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.

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.

[Dose-response relationship between noise kurtosis and noise-induced hearing loss]

Objective: To analyse the dose-response relationships between the kurtosis metric of noise and noise-induced hearing loss (NIHL) and study the role of kurtosis in the evaluation of NIHL associated with non-Gaussian noise. Methods: From January 2012 to December 2017, a total of 1869 workers in seven manufacturing industries were selected as the study subjects. The basic data of the workers were investigated by questionnaire, personal noise waveform was collected for a long time, and pure tone hearing threshold was tested. The 8-hour continuous equivalent A sound level (L(Aeq, 8 h)) , cumulative noise exposure (CNE) and kurtosis structure indexes were calculated. The dose-response relationships between kurtosis and NIHL were analyzed by stratification analysis method, which controlled the influence of CNE, L(Aeq, 8 h), exposure duration, age and sex on hearing loss using high-frequency noise-induced permanent threshold shift (NIPTS(346)) and high-frequency noise-induced hearing loss (HFNIHL) as outcome indicators. Results: When CNE was <90 dB (A) ·year and ≥100 dB (A) ·year, NIPTS(346) in the extremely high kurtosis group was significantly greater than that in the Gaussian kurtosis, low kurtosis and medium kurtosis group (P<0.05) . In the workers exposed to L(Aeq, 8 h)<85 dB (A) and ≥94 dB (A) , NIPTS(346) in the extremely high kurtosis group was significantly greater than that in the Gaussian kurtosis group (P<0.05) . Among workers under the age of 50 or male workers, NIPTS(346) in the extremely high kurtosis group was significantly greater than that in the Gaussian kurtosis, low kurtosis and medium kurtosis group (P<0.05) . Kurtosis was positively correlated with NIPTS(346) (r=0.121, P<0.05) . When CNE was <100 dB (A) ·year, the detection rate of HFNIHL increased with the increase of kurtosis level (P<0.01) . Logistic regression analysis showed that kurtosis was an important influencing factor for HFNIHL (OR=1.321) . Conclusion: Kurtosis has a dose-response relationship with the detection rate of HFNIHL in noise exposed workers, and noise kurtosis is an influencing factor of NIHL.

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.

Impact of different regenerative techniques and materials on the healing outcome of endodontic surgery: a systematic review and meta-analysis

BACKGROUND

Regenerative techniques are increasingly applied in endodontic surgery, but different materials used in regenerative techniques may have varying impacts on wound healing.

OBJECTIVES

This study evaluated the effects of different regenerative techniques and materials on the outcome of endodontic surgery.

PARTICIPANTS

patients with persistent periapical lesions, treated with root-end surgery.

CONTROL

endodontic surgery without the use of regenerative techniques/materials.

INTERVENTION

endodontic surgery with the use of regenerative techniques/materials.

OUTCOME

combined clinical and radiographic results.

METHODS

PubMed, Web of Science, Embase, SinoMed and the CENTRAL Cochrane were searched up to 10th July 2020, followed by a manual search. Detailed eligibility criteria were applied. Cochrane's risk-of-bias tool 2.0 was used to assess the risk of bias of the eligible studies. Meta-analysis was conducted using RevMan software. Subgroup analyses were performed based on the regenerative materials used in endodontic surgery.

RESULTS

Eleven eligible randomized controlled trials (RCTs) were included in the meta-analysis: two had a low risk of overall bias, and nine had some concerns of overall bias. Generally, the use of regenerative techniques significantly improved the outcome of endodontic surgery (risk ratio [RR]: 0.42; 95% confidence interval [CI], 0.26-0.68; P < 0.001). On subgroup analysis, the use of expanded polytetrafluoroethylene (e-PTFE) membranes alone had no added benefits (RR: 2.00; 95% CI, 0.22-18.33; P = 0.54). The application of collagen membranes or autologous platelet concentrates (APCs) alone was associated with a trend for better outcomes (RR: 0.51; 95% CI, 0.20-1.25; P = 0.14) (RR: 0.55; 95% CI, 0.18-1.71; P = 0.30). The combined use of collagen membranes and bovine-derived hydroxyapatite significantly improved the outcome (RR: 0.35; 95% CI, 0.17-0.75; P = 0.007).

DISCUSSION

This systematic review evaluated the effects of collagen membranes, e-PTFE membranes, APCs and bone grafting materials, providing detailed information about the risks and benefits of using each regenerative technique/material or its combination in endodontic surgery.

CONCLUSIONS

Regenerative techniques improve periapical lesion healing after endodontic surgery. The combined use of collagen membranes and bovine-derived hydroxyapatite may be beneficial as an adjunct to endodontic surgery. In contrast, the positive efficacy of e-PTFE membranes or APCs alone remains doubtful.

[Risk factors for early rebleeding after esophageal variceal ligation in patients with liver cirrhosis]

Objective: To investigate the risk factors for early rebleeding after esophageal variceal ligation (EVL) through a multicenter retrospective study. Methods: A total of 3289 patients who were hospitalized and underwent EVL in 17 upper second-class hospitals or hospitals of higher classes from January 1999 to May 2015 were collected and screened according to the exclusion criteria. A total of 2531 patients were screened out, and a retrospective analysis was performed for their clinical data including age, sex, endoscopic findings, and results of laboratory examination (liver function, biochemical results, routine blood test, and coagulation function) to collect related data. According to the presence or absence of rebleeding within 1 month after EVL, the patients were divided into rebleeding group and non-rebleeding group. SPSS22.0 software was used for independent t-test and one-way analysis of variance, and P < 0.05 was considered statistically significant. Results: In the 2531 patients who underwent EVL, the rate of early rebleeding after EVL was 6.6%, and the mortality rate was 12.0%. The results showed that sex (P = 0.014), number of veins with varices (P = 0.203), prothrombin time (P = 0.001), prothrombin activity (P = 0.014), albumin (P = 0), total bilirubin (P = 0.011), aspartate aminotransferase (P = 0.004), white blood cell count (P = 0.342), hepatic encephalopathy (P = 0.021), ascites (P = 0.027), Child-Pugh class (P = 0), Child-Pugh score (P = 0), glue injection for gastric varices (P = 0.521), gastric varices (P = 0.32), shunt (P = 0.174), number of ligation points (P = 0.001), number of ligation times (P = 0.024), number of times of hematemesis before treatment (P = 0), number of times of tarry stool (P = 0.008), and volume of blood in hematemesis before treatment (P = 0) were risk factors for early rebleeding after EVL. The regression analysis showed that male sex, a Child-Pugh score of >7.2, and volume of blood in hematemesis before treatment were independent risk factors for early rebleeding after EVL, while an albumin concentration of > 31.5 g/L was the protective factor. Conclusion: EVL has a good therapeutic effect in esophageal variceal rebleeding. Among all the factors analyzed, male sex, a Child-Pugh score of > 7.2, and volume of blood in hematemesis before treatment are independent risk factors for early rebleeding after EVL, and an albumin concentration of > 31.5 g/L is a protective factor.

