Hepatitis E virus infection among domestic animals in eastern China

Hepatitis E virus (HEV) is a zoonotic pathogen of which several species of animal were reported as reservoirs. Antibodies to HEV and HEV RNA have been detected in some Chinese population and swine groups but few other domestic animals. In this study, to investigate the HEV prevalence, we tested sera from 788 pigs, 100 cows, 50 goats, 49 horses, 101 pet dogs, 105 chickens, 47 duck and 45 pigeons in eastern China for anti-HEV immunoglobulin G (IgG). We also tested 50% of the swine sera, all of sera from the other domestic animals and 13 Shanghai human sera which were positive for anti-HEV immunoglobulin M (IgM) for HEV RNA using reverse transcriptase-polymerase chain reaction. Our results indicated that 82.5% (222/269) of the sows, 53.9% (104/193) of the 4- to 6-month-old swine, 63.4% (168/265) of the 1- to 3-month-old swine, 55.7% (34/61) of the slaughterhouse swine, 24% (12/50) of the goats, 16.3% (8/49) of the horses, 17.8% (21/101) of the pet dogs, 6% (6/100) of the cows, 12.8% (6/47) of the ducks, 4.4% (2/45) of the pigeons and 1.9% (2/105) of the chickens exhibited positive for anti-HEV IgG. Inhibition assay confirmed the infection with HEV or HEV-like viruses in these domestic animals except pigeons and chickens. From the sera, we isolated 18 swine HEV strains, one horse HEV strain and two human HEV strains. Sequence analysis showed that the horse HEV isolate and one swine isolate belonged to genotype 3. The other isolates belonged to genotype 4. The two human isolates were phylogenetically closely related to eight of the swine isolates. In short, the presence of anti-HEV antibody had been confirmed in several species of domestic animals in eastern China and HEV RNA has been identified in swine, human and horse. This suggested that the authorities should pay more attention to the prevalence of HEV in eastern China.

Performance and mechanism of methylene blue biosorption on orange peel

Biosorption of Methylene Blue (MB) from aqueous solution using orange peel biosorbent was experimentally investigated. The effects of dye concentration, solution pH, salt concentration and contact time were investigated in a batch model. The results showed that adsorption equilibrium was reached within one hour at two initial MB concentrations (200 and 1000 mg 1(-1)). The uptake of MB was significantly affected by the pH of dye solution. As the pH decreased, the uptake of MB decreased and was zero at pH 2. The Langmuir isotherm model fitted the experimental data well, and the maximum adsorption capacities of the orange peel were 246.8 +/- 10.6 and 370.3 +/- 31.0 mg g(-1) at pH 7 and pH 10, respectively. The uptake of MB was significantly affected by the high concentration of salts. Adsorption of MB onto orange peel was reversible, and the sorption/desorption efficiencies remained almost 100% even up to seven reuse cycles when the biosorbent loss was taken into consideration. The binding sites were identified to be primary carboxyl groups present in orange peel. The main mechanism of MB adsorption is considered to be electrostatic interaction.

Over-expression of S100A2 in pancreatic cancer correlates with progression and poor prognosis

Controversy exists regarding the clinical significance of S100A2 in the progression of tumours. In pancreatic cancer, little is known about the role of S100A2. The aim of this study was to clarify the clinical significance of S100A2 expression in pancreatic carcinogenesis. We microdissected invasive ductal carcinoma (IDC) cells from 22 lesions, pancreatic intraepithelial neoplasia (PanIN) cells from five lesions, intraductal papillary mucinous neoplasm (IPMN) cells from 38 lesions, pancreatitis-affected epithelial (PAE) cells from 16 lesions, and normal ductal cells from 18 normal pancreatic tissues. S100A2 expression in 14 pancreatic cancer cell lines, microdissected cells and formalin-fixed paraffin-embedded (FFPE) samples was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Microdissection analyses revealed that IDC cells expressed higher levels of S100A2 than did IPMN, PAE or normal cells (all comparisons, p < 0.007). Cell lines from metastatic sites expressed higher levels of S100A2 than those from primary sites. PanIN cells expressed higher levels of S100A2 than normal cells (p = 0.018). IDC cells associated with poorly differentiated adenocarcinoma expressed higher levels of S100A2 than did IDC cells without poorly differentiated adenocarcinoma (p = 0.006). Analyses of FFPE samples revealed that levels of S100A2 were higher in samples from patients who survived < 1000 days after surgery than in those from patients who survived > 1000 days (p = 0.043). Immunohistochemical analysis was consistent with qRT-PCR. S100A2 may be a marker of tumour progression or prognosis in pancreatic carcinogenesis and pancreatic cancer.

Fatty acid-dependent expression of the muscle FABP gene - comparative analysis of gene control in functionally related, but evolutionary distant animal systems

The heart is the most fatty acid-dependent muscle in mammals, but flight muscles of birds and insects encounter even higher rates of fatty acid oxidation. The amount of the muscle fatty acid binding protein (H-FABP) found in these muscle reflects their metabolic activities, and increased fatty acid metabolism in endurance exercise increases FABP expression further. We have studied the mechanism of fatty acid-dependent expression of the H-FABP gene, taking advantage of the comparative analysis of gene control in functionally related, but evolutionary distant animal systems, i.e., rat heart and locust flight muscle. Luciferase reporter genes with a full-length promoter ( approximately 1 kb) from either the locust or the rat were strongly expressed in L6 myoblasts, and the expression of both constructs was markedly increased by fatty acid treatment. Because of its stronger induction by fatty acids and the absence of other vertebrate transcription factor binding sites, the locust promoter was advantageous for the identification of a fatty acid response element (FARE), an inverted repeat of a hexanucleotide half site reminiscent of steroid hormone receptor binding sites (IR-3). All mammalian H-FABP promoters contain similar sequences, however in reverse orientation (everted repeats, ER-3). Deletion of the FARE eliminated the fatty acid inducibility completely for the locust promoter, but only partly for its mammalian analogue, perhaps because of additional factors or more complex interactions. In gel shift studies, the element binds nuclear proteins from both rat cells and locust flight muscle, further attesting to the far-reaching conservation of this mechanism. Two individual proteins bind to the element, with full binding requiring the presence of free fatty acid. Antibodies to PPARs failed to induce a supershift of the protein-DNA complex, indicating that other transcription factors are responsible for the fatty acid-mediated induction of gene expression of H-FABP.

