Improved delineation of arteries in the posterior fossa of the brain by model-based iterative reconstruction in volume-rendered 3D CT angiography.

BACKGROUND AND PURPOSE: Improved CTA delineation of arteries and unruptured aneurysms is clinically desired in the posterior fossa. We present a novel model-based iterative reconstruction that models system statistics and optics to improve CT image quality. We investigated the utility of MBIR for improving delineation of arteries in the posterior fossa on 3D brain CTA. MATERIALS AND METHODS: Using filtered back-projection with a standard kernel and MBIR, we reconstructed axial images of 0.625-mm thickness of 28 consecutive patients (14 men; mean age, 58.6 ± 14.6 years) who underwent 64-detector brain CTA. We placed regions of interest on the axial images, measured the mean CT value in the basilar artery and the value and SD in the pons and bilateral cerebellar hemispheres, and calculated the contrast-to-noise ratio of the brain arteries in the posterior fossa. Using volume-rendered CTA and a 4-point scale, 2 radiologists independently graded delineation of the BA, bilateral vertebral artery, superior cerebellar artery, and anterior and posterior inferior cerebellar arteries. We compared the results between FBP and MBIR by using paired t and Wilcoxon signed-rank tests. RESULTS: Compared with FBP, MBIR significantly improved the contrast-to-noise ratio (P < .0001) and subjective delineation of all arteries in the posterior fossa except the BA (VA, SCA, AICA, and PICA; P < .05 for all). The mean visual score by MBIR was 3.0 or higher for all those arteries except the AICA assessed by reader 1 (2.6 ± 0.7). CONCLUSIONS: With 3D brain CTA, contrast-to-noise ratio and arterial delineation of the VA, SCA, AICA, and PICA in the posterior fossa are better with MBIR than FBP.

Active bleeding in acute subarachnoid hemorrhage observed by multiphase dynamic-enhanced CT.

BACKGROUND AND PURPOSE: Acute SAH is reportedly associated with rebleeding from aneurysms, and recent advances in imaging technology allow us to visualize active bleeding in SAH cases. This study aimed to retrospectively investigate the incidence and characteristics of active bleeding in patients with spontaneous SAH by using multiphase dynamic-enhanced CT. MATERIALS AND METHODS: We retrospectively surveyed a series of patients with SAH who underwent CTP with 18-phase dynamic enhancement and confirmed the presence of extravasated contrast medium in the source image. We compared clinical features between 2 groups of patients with and without extravasation. RESULTS: Active bleeding was observed with increasing enhancement in 25.5% (13/51) of patients. All patients with extravasation were in Claassen grade 3 or 4 and WFNS grades 3, 4, or 5. The other group without extravasation included patients in all grades. A significant difference was observed in Claassen grade, WFNS grade, and increase of hematomas in follow-up CT (P < .05, for each) between the 2 groups. All CTP results of patients with extravasation were obtained within 2 hours of the onset of symptoms of SAH (P < .05). There was no significant difference in mortality at 14 days between the 2 groups (P = .128). CONCLUSIONS: A high incidence of active bleeding (25.5%) was detected by multiphase dynamic-enhanced CT in patients with acute SAH. These results indicate that an awareness of active bleeding in patients with SAH has the potential to affect the treatment strategy.

Increased migration of IgA lymphocytes to VIP nerve fibers after DSS-induced colitis.

