Transmission Electric Microscopy Research Articles

Effectiveness of hot deformation and subsequent annealing for β grain refinement of Ti–5Al–5Mo–5V–1Cr–1Fe titanium alloy

High strength titanium alloys suffer from a limited combination of strength and ductility. Considering their microstructure, the coarse β grain is a detrimental factor. In the present study, the effects of hot deformation and annealing treatment on the β grain refinement of Ti–5Al–5Mo–5V–1Cr–1Fe (TC18) titanium alloy have been investigated by using electronic backscattered diffraction (EBSD) and transmission electric microscopy (TEM). Hot compression tests of TC18 alloy were performed between 1073 and 1223 K at strain rates of 0.01 and 0.10 s−1. Subsequent annealing treatments were conducted to investigate the effect of deformation microstructure on the recrystallization behavior of β grains. The results indicate that dynamic recovery (DRV) is the dominant restoration mechanism during hot deformation. Discontinuous dynamic recrystallization (dDRX) is significantly limited at a higher temperature in the β region, whereas continuous dynamic recrystallization (cDRX) of the β phase is observed at a higher strain rate in the (α + β) region. The final annealing microstructure is highly dependent on the deformation microstructure. Limited dDRX during hot deformation could not effectively refine the β grains. The refined and uniform β grains with an average grain size of 12 μm are achieved by combining hot deformation and subsequent annealing in the (α + β) region. This study provides a guide for the β grain refinement of high strength titanium alloys.

Self-assembly behavior of amphiphilic polyelectrolyte with ultrahigh charge density

A series of novel amphiphilic polyelectrolytes with ultrahigh charge density were synthesized by copolymerization of monomers with double-quaternary ammonium groups. The self-assembly properties of the amphiphilic polyelectrolyte with ultrahigh charge density in aqueous solutions have been investigated by means of steady-state fluorescence, dynamic light scattering (DLS), transmission electric microscopy (TEM), and zeta potential measurements. The critical aggregation concentrations (cac) of the polyelectrolytes decreased as the molar content of hydrophobic segments and the length of hydrophobic carbon chains increased. The sizes of the aggregates in the polyelectrolyte solution increased as the concentration of the solution and the molar content of hydrophobic units increased. Compared with the counterparts of the single quaternized ammonium groups in hydrophilic units, the values of cac of the novel ultrahigh charge density polyelectrolytes were larger; however, the size and the zeta potential of aggregates in aqueous solutions were smaller than that of the former. These phenomena were ascribed to the strong hydrophilic capacity and electrostatic repulsions existed in the double quaternized groups of polyelectrolytes.

Dipotassium phosphate improves the molecular weight stability of polysialic acid in Escherichia coli K235 culture broth

This work elucidated the intrinsic mechanism underlying the influence of K2HPO4 on PSA production and molecular weight (MW) stability. Among the different potassium salts mixed with K2HPO4 in the initial medium, those with buffering capacity were favorable for PSA production. In the bioreactor culture with pH control, adding an appropriate concentration of K2HPO4 could enhance PSA production. A dual-phase pH control strategy with ammonia water and KOH could also increase the yield and maintain the MW stability of PSA. Zeta potential test, UV/circular dichroism spectra, and transmission electric microscopy were utilized to explore the configuration of K2HPO4–PSA complex. The results from this study can serve a good basis for the industrial-scale production of PSA with stable MW.

Enhanced effect in combination of curcumin- and ketoconazole-loaded methoxy poly (ethylene glycol)-poly (ε-caprolactone) micelles.

In order to enhance water-solubility and realize controlled release while keeping synergistic effects of ketoconazole and curcumin, drug-loaded methoxy poly (ethylene glycol)-b-poly (ε-caprolactone) micelles were prepared through thin membrane hydration method. Transmission electric microscopy and dynamitic light scattering characterization revealed the formation of ketoconazole- and curcumin-loaded micelles with an average size of 44.70nm and 39.56nm, respectively. The drug-loaded micelles endowed the two drugs' slow controlled release with water-solubility enhanced to 85 and 82000 folds higher than the corresponding raw drugs, respectively. In vitro antifungal activity test, chequerboard test and inhibition zone test indicated that efficacy of ketoconazole-loaded micelles was improved by introduction of curcumin-loaded micelles with a low fractional inhibitory concentration index (0.073). Biofilm formation inhibition assay also demonstrated that participation of curcumin-loaded micelles obviously strengthened the inhibition of fungal biofilms formation induced by ketoconazole-loaded micelles. The high synergistic activity of combinations is encouraging and the MPEG-PCL micelle is a potential drug delivery system for the combination of ketoconazole and curcumin.

