Electrostatic subframing and compressive-sensing video in transmission electron microscopy.

We present kilohertz-scale video capture rates in a transmission electron microscope, using a camera normally limited to hertz-scale acquisition. An electrostatic deflector rasters a discrete array of images over a large camera, decoupling the acquisition time per subframe from the camera readout time. Total-variation regularization allows features in overlapping subframes to be correctly placed in each frame. Moreover, the system can be operated in a compressive-sensing video mode, whereby the deflections are performed in a known pseudorandom sequence. Compressive sensing in effect performs data compression before the readout, such that the video resulting from the reconstruction can have substantially more total pixels than that were read from the camera. This allows, for example, 100 frames of video to be encoded and reconstructed using only 15 captured subframes in a single camera exposure. We demonstrate experimental tests including laser-driven melting/dewetting, sintering, and grain coarsening of nanostructured gold, with reconstructed video rates up to 10 kHz. The results exemplify the power of the technique by showing that it can be used to study the fundamentally different temporal behavior for the three different physical processes. Both sintering and coarsening exhibited self-limiting behavior, whereby the process essentially stopped even while the heating laser continued to strike the material. We attribute this to changes in laser absorption and to processes inherent to thin-film coarsening. In contrast, the dewetting proceeded at a relatively uniform rate after an initial incubation time consistent with the establishment of a steady-state temperature profile.

Electron beam dynamics in an ultrafast transmission electron microscope with Wehnelt electrode.

High temporal resolution transmission electron microscopy techniques have shown significant progress in recent years. Using photoelectron pulses induced by ultrashort laser pulses on the cathode, these methods can probe ultrafast materials processes and have revealed numerous dynamic phenomena at the nanoscale. Most recently, the technique has been implemented in standard thermionic electron microscopes that provide a flexible platform for studying material's dynamics over a wide range of spatial and temporal scales. In this study, the electron pulses in such an ultrafast transmission electron microscope are characterized in detail. The microscope is based on a thermionic gun with a Wehnelt electrode and is operated in a stroboscopic photoelectron mode. It is shown that the Wehnelt bias has a decisive influence on the temporal and energy spread of the picosecond electron pulses. Depending on the shape of the cathode and the cathode-Wehnelt distance, different emission patterns with different pulse parameters are obtained. The energy spread of the pulses is determined by space charge and Boersch effects, given by the number of electrons in a pulse. However, filtering effects due to the chromatic aberrations of the Wehnelt electrode allow the extraction of pulses with narrow energy spreads. The temporal spread is governed by electron trajectories of different length and in different electrostatic potentials. High temporal resolution is obtained by excluding shank emission from the cathode and aberration-induced halos in the emission pattern. By varying the cathode-Wehnelt gap, the Wehnelt bias, and the number of photoelectrons in a pulse, tradeoffs between energy and temporal resolution as well as beam intensity can be made as needed for experiments. Based on the characterization of the electron pulses, the optimal conditions for the operation of ultrafast TEMs with thermionic gun assembly are elaborated.

A huge retroperitoneal liposarcoma: case report.

BACKGROUND: Soft tissue sarcomas are rare and account for less than 1% of all newly diagnosed malignancies. One-third of malignant tumors arising in the retroperitoneum are sarcomas. Liposarcoma is the most common soft tissue sarcoma and retroperitoneal sarcoma. Liposarcoma accounts for at least 20% of all sarcomas in adults and up to 41% of all retroperitoneal sarcomas. Here we present the case of a huge retroperitoneal liposarcoma and a brief literature review. CASE REPORT: A 34-year-old woman was referred to our hospital from a local clinic, because of abdominal distention, pain, and palpable mass. On admission we found that her abdomen was markedly distended. Computed tomography showed a the huge left ovarian mass that occupied almost the entire abdominal cavity. The mass consisted mainly of fat, and calcified material. She was operated under the diagnosis of a huge teratoma. The tumor was located in the retroperitoneal cavity and it abutted the left adnexa. The retroperitoneal tumor, including the left adnexa was removed. The tumor measured 22 x 15 x 11 cm, and showed many histological and pathological findings. On the basis of the histopathological finding, the tumor was diagnosed as a dedifferentiated liposarcoma of the retroperitoneum. The patient is presently undergoing radiation therapy. CONCLUSION: In retroperitoneal liposarcoma, histological subtype, incomplete resection, contiguous organ resection, and older age are strongly associated with tumor-related mortality. For liposarcoma, it is necessary to customize the treatment strategy on a case-by-case basis.

