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Biomedical subjects

K Ohno

Publications and source records attributed to K Ohno.

At least 469 records · Page 26Linked to original sources
PubMed1992

A cell line derived from sphingomyelinosis mouse shows alterations in intracellular cholesterol metabolism similar to those in type C Niemann-Pick disease.

Cell lines derived from the sphingomyelinosis (gene symbol, spm) mouse were established from homozygous (spm/spm) and heterozygous (spm/+) embryos according to a rigid 3T3 transfer schedule. The SPM-3T3 cells derived from a homozygous embryo showed extensive accumulation of intracellular cholesterol, attenuated esterification of exogenously added cholesterol and increased de novo cholesterol synthesis, when compared to SPMH-3T3 cells derived from a heterozygous embryo. The phenotypic abnormalities were very similar to those observed in fibroblasts from patients with Niemann-Pick disease type C (NP-C), in which a defect in the intracellular transport of unesterified cholesterol is suggested. The genetic defect in SPM-3T3 cells should be closely related to that in NP-C. The SPM-3T3 cell line is useful for biochemical and genetic studies on the regulation of intracellular cholesterol metabolism.

3T3 Cells↗
PubMed1992

Altered surface antigen expression on peripheral blood mononuclear cells in cats infected with feline immunodeficiency virus.

Expression of CD4, CD8, IL-2 receptor alpha chain (IL-2R alpha), and MHC class II (MHC-II) on peripheral blood mononuclear cells were examined in cats infected with feline immunodeficiency virus (FIV). CD4/CD8 T cell ratio in FIV-infected cats was slightly decreased, as compared with that in specific-pathogen-free (SPF) cats. However, there was no statistical differences between them. The number of circulating IL-2R alpha+ cells in FIV-infected cats was higher than that in healthy cats, whereas induction of IL-2R alpha expression by concanavalin A (Con A) stimulation was depressed in FIV-infected cats. By using two-color cytofluorometry, Con A-induced enhancement of IL-2R alpha expression was found to be reduced in both CD4+ and CD8+ populations in PBMC from FIV-infected cats. The circulating MHC-II+ cells were also increased in FIV-infected cats. Furthermore, the induction of IL-2R alpha expression on PBMC after Con A-stimulation significantly depressed by FIV inoculation in vitro. These results suggest that FIV activates PBMC in vivo via direct and/or indirect mechanisms, leading to the unresponsive state of T cells to further stimuli in vitro.

Animals↗
PubMed1992

[Studies on reinforcing effects of methylephedrine, caffeine and their mixture with intravenous-self administration in rhesus monkeys].

The reinforcing effects of methylephedrine hydrochloride (ME), anhydrous caffeine (CA) and their mixture (ME+CA) were studied by the intravenous cross self-administration experiment and by the progressive ratio experiment in four male rhesus monkeys each. In the intravenous cross self-administration experiment, ME, CA and ME+CA were found to have reinforcing effects. Self-administration rates above the level of cocaine, a typical reinforcing drug, were not observed in ME or CA alone, but observed in their mixture (120 + 126 micrograms/kg/inj.: M dose or 480 + 504 micrograms/kg/inj.: H dose). The minimum reinforcing doses were 120 micrograms/kg/inj. (M dose) for ME, 126 micrograms/kg/inj.: (M dose) for CA, and ME 30 micrograms+CA 32 micrograms/kg/inj. (L dose) for the mixture. Vomiting was observed during the session in monkeys which showed higher self-administration rates of ME and the mixture, and decreases in the rates were observed in these animals on the next day. One animal at H dose of the mixture, which showed a high self-administration rate on both the 1st and 2nd days, died after the end of the session on the 2nd day. In the progressive ratio experiment, the final ratios at 120 micrograms/kg/inj. of ME, 126 micrograms/kg/inj. of CA and the mixture of ME 120 micrograms/CA 126 micrograms/kg/inj. were almost equal to or less than that of saline (negative control). Thus, these drugs didn't show reinforcing effects at the above levels. However, a reinforcing effect was observed in three out of four monkeys administered 1920 micrograms/kg/inj. of ME, 2016 micrograms/kg/inj. of CA, and the mixture of ME 1920 and CA 2016 micrograms/kg/inj.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Effect of glutathione content on cellular uptake and growth inhibitory activity of prostaglandin A2 in L-1210 cells.

