Using five different glioma cell lines, SK-MG-1, SK-MG-4, U251-MG, U251-SP, and T98, and one normal glial cell line, we performed transfection of the cells with a human interferon-β (HuIFN-β) gene by means of our novel liposomes. As a result, HuIFN-β was found in the media of all glioma cells, but not in that of normal filial cells. The level of HuIFN-β increased with incubation time until 4 days after the addition of the liposomes, and approximately 20-40IU/ml of HuIFN-β was found in the media of all glioma cells except for U251-SP cells, which produced approximately 350IU/ml of HuIFN-β. Then, the levels decreased gradually and HuIFN-β in the medium could not be detected after 9 days of cultivation. By liposome-mediated transfection of the HuIFN-β gene, remarkable growth-inhibitory effects were observed for all glioma cell lines. At 4 days of incubation the effect in all glioma cell lines exceeded that obtained with 1, 000IU/ml of exogenously added HuIFN-β.
The delivery of adriamycin (ADM) to mouse inguinal lymph nodes containing metastasized mammary adenocarcinoma cells was investigated. Tumor cells of a transplantable mammary adenocarcinoma (MM48) were implanted into a hind footpad of a mouse to produce a model of inguinal lymph node metastasis. Upon subcutaneous injection into the thigh of the mouse, ADM entrapped in sulfatideinserted liposomes (Lip-ADM) brought about much more efficient delivery of the drug than did free ADM. The administration of 8mg ADM/kg body weight of Lip-ADM resulted in a tissue concentration of 12.5μg/g tissue (23.0nmol/g tissue) in the lymph node containing metastasized cells, which value was approximately 2-fold higher than that achieved in the group administered free ADM. In accordance with the efficient delivery, Lip-ADM resulted in an increase in the growth suppression effect of the drug on the tumor as compared with free ADM. As the data indicated that the antitumor effect was significantly greater in the group receiving Lip-ADM than in the one receiving free ADM, Lip-ADM would be useful for treatment of tumor cells that have metastasized to the lymph nodes.
Females are postulated to have a higher antioxidant capacity than males, this increase thereby allowing them to live longer than males. To determine whether this heightened capacity can be attributed to the difference in tissue levels of antioxidant enzymes, we investigated age-and sex-related differences in four antioxidant enzymes in developing rat livers. Female and non-castrated and castrated male rats, ages ranging from 3 to 10 weeks, were studied. Both copper zinc (CuZn) and manganese (Mn) superoxide dismutases (SOD) were assayed by specific radioimmunoassays. Body weight and liver weight were larger in non-castrated males than in females. Glutathione peroxidase activity was higher in females than in males even at 3 weeks of age, and the difference became more evident as the rats grew older. Conversely, catalase activity was higher in males than in females. The values of body weight, liver weight, glutathione peroxidase, and catalase in castrated males were between those of non-castrated males and females, suggesting a significant contribution of endogenous sex hormones to these changes. CuZnSOD increased during maturation in both sexes, while MnSOD did not. There was no significant sex-related difference in SODs. Possible physiological consequence of the relative richness of glutathione peroxidase in females was discussed.
Preventive effects of whey mineral concentrate which contained most of the milk minerals and low molecular weight whey protein on the development of hypertension in spontaneously hypertensive rats (SHR) were investigated. SHR after weaning were fed the experimental regimen (whey mineral diet or control diet) and maintained on these diets for approx. 10 weeks. A significant inhibition of development of hypertension was observed in the 4th week with male SHR fed the whey mineral diet compared with sex-matched SHR fed the control diet supplemented with a NaCl equivalent. The decrease in blood pressure became more pronounced as the period proceeded. The average blood pressure in male SHR at the end of the experiment was 213mmHg (whey mineral group) and 236mmHg in the control group. A similar result was obtained with female SHR. Accompanying attenuation of blood pressure, urinary excretion of Na and retention of Ca were enhanced by ingestion of the whey mineral concentrate. Blood pressure correlated inversely with urinary Na excretion (r=-0.62), and positively with urinary Ca excretion (r=0.78). Which factor in whey mineral concentrate mainly contributes to these effects, remains unclarified.