Tissue Engineering and Tissue Repair in Immunocompetent Animals: Tissue Construction and Repair

Tissue engineering can regenerate autologous tissue using a biodegradable scaffold and in vitro expanded cells derived from small biopsy samples, and thus may have great potential for tissue repair and reconstruction in plastic and reconstructive surgery. As an important step towards a clinical application, research work in large animals is essential. This article presents our experience of tissue engineering and repair in large animals in the areas of bone, cartilage and tendon.

An alkaline protease from fresh fruiting bodies of the edible mushroom Pleurotus citrinopileatus

A protease was purified from fresh fruiting bodies of the edible mushroom Pleurotus citrinopileatus. The isolation procedure included ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose and fast protein liquid chromatography-gel filtration on Superdex 75. The protease was unadsorbed on DEAE-cellulose and Q-Sepharose, but adsorbed on CM-cellulose. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the protease demonstrated a single band with a molecular mass of 28 kDa. The protease showed an optimal pH at 10 and an optimal temperature at 50 degrees C. The activity of the protease was not affected by EDTA, indicating that it is not a metalloprotease. The protease exhibited a higher activity in the presence of K(+) and Li(+), but its activity was potently inhibited by Al(3+), Cu(2+), and Hg(2+) ions. It manifested a K (m) of 3.44 mg/ml and a V (max) of 0.139 mg ml(-1) min(-1). It was devoid of ribonuclease and antifungal activities.

Effect of an Immunosuppressor (Dexamethasone) on Eperythrozoon Infection

The aim was to study the relationship between the infection rate of Eperythrozoon suis and the status of the immune system. Four pigs with chronic eperythrozoonosis were divided into experimental and control groups. Immunosuppression of the experimental group was accomplished by injecting with high-dose glucocorticoid (dexamethasone) on 3 consecutive days. Microscopic examination of blood smears was performed to observe the change of infection rate after administration. The blood samples of each group were collected on day 7 after administration for half-nested PCR assay. The microscopic results showed that the infection rate of the experimental group rose distinctly by 40 h late and remained at 90% in the days following administration. No changes were observed in the control group. PCR results showed a single expected 250 bp fragment in each group, which validated the positive microscopic results. This study demonstrated the significant effect of dexamethasone (DEX) on Eperythrozoon infection.

The cryopreservation of a tissue engineered dermal replacement by programmed freezing

Long-term storag of engineered bio-artificial tissues is required to ensure the off-the-shelf availability to clinicians due to their long production cycle. Cryopreservation is likely the choice for long-term preservation. This study investigated the effects of dimethyl sulfoxide (DMSO) concentrations, cooling rates, cryoprotectant medium treatment methods and seeding on the cell viability of a tissue-engineered dermal substitute. The dermal fibroblast was cultured on a polyglycolic acid (PGA) scaffolding at 37degree C and a 5% CO<inf>2</inf>atmosphere for 14 days, and dermal slices (10&#215;3&#215;1.5mm) were used in the experimental group. The freezing was carried out in a computer-controlled programmable freezer at 0.5degree C/min, 1degree C/min and 2degree C/min in1.4M, 2.1M and 2.8M DMSO from 4degree C to -60degree C and then plunged into the liquid nitrogen tank immediately. After 24th of cryopreservation, the samples wereped in removed from liquid nitrogen and placed at room temperature in air for 0.5-1min, prior to submergence in a water bath at 37 degree C. viability of fresh control and cryopreserved dermal slices were determined with our modification of the MTT (3-[4,5-Dimethythiazol-2-yl] -2,5-diphenyltetrazolium bromide) assay. The effects of two cryoprotectant medium treatment methods and seeding (at -7degree C)on cell viability were also assessed. A cryopreservation protocol of 1degree C/min in 1.4M DMSO from 4degree C to -60degree C, and seeding at -7degree C proved optimal for this tissue-engineered dermal replacement, provided the dermal slice was transferred into the cryopreservation bag containing 1mL 1.4M DMSO bag and hold for 15min at 4degree C prior to freezing.

368 FIELD STUDIES ON THE EFFECTIVENESS OF THE YCD EMBRYO SEXING TECHNIQUE IN BOVINE

The YCD sexing technique is applied in many commercial breeding programs due to its ease of operation in the field and its reliable and accurate sex determination results. Less equipment requirements and more simplified protocols provide great convenience for field applications of this method, and processing errors and chances of assay contamination are reduced. To increase the effectiveness of this technique in future field applications, field data collected from commercial embryo transfer programs in 63 farms in China during June 2002 to December 2005 were analyzed. Embryos were flushed from superovulated dairy cattle and subjected to a biopsy for sex determination using protocols and YCD sexing kits supplied by AB Technology Ltd. (Pullman, WA, USA). Embryos were implanted fresh on the same day or frozen with AG freeze medium (AB Technology Ltd.) for later transfer. The chi-square test was used for statistic analysis. This study indicates that sampling with a piece of zona pellucida (ZP) during embryo sexing increased the incidence of no response (NR) but did not alter the accuracy of determining sex of offspring. Larger biopsies significantly reduced the incidence of NR after DNA amplification and electrophoresis separation, and increased the accuracy of sex determination of calves (from 88.1%, 111/126 to 98.5%, 129/131; P &lt; 0.01). Biopsies containing dead and/or detached cells did not increase the NR incidence, but decreased the accuracy of sex determination of calves from 93.4% (240/257) to 86.6% (58/67; P &lt; 0.05). There were no relationships between NR incidences and embryo quality, nor between the sex determination accuracy of calves and embryo quality or stages. However, the NR incidence increased for PCR analyses of earlier development stages (5.1% at morula to early blastocyst) compared to blastocyst (3.2%) and expanded blastocyst (2.2%; P &lt; 0.05). The sex determination accuracy decreased to 77.4% (65/84) when embryos with unclear or expanded and faint female electrophoresis bands were transferred compared to those with clear bands (97.1%, 233/240). Field data suggest that larger biopsies during embryo sexing favor the effectiveness and accuracy of the YCD technique; however, increased sample size may affect the embryo survival, resulting in a decrease in the pregnancy success of embryo transfer. Reduced accuracy in YCD analyses using dead or detached blastomeres may be caused by the loss of male genes in dead or degenerated cells. Increased NR incidence in sampling of ZP for analysis may be due to biopsy loss when transferring the biopsy at the sampling step of the YCD method. In addition, the accuracy of sexing will be lower when embryos with unclear electrophoresis results are used. It is concluded that a proper and stage-dependent size of biopsy should be collected and used to ensure the accuracy of sex determination without reducing embryo survival, and the inclusion of a few live cells in a biopsy is important to the success of the sexing determination of this technique.

