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Objectives Plasmalogen, phospholipids with previously shown associations with dementia, has attracted attention as a substance found in some studies to improve cognitive function. The effects of ascidian-derived plasmalogens on cognitive performance improvement were assessed in a randomized, double-blind, placebo-controlled study including Japanese adult volunteers with mild forgetfulness. Methods Participants consumed either the active food containing ascidian-derived plasmalogen (1 mg as plasmalogen) or the placebo food for 12 weeks, and their cognitive performance was assessed by Cognitrax. Participants were randomly allocated into the intervention (ascidian-derived plasmalogen; 8 males, and 17 females; 45.6 ± 11.1 years) or the placebo (9 males, and 15 females; mean age, 46.4 ± 10.8 years) group. Results Compared to the placebo group, the intervention group showed a significant increase score in composite memory (eight weeks: 3.0 ± 16.3 points, 12 weeks: 6.7 ± 17.5 points), which was defined as the sum of verbal and visual memory scores. Conclusions These results indicate the consumption of ascidian-derived plasmalogen maintains and enhances memory function. This study was registered at the University Hospital Medical Information Network Clinical Trial Registry (UMIN-CTR, registry no. UMIN000026297). This study did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

We found a good linear relation between the mean volume backscattering strength measured using a scientific echo sounder and the distribution density of moon jellyfish recorded simultaneously by an underwater video camera in small bays (Hokezu Bay and Mikame Bay) in Japan. This relation held in all of the surveys carried out in recent years (2013–2016), although the regression coefficient varied slightly from year to year due to the existence of ambient organisms. Using this relation and high-resolution echo sounder scan surveys across the bay, we obtained the spatial structures of moon jellyfish aggregations and categorized them into either patchy, layered, or wavy aggregations. We also examined possible physical mechanisms responsible for the moon jellyfish aggregations. In particular, passive particle tracking simulations of several idealized internal wave fields suggest that the formation of wavy aggregations is closely related to the presence of internal waves. However, internal waves alone cannot induce patchy and layered aggregations, indicating that particular biological processes (e.g., swimming behavior) are also necessary for such aggregations to form.

We have to develop an integrated numerical model to support policymaking for coastal environment development and conservation. In this context, integration means the integration of land, coastal sea, open sea, sea bottom, and air, and the integration of the results from studies of natural, social, and human sciences.

A thermophone is a thermoacoustic transducer, which generates sound via time-varying Joule heating of an electrically conductive layer, which leads to expansion and contraction of a small pocket of air near the surface of the film. In this work, a 10-μm-thick Ag–Pd conductive film was coupled with heat-insulating and heat-releasing layers to fabricate a three-layer thermophone for generating ultrasound. The heat-insulating layer was 47 μm thick, and was made of glass. The heat-releasing layer was 594 μm thick, and was made of 94% alumina. Because of the simple sound-generation mechanism, which does not require mechanical moving parts, the Ag–Pd conductive film on the glass substrate can produce ultrasound radiation with broadband frequency characteristics, where exiting commercial electrode materials were used. We also demonstrate that the measured directivity patterns are in good agreement with theoretical predictions, assuming a rectangular diaphragm with the same size as the metallic film.

Solubility has a crucial role in the success of a drug candidate. Compounds with low solubility not only cause problems for in vitro and in vivo assays, but also add significant burdens to drug development. Drug discovery and drug development often have different solubility screening requirements and methodologies have been developed to meet the needs of these different stages.

イチジク（Ficus carica L.‘桝井ドーフィン’）のいや地と低温障害からの早期回復を目的として，株間4.0 m（慣行）より密植の株間0.8および2.0 mに栽植した樹の生育，収量，果実品質について，5年間調査した．その結果，特に株間0.8 mの密植は，果実品質を保ちながら樹勢と収量の維持が図られ，株間2.0 mと4.0 mに比べて，連作地の樹勢低下対策として有効であることが示唆された．イチジク樹が低温障害を受けた場合，著しい収量の低下が認められたが，0.8 m区では収量の減少が小幅であるのに対し，栽植密度が低いほど収量の減少は大きかった．さらに，樹勢，果実品質および収量は0.8 m区で最も早く回復し，低温障害発生後2年目には元の水準に回復できることが示された．これらの結果から，0.8 mの密植は，いや地と低温障害からの早期回復に有効であることが明らかとなった．

