Therapeutic effects of coptisine derivative EHLJ7 on colorectal cancer by inhibiting PI3K/AKT pathway

Colorectal cancer (CRC) is the third most common cancer in the world with high mortality rate. EHLJ7 is a quaternary coptisine derivative synthesized by our institute. In this study, the role and mechanism of EHLJ7 on CRC are further elucidated. Using target fishing, colon cancer-associated target screening and molecular docking analysis, PI3K/AKT pathway was selected for the target of EHLJ7 at CRC. Results of Flow cytometry, wound healing assay and transwell migration assay confirmed that EHLJ7 could inhibit migration and apoptosis of colon cancer cells by specifically inhibiting PI3K/AKT pathway in vitro. Xenograft tumor models and a newly established azoxymethane (AOM)/dextran sulfate sodium (DSS)/Peptostreptococcus anaerobiu (P.anaerobius)-induced CRC mouse model are applied to access the anti-cancer action and mechanism of EHLJ7 using western-blot, immunohistochemistry and analysis of exosomes. The key findings in this study are listed as follows: (1) EHLJ7 exerts superior anti-tumor effect with good safety on Xenograft tumor model and CRC model; (2) EHLJ7 exerted its anti-CRC effect by specifically inhibiting PI3K/AKT pathway and apoptosis in vivo and in vitro. In summary, we demonstrated that EHLJ7 exerts therapeutic effect against CRC by PI3K/AKT pathway, which made it possible as a potentially effective compound for the treatment of CRC.

Beamline simulations using monochromators with high d-spacing crystals

Monochromators for synchrotron radiation beamlines typically use perfect crystals for the hard X-ray regime and gratings for soft X-rays. There is an intermediate range, typically 1-3 keV (tender X-rays), which common perfect crystals have difficulties covering and gratings have low efficiency, although some less common crystals with high d-spacing could be suitable. To evaluate the suitability of these crystals for a particular beamline, it is useful to evaluate the crystals' performance using tools such as ray-tracing. However, simulations for double-crystal monochromators are only available for the most used crystals such as Si, Ge or diamond. Here, an upgrade of the SHADOW ray-tracing code and complementary tools in the OASYS suite are presented to simulate high d-spacing crystals with arbitrary, and sometimes complex, structures such as beryl, YB₆₆, muscovite, etc. Isotropic and anisotropic temperature factors are also considered. The YB₆₆ crystal with 1936 atomic sites in the unit cell is simulated, and its applicability for tender X-ray monochromators is discussed in the context of new low-emittance storage rings.

Unravelling strong electronic interlayer and intralayer correlations in a transition metal dichalcogenide

Electronic correlations play important roles in driving exotic phenomena in condensed matter physics. They determine low-energy properties through high-energy bands well-beyond optics. Great effort has been made to understand low-energy excitations such as low-energy excitons in transition metal dichalcogenides (TMDCs), however their high-energy bands and interlayer correlation remain mysteries. Herewith, by measuring temperature- and polarization-dependent complex dielectric and loss functions of bulk molybdenum disulphide from near-infrared to soft X-ray, supported with theoretical calculations, we discover unconventional soft X-ray correlated-plasmons with low-loss, and electronic transitions that reduce dimensionality and increase correlations, accompanied with significantly modified low-energy excitons. At room temperature, interlayer electronic correlations, together with the intralayer correlations in the c-axis, are surprisingly strong, yielding a three-dimensional-like system. Upon cooling, wide-range spectral-weight transfer occurs across a few tens of eV and in-plane p-d hybridizations become enhanced, revealing strong Coulomb correlations and electronic anisotropy, yielding a two-dimensional-like system. Our result shows the importance of strong electronic, interlayer and intralayer correlations in determining electronic structure and opens up applications of utilizing TMDCs on plasmonic nanolithrography.

[Preoperative diagnostic value of 99mTc- MIBI SPECT/CT imaging combined with semiquantitative analysis in hyperparathyroidism and factors affecting its efficacy]

OBJECTIVE

To evaluate the diagnostic efficacy of technetium-99m methoxyisobutylisonitrile single photon emission/ computed tomography (^99mTc- MIBI SPECT/CT), ^99mTc- MIBI double- phase scintigraphy (DPS) DPS and ultrasound (US) in preoperative localization of hyperparathyroidism (HPT) and explore the factors affecting the diagnostic efficacy of ^99mTc-MIBI SPECT/CT.

METHODS

We retrospectively analyzed the data of 104 patients with HPT undergoing surgical resection between January, 2015 and July, 2019. Preoperative ^99mTc-MIBI imaging was performed in all the patients, and 82 patients also received US examination preoperatively. Semi-quantitative analysis was used to draw the region of interest and calculate the lesion/ ipsilateral deltoid muscle (T/NT) uptake ratio. The sensitivity and detection performance of ^99mTc-MIBI SPECT/CT, DPS and US in the diagnosis of HPT patients were compared, and the correlations of the T/NT ratios of parathyroid adenoma (PA) and parathyroid hyperplasia (PH) with the expression levels of COX-2 and Bcl-2 were analyzed.

