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The transmitted light strength (TS) through a thin blood layer changes with variation in blood flow, such as positive streaming transparency for low hematocrits and negative streaming transparency for high hematocrits. These phenomena are examined theoretically and experimentally. Maxwell’s equations are solved assuming that erythrocytes are oblate spheroids to investigate these phenomena due to flowing blood. The theoretical results reveal that the scattering and absorption cross sections for flowing blood are larger than those for stagnant blood. Experimental results indicate that the TS for both oxygenated and deoxygenated flowing blood, with a hematocrit of up to approximately 20%, was stronger than that for stagnant blood. The TS decreased for flowing blood with a hematocrit of approximately 20% or greater. Applying the theoretical scattering and absorption cross sections to the absorption and multiple scattering theory of Victor Twersky, the changes in the TS due to flowing blood are obtained theoretically. From the theoretical and experimental results, the positive streaming transparency phenomenon of flowing blood with a low hematocrit and the negative streaming transparency phenomenon with a high hematocrit are found to result from increased scattering and absorption cross sections because of the orientation of flowing erythrocytes.

We used a stabilometer to examine development of postural control in 174 school-age boys aged 6-14. Subjects stood upright on a stabilometer for 30 s under both eyes-open and eyes-closed conditions. At that time, we determined the mean location of the center of pressure (CP), the migration area of CP, the migration distance of CP, and the mean migration velocity of CP (VCP) using the measuring instrument. Along with age, the sway in all measuring items decreased under both eyes-open and eyes-closed conditions so that it shows that posture control developed as age advanced. Each measuring item was evaluated according to the ability of discretion by Mahalanobis distance under both eyes-open and eyes-closed conditions. The greatest discretion through all grades was shown for VCP. Nevertheless, VCP decreases more with eyes open than with eyes closed, the difference grows larger between the ages of 9 and 11, indicating that the degree of dependence on visual information in postural control increases during that period. Differences between eyes-open and eyes-closed decrease after age 11; they become constant after age 12, indicating that the ability to maintain a stable posture is obtainable without much use of visual information.

Basic Life Support (BLS) is a rudimentary reanimation by common citizen. The execution of BLS improves lifesaving rate of Advanced Cardiac Life Support. Recently, the importance of the cardiopulmonary resuscitation education came to be pointed out in Japan. In this paper, the transition of the resuscitation technology is described. Next, the current state of the resuscitation is discussed. Finally, problems of resuscitation technology to be solved near future are also discussed.

MC-FANを用いて採血後, 血液試料の流動性を血液の通過時間を指標として解析した。血液試料の経時変化の要因は, 試料の血小板粘着凝集能の個人差を反映したものであることを見いだし, これは採血後10分以内に試料に応力変化を与えずに測定すればほぼ無視しうることが明らかとなった。このような条件のもと12名の成人健常者を対象として, 梅エキス粒の1カ月間摂取により, 1) 血小板粘着凝集能の高い血液では, 物理的ストレスへの耐性が高まること, 2) 血小板凝集性は示さないが, 流動性の低い血液は流動性が高くなること, 3) 血小板凝集性は示さないが, 流動性の高い血液は流動性が低くなること, 4) 全体として通過時間の平均値に収斂する傾向を得た。これらの実験事実から梅エキス粒の長期摂取は物理的刺激に過敏に反応して血小板粘着凝集する血液の性質を改善する予防医学的効果が示された。

In connection with the trends of the world, Japan experienced the dawn of biomedical engineering in the former half of the 1960's. Since then, biomedical engineering in Japan has certainly made a great progress. However, there seems to have been some critical problems peculiar to Japan. In this commentary paper, we refer to such problems, and propose ways to solve them to some extent.

