Characteristics of Lactobacillus parafarraginis ZH1 and its role in improving the aerobic stability of silages

AIMS

Lactobacillus parafarraginis ZH1 isolated from silage was characterized, and the effects of inoculating ZH1 and Lact. buchneri (LB) on the aerobic stability of sweet corn stalk (SCS) silage and whole-plant oat (WPO) silage ensiled at 15 and 30°C were studied.

METHODS AND RESULTS

After ensiling of SCS or WPO in plastic bottle silo for 45 days, silos were opened, and aerobic stability was studied by monitoring temperature change with thermo recorders in silage for 6 days. SCS silage and WPO silage were well conserved naturally at both storage temperatures. However, silages were prone to aerobic deterioration due to the presence of residual yeasts. ZH1 inoculated silages ensiled at both temperatures, LB inoculated silages ensiled at 30°C had better aerobic stability than the uninoculated silages and the LB-inoculated silage at 15°C.

CONCLUSIONS

Strain ZH1 improved the aerobic stability of SCS silage and WPO silage ensiled at both 15 and 30°C, while LB improved the aerobic stability of silage only ensiled at the high temperature of 30°C.

SIGNIFICANCE AND IMPACT OF THE STUDY

The new strain ZH1 can be used as an effective inhibitor for aerobic deterioration of silage maintained from 15 to 30°C.

VP292 of White spot syndrome virus Interacts with VP26

Interactions between virus structural proteins are suggested to be crucial for virus assembly. Many steps in the process of white spot syndrome virus (WSSV) assembly and maturation remain unclear. In this paper, we discovered a new interaction of WSSV VP292. Temporal-transcription analysis showed that VP292 is expressed in the late stage of WSSV infection. Western blot and matrix-assisted laser desorption ionization MS assays showed that VP292 interacts with VP26, a major envelope protein. Far-western blot provided further evidence for interaction between VP292 and VP26. These results collectively demonstrated that VP292 anchors to the envelope through interaction with VP26.

Osteogenesis induced in goat bone marrow progenitor cells by recombinant adenovirus coexpressing bone morphogenetic protein 2 and basic fibroblast growth factor

Bone morphogenetic protein 2 (BMP2) and basic fibroblast growth factor (bFGF) have been shown to exhibit a synergistic effect to promote bone repair and healing. In this study, we constructed a novel adenovirus with high coexpression of BMP2 and bFGF and evaluated its effect on osteogenic differentiation of goat bone marrow progenitor cells (BMPCs). Recombinant adenovirus Ad-BMP2-bFGF was constructed by using the T2A sequence. BMPCs were isolated from goats by density gradient centrifugation and adherent cell culture, and were then infected with Ad-BMP2-bFGF or Ad-BMP2. Expression of BMP2 and bFGF was detected by ELISA, and alkaline phosphatase (ALP) activity was detected by an ALP assay kit. In addition, von Kossa staining and immunocytochemical staining of collagen II were performed on BMPCs 21 days after infection. There was a high coexpression of BMP2 and bFGF in BMPCs infected with Ad-BMP2-bFGF. Twenty-one days after infection, ALP activity was significantly higher in BMPCs infected with Ad-BMP2-bFGF than in those infected with Ad-BMP2. Larger and more mineralized calcium nodules, as well as stronger collagen II staining, were observed in BMPCs infected with Ad-BMP2-bFGF than in those infected with Ad-BMP2. In summary, we developed a novel adenovirus vector Ad-BMP2-bFGF for simultaneous high coexpression of BMP2 and bFGF, which could induce BMPCs to differentiate efficiently into osteoblasts.

Germline-specific and sexually dimorphic expression of a dead end gene homologue in turbot (Scophthalmus maximus)

Germ cells are indispensable for gonadal development and fertility. However, the physiological mechanisms regulating germ cell development in marine fish are poorly understood due to a lack of germ cell markers. The dead end (dnd) gene is a vertebrate-specific component of germplasm crucial for primordial germ cells (PGCs) migration and development in teleosts. In this study, we identified a dnd homologue (Smdnd) in turbot (Scophthalmus maximus) and investigated its expression pattern during embryogenesis and gonadal development. The deduced amino acid sequence of Smdnd shared several conserved motifs of Dnd homologues as well as high identity to other Dnd proteins. Phylogenetic analysis revealed that the SmDnd was closely related to its teleost counterparts. Reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization revealed that Smdnd transcripts could be exclusively detected in germ cells, including presumptive PGC and adult male and female germ cells. In addition, an interesting sexually dimorphic expression of Smdnd during gonadal development was observed by real-time PCR. Female turbot showed greater (P < 0.05) Smdnd expression than male before sex maturation. This difference reduced gradually due to the upregulation of Smdnd in the male during the period corresponding to spermatogonia proliferation and meiosis. These results indicate that Smdnd can be used as a germ cell marker in turbot. In addition, the temporal and sex differences in Smdnd expression indicate that this gene may play different roles in gonadal development in both sexes.

