Spectral studies of SnO2 nanofibres prepared by electrospinning method

Tin oxide nanofibres with 100-150 nm diameter has been prepared, for the first time by calcination of poly(vinyl acetate) (PVAc)/SnO2 composite fibres prepared by electrospinning method as precursor. Scanning electron microscopic images revealed cylindrical morphology of the fibres after calcination at 600 degrees C. Both, X-ray diffraction (XRD) and Raman spectral data confirmed the presence of phase pure tetragonal rutile tin oxide after calcination process. Room temperature photoluminescence (PL) spectra of tin oxide nanofibres under excitation at 325 nm wavelength show a strong green emission at 525 nm with a band gap of 2.41 eV. FT-IR spectra confirmed the formation of pure tin oxide after calcination at 600 degrees C and complete removal of PVAc during calcination. UV-vis spectrum of the fibres showed absorption at 315 nm due to the direct electron transfer in tin oxide.

Autoimmune pancreatitis: radiologic findings in 20 patients

BACKGROUND

Autoimmune pancreatitis is a new clinical entity that is characterized by peculiar histopathologic and laboratory findings and by a dramatic clinical response to corticosteroid therapy. We evaluated the radiologic findings of autoimmune pancreatitis.

METHODS

Computed tomographic, magnetic resonance imaging, endoscopic retrograde cholangiopancreatographic, and ultrasonographic findings of 20 patients with autoimmune pancreatitis in our hospital between November 2000 and December 2003 were retrospectively reviewed regarding changes and ancillary findings in the pancreatic parenchyma, the main pancreatic duct, peripancreatic vessels, and distal common bile duct. In addition, follow-up images were reviewed for changes in any abnormality seen on the initial examinations.

RESULTS

Pancreatic parenchymal enlargement was invariably seen that was diffuse (n = 19) or focal (n = 1), with homogeneous contrast enhancement on computed tomography (n = 20) and magnetic resonance imaging (n = 15). Capsule-like rim enhancement was seen in six patients. There was focal (n = 18) or diffuse (n = 2) narrowing of the main pancreatic duct and it was usually multifocal (n = 17) in the former. Narrowing of the peripancreatic veins was seen in 14 patients. There was tapered (n = 15) or abrupt (n = 3) narrowing of the distal common bile duct in 18 patients, with contrast enhancement of the narrowed segment in eight. Invariably, changes in the pancreatic parenchyma, main pancreatic duct, peripancreatic vessels, and common bile duct were normalized on follow-up studies after steroid therapy.

CONCLUSION

In this series, common radiologic findings of autoimmune pancreatitis were (a) diffuse pancreas enlargement, (b) multifocal narrowing of the main pancreatic duct, (c) narrowing of peripancreatic veins, and (d) tapered narrowing of the distal common bile duct with frequent contrast enhancement. These findings were usually reversible with steroid therapy.

Abdominal cavernous Iymphangiomas: CT findings

Two adult patients with histopathologically proved cavernous lymphangiomas and one adult patient with lymphangiomas of strongly presumed cavernous type by cytologic and computed tomographic findings are reported. On computed tomograms, multiple, aggregated, small, and tiny cysts without a solid portion, along the lymphatic channels are characteristic computed tomographic findings for cavernous lymphangiomas.

A more persistent tolerance to islet allografts through bone marrow transplantation in minimal nonmyeloablative conditioning therapy

INTRODUCTION

Islet transplantation is a therapeutic approach to prevent diabetes complications. However, the side effects of the required lifelong immunosuppressive regimens to prevent graft rejection restrict the impact of type 1 diabetes. One strategy to overcome these limitations is tolerance induction and graft acceptance through hematopoietic chimerism. In this study we investigated whether tolerance to major histocompatibility complex (MHC) and minor-disparate islet allografts could be induced by minimal nonmyeloablative conditioning and whether more persistent donor-specific islet allografts were accepted if the grafts were implanted with simultaneous bone marrow cells.

