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Biomedical subjects

T Kitagawa

Publications and source records attributed to T Kitagawa.

At least 721 records · Page 40Linked to original sources
PubMed1979

Enzyme immunoassay of bradykinin.

An enzyme immunoassay of bradykinin was developed by using beta-D-galactosidase as a labeling enzyme. Bradykinin was conjugated to beta-D-galactosidase with a new coupling agent of a hetero bis-functional type, N-(m-maleimidobenzoyloxy)-succinimide (MBS). Antisera were obtained from rabbits immunized with bradykinin linked to albumins (ovalbumin or bovine serum albumin) with toluene-2,4-diisocyanate. Double antibody method was employed to separate the antibody-bound antigen from free. The enzyme activity in the precipitate was measured with a fluorogenic substrate, 4-methyl-umbelliferyl-beta-D-galactoside. This assay is based on heterogeneous competitive binding between unlabeled and labeled antigens, so that unlabeled bradykinin reduces binding of bradykinin-enzyme conjugates to the antibody. A standard inhibition curve was linear between 3 and 300 ng bradykinin/assay tube.

Bradykinin↗
PubMed1979

Induction of enzyme-altered islands in rat liver by tryptophan pyrolysis products.

Two new gamma-carboline derivatives, 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), isolated from the pyrolysis products of tryptophan, were found to be potent mutagens. When weanling rats were injected with Trp-P-1 and then given diet containing phenobarbital, they developed enzyme-altered islands in the liver. Since these islands are considered to be formed by immediate progeny of "initiated cells" and cell precursors in hepatocarcinogenesis, Trp-P-1 may well be carcinogenic in rat liver.

Adenosine Triphosphatases↗
PubMed1979

Trisomy 9 mosaicism with punctate mineralization in developing cartilages.

A case of mosaic trisomy 9 (46,XX/47,XX,+9) is described. The main clinical findings included intrauterine growth retardation, failure to thrive, hydrocephalus, deeply set eyes, prominent antihelix, highly arched palate, subluxation of the interphalangeal joints of some fingers, hip dislocation, excessive sweating, and punctate mineralization in developing cartilages.

Abnormalities, Multiple↗
PubMed1979

A case of prolonged confusion after temporal lobe psychomotor status.

A 36-year-old man with prolonged confusion developed after psychomotor status was reported. He had no past history of epileptic seizures or psychotic disorders. The status continued for 20 hours, and twilight state and a slight fever lasted for about 10 days. Thereafter gross impairment of memory and disorientation became remarkable, and, in addition, strong psychic and autonomic disturbances developed, such as visual and auditory hallucinations, excessive excitement, disturbance of sleep, polyphagia, polydypsia, polyuria and hyperhidrosis. The CT scan, carotide angiography, CSF examination, and complement fixation tests for viruses were all within normal limits. The EEGs showed a slowing of the background activity, 0.6--0.8 Hz periodic high voltage wave discharges and random spikes in each temporal area. The clinical symptoms and EEG findings gradually improved without remarkable damage.

Adult↗
PubMed1979

Enzyme immunoassay of angiotensin I.

A very sensitive and specific enzyme immunoassay has been developed for angiotensin I. Angiotensin I was coupled to beta-D-galactosidase by a novel cross-linking reagent, N-(meta-maleimidobenzoyloxy)succinimide. No decrease in the enzyme activity was observed during the coupling procedure. In the angiotensin I-beta-D-galactosidase conjugate, 0.39 mol immunoreactive angiotensin I/mol enzyme were present. A competitive assay with the enzyme-labeled angiotensin I was performed. Antibody-bound and free labeled antigen were separated from each other by the second antibody method, and the enzyme activity of the former was estimated. Using this assay, angiotensin I could be detected in the range of 1.2--50 pg. The sensitivity was 4.5-fold higher than that of the usual RIA. This assay distinguished clearly angiotensin I from angiotensin II, angiotensin III, and (Sar1, Ile8)-angiotensin II. The present method was applied to measure PRA in dogs; the results correlated fairly well with those obtained by the RIA (r = 0.94).

Angiotensin I↗
PubMed1979

Effects of 2-nicotinamidoethyl nitrate on the cardiovascular system.

Using the dog as experimental animal, effects on the cardiovascular system of a new vasodilator, 2-nicotinamidoethyl nitrate (SG-75), were studied. In the heart-lung preparation, the compound produced a dose-dependent increase in the coronary blood flow, which was associated with only a minimal increase in the myocardial oxygen consumption. There was essentially no change in the myocardial function. The myocardial redox potential was shifted to more positive values. In the isolated perfused heart preparation (Langendorff's preparation), SG-75 produced a dilatation of only the small resistive arterioles. However, it produced a dilatation of the large conductive artery in underperfused myocardium. SG-75 produced a significant increase in the cerebral venous outflow, associated with an increase in the cerebro-spinal fluid pressure. It produced a reducation of the venous return, which was especially prominent in the lower half of the body. In the isolated smooth muscle preparation of the coronary artery, high-doses of SG-75 induced calcium antagonistic effects and produced a relaxation of the lanthanum contracture.

