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F Hata

Publications and source records attributed to F Hata.

At least 37 records · Page 2Linked to original sources
PubMed2001

Effect of 1DMe, a neuropeptide FF analog, on acetylcholine release from myenteric plexus of guinea pig ileum.

Since neuropeptide FF (NPFF) is a putative neurotransmitter to exert anti-opioid activity, we examined the effects of [D-Tyr', (NMe)Phe3]neuropeptide FF (IDMe), a stable NPFF analog, on acetylcholine (ACh) release from a longitudinal muscle-myenteric plexus (LMMP) preparation of guinea pig ileum in which opioids were known to inhibit ACh release when muscarinic autoinhibition was not fully activated. In the presence of atropine, 1DMe increased spontaneous and electrical field stimulation (EFS)-evoked ACh release in a concentration-dependent manner. Naloxone also increased ACh release. The stimulatory effects of 1DMe and naloxone were not additive. In the absence of atropine, 1DMe did not affect ACh release. Morphine decreased spontaneous and EFS-evoked ACh release in the presence of 1 microM atropine. 1DMe as well as naloxone counteracted the inhibitory effects of morphine on EFS-evoked ACh release. The combination of 1DMe and naloxone was not more inhibitory than either drug alone. 1DMe had no appreciable effect on norepinephrine-induced inhibition of spontaneous and EFS-evoked ACh release. These results first demonstrated the effects of a NPFF analog on neurotransmitter release: 1DMe had a stimulatory effect on spontaneous and EFS-induced ACh release from the LMMP preparation of guinea pig ileum, probably by counteracting the inhibitory effect of endogenous opioids on ACh release.

Acetylcholine↗
PubMed2001

Origin of Ca2+ necessary for carbachol-induced contraction in longitudinal muscle of the proximal colon of rats.

The origin of Ca2+ necessary for carbachol (CCh)-induced contraction of longitudinal muscle of the proximal colon of rats was studied. CCh induced contraction of the muscle consisting of two phases, phasic and tonic phases, with a concomitant biphasic increase in [Ca2+]i. After removal of Ca2+ from the bathing solution of the colonic segments, CCh-induced contraction was rapidly inhibited; there was almost complete inhibition 1 min after the removal. Nicardipine, a blocker of voltage-dependent calcium channel, also significantly inhibited CCh-induced contraction. On the other hand, treatment of the colonic segments with thapsigargin, an inhibitor of sarcoplasmic reticulum (SR) Ca2+-ATPase, did not significantly affect the contraction except causing a slight decrease in the rate of contraction. These results suggest that Ca> entering through voltage-dependent calcium channels, but not released from SR, is essential for CCh-induced contraction of longitudinal muscle of the proximal colon of rats. This strict dependency of the CCh-induced contraction on extracellular Ca2+ was discussed in relation to the results obtained in the fundus of rats.

Aminobenzoates↗
PubMed2001

Liver segment S2 is consistently located at the dorsal side of S3 but sometimes at the right and/or caudal side of S3.

After preparing the frontal section including the origin of the left portal trunk at the hilar region, the left anatomical lobes of 111 human livers were dissected to reveal the segmental configuration based on the supplying portal vein branches. S2 was consistently located dorsal to S3. However, in contrast to the description in common textbooks for medical students, 19.8% of the specimens carried a paradoxical segmental configuration showing a "caudal and/or rightward" S2 in combination with a "cranial and/or leftward" S3 in the frontal section through the ventral part of the hilar region. The caudal and rightward cases were associated with a specific arrangement of S2 and S3 segmental stems in which the S3 stem ran relatively upward to spread over S2 or both stems ran almost horizontal, respectively. In routine diagnostic radiology, identification of S2 and S3 might sometimes be biased by the generally accepted notion that S2 should be located at the dorsal, cranial and left side of S3.

Humans↗
PubMed2001

Ramification pattern and topographical relationship between the portal and hepatic veins in the left anatomical lobe of the human liver.

