Molecular phylogenetic diversity of bacteria and its spatial distribution in composts

AIMS

To investigate microbial diversity of swine manure composts in the initial stage and the spatial distribution due to gradient effect.

METHODS AND RESULTS

Samples in different locations of a composting pile were taken and analysed by using a culture-independent approach. Total community DNA was extracted and bacterial 16S rRNA genes were subsequently amplified, cloned, restriction fragment length polymorphism-screened and sequenced. Thirty-three unique sequence types were found among the 110 analysed positive clones from superstratum sample; 56 among 122 from middle-level sample and 32 among 114 from substrate sample, respectively. The sequences related to Clostridium sp. were most common in the composts. One hundred and thirteen out of 121 16S rDNA sequence types displayed homology with those in the GenBank database. Seven 16S rDNA sequence types were not closely related to any known species. The middle-level sample had the highest microbial diversity, containing unique sequences related to Lactosphaera pasteurii, Firmicutes sp., Aerococcus sp., Megasphaera sp. and Stenotrophomonas sp.

CONCLUSIONS

Pile temperature significantly affected microbial community in the initial stage of the composting. Microbial community in different locations is quite different resulting from gradient effect.

SIGNIFICANCE AND IMPACT OF THE STUDY

Results of this study reveal high bacterial diversity in manure composts, and provide molecular evidence to support gradient effect on microbial diversity in initial stage as well.

Sonoporation of cells for drug and gene delivery

Recent studies demonstrate that ultrasound can be used to deliver compounds into viable cells for potential targeted drug delivery and non-viral gene transfection, revealing new, advantageous possibilities. The delivery is facilitated through sonoporation, the formation of temporary pores in the cell membrane induced by ultrasound. Our study focuses on the study of sonoporation mechanisms in order to achieve optimal delivery outcome such as high delivery efficiency and minimal cell death. Using voltage clamp techniques, we obtained real-time measurements of sonoporation of single Xenopus oocytes in the presence of Optison, an agent consisting of albumin-shelled C3F8 gas bubbles. Ultrasound increased the transmembrane current as a direct result of decreased membrane resistance due to pore formation. The ability to real time monitor sonoporation of cells provides a novel and necessary tool for us to study the dynamic sonoporation process and obtain optimal delivery parameters. We confirmed the delivery of compound into cells by using markers such as plasmid GFP.

Fatty acids differentially affect serotonin receptor and transporter binding in the rat brain

The aim of this study was to examine the influence of different fat diets on serotonin receptor and transporter binding. Male Sprague-Dawley rats were fed a diet of either high saturated fat, omega-6 polyunsaturated fatty acid, omega-3 polyunsaturated fatty acid or low fat (control) for eight weeks. Using Beta-Imager quantification techniques, [(3)H]ketanserin, [(3)H]mesulergine and [(3)H]paroxetine binding to serotonin (5-HT)(2A), 5-HT(2C) receptors and 5-HT transporters (5-HTT) was measured throughout the brain in all four groups. All three high fatty acid diets influenced serotonin receptor binding, however the most pronounced effects were that compared with the low fat control group, i) 5-HT(2A) receptor binding was increased in the caudate putamen, but reduced in the mammillary nucleus in high saturated fat and high omega-6 polyunsaturated fatty acid diet groups; ii) 5-HT(2C) receptor binding was reduced in the mamillary nucleus of saturated fat group and reduced in prefrontal cortex of the omega-6 polyunsaturated fatty acid and omega-3 polyunsaturated fatty acid groups; and iii) 5-HTT binding was reduced in the hippocampus in the omega-6 polyunsaturated fatty acid group. Overall, the omega-6 polyunsaturated fatty acid diet exerted the most influence on serotonin receptor and transporter binding. These results may be of importance in relation to neuropsychiatric diseases such as schizophrenia, where associations between altered fatty acid levels and the serotonergic system have been made.

