Decrease of the insulin-like growth factor-1 bioavailability in spontaneously hypertensive rats with erectile dysfunction

We investigated the role of insulin-like growth factor-1 (IGF-1) in spontaneously hypertensive rats with erectile dysfunction. Firstly, we evaluated intracavernous pressure. The bioavailability of IGF-1 at both mRNA and protein levels were measured by quantitative real-time PCR and Western blot respectively. Then, cavernous cyclic guanosine monophosphate concentrations were detected by enzyme-linked immunosorbent assay. The cavernosal pressure was significantly decreased in the hypertensive and the propranolol treatment groups compared to the normal control group (P < 0.01). Cavernous IGF-1 bioavailability and the concentrations of cavernous cyclic guanosine monophosphate were both significantly decreased in the hypertensive and the propranolol treatment groups compared to the normal control group (P < 0.01). This study suggests that an obvious decrease in cavernous IGF-1 levels might play an important role in spontaneously hypertensive rats with erectile dysfunction.

Spontaneous renal hemorrhage caused by invasive mole: a case report

CASE

The authors report a case with spontaneous renal hemorrhage caused by invasive mole. The diagnosis was gestational trophoblastic disease (GTD), with metastasis to brain, kidneys, and lungs at Stage IV. The patient was given etoposide-methotrexate-actinomycin D plus cyclophosphamide-vincristine (EMACO) treatment regimen for 11 times including three times with consolidation chemotherapies. Laparoscopically-assisted vaginal hysterectomy (LAVH) + laparoscopic-assisted left renal excision + evacuation of the left perirenal hematoma were performed during the eighth chemotherapy.

CONCLUSION

Post-operational pathological examination revealed trophoblasts within the lesions present in uterine fundus and the residue images of a few trophoblasts present in the left renal mass.

Microbubble generation by piezotransducer for biological studies

Bubbles induced by blast waves or shocks are speculated to be the major cause of damages in biological cells in mild traumatic brain injuries. Microbubble collapse was found to induce noticeable cell detachment from the cell substrate, changes in focal adhesion and biomechanics. To better understand the bubble mechanism, we would like to construct a system, which allows us to clearly differentiate the impact of bubbles from that of shocks. Such a generator needs to be low profile in order to place under a microscope. A piezoelectric transducer system was designed to meet the need. The system uses either a flat or a spherical focusing piezoelectric transducer to produce microbubbles in a cuvette loaded with cell-culture medium. The transducer is placed on the side of the cuvette with its axis lining horizontally. A cover slip is placed on the top of the cuvette. The impact of the waves to the cells is minimized as the cover slip is parallel to the direction of the wave. Only bubbles from the medium reach the cover slip and interact with cells. The effect of bubbles therefore can be separated that of pressure waves. The bubbles collected on a cover slip range in size from 100 μm to 10 μm in radius, but the dominant size is 20-30 μm.

Metal-insulator transition in the quasi-one-dimensional transport of fractional quantum Hall states

We investigate edge state transmission in quantum point contacts (QPCs) in the fractional quantum-Hall regime, finding behavior reminiscent of a metal-insulator transition. The transition is suggested by an unusual behavior of the differential conductance in the fractional-quantum-Hall regime, and by the presence of a fixed point and universal scaling in the temperature dependence of the linear conductance. Noting that the 0.7 feature evolves continuously into a last fractional plateau at high magnetic fields, we suggest that this still unresolved feature may itself be viewed as a manifestation of a local, microscopic, metal-insulator transition.

The effects of cardiopulmonary bypass on pulmonary function during robotic cardiac surgery

BACKGROUND

We aimed to investigate the effects of cardiopulmonary bypass (CPB) on pulmonary function under the conditions of one-lung ventilation (OLV) and carbon dioxide pneumothorax in robotic cardiac surgery.

METHODS

Ninety-eight patients underwent robotic cardiac surgery using the da Vinci Surgical System, including 58 on-pump surgeries and 40 off-pump surgeries. Respiratory parameters and arterial blood gases were assessed at the following time points: 25 min after the induction of anesthesia under two-lung ventilation (T1), 25 min after OLV (T2), 25 min after the termination of CPB under OLV in the on-pump group or 25 min after the main surgery intervention in the off-pump group (T3) and 20 min before the end of surgery (T4). Dynamic lung compliance (Cdyn), alveolar-arterial PO2 difference (PA-aDO2), oxygenation index (OI) and artery-alveolar O2 pressure ratio (a/A) were calculated.

RESULTS

No significant differences in pulmonary function parameters between T2 and T3 were observed in the off-pump group. However, in the on-pump group, compared with those at T2, PETCO2, Ppeak, PaCO2 and PA-aDO2 at T3 were higher, whereas SpO2, Cdyn, PaO2, OI and a/A were lower (p<0.05). Comparisons between the two groups at T3 indicated that SpO2, Cdyn, PaO2, OI and a/A were higher, while Ppeak, PaCO2 and PA-aDO2 were lower in the off-pump group (p<0.01).

CONCLUSIONS

In robotic cardiac surgery under the conditions of OLV and carbon dioxide pneumothorax, CPB worsened pulmonary function and tolerance to OLV and carbon dioxide pneumothorax.