イチジク‘桝井ドーフィン’に対する環状剥皮が凍害の発生に及ぼす影響を検討した．露地圃場の挿し木個体は萌芽期の凍害を受けたが，前年の秋季に環状剥皮処理を行った挿し穂を用いると，萌芽が遅くなり凍害が軽減された．また，ポットの挿し木個体について，萌芽期に低温処理を行った結果，−3℃以下で枯死する芽が発生した．しかし，前年の秋季に環状剥皮を施し，かつ，より下位節から採取した挿し穂の方が糖やデンプン含量が高く，遅く萌芽して芽の枯死が少なかった．さらに，露地圃場に定植した幼木についても，秋季に環状剥皮を行った枝の糖とデンプン含量が高く，厳寒期の凍害が少なかった．以上より，イチジク‘桝井ドーフィン’に対する環状剥皮処理は，休眠枝の貯蔵養分を高め，その生育ステージが遅延することによって，萌芽期や厳寒期の凍害を軽減する効果があると考えられた．

新薬の物性測定，結晶スクリーニング，製剤技術の応用といった薬剤学的検討は，吸収性・薬物動態・製造性・安定性に大きな影響を与える．創薬研究を効率よく行うには，探索段階のステージに応じた，脂溶性・酸塩基解離定数・溶解度・溶解速度測定などの分子物性測定，結晶化・塩・結晶多形のスクリーニング，製剤技術の応用といった項目を実施することが重要である．また，それぞれの項目について科学的理解と最新の技術（テクノロジー）の把握，さらに創薬研究への応用についての正しい戦術策定があってこそ，新規スクリーニングの開発と導入，適切なプロジェクトへの応用といった意味のある研究が可能になる．それらを可能にするには科学技術・プロジェクトチーム両面から見た人材育成も必要であり，そのためにはマネージメントも大きな役割を果たす．探索段階における薬剤学的研究の意義とファイザー株式会社中央研究所（愛知県）における実践例を紹介する．

(−)-6-{2-[4-(3-Fluorophenyl)-4-hydroxy-piperidin-1-yl]-1-hydroxyethyl}-3,4-dihydro-quinolin-2(1H)-one (compound A) is an NR2B selective N -methyl d -aspartate (NMDA) antagonist that has shown at least two polymorphs, forms I and II. In this report, we prepared two polymorphs, forms I and II and their crystal forms were identified and characterized by single crystal X-ray diffractometry, differential scanning calorimetry (DSC) and variable temperature powder X-ray diffractometry (VT-PXRD). The results of DSC and VT-PXRD suggested that compound A has at least three polymorphic forms: I, II and a new form III, and that forms II and III showed an enantiotropic relationship. We also performed single crystal X-ray analyses of specific conditions based on the results of VT-PXRD. The unit cell dimensions in crystallographic parameter and molecular arrangements of form I were quite different from forms II and III. Whereas, the crystal structures of forms II and III were similar with the exception of the C58–C59–C61–C62 torsion angle.

The purpose of the present study was to construct the theoretical dissolution model of poly-disperse drug particles in biorelevant media containing bile salt/lecithin aggregates (micelles or vesicles). The effective diffusion coefficient in the biorelevant medium and the particle size distribution of drug particles were simultaneously factored into the Nernst-Brunner equation. The effective diffusion coefficient of a drug in the biorelevant medium was calculated to be smaller than that in the blank buffer, since the diffusion coefficient of a drug bound to the aggregates became similar to that of the aggregates. The particle size distribution of a drug powder was simulated as the sum of mono-disperse fractions covering the particle size range. To verify the modified equation, the dissolution profile of griseofulvin and danazol in a taurocholic acid/egg lecithin (4:1 mixture, taurocholic acid-=-0-30 mM) system was investigated. It was clearly demonstrated that both modifications on the Nernst-Brunner equation improved the prediction accuracy. When the effect of the particle size distribution was neglected, the theoretical curve underestimated the observed value at the early phase of dissolution process. When the diffusion coefficient of a free drug was used instead of the effective diffusion coefficient, the theoretical curve overestimated the observed value. The results of the present study suggested that the effect of the particle size distribution and the effective diffusion coefficient should be taken into consideration.

