Amplification of c-myc, K-sam, and c-met in gastric cancers: detection by fluorescence in situ hybridization

Gene amplifications of c-myc, K-sam, and c-met were examined in cancer nuclei isolated from 154 primary gastric adenocarcinomas by fluorescence in situ hybridization (FISH) using cosmid probes for 8q24 (c-myc locus) and 7q31 (c-met), as well as a DNA probe for K-sam synthesized by PCR. The results were compared with those of Southern blot analysis. Dual-color FISH using gene locus and chromosome-specific probes detected gene amplifications of c-myc in 24 tumors (15.5%), c-met in 6 tumors (3.9%), and K-sam in 3 tumors (2.9%). The six tumors with c-myc amplification had also been found to have amplified c-erbB-2 in our previous study, and coamplification of c-myc and c-met was found in two other tumors. This technique also differentiated the amplified genes on the homogeneous staining region (HSR) and on double minute chromosomes (DMs) in metaphase spreads and interphase nuclei of cell lines established from poorly differentiated adenocarcinomas, KATO III, SNU 16, and HSC 39. Examination of FISH images of these cell lines suggested that the high-level amplifications of c-myc found in primary tumors occurred mainly on DM in four tumors and on HSR in one, and those of K-sam occured on DM in two tumors and on HSR in one. No high-level amplification of c-met was found. These high-level amplifications were also detected in formalin-fixed, paraffin-embedded tissues from primary gastric tumors and metastatic lymph nodes, in some of which heterogeneity of gene amplification was demonstrated within the same tumor. We conclude that FISH is an important tool for examining the proto-oncogene aberrations in intact cells in solid tumors.     

Histopathological examination of transurethral electrovaporization of the prostate

Transurethral electrovaporization of the prostate (TVP) has been devised to eliminate prostatic tissue by electric vaporization and to create a dry coagulation layer beneath to minimize bleeding from the site of TVP. However, vaporization induces degeneration due to thermal coagulation deep in the tissue beneath the vaporized layer, and local tissue damage is thus greater than that caused by the standard transurethral resection of prostate (TURP) loop. Since this results in difficulty with histopathological examination, the percentages of tissue-diagnosable area were determined in sections resected using various vaporization electrodes (Roller Loop, Band & Wedge Loop). The percentage of tissue-diagnosable area was 92.0 +/- 3.3% with the standard TUR loop, 2.4 +/- 0.9% with the Roller Loop, 42.7 +/- 21.1% with the Band Loop, and 39.7 +/- 24.4% with the Wedge Loop. Concerning speed of resection, the best vaporization effect was obtained when the speed of operation was 1/2 or 1/3 that with the standard TUR loop. Since the region in which tissue diagnosis was smaller with the vaporization electrode than with standard TURP, more careful examination was required for diagnosis of incidental cancers. Therefore, postoperative observation by PSA measurement appeared to be important.     

An artificial retina chip made of a 128×128 pn-npvariable-sensitivity photodetector array

An artificial retina chip is an image detection device that, like biological retinas, can extract essential features directly from projected images. This paper presents an artificial retina chip consisting of a 128×128 array of pn-np variable-sensitivity photodetectors (VSPD's). This photodetector (PD) utilizes pn junctions and thus avoids the rather inflexible memory effect encountered in our previously reported device, which used Schottky contacts in a metal-semiconductor-metal (MSM) configuration. We introduce a novel “filter division” method for arbitrary two-dimensional (2-D) filter operation, and successfully employ it in a 2-D edge extraction task     

Quantitative analysis of the gustatory evoked potentials in the guinea pig

Gustatory evoked potentials were studied in anesthetized guinea pigs to develop an objective and quantitative taste examination for patients with taste disorders. A positive wave was recorded by the application of NaCl, HCl or quinine hydrochloride solution. There was little difference in latency, duration and waveform among these three solutions. No apparent change in activity was seen after the application of sucrose solution or distilled water. The gustatory evoked potentials that excluded the influence of the trigeminal nerve innervating the tongue surface were able to be reproducibly recorded on either the cortical surface or the skull surface. There was a linear relationship between logarithmic values of potential amplitude and those of taste solution concentration. Therefore, it is suspected that the quantitative evaluation of taste detection is possible by measuring the taste solution concentration-potential amplitude relationship.     

A Japanese family with paramyotonia congenita which has a mutation in the muscle sodium channel gene

We report here a Japanese family with paramyotonia congenita. The proband was a 42-year-old woman (case 1), who noticed muscle stiffness and weakness in the cold since the age of 7 years. These symptoms were alleviated by warming. Her eldest son (case 2) also experienced similar symptoms, while her younger son and daughter were healthy. Neurological examination in case 1 revealed mild weakness in facial and neck muscles. Cold-induced muscle stiffness and weakness were present. Electromyography showed myotonic discharges, intensified by cooling or repetitive exercise. The amplitude of the compound muscle action potentials was also reduced by the repetitive exercise and cooling. Serum chemistry including potassium and CK was normal. Molecular analysis of SCN4A (exon22-24) by SSCP and nucleotide sequencing revealed a C-to-T transition at nucleotide 3,938, causing a substitution of 1313methionine of threonine in case 1. This mutation was confirmed by PCR-RFLP with a mismatched primer; the proband (case 1) and her eldest son (case 2) had a heterozygous mutation, while the other family members did not. This is the first report that a mutation in SCN4A was identified in a Japanese family with paramyotonia congenita.     

