Genital tract development in peripubertal female CD IGS rats.
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Aging↗
Biomedical subjects
F Kato
Publications and source records attributed to F Kato.
Inspiration-promoting vagal reflex under NMDA receptor blockade in anaesthetized rabbits.
1. This study describes a novel vagal respiratory reflex in anaesthetized rabbits. In contrast to the well-known inspiratory (I) off-switching by vagal afferent excitation, this vagal reflex initiates and maintains the central I activity of phrenic nerve discharges in rabbits pre-treated with antagonists of N-methyl-D-aspartate-type excitatory amino acid receptors (NMDA-Rs). 2. Under NMDA-R blockade with either dizocilpine (0.025-0.3 mg kg-1), D-2-amino-5-phosphonopentanoic acid (AP5, 0.5-1 mg, i.c.v.) or ketamine (10 mg kg-1), vagal stimulation at low frequencies (5-40 Hz) during the I phase prevented or markedly delayed the spontaneous I termination. In contrast, stimulation of the same vagal afferent at the same intensity but at a higher frequency (100-160 Hz) during the I phase immediately terminated the I phase. 3. In non-vagotomized rabbits, maintaining the tidal volume at end-expiratory levels during the I phase prevented spontaneous I termination and maintained apneusis after NMDA-R blockade with dizocilpine. 4. Brief stimulation of vagal afferents at low frequency (5-40 Hz) during the expiratory (E) phase constantly initiated phrenic I discharge after NMDA-R block. 5. We conclude that low-frequency discharge of vagal pulmonary stretch receptor afferents, as when lung volume is near functional residual capacity, promotes central I activity under NMDA-R blockade.
Anesthesia↗
Nonpeptide small-molecular inhibitors of dipeptidyl peptidase IV: N-phenylphthalimide analogs.
A novel series of nonpeptide small-molecular dipeptidyl peptidase IV (DPP-IV) inhibitors with an N-phenylphthalimide skeleton has been developed. Some of the compounds, including 4-amino-(2,6-dimethylphenyl)phthalimides (7), 4- and 5-hydroxy-(2,6-diethylphenyl)phthalimide (11 and 14), 4-hydroxy-(2,6-diisopropylphenyl)phthalimide (12), and thiocarbonyl analogs of (2,6-diisopropylphenyl)phthalimide and their 4,5,6,7-tetrafluorinated derivative (18, 19 and 20), were more potent than the well-known DPP-IV-specific inhibitor, Pro-boroPro (PBP). Among them, 18 was revealed to be a DPP-IV-specific inhibitor, while the others also showed inhibitory activity toward another peptidase, aminopeptidase N (APN).
Cell Line↗
Preparation and properties of novel gramicidin S analogs possessing a tri-, tetra- or pentamethylene bridge between ornithine side chains.
Gramicidin S (GS) analogs in which the Ndelta atoms of the two Orn side chains are linked by an oligomethylene bridge [-(CH2)n-; n=3-5] were prepared via the bis(p-nitrobenzenesulfonyl) derivative [Orn(NBS)2,2']GS. For comparison the nonbridged secondary amino group-containing analog [Orn(Me)2,2']GS was also prepared. 1H NMR and CD spectral analysis indicated that these analogs adopt the same beta-sheet conformation as GS. The antimicrobial activities of these analogs were very similar, but were slightly dependent on the bridge chain length, the trimethylene-bridged analog being the most potent.
Anti-Bacterial Agents↗
Pilocarpine-induced cholinergic sweat secretion compared with emotional sweat secretion in atopic dermatitis.
We studied pilocarpine-induced cholinergic sweating, emotional sweating and sympathetic reflex sweating in atopic dermatitis (AD) patients. Secreted sweat was measured both with equipment that continuously records sweat rate and with a filter paper method that measures sweat weight absorbed. Comparison of the two methods revealed that the filter paper method underestimated the sweat secretion in AD patients. While AD patients showed no significant abnormalities in emotional sweating and sympathetic reflex sweating, the duration of pilocarpine-induced sweating was prolonged. The time from the maximal sweat rate until the sweat rate fell to half of the maximal rate was significantly longer in AD patients than in control subjects. In contrast, the time from the beginning of sweat secretion until the maximal sweat rate was not significantly different between AD patients and control subjects. There was no significant difference between AD patients and control subjects in sweat volume secreted in 20 min after pilocarpine iontophoresis. In AD patients, the total sweat volume secreted after pilocarpine iontophoresis was greater than in control subjects, although not significantly. These results suggest that the system of deactivation of pilocarpine-induced sweat secretion is impaired in AD patients whereas the activation system is not altered.
Adult↗
Structure-function relationship of model Aib-containing peptides as ion transfer intermembrane templates.
