Search PubMed⌕ Search

Biomedical subjects

K Iijima

Publications and source records attributed to K Iijima.

At least 271 records · Page 15Linked to original sources
PubMed1986

Mononucleotide metabolism in the rat brain after transient ischemia.

Nucleotide metabolism was studied in rats during and following the induction of 10 min of forebrain ischemia (four-vessel occlusion model). Purine and pyrimidine nucleotides, nucleotides, and bases in forebrain extracts were quantitated by HPLC with an ultraviolet detector. Ischemia resulted in a severe reduction in the concentration of nucleoside triphosphates (ATP, GTP, UTP, and CTP) and an increase in the concentration of AMP, IMP, adenosine, inosine, hypoxanthine, and guanosine. During the recovery period, both the phosphocreatine level and adenylate energy charge were rapidly and completely restored to the normal range. ATP was only 78% of the control value at 180 min after ischemic reperfusion. Levels of nucleosides and bases were elevated during ischemia but decreased to values close to those of control animals following recirculation. Both the decrease in the adenine nucleotide pool and the incomplete ATP recovery were caused by insufficient reutilization of hypoxanthine via the purine salvage system. The content of cyclic AMP, which transiently accumulated during the early recirculation period, returned to the control level, paralleling the decrease of adenosine concentration, which suggested that adenylate cyclase activity during reperfusion is modulated by adenosine A2 receptors. The recovery of CTP was slow but greater than that of ATP, GTP, and UTP. The GTP/GDP ratio was higher than that of the control animals following recirculation.

Adenosine↗
PubMed1986

Ultrastructural and morphometric studies of nonsecretory neurons of the rat supraoptic nucleus.

Ultrastructural and morphometric studies were made on nonsecretory and complementarily neurosecretory neurons of the rat supraoptic nucleus. 6% of perimeter of nonsecretory neuronal perikarya was covered by presynaptic endings. The value was well in agreement with that of interneurons elsewhere. The covering ratio of neurosecretory neurons was 12%. The perikarya of nonsecretory and neurosecretory neurons bear an average of 14 and 49 axon terminals, respectively. Nonsecretory neurons should be interneurons, receiving much less information than neurosecretory neurons.

Animals↗
PubMed1986

Immunohistochemical studies on the GABAergic system in the rat supraoptic nucleus using the PAP method with an application of electron microscopy.

GABAergic neuronal profiles in the supraoptic nucleus of the rat were immunohistochemically identified by using a purified GABA antibody with the peroxidase-antiperoxidase method. The localization of GABA-like immunoreactivity in nerve terminals on the neurosecretory neurons was examined electron microscopically. A few small GABAergic neurons were found inside the supraoptic nucleus while only a very few medium-sized ones were detected in the perinuclear zone. Intrinsic, non-GABAergic small neurons covered by GABAergic neuropil were also detected. The neuropil with GABAergic axo-somatic synapses evenly encompassed unlabeled neurosecretory perikarya throughout the supraoptic nucleus. The GABAergic system seems to inhibit both vasopressin and oxytocin cells. In this area, glia cells showed clear outlines of unlabeled somata around counter-stained nuclei. Blood capillaries in the supraoptic nucleus were only slightly covered with a GABAergic neuropil. Electron microscopic observations demonstrated the presence of GABAergic axo-somatic symmetrical and axo-dendritic asymmetrical synapses on the neurosecretory neurons. GABA-like immunoreactivity was localized on the membranes of microtubules and synaptic vesicles, on the external membranes of the mitochondria, and on the inner leaf of the presynaptic sites. Numerous pairs of non-immunoreactive synapses were arranged along these immunoreactive synapses.

Animals↗
PubMed1986

[Clinical studies on the transference of cephem-type antibiotics into bile and gallbladder tissues with special reference to cefotiam and cefmenoxime].

