Injection therapy promotes repair of unhealed internal opening after surgery for anal fistula in a rat model

AIM: To explore the mechanism by which injection therapy promotes the repair of unhealed internal opening after surgery for anal fistula in rats.

METHODS: A total of 80 SD rats were used to create unhealed internal opening models after surgery for anal fistula. The rats were then randomly divided into four groups (n = 20 for each group): A, B, C and D. Two days after successful modeling, group A was injected with gentamicin sulfate in the apical internal opening and the potential side wall of fistula; group B did not receive any further processing; group C received an injection of physiological saline; and group D underwent traditional incision and drainage and washing with normal saline. Some fistulas were taken to collect granulation tissue in the internal opening 24 h, 3, 7 and 14 d after treatment, and the contents of macrophages, fibroblasts and collagen Ⅰ in the tissue were measured by immunohistochemistry.

RESULTS: On the 3^rd and 7^th days after treatment, macrophage contents were significantly lower in the injection-therapy group than in the other three groups (38.7 ± 4.7 vs 30.2 ± 4.1, 30.8 ± 3.9, 32.1 ± 4.2, P < 0.05; 43.2 ± 5.1 vs 32.8 ± 4.8, 32.2 ± 4.3, 34.6 ± 5.2, P < 0.05), while the contents of fibroblasts (81.25 ± 7.72 vs 30.54 ± 6.21, 31.36 ± 5.78, 48.75 ± 6.45, P < 0.05; 143.53 ± 13.23 vs 89.63 ± 8.32, 87.46 ± 7.84, 115.57 ± 11.26, P < 0.05) and collagen Ⅰ were greater than those in the other three groups (123621.4 ± 23512.3 vs 2632.5 ± 1846.8, 76352.8 ± 18462.5, 96342.6 ± 19637.4, P < 0.05; 342753.9 ± 24317.7 vs 124356.8 ± 21475.6, 126789.3 ± 23124.8, 185783.4 ± 24315.6, P < 0.05). On the 14^th day after treatment, the contents of macrophages (11.2 ± 2.7 vs 18.8 ± 4.1, 19.1 ± 4.7, 14.2 ± 3.8, P < 0.05), fibroblasts (56.72 ± 5.81 vs 73.83 ± 6.58, 75.67 ± 7.14, 64.84 ± 6.73, P < 0.05), and collagen Ⅰ (52896.5 ± 12351.3 vs 113267.8 ± 20567.4, 119467.9 ± 21486.5, 82748.4 ± 18575.9, P < 0.05) were significantly lower in the injection-therapy group than in the other three groups.

CONCLUSION: Gentamycin injection therapy can promote the healing of unhealed internal opening following anal fistulectomy, prevent scars from forming and improve the quality of wound healing.

Catechins induced acute promyelocytic leukemia cell apoptosis and triggered PML-RARα oncoprotein degradation

Background

It has recently been reported that the extracts of green tea polyphenol have cancer preventive effects. In this study, we investigated the effect of the natural composition from green tea leaves Catechins on acute promyelocytic leukemia (APL).

Methods

In vitro, APL cell lines NB4, retinoic acid-resistant NB4-R1 and NB4-R2 were treated with different concentrations of Catechins. Cell viability and cell apoptosis were analyzed using MTT assay and flow cytometric assay, respectively. Expression of proteins related to apoptosis and PML-RARα oncoprotein were assessed by Western blot. In vivo anti-tumor activity of Catechins was examined in nude mice xenografted with NB4 cells and in situ cell apoptosis was detected by terminal deoxytransferase-catalyzed DNA nick-end labeling assay.

Results

Catechins at micromolar concentration levels significantly inhibited APL cell proliferation and induced cell apoptosis, in association with mitochondria damage, ROS production and caspase activation. The anti-apoptotic Bcl-2 family member Bcl-xL was down regulated, with pro-apoptotic member Bax remaining unchanged. Moreover, Catechins induced the degradation of PML-RARα oncoprotein. Catechins-mediated apoptotic effect was also observed in primary APL cells without affecting normal hematopoietic progenitor cells. In the murine xenograft model, Catechins remarkably inhibited tumor growth and induced in situ leukemic cell apoptosis.

Conclusions

Catechins might be a potential candidate for APL treatment by activating intrinsic apoptotic pathway and targeting PML-RARα oncoprotein.

[Response of mineralization of dissolved organic carbon to soil moisture in paddy and upland soils in hilly red soil region]

Typical paddy and upland soils were collected from a hilly subtropical red-soil region. 14C-labeled dissolved organic carbon (14C-DOC) was extracted from the paddy and upland soils incorporated with 14C-labeled straw after a 30-day (d) incubation period under simulated field conditions. A 100-d incubation experiment (25 degrees C) with the addition of 14C-DOC to paddy and upland soils was conducted to monitor the dynamics of 14C-DOC mineralization under different soil moisture conditions [45%, 60%, 75%, 90%, and 105% of the field water holding capacity (WHC)]. The results showed that after 100 days, 28.7%-61.4% of the labeled DOC in the two types of soils was mineralized to CO2. The mineralization rates of DOC in the paddy soils were significantly higher than in the upland soils under all soil moisture conditions, owing to the less complex composition of DOC in the paddy soils. The aerobic condition was beneficial for DOC mineralization in both soils, and the anaerobic condition was beneficial for DOC accumulation. The biodegradability and the proportion of the labile fraction of the added DOC increased with the increase of soil moisture (45% -90% WHC). Within 100 days, the labile DOC fraction accounted for 80.5%-91.1% (paddy soil) and 66.3%-72.4% (upland soil) of the cumulative mineralization of DOC, implying that the biodegradation rate of DOC was controlled by the percentage of labile DOC fraction.

Significance of combined detection of p53 and FHIT in cervical carcinoma diagnosis

PURPOSE

To explore the significance of combined detection of p53 genes and fragile histidine triad (FHIT) genes in cervical carcinoma.

MATERIALS AND METHODS

Specimens taken from 161 cases invasive carcinoma, 23 cases carcinoma in situ or cervical intraepithelial neoplasia III (CIN III), 74 cases CIN I - II, 25 cases normal cervical tissue, and 32 cases tumor-adjacent tissues were processed by immunohistochemistry to determine the expression of p53 and FHIT genes. The results of the combined detection were compared for clinical diagnostic value of cervical carcinoma diagnosis.

RESULTS

The p53 gene, FHIT gene and the two genes combined examination of cervical carcinoma diagnostic sensitivity were: 65.8% (121/184), 66.3% (122/184), 90.2% (166/184), respectively. There were no significant differences between the p53 gene and the FHIT gene detected (p > 0.05). Combined detection of the two gene were more sensitivity than single detection, the difference was significant (p < 0.001). Although diagnosis specificity had dropped somewhat, no significant statistical appeared (chi2 = 0.022, p > 0.05).

CONCLUSION

Combined detection of p53 genes and FHIT genes can increase the sensitivity diagnosis and specificity diagnosis for early cervical carcinoma and precancerous lesions has a positive meaning.

