Search PubMed⌕ Search

Biomedical subjects

D J Lane

Publications and source records attributed to D J Lane.

At least 37 records · Page 2Linked to original sources
PubMed1990

The excision of intervening sequences from Salmonella 23S ribosomal RNA.

Novel, approximately 90 bp intervening sequences (IVs) were discovered within the 23S rRNA genes of S. typhimurium and S. arizonae. These non-rRNA sequences are transcribed and then excised during rRNA maturation. The rRNA fragments that result from the excision of the extra sequences are not religated. This results in fragmented 23S rRNAs. The excision of one IVS was shown to be catalyzed in vivo and in vitro by ribonuclease III. These IVSs are highly volatile evolutionarily, sometimes occurring in only some of the multiple rRNA operons of a particular cell. The sporadic nature of the occurrence of fragmented rRNAs among closely related organisms argues that such fragmentation is a derived state, not a primitive one. Possible sources of these IVSs, their parallels with internal transcribed spacers and introns in eukaryotes, and their possible roles in the evolutionary process are discussed.

Base Sequence↗
PubMed1990

Ear involvement in the yellow nail syndrome.

Recognized features of the yellow nail syndrome include yellow nails, lymphedema, and pleural effusions. We report a patient with the additional feature of keratosis obturans, which may be a manifestation of this syndrome in the external ear.

Ear Canal↗
PubMed1990

Breathing muscle activity during expiration in patients with chronic airflow obstruction.

During quiet ventilation in 10 patients with severe chronic airflow obstruction (AFO) there were large tidal swings of pleural pressure, 15.8 +/- 5.1 cmH2O, with high negative pressures achieved, 15.2 +/- 5.2 cmH2O. The pattern of pleural pressure mirrored that of tidal expiratory flow with a rapid rise to maximum of pleural pressure and flow at the beginning of expiration, a slow decline of both throughout most of expiration, and just before the onset of inspiration at flow reversal, a sharp fall in pleural pressure and expiratory flow. The shape of expiratory flow and pleural pressure tracings and the pattern of EMG recordings are compatible with loss of post-inspiratory muscle braking of flow. The generally negative pleural pressure and the EMG silence during expiration indicated relaxation of expiratory muscles throughout expiration. Extrapolation of the tidal expiratory flow curve to zero, and calculation of the area under the extrapolated curve showed the volume of dynamic hyperinflation to be a small proportion of the total increase in functional residual capacity above the predicted value in these patients.

Adult↗
PubMed1988

Molecular phylogeny of the animal kingdom.

A rapid sequencing method for ribosomal RNA was applied to the resolution of evolutionary relationships among Metazoa. Representatives of 22 classes in 10 animal phyla were used to infer phylogenetic relationships, based on evolutionary distances determined from pairwise comparisons of the 18S ribosomal RNA sequences. The classical Eumetazoa are divided into two groups. Cnidarians arose from a protist ancestry different from the second group, the Bilateria. Within the Bilateria, an early split gave rise to Platyhelminthes (flatworms) and the coelomate lineage. Coelomates are thus monophyletic, and they radiated rapidly into four groups: chordates, echinoderms, arthropods, and eucoelomate protostomes.

Animals↗
PubMed1988

Pulmonary tuberculosis in Behçet's syndrome.

Pulmonary tuberculosis has rarely been recorded in patients with Behçet's syndrome, but to date no report has convincingly demonstrated any possible association between these two diseases. We describe three cases of pulmonary tuberculosis in patients with Behcet's syndrome and discuss the possible underlying mechanisms.

Adult↗
PubMed1988

Sulfur-oxidizing bacterial endosymbionts: analysis of phylogeny and specificity by 16S rRNA sequences.

