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Biomedical subjects

G Ishikawa

Publications and source records attributed to G Ishikawa.

At least 37 records · Page 2Linked to original sources
PubMed1995

[A case of using continuous double-tapped epidural analgesia for herpes zoster duplex].

A 66-year-old woman developed herpes zoster duplex, which is a rare disease. She had severe pain at the right upper back area and left lower abdominal area. The authors used double-tapped continuous epidural analgesia for this patient. The catheters for the epidural block were placed at the 8th thoracic vertebral level and 2nd lumbar vertebral level. After the start of continuous epidural block, she suffered from nausea, vomited, and felt dizzy. It was evident that these symptoms were caused by local anesthetic toxicity. We emphasize that we must pay attention to the patient who undergoes continuous double-tapped epidural analgesia for pain relief so as not to elicit local anesthetic toxicity.

Aged↗
PubMed1995

[Changes in dementia rating scale scores of elderly patients with femoral neck fracture during perioperative period].

We evaluated changes in dementia rating scale scores in the revised version of Hasegawa's dementia scale (HDS-R), and rated dementia, 2 days before and 7 days after surgery in the elderly patients with femoral neck fracture. The 50 patients examined ranged in age from 70 years to 101 years. A perfect score in the HDS-R is 30 points, and a score below 20 points strongly suggests dementia. The results were as follows. In septuagenarian and octogenarian patients, the scale score was higher after surgery than the value before the surgery. Although the preoperative and postoperative scores of the patients who had been under epidural anesthesia were not significantly different, the score of patients who had been under general anesthesia was higher in the postoperative period than in the preoperative period. In octogenarian patients, there was a negative correlation between "postoperative score minus preoperative score" and "the number of the days from suffering fracture to surgery". These results showed that general anesthesia is more advantageous than epidural anesthesia from the viewpoint of the intellectual faculty in septuagenarian and octogenarian patients with femoral neck fracture, and it is within the bounds of possibility that the intellectual faculty may decline if an octogenarian patient is operated after a long delay from the occurrence of fracture. To prevent this decline, patients must be operated on as soon as possible.

Age Factors↗
PubMed1994

Enhancing effect of high dietary iron on lung tumorigenesis in mice.

In our previous reports we indicated that oxidative stress on pulmonary nuclei caused by oxy radicals could be involved in glycerol-enhanced lung tumorigenesis in ddY mice treated with 4-nitroquinoline 1-oxide (4NQO). This study was undertaken to estimate if dietary iron could act as a stimulating factor on lung tumorigenesis in mice treated with 4NQO plus glycerol. Feeding excessive iron to mice treated with these agents significantly increased nuclear thiobarbituric acid reactive substances (TBARS) and DNA single strand breaks (DNA-SSB) in the lungs as compared with mice fed adequate iron 4 weeks after 4NQO injection. Nuclear non-haem iron level in mice fed excessive iron was also higher than the level in mice fed adequate iron. Twenty-three weeks after 4NQO injection (at the end of this experiment) the supply of excessive iron for 4 and 23 weeks after 4NQO injection stimulated the development of lung tumors in mice treated with 4NQO plus glycerol. These results suggest that a high dietary iron level acts as a stimulating factor on lung tumorigenesis in mice treated with 4NQO plus glycerol.

4-Nitroquinoline-1-oxide↗
PubMed1994

Phenotypic heterogeneity of an adult form of adrenoleukodystrophy in monozygotic twins.

We describe genetically proven monozygotic twins with the adult form of adrenoleukodystrophy with significant phenotypic heterogeneity. Myeloneuropathy was common to both patients, but cognitive impairment and affective symptoms with extensive demyelination in the brain were prominent in the older twin, while adrenal insufficiency was predominant in the younger twin. The younger twin, however, exhibited affective symptoms similar to those displayed by his elder twin 10 years later. These findings suggest that nongenetic factors are important in determining the phenotypic variation of adrenoleukodystrophy gene.

Adrenoleukodystrophy↗
PubMed1994

Concentration of live retrovirus with a regenerated cellulose hollow fiber, BMM.

