A novel method of measuring hydroxyl radical-scavenging activity of antioxidants using gamma-irradiation

A new method using ESR spin trapping was proposed for measuring the scavenging activity of antioxidants for the hydroxyl (OH) radical. (-)-Epigallocatechin gallate (EGCg) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) were used as the antioxidant and spin trapping agent, respectively. The conventional method using a Fenton reaction had problems associated with the estimation of activity, because the antioxidant disturbs the system for generating OH radical by coordinating on Fe2+ and by consuming H2O2, besides scavenging the spin adduct (DMPO-OH). Intense gamma-irradiation was therefore used to generate OH radicals, and the intensity decrease in DMPO-OH after irradiation was followed to obtain the rate constant for the scavenging of DMPO-OH by EGCg. The intensities were extrapolated to zero time to estimate the quantity of DMPO-OH formed during gamma-irradiation. By using these values, the reaction rate constant between OH radical and EGCg was calculated as a ratio to that of DMPO. It was shown that this method is useful for comparing the OH radical-scavenging activity of various antioxidants.

[Preliminary trial of three-dimensional water-excitation magnetization transfer contrast MR imaging of articular cartilage]

MR images of articular cartilage were evaluated with a three-dimensional (3D) water-excitation sequence (repetition time/echo time/flip angle = 28 msec/14 msec/20 degrees) with and without on-resonance magnetization transfer contrast (MTC) pulse in-vitro and in-vivo. 3D water-excitation images with MTC pulse showed a significantly higher contrast-to-noise ratio between normal saline or joint effusion and articular cartilage than images without MTC pulse. In 2 patients with osteoarthritis of the knee, joint effusion showed higher signal intensity than cartilage (arthrogram-like effect) on 3D water-excitation MTC images. The contrast between joint effusion and articular cartilage on 3D water-excitation MTC images was similar to that on fat-suppressed 2D protondensity-weighted fast spin echo images. In conclusion, 3D water-excitation MTC imaging is a promising method by which to evaluate articular cartilage in osteoarthritis and cartilage defect with thin sections and a reasonable scan time.

Removal of inhibitory substances with recombinant fibronectin-CH-296 plates enhances the retroviral transduction efficiency of CD34(+)CD38(-) bone marrow cells

In retroviral gene transduction, the efficiency of viral infection was reduced by the proteoglycans and some other materials secreted by the producer lines. In order to remove these inhibitors we have developed the rFN-CH-296-facilitated protocol. Because the rFN-CH-296 molecule has strong ability to bind a retroviral vector, rFN-CH-296 bound plates are utilized to wash out the unbound putative inhibitors present in a virus supernatant. The gene transduction efficiencies of human CD34(+)CD38(-) BMCs with a GALV-pseudotyped vector and the rFN-CH-296-facilitated protocol were compared with the protocol without a coating plate with CH-296, the mean gene transduction efficiencies being found to be 95.5 and 71.1%, respectively.

7Li 2D CSI of human brain on a clinical scanner

Lithium salts have been widely used in the treatment of mood disorders, but the mechanism of action is still not clear. In this work, a methodology for two-dimensional Lithium-7 imaging on clinical systems is presented. The data were acquired using a phosphorus volume head coil that was re-tuned for the Lithium-7 frequency. A spectroscopic sequence was used to acquire the free induction decay (FID) after volume excitation using a hard pulse. The results obtained on the head of patients undergoing lithium treatment (n = 7, 0.6 mEq/l average serum level) demonstrate that images of adequate signal to noise ratio (100:1) can be obtained in acceptable imaging times (55 min) using the proposed methodology. The distribution of 7Li appears uniform in the brains of the patients studied.

Spin-trapping study on the hydroxyl radical formed from a tea catechin-Cu(II) system

A spin-trapping method was applied to examine the formation of the hydroxyl (OH) radical from a tea catechin-Cu(II) system to elucidate a previous result that some tea catechin-Cu(II) systems induced DNA scission. Three tea catechins, (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCg) and (-)-epicatechin (EC), were used. The spin-trapping agent, 5,5'-dimethyl-pyrroline-1-oxide (DMPO), was dissolved in a pH 9 phosphate buffer solution, then a catechin and Cu(II) were added in that order, and the ESR spectral change was monitored for one hour. The order of adding the catechin and Cu(II) was then reversed, and the ESR spectral change was again monitored to examine the coordinating activity of each catechin toward the Cu(II) ion and the effect on OH radical generation. The intensity changes of the spin adducts, DMPO-OH, DMPO-CH3 and DMPO-H, were analyzed, the results suggesting that the OH radical generated in the system decomposed DMPO, resulting in the formation of DMPO-CH3 and DMPO-H. The results show that EGC formed a stable complex with Cu(II) and generated the OH radical. EGCg seemed to have this activity, but the OH radical that was generated was scavenged by the gallate group existing in the complex. EC did not show strong coordinating and OH-generating activities. These characteristics of the three catechins are consistent with the results shown for DNA scission.

