Acclimatory responses in enzymatic activity and metabolite concentrations in the tropical scorpion Heterometrus fulvipes

1. 1.|Changes in tissue metabolite concentrations and enzyme activities in the pedipalpal (PM) and heart (HM) muscles of the tropical scorpion Heterometrus fulvipes show that the metabolism in PM and HM is fundamentally reorganized following low (18°C) and high (38°C) temperature acclimation.

2. 2.|Changes in metabolite concentrations show that metabolite biosynthesis showed increases after cold acclimation but decreases after warm acclimation.

3. 3.|Similarly, changes in enzyme activities show a preponderance of glycolysis and HMP shunt activity after cold acclimation, while after warm acclimation glycogenolysis, oxidative metabolism and gluconeogenesis predominated.

4. 4.|Higher metabolite concentrations and enzyme activities both before and after thermal acclimation in HM reflect its greater compensatory abilities.

Effects of cytokines on in vitro growth of tumor-infiltrating lymphocytes obtained from human primary and metastatic liver tumors

Summary Tumor-infiltrating lymphocytes (TIL) were isolated from 22 human primary and metastatic liver tumors, and expanded in vitro in the presence of either interleukin-2 (IL-2, 100 U/ml) plus tumor necrosis factor (TNF, 1000 U/ml), IL-2 (1000 U/ml) plus IL-4 (1000 U/ml) or IL-2 (1000 U/ml) alone. TIL proliferated in culture in 20/22 cases. Among different cytokine combinations, TNF and IL-2 were most effective in promoting the outgrowth of CD3⁺ CD8⁺ T lymphocytes (mean ± SEM: 90%±5) in the cultures of TIL from primary liver tumors. Cytotoxicity against autologous tumor cells was demonstrated in all early cultures of TIL from primary liver cancers in the presence of IL-2 plus TNF. In contrast, cultures of TIL derived from colon cancer metastatic to liver had significantly lower levels of autotumor cytotoxicity and proportions of CD3⁺ CD8⁺ cells (40%±13) than those of TIL from primary liver tumors. The addition on day 0 of interferons ( or ) to TIL cultured in the presence of TNF and IL-2, significantly augmented cytotoxicity against autologous tumor. In contrast, incubation of TIL in the presence of IL-4 and IL-2 did not result in increased autotumor responses in the cultures of TIL from primary liver tumors. The expansion (-fold) of TIL (day 30) cultured in the presence of IL-2 alone compared to that in the presence of TNF and IL-2 was significantly greater for hepatocellular carcinoma (median, 280 vs 260) than for autologous peripheral blood lymphocytes (36 vs 27), cholangiocarcinoma (42 vs 51) or TIL from metastatic colon cancer (39 vs 30). Outgrowth of TIL in IL-2 plus TNF offers an opportunity for in vitro enrichment in cells with autotumor cytotoxicity in primary liver tumors. However, this cytokine combination was unable to promote and sustain growth of autotumor effectors from TIL in metastatic liver cancer.Supported by ACS grants IM27 077 and IM588 A (TLW) and Organ Transplant Program Project 1P01-CA-4744501 AZ     

Effect of introducing genetically engineered microorganisms on soil microbial community diversity

Abstract Introducing the genetically engineered microorganism Pseudomonas cepacia AC1100 into soil microcosms resulted in elevated taxonomic diversity determined by phenotypic analyses of culturable isolates and genetic diversity determined by analysis of the heterogeneity of total microbial community DNA reannealing kinetics. The greatest impact occurred when P. cepacia AC1100 was introduced along with the herbicide 2,4,5-T, which P. cepacia AC1100 can degrade. The data suggests that both changes in the balance of populations and genetic recombination contributed to the increased diversity.     

The localisation of an Mr 74,000 major chromatin antigen on native salivary chromosomes of Drosophila melanogaster

An antigen making a major contribution to the immune response to Drosophila melanogaster chromatin resides primarily on a nonhistone charge-class family of proteins of Mr 74,000. Immunofluorescence detects this antigen at interbands, puffs and diffuse bands of D. melanogaster salivary chromosomes isolated without exposure to acid fixatives, and on nucleoplasmic ribonucleoprotein droplets. In the electron microscope, gold labelling reveals the binding of monoclonal antibodies specific for the antigen at chromosomal loci generally bearing putative ribonucleoprotein (RNP) particles. However, the locus 3C 11–12 is remarkable in that it bears putative RNP particles but is virtually unlabelled, suggesting protein specificity at different active loci.     