Specific and rapid diagnosis of Edwardsiella tarda by a novel loop-mediated isothermal amplification targeting the upstream region of hlyb gene

Edwardsiella tarda has become one of the most severe pathogens in aquaculture industries throughout the world; therefore, a specific and rapid identification method for this bacterium is urgently needed. In the present study, a novel loop-mediated isothermal amplification (LAMP) was developed by targeting the upstream region of the hlyb gene of E. tarda, which was then named as UH-LAMP. The Mg(2+) concentrations, the reaction temperature, and the reaction time of UH-LAMP were optimized to 10 mM, 65°C, and 45 min, respectively. The detection limit of the UH-LAMP was 100-times higher than that of conventional polymerase chain reaction (10 versus 1000 CFU/test). Furthermore, the new UH-LAMP assay showed no cross-reactivity to the E. ictaluri belonging to the other species in the genus Edwardsiella. The high specificity of the assay was also confirmed by testing the nine strains of E. tarda collected from different geographical locations and the other 20 bacteria species. The assay can be performed in a simple water bath or a heat block and the detection result can be visualized by adding a fluorescent reagent to the reaction mixture. Taken together, our preliminary results indicate that this UH-LAMP assay provided a rapid, sensitive, and species-specific diagnostic tool for E. tarda and can easily be applied for the diagnosis under clinical or onsite conditions.

Characteristics of lactic acid bacteria isolates and their inoculating effects on the silage fermentation at high temperature

Thermotolerant strains of lactic acid bacteria (LAB) were screened for their suitability for silage making at high temperatures. Four selected strains were identified by 16S rRNA sequencing analyses and added to unwilted and wilted Italian ryegrass for ensiling at 45°C. All four strains (HT1, HT2, HT3 and HT4) grew at 50°C and pH 4·0. Strains HT1 and HT2 were identified as Lactobacillus rhamnosus; HT3 and HT4 were identified as Lact. fermentum. Strains HT1 and HT2 were the most effective at improving the fermentation quality of Italian ryegrass silage, irrespective of wilting, as indicated by lower pH values, less NH(3) -N, and more lactic acid. In contrast, strains HT3, HT4 and a commercial inoculant consisting of Lact. plantarum and Pediococcus acidilactici conferred no or reduced benefits. Wilting alone did not improve the fermentation quality of Italian ryegrass at 45°C. Inoculating with thermotolerant Lact. rhamnosus HT1 and HT2 could improve the fermentation quality of silage at high temperatures. Lactobacillus rhamnosus HT1 and HT2 can be used as inoculants for silage making in the tropics and subtropics and could play an important role in developing silage production in such regions.

SIGNIFICANCE AND IMPACT OF THE STUDY

Grasses are often difficult to ensile in the tropics and subtropics because of the high temperatures there. To solve this problem, we screened for thermotolerant lactic acid bacteria and obtained two valuable strains of Lactobacillus rhamnosus, HT1 and HT2, which proved to be beneficial to silage fermentation at high temperatures. Lactobacillus rhamnosus HT1 and HT2 can be used as inoculants for silage making in the tropics and subtropics, and will play an important role in developing silage production in such regions.

VP90 of white spot syndrome virus interacts with VP26 and VP28

Identification of structural protein relationships is likely to be important for virus assembly and anti-WSSV strategies. In this paper, VP90 of white spot syndrome virus (WSSV) was characterized. Temporal-transcription analysis showed that VP90 is expressed in the late stage of WSSV infection. Far-western and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) assay showed that VP90 interacts with VP26 and VP28, two major envelope proteins. Far-western blot with recombinant VP26 (rVP26), N-terminal end of VP28 (rVP28N) and C-terminal end of VP28 (rVP28C) provided further evidence for interaction of rVP90 and rVP26 or rVP28. These results suggest that VP90 is anchored to the envelope through interacting with VP26 and VP28.

