Bacterial community dynamics in surface flow constructed wetlands for the treatment of swine waste

Constructed wetlands are generally used for the removal of waste from contaminated water. In the swine production system, wastes are traditionally flushed into an anaerobic lagoon which is then sprayed on agricultural fields. However, continuous spraying of lagoon wastewater on fields can lead to high N and P accumulations in soil or lead to runoff which may contaminate surface or ground water with pathogens and nutrients. In this study, continuous marsh constructed wetland was used for the removal of contaminants from swine waste. Using pyrosequencing, we assessed bacterial composition within the wetland using principal coordinate analysis (PCoA) which showed that bacterial composition from manure influent and lagoon water were significantly different (P=0.001) from the storage pond to the final effluent. Canonical correspondence analysis (CCA) showed that different bacterial populations were significantly impacted by ammonium--NH4 (P=0.035), phosphate--PO4(3-) (P=0.010), chemical oxygen demand--COD (P=0.0165), total solids--TS (P=0.030), and dissolved solids--DS (P=0.030) removal, with 54% of the removal rate explained by NH4+PO4(3-) according to a partial CCA. Our results showed that different bacterial groups were responsible for the composition of different wetland nutrients and decomposition process. This may be the major reason why most wetlands are very efficient in waste decomposition.

Emerging role for αB-crystallin as a therapeutic agent: pros and cons

HSPB5 or αB-crystallin (αBC) is a major protein of the vertebrate eye lens belonging to the small heat-shock protein family of proteins that respond to various stressful conditions. αBC also is found outside the lens in various non-ocular tissues and acts as a molecular chaperone by preventing aggregation of proteins, inhibits apoptosis and inflammation, and maintains cytoskeletal architecture. The αBC protein is phosphorylated on three serine residues S59, S45, and S19, and several functions of αBC are modulated by phosphorylation. Numerous studies have revealed the upregulation of αBC in pathological conditions such as neurodegenerative diseases, cancers, diabetes, retinal diseases, cataracts, ischemia/repurfusion, aging, and others. However, it is unknown whether the up-regulation of αBC is causative or protective for these pathological conditions. Although αBC has been shown to provide a protective effect in neurodegenerative diseases, inflammation, diabetes, and retinal diseases, other studies have described a deleterious role of αBC in cancers and pulmonary fibrosis. The therapeutic potential of αBC alone or in combination with αA-crystallin has been reported. Acetylated αBC peptides have been shown to be more potent than native αBC for chaperone as well as therapeutic activities using both in vitro and in vivo models. Further, for efficient delivery of α BC into cells, carrier molecules such as polylacticcoglycolic acid, polycaprolactone and cell penetration peptides have been used. In this review, we have summarized current data from emerging and exciting studies of the therapeutic strategies of α BC and α BC peptides and the efficient delivery strategies of these proteins in various disease models, including neurodegenerative diseases, retinal diseases, platelet aggregation, inflammation, and ischemia.

Thermal deoxygenation causes photoluminescence shift from UV to blue region in lyophilized graphene oxide

Lyophilized graphene oxide (GO) was thermally exfoliated in stages at predefined temperatures up to 400 °C and the photoluminescence (PL) study of GO and thermally reduced GO (TGO) was carried out at each step.

Association of G>A transition in exon-1 of alpha crystallin gene in age-related cataracts

Aim

To identify the presence of a known or novel mutation/SNP in Exon-1 (ex-1) of alpha crystallin (CRYAA) gene in different types of age-related cataract (ARC) patients.

Materials and Methods

Single strand Conformation Polymorphism (SSCP) analysis was carried for the detection of single nucleotide polymorphism (SNP) in ex-1 of alpha crystallin (CRYAA) gene which was confirmed by sequencing.

Results

The SSCP analysis of ex-1 of CRYAA gene revealed mobility shift in patients and controls, which was due to G>A transition at 6^th position in exon-1 of CRYAA gene. All the three genotypes, GG, AA and GA, were detected in patients and controls indicating that G>A substitution is polymorphic. The analysis showed significant risk for heterozygotes (GA) as compared to pooled frequencies of homozygotes (GG + AA), which was 1.81 times for all the types of cataracts in general and 2.5 times for Nuclear Cataract and twice for Cortical Cataract.

