The biological mechanism and emerging therapeutic interventions of liver aging

Research on liver aging has become prominent and has attracted considerable interest in uncovering the mechanism and therapeutic targets of aging to expand lifespan. In addition, multi-omics studies are widely used to perform further mechanistic investigations on liver aging. In this review, we illustrate the changes that occur with aging in the liver, present the current models of liver aging, and emphasize existing multi-omics studies on liver aging. We integrated the multi-omics data of enrolled studies and reanalyzed them to identify key pathways and targets of liver aging. The results indicated that C-X-C motif chemokine ligand 9 (Cxcl9) was a regulator of liver aging. In addition, we provide a flowchart for liver aging research using multi-omics analysis and molecular experiments to help researchers conduct further research. Finally, we present emerging therapeutic treatments that prolong lifespan. In summary, using cells and animal models of liver aging, we can apply a multi-omics approach to find key metabolic pathways and target genes to mitigate the adverse effects of liver aging.

SMYD2 Promotes Hepatocellular Carcinoma Progression by Reprogramming Glutamine Metabolism via c-Myc/GLS1 Axis

Metabolic reprogramming, such as alterations in glutamine metabolism or glycolysis, is the hallmark of hepatocellular carcinoma (HCC). However, the underlying mechanisms are still incompletely elucidated. Previous studies have identified that methyltransferase SET and MYND domain-containing protein 2(SMYD2) is responsible for the pathogenesis of numerous types of cancer. Here, we innovatively uncover how SMYD2 regulates glutamine metabolism in HCC cells and promotes HCC progression. We identified that SMYD2 expression is upregulated in HCC tissues, which correlates with unfavorable clinical outcomes. Our in vitro and in vivo results showed that the depletion of SMYD2 inhibits HCC cell growth. Mechanistically, c-Myc methylation by SMYD2 increases its protein stability through the ubiquitin-proteasome system. We showed SMYD2 depletion destabilized c-Myc protein by increasing the conjugated K48-linked polyubiquitin chain. SMYD2 increased c-Myc expression and further upregulated glutaminase1 (GLS1), a crucial enzyme that catalyzes the conversion of glutamine to glutamic acid, in HCC cells. GLS1 plays an important role in SMYD2-mediated HCC progression and glutamine metabolism regulation. The knockdown of SMYD2 inhibited glutamine metabolism in HCC cells and overcame their chemoresistance to sorafenib. Collectively, our findings demonstrated a novel mechanism of how SMYD2 promotes HCC progression by regulating glutamine metabolism through the c-Myc/GLS1signaling, implicating the therapeutic potential of targeting SMYD2 in HCC patients.

A cross-sectional study on effectiveness of antiemetic regimens for chemotherapy-induced nausea and vomiting: A single-center retrospect study of 1,000 patients

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Background: Chemotherapy-induced nausea and vomiting (CINV) is a common symptom in patients who undergoing chemotherapy, it is very important to control CINV to maintain dose intensity and patients' quality of life. To analyse the current situation of CINV for the tumor patients who undergoing chemotherapy, we used a cross-sectional survey to assess CINV status in those patients, and whether the drugs used by doctors in each department met the guidelines, and compared the efficacy of different antiemetic regimens on acute and delayed CINV overall post-chemotherapy periods. Methods: 1,000 patients were randomly selected from 5,468 patients with chemotherapy discharged from different departments of Zhejiang cancer hospital in China between April 1 and April 30, 2019, and there were 87 responses totally. Medical records were collected on patient’s department (internal medicine, surgery, radiotherapy, interventional), chemotherapy regimens, anti-vomiting program, etc. Patients' feedbacks were recorded by CTCAE4.03 standard using MASCC antiemetic tool (Mat). Participants reported the frequency, severity, and impact on daily life of CINV from the day of chemotherapy administration up to 5 days thereafter and nausea and vomiting, as well as pharmacologic and chemotherapy used. Results: A total of 66 antineoplastic drugs were investigated, of which 52 were given intravenously and 14 orally.There were 9, 7, 50 drugs with high, moderate and low emetic risk respectively.The most prescribed prophylactic regimens for the management of CINV were aprepitant, 5-HT3R, H1-RA and dexamethasone and metoclopramide. The overall incidence of CINV were 44.34%, 24.57% and 39.66% patients reported nausea or vomiting in the acute and delayed phases. 19.89% patients had both acute and delayed CINV. The consistency rate of antiemetic with guideline was 63.19% in internal medicine department, 61.41% in surgery department and 52.91% in radiotherapy department, which showed a significant gap between the actual use of drugs and the recommended guidelines(P = 0.001). In 875 patients, 518 patients received guideline recommended antiemetic regimen, the CINV rates of complete response (CR), defined as no vomiting with no rescue medication, were 61.58%. While the CR rates in other 357 patients were 47.06%(P < 0.001). Nausea was more frequent across the overall observation period (43.77% VS 18.86%). However, vomiting was more sever and had a greater impact on life than nausea. Conclusions: Overall, adherence to the guideline recommendations in different departments were poor with varying degrees. Future studies should set hard outcomes, such as the absence of any symptoms, as a primary end point. The standardized management of CINV in patients need to be further strengthened and doctors need to use drugs more regularly to reduce the occurrence of CINV in patients.

