The “happy puppet” syndrome in two siblings

Summary Disomic and trisomic cells of a patient with Down syndrome mosaic were used to study the effect of the additional chromosome 21 against an identical genetic background. The frequency of Ag staining and the participation in satellite associations were determined for each pair of acrocentric chromosomes. The additional chromosome 21 of the trisomic cells and its homologues proved to be regularly Ag positive. Therefore the trisomic cells showed more Ag positive chromosomes and more satellite associations per cell than the diploid cells. Thus, no compensation for the additional rRNA-gene dose could be found in the cells of the trisomic line.     

Purification and some properties of beta-lactamases from Proteus rettgeri and Proteus inconstans

Two beta-lactamases were isolated from strains of Proteus species and purified, one from a strain of P. rettgeri and the other from a strain of P. inconstans. Each enzyme preparation gave a single protein band on polyacrylamide gel electrophoresis. Molecular weights of P. rettgeri and P. inconstans enzymes were found to be 42,000 and 43,000, and their isoelectric points pH 8.7 and 8.6, respectively. The two enzymes presented typical cephalosporinase profiles. Cefmetazole (CS-1170) and cefoxitin, both cephamycin antibiotics, not only resisted hydrolysis by both of the enzymes, but also inhibited their activities competitively. Rabbit antiserum against purified P. rettgeri enzyme inhibited the activity of both purified and crude enzyme preparations from other strains of P. rettgeri so far tested. None of the beta-lactamases produced by other species of Proteus including P. inconstans was inhibited by the antiserum, thus showing that the purified cephalosporinase was of the species-specific types. The enzymological properties of the preparations were compared with those of beta-lactamases derived from other gram-negative enteric bacteria.     

Regulation or procollagen messenger ribonucleic acid levels in Rous sarcoma virus transformed chick embryo fibroblasts

Using cloned cDNAs for pro-alpha 1 and pro-alpha 2 collagen messenger ribonucleic acid (mRNA), we have investigated the regulation of collagen mRNA levels in Rous sarcoma virus (RSV) transformed chick embryo fibroblasts (CEF). We find that both pro-alpha 1 and pro-alpha 2 mRNA levels are decreased approximately 10-fold in CEF transformed by either the Bryan high-titer strain or the Schmidt-Ruppin strain of RSV. Using temperature-sensitive mutants in the transforming gene src, we also investigated the rate of change in the levels of the two mRNA species. We employed mutants of both the Bryan high-titre strain (BHTa) and the Schmidt-Ruppin strain (ts68). With both mutants the results were similar. Upon shift from the permissive temperature (35 degrees C) to the non-permissive temperature (41 degrees C), collagen mRNA synthesis, did not increase until more than 5 h had passed, suggesting that action of src on collagen gene expression is indirect. Upon shift from 41 to 35 degrees C, collagen mRNA levels fell with a half-life of 10 h. Whether this fall reflects the half-life of procollagen mRNA or an effect of src on procollagen RNA stability is unclear. Both pro-alpha 1 and pro-alpha 2 mRNA levels were coordinately controlled.     

Biological effects of anti-idiotypic antibodies on lymphocyte function: I. Analysis of the effects on B lymphocytes of combining site and framework-directed anti-T-15 idiotypic antibodies

Anti-idiotypic antibodies against TEPC-15 myeloma protein (BALB/c origin) were raised in allogeneic animals by immunization of A/J mice with the myeloma protein. The antibody activities were fractionated into two specificities by TEPC-15 immunoadsorbent affinity columns by elution with free hapten (phosphorylcholine, PC), followed by elution with acidic buffer (glycine- HCl, pH 2.3). Idiotype binding analysis indicated that the fraction eluted with hapten could be inhibited in its binding to TEPC-15 by free hapten (i.e., binding site-directed anti-idiotypic antibody), whereas the acid-eluted fraction could not (i.e., framework-directed anti-idiotypic antibody). When analyzed for their biological activities on PC-specific B lymphocytes producing T-15 idiotype-bearing antibodies, both anti-idiotypic antibody fractions had similar suppressive effects on the in vitro production of antiphosphorylcholine antibody in culture.     

EFFECT OF STIMULATION OF EXCITATORY NERVE TRACT ON RELEASE OF GLUTAMIC ACID FROM OLFACTORY CORTEX SLICES IN VITRO

Abstract— Thin sections prepared from the olfactory cortex of the guinea pig were incubated in a medium containing [¹⁴C]glutamate, and release of radioactive compounds and electrical activity were subsequently examined in the presence of l -cysteate. The postsynaptic potential was almost completely suppressed in the medium containing l -cysteate, whereas the presynaptic potential was unaffected. Repetitive stimulation of the excitatory input of the lateral olfactory tract enhanced release of radioactive glutamate. The facilitatory effect of lateral olfactory tract stimulation increased with increase in stimulus frequency and was dependent on calcium. Release of radioactive gluiamine was not enhanced by lateral olfactory tract stimulation. Phenobarbitone sodium markedly depressed both the postsynaptic potential and the effect of lateral olfactory tract stimulation on glutamate release. These results indicate that stimulation to the lateral olfactory tract enhances liberation of glutamate from the tract nerve terminals.     

Enzymes of purine catabolism in soybean plants

Remarkable formation and utilization of allantoin is observedin soybean (Glycine max variety A62-1). To study this, variousenzymes involved in purine catabolism (i.e., xanthine oxidase,uricase and allantoinase) were measured in different regionsof soybean plants during development. Uricase, which catalyzesthe direct formation of allantoin from uric acid, was studiedin detail. The activities of these three enzymes were highest in the rootnodules, indicating that the nodules are the major site of allantoinmetabolism. Radicles only showed appreciable activity about80 hr after the seeds were planted. Allantoinase activity wasdetected in all regions tested, showing that allantoin translocatedfrom the nodules can be metabolized in the roots, stem and leaves.In the nodules, xanthine oxidase was localized in the nuclearfraction, while uricase was mainly restricted to the mitochondrialfraction and allantoinase to the soluble fraction. Uricase was partially purified from the nodules and radicles,respectively. The pH optimum of enzyme from the nodules was9.5, whereas that of enzyme from the radicles was 7.0. The enzymefrom the nodules did not require a cofactor, while that fromthe radicles showed an absolute requirement for a cofactor,which was a low molecular substance easily separable from theapoprotein. Thus, the uricase in nodules differs in chemicalproperties from that in the host plant. The results are discussedin relation to change in the allantoin level in soybean tissues. (Received November 1, 1974; )