Characterization of inflammatory factor-induced changes in mesenchymal stem cell exosomes and sequencing analysis of exosomal microRNAs.

BACKGROUND: Treatments utilizing stems cells often require stem cells to be exposed to inflammatory environments, but the effects of such environments are unknown. AIM: To examine the effects of inflammatory cytokines on the morphology and quantity of mesenchymal stem cell exosomes (MSCs-exo) as well as the differential expression of microRNAs (miRNAs) in the exosomes. METHODS: MSCs were isolated from human umbilical tissue by enzymatic digestion. Exosomes were then collected after a 48-h incubation period in a serum-free medium with one of the following the inflammatory cytokines: None (control), vascular cell adhesion molecule-1 (VCAM-1), tumor necrosis factor (TNF) α, and interleukin (IL) 6. The morphology and quantity of each group of MSC exosomes were observed and measured. The miRNAs in MSCs-exo were sequenced. We compared the sequenced data with the miRBase and other non-coding databases in order to detect differentially expressed miRNAs and explore their target genes and regulatory mechanisms. In vitro tube formation assays and Western blot were performed in endothelial cells which were used to assess the angiogenic potential of MSCs-exo after inflammatory cytokine stimulation. RESULTS: MSCs-exo were numerous, small, and regularly shaped in the VCAM-1 group. TNFα stimulated MSCs to secrete larger and irregular exosomes. IL6 led to a reduced quantity of MSCs-exo. Compared to the control group, the TNFα and IL6 groups had more downregulated differentially expressed miRNAs, particularly angiogenesis-related miRNAs. The angiogenic potential of MSCs-exo declined after IL6 stimulation. CONCLUSION: TNFα and IL6 may influence the expression of miRNAs that down-regulate the PI3K-AKT, MAPK, and VEGF signaling pathways; particularly, IL6 significantly down-regulates the PI3K-AKT signaling pathway. Overall, inflammatory cytokines may lead to changes in exosomal miRNAs that abnormally impact cellular components, molecular function, and biological processes.

Inhibitory Effect of Decitabine-inhibeting Methylation of SHP-1 Gene on Proliferation and Apoptosis of MDS Cell Line Skm-1 / 中国实验血液学杂志

OBJECTIVE@#To investigate the phenotype and molecular mechanism of DCA on MDS cell model, and to study the response of chemotherapeutic medicines to MDS cells through multiple dimensions, such as cell proliferation, invasion, migration and apoptosis, thus revealing the molecular mechanism of DCA treatment of MDS and its relationship with SHP-1 gene methylation.@*METHODS@#MTT assay was used to determine the survival rate of MDS cells after treated by different concentrations of DCA. The effect of DCA on the invasion and migration of MDS cells was detected by Transwell assay method. Apoplexin V-FITCPI was used to detect apoptosis, the MDS treatment on the mechanism of DCA was investigated by Western blot and Real-time PCR experiment.@*RESULTS@#According to the experiment, it was found that tumor proliferation could be inhibited when MDS skm-1 cells was treated by DCA, and the absorbance was lower and the inhibitory effect was more obvious in the 2.0, 5.0 μmol/L DCA group than in the 0.5 μmol/L DCA group and the negative control group. Compared with the control group, the number of MDS skm-1 cells crossing through the transwell upper chamber was significantly decreased after DCA application. After treated with 0.5, 2.0 and 5.0 μmol/L DCA, the apoptosis rate of MDS cells was 4.54%, 9.31% and 16.58% respectively, while the apoptosis rate of the control group was 3.20%, which shows the apoptosis rate increased significantly with the concentration of DCA. After treatment of MDS cell lines with different concentration of DCA, the methylation status of SHP-1 gene was decreased with the increase of drug concentration, the expression of SHP-1 was increased, the expression of STAT3 was decreased and the level of phosphorylation was decreased.@*CONCLUSION@#By analyzing the phenotypic response of DCA treatment on MDS cells, it was found that interfere with MDS can be performed by inhibiting proliferation, metastasis, and inducing apoptosis in a dose-dependent way. It revealed that the molecular mechanism by DCA treatment can improve the methylation of SHP-1 gene and inhibit the expression of p-STAT3.

