Species Differences In Activity Research Articles

English

Antimicrobial activity of crude venom extracts from different honeybee species was tested against selected pathogens. Toxicity of bee venom is known to man since ages, which varies from mild inflammations to death. Bee venom is synthesized in the venom glands of worker bees and queen and is stored in the venom sac. In the present study the toxic potentialities of honeybee venom pertaining to different honeybee species Apis cerana, Apis dorsata and Apis florea was carried out in vitro on selected species of bacteria and fungi. The selected bacteria and fungal species were Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Xanthomonas subtilis, Proteus vulgaris, Salmonella typhimurium and Candida albicans. They were collected from St. John Medical College, Bangalore. The antimicrobial activity of different species of Apis bee venom (ABV) was studied by Disc Diffusion Assay. Minimal inhibitory concentration (MIC) was determined using Broth dilution method at lowest dilution (0.5 mg/ml). Bacterial growth was assessed by the measurement of inhibitory zone. The order of susceptibility of the pathogens against the ABV recorded was: A. cerana > Apis dorsata> Apis florea.The results showed that, ABV has significant antimicrobial effects and could be a potential alternative antibiotic. Key words: Bee venom, Apis species, broth dilution, inhibitory zone, bacteria, fungi.

Evidence for Divergent Evolution of Growth Temperature Preference in Sympatric Saccharomyces Species

The genus Saccharomyces currently includes eight species in addition to the model yeast Saccharomyces cerevisiae, most of which can be consistently isolated from tree bark and soil. We recently found sympatric pairs of Saccharomyces species, composed of one cryotolerant and one thermotolerant species in oak bark samples of various geographic origins. In order to contribute to explain the occurrence in sympatry of Saccharomyces species, we screened Saccharomyces genomic data for protein divergence that might be correlated to distinct growth temperature preferences of the species, using the dN/dS ratio as a measure of protein evolution rates and pair-wise species comparisons. In addition to proteins previously implicated in growth at suboptimal temperatures, we found that glycolytic enzymes were among the proteins exhibiting higher than expected divergence when one cryotolerant and one thermotolerant species are compared. By measuring glycolytic fluxes and glycolytic enzymatic activities in different species and at different temperatures, we subsequently show that the unusual divergence of glycolytic genes may be related to divergent evolution of the glycolytic pathway aligning its performance to the growth temperature profiles of the different species. In general, our results support the view that growth temperature preference is a trait that may have undergone divergent selection in the course of ecological speciation in Saccharomyces.

Comparative Study of Phenolic Compounds and Antioxidant Activity in Different Species of Cherries

A new spectrometric method ultra performance liquid chromatography-tandem mass spectrometric with high precision and rapid analysis was developed to separate 17 phenolic compounds. Different species of cherries, including 10 sweet cherry (Prunus avium L.) cultivars, a tart cherry (P. cerasus L.) rootstock (CAB), and a hybrid rootstock 'Colt' (P. avium × P. pseudocerasus), were analyzed for phenolics contents by this method. The results showed that significant differences were observed among the phenolic compound contents in different cherry species. In 10 sweet cherry cultivars, the contents of neochlorogenic acid and cyanidin-3O-rutinoside were much higher in red-colored fruits (for example, 64.60 and 44.50 mg/100 g fresh weight in Burlat, respectively) than those in bicolored ones. Principal component analysis revealed that cyanidin-3O-rutinoside was an effective index for grouping the cultivars with similar species and fruit colors. Moreover, there were strong positive correlations between phenolics content and antioxidant activity, which was higher in red-colored cherries.

Evaluation of the antibacterial activity of different species of phytoplankton

The antibiotic activity of organic extracts from cultures of six species of phytoplankton, Synechococcus elongatus, Synechocystis sp., Amphiprora paludosa, Porphyridium cruentum, Chaetoceros muelleri and Dunaliella tertiolecta was examined. The bacteria used were Gram(-) strains, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae, and the Gram(+) strains were Bacillus subtilis, Staphylococcus aureus, and Microccocus luteus. All extracts inhibited the growth of B. subtilis and effected the generation of inhibition halos, ranging in diameter from 7.06 to 15.23 mm, for several bacteria species. Wide-spectrum antibacterial activity was observed in extracts from S. elongatus, Synechocystis sp., A. paludosa, P. cruentum, and C. muelleri. Thus, this five phytoplankton species can be used to control bacteria.

