[Staged and segmented two hybrid surgeries for total repair of Debakey type â aortic dissection: a series of 10 cases].

Objective: To examine the efficacy and experience of staged and segmented two hybrid surgeries for total repair of Debakey type Ⅰ aortic dissection (TIAD). Methods: This study was a retrospective case series. The clinic data of 10 patients with acute TIAD who were admitted to the Department of Cardiac Surgery, Second Hospital of Lanzhou University or the First People's Hospital of Lanzhou, between January 2016 and August 2022, were retrospectively studied. Ten patients underwent hybrid surgeries in two hospitalizations (stages), including 7 males and 3 females with an age of (60±7) years (range: 49 to 71 years). In stage 1, the first type Ⅱ hybrid arch repair was performed to treat the ascending, total arch, and descending thoracic aorta for acute TIAD without circulatory arrest. In stage 2, the second hybrid surgery including infrarenal abdominal aorta replacement, visceral arteries bypass and endovascular thoracoabdominal aortic repair was performed to treat residual thoracoabdominal aortic dissection after the first hybrid operation (segmented). Basic data, preoperative concomitant diseases, high-risk factors, surgical approaches and postoperative complications of all important organs, as well as CT imaging were analyzed. Results: There was no death in the 20 hybrid surgical procedures. In stage 1 type Ⅱ hybrid surgery, 4 cases underwent reconstruction of the aortic sinutubular junction, while Bentall and David surgery was performed for 3 cases, respectively. A patient received coronary artery bypass grafting. Then all patients were sequentially treated with arch debranching and thoracic aortic endovascular repair. Postoperative complications included renal insufficiency (4/10), hemofiltration (1/10), hypoxemia (4/10), neurologic event (1/10) and type Ⅱ endoleak (1/10). Complete false lumen thrombosis occurred in 9/10 of the patients. All complications recovered successfully at discharge and the average hospital stay was (21±4) days (range: 16 to 28 days) in the first hospitalization. At stage 2, the second hybrid surgery was successfully performed in all patients. No paraplegia, hepatic or renal insufficiency, or endoleak occurred. However, branch graft embolism of the left renal artery was found in one patient 3 days after laparotomy, as well as of superior mesenteric artery in another. Superior mesenteric artery occlusion was successfully treated by endovascular recanalization. Complete false lumen thrombosis occurred in all patients. Although all patients had different degrees of intestinal dysfunction, they were gradually relieved at discharge, and the average hospital stay was (19±2)days (range:16 to 21 days) in the second hospitalization. During follow-up, CT angiography showed aortic remodeling in all patients. Conclusion: Staged and segmented two hybrid surgeries are safe and feasible for total repair of Debakey type Ⅰ aortic dissection and are associated with acceptable early and midterm outcomes.

[Analysis of bacterial pathogens and clinical characteristics of children with respiratory tract infections in Tianjin].

Objective: To analyze the pathogenic bacteria and epidemiological characteristics in children with respiratory tract infection in Tianjin area. Methods: Retrospective case analysis was performed on 2 392 hospitalized children in the wards of respiratory diseases, intensive care unit and special care ward of Tianjin Children's Hospital from June 2018 to May 2019. Thirteen pathogenic bacteria in deep sputum and bronchoalveolar lavage fluid samples were detected by loop-mediated isothermal amplification. The laboratory data and clinical characteristics of the infected children were analyzed, and the comparison between groups was performed by t test or χ2 test. Results: Among 2 392 cases, 1 407 were males and 985 females. There was no significant difference in the detection rate between males and females (72.5% (1 020/1 407) vs.74.2% (731/985), χ2=0.87, P=0.35). A total of 1 751 strains and 12 kinds of positive respiratory pathogens were detected, with a detection rate of 73.2%. Among them, 913 (38.2%) strains were Mycoplasma pneumoniae (MP), 514 (21.5%) were Streptococcus pneumoniae (Sp), 381 (15.9%) were Methicillin-resistant Staphylococcus aureus (MRSA) and 279 (11.7%) were Hemophilus influenzae (Hi). There was significant difference in the detection rate of pathogens among different age groups (χ²=83.67, P<0.01). The positive rate of alveolar lavage fluid group was higher than that of deep sputum fluid group [81.6% (614/752) vs. 69.3% (1 137/1 640), χ2=39.89, P<0.01]. The length of hospital stay of children infected with different pathogens was significantly different (all P<0.01). There was significant difference in duration of fever among children infected with different pathogens (χ²=228.69,103.56, 3.96, 27.38,24.50,41.66, all P<0.05). There were 63 (7.7%) cases of atelectasis, 260 (31.9%) cases of pleurisy and 120 (14.7%) cases of pleural effusion in MP children. Children with Sma were most likely to involve the heart system (2/9), and children with Eco infection had a higher incidence of complications such as those of blood (3/19), urinary (2/19), digestive systems(4/19), systemic inflammatory response syndrome and sepsis (1/19). Conclusions: The main bacterial pathogens of respiratory tract infection in children in Tianjin were MP, Sp, MRSA and Hi. It is suggested that clinicians should not only pay attention to the respiratory symptoms of children, but also pay attention to the complications caused by bacterial pathogen infection, so as to prevent the deterioration of the disease and improve the prognosis.

