[Effects of closed-circuit breathing apparatus on respiration and metabolism]

The purpose of the study was to evaluate the influence of hyperoxia and hypercapnia on respiration and metabolism during a steady-state exercise. Thirteen healthy subjects were examined during bicycle-ergometer rides at approximately 50% VO2max under four different breathing gas conditions: 1) room air (control); 2) 40% oxygen; 3) 3% carbon dioxide; 4) 40% oxygen and 3% carbon dioxide. Hyperoxia, with or without hypercapnia, decreased respiratory ventilation and carbon dioxide elimination significantly. On the other hand, oxygen uptake in hyperoxia was not significantly different from that of normoxia. Hypercapnia increased respiratory ventilation more than 30% compared to normocapnia, but it did not change oxygen uptake and carbon dioxide elimination significantly.

Kinetic analysis of the disposition of MRK16, an anti-P-glycoprotein monoclonal antibody, in tumors: comparison between in vitro and in vivo disposition

The kinetics of the disposition of MRK16, an anti-P-glycoprotein monoclonal antibody, was studied in two human colorectal tumor cell lines, HCT-15 and COLO205, whose P-glycoprotein expression is extensive and poor, respectively. In a series of in vitro binding studies, the amount of MRK16 associated with HCT-15 cells at steady state was approximately 40 times greater than that associated with COLO205 cells. In in vivo studies, the disposition of MRK16 was determined in tumor-bearing mice after intravenous administration. The difference in the tumor-to-plasma concentration ratio between the two cell lines was only 2.3-fold at 72 hr after injection. To explain the large difference observed between the in vitro and in vivo results, a series of kinetic simulation studies were performed. By considering the physiological parameters specific for MRK16 (such as permeability-surface area product and the kinetic parameters determined in vitro), the time profiles for the tumor concentration were predicted. The predicted difference in the tumor-to-plasma concentration ratio at 72 hr was calculated to be 2.6-fold, although the permeability-surface area product across the tumor capillary and other physiological parameters were comparable between the two tumor cell lines. The discrepancy between the in vitro and in vivo results was accounted for by the fact that the tumor extracellular fluid concentration at this time point was 13-fold lower in HCT-15 tumors than in COLO205 tumors because of the restricted penetration of MRK16 through the tumor capillaries. This finding suggests that this factor accounts for the in vitro and in vivo difference in the tumor disposition of MRK16.

Methemoglobin formation in hemoglobin vesicles and reduction by encapsulated thiols

The hemoglobin vesicle (HbV) is a red cell substitute encapsulating purified concentrated Hb in a phospholipid vesicle. In order to suppress metHb formation or autoxidation, for the long-term maintenance of the oxygen transporting capability, a series of thiols (cysteine, Cys; glutathione, GSH; homocysteine, Hcy; and acetylcysteine, Acy) were studied as reductants of metHb. Hcy and GSH showed a good suppressive effect on metHb formation, while Cys adversely accelerates the metHb formation at a rate twice that of the Hb solution without any reductants and Acy showed no change. The significant suppression by the coaddition of superoxide dismutase (SOD) and catalase to Cys indicated that Cys was easily oxidized by oxygen and simultaneously generates a large amount of active oxygens. The effective suppression of metHb formation by SOD and catalase was not observed for HbV containing no reductants, indicating that the generation of active oxygens from Hb itself is not significant. The coencapsulation of Hcy with Hb resulted in a low rate of metHb formation in HbV (initial rate, 1%/h) in vitro at an oxygen partial pressure (Po2) of 142 Torr. The rate increased with decreasing Po2, showed a maximum (2.2%/h) around Po2 = 23 Torr, and then decreased to 0%/h at 0 Torr. From these results, it is suggested that the fast metHb formation rate in the blood circulation of Wistar rats injected with 20 vol % of the HbV solution would be mainly caused by the exposure of HbV to the low Po2.