Preoperative intradermal acupuncture reduces postoperative pain, nausea and vomiting, analgesic requirement, and sympathoadrenal responses

BACKGROUND

In a controlled and double-blind study, the authors tested the hypothesis that preoperative insertion of intradermal needles at acupoints 2.5 cm from the spinal vertebrae (bladder meridian) provide satisfactory postoperative analgesia.

METHODS

The authors enrolled patients scheduled for elective upper and lower abdominal surgery. Before anesthesia, patients undergoing each type of surgery were randomly assigned to one of two groups: acupuncture (n = 50 and n = 39 for upper and lower abdominal surgery, respectively) or control (n = 48 and n = 38 for upper and lower abdominal surgery, respectively). In the acupuncture group, intradermal needles were inserted to the left and right of bladder meridian 18-24 and 20-26 in upper and lower abdominal surgery before induction of anesthesia, respectively. Postoperative analgesia was maintained with epidural morphine and bolus doses of intravenous morphine. Consumption of intravenous morphine was recorded. Incisional pain at rest and during coughing and deep visceral pain were recorded during recovery and for 4 days thereafter on a four-point verbal rating scale. We also evaluated time-dependent changes in plasma concentrations of cortisol and catecholamines.

RESULTS

Starting from the recovery room, intradermal acupuncture increased the fraction of patients with good pain relief as compared with the control (P < 0.05). Consumption of supplemental intravenous morphine was reduced 50%, and the incidence of postoperative nausea was reduced 20-30% in the acupuncture patients who had undergone either upper or lower abdominal surgery (P < 0.01). Plasma cortisol and epinephrine concentrations were reduced 30-50% in the acupuncture group during recovery and on the first postoperative day (P < 0.01).

CONCLUSION

Preoperative insertion of intradermal needles reduces postoperative pain, the analgesic requirement, and opioid-related side effects after both upper and lower abdominal surgery. Acupuncture analgesia also reduces the activation of the sympathoadrenal system that normally accompanies surgery.

Genetic alteration of the beta-catenin gene (CTNNB1) in human lung cancer and malignant mesothelioma and identification of a new 3p21.3 homozygous deletion

The beta-catenin gene (CTNNB1) has been shown to be genetically mutated in various human malignancies. To determine whether the beta-catenin gene is responsible for oncogenesis in thoracic malignancies, we searched for the mutation in 166 lung cancers (90 primary tumors and 76 cell lines), one blastoma and 10 malignant mesotheliomas (two primary tumors and eight cell lines). Among the lung cancers, including 43 small cell lung cancers (SCLCs) and 123 non-small cell lung cancers (NSCLCs), we identified four alterations in exon 3, which is the target region of mutation for stabilizing beta-catenin. One primary adenocarcinoma had a somatic mutation from C to G, leading to an amino acid substitution from Ser to Cys at codon 37. Among the cell lines, SCLC NCI-H1092 had a mutation from A to G, leading to an Asp to Gly substitution at codon 6, NSCLC HCC15 had a mutation from C to T, leading to a Ser to Phe substitution at codon 45, and NSCLC NCI-H358 had a mutation from A to G, leading to a Thr to Ala substitution at codon 75. One blastoma also had a somatic mutation from C to G, leading to a Ser to Cys substitution at codon 37. Among the 10 malignant mesotheliomas, we identified a homozygous deletion in the NCI-H28 cell line. Cloning of the rearranged fragment from NCI-H28 indicated that all the exons except exon 1 of the beta-catenin gene are deleted and that the deletion junction is 13 kb downstream from exon 1. Furthermore, Northern blot analysis of 26 lung cancer and eight mesothelioma cell line RNAs detected ubiquitous expression of the beta-catenin messages except NCI-H28, although Western blot analysis showed that relatively less amounts of protein products were expressed in some of lung cancer cell lines. Our findings suggest that the beta-catenin gene is infrequently mutated in lung cancer and that the NCI-H28 homozygous deletion of the beta-catenin gene might indicate the possibility of a new tumor suppressor gene residing in this region at 3p21.3, where various types of human cancers show frequent allelic loss.

