Morphology of the carnation-light synthetic lethal focus in Drosophila melanogaster

A histological study of the carnation-light lethal focus revealed morphological abnormalities in brain tissue. The ratio of core width to total brain width and brain texture consistently differed between lethal (car-lt) and their non-lethal sibs.     

Infecundity and dominant lethal mutations induced inMusca domestica L. by sodium azide (NaN3)

Summary Results of our study suggest that sodium azide is effective in the induction of sterility and dominant lethal mutations in both sexes ofM. domestica L. When treated males were crossed with nontreated females, 100% dominant lethal mutations and 72.3% infecundity were found, whereas in the crosses of nontreated males and treated females, 82.5% dominant lethal mutations and 33.1% infecundity were found. This showed that males are more sensitive to sodium azide than females.     

Molecular targets of glioma invasion

Glioblastoma multiforme is the most common and lethal primary malignant brain tumor. Although considerable progress has been made in technical proficiencies of surgical and radiation treatment for brain tumor patients, the impact of these advances on clinical outcome has been disappointing, with median survival time not exceeding 15 months. Over the last 30 years, no significant increase in survival of patients suffering from this disease has been achieved. A fundamental source of the management challenge presented in glioma patients is the insidious propensity of tumor invasion into distant brain tissue. Invasive tumor cells escape surgical removal and geographically dodge lethal radiation exposure and chemotherapy. Recent improved understanding of biochemical and molecular determinants of glioma cell invasion provide valuable insight into the underlying biological features of the disease, as well as illuminating possible new therapeutic targets. These findings are moving forward to translational research and clinical trials as novel antiglioma therapies. Received 25 July 2006; received after revision 27 October 2006; accepted 22 November 2006     

Rana esculenta complex: An experimental analysis of lethality and hybridogenesis

Summary Experiments designed to analyze the lethality and hybridogenesis in the European green frog complex have yielded the following results: 1. As a rule the inter-se cross ofRana esculenta is lethal, but several crosses have produced fully viable progeny. The frequency of such break-through crosses appears to be related to parental population structure. 2. Parabiotic joining of lethal to viable embryos indicates that manifestation of the lethal effect is autonomous. There is, however, a 16–18% increase in the life span of the lethal partner. 3. Studies of LDH isozyme patterns revealed that thelessonae-specific alleles coding for the B^a and B^c subunits can be passed to the F₁ progeny from a parental female or male of theesculenta phenotype. This demonstrates that there is no total elimination of thelessonae genome in theesculenta germ cells. 4. Immunologically, offspring from the inter-se cross ofR. esculenta show a closer relationship to theridibunda than to theesculenta phenotype. Variations of antigenic protein patterns suggest the possibility of chromosomal recombination betweenlessonae andridibunda in theesculenta hybrid. These results are confirmed by two-dimensional electrophoretic analysis of proteins in the oocytes of the three frog phenotypes.This work was supported by grants from the Swiss National Science Foundation and the Georges and Antoine Claraz Schenkung.     

Analyse expérimentale de l'expression de la mutation léthale récessive («ulcère») chez l'embryon dePleurodeles waltlii (Amphibien Urodèle)

Summary The autonomous expression of a recessive lethal mutation (ulcèreu), isolated in the salamanderPleurodeles waltlii Michah. is demonstrated by the way of parabiotic and telobiotic associations, allogenic chimaeras, heterotopic grafts of organ primordia and of anterior or posterior parts from lethal embryos.     

Type III (Arthus) allergic reactions and endotoxin toxicity in guinea-pigs

Summary Lipopolysaccharide (endotoxin) fromE. coli cells produced lethal effects in guinea-pigs. Endotoxin caused no visible dermal change in normal animals, but produced skin reactions characterized by specific Arthus-type (Type III immune hypersensitivity) vascular inflammation in immunized animals. It is concluded that Arthus allergic reactions were evoked by endotoxin, however, endotoxin lethal toxicity appears independent of this process.Acknowledgment. Supported by a grant from the National Health and Medical Research Council of Australia.     

Sur les effets du 5-fluoruracile injecté à l'embryon de Poulet à des stades avancés de l'incubation

Summary 5-FU, injected into the chick embryo on the 5th and the 8th day of incubation, has an immediate lethal effect and a later lethal effect which are very attenuated. On the other hand, when injected in very high doses, the substance has a uniform teratogenic action and causes malformations which attain specifically the members, the brain, and the beak.

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Ces recherches ont été faites grâce à un subside du Fonds National Suisse de la recherche scientifique et de la Fondation E. Barell.     

Synergistic effect of rabbit specific antiserum and amikacin on the treatment of mice with lethal infection due toKlebsiella pneumoniae

Summary A combination of rabbit specific antiserum and amikacin showed a synergistic effect on the treatment of mice with lethal infections due to a strain ofKlebsiella pneumoniae.     