First Report of Meloidogyne graminicola Infecting Banana in China

Bananas (Musa spp.) are one of world's most popular fruits, and China is the third largest banana-producing country in the world. Root-knot nematodes, Meloidogyne spp., are common pests of banana worldwide, but damage to this crop caused by M. graminicola has not been reported up to now. During a survey of root-knot nematode species infecting banana in Fujian Province, China, swollen, galled primary and secondary root samples of Musa nana cv. Tianbao (AAA) were collected from two commercial fields in Nanjing County in May 2013. The affected plants did not exhibit obvious above-ground symptoms. Seriously infected roots were malformed and dehiscent, with the tissue discolored and rotting. Examination of symptomatic roots revealed one to several females of Meloidogyne sp. within each gall, with egg masses that were often completely embedded within the gall without protruding through the root surface, and with second-stage juveniles (J2) hatched inside the galls. Population densities of this nematode ranged from 452 to 2,056 eggs and J2 per 5 g of fresh roots. Males were rarely observed. Morphological measurements of 25 females and 20 J2 matched the original description of M. graminicola (1). The perineal patterns of females were dorsoventrally ovoid, with low to moderately high and round dorsal arches and lacking obvious lateral lines; striae were smooth and some were broken by a few obvious irregular, zig-zag striae in the dorsal part of the pattern; phasmids were close together (13.1 to 19.7 μm). The J2 had long tapered tails (63.4 to 75.5 μm), with long narrow hyalines (13.1 to 19.9 μm) and marked clavate termini. DNA was extracted from one mature female. The ITS1-5.8S-ITS2 rDNA region was amplified with V5367/26S (TTGATTACGTCCCTGCCCTTT/TTTCACTCGCCGTTACTAAGG) (2) and the COII and IRNA mtDNA genes were amplified with C2F3/MRH106 (GGTCAATG TTCAGAAATTTGTGG/AATTTCTAAAGACTTTTCTTAGT) (3) and then sequenced. The sequences were subjected to a database search using BLAST to verify the identity. Sequences from the ITS region were 788 bp (GenBank Accession Nos. KM111531 and KM236560) and were 96.8 to 99.1% identical to the known sequences of M. graminicola in Genbank. Sequences from the mtDNA were 666 bp (KM111533 and KM236559) and showed 99.1 to 99.4% homology with the known sequences of M. graminicola (KJ139963 and HG529223). In glasshouse tests, banana plantlets (M. nana cv. Tianbao) about 20 cm high were transplanted in 25-cm-diameter pots and inoculated with 5,000 J2 of each collected population of M. graminicola replicated six times; a noninoculated control was included. After 15 weeks, all inoculated plants were stunted and chlorotic. Galling symptoms on roots were similar to those in the field, and dissection of galled root tissue revealed that different life stages of the nematode were present, with population densities ranging from 1,238 to 6,562 eggs and J2 per 5 g of fresh roots. The noninoculated control plants grew well and had no galling symptoms on the roots. These results confirmed the nematodes' pathogenicity on banana. On the basis of these results, the root-knot nematodes isolated from banana in Nanjing County were confirmed as M. graminicola. To our knowledge, this is the first report of a natural infection of banana with M. graminicola. References: (1) A.M. Golden and W. Birchfield. Plant Dis. Rep. 52:423, 1968. (2) T. C. Vrain et al. Fund. Appl. Nematol. 15:565, 1992. (3) J. Xu et al. Eur. J. Plant Pathol. 110:309, 2004.

Wnt5a is involved in the pathogenesis of cutaneous lichen planus

BACKGROUND

Cutaneous lichen planus (CLP) is a chronic inflammatory and immune-mediated disease. Wnt5a is one of the most extensively studied Wnt proteins, and has important functions in stimulating inflammation, cell proliferation, cell fate determination and cell differentiation. Wnt5a expression in CLP has not been comprehensively studied to date.

AIM

To determine the expression and distribution of Wnt5a in CLP.

METHODS

Skin samples were obtained from patients with CLP and healthy controls (HCs). The WNT5A gene was detected by real-time quantitative PCR, and Wnt5a protein by immunohistochemical analysis and western blotting.

RESULTS

WNT5A mRNA was upregulated in CLP samples compared with the HC skin samples (P < 0.001). Wnt5a protein was overexpressed in all layers of the epidermis and dermis in CLP lesions compared with HC skin (all P < 0.001). These results were confirmed by western blotting.

CONCLUSIONS

The data presented in this study suggest that Wnt5a pathway may play an important role in the pathogenesis of CLP.

First Report of Meloidogyne enterolobii on Carrot in China

Carrot (Daucus carota var. sativus) is one of the 10 most economically important vegetable crops in the world. Recently, stunted and yellowing carrots grown on sandy soil in several commercial fields were observed in Dongshan County, Fujian Province, China. Many round to irregular shaped lumps and swellings were present on the surface of tap and fibrous roots, often with secondary roots emerging from the galls on taproots. Severe infection caused short, stubby, forked taproots leading to losses in quality and marketability. Meloidogyne sp. females and egg masses were dissected from the galls. The perineal patterns from 20 females were oval shaped with moderate to high dorsal arches and mostly lacking obvious lateral lines. The second-stage juvenile mean body length (n = 20) was 416 (390 to 461) μm; lateral lips were large and triangular in face view; tail was thin and length was averaged 56.1 (49.8 to 62.1) μm, with a broad, bluntly rounded tip. These morphological characteristics matched the original description of M. enterolobii (5). Species identity was further explored by sequencing the mitochondrial DNA (mtDNA) region between COII and the lRNA genes using primers C2F3/MRH106 (GGTCAATGTTCAGAAATTTGTGG/AATTTCTAAAGACTTTTCTTA GT) (4). A DNA fragment of ~840 bp was obtained and the sequence (GenBank Accession No. KJ146864) was compared with those in GenBank using BLAST and was 100% identical to the sequences of M. enterolobii and M. mayaguensis, a synonym of M. enterolobii (4). Part of the rDNA spanning ITS1, 5.8S gene, ITS2 was amplified with primers V5367/26S (TTGATTACGTCCCTGCCCTTT/TTTCACTCGCCGTTACTAAGG) (3), and the sequence obtained (KJ146863) was 99 to 100% identical to sequences of M. enterolobii (KF418369.1, KF418370.1, JX024149.1, and JQ082448.1). For further confirmation, M. enterolobii specific primers Me-F/Me-R (AACTTTTGTGAAAGTGCCGCTG/TCAGTTCAGGCAGGATCAACC) (2) were used for amplification of the rDNA-IGS2 sequences of eight populations of the nematode from three localities. A 200-bp amplification product was produced by each population, whereas no product was amplified from control populations of M. incognita or M. javanica. A single product of ~320 bp was obtained using primers 63VNL/63VTH (GAAATTGCTTTATTGTTACTAAG/TAGCCACAGCAAAATAGTTTTC ) (1) from the mtDNA 63-bp repeat region for these populations, and the sequence (KJ146861) showed 100% identity with sequences of M. enterolobii (AJ421395.1, JF309159.1, and JF309160.1). Therefore, the population of Meloidogyne sp. on carrot was confirmed to be M. enterolobii. This nematode has been reported to infect more than 20 plant species belonging to seven families, including Annonaceae, Cucurbitaceae, Convolvulaceae, Fabaceae, Marantaceae, Myrtaceae, and Solanaceae in China. To our knowledge, this is the first report of infection of carrot by M. enterolobii and the first record of M. enterolobii parasitizing a plant in the family Apiaceae in China. M. enterolobii has been reported in Guangdong and Hainan provinces, China. This is the first report of M. enterolobii in Fujian Province, in southeast China. References: (1) V. C. Blok et al. Nematology 4:773, 2002. (2) H. Long et al. Acta Phytopathol. Sin. 36:109, 2006. (3) T. C. Vrain et al. Fundam. Appl. Nematol. 15:565, 1992. (4) J. Xu et al. Eur. J. Plant Pathol. 110:309, 2004. (5) B. Yang and J. D. Eisenback. J. Nematol. 15:381, 1983.

