Intraoperative recurrent laryngeal nerve monitoring: a useful method for patients with esophageal cancer

It is well accepted that recurrent laryngeal nerve paralysis is a severe complication of esophagectomy or lymphadenectomy performed adjacent to the recurrent laryngeal nerves. Herein, determination of the effectiveness of implementing continuous recurrent laryngeal nerve monitoring to reduce the incidence of recurrent laryngeal nerve paralysis after esophagectomy was sought. A total of 115 patients diagnosed with esophageal cancer were enrolled in the thoracic section of the Tangdu Hospital of the Fourth Military Medical University from April 2008 to April 2009. Clinical parameters of patients, the morbidity, and the mortality following esophageal resection were recorded and compared. After the surgery, a 2-year follow up was completed. It was found that recurrent laryngeal nerve paralysis and postoperative pneumonia were more frequently diagnosed in the patients that did not receive continuous recurrent laryngeal nerve monitoring (6/61 vs. 0/54). Furthermore, positive mediastinal lymph nodes (P = 0.015), total mediastinal lymph nodes (P < 0.001), positive total lymph nodes (P = 0.027), and total lymph nodes (P < 0.001) were more often surgically removed in the patients with continuous recurrent laryngeal nerve monitoring. These patients also had a higher 2-year survival rate (P = 0.038) after surgery. It was concluded that continuous intraoperative recurrent laryngeal nerve monitoring is technically safe and effectively identifies the recurrent laryngeal nerves. This may be a helpful method for decreasing the incidence of recurrent laryngeal nerve paralysis and postoperative pneumonia, and for improving the efficiency of lymphadenectomy.

First Report of Geosmithia morbida in North Carolina: The Pathogen Involved in Thousand Cankers Disease of Black Walnut

In the past decade, black walnut (Juglans nigra) trees throughout western North America have suffered from widespread branch dieback and canopy loss, causing substantial tree mortality (2,3). The fungus, Geosmithia morbida, vectored by the walnut twig beetle (WTB), Pityophthorus juglandis, has been associated with this devastating disease known as Thousand Cankers Disease (TCD) (2,3). In August of 2012, branch samples from TCD symptomatic black walnut trees (5 to 10 cm in diameter and 15 to 30 cm long) were collected on the North Carolina side of the Great Smoky Mountain National Park (GRSM) in Cataloochee Cove (35°37.023' N, 83°07.351' W) and near the Big Creek Campground (35°45.290' N, 83°06.473' W), in Haywood County. Five symptomatic trees near the Big Creek Campground and three from Cataloochee Cove displayed typical TCD signs including progressive crown thinning, branch flagging, and branch dieback; however, insect holes were not observed. Samples were double bagged in Ziploc plastic bags, sealed in a 19-liter plastic bucket, and transported to the University of Tennessee. Outer bark was removed from the samples and small, elliptical, necrotic cankers were observed. Wood chips (3 to 4 mm²) from cankers were excised and placed on 1/10 strength potato dextrose agar amended with 30 mg/liter streptomycin sulfate and 30 mg/liter chlortetracycline HCL and incubated on a 12-h dark/light cycle at 22°C for 5 to 7 days. Fungal isolates were tentatively identified as G. morbida by using culture morphology, and characteristics of conidiophores and conidia (2). The isolated fungus from the Cataloochee Cove location was grown in 1/10 strength potato dextrose broth at room temperature for 2 weeks. Isolates from Big Creek Campground were contaminated and were not analyzed further. Fungal colonies were tan to light yellow. Conidia were tan, subcylindrical, and catenulate. Conidiophores were multibranched, verticillate, and verrucose. To verify the morphological data, DNA was extracted from fungal mycelia using DNeasy Plant Mini Kit (Qiagen, Valencia, CA) according to the manufacturer's published protocol. Isolates from Cataloochee Cove were characterized using ITS1 and ITS4 universal primers (4). The putative G. morbida isolate (GenBank Accession No. KC461929) had ITS sequences that were 100% identical to the G. morbida type isolate CBS124663 (FN434082.1) (2). Additionally, fungal DNA from Cataloochee Cove was amplified using G. morbida-specific microsatellite loci (GS04, GS27, and GS36) (1). PCR products were analyzed with the QIAxcel Capillary Electrophoresis System (Qiagen) and were similar to those previously published (2). To date, all confirmed cases of TCD in the native range of black walnut have been in urban areas, along rural roadsides and/or fence rows. The report in North Carolina is the first finding of G. morbida, the causal agent of TCD, in a forest setting. References: (1) D. Hadziabdic et al. Conserv. Genet. Resources 4:287, 2012. (2) M. Kolarik et al. Mycologia 103:325, 2011. (3) N. Tisserat et al. Plant Health Progr. doi:10.1094/PHP-2011-0630-01-BR, 2011. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, CA, 1990.

