A differential scanning calorimetric study of Newcastle disease virus: identification of proteins involved in thermal transitions

The spatial and temporal pattern of expression of enhancer trap lines reporting on the wingless (wg) and engrailed (en) genes was characterized in the adult antenna of Drosophila melanogaster. The time courses of expression seen for wg and en, although different from each other, reveal a complex well-controlled pattern of temporal expression, providing evidence that regulatory mechanisms are preserved throughout the life span of the adult fly. Altering the life span demonstrates that the temporal patterns of expression of both wg and en are linked to life span. These studies suggest that the expression of wg and en in the adult antenna is controlled by age-dependent mechanisms.     

Operation of integrated InGaAsP-InP optical amplifier-monitoringdetector with feedback control circuit

Monolithic integration of a monitoring detector with an optical amplifier simplifies the use of an amplifier in lightwave systems. The structure and performance are described of a monolithically integrated semiconductor optical amplifier with low-loss Y-branching waveguides and a monitoring p-i-n detector. The photocurrent of the integrated detector can be used as a single control parameter for amplifier output leveling, gain optimization, and in situ monitoring of facet antireflective coatings     

Interaction between proteins containing homeodomains associated to leucine zippers from sunflower

A strategy based on the use of PCR with one degenerate oligonucleotide deduced from conserved sequences and lambda gt10 primers was used to isolate homeobox containing sequences from sunflower stem and root cDNA libraries. Six different partial cDNAs coding for the first 48 amino acids of homeodomains and amino terminal sequences were analyzed and found to be members of the HD-Zip superfamily, which contain a homeobox linked to a leucine zipper coding region. A full-length cDNA clone, Hahb-10, was isolated and characterized. The leucine zipper portions of Hahb-10 and of the previously reported Hahb-1 have been utilized to construct fusions with the N-terminal domain of the lambda repressor. These fusions were tested for their ability to bind to lambda promoters in vivo. The expression of a protein containing an active dimerization domain, but not capable of DNA binding, exerts a dominant negative effect on the ability of repressor-zipper fusions to bind to its target DNA. From these experiments, it was concluded that Hahb-1 and -10, when co-expressed, form preferentially homodimers. Exchange of conserved threonines and leucines at positions a1 and d1 of both zippers reduces dimerization efficiency and allows the formation of heterodimers, suggesting that these residues are, among others, determinants of the specificity of interaction, most likely through changes in hydrophobic packing interactions at the dimer interface. The results imply that a great number of interacting molecular entities compose this protein superfamily which is presumably involved in regulating plant developmental responses.     

Hprt- mutation spectrum in a closely related pair of human bladder tumour cell lines after gamma-irradiation at different dose-rates

Inactivation of p53 gene and overexpression of MDR1 gene are both associated with drug resistance. Previous studies have suggested that p53 gene can modulate the expression activity of MDR1 gene promoter in a promoter-CAT system. In the present study, wild-type p53 gene cDNA was introduced into a multidrug-resistant cell line, KBv200, in which endogenous p53 gene is aberrant. In wt-p53 transfected cells, the expression of MDRI gene was significantly increased, accumulation of adriamycin (ADM) was decreased, and the sensitivity to vincristine (VCR), ADM and 5-fluorouracil (5-FU) was increased compared with the parent KBv200 cells. After treatment with ADM and VCR, the p53-transfectants were more susceptible to apoptosis. The results suggest that the increase in drug sensitivity of the cells may be, at least in part, due to p53-dependent apoptosis induced by anticancer agents.     

Is local biotransformation the key to understanding the pharmacological activity of salicylates and gold drugs?

It is suggested that some drugs may be converted by inflammatory cells to yield active species. The transformation may be non-enzymatic, although being driven by the enzymatic production of highly reactive species which are normal products of activated leukocytes, such as singlet oxygen, hydrogen peroxide, hypochlorite, hydroxyl radical and nitric oxide. Drugs which may be transformed in this fashion are the anti-rheumatic gold complexes which may be converted either to aurocyanide or to Au(III) complexes by myeloperoxidase in polymorphonuclear leukocytes. Salicylate may also be activated by its oxidation to dihydroxybenzoates although evidence for its transformation is weaker than for the gold complexes.     

A developmental study of the acquisition of Russian colour terms

We report a study of the acquisition of colour terms by Russian children which had two main aims: first, to test Berlin & Kay's (1969) theory of colour universals using acquisition order as a measure of basicness; and secondly, to see if the two BLUE terms of Russian are genuinely basic. Two hundred children aged from three to six-years-old were tested on three colour-tasks--colour term listing, colour term production and colour term comprehension. To a reasonable approximation, the order of colour term acquisition was in accord with Berlin & Kay's theory, but the data are also consistent with the weaker claim that primary terms tend to be learned before derived terms. On balance the data were consistent with Russian exceptionally, having an extra term for the BLUE region. But, the two BLUE terms--goluboj 'light blue' and sinij 'dark blue'--were confused more often than other pairs of terms even by the five- to six-year-old sample.     

Internal calvarial bone distraction in rabbits with delayed-onset coronal suture synostosis

Recent studies have identified a subpopulation of craniosynostotic individuals who exhibit progressive or delayed-onset synostosis and mild craniofacial growth abnormalities. These individuals may be good candidates for nonextirpation, distraction osteogenesis therapy. The present study was designed to test this hypothesis by using internal calvarial bone distraction in a rabbit model with familial delayed-onset craniosynostosis. Data were collected from 159 rabbits: 71 normal controls, 72 with delayed-onset coronal suture synostosis, 8 with delayed-onset coronal suture synostosis and coronal suturectomy, and 8 with delayed-onset coronal suture synostosis and distraction. At 10 days of age, all rabbits had amalgam markers placed on both sides of the frontonasal, coronal, and anterior lambdoidal sutures. At 25 days of age, correction was accomplished through either a 5-mm-wide suturectomy or distraction osteogenesis. An internal distraction appliance was fixed to the frontal and parietal bones and percutaneously and intermittently activated at an average of 0.10 mm/day for 42 days (4.11 mm total). Serial radiographs were taken at 10, 25, 42, and 84 days of age. Results revealed that rabbits with delayed-onset synostosis had significantly (p < 0.01) reduced coronal suture growth rates (0.04 mm/day) compared with the other three groups (0.07 mm/day). Rabbits with suturectomy and rabbits with distraction showed similar coronal suture responses. However, from 42 to 84 days of age, rabbits with distraction showed reduced growth at the vault sutures and abnormal growth patterns in cranial vault width, cranial vault shape, and cranial base angulation compared with the other three groups. Results demonstrated that, although the normal coronal suture growth rate was maintained in rabbits with delayed-onset synostosis using intermittent distraction osteogenesis, normal adult craniofacial structure was not achieved. Such anomalous growth was probably a result of altered growth vectors and compressive forces at adjacent sutures during distraction. These findings suggest that distraction osteogenesis without corticotomy may be a treatment alternative in individuals with progressive, delayed-onset synostosis, but that internal appliances that generate low-level, continuous distractive forces should be investigated and developed.