On the zero-bias anomaly and Kondo physics in quantum point contacts near pinch-off

We investigate the linear and non-linear conductance of quantum point contacts (QPCs), in the region near pinch-off where Kondo physics has previously been connected to the appearance of the 0.7 feature. In studies of seven different QPCs, fabricated in the same high-mobility GaAs/AlGaAs heterojunction, the linear conductance is widely found to show the presence of the 0.7 feature. The differential conductance, on the other hand, does not generally exhibit the zero-bias anomaly (ZBA) that has been proposed to indicate the Kondo effect. Indeed, even in the small subset of QPCs found to exhibit such an anomaly, the linear conductance does not always follow the universal temperature-dependent scaling behavior expected for the Kondo effect. Taken collectively, our observations demonstrate that, unlike the 0.7 feature, the ZBA is not a generic feature of low-temperature QPC conduction. We furthermore conclude that the mere observation of the ZBA alone is insufficient evidence for concluding that Kondo physics is active. While we do not rule out the possibility that the Kondo effect may occur in QPCs, our results appear to indicate that its observation requires a very strict set of conditions to be satisfied. This should be contrasted with the case of the 0.7 feature, which has been apparent since the earliest experimental investigations of QPC transport.

Tuning the Fano resonance with an intruder continuum

Through a combination of experiment and theory we establish the possibility of achieving strong tuning of Fano resonances (FRs), by allowing their usual two-path geometry to interfere with an additional, "intruder", continuum. As the coupling strength to this intruder is varied, we predict strong modulations of the resonance line shape that, in principle at least, may exceed the amplitude of the original FR itself. For a proof-of-concept demonstration of this phenomenon, we construct a nanoscale interferometer from nonlocally coupled quantum point contacts and utilize the unique features of their density of states to realize the intruder. External control of the intruder coupling is enabled by means of an applied magnetic field, in the presence of which we demonstrate the predicted distortions of the FR. This general scheme for resonant control should be broadly applicable to a variety of wave-based systems, opening up the possibility of new applications in areas such as chemical and biological sensing and secure communications.

Formation of a protected sub-band for conduction in quantum point contacts under extreme biasing

Managing energy dissipation is critical to the scaling of current microelectronics and to the development of novel devices that use quantum coherence to achieve enhanced functionality. To this end, strategies are needed to tailor the electron-phonon interaction, which is the dominant mechanism for cooling non-equilibrium ('hot') carriers. In experiments aimed at controlling the quantum state, this interaction causes decoherence that fundamentally disrupts device operation. Here, we show a contrasting behaviour, in which strong electron-phonon scattering can instead be used to generate a robust mode for electrical conduction in GaAs quantum point contacts, driven into extreme non-equilibrium by nanosecond voltage pulses. When the amplitude of these pulses is much larger than all other relevant energy scales, strong electron-phonon scattering induces an attraction between electrons in the quantum-point-contact channel, which leads to the spontaneous formation of a narrow current filament and to a renormalization of the electronic states responsible for transport. The lowest of these states coalesce to form a sub-band separated from all others by an energy gap larger than the source voltage. Evidence for this renormalization is provided by a suppression of heating-related signatures in the transient conductance, which becomes pinned near 2e(2)/h (e, electron charge; h, Planck constant) for a broad range of source and gate voltages. This collective non-equilibrium mode is observed over a wide range of temperature (4.2-300 K) and may provide an effective means to manage electron-phonon scattering in nanoscale devices.

Predictors for dose reduction of antiviral therapy in older patients infected with hepatitis C virus: a meta-regression analysis

Treatment-related adverse events (AE) were more frequent in older patients treated by pegylated interferon (PEG-IFN) plus ribavirin (RBV) for chronic hepatitis C (CHC), and most of them required dose reduction. A meta-regression analysis was conducted to explore the possible reasons for this occurrence. We searched MEDLINE, EMBASE, and Web of Science through May 2013, for clinical trials examining the safety of PEG-IFN plus RBV in elderly patients with CHC. Data were extracted for host, viral, and outcome information. Single-arm meta-analysis was performed to evaluate AE. Meta-regression analysis was conducted to explore predictors for dose reduction secondary to AE. Eighteen observational studies met the inclusion criteria. The overall incidences of AE were 61.3%. Dose reductions due to AE were 54.2%. In patients with genotype 1, the rate of sustained virological response (SVR) was 36.9%. In patients with genotypes 2 or 3, the rate of SVR was 72.8%. Patients with more dose reduction due to AE have a tendency toward a lower likelihood of obtaining SVR (coefficient:-0.529), especially for genotype 1 patients. Host factors (male gender, coefficient 4.403; higher body weight, coefficient 0.140; and advanced fibrosis stage, coefficient 1.582) and viral factors (HCV genotype 1, coefficient 2.279) have a significant impact on dose reduction due to AE. Some host and viral factors affected dose reduction due to AE. Increasing rates of fibrosis with age may play a role as a mechanism affecting dose reduction secondary to AE and SVR in different age groups.

