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.

A comparison of the spasmolytic effects of olprinone and aminophylline on serotonin-induced pulmonary hypertension and bronchoconstriction with or without beta-blockade in dogs

In the present study in dogs, we compared with aminophylline the spasmolytic effects of olprinone, a novel phosphodiesterase 3 inhibitor, on serotonin-induced pulmonary hypertension (PH) and bronchoconstriction. Mongrel dogs were anesthetized with pentobarbital. PH and bronchoconstriction were induced with serotonin: 10 microg/kg + 1 mg x kg(-1) x h(-1), and assessed as % changes in pulmonary vascular resistance and bronchial cross-sectional area (basal = 100%). Initially, the relaxant effects of olprinone (n = 8: 0-1000 microg/kg) and aminophylline (n = 8: 0-100 mg/kg) were compared. Pulmonary vascular resistance and bronchial cross-sectional area were assessed before and 30 min after serotonin 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, n = 6) or aminophylline (100 mg/kg, n = 6) compared with saline (n = 6 each). Olprinone and aminophylline dose-dependently attenuated both PH and bronchoconstriction (olprinone > aminophylline: -logED(50)[mean] for PH and bronchoconstriction 5.37+/- 0.35[4.24 microg/kg] vs. 1.60+/-0.23[25.4 mg/kg] and 4.06+/-0.12[87.8 microg/kg] vs. 1.51+/-0.21[30.6 mg/kg], respectively). In addition, olprinone produced more potent pulmonary vasodilation than bronchodilation while aminophylline was equipotent. In addition, there was a significant increase in plasma catecholamines after olprinone (> or =100 microg/kg) and aminophylline (> or =10 mg/kg). With the exception of aminophylline-induced bronchodilation, propranolol did not reverse any of the other effects measured. Therefore, the spasmolytic effects of olprinone are independent of plasma catecholamines, while the bronchodilating effect of aminophylline may partially involve increased levels of circulating catecholamines.

[Magnetic resonance tomography (MRI) of joint cartilage. Current status of knowledge and new developments]

MRI is the most accurate noninvasive technique available for assessment of normal articular cartilage and cartilage lesions. MRI cannot only provide morphologic information about the area of damage, but can also provide unique insight into the biochemical composition of the articular cartilage. New image processing techniques such as three-dimensional mapping of cartilage thickness will help to establish automated analysis of cartilage loss. Theses techniques are ideally suited for monitoring patients who undergo treatment with new chondroregenerative drugs.

Multiple inflammatory pseudotumors mimicking liver metastasis from colon cancer: report of a case

A 54-year-old man underwent an operation for colon cancer histologically diagnosed as moderately differentiated adenocarcinoma with clinical staging of Dukes C. He was prescribed carmofur for adjuvant chemotherapy. A follow-up computed tomography scan done 6 months later revealed two new low-density areas in the liver. A diagnosis of metastatic adenocarcinoma from the previous colon cancer was presumed, based on the patient's history and radiological findings, and resection of the affected area of liver was performed. Histological examination of these tumors revealed that they were inflammatory pseudotumors (IPT). The patient had an excellent postoperative course and has shown no further signs of recurrence in the 3 years since his last operation. IPT of the liver is a rare disease, for which no methods of diagnosis and treatment have been established, since it is difficult to distinguish IPT from hepatocellular carcinoma or metastatic carcinoma. We describe this case with a review of the 101 cases of IPT documented in the Japanese literature, in the hope that it will contribute to the diagnosis and treatment of this unusual disease entity.

Correlation of diversity of leg morphology in Gryllus bimaculatus (cricket) with divergence in dpp expression pattern during leg development

Insects can be grouped into mainly two categories, holometabolous and hemimetabolous, according to the extent of their morphological change during metamorphosis. The three thoracic legs, for example, are known to develop through two overtly different pathways: holometabolous insects make legs through their imaginal discs, while hemimetabolous legs develop from their leg buds. Thus, how the molecular mechanisms of leg development differ from each other is an intriguing question. In the holometabolous long-germ insect, these mechanisms have been extensively studied using Drosophila melanogaster. However, little is known about the mechanism in the hemimetabolous insect. Thus, we studied leg development of the hemimetabolous short-germ insect, Gryllus bimaculatus (cricket), focusing on expression patterns of the three key signaling molecules, hedgehog (hh), wingless (wg) and decapentaplegic (dpp), which are essential during leg development in Drosophila. In Gryllus embryos, expression of hh is restricted in the posterior half of each leg bud, while dpp and wg are expressed in the dorsal and ventral sides of its anteroposterior (A/P) boundary, respectively. Their expression patterns are essentially comparable with those of the three genes in Drosophila leg imaginal discs, suggesting the existence of the common mechanism for leg pattern formation. However, we found that expression pattern of dpp was significantly divergent among Gryllus, Schistocerca (grasshopper) and Drosophila embryos, while expression patterns of hh and wg are conserved. Furthermore, the divergence was found between the pro/mesothoracic and metathoracic Gryllus leg buds. These observations imply that the divergence in the dpp expression pattern may correlate with diversity of leg morphology.

