Complications and functional outcome following artificial anal sphincter implantation (Br J Surg 2002; 89: 877-881).
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Anal Canal↗
Biomedical subjects
J R Saunders
Publications and source records attributed to J R Saunders.
Complications and functional outcome following artificial anal sphincter implantation (Br J Surg 2002; 89: 877-881).
Explore the source record for details and available documents.
Anus Diseases↗
A promoter polymorphism in the gene encoding interleukin-12 p40 (IL12B) is associated with mortality from cerebral malaria and with reduced nitric oxide production.
Interleukin-12 (IL-12) is an important regulatory cytokine in infection and immunity. Administration of IL-12 may reduce complications of severe malaria in rodents. Polymorphisms in IL12B, the gene encoding the IL-12 p40 subunit, influence the secretion of IL-12 and susceptibility to Type 1 diabetes. We therefore investigated whether IL12B polymorphisms may affect the outcome of severe malaria. Homozygosity for a polymorphism in the IL12B promoter was associated with increased mortality in Tanzanian children having cerebral malaria but not in Kenyan children with severe malaria. Furthermore, homozygotes for the IL12B promotor polymorphism had decreased production of nitric oxide, which is in part regulated by IL-12 activity. These studies suggest that IL12B polymorphisms, via regulation of IL-12 production, may influence the outcome of malaria infection in at least one African population.
Animals↗
A comparison of ammonia-oxidiser populations in eutrophic and oligotrophic basins of a large freshwater lake.
A combination of PCR amplification and oligonucleotide probing was used to investigate the populations of ammonia-oxidisers of the beta-Proteobacteria in the eutrophic and oligotrophic basins of Lake Windermere, a large temperate lake in the English Lake District. Numbers of ammonia-oxidisers (MPN) in the Windermere lakewater were low (< 100 cells ml(-1)) throughout the year with the exception of peaks in August, which coincided with stratification, and November in the South Basin where overturn may have introduced ammonia-oxidising bacteria into the water column. Sediment samples contained larger populations of ammonia oxidisers, usually ca. 10(4) per g. dry weight, which remained relatively constant throughout the seasonal cycle in both Basins. DNA was recovered from lakewater and sediment samples and Nitrosospira and N. europaea-eutropha lineage 16S rRNA genes amplified in a nested PCR reaction, with confirmation of identity by oligonucleotide hybridisation. Nitrosospira 16S rDNA was readily detected in all samples and therefore found to be ubiquitous. In contrast, nitrosomonad DNA of the N. europaea-eutropha lineage could only be detected in the oligotrophic North Basin. Enrichment cultures of lakewater samples only exhibited nitrification at low (0.67 mM) and medium (5 mM) ammonium concentrations, whilst sediment enrichments nitrified at all concentrations tested including high (12.5 mM) ammonium medium. These data suggest that ammonia-oxidiser populations may be physiologically distinguished between lakewater and sediment, and that species distribution in a single lake is non-uniform.
Ammonia↗
(13)C incorporation into DNA as a means of identifying the active components of ammonia-oxidizer populations.
AIMS: To identify active CO2-assimilating species of ammonia-oxidizing bacteria in fresh water sediment. METHODS AND RESULTS: Enrichment cultures were incubated in the presence of 13C labelled CO2, and 13C-DNA successfully resolved from 12C-DNA by caesium chloride density gradient ultracentrifugation of DNA extracts. Ammonia-oxidizer DNA recovered from these gradients was amplified and characterised by Temporal Temperature Gradient Gel Electrophoresis (TTGE), with confirmatory sequence analysis to identify the metabolically active components of the population. CONCLUSION: The 12C-DNA fraction was dominated by nitrosospiras, in contrast to the 13C-DNA fraction which was largely nitrosomonad DNA, in support of the hypothesis that nitrosomonads out-compete nitrosospiras in laboratory culture. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of stable isotype incorporation into ammonia-oxidizer DNA could therefore circumvent the problems associated with RNA detection to identify metabolically active species in situ.