Atherosclerotic carotid stenoses of apical versus body lesions in high-risk carotid stenting patients.

BACKGROUND AND PURPOSE: Different lesion locations in the atherosclerotic carotid bulb stenosis have not been clearly defined. We sought to evaluate 2 locations of carotid bulb stenosis in high-risk patients and to determine the relationship of each location to atherosclerotic risk factors and clinical features. MATERIALS AND METHODS: Atherosclerotic carotid plaques of apical versus body lesions, defined according to the area and extent of plaque involvement, were retrospectively analyzed in 200 consecutive high-risk patients who underwent carotid stent placement because of > or =50% symptomatic stenosis. We evaluated interobserver concordance and assessed each type of lesion relative to 13 atherosclerotic risk factors, mode of symptom presentation, infarct pattern, procedure-related factors, and clinical outcomes, by univariate and multivariable logistic regression analysis. RESULTS: Interobserver concordance showed good agreement for differentiating apical and body lesions (kappa = 0.745). Univariate analysis revealed that apical lesions (n = 108, 54%) were associated with pseudo-occlusion (P = .027), older age (P = .073), and alcohol intake (P = .080), whereas body lesions (n = 92, 46%) were associated with hyperlipidemia (P = .001), a wedge-shaped cortical infarct pattern (P = .057), and hyperperfusion syndrome (P = .083). Multivariable logistic regression analysis adjusted by age revealed that hyperlipidemia (P = .002; OR, 3.462; 95% CI, 1.595-7.515) and hyperperfusion (P = .026; OR, 6.727; 95% CI, 1.261-35.894) were independent predictors of body-type lesions. CONCLUSIONS: Atherosclerotic carotid bulb stenosis was found to have 2 distinct locations, body and apical. Hyperlipidemia and cortical wedge-shaped infarcts were more frequently associated with body than with apical stenosis at the time of presentation.

Laparoscopy-assisted distal gastrectomy with intracorporeal Billroth I stapled anastomosis using a hand access device for patients with gastric cancer.

BACKGROUND: Billroth I gastroduodenostomy is an anastomotic procedure used widely after gastric resection for distal gastric cancer. As laparoscopy-assisted distal gastrectomy (LADG) gains increasing popularity, various techniques of laparoscopic gastroduodenal anastomosis are being introduced. METHODS: To investigate the feasibility and benefit of their novel surgical technique of intracorporeal Billroth I stapled anastomosis using a hand access device (IBISA-HAD), the authors performed LADG using IBISA-HAD for 23 patients with distal gastric cancer and LADG using minilaparotomy Billroth I stapled anastomosis (MLBISA) for 10 patients. RESULTS: The time required for the anastomosis procedure of IBISA-HAD was 45.5 +/- 12.0 min, and the operative time, perioperative transfusion, and hospital stay were not significantly different between IBISA-HAD and MLBISA. The IBISA-HAD procedure provided a markedly enhanced vision of the stapling process, leading to less wound retraction and extension than MLBISA. CONCLUSION: The IBISA-HAD technique can provide a markedly enhanced view of the stapling procedure with the help of a current state-of-art laparoscopy system. The authors believe that this novel technique can guide an accurate laparoscopic anastomosis for the surgeon dealing with obese patients who have distal gastric cancer.

Magnetic resonance imaging of metaplastic carcinoma of the breast: sonographic and pathologic correlation.

Metaplastic carcinoma of the breast is a rare disease. We describe the MRI findings with the correlative sonographic and pathologic features of two cases. On MRI, T2-weighted images demonstrate a relatively well-defined mass with high signal intensity cystic components. Dynamic enhancement subtraction images showed an early enhancing and delayed washout peripheral rim and non-enhancing internal components. A microlobulated, isoechogenic mass with cystic components was seen sonographically, and was histopathology related to necrosis and cystic degeneration. Although these features are not unique, metaplastic carcinoma should be included in the differential diagnosis for breast masses.

Implication of co-measured platelet factor 4 in the reliability of the results of the plasma transforming growth factor-beta 1 measurement.

