Biomedical subjects

H Hayashida

Publications and source records attributed to H Hayashida.

At least 37 records · Page 2Linked to original sources

PubMed1997

Pelvic nerve stimulation-induced pressor responses in corpus cavernosum of anesthetized dogs.

To analyze the mechanism of penile erection and pathogenesis of impotence, pressures in the corpus cavernosum in anesthetized dogs were measured. Pelvic nerve stimulation produced pressor responses in a frequency-dependent manner. Intravenous injections of NG-nitro-L-arginine, a nitric oxide (NO) synthase inhibitor, dose dependently attenuated the response, and the inhibition was reversed by intravenous injection of L-arginine but not of D-arginine. The response was also inhibited by NG-nitro-L-arginine injected into the corpus cavernosum, the potency being approximately 10 times of that applied intravenously. The intracavernous injection of L-arginine restored the response. NG, NG-dimethylarginine, an endogenous NO synthase inhibitor, dose dependently attenuated the stimulation-induced response, which was restored by an intracavernous injection of L-arginine. An intravenous injection of hexamethonium abolished the pressor response to nerve stimulation, whereas phentolamine and atropine did not significantly alter the response. These findings suggest that an increase in intracavernous pressure caused by pelvic nerve stimulation in anesthetized dogs is mediated by NO liberated from postganglionic neurons that originate in the ganglion located in the vicinity of corpus cavernosum.

Animals↗

PubMed1997

[Hemo-lymphangioma of the scrotum: a case report].

A 3-year-old boy was referred because of a painless mass in the left scrotum. On palpation, the mass was discriminated from the testis, epididymis and spermatic cord and showed transillumination. A part of the mass was dark purple in color. Total surgical excision of the mass was performed. The lesion was multicystic (2-15 mm), adherent to the scrotal skin, and easily dissectable from the testicle. Pathological examination revealed lymphangioma as a major component and hemangioma as a minor part. He has been free of recurrent disease for 2 years. This is the 7th case of hemo-lymphangioma of the scrotum in the Japanese literature.

Child, Preschool↗

PubMed1996

Molecular analysis of a new insertion sequence from Actinobacillus (Haemophilus) actinomycetemcomitans FDC Y4.

We have found a new insertion sequence (IS), designated ISAa1, downstream of the S10 operon in Actinobacillus (Haemophilus) actinomycetemcomitans FDC Y4. ISAa1, the first IS element characterized in this organism, is 705 bp long and lacks terminal inverted repeats. This element displayed significant homology with IS200. Hybridization patterns of genomic DNA of seven A. actinomycetemcomitans strains with an internal ISAa1 probe varied depending on the serotypes, suggesting that ISAa1 might be a useful tool for epidemiological studies.

Aggregatibacter actinomycetemcomitans↗

PubMed1996

Bulky transitional cell carcinoma of bladder with inverted proliferation.

Two women, aged 51 and 62 years, had unusual transitional cell carcinomas of the urinary bladder which were > 5 cm and had a structural resemblance to inverted papilloma or Brunn's nest. They were treated by bladder-preserving surgery with no evidence of recurrence after 30 and 103 months follow-up, respectively. Our cases show some hitherto unrecognized aspects of transitional cell carcinoma with inverted proliferation because the tumors are usually found in males and tend to be aggressive.

Carcinoma, Transitional Cell↗

PubMed1996

Comparison of neurogenic contraction and relaxation in canine corpus cavernosum and penile artery and vein.

Functional roles of autonomic efferent nerves were compared in the isolated canine corpus cavernosum, penile artery and penile vein that participate in the penile erection by changing blood distribution. Nicotine produced moderate contraction in the arterial strips, but only a slight or no contraction in the corpus and venous strips. The contraction was suppressed or reversed to a relaxation by prazosin. Under alpha 1-adrenoceptor blockade, relaxations induced by nicotine were in the order of the corpus > artery > > vein. The response was abolished by NG-nitro-L-arginine (L-NA) and restored by L-arginine. The responses to nicotine and exogenous nitric oxide (NO) were abolished by oxyhemoglobin. The relaxant response to transmural electrical stimulation at 5 Hz was greater in the corpus than venous strips treated with prazosin, and it was abolished by L-NA. Contractions caused by nicotine under treatment with L-NA were greater in the artery than in the vein and corpus. Histochemical studies demonstrated nerve fibers containing NO synthase and tyrosine hydroxylase immunoreactivity in the corpus cavernosum, artery and vein. It is concluded that the canine corpus cavernosum, penile artery and penile vein are innervated by adrenergic, vasoconstrictor and nitroxidergic, vasodilator nerves; neurogenic vasodilatation is predominant in the corpus muscle, whereas neurogenic vasoconstriction predominates in the artery. Such a different functioning of the nerves may be responsible for the penile erection.