Graphene nanosheets prepared by low-temperature exfoliation and reduction technique toward fabrication of high-performance poly(1-butene)/graphene films

Thermal exfoliation and reduction of graphene oxide (GO) were performed to prepare graphene nanosheets at 300 °C under the ambient atmosphere without any supplementary conditions. The microstructure and morphology of the resulting graphene nanosheets were characterized with scanning electron microscopy, transmission electric microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. The composite films based on poly(1-butene) (PB) and graphene nanosheets were prepared successfully through solution blending and compression molding. The morphological investigation suggested that the graphene nanosheets with nanoscale thickness achieved a homogeneous dispersion in the PB matrix. The composite films exhibited a sharp transition from insulating state to the conducting one with a low percolation threshold, followed by a high electrical conductivity at graphene content higher than 1.6 vol %. The composite films also achieved high dielectric constant with low dielectric loss due to the effective electrical conductive path established by graphene nanosheets in a local range. Moreover, the mechanical evaluation demonstrated that a considerable reinforcement was achieved for the composite films due to the strong interfaces between the graphene nanosheets and PB matrix. The introduction of graphene nanosheets not only enhanced the nucleation capability and crystallinity of PB domain but also improved the thermal stability of the composite films. In addition, the composite films showed an increase in storage modulus and a decrease in loss factors due to the incorporation of graphene nanosheets.

Inhibition of prostate cancer growth using doxorubicin assisted by ultrasound-targeted nanobubble destruction.

Ultrasound (US)-targeted microbubble destruction has been widely used as an effective drug-delivery system. However, nanobubbles (NBs) have better stability and stronger penetration than microbubbles, and drug delivery assisted by US-targeted NB destruction (UTND) still needs to be investigated. Our aim was to investigate the effect of doxorubicin (DOX) on the inhibition of prostate cancer growth under UTND. Contrast-enhanced US imaging of transplanted PC3 prostate cancer in mice showed that under a combination of 1 W/cm2 US power and a 100 Hz intermittent pulse with a “5 seconds on, 5 seconds off” mode, NBs with an average size of (485.7±33) nm were effectively destroyed within 15 minutes in the tumor location. PC3 cells and 20 tumor-bearing mice were divided into four groups: a DOX group, a DOX + NB group, a DOX + US group, and a DOX + NB + US group. The cell growth-inhibition rate and DOX concentration of xenografts in the DOX + NB + US group were highest. Based on another control group and these four groups, another 25 tumor-bearing mice were used to observe the treatment effect of nine DOX injections under UTND. The xenografts in the DOX + NB + US group decreased more obviously and had more cellular apoptosis than other groups. Finally, electron microscopy was used to estimate the cavitation effect of NBs under US irradiation in the control group, NB group, US group, and NB + US group. The results of scanning electron microscopy showed that PC3 cells in the DOX + NB + US group had more holes and significantly increased cell-surface folds. Meanwhile, transmission electric microscopy confirmed that more lanthanum nitrate particles entered the parenchymal cells in xenografts in the NB + US group compared with the other groups. This study suggested that UTND technology could be an effective method to promote drugs to function in US-irradiated sites, and the underlying mechanism may be associated with a cavitation effect.

Raltitrexed Inhibits HepG2 Cell Proliferation via G0/G1 Cell Cycle Arrest.

