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Biomedical subjects

Lu Zhang

Publications and source records attributed to Lu Zhang.

At least 55 records · Page 3Linked to original sources

Epithelial expression of SHH signaling pathway in odontogenic tumors.

Sonic hedgehog (SHH) signaling pathway plays a critical role in tooth development. Recent studies indicate that SHH signaling pathway activation occurs both in the odontogenic cyst and ameloblastoma. However, the association of SHH pathway with other subtypes of odontogenic tumor is not well documented. The objective of this paper is to investigate the protein distribution of SHH and its receptor PTC, SMO and transcription factor GLI1 in various odontogenic tumors. Odontogenic tumor tissues including 34 epithelial derived, 24 epithelial-mesenchymal derived, and 26 mesenchymal derived were examined by immunohistochemistry for SHH, PTC, SMO and GLI1. Immunoreactivity for SHH, PTC, SMO and GLI1 was detected in both epithelial derived odontogenic tumors and epithelial-mesenchymal derived odontogenic tumors with or without dental hard tissue formation. Mesenchymal derived odontogenic tumors showed no positive staining except for the focal epithelial cells in island or cord forms within the central portion of the tumor. The protein expression of SHH signaling pathway in malignant odontogenic tumors was no stronger than that in benign tumors. Each of the genes in the pathway was expressed in similar patterns in the same tumor subtype. SHH, PTC, SMO and GLI1 were detected more in the cytoplasm of the epithelial cells than in stromal cells. Immunoreactivity for GLI1 was also detected in the base membrane of the tumor cells. The findings suggest SHH, PTC, SMO and GLI1 protein are predominantly located in epithelial components in various odontogenic tumors and might participate in the proliferation of epithelial components of odontogenic tumors.

Hedgehog Proteins↗

Expression and purification of the synthetic preS1 gene of Hepatitis B Virus with preferred Escherichia coli codon preference.

To produce high levels of hepatitis B virus (HBV) preS1 protein at low cost, a DNA fragment encoding the preS1 region, residues 1-119, of HBV adr subtype was synthesized by overlapping-PCR according to Escherichia coli (E. coli) B preferred codon usage. The synthetic preS1 gene (spreS1) was cloned into the bacterial expression vector pET-30a and transferred into the expression strain E. coli BL21(DE3). Recombinant preS1 protein with an N-terminal His6 tag was expressed at high levels in soluble form, yielding about 44% of the total cellular protein. This technique overcomes problems that existed in previously reported expression systems of preS1 or its epitope, i.e., low-level expression or expression in inclusion bodies. Using this His-tagged preS1 expression system, recombinant protein was purified by single-step affinity chromatography on a Ni-NTA column resulting in a yield was about 28 mg recombinant protein per liter culture. Furthermore, Western blotting and indirect ELISA analysis demonstrate that the reactivity of preS1-specific antibody is comparable between the recombinant and commercialized preS1 protein. Thus, our improved expression system could be used for practical, low-cost large-scale production of recombinant preS1 without refolding steps.

Base Sequence↗

Epithelioid hemangioma in the oral mucosa: a clinicopathological study of seven cases and review of the literature.

To investigate the clinicopathological characteristics and biologic behavior of epithelioid hemangioma in oral mucosa, the clinical features and pathological findings of seven cases of epithelioid hemangioma were reviewed, and all sections were examined by immunohistochemistry. There were 4 males and 3 females ranged from 8 to 65 years (mean 39.7 years). Sites of origin included the tongue (n = 4), lips (n = 2), and palates (n = 1). Five lesions presented as a solitary mass. Three patients had history of minimal trauma. Histopathologically, well-formed but often immature vessels lined by plump epitholid endothelial cells with prominent inflammatory components were observed. Immunohistochemical staining revealed that tumour cells were positive for Vimentin, FVIIIRAg and CD34. All the cases were negative to S-100 protein and EMA. One case recurred after surgical excision, while none of them metastasized. Epithelioid hemangioma is a benign vascular anomaly, and has close relationship with local trauma. The differential diagnosis is usually based upon histopathological findings.

Adult↗

[Protection of gastric mucosa against steroids-induced damage by teprenone].

