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Biomedical subjects

J E Fräki

Publications and source records attributed to J E Fräki.

9 recordsLinked to original sources

Proteinase binding and enhancing factor from human skin.

Fresh human skin extract made in salt solution after a prior buffer extraction was shown to enhance the hydrolysis of N-alpha-benzoyl-DL-arginine beta-naphthylamide (BANA) by trypsin. This trypsin enhancing effect was further shown to be both stabilizing and activating. After chromatography on Sephadex G-100, the trypsin binding factor was found in fractions of void volume. Protease binding took place in physiological and hypotonic but not in hypertonic NaCl-solutions (0.5 mol/l). The proteinase binding factor was further purified by trypsin-Sepharose 4 B affinity chromatography. It was found to bind also chymotrypsin and elastase and to be thermostable (100 degrees C for 20 min), precipitable at acidic pH (3.5), and by acetone and ammonium sulphate (60% saturation). The bound proteinases were found to preserve their hydrolytic activity towards protein substrates. Bound trypsin and chymotrypsin could completely be inhibited by soybean trypsin inhibitor. The binding factor did not react with anti-human-alfa2-macroglobulin antiserum from rabbit.

Benzoylarginine-2-Naphthylamide

Allergy to various components of topical preparations in stasis dermatitis and leg ulcer.

Patients suffering from stasis dermatitis and leg ulcers (192) were found to give an allergic reaction in epicutaneous tests to one or more components of topical preparations in 69.2% of cases. The most common reactions were obtained with neomycin 34.0% and its component framycetin 31.2%, wool alcohols 22.9%, balsam of Peru 21.4%, chlorquinaldon 16.7%, bacitracin 13.1%, chinoform 10.9%, dequalin 9.9%, formaldehyde 4.2% and parabens 3.6%. The incidence of allergic reactions reflects local use of preparations containing various allergens as well as their capacity to produce alllergy. Allergy may in some cases interfere with effective topical therapy. Debrisan dextran polymer beads were found to be suitable for treatment of ulcers of multiallergic patients without risk of contact allergy.

Administration, Topical

Proteolytic enzymes and plasminogen activator in melanoma.

Proteolytic activities were measured in extracts of human skin melanoma, lymphatic metastasis and in nonmalignant naevi by using various proteinase substrates as well as plasminogen activator assay. pH-optima for hydrolysis of various proteinase substrates by these tumors were found to be essentially the same as in healthy human skin. Melanoma extracts were found to especially readily hydrolyze N-alpha-benzoyl-DL-arginine beta-naphthylamine (BANA) at pH 5.8 in the presence of 1 mmol/l dithiothreitol and EDTA (cathepsin B1-like enzyme) as well as histones and p-tosyl-L-arginine methyl ester (TAME) at pH 7.5, and showed increased capacity to activate plasminogen when compared to nonmalignant naevus. The possible role of proteinases in malignant melanoma is discussed.

Humans

Alkaline phosphatase in the developing bursa of Fabricius. A comparative study of the cyclophosphamide- and testosterone-induced immunodeficiencies in the chick embryo.

The ontogeny of alkaline phosphatase in the bursa of Fabricius was studied by histochemical and biochemical methods. According to the quantitative determinations, the activity of alkaline phosphatase increased from the 11th to 17th day of incubation--that is, during the time of the lymphoid follicle formation in the developing bursa. The activity was localized in the mesenchymal tissue surrounding the lymphoid follicles. Testosterone given in ovo prevented the appearance of alkaline phosphatase in the bursal mesenchyme but had no effect on the activity of the embryonic liver. In contrast, in ovo treatment with cyclophosphamide had no effect on the alkaline phosphatase in the bursa. By using transplantation of embryonic bursal stem cells, it was further shown that, in contrast to cyclophosphamide, testosterone destroys the capacity of the bursa to serve as a differentiation site for the B-cell lineage. The results indicate that testosterone affects the stromal cells of the bursa, whereas cyclophosphamide destroys only the lymphoid population undergoing differentiation and leaves the bursal stroma intact.

Alkaline Phosphatase

Human skin proteases: effect of separated proteases on vascular permeability and leukocyte emigration in skin.