RESULTS

The diagnostic sensitivity of ^99mTc- MIBI SPECT/CT, DPS and US for HPT was 95.19% (99/104), 91.3% (95/104) and 81.71% (67/82), respectively, demonstrating a significantly higher diagnostic sensitivity of ^99mTc-MIBI SPECT/CT than US (χ²=9.59, P=0.008). For PH lesions, ^99mTc-MIBI SPECT/CT had the highest diagnostic sensitivity, followed by DPS and then by US (P < 0.05), but their sensitivity did not differ significantly for PA (P>0.05). The T/NT ratio in fatty hyperplastic glands was significantly lower than that in fat-free hyperplastic glands (P=0.009). In PA, Bcl-2 expression was significantly lower in false negative lesions than in true positive lesions (P=0.046), but Cox-2 expression did not show such a difference (P>0.05). In PH lesions, the expressions of Bcl-2 and Cox- 2 did not differ significantly between false negative than true positive lesions (P>0.05).

CONCLUSIONS

^99mTc-MIBI SPECT/CT has a high sensitivity for HPT localization, and the T/NT ratio is positively correlated with the lesion volume. An increased expression of Bcl-2 in PA lesions and a decreased cell fat content in PH lesions can facilitate the detection of HPT glands by ^99mTc-MIBI SPECT/CT.

[Analysis of brain perfusion single-photon emission tomography images using an easy Zscore imaging system for early diagnosis of Alzheimer's disease]

OBJECTIVE

To analyze single-photon emission tomography (SPECT) images of cerebral blood flow perfusion using an easy Z-score imaging system (eZIS) and explore the value of SPECT and eZIS in early diagnosis of Alzheimer's disease (AD).

METHODS

We retrospectively analyzed the clinical data of 71 subjects undergoing brain perfusion SPECT examination in our department from September, 2018 to September, 2020 and identified 31 eligible subjects for this study. Among these subjects, according to the NIA-AA criteria (2011 edition), 12 were diagnosed with mild cognitive impairment due to AD (MCI) and 11 with AD dementia stage (AD); 8 elderly subjects were healthy without cognitive impairment (NC). All these subjects underwent brain perfusion SPECT, and eZIS-assisted analysis was used to obtain the index values (severity, range and ratio). The differences in the severity, extent and ratio among the 3 groups were compared, and the diagnostic efficacy of single and joint analysis of the 3 indexes for early AD was analyzed.

RESULTS

There was no significant difference in gender, age and education level among the 3 groups (P>0.05). Compared with those in NC group, the Mini Mental State Examination Scale (MMSE) scores were significantly lowered in AD group and MCI group; the MMSE score was significantly lower in AD group than in MCI group (P < 0.05). The patients with AD had significantly greater disease severity and extent than those with MCI group; the severity, range and ratio in both AD group and MCI group were significantly higher than those of NC group, but the ratio did not differ significantly between AD group and MCI group (P>0.05). In single index analysis, severity had the highest diagnostic performance (AUC=0.911) and sensitivity (87.0%); the diagnostic performance and sensitivity of joint analysis were better than those of single analysis, and joint analysis of range and ratio showed high diagnostic performance (AUC=0.948) and sensitivity (87.0%).

CONCLUSION

The analysis of brain perfusion SPECT using an eZIS program can be useful for early diagnosis of AD.

Antioxidative stress of oral administration of tea extract granule in chickens

The present study was to evaluate antioxidative effect of tea extract granule (TEG) on oxidative stress induced by cyclophosphamide (Cy) in chickens. In experiment 1, chickens were randomly divided into 5 groups with 10 birds in each. Groups 3 to 5 were orally administered TEG in drinking water for 7 D at doses of 20, 40, and 80 mg/kg body weight, respectively. After that, groups 2 to 5 received intramuscular injection of Cy (100 mg/kg BW) for 3 D. Group 1 was not treated as a control. In experiment 2, chickens were grouped in the same way as in experiment 1. Groups 2 to 5 received intramuscular injection of Cy (100 mg/kg BW) for 3 D. After that, groups 3 to 5 were orally administered TEG in drinking water for 7 D at doses of 20, 40, and 80 mg/kg BW, respectively. Results showed that Cy injection induced significantly decreased body weight and oxidative stress. Oral administration of TEG before or after Cy injection increased body weight, the thymus, bursa, and spleen indices, total antioxidant capacity, and the levels of glutathione; elevated the activity of superoxide dismutase, catalase, and glutathione peroxidase; as well as decreased the protein carbonyl content, lipid peroxide, and malondialdehyde. In addition, TEG administration reduced intracellular reactive oxygen species. Therefore, TEG could be a promising agent against oxidative stress in the poultry industry.

Combined adjuvant effect of ginseng stem-leaf saponins and selenium on immune responses to a live bivalent vaccine of Newcastle disease virus and infectious bronchitis virus in chickens

Vaccination with a live bivalent vaccine of Newcastle disease virus (NDV) and infectious bronchitis virus (IBV) is a routine practice in poultry industry in China. This study was designed to evaluate ginseng stem-leaf saponins (GSLS) in combination with selenium (Se) for their adjuvant effect on the immune response to vaccination against NDV and IBV in chickens. A live bivalent vaccine of NDV and IBV was diluted in saline solution containing GSLS or Se or both and used to immunize chickens via a intraocular-and-intranasal route. Results showed that GSLS promoted significantly higher NDV- and IBV-specific antibody responses with the highest antibody response detected in GSLS-Se group. The increased antibody was capable of neutralizing NDV and IBV. In addition, GSLS-Se enhanced lymphocyte proliferation and production of IFN-γ and IL-4. More importantly GSLS-Se was found to promote early production and prolong the duration of the antibody responses. In order to improve the efficacy of vaccination in chicken flocks, the diluent containing GSLS-Se deserves further studies to evaluate its effect on other chicken vaccines.