A concentrated live retrovirus is required for in vitro experiments. A cuprammonium-regenerated cellulose hollow fiber, termed BMM, originally developed for biohazardous viral removal, was used to concentrate two different retroviruses, an ecotropic murine leukemia virus (MuLV) and human immunodeficiency virus (HIV). The BMM was useful for concentrating live virus suspension 10- to 30-fold from 500-1000 ml of culture supernatant. The ecotropic MuLV concentrated by BMM was demonstrated to be viable and biologically intact by XC plaque-forming assay and reverse transcriptase assay. The concentrated MuLV reached a much higher titer in the spleen in mice than the original one. The virus concentration assessed by p24 antigen for HIV was clearly higher than that of the original culture supernatant of HIV-infected cell lines. Since BMM hollow fibers trapped viruses by the sieving mechanism but not by adsorption, the viral particles were recovered by washing and the total live virus recovery rate was high, about 50%. Furthermore 60 min sufficed to handle 1000 ml of supernatant in the case of a filtration area of 0.03 m2. These results show that the BMM provides us with a rapid, safe and efficient method for concentrating live retroviruses.

Animals↗
PubMed1994

Comparative study on factors regulating the level of oxidative stress toward pulmonary nuclei in two different strains of mice.

1. The levels of active oxygen formed and thiobarbituric acid reactive substances (TBARS) in pulmonary nuclei of A/J strain were higher than those in the nuclei of ddY strain, while nuclear alpha-tocopherol level in the lungs of the former strain was lower than the the level in the latter strain. 2. Unsaturation index (UI) of nuclear fatty acids and oxidative damage to DNA in the lungs of A/J strain were higher than those in the lungs of ddY strain. 3. These results suggest that the capacity of nuclear active oxygen formation, nuclear alpha-tocopherol level and UI of nuclear fatty acids in the lungs can be main factors to regulate oxidative stress toward the pulmonary nuclei in the two strains of mice.

Animals↗
PubMed1994

Effect of vitamin E on 4-nitroquinoline 1-oxide-induced lung tumorigenesis in mice.

Oxidative stress may play a partial role in chemically induced tumorigenesis in mice. Herein, we investigated the preventive effect of vitamin E on 4-nitroquinoline 1-oxide (4NQO)-induced oxidative damage on pulmonary nuclei and lung tumorigenesis in mice. At 4 weeks after 4NQO injection, the levels of nuclear thiobarbituric acid substances (TBARS) and DNA single strand breaks (DNA-SSB) in the lungs of mice treated with 4NQO were significantly higher than those in the control mice. The 4NQO-induced oxidative stress on the nuclei and DNA-SSB were significantly inhibited by vitamin E treatment. The nuclear alpha-tocopherol level in the 4NQO-treated group was significantly lower than that in the control, but the plasma alpha-tocopherol level in the former was slightly lower than that in the latter. Vitamin E feeding compensated the decrease of the level in the nuclei and plasma. The feeding on excessive vitamin E for 23 weeks after 4NQO injection could partly reduce the lung tumor incidence as well as lung tumor multiplicity in mice. These findings suggest that vitamin E could partly suppress 4NQO-induced lung tumorigenesis in mice, probably through the inhibition of 4NQO-induced oxidative damage on the nuclei.

4-Nitroquinoline-1-oxide↗
PubMed1993

Is vitamin E a useful agent to protect against oxy radical-promoted lung tumorigenesis in ddY mice?

We have previously reported that oxy radicals can contribute to the enhancing effect of glycerol on 4-nitroquinoline 1-oxide (4NQO)-induced lung tumorigenesis in ddY mice. In this study, we established that feeding high doses of vitamin E to male ddY mice treated with 4NQO plus glycerol could reduce glycerol-enhanced lung tumorigenesis, due to the inhibition of glycerol-induced oxidative stress on the pulmonary nuclei. At 4 weeks after 4NQO injection (10 mg/kg, s.c.), the levels of nuclear thiobarbituric acid reactive substances and oxidative damage to DNA in the lungs of mice treated with 4NQO plus glycerol (5% solution as drinking water) were significantly higher than those in mice treated with 4NQO. The glycerol-induced increase was completely inhibited when a high vitamin E diet was provided for 4 weeks after 4NQO injection. As previously reported, at 23 weeks after 4NQO administration (at the end of this experiment), the 4 week treatment with glycerol enhanced 4NQO-induced lung tumorigenesis in ddY mice. In contrast, the supply of high doses of vitamin E at 4 and 23 weeks after 4NQO injection suppressed glycerol's ability to enhance lung tumorigenesis. These results suggest that vitamin E is useful in protecting against oxy radical-enhanced lung tumorigenesis in mice.

