Research of thoracolumbar spine lateral vascular anatomy and imaging

This study introduces an anatomical basis for surgeries such as thoracoscope-assisted thoracolumbar spinal anterior interbody fusion in terms of image observing and corpse specimen anatomising. The observation of the 3-dimensional computed tomography (CT) image indicates that segmental arteries are visible and run in the central supersulcus of the corresponding vertebral body's side, while the branches are invisible. The distances between adjacent segmental arteries in T(10/11), T(11/12), T₁₂/L₁, L(1/2), and L(2/3) are 23.35 ± 1.48, 25.61 ± 2.08, 29.12 ± 2.30, 32.53 ± 2.18, and 33.73 ± 2.29 (mm), respectively. And the observation by the thoracolumbar spine side of the adult corpse specimens shows that segmental arteries and veins constantly exist and run in the central supersulcus of the corresponding vertebral body's side; each segmental artery has some small branches; the zone between the upper and lower segmental arteries form a relatively non-vascular nerve safe zone, where the intervertebral space (disc) locates. The distances between adjacent segmental arteries in T(10/11), T(11/12), T₁₂/L₁, L(1/2), L(2/3) are 23.34 ± 0.78, 25.54 ± 0.85, 29.11 ± 1.01, 32.82 ± ± 1.28, and 33.71 ± 1.42 (mm), respectively. The safe zone, with the intervertebral disc as the reference mark, can provide enough operation space for surgeries like thoracoscope-assisted anterior interbody fusion and reducing damage to blood vessels as well as surgical complications. Additionally, the arrangement and distribution of segmental arteries can be clearly displayed on the 3-dimensional CT image and the result is basically consistent with that of corpse specimens. Therefore, the 3-dimensional CT image can be regarded as the reference for video-assisted thoracoscopic surgery plans.

Lentivirus-mediated expression of MxA in chicken spermatogonial stem cells

The aim of this study was to construct a lentivirus vector that carries the human myxovirus-resistant A (MxA) anti-virus gene for efficiently infecting rooster spermatogonial stem cells (SSCs). A lentiviral vector carrying the enhanced green fluorescent protein (EGFP) and MxA fusion gene (EGFP-MxA) was constructed using TOPO technology in this study. Enhanced green fluorescent protein-MxA was inserted in the right orientation as determined by restriction enzyme digest. No gene recombination in the vector occurred. After infecting 293FT cells, EGFP-MxA fusion protein was expressed as granular green fluorescence characteristic of EGFP-MxA expression, suggesting that the TOPO expression vector was properly constructed and the fusion protein expressed correctly. The EGFP-MxA recombinant lentivirus was packaged by cotransfecting 293FT cells with EGFP-MxA and the packaging plasmids. We also purified SSCs from testicle tissues from 25-day-old roosters for infection with the EGFP-MxA recombinant virus. After infecting rooster SSCs with the recombinant virus for 72 h, EGFP-MxA expression was detected by EGFP expression. Enhanced green fluorescent protein-MxA expression in SSCs was further confirmed at the transcription level by RT-PCR and at the protein level by immunocytochemistry. Staining with Hoechst 33342 showed that infected SSCs differed from the sertoli cells. Similar to stem cells, SSCs were positive for alkaline phosphoric acid enzyme and for stage-specific embryonic antigen-1 stem cell factor. The results demonstrated that the recombinant virus made in our study can infect rooster SSCs efficiently to express the anti-virus protein MxA, establishing the basis of transferring MxA into SSCs to obtain virus-resistant, genetically-modified roosters.

Sonographic value in diagnosis of hemorrhagic ovarian cysts

PURPOSE

To investigate the sonographic characteristics of hemorrhagic ovarian cysts (HOC) and to avoid unnecessary surgery.

METHODS

113 cases of suspected HOC underwent sonographic and clinical follow-up for three months.

RESULTS

104 cases were clinically diagnosed with HOC as the masses disappeared naturally. The mean length of the greatest diameter was 5.12 +/- 1.33 cm, and the mean period of disappearance was 3.5 +/- 2.4 weeks. There were four patterns of the image: 21 cases (20.2%) showed a diffused dense echo pattern, 25 cases (24.0%) displayed a mixed pattern, 30 cases (28.8%) expressed a sponge-like pattern and 28 cases (27.0%) exhibited a cystic pattern. Ring blood flow with high velocity and low resistance was detected in 41 cases (40%) and there was no internal blood flow.

CONCLUSION

HOC showed characteristic features on sonography, which provided useful information to differentiate HOC from ovarian tumors.

Use of Ligasure™ Bipolar Diathermy System in vaginal hysterectomy

The use of Ligasure, a computer-controlled bipolar diathermy system is proven beneficial in a wide range of surgical procedures. This study was to evaluate its application to vaginal hysterectomy. Over forty patients underwent vaginal hysterectomy with (n = 32) or without (n = 12) Ligasure using standard surgical techniques. The main diagnoses, the age of patients, time for surgery, hospital stay and estimated blood loss during operation were compared. The average operating time was shorter in the Ligasure vaginal hysterectomy group (30 mins (24-48) P < 0.05), the estimated blood loss was less in the Ligasure hysterectomy group (39 mins (25-60) P < 0.05), and the hospital stay was shorter in the Ligasure hysterectomy group (1.2 days (1-2) vs 3 days (3-5) P < 0.05). There were no postoperative complications or re-admissions in either group. Vaginal hysterectomy using Ligasure reduced operating time and blood loss, and therefore shortened hospital stay.