Immunoglobulin-positive lymphocytes are present close to vasoactive intestinal polypeptide-positive (VIP(+)) nerve fibers in the lamina propria of the intestinal tract, and have an important role in mucosal defense. The number of immunoglobulin A-positive (IgA(+)) cells close to the epithelial basement membrane and nerve fibers is increased by the administration of lipopolysaccharides, which induce IgA secretion into the intestinal lumen. The relationship between immunoglobulin-positive lymphocytes and the VIP(+) nerve fibers during inflammation, such as in inflammatory bowel disease, however, is not well known. The morphological relationship between immunoglobulin-positive cells and the basement membrane or the VIP(+) nerve fibers in the colon was examined using double immunofluorescent labeling in an inflammatory bowel disease mouse model created by oral administration of dextran sodium sulfate (DSS). DSS administration induced goblet cell loss, crypt loss, intestinal epithelium deformation and infiltration of inflammatory cells in the mucosa. In the colon, the number and percentage of IgA(+) lymphocytes close to the basement membrane and the VIP(+) nerve fibers in the lamina propria increased after DSS administration, in parallel with the pathologic progress in the inflamed tissue. On the other hand, the percentage of immunoglobulin G-positive (IgG(+)) lymphocytes close to the basement membrane and the VIP(+) nerve fibers decreased, although the total number of IgG(+) lymphocytes in the lamina propria increased. We suggest that the immunoglobulin-producing lymphocytes and enteric nerve fibers in the colon normally have a close morphological relationship, and that this relationship is reinforced in a cell-specific manner during inflammation.

Refined human artificial chromosome vectors for gene therapy and animal transgenesis.

Human artificial chromosomes (HACs) have several advantages as gene therapy vectors, including stable episomal maintenance, and the ability to carry large gene inserts. We previously developed HAC vectors from the normal human chromosomes using a chromosome engineering technique. However, endogenous genes were remained in these HACs, limiting their therapeutic applications. In this study, we refined a HAC vector without endogenous genes from human chromosome 21 in homologous recombination-proficient chicken DT40 cells. The HAC was physically characterized using a transformation-associated recombination (TAR) cloning strategy followed by sequencing of TAR-bacterial artificial chromosome clones. No endogenous genes were remained in the HAC. We demonstrated that any desired gene can be cloned into the HAC using the Cre-loxP system in Chinese hamster ovary cells, or a homologous recombination system in DT40 cells. The HAC can be efficiently transferred to other type of cells including mouse ES cells via microcell-mediated chromosome transfer. The transferred HAC was stably maintained in vitro and in vivo. Furthermore, tumor cells containing a HAC carrying the suicide gene, herpes simplex virus thymidine kinase (HSV-TK), were selectively killed by ganciclovir in vitro and in vivo. Thus, this novel HAC vector may be useful not only for gene and cell therapy, but also for animal transgenesis.

Role of ultrasonography and MRI in the detection of wide intraductal component of invasive breast cancer--a prospective study.

AIM: To compare the role of ultrasound (US) and magnetic resonance imaging (MRI) in the detection of extent and direction of intraductal components around invasive breast cancer in comparison with histopathological findings. MATERIALS AND METHODS: In 60 invasive breast cancers (59 patients), US features of the intraductal components were classified as: (a) solid ductal dilatation radiating from the tumour, (b) the presence of a satellite lesion in the same segment without ductal dilatation, (c) ductal dilatation between the main tumour and the satellite lesion. The criteria for the detection of intraductal components by MRI were as follows: (a) strand-like enhancement on the margin of the main tumour, (b) satellite lesions around the main tumour, or (c) bridging enhancement between the main tumour and the satellite lesion. The direction of the intraductal components was classified as towards the nipple and towards the periphery. RESULTS: Wide intraductal components (>or=15 mm) towards the nipple were proven histopathologically in 17 of 59 (28.8%) cancers, and wide intraductal components towards the periphery were proven histopathologically in three out of 60 (5.0%) cancers. One cancer was located too close to the nipple and it was not possible to measure the intraductal component towards the nipple. US and MRI could accurately detect wide intraductal components towards the nipple in 14 and 8 cancers, respectively, out of 17 cancers. Sensitivity, specificity and accuracy for detection of wide intraductal components towards the nipple by US were 87.5, 88.3, and 88.1%, respectively. Sensitivity, specificity and accuracy for detection of wide intraductal components towards the nipple by MRI were 50, 79.1, and 72.1%, respectively. When the results of both diagnostic methods namely US and MRI were combined, sensitivity rose to 93.7%, specificity was 72.1% and accuracy was 78.0%. CONCLUSION: Although ultrasound is more sensitive than MRI in the delineation of intraductal extension towards the nipple, there is no statistically significant difference in overall accuracy between the two modalities.

