Airflow limitation in Japanese smokers: significance of serum neutrophil elastase/alpha(1)-proteinase inhibitor ratio and FEV(1) (%pred) adjusted by pack-years

BACKGROUND

In spite of the known role of cigarette smoking in the development of airflow limitation (AL), fewer than 20% of smokers actually develop chronic obstructive pulmonary disease (COPD).

OBJECTIVES

We examined how smoking histories and indices in blood are related to the degree of AL in asymptomatic smokers in order to determine whether they can predict the development of AL.

METHODS

Spirometry and peripheral blood tests were examined in 433 Japanese asymptomatic current smokers at the initial examination. Forced expiratory volume in 1 s (FEV(1)) was measured periodically for 2 or more years (2-13 years) in 66 of the subjects.

RESULTS

AL defined as an FEV(1)/vital capacity of less than 0.7, was found in 11.3% (49 of 433) of the smokers. Pack-years of smoking, serum amounts of alpha(1)-proteinase inhibitor, and serum procollagen III peptide activities were correlated with the degree of AL. Fifteen percent (10 of 66) of subjects underwent rapid declines in FEV(1) that were found to be related not with smoking amounts or initial FEV(1), but with low FEV(1) (%pred) adjusted by pack-years and an elevated serum neutrophil elastase/alpha(1)-proteinase inhibitor ratio. These results suggest that smokers with a low FEV(1) out of proportion to pack-years are susceptible smokers at a high risk of developing COPD, and further, that increased proteinase burden relative to antiproteinase activity may contribute to the development of COPD.

CONCLUSIONS

We conclude that the serum neutrophil elastase/alpha(1)-proteinase inhibitor ratio and FEV(1) (%pred) adjusted by pack-years can be reliable predictors of the development of COPD.

Profilin is required for sustaining efficient intra- and intercellular spreading of Shigella flexneri

The ability of Shigella to mediate actin-based motility within the host cell is a prominent pathogenic feature of bacillary dysentery. The ability is dependent on the interaction of VirG with neural Wiskott-Aldrich syndrome protein (N-WASP), which in turn mediates recruitment of Arp2/3 complex and several actin-related proteins. In the present study, we show that profilin I is essential to the rapid movement of Shigella in epithelial cells, for which the capacity of profilin to interact with G-actin and N-WASP is critical. In COS-7 cells overexpressing either mutated profilin H119E, which failed to bind G-actin, or H133S, which is unable to interact with poly-l-proline, Shigella motility was significantly inhibited. Similarly, depletion of profilin from Xenopus egg extracts resulted in a decrease in bacterial motility that was completely rescued by adding back profilin I but not H119E or H133S. In COS-7 cells overexpressing a N-WASP mutant lacking the proline-rich domain (Deltap) unable to interact with profilin, the actin tail formation of intracellular Shigella was inhibited. In N-WASP-depleted extracts, addition of Deltap but not full-length N-WASP was unable to restore the bacterial motility. Furthermore, in a plaque formation assay with Madin-Darby canine kidney cell monolayers infected by Shigella, Madin-Darby canine kidney cells stably expressing H119E, H133S, or Deltap reduced the bacterial cell-to-cell spreading. These results indicate that profilin I associated with N-WASP is an essential host factor for sustaining efficient intra- and intercellular spreading of Shigella.

Cataractogenesis in neonatal Sprague-Dawley rats by N-methyl-N-nitrosourea

Cataract was induced by a single intraperitoneal injection of 100 mg/kg N-methyl-N-nitrosourea (MNU) to 0-, 5-, 10-, 15-, or 20-day-old male and female Sprague-Dawley rats. In day 0, 5, 10, and 15 MNU-treated rats, mature cataracts were constantly seen 7, 14, 14, and 30 days after dosing, respectively. In the day 20 MNU-treated rats, only subcapsular cataract was seen 30 days after dosing. Therefore, the rats exposed to MNU at an earlier age caused cataract more rapidly and severely. In the day 0 MNU-treated rats, 7-methyldeoxyguanosine DNA adduct was detected in the lens epithelial nuclei 12 hours after MNU dosing, followed by apoptosis, which was confirmed by morphology, by TUNEL signals, and by DNA ladder and peaked 3 days after MNU dosing. In the apoptosis cascade, upregulation of Bax, downregulation of Bcl-2, and increased CPP32 protease (caspase-3) activity were seen 12 hours after MNU dosing. Therefore, the pathogenesis of MNU-induced cataract was associated with DNA adduct formation in the lens epithelial cell nuclei leading to apoptosis by upregulation of Bax protein, downmodulation of Bcl-2 protein, and activation of caspase-3.

Arp2/3 complex-independent actin regulatory function of WAVE

We report that WAVE1/Scar1, a WASP-family protein that functions downstream of Rac in membrane ruffling, can induce part of the reorganization of the actin cytoskeleton without Arp2/3 complex. WAVE1 has been reported to associate and activate Arp2/3 complex at its C-terminal region that is rich in acidic residues. The deletion of the acidic residues abolished the interaction with and the activation ability of Arp2/3 complex. The expression of the mutant WAVE1 lacking the acidic residues (DeltaA), however, induced actin-clustering in cells as the wild-type WAVE1 did. In addition, this actin-clustering could not be suppressed by the coexpression of the Arp2/3 complex-sequestering fragment (CA-region) derived from N-WASP, which clearly inhibits Rac-induced membrane ruffling. This study therefore demonstrates that WAVE1 reorganizes the actin cytoskeleton not only through Arp2/3 complex but also through another unidentified mechanism that may be important but has been neglected thus far.

The utility of diffusion-weighted imaging with navigator-echo technique for the diagnosis of spinal epidermoid cysts

We report a case of a spinal epidermoid cyst in which diffusion-weighted imaging with a navigator-echo technique was useful for the differential diagnosis from other cystic tumors. Motion artifacts are inherent on diffusion-weighted images of the spinal region; however, the navigator-echo technique compensated for this problem and provided high-quality images. Diffusion-weighted imaging with navigator echoes is considered to be a potentially useful tool in the differential diagnosis of spinal cystic tumors.

RT-PCR suggests human skeletal muscle origin of alveolar soft-part sarcoma

In 1952, Christopherson et al. proposed that alveolar soft-part sarcoma (ASPS) was a distinct entity with unique clinical and pathological features. Since their report, its histogenesis has not been determined. In order to clarify the histogenesis of ASPS, a study using reverse transcription polymerase chain reaction using cDNAs from MyoD1 and myogenin, and the actin filament from human-skeletal-muscle-related mRNAs has been performed in 5 cases of ASPS. The expression of MyoD1 and myogenin was determined in 5 and 2 cases of the 5 cases, respectively. Moreover, expression of the many mRNAs from the actin filament of skeletal muscle was also found in ASPS. According to these findings, it is now postulated that ASPS is of skeletal muscle origin.