A comparison of the relaxant effects of olprinone and aminophylline on methacholine-induced bronchoconstriction in dogs

IV aminophylline, a nonselective phosphodiesterase (PDE) inhibitor, is often used to treat an asthma attack during anesthesia. However, in some instances, aminophylline-resistant attacks are observed. Selective PDE3 inhibitors are now clinically available and have been reported to produce bronchodilation. Thus, we compared the relaxant effects of olprinone, a novel PDE3 inhibitor, and aminophylline on methacholine-induced bronchoconstriction. Dogs were anesthetized with pentobarbital. Bronchoconstriction was elicited with methacholine (0.5 microg/kg + 5.0 microg. kg(-1). min(-1)) and assessed as percentage of changes in the bronchial cross-sectional area (BCA; basal = 100%) monitored by bronchoscope. Initially, the relaxant effects of olprinone (n = 8; 0-1000 microg/kg) and aminophylline (n = 8; 0-50 mg/kg) were compared. The bronchial cross-sectional areas were assessed before and 30 min after methacholine infusion began and 5 min after each dose of olprinone or aminophylline. We then determined whether propranolol (0.4 mg/kg) reversed the relaxation induced by olprinone (1000 microg/kg) and aminophylline (50 mg/kg). Olprinone and aminophylline dose-dependently antagonized bronchoconstriction by 56.2% +/- 21.3% (SD) and 68.0% +/- 30.3% with -log 50% effective dose (mean) of 4.80 +/- 0.38 (15.8) microg/kg and 1.96 +/- 0.42 (10.9) mg/kg, respectively. Aminophylline 50 mg/kg significantly increased plasma epinephrine, whereas olprinone did not. In addition, propranolol significantly reduced aminophylline-induced relaxation, but not olprinone-induced relaxation. Therefore, the relaxant effects of olprinone are independent of plasma epinephrine, whereas aminophylline effects may partially result from increased circulating concentrations of epinephrine.

IMPLICATIONS

We compared the relaxant effects of olprinone and aminophylline on methacholine-induced bronchoconstriction in dogs. The relaxant effects of olprinone are independent of plasma epinephrine, whereas the aminophylline effects may be partly caused by an increase in plasma epinephrine.

Sonic hedgehog facilitates dopamine differentiation in the presence of a mesencephalic glial cell line

The aim of this study was to establish a cellular system to investigate the requirement for cell surface and diffusible molecules in the differentiation of fetal mesencephalic cells toward the dopamine lineage. Toward this end, we immortalized rat embryonic day 14 (E14) mesencephalon with a regulatable retroviral vector encoding v-myc. The stably transduced cells were pooled and designated as VME14 cells. VME14 cells proliferated rapidly, stopped proliferating, extended processes, and expressed GFAP after suppression of the v-myc expression with tetracycline, suggesting that VME14 cells differentiated into glial cells. Dissociated cells derived from the E11 rat mesencephalon gave rise to only a small number of tyrosine hydroxylase (TH)-positive neurons. However, when grown on a monolayer of the differentiated VME14 cells, a significantly higher number of cells differentiated into TH-positive neurons. VME14 cells were transduced with the secreted N-terminal cleavage product of the Sonic hedgehog gene (SHH-N), an inducer of mesencephalic dopaminergic neurons. This monoclonal, SHH-N-overexpressing cell line further enhanced dopaminergic differentiation of E11 rat mesencephalon cells. Thus, SHH-N and signals derived from fetal mesencephalic glia act cooperatively to facilitate dopaminergic differentiation. These fetal mesencephalon-derived cell lines will provide tools for the study of signals involved in dopaminergic differentiation.

Transsphenoidal "cross court" approach using a slightly modified speculum to reach pituitary adenomas with lateral growth

BACKGROUND

The purpose of this study was to evaluate the usefulness of an oblique "cross court" transsphenoidal approach using a speculum with slightly modified projections for pituitary adenomas showing lateral extension.

METHOD

The projection of the speculum on the side of the cavernous lesion was shortened by 5 mm. The tip of the longer projection was placed in the sphenoid sinus, while the end of the shorter projection was placed on the concha sphenoidalis. An oblique transsphenoidal view was then easily obtained by opening the speculum. The contralateral nasal incisura had to be widened in some cases to achieve a more oblique view.

FINDINGS

Twenty-eight patients diagnosed with pituitary adenoma showing lateral growth underwent adenomectomy under direct observation of the medial portion of the cavernous sinus using this approach. Postoperative normalization of hyperendocrinopathy or gross total removal of the tumour was achieved in the majority of patients.

INTERPRETATION

An oblique transsphenoidal approach using this speculum and contralateral minor maxillary osteotomy afforded a direct view of the medial cavernous sinus, sufficient for the removal of adenomas showing minor to moderate lateral growth.

