Microorganisms and plant of Autonomous Biological Systems (ABS) samples

Distribution of microorganisms and cellular structure of an Autonomous Biological Systems (ABS) were studied with a special attention to the effect of space environments. Viable cell densities measured by the direct fluorescence microscopic method were in the order of 10(5) cells/ml for fractions 1 (upper suspension) and 2 (lower suspension), and 10(6) cells/ml for fraction 3 (sediments). These values were 10 to 100 times larger than the values obtained by the classical colony forming unit method. No difference between flight and ground samples was observed in the vertical distribution of viable microorganisms when fractionation and analysis were carried out after recovery. Intracellular distribution of chloroplasts in higher green plants, Ceratophyllum demersum, of flight samples was disturbed after 10 days of flight (24hrs/day light on). After 4 months of flight (Mir/STS-79/81) with 24 hrs light on, Ceratophyllum demersum was completely disintegrated. On the other hand, in the second 4-months-flight experiment with 16 hrs/day light on, Ceratophyllum demersum was only slightly deteriorated.

Immunological detection of fructated proteins in vitro and in vivo

An antibody has been raised against fructated lysine in proteins by immunizing fructated lysine-conjugated ovalbumin in rabbits. The affinity-purified antibody specifically recognized proteins incubated with fructose but not with other reducing sugars such as glucose, galactose or ribose, as judged by immunoblotting and ELISA techniques. Competitive binding to this antibody was observed specifically by fructated lysine but not by glucated lysine, glucose, fructose or lysine. The antibody binds specifically to fructated lysine residues in the protein but not to borohydride-reduced material or advanced glycation end products, indicating that the antibody recognizes only the reducing, carbonyl-containing forms produced in the early stage of the fructation reaction. When BSA was incubated with various concentrations of fructose, the reactivity of the antibody increased in a dose- and time-dependent manner. When soluble proteins prepared from either normal or streptozotocin-induced diabetic rat eyes were analysed by ELISA with this antibody, an increase in the reactive components was observed as a function of aging as well as under diabetic conditions. Western blotting analysis showed that lens crystallin reacted highly with this antibody. Because fructose is biosynthesized largely through the polyol pathway, which is enhanced under diabetic conditions, and lens is known to have a high activity of enzymes in this pathway, this antibody is capable of recognizing fructated proteins in vivo. Thus it is a potentially useful tool for investigating two major issues that seem to be involved in diabetic complications, namely the glycation reaction and the polyol pathway.

[A pediatric case of myeloperoxidase-antineutrophil cytoplasmic (ANCA)-related crescentic glomerulonephritis associated with propylthiouracil treatment for Graves' disease]

We treated a 13-year-old girl who developed myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-related crescentic glomerulonephritis (GN) during propylthiouracil (PTU) treatment for Graves' disease. MPO-ANCA-related crescentic GN during PTU therapy has been described previously in only one recent report of 2 children. We report this case here and describe 15 (13 adult cases) more patients with MPO-ANCA-related GN associated with PTU found in a literature review. The mean age at onset was 41.3 years, and the length of PTU administration ranged from 2 weeks to 6 years (mean 3.5 years). Clinical signs and symptoms were hematuria (100%), proteinuria (100%), arthralgia (7 of 16 cases; 43.8%), fever (4 cases; 20.0%), purpura (2 cases; 12.5%), skin ulcer (1 case; 6.3%) and dyspnea (1 case; 6.3%). These patients were treated with steroid (15 cases; 93.8%), cyclophosphamide (8 cases; 50.0%), steroid pulse therapy (4 cases; 25.0%), or plasma exchange (1 case; 6.3%), or were not treated (1 case; 6.3%). Most patients revealed crescentic GN (15 cases; 93.8%) on renal biopsy, while one exhibited mesangial proliferative GN (6.3%). For 2 of the 16 patients (12.5%) irreversible renal dysfunction persisted and hemodialysis was started. Patients with Graves' disease treated with PTU should be observed carefully by urinalysis and monitoring of the serum creatinine level.