Time and seasonal patterns of activity of phyllostomid in fragments of a stational semidecidual forest from the Upper Paraná River, Southern Brazil

Bats may exhibit different patterns of activity, considering aspects concerning niche dynamics as well as the establishment and permanence of the communities in the ecosystems. In this way, the present study analyzed the time and seasonal patterns of activity in different species of frequent phyllostomid bats in remnants of the stational semidecidual forest from the Upper Paraná River, Southern Brazil. Captures were performed between January and December, 2006, using 32 mist nets set above the soil along the nocturnal period during the four seasons of the year. The daily and seasonal patterns of activity of each species was modeled using generalized linear models with Poisson error. The best model was selected using Akaike's Information Criterion (AICc). Artibeus planirostris (Spix, 1823) did not exhibit a conspicuous time pattern, whereas A. lituratus (Olfers, 1818) was more frequent after the sixth hour and A. fimbriatus Gray, 1838 had an activity increase along the night. Platyrrhinus lineatus (E. Geoffroy, 1810) was registered during all sampling hours. Carollia perspicillata (Linnaeus, 1758) and Sturnira lilium (E. Geoffroy, 1810) were the most active during the first four hours. Concerning seasonal pattern, the highest activity of these species was verified during the summer. These data contribute to the information about the ecology of bats in the region, highlighting the high adaptive potential of the species studied in relation to the use of space throughout the night and in to variations in environmental conditions.

Effects of ectopic expression of human telomerase reverse transcriptase on immortalization of feather keratinocyte stem cells

Normal somatic cells possess a finite life span owing to replicative senescence. Telomerase functions as a potential regulator of senescence in various cells. Expression level of human telomerase reverse transcriptase (hTERT) is correlated with telomerase activity and cellular immortalization. In this study, we investigated the effects of ectopic expression of hTERT on proliferation potential of chicken feather keratinocyte stem cells (FKSCs). We established FKSCs transduced with hTERT catalytic subunit fused with EGFP marker gene (hTERT-EGFP-FKSCs). hTERT-EGFP-FKSCs had the great potential of proliferation in vitro and expressed kerainocyte stem cell markers integrin beta1 and CD49c. Keratin 15 and keratin 19, as native FKSCs, were also detected in hTERT-EGFP-FKSCs. By the analysis of fluorescent RT-PCR, western blotting and TRAP assay, hTERT-EGFP-FKSCs were positive for telomerase activity, in comparison with native FKSCs showing no telomerase activity. We demonstrated that ectopic expression of hTERT could result in immortalization of FKSCs. Tumorigenecity of hTERT-EGFP-FKSCs were examined by soft agar assay and transplantation into NOD-SCID mice. Results showed that hTERT-EGFP-FKSCs sustained the cellular characteristics of native FKSCs and had no transforming activity. In vivo differentiation multipotentials of hTERT-EGFP-FKSCs were confirmed by transplantation into developing chicken embryos and in situ hybridization analysis. These data provide a novel framework for understanding human telomerase activity in different species and suggest a new insight for manipulating hTERT for therapeutic purposes in treating tissue injury and aging.

Esterase Activities in the Blood, Liver and Intestine of Several Preclinical Species and Humans

Species and tissue differences in the activity of three major classes of esterases, carboxylesterase (CE), butyrylcholinesterase (BChE) and paraoxonase (PON), were studied. Substantial species differences in activity of these esterases were observed between the mouse, rat, dog monkey and human. Such species differences must be considered when using these preclinical species to optimize the pharmacokinetic properties of ester compounds intended for human use.

MICOTOXINE'S STATUS IN VEGETAL FOOD- CONSEQUENCE OF THEIR PRESENCE IN GRAINS

The contamination of food with micotoxines is the result of a secondary metabolic activity of different species of moulds from the Aspergillus and Penicillium types [4]. Science the stable and persistent molecules are very toxic for humans and animals, the micotoxins are being studied more and more. In our country, the alimentary products that are based on cereals, have an important place in daily diet a reason for witch we have proposed to investigate the degree of contamination with micotoxines at these products. We have used for this the imunoenzimatic Elisa method for the following micotoxines total aflatoxina OTA, DON, ZEA.

