Design of Potent and Proteolytically Stable Biaryl-Stapled GLP-1R/GIPR Peptide Dual Agonists

Recent clinical trials have revealed that the chimeric peptide hormones simultaneously activating glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) demonstrate superior efficacy in glycemic control and body weight reduction, better than those activating the GLP-1R alone. However, the linear peptide-based GLP-1R/GIPR dual agonists are susceptible to proteolytic cleavage by common digestive enzymes present in the gastrointestinal tract and thus not suitable for oral administration. Here, we report the design and synthesis of biaryl-stapled peptides, with and without fatty diacid attachment, that showed potent GLP-1R/GIPR dual agonist activities. Compared to a linear peptide dual agonist and semaglutide, the biaryl-stapled peptides displayed drastically improved proteolytic stability against the common digestive enzymes. Furthermore, two stapled peptides showed excellent efficacy in an oral glucose tolerance test in mice, owing to their potent receptor activity in vitro and good pharmacokinetics exposure upon subcutaneous injection. By exploring a more comprehensive set of biaryl staplers, we expect that this stapling method could facilitate the design of the stapled peptide-based dual agonists suitable for oral administration.

Publisher Correction: Electronic structure of the parent compound of superconducting infinite-layer nickelates

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Electronic structure of the parent compound of superconducting infinite-layer nickelates

The search continues for nickel oxide-based materials with electronic properties similar to cuprate high-temperature superconductors^1-10. The recent discovery of superconductivity in the doped infinite-layer nickelate NdNiO₂ (refs. ^11,12) has strengthened these efforts. Here, we use X-ray spectroscopy and density functional theory to show that the electronic structure of LaNiO₂ and NdNiO₂, while similar to the cuprates, includes significant distinctions. Unlike cuprates, the rare-earth spacer layer in the infinite-layer nickelate supports a weakly interacting three-dimensional 5d metallic state, which hybridizes with a quasi-two-dimensional, strongly correlated state with [Formula: see text] symmetry in the NiO₂ layers. Thus, the infinite-layer nickelate can be regarded as a sibling of the rare-earth intermetallics^13-15, which are well known for heavy fermion behaviour, where the NiO₂ correlated layers play an analogous role to the 4f states in rare-earth heavy fermion compounds. This Kondo- or Anderson-lattice-like 'oxide-intermetallic' replaces the Mott insulator as the reference state from which superconductivity emerges upon doping.

Nidufexor (LMB763), a Novel FXR Modulator for the Treatment of Nonalcoholic Steatohepatitis

Farnesoid X receptor (FXR) agonists are emerging as important potential therapeutics for the treatment of nonalcoholic steatohepatitis (NASH) patients, as they exert positive effects on multiple aspects of the disease. FXR agonists reduce lipid accumulation in the liver, hepatocellular inflammation, hepatic injury, and fibrosis. While there are currently no approved therapies for NASH, the bile acid-derived FXR agonist obeticholic acid (OCA; 6-ethyl chenodeoxycholic acid) has shown promise in clinical studies. Previously, we described the discovery of tropifexor (LJN452), the most potent non-bile acid FXR agonist currently in clinical investigation. Here, we report the discovery of a novel chemical series of non-bile acid FXR agonists based on a tricyclic dihydrochromenopyrazole core from which emerged nidufexor (LMB763), a compound with partial FXR agonistic activity in vitro and FXR-dependent gene modulation in vivo. Nidufexor has advanced to Phase 2 human clinical trials in patients with NASH and diabetic nephropathy.

Coulomb Correlations Intertwined with Spin and Orbital Excitations in LaCoO_{3}

We carried out temperature-dependent (20-550 K) measurements of resonant inelastic x-ray scattering on LaCoO_{3} to investigate the evolution of its electronic structure across the spin-state crossover. In combination with charge-transfer multiplet calculations, we accurately quantified the renomalized crystal-field excitation energies and spin-state populations. We show that the screening of the effective on-site Coulomb interaction of 3d electrons is orbital selective and coupled to the spin-state crossover in LaCoO_{3}. The results establish that the gradual spin-state crossover is associated with a relative change of Coulomb energy versus bandwidth, leading to a Mott-type insulator-to-metal transition.

