Preliminary time-flow study: comparison of interpretation times between PACS workstations and films

Toshiba Hospital installed a PACS and RIS in the diagnostic imaging department along with a hospital-wide HIS in May 1993. Our PACS includes three diagnostic workstations each of which is provided with six monochrome CRT monitors. The diagnostic workstations have been used as the primary tools for interpretation of almost all radiographic images. The actual image interpretation time was measured for diagnostic workstations (237 examinations) and for conventional hard-copy films (219 examinations) for CR, CT, and MRI. The difference in interpretation times between diagnostic workstations and films was not significant. With regard to image interpretation time, diagnostic workstations are thought to be acceptable for practical image reading.

Production of the chimeric-binding protein, maltose-binding protein-protein A, by gene fusion

A fusion protein between maltose-binding protein (MBP) and staphylococcal protein A (SpA) was genetically produced. The gene fusion plasmid, pMALPA2, was constructed by inserting the protein A gene into an expression vector of maltose-binding protein in frame, and was expressed efficiently in Escherichia coli. The resulting fusion protein of molecular mass 65 kDa, retained the activity of both MBP and SpA (binding capability to amylose and immunoglobulin G). This chimeric-binding protein was used as an adhesive molecule for immobilization of antibodies to a solid-phase surface for enzyme immunoassay. An enzyme immunoassay was performed with the fusion protein, and human IgG was determined in the concentration range from 10(-4) to 10(-6) g ml-1.

Biosensing of benzene derivatives in the environment by luminescent Escherichia coli

Sensitive and convenient biosensing of environmental pollutants has been developed by fusing a gene of firefly luciferase to the TOL plasmid. TOL plasmid of Pseudomonas putida encodes a series of enzymes for degradation of benzene and its derivatives. The expression of these enzymes is controlled with the regulating proteins xylR and xylS, whose promoters are activated in the presence of aromatic compounds. The structural gene of firefly luciferase, as a reporter enzyme, was inserted under the control of the promoter of xylS protein, and gene fusion plasmid pTSN316 was constructed. The recombinant Escherichia coli transformed with this plasmid was applied to the environmental biosensing of benzene derivatives. The expression of luciferase was induced in the presence of aromatic compounds and the lower detection limit for m-xylene was 5 microM.

Multilabeling of ferrocenes to a glucose oxidase-digoxin conjugate for the development of a homogeneous electroenzymatic immunoassay

A new homogeneous electroenzymatic immunoassay was developed to determine antibody concentration using glucose oxidase and ferrocene as enzymatic and electrochemical amplifier, respectively. Digoxin (Dig)-conjugated glucose oxidase (GOx) was modified with ferrocene (Fec) to form Fec-GOx-Dig conjugate. After immunocomplex formation between the Fec-GOx-Dig conjugate and the anti-digoxin antibody, the complex underwent less electrochemical reaction due to the steric hindrance of the antibody. The ferrocene multilabeled conjugate was provided for the determination of anti-digoxin antibody. Since the strategy taken here is based on a combined effect of GOx and ferrocene, i.e., enzymatic amplification by GOx and electrochemical amplification by multilabeled ferrocenes, the antibody concentration was determined in the range from 1/50 to 1/500 dilution.

Molecular characterization of a mouse prostaglandin D receptor and functional expression of the cloned gene

Prostanoid receptors belong to the family of G protein-coupled receptors with seven transmembrane domains. By taking advantage of nucleotide sequence homology among the prostanoid receptors, we have isolated and identified a cDNA fragment and its gene encoding a mouse prostaglandin (PG) D receptor by reverse transcription polymerase chain reaction and gene cloning. This gene codes for a polypeptide of 357 amino acids, with a calculated molecular weight of 40,012. The deduced amino acid sequence has a high degree of similarity with the mouse PGI receptor and the EP2 subtype of the PGE receptor, which together form a subgroup of the prostanoid receptors. Chinese hamster ovary cells stably expressing the gene showed a single class of binding sites for [#H]PGD2 with a Kd of 40 nM. This binding was displaced by unlabeled ligands in the following order: PGD2 > BW 245C (a PGD agonist) > BW A868C (a PGD antagonist) > STA2 (a thromboxane A2 agonist). PGE2, PGF2 alpha, and iloprost showed little displacement activity at concentrations up to 10 microM. PGD2 and BW 245C also increased cAMP levels in Chinese hamster ovary cells expressing the receptor, in a concentration-dependent manner. BW A868C showed a partial agonist activity in the cAMP assay. Northern blotting analysis with mouse poly(A)+ RNA identified a major mRNA species of 3.5 kb that was most abundantly expressed in the ileum, followed by lung, stomach, and uterus.

