Quantification of conidial density of Aspergillus flavus and A. parasiticus in soil from almond orchards using real-time PCR

AIMS

To design the Aspergillus flavus and Aspergillus parasiticus-specific primers and a real-time PCR assay for quantification of the conidial density in soil.

METHODS AND RESULTS

Aspergillus flavus and A. parasiticus-specific DNA primers were designed based on internal transcribed spacer sequences to distinguish these two species and from other Aspergillus and other fungal species. A method of pathogen DNA extraction directly from soil samples was developed. Using the designed primers, a real-time PCR assay was developed to quantitatively determine the conidial density of each A. flavus and A. parasiticus in soil, after generating corresponding standard curves. Known conidial densities of each A. flavus or A. parasiticus in soil significantly correlated with those tested with the real-time PCR.

CONCLUSIONS

This study demonstrated the applicability of the real-time PCR assay in studies of quantifying A. flavus and A. parasiticus in soil as inoculum sources.

SIGNIFICANCE AND IMPACT OF THE STUDY

The A. flacus and A. parasitic-specific primers can be widely used in aflatoxin research. The real-time PCR assay developed in this study provides a potential approach to quantify the plant pathogen density from not only soil but also other sources in relation to aflatoxin contamination from environment, food and feed commodities.

Reg IV expression is associated with cell growth and prognosis of adenoid cystic carcinoma in the salivary gland

AIMS

Regenerating islet-derived family, member 4 (Reg IV) is associated with the progression of various cancers. The aim was to examine Reg IV expression in adenoid cystic carcinomas (ACCs) in salivary glands.

METHODS AND RESULTS

Reg IV expression was detected by immunohistochemistry and compared with clinicopathological parameters. Expression of phosphorylated epidermal growth factor receptor (pEGFR), phosphorylated AKT (pAKT) and MUC2 was examined by immunohistochemistry. Reg IV function was assessed with Reg IV antisense S-oligodeoxynucleotides (AS) in ACC3 human ACC cells. Reg IV was expressed by salivary duct epithelia and acinus myoepithelia, but not in squamous epithelia. Reg IV expression was found in 41% (17/41) of ACCs, but in none of 40 oral squamous cell carcinomas (OSCCs) and was associated with nodal metastasis (P = 0.047) and poor prognosis (P = 0.012) in ACCs. Reg IV expression was associated with pEGFR (14/17, 82%) in Reg IV+ ACCs, but had no relationship with pAKT or MUC2 expression in ACCs. Cell growth was inhibited by AS treatment in Reg IV+ ACC3 cells, but not in HSC-4 OSCC cells, whereas in vitro invasion of neither cell types was affected by AS treatment.

CONCLUSIONS

These results suggest that Reg IV might accelerate cell growth and disease progression of ACCs.

Desorption and ripening of low density InAs quantum dots

In this paper, combining low deposition rate with proper growth temperature, we have developed a way to prepare very low-density quantum dots (QDs) suited for the study of single QD properties without resorting to submicron lithography. Experiment results demonstrate that InAs desorption is significant during growing the low density QDs. Ripening of InAs QDs is clearly observed during the post-growth annealing. Photoluminescence spectroscopy reveals that the emission wavelength of low density InAs QDs arrives at 1332.4 nm with a GaAs capping layer.

Identification of site(s) of insulin nitration by peroxynitrite and characterization of its structural change

Insulin nitration mediated by peroxynitrite (ONOO(-)) has been implicated in diabetes and diabetic cardiovascular complications. In this study, we identified the nitration sites of porcine insulin by infusion of ONOO(-) and quantified its secondary structural change. Insulin was cleaved with V8 protease to six peptides (four of them contained each tyrosine residue), then analyzed by HPLC-MS and further confirmed the nitration sites by HPLC-MS/MS. At low accumulated doses of peroxynitrite, the main products were two different mono-nitrated insulin species at Tyr-A19 and Tyr-B26 with Tyr-A19 being predominant as shown by peptide mapping. Also, the content of alpha-helix structure of insulin reduced to 22.9 % and random-coil structure increased to 30.2 % (compare with native insulin of 41.7 % and 13.7 %, respectively) as determined by FTIR spectra.