Normal evolution of pregnancy complicated by a giant placental chorioangioma

Placental chorioangioma is a benign vascular tumour of placental origin. Here The authors report a case of a pregnant patient who presented placental chorioangioma measuring 11 cm in the greatest diameter at 37 weeks at term and in labor.

[Research on chemical fingerprint chromatograms of Sinopodophyllum hexandrum]

OBJECTIVE

To study the HPLC fingerprint of Sinopodophylli Fructus, compare the major chemical differences in fruit of Sinopodophyllum hexandrum as well as the roots and rhizomas of S. hexandrum, and provide scientific evidence for clinical application and quality control.

METHOD

HPLC fingerprint method was used to analyze 12 fruits of S. hexandrum. A total of 20 common peaks were confirmed, and 12 peaks in the HPLC fingerprint were identified. Furthermore, similarity evaluation method and clustering analysis method were introduced to compare HPLC chromatograms, between fruits and underground parts.

RESULT

In this paper, quercetin-3-O-beta-D-glucopyranosid, kaempferol-3-O-beta-D-glucopyranoside, 8-prenylquercetin and 8-prenylquercetin 3-methyl ether were firstly reported in Sinopodophylli Fructus. Among the existing fingerprint research, a total of 11 peaks were identified for the first time, containing 9 flavonoids and 2 lignans. The chemical constituents differed significantly in different medicinal parts of S. hexandrum. Prenylflavonoid compounds were the main constituents of Sinopodophylli Fructus. However, podophyllotoxin, flavonoids with simple substituent groups and flavonoid glycosides were the major ingredients in the roots and rhizomas of S. hexandrum.

CONCLUSION

This method can be used for the quality control of Sinopodophylli Fructus and the roots and rhizomas of S. hexandrum. It has provided a reference for the pharmacodynamic differences of the two different parts.

Pregnancies in patients with chronic myeloid leukemia treated with tyrosine kinase inhibitor

We presented our experience in chronic myeloid leukemia (CML) patients who conceived children and/or became pregnant while receiving tyrosine kinase inhibitor (TKI). Among 7 male patients, 7 pregnancies resulted in the birth of 7 healthy babies. Among 18 female patients, 8 ended in elective abortion; 3 had spontaneous abortion, and 7 carried to term, resulting in the birth of 8 healthy babies. All children have normal growth and development. All patients remain in TKI therapy and in good response. It is suggested that female patients are advised to practice adequate contraception. No special precautions apply for male patients receiving TKI.

Activation of the PI3K/AKT/mTOR pathway in diffuse large B cell lymphoma: clinical significance and inhibitory effect of rituximab

Diffuse large B cell lymphoma (DLBCL) represents the most common subtype of non-Hodgkin lymphoma and accounts for approximately 30% of newly diagnosed lymphoid neoplasms in Western countries, and 40-50% in China. A better understanding of the biology of DLBCL is needed for the development of potential therapeutic agents that target specific intracellular pathways. In this study, expression of the important components of the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway and their clinical significance were investigated in 73 DLBCL cases. The effect of rituximab alone or combined with the PI3K/AKT/mTOR pathway inhibitor rapamycin was further evaluated in the DLBCL cell lines. A total of 73 patients were identified, including 45 men and 28 women aged 18 to 78 years (median age 50 years). Of these patients, p-AKT was positive in 40 cases (54.8%), p-p70S6K in 34 cases (46.6%), and p-4E-BP1 in 33 cases (45.2%). Activation of the PI3K/AKT/mTOR pathway was related to poor disease outcome in DLBCL patients treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) but not in those treated with rituximab-CHOP. Rituximab combined with rapamycin synergically downregulated the PI3K/AKT/mTOR signaling pathway. Western blot analysis revealed a baseline activation status of the PI3K/AKT/mTOR pathway in DLBCL cell lines, with high levels of p-AKT, p-mTOR, in addition to downstream molecules p-p70S6K and p-4E-BP1. The results indicate that the PI3K/AKT/mTOR pathway is a potentially important signaling route and an unfavorable prognostic factor for DLBCL. Patients with PI3K/AKT/mTOR activation experience a more rapidly deteriorating clinical course with poor treatment response and decreased survival time. Addition of rituximab could downregulate PI3K/AKT/mTOR activation, reversing its negative effect on chemotherapy-treated patients. In addition, our results indicate that the combination of rituximab and inhibition of the activated PI3K/AKT/mTOR pathway could be a promising target for DLBCL therapeutic intervention in the future.

[Z scores for growth and development, physical fitness, and the relationship between them in 362 preschool children in Yantai City, China]

OBJECTIVE

To investigate the Z scores for growth and development, physical fitness, and the relationship between them in preschool children in Yantai City, China, and to provide scientific evidence for health care in children.

METHODS

A total of 362 children aged 3 to 4 years, whose data were recorded in the National Physical Fitness Survey in Yantai in 2010, were included in the study. Z scores for weight-for-age, height-for-age and body mass index-for-age were calculated. The relationship between Z scores and physical fitness was determined by Pearson's correlation analysis.

RESULTS

The mean Z scores were all positive numbers. The prevalence rates of underweight and growth retardation were very low, but that of obesity was relatively high (up to 16.5% in 4-year-old boys). There were differences in physical fitness between children of different ages and between boys and girls (P<0.05). The Z scores showed correlation with some physical fitness indices (P<0.05), but they were not closely correlated as the value of r was not more than 0.30.

CONCLUSIONS

Z scores for growth and development remain at relatively high levels in preschool children in Yantai. The physical fitness is associated with age and gender in these children. There are weak correlations between Z scores and some physical fitness indices. Effective measures should be taken to adjust dietary habits and promote exercise for children, thus preventing obesity and improving physical fitness.

Transforming growth factor beta1 gene variation Leu10Pro affects secretion and function in hepatic cells

BACKGROUND

Our previous work revealed transforming growth factor beta1 (TGFβ1) gene polymorphisms are associated with susceptibility to hepatocellular carcinoma and liver cirrhosis. However, no further study of functional substitution in hepatic cells has yet been reported.

AIMS

This study was designed to uncover the functional mechanisms of TGFβ1 gene polymorphisms in the pathogenesis of liver diseases.

METHODS

Two recombinant TGFβ1 expression plasmids containing TGFβ1 codon 10 Leu/Pro variation were constructed with CMV promoter and transfected into human hepatoma cell lines (HepG2 and SMMU 7721), hepatic stellate cells (LX-2), and immortalized hepatocytes (L02). The secretion capacities of TGFβ1 protein in the transfected cells were determined by ELISA. Apoptosis, proliferative activity, and expression of CD 105, CD83, and CD80 were also measured by use of flow cytometry.

RESULTS

The ELISA results showed that cells transfected with CMV-Pro10 were more capable of TGFβ1 secretion than those transfected with CMV-Leu10. Functionally, CMV-Pro10 was more apoptosis-protective and induced more proliferation than CMV-Leu10 in transfected hepatic cells. Pro10 up-regulated expression of CD105 and down-regulated expression of CD83.

CONCLUSIONS

TGFβ1 gene Leu10Pro variation in signal peptide has significant effects on TGFβ1 secretion and functions in hepatic cells.