As a high throughput solubility assay, the solution-precipitation method using a dimethylsulfoxide (DMSO) sample stock solution (DMSO-SP) has been widely used in drug discovery. However, the solid form of the precipitant has not been investigated. In this study, we investigated the experimental conditions of the DMSO-SP, focusing on the solid form of the precipitant. The final concentration of DMSO was 1% (v/v). The precipitant of more than a half of the model compounds was observed as crystalline by polarized light microscopy analysis. When the incubation time was 20 h and the precipitant was crystalline, the DMSO-SP solubility was similar to the solubility from a powder material (PWD). However, when the incubation time was 10 min and/or the precipitant was not crystalline, the DMSO-SP solubility was higher than the PWD solubility. These results suggested that the information regarding the solid form of the precipitant is important in interpreting the solubility data. In addition, we developed an automated birefringence diagnose system for drug discovery usage.

The purpose of this study was to establish a useful methodology, possibly providing information on the stoichiometry of pharmaceutical drug salts obtained from salt screening by using a multiwell plate and a Raman microscope. Tamoxifen salt screening was conducted with monobasic and polybasic acids on 96-well quartz plates with a Raman microscope. Appearance and crystalline forms of salts prepared on 96-well plates were observed by polarizing light microscope and Raman microscope, respectively. Based on the results of the salt screening, tamoxifen citrate and fumarate salts were prepared on a large scale. The salts prepared were characterized by powder X-ray diffractometry (PXRD) and ion chromatography. The results of the multiwell salt screening indicated that tamoxifen has a tendency toward the formation of mono salt as opposed to hemi salt with polybasic acid, and that most of tamoxifen salts gave several potential polymorphic forms. PXRD patterns of scaled-up tamoxifen citrate and fumarate salts suggested that the same crystalline form was obtained from the binary mixture regardless of molar ratios of 2:1 or 1:1 (tamoxifen/acid). The crystalline forms obtained were tamoxifen monocitrate and monofumarate salts as measured by ion chromatography. Salt screening on multiwell plates with a Raman microscope provided novel insight into the characteristics prediction of the stoichiometrical salts in addition to potential polymorph information. Based on the stoichiometrical information of salts, the amount of compound and time required for crystalline form selection of drug candidates would be significantly reduced.

Structural modification of imidazole 5-lipoxygenase (5-LO) inhibitors for optimizing inhibitory potency, pharmacokinetic behavior and toxicity (ocular) profile led to 4-{3-[4-(2-methyl-1H-imidazol-1-yl)phenylthio]}phenyl-3,4,5,6-tetrahydro-2H-pyran-4-carboxamide (6) with no observable ocular toxicity. The orally active and safe imidazole 5-LO inhibitor 6 was selected as a clinical candidate and advanced to clinical studies. An improved synthesis of 6 is also discussed.

An efficient synthesis of 1, a novel orally active 5-lipoxygenase inhibitor, was developed. Key features of the modified synthetic route include facile construction of the benzyl phenyl ether moiety by nucleophilic aromatic substitution and THP ring by cyclization, and base-promoted hydrolysis of the nitrile group to carboxamide. The improved three-step synthesis provides 25 g of 1 for pre-clinical toxicology studies in a total yield of 59%.

In order to successfully apply drug delivery systems (DDS) to new chemical entities (NCEs), collaboration between medicinal chemists and formulation scientists is critical for efficient drug discovery. Formulation scientists have to use 'language' that medicinal chemists understand to help promote mutual understanding, and medicinal chemists and formulation scientists have to set up strategies to use suitable DDS technologies at the discovery phase of the programmes to ensure successful transfer into the development phase. In this review, strategies of solubilisation formulation for oral delivery, inhalation delivery, nasal delivery and bioconjugation are all discussed. For example, for oral drug delivery, multiple initiatives can be proposed to improve the process to select an optimal delivery option for an NCE. From a technical perspective, formulation scientists have to explain the scope and limitations of formulations as some DDS technologies might be applicable only to limited chemical spaces. Other limitations could be the administered dose and, cost, time and resources for formulation development and manufacturing. Since DDS selection is best placed as part of lead-optimisation, formulation scientists need to be involved in discovery projects at lead selection and optimisation stages. The key to success in their collaboration is to facilitate communication between these two areas of expertise at both a strategic and scientific level. Also, it would be beneficial for medicinal chemists and formulation scientists to set common goals to improve the process of collaboration and build long term partnerships to improve DDS.

