A kinetics study on the production of alkaline proteinase by Bacillus licheniformis 2709

With automatic control fermentation equipment, the kinetics of growth and metabolism of Bacillus licheniformis 2709 was studied with batch culture as well as with fed-batch-culture by controlling the concentration of the growth-limiting substrate. The Monod formula proved to be reasonable in describing the relationship between cell growth rate of B. licheniformis 2709 and the concentration of the growth-limiting substrate in the broth, and the data of product synthesis rate showed that the fermentation type belongs to one partially related to growth.

Differentiation in a rat PC12 cell line induced by ostruthin and (-)-bornyl ferulate, constituents of a Chinese herbal medicine

A search for neuritogenic compounds in Chinese herbs resulted in the isolation of two known substances, ostruthin and (-)-bornyl ferulate, from Notopterygium incisum (and/or N. forbesii). Both compounds induced comparable neurite-like structures in 20% of rat PC12 cells at 2 micrograms/ml, and showed cytotoxicity at concentrations higher than 3 micrograms/ml.

Pharmacokinetic interaction between acetaminophen and lansoprazole

Because of its minimal gastric toxicity, acetaminophen is the analgesic of choice for patients with gastric acid-related disorders. Because proton pump inhibitors are widely used, concomitant prescription of acetaminophen and lansoprazole would be prevalent. This crossover study was conducted to investigate an acetaminophen-lansoprazole interaction. On one occasion, each of six healthy, fasted, male volunteers ingested 1.0 g acetaminophen dissolved in 200 mL water. On another occasion, at least 1 week apart, 30 mg lansoprazole was administered orally, simultaneously with acetaminophen, after pretreatment with the same dose of lansoprazole once daily for 2 days. Plasma acetaminophen concentrations were measured at 0, 0.25, 0.5, 0.75, 1, 2, 3, 5, and 8 hours after dosing. The peak plasma concentration of acetaminophen and the time to its occurrence were significantly higher and shorter, respectively, during the lansoprazole session than during the control session. Neither the elimination half-life nor the area under the curve was significantly different between the two sessions. Lansoprazole hastens the absorption of acetaminophen solution, but little modifies its elimination rate and bioavailability.

Syntaxin 1A inhibits regulated CFTR trafficking in xenopus oocytes

The cystic fibrosis transmembrane conductance regulator (CFTR) is an epithelial cell Cl channel, whose gating activity and membrane trafficking are controlled by cAMP/protein kinase A (PKA)-mediated phosphorylation. CFTR Cl currents are regulated also by syntaxin 1A (A. P. Naren, D. J. Nelson, W. W. Xie, B. Jovov, J. Pevsner, M. K. Bennett, D. J. Benos, M. W. Quick, and K. L. Kirk. Nature 390: 302-305, 1997), a protein best known for its role in membrane trafficking and neurosecretion. To examine the mechanism of syntaxin 1A inhibition, we expressed these proteins in Xenopus oocytes and monitored agonist-induced changes in plasma membrane capacitance and cell surface fluorescence of CFTR that contains an external epitope tag. cAMP stimulation elicited large increases in membrane capacitance and in cell surface labeling of flag-tagged CFTR. Coexpression of CFTR with syntaxin 1A, but not syntaxin 3, inhibited cAMP-induced increases in membrane capacitance and plasma membrane CFTR content. Injection of botulinum toxin/C1 rapidly reversed syntaxin's effects on current and capacitance, indicating that they cannot be explained by an effect on CFTR synthesis. Functional expression of other integral membrane proteins, including Na-coupled glucose transporter hSGLT1, inwardly rectified K channel hIK1, P2Y2 nucleotide receptor, and viral hemagglutinin protein, was not affected by syntaxin 1A coexpression. These findings indicate that acute regulation of the number of CFTR Cl channels in plasma membrane is one mechanism by which cAMP/PKA regulates Cl currents. Inhibition of plasma membrane CFTR content by syntaxin 1A is consistent with the concept that syntaxin and other components of the SNARE machinery are involved in regulated trafficking of CFTR.