The nature and origin of nucleus-like intracellular inclusions in Paleoproterozoic eukaryote microfossils

The well-known debate on the nature and origin of intracellular inclusions (ICIs) in silicified microfossils from the early Neoproterozoic Bitter Springs Formation has recently been revived by reports of possible fossilized nuclei in phosphatized animal embryo-like fossils from the Ediacaran Doushantuo Formation of South China. The revisitation of this discussion prompted a critical and comprehensive investigation of ICIs in some of the oldest indisputable eukaryote microfossils-the ornamented acritarchs Dictyosphaera delicata and Shuiyousphaeridium macroreticulatum from the Paleoproterozoic Ruyang Group of North China-using a suite of characterization approaches: scanning electron microscopy (SEM), transmission electron microscopy (TEM), and focused ion beam scanning electron microscopy (FIB-SEM). Although the Ruyang acritarchs must have had nuclei when alive, our data suggest that their ICIs represent neither fossilized nuclei nor taphonomically condensed cytoplasm. We instead propose that these ICIs likely represent biologically contracted and consolidated eukaryotic protoplasts (the combination of the nucleus, surrounding cytoplasm, and plasma membrane). As opposed to degradational contraction of prokaryotic cells within a mucoidal sheath-a model proposed to explain the Bitter Springs ICIs-our model implies that protoplast condensation in the Ruyang acritarchs was an in vivo biologically programmed response to adverse conditions in preparation for encystment. While the discovery of bona fide nuclei in Paleoproterozoic acritarchs would be a substantial landmark in our understanding of eukaryote evolution, the various processes (such as degradational and biological condensation of protoplasts) capable of producing nuclei-mimicking structures require that interpretation of ICIs as fossilized nuclei be based on comprehensive investigations.

Immunomodulatory and anti-inflammatory properties of artesunate in experimental colitis

BACKGROUND

Inflammatory bowel disease is a chronic and idiopathic gastrointestinal inflammation mediated by disregulated immune responses. Artemisinin (a chemical from a traditional Chinese herbal medicine Artemisia annua L.) and its derivatives have been proven to exhibit anti-inflammatory and immunomodulatory effects in the treatment of systemic lupus erythematosus and rheumatoid arthritis with low side-effects. This study is aimed to evaluate the potential therapeutic value of artesunate for inflammatory bowel disease.

METHODS

Murine colitis was induced by either oral administration of dextran sulfate sodium salt (DSS) or intrarectal delivery of 2,4,6- trinitrobenzene sulfonic acid (TNBS) or oxazolone. Mice were treated with artesunate (150mg/kg/day). Peritoneal macrophages were stimulated with lipopolysaccharide (LPS) in the presence or absence of artesunate. Changes in cytokines or proteins of interests were analyzed by enzyme-linked immunosorbent assay (ELISA) or SDS-PAGE/Western blot.

RESULTS

Artesunate significantly ameliorated DSS colitis and TNBS colitis (but not oxazolone colitis), including reduced weight loss and disease activity, as well as macroscopic and microscopic colonic injury. The expression of NF-κBp65 and p-IκB-α were reduced in artesunate treated TNBS colitis compared with untreated. The levels of IFN-γ, IL-17, and TNF-α were significantly decreased in artesunate treated TNBS colitis or DSS colitis. Furthermore, in vitro artesunate treatment significantly inhibited TNF-α production by LPS-activated macrophages.

CONCLUSIONS

Artesunate suppresses TNF-α expression in vitro and in vivo as well as T-helper (Th)1/Th17 responses in TNBS colitis model. Our data suggest a novel clinical application of artesunate as a potential therapy for Crohn's disease.

Low-dose arsenic induces chemotherapy protection via p53/NF-κB-mediated metabolic regulation

Most chemotherapeutical drugs kill cancer cells chiefly by inducing DNA damage, which unfortunately also causes undesirable injuries to normal tissues, mainly due to p53 activation. We report a novel strategy of normal tissue-protection that involves p53/NF-κB coordinated metabolic regulation. Pretreatment of untransformed cells with low doses of arsenic induced concerted p53 suppression and NF-κB activation, which elicited a marked induction of glycolysis. Significantly, this metabolic shift provided cells effective protection against cytotoxic chemotherapy, coupling the metabolic pathway to cellular resistance. Using both in vitro and in vivo models, we demonstrated an absolute requirement of functional p53 in arsenic-mediated protection. Consistently, a brief arsenic-pretreatment selectively protected only normal tissues but not tumors from toxicity of chemotherapy. An indispensable role of glycolysis in protecting normal tissues was demonstrated by using an inhibitor of glycolysis, 2-deoxyglucose, which almost totally abolished low-dose arsenic-mediated protection. Together, our work demonstrates that low-dose arsenic renders normal cells and tissues resistance to chemotherapy-induced toxicity by inducting glycolysis.

Development and characterization of SCAR markers linked to the citrus tristeza virus resistance gene from Poncirus trifoliata

Twelve new dominant randomly amplified polymorphic DNA (RAPD) fragments associated with a single dominant gene for resistance to citrus tristeza virus (CTV) were identified using bulked segregant analysis of an intergeneric backcross family. These and eight previously reported RAPDs were mapped in the resistance gene (Ctv) region; the resulting localized linkage map spans about 32 cM, with nine close flanking markers within 2.5 cM of Ctv. Seven of 20 RAPD fragments linked with the resistance gene were cloned and sequenced, and their sequences were used to design longer primers to develop sequence characterized amplified region (SCAR) markers that can be utilized reliably in marker-assisted selection, high-resolution mapping, and map-based cloning of the resistance gene. All seven cloned RAPDs were converted successfully into SCARs by redesigning primers, optimizing PCR parameters (especially the annealing temperature), or digesting amplification products with restriction enzymes. Four of the seven remained dominant markers, displaying presence-absence polymorphism patterns; the other three detected restriction site changes or length variations and thus were transformed into codominant markers. Two genomic regions rich in variability were also detected by two codominant SCAR markers.