Physical effects of negative air ions in a wet sauna

The physical effects of negative air ions on humans were determined in an experimental sauna room equipped with an ionizer. Thirteen healthy persons took a wet sauna bath (dry bulb temperature 42 degrees C, relative humidity 100%, 10 min exposure) with or without negative air ions. The subjects were not told when they were being exposed to negative air ions. There were no differences in the moods of these persons or changes in their blood pressures between the two saunas. The surface temperatures of the foreheads, hands, and legs in the sauna with negative ions were significantly higher than those in the sauna without ions. The pulse rates and sweat produced in the sauna with ions were significantly higher than those in the sauna without ions. The results suggest that negative ions may amplify the effects on humans of the sauna.

[Sympathetic skin responses in the face by magnetic stimulation of the neck]

We studied the sympathetic skin responses (SSRs) in the face with magnetic stimulation of the neck, in 10 normal healthy subjects. The SSRs were recorded with surface electrodes placed on the forehead, the lower eyelid, the apex nasi, two points of cheek (one is near the ear, and another is near the mouth), the upper lip, and the lower jaw. Reproducible SSRs were obtained easily at the forehead and the upper lip compared to the other parts of the face. The SSRs on the forehead and upper lip were constantly evoked after drinking of hot water. Mean latencies are 0.98 +/- 0.22 sec. (mean +/- 1SD) at the forehead, and 0.89 +/- 0.12 sec. (mean +/- 1SD) at the upper lip. In the cervical sympathetic pathway, one part of postganglionic fibers runs along the internal carotid artery to innervate the eyelids and forehead, whereas another part runs along the external carotid artery to innervate other parts of the face. It suggests that the forehead and the upper lip are representative parts of those different innervations SSRs in the forehead and the upper lip could be useful for evaluating the sympathetic function of the face in various diseases.

Alterations of fibrinolytic activity in human during and after hyperbaric oxygen exposure

To clarify the stage of fibrinolytic activation by hyperbaric oxygen (HBO) exposure, we examined its alterations in human during and after the HBO exposure. Eight healthy female volunteers breathed oxygen at 284 kPa (2.8 atmospheres absolute). Blood samples were collected before compression, shortly after compression to the pressure 284 kPa, shortly before the start of decompression, shortly after decompression, and then again 3 hours after decompression. We estimated the euglobulin fibrinolytic activity (EFA) and, the activities and antigens of both tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1). The PAI-1 activity and PAI-1 antigen showed significant decrease after compression to a pressure 284 kPa, before the start of decompression, and after decompression. The EFA level and t-PA activity rose significantly shortly after decompression, and 3 hours later returned on baseline. These findings suggest that fibrinolytic activity is elicited after HBO rather than during HBO.

[Safety evaluation of self-contained-self-rescures--carbon dioxide absorption of SCSRs under heavy work load]

The purpose of this study was to evaluate the safety of Self-Contained-Self-Rescuers (SCSRs) under a heavy work load. Three units, two chemical-oxygen (KO2) types and one compressed-oxygen type, were evaluated by a breathing and metabolic simulator and by a human subject. The metabolic rate in the simulator tests was equivalent to light work; the human subject tests were at a heavy work load. With regard to the main physiological stressors imposed by SCSRs, it was found that the inhalation temperature under heavy work conditions was able to be estimated from the data of the light work condition; the breathing resistance had roughly the same relationship under both light and heavy work conditions. On the other hand, for the inhaled carbon dioxide, there was no correlation between the two conditions. It was found that some SCSRs experienced a rapid increase in inhaled carbon dioxide when the metabolic rate of the user exceeded the absorbent capacity of the units. In those cases, the user could not continue walking nor breathing through the unit. To ensure the safety of the user, we propose that the certification standards be changed to include evaluation of carbon dioxide absorbent capacity under heavy work load.