We examined the possible alteration of circulating transforming growth factor-beta1 (TGF-beta1) concentrations in a time-dependent fashion in human plasma. Plasma TGF-beta1 was measured three times at 2 week-intervals from each of 12 healthy participants. Platelet factor 4 (PF4) was measured in parallel with TGF-beta1 to estimate the degree of platelet degranulation. TGF-beta1 levels of the second and third plasma samples, in which PF4s were measured as < approximately 1000 IU/ml, were relatively low and fell in a narrow range. However, TGF-beta1 levels of the first samples, in most of which PF4s were > approximately 1000 IU/ml, appeared much higher and more variable than those of the second or third samples. These results indicate that the platelet degranulation accounted for the higher TGF-beta1 levels in the first samples, and thus did not support our initial assumption. We, nevertheless, could propose a useful guidance in the assessment of TGF-beta1 levels in plasma. When the PF4 level is measured as < approximately 1000 IU/ml under our assay conditions, the TGF-beta1 level in a given plasma sample might be accepted as a reliable value considering the effect of platelet degranulation on TGF-beta1 level.

Phosphatidylinositol 3-kinase regulates proliferation of RAW 264.7 macrophages.

Phosphatidylinositol 3-kinase (P13-kinase) is an enzyme that acts as a direct biochemical link between a novel phosphatidylinositol pathway and a number of proteins containing intrinsic or associated kinase activities. Here we demonstrate that wortmannin, P13-kinase inhibitor, decreases the proliferation of RAW 264.7 macrophages and that another structurally unrelated inhibitor of P13-kinase, LY294002. also inhibits the proliferation. These results indicate a possible involvement of P13-kinase in RAW 264.7 macrophages growth regulation. Wortmannin stimulation of RAW 264.7 macrophages is followed by sustained expression of the mRNA of c-fos and a transient expression of the mRNA of c-jun. We also show that the wortmannin and LY294002 induce a cell cycle arrest in asynchronously growing cells leading to an inhibition of cell proliferation after 12 h of treatment. In addition, wortmannin or LY294002 inhibited the phorbol 12-myristate 13-acetate-induced macrophages proliferation potently. These results suggest that P13-kinase plays an important role in growth regulation of RAW 264.7 macrophages and that protein kinase C is a down stream effector of P13-kinase.

Disodium cromoglycate inhibits production of immunoglobulin E.

Disodium cromoglycate (DSCG) has been shown to inhibit the release of mediators from mast cells. In the present study, the effect of DSCG on active anaphylactic reaction was studied in mice. DSCG dose-dependently inhibited the active systemic anaphylactic reaction and serum immunoglobulin (Ig)E production induced by immunization with ovalbumin, Bordetella pertussis toxin and aluminum hydroxide gel. DSCG strongly inhibited IL-4-dependent IgE production by lipopolysaccharide-stimulated murine whole spleen cells. In the case of U266 human IgE-bearing B cells, DSCG also showed an inhibitory effect on the IgE production. These results suggest that DSCG has an anti-anaphylactic activity by inhibition of IgE production from B cells.

Inhibitory action of water soluble fraction of Terminalia chebula on systemic and local anaphylaxis.

We investigated the effects of the water soluble fraction of Terminalia chebula (Combretaceae) (WFTC) on systemic and local anaphylaxis. WFTC administered 1h before compound 48/80 injection inhibited compound 48/80-induced anaphylactic shock 100% with doses of 0.01-1.0 g/kg. When WFTC was administered 5 or 10 min after compound 48/80 injection, the mortality also decreased in a dose-dependent manner. Passive cutaneous anaphylaxis was inhibited by 63.5+/-7.8% by oral administration of WFTC (1.0 g/kg). When WFTC was pretreated at concentrations ranging from 0.005 to 1.0 g/kg, the serum histamine levels were reduced in a dose-dependent manner. WFTC (0.01-1.0 mg/ml) also significantly inhibited histamine release from rat peritoneal mast cells (RPMC) by compound 48/80. However, WFTC (1.0 mg/ml) had a significant increasing effect on anti-dinitrophenyl IgE-induced tumor necrosis factor-alpha production from RPMC. These results indicate that WFTC may possess a strong antianaphylactic action.

Polymorphism of the angiotensin-converting enzyme gene in patients with cerebral infarction in Koreans.

The relationship between cerebrovascular disease and an insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene is still being debated. The frequency of the DD genotype of the ACE gene was significantly higher in subjects with than those without cerebral infarction in Japan. The aim of the present study was to assess the relationship between ACE gene polymorphism and the development of cerebral infarction in a population from Korea. We examined its possible role as a risk factor in patients with cerebral infarction. The association between ACE gene polymorphism and cerebral infarction was examined in 106 patients with cerebral infarction and 498 controls without cerebral infarction. Frequencies of the genotypes and alleles of the ACE gene were investigated. The ACE genotype was analyzed by the polymerase chain reaction (PCR). The frequency of D allele was 37.7% in patients and 39.1% in controls (chi2 = 0.128, p = 0.720). The frequencies of the genotypes of the ACE gene were II: 39.6%, ID: 45.3%, and DD: 15.1% in patients, and II: 37.1%, ID: 47.6%, and DD: 15.3% in controls (chi2 = 0.127, p = 0.721). There was no significant difference in the frequency of the DD genotype of the ACE gene, and we did not find any association between ACE polymorphism and cerebral infarction. These results indicate that ACE polymorphism is not a risk factor for the development of cerebral infarction in a Korean population.