Thermally-induced structural and chemical alteration of organic-walled microfossils: an experimental approach to understanding fossil preservation in metasediments

The identification and confirmation of bona fide Archean-Paleoproterozoic microfossils can prove to be a challenging task, further compounded by diagenetic and metamorphic histories. While structures of likely biological origin are not uncommon in Precambrian rocks, the search for early fossil life has been disproportionately focused on lesser thermally altered rocks, typically greenschist or lower-grade metamorphism. Recently, however, an increasing number of inferred micro- and macrofossils have been reported from higher-grade metasediments, prompting us to experimentally test and quantify the preservability of organic-walled microfossils over varying durations of controlled heating and under two differing redox conditions. Because of their relatively low-intensity natural thermal alteration, acritarchs from the Mesoproterozoic Ruyang Group were chosen as subjects for experimental heating at approximately 500°C, with durations ranging from 1 to 250 days and in both oxic (normal present day conditions) and anoxic conditions. Upon extraction, the opacity, reflectivity, color, microchemistry, and microstructures of the heated acritarchs were characterized using optic microscopy, scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The results differ for acritarchs prepared under oxic vs. anoxic conditions, with the anoxic replicates surviving experimental heating longer and retaining biological morphologies better, despite an increasing degree of carbonization with continuous heating. Conversely, the oxic replicates show aggressive degradation. In conjunction with fossils from high-grade metasediments, our data illustrate the preservational potential of organic-walled microfossils subjected to metamorphism in reducing conditions, offer insights into the search for microfossils in metasediments, and help to elucidate the influence of time on the carbonization/graphitization processes during thermal alteration.

Surface-enhanced Raman spectroscopy: nonlocal limitations

Giant field enhancement and field singularities are a natural consequence of the commonly employed local-response framework. We show that a more general nonlocal treatment of the plasmonic response leads to new and possibly fundamental limitations on field enhancement with important consequences for our understanding of surface-enhanced Raman spectroscopy (SERS). The intrinsic length scale of the electron gas serves to smear out assumed field singularities, leaving the SERS enhancement factor finite, even for geometries with infinitely sharp features. For silver nanogroove structures, mimicked by periodic arrays of half-cylinders (up to 120 nm in radius), we find no enhancement factors exceeding 10 orders of magnitude (10(10)).

Psychosocial processes influencing weight management among persons newly prescribed atypical antipsychotic medications

The purpose was to generate a theory of the psychosocial processes influencing weight management among persons newly prescribed atypical antipsychotic medications. A grounded theory research design was used to guide the study. Semi-structured interviews were the method of data collection, and analysis was performed using constant comparison. Using theoretical sampling, a sample of 11 participants with first-episode psychosis prescribed atypical antipsychotics for at least 8 weeks, and five participants with a diagnosis of chronic schizophrenia prescribed atypical antipsychotic medication for at least 3 years were recruited from an outpatient psychiatric programme. Contextual factors influencing weight management were: accessibility to resources, unstructured lifestyle, and others' perception of weight. Conditions influencing weight management were: rapid weight gain, insatiable hunger and lack of motivation boosters. Participants' early responses to weight gain included discontinuing medications, choosing lower-calorie foods, using walking in daily activities as exercise, accepting weight gain and trying to manage weight but giving up. The consequences revealed from data analysis were contemplating weight management and not trying, as the barriers to weight management exceeded the facilitators. The theoretical framework developed in this study can assist with the understanding and management of weight gain among this unique population.

Fractionated radiation-induced acute encephalopathy in a young rat model: cognitive dysfunction and histologic findings

BACKGROUND AND PURPOSE

Radiation-induced cognitive dysfunction is a common and serious complication after radiation therapy of brain tumor, yet knowledge of its mechanism is poorly understood. The aim of this study was to establish a young rat model for acute radiation encephalopathy, at both cognitive and pathologic levels, induced by fractionated irradiation.

MATERIALS AND METHODS

Four-week-old male rats were randomized into sham (0 Gy) and 2 experimental groups receiving fractionated irradiation of 5 Gy/day, 5 days/week, with total doses of 20 and 40 Gy, respectively. Cognition, BBB integrity, and potential astrogliosis were evaluated at 0, 4, 8, and 12 weeks' postirradiation.

RESULTS

Twenty-Gy irradiation led to transient cognitive impairment only at 4 weeks' postirradiation. Forty-Gy irradiation induced cognitive impairment at both 4 and 8 weeks' postirradiation, which was more severe than that induced by 20 Gy. Cognitive impairment was accompanied by a transient increase in BWC only at 4 weeks for the 40-Gy group. Disrupted BBB permeability was detected at 4 and 8 weeks' postirradiation for the 20-Gy group, and at 4, 8, and 12 weeks' postirradiation for 40-Gy group, respectively. Increased astrogliosis in the hippocampus could be detected at 4 weeks' postirradiation for 40-Gy group.

CONCLUSIONS

Fractionated irradiation in this experiment could induce acute brain injury, leading to cognitive impairment in young rats. BBB disruption might be a sensitive index for acute radiation encephalopathy. In addition, reactive astrogliosis might play an important role in this process. The present model, especially the 40-Gy irradiation group, is useful for basic and therapeutic studies of acute radiation encephalopathy.

