correspondence between case reports and fatality data. These data also establish that mortality rates are not affected by epidemic phase 24. Further confirmation of these results is provided by an analysis of the Aberdeen data (N.B.M-B., P.R. and B.T.G., manuscript in preparation). Concerning infection-induced mortality rates, classic work by Butler 24 , Bartlett 25 , Creighton 5 and others indicates significant mortality due to measles and whooping cough during these periods. Estimates of case fatality rates for measles vary widely, from 1-2% in the postwar era up to 46% prewar 14,26,27 , whereas estimates for whooping cough are in the 3-15% range 24. Data analysis These time series contain a substantial annual component and are further complicated by increasing population sizes over the two periods examined. Hence, analyses of the relationship between measles and whooping cough outbreaks were carried out on de-trended data. We used three separate methods. First, Pearson correlation coefficients were estimated for data aggregated over each epidemic year (October to October). Second, we carried out a linear regression of annual counts of measles against whooping cough and used the slope as a measure of synchrony. The results of this technique were qualitatively identical to those of the Pearson correlation, so we present only those. Finally, we also used Wavelet spectra to explore phase differences between filtered time series 28,29. Further information can be found in the Supplementary Information.

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Aims/hypothesis In humans, one of the hallmarks of type 2 diabetes is a reduced plasma concentration of HDL and its major protein component, apolipoprotein A

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Oxidative stress plays an important role in the formation of abdominal aortic aneurysm (AAA), and we have recently established a causal role of uncoupled eNOS in this severe human disease. We have also shown that activation of NADPH oxidase (NOX) lies upstream of uncoupled eNOS. Therefore, identification of the specific NOX isoforms that are required for eNOS uncoupling and AAA formation would ultimately lead to novel therapies for AAA. In the present study, we used the Ang II infused hph-1 mice to examine the roles of NOX isoforms in the development of AAA. We generated double mutants of hph-1-NOX1, hph-1-NOX2, hph-1-p47phox, and hph-1-NOX4. After two weeks of Ang II infusion, the incidence rate of AAA substantially dropped from 76.5% in Ang II infused hph-1 mice (n=34) to 11.1%, 15.0%, 9.5% and 0% in hph-1-NOX1 (n=27), hph-1-NOX2 (n=40), hph-1-p47phox (n=21), and hph-1-NOX4 (n=33) double mutant mice, respectively. The size of abdominal aortas of the four double mutant mice, determined by ultrasound analyses, was significantly smaller than the hph-1 mice. Aortic nitric oxide and H4B bioavailabilities were markedly improved in the double mutants, while superoxide production and eNOS uncoupling activity were substantially diminished. These effects seemed attributed to an endothelial specific restoration of dihydrofolate reductase expression and activity, deficiency of which has been shown to induce eNOS uncoupling and AAA formation in both Ang II-infused hph-1 and apoE null animals. In addition, over-expression of human NOX4 N129S or T555S mutant newly identified in aneurysm patients increased hydrogen peroxide production, further implicating a relationship between NOX and human aneurysm. Taken together, these data indicate that NOX isoforms 1, 2 or 4 lies upstream of dihydrofolate reductase deficiency and eNOS uncoupling to induce AAA formation. These findings may promote development of novel therapeutics for the treatment of the disease by inhibiting NOX signaling.

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Glycosphingolipids (GSL) on the surface of cells are important receptors in antigen/microbial recognition and cell adhesion. However, their functional characterization is often challenging. We have developed a catch-and-release electrospray ionization mass spectrometry (CaR-ESI-MS) assay for the identification of specific interactions between water-soluble proteins or protein complexes with GSL incorporated into nanodiscs. The specificity and sensitivity of the assay is demonstrated for interactions involving cholera toxin and Shiga toxin, with their natural GSL receptors, the ganglioside GM1, and the globotriaosylceramide Gb3, respectively. The detection of binding between cholera toxin and GM1 within a mixture of lipids extracted from cell membranes highlights the potential of this assay for the discovery of biologically relevant protein-GSL interactions.

Hypertension and abdominal aortic aneurysm (AAA) are severe cardiovascular diseases with incompletely defined molecular mechanisms. In the current study we generated dihydrofolate reductase (DHFR) knockout mice for the first time to examine its potential contribution to the development of hypertension and AAA, as well as the underlying molecular mechanisms. Whereas the homozygote knockout mice were embryonically lethal, the heterozygote knockout mice had global reduction in DHFR protein expression and activity. Angiotensin II infusion into these animals resulted in substantially exaggerated elevation in blood pressure and development of AAA, which was accompanied by excessive eNOS uncoupling activity (featured by significantly impaired tetrahydrobiopterin and nitric oxide bioavailability), vascular remodeling (MMP2 activation, medial elastin breakdown and adventitial fibrosis) and inflammation (macrophage infiltration). Importantly, scavenging of mitochondrial reactive oxygen species with Mito-Tempo in vivo completely abrogated development of hypertension and AAA in DHFR knockout mice, indicating a novel role of mitochondria in mediating hypertension and AAA downstream of DHFR deficiency-dependent eNOS uncoupling. These data for the first time demonstrate that targeting DHFR-deficiency driven mitochondrial dysfunction may represent an innovative therapeutic option for the treatment of AAA and hypertension.