Complete genome sequence of the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 and comparison with Pyrococcus genomes

The genus Thermococcus, comprised of sulfur-reducing hyperthermophilic archaea, belongs to the order Thermococcales in Euryarchaeota along with the closely related genus Pyrococcus. The members of Thermococcus are ubiquitously present in natural high-temperature environments, and are therefore considered to play a major role in the ecology and metabolic activity of microbial consortia within hot-water ecosystems. To obtain insight into this important genus, we have determined and annotated the complete 2,088,737-base genome of Thermococcus kodakaraensis strain KOD1, followed by a comparison with the three complete genomes of Pyrococcus spp. A total of 2306 coding DNA sequences (CDSs) have been identified, among which half (1165 CDSs) are annotatable, whereas the functions of 41% (936 CDSs) cannot be predicted from the primary structures. The genome contains seven genes for probable transposases and four virus-related regions. Several proteins within these genetic elements show high similarities to those in Pyrococcus spp., implying the natural occurrence of horizontal gene transfer of such mobile elements among the order Thermococcales. Comparative genomics clarified that 1204 proteins, including those for information processing and basic metabolisms, are shared among T. kodakaraensis and the three Pyrococcus spp. On the other hand, among the set of 689 proteins unique to T. kodakaraensis, there are several intriguing proteins that might be responsible for the specific trait of the genus Thermococcus, such as proteins involved in additional pyruvate oxidation, nucleotide metabolisms, unique or additional metal ion transporters, improved stress response system, and a distinct restriction system.     

Immunohistological analysis in the distribution of cells in the fetal porcine adenohypophysis

Adenohypophyses of porcine fetuses from 25 to 110 days of gestation were studied by immunohistochemical staining to ascertain the ontogeny of specific cell types and their spatial distribution in the pars distalis. No hormonecontaining cells were found before 30 days of gestation. ACTH cells were observed first at 40 days, while GH and LH cells appeared first at 60 days. PRL cells were initially detected at 105 days. ACTH immunoreactive cells were also observed in the pars intermedia at 40 days. Blood capillaries were interposed between cell cords of the pars distalis after 40 days of gestation. ACTH cells were evenly distribution in all areas of the pars distalis except the rostal area (sex zone). GH cells were densely distributed in lateral wings of the pars distalis and immediately anterior to Rathke's lumen. PRL cells resembled GH cells in their distribution pattern, but PRL cells were fewer in number. LH cells were scattered in the sex zone of the pars distalis from 60 to 80 days of gestation. After 90 days, they became scattered throughout the pars distalis but were more numerous in the sex zone than in other areas. The inductive elements of adenohypophysial cells from Rathke's pouch epithelia are discussed. We hypothesize that cell cords of specific areas facing Rathke's lumen may differentiate into specific cell types of the pars distalis during fetal life. © 1992 Wiley-Liss, Inc.     

Nuclear magnetic resonance studies on polymer carbanions, 5. Polystyryl carbanion with lithium as counter cation and its dimer model compounds

Oligostyryllithium was synthesized by the reaction of sec-butyllithium with styrene in diethyl ether at ?40°C. Dimer model anions (counter cations: Li and K) of the growing chain ends were synthesized by metallation of 1-methoxy-1,3-diphenylpropane. The structures of the lithium compounds were corroborated by ¹³C NMR spectroscopy and compared with those of the potassium compounds. As for polystyryllithium and its model compounds, the charge density on the α-carbon increased and that on the phenyl ring of the growing end decreased with increasing molecular weight, while, in polystyrylpotassium and its model compounds, the charge density on the α-carbon increased and the one on the phenyl ring did not change with increasing molecular weight. The temperature change of the ¹H NMR spectrum of oligostyryllithium in diethyl ether indicated rotation around the C-1? C_α bond at lower temperatures than in tetrahydrofuran, but the activation energy was the same in both solvents. T₁ values of the phenyl carbons in model compound 2b were one to two orders of magnitude shorter than those of the protonated compound.     