Digestive enzyme activities of turbot (Scophthalmus maximus L.) during early developmental stages under culture condition

Digestive enzyme activities were analysed in turbot (Scophthalmus maximus) from hatching until 60 days after hatching (DAH). Trypsin sharply increased to the climax at 17 DAH and decreased until 31 DAH followed by a stable level thereafter. Amylase was determined at 4 DAH, reached the maximum value at 19 DAH and declined sharply to 39 DAH and remained at a low level thereafter, suggesting the carbohydrate component should remain at a low level in formulated diets. Pepsin was detected at 9 DAH and increased to 34 DAH and then remained at a stable level. The above results revealed pancreatic enzymes are no longer main enzymes for food digestion after the formation of functional stomach. Leucine-alanine peptidase (Leu-ala) and alkaline phosphatase (AP) and leucine aminopeptidase N (LAP) were found in newly hatched larvae. Both AP and LAP activities markedly increased to 23 DAH, decreased abruptly to 50 DAH and increased gradually to 60 DAH. Leu-ala reached the plateau from 23 to 39 DAH, followed by a decline to 46 DAH and an increase until 60 DAH. The brush border membrane (BBM)-bound enzyme activities increased from 30% at 31 DAH to 81% at 38 DAH of the total activities, indicating the maturation of intestinal tract.

Skeletal development and abnormalities of the vertebral column and of the fins in hatchery-reared turbot Scophthalmus maximus

To describe the skeletal development and abnormalities in turbot Scophthalmus maximus, samples were collected every day from hatching to 60 days after hatching (DAH). A whole-mount cartilage and bone-staining technique was used. Vertebral ontogeny started with the formation of anterior haemal arches at 5·1 mm standard length (L(S) ) c. 11 DAH, and was completed by the full attainment of parapophyses at 16·9 mm L(S) c. 31 DAH. Vertebral centra started to develop at 6·3 mm L(S) c. 16 DAH and ossification in all centra was visible at 11·0 mm L(S) c. 25 DAH. The caudal fin appeared at 5·1 mm L(S) c. 11 DAH and ossification was visible at 20·6 mm L(S) c. 37 DAH. The onset of dorsal and anal fin elements appeared at 5·8 mm L(S) c. 15 DAH and 6·3 mm L(S) c. 16 DAH, respectively. Ossifications of both dorsal fin and anal fin were visible at 20·6 mm L(S) c. 37 DAH. The pectorals were the only fins present before first feeding, their ossifications were completed at 23·5 mm L(S) c. 48 DAH. Pelvic fins began forming at 7·2 mm L(S) c. 19 DAH and calcification of the whole structure was visible at 19·8 mm L(S) c. 36 DAH. In the present study, 24 types of skeletal abnormalities were observed. About 51% of individuals presented skeletal abnormalities, and the highest occurrence was found in the haemal region of the vertebral column. As for each developmental stage, the most common abnormalities were in the dorsal fin during early metamorphic period (stage 2), vertebral fusion during climax metamorphosis (stage 3) and caudal fin abnormality during both late-metamorphic period (stage 4) and post-metamorphic period (stage 5). Such research will be useful for early detection of skeletal malformations during different growth periods of reared S. maximus.

Germ cells and fertilization differences among Japanese flounder Paralichthys olivaceus, summer flounder Paralichthys dentatus and their first and second generations

The morphology of gametes and the fertilization biology of Japanese flounder Paralichthys olivaceus (Po), summer flounder Paralichthys dentatus (Pd) and their hybrids were examined. Multiple generations (two hybrids: Po♀× Pd♂ (F1) and Pd♀× Po♂; two backcrosses: F1♀× Po♂ and F1♀× Pd♂) were obtained by artificial insemination. Comparison of egg ultrastructure among Po, Pd and F1 showed the morphology of micropyle region and the distribution density of pores were species specific. There were c. 100-200 accessory openings around the micropyle in Po, but not in Pd and F1. The zona radiata thickness and number of parallel bands were similar between F1 and Po, which were different from Pd. Comparison of spermatozoa ultrastructure revealed a close relationship between Po and Pd. Cytologically, the six crosses obeyed normal fertilization and cleavage processes, and only one male pronucleus was observed in a fertilized egg, indicating a monospermic fertilization pattern. Analysis of the time distribution from fertilization to first cleavage revealed an obvious delay at pronucleus fusion in the Pd × Po cross. The delay might indicate some cytoplasmic-nuclear incompatibility during the process of fertilization.

