Skeletal asymmetry and hand preference during termite fishing by gombe chimpanzees

Skeletons of chimpanzees with recorded life stories allow assessment of the potential relationships among hard tissue features and expressed behaviors. We analyze bone size, weight, and mineralization to assess osteological characters for identification of laterality of expressed behaviors involving the upper body. Results show that associations are not yet clearly defined.     

Genomic structure,expression and evolution of the alfalfa aspartate aminotransferase genes

Genomic clones encoding two isozymes of aspartate aminotransferase (AAT) were isolated from an alfalfa genomic library and their DNA sequences were determined. The AAT1 gene contains 12 exons that encode a cytosolic protein expressed at similar levels in roots, stems and nodules. In nodules, the amount of AAT1 mRNA was similar at all stages of development, and was slightly reduced in nodules incapable of fixing nitrogen. The AAT1 mRNA is polyadenylated at multiple sites differing by more than 250 bp. The AAT2 gene contains 11 exons, with 5 introns located in positions identical to those found in animal AAT genes, and encodes a plastid-localized isozyme. The AAT2 mRNA is polyadenylated at a very limited range of sites. The transit peptide of AAT2 is encoded by the first two and part of the third exon. AAT2 mRNA is much more abundant in nodules than in other organs, and increases dramatically during the course of nodule development. Unlike AAT1, expression of AAT2 is significantly reduced in nodules incapable of fixing nitrogen. Phylogenetic analysis of deduced AAT proteins revealed 4 separate but related groups of AAT proteins; the animal cytosolic AATs, the plant cytosolic AATs, the plant plastid AATs, and the mitochondrial AATs.     

Sequence of the gene for a NAD(P)-dependent formaldehyde dehydrogenase (class III alcohol dehydrogenase) from a marine methanotroph Methylobacter marinus A45

Abstract A fragment of Methylobacter marinus A45 DNA has been cloned and sequenced, and an open reading frame has been identified that could code for a 46-kDa polypeptide. Comparison of the deduced amino acid sequence of the polypeptide against the protein data bank has revealed strong similarity with a number of alcohol dehydrogenases, with highest similarity towards class III alcohol dehydrogenases, which recently have been shown to be identical to glutathione-dependent formaldehyde dehydrogenases. We were unable to measure appreciable levels of NAD(P)-dependent formaldehyde dehydrogenases or alcohol dehydrogenase activities using aldehydes or primary or secondary alcohols in cell-free extracts from batch cultures of M. marinus A45. However, formaldehyde dehydrogenases activity was detected on zymograms. Our data suggest that, although NAD(P)-linked formaldehyde dehydrogenase or alcohol dehydrogenase activities are undetectable in cell-free extracts of most methylotrophs employing the ribulose monophosphate pathway for formaldehyde assimilation and dissimilation, the gene encoding formaldehyde dehydrogenase is present in M. marinus A45 and may be present in more of these organisms as well.     

Determination of l-α-acetylmethadol, l-α-noracetylmethadol and l-α-dinoracetylmethadol in plasma by gas chromatography—mass spectrometry

A method is described for the simultaneous determination of l-α-acetylmethadol (LAAM) and its N-demethylated metabolites, l-α-noracetylmethadol (norLAAM) and l-α-dinoracetylmethadol (dinorLAAM), in plasma by gas chromatography—chemical ionization mass spectrometry. Deuterated internal standards for each analyte serve as carriers and control for recovery during sample purification on a solid-phase extraction column (C₁₈), and subsequent separation and analysis on a DB-17 capillary column. With this method, we have determined levels of LAAM, norLAAM, and dinorLAAM in small volumes of plasma (100 μl). The limit of quantitation for all analytes was approximately 1.0 ng/g plasma and the limit of detection was approximately 0.5 ng/g plasma. An experimental application is also described where these analytes are quantitated in plasma obtained from rats before, during, and after chronic administration of LAAM-HCl. Since this technique affords a selective and sensitive means of detection of LAAM and its active, N-demethylated metabolites in small samples of blood, it may enable patient compliance to be more easily assessed by allowing samples to be collected by a simple finger-prick technique.     

Interaction of oddball probability and primary task type on P300 in the dual-task paradigm

Using a dual-task paradigm with an oddball secondary task, P300 amplitude and latency were studied as a function of factorially manipulated oddball probability (low = .22, high = .44) and primary task type. In addition to a Baselinecondition (oddball task only), three primary tasks were used: (1) Pure Sensory;watching a movie; (2) Pure Motor (manipulating a flashlight); and (3) Sensory/Motor(using the flashlight to trace the outlines of characters in a movie). The findings included the usual significant effects of probability on amplitude. There was also a significant effect of task type on amplitude, and a significant interaction of oddball probability with task type. In the low but not high probability condition, a pure Sensory task depressed P300 amplitude. In both probability conditions, the Sensory/motortask depressed P300 amplitude. Only task type had a significant effect on P300 latency. The results confirm the ability of other labs (using Sensory/motor primary tasks) to demonstrate P300 depression at high oddball probability, in view of the difficulty in our lab of achieving P300 depression with pure sensory tasks and high oddball probabilities. The results are discussed in terms of partial overlap of processing resource pools. A preliminary report of these data was presented at the 1990 meetings of the Society for Psychophysiological Research.     