Gene duplication and fusion have occurred frequently in the evolution of phosphagen kinases--a two-domain arginine kinase from the clam Pseudocardium sachalinensis

In contrast to the 40 kDa arginine kinases from Molllusca and Arthropoda, the adductor muscle of the marine clam Pseudocardium sachalinensis contains an unusual arginine kinase consisting of an 86 kDa subunit. The cDNA encoding the 86 kDa arginine kinase was amplified by PCR and the cDNA-derived amino acid sequence of 724 residues was determined. The exact molecular mass for the protein was calculated to be 80941 Da. The amino acid sequence clearly indicates that Pseudocardium arginine kinase has a two-domain structure: the first domain residues 1-363 and the second domain 364-724. The two domains, which are separated by an intron of 176 bp in the gene, show 62% amino acid sequence identity. This two-domain arginine kinase from a mollusc represents yet another multiple-domain enzyme observed in the phosphagen kinase enzyme family. Two-domain and three-domain enzymes have been observed in three other diverse invertebrate groups. Thus, it is clear that gene duplication and subsequent fusion have occurred frequently, and likely independently, during the course of the evolution of this enzyme family. Comparison of the amino acid sequence in the GS region (a possible candidate for the guanidine substrate recognition site in the phosphagen kinase family) suggests that the first domain of Pseudocardium arginine kinase might not retain a complete enzyme activity, because the Asp-7 in the GS region, which is assumed to be involved in the recognition of the positive charge of arginine, was replaced by a Gly residue in the first domain.

Histopathological and ultrastructural features of feline hereditary cerebellar cortical atrophy: a novel animal model of human spinocerebellar degeneration

Human spinocerebellar degeneration is one of the intractable diseases. We studied the detailed neuropathology of cats with hereditary cerebellar degeneration obtained from the experimental breeding. The findings included almost total loss of Purkinje cells with an increase in Bergmann's glia in the cerebellar hemisphere, preservation of some Purkinje cells in the vermis and moderate neuronal depletion of the olive nucleus. Cerebellar and pontine nuclei were normal. The cerebrum and spinal cord as well as the peripheral nervous system appeared normal. Electron microscopic examination revealed swelling of the distal dendrites of Purkinje cells in the less-affected nodule of the vermis, and clusters of presynaptic boutons without any synaptic contact in the severely affected folia where Purkinje cell bodies and dendrites disappeared. Prolonged existence of presynapses in the molecular and Purkinje cell layers was confirmed by positive immunoreactivity to anti-synaptophysin. Quantitative analysis using electron microscopy demonstrated an apparent increase in the density and mean size of presynapses in the molecular layer of the severely affected folia. These findings indicate that degeneration of Purkinje cells started at the most distal part of the dendrite in this animal model of cerebellar degeneration, and that presynapses, axon terminals of the granular cells and basket cells can exist for a long time even after complete degeneration of the Purkinje cells. Further investigation of this novel animal model may promote a better understanding of pathogenesis of human hereditary cerebellar degeneration.

A defect in the mitochondrial import of mutant Mn-superoxide dismutase produced in Sf21 cells

Wild-type and several mutant human manganese superoxide dismutases (Mn-SODs) were produced in a baculovirus/insect cell system and characterized. The enzymatic activity of a homogenate of Sf21 cells, infected with baculovirus carrying wild-type Mn-SOD and grown in the conventional medium, was indistinguishable from that of control cells, but was augmented by supplementation with Mn2+. The protein produced was largely imported into the mitochondria, as judged from the enrichment in the mitochondrial fraction, the mobility of the protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the results of N-terminal processing, which was confirmed by sequencing of the purified enzyme. However, a significant amount of precursor was also detected by an antibody raised against the human Mn-SOD signal peptide. While both Mn2+ and Fe3+ stimulated Mn-SOD accumulation within mitochondria, the active form was produced in the presence of submillimolar Mn2+ only. Amino acid substitutions at a signal peptide-cleavage site, His-Ser-Leu4 to Pro-Met-Va14, in the mature Mn-SOD prevented the processing of the precursor protein, and thus resulted in the accumulation of the precursor protein within mitochondria, as judged on immunostaining with an anti-Mn-SOD antibody. Mutant Mn-SODs with a truncated signal peptide or carboxyl region (8, 13, and 42 amino acid residues in the mature form) were barely solubilized, even with a nonionic detergent, and exhibited no activity, suggesting inappropriate folding of these mutant SODs. They were also susceptible to proteolytic degradation, while the wild-type and precursor forms were resistant. Thus, the baculovirus/insect cell expression system appears to be adequate for the analysis of mitochondrial import using intact cells as well as for the large scale production of active Mn-SOD.

P300 and the thought disorder factor extracted by factor-analytic procedures in schizophrenia

BACKGROUND

In order to clarify the clinical significance of P300 as a biologic marker that can reflect schizophrenic symptomatology, many previous studies have evaluated the relationship of P300 with the symptoms on the basis of a positive/negative dichotomy, but yielded inconsistent conclusions. Such a dichotomy has been criticized as being too reductionistic. Recently, most studies with factor-analytic procedures have extracted some symptom factors outside this dichotomy. Therefore, it is important to examine associations of P300 with the symptom factors extracted by these statistical analyses.