Celecoxib radiosensitizes the human cervical cancer HeLa cell line via a mechanism dependent on reduced cyclo-oxygenase-2 and vascular endothelial growth factor C expression

OBJECTIVE

The effects of celecoxib, a selective cyclo-oxygenase-2 (COX-2) inhibitor, on HeLa cervical cancer cell growth and radiosensitivity were investigated.

METHODS

Cytotoxicity was quantified using a 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyltetrazolium assay and effects on radiosensitivity were assessed using the lethal dose, quasithreshold dose, fraction surviving after 2 Gy irradiation and the radiosensitization ratio (SER, based on average lethal dose) determined using a single-hit multitarget model.

RESULTS

Celecoxib inhibited HeLa cell proliferation in a concentration- and time-dependent manner, with a half-maximal inhibitory concentration at 72 h of 44 μmol/l. Treatment with 20 μmol/l celecoxib for 72 h before irradiation was associated with an SER of 2.01. The SER of irradiated cells was 2.41 when treated with 40 μmol/l celecoxib before irradiation, 1.89 when treated simultaneously and 1.44 when treated after irradiation. Celecoxib downregulated COX-2 and vascular endothelial growth factor C (VEGF-C) expression evaluated immunohistochemically.

CONCLUSION

Celecoxib pretreatment radiosensitizes HeLa cells via a mechanism dependent on down-regulation of COX-2 and VEGF-C.

Stromal-epithelial interactions modulate the effect of ovarian steroids on goat uterine epithelial cell interleukin-18 release

A primary role of epithelial-stromal interactions in mediating steroid hormone action in the uterus has been established. The present study was undertaken to determine the mode of ovarian steroid action in regulating IL-18 release by goat endometrial epithelial cells (EECs) in the presence and absence of endometrial stromal cells (ESCs). Primary and telomerase-immortalized goat EECs grown alone or cocultured with ESCs were treated with two ovarian steroids, 17β-estradiol (E(2)) and progesterone (P(4)). The IL-18 mRNA and protein expression in EECs were studied by reverse transcript (RT) PCR, ELISA, and Western blot assay. The E(2) and/or P(4) treatment of EECs led to a significant increase in both IL-18 mRNA and protein expression either in the primary or in the immortalized EECs compared with that in EECs without the steroid treatment. However, in the presence of ESCs, IL-18 expression by EECs treated with steroids was significantly decreased compared with cells untreated with E(2) and/or P(4). In addition, significantly high abundance of IL-18 mRNA and protein expression by primary and telomerase-immortalized goat EECs was observed in the presence of ESCs compared with those cells without ESCs. These findings suggest that steroids are important for the control of IL-18 expression in goat EECs. Underlying ESCs are needed to mediate the inhibitory effects of steroids on the IL-18 secretory activity of goat EECs in vitro. The IL-18 abundance expressed by goat EECs in vitro are enhanced by underlying ESCs without the treatment of E(2) and/or P(4).

An alternative method for cDNA cloning from surrogate eukaryotic cells transfected with the corresponding genomic DNA

cDNA is widely used in gene function elucidation and/or transgenics research but often suitable tissues or cells from which to isolate mRNA for reverse transcription are unavailable. Here, an alternative method for cDNA cloning is described and tested by cloning the cDNA of human LALBA (human alpha-lactalbumin) from genomic DNA. First, genomic DNA containing all of the coding exons was cloned from human peripheral blood and inserted into a eukaryotic expression vector. Next, by delivering the plasmids into either 293T or fibroblast cells, surrogate cells were constructed. Finally, the total RNA was extracted from the surrogate cells and cDNA was obtained by RT-PCR. The human LALBA cDNA that was obtained was compared with the corresponding mRNA published in GenBank. The comparison showed that the two sequences were identical. The novel method for cDNA cloning from surrogate eukaryotic cells described here uses well-established techniques that are feasible and simple to use. We anticipate that this alternative method will have widespread applications.

Synergistic effect of bortezomib and valproic acid treatment on the proliferation and apoptosis of acute myeloid leukemia and myelodysplastic syndrome cells

The synergistic effect of proteasome inhibitor bortezomib and valproic acid (VPA), a histone deacetylase inhibitor, were investigated in this study. Co-treatment with VPA and bortezomib on acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) cell lines resulted in marked inhibition of proliferation and induction of apoptosis, including a striking increase in mitochondrial injury, caspase cascade activation, and altered expression of Bcl-2 family proteins. Moreover, combination treatment inhibited cyto-protective signaling pathways, including inactivation of nuclear factor κB (NF-κB), the extracellular signal-related kinase (ERK) and Akt pathways, and activated stress-related signaling pathway, including the c-jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38) pathways. In addition, this regimen significantly caused G2/M phase arrest, while downregulating the expression of phospho-CDC2 and CyclinD1 as well as increasing p21(cip1). Furthermore, combination treatment efficiently induced apoptosis in primary AML/MDS cells, with little effect on normal cells. In summary, these findings indicate that combination treatment with VPA and bortezomib may be a potent therapy for AML/MDS malignancies.

Dietary and supplemental intake of one-carbon nutrients and the risk of type I and type II endometrial cancer: a prospective cohort study

BACKGROUND

Type I and II endometrial cancer are biologically and clinically distinct, with type II cancers having a high frequency of p53 mutations and an association with chromosomal instability. This raises the hypothesis that one-carbon nutrients (folate, methionine, and the enzymic cofactors vitamins B2, B6, and B12), which mediate chromosomal stability and DNA methylation, may be protective for type II but not type I endometrial cancer.

METHODS

Using a prospective cohort of 23 356 postmenopausal women followed 20 years, we estimated the relative risks (RRs) of type I (N = 471) and II (N = 71) endometrial cancers according to intake of one-carbon nutrients, adjusting for confounders.

RESULTS

No associations were observed between dietary or supplemental intake of any one-carbon nutrient and risk of type I cancer. For type II cancer, positive associations were due to supplemental, rather than dietary, intake of these nutrients: supplemental folate (RR = 1.80 for >228.6 versus 0 μg/day; P trend = 0.027) and vitamins B2 (RR = 1.94 for >1.70 versus 0 mg/day; P trend = 0.011), B6 (RR = 2.08 for >2.00 versus 0 mg/day; P trend = 0.012), and B12 (RR = 2.10 for >3.43 versus 0 μg/day; P trend = 0.0060).

CONCLUSION

Contrary to our hypothesis, use of supplements containing folate and vitamins B2, B6, and B12 was associated with an increased risk of type II endometrial cancer.

