Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

Advances in the Study of MG53 in Cardiovascular Disease

Cardiovascular diseases represent a global health crisis, and understanding the intricate molecular mechanisms underlying cardiac pathology is crucial for developing effective diagnostic and therapeutic strategies. Mitsugumin-53 (MG53) plays a pivotal role in cell membrane repair, has emerged as a multifaceted player in cardiovascular health. MG53, also known as TRIM72, is primarily expressed in cardiac and skeletal muscle and actively participates in membrane repair processes essential for maintaining cardiomyocyte viability. It promotes k-ion currents, ensuring action potential integrity, and actively engages in repairing myocardial and mitochondrial membranes, preserving cardiac function in the face of oxidative stress. This study discusses the dual impact of MG53 on cardiac health, highlighting its cardioprotective role during ischemia/reperfusion injury, its modulation of cardiac arrhythmias, and its influence on cardiomyopathy. MG53's regulation of metabolic pathways, such as lipid metabolism, underlines its role in diabetic cardiomyopathy, while its potential to mitigate the effects of various cardiac disorders, including those induced by antipsychotic medications and alcohol consumption, warrants further exploration. Furthermore, we examine MG53's diagnostic potential as a biomarker for cardiac injury. Research has shown that MG53 levels correlate with cardiomyocyte damage and may predict major adverse cardiovascular events, highlighting its value as a biomarker. Additionally, exogenous recombinant human MG53 (rhMG53) emerges as a promising therapeutic option, demonstrating its ability to reduce infarct size, inhibit apoptosis, and attenuate fibrotic responses. In summary, MG53's diagnostic and therapeutic potential in cardiovascular diseases presents an exciting avenue for improved patient care and outcomes.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB 221009A, which serendipitously occurred within the instrument field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger, then rose to a peak about 10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

Peta-electron volt gamma-ray emission from the Crab Nebula

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10^-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 10³⁶ ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

[Preoperative treatment of uterine fibroids with low-dose mifepristone: a multicenter, randomized, double-blind, placebo-controlled, parallel-group study]

Objective: To evaluate the clinical efficacy and safety of oral mifepristone (10 mg/day) versus placebo in the preoperative treatment of uterine fibroids. Methods: This study was a multi-center, randomized, double-blind, placebo, parallel controlled trial. A total of 132 patients with uterine fibroids were randomly divided into study group and control group, with 66 cases in each group. The patients in the study group orally took 1 tablet/day of mifepristone (dose of 10 mg/tablet), the patients in the control group orally took 1 tablet/day of placebo, and both groups were treated for 3 months. The primary efficacy evaluation indicators were the change rate of maximum fibroid volume; the secondary efficacy evaluation indicators included amenorrhea rate, improvement of subjective symptoms and anemia; the safety evaluation indicators included the analysis of adverse events and changes in laboratory biochemical indicators. Results: At the end of treatment, the maximum leiomyoma volume was reduced by 25.97% (95%CI: -34.79%--15.95%) in the study group and reduced by 1.51% (95%CI: -13.03%-11.54%) in the control group. The change rate of the maximum leiomyoma volume before and after treatment in the study group was significantly greater than that in the control group, and the difference in the change rate of the maximum leiomyoma volume between the two groups was -24.84% (95%CI: -36.56%--10.94%), which was much higher than the 10% superiority threshold goal set by this study within the 95%CI interval. At the end of treatment, the complete amenorrhea rate [84% (52/62)], dysmenorrhea elimination rate [98% (61/62)], and menstrual blood loss disappearance rate [87% (54/62)] in the study group were significantly higher than those in the control group (all P<0.05). At the end of treatment, the mean hemoglobin [(131±13) g/L], red blood cell count [(4.5±0.4)×10¹²/L] and hematocrit (0.39±0.03) in the study group were significantly increased compared with the baseline, and the differences had statistical significance (all P<0.05); after treatment, the differences in the above three indicators between the two groups had statistical significance (all P<0.01). The serum estradiol level in the study group was significantly lower than that in the control group at the end of treatment, and the difference was statistically significant (P<0.01). There were no significant differences in follicle-stimulating hormone and cortisol levels before and after treatment between the two groups (P>0.05). The overall incidences of any adverse event were not significantly different between the two groups (all P>0.05). Abdominal pain was the most common adverse event in the study group [9% (6/65)], but the incidence was not significantly increased compared with the control group [3% (2/64); P>0.05]. Conclusion: Compared with placebo, oral mifepristone 10 mg/day is significantly superior to placebo in reducing the size of uterine fibroids and improving anemia, without significant adverse reactions, and could be used as a drug treatment for patients with of uterine fibroids before surgery.

Development and application of isothermal amplification methods for rapid detection of F4 fimbriae producing Escherichia coli

Enterotoxigenic Escherichia coli (ETEC) is the causative agent of a wide range of diseases, which are the important cause of illness and mortality in piglets. ETEC strains expressing F4 fimbriae are frequently associated with post-weaning diarrhea (PWD) and lead to great economic losses in swine production industry worldwide. The aim of this study was to establish a rapid and effective isothermal amplification method for detection of F4 fimbriae. Loop-mediated isothermal amplification (LAMP), Polymerase spiral reaction (PSR) and cross-priming ampli- fication (CPA) were used to develop and optimize the detection method first time. Subsequently, the specificity and sensitivity of these methods were evaluated, and the clinical samples were detected with these methods. All the F4-positive samples could produce ladder-like amplifica- tions products and lead the chromogenic substrate SYBR Green I produce green fluorescence, while in blank control and negative samples lack of this pattern or remained orange. The sensi- tivity of LAMP and CPA were 10 times higher than PSR method. Meanwhile, these three methods were validated with clinical samples, 7 were found positive, while 125 samples were negative, the testing results were consisted with the real-time PCR method. These findings suggested that the isothermal amplification based on the F4 fimbriae is a rapid, effective and sensitive method under resource constrains.

Transmembrane protein ADAM29 facilitates cell proliferation, invasion and migration in clear cell renal cell carcinoma

Abnormal expression of ADAM29 has been frequently reported in several cancers, however, its role in clear cell renal cell carcinoma (ccRCC) has not evaluated in detail. Herein, we attempt to determine the biological role and the action mechanism of ADAM29 in ccRCC. Bioinformatics analysis based on the ccRCC RNA-Seq dataset from TCGA database revealed that ADAM29 was up-expressed in ccRCC tissues by comparison with normal tissues. And a significant increase of ADAM29 expression was also observed in 3 ccRCC cell lines (UT33A, Caki-1, and786-O) in comparison with normal cell line. Besides, high level of ADAM29 was found to be connected with the poor prognosis and could be considered as an independent prognosticator for patients with ccRCC. Furthermore, functional experiments in vitro demonstrated that ADAM29 promoted the growth, invasion and migration of ccRCC cells. Moreover, Western blot assays indicated that ADAM29 was positively correlated with the level of proliferation-related proteins Cyclin D1 and PCNA and motion-related proteins MMP9 and Snail. Our data indicate that ADAM29 acts as an oncogene that increases tumour cells proliferation, invasion and migration partly by regulating the expression of Cyclin D1/PCNA/MMP9/Snail, suggesting that ADAM29 may become a prognosticator and therapeutic candidate for ccRCC.

