Quantitative Bestimmung von RNS-Fraktionen im Gehirn frisch geschlüpfter Bienen (Apis mellifica)

Summary In the brain of the honeybee (Apis mellifica), it was found that the rRNA content decreases rapidly during the first 2 days of adult life. An increase is observed from days 3 to 5, followed by another decrease to a level inferior to that of day 2 to 3. Except for a rise on the 5th day, 4s RNA remains constant. An unidentified RNA fraction of low molecular weight (D) sharply decreases on day 5. The possibility is discussed that these results reflect changes in RNA metabolism that can be related to the sequences of activity observed in the bees during the first 9 days after hatching.     

An antibody to low density lipoprotein in diabetics

Summary The serum of 21/180 unselected diabetics contains a low titre antibody to human low density lipoprotein. A similar antibody was found in 10/88 persons with tuberculosis.     

The use of cyclophosphamide as an enhancer of the vaccine against foot-and-mouth disease

The immunization of biungulate animals with killed foot-and-mouth disease virus (FMDV) requires periodic vaccinations due to a low vaccine immunogenicity. Therefore, FMDV antigens need to be combined with adjuvants such as aluminum hydroxide, saponin or oil emulsions. Animal handling for periodic inoculations, and the repeated doses of vaccines that have to be administered increase the commercialization costs. Moreover, the use of adjuvants may induce adverse effects.In the present work we show that it is possible to increase the life span of neutralizing antibodies in serum when a single dose of cyclophosphamide (Cy) is administered four days before vaccination with aluminum hydroxidesaponin FMDV vaccine.     

The alteration of juvenile hormone titre inSpodoptera litura (F.) due to a baculovirus infection

Summary The haemolymph juvenile hormone levels ofSpodoptera litura were remarkably low (540 Galleria units (GU)/ml) at the last larval moult as well as prior to pupation (194 GU/ml). During the last intermoult period this was 2600 GU/ml for a 24 h-period. On the other hand, the JH level in the haemolymph of NPV-infected last instar larvae was initially 1740 GU/ml but was maintained at 2400–2600 GU/ml during the next 48 h. Finally, the JH titre fell to 1393 GU/ml, but only prior to death. The failure of the diseased larvae to undergo the larval pupal moult is ascribed to the alteration of the JH titre in the haemolymph.     

Zum phototaktischen Laufverhalten junger Honigbienen (Apis mellifica L.)

Summary The number of phototactic runs towards low light intensities of young bees (Apis mellifica L.) depends on their age. On the 1st day there is almost no response. After the 4th day a light intensity as low as 0.1 Lux induces a phototactic run. This increase of response coincides with the performance of the 1st exercise flight.     

Calorie restriction and the nutrient sensing signaling pathways

Calorie restriction (CR) is the most potent regimen known to extend the life span in multiple species. CR has also been shown to ameliorate several age-associated disorders in mammals and perhaps humans. CR induces diverse metabolic changes in organisms, and it is currently unclear whether and how these metabolic changes lead to life span extension. Recent studies in model systems have provided insight into the molecular mechanisms by which CR extends life span. In this review, we summarize and provide recent updates on multiple nutrient signaling pathways that have been connected to CR and longevity regulation. The roles of highly conserved longevity regulators – the Sirtuin family – in CR are also discussed. Received 25 August 2006; received after revision 9 October 2006; accepted 13 December 2006     

Der Einfluß der Temperatur auf die Giftwirkung des DDT bei Honigbienen (Apis mellifica L.)

Summary The action of DDT on honey-bees depends to a high extent on the temperature (see graph). At 36°C (breeding temperature) DDT has a far weaker insecticidal action than at 20°C (laboratory temperature). This shows that the insecticidal properties of DDT diminish with the raise of temperature.This resistance to DDT at higher temperature is most propitious for bee-keeping and also explains the fact why in agricultural practice there has been no corroborated case of poisoning of bees, though in laboratory tests DDT avered itself to be toxic to bees.     

