BACKGROUND Given the lack of consensus about the effect of traffic-derived pollutants on male fertility, we evaluated semen quality in men occupationally exposed to traffic. METHODS Semen quality was investigated in 85 men employed at motorway tollgates and in 85 age-matched men living in the same area. Semen, circulating sex hormones, methaemoglobin, sulphaemoglobin, carboxyhaemoglobin, lead...

Haem (iron protoporphyrin IX) is both an essential growth factor and virulence regulator for the periodontal pathogen Porphyromonas gingivalis, which acquires it mainly from haemoglobin via the sequential actions of the R- and K-specific gingipain proteases. The haem-binding lipoprotein haemophore HmuY and its cognate receptor HmuR of P. gingivalis, are responsible for capture and internalisati...

Haemoglobin initiates free radical chemistry. In particular, the interactions of peroxides with the ferric (met) species of haemoglobin generate two strong oxidants: ferryl iron and a protein-bound free radical. We have studied the endogenous defences to this reactive chemistry in a rabbit model following 20% exchange transfusion with cell-free haemoglobin stabilized in tetrameric form [via cro...

Case. A 45-year-old man with a blank medical history presented at the emergency room with dizziness and cyanosis. Physical examination showed cyanosis with a peripheral saturation (SpO(2)) of 85%, he did not respond to supplemental oxygen. Arterial blood gas analysis showed a striking chocolate brown colour. Based on these data, we determined the arterial methaemoglobin concentration. This was ...

Lipid peroxidation and haemoglobin degradation were the two extremes of a spectrum of oxidative damage in red cells exposed to t-butyl hydroperoxide. The exact position in this spectrum depended on the availability of glucose and the ligand state of haemoglobin. In red cells containing oxy- or carbonmono-oxy-haemoglobin, hexose monophosphate-shunt activity was mainly responsible for metabolism ...

1. Erythrocytes (RBC) from control and marginally riboflavin-deficient subjects were fractionated into nine fractions using a discrete density gradient. 2. Glutathione reductase (NAD(P)H: glutathione oxidoreductase; EC 1.6.4.2) activity and aspartate aminotransferase (EC 2.6.1.1) activity (with and without the appropriate co-enzymes) reduced glutathione, methaemoglobin, sulphaemoglobin and oxy...