Oxidation of cholesterol moiety of low density lipoprotein in the presence of human endothelial cells or Cu+2 ions: identification of major products and their effects

Oxidation of lipoproteins is believed to play a key role in atherogenesis. In this study, low density lipoproteins (LDL) was subjected to oxidation in the presence of either human umbilical vein endothelial cells or with Cu+2 ions and the major oxides formed were identified. While cholesterol-alpha-epoxide (C-alpha EP) was the major product of cholesterol peroxidation in the presence of endothelial cells, cholest-3,5-dien-7-one (CD) predominated in the presence of Cu+2 ion. Both steroids were identified by gas chromatography/mass spectrometry. HDL cholesterol was resistant to oxidation. When tested on human skin fibroblasts in culture C-alpha EP (10 micrograms/ml) caused marked stimulation of 14C-oleate incorporation into cholesterol esters, while CD stimulated cholesterol esterification only mildly. These studies show that a) C-alpha EP is the major peroxidation product of LDL cholesterol moiety in the presence of endothelial cells and b) it causes marked stimulation of cholesterol esterification in cells. C-alpha EP may play a key role in increasing cholesterol esterification noted in atherogenesis.

Stable isotope analysis of termite food habits in East African grasslands

Stable carbon isotope techniques were employed to study the food habits of the termite Macrotermes michaelseni (Isoptera: Termitidae) in a semiarid savanna habitat in Kenya. At Kajiado this species utilized approximately 70% herbaceous vegetation (mostly grass) and 30% woody vegetation, while at Ruiru approximately 64% of the vegetation utilized was woody and 36% herbaceous. Stabel carbon isotope ratios varied between castes within sites, but were consistent with the manner in which carbon flows through termite colonies. δ(13)C values increased in the sequence: diet→fungus comb→nonreproductive castes→reproductive castes. These results are in agreement with the idea that organic carbon becomes enriched in (13)C as it passes through a food chain.

Plasma lipoprotein peroxidation potential: a test to evaluate individual susceptibility to peroxidation

Peroxidation of lipids is believed to play a key role in various degenerative diseases. However, few simple tests are able to detect individual susceptibility or resistance to peroxidation. Measurement of the basal concentrations of lipid peroxides in plasma is not satisfactory because they are so low. Therefore, we developed a test to determine susceptibility of whole plasma to metal/H2O2-catalyzed peroxidation. Incubation of 300-500 microL of plasma with H2O2/cupric acetate resulted in the formation of products from fatty acids (malonaldehyde, measured by thiobarbituric acid assay) and cholesterol (predominantly cholest-3,5-dien-7-one, measured by gas-liquid chromatography). In the presence of Cu2+, formation of malonaldehyde and cholest-3,5-dien-7-one increased at least 10-fold over basal values. Lipid peroxide (malonaldehyde) and cholesterol oxide concentrations after peroxidation were significantly higher (P less than 0.01) in diabetic plasma than in normal plasma. Because susceptibility to plasma peroxidation represents a balance between pro-oxidant factors and antioxidant protection, this test may be useful in determining individual susceptibility to peroxidation as influenced by nutritional and clinical status.

Acute liver failure

Acute liver failure is a rare syndrome and is primarily caused by paracetamol toxicity in developed nations. Survival for patients with acute liver failure has steadily improved over the last few decades from approximately 20% to greater than 60%. This marked improvement in survival has been due to a combination of improvements in medical practice and the use of emergency liver transplantation in selected patients. Early recognition and timely initial management in the non-specialist centre can significantly improve outcomes. Patients should be simultaneously discussed with a transplant centre and referred to critical care. Close liaison with transplant centres to ensure timely transfer in deteriorating patients is important.

Incidence of Gastrointestinal Bleeding After Transesophageal Echocardiography Use in Orthotopic Liver Transplantation

The risk of upper gastrointestinal bleeding (UGIB) after transesophageal echocardiography (TEE) in patients with high grade esophageal varices (EV) that are undergoing Orthotopic Liver transplantation (OLT) is poorly understood. This was a retrospective single-centre cohort study in all patients that underwent OLT at Queen Elizabeth Hospital Birmingham between September 2016 and September 2018. The primary outcome was to determine the incidence of UGIB in patients that have undergone OLT with EV that received TEE. 401 patients were included in the study, of which 320 (80%) received TEE. The incidence of post-operative UGIB in patients that received TEE was 1.6% (5/320) in the entire cohort: 2.7% (4/149) in patients with no evidence of EV and 0.6% (1/171) in patients with EV. UGIB occurred in 1 patient with grade 2 EV and did not occur in patients with grade 1 or 3 EV. The incidence of UGIB in patients that received TEE was not statistically different to patients that did not: 1.6% (5/320) vs. 3.7% (3/81) p = 0.218. In conclusion, in patients that underwent OLT, intra-operative TEE use was associated with low rates of UGIB, even in cohorts with high grade EV. This suggests that TEE is a relatively safe method of haemodynamic monitoring in patients undergoing OLT.