Comparison of the gut microbiota composition between the wild and captive Tibetan wild ass (Equus kiang)

Aims

The gut microbiota has a great effect on the health and nutrition of the host. Manipulation of the intestinal microbiota may improve animal health and growth performance. The objectives of our study were to characterize the faecal microbiota between wild and captive Tibetan wild asses and discuss the differences and their reasons.

Methods and Results

Through high‐throughput sequencing of the 16S rRNA V4‐V5 region, we studied the gut microbiota composition and structure of Tibetan wild asses in winter, and analysed the differences between wild and captive groups. The results showed that the most common bacterial phylum in Tibetan wild ass faeces samples was Bacteroidetes, while the phylum Firmicutes was dominant in captive Tibetan wild ass faecal samples. The relative abundance of Firmicutes, Tenericutes and Spirochaetes were significantly higher (P < 0·01) than in the wild groups.

Conclusions

Captivity reduces intestinal microbial diversity, evenness and operational taxonomic unit number due to the consumption of industrial food, therefore, increasing the risk of disease prevalence and affecting the health of wildlife.

Significance and Impact of the Study

We studied the effect of the captive environment on intestinal micro‐organisms. This article provides a theoretical basis for the ex‐situ conservation of wild animals in the future.

Ginsenoside Rg1 enhanced immune responses to infectious bursal disease vaccine in chickens with oxidative stress induced by cyclophosphamide

This study was designed to evaluate the effect of oral administration of ginsenoside Rg1 on oxidative stress induced by cyclophosphamide in chickens. Ninety-six chickens were randomly divided into 4 groups, each consisting of 24 birds. Groups 2 and 3 received intramuscular injection of cyclophosphamide at 100 mg/kg body weight for 3 d to induce oxidative stress and immune suppression. Groups 1 and 4 were injected with saline in the same way as groups 2 and 3. Then chickens in group 3 were orally administrated Rg1 of 1 mg/kg body weight in drinking water for 7 d. After that, groups 1 to 3 were orally vaccinated with attenuated infectious bursal disease vaccine (Strain B87). Blood samples were collected for determination of infectious bursal disease virus-specific antibodies, cytokines, and oxidative parameters. Splenocytes were prepared for lymphocyte proliferation assay. The results showed that oral administration of ginsenoside Rg1 significantly enhanced specific antibody, IFN-γ, and IL-6 responses, and lymphocyte proliferation induced by concanavalin A and lipopolysaccharide in chickens injected with cyclophosphamide. Antioxidant activity of ginsenoside Rg1 was also observed in chickens by increased total antioxidant capacity, total superoxide dismutase, catalase, glutathione peroxidase, glutathione, ascorbic acid, and α-tocopherol, as well as decreased malondialdehyde and protein carbonyl. Therefore, oral administration of Rg1 was shown to improve the immune responses to infectious bursal disease vaccine in chickens suffering from oxidative stress.

Oral administration of tea saponins to relive oxidative stress and immune suppression in chickens

The present study was designed to evaluate the effects of tea saponins on oxidative stress induced by cyclophosphamide in chickens. One hundred twenty chickens were randomly divided into 5 groups. Groups 3 to 4 received intramuscular injection of cyclophosphamide to induce oxidative stress and immunosuppression. After that, groups 2 and 4 were orally administered tea saponins in drinking water for 7 d. Then, groups 1 to 4 were immunized with a live, bivalent vaccine of Newcastle disease virus and infectious bronchitis virus. Blood samples were collected for analysis of oxidative parameters and specific antibody titers, and splenocytes were prepared for lymphocyte proliferative assay. The results showed that administration of tea saponins significantly increased total antioxidant capacity, total superoxide dismutase, catalase, glutathione peroxidase, glutathione, ascorbic acid, and α-tocopherol, and decreased malondialdehyde and protein carbonyl. Enhanced immune responses, such as lymphocyte proliferation induced by concanavalin A and lipopolysaccharides, and serum Newcastle disease virus- and infectious bronchitis virus-specific antibodies were also observed in chickens injected with or without cyclophosphamide. In addition, no side effects were found in chickens throughout the study. Therefore, tea saponins may be a potential agent to improve imunosuppression induced by oxidative stress in chickens.

Risk factors for mortality in patients with anti-NMDA receptor encephalitis

OBJECTIVE

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a severe autoimmune disorder with a mortality of 5%-7%, but few studies have focused on the predictors of death in this disease. In this study, we aim to investigate predictors and causes of death in patients with anti-NMDAR encephalitis.

METHODS

In this cohort study, patients with anti-NMDAR encephalitis were enrolled at the West China Hospital of Sichuan University between June 2011 and October 2015. The outcomes of patients were evaluated by long-term follow-up. Cox regression analysis was used to assess the association between potential predictors and death.

RESULTS

Altogether 96 patients were included in this study, and 11 died after median 24.5 (7-57) months of follow-up. The mortality of anti-NMDAR encephalitis was 11.46%. Multivariate analysis results showed that Glasgow Coma Scale (GCS) score ≤8 at admission (HR=15.917, 95% CI=1.729-146.562; P=.015), the number of complications (HR=7.772, 95% CI=1.944-31.072; P=.004), and admission to an intensive care unit (HR=70.158, 95% CI=2.395-2055.459; P=.014) were significantly associated with increased risk of mortality. Twelve patients received second-line immunotherapy, and the cohort was relatively under-treated compared with other studies. The main causes of death were severe pneumonia, multiple organ dysfunction syndrome, and refractory status epilepticus.