Mechanism and Its Countermeasure of Hypomethylating Agent Resistance in Patients with Myelodysplastic Syndrome--Review / 中国实验血液学杂志

Hypomethylating agents(HMA) currently are widely used in the treatment of myelodysplastic syndromes (MDS), provide a significant improvement in the treatment of MDS. However, resistance to HMA is an almost universal phenomenon. This review was focused on immune effects related to DNA methylation, and to explore the mechanism underlying HMA resistance involved in immune checkpoint pathways. However, the optimal role of checkpoint blockade therapy (CBT) and immune checkpoint pathways remain in HMA failure questionable. The better understanding of immune checkpoint pathways in resistance of HMA offers a compelling rationale to introduce CBT in patients as a novel treatment option. CBT is an established strategy in solid tumors with potential as an adjunctive therapy in hematologic malignancies, therefore, may alter the treatment landscape in MDS. The suitability and effectiveness of combining HMA with CBT need to be confirmed by the results of ongoing clinical trials, so as to find novel strategies to improve outcome after failure of HMA.

Lymphocyte Count before First Consolidation Therapy Is A Predictor of Relapse free Survival in Acute Myeloid Leukemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of absolute lymphocyte count(ALC) before start of the first cycle of consolidation chemotherapy(CC) on the relapse free survival in the patients with acute myeloid leukemia(AML), so as to explore a simple and easy method for predicting AML relapse.</p><p><b>METHODS</b>The clinical data of 132 patients with newly diagnosed AML (all non-acute promyelotic leukemia) from 2011 to 2017 were analyzed retrospectively. The 132 AML patients were treated with standard induction chemotherapy (IC) and consolidation chemotherapy (CC). According to lymphocyte count of patients before start of the first cycle of CC, the AML patients were divided into 2 group: high lymphocyte count group (H-Lym≥1.2×10/L) and low lymphocyte count group (L-Lym<1.2×10/L). The differences in ralapse rate and relapse-free survival between 2 groups were analyzed.</p><p><b>RESULTS</b>Among 132 patients with AML, patients who could be valuated and were elicible for the study accounted for 65 (49.24%). The absolute leukocyte count, age, chromosome karyotypes before IC of patients did not show statistical difference between H-Lym group (40 cases) and L-Lym group (25 cases). Unvarvate analysis showed that the Low lymphocyte count and unfavorable chromosome karyotypes were poor prognostic factors for the relapse-free survival time, and there was significant difference between 2 groups (P<0.01). The relapse risk in patients of L-Lym group increased, the hazard ratio (HR)=3.01 (95% CI=1.55-4.98) (P<0.01). In multivariate analysis containing unfavorable prognostic karyotypes, this trend still existed (HR=2.52, 95% CI 1.28-9.98)(P<0.01).</p><p><b>CONCLUSION</b>The AML patients with high lymphocyte count before the first CC have more long relapse free survival time suggesting that the lymphocyte count before the first CC may be prognostic factor for relapse free survival of AML patients.</p>

Research Advances of Molecular Genetic Abnormality in Myelodysplastic Syndrome--Review / 中国实验血液学杂志

The myelodysplastic syndromes (MDS) are a heterogeneous group of clonal myeloid disorders characterized by ineffective hematopoiesis and increased risk of transformation to acute myelogenous leukemia (AML). The treatment of MDS is highly dependent on the reliability of the prognostic evaluation model. Current clinical prognostic scoring systems are comprised of morphology, pivotal clinical trials and cytogenetic findings. However, none of the available prognostic systems incorporates disease-related molecular abnormalities, such as somatic mutations. Cumulative evidence suggests that genomic data can also be used clinically to assist the diagnosis, prognosis, prediction of response to specific therapies, and the development of novel and accurate targeted therapies. Therefore, it is not possible to predict the response of patients to molecular targeted drugs, such as demethylation drugs. With the recent advance in whole- genome sequencing technologies, cumulative evidence suggests that genomic data can also be associated with the genesis, prognosis, prediction of response to specific therapies, and the development of novel accuvate targeted therapies, the issue of having some mechanism to dissect this heterogeneity and precision treatment is coming to the fore. However, there are still several hindrances to its clinical application. If these problems can be solved, molecular genetics will further provide a theoretical basis for the application of precision medicine in MDS.