Hypoglycemia leads to age-related loss of vision

The retina is among the most metabolically active tissues in the body, requiring a constant supply of blood glucose to sustain function. We assessed the impact of low blood glucose on the vision of C57BL/6J mice rendered hypoglycemic by a null mutation of the glucagon receptor gene, Gcgr. Metabolic stress from moderate hypoglycemia led to late-onset loss of retinal function in Gcgr(-/-) mice, loss of visual acuity, and eventual death of retinal cells. Retinal function measured by the electroretinogram b-wave threshold declined >100-fold from age 9 to 13 months, whereas decreases in photoreceptor function measured by the ERG a-wave were delayed by 3 months. At 10 months of age Gcgr(-/-) mice began to lose visual acuity and exhibit changes in retinal anatomy, including an increase in cell death that was initially more pronounced in the inner retina. Decreases in retinal function and visual acuity correlated directly with the degree of hypoglycemia. This work demonstrates a metabolic-stress-induced loss of vision in mammals, which has not been described previously. Linkage between low blood glucose and loss of vision in mice may highlight the importance for glycemic control in diabetics and retinal diseases related to metabolic stress as macular degeneration.

Cardiac troponin I and ventricular arrhythmia in patients with chronic heart failure

BACKGROUND

Both detectable serum cardiac troponin I (cTnI) and ventricular dysrhythmias are common in patients with chronic heart failure (CHF) and are paralleled with the severity of the CHF. However, the relationship between serum cTnI and ventricular arrhythmia severity in patients with CHF remains unknown; the mechanism of the ventricular arrhythmia in the CHF patients also remains unclear.

MATERIALS AND METHODS

The study group included 218 patients with CHF who had cTnI assay drawn at the time of initial presentation. Patients with acute myocardial infarction or myocarditis were excluded from the analysis. The patients were divided into two groups: cTnI-positive with serum cTnI > 0.5 ng mL(-1) (n = 98) and cTnI-negative with serum cTnI < or = 0.5 ng mL(-1) (n = 120). The severity of ventricular dysrhythmias was assessed by 24-h Holter monitoring, using prospectively defined measures of ventricular arrhythmic burden.

RESULTS

Prevalence of risk factors for ventricular dysrhythmias was equal in both groups. All measures of ventricular ectopy were much higher in patients of the cTnI-positive groups. Mean hourly ventricular pairs (13.59 +/- 10.3 vs. 11.1 +/- 6.01, P = 0.027), mean hourly repetitive ventricular beats (26.01 +/- 13.67 vs. 22.01 +/- 13.56, P = 0.032), and the frequency of ventricular tachycardia episodes per 24 h (12.54 +/- 16.68 vs. 7.68 +/- 11.54, P = 0.012) were higher in patients with detectable cTnI levels. After inclusion of clinical variables and drug therapies in a multivariate analysis, the positive relationship between cTnI and the frequency of ventricular pairs (P = 0.03), repetitive ventricular beats (P = 0.037), and ventricular tachycardia (P = 0.03) remained independent. In multivariate logistic regression, the risk of developing ventricular tachycardia was higher in patients with detectable cTnI levels with an adjusted odds ratio (OR) of 2.31 (95% CI, 1.22-2.65, P = 0.003).

CONCLUSIONS

In patients with CHF, serum cTnI is closely related to increased occurrence of ventricular dysrhythmias and could identify a subgroup of patients with ventricular tachycardia. The minimal myocardial injury detected by serum cTnI might be the abnormal substrate for ventricular dysrhythmias.

Effect of Ga and Mn doping on structural, electrical transport and magnetic properties of Na(0.75)CoO(2)

The effects of doping with magnetic Mn ions or nonmagnetic Ga ions on the structural, electrical transport and magnetic properties of Na(0.75)CoO(2) have been investigated. It has been found that the lattice parameter c of the samples increases with Ga or Mn ion doping. Ga doping raises the electrical resistivity of Na(0.75)CoO(2), but the metallic conducting behaviour of the compound has not been influenced. In contrast, 5% Mn doping leads to a metal-insulator transition at low temperatures in Na(0.75)Co(1-y)Mn(y)O(2). The susceptibility of the Ga doped sample shows strong magnetic field dependence, while the susceptibility of the Mn doped samples is not very sensitive to the magnetic field. This work implies that magnetic interaction plays an important role in Na(x)CoO(2).

Glucagon-like peptide-2 protects against TPN-induced intestinal hexose malabsorption in enterally refed piglets

Premature infants receiving chronic total parenteral nutrition (TPN) due to feeding intolerance develop intestinal atrophy and reduced nutrient absorption. Although providing the intestinal trophic hormone glucagon-like peptide-2 (GLP-2) during chronic TPN improves intestinal growth and morphology, it is uncertain whether GLP-2 enhances absorptive function. We placed catheters in the carotid artery, jugular and portal veins, duodenum, and a portal vein flow probe in piglets before providing either enteral formula (ENT), TPN or a coinfusion of TPN plus GLP-2 for 6 days. On postoperative day 7, all piglets were fed enterally and digestive functions were evaluated in vivo using dual infusion of enteral ((13)C) and intravenous ((2)H) glucose, in vitro by measuring mucosal lactase activity and rates of apical glucose transport, and by assessing the abundances of sodium glucose transporter-1 (SGLT-1) and glucose transporter-2 (GLUT2). Both ENT and GLP-2 pigs had larger intestine weights, longer villi, and higher lactose digestive capacity and in vivo net glucose and galactose absorption compared with TPN alone. These endpoints were similar in ENT and GLP-2 pigs except for a lower intestinal weight and net glucose absorption in GLP-2 compared with ENT pigs. The enhanced hexose absorption in GLP-2 compared with TPN pigs corresponded with higher lactose digestive and apical glucose transport capacities, increased abundance of SGLT-1, but not GLUT-2, and lower intestinal metabolism of [(13)C]glucose to [(13)C]lactate. Our findings indicate that GLP-2 treatment during chronic TPN maintains intestinal structure and lactose digestive and hexose absorptive capacities, reduces intestinal hexose metabolism, and may facilitate the transition to enteral feeding in TPN-fed infants.