[Effects and mechanism of eleutheroside E on the growth of human hypertrophic scar fibroblasts].

Objective: To investigate the effects and mechanism of eleutheroside E on the growth of human hypertrophic scar fibroblasts (Fbs). Methods: The experimental research method was used. The hypertrophic scar tissue was collected from 6 patients with hypertrophic scar (1 male and 5 females, aged 20 to 51 (37±8) years) admitted to General Hospital of Northern Theater Command, from October 2018 to March 2019. The third to seventh passages of human hypertrophic scar Fbs were cultured for later experiments. Cells were divided into normal saline group, 100 µmol/L eleutheroside E group, 200 µmol/L eleutheroside E group, and 400 µmol/L eleutheroside E group, and normal saline, eleutheroside E at the final molarity of 100, 200, and 400 µmol/L were added to cells in the corresponding groups. Cells were collected and divided into small interfering RNA (siRNA)-negative control alone group, siRNA-thrombospondin 1 (THBS1) alone group, siRNA-negative control+400 µmol/L eleutheroside E group, and siRNA-THBS1+400 µmol/L eleutheroside E group. Cells in siRNA-negative control alone group and siRNA-negative control+400 µmol/L eleutheroside E group were transfected with siRNA-negative control, cells in siRNA-THBS1 alone group and siRNA-THBS1+400 µmol/L eleutheroside E group were transfected with siRNA-THBS1. At 24 h after transfection, cells in siRNA-negative control alone group and siRNA-THBS1 alone group were added with normal saline, and cells in siRNA-negative control+400 µmol/L eleutheroside E group and siRNA-THBS1+400 µmol/L eleutheroside E group were added with eleutheroside E at the final molarity of 400 µmol/L. At 0 (immediately), 12, 24, 36, and 48 h after treatment, the cell proliferation activity (expressed as absorbance value) was detected by thiazolyl blue assay. Cells were divided into normal saline group, 200 µmol/L eleutheroside E group, 400 µmol/L eleutheroside E group, siRNA-negative control alone group, siRNA-THBS1 alone group, siRNA-negative control+400 µmol/L eleutheroside E group, and siRNA-THBS1+400 µmol/L eleutheroside E group. The corresponding treatments in each group were the same as before. At 24 h after treatment, the apoptosis was observed by Hoechst 33258 staining. Cells were collected and divided into normal saline group, 100 µmol/L eleutheroside E group, 200 µmol/L eleutheroside E group, 400 µmol/L eleutheroside E group, siRNA-negative control alone group, siRNA-THBS1 alone group, siRNA-negative control+400 µmol/L eleutheroside E group, and siRNA-THBS1+400 µmol/L eleutheroside E group. The corresponding treatments in each group were the same as before. At 24 h after treatment, the THBS1 protein level of cells was detected by Western blotting. The number of sample in each group was all 3 at each time point. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, independent sample t test, and Bonferroni correction. Results: At 0 h after treatment, the absorbance values of cells in normal saline group, 100 µmol/L eleutheroside E group, 200 µmol/L eleutheroside E group, and 400 µmol/L eleutheroside E group were similar (P>0.05). At 12, 24, 36, and 48 h after treatment, the absorbance values of cells in 100 µmol/L eleutheroside E group, 200 µmol/L eleutheroside E group, and 400 µmol/L eleutheroside E group were significantly lower than those of normal saline group (t=7.64, 28.94, 13.69, 5.87, 6.96, 22.83, 14.75, 11.52, 21.09, 20.15, 29.52, 23.12, P<0.05 or P<0.01). At 0 h after treatment, the absorbance values of cells in siRNA-negative control alone group, siRNA-THBS1 alone group, siRNA-negative control+400 µmol/L eleutheroside E group, and siRNA-THBS1+400 µmol/L eleutheroside E group were similar (P>0.05). At 12, 24, 36, and 48 h after treatment, the absorbance values of cells in siRNA-THBS1 alone group and siRNA-negative control+400 µmol/L eleutheroside E group were significantly lower than those in siRNA-negative control alone group (t=7.14, 44.87, 20.67, 40.98, 9.26, 11.08, 15.33, 20.56, P<0.05 or P<0.01); the absorbance values of cells in siRNA-THBS1 alone group, siRNA-negative control+400 µmol/L eleutheroside E group, and siRNA-THBS1+400 µmol/L eleutheroside E group were similar (P>0.05). Compared with that in normal saline group, the numbers of apoptotic cells in 200 µmol/L eleutheroside E group and 400 µmol/L eleutheroside E group were increased at 24 h after treatment. At 24 h after treatment, compared with that in siRNA-negative control alone group, the numbers of apoptotic cells in siRNA-THBS1 alone group and siRNA-negative control+400 µmol/L eleutheroside E group were increased, while the numbers of apoptotic cells in siRNA-THBS1 alone group, siRNA-negative control+400 µmol/L eleutheroside E group, and siRNA-THBS1+400 µmol/L eleutheroside E group were similar. At 24 h after treatment, the protein levels of THBS1 of cells in 100 µmol/L eleutheroside E group, 200 µmol/L eleutheroside E group, and 400 µmol/L eleutheroside E group (0.87±0.12, 0.38±0.07, 0.20±0.09) were significantly lower than 1.83±0.17 in normal saline group (t=16.61, 16.17, 17.29, P<0.01). At 24 h after treatment, the protein levels of THBS1 of cells in siRNA-THBS1 alone group and siRNA-negative control+400 µmol/L eleutheroside E group (0.61±0.07, 0.58±0.07) were significantly lower than 1.86±0.07 in siRNA-negative control alone group (t=71.06, 83.80, P<0.01), and the protein levels of THBS1 of cells siRNA-THBS1 alone group, siRNA-negative control+400 µmol/L eleutheroside E group, and siRNA-THBS1+400 µmol/L eleutheroside E group (0.63±0.11) were similar (P>0.05). Conclusions: Eleutheroside E can inhibit the growth of human hypertrophic scar Fbs by down-regulating the expression of THBS1.

