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Biomedical subjects

T Kaji

Publications and source records attributed to T Kaji.

At least 163 records · Page 9Linked to original sources
PubMed1988

The effects of cadmium, copper or zinc on formation of embryonic chick bone in tissue culture.

Femurs from 9-day-old chick embryo were cultivated for 6 days by the roller-tube method in the presence of Cd, Cu or Zn. Cd (5.0 microM and above) and Cu (2.5 microM and above) caused a decrease in collagen content of both diaphysis and epiphysis, mainly due to inhibition of collagen synthesis. In addition, Cd and Cu each showed a tendency to inhibit an increase in Ca content of diaphysis, where intraperiosteal ossification could be observed. Alkaline phosphatase (ALP) activity was decreased by Cd (5.0 microM and above) or Cu (10 microM and above) in diaphysis. On the other hand, Zn at 50 microM and above inhibited an increase in Ca content of the diaphysis with a remarkable elevation of ALP activity in the medium. At this time, Zn did not decrease the collagen content of the diaphysis so strongly. Histological observations revealed that Cd and Cu each decreased both calcified and uncalcified osteoid tissue at 2.5 microM, while Zn at 100 microM decreased calcified tissue but increased uncalcified osteoid tissue. As Zn accumulated particularly in diaphysis and deposited at the edge of calcified tissue, it was suggested that Zn inhibited calcification physicochemically. It was concluded that Cd or Cu would induce bone damage represented by osteoporosis, whereas Zn would induce osteomalacia.

Alkaline Phosphatase↗
PubMed1988

Role of zinc in protection against cadmium-induced toxicity in formation of embryonic chick bone in tissue culture.

To clarify a possible mechanism of zinc (Zn)-induced tolerance to cadmium (Cd) toxicity on bone formation, femurs from 9-day-old chick embryos were cultured for 6 days by the roller-tube method in the presence of Cd (2, 4 or 9 microM) and/or Zn (60 microM). Zn prevented a decrease in bone growth caused by Cd at 4 and 9 microM. An increase in calcium (Ca) content of diaphysis was inhibited by Zn in both the presence and absence of Cd. Histologically, Zn protected a Cd-induced degenerative change of mesenchymal cells in the periosteum and that of osteoblasts around the trabecula at each Cd level. At 60 microM Zn, Cd accumulated less in the bone at 2 microM but more at 9 microM. From these results, it was concluded that Zn prevented Cd-induced toxicity in the process of ossification except calcification in a culture system by two different mechanisms, i.e. a decreasing Cd accumulation at a low level of Cd and probably an induction of metallothionein (MT)-like protein at a high level of Cd.

Alkaline Phosphatase↗
PubMed1988

Emesis induced by cancer chemotherapeutic agents in the Suncus murinus: a new experimental model.

Acute emetic responses to seven cancer chemotherapeutic agents (adriamycin, bleomycin, cisplatin, cyclophosphamide, 5-fluorouracil, methotrexate, mitomycin C) were studied in the Suncus murinus. Intravenous injection of the drugs caused vomiting with various latency. Cisplatin-induced emesis was prevented by the pretreatment with metoclopramide or chlorpromazine but not with domperidone. These results indicate that the Suncus murinus is a useful animal for testing emetic activities of cancer chemotherapeutics and antiemetic activities of prophylactic drugs.

Animals↗
PubMed1987

[Tritium and carbon-14 concentrations around an incinerator for radioactive liquid scintillator waste].

Activity measurements of 3H and 14C in several environmental samples around the incinerator for radioactive liquid scintillator waste at the Radioisotope Center, Kyushu University were carried out to estimate their levels. It was indicated that 3H and 14C concentrations in the atmosphere at 1 m from the outlet were about 0.2% of those estimated at the outlet, respectively. At 6 m away from the outlet, 3H concentration decreased to about one twentieth of that at 1 m and 14C concentration to background level. For soils and plants, 14C concentrations showed negligibly low values. The existence of these nuclides in particle form was not confirmed. It is considered that the result of the higher 3H concentrations as compared to 14C concentrations reflects not only the difference of the waste amounts of their nuclides, but also the discharge of 3H as moisture as well as water vapor.

Carbon Radioisotopes↗
PubMed1986

A possible mechanism of cadmium-copper interaction in embryonic chick bone in tissue culture.

Femurs from 9-day-old embryo were cultured for 4 days by the roller-tube method in the presence of Cd and/or Cu. The combination of both Cd and Cu caused a significantly interactive decrease in hydroxyproline (Hyp) synthesis as well as bone growth compared with that in the presence of Cd (1.1 or 3.3 microM) or Cu (1.1 or 2.2 microM) alone. The presence of both 2.2 microM Cd and 3.3 microM Cu also showed a significantly interactive decrease in the incorporation of [3H]proline (Pro) into collagenase-digestible protein (CDP), but it showed no interactive inhibition of the hydroxylation of [3H]Pro in CDP. The two metals were also interactive with respect to the inhibition of the synthesis of protein, RNA and DNA. Culture of epiphysis in the presence of both Cd and Cu resulted in higher content of Cd and Cu compared to those cultured in Cd or Cu alone. Subcellular fractions from epiphysis cultured in Cd plus Cu contained more Cd than those cultured in Cd alone. Cu was increased in two fractions, nuclei and cytosol, following co-incubation. The cytosol from epiphysis cultured in the presence of both Cd and Cu contained more Cd in both a metallothionein (MT)-like protein and a high-molecular-weight (HM) protein than cytosol from Cd-treated bones. The amount (nmol) of Cu in the MT fraction was nearly equal to the sum of the increased amounts (nmol) of Cd in HM fraction of cytosol and particulate fractions. This indicates that some Cd in MT-like protein induced by Cd is replaced with Cu and the released Cd redistribution to HM fraction and particulate fractions. Most of the Cd in the solubilized particulate fractions was detected in the HM fraction. A marker enzyme or component in each fraction was interactively inhibited by both Cd and Cu. Therefore, the interactive inhibition of bone metabolism by both Cd and Cu in the cultured bone is at least partly due to the increase in Cd content of HM fraction of cytosol and particulate fractions.