OBJECTIVE: To estimate the effects of teprenone on protecting gastric mucosa against steroids-induced damage. METHODS: Fifty male Sprague-Dawley rats were randomly divided into 5 equal groups: normal control group, undergoing gastric infusion of normal saline for 7 days and fasting since the 4 th day for 4 days; model control group, undergoing gastric infusion of normal saline for 7 days and fasting and hypodermal injection of prednisolone 40 mg/kg since the 4 th day for 4 days; low dose teprenone group, undergoing gastric infusion of teprenone 50 mg/kg for 7 days and fasting and hypodermal injection of prednisolone 40 mg/kg since the 4 th day; middle dose teprenone group, undergoing gastric infusion of teprenone 50 mg/kg for 7 days and fasting and hypodermal injection of prednisolone 40 mg/kg since the 4 th day; and high dose teprenone group, undergoing gastric infusion of teprenone 200 mg/kg for 7 days and fasting and hypodermal injection of prednisolone 40 mg/kg since the 4 th day. Samples of gastric mucosa were taken out 24 hours after the last drug administration to calculate the ulcer index and observe the histological changes. Blood samples were collected from the abdominal cardinal vein. The levels of plasma ET-1 and prostaglandin E2 were examined by radioimmunoassay. Serum level of nitric oxide (NO) was determined by Griess method. RESULTS: In the model control group, the ulcer index, grade of histological lesions and ET-1 level increased significantly compared with the normal control group (44.5 vs. 0, 5.5 vs. 0, and 399 pg/ml +/- 74 pg/ml vs. 279 pg/ml +/- 56 pg/ml, all P < 0.01), the PGE(2) level decreased significantly. (154 pg/mg +/- 83 pg/mg vs 337 pg/mg +/- 112 pg/mg, P < 0.01), and the NO level did not changed significantly. In the 3 teprenone groups, the ulcer index decreased (32.5, 23.0, and 23.0 vs. 44.5, all P < 0.01), grade of histological lesions decreased (3.0, 3.0, and 1.5 vs. 5.5, all P < 0.01), ET-1 level decreased (299 pg/ml +/- 99 pg/ml, 284 pg/ml +/- 85 pg/ml, and 189 pg/ml +/- 32 pg/ml vs. 399 pg/ml +/- 74 pg/ml, P < 0.05, P < 0.01, and P < 0.01), the No level increased (56 micromol/L +/- 16 micromol/L, 62 micromol/L +/- 12 micromol/L, and 83 micromol/L +/- 9 micromol/L vs. 27 micromol/L +/- 5 micromol/L, all P < 0.01), and the PGE(2) level increased (190 pg/mg +/- 58 pg/mg, 196 pg/mg +/- 35 pg/mg, 241 pg/mg +/- 65 pg/mg vs. 154 pg/mg +/- 83 pg/mg, P > 0.05, P > 0.05, and P < 0.05) compared with the model control group. CONCLUSION: Teprenone is a beneficial cytoprotective agent of gastric mucosa. Pretreatment with teprenone has gastroprotective effect against steroids-induced mucosal damage to a certain extent with a mechanism related to ET-1, NO, and PGE(2) concentrations in blood or gastric mucosa.

Animals↗

Purification and characterization of a functionally active Mycobacterium tuberculosis pyrroline-5-carboxylate reductase.

Pyrroline-5-carboxylate reductase (P5CR) plays an important role in the survival of Mycobacterium tuberculosis and is related to virulence of this pathogen. RT-PCR analysis indicated that proC, encoding P5CR, was expressed at the transcriptional level cultured in vitro. The His-rMtP5CR with an N-terminal His-tag (His-rMtP5CR) was firstly purified in Escherichia coli and rMtP5CR was obtained by removal of the N-terminal fusion partner using enterokinase. His-rMtP5CR had considerable beta-pleated sheet analyzed by circular dichroism spectroscopy. The effect of pH, temperature, cations, denaturants, and detergents on the purified enzyme activity and stability was characterized. The N-terminal fusion partner was found to have very little effect on the biochemical properties of P5CR.

Cells, Cultured↗

Epigenetic modulation of retinoic acid receptor beta2 by the histone deacetylase inhibitor MS-275 in human renal cell carcinoma.