Production and secretion of adrenomedullin from glial cell tumors and its effects on cAMP production

The expression of adrenomedullin (ADM) and its mRNA was studied in human glial cell tumors and cultured glioblastoma cell lines, T98G and A172. Northern blot analysis showed that ADM mRNA was expressed in all brain tumors examined (three anaplastic astrocytomas and two glioblastomas multiforme) and in the glioblastoma cell lines. Immunoreactive (IR-) ADM was detectable in these brain tumors by radioimmunoassay (0.31-2.0 pmol/g wet weight), except for one anaplastic astrocytoma. Reverse phase high performance liquid chromatography of the tumor extracts showed a single peak eluting in the position of ADM-(1-52). IR-ADM concentrations in the cultured media of T98G cells were 205.5 +/- 8.4 fmol/10(5) cells/24 h (mean +/- SEM, n = 5). Treatment of T98G cells with interferon gamma or interleukin 1 beta increased the expression levels of ADM mRNA and the IR-ADM concentrations in the cultured media, whereas tumor necrosis factor alpha decreased them in a dose-dependent manner. Treatment with synthetic ADM-(1-52) (10(-8) or 10(-7) mol/l) increased the cAMP concentrations in the cultured media of T98G cells. These findings suggest that ADM is secreted from glial cell tumors and is related to the pathophysiology of these tumors.     

An assessment of the anatomical relationship between the pelvic plexus and the rectal wall to determine the indications for its preservation in surgery for rectal cancer

Preservation of the pelvic plexus in surgery for rectal cancer could shorten the distance between the cancer and the lateral resection margin, whereby the curability of the operation may be reduced. To clarify the indications for preserving the pelvic plexus in such surgery, the relationship of the pelvic plexus to the rectum and rectal cancer was investigated anatomically in 12 autopsied specimens and 12 surgical specimens. The rectum and anus were dissected with all the pelvic organs from autopsied cadavers and transverse sections were prepared at 10-mm intervals after fixation. The location of the pelvic plexus was then measured on the tissue preparations, and compared to that of surgical specimens from rectal cancers with concurrent resection of the pelvic plexus. The pelvic plexus was located from 3.3 +/- 1.2 cm above to 2.3 +/- 1.9 cm below the peritoneal reflection in the autopsied specimens. The average distances between the muscularis propria and the pelvic plexus in the autopsied specimens and surgical specimens were 8.3 +/- 3.5 mm and 14.7 +/- 4.5 mm, respectively, showing a significant difference (P < 0.05). Pelvic plexuses were located about 10 mm from the outer margin of rectal muscularis propria. These findings indicate that concurrent resection of the pelvic plexus may be required to secure sufficient surgical clearance in pT3 rectal cancers, especially those invading deeply beyond the muscularis propria (a2).     

Solid-state reaction kinetics of the system CaO-FeO

The solid-state reaction mechanisms of the CaO-FeO system have been studied by a diffusion couple method in the temperature range of 1073 to 1273 K, under controlled oxygen-partial pressures. The interdiffusivities and intrinsic diffusivities of Ca²⁺ and Fe²⁺ have been determined in the limited FeO solid-solution range. Based on the obtained results, a solid-state reaction model of the system has been developed, taking account of the formation of the Ca₂Fe₂O₅ phase. According to the model, the diffusivities of Fe³⁻ in the Ca₂Fe₂O₅ phase have been estimated at 1273 K.     

Selective transalkylation of naphthalene and ethylnaphthalene over solid acid catalysts

A high 2,6-diethylnaphthalene (2,6-DEN) isomer ratio (62%) and a good 2,6-DEN yield (46 mol%) were obtained by the transethylation of 2-ethylnaphthalene with tetraethylbenzenes over H-Y zeolite catalyst. Steric hindrance and electron density at the substitution sites of naphthalene are two influential factors for excellent selectivity. Silica-alumina catalyst, which cannot be expected to possess shape selectivity, also demonstrated a high 2,6-DEN selectivity.     

Homologous complement activation on drug-induced apoptotic cells from a human lung adenocarcinoma cell line

Activation of the alternative pathway of homologous complement (C) was observed in a human lung adenocarcinoma cell line, CADO 43, after the cells had become apoptotic following treatment in vitro with vincristine and predonisolone. Deposition of C3b and C3bi on the serum-treated apoptotic cells was revealed by flow cytometry with anti-C3b and -C3bi-specific antibodies and immunoblotting with anti-C3 antibody immunoprecipitates extracted from solubilized fractions of serum-treated apoptotic cells. Two molecular mechanisms were found to be responsible for this post-apoptotic C-activation. Firstly, all C regulators, decay accelerating factor (DAF), membrane cofactor protein (MCP) and C3b/C4b receptor (CR1), were diminished on the cell surface concomitantly with the apoptotic process. Secondly, unidentified molecules which potentially activate homologous C and accept C3b/C3bi fragments became expressed on the cell surface during the apoptotic process. These findings may explain the mechanism whereby tumor cells are efficiently eliminated through chemotherapy.