Effect of penehyclidine hydrochloride on β-arrestin-1 expression in lipopolysaccharide-induced human pulmonary microvascular endothelial cells

β-arrestins are expressed proteins that were first described, and are well-known, as negative regulators of G protein-coupled receptor signaling. Penehyclidine hydrochloride (PHC) is a new anti-cholinergic drug that can inhibit biomembrane lipid peroxidation, and decrease cytokines and oxyradicals. However, to date, no reports on the effects of PHC on β-arrestin-1 in cells have been published. The aim of this study was to investigate the effect of PHC on β-arrestin-1 expression in lipopolysaccharide (LPS)-induced human pulmonary microvascular endothelial cells (HPMEC). Cultured HPMEC were pretreated with PHC, followed by LPS treatment. Muscarinic receptor mRNAs were assayed by real-time quantitative PCR. Cell viability was assayed by the methyl thiazolyl tetrazolium (MTT) conversion test. The dose and time effects of PHC on β-arrestin-1 expression in LPS-induced HPMEC were determined by Western blot analysis. Cell malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were measured. It was found that the M3 receptor was the one most highly expressed, and was activated 5 min after LPS challenge. Furthermore, 2 μg/mL PHC significantly upregulated expression of β-arrestin-1 within 10 to 15 min. Compared with the control group, MDA levels in cells were remarkably increased and SOD activities were significantly decreased in LPS pretreated cells, while PHC markedly decreased MDA levels and increased SOD activities. We conclude that PHC attenuated ROS injury by upregulating β-arrestin-1 expression, thereby implicating a mechanism by which PHC may exert its protective effects against LPS-induced pulmonary microvascular endothelial cell injury.

Two-port laparoscopic cholecystectomy with modified suture retraction of the fundus: A practical approach

CONTEXT

Although transumbilical single incision laparoscopic cholecystectomy (SILC) has been demonstrated to be superior cosmetic, it is only limited to simple cases at present. In complex cases, the standard four- or three-port LC is still the treatment of choice.

AIM

To summarize the clinical effect of a modified technique in two-port LC.

SETTINGS AND DESIGN

A consecutive series of patients with benign gallbladder diseases admitted to the provincial teaching hospital who underwent LC in the past 4 years were included. A modified two-port LC was the first choice except for those requiring laparoscopic common bile duct exploration (LCBDE).

MATERIALS AND METHODS

The operation was done with suture retraction of the fundus by a needle-like retractor. The patients' data, including the operative time, time consumed by gallbladder retraction, operative bleeding, conversion rate, rate of adding trocars, and postoperative complications were recorded.

STATISTICAL ANALYSIS

Data were expressed as percentage and mean with standard deviation.

RESULTS

Total 107 patients with chronic calculous cholecystitis (N = 61), acute calculous cholecystitis (N = 43), and cholecystic polyps (N = 3) received two-port LC. The procedure was successful in 99 out of 107 cases (success rate, 92.5%), and a third trocar was added in the remaining 8 cases (7.5%) due to severe pathological changes. The operative time was 47.2 (±13.21) min. There was no conversion to open surgery.

CONCLUSION

Two-port LC using a needle-like retractor for suture retraction of the gallbladder fundus is a practical approach when considering the safety, convenience, and indications as well as relatively minimal invasion.

Nitrite reduces acute lung injury and improves survival in a rat lung transplantation model

Ischemia/reperfusion injury (IRI) is the most common cause of early mortality following lung transplantation (LTx). We hypothesized that nitrite, an endogenous source of nitric oxide (NO), may protect lung grafts from IRI. Rat lung grafts were stored in preservation solution at 4°C for 6 hours. Both grafts and recipients were treated with nitrite. Nitrite treatment was associated with significantly higher levels of tissue oxygenation, lower levels of cytokines and neutrophil/macrophage infiltration, lower myeloperoxidase activity, reduced oxidative injury and increased cGMP levels in grafts than in the controls. Treatment with either a nitric oxide scavenger or a soluble guanylyl cyclase (sGC) inhibitor diminished the beneficial effects of nitrite and decreased cGMP concentrations. These results suggest that nitric oxide, generated from nitrite, is the molecule responsible for the effects of nitrite via the nitric oxide/sGC/cGMP pathway. Allopurinol, a xanthine oxidoreductase (XOR) inhibitor, abrogated the protective effects of nitrite, suggesting that XOR is a key enzyme in the conversion of nitrite to nitric oxide. In vitro experiments demonstrated that nitrite prevented apoptosis in pulmonary endothelial cells. Nitrite also exhibits longer survival rate in recipients than control. In conclusion, nitrite inhibits lung IRI following cold preservation and had higher survival rate in LTx model.