Effects of diet, packaging, and irradiation on protein oxidation, lipid oxidation, and color of raw broiler thigh meat during refrigerated storage

This study was designed to evaluate the effects of dietary treatment, packaging, and irradiation singly or in combination on the oxidative stability of broiler chicken thigh meat. A total of 120 four-week-old chickens were divided into 12 pens (10 birds/pen), and 4 pens of broilers were randomly assigned to a control oxidized diet (5% oxidized oil) or an antioxidant-added diet [500 IU of vitamin E + 200 mg/kg of butylated hydroxyanisole (BHA)] and fed for 2 wk. After slaughter, thigh meats were separated, ground, packaged in either oxygen-permeable or oxygen-impermeable vacuum bags, and irradiated at 0 or 3 kGy. Lipid oxidation (TBA-reactive substances), protein oxidation (carbonyl), and color of the meat were measured at 1, 4, and 7 d of refrigerated storage. The lipid and protein oxidation of thigh meats from birds fed the diet supplemented with antioxidants (vitamin E + BHA) was significantly lower than the lipid and protein oxidation of birds fed the control diet, whereas the lipid and protein oxidation of broilers fed the oxidized oil diet was higher than that of birds fed the control diet. Vacuum packaging slowed, but irradiation accelerated, the lipid and protein oxidation of thigh meat during storage. Dietary antioxidants (vitamin E + BHA) and irradiation treatments showed a stronger effect on lipid oxidation than on protein oxidation. A significant correlation between lipid and protein oxidation in meat was found during storage. Dietary supplementation of vitamin E + BHA and the irradiation treatment increased the lightness and redness of thigh meat, respectively. It is suggested that appropriate use of dietary antioxidants in combination with packaging could be effective in minimizing oxidative changes in irradiated raw chicken thigh meat.

Evidence for the adaptive evolution of ORF5 gene of Porcine reproductive and respiratory syndrome virus isolated in China

Porcine reproductive and respiratory syndrome virus (PRRSV) ORF5 gene encoding an envelope glycoprotein involved in humoral immunity is the most variable protein-coding gene of PRRSV. The present study aimed to identify potential selective pressures acting on the ORF5 gene of PRRSV isolates of North American type prevalent in China. The non-synonymous to synonymous rate ratio ω (dN/dS) was employed as a measure of selective pressure at the codon level. An overall ω of 0.45 indicated negative (purifying) selection as the major driving force operating on the ORF5 gene during adaptation of the virus to swine. Determination of ω values for individual amino acids sites revealed 8 positively selected sites, most of them situated in the N-terminal ectodomain, indicating their potential role in the binding of virus to the cellular receptors. Further, 75 negatively selected sites were identified in the rest of molecule, probably as a result of functional or immunological constraints. Determination of potential N-glycosylation sites revealed 7 sites, four of which coincided with the positively selected ones. These results indicated that a specific adaptive evolution has operated on the ORF5 gene of Chinese PRRSV isolates. It is hoped that the disclosed adaptive sites might help identify a candidate antigenic epitope for the use in vaccine against this serious swine disease.

Reactive uptake kinetics of NO3 on multicomponent and multiphase organic mixtures containing unsaturated and saturated organics

We investigated the reactive uptake of NO(3) (an important night-time oxidant in the atmosphere) on binary mixtures containing an unsaturated organic (methyl oleate) and saturated molecules (diethyl sebacate, dioctyl sebacate, and squalane) which we call matrix molecules. These studies were carried out to better understand the reactivity of unsaturated organics in multicomponent and multiphase atmospheric particles. For liquid binary mixtures the reactivity of methyl oleate depended on the matrix molecule. Assuming a bulk reaction, H(matrix)√(D(matrix)k(oleate)) varied by a factor of 2.7, and assuming a surface reaction H(matrix)(S)K(matrix)(S)k(oleate)(S) varied by a factor of 3.6, where H(matrix)√(D(matrix)k(oleate) and H(matrix)(S)K(matrix)(S)k(oleate)(S) are constants extracted from the data using the resistor model. For solid-liquid mixtures, the reactive uptake coefficient depended on exposure time: the uptake decreased by a factor of 10 after exposure to NO(3) for approximately 90 min. By assuming either a bulk or surface reaction, the atmospheric lifetime of methyl oleate in different matrices was estimated for moderately polluted atmospheric conditions. For all liquid mixtures, the lifetime was in the order of a few minutes (with an upper limit of 35 min). These lifetimes can be used as lower limits to the lifetimes in semi-solid mixtures. Our studies emphasize that the lifetime of unsaturated organics (similar to methyl oleate) is likely short if the particle matrix is in a liquid state.

Relationship between heat shock protein 70 and B amyloids in patients with alzheimer disease and vascular dementia

Aims

Explore the relationship between levels of plasma Aβ1–40, Aβ1–42 and heat shock protein 70 (HSP70) in patients with Alzheimer disease (AD) and vascular dementia (VD) and in elderly non-demented controls.

Methods

23 patients with AD and 21 patients with VD who meet diagnostic criteria of the Diagnostic Statistical Manual 4th edition and 20 control subjects were enrolled, administered the Mini-Mental State Exam (MMSE) and the Activity of Daily Living (ADL) inventory and their levels of plasma Aβ1–40, Aβ1–42 and HSP70 were measured by sandwich enzyme-linked immunosorbent assay.

Results

The levels of plasma Aβ1–40, Aβ1–42 and the Aβ1–40/Aβ1–42 ratio were not significantly different across groups, but levels of plasma HSP70 in VD patients was significantly higher than in AD patients and in normal controls (3.19 vs 1.91 vs 1.43ng/ml, respectively; F=6.464, P=0.003). In the AD group MMSE scores were inversely correlated with ADL scores (r=-0.617, P=0.002) and with levels of plasma HSP70 (r=-0.437, P=0.037); but HSP70 levels were positively correlated with age (r=0.616, P=0.002) and with plasma Aβ1–40 (r=0.497, P=0.016) in AD group. In the VD group levels of plasma HSP70 were positively correlated with plasma Aβ1–40 (r=0.436, P=0.048).