First Report of Pantoea anthophila Causing Soft Rot Disease in Clausena lansium (Wampee) in China

Clausena lansium, also known as wampee (Clausena wampi), is a plant species native to China, Vietnam, the Philippines, Malaysia, and Indonesia, where it is widely cultivated, and also grown in India, Sri Lanka, Queensland, Florida, and Hawaii, but less frequently (3). The fruit can be consumed fresh or made into juice, jam, or succade. In summer to fall 2014, a soft rot disease was found in a wampee planting region in Yunan County, Guangdong Province, China. On Sept. 18, we collected diseased samples from a wampee orchard with about 20% disease incidence. The infected fruit initially showed pinpoint spots on the peel, water-soaked lesions, and light to dark brown discoloration. Spots expanded in 2 days, and tissues collapsed after 5 days. Severely affected fruit showed cracking or nonodorous decay. Five diseased samples were collected, and causal agents were isolated from symptomatic tissues 1 cm under the peel after surface sterilization in 0.3% NaOCl for 10 min and rinsing in sterile water three times. Tissues were placed on a Luria Bertani (LB) plate for culture. Ten representative isolates were selected for further characterization. No colony was isolated from healthy tissues. Colonies were round, smooth, with irregular edges, and produced a yellow pigment in culture. Biolog identification (Version 4.20.05) showed that all strains were gram negative, negative for indole production, and utilized glucose, maltose, trehalose, sucrose, D-lactose, and pectin but not sorbitol or gelatin. The isolates were identified as Pantoea agglomerans (SIM 0.69). Multilocus sequence analysis (MLSA) was conducted for rapid classification of the strains. Sequences of atpD, gyrB, infB, and rpoB were amplified using corresponding primers (2). All sequences of the 10 isolates were identical in each gene. BLASTn was performed, and maximum likelihood trees based on the concatenated nucleotide sequences of the four genes were constructed using MEGA6. Bootstrap values after 1,000 replicates were expressed as percentages. Results showed that the tested strain named CL1 was most homologous to P. anthophila, with 98% identity for atpD (KM521543), 100% for gyrB (KM521544), infB (KM521545), and rpoB (KM521546). The 16S rRNA sequence (KM521542) amplified by primers 27f and 1492r shared 99% identity with that of P. anthophila M19_2C (JN644500). P. anthophila was previously reclassified from P. agglomerans (3); therefore, we suggest naming this wampee pathogen P. anthophila. Subsequently, 10 wampee fruits were injected with 20 μl of bacterial suspension (1 × 10⁸ CFU/ml) of strains CL1 and CL2, respectively, and another 10 were injected with 20 μl of LB medium as controls, all kept at 28°C for 4 days. Symptoms similar to those of natural infections were observed on inoculated fruits but not on the negative controls. Bacteria were isolated from diseased tissues and further identified as P. anthophila by gyrB sequencing. P. anthophila was reported to naturally infect balsam and marigold (1,2). To our knowledge, this is the first report of P. anthophila naturally causing soft rot disease and cracking on C. lansium (wampee). References: (1) C. Brady et al. Syst. Appl. Microbiol. 31:447, 2008. (2) C. Brady et al. Int. J. Syst. Evol. Microbiol. 59:2339, 2009. (3) J. Morton. Fruits of Warm Climates. Echo Point Books & Media, Miami, FL, 1987.

Genetic diversity and relationships among accessions of five crested wheatgrass species (Poaceae: Agropyron) based on gliadin analysis

Agropyron Gaertn. is the most important genus in Triticeae (Poaceae), which includes many forage grasses with high economic value. The genetic diversity and relationships of 36 accessions from five crested wheatgrass species were analyzed by gliadin markers. A total of 54 product bands were detected after acid polyacrylamide gel electrophoresis (A-PAGE), of which 100% were polymorphic. The genetic similarity coefficient based on Nei-Li's method ranged from 0.065 to 0.755 with an average of 0.451. The Shannon diversity information index showed that there was a high level of genetic diversity among the accessions. An unweighted pair group method with arithmetic average (UPGMA) dendrogram was constructed based on the Nei-Li's genetic similarity coefficients, which showed the phylogenetic relationships among accessions of different species. Analysis of molecular variance (AMOVA) showed that the proportion of variance explained by inter- and intraspecific variance was 9.34 and 90.66%, respectively, which revealed that the genetic variations within species were higher than the variations among species. Based on pairwise genetic distances (ΦST) among species, the cluster analysis indicated that A. mongolicum had a low-affinity relationship with other species, while A. fragile showed a close relationship with A. cristatum ssp pectinatum. Finally, the implications of the results for the taxonomy of Agropyron were discussed.

First Report of Bacterial Foot Rot of Rice Caused by a Dickeya zeae in China

A bacterial disease of rice, bacterial foot rot, was found in Guangdong Province, China in September 2011, with an incidence about 10%. The typical symptom was a dark brown decay of the tillers. In the early stages of the disease, a brown sheath rot seemed to spread from the ligulae regions. The lesions quickly extended down to the nodes, culms, and finally to the crowns. Neighboring tillers of the same crown were invaded systemically, causing foot rot symptoms. A soft rot with an unpleasant odor developed in young tissues of infected tillers. In the advanced stage, many tillers decayed, so that entire diseased plants could easily be pulled from the soil. Six diseased samples were collected and bacteria were isolated from the edge of symptomatic tissues, after samples were sterilized in 0.3% NaOCl for 10 min, rinsed in sterile water three times, and placed on nutrient agar (beef extract 3 g, yeast extract 1 g, peptone 5 g, glucose 10 g, agar 16 g, distilled water 1 L, pH 6.8 to 7.0). For identification, a total of 12 representative isolates were selected. All strains were Gram negative, grew at 37°C, were positive for indole production, and utilized malonate, glucose, and sucrose, but not glucopyranoside, trehalose, or palatinose. Biolog identification (Version 4.20.05, Hayward, CA) identified isolate EC1 as Pectobacterium chrysanthemi (SIM 0.827), which has since been transferred to genus Dickeya. PCR was used to amplify the 16S rDNA gene with primers 27f and 1492r, the dnaX gene with primers dnaXf and dnaXr (2), and the gyrB gene with primers gyrBf1 (5'-ATGTCGAATTCTTATGACTCCTC-3') and gyrB-r1 (5'-TCARATATCRATATTCGCYGCTTTC-3'), which were designed based on published gyrB gene sequences of genus Dickeya. A BLASTn search of all three loci [16S rDNA (JQ284040), dnaX (JQ284041), and gyrB (JQ284042)] revealed that EC1 had 100% sequence identify to Dickeya zeae [16S rDNA (AB713560), dnaX (AB713593), gyrB (AB713635)]. Pathogenicity tests were conducted by injecting 10 rice seedlings with 100 μl of the bacterial suspension (1 × 10⁸ CFU/ml) in the stem base, and an additional 10 rice seedlings were injected with 100 μl of sterile water as negative controls. Inoculations were carried out in a greenhouse at 28 to 32°C and 90% relative humidity. Foot rot symptoms identical to those described above were observed after 7 days on inoculated plants, but not on the negative controls. The bacterium was reisolated from the lesions and had 100% sequence identity for all three loci to EC1. Previously, similar symptoms were reported on rice in Guangdong province of China, and the causal agent was identified as Erwinia chrysanthemi (1). To our knowledge, this is the first report of D. zeae causing foot rot disease on rice in China. References: (1) Q. G. Liu et al. J. South China Agric. Univ. 18:128, 1997. (2) M. Sławiak et al. Eur. J. Plant Pathol. 125:245, 2009.

