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Biomedical subjects

M Kan

Publications and source records attributed to M Kan.

At least 145 records · Page 8Linked to original sources

Protective effect of the serum against cellular damage by active oxygen in culture.

It has been known that there is remarkable antioxidant activity in the human sera, especially those in inflammation and pregnancy. In the present investigation, various sera were examined for the antioxidant activity with the aid of cultured cells. It was recognized that the serum added to the culture medium protected cells from harmful action of active oxygen generated by a hypoxanthine-xanthine oxidase (HX-XO) system. The inflammatory serum has the greatest protective power, followed by pregnant and normal sera in this order. The antioxidant activity of the serum was inversely related to the Fe concentrations. The addition of ceruloplasmin with SOD action could not inhibit the tissue damage, while addition of catalase or hemoglobin with catalase activity could inhibit it. The protective effect was valid against not only HX-XO, but also H2O2. These results show that the chief active oxygen to cause cell damage is H2O2 and the scavenger antioxidants in the serum are hemoglobin and catalase.

Antioxidants↗

Effects of ceruloplasmin and the haptoglobin-hemoglobin complex on the oxygen-dependent reduction in growth of human diploid fibroblasts in serum-free, albumin containing medium.

We examined that growth-promoting activity of two different human albumin (HSA) preparations for human diploid fibroblasts in serum-free RITC 80-7 medium. The activity of one preparation (sample A) was affected markedly by environmental oxygen, whereas the other (sample B) was little affected. Sample B contained ceruloplasmin (Cp) and haptoglobin (Hp) as impurities. To detect the generation of superoxide anion in the media the amount of reduction of cytochrome c that is inhibited by superoxide dismutase (SOD) was determined. In an aerobic environment it was relatively large in comparison with reduction inhibited in a hypoxic environment. Reduction in the sample A with HSA-supplemented medium was relatively large in comparison with that in sample B with HSA-supplemented medium. The reduction of cytochrome c also was inhibited by Cp (25 mg/l) and catalase (4000 units/ml). Moreover, SOD, Cp, catalase and Hp.Hb (but not Hp) partially prevented oxygen-dependent reduction in growth in an aerobic environment when added to sample A HSA-supplemented medium. These results suggest that Cp and Hp.Hb act as an antioxidants in culture.

Blood Protein Electrophoresis↗

Differential growth requirements of serum factors (bovine serum albumin and low density lipoprotein) for normal and transformed human cells in a serum-free culture.

Serum-free culture is a useful method for identifying the growth requirements of normal cells of human origin and comparing them to the requirements of transformed human cells. We examined differential growth requirements of serum factors (bovine serum albumin (BSA) and low density lipoprotein (LDL) on normal (HEL), Co-60 gamma ray-transformed (CT-1) and 4-nitroquinoline 1-oxide-transformed (SUSM-1) human fibroblast cells in the absence of serum. A decreased requirement for serum was closely related to a decreased requirement for BSA in both types of transformed cells. The growth rate and saturation density of HEL and CT-1 cells grown in serum-free medium supplemented with the optimal concentrations of BSA were almost equal to the rates of cells grown in serum-supplemented medium. When BSA alone was added to the serum-free medium it did not support the continuous growth of SUSM-1 cells because of cellular detachment. An addition of LDL to serum-free cultures not only promoted the moderate growth of HEL cells, it promoted the continuous growth of SUSM-1 cells as well. In contrast, LDL was not required for the optimal growth of CT-1 cells. Transformed human cells specifically had reduced quantitative and qualitative growth requirements for one or more serum factors.

Blood↗

Oxygen-dependent growth declining and effect of vitamin E for human diploid fibroblasts in serum-free, BSA-containing culture.

