Isolierung und funktionelle Eigenschaften von Molkenproteinfraktionen

Zusammenfassung Die Fraktionierung von Molkenproteinkonzentrat mit Aceton wurde untersucht. Der pH-Wert und die Lösungsmittelkonzentration, bei der die Fällungen durchgeführt wurden, hatten den größ-ten Einfluß auf die Zusammensetzung von Präcipitaten und Überständen. Im Bereich von 25–33% Aceton (v/v) war eine begrenzte Fraktionierung der Molkenproteine möglich:-Lactalbumin und-Lactoglobulin wurden ausgefällt, während Blutserumalbumin in Lösung blieb. Der pH-Wert (Bereich 4,5–7,0) beeinflulßte neben den Proteinfraktionen auch andere Bestandteile des Molkenkonzentrats. Mit steigendem pH-Wert verringerte sich die Gesamt-N-Ausbeute im Präcipitat und der Gehalt an Calcium nahm zu, gleichzeitig verminderte sich die Resolubilisationsfähigkeit der ausgefällten Niederschläge.

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Isolation and functional properties of whey protein fractions

Summary The fractionation of whey protein concentrate by acetone was investigated. The composition of precipitates and supernates was strongly influenced by pH and acetone concentration during precipitation. A limited fractionation of the whey proteins occurred in the range of 25–33% acetone (v/v):-lactalbumins and-lactoglobulins were precipitated while blood serum albumins remained in solution. The pH value (range 4,5-7,0) influenced also other components of the whey concentrate beside the protein fractions. With increasing pH value the yield of total N in the precipitate decreased whereas the calcium content rose, this was accompanied by a decreased capability to redissolve the precipitates.

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Auszug aus der Dissertation H. A. Mehrens, TU München, 1980Sonderdruckanfragen an: Prof. Dr. H. Klostermeyer (Adresse siehe oben)     

Effects of extracellular cadmium on renal basolateral organic anion transport

The angiotensin-converting enzyme (ACE) inhibitor trandolapril, a non-sulfhydryl prodrug which is hydrolysed into trandolaprilat, was studied in 322 hypertensives of African-American descent using a double-blind, randomised, placebo-controlled, parallel study design. Following 6 weeks of double-blind treatment with placebo or 0.25 to 16 mg/day trandolapril, an analysis of drug effect on trough blood pressure (BP) stratified by age, gender, weight, pre-treatment plasma renin activity, and trandolaprilat concentration was performed. Two mg was the lowest effective trandolapril dose, whereas doses above 4 mg did not significantly reduce trough BP. Reduction in BP did not correlate with trough plasma trandolaprilat concentration. Pre-treatment plasma renin activity was not a reliable indicator of anti-hypertensive response, as similar reductions in BP occurred even in patients with the lowest renin levels. There were no observable differences based on age, gender or measurements of the renin-angiotensin-aldosterone axis. In conclusion, neither age, gender or plasma renin activity influenced anti-hypertensive response to angiotensin-converting enzyme inhibition in African-Americans.     

Serum antibody titers in a systemic lytic therapy with streptokinase

BACKGROUND: Anaphylactic reactions to streptokinase are rare but potentially life-threatening complications. Gamma E immunoglobulin (IgE) mediated mechanisms, probably due to streptococcal infections, have been implicated. We investigated the value of in vitro laboratory or dermatologic tests in predicting anaphylactic reactions due to streptokinase and the value of antistreptolysin titers (ASL) in predicting the amount of specific IgE (sIgE) and specific gamma G immunoglobulin (sIgG) neutralizing antibodies to streptokinase. METHODS: We measured serum levels of total IgE, streptokinase sIgE and sIgG, and ASL in 16 patients before and 9 and 41 days after streptokinase therapy. Immediately before therapy, intracutaneous testing with 100 IU streptokinase was done. RESULTS: Dermatologic testing did not identify patients prone to allergic reactions. Moreover, not all patients with increased sIgE levels had allergic reactions. These reactions were independent of the dose of streptokinase given. In spite of steroid prophylaxis, allergic reactions occurred in 3 of 16 patients, but none showed life-threatening anaphylaxis. Streptokinase sIgE and sIgG concentrations were closely related to ASL titers. CONCLUSIONS: Plasma levels of sIgG, sIgE, and ASL titers showed a good correlation. We believe ASL titers can be used for the estimation of neutralizing antibodies instead of streptokinase sIgG antibodies. Currently, no laboratory or dermatologic test allows reliable predictions of allergic reactions to streptokinase.     

Effects of pulp and paper mill effluents on the microplankton and microbial self-purification capabilities of the Biobío River, Chile

Most studies focus on the ecotoxicity of pulp and paper mill effluents, rather than on how they affect the physicochemical and biological structure and the intrinsic ecological capabilities of the receiving watercourses. We investigated the impact of such effluents on the water quality, microplankton system and microbial self-purification capacity (degradation of polymeric organic compounds via extracellular enzymes) of the Biobío River in Chile. The physicochemical impact on the water quality was indicated by raised conductivity, by the pollution of the water body with nitrate, nitrite and soluble reactive phosphorus, by the appearance of tannin and lignin, and by the steady accumulation of inorganic and organic suspended matter (SPM) along the river. From the biological structure of the microplankton system, very low and declining concentrations of chlorophyll a and heterotrophic flagellate densities were determined. The pulp and paper mill effluents introduced high bacterial abundances and biomass concentrations into the river water. This reflects the effective use made of the abundantly available inorganic and organic nutrients within this industrial and municipal process water by bacteria adapted to these extreme environments, additionally supported by concomitant low grazing pressure derivable from low heterotrophic flagellate abundances. Indeed, in one section of the river affected by a pulp mill, the plant was found to significantly contribute to the self-cleaning capacity of the river. However, this elevated degradation capacity was not enough to compensate for the additionally discharged organic material which, together with the toxic effects of the paper plant effluents, significantly interferes with the ecological status of the Biobío River.     

Raman chemical mapping of low-content active pharmaceutical ingredient formulations. III. Statistically optimized sampling and detection of polymorphic forms in tablets on stability

Several tablets of a formulation containing 1% w/w of the desired active pharmaceutical ingredient (API) form are spiked with minimal amounts of two different anhydrous polymorphs and an amorphous form. The amount of contaminant form was 2.5 to 10% of the total API concentration (0.025 to 0.1% w/w in the tablet), with five spiked tablets prepared. The presence of these contaminant particles are then identified using Raman microscopy/mapping. The entire surface of each of these tablets is Raman-probed through a grid based on our previous proposal (?a?i?, S.; Whitlock, M. Appl. Spectrosc.2008, 62, 916) about the minimal number of spectra to acquire that would guarantee identification of the targeted component (taking into account the limit of detection). All three forms have been clearly identified in the Raman mapping spectra of prepared "calibration" tablets; particularly of note is the 2.5% spike (0.025% w/w in the tablet) of the relatively weakly scattering amorphous form. The same method is then applied to packaged tablets on stability and demonstrates that none of the previously analyzed contaminant forms is detected, hence building confidence that the desired API form does not change during stability testing.