Induction of plant gp91 phox homolog by fungal cell wall, arachidonic acid, and salicylic acid in potato

The oxidative burst has been suggested to be a primary event responsible for triggering the cascade of defense responses in various plant species against infection with avirulent pathogens or pathogen-derived elicitors. The molecular mechanisms of rapid production of active oxygen species (AOS), however, are not well known. We isolated homologs of gp91 phox, a plasma membrane protein of the neutrophil NADPH oxidase, from a potato cDNA library. Molecular cloning of the cDNA showed that there are two isogenes, designated StrbohA and StrbohB, respectively. The RNA gel blot analyses showed that StrbohA was constitutively expressed at a low level, whereas StrbohB was induced by hyphal wall components (HWC elicitor) from Phytophthora infestans in potato tubers. Treatment of potato tubers with HWC elicitor caused a rapid but weak transient accumulation of H2O2 (phase I), followed by a massive oxidative burst 6 to 9 h after treatment (phase II). Diphenylene iodonium (DPI), an inhibitor of the neutrophil NADPH oxidase, blocked both bursts, whereas pretreatment of the protein synthesis inhibitor cycloheximide with the tuber abolished only the second burst. These results suggest that the expression of StrbohA and StrbohB contributes to phase I and II bursts, respectively. The same is true for arachidonic acid, a lipid component of P. infestans-stimulated biphasic oxidative burst, whereas an endogenous signaling molecule, salicylic acid, only induced a weak phase II burst. Both molecules induced the StrbohB expression, which is in agreement with the second burst. To characterize the signal transduction pathway leading to the oxidative burst, we examined the role of protein phosphorylation in HWC-stimulated StrbohB gene expression. K252a and staurosporine, two protein kinase inhibitors, blocked the transcript accumulation. Two inhibitors of extracellular Ca2+ movement, however, did not abolish the transcript accumulation of StrbohB, suggesting that certain calcium-independent protein kinases are involved in the process of StrbohB gene expression. Additionally, we examined a causal relationship between the oxidative burst and expression of defense genes induced by the HWC elicitor. The transcript accumulation of genes related to sesquiterpenoid phytoalexin synthesis (lubimin and rishitin) and phenylpropanoid pathway was inhibited slightly by the DPI treatment, suggesting that the oxidative burst is not essential to activate these genes. Interestingly, the concomitant presence of DPI with the elicitor resulted in an increase in lubimin accumulation and a decrease in rishitin accumulation. Because it is known that lubimin is metabolized into rishitin via oxylubimin, we propose that AOS mediates the synthesis of rishitin from lubimin.

Epigenetic silencing of PEG3 gene expression in human glioma cell lines

Genomic imprinting, the phenomenon in which alleles of genes are expressed differentially depending on their parental origins, has important consequences for mammalian development, and disturbance of normal imprinting leads to abnormal embryogenesis and some inherited diseases and is also associated with various cancers. In the context of screening for novel imprinted genes on human chromosome 19q13.4 with mouse A9 hybrids, we identified a maternal allele-specific methylated CpG island in exon 1 of paternally expressed imprinted gene 3 (PEG3), a gene that exhibits paternal allele-specific expression. Because PEG3 expression is downregulated in some gliomas and glioma cell lines, despite high-level expression in normal brain tissues, we investigated whether the loss of PEG3 expression is related to epigenetic modifications involving DNA methylation. We found monoallelic expression of PEG3 in all normal brain tissues examined and five of nine glioma cell lines that had both unmethylated and methylated alleles; the remaining four glioma cell lines exhibited gain of imprinting with hypermethylated alleles. In addition, treatment of glioma cell lines with the DNA demethylating agent 5-aza-2'-deoxycytidine reversed the silencing of PEG3 biallelically. In this article, we report that the epigenetic silencing of PEG3 expression in glioma cell lines depends on aberrant DNA methylation of an exonic CpG island, suggesting that PEG3 contributes to glioma carcinogenesis in certain cases.

Bronchoconstrictive and relaxant effects of lidocaine on the airway in dogs

OBJECTIVE

Intravenous lidocaine commonly is used to treat ventricular arrhythmias and to attenuate reflex airway constriction and intracranial pressure elevation during airway manipulation in intensive care units. There is much controversy as to the actions of lidocaine on the airway, so the aim of this study was to compare, in detail, the actions of lidocaine with those of bupivacaine and procaine on airway caliber and the associated changes in plasma catecholamine concentrations in the dog.

DESIGN

Prospective, randomized, controlled experimental in vivo and in vitro study.

SETTING

A university research laboratory.

SUBJECTS

Mongrel dogs.

