Histamine and tyramine degradation by food fermenting microorganisms.

Microorganisms suitable for food fermentation were examined with regard to their potential to degrade histamine and tyramine. Out of 64 lactic acid bacteria evaluated in this study, 27 degraded histamine and one tyramine, respectively, with low activity. Among 32 strains of Brevibacterium linens and coryneform bacteria, 21 exhibited histamine and tyramine oxidase activity. None of 20 strains of Staphylococcus carnosus tested degraded histamine or tyramine. One strain out of nine strains of Geotrichum candidum degraded tyramine slightly. Among 44 strains of Micrococcus sp. examined, 17 degraded either one or two biogenic amines. In this study Micrococcus varians (M. varians) LTH 1540 exhibited the highest tyramine oxidase activity of all strains tested and was therefore investigated in detail. The enzyme was found to be located in the cytoplasm and was not membrane bound. The reaction end product p-hydroxyphenyl acetic acid was detected by HPLC analysis. An activity staining for the amine oxidase in a native polyacrylamide gel based on the formation of H2O2 during amine oxidation was developed. Resting cells of the strain exhibited optimal tyramine oxidase activity at a pH of 7 at 37-40 degrees C. The enzyme in the cell free extract had a pH optimum between 7-8. The enzyme activity was decreased by NaCl, glucose and hydralazine. Phenylethylamine and tryptamine were oxidized at lower concentrations than tyramine. The potential for amine degradation was not found to be associated with that of formation of biogenic amines, as 23 microorganisms with the ability to metabolise biogenic amines exhibited no decarboxylase activity toward histidine, tyrosine, phenylalanine, lysine or ornithine.

Erythrocyte apheresis in combination with elimination of fibrinogen and plasma proteins of higher molecular weight in macular disease and in uveal effusion syndrome.

Reduction of hematocrit as well as elimination of fibrinogen and plasma proteins of higher molecular weight are effective approaches in hemorheology. A combination of these therapeutical concepts was applied in one patient with uveal effusion syndrome and in 16 patients with maculopathy. The hematocrit was reduced by erythrocyte apheresis. Fibrinogen and plasma proteins were eliminated by plasma exchange. In the case of uveal effusion syndrome the filling of the scleral veins as well as the uveal effusion were reduced. Furthermore visual function was improved significantly. In 9 of the 16 patients with maculopathy a significant increase in visual acuity occurred. The therapy described lowers significantly the following parameters: hematocrit, fibrinogen, serum proteins, plasma viscosity, erythrocyte aggregation and apparent whole blood viscosity (native and standardized). In a multiple linear regression analysis we found correlations as follows: plasma viscosity correlates with fibrinogen and proteins of higher molecular weight (r = 0.82), erythrocyte aggregation with fibrinogen and proteins of higher molecular weight (r = 0.88), standardized apparent whole blood viscosity with fibrinogen and proteins of higher molecular weight (r = 0.88) and native apparent whole blood viscosity with hematocrit, fibrinogen and proteins of higher molecular weight (r = 0.91).