Values of long noncoding RNA SAMMSON in the clinicopathologic features and the prognostic implications of human gastric cancer.

OBJECTIVE: The aim of this study was to explore the clinical significance of lncRNA-survival associated mitochondrial melanoma-specific oncogenic non-coding RNA (lncRNA-SAMMSON) in the development and clinicopathological parameters of gastric cancer (GC). PATIENTS AND METHODS: Tissue specimens were collected from GC patients who received treatment in our hospital. Real-time quantitative polymerase chain reaction (QRT-PCR) was used to determine lncRNA-SAMMSON expression. Small interfering RNA (siRNA) was transfected to suppress the expression of lncRNA-SAMMSON in vitro. Pearson's χ2-test  was used to investigate the interaction of lncRNA-SAMMSON with clinicopathological parameters of GC patients. Kaplan-Meier method and Log rank analysis were used to analyze the progression-free survival time and overall time of GC patients. Furthermore, transwell assay and wound healing assay were conducted to determine the invasion and migration abilities of GC cells, respectively. RESULTS: QRT-PCR results showed that lncRNA-SAMMSON was abnormally overexpressed in GC tissues and cells (p<0.05). Pearson's χ2-test illustrated that clinical stage, distant metastasis and lymph node metastasis were closely related to lncRNA-SAMMSON expression in GC patients (p<0.05). Kaplan-Meier survival analysis represented that GC patients with high lncRNA-SAMMSON expression had significantly shorter progression-free survival time and overall survival time (p<0.05). Transwell assay and wound healing assay proved that inhibition of lncRNA-SAMMSON in GC cells dramatically reduced the invasion and migration abilities of GC cells, respectively (p<0.05). CONCLUSIONS: LncRNA-SAMMSON played an important role in the development of GC, which might be regarded as a new target for the diagnosis and treatment of GC.

The Function of Wnt Ligands on Osteocyte and Bone Remodeling.