Comparison of outcomes using radiotherapy or brachytherapy after resection of primary adenoid cystic carcinoma in oral and maxillofacial regions

We wished to investigate the outcome of surgery combined with external-beam radiotherapy (EBRT) or brachytherapy (¹²⁵I seeds) for the treatment of primary adenoid cystic carcinoma (ACC) of the oral and maxillofacial region. Data of patients with primary ACC were reviewed retrospectively. Patients were divided into EBRT and brachytherapy groups. Wide tumor excision was done to achieve negative margins. Standard radiotherapy in the EBRT group was 60 Gy. A treatment-planning system was used to create implantation plans with a prescribed dose of 60-120 Gy and ¹²⁵I seeds were implanted postoperatively. Kaplan-Meier method and log-rank tests were used to analyze local control and survival. The median duration of followup was 66.1 and 46.8 months for the EBRT group and brachytherapy group, respectively. There was no significant difference in local control, control of metastasis to regional lymph nodes, or control of distant metastasis between the two groups. There was no significant difference in overall survival, disease-specific survival, or disease-free survival in the two groups at 3 years and 5 years. The prevalence of complications in the brachytherapy group was lower than that in the EBRT group. Both methods elicited good treatment effects, but the prevalence of adverse events was lower in the brachytherapy group.

Aspirin protects human coronary artery endothelial cells by inducing autophagy

Although the use of aspirin has substantially reduced the risks of cardiovascular events and death, its potential mechanisms have not been fully elucidated. In a previous study, we found that aspirin triggers cellular autophagy. In the present study, we aimed to determine the protective effects of aspirin on human coronary artery endothelial cells (HCAECs) and explore its underlying mechanisms. HCAECs were treated with oxidized low-density lipoprotein (ox-LDL), angiotensin II (Ang-II), or high glucose (HG) with or without aspirin stimulation. The expression levels of endothelial nitric oxide (NO) synthase (eNOS), p-eNOS, LC3, p62, phosphor-nuclear factor kappa B (p-NF-κB), p-p38 mitogen-activated protein kinase (p-p38 MAPK), and Beclin-1 were detected via immunoblotting analysis. Concentrations of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured via ELISA. NO levels were determined using the Griess reagent. Autophagic flux was tracked by tandem mRFP-GFP-tagged LC3. Results showed that aspirin increased eNOS level and reduced injury to the endothelial cells (ECs) caused by ox-LDL, Ang-II, and HG treatment in a dose-dependent manner. Aspirin also increased the LC3II/LC3I ratio, decreased p62 expression, and enhanced autophagic flux (autophagosome and autolysosome puncta) in the HCAECs. p-NF-κB and p-p38 mitogen-activated protein kinase inhibition, sVCAM-1 and sICAM-1 secretion, and eNOS activity promotion by aspirin treatment were found to be dependent on Beclin-1. These results suggested that aspirin can protect ECs from ox-LDL-, Ang-II-, and HG-induced injury by activating autophagy in a Beclin-1-dependent manner.

[Analysis on the duration of intestinal detoxification in restaurant employee infected with Norovirus during the outbreak]

Objective: To explore the duration of intestinal detoxification and its related factors infected with Norovirus, and to provide scientific evidences for the prevention and control of acute gastroenteritis caused by Norovirus in the future. Methods: Follow up and sampling program on 115 employees in a restaurant outbreak of Norovirus in Chengdu in 2017 was carried out. Anal swab was collected every 3 d or 7 d for nucleic acid detection, and the experimental results were statistically analyzed. Results: The positive rates of Norovirus in restaurant employee were 14.78%, 7.89%, 3.51% and 0.88% on the 7(th), 11(th), 17(th) and 24(th) day, respectively. During the follow-up period, the positive rates of Norovirus decreased as time increased. The positive rate of all employees was up to 14.78% on the 7(th) day. The positive rates had no significant difference between different sex and between different types of work. The duration of detoxification averaged 14.94 days and the maximum of detoxification time was on 28 days. The detoxification period of treatment case was shorter than that of asymptomatic carriers. Conclusions: There were asymptomatic carriers in restaurant employees during the outbreak of Norovirus that their role as a source of infection in the transmission of Norovirus should not be neglected. In the treatment of the epidemic, we should strengthen the sampling and testing of practitioners, and strictly implement isolation measures for positive detection.

Operation of RF-driven negative hydrogen ion source in China Spallation Neutron Source

The China Spallation Neutron Source started delivering neutron beams to users in March 2018. To upgrade the beam power to 500 kW and improve the performance of the ion source, an RF-driven negative hydrogen (H^-) ion source is under development. The source has a silicon nitride ceramic plasma chamber surrounded by a 4.5-turn antenna. The plasma is ignited by a pulsed DC spark gap and then driven by a 2 MHz solid-state amplifier with a repetition rate of 25 Hz. The commissioning of the source started in January 2019. When uncesiated, it produced about 20 mA beam at an RF power of 32 kW and pulse width of 450 μs. This paper describes the configuration of the ion source, several peculiar technologies used in it, and the first negative hydrogen (H^-) ion beam extraction.

[A randomized controlled study of peramivir, oseltamivir and placebo in patients with mild influenza]

Objectives: To evaluate the effectiveness and safety of peramivir trihydrate in patients with influenza. Methods: This was a randomized, double-blind, double-dummy, placebo and positive control, multicenter clinical trial, comparing peramivir trihydrate with oseltamivir and placebo. The inclusive criteria were 15-70 years old, onset within 48 h, positive rapid influenza antigen test, and febrile (>38℃) accompanied with at least two associated symptoms. The severe cases complicated with chronic pulmonary and cardiac diseases, malignancies, organ transplantation, hemodialysis, uncontrolled diabetes, immunocompromised status, pregnancy and coexistence of bacterium infections were excluded. All patients were randomized 2∶2∶1 to receive peramivir, oseltamivir and placebo respectively. The primary endpoint was the disease duration, the secondary endpoints included time to normal axillary temperature and normal living activities, viral response, and adverse effects. Results: Following informed consent, 133 patients were included in this study. Four patients were exclude due to missing medical records, not fitting inclusion or exclusion criteria and poor compliance. A total of 129 patients were finally analyzed, including 49 cases, 54 cases and 26 cases in peramivir group, oseltamivir group and placebo group. The median disease duration were 96 (76, 120) hours, 105 (90,124) hours, and 124 (104, 172) hours in three groups respectively (P>0.05) . The time to normal axillary temperature, normal living activities and viral response were not significantly different in three groups (P>0.05) . Conclusion: The value of antiviral therapy in patients with mild influenza needs to be further determined.

[Study of surgery combined with 125I brachytherapy for adenoid cystic carcinoma of oral and maxillofacial region]

OBJECTIVE

To retrospectively analyze the results of treatment outcome by surgery combined with ₁₂₅I brachytherapy and correlative factors of adenoid cystic carcinoma (ACC).

METHODS

In the study, 75 patients with primary ACC of oral and maxillofacial region were treated by surgery combined with ₁₂₅I seeds brachytherapy. Radical resection or subtotal resection was applied for the tumor. The brachytherapy treatment planning system was used to create implant plans with the prescribed dose of 60 Gy to 120 Gy. The ₁₂₅I seeds were implanted intraoperatively or postoperatively. The regular follow-up was required. The Kaplan-Meier method was used to assess the tumor control rate and the patients' survival rates. Meanwhile, the Cox regression analysis was used to find out the prognostic factors.

