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Biomedical subjects

T Baba

Publications and source records attributed to T Baba.

At least 505 records · Page 28Linked to original sources
PubMed1985

Ultrastructural visualization of carbohydrates in oxytalan fibers in monkey periodontal ligaments.

Fullmer's oxytalan fibers appear to be special connective tissue fibers belonging to elastic system fibers. We have ultrastructurally examined carbohydrates in oxytalan fibers in monkey periodontal ligaments after glutaraldehyde fixation and ethylenediaminetetraacetic acid (EDTA) decalcification using: Thiéry's periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method for thin-section staining of vicinal glycol-containing complex carbohydrates, and the concanavalin A-ferritin (Con A-ferritin) and Con A-horseradish peroxidase (Con-A-HRP) en bloc staining methods specific for alpha-D-mannosyl and alpha-D-glucosyl groups. PA-TCH-SP stained collagen fibrils weakly to moderately and stained oxytalan fibers moderately. Con A-ferritin and Con A-HRP stained collagen fibrils weakly or moderately and stained oxytalan fibers intensely within the superficial region of specimen blocks. The penetration of staining reagents was improved by prior saponin treatment and/or chondroitinase ABC digestion. Thus, these studies demonstrate that PA-TCH-SP and Con A staining of carbohydrates is very useful in identifying oxytalan fibers at the ultrastructural level and that more carbohydrate components are present in oxytalan fibers than in collagen fibrils.

Animals↗
PubMed1985

A malignant pheochromocytoma with ileus, polyuria and hypercalcemia: a case of recurrence 17 years after the initial operation.

A case of malignant pheochromocytoma, with a recurrence 17 years after the initial diagnosis of benign pheochromocytoma, was presented. The autopsy revealed multiple metastases of pheochromocytoma to the bone marrow of the thoracic and lumbar vertebrae. Of particular note is the fact that the patient was associated with paralytic ileus, polyuria and hypercalcemia and that he died of hypercalcemia crisis. Cases like this appear to be very rare.

Adrenal Gland Neoplasms↗
PubMed1985

Prevalence of hypertension in diabetes mellitus--its relation to diabetic nephropathy.

The prevalence of hypertension was studied in 374 patients with non-insulin dependent diabetes mellitus (NIDDM) and in 1197 non-diabetic controls. The diagnosis of hypertension was made when the mean systolic pressure of three measurements on different occasions was 151 mmHg or greater, or the mean diastolic pressure was 91 mmHg or greater. The prevalence was 42.8% in the diabetics and 17.8% in the controls. It showed a significant difference over age 31 (p less than 0.05). Proteinuria (p less than 0.001), abnormal ECG (p less than 0.01), hyperlipidemia (p less than 0.05) and hypertensive or sclerotic changes of the retina (p less than 0.001) were more frequently observed in the diabetics than in the controls. Hypertension was found in 71% of those with proteinuria, 48% with diabetic retinopathy, 61% with abnormal ECG and 54% with hyperlipidemia in the diabetics. The incidence of proteinuria was 22.8% in the diabetic hypertensives and was 8.3% in the non-diabetic hypertensives (p less than 0.001). 24 subjects out of 119 diabetics, who were normotensive at their initial visits, became hypertensive within 10 years (N-H), and 95 remained normotensive (N-N). 38% of N-H showed proteinuria already on their initial examinations and 3% of N-N did. 73% of those who showed proteinuria on their initial examination became hypertensive and 13% of those who were free from proteinuria did (p less than 0.001). The results suggest that diabetic nephropathy plays an important role in developing hypertension in diabetics.

Adult↗
PubMed1985

[Screening for the antagonizing agents against lethal toxicity of neocarzinostatin. I. Inhibitory effects of various drugs on the toxicity of neocarzinostatin in vitro and in vivo].

Neocarzinostatin (NCS) used for the chemotherapy of leukemia and cancers such as stomach, pancreas and bladder, has been pointed out to have the side effects mainly causing leukopenia. In order to prevent these side effects of NCS by systemic administration, we have attempted to inject NCS directly into the tumor tissues and to inactivate NCS leaked from the tissues by the treatment of antidotes for NCS. The present report deals with the influence of some antidotes on the toxicity of NCS in vitro and in vivo. The results demonstrated that; Four SH-compounds, such as thiopronin, glutathione (reduced form), sodium thioglycolate and L-cysteine monohydrochloride monohydrate were effective to inactivate antibacterial activity of NCS against M. luteus ATCC 9341 in vitro. It was recognized that acute toxicity of NCS was reduced by pretreatment of these SH-compounds and its action was dose related. The LD50 values of NCS intravenous administration in mice increased 5.8- to 24-fold when 150, 300, 500 and 1,000 mg/kg of thiopronin were administered intravenously 2 minutes prior to NCS. And 2.3- to 4.2-fold by 500 and 1,000 mg/kg of glutathione (reduced form), 1.6- to 4.2-fold by 50, 100 and 200 mg/kg of sodium thioglycolate, 1.9- to 4.2-fold by 100, 200 and 400 mg/kg of L-cysteine monohydrochloride monohydrate respectively. On the other hand, pretreatment of NCS didn't affect the acute toxicity of thiopronin.

Animals↗
PubMed1985

Protection by glucose and derivatives against the lethal toxicity of mitomycin C in bacteria.

