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Biomedical subjects

Y Harada

Publications and source records attributed to Y Harada.

At least 541 records · Page 30Linked to original sources
PubMed1989

Protection of OK-432, a Streptococcus pyogenes preparation, against lethal infection of mice with herpes simplex virus.

We have studied the protective effect of OK-432, a biological response modifier (BRM) of Streptococcus pyogenes origin, on the lethal infection of mice with herpes simplex virus (HSV)-1. A single intraperitoneal (i.p.) injection of more than 10 micrograms of OK-432, when given at least two days before the infection, gave a marked effect yielding nearly 100% protection against ordinarily lethal infection. The protection was independent of the amount of infected virus inoculated. When given after the infection, the agent even at the maximal dose (100 micrograms), produced only a marginal effect. A single i.p. administration of OK-432 augmented the natural killer (NK) activity of peritoneal exudate cells and spleen mononuclear cells in mice 2 to 3 days after injection of OK-432, coinciding with the times when it induced a survival effect on HSV-infection. Treating OK-432-treated mice with a combination of an anti-macrophage agent, silica, and an anti-NK cell agent, anti-asialo GM1 serum, before infection diminished the antiviral effect of OK-432. The OK-432 protection against HSV infection was also markedly diminished in athymic nude mice. Thus, the protective effect of OK-432 on lethal HSV infection seems to be based on the activation of NK cells, macrophages, and T lymphocytes.

Animals↗
PubMed1989

Properties of mouse melanoma antigen and its secretion mechanism from the cell surface.

We analyzed the biochemical properties and biological significance of the melanoma antigen secreted in the culture supernatants of B16 melanoma cells. The 80 kilodalton (kd) molecule bearing the epitopes of mouse melanoma antigen was found to associate noncovalently with an 18 kd moiety in the culture supernatants as well as on the cell surface. Tunicamycin treatment of B16 cells did not affect the expression of the 69 kd nonglycosylated form of the 80 kd molecule but did abolish the association between the two molecules on the cell surface. We could not detect this antigen as a soluble form when the N-linked glycosylation was inhibited. Therefore, the glycosylation of the 80 kd molecule is essential for the formation of the 80 kd/18 kd complex and also for the secretion. Moreover, the affinity-purified melanoma antigen from the supernatants could induce anti-melanoma suppressor cells which block the generation of cytotoxic T lymphocytes against melanoma cells. Thus, the 80 kd glycoprotein as a soluble melanoma antigen performed a pivotal function in the escape mechanisms of melanoma cells from the host immune surveillance system.

Animals↗
PubMed1989

Density of GM3 with normal primary structure determines mouse melanoma antigenicity; a new concept of tumor antigen.

We attempted to induce anti-melanoma cytotoxic T cells (CTL) and suppressor T cells (Ts) inhibiting CTL generation by using liposomes carrying various densities of GM3 as tumor antigens. We found that liposomes carrying 6-16 mol% of GM3 with normal primary structure successfully generated anti-melanoma CTL and suppressor T cells, while liposomes with GM3 outside this range had little or no such activity. Anti-melanoma CTL induced by GM3(NeuGc)-liposomes belonged to CD4-/CD8- double-negative CD3+ CTL while GM3(NeuAc)-liposomes induced two types of T cells, CD4+ T cells and double-negative I-J positive T cells which mediated inhibition of the induction of anti-melanoma CTL responses. These cell types were the same as those induced by mitomycin C-treated melanoma cells for CTL induction and soluble melanoma antigen for Ts generation. The results clearly demonstrate that even GM3 with normal primary structure can, at a certain density, generate melanoma antigenicity.

Animals↗
PubMed1989

Morphological evidence of the formation of intracellular collagen fibrils in the embryonic mouse molar odontoblasts induced by colchicine administration.

The effects of colchicine on collagen formation were examined ultrastructurally using secretory odontoblasts in mouse molar tooth germs isografted to the spleen for 1 week. Colchicine in concentrations of 0.025 or 0.05 mg/0.1 ml was injected intravenously 12-24 h prior to harvesting. Colchicine induced the disruption of the Golgi apparatus and caused the accumulation of various types of Golgi-associated vacuoles containing collagenous fibrillar structures. Many vacuoles containing fine particles, nonstriated parallel filaments, banding patterns with a periodicity of approximately 63-nm intervals, and occasionally segment-long-spacing-like assemblies were aggregated in the cytoplasm during the experimental period. These morphological changes in vacuole contents may reflect the initial steps for polymerization of the intracellular collagen fibrils. The majority of the aggregated vacuoles were degraded by fusion with lysosomes but banded filamentous material in some vacuoles appeared to polymerize into the collagen fibrils with native structures. These results suggested that in unsecreted vacuoles accumulated in the odontoblasts as a result of colchicine administration the polymerization of collagen fibrils with native structures can occur.