Stevens-Johnson syndrome induced by the cross-reactivity between teicoplanin and vancomycin

WHAT IS KNOWN AND OBJECTIVE

The glycopeptide antibiotics, vancomycin and teicoplanin, are the mainstay of therapy for severe gram-positive organisms such as methicillin-resistant Staphylococcus aureus. We report a case of Stevens-Johnson syndrome (SJS) induced by sequential therapy with teicoplanin and vancomycin, in a patient with chronic obstructive pulmonary disease (COPD).

CASE SUMMARY

A 74-year-old Han Chinese with 1-year history of COPD was admitted for treatment of infective endocarditis. After teicoplanin therapy for 12 days, he developed pruritus and maculopapular over his trunk and limbs. His rash spread rapidly to most parts of the body surface area, 7 days after his anti-infection therapy was switched to vancomycin. This was stopped, but he developed SJS when teicoplanin was re-introduced. This patient recovered from his drug eruptions when both teicoplanin and vancomycin were stopped. Pharmacogenetic analyses revealed he was heterozygous with respect to two variants (rs2844682 of MUC21 and rs750332 of BAG6).

WHAT IS NEW AND CONCLUSION

Cross-reactivity between vancomycin and teicoplanin is rare. SJS attributable to sequential treatment with these two antibiotics has not been reported previously. Care should be taken when prescribing vancomycin in patients with a previous documented skin eruption to teicoplanin, especially in those who carry any susceptibility alleles to SJS/TEN.

Experimental demonstration of optical data links using a hybrid CAP/QAM modulation scheme

The first known experimental demonstrations of a 10  Gb/s hybrid CAP-2/QAM-2 and a 20  Gb/s hybrid CAP-4/QAM-4 transmitter/receiver-based optical data link are performed. Successful transmission over 4.3 km of standard single-mode fiber (SMF) is achieved, with a link power penalty ∼0.4  dBo for CAP-2/QAM-2 and ∼1.5  dBo for CAP-4/QAM-4 at BER=10(-9).

Monolithic MZI-SOA hybrid switch for low-power and low-penalty operation

We report the first experimental demonstration of a monolithically integrated hybrid dilated 2×2 modular optical switch using Mach-Zehnder modulators as low-loss 1×2 switching elements and short semiconductor optical amplifiers to provide additional extinction and gain. An excellent 40 dB cross-talk/extinction ratio is recorded with data-modulated signal-to-noise ratios of up to 44 dB in a 0.1 nm bandwidth. A switching time of 3 ns is demonstrated. Bit error rate studies show extremely low subsystem penalties of less than 0.1 dB, and studies indicate that, by using this hybrid switch building block, an 8×8 port switch could be achieved with 14 dB input power dynamic range for subsystem penalties of less than 0.5 dB.

Effect of bradykinin on renal mesangial cell proliferation and extracellular matrix secretion

Recent studies have found that bradykinin (BK) plays a role in delaying glomerulosclerosis, although the mechanism of this phenomenon remains unclear. Mesangial cell proliferation (MCP) and extracellular matrix (ECM) secretion are important mechanisms for glomerulosclerosis. This study investigated the impact of BK on the platelet-derived growth factor (PDGF)-induced proliferation of mesangial cells, and evaluated its correlations with the extracellular signal-related kinase (ERK) signaling pathway. The results showed that on its own, 10-1000 mg/L BK promoted MCP and ECM secretion and induced ERK phosphorylation. However, BK administration after PDGF pre-incubation inhibited PDGF-induced MCP, ECM secretion, and ERK phosphorylation. The BK B2 receptor-specific antagonist, HOE-140, and tyrosine phosphatase inhibitor (OV) effectively blocked the function of BK. In summary, these results demonstrated that BK has a bidirectional effect on MCP and ECM secretion: when used alone, it promoted effects on these phenomena, but these effects were inhibited when combined with PDGF. This suggests that the role of BK might be achieved through inhibiting activation of the PDGF-induced ERK1/2 pathway.