Raltitrexed (RTX) is an antimetabolite drug used as a chemotherapeutic agent for treating colorectal cancer, malignant mesothelioma, and gastric cancer. The antitumor capacity of RTX is attributed to its inhibitory activity on thymidylate synthase (TS), a key enzyme in the synthesis of DNA precursors. The current study is aimed at investigating the potential antitumor effects of RTX in liver cancer. Using the HepG2 cell line as an in vitro model of liver cancer, we evaluated the effects of RTX on cell proliferation employing both a WST-8 assay and a clone formation efficiency assay. In addition, we monitored the ultrastructure changes of HepG2 cells in response to RTX with transmission electric microscopy. To investigate the mechanism underlying the regulation of cell proliferation by RTX, we analyzed cell cycle using cell flow cytometry. Moreover, real-time PCR and Western blot analyses were conducted to examine expression levels of cell cycle regulatory proteins cyclin A and cyclin-dependent kinase 2 (CDK2), as well as their mediators tumor suppressor genes p53 and p16. Our results demonstrate that RTX inhibits HepG2 proliferation by arresting the cell cycle at G0/G1. This cell cycle arrest function was mediated via downregulation of cyclin A and CDK2. The observed elevated expression of p53 and p16 by RTX may contribute to the reduction of cyclin A/CDK2. Our study indicates that RTX could serve as a potential chemotherapeutic agent in the treatment of hepatocellular carcinoma.

Transport phenomenon of anormalous carriers in ferroelectric-semiconductor coupled solar cell

In recent years, a variety of new-concept solar cells have attracted the attention of many scholars. The CdS-CdTe ferroelectric-semiconductor coupled (FSC) solar cell is a novel concept of photovoltaic device that is designed with ferroelectric nano particles of S-rich CdS1-xTex, which are embedded in the light-absorbing semiconductors of Te-rich CdSyTe1-y. In our previous work, we have developed a two-step process to fabricate a nano-dipole photovoltaic device, including a thin film deposition in vacuum and high-temperature phase segregation at elevated temperature in sequence. The X-ray diffraction (XRD) and high-resolution scanning transmission electric microscopy (STEM) results confirm the formation of S-rich CdS1-xTex particles with a wurtzite structure embedded in a Te-rich CdSyTe1-y film with a zinc blend structure. The localized ferroelectric hysteretic behavior of these particles is confirmed through piezoelectric force microscopy (PFM). Meanwhile, a set of CdS-CdTe FSC devices with a symmetrical structure of ITO/FSC/ITO is fabricated. We observe not only a reasonable photovoltage output on the order of hundreds of mV but also the hysteretic behavior of photovoltage through external electric field post-fabrication. To search for direct evidence of the working mechanism of the FSC solar cell, we further study the film surface micro current distribution of the FSC thin film solar cell. In this work, we adopt the CAFM method to acquire electron distribution of the FSC thin film surface and STEM, the electron diffraction for element distribution, and crystal structure of FSC thin film. Also, Schottky solar cell of FTO/pure CdTe/metal structure which is fabricated by the same process as the FSC solar cell is used as reference sample in the CAFM analysis. In this work, we fabricate the CdS-CdTe FSC film solar cell through a radio-frequency magnetron sputtering method, whose structure is a glass/FTO/CdSTe/back contact (Cu/Au) configuration. In order to enhance the polarization of nano dipole particles in the device, an electric field bias across the FSC film is applied in the high-temperature phase segregation process. Micro-current distribution in CdS-CdTe FSC solar cell is investigated by CAFM. Grain boundaries of the FSC film are found to be non-conductive with high current corridors adjacent to them. And some small particles with diameter about 100 nm are embedded in grain boundaries (GBs) of CdTe grains. By applying positive and opposite voltage separately between measurement tip and TCO of sample, we find that the non-conductive GBs have a strong piezoelectric response, which are most likely S-rich CdS1-xTex in wurtzite structure. By contrast with pure CdTe film, the possibility that the non-conductive particles are CdCl2 residuals is excluded. We also find by STEM that many particles with sizes about 100-200 nm are embedded in FSC thin film, mostly at the GBs. The XRD results confirm that the small particles are S-rich CdS1-xTex particles with a wurtzite structure and the big grains are Te-rich CdSyTe1-y with a zinc blend structure. We could conclude reasonably that the small particles observed in CAFM image probably are S-rich CdS1-xTex:The apparent correlation between the carrier transport channel and nano-dipole material is also established. An interesting discovery from such devices is that such cells exhibit performance improvement over time in months after storage with encapsulation in ambient environment. A linear relationship between Voc and the external field strength is observed and the best conversion efficiency is improved from 11.3% to 13.2% further after 6-month storage. We believe that all these microscopic and macroscopic evidences are consistent with the FSC photovoltaic mechanism.

