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Biomedical subjects

A M Tanaka

Publications and source records attributed to A M Tanaka.

7 recordsLinked to original sources
PubMed2000

Purification and characterization of a trypsin-like enzyme with fibrinolytic activity present in the abdomen of horn fly, Haematobia irritans irritans (Diptera: Muscidae).

This work describes the purification and characterization of a trypsin-like enzyme with fibrinolytic activity present in the abdomen of Haematobia irritans irritans (Diptera: Muscidae). The enzyme was purified using a one-step process, consisting of affinity chromatography on SBTI-Sepharose. The purified protease showed one major active proteinase band on reverse zymography with 0.15% gelatin, corresponding to a molecular mass of 25.5 kDa, with maximum activity at pH 9.0. The purified trypsin-like enzyme preferentially hydrolyzed synthetic substrates with arginine residue at the P1 position. The Km values determined for three different substrates were 1.88 x 10(-4), 1.28 x 10(-4), and 1.40 x 10(-4) M for H-alpha-benzoyl-Ile-Glu-Gly-Arg-p-nitroanilide (S2222), DL-Ile-Pro-Arg-p-nitroanilide (S2288), and DL-Phe-Pip-Arg-p-nitroanilide (S2238), respectively. The enzyme was strongly inhibited by typical serine proteinase inhibitors such as SB

Animals↗
PubMed1996

Purification of fibroblast growth factor-2 from human placenta using tri(n-butyl)phosphate and sodium cholate.

Tri(n-butyl)phosphate (TNBP) and sodium cholate (SC) mixtures have been used to inactivate lipid-enveloped viruses like HIV and hepatitis B. We exploited the use of this combination to purify fibroblast growth factor-2 (FGF-2) from human placenta. Human placentas were extracted in the presence of 0.3% TNBP/0.2% SC and the clarified homogenate was adsorbed to S-Sepharose. The active fractions were further loaded onto a heparin-Sepharose column and purified FGF-2 was eluted with 2.0 M NaCl. FGF-2 purified this way was indistinguishable from FGF-2 purified without TNBP/SC in the extraction step in terms of yield, specific activity and biological response. The lipid-enveloped vaccinia virus was used in a parallel experiment to evaluate the inactivation capacity of our protocol. Under the conditions described here, the combined use of TNBP/SC did not eliminate but reduced significantly the number of vaccinia virus PFUs by log 2-3.

3T3 Cells↗
PubMed1978

[Cutaneous dyschromia in three cases of phenylketonuria. Quantitative ultrastructural study of the basal layer of the epidermis (author's transl)].

The authors have studied skin color modifications in 3 cases of phenylketonuria and have observed the characteristic changes; fair skin and fair hair. In addition they noted hundred of pigmented pin point or slightly larger patches in the two more affected patients, in the areas exposed to sunshine. With regard to the ultrastructural study of the epidermis basal layer, the proportion of melanocytes in the two most severe cases was slightly higher than in the normal skin of 6 control subjects. Langerhans cells could not be acertained. The more severe was the disease the greater was the tendency for a lower proportion of keratinocytes containing melanin. There is a certain parallelism between the skin color modifications the biochemical examinations (blood level of phenylalanin and tyrosine) and the ultrastructural changes. The higher the blood level of phenlalanine and/or the more pronounced the disorders of skin color, the more evident would be the ultrastructural changes: higher proportion of melanocytes that usually do not produce the melanosomes, and lower percentage of keratinocytes with melanin. On the other hand, the ultrastructure of the basal layer would suggest the seriousness of clinical manifestations and/or the intesity of the metabolic error.

Child↗
PubMedDate not supplied

Association of HLA-A, -B, -C genes and TNF microsatellite polymorphism with psoriasis vulgaris: a study of genetic risk in Brazilian patients.

This study investigated the genetic association of HLA class I genes and TNF-alpha microsatellites. HLA-A, -B, -C typing was carried out in 92 psoriasis vulgaris patients and 160 healthy individuals using a PCR-SSP method. 70 patients and 71 controls were typed for five microsatellite polymorphisms, TNFa-e. HLA-B*13 Cw*06, HLA-B*57 Cw*06 and HLA-B*39 Cw*12 haplotypes were found to be increased in patients with psoriasis type I when compared to controls, which could determine the susceptibility to development of psoriasis. TNFa4, TNFb1, TNFe1 and TNFa2 b1 c2 d4 e1 haplotypes showed a decreased frequency (p < 0.05) in psoriasis patients when compared to controls. HLA-B*13 allele and HLA-B*13 Cw*06, TNFa11 b4 c1 d3 e3 haplotypes showed increased frequencies (p < 0.05) in patients with type II psoriasis, which suggests susceptibility to the onset of psoriasis. Our results detected polymorphisms of the HLA class I and microsatellite TNF locus which could be markers of genetic predisposition to the disease.

Adolescent↗