Adrenergic alpha-Antagonists↗

PubMed1996

Neurogenic nitric oxide mediates relaxation of canine corpus cavernosum.

PURPOSE: The aim of the present study is to analyze mechanisms underlying neurogenic relaxation of the corpus cavernosum which are believed to participate in penile erection. MATERIALS AND METHODS: Mechanical responses to nerve stimulation by electrical pulses and nicotine were measured in strips of canine corpus cavernosum precontracted with phenylephrine. Cyclic guanosine monophosphate (GMP) contents in the strips were also measured by radioimmunoassay. Immunohistochemistry for nitric oxide synthase (NOS) and vasoactive intestinal polypeptide (VIP) was performed. RESULTS: Transmural electrical stimulation and nicotine produced relaxations in the isolated canine corpus. The neurogenic relaxation was abolished by N omega-nitro-L-arginine, a NOS inhibitor, and the inhibition was reversed by L-arginine. Relaxations induced by nerve stimulation and exogenous nitric oxide (NO) were depressed by oxyhemoglobin and methylene blue. Vasoactive intestinal polypeptide (VIP)-induced relaxations were not influenced by these inhibitors. In the controls strips and those made unresponsive to VIP by its repeated application, the responses to nerve stimulation did not differ. The content of cyclic GMP in the tissue increased in response to nicotine, the effect being abolished by the NO synthase inhibitor. Immunohistochemical study demonstrated neurons containing NOS and VIP. CONCLUSIONS: It appears that the relaxation induced by nerve stimulation is mediated solely by NO liberated from the nerve that activates soluble guanylate cyclase and increases the production of cyclic GMP in smooth muscle, whereas VIP does not play a role in the regulation of muscle tone under the experimental conditions used.

Animals↗

PubMed1995

Interleukin-1 receptor antagonist modifies the changes in vital organs induced by acute necrotizing pancreatitis in a rat experimental model.

OBJECTIVE: Interleukin-1 (IL-1) is a mediator in some critical conditions such as septic shock and multiple organ failure. Acute pancreatitis is one of the noted causes of multiple organ failure but the mechanism by which local inflammation progresses to systemic disease is unknown. In this study, we used an IL-1 receptor antagonist (IL-1ra) to investigate whether multiple organ failure due to acute pancreatitis is mediated by IL-1, as in other causes such as severe infection, trauma, and major surgery. DESIGN: Prospective, randomized, controlled trial. SETTING: Research laboratory of a university medical school. SUBJECTS: Specific pathogen-free male Wistar rats weighing 200 to 250 g. INTERVENTIONS: Necrotizing pancreatitis was induced by retrograde injection of deoxycholate solution into the biliopancreatic duct. IL-1ra was injected intravenously at a dose of 10 mg/kg 15 mins before induction of acute pancreatitis and then infused continuously at a rate of 5 mg/kg/hr for the following 24 hrs. MEASUREMENTS AND MAIN RESULTS: Although treatment with recombinant human IL-1ra did not affect the degree of local pancreatic insult, it significantly reduced mortality, improved urine output as an indicator of the state of shock, and ameliorated the accumulation of neutrophils into the lung in a rat experimental pancreatitis model. CONCLUSIONS: We concluded that multiple organ failure in severe pancreatitis is mediated, at least in part, by IL-1 through the activation of neutrophils. Furthermore, we concluded that circulatory collapse may also be important in the mechanism of the lethal effect of pancreatitis.

Acute Disease↗

PubMed1995

Interleukin 10 reduces mortality from severe peritonitis in mice.

Interleukin 10 (IL-10) is known to suppress the induction of proinflammatory cytokines such as tumor necrosis factor (TNF) and IL-1 and is itself induced by monocytes and macrophages during sepsis. We studied the therapeutic efficacy of IL-10 by testing its effect on the survival rate in the murine cecal ligation-and-puncture (CLP) model. Administration of 1 microgram or more of recombinant murine IL-10 6 h after induction of sepsis decreased lethality in septic mice significantly and also suppressed the elevation of circulating TNF after sepsis. However, treatment with the same dose of IL-10 simultaneously or 6 h before induction of CLP had no effect on survival, and treatment with anti-TNF antibody after induction of CLP had no effect on the survival rate. These data suggest that cytokine modulation with IL-10 is a potential candidate for the treatment of sepsis and sepsis-related multiple organ failure.