Conclusion

The GA heterozygotes were at higher risk for developing NC and CC types of cataracts, where as the GG homozygotes for MT and AA homozygotes for PSC types were at risk. To our knowledge, an association of G>A transition found in ex-1 of CRYAA gene with ARC, with differential risk of genotypes for individual type of cataracts has not been reported previously.

Effect of polyaluminium chloride on phosphorus removal in constructed wetlands treated with swine wastewater

Total phosphorus (TP) removal in aged constructed wetlands poses a challenge, especially when treated with swine wastewater with high concentrations of phosphorus (P). Our earlier studies with anaerobic lagoon swine wastewater treatment in constructed wetlands showed a decline in P removal (45-22%) with increased years of operation. These particular wetlands have been treated with swine wastewater every year since the first application in 1997. Preliminary lab-scale studies were conducted to evaluate the efficiency of polyaluminium chloride (PAC) in the removal of phosphate-P (PO4-P) from swine wastewater. The experimental objective was to increase the phosphorus treatment efficiency in constructed wetland by adding PAC as a precipitating agent. PAC was added by continuous injection to each wetland system at a rate of 3 L day(-1) (1:5 dilution of concentrated PAC). Swine wastewater was added from an anaerobic lagoon to four constructed wetland cells (11m wide x 40m long) at TP loads of 5.4-6.1 kg ha(-1) day(-1) in two experimental periods, September to November of 2008 and 2009. Treatment efficiency of two wetland systems: marsh-pond-marsh (M-P-M) and continuous marsh (CM) was compared. The wetlands were planted with cattails (Typha latifolia L.) and bulrushes (Scirpus americanus). In 2008, PAC treatment showed an increase of 27.5 and 40.8% of TP removal over control in M-P-M and CM respectively. Similar trend was also observed in the following year. PAC as a flocculant and precipitating agent showed potential to enhance TP removal in constructed wetlands treated with swine wastewater.

Sorption and desorption of ammonium by zeolite: Batch and column studies

The major objective of this research was to investigate the efficiency of zeolite in the removal of NH(4)-N from swine wastewater and desorption of the sorbed NH(4)-N from the zeolite saturated with N. Sorption experiments were conducted on the sorbents, zeolites I, II and III. Zeolites II and III which are natural and unmodified, showed better sorption (4400-4500 mg kg(-1) with 500 mg L(-1) feed concentration) compared to Zeolite I (3053 ± 127 mg kg(-1) with 500 mg L(-1) feed concentration), which is a surfactant modified zeolite. Freundlich and Langmuir isotherms were plotted from the sorption experimental data. Column studies indicated that, columns with flow rates of 2 and 3 mL min(-1), reached the breakthrough point within about 100 h. The possibility of regeneration of the column material was investigated by flushing the column with 0.1 N HCl. The results from this experiment showed that even after desorption with DI water for more than 250 h, considerable amount of N was still available in the column that was available for desorption by 0.1 N HCl. This confirms that zeolite could be a good substrate for slow N release in soil. The application of Zeolite II for the NH(4)-N removal from swine wastewater supports this observation.

Sorption and desorption of phosphorus by shale: batch and column studies

Constructed wetland systems have gained attention as attractive solutions for wastewater treatment. Wetlands are not efficient to treat wastewater with high concentrations of phosphorus (P). In order to remove high soluble P loads by wetland, sorbent beds can be added prior to the discharge of wastewater into wetlands. Sorption by sorbent materials is identified as a method for trapping excess P in wastewaters. In the present investigation, shale has been identified as a sorbent material for removal of phosphate (PO(4)-P) due to the cost effectiveness, stability and possibility of regeneration. The study focuses on the removal of PO(4)-P from wastewater using shale and the feasibility of using the P-sorbed material as slow-release fertilizer. Phosphorus sorption experiments were conducted by using shale (2 mm and 2-4.7 mm). Results indicate that Shale I (particle size = 2 mm) showed the highest sorption of PO(4)-P (500 +/- 44 mg kg(-1)). Breakthrough point was reached within 10 h in columns with flow rates of 2 and 3 ml min(-1). Lower flow rate of 1 ml min(-1) showed an average residence time of about 2 h while columns with a higher flow rate of 3 ml min(-1) showed a residence time of about 40 minutes. Variation in flow rate did not influence the desorption process. Since very low concentrations of PO(4)-P are released, Shale saturated with PO(4)-P may be used as a slow nutrient release source of P or as a soil amendment. The sorbent can also be regenerated by removing the sorbed PO(4)-P by using 0.1 N HCl.