Essential role of neural Wiskott-Aldrich syndrome protein in neurite extension in PC12 cells and rat hippocampal primary culture cells

Neural Wiskott-Aldrich syndrome protein (N-WASP) is an actin-regulating protein that induces filopodium formation downstream of Cdc42. It has been shown that filopodia actively extend from the growth cone, a guidance apparatus located at the tip of neurites, suggesting their role in neurite extension. Here we examined the possible involvement of N-WASP in the neurite extension process. Since verprolin, cofilin homology and acidic region (VCA) of N-WASP is known to be required for the activation of Arp2/3 complex that induces actin polymerization, we prepared a mutant (Deltacof) lacking four amino acid residues in the cofilin homology region. The corresponding residues in WASP had been reported to be mutated in some Wiskott-Aldrich syndrome patients. Expression of Deltacof N-WASP suppressed neurite extension of PC12 cells. In support of this, the VCA region of Deltacof cannot activate Arp2/3 complex enough compared with wild-type VCA. Furthermore, H208D mutant, which has been shown unable to bind to Cdc42, also works as a dominant negative mutant in neurite extension assay. Interestingly, the expression of H208D-Deltacof double mutant has no significant dominant negative effect. Finally, the expression of the Deltacof mutant also severely inhibited the neurite extension of primary neurons from rat hippocampus. Thus, N-WASP is thought to be a general regulator of the actin cytoskeleton indispensable for neurite extension, which is probably caused through Cdc42 signaling and Arp2/3 complex-induced actin polymerization.

Retroperitoneal laparoscopic lateral approach to the lumbar spine: a new approach, technique, and clinical trial

A retroperitoneal laparoscopic (retroperitoneoscopic) lateral approach to achieve decompression for a far lateral disk lesion in the lumbar spine or to remove a paravertebral neurinoma without disrupting the facet is described. The operating space is maintained using a powered mechanical lift and a flat inflatable retractor mainly to make a longitudinal separation between the psoas major and the quadratus lumborum. This technique has been performed successfully in 22 cases using retroperitoneoscopy. The best indications of this new procedure are lateral disk herniation at the L5-S1 level or around the conus medullaris at the L1-L2 level. The described procedure provides adequate exposure necessary for extraforaminal exploration, discectomy, and nerve root decompression, and it is sufficient for treating extreme lateral lumbar herniation localized to the L1-S1 level and spinal nerve root tumors.

Effects of music on mood during bench stepping exercise

This study evaluated the effect of music on the mood of women during exercise. 16 middle-aged women, aged 49.9 +/- 7.53 yr., performed 60-min. bench stepping exercise while listening to Japanese traditional folk song, aerobic dance music, or nonmusic. The subjects reported significantly less fatigue with aerobic dance music and Japanese traditional folk song than with nonmusic. Aerobic dance music was associated with significantly more vigor and less confusion than nonmusic.

Glucocorticoid-induced contractility and F-actin content of human lung fibroblasts in three-dimensional culture

Fibroblast contractility plays a useful role in the wound healing process but contributes to architectural distortion in the lungs. Glucocorticoids (GCs) have been reported to reduce dermal fibroblast contractility, which may result in delaying wound healing, but the effects on lung fibroblasts are unknown. In this study, we examined how human lung fibroblast contractility is altered in the presence of GCs. Lung fibroblast cell lines (n = 5) were established from normal parts of surgically resected lung tissue. The effects of GCs on contractility were investigated with a type I collagen gel contraction assay. Filamentous actin (F-actin) content was detected by confocal microscopy and measured with a fluorescent phalloidin binding assay. GCs augmented fibroblast contraction in a concentration-dependent manner, with an approximate EC(50) of 1.8 x 10(-8) M, whereas other steroid derivatives had no effects. GC contractility needed de novo protein synthesis. The GC-induced increase in contractility was found to be consistent with an increase in F-actin content. In conclusion, lung fibroblast contractility was enhanced with GCs through an upregulation of lung fibroblast F-actin.

Effects of environmental level magnetic field exposures on transcription of CMV immediate early promoter DNA in a cell-free in vitro transcription system

Effects of environmental levels of magnetic fields (MFs) on RNA synthesis have been investigated by using a cell-free system for in vitro transcription. Transcription reaction mixtures containing CMV immediate early promoter DNA plus HeLa cell nuclear extracts were exposed to each of three different MF field strengths, i.e., 10, 50, and 100 microT. Each MF exposed extract was paired with a simultaneous sham-exposure control. The present results show no significant differences in amounts of RNA synthesis in extracts of MF exposed compared with that in the sham controls. This finding is in contrast to results of prior studies of DNA synthesis in cell-free systems that showed MF exposure effects. The results of the present cell-free system studies suggest that the marked differences of MF exposure effects on DNA and on RNA synthesis direct attention to the complexity involved in confirming significant effects of exposures to environmental levels of MFs in biosystems in vivo and in vitro.

Progressive bone resorption after pathological fracture of the femoral neck in Hunter's syndrome

We report a case of Hunter's syndrome associated with a transverse fracture of the left femoral neck after minor trauma, followed by progressive resorption of the femoral head at 12 years of age and a stress fracture of the right femoral neck at 16 years of age. MRI performed at 15 years of age revealed intra-articular low intensity on T1-weighted and T2-weighted images of both hip joints. The MR finding may represent fibrous synovial thickening, which caused pressure erosion of the femoral neck, resultant pathological and/or stress fractures, and subsequent osteonecrosis with rapid absorption of the femoral head.

A case of infantile rhabdomyofibrosarcoma with immunohistochemical, electronmicroscopical, and genetic analyses

A case of infantile rhabdomyofibrosarcoma arising on the buttocks of a 15-month-old boy is reported with histological, immunohistochemical, electronmicroscopical, and cytogenetic findings. Histological examination showed a proliferation of spindle-shaped cells in a fasciculated pattern, with occasional rounded rhabdomyoblastic cells with abundant eosinophilic cytoplasm. Immunohistochemically, the tumor cells expressed desmin and MyoD1 but were only weakly positive for myoglobin. No clear rhabdomyoblastic features were observed by electronmicroscopic examination. Chromosome analysis showed a clone of 46, XY, der(2)t(2;11)(q37;q13), different from any karyotypic abnormality in the original report of this neoplasm. Loss of heterozygosity at 11p15.5, the most frequent genetic alteration in embryonal rhabdomyosarcoma, was not detected. The low degree of striated muscle differentiation and tumor localization supported the diagnosis of infantile rhabdomyofibrosarcoma rather than spindle-cell rhabdomyosarcoma in this case. The present case has been uneventful as of 25 months after surgery. The rather long recurrence-free period, which has not been reported in previous cases, may be attributable to chemotherapy-induced rhabdoid differentiation of the tumor cells.

