Regulation of sarcoendoplasmic reticulum Ca2+-ATPase (SERCA) in turtle muscle and liver during acute exposure to anoxia.

The freshwater turtle Trachemys scripta elegans naturally tolerates extended periods of anoxia during winter hibernation at the bottom of ice-locked ponds. Survival in this anoxic state is facilitated by a profound depression of metabolic rate. As calcium levels are known to be elevated in anoxic turtles, and ion pumping is an ATP-expensive process, we proposed that activity of the sarcoendoplasmic reticulum Ca(2+)-ATPase (SERCA) would be reduced in muscle and liver of T. s. elegans during acute (up to 20 h) exposure to anoxia. SERCA activity decreased approximately 30% in liver and approximately 40% in muscle after 1 h anoxia exposure and was approximately 50% lower after 20 h of anoxia exposure in both tissues, even though SERCA protein levels did not change. SERCA kinetic parameters (increased substrate K(m) values, increased Arrhenius activation energy) were indicative of a less active enzyme form under anoxic conditions. Interestingly, the less active SERCA in anoxic turtles featured greater stability than the enzyme from normoxic animals as determined by both kinetic analysis (effect of low pH and low temperatures on K(m) MgATP) and conformational resistance to urea denaturation. The quick time course of deactivation and the stable changes in kinetic parameters that resulted suggested that SERCA was regulated by a post-translational mechanism. In vitro experiments indicated that SERCA activity could be blunted by protein phosphorylation and enhanced by dephosphorylation in a tissue-specific manner.

Magnetic field gradients in solid state magic angle spinning NMR.

Magnetic field gradients have proven useful in NMR for coherence pathway selection, diffusion studies, and imaging. Recently they have been combined with magic angle spinning to permit high-resolution measurements of semi-solids, where magic angle spinning averages any residual dipolar couplings and local variations in the bulk magnetic susceptibility. Here we show the first examples of coherence pathway selection by gradients in dipolar coupled solids. When the gradient evolution competes with dipolar evolution the experiment design must take into account both the strength of the dipolar couplings and the means to refocus it. Examples of both homonuclear and heteronuclear experiments are shown in which gradients have been used to eliminate the need for phase cycling.

[The role of eye-like spots of parasitic leeches (Hirudinea, Piscicolidae) in searching for fish-hosts]. / Rola plamek oczoksztaltnych u pijawek pasozytniczych (Hirudinea, Piscicolidae) w odszukiwaniu ryb-zywicieli.

Piscicola geometra (L.), Piscicola respirans Troschel, 1850, and Caspiobdella fadejewi (Epshtein, 1968) find their hosts (fishes) by reacting to their shadow. Eye-like spots whose number ranges from 8 to 16 depending on a species, located on the posterior sucker are the main receptors perceiving the decrease in light intensity and thus enabling an immedaite reaction to the host's shadow. They are distributed on the perimeter of the sucker, are absent only from the section that is constantly shaded by the leech body. Experiments with a simulated shadow reveled considerable differences in the threshold light doses between the studied species: P. geometra - 12 lux, P. resprans - 4 lux and C. fadejewi - 2.5 lux. Below these values the leeches do not perceive the decrease in light intensity and do not make host-searching movements. The smallest decreases in light intensity, at which the leeches still make host-searching movement, are: P. geometra - 5 lux, P. resprans - 2 lux, and C. fadejewi- 1.5 lux. In case of P. respirans and C. fadejewi such small decreases in light intensity (2 - 1.5 lux) may be caused only by small fishes which, according to the results of the experiment, should not be infested. This is confirmed by field observations - small fishes are mostly free from parasites. Large fishes (casting a large shadow) have much more numerous leeches.

Piscicola brylinskae, a new leech species from the Netherlands (Hirudinea: Piscicolidae).

Piscicola brylinskae n. sp. is described from the lake Vechten in the village of Bunnik (Prov. Utrecht), The Netherlands. The characteristic features of this leeches allow to conclude that this species is a member of the subfamily Piscicolinae, probably a parasite of fish.

[Leeches (Hirudinea: Piscicolidae and Glossiphonidae) infecting lake fish in the Ukiel, Warniak and Wulpinskie. Preliminary study]. / Pijawki pasozytujace na rybach (Hirudinea: Piscicolidae i Glossiphonidae) w jeziorach Ukiel, Warniak i Wulpinskie. Badania wstepne.

