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Biomedical subjects

H Goto

Publications and source records attributed to H Goto.

At least 361 records · Page 20Linked to original sources

Endoscopic assessment of invasion of colorectal tumors with a new high-frequency ultrasound probe.

The present study was carried out to clarify the usefulness of and problems associated with a new ultrasound probe in the assessment of invasion of colorectal tumors. Normal colorectal wall of 23 resected specimens from colorectal cancer cases was examined in vitro with the probe. Fifty-one patients with colorectal carcinoma and 16 patients with rectal carcinoid tumor were presurgically examined using the probe via the biopsy channel of a conventional colonoscope. After endoscopic and ultrasonographic examination, 27 patients underwent endoscopic resection and 40 underwent surgical resection. The ultrasonographic findings were compared with histologic findings in all cases. Carcinomas and carcinoid tumors were visualized as an echo-poor region with the probe. The overall accuracy rate for depth of invasion was 76% (39/51) for colorectal cancer. The accuracy rates for tumors limited to the mucosa and tumors invading the submucosa were 83% and 90%, respectively; these rates were higher than those for tumors invading the muscularis propria (50%) and beyond the muscularis propria (73%). In all 16 cases of carcinoid tumor, the depth of invasion was accurately shown to be limited to the submucosa. This probe is useful to assess invasion of colorectal tumors, especially small and flat lesions limited to the mucosa or submucosa.

Adult↗

GLUT-1 glucose transporter is localized heterogeneously within the microvessels of the mouse hippocampus.

We investigated the distribution of the glucose transporter protein within the microvessels in the mouse hippocampus by immunohistochemical methods with an anti-rat brain glucose transporter 1 (GLUT-1) and confocal laser scanning microscopy. All intraparenchymal microvessels in the hippocampus showed intensive immunoreactivity and a heterogeneous distribution of GLUT-1 was seen in the microvessels. These data may suggest that glucose could be heterogeneously incorporated into the endothelial cells of the cerebral microvessels, and therefore morphological and physiological differences may be present among the endothelial cells.

Animals↗

The coexistence of esophageal submucosal tumor and carcinoma.

The coexistence of esophageal submucosal tumor and carcinoma has been reported only in very few cases up to now, and the relationship between them is unclear. To elucidate the incidence and the pathogenesis of their coexistence, endoscopy and endoscopic ultrasonography (EUS) were sequentially performed in 95 patients who were suspected of having a submucosal tumor of the esophagus. EUS revealed 83 submucosal tumors and 12 cases of extraluminal compression. Two cases of esophageal carcinoma were observed in the series. In one patient, intraepithelial carcinoma was present on a leiomyoma originating in the muscularis mucosae, and in the other patient, multiple superficial carcinomas were presented.

Aged↗

Effect of vasoconstrictive agents added to lidocaine on intravenous lidocaine-induced convulsions in rats.

BACKGROUND: Epinephrine is reported to decrease the threshold of intravenous lidocaine-induced convulsions. However, the mechanism underlying this effect is not clear. Therefore, we carried out a study to examine the role of vasopressor-induced hypertension. METHODS: Fifty-six awake Wistar rats were assigned to seven groups of eight. All groups received a continuous intravenous infusion of lidocaine at a rate of 4 mg.kg-1.min-1 until generalized convulsions occurred. The control group (group C) received plain lidocaine. The acute hypertensive groups received lidocaine with epinephrine (group E), norepinephrine (group N), or phenylephrine (group P) to increase mean arterial blood pressure (MAP) to 150 +/- 5 mmHg. Sodium nitroprusside (SNP) was added to prevent an increase in mean arterial pressure in the remaining three groups (vasopressor-SNP groups). RESULTS: The acute hypertensive groups required significantly smaller cumulative doses of lidocaine to produce convulsions compared with control (C = 41.5 +/- 2.9 > E = 24.1 +/- 2.7, N = 27.1 +/- 2.8, P = 26.7 +/- 2.5 mg.kg-1; values are mean +/- SD, P < 0.01). In addition, plasma lidocaine concentrations (C = 11.0 +/- 0.7 > E = 7.4 +/- 0.5, N = 7.9 +/- 0.6, P = 8.1 +/- 0.8 micrograms.ml-1, P < 0.01) and brain lidocaine concentrations (C = 50.9 +/- 4.5 > E = 32.6 +/- 4.2, N = 34.5 +/- 4.8, P = 37.1 +/- 4.5 micrograms.g-1, P < 0.01) were less in the acute hypertensive groups at the onset of convulsions. In the vasopressor-SNP groups, the plasma and brain lidocaine concentrations at the onset of convulsions returned to the control values, although epinephrine and norepinephrine, but not phenylephrine, still decreased cumulative convulsant doses of lidocaine significantly (P < 0.01) compared with control (E + SNP = 30.8 +/- 2.9 < N + SNP = 34.8 +/- 2.8, P < 0.01) < P + SNP = 40.2 +/- 3.0 mg.kg-1, P < 0.01). The brain/plasma concentration ratios were similar for the seven groups. CONCLUSIONS: An equal degree of acute hypertension induced by these three different vasopressors may play a role in reducing the threshold (plasma and brain lidocaine concentrations) as well as the cumulative convulsant doses associated with lidocaine-induced convulsions.