Beta-catenin mutations are frequent in calcifying odontogenic cysts, but rare in ameloblastomas

We have reported previously that alterations to beta-catenin occur frequently in adamantinomatous craniopharyngioma. Based on its histological resemblance to some odontogenic tumors, we suspected the presence of common genetic alterations among these tumors. To address this issue, 11 cases of calcifying odontogenic cyst (COC) and 20 cases of ameloblastoma were investigated for the presence of beta-catenin mutations and beta-catenin expression. Ten COCs were successfully analyzed by direct sequencing, and nine of them were found to harbor somatic beta-catenin mutations. Immunohistochemically, all of the COCs showed nuclear and cytoplasmic expression of beta-catenin with a heterogeneous pattern. No beta-catenin mutations were found in ameloblastomas, except for one case of the follicular type. All follicular ameloblastomas exhibited moderate nuclear and cytoplasmic accumulation of beta-catenin, in contrast to the predominantly membranous expression seen in the plexiform type. beta-Catenin mutation is considered to be a characteristic genetic feature of COC, and may play a critical role in its histogenesis. Although ameloblastoma closely resembles COC histologically, the two have genetically distinctive features.     

The ancillary proteins of HATs: SLC3 family of amino acid transporters

The heteromeric amino acid transporters (HATs) are composed of a light and a heavy subunit linked by a disulfide bridge. The heavy subunits are the SLC3 members (rBAT and 4F2hc), whereas the light subunits are members of the SLC7 family of amino acid transporters. SLC3 proteins are type II membrane glycoproteins (i.e., one single transmembrane domain and the C-terminus located outside the cell) with a bulky extracellular domain that shows homology with alpha-glucosidases. rBAT heterodimerizes with b(0,+)AT (SLC7A9) constituting the amino acid transport b(0,+), the main system responsible for the apical reabsorption of cystine in kidney. The defect in this system causes cystinuria, the most common primary inherited aminoaciduria. 4F2hc subserves various amino acid transport systems by dimerization with different SLC7 proteins. The main role of SLC3 proteins is to help routing of the holotransporter to the plasma membrane. A working model for the biogenesis of HATs based on recent data on the rBAT/b(0,+)AT heterodimeric complex is presented. 4F2hc is a multifunctional protein, and in addition to its role in amino acid transport, it may be involved in other cellular functions. Studies on two SLC7 members (Asc-2 and AGT1) demonstrate heterodimerization with unknown heavy subunits.     

Comparative studies on antibodies to poly(ADP-ribose) in rabbits and patients with systemic lupus erythematosus.

Immunochemical studies were made on the antibodies induced in rabbits against poly(ADP-ribose) and naturally-occurring antibodies in patients with systemic lupus erythematosus. Antibodies against poly(ADP-ribose) could also be induced in rabbits by oligo(ADP-ribose) associated with rat liver histones and by a complex of poly(ADP-ribose) with methylated bovine serum albumin (MBSA). The two types of antibody were inhibited to the same extent by poly(ADP-ribose). However, the antibody induced by oligo(ADP-ribose) associated with histones was inhibited by oligo(ADP-ribose) with an average chain length if 4 ADP-ribosyl units and by phosphoribosyl adenosine monophosphate (PR-AMP) but not by mono ADP-ribose, whereas that induced by poly(ADP-ribose) was practically not inhibited by these related compounds even in excess amounts. The sera of ten cases of systemic lupus erythematosus showing high antibody activity against poly(ADP-ribose) were also examined immunochemically. It was found that the antibodies of three patients showed a similar inhibitory pattern to that of antibody induced in rabbits by oligo(ADP-ribose) associated with histones, those of three patients showed a similar pattern to that of antibody produced in rabbits by poly(ADP-ribose), and the remainder did not show either pattern. These findings suggest that oligo(ADP-ribose) associated with histones may serve as antigen to elicit naturally-occuring antibodies to poly(ADP-ribose) in patients with systemic lupus erythematosus.     

Development of Taenia saginata asiatica metacestodes in SCID mice and its infectivity in human and alternative definitive hosts

Development of Taenia saginata asiatica metacestodes in SCID mice, and its infectivity in humans, golden hamsters, and Mongolian gerbils as alternative definitive hosts, were investigated. Cysticerci were recovered from SCID mice that were subcutaneously injected with hatched oncospheres of T. s. asiatica. The morphological changes of metacestodes were observed. The recovered cysticerci were fed to gerbils, hamsters and humans, to check for their infectivity. Tapeworms were recovered from gerbils and hamsters fed with 20 to 45 week-old cysticerci, and proglottids excretions were observed in human volunteers fed with 45 week-old cysticerci. However, no tapeworms were recovered from gerbils fed with 10 week-old cysticerci. Our results suggest that T. s. asiatica oncospheres needed more than 20 weeks to develop to maturity in SCID mice to be infective to both their natural and alternative definitive hosts.     