Simulating the impact of cholinesterase-inhibiting pesticides on non-target wildlife in irrigated crops

We present a simulation model for risk assessment of the impact of insecticide inhibitors of cholinesterase (ChE) applied in irrigated agricultural fields on non-target wildlife. The model, which we developed as a compartment model based on difference equations (Δ t = 1 h), consists of six submodels describing the dynamics of (1) insecticide application, (2) insecticide movement into floodable soil, (3) irrigation and rain, (4) insecticide dissolution in water, (5) foraging and insecticide intake from water, and (6) ChE inhibition and recovery. To demonstrate application of the model, we simulated historical and “worst-case” scenarios of the impact of ChE-inhibiting insecticides on white-winged doves ( Zenaida asiatica) inhabiting natural brushland adjacent to cotton and sugarcane fields in the Lower Rio Grande Valley of Texas, USA. Only when a rain event occurred just after insecticide application did predicted levels of ChE inhibition surpass the diagnostic level of 20% exposure. The present model should aid in assessing the effect of ChE-inhibiting insecticides on ChE activity of different species that drink contaminated water from irrigated agricultural fields, and in identifying specific situations in which the juxtaposition of environmental conditions and management schemes could result in a high risk to non-target wildlife.

Detection of extracellular protease activity in different species and genera of ectomycorrhizal fungi

In northern forest ecosystems, most soil nitrogen (N) is in organic form and forest trees are largely dependent on ectomycorrhizal (ECM) fungi and their degradative abilities for N uptake. The ability of ECM fungi to acquire N from organic substrates should, therefore, be a widespread trait given its ecological importance. However, little is known about the degradative abilities of most ECM fungi as they remain untested due to problems of isolation or extremely slow growth in pure culture. In this paper, we present data on extracellular protease activity of 32 species of ECM fungi, most of which have not previously been cultured. Milk powder plates and zymograms were compared for detecting protease activity in these intractable species. In total, 29/32 of the species produced extracellular protease activity, but detection was method dependent. Growth on milk powder plates detected protease activity in 28 of 32 species, while zymograms only detected proteases in Amanita muscaria, Russula chloroides, Lactarius deterrimus and Lactarius quieticolor. The study supports the hypothesis that protease excretion is a widespread physiological trait in ECM fungi and that this ability is of considerable significance for nitrogen uptake in forest ecosystems.

Glutamate dehydrogenase activity in lactobacilli and the use of glutamate dehydrogenase-producing adjunct Lactobacillus spp. cultures in the manufacture of cheddar cheese

The study was undertaken to investigate the occurrence of glutamate dehydrogenase activity in different species of lactobacilli, and to determine, in a series of cheese-making trials, the effects of glutamate dehydrogenase-producing adjunct cultures on sensory attribute development during the maturation of cheddar cheese. The presence of dehydrogenase activity with glutamate as substrate was monitored in cell lysates of >100 strains from 30 different species of lactobacilli using a qualitative colorimetric plate screening assay. Activity was detectable in 25 of the 29 representative species obtained from culture collections and in 12 of the 13 non-starter species isolated from cheese. There were pronounced interspecies and strain differences in the occurrence, level and pyridine nucleotide specificity of the glutamate dehydrogenase activity detected. Among the non-starter lactobacilli the highest frequency of enzyme occurrence and activity was detected in the Lactobacillus plantarum isolates. The establishment of glutamate dehydrogenase-producing adjunct strains in the predominant population of lactobacilli in the cheese curd affected the formation of a number of volatile compounds in ripening cheddar cheese, while the presence of Lact. plantarum strains, in particular, was associated with an intensification and acceleration of aroma and flavour development during the maturation period. Glutamate dehydrogenase formation by lactobacilli is a strain-dependent metabolic attribute, and adjunct cultures expressing the activity that are able to proliferate during cheese ripening have a positive impact on the rate of development and the intensity of cheddar cheese aroma and flavour development. It has been demonstrated that some strains of glutamate dehydrogenase-producing lactobacilli have potential use as adjunct cultures to accelerate and intensify aroma and flavour formation during the manufacture of cheddar and, by analogy, other similar varieties of cheese. The importance of phenotypic discriminative monitoring of the dominant lactobacilli present during ripening to confirm adjunct establishment and population complexity was highlighted as was the requirement to establish the metabolic attributes of the non-starter population in uninoculated control cheeses in comparative trials.