Cefotiam (CTM) and cefmenoxime (CMX) were studied for their serum concentrations and transference into bile in patients with PTCD or T-tube. One gram of CTM or either 1 g or 2 g of CMX was administered by an intravenous drip infusion for over 30 minutes. These drugs were also studied for their serum concentrations, bile concentrations, and tissue concentrations in the walls of the gallbladder of patients operated on for cholelithiasis. Intravenous drip infusion (over 30 minutes) was used to administer 1 g of CTM or 1 g or 2 g CMX immediately before surgery. Both CTM and CMX were readily transferred into bile. Their bile concentrations, however, varied greatly among patients, and extremely low levels were detected in some patients. A crossover analysis of concentrations of CMX in bile of patients given doses of 1 g and 2 g revealed a dose-response relationship. The crossover analysis of drug concentrations in bile of patients given CTM and CMX showed that CMX is transferred more readily to bile. The relationship between liver functions and drug transfer to bile was examined by plotting the total bilirubin level against drug concentrations in bile. The plots formed an exponential curve with a correlation coefficient (r) being -0.52 in cases when each subjects received 1 g of CTM and -0.72 in cases when each subjects received 1 g of CMX. A study of 3 patients given CMX at a dose of 1 g suggested that bile levels of CMX may be correlated to ICG. Concentrations of CTM and CMX in tissues of the gallbladder wall were fairly high, with unexpectedly small variance among patients. Even in patients with low bile concentrations of these drugs, drug levels in the tissues of the gallbladder wall were high. Drug levels in the noninflammatory tissues were higher than those in inflammatory lesions. The above findings suggest that CTM should be the antibiotic of choice for patients with ordinary biliary tract infections and after the surgery of the liver and biliary tract system, while CMX should be the antibiotic of choice for patients with severe biliary tract infections, and for compromised hosts after the surgery of the liver and biliary tract system.

Aged↗
PubMed1986

[Penetration of cefotaxime into human bone marrow blood].

Concentrations of cefotaxime (CTX) in bone marrow blood and venous blood were examined with the passage of time in 21 cases which received operations of bone and joint. Concentrations of CTX in bone marrow blood at 30 minutes of a single intravenous administration 2 g each of CTX were found to be 85.2 +/- 24.5 micrograms/ml. Concentration ratio of CTX in bone marrow blood to that in venous blood was reached the peak at 120 minutes after administration. Concentrations of CTX observed were higher than the MIC of CTX against major pathogens responsible for the postoperative infections in orthopaedic field. The CTX, therefore, is expected to have an effective antibiotic in prophylaxis.

Adolescent↗
PubMed1986

Growth, psychologic characteristics, and sleep-wakefulness cycle of children with sex chromosomal abnormalities.

This study of girls with Turner syndrome (16 cases) and boys with XXY (two cases) and XYY (eight cases) constitutions was designed to follow the longitudinal growth and to analyze the psychologic findings and the sleeping patterns in them. The growth curves of stature in Turner syndrome were below the 3rd percentile at all ages. The mean of SDS of height in cases less than 5 years old was -2.38, that in cases older than 6 years old -2.40. The shoulders in Turner syndrome have a tendency to broaden with time, in contrast to the development of the pelvis, which is not so good. The height of 47,XYY boys from infancy to 9 years of age was between the 10th and 90th percentiles, with one exception in which the height was above the 90th after 8 years of age. Relatively common psychologic findings in cases with Turner syndrome were as follows: low responsiveness to emotional stimuli, poor emotional expressions, passive and negative mental attitudes, low activity and low productivity, narrow and limited interests, passiveness and common sense adaptability, lower impulsiveness and aggressiveness, etc. The circadian oscillation was observed up to 3 years of age with shifting of the sleeping time to the night period. After that, day sleep gradually tends to decrease with age. Age variation in day and night sleep of an XXY boy was compared with that of a normal child. This showed the normal variation in circadian rhythms in early childhood, although the infant with this syndrome slept more, both day and night, than normal. In early childhood, no difference was noted. Similar studies were performed on a child with the chromosomal aberration XYY and revealed the sleep parameters to be quite normal in infancy and early childhood.

Adolescent↗
PubMed1985

Isolation of simian retroviruses closely related to human T-cell leukemia virus by establishment of lymphoid cell lines from various non-human primates.

Simian retroviruses closely related to human T-cell leukemia virus (HTLV) were isolated by establishing virus-producing lymphoid cell lines from 7 species of non-human primates. By co-cultivation with human umbilical cord-blood cells and/or in the presence of interleukin-2, lymphoid cell lines were successfully established from the chimpanzee. African green monkey, pig-tailed macaque, red-faced macaque, Formosan monkey, Japanese monkey and bonnet monkey that had antibodies against HTLV antigens. These cell lines reacted with human sera of ATL patients and monoclonal antibodies against p19 and p24 of HTLV antigens. Cellular DNAs contained the provirus sequences homologous to HTLV-I by Southern blot hybridization. Moreover, they produced extracellular type-C virus particles and RNA-dependent DNA polymerase. All of these lymphoid line cells had Tac antigen, interleukin-2 receptor, and those of chimpanzee and red-faced macaque had helper/induced T-cell markers, while those derived from African green monkey had suppressor/cytotoxic T-cell markers. Furthermore, simian HTLV-related viruses of pig-tailed macaque, red-faced macaque and Japanese monkey were transmitted to human lymphocytes on co-cultivation.