RESULTS

Local control rates at the end of 3 and 5 years were as follows: T1-T2, 92.2% and 82.0%; T3-T4, 82.6% and 82.6%; and overall, 90.0% and 78.8%. The disease-free survival rates were 74.9% and 54.3%, respectively. The overall survival rates for all the patients were 86.0% and 79.6%, respectively at the end of 3 and 5 years and were 91.3% and 91.3% for T1-T2 patients vs. 73.9% and 59.7% for T3-T4 patients. Distant metastasis-free survival rates at the end of 3 and 5 years were 84.4% and 76.7%, respectively. The distant metastasis-free survival rates at the end of 3 and 5 years were 83.4% and 79.6% with T1-T2 lesion compared with 86.0% and 67.8% with T3-T4 lesion. According to the COX univariate analysis and multivariate analysis, the risk of local recurrence would be raised by the age. Tumor stage and tumor site were the prognostic factors of the overall survival rates.

CONCLUSION

₁₂₅I brachytherapy conducted as an adjuvant therapy postoperatively of ACC of oral and maxillofacial region can acquire satisfactory localregional control, distant metastasis-free survival, disease-free survival and overall survival. Tumors are prone to recur on the older patients. Patients having advanced tumor stage or tumor located in the nasal cavity or sinuses will suffer lower survival rates.

[The comparison of preemptive analgesic efficacy between short-acting ketamine and long-acting parecoxib]

Objective: To compare the analgesic efficacy between preoperative single-dose ketamine, a short-acting medicine and parecoxib, a long-acting medicine for reducing analgesic consumption in the first 24 h after-operation. Methods: Eighty-one patients from Beijing Chaoyang Hospital undergoing laparoscopic uterus surgery between April and December 2015 were randomly divided into three groups: control group (group C), ketamine group (group K) and parecoxib sodium group (group P). All patients were anesthetized with general anesthesia and received sufentanil-based patient-controlled intravenous analgesia (PCIA). After induction and 10 min before incision, patients in group K, P and C were injected with intravenous 0.5 mg/kg ketamine, 40 mg parecoxib and 2 ml normal saline, respectively. The primary outcome was sufentanil consumption within 1 h and 24 h after surgery. Other outcomes included the visual analog scale (VAS) pain score at 0, 15, 30, 45min and 1, 2, 4, 8, 24 h after surgery, PCIA effective trigger times, and adverse reactions. Results: The postoperative sufentanil consumptions within 1 h in group K and P were(4.420±1.836)μg and (2.878±1.984)μg, respectively, and consumptions within 24 h were(28.200±3.712)μg and (25.511±4.037)μg, respectively, which were significantly less than that in group C with (6.144±2.346)μg within 1 h and (31.505±7.042)μg within 24 h (F=15.360, 8.406, all P<0.05). Patients in group P needed less sufentanil than group K in 1 h after surgery (P<0.05), however, the difference was not statistically significant in 24 h(P>0.05). The PCIA trigger times were 2(3.75) in group C, 0(1.50) in group K, and 0(1.00) in group P. Group K and P had less PCIA trigger times compared to group C (all P<0.05). Compared to group C, group K and P had lower VAS scores at 0, 15, 30 min after surgery and group P had lower VAS scores at 1, 15, 30, 45 min, 2 h after surgery, respectively (all P<0.05). There were no differences between groups in the incidence of any adverse effects(all P>0.05). Conclusion: A single injection of short-acting ketamine before laparoscopic uterus surgery, has the same efficacy as long-acting parecoxib for opioid-sparing effect in the first 24 h after-operation. However, parecoxib has better analgesic effect in the early postoperative period.

[Effects of Lactobacillus paracasei N1115 combined with fructooligosaccharides on non-alcoholic fatty liver disease induced by high-fat diet in mice]

Objective: To investigate the effects of Lactobacillus paracasei N1115 combined with fructooligosaccharides (FOS) on non-alcoholic fatty liver disease (NAFLD) in mice and its possible mechanism. Methods: A total of 50 male C57 mice were randomly and equally divided into five experimental groups. Group 1 received a normal diet (ND). Other four groups received a high-fat diet (HFD) to establish NAFLD models. In addition to HFD, group 3 received Lactobacillus paracasei N1115 (2.2×10(9) CFU/mL), group 4 received FOS (4 g/kg per day), and group 5 received Lactobacillus paracasei N1115 (2.2×10(9) CFU/mL) and FOS (4 g/kg per day). All groups received continuous intervention for 16 weeks. The following indices were measured for all groups after intervention: general condition, the levels of fasting blood glucose, insulin, and lipopolysaccharide (LPS), and the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and interferon (IFN)-γ in the serum and liver. The mRNA levels of Toll-like receptor (TLR)4, nuclear factor (NF)-κb, insulin receptor (InsR), and insulin receptor substrate (IRS)-1 were measured by real-time RT-PCR. The data were subjected to one-way analysis of variance and comparison between groups was made by Bonferroni method. Results: Compared with group 2, groups 3, 4, and 5 had significantly lower body weight, Lee's index, liver index, and the levels of blood glucose and insulin resistance (P < 0.05). The serum level of LPS in group 2 was significantly higher than that in the other experimental groups (group 1: 8.80 ± 0.85 U/L, group 3: 12.31 ± 1.01 U/L, group 4: 12.27 ± 0.98 U/L, and group 5: 10.17 ± 0.79 U/L vs group 2: 15.45 ± 1.14 U/L, F = 55.117, P < 0.001). The levels of TNF-α, IL-1β, IL-6, and IFN-γ in the serum and liver in group 2 were also significantly higher than those in the other groups (P < 0.05). Group 2 had significantly higher mRNA levels of TLR4 and NF-κb in the liver than the other groups (F = 82.933, P < 0.001; F = 149.033, P < 0.001); however, it had significantly lower mRNA levels of InsR and IRS-1 in the liver than the other groups (F = 33.347, P < 0.001; F = 70.225, P < 0.001). Conclusion: Lactobacillus paracasei N1115 combined with FOS can reduce the level of LPS in the blood circulation, inhibit activation of the LPS/TLR4 signaling pathway, and reduce the release of inflammatory factor and the body's insulin resistance, so it can relieve NAFLD.

Dynamics of methanogenesis, ruminal fermentation, and alfalfa degradation during adaptation to monensin supplementation in goats

This study aimed to examine the temporal (hourly within a day and daily over the long term) effects of monensin on CH₄ emissions, ruminal fermentation, and in situ alfalfa degradation in dairy goats during dietary monensin supplementation by controlling the confounding effects of feed intake and ambient temperature. Six ruminally cannulated dairy goats were used, and they were housed in environmental chambers and fed a restricted amount of ration throughout the experiment. The experiment included a baseline period of 20 d followed by a treatment period of 55 d with 32 mg of monensin/d. During the whole experiment, CH₄ production was measured every 5 d, whereas fermentation characteristics and in situ alfalfa degradation were analyzed every 10 d. The CH₄-depressing effect of monensin was time dependent on the duration of treatment, highly effective at d 5 but thereafter decreased gradually until d 55 even though CH₄-suppressing effect still remained significant. The decreasing effects of monensin on ruminal acetate proportion and acetate to propionate ratio also faded over days of treatment, and the acetate proportion returned up to the pre-supplementation level on d 50. Monensin supplementation elevated ruminal propionate proportion and decreased the effective ruminal degradability of alfalfa NDF, but both measurements tended to recover over time. The postprandial increase rate of hourly CH₄ emissions was reduced, whereas that of propionate proportion was enhanced by monensin supplementation. However, the postprandial responses to monensin in CH₄ emission rates, ruminal VFA profiles, and in situ degradation kinetics declined with both hours after feeding and days of treatment. Our results suggest that the CH₄-suppressing effect of monensin supplementation in goats was attributed to reductions in both ruminal feed degradation and acetate to propionate ratio, but those reductions faded with time, hours after feeding, and days of treatment.

