Lobeline production by hairy root culture of Lobelia inflata L.

Hairy roots were obtained following inoculation of the stems of Lobelia inflata L. with Agrobacterium rhizogenes strain ATCC 15834. These hairy roots contained agropine and mannopine. In addition, lobeline was detected by HPLC and confirmed by mass spectrometry. Various media were tested for the growth of hairy roots as well as for the content of lobeline in hairy roots. The growth rate of hairy roots cultured in Nitsch and Nitsch's medium was approximately one third of those cultured in other media. The lobeline content of hairy roots (18–54 g/g dry weight) cultured in these media was the same order of magnitude compared with that of roots of L. inflata (24 g/g dry weight) cultivated in pots. The hairy roots cultured in Nitsch and Nitsch's medium were morphologically different from those cultured in other media.Abbreviations MS medium Murashige and Skoog's medium - 1/2 MS medium one-half strength of the standard Murashige and Skoog's medium - B5 medium Gamborg's B5 medium - NN medium Nitsch and Nitsch's medium - FW fresh weight - DW dry weight     

Mechanism of Electron Flow through the QB Site in Photosystem II. 4. Reaction Mechanism of Plastoquinone Derivatives at the QB Site in Spinach Photosystem II Membrane Fragments

Interactions of externally added plastoquinone (PQ) derivatives(PQ₀-PQ₃) with the photosystem II (PSII) acceptor side wereinvestigated in PSII membrane fragments prepared from spinachby measuring the photoreduction rates of PQ derivatives at variousPQ concentrations, and the following results were obtained. From the kinetic analysis, all the PQ derivatives (PQ₀-PQ₃)except PQ₃ were shown to accept electrons at two sites (theQ_B site and the PQ site) as in the case of Synechococcus vulcanusPSII particles with benzoquinone derivatives [Satoh et al. (1995)Plant Cell Physiol. 36: 597]. Affinities of PQ derivatives at the Q_B site increased as thelength of the isoprene side chain got longer, while those atthe PQ site were not very much different for all the PQ derivativestested in this study. The inhibitory effect of DCMU was noncompetitive, and, therefore,the affinity of PQ₃ for the PQ site was determined while thatfor the Q_B site could not be estimated presumably due to itsfairly high affinity to the site. Based on the results obtained using PQ derivatives, the mechanismof interaction of an authentic PQ, PQ₉, at the Q_B site is discussed. (Received May 2, 1996; Accepted July 24, 1996)     

Alkaline phosphatase reactivity in rabbit airway epithelium: a potentially useful marker for airway basal cells

The purpose of this study was to investigate alkaline phosphatase (ALPase) reactivity in rabbit airway epithelial cells. Acetone-fixed, methyl benzoate and xylene-cleared (AMeX-treated) paraffin sections of trachea, bronchus, and lung tissue were stained by an azo dye coupling method for ALPase and examined by light microscopy. Electron histochemical staining was also performed in order to study the sensitivity and specificity of reactivity in each cell type. ALPase reactivity at the light microscopic level was observed exclusively in trachco-bronchial basal cells, and not in bronchiolar basal cells. By electron microscopy, ALPase reactivity was noted in 97.9% of basal cells in the trachea, 97.0% of basal cells in the bronchus, and 94.5% of basal cells and 15.4% of Clara cells in the bronchiole. This was also true for dispersed tracheal epithelial cells. Reactivity was rarely observed in ciliated cells, non-goblet-type secretory cells, and undetermined cells. The reactivity was heatlabile, levamisole-sensitive, and of a non-specific type. These findings indicate that basal cells of rabbit trachea and bonchus have fairly high specificity for ALPase of a non-specific isozyme (92.2% and 95.6%, respectively). Therefore, ALPase is considered to be a useful marker for these cells.     