The distribution of species and susceptibility of amphotericin B and fluconazole of yeast pathogens isolated from sterile sites in Taiwan

To study the demographic changes of yeasts causing invasive infections in Taiwan, especially with respect to species distribution and antifungal susceptibility, we analyzed isolates obtained from four sterile sites of patients in 19 hospitals in 2002 (155 strains) and again from the same hospitals in 2006 (208 strains). Blood was the most common source of the yeasts, accounting for 73.8% of the total isolates, followed by ascites (21.5%), cerebrospinal fluid (3%), and synovia (1.7%). Candida albicans was the most frequently recovered species (50.1% of the total), followed by Candida tropicalis (20.7%), Candida glabrata (11.6%), Candida parapsilosis (8.5%), Cryptococcus neoformans (3.9%), Candida krusei (0.8%), and nine other species (4.3%). There were one (0.3%) and seven (1.9%) isolates with minimum inhibitory concentrations (MICs) of amphotericin B > or =2 mg/l after 24 h and 48 h incubation, respectively. In addition, there were 15 (4.3%) and 31 (8.6%) isolates with MICs of fluconazole > or =64 mg/l under the same conditions. The MIC(90) value of amphotericin B was 1 mg/l. The MIC(90) values of fluconazole were 4 mg/l after 24 h incubation and 32 mg/l after 48 h incubation. Interestingly, MICs for fluconazole > or =64 mg/l after 24 h were significantly higher for isolates obtained in 2006 than those in 2002 after 24 h (7.1% vs. 0.7%, p =0.009) and 48 h (13.5% vs. 2%, p =0.0003) incubations. The demographic difference between these two surveys is mainly due to one species, C. tropicalis.

Cytostatic and anti-angiogenic effects of temsirolimus in refractory mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare and aggressive type of B-cell non-Hodgkin's lymphoma. Patients become progressively refractory to conventional chemotherapy, and their prognosis is poor. However, a 38% remission rate has been recently reported in refractory MCL treated with temsirolimus, a mTOR inhibitor.

Here we had the opportunity to study a case of refractory MCL who had tumor regression two months after temsirolimus treatment, and a progression-free survival of 10 months. In this case, lymph node biopsies were performed before and six months after temsirolimus therapy. Comparison of the two biopsies showed that temsirolimus inhibited tumor cell proliferation through cell cycle arrest, but did not induce any change in the number of apoptotic tumor cells. Apart from this cytostatic effect, temsirolimus had an antiangiogenic effect with decrease of tumor microvessel density and of VEGF expression. Moreover, numerous patchy, well-limited fibrotic areas, compatible with post-necrotic tissue repair, were found after 6-month temsirolimus therapy. Thus, temsirolimus reduced tumor burden through associated cytostatic and anti-angiogenic effects.

This dual effect of temsirolimus on tumor tissue could contribute to its recently reported efficiency in refractory MCL resistant to conventional chemotherapy.

Characterization of yeasts colonizing in healthy individuals

Opportunistic yeast pathogens may switch from harmless commensal to pathogenic relationships with the host under different conditions. They usually cause superficial infections, but may be the agents of more significant infections in immunocompromised patients. To investigate yeast colonization in the oral cavities of clinically healthy individuals, we collected oral swabs from 323 students and staff at the National Health Research Institutes, Taiwan. A total of 49 (15.2%) volunteers were colonized by low levels of yeasts and of these, only 3 (6.1%) were co-colonized by more than one species. Among the 52 isolates, comprising seven fungal genera and 13 species, Candida albicans (57.7%) was the dominant species, followed by Candida parapsilosis (15.4%). There was only one isolate of C. parapsilosis that showed, in vitro, a high (2 μg/ml) minimum inhibitory concentration (MIC) to amphotericin B. There were six (11.5%) isolates with fluconazole MICs ≥ 64 μg/ml and all of them were non-Candida species. With the exception of Cryptococcus albidus, the remaining five isolates had voriconazole MICs ≥ 4 μg/ml. In addition, there was one C. albicans isolate with relatively high fluconazole (32 μg/ml) and voriconazole (4 μg/ml) MICs.

Summary of 615 patients of chronic myeloid leukemia in Shanghai from 2001 to 2006

Background

To retrospectively review the incidence, treatment efficacy, we followed up newly diagnosed chronic myelogenous leukemia (CML) patients residing in Shanghai during 2001-2006.

Methods

All eligible cases were reviewed with the data of efficacy responses as well as overall survival (OS) and progression-free survival (PFS) time.

Results

A total of 615 cases entered the study. CML mainly afflicted those aged 40-60 years old and was slightly more frequent in males than females. More than 85% of the patients were in chronic phase (CP) when diagnosed. All patients were divided into four groups based on the main regimens - hydroxyurea, interferon alpha (IFN-α), imatinib, and hemopoietic stem cell transplantation (HSCT). With the median follow-up of 18 months, imatinib treatment induced 92.2% complete hematologic responses, and 64.3% complete cytogenetic responses among CML-CP patients. Overall the therapeutic efficacy in the imatinib group was higher than that in the hydroxyurea or IFN-α group. Meanwhile, in the imatinib group, all response rates of patients in CP were significantly greater than that in accelerated or blastic crisis phase. The patients treated with imatinib also showed the most promising results regarding OS and PFS. Patients receiving HSCT decreased markedly in number with the introduction of imatinib.

Conclusions

The number of new patients arising in Shanghai increased from 2001 to 2006. There were still patients receiving hydroxyurea and IFN-α. As the first-line regime for CML, imatinib was less administered in Shanghai before, but has received considerable development and great responses since 2003.

Experience-dependent plasticity in hypocretin/orexin neurones: re-setting arousal threshold

The neuropeptide hypocretin is synthesized exclusively in the lateral hypothalamus and participates in many brain functions critical for animal survival, particularly in the promotion and maintenance of arousal in animals - a core process in animal behaviours. Consistent with its arousal-promoting role in animals, the neurones synthesizing hypocretin receive extensive innervations encoding physiological, psychological and environmental cues and send final outputs to key arousal-promoting brain areas. The activity in hypocretin neurones fluctuates and correlates with the behavioural state of animals and intensive activity has been detected in hypocretin neurones during wakefulness, foraging for food and craving for addictive drugs. Therefore, it is likely that hypocretin neurones undergo experience-dependent changes resulting from intensive activations by stimuli encoding changes in the internal and external environments. This review summarizes the most recent evidence supporting experience-dependent plasticity in hypocretin neurones. Current data suggest that nutritional and behavioural factors lead to synaptic plasticity and re-organization of synaptic architecture in hypocretin neurones. This may be the substrate of enhanced levels of arousal resulting from behavioural changes in animals and may help to explain the mechanisms underlying the changes in arousal levels induced by physiological, psychological and environmental factors.

[Nilotinib treatment for imatinib resistant or intolerant chronic myelogenous leukemia.]

OBJECTIVE

To evaluate the safety and efficacy of nilotinib in chronic myelogenous leukemia (CML) patients with resistance or intolerance to imatinib.

METHODS

Thirty-five CML patients after imatinib failure or intolerance received oral administration of 400 mg nilotinib twice daily. The overall survival, hematologic and cytogenetic responses, as well as adverse events were evaluated.

RESULTS

The median duration of nilotinib therapy was 11 (1 - 23) months, with a median follow-up of 19 months. Nonhematologic adverse events were mostly of grade 1-2. The most common ones possibly related to nilotinib were increase of bilirubin (76%) and rash (46%). Grade 3-4 hematologic adverse events includes thrombocytopenia (37%), neutropenia (26%) and anemia (26%). Nilotinib was proved to be well-tolerated in this study. Grade 3-4 hematologic adverse events happened more frequently in advanced phase CML. The rate of major cytogenetic response in chronic phase (CP) CML was much higher than those in advanced CML (38.5% vs 22.2%). The median time to major cytogenetic response was 3 months. The estimated overall survival at 18 months was (93.5 +/- 1.0)%.

