Pharmacokinetics and biologic activities of human native and asialointerferon-beta s

Glycoproteins are metabolized through an asialoglycoprotein metabolic pathway in vivo. They are desialylated and taken up by the liver via an asialoglycoprotein receptor. Fibroblast-derived natural human interferon-beta is a glycoprotein having a single asparagine-linked sugar chain. Although natural human interferon-beta may also be metabolized through this pathway, there is very little information about the biologic features of human asialointerferon-beta. We evaluated the pharmacokinetics and biologic activities of human native and asialointerferon-beta s. After intravenous administration to rabbits, human asialointerferon-beta was cleared from the blood circulation faster than the human native interferon-beta. More asialoprotein was distributed to the liver than the native type, but it induced less 2'5'-oligoadenylate synthetase. The human asialointerferon-beta had less activity than the human native interferon-beta on cell growth inhibition and 2'5'-oligoadenylate synthetase induction in Hep-G2 and HuH6 human hepatoblastoma cells. Southern blotting using a hepatitis B virus-transfected HuH6 cell line, HB611, revealed that the inhibition of hepatitis B virus DNA replication by the asialoprotein was weaker than that by the native protein. The results showed that the different effects exerted by the human native and asialointerferon-beta s may be a result of recognition of the sugar chains by rabbit hepatocytes or by human hepatoblastoma cells. The results also suggested that the terminal sialic acid of the sugar chains in natural human interferon-beta significantly affects its pharmacokinetics and biologic activities.

Carbohydrate-dependent biological activities of glycosylated human interferon-beta on human hepatoblastoma cells in vitro

To evaluate the relationship between the sugar chain structure and biological activity, fibroblast-derived glycosylated human interferon-beta, Chinese hamster ovary cell-derived glycosylated recombinant human interferon-beta and Escherichia coli-derived unglycosylated recombinant human interferon-beta were evaluated using human hepatoblastoma cells in vitro. Native fibroblast interferon-beta expressed more cell-growth inhibitory action, 2'5'-oligoadenylate synthetase induction, and the inhibition of hepatitis B virus DNA replication than its asialoform and two recombinant interferon-betas. These results showed that the sugar chain structure of human interferon-beta affects its biological activity on human hepatoblastoma cells.

Cryostat sectioning of formalin-fixed brain: further attempt to improve section quality by previous infiltration with O.C.T. compound

We previously reported that in non-brain and formalin-fixed specimens, one can obtain frozen sections of markedly improved quality not only by supporting specimens with O.C.T. compound as usually done, but by infiltrating them with the medium prior to embedding. In the present paper we show that this technic also proved to be quite effective in the cryosectioning of brain tissues, which so far has been difficult because of the liability of sections to shattering, particularly when one attempts to obtain a thick section. The present paper also discusses about the reason why sectioning is improved by the procedure, and aims to establish the optimal temperature for cryostat sectioning in relation to section thickness.

[Case report of toxic shock-like syndrome due to group A streptococcal infection]

A case of streptococcal toxic shock like syndrome occurring in a 44-year-old previously healthy Japanese male is reported. He initially had a sore throat, low grade fever, diarrhea and mild pains in a lower extremities. Shortly thereafter, he rapidly developed a high fever, profound hypotension, multifocal epidermal necrosis, and sever purulent fasciitis and myositis in both lower extremities, which required above knee amputation of both legs. He later developed disseminated intravascular coagulopathy, adult respiratory distress syndrome, acute renal failure, coma and necrotizing inflammation of both arms and external genitalia despite treatment. He died on the 13th hospital day. Streptococcus pyogenes was isolated from the necrotic muscles and right knee joint. The organism was typed as M3, T3, was sensitive to penicillins, and was found to be producing streptococcal pyogenic exotoxin A in vitro. This is the first case report of streptococcal toxic shock like syndrome in Japan.

Pharmacokinetic properties of recombinant feline interferon and its stimulatory effect on 2',5'-oligoadenylate synthetase activity in the cat

The pharmacokinetic behavior of recombinant feline interferon produced in silkworm infected with recombinant baculovirus harboring cDNA coding for feline interferon was studied in vivo in cats. The decreasing profile of the serum interferon level after intravenous administration was fitted to a two-compartment model. The half-times of the first phase (distribution phase) and second phase (metabolic phase) were 5.0 +/- 0.5 min and 31 +/- 5 min, respectively. In the whole body autoradiogram, at 15 min after the administration, the highest radioactivity was observed in urine in the bladder, and predominant radioactivity in the kidneys, liver, thyroid gland and spleen. Almost no radioactivity was detected in the brain or fat. Three hr after administration, the highest radioactivity was recorded in the thyroid gland, urine in the bladder, intestinal contents, and gastric mucous membrane. The data obtained in this study suggest that recombinant feline interferon has similar pharmacokinetic properties to human interferons and that it is distributed primarily in the liver and kidneys, is catabolized rapidly mainly in the kidneys, and is excreted in the urine without residual accumulation in the body. It was confirmed that 2',5'-oligoadenylate synthetase activity was increased by the interferon in vivo for 3 days after an intravenous bolus injection in cats.

