Phylogenetic relationships of three rockfish: Sebastesmelanops, Sebastesciliatus and Sebastesvariabilis (Scorpaeniformes, Scorpaenidae) based on complete mitochondrial genome sequences.

We characterise the complete mitochondrial genomes (mitogenomes) of Black rockfish (Sebastesmelanops Girard, 1856; n = 1), Dark rockfish (Sebastesciliatus Tilesius, 1813; n = 2) and Dusky rockfish (Sebastesvariabilis Pallas, 1814; n = 2). The lengths of the mitogenomes are 16,405 bp for S.melanops, 16,400 bp for both S.ciliatus and 16,400 and 16,401 bp for S.variabilis. We examine these species' phylogenetic relationships using 35 previously published rockfish mitogenomes, representing 27 species. We find that S.melanops is sister to a clade consisting of S.rubrivinctus, S.nigrocinctus, S.umbrosus and S.oculatus, whereas S.ciliatus and S.variabilis are sister to a clade consisting of S.norvegicus, S.viviparus, S.mentella and S.fasciatus. We were unable to separate S.ciliatus and S.variabilis using their complete mitogenomes.

Study protocol for a multicenter prospective cohort study on esophagogastric anastomoses and anastomotic leak (the Oesophago-Gastric Anastomosis Audit/OGAA).

Esophagectomy is a mainstay in curative treatment for esophageal cancer; however, the reported techniques and outcomes can vary greatly. Thirty-day mortality of patients with an intact anastomosis is 2-3% as compared to 17-35% in patients who have an anastomotic leak. The subsequent management of leaks postesophagectomy has great global variability with little consensus on a gold standard of practice. The aim of this multicentre prospective audit is to analyze current techniques of esophagogastric anastomosis to determine the effect on the anastomotic leak rate. Leak rates and leak management will be assessed to determine their impact on patient outcomes. A 12-month international multicentre prospective audit started in April 2018 and is coordinated by a team from the West Midlands Research Collaborative. This will include patients undergoing esophagectomy over 9 months and encompassing a 90-day follow-up period. A pilot data collection period occurred at four UK centers in 2017 to trial the data collection form. The audit standards will include anastomotic leak and the conduit necrosis rate should be less than 13% and major postoperative morbidity (Clavien-Dindo Grade III or more) should be less than 35%. The 30-day mortality rate should be less than 5% and the 90-day mortality rate should be less than 8%. This will be a trainee-led international audit of esophagectomy practice. Key support will be given by consultant colleagues and anesthetists. Individualized unit data will be distributed to the respective contributing sites. An overall anonymized report will be made available to contributing units. Results of the audit will be published in peer-reviewed journals with all collaborators fully acknowledged. The key information and results from the audit will be disseminated at relevant scientific meetings.

Rangewide molecular structuring in the Utah sucker (Catostomus ardens).

The Utah sucker (Catostomus ardens) is endemic to the Bonneville Basin and the upper Snake River drainage in western North America, and is thought to hybridize with the federally endangered June sucker (Chasmistes liorus mictus) in Utah Lake (Bonneville Basin). Here we describe the discovery of a major subdivision in Utah suckers (4.5% mitochondrial sequence divergence) between the ancient Snake River drainage and the Bonneville Basin. This boundary has not previously been recognized in Utah suckers based on morphologic variation, but has been recently described in two endemic cyprinids in the region. Populations in valleys east of the Wasatch Mountains in Utah clustered with the Snake River populations, suggesting that these valleys may have had an ancient hydrologic connection to the Snake River. We also found evidence of population isolation within the Bonneville Basin, corresponding to two Pleistocene sub-basins of the ancient Lake Bonneville. In contrast, we found no molecular evidence for deep divergence between Utah suckers and June suckers in Utah Lake or for a history of hybridization between divergent lineages in that population, although we recognize that demographic events may have obscured this signal. These findings suggest that the morphological differences between Utah and June suckers in Utah Lake may be the result of strong, and relatively recent, ecological selection. In summary, morphological and molecular characters seem to vary along different axes in different portions of the range of this taxon, providing an interesting system for studying the contributions of neutral and adaptive variation to species diversity.

Isolation and characterization of type I antifreeze proteins from Atlantic snailfish (Liparis atlanticus) and dusky snailfish (Liparis gibbus).