Involvement of p38 MAP kinase in apoptotic and proliferative alteration in human colorectal cancers

Mitogen-activated protein kinases (MAPKs) have been thought to be involved in tumor development, and recently implicated in the regulation of apoptosis. We assessed the activation of p38 MAPK and extracellular signal-regulated kinases (ERKs) in human colorectal adenocarcinoma by immunoblotting with antibodies raised against each activated form. We also assessed the alteration of proliferative and apoptotic states, and analyzed the association of p38 MAPK with these alterations. The incidence of p38 MAPK activation in the cancer nucleus was significant (p = 0.0215), while ERKs activation was not significant. Proliferating cell nuclear antigen (PCNA)-labeling index and apoptotic index were increased in all cancer tissues. These findings suggested that p38 MAPK was constitutionally activated and was associated with increased proliferative and apoptotic states in colorectal cancers. Serum-deprivation-induced apoptosis in colonic adenocarcinoma cell line was significantly inhibited by SB203580, a specific p38 MAPK inhibitor, suggesting that apoptosis was mediated by the p38 MAPK pathway.

Changes in visibility of intracranial arteries on MRA with normal ageing

We investigated age-related changes in the visibility of intracranial arteries on magnetic resonance angiography (MRA) and the influence of risk factors for stroke. We studied 230 adult patients without specific neurological deficits. MRA was performed using the three-dimensional time-of-flight technique with a spoiled gradient-recalled acquisition sequence. We classified internal carotid artery (IC) and the horizontal (M1) and distal (beyond M2) middle cerebral segments into 4 grades. Linear regression revealed a significant negative relation between age and the quality of demonstration on MRA. For IC and M1, the score was significantly lower in subjects with risk factors than in those without. The distal MCA was poorly seen in patients without a history of hypertension or lacunar infarcts. A marked correlation was observed between visibility and age patients with no history of hypertension, diabetes mellitus and hyperlipidaemia. We suggest that atherosclerotic change and decline in flow velocity with normal ageing are factors leading to decreased visibility on MRA.

Mechanisms of photoreceptor cell apoptosis induced by N-methyl-N-nitrosourea in Sprague-Dawley rats

A single intraperitoneal injection of 75 mg/kg N-methyl-N-nitrosourea (MNU) was given to 50-day-old female Sprague-Dawley rats and examined sequentially 12 and 24 hours, and 3 and 7 days after MNU treatment. Photoreceptor cell death was evoked in all treated rats. After MNU treatment, 7-methyldeoxyguanosine DNA adduct was detected selectively in photoreceptor cell nuclei at 12 hours, followed by photoreceptor cell apoptosis as confirmed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick-end labeling signals which peaked at 24 hours and continued until day 7 when several layers of photoreceptor cell nuclei were left. In apoptosis cascade, down-regulation of Bcl-2 was seen at 12 hours and up-regulation of Bax was seen at 24 hours, and caspase family (caspase 3/CPP32, caspase 6/Mch2, and caspase 8/FLICE protease) activities peaked 72 hours after MNU treatment. Therefore MNU-induced photoreceptor cell death was attributed to DNA adduct formation restricted to photoreceptor cell nuclei leading to photoreceptor cell apoptosis by up-regulation of Bax protein, down-modulation of Bcl-2 protein, and activation of caspases 3, 6, and 8.

Carcinosarcoma of the ampulla of Vater: a case report with immunohistochemical and ultrastructural studies

Carcinosarcoma of the duodenum has not been reported previously, although this type of tumor has been detected in other organs. We present here a case of carcinosarcoma of the duodenum, including immunohistochemical and electron microscopical findings. An ulcerating tumor, located in the duodenal ampullary region, contained two divergent components: ordinary differentiated tubular adenocarcinoma, and sarcomatoid tissue composed of spindle tumor cells. Immunohistochemically, the adenocarcinoma cells were stained with antibodies against epithelial markers including keratin and CA19-9. In contrast, the sarcomatoid tissue was strongly positive for vimentin and was focally positive for myoglobin, keratin, and CA19-9. We speculate that the sarcomatoid element of the carcinosarcoma arose from part of the ordinary adenocarcinoma tissue.

PPAR gamma mediates high-fat diet-induced adipocyte hypertrophy and insulin resistance

Agonist-induced activation of peroxisome proliferator-activated receptor gamma (PPAR gamma) is known to cause adipocyte differentiation and insulin sensitivity. The biological role of PPAR gamma was investigated by gene targeting. Homozygous PPAR gamma-deficient embryos died at 10.5-11.5 dpc due to placental dysfunction. Quite unexpectedly, heterozygous PPAR gamma-deficient mice were protected from the development of insulin resistance due to adipocyte hypertrophy under a high-fat diet. These phenotypes were abrogated by PPAR gamma agonist treatment. Heterozygous PPAR gamma-deficient mice showed overexpression and hypersecretion of leptin despite the smaller size of adipocytes and decreased fat mass, which may explain these phenotypes at least in part. This study reveals a hitherto unpredicted role for PPAR gamma in high-fat diet-induced obesity due to adipocyte hypertrophy and insulin resistance, which requires both alleles of PPAR gamma.

Simultaneous determination of baicalin, wogonoside, baicalein, wogonin, berberine, coptisine, palmatine, jateorrhizine and glycyrrhizin in Kampo medicines by ion-pair high-performance liquid chromatography

An ion-pair high-performance liquid chromatographic method for the simultaneous determination of four flavonoids, namely baicalin, wogonoside, baicalein and wogonin, and four berberine-type alkaloids, namely berberine, coptisine, palmatine and jateorrhizine, and glycyrrhizin in Kampo medicines is described. The analysis can be accomplished within 30 min with a Wakosil-II 5C18 HG column by linear gradient elution using a mobile phase containing aqueous phosphoric acid, sodium dodecyl sulfate and acetonitrile at a flow-rate of 1.0 ml x min(-1), a thermostatic oven at 45 degrees C, and detection at 265 nm. The method was applied to quantifying these components in three Kampo decoctions: Oren-gedoku-to, San'o-shashin-to and Hange-shashin-to. The decoctions were diluted with 65% methanol at the final stage because a large quantity of precipitate, mainly from baicalin and berberine, was formed. The within-day relative standard deviations were less than 2.02% (n=10). The recoveries of these compounds were 90.3-102%. The detection limits of these compounds were 0.02-1.96 microM per injection (5 microl).

Phosphorylation of WAVE downstream of mitogen-activated protein kinase signaling

WAVE is a Wiskott-Aldrich syndrome protein (WASP)-family protein that functions in membrane-ruffling formation induced by Rac, a Rho family small GTPase. Here we report that WAVE is a phosphoprotein whose phosphorylation increases in response to various external stimuli that activate mitogen-activated protein (MAP) kinase signaling. When Swiss 3T3 cells are stimulated with platelet-derived growth factor, electrophoretic mobility shift occurs to WAVE, which reflects hyperphosphorylation. This is perfectly inhibited by the addition of PD98059, a specific inhibitor of MAP kinase kinase. Indeed, the ectopic expression of an activated mutant of MAP kinase kinase induces WAVE mobility shift. When MAP kinase activation is suppressed by PD98059, the intensity of platelet-derived growth factor-induced membrane ruffling is greatly reduced. In various cancer cell lines, the amount of WAVE mobility shift was found to increase significantly, suggesting the importance of WAVE hyperphosphorylation in the formation of membrane ruffles and oncogenic transformation.