The brain link protein-1 (BRAL1): cDNA cloning, genomic structure, and characterization as a novel link protein expressed in adult brain

We report here molecular cloning and expression analysis of the gene for a novel human brain link protein-1 (BRAL1) which is predominantly expressed in brain. The predicted open reading frame of human brain link protein-1 encoded a polypeptide of 340 amino acids containing three protein modules, the immunoglobulin-like fold and proteoglycan tandem repeat 1 and 2 domains, with an estimated mass of 38 kDa. The brain link protein-1 mRNA was exclusively present in brain. When analyzed during mouse development, it was detected solely in the adult brain. Concomitant expression pattern of mRNAs for brain link protein-1 and various lectican proteoglycans in brain suggests a possibility that brain link protein-1 functions to stabilize the binding between hyaluronan and brevican. The human BRAL1 gene contained 7 exons and spanned approximately 6 kb. The entire immunoglobulin-like fold was encoded by a single exon and the proteoglycan tandem repeat 1 and 2 domains were encoded by a single and two exons, respectively. The deduced amino acid sequence of human brain link protein-1 exhibited 45% identity with human cartilage link protein-1 (CRTL1), previously reported as link protein to stabilize aggregates of aggrecan and hyaluronan in cartilage. These results suggest that brain link protein-1 may have distinct function from cartilage link protein-1 and play specific roles, especially in the adult brain.

Recurrence of meningiomas

BACKGROUND

Macroscopic total resection with removal of involved dura and bone does not always prevent the recurrence of meningioma of histologically benign subtype. Many causative factors have been investigated, although the mechanism of recurrence remains unclear. Vascular endothelial growth factor (VEGF) is a key factor in meningiomas neovascularization, and the authors investigated whether VEGF expression can predict the recurrence of histologically benign meningiomas after macroscopic total resection.

METHODS

Fifty-four patients with supratentorial convexity meningiomas were investigated at least 3 years after surgery or until tumor recurrence to clarify risk factors for recurrence. Patients were restricted to Simpson Grade 1 resection only, and the authors excluded multiple meningiomas, neurofibromatosis, and atypical and anaplastic meningiomas. Correlation between recurrence and the following factors were statistically analyzed: age, gender, tumor volume, tumor shape, bone change, brain edema, vascular supply, histologic subtype, MIB-1 labeling index (LI), and VEGF expression.

RESULTS

Of the 54 patients with meningioma, 34 were positive (24: +1; 10: +2) for VEGF, and 20 were negative. Six (11.1%) meningiomas recurred during the follow-up period. Multivariate analysis revealed that high levels of expression of VEGF constituted the most useful predictor of recurrence (P = 0.005), followed by high MIB-1 LI (P = 0.039). The other factors were not significant. The tumor recurrence, when it occurred, was within the brain and not durally based.

CONCLUSIONS

The current results suggest that high levels of VEGF expression are significantly related to the recurrence of meningioma. VEGF secretion from microscopic residue remaining after surgery may induce neovascularization, which promotes the recurrence of meningioma.

Differential expression of mouse alpha5(IV) and alpha6(IV) collagen genes in epithelial basement membranes

We first completed the primary structure of the mouse alpha5(IV) and alpha6(IV) chains, from which synthetic peptides were produced and a chain-specific monoclonal antibodies were raised. Expression of collagen IV genes in various basement membranes underlying specific organ epithelia was analyzed by immunohistochemical staining using these monoclonal antibodies and other antibodies from human and bovine sequences. It was possible to predict the presence of the three collagen IV molecules: [alpha1(IV)](2) alpha2(IV), alpha3(IV)alpha4(IV)alpha5(IV), and [alpha5(IV)](2)alpha6(IV). In skin basement membrane two of the three forms, [alpha1(IV)](2)alpha2(IV) and [alpha5(IV)](2)alpha6(IV), were detected. The alpha3(IV)alpha4(IV)alpha5(IV) molecule was observed as the major form in glomerulus, alveolus, and choroid plexus, where basement membranes function as filtering units. The molecular form [alpha5(IV)](2)alpha6(IV) was present in basement membranes in tubular organs such as the epididymis, where the tubes need to expand in diameter. Thus, the distribution of the basement membranes with different molecular composition is consistent with tissue-specific function.

Spasmolytic effects of prostaglandin E1 on serotonin-induced bronchoconstriction and pulmonary hypertension in dogs

In this study, we simultaneously evaluated the spasmolytic effects of prostaglandin E1 (PGE1) on serotonin-induced bronchoconstriction and pulmonary hypertension. Eleven mongrel dogs (8-12 kg) anaesthetized with pentobarbital were assigned to two groups: saline (n = 4) and PGE1 (n = 7). Bronchoconstriction and pulmonary hypertension were elicited with serotonin 10 micrograms kg-1 + 1 mg kg-1 h-1 and assessed as the percentage change in bronchial cross-sectional area (BCA) measured by bronchoscopy and pulmonary vascular resistance (PVR), respectively. Thirty minutes after starting the serotonin infusion, saline or PGE1 0 (saline), 0.01, 0.1, 1.0 or 10 micrograms kg-1 i.v. was given. %BCA and %PVR (basal = 100%) were assessed before and 30 min after serotonin, and 30 and 60 min after saline (saline group) or 5 min after each dose of PGE1 (PGE1 group). In the saline group, pulmonary hypertension and bronchoconstriction were stable. In the PGE1 group, PGE1 at > or = 0.1 microgram kg-1 significantly decreased %BCA and 10 micrograms kg-1 almost fully reversed the constriction (from mean (SEM) 56.2% (4.9%) to 94.4% (3.7%)). %PVR was significantly decreased at 10 micrograms kg-1 (from 230% (24%) to 176% (11%)) only. We suggest that PGE1 may produce bronchodilation rather than pulmonary vasodilation.