Corticosterone treatment of the chick embryo affects light-stimulated development of the thalamofugal visual pathway

By injecting a single 60 microg dose of corticosterone into the eggs of domestic chicks on day 18 of incubation, we have shown that elevated levels of this hormone affect the development of asymmetry in the visual projections from the thalamus to the Wulst regions in the left and right hemispheres of the forebrain. In vehicle-treated (control) embryos this visual pathway develops asymmetry in response to light stimulation during the final stages of incubation, when the embryo is oriented so that its left eye is occluded by its body and its right eye can be stimulated by light entering through the egg shell. Pre-hatching exposure to light leads to more projections from the left side of the thalamus to the right Wulst than from the right side of the thalamus to the left Wulst, as confirmed here by injection of the tracers Fluorogold and Rhodamine into the left and right Wulst followed by counting the number of labelled cell bodies in the thalamus (asymmetry greater in males than females). The chicks injected with corticosterone pre-hatching did not develop any group bias for asymmetry in response to light exposure before hatching. They were random with respect to presence/absence of lateralization and, when present, the lateralization was not as strong as in the controls and its direction was random. The corticosterone-treated group had fewer projections from the left side of the thalamus to the right Wulst than did the controls. The results are considered with respect to maternal deposits of the hormone in the yolk and pre-hatching stress of the embryo.

Comparison of water and lipid content measurements using diffuse optical spectroscopy and MRI in emulsion phantoms

We present a quantitative comparison of lipid and water signals obtained from broadband Diffuse Optical Spectroscopy (DOS) and Magnetic Resonance Imaging (MRI). DOS and MRI measurements were performed on an identical set of emulsion phantoms that were composed of different water/soybean oil fractions. Absolute concentrations of water and lipid ranging from 35-94% and 63-6%, respectively were calculated from quantitative broadband near-infrared (NIR) absorption spectra (650-1000 nm). MR images of fat and water were separated using the three-point Dixon technique. DOS and MRI measured water and lipid were highly correlated (R(2) = 0.98 and R(2) = 0.99, respectively) suggesting that these techniques are complementary over a broad range of physiologically relevant water and lipid values. In addition, comparison of DOS derived concentrations to the MRI "gold standard" technique validates our quantitation approach and permits estimation of DOS accuracy and sensitivity in vivo.

M1-M5 muscarinic receptor knockout mice as novel tools to study the physiological roles of the muscarinic cholinergic system

A large body of evidence indicates that muscarinic acetylcholine receptors (mAChRs) play critical roles in regulating the activity of many important functions of the central and peripheral nervous systems. However, identification of the physiological and pathophysiological roles of the individual mAChR subtypes (M(1)-M(5)) has proven a difficult task, primarily due to the lack of ligands endowed with a high degree of receptor subtype selectivity and the fact that most tissues and organs express multiple mAChRs. To circumvent these difficulties, we used gene targeting technology to generate mutant mouse lines containing inactivating mutations of the M(1)-M(5) mAChR genes. The different mAChR mutant mice and the corresponding wild-type control animals were subjected to a battery of physiological, pharmacological, behavioral, biochemical, and neurochemical tests. The M(1)-M(5) mAChR mutant mice were viable and reproduced normally. However, each mutant line displayed specific functional deficits, suggesting that each mAChR subtype mediates distinct physiological functions. These results should offer new perspectives for the rational development of novel muscarinic drugs.

Molecular characterization of a distinct potyvirus from whitegrass in China

Apotyvirus isolated from perennial whitegrass ( Pennisetum centrasiaticum Tzvel.) in North China was characterized at the molecular level. The 3' terminal nucleotide (nt) sequence of 1669 nt of the viral RNA genome has been determined, which covered the coding region of the C-terminal part of the large nuclear inclusion protein (NIb, RNA polymerase), capsid protein (CP) gene and the 3' nontranslated region (NTR). The CP gene consisted of 909 nt (including the stop codon) encoding 302 amino acid residues, and the 3' NTR was 241 nt in length excluding the polyadenylated tract. Sequence comparison of the amino acids of CPs showed that this virus was most closely related to Sorghum mosaic virus and Maize dwarf mosaic virus with percent identities of 77% to 78% while that of the 3' NTRs suggested that it was most closely related to Zea mosaic virus with identity of 72%. This virus isolate was to some extent closely related to other members of the Sugarcane mosaic virus subgroup of potyviruses for the CP amino acid sequences. Phylogenetic analyses of the sequences indicated that this virus isolate represented a distinct potyvirus, and the name Pennisetum mosaic virus (PenMV) is proposed.

