Response of needle photosynthetic and anatomical characteristics of naturally regenerated Pinus koraiensis seedlings to different canopy densities

We took 5-year-old Pinus koraiensis seedlings under natural secondary forests with canopy densities of 0.2-0.3, 0.4-0.6, and 0.7-0.9 at Laoshan Plantation Experimental Station in Maoershan Experimental Forest Farm of Northeast Forestry University as monitor object, and P. koraiensis seedlings under full-light environment as control (CK), to investigate the photosynthetic characteristics and the anatomical structure of P. koraiensis needles in response to the changes of canopy densities. The results showed that the height and diameter of P. koraiensis seedlings tended to decrease while specific leaf area increased with the increases of canopy densities. The total biomass of P. koraiensis seedlings under different canopy densities ranked in an order of 0.4-0.6＞CK＞0.7-0.9＞0.2-0.3. Photosynthetically active radiation (PAR) was significantly and positively correlated with leaf biomass, stem biomass, and root biomass. The net photosynthetic rate, transpiration rate, and intercellular CO2 concentration of P. koraiensis seedlings showed a decreasing trend with the increases of canopy densities, while the stomatal conductance showed an increasing trend. Net photosynthetic rate and chlorophyll a/b showed a significant positive correlation with PAR. Stomatal density showed a gradual decreasing trend with the increases of canopy densities, and the needle cross-sectional area, mesophyll tissue area, xylem area, and phloem area of P. koraiensis seedlings under canopy density 0.4-0.6 were significantly higher than those in other treatments. P. koraiensis seedlings with stronger photosynthetic abilities and higher needle anatomy parameters under canopy density 0.4-0.6, and were able to maintain strong competitiveness in this habitat. Those results indicated that 5-year-old P. koraiensis seedlings need certain shading environment.

[Feasibility on the diagnosis of non-calcified plaque based on radiomics of pericoronary adipose tissue on plain CT scan image]

Objective: To investigate the diagnostic value of radiomics model based on plain CT scan of peripheral coronary artery adipose tissue for non-calcified plaque. Methods: The image data of 461 patients undergoing coronary CT angiography (CCTA) in the Department of Radiology of the First Affiliated Hospital of Suzhou University from August 1,2019 to July 31,2020 were retrospectively analyzed. Two hundred and six cases (355 branches) with non-calcified plaques, and 255 cases (510 branches) with no coronary artery disease were detected by CCTA. The regions of interest (ROI) of the pericoronary adipose tissue were segmented on the plain CT scan images (coronary calcification score (CCS) sequence). The coronary ROI was determined by selecting the coronary artery with a length of 40 mm and starting at 10 mm from the opening of the coronary artery, and the pericoronary adipose ROI was generated automatically. The pericoronary fat attenuation index (FAI) was then performed, and the radiomics features were extracted. The 865 coronary arteries were divided into the training group (n=606) and the testing group (n=259) at a ratio of 7∶3, and the radiomics model was carried out. The receiver operating characteristic (ROC) analysis was used to assess the FAI value and the diagnostic efficacy of the radiomics model for non-calcified plaque. Results: A total of 1 692 features were extracted from images of pericoronary adipose based on plain scan. All features were screened by using max-relevance and min-redundancy (mRMR) and least absolute shrinkage and selection operator (LASSO), and 14 features were selected for the establishment of the radiomics model. The accuracy, sensitivity, specificity and area under the curve (AUC) of the model in distinguishing patients with non-calcified plaque and those without coronary stenosis in the testing group were 70.3%, 63.2%, 75.2% and 0.75, respectively. Conclusion: The radiomics model based on plain CT scan of the pericoronary adipose tissue had good diagnostic efficacy for non-calcified plaque.