Prostaglandin A2 (PGA2) is known to be actively incorporated into mammalian cells and thereby evokes its biological effects. To explore the transport mechanism of PGA2 and the possible role of cellular glutathione (GSH) in the transport process, we prepared GSH-enriched and -depleted L-1210 cells and then incubated with [3H] PGA2. In GSH-depleted cells, the total amount of PGA2 incorporated was reduced to about 50% of that in the control and GSH-enriched cells, accompanied by marked reduction of the PG in the cytosol but not in the nuclei. The kinetics of uptake revealed that the apparent Vmax was reduced by GSH depletion. Subsequent study of L-1210 cells under culture conditions provided similar results; GSH-depletion caused suppression of PG uptake and a reduction in the amount of PGA2 in cytosol, while its nuclear accumulation was little influenced. Comparison of the effect of PGA2 on the growth of control and GSH-depleted cells showed that the PG suppressed cell proliferation to the same extent. Our results suggest that, though uptake of PGA2 may be significantly influenced, its accumulation, and hence the manifestation of its biological effects are not influenced by GSH status.

Animals↗
PubMed1992

The domestication of Crocidura dsinezumi as a new laboratory animal.

The dsinezumi shrew (Crocidura dsinezumi), a small insectivore, has been bred for the first time as a laboratory animal. The original animals were captured using Sherman's live traps and transferred into wooden cages. After several generations they were housed in plastic cages. Their diet consisted of trout pellets, cat food, and water provided ad libitum. Monogamous pairs were housed together for 2-3 weeks for mating, and the male was separated from the female during delivery and nursing. In captivity, the reproductive activity was observed throughout the year and the gestation period was estimated at 28-30 days with a litter size of between 1 and 4 pups. Pups grew very rapidly, and reached adult body size (mean: male, 9.7 g; female, 8.3 g) and sexual maturation at 6-8 weeks of age. The reproductive life was estimated at one and a half years, while the longevity was approximately 2 years.

Animal Husbandry↗
PubMed1992

Efficacy of a new quinolone, levofloxacin in patients with surgical infections.

The pharmacokinetics and clinical efficacy of levofloxacin (LVFX, DR-3355), an optically pure S(-)-enantiomer of ofloxacin, were studied in patients after surgery. In the pharmacokinetic study, 4 patients undergoing bile drainage were given 2 100-mg tablets by mouth. Peak levels of LVFX were from 2.22 to 4.02 micrograms/ml of plasma at 2-4 hours after the oral administration, and from 7.5 to 11.3 micrograms/ml of bile at 2-6 hours. Forty-three patients with surgical infections, including 16 skin and soft-tissue infections and 12 wound infections, were treated with LVFX. Twenty-eight (70%) of the 40 patients whose results could be evaluated had excellent or good results; 42 (93%) of the 45 causative organisms identified were eradicated. An episode of diarrhea with chills and fever occurred in a 38-year-old man. The results suggested that LVFX has satisfactory antimicrobial effects in surgical infections.

Adult↗
PubMed1992

[Thoracic and lumbar sympathetic ganglion block for post herpetic neuralgia].

Of 2,667 patients with herpes zoster who visited our hospital between January 1972 and March 1989, 136 patients whose treatments were started after more than 6 months following the onset were subjects of the present study. Thus we performed a retrospective study of the therapeutic effects of sympathetic ganglion block (using alcohol) on postherpetic neuralgia left untreated for more than 6 months after the onset. After more than 1 year following the onset, the disease was nearly or completely cured in 9 of 37 patients (24%) treated with sympathetic ganglion block with alcohol and in 6 of 34 (17.6%) without the treatment. Thus the patients who underwent sympathetic ganglion block with alcohol tended to show better results. The above findings suggest that, in patients with postherpetic neuralgia in whom the initiation of treatment was delayed, treatment mainly consisting of thoracic or lumbar sympathetic ganglion block using alcohol in combination with antidepressants and antianxiety drugs can greatly improve patients' activities of daily life and that, at present, this method is most effective in relieving postherpetic neuralgia.