Taxonomic studies on marine triclads (Turbellaria,Tricladida, Maricola)

The genus Procerodes forms a heterogeneous assemblage of taxa. Although it is premature to attempt phylogenetic weighting of the characters, the genus contains three well delimited subgroups, one with a subantarctic, panaustral distribution, one world-wide in distribution, and one occurring principally in the northern hemisphere. Outside of these subgroups, species in this genus are problematic since a number of their features also occurs in other procerodids. All recognized groups exhibit a wide distributional range. Many of the world-wide taxonomic relations lie on the species level and some at the level of genera. Poor dispersal capacity of extant species of Procerodes suggests that the biogeographic patterns may be very old.     

Movements of some indigenous riverine fish in Sri Lanka

The migratory movements of reproductive potamodromus fish established in man-made tropical lakes in the dry zone of Sri Lanka were determined. It was shown that the nine indigenous riverine species do not spawn in these lakes but move into the upstream channels when sexually mature. The pattern of upstream movement was found to be species-specific although most species showed a diurnal periodicity. It is suggested that the development of totally lacustrine forms of riverine species is very unlikely to occur in the man-made lakes of Sri Lanka because of their relatively short duration time.     

Rhodamine 123 as a probe of transmembrane potential in isolated rat-liver mitochondria: spectral and metabolic properties

The spectral and metabolic properties of Rhodamine 123, a fluorescent cationic dye used to label mitochondria in living cells, were investigated in suspensions of isolated rat-liver mitochondria. A red shift of Rhodamine 123 absorbance and fluorescence occurred following mitochondrial energization. Fluorescence quenching of as much as 75% also occurred. The red shift and quenching varied linearly with the potassium diffusion potential, but did not respond to ΔpH. These energy-linked changes were accompanied by dye uptake into the matrix space. Concentration ratios, in-to-out, approached 4000:1. A large fraction of internalized dye was bound. At concentrations higher than those needed to record these spectral changes, Rhodamine 123 inhibited ADP-stimulated (State 3) respiration of mitochondria (K_i = 12 μM) and ATPase activity of inverted inner membrane vesicles (K_i = 126 μM) and partially purified F₁-ATPase (K_i = 177 μM). The smaller K_i for coupled mitochondria was accounted for by energy-dependent Rhodamine 123 uptake into the matrix. Above about 20 nmol/mg protein (10 μM), Rhodamine 123 caused rapid swelling of energized mitochondria. Effects on electron-transfer reactions and coupling were small or negligible even at the highest Rhodamine 123 concentrations employed. Δψ-dependent Rhodamine 123 uptake together with Rhodamine 123 binding account for the intense fluorescent staining of mitochondria in living cells. Inhibition of mitochondria ATPase likely accounts for the cytotoxicity of Rhodamine 123. At concentrations which do not inhibit mitochondrial function, Rhodamine 123 is a sensitive and specific probe of Δψ in isolated mitochondria.     

Effect of glycerol on plasmid transfer in genetically competent Haemophilus influenzae

Summary The small plasmid pAT4 transformed at characteristically low frequencies those competent Haemophilus influenzae Rd strains that had no DNA homology with this plasmid. Transformation was increased up to 100 times, however, when the recipient cells were exposed to 30% glycerol before plating for transformants. Expression of plasmid resistance markers was then immediate. Ultraviolet irradiation experiments indicated that this large increase was due to release by the glycerol of double-stranded plasmid molecules, presumably from transformasomes. Several other plasmids exhibited the same phenomenon. Dimethylsulfoxide also stimulated plasmid transformation but lysolecithin and high concentrations of NaCl or glucose were ineffective. Glycerol did not increase the efficiency of transformation by either chromosomal DNA or linearized plasmid DNA.     

Primary productivity and related parameters in three different types of inland waters in Sri Lanka

Gross and net primary production together with chlorophyll-a biomass were investigated with respect to depth and diurnal changes in three categories of inland waters (reservoirs, temporary ponds, brackish water lagoons) in Sri Lanka. Ten field sites, in both the dry and wet zones of the island, were investigated. Bimodal productivity profiles were recorded in two of the three reservoirs studied. The diel pattern of net photosynthetic rate varied between sites although peak photosynthetic efficiency occurred at solar noon. Surface photoinhibition was characteristic of the reservoirs and brackish water lagoons but not of the temporary ponds. Mean gross primary production was 3.02 g C m^–2 d^–1 but was higher in the temporary ponds than in the reservoirs. The gross primary production in the brackish water Koggala Lagoon at 0.08 g C m^–2 d^–1 is a record low for tropical lagoons and was 2.5 times less than the two other lagoons investigated. Variability in net primary production between sites was similar to the variation in gross production with a relatively low mean value for tropical inland waters of 0.495 C m^–2 d^–1. Mean maximum photosynthetic rate was 0.30 mg C m^–3 h^–1 but was lower in the reservoirs than in the temporary ponds and lagoons.