[Practice guideline for patients with osteoporosis]

In recent years, osteoporosis (OP) has become one of the main diseases affecting the health of middle-aged and elderly people in China, and the prevalence of OP has increased significantly. The clinical diagnosis and treatment guidelines for this disease are also constantly updated. The overall principles speciallyemphasise that doctors and patients need to work together to negotiate the details of the diagnosis and treatment guidelines, in order to improve the OP clinical diagnosis and treatment rate. Therefore, patients' knowledge of the disease, understanding of clinical guidelines, and cooperation with doctors to implement diagnosis and treatment plans are very important. In this study, from the most concerned issues of the patients, we established the OP patient practice guideline working group. 14 recommendations, as the OP patient practice guidelines, are proposed in accordance with the relevant principles of the "World Health Organization guidelines development manual" and the international normative process.

[The influence of patellofemoral joint degeneration on outcome of Oxford medial unicompartmental knee arthroplasty]

Objective: To explore the influence of lateral patellofemoral joint degeneration on the treatment of anteromedial osteoarthritis of knee joint by Oxford medial unicompartmental knee arthroplasty. Methods: The clinical data of 73 patients (73 knees) with knee osteoarthritis underwent unicompartmental knee arthroplasty at Department of Orthopaedic Surgery, Xuanwu Hospital, Capital Medical University from March 2016 to December 2017 were analysed respectively.There were 18 males and 55 females, aged (68.6±7.5) years(range: 53 to 89 years).The lateral patellofemoral joints of patients were evaluated by Ahlback grading system. Patients with Ahlback 0 andⅠ were in the non degenerative group (37 cases), and those with Ahlback Ⅱ and above were in the degenerative group (36 cases). Hospital for special surgery knee score(HSS) and the Western Ontario and McMaster Universities(WOMAC) osteoarthritis index, as well as the condition of kneeling, sit to stand movement, up stair and down stair were recorded. The data before and after operation were compared by paired sample t test, and the data between groups were compared by independent sample t test. χ(2) test was used for counting data. Pearson correlation analysis was used to compare the correlation between ahlback score, HSS and WOMAC osteoarthritis index. Results: The follow-up time was (35.1±6.6) months (range: 25 to 47 months).The knee function of the patients improved significantly after operation.The HSS score increased from 57.7±11.8 preoperative to 81.8±7.8 postoperative (t=16.64, P=0.00) and WOMAC osteoarthritis index decreased from 48.9±13.4 preoperative to 15.6±8.8 postoperative (t=20.48, P=0.00). There was no statistical difference in the change of HSS between the degenerative group and the non-degenerative group before and after surgery(27.5±12.2 vs. 22.5±12.3, t=-1.65, P=0.10) as well as the change of WOMAC osteoarthritis index(31.8±14.0 vs. 36.4±13.7, t=-1.35, P=0.18), but the lateral patellofemoral joint degeneration was related to inability to complete squats (χ(2)=5.17, P=0.04) and sitting up (χ(2)=7.22, P=0.01). Conclusion: The degeneration of lateral patellofemoral joint has no effect on the early functional recovery of patients with anteromedial knee osteoarthritis after Oxford medial unicompartmental knee arthroplasty.

[Effects of girdling and defoliation on the growth of female cones and branches and nutrient content in different tissues and organs of Pinus koraiensis.]

To explore the nutrient source and supply-demand relationship of the female cone deve-lopment and new shoot growth of Pinus koraiensis, reproductive mother branches were experimentally girdled, defoliated, and under the combination of both treatments. The effects of different treatments on the female cones development, branch growth and the content of carbohydrate (NSC), nitrogen (N) and phosphorus (P) in different tissues and organs were measured. The results showed that girdling significantly affected female cone development, new shoot growth, and the contents of NSC, N and P in different tissues and organs, while defoliation treatment had limited effect. The NSC content in the mother branch xylem and phloem after girdling were significantly lower than that of the control (CK, ungirdling+0% defoliation), and decreased significantly with the increases of the degree of defoliation. The NSC content in mother branch xylem and phloem of girdling+100% defoliation was 59.0% and 64.8% lower than that of CK, respectively. The deficiency of NSC resulted in the death of mother branches and new shoots and the abortion of female cone. Under girdling treatment, the contents of N and P in xylem and phloem of mother branches of 0%, 50% and 100% defoliation treatment were significantly higher than that of CK. The contents of N and P in xylem of mother branches were 17.3%, 18.2% and 24.3% and 17.9%, 7.1% and 3.6% higher than those of CK, respectively. The contents of N and P in phloem of mother branches was 39.3%, 35.2% and 48.9% and 31.0%, 28.2% and 14.8% higher than those of CK, respectively. The female cone development and new shoot growth of P. koraiensis consumed a large amount of NSC, N and P. The carbohydrates and mineral nutrients manufactured or stored in the mother branches could not meet the needs of female cone development and new shoot growth, and thus they need to be imported from other tissues.

