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Biomedical subjects

N Yamagata

Publications and source records attributed to N Yamagata.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Lung injury associated with bucillamine therapy].

We have reported previously a first case of interstitial pneumonitis in rheumatoid arthritis treated with bucillamine in 1989. Thereafter, a dozen cases with lung injury associated with bucillamine therapy have been reported. To explore the similarities among these patients, we tried to carry out a survey concerning the lung injuries in these cases in the present study. We obtained the following results. (1) Patients with lung injury consisted of 7 females and 3 males, aged 65 years on average (59-72). (2) The total amount of bucillamine used was 20-40 g on average (5.1-144 g) during approximately 100 days. (3) Serum rheumatoid factor was positive in 9 of 10 cases. (4) HLA-DR4 was significantly (p less than 0.01) detected in all cases of lung injury associated with bucillamine. (5) Interestingly the effect of bucillamine on rheumatoid disease activity was excellent in most cases. (6) Drug lymphocyte stimulation test (DLST) using bucillamine was performed in 6 cases. Positive DLST was found in 3 of 6 cases. These results suggest that cell-mediated hypersensitivity reaction (Coombs & Gell type IV) may contribute to the development of lung injury associated with bucillamine therapy.

Aged↗
PubMed1991

Direct visualization of colloidal gold-bound molecules and a cell-surface receptor by ultrahigh-resolution scanning electron microscopy.

The structure of protein A-coated colloidal gold particles, and of macrophage cell-surface receptors conjugated with immunogold particles, was studied using an ultrahigh-resolution scanning electron microscope. Protein A, when conjugated with 15-nm gold, formed a coat completely surrounding the particle. Particles conjugated with both protein A and immunoglobulin G (IgG) were similar, but with additional protrusions formed by the IgG. IgG molecules directly bound to gold were resolved sometimes as complexes of three units, sometimes as more filamentous, V-shaped structures. On the cell surface of macrophage reacted with a monoclonal antibody to Mac-1 antigen (the murine C3bi receptor) followed by protein A-gold, gold particles were seen to be linked via the IgG to the receptor, visualized as a round granule.

Animals↗
PubMed1991

Lysosomal enzyme activities in experimental granulomatous inflammation.

Foreign-body (dextran beads) and hypersensitivity (antigen-coupled agarose beads) lung granulomas were induced in BALB/c mice by the intratracheal injection of beads. Large granulomas developed, which reached peak intensity within 3 days and declined in size thereafter. Aqueous extracts of both granulomas contained high levels of lysosomal enzymes N-acetyl-beta-D-glucosaminidase (NAG) and lysozyme. Lysosomal enzyme activities in the extracts correlated with granuloma sizes. Dispersed granuloma cells were able to produce these enzymes. These results suggest that lysosomal enzymes may reflect the activity/size of granulomatous inflammation.

Acetylglucosaminidase↗
PubMed1990

Involvement of interleukin-1-like factor(s) in type II collagen-induced arthritis in mice.

To explore the role of interleukins in development of arthritis, we induced collagen-induced arthritis in mice and examined interleukin activities in the inflamed joints. Arthritis developed in 90% of mice 4-5 weeks after primary immunization with type II collagen. Joint extracts from mice with collagen-induced arthritis contained high levels of interleukin 1 (IL-1)-like activity but not interleukin 2 (IL-2) or interleukin 4 (IL-4) activity. IL-1-like activities in the lesions were correlated with development of arthritis assessed by joint swelling and erythema. These results suggest that IL-1-like factor(s) may participate in the etiopathogenesis of collagen-induced arthritis in mice.

Animals↗
PubMed1990

Antibodies to interleukin 2 in sera of autoimmune-prone mice.

Autoimmune-prone mice spontaneously develop the disease characterized by autoantibodies to a wide variety of antigens. In the present study, we have demonstrated that IgG antibodies to interleukin 2 (IL-2) are to be found in serum of autoimmune mice in association with ageing. These antibodies can neutralize the biological activity of IL-2 and thus play an important role in the etiopathogenesis of autoimmune disease.