The aim of the study was to determine leeches found on the lake fishes. From the lake Ukiel, 213 roaches (R. rutilus) and from the lake Wulpinskie 202 were examined between Nov. 1988 and Dec. 1999. From the Warniak 258 roaches and 9 tenches (Tinca tinca) were examined between May 1998 and Nov. 1999. Warniak on roach (R. rutilus) 4 Piscicola geometra and Hemiclepis marginata on the fish body were found, tench (Tinca tinca) P. geometra were found on gills. Ukiel on roach Piscicola pojmanskae on gills were found. Wulpinskie on roach P. pojmanskae and Piscicola sp. as well as 2 Caspiobdella fadejewi on gills were found. Prevalence and intensity of fish infection with leeches was low in all lakes. C. fadejewi and P. pojmanskae are the first recorded on the lake fishes. Further investigations are necessary since they can result in informations concerning inhabitation of new microhabitants with P. geometra gills.

Position, structure and function of pulsatile vesicles in parasitic leeches Codonobdella truncata Grube, 1873 and Caspiobdella fadejewi Epshtein, 1961 (Hirudinea, Piscicolidae, Piscicolinae).

Histological analysis of frontal section through the body of parasitic leeches (Codonobdella truncata, Caspiobdella fadejewi) of the subfamily Piscicolinae revealed the presence of 11 pairs of subepidermal pulsatile vesicles. The vesicles of C. truncata are poorly visible on the body surface, contrary to those of C. fadejewi, which results from the fact that in the former species the vesicles are located in a layer of subepidermal connective tissue thicker (82. 82 microm) than in C. fadejewi (20.6 microm). In the studied species the pulsatile vesicles have a club-like shape, are surronded by a muscular tunicle and connected with a short canal that penetrates the body wall. Some of the sections show that the vesicles are divided in two chambers (lower and upper) with an incomplete membrane.

Trichodina pediculus Ehrenberg, 1838 in roach Rutilus rutilus (L.), metric and meristic data.

During the parasitological studies in Dgal Wielki Lake 32 specimens of Trichodina pediculus were collected from roaches (Rutilus rutilus). T. pediculus were subjected to the metric and meristic measurements. High correlation factors significance was obtained between the following data: body diameter and adhesive disc diameter with border membrane, adhesive disc diameter without border membrane, denticulate ring diameter, height of denticle. However no correlation significance between body diameter and number of denticles was found.

[Parasites leech Batracobdelloides moogi (Nesemann & Csanyi, 1995) (Hirudinea, Glossiphoniidae vaillant, 1850) of Polish fauna?]. / Pasozytnicza pijawka Batracobdelloides moogi (Nesemann & Csanyi, 1995) (Hirudinea, Glossiphoniidae Vaillant, 1850) W faunie Polski?

In the light of recent studies (NESEMANN and CSANYI 1995) on the genus Batracobdella (VIRGUIER 1879) Batracobdella paludosa (CARENA 1824)--a component of the Polish fauna--is actually Batracobdelloides moogi (NESEMANN and CSANYI 1995).

Occurrence of Trichodina pediculus Ehrenberg, 1838 in Dgal Wielki Lake.

Parasitological investigation were performed in Dgal Wielki, occurrence T. pediculus Ehrenberg 1838 on the roach gills were recorded. On the 277 examined roach in 9 roach specimens T. pediculus were found. Prevalence of roach infection was 3.25%, mean intensity 3.5 and abundance 0.11 parasite per number of fish examined. T. pediculus were found on fish in May and June.

Variability of the reproductive system of Piscicola fasciata (Kollar, 1842 (Hirudinea, Piscicolidae).

The studies on the reproductive system of P. fasciata were based on 43 specimens. Two main types of the reproductive system can be distinguished in the studied population. Two types of reproductive system were the most frequent (20.93% each): with symmetrical ejaculatory ducts without a loop and symmetrical seminal vesicles reaching the end of the first pair of testes, situated next to the testes (adult individuals) (fig. 23) and with symmetrical ejaculatory ducts without a loop (fig. 21) and symmetrical poorly developed seminal vesicles situated asymmetrically anterior to the first pair of testes (juvenile individuals). The structure of the reproductive system corresponding with the description of the type specimen (BRUMPT, 1900) was not observed in the studied population.

Variability of the reproductive system of Piscicola respirans (Troschel, 1850) (Hirudinea, Piscicolidae).

The studies on the reproductive system of P. respirans, based on 115 specimens, have revealed its considerable variability. Two main types of the system can be distinguished: 1) ovaries reaching the first pair of testes, ejaculatory ducts symmetrical, no seminal vesicles (juvenile individuals), 2) ovaries reaching the first pair of testes, ejaculatory ducts symmetrical, seminal vesicles reaching the ends of ovaries (adults individuals). The structure of the reproductive system is correlated with the individual size and age. Because the reproductive system of P. respirans as described by BRUMPT (1900) and SKET (1968) based on type specimens designated by them, is found only in a small fraction (c. 4-8%) of specimens, a redescription of the species is necessary, best based on a neotype series.