INTERVENTIONS

In the first experiment, we evaluated the effects of intravenous local anesthetics--lidocaine 0-10 mg/kg (n = 7), bupivacaine 0-2.5 mg/kg (n = 7), or procaine 0-20 mg/kg (n = 7)--on basal airway tone. In second experiment, histamine (10 microg/kg + 500 microg x kg(-1) x hr(-1), n = 6), serotonin (10 microg/kg + 500 microg x kg(-1) x hr(-1), n = 7), and methacholine (0.5 microg/kg + 300 microg x kg(-1) x hr(-1), n = 7) were infused to determine the effects of lidocaine (0-10 mg/kg) on agonist-induced bronchoconstriction. In addition, the actions of lidocaine on vagal nerve stimulation were examined (n = 7).

MEASUREMENTS AND MAIN RESULTS

Bronchial cross-sectional area at the third bronchial bifurcation of dogs was monitored continuously through a fiberoptic bronchoscope. In the first experiment, all local anesthetics produced a dose-dependent decrease in basal bronchial cross-sectional area. In the second experiment, lidocaine significantly potentiated histamine and serotonin-induced bronchoconstriction. In contrast, lidocaine antagonized methacholine- and vagal nerve stimulation-induced bronchoconstriction.

CONCLUSION

We have clearly demonstrated that lidocaine may produce direct bronchoconstriction and worsen some agonist-induced bronchoconstriction, but it prevents reflex airway constriction. Therefore, we suggest that this agent be used with caution in asthmatics.

Epiplakin, a novel member of the Plakin family originally identified as a 450-kDa human epidermal autoantigen. Structure and tissue localization

A 450-kDa human epidermal autoantigen was originally identified as a protein that reacted with the serum from an individual with a subepidermal blistering disease. Molecular cloning of this protein has now shown that it contains 5065 amino acids and has a molecular mass of 552 kDa. As reported previously this protein, which we call epiplakin, belongs to the plakin family, but it has some very unusual features. Epiplakin has 13 domains that are homologous to the B domain in the COOH-terminal region of desmoplakin. The last five of these B domains, together with their associated linker regions, are particularly strongly conserved. However, epiplakin lacks a coiled-coil rod domain and an amino-terminal domain, both of which are found in all other known members of the plakin family. Furthermore, no dimerization motif was found in the sequence. Thus, it is likely that epiplakin exists in vivo as a single-chain structure. Epitope mapping experiments showed that the original patient's serum recognized a sequence unique to epiplakin, which was not found in plectin. Immunofluorescence staining revealed the presence of epiplakin in whole sheets of epidermis and esophagus, in glandular cells of eccrine sweat and parotid glands and in mucous epithelial cells in the stomach and colon.

Spasmolytic effect of magnesium sulfate on serotonin-induced pulmonary hypertension and bronchoconstriction in dogs

BACKGROUND

Magnesium (Mg2+) has relaxant effects on histamine-induced bronchoconstriction. In addition, Mg2+ has been reported to reduce vascular smooth muscle tone and be clinically useful for treatment of persistent pulmonary hypertension of the newborn. In this study, we evaluated the relaxant effect of Mg2+ on serotonin (5HT)-induced bronchoconstriction and pulmonary hypertension.

METHODS

Seven mongrel dogs were anesthetized with pentobarbital (30 mg x kg(-1) + 2 mg x kg(-1) x h(-1)) and paralyzed by pancuronium (0.2 mg x kg(-1) x h(-1)). Bronchoconstriction and pulmonary hypertension were elicited with 5HT (10 microg x kg(-1) + 1 mg x kg(-1) x h(-1)). Airway caliber was evaluated by changes in bronchial cross-sectional area (BCA) of the 3rd bronchial bifurcation measured by a fiberoptic bronchoscope method as previously reported. Pulmonary hypertension was assessed by changes in pulmonary vascular resistance (PVR). The BCA and PVR were expressed as per cent of the basal level. Thirty minutes after start of 5HT infusion, magnesium sulfate (MgSO4): 0 (saline), 1, 10, 100 and 1000 micromol x kg(-1) was given i.v.. Arterial blood was also collected to measure plasma level of Mg2+ and catecholamines.

RESULTS

5HT increased %PVR to 163+/-25% and decreased % BCA by 39.2+/-4.5%. Plasma level of Mg2+ following MgSO4 1000 micromol x kg(-1) i.v. exceeded its toxic level. The ED50s of MgSO4 (dose producing 50% relaxation of maximal constriction) was 47.8 micromol x kg(-1) and 1.09 mmol x kg(-1) for pulmonary hypertension and bronchoconstriction, respectively. The ratio of %PVR to %SVR was about 1.0 after MgSO4 0-100 micromol x kg(-1) i.v., although the ratio significantly increased after 1000 micromol x kg(-1) i.v..

CONCLUSION

In dogs, 5HT-induced pulmonary hypertension but not bronchoconstriction was significantly reduced by an iv bolus of MgSO4, resulting in a plasma concentration within the assumed therapeutic level.