CONCLUSION

Nilotinib is a more effective and safe treatment option for imatinib-resistant or -intolerant CML-CP patients.

Characterization, physicochemical properties and biocompatibility of La-incorporated apatites

In this study, the physicochemical properties and biocompatibilities of La-containing apatites were intensively investigated together with their characterizations in terms of composition, structure, valent state and morphology using X-ray diffraction, Fourier-transform infrared spectra, X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. The results indicate that the La(3+) ion can be incorporated into the crystal lattice of hydroxyapatite resulting in the production of La-incorporated apatites (La(x)Ca(10-x)(PO(4))(6)(OH)(2+x-2y)O(y square y-x) (x> or =0.5, y<1+x/2) or La(x)Ca(10-x)(PO(4))(6)O(y square y-x) (0.5<x<2, y=1+x/2)) by high-temperature solid phase synthesis. For La content <20%, the product is composed of the major phase, La(x)-OAP, as well as a small amount of tricalcium phosphate, but for a La content of 20%, the product is pure La-incorporated oxyapatite with the formula La(2)Ca(8)(PO(4))(6)O(2) (La(2)-OAP, x=2, y=2). It is also found that the La content plays important roles in both the physicochemical properties and biocompatibilities of the La-incorporated apatites. In contrast to La-free apatite, La-incorporated apatites possess a series of attractive properties, including higher thermal stability, higher flexural strength, lower dissolution rate, larger alkaline phosphatase activity, preferable osteoblast morphology and comparable cytotoxicity. In particular, the sintered La-incorporated apatite block achieves a maximal flexure strength of 66.69+/-0.98 MPa at 5% La content (confidence coefficient 0.95), increased 320% in comparison with the La-free apatite. The present study suggests that the La-incorporated apatite possesses application potential in developing a new type of bioactive coating material for metal implants and also as a promising La carrier for further exploring the beneficial functions of La in the human body.

Ethyl pyruvate reduces mortality in an endotoxin-induced severe acute lung injury mouse model

Background

Ethyl pyruvate (EP) was recently identified as an experimental therapeutic agent in a wide variety of model systems for inflammation-mediated tissue and cellular injury.

Objective

To evaluate the effect of ethyl EP on improving the survival in mice with LPS-induced acute lung injury (ALI).

Methods

ALI was induced by administering lipopolysaccharide (LPS) intratracheally. The mice were treated intraperitoneally (i.p.) with 100, 50 and 10 mg/kg EP immediately before intratracheal instillation of LPS, and 100 mg/kg EP was administered 0, 12, 24 and 48 hours after induction of ALI. The mortality rate was recorded and analyzed by the Kaplan-Meier method. Serum tumor necrosis factor (TNF)-α, interleukin (IL) -6 and IL-1 β were measured in bronchial alveolar lavage fluid using an enzyme-linked immunosorbent assay. High-mobility group box 1 levels were measured by Western immunoblotting.

Results

Treatment with EP significantly inhibited the release of HMGB1, TNF-α, IL-6 and IL-1β into bronchoalveolar lavage (BAL) fluids of ALI mice, and reduced the permeability index of the injured lung. High EP doses reduced the mortality from ALI and the permeability index (100 mg/kg and 50 mg/kg EP versus control; P < 0.0001). Early administration of high-dose EP significantly increased survival rate (0, 12 and 24 h versus control; P < 0.0001, P < 0.0001 and P = 0.01 respectively by log-rank test). There was no survival advantage when EP was initiated at 48 h.

Conclusion

Ethyl pyruvate improves survival and reduces the lung permeability index in mice with LPS-induced ALI.

A new cell culture system for infection with hepatitis B virus that fuses HepG2 cells with primary human hepatocytes

Hepatitis B virus (HBV) infection exhibits a very narrow host range and shows a strong tropism for liver parenchymal cells, however none of the previously established experimental models can reproduce the natural process of HBV infection. In the present study, primary human hepatocytes were fused with HepG2 cells to establish the hybrid HepCHLine-4 cell line with high susceptibility to HBV. The HepCHLine-4 cells expressed HBV-specific antigen when co-incubated with HBV-positive serum from a hepatitis B patient. Post-infection, HBV relaxed circular DNA and covalently closed circular DNA were detected in HepCHLine-4 cells using a nested polymerase chain reaction, and HBV-specific particles were visualized by electron microscopy of the culture media of HepCHLine-4 cells. HepG2 cells were not susceptible to HBV infection under the same conditions. The HepCHLine-4 cells can be sub-cultured for > 12 months while maintaining susceptibility to HBV and may, therefore, be useful for studying HBV infection and the viral life cycle in human hepatocytes.

Value of serum plasma pro-brain natriuretic peptide in the diagnosis of refractory ascites due to cirrhosis

AIM: To evaluate the relationship between the plasma levels of pro-brain natriuretic peptide (proBNP) with cirrhosis severity, and to determine whether the plasma proBNP is valuable for diagnosis of refractory ascites (RA).

METHODS: The plasma levels of proBNP in 38 patients with cirrhosis were analyzed by ELISA, and the effect of proBNP on diagnosis of RA was by ROC.

RESULTS: Plasma proBNP was significantly increased in cirrhotic patients compared with healthy subjects (228.0 ± 83.4 pmol/L vs 127.4 ± 21.1 pmol/L), and was significantly correlated with CTP score (r = 0.774, P < 0.01). Levels of proBNP of patients with pre-ascites, uncomplicated ascites and refractory ascites were 169.8 ± 51.3, 238.8 ± 55.2 and 320.3 ± 63.4 pmol/L, respectively. The area values under the ROC curve generated by the proBNP were 0.857 in the diagnosis of RA, and the optimal threshold values of the proBNP was 264 pmol/L.

CONCLUSION: The plasma level of proBNP is correlated with cirrhosis severity and is valuable for diagnosis of refractory ascites.

Alterations of NR2B and PSD-95 expression in hippocampus of kainic acid-exposed rats with behavioural deficits

Temporal lobe epilepsy (TLE), characterized by spontaneous recurrent seizure (SRS), is associated with behavioural problems, but the underlying molecular mechanisms have not been clearly identified. In the present study, kainic acid (KA) was administered systemically in adult male Wistar rats to induce SRS. Behavioural performance analyses at 2, 4, and 6 weeks post-status epilepticus (post-SE) showed spatial learning memory deficit, anxiety and increased locomotor activity in rats with long-term SRS compared with rats without SRS after normal saline (NS) or KA-valproate (KA-VPA) treatment. No neuronal cell loss was observed in the hippocampus at 6 weeks post-SE. Reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot analyses revealed that down-regulation of NMDA receptor subunit 2B (NR2B) and postsynaptic density protein-95 (PSD-95) expression in adult hippocampus was found at 4 weeks post-SE and a further decrease at 6 weeks post-SE compared with rats without SRS after NS or KA-VPA treatment. Furthermore, the decreased expression of NR2B and PSD-95 was correlated with the representatively behavioural deficit. These findings suggest that long-term SRS might decrease NR2B/PSD-95 expression in adult hippocampus and consequently cause behavioural deficits, including spatial learning memory deficit, anxiety and increased locomotor activity. Maintaining the expression of NR2B/PSD-95 might partially contribute to the normal behaviour in rats with long-term SRS.

