26). We concluded that site-related characteristics, and in particular different UV-B radiation regimen, had a strong effect on resistance of the photosynthetic apparatus of P. austrosinense to UV-B radiation.

Laparoscopic cholecystectomy in patient with situs viscerum inversus totalis and gallbladder empyema - a case report

The case report presents the successful performance of laparoscopic cholecystectomy for situs viscerum inversus totalis in a female patient with chronic cholecystitis and cholecystolithiasis and summarizes current knowledge and approaches to this issue. Gallbladder empyema was found perioperatively, which has only been published once in a similar case before. Laparoscopic cholecystectomy in situs viscerum inversus totalis is a safe method to remove the gallbladder. Key words: situs viscerum inversus totalis laparoscopic cholecystectomy gallblader empyema.

Sensitivity of photosynthetic processes to freezing temperature in extremophilic lichens evaluated by linear cooling and chlorophyll fluorescence

Extremophilic lichens and their photosynthesizing photobionts from the cold regions of Earth are adapted to perform photosynthesis at subzero temperatures. To evaluate interspecific differences in the critical temperature for primary photochemical processes of photosynthesis, we exposed lichen thalli of Usnea antarctica, Usnea aurantiaco-atra, and Umbilicaria cylindrica to linear cooling from +20 to -50 °C at a constant rate of 2 °C min^-1. Simultaneously, two chlorophyll fluorescence parameters (F_V/F_M - potential yield of photosynthetic processes in photosystem II, Φ_PSII - effective quantum yield of PS II) evaluating a gradual subzero temperature-induced decline in photosynthetic processes were measured by a modulated fluorometer. For the studied species, the response of F_V/F_M and Φ_PSII to declining temperature showed an S-curve shape. The decline in F_V/F_M and Φ_PSII at low temperatures started at -5 and +5 °C, respectively in the majority of cases. The decline was, however, species-specific. U. aurantiaco-atra showed a constant-rate decline of Φ_PSII from the physiological temperature 20 °C. U. antarctica exhibited the first sign of F_V/F_M decline at -12 °C. The critical temperature related to full inhibition of the photosynthetic processes in PSII (F_V/F_M), was found at -20 °C. However, this occurred at -30 °C for U. cylindrica. In an individual sample, the critical temperature for F_V/F_M was typically lower than for Φ_PSII. The method of linear cooling combined with simultaneous measurements of chlorophyll fluorescence parameters proved to be an efficient tool in the estimation of extremophilic species sensitivity/resistance to freezing.

Changes in spectral reflectance of selected Antarctic and South American lichens caused by dehydration and artificially-induced absence of secondary compounds

Recently, spectral characteristics of lichens are in focus because of increasing number of spectral data applications in remote sensing of treeless polar and alpine regions. Therefore, species-specific spectral reflectance indices are measured in lichen species dominating polar ecosystems. Hydration status of the lichen thalli, as well as the presence of intrathalline secondary metabolites - which are UV-B absorbing compounds - both affects the spectral reflectance curves as well as numeric values of spectral reflectance indices. In the present paper, the reflectance spectra in 380-800 nm was measured in selected lichens to assess the effects of full hydration, and to evaluate the influence of secondary metabolites, they were wash out from lichen thalli with acetone (i.e. acetone rinsing) and then the spectra were also measured. For these experiments, Antarctic (Xanthoria elegans, Leptogium puberulum, Physconia muscigena and Rhizoplaca melanophthalma) and Argentinean lichens from mountain regions (Parmotrema conferendum and Ramalina celastri) were used. Changes in several spectral reflectance indices were evaluated and discussed in relation with hydration status and the absence of secondary metabolites. For the great majority of studied lichens, MCARI (Modified Chlorophyll Absorption in Reflectance Index) was the most effective index to reflect the changes between dry and wet state of thallus.

Features of chlorophyll fluorescence transients can be used to investigate low temperature induced effects on photosystem II of algal lichens from polar regions ( Short Communication )

Chlorophyll fluorescence is an effective tool for investigating characteristics of any photosynthesizing organisms and its responses due to different stressors. Here, we have studied a short-term temperature response on three Antarctic green algal lichen species: Umbilicaria antarctica, Xanthoria elegans, and Rhizoplaca melanophtalma. We measured slow chlorophyll fluorescence transients in these Antarctic lichen species during slowely cooling of thallus temperature from 20°C to 5, 0 and -5°C with 20 minute acclimation at each temperature. The measurements were supplemented with saturation pulses for the analysis of chlorophyll fluorescence parameters: maximum yield of PS II photochemistry (FV/FM), effective quantum yield of PS II photochemistry (FPSII) and quenching parameters. In response to decreasing thallus temperature, we observed species-specific changes in chlorophyll fluorescence parameters as well as in the shape of the chlorophyll fluorescence transients. We propose that species-specific changes in the slow phase of chlorophyll fluorescence transients can be potentially used as indicators of freezing stress in photosynthetic apparatus of lichen algal photobionts.

