Pioglitazone Enhances the Beneficial Effects of Glucocorticoids in Experimental Nephrotic Syndrome

Glucocorticoids are the primary therapy for nephrotic syndrome (NS), but have serious side effects and are ineffective in ~20-50% of patients. Thiazolidinediones have recently been suggested to be renoprotective, and to modulate podocyte glucocorticoid-mediated nuclear receptor signaling. We hypothesized that thiazolidinediones could enhance glucocorticoid efficacy in NS. We found that puromycin aminonucleoside-induced proteinuria in rats was significantly reduced by both high-dose glucocorticoids (79%) and pioglitazone (61%), but not low-dose glucocorticoids (25%). Remarkably, pioglitazone + low-dose glucocorticoids also reduced proteinuria (63%) comparably to high-dose glucocorticoids, whereas pioglitazone + high-dose glucocorticoids reduced proteinuria to almost control levels (97%). Molecular analysis revealed that both glucocorticoids and pioglitazone enhanced glomerular synaptopodin and nephrin expression, and reduced COX-2 expression, after injury. Furthermore, the glomerular phosphorylation of glucocorticoid receptor and Akt, but not PPARγ, correlated with treatment-induced reductions in proteinuria. Notably, clinical translation of these findings to a child with refractory NS by the addition of pioglitazone to the treatment correlated with marked reductions in both proteinuria (80%) and overall immunosuppression (64%). These findings together suggest that repurposing pioglitazone could potentially enhance the proteinuria-reducing effects of glucocorticoids during NS treatment.

Impact of attenuated plaques on TIMI grade flow and clinical outcomes of coronary artery disease patients: a systematic review and meta analysis

BACKGROUND

Plaques with a large necrotic core or lipid pool and thin-cap fibroatheroma manifest as attenuated plaques on intravascular ultrasound (IVUS). Their impact on TIMI grade flow and clinical outcomes remains undefined. We performed a systematic review and meta-analysis to summarize the association between attenuated plaque and distal embolization and clinical outcomes of coronary artery disease (CAD) from pooled data of published eligible cohort studies.

METHODS

We searched the literature on TIMI grade flow and clinical outcomes on PubMed, Ovid, EMBASE, the Cochrane Library, CNKI and WanFang databases. Study heterogeneity and publication bias were estimated.

RESULTS

A total of 3,833 patients were enrolled in nine studies. Five studies investigated TIMI grade flow and attenuated plaques. They revealed no difference in TIMI grade flow before percutaneous coronary intervention (PCI) between the attenuated and non-attenuated plaque group (RR =1.25; 95% CI: 0.65 to 2.41; P=0.50). After balloon dilation and stent implantation, the incidence of TIMI 0~2 grade flow in the attenuated plaque group was statistically significant higher than that of the non-attenuated plaque group (RR =4.73; 95% CI: 3.03 to 7.40; P<0.001). Five other studies investigated major cardiovascular events (MACEs) and attenuated plaques and found no difference in MACE rates within three years of follow up.

CONCLUSIONS

Our study presents the evidence that plaque with ultrasound signal attenuation would induce slow/no reflow phenomenon and distal embolization during PCI, but this appearance has no impact on MACE rates within three years.

Burden of hypertension in China over the past decades: Systematic analysis of prevalence, treatment and control of hypertension

AIMS

To review comprehensively the prevalence, treatment and control of hypertension; and to estimate the burden of hypertension in China, thereby aiding Chinese health policies for better prevention and control of this condition.

METHODS AND RESULTS

PubMed, EMbase, China National Knowledge Infrastructure, Wanfang and Chongqing VIP databases were searched for population-based studies published in English and Chinese that described prevalence, treatment and control of hypertension in China, as well as deaths and disabilities attributed to hypertension. All research papers were published between January 1999 and May 2014. Data from 178 studies involving over 2,901,464 participants covering 30 provinces were pooled. Overall, rates of prevalence, treatment and control of hypertension were 28.9%, 35.3% and 13.4% in China. A statistically significant association was observed between temperature gradient and the prevalence of hypertension. There were 10,667 (95% confidence interval 8063-13,345) disability-adjusted life years per 100,000 people. In total, 78.3% of disability-adjusted life years were from years lived with disability and 21.7% from years of life lost due to premature mortality.

CONCLUSIONS

Although there has been a slight improvement in rates for the treatment and control of hypertension, these rates were still suboptimal, especially for men and people living in rural areas. Low and middle-income provinces had a comparatively huge burden of hypertension, which is a considerable risk factor for reducing life expectancy. Our analysis may be helpful in generating a current overview of hypertension in China.

[Study of continuous quality improvement for clinical laboratory processes via the platform of Hospital Group]

OBJECTIVE

The program of continuous quality improvement in clinical laboratory processes for complete blood count (CBC) was launched via the platform of Beijing Children's Hospital Group in order to improve the quality of pediatric clinical laboratories.

METHODS

Fifteen children's hospitals of Beijing Children's Hospital group were investigated using the method of Chinese adapted continuous quality improvement with PDCA (Plan-Do-Check-Action). The questionnaire survey and inter-laboratory comparison was conducted to find the existing problems, to analyze reasons, to set forth quality targets and to put them into practice. Then, targeted training was conducted to 15 children's hospitals and the second questionnaire survey, self examinations by the clinical laboratories was performed. At the same time, the Group's online internal quality control platform was established. Overall effects of the program were evaluated so that lay a foundation for the next stage of PDCA.

RESULTS

Both quality of control system documents and CBC internal quality control scheme for all of clinical laboratories were improved through this program. In addition, standardization of performance verification was also improved, especially with the comparable verification rate of precision and internal laboratory results up to 100%. In terms of instrument calibration and mandatory diagnostic rates, only three out of the 15 hospitals (20%) failed to pass muster in 2014 from 46.67% (seven out of the 15 hospitals) in 2013. The abnormal data of intraday precision variance coefficients of the five CBC indicator parameters (WBC, RBC, Hb, Plt and Hct) of all the 15 laboratories accounted for 1.2% (2/165) in 2014, a marked decrease from 9.6% (14/145) in 2013. While the number of the hospitals using only one horizontal quality control object for daily quality control has dropped to three from five. The 15 hospitals organized a total of 263 times of training in 2014 from 101 times in 2013, up 160%.