Aging↗
PubMed1990

[Cytotoxic effects of restorative materials on early passage cultured cells derived from human gingiva (in vitro)].

This study evaluated the cytotoxic effects of three common restorative materials on early passage cultured cells derived from human gingiva (HG cells). Other early passage cultured cells derived from human dental pulp tissues (HP cells) and L cells established obtained from mouse subcutaneous tissues, were also examined. Cytotoxicity was assessed according to the uptake of neutral red and dye exclusion with nigrosin. The cytotoxicity was in the order of glass ionomer cement (highest), light cured composite resin and dental amalgam. HG cells were the least sensitive to the materials tested. Both filtration of extracts and addition of serum into the extract affected the cytotoxicity. Glass ionomer cement increased the acidity of the extract, but the two other materials did not. Dissolution of metal ions, aluminium, tin, copper, mercury and zinc occurred from the materials. The extract of the composite resin had a different absorbance. This study disclosed differences in the cellular reaction to the restorative materials. Thus, utilization of early passage cultured cells is necessary for biological evaluation of the dental materials in vitro.

Animals↗
PubMed1988

Multiple cytokine activities and loss of interleukin 2 inhibitor in synovial fluids of patients with rheumatoid arthritis.

Attempts to detect immune mediators in rheumatoid arthritis synovial fluids (RA-SF) by bioassays have yielded conflicting results, and so we analyzed the immune reactions occurring within rheumatoid joints using monospecific immunoassays for cytokines such as interleukin 1 beta (IL-1 beta), interleukin 2 (IL-2) and gamma interferon (gamma-IFN). Furthermore, we examined the IL-2 inhibitors to clarify the immunoregulatory mechanism in the lesion. SF from active RA contained a significant amount of IL-1 beta and IL-2 but not gamma-IFN. In contrast IL-2 inhibitor activity was depressed in RA-SF regardless of clinical disease activity. Our results suggest that cytokine overproduction and deficiency of inhibitory signals may result in the overactivity of cytokines and the overactivity may participate in the joint lesions of RA.

Antibodies, Monoclonal↗
PubMed1987

[Multiple submucosal cysts of the stomach associated with IIc + III type early gastric cancer--report of a case].

A 59-year-old man was admitted with a complaint of epigastric discomfort, under the diagnosis of gastric cancer, subtotal gastrectomy was performed. In the resected specimen IIc + III type early gastric cancer were observed at the lesser curvature of the corpus and multiple submucosal cysts in almost entire area of the stomach. Histologic examination confirmed early adenocarcinoma and an atypical epithelium, which was present separately. Submucosal cysts consisted of a pseudo-pyloric-gland-type of epithelium, containing some fundic glandular and foveolar epithelium. Frequent erosion and regenerated epithelium and extensive intestinal metaplasia were observed in the gastric mucosa. There was no carcinomatous change in the submucosal cysts.

Adenocarcinoma↗
PubMed1986

[Adenoid cystic carcinoma of the esophagus].

A 56-year-old man was admitted with the complaint of dysphagia. X-ray studies and endoscopy revealed a protruding tumor at the middle third of esophagus. Under the diagnosis of esophageal cancer, subtotal esophagectomy was performed. A Borrmann type I like tumor measuring 6.7 X 3.8 X 2.2 cm was identified on the resected specimen. The surface of the tumor was irregular, nodular and covered with thin compressed esophageal mucosa. The histology of the tumor was consistent with adenoid cystic carcinoma. Incidentally, small foci of invasive squamous cell carcinoma were found adjacent to this tumor. There was no lymph node or remote organ metastasis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

[Leiomyosarcoma of the remnant stomach--a case report].

