Search PubMed⌕ Search

Biomedical subjects

K Iguchi

Publications and source records attributed to K Iguchi.

At least 73 records · Page 4Linked to original sources
PubMed1993

Galanin analogues: agonist and antagonist.

23 galanin-related peptides were synthesized by solid phase technology or conventional solution method. The purity of the products was carefully assessed by routine analytical criteria. Using these synthetic peptides, we have investigated the effects of galanins and structurally modified galanin peptides on glucose-stimulated insulin release using the isolated perfused rat pancreas, gastrin and somatostatin release using the isolated perfused rat stomach, the neurally-evoked muscle contractions in guinea pig ileum and the C-fiber response in the isolated spinal cord of the new born rat. The results suggest that the galanin amino-terminal 1-15 sequence is crucial for its activity in the above four systems. With the goal of developing a specific antagonist of galanin, synthetic galanin (1-15) analogues [D-Thr6,D-Trp8,9]galanin(1-15)ol, and [D-Trp8,9]galanin(1-15)ol were found to be a potent antagonist for inhibitory effect of galanin on glucose-induced insulin release.

Amino Acid Sequence↗
PubMed1993

Plasma lipase, C-peptide reactivity and human pancreatic polypeptide responses after ingestion of elemental diet in patients with chronic pancreatitis.

Plasma lipase, C-peptide reactivity (CPR) and human pancreatic polypeptide (HPP) responses after ingestion of elemental diet were studied in 27 patients with chronic pancreatitis. These subjects were classified into 3 groups according to ERP findings; minimum or mild (MIP, n = 17), moderate (MOP, n = 6) and advanced (ADP, n = 4). Basal plasma lipase levels in the MIP and MOP patients were significantly higher than that in the controls (P < 0.05). Plasma CPR response (sigma delta CPR) in MIP cases were significantly higher than that in controls (P < 0.05). Also, plasma HPP (response (sigma delta HPP) in MIP cases were significantly higher than that in controls (P < 0.05). Plasma CPR and HPP responses correlated with the severity of chronic pancreatitis. Fourteen of the 17 MIP patients (82%) showed higher levels of basal lipase or sigma delta HPP in comparison to the respective normal ranges. This study suggested that the ED test may be more sensitive for detection of mild chronic pancreatitis and that it may be useful for evaluating exocrine and endocrine pancreatic functions in various stages of chronic pancreatitis.

C-Peptide↗
PubMed1993

Masticatory function in a patient with mandibular midline cleft.

Bone grafting of a midline cleft is required to allow reasonable masticatory function. However, changes in the rhythm of mastication have not been investigated before and after such bone grafting procedures. We performed bone grafting in a patient with multiple craniofacial anomalies including a midline mandibular cleft. The patient showed a marked improvement in the rhythm of mastication after repair of the midline mandibular defect. Bone grafting proved to be an effective method for securing stable occlusion with better mandibular movement.

Bone Transplantation↗
PubMed1993

The stimulatory effects and binding characteristics of PACAP27 in rat dispersed pancreatic acini.

Pituitary adenylate cyclase activating polypeptide (PACAP) is a recently isolated active peptide of the VIP (vasoactive intestinal peptide) family. Two bioactive forms, PACAP38 and PACAP27, a shorter N-terminal amidated peptide of PACAP38, have been identified. In this study, we explored the action of PACAP27 in rat dispersed pancreatic acini and the characteristics of its binding sites. PACAP27 stimulated amylase secretion and intracellular cAMP production in a dose-dependent manner. Adding 0.5 mM IBMX increased the potency of PACAP27 on the amylase secretion, but did not change the efficacy. The biological action of PACAP27 was mediated via intracellular cAMP as is also the case with PACAP38 or VIP. The time course study, however, revealed that PACAP stimulated the initial amylase secretion greater than VIP, suggesting an involvement of mechanisms other than intracellular cAMP. Binding studies using 125I-PACAP27 and 125I-VIP indicated that the binding sites for PACAP27 interacted with PACAP27 and VIP with a similar affinity. These observations suggested the presence of type II PACAP-binding sites in the normal acini of the rat pancreas which may be functionally coupled with acinar enzyme secretion.

1-Methyl-3-isobutylxanthine↗
PubMed1993

Tactile-evoked response of sensory fibers in buccal and submandibular regions of the rat.

Evoked neural responses to tactile stimulation were recorded electrophysiologically from the mechanoreceptive afferent fibers innervating the buccal and submandibular regions of Wistar rats anesthetized with sodium thiopental. Miniature probes 200 microns in diameter were used, and data analysis was performed on the mechanosensitivity of responses to tactile stimulation in the areas innervated by the mental, mylohyoid, auriculotemporal, and cervical nerves. Mechano-sensitivity of each area showed a characteristic distribution of slowly adapting (SA), rapidly adapting (RA), C-fiber (CF), and hair follicle (HF) units in individual receptive fields. The density of the SA units was high in the areas innervated by the mylohyoid and auriculotemporal nerves. The CF units were concentrated in the small dome in the area of the mylohyoid nerve and the auriculotemporal nerve, as shown by a significant response to the dynamic features of stimulation. Estimation of the current needed for tactile acuity suggests an important role of the SA fibers in the areas innervated by the auriculotemporal, mylohyoid, and cervical nerves.

