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Biomedical subjects

S Manabe

Publications and source records attributed to S Manabe.

At least 109 records · Page 6Linked to original sources
PubMed1989

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.

Adult↗
PubMed1989

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.

Angiography↗
PubMed1989

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.

Cells, Cultured↗
PubMed1989

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.

Animals↗
PubMed1989

[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.

Carbolines↗
PubMed1989

[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.

Administration, Oral↗
PubMed1989

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.

Administration, Oral↗
PubMed1989

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.

Administration, Oral↗
PubMed1989

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.

Animals↗
PubMed1989

[The process of developing and improving the analytical method of benzene in organic solvents for household use: interlaboratory collaborative study].

A method for the determination of benzene in spot remover using gas chromatography (GC) and high-performance liquid chromatography (HPLC) was developed. The method was evaluated by collaborative study. There are various types of household products containing organic solvents. The collaborative study clarified that a clean-up procedure is necessary for the analysis of products other than spot remover. Thus, our improved method adopted the head space method in GC and microdiffusion method in HPLC as the clean-up procedure.

Benzene↗
PubMed1989

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.

Adult↗
PubMed1988

Properties of cutaneous acetyltransferase catalyzing N- and O-acetylation of carcinogenic arylamines and N-hydroxyarylamine.

The role of skin for N- and O-acetylations of carcinogenic arylamine and N-hydroxyarylamine was studied in vitro. Unexpectedly high activities were observed in acetyl CoA-dependent N-acetylations of 2-aminofluorene (2-AF) and p-aminobenzoic acid (PABA) in skin cytosols of hamsters. The specific activity for 2-AF (4.52 nmoles/mg protein per min) was largely the same as that of rat liver cytosols. The cutaneous cytosols also catalyzed N,N-acetyltransfer reaction from N-hydroxy-4-acetylamino-biphenyl (N-OH-AABP) to 2-AF and acetyl CoA-dependent O-acetylation of 2-hydroxyamino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (N-OH-Glu-P-1), suggesting that hamster skin cytosol has enzymes similar to hepatic acetyltransferases. In addition, remarkably high correlations were observed between the skin and liver in the activities for N-acetylations of PABA and 2-AF. In a colony of Syrian golden hamsters a clear polymorphism was detected in the cutaneous N-acetylations of PABA and 2-AF. These animals were divided into three groups according to their activities: rapid, intermediate and slow acetylators. On the other hand, the acetylating activities in the skin and liver of these three groups showed monomorphic distribution with N-OH-AABP-dependent N,N-acetyltransfer of 2-AF and acetyl CoA-dependent O-acetylation of N-OH-Glu-P-1. These results, together with the detection of N-acetylating activity in the skin of other experimental animals and humans, suggest that skin may play an important role in the metabolism of aromatic amines and that the cutaneous acetylation in hamsters may be under the common genetic control which regulates the individual difference in the hepatic activities.

Acetylation↗
PubMed1988

Detection of carcinogenic glutamic acid pyrolysis products in Worcestershire sauce by high-performance liquid chromatography.

Commercially available Worcestershire sauce was analyzed for mutagenic and carcinogenic glutamic acid pyrolysis products using high-performance liquid chromatography. These carcinogenic heterocyclic amines were found to be present in all brands of Worcestershire sauce analyzed. The identity of the carcinogens was confirmed by spectrometric analyses and the SOS umu-test. The concentrations of 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) and 2-amino-dipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2) in the Worcestershire sauce were 695 +/- 329 pmol/liter (mean +/- SD, n = 5) and 1,839 +/- 1,321 pmol/liter (n = 5), respectively.

Amines↗
PubMed1988

Detection of N-acetyl derivative of 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) in Glu-P-1-injected rats.

In order to confirm in vivo N-acetylation of 2-amino-6-methyl-dipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) in rats, we developed a new high-performance liquid chromatography (HPLC) method for detecting the N-acetyl derivative of Glu-P-1 in animal organs. Using this method, N-acetyl-Glu-P-1 was detected in rat liver, kidney and intestinal contents 6 h after intraperitoneal injection of Glu-P-1. This fact provides evidence to support in vivo N-acetylation of Glu-P-1 in rats.

Acetylation↗
PubMed1988

Evaluation of a proposed standard reporting system for preoperative angiograms in infrainguinal bypass procedures: angiographic correlates of measured runoff resistance.

Preoperative angiography is widely used to estimate runoff before peripheral vascular bypass surgery. The Ad Hoc Committee on Reporting Standards for the Society for Vascular Surgery and the International Society for Cardiovascular Surgery recently proposed an angiographic scoring system that grades the quality of vessels distal to the proposed bypass site and calculates an overall runoff score after adjusting each vessel score by an arbitrary weighting factor. We compared this score with intraoperatively measured runoff resistance in 67 patients undergoing infrainguinal bypass. Correlation between overall runoff score and measured resistance varied with the distal bypass site and was reasonably predictive for femoropopliteal above-knee bypasses (r = 0.67, p = 0.004, N = 17) and femoroposterior tibial bypasses (r = 0.73, p = 0.03, N = 9), but not for femoropopliteal below-knee (r = 0.05, p = 0.76, N = 34) or femoroperoneal (r = 0.57, p = 0.18, N = 7) bypasses. When multiple linear regression was used to calculate the weighting factors (rather than using arbitrarily assigned factors), the correlation between overall angiogram score and measured resistance improved substantially for femoropopliteal above-knee (r = 0.85, p = 0.00006), femoropopliteal below-knee (r = 0.50, p = 0.03) and femoroperoneal (r = 0.83, p = 0.02) bypasses. Correlation for the entire group of 67 patients improved from r = 0.30 (p = 0.02) to r = 0.64 (p = 0.0001). We conclude that the committee's scoring system correlates with measured runoff resistance but can be improved by the use of multiple linear regression to calculate weighting factors for each vessel in the outflow tract.

Anastomosis, Surgical↗