Biomedical subjects
Publications and source records attributed to T Hamada.
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BACKGROUND: The adherence of Candida species to denture acrylic is the initial event leading to Candida-associated denture stomatitis, with Candida albicans being the main aetiological agent. However, the increased incidence of immunocompromised patients in the community has resulted in the emergence of a number of non-albicans Candida species as causative agents of this disease, which is commonly managed by topically delivered polyene antifungals. Hence, we investigated the effect of the exposure of denture acrylic surfaces to nystatin and amphotericin B on the subsequent adhesion of six different Candida species. METHODS: Acrylic strips were exposed to subtherapeutic concentrations of the two polyenes for 30 min, and the adhesion of 4 isolates each of C. albicans, Candida glabrata, Candida guilliermondii, Candida krusei, Candida parapsilosis and Candida tropicalis was assessed using a previously described in vitro method with slight modifications. RESULTS: Overall, the results indicated a 35.9% (p < 0.01) and 63.1% (p < 0. 01) reduction, respectively, in yeast adhesion to denture acrylic following exposure to nystatin and amphotericin B, although this effect was not uniform for all the tested isolates. Thus, all C. glabrata, 3 C. guilliermondii and a single isolate each of C. krusei, C. parapsilosis and C. tropicalis were not significantly affected by nystatin exposure, and a single isolate each of C. glabrata and C. guilliermondii were not significantly affected by amphotericin B. CONCLUSIONS: The present data, the first on the effect of polyenes on a wide range of Candida species, indicate that the in vitro exposure of denture acrylic to subtherapeutic concentrations of nystatin and amphotericin B suppresses the adherence of pathogenic Candida species in general.
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A 45-year-old woman presented with persistent headache which was of acute onset and occurred daily. Laboratory findings included thrombocytosis, elevated levels of antinuclear antibody, rheumatoid factor, and antibodies to Epstein-Barr virus (EBV). Magnetic resonance image of the head, left selective external carotid angiography, temporal arterial biopsy, and cerebrospinal fluid revealed no abnormal findings that could explain her headache. Her headache was compatible with NDPH, which has been reported by Vanast, and was thought to be related to EBV reactivation.
PURPOSE: This review summarizes the methods employed to evaluate denture cleansers and makes some suggestions on the methodology of evaluation. MATERIALS AND METHODS: More than 20 articles evaluating the efficacy of denture cleansers were compared, and the advantages and disadvantages of each method were evaluated. RESULTS: The results obtained vary depending on the methods used to evaluate the efficacy of denture cleansers, particularly among in vitro and in vivo assays. In addition, it is pointed out that chemical denture cleansers are not as efficacious in clinical use as in the in vitro assay. The uncertainty over efficacy may be caused by nonstandardized methodology and reports of conflicting results. CONCLUSION: A standardization of the methodology is needed. This should include evaluation of the efficacy of cleansers through both in vivo and in vitro assay methods; standardization of the materials and methods used in studying the efficacy of denture-cleansing regimens; and the examination of not only selected microorganisms from limited surface areas of a denture, but the microorganisms in denture plaque from the whole surface of a denture. It would also be preferable to use methods and/or media that make it possible to not only qualify but also quantify the microbial plaque.
PURPOSE: Although denture adhesives are widely used by the elderly, it is unknown whether denture adhesives support microbial growth. Therefore, we investigated the growth of Candida species on six commercial denture adhesives. MATERIALS AND METHODS: The growth of a single isolate of C albicans and C tropicalis on six commercial denture adhesives was investigated by monitoring pH changes in growth media. RESULTS: In the preliminary study, the effect of each product on the pH value of the medium was examined; a single product itself significantly reduced the pH of medium below 5.0. When the yeast was grown on the materials, the pH changes in the media varied depending on the adhesive materials and, to a greater or lesser extent, on whether they showed antifungal activity. Two products (Cushion Collect and Collect Soft A) significantly suppressed C albicans growth (P < 0.01), and one product (Collect Soft A) effectively reduced C tropicalis growth (P < 0.01). CONCLUSION: Our results suggest that denture adhesives possess antifungal activity to a greater or lesser degree. However, one product caused the reduction of pH below 5.0. Thus, in the daily use of denture adhesives, attention should be paid to both the materials and their microbiologic properties.