3,5-Di-tert-butyl-4-hydroxybenzylidenemalononitrile. Effects of pH on its binding to liposomes and evidence for formation of a ternary complex with valinomycin and potassium ion

1. The properties of 3,5-di-tert-butyl-4-hydroxybenzylidenemalononitrile (SF 6847) were studied chemically and spectroscopically. Two molecular species of SF6847 were identified: the undissociated form (SFH; ?₃₆₃, 10 mM^?1) and the dissociated form (SF^?; ?₄₅₄, 35 mM^?1). The pK_a value of the molecule was determined to be 6.9.2. On the basis of these properties the interactions of SF6847 with liposomes and valinomycin · K⁺ were studied. The partition constants of SFH (Kⁿ_p and SF^? (K^?_p) to liposomes were determined separately; Kⁿ_p was 56 mM^?1 and was independent of the pH of the medium, whereas K^?_p dependend greatly on the pH, being 1.2 mM^?1 at pH 7.0 and 2.9 mM^?1 at pH 8.0. Using these values, the partition constant of total SF6847 (K_p) was calculated and found to be essentially the same as that calculated from the kinetics of proton uptake. It was concluded that the amount of SF^? bound to liposomes is rate limiting for proton uptake.3. The effects of membrane potential on partition constants were studied. The K^?_p decreased greatly upon generation of a membrane potential negative inside the liposomes but increased upon generation of a membrane potential positive inside the liposomes.4. The interaction of SF6847 with valinomycin in aqueous solution and in liposomes was demonstrated only in the presence of potassium ion. Potassium ion could not be replaced by sodium ion. Evidence was obtained for the formation of the ternary complex valinomycin · K⁺ · SF^? in liposomes and in hexane. It was concluded that SF^? became more soluble in the liposomal membranes on formation of this ternary complex. All these results support our proposed mechanism for the proton uptake cycle (Yamaguchi, A. and Anraku, Y. (1978) Biochim. Biophys. Acta 501, 136–149).     

Plasma brain natriuretic peptide as a surrogate marker for cardioembolic stroke

Background

Cardioembolic stroke generally results in more severe disability, since it typically has a larger ischemic area than the other types of ischemic stroke. However, it is difficult to differentiate cardioembolic stroke from non-cardioembolic stroke (atherothrombotic stroke and lacunar stroke). In this study, we evaluated the levels of plasma brain natriuretic peptide in acute ischemic stroke patients with cardioembolic stroke or non-cardioembolic stroke, and assessed the prediction factors of plasma brain natriuretic peptide and whether we could differentiate between stroke subtypes on the basis of plasma brain natriuretic peptide concentrations in addition to patient's clinical variables.

Methods

Our patient cohort consisted of 131 consecutive patients with acute cerebral infarction who were admitted to Kagawa University School of Medicine Hospital from January 1, 2005 to December 31, 2007. The mean age of patients (43 females, 88 males) was 69.6 ± 10.1 years. Sixty-two patients had cardioembolic stroke; the remaining 69 patients had non-cardioembolic stroke (including atherothrombotic stroke, lacunar stroke, or the other). Clinical variables and the plasma brain natriuretic peptide were evaluated in all patients.

Results

Plasma brain natriuretic peptide was linearly associated with atrial fibrillation, heart failure, chronic renal failure, and left atrial diameter, independently (F_4,126 = 27.6, p < 0.0001; adjusted R² = 0.45). Furthermore, atrial fibrillation, mitral regurgitation, plasma brain natriuretic peptide (> 77 pg/ml), and left atrial diameter (> 36 mm) were statistically significant independent predictors of cardioembolic stroke in the multivariable setting (Χ² = 127.5, p < 0.001).

Conclusion

It was suggested that cardioembolic stroke was strongly predicted with atrial fibrillation and plasma brain natriuretic peptide. Plasma brain natriuretic peptide can be a surrogate marker for cardioembolic stroke.     

A Factor That Interrupts the Cell Cycle at G2 or Prophase is Present in Full-Grown Frog Oocytes

Full-grown amphibian oocytes that had been arrested at meiotic prophase I contained an activity that prevented the cell cycle from progressing beyond a G₂-like stage. Injection of the contents of germinal vesicles (GV-content) or cytoplasm obtained from oocytes of the frog Rana rugosa prevented fertilized eggs of Cynops pyrrhogaster or Bufo japonicus from cleaving. The nuclei in the arrested eggs consisted of thin chromosomes and nucleolus-like particles enclosed within clear nuclear membrane and their volume increased as a function of time after injection. Cycling of maturation-promoting factor (MPF) did not occur in the injected eggs, but DNA synthesis was not disturbed. The injection of exogenous MPF into the eggs induced the reinitiation of the cell cycle with progression to the M phase and subsequent cleavage. Furthermore, the injection into the full-grown oocytes of Bufo inhibited induction of the maturation of oocytes by progesterone. These results demonstrate that a factor that arrests the cell cycle either at a G₂-like stage of mitosis or at prophase in meiosis is present both in the GV and cytoplasm of frog oocytes. We refer to this factor as a G₂-specific cytostatic factor (G₂-CSF). G₂-CSF may play an important role not only in the physiological arrest at prophase I in meiosis, but also in regulation of the G₂/M transition in the cell cycle of early embryonic cells.     

