Stepwise ethanolysis of tuna oil using immobilized Candida antarctica lipase

Ethanolysis of fish oil under mild conditions has been strongly desired for preparing the starting materials for the purification of ethyl docosahexaenoate. Thus, we attempted ethanolysis of tuna oil using immobilized Candida antarctica lipase. The immobilized lipase was inactivated in the presence of 2 3 molar equivalent of ethanol against the total fatty acids in tuna oil. To avoid such inactivation, the first step of ethanolysis was conducted at 40 degrees C in a mixture of tuna oil and 1 3 molar equivalent of ethanol using 4% immobilized lipase. After a 10-h reaction, ethanol was consumed and 33% of tuna oil was converted to its corresponding ethyl esters (E-FAs). The reactant is named Gly/E-FA33. The lipase was not inactivated in the presence of 2 3 molar equivalent of ethanol against the total fatty acids in Gly/E-FA33. These findings and the consideration of several factors affecting ethanolysis of tuna oil led to the development of the two- and three-step ethanolyses. The two-step reaction was performed as follows: the first step was carried out at 40 degrees C for 12 h in a mixture of tuna oil and 1 3 molar equivalent of ethanol with 4% immobilized lipase; the second step was performed for 36 h (total reaction period, 48 h) after adding 2 3 molar equivalent of ethanol. On the other hand, the three-step reaction was conducted as follows: the first step was conducted under the same conditions as those in the two-step ethanolysis; in the second and third steps, 1 3 molar equivalent of ethanol was added after 12 and 24 h, respectively; and in the third step, the mixture was shaken for 24 h (total, 48 h). Both types of ethanolyses achieved the conversion of 95% or more of tuna oil to its corresponding E-FAs. To investigate the lipase stability, the two- and three-step ethanolyses were repeated by transferring the enzyme to a fresh substrate mixture of the first step after finishing one cycle of reaction. The two- and three-step reactions maintained over 95% of the conversion for 70 d and over 100 d, respectively.     

Impact of duration of caregiving on stress among primary caregivers of elderly

This study examined (1) the direct effect of the duration of caregiving on caregiver psychological distress, and (2) two- or three-way interactions between duration, stressors (elderly's physical and cognitive impairments), and personal (caregiver's economic or work status) or social (informal or formal supports) resources. We interviewed 833 primary family caregivers of non-institutionalized frail elderly who had been selected through a screening process of all residents aged 65 and over (21,567 persons) in a suburban area of Tokyo. Caregiver psychological distress was evaluated by "Caregiving Burden Scale" as a caregiving-specific psychological measurement, and "Center for Epidemiologic Studies Depression Scale (CES-D)" as a general psychological measurement. The results were as follows. 1. For Caregiving Burden, duration showed a direct effect, as those who had been providing care for a longer duration of time reported higher burden. We found no interactions between duration, stressors, and resources on caregiving burden. 2. For CES-D, duration had interactions, but no direct effect. (1) Two-way interactions were observed between duration and caregiver's economic or work status, as caregivers with a low economic status or who were unemployed showed a stronger negative impact from duration of caregiving. (2) Three-way interactions were observed between duration, the elderly's ADL impairment, and informal support. Informal support, such as a secondary caregiver, buffered the negative impact of the elderly's ADL impairment in cases with a shorter duration of caregiving, but not for those with longer duration. (3) Three-way interactions were observed between duration, the elderly's cognitive impairment, and formal emotional support. Formal emotional support buffered the negative impact of the elderly's cognitive impairment for those with a longer duration of caregiving, but not for those with a shorter duration. These findings suggest that stress-buffering resources differ according to duration of caregiving.     

Effects of mongoose odors on rat capture success

Wild rats,Rattus norvegicus, R. exulans, andR. rattus, avoided wire-cage live traps that had previously captured mongooses,Herpestes auropunctatus. Replacing traps soiled by mongooses with clean traps would increase rat capture success and reduce a source of experimental bias.     

Mathematical structures of line drawings of polyhedrons-toward man-machine communication by means of line drawings

Mathematical structures of line drawings of polyhedrons are studied and practical as well as theoretical solutions are obtained for several fundamental problems aroused in scene analysis and in man-machine communication. First, a necessary and sufficient condition for a line drawing to correctly represent a polyhedron is obtained in terms of linear algebra. Next, combinatorial structures are investigated and practical solutions are obtained to such problems as how to discriminate between correct and incorrect line drawings and how to correct vertex-position errors in incorrect line drawings. Lastly, distribution of the degree of freedom of a line drawing is elucidated and a method is proposed for interactive reconstruction of a polyhedron from a line drawing. The results obtained here enable us to make manmachine communication more ``flexible' in the sense that a machine can reconstruct three-dimensional objects from hand-drawn pictures even if the pictures are not perfect.     

Secondary structures of synthetic peptides corresponding to the first membrane-contact portion of normal band 3 and its deletion mutant (Southeast Asian ovalocytosis)

The heat shock response (HSR) was characterized in the gills of two lamprey species that differ with respect to their adult life history. In vivo labelling with [35S]methionine revealed an enhanced synthesis of heat shock proteins (HSPs) having approximate molecular weights of 70 kDa (HSP70) and 90 kDa (HSP90) following heat treatment. Induction of the HSR occurred in larval lampreys (ammocoetes) following temperature elevations of 13-16 degrees C for the parasitic species, the sea lamprey (Petromyzon marinus) and 16-20 degrees C for the nonparasitic species, the brook lamprey (Lampetra appendix). The case in L. appendix represents the greatest increase in temperature required to induce the HSR in gill tissue among aquatic poikilotherms studied to data and induction occurs within a temperature range (25-29 degrees C) not normally experienced by these animals. Western blotting detected the presence of 70 and 90 kDa HSPs and HSP70 levels were greater in post-metamorphic L. appendix than in ammocoetes both before and after heat shock. The HSR of lampreys appears to be induced during times of emergency when large, rapid temperature increases are experienced. The high set-point temperature for induction of the response may be a consequence of both the environments they presently inhabit and their experiences during evolution.     

