The Gene Encoding Flavanone 3-Hydroxylase is Expressed Normally in the Pale Yellow Flowers of the Japanese Morning Glory Carrying the speckled Mutation Which Produce Neither Flavonol nor Anthocyanin but Accumulate Chalcone, Aurone and Flavanone

The Japanese morning glory carrying the recessive mutable speckledallele with the dominant speckled-activator bears colorlessflowers with fine and round colored spots distributed over thecorolla whereas the plant without the speckled-activator producespale yellow flowers. Previous chemical analysis has indicatedthat a mutation in the gene for flavanone 3-hydroxylase (F3H)is a likely candidate for the speckled allele. However, theF3HmRNA without sequence alteration accumulates normally inthe pale yellow flowers, indicating that the speckled alleleis neither the F3H gene nor a regulatory gene acting on theF3H gene expression. (Received April 4, 1997; Accepted June 2, 1997)     

Evolution of green lacewings (Neuroptera: Chrysopidae): a molecular supermatrix approach

We present a time‐calibrated phylogeny of the charismatic green lacewings (Neuroptera: Chrysopidae). Previous phylogenetic studies on the family using DNA sequences have suffered from sparse taxon sampling and/or limited amounts of data. Here we combine all available previously published DNA sequence data and add to it new DNA sequences generated for this study. We analysed these data in a supermatrix using Bayesian and maximum likelihood methods and provide a phylogenetic hypothesis for the family that recovers strong support for the monophyly of all subfamilies and resolves relationships among a large proportion of chrysopine genera. Chrysopinae tribes Leucochrysini and Belonopterygini were recovered as monophyletic sister clades, while the species‐rich tribe Chrysopini was rendered paraphyletic by Ankylopterygini. Relationships among the subfamilies were resolved, although with relatively low statistical support, and the topology varied based on the method of analysis. Greatest support was found for Apochrysinae as sister to Nothochrysinae and Chrysopinae, which is in contrast to traditional concepts that place Nothochrysinae as sister to the rest of the family. Divergence estimates suggest that the stem groups to the various subfamilies diverged during the Triassic‐Jurassic, and that stem groups of the chrysopine tribes diverged during the Cretaceous.     

Determinants of Slow Walking Speed in Ambulatory Patients Undergoing Maintenance Hemodialysis

Walking ability is significantly lower in hemodialysis patients compared to healthy people. Decreased walking ability characterized by slow walking speed is associated with adverse clinical events, but determinants of decreased walking speed in hemodialysis patients are unknown. The purpose of this study was to identify factors associated with slow walking speed in ambulatory hemodialysis patients. Subjects were 122 outpatients (64 men, 58 women; mean age, 68 years) undergoing hemodialysis. Clinical characteristics including comorbidities, motor function (strength, flexibility, and balance), and maximum walking speed (MWS) were measured and compared across sex-specific tertiles of MWS. Univariate and multivariate logistic regression analyses were performed to examine whether clinical characteristics and motor function could discriminate between the lowest, middle, and highest tertiles of MWS. Significant and common factors that discriminated the lowest and highest tertiles of MWS from other categories were presence of cardiac disease (lowest: odds ratio [OR] = 3.33, 95% confidence interval [CI] = 1.26–8.83, P<0.05; highest: OR = 2.84, 95% CI = 1.18–6.84, P<0.05), leg strength (OR = 0.62, 95% CI = 0.40–0.95, P<0.05; OR = 0.57, 95% CI = 0.39–0.82, P<0.01), and standing balance (OR = 0.76, 95% CI = 0.63–0.92, P<0.01; OR = 0.81, 95% CI = 0.68–0.97, P<0.05). History of fracture (OR = 3.35, 95% CI = 1.08–10.38; P<0.05) was a significant factor only in the lowest tertile. Cardiac disease, history of fracture, decreased leg strength, and poor standing balance were independently associated with slow walking speed in ambulatory hemodialysis patients. These findings provide useful data for planning effective therapeutic regimens to prevent decreases in walking ability in ambulatory hemodialysis patients.     

The augmentation of tumor-specific immunity using haptenic muramyl dipeptide (MDP) derivatives