Acute Disease↗

Endosonographic evaluation of the quality of ulcer healing induced by proton pump inhibitors.

We studied 26 gastric ulcer patients who were treated with a proton pump inhibitor to evaluate the quality of ulcer healing using endoscopic ultrasonography (EUS), and we examined the relationship between ulcer recurrence and contraction demonstrated on ulcer echoes (study I). The effect of lansoprazole versus an H2-receptor antagonist on the contraction of ulcer echoes (study II) was also investigated. In study I, gastric ulcer patients who demonstrated early healing by endoscopy often had shallow Ul-II or Ul-III ulcers and small cross-sectional areas on ulcer echoes. The early contraction on ulcer echo was associated with lower rates of ulcer relapse, and might therefore be indicative of a good quality of healing. In study II, the ulcer contraction rate after 8 weeks of treatment with lansoprazole was 71.8%, significantly higher than that achieved with H2-receptor antagonists. However, the mean cross-sectional area of gastric ulcer after 8 weeks of treatment with lansoprazole was 113.9 mm2. In conclusion, although lansoprazole was suitable for initial therapy in peptic ulcer patients, the quality of ulcer healing based on EUS findings did not appear to be adequate in patients treated for the short periods of time in this study.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Antigenic and genetic characteristics of H1N1 human influenza virus isolated from pigs in Japan.

Two strains of influenza A virus were isolated from pigs in northern Japan in 1992. Serological tests showed that the haemagglutinin (HA) and neuraminidase (NA) antigens were more closely related to those of recent human H1N1 viruses than to those of swine H1N1 viruses. The HA and NA genes of isolate A/sw/Obihiro/5/92 were shown to be closely related to those of current human H1N1 viruses. Evolutionary trees constructed from nucleotide sequences showed that the HA and NA genes of A/sw/Obihiro/5/92 were apparently on a branch cluster containing human strains isolated between 1990 and 1992.

Animals↗

Effects of FK506 on an experimental model of colitis in rats.

AIM: To assess the effects of FK506, a newly developed immunosuppressant, on experimental colitis in rats. METHODS: Experimental colitis was induced by a single colonic instillation of hapten 2,4,6-trinitrobenzene sulphonic acid (TNB) in anaesthetized rats. Rats received 30 mg TNB dissolved in 0.25 mL of 50% ethanol, and were sacrificed on day 5 following 4 days dosing with FK506 (0.25, 0.5, 1.0, 2.0 mg/kg, s.c.) or vehicle. Mucosal prostanoid concentrations were determined using high performance liquid chromotography. Tissue myeloperoxidase activities were measured. The effects of FK506 on superoxide radical formation by neutrophils in both rats and humans were also estimated in vitro. RESULTS: Administration of FK506 significantly reduced the colonic damage in a dose-dependent manner. Activities of myeloperoxidase and concentrations of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), PGF2 alpha and PGE2 in colonic tissue increased significantly following induction of experimental colitis, however, FK506 did not affect these changes. FK506 reduced stimulant-induced superoxide radical formation by neutrophils in rats and humans. CONCLUSION: FK506 decreased superoxide radical generation by neutrophils, which might contribute to the lessening of colonic damage in this model.

Animals↗

Two phenotypically distinct B lymphocytes (IgMhighIgDlow and IgMlowIgDhigh) in chronic gastric ulcer in the rat.

We determined the kinetics and phenotypes of infiltrating B cells in gastric ulcer in the rat induced by gastric injection of acetic acid (day 0). Few B cells were found in the lesion in the early stages of ulceration. On day 40, two kinds of B cells with phenotypes of IgMhighIgDlowOX33 (CD45)+OX19 (CD5)- and IgMlowIgDhighOX33 (CD45)+OX19 (CD5)- were scattered in the granulation tissue of open ulcers, but not in the healed scar tissue. On day 180, those two kinds of B cells formed primary follicles in the granulation tissue of open ulcers, but were absent from the healed scar tissue. The IgMhighIgDlowOX33 (CD45)+OX19 (CD5)- B cell was considered to be identical to the marginal zone B cell of rat spleen. This phenotype of B cell might be associated with inflammatory process in chronic gastric ulcer.