Intrahypothalamic estradiol modulates hypothalamus-pituitary-adrenal-axis activity in female rats

Estrogen plays an important role in the regulation of the hypothalamus-pituitary-adrenal (HPA)-axis, but the neuroendocrine pathways and the role of estrogen receptor (ER) subtypes involved in specific aspects of this interaction remain unknown. In a first set of experiments, we administered estradiol (E2) intravenously, intracerebroventricularly, and by intrahypothalamic microdialysis to ovariectomized rats to measure plasma corticosterone (CORT) concentrations from carotid artery blood. Systemic infusion of E2 did not increase plasma CORT, but intracerebroventricular E2 induced a 3-fold CORT increase (P = 0.012). Local E2 infusions in the hypothalamic paraventricular nucleus (PVN) significantly increased plasma CORT (P < 0.001). A similar CORT increase was seen after PVN infusion of the ERα agonist propylpyrazoletriol, whereas the ERβ agonist diarylpropiolnitrile had no effect. In a second set of experiments, we investigated whether E2 modulates the HPA-axis response to acute stress by administering E2 agonists or its antagonist ICI 182,780 into the PVN during restraint stress exposure. After 30 min of stress exposure, plasma CORT had increased 5.0-fold (P < 0.001). E2 and propylpyrazoletriol administration in the PVN enhanced the stress-induced plasma CORT increase (8-fold vs. baseline), whereas ICI 182,780 and diarylpropiolnitrile reduced it, as compared with both E2 and vehicle administration in the PVN. In conclusion, central E2 modulates HPA-axis activity both in the basal state and during restraint stress. In the basal condition, the stimulation is mediated by ERα-sensitive neurons, whereas during stress, it is mediated by both ERα and ERβ.

Hrd1 facilitates tau degradation and promotes neuron survival

Intraneuronal accumulation of abnormal phosphorylated tau (p-tau) is a molecular pathology in many neurodegenerative tauopathies, including Alzheimer's disease (AD) and frontotemporal dementia with parkinsonism-linked to chromosome 17 (FTDP-17). However, the underlying mechanism remains unclear. Here, we showed an inverse relationship between endoplasmic reticulum membrane ubiquitin ligase (E3) Hrd1 expression and p-tau accumulation in the hippocampal neurons of AD, and proposed that Hrd1 may be a negative regulator of p-tau. This notion was further supported by in vitro study demonstrating that Hrd1 interacted with tau and promoted the degradation of total tau and p-tau as well. The degradation of tau depended on its Hrd1 E3 activity. Knockdown of endogenous Hrd1 with siRNA stabilized tau levels. In addition, inhibition of proteasome maintained tau level and increased Hrd1-mediated tau ubiquitination, suggesting the proteasome was involved in tau/p-tau degradation. Over-expression of Hrd1 significantly alleviated tau cytotoxicity and promoted cell survival. These results indicated that Hrd1 functions as an E3 targeting tau or abnormal p-tau for proteasome degradation. The study provides an important insight into the molecular mechanisms of human tauopathies.

First Report of a Soft Rot of Phalaenopsis aphrodita Caused by Dickeya dieffenbachiae in China

Phalaenopsis orchids, originally from tropical Asia, are mainly planted in Thailand, Singapore, Malaysia, the Philippines, and Taiwan and have gained popularity from consumers all over the world. The cultivation area of Phalaenopsis orchids has been rising and large-scale bases have been established in mainland China, especially South China because of suitable environmental conditions. In September 2011, a soft rot of Phalaenopsis aphrodita was found in a Phalaenopsis planting base in Guangzhou with an incidence of ~15%. Infected plants initially showed water-soaked, pale-to-dark brown pinpoint spots on leaves that were sometimes surrounded by a yellow halo. Spots expanded rapidly with rising humidity and temperatures, and in a few days, severely extended over the blade with a light tan color and darker brown border. Lesions decayed with odorous fumes and tissues collapsed with inclusions exuding. The bacterium advanced to the stem and pedicle. Finally, leaves became papery dry and the pedicles lodged. Six diseased samples were collected, and bacteria were isolated from the edge of symptomatic tissues after sterilization in 0.3% NaOCl for 10 min, rinsing in sterile water three times, and placing on nutrient agar for culture. Twelve representative isolates were selected for further characterization. All strains were gram negative, grew at 37°C, were positive for indole production, and utilized malonate, glucose, and sucrose but not glucopyranoside, trehalose, or palatinose. Biolog identification (version 4.20.05, Hayward, CA) was performed and Pectobacterium chrysanthemi (SIM 0.868) was confirmed for the tested isolates (transfer to genus Dickeya). PCR was used to amplify the 16S rDNAgene with primers 27f and 1492r, dnaX gene with primers dnaXf and dnaXr (3), and gyrB gene with primers gyrBf (5'-GAAGGYAAAVTKCATCGTCAGG-3') and gyrB-r1 (5'-TCARATATCRATATTCGCYGCTTTC-3') designed on the basis of the published gyrB gene sequences of genus Dickeya. BLASTn was performed online, and phylogeny trees (100% bootstrap values) were created by means of MEGA 5.05 for these gene sequences, respectively. Results commonly showed that the representative tested strain, PA1, was most homologous to Dickeya dieffenbachiae with 98% identity for 16S rDNA(JN940859), 97% for dnaX (JN989971), and 96% for gyrB (JN971031). Thus, we recommend calling this isolate D. dieffenbachiae PA1. Pathogenicity tests were conducted by injecting 10 P. aphrodita seedlings with 100 μl of the bacterial suspension (1 × 10⁸ CFU/ml) and another 10 were injected with 100 μl of sterile water as controls. Plants were inoculated in a greenhouse at 28 to 32°C and 90% relative humidity. Soft rot symptoms were observed after 2 days on the inoculated plants, but not on the control ones. The bacterium was isolated from the lesions and demonstrated identity to the inoculated plant by the 16S rDNA sequence comparison. Previously, similar diseases of P. amabilis were reported in Tangshan, Jiangsu, Zhejiang, and Wuhan and causal agents were identified as Erwinia spp. (2), Pseudomonas grimontii (1), E. chrysanthemi, and E. carotovora subsp. carovora (4). To our knowledge, this is the first report of D. dieffenbachiae causing soft rot disease on P. aphrodita in China. References: (1) X. L. Chu and B. Yang. Acta Phytopathol. Sin. 40:90, 2010. (2) Y. M. Li et al. J. Beijing Agric. Coll. 19:41, 2004. (3) M. Sławiak et al. Eur. J. Plant Pathol. 125:245, 2009. (4) Z. Y. Wu et al. J. Zhejiang For. Coll. 27:635, 2010.