Comparative analysis of heterogeneity of primary photosynthe-tic processes within fruticose lichen thalli: Preliminary study of interspecific differences ( Short Communication )

Two species of fruticose lichens from different habitats and of distinct color, Usnea antarctica and Stereocaulon vesuvianum, were compared using chlorophyll fluorescence imaging in order to study the distribution of primary photosynthetic processes within the thalli. The thallus of U. antarctica is yellow with black tips: in this species chlorophyll containing cells were mostly located in the middle region of the thallus and the highest PS II efficiency was detected in the middle to basal region, as shown by the FV/FM and ΦPSII values. No chlorophyll fluorescence was detected in the apical part of the thallus, indicating that little or no photosynthesis takes place in these tissues. The lichen S. vesuvianum is homogeneously pale grayish green and chlorophyll containing cells are distributed along the thallus with maximum concentration in the middle region. In S. vesuvianum, the highest PS II efficiency was detected in the apical to middle region of the thallus, while the basal portion was found to have the lowest efficiency of primary photochemical reactions. Quenching analysis data confirmed the uneven patterns of primary photosynthetic processes within the thalli of these fruticose lichens.

[Central venous cannulation under ultrasonographic and fluoroscopic navigation - 2 year experience]

INTRODUCTION

The aim of our study was to evaluate the influence of ultrasonographic and fluoroscopic navigation on the rate of procedural and early complications during central venous cannulation.

MATERIAL AND METHODS

We retrospectively evaluated procedural and early complications in patients who had undergone central venous cannulation under sonographic and fluoroscopic control within a two year period (from January 2010 to December 2011). We studied procedural and early complications (within 24 hours after the procedure). We summarized all cases of pneumothorax, haemothorax and haematoma of soft tissue larger than 5 cm in long axis, and other severe complications e.g. ardiac arrhythmias or hypotension. The set of patients indicated for central venous cannulation included mainly oncological patients who were implanted central venous port systems, and a small group of patients who were cannulated either at the intensive care unit (ICU) or at the department of anesthesiology after unsuccessful blind cannulation. There were three patients cannulated because of transjugular liver biopsy.

RESULTS

We cannulated 165 patients under sonographic control within two years. There were 66 men, the mean age of 58.6 years (20-82) and 99 women, the mean age of 58.3 years (36- 94). We cannulated internal jugular vein 148 times and subclavian vein 17 times. The primary technical success was 100% in our study group. Totally, we had 6 complications (3.6%). Immediatelly after the procedure we observed two pneumothoraxes (1.2%) which did not require chest drainage. We punctured artery wall three times, but without haematoma developement, and after a ten-minute commpression, all procedures were successfully finished. We had serious vagal reaction during the cannulation in one patient. We had no fatal procedural complication in our group. There are significantly fewer complications using jugular approach compared to subclavian one.

CONCLUSION

We conclude that the ultrasonographic central venous cannulation is a very safe method with a low risk of procedural and early complications. There were significantly fewer complications in case of jugular cannulation compared to subclavian approach in our group of patients. Ultrasonographically navigated central venous cannulation should be used more fequently in emergency medicine as well as in case of non-acute central venous cannulation performed a tan intensive care unit or by anesthesiologists.

Interspecific differences in cryoresistance of lichen symbiotic algae of genus Trebouxia assessed by cell viability and chlorophyll fluorescence

Unicellular algae of genus Trebouxia are the most frequent symbiotic photobionts found in lichen species adapted to extreme environments. When lichenised, they cope well with freezing temperature of polar regions, high-mountains environments and were successfully tested in open-space experiments. Trebouxia sp. is considered potential model species for exobiological experiments. The aim of this paper is to evaluate cryoresistence of Trebouxia sp. when isolated from lichen thalli and cultivated on media. In our study, six algal strains were exposed to repeated freezing/thawing cycles. The strains of Trebouxia sp. (freshly isolated from lichen Lasallia pustulata), Trebouxia erici, Trebouxia asymmetrica, Trebouxia glomerata, Trebouxia irregularis, and Trebouxia jamesii from culture collection were cooled from 25 to -40 °C at two different rates. The strains were also shock frozen in liquid nitrogen. After repeated treatment, the strains were inoculated and cultivated on a BBM agar for 7 days. Then, cell viability was assessed as relative share of living cells. Potential quantum yield of photochemical reactions in PS II (F(V)/F(M)), and effective quantum yield of photochemical reactions in PS II (Φ(PSII)) were measured. While the slow cooling rate (0.5 °C min(-1)) did not cause any change in viability, F(V)/F(M), and Φ(PSII), the fast cooling rate (6.0 °C min(-1)) caused species-specific decrease in all parameters. The most pronounced interspecific differences in cryoresistance were found after shock freezing and consequent cultivation. While T. asymmetrica and T. jamesii exhibited low viability of living cells (18.9% and 34.7%) and full suppression of photosynthetic processes, the other strains had viability over 60%, and unaffected values of F(V)/F(M), and Φ(PSII). This indicated a high degree of cryoresistance of T. glomerata, T. erici, T. irregularis and Trebouxia sp. strains. These strains could be used for detailed investigation of underlying physiological mechanisms and as models for astrobiological tests taken in the Earth facilities.