Glossiphoniidae Vaillant, 1850 (Hirudinea) of Poland--systematics and perspectives of studies.

Taxonomic and biological-ecological information as well as literature pertaining to the eleven Polish representatives of glossiphoniid leeches are summarized. Taxonomic status of many species is unclear, and data on their life histories are often fragmentary. The existence of several different conflicting systems of glossiphoniid classification indicates that the taxonomical value of characters is unclear. The family requires a thorough modern revision. A new generic-level classification of the family is needed. Data on behaviour and life cycles of mostspecies should be supplemented; anatomical variation and differences between the purported forms of glossiphoniid species should be re-examined. A detailed study on the life cycles and variation of the Polish members of the Glossiphoniidae would provide new and valuable data and would allow at least for proposing a good, modern standard of species description without which a world-wide revision is hardly possible.

[Occurrence of metacerkariae Diplostomum sp. in the Siberian turgeon fry (Acipenser baeri Brandt)--preliminary study]. / Wystepowanie metacerkarii diplostomum sp. u narybku esiotra syberyjskiego (Acipenser baeri Brandt). Badania wstepne.

Siberian sturgeon fry coming from three different ponds has been examined. 1. "Dgal" - fish culture conerete-terrestrial pond beloning to D.O.Z. Dgal Inland Fisheries Institute in Olsztyn supplied with fresh water from Great Dgal Lake; 2. "Grzmieca" - fish culture pond terrestrial, natural belonging to fishing farm Grzmieca near Brodnica; 3. "Konin" - fish culture pond near Konin supplied with water utilized by near heat and power generating plant. Total of 80 sturgeons fry with parameters: length 17.5 cm - 38.5 cm, weight 21 g - 134 g, age 0+1+ has been examined. The examinated group of sturgenos had metacercariae Diplostomum sp. in their lenses. Prevalence of infection of sturgeon with metacercariae Diplostomum sp. was high in all this three ponds. Intensity of infection was also high in ponds "Dgal" and "Grzmieca", but low in "Konin". In ponds "Dgal" and "Konin" we have obtained high positive correlation ("Dgal" - r = 0,606, p < 0,05; "Konin" - r = 0,743, p < or = 0,01) between number of metacercariae in sturgeon and temperature of water. Our study confirmed observations other authors susceptibility sturgeon fry on the Diplostomum sp. invasion.

The effect of infestation with Diplostomum sp. on growth rate of Siberian sturgeon fry Acipenser baeri brandt.

The objective of the experiment was to compare the growth rate in two groups of Siberian sturgeon fry, one of which was infested with metacercariae of Diplostomum, the infestation degree was from 1 to 160/fish. The fish fed on natural as well as artificial food; the latter was given at the rate sufficient to cover 50% of the fish requirements. The average initial body weight in the control group was 16.8 +/- 1.9g, and in the group with Diplostomum - 28.4 +/- 3.6 g. During the period of favorable temperatures, viz. for about 90 days, the fry was showed satisfactory growth, but the growth rate became inhibited as the temperatures decreased to below 12 degrees C, so that throughout the wintering period the fish weight decreased by some 10%. Fish from the control group showed a higher growth rate than the infested ones, and by the end of the experiment the controls weighted 7.5% more than the infested group in spite of their lower initial weight.

An efficient sample preparation method for high-throughput analysis of 15(S)-8-iso-PGF2α in plasma and urine by enzyme immunoassay.

Although several methods have been reported on the analysis of the oxidative stress marker 15(S)-8-iso-prostaglandin-F2alpha (8-iso-PGF2α) in biological fluids, they either involve extensive sample preparation and costly technology or require high sample volume. This study presents a sample preparation method that utilizes low sample volume for 8-iso-PGF2α analysis in plasma and urine by an enzyme immunoassay (EIA). In brief, 8-iso-PGF2α in deproteinized plasma or native urine sample is complexed with an antibody and then captured by molecular weight cut-off filtration. This method was compared with two other sample preparation methods that are typically used in the analysis of 8-iso-PGF2α by EIA: Cayman's affinity column purification method and solid-phase extraction on C-18. The immunoaffinity purification method described here was superior to the other two sample preparation methods and yielded recovery values of 99.8 and 54.1% for 8-iso-PGF2α in plasma and urine, respectively. Analytical precision (relative standard deviation) was ±5% for plasma and ±15% for urine. The analysis of healthy human plasma and urine resulted in basal 8-iso-PGF2α levels of 31.8 ± 5.5 pg/mL and 2.9 ± 2.0 ng/mg creatinine, respectively. The robustness and analytical performance of this method makes it a promising tool for high-throughput screening of biological samples for 8-iso-PGF2α.