Immune modulation by adjuvants combined with diphtheria toxoid administered topically in BALB/c mice after microneedle array pretreatment

Purpose

In this study, modulation of the immune response against diphtheria toxoid (DT) by various adjuvants in transcutaneous immunization (TCI) with microneedle array pretreatment was investigated.

Methods

TCI was performed on BALB/c mice with or without microneedle array pretreatment using DT as a model antigen co-administrated with lipopolysaccharide (LPS), Quil A, CpG oligo deoxynucleotide (CpG) or cholera toxin (CT) as adjuvant. The immunogenicity was evaluated by measuring serum IgG subtype titers and neutralizing antibody titers.

Results

TCI with microneedle array pretreatment resulted in a 1,000-fold increase of DT-specific serum IgG levels as compared to TCI. The immune response was further improved by co-administration of adjuvants, showing a progressive increase in serum IgG titers when adjuvanted with LPS, Quil A, CpG and CT. IgG titers of the CT-adjuvanted group reached levels comparable to those obtained after DT-alum subcutaneous injection. The IgG1/IgG2a ratio of DT-specific antibodies decreased in the following sequence: plain DT, Quil A, CT and CpG, suggesting that the immune response was skewed towards the Th1 direction.

Conclusions

The potency and the quality of the immune response against DT administered by microneedle array mediated TCI can be modulated by co-administration of adjuvants.

Glial fibrillary acidic protein promoter targets pancreatic stellate cells

BACKGROUND

Pancreatic fibrosis is one of the clinical manifestations of chronic pancreatitis and pancreatic cancer. Pancreatic stellate cells (PSCs) have been recognised as principal effector cells in the development of pancreatic fibrosis. The ability to specifically address PSCs might offer a potential for developing a targeted therapy for pancreatic fibrosis.

AIM

Characterisation of the 2.2kb hGFAP (human glial fibrillary acidic protein) promoter for its usefulness to express reporter genes specifically in PSCs in vitro and in vivo.

METHODS

2.2kb hGFAP-LacZ reporter expressions were examined in four immortalised PSC lines and two non-PSCs, meanwhile, GFAP-LacZ transgenic mice were used to detect LacZ reporter in pancreas tissue. Several kinase inhibitors, vitamin A and its metabolites were applied to study the regulation of 2.2kb hGFAP promoter in PSCs.

RESULTS

Our results showed that the 2.2kb hGFAP promoter is capable of regulating the expression of reporter genes exclusively in immortalised and primary PSCs, as well as in PSCs of transgenic GFAP-LacZ mice. When a PSC cell line transfected with the LacZ reporter (SAM-K/LacZ/C1) was treated with different anti-fibrotic agents and kinase inhibitors, the transgenic beta-galactosidase activity was found to be regulated by multiple signalling pathways known to be involved in the PSC activation.

CONCLUSIONS

This study provides the proof of concept for using the 2.2kb hGFAP promoter to specifically manipulate PSCs for the development of targeted gene and/or drug therapy in pancreatic fibrosis, and for the screening of anti-fibrotic agents.

Pten and p53 converge on c-Myc to control differentiation, self-renewal, and transformation of normal and neoplastic stem cells in glioblastoma

Glioblastoma (GBM) is a highly lethal primary brain cancer with hallmark features of diffuse invasion, intense apoptosis resistance and florid necrosis, robust angiogenesis, and an immature profile with developmental plasticity. In the course of assessing the developmental consequences of central nervous system (CNS)-specific deletion of p53 and Pten, we observed a penetrant acute-onset malignant glioma phenotype with striking clinical, pathological, and molecular resemblance to primary GBM in humans. This primary, as opposed to secondary, GBM presentation in the mouse prompted genetic analysis of human primary GBM samples that revealed combined p53 and Pten mutations as the most common tumor suppressor defects in primary GBM. On the mechanistic level, the "multiforme" histopathological presentation and immature differentiation marker profile of the murine tumors motivated transcriptomic promoter-binding element and functional studies of neural stem cells (NSCs), which revealed that dual, but not singular, inactivation of p53 and Pten promotes cellular c-Myc activation. This increased c-Myc activity is associated not only with impaired differentiation, enhanced self-renewal capacity of NSCs, and tumor-initiating cells (TICs), but also with maintenance of TIC tumorigenic potential. Together, these murine studies have provided a highly faithful model of primary GBM, revealed a common tumor suppressor mutational pattern in human disease, and established c-Myc as a key component of p53 and Pten cooperative actions in the regulation of normal and malignant stem/progenitor cell differentiation, self-renewal, and tumorigenic potential.

Expression of tubulin, p53, ki67, receptors for estrogen, and progesterone in endometrial cancer

OBJECTIVE

We aimed at investigating by immunohistochemistry the relationship between tubulin and histological features of tumors, estrogen receptors (ER), progesterone receptors (PR), expression of p53, and Ki67 in a series of 84 primary untreated endometrial cancer patients.