Summary A new haptenic compound, a muramyl dipeptide (MDP) derivative (designated as L4-MDP-ONB) cross-reactive with Bacillus Calmette Guerin (BCG) was synthesized. The cross-reactivity of L4-MDP hapten to BCG was demonstrated from the following evidence; (a) lymph node cells from BCG-primed C3H/HeN mice exhibited appreciable L4-MDP-specific proliferative responses to the in vitro stimulation of L4-MDP-modified syngeneic cells (L4-MDP-self); (b) inoculation of L4-MDP-self into footpads of BCG-primed C3H/HeN mice elicited ample delayed type-hypersensitivity (DTH) responses in vivo as measured by footpad swelling; and (c) BCG-primed mice contained L4-MDP-reactive helper T cell activity which functions to augment the generation of effector T cell responses to cell surface antigens. This crossreactivity between L4-MDP hapten and BCG as measured by the helper T cell activity was applied to enhanced induction of tumor-specific immunity. When BCG-primed C3H/HeN mice were immunized with L4-MDP-modified syngeneic X5563 tumor cells, these mice could generate augmented tumor-specific in vivo protective (tumor neutralizing) immunity as well as in vitro cytotoxic T cell responses. These results indicate the effectiveness of L4-MDP hapten in augmenting tumor-specific immunity. The present approach is discussed in the context of potential advantages of this new hapten for its future application to clinical tumor systems.     

Monodeiodination of thyroxine to 3, 5, 3'-triiodothyronine and to 3, 3', 5'-triiodothyronine in isolated dog renal cortical tubuli

Monodeiodination of T4 to T3 and rT3 in the intact cells of dog renal tubuli and glomeruli was investigated. The tubuli and glomeruli were obtained by a sieve method. T4 (2 micrograms/ml) was incubated in Tris-HCl buffer, pH 7.5, with renal cells (180 micrograms protein/ml) and 5 mM DTT for 1 h at 37 degrees C and the T3 and rT3 generated during incubation were measured by specific radioimmunoassays. In order of decreasing activity, dog renal cortical tubuli, cortical homogenate, glomeruli and medullary tubuli were capable of converting T4 to T3. Net rT3 production from T4 in cortical tubuli was also greater than that in cortical homogenate. The conversion of T4 to T3 and also to rT3 in cortical tubuli was enzymatic in nature, since the reactions showed dependence on time and protein concentration; instability to heating; temperature and pH optimum. The production of T3 and rT3 from T4 was maximum at pH 6.5 and at pH 9.5, respectively, indicating that two different enzymic systems, a 5- and a 5'-monodeiodinase, might be involved in the deiodination of the tyrosyl and the phenolic ring of T4 in dog kidney.     

Measurement of Serine Acetyltransferase Activity in Crude Plant Extracts by a Coupled Assay System Using Cysteine Synthase

Serine acetyltransferase (SATase) (EC 2.3.1.30 [EC] ) catalyzes theformation of Oacetyl-L-serine (OAS) from L-serine in the presenceof acetyl-CoA. A novel assay method was developed for measuringthis enzyme activity in extracts from plant tissues. The assayconsists of a coupled system in which the OAS formed is convertedto cysteine by the addition of cysteine synthase (CSase) (EC4.2.99.8 [EC] ). Cysteine thus formed is determined colorimetricallyand serves as a measure for SATase activity. This method israpid, simple and sensitive, and can be readily adapted formeasurement of SATase activity in crude tissue extracts or homogenates. (Received January 14, 1987; Accepted April 27, 1987)     

Characterization and physiological function of glutathione reductase in Euglena gracilis z.

The purified glutathione reductase was homogeneous on polyacrylamide-gel electrophoresis. It had an Mr of 79,000 and consisted of two subunits with a Mr of 40,000. The activity was maximum at pH 8.2 and 52 degrees C. It was specific for NADPH but not for NADH as the electron donor; the reverse reaction was not observed. The Km values for NADPH and GSSG were 14 and 55 microM respectively. The enzyme activity was markedly inhibited by thiol inhibitors and metal ions such as Hg2+, Cu2+ and Zn2+. Euglena cells contained total glutathione at millimolar concentration. GSH constituted more than 80% of total glutathione in Euglena under various growth conditions. Glutathione reductase was located solely in cytosol, as were L-ascorbate peroxidase and dehydroascorbate reductase, which constitute the oxidation-reduction cycle of L-ascorbate [Shigeoka et al. (1980) Biochem. J. 186, 377-380]. These results indicate that glutathione reductase functions to maintain glutathione in the reduced form and to accelerate the oxidation-reduction of L-ascorbate, which scavenges peroxides generated in Euglena cells.     

Isolation, purification, and characterization of the pellicle of Euglena gracilis z

The pellicle was isolated from the cell homogenate obtained on sonication of Euglena gracilis z grown aerobically under illumination and purified by a combination of differential and sucrose density gradient centrifugations. The purity and homogeneity of the pellicle fragments were determined by an electron microscopic method and biochemical analysis of the components. The protein, lipid, and sugar contents of the purified pellicle were 68.7, 17.9, and 13.5%, respectively. The equilibrium density of pellicle fragments was 1.21 g/cm3. SDS-polyacrylamide gel electrophoresis revealed that the pellicle contained 50 mol% of nonpolar amino acids. The constituents of the lipid and sugar were very different from those of the cell membrane of other organisms.