Diabetes mellitus, microalbuminuria, and subclinical cardiac disease: Identification and monitoring of individuals at risk of heart failure

Background-Patients with type 2 diabetes mellitus and elevated urinary albumin:creatinine ratio (ACR) have increased risk of heart failure. We hypothesized this was because of cardiac tissue changes rather than silent coronary artery disease. Methods and Results-In a case-controlled observational study 130 subjects including 50 ACR+ve diabetes mellitus patients with persistent microalbuminuria (ACR > 2.5 mg/mol in males and > 3.5 mg/mol in females, ≥2 measurements, no previous renin- angiotensin-aldosterone therapy, 50 ACR-ve diabetes mellitus patients and 30 controls underwent cardiovascular magnetic resonance for investigation of myocardial fibrosis, ischemia and infarction, and echocardiography. Thirty ACR+ve patients underwent further testing after 1-year treatment with renin-angiotensin-aldosterone blockade. Cardiac extracellular volume fraction, a measure of diffuse fibrosis, was higher in diabetes mellitus patients than controls (26.1±3.4% and 23.3±3.0% P=0.0002) and in ACR+ve than ACR-ve diabetes mellitus patients (27.2±4.1% versus 25.1±2.9%, P=0.004). ACR+ve patients also had lower E0 measured by echocardiography (8.2±1.9 cm/s versus 8.9±1.9 cm/s, P=0.04) and elevated high-sensitivity cardiac troponin T 18% versus 4% ≥14 ng/L (P=0.05). Rate of silent myocardial ischemia or infarction were not influenced by ACR status. Renin-angiotensin-aldosterone blockade was associated with increased left ventricular ejection fraction (59.3±7.8 to 61.5±8.7%, P=0.03) and decreased extracellular volume fraction (26.5±3.6 to 25.2±3.1, P=0.01) but no changes in diastolic function or high-sensitivity cardiac troponin T levels. Conclusions-Asymptomatic diabetes mellitus patients with persistent microalbuminuria have markers of diffuse cardiac fibrosis including elevated extracellular volume fraction, high-sensitivity cardiac troponin T, and diastolic dysfunction, which may in part be reversible by renin-angiotensin-aldosterone blockade. Increased risk in these patients may be mediated by subclinical changes in tissue structure and function

High energy emission from microquasars

The microquasar phenomenon is associated with the production of jets by X-ray binaries and, as such, may be associated with the majority of such systems. In this chapter we briefly outline the associations, definite, probable, possible, and speculative, between such jets and X-ray, gamma-ray and particle emission.Comment: Contributing chapter to the book Cosmic Gamma-Ray Sources, K.S. Cheng and G.E. Romero (eds.), to be published by Kluwer Academic Publishers, Dordrecht, 2004. (19 pages

Theoretical Investigations into Self-Organized Ordered Metallic Semi-Clusters Arrays on Metallic Substrate

Using the energy minimization calculations based on an interfacial potential and a first-principles total energy method, respectively, we show that (2 × 2)/(3 × 3) Pb/Cu(111) system is a stable structure among all the [(n − 1) × (n − 1)]/(n × n) Pb/Cu(111) (n = 2, 3,…, 12) structures. The electronic structure calculations indicate that self-organized ordered Pb semi-clusters arrays are formed on the first Pb monolayer of (2 × 2)/(3 × 3) Pb/Cu(111), which is due to a strain-release effect induced by the inherent misfits. The Pb semi-clusters structure can generate selective adsorption of atoms of semiconductor materials (e.g., Ge) around the semi-clusters, therefore, can be used as a template for the growth of nanoscale structures with a very short periodic length (7.67 Å)

Comparative morphological trade-offs between pre- and post-copulatory sexual selection in Giant hissing cockroaches (Tribe: Gromphadorhini)

Sperm competition theory predicts that animals face a trade-off between investment in weaponry and investment in ejaculate composition. Within the Madagascan giant hissing cockroaches (Tribe Gromphadorhini) differences in morphology exist that may indicate differing strategies of male-male competition. We compared relative pronotal horn length using high-resolution X-ray CT scanning data, relative testes mass, and male-male agonistic behaviour between two species of hissing cockroaches, Gromphadorhina oblongonota and Aeluropoda insignis. The gross morphology and behaviour of these two species indicated that G. oblongonota is selected for pre-copulatory mate acquisition and that A. insignis is selected for post-copulatory sperm competition. We found evidence for a trade-off when investing in testes mass vs. horn length between the species. The large, aggressive G. oblongonota follows a strategy of greater investment in weapons at the expense of testes mass while the smaller, less-aggressive A. insignis invests in relatively greater testes mass and less in pronotal weapon length. We also found evidence of a trade-off within each species, where individuals invest more heavily in weapon length at the expense of testes mass. These findings support the predictions of pre- and postcopulatory competitive investment trade-offs for a relatively understudied Tribe of cockroaches

Potentiation of photodynamic therapy of cancer by complement: the effect of γ-inulin

Host response elicited by photodynamic therapy (PDT) of cancerous lesions is a critical contributor to the clinical outcome, and complement system has emerged as its important element. Amplification of complement action was shown to improve tumour PDT response. In search of a clinically relevant complement activator for use as a PDT adjuvant, this study focused on γ-inulin and examined its effects on PDT response of mouse tumours. Intralesional γ-inulin (0.1 mg mouse−1) delivered immediately after PDT rivaled zymosan (potent classical complement activator) in delaying the recurrence of B16BL6 melanomas. This effect of γ-inulin was further enhanced by IFN-γ pretreatment. Tumour C3 protein levels, already elevated after individual PDT or γ-inulin treatments, increased much higher after their combination. With fibrosarcomas MCA205 and FsaR, adjuvant γ-inulin proved highly effective in reducing recurrence rates following PDT using four different photosensitisers (BPD, ce6, Photofrin, and mTHPC). At 3 days after PDT plus γ-inulin treatment, over 50% of cells found at the tumour site were CTLs engaged in killing specific targets via perforin–granzyme pathway. This study demonstrates that γ-inulin is highly effective PDT adjuvant and suggests that by amplifying the activation of complement system, this agent potentiates the development of CTL-mediated immunity against PDT-treated tumours