Photoinhibition of photosynthesis in Antarctic lichen Usnea antarctica. I. Light intensity- and light duration-dependent changes in functioning of photosystem II

The paper deals with the differences in sensitivity of Antarctic lichen to photoinhibition. Thalli of Usnea antarctica were collected at the James Ross Island, Antarctica (57°52´57´´W, 63°48´02´´S) and transferred in dry state to the Czech Republic. After rewetting in a laboratory, they were exposed to 2 high light treatments: short-term (30 min), and long-term (6 h). In short-term treatment, the sample were exposed to 1000 and 2000 µmol m-2 s-1 of photosynthetically active radiation (PAR). In long-term experiment, PAR of 300, 600, and 1000 µmol m-2 s-1 were used. Photosynthetic efficiency of U. antarctica thalli was monitored by chlorophyll fluorescence parameters, potential (FV/FM) and actual (FPSII) quantum yield of photochemical processes in photosystem II in particular. In short-term treatments, the F0, FV and FM signals, as well as the values of FV/FM, and FPSII showed light-induced decrease, however substantial recovery after consequent 30 min. in dark. Longer exposition (60 min) to high light led to more pronounced decrease in chlorophyll fluorescence than after 30 min treatment, however dark recovery was faster in the thalli treated before for longer time (60 min). Long-term treatment by high light caused gradual decrease in FV/FM and FPSII with the time of exposition. The extent of the decrease was found light dose-dependent. The time course was biphasic for FV/FM but not for FPSII. The study showed that wet thalli of Usnea antarctica had high capacity of photoprotective mechanisms to cope well either with short- or long-term high light stress. This might be of particular importance in the field at the James Ross Island, particularly at the begining of growing season when melting water is available and, simultaneously, high light stress may happen on fully sunny days.

Interspecific differences in photosynthetic efficiency and spectral reflectance in two Umbilicaria species from Svalbard during controlled desiccation

This study aimed to evaluate the effective photosynthetic quantum yield (FPSII) and the Photochemical Reflectance Index (PRI) for assessment of photosynthetic performance of two Umbilicaria lichens during gradual desiccation of their thalli. U. cylindrica andU. decussata exhibited curvilinear relationship (S-shape curve) of decreasing FPSII values with decreasing water potential (WP) of thalli. During initial phase of desiccation (WP from 0 to -10 MPa), no decrease of FPSII was apparent, further desiccation (WP from -10 to -20 MPa) led to fast FPSII decrease from 0.6 to 0.1 indicating strong inhibition of photosynthetic processes. Critical WP at which photosythetic processes are fully inhibited was found bellow -25 MPa in both lichen species. Photochemical Reflectance Index (PRI) exhibited curvilinear increase with thalli desiccation (decreasing WP). At full thallus hydration, the PRI reached the value of -0.18 in both species. Under strong dehydration (WP from -20 to -30 MPa), however, U. cylindrica showed somewhat lower value (-0.04) than U.decussata (-0.02 MPa). PRI to WP relationship is discussed and compared to existing evidence from higher plants and poikilohydric organisms.

[Percutaneous treatment of symptomatic massive bile ducts stones after previous surgery with biliodigestive anastomosis -- report of three cases]

PURPOSE

Presentation of our own experience with percutaneous treatment of symptomatic bile-duct stones like late complication in patients with biliodigestive anastomosis.

METHOD

Three symptomatic female patients with biliodigestive anastomosis and acutely symptomatic with proven bile-duct stones above anastomosis were treated with initial percutaneous transhepatic drainage and later via percutaneous route using of endoscopic lithotryptor with special technique.

RESULTS

All procedures were successful without complication, the patients are free of biliary symptoms in the long term.

CONCLUSION

Percutaneous removal of bile-duct stones in patients with biliodigestive anastomosis is safe and effective method which can be used as an alternative to surgery.

