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Biomedical subjects

M Fukuda

Publications and source records attributed to M Fukuda.

At least 1,135 records · Page 63Linked to original sources
PubMed1986

Feeding and diurnal related activity of lateral hypothalamic neurons in freely behaving rats.

Activity of 64 single neurons in the lateral hypothalamus (LHA) was recorded for 1-8 days in freely behaving rats. The activity of 26 (40.6%) neurons varied with circadian rhythm and in relation to feeding. Activity of 23 of these neurons decreased during consumption of each pellet, and that of one increased. The activity of two other neurons increased intermittently, at night, prior to and during eating and drinking episodes. All changed activity with sleep-wake changes; increasing in the dark or upon arousal, and decreasing in the light or during slow wave sleep, but the activity was independent of individual movement, except feeding. The activity of 29 (45.3%) neurons varied only diurnally. Of these, 26 neurons also had sleep-wake responses and activity changes that corresponded to behavior. The firing rate of the other 3 neurons was independent of sleep-wake condition or individual feeding activity, but gradually increased in the dark to a maximum in the early morning, then subsided rapidly in 1-2 h. Four (6.3%) neurons were related only to feeding and not to diurnal rhythm, and 5 (7.8%) neurons were not related to either. Of the 5 neurons that were unrelated to either diurnal rhythm or feeding acts, 3 increased activity at light on and decreased it at light off for 4-13 min. These data suggest LHA neuronal involvement in control of short term feeding or individual feeding episodes, and long term feeding or circadian feeding rhythm.

Animals↗
PubMed1986

Structure of a novel sialylated fucosyl lacto-N-norhexaosylceramide isolated from chronic myelogenous leukemia cells.

A novel sialylated fucosyl glycolipid, which is present at an elevated level in chronic myelogenous leukemia cells, was isolated. The structure of this fucoganglioside was elucidated by methylation analysis, fast atom bombardment-mass spectrometry, and enzymatic degradation, followed by reaction with anti-Lex, Gal beta 1----4 (Fuc alpha 1----3) GlcNAc beta 1----, monoclonal antibody. The structure of this ganglioside was found to be: (Formula: see text). This structure is unique in that a fucose is attached to the internal N-acetylglucosamine but not to the subterminal N-acetylglucosamine. Since this glycolipid is apparently absent in normal granulocytes or acute myelogenous leukemia cells, it can be a specific marker for chronic myelogenous leukemia cells. Based on the structures of this fucoganglioside and normal granulocyte glycolipids, a biosynthetic pathway of extension, sialylation, followed by fucosylation is proposed.

Antibodies, Monoclonal↗
PubMed1986

Different instability of nuclear DNA at acid hydrolysis in cancerous and noncancerous cells as revealed by fluorescent staining with acridine orange.

Ehrlich cancer cells and inflammatory cells in mouse ascitic fluid were hydrolyzed and stained with acridine orange (AO). The AO hydrolysis curves for G1/G2 + M phase cancer cells and inflammatory cells were differentially determined using flow cytometry by monitoring the metachromatic red-shifted fluorescence of the fluorochrome bound to the single-stranded DNA produced by acid hydrolysis. By computer fitting of the Bateman function to the hydrolysis curves, the kinetic parameters k1 (rate constant for the production of single-stranded DNA), k2 (rate constant for the degradation of the produced single-stranded DNA), and y0 (theoretical value of the single-stranded DNA present initially) were determined. It was found that the k2 value, which reflects the degree of DNA instability, was much higher for cancer cells in both the G1 and G2 + M phases than for inflammatory cells. This finding led us to develop a method for the differential AO staining of cancer cells and non-cancerous cells utilizing the different degree of DNA instability at acid hydrolysis. AO staining after hydrolysis with 2N HCl at 30 degrees C for 8.5 min was found to be the optimal method. In the 60 cases of human malignant epithelial and nonepithelial tumors tested, all of the malignant tumor cells emitted metachromatic red fluorescence, while all of the nonmalignant tumor cells (5 cases of benign tumor) and normal cells emitted orthochromatic green fluorescence when observed with a violet excitation light under a fluorescence microscope. This new technique can be a useful tool for the screening of malignancy in exfoliative cytology and also for basic cancer research.

Acridine Orange↗
PubMed1986

Quantitative detection of DNA damage in the neuronal cells of the cerebellum and cerebrum by the analysis of Feulgen hydrolysis curves.

