Partial and total iodide organification defect in different sibships in a kindred.

Identical twins with goiter but without intellectual retardation and with slightly delayed bone age were found to have defective iodide organification as demonstrated by incomplete perchlorate discharge tests. They are grandnieces of a normal member of a sibship which included four children with severe retardation and complete thyroid iodide organification defect. The parents and grandparents are not consanguine. Possible explanations are considered for the problem of why the disorder is manifest completely in one sibship and only partially in the other.     

Culture conflict and coping in a group of aboriginal adolescents

Critical incidents adapted to presentation in picture form were used to investigate responses of Aboriginal adolescents from Elcho Island mission in the Northern Territory of Australia in conflict situations arising from culture contact. These Aboriginal youths are part of a complex environment where choice behaviour is mediated by specific and broader situational characteristics of the social environment. Results showed a relationship between conflict responses and orientation to traditional values and skills, but no apparent relationship between conflict responses and modern value orientation or psychopathology variables. Adolescents who attended high school in Darwin were seen as more mission and academically oriented than locally educated youth. Contrary to expected patterns, males appeared to be less involved in both mission and traditional activities and more restricted by traditional social expectations than were females.     

Delta opioid receptor selectivity induced by conformational constraints in linear enkephalin-related peptides: 1H 400-MHz NMR study and theoretical calculations

Introduction into the structure of the linear hexapeptide DSLET (Tyr-D-Ser-Gly-Phe-Leu-Thr) or DTLET (Tyr-D-Thr-Gly-Phe-Leu-Thr) of tert-butyl groups as constraints different from cyclization leads to a large increase in the selectivity for delta opioid binding site in the case of DSTBULET [Tyr-D-Ser-(OtBu)-Gly-Phe-Leu-Thr] (Ki delta = 6.14 nM; Ki mu = 374 nM) and BUBU [Tyr-D-Ser(OtBu)-Gly-Phe-Leu-Thr(OtBu)] (Ki delta = 4.68 nM; Ki mu = 475 nM) or a loss of affinity for DTTBULET [Tyr-D-Thr(OtBu)-Gly-Phe-Leu-Thr] (Ki delta = 866 nM; Ki mu = 4500 nM). This puzzling behavior is studied here by 400-MHz 1H NMR spectroscopy in DMSO-d6 solution and by theoretical calculations. When DSLET and DTLET are compared, the reduction in energetically accessible phi and psi angles induced by the tert-butyl group in the D-Ser2 residue decreases the degree of freedom in the N-terminal part of the peptides. For DSTBULET and BUBU, the rigidification of the backbone evidenced by the appearance of the large NOE's of Phe4 NH-Gly3 alpha and Gly3 NH-alpha and by the loss of the C7 folding around the D-Ser2 residue found in DSLET could explain the drastic loss of affinity for mu opioid receptors. In DTTBULET, a large change in the spatial orientation around the D-Thr2 (OtBu) residue forces the aromatic rings far from each other.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characterization of ribonucleolytic activity of angiogenin towards tRNA

Yeast tRNA is a convenient substrate for the assay of the ribonucleolytic activity of human angiogenin. The optimal pH, [NaCl], and temperature for tRNA cleavage by angiogenin are approximately 6.8, 15-30 mM, and approximately 55 degrees C, respectively, as compared with approximately 8.0, 100-200 mM, and approximately 65 degrees C, respectively, for RNase A. Polyanions and metals both inhibit angiogenin and RNase A but to different extents.     

Elastic strain energy storage in the feet of running monkeys

Monkeys are 'flat–footed' in comparison to humans, but they are still able to utilize elastic strain energy stores in their feet to reduce the metabolic energy cost of running. During contact with the ground, bending moments act on the foot to produce a 'reversed arch', storing strain energy which is returned in the subsequent elastic recoil. This energy–saving mechanism has been investigated in dynamic bending tests and is discussed in relation to the arched foot of humans.     

Cloning of nisin resistance determinant and replication origin on 7.6-kilobase EcoRI fragment of pNP40 from Streptococcus lactis subsp. diacetylactis DRC3

The nisin resistance determinant and an origin of replication on pNP40, a plasmid of about 60 kilobases that is present in Streptococcus lactis subsp. diacetylactis DRC3, was cloned on a 7.6-kilobase EcoRI fragment. When self-ligated, this fragment existed as an independent replicon (pFM011) and contained a 2.6-kilobase EcoRI-XbaI fragment encoding nisin resistance.     

Cationic ferritin uptake by cultured anterior pituitary cells treated with the proteinase inhibitor, BOC-DPhe-Phe-Lys-H

Cultured cells from the anterior pituitary glands of adult rats were treated with the tripeptide aldehyde proteinase inhibitor, BOC-DPhe-Phe-Lys-H. The addition of this tripeptide aldehyde decreased the in vitro release of prolactin to 25% of the control value, while the release of growth hormone in the same cultures decreased to 33% of the control value. Prolactin immunostaining was stronger in semithin sections of proteinase-inhibitor-treated cultures than in control sections. After 2 h treatment with the inhibitor, prolactin- and growth hormone-containing secretory granules were numerous, and the number of crinophagic vacuoles had increased. In the presence of the inhibitor, the overall cytoarchitecture of parenchymal cells was well preserved, and the pathway of the uptake of cationic ferritin appeared to be unaffected.