Species numbers,area, and habitat diversity on the habitat-islands of Mizorogaike pond,Japan

Species-area relationships of flowering plants were analyzed on the habitat-islands (hummocks on a floating bog) of Mizorogaike Pond, Japan. Three habitat units (Sphagnum cuspidatum unit,Sphagnum palustre unit, and fallen leaves unit) in which habitat conditions were homogeneous and a group of habitat-specific species occurred were recognized on the hummocks. Six hummock types were determined according to various combinations of the three habitat units. The most fundamental species-area relationships in which size itself affects the number of species were shown by hummocks with only one habitat unit. The species-area relationships for hummocks with two or three habitat units included the effects of habitat diversity in addition to size. The speciesarea curve for all hummocks was an average of these relationships. It is concluded that area in species-area relationships affects species numbers in two ways: number of habitat units and size of each habitat unit.     

Changes in the hypothalamic-pituitary-thyroid axis during acute starvation in non-obese patients

We investigated changes in the hypothalamic-pituitary-thyroid axis before, during, and after fasting in twenty-one non-obese euthyroid patients with psychosomatic diseases. Blood samples for free T3 (FT3), T3, free T4 (FT4), T4, reverse T3 (rT3), and TSH were obtained from all patients before and on the 5th day of fasting, and in 11 of the same individuals on the 5th day of refeeding. Serum TSH and T3 responses to TRH were also evaluated in 10 patients before and on the 5th day of fasting. During the fast, FT3, T3 and TSH levels decreased significantly and rT3 levels increased significantly whereas FT4 and T4 levels remained within the normal range. Maximal delta TSH, peak TSH levels, max delta T3, peak T3 levels, and net secretory responses to TRH decreased significantly. Peak TSH levels and max delta TSH to TRH correlated well with basal levels of TSH. A statistically significant negative correlation between basal levels of FT4 and TSH was observed. After refeeding, there was a significant increase only in TSH which returned to prefasting values. These results demonstrated that in a state of "low T3" during acute starvation a reduction in serum T3 might depend partly on TSH-mediated thyroidal secretion.     

Enzymatic synthesis of γ-glutamyl-l-histidine by γ-glutamyltranspeptidase from Escherichia coli K-12

γ-Glutamyl- l -histidine was synthesized from l -glutamine and l -histidine by γ-glutamyltranspeptidase (EC 2.3.2.2) from Escherichia coli K-12. The optimum conditions for the production of γ-glutamyl- l -histidine are determined. The yield of γ-glutamyl- l -histidine synthesized under the optimum conditions was 48% with both substrates (41.2 g/l). The product was isolated and then identified by an amino acid analyser, PMR spectrum and secondary ion mass spectrum analyses.     

Transient expression in electroporated pea protoplasts: Elicitor responsiveness of a phenylalanine ammonia-lyase promoter

Summary High yields of viable pea protoplasts were produced from suspension cultured cells and the conditions for the optimum transient expression of the chloramphenicol acetyltransferase (CAT) gene fused to the CaMV 35S promoter after electroporation were investigated. Conditions for elicitor induction of a member of the phenylalanine ammonia-lyase (PAL) gene family in pea was also investigated using a chimeric gene carrying 480 bp of the putative promoter region of gPAL1 connected to bacterial cat gene and nos terminator. CAT activity was considerably induced by the treatment with fungal elicitor (>100 g/ml glucose equivalent) isolated from Mycosphaerella pinodes, a pea pathogen.Abbreviations CAT chloramphenicol acetyltransferase - PAL phenylalanine ammonia-lyase - CM acetylated chloramphenicol - GSH reduced glutathione - NOS nopaline synthase - ES electroporation solution - CaMV cauliflower mosaic virus - GUS -glucuronidase - CHS chalcone synthase - 2,4-D 2, 4-dichlorophenoxyacetic acid Present address: Research Institute, Takasago Perfumery Inc, 5-31-36, Kamata, Minato, Tokyo, 144, Japan Toso Inc, 4560 Oaza-Tomita, Shin-nanyo, Yamaguchi, 746, Japan Central Laboratory of Green Complex, Kasetsert University, Kamphaensaen, Nakohn Pathom, Thailand     

Site-directed mutagenesis of catalytic active-site residues of Taka-amylase A.

The cDNA encoding Taka-amylase A (EC.3.2.1.1, TAA) was isolated to identify functional amino acid residues of TAA by protein engineering. The putative catalytic active-site residues and the substrate binding residue of TAA were altered by site-directed mutagenesis: aspartic acid-206, glutamic acid-230, aspartic acid-297, and lysine-209 were replaced with asparagine or glutamic acid, glutamine or aspartic acid, asparagine or glutamic acid, and phenylalanine or arginine, respectively. Saccharomyces cerevisiae strain YPH 250 was transformed with the expression plasmids containing the altered cDNA of the TAA gene. All the transformants with an expression vector containing the altered cDNA produced mutant TAAs that cross-reacted with the TAA antibody. The mutant TAA with alteration of Asp206, Glu230, or Asp297 in the putative catalytic site had no alpha-amylase activity, while that with alteration of Lys209 in the putative binding site to Arg or Phe had reduced activity.     