Inhibition of heat shock-induced apoptosis by peppermint oil in astrocytes.

Exposure to environmental stresses and toxins is linked to the pathogenesis of neuropsychiatric disorders. Astrocytes, the most abundant glial-cell type in the brain, are considered to have physiological and pathological roles in neuronal activities. We have investigated whether peppermint oil inhibits heat shock-induced apoptosis of astrocytes. We found that peppermint oil inhibits the heat shock-induced apoptosis in both human astrocyte CCF-STTG1 cells and rat astrocytes. Pretreatment of the cells with peppermint oil inhibited the heat shock-induced DNA fragmentation and condensation of nuclear chromatin. Peppermint oil also inhibited the caspase-3 activation and poly-ADP-ribose polymerase fragmentation in CCF-STTG1 cells. These results suggest that peppermint oil may modulate the apoptosis of astrocytes via the activation of the caspase-3.

Nitric oxide production by high molecular weight water-soluble chitosan via nuclear factor-kappaB activation.

High molecular weight water-soluble chitosan (WSC), having an average molecular weight of 300000 Da and a degree of deacethylation over 90%, can be produced using a simple multi-step membrane separation process. In this study, the effect of WSC on the production of nitric oxide (NO) in RAW 264.7 macrophages was evaluated. Water-insoluble chitosan alone has been previously shown to exhibit in vitro stimulatory effect on macrophages NO production. However, WSC had no effect on NO production by itself. When WSC was used in combination with recombinant interferon-gamma (rIFN-gamma), there was a marked cooperative induction of NO synthesis in a dose-dependent manner. The optimal effect of WSC on NO synthesis was shown 24 h after treatment with rIFN-gamma. The increased production of NO from rIFN-gamma plus WSC-stimulated RAW 264.7 macrophages was decreased by the treatment with N(G)-monomethyl-L-arginine (N(G)MMA). The increase in NO synthesis was reflected, as an increased amounts of inducible NO synthase protein. In addition, synergy between rIFN-gamma and WSC was mainly dependent on WSC-induced tumor necrosis factor-alpha (TNF-alpha) and nuclear factor-kappaB (NF-kappaB) activation. The present results indicate that the capacity of WSC to increase NO production from rIFN-gamma-primed RAW 264.7 macrophages is the result of WSC-induced TNF-alpha secretion via the signal transduction pathway of NF-kappaB activation.

Inhibition of tumor necrosis factor-alpha-induced apoptosis by Asparagus cochinchinensis in Hep G2 cells.

A human hepatoma cell line, Hep G2 cells, is a reliable system for the study of alcohol-induced hepatotoxicity. In this study, we investigated the effect of an aqueous extract of Asparagus cochinchinensis(MERRIL) (Liliaceae) roots (ACAE) on ethanol (EtOH)-induced cytotoxicity in Hep G2 cells. ACAE (1-100 microg/ml) dose-dependently inhibited the EtOH-induced tumor necrosis factor-alpha (TNF-alpha) secretion. ACAE (1-100 microg/ml) also inhibited the EtOH and TNF-alpha-induced cytotoxicity. Furthermore, we found that ACAE inhibited the TNF-alpha-induced apoptosis of Hep G2 cells. These results suggest that ACAE may prevent the EtOH-induced cytotoxicity through inhibition of the apoptosis of Hep G2 cells.

Inhibitory effect of mast cell-mediated immediate-type allergic reactions by sulfapyridine.

We examined the effect of sulfapyridine on mast cell-mediated immediate-type allergic reactions. Sulfapyridine (1 and 10 microg/kg) significantly inhibited systemic allergic reaction induced by compound 48/80 in rats. Sulfapyridine (1 and 10 microg/kg) also inhibited significantly local mast cell-mediated immediate-type allergic reactions activated by anti-dinitrophenyl (DNP) IgE. Moreover, sulfapyridine inhibited histamine release dose-dependently in the rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-DNP IgE. When sulfapyridine was added, the level of cAMP in RPMC, transiently and significantly increased about 4-fold compared with that of basal cells. These results indicate that sulfapyridine inhibits mast cell-mediated immediate-type allergic reactions in vivo and in vitro.