Effects of cyanide and hypoxia on membrane currents in neurones acutely dissociated from the rostral ventrolateral medulla of the rat

Previous reports suggested that some neurones located in the rostral ventrolateral medulla (RVL) can act as fast oxygen sensors which enhance the sympathetic activity and blood pressure independent of peripheral chemoreceptors. The aim of this study was to compare hypoxic responses of different subpopulations of RVL neurones to ascertain whether the hypoxic sensitivity is restricted to one group of these neurones. Whole-cell patch-clamp recordings were made from acutely dissociated neurones obtained from RVL of P13-P19 rats. Short-lasting hypoxia (1-2 min) was evoked by pressure injection of NaCN or lowering pO2. Cells projecting to the upper thoracic segments were retrogradely labelled with fluorescent beads. Catecholaminergic (CA) or non-catecholaminergic (non-CA) neurones were identified using single-cell reverse-transcription polymerase chain reaction (RT-PCR) or immunocytochemistry. Recordings were made from 38 neurones (26 spinally-projecting, 12 non-spinal) using Cs+/TEA or K+-containing pipettes. In most of the cells tested with slow depolarising ramp commands (78%; including spinally-projecting and non-spinal neurones, as well as CA and non-CA neurones), NaCN or hypoxia evoked a reversible increase of the sustained inward current. Extracellular application of 1 mM Co2+ or 25 nM TTX revealed three components of the hypoxia-sensitive inward current which resembled the persistent sodium (INaP), low threshold calcium (LVA Ca2+) and high threshold calcium (HVA Ca2+) currents. The NaCN or hypoxia induced increase of the current could also be observed during step commands. Recordings with K+-containing pipettes during similar depolarising ramps revealed, in addition, a reversible increase of IK in 78% of tested cells (in all four types of examined neurones). These results are consistent with the concepts that RVL neurones can act as a central oxygen sensor. However, in contrast to the previously published data demonstrating that in pentobarbital anaesthetised rats only the barosensitive and spinally projecting cells were affected by a short-lasting hypoxia, our findings obtained with dissociated RVL neurones indicate that sensitivity to hypoxia is widely distributed within this part of the medulla oblongata.

[Study of mutagenesis of two procarcinogens in human amnion cells using a shuttle vector pWB1]

Using 2 x 10(-5) mol/ml beta-NF (beta-naphthoflavone) to induce FL cells to express cytochrome P450 isozymes at a reasonable level, we have studied the mutagenesis of two procarcinogens, aflatoxin B1 and benzo (alpha)pyrene, at four different doses. Except for their top doses, all other doses induced mutation in target gene SupF carried by plasmid pWB1 at the frequency of 10(-4), which is higher than the spontaneous mutation frequency (7.61 x 10(-6)). Aflatoxin B1 demonstrated normal effect-dose relationship. Meanwhile no mutant was detected in their correspondent negative controls. All the results suggest that shuttle vector pWB1 can be conveniently used for detection of procarcinogens and study of their mutagenesis mechanisms in human cells.

Human dendritic cells express the thrombopoietin receptor, c-Mpl

Human thrombopoietin (TPO) is a haemopoietic growth factor that is essential for the growth and development of megakaryocytes. However, c-Mpl, the TPO receptor, has been detected in human leukaemic cell lines with a myelomonocytic phenotype. These results raise the possibility that dendritic cells (DC), a putative myeloid lineage cell, may also express c-Mpl and respond to TPO. In haemopoietic stem cell transplantation, DC could induce graft-versus-host disease by its strong antigen-presenting capacity. In this study we have examined the effect of TPO on differentiation and the antigen-presenting capacity of DC. To differentiate DC, cord blood CD34+ cells were cultured in the presence of a cytokine cocktail either in serum-free medium or RPMI1640 containing 10% fetal bovine serum. Flow cytometric analysis and immunocytochemical staining demonstrated that c-Mpl was expressed on DC. Furthermore, the expression of c-Mpl mRNA was detected in DC by RNase protection assay. However, when TPO was added to the culture system there were no significant changes in the differentiation and mixed leucocyte-stimulating capacity of DC. These findings suggest that TPO may be administered following cord blood transplantation without significant augmentation of antigen presentation mediated by DC.