The pharmacological differences between isopropyl unoprostone (referred to as unoprostone) and latanoprost, concerning their induction of endogenous prostaglandin E 2 (PGE 2 ) and affinity to a human prostaglandin transporter (PGT), were investigated. Freshly dissected bovine iris tissues were incubated with major intraocular metabolites of unoprostone, M1 and M2, acid of latanoprost, or PGF 2 α , and PGE 2 induction was measured. Affinities of M1, M2, latanoprost, acid of latanoprost, and PGF 2 α to PGT molecule were measured using PGT-cDNA transfected HeLa cells by an isotopic influx assay. 3 H-unoprostone was incubated with freshly prepared serum, aqueous humor, or frozen stored fetal bovine serum (FBS), and the radioactivity of supernatants was measured to investigate their metabolism of 3 H-unoprostone. M2, acid of latanoprost, and PGF 2 α significantly increased a release of PGE 2 compared with the control. 10 μ M indomethacin completely inhibited PGE 2 induction by acid of latanoprost and PGF 2 α , while 100 μ M indomethacin was required to inhibit PGE 2 induction completely by M1 and M2. Unoprostone, M1, M2, and latanoprost showed little affinity to PGT, while acid of latanoprost had an affinity to PGT. Freshly prepared serum and aqueous humor metabolized unoprostone, but frozen stored FBS did not. The release of endogenous PGE 2 may play an important role of action by means of PG analogs, and differences in indomethacin-related inhibition of PGE 2 release and in affinities to PGT may in part cause their different actions.

A Na(+)-independent organic anion transport protein was recently cloned from rat liver using a Xenopus laevis oocyte expression system [E. Jacquemin, B. Hagenbuch, B. Stieger, A.W. Wolkoff, and P.J. Meier, Proc. Natl. Acad. Sci. USA 91: 133-137, 1994]. Although expression of this protein is sufficient for cells to transport the organic anion bromosulfophthalein, little is known about its cell biology or biochemical characteristics. Northern blot analysis performed under high-stringency conditions revealed hybridization with RNA only from liver and kidney; transcripts appeared the same in these two organs. Within kidney, hybridization was greatest when RNA extracted from the outer medulla was used. Immunoblot analysis revealed that in liver, the transporter was enriched in 0.1 M Na2CO3-extracted membranes and sinusoidal plasma membrane preparations, consistent with its being an integral membrane protein. This 80-kDa protein migrated as a 65-kDa protein after treatment with N-glycanase. Immunomorphological examination of liver revealed basolateral plasma membrane localization. In 0.1 M Na2CO3-extracted membranes of kidney, the transporter migrated as an 83-kDa protein on nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). On reduction, it resolved into peptides of 33 and 37 kDa. SDS-PAGE migration of the liver protein was unaffected by reduction. Immunomorphological examination of kidney revealed apical plasma membrane localization in the S3 segment of the proximal tubule of the outer medulla. Differential processing and trafficking of this transporter in liver and kidney may have important functional and regulatory consequences.

A recently cloned cDNA encodes the so-called "organic anion-transporting polypeptide" (i.e., oatp), which is expressed in rat liver and in the kidney S3 proximal tubule. functional characterization of the cloned transporter indicates that estradiol 17 beta-D-glucuronide is a major substrate. Because the urinary excretion of glucuronidated steroids differs between males and females, we hypothesized that renal oatp expression may be under sex hormone control. Total RNA was isolated from male or female kidneys and probed with a digoxigenin-labeled oatp antisense riboprobe. Expression of oatp mRNA expression was quantitated by densitometry from Northern blots. Male kidneys expressed at least six distinct oatp transcripts (approximately 4.0, 3.2, 2.9, 2.6, 1.7, and 1.2 kb). Of these, the 3.2-kb band was consistently the strongest. In female rats, renal oatp mRNA expression was markedly less, such that only the 3.2-kb band was consistently detectable. Administering testosterone to female rats increased, and administering estradiol (E2) to male rats decreased, the steady-state levels of renal oatp mRNA. Gonadectomized male and female rats, as well as adrenalectomized male rats, were given pharmacological hormone replacement (testosterone, E2, or dexamethasone, respectively) by subcutaneous osmotic minipump. Castration of male rats produced a dramatic drop in the steady-state level of all six renal oatp transcripts. These were returned to normal by testosterone replacement. In contrast, there was no regulation of hepatic oatp mRNA expression by testosterone. Renal oatp mRNA expression in female rats was mildly increased by oophorectomy. Administration of E2 to oophorectomized females moderately suppressed renal oatp mRNA expression. Adrenalectomy produced a small decrease in oatp expression, but dexamethasone replacement failed to return expression to normal. We conclude that renal oatp mRNA expression is under strong (stimulatory) testosterone control and perhaps weaker (inhibitory) estrogen control. We speculate that this regulation of renal oatp expression is important in modulating the renal tubular secretion of conjugated E2.