CONCLUSION

GCS score ≤8 at admission, number of complications, and admission to an intensive care unit are predictors of death. Management of complications may improve the prognosis of anti-NMDAR encephalitis.

The antisense expression of

Although phosphoenolpyruvate carboxylases (PEPCs) are reported to be involved in fatty acid accumulation, nitrogen assimilation, and salt and drought stresses, knowledge regarding PEPC gene functions is still limited, particularly in peanuts (Arachis hypogaea L.). In this study, the antisense expression of the peanut PEPC isoform 1 (AhPEPC1) gene increased the lipid content by 5.7%–10.3%. This indicated that AhPEPC1 might be related to plant lipid accumulation. The transgenic plants underwent more root elongation than the wild-type under salinity stress. Additionally, the specific down regulation of the AhPEPC1 gene improved the salt tolerance in peanuts. This is the first report on the role of PEPC in lipid accumulation and salt tolerance in peanuts.

Learning Chronobiology by Improving Wikipedia

Although chronobiology is of growing interest to scientists, physicians, and the general public, access to recent discoveries and historical perspectives is limited. Wikipedia is an online, user-written encyclopedia that could enhance public access to current understanding in chronobiology. However, Wikipedia is lacking important information and is not universally trusted. Here, 46 students in a university course edited Wikipedia to enhance public access to important discoveries in chronobiology. Students worked for an average of 9 h each to evaluate the primary literature and available Wikipedia information, nominated sites for editing, and, after voting, edited the 15 Wikipedia pages they determined to be highest priorities. This assignment ( http://www.nslc.wustl.edu/courses/Bio4030/wikipedia_project.html ) was easy to implement, required relatively short time commitments from the professor and students, and had measurable impacts on Wikipedia and the students. Students created 3 new Wikipedia sites, edited 12 additional sites, and cited 347 peer-reviewed articles. The targeted sites all became top hits in online search engines. Because their writing was and will be read by a worldwide audience, students found the experience rewarding. Students reported significantly increased comfort with reading, critiquing, and summarizing primary literature and benefited from seeing their work edited by other scientists and editors of Wikipedia. We conclude that, in a short project, students can assist in making chronobiology widely accessible and learn from the editorial process.

Abstract P3-14-20: Phase 1 Dose-Escalation Study of the Investigational HER2/EGFR Inhibitor TAK-285 in Patients with Advanced Cancer

Background and Objectives: TAK-285 is a novel, orally active, dual HER2/EGFR inhibitor. Nonclinical data show that TAK-285 has high selectivity and specificity for binding to HER family kinases, and has demonstrated anti-tumor activity in a BT-474 mouse xenograft model of breast cancer. Nonclinical data also indicate that TAK-285 is not a substrate for the efflux transporters P-gp and BCRP and penetrates an intact blood-brain barrier in rats. This phase 1 dose-escalation study in patients with advanced cancer aimed to determine the safety and pharmacokinetic (PK) profile.

Methods: Adults had advanced histologically confirmed non-hematologic malignancies, life expectancy &gt;12 weeks, adequate bone marrow, liver and renal function, ECOG PS 0-2, and were refractory to other treatments. Oral TAK-285 was escalated from 50 to 500 mg QD or BID for 21 or 28 consecutive days of a 28-day cycle until disease progression or unacceptable toxicity was observed.

Results: At the data cut-off of 04/23/10, the dose-escalation portion was complete, and the RP2D expansion cohort is ongoing. Preliminary data from the dose-escalation cohorts are reported. 43 patients (median age 60 years [43-76]) were enrolled: 30% ≥65 years, 51% female, and 86% white. Dose levels were 50 mg QD (N=4), 50 mg BID (N=7), and 75 mg BID (N=6) on d 1-21; and 150 mg (N=6), 225 mg (N=4), 325 mg (N=3), 400 mg (N=6), and 500 mg (N=7) BID on d 1-28. Median duration of exposure across all cohorts was 52 days (3-267). Four patients experienced a DLT in Cycle 1: 1 patient (50 mg BID) had Grade 3 pancreatitis; 1 patient (150 mg BID) had Grade 3 chest pain and Grade 3 hypoxia; 1 patient (500 mg BID) had Grade 3 increased ALT; and 1 patient (500 mg BID) had Grade 3 diarrhoea and Grade 3 hypokalaemia. The MTD was 400 mg BID d 1-28. 30 patients (70%) discontinued TAK-285, primarily due to disease progression (n=19, 44%) or an AE (n=9, 21%). Most frequent AEs were fatigue (37%), diarrhoea (35%), nausea (26%), anorexia (21%), vomiting (16%), and elevated AST (16%). 58% of patients had a drug-related AE; the most frequent were diarrhoea (21%), fatigue (19%), and rash (includes rash, rash maculo-papular and rash macular; 12%). 35% of patients had a grade 3/4 AE; the most common were hypokalaemia (7%), ileus, abdominal pain, and hypoxia (5% each). Grade 3/4 AEs related to TAK-285 were the DLTs in Cycle 1 and Grade 4 rhabdomyolysis in 1 patient (400 mg BID, d 1-28) in Cycle 3. 42% of patients experienced a serious AE (SAE); the only SAE seen in &gt;1 patient was ileus (n=2). 4 (9%) patients had fatal AEs; none were considered related to TAK-285. Absorption was fast: plasma concentrations peaked 2-3 hours post-dose. Steady-state plasma exposures increased with dose in a greater than dose-proportional manner, with PK steady-state achieved by Day 8. Accumulation was noted with BID dosing (mean accumulation ratio, 2.4 at MTD); there was moderate fluctuation in plasma concentrations over the steady-state dosing interval (mean Cmax:Cmin ratio, 2.4 at MTD).

