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Biomedical subjects

K Tsuchiya

Publications and source records attributed to K Tsuchiya.

At least 631 records · Page 35Linked to original sources

Absorption, distribution and excretion of cefmenoxime (SCE-1365), a novel broad-spectrum cephalosporin, in mice, rats, rabbits and dogs.

The levels of cefmenoxime (SCE-1365) [7 beta-[2-(2-aminothiazol-4-yl)-[Z]-2-methoxyiminoacetamido]-3-[(1-methyl-1H-tetr azol-5-yl)thiomethyl]ceph-3-em-4-carboxylic acid] and cefotaxime [7 beta-[2-(2-aminothiazol-4-yl)-[Z]-2-methoxyiminoacetamido]-3-acetoxymethyl-ceph -3-em-4-carboxylic acid] in plasma and tissues, and the excretion in urine and bile of experimental animals were compared. A single dose of 20 mg/kg of cephalosporins was administered subcutaneously to mice and intramuscularly to rats, rabbits and dogs. The cefmenoxime and cefotaxime levels in plasma and tissues reached a peak in 15 approximately 30 minutes after administration. The cefmenoxime levels in plasma were slightly higher than that of cefmenoxime in rats and slightly lower in mice, rabbits and dogs. The tissue levels of cefmenoxime, however, were much higher than those of cefotaxime. In mice and rats, cefmenoxime was distributed in high concentration to various tissues in the descending order of the kidney, plasma, liver, lung, spleen and brain; in rabbits, kidney, plasma, lung, liver, spleen and brain; and in dogs, kidney, liver, plasma, lung, spleen and brain. The plasma and tissue levels of cefmenoxime persisted much longer than those of cefotaxime. Both cephalosporins were excreted principally in the urine. A high biliary excretion of cefmenoxime was observed in rats and dogs. In the specimens from animals given cefotaxime, deacetylcefotaxime was found in various amounts.

Absorption↗

Serum and urinary beta-2-microglobulin among cadmium-exposed workers.

The effect of ten years' cadmium [Cd] exposure was investigated among a total of 18 workers [ten with previous heavy exposure, three with recent lower exposure and five control workers] by comparing indicators of previous exposure [blood and urinary Cd and beta 2-M] with clinical estimates of renal tubular function. The ten workers still excreted higher concentration of Cd than did the other three workers with low exposure, even after cessation of exposure. Estimates of renal function indicated that most workers among the ten and the three workers did not always exhibit dysfunction. Elevated blood Cd was significantly correlated with elevated serum beta 2-M. The study demonstrated that increased beta 2-M in the urine is not necessarily due to tubular impairment, but may be the result of the increased beta 2-M in plasma exceeding the renal threshold.

Albuminuria↗

Mauritius type black rats with peculiar karyotypes derived from Robertsonian fission of small metacentrics.

All seventeen black rats collected from Mauritius Island were characterized by having many extra small acrocentric autosomes. Their basic karyotype was of Oceanian type, because of the presence of the large metacentric M1 and M2 pairs, but chromosome numbers in 13 specimens among them were 42, those of 3 specimens 43, and those of the remaining one specimen 44. Although the Oceanian type rat had 2 small acrocentric autosomes (pair no. 13), 16 Mauritius rats had 10 small acrocentrics, and the remaining one had 8 small acrocentrics. Comparative karyotype analysis between Oceanian and Mauritius type rats showed that the extra small acrocentrics found in Mauritius rats were due to Robertsonian fission of small metacentric pairs no. 14 and 18 of the original Oceanian type rat. Only one rat with 8 small acrocentrics showed the heteromorphic pair no. 18 consisting of one metacentric and two acrocentrics. The large metacentric M1 chromosome in 13 of 17 rats examined showed homologous pair, but two of them were heteromorphic by involving one metacentric M1 and two acrocentrics. In the remaining two rats M1 chromosome was not observed, but acrocentric pairs no. 4 and 7 were included. These acrocentrics were also suggested to be originated from Robertsonian fission of the large metacentric M1 chromosome. Robertsonian fission seemed to be one of the important mechanism found in karyotype evolution.

Animals↗

Increased urinary beta 2-microglobulin in cadmium exposure: dose-effect relationship and biological significance of beta 2-microglobulin.

A study on the general population from both cadmium-polluted and control areas and on cadmium alloy workers indicates that beta 2-MG in urine is very closely correlated with aging, but it indicates an association with cadmium exposure. However, the age factor is stronger than cadmium exposre in both polluted and control areas among persons without clinical proteinuria. On the other hand, cadmium exposure is most likely correlated with beta 2-MG even in nonpolluted areas. Thus it seems that there is no noneffect level of cadmium dose in affecting the elevation of beta 2-MG in urine. beta 2-MG in serum indicated a very close correlation with cadmium in blood among cadmium alloy workers. This may suggest that an increase of beta 2-MG in both blood and urine in an early stage of cadmium exposure is caused by the increased level of beta 2-MG in blood, which may be a result of stimulation due to cadmium, but not necessarily by the clinical dysfunction of reabsorption of beta 2-MG in the renal.

Age Factors↗

Effects of dietary cadmium on rhesus monkeys.