4-Nitroquinoline-1-oxide↗
PubMed1993

The prevention of oxy radical-mediated lung tumorigenesis in mice by vitamin E.

This work was carried out to estimate the preventive effect of vitamin E on oxy radical-enhanced lung tumorigenesis in ddY mice. We have reported that oxy radicals could be an important factor contributing to the promotive effect of glycerol on 4-nitroquinoline 1-oxide (4NQO)-induced lung tumorigenesis (1). The glycerol-promoted lung tumorigenesis of mice treated with 4NQO was reduced in mice feeding on excessive vitamin E in this study. The levels of nuclear thiobarbituric acid reactive substances (TBARS) and oxidative damage of DNA estimated as DNA single strand breaks (DNA-SSB) were significantly higher in the lungs of mice treated with 4NQO + glycerol than in those treated with 4NQO at 4 weeks after 4NQO administration, This increase was suppressed by the feeding of excessive vitamin E for 4 weeks after 4NQO injection. At 23 weeks after 4NQO injection, the feeding of excessive vitamin E for 4 and 23 weeks after 4NQO injection could cancel the promotive effect of glycerol on lung tumorigenesis. Additionally, the alpha-tocopherol level in serum was related with the degree of lung tumorigenesis at 23 weeks after 4NQO injection. These findings suggest that vitamin E can act as a useful agent to protect mice from oxy radical-promoted lung tumorigenesis.

4-Nitroquinoline-1-oxide↗
PubMed1993

Oxidative stress as a modulating factor of pulmonary tumorigenesis in mice; comparative study on two different strains.

1. Glycerol treatment enhanced NADH- and NADPH-driven active oxygen formation and thiobarbituric acid reactive substances (TBARS) in the lungs of ddY mice treated with 4-nitroquinoline 1-oxide (4NQO). 2. A glycerol-associated effect on active oxygen formation and TBARS was not observed in the lungs of A/J mice treated with 4NQO. 3. The differences in the changes of active oxygen formation and TBARS by glycerol treatment between two strains was in agreement with the difference in the enhancing effect of glycerol on 4NQO-induced pulmonary tumorigenesis in mice. This indicates that the alteration in the levels of NADH- and NADPH-driven active oxygen formation and TBARS in the lungs could play a significant role in the enhancement of tumorigenesis associated with glycerol.

4-Nitroquinoline-1-oxide↗
PubMed1991

The particle size of hepatitis C virus estimated by filtration through microporous regenerated cellulose fibre.

To estimate the particle size of hepatitis C virus (HCV), a major causative agent of post-transfusion non-A, non-B hepatitis, we filtered plasma or serum samples through microporous cellulose fibres with different pore sizes. The amount of HCV particles in samples before and after filtration was determined by a quantitative reverse transcriptase polymerase chain reaction (PCR) method. Since there is no quantitative biological assay for HCV, except for that in chimpanzees, the HCV titre obtained from the PCR method was used in an equation constructed previously for application to filtration experiments with a flavivirus which is distantly related to HCV. The particle was estimated to be between 30 and 38 nm in diameter, although the possibility remained that larger HCV particles or HCV aggregates with a diameter of more than 39 nm might exist. Double-step filtration through microporous cellulose fibres with a pore size of 35 nm reduced the HCV content to below levels detectable by our PCR method, indicating that it is possible to eliminate HCV particles by simple filtration techniques.

Base Sequence↗
PubMed1990

An attempt to prepare hepatitis B virus (HBV)-free plasma by ultrafiltration using microporous regenerated cellulose hollow fiber.

Hepatitis B virus (HBV) can be effectively removed from HBV-positive plasma by filtration with a Bemberg Microporous Membrane (BMM) with a pore size of 30 nm or less, however considerable amounts of macromolecular IgM and Factor VIII are trapped in the BMM. We report that HBV-free plasma with adequate amounts of all of the plasma proteins can be obtained by double filtration with a BMM with a port size of 50 nm. Thus it may be possible to remove HBV or other transfusion-associated viruses from plasma by BMM filtration with good recovery of all of the plasma components.

