Variations in concentrations of bacterial metabolites, enzyme activities, moisture, pH and bacterial composition between and within individuals in faeces of seven healthy adults

Variations between and within individuals, and correlations between concentrations of bacterial metabolites, including putrefactive products, ammonia and short chain fatty acids (SCFAs), enzyme activities, moisture and pH, as well as bacterial composition, were studied in faecal samples from seven healthy adults over a period of 7 months. Large variations, both between and within individuals, were observed in concentrations of putrefactive products. Although values for ammonia, SCFAs, enzyme activities, moisture and pH were generally variable, significant person-to-person differences were observed.
While ranges of log viable counts of the predominant bacteria such as eubacteria, bifidobacteria and bacteroides in each subject remained between 0·2 and 1·3, those of enterobacteria, streptococci (including enterococci) and lecithinase-negative clostridia varied between 0·4 and 3·0. Levels of bifidobacteria, enterobacteria, streptococci and total aerobic bacteria showed inter-individual variations. Correlations were found among certain of the parameters: moisture correlated negatively with p -cresol ( r = -0·707), pH ( r = -0–671) and β-glucosidase activity (GS) ( r = -0·608), and positively with acetic acid ( r = 0·621), while negative correlations were observed in pH with acetic and butyric acids ( r = -0·690 and -0·623, respectively).
No significant correlations were found between bacterial compositions, and other faecal factors such as pH, moisture, metabolic enzyme activities and concentrations of putrefactive products.     

Molecular analysis of the dhp1 + gene of Schizosaccharomyces pombe: an essential gene that has homology to the DST 2 and RAT 1 genes of Saccharomyces cerevisiae

We report here the first cloning of a chalcone flavonone isomerase gene (CHI) from maize. Northern blot experiments indicate that the maize CHI gene (ZmCHI1) is regulated in the pericarp by the P gene, a myb homologue. The ZmCHI1 gene encodes a 24.3 kDa product 55% and 58% identical to CHI-A and CHI-B from Petunia, respectively. This maize CHI gene has four exons and an intron-exon structure identical to the CHI-B gene of Petunia hybrida. RFLP mapping data indicate that some inbred lines contain two additional CHI-homologous sequences, suggesting an organization more complex than that found in Petunia or bean. The possibility that the additional CHI-homologous sequences are responsible for the lack of CHI mutants in maize will be discussed.     

Methenamine-Silver Staining: a Simple and Sensitive Staining Method for Senile Plaques and Neurofibrillary Tangles

An improved methenamine-silver impregnation method is presented which exhibits sensitivity for amyloid substances comparable to that of anti-β protein immunostaining. In optimally treated sections, this technique stained both β-amyloid deposits and neurofibrillary tangles, which are known to have a β-pleated structure. This simple procedure allows a large number of sections to be stained for routine examination.     

Influence of Potassium Concentration in Microdialysis Perfusate on Basal and Stimulated Striatal Dopamine Release: Effect of Ceruletide, a Cholecystokinin-Related Peptide

Abstract: The in vivo microdialysis method was used to study the effect of the cholecystokinin-related peptide, ceruletide, on extracellular levels of dopamine (DA) in the striatum following perfusion with various K⁺ concentrations. Increasing the K⁺ concentration in the perfusate from 4 to 15 or 17.5 m M did not change basal DA release or release evoked by electrical stimulation of the medial forebrain bundle (MFB). However, when the perfusing solution contained 20 or 30 m M K⁺, dose-dependent reductions of both basal and MFB-stimulated DA release occurred. Subcutaneous administration of ceruletide at 160 μg/kg had no influence on the basal or MFB-stimulated DA release with 4 or 15 m M K⁺ in the perfusate. However, after perfusion with 17.5 m M K⁺, ceruletide significantly attenuated the basal and MFB-stimulated DA release. Carbachol (10 μ M ) locally applied via the dialysis probe also attenuated MFB-stimulated DA release after perfusion with 17.5 m M K⁺. From these results, we conclude that under appropriate depolarization of striatal DA terminals, ceruletide induces further depolarization and inactivation of nigrostriatal DA terminals. The present data suggest that this effect may be mediated via intrinsic cholinergic neurons in the striatum.     