Touch smears of the cerebellum and cerebrum of ageing rats were fixed with methanol, hydrolyzed with 2 N HCl at various temperatures and for various periods, and stained with pararosaniline-Schiff reagent. The hydrolysis curves were determined by fluorescence cytophotometry and were computer fitted to the Bateman function to determine the kinetic parameters, the initial yield of apurinic acid or single-stranded DNA (y0), and the rate constants for depurination or denaturation (k1) and depolymerization (k2). The values for k1 (1/k1 is correlated with the degree of chromatin condensation) and k2 (which reflects the degree of DNA instability) steadily increased with age. The values for y0, which may indicate the degree of DNA denaturation or damage present before acid hydrolysis, also increased with age in both the cerebellum and cerebrum; however, this value was lower in the cerebellum until 15 weeks, with the situation being reversed after 35 weeks, the cross-over time being at about 25 weeks. The values of lnk1 and lnk2 were plotted as the function of the reciprocal of the absolute temperature (T) (Arrhenius plot) for both the cerebellum and cerebrum of 15- and 74-week-old rats, and the activation energies (E) for depurination and depolymerization were calculated from the slopes. In particular, the values of E for k2 decreased much more quickly with age and were smaller in cerebellum. In conclusion, the degree of DNA damage and DNA instability steadily increases in both the cerebellum and cerebrum of ageing rats, and this process is much faster in the cerebellum.

Aging↗
PubMed1986

Immunohistochemical detection of bromodeoxyuridine in formalin-fixed tissues.

Bromodeoxyuridine (BrdUrd) immunohistochemistry has recently been introduced for the visualization of DNA-synthesizing nuclei. In order to detect the BrdUrd incorporated into nuclear DNA in formalin-fixed, paraffin-embedded tissues, we tested several different pretreatment procedures including digestion with proteinase and hydrolysis with HCl, prior to immunoperoxidase staining. In order to determine the optimal conditions for detecting nuclear BrdUrd, mice were given BrdUrd and 3H-thymidine simultaneously, and the autoradiographic and immunohistochemical results obtained in BrdUrd-stained sections were compared. It was found that digestion with 0.05% proteinase at 37 degrees C for 20 min and hydrolysis with 1N HCl at 37 degrees C for 20 min was sufficient to detect BrdUrd immunoreactivity in 3H-thymidine-labelled nuclei, the results being virtually unaffected by the orders in which the two pretreatments were performed. Our method extends the range of application for BrdUrd immunohistochemistry in cell-kinetic studies.

Animals↗
PubMed1986

Bone lesions and dental caries after gastrectomy--evaluation of milk intolerance and operative procedure.

We investigated the development of bone lesions and dental caries in 350 patients who had undergone gastrectomy during the 11 year period from 1968 to 1978, on the basis of bone mineral content (BMC), decayed missing and filled (DMF) teeth and urinary c-AMP. We found that patients with low BMC and incidence of DMF teeth increased in number during the postoperative years; These abnormalities were, in comparison to the Billroth-I (B-I) and milk intake groups, significant in the Billroth-II (B-II) and non-milk intake groups. Among the gastrectomized patients, those with increased DMF teeth had significantly higher contents of urinary c-AMP. The possibility that secondary hyperparathyroidism resulting from gastrectomy contributes to the development and incidence of dental caries has to be given consideration.

Adolescent↗
PubMed1986

Improved outcome of renal transplantation with cyclosporine compared with azathioprine--experience in 33 recipients followed for over one year.

Long-term clinical aspects after kidney transplantation using cyclosporine (CsA) were studied in 33 patients who received kidney grafts from one haplotype identical living related donor and who were followed for at least one year. Both actual graft and patient survival rates were 97 per cent at one year. Incidence and severity of acute rejection were reduced to a greater extent in patients treated with CsA than in patients treated with azathioprine (AZ). The incidence of infections was low, and no serious bacterial infection occurred in these 33 patients. In 17 of 33 patients with a deteriorative graft function caused by intractable nephrotoxicity, CsA was converted to AZ. The mean serum creatinine level of converted patients was significantly higher than that of patients maintained with CsA at each time when a dose of CsA was stepwise reduced from 14 mg/kg/day to 6 mg/kg/day. Conversion to AZ improved graft function dramatically, although it resulted in reversible acute rejections in 4 patients. CsA induced hepatotoxicity occurred in 10 patients, but in all normal liver function was restored with decrease in the dose. The potent immunosuppressive effect of CsA compensates for its side effects. However, CsA should be converted to AZ when the chronic nephrotoxicity persists at a late stage of post-transplantation.

Adolescent↗
PubMed1986

Isolation of bovine follicular fluid inhibin of about 32 kDa.