CONCLUSION

The quality improvement program for the clinical laboratories launched via the Hospital Group platform can promote the joint development of the pediatric clinical laboratory discipline of all the member hospitals with remarkable improvement results, and the experience is recommendable for further rollout.

Prevalence of post-stroke cognitive impairment in china: a community-based, cross-sectional study

International hospital-based studies have indicated a high risk of cognitive impairment after stroke, evidence from community-based studies in China is scarce. To determine the prevalence of post-stroke cognitive impairment (PSCI) and its subtypes in stroke survivors residing in selected rural and urban Chinese communities, we conducted a community-based, cross-sectional study in 599 patients accounting for 48% of all stroke survivors registered in the 4 communities, who had suffered confirmed strokes and had undergone cognitive assessments via the Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), and Hachinski Ischemia Scale (HIS). Detection of PSCI was based on scores in these neuropsychological scales. Factors potentially impacting on occurrence of PSCI were explored by comparing demographic characteristics, stroke features, and cardiovascular risk factors between patients with and without PSCI. The overall prevalence of PSCI was 80.97% (95%CI: 77.82%-84.11%), while that of non-dementia PSCI (PSCI-ND) and post-stroke vascular dementia (PSD) was 48.91% (95%CI: 44.91%-52.92%) and 32.05% (95%CI: 28.32%-35.79%), respectively. Prior stroke and complications during the acute phase were independent risk factors for PSCI. The risk of recurrent stroke survivors having PSCI was 2.7 times higher than for first-episode survivors, and it was 3 times higher for those with complications during the acute phase than for those without. The higher prevalence of PSCI in this study compared with previous Chinese studies was possibly due to the combined effects of including rural stroke survivors, a longer period from stroke onset, and different assessment methods. There is an urgent need to recognize and prevent PSCI in stroke patients, especially those with recurrent stroke and complications during the acute phase.

Proportions of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus in patients with surgical site infections in mainland China: a systematic review and meta-analysis

BACKGROUND

Sufficient details have not been specified for the epidemiological characteristics of Staphylococcus aureus (S. aureus) and methicillin-resistant Staphylococcus aureus (MRSA) among surgical site infections (SSIs) in mainland China. This systematic review aimed to estimate proportions of S. aureus and MRSA in SSIs through available published studies.

METHODS

PubMed, Embase and four Chinese electronic databases were searched to identify relevant primary studies published between 2007 and 2012. Meta-analysis was conducted on the basis of logit-transformed metric for proportions of S. aureus and MRSA, followed by pre-defined subgroup meta-analysis. Random-effects meta-regression was also conducted to explore the impact of possible factors on S. aureus proportions.

RESULTS

106 studies were included, of which 38 studies involved MRSA. S. aureus accounted for 19.1% (95%CI 17.2-21.0%; I(2) = 84.1%) of all isolates in SSIs, which was roughly parallel to 18.5% in the United States (US) (P-value = 0.57) but significantly exceeded those calculated through the surveillance system in China (P-value<0.001). In subgroup analysis, S. aureus in patients with thoracic surgery (41.1%, 95%CI 26.3-57.7%; I(2) = 74.4%) was more common than in those with gynecologic surgery (20.1%, 95%CI 15.6-25.6%; I(2) = 33.0%) or abdominal surgery (13.8%, 95%CI 10.3-18.4%; I(2) = 70.0%). Similar results were found in meta-regression. MRSA accounted for 41.3% (95%CI 36.5-46.3%; I(2) = 64.6%) of S. aureus, significantly lower than that in the US (P-value = 0.001). MRSA was sensitive to vancomycin (522/522) and linezolid (93/94), while 79.9% (95%CI 67.4-88.4%; I(2) = 0%) and 92.0% (95%CI 80.2-97.0%; I(2) = 0%) of MRSA was resistant to clindamycin and erythromycin respectively.

CONCLUSION

The overall proportion of S. aureus among SSIs in China was similar to that in the US but seemed higher than those reported through the Chinese national surveillance system. Proportions of S. aureus SSIs may vary with different surgery types. Commonly seen in SSIs, MRSA tended to be highly sensitive to vancomycin and linezolid but mostly resistant to clindamycin and erythromycin.

The prevalence of hemophilia in mainland China: a systematic review and meta-analysis

The prevalence of hemophilia in mainland China was unclear; therefore, we can conducted a meta-analysis using existing data to evaluate the prevalence of hemophilia and its subtypes hemophilia A (HA), hemophilia B (HB), hemophilia C (HC) and Von Willebrand disease (VWD) in mainland China. We conducted a systematic literature review during August, 2011 using PubMed, EMBASE, and Cochrane Library in English and CBMDISK, CNKI, VIP and Wanfang Database in Chinese. We also carried out a search of general and specific hemophilia related websites. Reference lists of key reviews were hand-searched for further relevant research. Studies providing data of the prevalence of hemophilia or its subtypes were included. Meta-analysis was done using the generic inverse variance model. Twenty-two studies were included in the meta-analysis. The overall weighted prevalence of hemophilia was 3.6 per 100,000 and the prevalence among males was 5.5 per 100,000. The prevalence based on community studies was 2.9 per 100,000. The proportions of HA, HB, HC and VWD were 70.97%,16.13%,6.45% and 2.90%, respectively. The prevalences calculated in our study were higher than any previous studies in mainland China, but lower than the world-wide prevalences. The registration rate of hemophiliacs was extremely low. HA and HB were the major subtypes of hemophilia.