Growth promoting activity of bovine serum albumin for human diploid fibroblasts was affected by oxygen environment. When cells (2 X 10(4) cells/35 mm dish) were cultured with BSA of 5 g/liter supplemented RITC 80-7 under hypoxic (7%) environment, excellent growth was maintained during the period of culture, while the growth under aerobic environment markedly declined after 3 days of culture. The culture challenged with BSA under aerobic environment generated a relatively large amount of malondialdehyde (MDA) as a product of lipid peroxidation. Vitamin E restored the declining of growth and inhibited MDA formation. Also in vitro lifespan of the cells challenged with BSA markedly decreased under aerobic environment as compared with that of the cells under hypoxic environment. Vitamin E did not restore the oxygen-dependent decreasing of in vitro lifespan. On the other hand, the cells cultured with serum supplemented medium grew and phased out similarly under both oxygen environment as well as the case with BSA supplemented RITC 80-7 under hypoxic environment. These results suggest that the extent of cell proliferation is controlled in part by lipid peroxidation and serum antioxidant activity is not identical from that of vitamin E.

Blood↗

In vitro proliferation and lifespan of human diploid fibroblasts in serum-free BSA-containing medium.

We have developed two serum-free chemically defined media (RITC 78-6 and RITC 80-7) that support the growth in culture of human diploid fibroblasts to the same extent as Eagle's basal medium (BME) supplemented with 10% fetal bovine serum (FBS). These two media contain modified Eagle's minimum essential medium (MEM) supplemented with nonessential amino acids, various trace metals, organic compounds and growth factors [insulin, mouse epidermal growth factor (m-EGF), transferrin and triiodothyronine (T3)]. RITC 80-7 medium differs from RITC 78-6 in that it contains thymidine, hypoxanthine, and vitamin B12 and supports the long-term serial cultivation of human diploid cultures. The addition of commercial bovine serum albumin (BSA, 5 g/liter) to the medium enhances cell growth. This effect is not observed if BSA is first delipidized, but reconstitution of BSA with certain lipids restores its ability to promote growth. BSA has an inhibitory effect on cellular attachment but this is overcome when fibronectin (FN, 10 mg/liter is added to the medium.

Cell Adhesion↗

Studies on severe hepatic damage induced by galactosamine.

Severe hepatic damage with submassive necrosis induced in rats by an intraperitoneal injection of a single dose of galactosamine hydrochloride was studied. In the severely damaged liver, the remarkable decreases of glycogen and UDPG in the damaged liver were seen. This means extreme decrease in the reserve power of glycolysis. Moreover, the activities of glucose-6-phosphatase and fructose-1,6-diphosphatase decreased. Therefore, the glucose release from liver into the blood stream decreases and the inhibition of gluconeogenesis occurs. In the damaged liver, the decrease of UTP which is essential for the synthesis of sugar moiety of polysaccharide, was seen. Further, the activities of L-glutamine: D-fructose-6-phosphate amidotransferase and UDP N-acetylglucosamine 2'-epimerase which are two key enzymes of polysaccharide synthesizing enzyme were seen to decrease remarkably. In the damaged liver, the glycoprotein fraction decreased more strikingly than the acid mucopolysaccharide fraction. Moreover, the decrease of fructose-1,6-diphosphatase activity seems also to effect on the inhibition of polysaccharide synthesis. In these respects, in the severe hepatic damage, the synthesis of glycoprotein which is essential for liver cell seems to be inhibited.

Alanine Transaminase↗

The effects of vitamin E on the indicator enzymes of organella membranes in the injured liver.

Acute and chronic liver damage was caused by the administration of either galactosamine or carbon tetrachloride. Consequently, the rats with damaged livers were killed after vitamin E was administered. The livers were removed and were homogenated. Indicator enzymes (5'-nucleotidase, arylsulfatase, cytochrome C oxidase and glucose-6-phosphatase) of organella membranes were measured in the homogenates of the normal and damaged livers. The effects of vitamin E resulted in the stabilizing of the impaired membranes of plasma, lysosome, mitochondria and microsome; (1) the abnormal decrease of 5'-nucleotidase activity and glucose-6-phosphatase activity, and the abnormal increase of arylsulfatase activity, which induced galactosamine or carbon tetrachloride, and (2) the abnormal decrease of cytochrome C oxidase activity induced by galactosamine- HCl, were normalized.