Medical engineering plays important role in current medical care system, Whereas, legal aspect of incidents in clinical instrument operation have not been analyzed. This paper describes legal aspect of medical malpractice and negligence in medical instrument operation. Based on a case of incident that was concerned with a clinical engineer of a hospital, problems were analyzed from legal point of view.

Carrier-mediated prostaglandin transport has been postulated to occur in many tissues. On the basis of sequence homology, the protein of unknown function encoded by the rat matrin F/G complementary DNA was predicted to be an organic anion transporter. Expression of the matrin F/G complementary DNA in HeLa cells or Xenopus oocytes conferred the property of specific transport of prostaglandins. The tissue distribution of matrin F/G messenger RNA and the sensitivity of matrin F/G-induced prostaglandin transport to inhibitors were similar to those of endogenous prostaglandin transport. The protein encoded by the matrin F/G complementary DNA is thus preferably called PGT because it is likely to function as a prostaglandin transporter.

Current situation of therapeutic and diagnostic equipments and their clinical aspects are described. Topics of clinical applications and expected status of regenerative and gene engineering are also reviewed. Contributions of new clinical technology and several low invasive medical equipments are discussed for medical care system in incoming era.

The physical properties of tissues are of practical interest in medical engineering and various fields of medicine. In this study, the electrical time constants of living cells, especially erythrocytes, are discussed. β dispersion is often called as structural relaxation caused by cellular structure of tissues. The shape of cells, the membrane thickness of cells, the conductivity of intracellular fluid and the orientation of the cells affect the time constant of β dispersion. Therefore, we can get a lot of information such as intra- and extra-cellular volumes from β dispersion phenomenon. [1][2][3][4][8][11]. The electrical properties of blood can be analytically calculated by Fricke equation under some assumptions [9]. The most important assumption is that the shape of erythrocyte in blood approximated to the confocal ellipsoidal spheroid (shown in Fig.1). And all erythrocytes orient themselves so as to one of three –rectangular axis is parallel to the electrical field. This model has a single time constant, although the time constant of a real erythrocyte with constant membrane thickness must be distributed.

The physical properties of tissues are of practical interest in medical engineering and various fields of medicine. In this study, the electrical time constants of living cells, especially erythrocytes, are discussed. β dispersion is often called as structural relaxation caused by cellular structure of tissues. The time constant of β dispersion is affected by the shape of cells, the membrane thickness of cells, the conductivity of intracellular fluid and the orientation of the cells. Therefore, we can get a lot of information such as intra- and extracellular volumes from β dispersion phenomenon. The electrical properties of blood can be analytically calculated by Fricke’s equation under some assumptions. The most important assumption is that the shape of erythrocyte in blood approximated to the confocal ellipsoidal spheroid. This model has a single time constant, although the time constant of a real erythrocyte with constant membrane thickness must be distributed. As a result, the difference exists between the admittance locus analytically calculated from Fricke’s model and the experimental results obtained from blood. In this study, comparison of the results analytically calculated by Fricke’s equation and the results numerically calculated by boundary element method for the model with the constant membrane thickness were compared. From these results, the error of Fricke’s results can be estimated.