Influence of the intertidal environment on muscle activity in different species of sea anemones (Actiniaria)

Abstract The muscular activity of the marginal sphincters of Oulactis muscosa ,Aulactinia marplatensis and Aulactinia reynaudi from the intertidal zones of two different ecosystems was compared. The study was made upon the quartzitic outcrop ecosystem of Punta Cantera and the sandbar ecosystem of Santa Clara del Mar from Mar del Plata (Argentina). The isolated marginal sphincters were stimulated at increasing KCl concentrations and analysed as a dose-response curve expressed in tension in grams (gr: grams force) vs. concentration. Sphincters of sea anemones from the outcrop ecosystem of Punta Cantera developed greater maximal tension than specimens from the sandbar ecosystem of Santa Clara del Mar. No significant differences were found between the species from Punta Cantera. The same result was observed for the species from Santa Clara del Mar. It was concluded that sphincters of sea anemones from Punta Cantera are adapted to resist the continuous dashing of waves. Hence, they developed higher isometric forces in their sphincters compared to those specimens from Santa Clara del Mar. These physiological responses are correlated with the different physiography of both ecosystems.

Identification and distribution of endoplasmic reticulum iPLA 2

Our laboratory demonstrated that endoplasmic reticulum iPLA 2 (ER-iPLA 2) activity protects renal cells from oxidant-induced cell death and lipid peroxidation. The goals of this study were to determine the PLA 2 isoform(s) responsible for ER-iPLA 2 activity in different species and tissues. ER-iPLA 2 activity was observed in microsomes from rabbit and rat kidney, heart, and brain as well as in human kidney (Caki-1 and HEK293) and glioblastoma (A172) cell lines. Reverse transcriptase-polymerase chain reaction results demonstrated the presence of iPLA 2γ (group VIB PLA 2) message in all tissues tested. Immunoblot analysis and PLA 2 inhibitor studies with methyl arachidonyl fluorophosphonate and enantiomers of bromoenol lactone demonstrated that the ER-iPLA 2 in rabbit kidney and heart and rat kidney is iPLA 2γ. These results demonstrate the expression of ER-iPLA 2γ (group VIB) across species and tissues, and suggest that iPLA 2γ may play critical roles in oxidant-induced cell injury.

Extracellular enzymatic activity of Malassezia spp. isolates.

Extracellular enzymatic activity of different species of Malassezia spp was evaluated. Thirty-three isolates of animal origin (dogs and cats) and stock culture samples were studied. Twenty isolates of M. pachydermatis, 8 of M. furfur, 2 of M. sympodialis and M. globosa and one of M. restricta, M. obtusa and M. slooffiae were examined. The enzymatic activity was investigated using Api Zym system. The enzymatic patterns showed light differences. Esterase lipase, Phosphatase acid and Naphtol-AS-BI-phosphohydrolase were produced in significant amounts from most isolates excepted for M. restricta, confirming the limited enzymatic activity of this species. Data obtained from the other new species described after the revision of the genus, appear to be quite homogeneous. Dixon's broth appeared to be a valid medium for the growth of all Malassezia spp.

Control of Ovarian Activity in Llamas (Lama glama) with Medroxyprogesterone Acetate