Wiskott-Aldrich syndrome protein induces actin clustering without direct binding to Cdc42

WASP (Wiskott-Aldrich syndrome protein) was identified as the gene product whose mutation causes the human hereditary disease Wiskott-Aldrich syndrome. WASP contains many functional domains and has been shown to induce the formation of clusters of actin filaments in a manner dependent on Cdc42. However, there has been no report investigating what domain(s) is(are) important for the function. Here we present for the first time the results of detailed analyses on the domain-function relationship of WASP. First, the C-terminal verprolin-cofilin-acidic domain was shown to be essential for the regulation of actin cytoskeleton. In addition, we found that the clustering of WASP itself is distinct from actin clustering. The partial protein containing the region from the N-terminal pleckstrin homology domain to the basic residue-rich region also clustered especially around the nucleus as wild type WASP without inducing actin clustering. Finally, we obtained the quite unexpected result that a WASP mutant deficient in binding to Cdc42 still induced actin cluster formation, indicating that direct interaction between Cdc42 and WASP is not required for the regulation of actin cytoskeleton. This result may explain why no Wiskott-Aldrich syndrome patients have been identified with a missense mutation in the Cdc42-binding site.

Correlation of unilateral thoracoscopic lung volume reduction with improvement in lung function and exercise performance in patients with severe pulmonary emphysema

This study was conducted to investigate the correlation of thoracoscopic lung volume reduction to changes in pulmonary function and exercise performance in patients with pulmonary emphysema. Unilateral thoracoscopic lung volume reduction treatment was performed in 30 patients with severe pulmonary emphysema. If large bullae were present, they were excised using an endoscopic stapling device, and the emphysematous pleura was contracted by neodymium:yttrium-aluminium-garnet laser to reduce the volume of nonfunctional lung air space. Pulmonary function and incremental exercise tests were performed before and at least 3 months after treatment. Follow-up functional evaluation showed a highly significant improvement in the forced expiratory volume in 1s (FEV1), forced vital capacity, static compliance, and maximal oxygen uptake. The functional residual capacity as measured by the gas dilution method (FRCgas), was unchanged; however, it was found to be decreased significantly when measured by body plethysmograph (FRCbox). Positive correlations existed between the reduction in FRCbox and the increase in FEV1 (r = 0.586, P = 0.0042) and maximal oxygen uptake (r = 0.550, P = 0.018). Pulmonary ventilation and exercise ability in patients with pulmonary emphysema were improved in a volume-dependent manner by thoracoscopic lung volume reduction. These findings indicate that patients with a preoperative trapped gas volume level exceeding 11 would be ideal candidates for thoracoscopic lung volume reduction.

Distinct roles of profilin in cell morphological changes: microspikes, membrane ruffles, stress fibers, and cytokinesis

Here we report the functional importance of profilin in various actin-mediated morphological changes using H119E mutant profilin I, which is deficient only in actin binding. In the case of actin-protrusive structures from the plasma membrane, H119E-profilin was shown to suppress the formation of Cdc42-induced actin microspikes and Rac-induced membrane ruffles. Conversely, Rho-induced stress fiber formation seemed to occur independently of H119E-profilin introduction. Furthermore, H119E-profilin blocked cleavage furrow ingression and subsequent adhesion to the substratum during cell division, a process in which actin plays indispensable roles.

An artificial esophagus constructed of cultured human esophageal epithelial cells, fibroblasts, polyglycolic acid mesh, and collagen

We have been developing an artificial esophagus constructed of autologous esophageal component cells by cell culture. Because human esophageal epithelial cells are stratified in 20 layers, we attempted to construct an artificial esophageal epithelium 20 twenty layers thick. In in vitro experiments, we investigated how keratinocyte growth factor produced by fibroblasts accelerates the proliferation and differentiation of epithelial cells. Esophageal epithelial cells were cultured on collagen sheets in which dermal fibroblasts (0, 1, 4, 8 x 10(5) cells/ml of collagen) were embedded. In cultured epithelial cells on collagen gels without fibroblasts, 2.1 layer stratification was observed on the 21st day. With 1 x 10(5) fibroblasts/ml of collagen, 3.0 layer stratification was observed, 5.0 layers with 4 x 10(5) fibroblasts, and 18.1 layers with 8 x 10(5) fibroblasts. The degree of epithelial cell stratification was thus correlated with the number of embedded fibroblasts. Tubes constructed of a polyglycolic acid mesh frame, a collagen layer with esophageal fibroblasts, and an inner layer of esophageal epithelial cells were transplanted into muscle flaps of athymic rats. The luminal structures were observed to be patent without stenosis for 14 days. Histology of the epithelium revealed 20 layers of stratification. We thus succeeded in constructing epithelium similar to human esophageal epithelium. In the future we will attempt to use the tubular structures as a substitute for the esophagus after esophagectomy.

Hospital-based historical cohort study of 234 histologically proven Japanese patients with IPF

BACKGROUND AND AIM OF THE WORK

Variable clinical courses have been recognized in patients with idiopathic pulmonary fibrosis (IPF), but the disease is known to have a fundamentally unfavorable outcome. In addition, we have yet to fully understand whether the regional or population differences are negligible or not. Therefore, we analyzed the clinical outcomes in Japanese IPF patients in a hospital-based historical cohort study.

METHODS

A questionnaire was used to collect records for retrospective analysis of the IPF patients. We analyzed data collected from 51 hospitals and clinics in Japan on 234 Japanese IPF patients (males 170, females 64) with IPF who had been followed up after diagnosis.

RESULTS

1. Five and ten years after the detection of exertional dyspnea, the overall survival rates were 41.0% and 20.1%, respectively. A higher age at the time of detection (over 59) was related to a decrease in survival rates. 2. The incidence of complications was no higher in the corticosteroid-treated cases than in the untreated cases. The effects of corticosteroid treatment on survival was not confirmed in this type of study.

CONCLUSIONS

The survival rates of histologically proven Japanese patients with IPF were similar to the rates previously reported in different populations. Age at the detection of exertional dyspnea was critical in terms of the survival rate.

