Biomedical subjects

A Kaneko

Publications and source records attributed to A Kaneko.

At least 163 records · Page 9Linked to original sources

PubMed1995

[Study on conservative treatment of retinoblastoma--effect of intravitreal injection of melphalan on the rabbit retina].

Effects of an intravitreal injection of melphalan on the electroretinogram and on the retinal structure were studied in albino rabbits to establish the non-toxic dose for its intravitreal use. The a-wave, the b-wave, the c-wave, the oscillatory potential and the retinal structure remained unchanged after 10-micrograms injection, but moderately changed after 20-micrograms injection and greatly deteriorated after 90-micrograms injection. A 10-micrograms injection is equal to an intravitreal concentration of about 5.9 micrograms/ml, if evenly diffused in the rabbit vitreous. Considering that colony formation of in vitro retinoblastoma cells is completely suppressed by melphalan at 4 micrograms/ml concentration, an intravitreal application of melphalan could be used as a non-surgical treatment for retinoblastoma.

Animals↗

PubMed1995

[Chronic recurrent polyneuropathy in a patient with autoimmune hemolytic anemia associated with antibodies to gangliosides GM1, GA1, and GD1b].

We report a case of chronic recurrent polyneuropathy with warm-type autoimmune hemolytic anemia (AIHA) associated with antibodies to gangliosides GM1, GA1 and GD1b. There have been few reports of AIHA associated with polyneuropathy. A 39-year-old man was admitted in May 1991 because of severe hemolytic anemia. Direct Coombs' test was positive of IgG1 and complement type. The treatment was started with prednisolone, the hematological abnormalities disappeared after 6 months, but thereafter, he developed muscle weakness of all limbs and AIHA within 7 weeks. On neurological examination, he was unable to arise from a chair and could not stand, had muscle atrophy and numbness of the distal part of all limbs and areflexia. Cerebrospinal fluid was acellular and protein content was 117 mg/dl. Electrodiagnostic studies showed mild slowing of nerve conduction velocities associated with severe decrease in amplitudes of compound muscle action potential and multifocal conduction block. A sural nerve biopsy specimen showed moderate loss of small myelinated fibers, but not of unmyleinated fibers. AIHA was substantially improved by methylprednisolone (1,000 mg/day) for 3 days, but neurological symptoms remained unchanged. A month later, he was given 2 courses of intravenous gammaglobulin infusion (0.4 g/kg/day) for 5 days. He was able to walk after the second course. In May 1992, the mild motor-sensory polyneuropathy recurred and gammaglobulin infusion was effective for neurological symptoms. We detected the high level of anti-GM1 antibody titer in the patient's serum by ELISA, the level of the antibody titers correlated with neurological manifestation. A thin-layer chromatography with immunostaining showed the presence of anti-GM1, GA1 and GD1b antibodies in his serum. We grouped the reported cases of AIHA into cold and warm types, according to its hemolytic temperature, and characterized the neurological manifestations in each type. We also discussed the pathogenic role of anti-gangliosides antibodies in this case.

Adult↗

PubMed1995

Intravenous administration of vancomycin is ineffective against bacteremia following tooth extraction.

The incidence of transient bacteremia after tooth extraction without antimicrobial prophylaxis has been reported was high as 69.2%; that with intravenous ampicillin as 4.2% (1, 2). Currently, we tested a regime of vancomycin that was recommended by the American Heart Association as prophylaxis for oral surgery patients who were allergic to penicillin and evaluated its effectiveness. Before the surgical procedures, we started an intravenous drip infusion of vancomycin. Ten of 26 patients became blood culture positive (38.5%). Seventeen strains of bacteria were isolated. The Minimum Inhibitory Concentrations (MICs) of vancomycin were lower than 3.13 micrograms/ml, with just one exception.

Anti-Bacterial Agents↗

PubMed1994

Characterization of signaling pathways to Na+/H+ exchanger activation with epidermal growth factor in hepatocytes.