A cross-sectional study on the effectiveness of antiemetic regimens for chemotherapy-induced nausea and vomiting: A single center retrospect study of 1,000 patients

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Background: Chemotherapy-induced nausea and vomiting (CINV) is a common symptom in patients who undergoing chemotherapy, it is very important to control CINV to maintain dose intensity and patients' quality of life. To analyse the current situation of CINV for the tumor patients who undergoing chemotherapy, we used a cross-sectional survey to assess CINV status in those patients, and whether the drugs used by doctors in each department met the guidelines, and compared the efficacy of different antiemetic regimens on acute and delayed CINV overall post-chemotherapy periods. Methods: 1,000 patients were randomly selected from 5,468 patients with chemotherapy discharged from different departments of Zhejiang cancer hospital in China between April 1 and April 30, 2019, and there were 87 responses totally. Medical records were collected on patient’s department (internal medicine, surgery, radiotherapy, interventional) , chemotherapy regimens, anti-vomiting program, etc. Patients' feedbacks were recorded by CTCAE4.03 standard using MASCC antiemetic tool (Mat). Participants reported the frequency, severity, and impact on daily life of CINV from the day of chemotherapy administration up to 5 days thereafter and nausea and vomiting, as well as pharmacologic and chemotherapy used. Results: A total of 66 antineoplastic drugs were investigated, of which 52 were given intravenously and 14 orally.There were 9, 7, 50 drugs with high, moderate and low emetic risk respectively.The most prescribed prophylactic regimens for the management of CINV were aprepitant, 5-HT3R, H1-RA and dexamethasone and metoclopramide. The overall incidence of CINV were 44.34%, 24.57% and 39.66% patients reported nausea or vomiting in the acute and delayed phases. 19.89% patients had both acute and delayed CINV. The consistency rate of antiemetic with guideline was 63.19% in internal medicine department, 61.41% in surgery department and 52.91% in radiotherapy department, which showed a significant gap between the actual use of drugs and the recommended guidelines(P = 0.001). In 875 patients, 518 patients received guideline recommended antiemetic regimen, the CINV rates of complete response (CR), defined as no vomiting with no rescue medication, were 61.58%. While the CR rates in other 357 patients were 47.06%(P < 0.001). Nausea was more frequent across the overall observation period(43.77% VS 18.86%). However, vomiting was more sever and had a greater impact on life than nausea. Conclusions: Overall, adherence to the guideline recommendations in different departments were poor with varying degrees. Future studies should set hard outcomes, such as the absence of any symptoms, as a primary end point.The standardized management of CINV in patients needs to be further strengthened and doctors need to use drugs more regularly to reduce the occurrence of CINV in patients.

Identification of hub genes and regulators associated with pancreatic ductal adenocarcinoma based on integrated gene expression profile analysis

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies without effective screening strategy during the early stage. Therefore, a novel screening panel was identified based on potential biomarkers associated with PDAC using the gene expression profile. The dataset GSE15471, which was downloaded from the Gene Expression Omnibus (GEO) database, included matching pairs of normal and tumor tissue samples from the resected pancreas of 39 pancreatic cancer patients. We used the online tool GEO2R to screen and pick out the differentially expressed genes (DEGs). Then we performed functional and pathway enrichment and constructed a DEG-associated protein-protein interaction (PPI) network by searching interacting genes in STRING. By using the visualization software Cytoscape, we sorted the modules in the PPI network and hub genes of DEGs through the MCODE and CytoHubba plugins. In total, 326 DEGs, including 306 upregulated genes and 20 downregulated genes, were targeted in PDAC. Kyoto Encyclopedia of Gene and Genome (KEGG) pathway and gene ontology (GO), based on the Database for Annotation, Visualization, and Integrated Discovery (DAVID), revealed that the DEGs are mainly involved in 'PI3K-Akt signaling pathway,' 'Focal adhesion,' and 'ECM-receptor interaction.' In addition, top 50 core genes were identified from the PPI network by CytoHubba. Gene Expression Profiling Interactive Analysis (GEPIA) survival analysis showed that high expressions of KRT7, KRT19, SEMA3C, ITGA2, MYOF, and ANXA1 may predict poor survival outcome in PDAC. Finally, Oncomine confirmed that the high expressions of these genes were strongly related to cancer grade. These hub genes and regulators straightened out the molecular pathways and recurrence mechanisms in PDAC and could be used as targets for PDAC's diagnosis, treatment, and prognostic prediction.

Estimation of Lung Volume in Normal Population Using MSCT

OBJECTIVES

To estimate lung volume in normal population by a combination of multi-slice spiral CT and Pulmo software.

METHODS

Scans of the lung were performed on 45 normal individuals using Emotion 16-slice spiral CT and Pulmo software. A measurement instrument of work station was used to measure the vertical diameter of left and right lungs, the maximum anteroposterior and transverse diameters at the layers of apex pulmonis 1 cm below, arcus aortae, subcarinal and diaphragmatic dome, and the lung volume. Regression analysis was performed on normal lung volume and each measured parameter by SPSS 20.0 and an optimal model was selected.

RESULTS

The goodness of fit between the best curvilinear equations of the normal bilateral lung volumes was 0.981. The goodness of fit between the curvilinear equations of the normal bilateral lung volume and the product of the vertical diameter and the maximum transverse diameter of diaphragmatic dome were 0.977 and 0.972, respectively. Fifteen cases were selected to make a retrospective test on the 3 models. No significant difference was found between the estimated and measured with Pulmo software lung volumes.

CONCLUSIONS

The normal lung volume before injury can be estimated by the curvilinear equations established in this study. The percentage of lung compression can be measured based on the volume of compressed lung, which can provide a reference for the identification of lung compression degree.

