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Biomedical subjects

H Sawada

Publications and source records attributed to H Sawada.

At least 559 records · Page 31Linked to original sources
PubMed1979

Changes in intracellular activities of lysosomal enzymes in tissues of rats during aging.

A comparison of results obtained from studies of the intracellular fractions of the tissues of liver, brain and heart of "young" (1-2 months), "old" (24-27 months) and "senile" (34-37 months) rats showed that the ratios of three enzymes, acid phosphatase, beta-N-acetylglucosaminidase and acid RNase of the liver and heart were very similar and their activities decreased with age. On the other hand, the protein content is the supernatant of the liver, and acid DNase activities in the supernatant of the brain increased significantly with age. When the 24-27 month and 34-37 month old rats were compared, the ratios of the total activities of liver beta-N-glucosaminidase and brain acid DNase in the supernatant and the specific activities of brain beta-N-glucosaminidase in the microsomal fraction increased significantly.

Acid Phosphatase↗
PubMed1979

Purification and properties of reductases for aromatic aldehydes and ketones from guinea pig liver.

NADPH-dependent enzymatic reduction of aromatic aldehydes and ketones observed in the cytosol of guinea pig liver was mediated by at least three distinct reductases (AR 1, AR 2, and AR 3), which were separated by DEAE-cellulose chromatography. By several procedures AR 2 and AR 3 were purified to homogeneity, but AR 1 could be purified only 30-fold because of the small amount. These enzymes were found to have similar molecular weights of 34,000 to 36,000 and similar Stokes radii of about 2.5 nm. AR 3 was identical to aldehyde reductase [EC 1.1.1.2] in substrate specificity for aromatic aldehydes and D-glucuronate and specific inhibition by barbiturates. AR 1 and AR 2 acted on aromatic ketones and cyclohexanone as well as aromatic aldehydes at optimal pHs of 5.4 and 6.0, respectively, and were immunochemically distinguished from AR 3. AR 1 was the most sensitive to sulfhydryl reagents, and AR 2 was more stable at 50 degrees C than the other enzymes. Similar heterogeneity was observed in the kidney enzymes, but other tissues had little aldehyde reductase activity and contained only AR 3. In addition, lung contained a high molecular weight aromatic ketone reductase different from the above reductases.

Aldehyde Oxidoreductases↗
PubMed1979

Guinea pig liver aromatic aldehyde-ketone reductases identical with 17 beta-hydroxysteroid dehydrogenase isozymes.

Two NADPH-dependent aromatic aldehyde-ketone reductases purified from guinea pig liver catalyzed oxidoreduction of 17 beta-hydroxysteroids and 17-ketosteroids. One enzyme efficiently oxidized 5 beta-androstanes and reduced 17-ketosteroids of A/B cis configuration, whereas the other enzyme efficiently oxidized 5 alpha-androstanes and equally reduced both 5 alpha-and 5 beta-androstanes of 17-ketosteroids. However, aromatic aldehydes and ketones, and 3-ketosteroids were irreversibly reduced by the two enzymes. The two enzymes utilized NADP+ or NADPH as cofactor, but little activity with NAD+ or NADH was found. Phosphate ions enhanced the NAD+-dependent dehydrogenase activity and NADH-dependent reductase activity of the two enzymes, whereas the activities with NADP+ and NADPH were not affected. The ratios of the two activities of ketone reduction and 17 beta-hydroxysteroid oxidation of the two enzymes were almost constant during the purification steps after the two enzymes had been separated by DEAE-cellulose chromatography. By kinetic studies and electrophoresis and isoelectric focusing experiments it was confirmed that both of the two enzymes were responsile for the reduction aldehydes, ketones, and ketosteroids and for the oxidation of 17 beta-hydroxysteroids. These results indicate that 17 beta-hydroxysteroid dehydrogenases may play important roles in the metabolism of exogeneous aldehydes and ketones as well as steroids.

17-Hydroxysteroid Dehydrogenases↗
PubMed1979

Effects of methylmercuric chloride intoxication on the intracellular activity of lysosomal enzymes in rat liver and brain.

The activity of the lysosomal enzymes of rat liver after a single intraperitoneal injection of methylmercuric chloride (5.0 mg/kg) was enhanced in the nuclear fraction during early post-injection (2 hr to 7 days), while it decreased in the mitochondrial fraction and increased in the lysosomal fraction during late post-injection (14 days). Rat brain activity, however, was reduced in the nuclear, mitochondrial and lysosomal fractions during late post-injection (14 days). A high accumulation of total mercury was observed in the liver during early post-injection (36 hr and 7 days) while similar accumulation in the brain occured during late post-injection (7 days and 14 days). Both the mercury burdens and the enzyme activities of the rat liver and brain returned to normal levels within 30 days.

Animals↗
PubMed1979

Analysis of the process of cell degradation induced by Triton X-100 in Ehrlich ascites tumor cells.

Analysis of the liberation degrees of intracellular materials from Ehrlich ascites tumor cells by treatment of Triton X-100 was performed. The liberation process has two stages. In the first stage, cytoplasmic inorganic phosphorus were liberated at a concentration of about 0.01% of the detergent, and in the second stage macromolecules such as lysosomal enzymes were liberated at a concentration of about 0.03% of the detergent. Morphologically, the cells began to swell in the first stage but were not stained by Trypan blue, and the cells in the second stage became fully swollen and ruptured. The staining curve of the swollen and ruptured cells was closely in parallel with the liberation curves of the macromolecules.

Animals↗
PubMed1979

[Respiratory distress in the newborn (author's transl)].