Procedure for evaluating changes in respiratory symptoms of experimentally asthma-induced guinea pigs by a personal computer

An automated system was developed for evaluating changes in respiratory symptoms in guinea pigs over a long period with a personal computer. The data on breathing curves obtained with a body plethysmograph were analyzed to determine respiratory rate, expiration/inspiration ratio, ventilation ratio, and other parameters. With this system, respiratory changes in guinea pigs, such as increase or decrease of respiratory rate, expiration/inspiration ratio, and ventilation ratio, and death of animals could be easily observed. Investigation of delayed respiratory response to Candida albicans in sensitized guinea pigs and of the effects of SO2 or NO2 exposures on its response was carried out using this system. Respiratory changes in delayed respiratory response were mostly increased respiration rate and succeeding expiratory prolongation being noted just before death. In the influences of SO2 or NO2 exposure on delayed respiratory response, increase of respiratory rate in NO2 and expiratory and inspiratory prolongation in SO2 were found. This system should prove useful for evaluating changes in respiratory symptoms due to toxic agents, medicines, and air pollutants in small animals.

Identification of 1-alkyl-2-acyl-3-(2',3'-diacylglycerol)glycerols, a new type of lipid class, in harderian gland tumors of mice

A new class of alkyl glycerolipids, 1-alkyl-2-acyl-3-(2',3'-diacylglycerol)glycerols, was identified in lipid extracts prepared from harderian gland tumors of mice. After saponification, this lipid class yielded 1-alkyl-3-(1'-glycerol)glycerols. Identification was based on mass spectrometry, proton nuclear magnetic resonance spectroscopy, infrared spectroscopy, and chromatography of various derivatives and appropriate standards that were synthesized. The alkyl moieties of this unique lipid class consisted of saturated aliphatic chains with chain lengths of 14 to 20 carbon atoms. The acyl moieties were mostly saturated and monounsaturated aliphatic chains ranging from 14 to 24 carbon atoms. The alkyl and acyl moieties of 1-alkyl-2-acyl-3-(2',3'-diacylglycerol)glycerols were similar to those of alkyldiacylglycerols present in the same tissue, except for the presence of monounsaturated alkyl moieties in the latter. 1-Alkyl-2-acyl-3-(2', 3'-diacylglycerol)glycerols were only found in trace amounts in the normal harderian glands of mice. The total quantity of the alkyl and acyl moieties with a chain length greater than 20 carbon atoms in the alkyldiacylglycerols from tumors were considerably lower than those found in normal harderian glands of mice. This is the first report of the presence of bisglyceryl ether lipids in mammalian tissue; its unique chemical structure is consistent with the type of ether-linked lipid products that could be synthesized in the reaction catalyzed by alkyldihydroxyacetone-P synthase.

Biotransformation of nitric oxide

Previous investigations into the health effects of nitrogen oxides (NOx) have mostly been conducted with special reference to nitrogen dioxide (NO2) and its direct effects on the respiratory system, while the study of nitric oxide (NO) has been disregarded. We carried out a study on NO by exposing rats and mice to 15NO or administering 15N-nitrite and 15N-nitrate to these animals by IP injection in order to elucidate the metabolic fate of NO. The results of our study and previous findings led us to assume that the major metabolic path of inhaled NO is as follows: inhaled NO reacts with hemoglobin, forming nitrosyl-hemoglobin (NOHb), and from NOHb, nitrite (NO2-) and nitrate (NO3-) are generated. Major quantities of NO3- are discharged into the urine and a certain amount is discharged into the oral cavity through the salivary glands and transformed to NO2-. Part of this NO2- is converted to N2 gas in the stomach. Nitrate in the intestine is partly reduced to ammonia (NH3) through NO2-, reabsorbed into the body, and converted to urea. Most of the metabolites of inhaled NO are excreted rapidly from the body within 48 hr.