Aged↗
PubMed1992

[Coexistence of cerebral aneurysm and angiographically occult AVM in the occipital lobe; a case report].

The authors report a case of an 8-year-old boy with coexistent aneurysm and arteriovenous malformation (AVM) at the periphery of the left middle cerebral artery. The patient was referred to our hospital because of intracerebral hematoma in the occipital lobe. Angiography revealed an aneurysm at the periphery of the left middle cerebral artery. A small AVM was found, adjacent to the aneurysm, by histological examination of the aneurysm and surrounding tissue resected by surgery. The patient was discharged uneventfully 17 days after surgery. The association of intracranial aneurysm with AVM is reported to be seen in 1.4% of patients with intracranial aneurysms, and 6.4% to 16.7% of patients with an intracranial AVM. Three hypotheses have been proposed in order to explain the association of an aneurysm with AVM: (1) Congenital multiple disorders of vascular development, (2) Hemodynamic stress resulting from the presence of an AVM, (3) Coincidence without any causal relationship between them. The coexistence of the two vascular lesions, adjacent to each other at the peripheral cerebral arteries is rare. Only 7 cases have been reported in the literature. Four of the 8 cases including ours were children, and 6 of the 8 cases were thought to have had a hemorrhage from the AVM. It is likely that the coexistence of the two lesions in our patient is of congenital origin, because the influence of hemodynamic stress from the AVM seemed little and coexistence of the lesions as found in our case is more frequently seen in childhood.

Cerebral Angiography↗
PubMed1991

Coexistence of acetylcholine and calcitonin gene-related peptide in the vestibular efferent neurons in the rat.

An immunocytochemical study combined with the retrograde tracer technique was performed in the rat to assess the vestibular efferent system. All 3 neuron groups which give rise to axons terminating on the vestibular end-organs were cholinergic, i.e., a group dorsolateral to the genu of the facial nerve (DL), a group dorsomedial to this genu (M), and scattered cells in the parvocellular reticular nucleus (PCRt). In addition, we further demonstrated that about 55% of the cholinergic cells in DL had calcitonin gene-related peptide.

Acetylcholine↗
PubMed1991

Anemia and mast cell depletion in mutant rats that are homozygous at "white spotting (Ws)" locus.

Mice possessing two mutant alleles at the W or Sl locus are anemic and deficient in mast cells. These mouse mutants have black eyes and white hair. Because homozygous mutant rats at the newly found white spotting (Ws) locus were also black-eyed whites, the numbers of erythrocytes and mast cells were examined. Suckling Ws/Ws rats showed a severe macrocytic anemia and were deficient in mast cells. When bone marrow cells of normal (+/+) control or Ws/Ws rats were injected into C3H/He mice that had received cyclophosphamide injection and whole-body irradiation, remarkable erythropoiesis occurred in the spleen of +/+ marrow recipients but not in the spleen of Ws/Ws marrow recipients. When skin pieces of Ws/Ws embryos were grafted under the kidney capsule of nude athymic rats, mast cells did develop in the grafted skin tissues. Therefore, the anemia and mast cell deficiency of Ws/Ws rats were attributed to a defect of precursors of erythrocytes and mast cells. Because the magnitude of the anemia decreased and that of the mast cell deficiency increased in adult Ws/Ws rats, this mutant is potentially useful for investigations about differentiation and function of mast cells.

Anemia↗
PubMed1991

Purification and characterization of an enhancer-binding protein of the fibroin gene. I. Complete purification of fibroin factor 1.

An enhancer-binding protein of the fibroin gene, fibroin factor 1 (FF1), has been purified to homogeneity from crude nuclear extracts of posterior silk gland cells where this gene is transcribed specifically. There is a multiplicity of FF1; the FF1 activity was eluted as at least three major fractions on column chromatographies. FF1 is able to form a stable complex with the enhancer DNA sequence in the presence of another proteinous factor named FF2, which lacks ability to bind DNA molecules by itself. One of FF1 forms, FF1a, was purified with a combination of classical purification techniques without using a sequence-specific affinity column, and identified as a protein with molecular mass 125 kDa using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. To obtain homogeneous protein of FF1a, purification of more than 26,000-fold from the starting nuclear extract was necessary.