Diseases which manifest with the respiratory distress in the newborn include 1) respiratory diseases-IRDS, type II RDS, neonatal asphyxia, and MAS etc. 2) anemia, CHD 3) CNS and 4) metabolic diseases. Among these, IRDS has high mortality rate because of the lack of the pulmonary surfactant and immaturity of respiratory center, and has many difficult problems in terms of its prevention and respiratory management. The points of its respiratory management are as follows: 1) Estimation of the level of arterial oxygen ation-this is the most important point. It has become possible, these days, to monitor continuous oxygenation using a transcutaneous oxygen electrode. 2) Knowledge of the physiology & management of apnea, and monitoring of heart rate and respiration. 3) Correction of acidosis & anemia and the nutritional supply by the intraveonous fluid administration. 4) Airway maintenance. 5) Oxygen administration to main PaO2 or tc PO2 of 60--80 mmHg. 6) Artificial ventilation by CPAP or IMV and 7) The specific drug therapy includes indomethacin for PDA associated with IRDS, Tolazoline for the fetal circulation syndrome, and Xanthine derivatives for primary apnea. 8) However, improvement by exchange transfusion has been contro-versial. On the other hand, in the type II RDS which has a relatively good prognosis, the intact survival can be expected by means of the proper management of general condition and respiration. In MAS, pneumothorax, pneumomediastinum and severe asphyxia, the proper resuscitation, oxygen administration should be given according to several conditions, especially the degree of hypoxia. The peritoneal dialysis can be lifesaving in case of severe renal impairment with RD. As the respiratory distress in the newborn is very frequent in its occurrence and death rate, its proper management is expected to result in the decrease in the newborn death rate in Hokkaido (8.1--6.6 per 1,000 live births) and the increase in the survival rate without any handicap, particularly if hospitals in each Hokkaido district give the newborn medical care more intensively than at present.

Humans↗
PubMed1979

Lipopolysaccharide responsiveness of malignant lymphoid cells in a patient with hairy cell leukemia.

The malignant cells in a patient with hairy cell leukemia responded most evidently to lipopolysaccharide (LPS) in in vitro culture for 3 1/2 days when the conventional tritiated thymidine uptake method was used. Since the malignant cells from patients with several other forms of leukemia and the peripheral blood mononuclear cells from healthy individuals did not show a comparable degree of responsiveness to LPS, we could exclude the possibility that this response was due to effects on contaminating normal mononuclear cells or to the nonspecific conditioning effect through LPS-affected contaminating normal monocytes. Morphological changes were observed with photo- and electronmicroscopy. It is likely that the hairy cells from the patient did respond to LPS, and whether or not this phenomenon may be confined to this type of lymphoid leukemia is not being investigated.

Adolescent↗
PubMed1978

High resolution scanning electron microscopy of frog sartorius muscle.

A field emission-type scanning electron microscope (SEM) was used to study the three-dimensional ultrastructure of frog sartorius muscles. Various preparative procedures were tested to seeks better specimen preparation for high resolution SEM observation. Procedures should be chosen depending on the information desired. The cell surface and intracellular organization of muscle fibers were best visualized when the tissues were fixed with tannic acid-OsO4 and torn after critical point drying. The basal lamina appeared as a continuous felt-like layer, onto which fine filamentous materials adhered. The true outer surface of the sarcolemma was not seen, whereas the true inner surface was occasionally exposed and exhibited numerous caveolae, membraneous fragments and fine filaments attached to its surface. In freeze-fractured and dried tissues, the cleaved sarcolemma showed numerous apertures of caveolae and T-system tubules. Inside the cell, the myofibrils showed a typical branding pattern of the sarcomere. Thick myofilaments were regularly beaded except for the pseudo-H-zone. Around the myofibrils the sarcoplasmic reticulum and T-system were also clearly observed. The results are discussed with special reference to the usefulness and limitation of the high resolution SEM in studying the ultrastructure of cells and tissues.

Animals↗
PubMed1978

Contact angle and surface tension in studies of lung surfactant.

The contact angle (theta) was determined in combination with surface tension measured in a Langmuiur-Willhelmy surface tension balance. Correction of the surface tension by the contact angle factor (1/cos theta) was tried on the monolayer curve of dipalmitoyl phosphatidyl choline (DPPC) and total lipid extracts from the bovine lung surfactant material (TLE). The contact angle was observed with an optical apparatus called a Contangulometer and pictures taken discontinuously, and was determined by drawing tangents at the peak of a junction between the water mensicus and a glass plate. The contact angle was about 15 degrees, and had a narrow range of variation until the surface tension became very low, less than 5 dynes/cm, and then the contact angle jumped to almost 90 degrees both in DPPC and in TLE. It is concluded that the directly recorded surface tension curve underestimates the value by about 3-4% and that when the surface tension becomes very low, less than 5 dynes/cm, the value is no longer valid because the contact angle becomes nearly 90 degrees.

Methods↗
PubMed1978

DNA repair in human leukemic leucocytes treated with neocarzinostatin.

Neocarzinostatin, an antineoplastic agent which is effective against human leukemia, induced unscheduled DNA synthesis in human leukemic leucocytes. This indicated the existence of repair process against at least a part of DNA damage caused by the agent. The extent of unscheduled DNA synthesis increased in parallel with the concentration of Neocarzinostatin up to 5 microgram/ml, followed by a decline at more than 5 microgram/ml. Leucocytes from patients with chronic myelogenous leukemia had higher repair synthesis after Neocarzinostatin treatment compared to those from patients with acute leukemia. The amount of repair synthesis correlated well with the proportion of immature leucocytes among chronic myelogenous leukemia samples, but such correlation was not found among acute leukemia samples.

Adolescent↗