Carbon Dioxide↗
Flagellin gene sequence variation in the genus Pseudomonas.
Flagellin gene (fliC) sequences from 18 strains of Pseudomonas sensu stricto representing 8 different species, and 9 representative fliC sequences from other members of the gamma sub-division of proteobacteria, were compared. Analysis was performed on N-terminal, C-terminal and whole fliC sequences. The fliC analyses confirmed the inferred relationship between P. mendocina, P. oleovorans and P. aeruginosa based on 16S rRNA sequence comparisons. In addition, the analyses indicated that P. putida PRS2000 was closely related to P. fluorescens SBW25 and P. fluorescens NCIMB 9046T, but suggested that P. putida PaW8 and P. putida PRS2000 were more closely related to other Pseudomonas spp. than they were to each other. There were a number of inconsistencies in inferred evolutionary relationships between strains, depending on the analysis performed. In particular, whole flagellin gene comparisons often differed from those obtained using N- and C-terminal sequences. However, there were also inconsistencies between the terminal region analyses, suggesting that phylogenetic relationships inferred on the basis of fliC sequence should be treated with caution. Although the central domain of fliC is highly variable between Pseudomonas strains, there was evidence of sequence similarities between the central domains of different Pseudomonas fliC sequences. This indicates the possibility of recombination in the central domain of fliC genes within Pseudomonas species, and between these genes and those from other bacteria.
DNA, Bacterial↗
Plasmid transfer between Bacillus thuringiensis subsp. israelensis strains in laboratory culture, river water, and dipteran larvae.
Plasmid transfer between strains of Bacillus thuringiensis subsp. israelensis was studied under a range of environmentally relevant laboratory conditions in vitro, in river water, and in mosquito larvae. Mobilization of pBC16 was detected in vitro at a range of temperatures, pH values, and available water conditions, and the maximum transfer ratio was 10(-3) transconjugant per recipient under optimal conditions. Transfer of conjugative plasmid pXO16::Tn5401 was also detected under this range of conditions. However, a maximum transfer ratio of 1.0 transconjugant per recipient was attained, and every recipient became a transconjugant. In river water, transfer of pBC16 was not detected, probably as a result of the low transfer frequency for this plasmid and the formation of spores by the introduced donor and recipient strains. In contrast, transfer of plasmid pXO16::Tn5401 was detected in water, but at a lower transfer ratio (ca. 10(-2) transconjugant per donor). The number of transconjugants increased over the first 7 days, probably as a result of new transfer events between cells, since growth of both donor and recipient cells in water was not detected. Mobilization of pBC16 was not detected in killed mosquito larvae, but transfer of plasmid pXO16::Tn5401 was evident, with a maximum rate of 10(-3) transconjugant per donor. The reduced transfer rate in insects compared to broth cultures may be accounted for by competition from the background bacterial population present in the mosquito gut and diet or by the maintenance of a large population of B. thuringiensis spores in the insects.
Aedes↗
Lytic and lysogenic infection of diverse Escherichia coli and Shigella strains with a verocytotoxigenic bacteriophage.
A verocytotoxigenic bacteriophage isolated from a strain of enterohemorrhagic Escherichia coli O157, into which a kanamycin resistance gene (aph3) had been inserted to inactivate the verocytotoxin gene (vt2), was used to infect Enterobacteriaceae strains. A number of Shigella and E. coli strains were susceptible to lysogenic infection, and a smooth E. coli isolate (O107) was also susceptible to lytic infection. The lysogenized strains included different smooth E. coli serotypes of both human and animal origin, indicating that this bacteriophage has a substantial capacity to disseminate verocytotoxin genes. A novel indirect plaque assay utilizing an E. coli recA441 mutant in which phage-infected cells can enter only the lytic cycle, enabling detection of all infective phage, was developed.
Animals↗
Therapy of uncomplicated falciparum malaria: a randomized trial comparing artesunate plus sulfadoxine-pyrimethamine versus sulfadoxine-pyrimethamine alone in Irian Jaya, Indonesia.