Pollen-collecting by stingless bees on cacao flowers

Summary Stingless bees (Trigona jaty) routinely visit the flowers ofTheobroma cacao (Sterculiaceae) in the Atlantic lowlands of Costa Rica. The bees collect pollen and behave as pollen thieves in flowers well exposed to direct sunlight in cacao plantations, and avoid flowers in heavy shade. Pollination rates are maximized, however, in heavy shade due to the high abundance of the small-bodied pollinating midges (Ceratopogonidae and Cecidomyiidae) found in such places. Pollen-thieving by stingless bees, therefore, may only impact on fruit set in cacao trees in direct sunlight, with only minimal to no impact in areas of cacao where natural pollinator activity is high.This research was funded by grants from The American Cocoa Research Institute of the United States of America. I thank T. Noeske for statistical assistance.     

Ruminations on dietary restriction and aging

Calorie restriction has been known for many decades to extend the life span of rodents. Since the more recent discovery that a long-term reduction in nutrient intake also extends life span in nearly every invertebrate model organism used for aging research, the mechanisms behind the longevity benefits of this intervention have been under intense scrutiny. While models have been developed in yeast, worms, and flies, the molecular mechanisms governing life span extension by calorie restriction remain controversial, resulting in great anticipation of mammalian studies testing these models. Here we discuss the links between nutrient reduction and enhanced longevity with emphasis on evolutionarily conserved nutrient response signaling. Received 1 November 2006; received after revision 15 December 2006; accepted 27 February 2007     

Influence of adult food on the reproduction of virgin females of anAcanthoscelides obtectus strain originating from Colombian altiplanos

Summary The reproductive activity of virgin females of anAcanthoscelides obtectus strain originating from the high Colombian plateau was variable. Some females did not synthesize vitellogenin during imaginal life while others produced mature oocytes. In the case of virgin females without reproductive activity, the supply of pollen in the adult diet did not stimulate synthesis and incorporation of vitellogenin. On the other hand, the supply of pollen always induced a higher vitellogenin titre in the haemolymph of females which produced oocytes, and stimulated ovarian production.     

Juvenile hormone titre and regulation in the cockroach Diploptera punctata

Titres of juvenile hormone (JH) have been determined in both hemolymph and whole body extracts of female Diploptera punctata during the first gonotrophic cycle using a method employing gas chromatography/mass spectrometry for qualitative and quantitative analysis. JH III is the sole JH found in both adult and last instar D. punctata. Maximum values of approximately 1500 ng/ml (approximately 6 microM) were observed at the middle of the gonotrophic cycle, when basal oocyte growth rate was greatest. Changes in rates of JH release in vitro by corpora allata paralleled closely the changes in JH titre, suggesting that biosynthesis is a major regulator of titre. JH levels per animal were calculated from observed JH titres, and at certain time points in the gonotrophic cycle JH obtained from analysis of whole bodies were significantly greater than those predicted from hemolymph titres. These results suggest the existence of a nonhemolymph JH pool in D. punctata. Decay in JH titre after allatectomy of 5 day females has also been studied. Following a rapid initial decline, the rate of decay slowed appreciably 4 h post-operation. Thus, use of a first-order rate constant to estimate half-life of JH significantly underestimated the longevity of the hormone. The apparent persistence of JH following allatectomy may be due to the existence of a nonhemolymph JH pool.     

A possible age-related decrement in the conduction velocity of Aplysia neuron R2.

In late winter and in spring, the conduction velocity of the R2 axon of Aplysia californica is 0.48 m/sec or more in all specimens. However, in the summer, fall and early winter, some sexually mature animals exhibit markedly diminished R2 conduction rates (as low as 0.24 m/sec). It is possible that this reduced velocity is a reflection of the age of the specimen from which the axon is taken.     

Changes of hormonal status in young mice by restricted caloric diet. Relation to lifespan extension. Preliminary results

Summary The maintainance of mice on a reduced caloric diet for 6 weeks starting from weaning time produces persistent changes in their hormonal status as reflected by differences in blood levels of gonadal and adrenal steroids. The changes might express a permanently different hypothalamic regulation. This might accoutn for a prolongation of their life span.This work has been supported by the Swiss National Fund for Scientific Research, grant No. 3.8750.72. I thank Miss M. Hämmerli of Ciba-Geigy AG, Basel, for her participation in the low caloric diet experiments.     

