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Biomedical subjects

T Katoh

Publications and source records attributed to T Katoh.

At least 577 records · Page 32Linked to original sources
PubMed1981

[Clinical evaluation of amikacin in severe infections with hematological malignant diseases (author's transl)].

Investigation was made on absorption, excretion and clinical responses following intravenous drip infusion of amikacin (AMK) and the following results were obtained. 1) Serum concentrations of AMK were determined after completion of a 1 hour-course of its intravenous drip infusion at a dose of 200 mg, involving 2 patients with normal renal function and 1 patient with impaired renal function. In the patients with normal renal function, a mean peak serum concentration of 15.9 micrograms/ml was reached at the termination of the intravenous drip infusion and, then, gradually declined to 0.97 microgram/ml at 6 hours after completion of the intravenous drip infusion. The half-lives were 1.64 and 1.41 hours, respectively. In the patients with impaired renal function, the elimination of AMK from blood flow was markedly delayed and the serum concentration was 5.52 micrograms/ml even at 6 hours after completion of the intravenous drip infusion. The half-life was prolonged, its value being 5.98 hours. 2) The mean urinary excretion rate for the patients with normal renal function was 67.7% within 7 hours, while the patient with impaired renal function had a lower rate of 14.0%. 3) Ten infectious patients with hematological malignant diseases were treated with AMK intravenous drip infusion. Clinical responses were excellent in 6, good in 2, fair in 1 and poor in 1. Thus, 80% of the patients responded to AMK. 4) In order to check the side effects of AMK, investigation was made on the results of various clinical laboratory tests and the subjective and objective findings. But, no side effects attributed to AMK were observed. Therefore, it is thought that the intravenous drip infusion of AMK will be very useful when attention is paid to infusion time, dose and interval.

Adolescent↗
PubMed1980

Histopathologic studies of benign infantile hemangioendothelioma of the parotid gland.

Five hundred and eighty-four cases of primary parotid gland tumors and tumor-like conditions were examined. Primary benign hemangiomas of the parotid gland were relatively rare, comprising 29 cases (4.9%) of 584 tumors. These could be divided into either cavernous hemangioma or so-called benign hemangioendothelioma. In our series, the incidence of the latter was 1.5% (nine cases), or 31.0% of the total number of hemangiomas. The so-called benign hemangioendotheliomas were found in patients under the age of 12 months, during the infantile period, and occurred predominantly in females and on the right side. Histologically, this tumor showed a uniform growth pattern so that each lobular portion exhibited a strikingly identical appearance. The vascular lumina of the tumor were lined by flattened endothelial cells that were occasionally mixed with some plump cells showing mild atypism. Electron microscopy revealed that the tumor consisted of two distinct components, one being definite endothelial cells lining the vascular channels and the other pericytes located outside of the endothelium embracing the vascular channels. The tumor cells can be interchangeable with one another. It seems that this tumor is derived from the intralobular vascular system of the parotid gland. This tumor is benign in nature and found almost exclusively during the infantile period. Hence, from the clinicopathologic aspect, "benign infantile hemangioendothelioma" seems to be a more suitably descriptive term than simply "benign hemangioendothelioma".

Adolescent↗
PubMed1980

"Living electrode" as a long-lived photoconverter for biophotolysis of water.

Living blue-green algae (Mastigocladus laminosus), immobilized on an SnO(2) optically transparent electrode with calcium alginate, functioned as an anodic photoelectrode on continuous illumination for periods of time adequate for use in a conventional electrochemical cell. This "living electrode" shows promise of use as a long-lived photoconverter of solar radiant energy to electric energy and as a suitable replacement for unstable chloroplast systems.

Journal Article↗
PubMed1979

Photosynthetic vesicles with bound phycobilisomes from Anabaena variabilis.