RNA interference (RNAi) may be induced by a plasmid with an inverted repeat (IR) sequence directing transcription of hairpin-type double-stranded RNA (dsRNA). This study examines the effects of changing various parameters of IR constructs on Drosophila and mammalian RNAi, using the dual luciferase system, RNAi activity was found to vary depending on IR length ass well as the length and sequence of the internal loop separating sense and antisense sequences. Both transient and stable RNAi occurred in Drosophila cultured cells. Although transient DNA-mediated RNAi was noted in most mammalian cells, no mammalian cells stably possessing IR sequences and hence RNAi activity could be obtained. In Drosophila, DNA-mediated RNAi was considerably weaker than long-dsRNA-mediated RNAi. The cytological data indicated that this was most probably caused by abortive processing of hairpin RNA produced within cells. DNA-mediated RNAi was examined at the level of Drosophila individuals using extramacrochaetae as a model gene, and the presence of an intron sequence in the single-stranded loop region was shown to be essential for effective RNAi.
Lipoid proteinosis (hyalinosis cutis et mucosae) is a rare, autosomal recessive disease. The main clinicopathological features comprise skin and mucous membrane infiltration and scarring with deposition of hyaline material. In this report, we describe a 6-year-old boy in whom a diagnosis of lipoid proteinosis was first suspected when he presented with blisters and erosions at 4 years, a history of life-long dysphonia and a previous epileptic convulsion. The diagnosis was confirmed by histology and identification of a homozygous frameshift mutation, 501insC, in exon 6 of the gene encoding extracellular matrix protein 1, ECM1. Lipoid proteinosis may show protean clinical features and be difficult to diagnose on clinical grounds alone. This case report illustrates that lipoid proteinosis may show protean clinical features and yet remain undiagnosed for many years. Although the gold standard for definite diagnosis remains histology, molecular characterisation of the gene mutation will add to our understanding of genotype-phenotype correlation and perhaps to the development of a rationale for future therapeutics.
To produce a new hybrid artificial liver system, cultured pig hepatocytes were used in this study. Hepatocytes from normal healthy pigs were cultured in multiwell dishes. From the third day of cultivation, hepatocytes were divided into three groups according to the media used (Group 1, L-15; Group 2, normal human plasma; Group 3, plasma from hepatic failure [HF] patients). Measurements of cellular function of the cultured pig hepatocytes included metabolic activity (gluconeogenesis and ureogenesis), DNA content, and amino acid changes in the plasma. The ability to provide gluconeogenesis and ureogenesis by the cultured hepatocytes in HF plasma was maintained for 3 days, equal to that observed in Groups 1 and 2. DNA content was no different in the three groups. Elevated amino acid levels in the HF plasma, Phe, Met, Lys, and Gly, were significantly reduced by the cultured hepatocytes. The results indicate that the use of primary cultured pig hepatocytes is a step toward a hybrid artificial liver system, and a promising candidate as a bioreactor.
A case of pure struma ovarii is reported with its CT, magnetic resonance (MR), and pathologic findings. Both MR and CT revealed a complex mass composed of solid elements and multiple cysts; CT revealed calcifications not apparent on MR.
Monolayer cultures of hepatocytes were shown to have good function when compared with suspended cells. The authors manufactured a new hybrid artificial liver containing hepatocyte monolayers and evaluated its function. Hepatocytes isolated from an adult dog liver were cultured on collagen coated borosilicated glass (10 X 20 X 0.04 cm). A long-stroke artificial liver module was constructed by stacking 200 glass plates bearing hepatocytes, which were viable and functioned well during 4 weeks in perfusion culture; glyconeogenesis = 110 ng/micrograms DNA/min, urea synthesis = 3.6 ng/micrograms DNA/min and albumin synthesis = 29 micrograms/10(6) cells/day at the 5th day of perfusion. The levels were maintained for 2 weeks. The new device was applied to anhepatic dogs (Group 3) and compared with untreated (Group 1) and plasma exchange dogs (Group 2). The survival times were 21.3 +/- 5.6 hours in Group 1 (N = 6), 27.8 +/- 4.0 hours in Group 2 (N = 3), and 55.0 +/- 10.3 hours in Group 3 (N = 4). The longest survival was 65 hours. Serum ammonia increased to over 2,000 micrograms/dl after 12 hours in Groups 1 and 2, but remained under 400 micrograms/dl in Group 3. This new type of hybrid system may be a pilot design for the complete artificial liver.
The clinical and cytologic findings in ten cases of primary fallopian tube carcinoma, a very rare malignancy, are presented. All ten patients had vaginal pool (V), cervical (C), endocervical (E) and endometrial aspiration (EA) smears examined preoperatively; peritoneal smears were also prepared from cul-de-sac fluid aspirated during surgery. In the preoperative cytodiagnosis, some of V, C, E and EA smears were positive for malignant cells in six of the ten patients (60%). Examination of the EA smear was the most effective means of discovering this disease. A watery discharge was noted in two patients, both of whom were negative in the preoperative cytodiagnosis. In such patients, it is necessary to repeat the smear examinations. The cytologic appearance of this disease is contrasted to that of endometrial carcinoma.