Combining artesunate with existing antimalarial drugs may improve cure rates, delay emergence of resistance, and reduce transmission. We performed a randomized comparative trial to quantify the effect of adding artesunate to sulfadoxine-pyrimethamine in the treatment of uncomplicated falciparum malaria in Indonesia. Using a modified 1997 World Health Organization protocol for assessment of therapeutic efficacy of antimalarial drugs, 105 patients (stratified by age/ethnic group) were randomized: 53 received artesunate orally, 4 mg/kg of body weight, a single daily dose for three days, plus sulfadoxine-pyrimethamine orally (1.25 mg of pyrimethamine/kg of body weight), a single dose on day 0, and 52 patients received sulfadoxine-pyrimethamine alone. Six from the combination group were withdrawn from analysis, as were six of the sulfadoxine-pyrimethamine group. Treatment failure rates on day 14 were 0% in the artesunate plus sulfadoxine-pyrimethamine group and 8.7% in the sulfadoxine-pyrimethamine group (P = 0.12). Treatment failure rates on day 28 were 4.4% and 15.2%, respectively (P = 0.16). Relative risk of treatment failure at 28 days was 0.3 (95% confidence interval [CI] = 0.1-1.3). Mean fever clearance time (1.3 versus 1.7 days) and mean parasite clearance time (1.4 versus 2.0 days) were both faster in the artesunate plus sulfadoxine-pyrimethamine group than in the sulfadoxine-pyrimethamine group (P = 0.08 and P < 0.0001, respectively). Only 20 (39.2%) of 51 patients treated with artesunate plus sulfadoxine-pyrimethamine were still parasitemic on day 1 compared with 45 (86.5%) of 52 patients treated with sulfadoxine-pyrimethamine alone (P = 0.000001, relative risk [RR] = 0.4, 95% CI = 0.3-0.6). Gametocyte carriage was lower following artesunate plus sulfadoxine-pyrimethamine than following sulfadoxine-pyrimethamine (RR = 0.5, 95% CI = 0.2-1.0 on day 7 and RR = 0.5, 95% CI = 0.2-1.1 on day 14). Mild diarrhea, rash, and itching resolved without treatment. Combined artesunate plus sulfadoxine-pyrimethamine resulted in more rapid fever and parasiteclearance, was well tolerated, reduced risk of treatment failure, and lowered gametocyte carriage.
Administration, Oral↗
Synchronous perforation of a Meckel's diverticulum and a duodenal ulcer.
Dual perforation of the gastrointestinal tract is rare. We present a case of a patient who presented with a simultaneous perforation of a Meckel's diverticulum and a duodenal ulcer.
Adult↗
Combined molecular ecological and confocal laser scanning microscopic analysis of peat bog methanogen populations.
Confocal laser scanning microscopy, using fluorescently labelled oligonucleotide probes targeting the 16S rRNA of different physiological groups of methanogens, was used to identify which methanogenic genera were present and to describe their in situ spatial locations in samples taken at different depths from blanket peat bog cores. Total bacterial DNA was also extracted and purified from the samples and used as template for amplification of 16S rRNA and regions of methyl CoM reductase-encoding genes using the polymerase chain reaction, as well as for oligonucleotide hybridisation experiments. These techniques, used in concert, demonstrated that methanogens of several physiological groups were present in highest numbers in the mid regions of 25 cm deep peat cores. Some discrepancies were apparent in the findings of the microscopic and molecular methods, though these may be partially accounted for by the different sensitivities of the techniques employed. The combined approaches used in this study gave an insight into the diversity and distribution of methanogens in peat environments not possible using molecular ecological methods alone.
DNA, Archaeal↗
Development and application of molecular tools in the study of IncN-related plasmids from lakewater sediments.
