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Biomedical subjects

A Fukuda

Publications and source records attributed to A Fukuda.

At least 271 records · Page 15Linked to original sources
PubMed1965

Increased activities of glycogenolytic enzymes in liver after splanchnic-nerve stimulation.

Electrical stimulation of the splanchnic nerve of rabbits caused a marked increase, within 30 seconds after the onset of stimulation, in liver-glycogen phosphorylase and glucose-6-phosphatase activities. The increased activity of liver phosphorylase after splanchnic-nerve stimulation was likewise observed in adrenalectomized and pancreatectomized rabbits. Glycogen content of the liver decreased only slightly after 5-minute stimulation.

Adrenalectomy↗
PubMedDate not supplied

Substance P effects on the dorsal motor nucleus of the vagus.

Substance P (SP) was applied by superfusion (0.8 to 3.4 x 10(-6) M) to neurons of the dorsal motor nucleus of the vagus (DMV) in slice preparations of the rat medulla oblongata. Intracellular recordings showed that 18 of 43 (42%) neurons were depolarized and the depolarization was associated with an increase in membrane input resistance; five of 43 (12%) neurons were hyperpolarized and the hyperpolarization was associated with a decrease in membrane input resistance. Both effects were reversible and persisted after blockade of synaptic transmission by Ca2+ free/high Mg2+ solution. These data show that: 1) vagal neurons in the DMV have receptors for SP; 2) SP may modulate vagal output specially by increasing neuronal excitability; 3) although electrophysiological effects of SP have been studied in a variety of central and peripheral neurons, this is the first evidence of SP effects on DMV; 4) DMV is a particular brain target site in which SP may induce depo- or hyperpolarization.

Action Potentials↗
PubMedDate not supplied

Reduced immunogenicity of beta-lactoglobulin by conjugation with carboxymethyl dextran.

We prepared two beta-lactoglobulin (beta-LG)-carboxymethyl dextran (CMD) conjugates (Conj. 10A and Conj. 10B) by using a water-soluble carbodiimide to decrease the immunogenicity of beta-LG. The molar ratios of beta-LG to CMD in the conjugates were 5:1 (Conj. 10A) and 2:1 (Conj. 10B). The beta-LG-CMD conjugates maintained the retinol-binding activity of native beta-LG. Intrinsic fluorescence study indicated that shielding of the surface of beta-LG by CMD occurred in each conjugate, which was eminent in Conj. 10B. A local conformational change around (125)Thr-(135)Lys (alpha-helix) in each conjugate was detected by ELISA with monoclonal antibodies. The denaturation temperature of beta-LG evaluated by differential scanning calorimetry was greatly enhanced in each conjugate. The anti-beta-LG antibody response was markedly reduced after immunization with the beta-LG-CMD conjugates in BALB/c, C57BL/6, and C3H/He mice. We determined the B cell epitopes of beta-LG and each conjugate recognized in these mice and found that the linear epitope profiles of the beta-LG-CMD conjugates were similar to those of beta-LG, while the antibody response for each epitope was dramatically reduced. The reduced immunogenicity of beta-LG was most marked in the case of Conj. 10B, which contained more CMD than Conj. 10A, and was effectively shielded by CMD. We concluded that masking of epitopes by CMD is responsible for the decreased immunogenicity of the beta-LG in these conjugates.

Animals↗
PubMedDate not supplied

Cloning and sequence analysis of cDNA encoding a precursor for human atrial natriuretic polypeptide.

Recent identification of natriuretic-diuretic activity in peptides isolated from human and rat atrial tissue implicates them in the control of extracellular fluid volume and electrolytic homeostasis. The presence of multiple forms of the peptides ranging from 3,000 to 13,000 molecular weight (MW) suggests they may all derive from the same precursor. The established amino acid sequence of alpha-human atrial natriuretic polypeptide (alpha- hANP ), a 28-residue peptide with potent natriuretic activity, provided the means to elucidate the structure of the precursor for alpha- hANP and the gene encoding it. Here we report the cloning and sequence analysis of the cDNA of human atrial mRNA encoding a precursor of alpha- hANP . The cDNA encodes gamma-human atrial natriuretic polypeptide (gamma- hANP ) of 13,000 MW, whose C-terminal 28 amino acid residues may be processed as alpha- hANP .

Amino Acid Sequence↗
PubMedDate not supplied

Identification of rat gamma atrial natriuretic polypeptide and characterization of the cDNA encoding its precursor.

Diuretic and smooth muscle-relaxing peptides, designated atrial natriuretic peptides (ANPs), have been identified in human and rat atrial tissues and implicated in the control of fluid volume and vascular function. Recently, cDNAs encoding the human and rat ANP precursors have been sequenced. We previously isolated from human tissue a natriuretic peptide of molecular weight (MW) 13,000 (gamma-hANP) comprising 126 amino acid residues, the largest natriuretic peptide so far identified, and showed that it is directly derived from the 151-residue human ANP precursor by the removal of a signal peptide. We now report the isolation and sequence analysis of a novel rat atrial natriuretic peptide (gamma-rANP) of MW 13,000, which derives from the rat ANP precursor. We also report the molecular cloning and nucleotide sequence analysis of the cDNA of the 152-residue rat ANP precursor, which is remarkably similar to the human 151-residue precursor (pre-hANP) except at the C-terminus. Differences in the rat and human precursor nucleotide sequences around the termination codons lead to a difference in processing pattern.

Amino Acid Sequence↗
PubMedDate not supplied

Structural identification of beta- and gamma-human atrial natriuretic polypeptides.