Sensorless control for a sophisticated artificial myocardial contraction by using shape memory alloy fibre

The authors have been developing an artificial myocardium, which is capable of supporting natural contractile function from the outside of the ventricle. The system was originally designed by using sophisticated covalent shape memory alloy fibres, and the surface did not implicate blood compatibility. The purpose of our study on the development of artificial myocardium was to achieve the assistance of myocardial functional reproduction by the integrative small mechanical elements without sensors, so that the effective circulatory support could be accomplished. In this study, the authors fabricated the prototype artificial myocardial assist unit composed of the sophisticated shape memory alloy fibre (Biometal), the diameter of which was 100 microns, and examined the mechanical response by using pulse width modulation (PWM) control method in each unit. Prior to the evaluation of dynamic characteristics, the relationship between strain and electric resistance and also the initial response of each unit were obtained. The component for the PWM control was designed in order to regulate the myocardial contractile function, which consisted of an originally-designed RISC microcomputer with the input of displacement, and its output signal was controlled by pulse wave modulation method. As a result, the optimal PWM parameters were confirmed and the fibrous displacement was successfully regulated under the different heat transfer conditions simulating internal body temperature as well as bias tensile loading. Then it was indicated that this control theory might be applied for more sophisticated ventricular passive or active restraint by the artificial myocardium on physiological demand.

Hematopoietic stem cell transplantation in patients with sporadic amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS), an inexorably progressive motoneuron disease, is accompanied by significantly increased markers of inflammation. These inflammatory constituents could protect, harm, do neither, or do both.

OBJECTIVE

Allogeneic hematopoietic stem cell transplantation (HSCT) was performed in patients with sporadic ALS to suppress neuroinflammation and improve clinical outcomes after CNS engraftment.

METHODS

Six patients with definite ALS received total body irradiation followed by peripheral blood HSCT infusion from human leukocyte antigen identically matched sibling donors. Disease progression and survival were assessed monthly and compared with matched historic database patients. Autopsy samples from brain and spinal cord were examined immunohistochemically and by quantitative reverse-transcriptase polymerase chain reaction. Donor-derived DNA in brain and spinal cord tissue was evaluated for the extent of chimerism.

RESULTS

No clinical benefits were evident. Four patients were 100% engrafted; postmortem tissue examination in two of the 100% engrafted patients demonstrated 16% to 38% donor-derived DNA at sites with motoneuron pathology, which may correspond to the observed increased CD68 or CD1a-positive cells. Neither donor DNA nor increased cell numbers were found in several unaffected brain regions. A third minimally engrafted patient had neither donor DNA nor increased infiltrating cells in the CNS.

CONCLUSIONS

This study demonstrates that peripheral cells derived from donor hematopoietic stem cells can enter the human CNS primarily at sites of motoneuron pathology and engraft as immunomodulatory cells. Although unmodified hematopoietic stem cells did not benefit these sporadic amyotrophic lateral sclerosis patients, such cells may provide a cellular vehicle for future CNS gene therapy.

Anti-angiogenesis therapy based on the bone marrow-derived stromal cells genetically engineered to express sFlt-1 in mouse tumor model

Background

Bone marrow-derived stromal cells (BMSCs) are important for development, tissue cell replenishment, and wound healing in physiological and pathological conditions. BMSCs were found to preferably reach sites undergoing the process of cell proliferation, such as wound and tumor, suggesting that BMSCs may be used as a vehicle for gene therapy of tumor.

Methods

Mouse BMSCs were loaded with recombinant adenoviruses which express soluble Vascular Endothelial Growth Factor Receptor-1 (sFlt-1). The anti-angiogenesis of sFlt-1 in BMSCs was determined using endothelial cells proliferation inhibition assay and alginate encapsulation assay. The anti-tumor effects of BMSCs expressing sFlt-1 through tail-vein infusion were evaluated in two mouse tumor metastases models.

Results

BMSCs genetically modified with Adv-GFP-sFlt-1 could effectively express and secret sFlt-1. BMSCs loaded with sFlt-1 gene could preferentially home to tumor loci and decrease lung metastases and prolong lifespan in mouse tumor model through inducing anti-angiogenesis and apoptosis in tumors.

Conclusion

We demonstrated that BMSCs might be employed as a promising vehicle for tumor gene therapy which can effectively not only improve the concentration of anticancer therapeutics in tumors, but also modify the tumor microenvironment.