Bone homeostasis is continually maintained by the process of bone remodeling throughout life. Recent studies have demonstrated that Wnt signaling pathways play a fundamental role in the process of bone homeostasis and remodeling. Intracellular Wnt signaling cascades are initially triggered by a Wnt ligand-receptor complex formation. In previous studies, the blocking of Wnt ligands from different osteoblastic differentiation stages could cause defective bone development at an early stage. Osteocytes, the most abundant and long-lived type of bone cell, are a crucial orchestrator of bone remodeling. However, the role of Wnt ligands on osteocyte and bone remodeling remains unclear. In our present study, we found that, besides osteoblasts, osteocytes also express multiple Wnt ligands in the bone environment. Then, we used a Dmp1-Cre mouse line, in which there is expression in a subset of osteoblasts but mainly osteocytes, to study the function of Wnt ligands on osteocyte and bone remodeling in vivo. Furthermore, we explored the role of Wnt ligands on osteocytic mineralization ability, as well as the regulatory function of osteocytes on the process of osteoblastic differentiation and osteoclastic migration and maturity in vitro. We concluded that Wnt proteins play an important regulatory role in 1) the process of perilacunar/canalicular remodeling, as mediated by osteocytes, and 2) the balance of osteogenesis and bone resorption at the bone surface, as mediated by osteoblasts and osteoclasts, at least partly through the canonical Wnt/ß-catenin signaling pathway and the OPG/RANKL signaling pathway.

Up-regulation of long non-coding RNA SNHG1 contributes to proliferation and metastasis in laryngeal squamous cell carcinoma.

OBJECTIVE: To investigate the expression of human long non-coding ribonucleic acid (RNA) small nucleolar RNA host gene 1 (SNHG1) in laryngeal carcinoma tissues, and to study the effect of SNHG1 on biological functions of laryngeal carcinoma HEp-2 cells. PATIENTS AND METHODS: The expression levels of SNHG1 in 20 pairs of laryngeal carcinoma tissues and para-carcinoma tissues were detected via Real-time fluorescence quantitative polymerase chain reaction (PCR). Laryngeal carcinoma cells were transfected with small interfering (si)-SNHG1 transiently using the RNA interference technique. The effects of si-SNHG1 on proliferation, apoptosis, invasion, and migration of laryngeal carcinoma HEp-2 cells were detected via cell counting kit-8 (CCK-8), colony formation assay, flow cytometry, and wound healing and Transwell assay, respectively. RESULTS: Results of PCR showed that the expression of SNHG1 in carcinoma tissues was increased compared with that in para-carcinoma tissues. Results of CCK-8 and colony formation assay revealed that SNHG1 knockdown could significantly inhibit the proliferation of laryngeal carcinoma HEp-2 cells. Flow cytometry showed that transfection with si-SNHG1 could promote the apoptosis of HEp-2 cells. Moreover, results of wound healing and Transwell assay showed that SNHG1 knockdown could inhibit invasion and migration of HEp-2 cells through inhibiting the epithelial-mesenchymal transition (EMT) process and expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9 in cells. CONCLUSIONS: The expression of SNHG1 in laryngeal carcinoma tissues is significantly higher than that in para-carcinoma tissue. Patients with high expression of SNHG1 have a poor prognosis. SNHG1 knockdown in HEp-2 cells can inhibit cell proliferation, invasion, and metastasis, and can promote apoptosis.

FOXM1 recruits nuclear Aurora kinase A to participate in a positive feedback loop essential for the self-renewal of breast cancer stem cells.

Substantial evidence suggests that breast cancer initiation, recurrence and drug resistance is supported by breast cancer stem cells (BCSCs). Recently, we reported a novel role of Aurora kinase A (AURKA) in BCSCs, as a transactivating co-factor in the induction of the c-Myc oncoprotein. However, the mode of action and transcriptional network of nuclear AURKA in BCSCs remain unknown. Here, we report that nuclear AURKA can be recruited by Forkhead box subclass M1 (FOXM1) as a co-factor to transactivate FOXM1 target genes in a kinase-independent manner. In addition, we show that AURKA and FOXM1 participate in a tightly coupled positive feedback loop to enhance BCSC phenotype. Indeed, kinase-dead AURKA can effectively transactivate the FOXM1 promoter through a Forkhead response element, whereas FOXM1 can activate AURKA expression at the transcriptional level in a similar manner. Consistently, breast cancer patient samples portrayed a strong and significant correlation between the expression levels of FOXM1 and AURKA. Moreover, both FOXM1 and AURKA were essential for maintaining the BCSC population. Finally, we demonstrated that the AURKA inhibitor AKI603 and FOXM1 inhibitor thiostrepton acted synergistically to inhibit cytoplasmic AURKA activity and disrupt the nuclear AURKA/FOXM1-positive feedback loop, respectively, resulting in a more effective inhibition of the tumorigenicity and self-renewal ability of BCSCs. Collectively, our study uncovers a previously unknown tightly coupled positive feedback signalling loop between AURKA and FOXM1, crucial for BCSC self-renewal. Remarkably, our data reveal a novel potential therapeutic strategy for targeting both the cytoplasmic and nuclear AURKA function to effectively eliminate BCSCs, so as to overcome both breast cancer and drug resistance.