PURPOSE: Histone deacetylase (HDAC) inhibitors have been shown to reverse epigenetic repression of certain genes, including retinoic acid receptor beta2 (RARbeta2). In this study, we examined whether RARbeta2 expression is repressed in human renal cell carcinoma (RCC) and whether the HDAC inhibitor MS-275 may revert its epigenetic repression. EXPERIMENTAL DESIGN: Six human tumor RCC cell lines were analyzed for RARbeta2 gene expression and for methylation and acetylation status at the promoter level. Modulation of RARbeta2 expression and correlation with antitumor activity by combination of MS-275 with 13-cis-retinoic acid (CRA) was assessed in a RARbeta2-negative RCC cell line. RESULTS: RARbeta2 expression was either strongly present, weakly expressed, or absent in the RCC cell lines analyzed. Methylation-specific PCR indicated that the RARbeta2 promoter was partially methylated in three of the cell lines. CRA treatment did not inhibit clonogenic growth in the RARbeta2-negative cell line RCC1.18, whereas MS-275 induced a dose-dependent inhibitory effect. A greater inhibitory effect was observed with combination treatment (MS-275 + CRA). Treatment with MS-275 was associated with histone acetylation at the promoter level and synergistic gene reexpression of RARbeta2 in combination with CRA. RARbeta2 reexpression was associated with synergistic induction of the retinoid-responsive gene HOXA5. In vivo, single-agent CRA treatment showed no significant effect, whereas MS-275 and the combination induced a regression of RCC1.18 tumor xenografts. Discontinuation of treatment produced tumor recurrence in MS-275-treated mice, whereas animals treated with the combination remained tumor free. CONCLUSION: The HDAC inhibitor MS-275 seems to revert retinoid resistance due to epigenetic silencing of RARbeta2 in a human RCC model and has greater antitumor activity in combination with CRA compared with single agents. Thus, the combination of HDAC inhibitors and retinoids may represent a novel therapeutic approach in patients with RCC.

Animals↗

Light-harvesting and photoisomerization in benzophenone and norbornadiene-labeled poly(aryl ether) dendrimers via intramolecular triplet energy transfer.

A series of benzophenone (BP) and norbornadiene (NBD)-labeled poly(aryl ether) dendrimers (Gn-NBD), generations 1-4, were synthesized, and their photophysical and photochemical properties were examined. The phosphorescence of the peripheral BP (donor) chromophore was efficiently quenched by the NBD (acceptor) group attached to the focal point. Time-resolved spectroscopic measurements indicated that the lifetime of the triplet state of the BP chromophore was shortened due to the proximity of the NBD group. Selective excitation of the BP chromophore resulted in isomerization of the NBD group to quadricyclane (QC). All of these observations suggest that an intramolecular triplet energy transfer occurs in Gn-NBD molecules. The light-harvesting ability of these molecules increases with generation due to an increase in the number of peripheral chromophores. The energy transfer efficiencies are ca. 0.97, 0.54, 0.45, and 0.37 for generations 1-4, respectively, and the rate constant of the triplet-triplet energy transfer is ca. 10(6)-10(7) s(-1), which decreases inconspicuously with increasing generation. The intramolecular triplet energy transfer is proposed to proceed mainly via a through-space mechanism involving the closest donor (folding back conformation) and acceptor groups.

Journal Article↗

Repeated cocaine administration induces gene expression changes through the dopamine D1 receptors.