Animals↗
PubMed1991

Purification and characterization of an enhancer-binding protein of the fibroin gene. II. Functional analyses of fibroin factor 1.

Fibroin factor 1 (FF1) when coupled with fibroin factor 2 (FF2) is an enhancer binding protein of the fibroin gene. FF1a, one type of FF1, has been purified to homogeneity from crude nuclear extracts of posterior silk gland cells and identified as a protein with molecular mass 125 kDa (Suzuki, T., Matsuno, K., Takiya, S., Ohno, K., Ueno, K., and Suzuki, Y. (1991) J. Biol. Chem. 266, 16935-16941). FF1 is able to recognize and bind a sequence of -205 to -185 in the enhancer I of the fibroin gene in the presence of FF2. The binding sequence of FF1 with FF2 contains two repeats of the derivative of consensus sequence which is recognized by homeobox-containing proteins. Though FF1 activity to construct the major band complex I is specific to posterior silk gland cells, use of a specific antibody raised against FF1a showed that FF1 protein is ubiquitous in Bombyx cells. These results suggest the possibility that FF1 molecules present as multiple proteins might be specifically modified and activated for the binding to enhancer DNA in posterior silk gland cells. Since the FF1a antibody also inhibited a transcriptional enhancement activity governed by the enhancer sequence, we conclude that FF1 is one of the transcriptional factors of the fibroin gene. The functions of FF1 on fibroin gene transcription are discussed.

Antibodies↗
PubMed1991

Direct DNA sequencing from colony: analysis of multiple deletions of mitochondrial genome.

We have developed a rapid and efficient nucleotide sequencing technique, named the colony direct sequencing method, which combines both the conventional cloning method for picking up a single gene and the polymerase chain reaction (PCR) method for amplifying the gene directly from a colony. In the present study, the colony direct PCR product was used both for identification of the DNA insert and for nucleotide sequencing by an automated DNA analysis system. A nucleotide sequence of 300 to 400 bp could be determined within 13 h after picking the bacterial colonies on LB medium plates. We applied this method to sequencing of junctional regions of multiple deleted mtDNAs in two siblings with inherited recurrent myoglobinuria. Mitochondrial DNA fragments with deletions were amplified by PCR and then cloned into plasmids. Among 48 white colonies propagated on LB medium plates, nine different clones were identified by PCR directly from colonies. Determination of six different junctional sequences disclosed involvement of directly repeated sequences of 2 to 12 bp in length on each side of the deletions. We believe that the colony direct sequencing method will be a powerful tool in molecular genetics for identification of a single gene among polymorphic DNAs.

Adenosine Triphosphatases↗
PubMed1991

Picomolar concentrations of L-dopa stereoselectively potentiate activities of presynaptic beta-adrenoceptors to facilitate the release of endogenous noradrenaline from rat hypothalamic slices.

Interactions between (-)-isoproterenol and DOPA on the release of endogenous noradrenaline (NA) evoked by electrical field stimulation (2 Hz, alternative polarity) were studied in rat superfused hypothalamic slices in the presence of 3-hydroxybenzylhydrazine, an inhibitor of L-aromatic amino acid decarboxylase, and cocaine. Isoproterenol (0.3-3 nM) facilitated the NA release in a concentration-dependent manner, while 10 pM L-DOPA alone produced no effect. This facilitation at 0.3-3 nM was potentiated by 20-70% by simultaneously applied 10 pM L-DOPA but that at 3 nM was not modified by 10 pM D-DOPA. This potentiation of the isoproterenol (3 nM)-induced facilitation of the NA release was concentration-dependent at 1-10 pM of L-DOPA. L-DOPA methyl ester (1 nM) antagonized the L-DOPA (10 pM)-induced potentiation of the facilitation of the NA release by 3 nM isoproterenol to a level of the facilitation by isoproterenol alone, whereas 10 nM (-) propranolol antagonized both the facilitation by isoproterenol alone and its potentiation by L-DOPA to a control level. Picomolar concentrations of L-DOPA stereoselectively act on a recognition site for itself, and then potentiate activities of presynaptic beta-adrenoceptors to facilitate the NA release from rat hypothalamic slices.