Secretory capacities including folding and assembly are believed to be limiting factors in the establishment of mammalian cell lines producing high levels of recombinant therapeutic proteins. To achieve industrial success, it is also important to improve protein folding, assembly, and secretory processes in combination with increasing transcription and translation. Here, we identified the expression of CHOP/Gadd153 and GRP78, which are unfolded protein response (UPR)-related genes, correlated with recombinant antibody production in stable CHO cells. Subsequently, CHOP overexpression resulted in increasing recombinant antibody production in some mammalian cell lines, and in addition a threefold further enhancement was obtained by combining expression with UPR-related genes or ER chaperones in transient assays. Overexpression of CHOP had no effect on the biochemical characteristics of the product. These results suggest overexpression of CHOP and its combinations may be an effective method to efficiently select a single cell line with a high level of antibody production in the development of cell lines for manufacturing.

The mutation of serine-174 to phenylalanine that causes a defect in the Escherichia coli F 1 -ATPase β-subunit is suppressed by further mutations; Gly-149 to Ser, Ala-295 to Thr, Ala-295 to Pro, or Leu-400 to Gln (Miki, J., Fujiwara, K., Tsuda, M., Tsuchiya, T. and Kanazawa, H. (1990) J. Biol. Chem. 265, 21567–21572). We analyzed the effects of these second site mutations and of a newly identified Asn-158 to Tyr mutation on the activities of the ATPase without the original Ser-174 to Phe mutation. The β-subunit with each amino acid replacement was expressed in the mutant strain JP17, which does not have a β-subunit. Cells transformed with the plasmid carrying Ala-295 to Pro mutation alone did not grow on minimal medium agar supplemented with succinate as the sole carbon source, and showed 3% of the wild-type ATPase activity, suggesting that this mutation caused structural alterations affecting the catalytic function of the enzyme. Conversely transformants with other mutations grew well and had higher ATPase activities, suggesting that these mutations did not cause extensive structural alterations. From the transformants with the plasmid carrying the Ala-295 to Pro mutation, seven revertants capable of cell growth on succinate plates were isolated and reversion mutations were identified at residues 140, 159, 166, 171, 172 and 184 of the β-subunits. The results suggested that Ser-174 and Ala-295 do not necessarily interact directly, but that the regions including these suppression mutation sites close to Ser-174, and Ala-295 interact with each other for the proper functioning of the ATPase. The ternary structure of the region surrounded by the residues which were identified as the reversion mutation sites for Ser-174 to Phe and Ala-295 to Pro mutations is important for the catalytic function of this enzyme.

A new set of 142 experimentally determined complexation constants between sulfobutylether-β-cyclodextrin and diverse organic guest molecules, and 78 observations reported in literature, were used for the development of the QSPR models by the two machine learning regression methods – Cubist and Random Forest. Similar models were built for β-cyclodextrin using the 233-compound dataset available in the literature. These results demonstrate that the machine learning regression methods can successfully describe the complex formation between organic molecules and β-cyclodextrin or sulfobutylether-β-cyclodextrin. In particular, the root mean square errors for the test sets predictions by the best models are low, 1.9 and 2.7 kJ/mol, respectively. The developed QSPR models can be used to predict the solubilizing effect of cyclodextrins and to help prioritizing experimental work in drug discovery.

Mouse-mouse hybridoma cells were immobilized in polyacrylate-alginate gels. The immobilized hybridoma cells were cultured semi-continuously using a fluidized bed reactor, and allowed continuous antibody production without any gel destruction for one month. It has been proved that the polyacrylate-alginate gels were tolerant against physical stress. The composition of the gels suitable for cell growth and antibody production was given as follows; viscosity of alginate at 1% solution: 60–100 cP, alginate concentration: 0.8%, and polyacrylate concentration: 0.2%. In the semi-continuous culture using gels prepared under suitable conditions, the viable cell number was estimated as 2.5×107 cells/ml-gel, and the antibody production rate was 2.2 mg/ml-gel/d, at maximum.

アルギン酸とポリウレタンを用いた動物細胞固定化ビーズにおいて, ウレタンプレポリマーへのゼラチン粉の添加はポリウレタン層に発泡を起こし細胞増殖や抗体生産を促進した.ゼラチン粉の添加濃度を検討したところ, グルコース消費あたりの抗体生産収率とゲル容積あたりの抗体生産速度はともにゼラチン粉添加濃度0.1%～0.2%で最大値を示した.これらの固定化ビーズを用いカラム灌流培養を行ったところ, フラスコ培養と比べて, 約1.5倍の抗体生産収率を与えた.さらに, カラム灌流培養での抗体生産速度は, フラスコ回分培養に比べて約9倍に上昇し, 約300μg/cm3-bead/dayに達した.培養終了後の生細胞数は約1×107cell/cm3-beadであった.この固定化ビーズは50日間の連続培養においても, 崩壊せず連続した抗エリスロポエチン抗体の生産を可能とした.また, 固定化ビーズからの細胞の漏れは, リアクター全体の生細胞数の約2%に過ぎなかった.