We recently identified a cDNA in the rat that encodes a broadly expressed PG transporter (PGT). Because PGs play diverse and important roles in human health and disease, we cloned human PGT (hPGT) from an adult human kidney cDNA library. A consensus sequence (4.0 kb) derived from several clones, plus 3' polymerase chain reaction amplification, exhibited 74% nucleic acid identity and 82% amino acid identity compared to rat PGT. When transiently expressed in HeLa cells, a full-length clone catalyzed the transport of PGE1, PGE2, PGD2, PGF2alpha, and, to a lesser degree, TXB2. Northern blotting revealed mRNA transcripts of many different sizes in adult human heart, placenta, brain, lung, liver, skeletal muscle, pancreas, kidney, spleen, prostate, ovary, small intestine, and colon. hPGT mRNAs are also strongly expressed in human fetal brain, lung, liver, and kidney. The broad tissue distribution and substrate profile of hPGT suggest a role in the transport and/or metabolic clearance of PGs in diverse human tissues.

Although substantial evidence indicates that estradiol-17 beta (E2) is conjugated to the glucuronide in the kidney and then excreted by a direct tubular secretory route and that the liver transports E2 glucuronides via carrier-mediated mechanisms, the transporters involved in these processes have not been identified. The so-called "organic anion-transporting polypeptide" (i.e., oatp) has a number of known substrates, including bromosulfophthalein (BSP) and taurocholic acid (TCA) (E. Jacquemin, B. Hagenbuch, B. Stieger, A. W. Wolkoff, and P. J. Meier. Proc. Natl. Acad. Sci. USA 91: 133-137, 1994). In a companion study, we determined that steroid hormones represent a class of hormones that interact strongly with oatp when the latter is transiently expressed in vitro. Here, we studied more extensively steroids and steroid anion conjugates as candidate oatp substrates. In HeLa cell monolayers transfected with a full-length oatp cDNA, [3H]estradiol 17 beta-D-glucuronide ([3H]E2-17G) was transported with a signal-to-noise ratio of 15:1 over that of monolayers transfected with a control plasmid. The affinity of oatp for [3H]E2-17G was significantly higher than that for TCA (K(m) of 3 microM vs. 27 microM, respectively). In contrast to E2-17G, unconjugated estradiol (E2) was not significantly transported by oatp. Several unconjugated steroids and anionic steroid conjugates were tested for their ability to compete with tracer E2-17G for oatp-mediated transport. Conjugation at the 17 or 3 position with the anion of a strong acid (sulfate) resulted in a greater degree of inhibition of tracer E2-17G transport than did conjugation at the 17 or 3 position with an uncharged group (acetate), suggesting that the strength of the negative charge at these positions is an important determinant of the affinity of a given steroid conjugate for oatp. We conclude that the preferred substrates for oatp are steroids with a strong 17- or 3-position anionic group. Since steroid sulfotransferases and glucuronosyltransferases are expressed in the proximal tubule, as is oatp, the transporter may serve as an apical exit pathway for steroids following their conjugation within the tubule cell.