METHODS

In the present study, the amplitudes of P300 were measured by using an auditory oddball paradigm for 73 schizophrenics whose psychopathology was assessed with the Positive and Negative Syndrome Scale (PANSS).

RESULTS

The principal component analysis of the PANSS items revealed five factors labeled the thought disorder, negative, hostile/excitable, delusional/hallucinatory, and depressive factors. The score for the thought disorder factor correlated negatively with the amplitude of P300 recorded at Pz T5, and T6, but that for the other factors did not.

CONCLUSIONS

These findings suggest that the reduction of P300 amplitudes recorded at the midline parietal and bilateral temporoparietal regions may be one of the electrophysiologic indices representing the thought disorder clinically observed in schizophrenia.

Ecological cultivation ark (ECA) project--mutation and evolution of micro-organisms in space

Ecological cultivation capsules (ECC), that is a materially sealed microcosm. composed of primary producers, consumers and bacteria as a decomposer were developed in order to cultivate bacteria without any artificial operation for long duration more than 10 years in space. It is planned to be left on the space station to study the process that bacteria in MIR space station had acquired their resistance to cosmic ray radiation as well as ultra-violet light. As contrasted with the space experiment, bacteria are cultivating in the ECC on the ground to trace the changes of bacteria under the simulated radiation dose in Earth orbit.

Conversion of Amadori product of Maillard reaction to Nepsilon-(carboxymethyl)lysine in alkaline condition

Nepsilon-(carboxymethyl)lysine (CML) is known to be formed by oxidative cleavage of Amadori products between C-2 and C-3 of the carbohydrate chain. We report here that CML formation from Amadori compounds is highly accelerated under alkaline conditions. Incubation of glycated human serum albumin (HSA) in 0.1 N NaOH led to the formation of CML whereas glycated HSA reduced by NaCNBH3 or non-glycated HSA did not generate CML. Nalpha-t-butyloxycarbonyl-Nepsilon-fructoselysine (Boc-FL), a model compound of Amadori product, was converted to CML under alkaline conditions. CML level of human sera (n=224) preincubated with 0.1 N NaOH correlated well with glycated albumin value (r=0.912) and hemoglobin A1c (r=0.797).

Toxicity study of a rubber antioxidant, 2-mercaptobenzimidazole, by repeated oral administration to rats

The chemical structure of 2-mercaptobenzimidazole (2-MBI), which is widely used as a rubber antioxidant, is partially similar to those of thiourea (TU) and ethylenethiourea (ETU), both potent thyrotoxic compounds. In order to determine the oral toxicity of 2-MBI, a 28-day repeated dose toxicity study in Wistar rats followed by observation over a 14-day recovery period was conducted at dose levels of 2, 10 and 50 mg/kg 2-MBI administered by gavage. No toxic deaths occurred due to 2-MBI treatment. Decreases of body weight gain and food consumption in the 50 mg/kg dose group were observed during the second half of the treatment period. In addition, hematological examination and serum biochemical tests revealed decreased white blood cells and hemoglobin and increased serum urea nitrogen, cholesterol, phospholipid, gamma-glutamyl transpeptidase and the Na+/K+ ratio in the 50 mg/kg dose group. Marked thyroid enlargement (to 10 fold the control weight), histopathologically associated with diffuse hyperplasia of follicles with decreased colloid and thickening of the fibrous capsule, was found. Reduction in thymus weight was also observed in a dose-dependent manner, without significant histopathological alteration. The non-observed effect level (NOEL) of 2-MBI in this gavage study was found to be less than 2 mg/kg/day based on the significant decrease in thymus weight in the 2 mg/kg 2-MBI treatment group. In an ancillary study, measurement of serum levels of T3, T4 and TSH, and thyroid weight after gavage treatment with 0.15 and 0.3 mmol/kg of three antithyroid compounds for 14 days revealed a more potent antithyroid effect for 2-MBI than for TU or ETU.

Determination of glycated albumin by enzyme-linked boronate immunoassay (ELBIA)

A new affinity method for quantification of glycated albumin by an enzyme-linked boronate-immunoassay (ELBIA) has been established, based on the interaction between boronic acids and the cis-diols of glycated human serum albumin (HSA) trapped by anti-HSA antibody. To evaluate the ELBIA, we first examined the accuracy of the conventional boronate affinity chromatographic (BAC) method. In the BAC method, 8.1-18.9% of nonglycated albumin calibrator nonspecifically bound to the boronate affinity column, values that were regarded as the column blank. In the modified BAC method, therefore, we substracted the column blank value from the measured glycated albumin value to obtain the true value. Because glycated albumin values measured by ELBIA were exactly the same as reported by the modified BAC method, we suggest that the ELBIA results reflect the real status of albumin glycation. We have also developed a fully automated ELBIA system, allowing multiple, rapid, and precise measurements of glycated albumin.