Blood Proteins↗
PubMed1985

Nodular hyperplasia of oncocytes in mouse submandibular glands.

Multinodular hyperplastic foci of oncocytes found in mouse submandibular glands were examined ultrastructurally, and their morphogenesis discussed. The oncocytic foci showed lobular architecture surrounded by myoepithelial cells, and tubular formations were frequently present. The cytoplasm of the oncocytes was distended by tightly-packed and non-oriented mitochondria which varied in size and shape. Furthermore, varying numbers of electron-dense fine granules, which were remnants of secretory granules of granular duct cells, were scattered in the cytoplasm. Within the salivary gland parenchyma neighboring the hyperplastic foci of oncocytes, intermediate-type cells between oncocytes and normal salivary gland epithelia were found. The result of the present study shows that the oncocytic change has a tendency to be more frequent in the granular ducts and less in the striated ducts, and that some oncocyte-transformed cells proliferate to form nodular hyperplastic foci.

Animals↗
PubMed1983

Experimental autoallergic sialadenitis in mice. Histopathological and ultrastructural studies.

Experimental autoallergic sialadenitis was induced in SL/Ni mice by one or two injections of syngeneic submandibular gland homogenate emulsified with adjuvant. Light microscopically, there were marked lymphoid cell infiltration in the submandibular glands with high incidence and proliferation of duct epithelia. Furthermore complete alteration of whole glandular lobules in some cases was observed. Ultrastructurally, small and medium sized lymphocytes and plasma cells constituted a major portion of the infiltrating cells, and lymphocytes were frequently observed inside the basal lamina of ductal and acinar regions, especially observed in the small ductal region. In the aggregates of infiltrating cells, the cell remnants of salivary gland epithelia were scattered. Furthermore some of the epithelial cell remnants in aggregates of infiltrating cells could be recognized as epithelial masses which were composed of proliferated duct epithelial cells, though no typical structure of epimyoepithelial islands seen in Sjögren's syndrome was found. Antisalivary duct antibody was detected in only one case.

Animals↗
PubMed1983

Ameloblastoma. Light and electron microscopic study.

Light and electron microscopic studies of ameloblastoma were reviewed. The 21 cases of ameloblastoma examined were classified into 12 cases of the plexiform type and nine of the follicular type. The average age of the patients with the plexiform type was 25.3 years, while that of those with the follicular type was 54.4 years. Histologically, in the follicular type, the tumor cells consisted of two cell types, central polyhedral and star-shaped cells resembling the stellate reticulum and peripheral cuboidal and columnar cells similar to the inner enamel epithelium. The resemblance between the tumor follicle and enamel organ was confirmed electron microscopically. In the plexiform type, however the tumor cells did not show two cell types, but resembled squamous epithelium. Electron microscopically, all cells of the tumor strands had relatively numerous bundles of tonofilaments and were joined together by desmosomes. Differentiation of tumor cells to squamous epithelium less evident than in normal surface epithelium. We speculate that these histological differences between plexiform and follicular types represent the differentiation tendency of the remnant of the dental lamina at the time of neoplastic transformation. What decides the histological pattern is unknown but age may be a factor. Central epidermization with keratinization or microcytic changes was frequently seen in the follicular type. Keratinization and microcystic changes rarely occurred in the plexiform type. We do not believe that these changes are a form of involution or result from multipotentiality of the tumor cells.

Adolescent↗
PubMed1983

Crystalloids in salivary duct cysts of the human parotid gland. Scanning electron microscopical study with electron probe X-ray microanalysis.

Crystalloids found in salivary duct cysts of the human parotid gland were examined by scanning electron microscopical observations with electron probe X-ray microanalysis. The cystic spaces were filled with numerous crystalloids which had a variety of forms with slight eosinophilic and glassy appearance. Scanning electron microscopically, crystalloids were hexagonal and rhombohedral in shape, and cutting the surface showed a polycyclic structure or regular parallel lamination. By electron probe X-ray microanalysis, sulphur was the only detected element. The present study suggests that crystalloids resulted from deposition from supersaturated saliva containing sulphur containing compounds into the cystic lumen or into epithelial cytoplasm.

Crystalloid Solutions↗