Fibrocartilaginous embolism in a chondrodystrophoid breed dog.

An 8-year-old intact male Shih Tzu dog was admitted with acute-onset tetraplegia. Magnetic resonance imaging showed an abnormality of the cervical intramedullary spinal cord. Histopathological examination of a spinal biopsy confirmed the presence of intravascular cartilaginous emboli. This is the first report of an antemortem diagnosis of fibrocartilaginous embolism in a chondrodystrophoid breed dog.

Ultrasound-guided surgical drainage of face and neck abscesses.

An ultrasound-guided surgical drainage technique in which grey-scale and colour Doppler ultrasonography were combined is described. The technique was performed for eight deep subcutaneous abscesses subsequent to odontogenic infection, and provided easy detection and accurate, reliable penetration of abscesses that were difficult to locate by physical examination. Colour Doppler ultrasonography is particularly useful for differentiating blood vessels from the static space of abscesses.

Impact of respiratory syncytial virus infection as a cause of lower respiratory tract infection in children younger than 3 years of age in Japan.

BACKGROUND: Respiratory syncytial virus (RSV) is the most important viral pathogen for lower respiratory tract infection (LRI) in infants and children. An RSV-specific monoclonal antibody has been developed to provide prophylaxis against RSV associated LRI (RSV-LRI). The objective of this study was to determine the impact of RSV as a cause of LRI in children younger than 3 years of age to provide data to aide in the implementation of forthcoming prophylaxis against RSV. METHODS: We analyzed the viral etiology of LRI in hospitalized Japanese children younger than 3 years of age admitted to Shizuoka Red Cross Hospital from July, 1997 to June, 2000. RESULTS: A total of 535 patients younger than 3 years of age were hospitalized with LRI at Shizuoka Red Cross Hospital from July 1, 1997 to June 30, 2000. Of these, a positive diagnosis of RSV infection was made in 168 patients (31.4%). Most of the patients with RSV infection had been well and had had no underlying disease that was defined as risk factor of RSV infection (94.0%). The peak incidence of LRI was observed in the winter each year and the number of LRI was strongly associated with the epidemic of RSV (r=0.700, P<0.0001). The number of patients with LRI younger than 6 months of age was 116 (21.7%). Of these 116 patients younger than 6 months with LRI, 55 patients (47.4%) were confirmed to have RSV infection. The proportions of RSV infection to total LRI was greatest in early infants younger than 6 months (P<0.0001). The number of patients with which RSV infection was detected in LRI patients younger than 3 years was highest during the first five months of life and there was a dramatic decrease in incidence of RSV infection with increasing age thereafter. CONCLUSIONS: The incidence of LRI hospitalization is highly affected by RSV infection epidemic. The proportion of RSV infections among early infants younger than 6 months is greater than that of older patients. The prophylaxis against RSV will be needed to be toward early infants.

Risk factors for severe respiratory syncytial virus-associated lower respiratory tract infection in children.

BACKGROUND: Respiratory syncytial virus (RSV) is the most important cause of viral lower respiratory tract infection that can be a life-threatening disease in infants and children. This study was conducted to look for independent risk factors for severe respiratory syncytial virus-associated lower respiratory tract infection (RSV-LRI) that required oxygen supplementation or mechanical ventilation. METHODS: Medical records of patients younger than 4 years hospitalized with RSV-LRI at Shizuoka Red Cross Hospital from July 1, 1995 to June 30, 1999 were reviewed. The patients were compared using univariate and multivariate logistic regression analysis. RESULTS: A total of 157 patients were hospitalized with RSV-LRI at Shizuoka Red Cross Hospital from the study time period. Of these, 20 patients (12.7%) were diagnosed with severe RSV-LRI. Subjects younger than 3 months of age had an odds ratio (OR) of 59.9 (95% confidence interval (CI) 14.7_244.0) for the dependent variable of severe RSV-LRI (P<0.0001). Subjects with a history of congenital heart disease also had an OR of 99.2 (95% C1 8.5-1160.1) (P<0.0005). CONCLUSIONS: Infants younger than 3 months without any underlying diseases may be at high risk for severe RSV-LRI. Respiratory syncytial virus prophylaxis is needed not only for high-risk patients, but for healthy early infants.