Inhibin of about 32 kDa from bovine follicular fluid (bFF) was purified by using chromatographies operated under protein-dissociating conditions, which we have established for our previous purification of porcine follicular fluid (pFF) inhibin. On a gel filtration, bFF inhibin activity was eluted at 3 distinct regions corresponding to apparent molecular weight of 96, 55 and 32 kDa, representing 17%, 27% and 24% of the total inhibin activity in the follicular fluid, respectively. The smallest inhibin, named 32 kDa bFF inhibin, that evidently suppressed the basal secretion of FSH from the pituitary cells, was purified to homogeneity with a 5330-fold purification factor in a recovery yield of ca. 11%. 32 kDa bFF inhibin thus purified consists of 2 polypeptide chains (A-chain: 20 kDa and B-chain: 13 kDa), linked by disulfide bridges. N-Terminal sequences were Ser-Thr-Pro-Pro- for the A-chain and Gly-Leu-Glu-Cys- for the B-chain. The identical N-terminal sequences were also found in 32 kDa pFF inhibin, except that Pro-3 of the bFF A-chain is substituted by Ala in the 20 kDa chain of pFF inhibin.

Amino Acid Sequence↗
PubMed1986

Human hematopoietic survival and growth factor.

A variety of biologic activities on human hematopoietic stem cells were detected in 12-O-tetradecanoylphorbol-13-acetate-stimulated leukocyte-conditioned medium (TPA-LCM). Partial purification of TPA-LCM demonstrated the presence of human-active granulocyte-macrophage colony-stimulating factor (GM-CSF; Mr 50-70Kd), macrophage-CSF (M-CSF; Mr greater than 100Kd) and possibly a third protein (Mr 24-26Kd) supporting survival and growth of hematopoietic stem cells in vitro. Activities investigated included GM-colony and erythroid burst-potentiation, burst-promoting activity (BPA) and delta granulocyte and delta burst-promoting activities (delta GPA and delta BPA).

Cell Survival↗
PubMed1986

Neuronal responses in monkey lateral hypothalamus during operant feeding behavior.

Single neuron activity was recorded from monkey lateral hypothalamus to investigate neuronal events correlated with operant bar press feeding behavior. The behavioral paradigm was divided into three phase: visual (discrimination), bar press (procurement), and ingestion (consummatory). Of 669 neurons tested, 158 (24%) responded in one or more phases. During the visual phase, 106 neurons (16%) responded. Of 80 neurons that responded in the visual phase and were tested systematically, 33 (41%, 33/80) responded selectively to the sight of food or nonfood objects associated with a juice reward, but not to the sight of nonfood or objects associated with aversive saline. Neuronal activity related to discrimination was modulated by satiation and learning (i.e., acquisition and extinction). During the bar press phase, 51 neurons (7.6%) responded. These responded tonically during the early or late stage of the bar press period, but did not depend on individual bar pressing motions. During ingestion, 90 neurons (13%) responded. The ingestion response was modulated by palatability of food and satiation. Data suggest that the LHA is deeply involved in operant feeding behavior; discrimination of food, drive to get food, and perception of reward, all of which are affected by learning and internal states such as hunger and satiety.

Animals↗
PubMed1986

Glucagon-degrading activity in acid-ethanol extract of rat submandibular gland.

To investigate whether immunoreactive glucagon really exists in salivary gland, the integrity of glucagon radioimmunoassay was tested in the acid-ethanol extract of rat submandibular gland. Though immunoreactive glucagon was apparently measured in acid-ethanol extract of rat submandibular gland, the extract contained a significant amount of intact glucagon-degrading activity. The apparent % bound in radioimmunoassay highly correlated with the degradation of [125I] glucagon during incubation. Gel filtration profiles of [125I] glucagon incubated with acid-ethanol extract were the same as those of [125I] glucagon damaged by submandibular acid-saline extract. These data suggest that the immunoreactive glucagon in acid-ethanol extract is, as in the case of acid-saline extract, an artifact due to degradation of [125I] glucagon during radioimmunoassay.

Animals↗
PubMed1986

Isolation and characterization of human glycophorin A cDNA clones by a synthetic oligonucleotide approach: nucleotide sequence and mRNA structure.

In an effort to understand the relationships among and the regulation of human glycophorins, we have isolated and characterized several glycophorin A-specific cDNA clones obtained from a human erythroleukemic K562 cell cDNA library. This was accomplished by using mixed synthetic oligonucleotides, corresponding to various regions of the known amino acid sequence, to prime the synthesis of the cDNA as well as to screen the cDNA library. We also used synthetic oligonucleotides to sequence the largest of the glycophorin cDNAs. The nucleotide sequence obtained suggests the presence of a potential leader peptide, consistent with the membrane localization of this glycoprotein. Examination of the structure of glycophorin mRNA by blot hybridization revealed the existence of several electrophoretically distinct mRNAs numbering three or four, depending on the size of the glycophorin cDNA used as a hybridization probe. The smaller cDNA hybridized to three mRNAs of approximately 2.8, 1.7, and 1.0 kilobases. In contrast, the larger cDNA hybridized to an additional mRNA of approximately 0.6 kilobases. Further examination of the relationships between these multiple mRNAs by blot hybridization was conducted with the use of exact-sequence oligonucleotide probes constructed from various regions of the cDNA representing portions of the amino acid sequence of glycophorin A with or without known homology with glycophorin B. In total, the results obtained are consistent with our hypothesis that the three larger mRNAs represent glycophorin A gene transcripts and that the smallest (0.6 kilobase) mRNA may be specific for glycophorin B.