Expression of 3 beta-hydroxysteroid/dehydrogenase/delta5-delta4/isomerase in the tracheal cartilage of the rat.

The enzyme complex 3beta-hydroxysteroid dehydrogenase isomerase/delta5-delta4 (3beta-HSD) is involved in the biosynthesis of all classes of active steroids. In this study, the presence of 3beta-HSD was defined in rat tracheal cartilage. The expression of the 3beta-HSD gene was examined by Northern blot analysis from 30-day-old rats. Western blot and immunohistochemical localization were also performed with antibodies raised against purified human placental 3beta-HSD to obtain further information on the expression of 3beta-HSD protein during fetal and postnatal periods of development in rat cartilage. Northern blot analysis using an oligonucleotide common to the 4 known 3beta-HSD isoforms showed 3beta-HSD mRNA corresponding to a transcript of 1.7 kb. Furthermore, a 42 KDa protein band was detected in the tracheal cartilage extracts by Western blot analysis. Immunostaining for 3beta-SD was observed in chondrocytes. The first expression was detected on the 17th day of fetal life by Western blot and immunohistochemistry. Immunoreactivity of 3beta-HSD showed a significant increase at 7 and 15 days after birth, and then remained unchanged through adulthood, in agreement with the data of the Western blot. Our results demonstrated the expression for 3beta-HSD in the tracheal cartilage at both the mRNA and protein levels during fetal life and postnatal development of the rat. These results suggest that 3beta-HSD may synthesize certain steroids which play major roles in differentiation and maintenance of function during development of rat cartilage.

Human chorionic gonadotropin induces nitric oxide synthesis by murine microglia.

This study investigated the effects of human chorionic gonadotropin (hCG) on the synthesis of nitric oxide (NO) in murine neonatal microglial cells. When hCG was used in combination with interferon-gamma (IFN-gamma), there was a marked cooperative induction of NO synthesis in a dose-dependent manner. This increase in NO synthesis was reflected as an increased amount of iNOS protein. The increase of NO synthesis by IFN-gamma-plus-hCG was associated with the increase of tumor necrosis factor-alpha (TNF-alpha) secretion and hCG-induced NO production was decreased by the treatment with anti-murine TNF-alpha neutralizing antibody. This study provides evidence that hCG activates expression of iNOS protein in murine microglial cells accompanied by NO accumulation via pathway dependent on L-arginine in the culture medium, and further offers that TNF-alpha acts on the NO synthesis from IFN-gamma-primed murine microglial cells.

Expression of protein kinase C genes in normal (+/+) and W mutant alleles (Wsh/Wsh, W/Wv) mice testes.

In the present study, we investigated the expression of mRNA of protein kinase C (PKC) isoenzymes (alpha, beta, gamma, delta, epsilon, zeta, eta, and theta) in normal (+/+) and W mutant alleles mice testes. In +/+ mice testes, abundant expression of PKCdelta and PKCtheta was observed, while other PKCs (alpha, beta, gamma, epsilon, zeta, and eta) generally were not detected by Northern blotting. The PKCdelta and PKCtheta isoenzymes demonstrated a distinctive cellular distribution when evaluated by in situ hybridization. We have previously shown that PKCdelta gene was selectively expressed in spermatid of +/+ testes. Here we show that PKCdelta gene is also present in spermatid of Wsh/Wsh mice testes and PKCtheta gene was present in interstitial cells of +/+, Wsh/Wsh, and W/Wv mice testes. These studies provide the evidence of selective cell distributions of the PKC isoenzymes and suggest that PKC has the functional significance in testes.

Inhibition of immunoglobulin E production by Poncirus trifoliata fruit extract.

Immunoglobulin E (IgE) is the principal immunoglobulin involved in immediate hypersensitivities and chronic allergic diseases. The effect of an aqueous extract of Poncirus trifoliata (L) Raf. (Rutaceae) fruits (PTFE) on in vivo and in vitro IgE production was investigated. PTFE dose-dependently inhibited the active systemic anaphylaxis and serum IgE production induced by immunization with ovalbumin, Bordetella pertussis toxin and aluminum hydroxide gel. PTFE strongly inhibited interleukin 4 (IL-4)-dependent IgE production by lipopolysaccharide-stimulated murine whole spleen cells. In the case of U266 human IgE-bearing B cells, PTFE also showed an inhibitory effect on the IgE production. These results suggest that PTFE has an anti-allergic activity by inhibition of IgE production from B cells.