Agents capable of preventing the toxicity of mitomycin C (MMC) were investigated by a cytotoxicity assay utilizing the E. coli strain WP2 uvrA, a strain sensitive to the bactericidal action of MMC. Of various compounds, mixtures, and rat tissue extracts assayed, the solution of liver extracts and yeast extracts and DULBECCO's modified EAGLE's medium (DMEM) exhibited potent activity in protecting the cells against the MMC toxicity. A further analysis of the individual components of DMEM revealed that glucose is the active principle responsible for the protection seen with DMEM. A similar protection has been observed with the use of mannose, mannitol, 2-deoxyglucose, D-glucuronic acid, glucosamine, and N-acetylglucosamine of 16 sugar derivatives tested. The protection by glucose was specific to treatment of cells with MMC but not with UV-irradiation, cis-diamminedichloroplatinum (II), 4-nitroquinoline 1-oxide, or furylfuramide. Unlike the bacterial cells, there was no protective response in the mammalian cells in culture and in mice, given a lethal dose of MMC, concurrently with glucose or each derivative. The possible mechanisms involved in this prevention of MMC toxicity by glucose are discussed.

Animals↗
PubMed1985

[Two-route chemotherapy using a combination of anticancer agents and antidotes].

We studied the effect of "two-route chemotherapy (TRC)" in which an anticancer drug and its antidote are respectively administered locally and systemically. This therapy reduced the side effects and consequently enabled an increased dose of anticancer agents to be given. The first trial of TRC using a combination of nitrogen mustard N-oxide and its antidote cysteine was effective for the treatment of metastatic liver tumors in rats. Recently, we obtained a remarkable antitumor effect by giving a combination of cis-diamminedichloroplatinum (II) (CDDP) and sodium thiosulfate (STS) for peritoneal dissemination, bladder tumors, and liver and lung metastasis, in experimental animals, based on the evidence that STS inactivates the toxicity of DDP. This TRC using DDP and STS is now under clinical trial, and remarkable antitumor effects without nephrotoxicity have been observed. We also present evidence that the protective effect of STS against DDP toxicity is mainly due to the inactivation of active platinum in the blood stream and partly due to the diuretic effect of STS.

Animals↗
PubMed1984

Complete amino acid sequence of amelogenin in developing bovine enamel.

Pure amelogenin protein in developing bovine incisor enamel was isolated and its primary structure was investigated by sequencing the peptides obtained after clostripain and chymotrypsin digestions and CNBr degradation with an automated Edman sequencer. The enamel protein was found to be composed of 170 amino acid residues with one phosphate having a molecular weight of 19,350 and its complete amino acid sequence was elucidated. This protein has no sequence homology with any other tissue or secretory protein of known structure.

Amelogenin↗
PubMed1984

Sodium thiosulfate inhibits cis-diamminedichloroplatinum (II) activity.

To elucidate the mechanisms of inactivation of cis-diamminedichloroplatinum(II) (DDP) toxicity by its antidote sodium thiosulfate (STS), we studied the effects of STS on plasma concentrations of platinum (Pt) in vivo, binding of Pt to serum protein in vitro, and uptake of Pt by bacterial cells (E. coli, WP 2 uvrA strain) or cultured mouse tumor cells (FM3A) in vitro. STS did not significantly affect either plasma levels of total Pt or non-protein-bound Pt in vivo, but did inhibit binding of Pt to serum protein and cellular uptake of Pt in vitro. These results suggest that when DDP is given in combination with STS in vivo, the binding to macromolecules and entry of DDP into the cells are prevented due to formation of the Pt-thiosulfate complex in the extracellular fluid.

Animals↗
PubMed1984

Effect of the estrous cycle on uterine infection induced by Escherichia coli.

Escherichia coli was inoculated into the uterine lumen of rats and rabbits at different estrous stages; one uterine horn of each animal was ligated at the cervical end. In rats, a large number of E. coli were retained in the ligated horns regardless of the estrous stage. E. coli inoculated at diestrus or pseudopregnancy induced purulent endometritis, but when inoculated at proestrus-estrus the organism caused asymptomatic infection. In nonligated horns, few E. coli were recovered, and marked histopathological changes were not observed. Large numbers of E. coli were retained in the nonligated horn at proestrus as a result of physiological constriction of the cervix. E. coli inoculated at proestrus never caused purulent endometritis in either the ligated horn or the nonligated horn. In rabbits, E. coli infused into ligated horns brought about purulent inflammation irrespective of ovarian states. The number of recoverable E. coli was reduced rapidly at the follicular phase as compared with the luteal phase. These results suggest that the stage of the estrous cycle when animals are inoculated with E. coli influences the course of the uterine infection.

Animals↗
PubMed1984

Studies on N-demethylation of methamphetamine by liver microsomes of guinea-pigs and rats: the role of flavin-containing mono-oxygenase and cytochrome P-450 systems.

Relative participation of flavin-containing mono-oxygenase and cytochrome P-450 systems in N-hydroxylation of and formaldehyde release from methamphetamine were studied in vitro using liver microsomes of guinea-pigs and rats. In guinea pigs, only methimazole, an inhibitor of flavin-containing mono-oxygenase, significantly suppressed the above reactions. Formaldehyde release from methamphetamine was significantly inhibited not only by methimazole but also by inhibitors of the cytochrome P-450 system in liver microsomes from rats, but not guinea-pigs. Pretreatment of guinea-pigs with phenobarbital and 3-methylcholanthrene did not enhance the metabolism of methamphetamine. Pretreatment of rats with phenobarbital but not 3-methylcholanthrene increased slightly the N-demethylation of methamphetamine by liver microsomes. The results indicate that a marked species difference exists in the enzymes concerned with N-demethylation of methamphetamine. N-Oxidation predominates in guinea-pigs, whereas in rats, N-oxidation and C-oxidation of the methyl group participate equally as the initial reaction of the N-demethylation pathway.

Animals↗