An intergenerational contraction of the CTG repeat in Japanese myotonic dystrophy

We present the first report of a Japanese family with myotonic dystrophy (DM) that showed an intergenerational contraction of the CTG repeat. The size of the expanded CTG repeats was 3.2 kb for the father and 2.2 kb for the daughter, indicating that the expansion decreased during transmission from the father to the daughter. Despite the CTG repeat contraction, the daughter showed earlier age of onset than the father. However, she appeared to be less severely affected than the father. We discuss the correlation between the CTG repeat contraction and the clinical phenotype. The presence of the CTG repeat contraction in Japanese DM is important for genetic counseling of Japanese DM families.

The relationship between trinucleotide repeat length and phenotypic variation in Machado-Joseph disease

Trinucleotide repeat expansion in the Machado-Joseph disease (MJD) gene has been found in 26 patients from 20 unrelated Japanese families. Expanded alleles had 68 to 84 repeats, whereas normal alleles had 14 to 37 repeats. The age of onset was inversely correlated with the repeat length. To evaluate in detail the relationship between the repeat length and clinical features, we subdivided the 26 patients into three groups on the basis of the repeat length (group 1, 78 repeats or more; group 2, 74 to 77 repeats; group 3, 73 repeats or less). Group 1 and group 2 had common features of spasticity, hyperreflexia, Babinski sign, bulging eyes, facial myokymia and extrapyramidal signs as well as cerebellar ataxia and ophthalmoplegia. It should be noted that group 1 showed more prominent pyramidal and extrapyramidal signs than group 2. In contrast, group 3 showed hypotonia, hyporeflexia and sensory disturbance in addition to cerebellar ataxia and ophthalmoplegia. These findings suggest that the repeat length plays an important role in phenotypic variation. DNA analysis for the MJD mutation was clearly useful for making an accurate diagnosis in patients without bulging eyes, facial myokymia, dystonia or marked spasticity.

Effect of tumor necrosis factor alpha on intrahepatic bile duct epithelial cell of rat liver

Tumor necrosis factor alpha (TNF-alpha), which is primarily produced by macrophages, is a cytokine with various biological activities. Macrophage infiltration often accompanies experimental cholangitis in rats, and chronic cholangitis in humans. The pathophysiologic significance of TNF-alpha in cholangitis is not known. We used cultured, polarized intrahepatic bile duct epithelial cells (IBDECs) from rat liver to determine whether TNF-alpha directly affects the organization of IBDEC monolayers. The addition of recombinant TNF-alpha (rTNF-alpha) to culture media at concentrations from 10 to 200 U/mL lacked cytotoxicity to the IBDECs as judged by trypan blue exclusion and lactate dehydrogenase (LDH) release. rTNF-alpha transiently reduced transepithelial electrical resistance in a dose-dependent manner. During this decrease in resistance, the cellular tight junctions became leaky, allowing horseradish peroxidase (HRP) penetration. rTNF-alpha, at concentrations up to 200 U/mL, did not detach IBDECs from Matrigel, an artificial basement membrane. Electron microscopy and immunohistochemistry for F-actin showed a well-preserved cell structure and organization of IBDECs. Results suggest that TNF-alpha is nontoxic to IBDECs, and that it increases the permeability of tight junctions. TNF-alpha may thus disturb the barrier function of the bile duct.

[Aging of brain and the maintenance of the function]

Some diseases develop dementia, but they may be dementia-like-situation, such as depression and drugs induced one. There are many causes as an etiology of dementia. Among them a lots of diseases are treatable dementia, like chronic subdural hematoma, normal pressure hydrocephalus, brain abscess, syphilis, herpetic encephalitis, Wilson's disease, hypothyroidism, parathyroid disease, vitamin B12 deficiency, pellagra etc. In examination of patients with dementia, exact history taking, physical examination and laboratory examination should be done carefully. In the patients with Alzheimer's dementia and cerebrovascular disease's dementia, as many risk factors are known, we must try to treat and exclude each risk factor and protect the dementia. Inactivity of physical and mental function is reported to induce the dementia, so activation of them could prevent the development and the progression of dementia. In future the methods of the prevention of apoptosis and cell death would be found in order to prevent the dementia. Free radical scavenger, nerve trophic factor, cytokine, antagonist of glutamate etc. will have the possibility to become the medicine for the dementia. The nerve transplantation, nerve transmitter, nerve peptide etc. might serve as the allopathic treatment for the dementia.