Study on permeability of DMSO in embryos of red seabream (Pagrus major) by capillary electrophoresis

The objectives were to investigate the permeability of DMSO to red seabream (Pagrus major) embryos by capillary electrophoresis and the effects of DMSO concentrations (5 to 40 percent, volume basis) and immersion times (10, 30 and 60 min) on hatching rate and morphology. The results suggested the internal DMSO concentrations were positively related with the external concentrations and exposure times, while the hatching rate was negatively related. The hatching rate decreased drastically (less than 50 percent) after exposure in 35 percent, 20 percent and 15 percent DMSO for over 10, 30 and 60 min, respectively. In all groups, when hatching rate was greater 50 percent, the internal DMSO concentration was less than 2 percent, which was still insufficient for successful cryopreservation. Morphological changes indicated the chorion was permeable to the cryoprotectant. A sign of dehydration in yolk were observed, for a significant decrease in the maximal yolk sac diameter. However, further research was needed to investigate whether the DMSO permeated into the yolk.

Bilateral Bispectral Index (BIS)-Vista as a measure of physiologic sleep in sleep-deprived anesthesiologists

BACKGROUND

Anesthesiologists who work extended hours exhibit acute and chronic sleep deprivation. The newest bilateral Bispectral Index (BIS)-Vista monitor offers new advantages over earlier models, which include a new algorithm (version 1.4). One possible useful application for BIS monitoring of physiological sleep would be in critically ill patients who almost uniformly suffer from sleep disruption and deprivation because they loose their circadian rhythm due to the harsh noisy environment of critical care units. Previous studies, which used earlier versions of the BIS monitor to depict normal physiologic sleep, produced widely conflicting results. The aim of our study was to assess whether the new BIS-Vista monitor would exhibit a temporal decline that corresponds to natural physiologic sleep stages in healthy sleep-deprived, post-call anesthesiologists.

METHODS

BIS-Vista sensors were bilaterally mounted, according to the manufacturer guidelines, onto the forehead of 10 healthy sleep-deprived volunteer anesthesiologists. Using the conventional Rechtschaffen and Kales criteria, BIS values during the awake, S1, S2, S3, S4, and rapid eye movement (REM) sleep stages were recorded.

RESULTS

Mean±SD BIS values during the awake, S1, S2, S3, S4, and REM sleep stages significantly declined for the left (96±2, 82±11, 73±10, 53±13, 43±11, 66±9) and right (97±2, 78±11, 69±9, 50±10, 39±13, 61±14) hemispheres respectively. There were no significant interhemispheric differences in BIS values over time (two-way ANOVA). However, in one subject, the left and right BIS values were mostly discordant throughout the recordings.

CONCLUSION

We demonstrated that although the BIS-Vista monitor was neither designed nor validated for monitoring normal physiologic sleep, it depicted a temporal decline that corresponds to normal physiologic sleep stages in sleep-deprived anesthesiologists.

Changes in RNA, DNA, protein contents and growth of turbot Scophthalmus maximus larvae and juveniles

The growth potential of turbot Scophthalmus maximus larvae and juveniles was studied using nucleic acid-based indices and protein variables. The experiment was carried out from 4 to 60 days post hatching (dph). A significant increase in instantaneous growth rate during metamorphosis and retarded growth rate during post-metamorphic phase were observed. Ontogenetic patterns of DNA, RNA and protein all showed developmental stage-specific traits. The RNA:DNA ratio decreased up to 12 dph, then increased rapidly till 19 dph and fluctuated until 35 dph followed by a decline to the end. The RNA:DNA ratio was positively correlated with growth rate of juveniles during the post-metamorphic phase, whereas this ratio was not a sensitive indicator of growth during the pre-metamorphic phase and metamorphosis. The protein:DNA ratio showed a similar tendency to the RNA:DNA ratio. Changes of DNA content and protein:DNA ratio revealed that growth of S. maximus performed mainly by hyperplasia from 4 to 12 dph and hypertrophy until 21 dph during the pre-metamorphic larval phase. Growth was dominantly hypertrophical from the early- to mid-metamorphosing phase and hyperplastic thereafter. The results show that the DNA content and protein:DNA ratio can evaluate growth rates of larval and juvenile S. maximus on a cellular level.