Homology to IncN, P, Q and W inc regions was investigated amongst 114 Hg(2+)-resistant or antibiotic-resistant bacteria isolated from lakewater sediments. No hybridisation signals were found with Inc P, Q and W probes, and only one plasmid, pLV1402, hybridised to the IncN probe. PCR primers designed to conserved regions in the replicon of the IncN plasmid pCU1 and the related beta replicon from pGSH500 were used to amplify a 978-bp fragment from pLV1402, with sequence analysis showing a close relationship (99.2% identity) between their replication genes. A 387-bp region from the pLV1402 rep gene was used to re-screen the isolates and identified another related plasmid, pLV1403. A 3.7-kb probe containing the alpha replicon from pGSH500 hybridised to both pLV1402 and pLV1403, suggesting that both are multi-replicon plasmids. The PCR primers and probes described will be useful in future studies of plasmid diversity.
Bacteria↗
Analysis of ammonia-oxidizing bacteria populations in acid forest soil during conditions of moisture limitation.
Ammonia-oxidizer numbers decreased under conditions of moisture limitation in litter, fermentation and humus layers of forest soil in the field, but the extent of regrowth after rehydration varied between layers. Nitrosospira 16S rRNA genes were amplified from all layers, regardless of moisture content or soil pH which varied between 4.1 and 5.2. Nitrosomonas spp. were detected less often, but appeared to exhibit more rapid recovery than the Nitrosospira spp. when drought conditions were relieved by rainfall.
Ammonia↗
Plasmid transfer between the Bacillus thuringiensis subspecies kurstaki and tenebrionis in laboratory culture and soil and in lepidopteran and coleopteran larvae.
Plasmid transfer between Bacillus thuringiensis subsp. kurstaki HD1 and B. thuringiensis subsp. tenebrionis donor strains and a streptomycin-resistant B. thuringiensis subsp. kurstaki recipient was studied under environmentally relevant laboratory conditions in vitro, in soil, and in insects. Plasmid transfer was detected in vitro at temperatures of 5 to 37 degrees C, at pH 5.9 to 9.0, and at water activities of 0.965 to 0.995, and the highest transfer ratios (up to 10(-1) transconjugant/donor) were detected within 4 h. In contrast, no plasmid transfer was detected in nonsterile soil, and rapid formation of spores by the introduced strains probably contributed most to the lack of plasmid transfer observed. When a B. thuringiensis subsp. kurstaki strain was used as the donor strain, plasmid transfer was detected in killed susceptible lepidopteran insect (Lacanobia oleracea) larvae but not in the nonsusceptible coleopteran insect Phaedon chocleriae. When a B. thuringiensis subsp. tenerbrionis strain was used as the donor strain, no plasmid transfer was detected in either of these insects even when they were killed. These results show that in larger susceptible lepidopteran insects there is a greater opportunity for growth of B. thuringiensis strains, and this finding, combined with decreased competition due to a low initial background bacterial population, can provide suitable conditions for efficient plasmid transfer in the environment.
Animals↗
Phylogenetic differentiation of two closely related Nitrosomonas spp. That inhabit different sediment environments in an oligotrophic freshwater lake.
The population of ammonia-oxidizing bacteria in a temperate oligotrophic freshwater lake was analyzed by recovering 16S ribosomal DNA (rDNA) from lakewater and sediment samples taken throughout a seasonal cycle. Nitrosospira and Nitrosomonas 16S rRNA genes were amplified in a nested PCR, and the identity of the products was confirmed by oligonucleotide hybridization. Nitrosospira DNA was readily identified in all samples, and nitrosomonad DNA of the Nitrosomonas europaea-Nitrosomonas eutropha lineage was also directly detected, but during the summer months only. Phylogenetic delineation with partial (345 bp) 16S rRNA gene sequences of clones obtained from sediments confirmed the fidelity of the amplified nitrosomonad DNA and identified two sequence clusters closely related to either N. europaea or N. eutropha that were equated with the littoral and profundal sediment sites, respectively. Determination of 701-bp sequences for 16S rDNA clones representing each cluster confirmed this delineation. A PCR-restriction fragment length polymorphism (RFLP) system was developed that enabled identification of clones containing N. europaea and N. eutropha 16S rDNA sequences, including subclasses therein. It proved possible to analyze 16S rDNA amplified directly from sediment samples to determine the relative abundance of each species compared with that of the other. N. europaea and N. eutropha are very closely related, and direct evidence for their presence in lake systems is limited. The correlation of each species with a distinct spatial location in sediment is an unusual example of niche adaptation by two genotypically similar bacteria. Their occurrence and relative distribution can now be routinely monitored in relation to environmental variation by the application of PCR-RFLP analysis.