Effects of dietary supplementing tannic acid in the ration of beef cattle on rumen fermentation, methane emission, microbial flora and nutrient digestibility.

Four adult Simmental male cattle (376 ± 9.0 kg initial BW), fitted with permanent rumen cannulas, were used in a 4 × 4 Latin square design to investigate the effects of dietary supplementing tannic acid (TA) on rumen fermentation, methane (CH4 ) production, rumen microbes, nutrient digestibility and plasma biochemical parameters. Four levels of TA, that is 0, 6.5, 13.0 or 26.0 g/kg dry matter (DM), were added to the basal ration (composed of corn silage and concentrate mixture) as experimental treatments respectively. Each experimental period consisted of a 12-day adaptation phase followed by a 3-day sampling phase. The results showed that supplementing TA at 26.0 g/kg DM decreased the relative abundance of protozoa, methanogens and Ruminococcus albus to the total ruminal bacterial 16S rDNA in beef cattle (p < 0.05). The results also showed that supplementing TA at 6.5, 13.0 or 26.0 g/kg DM decreased (p < 0.01) the CH4 production (l/kg DM intake) by 11.1%, 14.7% and 33.6% respectively. Supplementing TA at 13.0 or 26.0 g/kg DM decreased the ratio of acetate to propionate and ammonia nitrogen (NH3 -N) (p < 0.05) and tended to decrease the total volatile fatty acid (VFA) concentration of rumen fluid (p = 0.07). Supplementing TA at 26.0 g/kg DM decreased DM and organic matter (OM) digestibility (p < 0.05), supplementing TA at 6.5, 13.0 or 26.0 g/kg DM decreased (p < 0.01) crude protein (CP) digestibility by 5.0%, 8.6% and 15.7%, respectively, and supplementing TA at 6.5, 13.0 or 26.0 g/kg DM increased (p < 0.05) the plasma total antioxidant capability. It was concluded that supplementing TA in the ration of beef cattle decreased the CH4 production and digestibility of CP of beef cattle. Supplementing TA could be an effective option to mitigate CH4 emission form cattle, further research is necessary to study the effects of TA on the performance of cattle.

[Clinical characteristics and prognosis in 12 patients with adult T cell leukemia/lymphoma confirmed by HTLV-1 provirus gene detection].

Objective: To analyze the clinical characteristics and prognosis of adult T cell leukemia/lymphoma (ATLL). Methods: Peripheral blood samples from patients who were suspected as ATLL from March, 2013 to July, 2015, were collected for HTLV-1 provirus genes detection in genomic DNA extraction by PCR. Cases showing positive results were confirmed as ATLL. Clinical and laboratory characteristics, therapeutic outcomes and survival evaluation were collected. Results: 12 out of 23 suspected patients were confirmedly diagnosed as ATLL through HTLV-1 provirus genes detection by PCR. Eight patients were male and four patients were female. Median age was 51 (range 28-66) years old. All of those patients came from coastal cities of Fujian province where a HTLV-1 epidemic area locates. In the subtype classification of these 12 ATLL, 11 patients were classified as acute type and one case as lymphoma type ATLL. As one of the clinical characteristics of ATLL, ' flower cells ', with typical or atypical morphology had been observed in a high rate (81.8%). Clinical symptom such as hepatomegaly, splenomegaly and lymphadenectasis were detected in most of patients, and hypercalcemia and elevated LDH were also noted commonly. The ATLL cells immunophenotype were typical, and the major subtype was CD4+ CD8- type. Confection of hepatitis B virus was detected in a high rate (54.5%). Ten patients received chemotherapy, and 2 cases in complete remission after chemotherapy received allogeneic hematopoietic stem cell transplantation. At the end of the follow-up, 7 cases died, 4 cases survived, 1 case was lost, and the median survival was 2.8 (0.9-10.8) months. We found a case had HTLV-1 provirus negative after transplantation. Conclusion: In the coastal area of Fujian Province, ATLL is not rare. Characteristics of those ATLL are typical. But prognosis is still unsatisfactory.