Animals↗
PubMed1989

Modulation of plasma exudation by PGE2 and that of leukocyte migration by LTB4 in inflammatory models.

Des-Phe8-Arg9-BK could be detected in the entire course of rat carrageenin pleurisy up to 24 h, together with a reduction of the residual levels of high molecular weight kininogen and prekallikrein. On the basis of this continuous release of bradikinin, prostaglandin E2 was released up to 5 h in the pleural exudate and enhanced the plasma leakage. In rat cardiac infarction, the initial increase in the number of polymorphonuclear leukocytes in the cardiac tissue was accompanied by leukotriene B4 in the tissue and this was followed by the second increase and activation of the complement system.

Animals↗
PubMed1989

Synthesis of glycocalyx and associated structures in vestibular sensory cells.

The ultrastructure of the glycocalyx with special reference to the synthesizing process was studied in the guinea pig vestibular sensory cells using the tannic acid staining technique. The glycocalyx emerged from the outer layer of the plasma membrane covering the entire length of the cilia. This glycocalyx also interconnected the ciliary structures tightly, such that a structural continuity was established between actin-membrane links and the glycocalyx. Interconnections between the actin filaments themselves were also noticed in the stereocilia as well as interconnections between individual actin filaments and the plasma membrane. These findings indicate that the glycocalyx and the ciliary interconnections may be closely related to the sensory hair transduction system. In the cellular cytoplasm, vesicles seemingly related to the synthesis of the glycocalyx were observed. These coated vesicles, which were synthesized by the Golgi complex and endoplasmic reticulum, interacted with the plasma membrane forming a coated pit. The lysosomal-like bodies also observed in the cell were closely related to the glycocalyx as well. Thus the glycocalyx seems to be synthesized by the endoplasmic reticulum and Golgi complexes and transferred through the coated vesicles or lysosomal-like bodies to the apical plasma membrane.

Animals↗
PubMed1989

[Effect of external decompression on the development of delayed ischemic neurological deficits after subarachnoid hemorrhage].

The protective effect of a large decompressive craniectomy against delayed ischemic neurological deficits (DIND) was evaluated in patients operated on after subarachnoid hemorrhage due to a ruptured aneurysm. In 54 cases, a large decompressive craniectomy was performed (Group D), and 41 patients underwent conventional craniotomy (Group ND). Transient DIND appeared in three (17%) of the 18 Group D patients of Hunt and Kosnik grade I or II, but permanent deficits were not observed in this group. In Group ND, permanent DIND developed in seven (21%) of the 33 grade I or II patients, despite their having received the same medical care. This difference was statistically significant. However, there were no differences in outcome among patients of grades III, IV, and V. These results suggest that, at least in patients of grade I or II, a large decompressive craniectomy, performed early, will prevent DIND after subarachnoid hemorrhage. The procedure may prevent the increase in intracranial pressure and decrease in perfusion pressure brought on by vasospasm and the development of brain edema.

Adult↗
PubMed1989

[Polyclonal B cell activation induced by Actinomyces viscosus T14V. Responsiveness of human peripheral blood B cells].

We have previously reported that the sonicate extrast from Actinomyces viscosus T 14 V (Av. sup) causes polyclonal B cell activation (PBA) in murine splenic B cells without any T cell assistance. However, there are some reports describing T cell dependency of PBA induced by A. viscosus in human peripheral blood B cells, and it is still controversial whether or not A. viscosus has the capability of exhibiting PBA without the help of T cells. In this report, we examined PBA in human peripheral blood B cells using the same Av. sup which induced T cell independent PBA in murine splenic B cells. The PBA was evaluated in terms of immunoglobulin (Ig) production by means of micro-ELISA method and cell proliferation by incorporation of 3H-TdR after incubation of cells for 5 or 7 days with Av. sup. Human peripheral blood B cells were highly purified by the following methods; The peripheral blood was collected by venipuncture and the peripheral blood mononuclear cells were harvested using gradient centrifugations. These cells were passed through a Sephadex G-10 column, and T cells were eliminated by rosette formation with sheep red blood cells. B cells were highly purified from these T cell-depleted cell populations by panning method with anti-human Ig antibody coated dishes followed by complement-dependent cytotoxisity using monoclonal antibody cocktails consisting of OKT 3, OKT 4 and OKT 8. These highly purified B cells could not respond to T cell mitogens such as PHA.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomycetales↗
PubMed1989

[Frequency of three-rooted mandibular first molars. Survey by x-ray photographs].