Changes in the liver parenchyma after proton beam radiotherapy: evaluation with MR imaging

The objective of this study was to describe magnetic resonance (MR) findings with a 1.5T imager for hepatic parenchymal changes after proton beam radiotherapy. Thirty-two patients who received proton radiotherapy with doses of 50-87 Gy underwent MR imaging 1-75 months (mean 22 months) after the start of irradiation. Axial T(2), T(1)-weighted imaging, and a dynamic study after a gadolinium injection were performed. The irradiated areas showed hypointense in T(1)-weighted images, hyperintense in T(2)-weighted images, and intense and prolonged enhancement on the dynamic study (maximum relative enhancement 441.8%+/-263.3 vs. surrounding liver 145.6%+/-67.7, p<0.0001). T(2) values of the irradiated areas were 50.6 to 65.8 msec greater than in the surrounding liver (p<0.005). The values increased with time, being significantly greater 13 months or longer after the beginning of the therapy than after a period of less than 3 months (p<0.05). Pathologic examinations (n = 3) indicated that the irradiated areas were composed of collapsed lobules with hepatic small vein occlusions, and rich extracellular matrices which retained extracellular fluid. MR imaging can demonstrate hepatic parenchymal changes after proton beam radiotherapy, and show the changes are irreversible.

Early radiation effects on the liver demonstrated on superparamegnetic iron oxide-enhanced T1-weighted MRI

Early radiation-induced liver injury during radiotherapy detected by a particulate reticuloendothelial MR contrast agent (superparamagnetic iron oxide; SPIO) is described in a patient with cholangiocarcinoma. The irradiated hepatic parenchyma appeared as a heterogeneous, less decreased signal intensity area than the nonirradiated area on MR images after SPIO administration. Resultant differences in signal intensity were better visualized on SPIO-enhanced T1-weighted images than SPIO-enhanced T2-weighted images, although SPIO-enhanced T2*-weighted fast field echo imaging was the most sensitive.

[A multicenter study of cardiac events and anesthetic management of patients with ischemic heart diseases for noncardiac surgery--a follow-up report]

We have conducted a joint research project to investigate the incidence of ischemic heart disease in patients for noncardiac surgery and to define the risk of perioperative cardiac complications in these patients. From September to November 1997 we had 7288 patients scheduled to undergo noncardiac surgery in the 8 departments of anesthesiology. Of these patients, 228 (3.1%) patients had ischemic heart disease, and 30 of them (13.2%) developed perioperative cardiac events. Critical cardiac events, including perioperative myocardial ischemia and lethal arrhythmia, occurred in 7 of these patients. In our region of Japan, 3-4% of surgical patients tend to develop ischemic heart disease and 3.1% of them demonstrated severe cardiac complications perioperatively. Compared with United States we encounter fewer surgical patients with ischemic heart disease, but the risk of developing perioperative cardiac complications in such patients is almost the same for both countries.

[An successful case of combined daily oral administration of UFT and low-dose etoposide for multiple metastases of lung cancer]

The authors treated a 49-year old female patient, who had multiple metastases of lung cancer, by combined daily oral administration of UFT and low-dose ETP. She was admitted to our hospital due to complaints of cough and dyspnea, and multiple nodular shadows were seen in both lungs on chest X-rays. The pulmonary lesion was diagnosed as pulmonary metastasis of lung cancer (squamous cell car) by lung biopsy under CT-guide. She also had bone metastasis of the ribs and cerebellar metastasis from the lung cancer. Combination chemotherapy of UFT 300 mg/body daily and etoposide 25 mg/body daily was performed for 13 months. The pulmonary metastatic tumors were reduced significantly. No side effects of the carcinostatic agents were noted. She is now doing well. Combined daily oral administration of UFT and low-dose etoposide is considered to be safe and effective, and the treatment useful for recovering QOL in advanced lung cancer patients.