[Efficacy and safety analysis of ivabradine hydrochloride treatment of Chinese patients with chronic heart failure: subgroup analysis of Chinese patients in the SHIFT study]

Objective: To evaluate the efficacy and safety of ivabradine for the treatment of Chinese patients with chronic heart failure based on the Chinese subgroup data of the systolic heart failure treatment with the I(f) inhibitor ivabradine trial (SHIFT). Method: A total of 6 558 stable outpatients who presented symptoms of heart failure, with a left ventricular ejection fraction (LVEF) ≤35%, sinus rhythms with a heart rate ≥70 bpm participated in the randomized, double-blind, placebo-controlled, international multicenter clinical study.The subset of Chinese patients with heart rate ≥75 bpm was enrolled in the post-hoc subgroup analyses.Patients were randomly allocated by computer-generated assignment through a telephone interactive voice response system to ivabradine group (starting dose 5 mg bid, which was then uptitrated to the maximum 7.5 mg bid) or matched placebo group.The clinical baseline characteristics of participants were obtained and analyzed.The primary outcome endpoint was a composite endpoint of cardiovascular death or hospitalization resulting from worsening HF.The primary safety endpoint included total incidence of adverse events during the study, bradycardia, and adverse visual reaction (phosphenes). Results: A total of 49 Chinese centers enrolled a total of 225 patients with chronic heart failure, of whom, 106 patients were randomized to the ivabradine group and the other 119 patients to the placebo group, and the mean follow-up time was (15.6±5.1) months.By the end of the study, mean heart rate (71.0 bpm vs. 80.3 bpm, P<0.05) and incidence of the primary endpoint events (18.9% (20/106) vs. 31.9%(38/119), HR=0.56, 95%CI 0.33-0.97, P=0.039) were significantly lower, while the percentage of patients with improvement in heart functional class NYHA (53.8% (56/106) vs. 34.5% (41/119), P=0.006 1) was significantly higher in the ivabradine group than in the placebo group.The total number of adverse events (129 events, 49.6% PY) in the ivabradine group was lower than that in the placebo group (203 events, 50.8% PY). In the ivabradine group and the placebo group, there were respectively 2 patients (1.9%) and 0 patients experienced bradycardia, 3 patients (2.9%) and 1 patient (0.8%) experienced adverse visual reaction (phosphenes). Conclusions: Ivabradine significantly reduced heart rate and improved the clinical outcomes and NYHA function class in Chinese patients with chronic heart failure, these beneficial effects are achieved without inducing remarkable adverse reactions.The results of Chinese subgroup analysis were thus consistent with the overall results of the SHIFT study. Clinical Trial Registry: International standard randomized controlled trials registry, ISRCTN 70429960.

Jahn-Teller distortion driven magnetic polarons in magnetite

The first known magnetic mineral, magnetite, has unusual properties, which have fascinated mankind for centuries; it undergoes the Verwey transition around 120 K with an abrupt change in structure and electrical conductivity. The mechanism of the Verwey transition, however, remains contentious. Here we use resonant inelastic X-ray scattering over a wide temperature range across the Verwey transition to identify and separate out the magnetic excitations derived from nominal Fe²⁺ and Fe³⁺ states. Comparison of the experimental results with crystal-field multiplet calculations shows that the spin–orbital dd excitons of the Fe²⁺ sites arise from a tetragonal Jahn-Teller active polaronic distortion of the Fe²⁺O₆ octahedra. These low-energy excitations, which get weakened for temperatures above 350 K but persist at least up to 550 K, are distinct from optical excitations and are best explained as magnetic polarons.

The Verwey transition of magnetite is complex due to the coexistence of strong correlations and electron-phonon coupling. Here, the authors use resonant inelastic X-ray scattering to show evidence for magnetic polarons in magnetite and provide insight into the nature of the transition.

Doping Dependence of Collective Spin and Orbital Excitations in the Spin-1 Quantum Antiferromagnet La_{2-x}Sr_{x}NiO_{4} Observed by X Rays

We report the first empirical demonstration that resonant inelastic x-ray scattering (RIXS) is sensitive to collective magnetic excitations in S=1 systems by probing the Ni L_{3} edge of La_{2-x}Sr_{x}NiO_{4} (x=0, 0.33, 0.45). The magnetic excitation peak is asymmetric, indicating the presence of single and multi-spin-flip excitations. As the hole doping level is increased, the zone boundary magnon energy is suppressed at a much larger rate than that in hole doped cuprates. Based on the analysis of the orbital and charge excitations observed by RIXS, we argue that this difference is related to the orbital character of the doped holes in these two families. This work establishes RIXS as a probe of fundamental magnetic interactions in nickelates opening the way towards studies of heterostructures and ultrafast pump-probe experiments.

[Research of the Epworth sleepiness scale based on ruzzy comprehensive evaluation]

Objective:This research explores the effect of Epworth sleepiness scale (ESS) items on domestic patients. Method:Four thousand six hundred and thirty-three suspected OSAHS patients with snoring were selected from respiratory sleep center in the first people's hospital, Yunnan province, between January 2006 and December 2012. These patients filled in the ESS before PSG test. Firstly, these questionnaires were preprocessed, and the null and incorrect ones were deleted. Then, the fuzzy comprehensive evaluation was applied for the value of each item in ESS. Finally, the reliability was compared between before and after the removal of the lowest values.Result:Fuzzy comprehensive evaluation results show that the total value is 1.016, the item value of Sitting and talking to someone and In a car, while stopped for a few minutes in traffic is the lowest, which is 0.131. The result of reliability analysis shows that the value increases 0.2% after the two items being deleted.Conclusion:Some items of ESS are not suitable for Chinese patients, and they need to be deleted or modified to improve the screening efficiency.

