Effect of time post mortem on the concentration of endotoxin in rat organs: implications for sudden infant death syndrome (SIDS)

The aim of the study was to test the following hypotheses: (i) that endotoxin injected 40 min prior to death can be detected in rat organs post mortem and (ii) that endotoxin levels do not change with increasing time post mortem. Rats were injected with or without endotoxin in buffered saline, 40 min prior to being killed. Endotoxin levels in rat organs were assessed using a Limulus amoebocyte assay. The effect of storage time post mortem was assessed by following various storage regimes at 25 degrees C and 8 degrees C. Significant differences (P = < 0.001) in endotoxin levels of all samples tested were found between rats injected with and without endotoxin. A significant increase in detectable endotoxin was observed between 0 h and 6 h post mortem in rats injected with or without endotoxin. No difference in detectable endotoxin levels in the kidney, liver and spleen was observed from 30 h to 102 h post mortem in rats injected with or without endotoxin. In rats injected with endotoxin, detectable endotoxin levels in the heart were raised between 0 h and 6 h, 6 h and 54 h, and 30 h and 78 h. Endotoxin injected into rats 40 min prior to death can be detected post mortem. For rats injected with saline or endotoxin prior to death levels in the kidney, liver and spleen were not affected by storage at 8 degrees C for 30-102 h, after initial storage at room temperature for 6 h. Levels of endotoxin detected in the hearts of rats injected with saline were not affected by storage up to 102 h. In rats injected with endotoxin prior to death, detectable levels in the heart were significantly affected by increasing time in storage.     

Scaling laws of ambush predator ‘waiting’ behaviour are tuned to a common ecology

The decisions animals make about how long to wait between activities can determine the success of diverse behaviours such as foraging, group formation or risk avoidance. Remarkably, for diverse animal species, including humans, spontaneous patterns of waiting times show random ‘burstiness’ that appears scale-invariant across a broad set of scales. However, a general theory linking this phenomenon across the animal kingdom currently lacks an ecological basis. Here, we demonstrate from tracking the activities of 15 sympatric predator species (cephalopods, sharks, skates and teleosts) under natural and controlled conditions that bursty waiting times are an intrinsic spontaneous behaviour well approximated by heavy-tailed (power-law) models over data ranges up to four orders of magnitude. Scaling exponents quantifying ratios of frequent short to rare very long waits are species-specific, being determined by traits such as foraging mode (active versus ambush predation), body size and prey preference. A stochastic–deterministic decision model reproduced the empirical waiting time scaling and species-specific exponents, indicating that apparently complex scaling can emerge from simple decisions. Results indicate temporal power-law scaling is a behavioural ‘rule of thumb’ that is tuned to species’ ecological traits, implying a common pattern may have naturally evolved that optimizes move–wait decisions in less predictable natural environments.     

Expression cloning of a cDNA encoding M1/69-J11d heat-stable antigens

The differentiation Ag identified by the mAb M1/69 and J11d (commonly referred to as heat-stable Ag) are found in structurally heterogeneous forms on the surfaces of many types of murine hemopoietic cells. The extinction of expression of these antigens is associated with thymocyte maturation and Ig class switching in B cells, as well as terminal differentiation of macrophages. A cDNA encoding the M1/69-J11d peptide was cloned from a hemopoietic progenitor cell line by immunoselection of COS cells transfected with expression libraries. The cloned cDNA is a copy of a gene that is transcribed in M1/69-J11d+ lymphoid, myeloid, and erythroid cells. This gene could be responsible for the expression of all forms of the M1/69-J11d Ag, although there are homologous genes that may encode some forms of the Ag that are specifically expressed in bone marrow. The cloned cDNA encodes a surprisingly small peptide, predicted to contain only 30 amino acids after removal of a signal sequence and displacement of the C-terminal region by the glycosyl-phosphatidylinositol group that anchors the peptide to the cell surface. Almost all of the mass of the M1/69-J11d Ag accumulates through extensive N- and O-linked glycosylation at multiple sites in the short peptide. These carbohydrates are likely to execute the functions of M1/69-J11d Ag, which could be specialized to each cell type as a consequence of differential glycosylation.     