Antifreeze proteins (AFPs) were isolated from the blood plasma of Atlantic snailfish Liparis atlanticus and dusky snailfish Liparis gibbus, which belong to the Teleost family Cyclopteridae, a close relative of sculpins. Using a combination of gel filtration chromatography and reversed-phase HPLC, proteins were purified to individual peaks. Atlantic snailfish plasma contained two different proteins (MW=9344, 9415) while dusky snailfish plasma contained five protein isoforms (MW=9514-9814), as determined by mass spectrometry. Further characterization revealed that these proteins are rich in alanine (>50 mol%), and have alpha-helical secondary structure that can undergo reversible thermal denaturation. Thermal hysteresis activities of these proteins were similar to each other but lower than the major type I AFPs from winter flounder. Results of this study have indicated that although the AFPs from snailfish are significantly larger than previously described type I AFPs, they share enough characteristics to be classified in this group.

Visualization of bacterial glycocalyx with a scanning electron microscope.

Using a new technique for scanning electron microscopic preparation, bacterial glycocalyx is seen in its natural, highly hydrated state for the first time. Visual images of the glycocalyx obtained from these preparations are a marked departure from the visual images of glycocalyx obtained previously with conventional scanning electron microscopic analysis. The dominating presence of glycocalyx visualized in its naturally hydrated state gives credence to the role of bacterial glycocalyx as a mechanical barrier to host defenses and antibiotics and supports the role of glycocalyx as a significant factor in bacterial virulence.

Characterization of a rabbit model of staphylococcal osteomyelitis.

We previously described a rabbit osteomyelitis model that involved the direct introduction of Staphylococcus aureus into devascularized bone. To further evaluate the model, we performed experiments aimed at correlating the microbiological, radiographic, and histologic parameters involved in the development of experimental osteomyelitis. Using the strain UAMS-1, we achieved an infection rate of 75% with an inoculum as small as 2 x 10(3) colony-forming units. However, development of significant radiographic and histologic signs of disease required an inoculum of at least 2 x 10(4) colony-forming units. Radiographic signs were minimal 1 week after infection and progressed steadily to a maximum 3 weeks after infection. In contrast, histologic signs of disease were observed within 1 week and remained essentially unchanged throughout the 4-week evaluation period. Unlike the results obtained with UAMS-1, rabbits infected with the heavily encapsulated Staphylococcus aureus strain Smith diffuse exhibited little evidence of disease even when infected with 2 x 10(6) colony-forming units. The reduced virulence of strain Smith diffuse was surprising given its greatly enhanced virulence (relative to UAMS-1) in a murine peritonitis model of staphylococcal disease. These results suggest that UAMS-1 expresses virulence factors that are important in the pathogenesis of osteomyelitis and that some or all of these virulence factors are either absent or are not expressed in strain Smith diffuse. Most importantly, the results suggest that our model may be appropriate for the identification and characterization of these virulence factors.

Prophylaxis against infection in total joint arthroplasty. One day of cefuroxime compared with three days of cefazolin.

The efficacy of cefuroxime was compared with the efficacy of cefazolin for prophylaxis against postoperative wound infection in a prospective, double-blind, multicenter study of 1354 patients who had had elective primary or revision total hip or knee arthroplasty. The patients were randomly assigned to receive either 1.5 grams of cefuroxime followed by 750 milligrams eight and sixteen hours later (for a total of one day of antibiotic treatment), or one gram of cefazolin every eight hours for nine doses (for a total of three days of antibiotic treatment). The first dose of each drug was administered fifteen to sixty minutes before the operative incision was made (for a primary operation) or after tissue samples had been obtained for culture (for a revision procedure). After the operation, the patients were assessed daily while hospitalized and then at two to three months and one year after the operation. Demographic characteristics and risk factors were similar in the two groups. For the patients who had had a primary hip arthroplasty, the rate of deep wound infection was 0.5 per cent (one of 187) for those who had received cefuroxime and 1.2 per cent (two of 168) for those who had received cefazolin. For the patients who had had a primary knee arthroplasty, the rate of deep wound infection was 0.6 per cent (one of 178) for those who had received cefuroxime and 1.4 per cent (three of 207) for those who had received cefazolin.(ABSTRACT TRUNCATED AT 250 WORDS)

Gentamicin-impregnated polymethylmethacrylate beads compared with systemic antibiotic therapy in the treatment of chronic osteomyelitis.