Orbital Engineering in Nickelate Heterostructures Driven by Anisotropic Oxygen Hybridization rather than Orbital Energy Levels

Resonant inelastic x-ray scattering is used to investigate the electronic origin of orbital polarization in nickelate heterostructures taking LaTiO_{3}-LaNiO_{3}-3×(LaAlO_{3}), a system with exceptionally large polarization, as a model system. We find that heterostructuring generates only minor changes in the Ni 3d orbital energy levels, contradicting the often-invoked picture in which changes in orbital energy levels generate orbital polarization. Instead, O K-edge x-ray absorption spectroscopy demonstrates that orbital polarization is caused by an anisotropic reconstruction of the oxygen ligand hole states. This provides an explanation for the limited success of theoretical predictions based on tuning orbital energy levels and implies that future theories should focus on anisotropic hybridization as the most effective means to drive large changes in electronic structure and realize novel emergent phenomena.

[Association between obstructive sleep apnea hypopnea syndrome and type 2 diabetes in Chinese:a Meta analysis]

Objective:The aim of this study is to assess the association between obstructive sleep apnea-hypopnea syndrome and type 2 diabetes (T2DM).Method:Databases such as Chinese Biomedical Literature Database,PubMed,Chinese Academic Journals full-text database,Wanfang Resource Database and Chongqing VIP have been searched to collect literatures about the relationship between OSAHS and type 2 diabetes.The papers and unpublished articles were also manually retrieved.Randomized controlled trial conformed to the condition were evaluated according to the standards of literature assessment,and the data has been extracted.The RevMan5.3 software was applied to carry out Meta-analysis.Result:Thirty studies are includedin the Meta-analysis.The fasting glucose content of OSAHS patients with T2DM is significantly higher than T2DM patients[WMD=1.01,95%CI(0.55,1.46), P<0.01];OSAHS with T2DM patients' apnea hypopnea index is significantly higher than OSAHS patients[WMD=3.78,95%CI(1.69,5.87),P<0.01];the fasting glucose content of OSAHS patients is also significantly higher than normal [WMD=1.16,95CI%(0.88,1.44),P<0.01];When stratified by rhe grades of OSAHS,we found fasting glucose content of all OSAHS patients is significantly higher than normal[WMD=1.09,95CI% (0.97,1.21),P<0.01];the funnel flot appeared to be symmetrical with little bias.Conclusion:The experimental results indicate that OSAHS is significantly related with T2DM ,and they may be the risk factorof each other.

Raman and fluorescence characteristics of resonant inelastic X-ray scattering from doped superconducting cuprates

Measurements of spin excitations are essential for an understanding of spin-mediated pairing for superconductivity; and resonant inelastic X-ray scattering (RIXS) provides a considerable opportunity to probe high-energy spin excitations. However, whether RIXS correctly measures the collective spin excitations of doped superconducting cuprates remains under debate. Here we demonstrate distinct Raman- and fluorescence-like RIXS excitations of Bi_1.5Pb_0.6Sr_1.54CaCu₂O_8+δ. Combining photon-energy and momentum dependent RIXS measurements with theoretical calculations using exact diagonalization provides conclusive evidence that the Raman-like RIXS excitations correspond to collective spin excitations, which are magnons in the undoped Mott insulators and evolve into paramagnons in doped superconducting compounds. In contrast, the fluorescence-like shifts are due primarily to the continuum of particle-hole excitations in the charge channel. Our results show that under the proper experimental conditions RIXS indeed can be used to probe paramagnons in doped high-T_c cuprate superconductors.

Analysis of Factors Affecting the Length of Hospital Stay for Patients with Diabetes

OBJECTIVE

The sharp rise in health expenditure of diabetes has become a huge financial and medical burden. A retrospective study was conducted to investigate the length of hospitalization for patients with diabetes and the control methods of the length of hospitalization, so as to improve the social and economic benefits of the hospital.

METHODS

Data of patients with diabetes who were admitted in the Guangdong Shantou Central Hospital from 2011 to 2013 were collected. Descriptive statistics and logistic regression analysis were used to explore the factors influencing the length of hospitalization for patients with diabetes such as sociological factors, disease factors, and clinical factors.

