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Biomedical subjects

H Kojima

Publications and source records attributed to H Kojima.

At least 343 records · Page 19Linked to original sources
PubMed1995

Construction and characterization of adenoviral vector expressing biologically active brain-derived neurotrophic factor.

To deliver brain-derived neurotrophic factor (BDNF) to the central nervous system, we sought to attain adenovirus-mediated transfer and expression of the gene in both in vitro and in vivo experiments. For this purpose, we constructed AxCA-BDNF, a recombinant adenoviral vector containing the BDNF cDNA expression cassette. Reverse transcription polymerase chain reaction analyses of the infected HeLa cells and the transduced mouse brain revealed successful expression of the BDNF gene both in vitro and in vivo. The results of a survival assay of chick dorsal root ganglion cells showed that the produced BDNF was biologically active. We consider, therefore, this newly constructed recombinant adenovirus to be a useful tool to deliver BDNF to degenerating neurons and to be applicable to gene therapy of neurodegenerative diseases and nerve trauma.

Adenoviridae↗
PubMed1995

Cationic multilamellar liposome-mediated gene transfer into primary myoblasts.

To transfer foreign genes into myoblasts in primary culture, we found cationic multilamellar liposomes to be a useful mediator. When the cells were transfected with 2 micrograms of the plasmid pRSV-luc encapsulated into 50 nmol of our cationic multilamellar liposomes that had been prepared from N-(alpha-trimethylammonioacetyl)-didodecyl-D-glutamate chloride, dilauroyl phosphatidylcholine, and dioleoyl phosphatidylethanolamine in a molar ratio of 1:2:2, luciferase was expressed with high efficiency without cytotoxicity. When the cells were transfected with the plasmid pRSV-lacZ encapsulated into the same liposomes, 0.7% of the cultured myoblasts expressed beta-galactosidase without cytotoxicity. This is the first successful instance of introducing foreign genes into primary cultures of myoblasts by means of liposomes.

Animals↗
PubMed1995

Hypoplasia of the internal carotid artery associated with spasmodic torticollis: the possible role of altered vertebrobasilar haemodynamics.

We describe an unusual case of hypoplasia of the left internal carotid artery associated with an anomalous origin of the ipsilateral middle cerebral artery in a patient with spasmodic torticollis. Collateral circulation to the territory of the middle cerebral artery was through the vertebrobasilar circulation, and the left vertebral artery was dilated and compressing the ventrolateral aspect of the cervicomedullary junction, as evidenced by MRI. We believe this to be the first report of unilateral hypoplasia of the internal carotid artery associated with spasmodic torticollis. Compression of the left accesory nerve by the dilated vertebral artery as a result of altered haemodynamics was thought to cause spasmodic torticollis.

Accessory Nerve↗
PubMed1995

A retrospective study of hepatitis C virus carriers in a local endemic town in Japan. A possible presence of asymptomatic carrier.

Chronic hepatitis, cirrhosis, and hepatocellular carcinoma are the accepted sequelae of chronic hepatitis C virus (HCV) infection. However, the real natural history of HCV infection is not still well understood. To approach this problem, we investigated 91 individuals positive for antibodies against HCV (anti-HCV), who have received annual liver function examination in a local town known to have had high carrier rates of hepatitis B virus (HBV) and HCV. Among the 91 anti-HCV-positive individuals, 63 had undertaken the annual examination more than five times in the past 14 years. We analyzed retrospectively the past liver function test results of these 63 subjects and evaluated their present virological status by determining HCV genotypes and estimating quantity of HCV RNA in the sera. Among the 63 subjects, 50 (79.4%) had HCV RNA in the serum and 40 (80%) of the 50 subjects with HCV RNA had abnormal alanine aminotransferase or aspartate aminotransferase level more than once in their records. However, the other 10 (20%) had no abnormal levels during the period examined. Six of 50 (12%) had ultrasonographic findings suggestive of cirrhosis. Thus, HCV-infected individuals in this area did not seem to have progressive liver diseases. Considering the advanced ages of the individuals examined (mean 64 years old), we may have observed a stage in the natural history of HCV infection in which viremia persists in most individuals and the tendency to progress to serious chronic liver disease is mild.