A long noncoding RNA MAP3K1-2 promotes proliferation and invasion in gastric cancer

Background

Long noncoding RNAs (lncRNAs) have been implicated in several human cancers. The expression profile and underlying mechanism of the lncRNA MAP3K1-2 in gastric cancer (GC) are poorly understood.

Methods

Sixty-one patients with GC were recruited from Shanghai Baoshan Luo Dian Hospital (Shanghai, China). Tumor tissues and paired normal tissues (5 cm adjacent to the tumor) were obtained. Expression of lncRNA MAP3K1-2 in GC cell lines was examined using quantitative real-time polymerase chain reaction. Protein expression was detected using Western blot. Cell cycle analysis was assessed using flow cytometry. Cell proliferation was assessed using soft agar assays, and cell invasion was assessed using Transwell assays.

Results

The expression level of lncRNA MAP3K1-2 was upregulated in GC cells and markedly higher in poorly differentiated cell lines. Silencing treatment of lncRNA MAP3K1-2 significantly inhibited cell proliferation and invasion in GC. In addition, knockdown of lncRNA MAP3K1-2 significantly inhibited the function of important genes in the MAPK signaling pathway. Higher expression of lncRNA MAP3K1-2 was often associated with poorer prognosis in patients with GC.

Conclusions

lncRNA MAP3K1-2 is a critical effector in GC tumorigenesis and progression, representing novel therapeutic targets. High lncRNA MAP3K1-2 expression may serve as a novel independent prognostic marker for predicting the outcome of GC.

Influence of biochar and nitrogen on fine root morphology, physiology, and chemistry of Acer mono

Fine roots play an important role in the overall functions of individual plants. Previous studies showed that fertilization and available soil resources have a notably profound effect on fine root, but there is lack of study centered on how fine root morphology, physiology, and chemistry respond to biochar with N additions. Different levels of biochar (0, 10, 15, and 20 g) and N (0, 2, 4 and 6 g) were applied to Acer mono seedling plants in a field nursery. The root system morphology and root chemistry and physiology were evaluated in line with root length, root diameter, SRL, N and N: C and root respiration. Biochar and N significantly affected root morphology, chemistry and root respiration. Morphological, chemical and physiological parameters were found to be at their maximum with 20 g biochar and 6 g N; however, no significant effect was noted on fourth- and fifth-order roots. Furthermore, a significant increase in root respiration was recognized with the increase in root tissue N concentration and the negative relationship of root respiration with higher branch order. Thus, overall, study parameters indicate that biochar and nitrogen positively influence the Acer mono fine root, and therefore should be used to improve fine root health.

[Analgesic effects of ionotropic glutamate receptor antagonists MK-801 and NBQX on collagen-induced arthritis rats]

OBJECTIVE

The ionotropic glutamate receptorantagonists include two types: MK-801, antagonist of N-methyl-D-asparticacid (NMDA) receptor, and NBQX, antagonist of non-NMDA receptor.The above-mentioned ionotropic antagonists can block the glutamate and its corresponding receptor binding to produce analgesic effect. The objective of this research was to study two antagonists in analgesic effect on rat behavior,as well as to investigate the down-regulation and up-regulation of cyclooxygenase-2 (COX-2) and Janus-activated kinase (Jak3) in collagen-induced arthritis (CIA) rat serum and tissue fluid after the application of these antagonists, that is, the effect on molecular biology.