Smad 3 may regulate follicular growth in the mouse ovary

Although Smad 3 is known to serve as a signaling intermediate for the transforming growth factor beta (TGFbeta) family in nonreproductive tissues, its role in the ovary is unknown. Thus, we used a recently generated Smad 3-deficient (Smad 3-/-) mouse model to test the hypothesis that Smad 3 alters female fertility and regulates the growth of ovarian follicles from the primordial stage to the antral stage. In addition, we tested whether Smad 3 affects the levels of proteins that control apoptosis, survival, and proliferation in the ovarian follicle. To test this hypothesis, breeding studies were conducted using Smad 3-/- and wild-type mice. In addition, ovaries were collected from Smad 3-/- and wild-type mice on Postnatal Days 2-90. One ovary from each animal was used to estimate the total number of primordial, primary, and antral follicles. The other ovary was used for immunohistochemical analysis of selected members of the B-cell lymphoma/leukemia-2 family of protooncogenes (Bax, Bcl-2, Bcl-x), proliferating cell nuclear antigen (PCNA), and cyclin-dependent kinase 2 (Cdk-2). The results indicate that Smad 3-/- mice have reduced fertility compared with wild type mice. The results also indicate that Smad 3 may not affect the size of the primordial follicle pool at birth, but it may regulate growth of primordial follicles to the antral stage. Further, the results indicate that Smad 3 may regulate the expression of Bax and Bcl-2, but not Bcl-x, Cdk-2, and PCNA. Collectively, these data suggest that Smad 3 may play an important role in the regulation of ovarian follicle growth and female fertility.

Targeted mutagenesis of Smad1 reveals an essential role in chorioallantoic fusion

The Smad family of intracellular signaling intermediates transduce signals downstream from the transforming growth factor beta (TGF-beta) family of receptor serine threonine kinases. The original member of this family, Smad1, has been shown to mediate signals from receptors for the bone morphogenetic proteins (BMPs), a large group of ligands in the TGF-beta superfamily that mediate important developmental events. We have targeted the Smad1 gene in mice and created mutants null at this locus. Smad1 mutant mice die at approximately 9.5 days postcoitum due to defects in allantois formation. In Smad1 mutant mice, the allantois fails to fuse to the chorion, resulting in a lack of placenta and failure to establish a definitive embryonic circulation. Although vasculogenesis is initiated in the mutant allantois, the vessels formed are disorganized, and VCAM-1 protein, a marker for distal allantois development, is not expressed. Smad1 null fibroblasts are still able to respond to BMP2, however, suggesting that the defect observed in the developing extraembryonic tissue is caused by a very specific loss of transcriptional activity regulated by Smad1. Our data further demonstrate that although highly similar structurally, Smad proteins are not functionally homologous.

[Microsatellite polymorphisms at the TNF locus in Hubei Han population]

OBJECTIVE

To investigate the distribution of tumor necrosis factor(TNF) microsatellite polymorphisms in Chinese.

METHODS

DNA was extracted from 164 unrelated healthy individuals' EDTA-blood. TNF microsatellite alleles were typed using PCR technique followed by high voltage denaturing PAGE with silver staining at the same time the PCR products were cloned and sequenced.

RESULTS

Thirteen alleles and forty kinds of genotypes were detected at the TNFa locus; two alleles and three kinds of genotypes at the TNFa locus. The polymorphism information contents (PIC) were 0.80 and 0.28 respectively no deviation from Hardy-Weinberg equilibrium was observed. Statistical analysis showed that the distribution of TNFa allele frequencies in Chinese Han population was significantly different from that in European Caucasian or in Japanese P<0.01. The result of sequencing revealed that the copy number of dinucleiotide repeats within the same TNF allele was not consistent with that in the reports from western countries.

CONCLUSION

There exists ethnic difference in the distribution of TNFa allele. Further investigations will be necessary to define more accurately and clearly the TNFa alleles.

[The effects of thrombopoietin and interleukin-11 on bone marrow megakaryocytic progenitors in patients with chronic idiopathic thrombocytopenic purpura in vitro]

OBJECTIVE

To observe the effects of recombinant human thrombopoietin (rhTPO) and rhTPO in combination with recombinant human interleukin-11(rhIL-11) on the megakaryocyte (MK) colony growth and maturation in patients with chronic idiopathic thrombocytopenic purpura (CITP) in vitro.

METHODS

Bone marrow (BM) mononuclear cells of 21 patients with CITP were cultured in plasma clot culture systems, to which were added rhTPO alone or rhTPO plus rhIL-11 over a range of concentrations. After 14 days, the MK colonies were stained by GP III a Mc Ab(SZ-21) and ABC-Kit and counted. The diameters and areas of the positive cells of GP III a were measured by BM-cell analysis system of MCDS-2010.

