Biomedical subjects

H Takeuchi

Publications and source records attributed to H Takeuchi.

At least 415 records · Page 23Linked to original sources

PubMed1996

[Experimental bladder stone production by Ureaplasma urealyticum].

We examined the relationship between struvite stone formation and Ureaplasma urealyticum in male Wister rats by inoculating U. urealyticum and implanting a zinc disc into the bladder surgically. Cultures of U. urealyticum and pH measurements in urine obtained by forced urination were done on days 2 and 6 after operation. Half of the rats were killed 7 days after the operation and the remaining half 14 days after the operation. A total of 46 rats, consisting of 10 rats in the control group and 36 rats inoculated with U. urealyticum, were studied. U. urealyticum was weakly virulent, because it was not detected in the urine culture on day 2 in 10 of the 36 rats inoculated with the organism, and showed a tendency towards spontaneous elimination in the other rats. Urinary pH was elevated slightly by the presence of U. urealyticum. Struvite stones were formed in 52% of the rats by the inoculation on of U. urealyticum, and 69% and 71% of the positive rats in urine culture for U. urealyticum on day 2 and day 6 respectively. The stones tended to be larger the longer U. urealyticum was detected in urine. U. urealyticum may play a role in struvite stone formation, but not a major role.

Animals↗

PubMed1996

[Non-paralytic pontine exotropia with alternating exotropia].

We report a patient with pontine infarction who showed non-paralytic pontine exotropia (NPPE) with alternating exotropia. An 81-year old woman developed diplopia and gait disturbance. On the fourth day, she was admitted to our hospital. Oculomotor findings on admission showed that the ocular position of the left eye on forward gaze was fixed at the midline, while the right eye was abducted. When she was instructed to use the right eye for forward gaze, the left eye deviated outward. On right gaze, the left eye was not abducted and monocular nystagmus was noted in the abducted right eye. Upper gaze was limited in the right eye and convergence was not possible. The remaining ocular movements were intact. On cranial CT performed on eye closure, the left eye was abducted and the right eye was fixed at the midline. Brain MRI showed cerebral infarction located in the left paramedian portion of the middle pontine tegmentum with involvement of the medial longitudinum fasciculus (MLF) and in the ventral site of the upper pons. On the 16th day, right exotropia disappeared on eye opening without forward gaze, but forward gaze easily induced outward deviation of the right eye. On the 39th day, right exotropia on forward gaze had almost disappeared. However, left MLF syndrome and abnormal convergence were persistent when she discharged on the 76th day. In conjunction with oculomotor and neuroradiological findings, the NPPE with alternating exotropia in our patient may be due to severe MLF damage and secondary hyperactivity of the contralateral paramedian pontine reticular formation.

Aged↗

PubMed1996

Criteria for the detection of sleep-associated bruxism in humans.

Surface electromyography of the masseter and electrocardiogram recordings of heart activity during sleep were performed on nine subjects who suffer from an oral motor dysfunction (bruxism during sleep. Signals were monitored in the subject's home sleeping environment over 4 consecutive nights. A total of 36 nights of data were analyzed to perform the following: (1) describe the nature and magnitude of total masseter muscle electromyographic activity above a minimum threshold of 3% of each subject's individually established maximum voluntary contraction level; and (2) describe electrocardiograph rate changes (using the R-R interval) that occurred in relation to these electromyographic elevations. From these data, criteria for detection of bruxism events were established and combined into a fully automated event detection algorithm. The mean number and duration of the detected bruxism events are reported. The underlying logic for the criteria selected, and what effect other possible criteria would have on the separation of abnormal from normal motor events, is also presented and discussed.

Adult↗

PubMed1996

Temporomandibular dysfunction, chronic orofacial pain and oral motor disorders in the 21st century.

This article describes the various sensory and motor disorders which afflict the orofacial region. Such information is essential to the modern dentist who wishes to be proficient in the diagnosis of patients with these problems. These abnormalities are broadly separated into three groups of pathologic conditions: Temporomandibular disorders; chronic orofacial pain disorders; and oral motor disorders. Although much more can be said about each reviewed condition, this article focuses on the diagnostic features of each specific disorder within each of these 3 groups. It suggests alternate nomenclature for each disorder, where appropriate. Due to space limitations the article does not cover the procedures for management of each disorder, however, the reader is referred to appropriate references in this regard. The overall intent of the article is to help the dental practitioner recognize and differentiate the above conditions.

Chronic Disease↗

PubMed1995

Effects of dopamine on snail neurones.

