• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.282-290
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• 1997

Hepatocytes of Anguilla japonica have been prepared using a collagenase perfusion technique. The isolated cells attached efficiently to fibronectin-coated culture dishes and subsequently formed monolayers in serum-free medium. These cultures maintained in appropriate medium at least for 10 days with minimal cell loss. The effects of estradiol and pituitary hormones on vitellogenin (Vg) synthesis were examined in primary hepatocyte culture of the immature eels. In fish, as in other oviparous vertebrates, estrogen is a major inducer of Vg synthesis. However, $estradiol-17\beta(E_2)$ alone was insufficient to induce Vg synthesis in cultures of eel hepatocytes. Combination of $E_2$ with growth hormone (GH) and/or prolactin (PRL) markedly stimulated Vg synthesis. Even in cultures exposed to $E_2$ or precultured without hormones for 8 days, $E_2$ alone could not fully induce Vg synthesis. The synthesis of Vg was dramatically increased when hepatocytes were cultured in medium supplemented with $E_{2}+GH+PRL$ for 6 days. At this point, even though GH and/or PRL were eliminated from the medium, Vg synthesis was not influenced by these factors during culture of further 3 days. These results indicate that pituitary hormones, in particular GH and PRL, play important roles in the regulation of Vg synthesis in primary cultures of eel hepatocytes.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.27-47
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• 1992

Engineers have developed new instruments that aid in diagnosis and therapy Ultrasonic imaging has provided a nondamaging method of imaging internal organs. A complex transducer emits ultrasonic waves at many angles and reconstructs a map of internal anatomy and also velocities of blood in vessels. Fast computed tomography permits reconstruction of the 3-dimensional anatomy and perfusion of the heart at 20-Hz rates. Positron emission tomography uses certain isotopes that produce positrons that react with electrons to simultaneously emit two gamma rays in opposite directions. It locates the region of origin by using a ring of discrete scintillation detectors, each in electronic coincidence with an opposing detector. In magnetic resonance imaging, the patient is placed in a very strong magnetic field. The precessing of the hydrogen atoms is perturbed by an interrogating field to yield two-dimensional images of soft tissue having exceptional clarity. As an alternative to radiology image processing, film archiving, and retrieval, picture archiving and communication systems (PACS) are being implemented. Images from computed radiography, magnetic resonance imaging (MRI), nuclear medicine, and ultrasound are digitized, transmitted, and stored in computers for retrieval at distributed work stations. In electrical impedance tomography, electrodes are placed around the thorax. 50-kHz current is injected between two electrodes and voltages are measured on all other electrodes. A computer processes the data to yield an image of the resistivity of a 2-dimensional slice of the thorax. During fetal monitoring, a corkscrew electrode is screwed into the fetal scalp to measure the fetal electrocardiogram. Correlations with uterine contractions yield information on the status of the fetus during delivery To measure cardiac output by thermodilution, cold saline is injected into the right atrium. A thermistor in the right pulmonary artery yields temperature measurements, from which we can calculate cardiac output. In impedance cardiography, we measure the changes in electrical impedance as the heart ejects blood into the arteries. Motion artifacts are large, so signal averaging is useful during monitoring. An intraarterial blood gas monitoring system permits monitoring in real time. Light is sent down optical fibers inserted into the radial artery, where it is absorbed by dyes, which reemit the light at a different wavelength. The emitted light travels up optical fibers where an external instrument determines O2, CO2, and pH. Therapeutic devices include the electrosurgical unit. A high-frequency electric arc is drawn between the knife and the tissue. The arc cuts and the heat coagulates, thus preventing blood loss. Hyperthermia has demonstrated antitumor effects in patients in whom all conventional modes of therapy have failed. Methods of raising tumor temperature include focused ultrasound, radio-frequency power through needles, or microwaves. When the heart stops pumping, we use the defibrillator to restore normal pumping. A brief, high-current pulse through the heart synchronizes all cardiac fibers to restore normal rhythm. When the cardiac rhythm is too slow, we implant the cardiac pacemaker. An electrode within the heart stimulates the cardiac muscle to contract at the normal rate. When the cardiac valves are narrowed or leak, we implant an artificial valve. Silicone rubber and Teflon are used for biocompatibility. Artificial hearts powered by pneumatic hoses have been implanted in humans. However, the quality of life gradually degrades, and death ensues. When kidney stones develop, lithotripsy is used. A spark creates a pressure wave, which is focused on the stone and fragments it. The pieces pass out normally. When kidneys fail, the blood is cleansed during hemodialysis. Urea passes through a porous membrane to a dialysate bath to lower its concentration in the blood. The blind are able to read by scanning the Optacon with their fingertips. A camera scans letters and converts them to an array of vibrating pins. The deaf are able to hear using a cochlear implant. A microphone detects sound and divides it into frequency bands. 22 electrodes within the cochlea stimulate the acoustic the acoustic nerve to provide sound patterns. For those who have lost muscle function in the limbs, researchers are implanting electrodes to stimulate the muscle. Sensors in the legs and arms feed back signals to a computer that coordinates the stimulators to provide limb motion. For those with high spinal cord injury, a puff and sip switch can control a computer and permit the disabled person operate the computer and communicate with the outside world.