The pleckstrin homology domain of the Wiskott-Aldrich syndrome protein is involved in the organization of actin cytoskeleton

In this study, we investigated the role of the pleckstrin homology (PH) domain of the Wiskott-Aldrich syndrome protein (WASP) in the regulation of actin cytoskeleton, which is defective in patients with Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT). Overexpression of the WASP in COS-7 cells cultured in the presence of fetal calf serum (FCS) resulted in large cluster formation of polymerized actin and WASP in the cytoplasm. In contrast, when the WASP transfected cells were cultured in the absence of FCS, activation with PMA or EGF was required to induce cluster formation. Overexpression of WASP with a missense mutation in the N-terminus of the PH domain failed to induce the large cluster formation in COS-7 cells even in the presence of FCS. We also found that phosphatidylinositol 4,5-bisphosphate (PIP(2)), which is known to regulate the actin cytoskeleton, binds to the PH domain of WASP, and the binding was abolished by the introduction of a missense mutation into the N-terminus but not the C-terminus of the PH domain. Together with the observations that most of the missense mutations observed in patients with WAS and XLT are located within the PH domain, these results indicate that the PH domain of WASP plays important roles in the regulation of actin cytoskeleton and suggested that the binding of PIP(2) to the PH domain is necessary for WASP to function properly.

Late recurrence of acinic cell carcinoma of the parotid gland

Acinic cell carcinoma of the salivary glands is a rare cancer representing a low grade malignancy. The recurrence of a tumor is sometimes encountered, usually within 5 years of initial operation. We describe an unusual recurrence after a long interval following primary surgery. In 1987, a 60-year-old woman underwent excision of a mass in the superficial lobe of the right parotid gland under the preoperative diagnosis of a benign tumor. A histologic diagnosis of acinic cell carcinoma was made by examining sections from the resected mass. The patient noted several small nodules in the right parotid region in 1995, but she did not visit our clinic until 1998 when tenderness developed. A locally recurrent tumor and cervical lymph nodes containing metastases were resected and postoperative radiotherapy was given 11 years after the first operation. At least 10 years of follow-up may be necessary for patients with acinic cell carcinoma because of slow-tumor growth.

Hyperthermic isolated regional perfusion for the treatment of osteosarcoma in the lower extremity

BACKGROUND

In order to reduce the systemic toxity of cisplatin and to increase the effect on the local tumor, facilitating limb-preserving procedures, we have been using hyperthermic isolated regional perfusion (HIRP) for the treatment of osteosarcoma in addition to preoperative chemotherapy.

MATERIALS AND METHODS

Twenty patients with an osteosarcoma in a lower extremity were treated with both preoperative chemotherapy and HIRP.

RESULTS

The chemotherapeutic effects of preoperative chemotherapy with HIRP was grade III in 6, and grade IV (no viable cell areas observed) in 7. The surgical margins could be reduced in these 13 cases of good responders showing over 90% necrosis (grade III or grade IV), which mainly involved postnecrotic fibrosis and osteosclerosis.

CONCLUSION

HIRP can help to control the tumor locally. A more conservative operation was then possible in cases of good responders to preoperative chemotherapy with HIRP.

Identification of two human WAVE/SCAR homologues as general actin regulatory molecules which associate with the Arp2/3 complex

WAVE/SCAR protein was identified as a protein which has similarity to WASP and N-WASP, especially in its C terminal. Recently, WAVE/SCAR protein has been shown to cooperate with the Arp2/3 complex, a nucleation core for actin polymerization in vitro. However, in spite of its general function, WAVE/SCAR expression is mainly restricted to the brain, suggesting the existence of related molecule(s). We here identified two human WAVE/SCAR homologues, which cover other organs. We named the original WAVE1 and newly identified ones WAVE2 and WAVE3. WAVE2 had a very wide distribution with strong expression in peripheral blood leukocytes and mapped on chromosome Xp11.21, next to the WASP locus. WAVE3 and WAVE1 had similar distributions. WAVE3 was strongly expressed in brain and mapped on chromosome 13q12. WAVE1 was mapped on chromosome 6q21-22. Ectopically expressed WAVE2 and WAVE3 induced actin filament clusters in a similar manner with WAVE1. These actin cluster formations were suppressed by deletion of their C-terminal VPH (verproline homology)/WH2 (WASP homology 2) domain. Further, WAVE2 and WAVE3 associate with the Arp2/3 complex as does WAVE1. Our identification of WAVE homologues suggests that WAVE family proteins have general function for regulating the actin cytoskeleton in many tissues.

Microsatellite alterations in various sarcomas in Japanese patients

To determine the usefulness of microsatellite analysis in the differential diagnosis of various sarcomas, we investigated microsatellite alterations at 12 microsatellite loci by polymerase chain reaction and electrophoresis in 39 Japanese patients with sarcomas. The sarcomas were: osteosarcoma, Ewing's sarcoma, chondrosarcoma, liposarcoma, leiomyosarcoma, epithelioid leiomyosarcoma, rhabdomyosarcoma, synovial sarcoma, and malignant fibrous histiocytoma. We also examined ten leiomyomas to contrast with leiomyosarcoma. No microsatellite instability (MSI) or loss of heterozygosity (LOH) were found in Ewing's sarcoma, chondrosarcoma, epithelioid leiomyosarcoma, malignant fibrous histiocytoma, and leiomyoma. Only three patients, one each with liposarcoma, leiomyosarcoma, and synovial sarcoma, manifested MSI, whereas, osteosarcoma, liposarcoma, leiomyosarcoma, rhabdomyosarcoma, and synovial sarcoma manifested LOH, with an incidence of 43%, 14%, 86%, 20%, and 75%, respectively. Interestingly, three patients showed unusual patterns of LOH, probably due to intratumoral heterogeneity. Kaplan-Meier analysis revealed that LOH on 11p was predictive of poor prognosis in osteosarcoma. The low incidence of MSI indicates that MSI is not necessary for neoplastic transformation in sarcomas. However, the very high incidence of LOH in leiomyosarcoma indicates that microsatellite analysis may serve for the differential diagnosis of leiomyosarcoma versus leiomyoma. Microsatellite analysis may also predict prognosis in osteosarcoma.

Simultaneous determination of ephedrine, pseudoephedrine, norephedrine and methylephedrine in Kampo medicines by high-performance liquid chromatography

A simultaneous high-performance liquid chromatographic method for the determination of ephedrine, pseudoephedrine, norephedrine and methylephedrine (ephedrine alkaloids) in Kampo medicines which contain Ephedrae Herba was established. The analysis can be accomplished within 25 min with a Wakosil-II 5C18 HG column by isocratic elution using a mixture of water, acetonitrile and sodium dodecyl sulfate (65:35:0.4) as the mobile phase at a flow-rate of 1.0 ml min(-1), and detection at 210 nm. The detection limits of ephedrine alkaloids are 0.37-1.06 microM per injection (5 microl). This method was applied to analyze the quantities in eight Kampo decoctions; Mao-to, Makyo-yokukan-to, Makyo-kanseki-to, Yokuinin-to, Sho-seiryu-to, Keima-kakuhan-to, Kakkon-to and Kakkon-to-ka-senkyu-sin'i. The concentration (per Ephedrae Herba gram) of ephedrine alkaloids was higher in the Makyo-kanseki-to decoction than in the others. Calcium sulfate from Gypsum Fibrosum raised ephedrine alkaloids dissolution in the Makyo-kanseki-to decoction.

ret/PTC expression may be associated with local invasion of thyroid papillary carcinoma

BACKGROUND AND OBJECTIVES

The exact role of ret/PTC in the development of papillary carcinoma remains unclear. Expression of the ret/PTC oncogene was examined immunohistochemically to address its role in the progression of thyroid carcinomas.