Synovial fluid dynamics with small disc perforation in temporomandibular joint

The articular disc plays an important role as a stress absorber in joint movement, resulting in stress reduction and redistribution in the temporomandibular joint (TMJ). The flow of synovial fluid in the TMJ may follow a regular pattern during movement of the jaw. We hypothesised that the regular pattern is disrupted when the TMJ disc is perforated. By computed tomography arthrography, we studied the upper TMJ compartment in patients with small disc perforation during jaw opening-closing at positions from 0 to 3 cm. Finite element fluid dynamic modelling was accomplished to analyse the pattern of fluid flow and pressure distribution during the movements. The results showed that the fluid flow in the upper compartment generally formed an anticlockwise circulation but with local vortexes with the jaw opening up to 2 cm. However, when the jaw opening-closing reached 3 cm, an abnormal flow field and the fluid pressure change associated with the perforation may increase the risk of perforation expansion or rupture and is unfavourable for self-repair of the perforated disc.

A comparison of potency of and intracellular signaling events provoked by, small molecule and protein-based mpl agonists

e14624

Background: Thrombopoietin (TPO) interacts with its receptor (mpl) to initiate signal transduction and increase platelet production. Other mpl agonists have been developed for clinical use: MDGF (a recombinant protein) and romiplostim (a peptibody) are protein-based mpl agonists; eltrombopag (a small molecule) is a nonpeptide mpl agonist. Methods: Mpl agonists were compared for their ability to induce cellular responses and activate relevant signaling pathways in mpl-expressing cells. Proliferation was assessed by ATP bioluminescence in Baf3/mpl cells treated with mpl agonists for 2 days. Differentiation was assessed by flow cytometric-detection of CD41 and CD61 expression on human CD34+ cells cultured with mpl agonists for 7 days. Activation of signaling pathways was determined by Western blot analysis of proteins from serum-starved Baf3/mpl cells treated with mpl agonists for 20 minutes. Experiments were repeated 3 or more times. Results: The TPO concentration that produced a half-maximal (EC50) proliferative response of Baf3/mpl cells was comparable with that of romiplostim (Table). In contrast, a 30-fold greater concentration of MGDF and a 2,000-fold greater concentration of small molecule were required to produce the same degree of proliferation. In addition, a 1,000,000-fold greater concentration of small molecule compared with romiplostim was required to produce an EC50 for differentiation of CD34+ cells. Mpl agonists activated identical signaling pathways in Baf3/mpl cells: a similar dose-response for phosphorylation of JAK2, Stat3, Stat5, Erk1/2, and AKT was observed at their respective EC10, EC50, and EC100 concentrations. Conclusions: In Baf3/mpl cells, the small molecule was between 1,000- and 1,000,000-fold less potent than protein-based mpl agonists when corrected for molecular mass differences. Small molecule and protein-based mpl agonists were indistinguishable when mpl intracellular signaling was compared at similarly effective concentrations. [Table: see text]

[Table: see text]

A comparison of the effect of total intravenous anaesthesia with propofol and remifentanil and inhalational anaesthesia with isoflurane on the release of pro- and anti-inflammatory cytokines in patients undergoing open cholecystectomy