Molecular evolution and intragenic recombination of the merozoite surface protein MSP-3alpha from the malaria parasite Plasmodium vivax in Thailand

The merozoite surface antigens of malaria parasites are prime anti-morbidity/mortality vaccine candidates. However, their highly polymorphic nature requires extensive surveys of parasite populations to validate vaccine designs. Previous studies have found 3 molecular types (A, B and C) of the Plasmodium vivax merozoite surface protein 3a (PvMSP-3alpha) among parasite field populations. Here we analysed complete PvMSP-3alpha sequences from 17 clinical P. vivax isolates from Thailand and found that the nucleotide diversity was as high as that from samples widely separated by time and space. The polymorphic sites were not randomly distributed but concentrated in the N-terminal Ala-rich domain (block 2A), which is partially deleted in type B and C sequences. The size variations among type A sequences were due to small indels occurring in block 2A, whereas type B and C sequences were uniform in length with each type having a different large deletion. Analysis of synonymous and non-synonymous substitutions suggested that different selection forces were operating on different regions of the molecule. The numerous recombination sites detected within the Ala-rich domain suggested that intragenic recombination was at least partially responsible for the observed genetic diversity of the PvMSP-3alpha gene. Phylogenetic analysis failed to link any alleles to a specific geographical origin, even when different domains of PvMSP-3alpha were used for analysis. The highly polymorphic nature and lack of geographical clustering of isolates suggest that more systematic investigations of the PvMSP-3alpha gene are needed to explore its evolution and vaccine potential.

Diffuse cavernous hemangioma of the rectosigmoid colon

Diffuse cavernous hemangioma of the rectosigmoid colon is an uncommon benign vascular lesion. We report 5 cases of diffuse cavernous hemangioma, focusing on the clinical features, diagnosis procedure and treatment. Five patients have undergone sphincter-saving procedures, 3 cases had coloanal sleeve anastomoses and 1 patient each had pull-through anastomosis and lower anterior resection. During the follow-up, which ranged from 3 to 10 years, 3 patients had no further anal bleeding and 2 patients had minor intermittent anal bleeding. Continence for normal stool was satisfactory in all patients. In conclusion, sphincter-saving procedure is most appropriate and curative approach for the treatment of diffuse cavernous hemangioma. Imaging study plays an important role in the diagnosis, preoperative staging and follow-up.

Greater capillary-fiber interface per fiber mitochondrial volume in skeletal muscles of old rats

The objective was to examine whether muscle structural capacity for O2 flux (i.e., capillary-to-fiber surface ratio) relative to fiber mitochondrial volume deteriorates with the muscle atrophy of aging in predominantly slow- (soleus, S) and fast-twitch (extensor digitorum longus, EDL) muscles of old (24 mo) and very old (35 mo) F344BN rats compared with adult (12 mo old). Wet muscle mass decreased 29% (196 +/- 4 to 139 +/- 5 mg) in S and 22% (192 +/- 3 to 150 +/- 3 mg) in EDL between 12 and 35 mo of age, without decline in body mass. Capillary density increased 65% (1,387 +/- 54 to 2,291 +/- 238 mm(-2)) in S and 130% (964 +/- 95 to 2,216 +/- 311 mm(-2)) in EDL, because of the muscle fiber atrophy, whereas capillary per fiber number remained unchanged. Altered capillary geometry, i.e., lesser contribution of tortuosity and branching to capillary length, was found in S at 35 compared with 12 and 24 mo, and not in EDL. Accounting for capillary geometry revealed 55% (1,776 +/- 78 to 2,750 +/- 271 mm(-2)) and 113% (1,194 +/- 112 to 2,540 +/- 343 mm(-2)) increases in capillary length-to-fiber volume ratio between 12 and 35 mo of age in S and EDL, respectively. Fiber mitochondrial volume density was unchanged over the same period, causing mitochondrial volume per micrometer fiber length to decrease in proportion to the fiber atrophy in both muscles. As a result of the smaller fiber mitochondrial volume in the face of the unchanged capillary-to-fiber number ratio, capillary-to-fiber surface ratio relative to fiber mitochondrial volume not only did not deteriorate, but in fact increased twofold in both muscles between 12 and 35 mo of age, independent of their different fiber type.

Morphological analysis of leucocyte transmigration in the pleural cavity

The role that pleural mesothelial cells play in leucocyte transmigration into the pleural cavity was investigated in lipopolysaccharide-stimulated mice. Changes in mesothelial cell morphology and changes in expression of adhesion molecules on mesothelial cells and leucocytes were analysed by light microscopy, immunohistochemistry, transmission electron microscopy (TEM) and immuno-scanning electron microscopy (immuno-SEM). After stimulation, the mesothelial cells separated completely from one another before leucocyte penetration across the mesothelial layer occurred. These changes occurred primarily in the immediate vicinity of ribs, where a large number of leucocytes accumulated. Immuno-SEM showed that the expression of intercellular adhesion molecule-1 (ICAM-1) on the parietal pleural mesothelial cells was significantly up-regulated by lipopolysaccharide stimulation, and that of vascular cell adhesion molecule-1 (VCAM-1) was induced. Both were restricted to the microvilli of the mesothelial cells. By contrast, expression of intercellular adhesion molecule-2 (ICAM-2), platelet/endothelial cell adhesion molecule-1 (PECAM-1), mucosal addressin cell adhesion molecule-1 (MAdCAM-1), endothelial leucocyte adhesion molecule-1 (ELAM-1), peripheral node addressin (PNAd) and fibronectin were not detected. Lymphocyte function associated antigen-1 (LFA-1), macrophage-1 molecule (Mac-1) and very late appearing antigen-4 (VLA-4), all ligands of ICAM-1 and VCAM-1, were present on the transmigrated neutrophils and macrophages. These findings demonstrate that the immediate vicinity of ribs is a source of leucocyte migration into the pleural space.

Immobilized MICA could expand human Vdelta1 gammadelta T cells in vitro that displayed major histocompatibility complex class I chain-related A-dependent cytotoxicity to human epithelial carcinomas

Human major histocompatibility complex class I chain-related A (MICA) is a human leucocyte antigen-related polymorphic molecule, which is expressed on many kinds of epithelial tumours and can be recognized by the Vdelta1 subset of gammadelta T cells. In the present study, monoclonal antibodies (MoAbs) were produced in mice immunized with recombinant MICA (rMICA)*008. It was found that MICA was expressed on ovarian and colonic tumour tissues and could be detected by these anti-MICA MoAbs. The immobilized rMICA could induce the proliferation of human ovarian epithelial carcinoma- or colonic carcinoma-derived gammadelta T cells of the Vdelta1 phenotype in vitro. These Vdelta1 T cells displayed a strong, broad-range cytolytic activity towards tumour cell lines positive for MICA. The efficiency of this cytolytic activity depended greatly on the level of MICA expressed on the cell surface and could be inhibited by anti-MICA MoAbs. Therefore, MICA may play an important role in immune responses against epithelial tumours and function as a stimulating factor for the growth of Vdelta1 gammadelta T cells, whereas MICA-reactive Vdelta1 gammadelta T cells might serve as a new candidate for adoptive cellular therapy of tumours.