Base Sequence↗
PubMed1995

Interferon treatment of chronic hepatitis C in patients with hemophilia or von Willebrand's disease in Japan.

Seven patients with chronic hepatitis C, six hemophiliacs and a patient with von Willebrand's disease, were treated with interferon-alpha (IFN-alpha). Either 9 MU of recombinant IFN-alpha 2a or 3 MU of lymphoblastoid alpha-IFN was administered daily for 2 weeks and then three times a week for 22 weeks. Liver histology, hepatitis C virus (HCV) genotypes, and HCV-RNA levels in sera were investigated in all of the patients before IFN therapy was instituted. Liver histology was classified by the European classification. HCV genotyping conformed to the so-called Okamoto's classification. HCV-RNA levels in sera were quantitated by competitive polymerase chain reaction, using mutant RNA. Liver histology, HCV genotype, and serum HCV-RNA level (copies/ml) in each patient were: patient 1, chronic persistent hepatitis, type II, 3 x 10(3) respectively; patient 2, chronic active hepatitis (CAH) 2a, type III, 6 x 10(4); patient 3, CAH2a, type IV, 2 x 10(5); patient 4, CAH2b, type I, 2 x 10(7); patient 5, CAH2b, type II, 8 x 10(4); patient 6, CAH2b, type III, 7 x 10(6); and patient 7, CAH2b, type IV, 1 x 10(7). Sustained elimination of HCV was achieved in patient 3 and temporary elimination was achieved in patients 1 and 2. The other patients showed persistent HCV-RNA positivity in sera both during and after IFN treatment. Poor responsiveness to IFN was observed in patients with relatively progressive liver histology and high levels of HCV viremia.

Adult↗
PubMed1995

A case of early gastric malignant lymphoma diagnosed and completely resected by strip biopsy.

A case of early gastric malignant lymphoma definitively diagnosed by strip biopsy is reported. The subsequent operation revealed that the strip biopsy had resulted in radical resection. A 55-year-old woman visited our hospital for detailed examination of a small gastric lesion. Histologic findings of the specimens obtained by conventional forceps biopsy indicated reactive lymphoid hyperplasia, although the possibility of malignant lymphoma was not completely ruled out. Strip biopsy was, therefore, performed to establish a definitive diagnosis. Histopathological examinations of the strip biopsy specimen revealed definitive findings of malignant lymphoma, which was B-cell phenotype immunocytochemically. The margin of the resected specimen was free of invasion by malignant lymphoma and no lymph node involvement was suggested by endoscopic ultrasonography, computed tomography, and gallium scintigram. Subtotal gastrectomy was subsequently performed to rule out the possibility of remaining malignant lymphoma cells. It was proven that the strip biopsy removed the lesion completely and no perigastric lymph nodes were involved. While is still controversial as to whether strip biopsy should be adopted for the radical resection of early gastric lymphoma, this procedure can definitely provide excellent specimens for the accurate diagnosis of gastric malignant lymphoma and probably for group III lesions in the stomach.

Biopsy↗
PubMed1995

Monohexosylceramides of larval and adult forms of the tapeworm, Spirometra erinacei.

The occurrence of glycosphingolipids with unique carbohydrate structures in different species of cestode, Platyhelminth, which had been shown previously, prompted us to study the molecular species of the monohexosylceramides (cerebrosides) in the pseudophyllidean cestode, Spirometra erinacei. The purpose of the study was to obtain a basis for future investigations of the physiological role of glycolipids in parasitism. Cerebrosides were isolated from S. erinacei at two growth stages, i.e., from the larval form (plerocercoid) and from the adult tapeworms (intestinal form). The cerebrosides were separated into four subfractions by silica gel column chromatography, and their constituents were analyzed by gas-liquid chromatography, gas chromatography/mass spectrometry, and high-performance liquid chromatography/mass spectrometry. The hexoses of the cerebrosides consisted primarily of galactose in both growth stages, while only a small amount of glucose was detected. The ceramides were composed of sphinganine (d18:0) and phytosphingosine (t18:0) as sphingoid bases, and of nonhydroxy fatty acids ranging from C16 to C30 and hydroxy stearic acid (18h:0). The cerebrosides of adult tapeworms contained more 18h:0 than those of plerocercoids. The combination of hexoses and ceramides in the cerebroside molecules was slightly different in the two growth stages: the glucocerebrosides of plerocercoids contained only d18:0-nonhydroxy fatty acids in their ceramide moieties, whereas those of adult tapeworms contained varying ceramide moieties. Our data indicate that the molecular species of glycolipids present were essentially homeostatic throughout growth in spite of the entirely different environmental conditions, although there were slight differences in the hexose distribution in the two growth stages.