Conclusions: The MTD for TAK-285 was 400 mg BID d 1-28. The RP2D cohort is ongoing and includes CSF collection to assess the CNS distribution of TAK-285. Updated safety as well as efficacy data for the dose escalation cohorts will be presented.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-14-20.

Morphology effectively controls singlet-triplet exciton relaxation and charge transport in organic semiconductors

We present a comparative study of ultrafast photoconversion dynamics in tetracene (Tc) and pentacene (Pc) single crystals and Pc films using optical pump-probe spectroscopy. Photoinduced absorption in Tc and Pc crystals is activated and temperature-independent, respectively, demonstrating dominant singlet-triplet exciton fission. In Pc films (as well as C60-doped films) this decay channel is suppressed by electron trapping. These results demonstrate the central role of crystallinity and purity in photogeneration processes and will constrain the design of future photovoltaic devices.

Intercomparison of measurement techniques for black or elemental carbon under urban background conditions in wintertime: influence of biomass combustion

A generally accepted method to measure black carbon (BC) or elemental carbon (EC) still does not exist. An earlier study in the Vienna area comparing practically all measurement methods in use in Europe gave comparable BC and EC concentrations under summer conditions (Hitzenberger et al., 2006a). Under summer conditions, Diesel traffic is the major source for EC or BC in Vienna. Under winter conditions, space heating (also with biomass as fuel) is another important source (Caseiro et al., 2007). The present study compares the response of thermal methods (a modified Cachier method, Cachier et al., 1989; a thermal-optical method, Schmid et al., 2001; and two thermal-optical (TOT) methods using Sunset instruments, Birch and Cary, 1996 and Schauer et al., 2003) and optical methods (a light transmission method, Hansen et al., 1984; the integrating sphere method, Hitzenberger et al., 1996; and the multiangle absorption photometer MAAP, Petzold and Schönlinner, 2004). Significant differences were found between the TOT methods on the one hand and all other methods on the other. The TOT methods yielded EC concentrations that were lower by 44 and 17% than the average of all measured concentrations (including the TOT data). The largest discrepancy was found when the contribution of brown carbon (measured with the integrating sphere method) was largest.

Determination of isoprene and alpha-/beta-pinene oxidation products in boreal forest aerosols from Hyytiälä, Finland: diel variations and possible link with particle formation events

Biogenic volatile organic compounds (VOCs), such as isoprene and alpha-/beta-pinene, are photo-oxidized in the atmosphere to non-volatile species resulting in secondary organic aerosol (SOA). The goal of this study was to examine time trends and diel variations of oxidation products of isoprene and alpha-/beta-pinene in order to investigate whether they are linked with meteorological parameters or trace gases. Separate day-night aerosol samples (PM(1)) were collected in a Scots pine dominated forest in southern Finland during 28 July-11 August 2005 and analyzed with gas chromatography/mass spectrometry (GC/MS). In addition, inorganic trace gases (SO(2), CO, NO(x), and O(3)), meteorological parameters, and the particle number concentration were monitored. The median total concentration of terpenoic acids (i.e., pinic acid, norpinic acid, and two novel compounds, 3-hydroxyglutaric acid and 2-hydroxy-4-isopropyladipic acid) was 65 ng m(-3), while that of isoprene oxidation products (i.e., 2-methyltetrols and C(5) alkene triols) was 17.2 ng m(-3). The 2-methyltetrols exhibited day/night variations with maxima during day-time, while alpha-/beta-pinene oxidation products did not show any diel variation. The sampling period was marked by a relatively high condensation sink, caused by pre-existing aerosol particles, and no nucleation events. In general, the concentration trends of the SOA compounds reflected those of the inorganic trace gases, meteorological parameters, and condensation sink. Both the isoprene and alpha-/beta-pinene SOA products were strongly influenced by SO(2), which is consistent with earlier reports that acidity plays a role in SOA formation. The results support previous proposals that oxygenated VOCs contribute to particle growth processes above boreal forest.

Landau quantization effects in the charge-density-wave system (Per)2M(mnt)2 (where M = Au and Pt)

A finite transfer integral t(a) orthogonal to the conducting chains of a highly one-dimensional metal gives rise to empty and filled bands that simulate an indirect-gap semiconductor upon formation of a charge-density wave (CDW). In contrast to semiconductors such as Ge and Si with band gaps approximately 1 eV, the CDW system possesses an indirect gap with a greatly reduced energy scale, enabling moderate laboratory magnetic fields to have a major effect. The consequent variation of the thermodynamic gap with magnetic field due to Zeeman splitting and Landau quantization enables the electronic band structure parameters (transfer integrals, Fermi velocity) to be determined accurately. These parameters reveal the orbital quantization limit to be reached at approximately 20 T in (Per)2M(mnt)(2) salts, making them highly unlikely candidates for a recently proposed cascade of field-induced CDW states.