RESULTS

The diameters and areas of MK in CITP group were significantly lower than that in control group, P < 0.05. The addition of rhTPO to culture systems increased CFU-MK, total colonies and diameters and areas of MK in CITP patients. And this promoting effect was not dose-dependent. The optimal concentration of rhTPO was 10 ng/ml; in the group where 10 ng/ml rhTPO was used in combination with 20 ng/ml rhIL-11, the counts of CFU-MK, total colonies and the measurements of areas and diameters of MK increased significantly, compared with those in the group where rhTPO was used alone.

CONCLUSION

There are maturation dysfunctions of MK progenitors in patients with CITP. rhTPO alone or in combination with rhIL-11 can promote the proliferation and maturation of MK progenitors in patients with CITP and, moreover, the combination of the two cytokines has more significant promoting effects, compared to rhTPO alone.

Antagonistic effects of Smad2 versus Smad7 are sensitive to their expression level during tooth development

Members of the transforming growth factor-beta (TGF-beta) superfamily regulate cell proliferation, differentiation, and apoptosis, controlling the development and maintenance of most tissues. TGF-beta signal is transmitted through the phosphorylation of Smad proteins by TGF-beta receptor serine/threonine kinase. During early tooth development, TGF-beta inhibits proliferation of enamel organ epithelial cells but the underlying molecular mechanisms are largely unknown. Here we tested the hypothesis that antagonistic effects between Smad2 and Smad7 regulate TGF-beta signaling during tooth development. Attenuation of Smad2 gene expression resulted in significant advancement of embryonic tooth development with increased proliferation of enamel organ epithelial cells, while attenuation of Smad7 resulted in significant inhibition of embryonic tooth development with increased apoptotic activity within enamel organ epithelium. These findings suggest that different Smads may have differential activities in regulating TGF-beta-mediated cell proliferation and death. Furthermore, functional haploinsufficiency of Smad2, but not Smad3, altered TGF-beta-mediated tooth development. The results indicate that Smads are critical factors in orchestrating TGF-beta-mediated gene regulation during embryonic tooth development. The effectiveness of TGF-beta signaling is highly sensitive to the level of Smad gene expression.

RIM4 encodes a meiotic activator required for early events of meiosis in Saccharomyces cerevisiae

RIM4 was previously found to be required for both the IME1- and IME2-dependent pathways of meiotic gene expression in Saccharomyces cerevisiae. We now demonstrate that RIM4 is also required for meiotic division and recombination. Furthermore, rim4Delta mutants show defects in premeiotic DNA synthesis, which can be suppressed by deletion of the SIC1 gene, which encodes a Cdk inhibitor. Expression of RIM4 is induced early in meiosis, and is dependent on IME1 but not IME2. Indeed, RIM4 itself is essential for the meiotic expression of IME2. These results suggest that RIM4 is epistatic to IME2, and is required for multiple steps during sporulation. In agreement with this interpretation, overexpression of RIM4 induces low levels of sporulation in rich medium.

Motor deficits in fibroblast growth factor receptor-3 null mutant mice

Fibroblast growth factor receptor-3 (FGFR-3) regulates aspects of bone development. Mutations in the FGFR-3 gene (Fgfr3) in humans and mice produce vertebral abnormalities and bone deformities. The present study evaluated the behavioural concomitants of the Fgfr3-/- mutation. Fgfr3-/- null mutant mice displayed severe impairments of motor abilities as detected on the rotarod, wire hang and open field tests. Absence of prepulse inhibition of acoustic startle was seen at prepulse levels from 74 to 86 dB. The motor deficits appear to be a direct and predicted consequence of the skeletal kyphosis, scoliosis and long bone overgrowth previously reported in Fgfr3 null mutant mice. The behavioural phenotype displayed by these mutant mice complements their anatomical, physiological and biochemical phenotypes, to complete the characterization of the functional outcome of a single gene mutation. Simple, robust behavioural symptoms, such as poor rotorod performance in Fgfr3 knockout mice, can provide useful surrogate markers to evaluate pharmacological treatments and gene therapies for human genetic diseases.

[Association of tumor necrosis factor microsatellite polymorphism with chronic atrophic gastritis and gastric adenocarcinoma]

OBJECTIVE

To investigate whether TNFd and TNFe microsatellite polymorphisms correlate with chronic atrophic gastritis and gastric adenocarcinoma in Chinese Han population.