Differential effects of olanzapine on the gene expression of superoxide dismutase and the low affinity nerve growth factor receptor

Neuroanatomical studies of schizophrenia suggest that progressive neuropathological changes (such as neuronal atrophy and/or cell death) occur over the lifetime course of the disease. Early intervention with atypical neuroleptics has been shown to prevent progression of at least some symptoms, although the mechanisms by which neuroleptics may do this remain unknown. In this study, PC12 cells were used to determine the effects of the new atypical antipsychotic olanzapine on the gene expression of superoxide dismutase (SOD1) and the low affinity nerve growth factor receptor (p75). The results show that olanzapine increases SOD1 at concentrations of 10 and 100 microM after 48 hr of incubation in PC12 cultures. The treatment decreases p75 gene expression at concentrations 100 microM after 48 hr of incubation. Since both the upregulation of SOD1 mRNA and the antisense blockade of p75 mRNA have been associated with reduced cell death, our results suggest that olanzapine has neuroprotective potential and thus may be useful in preventing further neurodegeneration accompanying schizophrenia.

A theoretical study of the contrast recovery and variance of MAP reconstructions from PET data

We examine the spatial resolution and variance properties of PET images reconstructed using maximum a posteriori (MAP) or penalized-likelihood methods. Resolution is characterized by the contrast recovery coefficient (CRC) of the local impulse response. Simplified approximate expressions are derived for the local impulse response CRC's and variances for each voxel. Using these results we propose a practical scheme for selecting spatially variant smoothing parameters to optimize lesion detectability through maximization of the local CRC-to-noise ratio in the reconstructed image.

Noradrenaline transporter expression in the pons and medulla oblongata of the rat: localisation to noradrenergic and some C1 adrenergic neurones

Catecholaminergic neurotransmission is normally terminated by rapid re-uptake of the neurotransmitter by a high-affinity Na+/Cl--dependent plasma membrane transporter. Specific transporters have been cloned for both dopamine (DAT) and noradrenaline (NAT) in the rat. While DAT has been studied extensively, NAT expression has received less attention, particularly at the protein level. We used an antibody generated against a 49 residue segment of an extracellular loop region of NAT to study expression of the transporter protein throughout the rat pons and medulla oblongata. NAT was expressed in over 95% of noradrenergic neurones in the A1, A2/area postrema, A5, A6/locus subcoeruleus, and A7 noradrenergic groups. Approximately 10% of C1 adrenergic neurones located in the rostral ventrolateral medulla (RVL) also expressed NAT. Expression of NAT mRNA in bulbospinal C1 cells was confirmed using single-cell reverse transcription polymerase chain reaction (RT-PCR) of acutely isolated RVL neurones. Spinally projecting neurones were identified by retrograde labelling with rhodamine beads, and C1 neurones were identified by RT-PCR using primers specific for tyrosine hydroxylase (TH) or phenylethanolamine N-methyltransferase (PNMT) mRNAs. Thirteen percent of adrenergic bulbospinal neurones tested expressed NAT mRNA. C1 neurones are potentially important in cardiovascular control and blood pressure regulation, and the identification of NAT expression in a sub-population of these neurones provides further evidence for the heterogeneity of this neuronal population.

Late-onset unilateral renal dysfunction combined with non-insulin-dependent diabetes mellitus and bronchial asthma following allogeneic bone marrow transplantation for acute lymphoblastic leukemia in a child

We report a child with T cell acute lymphoblastic leukemia who developed late-onset multiple complications after allogeneic bone marrow transplantation from an HLA-matched sibling. The preparative regimen consisted of total body irradiation (TBI, 12 Gy), splenic irradiation (6 Gy) and cytosine arabinoside (3 g/m2 x 10). Splenic irradiation was added because of persistent splenomegaly in spite of intensive chemotherapy. He developed bronchial asthma 1 1/2 years post transplant. He presented with microhematuria and proteinuria 4 1/2 years post-transplant, which were due to unilateral left renal dysfunction. He developed type II, non-insulin-dependent diabetes mellitus 8 years post-transplant. A biopsy from the left kidney was not compatible with diabetic nephropathy. All these complications appear to be independently related to BMT, particularly TBI and/or splenic irradiation.