Drug addiction involves compulsive drug-seeking and drug-taking despite known adverse consequences. The enduring nature of drug addiction suggests that repeated exposure to abused drugs leads to stable alterations that likely involve changes in gene expression in the brain. The dopamine D1 receptor has been shown to mediate the long-term behavioral effects of cocaine. To examine how the persistent behavioral effects of cocaine correlate with underlying changes in gene expression, we have used D1 receptor mutant and wild-type mice to identify chronic cocaine-induced gene expression changes mediated via the D1 receptors. We focused on the caudoputamen and nucleus accumbens, two key brain regions that mediate the long-term effects of cocaine. Our analyses demonstrate that repeated cocaine administration induces changes in the expression of 109 genes, including those encoding the stromal cell-derived factor I, insulin-like growth factor binding protein 6, sigma 1 receptor, regulators of G-protein signaling protein 4, Wnt1 responsive Cdc42 homolog, Ca2+/calmodulin-dependent protein kinase II alpha subunit, and cyclin D2, via the D1 receptors. Moreover, the seven genes contain AP-1 binding sites in their promoter regions. These results suggest that genes encoding certain extracellular factors, membrane receptors and modulators, and intracellular signaling molecules, among others, are regulated by cocaine via the D1 receptor, and these AP-1 transcription complex-regulated genes might contribute to persistent cocaine-induced behavioral changes.

Animals↗

Neuropsychological test performance in healthy elderly volunteers before and after donepezil administration: a randomized, controlled study.

Neuropsychological performance was examined in healthy elderly participants administered the cholinesterase inhibitor donepezil. Of principal interest was examination of the sensitivity of a series of neuropsychological measures to detect cognitive changes after drug administration using typical phase I research parameters (eg, a small sample over a short treatment period). In this double-blind parallel study over a period of 6 weeks, 26 healthy elderly participants (aged 55 to 75 years) were randomized into 1 of 2 arms (14 donepezil and 12 placebo) and completed 14 days of donepezil (5 mg, twice a day) or placebo (twice a day). A battery of neuropsychological tests was administered on days 0, 14 (prerandomization), 28 (end of treatment), and 42 (washout). After 2 weeks of donepezil treatment (day 28), subjects in the donepezil group performed slightly but significantly worse on 2 tests of speed, attention, and short-term memory (P < 0.05) compared with the placebo group. No significant improvement in performance was present on any test during treatment with donepezil. These results are consistent with a previous study in healthy young participants in which transient mild worsening on some cognitive tests during donepezil administration was observed, possibly caused by perturbation of an already optimized cholinergic system in healthy participants. These results are important to consider when designing clinical development plans for putative cognitive-enhancing drugs; in addition, these results raise questions about when the optimal point to begin treatment is for patients who have not yet met criteria for dementia.

Aged↗

[Studies on fluorescent properties of multi-walled carbon nanotubes before and after concentrated nitric acid treatment].

Fluorescent properties of multi-walled carbon nanotubes (MWNTs) before and after concentrated nitric acid treatment were studied. The results show that both multi-walled carbon nanotubes (MWNTs) and treated multi-walled carbon nanotubes (t-MWNTs) could emit fluorescence; compared with MWNTs, fluorescence from t-MWNTs is stronger and fluorescent emission peak from t-MWNTs blue shifts slightly to short-wavelength. Luminescence from MWNTs could be related to the trapping of excitation energy at defect sites and the energy bandgap between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO). Treating MWNTs with concentrated nitric acid could introduce more defects on MWNTs and make MWTNs trap more excitation energy, leading to a fluorescence enhancement of t-MWTNs; in addition, the energy bandgap between LUMO and HOMO increases with length decreasing of MWNT, and the shortening of MWNT caused by concentrated nitric acid treatment could make energy bandgap between LUMO and HOMO increase, resulting in a slight blue shift of fluorescent emission peak of t-MWTNs to short wavelength.

Fluorescence↗

[Chromophoric dissolved organic matter absorption characteristics with relation to fluorescence in typical macrophyte, algae lake zones of Lake Taihu].