Transcatheter embolization of mycotic aneurysm of the subclavian artery with metallic coils

Mycotic aneurysms of the subclavian artery are rare. This report describes an experience of 2 rare cases in which transcatheter embolization with metallic coils was performed for the management of these lesions alternative to surgery. Two patients who had been treated with chemotherapy for malignant neoplasms were diagnosed as having mycotic aneurysms of the left subclavian artery. The causes of these lesions were presumed to be the invasion of the arterial wall by the pulmonary abscess in case 1, and wound infection after placement of the reservoir for intraarterial chemotherapy in case 2. In both cases, proximal and distal sites of the aneurysm were embolized with metallic coils. In case 1, the vertebral artery was also embolized with Guglielmi detachable coils to avoid retrograde blood flow. Both aneurysms were completely occluded by a single embolization. In case 1, although weakness and paresthesia of the left hand remained, lethal hemoptysis due to aneurysmal fistulization to the lung parenchyma ceased. In case 2, no neurological deficit except for mild paresthesia in the left thumb had been observed. Both patients died of primary disease 10 and 5 months after the procedure. Transcatheter embolization is technically feasible and effective enough to treat the mycotic aneurysm of the subclavian artery even in the situation in which the surgical option seems to be difficult or risky.

Heat shock protein 72 expression in the right ventricle of patients undergoing congenital cardiac surgery

While heat shock protein (HSP) 72 is known as a stress protein, there have been no reports of HSP 72 expression in patients who have undergone surgery for congenital heart disease. Fourteen patients (7 males and 7 females) who had undergone surgery for congenital heart disease were studied. The ages of the patients ranged from 2 months to 43 years old (mean 6.5 +/- 10.8 years old; median 3.0 years old). The diagnoses were Tetralogy of Fallot in seven, pulmonary atresia with ventricular septal defect (VSD) in three, complex anomalies in three, and VSD in one patient. Histological study and HSP analysis using Western blots and immunostaining with anti-HSP 72 monoclonal antibody were performed for right ventricular muscle samples resected during the surgery. The histological findings showed hypertrophic changes of ventricular cardiomyocytes in all samples studied. Western blots detected HSP 72 expression of various degrees in all specimens. Immunostaining using monoclonal antibody against HSP 72 showed that the protein was present in the nuclei and cytoplasm of cardiomyocytes. In conclusion, although it is difficult to determine the cause of the "stress" that triggers HSP 72 expression in cardiomyocytes, low O2 saturation and pressure overload might act as a "stress", and the only common factor that induced HSP 72 in every sample was hypertrophy.

[Multicenter study of cardiac events and anesthetic management of patients with ischemic heart diseases undergoing noncardiac surgery]

We designed a joint research project to investigate the incidence of ischemic heart diseases in patients undergoing noncardiac surgery and to define the risk of perioperative cardiac complications in these patients. Of the 8358 surgical patients in the 8 departments of anesthesiology between March 1997 and June 1997, 328 (3.9%) had ischemic heart diseases. Among the 328 patients, 54 (16.4%) developed perioperative cardiac events, including myocardial infarction (3 patients) and either lethal or potentially dangerous dysrhythmias (51 patients). Preoperative cardiac assessments were performed while the anesthetic techniques including intensive monitoring and perioperative prophylactic therapy were also employed. Patients with ischemic heart diseases received various types of preoperative evaluation to identify the degree of coronary artery disease and to assess the overall cardiac function. The patients were monitored using a multilead electrocardiogram, an arterial line, a central venous catheter, a pulmonary artery catheter, and by transesophageal echocardiography intraoperatively. Therapeutically, isosorbide, nitroglycerin, beta-blockers, calcium channel blockers, and/or nicorandil were administered to prevent perioperative ischemia. So far, no generally accepted management strategies have been established in patients with cardiovascular disorders based on large-scale outcome trials in Japan. Therefore, nationwide large multicenter trials are awaited with interest in order to establish helpful guidelines to improve the perioperative management and to reduce ischemia in cardiac patients undergoing noncardiac surgery.

Absence of mutations in the NBS1 gene in B-cell malignant lymphoma patients

BACKGROUND

Nijmegen breakage syndrome (NBS), also known as ataxia-telangiectasia (AT) variant, is an autosomal recessive disorder characterized by microcephaly, growth retardation, severe combined immunodeficiency and a high incidence of lymphoid carcinoma, the majority of which are B-cell lymphomas. To determine whether the NBS1 gene is a tumor suppressor gene in B-cell lymphoma, we screened B-cell malignant lymphoma (ML) for any evidence of NBS1 mutation.

MATERIALS AND METHODS

Sequence analysis of the NBS1 gene was performed from PCR products amplified from the DNA of 12 extracranial ML or RT-PCR products amplified from cDNA of 8 primary central nervous system lymphoma.

RESULTS

Direct sequence analysis revealed that no NBS1 mutations were present in any of these patients.

CONCLUSION

The present results suggested that the contribution of NBS1 mutations to B-cell ML was minimal, despite the fact that the NBS1 gene was causative factor in these cases.

Subtraction CT with low-flow-rate arterial contrast injection to estimate drug distribution during balloon-occluded arterial chemotherapy infusion for bladder cancer

PURPOSE

To simulate drug distribution during balloon-occluded arterial chemotherapy infusion (BOAI) for urinary bladder cancer using subtraction computed tomography (CT) with low-flow-rate arterial contrast injection (S-CTLA).