Surfactant lavage and replacement in meconium aspiration syndrome with pulmonary hemorrhage.

We reported two case studies of meconium aspiration syndrome (MAS) with pulmonary hemorrhage in which we applied surfactant lavage and replacement. Surfactant lavage and replacement of MAS with pulmonary hemorrhage appears to be effective and safe adjunctive therapy. The relatively small replacement doses of surfactant required may be attributed to surfactant lavage followed by surfactant replacement. We suggest that surfactant lavage and replacement of MAS with pulmonary hemorrhage should be further investigated by a randomized controlled trial.

Potential role of Gab1 and phospholipase C-gamma in osmotic shock-induced glucose uptake in 3T3-L1 adipocytes.

Osmotic shock induces GLUT4 translocation and glucose uptake through a mechanism independent of PI 3-kinase, but dependent on tyrosine phosphorylation of cellular proteins. To identify the tyrosine phosphorylated proteins required for osmotic shock-stimulated glucose uptake, we examined tyrosine phosphorylation of candidate proteins, and found that the 60-80kDa species including paxillin and the 120-130kDa species including p130Cas, PYK2, FAK and Gab1 were tyrosine-phosphorylated in response to osmotic shock. Inhibition of actin polymerization by cytochalasin D significantly decreased the tyrosine phosphorylation of paxillin, p130Cas, PYK2 and FAK but not Gab1, but had no effect on 2-deoxyglucose (DOG) uptake, suggesting a role for Gab1 in osmotic shock-induced glucose transport. Also, we found that osmotic shock increases the association of phospholipase C-gamma (PLC-gamma) with Gab1 and stimulates tyrosine phosphorylation of PLC-gamma itself. The PLC inhibitor, U73122, inhibited osmotic shock-induced 2-DOG uptake. These results suggest that tyrosine phosphorylation of Gab1 and subsequent recruitment and activation of PLC-gamma may play a role in osmotic shock-induced glucose transport.

Growth hormone induces cellular insulin resistance by uncoupling phosphatidylinositol 3-kinase and its downstream signals in 3T3-L1 adipocytes.

Growth hormone (GH) is well known to induce in vivo insulin resistance. However, the molecular mechanism of GH-induced cellular insulin resistance is largely unknown. In this study, we demonstrated that chronic GH treatment of differentiated 3T3-L1 adipocytes reduces insulin-stimulated 2-deoxyglucose (DOG) uptake and activation of Akt (also known as protein kinase B), both of which are downstream effects of phosphatidylinositol (PI) 3-kinase, despite enhanced tyrosine phosphorylation of insulin receptor substrate (IRS)-1, association of IRS-1 with the p85 subunit of PI 3-kinase, and IRS-1-associated PI 3-kinase activity. In contrast, chronic GH treatment did not affect 2-DOG uptake and Akt activation induced by overexpression of a membrane-targeted form of the p110 subunit of PI 3-kinase (p110(CAAX)) or Akt activation stimulated by platelet-derived growth factor. Fractionation studies indicated that chronic GH treatment reduces insulin-stimulated translocation of Akt from the cytosol to the plasma membrane. Interestingly, chronic GH treatment increased insulin-stimulated association of IRS-1 with p85 and IRS-1-associated PI 3-kinase activity preferentially in the cytosol. These results indicate that cellular insulin resistance induced by chronic GH treatment in 3T3-L1 adipocytes is caused by uncoupling between activation of PI 3-kinase and its downstream signals, which is specific to the insulin-stimulated PI 3-kinase pathway. This effect of GH might result from the altered subcellular distribution of IRS-1-associated PI 3-kinase.

