Biosynthesis of a β-(1 → 4)-mannan in fenugreek seedlings

A particulate enzymatic preparation, extracted from fenugreek seedlings (Trigonella foenum-graecum) catalyses the transfer of mannose from guanosine diphosphate-[U-¹⁴C]mannose and its incorporation into an alkali-soluble polysaccharide. Chemical and enzymatic study of this polysaccharide reveals the presence of only one type of osidic linkage, namely β-(1 → 4)-s-mannopyranosyl. The influence of some factors on this biosynthesis was studied, as well as the MW of the polysaccharide and the existence of an endogenous acceptor.     

The increase of stature in France

This study is divided in two parts. The first shows that the secular trend of increasing height is far from decreasing and, on the contrary, is accelerating. The second part attacks the problem of the causes of this phenomena. It shows that the increase of stature is linked to all indicators of the conditions of life, without any one factor being predominant. On the other hand, students of the more privileged back-grounds keep on showing this secular trend, though their life standards seems to be at the optimum. Therefore, the cause and the end of this phenomena cannot be demonstrated.     

Histone - induced changes in the cellular growth of synchronized chlamydomonas reinhardii are due to histone H1

The cellular growth ofChlamydomonas reinhardii is modified by the addition of a total exogenous histone fraction. These modifications may be related to chloroplast DNA replication; they are different according to the different classes of histones. The H₁ subfraction seems to be responsible for the effect of the total histone fraction.     

Vasoactive intestinal polypeptide: release into hypophyseal portal blood.

Immunoreactive vasoactive intestinal polypeptide (VIP) was present in portal hypophyseal blood of 24 male rats in concentrations (mean, 995 pg per ml) that were approximately 19 times as high as those in systemic arterial blood (mean, 52 pg per ml). The results demonstrate release of VIP from the hypothalamic-neurohypophyseal complex into the portal circulation, and establish a mechanism for direct influence of the peptide on pituitary function.     

Construction of a colony bank of E. coli containing hybrid plasmids representative of the Bacillus subtilis 168 genome. Expression of functions harbored by the recombinant plasmids in B. subtilis.

Summary A collection of about 2500 clones containing hybrid plasmids representative of nearly the entire genome of B. subtilis 168 was established in E. coli SK1592 by using the poly(dA)·poly(dT) joining method with randomly sheared DNA fragments and plasmid pHV33, a bifunctional vector which can replicate in both E. coli and B. subtilis. Detection of cloned recombinant DNA molecules was based on the insertional inactivation of the Tc gene occurring at the unique BamHI cleavage site present in the vector plasmid.Thirty individual clones of the collection were shown to hybridize specifically with a B. subtilis rRNA probe. CCC-recombinant plasmids extracted from E. coli were pooled in lots of 100 and used to transform auxotrophic mutants of B. subtilis 168. Complementation of these auxotrophic mutations was observed for several markers such as thr, leuA, hisA, glyB and purB. In several cases, markers carried by the recombinant plasmids were lost from the plasmid and integrated into the chromosomal DNA. Loss of genetic markers from the hybrid plasmids did not occur when a rec ^- recipient strain of B. subtilis was used.Abbreviations Ap^R resistance to ampicillin - Tc^R resistance to tetracycline - Cm^R resistance to chloramphenicol - CCC covalently closed circular duplex - Mdal magadalton     

Molecular analysis of the genomic organization of the Hymenoptera Diadromus pulchellus and Eupelmus vuilleti

The genomic organization of two parasitic wasps was analyzed by DNA reassociation. Cot curves revealed a pattern with three types of components. A highly repetitive DNA, accounting for 15 to 25% of the genome, was identified as satellite DNA. The moderately repetitive DNA corresponds to 26 to 42% of the genome in both species, and shows large variations in complexity, repetitive frequency and a number of sub-components between males and females. These variations are seen as resulting from DNA amplification during somatic and sexual differentiation. Dot blot analyses show that such DNA amplifications concern several types of structural and regulatory genes. The presence of repeated mobile elements was studied by the Roninson method to compare the repeated sequence patterns of Diadromus pulchellus and Eupelmus vuilleti with those of Drosophila melanogaster. The occurrence and organization of mobile elements in these Hymenoptera differ from those of the neighboring order of Diptera. The repetitive and unique components define very large genomes (1 to 3 × 10⁹ base pairs). The genomic organization in Parasitica appears to be an extreme drosophilan type. We propose that the germinal genome of these parasitic wasps is primarily composed of satellite DNA blocks and very long stretches of unique sequences, separated by a few repeated and/or variously deleted, interspersed elements of each mobile element family.     

Interactions of surfactin,a biosurfactant fromBacillus subtilis,with inorganic cations

Summary The properties of surfactin, a biosurfactant lipopeptide, were highly modified in the presence of inorganic cations. The micellization of surfactin was favoured by monovalent and, especially by divalent cations with a modification of the molecular area at the air-water interface. Haemolysis of erythrocytes by surfactin was enhanced by low concentrations of divalent cations with an increase of the binding of the lipopeptide to membrane. Inorganic ions induced conformational rearrangements probably due to ion-surfactin associations which modify the surface-active properties.     

Increase of IGF I binding to erythrocyte receptors during the TRH-test: correlation between IGF I binding and thyroid hormone values

The effects of TRH on insulin-like growth factor I receptors were investigated on erythrocytes from 7 GH-deficient children having plasma GH levels less than 10 ng/ml during two provocation tests. Intravenous injection of synthetic TRH (0.2 mg/m2) was followed by a marked increase of IGF I binding on erythrocytes, from 3.9% +/- 0.3% to 5.9% +/- 0.3% (P less than 0.005) after 1 hour and 7.3% +/- 0.4% (P less than 0.005) after 2 hours. The IGF I binding variations were due to an increase in both the receptor affinity and the number of sites. The levels of plasma GH, IGF I, T3, T4, free T4, TSH and prolactin having been determined during the TRH test at 0, 1 hour, and 2 hours after the injection, the increase in the IGF I binding to erythrocytes at the same time correlated with the rise of thyroid hormones: triiodothyronine T3 (P less than 0.001) and thyroxine T4 (P less than 0.005) and not with the level of the other hormones. These findings suggest that thyroid hormones play a role in the regulation of insulin-like growth factor I receptors.     

Identification of a membrane glycoprotein overexpressed in murine lymphoma sublines resistant to cis-diamminedichloroplatinum(II)

A series of murine thymic lymphoma cell sublines was selected in vitro for resistance to cis-diamminedichloroplatinum(II) (CDDP). The level of CDDP resistance correlated with reduced drug accumulation in these cells. A rabbit antiserum was raised against the plasma membrane of a CDDP-resistant subline and used in Western blot analyses. Increased expression of a surface antigen of approximately 200 kDa was observed and found to correlate with the degree of resistance. Further biochemical and immunological studies demonstrated that this is a plasma membrane glycoprotein. However, it is different from the multidrug resistance-associated P-glycoprotein with a molecular weight of about 170,000. We have called this unique CDDP resistance-associated membrane protein CPR-200.