Amino Acid Sequence↗
PubMed1986

A cDNA clone used to study mRNA inducible in human tonsillar lymphocytes by a tumor promoter.

A cDNA clone inducible by either a tumor promoter, 12-o-tetradecanoyl phorbol-13-acetate (TPA), or a T-cell mitogen, phytohemagglutinin (PHA), was isolated from a cDNA library constructed from the poly(A) + RNAs of TPA- and PHA-stimulated human tonsillar lymphocytes, and was named pLD78. Stimulation of the tonsillar lymphocytes with either TPA or PHA increased the amount of pLD78-specific RNA by about 10-fold, and simultaneous stimulation with TPA and PHA, by at least 30-fold. Analysis of the pLD78 cDNA sequence revealed that it codes for a polypeptide consisting of 92 amino acid residues, including a putative signal sequence. Moreover, the sequence of the 5' flanking region of the nuclear DNA encoding for the pLD78 cDNA showed a significant homology with the corresponding regions of the human interleukin 2 and immune interferon genes.

Amino Acid Sequence↗
PubMed1986

Molecular cloning, DNA nucleotide sequencing, and expression in Bacillus subtilis cells of the Bacillus macerans cyclodextrin glucanotransferase gene.

The gene for cyclodextrin glucanotransferase from Bacillus macerans was cloned in an Escherichia coli bacteriophage, lambda D69, and was recloned in a Bacillus subtilis plasmid, pUB110. Starting from an ATG initiation codon, a unique reading frame was shown to extend for 2,142 base pairs (714 amino acids). The nucleotide sequence revealed that the enzyme is composed of two identical subunits.

Amino Acids↗
PubMed1986

Hypothalamic neuron involvement in integration of reward, aversion, and cue signals.

The lateral hypothalamus (LHA) is involved in integrative functions related to emotion, reward, aversion, and learning. It is, however, unclear whether the medial forebrain bundle (MFB) forms a substrate common to the anterior and posterior hypothalamic areas or whether information regarding rewarding and aversive stimuli converges on and is integrated by the same hypothalamic neuron. In the present study, unit activity in the LHA and lateral preoptic-anterior hypothalamic area (lPOA-AHA) of the rat was recorded during discrimination learning of cue tone stimuli (CTS) that predicted glucose or intracranial self-stimulation (ICSS) as rewarding stimuli, or electric shock or tail pinch as aversive stimuli, using identical behavior, licking. We examined functional differences between the LHA and lPOA-AHA. In positive reinforcement experiments a rat was rewarded by glucose or ICSS only when it licked a spout presented in front of its mouth. The threshold current for ICSS was used. In negative reinforcement experiments an aversive stimulus, either electric shock or tail pinch was applied if the rat did not lick the spout. The strengths of electric shock and tail pinch were selected to produce an avoidance ratio less than 20-30%, averaged in all trials. The activity of 507 LHA and 249 lPOA-AHA neurons was analyzed during both glucose and ICSS trials. The effects of both glucose and ICSS on the same LHA or lPOA-AHA neuron were usually in the same direction, i.e., either both excitatory or both inhibitory. Of 143 LHA and 44 lPOA-AHA neurons that responded to both rewards, the responses of 117 (81.8%) LHA and 35 (79.5%) lPOA-AHA neurons to both stimuli were similar. The activity of 131 LHA and 153 lPOA-AHA neurons was analyzed in both electric shock and tail pinch trials. The effects of both electric shock and tail pinch on the same LHA or lPOA-AHA neuron were usually in the same direction. Of 29 LHA and 27 lPOA-AHA neurons that responded to both aversive stimuli, the responses of 28 (96.6%) LHA and 25 (92.6%) lPOA-AHA neurons to both were similar. The activity of 170 LHA and 195 lPOA-AHA neurons in response to both rewarding glucose and/or ICSS stimulation and aversive electric shock and/or tail pinch was analyzed. About one-third of the neurons in each area were reward specific (57/170 in LHA; 63/195 in lPOA-AHA), whereas relatively few were aversion specific in each area (21/170 in LHA; 15/195 in lPOA-AHA).(ABSTRACT TRUNCATED AT 400 WORDS)

Acoustic Stimulation↗