アルギン酸とポリウレタンを用いた動物細胞固定化ビーズの連続作製法に関する検討を行った.装置はアルギン酸をゲル化させる部分と, それに続く二重管とからなる.アルギン酸細胞懸濁液は装置内で塩化カルシウム中に滴下されゲル化する.形成されたゲルはゆっくりと内管の端まで沈降し外管から供給されるウレタンプレポリマーにより被覆される.アルギン酸細胞懸濁液へのアルミナの添加は固定化ビーズの連続作製を容易にした.さらにアルミナはゲルマトリックスの構造を抗エリスロポエチン抗体を分泌するマウスハイブリドーマの増殖に適したものに変化させた.細胞増殖は固定化に用いるウレタンプレポリマーの特性に依った.反応基であるイソシアネート含量が低いほど, 固定化による細胞の死滅は少なかった.また, エチレンオキサイド含量が高いプレポリマー (91%) では, その含量が低いプレポリマー (57%) に比べて, より良好な細胞増殖と抗体生産が観察された.

The purposes of the review are to: a) Provide a comprehensible introduction of the-state-of-the-art sciences of solubility and dissolution, b) introduce typical technologies to assess solubility and dissolution, and c) propose the best practice strategy. The theories of solubility and dissolution required in drug discovery were reviewed especially from the view point of oral absorption. The physiological conditions in the gastrointestinal fluid in humans and animals were then briefly summarized. Technologies to assess solubility and dissolution in drug discovery were then introduced. Recently, these technologies have been improved by the laboratory automation and computational technologies. Finally, the strategies to apply these technologies for a drug discovery project were discussed.

From discovery synthesis of a zwitterionic pharmaceutical compound, 4-{[4-({[(3-isopropyl-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl)carbonyl]amino}methyl)piperidin-1-yl]methyl}tetrahydro-2H-pyran-4-carboxylic acid (compound A), two anhydrous ZW-I and ZW-II and two hydrate forms ZW-III and ZW-IV were identified. Although stable form ZW-I was chemically stable at 70 °C/75% RH for 10 days, it was transformed to hydrate form ZW-IV under ambient conditions within a few days, taking up water from atmospheric moisture. In order to select a solid form for further investigation, solid-state characterization, salt screening on 96-well plate, stable polymorph and hydrate screening and physical stability were performed. Based on the results of the salt screening, besylate, camsylate, hemi-edisylate, hemifumarate, monosuccinate salts of compound A were prepared, and their polymorphism and chemical and physical stability were evaluated. From the viewpoint of stability and manufacturability, a stable form of besylate salt (BSA-I), which had two anhydrous forms BSA-I and BSA-II and hydrate form BSA-III, was selected as a solid form. BSA-I was quite stable at high relative humidity and provided significant improvement of physical stability compared with ZW-I.

An efficient synthesis of 1, a novel orally active 5-lipoxygenase inhibitor, was developed. Key features of the modified synthetic route include facile construction of the benzyl phenyl ether moiety by nucleophilic aromatic substitution and THP ring by cyclization, and base-promoted hydrolysis of the nitrile group to carboxamide. The improved three-step synthesis provides 25 g of 1 for pre-clinical toxicology studies in a total yield of 59%.

A convenient synthetic route to 4-[3-(4-heterocyclylphenylthio)phenyl]-3,4,5,6-tetrahydro-2H-pyran-4-carboxamide analogues as 5-LO inhibitors is described. This methodology enabled rapid development of structure-activity relationships (SARs) leading to improvement of pharmacological properties. Thus, new compounds with higher 5-LO inhibitory potency were discovered. The stereo-chemistry requirements of the tetrahydropyran ring are also discussed.