Acid lipase (AL) activity of mixed mononuclear leukocytes from cholesterol-fed rabbits exhibited reduced values when compared with that of normolipidemic rabbits. The observed suppression of the AL activity was reversed commensurate with a fall in the plasma concentrations of cholesterol and lipid peroxides (LPO) after the rabbits were returned to a basal diet. The AL activity was negatively correlated with both plasma cholesterol and LPO levels in rabbits. This reversible inhibition was caused by apo-B-carrying lipoproteins from the hypercholesterolemic rabbits, and protective effects were produced by preincubation of lipoproteins with anti apo-B serum. The increase in plasma LPO in the hypercholesterolemic rabbits suggests that the observed reversible inhibition of the AL activity might be due to an increase in free radicals produced in the process of lipid peroxidation in the hypercholesterolemic state. The current findings also suggest that, through the combined effects of suppression of lysosomal hydrolysis and stimulation of microsomal synthesis of esterified cholesterol, β-migrating very low density lipoprotein in cholesterol-fed rabbits accelerates hypercholesterolemia and causes accumulation of esterified cholesterol in cells.
Earlier studies in rats showed a reduced skin collagen content and maturity in riboflavin deficiency. To determine whether corneal collagen maturity has any role to play in the etiology of cataract formation in riboflavin deficiency, we measured the effect of this deficiency on total and salt-soluble collagen in the rat cornea. Total collagen content of bone was also determined since this tissue contains the highest amount of collagen in the body. Neither bone collagen level, corneal collagen content, nor salt-solubility of collagen were affected thus suggesting tissue specificity with regard to the effect of riboflavin deficiency on collagen metabolism.
To determine whether an oxidant-antioxidant imbalance exists in the non-genetic obese model, we induced obesity in 3-week-old female ICR mice by gold-thioglucose administration, and the lipid peroxide level and activities of antioxidant enzymes were measured in the plasma, liver, heart, and skeletal muscle. Two types of superoxide dismutase were assayed by radioimmunoassays. Lipid peroxide was estimated from fluorimetric measurement of thiobarbituric acid-reactive substances (TBARS). The plasma levels of both cholesterol (Chol) and triacylglycerol (TG) and liver TG content were increased in the obese mice. The superoxide dismutases were unaltered, while the activities of both glutathione peroxidase and catalase in the obese liver and heart were decreased. Lipid peroxide levels were unaltered in the obese liver and heart, decreased in the skeletal muscle, and increased in the plasma. The body weight correlated positively with the liver weight, heart weight, liver TG, liver Chol, plasma TG, plasma Chol, and plasma TBARS, and inversely with the tissue levels of some of the antioxidant enzymes and TBARS. The tissue levels of the antioxidant enzymes and TBARS had a general tendency to decrease in the obese animals. These results suggest that oxidative stress is enhanced only in the plasma of the obese mice and not in any of the tissues studied here.
After reexamining the validity of our EIA method for human pancreatic secretory trypsin inhibitor (PSTI), we measured PSTI levels in sera of patients with various diseases. Patients with acute pancreatitis or chronic disease during recrudescence showed an elevated PSTI level in their blood circulation, whereas patients with chronic pancreatitis during remission showed values within the normal range. Alpha-amylase activity in serum, one of the important markers used in the diagnosis of pancreatic diseases, was not meaningfully correlated with PSTI level. Patients suffering from various tumors also showed an elevated level of serum PSTI. A curative resection of the pancreas decreased the serum PSTI level of the patient to below one half of the pre-operation value, indicating that PSTI in the circulation originated mostly from the pancreas. However, patients having had other tissues resected showed a transient elevation of PSTI levels in their sera. From these results, PSTI in the circulation would appear to be one of the acute-phase reactants delivered from unclarified tissue(s) and/or organ(s).
We compared the activities in serum of 12 kinds of proteases including renin, angiotensin-converting enzyme, aminopeptidases, kallikrein, and other endopeptidases, between control subjects and patients with essential hypertension. In the patients, the activity of angiotensin-converting enzyme was increased by more than two times, although the activities of most of other proteases were significantly decreased, when compared with the age-matched controls. A multivariate study using discriminant function analysis suggested that angiotensin-converting enzyme plays an important role in the protease changes in the patients. The results altogether indicate that the pathogenesis of essential hypertension is closely related to an imbalance between vasoconstrictive and vasodilatative peptides such as angiotensins and kinins.