Development and characterization of a human cell line from an ovarian mixed mullerian tumor (carcinosarcoma)

Summary A cell line derived from a human ovarian carcinosarcoma was established in tissue culture and in nude mice. Two sublines, LDF and HDF, separated by discontinuous density centrifugation were also established from the parent line JoN. The cloning efficiency of the JoN line was 21%. Morphologic features of adenocarcinoma cells characteristic of the parent JoN cells were retained in the sublines and clones; all lines showed the same karyotype and DNA content (pseudodiploid and pseudotetraploid). Keratin, as demonstrated immunohistochemically, was strongly expressed in the parent line JoN and the xenograft tumor, but not at all in the LDF sublines and only moderately in the HDF sublines. Vimentin, however, was expressed in neither the parent line JoN nor the xenograft tumor, but was present in both sublines. Transglutaminase and plasminogen activator activity was high in the parent line JoN. Neither, sublines nor clones showed the same high enzyme activity as the parent line. It is concluded that this human tumor line JoN is comprised of epithelial cells, capable of multidirectional differentiation.     

The energy cost of echolocation in pipistrelle bats (Pipistrettus pipistrellus)

Summary A positive relationship was established between energy expenditure and pulse rate of echolocation for 8 pipistrelle bats (Pipistrellus pipistrellus) when hanging at rest in a respirometry chamber at 28 °C. The least squares fit equation: Energy expenditure (J·^–1·h^–1)=110.09+ 40.3 pulse rate (n/s) explained 14% of the minute by minute variation in energy expenditure. For a 6 g bat therefore each pulse costs approximately 0.067 Joules to produce. The net cost of echolocation at 10 pulses per second for a 6 g pipistrelle bat was predicted to be 9.5 × BMR with a range of 7.0–12.2 × BMR. We suggest that since a major portion of the cost of echolocation may result from contraction of the pectoralis and scapularis groups of muscles, the cost of echolocation is reduced for flying animals which contract these muscles anyway during flight. This may account for the high incidence of echolocation systems amongst flying vertebrates, when compared with terrestrial species.     

Trophic interactions in soils as they affect energy and nutrient dynamics. IV. Flows of metabolic and biomass carbon

Flows of biomass and respiratory carbon were studied in a series of propylene-oxide sterilized soil microcosms. One-half of the microcosms received three pulsed additions of 200 ppm glucose-carbon to mimic rhizosphere carbon inputs. Biotic variables were: bacteria (Pseudomonas) alone, or amoebae (Acanthamoeba) and nematodes (Mesodiplogaster) singly, or both combined in the presence of bacteria.Over the 24-day experiment, respiration was significantly higher in the microcosms containing the bacterial grazers. Biomass accumulation by amoebae was significantly higher than that by nematodes. The nematodes respired up to 30-fold more CO₂ per unit biomass than did amoebae. Similar amounts of carbon flowed into both respiratory and biomass carbon in microcosms with fauna, compared with the bacteria-alone microcosms. However, partitioning of available carbon by the microfauna varied considerably, with little biomass production and relatively more CO₂-C produced in the nematode-containing microcosms. The amoebae, in contrast, allocated more carbon to tissue production (about 40% assimilation efficiency) and correspondingly less to CO₂.