CAG expansions in a novel gene for Machado-Joseph disease at chromosome 14q32.1

We have identified a novel gene containing CAG repeats and mapped it to chromosome 14q32.1, the genetic locus for Machado-Joseph disease (MJD). In normal individuals the gene contains between 13 and 36 CAG repeats, whereas most of the clinically diagnosed patients and all of the affected members of a family with the clinical and pathological diagnosis of MJD show expansion of the repeat-number (from 68-79). Southern blot analyses and genomic cloning demonstrates the existence of related genes. These results raise the possibility that similar abnormalities in related genes may give rise to diseases similar to MJD.

Determination of synthetic food dyes by capillary electrophoresis

A method for the determination of synthetic tar dyes used as food additives using capillary electrophoresis with photodiode-array detection was investigated. The dyes Erythrosine (R-3), Phloxine (R-104), Rose Bengal (R-105), Acid Red (R-106), Amaranth (R-2), New Coccine (R-102) and Allura Red AC (R-40) were separated on a capillary column (50 cm x 75 microns I.D.) and identified from the absorbance spectra of each peak. The electrophoresis buffer used was a mixture of 25 mM sodium phosphate buffer and 25 mM sodium borate buffer (1:1) (pH 8.0) containing 10 mM sodium dodecyl sulfate (SDS). Substitution of beta-cyclodextrin for SDS in the electrolyte buffer was effective for the separation of R-2 and R-102. This modified method could be employed as an additional assay method for these two dyes.

[Three cases of neurogenic bladder due to neuro-Beçhet disease]

We reported three cases of neurogenic bladder due to neuro-Beçhet disease. Case 1 (24-year-old male) and case 3 (54-year-old male) had complaint of urinary frequency and urinary incontinence. Case 2 (35-year-old male) had a complaint of urinary retention. Uro-dynamic study were performed repeatedly in each case. Two cases showed overative detrusor activity in storage phase and normal or hypo detrusor activity in voiding phase. One case (case 2) showed normal detrusor activity in storage phase and acontractile in voiding phase. All cases showed detrusor-sphincter dyssynergia (DSD). All cases were managed with clean intermittent catheterization. Six months later case 2 complained of urge incontinence. Repeated uro-dynamic study revealed that bladder function changed from normal detrusor to overactive detrusor in storage phase. These findings suggest that neurogenic bladder due to neuro-Beçhet disease is characterized uro-dynamical by overactive detrusor in storage phase and DSD in voiding phase.

Conductive property of the zone of slow conduction of reentrant ventricular tachycardia and its relation to pacing induced terminability

In order to assess the functional characteristics of the zone of slow conduction of reentrant VT, rapid pacing was performed to entrain VT. The orthodromic conduction time was measured as the interval between the stimulus and the orthodromically captured electrogram recorded distal to the zone of slow conduction, but not precisely at the exit point, and its response to rapid pacing was evaluated. In 32 of 33 consecutive patients, rapid pacing was performed to entrain VT. Of these, rapid pacing was repeated in 28 patients at 3-10 cycle lengths in steps of 10 msec before VT was terminated, or rapid pacing produced an acceleration of the rate. A pacing induced prolongation of the orthodromic conduction time (slowed conduction) was observed in 16 (57.1%) patients and in another 12 (42.9%) patients, the conduction time was constant. The pacing induced termination was observed in 93.8% of VT with slowed conduction and in 50% of VT with constant conduction, and the difference was significant (P < 0.05). There was no difference in the cycle length of VT or the shortest paced cycle length between VT with and without slowed conduction. The zone of slow conduction in human VT showed different conductive properties and VT with slowed conduction was associated with an easier and safer terminability with rapid pacing. The fact might be useful in selecting patients for antitachycardia pacing.