First Report of a Soft Rot of Philodendron 'Con-go' in China Caused by Dickeya dieffenbachiae

Philodendron is a popular foliage plant cultivated in interiorscapes of homes, offices, and malls throughout China. A severe outbreak of a soft rot of Philodendron 'Con-go' occurred in Guangzhou, China from 2010 to 2011. The disease was characterized by leaf infections starting as pinpoint spots that are water soaked and yellow to pale brown. The lesions are sometimes surrounded by a diffuse yellow halo. When the humidity is high and temperatures are warm to hot, the spots expand rapidly, becoming slimy, irregular, and sunken with light tan centers, darker brown borders, and diffused yellow margins and may involve the entire leaf in a few days. An invasion of the midrib and larger veins by the causal bacterium often results in advancement into the petiole and stem. A survey of three areas of production of Philodendron 'Con-go' (5 ha) in Guangzhou revealed that 91% of the fields were affected at an incidence ranging from 15 to 30%. Of 41 bacterial isolates obtained from lesions, three were selected randomly for further characterization. All strains were gram negative, negative for oxidase and positive for catalase and tryptophanase (indole production), and utilized citrate, tartrate, malonate, glucose, sucrose, fructose, and maltose but not glucopyranoside, trehalose, or palatinose. Biolog analysis (version 4.20.05, Hayward, CA) identified the isolates as Pectobacterium chrysanthemi (SIM 0.804 to 0.914). According to Samson et al. (1), it was renamed as a Dickeya sp. PCR was performed on the 16S rDNA gene with primers 27f and 1495r (3) and 1,423 bp of the 16S rDNA gene (GenBank No. JN709491) showed 99% identity to P. chrysanthemi (GenBank No. AF373202), and 98% to Dickeya dieffenbachiae (GenBank No. JF311644). Additionally, the gyrB gene was amplified with primers gyrB-f1 (5'-atgtcgaattcttatgactcctc-3') and gyrB-r1 (5'-tcaratatcratattcgcygctttc-3') designed based on all the submitted gyrB gene sequences of Dickeya spp. The dnaX gene was amplified with primers dnaXf and dnaXr (2). The products were sequenced and phylogeny analyses were performed by means of MEGA 5.05. Results showed that the gyrB and the dnaX genes of the strains were 98% homologous to those of D. dieffenbachiae (GenBank Nos. JF311652 and GQ904757). Therefore, on the basis of phylogenetic trees of the 16S rDNA, gyrB, and dnaX gene sequences, the bacterial isolate named PC1 is related to D. dieffenbachiae (100% bootstrap values). Pathogenicity of each of the three strains on Philodendron 'Con-go' was confirmed by injecting 60 50-day-old seedlings each with 0.1 ml of the isolate suspension (10⁸ CFU/ml) into the leaves. Another 60 were injected with sterile water to serve as the control treatment. Plants were enclosed in plastic bags and returned to the greenhouse under 50% shade at 32°C day and 28°C night temperatures with high humidity. After 72 h, all the injected plants started to show symptoms similar to those observed on field plants, but no symptoms appeared on the control plants. The reisolates were identical to the inoculated strains in biochemical characteristics. Bacteria characteristic of the inoculated strains were not reisolated from the control plants. To our knowledge, this is the first report of D. dieffenbachiae causing soft rot of Philodendron 'Con-go' in China. References: (1) R. Samson et al. Evol. Microbiol. 55:1415, 2005. (2) M. Sławiak et al. Eur. J. Plant Pathol. 125:245, 2009. (3) W. G. Weisbury et al. J. Bacteriol. 173:697, 1991.

Diabetes mellitus and incidence and mortality of gastric cancer: a meta-analysis

AIMS

Epidemiologic studies have examined the possible associations between diabetes mellitus (DM) and gastric cancer (GC), but the results are inconclusive. We conducted a meta-analysis to assess the evidence regarding the associations between diabetes and incidences of, or mortality from, gastric cancer.

METHODS

PubMed, Embase and Web of Science were searched up to Oct 20, 2011. We identified studies that included effects estimates with 95% confidence intervals (CIs) of the associations between GC and diabetes. Summary RRs for the GC incidence and mortality were calculated using random-effects model; subgroup analyses were also performed. Heterogeneity among studies was examined using Q and I2 statistics.

RESULTS

A total of 7 case-control and 18 cohort studies met the inclusion criteria. The summary RR showed a slightly statistical link between history of DM and GC incidence (RR=1.11, 95% CI: 1.00-1.24, p=0.045, I2=79.5%). In the subgroup analyses, a positive association was noted among the studies conducted in Asia (summary RR=1.19, 95% CI: 1.07-1.32, I2=29.8%). Additionally, slight associations between DM and GC were observed by pooling the data of type 2 DM, cohort studies and the studies controlling more confounders, respectively. Furthermore, mortality from GC with diabetes was increased compared with individuals without diabetes (summary RR=1.29, 95% CI: 1.04-1.59). No publication bias was found.

CONCLUSION

Individuals with diabetes have an increased risk of developing gastric cancer, and are positively associated with gastric cancer mortality. Large better-designed cohort studies are needed to verify this conclusion.