[5-HT(2A) receptor/protein kinase C pathway in mediating long-term facilitation of carotid sinus nerve discharge in chronic intermittent hypoxia rats]

Objective: To explore the role of 5-HT(2A)R/PKC pathway in mediating long-term facilitation (LTF) of carotid sinus nerve (CSN) discharge in chronic intermittent hypoxia (CIH) rats. Methods: With number table, 24 adult SD rats were randomly divided into saline control group (group A, n=6), 5-HT(2A)R antagonist (ketanserin) group (group B, n=6), PKC inhibitor (PKC θ-pseudosubstrate) group (group C, n=6) and combined ketanserin with PKC θ-pseudosubstrate group (group D, n=6). All rats were placed into the animal chambers for CIH treatment, 8 h per day (from 9: 00 to 17: 00) for 4 consecutive weeks. 28 days later, 5 min × 3 times of stimulation with acute intermittent hypoxia (AIH) were given, after that, stable CSN discharge activities were recorded and compared before and after intravenous injection of saline (group A), ketanserin (group B), PKC θ-pseudosubstrate (group C) or ketanserin + PKC θ-pseudosubstrate (group D), respectively. Results: There were no significant difference in the baseline (before AIH stimulation) average peak amplitude of CSN discharge among the four groups (P>0.05). In group A, the amplitude of CSN discharge at 30 min and 60 min after AIH were (5.01 ± 0.53) μV and (4.95 ± 0.34) μV respectively, which were significantly higher than that before AIH (P<0.01). The results implied that the CSN LTF could be induced by AIH in CIH pre-treatment rats. In group B, the amplitude of CSN discharge at 30 min and 60 min after AIH were (3.79 ± 0.42) μV and (3.73 ± 0.46) μV, respectively, which were still significantly higher than that before AIH (P<0.01), showing that carotid sinus nerve LTF couldn't be completely blocked by 5-HT(2A)R antagonist in rats. After injection of PKC θ-pseudosubstrate or ketanserin + PKC θ-pseudosubstrate in group C or D, there were no significant differences in CSN discharge amplitude before and after AIH (P>0.01), suggesting that inhibition of PKC alone or 5-HT(2A)R/PKC pathway could completely block the LTF of CSN. Conclusion: 5-HT(2A)R/PKC pathway was involved in mediating long-term facilitation of carotid sinus nerve discharge in CIH rats.

MiR-324-5p inhibits proliferation of glioma by target regulation of GLI1

OBJECTIVES

To study the effects of the miR-324-5p on the glioma cells proliferation via the targeted regulation of the glioma-associated oncogene 1.

METHODS

The luciferase reporter gene was used to test whether the glioma-associated oncogene 1 was the target of the miR-324-5p microRNA. The glioma-associated oncogene 1 expression was detected by Western blot. The proliferation and cell cycle were evaluated by MTT assay and flow cytometry.

RESULTS

The glioma-associated oncogene 1 is a target of the miR-324-5p. An over-expressed miR-324-5p could reduce the cell survival rate and increase the G1/G0 phase rate in the glioma cell lines.

CONCLUSIONS

The miR-324-5p can inhibit proliferation of the glioma cells via the targeted regulation of the glioma-associated oncogene 1.

Comparative study of barnidipine and felodipine in Chinese patients with essential hypertension

This study evaluated the efficacy and safety of barnidipine for the treatment of mild-to-moderate essential hypertension in Chinese patients. A total of 131 patients were randomized to receive either barnidipine (10 -15 mg) or felodipine (5 - 10 mg) once daily for 4 weeks. Both drugs reduced blood pressure significantly, with > or = 87% of patients obtaining a marked or moderate effect. The mean +/- SD reductions in systolic and diastolic blood pressure were 19.2 +/- 13.6 and 14.4 +/- 7.0 mmHg, respectively, for barnidipine treatment, and 20.3 +/- 11.3 and 14.7 +/- 7.7 mmHg, respectively, for felodipine treatment. There were no significant differences between the two drugs in terms of anti-hypertensive effect, heart rate, laboratory test results or incidence of adverse events. More patients taking felodipine experienced palpitations, but this difference was not statistically significant. Barnidipine is as efficacious and safe as felodipine in the treatment of essential hypertension in Chinese patients.

A new stabilised form of isobenzofuran, rack-mounted on an alicyclophane

New stable, crystalline isobenzofurans 9a and 9b linked through the 1,3-positions and incorporated into alicyclophanes have been prepared from the related furanoalicyclophane 5 in three steps (i) addition of benzyne or 4,5-bis(trimethylsilyl)benzyne (ii) hydrogenation of the pi-bond (iii) ejection of ethylene by flash vacuum pyrolysis, and shown to yet retain high 1,3-diene character and form adducts with dienophiles, e.g. dimethyl acetylenedicarboxylate or N-methyl maleimide; the corresponding off-rack 1,3-dimethylisobenzofurans were too unstable for isolation.

The LG3 module of laminin-5 harbors a binding site for integrin alpha3beta1 that promotes cell adhesion, spreading, and migration

Laminins are a family of extracellular matrix glycoproteins involved in cell adhesion and migration. A major obstacle to understanding their structure-function relationships is the lack of small laminin domains capable of replicating integrin-binding, cell-adhesive, and migratory functions of the intact molecule. Here, we show that the recombinant LG3 (rLG3) module (26 kDa) of laminin-5 (Ln-5) alpha(3) chain replicated key Ln-5 activities. rLG3 but not rLG1 or rLG2 supported cell adhesion and migration of at least two distinct cell lines, in an integrin alpha(3)beta(1)-dependent manner. Cell adhesion to rLG3 was regulated by divalent cations and accompanied by cell spreading and tyrosine phosphorylation of FAK focal adhesion kinase. The integrin binding activity of rLG3 was confirmed by rLG3 affinity chromatography of detergent cell lysates, which resulted in specific purification of integrin alpha(3)beta(1). To our knowledge, this is the first report directly demonstrating that a recombinant laminin LG module is an active domain capable of supporting integrin-dependent cell adhesion and migration.