Effects of pulsed Nd:YAG laser on tensile bond strength and caries resistance of human enamel

This study aims to evaluate the effects of pulsed Nd:YAG laser on the tensile bond strength (TBS) of resin to human enamel and caries resistance of human enamel. A total of 201 human premolars were used in this in vitro study. A flat enamel surface greater than 4 × 4 mm in area was prepared on each specimen using a low-speed cutting machine under a water coolant. Twenty-one specimens were divided into seven groups for morphology observations with no treatment, 35% phosphoric acid etching (30 seconds), and laser irradiation (30 seconds) of pulsed Nd:YAG laser with five different laser-parameter combinations. Another 100 specimens were used for TBS testing. They were embedded in self-cured acrylic resin and randomly divided into 10 groups. After enamel surface pretreatments according to the group design, resin was applied. The TBS values were tested using a universal testing machine. The other 80 specimens were randomly divided into eight groups for acid resistance evaluation. Scanning electron microscope (SEM) results showed that the enamel surfaces treated with 1.5 W/20 Hz and 2.0 W/20 Hz showed more etching-like appearance than those with other laser-parameter combinations. The laser-parameter combinations of 1.5 W/15 Hz and 1.5 W/20 Hz were found to be efficient for the TBS test. The mean TBS value of 14.45 ± 1.67 MPa in the laser irradiated group was significantly higher than that in the untreated group (3.48 ± 0.35 MPa) but lower than that in the 35% phosphoric acid group (21.50 ± 3.02 MPa). The highest mean TBS value of 26.64 ± 5.22 MPa was identified in the combination group (laser irradiation and then acid etching). Acid resistance evaluation showed that the pulsed Nd:YAG laser was efficient in preventing enamel demineralization. The SEM results of the fractured enamel surfaces, resin/enamel interfaces, and demineralization depths were consistent with those of the TBS test and the acid resistance evaluation. Pulsed Nd:YAG laser as an enamel surface pretreatment method presents a potential clinical application, especially for the caries-susceptible population or individuals with recently bleached teeth.

Role of mitogen-activated protein kinase cascades in 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced apoptosis in neuronal pheochromocytoma cells

Mitogen-activated protein kinases (MAPKs) are involved in neuronal death caused by many cytotoxins. Conventional MAPKs consist of three family members: extracellular signal-regulated kinase-1/2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38. It has been originally shown that ERK1/2 is important for cell survival, whereas JNK and p38 are deemed stress responsive and thus involved in apoptosis. However, information describing the role of MAPKs in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced neurotoxicity is insufficient. The aim of this study was to identify the role of MAPK cascades in TCDD-induced neurotoxicity using differentiated pheochromocytoma (PC12) cells as a model for neuronal cells. Cell viability assay, terminal deoxynucleotidyl transferase dUTP nick-end labeling assay and flow cytometry analysis showed that TCDD attenuated cell viability with a dose- and time-dependent manner and significantly induced apoptosis in primary cortical neurons and PC12 cells. Western blot analysis indicated that TCDD markedly activated the expression of ERK1/2, JNK and p38 in TCDD-treated PC12 cells. Furthermore, PD98059 (ERK1/2 inhibitor), SP600125 (JNK inhibitor) and SB202190 (p38 inhibitor) notably blocked the effect of TCDD on cell apoptosis. Based on the findings above, it is concluded that the activation of MAPK signaling pathways may be associated with TCDD-mediated neuronal apoptosis.

In-silico prediction of blood-brain barrier permeability

The ability of penetration of the blood-brain barrier is one of the significant properties of a drug or drug-like compound for the central nervous system (CNS), which is commonly expressed by log BB (log BB = log (C (brain)/C (blood))). In this work, a dataset of 320 compounds with log BB values was split into a training set including 198 compounds and a test set including 122 compounds according to their structure properties by a Kohonen's self-organizing map (SOM). Each molecule was represented by global and shape descriptors, 2D autocorrelation descriptors and RDF descriptors calculated by ADRIANA.Code. Several quantitative models for prediction of log BB were built by a multilinear regression (MLR), a support vector machine (SVM) and an artificial neural network (ANN) analysis. The models show good prediction performance on the test set compounds.

A new approach for the identification of aphid vectors (Hemiptera: Aphididae) of potato virus Y

Potato virus Y (PVY) is one of the most economically important viruses affecting potato crops worldwide. PVY can be transmitted from potato to potato by several aphid species, most of which do not colonize the potato crop. New methods including preservation of viral RNA on stylets of aphids collected from yellow pan trap samples, polymerase chain reaction detection of PVY from the stylets of one aphid, and aphid identification using DNA barcoding were used to identify possible PVY vectors from field samples. In total, 65 aphid taxa were identified from the samples that tested positive for PVY. Among those, 45 taxa had never been evaluated for their ability to transmit PVY, and 7 were previously labeled as nonvectors. These results demonstrated that the list of PVY vectors is likely longer than previously reported and that most (if not all) species of aphids could be considered as potential vectors. This premise has important implications in the management of PVY in seed potato production.

Aphid feeding behavior in relation to potato virus Y (PVY) acquisition

Potato virus Y (PVY) is transmitted by aphids in a nonpersistent manner and aphid species differ in their ability to transmit PVY. During host selection, aphids will land and probe on nonhost plant species and this behavior is an important component of the epidemiology of many aphid-transmitted viruses. In this study, we hypothesized that host selection behavior varies between aphid species and the host or nonhost status of the plant and this behavior will modulate their ability to acquire PVY. Three potato colonizers, Myzus persicae (Sulzer), Macrosiphum euphorbiae (Thomas), and Aphis nasturtii (Kaltenbach) and three casual visitors to potato fields, Myzus cerasi (F.), Rhopalosiphum padi (L.), and Sitobion avenae (F.) were evaluated using two acquisition assays. In one assay, the normal host selection and feeding behavior of aphid species were eliminated using an artificial diet while the other considered the normal host selection and feeding behavior of aphid species on potato plants. PVY acquisition rates of aphid species widely differed between the two assays indicating the impact of host selection and feeding behavior on PVY acquisition. This behavior varied greatly between potato colonizers and noncolonizers. We recommend that laboratory evaluations of PVY vector efficiency consider the normal host selection and feeding behavior of aphid species on potatoes.

Association of KIR genotypes and haplotypes with syphilis in a Chinese Han population

Killer immunoglobulin-like receptors (KIRs) can regulate the activation of NK and T cells in response to infection. Syphilis is a sexually transmitted infection caused by the Treponema pallidum subspecies pallidum spirochete bacterium. The objective of this study was to explore whether KIR genotypes and haplotypes were associated with syphilis in a Chinese Han population. Polymerase chain reaction with sequence-specific primers (PCR-SSP) was used to identify the KIR genotypes in 190 patients with syphilis and 192 healthy controls. The frequency of genotype P was higher in healthy controls than that in patients with syphilis (P = 0.002), and its OR was 0.304, while the frequencies of genotypes AE and AG were higher in patients with syphilis than those in healthy controls. The frequency of haplotype 17 was lower, and its OR was 0.321, whereas the frequencies of haplotype 1 and 6 were higher in patients with syphilis than those in healthy controls. KIR haplotypes A and B have distinctive centromeric (Cen) and telomeric (Tel) gene content motifs. The frequency of Tel-B/B was higher in patients with syphilis than that in healthy controls (P = 0.024). Based on these findings, it seems that individuals with the genotype AE, AG or Tel-B/B, or haplotypes 1 and 6 are susceptible to syphilis, whereas individuals with genotype P or haplotype 17 are protective from syphilis in the Chinese Han population.