The frequency of three rooted mandibular first molars was surveyed. Subjects were of 1,353 male and female students trained in radiology at Fukuoka Dental College whose average age was 24.3 years old. Dental (complete radiographic survey using 14 films) and panoramic radiographs of their mandibular first molars were taken during a period of 9 years from 1978 to 1986. The results were as follows: 1) The number of the three-rooted mandibular first molars was 440 (18.8%) of 2,331 teeth, including 240 (20.6%) of 1,163 in the right side and 200 (17.1%) of 1,168 in the left. 2) 274 (11.8%) of the three-rooted mandibular first molars were identified by radiographs of the premolar region, 42 (1.8%) by radiographs of the molar region, 124 (5.3%) by radiographs of both the premolar and the molar region. 3) Panoramic radiography identified 70 (15.9%) out of 440 three-rooted mandibular first molars. 4) 136 (12.7%) of 1,070 subjects who had bilateral mandibular first molars had three-roots on both sides 127 (11.9%) of 1,070 had them on one side.

Adult↗
PubMed1989

[Variations of dentition in raccoon dogs (Nyctereutes Procynoides Viverrinus T.) Anomalies in number of the teeth].

A study on the number of anomalous teeth was made by using gross and radiographic examinations on 179 skulls (male: 68, female: 53, unknown: 58) of raccoon dogs (Nyctereutes Procynoides Viverrinus T.) captured in the northern part of Kyushu. Results were as follows: 1. 8 skulls had 15 supernumerary teeth. They were in the upper incisor, the upper third premolar and the upper and lower first premolar regions. 2. 35 skulls had 58 congenitally missing teeth. Most of them were upper and lower first premolars or lower third molars. 3. One skull had one supernumerary tooth in the upper second incisor region and one congenitally missing tooth, a lower third molar. 4. The anomalous teeth were about 25%, the supernumerary teeth and congenitally missing teeth were about 4.5% and 20% respectively.

Animals↗
PubMed1989

Morphological study of the cells in the planum semilunatum.

The fine structures of the epithelial cells in the planum semilunatum were investigated using scanning and transmission electron microscopy. The chicks and guinea pigs were used for this study. In both guinea pig and chick, the body of the planum semilunatum cell was cylindrical. Its length decreased towards the utricular and canal side, resulting in cuboid-shaped cells. In the guinea pig, the flat surfaced hexagonal cells with few microvilli were arranged like flagstones over the whole area of the planum semilunatum, while in the chick the cells with many prominent microvilli were found on both sides of the crista. The cytoplasm contained well developed endoplasmic reticula and abundant granules. Interdigitations between the neighbouring cells were well developed. Basement membrane was slightly folded but no basal infolding was observed. The morphological characteristics of the planum semilunatum cell highly suggest that these cells have some secreting function.

Animals↗
PubMed1989

Structural and physiological change of the bullfrog semicircular canal due to gentamicin intoxication.

The effect of Gentamicin (GM) on the vestibular organ was studied using bullfrogs. The ototoxicity was compared among 3 different ways of administration, i.e., intraperitoneal (IP), intramuscular (IM) and intralabyrinthine (IL) injections. Morphological change of the posterior canal crista was observed by SEM. The posterior canal ampullary nerve action potentials (AP) were recorded, and were compared with SEM findings of the sensory epithelia. Morphological and physiological changes were severe in the order of IL greater than IM greater than IP. Morphological and physiological changes developed as the postinjection time elapsed. Morphological damage started at the narrow portion of the crista and developed towards the center and finally towards the periphery. Physiological change was already observed before the morphological damage. Physiological change tended to correlate with the morphological damage.

Action Potentials↗
PubMed1989

Changes in levels of mucosal glycoprotein on cysteamine-induced duodenal ulcers in rats.