[Changes in respiratory and circulatory function during sequential invasive-noninvasive mechanical ventilation]

OBJECTIVE

To investigate the change of respiratory and circulatory function in COPD during sequential invasive-noninvasive mechanical ventilation.

METHODS

12 COPD patients with type II respiratory failure were ventilated via endotracheal intubation. When pulmonary infection was under control (the appearance of "PIC Window"), all patients were extubated and received mask ventilation. The parameters of hemodynamics oxygenation and esophageal pressure were measured during endotracheal ventilation and mask ventilation (3 hrs after extubation).

RESULTS

The change of respiratory and circulatory parameters were not significantly different between invasive mechanical ventilation and noninvasive mechanical ventilation (P > 0.05).

CONCLUSION

The respiratory and circulatory function of COPD patients remained stable during sequential invasive-noninvasive mechanical ventilation.

Efficacy of continuous tracheal gas insufflation in spontaneously breathing canine with acute lung injury

OBJECTIVE

To investigate the effects of continuous tracheal gas insufflation (CTGI) combined with biphasic intermittent positive airway pressure (BIPAP) ventilation on dogs with spontaneous breathing.

METHODS

Eight canine models with oleic acid induced lung injury and spontaneous breathing were ventilated in a random order by Evita 2 (Drager Inc., Germany) in modes of BIPAP (BIPAP group) and BIPAP with CTGI flow rate of 3, 6 and 9 L/min (T3, T6 and T9 groups), respectively. The setting parameters of BIPAP were fiction of inspired oxygen 60%, inspiratory to expiratory ratio 1:1, respiratory rate 20 and positive end expiratory pressure 5 cm H2O. Arterial and mixed venous blood gas, lung mechanics, systemic and pulmonary hemodynamics status were monitored at the same level of PaCO2 obtained by adjusting peak inspiratory pressure of BIPAP.

RESULTS

Peak inspiratory pressure in the T6 group (14 +/- 4 cm H2O) and in the T9 group (11 +/- 3 cm H2O) were significantly lower than that of BIPAP (20 +/- 5 cm H2O, P < 0.01), but there was no significant difference among the T3, T6 and T9 groups or between the T3 and BIPAP groups. PaO2, mean artery blood pressure, mean pulmonary artery pressure, pulmonary artery wedge pressure, cardiac output, oxygen delivery and oxygen consumption all remained unchanged in four different conditions.

CONCLUSIONS

Using BIPAP combined with CTGI does not cause asynchrony between ventilator and spontaneous breathing, but significantly decreases airway pressure with no influence on hemodynamics and oxygenation. Therefore, BIPAP with CTGI may be a useful support technique, especially in cases where the airway pressure should be limited.

Role of the transition metal in metallaborane chemistry. Reactivity of (Cp*ReH2)2B4H4 with BH3.thf, CO, and Co2(CO)8

The reaction of Cp*ReCl4, [Cp*ReCl3]2, or [Cp*ReCl2]2 (Cp* = eta 5-C5Me5) with LiBH4 leads to the formation of 7-skeletal-electron-pair (7-sep) (Cp*ReH2)2(B2H3)2 (1) together with Cp*ReH6. Compound 1 is metastable and eliminates H2 at room temperature to generate 6-sep (Cp*ReH2)2B4H4 (2). The reaction of 2 with BH3.thf produces 7-sep (Cp*Re)2B7H7, a hypoelectronic cluster characterized previously. Heating of 2 with 1 atm of CO leads to 6-sep (Cp*ReCO)(Cp*ReH2)B4H4 (3). Both 2 and 3 have the same bicapped Re2B2 tetrahedral cluster core structure. Monitoring the reaction of 2 with CO at room temperature by NMR reveals the formation of a 7-sep, metastable intermediate, (Cp*ReCO)(Cp*ReH2)(B2H3)2 (4), which converts to 3 on heating. An X-ray structure determination reveals two isomeric forms (4-cis and 4-trans) in the crystallographic asymmetric unit which differ in geometry relative to the disposition of the metal ancillary ligands with respect to the Re-Re bond. The presence of these isomers in solution is corroborated by the solution NMR data and the infrared spectrum. In both isomers, the metallaborane core consists of fused B2Re2 tetrahedra sharing the Re2 fragment. On the basis of similarities in electron count and spectroscopic data, 1 also possesses the same bitetrahedral structure. The reaction of 2 with CO2(CO)8 results in the formal replacement of the four rhenium hydrides with a 4-electron CO2(CO)5 fragment, thereby closing the open face in 2 to produce the 6-sep hypoelectronic cluster (Cp*Re)2CO2(CO)5B4H4 (5). These reaction outcomes are compared and contrasted with those previously observed for 5-sep (Cp*Cr2)2B4H8.

mu-Oxo-bis[(2,3,12,13-tetrabromo-5,10,15, 20-tetraphenylporphyrinato)iron(III)] bis(dichloromethane) solvate

The precise structure of the title compound, [Fe(2)O(C(44)H(24)Br(4)N(4))(2)].2CH(2)Cl(2), is reported. The Fe-N distances are non-equivalent in pairs because of the asymmetric peripheral substitution; the values are 2.098 A to the brominated rings and 2.041 A to the other two rings. The Fe-O bond distance is 1.7583 (4) A. The molecule has required twofold symmetry so that there is one unique porphyrin macrocycle and one Fe-O bond length in contrast to a previous report on the same species.

