Chemical modifications of G418 (geneticin): Synthesis of novel readthrough aminoglycosides results in an improved in vitro safety window but no improvements in vivo

G418 is currently the most potent and active aminoglycoside to promote readthrough of eukaryotic nonsense mutations. However, owing to its toxicity G418 cannot be used in vivo to study readthrough activity A robust and scalable method for selective derivatization of G418 was developed to study the biological activity and toxicity of a series of analogs. Despite our synthetic efforts, an improvement in readthrough potency was not achieved. We discovered several analogs that demonstrated reduced zebra fish hair cell toxicity (a surrogate for ototoxicity), but this reduction in cellular toxicity did not translate to reduced in vivo toxicity in rats.

New in Vitro Assay Measuring Direct Interaction of Nonsense Suppressors with the Eukaryotic Protein Synthesis Machinery

Nonsense suppressors (NonSups) induce "readthrough", i.e., the selection of near cognate tRNAs at premature termination codons and insertion of the corresponding amino acid into nascent polypeptide. Prior readthrough measurements utilized contexts in which NonSups can promote readthrough directly, by binding to one or more of the components of the protein synthesis machinery, or indirectly, by several other mechanisms. Here we utilize a new, highly purified in vitro assay to measure exclusively direct nonsense suppressor-induced readthrough. Of 16 NonSups tested, 12 display direct readthrough, with results suggesting that such NonSups act by at least two different mechanisms. In preliminary work we demonstrate the potential of single molecule fluorescence energy transfer measurements to elucidate mechanisms of NonSup-induced direct readthrough, which will aid efforts to identify NonSups having improved clinical efficacy.

Utility of the Arabidopsis FAE1 and yeast SLC1-1 genes for improvements in erucic acid and oil content in rapeseed

High-erucic acid (HEA) Brassica napus cultivars are regaining interest in industrial contexts. Erucic acid and its derivatives are important renewable raw materials utilized in the manufacture of plastic films, in the synthesis of Nylon 13,13, and in the lubricant and emollient industries. Theoretically, the highest level of erucic acid that can be achieved by means of classical breeding is 66 mol%; however, using new approaches on the basis of genetic engineering, it might be possible to develop a B. napus cultivar containing levels of erucic acid significantly above 66 mol% (>80 mol%). In an attempt to increase the amounts of very-long-chain fatty acids (VLCFAs), and erucic acid in particular, in Canadian HEA B. napus cultivars, we have focused on two targets using a transgenic approach. We examined both the role/function of the Arabidopsis thaliana FAE1 (fatty acid elongase) gene by expressing it under the control of the seed-specific napin promoter in B. napus germplasm with analysis of the changes in VLCFA content in the seed oil of transgenic lines, and the performance of the yeast SLC1-1 (sphingolipid compensation mutant) in B. napus cv. Hero transgenic progeny in the field. Here, we report analyses of the contents of 22:1, total VLCFAand oil in the seed oil, as well as seed yield of the field-grown FAE1 and SLC1-1 B. napus cv. Hero progeny.

Simulation of mirages

A mirage is seen when atmospheric refraction distorts or displaces an image. We describe a mirage simulator that uses digital imaging equipment to generate mirage images from normal photographs. The simulation program relocates horizonal image lines into positions that they appear to occupy, according to rays traced from observer to object. Image-brightness adjustments are not required; we show that, while the atmosphere can change the size or shape of an object, it does not change its apparent brightness. The realistic quality of the computed images makes this simulator a useful tool in mirage analysis.

Economic activity and occupation in the Pacific Islands: issues of census classification and analysis

The author discusses the census assessment of economic activity and occupation in the Pacific Island nations of Oceania. "In the Pacific Islands, subsistence and certain kinds of cash activities are often overlooked, and this omission tends to make vulnerable groups, especially women, less visible to planners and politicians. Some progress has been made in incorporating nonwage and noncash activities into recent classification systems used in censuses. One of the purposes of the new International Classification of Occupations...is to provide an improved system of classification for such activities.... Also needed in the Pacific are systems for providing more meaningful data collection and analysis on the relationship between individual and household activities."