Conclusions

Our findings provide further evidence that high plasma HSP70 levels may play a role in the diagnosis and differential diagnosis of AD. HSP70 levels in AD patients is inversely associated with cognitive performance and positively correlated with plasma Aβ1–40. Plasma HSP70 in VD patients is significantly elevated and positively correlated with plasma Aβ1–40.

Gynandroblastoma with the symptoms of infertility and secondary amenorrhea: a case report

The case of a female patient who failed to get pregnant due to delayed menstruation is reported. Gynecological examination showed that the patient had a male pubic distribution, hypertrophic clitoris, unobstructed vagina and hypertrophic cervices with smooth and medium texture. B ultrasonic examination detected a 42 x 30 mm in size medium echo mass. This mass had irregular shape, smooth surface, relatively clear boundary and hard texture. Examination with paraffin-embedded section indicated that the tumor was composed of supporting cells and to a lesser amount of interstitial components. Some regions had particle-like cell differentiation. These results suggested that the tumor was gynandroblastoma. We found that the increased level of serum testosterone in the patient was the reason for amenorrhea and infertility. The diagnosis and treatment for patients with gynandroblastoma is also discussed.

Metamaterial localized resonance sensors: prospects and limitations

The prospects and limitations of metamaterial localized resonance sensors are investigated theoretically and experimentally. Gold split-ring resonators are employed as the model system where the light induced LC-resonance yields a figure-of-merit, sensitivity divided by linewidth, up to 54 depending on the split-ring resonator design and engineering of the light-plasmon coupling. This highest measured value is comparable to quasi-static predictions, suggesting incremental improvements beyond this point. Further optimization attempts show the effect of inhomogeneous broadening giving some indication that the limits have been reached for this particular design and material choice.

A 6-bp deletion in the TYRP1 gene causes the brown colouration phenotype in Chinese indigenous pigs

Brown coat colour has been described in Chinese-Tibetan, Kele, and Dahe pigs. Here, we report the identification of a causal mutation underlying the brown colouration. We performed a genome-wide association study (GWAS) on Tibetan and Kele pigs, and found that brown colours in Chinese breeds are controlled by a single locus on pig chromosome 1. By using a haplotype-sharing analysis, we refined the critical region to a 1.5-Mb interval that encompasses only one pigmentation gene: tyrosinase-related protein 1 (TYRP1). Mutation screens of sequence variants in the coding region of TYRP1 revealed a strong candidate causative mutation (c.1484_1489del). The protein-altering deletion showed complete association with the brown colouration across Chinese-Tibetan, Kele, and Dahe breeds by occurring exclusively in brown pigs (n=121) and lacking in all non-brown-coated pigs (n=745) from 27 different breeds. The findings provide the compelling evidence that brown colours in Chinese indigenous pigs are caused by the same ancestral mutation in TYRP1. To our knowledge, this study gives the first description of GWAS identifying causal mutation for a monogenic trait in the domestic pig.

Assessing facilitative responses to a nurse shrub at the community level: the example of Potentilla fruticosa in a sub-alpine grassland of northwest China

Biotic interaction studies have revealed a large discrepancy among experiments in target responses to the effects of neighbours, which may in part be due to both high species-specificity of plant responses and low number of target species used in experiments. Our aim was to assess facilitative responses at the community level and the role of both functional groups and ecological attributes of target species. In a sub-alpine grassland on the eastern Tibet plateau, we assessed growth responses of all species in the community to removal of a dominant shrub. We also measured changes in the main environmental variables. Species responses were analysed by functional group and in relation to their mean regional altitudinal distribution. All significant interactions were positive and affected one-third of the total species richness of the community. All functional groups were facilitated but forbs were less strongly facilitated than in the two other groups. High-alpine species were less strongly facilitated than low-sub-alpine species, but the strength of this relationship was weaker than that reported in previous work. There was evidence of a decrease in extreme temperatures below the canopy of the shrub but no variations in soil moisture. We conclude that the highly stressful conditions induced by the dry continental climate of the eastern Tibet plateau are a main driver of the exclusive dominance of positive interactions. Assessing interactive responses at the community level is likely to provide a useful tool to better understand the role of biotic interactions in community responses to environmental changes.

Erythropoietin prevents reactive oxygen species generation and renal tubular cell apoptosis at high glucose level

Erythropoietin (EPO) can induce a series of cytoprotective effects in many non-hematopoietic tissues through interaction with the erythropoietin receptor (EPOR), but whether EPO can prevent the overproduction of reactive oxygen species (ROS) and apoptosis in diabetes remains unclear. Here, we report that renal tubular cells possess EPOR and that EPO reduces high glucose-induced oxidative stress in renal tubular cells. Further, we found that EPO inhibited high glucose-induced renal tubular cell apoptosis and that this protective effect was dependent on reduction of Bax/caspase-3 expression as well as elevation of Bcl-2 expression. Our results suggest that EPO can inhibit high glucose-induced renal tubular cell apoptosis through direct effect on anti-oxidative stress and that EPOR may play a key role in this process.

Characteristics of young rural Chinese suicides: a psychological autopsy study

BACKGROUND

Patterns of suicide rates in China differ in many ways from those in the West. This study aimed to identify the risk factors characteristic for young rural Chinese suicides.

METHOD

This was a case-control psychological autopsy (PA) study. The samples were suicides and living controls (both aged 15-34 years) from 16 rural counties of China. We interviewed two informants for each suicide and each control with pretested and validated instruments to estimate psychosocial, psychiatric and other risk factors for suicides.

RESULTS

The prevalence of mental disorders was higher among the young Chinese who died by suicide than among the living controls, but was lower than among suicides in the West. Marriage was not a protecting factor for suicide among young rural Chinese women, and never-married women who were involved in relationships were about three times more likely to commit suicide than single women who were unattached. Religion/religiosity was not a protecting factor in Chinese suicide, as it tended to be stronger for suicides than for controls. Impulsivity was significantly higher for suicides than for controls. Psychological strain, resulting from conflicting social values between communist gender equalitarianism and Confucian gender discrimination, was associated significantly with suicide in young rural Chinese women, even after accounting for the role of psychiatric illness.

