Measurement of profiles of potassium activity and electrical potential in the intact root

Summary Profiles of potassium activity and electrical potential in the vacuoles of cells across the intact root of Helianthus annuus have been measured. No gradient in either potassium activity or potential difference was detected from epidermis to pericycle. The trans-root electrical potential was found to be made up of two components, a large P.D. between the outside solution and the outer cells and a small P.D. at the pericycle-xylem interface. The results indicated that all the living cells of the root have the same capacity to actively accumulate potassium.     

The structure and evolution of the spider monkey delta-globin gene

We have isolated the delta-globin gene of the New-World spider monkey, Ateles geoffroyi, and compared its nucleotide sequence with those of other primate delta- and beta-globin genes. Among primate delta-globin genes, the rate of nonsynonymous substitutions is much less than the rate of synonymous substitutions. This suggests that primate delta- globin genes may remain under evolutionary conservation, perhaps because hemoglobin A2 has an as yet unknown physiological importance.      

Blood typing invalidates alleged evidence of fertility of XO mare

A mare with XO gonadal dysgenesis was reported to have produced two foals. Blood samples from the mare, her two foals, their sire and the mare's sire were typed for blood-group and serum protein variants in conjunction with registry requirements. Both foals qualified as offspring of the reported parents. However, the blood-typed mare could be excluded as an offspring of her alleged sire. An alternative hypothesis to explain the blood-type and karyotype findings was that a fertile mare had been substituted for the XO mare, as surrogate mother and blood-type donor. A computer search of 120,000 blood-type records identified only one other horse with the same blood type as the dam of the foals. That horse was a mare of the same breed and owned by the person who had attempted to register foals from the XO mare. These blood-type findings invalidated the allegation of XO fertility and emphasize the need for parentage verification to support reports of unusual reproductive performance.     

Biochemical pathways in prokaryotes can be traced backward through evolutionary time

For the first time, a credible prokaryotic phylogenetic tree is being assembled by Woese and others using quantitative sequence analysis of oligonucleotides in the highly conservative rRNA. This provides an evolutionary scale against which the evolutionary steps that led to the arrangement and regulation of contemporary biochemical pathways can be measured. This paper presents an emerging evolutionary picture of aromatic amino acid biosynthesis within a large superfamily assemblage of prokaryotes that is sufficiently developed to illustrate a new perspective that will be applicable to many other biochemical pathways.      

Comparison of Four Horse Herpesviruses

Four equine herpesviruses (equine abortion virus, equine herpesvirus types 2 and 3, and equine cytomegalovirus) were compared. The equine abortion virus did not cross-neutralize with any of the other viruses, but the other three did show varying degrees of cross-neutralization among themselves. Equine abortion virus grew more quickly in tissue cultures than did the others, and attained higher titers of infectivity in the culture fluid; it also formed plaques in a wider range of tissue culture species, although the other three were not specific for one tissue culture system only, in that they would multiply in rabbit and cat kidney cultures. The densities of the deoxyribonucleic acids of all four viruses were in the range 1.716 to 1.717 g/ml (a guanine plus cytosine content of 57 to 58%). Taxonomic separation, as a distinct serotype, of equine abortion virus from the other herpesviruses seems to be justified. The other three are closely related to one another. They should perhaps be regarded as separate viruses and termed horse herpesviruses types 2, 3, and 4, although an alternative view would be to regard them as variants of a single virus type. The question of whether types 2, 3, and 4, or any other herpesviruses, should be placed in a phylogenetically distinct subgroup, known as cytomegaloviruses, is a moot point.     

The evolutionary history of the amylase multigene family in Drosophila pseudoobscura

In Drosophila pseudoobscura, the amylase (Amy) multigene family is contained within a series of inversions, or gene arrangements, on the third chromosome. The Standard (ST), Santa Cruz (SC), and Tree Line (TL) inversions are central to the phylogeny of arrangements, and have clusters of other arrangements derived from them. The gene arrangements belonging to each of these three clusters have a characteristic number of Amy genes, ranging from three in ST to two in SC to one in TL. This distribution pattern can reflect a history of either duplications or deletions, although the data available in the past did not permit a decision between these alternatives. We provide unambiguous evidence that three Amy genes were present before the divergence of the ST, SC, and TL arrangements. Thus, the current status of the Amy multigene family is the result of deletions in the TL and SC arrangements, which created three new pseudogenes: TL Amy2-psi, TL Amy3-psi, and SC Amy3- psi. Analysis of pseudogene sequences revealed that, in the SC and ST arrangements, pseudogene evolution has been retarded, most likely due to the homogenization effect of gene conversion. Finally, by determining the original copy number, we have reconstructed the evolutionary history of the Amy multigene family and linked it with the evolution of the central gene arrangements.      