Animals↗
PubMed1991

Patients with idiopathic cardiomyopathy belong to the same mitochondrial DNA gene family of Parkinson's disease and mitochondrial encephalomyopathy.

Comparison of total mitochondrial DNA sequences of patients with idiopathic (deleted or hypertrophic) cardiomyopathy with those of patients with Parkinson's disease and mitochondrial encephalomyopathies revealed distinct clustering of point mutations among patients. Furthermore, an inverse relation was found between the total number of base-substitution and life span of the patients. Among point mutations found in each patient, sequentially diverged six clusters consisting of 14, 10, 7, 1, 2, and 3 mutations, respectively, were detected. Five sub-clusters consisting of 2, 2, 11, 1, and 1 mutations, respectively, were detected. From each cluster, the patient's unique mutations were diverged with three types of the mutations specific for the disease. The divergence allowed construction of a phylogenetic tree which clearly indicated that patients with idiopathic cardiomyopathy belong to the same mitochondrial DNA gene family of Parkinson's disease and mitochondrial encephalomyopathies.

Adult↗
PubMed1991

[Radiologic features of focal nodular hyperplasia. Comparison with hepatocellular carcinoma by angiography and CT scan].

Radiographic features of eight focal nodular hyperplasia (FNH) of livers of 6 patients were described in comparison with those of 72 hepatocellular carcinoma (HCC). In arterial angiograms, 3 of the examined 4 FNH showed a large tumor vessel entering the center of the lesion. However, 1 of the examined HCC (1/39) had such a vessel. Tumor vessels in all of the examined FNH (4/4) were mainly curvilinear, without an encased and obstructive appearance. These angiographic features were not found in the examined HCC (0/39). Spoke-wheel patterns of tumor vessels were observed in 2 FNH (2/4) and in 3 HCC (3/39). In CT scan without contrast imaging, 5 HCC (5/39) and 3 FNH (3/5) were isodense. One of HCC (1/50) and 3 FNH (3/5) were isodense in the late phases of dynamic CT images. 4 HCC (4/50) and 4 FNH (4/5) had an irregular margin in the lesions. 5 HCC (5/50) and 4 FNH (4/5) demonstrated central low density areas in lesions in the early phases of dynamic CT imaging. In the late phases of the image, central high density areas in lesions were found in 2 HCC (2/50) and 3 FNH (3/5). Based on the above radiographic features such as a large tumor vessel having a curvilineal appearance, irregular margin of the lesions in FNH, we conclude that it is possible to make a differential diagnosis between FNH and HCC clinically.

Adolescent↗
PubMed1991

Distinct clustering of point mutations in mitochondrial DNA among patients with mitochondrial encephalomyopathies and with Parkinson's disease.

The total sequence data for mitochondrial DNA (mtDNA) revealed distinct clustering of point mutations (pms) in mtDNA among one patient with myoclonus epilepsy with ragged-red fibers (MERRF), two patients with Parkinson's disease (PD), two patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), and one patient with fatal infantile cardiomyopathy (FICM). Among 33 to 62 pms found in each patients, sequentially diverged five clusters of pms were detected and designated as C-1 to C-5. C-1, consisted of fourteen pms, existed in the MERRF patient, C-1 and C-2 (nine pms) in one PD patient, C-1 to C-3 (seven pms) in another PD patient, C-1 to C-4 (one pm) in one MELAS patient and C-1 to C-5 (three pms) in another MELAS patient and the FICM patient. From these clustering of pms, a phylogenetic tree of mitochondrial encephalomyopathies (ME) was constructed. This tree clearly indicated that the ME and PD patients are members of the same gene family, and the MELAS and FICM patients are each others' closest relative. Each patient's unique pms (14 to 28 pms) were detected and, from their characteristic features, the types of the mutations specific for the disease were classified as mit- + syn- for MERRF, mit- + p- for PD, and syn- + mit- for MELAS. An inverse relation was found between the total number of pms and life span of the MELAS and FICM patients.

Adolescent↗