Plasma lipoprotein peroxidation potential: a test to evaluate individual susceptibility to peroxidation

Peroxidation of lipids is believed to play a key role in various degenerative diseases. However, few simple tests are able to detect individual susceptibility or resistance to peroxidation. Measurement of the basal concentrations of lipid peroxides in plasma is not satisfactory because they are so low. Therefore, we developed a test to determine susceptibility of whole plasma to metal/H2O2-catalyzed peroxidation. Incubation of 300-500 microL of plasma with H2O2/cupric acetate resulted in the formation of products from fatty acids (malonaldehyde, measured by thiobarbituric acid assay) and cholesterol (predominantly cholest-3,5-dien-7-one, measured by gas-liquid chromatography). In the presence of Cu2+, formation of malonaldehyde and cholest-3,5-dien-7-one increased at least 10-fold over basal values. Lipid peroxide (malonaldehyde) and cholesterol oxide concentrations after peroxidation were significantly higher (P less than 0.01) in diabetic plasma than in normal plasma. Because susceptibility to plasma peroxidation represents a balance between pro-oxidant factors and antioxidant protection, this test may be useful in determining individual susceptibility to peroxidation as influenced by nutritional and clinical status.

Saphenous vein graft aneurysm fistula formation causing right heart failure: an unusual presentation

Saphenous vein graft aneurysm (SVG) formation after coronary artery bypass grafting is a rare complication of the surgery. We present a case of a 68-year-old man with an unusual presentation of such an aneurysm. Thirty-four years after his initial bypass surgery, the patient presented with a fistula formation into his right atrium from a vein graft aneurysm. Late aneurysm formation is thought to occur secondary to atherosclerotic degeneration of the SVG with background hypertension and dyslipidaemia accelerating the process. Diagnostic modalities used to investigate SVG aneurysms include computed tomography, transthoracic echocardiogram, magnetic resonance imaging and cardiac catheterisation. Aneurysms with fistula formation historically require aggressive surgical intervention. Resection of the aneurysm with subsequent revascularisation if required is the surgical norm. SVG aneurysm with fistula formation into a cardiac chamber is a rare complication of coronary artery bypass grafting (CABG), which can occur with atypical presenting symptoms. Physicians should keep in mind the possibility of this occurring in post-CABG patients presenting with heart failure and a new murmur.

Organoleptic characteristics and compositional profile of meat of growing Japanese quail fed different levels of poultry byproducts compost

The poultry industry generates a lot of waste, including dead birds, manure, and poultry litter. Poultry waste should never be disposed of improperly because it can seriously harm the environment. The waste can be recycled as a feedstock for use in poultry feed by composting the litter and deceased birds. The compositional profile and organoleptic properties of the meat of growing Japanese quail were examined over the course of a 4-week trial to ascertain the effect of adding compost to the diet. In a completely randomized design (CRD), 1200 newly hatched quail chicks (Coturnix coturnix japonica) were divided into five treatment groups (diets with 0, 2.5, 5, 7.5, and 10% compost), each consisting of 40 birds with six replicates. The addition of compost to the diet had no noticeable effects on the organoleptic qualities of appearance, color, aroma, taste, texture, juiciness, tenderness, and acceptability (P>0.05). The compositional profile characteristics for chicks given compost at any level compared to chicks fed the control diet showed no differences (P>0.05). These findings suggest that the sensory characteristics and compositional profile of growing meat quails can be maintained when fed diets including up to 10% compost.

Assessing effect of feeding poultry byproducts compost on organoleptic characteristics and compositional profile of meat of broiler chickens

Large amounts of waste, including dead birds, manure, and poultry litter, are produced by the poultry industry. Poultry waste should be disposed of properly to avoid major pollution and health risks. Composting litter and dead birds could be an option to recycle the waste and use in poultry feed. A study was conducted to investigate the effects of feeding composted poultry waste on the organoleptic qualities and compositional profile of the meat of broiler chickens. A total of 300 day-old broiler chicks (500-Cobb) were randomly allocated to five treatment groups replicated six times with 10 birds each, under a completely randomized design (CRD). Five iso-caloric and iso-nitrogenous diets including composted poultry byproducts at concentrations of 0, 2.5, 5, 7.5, and 10% were fed ad libitum to the birds from day 0 to day 35. The sensory grading and meat composition profile of 500 Cobb broiler chickens were tested at 35 days of age. The findings showed that there were no variations in the sensory profiles of the meat from birds given various diets (P>0.05). Although the results were somewhat lower for the chicks fed compost-containing diets than for the control group, this difference was deemed to be insignificant (P>0.05). Similarly, there were no variations in the compositional profile values of the meat between meat from birds fed various diets (P>0.05). These findings imply that broiler chickens may be raised on diets containing up to 10% poultry byproduct compost without any negative impacts on the meat's sensory quality or composition. Additionally, using compost into broiler diets may help to lower the cost of feed.