RESULTS

Univariate analysis results indicated that there were factors influencing the length of hospitalization for patients with diabetes, which were as follows: sociological factors including age (P<0.001), occupation (P=0.001), payment method (P<0.001), and the number of hospitalizations (P<0.001); disease factors including comorbidity (P<0.001) and initial glycated hemoglobin levels (P<0.001); and clinical factors including hospital-acquired infection (P<0.001), surgery (P<0.001), diagnoses within 3 days (P<0.001), department transfers (P=0.007), and treatment efficacy (P=0.003). In logistic regression analysis, 7 factors including surgery, hospital-acquired infections, comorbidities, age, payment methods, number of hospitalizations, and treatment efficacy had significant impacts on the length hospitalization for patients with diabetes.

CONCLUSION

The results of this study will be provided as a reference for a reasonable length of hospitalization of patients with diabetes.

Highly efficient beamline and spectrometer for inelastic soft X-ray scattering at high resolution

The design, construction and commissioning of a beamline and spectrometer for inelastic soft X-ray scattering at high resolution in a highly efficient system are presented. Based on the energy-compensation principle of grating dispersion, the design of the monochromator-spectrometer system greatly enhances the efficiency of measurement of inelastic soft X-rays scattering. Comprising two bendable gratings, the set-up effectively diminishes the defocus and coma aberrations. At commissioning, this system showed results of spin-flip, d-d and charge-transfer excitations of NiO. These results are consistent with published results but exhibit improved spectral resolution and increased efficiency of measurement. The best energy resolution of the set-up in terms of full width at half-maximum is 108 meV at an incident photon energy tuned about the Ni L3-edge.

Disease-related surgery in patients with distant metastatic breast cancer

INTRODUCTION

This study evaluates the frequency of and indications for disease-related surgical procedures in the palliative breast cancer (BC) situation.

PATIENTS & METHODS

Based on a cohort of women who were treated for newly diagnosed BC during a 20-year period (1990-2009), we analyzed 340 patients who developed distant metastatic disease (DMD) until 2011 and died (i.e. still ongoing palliative disease courses were not included).

RESULTS

One hundred and twenty-seven surgical procedures were performed in 100 patients (29.4% of all patients with metastatic disease). The most common site for surgery was breast (n = 60, 47.2%). The primary tumor was removed at first diagnosis of DMD in 43 patients (33.9%); sixteen operations (12.6%) were performed for local recurrence. In 37 patients, 50 surgical procedures (39.4%) were necessary to stabilize osseous structures due to metastases. Procedures were rarely performed on other common metastatic sites: lung: n = 1 (0.8%); liver: n = 1 (0.8%), brain: n = 4 (3.1%). When excluding surgery for primary breast tumors at initial diagnosis of DMD from analysis, 34 of 84 surgeries (40.4%) were performed in the first third of survival follow-up (i.e. period of metastatic disease survival); operations in the last two-thirds each totaled 29.8% (n = 25). The median survival after surgery was 16 months (range: 0.5-89 months).

CONCLUSIONS

In a cohort of BC patients who had primary or developed secondary DMD, nearly one third of the patients received disease-related surgical procedures during their palliative disease course. This high rate of operations shows that surgery has a clearly established role in the palliative therapy concept.

Crossover from incommensurate to commensurate magnetic orderings in CoCr(2)O(4)

The conical spin order of multiferroic CoCr(2)O(4) has been studied by a neutron diffraction to investigate its magnetic phase transitions at temperatures below 40 K. Magnetic order of a spiral spin component with an incommensurate propagation vector of (0.63, 0.63, 0) was observed at 26 K, while at 14.5 K, the incommensurate conical spin order showed a transition into the fixed commensurate propagation vector of (2/3,2/3,0). In addition, two satellite peaks with propagation vectors of (0.035, 0, 0) and (0, 0.035, 0) from the commensurate vector were observed. The widths of these peaks indicate a long-range magnetic order. This new magnetic configuration below 14.5 K may lead to a new model of multiferroic behavior differing from the well-known spin-current model for magnetic ferroelectricity.

Thermally or magnetically induced polarization reversal in the Multiferroic CoCr2O4

We report the unexpected evolution, with thermal and magnetic-field (H) variations, of the interrelation between the polarization P, magnetization M, and spiral wave vector Q in CoCr2O4, which has a ferrimagnetic conical-spiral magnetic order. For example, P suddenly jumps and changes its sign at the magnetic lock-in transition (T_{L}) with thermal variation, or with isothermal variation of H (without changing its direction) at T_{L}, which surprisingly occurs without change in spiral handedness (i.e., the sign of Q). The presence of multiple spiral sublattices may be behind this unusual behavior.

Metastatic involvement of the urinary tract in patients with advanced ovarian carcinoma: lessons from the autopsy for an interdisciplinary treatment approach

PURPOSE OF INVESTIGATION

Frequency and extent of metastases in urologic organs found at autopsy of ovarian carcinoma patients were evaluated.