A new fast-ion D(alpha) diagnostic for DIII-D

The fast-ion D(alpha) (FIDA) technique is a charge-exchange recombination spectroscopy measurement that exploits the large Doppler shift of Balmer-alpha light from energetic hydrogenic atoms to infer the fast-ion density. Operational experience with the first dedicated FIDA diagnostic on DIII-D is guiding the design of the second-generation instrument. In the first instrument, dynamic changes in background light associated with plasma instabilities usually dominate measurement uncertainties. Accordingly, the design of the new instrument minimizes scattering of cold D(alpha) light while monitoring its level. The first instrument uses a vertical view to avoid bright interference from the injected-neutral beams. The sightline of the new instrument includes a toroidal component but only measures blueshifted fast-ion light that is Doppler shifted away from the redshifted light of the injected neutrals. The new views are more sensitive to fast ions that circulate in the direction of the plasma current and less sensitive to the trapped-ion and countercirculating populations. Details of the design criteria and solutions are presented.

Oral health and its impact on the life quality of homeless people in Hong Kong

OBJECTIVES

To report on the oral health status and its impact on the life quality of homeless people in Hong Kong.

DESIGN

A cross sectional epidemiological survey involving clinical oral examinations and face-to-face interviews with 147 homeless participants. Clinical examinations were carried out following WHO criteria. The impact of oral health on quality of life was assessed with the short form of Oral Health Impact Profile, OHIP-14.

RESULTS

Over 90% had caries experience and most related to untreated decay. The mean DMFT score for dentate subjects was 8.1 (DT = 3.4, MT = 4.0, FT = 0.7). Periodontal disease was highly prevalent, 96% having periodontal pockets. The burden of oral health on their daily lives was common, 88% reporting an oral health impact within the past year. A multiple regression analysis indicated that the OHIP-14 score had significant associations with self-rated oral health, dental pain, employment status and length of time being homeless (p < 0.05). Those who assessed rated oral health as 'poor/very poor', reported dental pain in the past year, were unemployed, and homeless for more than one year had poorer oral health related quality of life (significantly higher OHIP scores) than their counterparts.

CONCLUSION

Among the homeless population studied, oral health status was poor and its impact on their life quality was substantial. The oral health impact was associated with socio-demographics and perceived dental problems.

Event-related potentials study on cross-modal discrimination of Chinese characters

Event-related potentials (ERPs) were measured in 15 normal young subjects (18-22 years old) using the "cross-modal and delayed response" paradigm, which is able to improve inattention purity. The stimuli consisted of written and spoken single Chinese characters. The presentation probability of standard stimuli was 82.5% and that of deviant stimuli was 17.5%. The attention components were obtained by subtracting the ERPs of inattention condition from those of attention condition. The results of the N1 scalp distribution demonstrated a cross-modal difference. This result is in contrast to studies with non-verbal as well as with English verbal stimuli. This probably reflected the brain mechanism feature of Chinese language processing. The processing location of attention was varied along with verbal/ non-verbal stimuli, auditory/visual modalities and standard/deviant stimuli, and thus it has plasticity. The early attention effects occurred before the exogenous components, and thus provided evidence supporting the early selective theory of attention. According to the relationship of N1 and Nd1, the present result supported the viewpoint that the N1 enhancement was caused by endogenous components overlapping with exogenous one rather than by pure exogenous component.

Isolation of mouse neutrophils

Neutrophils are widely used in research to elucidate the mechanisms of inflammation, including such processes as cell adhesion, chemotaxis, superoxide release, production of reactive nitrogen intermediates, and granule exocytosis. This unit presents a protocol for the induction of an enriched exudate of polymorphonuclear leukocytes (PMN) in the peritoneal cavity of mice. Neutrophils are then isolated using continuous gradient centrifugation. This is followed by a protocol for isolating neutrophils from peripheral blood. An alternate method for the purification of PMN from peritoneal exudate cells or peripheral blood by Histopaque density gradient centrifugation is also provided. The cell purification protocol can be modified to obtain nonelicited neutrophils from peritoneal fluid.

Delayed-type hypersensitivity

Delayed-type hypersensitivity (DTH) is an in vivo assay of cell-mediated immune function. DTH reactions are often divided into two phases: the sensitization phase, referring to the initial immunization with specific antigen, and the efferent or challenge phase of the DTH response, which usually follows 6 to 14 days after sensitization. This unit details the protocol for stimulating DTH responses in mice to the O-succinimide ester of the hapten 4-hydroxy-3-nitrophenyl acetyl (abbreviated NP-O-Su).

Haemolytic Uraemic Syndrome after Living-donor Liver Transplantation: Is Small-for-size Graft a Potential Risk Factor?