Predicting Therapeutic Response by Lymphocyte Level at 28th Day after DAC Treatment in Patients with MDS / 中国实验血液学杂志

OBJECTIVE@#To investigate a reliable clinical indication for predicting the therapeutic response of decitabine therapy in the patients with myelodysplastic syndromes (MDS).@*METHODS@#The clinical efficacy of decitabine for 55 cases of MDS was analyzed retrospectively. According to the lymphocyte level at d28 after the first time treatment with decitabine, the patients were divided into high lymphocyte level group (H-Lym≥1.2×10/L) and low lymphocyte level group (L-Lym<1.2×10/L), and the overall response rate (ORR) and the progression-free survival (PFS) time in 2 groups were compared.@*RESULTS@#As compared with L-Lym group, the ORR and PFS time in H-Lym group were significantly enhanced ［(76.0% vs 50.0%) (P<0.05) and median time (15.7 months vs 8.5 months)(P<0.05), respectively］;the ratio of platelet level ≥100×10/L in H-Lym group was very significantly higher than that in L-Lym group (72.0% vs 20.0%)(P<0.01). Multivariat analysis showed that the risk of disease progression in L-Lym group was 4.45-fold of H-Lym group (95% CI:1.58-12.59)(P<0.05).@*CONCLUSION@#The patients with lymphocyte level ≥1.2×10/L at day 28 after the first time treatment with decitabine show the higher ORR and longer PFS time, therefore. the lymphocyte level at day 28 after first time treatment with decitabine can be used as an early clinical indicator for predecting the response to decitabine treatment.

The absolute value of lymphocyte counts and the response to decitabine treatment in patients with myelodysplastic syndrome / 解放军医学杂志

Objective To investigate the relations of absolute lymphocyte counts (ALC) to the therapeutic responses in patients with myelodysplastic syndrome (MDS) after the first course of decitabine (DAC) treatment.Methods Clinical data of 35 patients with MDS and MDS-derived secondary acute myeloid leukemia (AML) who were admitted in the Affiliated Hospital of Hebei University from Jan.2014 to Dec.2016 and treated with DAC were included in the present study.The patients were grouped into high lymphocyte group (H-Lym,ALC ≥ 1.2 × 109/L) and low lymphocyte group (L-Lym,ALC＜1.2 × 109/L) based on the ALC in days 28-35 after the first course of DAC treatment.The baseline data of both groups were compared with Pearson x2 analysis,while t test was used to analyze the changes of lymphocyte number before and after the first course of DAC treatment.Progressionfree survival (PFS) was estimated with Kaplan-Meier method,and the cumulative survival (CS) was compared between the two groups using log-rank test.Results Of the 35 patients,15 were in H-Lym group and 20 in L-Lym group.No significant difference existed in the baseline lymphocyte levels between the two groups (P＞0.05).The statistically significant differences (P＜0.05) existed only in the patients of the two groups who were with the proportion of bone marrow blasts ≥ 10％.The ALC in H-Lym group were slightly higher after the first course of DAC treatment than that at the time of diagnosis,but with no statistically significant (P＞0.05).However,the ALC in L-Lym group were significantly lower after the first course of DAC treatment than that at the time of diagnosis (P＜0.05).Patients had higher overall response rate (ORR) in H-Lym group than in L-Lym group (80％ vs.40％,P＜0.05).The median PFS was 10 months in H-Lym group and 7.6 months in L-Lym group (P＜0.05).Univariate analysis showed that the low ALC was a poor prognostic factor for the progression ofMDS (P＜0.05).Conclusion Patients with ALC ≥ 1.2 × 109/L after the first course of DAC treatment will have better ORR and longer PFS.

[Karyotype analysis of three Lonicera species growth in Sichuan].