[A case of juvenile pilocytic astrocytoma with unusual neuroimaging features]

We present a case of cerebellar juvenile pilocytic astrocytoma(JPA) with unusual neuroimaging features. The patient was a 14-year-old male who suffered from chronic headaches for a couple of weeks. Plain craniogram showed a decalcification and bulging of the occipital bone. Computed tomography(CT) scans demonstrated low density multiple components with small calcifications in the right cerebellar hemisphere extending to the left. These calcifications were found at the margin of these multi-lobular components. Magnetic resonance imaging(MRI) revealed iso or low intensity on T1 weighted image, and slightly high intensity on T2 weighted image. The lesion indicated more heterogeneous and higher intensity than brain parenchyma on FLAIR imaging, and remarkable higher intensity than brain parenchyma with some small low intensity areas on diffusion weighted imaging. He underwent the complete resection except for the cranial tissue surrounding the pons. Histologic diagnosis was juvenile pilocytic astrocytoma, because of biphasic pattern of bipolar cells and a number of Rosenthal fibers. Generally JPA has sharp and smooth demarcated cysts with well-enhanced mural nodule. It was difficult to diagnose the presented tumor as JPA before operation, since its unusual neuroimaging resembled both dermoid and high grade gliomas.

ESR imaging on a solid-tumor-bearing mouse using spin-labeled dextran

Imaging of a tumor with ESR was tried using two different types of spin probes, a low molecular weight spin probe, CPROXYL, and a polymer spin probe, TEMPO-DX. Spin probes were administered to a mouse bearing a solid tumor that was a transplanted Ehrlich's ascites carcinoma in the back, using two methods, conventional intraperitoneal injection and continuous intravenous injection with a micro-feeder. First, the accumulation of the probe was examined by X-band ESR. CPROXYL, which was administered to a mouse intraperitoneally, was exclusively retained in urine, showing that it was rapidly excreted into the bladder, while TEMPO-DX was absorbed from the peritoneal cavity with difficulty to the vessel. Using continuous intravenous injection, CPROXYL was also rapidly excreted, but it was confirmed that TEMPO-DX concentrated in tumor tissue because it has a long half-life in vivo. In addition, measurement of ESR imaging was done to measure the distribution of spin probes with continuous intravenous injection. The strongest spot of CPROXYL was observed on ESR images, showing the accumulation at the bladder, while the spot of TEMPO-DX was observed in the solid tumor of the back of the mouse. These results suggest that TEMPO-DX could stay much longer than a low molecular weight spin probe in vivo and concentrate at the tumor. TEMPO-DX may be useful for developing specific ESR imaging agents for tumor.

Evaluation of the vestibular aqueduct in vestibulocochlear disorders by magnetic resonance imaging

The visibility of the vestibular aqueduct (VA) was examined using magnetic resonance imaging (MRI) in 95 patients: 15 patients with Meniere's disease, 4 with vestibular Meniere's disease, 4 with cochlear Meniere's disease and 72 patients with other vestibular and/or cochlear disorders. In order to visualize the VA, the T2-weighted image (T2WI) and the proton-density weighted image (PDWI) were obtained in the sagittal plane with a head coil. The visibility of the VA was classified into 4 grades, i.e. grade 0 (not visible), grade 1 (partially visible with PDWI), grade 2 (partially visible with T2WI) and grade 3 (clearly visible with T2WI). The visibility of the VA was significantly lower bilaterally in Meniere's disease, vestibular Meniere's disease, cochlear Meniere's disease and idiopathic bilateral sensorineural hearing loss (IBSNHL) than in the other diseases. The differences among Meniere's disease, vestibular Meniere's disease and cochlear Meniere's disease were not significant. The significance of decreased visibility in IBSNHL is unknown so far. The VA studies using MRI strongly suggest that the pathogenesis of Meniere's disease, vestibular Meniere's disease, cochlear Meniere's disease and IBSNHL is, at least in part, related to the findings of the VA.

Large-scale evaluation of imprinting status in the Prader-Willi syndrome region: an imprinted direct repeat cluster resembling small nucleolar RNA genes

