Correlation between lipid peroxidation and morphological manifestation of paraquat-induced lung injury in rats

Biochemical and morphological studies of rat lung were performed to determine the role of lipid peroxidation in the in vivo lung toxicity of paraquat. Two injections of 20 mg/kg paraquate were administered intraperitoneally every other day. While notable epithelial damage in the lungs was observed on the day after the second paraquat injection and progressed through the 5th day, the concentration of lipid peroxides in the rat lungs did not increase by the 3rd day after the injection. The lipid peroxide concentrations increased after the 5th day post-injection, and reached the maximum concentrations on the 7th day, when the damaged alveolar surface had been mostly repaired by regenerative pneumocytes. On the other hand, the delayed increase of lung lipid peroxides in paraquat-treated rats paralleled the increased number of macrophages in the lung, which reached maximum numbers on the 7th day. Glutathione peroxidase activity in the lungs also increased with a similar time course. Macrophages from the lungs contained a large amount of engulfed degradation products and cellular debris, and immunohistochemical study showed high glutathione peroxidase content on the 5th and 7th days. These results suggest that lipid peroxidation is a relatively late event in the in vivo paraquat-treated lung and that the delayed increase of lipid peroxides in the lungs occurs from the phagocytic activities of macrophages rather than from toxic cell injury.

Analysis of the molecular requirements for T cell recognition and activation by using Ia-containing lipid vesicles and stopped-flow fluorometry

Using Ia antigen-containing lipid vesicles, we investigated by stopped-flow fluorometry the requirements for helper T cell recognition and activation. When azobenzenearsonate-L-tyrosine (ABA-L-Tyr)-specific, I-Ak-restricted helper T cell hybridomas 2-45-12 were mixed with ABA-L-Tyr and purified I-Ak molecules on lipid vesicles, an increase of intercellular calcium ion concentration ([Ca2+]i) in the T cells were detected within 1-2s. The average increases of [Ca2+]i were not much different when the lipid vesicles were composed of dimyristoylphosphatidylcholine or of egg phosphatidylcholine, but they were dependent on the density of I-Ak molecules on the liposomes. The increase of [Ca2+]i was inhibited in the presence of anti-I-Ak monoclonal antibody 10.2.16, but not by the addition of anti-L3T4 monoclonal antibody GK1.5. However, the addition of anti-L3T4 antibody during the first 3 h of cultivation completely inhibited the T cell activation [interleukin (IL-2) production]. In our experimental system, IL-2 production was observed either when L3T4-positive T cell hybridomas 2-45-12 were stimulated with ABA-L-Tyr and Ia molecules on the vesicles in the presence of phorbol 12-myristate 13-acetate, or when L3T4-negative T cell hybridomas 3H60.12 were incubated with ABA-L-Tyr and Ia molecules on the planar membranes.(ABSTRACT TRUNCATED AT 250 WORDS)

An attempt to prepare hepatitis B virus (HBV)-free plasma by ultrafiltration using microporous regenerated cellulose hollow fiber

Hepatitis B virus (HBV) can be effectively removed from HBV-positive plasma by filtration with a Bemberg Microporous Membrane (BMM) with a pore size of 30 nm or less, however considerable amounts of macromolecular IgM and Factor VIII are trapped in the BMM. We report that HBV-free plasma with adequate amounts of all of the plasma proteins can be obtained by double filtration with a BMM with a port size of 50 nm. Thus it may be possible to remove HBV or other transfusion-associated viruses from plasma by BMM filtration with good recovery of all of the plasma components.

Experimental analysis of the spinal cord compressed by spinal metastasis

The purpose of the present study of experimental spinal metastasis, developed in rats by inoculation of tumor cells through the spinous process, was to find the factor that causes the initial damage to the cord in this disorder. In the early stage of paralysis, the degenerated posterior funiculus originated from a small hemorrhagic area in the posterior column of the involved cord. Using the scanning electron microscope, the hemorrhage was found to be from the intrinsic vein, resulting from the disturbance of venous drainage in the compressed portion. In the early stage of compression, extravasation of horseradish peroxidase was observed in the white matter, but histologic degeneration was not. A hemorrhage existed wherever degeneration of the funiculus was observed. Therefore, the trigger to induce the initial damage on the cord in spinal metastasis was not likely to be vasogenic edema, but instead the intrinsic venous hemorrhage.