Climatic and ecological characteristics of deglaciated area of James Ross Island, Antarctica, with a special respect to vegetation cover

Since 2006, year-round measurements of climatic parameters of characteristic ecosystems of James Ross Island, such as (1) coastal vegetation oases, (2) volcanic mesas have been performed by automatic weather stations. Simultaneously, prospection, classification and mapping of vegetation cover have been made annually within the period of Czech Antarctic expeditions lasting from January to March. In this paper, description of the two typical terrestrial ecosystems, characteristics of their microclimate and overview of vegetation cover are given. Daily and monthly means and extreme values of 2-m air temperature, surface temperature and relative humidity are reported for coastal locations and volcanic mesas (300–400 m a.s.l.). Species composition of lichen and moss flora in coastal and mesa locations is characterized and discussed in relation to local topography and microclimate.

[Spontaneous thrombosis of the splenic artery pseudoaneurysms]

The authors demonstrate relatively rare case of evolution and spontaneous thrombosis of the postpancreatitic pseudoaneurysm of the splenic artery, which developed from a pancreatic pseudocyst. The miniinvasive therapeutic approach to the pancreatic pseudoaneurysms is discussed.

[Comparison of coated and bare metallic stents in inoperable carcinomas of the oesophagus and cardia]

INTRODUCTION AND AIM

The authors discuss paliative treatment using coated and bare metallic stents in a prospective randomized study for inoperable oesophageal carcinomas. The aim of this study is to assess the following parameters in both treatment groups: duration of the stents functionality, survival rates, complications rates and histological findings.

METHODS

From 1999 to 2003, the total of 60 patients with oesophageal and cardial carcinomas were randomized. They had either bare (N-31 subjects) or coated (P-29 subjects) stents introduced. The patients were followed-up at one-month intervals.

RESULTS

No statistical differences between the groups were found when the above parameters were assessed.

DISCUSSION

The complications rate depended on the patients survival period in both stent types. Survival rates depended on the disease stage of the local tumorous process and on the individual patient's condition prior to the treatment.

CONCLUSION

The study showed that the metallic selfexpandible stents treatment method may become a widely used paliative procedure in patients with malignant dysphagia, however, it has not proved any differences in complication rates depending on the stent coating.

[Endoscopic solution of iatrogenic lesion of oesophagus]

The case report dissertates upon successful treatment of iatrogenic perforation of distal oesophagus with subcutaneous emphysema, pneumoperitoneum and pneumomediastinum. The endoclips and classic conservative treatment were used in therapy. The patient was treated 3 hours after the injury, no early or late complications related to perforation were noted.

High-light stress and photoprotection in Umbilicaria antarctica monitored by chlorophyll fluorescence imaging and changes in zeaxanthin and glutathione

The effect of high light on spatial distribution of chlorophyll (Chl) fluorescence parameters over a lichen thallus (Umbilicaria antarctica) was investigated by imaging of Chl fluorescence parameters before and after exposure to high light (1500 micro mol m (-2) s (-1), 30 min at 5 degrees C). False colour images of F (V)/F (M) and Phi (II) distribution, taken over thallus with 0.1 mm (2) resolution, showed that maximum F (V)/F (M) and Phi (II) values were located close to the thallus centre. Minimum values were typical for thallus margins. After exposure to high light, a differential response of F (V)/F (M) and Phi (II) was found. The marginal thallus part exhibited a loss of photosynthetic activity, manifested as a lack of Chl fluorescence signal, and close-to-centre parts showed a different extent of F (V)/F (M) and Phi (II) decrease. Subsequent recovery in the dark led to a gradual return of F (V)/F (M) and Phi (II) to their initial values. Fast (30 min) and slow (1 - 22 h) phase of recovery were distinguished, suggesting a sufficient capacity of photoprotective mechanisms in U. antarctica to cope with low-temperature photoinhibition. Glutathione and xanthophyll cycle pigments were analyzed by HPLC. High light led to an increase in oxidized glutathione (GSSG), and a conversion of violaxanthin to zeaxanthin, expressed as their de-epoxidation state (DEPS). The responses of GSSG and DEPS were reversible during subsequent recovery in the dark. GSSG and DEPS were highly correlated to non-photochemical quenching (NPQ), indicating involvement of these antioxidants in the resistance of U. antarctica to high-light stress. Heterogeneity of Chl fluorescence parameters over the thallus and differential response to high light are discussed in relation to thallus anatomy and intrathalline distribution of the symbiotic alga Trebouxia sp.