[Pharmacokinetics of human fibroblast interferon in rats]

Pharmacokinetic behaviors of human fibroblast interferon (HuIFN-beta) administered intravenously to rats were examined. After intravenous injection, plasma interferon level decreased in a biexponential fashion having the half-times of 15 min and 120 min respectively. Distribution levels of HuIFN-beta in the tissues at 30 min, though the actual concentrations were less than that of plasma, were observed according to the following order; kidney greater than adrenal greater than lung greater than spleen greater than liver greater than testis. Small amounts of HuIFN-beta were also detected in the thoracic lymph and bile but no HuIFN-beta was found in urine. The in vitro study indicated that the stability of HuIFN-beta was different in each tissue homogenates and body fluids. From the results obtained, we concluded that HuIFN-beta exhibited a low distributional character to the tissues when administered intravenously. It was also suggested that the kidney and the liver were the main catabolic sites of HuIFN-beta.

Different pharmacokinetics between natural and recombinant human interferon beta in rabbits

The pharmacokinetic behavior of recombinant (r) HuIFN-beta was compared with that of fibroblast-derived HuIFN-beta in rabbits using a pharmacokinetic model analysis with a computer curve-fitting. The observed data were in good agreement with a two-compartment open model in intravenous experiment, and with a one-compartment open model in intramuscular and continuous infusion experiments. Although the parameters of elimination phase (beta, Kel or K10) were almost the same in both IFNs, there were significant differences for the parameters (alpha, K12, K21, V1, V2, Vdss) of distribution phase in intravenous experiment and for the parameter (Vd) of the steady-state level in continuous infusion experiment. These results indicate that rHuIFN-beta has a larger distribution volume and a higher distribution rate from the central compartment to the peripheral. The serum levels in intramuscular experiment represented so-called flip-flop type of kinetics. Although the absorption rate from the injection site to the blood circulation was similar in both IFNs, the availability of rHuIFN-beta was higher than that of fibroblast-derived HuIFN-beta. These results suggest that the deficiency of carbohydrate moiety conjugated with IFN molecule may influence the distribution property in vivo.

Biotransformation of nitric oxide, nitrite and nitrate

Biotransformation of NO, nitrite and nitrate was investigated in rats and mice in a 15NO inhalation experiment and intraperitoneal injection experiments of 15N-nitrite and 15N-nitrate, and the following results were obtained: (1) Rats were forced to inhale 15NO (145 ppm, 123 minutes) or were given an intraperitoneal injection of 15N-nitrite (2 mg animal-1 as 15N) or 15N-nitrate (2mg animal-1 as 15N), and determination of 15N recovery in urine was made up to 48 h later. The results were 55, 53 and 78% of the inhaled or injected 15N, respectively. (2) 15N-nitrate in the urine was converted into a 6-nitro derivative of 3,4-xylenol and its identification and quantitative determination were made by the GC-MS method. As to 15N-urea in the urine, identification and quantitative determination were made by the urease method. 15N was present in the urine of rats after 15NO inhalation in the form of NO3- and urea. 75 and 24% respectively. In the urine of rats injected with 15N-nitrite, about 20% of unidentified 15N-compounds not discovered in the inhalation experiment was found. The content of 15N-urea in the urine after injection with 15N-nitrate was lower than that after injection with 15N-nitrite. (3) When 15N-nitrite (0.617 mg animal-1 as 15N) was injected intraperitoneally in mice, 60.7, 7.8 and 0.3% of the injected 15N were found in the urine, feces and exhaled gas (NO, NO2 and NH3 in the gas were caught) up to 48 h after injection respectively, and 1.6% was found in the body 48 h after injection, but the remaining 30% of 15N could not be recovered.

Antitumor effect of palmitoleic acid on Ehrlich ascites tumor

Palmitoleic acid (PLOA) markedly prolonged the survival time of mice bearing Ehrlich ascites tumor at doses of 37.5-150 mg/kg/day X 10, but the antitumor activity of oleic acid (OA) was weaker than that of PLOA. The total lipid and phospholipid contents in the tumor cells treated with PLOA were significantly decreased. In addition, the fatty acid pattern of phosphatidyl choline, cholesterol esters and triglycerides from the PLOA-treated Ehrlich tumor cells differed markedly from that of the corresponding lipids from the control tumor cells.

Inhibition of acid esterase in rat liver by 4,4'-diethylamino-ethoxyhexestrol

The effect of 4,4'-diethylamino-ethoxyhexestrol (DH) on acid esterase in rat liver was studied in vivo and in vitro. The acid esterase activity in the livers of rats treated with 0.125% DH for 1 week was found to decrease more than 60% as compared with that in untreated rats. The addition of DH to the incubation medium caused considerable inhibition of the acid esterase activity in lysosome from untreated rat liver, and the inhibition type appears to be noncompetitive. The acid lipase activity in rat liver lysosome was also inhibited by DH. Some antihistamic agents and chloroquine also inhibited the acid esterase activity in rat liver lysosome.