Electroantennogram responses of synthetic periplanone-A and periplanone-B in the american cockroach
The electroantennogram responses of synthetic (−)-periplanone-B (PB) and (−)-periplanone-A (PA) were evaluated by using the antennae of the unmated male American cockroachPeriplaneta americana L. The threshold concentrations of the pheromone activities for the two chemicals were similar. Neither a synergistic nor an inhibitory response was noted, and only an additive effect was detected when PA and PB were applied as a mixture.
Behavioural responses to female sex pheromone components in Periplaneta americana

Female American cockroaches, Periplaneta americana, release two sex pheromones, periplanone-A and periplanone-B, each of which is perceived by a specialized receptor type on the male antennae. This study investigates whether male behavioural responses to both components may differ qualitatively or quantitatively. Running, upwind orientation and wing-raising were evoked by stimulation with either component. The intensity of running increased with stimulus concentration in much the same way for both substances. However, the relative effectiveness of periplanone-A was 30 times lower in behavioural assays than in the electroantennogram. Behavioural responses to periplanone-B declined faster and were more easily adapted by repeated stimulation than those to periplanone-A. It is hypothesized that periplanone-B is responsible for long distance attraction while periplanone-A influences male behaviour near the female.
Axonal sensorimotor neuropathy in patients with β-thalassaemia
Objective: The purpose of this study was to investigate the prevalence of peripheral neuropathy in patients with β-thalassaemia. Methods: Thirty six patients with a mean age of 29.2±8.2 years and 17 healthy controls with a mean age of 27.6±9.1 were included in this study. Measurements included the neuropathy symptoms score (NSS), the neuropathy disability score (NDS) as well as nerve conduction studies of two motor (ulnar and peroneal) and two sensory (ulnar and sural) nerves of the right limbs. Results: A mainly sensory axonal polyneuropathy was present in 19 out of 36 patients (52.7%). Eight out of these 19 patients also had abnormal NDS values. The neuropathy correlated significantly with the age of the patients and the hematocrit. However, it did not correlate with the presence of antibodies against HCV, the ferritin levels, or with a history of transfusions, desferrioxamine treatment, or splenectomy. Conclusions: This study showed a high prevalence of a predominantly sensory neuropathy in patients with β-thalassaemia. The electrophysiological data suggest that the underlying pathology is an axonopathy. Chronic hypoxia of the nerves resulting from severe anaemia may contribute to the pathogenesis of this neuropathy.