Conformations of satellite DNAs

X-ray fiber diffraction studies of satellite DNAs from Gecarcinus lateralis, Drosophila virilis and Mus musculus, all of which have highly repetitious base sequences but with different degrees of sequence complexity, reveal only classical polynucleotide duplex structures in contrast to some highly repetitious synthetic DNAs.     

Synthesis in vitro of intrinsic membrane proteins by free, membrane-bound, and Golgi apparatus-associated polyribosomes from rat liver

A fraction of intrinsic membrane proteins was prepared from the major membranous cell components of rat liver by extraction of the membranes with KCl and deoxycholate. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the compositions of the intrinsic protein fractions from rough and endoplasmic reticulum, smooth endoplasmic reticulum. Golgi apparatus, plasma membrane, and nuclear envelope were similar to each other but distinct from that of mitochondria. Among endomembranes, differences were in the ratios of protein constituents plus a few protein bands of Golgi apparatus and plasma membranes not found in endoplasmic reticulum or nuclear envelope. The abilities of total rough endoplasmic reticulum, polysomes released from rough endoplasmic reticulum, and free polysomes to incorporate amino acids into the intrinsic protein fraction were tested in vitro. Polysomes bound to endoplasmic reticulum has the greatest capacity to synthesize proteins of this fraction as shown by co-purification of radioactive products and by immunoprecipitation. Although the majority of the radioactive products synthesized by bound polysomes were distinct from those synthesized by free polysomes, certain radioactive products synthesized by free polysomes also co-purified with intrinsic membrane proteins. The results show no absolute segregation between free and bound polysomes in the synthesis of intrinsic membrane proteins. However, the majority of these proteins appear to be synthesized by polysomes bound to the endoplasmic reticulum. Several intrinsic proteins found in plasma membranes do not appear in rough endoplasmic reticulum. To determine where these proteins were synthesized, the ability of other endomembrane components to support in vitro incorporation of [14C]leucine into protein was examined. In contrast to plasma membranes, isolated Golgi apparatus fractions did incorporate [14C]leucine to an extent greater than could be explained by contamination with rough endoplasmic reticulum. Golgi apparatus in situ and isolated from rat liver have polyribosomes associated with a zone of cytoplasm at the Golgi apparatus periphery occupied by tubules and vesicles. The polysomes are not directly attached to membranes as with rough endoplasmic reticulum and may represent a special class of "Golgi apparatus-associated" polysomes. The polysomes, when associated with Golgi apparatus membranes, incorporated amino acids in vitro. The products synthesized in vitro were analyzed by treatment with KCl and deoxycholate and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Certain proteins synthesized by the Golgi apparatus-associated polysomes remained insoluble after the treatment with KCl and deoxycholate. The proteins synthesized by the Golgi apparatus fraction had mobilities similar to proteins in plasma membranes which were absent from endoplasmic reticulum, and which were relatively minor components of Golgi apparatus...     

Transureteroureterostomy for urinary diversion in children

We report here a model of submaximal spinal cord injury, employing direct thoracic cord compression in ferrets. This yields consistent and reproducible long term consequences on local cellular structure and on locomotive function. We show also that both the anatomical and functional losses can be measured objectively using simple techniques, and that useful long-tract mediated locomotion is preserved after severe axonal losses at the site of injury.     

Aminoacylation of Phaseolus vulgaris cytoplasmic, chloroplastic and mitochondrial tRNAsPro and tRNAsLys by homologous and heterologous enzymes

Gamekeeper's thumb is due to complete rupture of the ulnar collateral ligament; it should be clinically differentiated from incomplete rupture. Methods of diagnosis and treatment of gamekeeper's thumb are described. The results in 10 cases of gamekeeper's thumb treated by surgery, with more than a one-year follow-up are evaluated.     

Locally recurrent carcinoma of the breast. Results of radiation therapy

Local and regional recurrences are frequent problems in breast cancer management. Radiation therapy is effective in producing long term remission. This study evaluates the results of radiation therapy of 215 patients with recurrent disease limited to the chest wall and/or regional lymph node areas. The local results showed complete control in 67% of cases (mean and median durations 32 months and 22 months, respectively), partial control in 24% of cases (mean and median 11 and 8 months, respectively) and no control in the remaining 9%. The radiation dose recommended for the treatment of recurrent mammary carcinoma is 5000 rads in 5 weeks for relatively small lesions. Supplementary local doses of 500-1000 rads in 1 week may be given to bulky lesions as necessary for residual disease. Although local relapse indicates a poor prognosis, it is by no means totally hopeless. Of 215 patients treated 44 (21%) survived 5 years and 10 (5%) survived 10 years following radiation therapy of recurrent disease. There were seven patients, or 3%, who were free of cancer at 5 to 15 years. Radiation therapy was valuable in controlling local lesions, and thus, in improving quality of survival, even in those patients who eventually died of metastatic disease.     

Action of amino acids and convulsants on cerebellar spontaneous action potentials in vitro: effects of deprivation of C1-, K+ of Na+

(1) The inhibition of spontaneous action potentials in guinea pig cerebellar cortex slices by GABA, glycine, taurine and beta-alanine is maintained when C1- in the superfusion medium is almost completely replaced by NO3- or I-('permeant' anion), but the inhibition decreases in magnitude with repeated application of the amino acid. Replacement of C1- by sulfate or isethionate ('impermeant' anion) causes a conversion of inhibition by these amino acids to excitation. The initial excitation which is sometimes seen with these inhibitory amino acids in high C1- media is abolished when C1- is replaced by either permeant or impermeant anions. (2) Reduction of K+ in the medium causes an increase of inhibition by the inhibitory amino acids in the presence of high C1- and reduction of excitation when C1- is replaced by impermeant anion. (3) Excitation by GABA in impermeant anion (low C1-) media is unaffected by reduction of Na+ in the media by 50% but excitations by glycine, taurine, beta-alanine and L-glutamate are greatly reduced. (4). Excitation by GABA in impermeant anion (low C1-) media is abolished by picrotoxin and bicuculline which both suppress inhibition by GABA in a high C1- medium. Strychnine suppresses the effects of glycine, taurine and beta-alanine in either a low or high C1- medium. Bicuculline blocks the inhibitory effect of these three amino acids in a high C1- medium but does not affect their excitatory effects in a low C1- medium. (5) These results are consistent with the hypothesis that the inhibitory amino acids, GABA, glycine, taurine and beta-alanine, cause inhibition via increase of C1- (and perhaps K+) permeability and that glycine, taurine and beta-alanine also interact with strychnine-sensitive receptors mediating (perhaps indirectly) increased permeability to Na+ and, therefore, excitation in low C1- media.