Mcm2 is a target of regulation by Cdc7-Dbf4 during the initiation of DNA synthesis

The initiation of DNA synthesis is an important cell cycle event that defines the beginning of S phase. This critical event involves the participation of proteins whose functions are regulated by cyclin dependent protein kinases (Cdks). The Mcm2-7 proteins are a family of six conserved proteins that are essential for the initiation of DNA synthesis in all eukaryotes. In Saccharomyces cerevisiae, members of the Mcm2-7 family undergo cell cycle-specific phosphorylation. Phosphorylation of Mcm proteins at the beginning of S phase coincides with the removal of these proteins from chromatin and the onset of DNA synthesis. In this study, we identified DBF4, which encodes the regulatory subunit of a Cdk-like protein kinase Cdc7-Dbf4, in a screen for second site suppressors of mcm2-1. The dbf4 suppressor mutation restores competence to initiate DNA synthesis to the mcm2-1 mutant. Cdc7-Dbf4 interacts physically with Mcm2 and phosphorylates Mcm2 and three other members of the Mcm2-7 family in vitro. Blocking the kinase activity of Cdc7-Dbf4 at the G1-to-S phase transition also blocks the phosphorylation of Mcm2 at this defined point of the cell cycle. Taken together, our data suggest that phosphorylation of Mcm2 and probably other members of the Mcm2-7 proteins by Cdc7-Dbf4 at the G1-to-S phase transition is a critical step in the initiation of DNA synthesis at replication origins.

Evolution of phosphagen kinase. VI. Isolation, characterization and cDNA-derived amino acid sequence of lombricine kinase from the earthworm Eisenia foetida, and identification of a possible candidate for the guanidine substrate recognition site

Lombricine kinase (LK) from the body wall muscle of the earthworm Eisenia foetida was purified to homogeneity. The enzyme was shown to be a dimer consisting of 40 kDa subunits. The cDNA-derived amino acid sequence of 370 residues of Eisenia LK was determined. The validity of the sequence was supported by chemical sequencing of internal tryptic peptides. This is the first reported lombricine kinase amino acid sequence. Alignment of Eisenia LK with those of creatine kinases (CKs), arginine kinases (AKs) and glycocyamine kinase (GK) suggested a region displaying remarkable amino acid deletions (referred to GS region), as a possible candidate for guanidine substrate recognition site. A phylogenetic analysis using amino acid sequences of all four phosphagen kinases indicates that CK, GK and LK probably evolved from a common immediate ancestor protein.

Primary structure of the common polypeptide chain b from the multi-hemoglobin system of the hydrothermal vent tube worm Riftia pachyptila: an insight on the sulfide binding-site

The deep-sea tube worm Riftia pachyptila Jones possesses a multi-hemoglobin system with three different extracellular Hbs: two dissolved in the vascular blood, V1 (ca. 3,500 kDa) and V2 (ca. 400 kDa), and one in the coelomic fluid, C1 (ca. 400 kDa). V1 Hb consists of four heme-containing, globin chains (b-e) and four linker chains (L1-L4). V2 and C1 Hbs are exclusively built from globin chains, six for V2 (a-f) and five for C1 (a-e). The complete amino acid sequence of the isolated monomeric globin chain b, common to all Riftia Hbs, has been determined by automated Edman degradation sequencing of the peptides derived by digestion with trypsin, chymotrypsin, thermolysin, and CNBr. This polypeptide chain is composed of 144 amino acid residues, providing a M(r) of 16, 135.0 Da. Moreover, the primary sequence of chain b revealed 3 Cys residues at position 4, 75, and 134. Cys-4 and Cys-134 are located at positions where an intra-chain disulfide bridge is formed in all annelid, vestimentiferan, or pogonophoran chains, but Cys-75 is located at a unique position only found in three globin chains belonging to Lamellibrachia and Oligobrachia, a vestimentiferan and a pogonophoran. In both groups, Hbs can bind sulfide reversibly to fuel the chemosynthetic process of the symbiotic bacteria they harbor. Sulfide-binding experiments performed on purified Hb fractions (i.e., V1, V2, and C1 Hbs) suggest that free Cys residues on globin chains, and the numerous Cys found in linker chains, as determined previously by ESI-MS, may be the sulfide binding-sites. Blocking the free Cys by N-ethylmaleimide, we confirmed that free cysteines were involved in sulfide-binding but did not account for the whole sulfide-binding capacity of V1 Hb. Furthermore, a phylogenetic tree was constructed from 18 globin-like chains of annelid, vestimentiferan, and pogonophoran extracellular Hbs to clarify the systematic position of tubeworms. Riftia chain b clearly belongs to the "strain A" family with 30 to 80% identity with the other sequences analyzed. Its position in the tree confirmed a close relationship between vestimentiferan, pogonophoran, and annelid Hbs.