Gene introduction into mouse blastocysts via “pricking”

It is a well-known phenomenon that cultured mammalian cells that have been pricked in the presence of foreign DNA can be transformed. This micromanipulation ‘pricking’ technique was applied to mouse blastocysts to determine whether uptake of exogenous DNA would occur in the embryos. The middle region of the inner cell mass (ICM) was pricked three times in each blastocyst in a medium containing a linearized plasmid DNA. When the 60 treated blastocysts were transferred to the uterine horns of pseudopregnant females, 30 developing fetuses (50%) at the mid-gestation stage were obtained. Twenty-two of the 30 fetuses (73%) had less than 1 copy of the foreign DNA per diploid cell, as revealed by polymerase chain reaction (PCR)-Southern analysis, a sensitive technique combined with Southern blot processing of the PCR products. The 8 other fetuses were negative for the foreign DNA. When blastocysts were pricked in the presence of vector DNA coupling E. coli β-galactosidase (β-gal) gene to a mouse metallothionein-I (MT-I) promoter and assessed for β-gal activity histochemically after 1 and 5 days of culture in the presence of 1 μM CdCI₂, at least 65% of the embryos exhibited β-gal activity mainly in the ICM region. These results indicate that mouse blastocysts can be transfected with a relatively high efficiency after pricking, and that the introduced gene expression occurs. This approach provides a means of mapping the regulatory elements of genes that are active in the mouse blastocyst ICM, and may be useful in investigating the fate of the ICM cells in an intact blastocyst by labeling them via pricking technique. © 1993 Wiley-Liss, Inc.     

A protein fraction from aged garlic extract enhances cytotoxicity and proliferation of human lymphocytes mediated by interleukin-2 and concanavalin A

Fraction 4 (F4), a protein fraction isolated from aged garlic extract, enhanced cytotoxicity of human peripheral blood lymphocytes (PBL) against both naturalkiller (NK)-sensitive K562 and NK-resistant M14 cell lines. Although F4 treatment alone increased cytotoxicity, the effect was more remarkable when F4 was administered together with suboptimal doses of interleukin-2 (IL-2); combination treatment of 5 g/ml F4 plus 10 U/ml IL-2 for 72 h generated lymphokine-activated killer activity equivalent to that produced by 100 U/ml IL-2 alone against M14. F4 enhanced IL-2-induced proliferation and IL-2 receptor (Tac) expression of PBL without significant increase of IL-2 production. The enhancement of cytotoxicity both by F4 alone and by F4 plus IL-2 was abolished by anti-IL-2 antibody. F4 also enhanced concanavalin-A(ConA)-induced proliferation of PBL. Radiolabeled-ConA binding assays revealed that F4 treatment greatly augmented the affinity and slightly increased the number of ConA binding sites in PBL. F4 also enhanced ConA-induced IL-2 receptor (Tac) expression and IL-2 production of PBL. Anti-IL-2 antibody inhibited the effect of F4 on ConA-induced proliferation. These data suggest that IL-2 is involved in augmentative effects of F4. Our results indicate that F4 is a very efficient immunopotentiator and may be used for immunotherapy.     

Pattern recognition in DNA sequences and its application to consensus foot-printing

We consider the problem of comparing several nucleic acid sequencesto identify words occurring imperfectly (patterns with no gap)with unusual frequency. Methods for computing, representing,and inspecting interactively the structure of such repeatingmotifs in nucleic acids and more generally any text are described.Multiple sequences are treated as one large concatenate. Ina preprocessing step, a lexical index is created to providerapid string matching for the enumeration of the words matchinga pattern. For given word features (word length, minimal frequency),a sequence profile is displayed. The profile can be inspectedinteractively with on-line algorithms. Applications to the identificationof regulatory elements in DNA regions involved in the controlof gene expression are presented. Our program (‘DNA-Lexemics’)runs on the Macintosh.     

Comparison of dispersal ability between the green leafhoppers,Nephotettix virescens andN. cincticeps (hemiptera: Cicadellidae) by tethered flight

Dispersal propensity of green leafhoppers was compared between a tropical species, Nephotettix virescens, and a temperate species, N. cincticeps. The flight ability was measured with tethered flight technique under laboratory conditions (25°C, 16L-8D). The pre-flight period was shorter and the flight duration was longer in N. virescens than in N. cincticeps in both sexes. No significant correlations were found between the flight activity and morphometric characters for either of the two species. The results suggested that dispersal propensity of N. virescens is higher than that of N. cincticeps.