Ten male rhesus monkeys, each weighing 3.5 kg, were divided into four groups of 3, 3, 2, and 2, and were fed daily with 100 g pelleted food containing 300, 30, 3, and 0 ppm cadmium, respectively. Urine samples were collected every 2 weeks and blood samples every 4 weeks. One monkey each of the 300 and 30 ppm groups was autopsied for pathological examination and tissue cadmium determination at the week 24 of the experiment; the remaining 8 animals were killed after 55 weeks. The lowest exposed group (3 ppm) did not show any specific biological response to cadmium over a period of 55 weeks. In the 30 ppm group, no significant changes were observed for up to 24 weeks, although cadmium concentration in the renal cortex and urine at 24 weeks were 300 mug/g wet weight and 18 mug/l., respectively. Plasma urea nitrogen and urine protein (quantitative determination) increased after 30 and 36 weeks. At 55 weeks of the experiment, qualitative tests were negative for low molecular weight proteinuria and glycosuria, and the results remained normal for renal and liver function tests and blood analysis, although cadmium concentrations in the renal cortex of two monkeys were 460 and 730 mug/g wet weight and those in the liver were 110 and 160 mug/g wet weight, respectively. In the highest exposure group (300 ppm), urine cadmium increased to 250 mug/l. by 11 weeks, and urine retinol-binding protein, plasma GOT, GPT, and LDH increased after 12 weeks. Proteinuria (quantitative determination), glycosuria, aminoaciduria (panaminoaciduria), and erythrocytopenia were observed after 16 weeks, when urine cadmium was 500-900 mug/l. Hypohemoglobinopathy and proteinuria (qualitative determination) were observed after 20 and 24 weeks, while cadmium concentrations in the renal cortex and the liver were 760 and 430 mug/g wet weight at 24 weeks, respectively. Slightly depressed tubular reabsorption of phosphate, increased urine beta(2)-microglobulin, increased plasma urea nitrogen, and increased plasma alpha(2)-globulin fraction (electrophoresis) were observed between 28 and 30 weeks of the experiment. Creatinine clearance and plasma cholinesterase decreased after 47 and 54 weeks, respectively. Cadmium concentrations in the renal cortex and the liver of two monkeys at 55 weeks were 350 and 580 mug/g wet weight and 410 and 630 mug/g wet weight, respectively. Pathological examinations revealed denaturation, destruction, and regeneration of the epithelial cells in renal proximal tubules, but no pathological changes in osseous tissues. Critical cadmium concentration in the renal cortex was estimated to be 380 mug/g wet weight for low molecular weight proteinuria and 470 mug/g wet weight for proteinuria, glycosuria, and aminoaciduria. Critical concentration in the liver was also estimated to be 210 mug/g wet weight. The apparent biological half-time of cadmium in monkeys at autopsied stage was calculated to be 0.66, 6.4, 5.2, and 22.4 years for the 300, 30, 3, and 0 ppm groups, respectively.

Animals↗

Immunological cross-reactivities of sulfocephalosporins.

The immunological cross-reaction among sulfocephalosporins (cefsulodin, SFC-I, SFC-II), cephaloridine, sulbenicillin, penicillin G and 7-aminocephalosporanic acid has been investigated. A specific antibody was produced in rabbits against several structurally related haptens. The sensitization was conducted with a hapten-human serum albumin conjugate, which was prepared in an alkaline solution, with Freund's complete adjuvant. A cross-reaction was claraly demonstrated between sulfocephalosporins and sulbenicillin, but not between sulfocephalosporins and cephaloridine, penicillin G or 7-aminocephalosporanic acid.

Animals↗

Arthroscopy in spontaneous osteonecrosis of the knee.

Eight knees with spontaneous osteonecrosis were investigated through arthroscopy, and in seven the intra-articular findings were rechecked at arthrotomy performed one to two weeks later. Anbormalities in the articular cartilage were observed in detail under arthroscopy that could not be seen in roentgenograms. In the early stage of osteonecrosis, flattening and fissures in the articular surfaces, with and without formation of a cartilage flap, were useful findings in choosing intra-articular surgical procedures. In the late stage, free bodies such as cartilage plates in the joint and regeneration with fibro-cartilaginous tissue over the necrotic lesion were also important in selecting surgical treatment. In addition to roentgenographic classification of developmental stages in osteonecrosis, arthroscopy is necessary in differentiating osteoarthroses, in observing the articular surface of the femoral condyles, and in determining the stage of disease when roentgenography provided insufficient information to justify intra-articular procedures such as drilling and bone grafting.

Aged↗

The effect of high tibial osteotomy on osteoarthritis of the knee. Clinical and histological observations.

High tibial osteotomies were performed on 136 osteoarthritic knees for correction of varus deformity. Before osteotomy all patients experienced moderate or severe pain, and the knees showed lateral thrust on weight-bearing. The patients were followed up for one to five years. Marked relief of pain was obtained in 112 knees, and the patients were satisfied with the result of operation in 122. These painless knees showed no lateral thrust, and in the majority the deformity had been adequately corrected, with post-operative femoro-tibial angles (standing) ranging from 165 degrees to 174 degrees. Four of 28 knees with femoro-tibial angles of 175 degrees to 179 degrees, when measured one year after operation, showed recurrence of varus deformity three years after osteotomy. Preoperative ranges of knee motion were well maintained after osteotomy even when arthrotomy had also been undertaken. Intra-articular assessment in two patients, several years after operation, showed that the most degenerated portions of the articular surface were completely covered by a fibrocartilagenous layer, with no bare bone. High tibial osteotomy is most effective in osteoarthritic knees with varus deformity, when correction is made to a femoro-tibial angle (standing) of 170 degrees (10 degrees valgus).

Adult↗