Biomedical subjects

K Ichimura

Publications and source records attributed to K Ichimura.

222 records · Page 13Linked to original sources

PubMedDate not supplied

Immunohistochemical localization of epidermal growth factors in mouse olfactory epithelium.

Our object was to clarify changes in epidermal growth factor (EGF) occurring in the olfactory epithelium with aging. We investigated the changes in EGF in the murine olfactory epithelium with aging by an immunohistochemical method. We examined six mice at each of the following stages: embryonal (embryonic days 14 and 16), neonatal (postnatal days 1 and 7), adult (postnatal weeks 5 and 12), and aged (postnatal years 1.5-2). The olfactory epithelium of each mouse was stained with anti-EGF polyclonal IgG using an immunohistochemical method. EGF were observed in the whole layer of the olfactory epithelium at all stages. The mesenchyme under the epithelium was stained in the embryonal stage, and the circumference of the olfactory gland cells was also stained, although weakly, in the adult stage. We believe that EGF contribute to cell proliferation, growth and turnover of the olfactory epithelium. However, the decrease in EGF was less than expected in the aged mice.

Age Factors↗

PubMedDate not supplied

H1 and H2 histamine receptors in the in vitro nasal mucosa.

The effect of histamine was studied on canine nasal blood vessels with an in vitro muscle tension measuring technique. Observations suggest that histamine has at least four different effects: 1) inhibits the contraction induced by nerve terminal stimulation, 2) relaxes the smooth muscle under sustained contraction, 3) contracts the smooth muscle, 4) enhances (nor)epinephrine-induced contraction. Both H1 and H2 histamine receptors were identified in the mucosal blood vessels of the canine nasal septum. H1 receptors were present at the surface of vascular smooth muscle and mediated the contractile response (3) due to opening calcium influx channels. H2 receptors existed at both sympathetic nerve terminals and the muscle cell membrane. Stimulation of either H2 receptor caused muscle relaxation. The presynaptic H2 receptors mediated vasodilation through the inhibition of norepinephrine release from the nerve endings. Postsynaptic H2 receptors caused direct muscle relaxation possibly through an increase in cyclic AMP. Both H1 and H2 antagonists worked well, whereas agonists did not properly produce theoretically expected results in these specimens.

Animals↗

PubMedDate not supplied

p27 expression correlates with prognosis in patients with hypopharyngeal cancer.

BACKGROUND: Hypopharyngeal cancer is closely associated with smoking, drinking, and malnutrition. Recent findings reveal that carcinogenesis depends on genetic aberrations. MATERIALS AND METHODS: Eighty-one patients with hypopharyngeal cancer were analyzed for p53, CCND1, and p27, and 72 patients were analyzed for p21, immunohistochemically. RESULTS: p53 overexpression was found in 70%, CCND1 in 17%, p21 in 29%, and p27 in 32%. The low intensity of p27 expression correlated with poor prognosis, but the level of expression of p53, CCND1, and p21 did not. CONCLUSION: The immunohistochemical analysis of p27 provides a possible tool in determining the prognosis of patients with hypopharyngeal cancer.

Cell Cycle Proteins↗

PubMedDate not supplied

Mucoceles of the paranasal sinuses with intracranial extension-postoperative course.

Mucoceles of the paranasal sinuses cause progressive distension of the bony walls and induce compressive symptoms. Although rare, cases of massive intracranial extension have occurred. We believe that an endoscopic transnasal approach is the best choice for such huge mucoceles because it is the least invasive and can provide an adequate surgical field of view for wide marsupialization. However, the results of long-term follow-up after endoscopic transnasal surgery have not been reported. This study was designed to evaluate prospectively the postoperative course of patients with intracranially extended mucocele. In the last 5 years, we have operated on four patients with intracranially extended mucocele. Although postopertive scanning is not recommended routinely after surgery for inflammatory disease, we followed up two patients who consented by using magnetic resonance imaging (MRI) along with endoscopy. Dural descent to the original skull base plane necessitated long periods of follow-up, lasting 18 and 5 months, respectively. On the mucocele wall mucosa, which had been smooth during surgery, polyps and granulations developed after surgical drainage and lasted for a considerable time. Although endoscopic transnasal opening of mucocele is a method of choice, we recommend follow-up of such patients for long periods, at least until the frontal skull base dura returns to its original position.

Aged↗

PubMedDate not supplied

Unusual effects of histamine antagonists on canine nasal blood vessels.

This paper documents some of the lesser-known effects of antihistamines on nasal blood vessel smooth muscle. An in vitro muscle tension detecting technique was utilized. Three different H1 receptor antagonists (pyrilamine maleate, chlorpheniramine maleate, promethazine hydrochloride), and the H2 antagonist metiamide were used. Besides their basic antihistaminic effect, H1 antagonists (classical antihistamines) induced a contraction, enhanced norepinephrine- and epinephrine-induced contractions, and relaxed the sustained contraction induced by methoxamine hydrochloride or high concentrations of potassium. Although these effects were quite similar to those induced by histamine, the mechanism of each effect was apparently different. Metiamide did not produce these effects except for the relaxation of the sustained contraction. The actions of histamine antagonists seem to be much more complicated than expected.

Animals↗

PubMedDate not supplied

Analysis of treatment results of hypopharyngeal cancer.

Sixty-three patients with squamous cell carcinoma of the hypopharynx were treated at the University of Tokyo between 1985 and 1993. Twelve patients were treated with surgery alone, 16 with preoperative irradiation, 26 with postoperative irradiation, and nine with irradiation alone. A tumor dose of 50 Gy (25 fractions/5 weeks) was used in postoperative irradiation, 40-60 Gy in preoperative irradiation, and 70 Gy in irradiation alone. When "number of indications," including, for example, partial pharyngectomy, positive or close (< or = 5 mm) margin, and extracapsular extension, was used for multivariate analysis in patients who underwent surgery, it proved to be the only significant prognostic factor for gross survival. Six of seven patients with a positive surgical margin or close margin who received postoperative irradiation had local recurrence. A tumor dose of 50 Gy (25 fractions/5 weeks) in postoperative irradiation is not enough. It is difficult to cure by irradiation metastases to the parapharyngeal lymph nodes large enough to be detected with CT. It is necessary to irradiate parapharyngeal lymph nodes prophylactically, but 50 Gy in postoperative irradiation may not be enough from our results. The same may be true for metastases to the paratracheal nodes, which lie close to the lower poles of the thyroid gland or within the superior mediastinum and are difficult to access through surgery. In the patients who were operated on, N stage and the number of lymph node metastases were significant for gross survival. When "number of indications" was used for analysis, "number of indications" proved to be the most significant prognostic factor for gross survival.

Carcinoma, Squamous Cell↗