A novel alphaproteobacterial ectosymbiont promotes the growth of the hydrocarbon-rich green alga Botryococcus braunii.

Botryococcus braunii is a colony-forming green alga that accumulates large amounts of liquid hydrocarbons within the colony. The utilization of B. braunii for biofuel production is however hindered by its low biomass productivity. Here we describe a novel bacterial ectosymbiont (BOTRYCO-2) that confers higher biomass productivity to B. braunii. 16S rDNA analysis indicated that the sequence of BOTRYCO-2 shows low similarity (<90%) to cultured bacterial species and located BOTRYCO-2 within a phylogenetic lineage consisting of uncultured alphaproteobacterial clones. Fluorescence in situ hybridization (FISH) studies and transmission electric microscopy indicated that BOTRYCO-2 is closely associated with B. braunii colonies. Interestingly, FISH analysis of a water bloom sample also found BOTRYCO-2 bacteria in close association with cyanobacterium Microcystis aeruginosa colonies, suggesting that BOTRYCO-2 relatives have high affinity to phytoplankton colonies. A PCR survey of algal bloom samples revealed that the BOTRYCO-2 lineage is commonly found in Microcystis associated blooms. Growth experiments indicated that B. braunii Ba10 can grow faster and has a higher biomass (1.8-fold) and hydrocarbon (1.5-fold) yield in the presence of BOTRYCO-2. Additionally, BOTRYCO-2 conferred a higher biomass yield to BOT-22, one of the fastest growing strains of B. braunii. We propose the species name ‘Candidatus Phycosocius bacilliformis’ for BOTRYCO-2.

The Metastable Micro-Nanocrystals and Formation Mechanism of Rapidly Solidified Al-21Si Multi-Alloys

In the present work, rapidly solidified Al-21Si-0.8Mg-1.5Cu-0.5Mn alloys strips was prepared by melt-spinning technique. The microstructure morphology and phase structures of experimental alloy were characterized by means of scanning electron microscopy (SEM), transmission electric microscopy (TEM) and XRD technique. The results show that the grains were refined and the micro-nanocomposite structural were formed under rapid solidification. The nucleation and growth of primary silicon were suppressed and primary silicon could not deposited, meanwhile, α-Al phase was nucleated which prior to eutectic. The microstructure of the Al-21Si alloy was composed of micro-nanostructured α-Al phase and feather-needles-like eutectic α-Al+β-Si phase. The hypereutectic Al-21Si alloy showed the hypoeutectic microstructure. The rapidly solidified Al-21Si alloy microstructure formation mechanism has also been discussed.

Effect of lubricating oil additive package on the characterization of diesel particles

In this study, the effects of lubricating oil additive diesel fuel on the diesel engine emission particles characterizations, such as size distribution, morphology, nanostructure and composition was investigated on a light-duty diesel engine. Fast particle spectrum analysis was used for the determination of size distribution, and transmission electric microscopy (TEM) technique for the investigation of morphology of particles. On the other hand, the element carbon fraction can be obtained through thermogravimetric analysis (TGA). Compared with the emission particles from burning pure diesel fuel, the emission particles from burning lubricating oil additive diesel fuel have lower fractal dimension. Measurement results of the nanostructure parameters show that emission particles from burning oil additive dosed fuel have lower graphite structure than those from burning pure diesel fuel. TGA results indicate that more volatile and ash fraction were contained in the particles when oil additive was mixed into diesel. In conclusion, the oil additive may increase the nucleation mode particles and ash component. Therefore, the enhanced performance of diesel particulate filter (DPF) system may be required. Thus, the usage of oil additive should be optimized by considering the tradeoff between oil quality and particle emissions contribution.