Acute restraint stress increases intrahypothalamic oestradiol concentrations in conjunction with increased hypothalamic oestrogen receptor β and aromatase mRNA expression in female rats

Activation of the hypothalamic-pituitary-adrenal axis is considered to be one of the key physiological responses to stress and, interestingly, shows a marked sex difference. Oestradiol plays an important role in this sex difference. The present study investigated the systemic and intrahypothalamic oestradiol response to physical restraint stress in female rats. We used jugular catheterisation and intrahypothalamic microdialysis to simultaneously measure plasma oestradiol and local oestradiol concentrations in the paraventricular nucleus (PVN) of the hypothalamus. We also assessed corticotrophin-releasing hormone (CRH), aromatase, and oestrogen receptor (ER) α and β mRNA expression in the PVN by quantitative polymerase chain reaction immediately after the acute stress period. As expected, PVN CRH mRNA and plasma corticosterone were significantly increased after acute stress. Interestingly, the local oestradiol concentration in the PVN also increased during the 1-h stress period in pro-oestrus and in ovariectomised (OVX) animals. Aromatase mRNA expression in the PVN was increased markedly in pro-oestrus but only modestly in oestrus. PVN ERβ but not ERα mRNA expression was significantly elevated in pro-oestrous animals. In addition, plasma oestradiol levels increased 10 min after stress, both during pro-oestrus and oestrus but not in OVX animals. To conclude, we report an intra-hypothalamic oestradiol response to restraint stress. The rising hypothalamic oestradiol concentration together with increased ERβ gene expression indicates a positive feedback of hypothalamic oestradiol signalling during acute stress in rats.

DNA microarray: a high throughput approach for methylation detection

We described a DNA microarray-based method combined with bisulphite treatment of DNA and regular PCR to examine hyper-methylation in promoter 1A of APC gene. A set of oligonucleotide probes were designed and immobilized on the aldehyde-coated glass slides for detecting the methylation pattern of 15 selected CpG sites in the region. The methylation status of 30 colorectal tumor samples have been examined by both of methylation-specific PCR (MS-PCR) and the present microarray method. The methylation pattern of the 15 CpG sites for the samples have been obtained with the microarray. A total of 19 samples out of 30 were methylated by microarray, in which five samples cannot be detected by MS-PCR due to the methylated CpG patterns not accordant to the MS-PCR primers. The detecting ratio for methylation of APC gene of colorectal tumor samples increased from 46.7% with MS-PCR to 63.3% with the microarray, which successfully demonstrated that DNA microarray-based method not only can obtained the methylation patterns for the related genes, but also decrease the false-negative results of methylation status by the conventional MS-PCR for the investigated genes.

Alien hand syndrome: contradictive movement and disorder of color discrimination

A senile Chinese female patient with alien hand syndrome of vascular etiology is reported. This case exhibited contradictive movement, left-lateral paresis and disorder of color discrimination, which might be a new subtype of the alien limb syndrome.

[Inflammatory-inducing effect of lumbar disc tissue: an experimental study]

OBJECTIVE

To study whether herniated or degenerative lumbar disc tissues have the potentials to produce or induce peripheral blood white cells to produce inflammatory mediator phospholipase A2 (PLA2), and to find the effective inhibitors of PLA2.

METHODS

Ten specimens of lumbar discs were obtained when patients were performed operations. The peripheral blood samples were drawn out from the same ten patients (7 ml per patient). Mononuclear white cells were separated from each peripheral blood sample. Then, cell culture was performed according to the following combinations: Group 1 was mononuclearcytes; Group 2 was disc tissue; Group 3 was devitalized disc tissue + mononuclearcytes; Group 4 was devitalized disc + mononuclearcytes + dexamethasone; Group 5 was devitalized disc + mononuclearcytes + artemisinin. The activity of PLA2 was detected at last.

RESULTS

Compared with Group 3, other groups had a significant difference, (P < 0.01). Group 5 compared with Group 4 had no significant difference (P > 0.05).

CONCLUSIONS

1. Some components in disc tissue can induce mononuclearcytes to produce high activity of PLA2 which is an inflammatory mediator very possible to cause back pain and radiculopathy in lumbar disc herniation. 2. Artemisinin has similar effectiveness to dexamethasone to inhibit the production of PLA2 in vitro.

[Treatment of cervical disc herniation with percutaneous arthroscopic microdisectomy]

OBJECTIVE

To study the indications and efficacy of percutaneous cervical arthroscopic microdiscectomy (PCAD).

METHODS

Twenty eight patients with cervical discs herniation or disorders received endoscopic spine surgery, 37 intervertebral cervical discs underwent partial nuclectomy or total nucleotomy; the efficacy and complication were evaluated in three months after operation. RELUT: Good/excellent results were obtained in 23/28(82.2%) cases according to MacNab criteria; no serious complication was found; the cervical stability did not decrease in most cases.

CONCLUSION

PCAD is a safe, accuracy and rational method in diagnosing and treating herniated cervical disc and discogenic disorders.

Alterations in arginine vasopressin neurons in the suprachiasmatic nucleus in depression

BACKGROUND

Circadian rhythm disturbances are frequently found in depressed subjects. Although it has been presumed that these disturbances may reflect a disorder of the circadian pacemaker, this has never been established. The suprachiasmatic nucleus (SCN) is the pacemaker of the circadian timing system in mammals, and arginine vasopressin (AVP) is one of its major neuropeptides. As peptide content is often taken as a measure for activity, we hypothesized that a decreased number of AVP-immunoreactive (AVP-IR) neurons and amount of AVP-messenger RNA (mRNA) would be present in the SCN of depressed subjects.

METHODS

Brains of 11 subjects suffering from major depression (8 cases) and bipolar disorder (3 cases), and of 11 controls, matched for sex, age, and clock time at death, were collected. The number of AVP-IR neurons in the SCN was determined by means of a digitizer (CalComp Inc, Reading, England). The amount of AVP-mRNA expression in the SCN was quantified with the Interaktive Bild Analyse System image analysis system (Kontron, Munich, Germany).

RESULTS

In depressed subjects, the number of AVP-IR neurons in the SCN was more than one and a half times higher than in controls, while the total masked area of silver grains, as an estimate of the amount of AVP-mRNA, was about one half that of controls.

CONCLUSIONS

Contrary to our hypothesis, an increase in the number of AVP-IR neurons in the SCN in depression was found, together with an expected decrease in AVP-mRNA. These findings suggest that, in depressed patients, both the synthesis and release of AVP in the SCN is reduced, resulting in an impaired functional ability. A disbalance between AVP production and transport needs further investigation in future studies.

[Experimental study of pBMP/MPTCP in bone defects therapy]

To develop a new substitute of bone graft, which is composed of porcine bone morphogenetic protein (pBMP) and the magnetic porous tricalcium phosphate (MPTCP), we investigated the effects of pBMP/MPTCP (Group A), autologous red bone marrow/porus tricalcium phosphate (BM/PTCP) (Group B), pBMP/PTCP(Group C) on the repair of bone defects created surgically in rabbits. By gross inspection, roentgenography examination, histological examination, immunohistochemistry test of osteocalcim, quantitive histological measurement of new bone formation and biomechanical test, three kinds of substitutes were proved to be biocompatible. Group A induced more new bone formation than other two groups, and showed a better biomechanical function(P < 0.01). It is believed that pBMP/MPTCP has characteristics of strong osteoinductive capacity, good biocompatibility, excellent filling of bone defects and gradual biodegradation.