SU-E-J-202: Treatment Dose Assessment with the Consideration of Radiation Dose Inducible Organ Shrinkage/Deformation

PURPOSE

For asymmetric organ shrinkage caused by heterogeneity dose distribution, tissue elasticity based deformable organ registration cannot be directly applied to the treatment image to construct the treatment dose. A novel approach is proposed to include radiation dose inducible organ shrinkage/deformation in the consideration of treatment dose assessment.

METHODS

A model and algorithm were developed to include dose inducible organ shrinkage in the deformable image registration. In the model, we assume that the logarithm of tissue-element volume shrinkage ratio is proportional to the LQ survival function, and the tissue-element displacement field is the gradient of a scalar potential function. The derived Poisson equation of the potential was solved using a finite element method. Two steps registration was implemented to determine the tissue-element volume and displacement. The first is the conventional deformable image registration to determine the organ surface. The second is to map the element volume/position in the shrinking organ with using the dose inducible shrinkage model. Treatment dose was constructed by applying both the conventional deformable registration and the shrinkage model on CBCT images obtained from h&n treatment. The dose distribution in the patient parotid was evaluated.

RESULTS

Treatment dose-volume, V30, constructed including the dose inducible parotid shrinkage was 11% higher than the one from the conventional deformable image registration and dose construction. Tissue elements in the high dose region shrink more than those in a low dose region which results in extra tissue elements in the organ move into the high dose area during the treatment course and an unfavorable dose-volume relationship in the organ.

CONCLUSIONS

Without including dose inducible organ shrinkage, treatment dose in a shrinking organ could be underestimated. On the other hand, including this effect in the treatment evaluation and adaptive planning optimization will minimize the potential detriment of the effect.

Inertia effects on characterization of dynamic response of brain tissue

Modeling and simulation of traumatic brain injury (TBI) resulted from collision or blast loading requires characterization of mechanical response over a wide range of loading rates under valid testing conditions. In this study, mechanical response of fresh bovine brain tissue was studied using the two modified Kolsky bar techniques. Radial deformation behavior of annular specimens, which are typically used to characterize the dynamic uniaxial compressive response of biological tissues, was examined using a modified Kolsky bar and a high speed camera to collect images while the specimen deforms at an axial strain rate of 2000s(-1). The high-speed images revealed inhomogeneous specimen deformation possibly brought about by radial inertia and causing a multi-axial stress state. To acquire valid stress-strain results that can be used to produce constitutive behavior of the soft materials, a novel torsion technique was developed to obtain pure shear response at dynamic loading rates. Experimental results show clear differences in the material response using the two methods. These results indicate that the previously demonstrated annular specimen geometry aimed at reducing inertia induced stress components for high rate soft materials uniaxial-compressive testing may still possess a significant component of radial inertia induced radial stress which consequently caused the observed inhomogeneous deformation in brain tissue test samples.

Diagnosis and surgical treatment of carotid body tumors: 25 years' experience in China

Carotid body tumors (CBT) are rare neoplasms arising from the small chemoreceptor organ in the adventitia of the common carotid bifurcation. A retrospective survey was conducted in 33 patients, treated by curative resection of the neoplasm, from 1980 to 2005, to investigate clinical features, preoperative treatment and surgical approach, and determine the optimum management for CBT. The demographic characteristics, clinical features, surgical approach and complications were documented and analyzed. Accurate diagnosis and effective preoperative training were associated with a good surgical outcome. Carotid arteriography accurately diagnoses and evaluates the brain's collateral circulation in the circle of Willis. Ultrasonography is useful. Carotid blood flow obstruction (Matas' training) is effective. Complete excision of the carotid system without a vascular replacement is possible only after reliable Matas' training and objective observation of the establishment of circulation in the circle of Willis. Correct treatment of the internal and common carotid artery is important to reduce postoperative complications. The continuity of the common and internal carotid artery should be retained if possible, and carotid artery repair is recommended. Minor complications occurred in five (15%) patients and one patient died from a cause not related to the CBT at follow-up.

A novel HLA-B*40 allele, B*4086, was identified by sequence-based typing in a Chinese donor

We report the identification of a novel HLA-B*40 allele, B*4086, which was detected during our routine sequence-specific oligonucleotide (SSO) HLA typing of a sample from a bone marrow donor and confirmed with sequence-based typing. The name HLA-B*4086 was officially assigned by the WHO Nomenclature Committee in February 2008.

Behavior of bird cherry-oat aphid and green peach aphid in relation to potato virus Y transmission

Potato virus Y is transmitted to potato in a nonpersistent manner by many aphid species, some of which do not colonize this crop. The behavior of bird cherry-oat aphid, Rhopalosiphum padi (L.) on potato, Solanum tuberosum L., a plant species that is not colonized by this aphid, was described and compared with that of the potato-colonizing green peach aphid, Myzuspersicae (Sulzer). A higher proportion of winged morph of R. padi than M. persicae left the plant, but aphids that stayed in contact with the plant took the same mean time to initiate the first probe and it lasted the same mean time compared with M. persicae. Electronic penetration graph technique was used to study the probing behavior of the aphids during Potato virus Y (family Potyviridae, genus Potyvirus, PVY) transmission tests. Transmission rate decreased from 29 to 8% when the acquisition time increased from 5 min of continuous probing to 1 h with M. persicae, but it remained low (2 and 1%) with R. padi. Most of the difference in transmission rate between acquisition time with M. persicae and between aphid species was related to the change in the time and behavior taking place between the last cell puncture of the acquisition phase to the first cell puncture of the inoculation phase. Results presented here clearly demonstrated the importance of host plant selection and probing behavior in the transmission of nonpersistent plant viruses. They also stress the need to consider the behavior of the aphid in the design of laboratory tests of virus vector efficacy.

