Crustacean hyperglycemic hormones of two cold water crab species, Chionoecetes opilio and C. japonicus: isolation of cDNA sequences and localization of CHH neuropeptide in eyestalk ganglia.

Crustacean hyperglycemic hormone (CHH) is primarily known for its prototypical function in hyperglycemia which is induced by the release of CHH. The CHH release takes place as an adaptive response to the energy demands of the animals experiencing stressful environmental, physiological or behavioral conditions. Although >63 decapod CHH nucleotide sequences are known (GenBank), the majority of them is garnered from the species inhabiting shallow and warm water. In order to understand the adaptive role of CHH in Chionoecetes opilio and Chionoecetes japonicus inhabiting deep water environments, we first aimed for the isolation of the full-length cDNA sequence of CHH from the eyestalk ganglia of C. opilio (ChoCHH) and C. japonicus (ChjCHH) using degenerate PCR and 5' and 3' RACE. Cho- and ChjCHH cDNA sequences are identical in 5' UTR and ORF with 100% sequence identity of the putative 138aa of preproCHHs. The length of 3' UTR ChjCHH cDNA sequence is 39 nucleotides shorter than that of ChoCHH. This is the first report in decapod crustaceans that two different species have the identical sequence of CHH. ChoCHH expression increases during embryogenesis of C. opilio and is significantly higher in adult males and females. C. japonicus males have slightly higher ChjCHH expression than C. opilio males, but no statistical difference. In both species, the immunostaining intensity of CHH is stronger in the sinus gland than that of X-organ cells. Future studies will enable us to gain better understanding of the comparative metabolic physiology and endocrinology of cold, deep water species of Chionoecetes spp.

'1-8 interferon inducible gene family': putative colon carcinoma-associated antigens.

D(b-/-)xbeta2 microglobulin (beta2m) null mice transgenic for a chimeric HLA-A2.1/D(b)-beta2m single chain (HHD mice) are an effective biological tool to evaluate the antitumour cytotoxic T-lymphocyte response of known major histocompatibility-restricted peptide tumour-associated antigens, and to screen for putative unknown novel peptides. We utilised HHD lymphocytes to identify immunodominant epitopes of colon carcinoma overexpressed genes. We screened with HHD-derived lymphocytes over 500 HLA-A2.1-restricted peptides derived from colon carcinoma overexpressed genes. This procedure culminated in the identification of seven immunogenic peptides, three of these were derived from the 'human 1-8D gene from interferon inducible gene' (1-8D). The 1-8D gene was shown to be overexpressed in fresh tumour samples. The three 1-8D peptides were both antigenic and immunogenic in the HHD mice. The peptides induce cytotoxic T lymphocytes that were able to kill a colon carcinoma cell line HCT/HHD, in vitro and retard its growth in vivo. One of the peptides shared by all the 1-8 gene family primed efficiently normal human cytotoxic T lymphocyte precursors. These results highlight the 1-8D gene and its homologues as putative immunodominant tumour-associated antigens of colon carcinoma.

Kinetic studies of attachment and detachment of microbial cells from soil.

A mathematical model was developed to describe the kinetics of cell attachment and detachment from soil. Soil-column experiments were performed to evaluate the model parameters. Pseudomonas putida G7 capable of degrading naphthalene was used as a model microorganism. A sediment sample taken from an uncontaminated area near a coal tar waste site in upstate New York, USA was used as a test soil. The kinetics of cell attachment and detachment from the model soil could be described by the developed first-order model. The equilibrium constant of attachment (11.4 ml g(-1)), the rate coefficient of cell attachment (0.299 ml g(-1) min(-1) and the rate coefficient of cell detachment (0.0263 min(-1)) were determined from the soil-column experiment. The equilibrium constant of attachment determined in this study (11.4 ml g(-1)) was within the range of those reported in the literature for bacterial attachment to soil (0.55 to 12.6 ml g(-1)). The kinetic model succesfully predicted the data of batch experiment for cell attachment and detachment soil.

Biodegradation of toluene by a lab-scale biofilter inoculated with Pseudomonas putida DK-1.