Described herein are structure-activity relationships (SARs) of 4-[5-fluoro-3- [4-(2-methyl-1H-imidazol-1-yl)benzyloxy]-phenyl]-4-methoxy-3,4,5,6-tetrahydro-2H-pyran (1, CJ-12,918), an imidazole 5-lipoxygenase (5-LO) inhibitor. When 1 was tested in preclinical studies, cataract formation was observed in rats; however, this compound was metabolized extensively in vivo and showed low systemic exposure. To eliminate this side effect and enhance bioavailability, structural modification was focused on replacing the methoxy group of 1 by modulating lipophilicity (i.e., predicted log D at pH 7.4). The SARs led to the discovery of 4-[5-fluoro-3-[4-(2-methyl-1H-imidazol-1-yl)benzyloxy]phenyl]-3,4,5,6-tetrahydro-2H-pyran-4-carboxamide (10, CJ-13,454), which was less lipophilic by 1.2 log D units and showed in vivo potency (ED 50 = 4-9 mg/kg) equipotent to 1. Enhanced metabolic stability resulted in fewer in vivo metabolites, as well as improved bioavailability and a better toxicological profile. Thus, 10 was found to be a more practical lead for an orally active 5-LO inhibitor.

A family registration data entry system with functions for automatic form layout analysis and character recognition was developed. The layout analysis module first detects characters and ruled lines by using information on the top and bottom boundaries of smeared black components. It then determines the layout and identifies each field in the layout by comparing predefined models with detected lines. Character strings in the fields are recognized and matched with a dictionary to check whether a sequence is plausible as a Japanese word or not. The text data are registered in a database after they have been examined by an operator and keywords have been extracted. This system was actually used for the initial entry of typed family registration forms in Tokyo's Toshima Ward, which contributed to establish the first computerized family registration system in Japan.

In animal cell culture, oxygen supply sometimes limits cell growth. Therefore, four oxygen supply methods (free surface aeration, porous Teflon tubing, perfluorocarbon addition and external aerator) were compared in terms of oxygen transfer rate for suspension culture of animal cells. Oxygen transfer rate with the free surface aeration was dependent on the vertical position of the impeller and the stirred Reynolds number for h/HL greater than 0.35, but no effect of the impeller position was observed for h/HL less than 0.35. The relationship between the Reynolds and Sherwood numbers could be expressed by simple correlations. These correlations could also be applied to oxygen transfer using porous Teflon tubing. When oxygen was supplied with perfluorocarbon saturated with air, the overall mass transfer coefficient KL was estimated to be about 9.0 X 10(-3) cm s-1, which was five-fold greater than that of the surface aeration. Maximum cell densities which would be supported by four methods were calculated from values of KLa for different sizes of fermentor assuming that oxygen supply would be the rate-limiting factor in animal cell culture.

A new epoxidation method utilizing α-siloxyalkyl peroxybenzoate and Cu(OCOCF3)2 is described. Regioselective epoxidation of all trans farnesol is accomplished by the intramolecular version of this method.

The effects of lactate and ammonium concentrations on the growth of HL-60 and RPMI 8226 human cells were kinetically evaluated in a suspension culture system. The specific growth rates of the cells were expressed as the following equation with the terms of the inhibitory effects owing to lactate, ammonium, and glucose. mu;=mu; m S {(K s +S)(1+ P 1 k 1 + P 2 k 2 )+ S 2 k 3 } On the basis of this equation, it was possible to stimulate the culture processes of the human cells.

A mathematical framework was developed for the assessment of batch, repeated-batch and repeated fed-batch extractive fermentations of acetone and butanol or ethanol. Several useful expressions were derived for determining the noninferior set defined in the two-objective function space, which is concerned with the productivity and the concentration of the metabolic products. The computer simulation based on the experimental data revealed the possibility of attaining a significant improvement for extractive fermentations as compared with conventional fermentations without extraction.

Continuous culture of RPMI 8226 human hematopoietic cells was performed. The viable cell number and glucose, lactate and ammonium concentrations became constant within 3–4 days at a constant dilution rate. The viable cell number decreased at low and high dilution rates. The growth and product yields slightly depended on the dilution rate, except for product yield for lactate based on cell number. Growth characteristics of these cells at various dilution rates could be expressed by equations considering the maintenance energy in growth yield. Maximum specific growth rate could be evaluated from the wash-out profile and the known inhibition constants.

Hybridoma cells producing anti-α-amylase monoclonal antibody were entrapped in calcium alginate and the gels were then coated with urethane polymer. The urethane coating improved gel strength and prevented cell leakage. This immobilization method enabled direct air bubbling in the serum-free medium and a very high cell concentration (3×107 cells/ml gel) was obtained. By using a fluidized-bed reactor, effective removal of the medium in addition to sufficient oxygen supply could be achieved without any special devices and a very high concentration of the monoclonal antibody was continuously obtained.