Amorphouslike density of gap states in single-crystal pentacene

We show that optical and electrical measurements on pentacene single crystals can be used to extract the density of states in the highest occupied molecular orbital-lowest unoccupied molecular orbital band gap. It is found that these highly purified crystals possess band tails broader than those typically observed in inorganic amorphous solids. Results on field-effect transistors fabricated from similar crystals imply that the gap state density is much larger within 5-10 nm of the gate dielectric. Thus, organic thin-film transistors for such applications as flexible displays might be significantly improved by reducing these defects.

Charge-density waves survive the Pauli paramagnetic limit

Measurements of the resistance of single crystals of (Per)2Au(mnt)2 have been made at magnetic fields B of up to 45 T, exceeding the anticipated Pauli paramagnetic limit of Bp approximately 37 T. The continued presence of nonlinear charge-density wave electrodynamics at B> or =37 T establishes the survival of the charge-density wave state above this limit, and the probable emergence of an inhomogeneous phase analogous to that anticipated to occur in superconductors.

Bias-dependent generation and quenching of defects in pentacene

We describe a defect generation phenomenon that is new to organic semiconductors. A defect in pentacene single crystals can be created by bias-stress and persists at room temperature for an hour in the dark but only seconds with 420 nm illumination. The defect gives rise to a hole trap at Ev+0.38 eV and causes metastable transport effects at room temperature. Creation and decay rates of the hole trap have a 0.67 eV activation energy with a small (10(8) s(-1)) prefactor, suggesting that atomic motion plays a key role in the generation and quenching process.

Magneto-opto-electronic bistability in a phenalenyl-based neutral radical

A new organic molecular conductor, based on a spiro-biphenalenyl neutral radical, simultaneously exhibits bistability in three physical channels: electrical, optical, and magnetic. In the paramagnetic state, the unpaired electrons are located in the exterior phenalenyl units of the dimer, whereas in the diamagnetic state the electrons migrate to the interior phenalenyl units and spin pair as a pi-dimer. Against all expectations, the conductivity increases by two orders of magnitude in the diamagnetic state, and the band gap decreases. This type of multifunctional material has the potential to be used as the basis for new types of electronic devices, where multiple physical channels are used for writing, reading, and transferring information.

Down-regulation of regulatory proteins for differentiation and proliferation in murine fetal hypoplastic lungs: altered mesenchymal-epithelial interactions

We compared proliferation (growth) and differentiation (development) related proteins in normal and hypoplastic fetal murine lungs. The hypoplastic lungs were created in CD-1 fetal mice by nitrofen exposure (25 mg per pregnant mouse given intragastrically on gestational day 8 [Gd8]), as published earlier. The lungs were harvested at Gd14, 16, 19 and from neonates. Immunoblot analyses were carried out for transcription factors (oncogenic proteins, nuclear receptor, and transmembrane receptor proteins) in severely hypoplastic murine fetal lungs with coexistent diaphragmatic hernia, and results were compared with those derived from normal lungs of equivalent age. These proteins have proposed roles in the regulation of proliferation and differentiation processes of fetal lungs. We have shown that the product of the oncogene c-myc was reduced in hypoplastic lungs at all stages of gestation, whereas c-Fos protein levels were variable. These proteins are known to regulate transcription of various developmental proteins, such as those responsible for proliferation and differentiation. Further, the nuclear transcription factors thyroid transcription factor-1 (TITF-1) and glucocorticoid receptor (GR) were reduced, and thyroid hormone receptor (TR) and retinoic acid receptors (RARs) were inhibited in severely hypoplastic lungs compared to normal lungs of equivalent gestational stage, except in neonatal lungs, where signals for RARs were seen. TITF-1 is known to localize in bronchial epithelial cells in developing lungs. It is restricted to type II pneumocytes with gestational development in the normal lungs and regulates surfactant proteins. Earlier, we have reported that surfactant proteins are reduced in hypoplastic lungs. In the current study, reduced GR and TITF-1 proteins may play a role in reducing surfactant proteins in the hypoplastic lungs. The significant inhibition in TR and RARalpha in the severely hypoplastic lungs reflects on affected epithelial cell maturation and alveolar formation, respectively. Altered RARbeta levels correlate with affected lung growth and branching morphogenesis of nitrofen-exposed lungs. A transmembrane receptor protein EGFR was reduced in hypoplastic lungs, suggesting the involvement of altered mesenchymal-epithelial signal transduction pathways. We conclude (1) Our data suggest altered levels of various nuclear transcription factors in the murine fetal hypoplastic lungs; (2) Reduced levels TITF-1 protein in hypoplastic lungs may have caused the functional immaturity of distal lung, immature airways and thus may affect overall differentiation of lungs. These results correlated with low levels of surfactant proteins in these lungs; (3) TR and RAR inhibition indicate their roles through reduced or retarded proliferation and differentiation processes in the severely hypoplastic lungs; (4) GR down-regulation in developing fetal murine hypoplastic lungs indicate delayed development, and GR up-regulation in affected neonates may be induced by stress/stretch caused at birth due to air-breathing; (5) Down- regulation of EGFR indicate altered mesenchymal-epithelial interactions and possible influence on lung proliferation and differentiation.

