Crescent mastopexy and augmentation

We have defined a group of patients with a lesser degree of moderate breast ptosis whose ptosis correction is not adequately improved by augmentation alone but requires some elevation of the nipple-areola complex. We have selected the crescent excision mastopexy to provide this additional needed lift. Experience with 26 patients employing this technique has helped to define the indications and limitations for this approach. It seems to adequately provide the additional needed lift when nipple descent has been no more than 1.5 to 2 cm below the inframammary crease. Complications such as scar widening (46 percent) were reviewed, but seemed to be well tolerated by the patients.     

Cytoplasmic effects on the tissue culture response of wheat (Triticum aestivum) callus

Summary Calli were initiated from immature embryos of eight lines of hexaploid wheat (Triticum aestivum L. em. Thell) with different cytoplasms, the euplasmic nuclear donor Chinese Spring and seven alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. The calli were found to differ in their initial growth rates, their sensitivity to 2,4-D and their ability to organise shoot primordia, demonstrating that the cytoplasm can significantly affect the behaviour of tissues in culture. The potential for improving the responses of tissues in culture by cytoplasmic changes is noted.     

Reduced pyridine nucleotides in Pseudomonas carboxydovorans are formed by reverse electron transfer linked to proton motive force

In cell suspensions of Pseudomonas carboxydovorans pulsed with lithotrophic substrates (CO or H₂) in the presence of oxygen, formation of reduced pyridine nucleotides and of ATP could be demonstrated using the bioluminescent assay. Experiments employing base-acid transition, an uncoupler and inhibitors of ATPase or electron transport enabled us to propose a model for the formation of NAD(P)H in chemolithotrophically growing P. carboxydovorans.The protonophor FCCP (carbonly-p-trifluormethoxyphenylhydrazon) inhibited both, formation of NAD(P)H and of ATP. In the absence of oxygen, a chemical potential imposed by base-acid transition resulted in the formation of NAD(P)H and ATP when electrogenic substrates (CO or H₂) were present. This suggests proton motive force-driven NAD(P)H formation. The proton motive force was generated by oxidation of substrate, and not by ATP hydrolysis, as obvious from NAD(P)H formation during inhibition of ATP synthesis by oligomycin and N,N-dicyclohexylcarbodiimide.That the CO-born electrons are transferred via the ubiquinone 10-cytochrome b region to NADH dehydrogenase functioning in the reverse direction, was indicated by inhibition of NAD(P)H formation by HQNO (2-n-heptyl-4-hydroxyquinoline-N-oxide) and rotenone, and by resistance to antimycin A.We conclude that in P. carboxydovorans, growing with CO or H₂, electrons and a proton motive force, generated by respiration, are required to drive an reverse electron transfer for the formation of reduced pyridine nucleotides.Abbreviations CODH carbon monoxide dehydrogenase - DCCD N,N-dicyclohexylcarbodiimide - FCCP carbonyl-p-trifluormethoxyphenylhydrazon - HQNO 2-n-heptyl-4-hydroxyquinoline-N-oxide - pmf proton motive force     

Diagnostic Procedure for Detection of Viroids and Viruses with Circular RNAs by "Return"–Gel Electrophoresis

A gel electrophoretic technique for the rapid and sensitive detection of viroids and virusoids is described. Starting from plant material, a typical analysis requires less than 5 hours. Viroid concentrations as low as 800 pg/g tissue can be detected unambiguously without the use of radioactivity, organic solvents, or highly specialized laboratory equipment. The sensitivity may be further increased by introducing additional purification steps. The technique is an essential improvement of the previously published bidirectional gel electrophoretic analysis (Schumacher et al.1983, Anal. Biochem. 135, 288–295). In the new procedure gel electrophoresis is first carried out under native conditions. Before the viroid (or virusoid) bands will leave the gel, conditions are changed to provide denaturing conditions which are achieved by increasing the temperature and changing the buffer. After changing the polarity of the electric field all nucleic acids in the gel “return” in that they now migrate towards their original starting point. Under the denaturing conditions in the second electrophoresis viroids (or virusoids) unfold into the conformation of a circle without in tramolecular base pairs, which structure is unique among the nucleic acids in the gel. The denatured circular viroids migrate in the gel much slower than all other nucleic acids of comparable molecular weight and, therefore stay well separated behind the edge of the other nucleic acids. Thus, viroids can easily be detected on the stained gel as a discrete band.     

Triiodothyronamine--a beta-adrenergic metabolite of triiodothyronine?

Triiodothyronamine (Triam) is a potential metabolite of triidothyronine (T3), resulting from decarboxylation of the side-chain. In an attempt to elucidate the physiological properties of Triam we have investigated the binding of Triam to beta-adrenergic receptors, using turkey-erythrocytes and performing binding studies with ( (-)(3H)-dihydroalprenolol) ( (-)(3H)-DHA) as a specific beta-adrenergic ligand. The inhibition constant Ki for Triam was determined as 5 X 10(-6) M, compared to dopamine (Ki = 1,3 X 10(-2) M), norepinephrine (Ki = 3 X 10(-4) M), epinephrine (Ki = 5 X 10(-5) M) and isoproterenol (Ki = 3 X 10(-6) M). The inhibition of ( (-)(3H)-DHA)-binding by Triam was further compared with other iodothyronines thyroxine (T4), T3, 3,3',5'-triiodothyronine (rT3) and 3,3'-diiodothyronine (3,3'-T2). It is concluded that Triam binds to beta-adrenergic receptors like naturally occurring amines but different from typical circulating iodothyronines.     

Physical analysis of the genomes of hybrid phages between phage P1 and plasmid p15B

The genomes of three plaque-forming recombinant phages between phage P1 and plasmid p15B were characterized by restriction cleavage analysis and electron microscopic heteroduplex studies. The structure of all three P1-15 hybrid genomes differs from that of P1 DNA in the res mod region coding for restriction and modification systems EcoP15 and EcoP1, respectively. P1-15 hybrid 2 shows an additional major difference to P1 around the site of the residential IS1 element of P1 and it does not carry an IS1 in its genome.     

In vitro incorporation of 2′-deoxyadenosine and 3′-deoxyadenosine into yeast tRNAPhe using tRNA nucleotidyl transferase,and properties of tRNAPhe-C-C-2′dA and tRNAPhe-C-C-3′dA

2′-Deoxyadenosine and 3′-deoxyadenosine (cordycepin) can be incorporated into the 3′-terminal position of tRNA^Phe by tRNA nucleotidyl transferase. tRNA^Phe-C-C-2′dA and tRNA^Phe-C-C-3′dA, missing the cis-diol group at the 3′-terminal end are resistant to periodate oxidation and are not able to form borate complexes. In aminoacylation experiments only the tRNA^Phe-C-C-3′dA proved to be chargeable.