CONCLUSIONS

Risk factors for suicide in rural China are different from those in the West. Psychological strain plays a role in suicide. Suicide prevention programs in China should incorporate culture-specific considerations.

An experimental study of acute radiation-induced cognitive dysfunction in a young rat model

BACKGROUND AND PURPOSE

Radiation-induced cognitive dysfunction is a common and serious clinical complication after radiation therapy for a brain tumor, but the knowledge of its mechanism is poorly understood. The purpose of this study was to establish a young rat model for acute radiation-induced cognitive dysfunction and associated BBB damage, as well as histopathologic changes.

MATERIALS AND METHODS

Young male rats were randomized into 4 groups to receive irradiation treatments at 300 cGy/min with doses of 0 (sham), 10, 20, and 40 Gy, respectively. Each treatment group was further randomized into 4 subgroups for following up cognitive tests and assessment of their BBB integrity and potential histopathologic changes at 0, 7, 20, and 60 days.

RESULTS

We found that irradiation at 10 Gy failed to induce any significant effects. Irradiation at 20 Gy resulted in a transient impairment of the cognitive functions at 7 and 20 days and returned to normal at 60 days. Irradiation at 40 Gy caused the severest cognitive impairment, which peaked at 7 days, and lasted for at least 60 days. The impaired cognition in both the 20-Gy and 40-Gy-irradiated rats was more or less accompanied with increased brain water content and deteriorated BBB function, though mild histopathologic alternations were only noticed in the 40-Gy-irradiated rats at 20 days.

CONCLUSION

A single-dose exposure at 20 to 40 Gy is sufficient to induce acute brain injury at both cognitive and pathologic levels in young male rats. In addition, morphologic outcomes may not be sensitive enough to reveal all of the pathologic changes, whereas BBB disruption may be an earlier and more sensitive index for acute RE. Therefore, the present model is useful for basic and therapeutic studies of acute RE.

Thin film Ag superlens towards lab-on-a-chip integration

A thin metal film near-field superlens, as originally suggested by Pendry and realized by Fang et al. and Melville et al., is investigated with emphasis on materials suitable for integration on a lab-on-a-chip platform. A chemically resistant cyclo-olefin copolymer (COC), mr-I-T85 from microresist technology, is applied as dielectric matrix/spacer for an Ag thin film superlens. The superlens successfully resolves 80 nm half-pitch gratings when illuminated with UV radiation at a free space wavelength of 365 nm. The superlens design, fabrication and characterization is discussed.

When to conduct a renal impairment study during drug development: US Food and Drug Administration perspective

To optimize drug therapy for individuals, it is critical to understand how various intrinsic (e.g., age, gender, race, genetics, organ impairment) and extrinsic factors (e.g., diet, smoking, concomitantly administered drugs) affect drug exposure and response.(1) Up to now, it has been far easier to discover effects on exposure caused by these factors, and the US Food and Drug Administration (FDA) has published several guidance documents with recommendations on how to evaluate these factors during drug development.

5-HT 3 receptors mediate the time-dependent vagal afferent modulation of nociception during chronic food allergen-sensitized visceral hyperalgesia in rats

Converging lines of evidence demonstrate a vagally mediated antinociceptive pathway in animals undergoing acute visceral insults, the contribution of this system to visceral pain following chronic noxious stimuli is unknown. 5-HT(3) receptor (5-HT(3)Rs) on spinal afferents are crucially involved in nociceptive processing, the role of 5-HT(3)Rs on vagal afferents is unclear. The aim of the present study was to determine the contribution of vagal afferents to visceral nociception in rats undergoing chronic luminal allergen stimulation and whether it involves vagal 5-HT(3)Rs. Sensitized rats received chicken egg albumin (EA, 1 mg mL(-1)) in drinking water for 2 weeks (day 1-14). Visceromotor response (VMR) to colorectal distension [colorectal distension (CRD), 60 mmHg] and the levels of mRNA encoding 5-HT(3)R (including 3A and 3B subunits) in the nodose ganglia (NG) were evaluated on day 2, 4, 8 and 15. Chronic EA challenge induced gradually increased visceral nociception, with a peak on day 15. Subdiaphragmatic vagotomy or functional deafferentation with capsaicin abolished this time-dependent manner, inducing hyperalgesia from day 2, lasting to day 15. Intraluminal infusion of a 5-HT(3)R antagonist (granisetron), whether alone or infused after local mucosa anaesthetic with 1% lidocaine, mimicked the effects of vagotomy. The mRNA levels for 5-HT(3B) or 5-HT(3A) subunit in the NG showed an opposite time-course to that of visceral pain, which increased from day 2, then decreased gradually to levels lower than those of controls. Our results demonstrate a time-dependent vagal afferent modulation of chronic allergen-sensitized visceral hyperalgesia, which may involve a 5-HT(3)R pathway.

Real-time PCR analysis of the heat-shock response of Acidithiobacillus ferrooxidans ATCC 23270

As one of the most important bioleaching bacterial species, Acidithiobacillus ferrooxidans is subjected to different kinds of environmental stress such as temperature changes, presence of some toxic heavy metals or pH changes, which normally take place in bioleaching operations and may affect the activity of the bacteria. To obtain further knowledge of the protective mechanisms employed by A. ferrooxidans in response to elevated growth temperature, temporal gene expression profiles were examined in cells subjected to heat stress by using real-time PCR. The majority of predicted genes, including those encoding chaperones and heat-shock proteins, were significantly up-regulated (P < 0.05 and the fold change >or= 2.0) over a 25-min period after upshift to the heatshock temperature (from 30 to 42 degrees C) and then decrease to readjust their transcript levels to a new steady state at 42 degrees C. Finally, based on the gene expression data and computational analysis, a putative regulatory site having T-T-T-T-T-T-n-n in the -35 region and n-T-A-T-n-A-T-C in the -10 region with average 19 base pairs separating the two elements was predicted upstream of a number of heat-inducible genes.