Tryptophan hydroxylase antibodies used in the diagnosis of carcinoid

The expression of tryptophan hydroxylase, the rate-limiting enzyme in the biosynthesis of serotonin, is described in a case of a 35 year-old patient with metastatic jejunal carcinoid. Immunohistochemically, monoclonal anti-tryptophan hydroxylase antibodies positively identified liver metastases of a neuroendocrine tumor. The cellular distribution of tryptophan hydroxylase was restricted exclusively to the cytoplasm of carcinoid cells, where it was found in large amounts. By means of immunoblotting, anti-tryptophan hydroxylase antibodies detected in samples from carcinoid tissue two closely migrating polypeptide bands with molecular weights of 26 kDa and 29 kDa, respectively. These two protein bands appear to represent proteolytically degraded polypeptides, since tryptophan hydroxylase is known for its extreme unstability in vitro. In our case, the immunohistochemical and biochemical identification of tryptophan hydroxylase in liver lesions of a neuroendocrine tumor permitted the correct diagnosis of a metastatic carcinoid.     

Thermal conductivity of several exfoliated graphites from 2 k to 300 k

The thermal conductivity of several exfoliated graphites (Grafoil, Foam, and UCAR-ZYX graphite) has been measured in the range 2 to 300 K. The temperature dependence of the thermal conductivity is similar to that of near-single-crystal pyrolytic graphite, but the value is two orders of magnitude lower.     

Einfluß von Schwefelverbindungen auf die Inhibition der Thermooxidation von Polypropylen

The influence of mixtures of substituted phenols with sulphur compounds on the thermooxidative stability of polypropylene was studied. Following substituted phenols were used: 4,4′-butylidene-bis(3-methyl-6-tert.-butylphenol), 2,2′-methylidene-bis(4-methyl-6-tert.-butylphenol) and 4,4′-thio-bis(3-methyl-6-tert.-butylphenol). As sulphur compounds phenylalkylsulphides, p-nitrophenylalkylsulphides and some other p-substituted phenylsulphides were used. The effect of these mixtures was studied at 180°C in oxygen atmosphere.     

Electron transport properties of palladium-ruthenium alloys from 50 mK to 4.2 K

The thermopowerS, resistivity , thermal conductivity , and thermoelectric ratioG of alloys nominally of 0.1, 0.5, 1.0, and 5 at % Ru in Pd have been measured from 50 mK to 4 K. The thermopowerS varies essentially linearly withT, and is only a slowly varying function of concentration up to 1 at % Ru. The characteristic thermopower of Ru in Pd for the 0.1 at % alloy is (0.23±0.01) T µ V/K. At temperatures below 0.15 K there are departures from linearity, presumably caused by magnetic impurities. In the same temperature rangeG shows large departures from the expected constant value. The Lorenz ratioL obtained from two independent sets of data,S/GT and /T, are in good agreement. Departures ofL from the Sommerfeld valueL ₀ are discussed.Work supported by the National Science Foundation under Grant number DMR-75-01584.     

Discriminatory classification of natural and anthropogenic waters in two U.K. estuaries

The ability to distinguish water inputs from both natural and anthropogenic sources was investigated in the complex environment of an urban estuary (Tyne) and a relatively pristine estuary (Tweed). We used a data set from a total of 11 estuarine transects, comprising measurements of bulk dissolved organic matter (dissolved organic carbon and nitrogen), dissolved nitrogen (total dissolved nitrogen, ammonium, nitrate+nitrite and dissolved organic nitrogen), optical absorbance measurements (a350, S290-350) and fluorescence excitation emission matrix measurements (fluorophores A, H, B and T intensity and A and H emission wavelength maxima). In order to investigate trends within the numerous parameters measured, multivariate statistics were employed. Principal components analyses showed 63.4% of the variability in the total data set can be explained by two sets of components and 74.9% of the variability by the spectrophotometric measurements alone. In both analyses the first component correlated to the mixing of terrestrial and marine waters and the second component was correlated to sources of pollution such as domestic sewage. Within the data set, river flow and terrestrially derived DOM were significantly correlated, and situations with high river input showed an increase in terrestrial signature in the estuary. Discriminant analyses were also carried out and indicated that 59.8% (total data set) and 53.3% (solely spectrophotometric data) of the samples can be correctly classified into their respective groups (water categories) assigned on the basis of salinity and sampling location. Overall the results clearly show the potential of spectrophotometric techniques to discriminate distinct water categories with different DOM characteristics. In particular, measurement of the fluorophore H emission maxima, the spectral slope parameter, S290-350, and fluorophores T and B intensity enabled discrimination of DOM from riverine, estuarine, marine, and sewage affected water categories. The results presented here indicate the ability of spectrophotometric data alone to distinguish between marine, anthropogenic and terrestrial DOM and distinguish terrestrial DOM from different catchments (Tyne vs. Tweed). With current advances in the in-situ deployment of absorbance and fluorescence spectroscopy it is anticipated that multivariate statistics will gain importance as a cost effective, powerful and diagnostic approach to assessing the distributions of water types and their associated DOM characteristics and fluxes at the land-ocean interface.