METHODS

Autopsy reports from 170 patients who died of advanced ovarian carcinoma between 1975 and 2005 were studied. The distribution of abdominal metastatic sites with particular attention to the involvement of the urologic organs, and hydronephrosis was analyzed.

RESULTS

The distribution of metastatic sites was as follows: kidney (n = 6, 3.5%), urinary bladder (n = 38, 22.4%), and ureter (n = 20, 11.8%). In 36 patients, hydronephrosis was observed (21.2%); of these patients, 20 (55.6%) also had ureteral involvement. All patients with ureteral involvement had hydronephrosis.

CONCLUSION

Hydronephrosis in late stages of ovarian carcinoma, usually attributed to extrinsic compression of the ureter by an abdominal tumor, may also be explained by ureteral metastases. This fact must be considered in the clinical management of these patients, particularly in the restoration of luminal patency through an endoscopically placed internal ureteral stent.

Target and reality of adjuvant endocrine therapy in postmenopausal patients with invasive breast cancer

Previous research evaluating the use of adjuvant endocrine therapy among postmenopausal breast cancer patients showed with 15–50% wide ranges of non-adherence rates. We evaluated this issue by analysing an unselected study group comprising of 325 postmenopausal women, diagnosed from 1997 to 2003 with hormonal receptor-positive invasive breast cancer. The different clinical situations that led to the discontinuation of adjuvant endocrine therapy were clearly defined and differentiated: non-adherence was not simply the act of stopping medication, but rather the manifestation of an intentional behaviour of the patient. Of the 287 patients who initiated endocrine therapy, 191 (66.6%) fully completed this treatment. Thirty-one patients (10.8%) showed non-adherence to therapy. Patients who had follow-up with a general practitioner, rather than in an oncologic unit, were more likely to be non-adherent (P=0.0088). Of 25 patients who changed medication due to therapy-related adverse effects, 20 (80%) patients fully completed the therapy after drug change. In adjuvant endocrine therapy, a lowering of the non-adherence rate to 10.8%, the lowest reported in the literature, is realistic when patients are cared for by a specialised oncologic unit focusing on the individual needs of the patients.

Magnetic ground state and transition of a quantum multiferroic LiCu2O2

Based on resonant soft x-ray magnetic scattering, we report that LiCu2O2 exhibits a large interchain coupling which suppresses quantum fluctuations along spin chains, and a quasi-2D short-range magnetic order prevails at temperatures above the magnetic transition. These observations unravel the fact that the ground state of LiCu2O2 possesses long-range 2D-like incommensurate magnetic order rather than being a gapped spin liquid as expected from the nature of quantum spin-1/2 chains. In addition, the spin coupling along the c axis is found to be essential for inducing electric polarization.

Contaminants-induced oxidative damage on the carp Cyprinus carpio collected from the upper Yellow River, China

The Yellow River, the second largest river in China, is the most important resource of water supply in North China. In the last 40 years, even in the upper Yellow River, with the development of industry and agriculture, more and more contaminants have been discharged into this river and greatly polluted the water. Although a routine chemical component analysis has been performed, little is known about the real toxic effects of the polluted water on organisms at environmental level. To explore whether the pollutants induced oxidative stress and damage to aquatic organisms, malondialdehyde (MDA) level and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in hepatopancreas, kidney and intestine of the field-collected carp Cyprinus carpio from a mixed polluted (Lanzhou Region, LZR) and a relatively unpolluted (Liujiaxia Region, LJXR) sites of the upper Yellow River were measured. The results showed that when the values of LZR compared with those of LJXR, SOD and GST activities increased and GPx activity decreased significantly in all the three organs (P < 0.05-0.01); CAT activity decreased but MDA level increased significantly (P < 0.05-0.01) only in kidney and intestine. In conclusion, the results of this study suggest that the pollutants can induce obvious oxidative damage in the carp, and the SOD, GST and GPx might be better indicators for the oxidative damage in aquatic organisms.

Symmetry of multiferroicity in a frustrated magnet TbMn2O5

Based on measurements of soft-x-ray magnetic scattering and symmetry considerations, we demonstrate that the magnetoelectric effect in TbMn2O5 arises from an internal field determined by S-->q--> x S-->-q--> with S-->q--> being the magnetization at modulation vector q-->, whereas the magnetoelastic effect in the exchange energy governs the response to external electric fields. Our results set fundamental symmetry constraints on the microscopic mechanism of multiferroicity in frustrated magnets.

Charge-orbital ordering and Verwey transition in magnetite measured by resonant soft X-ray scattering

We report experimental evidence for the charge-orbital ordering in magnetite below the Verwey transition temperature T(V). Measurements of O K-edge resonant x-ray scattering on magnetite reveal that the O 2p states in the vicinity of the Fermi level exhibit a charge-orbital ordering along the c axis with a spatial periodicity of the doubled lattice parameter of the undistorted cubic phase. Such a charge-orbital ordering vanishes abruptly above T(V) and exhibits a thermal hysteresis, correlating closely with the Verwey transition in magnetite.