RhoA/ROCK/PTEN signaling is involved in AT-101-mediated apoptosis in human leukemia cells in vitro and in vivo

R-(-)-gossypol acetic acid (AT-101) is a natural cottonseed product that exhibits anticancer activity. However, the molecular mechanism behind the antileukemic activity of AT-101 has not been well characterized. In this study, we investigated how AT-101 induces apoptosis in human leukemia cells. Exposure to AT-101 significantly increased apoptosis in both human leukemia cell lines and primary human leukemia cells. This increase was accompanied by the activation of caspases, cytochrome c release, Bcl2-associated X protein (Bax) translocation, myeloid cell leukemia-1 (Mcl-1) downregulation, Bcl-2-associated death promoter (Bad) dephosphorylation, Akt inactivation, and RhoA/Rho-associated coiled-coil containing protein kinase 1/phosphatase and tensin homolog (RhoA/ROCK1/PTEN) activation. RhoA, rather than caspase-3 cleavage, mediated the cleavage/activation of ROCK1 that AT-101 induced. Inhibiting RhoA and ROCK1 activation by C3 exoenzyme (C3) and Y27632, respectively, attenuated the ROCK1 cleavage/activation, PTEN activity, Akt inactivation, Mcl-1 downregulation, Bad dephosphorylation, and apoptosis mediated by AT-101. Knocking down ROCK1 expression using a ROCK1-specific siRNA also significantly abrogated AT-101-mediated apoptosis. Constitutively active Akt prevented the AT-101-induced Mcl-1 downregulation, Bad dephosphorylation, and apoptosis. Conversely, AT-101 lethality was potentiated by the phosphatidylinositol 3-kinase inhibitor LY294002. In vivo, the tumor growth inhibition caused by AT-101 was also associated with RhoA/ROCK1/PTEN activation and Akt inactivation in a mouse leukemia xenograft model. Collectively, these findings suggest that AT-101 may preferentially induce apoptosis in leukemia cells by interrupting the RhoA/ROCK1/PTEN pathway, leading to Akt inactivation, Mcl-1 downregulation, Bad dephosphorylation, and Bax translocation, which culminate in mitochondrial injury and apoptosis.

Overexpression of HSP27 in cultured human aortic smooth muscular cells reduces apoptosis induced by low-frequency and low-energy ultrasound by inhibition of an intrinsic pathway

We investigated in vitro the effect of low-frequency and low-energy ultrasound (LFLEU) on apoptosis of an overexpressed HSP27 human aortic smooth muscle cell (HASMC) line. A frequency of 42.6 kHz was used in all experiments. HASMC were exposed to ultrasound and cell viability was evaluated by MTT reduction. Overexpressed HSP27-HASMC was constructed on a pcDNA3.1 vector. Apoptosis was determined 24 h after treatment by flow cytometry; gene display was evaluated with Affimax chips, and HSP27 mRNA and protein expression levels were measured by RT-PCR and Western blotting. The apoptosis rate (at 30 s) was significantly lower in HASMC transfected with HSP27 (7.14 ± 1.73%), compared with cells transfected with a mock plasmid (17.31 ± 2.72%) or a control group (14.23 ± 2.77%), indicating a protective function for apoptosis induced by LFLEU. Gene display analysis showed that caspase-9 expression in HSP27 cell lines was downregulated and caspase-3 upregulated. However, RT-PCR and Western blotting analysis indicated that both caspase-9 and caspase-3 were inhibited at both the mRNA and protein levels. We suggest that overexpressed HSP27 is capable of protecting the LFLEU from apoptosis and that the pathway for this protection is via downregulated caspase-9 and caspase-3 expression.

High glucose represses β-klotho expression and impairs fibroblast growth factor 21 action in mouse pancreatic islets: involvement of peroxisome proliferator-activated receptor γ signaling

Circulating fibroblast growth factor 21 (FGF21) levels are elevated in diabetic subjects and correlate directly with abnormal glucose metabolism, while pharmacologically administered FGF21 can ameliorate hyperglycemia. The pancreatic islet is an FGF21 target, yet the actions of FGF21 in the islet under normal and diabetic conditions are not fully understood. This study investigated the effects of high glucose on islet FGF21 actions in a diabetic mouse model by investigating db/db mouse islet responses to exogenous FGF21, the direct effects of glucose on FGF21 signaling, and the involvement of peroxisome proliferator-activated receptor γ (PPARγ) in FGF21 pathway activation. Results showed that both adult db/db mouse islets and normal islets treated with high glucose ex vivo displayed reduced β-klotho expression, resistance to FGF21, and decreased PPARγ expression. Rosiglitazone, an antidiabetic PPARγ ligand, ameliorated these effects. Our data indicate that hyperglycemia in type 2 diabetes mellitus may lead to FGF21 resistance in pancreatic islets, probably through reduction of PPARγ expression, which provides a novel mechanism for glucose-mediated islet dysfunction.