Surgical stress during operation for gastrointestinal cancer increases plasma thioredoxin levels and decreases mitochondrial membrane potential in peripheral blood lymphocytes

Surgical stress is difficult to evaluate quantitatively. It has been reported that mitochondrial membrane potential (delta psi(m)) in the peripheral blood lymphocytes (PBLs) is decreased by surgical stress. Thioredoxin (TRX), a small protein with redox-active dithiol/disulfide in the active site, is induced by a variety of oxidative stresses and secreted from the cells. Accumulating evidence shows that plasma levels of TRX are elevated in oxidative stress-associated disorders. In the present study, we examined plasma levels of TRX in cases undergoing operations for gastrointestinal cancer. Plasma levels of TRX were significantly elevated on the first postoperative day compared with the pre-operative levels. The changes in the plasma TRX levels tended to show an inverse relationship with the changes in delta psi(m) in PBLs, which shows a significant decrease caused by surgical stress. Plasma TRX levels as well as delta psi(m) in PBLs are valuable markers to evaluate surgical stress.     

Chemiosmotic coupling of ion transport in the yeast vacuole: Its role in acidification inside organelles

Acidification inside the vacuo-lysosome systems is ubiquitous in eukaryotic organisms and essential for organelle functions. The acidification of these organelles is accomplished by proton-translocating ATPase belonging to the V-type H⁺-ATPase superfamily. However, in terms of chemiosmotic energy transduction, electrogenic proton pumping alone is not sufficient to establish and maintain those compartments inside acidic. Current studies have shown that thein situ acidification depends upon the activity of V-ATPase and vacuolar anion conductance; the latter is required for shunting a membrane potential (interior positive) generated by the positively charged proton translocation. Yeast vacuoles possess two distinct Cl^– transport systems both participating in the acidification inside the vacuole, a large acidic compartment with digestive and storage functions. These two transport systems have distinct characteristics for their kinetics of Cl^– uptake or sensitivity to a stilbene derivative. One shows linear dependence on a Cl^– concentration and is inhibited by 4,4-diisothiocyano-2,2-stilbenedisulfonic acid (DIDS). The other shows saturable kinetics with an apparentK _m for Cl^– of approximately 20 mM. Molecular mechanisms of the chemiosmotic coupling in the vacuolar ion transport and acidification inside are discussed in detail.     

Long-term Administration of Probiotics to Asymptomatic Pre-school Children for Either the Eradication or the Prevention of Helicobacter pylori Infection

Background:  The role of probiotics in the armamentarium remains to be defined. The aims of this study were to investigate whether the long-time administration of Lactobacillus gasseri OLL2716 (LG21) strain can eradicate H. pylori in asymptomatic pre-school children and/or prevent H. pylori infection.
Methods: A total of 440 children, from 5–7 years of age, attending a kindergarten in Thailand were screened by the Helicobacter pylori stool antigen (HpSA) test. Thereafter 132 H. pylori positive and 308 H. pylori negative children were recruited to eradication and randomized prevention arms, respectively. Children in the active and placebo treatment groups received Lactobacillus gasseri OLL2716 (LG21) containing cheese and ordinary cheese, respectively, for 12 months. Eradication was defined as reversion by HpSA at 12 months. Prevention was defined as persistently HpSA negative at 12 months.
Results:  Eighty-two of 132 H. pylori positive (62%) completed the eradication arm, of which 24 (29.3%) were negative at 12 months according to the HpSA test. In the randomized prevention arm, 123 of 156 (79%) and 99 of 122 (81%) completed active and placebo arms, respectively, of which 4.1% and 8.1%, respectively, were HpSA positive at 12 months based on a per-protocol analysis ( p  = .21).
Conclusion: Further trials are needed.