[Health check on divers and compressed air workers]

We have conducted the health check of 3,554 compressed air workers and 1,821 divers, and also examined the incidence and severity of aseptic bone necrosis by using Roentgen pictures. We could classify 4,859 of 5,375 persons into four groups (A-D), based on our classification. We could also classify 4,205 of 5,375 persons that had had a bone X ray examination on the basis of the criteria described by Ota and Matsunaga (A-C). 4,859 persons belonged to four groups: class A (persons who can work, no limitations): 4,099 (84.4%), class B (persons who can work under conditions below 1.0 kg/cm2): 357 (7.3%), class C (persons who had better quit work under hyperbaric conditions, though they are not prohibited by regulations): 183 (3.8%), class D (persons who must be prohibited from working in a hyperbaric environment by laws of the Ministry of Labor): 88 (1.8%). About 90% of compressed air workers and divers (classes A and B) were permitted to work under hyperbaric conditions. Most of those belonging to classes C and D suffered from hypertension, cardiovascular disease and liver dysfunction. The incidence of aseptic bone necrosis was 11.1% (465 out of 4,205 persons). Eight persons (2.2%) belonged to criteria A which means poor prognosis. They were classified into class D. There is no differences between compressed air workers and divers in the incidence of aseptic bone necrosis.

[Serum levels of soluble adhesion molecules in patients with inflammatory myopathies]

Serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured by ELISA in patients with 18 inflammatory myopathies as well as 23 healthy controls. Both serum sICAM-1 and sVCAM-1 levels were elevated in patients with active polymyositis. Serum sVCAM-1 levels were elevated in the active stage of dermatomyositis, while sICAM-1 levels were elevated only in patients with dermatomyositis complicated with interstitial pneumonia. In paired serum samples before and after prednisolone therapy, elevated serum sICAM-1 and sVCAM-1 levels decreased in patients responding well to steroid therapy without complications. These findings suggested that soluble adhesion molecules reflect as the clinical activity of inflammatory myopathies.

[Motor reorganization in the motor cortex]

Plasticity within the human central motor system has been studied with transcranical magnetic stimulation in patients with peripheral and central nervous diseases. In 4 patients with a complete upper limb palsy due to traumatic cervical root avulsion, surgical anastomosis of intercostal to musculocutaneous nerves was performed to restore function in the biceps brachii muscle. The motor unit discharges became independent from respirations gradually over 1 to 2 years. Motor cortex mapping of the reinnervated biceps muscle showed a gradual change over 4 to 33 months from the area of the intercostal muscles to that of the arm area, which was more lateral on the motor cortex. These findings suggest that reorganization of the motor cortex to arm flexor muscles occurs following peripheral nerve anastomosis. In 8 patients with chronic cerebral infarction with hemiplegia. Four of 8 patients did not show MEPs in paralytic hand muscles by contralateral cortex stimulation, but showed small MEPs by ipsilateral cortex stimulation. These cases had the huge cortical infarction unilaterally in CT. Another four of 8 patients showed small MEPs in paralytic hand muscles by contralateral cortex stimulation, but no MEPs by ipsilateral cortex stimulation. These cases had the subcortical infarction unilaterally in CT. These findings suggest that reorganization of motor cortex following unilateral cerebral infarction.