Association of serum pigment epithelium-derived factor with high-sensitivity C-reactive protein in women with polycystic ovary syndrome

BACKGROUND

The basic studies showed that Pigment epithelium-derived factor (PEDF) plays an important role in inflammation.

AIM

This study aims to investigate the association of serum PEDF with high-sensitivity C-reactive protein (hs-CRP) in women with polycystic ovary syndrome (PCOS).

METHODS

Ninety-six PCOS women and 63 healthy, age-matched controls were enrolled in this study. Serum levels of PEDF, hs-CRP, Complement C3 (C3), glucose, insulin, lipids, and total testosterone were measured. Ninety-six PCOS women and 20 controls underwent hyperinsulinemiceuglycemic clamp to assess their insulin sensitivity, which was expressed as M value.

RESULTS

Serum PEDF levels and hs- CRP levels were much higher in PCOS women than in controls. In PCOS women, PEDF positively correlated with body mass index (BMI), hs-CRP, C3, LDL cholesterol (LDL-c), and systolic blood pressure (SBP), and negatively correlated with M value and HDL cholesterol (HDL-c). After controlling for BMI, PEDF was still positively correlated with hs-CRP. Multiple linear regression analysis revealed that in PCOS women, hs-CRP, SBP, LDL-c and M value were independent determinants of serum PEDF.

CONCLUSION

The serum PEDF levels are closely associated with hs-CRP in women with PCOS. PEDF may play a role in the development of chronic inflammation in PCOS.

Comparison of methods for localization of impacted maxillary canines by panoramic radiographs

OBJECTIVES

The objective of this study was to compare three methods for localization of impacted maxillary canines using only conventional panoramic radiographs.

METHODS

The panoramic radiographs of 94 patients (102 impacted maxillary canines) were reviewed and evaluated using the methods magnification, angulation and superimposition. The actual positions of them were decided with cone beam CT images. The predicted positions of impacted canines from the magnification and angulation methods were compared using the McNemar χ(2) test. Sensitivity, specificity, accuracy, positive-likelihood ratio and negative-likelihood ratio were calculated. The canine-incisor index values and α angles of palatally and bucally non-rotated impacted canines were compared using the Mann-Whitney U test.

RESULTS

The statistical analysis revealed that there was a significant difference between the magnification and angulation methods (p < 0.01). Using the magnification method, 68.00% of buccal canines and 69.57% of palatal canines could be localized correctly. The results of the angulation method were 28.57% and 84.91%, respectively. The sensitivity of the angulation method for buccal canines was very low. In the superimposition method, 82.98% of the superimposing samples were palatal.

CONCLUSIONS

The magnification and angulation methods were not reliable methods for locating the impacted canine with a single panoramic radiograph. Magnification was more successful than the angulation method. Further research is needed on the magnification method. The image superimposition method could be used as an adjunct to others.

Plasma-assisted heparin conjugation on electrospun poly(L-lactide) fibrous scaffolds

Heparin conjugation on poly(L-lactide) fibrous scaffolds fabricated by electrospinning was accomplished by surface functionalization with amine (-NH2) groups using a sequential treatment with Ar-NH3 and H2 plasmas. The density of the incorporated -NH2 groups was determined by combining a chemical derivatization method with X-ray photoelectron spectroscopy. The time of Ar-NH3 plasma treatment significantly affected the N/C, -NH2 /N, and -NH2 /C fractions, whereas the plasma power, Ar-NH3 gas composition, and time of H2 plasma treatment only influenced the -NH2 /N and -NH2 /C fractions. Scaffold surface functionalization by -NH2 groups significantly increased the amount of covalently bonded heparin compared to a hydrolysis method. The function of immobilized heparin was confirmed by the decrease of platelet attachment during the exposure of the scaffolds to blood from Sprague-Dawley rats. In vitro experiments with bovine aorta endothelial cells demonstrated that heparin conjugation enhanced cell infiltration through the fibrous scaffolds, regardless of the amount of covalently immobilized heparin.