Acetates↗

Effects of dietary fibre on dimethylhydrazine-induced changes in prostanoid concentrations in rat colonic mucosa.

1. This study was designed to elucidate the effects of guar gum, a dietary fibre, on changes in prostanoid contents induced by 1,2-dimethylhydrazine, a carcinogenic agent, in rat colonic mucosa. 2. Prostanoid contents were determined using high performance liquid chromatography; five prostanoids, namely 6-keto-prostaglandin F1 alpha, prostaglandin F2 alpha, prostaglandin E2, prostaglandin D2 and thromboxane B2, were detected. 3. Four subcutaneous injections of dimethylhydrazine, 60 mg/kg every 6 days, increased the mucosal concentrations of prostaglandin E2 and thromboxane B2 by approximately 50%. Other prostanoids did not change significantly throughout the experiments. 4. In rats treated with dimethylhydrazine and a fibre diet a significant increase in thromboxane B2 content was not observed, although a significant increase in prostaglandin E2 content was observed. These effects were observed in rats fed with fibre diet over 20 days but not observed in rats fed with fibre diet over 10 days. 5. From these results and the report that aspirin use at low doses is effective in the reduction of the risk of fatal colonic cancer, inhibiting thromboxane B2 synthesis by fibre diet might be involved in the protective effect against the occurrence of colonic cancer.

1,2-Dimethylhydrazine↗

Response of human gingival fibroblasts to prostaglandins.

The effects of various prostaglandins (PGs) on the functions of human gingival fibroblasts (Gin-1 cells; ATCC CRL 1292) were examined by phase-contrast microscopy, cell-counting and radioautographic experiments. Tested PGs were PGA1, PGA2, PGB1, PGB2, PGD2, PGE1, PGE2, PGF1 alpha, PGF2 alpha, PGI2, 6-keto-PGF1 alpha, 9 alpha-11 alpha-methanoepoxy-PGF2 alpha, and thromboxane (TX) B2. PGA1 and PGD2 at 30 microM caused morphological deformation of Gin-1 cells. All the PGs tested at 30 microM suppressed the proliferation of Gin-1 cells in the logarithmic growth phase. Furthermore, all the PGs tested at 10 microM suppressed DNA synthesis, collagen synthesis, and noncollagenous protein synthesis in confluent Gin-1 cells, while exerting no effect on GAG synthesis. The concentrations of PGs used are beyond those found in healthy gingiva. However, in periodontitis the local concentrations of some PGs within the gingiva are expected to be extremely elevated beyond the physiological level. These results suggest that PGs may play an important role as a negative regulator in metabolism and some pathologic gingival conditions by suppressing the functions of gingival fibroblasts.

Cell Division↗

[Quinolone-resistant mutations in Neisseria gonorrhoeae].

For 10 strains of Neisseria gonorrhoeae exhibiting decreased susceptibility to new quinolones (MIC, > or = 0.1 microgram/ml) isolated and preserved from patients with gonococcal urethritis during the period from February 1991 through January 1992. We investigated the mechanisms for development of resistance to new quinolones. After selecting 3 PCG-sensitive and new quinolone-resistant strains from among these strains, we first carried out transformation experiments of N. gonorrhoeae using a plasmid carrying the E. coli gyrA gene. We then determined the base sequence on the N. gonorrhoeae gyrA gene by PCR method. Of the 3 strains in which transformation experiments were carried out, 2 strains yielded transformants, one of which was 8 times more sensitive to norfloxacin (NFLX) than the original strain, and it was assumed that this strain has a mutation in the gyrA gene. In our study of the base sequence on the N. gonorrhoeae gyrA gene using the PCR method, both strains had the mutation of Ser 83 (TCC)-->Phe (TTC), and in addition to this mutation of Ser-->Phe, one other strain had the mutation of Asp-87 (GAC)-->Gly (GGC). This type of mutation of quinolone-resistant N. gonorrhoeae on the gyrA gene has high homology with the mutations reported for Escherichia coli and other strains and there appears to be a close correlation between the increasing frequency of use of the new quinolones in this country and the spread of such resistant strains of N. gonorrhoeae.

Drug Resistance, Microbial↗

Antigenic and genetic analyses of the hemagglutinin of influenza viruses isolated from pigs in 1993.