Chromophoric dissolved organic matter (CDOM) represents one of the primary light-absorbing species in natural waters and plays a critical in determining the aquatic light field. CDOM shows a featureless absorption spectrum that increases exponentially with decreasing wavelength, which limits the penetration of biologically damaging UV-B radiation (wavelength from 280 to 320 nm) in the water column, thus shielding aquatic organisms. CDOM absorption measurements and their relationship with dissolved organic carbon (DOC), and fluorescence are presented in typical macrophyte and algae lake zone of Lake Taihu based on a field investigation in April in 2004 and lab analysis. Absorption spectral of CDOM was measured from 240 to 800 nm using a Shimadzu UV-2401PC UV-Vis recording spectrophotometer. Fluorescence with an excitation wavelength of 355 nm, an emission wavelength of 450 nm is measured using a Shimadzu 5301 spectrofluorometer. Concentrations of DOC ranged from 6.3 to 17.2 mg/L with an average of 9.08 +/- 2.66 mg/L. CDOM absorption coefficients at 280 nm and 355 nm were in the range of 11.2 - 32.6 m(-1) (average 17.46m(-1) +/- 5.75 m(-1) and 2.4 - 8.3 m(-1) (average 4.17m(-1) +/- 1.47 m(-l)), respectively. The values of the DOC-specific absorption coefficient at 355 nm ranged from 0.31 to 0.64 L x (mg x m)-1. Fluorescence emission at 450 nm, excited at 355 nm, had a mean value of 1.32nm(-1) +/- 0.84 nm(-1). A significant lake zone difference is found in DOC concentration, CDOM absorption coefficient and fluorescence, but not in DOC-specific absorption coefficient and spectral slope coefficient. This regional distribution pattern is in agreement with the location of sources of yellow substance: highest concentrations close to river mouth under the influence of river inflow, lower values in East Lake Taihu. The values of algae lake zone are obvious larger than those of macrophyte lake zone. In Meiliang Bay, CDOM absorption, DOC concentration and fluorescence tend to decreasing from inside to mouth of the Bay. The results show a good correlation between CDOM absorption and DOC coefficients during 280 - 500 nm short wavelength intervals. The R-square coefficient between CDOM absorption and DOC concentration decreases with the increase of wavelength from 280 to 500 nm. The significant linear regression correlations between fluorescence, DOC concentration and absorption coefficients were found at 355 nm. The exponential slope coefficients ranged from 13.0 to 16.4 microm(-1) with a mean value 14.37microm(-1) +/- 0.73microm(-1), 17.3microm(-1) - 20.3microm(-1) with a mean value 19.17microm(-1) +/- 0.84microm(-1) and 12.0microm(-1) - 15.8microm(-1) with a mean value 13.38microm(-1) +/- 0.82microm(-1) over the 280 - 500 nm, 280 - 360 nm and 360 - 440 nm intervals.

Absorption↗

[Repair of articular cartilage defects with "two-phase" tissue engineered cartilage constructed by autologous marrow mesenchymal stem cells and "two-phase" allogeneic bone matrix gelatin].

OBJECTIVE: To investigate the effect of "two-phase" tissue engineered cartilage constructed by autologous marrow mesenchymal stem cells(MSCs) and allogeneic bone matrix gelatin(BMG) in repairing articular cartilage defects. METHODS: Thirty-two New Zealand white rabbits were involved in the experiment. "Two-phase" allogeneic BMG scaffold (one side of porous cancellous bone and the other side of cortical bone; 3 mm both in diameter and in thickness) was prepared from iliac bone and limb bone of 5 rabbits by sequentially chemical method. The MSCs were separated from 18 New Zealand white rabbits and induced to express chondrocytic phenotype. The chondrocyte precursor cells were seeded onto "two-phase" allogeneic BMG to construct tissue engineering cartilage. Masson's trichrome staining, PAS staining and scanning electronic microscopic observation were carried out at 1, 3 and 5 weeks. The defects of full thickness articular cartilage (3 mm both in diameter and in depth) were made at both sides of femoral medial condyles in 27 rabbits (including 18 of separated MSCs and the remaining 9). The defects were repaired with the tissue engineered cartilage at the right side (group A, n = 18), with BMG at the left side (group B, n = 18), and without any implant at both sides in the remaining 9 rabbits as a control (group C, n = 18). After 1, 3 and 6 months, the 6 specimens of femoral condyles were harvested in 3 groups, respectively. Gross observation, Masson's trichrome and Alcian blue staining, modified Wakitani scoring and in situ hybridization of collagen type I were carried out to assess the repair efficacy of tissue engineered cartilage. RESULTS: The "two-phase" BMG consisted of the dense cortical part and the loose cancellous part. In cancellous part, the pore size ranged 100-800 microm, in which the chondrocyte precursor cells being induced from MSCs proliferated and formed the cell-rich cartilaginous part of tissue engineered cartilage. In cortical part, the pore size ranged 10-40 microm, on which the cells arranged in a layer and formed the hard part of subchondral bone. After 1 month of transplantation, the cartilage and subchondral bone were regenerated in group A; during observation, the regenerated cartilage gradually thinned, but defect was repaired and the structure of the articular surface and subchondral bone was in integrity. In groups B and C, defects were not repaired, the surrounding cartilage of defect was abrased. According to the modified Wakitani scoring, the indexes in group A were significantly higher than those in group B and C (P < 0.01) except the thickness of cartilage at 6 months. The positive cell rate of in situ hybridization for collagen type II in group A was also higher than those in groups B and C (P < 0.01). CONCLUSION: "Two-phase" allogeneic BMG is a prospective scaffold for tissue engineered cartilage, which combines with autologous chondrocyte precursor cells induced from MSCs to construct the tissue engineering cartilage. The tissue engineered cartilage can repair defects of articular cartilage and subchondral bone.