Posed emotional expression in unilateral brain damaged patients

The facial expressions of six basic emotions were posed by two groups of right (N = 23) and left (N = 34) brain damaged patients and by a control group of normal subjects (N = 28). The posed expressions were examined by means of the Facial Action Coding System (FACS) which provides analytical and objective scoring, as by a subjective scale of appropriateness of expression. Results indicated no difference between controls and patients with a lesion in the right or left hemisphere. These findings are inconsistent with the hypothesis that the right hemisphere plays a specific role in the control of posed facial expression. No relationship was observed between posed emotional expressions and facial paralysis or the presence of oral apraxia.

Spontaneous facial expression of emotions in brain-damaged patients

Spontaneous facial expression of emotion was studied in two groups of right (N = 23) and left (N = 39) brain-damaged patients and in a control group of normal subjects (N = 28). To elicit emotions four short movies, constructed to produce positive, negative or neutral emotional responses, were used. The method used to assess the facial expression of emotions was the Facial Action Coding System. Brain-damaged patients showed less facial responses to emotional stimuli than normal controls, but no difference was observed between subjects with right and left-sided lesions either with global or disaggregated data analyses, inconsistent with the hypothesis of a specialization of the right hemisphere for facial emotional expressions. An unexpected difference was observed in response to the unpleasant movie. Both normal controls and left brain-damaged patients often averted their gaze from the screen when unpleasant material was displayed, whereas right brain-damaged patients rarely showed gaze aversion. This finding suggests that the degree of emotional involvement or manner of coping with stressful input may be reduced as a result of right brain damage.

What you say and how you say it: The contribution of speech content and voice quality to judgments of others

In three studies, judgments based on separated channels (speech content, voice quality, face alone and body alone) were correlated with judgments based on combined channels (speech, face + speech, and face + body + speech). The judges observed spontaneous behavior in two different types of interview situations and rated various aspects of the behavior. Correlations between separated and combined channels varied significantly depending on the kind of behavior judged, the attribute rated, and whether other channels of information were available.

A behavioral phenotype in the de Lange syndrome

The behavior of nine patients with the de Lange syndrome was studied using videotape, a recording protocol of eight standardized stimulus conditions, and a visual, digital time reference which permitted precise coding and quantitative analysis. These patients avoid or reject social interactions and physical contact, and they do not distinguish in this between a stranger and the mother or her substitute. Social interactions with the adult stranger were scored in patients 1-7 as negative for 28-56 sec/min, whereas they were positive for 1-6 sec/min. Statistical significance was at the level of P less than 0.01. In the case of the mother negative responses ranged from 21-45 sec/min and positive from 3-27 sec/min. The patients exhibit infrequent facial expressions of emotion, and frequently display stereotypic movements. On the other hand, vestibular stimulation or vigorous movement appeared to be an effective means of eliciting pleasurable responses. When held in arms in the vertical position only one of nine children smiled at all and the frequency for that child was 0.8/min. When the child was bounced vigorously in the same position, all smiled but who was too large to be bounced. In the eight the frequency of smiling ranged from 0.8-3.6/min. The data obtained indicate that a specific behavioral phenotype is associated with this syndrome.

Bicycle ergometer measurement of maximal oxygen uptake in children

Seven to 15 maximal exercise tests on a cycle ergometer were done on twenty boys, 11 to 15 years of age, until the work load was sufficiently high that it could not be sustained for 3 min. The mean maximal pulse rate was 202 beats/min, and the mean maximal oxygen uptake was 53.8 ml/kg per min. A plateau of the oxygen uptake curve occurred in only 7 of the 20 subjects, whereas the pulse rate reached a plateau in 13 subjects. On the basis of the pulse rate – work load straight line relationship for submaximal exercise, the intensity of the load that the subjects were able to complete was such that a mean predicted pulse rate of 247 beats/min would have resulted. This information can be utilized to obtain maximal oxygen uptake from a single test in children.