Ultrasonographic features of parathyroid carcinoma.

Although several authors have reported single cases illustrative of some ultrasonographic characteristic of parathyroid carcinoma, the value of ultrasonography for diagnosing this entity remains to be determined. The purpose of our study was to investigate the ultrasonographic features of parathyroid carcinoma in a large number of cases. We assessed the shape, contour, echogenicity, and depth-width (DW) ratio of 16 parathyroid carcinomas and 61 parathyroid adenomas. Ultrasonography showed that parathyroid carcinomas tend to be large, inhomogeneous, hypoechoic masses with lobulated contours. In contrast, parathyroid adenomas were small, homogeneous, hypoechoic masses with smooth borders. The mean (range) DW ratios for parathyroid carcinomas were 1.21 (0.91-2.5) and 0.64 (0.33-1.47) for adenomas; the difference was statistically significant (p<0.0001). The DW ratio was > or =1 in 15 (94%) of the 16 cases of carcinoma, whereas only 3 (5%) of the 61 adenomas had a similar ratio. Ultrasonographic examination is useful not only for preoperative localization but also for differentiating parathyroid carcinoma from adenoma. Parathyroid tumors with irregular margins, inhomogeneous echogenicity, and a DW ratio > or =1 are likely to be malignant.

Pioglitazone ameliorates tumor necrosis factor-alpha-induced insulin resistance by a mechanism independent of adipogenic activity of peroxisome proliferator--activated receptor-gamma.

Tumor necrosis factor (TNF)-alpha is one of the candidate mediators of insulin resistance associated with obesity, a major risk factor for the development of type 2 diabetes. The insulin resistance induced by TNF-alpha is antagonized by thiazolidinediones (TZDs), a new class of insulin-sensitizing drugs. The aim of the current study was to dissect the mechanism whereby pioglitazone, one of the TZDs, ameliorates TNF-alpha-induced insulin resistance in 3T3-L1 adipocytes. Pioglitazone restored insulin-stimulated 2-deoxyglucose (DOG) uptake, which was reduced by TNF-alpha, with concomitant restorations in tyrosine phosphorylation and protein levels of insulin receptor (IR) and insulin receptor substrate (IRS)-1, as well as association of the p85 regulatory subunit of phosphatidylinositol (PI) 3-kinase with IRS-1 and PI 3-kinase activity. Adenovirus-mediated gene transfer of either wild-type human peroxisome proliferator-activated receptor (PPAR)-gamma2 or a mutant carrying a replacement at the consensus mitogen-activated protein kinase phosphorylation site (hPPAR-gamma2-S112A) promoted adipogenesis of 3T3-L1 fibroblasts and restored TNF-alpha-induced decrease of triglyceride in adipocytes as effectively as pioglitazone. Overexpression of the PPAR-gamma proteins in TNF-alpha-treated adipocytes restored protein levels of IR/IRS-1, but did not improve insulin-stimulated tyrosine phosphorylation of IR/IRS-1 or insulin-stimulated 2-DOG uptake. These results indicate that the ability of pioglitazone to restore insulin-stimulated tyrosine phosphorylation of IR/IRS-1, which is necessary for amelioration of TNF-alpha-induced insulin resistance, may be independent of the adipogenic activity of PPAR-gamma that regulates protein levels of IR/IRS-1.

Non-invasive lobular carcinoma within a fibroadenoma, a preoperatively diagnosed case.

