The Effect In vitro of High-Density Lipoprotein from Healthy and Infected Humans on the Oxidative Metabolism of Polymorphonuclear Leukocytes

We studied the effects in vitro of high-density lipoprotein from healthy (N-HDL) and from infected humans (AP-HDL) on the oxidative metabolism of human polymorphonuclear leukocytes (PMN). Products of the H₂O₂–MPO–halide system were monitored by luminol-enhanced chemiluminescence and superoxide anion formation was monitored by lucigenin-enhanced chemiluminescence during stimulation of human PMN with phorbol myristate acetate (PMA) or an opsonized stimulus (OS). The results showed that N-HDL and AP-HDL affect the oxidative metabolism of PMN in different ways. The posible role of this effect is discussed. © 1997 John Wiley & Sons, Ltd.     

Behavioural notes on the Neotropical parasocial spider wasp Ageniella (Lissagenia) flavipennis (Banks) (Hymenoptera: Pompilidae), with host association

1. Ageniella is a species‐rich group of spider wasps restricted to the New World. Knowledge regarding the behaviour of this genus is based mainly on the Nearctic species, which have been reported to nest solitarily in the soil. This study reports for the first time the nesting behaviour, with host association of Ageniella (Lissagenia) flavipennis Banks. 2. Behavioural aspects on the nesting of A. flavipennis were observed from a study of six nests found in an Atlantic Forest conservation area in São Paulo State, Brazil. Host specimens were collected from a nest, as well as while being carried by an A. flavipennis individual. 3. The present study reports the A. flavipennis females cohabiting or nesting solitarily in mud nests, indicating that this spider wasp shows some lower level of parasociality. In addition, the spider Enoploctenus cyclothorax (Bertkau) was reported for the first time as host. As has been observed for other Ageniellini, females of A. flavipennis amputate the host's legs and transport the spider to the nest, flying or walking forward. 4. Communal behaviour has been reported for species of different genera of Pompilidae, such as Macromeris Lepeletier, Paragenia Bingham and Auplopus Spinola. Recent phylogenetic analyses suggest that the Lissagenia species are more closely related to the other Ageniellini genera than to the other Ageniella species. The present information on nesting and prey could contribute towards a more conclusive phylogenetic position of Lissagenia.     

Life history strategy of Leptinaria unilamellata (d'Orbigny, 1835) (Mollusca,Pulmonata, Subulinidae)

Abstract

Life history theory predicts that the patterns of resource allocation in animals are associated with different strategies, selected in the course of evolution. In the present study, the life history of Leptinaria unilamellata was characterized under laboratory conditions. We determined the growth, reproduction, and longevity patterns of this species and elucidated the strategy related to the development of embryos, through direct observations and examination of the morphology of the gravid uterus. Furthermore, we attempted to analyze the glycogen and galactogen contents of the albumen gland, digestive gland and cephalopedal mass in order to understand energy allocation to life history traits, for three life stages. Leptinaria unilamellata's life history is characterized by great longevity, a short juvenile phase, early sexual maturity, and repeated reproductive events, with little reproductive effort at each event and some mortality shortly after the first reproduction. In the terraria, we found juveniles but no eggs. However, the results of the anatomical study showed no morphological connection between the embryos and the parental organism. Thus, this species should be described as ovoviviparous rather than viviparous. Egg retention in the parent organism is the primary cause of the release of juveniles, instead of eggs, enabling the offspring to withstand environmental stress. The higher quantity of galactogen found in the adults' albumen gland, as compared to juveniles and senescent individuals, as well as the ratio of glycogen to galactogen, reveal the allocation of energy to reproduction rather than to growth. The remaining energy is directed to the maintenance of omeostasis. Such pattern was confirmed by the low levels of glycogen and galactogen observed in the senescent stage, compared to the juvenile and adult stages. In the life strategy of L. unilamellata, the distribution of the reproductive effort among many events associated with ovoviviparity indicates a long-term investment in reproductive success.     

Transmission of stridulatory signals of the burrower bugs, Scaptocoris castanea and Scaptocoris carvalhoi (Heteroptera: Cydnidae) through the soil and soybean

Abstract.  Males and females of the burrower bug species Scaptocoris castanea Perty and Scaptocoris carvalhoi Becker emit stridulatory signals when on the roots of soybean. The substrate-borne components of the signal can be recorded on the plant but not on the surrounding soil surface. The stridulatory apparatus is composed of the tergal plectrum (lima) and the stridulitrum (stridulatory vein) on the underside of the hind wings. The male plectrum has one ridge and the female lima has 13 ridges. Stridulitra of different species differ in the length and in the number of teeth. Rubbing of plectrum (lima) ridges over the stridulitrum in one or both directions produces pulse trains. The velocity of signals that are recorded less than 0.5 cm from the bug is below 0.013 mm s⁻¹ on the soil and below 0.066 mm s⁻¹ on the leaf surface. Broadband spectra have a dominant frequency of less than 1 kHz and subdominant peaks extending up to 7 kHz. The dominant frequency of the stridulatory signal transmitted through a plant decreases together with the proportion of its higher frequency spectral components. Signals are attenuated for 3–9 dB cm⁻¹ when transmitted through the soil or soybean leaf and for approximately 1 dB cm⁻¹ when transmitted through soybean stem.