METHODS

The donor and recipient mice were BALB/c(H-2(b)) and C57BL/6(H-2(d)), respectively. In group 1 streptozotocin-induced diabetic C57BL/6(H-2(d)) mice received only 500 islets of BALB/c(H-2(b)). Group 2 recipients conditioned with antilymphocyte serum, 100 cGy total body irradiation and cyclophosphamide were given islet cells of BALB/c(H-2(b)), but group 3 were simultaneously given 30 x 10(6) BALB/c(H-2(b)) mice BMCs and islet cells similar to group 2.

RESULTS

We obtained 5% to 6% allogeneic donor chimerism and 60% graft survival at 80 days after islet transplantation in group 3. We observed lymphocyte infiltration around the islet without destruction of endocrine cells and the presence of strong insulin/glucagon-stained cells in group 3.

CONCLUSION

This minimal nonmyeloablative conditioning therapy induced donor chimerism and immune tolerance between MHC- and minor-disparate (BALB/c-->C57BL/6) mice and long-term islet graft survival was obtained through cotransplantation of bone marrow cells.

Diagnostic accuracy of mini-mental status examination and revised hasegawa dementia scale for Alzheimer's disease

To compare the diagnostic accuracies of the Revised Hasegawa Dementia Scale (HDS-R) and Mini-Mental Status Examination (MMSE) for Alzheimer's diseases (AD), we administered them simultaneously to 82 AD patients and 82 age- and sex-matched nondemented control subjects. The area under the receiver operator curve (AUC) for AD of the HDS-R (AUC(HDS-R)) and MMSE (AUC(MMSE)) were bigger than 0.90 indicating that both tests are useful for detecting AD. However, AUC(HDS-R) (0.952) was significantly larger than that of the AUC(MMSE )(0.902) regardless of the educational level of the subjects, indicating that the HDS-R is more accurate than MMSE in diagnosing AD. Moreover, the superiority of the HDS-R (AUC(HDS-R) = 0.894) to the MMSE (AUC(MMSE) = 0.704) remained significant in mild AD patients alone, who are the focus of screening. In conclusion, the HDS-R is better than the MMSE as a screening instrument for AD.

Regulation of human resistin gene expression in cell systems: an important role of stimulatory protein 1 interaction with a common promoter polymorphic site

AIMS/HYPOTHESIS

Resistin is an adipokine that might link obesity and insulin resistance. A common polymorphism of the human resistin gene, -420C >G, is a major determinant of plasma resistin concentrations as well as resistin mRNA expression in human adipose tissue. In this study, we investigated the regulatory mechanism by which this polymorphism affects resistin expression.

METHODS

Electrophoretic mobility shift assay was performed to identify the transcription factors binding to the -420G region. Transient transfection and reporter assay were used to measure promoter activities of the resistin gene. The binding ability of stimulatory protein 1 (Sp1) in response to adipocyte differentiation or high glucose concentrations was also measured.

RESULTS

Sp1 and stimulatory protein 3 (Sp3) specifically bound to the region around -420G of the human resistin gene. Overexpression of Sp1 increased the promoter activity regardless of -420 genotypes, while the promoter activity of the -420G construct was two-fold higher than that of the -420C construct. In contrast, overexpression of Sp3 scarcely increased the promoter activity. The binding ability of Sp1 to the -420G region was increased in response to adipocyte differentiation. Mithramycin A, an inhibitor of DNA binding of Sp1, reduced the effect of high glucose on transcription induction of the resistin gene in adipocytes.

CONCLUSIONS/INTERPRETATION

These results suggest that Sp1 is an important factor regulating transcription of human resistin gene. A common polymorphism of the human resistin promoter, -420C >G, is critical for the binding of Sp1 and modulates the transcriptional activity of the resistin gene by changing the binding ability of Sp1. In addition, Sp1 may be involved in the increase of resistin expression by hyperglycaemia.