Electronically modulated biological functions of molecular interfaced enzymes and living cells

Conducting polymer molecular interfaces have been implemented to modulate biological functions of fructose dehydrogenase, pyruvate oxidase and Saccharomyces cerevisiae at the electrode surface by adjustment of electrode potential. The enzyme activity of the polypyrrole-interfaced fructose dehydrogenase was electronically modulated by means of electron transfer between the enzyme and the electrode surface. The enzyme activity of polypyrrole-interfaced pyruvate oxidase was modulated by an electronically driven change of substrate concentration. The gene expression in polypyrrole-interfaced Saccharomyces cerevisiae was electronically induced by a change in the phosphate concentration.

Stimulation of acid phosphatase induction in Saccharomyces cerevisiae by electrochemical modulation of effector concentration

A novel modulating method of the expression of Saccharomyces PHO 5 gene, responsible for acid phosphatase (APase), is proposed. The method is based on electrochemical modulation of an effector (inorganic phosphate) concentration, as the gene expression is initiated below a threshold concentration of phosphate and is terminated above the threshold value. By positioning the yeast in the close neighborhood of a conducting polymer, the authors show the effectiveness of the electrochemical approach toward PHO 5 induction. Based on the approach, phosphate concentration is easily modulated at the boundary concentration by taking advantage of anion doping-undoping at a conducting polymer and the resulting anion localization-delocalization in the polymer, as the local enrichment of phosphate in the polymer results in the lowering of phosphate in the vicinity of polypyrrole. External phosphate concentration is thus electrochemically modulated when the conducting polymer is positioned in the close neighborhood of the yeast cells; thereby the PHO gene is induced. Here an electrochemical approach for the APase expression as a strategy of selective induction of specific genetic information is described. (c) 1993 John Wiley & Sons, Inc.

Bioluminescent immunoassay with a protein A-luciferase fusion protein

Protein A and firefly luciferase were genetically fused and the resulting fusion protein was applied to a bioluminescent immunoassay. The gene fusion plasmid, pMALU2, was constructed by inserting the structural gene of luciferase into a protein A expression vector, and was expressed in Escherichia coli. The resulting fusion protein of molecular weight 91 kDa retained not only the enzymatic activity of luciferase but also the binding capability of protein A to the Fc region of immunoglobulin G (IgG). The bioluminescent immunoassay was performed with the fusion protein and human IgG was determined in the concentration range from 10(-3) to 10(-7) g/ml.

Ca(2+)-responsive extensible monolayer membrane of calmodulin-albumin conjugate

A Ca(2+)-responsive monolayer protein membrane was prepared by developing calmodulin and bovine serum albumin at the air-water interface and by conjugating them with a bifunctional agent. In the case of the BSA monolayer, complex formation with Mg2+ generated a larger change in surface pressure than that with Ca2+. On the other hand, a drastic change in surface pressure was observed for the conjugated thin membrane associated with Ca2+ than that associated with Mg2+. Due to a drastic change in the conformation of calmodulin, the conjugated protein film changes its morphology (STM image), depending on Ca2+ concentration: the extended structure in the presence of Ca2+ transforms to a shrinked structure in the absence of Ca2+. The largest surface pressure change was detected when calmodulin was mixed with an equimolar amount of bovine serum albumin.

Electrically controlled proliferation of human carcinoma cells cultured on the surface of an electrode

Human carcinoma cells, MKN45, were cultured on the surface of a metal-coated plastic plate electrode the potential of which was controlled. The proliferation rate and cell morphology were altered depending on the applied potential. Cell proliferation was halted in the potential range above 0.4 V vs. Ag/AgCl, although cells started to proliferate again when the applied potential was shifted from 0.4 V to 0.1 V vs. Ag/AgCl. Fluorescence probe studies indicated that the fluidity of plasma membrane decreased in association with halting of cell proliferation. These results suggest that electrical stimulation causes cells to temporarily halt proliferation, and that cell proliferation was reversibly controlled by electrode potential. The mechanism is interpreted in relation to the change of plasma membrane structure represented by membrane fluidity.