To investigate the signaling pathways to Na+/H+ exchanger activation with epidermal growth factor in hepatocytes, we measured changes in cytosolic free calcium and intracellular pH levels at the single-cell level using digital imaging fluorescence microscopy of fura-2- or BCECF-loaded hepatocytes in primary culture. Epidermal growth factor induced cytosolic free calcium oscillations consisting of periodic trains of spikes with a latency period of up to several minutes. These calcium responses were inhibited by tyrosine kinase inhibitor genistein (100 mumol/L) and abolished by emptying of intracellular Ca2+ pools with 3 mumol/L thapsigargin, an inhibitor of Ca(2+)-ATPase on the endoplasmic reticulum. Epidermal growth factor (1 nmol/L) induced an intracellular pH increase of 0.12 +/- 0.07 units from the basal level of 7.25 +/- 0.09 units after several minutes of latency. This effect was completely abolished by 1 mmol/L amiloride, an inhibitor of the Na+/H+ exchanger. The epidermal growth factor-induced intracellular pH increase was inhibited by pretreatment of hepatocytes with genistein (100 mumol/L), thapsigargin (3 mumol/L) or calmodulin inhibitor W-7 (25 mumol/L), but not with protein kinase C inhibitor H-7 (50 mumol/L) or with cyclic AMP-dependent kinase inhibitor H-8 (60 mumol/L). Phorbol ester PMA (phorbol 12-myristate 13-acetate), a potent activator of protein kinase C, induced a slight intracellular pH increase significantly smaller than that with epidermal growth factor, whereas this effect was completely blocked by pretreatment with H-7, indicating that PMA-induced intracellular pH increase is mediated by protein kinase C pathways, unlike epidermal growth factor.(ABSTRACT TRUNCATED AT 250 WORDS)

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1994

Mutations in the retinoblastoma gene and their expression in somatic and tumor cells of patients with hereditary retinoblastoma.

Two intragenic deletions (exon 18-19 and exon 24) and two point mutations (one missense mutation in exon 21 and one mutation at splice-donor site for exon 13) were detected in the retinoblastoma gene in somatic and tumor cells of patients with hereditary retinoblastoma. Three mutations were located in a domain essential for binding to oncoproteins encoded by DNA tumor viruses (Hu et al., 1990; Huang et al., 1990). One mutation (deletion of exon 24) was outside this domain but it is in the region essential for binding to transcriptional factor E2F, and for suppression of malignant phenotypes (Qian et al., 1992; Qin et al., 1992). A minisatellite-like sequence and short repeated sequences were located at the breakpoint of the deletion of exon 24, suggesting that two deletions on both sides of the minisatellite-like sequence may be generated by a "DNA slippage and misalignment" mechanism. Upon amplification of cDNA by the polymerase chain reaction, no transcript of gene with frameshift mutation (deletion of exon 24) was detected in skin fibroblasts, while transcripts of genes with missense mutations were detected. The results, in combination with previous reports (Dunn et al., 1989; Hashimoto et al., 1991), suggest the instability of transcripts with a premature stop codon or the suppressed expression of alleles with a premature stop codon in the retinoblastoma gene in somatic cells of hereditary patients.

Amino Acid Sequence↗

PubMed1994

Culture of retinoblastoma cells from clinical specimens: growth-promoting effect of 2-mercaptoethanol.

Establishment of new tumor cell lines is an important first step for biological studies of tumor cells. High success rates in establishing retinoblastoma cell lines have been reported when feeder-layer culture but not liquid-culture techniques were used. Liquid culture is, however, essential for studies in which feeder-layer cells are undesirable. In a previous study, we formulated a medium (RB-- medium), the components of which were almost identical to those of a soft-agar medium developed for colony formation of established retinoblastoma cell lines, in which one cell line from 12 primary retinoblastoma specimens was established. In this study, another medium (RB++ medium), RB-- medium to which 20 microM 2-mercaptoethanol and 375 microM asparagine were added, was tested for its ability to grow retinoblastoma cells from clinical specimens. In the RB++ medium, 6 cell lines from 16 primary sites, 2 from 2 intraocular-recurrent and 3 from 3 metastatic retinoblastomas grew for over a year. The major reason for the apparent improvement of the RB++ medium on the RB-- medium was demonstrated to be the addition of 2-mercaptoethanol.

Cell Division↗

PubMed1994

Parental origin of germ-line and somatic mutations in the retinoblastoma gene.