METHODS

Ten patients with bladder cancer underwent S-CTLA, and the distribution of contrast agent during BOAI into both internal iliac arteries simultaneously was evaluated in nine pairs of internal iliac arteries and one single artery. For S-CTLA, spiral CT data were acquired before and after 0.2 ml/sec intraarterial injection of contrast material. The enhancement of the urinary bladder wall, the gluteal muscles, and the pelvic bones was categorized using a 4-grade scale. The grades were compared in each of the three pelvic components and differences were tested for significance using the Wilcoxon test for paired groups.

RESULTS

S-CTLA revealed the distribution of the contrast agent clearly. Gluteal muscles grades were significantly higher than those of the other two assessed components.

CONCLUSION

BOAI does not improve the concentration of contrast agent to the bladder wall over neighboring structures, suggesting that the balloon occlusion technique does not achieve its desired goal for chemotherapy targeting.

[Changes in MR imaging appearance of breast cancer after intra-arterial infusion chemotherapy]

The purpose of this study was to evaluate whether the characteristic change in breast cancer related to chemotherapeutic response (CR) and the effect of invasion and toxicity in the skin and pectoralis muscle exist on MR imaging after intra-arterial infusion chemotherapy. A total of 11 patients with histologically proven breast cancer underwent MR study before and after chemotherapy. Changes in images and the dynamic curve-after-chemotherapy were evaluated, including time to maximum signal intensity (SI) and the early phase enhance ratio (EPER) in the tumor. In the tumor, changes in the dynamic curve, time to maximum SI, EPER and necrosis did not correlate with CR, but change in SI on T2-weighted images was suggested to do so. Changes in the dynamic curve and images in the pectoralis muscle and in images on the skin were suggested to correlate with CR. In addition, images changed for the worse in many cases of invasion and toxicity in the pectoralis muscle and in some cases of invasion in the skin. In conclusion, tumors had fewer imaging changes correlating with CR after intra-arterial infusion chemotherapy. Changes for the worse in images of the pectoralis muscle and skin may be useful for the evaluation of invasion.

Milrinone attenuates serotonin-induced pulmonary hypertension and bronchoconstriction in dogs

We determined whether milrinone, a phosphodiesterase III inhibitor, attenuates serotonin-induced (5-hydroxytryptamine [5HT]) pulmonary hypertension (PH) and bronchoconstriction. Dogs were anesthetized with pentobarbital (30 mg/kg + 2 mg. kg(-1). h(-1)). Bronchoconstriction and PH were elicited by 5HT (10 microg/kg + 1.0 mg. kg(-1). h(-1)). Pulmonary vascular resistance was used to assess PH. Bronchoconstriction was also assessed by changes in bronchial cross-sectional area obtained from our bronchoscopic method. At 30 min after 5HT infusion started, seven dogs were given milrinone: 0 (saline), 5, 50, 500, and 5000 microg/kg at 10-min intervals. The other 12 dogs were given milrinone 5000 microg/kg 30 min after 5HT infusion, and 5 min later were given propranolol 0.2 mg/kg (n = 6) or saline (n = 6) IV. The 5HT significantly increased percentage of pulmonary vascular resistance to 208% +/- 27% and decreased percentage of bronchial cross-sectional area to 52% +/- 5% of the basal. Milrinone significantly attenuated both PH and bronchoconstriction in a dose-dependent manner. However, -log 50% effective concentration (mean ED(50) in microg/kg) of milrinone for bronchoconstriction: 4.32 +/- 0.13 (47.6) was significantly smaller than that for PH: 3.84 +/- 0.29 (144.9) (P < 0.01). In addition, the spasmolytic effects of milrinone (5000 microg/kg) were not antagonized by propranolol, although this dose significantly increased plasma catecholamines. In conclusion, milrinone attenuates 5HT-induced PH and bronchoconstriction; however, this drug may be more sensitive to phosphodiesterase III in the airway smooth muscle than in pulmonary vascular smooth muscle. In addition, the relaxant effects could not be caused by beta-adrenoceptor activation because beta-blocker did not antagonize.

IMPLICATIONS

We studied the effects of milrinone on serotonin-induced pulmonary hypertension and bronchoconstriction in dogs. Milrinone produces pulmonary vasodilation and bronchodilation, whose effects may not be caused by beta-adrenoceptor activation. In addition, this drug may be more sensitive to phosphodiesterase III in the airway smooth muscle than that in pulmonary vascular smooth muscle.

Differential expression of human spasmolytic polypeptide (trefoil factor family-2) in pancreatic carcinomas, ampullary carcinomas, and mucin-producing tumors of the pancreas

Human spasmolytic polypeptide (hSP) is a member of the trefoil peptide group, thought to be involved in mucin production and cell growth. It has been reported that hSP protein is expressed in digestive cancers but not in normal pancreas. The expression of hSP in pancreatic neoplasms has not been investigated in detail. The immunohistochemical expression of hSP protein was investigated in pancreatic carcinomas, ampullary carcinomas, mucin-producing tumors, serous cystadenomas and islet cell tumors of the pancreas. hSP was expressed in 23% of pancreatic duct cell carcinomas, and hSP protein was more frequently detected in cases of early-stage or histologically low-grade duct cell carcinomas than in cases of late-stage or histologically high-grade carcinomas. Patients with hSP protein expression showed a better prognosis than did those with negative hSP expression. hSP expression was detected in 92% of mucin-producing tumors, but was not detected in serous cystadenoma or islet cell tumors. Immunohistochemical hSP expression is related to differentiation and a better prognosis in pancreatic duct cell carcinomas. Furthermore, hSP protein is related to the pathogenesis and clinical characteristics of mucin-producing tumors of the pancreas.