High dielectric, dynamic mechanical and thermal properties of polyimide composite film filled with carbon-coated silver nanowires

High dielectric permittivity materials are much desirable in the electric industry. Filling polymer matrix with conductive powders to form percolative composites is one of the most promising methods to achieve high dielectric permittivity. However, they do not always provide high mechanical properties and thermal stability, which seriously limit their applications. In this study, we present the preparation of functional core–shell structured silver nanowires/polyimide (AgNWs/PI) hybrid film with high dielectric permittivity and low loss dielectric. The core–shell structure of AgNWs was characterized by transmission electric microscopy. The dynamical mechanical analysis showed that AgNWs/PI hybrid films had relative high dynamic mechanical properties with storage modules over 1 Gpa. Moreover, the hybrid films exhibited excellent thermal stability with 5 % weight-loss temperature above 500 °C. The dielectric properties of the carbon-coated AgNWs hybrid films were remarkably improved. The maximum dielectric permittivity of hybrid films is 126 at 102 Hz, which was 39 times higher than that of pure PI matrix, while the dielectric loss of that is still remained at a low value. This study showed a new method to improve the dielectric, dynamic mechanical and thermal properties of films.

Fabrication of Spirocyclic Phosphazene Epoxy-Based Nanocomposites with Graphene via Exfoliation of Graphite Platelets and Thermal Curing for Enhancement of Mechanical and Conductive Properties

Nanocomposites of a spirocyclic phosphazene epoxy (SP-epoxy) resin with graphene were prepared through the exfoliation of graphite platelets and thermal curing process. Transmission electric microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy confirmed the chemical exfoliation and following thermal reduction for the graphene. The TEM observation also demonstrated that the reduced graphene oxide, as the single- and/or few-layered stacking sheets, was homogeneously dispersed in the SP-epoxy matrix. The presence of graphene improved both the tensile and flexural properties of the nanocomposites as a result of the great surface area of graphene sheets in contact with the matrix. These nanocomposites also achieved a considerable increase in glass transition temperature, thermal decomposition temperatures, and storage modulus. It is highly emphasized that the SP-epoxy/graphene nanocomposites also presented a low percolation threshold of 0.375 vol % and achieved high electrical conductivity at a...

Enhancement of piezoelectric response of diluted Ta doped AlN

The authors have investigated the variation of microstructure and piezoelectric response of TaxAl1−xN films with Ta concentrations. The results indicate that moderate Ta doping facilitates the c-axis orientation, crystallinity and enlargement of lattice constants. When the doping content is about 5.1at.%, the c-axis orientation is optimized in the best with c constant of about 0.5086nm. The Raman spectra of TaxAl1−xN films further determine the wurtzite structure of AlN after Ta doping. The high resolution transmission electric microscopy demonstrates that the column single crystal was obtained with presence of nano distortion domains. The Ta 4f7/2 binding energy of TaxAl1−xN shows a shift toward lower binding energy side, indicating that the coordination configuration of Ta with N changed as Ta contents increased. A significant enhancement in piezoelectric response was obtained from 4.2pC/N to 8.2pC/N, which is enhanced by ca. 100%, when the Ta content arrived to 5.1at.%. The expansion of unit cell volume and the competition between Ta and Al atoms about the coordination of nitrogen atoms, which will enhance the internal nitrogen displacement under electric field, are proposed to be the main microscopic origin of the enhancement of piezoelectric response.

EFFECT OF ERK1/2 SIGNAL TRANSDUCTION PATHWAY IN VASCULAR ENDOTHELIAL CELL APOPTOSIS

ObjectivesTo explore the changes in extracellar signal-regulated protein kinase (ERK1/2) in endothelial cell senescence induced by AngiotensinII at the different time courses, and its possible molecular mechanism.MethodsHuman umbilical vein endothelial...