[Dysphagia in patients with disorders of the nervous system--comparison of a nasogastric tube with percutaneous endoscopic gastrostomy]

Dysphagia is frequently encountered in patients with acute affections of the nervous system (cerebrovascular attacks, craniocerebral injuries) and in chronic nervous diseases (amyotrophic lateral sclerosis, Parkinson s disease, dementia). To these patients enteral nutrition must be administered. If the perspective of dysphagia is short (several days) then nutrition by a nasogastric tube is fully indicated and sufficient. In cases of more prolonged dysphagia and in patients with a long perspective of dysphagia percutaneous endoscopic gastrostomy (PEG) is indicated. Both these methods of enteral nutrition have their advantages and disadvantages which are manifested in different ways in patients with disorders of the nervous system. The authors compared 62 patients hospitalized in the course of 4.5 years at the neurological department who had PEG with 72 patients who had nasogastric tubes and were hospitalized at the neurological intensive care unit in the course of one year. The authors evaluated the different indications for application, the incidence of complications and the advantages and disadvantages of the two methods.

[Indications for percutaneous endoscopic gastrostomy in patients with disorders of the nervous system]

Percutaneous endoscopic gastrostomy (PEG) is an efficient endoscopic method that ensures enteral nutrition for a longer period of time in patients who cannot take food per os. This method is also indicated in patients suffering from disorders of the central or peripheral nervous system which developed suddenly, such as a stroke or craniocerebral injuries, or gradually, such as amyotrophic lateral sclerosis (ALS), dementia, and multiple sclerosis. It has become common practice in the cooperation between neurologists and a gastroenterologists to use PEG in patients hospitalized in a neurological ward with encephalomalacy and haemorrhage, or craniocerebral injuries (after the patient recovers from the acute stage of the disease and is transferred to a neurological ICU), as well as in patients with ALS in a progressive stage. We gradually extend the indications of PEG for other patients with neurological disorders such as patients suffering from dementia, progressive multiple sclerosis, Parkinson's disease, and progressive polyneuropathy. Of 62 patients hospitalized in a neurological ward during a period of 4.5 years, 56 patients suffered from sudden disorders of the nervous system (strokes and craniocerebral injuries) and 6 patients had gradually progressing neurological diseases (ALS, multiple sclerosis, Parkinson's disease, dementia, and polyneuropathy).

[Muscular dystrophies detected by immunophenotyping and genotype analysis (mRNA and DNA)]

Complex diagnosis of muscular dystrophies including clinical, bioptical and molecular genetic approaches has been provided in a limited extent in this country. Our group of neurologists, pathologists and geneticists has examined approximately 240 patients suspected of having muscular dystrophies, mostly coming from Southern and Northern Moravia. The patients were sent to the examination most often from departments of neurology and clinical genetics, and less frequently from departments of internal medicine. According to the final diagnosis, the patients were divided into groups: with dystrophinopathies and carriers of dystrophinopathies (DMD/BMD), merosin deficient form of congenital muscular dystrophy, and Emery-Dreifuss muscular dystrophy including the carriers of this disease. Some relatives of patients with dystrophinopathies were also examined using the methods of segregation analysis. High proportion of the DMD/BMD patients can be detected by the methods of molecular genetics. Analysis of mRNA using RT PCR and PTT enables the detection of deletions, duplications, and point mutations in dystrophin gene and encompasses a larger diagnostic scope in comparison with examinations of DNA level by the multiplex PCR method from the peripheral blood which enables only deletion detections. Immunophenotyping of the dystrophin protein plays an important role especially using antibodies against carboxyterminal (DYS2) and rod domain (DYS1) of dystrophin. Deficient sarcolemmal expression of DYS2 and DYS1 reveals unambiguously a pathological dystrophin. On the other hand, less pronounced deficiencies in dystrophin expression in BMD patients and DMD/BMD carriers may not always be detected in muscle biopsies. In this case, it is necessary to supplement the examination by Western blotting and genotype analysis. The examination of patients with clinically diagnosed muscular dystrophy should start with a muscle biopsy which enables the estimation of presence and degree of structural changes. Application of antibodies against the components of DGC and emerin may reveal a deficiency in expression of these proteins. Immunohistochemical examination completed by Western blotting leads to the subsequent molecular genetic analysis of DNA or mRNA. Secondary deficiencies in expression of other DGC proteins are often revealed in muscle biopsies of dystrophinopathies and this fact must be taken into account in the evaluation of immunohistochemical findings. There is a possibility of replacement of invasive muscle biopsy by skin biopsy or buccal mucosal smears in cases of merosin and emerin deficiencies. Commercially available antibodies against merosin, emerin, calpain and sarcoglycans enable extensive identification and detailed classification of muscular dystrophies. Screening of the patients based on the application of methods described and discussed in this report is the task of the forthcoming period.

