Nuclear DNA analysis of koilocytic and premalignant lesions of the uterine cervix.

Cervical biopsy samples were taken from 79 patients who had various grades of cervical intraepithelial neoplasia or who showed evidence, in the form of koilocytosis, of human papillomavirus infection of the uterine cervix and from 10 women with normal cervices. The DNA content of the cells in the samples was analysed by flow cytometry. Analysis of the data obtained showed that the biopsy samples from women with cervical intraepithelial neoplasia and human papillomavirus lesions contained significantly more dividing cells (31.2% of cells from human papillomavirus lesions with no cervical intraepithelial neoplasia and 33.06%, 29.89%, and 31.76% of cells from cervical intraepithelial neoplasia grades I, II, and III, respectively) than those from women with normal cervices (21.6%). The proportion of aneuploid samples from the group who showed evidence of human papillomavirus infection only (18.2%) did not differ significantly from the group with cervical intraepithelial neoplasia grade III (21.2%). Aneuploidy and an increased rate of cellular proliferation are recognised characteristics of malignancy. These results therefore support the view that human papillomavirus plays an important part in the aetiology of cervical carcinoma and are relevant to the clinical management of patients.     

Use of carbon dioxide and natural or synthetic aggregation-attachment pheromone of the bont tick,Amblyomma hebraeum,to attract and trap unfed adults in the field

It was determined previously that unfed adults ofAmblyomma hebraeum become active in response to carbon dioxide but are not attracted by it. We have now shown in field experiments that males and females which are activated by carbon dioxide are attracted to the aggregation-attachment pheromone produced by males after a period of feeding on the host. Unfed adults were attracted too-nitrophenol, a component of the aggregation-attachment pheromone ofAmblyomma variegatum, pre-fed males ofA. hebraeum, and extracts of such males. Live males were more attractive than the extracts which, in turn, were more attractive thano-nitrophenol. The ticks were attracted to sources ofo-nitrophenol from as far away as 11 m in 90 min. Simple traps, baited with carbon dioxide and aggregation-attachment pheromone (from pre-fed males or extracts of pre-fed males), were used to capture unfed adults that had been released in the field. The response of unfed adults to carbon dioxide and the aggregation-attachment pheromone presents an obvious host-location mechanism and a means for the ticks to discriminate between suitable hosts (those with males already attached) and potentially unsuitable hosts (those with no males attached).     

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.      

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.      

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.      

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.     

Responses of the ticksAmblyomma hebraeum andA. variegatum to known or potential components of the aggregation-attachment pheromone. III. Aggregation

Ten known or potential components of the aggregation-attachment pheromone (AAP) of the ticksAmblyomma hebraeum andA. variegatum, as well as mixtures of these components, extracts of prefed males and live prefed males, were tested as aggregation stimulants. In field assays, laboratory-reared unfed male and female ticks were released 20 cm downwind of CO₂/pheromone release sites; the numbers of ticks that aggregated at the release sites were recorded after 30 min. InA. variegatum, aggregation was induced by methyl salicylate,o-nitrophenol, 2,6-dichlorophenol, phenylacetaldehyde and some mixtures containing these compounds; a strong aggregation response was induced by an extract of five prefed malesA. variegatum and a weak response was induced by an extract of 50 prefed males ofA. hebraeum. InA. hebraeum, aggregation was induced by phenylacetaldehyde, mixtures of compounds that included phenylacetaldehyde, extracts of 50 prefed males ofA. hebraeum orA. variegatum and 50 live prefed males ofA. hebraeum. InA. variegatum, aggregation was inhibited if compounds that do not occur naturally in the AAP of the species were included in mixtures. InA. hebraeum, phenylacetaldehyde appeared to act as an arrestant for ticks that had been attracted to release sites by other compounds.     

A comparison of the attraction of nymphs and adults of the ticksAmblyomma hebraeum andA. variegatum to carbon dioxide and the male-produced aggregation-attachment pheromone

The attraction of nymphs of the ticksAmblyomma hebraeum andA. variegatum to CO₂ alone and CO₂ together with the male-produced aggregation-attachment pheromone (AAP) was investigated. Matching experiments on the attraction of the adults of the two species were run for comparison. Nymphs ofA. hebraeum were strongly attracted to sources of CO₂ and CO₂/AAP at distances of 10 and 15 m. At distances of 20 and 25 m significantly more nymphs were attracted to CO₂/AAP than to CO₂ alone. Adults ofA. hebraeum were not attracted to CO₂ alone at any distance; these ticks were attracted to CO₂ and AAP together for distances of up to 25 m. The patterns of attraction of nymphs and adults ofA. variegatum at 10 m were similar to those recorded inA. hebraeum.     

Comparison of the attachment rates of males of the ticksAmblyomma hebraeum andA. variegatum to cattle,sheep and rabbits in the absence of aggregation-attachment pheromone

Losses in domestic ruminants caused by heartwater (Cowdria ruminantium infection) in Zimbabwe and Mozambique are greater when the vector isAmblyomma hebraeum than when the vector isA. variegatum. It has been suggested that the epidemiology of the disease may be influenced by the rates at which unfed adults of these two tick species attach to uninfested hosts (i.e. in the absence of the male-produced aggregation-attachment pheromone [AAP]). In this study we confined unfed males ofA. hebraeum andA. variegatum on uninfested cattle, sheep and rabbits and recorded their attachment rates. Males of both species attached more rapidly on cattle than on sheep or rabbits. Males ofA. hebraeum attached more rapidly than males ofA. variegatum on all three host species. The differences in the attachment rates between the two species were much greater on sheep and rabbits than on cattle. The findings suggest that in the absence of AAP, pioneer males of both tick species may attach to cattle, and pioneer males ofA. hebraeum may also attach to sheep. The differences in the attachment rates ofA. hebraeum andA. variegatum provide a possible explanation for observed differences in the epidemiology of heartwater associated with these two vector species.