Immunomodulation by orally administered protein-bound polysaccharide PSK in patients with gastrointestinal cancer

The present study was designed to assess the effects of the protein-bound polysaccharide PSK on the immunological status of patients with gastrointestinal cancer. Twenty-nine gastric and 18 colorectal cancer patients were randomly assigned to either the control or PSK group. Patients in the PSK group were given 3.0 g of PSK orally before surgery, either daily or every other day. Patients in the control group received no PSK. The data of peripheral blood lymphocytes (PBL) were compared before and after administration of PSK, and those of the regional node lymphocytes (RNL) were compared between the control and the PSK group. The results indicate that the effects of PSK were significantly influenced by the duration of administration, but not by the frequency of administration. In the patients belonging to the short term PSK group (administration <14 days), the response of the PBL to PSK and Con A become significantly stronger compared to before the administration of PSK, whereas the cytotoxicity against K562 and KATO-3, and the proportion of CD16+ cells increased significantly in those patients belonging to the long term PSK group (14 days). In addition, the proportion of CD9 + 11b + suppressor T cells decreased in the RNL of the short term PSK group, whereas the proportion of CD4 + Leu8 - helper T cells in the RNL increased in the long term PSK group.These results suggest that the oral administration of PSK leads to the suppression of suppressor cells in the RNL. Thus, increased numbers of cytotoxic effector cells appear to be activated in the PBL while helper T cells predominate in the RNL.     

Cytokines produced by blood mononuclear cells stimulated with the streptococcal preparation OK-432: effect on production by supplementing the medium with xenogeneic serum

Summary Human blood MNC were stimulated for 7 days with a streptococcal preparation, OK-432, in a medium supplemented with either 10% autologous serum (autoserum) or 10% FCS. Cytokines, including IL-2, IL-1, IFN, and TNF in the supernatants, and antitumor cytotoxicity of MNC were analyzed. None of the IL-2 was detectable during the culture in medium with autoserum, although significant enhancement of cytotoxicity was observed at day 1. On the other hand, production of IL-2 and higher cytotoxicity were induced in the medium with FCS. Even a control culture of MNC unstimulated with OK-432 in the medium with FCS, showed a slight but significant amount of IL-2 and considerable cytotoxicity. However, such a culture in the medium with autoserum showed no such IL-2 production or cytotoxicity. The cytotoxicity induced in the medium with FCS was significantly inhibited by the addition of anti-IL-2 antibody to the culture as well as by the addition of anti-IFN antibody, whereas the cytotoxicity in the medium with autoserum was not inhibited at all by anti-IL-2 antibody. Therefore, the cytotoxicity induced in the medium with FCS included IL-2-induced killer activity, i.e., LAK activity. Similarly, the levels of IL-1, IFN, and TNF production in the supernatants were variable depending on the serum used to supplement the medium. The nonspecific production of IL-2 and the unexpected induction of cytotoxicity were consistently provoked in the medium using several different lots of FCS, but not in the medium with human allogeneic sera or pooled AB serum nor in that with autoserum. It was revealed that the source of sera used to supplement the medium is an important factor affecting the results of analysis of cytokine production and cytotoxicity of MNC induced by certain stimulants. Abbreviations used: NK, natural killer; IFN, interferon; TNF, tumor necrosis factor; IL-1, interleukin-1; IL-2, interleukin-2; LAK, lymphokine-activated killer; MNC, mononuclear cells; FCS, fetal calf serum; ³H-TdR, ³H-Thymidine     

Pfaffosides and nortriterpenoid saponins from Pfaffia paniculata

Three new nortriterpene glucuronides named pfaffosides A, B and C have been isolated from roots of Pfaffia paniculata. Their structures have been established as 3β-O-[β-d-xylopyranosyl-(1→2)β-d-glucuronopyranosyl]-pfaffic acid, 3β-O-[β-d-xylopyranosyl-(1→2)-β-d-glucuronopyranosyl]-pfaffic acid-(28→1)-β-d-glucopyranosyl ester and 3β-O-[β-d-glucuronopyranosyl]-pfaffic acid-(28→ l)-β-d-glucopyranosyl ester, respectively, based on their chemical and spectroscopic properties.     

Leakage of glutathione from bacterial cells caused by inhibition of gamma-glutamyltranspeptidase.

Glutathione leaked from cells of Proteus mirabilis grown in medium containing an inhibitor of gamma-glutamyltranspeptidase. In medium containing 100 mM L-serine and borate, up to 300 microM glutathione accumulated. L-Serine in the medium was consumed during the logarithmic phase of growth, gamma-glutamyltranspeptidase activity was restored, and glutathione decreased in the medium. In the presence of 2 mM 6-diazo-5-oxo-L-norleucine, cells increased normally, gamma-glutamyltranspeptidase was inhibited completely, and the maximum concentration of glutathione which accumulated in the medium was 20 microM. The glutathione content of cells rose before leakage began. Glutathione leaked from intact cells of other bacteria, although to a lesser extent than was seen with P. mirabilis.