Doxapram accentuates white matter injury in neonatal rats following bilateral carotid artery occlusion

The effect of the respiratory stimulant, doxapram, on white matter damage was investigated in neonatal rats under cerebral ischemia. Five-day-old rats underwent bilateral carotid artery occlusion with or without 50 mg/kg i.p. of doxapram. Their brains were neuropathologically examined 48 h later. Doxapram induced about a 20% decrease of PCO(2) for 90 min, but did not cause any neuropathological abnormalities. Bilateral carotid artery occlusion resulted in mild cerebrocortical lesions in 67% of pups, and white matter lesions in the internal capsule in 44%. Doxapram, in addition to bilateral carotid artery occlusion, produced more severe white matter injury in the internal capsule (injury score; 0.67+/-0.87 vs. 1.70+/-0.48, P<0.05) and in the subcortical white matter (0.33+/-0. 67 vs. 1.10+/-0.54, P<0.05). These results demonstrated that the use of doxapram under an ischemic condition accentuates white matter damage in neonatal rats.

Effects of lithium on the pharmacokinetics of valproate in rats

Combined treatment with lithium and valproate has been used for bipolar disorder. However, the studied interaction between these two drugs has not been fully investigated. We therefore examined the effects of lithium on the pharmacokinetics (plasma disappearance, metabolism and urinary excretion) of valproate in rats. Lithium (2 mEq kg(-1)) was administered intraperitoneally twice a day for ten days. Plasma disappearance curves of valproate (50 mg kg(-1), i.v.), valproate-metabolizing activities of UDP-glucuronosyltransferase (UGT) and cytochrome P450 (CYP) in liver microsomes and urinary excretion of free valproate and valproate-glucuronide were examined. The metabolizing activity of UGT and CYP were determined by enzyme assays and a fluorescence polarization immunoassay system. Urinary valproate-glucuronide was obtained using this system by subtracting the free level from total level, which was determined after deconjugating the sample with heat and NaOH. The half-life of plasma disappearance of valproate was 25% reduced by lithium pretreatment (0.428 +/- 0.031 h with repeated lithium pretreatment vs 0.578 +/- 0.062 h for controls). The valproate-metabolizing activity of UGT and CYP were not altered by lithium although lithium increased the urinary excretion of valproate-glucuronide. In conclusion, lithium pretreatment causes a decrease in plasma valproate levels and an increase in urinary excretion of valproate-glucuronide in rats.

Peliosis hepatis and neoplastic/dysplastic lesions in aged male Long-Evans Cinnamon rats: MR imaging with pathologic correlation

The Long-Evans Cinnamon (LEC) rat, an animal model of Wilson's disease, abnormally accumulates copper in the liver. There have been a lot of reports on preneoplastic and neoplastic hepatic tumors in LEC rats, but few studies have been focused on other lesions. The aim of this study was to describe the MR findings of the liver of LEC rats with pathologic correlation to characterize the hepatic lesions developed in them. We measured MR images of the liver of six aged (over the age of 70 weeks old) male LEC rats. Measurements of T(1), T(2)-weighted images, and the dynamic and delayed studies after i.v. gadolinium injection were performed. The rats were sacrificed immediately after the measurements, and the diagnosis was histologically made. We identified seven lesions of peliosis hepatis, three neoplastic/dysplastic lesions, three cysts and one cholangiofibrosis. Peliosis hepatis was characterized as showing a significantly long T(2) relaxation time of 57.9 +/- 13.3 ms (mean +/- standard deviation) compared with 41.3 +/- 1.7 ms in normal liver, and prolonged enhancement after a gadolinium injection. Neoplastic/dysplastic lesions tended to show prolonged T(2), and they showed isointensity on T(1)-weighted images. They were best characterized by early enhancement followed by a rapid wash-out after a gadolinium injection. In conclusions, the frequent occurrence of peliosis hepatis observed in the present study suggests this can be a characteristic lesion in aged LEC rats. The characteristic MR findings enable us to distinguish between peliosis hepatis and neoplastic/dysplastic lesions.

MR imaging of radiation osteitis in the sacroiliac joints

The purpose of this study was to analyze magnetic resonance (MR) images of radiation osteitis of sacroiliac joints, retrospectively. Seven patients with radiation osteitis, which was diagnosed by pelvic plain radiographs and CT images, underwent MRI. T(1)-weighted spin echo images and T(2)-weighted fast spin echo images were obtained in all patients. Four patients were examined after gadolinium injection. Major signal changes of radiation osteitis were distributed on the iliac side. T(1)-weighted images showed diffuse low intensity both in sacral and iliac sides. T(2)-weighted images showed very low intensity adjacent to sacroiliac joints, but mixed intensity was illustrated apart from joints, and high intensity in the peripheral areas. Radiation osteitis showed slight to mild, but irregular enhancement in four patients after gadolinium administration. MRI can illustrate abnormal bone change distribution and is useful for diagnosing this entity by characteristic intensity patterns on T(1)-weighted images with and without gadolinium and T(2)-weighted image. However, the diagnosis of accompanied insufficiency fractures in the area of radiation osteitis is occasionally difficult with conventional MRI.

