Translocation (11;14) in B-cell lymphoproliferative disorders

A number of chromosomes other than chromosome No. 8 participate in formation of the 14q+ marker in lymphoproliferative disorders. Among them is chromosome No. 11 which appears to be important because its break points are constant; it is also possibly significant because of its participation in cytogenetic alterations in B-cell disorders.     

Projections of the zona incerta in the cat, with stimulation controls.

In eight cats single electrolytic lesions were placed in the zona incerta, and resultant fiber degeneration studies were made. In seven additional cats, stimulating electrodes were chronically implanted bilaterally into the zona incerta, H₂ (lenticular fasciculus), or H (prerubral) fields of Forel. The animals were placed in a two-compartment shuttle box, and a routinely established procedure of subthalamic stimulation was instituted. When the sensory (nociceptive) or motor manifestations and reactions were established, small lesions were made through both poles of the electrodes. The brains were studied by silver techniques for degenerating axons and terminals. Findings in the latter group of animals with physiologic substrates, compared to those in the first group, indicated that the zona incerta contains at least two major physiologic-anatomic components with differential fiber projections. The first component is a medial zona incerta proper or caudalis, paleospinothalamic, nociceptive-conducting system which causes typical escape responses. Its unequivocal projections are to the nucleus of the H₁ field, posterior and dorsal hypothalamus, part of the intralaminar system, ventromedial and ventralis anterior nuclei, nucleus reuniens, reticular nucleus, pulvinar, posterior nucleus, central gray, red nucleus, and the central tegmental tract. The second constitutent concerns pyramidal-extrapyramidal motor type responses that arise with avoidance reactions from other portions of the zona incerta. In these cases there is heavy projection to the caudate, entopenduncular, globus pallidus, and putamen nuclei. In contrast, degeneration from the nociceptive part of the zona incerta or H₂ and H fields to these nuclei is minimal.     

Refinement of conformational preferences of Leu enkephalin and Tyr-Gly-Gly-Phe by 15 N n.m.r.

15N labeled Tyr-*Gly-*Gly-*Phe (I) and Tyr-*Gly-*Gly-*Phe-*Leu or Leuenkephalin (II) are taken as models to test the ability of 15N n.m.r. as conformational probe for peptide analysis. Analysis of the 3J 15 N-1Hα constants using a Karplus relationship permits the proposal of a 2–5 βII type turn for Leuenkephalin, instead of the previously proposed 2–5 βI bend. In the two peptides, side-chain populations for Phe and Leu residues are computed, without any assignment assumption, by an optimization procedure taking into account all the available vicinal coupling constants (3JHαHβ, 3J 13CO-Hβ, 3J 15N-Hβ). Our results confirm the upfield shift of the β ProR proton relatively to the β ProS for the β CH2 group of Phe residue in Me2SO solution. In both peptides (I) and (II), the tg° rotamer is the most populated for residue Phe4, whereas in (II) only this rotamer is present for the Leu5 sidechain. This feature indicates that the hydrophobic group lies opposite to the N-terminal Tyr residue, a feature not found for the methionine side-chain in Met-enkephalin.     

Synthesis of a tripeptide with a C-terminal nitrile moiety and the inhibition of proteinases

The synthesis of the tripeptide d -Phe-Pro-Arg with the nitrite group instead of the carboxylgroup is described. Initially, the corresponding peptide amide was synthesized by conventional methods in solution using Boc and Fmoc as the protecting group for d -Phe. The dehydration in order to create the nitrite moiety was achieved by treating the peptide amide with phosphorus oxichloride or trifluoroacetic anhydride. Best results were obtained by the use of phosphorus oxichloride in pyridine as the solvent in the presence of imidazole. After deprotection of the N-terminal amino acid the crude product was purified by chromatography on Butyl-Fractogel® HW-40 (S). The purity of the final product was checked on a RP18 phase by hplc. The existence of the nitrite group was demonstrated by i.r. and ¹³C-n.m.r. spectra. The peptide nitrite exhibited a strong inhibition of thrombin compared to the tripeptide amide.     