Successful application of tissue-engineered skin to refractory ulcers

In this study, the effectiveness of a tissue-engineered skin (Activskin; Aierfu, Xi'an, China) was evaluated for the treatment of various refractory ulcers. These ulcers were treated with Activskin after debridement and irrigation with saline. A second application of Activskin was essential if the first application failed to persist on the wounds. Clinical efficacy and safety were assessed at regular clinic visits during 6 months of follow-up. All 11 treated patients improved with Activskin. The ulcers healed by inward migration from the wound edge. The average healing time was 27.8 days. No recurrent ulceration or other adverse events were observed during follow-up. These results provide preliminary evidence that Activskin is safe and effective in the management of refractory ulcers.

Improvement of peripheral nerve regeneration by a tissue-engineered nerve filled with ectomesenchymal stem cells

Ectomesenchymal stem cells (EMSCs) originate from the cranial neural crest. They are a potential source of neuronal and Schwann cells (SCs) of the peripheral nervous system (PNS) during embryonic development. The third passage of EMSCs enzymatically isolated from the mandibular processes of Sprague-Dawley rats were cultured in forskolin and bovine pituitary extract for 6 days to generate functional Schwann cell phenotypes. Next, 10-mm defects in the sciatic nerves were bridged with an autograft, tissue-engineered nerve filled with differentiated cells in collagen, or a PLGA conduit alone in 18 rats, and the nerve defects of another four rats were left untreated. The regenerated nerves were evaluated by the sciatic functional index (SFI) monthly and by histological analysis 4 months after grafting. The recovery index of the sciatic nerve improved significantly in the autograft and tissue-engineered nerve groups, both of which were superior to the PLGA group. In animals transplanted with the EMSCs, there was greater regeneration than with conduit alone during the same period of implantation. These results show that when EMSCs are transplanted to a peripheral nerve defect they differentiate into supportive cells that contribute to the promotion of axonal regeneration.

FGF signalling in craniofacial development and developmental disorders

The Fgf signalling pathway is highly conserved in evolution and plays crucial roles in development. In the craniofacial region, it is involved in almost all structure development from early patterning to growth regulation. In craniofacial skeletogenesis, the Fgf signal pathway plays important roles in suture and synchondrosis regulation. Mutations of FGF receptors relate to syndromatic and non-syndromatic craniosynostosis. The Fgf10/Fgfr2b signal loop is critical for palatogenesis and submandibular gland formation. Perturbation of the Fgf signal is a possible mechanism of palatal cleft. Fgf10 haploinsufficiency has been identified as the cause of autosomal dominant aplasia of lacrimal and salivary glands. The Fgf signal is also a key regulator of tooth formation: in the absence of Fgfr2b tooth development is arrested at the bud stage. Fgfr4 has recently been identified as the key signal mediator in myogenesis. In this review, these aspects are discussed in detail with a focus on the most recent advances.

The genome of the social amoeba Dictyostelium discoideum

The social amoebae are exceptional in their ability to alternate between unicellular and multicellular forms. Here we describe the genome of the best-studied member of this group, Dictyostelium discoideum. The gene-dense chromosomes of this organism encode approximately 12,500 predicted proteins, a high proportion of which have long, repetitive amino acid tracts. There are many genes for polyketide synthases and ABC transporters, suggesting an extensive secondary metabolism for producing and exporting small molecules. The genome is rich in complex repeats, one class of which is clustered and may serve as centromeres. Partial copies of the extrachromosomal ribosomal DNA (rDNA) element are found at the ends of each chromosome, suggesting a novel telomere structure and the use of a common mechanism to maintain both the rDNA and chromosomal termini. A proteome-based phylogeny shows that the amoebozoa diverged from the animal-fungal lineage after the plant-animal split, but Dictyostelium seems to have retained more of the diversity of the ancestral genome than have plants, animals or fungi.

Multilineage differentiation of ectomesenchymal cells isolated from the first branchial arch

Cranial neural crest-derived ectomesenchymal cells may be pluripotent stem cells that are capable of generating a range of phenotypes. The fate of these cells appears to be determined in part by intrinsic genetic programs and also by the influence of extracellular signals in the local environment. The extent of lineage determination once neural crest cells have migrated to the first branchial arch is not clear, although branchial arch pattern is not thought to be the result of crest predetermination. The aim of the present study was to test the hypothesis that ectomesenchymal cells of the first branchial arch show properties of pluripotent stem cells, the lineage of which may be directed by specific molecular signaling. Ectomesenchymal cells were enzymatically isolated from the mandibular processes of BALB/c mice and maintained in an undifferentiated state while cultured with leukemia inhibitory factor or induced to differentiate by lineage-specific induction factors or growth conditions, including transforming growth factor beta, forskolin, and a mineralization-promoting medium. Morphological observations and immunocytochemistry demonstrated that cells could be induced to differentiate into smooth muscle cells, glial cells, and osteoblasts, respectively. In the presence of the mineralization-promoting medium, alkaline phosphatase activity increased significantly and mineralization nodules formed. The data reported support the concept that many, although not all, first branchial arch-derived ectomesenchymal cells show properties of multipotent stem cells, the subsequent fate of which can be influenced by induction factors and growth conditions. Some cells, however, showed a degree of commitment with respect to their fate. The possible application of first branchial arch-derived stem cells to tissue engineering of the orofacial tissues should involve consideration of the developmental stage of cell harvesting and the desired cell fate.

Diversity Among Potato virus Y Isolates Obtained from Potatoes Grown in the United States

ABSTRACT Potato field isolates (Solanum tuberosum) of Potato virus Y (PVY) collected from the midwestern and western United States were characterized using serological, molecular, and biological assays. PVY field isolates were grouped into the previously defined categories: PVY(O), European PVY(NTN), North American PVY(NTN), and PVY(N:O) recombinant and four previously undefined groups. Studies reported here agree with published reports from Europe and elsewhere in North America as PVY isolates capable of causing veinal necrosis in tobacco indicator plants appear in high frequency. In contrast to European experiences, PVY tuber necrosis isolates have a PVY(O) coat protein rather than that of PVY(N). Several PVY(N:O) recombinant isolates induced potato tuber necrotic ringspot disease (PTNRD) in the highly susceptible potato cv. Yukon Gold. The PTNRD symptoms produced by these PVY(N:O) recombinants were atypical compared with lesions found on the same cultivar infected with either the European or North American PVY(NTN) isolates. These PVY(N:O) isolates produced a roughly circular, sunken necrotic lesion on the surface of the tuber instead of the typical external sunken ring pattern displayed by PVY(NTN) isolates. This study establishes the complex nature of PVY populations within the U.S. potato industry and clearly demonstrates the diverse nature of PVY in the United States.