Metal removal from wastewater by bacterial sorption: kinetics and competition studies

Biosorption has distinct advantages such as high efficiency and cost-effectiveness for removal of metal ions from wastewater. However, most studies of bacterial biosorption have focused on the removal of a single metal ion from aqueous solutions, even though natural water and wastewater rarely contain only one kind of heavy metal. This study investigated competitive biosorption of Co2+, Ni2+ and Cr3+ in different combinations at various concentrations under conditions of co-existence in a synthetic wastewater system utilizing the gram-negative bacterium Pseudomonas aeruginosa. In a binary system with Co2+ and Ni2+, the presence of the same concentration of dissolved Ni2+ led to a significant decrease in the amount of Co2+ adsorbed onto cells when compared with a single Co2+ system in which Ni2+ was absent. This result is most likely due to the similar competitive affinity of these equivalent cations for sorption sites located on the cells of the bacterium. However, the presence of Cr3+ with either Co2+ or Ni2+ led to a strong reduction in the uptake of each of these bivalent ions by cells, whereas Cr3+ adsorption was unhindered. Cr3+ also significantly inhibited the adsorption of both Co2+ and Ni2+ onto cells in a ternary system involving Co2+-Ni2+-Cr3+, with the order of preferential metal uptake being Cr3+ > Co2+ approximately Ni2+. Removal efficiency of the heavy metals reached 100 % at low concentrations ([Cr3+]=[Co2+]=[Ni2+=20 microM) in a multi-metal system. The results of this study indicate that pre-determination of co-existing heavy metals in wastewater and examination of their competition for the sorption sites of biosorbents are required for the efficient removal of inorganic toxicants utilizing biosorption processes.

Measurement of nuchal skin fold thickness in the second trimester: influence of imaging angle and fetal presentation

OBJECTIVE

To assess the effect of imaging angle and fetal presentation on the measurement of nuchal skin fold thickness (NFT) in the second trimester.

METHODS

Fetal NFT was prospectively measured in 921 women at 18-21 weeks' gestation. The population was divided into two groups according to fetal presentation. Group A comprised 643 fetuses in cephalic or transverse presentation and Group B comprised 278 fetuses in breech presentation. To determine whether there was a difference in NFT depending on imaging angle, in Group A the NFT was measured on the standard axial horizontal images and then on images obtained after moving the transducer about 30 degrees toward the occiput. In Group B an assessment was made as to whether NFT changed with fetal presentation. Initial measurements were made with the fetuses in breech presentation. Repeat NFT measurements were made after 15 min in 64 fetuses that had converted to cephalic or transverse presentation. Statistical analysis was performed using a paired t-test.

RESULTS

The mean NFT on the standard horizontal image was 5.2 mm, while that on the 30 degrees occiput image was 4.0 mm. The difference was significant (P < 0.001). One hundred and twenty-three (19.1%) fetuses had a NFT greater than 6 mm on the standard image, but only two (0.3%) had an NFT of > 6 mm on the 30 degrees occiput image. There were no chromosomal or structural abnormalities in the 123 fetuses in which the NFT was > 6 mm. The mean NFT of 64 fetuses in the breech presentation was 4.4 mm, while it was 3.9 mm when they had converted to other presentations. The difference was statistically significant (P = 0.001). In breech presentation, 13/64 (20.3%) fetuses had a NFT greater than 6 mm compared to only one (1.6%) fetus in the other presentations. There were no structural or chromosomal abnormalities in any fetus with a NFT > 6 mm in either group.

CONCLUSIONS

In this study the NFT measurement varied with scan direction and fetal presentation. To avoid falsely thickened NFT measurements the scan should be directed to image the posterior surface of the occipital bone. This can be achieved by scanning from a 30 degrees occipital direction. Also, NFT is greater in fetuses in a breech presentation. Attention to these details can reduce false-positive NFT measurements.

Calcified Klatskin tumor mimicking intrahepatic stone: case report

Calcification is a relatively uncommon manifestation of malignant liver neoplasm. Calcifications in peripheral cholangiocarcinomas but not in Klatskin tumor have been reported. We present a rare case of Klatskin tumor that had dystrophic calcification mimicking a intrahepatic stone in a 65-year-old man.