Removal effect of Cr (VI) by adsorbent made from sewage sludge

Adsorbent made from sewage sludge is used to remove the Cr (VI) in wastewater. In this paper, the adsorption capacity, adsorption mechanism and regeneration of the adsorbent are studied. A systematic research is carried out to investigate the influence of adsorption capacities in various conditions, such as contact time, pH and initial dosage of adsorbent. The results show that: the equilibrium time is 6 h; the optimal pH is 2.5. The adsorption capacity increases as the initial concentration increase and as the dosage of activated carbon decrease. The data of adsorption capacity are more fit in Langmuir isotherms. The adsorption follows a pseudo-second-order kinetic model perfectly. From this research, the adsorption rate controlling step is film diffusion when the Cr (VI) concentration is low; otherwise, the adsorption rate controlling step is the diffusion among particles. The results of regeneration of saturated adsorbent show that the saturated adsorbent can be perfectly regenerated using alkali treatment. The regeneration ratio of the saturated adsorbent can reach more than 90% with proper concentration of alkali.

Lectins but not antifungal proteins exhibit anti-nematode activity

A variety of lectins and antifungal proteins were tested for toxicity against the plant parasitic nematodes Ditylenchus dipsaci and Heterodera glycines. It was found that lectins from the mushrooms Xylaria hypoxylon, Agrocybe cylindracea and Tricholoma mongolicum (TML-1) were the most potent against D. dipsaci, with EC(50) being 4.7, 9, and 20mg/ml, respectively. Lectins from Pseudostellaria heterophylla, samta tomato, and the mushrooms T. mongolicum (TML-2), Ganoderma lucidum, and Boletus edulis, and antifungal proteins from Ginkgo biloba toward D. dipsaci and pumpkin Cucurbita moschata had much lower anti-nematode potencies and could be considered as inactive for practical purposes. All lectins except that from P.heterophylle were potent against H.glycines.

White spot syndrome virus VP37 interacts with VP28 and VP26

White spot syndrome virus (WSSV) is one of the most virulent pathogens affecting penaeid shrimp, causing high mortality in infected populations. Interactions between virus structural proteins are likely to be important for virus assembly. Many steps of the WSSV assembly and maturation pathway remain unclear. In the present study, the interaction between VP37 and envelope or nucleocapsid proteins was characterized. VP37 was expressed in Escherichia coli and confirmed by Western blotting. Pure WSSV virions were subjected to Triton X-100 treatment to separate the envelope and nucleocapsid fractions. Overlay assays showed that VP37 interacted with VP28 and VP26. The interaction of VP37 with VP28 and VP26 was confirmed further by His pull-down and matrix-assisted laser desorption ionization (MALDI) mass spectrographic assays. The binding assay of VP37 with VP28 by ELISA confirmed that the 2 proteins had direct interaction in vivo. This discovery will help elucidate the molecular mechanisms of virion morphogenesis.

An efficient MR image reconstruction method for arbitrary K-space trajectories without density compensation

Non-Cartesian sampling is widely used for fast magnetic resonance imaging (MRI). The well known gridding method usually requires density compensation to adjust the non-uniform sampling density, which is a major source of reconstruction error. Minimum-norm least square (MNLS) reconstruction, on the other hand, does not need density compensation, but requires intensive computations. In this paper, a new version of MNLS reconstruction method is developed using maximum likelihood and is speeded up by incorporating novel non-uniform fast Fourier transform (NUFFT) and bi-conjugate gradient fast Fourier transform (BCG-FFT) techniques. Studies on computer-simulated phantoms and a physically scanned phantom show improved reconstruction accuracy and signal-to-noise ratio compared to gridding method. The method is shown applicable to arbitrary k-space trajectory. Furthermore, we find that the method in fact performs un-blurring in the image space as an equivalent of density compensation in the k-space. Equalizing MNLS solution with gridding algorithm leads to new approaches of finding optimal density compensation functions (DCF). The method has been applied to radially encoded cardiac imaging on small animals. Reconstructed dynamic images of an in vivo mouse heart are shown.