[Efficacy and safety of imatinib in treatment of 151 chronic myeloid leukemia patients]

OBJECTIVE

To evaluate the safety and efficacy of imatinib in treatment of chronic myeloid leukemia (CML) patients.

METHODS

From December 2003 to March 2007, 151 patients entered Glivec International Patient Assistance Program (GIPAP) in our center and received imatinib therapy. The overall and progression free survival, hematologic, cytogenetic and molecular response, and adverse events were evaluated. The factors associated with outcome of imatinib therapy were also analysed.

RESULTS

One hundred and forty-two patients were evaluable with a median follow-up duration of 21.5 (6 -78) months. (1) The rate of cumulative complete hematologic response (CHR), major cytogenetic response (MCyR), complete cytogenetic response (CCyR) and complete molecular response (CMoR) in chronic phase (CP) CML patients were 96.9%, 82.6%, 76.1% and 29.4%, respectively. These rates were significantly higher in patients with CP than in those with accelerated phase (AP) and blast crisis (BC) (P < 0.0001). (2) The overall survival (OS) rates at 1, 2 and 3 year were 100%, (97.3 +/- 1.9)% and (95.8 +/- 2.4)% for CP patients, they were (84.7 +/- 8.2)%, (77.0 +/- 10.4)% and (69.3 +/- 11.9)% for AP patients, and (62.9 +/- 8.9)%, (41.9 +/- 9.2)% and (28.5 +/- 9.1)% for BC patients, respectively (P < 0.0001). The progression-free survival (PFS) rates at 1, 2 and 3 year were (98.9 +/- 1.1)%, (93.9 +/- 2.7)%, (93.9 +/- 2.7)% for CP patients, (68.9 +/- 10.6)%, (61.3 +/- 11.9)%, (61.3 +/- 11.9)% for AP patients, (36.4 +/- 8.8)%, (25.4 +/- 8.1)%, (10.1 +/- 8.2)% (P < 0.0001) for BC patients respectively. (3) Among 92 CP patients, the rates of MCyR and CCyR in newly diagnosed patients were significantly higher than those in interferon therapy failure patients (P = 0.015, P = 0.010). Patients obtained CCyR at 12 months after the initiation of imatinib treatment were associated with longer PFS (P = 0.0099). According to the Sokal scoring system, the rates of MCyR and CCyR in low-risk patients were significantly higher than those in intermediate-risk and high-risk patients (P = 0.0013, P = 0.0024). Sokal score was also significantly associated with disease progression (P = 0.0467). (4) The adverse events of imatinib were moderate and tolerable.

CONCLUSIONS

Treatment of CML patients in CP with imatinib can induce high hematologic, cytogenetic and molecular response and overall survival, but can not do satisfactorily for patients in AP and BC.

Analysis of expressed sequence tags from skeletal muscle-specific cDNA library of Chinese native Xiang pig

A Longissimus Dorsi muscle cDNA library of Xiang Pig was constructed, and 131 randomly isolated clones were sequenced in this study. The results of bioinformatics analysis showed that 131 ESTs represented 109 unique clones sequences, of which 99 showed homology to previously identified genes in humans or other mammals, 3 matched other uncharacterized expressed sequence tags (ESTs), and 7 showed no significant matches to sequences already present in DNA databases. No protein matches were found for 10 ESTs. Functional analysis of the ESTs showed that a considerable proportion of them encoded proteins involved in gene/protein expression (45.46%). Other classes included genes involved in metabolism (10.10%), cell structure/motility (10.10%), cell/organism defense (5.05%), cell signaling/communication (2.02%), and cell division (0.0%). Unclassified genes constituted the remaining 27.27%. This study reported the results of the first gene expression profile analysis of Chinese native Xiang Pig skeletal muscle cells, thereby greatly facilitating the functional study of candidate genes involved in muscle growth as well as in the improvement of meat quality in domestic pigs.

[Biological characteristics of the 5' regulatory region of FSHR gene in sheep]

The 5' transcriptional promoter regulation region of FSHR gene was cloned and analyzed in Little-tailed Han sheep, Tan sheep and Australian Merino sheep. Comparison of 15 transcriptional regulatory elements in the FSHR gene showed no difference in the regulatory region of FSHR gene among the three breeds. The results showed no association between sheep breeds and 5' transcriptional promoter regulation region and eliminated the possibility that the mutation of transcriptional regulation region can affect the transcription of FSHR gene in sheep.

Similarity of RNA secondary structures

In this article, we propose a relatively similar measure to compare RNA secondary structures. We first transform an RNA secondary structure into a special sequence representation. Then, on the basis of symbolic sequence complexity, we obtain the relative distance of RNA secondary structures. The examination of similarities/dissimilarities of a set of RNA secondary structures at the 3'-terminus of different viruses illustrates the utility of the approach.

Image segmentation feature selection and pattern classification for mammographic microcalcifications

Since microcalcifications in X-ray mammograms are the primary indicator of breast cancer, detection of microcalcifications is central to the development of an effective diagnostic system. This paper proposes a two-stage detection procedure. In the first stage, a data driven, closed form mathematical model is used to calculate the location and shape of suspected microcalcifications. When tested on the Nijmegen University Hospital (Netherlands) database, data analysis shows that the proposed model can effectively detect the occurrence of microcalcifications. The proposed mathematical model not only eliminates the need for system training, but also provides information on the borders of suspected microcalcifications for further feature extraction. In the second stage, 61 features are extracted for each suspected microcalcification, representing texture, the spatial domain and the spectral domain. From these features, a sequential forward search (SFS) algorithm selects the classification input vector, which consists of features sensitive only to microcalcifications. Two types of classifiers-a general regression neural network (GRNN) and a support vector machine (SVM)--are applied, and their classification performance is compared using the Az value of the Receiver Operating Characteristic curve. For all 61 features used as input vectors, the test data set yielded Az values of 97.01% for the SVM and 96.00% for the GRNN. With input features selected by SFS, the corresponding Az values were 98.00% for the SVM and 97.80% for the GRNN. The SVM outperformed the GRNN, whether or not the input vectors first underwent SFS feature selection. In both cases, feature selection dramatically reduced the dimension of the input vectors (82% for the SVM and 59% for the GRNN). Moreover, SFS feature selection improved the classification performance, increasing the Az value from 97.01 to 98.00% for the SVM and from 96.00 to 97.80% for the GRNN.