The biodegradation of toluene by biofiltration inoculated with Pseudomonas putida DK-1 was investigated with variation of the several environmental parameters, such as temperature, bed length, gas flow rate and optimal humidity zone. The optimal temperature range to treat toluene gas was found to be 32-35 degrees C. Increasing the gas flow rate showed an inverse effect on the elimination capacity and the removal efficiency. The optimal gas flow rate was obtained at 65 ml min(-1) from the relation between the removal efficiency and the elimination capacity. The biodegradation rate of the toluene with respect to the bed lengths (3, 6, 9, 12 and 15 cm) increased up to 80 h but was then independent of the bed lengths after 80 h except for the 3 cm bed length. The elimination capacity was improved by about 70% compared with that reported in other literature and was also in agreement with theoretical models.

Phenanthrene desorption from soil in the presence of bacterial extracellular polymer: observations and model predictions of dynamic behavior.

The extracellular polymer produced by a bacterium isolated from soil was employed in laboratory studies of desorption of a model polynuelear aromatic hydrocarbon (PAH), phenanthrene. The experimental results show that the selected extracellular polymer enhances the extent of release of soil-bound phenanthrene. A kinetic model was developed as an aid in interpreting the alterations in phenanthrene desorption resulting from polymer addition. The model employs a statistical gamma (gamma) distribution to describe spectrum of rate constants for transfer of phenanthrene from soil to water, and assumes instantaneous binding of phenanthrene to polymer and of polymer to the test soil. The relevant distribution coefficients and statistical parameters of the gamma distribution needed for the model were evaluated in independent experiments. Using these measured parameters, the model provides a satisfactory independent prediction of phenanthrene release from soil to aqueous phase at two test polymer concentrations, 50 mg TOC/L and 100 mg TOC/L. The success of the independent model predictions suggests a mechanism for the influence of extracellular polymer on phenanthrene desorption. The intrinsic, soil-specific, rate constants for solid to solution transfer of phenanthrene do not appear to be changed by bacterial polymer. Instead, polymer binding of phenanthrene in solution results in an increase in driving force for desorption by decreasing the solution concentration of the free, unbound, PAH molecule.

Independent prediction of naphthalene transport and biodegradation in soil with a mathematical model.

Experiments were performed to test the ability of a mathematical model to predict naphthalene transport and biodegradation. Pseudomonas putida G7, a model bacterial strain capable of degrading naphthalene, was added to a column packed with the soil that had been pre-equilibrated with naphthalene. Model prediction for transport and degradation were based on predetermined parameters that described naphthalene desorption kinetics and the utilization of naphthalene by the test bacterium. However, initial prediction for naphthalene biodegradation was high, and the formation of cell aggregates is advanced as a plausible explanation. Access of substrate to cells in the interior of an aggregate would be restricted. When the numerical simulation was conducted with a factor to account for cell aggregation, it successfully described the experimental data. Thus, with a single adjustable parameter (an average effectiveness factor), the model predicted macroscopic responses of naphthalene in soil-columns where naphthalene was subject to transport and biodegradation.

Growth kinetics of Pseudomonas putida G7 on naphthalene and occurrence of naphthalene toxicity during nutrient deprivation.

The objectives of this work were (1) to demonstrate how the chemostat approach could be modified to allow determination of kinetic parameters for a sparingly soluble, volatile substrate such as naphthalene and (2) to examine the influence of the interactions of various nutrients on possible growth-inhibitory effects of naphthalene. Pseudomonas putida G7 was used as a model naphthalene-degrading microorganism. Naphthalene was found to be toxic to P. putida G7 in the absence of a nitrogen source or oxygen. The death rate of cells grown on minimal medium plus naphthalene and then exposed to naphthalene under anoxic conditions was higher than that observed under oxic conditions in the absence of a nitrogen source. The presence of necessary nutrients for the biodegradation of PAH compounds is indicated to be important for the survival of microorganisms that are capable of PAH degradation. The amounts of ammonia and oxygen necessary for naphthalene biodegradation and for suppression of naphthalene toxicity were calculated from growth yield coefficients. A chemostat culture of P. putida G7 using naphthalene as a carbon and energy source was accomplished by using a feed augmented with a methanol solution of naphthalene so as to provide sufficient growth to allow accurate evaluation of kinetic parameters. When naphthalene was the growth-limiting substrate, the degradation of naphthalene followed Monod kinetics. Maximum specific growth rate (micrometer) and Monod constant (Ks) were 0.627 +/- 0.007 h-1 and 0.234 +/- 0.0185 mg/L, respectively. The evaluation of biodegradation parameters will allow a mathematical model to be applied to predict the long-term behavior of PAH compounds in soil when combined with PAH transport parameters.