Orbital symmetry and electron correlation in NaxCoO2

Measurements of polarization-dependent soft x-ray absorption reveal that the electronic states determining the low-energy excitations of NaxCoO2 have predominantly a(1g) symmetry with significant O 2p character. In contrast to the prediction of band theory, doping-dependent O 1s x-ray absorption shows a large transfer of spectral weight, providing spectral evidence for strong electron correlations of the layered cobaltates. We also found that NaxCoO2 exhibits a charge-transfer electronic character rather than a Mott-Hubbard character.

Charge-orbital ordering and Verwey transition in magnetite

Local density approximation + Hubbard U (LDA + U) band structure calculations reveal that magnetite (Fe3O4) forms an insulating charge-orbital-ordered state below the Verwey transition temperature. The calculated charge ordering is in good agreement with that inferred from recent experiments. We found an associated t(2g) orbital ordering on the octahedral Fe2+ sublattice. Such an orbital ordering results primarily from the on-site Coulomb interaction. This finding unravels such fundamental issues about the Verwey transition as the mechanism for the charge ordering and for the formation of the insulating gap, as well as the nonobedience of the Anderson's criterion for the charge ordering.

Spin and orbital magnetic moments of Fe3O4

We present measurements of the spin and orbital magnetic moments of Fe3O4 by using SQUID and magnetic circular dichroism in soft x-ray absorption. The measurements show that Fe3O4 has a noninteger spin moment, in contrast to its predicted half-metallic feature. Fe3O4 also exhibits a large unquenched orbital moment. Calculations using the local density approximation including the Hubbard U method and the configuration interaction cluster-model suggest that strong correlations and spin-orbit interaction of the 3d electrons result in the noninteger spin and large orbital moments of Fe3O4.

Orbital ordering in La0.5Sr1.5MnO4 studied by soft X-ray linear dichroism

We found that the conventional model of orbital-ordering of 3x(2)-r(2)/3y(2)-r(2) type in the e(g) states of La0.5Sr1.5MnO4 is incompatible with measurements of linear dichroism in the Mn 2p-edge x-ray absorption, whereas these e(g) states exhibit predominantly cross-type orbital ordering of x(2)-z(2)/y(2)-z(2). LDA+U band-structure calculations reveal that such a cross-type orbital-ordering results from a combined effect of antiferromagnetic structure, Jahn-Teller distortion, and on-site Coulomb interactions.

[Effects of insulin on production of NO and NOS mRNA expression in bovine aortic endothelial cells]

AIM

In order to explore the regulation of the production of nitric oxide (NO) and the expression of nitric oxide synthase (NOS) gene in bovine aortic endothelial cells (BAEC) by insulin.

METHODS

The NO2- which is the production of NO in the culture medium was determined based on Griess reaction. Quantitative RT/PCR technique was performed to quantitate the levels of NOS mRNA in BAEC.

RESULTS

(1) Insulin neither affected BAEC proliferation, nor had cytotoxic effect. (2) Over a concentration range of 1-15 microg/ ml, insulin stimulation of BAEC resulted in a dose-dependent production of NO in the culture supernatants 2 hours later, with a maximum at 12 hours and this effect was completely blocked by L-NAME. (3) NOS mRNA was slightly greater in BAEC after exposed to insulin, but without statistical significance.

CONCLUSION

Since the endothelial cell proliferation and the expression of NOS mRNA was not affected with insulin, our data suggested that the insulin-induced NO production was mediated via the activation of NOS activity.

Osmotic stress-induced changes of sucrose metabolism in cultured sweet potato cells

The intra- and extracellular sugar contents, the activities of sucrose-metabolizing enzymes, and the metabolism of [U-(14)C] glucose in a pulse-chase experiment were compared between the normal and osmotically stressed (by 0.6 M sorbitol) sweet potato (Ipomoea batatas) suspension cells. The stress enhanced the levels of sucrose and sucrose phosphate synthase (SPS) activity. Northern blot analysis also showed that prolonged osmotic stress enhanced the SPS gene expression at the transcriptional level. Stressed cells also had higher activities of sucrose cleaving enzymes, such as alkaline invertase and sucrose synthase. The (14)C-sucrose isolated from normal and stressed cells had (14)C-fructose and (14)C-glucose ratios of 0.68 and 1, respectively. These data suggest the continual cycling of degradation and synthesis of sucrose in both types of cells. Among the enzymes used in constructing such futile cycling, besides invertase and SPS, sucrose synthase (SS) should be involved in normal cells, but not in stressed ones. It is apparent that the osmotic stress caused a significant change in the pattern of sucrose metabolism.