Animals↗

PubMed1995

Changes in serum granulocyte colony-stimulating factor (G-CSF) and interleukin 6 (IL-6) after surgical intervention.

To evaluate the physiological role of G-CSF following surgery, we measured the serum levels of immunoreactive IL-6 and G-CSF sequentially in nine patients after major elective thoracoabdominal surgery for esophageal carcinoma. Both G-CSF and IL-6 levels reached their maxima at the first postoperative day and decreased thereafter. There was a significant correlation between serum G-CSF (y) and IL-6 (x) levels (y = 3.273x + 3.991; r = 0.787, n = 78, p < 0.001). In the case that developed aspiration pneumonia and ARDS at the second postoperative day, the measured G-CSF level was less than half the predicted value. The relationship between serum G-CSF and IL-6 levels supports the central role of G-CSF as the host defense response modifier and, thus, low G-CSF levels in the circulation is one reason for the immunodeficient state after major surgery.

Aged↗

PubMed1994

Cloning and sequencing of the groESL homologue from Porphyromonas gingivalis.

The homologue of groESL from Porphyromonas gingivalis was cloned and sequenced. Nucleotide sequencing suggested an operon containing two open reading frames (ORFs) homologous to groESL operon of Escherichia coli. The upstream ORF consisted of 267 bp corresponding to 89 amino acid residues. The downstream ORF consisted of 1635 bp corresponding to 545 amino acid residues.

Amino Acid Sequence↗

PubMed1994

Recent translocation of variable and diversity segments of the human immunoglobulin heavy chain from chromosome 14 to chromosomes 15 and 16.

We studied the organization and origin of three orphon regions, VH-F, D5-a, and D5-b, of the human immunoglobulin heavy-chain gene using yeast artificial chromosomes. VH-F and two D5 regions were mapped to chromosome bands 16p11 and 15q11-q12, respectively, by using human/rodent somatic cell hybrids and fluorescence in situ hybridization. No D5 segments were found on chromosome 14, in contradiction to previous reports. The VH-F region consists of 7 VH segments and encompasses 160 kb of DNA. A cluster of VH segments homologous to the VH-F region orphons was found in the region 245-430 kb (V2-26 to V3-11) upstream of the JH cluster on chromosome 14. Comparison of VH sequences between the VH-F and the chromosome 14 loci indicates that the translocation of the VH-F region took place, at the earliest, 20 x 10(6) years ago. The D5-a and D5-b regions were obtained in two independent contigs. The former contains only D segments in 140 kb of DNA, while the latter carries 3 VH segments downstream of D segments in 110 kb of DNA. V54, one of these VH orphon segments, is about 95% homologous to V1-18, which is located within the putative ancestor of the VH-F region on chromosome 14. Furthermore, the region detected by two DNA probes flanking the V54 segment was found only in the proximity of V1-18 within the 0.8-Mb VH region on chromosome 14. These results suggest that the two orphon loci on chromosomes 15 and 16 may have been translocated simultaneously.

Animals↗

PubMed1994

Comparison and evolution of human immunoglobulin VH segments located in the 3' 0.8-megabase region. Evidence for unidirectional transfer of segmental gene sequences.

Nucleotide sequences of 64 VH segments within the 3' 0.8-megabase region of the human immunoglobulin germ line VH locus were compared with trace evolution of human VH segments. Based on alignment of the deduced amino acid sequences of 37 functional germ line VH segments, a phylogenetic tree was generated using the neighbor-joining method. The phylogenetic tree clearly supports the previous classification of human VH segments into six families, which correlate roughly with mouse VH families with varying conservation. The human VH-III family is most homologous to mouse VH segments, suggesting that members of the VH-III family may be conserved by some functional constraint. The 5'-flanking region of each family has a family-specific structure. The sequenced 64 VH segments include 31 pseudogenes, of which 24 were highly conserved. Unidirectional transfer of segmental sequences was identified within the VH-III and VH-IV families, providing clear examples of germ line gene conversion. Such gene conversion may contribute to conserve structures of pseudo-VH segments. Comparison of the VH-IV family members indicates that recent repeated duplications and frequent gene conversions are responsible for strong conservation of this family, although functional selection is not completely excluded.

Amino Acid Sequence↗

PubMed1994

Protective effect of recombinant neutrophil elastase inhibitor (R-020) on sepsis-induced organ injury in rat.