Microscale-based modeling of polynuclear aromatic hydrocarbon transport and biodegradation in soil.

A mathematical model to describe polynuclear aromatic hydrocarbon (PAH) desorption, transport, and biodegradation in saturated soil was constructed by describing kinetics at a microscopic level and incorporating this description into macroscale transport equations. This approach is novel in that the macroscale predictions are made independently from a knowledge of microscale kinetics and macroscopic fluid dynamics and no adjustable parameters are used to fit the macroscopic response. It was assumed that soil organic matter, the principal site of PAH sorption, was composed of a continuum of compartments with a gamma distribution of desorption rate coefficients. The mass transport of substrates and microorganisms in a mesopore was described by diffusion and that in a macropore by one-dimensional advection and dispersion. Naphthalene was considered as a test PAH compound for initial model simulations. Three mechanisms of naphthalene biodegradation were considered: growth-associated degradation as a carbon and energy source for microbial growth; degradation for maintenance energy; and growth-independent degradation. The Haldane modification of the Monod equation was used to describe microbial growth rates and to account for possible growth inhibition by naphthalene. Multisubstrate interactions were considered and described with a noninteractive model for specific growth rates. The sensitivity of selected model parameters was analyzed under conditions when naphthalene was the sole growth-rate-limiting substrate. The time necessary to achieve a specific degree of naphthalene biodegradation was found to be proportional to the initial concentration of naphthalene in soil organic matter. The biodegradation rate of naphthalene increased when the sorption equilibrium constant of naphthalene was reduced. The presence of an alternative carbon source inhibited naphthalene biodegradation in spite of the calculated increase in biomass. (c) 1996 John Wiley & Sons, Inc.

[Enzymic spectrum of preneoplastic and neoplastic changes induced by 1,2-dimethylhydrazine in mouse kidneys]. / Fermentny i spektr preneoplasticheskikh i neoplasticheksikh izmeneni i vyzyvaemykh 1,2-dimetilgidrazinom v pochkakh myshe i.

Mouse renal cell tumors (RCT) were induced in male CBA male mice by 5 subcutaneous injections of 8 mg 1,2-dimethylhydrazine (DMH) per kg body weight once a week. After a lag period of two years the kidneys were removed, and serial cryostat sections of the kidneys were histochemically analyzed for the following parameters: Glycogen content, basophilia, and activities of glycogen synthase (SYN), glycogen phosphorylase (PHO), glucose-6-phosphatase (G6Pase), glucose-6-phosphate dehydrogenase (G6PDH), hexokinase (HK), pyruvate kinase (PK), lactate dehydrogenase (LDH), malic enzyme (ME), succinate dehydrogenase (SDH), alkaline phosphatase (ALPase) and glutamyl-transpeptidase (GGT). RCT displayed the same histochemical profile irrespective of their size and growth pattern. In comparison with normal kidney epithelium, the neoplastic cells exhibited elevated activities of enzymes for glycolysis (HK, PK LDH) and the pentose phosphate pathway (G6PDH) while negative G6Pase and low SDH activity were observed in these cells. The majority of RCT showed high PHO activity and weak staining for SYN. Activities of ALPase and GGT were negative in most of the RCT. Giant cells were detected in some large RCT. Higher activities of glycolytic and mitochondrial enzymes and G6PDH were found in giant cells compared with other tumor cells. Tubular preneoplastic lesions were similar to neoplastic lesions in morphological and histochemical characteristics. The present study revealed that a markedly elevated capacity for glycolysis and the pentose phosphate pathway occurred in renal cell tumors in mice. A similar histochemical pattern in the few preneoplastic tubular lesions observed suggests that these metabolic aberrations emerge early in carcinogenesis, but studies on earlier stages of renal carcinogenesis are needed to substantiate this assumption.