Managing complex respiratory patients in the community: an evaluation of a pilot integrated respiratory care service.

INTRODUCTION: In the UK, there is significant variation in respiratory care and outcomes. An integrated approach to the management of high-risk respiratory patients, incorporating specialist and primary care teams' expertise, is the basis for new integrated respiratory services designed to reduce this variation; however, this model needs evaluating. METHODS: To evaluate an integrated service managing high-risk respiratory patients, electronic searches for patients with asthma and chronic obstructive pulmonary disease at risk of poor outcomes were performed in two general practitioner (GP) practices in a local service-development initiative. Patients were reviewed at joint clinics by primary and secondary care professionals. GPs also nominated patients for inclusion. Reviews were delivered to best standards of care including assessments of diagnosis, control, spirometry, self-management, education, medication, inhaler technique and smoking cessation support. Follow-up of routine clinical data collected at 9-months postclinic were compared with seasonally matched 9-months prior to integrated review. RESULTS: 82 patients were identified, 55 attended. 13 (23.6%) had their primary diagnosis changed. In comparison with the seasonally adjusted baseline period, in the 9-month follow-up there was an increase in inhaled corticosteroid prescriptions of 23.3%, a reduction in short-acting ß2-agonist prescription of 33.3%, a reduction in acute respiratory exacerbations of 67.6%, in unscheduled GP surgery visits of 53.3% and acute respiratory hospital admissions reduced from 3 to 0. Only 4 patients (7.3%) required referral to secondary care. Health economic evaluation showed respiratory-related costs per patient reduced by £231.86. CONCLUSIONS: Patients with respiratory disease in this region at risk of suboptimal outcomes identified proactively and managed by an integrated team improved outcomes without the need for hospital referral.

Effects of supplementing rare earth element cerium on rumen fermentation, nutrient digestibility, nitrogen balance and plasma biochemical parameters in beef cattle.

The objectives of the trial were to investigate the effects of supplementing rare earth element (REE) cerium (Ce) on rumen fermentation, nutrient digestibility, methane (CH4 ) production, nitrogen (N) balance and plasma biochemical parameters in beef cattle. Four Simmental male cattle, aged at 14 months, with initial liveweight of 355 ± 8 kg and fitted with permanent rumen cannulas, were used as experimental animals. The cattle were fed with a total mixed ration (TMR) composed of concentrate mixture and corn silage. Four levels of cerium chloride (CeCl3 ·7H2 O, purity 99.9%), that is 0, 80, 160 and 240 mg CeCl3 /kg DM, were added to basal ration in a 4 × 4 Latin square design. Each experimental period lasted 15 days, of which the first 12 days were for pre-treatment and the last 3 days were for sampling. The results showed that supplementing CeCl3 at 160 or 240 mg/kg DM increased neutral detergent fibre (NDF) digestibility (p < 0.05) and tended to increased acid detergent fibre (ADF) digestibility (p = 0.083). Supplementing CeCl3 at 80, 160 or 240 mg/kg DM decreased the molar ratio of rumen acetate to propionate linearly (p < 0.05). Supplementing CeCl3 at 160 or 240 mg/kg DM decreased total N excretion, urinary N excretion and increased N retention (p < 0.05), increased excretion of total urinary purine derivatives (PD) (p < 0.05) and decreased CH4 /kg DMI (p < 0.05). In conclusion, supplementing CeCl3 at 160 or 240 mg/kg DM in the ration of beef cattle increased the digestibility of NDF, decreased the molar ratio of rumen acetate to propionate, increased N retention and microbial N flow and decreased CH4 /kg DMI.

Effects of rare earth element lanthanum on rumen methane and volatile fatty acid production and microbial flora in vitro.