Suppression of alloreactivity with gamma delta T-cells: relevance to increased gamma delta T-cells following bone marrow transplantation

Several reports have shown that an increase in T-cell receptor gamma/delta-positive T-cells (gamma delta T-cells) have been observed following bone marrow transplantation. gamma delta T-cells expanded from peripheral blood mononuclear cells from normal volunteers were used to investigate the function of gamma delta T-cells in vitro. Peripheral blood mononuclear cells were cultured with synthetic ligand of gamma delta T-cells, monoethyl phosphates (MEP), for 7 days. MEP specifically expanded gamma delta T-cells. Expanded gamma delta T-cells from subject "B" were added to an A anti-B or A anti-C mixed lymphocyte culture (MLC) containing responder cells from subject "A" and irradiated stimulator cells from subjects "B" or "C". The cultures were harvested on day 6 and tested for cytotoxicity against stimulator-type Con A blasts. gamma delta T-cells from subject "B" specifically inhibit generation of allospecific cytotoxic T lymphocytes (CTL) in A anti-B MLC. The results indicate that gamma delta T-cells exhibit veto-type suppression of alloreaction. If the current experiments are also applicable in vivo, gamma delta T-cells originating from the donor after bone marrow transplantation may inhibit graft rejection by suppressing recipient anti-donor reactivity. gamma delta T-cells may be involved in the suppression of allogeneic reaction in vivo following allogeneic bone marrow transplantation.

Precise Molecular Constants for the 6Li2 A1Sigma+u-X1Sigma+g System by Sub-Doppler Polarization Spectroscopy

We report here new and more accurate molecular constants from sub-Doppler polarization spectroscopy of the A1Sigma+u-X1Sigma+g system of 6Li2 using single mode cw dye lasers. These new constants cover the range of vibrational levels from v" = 0-8 in the ground state and v' = 0-24 in the excited state. New molecular constants and RKR potential energy curves for the A1Sigma+u and X1Sigma+g states are given. The Te value for the A1Sigma+u state is 14068.043(34) cm-1. The analysis indicates that there is a noticeable breakdown of the Born-Oppenheimer approximation for the 6Li2 and 7Li2 isotopomers. Copyright 1998 Academic Press.

[Studies on pyridonecarboxylic acids as antibacterial agents. XIV. Synthesis and structure-activity relationships of 7,8-disubstituted-1-cyclopropyl-6-methyl-1,4-dihydro-4-oxo-3-quinoline carboxylic acids]

Eighteen pyridonecarboxylic acids, characterized by a methyl group at the C6-position instead of the usual fluorine atom, cyclopropyl at the N1-position, substituted amino groups at the C7-position, and some substituted groups (hydrogen, chlorine, nitro and amino) at the C8-position, were synthesized. The in vitro antibacterial activity of these compounds were tested, and the structure-activity relationships were also discussed. The results of the study showed that the activity of compounds 22 and 24 were less potent than that of ciprofloxacin against S. aureus, S. epidermidis, E. coli and P. aeruginosa, while they were 2-100 times more potent than ciprofloxacin against K. pneumoniae, S. marcescens, A. calcoacetous, E. aerogenes, S. typhi and S. typhimurium.

[Seroepidemiologic survey for A/PR/8/34 (H1N1) virus from Chinese residents]

A total of 414 serum specimens were collected from the residents with ages of < or = 20 year old in eight different parts of China for detecting antibody to A/PR/8/34(H1N1) influenza virus with HI test. Of them, 24 had antibody with HI titers > or = 20 to A/PR/8/34(H1N1) virus. These 24 specimens were tested with the same method using A/swine/Iowa/15/30 (H1N1), A/Guangxi/10/94(H1N1) and A/Beijing/53/97(H1N1) viruses. The results showed that except 5 of them had antibody with HI titers 20-40 to A/Beijing/53/97(H1N1) virus, the rest had antibodies with titers < 20 to the viruses for checking test. Therefore, the antibody to A/PR/8/34(H1N1) virus in the tested sera was not caused by cross reaction of antibodies against another H1N1 viruses. The results in this paper also further demonstrated that the A/PR/8/34(H1N1) like virus was circulating in residents in China.

Amantadine increases aromatic L-amino acid decarboxylase mRNA in PC12 cells

Amantadine is an antiviral agent that was unexpectedly found to cause symptomatic improvement in patients with Parkinsonism, although its mechanism of action remains to be elucidated. Aromatic L-amino acid decarboxylase (AADC) is a regulated enzyme that catalyzes the decarboxylation of 3,4-dihydroxyphenylalanine (L-Dopa). It may be especially important during L-Dopa therapy in Parkinsonism, during which it may be rate-limiting for the production of dopamine. This study reports the effects of amantadine on the gene expression of AADC in PC12 cells. It shows that amantadine induces AADC gene expression at concentrations of 10 and 100 microM after 24 hr of incubation. The results suggest that the stimulation of AADC mRNA by amantadine may be one of its effects on dopamine metabolism that may have relevance for potentiation of L-Dopa therapy in Parkinsonism.

