The importance of insect sperm: Sperm ultrastructure of Hermetia illucens (black soldier fly).

Sperm structure and ultrastructure of Hermetia illucens was determined by light microscopy and transmission electron microscopy. The main sperm components were similar as for other Dipteran subspecies, while the ultrastructure revealed distinguishing features in the zone of overlap and anterior flagellar region. Sperm varied in size indicating sperm polymorphism. The head region is lacking an acrosome. The zone of overlap consisted of uniquely organized centriolar adjunct material, partly forming electron dense areas to finally form an outer ring separating the mitochondrial derivatives from the 9 + 9 + 2 axoneme. Accessory bodies arising from the zone of overlap are flanked by smaller to large mitochondrial derivatives into the anterior flagellum. This study confirms sperm structure diversity between brachyceran subspecies and support its relationship with nematoceran subspecies.

CVD risk factors are related to plasma fibrin clot properties independent of total and or γ' fibrinogen concentration.

INTRODUCTION: Cardiovascular disease (CVD) risk factors are associated with total fibrinogen concentration and/or altered clot structure. It is however, unclear whether such associations with clot structure are ascribed to fibrinogen concentration or other independent mechanisms. We aimed to determine whether CVD risk factors associated with increased total and/or γ' fibrinogen concentration, were also associated with altered fibrin clot properties and secondly whether such associations were due to the fibrinogen concentration or through independent associations. MATERIALS AND METHODS: In a plasma setting CVD risk factors (including total and γ' fibrinogen concentration) were cross-sectionally analysed in 2010 apparently healthy black South African participants. Kinetics of clot formation (lag time, slope and maximum absorbance) as well as clot lysis times were calculated from turbidity curves. RESULTS: Of the measured CVD risk factors age, metabolic syndrome, C-reactive protein (CRP), high density lipoprotein (HDL)-cholesterol and homocysteine were significantly associated with altered fibrin clot properties after adjustment for total and or γ' fibrinogen concentration. Aging was associated with thicker fibres (p=0.004) while both metabolic syndrome and low HDL-cholesterol levels were associated with lower rates of lateral aggregation (slope), (p=0.0004 and p=0.0009), and the formation of thinner fibres (p=0.007 and p=0.0004). Elevated CRP was associated with increased rates of lateral aggregation (p=0.002) and consequently thicker fibres (p<0.0001). Hyperhomocysteinemia was associated with increased rates of lateral aggregation (p=0.0007) without affecting fibre thickness. CONCLUSION: Final clot structure may contribute to increased CVD risk in vivo through associations with other CVD risk factors independent from total or γ' fibrinogen concentration.

The effect of ethanol and its metabolism on fibrinolysis.

The role of ethanol metabolism in possible haemostatic cardioprotective effects has not yet been determined. To this end, we investigated the effect of a moderate dose of ethanol (35 g) and its metabolism, on haemostatic variables over 14 hours (h). Eighteen Caucasian males participated in a placebo-controlled, randomised, cross-over study. Blood was collected prior to alcohol consumption, and at 10 time points for 14 h. Blood ethanol peaked at 1 h and was cleared after 8 h following ethanol consumption, significantly increasing plasma acetate (p=0.0028). Ethanol did not influence the coagulation factors significantly. PAI-1act increased (p<0.0001) and tPAact (p=0.047) decreased following alcohol consumption, reaching maximum (0.69 to 22.2 IU/ml) and minimum (0.88 to 0.33 IU/ml) levels at 5 h, respectively. Significantly increased plasma clot lysis times (46.8 to 67.6 minutes) and reduced global fibrinolytic capacity of whole blood, measured as D-dimer production during incubation of blood clots (2.26 to 0.29 µg/ml), were found at 5 h. Except for PAI-1act (borderline significance; p=0.05), there was no significant difference in the fibrinolytic markers between the two groups the following morning. Moderate ethanol consumption resulted in a significant temporary fibrinolysis inhibition. Any protective effects of moderate ethanol consumption on cardiovascular disease do not appear to be due to improvement in fibrinolytic potential within the first 14 h following consumption. The use of global fibrinolytic assays is recommended for determining the true effect of ethanol on fibrinolysis.