Inhibition of cellular proliferation through IkappaB kinase-independent and peroxisome proliferator-activated receptor gamma-dependent repression of cyclin D1

The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-regulated nuclear receptor superfamily member. Liganded PPARgamma exerts diverse biological effects, promoting adipocyte differentiation, inhibiting tumor cellular proliferation, and regulating monocyte/macrophage and anti-inflammatory activities in vitro. In vivo studies with PPARgamma ligands showed enhancement of tumor growth, raising the possibility that reduced immune function and tumor surveillance may outweigh the direct inhibitory effects of PPARgamma ligands on cellular proliferation. Recent findings that PPARgamma ligands convey PPARgamma-independent activities through IkappaB kinase (IKK) raises important questions about the specific mechanisms through which PPARgamma ligands inhibit cellular proliferation. We investigated the mechanisms regulating the antiproliferative effect of PPARgamma. Herein PPARgamma, liganded by either natural (15d-PGJ(2) and PGD(2)) or synthetic ligands (BRL49653 and troglitazone), selectively inhibited expression of the cyclin D1 gene. The inhibition of S-phase entry and activity of the cyclin D1-dependent serine-threonine kinase (Cdk) by 15d-PGJ(2) was not observed in PPARgamma-deficient cells. Cyclin D1 overexpression reversed the S-phase inhibition by 15d-PGJ(2). Cyclin D1 repression was independent of IKK, as prostaglandins (PGs) which bound PPARgamma but lacked the IKK interactive cyclopentone ring carbonyl group repressed cyclin D1. Cyclin D1 repression by PPARgamma involved competition for limiting abundance of p300, directed through a c-Fos binding site of the cyclin D1 promoter. 15d-PGJ(2) enhanced recruitment of p300 to PPARgamma but reduced binding to c-Fos. The identification of distinct pathways through which eicosanoids regulate anti-inflammatory and antiproliferative effects may improve the utility of COX2 inhibitors.

A phospholipase C inhibitor, phenylmethylsulfonyl fluoride, ameliorates ischemic injury to brain mitochondria in rats

AIM

To study the effect of phenylmethylsulfonyl fluoride (PMSF), a phospholipase C inhibitor, on ischemic injury to brain mitochondria in rats.

METHODS

The phospholipid level, membrane fluidity, and respiratory control ratio of brain mitochondria were measured. The effect of phenylmethylsulfonyl fluoride was tested.

RESULTS

The phospholipid level, membrane fluidity, and respiratory control ratio of brain mitochondria in ischemia group decreased but increased in the PMSF treatment group (P < 0.05).

CONCLUSION

PMSF ameliorated ischemic injury to brain mitochondria in rats.

ERK signalling in metastatic human MDA-MB-231 breast carcinoma cells is adapted to obtain high urokinase expression and rapid cell proliferation

Increased urokinase plasminogen activator (u-PA) production is associated with tumor invasion and metastasis in several malignancies, including breast cancer. The mechanisms underlying constitutive u-PA expression are not well understood. We examined the relationship between the signal strength of the ERK pathway and the level of u-PA expression in the metastatic human breast cancer cell line MDA-MB-231. Treatment with the MEK1 inhibitor PD98059 resulted in decreased ERK1/2 phosphorylation and decreased u-PA mRNA and protein expression. Inhibition of ERK1/2 activity also led to decreased cell proliferation and to decreased cyclin D1 expression. Less than 5% of total ERK1/2 was phosphorylated in exponentially growing MDA-MB-231 cells, and ERK1/2 activity could be stimulated by okadaic acid. Okadaic acid did not stimulate u-PA expression, but induced strong expression of the cdk-inhibitor p21Cip1. These findings suggest that ERK1/2 signaling is tuned to a level which results in high u-PA expression and rapid cell proliferation.

Male-to-female transsexuals have female neuron numbers in a limbic nucleus

Transsexuals experience themselves as being of the opposite sex, despite having the biological characteristics of one sex. A crucial question resulting from a previous brain study in male-to-female transsexuals was whether the reported difference according to gender identity in the central part of the bed nucleus of the stria terminalis (BSTc) was based on a neuronal difference in the BSTc itself or just a reflection of a difference in vasoactive intestinal polypeptide innervation from the amygdala, which was used as a marker. Therefore, we determined in 42 subjects the number of somatostatin-expressing neurons in the BSTc in relation to sex, sexual orientation, gender identity, and past or present hormonal status. Regardless of sexual orientation, men had almost twice as many somatostatin neurons as women (P < 0.006). The number of neurons in the BSTc of male-to-female transsexuals was similar to that of the females (P = 0.83). In contrast, the neuron number of a female-to-male transsexual was found to be in the male range. Hormone treatment or sex hormone level variations in adulthood did not seem to have influenced BSTc neuron numbers. The present findings of somatostatin neuronal sex differences in the BSTc and its sex reversal in the transsexual brain clearly support the paradigm that in transsexuals sexual differentiation of the brain and genitals may go into opposite directions and point to a neurobiological basis of gender identity disorder.

[Myelopathy-hand and cervical spondylotic myelopathy]

The clinical manifestations and MRI characteristics of 58 patients with cervical spondylotic myelopathy were analysed in this study. The results showed that there was myelopathy-hand in 49 patients and none in 9 patients. Two groups were not significantly different in gender, age, course and involved segment, side or level of spinal cord(P > 0.05), but were significantly different in the compression degree of spinal cord(P < 0.01). In the positive group, the degree of myelopathy-hand was positively related to the severity of spastic gait, pyramidal tract sign and spinal cord compression.

Decreased vasopressin gene expression in the biological clock of Alzheimer disease patients with and without depression

Circadian rhythm disturbances are frequently present in Alzheimer disease (AD). In the present study, we investigated the expression of vasopressin (AVP) mRNA in the human suprachiasmatic nucleus (SCN). The in situ hybridization procedure on formalin-fixed paraffin-embedded material was improved to such a degree that we could, for the first time, visualize AVP mRNA expressing neurons in the human SCN and carry out quantitative measurements. The total amount of AVP mRNA expressed as masked silver grains in the SCN was 3 times lower in AD patients (n = 14; 2,135 +/- 597 microm2) than in age- and time-of-death-matched controls (n = 11; 6,667 +/- 1466 microm2) (p = 0.003). No significant difference was found in the amount of AVP mRNA between AD patients with depression (n = 7) and without depression (n = 7) (2,985 +/-1103 microm2 and 1,285 +/- 298 microm2, respectively; p = 0.38). In addition, the human SCN AVP mRNA expressing neurons showed a marked day-night difference in controls under 80 years of age. The amount of AVP mRNA was more than 3 times higher during the daytime (9,028 +/- 1709 microm2, n = 7) than at night (2,536 +/- 740 microm2, n = 4; p = 0.02), whereas no clear diurnal rhythm of AVP mRNA in the SCN was observed in AD patients. There was no relationship between the amount of AVP mRNA in the SCN and age at onset of dementia, duration of AD and the neuropathological changes in the cerebral cortex. These findings suggest that the neurobiological basis of the circadian rhythm disturbances that are responsible for behavioral rhythm disorders is located in the SCN. It also explains the beneficial effects of light therapy on nightly restlessness in AD patients.