Between December 1968 and December 1983, the authors treated 30 patients requiring gastrectomy for carcinoma of the postoperative stomach. The patients were divided into two groups: 13 patients were operated on for primary carcinoma lesions (Group A) and 17 patients for benign lesions (Group B). Respective areas of carcinoma development and length of time from initial operation to the discovery of carcinoma of the postoperative stomach were investigated. A period of less than 10 years elapsed in 11 of the patients (84.6%) in Group A and advanced carcinoma developed in the area of the suture in many patients. In contrast, a period of more than 10 years elapsed in 16 of the patients (94.1%) in Group B. Early carcinoma was found in four out of six patients after 10-20 years, whereas advanced carcinoma was found in six out of 10 patients after more than 20 years. Carcinoma developed in the gastric remnant or the area of anastomosis in many patients. This suggests that carcinoma that is discovered within 10 years after operation might have been missed at the initial operation or might have recurred. We therefore defined carcinoma discovered more than 10 years after operation as primary stump carcinoma. To determine areas of carcinoma development and macroscopic findings, 91 patients with primary stump carcinoma (consisting of 18 of our patients and 73 patients from the Japanese literature) were compared with those with cancer in the upper third of the stomach (unoperated) (181 of our patients). Primary stump carcinoma was often found in the area anastomosed with the Billroth II operation, and primary early cancer in the gastric stump tended to be protuberant rather than excavative.(ABSTRACT TRUNCATED AT 250 WORDS)
An autopsy case of dementia beginning with right hand muscle atrophy was reported. A 42-year-old woman with no family history of neurologic disease developed weakness of the right hand at age 30, and was diagnosed as having amyotrophic lateral sclerosis (ALS). The weakness and atrophy spread to the four extremities subsequently. At age 36, she could not walk without assistance. At age 38, she was first noted as having dementia with forced crying, and she also showed generalized muscle weakness and atrophy. She rapidly developed akinetic mutism, and died of respiratory failure at age 42, 12 years after the onset of the symptoms. Macroscopically, the brain showed fronto-temporal atrophy. Microscopic examination revealed numerous intracytoplasmic inclusions throughout the central nervous system (CNS) including anterior horn of the spinal cord. The inclusions were stained moderate to dark brown with silver stain. Electron microscopically, they consisted of fibrils covered along most of the length with granular and fuzzy materials. This case was thought to be difficult to categorize in any known neuro-degenerative diseases. We proposed the case to be "atypical Pick's disease" with ALS features. This case might be a new entity of neuro-degenerative disease.
The effect of the type of prosthodontic treatment on glove perforation and proteinaceous contamination of gloves was investigated for 364 prosthodontic treatments using poly(vinyl chloride) plastic (218 occasions) and latex gloves (146 occasions). The amount of protein contamination on plastic or latex gloves varied depending on the prosthodontic treatment performed and the patient treated. As determined directly, it averaged from approximately 800 to 1,500 micrograms per treatment, and the maximum value of protein contamination was more than 4,000 micrograms, corresponding to the amount of protein in 1.5 mL of saliva or 0.1 mL of serum. The perforation of plastic gloves was observed in 83.0% of the total occasions, and the perforation went unrecognized 96.1% of the time. In contrast, the proportion of glove perforation for latex gloves was 12.3% and the proportion of unrecognized perforation of latex gloves was 5.4%. The results suggest that latex gloves are effective in reducing the risk of cross-infection. Nevertheless, prosthodontists still have a potential risk of being exposed to bodily fluids, without being aware of glove perforation, at least once in every 20 treatments, even if latex gloves are worn.
Chemical cleansing has been suggested as one of the most effective methods for plaque control, particularly for resilient denture-lining materials. These materials are known to be easily colonized and infected by Candida albicans. Maintaining the cleanliness of such materials is difficult because of porosity and incompatibility with some types of denture cleansers. Therefore, denture cleansers used for soft liners must address both microbiologic and physical requirements. This study evaluated the antifungal efficacy of 11 commercial denture cleansers on C albicans biofilm, studied the compatibility of tissue conditioners with denture cleansers, and makes suggestions for the chemical cleansing of dentures lined with tissue conditioners.
This study assessed the antifungal activity of seven commercial mouthrinses against Candida albicans, the organism often found in denture wearers with denture stomatitis. Screening for efficacy of growth inhibition found that five mouthrinses inhibited the growth of fungi, and their maximum inhibitory dilution values and the fungicidal activity were then determined. Two mouthrinses containing cetylpyridinium chloride were shown to be most effective after determination of the maximum inhibitory dilution and the test of fungicidal activity.