METHODS

This study used the ionotropic glutamate receptors as the target and established CIA rat model. Vivo studies were used to observe changes in behavior and molecular biology of the CIA rat.Behavioral assessment includedmechanical allodynia and joint swelling in the CIA rat,where themechanical allodynia was measured using the paw-withdrawal threshold (PWT) with VonFrey filaments according to the "Up-Down" method,and the drainage volume was used to assess joint swelling. Then the blood samples taken from the heart of the rat and the tissue homogenate were collected to detect the down-regulation and up-regulation of COX-2 and Jak3 in the serum and tissue fluid after the antagonists wereused.

RESULTS

Using MK-801, NBQX alone or using the combination of these two antagonists,these three methods all could alleviate pain(P<0.01).The analgesic effect lasted more than 24 h.Both antagonists reached the peak of analgesia at the end of 4 hours post-injection. NBQX had stronger analgesic effect than MK-801 (P<0.05).Whether alone or combined use of these two antagonists,could not change the CIA rats' swelling of the joint (P>0.05). MK-801 could decrease the expression of COX-2 (P<0.01).At the same time, NBQX did not have this effect (P>0.05). Using MK-801, NBQX alone or combination of these two antagonists could not affect the increased expression of Jak3 caused by the CIA (P>0.05).

CONCLUSION

MK-801 and NBQX could both alleviate pain, NBQX was much better than MK-801. Neither MK-801 nor NBQX had the effect on the swelling of the joint. NMDA receptor and COX-2 inflammatory pathways had certain interactions. For Jak3, it could not be found to have cross-function with ionotropic glutamate signaling pathways by this experiment.

[Analysis of early failure of the PHILOS in proximal humerus fractures]

OBJECTIVE

To analyze the reasons of early failure of the PHILOS in proximal humerus fractures.

METHODS

From Nov. 2010 to Nov. 2014, there were 117 patients with humerus fractures treated with PHILOS locking plate in Department of Orthopaedics, Xuanwu Hospital. All of the patients were treated with the plate by open reduction internal fixation, and we analyzed these cases retrospectively. After the operation, we removed the drainage tube within 48 h, and the patients were allowed to do the passive motion 3 days after the surgery if the X-Ray showed the plate and screws were reliable. Eight cases failed within 4 weeks after the operation. We analyzed the reasons of the failure.

RESULTS

The rate of the failed cases was 6.83%(8/117). The average age was 72.4(66-82) years. In the 8 failed cases, 3 were on the right side, and the other 5 on the left side. As for the reason of the fractures, 2 cases were because of car accidents, and the other 6 because of daily life injury. According to the Neer classification, 3 cases were 2-part fractures, and the other 5 3-part fractures. Three cases were total failure, and the other 5 partial failure. All the 8 failed cases failed within 4 weeks after the operation, of which 1 was on the sixth day after surgery, the other 7 2 to 4 weeks after the surgery.The 3 totally failed cases were treated by removing the screws and plates, the other 5 by conservative methods. All of the cases were malunion at the end.

CONCLUSION

The early failure of the PHILOS locking plate in proximal humerus fractures is related to the bad reduction during the operation, the loss of medial cortex support, the limitation of screw length, the osteoporosis and the improper rehabilitation after operation.It is very important to do good preoperative plan for a surgeon. During the operation, we should try our best in the fracture reduction, use the appropriate plate and screws, and then pay attention to the rehabilitation after the operation. After all of this, the rate of failure may be decreased.

[Research of the effect of bone mineral density and fracture site of the vertebrae on low back pain in elderly patients with osteoporotic vertebral compression fractures]

OBJECTIVE

To investigate the effect of bone mineral density(BMD) and fracture site of the vertebrae on low back pain in elderly patients with osteoporotic vertebral compression fractures.