Lower blood glucose, hyperglucagonemia, and pancreatic alpha cell hyperplasia in glucagon receptor knockout mice

Glucagon, the counter-regulatory hormone to insulin, is secreted from pancreatic alpha cells in response to low blood glucose. To examine the role of glucagon in glucose homeostasis, mice were generated with a null mutation of the glucagon receptor (Gcgr(-/-)). These mice display lower blood glucose levels throughout the day and improved glucose tolerance but similar insulin levels compared with control animals. Gcgr(-/-) mice displayed supraphysiological glucagon levels associated with postnatal enlargement of the pancreas and hyperplasia of islets due predominantly to alpha cell, and to a lesser extent, delta cell proliferation. In addition, increased proglucagon expression and processing resulted in increased pancreatic glucogen-like peptide 1 (GLP-1) (1-37) and GLP-1 amide (1-36 amide) content and a 3- to 10-fold increase in circulating GLP-1 amide. Gcgr(-/-) mice also displayed reduced adiposity and leptin levels but normal body weight, food intake, and energy expenditure. These data indicate that glucagon is essential for maintenance of normal glycemia and postnatal regulation of islet and alpha and delta cell numbers. Furthermore, the lean phenotype of Gcgr(-/-) mice suggests glucagon action may be involved in the regulation of whole body composition.

Dose-dependent promotion by phenylethyl isothiocyanate, a known chemopreventer, of two-stage rat urinary bladder and liver carcinogenesis

The effects of phenylethyl isothiocyanate (PEITC) on urinary bladder and liver carcinogenesis were analyzed in a rat model. Diets containing 0.1%, 0.05%, or 0.01% PEITC were administered for 32 wk to male Fischer 344 rats with and without pretreatment with an injection of diethylnitrosamine (200 mg/kg body wt i.p.) and 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine in the drinking water for 4 wk for initiation. In the initiated groups, PEITC administration significantly increased the incidences of papillary or nodular hyperplasia, dysplasia, and transitional cell carcinomas at higher doses of 0.01%, 0.01%, and 0.05%, respectively, compared with the control group, given initiation alone, in a dose-dependent manner. Without initiation, administration of 0.1% and 0.05% PEITC induced simple and papillary or nodular hyperplasia and dysplasia in the urinary bladder. In the liver, induction of glutathione S-transferase placental form-positive foci was dose dependently enhanced by PEITC administration, but the incidences of liver tumors were not different among the groups. From the present experiment, we can conclude that > 0.01% PEITC enhances rat urinary bladder carcinogenesis, while weakly promoting hepatocarcinogenesis. In addition, it is suggested that > 0.05% PEITC has tumorigenic potential.

Cognitive impairment in Parkinson's disease revealed by event-related potential N270

Disturbed cognitive function is a well-recognized feature of idiopathic Parkinson's disease (PD). The aim of this study was to find a susceptive index to reveal the minor cognitive impairment in PD patients. Thirty PD patients without clinical dementia and thirty-four age-matched normal controls performed a matching task while event-related potentials (ERPs) were recorded from their scalp. There were two kinds of stimulus pairs in this study: match condition, the second stimulus (S2) in a pair was identical to the first one (S1); conflict condition, S2 conflicted with S1 in the color attribute. Subjects were required to press a button in the match condition and another button in the conflict condition. A negative ERP component, N270, which was considered to reflect the conflict processing activity in human brain, was evoked by the S2 of the conflict condition. The patient group showed a delayed and smaller N270 than the control group. The prolongation of its peak latency was significant at P3 and P4 electrodes and the reduction of its mean amplitude was significant at P3 electrode. The amplitude of P300 elicited in the match condition was decreased in the patient group at P4 electrode but its latency did not differ from the control group. These results indicate that PD patients as a group showed cognitive decline even in the absence of clinical dementia. N270 is a sensitive index in revealing this minor cognitive impairment.

A nonspecific nucleoside hydrolase from Leishmania donovani: implications for purine salvage by the parasite

In contrast to their mammalian hosts, protozoan parasites do not synthesize purines de novo, but depend on preformed nucleotides that they purportedly obtain by salvage pathways. Nucleoside hydrolases may play a crucial role in that salvage process. By screening Leishmania donovani libraries with polyclonal antibodies against promastigote soluble exo-antigens, we have identified a cDNA encoding a protein with significant homology to nonspecific and uridine-inosine-preferring nucleoside hydrolases. Sequence comparison demonstrated that all the residues involved in Ca(2+)-binding and substrate recognition in the active site are conserved among the characterized protozoan nucleoside hydrolases. Genomic analysis suggests that it is a single copy gene in L. donovani, and its homologues are present in members representing other Leishmania species complexes. Both Northern blot and immunoblot analyses indicate that it is constitutively expressed in L. donovani promastigotes. The recombinant enzyme overexpressed in and purified from bacteria showed significant activity with all naturally occurring purine and pyrimidine nucleosides, and efficient utilization of p-nitrophenyl-beta-D-ribofuranoside as a substrate. Altogether, the sequence comparison and substrate specificity data identify this L. donovani nucleoside hydrolase as a nonspecific nucleoside hydrolase. Further, the nucleoside hydrolase was localized to specific foci in L. donovani promastigotes by immunofluorescent assays. Although the conservation of the nucleoside hydrolases among protozoan parasites offers promise for the design of broad-spectrum anti-parasitic drugs, the existence of multiple and distinct nucleoside hydrolases in a single species demands special consideration.

Plasmodium falciparum: differential display analysis of gene expression during gametocytogenesis

With the Plasmodium falciparum genome sequencing near completion, functional analysis of individual parasite genes has become the major task of the postgenomic era. Understanding the expression patterns of individual genes is the initial step toward this goal. In this report, we have examined gene expression during gametocytogenesis of the malaria parasite, P. falciparum, using a modified differential display (DD) method. The modifications of this method include adjusting the dNTP mix, using upstream primers with higher AT contents, and reducing the extension temperature of the polymerase chain reaction (PCR). With a combination of 16 arbitrary upstream primers and 3 one-base-anchored oligo(dT) primers, we have successfully cloned 80 unique cDNA tags from stage IV-V gametocytes. Further analysis by dot blots and semiquantitative reverse transcriptase-PCR showed that at least 49 cDNAs had induced or elevated levels of expression in gametocytes. These results indicate that this modified DD procedure is suitable for large-scale identification of developmentally regulated genes in the AT-rich Plasmodium genome.