Nickel-catalyzed

Oxabenzonorbornadienes 1 and 2 and azabenzonorbornadiene 3 undergo [2+2] cycloaddition with alkynes (PhC triple bond Ph, PhC triple bond CMe, PhC triple bond CCO2Et, PhC triple bond CCH(OEt)2, and HC triple bond C(CH2)4Me) in the presence of [Ni(PPh3)2Cl2], PPh3, and Zn powder in toluene to afford the corresponding exo-cyclobutene derivatives 4a-e, 5a-e, and 6 in fair to excellent yields. Under similar conditions. EtCO2C triple bond CCO2Et does not react with 1 in toluene to give the [2+2] cycloaddition product, but in acetonitrile, the catalytic [2+2] cycloaddition proceeds and cycloadduct 4 f is isolated in 83% yield. At high temperature, these cyclobutene derivatives readily undergo ring expansion to yield the corresponding 8-membered carbocyclic dienes. Thus, flash vacuum pyrolysis of 4a, 4d, 4f, 6, and 14 at 500 degrees C affords dienes 13a-d and 15 in 70-96% yields. This interesting ring expansion may be viewed as the insertion of an alkyne moiety into the carbon-carbon double bond of a cyclic olefin resulting in the enlargement of the ring by two carbons. Compound 13a is readily deoxygenated by TiCl4 and Zn in THF to give a cyclooctatetraene derivative 16 in 89% yield.

Four classes of salicylate-induced tobacco genes

We have identified and characterized fragments of 15 salicylic acid (SA) early response genes. The kinetics of induction and response to cycloheximide (CHX) treatment allowed classification of genes into four groups. Classes I-III are characterized by immediate-early responses, showing increased accumulation of mRNA within 30 min of SA treatment. Moreover, CHX did not block induction of these genes, indicating that latent cellular factors mediate the SA response. Class IV genes were induced more slowly, but still within 2 to 3 h of SA treatment, and required protein synthesis for expression. Although identified in this study as SA-responsive genes, several could also be induced by other compounds. Two genes were characterized in more detail, including isolation of cDNA sequences and additional analysis of gene expression. Sequence analysis revealed that the class I gene, C18-1, is the previously identified ethylene response element binding protein 1 (EREBP1), an ethylene-induced transcription factor for basic pathogenesis-related (PR) genes, whereas the class III gene, G8-1, is a novel sequence. G8-1 was found to be strongly induced only by SA and its active analogs and was exquisitely sensitive to low SA concentrations. These and other genes were found to be activated at early times following tobacco mosaic virus infection of resistant tobacco genotypes.

[Effects of Viscum coloratum flavonoids on fast response action potentials of hearts]

The effects of the total flavonoids of Viscum coloratum (VCF) on the fast response action potentials (FAP) of canine Purkinje fibers and guinea pig ventricular papillary muscles were studied by glass-microelectrode technique. The effects of VCF on the ionic currents through cellular membrane were analysed with selective ion blockers (CsCl, verapamil, and TEA+), respectively. VCF (100 micrograms.ml-1) accelerated the repolarization of FAP and increased delta ERP/delta APD ratio, which were related to decreasing Isi and increasing Ix. It was suggested that the anti-tachyarrhythmic mechanism of VCF was attributed to prolonging ERP relatively and to abolishing reentrant excitation.

[A study of left ventricular function in normal persons and patients with old myocardial infarction with three dimensional echocardiography (3-DE)]

The accuracy of 3-DE in evaluating the volumes of left ventricule (LV) and volume changes in cardiac cycle was discussed. The LV volumes measured with 3-DE in porcine hearts is more closely to the real volumes directly measured (P > 0.05 r = 0.93). The EF value measured with radionuclide has higher correlation with that of 3-DE (r = 0.88) in patients. In a quantitative analysis of LV volume changes in cardiac cycles, we found that the decrease of EF in patients with old myocardial infarction (OMI) occurs mainly at the early stage and lasts to middle stage of systole in anterior myocardial infarction. Dysfunction of filling in OMI took place at the early and middle stages of diostole. Segmental shortening of LV was analysed quantitatively by percentage and pseudocolour mark. The reference values of 3DE in cardiac function were shown.

Epithelioid sarcoma of the penis

A rare case of penile epithelioid sarcoma in a 26-year-old white man is presented. The patient had a firm, slow growing, painless mass associated with penile deviation on erection, which was initially misdiagnosed as Peyronie's disease 5 years previously. With the onset of decreased urinary stream the lesion was biopsied, with a resultant diagnosis of epithelioid sarcoma. The patient underwent radical penectomy and perineal urethrostomy, and received 6,000 cGy. external beam radiotherapy postoperatively. Two years postoperatively the patient remained free of clinical disease. We review the pathophysiology, clinical characteristics and treatment of penile epithelioid sarcoma.