Selective insecticide-induced stimulation on fecundity and biochemical changes in Tryporyza incertulas (Lepidoptera: Pyralidae)

The use of selective insecticides in rice, Oryza sativa L., fields often causes resurgence of nontarget pest insects. This study was conducted to investigate the effect of two selective insecticides, buprofezin and imidacloprid, on Tryporyza incertulas (Walker), a nontarget pest. After larval feeding on rice plants treated with each insecticide, fecundity, ovary protein content, and titer of juvenile hormone III (JHIII) in the resulting female moths were determined with 'Xiushui 63' rice susceptible to T. incertulas and 'Zhendao 2' moderately resistant to T. incertulas. The fecundity of females developed from larvae that fed on the insecticide-treated Xiushui 63 plants was stimulated compared with that of moths from larvae that fed on rice plants that were not treated with either insecticide. There was no stimulating effect in females from larvae that fed on insecticide-treated Zhendao 2 plants. The weight of fourth instars (final instars) that fed on the insecticide-treated Xiushui 63 rice plants was significantly greater than that of control, increasing by 50.3 and 46.7% for 60 and 112.5 g (AI) ha(-1) buprofezin, and by 23.7 and 19.5% for 15 and 37.5 g (AI) ha(-1) imidacloprid treatments, respectively. Ovary protein content in adult females developed from larvae that fed on the rice treated with the high dose of buprofezin was significantly higher than that in control. For the high and low doses of imidacloprid during the second instar, and the low dose of imidacloprid during the fourth instar, JHIII titers in female adults were also significantly higher than that in control, increasing by 152.81, 90.52, and 114.19%, respectively.

[Detection and quantification of BCR-ABL transcripts in patients with chronic myeloid leukemia by real-time quantitative reverse transcriptase polymerase chain reaction]

OBJECTIVE

To investigate the effect of real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR) approach in chronic myeloid leukemia (CML) for detecting the minimal residual disease (MRD) or monitoring the treatment response and predicting the prognosis.

METHODS

Fifty-six CML patients, 39 males and 17 females, aged 39 (16 approximately 66), with disease history and frozen RNA specimens were studied, 31 of which were in the incipient chronic phase, 7 in the accelerated phase, and 17 in the rapidly progressing phase. Three or more frozen RNA specimens collected before and after treatment were preserved in 11 of the patients. Breakpoint cluster region-Abelson murine leukemia viral oncogene (BCR-ABL) of the patients in different CML stages was analyzed by RT-PCR approach.

RESULTS

The BCR-ABL transcript of those patients remaining in chronic period after treatment decreased to 1/3 that of the baseline level six months after the initiation of treatment and then remained at that level. The BCR-ABL transcript of those in which progressing change occurred increased when such change occurred. After allogeneic transplantation of peripheral blood stem cells the BCR-ABL level decreased significantly. The median DoseN in the 17 progressing patients was 10 492, significantly higher than those of the 31 patients in chronic phase (5920) and in the 7 patients in accelerated phase (4444, both P < 0.05). The minimal residual disease and the treatment response were closely associated with the level and its variation of BCR-ABL transcripts, the transcripts level in blastic crisis was significantly higher than that in chronic phase or accelerated phase.

CONCLUSION

Real-time quantitative RT-PCR is reliable and can be used to detect the minimal residual disease, monitor the treatment outcome, and predicting blastic crisis.

[Optimizing the reaction system of DDRT-PCR by positive-cross test]

The method of mRNA Differential display PCR (DDRT-PCR) is used to identify differentially expressed genes widely. To improve further the efficiency and reproducibility of the method, the positive-cross test were performed to find the optional conditions of DDRT-PCR by analyzing the six critical parameters of dNTPs, MgCl2, arbitrary primer, anchor primer, Taq enzyme, and template systematically. The experimental findings delineated the best possible DDRT-PCR conditions for a more reliable assessment of differential gene expression. Additionally, in this study, nondenaturing polyacrylamide gel electrophoresis (PAGE) and silver straining were adopted to reduce the false-positive ratio, and the reclaimed fragments were detected by reverse Northern analysis. Finally, we obtained the optimal condition for DDRT-PCR.

Transcriptional regulation of human α1(I) procollagen gene in dermal fibroblasts

AIM: To clarify the fractional activity of promoters from human α1(I) procollagen gene, the interaction between cis-elements and consensus DNA-binding proteins responsible for high promoter activity, and the potential application of promoter competitors as well as cytokines for antifibrogenesis.

METHODS: Sequence between 2483 bp upstream of the start of transcription and 42 bp downstream of this site was investigated with serial 5’-deletion. The 5’-deleted promoters recombined with chloramphenicol acetyltransferase (CAT) as reporter gene were transiently transfected to human dermal fibroblasts. Electrophoretic mobility shift assay was performed to show the DNA-protein binding capacity of the promoter sequence. Cytokines including tumor necrosis factor α (TNFα) and interferons (INFs) were added to the culture medium of transiently transfected fibroblasts. Competitor DNA for the binding sites of Sp-1, Ap-1 and NF-1 was individually cotransfected transiently in order to block the promoter-driven CAT expression.

RESULTS: Sequences of -2483 to +42 bp and -268 to +42 bp of human α1(I) procollagen gene had high activity as promoters. Binding sites for Ap-1 and Sp-1 were among the cis-regulatory elements recognizing consensus transcription factors responsible for basal promoter activity of sequence -268 to +42 bp. TNFα, IFNα, IFNβ showed inhibitory effects on sequence -2483 to +42 bp as promoter with activities 43%, 62% and 60% of control respectively. Transfection of the promoter competitors could reverse the promoter activity of -268 to +42 bp 40%-60%.

CONCLUSION: Sequences of -2483 to +42 bp recombined with reporter gene provide an ideal construction for transcriptional study of α1(I) procollagen gene. The anti-collagen capacity of TNFα and IFNs is associated with their transcriptional regulation. Ap-1 and Sp-1 mediate the basal transcriptional activation of human α1(I) procollagen gene in dermal fibroblasts. Competitors for highly active promoters might be a novel potential candidate in fibrotic blockade.

Class II histone deacetylases: structure, function, and regulation

Acetylation of histones, as well as non-histone proteins, plays important roles in regulating various cellular processes. Dynamic control of protein acetylation levels in vivo occurs through the opposing actions of histone acetyltransferases and histone deacetylases (HDACs). In the past few years, distinct classes of HDACs have been identified in mammalian cells. Class I members, such as HDAC1, HDAC2, HDAC3, and HDAC8, are well-known enzymatic transcriptional corepressors homologous to yeast Rpd3. Class II members, including HDAC4, HDAC5, HDAC6, HDAC7, and HDAC9, possess domains similar to the deacetylase domain of yeast Hdal. HDAC4, HDAC5, and HDAC7 function as transcriptional corepressors that interact with the MEF2 transcription factors and the N-CoR, BCoR, and CtBP corepressors. Intriguingly, HDAC4, HDAC5, and probably HDAC7 are regulated through subcellular compartmentalization controlled by site-specific phosphorylation and binding of 14-3-3 proteins; the regulation of these HDACs is thus directly linked to cellular signaling networks. Both HDAC6 and HDAC9 possess unique structural modules, so they may have special biological functions. Comprehension of the structure, function, and regulation of class II deacetylases is important for elucidating how acetylation regulates functions of histones and other proteins in vivo.