Segregation analysis of polymorphic sites within the retinoblastoma (RB) gene and on chromosome 13, as well as the parental origin of the lost allele in the tumor, were analyzed in 24 families with RB patients. Four mutant alleles transmitted through the germ-line and seven de novo germ-line mutant alleles were identified in 11 patients with hereditary RB. Segregation analysis within the RB gene and on chromosome 13 was useful for DNA diagnosis of susceptibility to RB in relatives of hereditary patients, even if mutations were not identified. All seven de novo germ-line mutant alleles were paternally derived. The bias toward the paternal allele for de novo germ-line mutations of the RB gene was statistically significant. Seven paternal alleles and six maternal alleles were lost in 13 non-hereditary RB tumors with no bias in the parental origin of the somatic allele loss. These results suggest that the physical environment or a deficiency in DNA repair during spermatogenesis may be associated with significant risk factors for de novo germ-line mutations.

Alleles↗

PubMed1994

Characterization of a cytotoxic factor produced by rat bladder cancer cell line: its identity to TNF alpha.

Clone C19 derived from a rat bladder cancer cell line BC31ad constitutively released cytotoxic factor RCF. The serum-free C19-conditioned medium was partially purified by DEAE-Sephacel, Sephacryl S-200 and MonoQ-FPLC chromatographies to the specific activity of 6.4 x 10(6) U/mg protein (LM assay). RCF was a 17-kDa protein with pI 4.6-5.0. Anti-RCF serum neutralized the cytotoxic activity of rat and mouse, but not human, tumor necrosis factor-alpha (TNF alpha) as well as RCF. The partial amino acid sequence of RCF was homologous with the sequence 43-58 of rat TNF alpha. RCF and rat TNF alpha showed a similar cytotoxic spectrum against several tumor cells. Furthermore, they induced a marked proliferation of mouse T cells in combination with a suboptimal dose of ConA or anti-CD3 antibody, however, human TNF alpha almost not. Taken together, RCF was substantially regarded as rat TNF alpha.

Amino Acid Sequence↗

PubMed1994

Subcellular localization and characterization of interleukin-1 alpha produced by rat bladder cancer cells.

A rat bladder cancer cell line BC31ad, previously reported to constitutively release tumor necrosis factor alpha (TNF alpha), was found to produce an interleukin (IL)-1-like factor inducing proliferation of murine thymocytes in a standard costimulation assay (LAF activity). IL-1-like factor was partially purified by DEAE-Sephacel, Sephacryl S-200 and MonoQ-FPLC chromatographies from the serum-free conditioned medium of a BC31 adderived clone, C19, to the specific activity of 3.2 x 10(6) U/mg and characterized as a protein of molecular weight 17 kDa with isoelectric point 5.2. LAF activity of IL-1-like factor was specifically neutralized with anti-rat IL-1 alpha but not with anti-rat IL-1 beta. These findings show that the IL-1-like factor is rat IL-1 alpha, although the precise molecular relationship with monocyte IL-1 alpha is unclear. Furthermore, IL-1 alpha was shown to be primarily located in the cytosol and plasma membrane without spontaneous release. A kinetics study indicated that it was leaked into the medium late in culture resulting from cell destruction, in contrast to TNF alpha which was released as the cell number was increased. We discussed the possible role of IL-1 alpha as an autocrine or paracrine growth regulator.

Animals↗

PubMed1994

Effect of fatty acid on the accumulation of thiamine disulfide in rat skin.

The effect of long chain fatty acid (FA) and its analogs on the accumulation of thiamine disulfide (TDS) in rat skin using propylene glycol as a vehicle was studied in vitro. Lauric acid (12:0) increased the accumulation of TDS in skin, while myristic acid and stearic acid caused a slight decrease in accumulation. Lauryl alcohol and lauric acid methyl ester did not change the accumulation of TDS in the skin. The ratio of the amount of TDS accumulated in skin to the solubility of TDS in the vehicle increased dependent on the concentration of 12:0 added in the vehicle. It was suggested that the increase in the permeability coefficient of TDS by 12:0 results from the enhanced transport of TDS from the vehicle to skin.

Animals↗

PubMed1994

[A 10-year field surveillance in Hinohara Village of Tokyo Prefecture from 1981 to 1990].