Comparison of aerated marsh-pond-marsh and continuous marsh constructed wetlands for treating swine wastewater

Increased swine production in North Carolina has resulted in greater waste generation and is demanding some emerging new innovative technologies to effectively treat swine wastewater. One of the cost-effective and passive methods to treat swine wastewater is using constructed wetlands. The objective of this study was to evaluate the N removal under two N loads in 3 different wetland systems: aerated marsh-pond-marsh (M-P-M), aerated marsh-covered pond-marsh (M-FB-M), and continuous marsh (CM) with two days drain and five days flood cycle. Swine wastewater from an anaerobic lagoon was applied to the constructed wetland cells (11 m wide x 40 m length) at two N loading rates of 7 and 12 kg N ha(-1) day(-1)from June to July and August to September 2005, respectively. Weekly inflow and outflow samples were collected for N, P, TS, and COD analysis. Total N reductions (%) at low and high N loading rates were 85.8 and 51.8; 86.3 and 63.3; and 86.2 and 61.8 for M-P-M, M-FB-M, and CM, respectively. Aeration had no significant (P > 0.05) impact on N removal. However, significant (P < 0.05) differences were observed for wetland systems between low and high N loading rates. No difference (P > 0.05) in N reduction was found among wetland systems. Vegetation uptake of N was negligible, ranging from 1.2 to 1.8 %. No significant (P > 0.05) differences in TS and COD removal were observed between the wetland systems.

Under-reporting of road traffic injuries to the police: results from two data sources in urban India

OBJECTIVE

To report the magnitude of under-reporting of road traffic injury (RTI) to the police from population-based and hospital-based data in the urban population of Hyderabad, India.

METHODS

In a cross-sectional population-based survey, 10 459 participants aged 5-49 years (94.3% participation), selected using three-stage systematic cluster sampling, recalled the reporting of non-fatal RTIs to the police in the preceding 12 months and fatal RTIs in the preceding 3 years. In addition, 781 consecutive RTI cases presenting to the emergency department of five hospitals provided information on RTI reporting to the police.

RESULTS

In the population-based study, of those who had non-fatal RTIs and sought outpatient or inpatient services, 2.3% (95% 1.1% to 3.5%) and 17.2% (95% CI 3.5% to 30.9%), respectively, reported the RTI to the police. Of the non-fatal consecutive RTI cases presenting to emergency departments, 24.6% (95% CI 21.3% to 27.8%) reported the RTI to the police. In the population-based study, 77.8% (95% CI 65.1% to 90.5%) of the fatal RTIs were reported to the police, and of the consecutive fatal RTI cases presenting to emergency departments, 98.1% (95% CI 95.5% to 100%) were reported to the police. The major reasons cited for not reporting RTIs to the police were "not necessary to report" and "hit and run case".

CONCLUSIONS

As road safety policies are based on police data in India, these studies highlight serious limitations in estimating the true magnitude of RTIs from these data, indicating the need for better methods for such estimation.

Ammonia Volatilization from Marsh–Pond–Marsh Constructed Wetlands Treating Swine Wastewater

Ammonia (NH3) volatilization is an undesirable mechanism for the removal of nitrogen (N) from wastewater treatment wetlands. To minimize the potential for NH3 volatilization, it is important to determine how wetland design affects NH3 volatilization. The objective of this research was to determine how the presence of a pond section affects NH3 volatilization from constructed wetlands treating wastewater from a confined swine operation. Wastewater was added at different N loads to six constructed wetlands of the marsh-pond-marsh design that were located in Greensboro, North Carolina, USA. A large enclosure was used to measure NH3 volatilization from the marsh and pond sections of each wetland in July and August of 2001. Ammonia volatilized from marsh and pond sections at rates ranging from 5 to 102 mg NH3-N m(-2) h(-1). Pond sections exhibited a significantly greater increase in the rate of NH3 volatilization (p < 0.0001) than did either marsh section as N load increased. At N loads greater than 15 kg ha(-1) d(-1), NH3 volatilization accounted for 23 to 36% of the N load. Furthermore, NH3 volatilization was the dominant (54-79%) N removal mechanism at N loads greater than 15 kg ha(-1) d(-1). Without the pond sections, NH3 volatilization would have been a minor contributor (less than 12%) to the N balance of these wetlands. To minimize NH3 volatilization, continuous marsh systems should be preferred over marsh-pond-marsh systems for the treatment of wastewater from confined animal operations.