Induction of experimental autoimmune neuritis in CD4-8-C57BL/6J mice

The C57BL/6J mice strain is known to be reputedly resistant to induction of experimental autoimmune neuritis (EAN), an animal model of Guillain-Barré syndrome in humans. Here we describe the induction of EAN in mice of the C57BL/6J background by transfer into naive syngeneic recipients bovine peripheral nerve myelin (BPM)-primed donor lymph node cells that had been stimulated in vitro with the bovine peripheral nervous system (PNS) myelin P2 protein peptide 57-81 followed by challenge with BPM, Freund's complete adjuvant and pertussis toxin. EAN was more severe, both clinically and histologically, and accompanied by extensive infiltration of inflammatory cells and demyelination in peripheral nerves when examined on day 30 after transfer of primed T cells from CD4- 8- mice into identical naive hosts than after transfer of cells from primed wild type, CD4-/- or CD8-/- mice to corresponding recipient animals. EAN in CD4-8- mice was also associated with elevated numbers of P2 peptide-reactive interferon-y (TFN-gamma) secreting cells and alphabeta T cells were present in lymph nodes and spleens. The data suggest that PNS myelin activated T cells from an EAN-resistant mice strain are capable of homing to the PNS. The expanded CD4-8- alphabeta T cells may have helper and effector functions, related to initiation of EAN in the CD4-8- mice. Lack of CD4+ and CD8+ expressing cells does not prevent the initiation of an autoimmune disease.

Activation and degeneration during aging: a morphometric study of the human hypothalamus

During the course of aging both activation and degenerative changes are found in the human hypothalamus. Degeneration may start around middle-age in some neurotransmitter- or neuromodulator-containing neurons. For instance, a decreased number of vasoactive intestinal polypeptide (VIP) neurons was observed in the suprachiasmatic nucleus (SCN) of middle-aged males. The normal circadian fluctuations seen in the number of vasopressin (AVP) neurons in the SCN of young subjects diminished in subjects older than 50 years. Moreover, a sharp decline in cell number was found in the sexually dimorphic nucleus (SDN) after 50 years in males. On the other hand, many hypothalamic systems remain perfectly intact during aging like the oxytocin (OXT) neurons in the paraventricular nucleus (PVN). The AVP neurons in the PVN are activated during aging as appears from their increasing cell number. Also the corticotrophin-releasing hormone (CRH) neurons of the PVN are activated in the course of aging, as indicated by their increased number and their increased AVP coexpression. Part of the infundibular nucleus, the subventricular nucleus, contains hypertrophic neurokinin B neurons in postmenopausal women. It can be concluded that a multitude of changes in the various hypothalamic nuclei may be the biological basis for many functional changes in aging, i.e., both endocrine and central alterations, and that only a minority of the possible human hypothalamic changes have so far been studied.

Decreased melatonin levels in postmortem cerebrospinal fluid in relation to aging, Alzheimer's disease, and apolipoprotein E-epsilon4/4 genotype

Sleep disruption, nightly restlessness, sundowning, and other circadian disturbances are frequently seen in Alzheimer's disease (AD) patients. Changes in the suprachiasmatic nucleus and pineal gland are thought to be the biological basis for these behavioral disturbances. Melatonin is the main endocrine message for circadian rhythmicity from the pineal. To determine whether melatonin production was affected in AD, melatonin levels were determined in the cerebrospinal fluid (CSF) of 85 patients with AD (mean age, 75 +/- 1.1 yr) and in 82 age-matched controls (mean age, 76 +/- 1.4 yr). Ventricular postmortem CSF was collected from clinically and neuropathologically well defined AD patients and from control subjects without primary neurological or psychiatric disease. In old control subjects (>80 yr of age), CSF melatonin levels were half of those in control subjects of 41-80 yr of age [176 +/- 58 (n = 29) and 330 +/- 66 (n = 53) pg/mL, respectively; P = 0.016]. We did not find a diurnal rhythm in CSF melatonin levels in control subjects. In AD patients the CSF melatonin levels were only one fifth (55 +/- 7 pg/mL) of those in control subjects (273 +/- 47 pg/mL; P = 0.0001). There was no difference in the CSF melatonin levels between the presenile (42 +/- 11 pg/mL; n = 21) and the senile (59 +/- 8 pg/mL; n = 64; P = 0.35) AD patients. The melatonin level in AD patients expressing apolipoprotein E-epsilon3/4 (71 +/- 11 pg/mL) was significantly higher than that in patients expressing apolipoprotein E-epsilon4/4 (32 +/- 8 pg/ml; P = 0.02). In the AD patients no significant correlation was observed between age of onset or duration of AD and CSF melatonin levels. In the present study, a dramatic decrease in the CSF melatonin levels was found in old control subjects and even more so in AD patients. Whether supplementation of melatonin may indeed improve behavioral disturbances in AD patients should be investigated.

Analysis of mechanisms and frequency of CDKN2A/B gene loss during progression of RAS-transformed rat embryo fibroblast clones

Rat embryo fibroblasts (REFs) are inefficiently transformed by RAS-oncogenes. Induction of p16INK4A expression by RAS has been suggested to contribute to this resistance. Glucocorticoid hormones, (DEX), enhance REF transformation by RAS and facilitates the isolation of transformed and immortal cell lines. We show that DEX induced cell proliferation is paralleled by a decrease in Cdkn2a gene transcripts, suggesting a mechanism for hormone promotion. The mechanisms of progression into hormone independent cell lines were examined. Twenty-two of 30 clones which reached a population size of approximately 10(6) cells could be established as cell lines. All lines studied showed homozygous deletions of the Cdkn2 loci (Cdkn2a and Cdkn2b) on RNO5. LOH was found for all RNO5 genetic markers examined in 7 of 19 cell lines, suggesting non-disjunction events. In the remaining 12 cell lines, both copies of Cdkn2 appeared to be lost by deletions/rearrangements, some of which could by demonstrated by karyotype analysis. We conclude that (i) clonal expansion of RAS-transfected REF by DEX is paralleled by down-regulation of Cdkn2a expression; (ii) homozygous deletion of Cdkn2 were estimated to occur at a frequency of 2 x 10(-8)/cell/generation or higher, and (iii) deletion/rearrangements and nondisjunction appear to be the main mechanisms leading to deletion of Cdkn2.