Animals↗
PubMed1979

Promotion by dietary phenobarbital of hepatocarcinogenesis by 2-methyl-N,N-dimethyl-4-aminoazobenzene in the rat.

The hepatocarcinogenicity of 2-methyl-N,N-dimethyl-4-aminoazobenzene, previously shown to be noncarcinogenic in adult rats in the absence of further treatment, was observed by following a 1- to 6-week period of feeding this dye to weanling rats with the dietary administration of 0.05% phenobarbital for up to 70 weeks. Many large hepatocellular carcinomas developed in the phenobarbital-treated animals by 72 weeks, whereas a very small number of tiny neoplastic nodules, including one carcinoma, were seen in the rats not given this drug. This study suggests that the use of promoting agents, following the short-term administration of weak carcinogens for the liver, can be useful in demonstrating the initiating activity of such compounds. This system may be useful in the identification of such agents in the environment.

Animals↗
PubMed1979

Ultrastructural study of pulmonary plasma cell granuloma--report of a case.

Electron microscopy of a tumour diagnosed as a pulmonary plasma cell granuloma showed that the tumour was composed of plasma cells, fibroblasts, histiocytes and other inflammatory cells. The plasma cells were mature, with abundant endoplasmic reticulum. Fibroblasts contained multiple lipid droplets and intracytoplasmic inclusions. The relationship between plasma cell granuloma and lesions believed to be related is discussed.

Adult↗
PubMed1978

Resonance Raman studies of hepatic microsomal cytochromes P-450: evidence for strong pi basicity of the fifth ligand in the reduced and carbonyl complex forms.

Resonance Raman spectra have been measured for cytochromes P-450 purified from liver microsomes of phenobarbital-treated rabbits (PB P-450 and PB P-448) and of 3-methylcholanthrene-treated rabbits (MC P-448). In the reduced state, all three cytochromes P-450 exhibit Raman spectra of ferrous high-spin type but show the so-called "oxidation state marker" (band IV) at unusually low frequencies, indicating extensive delocalization of electrons from the iron dpi orbital to the porphyrin II (eg) orbital and, consequently, the strong pi basicity of the fifth ligand of the heme iron. The reduced CO complexes of the cytochromes P-450 also exhibit band IV at markedly lower frequencies than CO complexes of hemoglobin and myoglobin. These anomalies observed for the reduced form and CO complex disappear upon conversion of the cytochromes to the catalytically inactive form called cytochrome P-420. Oxidized PB P-450 shows a Raman spectrum which is characteristic of typical ferric low-spin heme compounds, whereas those of PB P-448 and MC P-448 are of the ferric high-spin type. PB P-450 is also clearly distinguishable from the two P-448 preparations in the reduced state. The reduced form of cytochrome P-420, produced by laser illumination, exhibits two sets of Raman lines and, therefore, seems to be a mixture of both high- and low-spin species.

Animals↗
PubMed1978

Autoradiographic demonstration of DNA repair synthesis in ganglion cells of aquarium fish at various age in vivo.

Unscheduled DNA synthesis in highly differentiated ganglion cells of adult medaka (Oryzias latipes) was demonstrated by autoradiography. For this, part of bony skull of the fish was surgically removed and the brain of the living fish was directly exposed to a solution of 2 carcinogen and 3H-TdR. This technique is suitable for precise measurement of DNA repair synthesis in non-dividing cells of the central nervous system in vivo. Using this system, the effect of aging on the levels of DNA repair was investigated. There was no age-associated change in the ability of repair in ganglion cells of the medaka of various ages.

Aging↗
PubMed1978

Alkaline isomerization of thermoresistant cytochrome c-552 and horse heart cytochrome c studied by absorption and resonance Raman spectroscopy.

The structure of the thermoresistant cytochrome c (552, Thermus thermophilus) has been investigated at neutral and alkaline pH by absorption and resonance Raman spectroscopy and compared with that of horse heart cytochrome c. The ligands of the ferricytochrome c-552 at neutral pH are considered to be histidine and methionine, whereas the ligands of ferrocytochrome c-552 are histidine and another nitrogen base, histidine or lysine. Ferric cytochrome c-552 undergoes an alkaline isomerization with a pK of 12.3 (25 degrees C), accompanied by a ligand exchange. Horse heart cytochrome c has at least three isomerization states at alkaline pH (pK 9.3, 12.9 and greater than 13.5 at 25 degrees C). The replacement of the sixth ligand may not be involved in the second isomerization. The thermodynamic parameters for the isomerization were also estimated. The entropy change upon isomerization of cytochrome c-552 is negative, whereas for that of horse heart cytochrome c the entropy change is positive.

Animals↗