[The epidemiology of bloodstream infections in Fuxing Hospital in 2012 in Beijing]

OBJECTIVE

To investigate the etiology, clinical features and outcome of hospitalized patients with bloodstream infections (BSIs) in a tertiary hospital.

METHODS

Positive blood cultures were obtained from the microbiological laboratory in Fuxing Hospital, Capital Medical University from January 1, 2012 to December 31, 2012. BSIS events were identified and the epidemiology data were collected.

RESULTS

A total of 149 patients and 154 BSIs events were confirmed by pathogenic and clinical evidence. The in-patients' BSIs rate was 0.8% in our hospital in 2012. According to the disease entities of the first BSIs onset, 15 patients (10.1%) were from surgical departments, 83 patients (55.7%) from the medical departments, and 51 patients (34.2%) from ICU. Thirty-three patients (22.1%) were diagnosed as septic shock. Sixty-eight patients died during hospital stay. The in-hospital mortality rate was 45.6%. Among the 154 BSIs events, 125 (81.2%) were nosocomial and 29 (18.8%) were community-acquired. A total of 188 strains were isolated from all BSIs, including 106 strains of (56.4%) gram-negative bacilli, 67 (35.6%) strains of gram-positive bacteria, and 15 (8.0%) strains of fungi. One hundred and fifty-nine strains of bacteria (84.6%)were isolated from 125 events of hospital-acquired BSIs. Twenty-six strains of bacteria were from catheter related bloodstream infections (CRBSIs). In gram-negative BSIs, there were more enterobacteriaceae in community-acquired BSIs. More non-fermentative bacteria were found in hospital-acquired BSIs than in community-acquired ones. The distribution of gram-negative bacilli was quite different between surgical departments, non-surgical departments and ICU (P=0.049).

CONCLUSIONS

Pathogens of BSIs are quite different according to disease entities and where the patients are from. Local epidemiology of BSIs and distribution of related pathogens are helpful to physicians searching the optimal empirical antibiotics and improving the outcome.

Effect of calcium channels blockers and inhibitors of the renin-angiotensin system on renal outcomes and mortality in patients suffering from chronic kidney disease: systematic review and meta-analysis

BACKGROUND

The renoprotective effect of inhibitors of renin-angiotensin system (RAS) has been identified through placebo-controlled trials. However, the effect of calcium-channel blockers (CCBs) on renal system is still controversial. Our current meta-analysis includes available evidences to compare the effect of dihydropyridine CCBs and ACEIs or ARBs on renal outcomes and mortality. We also further investigate whether CCBs can be used in combination with inhibitors of RAS to improve the prognosis of patients with chronic kidney disease (CKD).

METHODS AND RESULTS

Electronic databases were searched up to July 2012, for clinical randomized controlled trials, assessing the effect of dihydropyridine CCBs on the incidence of end-stage renal disease (ESRD) and all-cause mortality in contrast to ACEIs or ARBs. Eight clinical trials were included containing 25,647 participants. ESRD showed significantly higher frequency with CCBs therapy compared with ACEIs or ARBs therapy, though blood pressure was decreased similarly in both groups in every trial (OR, 1.25; 95% CI, 1.05-1.48; p = 0.01). In contrast, there was no significant difference in the incidence of all-cause mortality between these two groups, though ACEIs or ARBs exhibited better renoprotective effect compared to CCBs (OR, 0.96; 95% CI, 0.89-1.03; p = 0.24).

CONCLUSIONS

CCBs did not increase all-cause mortality incidence in patients with CKD though they displayed weaker renoprotective, compared to ACEIs or ARBs therapy. Our results suggest the combination of a CCB and an ACEI or ARB should be a preferable antihypertensive therapy in patients with CKD, considering their higher effect in decreasing blood pressure and fewer adverse metabolic problems caused.

Effects of sub-chronic aluminum chloride exposure on rat ovaries

AIMS

This experiment investigated the effects of sub-chronic aluminum chloride (AlCl3) exposure on rat ovaries.

MAIN METHODS

Eighty female Wistar (5weeks old) rats, weighed 110-120g, were randomly divided into four treatment groups: control group (CG), low-dose group (LG, 64mg/kg BW AlCl3), mid-dose group (MG, 128mg/kg BW AlCl3) and high-dose group (HG, 256mg/kg BW AlCl3). The AlCl3 was administered in drinking water for 120days. The ovarian ultrastructure was observed. The activities of acid phosphatase (ACP), alkaline phosphatase (ALP), succinate dehydrogenase (SDH), Na(+)-K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPase, the contents of Fe, Cu and Zn, and the protein expression of follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in the ovary were determined.

KEY FINDINGS

The results showed that the structure of the ovary was disrupted, the activities of ALP, ACP, SDH, Na(+)-K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPase, the contents of Zn, Fe and the protein expression of FSHR and LHR were lowered, and the content of Cu was increased in AlCl3-treated rats than those in control.

SIGNIFICANCE

The results indicate that sub-chronic AlCl3 exposure caused the damage of the ovarian structure, the disturbed metabolism of Fe, Zn and Cu and the decreased activities of Na(+)-K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPase in the ovary, which could result in suppressed energy supply in the ovary. A combination of suppression of energy supply and reduction of expression of FSHR and LHR could inhibit ovulation and corpus luteum development, leading to infertility in female rats.

Genetic diversity of Saccharum spontaneum from geographical regions of China assessed by simple sequence repeats

Saccharum spontaneum is the most variable wild relative of sugarcane with potential for use in sugarcane improvement programs. In order to help preserve and exploit this species, 152 accessions from eight major geographical regions in China, including Hainan, Guangdong, Guangxi, Yunnan, Sichuan, Guizhou, Fujian, and Jiangxi provinces, were investigated by analyzing 20 simple sequence repeats (SSRs), including 11 genomic SSRs (gSSRs) and nine SSRs developed from expressed sequence tags (EST-SSRs). A total of 454 alleles were generated by the 20 SSRs, with 295 and 159 alleles detected by gSSRs and EST-SSRs respectively. The Mantel test showed significant correlation between genetic matrixes among the studied accessions revealed by gSSRs versus EST-SSRs, although the average polymorphism of EST-SSRs (17.7) was much lower than that of gSSRs (26.8). Among the eight provinces, collections from Guizhou were the most diverse and those from Guangdong were the most distinct. Clustering analysis and principal component analysis accordantly classified the accessions into four groups, which were "Southwest group", "Hainan group", "Guangdong group", and "Guangxi group", based on the geographical origin of the major accessions in each group, demonstrating that geographical factors play an important role in the pattern of genetic structure of Chinese S. spontaneum. As two (Guizhou and Yunnan) of the three provinces with highest genetic diversity are located in southwest China, we concluded that southwest China is the region with the highest genetic diversity of S. spontaneum.

Decreased peripheral blood mitochondrial DNA content is related to HbA1c, fasting plasma glucose level and age of onset in type 2 diabetes mellitus

AIMS

Mitochondrial DNA (mtDNA) content is essential for maintaining normal mitochondrial function, and the mitochondrial function is critical for the production and the release of insulin in Type 2 diabetes mellitus. We investigated whether peripheral blood mtDNA content was reduced in Type 2 diabetes, and what were the major factors?

METHODS

The mtDNA content of peripheral blood in a sample of 147 Type 2 diabetes and 170 normal Chinese subjects was determined by amplification of the mitochondrial gene CYT-B and normalized by a nuclear DNA β-globin gene. Fasting plasma glucose, HbA(1c) , fasting plasma insulin and lipid profile (HDL-cholesterol, LDL-cholesterol, total cholesterol, triglyceride) were analysed with commercial kits on an automatic analyser.