Real-time compound ultrasonography: pictorial review of technology and the preliminary experience in clinical application of the abdomen

The purposes of this essay are to illustrate the technology overview and theoretical benefits of real-time compound ultrasonography (US) and to present our preliminary clinical experience in the evaluation of normal and diseased abdomens. The application of compounding principles to real-time US and its recent reintroduction into mainstream commercial systems have offered new opportunities for its clinical application to the routine examination of the abdomen. In our early preliminary experience, this technique effectively suppressed many of the US artifacts, better depicted the margin or boundary of the lesion, and increased contrast resolution or lesion conspicuity. Therefore, we believe that real-time compound US is a promising technique that may enhance the diagnostic confidence of the examination in the evaluation of normal and diseased abdomens.

Common genetic polymorphisms in the promoter of resistin gene are major determinants of plasma resistin concentrations in humans

AIMS/HYPOTHESIS

Resistin is thought to be an important link between obesity and insulin resistance. It has been suggested that genetic polymorphism in the promoter of resistin gene is a determinant of resistin mRNA expression and possibly associated with obesity and insulin resistance. In this study, we investigated the association between the genotype of resistin promoter and its plasma concentrations.

METHODS

We examined g.-537A>C and g.-420C>G polymorphisms in the resistin promoter and measured plasma resistin concentrations in Korean subjects with or without Type 2 diabetes. We also did haplotype-based promoter activity assays and the gel electrophoretic mobility shift assay.

RESULTS

The -420G and the -537A alleles, which were in linkage disequilibrium, were associated with higher plasma resistin concentrations. Individuals with haplotype A-G (-537A and -420G) had significantly higher plasma resistin concentrations than the others. Haplotype A-G had modestly increased promoter activity compared to the other haplotypes. Electrophoretic mobility shift assay showed that the -420G allele is specific for binding of nuclear proteins from adipocytes and monocytes. However, none of the two polymorphisms were associated with Type 2 diabetes or obesity in our study subjects.

CONCLUSIONS/INTERPRETATION

Polymorphisms in the promoter of resistin gene are major determinants of plasma resistin concentrations in humans.

Phonon-mediated electron-spin phase diffusion in a quantum dot

An effective spin relaxation mechanism that leads to electron spin decoherence in a quantum dot is proposed. In contrast with the common calculations of spin-flip transitions between the Kramers doublets, we take into account a process of phonon-mediated fluctuation in the electron spin preces-sion and subsequent spin phase diffusion. Specifically, we consider modulations in the longitudinal g factor and hyperfine interaction induced by the phonon-assisted transitions between the lowest electronic states. Prominent differences in the temperature and magnetic field dependence between the proposed mechanism and the spin-flip transitions are expected to facilitate its experimental verification. Numerical estimation demonstrates highly efficient spin relaxation in typical semiconductor quantum dots.

Afferent loop obstruction after gastric cancer surgery: helical CT findings

BACKGROUND

We reviewed the computed tomographic (CT) findings of afferent loop obstruction and assessed the value of helical CT in determining the underlying cause.

METHODS

Helical CT scans of 18 patients (12 men and six women; age range = 35-67, mean age = 50 years) with afferent loop obstruction were reviewed. All patients had gastric cancer. Ten patients had undergone radical subtotal gastrectomy with Billroth II gastrojejunostomy, and eight had undergone total gastrectomy with Roux-en-Y esophagojejunostomy. CT images were analyzed retrospectively, and the presumed cause of obstruction on CT was compared with surgical findings (n = 8) and clinical courses (n = 10).

RESULTS

Local recurrence (n = 15), peritoneal seeding (n = 1), internal hernia (n = 1), and adhesion (n = 1) were the presumed causes of obstruction on CT. In all eight patients who underwent a second operation, the cause of afferent loop obstruction was correctly suggested on CT (local recurrence in six patients and adhesion and internal hernia in one patient). In 10 patients who were not re-explored, the clinical findings or biopsy indicated recurrent tumor as suggested on CT.

CONCLUSION

Recurrent tumors and other potential causes of afferent loop obstruction can be correctly predicted with CT in most cases.