The combination of molecular dynamics with crystallography for elucidating protein-ligand interactions: a case study involving peanut lectin complexes with T-antigen and lactose

Peanut lectin binds T-antigen [Galbeta(1-3)GalNAc] with an order of magnitude higher affinity than it binds the disaccharide lactose. The crystal structures of the two complexes indicate that the higher affinity for T-antigen is generated by two water bridges involving the acetamido group. Fresh calorimetric measurements on the two complexes have been carried out in the temperature range 280-313 K. Four sets of nanosecond molecular-dynamics (MD) simulations, two at 293 K and the other two at 313 K, were performed on each of the two complexes. At each temperature, two somewhat different protocols were used to hydrate the complex in the two runs. Two MD runs under slightly different conditions for each complex served to assess the reliability of the approach for exploring protein-ligand interactions. Enthalpies based on static calculations and on MD simulations favour complexation involving T-antigen. The simulations also brought to light ensembles of direct and water-mediated protein-sugar interactions in both the cases. These ensembles provide a qualitative explanation for the temperature dependence of the thermodynamic parameters of peanut lectin-T-antigen interaction and for the results of one of the two mutational studies on the lectin. They also support the earlier conclusion that the increased affinity of peanut lectin for T-antigen compared with that for lactose is primarily caused by additional water bridges involving the acetamido group. The calculations provide a rationale for the observed sugar-binding affinity of one of the two available mutants. Detailed examination of the calculations point to the need for exercising caution in interpreting results of MD simulations: while long simulations are not possible owing to computational reasons, it is desirable to carry out several short simulations with somewhat different initial conditions.

Legume lectin family, the 'natural mutants of the quaternary state', provide insights into the relationship between protein stability and oligomerization

Legume lectins family of proteins, despite having the same 'jelly roll' tertiary structural fold at monomeric level, exhibit considerable variation in their quaternary structure arising out of small changes in their sequence. Nevertheless, their folding behavior and stability correlates very well with their patterns of assembly into dimers and tetramers. A conservation of their fold during evolution, its wide distribution in many protein families together with the availability of structural information on them make them interesting as proteins to explore the effect of inter- versus intra-subunit interactions in the stability of multimeric proteins. Additionally, as 'natural mutants' of quaternary association, proteins of legume lectin family provide interesting paradigms for studies addressing the effect of subunit oligomerization on the stability, folding and function as well as the evolution of multimeric structures.

alphaA- and alphaB-crystallins protect glucose-6-phosphate dehydrogenase against UVB irradiation-induced inactivation

alpha-Crystallin, a major eye lens protein, has been shown to function like a molecular chaperone by suppressing the aggregation of other proteins induced by various stress conditions. Ultraviolet (UV) radiation is known to cause structural and functional alterations in the lens macromolecules. Earlier we observed that exposure of rat lens to in vitro UV radiation led to inactivation of many lens enzymes including glucose-6-phosphate dehydrogenase (G6PD). In the present paper, we show that alpha-crystallin (alphaA and alphaB) protects G6PD from UVB irradiation induced inactivation. While, at 25 degrees C, there was a time-dependent decrease in G6PD activity upon irradiation at 300 nm, at 40 degrees C there was a complete loss of activity within 30 min even without irradiation. The loss of activity of G6PD was prevented significantly, if alphaA- or alphaB-crystallin was present during irradiation. At 25 degrees C, alphaB-crystallin was slightly a better chaperone in protecting G6PD against UVB inactivation. Interestingly, at 40 degrees C, alphaA- and alphaB-crystallins not only prevent the loss of G6PD activity but also protect against UVB inactivation. However, alphaA- and alphaB-crystallins were equally efficient at 40 degrees C in protecting G6PD.