Animals↗
PubMed1995

The spatiotemporal range of inhibitory interaction in flicker detection.

The flicker thresholds of luminous bars were measured as a function of the spatial and/or temporal separation of two flickering stimuli. Each of the bars had an intensity profile of one-half cycle of a sinusoidal wave subtending 2.26 x 0.45 arc deg and each bar was presented twice at two positions with a duration of 10 msec. The spatial separation was defined as the distance between the adjacent flanks of two flickering stimuli, while the temporal separation was determined as the time-lag between the offset of the first flickering stimulus and the onset of the second. We found that the thresholds increased asymptotically with the spatial separation in such a way as to suggest that the spatial extent over which inhibitory interaction could be effective was as large as about 2 arc deg. We also found that the threshold gradually decreased with greater temporal separation; this indicated that the temporal proximity of successive stimuli effects less suppression on the temporal response. These two effects were seemingly additive. These findings suggest that the visual system involves not only local spatial interaction, but also a global mechanism capable of spreading inhibition over several local units after a delay of several msec.

Flicker Fusion↗
PubMed1995

Interleukin-1 beta (IL-1 beta) and acute leukemia: in vitro proliferative response to IL-1 beta, IL-1 beta content of leukemic cells and treatment outcome.

We evaluated the in vitro proliferative response to exogenous IL-1 beta in terms of tritiated thymidine (3H-TdR) incorporation in leukemic cells obtained from 119 patients with various types of acute leukemia. The content of IL-1 beta in leukemic cells was measured by enzyme-amplified sensitivity immunoassay. We observed a significant proliferative response to exogenous IL-1 beta in leukemic cells from 27/66 patients with de novo AML, 1/29 patients with ALL, 2/3 patients with AUL, 8/12 patients with AML arising from MDS, 4/7 patients with myeloid crisis of CML, and 0/4 patients with lymphoid crisis of CML. Proliferation was marked in myeloid leukemic cells of a more premature stem cell origin. There were no significant differences in proliferative responses among the different FAB classes of de novo AML. The IL-1 beta content of leukemic cells was low in patients with lymphoid leukemia, but there was no significant difference among the various types of myeloid leukemia. There was no correlation between the proliferative response to exogenous IL-1 beta and the IL-1 beta content of leukemic cells. When we correlated the proliferative response to exogenous IL-1 beta with treatment outcome in patients with de novo AML, we found the rate of complete remission (CR) to be lower in those with a high proliferative response. We noted a longer duration of CR (p = 0.07) and of survival (p < 0.05) in patients with a low proliferative response. Thus, a high proliferative response to IL-1 beta in the cells of AML patients may indicate a poor prognosis.

Acute Disease↗
PubMed1995

Clinical and laboratory characteristics in the families with diabetes and a mitochondrial tRNA(LEU(UUR)) gene mutation.

We identified three families having a mutation in the mitochondrial tRNA(LEU(UUR)) gene at bp 3243 in 300 patients with non-insulin dependent diabetes mellitus (NIDDM), who had first degree relatives of patients with NIDDM. We found six individuals with diabetes, one with impaired glucose tolerance (IGT), and five with normal glucose tolerance (NGT) among three families. Insulin secretory response to oral glucose load was impaired in six diabetics, but was normal in IGT and NGT, and the proportion of mutant DNA in the blood did not always associate with the severity of glucose intolerance. Furthermore, both gender and obesity may influence the clinical expression of diabetes in three pairs with an age-matched brother-sister relationship with similar high mutation rate in blood samples. Thus, although patients with mitochondrial gene mutation had a high frequency of diabetes, the proportion of mutant DNA evaluated by blood samples may not necessarily indicate glucose intolerance in the members with the mutation. Unidentified factors including gender, aging, and obesity may alter the clinical manifestation of diabetes.

Adolescent↗