Adenosine triphosphate liposomes: encapsulation and distribution studies

Four methods for encapsulating adenosine triphosphate (ATP) in liposomes were evaluated. Optimum entrapment required emulsifying ATP with the lipids used to form the liposome membrane in a high-speed homogenizer followed by evaporating the organic solvent with vigorous stirring. Under these optimum conditions ATP entrapment was 38.9%; i.e., the dosage form contained 38.9 g of ATP per 100 g of lipid. The distribution of positively charged liposomes loaded with ATP was studied in dogs with experimentally induced myocardial infarction. Intravenous injection of positively charged ATP liposomes caused accumulation of ATP in myocardial infarct tissue. Myocardial infarct tissue has reduced blood flow; since positively charged liposomes accumulated in infarct tissue, liposomes may be a drug delivery system for this disease state.

[Factors affecting parameters of left ventricular diastolic function derived from Doppler echocardiography]

According to the data from left ventricular catheterization as well as M-mode and two-dimensional echocardiography in 36 patients, the influence of left ventricular diameter, systolic function, systolic and diastolic filling pressures on the parameters of left ventricular diastolic function derived from Doppler echocardiography was analysed. The results indicate: (1) the left ventricular end diastolic pressure, rapid filling wave pressure and the ratio of the both significantly affect the Doppler diastolic function parameters; (2) the decrease of the ratio of early-to-late diastolic mitral flow velocities (E/A) is only a manifestation of early stage of left ventricular diastolic dysfunction and the E/A ratio returns to normal (false improving) at advanced stage of left ventricular diastolic dysfunction.

[Influence of acute respiratory failure on plasma renin activity and plasma angiotensin II level in advanced chronic obstructive pulmonary disease and chronic cor pulmonale]

Plasma renin activity (PRA) and plasma angiotensin II (PAT II) level were determined with the method of radioimmunoassay in 55 patients with advanced chronic obstructive pulmonary disease (COPD) and chronic cor pulmonale (41 of them had respiratory failure) and 12 healthy aged persons. The results showed that PRA and PAT II levels were significantly elevated in the presence of such factors as severe hypoxia and hypercapnia (PaO2 less than or equal to 45 mmHg, mean 40 mmHg, PaCO2 greater than or equal to 65 mmHg), right heart failure, acidosis, hyponatremia and hypochloremia. It is shown that the prognosis would be poor when the patient's PRA level is significantly elevated.

Validation of a coronary prognostic index for the Chinese--a tale of three cities

In order to confirm the efficacy of a new coronary prognostic index for the prediction of mortality of acute myocardial infarction in the Chinese in general, this index was applied to 886 patients from six general hospitals in Hong Kong (435 patients), Guangzhou (212 patients) and Shanghai (239 patients), respectively. They could be successfully stratified into seven clinical subsets with stepwise increasing mortality. The overall mortality tallied with that predicted by the original coronary prognostic index. The efficacy of this prognostic index for the prediction of mortality from acute myocardial infarction among the Chinese is verified and its application in the objective assessment of patients with acute myocardial infarction is recommended.

[Catheter ablation in eight patients with Wolff-Parkinson-White syndrome]

After a follow-up study of 13-39 months, the clinical effect of catheter ablation in 8 patients with WPW syndrome and recurrence of SVT was reported. Five cases of left free-wall accessory pathway underwent catheter ablation attempts by direct current shocks delivered in coronary sinus. 3 of them were free from SVT without any medications after ablation, 1 case was improved. The other one was unsuccessful. Catheter ablation was attempted by delivery of shocks at coronary sinus orifice in 3 patients with posteroseptal accessory pathway. Arrhythmias were controlled without the need of drug therapy in 2 cases and the clinical symptoms were relieved in 1 case after shocks. We consider that the catheter ablation attempted to block the conduction of left free-wall and posteroseptal accessory pathway induces much less damages than surgical ablation and offers the advantages of shorter hospitalization, lower cost and a much shorter convalescence. The authors stated that it is a viable alternative to surgical ablation for those patients who are not responsive or allergic to drugs or those who are not willing to take a life-long period of medications. Some concerns for increasing the success rate and reducing the complications of ablation were also discussed.

Low-cost frequency-stabilized CO(2) laser using 4.3-microm saturated fluorescence

A frequency-stabilized CO(2) laser using the saturated fluorescence technique was constructed. Stainless-steel rods were used to support the cavity, and a thermoelectrically cooled PbSe detector monitored the 4.3-microm fluorescence from a low-pressure CO(2) absorption cell. Stabilization of the CO(2) laser at the center of the saturation dip was achieved with the absorption cell inside or outside the laser cavity. The frequency stability is estimated to be better than 3.5 x 10(-9).