Exposure level monitor of a carcinogenic glutamic acid pyrolysis product in rabbits

In order to determine a suitable indicator for estimating the exposure levels of the dietary carcinogen 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), a carcinogenic glutamic acid pyrolysis product, the levels of Glu-P-1 bound to blood components were monitored for 8 weeks by a high-performance liquid chromatography method after the dietary carcinogen was administered as single oral doses (0.2-50 mg) to rabbits. In all rabbits dosed with Glu-P-1, Glu-P-1 in erythrocytes was detectable even on day 42 after administration. Glu-P-1 in plasma disappeared faster than did Glu-P-1 in erythrocytes. Glu-P-1 levels in rabbit hemoglobin were linearly related to administered doses at all points of time investigated. The results suggest that Glu-P-1 covalently bound to hemoglobin is very suitable for monitoring long-term exposure levels.

[Present and future of carcinogenic tryptophan pyrolysis products in the environment]

Food has been considered an important factor for the genesis of cancer in man, as important as cigarette smoking. Diet influences the incidence of human cancer in many ways, directly and indirectly. Various kinds of carcinogens such as polynuclear aromatic hydrocarbons, N-nitro compounds and mycotoxins have been reported to be present in various foods. During the last decade, a new series of heterocyclic amines has been isolated as potent mutagens and later shown to be potent carcinogens in animals. Among them, carcinogenic tryptophan pyrolysates have been investigated from various points of view and useful pieces of information about them have been collected. Now, it is a matter of urgency to evaluate the effects of these carcinogens on humans. From this aspect, this review describes the information about carcinogenic tryptophan pyrolysates which has been collected and also future problems, especially those the hygienist will have to solve.

Evidence that chromium is an essential factor for biological activity of low-molecular-weight, chromium-binding substance

Biologically active Low-molecular-weight, chromium-binding substance (LMCr) has been isolated from the liver of rabbits injected with potassium bicarbonate and cow's milk. This substance enhances glucose oxidation and lipogenesis from glucose in rat adipocytes [Yamamoto A. et al. (1987) Eur. J. Biochem. 165, 627-631; (1988) J. Nut. 118, 39-45]. LMCr was shown to lose its activity almost completely as an effectant of glucose metabolism when Cr was deleted under acidic conditions and separated from LMCr by EDTA-chelation and successive molecular-sieve chromatography. Reincorporation of Cr3+ into apo-LMCr resulted in 50-90% recovery of its original activity. These findings suggest that the biological activity of LMCr resides in Cr.

Suppression of GABA-induced chloride current by 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2)

The effect of a convulsive agent, 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), on the GABA-induced chloride current (ICl) in dissociated mouse sensory neurons was investigated using the whole cell clamp method. Trp-P-2 reversibly suppressed the GABA-induced ICl in a dose-dependent manner. The IC50 for Trp-P-2 on the ICl evoked by 3 microM GABA was 11.1 microM. Ro15-1788 had no effect on the suppressive action of Trp-P-2. These results suggest that the observed effect of Trp-P-2 is mediated by its action as an antagonist at GABAA receptors.

Pathological analyses on the compressed cord by the experimental spinal metastasis

The purpose of the present experimental spinal metastasis developed in rats by inoculation of Walker's cancer cells through the spinous process is to find the factor which causes the initial damage of the cord in this disorder. In the early stage of paralysis, microangiogram exhibited that the degenerated posterior funiculus originated from the small hemorrhagic area in the posterior column of the involved cord. Scanning electron microscopic findings showed that the hemorrhage was of the intrinsic vein resulting from the disturbance of venous drainage in the compressed portion. In the early stage of compression, however, vascular permeability was observed in the white matter, but histologic degeneration was not. It was concluded that the trigger to induce the initial damage on the cord in spinal metastasis was likely to be the intrinsic venous hemorrhage.

Preliminary dose finding study for subacute toxicological study of pravastatin sodium in monkeys

Pravastatin sodium was orally administered to cynomolgus monkeys at dosage levels of 50, 200 and 800 mg/kg/day for 7 successive days. Excretion of diarrhea and/or loose stool were observed in the more than 50 mg/kg dose group, but the changes are quite mild. Animals of the 800 mg/kg dose group showed vomiting, diarrhea and/or excretion of soft stool and reduction of cholesterol content in serum. In conclusion, it is estimated that the no effective level is less than 200 mg/kg because no abnormalities were observed except for only very slight excretions of diarrhea and/or loose stool, and that the effective dose is 800 mg/kg in which vomiting was observed.

Carcinogenic tryptophan pyrolysis products in airborne particles and rain water

This is the first report that carcinogenic tryptophan pyrolysis products are present in airborne particles and rain water. The airborne particles were collected from August 1988 through October 1988 at 4 locations in Japan. The amounts of 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) in the air were 0.23 +/- 0.17 pg/m3 air (mean +/- SD, n = 18) and 0.16 +/- 0.15 pg/m3 air (n = 18), respectively. Moreover, these carcinogens were detected in rain water. These results indicate that Trp-P-1 and Trp-P-2 are ubiquitous environmental components.