Evolution of phosphagen kinase. Isolation, characterization and cDNA-derived amino acid sequence of two-domain arginine kinase from the sea anemone Anthopleura japonicus

Arginine kinase (AK) was isolated from the body wall muscle of the primitive sea anemone Anthopleura japonicus by Ultrogel AcA34 gel filtration, DEAE-32 chromatography and elution on a Cosmogel-SP column. The denatured molecular mass as determined with SDS/PAGE was 80 kDa, twice that of the usual AK subunit, indicating that this AK has an unusual two-domain structure. The native form was eluted on a Superose 12 column with the same retention time as that of rabbit homodimeric creatine kinase, indicating that Anthopleura AK is a monomer of 80 kDa. The isolated enzyme gave a specific activity of 100-120 micromol of Pi/min per mg of protein in the pH range 7.9-9.1 for the forward reaction. The enzyme is fully activated by Ca2+, as it is with Mg2+. The cDNA-derived amino acid sequence of 715 residues of Anthopleura AK was determined. The validity of the sequence was supported by chemical sequencing of internal tryptic peptides. A bridge intron of 686 bp, which separates the two domains of Anthopleura AK, is present between the second and third nucleotide in the codon of Ala-364. This is the first two-domain AK to be sequenced. Anthopleura AK shows 48-54% amino acid sequence identity with known invertebrate AKs, and also shows a lower, but significant, similarity (39-46%) to marine worm glycocyamine kinase and rabbit creatine kinase.

Mutation thi81 causing a deficiency in the signal transduction of thiamine pyrophosphate in Saccharomyces cerevisiae

We isolated a strain carrying a recessive constitutive mutation (thi81) for the expression of thiamine metabolism in Saccharomyces cerevisiae. The thi81 mutant exhibits significant thiamine transport, thiamine-repressible acid phosphatase (T-rAPase) activities and significant activities of enzymes involved in thiamine biosynthesis which are repressed in the wild-type strain in medium supplemented with thiamine (2 x 10(-7) M). The thi81 mutant exhibited the same level of thiamine pyrophosphokinase activity and intracellular thiamine pyrophosphate concentration as the wild-type strain in medium supplemented with exogenous thiamine. The mutant strain constitutively produced PHO3 mRNA encoding T-rAPase in medium supplemented with thiamine. These results suggest that the thi81 mutant lacks a negative factor involved in the regulation of the genes encoding proteins involved in yeast thiamine metabolism.

The effect of nitric oxide synthase inhibitor on form-deprivation myopia

PURPOSE

Form-deprivation myopia (FDM) is believed to result principally from actions of substances that modulate information processing in the retina. We used a chick model to investigate what role nitric oxide (NO), a gaseous neuromodulator, might play in the development of FDM.

METHODS

We injected different concentrations of the NO synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) (30 ml) into the left eyes and the same volume of saline into the right eyes of 6-day-old chicks. Both eyes of most chicks were occluded for 6 days with translucent goggles. After removal of the goggles, the refraction was measured by retinoscopy and the axial lengths with an A-mode ultrasound. In some chicks we measured the concentration of NOx (nitrite and nitrate) in the retina. A few chicks, not wearing occluders after injection of L-NAME and saline, ERG and refraction, were examined 6 days after the treatment.

RESULTS

In chicks that wore occluders, refractive error and axial length were significantly less affected in eyes injected with L-NAME (180, 360, or 540 mM) compared to control (right) eyes. ERG changes were reversible, except in eyes injected with the highest concentration (540 mM) of L-NAME. The eyes of chicks, injected with L-NAME and reared without occlusion, had normal refractive values. After 6 days of form deprivation, the concentration of NOx in the retina of eyes injected with L-NAME (180 mM) was significantly less than the concentration in eyes injected with saline.

CONCLUSIONS

The injection of L-NAME before occlusion of developing chick eyes leads to reversible modifications in retinal function and inhibits the development of form-deprivation myopia.