ContentsProgesterone and progestogens have proved to be effective in controlling follicle development and synchronization of ovarian activity in different species. In this study, vaginal sponges containing 120 mg medroxyprogesterone acetate were used to synchronize ovarian activity in llamas and to predict the time when a mature follicle will be present. Plasma concentrations of oestradiol‐17β and progesterone were measured to determine follicle and corpus luteum development. The sponges were kept in the vagina for 9 days. Six days after sponge withdrawal, ovulation was induced by either GnRH injection (n = 4), mating with a vasectomized male (n = 8) or mating with an intact male (n = 10). Plasma progesterone concentrations varied between animals until day 6 after insertion of the sponges. Thereafter, progesterone levels remained close to the detection limit of the assay until ovulation was induced. The mean oestradiol‐17β plasma concentration reached its lowest value 3–4 days after insertion of the sponges. Thereafter, concentrations increased and reached peak levels at day 6 after withdrawal of the sponges. All animals ovulated and developed a corpus luteum with a normal life span after the ovulatory stimulus. Blood samples were collected frequently after mating to evaluate the endocrine response to copulation. Plasma concentrations of PGF2α metabolite and cortisol increased in parallel after copulation. The metabolite concentrations returned to basal levels 3–4 h after mating whereas the cortisol concentrations remained elevated for about 12 h after copulation The luteinizing hormone secretory pattern resembled that reported when llamas with a mature ovulatory follicle were mated. In conclusion, the protocol evaluated in this study was shown to be useful for the synchronization of ovarian activity and for predicting the time when an ovulatory follicle will be present in llamas.

Ion-exchange column chromatographic method for assaying purine metabolic pathway enzymes

High energy phosphate levels fall rapidly during cardiac ischemia and recover slowly (more than one week) during reperfusion. The slow recovery of ATP may reflect a lack of purine metabolic precursors and/or increased activity of purine catabolic enzymes such as 5′-nucleotidase (5′-NT, EC 3.1.3.5) and adenosine deaminase (ADA, EC 3.5.4.4). The activity of enzymes involved in both the catabolism of ATP precursors (5-NT and ADA) and the restoration of ATP from slow synthetic pathways [adenosine kinase (AK, EC 2.7.1.20), adenine phosphoribosyl transferase (APRT, EC 2.4.2.7) and hypoxanthine phosphoribosyl transferase (HPRT, EC 2.4.2.8)] may directly affect the rate of ATP recovery. Strategies to enhance recovery will depend on the relative activity of these enzymes following ischemia. Their activity in different species and their response to ischemia are not well characterized. Hence, rapid assay methods for these enzymes would facilitate detailed time course studies of their activities in postischemic myocardium. We modified a single ion-exchange column chromatographic method using DEAE-Sephadex to determine the products of incubation of 5′-NT, AK, APRT and HPRT with their respective substrates. The uniformity of the final product measurement procedure for all assays permits the activities of the four enzymes to be rapidly determined in a single tissue sample and facilitates the study of a large number of samples. This technique should also be useful for enzymes of the pyrimidine metabolic pathway.

Species differences in the distribution of nitric oxide synthase in brain stem regions that regulate sympathetic activity

The distribution of nitric oxide synthases (NOS) in the lower brain stem was studied by NADPH-diaphorase staining with emphasis on the nucleus of the solitary tract and the ventrolateral medulla. The order of NOS density was hamster>rabbit=rat>mouse>guinea-pig>cat with little variation within species or between regions. This heterogeneity may partly explain qualitatively and quantitatively variable effects of NO on sympathetic activity in different species.

Relationship between Body Size and Anaerobic Metabolism in Brook Trout and Largemouth Bass

The relationship between body size, anaerobic capacity, and white muscle acid-base and metabolite status was examined for two sizes of brook trout Salvelinus fontinalis and largemouth bass Micropterus salmoides. Resting muscle lactate, pH, HCO3−, and partial pressure of carbon dioxide (Pco2) were size-independent in brook trout. After exercise, however, there was a significant positive relationship between the accumulation of both lactate and metabolic protons and body size in brook trout. In addition, there was a significant size-dependent decrease in postexercise muscle pH, with larger trout experiencing a more severe drop in muscle pH. In contrast, the postexercise changes in muscle HCO3− and Pco2 remained size-independent in trout. Having observed that anaerobic capacity (i.e., lactate production) apparently was affected by body size in trout, we measured the concentrations of two other anaerobic energy reserves—phosphocreatine (PCr) and ATP—in trout white muscle before and after exercise. Under resting conditions, large trout possessed greater concentrations of both ATP and PCr than smaller trout. After exercise, the levels of ATP and PCr decreased in all trout but were size-dependent and size-independent, respectively. Under resting conditions, muscle lactate, pH, HCO3−, and Pco2 remained size-independent in largemouth bass. After exercise, white muscle lactate and metabolic proton concentrations increased and pH decreased in all bass; however, in contrast with brook trout, none of these variables were significantly related to body size. The results of our in vivo experiments therefore agree with the previously documented in vitro relationships between body size and glycolytic enzyme activities in different species of fish. In addition, these results may be important for fisheries management issues, such as catch-and-release fishing.