The aim of the study was to investigate the effects of two anaesthetic techniques (total intravenous technique vs. inhalational technique) on changes in pro- and anti-inflammatory cytokine levels during open cholecystectomy. Forty ASA PS I-II patients undergoing open cholecystectomy were randomly assigned to two groups. Group R received total intravenous anaesthesia with propofol and remifentanil and group F received balanced inhalational anaesthesia with isoflurane. The plasma levels of tumour necrosis factor-alpha (TNF-alpha), interleukin IL-6 and interleukin IL-10 were measured during and after surgery. The pro-inflammatory cytokine levels (TNF-alpha and IL-6) and the anti-inflammatory cytokine (IL-10) showed a significant increase in their concentrations compared with pre-induction levels in both groups (P < 0.05). By the end of anaesthesia and surgery, TNF-alpha and IL-6 were significantly lower in group R than in group F (P < 0.05). At the end of anaesthesia and 12 hours postoperatively, IL-10 levels in group R were higher than in group F (P < 0.05). These findings suggest that total intravenous anaesthesia using propofol and remifentanil suppresses the inflammatory response caused by surgery to a greater extent than a balanced inhalation technique using isoflurane.

Clonal turnover of MACE-carrying peach-potato aphids (Myzus persicae (Sulzer), Homoptera: Aphididae) colonizing Scotland

Peach-potato aphids, Myzus persicae (Sulzer), collected in Scotland in the years 1995 and 2002-2004 were characterized using four microsatellite loci and three insecticide resistance mechanisms. From 868 samples, 14 multilocus genotypes were defined (designated clones A-N). Five of these (denoted A, B, H, M and N) carried modified acetylcholinesterase (MACE) resistance, the most recent resistance mechanism to have evolved in M. persicae. The current paper shows that the continued presence of MACE aphids is due to turnover, as clones A and B were replaced in field samples by clones H, M and N in later seasons. Thus, insecticide-resistant populations in Scotland can be attributed to multiple waves of rapid clone colonisations and not to the continued presence of stable resistant clones or mutation or sexual recombination in local populations. The MACE clones carried varying levels of the other insecticide resistance mechanisms, kdr and esterase. The presence of these mechanisms could alter the clones success in the field depending on insecticide spraying (positive selection) and resistance fitness costs (negative selection).

Sexual reproduction facilitates the adaptation of parasites to antagonistic host environments: Evidence from empirical study in the wheat-Mycosphaerella graminicola system

Most eukaryotes use sexual reproduction to transmit genetic information from generation to generation despite the advantages offered by asexual reproduction. One theory to explain the origin and maintenance of sexual reproduction hypothesises that sexual recombination generates genetic variation that allows faster adaptation to fluctuating and/or stressful environments. We used a combination of ecological, molecular genetic, statistical and experimental evolution approaches to test this hypothesis in an agricultural plant-pathogen system. We inoculated wheat hosts with 10 strains of the fungal pathogen Mycosphaerella graminicola in a field experiment and estimated the contributions of sexual reproduction, asexual reproduction and immigration to the genetic composition of fungal populations sampled from moderately resistant and susceptible hosts through the course of an epidemic cycle. We found that a significant proportion of the M. graminicola population in the late phase of the epidemic originated from sexual reproduction among isolates that had been introduced into the field plots at the beginning of the epidemic. Recombinants were recovered at a higher frequency on the moderately resistant plant host Madsen than on the susceptible host Stephens. By the end of the growing season, we estimated that approximately 13% of the strains sampled from the resistant host were recombinants, compared with 9% in the samples collected from the susceptible host. We also found that pathogen strains originating from the resistant cultivar displayed higher levels of fitness, virulence and fungicide tolerance than those originating from the susceptible cultivar. Our results provide empirical support for the hypothesis that sexual reproduction facilitates the evolution of parasites to overcome host resistance.