Animals↗
PubMed1986

The synthesis of metallothionein-like protein containing zinc in liver of rat after administration of calcium and calcitonin.

Subcutaneous (s.c.) and intraperitoneal (i.p.) injection and oral administration of calcium (Ca) into rats increased Ca content of liver compared with control rats. When liver cytosol was filtered through a Sephadex G-75 column, zinc (Zn) content of metallothionein (MT)-like protein fraction was several times higher in Ca treatment than in control. Zn and copper (Cu) content of high-molecular (HM) and moderate-molecular (MM) fractions and Cu content of MT fraction was unaffected by Ca treatment. Zn in MT fraction showed two peaks in the direct-connection method of high-performance liquid chromatography to atomic absorption spectrophotometer (AAS). The retention time of these two peaks agreed with those of Zn or cadmium (Cd) in MT fraction of liver cytosol obtained from Zn- or Cd-administered rat. These results show that MT-like protein containing Zn is induced by Ca. In conditions showing a slight increase in liver Ca and a significant decrease in serum Ca by synthetic [Asu1,7] eel calcitonin (CT) injection, gel filtration of liver cytosol obtained from CT-treated rats showed a higher content of Zn and a higher radioactivity of [3H]cystine than that from control injection. This suggests that CT causes an increase in liver Ca and results in induction of MT-like protein containing Zn by Ca.

Administration, Oral↗
PubMed1986

Canada-Cronkhite syndrome associated with systemic lupus erythematosus.

A 43-year-old woman with a history of systemic lupus erythematosus manifested severe diarrhea, generalized gastrointestinal polyposis, pigmentation, and onychodystrophy, which were typical of Canada-Cronkhite syndrome. The exacerbation of systemic lupus erythematosus, presenting with hemolytic anemia and subsequently with profound proteinuria, was seen during the course of this syndrome. The patient achieved complete symptomatic remissions of both entities for more than four years following prednisolone therapy; the resolution of the gastrointestinal polyps was confirmed histologically. This case showed that this syndrome could be completely reversible in its course and that it might have an exogenous cause, as previously suggested.

Adult↗
PubMed1985

Detection of paraesophageal varices by plain films.

Plain-film findings of paraesophageal varices were investigated in 352 patients with portal hypertension. Paraesophageal varices were suggested on routine chest films in 17 cases (4.8%) and on Bucky films in 30 cases (8.3%). Plain-film findings included posterior mediastinal mass shadows, obliteration of the descending aorta, and mass density adjacent to the descending aorta appearing to be intraparenchymal (lesions in the inferior pulmonary ligament). The importance of close observation of subtle findings on plain chest films is stressed.

Esophageal and Gastric Varices↗
PubMed1984

Interaction between cadmium and copper in relation to the collagen metabolism of embryonic chick bone in tissue culture.

To investigate the interaction between Cd and Cu in relation to the content of collagen in bone, femurs obtained from 9-day-old chick embryos were cultivated with a combination of Cd and Cu concentrations of 8.9 microM and below for 4 days. When 2.23 or 4.45 microM Cd was added to the medium containing 4.45 or 8.90 microM Cu, the presence of both Cd and Cu caused a remarkable decrease in collagen synthesis compared with a decrease in collagen synthesis caused by either Cd or Cu alone. The results show that Cd and Cu caused an interactive inhibition of collagen synthesis, which was not due to an increase in collagen degradation by Cd and Cu. At concentrations showing inhibition, Cd caused an increase in Cu content and Cu caused an increase in Cd content. The increase in Cd content was mainly caused by the accumulation of Cd in bone mineral. The increase in Cu content was due to binding to metallothionein-like protein in the cytosol induced by Cd. The relationship between inhibition and the increase in both Cd and Cu was not confirmed after division of the bone into diaphysis and epiphysis. The present study showed that Cu aggravated the bone matrix damage caused by Cd.

Animals↗
PubMed1984

[The effect of maternal exercise on the fetal heart rate].

The effect of maternal exercise (the two-step test of Master) on the fetus was studied in 28 pregnant women. These subjects consisted of 5 cardiac cases, 5 cases with IUGR, 5 cases with preeclampsia and 13 normal pregnant women. Overt deceleration of the FHR was found after exercise only in 3 cardiac cases whose FHR tracings had been normal before. Slight changes such as a small rise or a small fall in FHR after exercise were seen in 4 of 7 cases who had shown decelerations in FHR before, and in a normal case. Fetal tachycardia appeared in 2 normal cases immediately before exercise; in one case the FHR tracing appeared not to be influenced by exercise; in the other case it rested at the normal baseline level after exercise. In most cases the amplitude of baseline variability remained unchanged or decreased after exercise. The severity of deceleration before exercise did not correlate well with the results of the exercise test. The exercise test did not reveal any new patients who might have placental insufficiency, suggesting that this procedure may not be warranted for evaluating a patient with placental insufficiency. Fetal response to exercise, however, may disclose a maternal hemodynamic problem. The exercise test with FHR monitoring should be recommended to a patient with heart disease.

Adolescent↗