Haemolytic uraemic syndrome (HUS) is a rare complication of solid organ transplantation. Immunosuppressive drugs, including cyclosporin A and tacrolimus, have frequently been incriminated. Here we report a case of tacrolimus-induced HUS in a woman with small-for-size syndrome after living-donor liver transplantation. Hypertension, microangiopathic anaemia and end-stage renal failure occurred in the immediate post-transplant period; all other risk factors that might be implicated in the development of HUS were investigated and excluded if no evidence was found. A possible association between small-for-size syndrome, which frequently results in a high blood concentration of tacrolimus post-operatively, and the occurrence of HUS is discussed.

Enhancement characteristics of benign and malignant focal peripheral nodules in the peripheral zone of the prostate gland studied using contrast-enhanced transrectal ultrasound

AIM

To assess the value of contrast-enhanced grey-scale transrectal ultrasound (CETRUS) in predicting the nature of peripheral zone hypoechoic lesions of the prostate.

MATERIALS AND METHODS

Ninety-one patients with peripheral zone hypoechoic lesions on ultrasound were evaluated with CETRUS followed by lesion-specific and sextant transrectal ultrasound-guided biopsies. The enhancement patterns of the lesions were observed and graded subjectively using adjacent peripheral zone tissue as the reference. Time to enhancement (AT), time to peak intensity (TTP) and peak intensity (PI) were quantified within each nodule. Ultrasound findings were correlated with biopsy findings.

RESULTS

Transrectal ultrasound-guided biopsy of the hypoechoic lesions revealed prostate cancer in 44 patients and benign prostatic diseases in 47. The intensity of enhancement within the lesions were graded as no enhancement, increased, equal, or decreased compared with adjacent peripheral zone tissue in two, 30, five and seven in the prostate cancer group and 14, 15, four and 14 in the benign group, respectively. The difference was statistically significant (p<0.05). The peak enhancement intensity was found to be the most optimal discriminatory parameter (area under curve AUC 0.70; 95% CI: 0.58, 0.82).

CONCLUSION

Malignant hypoechoic nodules in the peripheral zone of the prostate are more likely to enhance early and more intensely on CETRUS. A non-enhanced hypoechoic peripheral zone lesion was more likely to be benign.

Analysis of the pathomorphology of the intra- and extrahepatic biliary system in biliary atresia

OBJECTIVE

Aim of the study was to investigate the pathomorphological changes in the liver and triangular cord of the porta hepatis in biliary atresia and assess the relationship between the degree of differentiation of fibroblasts in the triangular cord of the porta hepatis and the liver fibrosis scores.

METHODS

From September 2005 to May 2006, 21 patients with biliary atresia (66+/-20 days old) underwent a Kasai procedure. The liver biopsy and the remnant of the porta hepatis were conserved. Five cases with cholestasis syndrome and 10 cases with choledochal cyst were used as a control group. Liver biopsies were performed in the control group. The micro- and ultrastructure of the liver and the remnant of the porta hepatis were assessed in the biliary atresia and the control group. Ultrastructural features were examined by transmission electron microscopy. The semiquantitative differences in liver fibrosis grading between the biliary atresia and the control group was evaluated with a 3-grade staging system. The degree of differentiation of fibroblasts (FB) in the triangular cord of the porta hepatis was assessed as follows: 1) juvenile type: above 50 % FBs were juvenile, 2) senior type: above 50% FBs were senior, 3) median type: between the former 2 types. The differentiation scores of FB in the porta hepatis were assessed in relation to the liver fibrosis score.

RESULTS

1) The pathological changes with BA are characterized by inflammation and fibrosis in the hepatic portal area. The fibrosis scores in the biliary atresia group (I: 2 cases, II: 12 cases, III: 7 cases) were significantly higher than in the control group (I: 8 cases, II: 5 cases, III: 2 cases; p=0.01. 2) In the biliary atresia group, the extrahepatic biliary system of all cases showed a triangular cord in the porta hepatis. The triangular cord of porta hepatis was characterized by hyperplasia of canaliculi, atresia or stenosis of the bile ducts, inflammation infiltration, cholestasis, and interstitial fibrosis. 3) The ultrastructural features of BA showed active fibroblasts, a loss of microvilli, dense deposits in the hepatocytes and liver sinusoid, and dilatation of canaliculi. 4) The differentiation scores of FB in the porta hepatis were positively related to the liver fibrosis score (p=0.04).

CONCLUSION

The main pathological changes of biliary atresia are inflammation and fibrosis in the hepatic portal area. The ultrastructural features of biliary atresia suggested that the differentiation scores of FB in the triangular cord of the porta hepatis were positively related to the liver fibrosis score.