Physiological levels of beta-amyloid induce cerebral vessel dysfunction and reduce endothelial nitric oxide production

beta-amyloid (A beta), the major component of senile plaques in Alzheimer's disease (AD), normally circulates in the blood at nanomolar levels but is elevated in AD. Previous studies have found that high concentrations (10(-5)-10(-4) M) of A beta result in neuronal cell death. Here we show that physiological levels of soluble A beta can induce dysfunction in perfused rat cerebral vessels and in cultured endothelial cells. At concentrations of 10(-9)-10(-6) M, A beta induced a significant concentration-dependent reduction of NO production in endothelial cells. At 10(-8) M, A beta significantly decreased the sensitivity of cerebral vessels to acetylcholine (ACh), an endothelium dependent vasodilator. At 10(-7) M and higher concentrations, A beta significantly reduced the maximum response of vessels to ACh, and induced significant endothelial cell death. A beta (10(-9)-10(-5) M) did not cause any detectable change in nitric oxide synthase levels. The results suggest that a modest increase in the concentration of A beta above its normal physiological level in the circulation, as found in the early stages of AD, results in decreased NO production and vessel sensitivity to endothelium-dependent vasodilation that could lead to constricted blood vessels and ischemia in the surrounding tissue. Further increases in A beta concentration, which may occur in the later stages of AD, result in cell death and decreased maximum vasodilator response of cerebral vessels.

Dimeric phenalenyl-based neutral radical molecular conductors

We report the preparation, crystallization, and solid-state characterization of ethyl (3)- and butyl (4)-substituted spiro-biphenalenyl radicals. Both of these compounds are found to be conducting face-to-face pi-dimers in the solid state but with different room-temperature magnetic ground states. At room temperature, 4 exists as a diamagnetic pi-dimer (interplanar separation of approximately 3.1 A), whereas 3 is a paramagnetic pi-dimer (interplanar separation of approximately 3.3 A), and both compounds show phase transitions between the paramagnetic and diamagnetic forms. Electrical resistivity measurements of single crystals of 3 and 4 show that the transition from the high-temperature paramagnetic pi-dimer form to the low-temperature diamagnetic pi-dimer structure is accompanied by an increase in conductivity by about 2 orders of magnitude. This behavior is unprecedented and is very difficult to reconcile with the usual understanding of a Peierls dimerization, which inevitably leads to an insulating ground state. We tentatively assign the enhancement in the conductivity to a decrease in the on-site Coulombic correlation energy (U), as the dimers form a super-molecule with twice the amount of conjugation.

[A theoretical study on vibrational spectra of S7 rings]

The geometries of S7 rings with the chair-type and boat-type conformations have been optimized using SCF-HF and hybrid density functional methods. (B3LYP) with the split valence 3-21 + G(d) and 6-31 + G(d) basis sets. Vibrational spectra of S7 rings have been predicted by using the same two methods: B3LYP/6-31 + G(d) and HF/3-21 + G(d) over the geometries optimized above, respectively. The symmetries of normal vibrational modes have been assigned. We also make comparisons between the present predictions and the previous experimental data.

Potassium channel openers prevent beta-amyloid toxicity in bovine vascular endothelial cells

There is increasing evidence that the cerebrovasculture may be involved in the pathology of Alzheimer's disease. Here, we report that potassium channel openers (KCOs) inhibit dose and time dependent necrosis induced by beta-amyloid (Abeta) in cultured vascular endothelial cells. Cell proliferation rate was assayed by a colorimetric method. Abeta cytotoxicity and inhibition by the K(ATP) channel opener diazoxide and the K(Ca) channel opener NS1619 was correlated with changes in nitric oxide (NO) production. The protective effects were partly blocked by potassium channel blockers. Toxicity of Abeta and KCO protection was verified by histological examination of endothelial cells with scanning electron microscopy. eNOS levels in endothelial cells were not changed by any of the treatments. The results suggest that disruption of K(+) channels function may be a critical step in Abeta-induced cytotoxicity in endothelial cells by alteration of NO release.

The protective effect of K+ channel openers on beta-amyloid induced cerebrovascular endothelial dysfunction

Amyloid angiopathy is characterized by amyloid beta-peptide (A beta) deposition and may contribute to the cerebrovascular abnormalities that precede the onset of Alzheimer's Disease (AD). That aberrant potassium (K+) channel function occurs in AD patients is supported by deleterious effects of A beta on normal fibroblast K+ channels and prevention of A beta-induced toxicity by potassium channel openers (KCOs) in neuronal cell culture. We report here that KCOs protect cerebral and peripheral vessels against the endothelial damage induced by A beta. Pressurized posterior cerebral artery and aortic ring segments from the rat were constricted and then relaxed with the endothelium-dependent vasodilator acetylcholine before and after incubation with A beta (10(-6) M), or pre-treatment with KCOs before the addition of beta-amyloid. Vessels treated with A beta exhibited features of endothelial dysfunction: enhanced vasoconstriction and diminished endothelium-dependent vasodilation. Pre-treatment with KCOs significantly antagonized the A beta effect in both cerebral and aortic vessel segments. This protection was provided by both KCa and KATP channel openers. Endothelial damage by A beta and protection by KCOs was verified by electron microscopy. The K+ channel blocker, TEA, reversed the protective effect of KCO. The results suggest that potassium channel openers protect against A beta induced endothelial dysfunction and that KCOs may have a role in the treatment of degenerative cerebrovascular disease as seen in stroke, AD and aging.