Induction of membrane-type matrix metalloproteinase-1 stimulates angiogenic activities of bovine aortic endothelial cells

Matrix metalloproteinases (MMPs) have been reported to play critical roles in endothelial cell migration and matrix remodeling during the angiogenic process. Among these MMPs, membrane-type MMP-1 (MT1-MMP) is an important molecule that can trigger the invasion of tumor cells by activating MMP-2 on their plasma membrane. However, the precise involvement of MT1-MMP in the angiogenic process has not been determined. To investigate the roles of the MT1-MMP by the matrix remodeling of endothelial cells, MT1-MMP expression vector was transfected into bovine aortic endothelial cells (BAECs). Increased expression of MT1-MMP in BAECs enhanced the activation of MMP-2, invasion and migration of BAECs. Moreover, the capacity of tube formation was increased in MT1-MMP transfectants. However, cotransfection with antisense MT1-MMP expression vector abolished the effects of MT1-MMP overexpression. These observations indicate that MT1-MMP is involved in the angiogenic process of endothelial cells in vitro.

A novel angiogenic factor derived from Aloe vera gel: beta-sitosterol, a plant sterol

Aloe vera gel has a beneficial effect on wound healing. Because angiogenesis is an essential process in wound healing, we hypothesized that Aloe vera gel might contain potent angiogenic compounds. Here we demonstrate that Aloe vera gel and its extracts are angiogenic on the chorioallantoic membrane (CAM) of chick embryo. Out of the three compounds purified from the final fraction of Aloe vera gel, beta-sitosterol showed a potent angiogenic activity in the CAM assay. In the presence of heparin, beta-sitosterol stimulated neovascularization in the mouse Matrigel plug assay and the motility of human umbilical vein endothelial cells in an in vitro wound migration assay. Thus beta-sitosterol is a novel plant-derived angiogenic factor which may have potential pharmaceutical applications for the management of chronic wounds.

A novel angiogenic factor derived from Aloe vera gel: beta-sitosterol, a plant sterol

Aloe vera gel has a beneficial effect on wound healing. Because angiogenesis is an essential process in wound healing, we hypothesized that Aloe vera gel might contain potent angiogenic compounds. Here we demonstrate that Aloe vera gel and its extracts are angiogenic on the chorioallantoic membrane (CAM) of chick embryo. Out of the three compounds purified from the final fraction of Aloe vera gel, beta-sitosterol showed a potent angiogenic activity in the CAM assay. In the presence of heparin, beta-sitosterol stimulated neovascularization in the mouse Matrigel plug assay and the motility of human umbilical vein endothelial cells in an in vitro wound migration assay. Thus beta-sitosterol is a novel plant-derived angiogenic factor which may have potential pharmaceutical applications for the management of chronic wounds.

Helical CT of postoperative patients with gastric carcinoma: value in evaluating surgical complications and tumor recurrence

BACKGROUND

We assessed computed tomographic (CT) features of postoperative complications and recurrent tumors in gastric cancer patients who underwent radical surgery.

METHODS

We performed a retrospective study of 397 patients who had undergone radical surgery for the treatment of gastric carcinoma and underwent postoperative CT in our institution over a 2-year period. Patients were assigned to one of two groups: group A consisted of 47 patients who underwent CT for complications in the early postoperative period, and group B consisted of 355 patients who underwent CT for evidence of tumor recurrence during the follow-up period. We classified recurrent tumors into four categories: local recurrence, lymph node metastasis, peritoneal seeding, and remote metastasis.

RESULTS

In group A, localized fluid collections or abscesses in the surgical bed were found in 38 patients (81%) and usually involved the left subphrenic area (74%) or the superior recess of the lesser sac (47%). In group B, recurrent tumors were found in 196 patients (55%). Among these, lymph node metastasis was the most common pattern (52%), followed by peritoneal seeding (44%), local recurrence (40%), and remote metastasis (37%).

CONCLUSION

CT after radical surgery for the treatment of gastric carcinoma frequently shows postoperative complications or tumor recurrence. Familiarity with the common postoperative complications and patterns of the tumor recurrence is a prerequisite to accurate interpretation of CT findings in these patients.