The pharmacological features of dopamine receptors in identifiable giant neurone types of a snail (Achatina fulica Férussac) were studied. Under voltage clamp, two neurone types, LVMN (left ventral multiple spike neurone) and d-RPeAN (dorsal-right pedal anterior neurone), produced an inward current (Iin) in response to dopamine, (-)-noradrenaline and epinine, whereas v-LCDN (ventral-left cerebral distinct neurone) produced an outward current (Iout) in response to dopamine and epinine. Mammalian dopamine receptor agonists, fenoldopam (dopamine D1-like receptor agonist), (+/-)-SKF 38393 (1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine-7,8- diol) (D1-like), apomorphine (D2-like), (-)-quinpirole (D3 and D4) and methylergometrine showed slight or no effect. (+/-)-SKF 83566 ((+/-)-7-bromo-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benza zepine) (dopamine D1-like receptor antagonist) and (+)-UH 232 (cis-(+)-5-methoxy-1-methyl-2-(di-n-propylamino)tetralin) (D3 and D2) non-competitively inhibited the Iin of LVMN and d-RPeAN, but (+/-)-sulpiride (D2-like) was without effect. In contrast, (+/-)-sulpiride competitively inhibited Iout of v-LCDN, (+)-UH 232 non-competitively inhibited Iout of v-LCDN but (+/-)-SKF 83566 was without effect. H-7 (1-(5-isoquinolinesulfonyl)-2-methylpiperazine) (non-selective protein kinase inhibitor) inhibited Iin of LVMN and d-RPeAN, but did not affect Iout of v-LCDN. Dopamine-induced Iin was Na(+)-dependent; Iout was K(+)-dependent. Ouabain did not affect these currents. We propose that the pharmacological features of Achatina neuronal dopamine receptors are not fully comparable to those of mammals, although intracellular signal transduction systems linked with dopamine receptors may similarly exist in different animal species.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

PubMed1995

A possible retinal information route to the circadian pacemaker through pretectal areas in the hagfish, Eptatretus burgeri.

By recording the locomotor activity rhythm of hagfish, Eptatretus burgeri, in which surgical lesions of the pretectal areas were made, we searched for the route of light information from the eyes to the circadian pacemaker, which is considered to be located in the preoptic nucleus. The entrainment of circadian activity rhythm to the light dark cycle, under 12 h light/12 h dark (12L:12D) was lost in animals whose pretectum was ablated with a pair of scissors and the animals then showed a free-running rhythm. Destruction of the pretectal areas with a high-frequency lesion generator also caused a free-running rhythm under 12L:12D. These findings indicate that retinal information may entrain the circadian rhythm via the pretectal areas, which have retinofugal connections.

Animals↗

PubMed1995

Blockers for excitatory effects of achatin-I, a tetrapeptide having a D-phenylalanine residue, on a snail neurone.

Some histamine H1 receptor antagonists suppressed the inward current (Iin) of an Achatina identifiable neurone type, PON (periodically oscillating neurone), caused by an Achatina endogenous tetrapeptide having a D-phenylalanine residue, achatin-I (Gly-D-Phe-Ala-Asp), under voltage clamp. Achatin-I was applied locally to the neurone by brief pneumatic pressure ejection and antagonists were administered by perfusion. The dose-response curves of the effective histamine H1 antagonists indicated their potency order to suppress the Iin as follows: chlorcyclizine, promethazine, triprolidine and homochlorcyclizine > trimeprazine and clemastine > diphenylpyraline. The potent drugs were mostly piperazine and phenothiazine types. The effects of chlorcyclizine, promethazine and triprolidine on the dose (the duration of the pressure ejection)-response curve of achatin-I indicated that these drugs affected the Iin caused by achatin-I in a non-competitive manner. The antagonists for the receptors of the small-molecule neurotransmitters other than histamine H1, such as histamine H2, acetylcholine, gamma-aminobutyric acid (GABA), L-glutamic acid, dopamine, alpha- and beta-adrenalin and 5-hydroxytryptamine, had no effect on the Iin caused by achatin-I.

Amino Acid Sequence↗

PubMed1995

Structural modification of DNA by a DNA-binding motif SPKK: detection of changes in base-pair hydrogen bonding and base stacking by UV resonance Raman spectroscopy.

