Preoperative mannan-binding lectin pathway and prognosis in colorectal cancer

Purpose: Deficiency of the mannan-binding lectin (MBL) pathway of innate immunity is associated with increased susceptibility to infections. In patients with colorectal cancer (CRC), postoperative infection is associated with poor prognosis. The aim of the present study was to evaluate (1) the relation between the MBL pathway and postoperative infectious complications and survival of patients resected for CRC, and (2) the role of MBL in acute phase response compared to C-reactive protein (CRP). Methods: Preoperative MBL concentration, MBL-associated serine protease (MBL/MASP) activity and CRP were determined in serum from 611 patients and 150 healthy controls. The patients were observed for 8 years. Postoperative infections, recurrence and survival were recorded. Results: The MBL pathway components were increased in the patients compared with the healthy controls (p<0.0001). Low MBL levels were predictive of pneumonia (p=0.01), and pneumonia (n=87) was associated with poor survival (p=0.003; HR=1.5; 95% CI, 1.1 to 1.9). MBL and MBL/MASP activity showed no correlation with CRP (Spearmans =0.02; 95% CI, –0.06 to 0.10). Conclusion: Low preoperative MBL levels are predictive of pneumonia, which is associated with poorer survival. MBL concentration and MBL/MASP activity was not predictive of other postoperative infections or long-term prognosis, and showed no correlation with CRP.     

Risk Factors for Hyperglycaemia in Pregnancy in Tamil Nadu,India

Introduction

Hyperglycaemia in pregnancy (HIP), i.e. gestational diabetes mellitus (GDM) and diabetes in pregnancy (DIP), increases the risk of various short- and long-term adverse outcomes. However, much remains to be understood about the role of different risk factors in development of HIP.

Objective

The aims of this observational study were to examine the role of potential risk factors for HIP, and to investigate whether any single or accumulated risk factor(s) could be used to predict HIP among women attending GDM screening at three centres in urban, semi-urban and rural Tamil Nadu, India.

Methodology

Pregnant women underwent a 75 g oral glucose tolerance test. Data on potential risk factors was collected and analysed using logistical regression analysis. Receiver operating characteristic (ROC) curves, sensitivity, specificity and predictive values were calculated for significant risk factors and a risk factor scoring variable was constructed.

Results

HIP was prevalent in 18.9% of the study population (16.3% GDM; 2.6% DIP). Increasing age and BMI as well as having a mother only or both parents with diabetes were significant independent risk factors for HIP. Among women attending the rural health centre a doubling of income corresponded to an 80% increased risk of HIP (OR 1.80, 95%CI 1.10–2.93; p = 0.019), whereas it was not significantly associated with HIP among women attending the other health centres. The performance of the individual risk factors and the constructed scoring variable differed substantially between the three health centres, but none of them were good enough to discriminate between those with and without HIP.

Conclusions

The findings highlight the importance of socio-economic circumstances and intergenerational risk transmission in the occurrence of HIP as well as the need for universal screening.     

Studies on beef heart ubiquinol-cytochrome c reductase. Quantification and distribution of the core proteins as determined by radioimmunoassay

Core proteins I (M_r 50 000) and II (M_r 47 000) were isolated from beef heart ubiquinol-cytochrome c reductase, and radioimmunoassays were developed for both. Immunoreplica experiments show that antisera against each protein react with a single peptide in both isolated Complex III and in mitochondria. Thus, core proteins are not aggregated forms of smaller peptides as suggested for the yeast protein (Jeffrey, A., Power, S. and Palmer, G., Biochem. Biophys. Res. Commun. (1979) 86, 271–277). Core proteins were quantitated in Complex III and in mitochondria using radioimmunoassay. Approx. 2 mol core protein II per mol core protein I were found. A molar ratio of 1 : 2 : 2 : 1 is suggested for core protein I : core protein II : cytochrome b : cytochrome c₁. Radioimmunoassay shows that the antibodies react as extensively with Complex III-bound core protein as with the isolated core proteins. In spite of this, the antibodies do not inhibit electron transport in submitochondrial particles or isolated Complex III, and they have no oligomycin- or uncoupler-like effects on submitochondrial particles oxidizing NADH. The combined results from radioimmunoassay and immunoreplica experiments strongly suggest, however, that core proteins are specifically associated with Complex III in the mitochondria, implying a specific role there.     

Forecasting phenology: from species variability to community patterns

Shifts in species' phenology in response to climate change have wide-ranging consequences for ecological systems. However, significant variability in species' responses, together with limited data, frustrates efforts to forecast the consequences of ongoing phenological changes. Herein, we use a case study of three North American plant communities to explore the implications of variability across levels of organisation (within and among species, and among communities) for forecasting responses to climate change. We show how despite significant variation among species in sensitivities to climate, comparable patterns emerge at the community level once regional climate drivers are accounted for. However, communities differ with respect to projected patterns of divergence and overlap among their species' phenological distributions in response to climate change. These analyses and a review of hypotheses suggest how explicit consideration of spatial scale and levels of biological organisation may help to understand and forecast phenological responses to climate change.