OBJECTIVE: To provide the genetic reference for development and application of Lonicera species growth in Sichuan. METHODS: Shoot apices cells from Lonicera japonica, Lonicera japonica var. chinensis and Lonicera similis (cultivars) were used to make the chromosomal preparation. Their karyotypes were analyzed and the relevant parameters of chromosomes were measured by improved chromosome preparation technique. RESULTS: The chromosome numbers of three Lonicera species were 2n = 2X = 18; their chromosome length was 30.747, 33.231 and 36.948 microm; Their karyotype formula was 2n = 2X = 18 = 2m + 7sm, 2n = 2X = 18 = 8m + 8sm + 2st and 2n = 2X = 18 = 8sm + 10m; Their As. k was 64.013%, 64.380% and 61.949%; And their karyotypes belonged to 2B, 2B and 2A type, respectively. CONCLUSION: These three Lonicera species can be of the germplasm resources for widely cultivating since they have high degree genetic evolution.

[Induction on callus culture and regeneration of Orostachyis fimbriatae].

OBJECTIVE: To explore the effects of different hormonal combinations on induction, proliferation and differentiation of Orostachyis fimbriatae callus culture. METHODS: Aseptic seedling leaves were used as explants,the different concentrations of IAA,NAA, 6-BA and KT on induction proliferation of callus were optimized by orthogonal test to explore the optimum medium for differentiation of callus by tissue culture techniques. RESULTS: The best medium for induction was MS + IAA 1.0 mg/L + NAA 0.5 mg/L + KT 1.0 mg/L, and the best hormonal combination for proliferation was MS + IAA 0.5 mg/L + 6-BA 0.5 mg/I. + KT 1.0 mg/L. The best medium for differentiation was MS + IAA 0.1 mg/L + KT 2.0 mg/L, and 1/2MS + IAA 0.2 mg/L was the optimum medium for rooting culture. CONCLUSION: The system of regeneration of Orostachyis fimbriatae is establishd by tissue culture techniques in this study.

Immunohistochemistry in the diagnosis of papillary lesions of the breast.

AIMS: Many immunohistochemical markers have been studied for differentiating papillary lesions. However, their differentiating power has not been evaluated comprehensively. Additionally, assessment of some markers will require the difficult task of identifying different cell types. In the current study, we aimed to devise a simple papillary panel which can aid in diagnosis irrespective of architectural pattern and cell type differentiation. METHODS AND RESULTS: Immunohistochemical analysis of papillary lesions using myoepithelial markers [p63 and smooth muscle actin (SMA)], high molecular weight cytokeratins (HMWCKs: CK5, CK5/6, CK14 and 34ßE12), hormone receptors (ER and PR) and neuroendocrine markers (chromogranin and synaptophysin) was performed. Among them, neuroendocrine markers showed high specificity but low sensitivity. HMWCK specificity was better than that for myoepithelial markers. Homogeneous staining pattern for hormonal receptors rather than their percentage positivity was more effective in identifying malignant lesions. Negative staining for two or more of HMWCKs, namely CK5/6, CK14 and 34ßE12, achieved the best overall specificity and sensitivity of 87.8% and 94.1%, respectively, irrespective of the architecture. Their discriminatory power was validated with an independent cohort of core needle biopsies. CONCLUSIONS: A marker panel with HMWCKs could be used in differentiating papillary lesions irrespective of architectural pattern or cell type differentiation.

Increased SOX2 expression in less differentiated breast carcinomas and their lymph node metastases.

AIMS: SOX2 is a key regulatory gene in embryonic stem cells. Although it has been implicated in cancer progression, its role in breast carcinoma is poorly understood. MATERIALS AND METHODS: Fifty-seven ductal carcinomas in situ (DCIS), 552 invasive breast carcinomas and 107 corresponding metastatic lymph nodes were evaluated immunohistochemically for the expression of SOX2. Its correlation with clinicopathological features, other biomarker profiles and patients' outcomes were analysed. RESULTS: SOX2 was detected in 19.0% (105 of 552) of invasive breast carcinomas and 12.3% (seven of 57) of DCIS. Expression correlated with larger tumour size (P = 0.005) and higher grade (P = 0.002). It was associated negatively with ER (P = 0.015) and PR (P = 0.046) expression, but positively with Ki67 index (P = 0.013). Interestingly, it was also associated with neuroendocrine marker expression (synpatophysin and chromogranin/synaptophysin, P = 0.048 and 0.028, respectively). Expression appeared to be independent from that of common stem cell markers, namely CD44, CD24 and aldehyde dehydrogenase 1 (ALDH1). Furthermore, a higher rate of expression was observed in metastatic lymph nodes than in the corresponding primary tumours (P = 0.034). High SOX2 expression was correlated with poor disease-free survival (log-rank=9.489, P = 0.012) and was an independent prognostic factor (HR=2.918, P = 0.015) in patients with high nodal stages. CONCLUSIONS: In summary, SOX2 expression was related to adverse breast carcinoma profile and poor outcome in selected patient groups.