METHODS

Paraffin-embedded samples from 34 clinically evident thyroid papillary carcinomas and 19 occult papillary carcinomas were analyzed using an antibody raised against the ret tyrosine kinase domain.

RESULTS

Expression of ret/PTC was demonstrated in 6/19 (32%) occult carcinomas. The frequency of expression of ret/PTC in clinically evident carcinomas in 16/34 (47%) was significantly higher than in normal tissues (0%) and follicular adenomas (1/14, 7%, P < 0.01).ret/PTC expression was observed more frequently in the peripheral areas of clinically evident carcinomas (P < 0.01). Although there was no correlation of ret/PTC expression with tumor size, lymph node metastasis, or distant metastasis, the incidence of ret/PTC expression in tumors with extrathyroidal invasion (13/19, 68%) was significantly higher than those without extrathyroidal invasion (3/15, 20%, P < 0.01). Local invasion was found in none of the occult carcinomas. The frequency of expression in occult carcinomas was significantly lower than in clinically evident carcinomas with extrathyroidal invasion (P < 0.05).

CONCLUSIONS

The ret/PTC oncogene may be involved in the local invasion of thyroid papillary carcinomas.

Microbial system for polysaccharide depolymerization: enzymatic route for xanthan depolymerization by Bacillus sp. strain GL1

An enzymatic route for the depolymerization of a heteropolysaccharide (xanthan) in Bacillus sp. strain GL1, which was closely related to Brevibacillus thermoruber, was determined by analyzing the structures of xanthan depolymerization products. The bacterium produces extracellular xanthan lyase catalyzing the cleavage of the glycosidic bond between pyruvylated mannosyl and glucuronyl residues in xanthan side chains (W. Hashimoto et al., Appl. Environ. Microbiol. 64:3765-3768, 1998). The modified xanthan after the lyase reaction was then depolymerized by extracellular beta-D-glucanase to a tetrasaccharide, without the terminal mannosyl residue of the side chain in a pentasaccharide, a repeating unit of xanthan. The tetrasaccharide was taken into cells and converted to a trisaccharide (unsaturated glucuronyl-acetylated mannosyl-glucose) by beta-D-glucosidase. The trisaccharide was then converted to the unsaturated glucuronic acid and a disaccharide (mannosyl-glucose) by unsaturated glucuronyl hydrolase. Finally, the disaccharide was hydrolyzed to mannose and glucose by alpha-D-mannosidase. This is the first complete report on xanthan depolymerization by bacteria. Novel beta-D-glucanase, one of the five enzymes involved in the depolymerization route, was purified from the culture fluid. This enzyme was a homodimer with a subunit molecular mass of 173 kDa and was most active at pH 6.0 and 45 degrees C. The enzyme specifically acted on xanthan after treatment with xanthan lyase and released the tetrasaccharide.

Loss of heterozygosity in actinic keratosis, squamous cell carcinoma and sun-exposed normal-appearing skin in Japanese: difference between Japanese and Caucasians

Actinic keratosis (AK) has been considered to be a precursor of squamous cell carcinoma (SCC). However, based on epidemiological and molecular studies, it has become questionable to regard AK as a precancerous lesion. We analyzed 37 AKs and 14 sporadic SCCs using six microsatellite markers in order to elucidate if any genetic instability or loss of heterozygosity (LOH) was implicated in tumorigenesis and progression of non-melanocytic skin tumor. Microsatellite instability (MSI) was not found in any of the AKs or SCCs indicating that genetic instability has little implication in the tumorigenesis of sporadic non-melanocytic skin tumor. LOH was found in seven of 37 lesions of AK, but in only one of 14 lesions of SCC. The significantly lower frequency of LOH than that previously reported in Caucasians suggested that the molecular pathogenesis of AKs and SCCs might be different between Japanese and Caucasians. The higher frequency of LOH in AKs than in SCCs in the present study supported the previous epidemiological and molecular studies that AK was not likely to proceed to SCC. LOH was also demonstrated in histologically normal-appearing skin in three cases suggesting that genetic alteration occurs before histological change appears in the sun-exposed skin.

Melanin pigmented oncocytic metaplasia of the nasopharynx

A 64-year-old man presented with a history of discomfort of the throat of a few weeks' duration. Nasoscopic examination revealed multiple small, brown pigmentations at the left suprapharynx, the base of the left nasal cavity and the pharyngeal openings of the auditory tube on both sides. Microscopically, the lesion showed a glandular pattern of oncocytic epithelium with abundant pigmented granules and melanophages in the surrounding stroma. Immunohistochemically, the dendritic cells in the basal layer were positive for S-100 protein. Electron microscopic study revealed numerous fully melanized melanosomes and hypertrophied mitochondria in the oncocytic cells. Oncocytic cells do not produce melanin for themselves, melanin granules apparently being transferred from the adjacent dendritic cells to the oncocytic cells.

The interaction between N-WASP and the Arp2/3 complex links Cdc42-dependent signals to actin assembly

Although small GTP-binding proteins of the Rho family have been implicated in signaling to the actin cytoskeleton, the exact nature of the linkage has remained obscure. We describe a novel mechanism that links one Rho family member, Cdc42, to actin polymerization. N-WASP, a ubiquitously expressed Cdc42-interacting protein, is required for Cdc42-stimulated actin polymerization in Xenopus egg extracts. The C terminus of N-WASP binds to the Arp2/3 complex and dramatically stimulates its ability to nucleate actin polymerization. Although full-length N-WASP is less effective, its activity can be greatly enhanced by Cdc42 and phosphatidylinositol (4,5) bisphosphate. Therefore, N-WASP and the Arp2/3 complex comprise a core mechanism that directly connects signal transduction pathways to the stimulation of actin polymerization.

Simultaneous high-performance liquid chromatographic determination of puerarin, daidzin, paeoniflorin, liquiritin, cinnamic acid, cinnamaldehyde and glycyrrhizin in Kampo medicines

We report a high-performance liquid chromatographic method to determine the quantities of puerarin, daidzin, paeoniflorin, liquiritin, cinnamic acid, cinnamaldehyde and glycyrrhizin in Kampo medicine. All seven compounds were separated in less than 30 min with a Wakosil-II 5C18 AR column by linear gradient elution using 0.01% (v/v) phosphoric acid acetonitrile (0 min 90:10, 10 min 88:12, 22 min 70:30, 30 min 30:70) as the mobile phase at a flow-rate of 1.0 ml/min(-1), and detection at 250 nm. The detection limits of these compounds are 0.15-0.3 microM with response linearity. This method was applied to determine the quantities in eight Kampo decoctions; Mao-to, Makyo-yokukan-to, Makyo-kanseki-to, Yokuinin-to, Sho-seiryu-to, Keima-kakuhan-to, Kakkon-to and Kakkon-to-ka-senkyu-sin'i. Glycyrrhizin content was lower in both the decoction and the methanol-diluted decoction of Sho-seiryu-to compared with the others. Low pH due to organic acids of Schisandrae fructus in the decoction caused inhibition for glycyrrhizin dissolution in Sho-seiryu-to.

