On electron transfer.

The tunneling transfer of electrons between two sites, appropriate to biological intermolecular electron transfer, contains physical considerations which are not important in the tunneling transfer between two metals. Analyses (such as the recent one by Hales) based on the well-known formula for the latter but applied to the former case are quantitatively and qualitatively misleading.     

Murine transfer factor. III. Specific interactions between transfer factor and antigen

The interactions between dialyzable transfer factor and antigens have been studied. Incubation of transfer factor-containing dialysates from ferritin-sensitized mice or ferritin-coated plastic surfaces removed the antigen-sensitizing activity; incubations of the same preparations on cytochrome c-coated surfaces did not. Similar results were obtained when cytochrome c-transfer factor was studied. Incubation on cytochrome c-coated surfaces removed the activity, but incubation on ferritin-coated surfaces did not. Specific transfer factor activities could be recovered by elution with 8 M urea or acetonitrile. The finding of interactions between transfer factor and antigens provides evidence for a molecular basis of the specificity of the immunologic effects of transfer factor. This technique may also enable us to obtain amounts of specific material that are adequate for chemical analysis.     

Photodynamics of excitation energy transfer in self-assembled dyads. Evidence for back transfer.

Three self-assembled photonic dyads comprising a zinc porphyrin donor and a free base acceptor have been studied by time-resolved fluorescence spectroscopy. The driving force of the assembly is the site selective binding of an imidazole connected to a free base porphyrin. Three spacers have been incorporated between the imidazole connector and the free base porphyrin, providing three different distances separating the donor and the acceptor. The high efficiencies and the rates of energy transfer in the set of dyads is consistent with the Forster energy transfer mechanism. Evidence for Forster back transfer has been obtained, and its efficiency and rate have been quantitatively evaluated for the first time.     

Patents and technology transfer.

Although the discovery and transfer of technology from universities to industry has been taking place for many years, the surge of activity in areas related to biotechnology, over the past fifteen years, has been remarkable. As the very essence of university research requires rapid publication of results, it is particularly important that timely patenting activity take place if an orderly and profitable transfer of technology is to occur.     

The cross-hand finger transfer.

This report is of the first successful case we know of transplantation of a ray (finger and metacarpal) from one hand to another. The transfer was accomplished by a two-stage pedicle technique. The tendons and nerves were left long in the donor finger, and were anastomosed at the second stage when the pedicle was divided. Good sensation was obtained. Active tendon function resulted, with excellent power and range of motion in all of the digits of both hands.     

Human transfer factor. II. Clinical results with the large pool transfer factor

21 patients with diseases due to immunological causes were treated 6 times at an interval of four weeks by administering 5 E TF or 1 E TF each per 10 kg of body weight. TF consisted of 5 different large pool TF charges of 420 to 822 buffy-coats of fresh stored whole blood. Clinical and immunological investigations as well as biochemical ones in the laboratory were made before and after treatment. Large pool TF is clinically effective in 9 from 18 patients and immunologically in 16 from 18 patients. There is a greater effect in immunodeficiencies than in autoimmune diseases. TF is not able to remove the defect for a long time. Repeated administrations are required. TF therapy may be regarded as a substitution therapy. At first, the intervals have to be chosen according to clinical parameters (recidive of the disease or crisis respectively). There is a good compatibility of TF. Side-effects could not be observed. The frequent immunological conversions after score evaluation indicate, however, that in comparison to the clinical appearance the course of the disease must be seen to be much more complex than it can be expressed by in vitro correlates of immunological responses. Statistically ensured correlations of single tests concerning the clinical course could also not be found. Large pool TF provides favourable conditions for controlled therapy trials in order to elucidate those findings of therapy which hitherto had been a subject of controversy (e.g. autoimmune diseases, tumours).     

New gene transfer methods.

The intentional introduction of recombinant DNA molecules into a living organism can be achieved in many ways. Viruses have been making a living by practicing gene transfer for millennia. Recently, man has gotten into the act. The paradigm employed is fairly straightforward. First, a way must be found to move genetic information across biological membrane barriers. Then, presumably, DNA repair mechanisms do the rest. The array of methods available to move DNA into the nucleus provides the flexibility necessary to transfer genes into cells as physically diverse as sperm and eggs. Some of the more promising alternative strategies such as sperm-mediated gene transfer, restriction enzyme-mediated integration, metaphase II transgenesis, and a new twist on retrovirus-mediated gene transfer will be discussed, among other methods.     

Plasmid transfer in Pediococcus spp.: intergeneric and intrageneric transfer of pIP501.

Transfer of the broad-host-range resistance plasmid pIP501 from Streptococcus faecalis to Pediococcus pentosaceus and Pediococcus acidilactici occurred between cells immobilized on nitrocellulose filters in the presence of DNase. Expression of the pIP501-linked erythromycin and chloramphenicol resistance determinants was observed in transconjugants. Intrageneric transfer of pIP501 from a P. pentosaceus donor to various pediococcal recipients occurred at frequencies of 10(-4) to 10(-7) transconjugants per input donor cell. Intergeneric transfer of plasmid pIP501 from P. pentosaceus to S. faecalis, Streptococcus sanguis (Challis), and Streptococcus lactis was observed. Similar mating experiments showed no evidence for the transfer of the broad-host-range R-plasmid pAM beta 1 to Pediococcus spp. recipients.     

Nigericin-induced charge transfer across membranes.

The electric properties of the bilayer lecithin membranes have been studied in the presence of the antibiotic nigericin. When the antibiotic concentration is about 10(-7) ohm-1 cm-2. The potassium ion concentration gradient gives rise to a transmembrane potential of the order of 40 mV per 10-fold concentration gradient with the side of the higher potassium concentration negative. The transmembrane potential produced by the hydrogen ion concentration gradient is a function of the potassium ion concentration which is equal on both sides of the membrane. For low potassium ion concentrations the hydrogen potential has the expected polarity with the solution having higher concentration of protons negative. For potassium ion concentrations exceeding 0.03 M the hydrogen potential has the reverse polarity. This unexpected result cannot be accounted for in terms of the available simple hypotheses about the charge transport mechanism for nigericin in BLM. In order to account for the experimental results obtained, a theoretical approach has been developed based on the assumption that charge is transported across the membrane by nigericin dimers. The theoretical predicitons are in satisfactory agreement with the experimental results. The model also yields some predictions which may be verified in future experiments.