Animals↗

[Gene expression of transcription regulator LMO 4 in tooth morphogenesis].

OBJECTIVE: To investigate the expression of transcription regulator LMO4 mRNA in the developing mouse molar and compare the expression pattern of LMO4 with that of Shh signaling molecule. METHODS: Wild-type embryos used in this study (E11.5-P1.5) were generated by mating Kun-Ming mice. The expression pattern of LMO4 during organ development was carried on by whole-mount in situ hybridization. The expression patterns of LMO4 and Shh mRNA during molar development were analysed by section in situ hybridization. Immunohistochemical staining of PCNA was carried on by SP method. RESULTS: LMO4 mRNA was widespread at early embryonic stages (E11.5) with positive hybridization signal in the mandibular reason, limb bud, brain, epidermis and somites revealed by whole-mount in situ hybridization. Section in situ hybridization showed that LMO4 was expressed in the tooth bud, the two tips of the enamel organ and the cervical loop from E13.5 to E16.5. While Shh was localized in the enamel knot on E14.5. On E18.5-P1.5, LMO4 transcripts were distributed in the ameloblast and the stratum intermedium. On E13.5-E16.5, the tooth bud cells and the cervical loop cells were PCNA positive. These were the same regions that showed LMO4 mRNA expression. CONCLUSIONS: LMO4 was confined to the dental epithelium and had spatial temporal expression patterns during tooth morphogenesis. The expression patterns of LMO4 and Shh were similar. In early tooth development, LMO4 might regulate cell proliferation. In late tooth development, it might participate in the ameloblast differentiation.

Adaptor Proteins, Signal Transducing↗

[Recycling rate of N and P through a feeding-composting cycle and their recoveries in agro-ecosystems].

A five-year experiment indicated that the average loss rate of N and P in harvested products through a feeding-composting cycle was about 50% and 15%, respectively. Under high yield condition, the amount of recycled N and P from 80% harvested products and through a feeding-composting cycle in farming systems was about 37 - 51 and 8 -14 kg x hm(-2), equivalent to 25% - 34% of N and 32% - 56% of P from chemical fertilizers applied each year to the systems. The apparent recoveries of N and P in organic manure increased with the prolongation of fertilization, indicating a synergetic residual effect existed, and was 61% and 39% in average in the five-year experiment. The use of nutrients recycled in the farming systems could not only improve soil fertility, but also increase the recoveries of nutrients and reduce the use of chemical fertilizers.

Agriculture↗

[Monitoring CML28 mRNA levels in patients before and after HSCT by real-time quantitative RT-PCR].