Cortical Cytochrome Oxidase Activity Is Reduced in Alzheimer's Disease

Abstract: A defect in energy metabolism may play a role in the pathogenesis of neurodegenerative diseases, such as Alzheimer's disease. In the present study, we examined the activities of the enzymes that catalyze oxidative phosphorylation in frontal, temporal, parietal, and occipital cortex from Alzheimer's disease patients and age-matched controls. Complex I and complex II–III activities showed a small decrease in occipital cortex, but were unaffected in the other cortical areas. The most consistent change was a significant decrease of cytochrome oxidase (complex IV) activity of 25–30% in the four cortical regions examined. These results provide further evidence of a cytochrome oxidase defect in Alzheimer's disease postmortem brain tissue. A deficiency in this key energy-metabolizing enzyme could lead to a reduction in energy stores and thereby contribute to the neurodegenerative process.     

Age-Dependent Impairment of Mitochondrial Function in Primate Brain

Abstract: It has been hypothesized that some of the functional impairments associated with aging are the result of increasing oxidative damage to mitochondrial DNA that produces defects in oxidative phosphorylation. To test this hypothesis, we examined the enzymes that catalyze oxidative phosphorylation in crude mitochondrial preparations from frontoparietal cortex of 20 rhesus monkeys (5-34 years old). Samples were assayed for complex I, complex II-III, complex IV, complex V, and citrate synthase activities. When enzyme activities were corrected for citrate synthase activities (to account for variable degrees of mitochondrial enrichment), linear regression analysis demonstrated a significant negative correlation of the activities of complex I (p < 0.002) and complex IV (p < 0.03) with age but no significant change in complex II-III or complex V activities. Relative to animals 6.9 ± 0.9 years old (n = 7), the citrate synthase-corrected activity of complex I was reduced by 17% in animals 22.5 ± 0.9 years old (n = 6) (p < 0.05) and by 22% in animals 30.7 ± 0.9 years old (n = 7) (p < 0.01). Similar age-related reductions in the activities of complexes I and IV were obtained when enzyme activities were corrected for complex II-III activity. These findings show an age-associated progressive impairment of mitochondrial complex I and complex IV activities in cerebral cortices of primates.     

USE OF SENSORY EVALUATION FOR MEASURING DEODORIZING EFFECTS OF AN AIR CONDITIONER

The application of sensory methodology for measuring deodorizing effect of an air conditioner equipped with electric plasma was introduced. Deodorizing effect was measured using chemical and sensory methods at different time (0, 30 and 60 min) and mode (control, blowing and cooling) of an air conditioner. Smoke from a roll of cigarette in a closed room was used as a source of odor and the concentrations of acetic acid and ammonia were measured as odorous chemical components. As one of the sensory methods triangle test was used and as a first step to obtain deodorizing effects by triangle test, the threshold of each panelist was obtained as the log dilution ratio of odor concentration at which the difference from odorless air was detected. The odor concentration at each time and mode was calculated using the threshold of the panel and the deodorizing effect was obtained on the basis of the odor concentration. In addition to a triangle test, scaling methods such as category scaling or magnitude estimation were used to measure deodorizing effect of an air conditioner. Deodorizing effects by scaling methods were calculated based on odor intensity with time at each mode. The regression analysis was done between the efficacy of deodorizing effect by sensory test and those by acetic acid and ammonia, the R² values of the regression equations for triangle test, category scale, and magnitude estimation were 0.84, 0.72 and 0.69, respectively. Deodorizing effect by triangle test explained the decrease of acetic acid and ammonia better than those by category scaling or magnitude estimation while high cost and time consuming labor involved in triangle tests reduced the merit. The results of this study demonstrated that various sensory methods could be used to measure deodorizing effect of air conditioners and further researches on fast and reliable methods are needed to establish the official procedures.     

Health care rationing: the public's debate.

OBJECTIVE--To elicit the views of a large nationally representative sample of adults on priorities for health services. DESIGN--An interview survey based on a random sample of people aged 16 and over in Great Britain taken by the Office of Population Censuses and Surveys. SUBJECTS--The response rate to the survey was 75%, and the total number of adults interviewed was 2005. MAIN OUTCOME MEASURES--A priority ranking exercise of health services supplemented with attitude questions about priorities, who should set priorities, and budget allocation. RESULTS--The results of the main priority ranking exercise of 12 health services showed that the highest priority (rank 1) was accorded to "treatments for children with life threatening illness," the next highest priority (rank 2) was accorded to "special care and pain relief for people who are dying." The lowest priorities (11 and 12) were given to "treatment for infertility" and "treatment for people aged 75 and over with life threatening illness." Most respondents thought that surveys like this one should be used in the planning of health services. CONCLUSIONS--The public prioritise treatments specifically for younger rather than older people. There is some public support for people with self inflicted conditions (for example, through tobacco smoking) receiving lower priority for care, which raises ethical issues.