Mitochondrial DNA evidence for the 19th century introduction of African honey bees into the United States

Since the introduction of an African subspecies into Brazil in the mid-1950's¹, descendent Africanized honey bees (Apis mellifera L.) have spread throughout the Neotropics and into temperate North America. Restriction enzyme analysis of 422 feral honey bee colonies collected from non-Africanized areas in the southern United States revealed that over 21% of them had mitochondrial DNA (mtDNA) derived from a European race established in North America by the 17th century, 77% of them had mtDNA common in honey bees maintained by beekeepers and about 1% exhibited African mtDNA. Further analysis revealed that the African mtDNA was derived from a north African subspecies imported to the US in the 19th century.     

Intergenerational programming of metabolic disease: evidence from human populations and experimental animal models

We are in the midst of unparalleled epidemics of obesity and type 2 diabetes—complex phenotypes originating at the intersection of genetic and environmental risk. As detailed in other chapters, evidence indicates that non-genetic, or environmental, risk may initiate during prenatal and early postnatal life [1]. Striking examples in humans include the association of low birth weight (LBW) and/or accelerated early growth with increased risk of insulin resistance, obesity, type 2 diabetes (T2DM), and cardiovascular disease (CVD), and the close relationship between maternal obesity or diabetes with childhood obesity. In this chapter, we will focus on the intriguing emerging data from both human and animal models that indicate that intrauterine and childhood exposures can also influence risk for diabetes and cardiovascular disease in subsequent generations. Understanding the mechanisms responsible for these effects is critical in order to develop effective metabolic and nutritional interventions to interrupt such vicious intergenerational cycles potentiating risk for metabolic disorders.     

Treatment of spontaneous murine lymphomas with syngeneic lymphoid cells

Syngeneic thymus grafts and spleen cells were administered to thymectomized and intact (C57BL/1XA)F1 mice with spontaneous lymphomas. Their life span was prolonged significantly compared to untreated tumor-bearing controls. Dramatic clinical and histologic evidence of tumor regression was observed.     

T-Lymphocyte regulation of contact sensitivity: effect of thymectomy in adult mice]

6 weeks after adult thymectomy (ATx) in the Mouse, the contact sensitivity reaction to dinitrofluorobenzene (DNFB) is enhanced. 4 to 7 months after ATx, this reaction is deeply, but incompletely depressed, whereas the concomitant antibody response is not affected. These results suggest that both a suppressor, and an amplifier, T lymphocytes, the life span of which is different after ATx, are involved in the regulation of contact sensitivity. The effect of circulating thymic factor on this reaction suggests that this factor acts exclusively, at least in short treatments, on the suppressor function.     

Complexed rheumatoid factor measurements in sera, synovial fluids and in immune complex fractions.

Mild acidic treatment increases the rheumatoid factor titre of some sera and synovial fluids (SF) in rheumatoid arthritis (RA), juvenile RA (JRA) and most frequently in rheumatoid vasculitis. This unmasking of 'hidden' RF in serum and SF samples correlated with the RF-immune complexes (RF-IC) and complexed C4 present in the 3% polyethylene glycol (PEG) precipitates, indicating that by means of 'hidden' RF measurements RF-ICs are possibly detected. This method seems to provide a diagnostic tool for detecting RF-ICs in RA and other related diseases.     

Heat production by balling in the Japanese honeybee,Apis cerana japonica as a defensive behavior against the hornet,Vespa simillima xanthoptera (Hymenoptera: Vespidae)

Summary As an effective counterattack strategy against predacious hornets, especiallyVespa simillima xanthoptera, workers ofApis cerana japonica showed a distinct balling reaction, usually involving 180–300 bees. This produced heat for as long as 20 min, giving rise to temperatures inside the ball higher than 46°C, which is lethal to the hornet but not to the bees.