Regional patterns of soil organic carbon stocks in China

Soil organic carbon (SOC) is of great importance in the global carbon cycle. Distribution patterns of SOC in various regions of China constitute a nation-wide baseline for studies on soil carbon changes. This paper presents an integrated and multi-level study on SOC stock patterns of China, and presents baseline SOC stock estimates by great administrative regions, river watersheds, soil type regions and ecosystem. The assignment is done by means of a recently completed 1: 1,000,000 scale soil database of China, which is the most detailed and reliable one in China at the present time. SOC densities of 7292 soil profiles collected across China in the middle of the 1980s were calculated and then linked to corresponding polygons in a digital soil map, resulting in a SOC Density Map of China on a 1: 1,000,000 scale, and a 1 km x 1 km grid map. Corresponding maps of administrative regions, river watersheds, soil types (ST), and ecosystems in China were also prepared with an identical resolution and coordinate control points, allowing GIS analyses. Results show that soils in China cover an area of 9.281 x 10(6)km(2) in total, with a total SOC stock of 89.14 Pg (1 Pg=10(15)g) and a mean SOC density of 96.0 t C/ha. Confidence limits of the SOC stock and density in China are estimated as [89.23 Pg, 89.08 Pg] and [96.143 t C/ha, 95.981 t C/ha] at 95% probability, respectively. The largest total SOC stock (23.60 Pg) is found in South-west China while the highest mean SOC density (181.9 t C/ha) is found in north-east China. The total SOC stock and the mean SOC density in the Yangtze river watershed are 21.05 Pg and 120.0 t C/ha, respectively, while the corresponding figures in the Yellow river watershed are 8.46 Pg and 104.3 t C/ha, respectively. The highest total SOC stocks are found in Inceptisols (34.39 Pg) with SOC density of 102.8 t C/ha. The lowest and highest mean SOC densities are found on Entisols (28.1 t C/ha), and on Histosols (994.728.1 t C/ha), respectively. Finally, the total SOC stock in shrub and forest ecosystem classes are 25.55 and 21.50 Pg, respectively; the highest mean SOC density (209.9 t C/ha) was recorded in the wetland ecosystem class and the lowest (29.0 t C/ha) in the desert ecosystem class. Among five forest ecosystem types, Evergreen conifer forest stores the highest SOC stock (6.81 Pg), and Deciduous conifer forest shows the highest SOC density (225.9 t C/ha). Figures of SOC stocks stratified by Administrative regions, river watersheds, soil types and ecosystem types presented in the study may constitute national-wide baseline for studies of SOC stock changes in various regions in the future.

An alkaline protease from fresh fruiting bodies of the edible mushroom Pleurotus citrinopileatus

A protease was purified from fresh fruiting bodies of the edible mushroom Pleurotus citrinopileatus. The isolation procedure included ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose and fast protein liquid chromatography-gel filtration on Superdex 75. The protease was unadsorbed on DEAE-cellulose and Q-Sepharose, but adsorbed on CM-cellulose. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the protease demonstrated a single band with a molecular mass of 28 kDa. The protease showed an optimal pH at 10 and an optimal temperature at 50 degrees C. The activity of the protease was not affected by EDTA, indicating that it is not a metalloprotease. The protease exhibited a higher activity in the presence of K(+) and Li(+), but its activity was potently inhibited by Al(3+), Cu(2+), and Hg(2+) ions. It manifested a K (m) of 3.44 mg/ml and a V (max) of 0.139 mg ml(-1) min(-1). It was devoid of ribonuclease and antifungal activities.

Flow cytometry and ultrastructure of cryopreserved red seabream (Pagrus major) sperm