Three strains of influenza A virus (H3N2) were isolated from pigs in Hokkaido, Japan in 1993. The hemagglutinin (HA) antigen of the three isolates was related to that of recent H3N2 viruses of human origin. The reactivity patterns of two of the isolates (A/sw/Obihiro/1/93 and A/sw/Obihiro/2/93) with monoclonal antibodies to the hemagglutinin of A/Bangkok/1/79 strain were similar to that of the human H3N2 strain isolated in Hokkaido in 1988, while that of the other one (A/sw/Obihiro/3/93) was similar to human H3N2 strains of 1993. In the phylogenetic analysis based on the nucleotide sequences of the HA1 regions, the HA genes of the two isolates were shown to be closely related to those of human H3N2 viruses isolated between 1986 and 1988. The remaining one isolate was shown to be closely related to those of current human H3N2 viruses. We have also found serological evidence that the A/sw/Obihiro/1/93 virus is circulating extensively in Obihiro swine. It is clear from these findings that pigs were infected with the recent H3N2 influenza virus during the human epidemic and that the virus has been maintained in pigs for at least five years.

Amino Acid Sequence↗

Prevalence of antibodies to type A influenza viruses in swine sera 1990-1994.

A total of 3,120 swine sera collected for the years 1990-94 were tested for the presence of hemagglutination-inhibition (HI) antibodies against swine (H1N1) and human (H1N1 and H3N2) strains of influenza virus. No HI antibody against the swine strains was recognized during 18 months, though a slight prevalence (1.5-9.2%) of the antibodies was observed over the entire period. A wide variance in the incidence (0-26.3%) of antibodies against the human H3N2 strains was observed among the swine population.

Animals↗

[A surgically treated case of ventrally exophytic pontine glioma].

A surgically treated case of ventrally exophytic pontine glioma is reported. A 49-year-old woman, complaining of dysarthria, dysphagia and gait disturbance, was admitted to our department. Her past history included bronchial asthma. Plain skull x-p and tomography revealed destruction of the dorsum sellae and upper clivus. CT demonstrated an enhanced oval mass at the ventral side of the upper brainstem. The mass was severely compressing the brainstem dorsally. MRI revealed a low-intensity band between the tumor and the brainstem. Dynamic MRI demonstrated a pattern of rapid increasing and slow reduction. Cerebral angiogram demonstrated a paradoxical sign that pontine branches were located anterior to the basilar artery. The finding demonstrated that the tumor was an intraaxial mass. The first operation was performed by the orbitofrontomalar approach. On the trans-sylvian route, the tumor was removed partially with CUSA and neuronavigation system. Its histology was astrocytoma grade III. Radiation therapy was added. The patient's symptoms aggravated again. On the second operation, the transtemporal route with tentorial resection was chosen. Under a wide visual field, intracapsular subtotal resection of the tumor was performed. Interferon therapy was added. She was discharged to her home with no neurological deficits. Ventrally exophytic pontine glioma is very rare. Low-intensity band of MRI, a sign of extraaxial mass, was visualised in our case. On the other hand, cerebral angiogram demonstrated a paradoxical sign. This sign suggested that the tumor originated from the brainstem. With update skull base surgery and neuronavigation system, surgical therapy of ventrally exophytic pontine glioma is safe and effective.

Brain Neoplasms↗

Mobilization of peripheral blood progenitor cells by high-dose Ara C, VP-16 and recombinant human granulocyte colony-stimulating factor: factors affecting progenitor cell yields.

Forty seven patients with hematological malignancies were treated with high doses of cytosine arabinoside (Ara C; 12 g/m2) and etoposide (VP-16), followed by recombinant human granulocyte colony-stimulating factor (rhG-CSF; 50 micrograms/m2). Peripheral blood progenitor cells (PBPC) were collected during rapid leukocyte recovery using a CS-3000 blood cell separator. A blood volume of 9 liters was processed in each apheresis, with 162 apheresis procedures performed. The mean numbers of mononuclear cells (MNC) and colony-forming unit granulocyte-macrophage (CFU-GM) harvested per apheresis were 4.4 x 10(8)/kg and 142.5 x 10(4)/kg, respectively. A sufficient number of CFU-GM for engraftment (> 30 x 10(4)/kg) could be harvested by a single apheresis in 35 of 47 patients (74%). Various factors that influence the collection of progenitor cells were analyzed by univariate and multivariate analyses. The number and duration of previous chemotherapy cycles were the most significant factors affecting CFU-GM yield. In patients with malignant lymphoma, age also had an influence in addition to these two factors. MNC harvested had an impact on CFU-GM yields by univariate analysis. These observations suggest that high-dose Ara C plus VP-16 followed by G-CSF is an effective regimen for harvesting PBPC. PBPC should be collected in the early stage of first-line chemotherapy.

Adolescent↗