We conducted a surveillance to clarify the relationship between risk factors for diseases of adulthood and lifestyle in a Japanese rural community, Hinohara Village, a small village outside of Tokyo. The survey, carried out from 1981 to 1990 among residents aged 40 and over, comprised physical examination and blood chemistry with a questionnaire about dietary intake. Mean systolic blood pressure significantly decreased (p < 0.0001) from 140.9 mmHg in 1981 to 132.3 mmHg in 1990, whereas mean serum total cholesterol, mainly of male examinees, increased (p < 0.0001) from 181.4 mg/dl in 1981 to 191.7 mg/dl in 1990. Dietary salt intake significantly decreased (p < 0.0001) from 14.3 g/day in 1981 to 12.1 g/day in 1990. Adjusted mortality rate per 1,000 residents from cerebrovascular disease in this village decreased from 1.80 in 1981 to 0.50 in 1990. In contrast to its decline, the mortality rates from heart disease, bronchitis/pneumonia and neoplasms were 0.40, 0.35 and 0.55 in 1981 and increased to 1.25, 1.10 and 0.64 in 1990. The prevailing practice of maintaining a low-salt diet might cause the decrease of systolic blood pressure, which in turn was thought to decrease the mortality rate from cerebrovascular diseases. Although our previous study before 1981 suggested that total cholesterol was one of the preventive factors against cerebrovascular disease, in the present study a preventive effect of cholesterol was not substantiated. In contrast, cholesterol is a possible risk factor for ischemic heart disease. Thus, a changing pattern of risk factors of diseases of adulthood was observed in this village.

Adult↗

PubMed1994

Two components of GABA-induced currents in catfish retinal horizontal cells.

In cone-driven horizontal cells dissociated from the catfish retina, we recorded GABA-induced currents by using a whole-cell voltage-clamp technique. The current consisted of two components. The major component was blocked by picrotoxin, but not by bicuculline, and was identified as a current flowing through the GABAC receptor channel. The second minor component was identified as a current carried by an electrogenic GABA transporter.

Animals↗

PubMed1994

[A case of pontine hemorrhage presenting with abnormal vertical ocular movements].

A 52-year-old woman was admitted to hospital because of sudden loss of consciousness. Neurological examination on admission revealed a comatose consciousness level, horizontal and upward palsies of both eyes and quadriparesis. The diagnosis of pontine hemorrhage was confirmed based on a brain CT scan, which showed a high density area involving the bilateral pontine tegmentum and right midbrain tegmentum at the inferior collicular level. The left eye moved downward below its primary position, and the movements usually comprised rapid downward and slow upward excursions and, on occasion, slow downward and rapid upward excursions, and were arrhythmical with irregular amplitudes. Oculocephalic maneuver did not modify the ocular movements. No horizontal movements were seen with ice-cold water irrigation into the ear canal on either side. Sixty days after hemorrhage onset, her right eye began to assume the same abnormal vertical movements as the left one, and 90 days after their onset, the ocular movements became oscillations. The abnormal vertical ocular movements in our patient were characterized by irregularities of phase, rhythm and amplitude. Accordingly, they were easily differentiated from ocular bobbing and ocular dipping. As these abnormal ocular movements resembled those of a float pulled by a fish, we propose they be termed ocular floating. The paramedian pontine reticular formation (PPRF) is believed to excite the burst neurons of the rosral interstitial nucleus of medial longitudinal fasciculus (riMLF) responsible for upward gaze and inhibit those for downward gaze. This role was suggested by the clinical observation that a pontine tegmental lesion causes upward gaze palsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Hemorrhage↗

PubMed1994

Prognostic value of immunohistochemical staining for proliferating cell nuclear antigen, p53, and c-erbB-2 in sebaceous gland carcinoma and sweat gland carcinoma: comparison with histopathological parameter.

Thirteen cases of sebaceous gland carcinoma and 10 cases of sweat gland carcinoma were studied using immunohistochemical staining for proliferating cell nuclear antigen (PCNA), c-erbB-2, and p53 to examine correlations among them, and to determine the best predictor of patient prognosis. Many sebaceous gland carcinomas and sweat gland carcinomas showed nuclear accumulation of p53, and patients with tumors showing a PCNA index (percentage of nuclei stained for PCNA) higher than 20%, and a p53 index (percentage of nuclei stained for p53) higher than 10% had short survival. Sebaceous gland carcinomas and sweat gland carcinomas showing c-erbB-2 expression had high PCNA (> 20%) and p53 (> 10%) indices, and were associated with poor prognosis. Histologically, sebaceous gland carcinomas showing a high degree of differentiation and severe nucleolar atypia had high PCNA and p53 indices. A growth pattern of small solid nests and strands, a low degree of differentiation, and the presence of lymphatic permeation in sweat gland carcinoma were often associated with high PCNA and p53 indices. These results suggest that nuclear accumulation of p53 plays an important role in the development of sebaceous gland carcinoma and sweat gland carcinoma. Assessment of PCNA and p53 indices together was very useful for prognostication of patient outcome, using cut-off values of 20% and 10%, respectively, to separate good prognosis from poor. Differentiation of sebaceous gland carcinoma, and c-erbB-2 expression by sweat gland carcinoma were significant independent prognostic indicators.