The purpose of this study was to establish a SYBR Green I real-time quantitative RT-PCR method for investigating the correlation between CML28 mRNA expression levels and relapse of leukemia after allo-hematopoietic stem cell transplantation (HSCT). pcDNA3.1HisA-CML28 plasmid had been constructed as the standard template. Serial monitoring of CML28 mRNA levels by SYBR Green I real-time quantitative RT-PCR technique was performed in 14 patients, including 10 patients with CML and 3 patients with AML, 1 patient with Ph(+) ALL. The results showed that the sensitivity of the established method was at 10(-4) (0.05 ng) level, with interassay variation and intraassay variation of standard samples both below 10%. The CML28 was highly expressed in AML and CML-BP or AP. CML28 level in newly diagnosed group was (6.58 +/- 2.34) x 10(-2), in pre-conditioning regimen group was (2.19 +/- 0.32) x 10(-2), in group that 1 month after HSCT was (1.35 +/- 1.28) x 10(-2), in group that 3 months after HSCT was (4.57 +/- 6.39) x 10(-3). CML28 can be detected 3 months after HSCT in 1 patient with CML-CP and 3 patients with CML-AP or BC. 2 of them with low level (<2 x 10(-2)) survived without relapse, the other 2 case with high level (>2 x 10(-2)) relapsed within one year, 1 case died and 1 case received the second time HSCT, CML28 level decreased rapidly after HSCT, but still higher than 2 x 10(-2) and relapse has taken place. The conclusions was made that CML28 mRNA level is obviously correlated with the development of leukemia. Serial quantification of CML28 mRNA levels are necessary for HSCT recipients, and more informative than a single detection. Using of this assay to evaluate MRD in the patients received HSCT is helpful for prediction of relapse.

Adolescent↗

[Research on mineralization process of organic phosphorus in black soil in Northeast China].

Buried bag and incubation experiments were conducted to study mineralization process of organic phosphorus in black soil in Northeast China under different time sequences. The results showed that both the content and mineralized velocity of organic P decreased gradually as time went on, the cumulative mineralized rate increased step by step, whether it was used by the method of incubation or buried bag. Under incubation, two treatments' mineralized velocity reached the maximum at first month (31.67, 38.75 mg x kg(-1) x month(-1), respectively), and their cumulative mineralized rate and mineralized velocity at six months were 7.94%, 13.26 mg x kg(-1) x month(-1) and 9.24%, 17.99 mg x kg(-1) x month(-1), respectively. Under buried bag, the mineralized velocity of five treatments all reached the maximum at first year (55.67, 55.65, 49.60, 19.71, 22.52 mg x kg(-1) month(-1), respectively), and the cumulative mineralized rate and mineralized velocity of maize root and wheat root treatments at three years both were approximately 50% and 35 mg x kg(-1) x month(-1), which were higher than those under soybean root andgrass root treatments. From two methods of studies on the mineralization process of organic P, it could be seen that the original content of organic P influenced its mineralized rate and mineralized velocity: the higher of the original content of organic P, the higher of its mineralized rate and mineralized velocity.

China↗

[Distribution of C and N in different particle fractions of meadow brown soil in lower reach of Liaohe River Plain].

The study of meadow brown soil with different reclamation history in the lower reach of Liaohe River Plain showed that in 0 approximately 20 and 20 approximately 40 cm soil layers, <0.002 mm fraction had the highest content of organic carbon, followed by < 0.02 and < 0.2 mm fractions. The distribution pattern of total nitrogen was similar to that of organic carbon. There was no obvious correlation between the distribution of organic carbon and total nitrogen in different soil particle fractions and the history of reclamation, but the correlation between organic carbon and total nitrogen in different soil particle fractions was highly significant, with the correlation coefficients 0.74, 0.94 and 0.91 in fractions< 0.2, < 0.02 and < 0.002 mm, respectively.

Carbon↗

Characterization of the bovine neurofilament NF-M protein and cDNA sequence, and identification of in vitro and in vivo calpain cleavage sites.

Neurofilaments are the major components of the neuronal cytoskeleton, and accumulations of these proteins are associated with several important human diseases. Here we report the cloning and sequencing of bovine NF-M, the first NF-M cloned from a large domestic mammal. The bovine sequence proves to be generally more similar to that of human NF-M than the previously described mammalian sequences, suggesting that bovine neurofilaments are a useful model for biochemical studies of application to humans. However, we noted some unusual features within the 16 lys-ser-pro (KSP2) type phosphopeptide repeats and also note that the number of these repeats correlates well with the size of animal. We also characterized two in vitro calpain cleavage sites by direct peptide sequencing, finding that both are located in the glutamic acid rich E segment. Finally, we show biochemically that the more abundant and stable of these calpain fragments can also be detected in vivo.

Amino Acid Sequence↗