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Biomedical subjects

S Hosoi

Publications and source records attributed to S Hosoi.

87 records · Page 5Linked to original sources
PubMed1981

CYBEST-CDMS; automated cell dispersion and monolayer smearing device for CYBEST.

The design and operational procedures of the cell dispersion and monolayer smearing (CSMS) machine for the CYBEST automated cytoscreening and image analysis system are described. The CYBEST-CDMS consists of two units: an autosyringing device for cells dispersion and an autosmearing device basically consisting of a modified commercial centrifuge. The operations of both devices are carried out with the samples in specially constructed centrifuge chamber units. The autosyringing device sequentially processes pairs of samples held in a rotor with a capacity of 12 centrifuge chamber units. Cell dispersion is achieved by syringing the samples 20 times each through 23-gauge needles. The use of Saccomanno solution instead of Ringer's solution as the final suspension medium prior to autosmearing has resulted in improved preparations. The CYBEST-CSMS machine largely fulfills one of the major requirements for automated cytology: the provision of samples with a sufficient number of isolated cells and a minimum number of clumped and/or overlapping cells

Autoanalysis↗
PubMed1980

Control of membrane potential by external H+ concentration in Bacillus subtilis as determined by an ion-selective electrode.

The membrane potential of intact bacteria was monitored by measuring the tetraphenylphosphonium ion distribution across the membrane using poly--(vinyl chloride) matrix-type electrode selective to tetraphenylphosphonimum ion. It was found that the tetraphenylphosphonium ion was not countertransported against H+ movement. The membrane potential of Bacillus subtilis was estimated to be 80-120 mV inside-negative at external pH 7. The effect of the external pH on the membrane potential was studied. It varied from 30 to 40 mV/decade change in the external [H+] in the pH region of greater than 6.5, increasing pH making it more inside-negative. The addition of carbonyl cyanide m-chlorophenylhydrazone depolarized the membrane, and the membrane potential approached the H+ equilibrium potential. The addition of N,N'-dicyclohexylcarbodiimide did not abolish the pH dependence of the membrane potential. Increasing the external [K+] did not affect the pH dependence. CN- partially depolarized the membrane. A parallel conductance model for membrane potential could explain the results qualitatively.

Bacillus subtilis↗
PubMed1978

Effect of substitution of monovalent anions in external medium on the swimming pattern of Salmonella typhimurium.

The effect of replacement of ions in the extracellular medium on the swimming pattern of bacteria (Salmonella typhimurium) has been investigated. The replacement of chloride ion (Cl-) in the standard medium by methanesulfonate ion (MS-) or by propionate ion (Pr-) induced an increase in the tumbling frequency, or a decrease of the end-to-end distances of tracks. Replacement of MS- by Cl- resulted in transient depression of tumbling, and replacement of Pr- by Cl- resulted in immediate recovery of normal swimming. The replacement of cations was not very effective. The experimental data, including the dependence of the effect of replacement on the ion concentration, are consistent with the ideas that the tumbling frequency increases with depolarization of the bacterial membrane and that such anions as MS- and Pr- are more able to permeate the membrane than is Cl-.

Chlorides↗
PubMedDate not supplied

Stabile production of a thrombin resistant pro-urokinase derivative (PRO-UKS1) by Namalwa KJM-1 cells adapted to serum-free medium.

Pro-UKS1 was designed as a thrombin-resistant derivative of pro-urokinase (pro-UK) by introducing a glycosylation site using site-directed mutagenesis. An expression plasmid for pro-UKS1, pMo1UKS1SEd1-5, was constructed and introduced into Namalwa KJM-1 cells (Hosoi et al., 1988), and cells resistant to G418 and Methotrexate (MTX) were obtained. Amongst them, the highest pro-UKS1 producer (resistant to 500 nM of MTX), clone 41-8, was selected and further characterized. Clone 41-8 was cultured in serum-free ITPSGF medium (Hosoi et al., 1988). Under the conventional conditions, the concentration of pro-UKS1 reached 26 micrograms ml-1. Addition of glucose and tri-iodothyronine (T3) improved productivity, and the maximal productivity of pro-UKS1 was 67 micrograms ml-1 day-1. In this conditioned medium, content of pro-UKS1 was above 80% of total proteins.

Amino Acid Sequence↗
PubMedDate not supplied

Modulation of oligosaccharide structure of a pro-urokinase derivative (pro-UK delta GS1) by changing culture conditions of a lymphoblastoid cell line Namalwa KJM-1 adapted to serum-free medium.

Pro-UK delta GS1 was designed as a long-life and thrombin-resistant derivative of pro-urokinase (pro-UK) by deleting the growth factor domain of pro-UK and introducing a glycosylation site near the thrombin cleaving site for thrombin-resistance using site-directed mutagenesis. An expression plasmid for pro-UKDGS1, pIH1UK delta GS1SEd1-5 was constructed and introduced into Namalwa KJM-1, a lymphoblastoid cell line adapted to serum-free medium, and cells resistant to G418 and Methotrexate (MTX) were obtained. Amongst them, the highest pro-UK delta GS1 producer (resistant to 200 nM of MTX), clone 2-9, was selected and used for further studies. Under the conventional conditions, i.e. at 37 degrees C in serum-free ITPSGF medium (based on RPMI-1640 medium), the oligosaccharide structure of pro-UK delta GS1 produced by clone 2-9 mainly consisted of fucose (Fuc)-containing biantennary complex-type oligosaccharide. Addition of dexamethasone (Dex), changed the carbohydrate contents in the media, and a shift down of incubation temperature caused a change in oligosaccharide structure of pro-UK delta GS1 from mainly Fuc-containing biantennary to mainly Fuc-containing tri- and tetraantennary complex-type oligosaccharide. The modulated pro-UK delta GS1 showed superior in vivo activity for a canine femoral thrombosis formed by inserting a copper-coil.

Amino Acid Sequence↗
PubMedDate not supplied

Change of retinal correspondence in monocularly reduced intensity of stimulus.

We analyzed the retinal correspondence with a phase difference haploscope on reducing the stimulus intensity of a monocular image with a series of neutral density filters. Ninety-one exotropes were examined by this method. Five cases changed from normal to anomalous correspondence when the stimulation of the strabismic eye was reduced. Two cases showed anomalous correspondence without a filter, but normal correspondence with a reduced stimulus of the normal eye. All these seven cases showed normal correspondence with any other test. The results suggest that masked anomalous correspondence becomes manifest in some cases when the strabismic eye is stimulated more intensely than the normal eye. These cases display both normal and anomalous correspondence and this condition may be called dual correspondence.

Adolescent↗