Treatment of swine wastewater in marsh-pond-marsh constructed wetlands

Swine waste is commonly treated in the USA by flushing into an anaerobic lagoon and subsequently applying to land. This natural system type of application has been part of agricultural practice for many years. However, it is currently under scrutiny by regulators. An alternate natural system technology to treat swine wastewater may be constructed wetland. For this study we used four wetland cells (11 m width x 40 m length) with a marsh-pond-marsh design. The marsh sections were planted to cattail (Typha latifolia, L.) and bulrushes (Scirpus americanus). Two cells were loaded with 16 kg N ha(-1) day(-1) with a detention of 21 days. They removed 51% of the added N. Two additional cells were loaded with 32 kg ha(-1) day(-1) with 10.5 days detention. These cells removed only 37% of the added N. However, treatment operations included cold months in which treatment was much less efficient. Removal of N was moderately correlated with the temperature. During the warmer periods removal efficiencies were more consistent with the high removal rates reported for continuous marsh systems--often > than 70%. Phosphorus removal ranged from 30 to 45%. Aquatic macrophytes (plants and floating) assimilated about 320 and 35 kg ha(-1), respectively of N and P.

Isothermal titration calorimetric studies on the binding of deoxytrimannoside derivatives with artocarpin: implications for a deep-seated combining site in lectins

The carbohydrate binding specificity of the seed lectin from Artocarpus integrifolia, artocarpin, has been elucidated by the enzyme-linked lectin absorbent assay [Misquith, S., et al (1994) J. Biol. Chem. 269, 30393-30401], wherein it was demonstrated to be a Man/Glc specific lectin with high affinity for the trisaccharide present in the core of all N-linked oligosaccharide chains of glycoproteins. As a consequence of this characterization, the binding epitopes of this trisaccharide, 3, 6-di(alpha-D-mannopyranosyl)-D-mannose, for artocarpin were investigated by isothermal titration calorimetry using its monodeoxy as well as Glc and Gal analogues. The thermodynamic data presented here implicate 2-, 3-, 4-, and 6-hydroxyl groups of the alpha(1-3) Man and alpha(1-6) Man residues, and the 2- and 4-OH groups of the central Man residue, in binding to artocarpin. Nevertheless, alpha(1-3) Man is the primary contributor to the binding affinity, unlike other Man/Glc binding lectins which exhibit a preference for alpha(1-6) Man. In addition, unlike the binding reactions of most lectins reported so far, the interaction of mannotriose involves all of its hydroxyl groups with the combining site of the lectin. Moreover, the free energy and enthalpy contributions to binding of individual hydroxyl groups of the trimannoside estimated from the corresponding monodeoxy analogues show nonlinearity, suggesting differential contributions of the solvent and protein to the thermodynamics of binding of the analogues. Thus, this study not only provides evidence for the extended site recognition of artocarpin for the trimannoside epitope but also suggests that its combining site is best described as a deep cleft as opposed to shallow indentations implicated in other lectins.

Temperature-dependent chaperone activity and structural properties of human alphaA- and alphaB-crystallins

The chaperone activity and biophysical properties of recombinant human alphaA- and alphaB-crystallins were studied by light scattering and spectroscopic methods. While the chaperone function of alphaA-crystallin markedly improves with an increase in temperature, the activity of alphaB homopolymer appears to change very little upon heating. Compared with alphaB-crystallin, the alphaA-homopolymer is markedly less active at low temperatures, but becomes a more active species at high temperatures. At physiologically relevant temperatures, the alphaB homopolymer appears to be modestly (two times or less) more potent chaperone than alphaA homopolymer. In contrast to very similar thermotropic changes in the secondary structure of both homopolymers, alphaA- and alphaB-crystallins markedly differ with respect to the temperature-dependent surface hydrophobicity profiles. Upon heating, alphaA-crystallin undergoes a conformational transition resulting in the exposure of additional hydrophobic sites, whereas no such transition occurs for alphaB-crystallin. The correlation between temperature-dependent changes in the chaperone activity and hydrophobicity properties of the individual homopolymers supports the view that the chaperone activity of alpha-crystallin is dependent on the presence of surface-exposed hydrophobic patches. However, the present data also show that the surface hydrophobicity is not the sole determinant of the chaperone function of alpha-crystallin.

Chemical investigation of Mycale mytilorum and a study on toxicity and antidiabetic activity of 5-octadecylpyrrole-2-carboxaldehyde

Chemical investigation of Mycale mytilorum afforded four new and two known compounds, of which 5-octadecylpyrrole-2-carboxaldehyde (1) and (6'Z)-5-(6'-heneicosenyl) pyrrole-2-carboxaldehyde (2, congeners of alkylpyrrole carboxadehyde), (2S,3R,4E)-1,3-dihydroxy-2-[(heneicosanoyl) amino]-4-heneicosene (5, sphingolipid) and 2-methyl-3-(4,5,7-trihydroxy-8-hydroxy-methyltetrahydro-6H-4-py ranyl)-2-propenoic acid (6, tetrahydropyran derivative) are new, and batylalcohol (3) and p-hydroxyphenylacetic acid (4) are known. The toxicity and antidiabetic activity of 5-octadecylpyrrole-2-carboxaldehyde were evaluated for the first time. Also, compounds 1, 2, 5 and 6 were studied for the antibacterial, antifungal and antiviral activity.