Sixty-one human livers obtained from donated Japanese adult cadavers were dissected to reveal the ramification pattern of the portal and hepatic veins, and their topographical relationship in the left anatomical lobe. The segmental portal vein supplying S2 (P2) tended to form a single stem, whereas that of S3 (P3) was usually double. An intermediate branch between P2 and P3 was observed in 23.0% of livers. In spite of variation between livers, definite P2 and P3 were identified in 47 specimens. One tributary of the left hepatic vein (LHV) was usually present for drainage of S2, and two tributaries were present for S3 (sometimes also for S2 and/or S4). The latter two tributaries of the LHV and the two subsegmental branches of S3 showed three patterns of three-dimensional interdigitations. From these results, the portal vein system did not seem to have a two segmental composition (i.e., S2 and S3) in 23.0% of specimens, whereas the hepatic vein system did not have an intersegmental course in 23.4%. Thus, there were obvious limitations in using each system to determine the liver segment. Taking the overlapping cases into consideration, the left anatomical lobe of 41.0% of specimens did not seem to fit the definition of Couinaud's liver segment. In addition, four patterns of fissure vein (or scissural vein), > 5 mm in diameter at its terminal, were identified: (1) middle hepatic vein type (left median vein, 9.8%); (2) LHV type (left medial vein, 41.0%); (3) true fissure vein (3.3%); and (4) absent cases (45.9%). The former two types also suggested limitations of the hepatic vein system as an indicator of the segmental border.

Adult↗
PubMed2001

[Configuration of the liver segment observed in the frontal section including the origin of the left portal trunk at the hepatic hilum].

After preparing threparing the frontal section including the origin of the left portal trunk at the hepatic hilum, 60 human livers (35, entirely; 25, partly) were dissected to reveal segmental configuration and the supplying portal vein branches. We usually observed two combinations of segments, i.e., S2, 4, 5 and 8 or S2, 3, 4, 5 and 8, in the frontal section including the origin of the left portal trunk. However, S8 was sometimes absent in the section when S4 extended to the right and/or upper side. S2 was consistently located dorsal to S3 despite the fact that 11.7% of the specimens carried an unexpected configuration showing a "lower" S2 in combined with an "upper" S3 in the frontal section. The latter case was associated with specific S2 and S3 segmental branches maintaining horizontal courses along a common plane. S4, S5 and S8 were usually arranged from the ventral to the dorsal aspect in this order. Four types of ventral short branches originated at or near the primary portal divisions and supplied the hilar parenchyme adjacent to S4 and/or the anterior segment (S5 or S8). These ventral short branches tended to be associated with the variations of the primary division. Dissection of the liver after frontal section provided a better understanding of the segmental configuration rather than an approach from the hepatic hilum.

Aged↗
PubMed2001

Adenosquamous carcinoma of the colorectum: report of two cases.

Adenosquamous carcinomas of the colorectum are rare neoplasms. Our experience with two cases is presented in this paper. One patient, who complained of bloody stool, was found to have adenocarcinoma in the sigmoid colon. He received a laparoscopy-assisted sigmoidectomy. The histological examination revealed that the tumor was adenosquamous carcinoma. To date, he has survived six months post operatively without evidence of recurrence. The other patient, who complained of anal bleeding, was found to have rectal adenocarcinoma and received a low anterior resection. Histological examination revealed that the tumor was an adenosquamous carcinoma. He remains alive, with no evidence of recurrence, nine years post operatively. Both cases showed paracolic lymph node metastasis. Because of its very low incidence, the histogenesis, malignancy and prognosis of this disease remain unclear. Thus, further clinical and histological study of this disease entity is required.

Carcinoma, Adenosquamous↗
PubMed2000

Takayasu arteritis. Treatment and prognosis in a university center in Brazil.

The aim of this study was to evaluate the treatment and evolution of TA patients in a University Center in Brazil. This is a retrospective and descriptive study, that included all patients with TAs who attended the out-patient clinic at the Universidade Federal de Sao Palo, between 1993 and 1998. Twenty-four patients were women and 22 where white. The median age at the time of diagnosis was 27 yo. Full arteriography was performed in 28 patients and carotid duplex ultrasound plus computed tomography of aorta was done in two patients. Type I was found in 4, type II-a and type II in one case each, the type IV in 4 cases and the type V in 20 patients. Regarding the treatment only three patients with quiescent disease did not receive any medications. Twenty-seven patients (90%) received prednisone and only ten of these patients achieved disease control. Forth-eight percent of patients who received prednisone showed some side effects. Twelve patients received methotrexate associated to prednisone and 58% of them had a good response. Two patients who did not control disease activity with prednisone plus methotrexate received cyclophosphamide without good results. Some surgical procedure was performed in ten TA patients. Three patients died during the follow-up. This study showed that the majority of TA patients attended at a University Center needed association of prednisone and methotrexate to control disease activity, 30% needed some surgical procedures and that may be a cause of death in a young patient.