Subacute toxicological study in monkeys treated orally with pravastatin sodium for 5 weeks

Pravastatin sodium was administered orally to cynomolgus monkeys at dosage levels of 50, 100, 200 and 400 mg/kg/day for 5 successive weeks. Five animals of 200 mg/kg and 400 mg/kg dose groups were sacrificed during the study period, because these animals deteriorated in general condition and/or showed remarkable changes in serum biochemical examination. Pathological examination revealed hepatic and/or renal disturbance in these animals. These changes are thought to be the cause of deterioration of general condition or changes in serum biochemical examination. All other animals were terminated at the end of the study period. In the animals of the 100 mg/kg dose group, only one animal showed hepatic and renal disorder similar in nature to the changes in the animals sacrificed during the study period. No animals in the 50 mg/kg dose group showed toxic findings in any examination.

The decomposition and aggregation of rat lens protein induced by selenite in vitro and in vivo

A single subcutaneous injection of sodium selenite at the dose of 20 mumol/kg body weight induced bilateral nuclear cataracts in suckling rats. This selenite-induced cataract incidence can be increased by pretreating animals with a glutathione synthesis inhibitor. Sodium dodecyl sulfate polyacrylamide electrophoresis of urea-soluble proteins from selenite-induced cataractous lenses showed the appearance of high molecular weight aggregates and decomposed products of lens proteins. These products were found in association with the emergence of a 45 K band. Incubation of water-soluble lens proteins with selenite in vitro produced changes similar to those demonstrated in selenite-induced cataractous lenses. Furthermore, selenite induced the gradual development of opalescence and the oxidation of sulfhydryl in the lens protein solution. Therefore, we presume that the oxidation of lens protein sulfhydryl by selenite is associated with both aggregate formation and the decomposition of lens proteins, and that these changes may provide a partial explanation for the mechanism of selenite cataract.

A novel method for removal of human immunodeficiency virus: filtration with porous polymeric membranes

We propose a new method to rid solutions of a virus by using a novel regenerated multilayered structured cellulose membrane (BMM). When the filtrate of human immunodeficiency virus (HIV) preparation was obtained through BMM it showed no infectivity. Electron microscopic observation revealed that HIV was completely caught by the multilayers of the BMM. Conveniently, BMM was seldomly found to adsorb protein molecules and also to have a high filtration rate. These characteristics may have a use in the removal of other variously sized pathogenic agents from plasma.

Carcinogenic tryptophan pyrolysis products in human lens

Mutagenic and carcinogenic tryptophan pyrolysis products, 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), have been identified in human cataractous lenses, but not in young bovine lenses. The amounts of Trp-P-1 and Trp-P-2 in senile cataractous lenses were 156.34 +/- 35.63 fmol (mean +/- S.D., n = 10) and 128.27 +/- 40.45 fmol (n = 10), respectively, while those of Trp-P-1 and Trp-P-2 in diabetic cataractous lenses were 158.29 +/- 40.06 fmol (n = 10) and 150.34 +/- 23.77 fmol (n = 10), respectively. In both senile and diabetic cataractous lenses, the concentrations of Trp-P-1 and Trp-P-2 in the insoluble protein fraction (fmol mg-1 protein) were significantly higher than those in the water-soluble protein fraction. Moreover, proteinase-K treatment of lens protein before extraction with methylene chloride significantly increased the recoveries of Trp-P-1 and Trp-P-2. These results clearly indicate that carcinogenic tryptophan pyrolysis products, gamma-carboline derivatives, are present in human cataractous lenses and that these fluorescent carcinogens are significantly concentrated in the insoluble lens proteins.

Anterolateral uncoforaminotomy for cervical spondylotic monoradiculopathy

Twenty patients with cervical spondylotic monoradiculopathy treated with anterolateral uncoforaminotomy were analysed. Spondylotic spur of the level associated with radiculopathy was revealed to be continuous from the uncovertebral joint to the posterior ridge of the vertebral body in 18 patients and was observed posterolaterally in two. Anterolateral uncoforaminotomy was found to safely remove continuous type of spur, resulting in decompression of the cord-root complex, which shifted anteriorly after surgery. As a result, no neurological symptoms were observed in 19 of 20 radiculopathy patients. From our present series, it could be concluded that the most important factor in relieving neurological manifestations of this disorder is anterolateral decompression of the cord-root complex.

Surgical treatment of metastatic tumors of the spine

The goal of surgical treatment of metastatic spinal tumors is to maintain neurologic functioning without pain for the duration of the life expectancy. Of 28 patients in this series, 25 who had metastasis in the vertebral body underwent direct decompression by removal of the tumor, followed by vertebral reconstruction. A combined anterior or posterior instrumentation provided rigid spinal stability immediately after surgery. Three patients with involvement of the posterior part of the vertebra were treated by laminectomy for removal of the tumor, followed by posterior instrumentation. As a result, of nine patients who are alive with improved neurologic functions, seven have been ambulatory for an average duration of 13 months. Of 19 patients who have already died, recurrence of neurologic deficits was observed in five (26%), and 14 had no neurologic deterioration until they succumbed to the malignancy. Removal of the tumor and reconstructive surgery may be expected to produce satisfactory results.