METHODS

Immunohistochemistry was performed on paraffin-embedded sections by using rabbit polyclonal antiserum against human class III beta-tubulin, anti-ER, anti-PR, anti Ki67 and p53 monoclonal antibodies.

RESULTS

Expression of class III beta-tubulin in proliferative phase endometrium was significantly higher than that in the secretory phase (X2 = 5.49, p value = 0.029). There was no difference in the distribution of tubulin positive cases between normal endometrium and endometrial carcinoma (X2 = 0.46, p value > 0.05). The immunostaining pattern of tubulin did not correlate with age, clinical stage, histological grade, depth of invasion, or expression of p53, Ki67, ER, and PR. Expression of ER and PR correlated with histological grade. Expression of p53 and Ki67 correlated with clinical stage and histological grade.

CONCLUSIONS

We suggest that class III beta-tubulin plays an important role during the normal biological processes of endometrium. It seems that tubulin has no prognostic value in endometrial carcinoma.

Functional electrical stimulation cycling improves body composition, metabolic and neural factors in persons with spinal cord injury

Persons with spinal cord injury (SCI) are at a heightened risk of developing type II diabetes and cardiovascular disease. The purpose of this investigation was to conduct an analysis of metabolic, body composition, and neurological factors before and after 10 weeks of functional electrical stimulation (FES) cycling in persons with SCI. Eighteen individuals with SCI received FES cycling 2-3 times per week for 10 weeks. Body composition was analyzed by dual X-ray absorptiometry. The American Spinal Injury Association (ASIA) neurological classification of SCI test battery was used to assess motor and sensory function. An oral glucose tolerance (OGTT) and insulin-response test was performed to assess blood glucose control. Additional metabolic variables including plasma cholesterol (total-C, HDL-C, LDL-C), triglyceride, and inflammatory markers (IL-6, TNF-alpha, and CRP) were also measured. Total FES cycling power and work done increased with training. Lean muscle mass also increased, whereas, bone and adipose mass did not change. The ASIA motor and sensory scores for the lower extremity significantly increased with training. Blood glucose and insulin levels were lower following the OGTT after 10 weeks of training. Triglyceride levels did not change following training. However, levels of IL-6, TNF-alpha, and CRP were all significantly reduced.

Two rare cases of methotrexate-induced pneumonitis and pleurisy in patients with gestational trophoblastic neoplasms

BACKGROUND

Pneumonitis is a serious and unpredictable side-effect of treatment with methotrexate (MTX) that may result in a life-threatening outcome. Pulmonary toxicity of methotrexate in patients with a gestational trophoblastic neoplasm (GTN) has rarely been reported before.

CASE REPORTS

For the first time two cases of methotrexate-induced pneumonitis and pleurisy in GTN patients of Chinese ethnicity are presented. Two patients were both categorized as the low-risk group, and underwent a single regimen therapy of methotrexate. Their symptoms, such as fever, chest pain, acute nonproductive cough, dyspnea and hypoxemia did not respond to antibiotics immediately. Treatment with corticosteroids may be helpful.

CONCLUSION

Awareness of pneumonitis and pleurisy, potentially life-threatening complications of MTX, is very necessary and important to early recognition and treatment.

Experimental study on genistein prevention and treatment of transplant arteriosclerosis in aortic transplants of rat

OBJECTIVE

Our objective was to study the effects of genistein, a soy isoflavone, on transplant arteriosclerosis, in addition to its immunosuppressive and antioxidant properties.

MATERIALS AND METHODS

We performed male Brown-Norway to male Lewis aortic transplantation. The recipients were randomly assigned to 3 groups: no treatment controls, dimethyl sulfoxide (DMSO; 5 mL/kg) solvent controls, and experimental group that received genistein (20 mg/kg/d) by daily intraperitoneal injection. On postoperative day 60, the graft was harvested and blood obtained. The transplanted aorta was analyzed by histology and immunohistochemistry. The serum was analyzed by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with the 2 controls, leukocyte recruitment to the graft was significantly inhibited by genistein, with a profound reduction in the number of CD69 macrophages infiltrating the adventitia of the transplanted aortas. Moreover, genistein significantly inhibited the expression of VEGF and IFN-gamma production (P < .01).

CONCLUSION

These results suggested that the protein tyrosine kinase inhibitor genistein inhibited graft arteriosclerosis.

Administration-route and gender-independent long-term therapeutic correction of phenylketonuria (PKU) in a mouse model by recombinant adeno-associated virus 8 pseudotyped vector-mediated gene transfer

