Other Biologically Active Materials

Several other biologically active materials have been described in the human and animal stomach. However, little information is available as to their nature or the mechanism of activity. The available data on these little-explored materials will be presented here, although the evidence submitted is not always adequate and convincing. 

Osgood demonstrated that pernicious anemia serum delays maturation of megaloblastic bone marrow (see LI). The work of Callender and Lajtha (see G20) points out that addition of normal gastric juice potentiates the effect of vitamin B12 in counteracting this maturation-delaying effect of pernicious anemia serum. A B12 binder separated from normal gastric juice by electrophoresis or ammonium sulfate precipitation was also shown to enhance the B12 effect on maturation of the erythro-blasts, when added to bone marrow (P2, P3). The relation of this maturation-promoting factor to Castle s intrinsic factor is not clearly defined (see G20). 

Migration of Leucocytes and Maturation of Bed Cell-Stimulating Factor 

Stimulated by milk and raw meat, and at lowest concentration after subcutaneous administration of histamine. In patients with posthemorrhagic anemia, its concentration in gastric juice decreases sharply with multiple blood transfusion and in polycythemia, the concentration increases. As shown in Pavlov and Heidenhain pouches, the formation of this factor is under the influence of the vagus. Denervation of the spleen is reported to lead to its complete, though transient, disappearance from gastric juice. 

Mice and rats, rendered anemic by phenylhydrazine poisoning, were given oral mucin preparations from hog gastric mucosa, which significantly accelerated hematological remission (C27). This effect was related to a modification of intestinal flora or to an improvement of intestinal absorption of iron or vitamin B12. 

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It is well known that blending is effective and convenient method to improve performance of polymer materials (41). The active psyUium gel fiactionation and enzyme modification studies have shown that psylliiun can possibly be modified into other biologically active materials. Novel bioKX>mponent filnes can be develrqied witii optimized water absorption and tensile properties by possibly fusing psyllium with other fil e forming biomaterials. 

Chang, T.M.S. (1977a), Experimental therapy using semipermeable microcapsules containing enzymes and other biologically active material. In Biomedical Applications of Immobilised Enzymes and Proteins Vol. 1 (ed. T.M.S. Chang), Plenum Press, New York and London, Chapter 11, pp. 147-162. 

Hydrazine and its derivatives find considerable use in the synthesis of biologically active materials, dyestuff intermediates and other organic derivatives. Reactions of aldehydes to form hydrazides (RCH=NNH2) and azines (RCH=NN=CHR) are well known in organic chemistry, as is the use of hydrazine and its derivatives in the synthesis of heterocyclic compounds. 

Fractions brought off the column with elutants ranging from 80% acetone in water to pure acetone (108 mg. of solids) contained most of the biologically active material. The solids in these fractions showed a yellow fluorescence when dissolved in concentrated sulfuric acid. Gibberellic acid (V) shows a similar fluorescence under these conditions, whereas gibberellin A4 and other fungal gibberellins do not. 

The existence of chirality in nature is of particular importance in numerous recognition processes, often illustrated by examples detectable by non-spectroscopic methods such as the different orange and lemon odors of R-(+)- and S-(-)-limonene, respectively (Fig. 3) [8]. As such, chiral discrimination is also of considerable consequence in the medical sciences, as often one enantiomer is pharmaceutically active whereas the other may show adverse side effects. A historic example is the anti-emetic activity of one of the enantiomers of thalidomide, while the other can cause fetal damage [9,10]. These considerations highlight the importance of chiral discrimination in the production of biologically active materials, whereas on the other hand, the design of routes to asymmetric synthesis presents an active challenge to synthetic chemists worldwide. 

R625 T. Maurer, TROSY and Other NMR Methods for Screening Biological Active Materials , Nachr.Chem., 2000, 48, 1336... 

Whitestone did evaluate many alternatives prior to choosing RO. They decided to use RO because the initial cost was low, maintenance requirements were low and operator attention was minimal compared to the alternatives. Whitestone also calculated that the operating costs, both in manpower needs and in actual chemicals and membrane replacement, was less than other alternatives. Since the RO system would be operating on biologically active materials it was decided that cleaning every 8 hours would be appropriate. Therefore, an automatic Clean-In-Place (CIP) system was developed and installed with the RO unit. There is typically a 1 01 reduction in permeate rate due to fouling prior to the time that Whitestone cleans the RO unit. 

The physicochemical change of the biologically active material resulting from the interaction with the analyte must be converted into an electrical output signal by an appropriate transducer. On the one hand, unspecific, but broadly applicable transducers may be used, which indicate general parameters such as reaction enthalpy (thermistor), mass change (piezoelectric crystal), or layer thickness (reflectometry). On the other hand, a specific indication may be achieved with potentio-metric or amperometric electrodes for species such as H+, OH-, CO2, NH3, or H2O2, or with optical methods such as photometry or fluori-metry. 

For the repeated use of enzymes, cells, antibodies, and other biologically active agents in analytical devices, numerous techniques for fixing them to carrier materials have been developed. Immobilization, particularly of enzymes, brings about a number of further advantages for their application in analytical chemistry ... 

In addition, studies from this and other laboratories illustrate that by mimicking hypothetical transition states one can develop exceptionally potent enzyme inhibitors. These compounds will advance our understanding of catalytic mechanisms, serve as probes for unraveling the roles of particular enzymes in catalytic processes, and allow their rapid purification. They are also promising commercially as pesticides, pesticide synergists, as well as pharmaceuticals. From such work it seems clear that both chemical and biotechnological approaches will be used alone and in combination in the development of biologically active materials. 

Fluorinated Steroids. The fluorination of steroids has been known to have profound effects on biological activity since the early work of Fried (40). Fluorinated steroids have been described in other reviews (111). The use of fluorination as a tool to enhance biological selectivity and to improve the utility of a biologically active material has been clearly demonstrated in studies of vitamin D. ... 

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