Afferent Pathways↗
PubMed1992

A new glycolipid from Mycobacterium avium--Mycobacterium intracellulare complex.

From a nonpolar lipid fraction of Mycobacterium avium--Mycobacterium intracellulare complex cell mass, a new glycolipid was obtained, which was shown to be 5-mycoloyl-beta-arabinofuranosyl-(1-->2)-5-mycoloyl-alpha-ar abinofuranosyl- (1-->1')-glycerol. When examined by TLC, all the 12 strains of this species tested, including clinical isolates, were found to contain this glycolipid. But the glycolipid was not detected in Mycobacterium bovis BCG or Mycobacterium tubrculosis H37Rv.

Chromatography, Thin Layer↗
PubMed1992

[Structure-function studies of galanin].

Galanin is widely distributed in the central and peripheral nervous system and exerts a variety of physiological effects. This review briefly describes the chemical structure, tissue distribution, physiological effects, receptors and structure-function relationships of galanin. It is worth noting that the inhibitory effect of newly synthesized galanin (1-15)-ol on guinea pig ileum contractions was of the same magnitude as that of galanin. This observation gives us an important clue as to the discovery of antagonists of galanin for neural systems.

Amino Acid Sequence↗
PubMed1992

Muscle spindles in the mylohyoid muscle of rats.

The mylohyoid muscle has several functions in relation to respiration, deglutition, and phonation, but these functions are not fully understood. The interaction of the mylohyoid nerve and muscle in 25 rats was studied by neurophysiologic and histologic methods. Stretching of the muscle elicited electrical responses from the branch of the mylohyoid nerve innervating the mylohyoid muscle, and stretch-sensitive receptors were demonstrated histologically in the mylohyoid muscle. This study indicates that the mylohyoid muscle plays an active role in functions such as swallowing, breathing, and phonation.

Animals↗
PubMed1991

Structural determination of a directly mutagenic amino-nitrobiphenyl as the S9 metabolite of 2,4,2',4'-tetranitrobiphenyl in Salmonella typhimurium TA98.

In order to elucidate the mechanisms of mutagenic activation of nitrobiphenyls by mammalian activation systems, 2,4,2',4'-tetranitrobiphenyl was incubated with S9 and its mutagenic metabolites were separated by SiO2 and Al2O3 column chromatography. The most mutagenic diamino-dinitrobiphenyl was isolated from the reaction mixture of 2,4,2',4'-tetranitrobiphenyl with S9 mix at 37 degrees C for 48 h, and its mutability was 4646 revertants/50 ng in Salmonella typhimurium TA98 without S9 mix. The deamination product of this most mutagenic metabolite was identical to 2,4'-dinitrobiphenyl by gas chromatography-mass spectrometry. Therefore, the structure of the metabolite was determined as 2,4'-diamino-2',4-dinitrobiphenyl by its chemical and physico-chemical properties.

Animals↗
PubMed1991

A case report of paroxysmal nocturnal hemoglobinuria in a child.

A ten-year-old boy with paroxysmal nocturnal hemoglobinuria (PNH) is described. Although hemolytic anemia was evident, Ham's test was negative and the erythrocyte acetylcholinesterase (ACHE) activity was normal at the first admission. The diagnosis of hemolytic anemia of unknown etiology was made. Methylprednisolone pulse therapy was started, but could not prevent the hemolytic crises associated with infections. Twelve months later Ham's test turned positive and ACHE activity decreased. The diagnosis of PNH was confirmed. As the disease is insidious in onset, we emphasize that a high index of suspicion and Ham's test and sucrose water test repeated at regular intervals are required to avoid missing the diagnosis.

Acetylcholinesterase↗
PubMed1991

[Studies on 15 seropositive cases to Lyme disease using immunoperoxidase test in Japan].

The serological survey, analyzing sera which were obtained from Lyme disease suspected subjects was performed using immunoperoxidase (IP) test between July, 1987 and February, 1989. Fifteen seropositive subjects to Borrelia burgdorferi have been found in this survey, and these cases were considered to be true Lyme disease or highly suspected for this illness. Most of these seropositive cases geographically occurred in northern part of Japan, and both sexes and all age subjects were affected. In clinical manifestations, 5 cases developed a typical skin lesion of erythema chronicum migrans (ECM) followed by tick-bite. Neurologic manifestations were found in 6 cases, including one patient who also had ECM after a known tick bite. Of these neurologic manifestations, 4 cases had lymphocytic meningitis, 3 unilateral or bilateral facial palsy, and one encephalomyelitis. When 8 of these 15 sera were analyzed for antibodies to Lyme disease with ELISA, a poor agreement of serodiagnosis between IP test and ELISA has been found in the course of this study.

Adolescent↗