Genetic polymorphisms of drug-metabolizing enzymes and susceptibility to head-and-neck squamous-cell carcinoma

We have investigated the association between the polymorphisms of drug-metabolizing enzymes and susceptibility to head-and-neck squamous-cell carcinoma (HNSCC). PCR-based analysis was performed on 145 Japanese patients and 164 healthy Japanese controls to determine genotypes of polymorphisms in CYP1A1, CYP2E1, GSTM1, GSTP1, and NAT2. Patients and controls were compared by multivariate analysis. The CYP1A1 Val/Val genotype was seen more frequently in patients than in controls [odds ratio (OR) 4.1, p = 0.038). The frequency of the slow plus intermediate NAT2 genotypes was also higher in patients (OR 2.0, p = 0.039). When we analyzed the distributions of the genotypes in 69 laryngeal and 45 pharyngeal cancer patients, laryngeal cancer patients had a higher frequency of NAT2 slow or intermediate genotype (OR 2.7, p = 0.011) and GSTP1 AA genotype (OR 2.4, p = 0.047) than controls. Pharyngeal cancer patients had a higher frequency of the CYP1A1 Val/Val genotype than controls (OR 5.7, p = 0.034), suggesting that different organs may be responsive to different chemicals from the environment. Furthermore, 23 patients who developed multiple cancers (HNSCC plus other) were compared with 115 patients with HNSCC alone. There was no significant difference in the polymorphisms between the 2 groups, though excessive alcohol consumption (more than 50 g/day of ethanol) appeared to be a risk factor for multiple cancers (p = 0.053).

[Changes in visualization of cerebral MR angiography with normal aging]

MR angiograms from 200 neurologically normal subjects aged 30 to 79 years were analyzed to assess the influence of aging and hypertension on the degree of the--visualization of the cerebral arteries. The degree of MR visualization of the cerebral arteries, including the IC, M 1, and distal MCA, was evaluated on a 4-degree scale. IC and M 1 differ in appearance. The MR gradings of each cerebral arteries showed a significant (p < 0.001) negative correlation with age. Hypertension, which is a risk factors for arteriosclerosis, significantly reduced MR grade. The degree of visualization of M 1 and the distal MCA decreased significantly with age in the normotensive group. Therefore, the decrease visualization of the cerebral arteries appears to involve not only cerebral arteriosclerosis but other factors associated with aging.

Genetic polymorphisms of drug-metabolizing enzymes and susceptibility to head-and-neck squamous-cell carcinoma

We have investigated the association between the polymorphisms of drug-metabolizing enzymes and susceptibility to head-and-neck squamous-cell carcinoma (HNSCC). PCR-based analysis was performed on 145 Japanese patients and 164 healthy Japanese controls to determine genotypes of polymorphisms in CYP1A1, CYP2E1, GSTM1, GSTP1, and NAT2. Patients and controls were compared by multivariate analysis. The CYP1A1 Val/Val genotype was seen more frequently in patients than in controls [odds ratio (OR) 4.1, p = 0.038). The frequency of the slow plus intermediate NAT2 genotypes was also higher in patients (OR 2.0, p = 0.039). When we analyzed the distributions of the genotypes in 69 laryngeal and 45 pharyngeal cancer patients, laryngeal cancer patients had a higher frequency of NAT2 slow or intermediate genotype (OR 2.7, p = 0.011) and GSTP1 AA genotype (OR 2.4, p = 0.047) than controls. Pharyngeal cancer patients had a higher frequency of the CYP1A1 Val/Val genotype than controls (OR 5.7, p = 0.034), suggesting that different organs may be responsive to different chemicals from the environment. Furthermore, 23 patients who developed multiple cancers (HNSCC plus other) were compared with 115 patients with HNSCC alone. There was no significant difference in the polymorphisms between the 2 groups, though excessive alcohol consumption (more than 50 g/day of ethanol) appeared to be a risk factor for multiple cancers (p = 0.053).

[Changes in Bruch's membrane in experimental hypercholesteremia in rats]

PURPOSE

We investigated the effect of high cholesterol diet for the aging changes in Bruch's membrane of rats.

METHODS

After feeding a 4% cholesterol diet for 15 weeks to three young rats 3 months old and four aged rats 23 months old, we observed the morphological changes of Bruch's membrane by electron microscopy, and made a comparison with rats fed an ordinary diet.

RESULTS

In one young rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris formed multiple folds separated from the plasma membrane of the endothelium and showed lamellar thickening and crack in some areas. The elastic fiber layer in Bruch's membrane disappeared partly and some new microfibrils appeared. In one aged rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris showed more lamellar thickening with lumps in some parts. Compared with rats fed an ordinary diet, rats fed a high-cholesterol diet showed thickening of the basement membrane and the changes were more severe.

CONCLUSIONS

Our data indicated that high-cholesterol diet might promote age-related changes of Bruch's membrane.

[Age-related changes in Bruch's membrane in rats]

PURPOSE

We investigated rats were worth the experimental animal on the aging changes in Bruch's membrane.

METHODS

We did an ultramicromorphological study on the aging changes in Bruch's membrane, in male Sprauge-Dawley rats at 1,6,12 and 27 months after their birth.

RESULTS

With the aging, the basement membranes on both sides of Bruch's membrane have become thick. At 6 months of age, the basement membranes of the endothelial cells of the choriocapillaris were found to be multilayered and cracked and pseudopodia of the endothelium were also observed toward the retinal pigment epithelium. At 12 months of age, we found vacuoles in the basal portion of the retinal pigment epithelium, as well as fibrillae and a part of the process of a cell in the outer collagenous zone correspond with the portion of the multilayered and cracked basement membranes of the endothelial cells of the choriocapillaris. At the age of 27 months, the basement membranes were thicker and a basal laminar deposit was seen. Prominent changes such as disappearance of the elastic fibers and increase of the collagenous fibers and fibrillae were also seen in some portions.

CONCLUSIONS

Thus, the aging changes in Bruch's membrane of rats were remarkably reinforced in accordance with the age, it were appeared these rats were worth the experimental animal.