Selection for increased cyproconazole tolerance in Mycosphaerella graminicola through local adaptation and in response to host resistance

SUMMARY Sterol demethylation inhibitors (DMIs) represent one of the largest groups of systemic fungicides that have been used to control agriculturally important fungal pathogens. Knowledge regarding the evolution of fungicide resistance in agricultural ecosystems is fragmentary and a better understanding of the processes driving the development of DMI resistance in populations of fungal pathogens is needed by plant pathologists and the agrochemical industry. We considered some of these processes using approaches based on molecular population and quantitative genetics. Five Mycosphaerella graminicola populations sampled from unsprayed wheat fields on four continents were assayed for eight restriction fragment length polymorphism (RFLP) markers and their level of tolerance to cyproconazole. DMI fungicides such as cyproconazole inhibit the enzyme eburicol 14-alpha-demethylase. The gene encoding this target, CYP51, was sequenced for all isolates. We found unimodal, continuous variations in cyproconazole tolerance among the M. graminicola isolates sampled from individual fields, consistent with a polygenic mode of inheritance. We also found that population differentiation for cyproconazole tolerance (Q(ST)) among the five M. graminicola populations was significantly higher than the corresponding population differentiation for neutral RFLP markers (G(ST)), suggesting that selection for cyproconazole tolerance in the Swiss population has already led to local adaptation that can be seen even in an unsprayed population. The Swiss population displayed the highest level of tolerance to cyproconazole, in addition to a lower than expected quantitative variation in fungicide tolerance and a skewed distribution, indicating that selection had increased the overall tolerance of this population. Further analysis with DNA sequencing showed that the population from Switzerland was dominated by isolates with several point mutations and a 6-bp deletion in CYP51. This deletion and one of the point mutations were previously related to increased resistance in field isolates. The fungal population from Oregon sampled from an unsprayed resistant host cultivar displayed the same gene diversity in RFLP loci but higher cyproconazole tolerance and quantitative variation in tolerance than the fungal population from the same field sampled from an unsprayed susceptible host cultivar.

Hippocampal cerebrospinal fluid spaces on MR imaging: Relationship to aging and Alzheimer disease

BACKGROUND AND PURPOSE

Perihippocampal fissures (PHFs) and hippocampal sulcus residual cavities (HSCs) are common findings in the MR imaging examination of the hippocampus in aging and Alzheimer disease (AD); however, little is known about how to distinguish them or their relative clinical relevance. We hypothesized that prominence of the HSC, unlike PHF, is not significantly influenced by the hippocampal atrophy related to aging or AD.

METHODS

We studied and evaluated these hippocampal CSF spaces on MR imaging scans from 130 normal control (NC) subjects (20-90 years of age) and 27 AD patients.

RESULTS

HSC is poorly correlated with age and is not related to the magnitude of hippocampal atrophy. There is no significant difference of HSCs between AD and age-matched NCs, but in the extremely high HSCs group (top 20%), 91% of cases are NC. PHFs, on the other hand, are strongly correlated with age and are valuable in the diagnosis of AD. Location and communication with ambient cistern is the key to distinguish HSC from PHF.

CONCLUSION

Identifying hippocampal atrophy (enlarged PHF) may be particularly challenging in the presence of HSC. Distinguishing among the CSF spaces in hippocampus may help in the radiologic evaluation of hippocampal atrophy. Patients with extremely high HSCs (>8.4) can be excluded from AD risk with 93% specificity.

Variation for neutral markers is correlated with variation for quantitative traits in the plant pathogenic fungus Mycosphaerella graminicola

We compared genetic variation and population differentiation at RFLP marker loci with seven quantitative characters including fungicide resistance, temperature sensitivity, pycnidial size, pycnidial density, colony size, percentage of leaves covered by pycnidia (PLACP) and percentage of leaves covered by lesions (PLACL) in Mycosphaerella graminicola populations sampled from four regions. Wide variation in population differentiation was found across the quantitative traits assayed. Fungicide resistance, temperature sensitivity, and PLACP displayed a significantly higher Q(ST) than G(ST), consistent with selection for local adaptation, while pycnidial size, pycnidial density and colony size displayed a lower or significantly lower Q(ST) than G(ST), consistent with constraining selection. There was not a statistical difference between Q(ST) and G(ST) in PLACL. We also found a positive and significant correlation between genetic variation in molecular marker loci and quantitative traits at the multitrait scale, suggesting that estimates of overall genetic variation for quantitative traits in M. graminicola could be derived from analysis of the molecular genetic markers.