METHODS

From August 2011 to August 2013, a total of 107 senile patients with osteoporotic vertebral compression fractures underwent percutaneous vertebroplasty were followed up for more than 2 ( average 2.5) years in Department of orthopedics, Xuanwu Hospital, Capital Medical University. The incidence of low back pain after vertebroplasty were analyzed on visual analog scale (VAS), and the relationship between BMD, vertebral fracture site were investigated.

RESULTS

A total of 18 cases(16.8%)after vertebroplasty have significant low back pain. Along with BMD decreased [(-2.90±0.91) vs (-4.87±0.52)], the VAS of low back pain increasing, which showed statistical significance difference[(-3.12±0.91) vs (4.03±1.08), P<0.05]. The site of vertebral fracture was lower, the VAS was higher.

CONCLUSIONS

About 16.8% patients show obvious low back pain after vertebroplasty. BMD and Vertebral fracture site were important factors of low back pain in elderly patients with osteoporotic vertebral compression fractures after vertebroplasty.

[Analysis of early failure of the PHILOS in proximal humerus fractures]

OBJECTIVE

To analyze the reasons of early failure of the PHILOS in proximal humerus fractures.

METHODS

From Nov. 2010 to Nov. 2014, there were 117 patients with humerus fractures treated with PHILOS locking plate in Department of Orthopaedics, Xuanwu Hospital. All of the patients were treated with the plate by open reduction internal fixation, and we analyzed these cases retrospectively. After the operation, we removed the drainage tube within 48 h, and the patients were allowed to do the passive motion 3 days after the surgery if the X-Ray showed the plate and screws were reliable. Eight cases failed within 4 weeks after the operation. We analyzed the reasons of the failure.

RESULTS

The rate of the failed cases was 6.83%(8/117). The average age was 72.4(66-82) years. In the 8 failed cases, 3 were on the right side, and the other 5 on the left side. As for the reason of the fractures, 2 cases were because of car accidents, and the other 6 because of daily life injury. According to the Neer classification, 3 cases were 2-part fractures, and the other 5 3-part fractures. Three cases were total failure, and the other 5 partial failure. All the 8 failed cases failed within 4 weeks after the operation, of which 1 was on the sixth day after surgery, the other 7 2 to 4 weeks after the surgery.The 3 totally failed cases were treated by removing the screws and plates, the other 5 by conservative methods. All of the cases were malunion at the end.

CONCLUSION

The early failure of the PHILOS locking plate in proximal humerus fractures is related to the bad reduction during the operation, the loss of medial cortex support, the limitation of screw length, the osteoporosis and the improper rehabilitation after operation.It is very important to do good preoperative plan for a surgeon. During the operation, we should try our best in the fracture reduction, use the appropriate plate and screws, and then pay attention to the rehabilitation after the operation. After all of this, the rate of failure may be decreased.

Short-term and long-term effects of laparoscopic-assisted radical surgery in patients with advanced gastric cancer

AIM: To investigate the short-term and long-term efficacy of laparoscopic-assisted surgery in patients with gastric cancer.

METHODS: Two hundred and twelve patients who underwent routine D2 radical surgery at Pinggu Hospital from June 2007 to June 2009 were selected, including 110 receiving conventional open surgery (laparotomy group) and 102 receiving laparoscopic assisted surgery (laparoscopic group). Postoperative recovery was compared between the two groups. The complication rate, 5-year overall survival (OS), disease-free survival (DFS), locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), risk factors and postoperative complications were analyzed.

RESULTS: The blood loss was significantly less in the laparoscopic group (P < 0.05). The times to liquid food ingestion and anal exhaust and hospital stay were significantly shorter in the laparoscopic group (P < 0.05). The number of lymph nodes harvested and operative time showed no significant difference between the two groups (P > 0.05). The rate of postoperative complications was significantly lower in the laparoscopic group (17.65%) than in the laparotomy group (30.91%) (P < 0.05). Operative time, preoperative comorbidities, and laparoscopic assisted surgery were identified as independent risk factors for the occurrence of postoperative complications. Preoperative comorbidities and operative time were independent risk factors for laparoscopic assisted surgery. The 5-year OS, DFS, LRFS, and DMFS showed no significant differences between the two groups (P > 0.05).