Adult↗
PubMed2000

Differences in mediator of nonadrenergic, noncholinergic relaxation of the distal colon between Wistar-ST and Sprague-Dawley strains of rats.

Participation of nitric oxide and vasoactive intestinal peptide (VIP) in electrical field stimulation-induced nonadrenergic, noncholinergic (NANC) relaxation of longitudinal muscle and in balloon distension-induced descending NANC relaxation of circular muscle were studied in the distal colon of Wistar-ST and Sprague-Dawley rats. The extent of the nitric oxide-mediated component was approximately 50% in longitudinal and circular muscle of Sprague-Dawley rats, whereas this component was absent in both muscles of Wistar-ST rats. The extent of the VIP-mediated component was approximately 40% in longitudinal muscle of Wistar-ST rats and circular muscle of Sprague-Dawley rats, whereas this component was absent in circular muscle of Wistar-ST rats and longitudinal muscle of Sprague-Dawley rats. In circular muscle of Sprague-Dawley rats, in which participation of both nitric oxide and VIP in the relaxation was suggested, inhibition of descending relaxation by N(G)-nitro-L-arginine (L-NOARG) together with VIP-(10-28) was similar to that by either of the antagonists, and exogenous VIP-induced relaxation was not affected by L-NOARG, but exogenous nitric oxide-induced relaxation was partly inhibited by VIP-(10-28). These results suggest a linkage of the pathways mediated by nitric oxide and VIP. In the immunohistochemical studies, nitric oxide synthase or VIP immunoreactive neurons were seen in the ganglia, primary internodal strands of the myenteric plexus and in the circular muscle layer. However, the overall appearance of immunoreactive cell bodies in the myenteric plexus and the numbers of immunoreactive fibers in the circular muscle layer appeared to be similar in Wistar-ST and Sprague-Dawley rats. These results suggest that mediators of NANC relaxation in the distal colon are different in different strains of rats, i.e., Wistar-ST and Sprague-Dawley, although no such difference was seen in immunohistochemical studies.

Animals↗
PubMed2000

Configuration of the right portion of the caudate lobe with special reference to identification of its right margin.

The configuration of the right portion of the caudate lobe (CL), and especially the exact location of its right margin, remains obscure. This study aimed to identify this right margin according to reliable landmarks suitable for use during clinical examinations and surgery: (1) the bifurcation of the right portal vein, (2) the end of the right hepatic vein, and (3) the notch on the gallbladder fossa. The plane defined by these three landmarks is called the right paracaval plane. Dissection of 55 livers demonstrated that the entire CL was usually contained within the left half of the specimen after cutting along the right paracaval plane (Type A: 65.4%, 36/55). However, its right portion sometimes extended beyond this plane into the right half of the liver (34.6%, 19/55), forming one or two islands when viewed from the paracaval plane (Types B and C). We found two separate marginal configurations among the 19 rightward extensions of the paracaval portion: a tree-like, deep protrusion (11/19) and a relatively smooth border (8/19). The present results suggest the existence of reliable landmarks that will allow a right-side limit for surgical resection of the CL to be established: (1) the right paracaval plane (60% reliability), (2) 10 mm to the right of the plane, including the terminal of the right hepatic vein (80% reliability), and (3) the widest margin, including the 30 mm to the right of the right paracaval plane, the right side running along the inferior vena cava, and the diaphragmatic surface around the end portions of the three main hepatic veins (100% reliability).

Aged↗
PubMed2000

Involvement of cyclic AMP - PKA pathway in VIP-induced, charybdotoxin-sensitive relaxation of longitudinal muscle of the distal colon of Wistar-ST rats.

The intracellular mechanism of vasoactive intestinal peptide (VIP)-induced, charybdotoxin (ChTx)-sensitive relaxation of longitudinal muscle of the distal colon of Wistar-ST rats was studied. A single pulse or 100 pulses at 10 Hz of electrical field stimulation (EFS) induced rapid transient relaxation or that with a subsequent contraction of the longitudinal muscle in the presence of atropine and guanethidine, respectively. Rp-8 bromo cAMPS, an inhibitor of cyclic AMP dependent protein kinase (PKA), at 30 microM inhibited the relaxations induced by EFS with a single or 100 pulses maximally by about 80 or 60%, respectively. It also inhibited VIP (300 nM)-induced relaxation by 82%. VIP (100 nM - 1 microM) increased the cyclic AMP content of longitudinal muscle myenteric plexus preparations obtained from the distal colon. ChTx at 100 nM almost completely inhibited 8 bromo cyclic AMP-induced relaxation of the distal segments. EFS with two or three pulses at 10 Hz induced inhibitory junction potentials consisting of two phases, rapid and subsequent slow hyperpolarization in the membrane potential of longitudinal smooth muscle cells. Rp-cAMPS, another inhibitor of PKA, inhibited the delayed slow hyperpolarization. It also inhibited the exogenously added VIP-induced hyperpolarization of the cell membrane. Thus, the present study suggests that activation of PKA via activation of VIP receptors is associated with activation of ChTx-sensitive K(+) channels in relaxation of longitudinal muscle of the distal colon of Wistar-ST rats. British Journal of Pharmacology (2000) 129, 140 - 146