[The founding and beginnings of the Institute of Physiology at the Medical School of Comenius University in Bratislava (1924-1939)]

The article deals with the history of foundation and beginnings of the Institute of Physiology of the Medical Faculty of Comenius University in Bratislava. In the school year 1924/25, after the Czechoslovak state university had been founded, the Physiological Institute began its work. The first director was prof. MUDr. Antonín Hanák. Under his leadership the basis of pedagogical and scientific activities in the Institute was established. In the school year 1926/27, Institute moved into the newly built rooms in Sasinková street No 2, where it has been located ever since. Professor Hanák had been working in Bratislava since 1924 till 1930. After his walk-off to Praha, professor MUDr. Vilém Hons became the head of the Institute. In the school year 1936/37 he was elected the dean of the Medical Faculty of Comenius University. He worked in Bratislava till 1939, when he was suspended from the service in the Slovak schools. Both Czech professors founded firm basis of physiology as a subject matter and as a scientific discipline in Slovakia.

Novel dystrophin mutations revealed by analysis of dystrophin mRNA: alternative splicing suppresses the phenotypic effect of a nonsense mutation

The complete dystrophin mRNA sequence has been analyzed in 20 Duchenne muscular dystrophy and Becker muscular dystrophy patients. In 13 cases, deletions in mRNA were detected using reverse transcription-polymerase chain reaction and in another seven cases, point mutations were found using the protein truncation test. Sixteen patients diagnosed with Duchenne muscular dystrophy showed the presence of deletions or of nonsense point mutations. From four patients with the Becker muscular dystrophy phenotype, three cases were associated with deletions conserving the translational frame and one was associated with a nonsense mutation E1110X. In the case of the E1110X mutation, an alternative splicing of dystrophin mRNA (3485-3640del) was detected in this patient which included the E1110X mutation site (nucleotide 3536) and did not change the translation reading frame. Individual nonsense point mutations were characterized by sequence analysis, which showed five novel mutations with respect to those reported in the Cardiff Human Gene Mutation Database http://uwcm.web.cf.ac.uk/uwcm/mg/hgmd0.html and the Leiden muscular dystrophy pages http://www.dmd.nl/.

[Diagnosis and treatment of chronic vaginal candidiasis]

OBJECTIVE OF STUDY

The objective of the study is to determine the optimum diagnostics of vaginal yeast infections and to compare the effects of treatment of these infections by Natamycin with those by Clotrimazol.

TYPE OF STUDY

Prospective comparison of both option of treatment of vaginal infections. NAME AND PLACE OF RESEARCH: Obstetrics and gynaecology department, Brno-Bohunice.

METHODS

30 patients treated with hydrophobe Natamycin and 20 patients treated with hydrophyll Clotrimazol formed a sample of 50 women. Regular checks were made on the 10th and 30th day after the beginning of treatment. Diagnosis was performed by means of native microscopy supplemented by an examination for cultivated yeasts in the culture medium "FUNGI-QUICK". At the same time a microscopic examination of slides stained by Gram and Giems was made.

RESULTS

A correlation between the evaluated native slide and the culture examined thereafter was 96%. Statistical evaluation of the difference of the rate of success of treatment between the two groups by means of the t-test revealed a value of 0.29, the level of probability was 0.05 at N1 = 0.1795 and N2 = 0.2179.

CONCLUSION

Native microscopy is irreplaceable in the diagnosis of vaginal candidosis. No significant differences in the effects of treatment with Natamycin and Clotrimazol were found. On the basis of these results we made some recommendations on the principles of optimum treatment.

Effect of respiration and posture on heart rate variability

The physiological control system of the heart produces a highly complex pattern of cardiac rhythmicity which is reflected in the variability of heart rate. The aim of this study was to analyse the effects of posture and breathing frequency on the cardiac control system by various noninvasive techniques. Seven healthy subjects (24+/-5 years, mean age+/-S.D.) were studied in the supine and sitting positions while breathing spontaneously or at a fixed rate (3, 6, 12, 24, 48, 60 breaths.min(-1)). Time series of instantaneous beat-to-beat heart rates were evaluated by spectral analysis and by the dimensionless approximate entropy parameter. The total spectral power as well as the low (<0.05 Hz) and mid frequency (0.05-0.12 Hz) spectral components were higher in the sitting position. Mean approximate entropy (+/-S.D.) (0.85+/-0.15 in sitting and 0.87+/-0.16 in lying subjects) was unaffected by postural changes or breathing frequencies higher than 6 breaths x min(-1). Analysis in the frequency domain revealed that the activity of the autonomic components controlling heart rate was modified by ventilation and postural changes, whereas approximate entropy, a unique measure of the complexity and integrity of the cardiac control system, was almost unaffected by respiration and posture.