[Study on the repeated oral administration method in infant rats]

The purpose of this study was to establish a new technique for repeated oral administration to infant rats. To determine the maximum volume which could be administered to infant rats the following amounts of the Chinese ink were given by metal gastric zonde for mice: 0.01, 0.04 and 0.08ml/g B. W. General conditions and the arrival distance of the Chinese ink in the gastro-intestinal tract were also observed in infant rats. The best way of administration to infant rats was decided as follows: infant rats were isolated from the dums for one hour before administration and held tenderly by their neck to sustain their mouth upward, then a metal gastric zonde for mice 2 cm long was inserted to their mouth and drug solution was injected slowly. From the observation of general conditions and pathological examination, the maximum volumes for single or repeated administration were considered to be 0.04ml/g B. W. and 0.01 ml/g B. W. respectively. Daily oral administration of 0.1ml/g B. W. of distilled water, 1% CMC solution or 1% tragacantha gum suspension for 44 days caused no effects in infant rats when administration was begun 4 days after birth. These results show that the new method for administration to infant rats is useful to evaluate the toxicity or pharmacological activity of drugs.

In vitro and in vivo N-acetylation of carcinogenic glutamic acid pyrolysis products in humans

The carcinogenic glutamic acid pyrolysis products, 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) and 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), and their N-acetyl derivatives have been demonstrated to be present in human urine, bile, liver and kidney. In vitro experiments have revealed that Glu-P-1 and Glu-P-2 are N-acetylated to form N-acetyl derivatives by the cytosolic fraction from a human autopsy liver specimen. From these results our data strongly suggest that Glu-P-1 and Glu-P-2 derived from everyday foods are partially N-acetylated in human organs and that they are excreted in bile and urine with their N-acetyl derivatives. Our data also provide the first reliable evidence that humans can metabolize the carcinogenic heterocyclic amines.

Anterolateral uncoforaminotomy for cervical spondylotic myeloradiculopathy

Thirty-five patients with cervical spondylotic radiculopathy and myeloradiculopathy had anterolateral uncoforaminotomy. Spondylotic spurs associated with radiculopathy were continuous from the uncovertebral joint to the posterior ridge of the vertebral body in 33 patients and to the posteriorly bulging disc with posterolateral bony spurs in 2 patients. Anterolateral uncoforaminotomy was found safe to remove the continuous type of spur, resulting in decompression of the cord-root complex, which shifted anteriorly after surgery. The outcome was satisfactory in 19 of 20 radiculopathy patients, and in all 15 myeloradiculopathy patients. Decompression of the cord-root complex is the most important factor in relieving neurologic manifestations of cervical spondylosis.

Analysis of human plasma as an exposure level monitor for carcinogenic tryptophan pyrolysis products

A high-performance liquid chromatography method for detecting 3-amino-1,4- dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) in human plasma was developed. Plasma samples of 10 normal subjects were examined. Trp-P-1 and Trp-P-2, carcinogenic tryptophan pyrolysis products, were detected in all specimens, and the concentrations of Trp-P-1 and Trp-P-2 in plasma were 68.31 +/- 24.03 fmoles/ml (mean +/- S.D., n = 10) and 18.79 +/- 4.99 fmoles/ml, respectively. Our results suggest that plasma levels of carcinogenic tryptophan pyrolysis products may be useful indicators for estimating the exposure levels of the dietary carcinogens.

Ultrastructural study of a perineurioma

A case of soft tissue tumor in the left brachialis muscle of a 49-year-old Japanese female patient was studied by electron microscopy. The tumor was diagnosed as intramuscular myxoma by light microscopy, but electron microscopic observation revealed that the tumor almost entirely consisted of cells similar to normal perineurial cells. The tumor cells possessed long, slender cytoplasmic processes covered by well-developed but discontinuous basal laminae, clusters of pinocytotic vesicles, and infrequent intercellular junctions. Perineurial cells have also been observed in other peripheral nerve lesions: neurofibromas, nerve sheath myxomas, and localized hypertrophic neuropathies. However, the term "perineurioma" or "perineurial cell tumor" should be reserved for discrete tumorous masses that are almost entirely composed of perineurial cells without evidence of residual axons, Schwann cells, fibroblasts, or tactile corpusclelike structures. Perineurioma may represent a third category of peripheral nerve sheath tumors, ultrastructurally distinct from schwannomas and neurofibromas.