Phenylketonuria (PKU) is an inborn error of metabolism caused by deficiency of the hepatic enzyme phenylalanine hydroxylase (PAH) which leads to high blood phenylalanine (Phe) levels and consequent damage of the developing brain with severe mental retardation if left untreated in early infancy. The current dietary Phe restriction treatment has certain clinical limitations. To explore a long-term nondietary restriction treatment, a somatic gene transfer approach in a PKU mouse model (C57Bl/6-Pahenu2) was employed to examine its preclinical feasibility. A recombinant adeno-associated virus (rAAV) vector containing the murine Pah-cDNA was generated, pseudotyped with capsids from AAV serotype 8, and delivered into the liver of PKU mice via single intraportal or tail vein injections. The blood Phe concentrations decreased to normal levels (< or =100 microM or 1.7 mg/dl) 2 weeks after vector application, independent of the sex of the PKU animals and the route of application. In particular, the therapeutic long-term correction in females was also dramatic, which had previously been shown to be difficult to achieve. Therapeutic ranges of Phe were accompanied by the phenotypic reversion from brown to black hair. In treated mice, PAH enzyme activity in whole liver extracts reversed to normal and neither hepatic toxicity nor immunogenicity was observed. In contrast, a lentiviral vector expressing the murine Pah-cDNA, delivered via intraportal vein injection into PKU mice, did not result in therapeutic levels of blood Phe. This study demonstrates the complete correction of hyperphenylalaninemia in both males and females with a rAAV serotype 8 vector. More importantly, the feasibility of a single intravenous injection may pave the way to develop a clinical gene therapy procedure for PKU patients.

Haploinsufficiency of the mSds3 chromatin regulator promotes chromosomal instability and cancer only upon complete neutralization of p53

The mSin3 corepressor complex has been linked to diverse cancer signaling pathways through its capacity to regulate target gene expression via chromatin modification. mSds3, a cell essential gene, is a key component of the mSin3 complex serving to maintain its inherent histone deacetylase activity. mSds3 also serves an essential role in the establishment of pericentric heterochromatin, and genetic ablation of mSds3 results in chromosome missegregation. In contrast, mSin3A nullizygous cells show normal chromosome dynamics and cytogenetic profiles. The integral role of mSds3 in controlling chromosome segregation and mSin3-regulated transcriptional networks prompted efforts to determine the neoplastic impact of loss of one copy of mSds3 or mSin3A. In particular, we assessed whether loss of one copy of mSds3, alone or in combination with p53 mutation, results in aneuploidy and promotes a cancer-prone condition in the mouse. We observe that, in a p53 null background, loss of one mSds3 allele results in accelerated tumor onset and increased tumor burden. Notably, these mSds3(+/-) p53(-/-) tumors exhibit a more complex cytogenetic profile characterized by marked aneuploidy and centromeric associations. The presence of even one copy of p53 is sufficient to suppress the accelerated tumorigenesis in mSds3(+/-) mice, consistent with a key role for p53 in monitoring mitotic fidelity. These observations with Sds3 mutant mice contrast with mSin3A(+/-) p53(-/-) mice, which do not show an accelerated or increased tumor incidence relative to mSin3A(+/+)p53(-/-) controls, correlating with the absence of aneuploidy detected upon mSin3A genetic inactivation. This genetic study establishes that the capacity of mSds3 to cooperate with p53 deficiency in cancer predisposition relates to its specific role in chromosome segregation, rather than its central role in maintaining a functional mSin3A complex.

Morphological study of the interaction between M21 melanoma and lymphatic endothelium

In order to study the interaction between melanoma and lymphatic endothelial cells (LECs) and to investigate the mechanism of lymphatic metastasis, M21 melanoma cells were seeded on the confluent LECs monolayer and the alterations of both cells were observed. The results showed that tumor cells could both adhere by pseudopodia to LECs at the site near the intercellular junction and on the apical surface. The adhesion of the melanoma cells induced the endothelial junction dissolution and endothelial retraction, which allowed the passage of the tumor cells through the opened gap and attached to the subendothelial matrix, then the tumor cells invaded and migrated under the LECs monolayer. These findings suggest that tumor cells could metastasize through the lymphatic vessel by destroying intercellular junctions or the LECs directly.

Overexpression of sorcin enhances cardiac contractility in vivo and in vitro

Sorcin (SOR), an EF-hand Ca(2+)-binding protein, interacts with the sarcolemmal proteins Annexin VII and L-type Ca(2+)-channel and with the sarcoplasmic reticulum (SR) Ca(2+)-release channel (ryanodine-receptor, RYR), and has been implicated to influence the intracellular Ca(2+)-homeostasis. The present study aimed at investigating the effects of increased SOR expression on force development and relaxation in virus transfected rat hearts and isolated cardiomyocytes. We generated an adenovirus encoding the SOR coding DNA with a separate cassette for green fluorescent protein (GFP) both driven by the CMV-promoter to induce SOR-overexpression (Ad.SOR.GFP). As control served an adenovirus carrying an empty cassette with a separate cassette for GFP also driven by CMV-promoters (Ad.GFP). Cardiomyocytes of healthy male rats were isolated, transfected and cultured for 48 h with Ad.SOR.GFP as well as Ad.GFP as control. In addition, Ad.SOR.GFP was injected into coronary arteries via a catheter-based technique and rat hearts were transfected in vivo for 12 days. Echocardiography was performed to assess cardiac function at 7 and 12 days before the animals were sacrificed. A 1.7-fold increase of the SOR protein amount in cultured myocytes treated with Ad.SOR.GFP compared to Ad.GFP-transfected cells indicated a successful overexpression of SOR. Cell-contracting experiments using infected cardiomyocytes (transfection: 48 h; frequency: 0.5 Hz) exhibited a significantly higher peak force of contraction (FOC) in the SOR-overexpression group (n = 64) vs. control (n = 21) (6.8% +/- 0.2% vs. 4.3% +/- 0.1%). Beta-adrenergic stimulation with forskolin resulted in similar increases in FOC. Echocardiography of in vivo transfected rat hearts exhibited enhanced fractional shortening (65.9 +/- 5.5% vs. 79.3 +/- 2.5%) and decreased end-systolic diameters indicating enhanced cardiac contractility. Gross morphology was similar in both groups after 14 days of transfection. These results strengthen the notion that overexpression of SOR improves cardiac contractility independent of beta-adrenergic stimulation and may prove beneficial in the treatment of decreased cardiac output such as heart failure.

