Transgenic plants have become attractive systems for production of human therapeutic proteins because of the reduced risk of mammalian viral contaminants, the ability to do large scale-up at low cost, and the low maintenance requirements. Here we report a feasibility study for production of a human therapeutic protein through transplastomic transformation technology, which has the additional advantage of increased biological containment by apparent elimination of the transmission of transgenes through pollen. We show that chloroplasts can express a secretory protein, human somatotropin, in a soluble, biologically active, disulfide-bonded form. High concentrations of recombinant protein accumulation are observed (>7% total soluble protein), more than 300-fold higher than a similar gene expressed using a nuclear transgenic approach. The plastid-expressed somatotropin is nearly devoid of complex post-translational modifications, effectively increasing the amount of usable recombinant protein. We also describe approaches to obtain a somatotropin with a non-methionine N terminus, similar to the native human protein. The results indicate that chloroplasts are a highly efficient vehicle for the potential production of pharmaceutical proteins in plants.

Patients with central sleep apnea have a diminished cerebrovascular response to PET(CO(2)), especially to hypocapnia. The compromised cerebrovascular reactivity to CO(2) might affect stability of the breathing pattern by causing ventilatory overshooting during hypercapnia and undershooting during hypocapnia.

Carvedilol treatment in patients with heart failure results in a 57% decrease in myocardial FFA use without a significant change in glucose use. These metabolic changes could contribute to the observed improvements in energy efficiency seen in patients with heart failure.

The ability to produce monoclonal antibodies (Mabs) in plants offers the opportunity for the development of an inexpensive method of mucosal immunoprotection against sexually transmitted diseases. To investigate the suitability of plant-expressed Mabs for vaginal preventive applications, we compared a humanized anti-herpes simplex virus 2 (HSV-2) Mab expressed in mammalian cell culture with the same antibody expressed in soybean. We found these Mabs to be similar in their stability in human semen and cervical mucus over 24 h, their ability to diffuse in human cervical mucus, and their efficacy for prevention of vaginal HSV-2 infection in the mouse.

We describe a family of stress-induced, developmentally regulated soybean genes for which cDNAs have been obtained from two different cultivars (Glycine max cv. Mandarin and Glycine max cv. Williams). The mRNAs corresponding to these cDNAs, called SAM22 and H4, respectively, accumulate predominantly in the roots of soybean seedlings but are present at high levels in the roots and leaves of mature plants. SAM22 accumulation is especially dramatic in senescent leaves. In addition, SAM22 accumulation can be induced on young leaves by wounding or by transpiration-mediated uptake of salicylic acid, methyl viologen, fungal elicitor, hydrogen peroxide or sodium phosphate (pH 6.9). Taken together, these data indicate that the genes corresponding to SAM22 and H4 are induced by various stresses and developmental cues. Southern blot analysis indicates that multiple copies of sequences related to SAM22 exist in the soybean genome. We also show that the nucleotide sequences of the cDNAs corresponding to SAM22 and H4 are 86% identical at the nucleotide level to each other and 70% identical at the amino acid level to the 'disease resistance response proteins' of Pisum sativum.

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The effect of anoxia on roots of soybean (Glycine max [L.] Merr., variety 'Williams') was studied at various levels and the results compared to those from previously studied species. While alcohol dehydrogenase (ADH) activity is induced in a manner similar to other plant species, other aspects of the anaerobic response are unique to soybean. assure survival when anoxia prevents mitochondrial activity. Studies at the molecular level have helped define the mechanism of the anaerobic induction of these genes. Lin and Key (15) reported that polysomes exhibit rapid dissociation during anaerobic treatment of soybean. This pioneering study on the effect of anoxia on translation in plants was followed by studies in maize which led to the conclusion that anoxia induces the transcription and accumulation of a new set of mRNAs. Although pre-stress mRNAs are generally still present, only genes that show an increase in transcript accumulation during anoxia are translated, yielding the ANPs. Among the -20 ANPs of maize is ADH (23) as well as other enzymes related to glycolysis such as sucrose synthase (25), phosphoglucoisomerase, aldolase, and pyruvate decarboxylase (cf 6).The present study was undertaken to determine if translation is selectively altered in anaerobically treated soybean seedlings, rather than the observed destruction of polysomes (15) being solely the result of a nonselective reduction in protein synthesis. Additionally, molecular clones related to anaerobically induced mRNAs of maize were used as probes to determine if there is a pattern of mRNA accumulation in soybean similar to that seen in anaerobically treated maize (6,23,25). Our results show that anoxic treatment of soybean seedlings induces the accumulation of ADH mRNA, selective synthesis of ADH protein, and accumulation of enzyme activity. In contrast to maize, the pattern of anaerobic protein synthesis is simpler in soybean and may be at least partially explained by the lack of mRNA accumulation for other genes related to glycolysis. We also compare the flood tolerance of maize and soybean seedlings, and find soybean to be more sensitive to flooding, which may be a result of its simpler molecular response to anaerobic stress. MATERIALS AND METHODS Seed GerminationSeeds of soybean Glycine max (L.) Merr