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Biomedical subjects

H Ichikawa

Publications and source records attributed to H Ichikawa.

At least 415 records · Page 23Linked to original sources
PubMed1987

[The possibility of surgery for aged patients with gastric cancer].

The possibility of surgery for aged patients with gastric cancer has been studied. Of 484 cases who underwent a gastrectomy, patients 70 years of age or over amounted to 86 (20%). The postoperative mortality rate for these aged patients was 3% and the postoperative mortality rate with hospital deaths added from other causes than operative deaths was 7%. The postoperative mortality rate of aged patients who underwent total or proximal subtotal gastrectomy improved during the period between 1975-1983 compared with the period between 1967-1974. In the second period, there were no deaths among aged patients who underwent an R3-operation and/or a combine operation. This fact shows that operative procedures have become safer for aged patients.

Adult↗
PubMed1986

Characterization of pulmonary carbonyl reductase of mouse and guinea pig.

Carbonyl reductases were purified from mouse and guinea pig lung. The mouse enzyme exhibited structural and catalytic similarity to the guinea pig enzyme: tetrameric structure consisting of an identical 23 kDa subunit; basicity (pI of 8.8); low substrate specificity for aliphatic and aromatic carbonyl compounds; dual cofactor specificity for NADPH and NADH; stereospecific transfer of the 4-pro S hydrogen of NADPH; and sensitivity to pyrazole, 2-mercaptoethanol and ferrous ion. Although 3-ketosteroids were extensively reduced by the mouse enzyme but not by the guinea pig enzyme in the forward reaction, the two enzymes similarly oxidized some alicyclic alcohols such as acenaphthenol, cyclohex-2-en-1-ol and benzenedihydrodiol in the presence of NADP+ and NAD+. A partial similarity between the two enzymes was observed immunologically, using antibodies against the purified guinea pig enzyme. The lung enzymes differ in several aspects from other oxidoreductases from extrapulmonary tissues. The immunoreactive protein was detected only in lung of the tissues of the two species.

Alcohol Oxidoreductases↗
PubMed1986

The electroretinographic characteristics of congenital tritan defects.

Electroretinographic studies were performed in three congenital tritanopic subjects in a single pedigree. The b-waves were recorded in the presence of white and intense yellow adaptation in response to 16 monochromatic light stimuli. Compared with the response of normal subjects, a marked reduction or a lack of the blue cone responses was clearly shown in the spectral response patterns of tritanopes. Electroretinograms elicited by strong white stimulation or xenon flashes showed negative responses (a-waves larger than b-waves) with normal rod function in each tritanopic subject. This finding points to abnormalities of red cone and green cone function as well in tritanopes.

Color↗
PubMed1986

Influence of colchicine on the distribution of horseradish peroxidase in the secretory ameloblast layer in vitro.

The distribution of exogenous horseradish peroxidase (HRP) in the secretory ameloblast layer of developing rat molar tooth germs was examined in a culture system with and without colchicine. The secretory ameloblast of cultured tooth germs engulfed HRP added to the medium regardless of the presence of colchicine. The reaction product was localized in various vesicles and granules. Without colchicine in the medium, many small vesicles containing HRP were located in the Tomes' processes, whereas only a few were present with colchicine at concentrations above 5 microM. An intense reaction of HRP also appeared in the distal extracellular spaces beyond the distal junctional complexes of ameloblasts cultured without colchicine, whereas it became almost indiscernible in the tooth germs cultured with colchicine. The lack of HRP in the Tomes' processes and distal extracellular spaces of ameloblasts treated with colchicine might be attributed to the disruption of microtubules. The present study suggests that the secretory ameloblast is able to transport tracer molecules through the intracellular pathway from the proximal and lateral extracellular spaces to the distal extracellular space.

Animals↗
PubMed1986

Irreversible in vivo and in vitro binding of thiabendazole to tissue protein of pregnant mice.