Linear free-energy model description of the conformational stability of uracil-DNA glycosylase inhibitor A thermodynamic characterization of interaction with denaturant and cold denaturation

The equilibrium unfolding of uracil DNA glycosylase inhibitor (Ugi), a small acidic protein of molecular mass 9474 Da, has been studied by a combination of thermal-induced and guanidine hydrochloride (GdnCl)-induced denaturation. The analysis of the denaturation data provides a measure of the changes in conformational free energy, enthalpy, entropy and heat capacity DeltaCp that accompany the equilibrium unfolding of Ugi over a wide range of temperature and GdnCl concentration. The unfolding of Ugi is a simple two-state, reversible process. The protein undergoes both low-temperature and high-temperature unfolding even in the absence of GdnCl but more so in the presence of denaturant. The data are consistent with the linear free-energy model and with a temperature independent DeltaCp over the large temperature range of unfolding. The small DeltaCp (6.52 kJ.mol-1.K-1) for the unfolding of Ugi, is perhaps a reflection of a relatively small, buried hydrophobic core in the folded form of this small monomeric protein. Despite a relatively low value of DeltaG(H2O), 7.40 kJ.mol-1 at pH 8.3, Ugi displays considerable stability with the temperature of maximum stability being 301.6 K.

Thermal stability and mode of oligomerization of the tetrameric peanut agglutinin: a differential scanning calorimetry study

Peanut agglutinin is a homotetrameric legume lectin. The crystal structure of peanut agglutinin shows that the four subunits associate in an unusual manner, giving rise to open quaternary structure [Banarjee, R., et al. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 227-231]. The thermal unfolding of peanut agglutinin has been characterized by differential scanning calorimetry and gel filtration to elucidate its thermal stability and its mode of oligomerization. The unfolding process is reversible and could be described by a three-state model with two transitions occurring at around 331 and 336 K. For the tetramer, the ratio of DeltaHc/DeltaHv for the first transition is close to 4 and for the second transition is close to 0.25, suggesting that 4 and 0.25 cooperative unit(s) of the tetramer are involved in the first and second transitions, respectively. The agreement between the model-independent DeltaHv(S) determined from the values of the temperatures of the peak maximum (Tp1) with the protein concentration with the values of DeltaHv obtained from the fit of the data to the transition confirms that the first peak is associated with the dissociation of peanut agglutinin tetramers (A4) to "folded" monomers (4A), whereas the second peak describes the unfolding (4U) of these monomers. The overall process for the thermal unfolding of peanut agglutinin could therefore be summarized as A4 <==> 4A <==> 4U. Gel filtration studies confirm this process, as peanut agglutinin elutes as a tetramer up to 50 degrees C, and at and above 56 degrees C (Tm of first transition), it elutes at a position commensurate with that of the folded monomer of peanut agglutinin. The unfolding behavior of peanut agglutinin in the presence of saturating amounts of carbohydrate ligands is similar to that observed for the unligated form. The temperature of maximal stability of the peanut agglutinin tetramer at pH 7.4 is calculated to be around 33 degrees C with a maximal free energy of stabilization of 8.70 kcal/mol. The results demonstrate that unfolding of peanut agglutinin goes through two distinct phases with folded monomer being the intermediate.

Protection against UVB inactivation (in vitro) of rat lens enzymes by natural antioxidants

Oxidative damage, through increased production of free radicals, is believed to be involved in UV-induced cataractogenesis (eye lens opacification). The possibility of UVB radiation causing damage to important lenticular enzymes was assessed by irradiating 3 months old rat lenses (in RPMI-1640 medium) at 300 nm (100 microWcm(-2)) for 24 h, in the absence and presence of ascorbic acid, alpha-tocopherol acetate and beta-carotene. UVB irradiation resulted in decreased activities of hexokinase, glucose-6-phosphate dehydrogenase, aldose reductase, and Na, K- ATPase by 42, 40, 44 and 57% respectively. While endopeptidase activity (229%) and lipid peroxidation (156%) were increased, isocitrate dehydrogenase activity was not altered on irradiation. In the presence of externally added ascorbic acid, tocopherol and beta-carotene (separately) to the medium, the changes in enzyme activities (except endopeptidase) and increased lipid peroxidation, due to UVB exposure, were prevented. These results suggest that UVB radiation exerts oxidative damage on lens enzymes and antioxidants were protective against this damage.