A model system of primary murine hepatocytes infected by murine cytomegalovirus

In order to establish a model system of the murine hepatocyte infection by murine cytomegalovirus (MCMV), the primary cultured murine hepatocytes were obtained in a modified low-serum medium system by a non-perfusion method, and then infected by Smith strain MCMV. Infected hepatocytes showed characteristic cytopathic effect (CPE) at 30 h after infection, in which a large number of viral particles was found and ultrastructures were destroyed (as revealed by disappearance of bile canalicula and organelles) under the electron microscope and MCMV immediate-early genes were detected by in situ hybridization. Meanwhile, infected cells produced albumin significantly less than corresponding uninfected controls. On the contrary, uninfected controls simultaneously cultured under the same conditions showed normal function and ultrastructure (glycogen rosettes, bile canalicula, wheel-like mitochondria and well-developed rough and smooth endoplasmic reticula). These results demonstrated that a model system of primary cultured murine hepatocytes infected by MCMV was successfully set up.

The clinical study and HLA genotyping of 112 familial myasthenia gravis patients

One hundred and twelve cases of familial myasthenia gravis (MG) from 44 families selected from 2100 patients with MG diagnosed since 1983 in the Department of Neurology were studied. The clinical pictures and immunological features of the patients showed a great resemblance to those of sporadic cases. The pedigree analysis disclosed that the hereditary patterns of familial patients were basically Mendellian autosomal inheritance. Many predisposing factors such as fever, infection, use of aminoglycoside or vaccines, played an important role in presenting the phenotype of subclinical cases. The HLA genotyping suggested that the complement polymorphism C4A * 4, the complotype S42, and the genes 0901 and 1301 of DRB1 allele, were related to the pathogenesis of MG. It was concluded that the phenotype of MG may be the result of interaction between hereditary defects and environmental factors.

Possible Escape of a Recombinant Isolate of Potato virus Y by Serological Indexing and Methods of its Detection

Surveys of commercial and seed potato fields for virus diseases (1998 to 2002) in Manitoba established that Potato virus Y (PVY) is of concern in seed potato production. To determine the prevalence of PVY strains, PVY-infected tubers identified by reverse transcription-polymerase chain reaction (RT-PCR) from surveys (2000 to 2001) were grown for symptom expression and strain characterization by strain-specific RT-PCR, bioassays, and serological assays. Of the samples collected (2000 to 2001) and tested by RT-PCR, 4.0% contained PVY. Further analysis of the PVY-positive samples by a duplex RT-PCR facilitating the simultaneous detection of common (PVY^O) and tobacco veinal necrosis strains (PVY^N/NTN) indicated that 37.5% contained PVY^O and 63.5% contained PVY^N-type isolates. Analysis of the PVY^N-type samples using three monoclonal antibodies (MAbs) showed that all reacted with only the PVY^O MAbs and not with the PVY^N-specific MAb. Partial nucleotide sequences of both ends of PVY-RNA showed that the PVY^N-type isolates resembled those reported in 1996 from Manitoba. These isolates are designated as PVY^N:O. In view of the increased incidence of PVY^N:O in one production area, seed tubers imported from other provinces of Canada and the neighboring United States were analyzed for PVY^N:O. The PVY^N:O was detected in imported seeds from Minnesota, Montana, and North Dakota.

Magnetization-direction-dependent local electronic structure probed by scanning tunneling spectroscopy

Scanning tunneling spectroscopy (STS) of thin Fe films on W(110) shows that the electronic structure of domains and domain walls is different. This experimental result is explained on the basis of first-principles calculations. A detailed analysis reveals that the spin-orbit induced mixing between minority d(xy+xz) and minority d(z(2)) spin states depends on the magnetization direction and changes the local density of states in the vacuum detectable by STS. As a consequence nanometer-scale magnetic structure information is obtained even by using nonmagnetic probe tips.

Sodium sulphite inhibition of potato and cherry polyphenolics in nucleic acid extraction for virus detection by RT-PCR

Phenolic compounds from plant tissues inhibit reverse transcription-polymerase chain reaction (RT-PCR). Multiple-step protocols using several additives to inhibit polyphenolic compounds during nucleic acid extraction are common, but time consuming and laborious. The current research highlights that the inclusion of 0.65 to 0.70% of sodium sulphite in the extraction buffer minimizes the pigmentation of nucleic acid extracts and improves the RT-PCR detection of Potato virus Y (PVY) and Potato leafroll virus (PLRV) in potato (Solanum tuberosum) tubers and Prune dwarf virus (PDV) and Prunus necrotic ringspot virus (PNRSV) in leaves and bark in the sweet cherry (Prunus avium) tree. Substituting sodium sulphite in the nucleic acid extraction buffer eliminated the use of proteinase K during extraction. Reagents phosphate buffered saline (PBS)-Tween 20 and polyvinylpyrrolidone (PVP) were also no longer required during RT or PCR phase. The resultant nucleic acid extracts were suitable for both duplex and multiplex RT-PCR. This simple and less expensive nucleic acid extraction protocol has proved very effective for potato cv. Russet Norkotah, which contains a high amount of polyphenolics. Comparing commercially available RNA extraction kits (Catrimox and RNeasy), the sodium sulphite based extraction protocol yielded two to three times higher amounts of RNA, while maintaining comparable virus detection by RT-PCR. The sodium sulphite based extraction protocol was equally effective in potato tubers, and in leaves and bark from the cherry tree.