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2000

Increase in participation of vasoactive intestinal peptide in relaxation of the distal colon of Wistar rats with age.

Changes in participation of vasoactive intestinal peptide (VIP) in nonadrenergic noncholinergic (NANC) relaxation of longitudinal muscle of the distal colon with age were studied in 2- to 50-week-old Wistar rats in vitro. The extent of the VIP-mediated component of the relaxation induced by electrical field stimulation (EFS) was determined by the effect of VIP(10 - 28), a VIP receptor antagonist. In 2-week-old rats, the extent of the VIP-mediated component of the relaxation was scarce, about 10%, whereas the component gradually increase with age and reached the maximum extent 66% at 50-week-old. Since our previous results suggest that VIP induces NANC relaxation via activation of charybdotoxin (ChTx, a blocker of large conductance Ca(2+)-activated K(+) channel)-sensitive K(+) channels with concomitant slow hyperpolarization in the muscle cells, we next studied whether ChTx-sensitive component and slow hyperpolarization changes with age. Extent of ChTx-sensitive component of the relaxation increased with age, showing a very similar pattern to VIP-mediated one. EFS induced monophasic inhibitory junction potentials (i.j.ps) in longitudinal muscle cells of the distal colon of 2- and 4-week-old. EFS also induced biphasic i.j.ps in many longitudinal muscle cells of 8- and 50-week-old: rapid and subsequent slow hyperpolarization. A VIP receptor antagonist selectively inhibited the slow hyperpolarization. Exogenously added VIP induced no appreciable change in the membrane potential of longitudinal muscle cells of 2-week-old, whereas it induced slight slow hyperpolarization of the cell membrane in 4-week-old and magnitude of the hyperpolarization increased with age. On the other hand, relaxant response of the longitudinal muscle to exogenously added VIP was high in younger rats. The present results suggest that the role of VIP in mediating NANC relaxation of longitudinal muscle of the Wistar rat distal colon is very little at neonatal stage, but it increases with age.

Age Factors↗
PubMed2000

A novel experimental mouse model of peritoneal dissemination of human gastric cancer cells: different mechanisms in peritoneal dissemination and hematogenous metastasis.

We established a new cell line, AZ-P7a, with high peritoneal-metastatic potential in nude mice. AZ-P7a cells were derived from the human gastric carcinoma line AZ-521, which has low capacity for peritoneal dissemination. AZ-P7a cells developed peritoneal metastasis in 11 / 14 (78.6%) mice, whereas the parental AZ-521 cells developed metastasis in 2 / 6 (33.3%) mice. The metastatic foci in the peritoneum showed essentially the same histological appearance as those induced by parental cells. The tumorigenicity and the motile activity of AZ-P7a cells were stronger than those of the parental AZ-521 cells; in contrast, adhesion to the extracellular matrix and the production of vascular endothelial growth factor by AZ-P7a cells were decreased. In fluorescence-activated cell sorter (FACS) analysis, AZ-P7a cells expressed significantly greater levels of integrins alpha2, alpha3, alpha5, alpha6 and alphavbeta5, as compared with AZ-521 cells. However, alpha1, alpha4, alphavbeta3, hCD44H, hCD44v3, hCD44v6 and hCD44v10 were not expressed in either cell line. AZ-P7a cells developed no liver metastasis when administered by the intrasplenic injection method, though the highly liver metastatic cell line AZ-H5c showed the same rate of peritoneal dissemination as that exhibited by AZ-P7a cells after intraabdominal injection. These findings suggested that the mechanism of peritoneal dissemination differed from that of hematogenous metastasis. Moreover, the latter appears to be controlled by more complex mechanisms than the former. Thus, this cell line might be useful for investigating the mechanism of peritoneal dissemination of human gastric cancer.