METHODS

In 164 healthy controls, 53 patients with chronic atrophic gastritis, and 56 patients with gastric adenocarcinoma, TNFd and TNFe microsatellite alleles were typed using PCR technique, followed by high-voltage denaturing PAGE, with silver staining. At the same time, the PCR products were cloned and sequenced.

RESULTS

Fight alleles at the TNFd locus and four alleles at the TNFe locus were detected. A new allele was found and identified, its accession number of Genebank is AF315593. Statistical analysis showed that there existed a very strong linkage equilibrium between TNFd8 and TNFe4 allele. No difference was observed between patients and healthy controls in the distribution of alleles at the TNFd and TNFe loci (P > 0.05). The frequence of d2/d6 genotype was significantly higher in patients with gastric adenocarcinoma than in healthy individuals (P = 0.028). d2/d6 genotype wasn't related to age or gender or grade of differentiation or clinicopathologic stage in gastric adenocarcinoma.

CONCLUSION

d8e4 haplotype appears to be specific of Chinese population. d2/d6 genotype is associated with the susceptibility to gastric adenocarcinoma.

[Vacuolation effect of Helicobacter pylori on gastric epithelial cells]

This study was designed to observe vacuolation effect of Helicobacter pylori on gastric epithelial cells. The H. pylori isolates derived from patients with peptic ulcer, chronic gastritis and gastric cancer were plated on common selective medium and their vacuolation effects on SGC-7901 cells were compared. The percentage of H. pylori(Tox+) strain in clinical isolates from different gastroduodenal diseases had no significant difference. The toxicity of the H. pylori (Tox+) strain from peptic ulcer was significantly higher than that from chronic gasritis.

[The relativity study of thrombopoietin and chronic idiopathic thrombocytopenic purpura]

OBJECTIVE

To explore the relationship between thrombopoietin (Tpo) levels and reticulated platelet (RP), blood platelet count (BPC), maturity of megakaryocytes in patients with chronic idiopathic thrombocytopenic purpura (CITP), and the prediction evaluation according to Tpo levels.

METHODS

Serum level of Tpo was measured by a sandwich-ELISA procedure, RP by flow cytometry after stained with thizole orange (TO), and maturity of megakaryocytes by laser scanning confocal microscopy (LSCM).

RESULTS

The serum level of Tpo was (204.05 +/- 65.70) ng/L in 23 normal controls and (345.46 +/- 222.23) ng/L in 33 patients with CITP, being no significant difference between the two groups (P > 0.05). Compared with controls, serum Tpo levels in 22 aplastic anemia(AA) patients [(1427.62 +/- 468.84) ng/L] and 10 acute myelogenous leukemia (AML) patients [(596.09 +/- 462.95) ng/L] were increased significantly (P < 0.05). The RPC was significantly lower in AA and AML patients (P < 0.05). The RP% was increased significantly in CITP and AML patients (P < 0.05). The Tpo level was higher in CITP patients with no response to glucocorticoid therapy than in those with response (P < 0.05).

CONCLUSION

Serum level of Tpo was not increased in patients with CITP. The RP%, RPC and Tpo levels could reflect thrombocytopoiesis and differentiate the causes of thrombocytopenia. The serum level of Tpo could be useful in prediction of the response to therapy in CITP patients.

ADY1, a novel gene required for prospore membrane formation at selected spindle poles in Saccharomyces cerevisiae

ADY1 is identified in a genetic screen for genes on chromosome VIII of Saccharomyces cerevisiae that are required for sporulation. ADY1 is not required for meiotic recombination or meiotic chromosome segregation, but it is required for the formation of four spores inside an ascus. In the absence of ADY1, prospore formation is restricted to mainly one or two spindle poles per cell. Moreover, the two spores in the dyads of the ady1 mutant are predominantly nonsisters, suggesting that the proficiency to form prospores is not randomly distributed to the four spindle poles in the ady1 mutant. Interestingly, the meiosis-specific spindle pole body component Mpc54p, which is known to be required for prospore membrane formation, is localized predominantly to only one or two spindle poles per cell in the ady1 mutant. A partially functional Myc-Pfs1p is localized to the nucleus of mononucleate meiotic cells but not to the spindle pole body or prospore membrane. These results suggest that Pfs1p is specifically required for prospore formation at selected spindle poles, most likely by ensuring the functionality of all four spindle pole bodies of a cell during meiosis II.