An integrated approach to the mid-spin state (S = 3/2) in six-coordinate iron(III) chiroporphyrins

An intermediate-spin state very close to the mid-spin state (S = 3/2) can be stabilized in a ferric porphyrin by an integrated approach which combines the favorable effects of a weak axial field strength and of a small macrocycle hole. Axial ligand exchange by reaction of chloroiron(III)tetramethylchiroporphyrin [(TMCP)FeCl] with silver perchlorate in ethanol-chloroform leads to ethanol-ligated ferric chiroporphyrins. Two distinct crystalline products containing a bisethanol complex [[(TMCP)FeIII(EtOH)2]ClO4] and three variants of a mixed ethanol-water complex [[(TMCP)FeIII(EtOH)(H2O)]ClO4] have been structurally characterized in the solid state. The small hole of the ruffled chiroporphyrin and the weak axial oxygen ligation result in strongly tetragonally distorted complexes. The six-coordinate species exhibit long axial Fe-O bond distances (2.173(5)-2.272(4) A) and the shortest equatorial Fe-N(av) distances (1.950(5)-1.978(7) A) found as yet in a ferric porphyrin, reflecting a singly occupied dz2 orbital and a largely depopulated dx2-y2 orbital. An intriguing case of bond-stretch isomerism is seen for the axial Fe-O bonds in two crystallographically independent mixed ethanol-water species, and it is accounted for by their distinct intra- and intermolecular hydrogen-bond arrays. The Mössbauer spectrum (delta = 0.35(1) mm s-1 and delta EQ = 3.79(1) mm s-1 at 77 K) indicates a strong tetragonal distortion around the ferric ion, in agreement with the structural data. The value of the magnetic moment (mu eff = 3.8 mu B in the range 50-300 K) strongly supports a mid-spin state (S = 3/2). The EPR spectrum at 80 K (g perpendicular approximately 4.0, g parallel approximately 2.00) is consistent with a nearly pure mid-spin state (4A2) with little rhombic distortion. The 1H NMR spectra in CDCl3-EtOH exhibit upfield-shifted resonances for the pyrrole protons (delta approximately -30 ppm) which are consistent with the depopulated iron dx2-y2 orbital. Solution equilibria with water and various alcohols, and the spin state of the corresponding species, are discussed on the basis of the NMR data. The bisethanol and ethanol-water species are potential models of unknown hemoprotein ligation states such as Tyr(OH)/Tyr(OH) or Tyr(OH)/H2O that could be obtained by site-directed mutagenesis.

Fine-tuning of metallaborane geometries: chemistry of iridaboranes derived from the reaction of

From reaction of [(Cp*Ir)2HxCl(4-x)] (x=1, 0) and LiBH4, arachno-[[Cp*IrH2]B3H7](1) is produced in moderate yield concurrently with [Cp*IrH4]. In contrast, reaction of [(Cp*Ir)2H2Cl2] with LiBH4 results in arachno-[[Cp*IrH]2(mu-H)B2H5] (3) in high yield at room temperature but a mixture of 1 and [[Cp*IrH]2(mu-H)BH4] (2) at 0 degrees C. BH3 x THF converts 1 to arachno-[(Cp*IrHB4H9] (4) and 2 to 3 with 1 as a minor product. Further, reaction of 3 with excess of BH3 x THF results in formation of nido-[[Cp*Ir]2-(mu-H)B4H7] (6) formed by loss of H2 from the intermediate arachno-[[Cp*IrH]2B4H8] (5). Reaction of 1 with [Co2(CO)8] permits the isolation of two metallaboranes, arachno-[[Cp*Ir(CO)]-B3H7] (7) and nido-[1-[Cp*Ir]-2,3-Co2-(CO)4(mu-CO)B3H7] (8). Treatment of 4 with [Co2(CO)8] gives only one single mixed-metal metallaborane nido-[1-[Cp*Ir]-2-Co(CO)3B4H7 (9) in high yield. Finally, pyrolysis of 8 results in loss of hydrogen and formation of pileo-[1-[Cp*Ir]-2,3-Co2(CO)5B3H5] (10) with a BH-capped square-pyramidal structure. With kinetic control rational synthesis of a variety metallaboranes has been achieved by varying the number of chlorides in the monocyclopentadienylmetal halide dimer, reaction temperature, types of monoborane, and metal fragment sources.

[Sequential non-invasive following short-term invasive mechanical ventilation in COPD induced hypercapnic respiratory failure]

OBJECTIVE

To estimate the feasibility and the efficacy of early extubation and sequential non-invasive mechanical ventilation(MV) in COPD with exacerbated hypercapnic respiratory failure.

METHODS

22 intubated COPD cases with severe hypercapnic respiratory failure due to pulmonary infection (pneumonia or purulent bronchitis) were involved in the study. At the time pulmonary infection had been significantly controlled (resolution of fever and decrease in purulent sputum, radiographic infiltrations, and leukocytosis. We call the time as "Pulmonary Infection Control Window", PIC window) after the antibiotic and the comprehensive therapy, the early extubation was conducted and followed by non-invasive MV via facial mask immediately in 11 cases (study group). Other 11 COPD cases with similar clinical characteristics who continuously received invasive MV after PIC window were used as control group.

RESULTS

The groups had similar clinical characteristics and gas exchange, initially and at the time of PIC window. For study group and control group, the duration of invasive MV was (7.1 +/- 2.9) vs (23.0 +/- 14.0) days, P < 0.01; the total duration of ventilatory support was (13 +/- 7) vs (23 +/- 14) days, P < 0.05; the incidence of VAP were 0/11 vs 6/11, P < 0.01; the duration of ICU stay was (13 +/- 7) vs (26 +/- 14) days, P < 0.05, respectively.

CONCLUSIONS

In COPD patients requiring intubation and MV for pulmonary infection and hypercapnic respiratory failure, early extubation followed by non-invasive MV initiated at the point of PIC window may significantly decrease the invasive and total durations of ventilatory support, the risk of VAP, and the duration of ICU stay.