Characterization of two nonsense mutations in the human dystrophin gene

Forty Duchenne muscular dystrophy patients from the province of Moravia in the Czech Republic, who were previously found negative for large deletions in the dystrophin gene, were tested for the presence of point mutations in selected exons. Besides several intron and exon polymorphisms, two cases of nonsense mutations were detected in exon 70, thus causing the loss of the C-terminal domain of dystrophin. One of these, the mutation, S3365X, is newly reported here while the other, R3381X, has been described previously. These mutations, only 16 bp distant from each other, have a very different impact on the mental abilities of the corresponding patients.

[Detection of extensive deletions and duplications in the dystrophin gene]

Dystrophin is a cytoskeletal protein, defects of which results in Duchenne or Becker muscular dystrophy (DMD or BMD). About 70% of all DMD and BMD cases is caused by large deletions and duplications in the dystrophin gene. Therefore, their detection at the DNA and mRNA level is the analysis of the first choice which is undergone by our patients at the molecular level. Methods which have been introduced in our laboratory for this purpose-multiplex PCR and RT-PCR-are subject of this communication.

Distribution of dystrophin gene deletions mapped by multiplex PCR in the Moravian population

Twenty two Duchenne muscular dystrophy (DMD) patients from the province of Moravia, Czech Republic, were tested for the presence of dystrophin gene rearrangements using multiplex polymerase chain reaction (PCR). Using primer pairs for amplification of two promoter regions and 27 exons, 11 patients were found positive for deletions spanning one or more exons. In all these cases, the deletions affected the distal part of the dystrophin gene, beginning from exon 44 but not reaching exon 60.

[Increased bone density in patients with multiple myeloma treated with clodronate]

The indication of bisphosphonates in hypercalcemia is fully accepted, the long term therapy with bisphosphonates is still controversial. The aim of our study was to evaluate the influence of clodronate on the bone density of myeloma patients. Twenty patients were included in the study. Clodronate is administered in the total dose of 3,000 mg, which is delivered in 4-6 hour infusions, 600 mg/day, once in tree 3 months. The effect of clodronate on bone density is evaluated by CT-densitometry in a period of 6 months. At the beginning of May 1994, 15 patients had completed at least two estimations of bone density. The amount of hydroxyapatite in these six months increased in 9 patients, in one of them there was no change and in 4 of them decreasing bone density was detected. The mean bone density before the administration of clodronate was -2.6 SD (standard deviation of European standard of bone density for age and sex). After 6 months of therapy the bone density increased to -2.3 SD. The mean amount of hydroxyapatite in spongiosa was raised from the mean value 32.71 mg/ml before clodronate administration to 38.91 mg/ml after the 6 month treatment period. The mean increase in calciumhydroxyapatite in trabecular bone mass was 6.2 mg. Clodronate contributed to the amelioration of bone pain in the majority of patients, but this effect is difficult to evaluate because of other treatment modalities administered concomitantly. The tolerance of clodronate was good. No impairments of renal function or other adverse effects were observed. Only in 2 patients the decrease in calcium concentration caused slight tetania. Therefore close monitoring of the calcium level is recommended and in the case of its decrease below the physiological level peroral substitution of calcium was started.

[Monoclonal antibodies to dystrophin in biopsy diagnosis of Duchenne and Becker progressive muscular dystrophies]

Immunohistochemical method detecting dystrophin in muscle biopsies was introduced and applied in 121 cases with a large scale of neuromuscular diseases. A monoclonal antibody NCL-DYS 2 (Novocastra) was used for the detection of C-terminal domain of dystrophin. Normal, i.e. sarcolemmal, localization of dystrophin was found in controls, in inactivity atrophy, neurogenic lesions and congenital myopathies. A similar situation except regenerating fibres was found in myositis and progressive muscular dystrophies different from Duchenne (DMD) and Becker (BMD) types, DMD cases showed a complete or nearly complete loss of sarcolemmal reaction product, whereas a partial loss of dystrophin in membrane was found in BMD cases as well as in transmitter females. Fibres splitting during neurogenic and myogenic lesions had dystrophin in newly produced sarcolemmal parts. Sarcolemmal immunoreactivity starting as early as in the 10th-12th week of gestation was found in human fetuses.

[Urologic complications in colorectal carcinoma]

Urological complications of colorectal cancer during surgery of the large bowel are relatively frequent. Fortunately these complications are as a rule transient and recede either spontaneously or after a suitably selected therapeutic procedure. Permanent complications account in our group comprising 311 patients only for a fraction of a per cent. The problem of carcinoma of the colon and rectum and treatment, along with possible complications, is becoming increasingly important in particular in conjunction with an objectively assessed shift of the prevalence of the disease to younger age groups. The group of patients treated in the authors' department on account of colorectal carcinoma during the last five years was evaluated in detail and thus it was possible to detect why different complications developed. This evaluation of all recorded cases was made from the diagnostic aspect as well as with regard to therapeutic possibilities, taking into account the technique of surgical approaches.