Chronic hydrocephalus in elderly patients following subarachnoid hemorrhage

BACKGROUND

With the aging of the population, surgery for ruptured intracranial aneurysms is increasing among the elderly. We sought to clarify the characteristics of chronic hydrocephalus following aneurysmal subarachnoid hemorrhage (SAH) in elderly patients.

METHODS

Of the 576 surgically treated patients, 289 were aged 59 years or younger, 169 were 60 to 69, and 118 were 70 years or older. The relationship between chronic hydrocephalus and the causative factors was analyzed for each age group.

RESULTS

Of the 576 patients, chronic hydrocephalus was observed in 215 (37%), with the incidence increasing significantly with age (p < 0.001) and being the highest in the oldest age group. In elderly patients, the incidence of chronic hydrocephalus was relatively high, even after mild SAH. The incidence of chronic hydrocephalus was high regardless of age in patients with severe SAH, such as in those with H&H grades III-IV, SAH grades III-IV, acute hydrocephalus, symptomatic vasospasm, and intraventricular hemorrhage, and in those with vertebro-basilar artery aneurysms.

CONCLUSION

In the elderly, the incidence of chronic hydrocephalus following SAH was significantly higher than in younger patients, even after mild SAH. In elderly patients, careful observation and individualized treatment are necessary even if SAH is mild.

A pulse-based, parallel-element macromodel for ferroelectric capacitors

A pulse-based behavioral model is proposed and implemented in HSPICE. Hysteresis-loop and pulse measurement results are used to extract the model parameters. The model accurately predicts the bitline voltage of a ferroelectric memory testchip.

Asymmetric expression of antivin/lefty1 in the early chick embryo

Mammalian lefty and zebrafish antivin, highly related to lefty, are shown to be expressed asymmetrically and involved in the specification of the left body side of early embryos. We isolated a chick homologue of the antivin/lefty1 cDNA and studied its expression pattern during early chick development. We found that antivin/lefty1 is expressed asymmetrically on the left side of the prospective floorplate, notochord and lateral plate mesoderm of the chick embryo.

High-resolution MR imaging of the knee at 3 T

PURPOSE

To examine the practical feasibility of using a 3.0-T MR unit to obtain high-quality, high-resolution images of the knee joint.

MATERIAL AND METHODS

One human cadaveric and 5 porcine knees were imaged with the 3.0-T unit. Sets of T1-weighted spin echo images were obtained with in-plane resolution of 0.195x0.39 mm and an acquisition time of approximately 5 min. Two porcine knees were also imaged with the 1.0-T unit with an identical imaging protocol and the signal-to-noise (S/N) ratios were measured on images at 3 T and 1 T.

RESULTS

The 3-T MR system provided detailed delineation of the knees. Deep layers of the medial collateral ligament and associated fine fibers beneath the medial and lateral collateral ligament were demarcated. We observed precise demonstration of the tibial attachment of the anterior cruciate ligament, irregularity of the meniscal free edge, and conjoint tendon formation together with the lateral collateral ligament and the biceps femoris tendon. Compared to the 1-T unit, the S/N ratio with the 3-T unit was increased by a factor of 1.39 to 1.72.

CONCLUSION

Due to the potential advantage of obtaining detailed images, the 3-T MR system suggests a practical utility for fine demonstration of the knee morphology.

Helical CT imaging of gastric cancer: normal wall appearance and the potential for staging

PURPOSE

To evaluate the CT appearance of the normal gastric wall and the effectiveness of contrast enhanced helical CT for T-staging of gastric cancer.

METHODS

For the basic experiment, two resected stomachs with gastric cancer were filled with water and examined by helical CT imaging. For the clinical study, 59 consecutive patients with gastric cancer who had received preoperative helical CT examination and had also been operated on were entered in this study. Helical CT images were evaluated independently by three radiologists without knowledge of histological staging results.

RESULTS

The basic examination of a histopathological correlation with CT images revealed that the inner layer with high attenuation corresponded to the mucosa and the muscular layer of the mucosa, the middle layer with low attenuation to the submucosal layer consisting of coarse tissues and containing fatty tissues, and the outer layer with slightly high attenuation to the proper muscle with serosa. The clinical study revealed that the rate of correct diagnosis through consensus reading was 66.1%.

CONCLUSION

The entire stomach with a well-stained mucosa can be visualized by contrast enhanced helical CT. However, T-staging of gastric cancer by helical CT did not appear to improve the accuracy of staging.