VEGF165 and angiopoietin-1 decreased myocardium infarct size through phosphatidylinositol-3 kinase and Bcl-2 pathways

Angiogenic growth factors, vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang1) could decrease myocardial infarct size, which was assumed to be related with newly formed capillaries. We doubted that these capillaries could do this solely and the potential protective mechanisms of VEGF and Ang1 on myocardium need to be evaluated. Three types of adenoviruses encoding human VEGF(165) (Ad-VEGF(165)), human angiopoietin-1 (Ad-Ang1) and green fluorescent protein (Ad-GFP, as a parallel control) were constructed. Experiments were taken both in vitro and in vivo. As in vitro, the antiapoptosis effect of VEGF(165), Ang1 and VEGF(165)+Ang1 on cardiac myoblasts was observed, which seemed to be related with the activation of phosphatidylinositol-3 kinase and Bcl-2 pathways. As in vivo, adenoviruses were intramyocardially injected immediately after the ligation of the left anterior descending coronay arteries in rats. The results showed positive effect of VEGF(165), Ang1 and VEGF(165)+Ang1 on decreasing the myocardial infarct size at the 7th day. Myocardial PI-3K activity and Bcl-2 expression were elevated relatively at the 3rd day. The protective effect of VEGF(165) and Ang1 on the myocardium may broaden their functional research and contribute to their clinical use in the future.

A minimally invasive approach for efficient gene delivery to rodent hearts

Transcoronary gene delivery represents a desirable option to achieve global myocardial transgene expression but still requires aggressive surgical preparation in rodents. We therefore developed a catheter-based approach for cardiac gene transfer in the closed chest rat. A double-lumen balloon catheter was used to create aortic occlusion for specific infusion of adenoviral vectors carrying a beta-galactosidase transgene (1 x 10(11) PFU) into the coronaries. Simultaneously, venous return was obstructed by a second balloon catheter in the right atrium. To prolong viral incubation time, we induced a transient cardiac arrest (2 and 5 min) by a combination of acetylcholine and the beta-receptor antagonist, esmolol. At 72 h after transfection, the hearts showed a homogeneous and widespread beta-galactosidase expression, and the transduction efficiency increased and up to about 43% of cardiac myocytes (histochemistry) with a 400-fold increase of beta-galactosidase activity (luminescence assay) compared to sham-operated hearts. Pharmacological treatment aimed at increasing vascular permeability (SNAP and histamine) did not bring about synergistic effects on transfection efficiency. In addition, the method using high intracoronary pressure delivery (>300 mmHg) in a single-pass manner resulted in rather sparse beta-galactosidase expression in the myocardium (3-5% of cardiac myocytes). Therefore, the percutaneous gene delivery system described here provides a simple and minimally invasive procedure that represents a novel strategy for a homogeneous and highly efficient in vivo gene transfer to rodent hearts. Our results also suggest that prolongation of viral incubation time is an effective means for achieving highly efficient myocardial gene transduction.

Raman spectroscopy of selected arsenates--implications for soil remediation

The contamination of soils with heavy metals such as As, Cr and Cu is of great importance; the remediation of such soils even more so. Arsenic compounds are prevalent in soils either through leaching of mine tailings, the use of Cu/Cr/As as a wood preservative or through the use of arsenic in cattle dips. The arsenic compounds in soils and leachates can be highly reactive and mobile, resulting in the formation of metal arsenate compounds. Of these compounds, one such set of minerals that can be formed is the vivianite arsenate minerals. Raman spectroscopy has been used to characterise the vivianite arsenates and to identify arsenic contaminants in a soil.

Coxsackie-and-adenovirus receptor mRNA expression in human heart failure

BACKGROUND

Adenoviral vectors are widely used as gene-transfer vehicles in experimental and clinical studies. Since virus incorporation and transfection efficacy depend to a large extent on the concentration of the coxsackie-and-adenovirus (CAR) receptor on target cells the aim of this study was to quantify the CAR-receptor concentration in various human cardiomyopathies.

METHODS

After RNA isolation from myocardial biopsies obtained during surgical procedures, cDNA was generated by reverse transcription. The relative RNA content was analyzed by quantitative PCR using glyceraldehydes-3-phosphate dehydrogenase (GAPDH) as a standard reference. The cardiomyopathies (CM) analyzed were categorized according to their etiology in dilated CM (DCM, n = 28), ischemic CM (ICM, n = 52), CM in mitral valve disease (MVCM, n = 32) and aortic valve disease (AVCM, n = 32). Data were related to non-cardiomyopathic tissue from donor hearts (non-CM, n = 64).