Adult↗

PubMed1994

[Serum and tissue levels of cefodizime in the pediatric patients].

We administrated cefodizime (40 mg/kg) to 13 patients with simple herniorrhaphy in the pediatric field and determined its concentrations in tissues and serums. The mean serum and tissue levels of cefodizime after administration were 43.1 +/- 13.3 micrograms/ml, and 23.1 +/- 6.4 micrograms/g, respectively, at 3 hours. Cefodizime concentrations of the tissue and serum were maintained at relatively high levels for many hours. The ratio of cefodizime concentrations in tissue to serum became high at 3 hours after administration, and this suggests that tissue concentrations decreased more slowly than serum levels, and cefodizime concentrations in tissue were maintained at fairly high levels over a long period. No side effects caused by cefodizime were observed. From pharmacokinetic and clinical observations, cefodizime appears to be a safe and effective injectable antibiotic for the treatment of infections in children.

Bacterial Infections↗

PubMed1994

[Conservative therapy for retinoblastoma--effect of melphalan on in vitro electroretinogram].

The effect of melphalan (an alkylic anti-cancer drug) on rabbit and human in vitro ERGs was studied to establish the non-toxic concentration of melphalan in chemo-thermotherapy for retinoblastoma. The ERGs were recorded before and 15 min after the perfusate was changed from the control solution to a melphalan-containing solution. Melphalan 10 micrograms/ml and 40 micrograms/ml caused no significant effect on the a-wave, the b-wave, or the oscillatory potential in either the rabbit or the human in vitro ERG. Melphalan 50 micrograms/ml significantly reduced the b-wave, but the change was reversible. Considering the minimum inhibitory concentration of melphalan against retinoblastoma cells on colony assay (4 micrograms/ml), melphalan is one of the most effective drugs for the conservative treatment of retinoblastoma.

Animals↗

PubMed1994

Detection of mutations of the RB1 gene in retinoblastoma patients by using exon-by-exon PCR-SSCP analysis.

Most sporadic cases of retinoblastoma, malignant eye tumor of children, may require the identification of a mutation of the retinoblastoma gene (RB1 gene) for precise genetic counseling. We established a mutation detection system of and screened for the RB1 gene mutation in 24 patients with retinoblastoma--12 bilateral patients and 12 unilateral patients. Mutation analysis was performed by PCR-mediated SSCP analysis in the entire coding region and promoter region, as an initial screening method, followed by direct genomic sequencing. Possible oncogenic mutations were identified in 14 (58%) of 24 tumors, of which 6 were single base substitutions, 4 were small deletions, 3 were small insertions, and 1 was a complex alteration due to deletion-insertion. A constitutional somatic mosaicism was suggested in one bilateral patient. A majority (57%) of mutations were found in E1A binding domains, and all were presumed to truncate the normal gene products. The mutation analysis presented here may provide a basis for the screening system of RB1 gene mutations in retinoblastoma patients.

Base Sequence↗

PubMed1993

GTP-binding protein couples with metabotropic glutamate receptor in bovine retinal on-bipolar cell.

GTP-binding protein (G protein) linking to metabotropic glutamate receptor of bovine retinal on-bipolar cell was studied by use of pharmacologically selective ligands, 2-amino-4-phosphonobutyric acid (APB) on bacterial toxin-catalyzed ADP-ribosylation and GTP gamma S-binding. In contrast to the electrophysiological findings reported, G protein coupling to APB-sensitive glutamate receptor served as a substrate for pertussis toxin but did not for cholera toxin. Several glutamate analogues effective on on-bipolar cell, as well as APB, increased GTP gamma S binding to retinal membranes devoid of rod outer segments. The enhancement of GTP gamma S binding by APB was completely abolished when the membranes were pretreated with pertussis toxin and NAD. These results suggest that, in retinal on-bipolar cell, the G protein which couples metabotropic glutamate receptor to hyperpolarizing response of the cell is sensitive to pertussis toxin.

Animals↗