Molten globule-like state of peanut lectin monomer retains its carbohydrate specificity. Implications in protein folding and legume lectin oligomerization

A central question in biological chemistry is the minimal structural requirement of a protein that would determine its specificity and activity, the underlying basis being the importance of the entire structural element of a protein with regards to its activity vis à vis the overall integrity and stability of the protein. Although there are many reports on the characterization of protein folding/unfolding intermediates, with considerable secondary structural elements but substantial loss of tertiary structure, none of them have been reported to show any activity toward their respective ligands. This may be a result of the conditions under which such intermediates have been isolated or due to the importance of specific structural elements for the activity. In this paper we report such an intermediate in the unfolding of peanut agglutinin that seems to retain, to a considerable degree, its carbohydrate binding specificity and activity. This result has significant implications on the molten globule state during the folding pathway(s) of proteins in general and the quaternary association in legume lectins in particular, where precise subunit topology is required for their biologic activities.

Thermodynamic characterization of the conformational stability of the homodimeric protein, pea lectin

The conformational stability of the homodimeric pea lectin was determined by both isothermal urea-induced and thermal denaturation in the absence and presence of urea. The denaturation profiles were analyzed to obtain the thermodynamic parameters associated with the unfolding of the protein. The data not only conform to the simple A2 if 2U model of unfolding but also are well described by the linear extrapolation model for the nature of denaturant-protein interactions. In addition, both the conformational stability (DeltaGs) and the DeltaCp for the protein unfolding is quite high, at about 18.79 kcal/mol and 5.32 kcal/(mol K), respectively, which may be a reflection of the relatively larger size of the dimeric molecule (Mr 49 000) and, perhaps, a consequent larger buried hydrophobic core in the folded protein. The simple two-state (A2 if 2U) nature of the unfolding process, with the absence of any monomeric intermediate, suggests that the quaternary interactions alone may contribute significantly to the conformational stability of the oligomer-a point that may be general to many oligomeric proteins.

Antibacterials and antimycotics: Part 1: Synthesis and activity of 2-pyrazoline derivatives

A series of 3-styryl-1,5-diphenyl and 5-styryl-1,3-diphenyl 2-pyrazolines of different substitutions has been synthesized by condensation of substituted alpha,beta-unsaturated ketones with phenylhydrazine hydrochloride in presence of catalytic amount of concentrated HCl. Compounds in the 3-styryl series had OMe, NMe2, NO2, OH and isopropyl substituents and those in the 5-styryl series had OMe, NMe2 and NOs. The 3-styryl-1,5-diphenyl compounds showed little variation in antibacterial activity towards gram-positive and gram-negative bacteria in terms of geometric mean minimum inhibitory concentrations (MIC). The 4',4"-NMe2, 4',4"-NO2 and 4',4"-OMe compounds were found to possess the highest activity in the series. The 5-styryl-1,3-diphenyl series showed lower activities than the 3-styryl series. The in vitro antimycotic activity of the 4',4"-OH and 2',2"-OH substituted compounds showed good activity than the other molecules in the two series.

Synergistic effect of UVB radiation and age on HMPS enzymes in rat lens homogenate

The behaviour of rat lenticular enzymes, glucose-6-phosphate dehydrogenase (G6PD, EC: 1.1.1.49) and 6-phosphogluconate dehydrogenase (6PGD, EC: 1.1.1.44) as a function of age and UVB irradiation (in vitro) was investigated by irradiating the lens homogenate from 3- and 12-month-old rats at 300 nm (100 microW cm-2). In the 3-month-old group the specific activities of G6PD and 6PGD were reduced by 26% and 42%, respectively, after 24 h of irradiation, whereas in the 12-month-old group the decrease was 38% and 49% respectively, which suggests that the susceptibility of HMPS enzymes to UVB damage is higher in older lenses. The decrease in specific activity was associated with a change in apparent K(m) and Vmax (marginal in 3 months and significant in 12 months) of these enzymes due to UVB irradiation. UVB irradiation also decreased the levels of NADPH and NADPH/NADP ratio. These changes, altered activities of G6PD and 6PGD and altered levels of NADPH, may in turn have a bearing on lens transparency.

