Development of mass spectrometric techniques applicable to the search for organic matter in the lunar crust

Data processing techniques were developed to measure with high precision and sensitivity the line spectra produced by a high resolution mass spectrometer. The most important aspect of this phase was the interfacing of a modified precision microphotometer-comparator with a computer and the improvement of existing software to serve the special needs of the investigation of lunar samples. In addition, a gas-chromatograph mass spectrometer system was interfaced with the same computer to allow continuous recording of mass spectra on a gas chromatographic effluent and efficient evaluation of the resulting data. These techniques were then used to detect and identify organic compounds present in the samples returned by the Apollo 11 and 12 missions

Terpenes. IX. The Conversion of Sclareol to Manool

Acetylation of sclareol with acetic anhydride in the presence o.f pyridine gives mainly sclareoldiacetate and manoolacetate. Reduction of the latter with lithium aluminum hydride yields manool. The stereochemistry of the two diterpenes is discussed

Electronic Instrumentation

Contains reports on status of research and three research projects.National Institutes of Health (Grant 1 505 FR07047-01)Electronic Instrumentation Group of the Research Laboratory of Electronics in research under NIH Grant 1 505 FR07047-0

The site of attachment of retinal in bacteriorhodopsin. The epsilon-amino group in Lys-41 is not required for proton translocation

Chymotryptic fragments C-1 (amino acids 72-248) and C-2 (amino acids 1-71) of bacteriorhodopsin have been shown previously to reassociate so as to regenerate the native bacteriorhodopsin chromophore in lipid/detergent mixtures and to form functional proton-translocating vesicles. The fragment C-2 has now been selectively methylated with formaldehyde and sodium cyanoborohydride to give the epsilon-dimethylamino derivatives of Lys-30, 40, and 41 in 96-99% average yield. The methylated and unmethylated C-2 fragments were identical in their ability to reassociate with fragment C-1 and retinal to regenerate the bacteriorhodopsin chromophore and to form functional proton-translocating vesicles. In contrast, dimethylation of the lysine residues of the C-1 fragment gave a derivative which did not form an active complex with unmethylated C-2. We conclude that the epsilon-amino group in Lys-41 is not required for Schiff's base formation with retinal at any step in the light-driven proton-translocation cycle

Electronic Instrumentation

Contains research objectives and reports on four research projects.National Institutes of Health (Grant 1 505 FR07047-01

Fecal Metaproteomics Reveals Reduced Gut Inflammation and Changed Microbial Metabolism Following Lifestyle-Induced Weight Loss

Gut microbiota-mediated inflammation promotes obesity-associated low-grade inflammation, which represents a hallmark of metabolic syndrome. To investigate if lifestyle-induced weight loss (WL) may modulate the gut microbiome composition and its interaction with the host on a functional level, we analyzed the fecal metaproteome of 33 individuals with metabolic syndrome in a longitudinal study before and after lifestyle-induced WL in a well-defined cohort. The 6-month WL intervention resulted in reduced BMI (−13.7%), improved insulin sensitivity (HOMA-IR, −46.1%), and reduced levels of circulating hsCRP (−39.9%), indicating metabolic syndrome reversal. The metaprotein spectra revealed a decrease of human proteins associated with gut inflammation. Taxonomic analysis revealed only minor changes in the bacterial composition with an increase of the families Desulfovibrionaceae, Leptospiraceae, Syntrophomonadaceae, Thermotogaceae and Verrucomicrobiaceae. Yet we detected an increased abundance of microbial metaprotein spectra that suggest an enhanced hydrolysis of complex carbohydrates. Hence, lifestyle-induced WL was associated with reduced gut inflammation and functional changes of human and microbial enzymes for carbohydrate hydrolysis while the taxonomic composition of the gut microbiome remained almost stable. The metaproteomics workflow has proven to be a suitable method for monitoring inflammatory changes in the fecal metaproteome

Circulating omentin as a novel biomarker for colorectal cancer risk: Data from the EPIC - Potsdam cohort study

Omentin is a novel biomarker shown to exert metabolic, inflammatory and immune-related properties, and thereby could be implicated in the risk of colorectal cancer (CRC). So far, the association between omentin and CRC risk has not been evaluated in prospective cohort studies. We investigated the association between pre-diagnostic plasma omentin concentrations and risk of CRC in a case-cohort comprising 251 incident CRC cases diagnosed over a mean follow-up time of 10.4 years and 2,295 persons who remained free of cancer in the European Prospective Investigation into Cancer and Nutrition-Potsdam study. Hazard ratios as a measure of relative risk (RR) and 95% confidence intervals (CI-s) were computed using a Prentice modified Cox regression. In a model adjusted for established CRC risk factors, age, sex, education, dietary and lifestyle factors, body mass index (BMI) and waist circumference, higher omentin concentrations were associated with a higher CRC risk (RRcontinuously per doubling of omentin concentrations=1.98, 95%CI: 1.45-2.73). Additional adjustment for metabolic biomarkers, including glycated hemoglobin, high-density lipoprotein cholesterol and C-reactive protein, did not alter the results. In stratified analyses, the positive association between omentin and CRC risk was retained in participants with BMI< 30 (RRcontinuously per doubling of omentin concentrations=2.26; 95%CI: 1.57-3.27), whereas among participants with BMI{greater than or equal to} 30 no association was revealed (RRcontinuously per doubling of omentin concentrations =1.07; 95%CI: 0.63-1.83; Pinteraction= 0.005). These novel findings provide the first lines of evidence for an independent association between pre-diagnostic omentin concentrations and CRC risk and suggest a potential interaction with the adiposity state of the individual

Novel model of neuronal bioenergetics: postsynaptic utilization of glucose but not lactate correlates positively with Ca2+ signalling in cultured mouse glutamatergic neurons

We have previously investigated the relative roles of extracellular glucose and lactate as fuels for glutamatergic neurons during synaptic activity. The conclusion from these studies was that cultured glutamatergic neurons utilize glucose rather than lactate during NMDA (N-methyl-d-aspartate)-induced synaptic activity and that lactate alone is not able to support neurotransmitter glutamate homoeostasis. Subsequently, a model was proposed to explain these results at the cellular level. In brief, the intermittent rises in intracellular Ca2+ during activation cause influx of Ca2+ into the mitochondrial matrix thus activating the tricarboxylic acid cycle dehydrogenases. This will lead to a lower activity of the MASH (malate–aspartate shuttle), which in turn will result in anaerobic glycolysis and lactate production rather than lactate utilization. In the present work, we have investigated the effect of an ionomycin-induced increase in intracellular Ca2+ (i.e. independent of synaptic activity) on neuronal energy metabolism employing 13C-labelled glucose and lactate and subsequent mass spectrometric analysis of labelling in glutamate, alanine and lactate. The results demonstrate that glucose utilization is positively correlated with intracellular Ca2+ whereas lactate utilization is not. This result lends further support for a significant role of glucose in neuronal bioenergetics and that Ca2+ signalling may control the switch between glucose and lactate utilization during synaptic activity. Based on the results, we propose a compartmentalized CiMASH (Ca2+-induced limitation of the MASH) model that includes intracellular compartmentation of glucose and lactate metabolism. We define pre- and post-synaptic compartments metabolizing glucose and glucose plus lactate respectively in which the latter displays a positive correlation between oxidative metabolism of glucose and Ca2+ signalling