Animals↗
PubMed1984

Human health situation and chromosome alterations: sister chromatid exchange frequency in lymphocytes from passive smokers and patients with hereditary diseases.

Lymphocytes from passive smokers, and patients with FA, Alz, or FPC were studied for SCEs in cultures treated with MMC, 4NQO, or MNNG. Fanconi anemia lymphocytes were also studied for cell cycle Tab. 3. Mean SCE frequencies in FPC or normal cells. (Table; see text) kinetics, and CAs after completion of 1, 2, or 3 or more divisions in MMC-treated cultures. The results can be summarized as follows: (1) lymphocytes from passive smokers showed a slightly higher induction of SCEs than nonsmokers when exposed to MMC. (2) FA cells had about 1.4 times higher frequencies of SCEs than normal cells in both MMC-treated and untreated cultures while they showed several times higher frequencies of CAs in both cultures. Analyses of cell cycle kinetics by the sister chromatid differential staining method revealed that MMC treatments of FA and normal cells led to a clearly dose-related delay in cell turnover times, the duration of delay being much longer in FA than in normal cells. (3) Alz cells showed about 1.5 times higher induction of SCEs in MMC-treated cultures whereas they had only 10% as much SCEs as controls when exposed to 4NQO. Familial polyposis coli cells showed no significant difference in the induction of SCEs in untreated cultures and cultures treated with MMC, 4NQO, and MNNG.

4-Nitroquinoline-1-oxide↗
PubMed1984

Bleomycin-induced chromosomal aberrations and sister chromatid exchanges in Down lymphocyte cultures.

Peripheral blood lymphocytes from three patients with Down syndrome (DS; trisomy 21; aged 5-6 years) and three age-matched control children were studied for the induction of chromosomal aberrations and sister chromatid exchanges (SCEs). Cells in G0 were exposed to bleomycin (20-100 micrograms/ml) for 3 h, and then cultured in medium containing 5-bromodeoxyuridine and phytohemagglutinin for 66 h. By the sister chromatid differential staining method, chromosome analyses were performed on metaphase cells that had divided one, two, or three or more times after treatment. The results indicate that DS cells exposed to bleomycin are hypersensitive to the production of dicentric and ring chromosomes compared to normal cells. Bleomycin also led to a dose-related increase in the frequency of SCEs, but no difference was found between the SCE frequencies in DS or normal lymphocytes exposed to bleomycin.

Bleomycin↗
PubMed1984

Enzyme-histochemical studies on the nonsecretory neurons of the rat supraoptic nucleus with the application of karyometry and electronmicroscopy.

Detailed histochemical studies were conducted on the distribution of SDH, G6PD, and TPPase as well as the Nissl substance and Gomori-positive material in the nonsecretory neurons of the supraoptic nucleus (SO) of the adult Wistar strain rats. Karyometry and statistical analysis were performed to identify those neurons. Electron microscopy confirmed the cytological characteristics indicated by the histochemical results. Based on the classification of SO neurons by the Golgi-Cox method and the present results concerning the Nissl pattern, shape, size, and number, these nonsecretory neurons appear to be intercalated neurons. Weak SDH and G6PD activity in the perikaryon with a few mitochondria indicate that they belong to the category of ordinary neurons with a low level of carbohydrate metabolism. The TPPase reaction revealed heterogeneous Golgi apparatus (GA) with poor development. In addition, it was difficult to find profiles of GA in many ultrathin sections. These results indicate that the GA may not undergo cyclic activity and lacks the capacity for secretion. No Gomori-positive material was detected in the perikaryon, whereas the Nissl substance was densely distributed throughout the entire perikaryon, where many free ribosomal rosettes and junctions of cisternae of abundant granular reticulum were evenly dispersed. The nonsecretory neurons reflect an active phase of cyclic activity of protein synthesis. However, other nonsecretory neurons with less active protein synthesis are very likely to be present.

Animals↗