Co-inheritance of a PKD1 mutation and homozygous PKD2 variant: a potential modifier in autosomal dominant polycystic kidney disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD), which is caused by mutations in polycystins 1 (PC1) and 2 (PC2), is one of the most commonly inherited renal diseases, affecting ~1 : 1000 Caucasians.

MATERIALS AND METHODS

We screened Greek ADPKD patients with the denaturing gradient gel electrophoresis (DGGE) assay and direct sequencing.

RESULTS

We identified a patient homozygous for a nucleotide change c.1445T > G, resulting in a novel homozygous substitution of the non-polar hydrophobic phenylalanine to the polar hydrophilic cysteine in exon 6 at codon 482 (p.F482C) of the PKD2 gene and a de-novo PKD1 splice-site variant IVS21-2delAG. We did not find this PKD2 variant in a screen of 280 chromosomes of healthy subjects, supporting its pathogenicity. The proband's parents did not have the PKD1 mutation. Real-time PCR of the PKD2 transcript from a skin biopsy revealed 20-fold higher expression in the patient than in a healthy subject and was higher in the patient's peripheral blood mononuclear cells (PBMCs) than in those of her heterozygote daughter and a healthy subject. The greater gene expression was also supported by Western blotting. Inner medullar collecting duct (IMCD) cells transfected with the mutant PKD2 mouse gene presented a perinuclear and diffuse cytoplasmic localization compared with the wild type ER localization. Patch-clamping of PBMCs from the p.F482C homozygous and heterozygous subjects revealed lower polycystin-2 channel function than in controls.

CONCLUSIONS

We report for the first time a patient with ADPKD who is heterozygous for a de novo PKD1 variant and homozygous for a novel PKD2 mutation.

Pollination of Cypripedium plectrochilum (Orchidaceae) by Lasioglossum spp. (Halictidae): the roles of generalist attractants versus restrictive floral architecture

The pollination of Cypripedium plectrochilum Franch. was studied in the Huanglong Nature Reserve, Sichuan, China. Although large bees (Bombus, Apis), small bees (Ceratina, Lasioglossum), ants (Formica sp.), true flies (Diptera) and a butterfly were all found to visit the flowers, only small bees, including three Lasioglossum spp. (L. viridiclaucum, L. sichuanense and L. sp.; Halictidae) and one Ceratina sp., carried the flower's pollen and contacted the receptive stigma. Measurements of floral architecture showed that interior floral dimensions best fit the exterior dimensions of Lasioglossum spp., leading to the consistent deposition and stigmatic reception of dorsally-placed, pollen smears. The floral fragrance was dominated by one ketone, 3-methyl-Decen-2-one. The conversion rate of flowers into capsules in open (insect) pollinated flowers at the site was more than 38%. We conclude that, while pigmentation patterns and floral fragrance attracted a wide variety of insect foragers, canalization of interior floral dimensions ultimately determined the spectrum of potential pollinators in this generalist, food-mimic flower. A review of the literature showed that the specialised mode of pollination-by-deceit in C. plectrochilum, limiting pollinators to a narrow and closely related guild of 'dupes' is typical for other members of this genus.

Effects of mild heat treatment on microbial growth and product quality of packaged fresh-cut table grapes

The changes in packaged fresh-cut grape quality and microbial growth as affected by mild heat treatments and the retention of grape cap stems during 5 degrees C storage were evaluated. Each individual grape was either manually pulled off (stemless) from the stems, or cut (cut stem) to allow for a 1- to 2-mm cap stem remaining on the berry. The samples were sanitized in 100 mg/L chlorine solution for 1 min, followed by a mild heat treatment in a water bath (45 degrees C, 8 min) or an oven (55 degrees C, 5 min). After cooling, the berries were packaged in rigid trays sealed with a gas permeable film and stored at 5 degrees C. Product quality and decay rate were evaluated periodically during storage. The results indicate that in the package headspace for hot water treatment of stemless grapes, partial pressures of O(2) declined significantly (P < 0.05) less and C(2)H(4) increased significantly (P < 0.001) less than for the control and hot air treatment. Stem removal and heat treatment had significant (P < 0.05) effects on the decay rate of grapes during storage. Hot water treatment maintained a significantly lower decay rate than the control and hot air treatment throughout the entire storage. Color and texture were not significantly (P > 0.05) affected by either heat treatment or stem removal. Grapes that retained the cap stems and received hot water treatment had the lowest decay rate and lowest microbial growth with the absence of any negative impact on grape color, texture, and flavor.