Molecular structure of an Fe(IV) species:

The molecular structure of the formal iron(IV) porphyrinate derivative, [[Fe(TTP)]2N]SbCl6 (TTP = tetratolylporphyrinate), is reported. The structural parameters are compared to the previously reported species [Fe(TPP)]2N, in which the iron oxidation state is +3.5. Both the equatorial and axial bond distances in [[Fe(TTP)]2N]SbCl6 are slightly shortened and consistent with an increased formal charge on iron. The value for the axial Fe-N distance is 1.6280(7) A, and the average value of the equatorial Fe-Np distances is 1.979(5) A. The Mössbauer isomer shift decreases upon oxidation, again consistent with an increase in formal charge. Values for the isomer shift at room temperature are -0.13 mm/s for [[Fe(TTP)]2N]SbCl6 and 0.04 mm/s for [Fe(TTP)]2N. Crystal data for [[Fe(TTP)]2N]SbCl6 are as follows: orthorhombic, space group Fddd, Z = 8, a = 23.689(2) A, b = 31.056(3) A, c = 22.7788(18) A.

Iron complexes of the cardioprotective agent dexrazoxane (ICRF-187) and its desmethyl derivative, ICRF-154: solid state structure, solution thermodynamics, and DNA cleavage activity

This study investigates the solution thermodynamics of the iron complexes of dexrazoxane (ICRF-187, (+)-1,2-bis(3,5-dioxopiperazinyl-1-yl)propane), [Fe(ADR-925)](+/0), and its desmethyl derivative ICRF-154, [Fe(ICRF-247)H2O](+/0). The solid state structure of [Fe(ICRF-247)H2O]+ is also reported. [Fe(ICRF-247)H2O]Br x 0.5NaBr x H2O crystallizes in the P42(1)2 space group with Z = 4, a = 14.9851(8), b = 14.9851(8), c = 8.0825(9) A and R = 0.03(2) for 1839 reflections and exhibits a pentagonal bipyramidal geometry with a labile water molecule occupying the seventh coordination site. Potentiometric titrations (FeL = 8.5 mM, 0.1 M NaNO3, 25 degrees C) reveal stable monomeric complexes (log Kf = 18.2 +/- 0.1, [Fe(ADR-925)]+, and 17.4 +/- 0.1, [Fe(ICRF-247)H2O]+) exist in solution at relatively low pH. Upon addition of base, the iron-bound water is deprotonated; the pKa values for [Fe(ICRF-247)H2O]+ and [Fe(ADR-925)]+ are 5.63 +/- 0.07 and 5.84 +/- 0.07, respectively. At higher pH both complexes undergo mu-oxo dimerization characterized by log Kd values of 2.68 +/- 0.07 for [Fe(ICRF-247)H2O]+ and 2.23 +/- 0.07 for [Fe(ADR-925)]+. In the presence of an oxidant and reductant, both [Fe(ICRF-247)H2O]+ and [Fe(ADR-925)]+ produce hydroxyl radicals that cleave pBR322 plasmid DNA at pH 7 in a metal complex concentration-dependent manner. At low metal complex concentrations (approximately 10(-5) M) where the monomeric form predominates, cleavage by both FeICRF complexes is efficient while at higher concentrations (approximately 5 x 10(-4) M) DNA cleavage is hindered. This change in reactivity is in part accounted for by dimer formation.

[Effects of continuous tracheal gas insufflation during biphasic intermittent positive airway pressure ventilation on canine model of acute lung injury with spontaneous breathing]

OBJECTIVE

To study the possibility of using continuous tracheal gas insufflation (CTGI) in dogs with spontaneous breathing.

METHODS

Eight canine with oleic acid induced lung injury which had spontaneous breathing were ventilated by Evita 2 (Drager Inc). The setting parameters were FiO(2) (60%), I/E (1:1), RR (20) and PEEP (5 cm H(2)O) in four different conditions: BIPAP (BIPAP group) and BIPAP with different CTGI flow rates (3, 6 and 9 L/min, T3, T6 and T9 group). Gas exchange, lung mechanics and hemodynamic status were monitored at the same level of PaCO(2) obtained by adjusting the high pressure (P high) of BIPAP.

RESULTS

The peak inspiratory pressures in the T6 group (14 cm H(2)O +/- 4 cm H(2)O) and T9 group (11 cm H(2)O +/- 3 cm H(2)O) were significantly lower than that of BIPAP group (20 cm H(2)O +/- 5 cm H(2)O, P < 0.01), but significant differences were not found neither among T3, T6 and T9 groups, nor between T3 and BIPAP groups. PaO(2), hemodynamics and oxygenation remained unchanged in the four different conditions.

CONCLUSION

BIPAP combined with CTGI in canine with spontaneous breathing could significantly decrease the airway pressure, with no influence on hemodynamics and oxygenation. Thus BIPAP with CTGI may be a useful support technique, especially for cases whose airway pressure should be limited.

[Continuous tracheal gas insufflation during pressure control ventilation with a pressure relief valve]

OBJECTIVE

To establish the method of continuous tracheal gas insufflation (CTGI) and investigate the role of pressure relief valve (PRV) in limiting high peak airway pressure induced by CTGI.

METHODS

CTGI device was made by authors. Nine healthy mongrel dogs were mechanically ventilated by using Evita 2 (Drager Inc.). PRV was inserted into the ventilatory circuit for selected experiment steps and adjusted a threshold pressure equal to the preset inspiratory pressure. PCV, PCV + CTGI (TGI group) and PCV + CTGI + PRV (PRV group) were conducted in different inspiration/expiration (I/E) ratio of 1:2 and 2:1. Gas exchange, lung mechanics and hemodynamics status were monitored at the constant set inspiratory pressure of PCV.