Loss of paternal gene expression at the imprinted domain on proximal human chromosome 15 causes Prader-Willi syndrome (PWS), a complex multiple-anomaly disorder involving variable mental retardation, hyperphasia leading to obesity and infantile hypotonia with failure to thrive. Although numerous paternally expressed transcripts have been identified that reside in the candidate region, the individual contributions to the development of PWS have not been firmly established. Recent studies of mouse models carrying a cytogenetic deletion suggest that paternal deficiency of the SNRPN-IPW interval is critical for perinatal lethality of potential relevance to PWS. Here we determined the allelic expression profiles of a total of 118 cDNA clones using monochromosomal hybrids retaining either a paternal or maternal human chromosome 15. Our results demonstrated a preponderance of unusual transcripts lacking protein-coding potential that were expressed exclusively from the paternal copy of the critical interval. This interval was also found to encompass a large direct repeat (DR) cluster displaying a potentially active chromatin conformation of paternal origin, as suggested by enhanced sensitivity to nuclease digestion. Database searches revealed an unexpected organization of tandemly repeated consensus elements, all of which possessed well-defined box C and D sequences characteristic of small nucleolar RNAs (snoRNAs). Southern blot analysis further demonstrated a considerable degree of phylogenetic conservation of the DR locus in the genomes of all mammalian species tested, but not in chicken, Xenopus and Drosophila. These findings imply a potential direct contribution of the DR locus, representing a cluster of multiple snoRNA genes, to certain phenotypic features of PWS.

Differential expression of two exons of the alpha1(XI) collagen gene (Col11a1) in the mouse embryo

The amino terminal domain of collagen XI has a unique structure, which is believed to participate in the regulation of matrix assembly. Interestingly, several distinct isoforms of the amino terminal domain of alpha1(XI) and alpha2(XI) collagen chains exist as a result of alternative splicing. Here we report the analysis of the alternative splicing pattern of the mouse alpha1(XI) collagen gene (Col11a1). Like other vertebrate species, the mutually exclusive expression of exons 6A and 6B of Col11a1 results in the inclusion in the alpha1 chain of either an acidic peptide (pI 3.14) or a basic peptide (pI 11.66). Expression of these two exons was monitored in several tissues of the 16.5-day mouse embryo by in situ hybridization and immunohistochemistry, with exon-specific cDNA probes and peptide-specific antibodies, respectively. The results documented that isoforms containing the exon 6B-encoded peptide accumulate predominantly in the vertebrae, skeletal muscles and intestinal epithelium. By contrast, exon 6A products were found to be most abundant in the smooth muscle cells of the intestine, aorta and lung. The results using in situ hybridization confirmed those using immunohistochemistry. Albeit correlative, the evidence suggests distinct contributions of the two peptides to the differential assembly of tissue-specific matrices.

[A case of convexity meningioma en plaque]

We present a case of convexity meningioma en plaque (MEP). A 51-year-old male occasionally suffering from right parietalgia and numbness of left upper limb. An intracranial abnormal mass was pointed out incidentally by the brain check up. Computed tomographic (CT) scans demonstrated a hyperostosis and an enhanced abnormal mass at the right front-parietal region. Magnetic resonant images (MRI) revealed a carpet like tumor extended along the dura mater. Cerebral angiography disclosed feedings from parietal branches of right middle meningeal artery and superficial temporal artery. The tumor was removed subtotally with adjacent dura mater, leaving the portion of close adhesion to the brain parenchyma. Histologic diagnosis was transitional meningioma. Immunohistological stainings showed a high staining index (6.9%) of MIB-1 (Ki-69 antigen) and high expression of metalloproteinase-9 (MMP-9), especially along the dura mater. Convexity MEP is so rare that we review previous reported cases of convexity MEP, and discuss the clinicopathologic features on that.

Embryonic expression of type XIX collagen is transient and confined to muscle cells

Type XIX collagen is a poorly characterized extracellular matrix component thought to be involved in the formation of specialized basement membrane zones. Here we examined the developmental expression of the mouse gene (Col19a1) by in situ hybridization. Col19a1 expression during embryogenesis commences at approximately E9.5 in the myotome and with a pattern that closely follows the myogenic regulatory factor myf-5. Like myf-5, Col19a1 transcription gradually decreases in differentiating skeletal muscle progenitors and concomitantly to increased myogenin gene expression. Transient expression of Col19a1 in muscular tissues is confined to a few sites of the developing embryo, such as limbs, tongue, and the smooth muscle layers of the stomach and esophagus. Additional non-muscular sites of Col19a1 activity include the skin of the E16.5 embryos and the cerebral cortex and hippocampus of the new born brain. Unlike all other tissues, expression of Col19a1 in the central nervous system gradually increases after birth.