The 16S rRNAs from the bacterial endosymbionts of six marine invertebrates from diverse environments were isolated and partially sequenced. These symbionts included the trophosome symbiont of Riftia pachyptila, the gill symbionts of Calyptogena magnifica and Bathymodiolus thermophilus (from deep-sea hydrothermal vents), and the gill symbionts of Lucinoma annulata, Lucinoma aequizonata, and Codakia orbicularis (from relatively shallow coastal environments). Only one type of bacterial 16S rRNA was detected in each symbiosis. Using nucleotide sequence comparisons, we showed that each of the bacterial symbionts is distinct from the others and that all fall within a limited domain of the gamma subdivision of the purple bacteria (one of the major eubacterial divisions previously defined by 16S rRNA analysis [C. R. Woese, Microbiol. Rev. 51: 221-271, 1987]). Two host specimens were analyzed in five of the symbioses; in each case, identical bacterial rRNA sequences were obtained from conspecific host specimens. These data indicate that the symbioses examined are species specific and that the symbiont species are unique to and invariant within their respective host species.

Animals↗
PubMed1988

Evolutionary relationships among cyanobacteria and green chloroplasts.

The 16S rRNAs from 29 cyanobacteria and the cyanelle of the phytoflagellate Cyanophora paradoxa were partially sequenced by a dideoxynucleotide-terminated, primer extension method. A least-squares distance matrix analysis was used to infer phylogenetic trees that include green chloroplasts (those of euglenoids, green algae, and higher plants). The results indicate that many diverse forms of cyanobacteria diverged within a short span of evolutionary distance. Evolutionary depth within the surveyed cyanobacteria is substantially less than that separating the major eubacterial taxa, as though cyanobacterial diversification occurred significantly after the appearance of the major eubacterial groups. Three of the five taxonomic sections defined by Rippka et al. (R. Rippka, J. Deruelles, J. B. Waterbury, M. Herdman, and R. Y. Stanier, J. Gen. Microbiol. 111:1-61, 1979) (sections II [pleurocapsalean], IV [heterocystous, filamentous, nonbranching], and V [heterocystous, filamentous, branching]) are phylogenetically coherent. However, the other two sections (I [unicellular] and III [nonheterocystous, filamentous]) are intermixed and hence are not natural groupings. Our results not only support the conclusion of previous workers that the cyanobacteria and green chloroplasts form a coherent phylogenetic group but also suggest that the chloroplast lineage, which includes the cyanelle of C. paradoxa, is not just a sister group to the free-living forms but rather is contained within the cyanobacterial radiation.

Base Sequence↗
PubMed1988

Should ipratropium bromide be added to beta-agonists in treatment of acute severe asthma?

In a double-blind randomized trial, 40 patients with acute severe asthma were given either nebulized salbutamol, 5 mg, or salbutamol, 5 mg mixed with ipratropium bromide 500 micrograms, on admission to hospital and again two hours later. There was no significant difference between the mean peak flows of the two treatment groups at any time. However, two hours after each treatment, there were fewer subjects in the ipratropium and salbutamol group whose peak flow rates had fallen back toward baseline levels than in the salbutamol only treatment group. Thus, although ipratropium did not improve the overall maximal bronchodilator response, it may have prolonged the duration of the response, which would be a clinically useful effect.

Acute Disease↗
PubMed1987

Campylobacter pylori, the spiral bacterium associated with human gastritis, is not a true Campylobacter sp.

Comparison of partial 16S rRNA sequences from representative Campylobacter species indicates that the Campylobacter species form a previously undescribed basic eubacterial group, which is related to the other major groups only by very deep branching. This analysis was extended to include the spiral bacterium associated with human gastritis, Campylobacter pylori (formerly Campylobacter pyloridis). The distance between C. pylori and the other Campylobacter species is sufficient to exclude the pyloric organism from the Campylobacter genus. The results indicate that C. pylori is more closely related to Wolinella succinogenes than it is to the other Campylobacter species inspected. Another close relative of the campylobacters was found to be Thiovulum, a sulfide-dependent marine bacterium.

Base Sequence↗
PubMed1987

Trial of ketoconazole in non-invasive pulmonary aspergillosis.