Antihepatoxic constituents ofGarcinia kola seeds

Summary Kolaviron, a fraction of defatted methanolic extract and biflavanones ofGarcinia kola seeds significantly antagonized the lethal poisoning of mice with phalloidin. Garcinia biflavanones GB1, GB2 and kolaflavanone were isolated as the active constituents.     

Étude sur le choc produit par le polysaccharide du bacille du colon chez le rat porteur de tumeur (Note préliminaire)

Summary Aged preparations of polysaccharide fromE. coli were highly effective in inducing a lethal shock in rats bearing a tumor. This effect may be increased by some medications, while various steroid hormones afforded an efficient protection.     

Dealing with active oxygen intermediates: A halophilic perspective

Although oxygen tensions in the halophilic environment are diminished, they are nevertheless sufficient for the generation of active oxygen intermediates as byproducts of metabolism. Therefore, like all other aerobes, halophilic bacteria are compelled to possess the means to detoxify potentially lethal active oxygen intermediates. This review examines the superoxide, hydrogen peroxide, hydroxyl radical and singlet oxygen scavenging capacity of the halophiles,Halobacterium spp. Specifically, it looks at the potential of the bacteria to generate active oxygen intermediates and then examines the roles of superoxide dismutase, catalase, peroxidase and catalase-peroxidase. It also looks at some non-enzymatic means of neutralizing potentially lethal active oxygen intermediates.     

Etude comparative des besoins minima en oxygène chez différentes espèces de Téléostéens

Summary The lowest levels of oxygen tension tolerated by 3 Teleost fishes were determined.Aequidens latifrons is able to survive at very low O₂ tensions which are lethal for the other species. This particularity can be correlated with ecological and physiological characters of this species.     

An unusual case of a complex heterozygote presenting no taxonomical problem inChelidonium majus L. (Papaveraceae)

Summary Chelidonium majus shows a closed ring of 12 chromosomes at meiosis. The maintenance of this translocation heterozygosity is assured by a balanced combination of lethal alleles. The fertility is estimated to be 60–70%. In spite of its genetic system and its wide distribution, the genus is monospecific.     

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.     

Effect of ethanol and isopropanol on the activity of alcohol dehydrogenase,viability and life-span inDrosophila melanogaster andDrosophila funebris

Summary The effects caused by the addition of 2 alcohols to the culture medium of 2 species ofDrosophila, D. melanogaster andD. funebris, are compared. Ethanol at 1% concentration causes slight and tolerable changes in both species. 1% isopropanol is lethal in 1 species and causes drastic changes in the other.The author acknowledge Dr A. Prevost for continuous support and E. Juan and Ll. Serra for their helpful suggestions.     

Antimitotic effect of nimbidin — A first report

Summary The antimitotic activity of nimbidin, a drug from the plantMelia azadirecta indica, was assessed by its effect on the meristematic cells of onion root tips. The effect was almost similar to those of colchicine and vinca alkaloids. Recovery trials showed that the drug induces lethal damage in a considerable proportion of treated cells and may hence have applications in cancer chemotherapy.     

Intraspezifische Unterschiede der relativen Hirngrösse beim Löwen (Panthera leo L.)

Summary Different stages of brain evolution expressed by the allometric relation of³ brain capacity and basal length of the skull are shown to be existent in the speciesPanthera leo. Whereas Asiatic lions obviously have the same level of brain size as leopards (Panthera pardus), African lions have higher brain capacities. A third level seems to be represented by the upper pleistocene American lion,Panthera leo atrox. These results permit us to reject some conceptions ofHerre andRöhrs ¹³ concerning the quantitative expression of mammalian brain evolution.     

Low ambient oxygen tolerance in some freshwater teleosts

Summary Measurements of the asphyxial oxygen level forRhinomugil corsula, Tilapia mossambica, Puntius sarana andCarassius auratus at 30 and 35°C revealed that at 35°C the lethal oxygen level was higher forT. mossambica andP. sarana and lower forR. corsula, but it remained the same forC. auratus at 30 and 35°C. From a thesis (M.P.M.) approved for the degree of Doctor of Philosophy, Madurai Kamaraj University, madurai, India. We wish to express our thanks to Prof. S. Krishnaswamy for providing facilities and to Dr S.V. Job for suggestions.     

Einige Bemerkungen zur Form und zum Relief der Schädelausgüsse vonPithecanthropus und vonSinanthropus

Summary The general morphological and the fissural character ofDubois' andKoenigswalds Pithecanthropi andBlack's Sinanthropus (E) strongly suggest that thePithecanthropus brain had more anthropoid features than theSinanthropus brain.     

Niche width of parasites in species-rich and species-poor communities

Summary Niche width of ectoparasites of marine fishes, as measured by host range and microhabitat width, is not affected by the number of species in a community. There is no reduction in species numbers of Monogenea due to greater numbers of other parasite species, and frequencies of infection with Monogenea are greater in tropical, species-rich communities.Supported by grants from the Australian Research Grants Committee and the University of New England. M. Heap provided valuable technical assistance, and F. Roubal made his data onAcanthopagrus australis available to me.