RESULTS

In Type 2 diabetes group, the mean HbA(1c) was 62 mmol/mol (7.8%). Moreover, BMI, systolic blood pressure, diastolic blood pressure, fasting plasma glucose, LDL-cholesterol, triglyceride, fasting plasma insulin and homeostasis model assessment for insulin resistance were significantly higher in Type 2 diabetes group than that in control group. Peripheral blood mtDNA content was 24% lower than that in the controls (1.4 ± 0.5 vs. 1.8 ± 0.7, P < 0.001). The mtDNA content was negatively correlated with BMI, fasting plasma glucose, fasting plasma insulin, homeostasis model assessment for insulin resistance (P < 0.01), and age, triglyceride and LDL-cholesterol levels (P < 0.05); while positively correlated with HDL-cholesterol level (P < 0.05) in both groups. Stepwise regression analysis indicated that HbA(1c), fasting plasma glucose and age of onset were the major factors affecting the mtDNA content in the Type 2 diabetes group; however, BMI was the only variable associated with lower mtDNA content in control group.

CONCLUSION

Our results demonstrate that lower peripheral blood mtDNA content is associated with Type 2 diabetes in Chinese individuals, and HbA(1c), fasting plasma glucose and age of onset are the major factors affecting the mtDNA content.

Cloning of genes encoding colicin E2 in Lactococcus lactis subspecies lactis and evaluation of the colicin-producing transformants as inhibitors of Escherichia coli O157:H7 during milk fermentation

Colicin E2 (ColE2) is a proteinaceous bacterial toxin produced by some strains of Escherichia coli and other members of the Enterobacteriaceae that exhibits inhibitory activity against some strains of E. coli O157:H7. A 2.0-kb DNA fragment, containing the ColE2 structural gene ceaB and immunity gene ceiB from E. coli NCTC 50133 (pColE2-P9), was cloned into the lactococcal plasmid vector pNZ2103. The lysis gene, celB, was not cloned. The plasmid, pLR-E2, encoding the cloned genes was transformed into E. coli DH5α and Lactococcus lactis ssp. lactis LM0230 and PN-1 using electroporation. The bacteriocin ColE2 was expressed in transformants of both E. coli and L. lactis ssp. lactis. Secretion of ColE2 into media was verified by spot-on-lawn assays and measurement of ColE2 activity in the growth medium of transformants. The level of ColE2 produced by transformants containing pLR-E2 was similar to that produced by the parental strain, E. coli NCTC 50133 (pColE2-P9). Evaluation of a ColE2-producing transformant of L. lactis ssp. lactis as a starter culture revealed that, although ColE2 was produced by transformants and could be detected in milk during fermentation, the inhibitory activity of ColE2 against E. coli O157:H7 was significantly decreased in milk compared with buffered growth medium.

Expression and activation of β-adrenoceptors in the colorectal mucosa of rat and human

BACKGROUND

The functions of the distal colon are regulated by local and extrinsic neural pathways. In previous studies, we have found that dopamine (DA) and norepinephrine (NE) could evoke colonic ion transport by activating β-adrenoceptors. The present study aims to investigate the segmental differences in expression and activation of β-adrenoceptors in the distal colon in physiological and pathophysiological conditions.

METHODS

Real-time PCR, immunofluorescence, and Western blotting were used to detect the expression of β-adrenoceptors in the rat and human distal colon. Short-circuit current measurements (Isc) were used to assess the role of β-adrenoceptors in ion transport.

KEY RESULTS

DA and NE caused greater suppression of baseline Isc in distal colon adjacent to the rectum than in segments further away from the anus. These responses were inhibited by selective antagonists of β₁- and β₂-adrenoceptors, but not β₃-adrenoceptor. The expression levels of β₁- and β₂-adrenoceptors in colonic mucosa were higher in colorectum than the regions away from the anus of rats and humans. In wrap-restraint stress (2 h), DA-, NE-induced ΔIsc and the expression of β-adrenoceptors in the colorectum were significantly reduced. However, when endogenous catecholamines were depleted by 6-hydroxydopamine (75 mg kg(-1), i.p., 3 days), DA-, NE-induced ΔIsc as well as the expression of β-adrenoceptors were significantly enhanced in the rat colorectum but not in more proximal regions of the distal colon.

CONCLUSIONS & INFERENCES

β₁- and β₂-adrenoceptors are predominantly expressed in the colorectal mucosa. Perturbation of endogenous catecholamine levels influences the expression and activation of β-adrenoceptors in the colorectal region.

Giant enhancement of surface second-harmonic generation using photorefractive surface waves with diffusion and drift nonlinearities

Giant enhancement of second-harmonic generation (SHG) with 83.4%/W coversion efficiency is obtained, taking advantage of photorefractive surface waves with diffusion and drift nonlinearity. In this method, the self-bending induced by diffusion nonlinearity can be utilized at the surface and can solve the phase-mismatch problem in bulk due to beam self-bending. With drift nonlinearity, an applied external electric filed and background illumination can further constringe surface waves to the surface and consequently enhance SHG, which provides the possibility and flexibility of control.

Activation of submucosal 5-HT(3) receptors elicits a somatostatin-dependent inhibition of ion secretion in rat colon

BACKGROUND AND PURPOSE

5-Hydroxytryptamine (5-HT) is a key regulator of the gastrointestinal system and we have shown that submucosal neuronal 5-HT(3) receptors exerted a novel inhibitory effect on colonic ion transport. The aim of the present study was to investigate the precise mechanism(s) underlying this inhibitory effect.

EXPERIMENTAL APPROACH

Mucosa/submucosa or mucosa-only preparations from rat distal colon were mounted in Ussing chambers for measurement of short-circuit current (I(sc)) as an indicator of ion secretion. Somatostatin release was determined with radioimmunoassay. Intracellular cAMP content was measured with enzyme-linked immunoadsorbent assay (elisa). Immunohistochemical techniques were used to study the expression of 5-HT(3) receptors, somatostatin and somatostatin receptors in colonic tissue.

KEY RESULTS

In rat distal colonic mucosa/submucosa preparations, pretreatment with 5-HT(3) receptor antagonists enhanced 5-HT-induced increases in I(sc). However, in mucosa-only preparations without retained neural elements, pretreatment with 5-HT(3) receptor antagonists inhibited 5-HT-induced DeltaI(sc). Pretreatment with a somatostatin-2 (sst(2)) receptor antagonist in mucosa/submucosa preparations augmented 5-HT-induced DeltaI(sc). Combination of sst(2) and 5-HT(3) receptor antagonists did not cause further enhancement of 5-HT-induced DeltaI(sc). Moreover, both sst(2) and 5-HT(3) receptor antagonists enhanced 5-HT-induced increase in intracellular cAMP concentration in the mucosa/submucosa preparations. 5-HT released somatostatin from rat colonic mucosa/submucosa preparations, an effect prevented by pretreatment with 5-HT(3) receptor antagonists. Immunohistochemical staining demonstrated the presence of 5-HT(3) receptors on submucosal somatostatin neurons and of sst(2) receptors on colonic mucosa.

CONCLUSION AND IMPLICATIONS

Activation of neuronal 5-HT(3) receptors in the submucosal plexus of rat colon suppressed 5-HT-induced ion secretion by releasing somatostatin from submucosal neurons.