The objectives of the trial were to study the effects of rare earth element (REE) lanthanum (La) on the in vitro rumen methane (CH4 ) and volatile fatty acid (VFA) production and the microbial flora of feeds. Four feed mixtures with different levels of neutral detergent fibre (NDF), that is 20.0% (I), 31.0% (II), 41.9% (III) and 52.7% (IV), were formulated as substrates. Five levels of LaCl3 , that is 0, 0.4, 0.6, 0.8 and 1.0 mmol/kg dry matter (DM), were added to the feed mixtures, respectively, as experimental treatments in a two-factor 5 × 4 randomized design. The in vitro incubation lasted for 24 h. The results showed that supplementing LaCl3 increased the total gas (p < 0.001) production and tended to increase the total VFA production (p = 0.072) and decreased the CH4 production (p = 0.001) and the ratios of acetate/propionate (p = 0.019) and CH4 /total VFA (p < 0.001). Interactions between LaCl3 and NDF were significant in total gas production (p = 0.030) and tended to be significant in CH4 production (p = 0.071). Supplementing LaCl3 at the level of 0.8 mmol/g DM decreased the relative abundance of methanogens and protozoa in the total bacterial 16S rDNA analysed using the real-time PCR (p < 0.0001), increased F. succinogenes (p = 0.0003) and decreased R. flavefaciens (p < 0.0001) whereas did not affect R. albus and anaerobic fungi (p > 0.05). It was concluded that LaCl3 decreased the CH4 production without negatively affecting feed digestion through manipulating rumen microbial flora when feed mixtures with different levels of NDF were used as substrates.

A challenge for medicinal chemistry by the 17ß-hydroxysteroid dehydrogenase superfamily: an integrated biological function and inhibition study.

Members of the 17ß-hydroxysteroid dehydrogenase (17ß-HSD) superfamily perform distinct multiple catalyses by the same enzyme, apparently contradictory to the long-held beliefs regarding the high specificity of enzymes. Surprisingly, these multi-catalyses can combine synergistically in vitro and in vivo and their dysfunction may result in the stimulation of breast or prostate cancer. 17ß-HSD1 possesses high estrogen activation activity, while its androgen inactivation is significant for decreasing the week concentration of dihydrotestosterone (DHT) in breast cancer cells, an important factor for cell proliferation. 17ß-HSD5 can also carry out multiple catalyses in hormone-dependent cancer cells. In addition to 17ß-HSDs 1 and 5 some other family members possess such dual-activity as well, and their inhibition decreases hormone- dependent cancer proliferation. The multi-specificity of 17ß-HSD1 is structurally based on the pseudo-symmetric androgens that can accommodate the narrow enzyme substrate tunnel by both normal and alternative binding. The atypical family member 17ß-HSD5 possesses a spacious binding site, which is accessible to several substrates. Expression of 17ß- HSD1 can also control other estrogen-responsive elements such as pS2, and can regulate steroid-hormone receptors. The fundamental involvement of 17ß-HSD1 in catalysis and gene regulation underlies its close relationship to breast cancer, attributable to its long evolutionary process. These observations stimulated detailed study of steroid-converting enzyme inhibition. The most significant efforts in designing 17ß-HSD1 inhibitors in decades have progressed through structure activity relationship studies supported by the availability of both small and protein molecule structures, with the elimination of residual estrogenic activity in the inhibitors. The first non-estrogenic inhibitors of 17ß-HSD1 to show activity in vivo (breast cancer animal model) are now reported.

Design and synthesis of bisubstrate inhibitors of type 1 17beta-hydroxysteroid dehydrogenase: overview and perspectives.

Type 1 17beta-hydroxysteroid dehydrogenase (17beta-HSD1) is a key steroidogenic enzyme that catalyses the reduction of steroid estrone into the most potent endogenous estrogen estradiol using the cofactor NAD(P)H. Bisubstrate inhibition is a good way to enhance the potency of inhibitors of cofactor-assisted enzymes. The design of a bisubstrate inhibitor of 17beta-HSD1, the estradiol/adenosine hybrid EM-1745, is reviewed and strategies for future designs of inhibitors are proposed.

Cinnamomin: separation, crystallization and preliminary X-ray diffraction study.