Interactions of a DNA-binding motif SPKK with polynucleotides have been investigated by uv resonance Raman spectroscopy. Analysis of the Raman spectra has shown that the tetrapeptide SPKK weakens the adenine-thymine base-pair hydrogen bonding in poly(dA-dT).poly(dA-dT) and reduces the adenine-adenine base stacking interactions in poly(dA).poly(dT), both effects being indicative of destabilization of the DNA double helical structure. On the other hand, poly(dG-dC).poly(dG-dC) and poly(dG).poly(dC) do not show any structural change in the presence of SPKK. The present observations confirm that the SPKK motif, which is frequently found in histone H1 proteins, specifically binds to A/T-rich regions of DNA and loosens the DNA double-helical structure. One of the roles of the SPKK motifs in histones may be to increase DNA flexibility so that DNA can wrap around core histones and be assembled into chromosomes more easily.

Amino Acid Sequence↗

PubMed1995

Antenatal sonographic detection of the proximal esophageal segment: specific evidence for congenital esophageal atresia.

To determine the biologic significance of a transient anechoic area observed in the midline of the fetal neck when attempting an antenatal ultrasound diagnosis of congenital esophageal atresia (CEA), a prospective study was made in 10 cases presenting both polyhydramnios and an unusually small stomach size due to a decrease in fetal stomach fluid. There were 8 cases indicating a transient anechoic area in the fetal neck, all of which were diagnosed as having CEA postnatally by plain roentgenogram, neonatal surgery, or autopsy findings. The remaining 2 cases had no CEA; one had Nager's syndrome and the other, a disorder involving neuronal migration in the central nervous system. These results suggest that an anechoic area in the middle of the fetal neck can be used as an indication of CEA and also for differentiating this condition from diseases with possible swallowing impairment.

Esophageal Atresia↗

PubMed1995

Cloning and characterization of class I Mhc genes of the zebrafish, Brachydanio rerio.

The zebrafish (Brachydanio rerio) offers many advantages for immunological and immunogenetic research and has the potential for becoming one of the most important nonmammalian vertebrate research models. With this in mind, we initiated a systematic study of the zebrafish major histocompatibility complex (Mhc) genes. In this report, we describe the cloning and characteristics of the zebrafish class I A genes coding for the alpha chains of the alpha beta heterodimer and thus complete the identification of all four classes and subclasses of the Mhc in this species. We describe the full class I alpha cDNA sequence as well as the exon-intron organization of the class I A genes, including intron sequences. We identify three families of class I A genes which we designate Brre-UAA, -UBA, and -UCA. The three families originated about the time of the divergence of cyprinid and salmonid fishes. All three families are members of an ancient lineage that diverged from another, older lineage also represented in cyprinid fishes before the radiation of teleost orders. The fish class I A genes therefore evolve differently from mammalian class I A genes, in which the establishment of lineages and families mostly postdates the divergence of orders.

Amino Acid Sequence↗

PubMed1995

Sympathetic activity is lower in rats fed a beef tallow diet than in rats fed a safflower oil diet.

Effects of dietary fats consisting of different fatty acids on sympathetic activity and body fat accumulation were studied in rats. Rats were meal-fed an isoenergetic diet based on either beef tallow or safflower oil for 8 weeks. Carcass fat content was greater (P < .05) in rats fed the beef tallow diet than in rats fed the safflower oil diet. Norepinephrine (NE) turnover rate was significantly lower (P < .05) in interscapular brown adipose tissue (IBAT) and pancreas in rats fed the beef tallow diet than in rats fed the safflower oil diet, resulting in a decreased (P < .05) diet-induced thermogenesis (DIT) and an increased (P < .05) serum insulin concentration in the former. To confirm the effects of dietary fats on sympathetic activity in relation to body fat accumulation, rats were chemically sympathectomized. Sympathectomy abolished the differences in body fat accumulation, DIT, and serum insulin concentration between the two dietary groups. These results suggest that the beef tallow diet promotes body fat accumulation by reducing sympathetic activity as compared with intake of the safflower oil diet.

Adipose Tissue↗

PubMed1995

Osteogenesis in muscle with composite graft of hydroxyapatite and autogenous calvarial periosteum: a preliminary report.

To investigate the bone forming activity of composite grafts of hydroxyapatite (HA) and autogenous calvarial periosteum, porous HA rods with or without the periosteum were implanted into the back muscle of white rabbits. They were harvested 3 and 6 months after implantation and studied histologically and microradiographically. Bone formation in the pores of HA occurred in three out of four composite implants of the 3 month group, and four out of five implants of the 6 month group. The two specimens without bone formation revealed irregular calcified tissue outside the HA implant. No formation of bone and calcified tissue took place in any of the specimens with HA alone. These results indicate the potential of this new experimental system of ectopic osteogenesis and offer the possibility of a new improved bone graft consisting of HA and autogenous periosteum.