(2+1)D surface solitons in virtue of the cooperation of nonlocal and local nonlinearities

We introduce a type of (2+1)D surface soliton in virtue of the cooperation of nonlocal and local nonlinearities. Furthermore, taking advantage of diffusion and drift nonlinearity this type of surface soliton is demonstrated theoretically and experimentally in a storintium barium nitrate crystal. The dynamics behavior of the excitation and propagation of this type of surface soliton are studied using the beam-propagation method and the nonlinear equation of light rays.

Impacts of atmospheric anthropogenic nitrogen on the open ocean

Increasing quantities of atmospheric anthropogenic fixed nitrogen entering the open ocean could account for up to about a third of the ocean's external (nonrecycled) nitrogen supply and up to approximately 3% of the annual new marine biological production, approximately 0.3 petagram of carbon per year. This input could account for the production of up to approximately 1.6 teragrams of nitrous oxide (N2O) per year. Although approximately 10% of the ocean's drawdown of atmospheric anthropogenic carbon dioxide may result from this atmospheric nitrogen fertilization, leading to a decrease in radiative forcing, up to about two-thirds of this amount may be offset by the increase in N2O emissions. The effects of increasing atmospheric nitrogen deposition are expected to continue to grow in the future.

Recent developments in the understanding of nuclear protein import

The process of nucleocytoplasmic exchange of various macromolecules and metabolites between the nuclear and cytoplasmic compartment is crucial for cell function and survival. It is also closely involved with several pathogeneses including cancer and viral infections. Here, we will discuss the current understanding of the classical nuclear import pathway and the factors that are essential for this process.

Effects of dietary methionine and lysine sources on nutrient digestion, nitrogen utilization, and duodenal amino acid flow in growing goats

This study investigated the effects of supplementation of various sources of Met and Lys on nutrient digestion, N utilization, and duodenal AA flows in growing goats. Four 4-mo-old Liuyang Black wether goats were used in a 4 x 4 Latin square experiment and were assigned to 4 dietary treatments: (1) control, (2) control + lipid-coated Met-Zn chelate and Lys-Mn chelate (PML), (3) control + Met-Zn chelate and Lys-Mn chelate (CML), and (4) control + dl-Met, l-Lys-HCl, ZnSO(4).7H(2)O, and MnSO(4).H(2)O (FML). Compared with control, PML reduced (P < 0.05) ruminal NH(3) concentration, urinary N excretion, and plasma urea N concentration and increased (P < 0.05) the activity of ruminal endo-1,4-beta-d-glucanase and beta-glucosidase, the duodenal flow of N, N retention (g/d as well as % of absorbed N), the duodenal flows of Met, Lys, His, Val, and total essential AA, and plasma concentrations of Lys, Val, Phe, and total essential AA. Supplementing Zn-Met and Mn-Lys chelates had similar (P > 0.05) but lesser effects on these measures compared with PML, and the effects on most of the measures were not statistically significant (P > 0.05) when compared with control. Supplementing free-form Met and Lys had no effects compared with control (P > 0.05). The results indicate that lipid coating and chelating of AA provide a protection, and to a lesser extent by only chelating, of the AA from microbial degradation in the rumen and possibly has effects on rumen fermentation, which increases MP supply. This technology could improve productive performance and be of potential benefit to ruminant production if cost-effective products are developed.

T-shaped GaAs quantum-wire lasers and the exciton Mott transition

T-shaped GaAs quantum-wire (T-wire) lasers fabricated by the cleaved-edge overgrowth method with molecular beam epitaxy on the interface improved by a growth-interrupt high-temperature anneal are measured to study the laser device physics and fundamental many-body physics in clean one-dimensional (1D) systems. A current-injection T-wire laser that has 20 periods of T-wires in the active region and a 0.5 mm long cavity with high-reflection coatings shows a low threshold current of 0.27 mA at 30 K. The origin of the laser gain above the lasing threshold is studied with the high-quality T-wire lasers by means of optical pumping. The lasing energy is about 5 meV below the photoluminescence (PL) peak of free excitons, and is on the electron-hole (e-h) plasma PL band at a high e-h carrier density. The observed energy shift excludes the laser gain due to free excitons, and it suggests a contribution from the e-h plasma instead. A systematic micro-PL study reveals that the PL evolves with the e-h density from a sharp exciton peak, via a biexciton peak, to an e-h-plasma PL band. The data demonstrate an important role of biexcitons in the exciton Mott transition. Comparison with microscopic theories points out some problems in the picture of the exciton Mott transition.

Increasing COPD awareness

Early diagnosis and smoking cessation are the only available methods to stop the progression of chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate the effects of early detection of airflow limitation (AL) in a population with high risk for COPD, using spirometric screening. Smokers aged 40 yrs with a smoking history of 10 pack-yrs were invited to visit a local outpatient chest clinic for simple spirometry (forced expiratory volume in one second (FEV1) and forced vital capacity (FVC)). Smoking history was recorded, followed by smoking cessation advice relating the results of spirometry to the smoking behaviour. Subjects who did not fulfil the above criteria (younger and/or nonsmokers) were also screened. A total 110,355 subjects were investigated; they were aged 53.5+/-11.5 yrs and 58.2% were males. Of the total amount of subjects, 64% were current smokers, 25.1% were former smokers and 10.9% were lifelong nonsmokers. Spirometry tests were within normal values for 70.3%, and 20.3% showed signs of AL: this was mild in 7.6%, moderate in 6.7% and severe in 5.9%. The remaining 8.3% of subjects presented with a restrictive pattern of ventilatory impairment. Airflow limitation was found in 23% of smokers aged 40 yrs with a history of 10 pack-yrs. This study concluded that large-scale voluntary spirometry screening of the population with high risk for COPD detects a large number of subjects with AL.

Cutaneous smooth muscle tumors in the dog and cat

Cutaneous smooth muscle tumors may arise from arrector pili muscles and from smooth muscles of the dermal vasculature. This report describes histologic and immunohistochemical features of eight arrector pili hamartomas in 8 dogs, 15 piloleiomyomas in 10 dogs and 3 cats, 10 piloleiomyosarcomas in 9 dogs and 1 cat, 1 angioleiomyoma in 1 cat, and 9 angioleiomyosarcomas in 6 dogs and 3 cats. Hamartomas and tumors arising from arrector pili muscles preferentially originated from the dorsal trunk. 5/5 (100%) arrector pili hamartomas, 10/12 (83%) piloleiomyomas, 4/5 (80%) piloleiomyosarcomas, 1/1 (100%) angioleiomyoma, and 6/7 (86%) angioleiomyosarcomas were positive for smooth muscle actin. 5/5 (100%) arrector pili hamartomas, 10/12 (83%) piloleiomyomas, 4/5 (80%) piloleiomyosarcomas, 1/1 (100%) angioleiomyoma, and 1/7 (14%) angioleiomyosarcomas were positive for desmin. Two incompletely excised canine angioleiomyosarcomas recurred locally. Metastases were not reported.