Comparison of relaxant effects of propofol on methacholine-induced bronchoconstriction in dogs with and without vagotomy

Propofol has been suggested to have in vivo airway relaxant effects, although the mechanism is still unclear. In this study, we determined whether propofol could antagonize methacholine-induced bronchoconstriction and determined whether vagotomy modifies this relaxant effect. Fourteen mongrel dogs anaesthetized with pentobarbital and pancuronium were assigned to a control group (n=7) and a vagotomy group (n=7). The trachea was intubated with a special endotracheal tube that had a second lumen for insertion of the bronchoscope. Bronchial cross-sectional area, which was monitored continuously through the bronchoscope, was measured with image analysis software. Bronchoconstriction was elicited with methacholine (0.5 microg kg(-1) + 5.0 microg kg(-1) min(-1)) until the end of the experiment. Thirty minutes after the start of methacholine infusion, propofol 0, 0.2, 2.0 and 20 mg kg(-1) was administered. Changes in bronchial cross-sectional area were expressed as percentages of the basal area. Plasma concentrations of propofol and catecholamine were measured by high-performance liquid chromatography. Maximal inhibition (bronchoconstriction = 0%, baseline = 100%) and IC50 (concentration producing 50% inhibition of maximal effect) produced by propofol was obtained from each concentration-response curve using a curve-fitting program. Methacholine decreased bronchial cross-sectional area to 49.3% (95% confidence interval 38.5-60.1%) and 45.3% (34.8-55.7%) of the baseline value. Propofol 20 mg kg(-1) significantly reversed this effect: bronchial cross-sectional area was reduced to 77.8% (66.2-89.6%) and 75.9% (64.0-87.9) in the control and vagotomy groups respectively. The two groups did not differ significantly in the maximal inhibitory effect of propofol [control group, 61.1% (46.3-75.9%), vagotomy group, 64.2% (40.1-88.3%)] or pIC50 [control group 5.03 (4.55-5.51), vagotomy group 4.86 (4.49-5.24)]. Therefore, the relaxant effects of propofol on methacholine-induced bronchoconstriction may not be mediated centrally. Propofol may relax airway smooth muscles directly or through the peripheral vagal pathway.

Recurrent hepatocellular carcinoma versus radiation-induced hepatic injury: differential diagnosis with MR imaging

The objective of this study was to assess the value of MR imaging in the differentiation between a recurrent hepatocellular carcinoma (HCC) and a radiation-induced hepatic injury. Nine male patients with suspected recurrence after radiotherapy for HCC underwent T(2)-, T(1)-weighted imaging and Gd-DTPA enhanced dynamic studies. T(2) relaxation times, signal intensity ratios in T(1)-weighted images (WI) and the relative enhancement of the dynamic study were calculated. Recurrent tumors and the irradiated area showed similar image characteristics: hypointense in T(1)-WI and hyperintense in T(2)-WI. T(2) values and signal intensity ratios in the T(1)-WI were not significantly different. In the gadolinium-enhanced dynamic study, a recurrent HCC showed early enhancement, followed by a rapid washout. However, the irradiated liver parenchyma showed hyperintensity from an early phase, and contrast enhancement tended to be more prominent and prolonged at the end of the dynamic studies. The characteristic findings of the dynamic MR study enable us to distinguish between a recurrent HCC and a radiation-induced hepatic injury.

Arterioportal shunts in cirrhotic patients: evaluation of the difference between tumorous and nontumorous arterioportal shunts on MR imaging with superparamagnetic iron oxide

OBJECTIVE

The study objective was to distinguish between the features of tumorous and nontumorous arterioportal shunts on superparamagnetic iron oxide-enhanced MR imaging in patients with cirrhosis.

SUBJECTS AND METHODS

Ten arterioportal shunts in eight patients, including four tumorous and six nontumorous arterioportal shunts, were evaluated on T2-weighted turbo spin-echo and T2(*)-weighted gradient-echo sequences before and after administration of superparamagnetic iron oxide. Qualitatively, the relative signal intensity of the arterioportal shunt compared with that of the surrounding liver parenchyma was categorized into three grades: high, slightly high, and not detected. Quantitatively, signal-to-noise ratio, contrast-to-noise ratio, lesion-to-liver contrast, and percentage enhancement were calculated and compared between tumorous and nontumorous arterioportal shunts by a nonparametric statistical test (Mann-Whitney test).

RESULTS

Qualitatively, all four tumorous arterioportal shunts appeared as areas of slightly high or high intensity without and with superparamagnetic iron oxide on T2-weighted turbo spin-echo images and changed from isointensity to high intensity after the administration of superparamagnetic iron oxide on T2(*)-weighted gradient-echo images. All nontumorous arterioportal shunts except one could not be recognized without or with superparamagnetic iron oxide on either sequence. Quantitatively, with superparamagnetic iron oxide the contrast-to-noise ratio and the lesion-to-liver contrast of the tumorous arterioportal shunts were significantly higher than those of the nontumorous arterioportal shunts.

CONCLUSION

Tumorous arterioportal shunts are seen as areas of reduced signal loss, whereas most nontumorous arterioportal shunts are seen as areas of normal signal loss, like the normal liver parenchyma. The difference is more marked on T2(*)-weighted gradient-echo images than on T2-weighted turbo spin-echo images.