Enzymatic and genetic bases on assimilation, depolymerization, and transport of heteropolysaccharides in bacteria

When microorganisms utilize macromolecules for their growth, they commonly produce extracellular depolymerization enzymes and then incorporate the depolymerized low-molecular-weight products. Assimilation of heteropolysaccharides (gellan and xanthan) by Bacillus sp. GL1 depends on this generally accepted mechanism. On the other hand, Sphingomonas sp. A1 represents an unexplored specific and interesting system for macromolecule assimilation. In the presence of heteropolysaccharide (alginate), the bacterium forms a mouthlike pit on its cell surface and directly incorporates the macromolecule using a novel ATP-binding cassette transporter (ABC transporter). In this review, we discuss enzymatic and genetic bases on the depolymerization and assimilation routes of heteropolysaccharides in bacteria, with particular emphasis on the novel incorporation system for macromolecules, characteristic post-translational modification processes of polysaccharide lyases and on the mouthlike pit structure on the bacterial cell surface.

WAVE, a novel WASP-family protein involved in actin reorganization induced by Rac

Rac is a Rho-family small GTPase that induces the formation of membrane ruffles. However, it is poorly understood how Rac-induced reorganization of the actin cytoskeleton, which is essential for ruffle formation, is regulated. Here we identify a novel Wiskott-Aldrich syndrome protein (WASP)-family protein, WASP family Verprolin-homologous protein (WAVE), as a regulator of actin reorganization downstream of Rac. Ectopically expressed WAVE induces the formation of actin filament clusters that overlap with the expressed WAVE itself. In this actin clustering, profilin, a monomeric actin-binding protein that has been suggested to be involved in actin polymerization, was shown to be essential. The expression of a dominant-active Rac mutant induces the translocation of endogenous WAVE from the cytosol to membrane ruffling areas. Furthermore, the co-expression of a deltaVPH WAVE mutant that cannot induce actin reorganization specifically suppresses the ruffle formation induced by Rac, but has no effect on Cdc42-induced actin-microspike formation, a phenomenon that is also known to be dependent on rapid actin reorganization. The deltaVPH WAVE also suppresses membrane-ruffling formation induced by platelet-derived growth factor in Swiss 3T3 cells. Taken together, we conclude that WAVE plays a critical role downstream of Rac in regulating the actin cytoskeleton required for membrane ruffling.

Usefulness of heavily T2-weighted magnetic resonance imaging in patients with cerebellopontine angle tumors

OBJECTIVE

Heavily T2-weighted magnetic resonance imaging (MRI) has been reported to be useful for the diagnosis of lesions of the inner ear or its central connections. We evaluated the usefulness of heavily T2-weighted MRI in 18 patients with cerebellopontine angle tumors.

METHODS

The lesions were acoustic neuromas in 14 patients and meningiomas in 4 patients. The findings of heavily T2-weighted MRI were compared with those of three-dimensional T1-weighted gradient field echo MRI.

RESULTS

An accurate description of the situation of the tumor in the internal auditory canal (IAC) was possible, because the inner ear was clearly shown on the heavily T2-weighted magnetic resonance images. We could therefore detect the acoustic neuromas located at the fundus of the IAC and the meningiomas growing into the IAC. The residual tumor in the IAC can be shown postoperatively. It was difficult to demonstrate these findings using three-dimensional T1-weighted gradient field echo MRI because of the poor presentation of the petrous bone structures. The lower cranial nerves and the VIIth and VIIIth cranial nerves were more clearly demonstrated by heavily T2-weighted MRI than by three-dimensional T1-weighted gradient field echo MRI. Using heavily T2-weighted MRI, the VIIth and VIIIth cranial nerves of the lesion side were demonstrated in half of the patients with acoustic neuromas smaller than 2.5 cm.

CONCLUSION

We conclude that heavily T2-weighted MRI is useful to detect the relationship among the tumor, the IAC, the inner ear, and the surrounding cranial nerves.

Molecular cloning of two genes for beta-D-glucosidase in Bacillus sp. GL1 and identification of one as a gellan-degrading enzyme

In the bacterium Bacillus sp. GL1, gellan is depolymerized to give a tetrasaccharide by extracellular gellan lyase and then the tetrasaccharide is converted to constituent monosaccharides by intracellular glycosidases. Two genes encoding one of the glycosidases, beta-D-glucosidase (Bgl), were cloned in a genomic DNA library of the bacterium constructed in Escherichia coli and nucleotide sequences of the genes were determined. One of the genes, termed bglA, contained an open reading frame (ORF) consisting of 1344 base pairs coding a polypeptide (BglA) with a molecular mass of 51 kDa and the other, termed bglB, 2268 base pairs coding a protein (BglB) with a molecular mass of 82 kDa. By homology analyses of the ORFs against protein sequence databases, beta-D-glucosidase A (BglA) and beta-D-glucosidase B (BglB) were found to be classified into subfamilies BGA and BGB of cellulase family BG, respectively. BglA and BglB purified from E. coli were monomeric enzymes with molecular masses of 50 and 82 kDa and most active at pH 6.0 and 8.0, respectively. BglA showed broader substrate specificity than BglB. Only BglA acted on the tetrasaccharide produced from gellan by gellan lyase and released glucose from the molecule.

The essential role of profilin in the assembly of actin for microspike formation

Profilin was first identified as an actin monomer binding protein; however, recent reports indicate its involvement in actin polymerization. To date, there is no direct evidence of a functional role in vivo for profilin in actin cytoskeletal reorganization. Here, we prepared a profilin mutant (H119E) defective in actin binding, but retaining the ability to bind to other proteins. This mutant profilin I suppresses actin polymerization in microspike formation induced by N-WASP, the essential factor in microspike formation. Profilin associates both in vivo and in vitro with N-WASP at proline-rich sites different from those to which Ash/Grb2 binds. This association between profilin and N-WASP is required for N-WASP-induced efficient microspike elongation. Moreover, we succeeded in reconstituting microspike formation in permeabilized cells using profilin I combined with N-WASP and its regulator, Cdc42. These findings provide the first evidence that profilin is a key molecule linking a signaling network to rapid actin polymerization in microspike formation.

Collision tumor of cutaneous malignant melanoma and basal cell carcinoma

An extremely rare case of a collision tumor of malignant melanoma (MM) and basal cell carcinoma (BCC) located in the temporal scalp of a 78-year-old male is reported. Microscopic examination revealed a collision tumor consisting of the nodular type, Clark's level IV MM, and a pigmented BCC. The tumor was studied by immunohistochemistry and was analyzed for point mutations of codons 12 and 61 of H-ras, K-ras and N-ras oncogenes. Tumor cells of the MM were positive for S-100 protein, HMB-45 and vimentin, but negative in the BCC. The malignant melanoma possessed an activating A to T transversion in codon 61 of N-ras gene, which is the code for leusine instead of glutamine. This is the first report of ras oncogene mutation in such a collision tumor. MM and BCC are clearly different in terms of histological, immunohistochemical and ras gene mutation analyses. These findings support the view that the association of MM and BCC in this collision tumor is a chance occurrence.