Teratogenic effects of chronic ingestion of high levels of vitamin A in cats

High concentrations of retinoids occur in some commercial cat food formulations as a result of the use of animal liver as an ingredient. Our objective was to study the teratogenic potential of dietary vitamin A in cats. We investigated the incidence of birth defects in kittens of queens given diets with retinyl acetate concentrations of 6000, 306000, or 606000 retinol equivalents (RE)/kg diet (control, 306K, or 606K groups, respectively) for approximately 3 years [1 RE=1 micro g retinol=3.3 International Units (IU)]. Each group comprised 12-15 age-matched, nulliparous domestic short-haired queens that were exposed to toms. There were a total of 396 kittens born in 97 litters. Pregnancy rate, number of kittens per gestation and gestations per year were not significantly different among treatment groups. A total of 2, 5 and 11 malformed kittens occurred in the control, 306K and 606K groups, respectively. Malformations included cleft palate, cranioschisis, foreshortened mandible, stenotic colon, enlarged heart and agenesis of the spinal cord and small intestine, which are typical foetal defects consistent with ingestion of excess retinoids in other species. This study demonstrated that a concentration of 306000 RE/kg diet has a potential for causing birth defects in the kittens.

Increased peritoneal membrane permeability is associated with abnormal peritoneal surface layer

OBJECTIVES

We recently showed that the peritoneal surface layer may be an important barrier in modulating peritoneal membrane permeability. In the present study, we investigated the relationship between an increased peritoneal transport rate and the peritoneal surface layer.

METHODS

Male Sprague-Dawley rats (n = 8) received intraperitoneal injections of 4.25% glucose dialysate daily for 1 week. Forty-eight hours after the last injection, a 4-hour dwell study using 25 mL 4.25% glucose dialysate was performed in each rat. The results were compared with those from control rats that received no intraperitoneal injections (n = 8). The peritoneal fluid and small-solute transport characteristics were evaluated. The peritoneal surface layer was studied using an electron microscope. The phospholipids content of the dialysate was also evaluated.

RESULTS

Peritoneal fluid removal was significantly reduced in the daily injection group (30.6 +/- 1.3 mL) as compared with the control group (38.2 +/- 0.6 mL). The peritoneal fluid absorption rate and small-solute transport rate were also significantly higher in the daily injection group as compared with the control group. The amounts of phospholipids in the dialysate were significantly lower in the daily injection group--especially the quantity of phosphatidylcholine. However, lysophosphatidylcholine increased significantly in the daily injection group. Electron microscopy showed that the peritoneal surface layer was almost completely gone in the daily injection group, but that a dense and thick (average 4 microm) peritoneal surface layer was present on the top of the mesothelial cells in the control group.

CONCLUSIONS

Our results suggest that daily injection of hypertonic glucose dialysate significantly increased the peritoneal transport rate. The increased peritoneal transport rate was associated with a significant reduction in the peritoneal surface layer and the phospholipids content of the dialysis effluent.

Methods to improve the preservation of peritoneal tissues

Peritoneal mesothelial cells are easily detached during conventional tissue processing, which may result in artifacts in peritoneal tissue examination. Therefore, in the present study, we investigated several methods to improve the preservation of the anterior parietal peritoneal tissues. Peritoneal tissue from the anterior abdominal wall was taken from each of 5 rats killed for the experiment. Tissue samples were immediately treated by one of these methods: (1) fixed with 10% formaldehyde; (2) fixed with Bouin's solution; (3) fixed with Helly's solution. After fixation, the samples were dehydrated with one of (a) ethanol, 1 hour in each step; (b) ethanol, 15 minutes in each step; or (c) tertiarybutyl alcohol. Five sections were taken from each tissue and stained with hematoxylin and eosin. The quality of tissue fixation was evaluated by image analysis. Peritoneal mesothelial cells were well preserved after fixation with Helly's solution or Bouin's solution. With 10% formaldehyde, about 40% of the mesothelial cells were lost. Dehydration with ethanol--especially long-duration dehydration--increased the loss. However, dehydration with tertiarybutyl alcohol avoided the increased loss of mesothelial cells. The submesothelial extracellular matrix was well preserved with Bouin's solution, but not with the other fixatives. Our results suggest that fixation with formaldehyde and dehydration with ethanol results in significant loss of peritoneal mesothelial cells and submesothelial extracellular matrix in peritoneal tissues. Fixation with Bouin's solution and dehydration with tertiary-butyl alcohol may be a better method of preserving peritoneal tissue.

Prospective study of Helicobacter pylori eradication therapy in stage I(E) high-grade mucosa-associated lymphoid tissue lymphoma of the stomach

PURPOSE

High-grade mucosa-associated lymphoid tissue (MALT) lymphomas of the stomach are generally believed to be Helicobacter pylori-independent, autonomously growing tumors. However, anecdotal cases of regression of high-grade lymphomas after the cure of H pylori infection had been described. The present prospective study was conducted to evaluate the effect of anti-H pylori therapy in stage I(E) high-grade gastric MALT lymphomas.

PATIENTS AND METHODS

Sixteen patients with H pylori infection and stage I(E) gastric high-grade MALT lymphoma consented to a brief antibiotic therapy as first-line treatment from June 1995 through April 2000. Then, patients underwent intensive endoscopic follow-up examinations (+/- endoscopic ultrasonography) with biopsy to evaluate tumor response. Patients with significant improvement of gross lesions that accompanied regression of large cells were followed up without additional treatment. Patients without significant improvement were immediately referred to systemic chemotherapy.

RESULTS

Eradication of H pylori was achieved in 15 patients and was accompanied by rapid gross tumor regression and disappearance of large cells in 10. All 10 of these patients with early response had subsequent complete histologic remission of lymphoma. The complete remission rate was 62.5% (95% confidence interval, 35.8% to 89.1%). The response rate was not affected by the tumor grading (proportion of large blast cells within the tumor) but was adversely affected by the depth of tumor invasion. At a median follow-up of 43.5 months (range, 21.1 to 67.4 months), all 10 of these patients remained lymphoma-free. The median duration of complete response was 31.2 months (range, 14.4 to 49.1 months).

CONCLUSION

These results suggest that high-grade transformation is not necessarily associated with the loss of H pylori dependence in early-stage MALT lymphomas of the stomach.

Biotransformation of p-toluic acid in anoxic estuarine sediments under a CO2 or N2/H2 atmosphere

The composition of the headspace gas affected the growth dynamics of microbial populations and the biotransformation pattern of p-toluic acid in anoxic estuarine sediments. Under CO2 atmosphere, p-toluic acid was transformed by the sediment microorganisms without a lag period, while under N2/H2 atmosphere, p-toluic acid was transformed after a lag period of 55 days. Under the N2/H2 atmosphere, the methanogen population, following a rapid increase of almost two orders of magnitude, remained at a high level until just before the onset of biotransformation. We hypothesize that during the lag period, the hydrogenotrophic methanogens were removing the H2, a step which is essential before the reaction can be exergonic. Acetogenic bacteria did not initiate decarboxylation as the first step of biotransformation under either atmosphere. Neither the methanogens nor the acetogenic bacteria appeared to be directly involved in the biotransformation of p-toluic acid under either atmosphere. Under the CO2 atmosphere, biotransformation of p-toluic acid involved sulfate-reducing bacteria, while under N2/H2, both sulfate-reducing bacteria and other eubacteria were involved.

[Study of acute supratentorial and infratentorial localized lesions by transcranial Doppler]

OBJECTIVE

To evaluate the correlation between increased intracranial pressure in supratentorial, infratentorial and TCD parameters of basal arteries.

METHODS

Sixteen New Zealand white rabbits were randomly divided into two groups: supratentorial group and infratentorial group. Intracranial pressures were raised after inflation of a preplaced epidural balloons. TCD parameters of the BA, rMCA were examined at intervals of 15 minutes after inflation of the balloon. ICP, ASP, HR, R were also recorded simultaneously.

