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Biomedical subjects

M Nasu

Publications and source records attributed to M Nasu.

At least 379 records · Page 21Linked to original sources
PubMed1983

Ameloblastoma. Light and electron microscopic study.

Light and electron microscopic studies of ameloblastoma were reviewed. The 21 cases of ameloblastoma examined were classified into 12 cases of the plexiform type and nine of the follicular type. The average age of the patients with the plexiform type was 25.3 years, while that of those with the follicular type was 54.4 years. Histologically, in the follicular type, the tumor cells consisted of two cell types, central polyhedral and star-shaped cells resembling the stellate reticulum and peripheral cuboidal and columnar cells similar to the inner enamel epithelium. The resemblance between the tumor follicle and enamel organ was confirmed electron microscopically. In the plexiform type, however the tumor cells did not show two cell types, but resembled squamous epithelium. Electron microscopically, all cells of the tumor strands had relatively numerous bundles of tonofilaments and were joined together by desmosomes. Differentiation of tumor cells to squamous epithelium less evident than in normal surface epithelium. We speculate that these histological differences between plexiform and follicular types represent the differentiation tendency of the remnant of the dental lamina at the time of neoplastic transformation. What decides the histological pattern is unknown but age may be a factor. Central epidermization with keratinization or microcytic changes was frequently seen in the follicular type. Keratinization and microcystic changes rarely occurred in the plexiform type. We do not believe that these changes are a form of involution or result from multipotentiality of the tumor cells.

Adolescent↗
PubMed1982

An epidemiological study of Serratia marcescens infections by bacteriocin typing.

Bacteriocin sensitivity typing according to the method of Traub (Appl. Microbiol. 1971. 21: 837-840) was carried out on 226 clinical isolates of Serratia marcescens obtained from inpatients at Nagasaki University Hospital during the period from January 1976 to December 1978. The isolates were divided into 16 different bacteriocin types, mainly 26, 4, and 9. The distribution of the types suggests that Serratia marcescens infections may be caused by cross infection. Reproducibility of bacteriocin typing and the relationship between serotypes (O-antigen) and bacteriocin types are discussed in regard to the application of this method to the study of nosocomial infections.

Bacterial Infections↗
PubMed1982

Amyloid deposits in the aged tongue: a postmortem study of 107 individuals over 60 years of age.

The incidence and distribution of amyloid deposits in aged tongues obtained from 107 necropsies over 60 years of age were examined. Thirty-nine tongues were affected with amyloid deposits and the overall incidence was 36.4%. The incidence increased with each advancing decade, and the group over 90 years old showed the highest incidence of 59.6%. Although the amount of amyloid deposits differed in each case, severely affected cases were most frequently found in the advanced decades. Amyloid deposits were almost always confined to blood vessels, especially arterioles and arteries. They occasionally occupied the entire wall and occluded the lumen. Blood vessels affected with amyloid were usually located in the muscle layers of the tongue. Vessels in the subepithelial layer and lingual glands were, however, sometimes affected. Amyloid deposits were resistant to Congo red staining with the potassium permangante method, and stained positively with DMAB. The present study suggested that the tongue is an important organ as to the appearance of amyloid deposits in elderly persons.

Age Factors↗
PubMed1982

Histological observation of the submandibular gland with special reference to the focal lymphocytic infiltration.

Focal lymphocytic infiltration of the submandibular gland was investigated on the autopsy cases. The materials examined were 340 cases without the collagen diseases and 28 cases with collagen diseases. Of the 28 cases with collagen diseases, 20 were systemic lupus erythematosus, 2 with the coexistence of systemic, lupus erythematosus and Sjögren's syndrome, 4 with rheumatoid arthritis and 2 with progressive systemic sclerosis. Among the cases without the collagen diseases, the focal lymphocytic infiltration was seen in 154 cases (74%) of 209 males and in 94 cases (71%) of 131 females. All 28 cases with collagen diseases had a focal lymphocytic infiltration. The incidence of grade 3 or severe infiltration was 4% in the males and 14% in the females in the cases without the collagen diseases, 65% in the 20 cases with systemic lupus erythematosus, 50% in the 4 cases with rheumatoid arthritis and 50% in the 2 cases with progressive systemic sclerosis. No cases of very severe infiltration were found, which were seen in the classical Sjögren's syndrome, in both cases with and without the collagen diseases. Hyperplastic change in the ductal cells, which can be called an epimyoepithelial island, was found in 23% of the cases with collagen diseases. These observations suggest that the focal lymphocytic infiltrations is a focal sign of the immunologic disorder of the submandibular gland in the collagen disease.

Adolescent↗
PubMed1982

[Compared studies of antimicrobial agents against E. coli, Klebsiella, Citrobacter and Proteus isolated from urinary tract infections].

In vitro activities of antibacterial agents against E. coli, Klebsiella, Citrobacter and Proteus which were isolated from patients urinary tract infections at 8 hospitals in Japan, were investigated by agar dilution method from July to October in 1979. The summarized results are as follows. 1. Among oral antibacterial agents, MPC and PPA have showed potent antibacterial activities against E. coli and Klebsiella. Among parenteral antibiotics, CTM was the most active against E. coli and Klebsiella. However, ABPC-resistant E. coli and Klebsiella have appeared to occupy about 40% and 96% of bacteria isolated from urinary tract infections, respectively. 2. In vitro activities of antibacterial agents against Proteus and Citrobacter showed not so potent. 3. Causative organisms in female patients with simple urinary tract infections were mainly E. coli and Klebsiella. 4. Among oral antibacterial agents, PPA have shown similar antimicrobial activities against E. coli isolated from simple and complicated urinary tract infections. ABPC and MPC have been influenced in some degree by these factors. However, parenteral antibiotics are not influenced by these factors. On the other hand, in vitro activities of antibacterial agents against Klebsiella isolated from simple and complicated urinary tract infections were similar.

Adult↗