Hyperproduction of a bifunctional hybrid protein, metapyrocatechase-protein A, by gene fusion

A hybrid protein between metapyrocatechase and Staphylococcal protein A was produced by recombinant DNA techniques. A plasmid carrying the fusion gene that encodes the hybrid protein was constructed and expressed in E. coli. Over 70% of soluble proteins of the cell extracts was estimated to be the hybrid protein. This fusion protein is about 65,000. Both the IgG-binding activity of protein A and the metapyrocatechase activity were found in the hybrid protein. The optimum pH of metapyrocatechase in the fusion protein was at around 6.5 and Km was 1.3 X 10(-5) M. A simple immuno-enzymometric assay was developed for anti-BSA antibody using the fusion protein.

[A combined chemo-endocrine therapy with tegafur, adriamycin, methotrexate and tamoxifen for advanced renal cell carcinoma]

Six patients with advanced renal cell carcinoma was treated with a new chemo-endocrine regimen consisting of Tegafur, Adriamycin, Methotrexate and Tamoxifen. Estrogen receptor was measured in four cases from renal or metastatic tumors by DCC method, presenting 14.7, 9.7, 1.0 and 0 f moles/mg protein respectively. The patients were medicated with 800-1,200 mg of Tegafur and 20 mg of Tamoxifen daily po, and 20 mg of Adriamycin and 10 mg of Methotrexate intermittently for two weeks interval iv. According to a criteria of Japan Society for Cancer Therapy, two were regarded as CR, one as PR, one as NC and two as PD. The one out of two cases with and without estrogen receptor responded favourably to this therapy. Side effects observed in the treatment were mild gastrointestinal disorders including nausea and vomiting, slight degree of leukopenia, stomatitis, pigmentation and liver dysfunction. The patients were found to be in good quality of life during the treatment because of less toxicity. This therapy can be regarded as a good modality for a treatment of advanced renal cell carcinoma. This is a first report of combined chemo-endocrine therapy with Tegafur, Adriamycin, Methotrexate and Tamoxifen for renal cell carcinoma in the world.

Enzymatic synthesis of polyaniline film using a copper-containing oxidoreductase: bilirubin oxidase

Electroactive polyaniline films have been synthesized by using a copper-containing oxidoreductase, bilirubin oxidase (BOD). Enzymatic polymerization took place on the surface of BOD-adsorbed solid matrix which was in contact with a buffer solution containing aniline. Optimum conditions for enzymatic polymerization of aniline were investigated. Elemental analysis and IR spectroscopy indicated that the enzymatically synthesized film was polyaniline. The cyclic voltammetric studies demonstrated that the polyaniline film was electrochemically reversible in the redox properties in acidic aqueous solutions. Since the film retained enzymatic activity of BOD which was employed as a catalyst for polymerization, enzymatic polymerization seems promising in preparation of immobilized enzyme membranes.

Electrical effects on the proliferation of living HeLa cells cultured on optically transparent electrode surface

Low d.c. potential application induced changes of cellular morphology and growth of living cells on a potential-controlled electrode. At a potential range higher than +0.7 V (vs. Ag/AgCl), serious electric effects on cell viability, membrane permeability, and cytoskeletal morphology of HeLa cells were observed. On the other hand, at lower than +0.5 V no effect was observed. At the boundary potential range between +0.5 V to +0.7 V, where HeLa cells were cultured on the potential-controlled optically transparent In2O3 electrode (OTE) surface, intriguing effects on HeLa cells appeared. At this potential range, where HeLa cells cultured on a potential-applied OTE, all the cells were alive accompanying morphological change. The morphology of HeLa cells returned to their normal spindle shape, when potential application to the electrode was cut off. At a potential of +0.65 V, cell proliferation ratio of cultured cell on an electrode was about one-fifth of that on a non-controlled electrode. These results suggest that low d.c. electrical effects induce significant change in cellular morphology and function.