Experimental study on the molecular mechanism of anthraquinone cathartics in inducing melanosis coli

To explore the significance of colonic epithelial cell apoptosis and tumor necrosis factor α (TNF-α) changing in pathogenesis of melanosis coli (MC) in guinea pig and the molecular mechanism of rhubarb (Rhu) in inducing the disease, by means of using different dosages of Rhu to induce the disease. One hundred and forty-four male guinea pigs, clean grade, were randomized according to their body weight into 5 groups, the untreated normal group and the 4 Rhu groups treated, respectively, with different doses of Rhu, 3 g/kg·d for low dose (Rhu-l) group, 6 g/kg·d for moderate dose (Rhu-m) group, 12 g/kg·d for high dose (Rhu-h) group and 24 g/kg·d for super-high dose (Rhu-s) group via gastric infusion. All animals were sacrificed 60 days later, their viscera were taken for observing the pathologic and morphologic changes with HE, melanin and melatonin staining, and the apoptosis of colonic epithelial cells was detected with TUNEL stain and transmission electric microscopy. In addition, the levels of TNF-α in serum and colonic tissue were measured using ELISA and RT-PCR. The pathological changes of MC could be found by naked eye in all Rhu groups, especially apparent at caecum and proximal end of colon, but did not found in gallbladder, jejunum and ileum. In normal guinea pigs, the colonic membrane was pink in color with no apparent pigment deposition. Membranous color deepened in the Rhu groups depending on the dosage of Rhu used. MC scoring showed the highest scores revealed in the Rhu-s group (6.00±0.00), which was significantly different to those in the Rhu-l (3.86±0.69), Rhu-m (4.43±0.79) and Rhu-h groups (4.88±0.35, all P<0.05). Levels of cell apoptosis in colon and TNF-α in serum in all Rhu groups were higher than those in the normal group (P<0.01), but showed no significant difference among the Rhu groups (P>0.05). Moreover, a positive correlation was found in the degree of induced MC with apoptosis rate and TNF-α level. Rhu (anthraquinone purgatives) had apparent effect on inducing MC; its molecular mechanism is maybe to destroy intestinal mucosal barrier and advance proinflammatory factor TNF-α releasing, which leads to colonic epithelial cells apoptosis, and finally induce the change of MC due to the deposition of brown pigments, i.e. the macrophage phagocytized apoptotic body, on the colonic membrane.

Eudragit nanoparticles containing genistein: formulation, development, and bioavailability assessment

BackgroundGenistein, one of the major isoflavones, has received great attention as a phytoestrogen and potential cancer chemoprevention agent. However, the dissolution and bioavailability of genistein from solid oral preparations is low due to its poor water solubility.MethodsIn order to improve the oral bioavailability of genistein, genistein nanoparticles were prepared by the nanoprecipitation technique using Eudragit® E100 as carriers and an optimized formulation of mass ratio (genistein:Eudragit E100, 1:10). The mean particle size of genistein nanoparticles was approximately 120 nm when diluted 100 times with distilled water. The drug-loaded nanoparticles were spherical on observation by transmission electric microscopy.ResultsEncapsulation efficiency and drug loading of the genistein nanoparticles were approximately 50.61% and 5.02%, respectively. Release of drug from the genistein nanoparticles was two times greater than that from the conventional capsules. After administration of genistein suspension or genistein nanoparticles at a single dose of 100 mg/kg to fasted rats, the relative bioavailability of genistein from the nanoparticles compared with the reference suspension was 241.8%.ConclusionThese results suggested that a nanoparticle system is a potentially promising formulation for the efficient delivery of poorly water-soluble drugs by oral administration.

Microstructural Morphology and Formation Mechanism of Rapidly Solidified Al-21Si Multi-Alloys

In the present work, rapidly solidified Al-21Si-0.8Mg-1.5Cu-0.5Mn alloys strips was prepared by melt-spinning method. The microstructures, phase and morphology characteristics of the experimental alloy were characterized by means of scanning electron microscopy, transmission electric microscopy. The results show that the microstructures are changed obviously compared with conventional condition. The nucleation and growth of primary silicon are suppressed and primary silicon can not deposited, meanwhile, α-Al phase is nucleated which prior to eutectic. The microstructures of the rapidly solidified alloys are composed of primary micro-nanostructure α phase and feather-needles-like (α+Si) eutectic which set in the α phase. The mechanism of formation for microstructures of melt-spinning Al-Si alloy have also been discussed.