Ligand-dependent differences in estrogen receptor beta-interacting proteins identified in lung adenocarcinoma cells corresponds to estrogenic responses

Background

A recent epidemiological study demonstrated a reduced risk of lung cancer mortality in breast cancer patients using antiestrogens. These and other data implicate a role for estrogens in lung cancer, particularly nonsmall cell lung cancer (NSCLC). Approximately 61% of human NSCLC tumors express nuclear estrogen receptor β (ERβ); however, the role of ERβ and estrogens in NSCLC is likely to be multifactorial. Here we tested the hypothesis that proteins interacting with ERβ in human lung adenocarcinoma cells that respond proliferatively to estradiol (E₂) are distinct from those in non-E₂-responsive cells.

Methods

FLAG affinity purification of FLAG-ERβ-interacting proteins was used to isolate ERβ-interacting proteins in whole cell extracts from E₂ proliferative H1793 and non-E₂-proliferative A549 lung adenocarcinoma cell lines. Following trypsin digestion, proteins were identified using liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS/MS). Proteomic data were analyzed using Ingenuity Pathway Analysis. Select results were confirmed by coimmunoprecipitation.

Results

LC-MS/MS identified 27 non-redundant ERβ-interacting proteins. ERβ-interacting proteins included hsp70, hsp60, vimentin, histones and calmodulin. Ingenuity Pathway Analysis of the ERβ-interacting proteins revealed differences in molecular and functional networks between H1793 and A549 lung adenocarcinoma cells. Coimmunoprecipitation experiments in these and other lung adenocarcinoma cells confirmed that ERβ and EGFR interact in a gender-dependent manner and in response to E₂ or EGF. BRCA1 interacted with ERβ in A549 cell lines and in human lung adenocarcinoma tumors, but not normal lung tissue.

Conclusion

Our results identify specific differences in ERβ-interacting proteins in lung adenocarcinoma cells corresponding to ligand-dependent differences in estrogenic responses.

     

Relationship of visceral adiposity to cardiovascular disease risk factors in black and white teens

Objective: We tested the hypothesis that visceral adiposity, compared with general adiposity, would explain more of the variance in cardiovascular disease (CVD) risk factors. Research Method and Procedures: Subjects were 464 adolescents (238 black and 205 girls). Adiposity measures included visceral adipose tissue (VAT; magnetic resonance imaging), percent body fat (%BF; DXA), BMI, and waist girth (anthropometry). CVD risk factors were fasting insulin, fibrinogen, total to high‐density lipoprotein‐cholesterol ratio, triglycerides (TGs), systolic blood pressure, and left ventricular mass indexed to height^2.7. Results: After adjustment for age, race, and sex, all adiposity indices explained significant proportions of the variance in all of the CVD risk factors; %BF tended to explain more variance than VAT. Regression models that included both %BF and VAT found that both indices explained independent proportions of the variance only for total to high‐density lipoprotein‐cholesterol ratio. For TGs, the model that included both %BF and VAT found that only VAT was significant. For systolic blood pressure and left ventricular mass indexed to height^2.7, anthropometric measures explained more of the variance than VAT and %BF. Discussion: The hypothesis that visceral adiposity would explain more variance in CVD risk than general adiposity was not supported in this relatively large sample of black and white adolescents. Only for TGs did it seem that VAT was more influential than %BF. Perhaps the deleterious effect of visceral adiposity becomes greater later in life as it increases in proportion to general adiposity.     