Cloning, Molecular↗
Comparison of flagellin genes from clinical and environmental Pseudomonas aeruginosa isolates.
Pseudomonas aeruginosa, an important opportunistic pathogen, was isolated from environmental samples and compared to clinically derived strains. While P. aeruginosa was isolated readily from an experimental mushroom-growing unit, it was found only rarely in other environmental samples. A flagellin gene PCR-restriction fragment length polymorphism analysis of the isolates revealed that environmental and clinical P. aeruginosa strains are not readily distinguishable. The variation in the central regions of the flagellin genes of seven of the isolates was investigated further. The strains used included two strains with type a genes (998 bp), four strains with type b genes (1,258 bp), and one strain, K979, with a novel flagellin gene (2,199 bp). The route by which flagellin gene variation has occurred in P. aeruginosa is discussed.
Agaricales↗
Gamma probe-directed biopsy of the sentinel node in oral squamous cell carcinoma.
OBJECTIVE: Management of the N0 neck in head and neck squamous cell carcinoma is an important issue for the head and neck surgeon. Experience with radionuclide-labeled colloid injection to identify a sentinel node in malignant melanoma suggests a high level of accuracy for this approach to identify microscopic metastasis when present. We set out to explore the feasibility of using the handheld gamma probe to identify radiolabeled sentinel nodes in oral squamous cell carcinoma. PATIENT POPULATION: Five individuals with N0 necks and accessible oral or oropharyngeal primary sites from a major tertiary referral center. METHODS: Radiolabel with unfiltered technetium Tc 99m sulfur colloid was injected in quadrants around the primary site followed by immediate dynamic lymphoscintigraphy. Open biopsy of the sentinel node was accomplished within 2 hours of injection after extirpation of the primary site. Regional or complete neck dissection was performed after sentinel node biopsy. RESULTS: Sentinel node biopsy accurately identified one or several nodes in 2 cases, including nodes containing metastatic cancer in 1. In the other 3 cases, the radiolabel failed to identify the sentinel node despite the presence of metastatic disease in the nodes at final pathologic study in 2. CONCLUSIONS: Detection and biopsy of the sentinel node are feasible for selected patients with oral head and neck squamous cell carcinoma with N0 necks. There is a potential savings of time, cost, and morbidity with this approach. However, several substantial problems were encountered with the technique in this limited series of patients. Establishing the reliability of lymphoscintigraphy in this setting would require testing in a much larger patient cohort. Our experience suggests that such an investment may not be warranted.
Adult↗
The genetic basis of head and neck carcinoma.
Research over the past few years has pointed to a genetic basis for numerous cancers. Efforts in this regard are ongoing in squamous carcinoma of the head and neck. Today surgeons and residents in training need to stay up to date on molecular biology and the genetic sequences that are necessary to form a malignancy. In addition, these changes offer diagnosticians and therapists novel ways both to diagnose and treat malignancies. An evolution in molecular genetics, tumor virology, and tumor biology has led to our understanding of how malignancies arise. There are two pathways of cancer production: the activation of an oncogene or the mutation of a tumor suppressor gene. This review discusses the interaction of these genetic changes in the development of squamous carcinoma of the head and neck, their relationship to tobacco and alcohol use, as well as methods to detect the presence of malignancy and novel techniques that may be used to treat malignancies in the future.
Alcohol Drinking↗