Collagenous crystalloids in a fine needle aspirate of a pleomorphic adenoma of the minor salivary gland. A case report

BACKGROUND: Collagenous crystalloids were previously observed in histologic sections of pleomorphic adenoma. However, to the best of our knowledge, there have been no English-language reports dealing with collagenous crystalloids in fine needle aspirates. CASE: A fine needle aspiration specimen obtained from a mass in the hard palate of a 52-year-old female revealed collagenous crystalloids. The crystalloids were yellow to green, measured 30-50 microns in diameter and were radially arranged. CONCLUSION: This case indicates that collagenous crystalloids in salivary gland aspirates may be a clue to the diagnosis of pleomorphic adenoma.     

Size- and invasion-dependent increase in cyclooxygenase 2 levels in human colorectal carcinomas

Nonsteroidal anti-inflammatory drugs reduce the incidence and mortality of colorectal carcinoma. Their chemopreventive effects appear to be due to inhibition of cyclooxygenase (COX)-2. Here, we have studied the relationship between the COX-2 mRNA levels and pathological characteristics in 43 primary colorectal carcinomas. COX-2 levels were significantly higher in tumors with larger sizes and in those with deeper invasions but were not correlated with whether the patients had metastasis or not. These results suggest that larger carcinomas produce more COX-2 to support their own growth and that COX-2 inhibitors may be effective agents of carcinoma growth suppression.     

Functional and morphological damage of endothelium in rabbit ear artery following irradiation with cobalt60

1. The relaxant actions of acetylcholine and A23187 were examined in the rabbit central ear artery at different intervals following exposure to different doses of radiation with a cobalt60 unit. The artery was irradiated with a dose of 10 Gy, 20 Gy and 45 Gy. Radiation caused dose- and time-dependent impairment of the endothelium-dependent relaxations. The impaired endothelium-dependent relaxations occurred as early as 1 week postirradiation and persisted throughout the experimental period (10 weeks). 2. The endothelium-independent response to sodium nitroprusside was well preserved up to 6 weeks after irradiation. The contractile response to noradrenaline was unaltered by irradiation throughout the experimental period, but in contrast to control vessels, an increase in the sensitivity to noradrenaline in the presence of the nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine was not observed in the irradiated vessels. 3. The impaired endothelium-dependent relaxations in the irradiated vessels were not improved by pretreatment with the NOS substrate L-arginine, the cyclo-oxygenase inhibitor indomethacin or the free radical scavengers superoxide dismutase and catalase. 4. Scanning electron microscopy indicated morphologically intact endothelial cells within the first 4 weeks after irradiation. 5. Western blot analysis showed a significant decrease in the expression of endothelial NOS (eNOS) in the irradiated vessels. 6. These data indicate that endothelial cell function is specifically impaired in the irradiated vessels before morphological endothelial cell damage can be detected. This impairment may be related to diminished eNOS expression.     

High-performance bismuth-telluride compounds with highly stable thermoelectric figure of merit

The p-type (Bi_0.25Sb_0.75)₂Te₃ ingot doped with 8 wt% excess Te alone and the n-type Bi₂ (Te_0.94Se_0.06)₃ ingot codoped with 0.068 wt% I and 0.017 wt% Te were grown by the Bridgman method and annealed at 673 K for 5 h in a hydrogen stream. The electrical resistivity ρ, Seebeck coefficient α and thermal conductivity κ before and after annealing were measured at 298 K, so that the annealing degraded significantly ZT of the p-type specimen but enhanced remarkably that of the n-type one. The temperature dependences of ρ, α and κ of the as-grown p-type and annealed n-type specimens with higher ZT were investigated in the temperature range from 200 to 360 K. As a result, ZT values of the as-grown p-type and annealed n-type specimens have a broad peak and reached great values of 1.19 and 1.13 at approximately 320 K, respectively. The present materials were thus found to be far superior to any other bismuth-telluride compound in the thermal stability of energy conversion efficiency in addition to the high performance.     

Amino acid residues contributing to stabilization of Fusarium heterosporum lipase

Fusarium heterosporum lipase is composed of an N-terminal large peptide of 275 amino acids and a C-terminal peptide of 26 amino acids. The thermostability of the lipase was remarkably decreased by cleavage of the C-terminal peptide. Hence, we attempted to specify the amino acids in the C-terminal peptide that are responsible for the stabilization of the lipase. Replacement of Asp293 with Ala, Asn, and Lys caused a significant decrease in thermostability, but its mutation to Glu did not decrease the stability significantly. These findings showed that the lipase with the C-terminal peptide was stabilized by an ionic bond between the negative charge of Asp293 and positive charge of an amino acid of the N-terminal large peptide. The thermostability of the lipase gradually decreased with increasing deletion size from the C-terminus, and a 13-amino acid deletion decreased the stability to the level of the lipase not having the C-terminal peptide. These results suggested that the 13-amino acid region from the C-terminus participated in the lipase stability. In addition, the lipase production correlated well with the lipase stability, showing that the C-terminal peptide also influenced the lipase productivity.