Sequence and chromosomal assignment of a human novel cDNA: similarity to gamma-aminobutyric acid transporter

Gamma-aminobutyric acid (GABA) is the predominant inhibitory neurotransmitter in the mammalian brain. Although initially thought to be confined to the central nervous system, GABAergic activity has also been described in other tissues throughout the body. In the present study, we report the cloning and localization of human GABA transporter cDNA and document its expression in various human tissues. A human liver cDNA library was initially screened by a 32P-labeled murine brain GABA transporter 3 (GAT-3) cDNA probe, and full-length cDNA was cloned by employing Marathon-Ready human kidney cDNA. The human GABA transporter cDNA encoded a 569 amino acid hydrophobic protein with 12 transmembrane domains (TMs). Search of published sequences revealed high homology with rat GAT-2, murine GAT-3 cDNA, human solute carrier family 6 member 13 (SLC6A13), and a human peripheral betaine/GABA transporter. Northern blot analyses demonstrated that the human GABA transporter is expressed strongly in the kidney and to a lesser extent in the liver and brain. The sequence was well matched with human chromosome 12p13.3, suggesting the human GABA transporter contains 14 exons. The above findings confirm the existence of and further characterize a specific GABA transporter in human tissues.

Tissue-engineered bone repair of sheep cranial defects with autologous bone marrow stromal cells

Cranial bone defect remains a major challenge to craniofacial surgeons because of limited availability of autologous bone graft to repair the defects and the donor site defects secondary to tissue harvesting. In contrast, tissue-engineering technique can generate a large bone tissue using small amount of autologous cells and therefore avoid these problems. Bone Marrow Stromal Cells (MSCs) have the potential of multi-lineage (including osteogenic) differentiation. The objective of this study was to investigate the potential of using autologous MSCs to repair cranial bone defects by a tissue-engineering approach. Autologous MSCs were isolated from eight adult sheep respectively and were in vitro expanded and induced to become osteogenic cells. Bilateral full-thickness defects (20 mm in diameter) of parietal bones were created in animals and the bone defects were either repaired with the bone implants constituted with MSCs and calcium alginate at the experimental side (n = 8) or treated with calcium alginate only without MSCs (n = 4) or left unrepaired (n = 4) at the control side. New bone tissues were observed either grossly or histologically at the defects of experimental group as early as 6 weeks post-repairing, but not in control groups. The engineered bone tissue became more mature at 18 weeks post-repairing. Three-dimensional computerized tomography (CT) scan revealed an almost complete repair of the defect of experimental group at 18 weeks. This study may provide insight for future clinical repair of cranial defect.

The dielectrophoretic levitation and separation of latex beads in microchips

A linear travelling wave dielectrophoretic (twDEP) microchip was fabricated and used to investigate both the levitation and the twDEP motion of latex beads as a function of applied potential and frequency, suspending medium conductivity, bead size, and surface characteristics. The surface conductance of the latex beads was characterised by measurement of the dielectrophoretic (DEP) crossover frequency. Collection of sample prior to initiation of twDEP was achieved using positive DEP forces generated by an integrated pair of parallel electrodes positioned in front of the twDEP array within the microfluidic channel. The principle of linear twDEP separation is shown using latex beads and rabbit heart cells.

Spatial distribution of cell adhesion molecules on the peritoneal surface in the cecal perforation-induced peritonitis

For understanding the immunological functions of the peritoneum, spatial localization of integrins and their ligands was studied by immuno-SEM on the peritoneal surface of mice with cecal perforation-induced peritonitis. The cecal peritoneum 24 hr after perforation was stained with specific antibodies against LFA-1, Mac-1, VLA-4, ICAM-1, VCAM-1, and fibronectin diluted with cold University of Wisconsin (UW) solution in conjunction with immuno-gold labeling. The spatial localization of those cell adhesion molecules was detected by backscatter electron (BSE) imaging with field emission scanning electron microscope (FESEM). Numerous leukocytes with diverse surface ultrastructure were observed on the peritoneal surface by FESEM. Some leukocytes were in contact with mesothelial cells, and others adhered to the exposed underlying connective tissue. The BSE imaging showed the ubiquitous distribution of Mac-1 on all membrane domains of leukocytes, i.e., cell body, ruffles, and microvilli. In contrast, predominant expressions of LFA-1 and VLA-4 were discernible on ruffles/microvilli of some leukocytes. The mesothelial cells remaining in the inflamed area expressed both ICAM-1 and VCAM-1 on their microvilli. The fibronectin was detected on presumable collagen fibers and/or fibrin over the exposed smooth muscle layer as well as on fibrin extending between leukocyte aggregation. The spatial microlocalization of integrins was clarified on the leukocytes emigrated in peritonitis, and their ligands were detected on the inflamed peritoneum.

The emergence and evolution of methicillin-resistant Staphylococcus aureus

Significant advances have been made in recent years in our understanding of how methicillin resistance is acquired by Staphylococcus aureus. Integration of a staphylococcal cassette chromosome mec (SCCmec) element into the chromosome converts drug-sensitive S. aureus into the notorious hospital pathogen methicilin-resistant S. aureus (MRSA), which is resistant to practically all beta-lactam antibiotics. SCCmec is a novel class of mobile genetic element that is composed of the mec gene complex encoding methicillin resistance and the ccr gene complex that encodes recombinases responsible for its mobility. These elements also carry various resistance genes for non-beta-lactam antibiotics. After acquiring an SCCmec element, MRSA undergoes several mutational events and evolves into the most difficult-to-treat pathogen in hospitals, against which all extant antibiotics including vancomycin are ineffective. Recent epidemiological data imply that MRSA has embarked on another evolutionary path as a community pathogen, as at least one novel SCCmec element seems to have been successful in converting S. aureus strains from the normal human flora into MRSA.