Efects of Inhibiting miR-155 Expression on the Proliferation and Apoptosis of Leukemia THP-1 Cells / 中国实验血液学杂志

The aim of this study was to investigate the effects of miR-155 inhibitor transfection on the proliferation and apoptosis of THP-1 cells. The miR-155 inhibitor was transfected into THP-1 cells (THP-1I) by using X-treme GENE siRNA transfection reagent. Cells without transfection (THP-1C) and cells with negative transfection (THP-1IC) were used as controls. Quantitative real-time polymerase chain reaction (RT-PCR) was performed to detect the expression of miR-155 and relative expression of SHIP1 mRNA in the cells. Cell proliferation was assayed using CCK-8 method. Cell apoptosis were detected by flow cytometry. The expression of SHIP1, TAKT and pAKT in THP-1 cells were detected by Western blot. The results indicated that compared with THP-1C and THP-1IC, the expression of miR-155 in THP-1I cells was significantly reduced; miR-155 inhibition significantly increased apoptosis rate in THP-1 cells (P < 0.05) ; miR-155 inhibition in THP-1 cells caused no significant alteration in SHIP1 mRNA level but significantly increased its protein content, indicating some post-transcriptional modulations might exist underlying the modulation of miR-155 to SHIP1, the miR-155 caused significantly reduced protein level of pAKT (P < 0.05) without interfering TAKT protein content. It is concluded that the miR-155 inhibition may promote THP-1 cell apoptosis through increasing SHIP1 protein content and impairing its downstream PI3K/AKT signaling pathway. This study suggests that miR-155 inhibition may be a promising therapy strategy for treating acute myeloid leukemia (AML).

Expression of mammaglobin and gross cystic disease fluid protein-15 in breast carcinomas.

Immunohistochemical analysis of gross cystic disease fluid protein-15 (GCDFP-15) and mammaglobin (MGB) is frequently used in routine practice for assessment of metastases or regional recurrences of breast origin. Breast cancer is highly heterogeneous. Expression of these 2 markers in various breast cancer subtypes has not been well studied. In addition, the usefulness of these two markers in combination in detecting breast origin has not been explored. In this study, a large cohort of breast cancers was evaluated for GCDFP-15 and MGB expression, both individually and combined. Their expression was correlated with cancer subtypes, other biomarkers and clinicopathologic parameters. A higher sensitivity for MGB (42.3%) than GCDFP-15 (31.6%) in detecting cancers of breast origin was observed. Combining both increased the sensitivity further, both for primary tumor (53.0%) and for nodal metastases (69.0%). GCDFP-15 was associated significantly with a breast cancer profile of good prognosis tumors, including lower grade (P < .001), pN (P = .029) and Ki-67 (P < .001) as well as negative basal markers expression (P = .043, .009, and .049 for c-Kit, CK5/6 and epidermal growth factor receptor, respectively) and, thus, may not be sensitive for detection of poor prognosis tumors. MGB has the highest expression in HER2-overexpressing cancers (56.6%), and may be a potentially useful marker for this subtype. Nonetheless, both markers showed low expression in the basal like (BLBC) subtype (11.9% and 21.4% for GCDFP-15 and MGB respectively), therefore, the detection of BLBC remains problematic. Negative results need to be interpreted with caution, and correlation with other clinical findings may be required to exclude the possibility of metastatic BLBC.

[Callus induction and plant regeneration of Sambucus chinensis].