In vivo experiments showed that [14C]thiabendazole is irreversibly bound to protein of the liver and embryo in pregnant mice, but not to DNA and RNA in these tissues. In experiments carried out in vitro, the binding of [14C]thiabendazole to microsomal protein of the liver was proportional to time and protein concentration, was dependent upon the presence of oxygen and NADPH and was inhibited by carbon monoxide or SKF-525A, indicating that it was mediated by the cytochrome P-450-dependent monooxygenase system. The binding capacity of microsomes in various tissues was examined, and that of the liver microsomes was found to be more pronounced than that of other tissues.

Animals↗
PubMed1986

Persistent light reaction: induction in the guinea pig.

Persistent light reactions similar to those in humans were observed in the study of photoallergenicity of chemicals in guinea pigs. The animals photoinduced with chemicals reacted to long-wavelength ultraviolet (UVA) radiation in the absence of test materials at the challenge stage. The sensitivity of the animals to UVA persisted for more than 1 year. The minimum erythema dose to UVB of animals in the treated group was less than that in the control group. Our investigations indicate that the main factors influencing the elicitation of persistent light reaction were the amount of Freund's complete adjuvant (FCA) used to enhance the allergic response in animals, and the UVA dose at the induction stage. Based on these findings, we have developed a method to make animals persistent light reactors with high frequency. This method consists of 1 intradermal injection of 1.2 ml emulsified FCA, 5 irradiations with 20.4 J/cm2 of UVA, and topical applications of 5% p-aminoethylbenzoate (benzocaine) at the induction stage. We also found that photosensitivity could be induced using FCA and UVA without photosensitizers.

4-Aminobenzoic Acid↗
PubMed1986

A technique for decalcification and demonstration of substance P-like immunoreactivity.

Substance P-like immunoreactivity (SPLI) was demonstrated in mouse spinal cord by an indirect immunofluorescence method after decalcification of the vertebra with a mixture of EDTA and Zamboni's fixative. SPLI was observed mainly in the gray matter of the spinal cord, especially the superficial layers of the dorsal horn; the distribution was the same as in the control spinal cord. No diffusion and depletion of SPLI were recognized after decalcification and no specific fluorescence was observed. The findings reported here indicate that decalcification with a mixture of EDTA and Zamboni's fixative is a useful method for examining SPLI in nervous tissue surrounded in situ by calcified tissues.

Animals↗
PubMed1986

Distribution of enkephalin-like immunoreactivity in the feline heart; its interrelation with substance P- and vasoactive intestinal polypeptide-like immunoreactive nerve fibers.

Distribution of enkephalin (Enk)-like immunoreactivity in the feline heart was investigated by indirect immunofluorescence method. Enk-like immunoreactive (Enk-IR) nerve fibers and cells predominated in the atria but were rare in the ventricles. Enk-IR cells were mainly distributed near sinoatrial (SA) node and between aorta and pulmonary artery. These cells were usually grouped in clusters near blood vessels or cardiac ganglia. Some Enk-IR cells appeared to extend their processes to other Enk-IR cells, cardiac ganglia, blood vessels and rarely cardiac muscles in the atria. Furthermore, substance P (SP)- and vasoactive intestinal polypeptide (VIP)-IR nerve fibers were closely associated with some Enk-IR cells. Moreover, the distribution and morphological profiles of Enk-IR cells were very similar to those of catecholamine (CA)-containing cells.

Animals↗
PubMed1985

Differential diagnosis of congenital tritanopia and dominantly inherited juvenile optic atrophy.

To determine whether congenital tritanopia and dominantly inherited juvenile optic atrophy (DIJOA) are the same clinical entity, we used electroretinograms of the blue-sensitive cone system (blue cone ERGs), comparing those of two patients with congenital tritanopia from two pedigrees with those of four patients with DIJOA from two pedigrees. The examinations also included visual acuity and visual field tests, fundus examination, the dark-adaptation test, and several color vision tests. The blue cone ERG confirmed a difference between the two groups; it was unrecordable in the patients with congenital tritanopia but within the normal range in those with DIJOA. We believe that congenital tritanopia and DIJOA are distinct disease entities and that the blue cone ERG is a key factor in the differential diagnosis.

Adult↗