Morphological and proliferative responses of endothelial cells to hydrostatic pressure: Role of fibroblast growth factor

Subconfluent bovine pulmonary artery endothelial cells on rigid substrates were exposed to 1.5–15 cm H₂O sustained hydrostatic pressure for up to 7 days and exhibited elongation, cytoskeletal rearrangement, increased cell proliferation, and bilayering. The role of basic fibroblast growth factor (bFGF) in the mechanism(s) of these endothelial cell responses to sustained hydrostatic pressure was investigated. Evidence that bFGF was released from endothelial cells exposed to sustained hydrostatic pressure or compression was provided by the following experimental results: (1) Cells exposed to control (3 mm H₂O) pressure displayed intense nuclear and cytoplasmic bFGF staining by immunocytochemical techniques; this staining was absent in cells exposed to 10 cm H₂O for 7 days. (2) Conditioned medium from endothelial cells exposed to 10 cm H₂O for 7 days contained at ansferable, growth-promoting activity exhibiting heparin-Sepharose affinity, lability to both heat and freeze/thawing, and neutralization by anti-bovine bFGF. (3) Suramin (0.1 mM), a growth-factor receptor inhibitor, abrogated the proliferative and morphological responses of endothelial cells exposed to sustained hydrostatic pressure. Endothelial cells exposed to elevated hydrostatic pressure demonstrated no detectable decrement in cell viability as assessed by Trypan blue exclusion. The results of the present study indicate that hydrostatic pressure or compression can induce bFGF release from endothelial cells independent of cell injury or death; bFGF is subsequently responsible for the morphological, proliferative, and bilayering responses of endothelial cells to hydrostatic pressure. © 1993 Wiley-Liss, Inc.     

Effect of Inhibitors of Eicosanoid Metabolism on Release of [3H]Noradrenaline from the Human Neuroblastoma, SH-SY5Y

Abstract: Nordihydroguaiaretic acid (NDGA; a lipoxygenase inhibitor), LY-270766 (an inhibitor of 5-lipoxygenase), and the diacylglycerol lipase inhibitor RG 80267 completely eliminated potassium-evoked release of [³H]noradrenaline ([³H]NA) from the human neuroblastoma clone SH-SY5Y with IC₅₀ values of 10, 15, and 30 μ M , respectively. In contrast, these inhibitors only partially inhibited carbachol-evoked release and had little effect on the calcium ionophore A23187-evoked release of NA in this cell line. Arachidonic acid partially inhibited potassium- and A23187-evoked release but did not reverse the inhibition of potassium-evoked release observed in the presence of RG 80267. These studies suggest that arachidonic acid (or its lipoxygenase products) are not important intermediates in the regulation of exocytosis in SH-SY5Y. This conclusion is strengthened by our studies in which SH-SY5Y cells were grown in medium supplemented with bovine serum albumin-linoleic acid (50 μ M ). Under these conditions there was a selective increase in content of membrane polyunsaturated fatty acids of the ω6 series, including arachidonic acid; however, these changes did not effect potassium-, veratridine-, carbachol-, or calcium ionophoreevoked release of [³H]NA.     

Identification of a developmentally regulated sialidase inEimeria tenella that is immunologically related to theTrypanosoma cruzi enzyme

Sporozoites and merozoites of three species ofEimeria, E. tenella, E. maxima, andE. necatrix, that cause diarrhea in chickens worldwide, were examined for their expression of sialidase (SA) activity. The enzyme was found in three species, and the activity of merozoites was 10–20 times higher than that of sporozoites. The enzyme was resistant to degradation by proteases that are normally present in the intestine, a site inhabited by theEimeria parasites, and it was relatively resistant to heat, with optimum activity being at 40°C, which is within the range of temperature in the chicken intestine (40–43°C).E. tenella SA was immuniprecipitated by monoclonal and polyclonal antibodies raised against theTrypanosoma cruzi SA (TCSA), and enzyme activity was neutralized by these antibodies.E. tenella SA was identified by immunoblots as a doublet of molecular weight 190 000 and 180 000 using, as a probe, anti-TCSA antibodies and antibodies against a synthetic peptide (TR) derived from the long tandem repeat domain of TCSA. Binding of the monoclonal and polyclonal antibodies toE. tenella was completely blocked by TR, but not by an irrelevant peptide (BR). Therefore,E. tenella expresses a developmentally regulated SA that is structurally related to theT. cruzi counterpart. Because of the high SA activity in merozoites, and by analogy with other SA-producing microbes that inhabit mucin-rich epithelia, we suggest that theEimeria SA plays a role in desialylating intestinal mucins to reduce viscosity of the local environment and thereby facilitate parasite migration. The enzyme could also play a role in host cell-parasite interaction.Abbreviations SA sialidase (neuraminidase) - Neu5Ac N-acetylneuraminic acid - 4-MU-Neu5Ac 2-(4-methylumbelliferyl)--N-acetyl-d-neuraminic acid - BSA bovine serum albumin - PBS phosphate buffered saline - PMSF phenylmethylsulfonyl fluoride - PNA peanut agglutinin - Ab antibody - TCN-2 monoclonal antibody toT. cruzi sialidase, anti-Ars, monoclonal antibody top-azophenylarsonate - TCSA Trypanosoma cruzi sialidase     

Elevated frequency of an ETS-1 restriction fragment polymorphism in chronic B-cell leukaemia

We studied the frequency of an SstI polymorphism in 70 patients with chronic B-cell leukaemia (CLL) and 100 normal controls. There was a highly significant difference in the distribution of the three genotypes between the CLL patients and the normal controls (²= 13.46, 2 df, P<0.001). The C2 allele was found more frequently in CLL patients and may be a marker for a predisposition to develop CLL.