RESULTS

Compared with non-CM hearts DCM showed a 34-fold (+/-5.4) increase in CAR mRNA concentration, in ICM CAR mRNA was elevated by a factor of 12 (+/-4.3), in MVCM by 27 (+/-7) and AVCM by factor 47 (+/-9.3) (ANOVA p < 0.001). Compared with the expression in rat hearts CAR levels were found to be similar to those in human ICM.

CONCLUSIONS

These results show that cardiomyopathies associated with heart failure transcribe substantially higher levels - on average by a factor of 30 - of CAR-mRNA than non-failing control hearts. Myocardial gene transfer using adenoviral vectors should therefore be facilitated in human cardiomyopathies and may present a promising approach for therapeutic interventions.

Atomic-scale observation of temperature and pressure driven preroughening and roughening

Preroughening and roughening transitions are observed on the GaAs(001) surface using scanning tunneling microscopy. By tuning the substrate temperature or As4 pressure the surface morphology can be made free of islands, covered with one monolayer high islands or covered with islands on top of islands forming a wedding-cake-type structure. These three distinct surface morphologies are classified as ordered flat (OF), disordered flat (DOF), and rough within the restricted solid-on-solid model. Here, the DOF phase is macroscopically flat; however, an up-down-up-down step pattern persists across the entire surface. Using this model we have determined the next-nearest-neighbor interaction energy to be about 0.05 eV.

Molecular assembly in synthesised hydrotalcites of formula Cu(x)Zn(6 - x)Al2(OH)16(CO3) x 4H2O--a vibrational spectroscopic study

Infrared and Raman spectroscopy have been used to characterise synthetic hydrotalcites of formula Cu(x)Zn(6 - x)Al2(OH)16(CO3) x 4H2O. The spectra have been used to assess the molecular assembly of the cations in the hydrotalcite structure. The spectra may be conveniently subdivided into spectral features based (a) upon the carbonate anion (b) the hydroxyl units (c) water units. The Raman spectra of the hydroxyl-stretching region enable bands to be assigned to the CuOH, ZnOH and AlOH units. It is proposed that in the hydrotalcites with minimal cationic replacement that the cations are arranged in a regular array. For the Cu(x)Zn(6 - x)Al2(OH)16(CO3) x 4H2O hydrotalcites, spectroscopic evidence suggests that 'islands' of cations are formed in the structure. In a similar fashion, the bands assigned to the interlayer water suggest that the water molecules are also in a regular well-structured arrangement. Bands are assigned to the hydroxyl stretching vibrations of water. Three types of water are identified (a) water hydrogen bonded to the interlayer carbonate ion (b) water hydrogen bonded to the hydrotalcite hydroxyl surface and (c) interlamellar water. It is proposed that the water is highly structured in the hydrotalcite as it is hydrogen bonded to both the carbonate anion and the hydroxyl surface.

A gene therapy for cancer based on the angiogenesis inhibitor, vasostatin

The growth and persistence of solid tumors and their metastasis are angiogenesis-dependent. Vasostatin, the N-terminal domain of calreticulin inclusive of amino acids 1-180, is a potent angiogenesis inhibitor. To investigate whether intramuscular administration of vasostatin gene has the antitumor activity in mouse tumor models, we constructed a plasmid DNA encoding vasostatin and a control vector. Production and secretion of vasostatin protein by COS cells transfected with the plasmid DNA encoding vasostatin (pSecTag2B-vaso) were confirmed by Western blot analysis and ELISA. Conditioned medium from vasostatin-transfected COS cells apparently inhibited human umbilical vein endothelial cell (HUVEC) and mouse endothelial cell (SVEC4-10) proliferation, compared with conditioned medium from the COS cells transfected with control vector or non-transfected cells. Treatment with pSecTag2B-vaso twice weekly for 4 weeks resulted in the inhibition of tumor growth and the prolongation of the survival of tumor-bearing mice. The sustained high level of vasostatin protein in serum could be identified in ELISA. Angiogenesis was apparently inhibited in tumor by immunohistochemical analysis. Angiogenesis was also inhibited in the chicken embryo CAM assay and mouse corneal micropocket assay. The increased apoptotic cells were found within the tumor tissues from the mice treated with plasmid DNA encoding vasostatin. Taken together, the data in the present study indicate that the cancer gene therapy by the intramuscular delivery of plasmid DNA encoding vasostatin, is effective in the inhibition of the systemic angiogenesis and tumor growth in murine models. The present findings also provide further evidence of the anti-tumor effects of the vasostatin, and may be of importance for the further exploration of the application of this molecule in the treatment of cancer.

Flow field and oscillatory shear stress in a tuning-fork-shaped model of the average human carotid bifurcation

The oscillatory shear index (OSI) was developed based on the hypothesis that intimal hyperplasia was correlated with oscillatory shear stresses. However, the validity of the OSI was in question since the correlation between intimal thickness and the OSI at the side walls of the sinus in the Y-shaped model of the average human carotid bifurcation (Y-AHCB) was weak. The objectives of this paper are to examine whether the reason for the weak correlation lies in the deviation in geometry of Y-AHCB from real human carotid bifurcation, and whether this correlation is clearly improved in the tuning-fork-shaped model of the average human carotid bifurcation (TF-AHCB). The geometry of the TF-AHCB model was based on observation and statistical analysis of specimens from 74 cadavers. The flow fields in both models were studied and compared by using flow visualization methods under steady flow conditions and by using laser Doppler anemometer (LDA) under pulsatile flow conditions. The TF-shaped geometry leads to a more complex flow field than the Y-shaped geometry. This added complexity includes strengthened helical movements in the sinus, new flow separation zone, and directional changes in the secondary flow patterns. The results show that the OSI-values at the side walls of the sinus in the TF-shaped model were more than two times as large as those in the Y-shaped model. This study confirmed the stronger correlation between the OSI and intimal thickness in the tuning-fork geometry of human carotid bifurcation, and the TF-AHCB model is a significant improvement over the traditional Y-shaped model.