Zinc status affects p53, gadd45, and c-fos expression and caspase-3 activity in human bronchial epithelial cells

This study was designed to examine the influence of zinc depletion and supplementation on the expression of p53 gene, target genes of p53, and caspase-3 activity in normal human bronchial epithelial (NHBE) cells. A serum-free, low-zinc medium containing 0.4 micromol/l of zinc [zinc deficient (ZD)] was used to deplete cellular zinc over one passage. In addition, cells were cultured for one passage in media containing 4.0 micromol/l of zinc [zinc normal (ZN)], which represents normal culture concentrations (Clonetics); 16 micromol/l of zinc [zinc adequate (ZA)], which represents normal human plasma zinc levels; or 32 micromol/l of zinc [zinc supplemented (ZS)], which represents the high end of plasma zinc levels attainable by oral supplementation in humans. Compared with ZN cells, cellular zinc levels were 76% lower in ZD cells but 3.5-fold and 6-fold higher in ZA and ZS cells, respectively. Abundances of p53 mRNA and nuclear p53 protein were elevated in treatment groups compared with controls (ZN). For p53 mRNA abundance, the highest increase (3-fold) was observed in ZD cells. In contrast, the highest increase (17-fold) in p53 nuclear protein levels was detected in ZS cells. Moreover, gadd45 mRNA abundance was moderately elevated in ZD and ZA cells and was not altered in ZS cells compared with ZN cells. Furthermore, the only alteration in c-fos mRNA and caspase-3 activity was the twofold increase and the 25% reduction, respectively, detected in ZS compared with ZN cells. Thus p53, gadd45, and c-fos and caspase-3 activity appeared to be modulated by cellular zinc status in NHBE cells.

Mutations of the Walker B motif in the first nucleotide binding domain of multidrug resistance protein MRP1 prevent conformational maturation

ATP-binding cassette (ABC) transporters couple the binding and hydrolysis of ATP to the translocation of solutes across biological membranes. The so-called "Walker motifs" in each of the nucleotide binding domains (NBDs) of these proteins contribute directly to the binding and the catalytic site for the MgATP substrate. Hence mutagenesis of residues in these motifs may interfere with function. This is the case with the MRP1 multidrug transporter. However, interpretation of the effect of mutation in the Walker B motif of NBD1 (D792L/D793L) was confused by the fact that it prevented biosynthetic maturation of the protein. We have determined now that this latter effect is entirely due to the D792L substitution. This variant is unable to mature conformationally as evidenced by its remaining more sensitive to trypsin digestion in vitro than the mature wild-type protein. In vivo, the core-glycosylated form of that mutant is retained in the endoplasmic reticulum and degraded by the proteasome. A different substitution of the same residue (D792A) had a less severe effect enabling accumulation of approximately equal amounts of mature and immature MRP1 proteins in the membrane vesicles but still resulted in defective nucleotide interaction and organic anion transport, indicating that nucleotide hydrolysis at NBD1 is essential to MRP1 function.

[Arthropod community structures in transgenic Bt cotton fields]

Arthropod community structures were investigated in transgenic Bt cultivars, Bollgard(B) and Chinese cotton 30 (CC30), and common cultivars, control (C) and no control (NC) cotton field in North China in 1998. The results showed that compared with common cultivars, the species richness and the number of total individual of arthropod community in transgenic Bt cultivars field were reduced 2.4-16.3% and 71.0-78.3% respectively, in which dominant species in phytophagous subcommunity varied. The number of individual of predatory and parastic subcommunity were all increased. The similarity coefficient between CC30 and NC was 0.8243, B and NC 0.7320, B and C 0.3380, C and NC 0.3128, CC30 and C 0.2665. The order of diversity and evenness value of these were CC30 (2.3712 and 0.6428), NC (2.3654 and 0.6251), B (2.1364 and 0.5791), and C (1.0877 and 0.2949), their dominant value was 0.8726 (C), 0.3528(B), 0.1178(NC) and 0.1048 (CC30) respectively. It was concluded that different integrated pest management (IPM) strategy should be implemented in transgenic Bt cotton instead of common variety cotton field.

Group sequential test strategies for superiority and non-inferiority hypotheses in active controlled clinical trials

In a group sequential active controlled clinical trial, the study hypothesis may be a superiority hypothesis that an experimental treatment is more effective than the active control therapy or a non-inferiority hypothesis that the treatment is no worse than the active control within some non-inferiority range. When it is necessary to plan for testing the superiority and the non-inferiority hypotheses, we propose an adaptive group sequential closed test strategy by which the sample size is planned for testing superiority and is to be increased for showing non-inferiority given that it is deemed more plausible than superiority based on the observed sample path during the course of the trial. The proposed adaptive test strategy is valid in terms of having the type I error probability maintained at the targeted alpha level for both superiority and non-inferiority. It has power advantage or sample size saving over the traditional group sequential test designed for testing either superiority only or non-inferiority only.

Isolation in Brazil of nosocomial Staphylococcus aureus with reduced susceptibility to vancomycin

OBJECTIVE

To evaluate the possible presence of vancomycin-resistant Staphylococcus aureus (VRSA) in a Brazilian hospital.

DESIGN

Epidemiological and laboratory investigation of nosocomial VRSA.

METHODS

140 methicillin-resistant S aureus strains isolated between November 1998 and October 1999 were screened for susceptibility to vancomycin. The screening was carried out by using brain-heart infusion agar (BHIA) supplemented with 4, 6, and 8 microg/mL of vancomycin. The minimum inhibitory concentration (MIC) determination was carried out as standardized by the National Committee for Clinical Laboratory Standards using the broth macrodilution, agar-plate dilution, and E-test methods.

PATIENTS

Hospitalized patients exposed to vancomycin.

RESULTS

5 of the 140 isolates had a vancomycin MIC of 8 microg/mL by broth macrodilution, agar plate dilution, and E-test methods. Four VRSA strains were isolated from patients in a burn unit who had been treated with vancomycin for more than 30 days, and one from an orthopedic unit patient who had received vancomycin treatment for 7 days. Pulsed-field gel electrophoresis characterized four of the VRSA strains as belonging to the Brazilian endemic clone. All five strains were negative for vanA, vanB, and vanC genes by polymerase chain reaction. Transmission electron microscopy of the five strains revealed significantly thickened cell walls. One patient died due to infection caused by the VRSA strain.

CONCLUSIONS

This is the first report of isolation of VRSA in Brazil and the first report of isolation of multiple VRSA strains from one facility over a relatively short period of time. This alerts us to the possibility that VRSA may be capable of nosocomial transfer if adequate hospital infection control measures are not taken.