Photosynthetically active vesicles with attached phycobilisomes from Anabaena variabilis, were isolated and shown to transfer excitation energy from phycobiliproteins to F696 chlorophyll (Photosystem II). The best results were obtained when cells were disrupted in a sucrose/phosphate/citrate mixture (0.3 : 0.5 : 0.3 M, respectively) containing 1.5% serum albumin. The vesicles showed a phycocyanin/chlorophyll ratio essentially identical to that of whole cells, and oxygen evolution rates of 250 mumol O2/h per mg chlorophyll (with 4 mM ferricyanide added as oxidant), whereas whole cells had rates of up to 450. Excitation of the vesicles by 600 nm light produced fluorescence peaks (-196 degrees C) at 644, 662, 685, 695, and 730 nm. On aging of the vesicles, or upon dilution, the fluorescence yield of the 695 nm emission peak gradually decreased with an accompanying increase and final predominant peak at 685 nm. This shift was accompanied by a decrease in the quantum efficiency of Photosystem II activity from an initial 0.05 to as low as 0.01 mol O2/einstein (605 nm), with a lesser change in the Vmax values. The decrease in the quantum efficiency is mainly attributed to excitation uncoupling between phycobilisomes and Photosystem II. It is concluded that the F685 nm emission peak, often exclusively attributed to Photosystem II chlorophyll, arises from more than one component with phycobilisome emission being a major contributor. Vesicles from which phycobilisomes had been removed, as verified by electron microscopy and spectroscopy, had an almost negligible emission at 685 nm.

Cyanobacteria↗
PubMed1979

Noninvasive recording of His-Purkinje activity in patients with complete atrioventricular block. Clinical application of an "automated discrimination circuit".

In seven patients with complete atrioventricular (AV) block, His bundle electrograms (HBEs), standard ECG recordings, bipolar esophageal ECGs and highly amplified, filtered, bipolar chest lead ECGs were simultaneously recorded. The filtered chest lead ECG was averaged to determine His-Purkinje activity (HPA). A simplified device, the "automated discrimination circuit," was used to selectively eliminate the superimposed atrial and ventricular potentials that are characteristic of complete AV block and unsuitable for signal averaging. The processed chest lead ECG was amenable to conventional techniques of signal averaging. In four patients with block proximal to the AV node diagnosed by HBE, there was no activity after the P wave in the surface-averaged ECGs. HPA was consistently recorded before the QRS in the surface-averaged ECG. The measurements of the HV and HPA-V intervals were very close, with a difference of less than 2 msec. Three patients with block distal to the His bundle by HBE showed a loss of electrical potential before the QRS in the surface-averaged ECG, but had a consistent HPA after the P waves. The P-HPA intervals coincided well with PH intervals, with a maximal difference of 5 msec.

Action Potentials↗
PubMed1979

On a new continuous cell line (TM-1) derived from malignant melanoma.

A continuous cell line of malignant melanoma has been established. The tumor specimen was obtained from a left axillary lymph node of a malignant melanoma originating in the abdominal skin of a 67-year-old woman. The cell line has been designated TM-1. Explant specimens showed positive dopa staining, but after 2 years and 4 months, or 60 generations of cell passage, the dopa staining is now weakly positive. Treatment with DBcAMP that causes marked morphological changes induces melanin production and lowers the proliferative ability of the cells. These changes were reversible. Transplantation of the cells to nude mice resulted in the formation of large tumors consisting of epithelioid cells and spindle cells. Morphologically, the majority of the cell population in vitro was polygonal epithelioid cells, but the cell passage produced a large number of spindle cells. The shape of the TM-1 cells was examined by scanning electron microscopy. Depending upon the culture conditions, either of these cell types could be predominated, indicating that both cells are of the same origin.

Aged↗
PubMed1979

In vivo and in vitro studies of experimental ovarian adenocarcinoma in rats.

When 7,12-dimethylbenz[a]anthracene-impregnated sutures were directly applied to the ovarian parenchyma of 8-week-old Sprague-Dawley rats (the clipping method), adenocarcinomas developed in 29 (39%) of the 75 rats during the 50-week observation period. When 20-methylcholanthrene was used, adenocarcinomas developed only in 1 (3%) of the 31 rats. Thus, the clipping method using 7,12-dimethylbenz[a]anthracene is satisfactory as an animal model of ovarian adenocarcinoma which comprises 85 to 90% of human malignant ovarian tumors. On the other hand, attempts were made to isolate cloned cell lines from these experimental ovarian adenocarcinomas in vitro, and two cloned cell lines were obtained. They were epithelioid and produced undifferentiated adenocarcinomas by back-transplantation into isologous newborn rats.

9,10-Dimethyl-1,2-benzanthracene↗