CONCLUSION: Laparoscopic assisted surgery in management of advanced gastric cancer has similar therapeutic effects to open surgery, but is minimally invasive. Preoperative comorbidities and operative time are independent risk factors for the development of postoperative complications in laparoscopic treatment of advanced gastric cancer.

Effects of artesunate and ursolic acid on hyperlipidemia and its complications in rabbit

OBJECTIVE

To find the novel hypolipidemic agents, the effects of ursolic acid and artesunate on hyperlipidemia and its complications were determined in rabbit fed with Western-type diet.

METHODS AND RESULTS

New Zealand rabbits fed a Western-type diet developed a hyperlipidemia. Rabbits received ursolic acid (25mg/kg) or artesunate (25mg/kg) alone, or in combination (12.5+12.5mg/kg), to prevent hyperlipidemia. Ursolic acid or artesunate alone significantly decreased the plasma cholesterol and triglyceride in rabbits. Furthermore, they both attenuated liver steatosis and reduced the area of aortic root lesions. The combination of ursolic acid and artesunate was more potent than either agent alone, which indicates a strong synergistic effect.

CONCLUSION

The hypolipidemic effect of artesunate is firstly reported. Its combination with ursolic acid might have the potential to further develop for the treatment of atherosclerosis.

Methylenetetrahydrofolate reductase genotypes and haplotypes associated with susceptibility to colorectal cancer in an eastern Chinese Han population

Methylenetetrahydrofolate reductase (MTHFR) plays an important role in folate metabolism and is involved in DNA synthesis, DNA repair and DNA methylation. The two common functional polymorphisms of MTHFR, C677T and A1298C have been associated with several diseases, including cancer. We made a case-control study to analyze a possible association of MTHFR gene polymorphisms C677T and A1298C with risk for colorectal cancer in an eastern Chinese Han population of 137 patients with a confirmed histopathological diagnosis of CRC and 145 age- and gender-matched controls with no history of cancer. DNA was isolated from peripheral blood samples and the genotypes were determined by PCR-RFLP. The concentrations of folate in plasma were measured by chemiluminescence immunoassay. The MTHFR 677TT genotype had a protective effect against colorectal cancer, with an odds ratio (OR) = 0.467 (95% confidence interval (CI) = 0.225-0.966). The 1298CC genotype was significantly correlated with a reduced risk of colorectal cancer (OR = 0.192; 95%CI = 0.040-0.916). Compared with the MTHFR 677CC and MTHFR 1298 AA genotypes, for individuals who carried both MTHFR 677CC and 1298CC genotypes, the OR of colorectal cancer was 0.103 (95%CI = 0.012-0.900); among individuals who carried both MTHFR 677TT and 1298AC genotypes, the OR for risk of colorectal cancer was 0.169 (95%CI = 0.044-0.654). MTHFR 677TT+CT genotypes had a significantly lower plasma folate concentration than those with the MTHFR 677CC genotype. MTHFR 1298AC+CC genotypes had a lower plasma folate concentration than those with the MTHFR 1298AA genotype (P < 0.05). In conclusion, subjects with the MTHFR 677TT and MTHFR 1298CC genotypes appeared to have a significantly lower risk for colorectal cancer. MTHFR haplotypes 677CC/1298CC and 677TT/1298AC were less common in cases than in controls. These haplotypes, when compared to the most common haplotype 677CC/1298AA, were associated with a decreased risk for colorectal cancer. We conclude that plasma folate level is influenced by MTHFR genotypes.