Breast cancer within a fibroadenoma is rare and usually diagnosed postoperatively from pathological specimens. This paper reports a 54-year-old female with non-invasive carcinoma within a fibroadenoma, diagnosed preoperatively. She underwent a medical examination and mastopathy was suspected. On physical examination a mass 2 cm in diameter was palpated in the left breast. Ultrasonography showed a mass with smooth margins and uniform internal echoes, but cytology showed malignancy. Mammography showed a round mass with distinct margins and no calcification. As fibroadenoma, diagnosed by ultrasonography and mammography, and breast cancer, diagnosed by cytology, were not consistent results several core biopsies were performed. Needle biopsy showed proliferation of atypical epithelial cells; breast cancer within a fibroadenoma was diagnosed. MRI showed a circular mass with distinct, smooth margins and in a dynamic study, the mass showed irregular staining and the presence of early staining. Left lumpectomy and dissection of the left axillary lymph nodes was performed. Histological examination showed non-invasive lobular carcinoma occurring within a fibroadenoma.

[Multiresidue analysis of organophosphorus pesticides in vegetables and fruits using dual-column GC-FPD, -NPD].

We investigated simultaneous and consecutive analytical methods for pesticide residues in large numbers of vegetable and fruit samples. Extraction of the sample with acetonitrile was followed by a salting-out step using a graduated cylinder. Co-extractives were removed by gel permeation chromatography (GPC) and the pesticide eluate was separated to 2 fractions. Firstly, the second fraction (85-125 mL) was passed through a silica-gel mini-column. After putting a Florisil mini-column before the silica-gel mini-column, the first fraction (55-85 mL) was passed through the tandem mini-columns, which were then eluted with 15 mL of 50% acetone/petroleum ether. The eluate was subjected to dual-column GC with dual FPD (P mode, column Rtx-OPPesticides) and NPD (column Rtx-200) detectors. Recoveries of 63 organophosphorus pesticides from fortified spinach, tomato, apple and strawberry, ranged from 71 to 126% with RSD values of 1-18%, except for the RSDs of omethoate, isoxathion, and pyraclofos (20% <). Detection limits of pesticides were 0.5-2 ng/g. Surveillance of pesticides in vegetables and fruits was carried out by using the present method. From 20 out of 30 samples, 15 pesticides (39 in total) were detected. The results indicated that the present method can be applied as an efficient and reliable tool for monitoring organophosphorus pesticide residues in vegetables and fruits.

Determination of sodium azide in beverages by ion chromatography.

A convenient method for determination of sodium azide in beverages using ion chromatography is described. This method combines the specificity for azide with a simple sample preparation using a bubble and trap apparatus that removes any interferences. Sodium azide in a sample was acidified, and the azide was converted to the volatile hydrazoic acid, which was trapped in 2.5 mM sodium hydroxide solution. Determination was performed by isocratic ion chromatography using suppressed conductivity detection. Calibration curves were linear for 0.5 to 20 microg/mL sodium azide and the detection limit was 0.05 microg/mL. Recoveries of sodium azide from spiked samples (10.0 microg/g) were more than 82.6%. The method was then used to analyze various beverages.

Ultrasonographic assessment for response to radiochemotherapy of metastatic cervical lymph nodes in head and neck cancer: usefulness of grey-scale and color doppler sonography.

To predict the response of lymph node metastasis to preoperative radiochemotherapy sonographically, the correlation between ultrasonographs and histologic features was retrospectively examined in 43 metastatic cervical lymph nodes from 24 patients with squamous cell carcinoma in the oral and maxillofacial region. Ultrasonographs were compared among poor-, good-, and complete-response lymph nodes. Before radiochemotherapy, hypoechoic internal echo and intranodal blood perfusion demonstrated many complete-response nodes; in contrast, most poor-response nodes showed peripheral blood perfusion and an avascular pattern, but did not have specific internal echo intensity. Complete-response nodes showed a significant reduction in their maximum and minimum diameters after radiochemotherapy. These results indicate that ultrasonography is useful for predicting the response of cervical lymph node metastasis to radiochemotherapy.