Peptaibols comprise a family of peptide antibiotics with high contents of 2-aminoisobutyric acid (Aib) residues and C-terminal amino alcohols. These peptides form alpha-helical structures leading to voltage-gated ion channels in lipid membranes. In the present study, amphiphilic helical Aib-containing peptides of various chain-lengths, Ac-(Aib-Lys-Aib-Ala)n-NH2 (n = 1-5), were designed to investigate the mechanisms of the aggregation and transmembrane orientation of helical motifs in lipid bilayer membranes. Peptide synthesis was performed by the conventional stepwise Fmoc solid-phase method. The crude peptides were obtained in high yields (66-85%) with high purities (69-95%). Conformational analysis of the synthetic peptides was performed by CD spectroscopy. It was found that these peptides take on highly helical structures, and the helicity of the peptides increases with an increase in chain-length. The longest peptide, Ac-(Aib-Lys-Aib-Ala)5-NH2, self-aggregates and adopts a barrel-stave conformation in liposomes. Ac-(Aib-Lys-Aib-Ala)5-NH2 exhibited potent antimicrobial activity against Gram-positive bacteria. Patch-clamp measurements revealed that this peptide can form well-defined ion channels with a long lifetime at relatively low transbilayer potentials and peptide concentrations. For this peptide, the single-channel conductance of the most frequent event is 227 pS, which could be related to a single-state tetrameric pore.
Amino Acid Sequence↗
Potent homophthalimide-type inhibitors of B16F10/L5 mouse melanoma cell invasion.
Recently, we developed a series of novel and potent aminopeptidase inhibitors with a homophthalimide skeleton. Among them, N-(2,6-diethylphenyl)homophthalimide (PIQ-22) possesses a specific aminopeptidase-inhibiting activity more potent than that of bestatin or actinonin, as assayed in terms of hydrolysis of L-alanine 4-methylcoumaryl-7-amide (Ala-AMC) by human acute lymphoblastic leukemia MOLT-4 cells. We show here that PIQ-22 and its 2,6-dimethylphenyl derivative (PIQ-11) are more potent inhibitors of tumor cell invasion than bestatin and actinonin in a Matrigel assay using mouse melanoma B16F10/L5 cells.
Aminopeptidases↗
An antimutagenic metabolite, streptovaricin C, isolated from Streptomyces sp.
Streptomyces sp. KM1-30 was isolated from soil as a producer of antimutagens by screening with a modified Ames test. The chemical structure of the antimutagenic metabolite was identified as streptovaricin C, which is known to inhibit DNA dependent RNA polymerase from E. coli and RNA dependent DNA polymerase from RNA tumor viruses, by MS and 1H-, 13C-NMR analyses. Addition of streptovaricin C to the cultures of UV treated Salmonella typhimurium TA100 or Trp-P-2-treated S. typhimurium TA98 decreased the frequency of mutation without a decrease in viable cell counts. The effect of streptovaricin C to the mutation induced by UV and Trp-P-2 was not desmutagenic, but antimutagenic.
Actinomycetales↗
Antiangiogenic activity of tumor necrosis factor-alpha production regulators derived from thalidomide.
Recently, we developed novel tumor necrosis factor (TNF)-alpha production regulators with a phthalimide skeleton derived from thalidomide. We show here that some of these compounds are more potent inhibitors than thalidomide of angiogenesis induced by basic fibroblast growth factor in a murine angiogenesis assay.
Animals↗
Novel small molecule nonpeptide aminopeptidase n inhibitors with a cyclic imide skeleton.
A novel series of small molecule nonpeptide aminopeptidase N (APN) inhibitors with a N-phenylphthalimide or N-phenylhomophthalimide skeleton were prepared. Evaluation of their protease inhibitory activities revealed that (i) some N-phenylphthalimide analogs are potent APN inhibitors, but they are also inhibitors of another protease, dipeptidylpeptidase IV (DPP-IV), and (ii) some N-phenylhomophthalimide analogs, including 2-(2,6-diethylphenyl)-1,2,3,4-tetrahydroisoquinoline-1,3-dione (PIQ-22), are potent and specific inhibitors of APN without DPP-IV-inhibitory activity. The structure-activity relationship studies of N-phenylphthalimides and N-phenylhomophthalimides are reviewed. PIQ-22 showed potent tumor-cell invasion-inhibitory activity.
Antineoplastic Agents↗
Isolated spinal cord sarcoidosis mimicking an intramedullary tumor.
A case of cervical intramedullary sarcoidosis and its uncommon magnetic resonance imaging with contrast medium are reported. Spinal cord sarcoidosis is very rare. It is difficult to diagnose intramedullary sarcoidosis without a previous diagnosis of systemic sarcoidosis or other apparent symptom. The patient had subacute myelopathy. Contrast-enhanced images revealed intense focal enhancement of the C6-7 cervical cord. The preoperative diagnosis was an intramedullary tumor. Subtotal resection was performed after intraoperative frozen section study was interpreted as malignant lymphoma. Subsequent pathologic examination of the biopsied specimens revealed spinal cord sarcoidosis. After surgery, steroid therapy was performed, but the patient's symptoms hardly improved. Even if imaging study and intraoperative frozen section show neoplasm, the first surgery should be limited to decompressing the cord and biopsy in cases of suspected sarcoidosis.