[Analysis of writing age of ballpoint pen ink by thin-layer chromatography]

A method based on using a thin-layer chromatographic method (TLC) for determining changes in dye of ballpoint pen ink developed with writing age. An ink drawn line of 1 cm in length was cut and placed in Eppendorf tube. Extraction was performed with 20 microL ethanol at room temperature for 15 min, and heated in steambath for 10 min. The ethanol solution(4 microL) containing the extracted dyes was then spotted on TLC plate by syringe after cooling. The ballpoint pen ink spots were eluted in a solvent of isopropyl alcohol. Using TLC scanner, the spots on TLC plate were scanned at 580 nm. The relations between ratio of peak heights and writing age were attained. Thus, the information on relative writing age can be obtained. And, the powerful evidence for identifying the age of ballpoint pen ink is provided by this method in the field of forensic science.

[Autoantibodies against the myocardium beta 1-adrenergic and M2-muscarinic receptors in patients with heart failure]

OBJECTIVE

To determine whether the autoantibodies against beta(1)-adrenergic and M(2)-muscarinic receptors are related to congestive heart failure (CHF) patients with different cardiac diseases.

METHODS

Both synthetic peptides corresponding to amino acids sequence of the second extracellular loops of the beta(1) and M(2) receptors were used as the antigens to screen the serum from CHF patients with ischemic cardiomyopathy (ICD, n = 42), idiopathic dilated cardiomyopathy (IDCM, n = 52) and hypertensive heart disease (HHD, n = 44). Meanwhile healthy donors were tested as normal controls (NC, n = 40).

RESULTS

The positive rates of serum for beta(1)-adrenergic-receptor were 45.7% (86/188) and 10.4% (8/77) in CHF patients and controls respectively (P < 0.01); the positive rates of serum for M(2)-muscarinic receptor were 52.7% (99/188) and 11.7% (9/77) in CHF patients and controls (P < 0.01). The frequencies of the both receptor autoantibodies in patients with cardiac function of class II approximately III were significantly higher than those with cardiac function of class VI.

CONCLUSIONS

Our finding indicates indicates that autoantibodies against beta(1)-adrenergic-receptor and M(2)-muscarinic receptor can be detected not only in the serum of CHF patients with IDCM, but also in CHF patients with ICM and HHD. It is suspected that autoantibodies against beta(1) and M(2) receptors may be related to the myocardial remodeling and/or CHF.

The mechanism of cerebral evoked potentials by repetitive magnetic stimulation of gastrocnemius muscle in Duchenne muscular dystrophy

OBJECTIVE

To study the features and mechanism of the cerebral evoked potentials by repetitive stimulation of calf muscle in Duchenne muscular dystrophy (DMD) patients with obvious muscular dystrophy and psuedohypertrophy.

METHODS

Cerebral evoked potentials by stimulation of calf muscles and somatosensory evoked potentials (SEPs) by the stimulation of posterior tibial nerves at ankle were measured in 10 patients with DMD and 10 normal controls matched with gender and age. The intensity of the magnetic stimulation was at 30% of maximal output (2.1 Tesla, MagPro magnetic stimulator, Dantec) and the frequency was 1 Hz. The low intensity of magnetic stimulation was just sufficient to produce a contraction of the muscle belly underneath the coil. Recording electrode was placed at 2 cm posterior to the Cz, reference to Fpz. The latencies of N33, P38, N48 and P55 and amplitude (P38 - N48) were recorded. SEPs were recorded by routine methods.

RESULTS

In normal subjects, the amplitudes of cerebral evoked potentials by magnetic stimulation of calf muscle was 40% lower than that by electrical stimulation of the posterior tibial nerves at ankle. The latency of P38 was 2.9 +/- 2.1 ms longer compared with electrical stimulation of the posterior tibial nerves at ankle. In 6 patients, P38 latency from magnetic stimulation was remarkably prolonged (P < 0.01), and in 4 patients, there was no remarkable response. SEPs evoked by electrical stimulation were normal in all of the patients.

CONCLUSION

DMD is an available model for the study of mechanism of cerebral evoked potentials by magnetic stimulating muscle. We can conclude that the responses from magnetic stimulation were produced by muscle input. The abnormal responses in patients may relate to decreased input of muscle by stimulating dystrophic and psedohypertrophic muscle.

Optimisation of an ELISA for the serodiagnosis of visceral leishmaniasis using in vitro derived promastigote antigens

An antibody detection ELISA was developed for diagnosis of visceral leishmaniasis. Antigens released by Leishmania donovani promastigotes into a protein-free medium were used. SDS-PAGE analysis has indicated that Ld-ESM contain several protein antigens. Titration and chequer-board analyses were performed to optimise the assay protocol. Optimal results were obtained when antigen (50 microg/ml) was coated with PBS-methyl glyoxal buffer, and wells blocked with 0.5% casein. A serum dilution of 1:500 in antigen-coated wells, blocked with 0.5% casein, generated lowest absorbance with Ref-ve sera and higher absorbance with Ref+ve sera. All steps of the ELISA were performed at room temperature. The S/N ratio, the differential absorbance between the negative sample vs. the test or Ref+ve sample, was used to quantify the specific antigen and antibody reactions. An anti-human monoclonal antibody conjugated with HRP (MAb-conjugate) outperformed a commercially available anti-human polyclonal antibody conjugate (PAb-conjugate). The MAb-conjugate gave minimal background reactions with endemic sera. Optimised final assay steps mentioned below were used to evaluate sera samples from field trials. ELISA wells were coated with 50 microg/ml Ld-ESM mixed in PBS-methyl glyoxal overnight, and after removing the antigen, blocked with 0.5% casein for 1 h at RT. Patient sera along with control sera, diluted to 1:500 in PBS/T, were reacted for 1 h at RT. After washing the plate with PBS/T, wells were reacted with MAb-conjugate for 40 min at RT, and after washing, binding of antibodies was visualized by using TMB as a chromogen substrate. The relative specific binding was quantified by the S/N ratio. A batch of n=22 endemic sera from North Africa were evaluated and resulted with 100% specificity and sensitivity, 99.99% PPV and 95.45% NPV. The specificity and sensitivity of this assay will be further evaluated in planned retrospective and prospective multi-site trials.

Different processes are involved in human brain for shape and face comparisons

Fifteen subjects participated in a matching task of visual stimuli. Two sequentially presented stimuli in a pair were the same shape (shape match), different shapes (shape mismatch), same human face (face match) or different faces (face mismatch). All four kinds of stimulus pairs were of equal probability. The shape mismatch pairs elicited a negative event-related potential component N270 (Peak latency: 262.1+/-16.5 ms, P4) after the second stimulus onset, while the face mismatch evoked N270 with longer peak latency (301.2+/-19.8 ms, P4) and N450. There exists a specific system for mismatch processing of a complex stimulus (face) in the human brain.