A model of chronic osteomyelitis was used to evaluate the efficacy of treatment with debridement alone; debridement plus gentamicin-polymethylmethacrylate (PMMA) bead implantation; debridement plus systemic antibiotic therapy; and debridement plus systemic antibiotics and bead implantation. Debridement with the implantation of gentamicin-PMMA beads and debridement followed by systemic antibiotics were significantly more successful forms of treatment for chronic osteomyelitis than debridement alone or debridement with the implantation of PMMA beads not impregnated with antibiotics. Debridement followed by the implantation of PMMA-gentamicin beads and the use of systemic antibiotics produced the greatest success rate. Treatment with a combination of gentamicin-PMMA beads and systemic antibiotics resulted in a 100% success rate, which, although not statistically better than either treatment alone, suggests a trend.

Comparison of the clinical efficacy and tolerance of gentamicin PMMA beads on surgical wire versus combined and systemic therapy for osteomyelitis.

These data do not prove a statistical superiority of conventional antibiotics or Septopal in the treatment of chronic osteomyelitis. This result, however, is complicated by the biased data set represented by the combined treatment. The data do suggest that cost of treatment is considerably less in patients who are treated with local antibiotics (i.e., Septopal) alone. The rate of adverse experiences was directly related to the use of parenteral antibiotics, with higher rates of adverse experiences in the conventional and combined treatment groups. Furthermore, the Cierny-Mader Physiologic Class had the best correlation with outcome, suggesting that host factors are probably of critical importance in inducing remission of chronic osteomyelitis. This protocol was not designed to test the role of debridement in the treatment of osteomyelitis: it was assumed that debridement would be the same in both groups. It is the investigators' strong opinion, however, that adequacy of debridement was an important determinant in quiescence or recurrence in the study patients. Similarly, there was no strict control for adequacy of soft-tissue coverage provided by local or distant tissue transfer. Again, the investigators believe that adequacy, including viability and durability, of soft-tissue covering was an important determinant for the end result in these patients. Other covariants such as smoking, history, nutritional status, and other measures of general health will be added to this model when data are available. This analysis will allow definition of the appropriate clinical situations in which use of Septopal alone or combined with parenteral antibiotic is indicated.

A comparison of gentamicin-impregnated polymethylmethacrylate bead implantation to conventional parenteral antibiotic therapy in infected total hip and knee arthroplasty.

A multicenter study of infected total knee and total hip arthroplasties was conducted from 1985 until 1990. Twenty-eight patients (22 total hip arthroplasties and six total knee arthroplasties) who had periprosthetic infections were treated according to a prospective, randomized protocol. After initial debridement for their infections, patients were randomized into one of the two following groups: Group I, debridement and the implantation of gentamicin-polymethylmethacrylate (PMMA) beads; and Group 2, debridement and conventional parenteral systemic antibiotic therapy. After initial treatment, the patients were then scheduled for a delayed reconstruction total joint arthroplasty. Of the 28 patients, 25 subsequently had delayed total arthroplasty, and if acrylic bone cement was used for fixation at the time of reimplantation, antibiotics were not added to the cement. The average follow-up period was three years (range, six months to 5.6 years). Infection recurred in two patients treated by debridement and the implantation of gentamicin-PMMA beads (15%) and in four patients treated with debridement and conventional systemic antibiotic therapy (30%). All recurrences occurred in patients who had infected total hip arthroplasties; none occurred in patients with total knee arthroplasties. The conditions that were common in patients with recurrent infection were (1) multiple previous surgeries, (2) host compromise and malnutrition, (3) extensive infection, and (4) inadequate debridement. The recurrence of infection was not statistically significantly more common in either treatment group. The outcome of treatment in patients with infected total joint arthroplasties using debridement, gentamicin-PMMA bead implantation,and a two-stage delayed reconstruction was similar to that of patients treated with debridement combined with conventional parenteral systemic arthroplasty and two-stage reconstruction.

The effect of wound environment on the incidence of acute osteomyelitis.

A model was developed to identify and compare the local wound factors that induce acute osteomyelitis in a prospective, controlled investigation. When compared with wounds containing either virulent bacteria or dead bone, statistical analysis disclosed a significant increase in the incidence of osteomyelitis when virulent bacteria and dead bone were combined. The incidence of osteomyelitis in wounds containing an inoculated, hematoma-filled dead space was significantly less when compared with wounds containing dead bone and virulent bacteria. The incidence of osteomyelitis is significantly less when a nonvirulent strain of bacteria is substituted for a virulent strain. Although rigid internal fixation increased the incidence of osteomyelitis to 100% and long-term antibiotic therapy decreased the incidence, these changes were not statistically significant. These data allow the authors to predict the relative risk of osteomyelitis when these wound factors are present. The prevention of osteomyelitis depends on the clinical identification and modification of these local wound factors.