Effects of alpha-methyl tyrosine and adrenergic blocking agents on the facilitating action of amphetamine and nicotine on learning in rats

dl-amphetamine sulphate (2 mg/kg) and nicotine (0.2 mg/kg) showed a facilitatory action on the acquisition of a conditioned response in a shuttle-box by rats and this was reversed by pretreatment with -MT (30 mg/kg).Pretreatment with dibenamine (10 mg/kg) impaired the action either of amphetamine or nicotine. Nethalide (5–10 mg/kg) exerted a partial protection on the depressant effect produced by the interaction between dibenamine and nicotine.Animals treated with -MT (30 mg/kg) and kept in the cold (4–6° C for 3 h) also showed a depressed learning capacity. dl-Dopa (200 mg/kg) provided a partial protection on the depressive effects caused by the interaction of -MT with amphetamine, nicotine or cold. It is suggested that the facilitatory learning action of amphetamine and nicotine involves a common adrenergic mechanism. The depressant effects of amphetamine, nicotine or cold after -MT treatment are attributed to depletion of functional pools of catecholamines.This work was supported by grant N 2911/67 from the Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina (O. A. Orsingher).     

Action of prostaglandin F2α on the course of pregnancy and plasma 17β-estradiol concentration in mice

The effect of prostaglandin F₂ (2 mg/kg at each stage of development) on the preimplantation development of mice and on their plasma 17-estradiol concentration was investigated. Prostaglandin F₂ inhibited mitotic division in the embryo and reduced the percentage of embryos shedding the zona pellucida. Meanwhile the 17-estradiol concentration in the peripheral blood plasma fell. Under physiological conditions there was a significant increase in the 17-estradiol concentration at the blastocyst stage after shedding of the zona pellucida.Department of Histology and Embryology, Pediatric Faculty, N. I. Pirogov Second Moscow Medical Institute. Laboratory of Endocrinology, Moscow University. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kupriyanov.) Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 88, No. 10, pp. 468–470, October, 1979.     

s-Cis and s-trans isomerism in acylproline analogs

N-Acetyl-2,3-dehydroproline, N-acetyl-5-oxo-L-proline, N-acrylyl-L-proline, N-acetyl-L-azetidine-2-carboxylic acid and N-acetyl-D,L-pipecolic acid have been examined in ²H₂O by ¹H and ¹³Cn.m.r. for the purpose of finding s-cis or s-trans locked acylprolines. Conformationally locked acylprolines could be incorporated into proline-containing peptide hormones such as angiotensin and thyroliberin in order to determine the rotational state of the peptide bond to proline in the hormone receptor complex. The populations of trans and cis rotational isomers were determined as a function of p² H in order to assign the trans and cis isomers and to compare the populations in all the acylprolines at neutral p² H, where the cis isomer is normally present. Proton spectra were also recorded at from 7° to 75° in order to qualitatively determine the exchange rate between the isomers. The majority of these analogs exhibit a cis-trans isomerization similar to that of N-acetyl-L-proline in the ratio of trans to cis rotational isomer found at neutral p² H (about 1:1), the temperature dependence of the population ratio (none), and the coalescence temperature for proton resonances (greater than 75°). However, N-acetyl-5-oxo-L-proline was found to be greater than 98% s-trans at neutral pH, compared to 50% s-trans in N-acetyl-L proline, and therefore a good candidate for synthesis of an s-trans locked peptide hormone. N-Acetyl-2,3-dehydroproline rapidly exchanges between s-cis and s-trans in contrast to all other proline analogs examined and exhibits coalescence of the β-proton cis and trans resonances at 45°. Titration with the shift reagent Pr⁺⁺⁺ was employed to confirm the assignments of the cis and trans methyl resonances of all of the N-acetyl compounds except N-acetyl-5-oxo-L-proline.     

Effects of intraventricular curarimimetics on hippocampal electrical activity

The effects on the hippocampal electroencephalogram (EEG) of intraventricular injections of the nicotinic ligand α-Naja naja toxin, and of d-tubocurarine, were studies in rats immobilized with gallamine or anesthetized with urethane. The EEG recordings were taped and processed off-line to calculate power spectra, autocorrelation functions, and averages. In addition, the times at which spike-and-wave complexes appeared were identified and autocorrelation histograms and cross correlations (with the EEG) were made. Naja toxin and d-tubocurarine provoked a 3.5- to 5-Hz theta rhythm in both hippocampi. Higher doses elicited rhythmic epileptic spike and wave complexes which appeared at a preferred phase of theta rhythm. Atropine and medial septal lesions blocked the rhythm and disrupted the rhythmicity of epileptiform activity. We conclude that different neural subsystems sustain the theta rhythm and epileptiform spikes, and discuss the possible mechanisms involved.