UVB irradiation alters the activities and kinetic properties of the enzymes of energy metabolism in rat lens during aging

Ultraviolet (UV) radiation is one of the major risk factors of cataract (loss of eye-lens transparency). The influence of UVB radiation (300 nm; 100 microW cm-2) on the activity and apparent kinetic constants (Km and Vmax) of rat lens hexokinase (HK;EC 2.7.1.1), phosphofructokinase (PFK; EC 2.7.1.11), isocitrate dehydrogenase (ICDH; EC 1.1.1.41) and malate dehydrogenase (MDH; EC 1.1.1.37) of energy metabolism has been investigated by irradiating the lens homogenate of three- and 12-month-old rats. In the three-month-old group specific activities of HK and PFK are reduced by 56 and 43%, respectively, and there is no change in ICDH and MDH activities after a 24 h exposure. On the other hand, in the 12-month-old group the decreases are 72, 71, 24 and 16% for HK, PFK, ICDH and MDH, respectively. UVB irradiation increases the apparent Km of HK and PFK (in both age groups), whereas the Km of ICDH and MDH is not altered. While the decrease in Vmax of these enzymes due to UVB exposure is only marginal in three-month-old rats, it is more pronounced (significant) in 12-month-old rats. A similar decrease in enzyme activities of HK and PFK is also observed upon UVB exposure of the intact rat lens. The photoinduced changes in energy metabolism may in turn have a bearing on lens transparency, particularly at an older age.

Biotechniques for improving acid aluminum tolerance in alfalfa

Alfalfa (Medicago sativa L.), cultivars ARC, Regen Y and Saranac were selected in vitro in a recently developed acid/aluminum toxic media. The new media produced higher initiation rates and higher fresh callus weights than those obtainable with the media described by Meredith and Connor for the selection of aluminum resistant variants in Nicotiana plumbaginofolia. Both rescue and direct initiation yielded adequate amounts of healthy callus for the initiation of embryogenesis. The toxic effect of the acid/aluminum media is expressed in both the percent of explants initiating callus and in the fresh-weights obtained during initiation and two subsequent subcultures.

Longissimus muscle quality, palatability and connective tissue histological characteristics of bulls and steers fed different energy levels and slaughtered at four ages

One hundred forty-four Angus male calves were assigned to one of five slaughter-age groups: 9, 12, 15, 18 and 24 mo of age. After weaning, one-half of the calves within slaughter age were castrated. One-half of the 12-, 15-, 18- and 24-mo age groups of each sex were further randomly allotted to a high-energy (HE) or low-energy (LE) finishing diet. Eight bulls and eight steers assigned to the 9-mo slaughter group were fed the HE diet only. Samples from the longissimus muscle (LM) were taken at the 12th rib for histological evaluations of fat deposits. Thin sections from the LM at the 11th rib were stained for lipid, collagen and elastin. Steaks from the LM were cooked and evaluated by a sensory panel and sheared by a Warner-Bratzler shear (WBS) device. The 9-10-11th rib sections were separated into muscle, fat and bone. Collagen, elastin and collagen solubility were determined chemically. Bulls had heavier carcasses, less fat and lower sensory scores for tenderness and juiciness than steers. Steers fed the HE diet had lower WBS values than bulls on either diet. Cooking losses were higher for bulls at 12, 18 and 24 mo than for steers. Histological evaluation showed that collagen content was higher for bulls than for steers and higher for cattle fed the LE diet than those fed the HE diet. Among cattle on the HE diet, the 9-mo cattle had more collagen than all older groups. Neither sex nor diet had an effect on elastin content shown by histological evaluation, but 12-mo cattle had the most elastin and the 15- and 18-mo cattle had the least elastin. Collagen content determined by chemical analysis was not affected by sex, diet or slaughter age. Correlation coefficients among histologically and chemically evaluated collagen and elastin and meat traits were too low to be of practical importance. The time-intensive histological techniques used in our study provided little additional information over that obtained from visually evaluated or chemically measured meat traits.