RESULTS

At the same I/E ratio, peak airway pressure in TGI group was higher than that of PRV and PCV group (P < 0.01), whereas PRV group maintained the preset inspiratory pressure as PCV group. At the different I/E ratio, peak airway pressure in TGI (2:1) group was higher than that of TGI (1:2) group(P < 0.01). PaCO2 in TGI and PRV group decreased significantly than that of PCV, TGI group was more lower than PRV group, PaO2, hemodynamics and oxygenation remained unchanged in all groups.

CONCLUSIONS

The CTGI device is effective in improving alveolar ventilation with no significant influence on hemodynamics and oxygenation; A pressure relief valve is necessary to ensure the safe use of CTGI.

[Studies on identification of yinchaihu by UV and IR]

OBJECTIVE

To study the identification of nine species of Yinchaihu derived from four genera of Caryophyllaceae, namely, Stellaria dichotoma var. lanceolata, St. dichotoma var. dichotoma, Arenaria juncea, A. capillaris var. glandulifera, Silene fortunei, Si. jenisseensis, Gypsophila pacifica, G. oldhamiana and G. licentiana.

METHOD

UV and IR of alcohol extraction.

RESULTS

The UV and IR spectra of these 9 plant roots have some difference.

CONCLUSION

St. dichotoma var. lanceolata specified in the Chinese Pharmacopoeia can be distinguished from the other plants and all these 4 genera can be differentiated from one another by both UV and first derivative spectra. The genus Stellaria can be identified from the other 3 genera by IR.

Ultraviolet Photochemistry of Co(III)L(H(2)O)SO(3)(+) [L = Me(6)[14]dieneN(4), [14]aneN(4)] Complexes. Quandaries about the Linkage Isomerization to O-Bonded Sulfite and the Photogeneration of Cobalt(I) in Sequential Biphotonic Photolysis

Two new macrocyclic complexes with S-bonded sulfite, Co(Me(6)[14]diene N(4))(H(2)O)SO(3)(+) and Co([14]ane N(4))(H(2)O)SO(3)(+), were prepared. The type of the SO(3)(2)(-) linkage in [Co(Me(6)[14]dieneN(4))(H(2)O)SO(3)]ClO(4) was established by means of the X-ray structure (crystal system, orthorhombic; space group, P2(1)2(1)2(1) (No. 19); a = 7.0342(8) Å, b = 14.696(2) Å, c = 23.302(5) Å). In a study of the photochemical properties, transient spectra revealed the photoredox formation of Co(II) macrocycles and the photoisomerization to O-bonded sulfite. Precursors of these products were also observed and tentatively identified a an ion pair (tau = 60 and 140 ns, respectively) and an adduct of the SO(3)(*)(-) radical and the unsaturated macrocycle Me(6)[14]diene N(4) (tau = 2.5 &mgr;s). The photogeneration of SO(3)(*)(-) was verified by means of the radical's ESR spectrum. High power laser irradiations resulted in the secondary photolysis of the intermediates and the formation of Co(I) products. The mechanism of the primary and secondary photolysis is discussed.

[Studies on flavonoids from Fenugreek (Trigonella foenumgraecum L.)]

OBJECTIVE

To study the flavonoids in fenugreek (Trigonella foenumgraecum) produced in China.

METHOD

The flavonoids were isolated with silica gel, polyamide and Sephadex LH-20 chromatography, and their structures were identified by physical, chemical properties and spectral analysis.

RESULT

Five flavonoid compounds were isolated from fenugreek seeds and identified as vitexin, tricin, naringenin, quercetin and tricin-7-O-beta-D-glucopyranoside.

CONCLUSION

Three flavonoids, tricin, naringenin and tricin-7-O-beta-D-glucopyranoside, were isolated from fenugreek as well as from the plants of Trigonella for the first time.

[Analysis of amino acids in Trigonella foenumgraecum seeds]

Seventeen amino acids in Trigonella foenumgraecum seeds are analyzed by means of HITACHI Model 835-50 High Speed Amino Acid Analyzer. Seven of them are essential amino acid for human body. The results provide references for evaluating the usefulness of T. foenumgraecum seeds in medicine and food.

[The inhibitory effect of antisense--RNA of papillomavirus type 16 E6E7 genes on malignant phenotypes of cervical carcinoma cell line]

In our previous study, the malignant phenotypes of the NIH3T3 cells, transformed with HPV-16 E6E7 genes, could be inhibited by the antisense RNA of HPV-16 E6E7. In this study, the antisense RNA of HPV-16 E6E7 was induced into the cervical carcinoma cells, caski, which contained HPV-16 DNA. The results showed that the cellular growth velocity was down regulated by the antisense RNA of HPV-16 E6E7, the ability of forming cellular colonies in soft agar medium and the tumorigenicity in nude mice of CaSki cells were also inhibited by the antisense cellular colonies in soft agar median and the tumorigenicity in nude mice of Caski cells were also inhibited by the antisense RNA. In addition, the decrease of the expression of viral early genes in carcinoma cells was detected with Western blot assay. It denoted that the phenotypes and the carcinogenicity of tumor cells were inhibited by the associated antisense RNA, and this may be one of the pathways inducing tumor cells reversion.

Nitrato(2,3,7,8,12,13,17,18-octaethylporphyrinato)iron(III)

The crystal structure of [Fe(C36H44N4)(NO3)] has been determined in the space group P1. The unit cell contains two molecules. The Fe atom is displaced out of the porphyrin plane by 0.50 A, the average Fe-Np distance is 2.056 (1) A (where Np is a porphyrin N atom) and the Fe-O(NO3) bond length is 2.016 (3) A.