The effect of human skin proteases on vascular permeability and leukocyte emigration in rabbit skin was investigated. The alkaline protease of human skin capable of hydrolysing trypsin substrate effectively increased vascular permeability. This effect was not inhibited by antihistamine, but almost totally so by Trasylol. The reaction was protracted. Leukocyte emigration in skin, primarily of PMN-cells at 12 hrs, and later a migration of mononuclear cells, also resulted. Swelling of the dermal fibres was noted. The alkaline protease of human skin capable of hydrolysing chymotrypsin substrate also increased vascular permeability, but this phenomenon was effectively inhibited by antihistamine and the reaction was of brief duration. The leukocyte emigration caused by this enzyme was remarkable. The acid proteases of human skin resembling cathepsin B1 and D also caused brief increased vascular permeability, which was effectively inhibited by antihistamine. The cellular reactions to these acid proteases were mild. The role of protease inhibitors in skin in the enzyme reactions is discussed.

Animals

Human skin proteases. Fractionation of psoriasis scale proteases and separation of a plasminogen activator and a histone hydrolysing protease.

Psoriatic scale proteases were found to be extracted effectively in salt solution (1 mol/l) containing Triton X-100 (5 g/l). The extraction in dilute buffer or sucrose yielded low activities. The acid (0.25 N H2SO4) and KSCN (2 mol/l) solutions effectively extracted plasminogen activator. Fibrinolysin was most active in salt (1 mol/l KCl) and in KSCN (2 mol/l) extracts. Psoriatic scale proteases were fractionated by Sephadex G-100 gel filtration and further by DEAE cellulose chromatography. Five different enzyme preparations were obtained. The first preparation, resembling cathepsin D, effectively hydrolysed hemoglobin at pH 3.5 and casein at pH 5.8 and was insensitive to protease modifiers. The second preparation effectively hydrolysed trypsin substrates (AGLME, TAME, BAEE and BANA) and also histone and casein at pH 7.2 and was inhibited by protease inhibitors, TLCK and E-600. The third preparation hydrolysed histone and casein at pH 10.2 and was effectively inhibited by E-600 and partially by protease inhibitors and TPCK. The fourth preparation, resembling cathepsin B1, hydrolysed BANA and BAEE at pH 5.8 and was activated by SH-reagents and EDTA. The fifth enzyme preparation hydrolysed ATEE and was inhibited by E-600 and TPCK. Plasminogen activator was found mainly in the second enzyme preparation and fibrinolysin activity in the third and fifth enzyme preparations. The second, third and fifth enzyme preparations were different from the enzymes found in healthy human skin. The proteases of psoriatic scale resemble those of tissue and cell cultures undergoing rapid cell division. The possible role of proteases in the increased cell division in psoriasis plaque is discussed.

Histones

Human skin proteases. Separation and characterization of two acid proteases resembling cathepsin B1 and cathepsin D and of an inhibitor of cathepsin B1.

Two acid proteases, one hydrolysing hemoglobin and the other hydrolysing benzoyl arginine naphthyamide (BANA), were separated and partially purified from human skin buffer extract. The acid protease hydrolysing hemoglobin was purified about 190 fold by Sephadex G-100 gel filtration and DEAE-cellulose chromatography. It hydrolysed hemoglobin at pH 3.5, casein at pH 5.8 and skin protein substrate at pH 6.0. It did not markedly hydrolyse synthetic protease substrates. The molecular size of this protease was 38000. The protease was insensitive to common protease modifiers and closely resembles cathepsin D purified from other organs. The BANA-hydrolysing acid protease was purified about 760 fold by Sephadex G-100 gel filtration and affinity chromatography on organomercurial Sepharose 4B gel. It preferentially hydrolysed BAEE, BANA and BAA with an optimum at pH 5.8. The hydrolysis of BAPA, LeuNA and protein substrates was very low. This acid protease was found to be highly dependent on reducing agents, as DTT, and chelating agents, as EDTA, and was inhibited by pCMB and TLCK. The molecular size of the enzyme was 28000. This protease closely resembles cathepsin B1 purified from other organs. Human skin was also shown to contain a low activity of benzoyl arginine amide (BAA) hydrolysing acid protease with a molecular size of about 50000 and resembling cathepsin B2. Human skin contained an inhibitor with a molecular size of about 13000 against human skin cathepsin B1. This inhibitor did not inhibit trypsin, chymotrypsin or skin proteases other than cathepsin B1.

Benzoylarginine-2-Naphthylamide