The investigational new drug XK469 induces G(2)-M cell cycle arrest by p53-dependent and -independent pathways

PURPOSE

XK469 (2-[4-(7-chloro-2-quinoxalinyloxy) phenoxy]propionic acid), a synthetic quinoxaline phenoxypropionic acid derivative, has broad activity against murine tumors and is entering Phase I clinical development as a topoisomerase IIbeta inhibitor. This study investigated the underlying molecular mechanism of XK469's effects on the cell cycle.

EXPERIMENTAL DESIGN

Growth inhibition, cell cycle arrest, induction of p53 and p21 mRNA and protein, and cdc2 phosphorylation and kinase activity were studied in treated cells from the H460 lung cancer line and p21 and p53 knockout cells of the HCT 116 colon cancer line.

RESULTS

XK469 arrested H460 cells at G(2)-M, which was associated with cdc2 phosphorylation and decreased cdc2 kinase activity. Moreover, XK469 stabilized p53 and subsequently increased p21(WAF1/CIP1). Furthermore, HCT116 p21(-/-) cells were less sensitive than wild-type cells to XK469-induced growth inhibition, but p53(+/+) and p53(-/-) cells were equally sensitive despite the absence of p21 induction in the p53(-/-) cells.

CONCLUSIONS

When considered with published data, our study suggests a complex mechanism of XK469-mediated anticancer activity involving multiple pathways, including p53-dependent and -independent G(2)-M arrest via inactivation of cdc2-cyclin B1 kinase activity.

New antibody purification procedure using a thermally responsive poly(N-isopropylacrylamide)-dextran derivative conjugate

Through their specificity and affinity, antibodies are useful tools in research and medicine. In this study, we investigated a new type of chromatographic method using a thermosensitive polymer for the purification of antibodies against a dextran derivative (DD), as a model. The thermally reversible soluble-insoluble poly(N-isopropylacrylamide)-dextran derivative conjugate, named poly(NIPAAm)-DD, has been synthesized by conjugating amino-terminated poly(N-isopropylacrylamide) to a DD via ethyl-3-(3-dimethylaminopropyl)-carbodiimide. On one hand, this report describes the two steps of poly(NIPAAm)-DD conjugation and characterization. On the other hand, the poly(NIPAAm)-DD conjugate was used as a tool to purify polyclonal antibodies in serum samples from rabbits subcutaneously immunized with the derivatized dextran. Antibodies were purified and quantified by immunoenzymatic assays. Our results indicate that antibodies recognized both DD and poly(NIPAAm)-DD. In contrast, they did not bind to native poly(NIPAAm) or poly(NIPAAm) conjugated with another anionic dextran. We conclude that the conjugation of a polysaccharide to poly(NIPAAm) leads to an original and efficient chromatographic method to purify antibodies. Moreover, this novel method of purification is rapid, sensitive, inexpensive and could be used to purify various types of antibodies.

A sensitive and rapid method for the determination of protein by the resonance Rayleigh light-scattering technique with Pyrogallol Red

The resonance Rayleigh light-scattering (RRLS) technique was used to develop a simple, sensitive and selective method for the determination of proteins. The method is based on the interaction between proteins and Pyrogallol Red (PR) in the pH range 3.6-4.2, which causes a substantial enhancement of the resonance scattering signal of PR in the wavelength range 300-450 nm with the maximum scattering peak located at 347 nm. With this method, 0.25-13 microg ml(-1) of bovine serum albumin (BSA), 0.25-10 microg ml(-1) of human serum albumin (HSA) and 0.25-13 microg ml(-1) of human immunoglobulin G (IgG) can be determined, and the detection limits, calculated as three times the standard deviation of nine blank measurements, for BSA, HAS and IgG were 51, 48 and 57 microg l(-1), respectively. Moreover, the method shows almost no protein-to-protein variability and is free from interference from many amino acids and metal ions. The method, with high sensitivity, selectivity and reproducibility, was satisfactorily applied to the determination of the total protein in human serum and saliva samples. Mechanism studies indicated that PR can bind to BSA depending mainly on electrostatic forces, and this interaction can encourage the J-aggregation of PR, which results in enhanced Rayleigh light-scattering in the PR-protein system.