Cinnamomin from Cinnamonum camphora seeds, a type II ribosome-inactivating protein that interferes with protein biosynthesis in mammalian cells, can induce the apoptosis of carcinoma cells and be used as an insecticide. A rapid and improved method has been developed for the extraction and purification of cinnamomin from camphora seed. Purification of cinnamomin is achieved with two successive steps of hydrophobic interaction chromatography carried out on a fast protein liquid chromatography (FPLC) system. Crystals suitable for X-ray diffraction analysis were obtained by vapor diffusion method. A complete data set at 2.8 A resolution has been collected. Data indexation and refinement indicate that the crystal is orthorhombic with space group P2(1)2(1)2(1) and unit cell dimensions a = 52.39 A, b = 126.33 A, c = 161.45 A. There are two molecules per asymmetric unit. Initial phasing by molecular replacement method yielded a solution, which will contribute to the structure determination. A molecular model will further the understanding of the mechanism of cinnamomin function. The latter will be combined with bio-informatics to facilitate the medical and other applications of cinnamomin.

Crystallization and preliminary X-ray diffraction analysis of E. coli arginyl-tRNA synthetase in complex form with a tRNAArg.

Amino acids are building blocks of proteins, while aminoacyl-tRNA synthetases (aaRSs) catalyze the first reaction in such building: the biosynthesis of proteins. The E. coli arginyl-tRNA synthetase (ArgRS) has been crystallized in complex form with tRNA(Arg) (B. stearothermophilus), at pH 5.6 using ammonium sulfate as a precipitating agent. Two crystal forms have been identified based on unit cell dimension. The complete data sets from both crystal forms have been collected with a primitive hexagonal space group. A data set of Form II crystals at 3.2 A and 94% completeness has been obtained, with unit cell parameters a = b = 98.0 A, c = 463.2 A, and alpha = beta = 90 degrees , gamma = 120 degrees , being different from a = b = 110.8 A, c = 377.8 A for form I. The structure determination will demonstrate the interaction of these two macromolecules to understand the special mechanism of ArgRS that requires the presence of tRNA for amino acid activation. Such complex structure also provides a wide opening for inhibitor search using bioinformatics.

Autoimmunity to type VII collagen in SKH1 mice is independent of regulatory T cells.

Epidermolysis bullosa acquisita is an autoimmune blistering disease characterized by circulating and skin basement membrane-bound IgG autoantibodies to type VII collagen, a major structural protein of the dermal-epidermal junction. Regulatory T cells (T(reg)) suppress self antigen-mediated autoimmune responses. To investigate the role of T(reg) in the the autoimmune response to type VII collagen in a mouse model, a monoclonal antibody against mouse CD25 was used to deplete T(reg). A recombinant mouse type VII collagen NC1 domain protein and mouse albumin were used as antigens. SKH1 mice were used as a testing host. Group 1 mice received NC1 immunization and were functionally depleted of T(reg); group 2 mice received NC1 immunization and rat isotype control; and group 3 mice received albumin immunization and were functionally depleted of T(reg). Results demonstrated that anti-NC1 IgG autoantibodies with high titres, as determined by enzyme-linked immunosorbent assay and Western blotting, developed in all mice immunized with NC1 (groups 1 and 2), but were undetected in group 3 mice. The predominant subclasses of anti-NC1 autoantibodies were IgG1, IgG2a and IgG2b; furthermore, these antibodies carried only the kappa light chain. IgG autoantibodies in the sera of NC1-immunized mice reacted with mouse skin basement membrane in vitro and deposited in skin basement membrane in vivo as detected by indirect and direct immunofluorescence microscopy, respectively. Our data suggest that the development of autoimmunity against type VII collagen in mice is independent of T(reg) function and the autoimmune response is mediated by both Th1 and Th2 cells. We speculate that the basement membrane deposition of IgG may eventually lead to blister development.

Attempts to rationalize protein crystallization using relative crystallizability.

Protein crystal growth (PCG) remains the bottleneck of crystallography despite many decades of study. The nucleation zone in the two-dimensional-phase diagram has been used to evaluate the relative crystallizability of proteins, which is expressed as a percentage over the phase area delineated by experimental protein and precipitating agent concentration ranges. For protein-salts which are subject to a direct temperature effect on solubility, as represented by Egg Lysozyme, a decrease in temperature augments the nucleation zone percentage whereas for those with retrograde solubility as a function of temperature, for example fructose-1,6-bisphosphatase in the presence and absence of AMP, an increase in temperature can significantly enhance the relative crystallizability. These results have been confirmed by the number of "hits" using PEGs as precipitating agents in Sparse Matrix Screen experiments for different proteins and are in excellent agreement with the relative crystallizability. The relationship between solubility dependence, relative crystallizability and crystallization success, has been evidenced. Such crystallizability can become a guide to identify efficient crystallization regions, providing a rational approach to PCG and structural biology.