5'-Nucleotidase↗

A polyhydric phenol sulfokinase and chronic liver injury.

The sulfokinase, that transfers activated sulfate from PAPS (3'-phosphoadenosine-5'-phosphosulfate) to nitrocatechol sulfate was studied. 1. It is thought that the enzyme plays an important role in detoxication by the sulfation of polyhydric phenols in liver. 2. The enzyme had an optimum at pH 8.0 in Tris-acetate buffer. Km was 0.105 x 10(-3)M. The rate of conjugation was linear within 1 min. 3. The main distribution of the sulfokinase was found in the liver, lungs, spleen and various other organs in the rat. The activity of the enzyme in rat liver was the highest in soluble fraction. In chronic hepatic injury caused by carbon tetrachloride injection, the activity of the enzyme gradually decreased to below about one half of the control value.

Animals↗

Abnormal 99mTc-PIPIDA scans mistaken for common duct obstruction.

99mTc-PIPIDA scans were obtained in three patients with acute abdominal pain. The appearance of the scans suggested partial common duct obstruction. Two patients underwent surgery. One had acute appendicitis and the second had infarction of the distal ileum. In both cases, the gallbladder and biliary tract were normal. The third patient had been treated with morphine, which is known to increase biliary tract pressure and may cause contraction of the sphincter of Oddi. An ultrasound study of the gallbladder was normal and all symptoms resolved within 24 hours. Subsequently, three additional patients without biliary disease have been seen who had similar hepatobiliary scans. All three had received meperidine prior to the study. It is concluded that acute abdominal disease or the administration of morphine sulfate or meperidine can result in a scan pattern suggesting partial distal common duct obstruction in the absence of gallbladder or biliary tract disease.

Abdomen, Acute↗

Representation of T cell functions in liver bearing hepatocellular carcinoma.

Thymus-derived cells (T cells) were stained by the immunofluorescent technique, and found to be predominate around the cancer cell nests, in the interstitium, and in the lumen of the sinusoid of the liver bearing hepatocellular carcinoma (hepatoma). The marked T cell predominance in the liver obtained at autopsy in 19 of 13 patients with hepatoma indicates that specific T cell-mediated immunity may be maintained even in the terminal stage of cancer in these patients.

Carcinoma, Hepatocellular↗

Diagonal abdominothoracic incision as an approach to carcinoma of the cardia and upper gastric region.

An operative technique consisting of a diagonal epigastric incision extending to the left chest wall and severing the inner side of diaphragm adjacent to the pericardium to the hiatus is introduced. This technique was successfully used in 16 cases and the present surgical approach facilitates frontal visualization of the lower esophagus without disruption of the circulatory system. Furthermore, a sufficiently large operative field is obtained and radical dissection of cardia and upper gastric region or combined resection of infiltrated adjacent organs is facilitated. Postoperative recovery of pulmonary function in terms of PaO2 and PaCO2 was similar to that of patients who had received an upper median incision. We found no postoperative complications peculiar to the operative technique introduced here in any of the 16 patients.

Adult↗

The effect of metal complex of thyrotropin-releasing hormone on locomotor activity of neonatal chicken.

Neonatal chickens were injected intraventricularly with Ni(II), Pd(II), Cu(II) or Zn(II) complex of TRH and the potencies of stimulating locomotor activity were compared with that of TRH, Ni(II)-TRH was more potent than the ligand while Pd(II)-TRH was inert. Cu(II)- and Zn(II)-TRH induced the response to the same extent of the ligand. These results indicate that the action of TRH in the CNS resulting in the locomotor hyperactivity is dependent on the tertiary conformation of molecule which is modified by chelate formation.

Animals↗