A hypergraphic model of medical informatics: curriculum development guide

Medical informatics, as a descriptive, scientific study, must be mathematically or theoretically described. Is it important to define a model for medical informatics? The answer is worth pursuing. The medical informatics profession stands to benefit three-fold: first, by clarifying the vagueness of the definition of medical informatics, secondly, by identifying the scope and content for educational programs, and, thirdly, by defining career opportunities for its graduates. Existing medical informatics curricula are not comparable. Consequently, the knowledge and skills of graduates from these programs are difficult to assess. The challenge is to promote academics that develops graduates for prospective employers to fulfill the criteria of the health care industry and, simultaneously, compete with computer science programs that produce information technology graduates. In order to meet this challenge, medical informatics programs must have unique curricula that distinguishes its graduates. The solution is to educate students in a comparable manner across the domain of medical informatics. This paper discusses a theoretical model for medical informatics.

Identification of a novel alternatively spliced mRNA of murine pulmonary surfactant protein B

An alternatively spliced mRNA of pulmonary surfactant protein B (SP-B) was identified in murine lung. Sequencing analysis revealed a 69 base-pair (bp) deletion at the beginning of exon 7 of SP-B, presumably the result of an alternative splicing event. Reverse transcription-polymerase chain reaction (RT-PCR) of mouse, rat, and rabbit lung RNA revealed the existence of full-length and the 69-bp deleted short form. Ribonuclease protection assay of the SP-B messenger RNA (mRNA) demonstrated expression of both isoforms in five strains of adult and fetal mice with different genetic backgrounds, as well as in rabbit, but not in human. Splice junction sequences in exon 6 and at the exon 7 splice boundary for the two isoforms are similar, including AG doublet identity, but sequence differences do not account for species variation in isoform abundance. The abundance of the short SP-B mRNA isoform was approximately 30% of total SP-B mRNA in mouse and rabbit. Analysis of precursor SP-B protein in mouse lung suggested that the two mRNA species are expressed as stable protein isoforms.

Validation of computer-mediated open-ended standardized patient assessments

Quantitative information regarding the development of students' clinical reasoning skills is valuable in assessing third- and fourth-year medical students' clinical knowledge. Standardized patient cases are often used to obtain this quantified information. These cases typically involve a post-patient examination consisting of a series of closed-ended multiple-choice questions. Many medical educators question whether the results from the closed-ended multiple-choice questions truly reflect students' clinical knowledge and reasoning proficiency. Since 1995, the Kirksville College of Osteopathic Medicine (KCOM) has used a computer program, SOAP Note Plus, for standardized patient assessment of students to automate the post-encounter documentation and evaluation. This paper describes the development of the SOAP Note Plus program and a validation study which was conducted to determine the empirical association between the computer-mediated closed-ended and open-ended post-encounter standardized patient assessments. Correlation and GENOVA statistics were used in the analysis of the performance of third-year medical students on the closed-ended and the open-ended assessments following standardized patient encounters and the relationship to their undergraduate GPA, first 2-year medical school GPA and the actual clinical rotation evaluations. The initial results show the positive relationship between the open-ended assessment and the actual clinical rotation evaluations. undergraduate GPA and the first two-years of medical school GPA.

[Physiological characteristics of single K+ channel currents (Ik) in cerebellar cortical neurons of neonatal rat]

The characteristics of single K+ channels in cultured cerebellar granule neurons of neonatal rat were studied by the cell- attached and inside-out configurations of patch clamp technique. The results are as follows: the predominant conductance of single channel was 25PS, the currents amplitude, the mean open time and the open probability were dependent of membrane potential, the open time distribution histograms were fitted by two exponential components, the channel activity was not inactivated during 20 s period, independent of calcium and blocked by tetraethylammonium. These results indicated that the single channel was a delayed rectifier (Ik). It is suggested that the non-inactivating channel with conductance of 25pS which exists in the cerebellar granule cell might be a new subtype of Ik channel.

[A deep regional impedance method measuring the blood distribution in the lung]

A new deep regional impedance method to measure the blood distribution in the lung has been developed. Using a multi-electrode system, the method simultaneously detects impedance information of chest, and back including lung and the thorax, then extracts the impedance information directly from lung with a special data processing approach in order to eliminate thorax effect on the measurement. The salt pool experiment and the preliminary application of measuring the blood distribution in the lung have been made. The results show that the method raises the relative sensitivity and the distinguishability of the blood measurement in the lung, and as a new deep regional impedance measurement method, it has a good prospects of clinical application in the future.

Long-term effects of instilled mineral dusts on pulmonary surfactant isolated from monkeys

Experiments were carried out to determine the long-term effect of instillation of 500 mg of generic bituminous, anthracite, quartz, or titanium dioxide (TiO2) dust on the composition of pulmonary surfactant. Dust was instilled in the caudal lobe of the right lungs of female pigtailed macaque monkeys (Macaca nemestrina). The composition of surfactant isolated from cell-free bronchoalveolar lavage (CF-BAL) samples obtained from right lungs (dust exposed) at various times over the following year was compared with that of surfactant isolated from CF-BAL from left lungs (dust free). Little change was seen in the amount of surfactant-associated lipid phosphorus as a result of exposure to dust. Exposure to quartz, anthracite, or TiO2 dust induced a significant increase in the total amount of protein in the surfactant-enriched fraction. The relative amount of specific proteins was also altered: surfactant-associated protein A decreased, and the amount of the heavy and light chains of immunoglobulin molecules (identified by NH2-terminal amino acid sequence analysis) increased. These changes were visible more than a year after instillation of quartz and at least 3 months after instillation of anthracite dust. Despite variation in the responses of the individual animals, the changes observed might serve as an indicator of the severity of the effect of exposure of the lung to mineral dust and/or to pathogens.