[Effect of opening degree regulation on diameter and height increment and aboveground biomass of Korean pine trees planted under secondary forest]

Taking mixed forest of artifical Pinus koraiensis and natural broad-leaved trees as test material, among which the P. koraiensis was 15 (stage I) and 22 (stage II) years old respectively, and was in the same succession layer, the height and diameter increment during 4 years experimental period and the aboveground biomass (AGB) at the 4th experimental year for P. koraiensis were measured in the opening degree (K = 1.0, 1.5, 2.0) regulation experiment. The periodic increment of basal diameter (BD)/diameter at breast height (DBH), tree height and AGB of P. koraiensis trees were highest in the opening degree K = 1.0 treatment. The opening degree K = 1.5 and K = 2.0 treatments promoted the annual increment of P. koraiensis, with the effect increased along with the experimental period elongation and approached or exceeded that of K = 1.0 treatment. The stem biomass proportion of P. koraiensis trees was significantly higher in K = 1.0 treatment than that in the other treatments and the control in stage I, but no significant difference among treatments was found in stage II. The ratio of branch to needle biomass in all opening degree treatments was also significantly higher than that in control in stage I, but no significant difference in stage II. The proportion and distribution of needles in different ages differed in the two stages. It was concluded that opening degrees of 1.0-2.0 were all suitable for the growth of P. koraiensis of 15-22 years old trees planted under secondary forest.

[Natural regeneration characteristics of Sorbus pohuashanensis in forest region of eastern Northeast China]

Sorbus pohuashanensis is an important non-timber tree species in Northeast China. Aimed to study the natural regeneration characteristics of this tree species and related affecting factors, representative S. pohuashanensis forests in the forest region of eastern Northeast China were investigated by line sampling method. In this forest region, S. pohuashanensis was regenerated by seed propagation, stump sprouting, and root sprouting. In intact or poor habitat natural forests, the proportions of the S. pohuashanensis seedlings established by each of the three regeneration methods occupied roughly a third, with no significant difference (P > 0.05) among them; while in secondary forests, the frequency of stump sprouts (16.5%) was lower than that in natural forests. Even so, the combination of stump sprouting and root sprouting could likely maintain a stable local population. Root sprouting could make the seedlings spread more than 50 cm away from the stump. The transfer rate from diameter class II (1.0-2.9 cm) to diameter class III (3.0-4.9 cm) was 25.6% in secondary forests, 45.3% in poor habitat natural forests, and 15.9% in intact natural forests, suggesting that the lower transfer rate was the key limiting factor for S. pohuashanensis natural regeneration.

[Composition diversity of the multifunctional bacterium community NSC-7]

The NSC-7 microbial community could decompose cellulose and lindan with high efficiency. In order to determine the bacterial composition of the community, 11 isolate strains were detected by plate isolation, while a community reset by the 11 isolate strains lost the capacity of degrading cellulose. The capacity of degrading of the filter paper in double deck plate and monolayer plate were determined, only the filter paper in double deck plate were degraded, that means the main or key microbe are anaerobic. The denaturing gradient gel electrophoresis (DGGE) and construction of 16S rDNA clone library were used to identify the composition diversity of NSC-7 community. 195 clones and 25 strains were detected in clone library, and about 60% closest relative among them was known the detailed information which were belonged to Clostridium, Petrobacter, Bacteria, Paenibacillus, Proteobacterium. Furthermore, there were 40% closest relative belonged to uncultured bacterium clone.

Nuclear DNA microsatellites reveal genetic variation but a lack of phylogeographical structure in an endangered species, Fraxinus mandshurica, across North-east China

BACKGROUND AND AIMS

The widely accepted paradigm that the modern genetic structure of plant species in the northern hemisphere has been largely determined by recolonization from refugia after the last glacial maximum fails to explain the presence of cold-tolerant species at intermediate latitudes. Another generally accepted paradigm is that mountain ridges act as important barriers causing genetic isolation of species, but this too has been challenged in recent studies. The aims of the work reported here were to determine the genetic diversity and distribution patterns of extant natural populations of an endangered cool temperate species, Faxinus mandshurica, and to examine whether these two paradigms are appropriate when applied to this species over a wide geographical scale.

METHODS

1435 adult individuals were sampled from 30 natural populations across the main and central range of the species, covering major mountain ranges across North-east China (NEC). Genetic variation was estimated based on nine polymorphic nuclear microsatellite loci. Phylogeographical analyses were employed using various approaches, including Bayesian clustering, spatial analysis of molecular variance, Monmonier's algorithm, neighbor-joining trees, principal co-ordinate analysis and isolation by distance.