The immunostimulatory effect of bio-active peptide from pollen on murine and human lymphocytes

The effects of bio-active peptide (BP) from buckwheat pollen and its synthetic analogues on murine and human lymphocytes and HL-60 cells were examined. Both natural and synthetic BP had the same effect in the lymphocyte blast transformation test. The proliferative response of HL-60 cells, co-cultured for 72 h with BP, was measured by the MTT method. BP had a stimulatory effect on HL-60 cell proliferation. The optical density (OD) value was 0.339+/-0.015, whereas, that of the control without BP was significantly lower (0.279+/-0.037; P < 0.05). The CD25 (IL-2Ralpha chain) positive cells of BP-stimulated human lymphocytes assessed by indirect immunofluorescence were 53.97+/-7.12% (1 microg/ml) and 42.53+/-4.4% (10 microg/ml), significantly higher than the control (11.77+/-1.88%; P < 0.001). The content of sIL-2R in the supernatant after culture with BP was determined by ELISA and was 1782.3+/-78.18 U/ml, lower than control 2381.2+/-99.9 U/ml. Taken together, our results showed that BP has an immunostimulatory effect on lymphocytes. The likely mode of BP action and the possibility of developing a novel immunomodulator are discussed.

L-deprenyl induces aromatic L-amino acid decarboxylase (AADC) mRNA in the rat substantia nigra and ventral tegmentum. An in situ hybridization study

L-Deprenyl is a complex drug, and number of mechanisms have been proposed to explain its effects. These include blockade of dopamine metabolism, amplification of dopamine responses, induction of superoxide dismutase or delaying apoptosis. Using in situ hybridization techniques, we have shown that L-deprenyl (5-10 mg/kg intraperitoneally, killed after 24 h) increases aromatic L-amino acid decarboxylase (AADC) mRNA levels in rat substantia nigraventral tegmental area. In human brain tissue, AADC is present at low levels, suggesting a possible rate-limiting role in monoamine synthesis. This is particularly important in parkinsonian patients, since the therapeutic efficacy of L-DOPA is attributed to its enzymatic decarboxylation to dopamine. The present findings support that one of the effects of L-deprenyl may be to facilitate the decarboxylation of L-DOPA by increasing the availability of AADC.

L-deprenyl potentiates NGF-induced changes in superoxide dismutase mRNA in PC12 cells

L-deprenyl protects neurons in a number of in vivo and in vitro models and it has been postulated that it ameliorates some neurodegenerative disorders. Superoxide dismutase (SOD) is one of the enzymes responsible for the inactivation of oxygen free radicals, and one of the mechanisms of the effect of L-deprenyl is thought to act by induction of SOD. In this study, PC12 cells were used to study the effect of L-deprenyl on gene regulation of SOD and its interaction with nerve growth factor (NGF). The results show that NGF induces SOD mRNA in a dose-dependent manner and that a similar effect was produced by L-deprenyl. In addition, L-deprenyl potentiates NGF effects. This study demonstrates that both L-deprenyl and NGF may be involved in common antioxidative mechanisms and that L-deprenyl may interact with neurotrophic factors.

[Genetic relationships of Nyctereutes procyonopides: as inferred from random amplified polymorphic DNA analysis]

Random amplified polymorphic DNAs (RAPDs) were used to investigate genetic relationships of eight raccoon dogs (Nyctereutes procyonopides). Using 28 arbitrary primers (10 bp), about 130 RAPD markers were observed in each individual. The average, maximum, and minimum genetic distance among 8 raccoon dogs are 11.20%, 14.93%, and 2.94% respectively. Our molecular phylogenetic trees constructed by UPGMA and NJ methods suggest that those 8 Chinese raccoon dogs may be divided into 4 clusters: (1) Guangxi raccoon dog, (2) Anhui raccoon dog, (3) Shaanxi raccoon dog, (4) Yunnan and Vietnam raccoon dog. Guangxi raccoon dog is more closely related to Anhui raccoon dog than to Yunnan-Vietnam raccoon dog. If the Yunnan-Vietnam cluster is a valid subspecies, it is reasonable to give the Guangxi, Anhui and Shaanxi clusters the same classification status as that of the Yunnan-Vietnam Cluster.