RESULTS

1. The normal spectra of BA were characterized by a high-resistance, low-flow waveform. 2. At the 0.4 ml, 0.5 ml balloon volume level, ICP in supratentorial group was significantly increased than that in infratentorial group; 3. The correlation between ICP and MCA's TCD parameters were better than that between ICP and BA's TCD parameters in the supratentorial group. In the infratentorial group, the correlation between ICP and BA's TCD parameters were better than that between ICPs and MCA's TCD.

CONCLUSIONS

1. There are intracranial pressure gradients in mass lesions, so fibroptic probe should be placed at the place where the mass lesion takes place. 2. To perform non-invasive ICP monitoring by TCD, the basal artery should be chosen according to the mass lesions.

[Changes in somatosensory evoked potentials and brainstem auditory evoked potentials during acute intracranial hypertension in rabbits]

OBJECTIVE

To study the changes in somatosensory evoked potentials (SEPs) and brainstem auditory evoked potentials (BAEPs) during intracranial hypertension.

METHOD

A rabbit model of acute intracranial hypertension was developed. Thirty New Zealand rabbits were divided into 3 group. Both Group A and B were groups with intracranial hypertension; Group C was the control group. In Group A, balloons were placed to the right parietal lobe beneath the dura mater; in Group B, to temporal at the middle fossa near the brainstem.

RESULT

(1) In Group A, when ICP rose to (1.48 +/- 0.35) kPa, P1 amplitude of SEPs was significantly changed, whereas latencies of Wave IV, V, and VII of BAEPs were prolonged when ICP rose to (9.40 +/- 1.60) kPa. In group B, P1 amplitude of SEPs was changed when ICP reached (8.10 +/- 1.25) kPa, and latency of Wave III of BAEPs was prolonged when ICP rose to (3.11 +/- 0.80) kPa. (2) P1 amplitude increased with ICP value when the balloon volume increased from V = 0.0 ml, ICP = (0.43 +/- 0.10) kPa to V = 0.4 ml, ICP = (2.44 +/- 0.65) kPa and then decreased afterward.

CONCLUSIONS

(1) Changes in SEPs and BAEPs relate to not only ICP value but also the location of the balloon. (2) With the increasing of ICP, P1 amplitude increases firstly and then decreases.

Anaerobic biodegradation of DDT residues (DDT, DDD, and DDE) in estuarine sediment

The potential for anaerobic biodegradation of 1,1,1-trichloro-2,2-bischlorophenylethane (DDT), 1,1-dichloro-2,2,-bischlorophenylethane (DDD), and dichlorodiphenylchloroethylene (DDE) in anoxic sediment slurries collected from the Keelung River was investigated in this study. o,p'- and p,p'-DDT were dechlorinated to o,p'- and p,p'-DDD, respectively, and then transformed to other compound(s). 1-Chloro-2,2-bis (p-chlorophenyl) ethylene (DDMU) and trace amount of dichlorobenzophenone (DBP) were detected in sediment slurries amended with p,p'-DDT or p,p'-DDD. DDMU was also detected in sediment slurries amended with p,p'-DDE. The relative transformation rates for both o,p'- and p,p'-isomers of DDT, DDD, and DDE were DDT>DDD>DDE. Re-addition of DDT, DDD, or DDE to the sediment slurries after initial removal enhanced the respective dechlorination rates. The transformation rates of the p,p'-isomers of both DDT and DDD were faster than those of the respective o,p'-isomers. p,p'-DDT dechlorination in the p,p'-DDT-adapted sediment slurries were inhibited by the addition of molybdate, or molybdate plus sulfate, but not inhibited by the addition of sulfate. Addition of bromoethane-sulfonic acid (BESA) slightly inhibited p,p'-DDT dechlorination. Non-adapted sediment slurries lost the ability to dechlorinate pentachlorophenol during adaptation to p,p'-DDT. p,p'-DDD was the major transformation product of p, p'-DDT in 3,4,4',5-tetrachlorobiphenyl-adapted sediment slurries, which suggested that the microbial community in the 3,4,4',5-CB-adapted sediment was unable to remove chlorine from the aromatic rings of p,p'-DDT.

Comparison of three chronic dialysis models

The chronic peritoneal dialysis model is important for understanding the pathophysiology of peritoneal transport and for studying biocompatibility of peritoneal dialysis solutions. In this study, we compared three different chronic peritoneal dialysis models. A peritoneal catheter was placed in 23 male Sprague-Dawley rats, 12 of which had an intact omentum (model 1) and 11 of which received an omentectomy (model 2). Seven other rats, without a catheter, received a daily intraperitoneal injection (model 3). Each rat received a daily infusion of 25 mL of 3.86% glucose dialysis solution either through the catheter (models 1 and 2) or through injection (model 3) for 4 weeks. Then, a 4-hour dwell study using 3.86% glucose solution with an intraperitoneal volume marker and frequent dialysate and blood sampling was performed in each rat. The intraperitoneal volume was significantly lower in all the dialysis groups as compared to a control group (n = 6) in which the rats had no chronic dialysate exposure. The peritoneal fluid absorption rate, as well as the direct lymphatic absorption rate, was significantly higher in the three dialysis groups as compared to the control group. In general, no significant differences were seen in any of the parameters among the three dialysis models. Owing to catheter obstruction, three rats in model 1 and four rats in model 2 were lost during dialysis. Histological examination showed no significant differences among the three dialysis groups. Our results suggest that omentectomy may not be necessary in the chronic peritoneal dialysis model when using dialysate infusion and no drainage. Based on the present study, we think that perhaps model 1 may be the method of choice to test new peritoneal dialysis solutions. However, owing to its simplicity, model 3 could also be used if great care is taken to avoid puncturing the intestine or injecting into the abdominal wall.

Transgenic complementation of leptin-receptor deficiency. I. Rescue of the obesity/diabetes phenotype of LEPR-null mice expressing a LEPR-B transgene

Mice homozygous for the Leprdb3J (db3J) mutation are null for all known isoforms of the leptin receptor (LEPR). These animals are obese, hyperphagic, cold intolerant, insulin resistant, and infertile. Mice homozygous for the Leprdb (db) mutation (lacking the B isoform only) have the same phenotype as db3J animals. To better understand the function(s) of the LEPR isoforms in vivo, we generated db3J/db3J and db/db mice bearing a transgene (neuron-specific enolase [NSE]-Rb) expressing the B isoform of LEPR, the isoform capable of activating the signal transducer and activator of transcription (STAT) pathway, under the control of the neuron-specific enolase enhancer/promoter. The NSE-Rb transgene was expressed in the brain, with low levels of expression in adrenals, testis, and white adipose tissue. LEPR-B transgene expression in NSE-Rb db3J/db3J mice partially corrected the increased fat mass, hyperphagia, and glucose intolerance while restoring fertility in males and rescuing the cold intolerance in both sexes. The body weights of NSE-Rb transgenic mice that possessed the full complement of short LEPR isoforms (NSE-Rb db/db mice) were similar to those of NSE-Rb db3J/db3J mice, suggesting that the short LEPR isoforms play little role in body weight regulation. Based on quantitative analysis of hypothalamic neuropeptide gene expression in the transgenic animals, we infer full restoration of leptin sensitivity to proopiomelanocortin (POMC) neurons, partial correction of leptin sensitivity in agouti gene-related protein (AGRP)/neuropeptide Y (NPY) neurons, and a lack of effect on leptin sensitivity of melanin concentrating hormone neurons. Thus, hypothalamic POMC and AGRP/NPY neurons are primary candidates as the mediators of the effects of the NSE-Rb transgene on energy homeostasis, ingestive behavior, the neuroendocrine system, and glucose metabolism.