[Computer tomography in the diagnosis of neuromuscular diseases in children]

Recently in the literature occasional reports were published on the use of computed tomography (CT) in the diagnosis of neuromuscular diseases. The authors compared in a group of 23 children aged 3 to 15 years the results of clinical, laboratory, electromyographic, bioptic and CT findings on muscles. Only in four children the result of CT did not correlate with the clinical finding because of the incipient stage of the disease with structural changes which were yet only slightly expressed. Consistent with data in the literature it was possible from the CT to differentiate primary myopathies from neurogenic ones. The objective of the work was to prove the assets of the new method in the diagnosis of neuromuscular diseases, in particular in young children who do not cooperate during routine EMG examinations. There CT is an important guide for selective EMG and in particular for aimed bioptic studies which still hold priority in the specification of the disease. In already diagnosed and treated patients it is possible to investigate by means of CT the course of the disease by a non-invasive approach.

[The character of Dr.Vilém Hons. Facts and thoughts on the occasion of a 100 year anniversary]

In the history of the Medical Faculty of the Comenius University in Bratislava there are two personalities with great merits as regards the foundation and development of the Physiology department, both pupils of professor Mares--prof. MUDr. A. Hanák and prof. MUDr. V. Hons. Professor Hons to whom this article is devoted worked in Bratislava from 1930 to 1939. He influenced in an important way the development of the Institute of Physiology in the second decade of its existence and made significant advances in the field of teaching and research. As dean of the medical faculty in 1936-37 and assistant dean in 1937-38 he helped the Faculty to resolve some complicated problems; he opposed the pressure of the undemocratic forces and established and reinforced his relations with students in particular their most important organization--The Society of Czechoslovak Medical Students.

[Pulmonary ventilation and oxygen consumption during passive and active motions in man]

Changes in pulmonary ventilation and O2-consumption were studied during passive and active extension of both crura. The rate and extent of the movements were the same (1Hz). Thirty 21-year-old men (mean weight 72.5 kg, mean height 179 cm) were divided into 3 equal groups, namely controls, with passive movement, and with active movement. The trial consisted of three 11-12 minute periods--initial, period of movement, and recovery. In the control group movements were not performed. Passive movements were carried out by means of a special lever. Ventilation increased at active movements (12.42 +/- 2.731 compared to control values of 8.62 +/- 2.87). Oxygen consumption was increased during active movements (8.4 +/- 2.3 ml.kg-1.min-1 compared to 4.4 +/- 0.6), yet it was reduced during passive movements (3.5 ml compared to control values of 4.4 and initial values of 4.3 ml). The finding is accounted for by the rapid depression of the metabolic efficacy of isolated proprioceptive afferentation as a specific feature of conditioned reflex regulation of metabolism in man.

[Comparison of the degree of chronic gastritis in the resected gastric body with histologic findings in postoperative gastric biopsy]

In resected portions of the stomach we find chronic atrophic gastritis of the corpus only in 10% of the patients with duodenal ulcers, and chronic inflammatory changes are, contrary to patients with a gastric ulcer, less marked. The difference is statistically significant. Consistent with some other authors, we find that great progression of chronic inflammatory changes occurs in patients operated on account of duodenal ulcers in the course of the first three years after operation. From six cases of regression of chronic inflammatory changes after operation, in two cases undetected atrophic gastritis was involved which was present in a severe form in the body of the resected portion beyond the vicinity of the gastric ulcer. According to the author's findings regression of atrophic gastritis is possible. The high score of chronic inflammatory changes in the antrum of gastric resectates (3.54) and in the close vicinity of gastric ulcers (4.0) confirms the frequency of severe antral gastritis in peptic ulceration and the intensity of the focal inflammation in the vicinity of gastric ulcers.

[Reliability of pregnancy diagnosis in sows using direct radioimmunoassay of estrone-sulfate]

The pregnancy diagnosis in sows using direct radioimmunoassay of estrone-sulphate in the blood serum without sample extraction is described. It was found that for the pregnancy diagnosis the period between days 22 and 30 of pregnancy can be used since in this period the estrone-sulphate concentrations in all pregnant sows markedly exceeded those of 64 non-pregnant animals. The estrone-sulphate estimation cannot be used for the pregnancy diagnosis before day 22 and between day 30 and 40 because the estrone-sulphate concentrations in most samples collected in these periods were lower than 4 nmol.l-1.