Activities of virE1 and the VirE1 secretion chaperone in export of the multifunctional VirE2 effector via an Agrobacterium type IV secretion pathway

Agrobacterium tumefaciens uses a type IV secretion system to deliver oncogenic nucleoprotein particles and effector proteins, such as the multifunctional VirE2 protein, to plant cells. In this study, we examined the function of virE1 and its product, the VirE1 secretion chaperone, in mediating VirE2 export. A nonpolar virE1 null mutant accumulated low levels of VirE2, and trans expression of virE1 in this mutant only partially restored VirE2 abundance. Deletion of virE1 did not affect transcription but decreased translation of virE2, as shown by analysis of lacZ transcriptional and translational fusions. VirE2 was stable for a prolonged period, more than 6 h, when it was expressed in cis with virE1, and it exhibited half-lives of about 2 h when it was expressed in trans with virE1 and less than 10 min when it was expressed in the absence of virE1, as shown by pulse-chase experiments. VirE1 stabilized VirE2 via an interaction with a domain near the N terminus of VirE2, as shown by analyses of VirE2 truncation and insertion mutants synthesized in A. tumefaciens. VirE1 self-association was demonstrated by using bacteriophage lambda cI repressor fusion and pull-down assays, and evidence of VirE1 homomultimerization in vivo was obtained by native polyacrylamide gel electrophoresis and gel filtration chromatography. A putative VirE1-VirE2 complex with a molecular mass of about 70 to 80 kDa was detected by gel filtration chromatography of extracts from wild-type cells, whereas higher-order VirE2 complexes or aggregates were detected in extracts from a virE1 mutant. Taken together, our findings show that virE1 contributes in several ways to VirE2 export:(i) virE1 regulates efficient virE2 translation in the context of expression from the native P(virE) promoter; (ii) the VirE1 secretion chaperone stabilizes VirE2, most probably via an interaction with an N-terminal domain; and (iii) VirE1 forms a VirE1-VirE2 complex with a predicted 2:1 stoichiometry that inhibits assembly of higher-order VirE2 complexes or aggregates.

How does heme axial ligand deletion affect the structure and the function of cytochrome b(562)?

We have recently generated a new mutant of cytochrome b(562) (cytb(562)) in which Met7, one of the axial heme ligands, is replaced by Ala (M7A cytb(562)). The M7A cytb(562) can bind heme and the UV-visible absorption spectrum is of a typical high-spin ferric heme. To investigate the effect of the lack of Met7 ligation on the structural integrity of cytb(562), thermal transition analyses of M7A cytb(562) were conducted. From the thermodynamic parameters obtained, it is concluded that the folding of M7A cytb(562) is comparable to the apoprotein despite the presence of heme. On the other hand, exogenous ligands such as cyanide and azide ions are readily bound to the heme iron, indicating that the axial coordination site is available for substrate binding. The peroxidase activity of this mutant is thus examined to evaluate new enzymatic function at this site and M7A cytb(562) was found to catalyze an oxidation reaction of aromatic substrates with hydrogen peroxide. These observations demonstrate that the Met7/His102 bis-ligation to the heme iron is crucial for the stable folding of cytb(562), whereas the functional conversion of cytb(562) is successfully achieved by the loose folding together with the open coordination site.

Characterization of Pore Structure and Coordination of Titanium in TiO2 and SiO2–TiO2 Sol-Pillared Clays

Titania sol-pillared clay (TiO(2) PILC) and silica-titania sol-pillared clay (SiO(2)-TiO(2) PILC) were synthesized by the sol-gel method. Supercritical drying (SCD) and treatment with quaternary ammonium surfactants were used to tailor the pore structure of the resulting clay. It was found that SCD approach increased the external surface area of the PILCs dramatically and that treatment with surfactants could be used to tailor pore size because the mesopore formation in the galleries between the clay layers follows the templating mechanism as observed in the synthesis of MCM-41 materials. Highly mesoporous solids were thus obtained. In calcined TiO(2) PILC, ultrafine crystallites in anatase phase, which are active for photocatalytic oxidation of organics, were observed. In SiO(2)-TiO(2) PILCs and their derivatives, titanium was highly dispersed in the matrix of silica and no crystal phase was observed. The highly dispersed titanium sites are good catalytic centers for selective oxidation of organic compounds. Copyright 2001 Academic Press.

Spatially Resolved Spin-Injection Probability for Gallium Arsenide

We report a large spin-polarized current injection from a ferromagnetic metal into a nonferromagnetic semiconductor, at a temperature of 100 Kelvin. The modification of the spin-injection process by a nanoscale step edge was observed. On flat gallium arsenide [GaAs(110)] terraces, the injection efficiency was 92%, whereas in a 10-nanometer-wide region around a [111]-oriented step the injection efficiency is reduced by a factor of 6. Alternatively, the spin-relaxation lifetime was reduced by a factor of 12. This reduction is associated with the metallic nature of the step edge. This study advances the realization of using both the charge and spin of the electron in future semiconductor devices.

Bioadsorption of lead(II) from aqueous solution by fungal biomass of Aspergillus niger

The removal of lead by waste fungal biomass of Aspergillus niger, originated from citric acid fermentation industry, was investigated. The experimental results indicated that the bioadsorption achieved equilibrium within 4 h. The kinetic analysis of lead adsorption onto the fungal biomass revealed that the bioadsorption process followed the first-order reaction kinetics. The adsorption isotherm can be simulated by Freundlich model, which gave a correlation coefficient equal to 0.93. The lead-loaded biomass can be effectively regenerated by 0.1 M nitric acid. This research demonstrated that the waste biomass of A. niger is a potential bioadsorbent for the removal of lead from aqueous solution.