OBJECTIVE: To optimize the medium for callus and multiple shoot induction and cultural plantlets rooting of Sambucus chinensis, and to provide a basis for the development of the seedling of mass production and germplasm conservation. METHODS: The plantlet leaves, petioles, stems and shoot tips were used as explants for the study of influences of different explants and different hormones on callus and multiple shoot induction, and cultural plantlets rooting. RESULTS: The optimal medium for callus induction of leaves was MS +2, 4-D 1.5 mg/L; and optimum mediums for petiole were MS + NAA 0.2 mg/L + KT 1.0 mg/L and MS +2, 4-D 0. 2 mg/L + KT 1.0 mg/L, MS + NAA 0.2 mg/L + KT 3.0 mg/L + GA, 2.0 mg/L medium was best for multiple shoot induction. And the best medium for tissue culture rooting was 1/2 MS + NAA 0. 3 mg/L. On the optimized medium, the roots were well-developed and the plants were healthier. CONCLUSION: Both the leaves and petioles can be well induced to callus on suitable medium, the stems and shoot tips are the best materials for multiple shoot induction and plant regeneration.

Relationship between microRNA-155 and hematological malignancies / 中国实验血液学杂志

MicroRNA (miRNA) are small non-coding RNA that act at the post-transcriptional level, regulating protein expression by repressing translation mRNA target. They can be detected in plants, animal species and viruses, and are involved in numerous cellular processes. MicroRNA-155 (miR-155) which is a kind of microRNAs expressed in hematopoietic cells. Recent data indicate that MiR-155 plays a key role in the pathogenesis of hematological malignancies through regulating cell signal transduction pathways of cell proliferation, differentiation and apoptosis, acting predominantly as an oncomir. MiR-155 may be an important indicator to assess the diagnosis, treatment and prognosis of patients with hematological malignancies, including malignant lymphoma, acute myeloid leukemia, and myelodysplastic syndrome. It could be suggested that drugs such as antisense oligonucleotides able to down-regulate miR-155 expression would provide a novel, and possibly specific way to control the growth of a range of haematopoietic malignancies in conjunction with classical cytotoxic therapy. The purpose of this review is to summarize current findings on the role of miR-155 in hematopoietic malignancies and, moreover, to highlight their role as potential therapeutic tools.

Cancer stem cell markers are associated with adverse biomarker profiles and molecular subtypes of breast cancer.

Cumulative evidence has demonstrated the presence of cancer stem cells (CSC) in breast cancer and its putative role in cancer progression. Nonetheless, the clinical significance of CSC in breast cancer remains elusive. The underlying reasons could be due to the heterogeneity of breast cancer subtypes as well as different markers used to define breast CSC. In this study, three widely used markers (aldehyde dehydrogenase (ALDH)1+ and CD24-CD44+) were used to define two populations of CSC in a large cohort of breast cancers. The expressions of these markers were correlated with different clinicopathological features and the molecular subtypes. ALDH1+ breast cancers were associated with basal-like and HER2-overexpressing subtypes and the characteristics histologic features were related to these two subtypes. On the other hand, CD24-CD44+ breast cancers were associated positively with the presence of extensive in situ component, the absence of lymph node involvement, and basal markers, but negatively with HER2. CD24-CD44+ breast cancers were also positively associated with luminal B cancers. As the expression of CSC markers varied among different molecular subtypes and different clinicopathological features, it appeared that each CSC population could have distinct clinical values in different subgroups of breast cancers. For improved prognostication with CSC, combining the analysis of CSC markers would be required. Within the luminal cancers, CSC appeared to identify cancers with poor outcome. The presence of CSC populations was associated with ER-PR+ cancers and tumors expressing basal markers. Basal marker expression can complement with CSC for improved indicator for poor prognosis in luminal breast cancers. For the first time, the possible contribution of CSC to these aggressive luminal cancers was demonstrated. The association of basal features and CSC in luminal cancers also raised the possibility that luminal cancer cells may acquire basal phenotype and CSC properties together during their progression.

A single leaf of Camellia oleifera has two types of carbon assimilation pathway, C(3) and crassulacean acid metabolism.