Detection of HPV-16 DNA in cervical carcinoma by paraffin section in situ hybridization

Thirty-eight cervical carcinomas and one cervical condyloma were examined for the presence of human papillomavirus type 16 (HPV-16) DNA using 3H-dcTP-labelled HPV-16 DNA probe in paraffin section in situ hybridization and dot blot hybridization (Tm-17 degrees C). The results showed that HPV-16 DNA positive rate in our series was about 74.4% (29/39) as determined by paraffin section in situ hybridization and about 71.8% (28/29) by dot blot hybridization. There was no significant difference between the two methods. We thus confirmed that paraffin section in situ hybridization is an informative, reliable, and sensitive method for the diagnosis of cervical HPV infection.

The association between cervical carcinoma and human papilloma virus (HPV) in Xiangyuan County

A mass survey was conducted to investigate the association between cervical carcinoma and human papilloma virus (HPV) infection in a high-risk area, Xiangyuan County, Shanxi Province. Fifty-four cases of cervical cancer in situ (CIS), including severe dysplasia (CIN III), 14 cases of invasive cervical carcinoma, 28 cases of mild cervical dysplasia (CIN I), and 13 cases of moderate cervical dysplasia (CIN II) were identified among 6710 women examined. One hundred and sixty-nine punch biopsies from abnormal cervix and genital tract were examined for the presence of HPV 6B/11, 16 and 18 DNA sequences by dot blot hybridization: The positive rates of HPV infection in cervicitis, CIN I, II, III, CIS and invasive cervical carcinoma specimens were 35.06% (27/77), 25% (2/8), 33.33% (2/6), 40% (2/5), 70.58% (24/34) and 40% (4/10), respectively. Among these groups, there was no regular distribution of HPV types except for HPV 16, the positive rate of which was increased from 25% in CIN I to 46.15% in CIS: HPV 16 was also the only type seen in the invasive cervical cancer group. Distribution analysis of HPV types in HPV-positive cervical cancer tissues uncovered an HPV 16 positive rate of 59.4%; 3.7 and 2.4 times higher than those of HPV 6B/11 and HPV 18, respectively. These data confirm the close association between cervical cancer and HPV 16 infection.

Studies on emerging radiation leukemia virus variants in C57BL/Ka mice

To analyze the emergence of radiation leukemia virus (RadLV) variants in primary X-ray-induced C57BL/Ka thymoma and to identify the virus responsible for the very high leukemogenic potential of passaged Kaplan strain BL/VL3 preparation, we cloned several primary and passaged ecotropic RadLV infectious genomes. By restriction analysis, we found that BL/VL3 cells harbor three related but different ecotropic RadLVs. Their restriction map differs significantly from those of primary RadLVs. Hybridization analysis also indicated that BL/VL3 and primary RadLVs differ in their p15E and long terminal repeat (LTR) regions. As compared with the LTR sequence of the putative parental endogenous ecotropic provirus, the LTR sequence of primary weakly leukemogenic RadLV has only one change, a C-rich sequence, generating a 6-base-pair direct repeat just in front of the promotor. The LTR of the primary nonleukemogenic RadLV only showed few base changes, mainly clustered in R and U5. The LTR from a moderately leukemogenic passaged BL/VL3 RadLV had conserved the C-rich sequence and acquired a 43-base-pair direct repeat in U3 and several other point mutations, small insertions, and deletions scattered in U3, R, and U5. All cloned primary RadLVs were fibrotropic, and some were weakly leukemogenic. All cloned BL/VL3 RadLVs were thymotropic and nonfibrotropic. The block of their replication was found to be after the synthesis of unintegrated linear and supercoiled viral DNA. Most of the BL/VL3 RadLVs were moderately leukemogenic, and one (V-13) was highly leukemogenic, being as virulent as the Moloney strain. We propose a model for the emergence of the RadLV variants and show that the virus responsible for the high leukemogenic potential of BL/VL3 preparation is a nondefective, ecotropic, lymphotropic, nonfibrotropic, unique retrovirus which most likely arose from a parental primary RadLV similar to those studied here.

Molecular analysis of emerging radiation leukemia virus variants of C57BL/Ka mice

Molecular cloning of several primary or passaged RadLV variants and their biological characterization has allowed us to propose a model of their emergence following X-ray irradiation of C57BL/6 mouse.

Effect of higenamine on action potential of ventricular myocardial cells

Action potentials of isolated ventricular myocardial fibers of pigs and the electrophysiological actions of dl-demethylcoclaurine (DMC) or higenamine on the porcine myocardial cells were studied by glass microelectrodes. The action potentials of porcine ventricular myocardial fibers were similar to those of other mammalian hearts. Amplitude of the action potential was 115 +/- 9 mV, duration of action potential 242 +/- 30 ms, resting membrane potential -85 +/- 5 mV and the maximum rise of depolarization of action potential 151 +/- 27 V/s. After perfusion with normal Tyrode's solution containing DMC 5 micrograms/ml, the amplitude of action potential was increased and the duration of action potential was prolonged, the amplitude and duration of the plateau of action potential were increased and the slope of phase 2 of action potential was reduced (p less than 0.05). The resting potential, the slope of phase 3 and the maximum depolarization rate of phase 0 of action potential did not change. In Tyrode's solution containing Mn++ 3 mM, these electrophysiological actions of DMC disappeared. DMC may abolish the conduction block induced by K+-rich solution. In Tyrode's solution containing K+ 32 mM, the upstroke of action potential showed 2 phases under influence of DMC. The second phase disappeared when Mn++ was added. All findings indicate that DMC can be considered as an activator of the slow channel. The electrophysiological mechanism and clinical significance of DMC were discussed.