[Localization of the gene for 4 hereditary multiple exostoses families]

We investigated 11 families with hereditary multiple exostoses (EXT) by linkage analysis using 8 short-tandem-repeat (CA)n polymorphic markers on chromosomes 8, 11 and 19. The Lod score in four families indicated that the gene responsible for EXT is located in the pericentromeric region of chromosome 11.

Rapid isolation of phage displayed antibodies to beta-actin eluted from two-dimensional electrophoresis gel

We describe a simple and efficient procedure which can be used to prepare antibodies to proteins extracted by two-dimensional gel electrophoresis (2-DE), using beta-actin as a model. Protein was electroeluted from a stained gel, biotinylated and used for selection of phage from a semisynthetic phage antibody library. After four rounds of selection using 50 ng beta-actin per cycle, approximately 8 X 10(3) phage were recovered. Antibody fragments were prepared from 21 randomly picked clones. Six of eighteen (6/18) antibody-positive clones produced antibody fragments reacting against beta-actin in an enzyme linked immunosorbent assay (ELISA). Sequencing of the HC-CDR3-region showed that all six clones were independent isolates, suggesting that a large number of independent phage antibody reactivities were generated.

Activation of tissue-factor gene expression in breast carcinoma cells by stimulation of the RAF-ERK signaling pathway

Tissue factor (TF) is a cell-surface glycoprotein responsible for initiating the extrinsic pathway of coagulation. The overexpression of TF in human malignancy has been correlated with the angiogenic phenotype, poor prognosis, and thromboembolic complications. The mechanisms underlying constitutive expression of TF in cancer cells are poorly defined. We cloned TF cDNA on the basis of its strong expression in metastatic MDA-MB-231 breast carcinoma cells in contrast to its weak expression in non-metastatic MCF-7 cells. Transient transfection analysis showed that TF promoter activity in MCF-7 cells could be stimulated by expression of a membrane-targeted raf kinase (raf-CAAX). raf-induced activity was dependent on the presence of an AP-1/NF-kappaB motif in the TF promoter and was inhibited by dominant-negative mutants of jun and by I-kappaB alpha. MDA-MB-231 cells were found to contain higher levels of ERK1/2 kinase activity than did MCF-7 cells. Electrophoretic mobility shift assays showed that MDA-MB-231 nuclear proteins bound strongly to an oligonucleotide corresponding to the AP-1/NF-kappaB sequence, whereas MCF-7 nuclear extracts showed weak binding to this element. Finally, we showed that TF mRNA levels in MDA-MB-231 cells declined after addition of the mitogen-activated protein kinase kinase inhibitor PD98059. Our data showed that activation of the raf-ERK pathway led to activation of TF expression in breast carcinoma cells and suggested that constitutive activation of this pathway leads to high TF expression in MDA-MB-231 cells.

Codeletion of the JUN proto-oncogene and the CDKN2A tumor-suppressor gene in HRAS-transformed rat embryo fibroblast cell lines

The cyclin kinase inhibitor p16, encoded by the CDKN2A gene, suppresses the transformation of mouse embryonic fibroblasts by oncogenic RAS. In contrast, the c-JUN transcription factor (a major component of AP-1) has been suggested to be required for RAS transformation of rodent fibroblasts. The CDKN2A gene and the JUN proto-oncogene have both been mapped to rat chromosome band 5q31-33. We here show that both copies of the CDKN2A gene are deleted in four of eight transformed cell lines derived from the transfection of rat embryo fibroblasts (REF) with HRASVAL12. In two cell lines, the homozygous deletions involved a larger area on 5q31-33, which included the JUN proto-oncogene. JUN-defective cells showed high AP-1 binding activity. Both AP-1 binding activity and stromelysin (transin) mRNA expression were found to be RAS-dependent in one of the JUN-defective cell lines. The finding of deletions of the CDKN2A gene in RAS-transformed REF cell lines is consistent with the concept that CDKN2A suppresses transformation by RAS. The occasional concomitant loss of the adjacent JUN proto-oncogene does not prevent establishment of transformed and tumorigenic cell lines.

The Ras farnesylation inhibitor BZA-5B increases the resistance to cisplatin in a human melanoma cell line

Ras proteins have been implicated in transducing cellular responses to DNA damaging agents. We used BZA-5B, an inhibitor of Ras-farnesylation, to examine the role of Ras in cellular sensitivity to cisplatin. A human melanoma cell line (224) with a Gln61Arg mutation in N-ras was used for these studies. We report that BZA-5B treated cells show an increased resistance to cisplatin. BZA-5B treatment decreased the number of cells showing in situ DNA fragmentation and increased cell viability and clonogenic survival after cisplatin treatment. Further experiments showed that cisplatin induction of the immediate early genes c-jun and p21cip1 was not affected by BZA-5B. Finally, we show that cisplatin causes only weak activation of Jun N-terminal kinase (JNK) in a human melanoma cell line. We conclude that inhibition of Ras function decreases the sensitivity of human melanoma cells to cisplatin-induced cell death.

Morphometric analysis of vasopressin and vasoactive intestinal polypeptide neurons in the human suprachiasmatic nucleus: influence of microwave treatment

The vasopressin (VP) and vasoactive intestinal polypeptide (VIP)-expressing neurons in the human suprachiasmatic nucleus (SCN) were morphometrically determined with or without microwave (MW) treatment. Both an enlarged volume and an increased number of neurons were found in the VP and VIP subnucleus of the SCN following MW treatment. The staining of VIP neurons by MW treatment improved much more than that of the VP neurons. Without MW treatment the VP- and VIP-expressing neurons were localized mainly in the central part of the subnuclei, whereas by increasing the sensitivity of the staining by MW treatment more neurons became visible, particularly in the peripheral areas of the subnuclei.

Expression of CDK inhibitor genes in immortalized and carcinoma derived breast cell lines

The expression of the CDK inhibitor (CDI) genes p15(INK4B), p16(INK4A), p18 and p21Cip1 was examined in immortalized, non-tumorigenic cell lines derived from human breast epithelium, and in breast carcinoma derived lines. An increase in p16 expression, suggesting loss of pRb function, was recorded in two immortalized lines, and complete absence of p16 mRNA was observed in the third. In contrast, high levels of p21Cip1 mRNA were found in two immortalized lines. In addition to differences in p16 and p21Cipl, variations in the expression of p15 and p18 mRNA were observed between different cell lines. Immortalized A1N4 and HBL100 cells, as well as ER+, MCF-7 carcinoma cells, expressed high levels of p15 mRNA. A1N4, HBL100 cells and highly malignant ER MDA-MB-231 cells expressed high levels of p18 mRNA. Inhibition by genistein indicated that p18 mRNA expression was dependent on cellular tyrosine kinases in these cells. We conclude that the pattern of p15 and p18 mRNA expression was distinct from that of p16 and p21Cip1, suggesting different modes of regulation.