• Korean Journal of Adult Nursing
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• v.12 no.2
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• pp.234-244
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• 2000

It is widely recognized that manipulation of body position takes advantage of the influences of gravity for improving oxygenation. The study aims to determine the effects of positioning(supine, prone, right lateral decubitus and left lateral decubitus positions) applied to the mechanically ventilatory acute respiratory failure patients on arterial oxygen partial pressure($PaO_2$), alveolar arterial oxygen tension difference($AaDO_2$), mean aterial pressure, peak inspiratory pressure and plateau pressure. Thirty two acute respiratory failure patients admitted to the medical intensive care unit at Kangnam St. Mary's Hospital, The Catholic University of Korea from March 1997 to January 1998, were divided into three groups by radiographic evidence of unilateral or bilateral lung disease. In group 1 with dominant right lung disease were twelve subjects, group 2 with dominant left lung disease had eight subjects and group 3 had twelve subjects with bilateral lung disease. The variables were measured in 30 minutes after each position of supine, prone, good lung down lateral decubitus and sick lung down lateral decubitus position. The position order was done at random by Latin squre design. The results are as follows; 1) With group 1 patients, the $PaO_2$ in the left lateral decubitus and prone position were $126.8{\pm}30.8$ mmHg and $106.7{\pm}36.8$ mmHg, respectively(p=0.0001). 2) With group 2 patients, the $PaO_2$ in the prone and the right lateral decubitus position were $121.7{\pm}44.7$ mmHg and $118.5{\pm}31.7$ mmHg, respectively (p=0.0018). 3) With group 3 patients, the $PaO_2$ was $143.6{\pm}36.6$ mmHg in the prone position (p=0.0001). 4) With group 1 patients, the $AaDO_2$ in the left lateral decubitus and the right lateral decubitus position were $178.1{\pm}29.7$ mmHg and $233.1{\pm}24.4$ mmHg, respectively(p=0.0001). 5) With group 2 patients, the $AaDO_2$ in the prone and the left lateral decubitus postion were $184.0{\pm}39.5$ mmHg and $231.0{\pm}23.9$ mmHg, respectively(p=0.0019). 6) With group 3 patients, the $AaDO_2$ in the prone and the supine postion were $377.1{\pm}35.6$ mmHg and $435.7{\pm}13.1$ mmHg, respectively (p=0.0001). 7) There were no differences among the mean arterial pressure, peak inspiratory pressure and plateau pressure for each of the supine, prone, left lateral decubitus and right lateral decubitus position. The results suggest that oxygenation may improve in mechanically ventilatory patients with unilateral lung disease when the position is good lung dependent and prone, and patients with bilateral lung disease when the position is prone without any effects on the mean arterial pressure and airway pressure. It is suggested that body positions improve ventilation/perfusion matching and oxygenation need to be specified in patient care plans.