Adenocarcinoma↗
PubMed2000

1H-[1,2,4] oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) inhibits cyclic GMP-PKG pathway-independent nonadrenergic, noncholinergic relaxation in longitudinal muscle of the rectum of Wistar-ST rats.

Participation of the nitric oxide-cyclic GMP pathway in nonadrenergic, noncholinergic (NANC) relaxation induced by electrical field stimulation of longitudinal muscle of the rectum of Wistar-ST rats was studied by using a selective inhibitor of soluble guanylyl cyclase, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). ODQ concentration dependently inhibited the relaxation and at 10 microM, maximally inhibited it by 83%. However, results obtained with N(G)-nitro-L-arginine, L-arginine and exogenously added nitric oxide excluded the participation of nitric oxide in the relaxation. An inhibitor of cyclic GMP-dependent protein kinase (PKG) partially (39%) inhibited the relaxation. ODQ also significantly inhibited the relaxation, which persisted after the PKG inhibitor-treatment, by 85%. The results strongly suggest that ODQ inhibits the NANC relaxation in a cyclic GMP-PKG pathway-independent manner.

Animals↗
PubMed2000

Possible role of potassium channels in mu-receptor-mediated inhibition and muscarinic autoinhibition in acetylcholine release from myenteric plexus of guinea pig ileum.

It is known that mu-agonists inhibit electrical field stimulation (EFS)-evoked ACh release from longitudinal muscle myenteric plexus (LMMP) preparation of guinea pig ileum when muscarinic autoinhibition does not fully work. In the present study, the possible role of K+ channels in the mechanisms of mu-agonists-induced inhibition and autoinhibition of ACh release was studied. In the presence of atropine, which blocks the autoinhibition, non-selective K+ channel blockers, tetraethylammonium (TEA) and 4-aminopyridine (4-AP), reversed the inhibitory effect of mu-agonists, morphine and [D-Ala2, N-Me-Phe4, Gly5-ol] enkephalin, on EFS-evoked ACh release, but not that of kappa-agonist U-50,488. Apamin, iberiotoxin or glibenclamide did not affect the inhibition of ACh release by morphine. On the other hand, in the absence of atropine (under the autoinhibition working condition), 4-AP increased EFS-evoked ACh release, but atropine did not further increase ACh release in the presence of 4-AP. In contrast, although TEA did not affect EFS-evoked ACh release, atropine increased ACh release in the presence of TEA. These results suggest that the inhibitory effects of mu-agonists and muscarinic autoinhibition on the ACh release are associated with activation of different types of K+ channels in the guinea pig LMMP preparations: the former is associated with 4-AP- and TEA-sensitive K+ channels and the latter is associated with 4-AP- but not TEA-sensitive K+ channels.

4-Aminopyridine↗
PubMed2000

Mediators of nonadrenergic, noncholinergic relaxation in Sprague Dawley rat intestine: comparison with the mediators of other strains.

Participation of nitric oxide, vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating peptide (PACAP) in nonadrenergic, noncholinergic (NANC) relaxation of longitudinal muscle of various intestinal regions in Sprague Dawley rats (8-week-old) was studied in vitro. Nitric oxide was suggested to participate in NANC relaxation of every intestinal region studied. But the participation was partial and its extent varied among the regions: significant in the proximal colon and rectum, and moderate in the jejunum, ileum and distal colon. Participation of PACAP in NANC relaxation was suggested only in the distal colon, while that of VIP was not detected in any of regions. Results obtained in the present study indicate that extent of participation of nitric oxide in NANC relaxation in Sprague Dawley rat intestine is more significant than those of other strains, Wistar and Wistar-ST.

Animals↗
PubMed2000

[Weekly low-dose CPT-11 and HCFU for advanced colorectal cancer on an outpatient treatment basis].

We attempted a new outpatient treatment using weekly low-dose CPT-11 for advanced colorectal cancer patients. A 73-year-old female with para-aortic lymph node metastases from advanced rectal cancer was given outpatient treatment for more than 5 months with weekly low-dose CPT-11 and HCFU. CPT-11 was given intravenously at a dose of 20 mg/m2 on day 1 every week. On days 2-7, she was treated by oral administration of HCFU (600 mg). Her serum CEA level decreased and continued to do so for more than 5 months. The size of the para-aortic lymph node was reduced by approximately 40%. There were no adverse effects except leukopenia (grade 2). These results suggest that weekly low-dose CPT-11 and oral HCFU may be an effective therapy on an outpatient basis in cases of advanced colorectal cancer.

Adenocarcinoma↗