Generation of monoclonal antibodies to Macaca mulatta (rhesus) IgA

One IgG1 and five IgM murine monoclonal antibodies (mAb) specific for rhesus (Rh) IgA were generated. These mAbs bound to Rh IgA but not IgG or IgM when tested by enzyme-linked immunosorbent assay. Immunoblotting revealed that the mAbs reacted with the alpha heavy chain of Rh but not human IgA. The IgG1 anti-Rh IgA mAb detected IgA-producing cells in sections of monkey gut examined by immunofluorescent staining. These mAbs should be useful for characterizing IgA responses in the Rh monkey.     

A restraining system for rhesus monkeys used in space research

A new chronic restraining system has been designed specifically for male rhesus monkeys (8–13 kg) housed in weightlessness for scientific purposes. The restraining system consists of a coat (jacket and skirt) and a chair. The system separates the thorax from the lower part of the body, and allows large movements of the upper part of the body. The macaque can feed and groom itself, and can also sleep in close-to-normal position.     

Effects of Odorants on Pigment Aggregation and cAMP in Fish Melanophores

Odor perception within olfactory neuroepithelium and pigment translocation within melanophores both seem to rely on a cAMP-based second messenger system. From studies on cultured frog melanophores, Lerner et al. (Proc. Natl. Acad. Sci. USA 85:261-264, 1988) suggested that some aspect of odor perception may be mediated by a nonspecific mechanism whose signal is transduced by a cAMP-based second messenger system. In the present study, odorants (β-ionone, benzylaldehyde, cineole, cinnamaldehyde, and octanol), which previously have been shown to stimulate formation of cAMP in the olfactory neuroepithelium, were investigated for possible pigment dispersing and cAMP-increasing effects. Pretreatment of fish melanophores with the adenylate cyclase activator forskolin (1 μM) resulted in an approximately 300% increase in cAMP and an almost complete blockage of noradrenaline-induced pigment aggregation. However, none of the tested odorants were able to increase the cAMP level and only cinnaldehyde and β-ionone were found to have any pigment dispersing activity.     

Influence of halophyte plantings in arid regions on local atmospheric structure

The practicality of modifying climate in arid regions through irrigation has up to now been constrained by the availability of fresh water with which to grow crops. The present results suggest a new paradigm: the use of salt water to grow halophyte crops and modify local climate along coastal deserts and other arid regions where saline water supplies are available.     

Mechanisms of quinol oxidation in photosynthesis

The mechanisms by which para-benzoquinols can be oxidized is reviewed. Emphasis is placed on the information available from chemical and electrochemical studies which may provide insight into the biochemical mechanisms of plastoquinol oxidation in the chloroplast. Three mechanisms of quinol oxidation are possible: (1) The removal of an electron from the quinol, QH_inf2^sup·t, directly to produce the radical cation, QH₂^·+. This may be achieved electrochemically only at very high potential in acidic media. The reaction may be of relevance to D₁, the donor to P-680. (2) The removal of an electron from the anionic quinol. QH^–, formed by quinol deprotonation. It is likely that the catalytic mechanism of the cytochrome bf complex involves this mechanism. (3) The removal of an electron from the dianionic quinol, Q^2–. This route will be dominant only under basic or aprotic conditions and at very low potentials.     

Training adaptations of baboons to light and moderate treadmill exercise

We evaluated training adaptations by 18 baboons (Papio cynocephalus anubis) to low and moderate quadrupedal walking exercise on a motorized treadmill. Moderate training produced 47% increases in lactate threshold, 63% increases in muscle citrate synthetase activity, increases in percentage of Type IIc muscle fibers, and reduced plasma insulin concentrations. Low training produced only reduced plasma insulin concentrations. Our results indicate that the baboon response to exercise training was similar to that of Homo sapiens, and dependent on exercise intensity.     

Circadian rhythms

The neurobiological substratum of circadian rhythmicity encompasses three levels of integration: firstly, generation of time signals by circadian pacemakers; secondly, entrainment of pacemakers by environmental influences; thirdly, coupling of circadian pacemakers among themselves and with target systems responsible for the expression of overt rhythms. From recent contributions, the notion that circadian organization results from the interaction of independent oscillators and pathways has been strengthened. In addition, recent evidence supports the existence of circadian rhythmicity in single isolated neurons. New information was produced on the gene control of circadian rhythm generation in Drosophila, as well as interesting advances in the understanding of neuronal mechanisms involved in the generation, entrainment and coupling of circadian rhythms in various species.     

Cell cycle checkpoints

Checkpoints help ensure that cell cycle events occur in the correct order. Studies on mammalian cells identified inhibitors of complexes of cyclins and cyclin-dependent kinases as components of cell cycle checkpoints and provide the first glimpse of the molecular pathways that prevent cells with damaged DNA from replicating their DNA. In embryos, the extent to which checkpoints arrest the cell cycle reflects the relative strength of inhibitory checkpoints and the machinery driving the cell cycle forward.