Intrapelvic extraction of a total hip prosthesis. A case report.

A 69-year-old man with a total hip prosthesis, recurrent infection, and intrapelvic incarceration of the acetabular components required extraction of a long-stem total hip prosthesis through three incisions. Retroperitoneal intrapelvic extraction of the incarcerated prosthesis was necessary. This approach allowed removal of intrapelvically migrated components and the eradication of the infection. The patient had no signs of infection five years postoperatively.

Antibiotic prophylaxis following lower urinary tract instrumentation.

The value of routine antibiotic prophylaxis was assessed in 362 women undergoing lower urinary tract instrumentation. A three-day course of a once-a-day dose of 1 g of cefadroxil was compared with a three-day course of 100 mg of nitrofurantoin three times a day, in a randomized investigator blinded placebo controlled study. Both study drugs were significantly more effective in preventing postinstrumentation urinary tract infections than placebo (p less than 0.003). Differences in efficacy between the two test drugs were not significant; however, side effects in the nitrofurantoin group were more frequent and severe than those in the cefadroxil group. Cefadroxil also offered the advantage of a once-daily dosing schedule.

Clinical evaluation of Abbott and Wellcome enzyme linked immunosorbent assays for detection of serum antibodies to human immunodeficiency virus (HIV).

Abbott and Wellcome enzyme linked immunosorbent assays (ELISAs) for detection of antibodies to human immunodeficiency virus (HIV) were compared in tests on 932 sera collected predominantly from male homosexuals attending a sexually transmitted disease (STD) clinic in central London. Two hundred and twenty three sera had HIV antibodies detected by both types of assay, with confirmation of the results by further tests carried out at the Virus Reference Laboratory (VRL) in Colindale. There was a 97.3% correlation between the results obtained by the two commercial ELISA assays on the tests carried out on unheated sera. The Abbott ELISA gave significantly more false positive results than the Wellcome test when the manufacturer's instructions for cut off values were followed. There was one false negative Abbott results: it failed to react to repeated Abbott ELISA but was positive by Wellcome and confirmatory assays. Of 283 heat treated sera 14.8% gave falsely reactive results with the Abbott assay whereas there were no differences between heated and unheated sera with the Wellcome assay. VRL or Western blot confirmatory assays, or both, confirmed all the 235 positive results obtained with the Wellcome assay.

Molecular cloning of a pIP501 derivative yields a model replicon for the study of streptococcal conjugation.

We have previously constructed a derivative of the broad host range streptococcal plasmid pIP501, a conjugative plasmid designated pVA797, that confers chloramphenicol resistance and contains a unique EcoRI site in a non-essential region of the plasmid molecule. pVA797 (30.7 kb) when cloned in toto as an EcoRI fragment into the positive selection vector pOP203(A2+) gave a recombinant, pVA904 (37.7 kb), which was able to replicate in Escherichia coli and in streptococcal species. It can be phenotypically monitored in either genus by specific drug resistance markers (chloramphenicol resistance in streptococci, tetracycline resistance in E. coli). pVA904 segregates into E. coli minicells where it specifies the production of at least 13 polypeptides. Many of the polypeptides are missing in minicells containing a transfer-defective, deletion derivative of pVA904. pVA904 is an ideal model replicon for the study of streptococcal conjugation because it is a shuttle plasmid thus enabling manipulation using procedures established for E. coli. Specifically, it should be possible to define the genetic basis of streptococcal conjugation by coupling mutagenesis protocols and minicell protein analyses in E. coli with evaluation of transfer function in streptococci.

Novel shuttle plasmid vehicles for Escherichia-Streptococcus transgeneric cloning.

A novel plasmid vector that is able to replicate both in Escherichia coli and in Streptococcus sanguis is described. This 9.2-kb plasmid, designated pVA856, carries Cmr, Tcr, and Emr determinants that are expressed in E. coli. Only the Emr determinant is expressed in S. sanguis. Both the Cmr and the Tcr of pVA856 may be insertionally inactivated. This plasmid affords several different cleavage-ligation strategies for cloning in E. coli followed by subsequent introduction of chimeras into S. sanguis. In addition, we have modified a previously described E. coli-S. sanguis shuttle plasmid [pVA838; Macrina et al., Gene 19 (1982) 345-353], so that it is unable to replicate in S. sanguis. The utility of such a plasmid for cloning and selecting sequences enabling autonomous replication in S. sanguis is demonstrated.