A Rho-kinase inhibitor, fasudil, attenuates progressive glomerulosclerosis induced by daunorubicin in rats

Accumulating evidence suggests that the small G protein Rho and its downstream effector Rho kinase may play important roles in kidney biology. The present study examined the effects of a Rho-kinase inhibitor, fasudil, on daunorubicin-induced progressive glomerulosclerosis and explored the underlying mechanism by which fasudil ameliorates glomerulosclerosis. Thirty-six male SD rats were randomly allocated into sham-operation group (sham group, n=12), unilateral nephrectomy (UNX)+daunorubicin (DRB) group (model group, n=12), UNX+DRB+Fasudil group (treatment group, n=12). Two to four weeks after the establishment of the animal model, 6 rats in each group were taken randomly for the detection of 24-h urine protein excretion. Kidney sections were examined by HE and PAS staining, immunohistochemistry and transmission electric microscopy (TEM). The expression of Rho-kinase mRNA and P27 mRNA in kidney were detected by RT-PCR. It was found that the 24-h urine protein excretion in model group was increased significantly as compared with sham group (P<0.01). But this increase was significantly suppressed by fasudil (P<0.05). At 4 week, the foot process effacement in podocytes, mesangial proliferation and ECM accumulation were observed in model group, presenting as focal segmental glomerulosclerosis. But in the treatment group, the fasudil alleviated glomerular injury, with proliferating cell nuclear antigen (PCNA)-positive cell infiltration ameliorated and the expression of P27 increased. The expression of Rho-kinase mRNA was significantly enhanced in model group and was suppressed in treatment group. Moreover, fasudil up-regulated the mRNA expression of P27. Our study demonstrated that the glomerulosclerosis was substantially ameliorated by inhibiting the expression of Rho-kinase. It is suggested that Rho-kinase pathway is involved in the renal injury and the inhibition of Rho-kinase may constitute a therapeutic strategy for the treatment of renal injury.

Clinicopathologic study of 15 splenectomy specimens of patients with hairy cell leukemia

To investigate the clinicopathologic features, diagnosis, differential diagnosis and the prognosis of hairy cell leukemia (HCL). Fifteen splenectomy specimens of HCL patients were investigated retrospectively using HE and immunohistochemistry in correlation with the follow-up information. (1) The male to female ratio was 2.75:1, age ranged from 36 to 68 years with a median of 47 years. The most consistent clinical feature at presentation was marked splenomegaly (100%). Other symptoms included anemia (80.0%), thrombocytopenia (60.0%), leucocytosis (53.3%), pancytopenia (20.0%) and the absence of B-symptom. (2) The proportion of hairy cells was (14.6 +/- 7.2)% in periphery blood and (47.3 +/- 23.8)% in bone marrow. The positive rate of TRAP assay was 62.5% in bone marrow; 85.7% for TPA test and the detection rate for RLC was 25% by transmission electric microscopy. The frequency of bone marrow involvement was 100%. (3) The average weight of 15 spleens was (3012 +/- 1974) g. The size of 6 spleens ranged from 16 cm x 10 cm x 5 cm to 32 cm x 20 cm x 14 cm. The white pulp of spleen showed a characteristic atrophy feature or even absent due to leukemic infiltration, predominantly involving the red pulp with some sinusoidal pattern. "Blood pool" change was an infrequent feature (3/15 cases). The nuclei of leukemic cells were round (13 cases) or bean-shaped (2 cases), nucleoli inconspicuous or disappeared. The abundant cytoplasm and prominent cell border resulted in a "fried egg" appearance. By immunohistochemistry, leukemic cells were positive for CD45RA, CD20, PAX-5, CD25, CD11c, Annexin A1 and cyclinD1, but negative for CD3 and CD43. (4) 13 cases (86.7%) have been followed-up and all are alive. Among them, 9 cases are living well more than 5 years and 7 more than 10 years. Splenomegaly is frequently the first manifestation of patients with HCL and occurred predominantly in the middle to elderly adults. Definite diagnosis of HCL requires a combined histological and immunohistochemical assessment of the splenectomy specimen, bone marrow biopsy and aspirate.