Severe inflammatory responses after major surgeries, trauma, and infection develop multiple organ dysfunction. In the mechanisms of the pathogenesis of these responses, activated neutrophils are thought to be important in terms of their ability to produce various kinds of proteinases, which can degrade various proteins constructing human tissues. Among their proteinases, neutrophil elastase is the strongest serine proteinase secreted from activated neutrophils. Thus, we examined in this study the inhibitory effect and therapeutic efficacy of newly produced recombinant human Kunitz-type proteinase inhibitor (R-020), which coded the second domain of human urinary trypsin inhibitor. R-020 was effective in significantly improving the survival rate after induction of the rat lethal peritonitis model (cecal ligation and puncture-induced septic shock model). We suggest that various serine proteinases are implicated in the pathogenesis of neutrophil-related multiple organ failure and that recombinant human Kunitz-type proteinase inhibitor might be effective in the treatment of these kinds of organ dysfunction.

Amino Acid Sequence↗

PubMed1994

[Endopyelotomy for ureteropelvic junction obstruction: results and complications].

We treated eleven cases of primary ureteropelvic junction obstruction with percutaneous endopyeltomy. Endopyelotomy was successful in nine of the eleven cases. Complications during and after endopyelotomy occurred in three cases, two of which had pyelonephritis and the other severe postoperative hemorrhage requiring blood transfusion due to incision of a posterior crossing vessel. In this last case, the kidney was supplied by three arteries. The lower segmental artery passed behind the ureter. We emphasized that angiography should be performed to rule out the presence of a posterior crossing vessel before endopyelotomy, when it is doubtful if an extrinsic cause of ureteropelvic junction obstruction is present.

Adolescent↗

PubMed1993

The complete murine immunoglobulin class switch region of the alpha heavy chain gene-hierarchic repetitive structure and recombination breakpoints.

A 7255-base pair (bp) sequence, including the previously sequenced murine segments of I alpha, S alpha, and C alpha, has been completed. Homology matrix comparison revealed a switch repetitive region of 4.2 kilobases (kb) composed of 20-80-bp homology runs, including the previously assigned S alpha region. We distinguished several stretches of duplication, i.e. the central 0.8-kb repetitive region, with some 80-bp staggered consensus repeats containing 20-30-bp subsets, made up of the primordial pentamers CTG(A/G)G. All the break-points of the S alpha switch recombination, including those generated by the translocation of the c-myc protooncogene and those catalyzed by bacterial extracts, are located within the consensus sequence subsets of the 4.2-kb repetitive region.

Animals↗

PubMed1993

Cronkhite-Canada syndrome associated with colon cancer: report of a case.

A 68-year-old man with the clinical features of Cronkhite-Canada syndrome developed cancer of the ascending colon. Although Cronkhite-Canada syndrome has always been considered a benign condition, it may be a premalignant disorder, as suggested by the clinical course of the patient whose case is described herein.

Adenocarcinoma, Mucinous↗

PubMed1992

Interchromosomal gene conversion as a possible mechanism for explaining divergence patterns of ZFY-related genes.

The divergence pattern of mammalian ZFY-related genes from human (ZFY and ZFX) and mouse (Zfy-1 and Zfx) was reexamined on the basis of nucleotide substitutions at the synonymous codon-alternating positions. It is possible to explain the unusual divergence pattern of the mammalian Y-linked ZF genes by interchromosomal gene conversion by X-linked ZF genes. Furthermore, the rates of evolution of mammalian X- and Y-linked ZF genes were shown to agree well with those expected from our model.

Animals↗

PubMed1992

Similarity, in molecular structure and function, between the plant toxin purothionin and the mammalian pore-forming proteins.

Many proteins containing domains of a cysteine-rich repeated motif, such as epidermal growth factor (EGF), have been reported. Here we report strong similarity between the amino acid sequence of a plant toxin--i.e., purothionin and its homologues--and with those of a domain found in mammalian pore-forming cytoplasmic proteins: components of complement and perforin of cytotoxic T-lymphocytes or natural killer-like cytotoxic cells. These similar sequences were found to be identical to the so-called EGF-like cysteine-rich repeated motif itself. Electron-microscopic observations indicated that, like complement and perforin, purothionin forms pores in the cytoplasmic membrane of target cells, resulting in their death within a few hours. On the basis of these sequence comparisons and physiological functions, we propose a scheme for the evolution of proteins containing modules of the cysteine-rich repeat motif.

3T3 Cells↗