Serum FDP assay with latex photometric immunoassay and its analysis by immunoblotting

Sixty patients' sera with FDP-E value ranged from 200 to 2,500 ng/ml by LPIA system were assayed for FDP-Total (FDP-T) by the same system and FDP-DD by ELISA. Correlations of values between FDP-E, FDP-T and FDP-DD were excellent and ratio of FDP-T/FDP-E (T/E) and FDP-DD/FDP-E (DD/E) from same 60 sera were 32.4 + 7.4 and 1.55 + 0.50, respectively. Ratio of T/E from sera of FDP-E value demonstrating more than 500 ng/ml were classified into three groups, namely, 25.0-35.0, less than 18.0, and more than 50.0. Ten sera in each group were analyzed for FDP fragments of D, DD, Y, DY or X (DY/X) and high molecular weight (HMW) with SDS-PAGE and immunoblot method. It was found that relative concentration and proportion of D and DD.E fragments showed its characteristic pattern in each group.     

Flow cytometric and functional analysis of mononuclear cells infiltrating the liver in experimental autoimmune hepatitis.

Experimental autoimmune hepatitis was produced by immunizing Wistar rats with syngeneic liver proteins. Mononuclear cells infiltrating the liver tissue were identified by immunohistochemical techniques using monoclonal antibodies specific for subpopulations of rat lymphocytes. The strong infiltration of CD8+ cytotoxic T lymphocytes (CTL) were found in the portal areas. Subpopulations of mononuclear cells infiltrating the liver, spleen cells and peripheral blood lymphocytes were identified by flow cytometry. Flow cytometric analysis revealed the presence of CD5- and CD8+ lymphocytes in the liver tissues. Mononuclear cells infiltrating the liver were isolated from Wistar rats having autoimmune hepatitis to determine whether those exhibit cytotoxicity against syngeneic hepatocytes; they exhibited cytotoxicity against isolated syngeneic hepatocytes, but failed to lyse K562 cells, syngeneic concanavalin A-activated splenocytes and allogeneic hepatocytes. Depletion of CD8+ T cells significantly reduced the cytotoxic ability of mononuclear cells infiltrating into the liver against syngeneic hepatocytes. These findings support the idea that liver cell injury in experimental autoimmune hepatitis may at least in part be mediated by CTL.     

Pharmacological modifications of endogenous antioxidant enzymes with special reference to the effects of deprenyl: a possible antioxidant strategy

Limited information is available on the upregulation of endogenous antioxidant enzymes by means of administering various pharmaceuticals and/or chemicals. It has been reported that ursodeoxycholic acid (UDCA), a bile acid originally identified from black bear bile (a Chinese medicine, Yutan) increased glutathione S-transferase (GST) activities in mouse livers, resulting in a decrease in systemic lethal toxicity of orally challenged 1-2-dichloro-4-nitrobenzene (DCNB). Also, ursolic acid found in herbal medicines (e.g. leaves of loquat) was reported to increase catalase (CAT) activities in mouse liver. Interestingly, the chemical structures of these two compounds are surprisingly similar to each other, despite the difference in their original sources. These results suggest that in the future, more and more compounds will be found to have effects on increasing endogenous antioxidant enzyme activities. Deprenyl is a monoamine oxidase B inhibitor but also possesses many other different pharmacological activities. Among these various pharmacological effects of deprenyl, a possible causal relationship between two effects of deprenyl, namely the prolongation of the survival of animals and upregulation of antioxidant enzymes in selective brain regions, has been postulated by the authors. In at least four different animal species (rats, mice, hamsters and dogs), a significant prolongation of survival by chronic administration of the drug has been reported by different groups including that of the authors. This group has reported that repeated administration of the drug for 2-3 weeks can significantly increase activities of both types of superoxide dismutase (SODs) (Cu, Zn-, and Mn-SODs) as well as of CAT selectively in brain dopaminergic regions. Both effects are dose dependent but excessive dosages become less effective and even cause an adverse effect (i.e. a decrease in enzyme activities and shortening of life span). The parallelism of the dose-effect relationship between the two phenomena suggests that modification of SOD and CAT levels is one possible mechanism for deprenyl's ability to prolong the life span of animals.