Animals↗

PubMed1995

Suppressing effects of neuroactive peptides on the inward current caused by achatin-I, an Achatina endogenous peptide.

1. Modulatory effects of the four molluscan neuroactive peptides. FMRFamide (Phe-Met-Arg-Phe-NH2), APGW-amide (Ala-Pro-Gly-Trp-NH2), oxytocin and [SER2]-Mytilus inhibitory peptide ([SER2]-MIP) (Gly-Ser-Pro-Met-Phe-Val-NH2) were examined on the inward current (Iin) caused by achatin-I (Gly-D-Phe-Ala-Asp), which has been isolated from the Achatina ganglia. 2. Two Achatina giant neurone types, v-RCDN (ventral-right cerebral distinct neurone) and PON (periodically oscillating neurone), were used. Achatin-I was applied locally to the neurone tested by brief pneumatic pressure ejection, and the other molluscan neuroactive peptides were perfused around the ganglia. 3. FMRFamide, perfused at 3 microM, suppressed markedly the Iin elicited by the achatin-I of both v-RCDN and PON. APGW-amide at 3 microM also suppressed the Iin of v-RCDN, but did not affect that of PON. Oxytocin at 1 microM suppressed the Iin of PON, but did not affect that of v-RCDN. [Ser2]-MIP at 3 microM did not affect the Iin of v-RCDN. 4. The dose-response curves of FMRFamide, APGW-amide and oxytocin, indicated that their respective suppressive effects on the Iin of achatin-I were dose-dependent, and that APGW-amide was slightly more potent than the other peptides. The dose (pressure duration)-response curves of achatin-I (1 kg/cm2, 10(-3) M, 5 min interval), obtained by varying the duration of the achatin-I pressure ejection, were measured in the presence and absence of each of the three peptides.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1995

Further mapping of the Achatina giant neurone types sensitive to the neuroactive peptides isolated from invertebrates.

1. The effects of the 10 synthetic neuroactive peptides originally isolated from invertebrates, applied locally to the neurone tested by the brief pneumatic pressure ejection on the identifiable neurone types of Achatina fulica Ferussac were examined. 2. Achatin-1 (Gly-D-Phe-Ala-Asp), an Achatina endogenous tetrapeptide having a D-phenylalanine residue, ejected locally, showed the depolarizing effects on nearly half of the number of neurone types tested. 3. ACEP-1 (Ser-Gly-Gln-Ser-Trp-Arg-Pro-Gln-Gly-Arg-Phe-NH2), isolated originally from Achatina atria, and pedal peptide (Pro-Leu-Asp-Ser-Val-Tyr-Gly-Thr-His-Gly-Met-Ser-Gly-Phe-Ala) and buccalin (Gly-Met-Asp-Ser-Leu-Ala-Phe-Ser-Gly-Gly-Leu-NH2), found in Aplysia neurones, showed excitatory effects on some Achatina neurone types. 4. Myomodulin (Pro-Met-Ser-Met-Leu-Arg-Leu-NH2), found in Aplysia neurones, produced a hyperpolarization on nearly half of the number of Achatina neurone types tested. The two FMRFamide-like peptides, <EDPFLRFamide (<Glu-Asp-Pro-Phe-Leu-Arg-Phe-NH2), isolated from Helix heart, and AF1 (Lys-Asn-Glu-Phe-Ile-Arg-Phe-NH2), from Ascaris head, also showed hyperpolarizing effects on more than half of the number of Achatina neurone types. 5. SALMFamide 1 (Gly-Phe-Asn-Ser-Ala-Leu-Met-Phe-NH2), isolated from Asterias nervous system, CCAP (Pro-Phe-Cys-Asn-Ala-Phe-Thr-Gly-Cys-NH2), from Carcinus pericardial organ, and corazonin (<Glu-Thr-Phe-Gln-Tyr-Ser-Arg-Gly-Trp-Thr-Asn-NH2), from Periplaneta cardiac corpus, had no effect on Achatina neurones.

Amino Acid Sequence↗

PubMed1995

Effectiveness of extended lymphadenectomy in noncurative gastrectomy.