In vitro and in vivo oxidative biotransformation in the West-African dwarf goat (Caprus hircus aegagrus): substrate activities and effects of inducers.

1. Cytochrome P450 activities in vivo and in vitro and enzyme induction by phenobarbital, beta-naphthoflavone, isoniazid and triacetyloleandomycin were investigated in the female dwarf goat. In vivo kinetics of antipyrine, sulphadimidine and caffeine were studied separately and as a combination ("cocktail'). After establishing a lack of interaction between these compounds the effects of the inducing agents were investigated. In vitro, hepatic microsomal enzyme activities and apoprotein levels were determined. 2. In the beta-naphthoflavone treated goat, the microsomal ethoxy-resorufin-O-deethylation rate was markedly increased. beta-naphthoflavone also induced caffeine plasma clearance but did not affect microsomal caffeine 1- and 3-demethylation rates. After phenobarbital treatment, caffeine plasma clearance was also increased. In contrast with beta-naphthoflavone treatment, phenobarbital treatment resulted in an increase of microsomal caffeine 1- and 3-demethylation rates. 3. Goat liver microsomes were able to hydroxylate tolbutamide, predominantly a CYP2C9 activity in man, and debrisoquine, a CYP2D activity in different species. These activities were not affected by either beta-naphthoflavone or phenobarbital. Sulphaphenazole was found to be a more potent inhibitor of tolbutamide hydroxylation than sulphadimethoxine. Quinine was a more potent inhibitor of debrisoquine hydroxylation than was quinidine. 4. As expected, the microsomal aniline-4-hydroxylation rate (CYP2E) was increased after isoniazid treatment. 5. The microsomal testosterone 6 beta-hydroxylation rate (CYP3A) was increased after phenobarbital and triacetyloleandomycin treatment. Antipyrine plasma clearance was also increased after phenobarbital treatment. 6. As cytochrome P450 activities and inducibility in the dwarf goat show many resemblances to those in man, they may be of value as a model for human biotransformation research.

Species differences in the activity of the Na(+)‐Ca2+ exchanger in mammalian cardiac myocytes.

1. Species differences in the activity of the exchanger were evaluated in isolated myocytes from rat, guinea-pig, hamster ventricles and human atria. Fluorescence measurements using fura-2 were carried out in conjunction with the whole-cell patch-clamp technique for simultaneous recording of membrane currents and intracellular Ca2+ concentration. 2. Ca2+ release from sarcoplasmic reticulum (SR) induced either by rapid application of caffeine or by Ca2+ current elicited inward Na(+)-Ca2+ exchange currents (INa-Ca). The magnitude of INa-Ca was largest in hamster, smallest in rat, with guinea-pig and human myocytes having intermediate values. The ratio of caffeine-induced exchanger current densities, normalized with respect to the peak Ca2+ release, was 4:2:1.5:1 for hamster > guinea-pig > or = human > or = rat myocytes. 3. The rates of Ca2+ removal in the presence of caffeine, which reflect primarily the Ca2+ extruding activity of the Na(+)-Ca2+ exchanger, followed the same order of hamster > guinea-pig > or = human > or = rat. 4. The kinetics of INa-Ca vs. Ca2+ transients were different among species. In rat myocytes, the kinetics of the INa-Ca and the Ca2+ transients were similar, with INa-Ca linearly proportional to intracellular Ca2+ concentration ([Ca2+]i). In hamster myocytes, the time course of INa-Ca tracked only the declining phase of the Ca2+ transient with INa-Ca having faster kinetics during the Ca2+ release. These findings suggest that the Ca2+ concentrations in the vicinity of the exchanger were significantly higher than those of the cytosol during Ca2+ release in hamster myocytes. 5. We concluded that there are significant species differences in the exchanger activity of cardiac myocytes, arising from differences in exchanger densities, their modulation and/or their spatial distribution with respect to the ryanodine receptors of cardiac myocytes.