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Biomedical subjects

N Seo

Publications and source records attributed to N Seo.

98 records · Page 6Linked to original sources
PubMed1969

Sporulation, heat resistance, and biological properties of Clostridium perfringens.

A sporulation medium for 134 Clostridium perfringens strains, including types A, B, C, D, E, and F, was devised according to Grelet's observation that sporulation occurred when cultural environment became limited in any nutritional requirement indispensable for the growth of the organism. Sporulation took place most prominently when 10% cooked-meat broth (pH 7.2) containing 3% Proteose Peptone and 1% glucose was used for the preculture and 2% Poli Peptone medium (pH 7.8) was used for the subculture medium. Sometimes, terminal spores could be observed. A correlation between sporulation and heat resistance was examined by use of C. perfringens strains isolated from samples heated at different temperatures. Almost all strains isolated from unheated samples and from those heated at lower temperatures gave rise to spores in our sporulation medium, but the spores were weakly heat-resistant, whereas strains isolated from samples heated at 100 C for 60 min were highly heat-resistant but sporulated poorly. A majority of these heat-resistant strains were non-gelatinolytic and definitely salicin-fermenting.

Clostridium perfringens↗
PubMedDate not supplied

Hyporesponsiveness of peripheral blood lymphocytes to streptococcal superantigens in patients with guttate psoriasis: evidence for systemic stimulation of T cells with superantigens released from focally infecting Streptococcus pyogenes.

Throat infection with Streptococcus pyogenes is the most important trigger for acute guttate psoriasis. We examined the in vitro responses of peripheral blood mononuclear cells (PBMC) to streptococcal superantigens, SPEA and SPEC, and staphylococcal superantigens, SEB and TSST-1, in patients with guttate psoriasis, in patients with chronic plaque psoriasis, and in healthy subjects. PBMC from patients with guttate psoriasis responded poorly to SPEA and SPEC at concentrations of 0.1 and 1 ng/ml as compared with those from patients with plaque psoriasis, but showed high responses to SEB and TSST-1. The hyporesponsiveness recovered after improvement of the skin eruption. There was no significant difference between guttate and chronic types of psoriasis in the percentage of circulating T-cell receptor BV2 or BV8-bearing T cells, responsive to streptococcal superantigens, indicating that T-cell clonal anergy was a mechanism underlying the hyporesponsiveness. Our results suggest that superantigens released from focally infecting S. pyogenes induce a transient activation of relevant T cells, leading to the development of skin eruption and, subsequently, temporary T-cell anergy to these toxins.

Adult↗
PubMedDate not supplied

Tubulin and high molecular weight microtubule-associated proteins as endogenous substrates for protein carboxymethyltransferase in brain.

The endogenous substrate for protein carboxymethyltransferase in brain was examined. Several polypeptides were methylated when brain slices were incubated with L-methionine or when subcellular fractions of brain, such as the cytosolic fraction, were incubated with S-adenosyl L-methionine. Two methyl-accepting proteins in the cytoplasm were identified as tubulin and high molecular weight microtubule-associated proteins (300 kDa), which are components of microtubules. Tubulin behaved as a 43 kDa protein in acidic polyacrylamide gel electrophoresis, but as a 55 kDa protein in SDS-polyacrylamide gel electrophoresis. The methyl moiety transferred to these proteins from L-methionine was labile at alkaline pH. The high molecular weight microtubule-associated proteins showed higher methyl-accepting activity than tubulin or ovalbumin, which was used as a standard substrate: about 20 mmol of high molecular weight microtubule-associated proteins, 2 mmol of tubulin and 10 mmol of ovalbumin were methylated per mol of each protein in 30 min under the experimental conditions used.

Animals↗
PubMedDate not supplied

Subcutaneous seeding of small hepatocellular carcinoma after fine needle aspiration biopsy.

Ultrasonically guided fine needle (21 gauge) aspiration biopsy (FNAB) was performed on a patient with a hepatocellular carcinoma (HCC) measuring 1.5 x 1.5 cm in segment VI of the liver. The tumour was located just beneath the liver surface. Subsegmentectomy of segment VI was performed. Twelve months after the biopsy and 10 months after the operation, levels of alpha-fetoprotein (AFP) and protein induced by Vitamin K absence or antagonist-II (PIVKA-II) increased gradually without any evidence of recurrence of HCC in the liver. Thirteen months after the biopsy, the patient palpated a hard subcutaneous nodule 1.5 cm in diameter in the right lower anterior chest wall at the insertion site of the biopsy needle. A subcutaneous tumour was excised and histological examination revealed moderately differentiated HCC. The levels of AFP and PIVKA-II normalized thereafter. These tumour markers were therefore useful for diagnosing the subcutaneous nodule as a metastatic HCC. The patient is currently doing well without further recurrence of HCC or needle-tract seeding 23 months after subsegmentectomy and 11 months after excision of the subcutaneous tumour.

Aged↗