Confluent monolayers of bile duct epithelial cells with tight junctions

The culture of fully differentiated intrahepatic bile duct epithelial cells (IBDECs) to use as a model for the in vivo intrahepatic biliary tract has not been established. IBDECs from normal rat livers were grown on a collagen-coated permeable filter and formed a confluent monolayer 7 days after being plated. Positive reactions for cytokeratin-19 and retained gamma-glutamyl transpeptidase (GGTP) activity were shown. The transepithelial electrical resistance between the apical and the basolateral compartment culture chambers increased with the culture age and plateaued after the 7th day. The resulting cultured cells displayed a number of characteristics. (1) The cells formed a thin, continuous monolayer and displayed microvilli on the apical surface and junctional complexes between the cells, consistent with in vivo IBDECs. (2) Cells cultured for more than 7 days prevented the passage of horseradish peroxidase (HRP) and ruthenium red through paracellular pathways. (3) Seven-day-old cultures displayed a mean transepithelial electrical resistance of 137.3 omega-cm2, which decreased by 27.1% from its initial level after cell treatment with ethylenediamineteraacetic acid (EDTA). These results indicate that confluent IBDEC monolayers are well differentiated and polarized with tight junctions (TJs) between the cells. These cell monolayers can provide a useful and relevant model for the in vitro study of various in vivo bile duct phenomena.

[A study of heel-knee tapping test in cerebellar ataxia by a motion measurement system]

It is often difficult to estimate slight alterations in the severity of ataxia by bed-side neurological examinations. We analyzed the heel-knee tapping test, which has often been used as a standard bed-side examination to check incoordination in lower limbs, using a new motion measurement system "video/computer motion measurement system". We studied 9 normal controls and 21 patients with spinocerebellar degenerations (SCD). In patients with SCD, the up-and-down motion range of the heel was variable and the heel moved in the anterior-and-posterior direction, because of knee sways during the test. Following oral administration of TRH analogue, TA-0910, above-mentioned findings were clearly improved. Analysis of spatial and time elements of the knee joint demonstrated quantitative improvement. Therefore, an effect of TA-0910 on incoordination of the lower limbs could be proved objectively by a computer motion measurement system.

Central motor reorganization after anastomosis of the musculocutaneous and intercostal nerves following cervical root avulsion

In 4 patients with a complete upper limb palsy due to traumatic cervical root avulsion, surgical anastomosis of intercostal to musculocutaneous nerves was performed to restore function in the biceps brachii muscle. Four to 6 months after the operation, motor unit discharges were recorded from the biceps muscle on the operated side during deep breathing and by cortical magnetic stimulation. The motor unit discharges became independent from respirations gradually over 1 to 2 years. The latencies of the motor potentials evoked by cortical and thoracic root magnetic stimulation decreased gradually over 2 to 3 years. Motor cortex mapping of the reinnervated biceps muscle showed a gradual change over 4 to 33 months from the area of the intercostal muscles to that of the arm area, which was more lateral on the motor cortex. These findings suggest that reorganization of the motor cortex to arm flexor muscles occurs following peripheral nerve anastomosis.

A novel life cycle arising from leaf segments in plants regenerated from horseradish hairy roots

Horseradish (Armoracia rusticana) hairy root clones were established from hairy roots which were transformed with the Ri plasmid in Agrobacterium rhizogenes 15834. The transformed plants, which were regenerated from hairy root clones, had thicker roots with extensive lateral branches and thicker stems, and grew faster compared with non-transformed horseradish plants. Small sections of leaves of the transformed plants generated adventitious roots in phytohormone-free G (modified Gamborg's) medium. Root proliferation was followed by adventitious shoot formation and plant regeneration. Approximately twenty plants were regenerated per square centimeter of leaf. The transformed plants were easily transferable from sterile conditions to soil. When leaf segments of the transformed plants were cultured in a liquid fertilizer under non-sterile conditions, adventitious roots were generated at the cut ends of the leaves. Adventitious shoots were generated at the boundary between the leaf and the adventitious roots and developed into complete plants. This novel life cycle arising from leaf segments is a unique property of the transformed plants derived from hairy root clones.