Effects of ethanol on neuronal migration and neural cell adhesion molecules in the embryonic rat cerebral cortex: a tissue culture study

To investigate whether ethanol has direct effects on neuronal migration in the cerebral cortex, we performed a tissue culture study using embryonic rat brain with thymidine autoradiography. After we labeled progenitor cells in the ventricular zone of E16 cerebral cortex explants with [3H]thymidine, the explants were cultured for 48 h, and then distribution of labeled cells was evaluated autoradiographically. Adding 3.0 or 6.0 mg/ml ethanol to the culture medium caused significantly decreased distribution of labeled cells in the outer intermediate [control: 2.0+/-0.6% (mean+/-S.D.); 1.0 mg/ml ethanol: 2.1+/-1.5%; 3.0 mg/ml ethanol: 0. 5+/-1.5% (P<0.05); 6.0 mg/ml ethanol: 0.4+/-0.5% (P<0.05)] and the inner intermediate-A zones [control: 19.5+/-6.2%; 1.0 mg/ml ethanol: 13.1+/-8.6%; 3.0 mg/ml ethanol: 3.0+/-3.4% (P<0.01); 6.0 mg/ml ethanol: 5.2+/-2.9% (P<0.01)] compared to the control group. The mitotic index after 48-h culture was significantly reduced in the 6. 0 mg/ml ethanol group (0.260+/-0.114%; P<0.01) compared to the control group (0.600+/-0.158%). This suggests that ethanol inhibits neuronal migration in the cerebral cortex, although prolongation of the cell cycle by ethanol may contribute to the decreased number of labeled cells in the outer intermediate and inner intermediate-A zones. Furthermore, an abnormally dense and tortuous staining pattern of immunoreactive products of N-CAM was seen on the surface of migrating neurons in the 3.0 and 6.0 mg/ml ethanol groups, while the L1 staining pattern did not differ between the control and ethanol groups. These results suggest that abnormal expression of N-CAM may be involved in the inhibition of neuronal migration by ethanol.

Intramuscular metastasis from malignant melanoma: MR findings

We present a rare case of intramuscular metastasis from malignant melanoma. The lesion showed intermediate to high signal intensity on T1-weighted magnetic resonance (MR) images and mixed signal intensities containing high and low signals on T2-weighted images. The signal intensity on T1-weighted images, which is due to the paramagnetic effect of melanin, is a characteristic MR finding of this entity.

Immunohistochemical nitrotyrosine distribution in neonatal rat cerebrocortical slices during and after hypoxia

The peroxynitrite contributions to hypoxic damage in brain slices that arise from N-methyl-D-aspartate (NMDA) receptor activation were studied by following the temporal-spatial course of nitrotyrosine (NT) formation during six conditions: hypoxia (pO(2)<5 mmHg) with or without 10 microM MK-801 treatment; with exposure to 10, 100 and 1000 microM NMDA; and no treatment (control). In each experiment, twenty 350-micrometer thick cerebrocortical slices, obtained from the parietal lobes of ten 7-day-old Sprague-Dawley rats, were metabolically recovered and allowed to respire in a well-oxygenated perfusion system. Thirty minutes exposures to hypoxia or NMDA were followed by 2 h of oxygenated reperfusion. MK-801 administration began 15 min prior to hypoxia and was discontinued during reperfusion. Anti-NT serum immunohistochemistry stains in 20-micrometer frozen sections of slices taken during oxygenated reperfusion, after hypoxia or NMDA exposure, were positive in both neurons and endothelial cells. NT-positive neurons were detected sooner after hypoxia than after NMDA exposure, suggesting that mechanisms of superoxide generation were different in both groups. After hypoxia and even more so after NMDA exposure, more intense NT-positive staining was observed in endothelial cells than in neurons. Cell damage after hypoxia was attenuated by MK-801. MK-801 decreased post-hypoxia counts of NT-stained endothelial cells by 78.5% (p<0. 001) and NT-stained neurons by 54.1% (p<0.05). Our findings suggest that NMDA receptor activation in hypoxic brain slices is associated with increased post-hypoxic peroxynitrite production that contributes to acute neuronal death and endothelial cell injury. Peroxynitrite injury to endothelial cells, caused either by increased peroxynitrite from within or from increased vulnerability to peroxynitrite from without, might play an important role in hypoxic-ischemic brain injury and NMDA-induced brain injury.

[Measurement of left ventricular filling by automated contour tracking method in echocardiography: comparison with radionuclide ventriculography]

Recent development of an automated contour tracking (ACT) method using the energy minimization principle provides automated edge detection and tracking of the endocardial boundary of the left ventricle, without tracing a region of interest. This study determined whether left ventricular filling indexes obtained from the ACT method provide a reliable estimate of left ventricular diastolic filling. Fourteen patients were examined by the ACT method and equilibrium radionuclide ventriculography. The volume-time wave form for ACT measurements was obtained from the 4-chamber views. Peak filling rate and time to peak filling rate measured by the ACT method were compared with those determined by radionuclide ventriculography. Peak filling rate and time to peak filling rate by the ACT method were closely correlated with those determined by radionuclide ventriculography (peak filling rate: r = 0.88, y = 0.71x + 0.36, SEE = 0.54 ml/end-diastolic volume/sec, time to peak filling rate: r = 0.89, y = 0.72x + 30.0, SEE = 0.02 msec, respectively) The ACT method is useful for the assessment of left ventricular diastolic filling.