Effects of solution pH and electrical parameters on hydroxyapatite coatings deposited by a plasma-assisted electrophoresis technique

Hydroxyapatite (HA) coatings can be deposited using a hybrid process of plasma electrolysis and electrophoresis, called plasma-assisted electrophoretic deposition (PEPD). HA aqueous suspensions with various pH values were prepared using a modified ultrasonic cleaning bath as an agitator/stirrer. Both DC and unbalanced AC power supplies were used to bias the titanium alloy substrate materials employed in this work. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to observe and analyze coating morphology and microstructure. It was shown that the morphology and composition of the calcium phosphate coatings were significantly influenced by solution pH values; the level of "pure" HA in the coatings' composition corresponded to both solution pH and the type of power supply employed. Loss of hydroxyl radials (i.e., dehydroxylation), which degrades the performance of the hydroxyapatite coating in terms of long-term chemical and mechanical stability, can be virtually eliminated by a combination of high pH and unbalanced AC plasma power. In addition, the underlying TiO2 coatings used to support the HA layer (preproduced by plasma electrolysis process) have a nanoscaled (10-20 nm) polycrystalline structure. TEM studies also revealed a dense, continuous amorphous titania layer (10 nm in thickness) at the interface between the Ti alloy substrate and the TiO2 layer, which may play a role in improving the corrosion resistance of the substrate. Such a nanophase TiO2 layer (if used as a coating alone) may also provide a further improvement in osteoinductive properties, compared to a conventional TiO2 coating on the Ti alloy substrate.

Effects of solution pH and electrical parameters on hydroxyapatite coatings deposited by a plasma-assisted electrophoresis technique

Hydroxyapatite (HA) coatings can be deposited using a hybrid process of plasma electrolysis and electrophoresis, called plasma-assisted electrophoretic deposition (PEPD). HA aqueous suspensions with various pH values were prepared using a modified ultrasonic cleaning bath as an agitator/stirrer. Both DC and unbalanced AC power supplies were used to bias the titanium alloy substrate materials employed in this work. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to observe and analyze coating morphology and microstructure. It was shown that the morphology and composition of the calcium phosphate coatings were significantly influenced by solution pH values; the level of "pure" HA in the coatings' composition corresponded to both solution pH and the type of power supply employed. Loss of hydroxyl radials (i.e., dehydroxylation), which degrades the performance of the hydroxyapatite coating in terms of long-term chemical and mechanical stability, can be virtually eliminated by a combination of high pH and unbalanced AC plasma power. In addition, the underlying TiO2 coatings used to support the HA layer (preproduced by plasma electrolysis process) have a nanoscaled (10-20 nm) polycrystalline structure. TEM studies also revealed a dense, continuous amorphous titania layer (10 nm in thickness) at the interface between the Ti alloy substrate and the TiO2 layer, which may play a role in improving the corrosion resistance of the substrate. Such a nanophase TiO2 layer (if used as a coating alone) may also provide a further improvement in osteoinductive properties, compared to a conventional TiO2 coating on the Ti alloy substrate.

Structure and functionality of a designed p53 dimer

P53 is a homotetrameric tumor suppressor protein involved in transcriptional control of genes that regulate cell proliferation and death. In order to probe the role that oligomerization plays in this capacity, we have previously designed and characterized a series of p53 proteins with altered oligomeric states through hydrophilc substitution of residues Met340 or Leu344 in the normally tetrameric oligomerization domain. Although such mutations have little effect on the overall secondary structural content of the oligomerization domain, both solubility and the resistance to thermal denaturation are substantially reduced relative to that of the wild-type domain. Here, we report the design and characterization of a double-mutant p53 with alterations of residues at positions Met340 and Leu344. The double-mutations Met340Glu/Leu344Lys and Met340Gln/Leu344Arg resulted in distinct dimeric forms of the protein. Furthermore, we have verified by NMR structure determination that the double-mutant Met340Gln/Leu344Arg is essentially a "half-tetramer". Analysis of the in vivo activities of full-length p53 oligomeric mutants reveals that while cell-cycle arrest requires tetrameric p53, transcriptional transactivation activity of monomers and dimers retain roughly background and half of the wild-type activity, respectively.

Effects of morphine on rheological properties of rat red blood cells

To evaluate the effect of morphine on red blood cells, in vivo and in vitro rat models of morphine dependence were established. Rheological properties of rat red cells were measured by ektacytometry; the biophysical changes in the membrane of rat red cells were measured by the Fourier-Transformed Infrared technique (FT-IR) and the fluorescence depolarization method. The results show that the membrane fluidity of red cells was greatly reduced by morphine and the secondary structure of membrane proteins was changed. This suggests that morphine affects the rat red cell membrane directly, rather than through opioids-receptors.

[Study on polymorphism of D gene exons among RhD-negative Chinese Han population]

OBJECTIVE

To explore the genomic structure of 8 exons in D gene of RhD(-) Chinese Han population.

METHODS

Polymerase chain reaction-sequence specific primers(PCR-SSP) were used to study genomic DNA from 50 samples of RhD(-) Chinese Han donors. Exons 2, 3, 4, 5, 6, 7, 9, 10 of RHD gene and exons 1, 2, 4, 5 of RHCE gene were specifically amplified, also intron 4 of them was amplified.

RESULTS

Phenotypes of the 50 RhD(-) donors were: 22 ccdee, 22 Ccdee, 3 CcdEe, 3 CcdEe. The 8 exons of RHD gene were completely absent in 25 donors with ccdee or ccdEe phenotype, while polymorphisms of D gene exons were found in 25 donors with Ccdee or CcdEe phenotype: the presence of all 8 exons of D gene in 9 donors, the absence of the 8 exons in 7 donors, the presence of exon 2 in 5 donors, the presence of exon 6 in 3 donors and the presence of exons 2, 6, 10 in 1 donor were demonstrated.

CONCLUSION

Polymorphisms of RHD gene exons were present among RhD(-) Chinese Han blood donors. The 8 exons of RHD gene were completely absent in donors with Rhesus cc phenotype, while 5 polymorphisms of RHD gene exons were found in donors with Rhesus Cc phenotype. The discrepancy of the RHD gene in RhD(-) individuals between Chinese Hans and Caucasians indicates that care should be exercised by clinicians in the use of the RhD genotyping results.