Studies on carbon material requirements for bacterial proliferation and spore germination under stress conditions: a new mechanism involving transmission of physical signals

The growth of bacteria is often enhanced by addition of carbon materials such as graphite or activated charcoal to the growth medium. In this work, bacterial strains that strictly require such carbon materials under the ordinarily lethal stress caused by high concentrations of salt were isolated. The organisms were gram-positive, spore-forming, sugar-nonfermenting aerobic bacilli and were provisionally designated "Bacillus carbophilus" Kasumi after examination of their phenotypic traits. The growth- and germination-promoting effects of graphite and activated charcoal were demonstrated either quantitatively on agar plates containing fine crystals of the carbon materials mixed with a nonpermissive growth medium or qualitatively on agar plates on nonpermissive growth media half-covered with fine carbon particles. Further experiments demonstrated a novel feature of the phenomenon; i.e., the ability to induce colony formation on the nonpermissive plate was transmissible through the air, as well as through plastic or glass barriers. The mechanism probably involves transmission of physical signals regulating cell growth.

[Saturation diving system at high altitude]

Practical saturation diving was firstly performed at high altitude in Japan in 1987. Its work was to change the screen which had covered the pipeline of a hydroelectric dam located 850 meters above sea level, the same operation had been conducted in 1992 and in 1993, 2 times each year (Total = 5 operations) after the work. The saturation dives have lasted from six to eight days on 4 occasions and 13 days (Total duration = 4075 minutes) on 1 occasion, since the initial pressurization until the end of the last decompression. In each operation, there had always been involved 3 divers. They have been compressed to an equivalent depth of 45-73m in the deck decompression chamber (DDC), briefed for work and transferred to the submersible decompression chamber (SDC), which was then submersed to 53-78m of depth. Wearing heated suit and breathing Heliox (both at the same temperature as the inside of the SDC), the divers have been locked out to perform their tasks, all monitored and supervised by the use of a remotely operated vehicle (ROV). The works have run uneventful and successfully until the end. The water temperature had been higher than the expected, i.e. 9-13 degrees C in all occasions. The inside conditions of the chamber had been the following: partial pressure of nitrogen was from 0.78 ATA; partial pressure of oxygen was from 0.35 to 0.40 ATA; partial pressure of carbon dioxide was less than 0.005 ATA; the inside temperature of the SDC was from 26 to 30 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

[Evaluation of physical exercise and fatigue sensation by CFSI (Cumulative Fatigue Symptoms Index)]

Cumulative Fatigue Symptoms Index (CFSI) is used for workers' subjective assessment of feeling of fatigue and of symptoms. Until now, this index has been used in the analysis of members of the same occupation. The purpose of this study is to examine fatigue symptoms in workers and to assess by CFSI the effect of regular physical exercise. Study participants were an exercise group (n = 67) and a non-exercise group (n = 115) of older workers, aged from 30 to 69 years. The CFSI questionnaire was distributed to all participants and the former group (exercise) answered two descriptive questions concerning the aim and subjective effects of physical exercise. As a result, it was found that mental fatigue symptoms decreased in the exercise group even after considering the differences in managerial position, subjective senses on health and marital status which are related to degree of feelings of fatigue. Weakened vitality was significantly less in the exercise group than the non-exercise group. Therefore, we concluded that weakened vitality would be needed to be regarded on an assessment scale for effects caused by exercise. It has also been considered that we should investigate general fatigue in assessing physical fatigue relating to one's lifestyle.

Sweat function in Parkinson's disease

Sweat function was studied in patients with Parkinson's disease and in normal adults by sympathetic skin response, the bromphenol blue printing method and the silicone mould method. In patients with Parkinson's disease, dysfunction of sweating was classified into two types: one type involved the postganglionic fibres and the other involved the preganglionic fibres or the central nervous system. The latter was observed in patients with milder disease and the former was observed in patients with severe disease. The progressive involvement of sweat function in Parkinson's disease may reflect spread from the central nervous system or preganglionic fibres to postganglionic fibres. In a few patients the results of sweat tests were normal. Ceruletide increased sweating in Parkinson's disease patients, and decreased the prolonged latency of the sympathetic skin response. It is hypothesized that ceruletide facilitates the preserved somatosympathetic reflex of sweating.