Cytokine-enhanced mixed lymphocyte reaction (MLR) in cord blood

Although in cord blood (CB) transplantation graft-versus-host disease (GVHD) is reported to be less severe, GVHD may occur even in patients with HLA-identical sibling donors. This result shows that HLA typing can not entirely predict GVHD. The standard MLR with CB cells was either normal or slightly reduced compared with adult peripheral blood (PB) cells. We used two manipulations to increase the responses of CB cells to allo-antigens. The first was to treat the stimulator cells with cytokines, and the second to amplify weak proliferative responses by adding exogenous cytokines to MLR cultures (modified MLR). The stimulator cells were treated with both interferon-gamma (IFN-gamma) and IL-4. The responder cells were treated with both IL-2 and tumour necrosis factor-alpha (TNF-alpha). It is still to be determined whether or not this cytokine-enhanced MLR could be a possible predictor of GVHD. However, using these cytokines, 90% of CB could recognize allo-antigens, even if the standard MLR was negative.

High-resolution 3D Bayesian image reconstruction using the microPET small-animal scanner

A Bayesian method is described for reconstruction of high-resolution 3D images from the microPET small-animal scanner. Resolution recovery is achieved by explicitly modelling the depth dependent geometric sensitivity for each voxel in combination with an accurate detector response model that includes factors due to photon pair non-collinearity and inter-crystal scatter and penetration. To reduce storage and computational costs we use a factored matrix in which the detector response is modelled using a sinogram blurring kernel. Maximum a posteriori (MAP) images are reconstructed using this model in combination with a Poisson likelihood function and a Gibbs prior on the image. Reconstructions obtained from point source data using the accurate system model demonstrate a potential for near-isotropic FWHM resolution of approximately 1.2 mm at the center of the field of view compared with approximately 2 mm when using an analytic 3D reprojection (3DRP) method with a ramp filter. These results also show the ability of the accurate system model to compensate for resolution loss due to crystal penetration producing nearly constant radial FWHM resolution of 1 mm out to a 4 mm radius. Studies with a point source in a uniform cylinder indicate that as the resolution of the image is reduced to control noise propagation the resolution obtained using the accurate system model is superior to that obtained using 3DRP at matched background noise levels. Additional studies using pie phantoms with hot and cold cylinders of diameter 1-2.5 mm and 18FDG animal studies appear to confirm this observation.

Whole cell patch-clamp study of putative vasomotor neurons isolated from the rostral ventrolateral medulla

A distinct subpopulation of neurons in the rostral and ventrolateral part of the medulla oblongata (RVL) plays a key role in controlling sympathetic vasomotor tone. To characterize these neurons under conditions in which all cell-to-cell interactions are eliminated, RVL neurons were acutely dissociated from 13- to 19-day old rats. Cells projecting to the upper thoracic segments were retrogradely labeled with fluorescent beads. Fifty-two percent (17/33) of examined spinally projecting neurons were catecholaminergic, as demonstrated by single-cell reverse transcription-polymerase chain reaction or immunocytochemistry. No spontaneous (capacitive) spikes were revealed in the tight seal cell-attached configuration. Whole cell recordings were made from 54 spinally projecting neurons using Cs(+)- or K(+)-containing pipettes. No spontaneous firing was observed in current-clamp mode with K(+)-based pipettes (membrane potential, -61.5 +/- 2.3 mV). Step depolarizations (300- or 400-ms pulses, up to 100 pA) evoked regular firing or one to four spikes. Several voltage-gated currents, resembling the transient and persistent Na+, delayed rectifier and low- and high-threshold Ca2+, were revealed in voltage-clamp mode. These results show that isolated spinally projecting RVL neurons display no pacemaker-like activity. Because data from the literature indicate that these neurons are capable of generating such activity under different experimental conditions, the factors responsible for different behavior need to be determined. Dissociated RVL neurons provide a useful new model for studying biophysical and other properties of neurons involved in blood pressure control.