Cervical Vertebrae↗
Detection of single-stranded cohesive ends in the genome of Bacillus thuringiensis temperate phage KK-88.
Cohesive ends (cos sites) were detected in the genome of temperate KK-88 phage in Bacillus thuringiensis after analysis of the phage DNA generated by the 3'-5' exonuclease activity of Klenow fragment of DNA polymerase I. In addition, unlike the 5'-protruding ends of coliphage lambda genome, the ends of KK-88 phage genome were found to be 3'-protruding. The restriction map of the phage genome was also constructed on the basis of position of the cos fragments.
Bacillus thuringiensis↗
Suppression of inspiratory fast rhythm, but not bilateral short-term synchronization, by morphine in anesthetized rabbit.
To better understand the involvement of opioid receptor systems in the respiratory control, effects of morphine on the high-frequency component of inspiratory nerve discharge were evaluated. The inspiratory fast rhythm in the bilateral phrenic nerve discharge of anesthetized and artificially ventilated rabbits was analyzed with power spectral and coherence functions. Morphine (0.625-10 mg/kg, i.v.) decreased the amplitude and frequency of the inspiratory fast rhythm in a dose-dependent manner via naloxone-sensitive mechanisms. In contrast, the bilateral short-time scale correlation of the phrenic fast rhythm was resistant to morphine even at a strong suppression of the respiratory activities. It is concluded that there is little influence of opioid receptor system to the neural connectivity underlying bilateral phrenic synchronization.
Animals↗
Novel potent nonpeptide aminopeptidase N inhibitors with a cyclic imide skeleton.
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CD13 Antigens↗
New radiographic projections for avulsion fractures of the lateral malleolus.
We report two new radiographic projections for evaluating avulsion fractures at the lateral malleolus. We used seven freshly amputated legs with simulated avulsion fractures and radiopaque markers to assess their value. The projections allow accurate assessment of the displacement of fragments without superimposition, and also show whether they affect the anterior talofibular or the calcaneofibular ligament or both.
Adult↗
Association of plasmid integrative J7W-1 prophage with Bacillus thuringiensis strains.
A region homologous to the genome of plasmid integrative phage J7W-1 was detected in the largest plasmid in 3 out of 22 type strains of Bacillus thuringiensis, dendrolimus (DEN), aizawai (AIZ) and indiana (IND). Phage induction by ethidium bromide observed particularly in the J7W-1 lysogen was identified in DEN and IND but not AIZ strains. The morphology of the phage induced in DEN and IND strains was identical to J7W-1, but the phage production in IND strain was lower as compared to the J7W-1 lysogen. Although the restriction analysis indicated that the prophage in DEN strain possessed a complete J7W-1 genome, modification and/or deletion had presumably occurred in AIZ and IND strains.
Bacillus Phages↗
[A case of successful hypospadias repair without infection using recombinant human granulocyte-colony stimulating factor (rhG-CSF) for idiopathic neutropenia].
A boy aged 1 year 8 months, who was referred to our hospital because of hypospadias, was followed for 17 months under a diagnosis of idiopathic neutropenia. He was given recombinant human granulocyte colony-stimulating factor (rhG-CSF) at a dosage of 37.5 micrograms/day for 2 days preoperatively. His absolute neutrophil count in peripheral blood increased to more than 500/microliter, and hypospadias repair (free graft method) was performed. RhG-CSF was administered on the first, sixth, and eleventh days after the operation, and the postoperative course was uneventful. During pediatric surgery in patients with neutropenia, appropriate administration of rhG-CSF may be useful for preventing infection.
Granulocyte Colony-Stimulating Factor↗
A ventral pontine pathway promotes rhythmic activity in the medulla of neonate mice.
We have developed in new-born mice a ventral tilted-horizontal slice preparation for pontine stimulation and recording of spontaneous respiratory-like rhythmic trains of glutamatergic excitatory postsynaptic potentials (EPSPs) in medullary neurons. Electrical stimulations (10-50 Hz for 100-500 ms) of the caudal pontine reticular formation triggered a burst of EPSPs, recycling of the rhythmic activity and persistent increase of the rhythmic behaviour. These results identify a ventral pontine pathway that promotes rhythm generating mechanisms in the medulla and probably derives from a population of lateral reticular neurons identified in the embryonic hindbrain and eliminated after inactivation of the early developmental gene Krox-20.
6-Cyano-7-nitroquinoxaline-2,3-dione↗