A one year study of the efficacy of the antifungal agent ketoconazole in non-invasive pulmonary aspergillosis was carried out. Ten patients, seven with allergic bronchopulmonary aspergillosis and three with mycetoma, were studied. They were randomly allocated to receive 400 mg daily or placebo orally in a double blind fashion. In the treated group (n = 6), concentrations of serum IgG specific for Aspergillus fumigatus fell significantly during treatment (mean reduction 42% (SEM 2.2%) compared with determinations preceding the study). This effect was evident by three months and continued for the 12 months of treatment. Patients receiving placebo (n = 4) showed no significant change in serum IgG concentration (mean change + 10% (SEM 5.3%]. Asthmatic patients treated with ketoconazole (n = 4) had significantly lower symptom scores than those receiving placebo (n = 3) (+0.45%/month (SEM 6.9%) versus +27%/month (SEM 6.5%); p less than 0.001). None of the patients treated with ketoconazole reported any adverse effects. Ketoconazole may cause serious liver damage but its use may be justified in bronchopulmonary aspergillosis if further experience confirms its ability to alter the course of a potentially serious disease.

Adult↗
PubMed1985

Rapid determination of 16S ribosomal RNA sequences for phylogenetic analyses.

Although the applicability of small subunit ribosomal RNA (16S rRNA) sequences for bacterial classification is now well accepted, the general use of these molecules has been hindered by the technical difficulty of obtaining their sequences. A protocol is described for rapidly generating large blocks of 16S rRNA sequence data without isolation of the 16S rRNA or cloning of its gene. The 16S rRNA in bulk cellular RNA preparations is selectively targeted for dideoxynucleotide-terminated sequencing by using reverse transcriptase and synthetic oligodeoxynucleotide primers complementary to universally conserved 16S rRNA sequences. Three particularly useful priming sites, which provide access to the three major 16S rRNA structural domains, routinely yield 800-1000 nucleotides of 16S rRNA sequence. The method is evaluated with respect to accuracy, sensitivity to modified nucleotides in the template RNA, and phylogenetic usefulness, by examination of several 16S rRNAs whose gene sequences are known. The relative simplicity of this approach should facilitate a rapid expansion of the 16S rRNA sequence collection available for phylogenetic analyses.

Animals↗
PubMed1985

Characterization of a Yellowstone hot spring microbial community by 5S rRNA sequences.

The microorganisms inhabiting a 91 degrees C hot spring in Yellowstone National Park were characterized by sequencing 5S rRNAs isolated from the mixed, natural microflora without cultivation. By comparisons of these sequences with reference sequences, the phylogenetic relationships of the hot spring organisms to better characterized ones were established. Quantitation of the total 5S-sized rRNAs revealed a complex microbial community of three dominant members, a predominant archaebacterium affiliated with the sulfur-metabolizing (dependent) branch of the archaebacteria, and two eubacteria distantly related to Thermus spp. The archaebacterial and the eubacterial 5S rRNAs each constituted about half the examined population.

Archaea↗
PubMed1985

Phylogenetic analysis of the genera Thiobacillus and Thiomicrospira by 5S rRNA sequences.

5S rRNA nucleotide sequences from Thiobacillus neapolitanus, Thiobacillus ferrooxidans, Thiobacillus thiooxidans, Thiobacillus intermedius, Thiobacillus perometabolis, Thiobacillus thioparus, Thiobacillus versutus, Thiobacillus novellus, Thiobacillus acidophilus, Thiomicrospira pelophila, Thiomicrospira sp. strain L-12, and Acidiphilium cryptum were determined. A phylogenetic tree, based upon comparison of these and other related 5S rRNA sequences, is presented. The results place the thiobacilli, Thiomicrospira spp., and Acidiphilium spp. in the "purple photosynthetic" bacterial grouping which also includes the enteric, vibrio, pseudomonad, and other familiar eubacterial groups in addition to the purple photosynthetic bacteria. The genus Thiobacillus is not an evolutionarily coherent grouping but rather spans the full breadth of the purple photosynthetic bacteria.

Base Sequence↗