Immunomodulatory properties of dental tissue-derived mesenchymal stem cells

In addition to their well-established self-renewal and multipotent differentiation properties, mesenchymal stem cells (MSCs) also possess potent immunomodulatory functions both in vitro and in vivo, which render them a potential novel immunotherapeutic tool for a variety of autoimmune and inflammation-related diseases. The major mechanisms may involve (1) the secretion of an array of soluble factors such as prostaglandin E2 (PGE2 ), indoleamine 2, 3-dioxygenase (IDO), transforming growth factor-β (TGF-β), and human leukocyte antigen G5 (HLA-G5); (2) interactions between MSCs and immune cells such as T cells, B cells, macrophages, and dendritic cells. Recently, increasing evidence has supported that MSCs derived from dental tissues are promising alternative sources of multipotent MSCs. We here provide a thorough and extensive review about new findings in the immunomodulatory functions of MSCs derived from several dental tissues, including dental pulp, periodontal ligament, gingiva, exfoliated deciduous teeth, apical papilla, and dental follicle, respectively. The immunomodulatory properties of dental MSCs place them as a more accessible cell source than bone marrow-derived MSCs for cell-based therapy of immune and inflammation-related diseases.

Modulation of hypovitaminosis D-induced islet dysfunction and insulin resistance through direct suppression of the pancreatic islet renin-angiotensin system in mice

AIMS/HYPOTHESIS

Vitamin D is necessary for normal insulin action and suppresses renin production. Increased renin-angiotensin system (RAS) activity causes islet damage, including reduced insulin secretion. We therefore sought to determine whether hypovitaminosis D-induced upregulation of islet RAS in vivo impairs islet cell function and increases insulin resistance, and whether pharmacological suppression of the RAS during continuing vitamin D deficiency might correct this.

METHODS

C57BL/6 mice were rendered vitamin D-deficient by diet, and glucose and insulin tolerance was assessed. The expression and translation of islet functional, and islet RAS, genes were measured and the effects of pharmacological renin suppression examined.

RESULTS

Mice with diet-induced hypovitaminosis D developed impaired glucose tolerance, increased RAS component expression and impaired islet function gene transcription. Treatment with pharmacological renin inhibition (aliskiren), without vitamin D status correction, reduced islet RAS over-reactivity, islet dysfunction and insulin resistance, and improved glucose tolerance.

CONCLUSIONS/INTERPRETATION

Upregulation of islet RAS genes can contribute to hypovitaminosis D-induced impairment of islet function and increase insulin resistance independently of vitamin D status. Thus, our findings support the use of RAS inhibitors in impaired glucose homeostasis or early diabetes. They also suggest that combining RAS inhibition with correction of hypovitaminosis D might be useful in treating impaired glycaemic control and also in type 2 diabetes prevention. However, the use of aliskiren in established diabetes is contraindicated due to the increased risk of side effects such as hyperkalaemia, so other more suitable RAS blockers need to be identified.

Downregulation of Mcl-1 through inhibition of translation contributes to benzyl isothiocyanate-induced cell cycle arrest and apoptosis in human leukemia cells

Benzyl isothiocyanate (BITC) is one of the compounds of ITCs' family that has attracted a great deal of interest because of its ability to exhibit anticancer activity. In this study, we investigated the effects of BITC on cell cycle arrest and apoptosis in human leukemia cell lines, primary leukemia cells, and nude mice Jurkat xenograft. Exposure of Jurkat cells to BITC resulted in dose- and time-dependent increase in apoptosis, caspase activation, cytochrome c release, nuclear apoptosis-inducing factor (AIF) accumulation, Bcl2-associated X protein (Bax) translocation, and myeloid cell leukemia-1 (Mcl-1) downregulation. Treatment with these cells also resulted in cell cycle arrest at the G2/M phase. The G2/M-arrested cells are more sensitive to undergoing Mcl-1 downregulation and apoptosis mediated by BITC. BITC downregulates Mcl-1 expression through inhibition of translation, rather than through a transcriptional, post-translational, or caspase-dependent mechanism. Dephosphorylation of eukaryotic initiation factor 4G could contribute to the inhibition of Mcl-1 translation mediated by BITC. Furthermore, ectopic expression of Mcl-1 substantially attenuates BITC-mediated lethality in these cells, whereas knockdown of Mcl-1 through small interfering RNA significantly enhances BITC-mediated lethality. Finally, administration of BITC markedly inhibited tumor growth and induced apoptosis in Jurkat xenograft model in association with the downregulation of Mcl-1. Taken together, these findings represent a novel mechanism by which agents targeting Mcl-1 potentiate BITC lethality in transformed and primary human leukemia cells and inhibitory activity of tumor growth of Jurkat xenograft model.