PURPOSE: We examined the efficacy of extended lymph node dissection for prolonging survival in macroscopically or histologically proven incurable gastric cancer. PATIENTS AND METHODS: We analyzed clinico-pathologic data on 119 patients with serosally invasive gastric cancer who underwent noncurative gastrectomy, with respect to the relation between the extent of lymphadenectomy and survival benefit. RESULTS: The 5-year survival rate was significantly higher among patients treated with extensive lymphadenectomy (R2/3) compared to simple gastrectomy (R1). Extensive lymphadenectomy significantly prolonged survival time even after noncurative gastrectomy in cases where there was no evidence of hepatic metastasis, peritoneal seeding, or extensive nodal metastasis beyond the tertiary lymph node, and regardless of the extent of direct invasion to adjacent organs. CONCLUSIONS: Gastrectomy combined with extended lymphadenectomy and/or resection of adjacent organs is recommended for gastric cancer patients without distant metastasis, even when the operation is histologically noncurative. Gastrectomy and perioperative intensive chemotherapy are called for when patients have distant metastasis.

Adenocarcinoma↗

PubMed1995

Effect of lymph node dissection on the prognosis in patients with node-negative early gastric cancer.

BACKGROUND: Our objective was to evaluate the long-term benefit of R2/3 lymph node dissection compared with that of R1, even in node-negative cases. METHODS: We analyzed clinicopathologic data on 373 surgically treated patients with early gastric cancer and without microscopic nodal involvement. RESULTS: Five- and 10-year survival rates for patients treated with R2/3 gastrectomy were 97.3% and 95.4%, respectively. These values were significantly higher than the 90.1% and 81.1% noted for R1 gastrectomy (p < 0.01). Although no difference was found in morbidity and mortality, the incidence of death from a recurrence of the gastric cancer was significantly higher in patients treated with R1 gastrectomy than those with R2/3. Multivariate analysis with the Cox's proportional hazard model revealed patients' age and R2/3 gastrectomy to be independent prognostic factors in patients with node-negative early gastric cancer. CONCLUSIONS: These data show that prophylactic lymph node dissection can potentially prolong the survival time of patients with node-negative early gastric cancer by preventing a recurrence of the gastric cancer.

Age Factors↗

PubMed1995

Improved static compression behaviors and tablettabilities of spherically agglomerated crystals produced by the spherical crystallization technique with a two-solvent system.

PURPOSE: Poorly compressible crystals of acebutolol hydrochloride were agglomerated by the spherical crystallization technique with a two-solvent system to improve the compressibility for direct tabletting. The mechanism of improvements in static compression behaviors and tablettabilities of the spherically agglomerated crystals were investigated. METHODS: The improvement of static compression behaviors of the agglomerated crystals was determined by measuring the stress relaxations and elastic recoveries of compressed powder of original and agglomerated crystals. The improved tablettability of agglomerated crystals was evaluated by the pressure transmission ratio upon compression, the ejection pressure for releasing the tablet from the die and the tablet strength, i.e., tensile strength required for breaking. RESULTS: The higher relaxation pressure and the lower elastic recovery of the agglomerated crystals than of the original crystals were found. The pressure transmission ratio data showed that the friction pressures of the two crystals were similar during the compression period. The ejection pressure of the agglomerated crystals was lower than that of the original crystals. The tensile strength of the tablet of agglomerated crystals was greater than that of the original crystals. CONCLUSIONS: The compressibility and tablettability of the spherically agglomerated crystals prepared by the spherical crystallization technique were much improved due to their increased plastic property and reduced adhesive property compared to the original crystals.

Acebutolol↗

PubMed1995

Diet-induced thermogenesis is lower in rats fed a lard diet than in those fed a high oleic acid safflower oil diet, a safflower oil diet or a linseed oil diet.

The objectives of the present study were to examine the effects of dietary fats differing in fatty acid composition on diet-induced thermogenesis, sympathetic activity in brown adipose tissue and body fat accumulation in rats. Rats were meal-fed for 12 wk an isoenergetic diet based on lard, high oleic acid safflower oil, safflower oil or linseed oil, and norepinephrine turnover rates in brown adipose tissue were then estimated. Whole-body oxygen consumption after the meal indicated that diet-induced thermogenesis was significantly lower in rats fed the lard diet than in those fed the other diets. The norepinephrine turnover rate in the interscapular brown adipose tissue was also significantly lower in the lard diet group than in the other diet groups. The carcass fat content was significantly higher in the lard diet group than in the other diet groups, whereas the abdominal adipose tissue weights were the same in all diet groups. These results suggest that the intake of animal fats rich in saturated fatty acids, compared with the intake of vegetable oils rich in monounsaturated or polyunsaturated fatty acids, decreases diet-induced thermogenesis by a decline of sympathetic activity in brown adipose tissue, resulting in the promotion of body fat accumulation.

Adipose Tissue, Brown↗