A case of leiomyosarcoma of the remnant stomach is reported. The patient was a 57-year-old woman whose chief complaint was easy fatigability. Twenty six years earlier, she had undergone gastrectomy with the diagnosis of duodenal ulcer. By X-ray examination of the stomach, a Borrmann type I gastric cancer was suspected on admission. Endoscopic study of the stomach was performed, and a diagnosis of leiomyosarcoma was made from the biopsy specimens. Total gastrectomy was performed. On the resected specimen, a Borrmann type I like tumor measuring 4.5 X 5.5 X 3.2 cm was identified in the anterior part of the body of the remnant stomach. Histologically, the lesion was confirmed as leiomyosarcoma of the stomach.

Duodenal Ulcer↗
PubMed1984

[Primary adenosquamous carcinoma of the stomach--a case report].

A 56-year-old man was hospitalized with the complaint of upper abdominal discomfort. A gastrointestinal series revealed a filling defect in the body of the stomach. Under the diagnosis of gastric cancer, total gastrectomy was performed. Borrmann III type cancer measuring 5 X 4 cm, extending to the antrum and the upper portion of the body of the stomach, was identified in the body. Histologically, most of the tumor consisted of squamous cell carcinoma. Adenocarcinoma and a small nest of squamous metaplasia were observed at the peripheral wall of this tumor. The pathological diagnosis was adenosquamous carcinoma. In some regional lymph nodes, metastasis of adenocarcinoma was observed.

Adenocarcinoma↗
PubMed1983

Changes in simple and complex behaviors following kindled seizures in rats: opioid and nonopioid medication.

To learn more about postictal behaviors and their underlying mechanisms, five behaviors and EEG recordings were studied following fully generalized, kindled seizures in rats. The behaviors included bar pressing for food; tail withdrawal, squeak, and multiple squeak responses to painful tail shocks; consumption of freely available food; clinging to a vertical grid; and locomotion. Latencies from the end of a seizure afterdischarge until each behavior recovered were compared and were found to cluster in three distinct pairs. Locomotion and grid clinging recovered most quickly; consumption of freely available food and EEG postictal depression recovered next; and bar pressing for food and the multiple squeak response recovered most slowly. Naloxone pretreatment (10 mg/kg but not 1 mg/kg) shortened recovery to multiple squeak responses, grid clinging, and locomotion, without affecting recovery of bar pressing, food consumption, or EEG postictal depression. These results suggest that complex behaviors recover more slowly following a seizure than simple behaviors. It also appears that opioids are released by a kindled seizure and mediate certain postictal changes in motor- and pain-related behaviors.

Animals↗
PubMed1981

Metal content of shark muscle powder biological reference material.

Powdered dried shark muscle (Cephaloscyllium umbratile) is a promising biological reference material for metal analysis. Homogeneity indices (CV%) for Na, K, Zn, As, Ca, and Hg of the shark powder were within 5%. Mercury and arsenic concentrations (total Hg, 9.1 ppm dry wt, As, 99 ppm dry wt) in shark powder are relatively high. Muscle can be obtained inexpensively, and the powder can be preserved indefinitely if kept cold.

Animals↗
PubMed1979

Industrial emission of cadmium in Japan.

Direct emission of cadmium into air and water in Japan has been controlled on the basis of the Emission and Effluent Standards. Environmental quality in these media has been improved, but delayed effects of these emissions in the past are now manifest by contamination of agricultural acreage in various parts of this country. Special land improvement projects are therefore required, and cost allocation should be made on the basis of scientific assessment of natural background. An impact assessment on accidental release of potential sources of cadmium dispersed in the water system should be made on the basis of inventory surveillance. Assessment of natural background can practically be made by two means. One is to examine the vertical distribution of cadmium in a soil profile and to search for a subsurface layer in which there can be no contamination. Another is the use of the Zn/Cd ratio as an index of pollution, a value of 400 being suggested as a screening level. The transport of cadmium was found to occur principally in particulate form, and sampling and analysis of water together with suspended solid after a heavy rainfall is suggested as a useful means for assessing the character of a catchment area and for planning the improvement of land surface in mining districts.

Agriculture↗