Differential Accumulation of Potato virus A and Expression of Pathogenesis-Related Genes in Resistant Potato cv. Shepody upon Graft Inoculation

ABSTRACT Potato (Solanum tuberosum L.) cv. Shepody is highly resistant to Potato virus A (PVA), yielding no visible symptoms after rub inoculation. In 'Shepody' rootstocks graft-inoculated by PVA-infected scions from a susceptible host, we found a resistance consisting of traces of necrosis (necrotic streaks) in stems and chlorosis in newly emerged leaves. The response was temperature dependent, appearing at 15 to 18 degrees C but not at 28 to 31 degrees C. Necrosis was also observed in tubers, appearing first in the bud end and spreading randomly throughout the majority of the tuber. Trace amounts of PVA in plant tissues were detected by a combination of reverse transcription polymerase chain reaction and Southern blot procedures. The virus concentration was significantly higher in visibly necrotic areas than in nonnecrotic areas, suggesting that presence of the necrosis may be concentration dependent. Pathogenesis-related gene expression showed that chitinase A and B, glucanase B, and PR-10a were associated with chlorotic or necrotic symptoms in leaves, stems, and tubers. Gene expression was markedly more evident in tuber tissues than in leaves and stems. Furthermore, generation of oxidants was also observed within the necrotic areas. Although PVA was detected in necrotic areas of tubers, newly emerged plants from the same tubers were PVA-free.

A novel usage of random primers for multiplex RT-PCR detection of virus and viroid in aphids, leaves, and tubers

A multiplex reverse transcription polymerase chain reaction (m-RT-PCR) was developed for the simultaneous detection of five potato viruses and a viroid. The synthesis of cDNAs used for amplification was primed by hexanucleotides (random primers, RP). An RNA extraction procedure employing DNase I, is routinely used to isolate potato viruses and viroid (Potato virus S, PVS; Potato leafroll virus, PLRV; Potato virus X, PVX; Potato virus A and Y, PVA, PVY; and Potato spindle tuber viroid, PSTVd) from infected tissues. This extraction method produced deoxy-oligonucleotides, which in turn were used to prime the reverse transcription of RNA templates of all the viruses and the viroid. A time-course study from 15 s to 30 min showed optimal oligonucleotide generation by DNase I occurred at 10 min, an incubation time already incorporated in the extraction protocol. The presence of oligonucleotides capable of priming cDNA synthesis was also demonstrated in RNA preparations from aphids, leaves, and tubers. In order to duplicate the priming of templates by oligonucleotides, commercially available hexanucleotides were used as RP. When fragments were amplified from 5'- and 3'-ends of the random primed cDNA of PVY genome, bands of similar intensity were observed. In contrast, when two fragments (short and long) from the P1 gene region of the PVA genome were amplified, the yield of the short fragment was significantly higher in intensity than that of the long fragment in random primed cDNA. Irrespective of the origin of the primers (generated during extraction vs. commercially purchased), single or multiple viruses or the viroid were detected by amplification of random primed cDNAs present individually in the reaction or in a cDNA pool consisting of five viruses and the viroid. The cDNA produced by RP or virus specific primers (SP) was used to detect PLRV and PVY from infected tubers in a duplex reverse transcription polymerase chain reaction (d-RT-PCR). The RP cDNA gave increased detection. Comparison of RP primed cDNAs from dormant or sprouted tubers and leaves showed that for some cultivars, such as 'Shepody', leaves were more reliable for PVY and PLRV detection than the tubers, in both the d- and m-RT-PCR.

A meanfield approach to the thermodynamics of a protein-solvent system with application to the oligomerization of the tumor suppressor p53

The thermodynamic stability and oligomerization status of the tumor suppressor p53 tetramerization domain have been studied experimentally and theoretically. A series of hydrophilic mutations at Met-340 and Leu-344 of human p53 were designed to disrupt the hydrophobic dimer-dimer interface of the tetrameric oligomerization domain of p53 (residues 325-355). Meanfield calculations of the free energy of the solvated mutants as a function of interdimer distance were compared with experimental data on the thermal stability and oligomeric state (tetramer, dimer, or equilibrium mixture of both) of each mutant. The calculations predicted a decreasing stability and oligomeric state for the following amino acids at residue 340: Met (tetramer) > Ser Asp, His, Gln, > Glu, Lys (dimer), whereas the experimental results showed the following order: Met (tetramer) > Ser > Gln > His, Lys > Asp, Glu (dimers). For residue 344, the calculated trend was Leu (tetramer) > Ala > Arg, Gln, Lys (dimer), and the experimental trend was Leu (tetramer) > Ala, Arg, Gln, Lys (dimer). The discrepancy for the lysine side chain at residue 340 is attributed to the dual nature of lysine, both hydrophobic and charged. The incorrect prediction of stability of the mutant with Asp at residue 340 is attributed to the fact that within the meanfield approach, we use the wild-type backbone configuration for all mutants, but low melting temperatures suggest a softening of the alpha-helices at the dimer-dimer interface. Overall, this initial application of meanfield theory toward a protein-solvent system is encouraging for the application of the theoretical model to more complex systems.

Real-space imaging of two-dimensional antiferromagnetism on the atomic scale

A two-dimensional antiferromagnetic structure within a pseudomorphic monolayer film of chemically identical manganese atoms on tungsten(110) was observed with atomic resolution by spin-polarized scanning tunneling microscopy at 16 kelvin. A magnetic superstructure changes the translational symmetry of the surface lattice with respect to the chemical unit cell. It is shown, with the aid of first-principles calculations, that as a result of this, spin-polarized tunneling electrons give rise to an image corresponding to the magnetic superstructure and not to the chemical unit cell. These investigations demonstrate a powerful technique for the understanding of complicated magnetic configurations of nanomagnets and thin films engineered from ferromagnetic and antiferromagnetic materials used for magnetoelectronics.

Detection of multiple potato viruses using an oligo(dT) as a common cDNA primer in multiplex RT-PCR

A novel usage of multiplex reverse transcription polymerase chain reaction (m-RT-PCR) for simultaneous detection of multiple viruses is reported. By use of an oligo(dT), as a common primer, nearly full-length cDNAs can be synthesized. Furthermore, combining an oligo(dT) primer with a specific antisense primer can be used to simultaneously prime reverse transcription of both polyadenylated and non-polyadenylated RNAs. Four viral genera including five potato viruses [(carlavirus (PVS), polerovirus (PLRV), potexvirus (PVX), potyvirus (PVA and PVY))] and a viroid genus including a viroid genome (pospiviroid (PSTVd)) were used to develop various formats of m-RT-PCR. In artificially created viral RNA mixtures, all six RNA pathogens were detected successfully by uniplex- and m-RT-PCR. In naturally infected field grown tubers, m-RT-PCR detected infection of two to three viruses, which were present in the tubers.