KEY RESULTS

Genetic diversity within populations was relatively high, and no significant recent bottlenecks were detected in any of the populations. A significant negative correlation between intra-population genetic diversity and latitude was identified. In contrast, genetic differentiation among all the populations examined was extremely low and no clear geographic genetic structure was identified, with the exception of one distinct population.

CONCLUSIONS

The modern genetic structure in this species can be explained by extensive gene flow, an absence of mountains acting as barriers, and the presence of a wide refuge across NEC rather than multiple small refugia. Intra-population genetic variation along latitudes is probably associated with the systematically northward shifts of forest biomes in eastern China during the mid-Holocene. To determine important genetic patterns and identify resources for conservation, however, it will be necessary to examine differentially inherited genetic markers exposed to selection pressures (e.g. chloroplast DNA) and to investigate different generations.

[Review on molecular regulation of in vitro shoot regeneration of plants]

In vitro shoot regeneration is a developmental process that multiple genes and their interactions are involved in. Initiation of somatic cells stimulated by cytokinin, division of the initiated somatic cells and succeeding shoot meristem development are three key steps in the process. Therefore, exploration of gene expression and their interactions involved in these steps will shed light on our understanding of the molecular mechanism for regulation of plant in vitro shoot regeneration. Here we reviewed the research results of molecular regulation process involved in these steps.

Non-peptide corticotropin-releasing hormone antagonists: syntheses and structure-activity relationships of 2-anilinopyrimidines and -triazines

Screening of our chemical library using a rat corticotropin-releasing hormone (CRH) receptor assay led to the discovery that 2-anilinopyrimidine 15-1 weakly displaced [125I]-0-Tyr-oCRH from rat frontal cortex homogenates when compared to the known peptide antagonist alpha-helical CRH(9-41) (Ki = 5700 nM vs 1 nM). Furthermore, 15-1 weakly inhibited CRH-stimulated adenylate cyclase activity in the same tissue, but it was less potent than alpha-helical CRH(9-41) (IC50 = 20 000 nM vs 250 nM). Systematic structure-activity relationship studies, using the cloned human CRH1 receptor assay, defined the pharmacophore for optimal binding to hCRH1 receptors. Several high-affinity 2-anilinopyrimidines and -triazines were discovered, some of which had superior pharmacokinetic profiles in the rat. This paper describes the structure-activity studies which improved hCRH1 receptor binding affinity and pharmacokinetic parameters in the rat. Compound 28-17 (mean hCRH1 Ki = 32 nM) had a significantly improved pharmacokinetic profile in the rat (19% oral bioavailability at 30 mg/kg) as well as in the dog (20% oral bioavailability at 5 mg/kg) relative to the early lead structures.

Synthesis, corticotropin-releasing factor receptor binding affinity, and pharmacokinetic properties of triazolo-, imidazo-, and pyrrolopyrimidines and -pyridines

The synthesis and CRF receptor binding affinities of several new series of N-aryltriazolo- and -imidazopyrimidines and -pyridines are described. These cyclized systems were prepared from appropriately substituted diaminopyrimidines or -pyridines by nitrous acid, orthoester, or acyl halide treatment. Variations of amino (ether) pendants and aromatic substituents have defined the structure-activity relationships of these series and resulted in the identification of a variety of high-affinity agents (Ki's < 10 nM). On the basis of this property and lipophilicity differences, six of these compounds (4d,i,n,x, 8k, 9a) were initially chosen for rat pharmacokinetic (PK) studies. Good oral bioavailability, high plasma levels, and duration of four of these compounds (4d,i,n,x) prompted further PK studies in the dog following both iv and oral routes of administration. Results from this work indicated 4i,x had properties we believe necessary for a potential therapeutic agent, and 4i1 has been selected for further pharmacological studies that will be reported in due course.