Atrial natriuretic polypeptides (ANPs) of varying chain length have been identified recently in human and rat atrial tissue. Their potent natriuretic-diuretic activities indicate their key role in the regulation of extracellular fluid volume and electrolyte balance. Furthermore, human and rat cDNAs encoding their precursor have been cloned and identified. Natriuretic-diuretic activity in human atrial extract comprises three distinct components (alpha, relative molecular mass (Mr) approximately 3,000; beta, Mr approximately 6,000; gamma, Mr approximately 13,000). However, only the 3,000-Mr peptide, alpha-human atrial polypeptide (alpha-hANP), comprising 28 amino acids, has so far been identified. We report here the purification and sequence analysis of two novel hANPs of higher Mr, beta- and gamma-hANP, both of which exhibit natriuretic and hypotensive activity. gamma-hANP, composed of 126 amino acids, carries the alpha-hANP sequence at its carboxy terminus. The identification of gamma-hANP reveals that the peptide, being the largest form of hANP, is processed directly from a 151-residue precursor by removal of a 26-residue signal peptide. In contrast, beta-hANP (56 residues) comprises an anti-parallel dimer of alpha-hANP; such a dimeric peptide possessing bioactivity has never been found in the tissue as an endogenous entity.

Amino Acid Sequence↗
PubMedDate not supplied

Coexistence of lymphoblastic and monoblastic populations with identical mixed lineage leukemia gene rearrangements and shared immunoglobulin heavy chain rearrangements in leukemia developed in utero.

Congenital leukemia often provides insight into mechanisms of in utero leukemogenesis. A 10-day-old boy with clinical features of skin nodules, marked hepatosplenomegaly, and subcutaneous bleeding received a diagnosis of congenital leukemia. This patient initially had a dominant B progenitor lymphoblast population and minor monocyte component. Treatment with prednisolone, vincristine, and doxorubicin resulted in a loss of lymphoblast population and a rapid increase and dominance of the monocyte component within 10 days. Complete remission initially was obtained with additional combination chemotherapy with epipodophyllotoxin (VP-16) and cytosine arabinoside (Ara-C), but relapse characterized by a lymphoblastic population in the bone marrow was subsequently observed. The authors hypothesize that the leukemic cells originated from a common B-monocyte lineage stem cell during fetal hematopoiesis.

Gene Rearrangement↗
PubMedDate not supplied

Cardioprotective effect of edaravone against ischaemia-reperfusion injury in the rabbit heart before, during and after reperfusion treatment.

The free radical scavenger edaravone is able to stimulate prostacyclin release and inhibit the lipoxygenase pathway in the arachidonic acid cascade. The effect of edaravone administration on myocardial damage in rabbit hearts subjected to ischaemia-reperfusion was examined at different times relative to reperfusion. All rabbits underwent sustained coronary artery occlusion for 30 min followed by 3 h of reperfusion. Rabbits were divided into the following groups: control; early (3 mg/kg edaravone IV 10 min before reperfusion); immediate (3 mg/kg edaravone IV immediately after the start of reperfusion); and late (3, 6 or 10 mg/kg edaravone IV 5 min after the start of reperfusion). Single bolus administration of edaravone 10 min before reperfusion or immediately upon initiation of reperfusion appears to be associated with reductions in infarction size and the percentage of apoptotic cells, but treatment with edaravone 5 min after initiation of reperfusion does not appear to have this protective effect.

Animals↗
PubMedDate not supplied

Superselective embolization for bleeding from duodenal diverticulum: a case report.

Duodenal diverticulum is a well-known pathological entity. The majority of patients with this condition are asymptomatic. Although hemorrhage has been described, it is an infrequent complication. We report a patient who presented with massive upper gastrointestinal bleeding with hypovolemic shock, originating from a duodenal diverticulum. The diagnosis was made by emergency angiography. Superselective arterial embolization was performed with a successful outcome. To the best of our knowledge, superselective embolization for hemorrhage originating from a duodenal diverticulum has not previously been described in the literature.

Angiography↗
PubMedDate not supplied

Serine proteinase activation in esophageal cancer.

BACKGROUND: Activation of the plasminogen/plasmin system seems to contribute to tumor aggressiveness and shorter post-operative survival. In the present study we examined the relation of uPA (urokinase plasminogen activator), uPAR (uPA receptor) and PAI-1 (plasminogen activator inhibitor type 1) to the biological growth behavior of esophageal cancer, as well as their influence on survival in esophageal cancer. MATERIALS AND METHODS: The expression and distribution of uPA, uPAR and PAI-1 were analyzed by Northern blot analysis and immunostaining in 41 resected esophageal cancers and in normal esophagi. RESULTS: Northern blot analysis revealed a 5.0-, 3.6- and 5.4-fold increase in uPA, uPAR, and PAI-1 mRNA levels in esophageal cancer, respectively, in comparison to normal controls (p<0.01). These mRNA moieties were concomitantly increased in 86% of the tumors. uPA activity was 2.3-fold increased in esophageal cancer compared with normal controls (p<0.01). Statistical analysis revealed no differences in uPA, uPAR and PAI-1 immunoreactivity between well-differentiated, moderately-differentiated and poorly-differentiated tumors. Furthermore, survival analysis showed no difference in patients whose tumors exhibited positive uPA and uPAR immunostaining (median 11 months, range 4-36 months) versus patients whose tumors exhibited negative uPA and uPAR immunostaining (median 11 months, range 3-51 months). CONCLUSION: Our data revealed that overexpression of uPA, uPAR and PAI-1 is often present in human esophageal carcinomas. However, up-regulation of these factors is not correlated with tumor differentiation or survival. These findings indicate that, unlike other tumors, uPA, uPAR and PAI-1 seem not to be prognostic markers for esophageal carcinomas.

Adenocarcinoma↗