The C(4) plants, whose first product of photosynthetic CO(2) fixation is a four-carbon acid, have evolved independently many times. Crassulacean acid metabolism (CAM) is a biological mechanism known to exhibit some C(4) characteristics such as the C(3) cycle during daylight and demonstrates the C(4) cycle at night. There are also various C(3)-CAM intermediates, whose CAM pathway can be induced by environmental changes. However, neither fungus-induced CAM nor Theaceae CAM have been reported previously. Here, we show that CAM could be generated by fungus infection in Camellia oleifera Abel. young leaves, even at a location of a single leaf where the upper part had been transformed into a succulent one, while the lower part remained unchanged. The early photosynthetic products of dark-grown C. oleifera succulent leaves were malate, whereas C. oleifera normal leaves and light-grown succulent leaves incorporated most of (14)C into the primary photosynthetic product 3-phosphoglycerate. Camellia oleifera succulent leaves have a lower absolute δ(13)C value, much lower photorespiration rates and lower transpiration rates during the day than those of C. oleifera normal leaves. Like a typical CAM plant, stomata of C. oleifera succulent leaves closed during the daylight, but opened at night, and therefore had a detectable CO(2) compensation point in darkness. Net photosynthetic rates (P(n)) fluctuated diurnally and similarly with stomatal aperture. No light intensity saturation could be defined for C. oleifera succulent leaves. C(4) key enzymes in C. oleifera succulent leaves were increased at both the transcriptional/translational levels as well as at the enzyme activity level.

[Effects of drought stress on leaf gas exchange and chlorophyll fluorescence of Salvia miltiorrhiza].

Taking the seedlings of Salvia miltiorrhiza cv. Sativa (SA) and S. miltiorrhiza cv. Silcestris (SI) as test materials, this paper studied the effects of drought stress on their leaf gas exchange and chlorophyll fluorescence parameters. After 15 days of drought stress, the net photosynthetic rate (P(n)) and the maximal photochemical efficiency of PS II (F(v)/F(m)) of SA were decreased by 66.42% and 10.98%, whereas those of SI were decreased by 29.32% and 5.47%, respectively, compared with the control, suggesting that drought stress had more obvious effects on the P(n) and F(v)/F(m) of SA than of SI. For SI, the reduction of P, under drought stress was mainly due to stomatal limitation; while for SA, it was mainly due to non-stomatal limitation. Drought led to a decrease of leaf stomatal conductance (G(s)), but induced the increase of water use efficiency (WUE), non-photochemical quenching coefficient (q(N)), and the ratio of photorespiration rate to net photosynthetic rate (P(r)/P(n)), resulting in the enhancement of drought resistance. The increment of WUE, q(N), and P(r)/P(n) was larger for SI than for SA, indicating that SI had a higher drought resistance capacity than SA.

[Studies on chemical constituents of Sambucus adnata].

OBJECTIVE: To study the chemical constituents of Sambucus adnata. METHOD: Compounds were isolated by silica gel chromatography. Their structures were elucidated by means of spectral analysis. RESULT: Five compounds were isolated and identified as: 1-(3-hydroxy4-methoxyphenyl)-1',2'-ethanediol (1), ursolic acid (2 ), 1-( 3,4,5 -trimethoxyphenyl) -1', 2'-ethanediol (3), lariciresinol (4), 5, 7, 3', 4'-tetramethoxyflavone-3-O-rhamnopyranosyl-(1 --> 6)-glucopyranoside(5). CONCLUSION: Compounds 1, 3, 4 and 5 were obtained from this plant for the first time.

A chlorophyll-less barley mutant "NYB" is insensitive to water stress.

"NYB" is a chlorophyll-less barley mutant, which grows relatively slow and unhealthily. The effects of water stress on photosystem II (PSII) of NYB and its wild type (WT) were investigated. Unexpected results indicated that the mutant was more resistant to water stress, because: PSII core proteins D1, D2 and LHCII declined more in WT than in NYB under water stress, and the corresponding psbA, psbD and cab mRNAs also decreased more dramatically in WT; CO2 assimilation, stomatal conductance, maximum efficiency of PSII photochemistry (Fv/Fm), efficiency of excitation energy capture by open PSII reaction centres (Fv'/Fm'), quantum yield of PSII electron transport (Phi(PSII)) and DCIP photoreduction in NYB were less sensitive to water stress than in WT, although the non-photochemical quenching coefficient (q(N)) and the photochemical quenching coefficient (q(P)) were almost the same in NYB and WT. Effective chlorophyll utilization and improved PSII protein formation in the mutant may be the reason for the enhanced stress resistance. Other possible mechanisms are also discussed.