The objectives were to assess motility, fertilizing capacity, structural integrity, and mitochondrial function in fresh versus frozen-thawed (15% DMSO was used as a cryoprotectant) sperm from red seabream (Pagrus major). Mean (+/-S.D.) rates of motility, fertilization and hatching of frozen-thawed sperm were 81.0+/-5.4, 92.8+/-1.9, and 91.8+/-5.2%, respectively; for fresh sperm, they were 87.5+/-7.7, 95.8+/-2.4, and 93.8+/-4.2%. Although motility was lower in frozen-thawed versus fresh sperm (P<0.05), there was no effect (P>0.05) of cryopreservation on fertilization or hatching. Based on scanning and transmission electron microscopy, 77.8+/-5.6% of fresh sperm had normal morphology, whereas for frozen-thawed sperm, 63.0+/-7.2% had normal morphology, 20.6+/-3.1% were slightly damaged (e.g. swelling or rupture of head, mid-piece and tail region as well as mitochondria), and 16.4+/-4.2% were severely damaged. Sperm were stained with propidium iodide and Rhodamine 123 to assess plasma membrane integrity and mitochondrial function, respectively, and examined with flow cytometry. For fresh sperm, 83.9% had an intact membrane and functional mitochondria, whereas for frozen-thawed sperm, 74.8% had an intact membrane and functional mitochondria, 12.7% had a damaged membrane, 9.9% had nonfunctional mitochondria, and 2.6% had both a damaged membrane and nonfunctional mitochondria. In conclusion, ultrastructure and flow cytometry were valuable for assessment of frozen-thawed sperm quality; cryopreservation damaged the sperm but fertilizing ability was not significantly decreased.

Fluids in porous media. I. A hard sponge model

The morphology of many porous materials is spongelike. Despite the abundance of such materials, simple models which allow for a theoretical description of these materials are still lacking. Here, we propose a hard sponge model which is made by digging spherical cavities in a solid continuum. We found an analytical expression for describing the interaction potential between fluid particles and the spongelike porous matrix. The diagrammatic expansions of different correlation functions are derived as well as that of grand potential. We derived also the Ornstein-Zernike (OZ) equations for this model. In contrast to Madden-Glandt model of random porous media [W. G. Madden and E. D. Glandt, J. Stat. Phys. 51, 537 (1988)], the OZ equations for a fluid confined in our hard sponge model have some similarity to the OZ equations of a three-component fluid mixture. We show also how the replica method can be extended to study our sponge model and that the same OZ equations can be derived also from the extended replica method.

Isolation and characterization of a novel lectin from the mushroom Armillaria luteo-virens

From the dried fruiting bodies of the mushroom Armillaria luteo-virens, a dimeric lectin with a molecular mass of 29.4 kDa has been isolated. The purification procedure involved (NH(4))(2)SO(4) precipitation, ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of the lectin could not be inhibited by simple sugars but was inhibited by the polysaccharide inulin. The activity was stable up to 70 degrees C but was acid- and alkali-labile. Salts including FeCl(3), AlCl(3), and ZnCl(2) inhibited the activity whereas MgCl(2), MnCl(2), and CaCl(2) did not. The lectin stimulated mitogenic response of mouse splenocytes with the maximal response achieved by 1microM lectin. Proliferation of tumor cells including MBL2 cells, HeLa cells, and L1210 cells was inhibited by the lectin with an IC(50) of 2.5, 5, and 10 microM, respectively. However, proliferation of HepG2 cells was not affected. The novel aspects of the isolated lectin include a novel N-terminal sequence, fair thermostability, acid stability, and alkali stability, together with potent mitogenic activity toward spleen cells and antiproliferative activity toward tumor cells.

Isarfelin, a peptide with antifungal and insecticidal activities from Isaria felina

Isarfelin, a peptide with inhibitory activity on mycelial growth in Rhizoctonia solani and Sclerotinia sclerotiorum and insecticidal activity toward Leucania separata, was isolated from the mycelia of Isaria felina. The IC50 value of its antifungal activity against R. solani was 3.1 microg mL(-1). However, it was devoid of activity toward several bacterial species including Bacillus subtilis, E. coli and Staphylococcus aureus. The isolation procedure involved ethanol extraction, adsorption on YPR II macropore adsorption resin, ethyl acetate extraction, petroleum ether precipitation and recrystallization from ethyl acetate.

A novel homodimeric lactose-binding lectin from the edible split gill medicinal mushroom Schizophyllum commune

A homodimeric lactose-binding lectin with a molecular mass of 64kDa was isolated from fresh fruiting bodies of the split gill mushroom Schizophyllum commune. The N-terminal sequence of the lectin is similar to a part of the sequence of the cell division protein from Gleobacter violaceus. The lectin was isolated by using a procedure which involved ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The hemagglutinating activity of the lectin was stable at temperatures up to 40 degrees C, and in concentrations of NaOH and HCl solution up to 125 and 25mM, respectively. The lectin exhibited potent mitogenic activity toward mouse splenocytes, antiproliferative activity toward tumor cell lines, and inhibitory activity toward HIV-1 reverse transcriptase. It was devoid of antifungal activity.