Human health risks of metals and metalloids in muscle tissue of Synodontis zambezensis Peters, 1852 from Flag Boshielo Dam,South Africa

Muscle tissue from 63 Synodontis zambezensis collected bimonthly in 2013 at Flag Boshielo Dam were analysed for metals and metalloids in a desktop human health risk assessment. The Hazard Quotient, based on a weekly meal of 67 g of fish muscle, exceeded the maximum acceptable level of one for lead, cobalt, cadmium, mercury, arsenic and selenium. The concentrations of these elements were higher in 2013 than those recorded in 2009 and 2012 in other fish species from Flag Boshielo Dam and these may pose a long-term health risk if consumed regularly by impoverished rural communities reliant on fish as a source of protein.     

Cholesterol-free phospholipid domains may be the membrane feature selected by N epsilon-dansyl-L-lysine and merocyanine 540

We have used N epsilon-dansyl-L-lysine as a fluorescent membrane probe, to study cells taken from tissues concerned with immune function. There is a striking similarity between the staining selectivity of this compound and that reported by others for merocyanine 540. Both compounds stain leukemic, human, peripheral leukocytes, an erythroleukemia line, and some mouse bone marrow cells, suggesting common selectivity for a membrane feature of hemopoietic cells. Both compounds fail to stain red blood cells, normal human leukocytes, mouse spleen and thymus cells. We have recently reported that dansyl-lysine apparently selects for cholesterol-free phospholipid domains in liposomes and now report similar selectivity for merocyanine 540 staining of liposomes.     

There are two gene sequences for human apolipoprotein CI (apo CI) on chromosome 19, one of which is 4 kb from the gene for apo E

A cDNA probe corresponding to the mRNA sequence for apolipoprotein E (apo E) was used to screen two independently-constructed human genomic libraries. Two recombinants (lambda E-2, and lambda E2-1), isolated using the apo E cDNA probe, also contain part or all of the apo CI gene. Hybridisation studies using both apo E and apo CI cDNA probes show that these two genes are in the same orientation and separated by 4 kb.     

Association of TERC and OBFC1 Haplotypes with Mean Leukocyte Telomere Length and Risk for Coronary Heart Disease

Objective

To replicate the associations of leukocyte telomere length (LTL) with variants at four loci and to investigate their associations with coronary heart disease (CHD) and type II diabetes (T2D), in order to examine possible causal effects of telomere maintenance machinery on disease aetiology.

Methods

Four SNPs at three loci BICD1 (rs2630578 GγC), 18q12.2 (rs2162440 GγT), and OBFC1 (rs10786775 CγG, rs11591710 AγC) were genotyped in four studies comprised of 2353 subjects out of which 1148 had CHD and 566 T2D. Three SNPs (rs12696304 CγG, rs10936601G>T and rs16847897 GγC) at the TERC locus were genotyped in these four studies, in addition to an offspring study of 765 healthy students. For all samples, LTL had been measured using a real-time PCR-based method.

Results

Only one SNP was associated with a significant effect on LTL, with the minor allele G of OBFC1 rs10786775 SNP being associated with longer LTL (β=0.029, P=0.04). No SNPs were significantly associated with CHD or T2D. For OBFC1 the haplotype carrying both rare alleles (rs10786775G and rs11591710C, haplotype frequency 0.089) was associated with lower CHD prevalence (OR: 0.77; 95% CI: 0.61–0.97; P= 0.03). The TERC haplotype GTC (rs12696304G, rs10936601T and rs16847897C, haplotype frequency 0.210) was associated with lower risk for both CHD (OR: 0.86; 95% CI: 0.75-0.99; P=0.04) and T2D (OR: 0.74; 95% CI: 0.61–0.91; P= 0.004), with no effect on LTL. Only the last association remained after adjusting for multiple testing.

Conclusion

Of reported associations, only that between the OBFC1 rs10786775 SNP and LTL was confirmed, although our study has a limited power to detect modest effects. A 2-SNP OBFC1 haplotype was associated with higher risk of CHD, and a 3-SNP TERC haplotype was associated with both higher risk of CHD and T2D. Further work is required to confirm these results and explore the mechanisms of these effects.