Duodenal ulcers were induced in rats by cysteamine administration. Time-course changes in duodenal hexosamine, blood flow and intragastric pH were measured, as well as changes in the susceptibility of Brunner's glands to concanavalin A (Con A) staining. Hexosamine contents in the duodenum decreased significantly at 5 and 24 h. In the control group, Brunner's glands were stained brown using Con A staining. One day after cysteamine administration, the extent of Con A staining markedly decreased. At 3 and 7 days, gland susceptibility to staining was essentially the same as that of the control group.

Animals↗
PubMed1989

[A case of retroperitoneal bulky tumor with cryptorchidism].

A 37-year-old male was presented with an upper abdominal mass. A retroperitoneal bulky tumor was detected and operative biopsy revealed seminoma. The right testis was undescended and atrophic which was located at the left inguinal lesion. Pathologically, the primary tumor cells were not found in the left orchiectomied testis, but only scar and fibrosis were compatible with a burned-out testicular tumor. This patient showed partial regression by multidisciplinary therapy including combined chemotherapy with CDDP, etoposide and peplomycin, and is still on the same condition and alive for 3 years. In case of extragonadal germ cell tumor without apparent testicular involvement, it is a problem to differentiate primary extragonadal germ cell tumor from occult and burned-out testicular tumor. Testis should be examined by all means available including careful exploration.

Adult↗
PubMed1989

Feasibility of non-invasive measurement of the left ventricular max (dp/dt) by continuous recording of the ascending aortic diameter change: principle and experimental study.

If a method produces a pressure contour with an arbitrary relative amplitude and without a base line, i.e. a pressure tracing without scale, and another method gives two out of the following three values: peak; bottom; and mean pressures, then we can obtain a pressure contour with a specified pressure scale. We can also obtain the value of the derivative of pressure with respect to time. If the curve of the ascending aortic diameter change closely resembles the pressure contour at the same portion (assumption 1), we can obtain the aortic pressure contour with an arbitrary pressure scale measuring the aortic diameter by a non-invasive ultrasonic method. The aortic peak systolic, end-diastolic and mean pressures can be measured by other non-invasive methods. Therefore, we can specify the pressure scale of the contour, and obtain the maximum derivative of the aortic pressure. If the maximum derivative of the left ventricular pressure (max dp/dt) can be substituted by that of the aortic pressure (assumption 2), we can obtain the former (max dp/dt) by non-invasive measurements only. We confirmed assumptions 1 and 2 by animal experiments, and showed the feasibility of non-invasive measurements of the left ventricular max (dp/dt) by interpreting the aortic diameter change curve as the pressure contour.

Animals↗
PubMed1989

[The effect of chemical sympathectomy on the cell kinetics of gastric mucosa in golden hamsters].

The effects of chemical sympathectomy on the differentiation of the generative cells, superficial epithelial cells and gastrin cells of the gastric mucosa of hamster were examined by 3H-thymidine autoradiography. The labeling indices of the generative cell zone in the gastric mucosa and antral gastrin cells showed a transient significant decrease after chemical sympathectomy, and then they were gradually restore with time. After 4 weeks onward, the labeling indices of the generative cells showed a slightly low value compared with those in controls. The renewal of superficial epithelial cells and gastrin cells was examined in the hamster sympathectomized for 4 weeks. The time required for the differentiation to PAS positive superficial epithelial cells or gastrin cells had a tendency to elogate after chemical sympathectomy. These results suggest that chemical sympathectomy played an inhibitive action on the proliferation and the differentiation of gastric mucosa.

Animals↗
PubMed1989

[Flowcytometric analysis of lymphocytes proliferated in vitro by PPD].

The present study was undertaken to do phenotype determination of in vitro proliferating lymphocytes by PPD stimulation using combination of monoclonal antibodies and flow-cytometry. The results obtained were as follows: 1) PPD induced a significant proliferation of activated T cell subsets (Leu4+DR+ cells, IL2-R+Leu3+ cells). 2) PPD also induced a significant increase in Pan T cells (Leu4+) and helper T cells (Leu3+8-). Taken together, these results indicated that PPD induced proliferating lymphocytes belong predominantly to helper T cell subset. 3) The numbers of inducer T cells (Leu3+8+), suppressor T cells (Leu2+15+) and cytotoxic T cells (Leu2+15-) were not influenced by PPD-stimulation. 4) However, PPD induced a smaller, but significant proliferation of IL2-R+Leu2+ cells. 5) The number of B cells (Leu4-DR+) tended to increase slightly after PPD-stimulation.

Adult↗