Effects of polyamines on the thermal stability and formation kinetics of DNA duplexes with abnormal structure

The effects of ions (i.e. Na+, Mg2+ and polyamines including spermidine and spermine) on the stability of various DNA oligonucleotides in solution were studied. These synthetic DNA molecules contained sequences that mimic various cellular DNA structures, such as duplexes, bulged loops, hairpins and/or mismatched base pairs. Melting temperature curves obtained from the ultraviolet spectroscopic experiments indicated that the effectiveness of the stabilization of cations on the duplex formation follows the order of spermine > spermidine > Mg2+ > Na+ > Tris-HCl buffer alone at pH 7.3. Circular dichroism spectra showed that salts and polyamines did not change the secondary structures of those DNA molecules under study. Surface plasmon resonance (SPR) observations suggested that the rates of duplex formation are independent of the kind of cations used or the structure of the duplexes. However, the rate constants of DNA duplex dissociation decrease in the same order when those cations are involved. The enhancement of the duplex stability by polyamines, especially spermine, can compensate for the instability caused by abnormal structures (e.g. bulged loops, hairpins or mismatches). The effects can be so great as to make the abnormal DNAs as stable as the perfect duplex, both kinetically and thermodynamically. Our results may suggest that the interconversion of various DNA structures can be accomplished readily in the presence of polyamine. This may be relevant in understanding the role of DNA polymorphism in cells.

Mechanism of product chain length determination and the role of a flexible loop in Escherichia coli undecaprenyl-pyrophosphate synthase catalysis

The Escherichia coli undecaprayl-pyrophosphate synthase (UPPs) structure has been solved using the single wavelength anomalous diffraction method. The putative substrate-binding site is located near the end of the betaA-strand with Asp-26 playing a critical catalytic role. In both subunits, an elongated hydrophobic tunnel is found, surrounded by four beta-strands (betaA-betaB-betaD-betaC) and two helices (alpha2 and alpha3) and lined at the bottom with large residues Ile-62, Leu-137, Val-105, and His-103. The product distributions formed by the use of the I62A, V105A, and H103A mutants are similar to those observed for wild-type UPPs. Catalysis by the L137A UPPs, on the other hand, results in predominantly the formation of the C(70) polymer rather than the C(55) polymer. Ala-69 and Ala-143 are located near the top of the tunnel. In contrast to the A143V reaction, the C(30) intermediate is formed to a greater extent and is longer lived in the process catalyzed by the A69L mutant. These findings suggest that the small side chain of Ala-69 is required for rapid elongation to the C(55) product, whereas the large hydrophobic side chain of Leu-137 is required to limit the elongation to the C(55) product. The roles of residues located on a flexible loop were investigated. The S71A, N74A, or R77A mutants displayed 25-200-fold decrease in k(cat) values. W75A showed an 8-fold increase of the FPP K(m) value, and 22-33-fold increases in the IPP K(m) values were observed for E81A and S71A. The loop may function to bridge the interaction of IPP with FPP, needed to initiate the condensation reaction and serve as a hinge to control the substrate binding and product release.

Histone deacetylase 4 possesses intrinsic nuclear import and export signals

Nucleocytoplasmic trafficking of histone deacetylase 4 (HDAC4) plays an important role in regulating its function, and binding of 14-3-3 proteins is necessary for its cytoplasmic retention. Here, we report the identification of nuclear import and export sequences of HDAC4. While its N-terminal 118 residues modulate the nuclear localization, residues 244 to 279 constitute an authentic, strong nuclear localization signal. Mutational analysis of this signal revealed that three arginine-lysine clusters are necessary for its nuclear import activity. As for nuclear export, leucine-rich sequences located in the middle part of HDAC4 do not function as nuclear export signals. By contrast, a hydrophobic motif (MXXLXVXV) located at the C-terminal end serves as a nuclear export signal that is necessary for cytoplasmic retention of HDAC4. This motif is required for CRM1-mediated nuclear export of HDAC4. Furthermore, binding of 14-3-3 proteins promotes cytoplasmic localization of HDAC4 by both inhibiting its nuclear import and stimulating its nuclear export. Unlike wild-type HDAC4, a point mutant with abrogated MEF2-binding ability remains cytoplasmic upon exogenous expression of MEF2C, supporting the notion that direct MEF2 binding targets HDAC4 to the nucleus. Therefore, HDAC4 possesses intrinsic nuclear import and export signals for its dynamic nucleocytoplasmic shuttling, and association with 14-3-3 and MEF2 proteins affects such shuttling and thus directs HDAC4 to the cytoplasm and the nucleus, respectively.

Crystallographic analysis of a novel complex of actinomycin D bound to the DNA decamer CGATCGATCG

The potent anticancer drug actinomycin D (ActD) acts by binding to DNA, thereby interfering with replication and transcription. ActD inhibits RNA polymerase far more specifically than DNA polymerase. Such discrimination is not easily understood by the conventional DNA binding mode of ActD. We have solved and refined at 1.7 A resolution the crystal structure of ActD complexed to CGATCGATCG, which contains no canonical GpC binding sequence. The crystal data are space group P4(3)2(1)2, a = b = 47.01 A, and c = 160.37 A. The structure was solved by the multiple wavelength anomalous diffraction method using a 5-bromo-U DNA. The asymmetric unit of the unit cell contains two independent dimers of a novel slipped duplex complex consisting of two decamer DNA strands bound with two ActD drug molecules. (The DNA in one dimer is numbered C1 to G10 in one strand and C11 to G20 in the complementary strand and in the second dimer, C101 to G110 and C111 to G120, respectively.) The structure reveals a highly unusual ActD binding mode in which the DNA adopts a slipped duplex with the A3-T4/A13-T14 dinucleotides looped out. ActD intercalates between G2-C11* (C11* being from a symmetry-related molecule) and C5-G20 base pairs. Two such slipped duplex-ActD complexes bound to each other by mutually intercalating their T4/T14 bases into the helix cavities (located between C5-G20 and G6-C19 base pairs) of neighboring complexes, forming a dimer of drug-DNA complexes. The binding site mimics the drug binding at the elongation point during transcription. Modeling studies show that the ActD-DNA complex fits snugly in the active site cavity in RNA polymerase but not in DNA polymerase. This may explain the strong preference of ActD inhibition toward transcription.

Ramosetron for the management of chemotherapy-induced gastrointestinal events in patients with hematological malignancies

The objective of this study was to evaluate the efficacy and safety of ramosetron hydrochloride for the management of nausea and vomiting induced by chemotherapy in patients with hematological malignancies. A total of 30 patients with hematological malignancies were included in the ramosetron group. Ramosetron (0.3 mg i.v.) was administered 0.5 h before chemotherapy. The impact of ramosetron on anorexia, nausea and vomiting as well as other adverse effects were assessed. Meanwhile, another 39 patients received tropisetron (o.d. for 3 days). As compared to the tropisetron group, the response rate of the ramosetron group in controlling anorexia within 18-24 h after chemotherapy was higher (p < 0.05); within 18-24 h after chemotherapy, the complete response rate and effective rate in controlling nausea was higher (p < 0.05); within 12-18 h and 18-24 h after chemotherapy, the complete response rate and effective rate in controlling vomiting was higher (p < 0.05). The incidence of adverse effects was similar in both groups. We conclude that ramosetron belongs to a new generation of 5-HT3 receptor antagonists and that it is a safe, economic and effective antiemetic drug.