Contrast-enhanced dynamic ultrasonography of the liver: optimization of hepatic arterial phase in normal volunteers

BACKGROUND

To optimize hepatic arterial phase timing in contrast-enhanced dynamic ultrasonography (US) of the liver.

METHODS

Dynamic US was performed by using a microbubble-specific mode in 22 healthy volunteers after bolus injection of SH U 508A. Images were analyzed to determine whether hepatic arterial and portal venous phases could be temporally discriminated. Delay times to contrast enhancement at the hepatic artery (A(ini)) and portal vein (P(ini)) and the delay time until the signals between both vessels became inseparable (A(end)) were determined.

RESULTS

The hepatic arterial and portal venous phases could be temporally discriminated in all subjects. A(ini), P(ini), and A(end) (mean +/- standard deviation) were 11.0 +/- 2.0, 14.8 +/- 3.6, and 22.6 +/- 5.1 s, respectively.

CONCLUSION

In hepatic contrast-enhanced dynamic US, hepatic arterial phase scanning should be commenced earlier than 11 s and terminated after 23 s postinjection.

Monitoring PAH-contaminated soil using laser-induced fluorescence (LIF)

The heterogeneity and opacity of soil matrices pose considerable challenges for the quantification of soil contaminants. In order to investigate the feasibility of applying the Laser-Induced Fluorescence technique to measure contamination levels of soils, statistical analyses of contaminant levels and intensity of fluorescence were investigated in relation to soil properties. A significant correlation (R2 > 0.97) between contaminant levels and intensity of fluorescence was shown under different matrix conditions, such as moisture content and particle size distribution. Higher fluorescence intensities were obtained from soils with higher sand and moisture content. The statistical results in relation to the interaction between fluorescence intensity and matrix properties rejected the hypothesis that all properties of the matrices and contaminants had an equal influence on fluorescence. This implied that the concentrations of contaminants had the greatest contribution to the fluorescence intensity, but other variables also showed a considerable influence.

Abdominal amyloidosis: spectrum of radiological findings

Amyloidosis is a disease characterized by the deposition of fibrillar protein amyloid of beta-structure in organs or tissues. It is usually classified as either a primary disease or secondary to a co-existent condition, such as rheumatoid arthritis, tuberculosis, or neoplasm (particularly multiple myeloma or renal cell carcinoma). Amyloid protein deposition can be seen in a variety of organs though it occurs with higher frequency in the gastrointestinal tract, kidney, and heart. Amyloidosis can have a wide spectrum of manifestations in nearly every abdominal organ. Some of these, for example, multiple cystic submucosal masses of the stomach, amyloidosis of the gallbladder, and dirty soft tissue infiltration of the subcutaneous fat, have not yet been covered in the radiological literature. The combination of various imaging techniques and the identification of characteristic computed tomography (CT) hepatic features may help in the differentiation of amyloidosis from other infiltrative diseases; however, confirmative diagnosis can usually only be achieved by tissue biopsy.

Recurrent ovarian malignancy: patterns and spectrum of imaging findings

Ovarian carcinoma is the most common cause of death from a gynecologic malignancy. The most important prognostic factors are the presence and magnitude of residual or recurrent disease after therapy. Recurrent ovarian malignancy usually manifests as pelvic masses in the surgical bed, peritoneal seeding, nodal recurrence and pleuropulmonary lesions, and liver metastasis. Pelvic recurrence involves the vaginal stump, parametria, urinary bladder, and/or bowel adjacent to the surgical bed. Peritoneal seeding presents as nodules on the peritoneal surface, most commonly around the liver or cul-de-sac, and mesenteric infiltration. Pseudomyxoma peritonei is the other form of peritoneal seeding. Nodal recurrence appears as enlarged paraaortic nodes, especially at the renal hilar level. Unusual manifestations include metastasis in the extrahepatic abdominal solid organs, bone metastasis, and abdominal wall lesion involving subcutaneous fat or muscle. Familiarity with the patterns and spectrum of imaging findings of recurrent ovarian malignancy will facilitate accurate diagnosis and prompt treatment.