The cDNA for the rat liver organic anion-transporting polypeptide "oatp" has been shown to encode transport of bromosulfophthalein (BSP) and bile salts in Xenopus oocytes (E. Jacquemin, B. Hagenbuch, B. Stieger, A. W. Wolkoff, and P. J. Meier. Proc. Natl. Acad. Sci. USA 91: 133-137, 1994). Because oatp mRNA is expressed strongly in the kidney, we sought to determine whether renal oatp might play a role in the known secretion of a large variety of organic anions by the kidney. We transiently expressed a full-length oatp cDNA, cloned in pSPORT, in HeLa cell monolayers using the recombinant vaccinia virus vtf7-3. We tested an array of organic anions as candidate substrates by determining their ability to compete with tracer BSP for transport. HeLa cell monolayers transfected with the oatp cDNA transported tracer BSP and taurocholate at rates substantially higher than monolayers transfected with a control plasmid. Thus good expression can be obtained with the vaccinia-HeLa system using a standard plasmid cloning vector. BSP transport varied as a function of the medium albumin, ionic conditions, and pH in a fashion similar to that in Xenopus oocytes. Several organic anions known to be secreted by the classic secretory pathway, including p-aminohippurate (PAH), phenol red, and indigo carmine (10 microM) failed to inhibit oatp-mediated BSP transport. Direct testing using tracers revealed no oatp-mediated transport of sulfate, urate, PAH, several eicosanoids, or unconjugated or conjugated bilirubin. On the other hand, BSP transport was inhibited by approximately 50% by 10 microM corticosterone sulfate, spironolactone, and several other steroids. We conclude that the functional properties of oatp expressed in the HeLa cell/vaccinia transient expression system are comparable to those following expression in Xenopus oocytes and that steroids are likely to represent high-affinity endogenous oatp substrates. The latter hypothesis is addressed in greater detail in a companion paper.

For the development of a communication-assisting device for disabled users using simplified symbols, legibility of displayed information must be investigated. In this study, to assess the symbol legibility an experimental study was carried out by using measurement of the P300 component of Event Related brain Potentials. Measured amplitudes and latencies of the P300 component were analyzed. Result suggested that the number of association items from a symbol may be influence on the latency of the P300 component.

To investigate the cognitive aspects of posture control under the apparent force condition generated by auditory stimulation, body sway fluctuation was measured with healthy adult subjects. As an experimental stimulation, an increasing tone for the left ear and a decreasing tone for the right ear were used.. Subjects felt that the sound source was moving from right to left under an eyes closed condition. On the contrary, subjects who were shown a moving image of a natural scene which was interlocked to the auditory stimulus before the experiment (cognitive preparation), they felt themselves moving from a left to right direction. In this experiment, body sway was measured with and without the cognitive preparation. Results showed that the center of gravity biased to the opposite direction of subjective movement of the sound source with cognitive preparation. Without cognitive preparation, the center of gravity biased in the same direction of subjective movement of the sound source. It suggests that the higher level posture control reflex was observed in the cognitive condition without any sensory input from the muscle receptors.

Reducing pressure is one of the most important factors in preventing decubitus. One way to reduce pressure is to redistribute pressure over as large an area as possible. Soft polyurethane mattresses are good for redistributing pressure, however this type of mattress does not provide sufficient back support. So in order to reduce pressure and provide sufficient support, we have developed a silicone gel layered mattress.Silicone gel is frequently used as a shock absorber in various types of machines and our tests showed that silicone gel was superior to standard polyurethane mattress materials in reducing interface pressure. The silicone gel layered mattress was also preferred by volunteers over a standard hard mattress and a standard soft mattress.

In this study we examined the proper pressure of air boots for a person in a sitting position. Air boots can improve calf congestion by pulsatile calf compression. Higher pressure may improve calf congestion more, though it might decrease arterial blood flow. A photo-electric plethysmometer was put on the second toe of a foot to measure the amplitude of the pulse which represent arterial blood flow. A sensor of a near infrared oxygen monitor was put on the calf just above an air boot. A near infrared oxygen monitor can detect tissue reduced hemoglobin which exists almost only in venous blood. So, the concentration of tissue reduced hemoglobin could represent tissue venous blood concentration.When the air boots pressure was more than 140mmHg, the amplitude of the arterial pulse decreased to half of that without massage. Pressure less than 70mmHg didn't affect arterial blood flow. Meanwhile pressures of more than 70mmHg didn't show any difference in the improvement of calf congestion. So, we concluded that the proper pressure for air boots massage for calf congestion in a sitting position is less than 70mmHg.