Impact of neoadjuvant chemotherapy on nodal regression and survival in oesophageal adenocarcinoma

BACKGROUND

The prognostic value of lymph node regression (LNR) following neoadjuvant chemotherapy (nCT) for oesophageal and gastro-oeosphageal adenocarcinoma remains unclear. This study aimed to characterise the long-term survival outcomes of LNR in patients having resectional surgery after nCT.

METHODS

This study included patients undergoing oesophagectomy or extended total gastrectomy for oesophageal and junctional tumours (Siewert types 1,2,3) at the Queen Elizabeth Hospital Birmingham from 2012 to 2018. Lymph nodes retrieved at surgery were examined for evidence of a response to chemotherapy. Patients were classified as lymph node-negative (either negative nodes with no evidence of previous tumour involvement or negative with evidence of complete regression) or positive with either partial or no response.

RESULTS

This study identified 183 patients who received nCT, of which 71% (130/183) had positive lymph nodes. Of these 130 patients, 44% (57/130) had a lymph node response and 56% (73/130) did not. The remaining 53 patients (29.0%) had negative lymph nodes with no evidence of tumour. Lymph node responders had a significant survival benefit compared to patients without lymph node response, but shorter than those with negative lymph nodes (median: 27 vs 18 vs NR months, p < 0·001). On multivariable analysis, lymph node responders had an improved overall (Hazard ratio (HR): 0.86, 95% CI: 0.80-0.92, p < 0.001) and recurrence-free (HR: 0.90, 95% CI: 0.82-0.98, p = 0.030) survival.

CONCLUSION

Lymph node regression is an important prognostic factor, warranting closer evaluation over primary tumour response to help with planning further adjuvant therapy in these patients.

Elderly patients have increased perioperative morbidity and mortality from oesophagectomy for oesophageal cancer: A systematic review and meta-analysis

BACKGROUND

Although oesophagectomy remains technically challenging and associated with high morbidity and mortality, it is now increasingly performed in an ever-ageing population with improvement in perioperative care. However, the risks in the elderly population are poorly quantified. The study aims to review the current evidence to quantify further the postoperative risk of oesophagectomy for cancer in the elderly population compared to younger patients.

METHOD

A systematic literature search of PubMed, EMBASE and the Cochrane Library databases was conducted including studies reporting oesophagectomy for cancer in the elderly population. A meta-analysis was reported in accordance with the recommendations of the Cochrane Library and PRISMA guidelines. Primary outcome was overall complications and secondary outcomes were pulmonary and cardiac complications, anastomotic leaks, overall and disease-free survival.

RESULTS

This review identified 37 studies incorporating 30,836 patients. Increasing age was significantly associated with increased rates of overall complications (OR 1.67, CI_95%: 1.42-1.96), pulmonary complications (OR 1.87, CI_95%: 1.48-2.35), and cardiac complications (OR: 2.22, CI_95%: 1.95-2.53). However, there was no increased risk of anastomotic leak (OR: 0.98, CI_95%: 0.85-1.18). Elderly patients were significantly more likely to have lower rates of 5-year overall survival (OR: 1.36, CI_95%: 1.11-1.66) and 5-year disease-free survival (OR: 1.72, CI_95%: 1.51-1.96).

CONCLUSION

Elderly patients undergoing oesophagectomy for cancer are at increased risk of overall, pulmonary and cardiac complications, irrespective of age subgroups, albeit no difference in anastomotic leaks. Therefore, they represent high-risk patients warranting implementation of preoperative pathways such as prehabilitation to improve cardiopulmonary fitness prior to surgery, although benefit of prehabilitation is yet to be proven. This information will also aid future pre-operative counselling and informed consent.

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)

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.

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.

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.

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.

Streptococcal R plasmid pIP501: endonuclease site map, resistance determinant location, and construction of novel derivatives

The streptococcal resistance plasmid pIP501 (30 kilobase pairs [kb]) encodes resistance to chloramphenicol (Cmr) and erythromycin (Emr) and is capable of conjugative transfer among numerous streptococcal species. By using a streptococcal host-vector recombinant DNA system, the Cmr and Emr determinants of pIP501 were localized to 6.3-kb HindIII and 2.1-kb HindIII-AvaI fragments, respectively. pIP501 was lost at a frequency of 22% in Streptococcus sanguis cells grown at 42 degrees C but was stable in cells grown at 37 degrees C (less than 1% frequency of loss). Sequences from a cryptic multicopy plasmid, pVA380-1, were substituted for the pIP501 Emr determinant in vitro, and the resulting recombinant plasmid, designated pVA797, was recovered in transformed S. sanguis cells. The replication of pVA797 was governed by the pVA380-1 sequences based on temperature-stable replication and incompatibility with pVA380-1-derived replicons. The self-ligation of partially cleaved HindIII pIP501 DNA fragments allowed the localization of a pIP501 region involved in autonomous plasmid replication. A small pIP501 derivative (pVA798) obtained from this experiment had a greatly increased copy number but was unstably inherited. Our data indicate that the sequences encoding the resistance determinants and some of the plasmid replication machinery are relatively clustered on the pIP501 molecule. The properties of pVA797 and pVA798 indicate that these molecules will enhance current streptococcal genetic systems from the standpoint of conjugative mobilization (pVA797) and gene amplification (pVA798).

A cloning vector able to replicate in Escherichia coli and Streptococcus sanguis

A plasmid that is able to replicate in both Escherichia coli and Streptococcus sanguis has been constructed by the in vitro joining of the pACYC184 (Cmr Tcr) and pVA749 (Emr) replicons. This plasmid, designated pVA838, is 9.2 kb in size and expresses Emr in both E. coli and S. sanguis. Its Cmr marker is expressed only in E. coli and may be inactivated by addition of DNA inserts at its internal EcoRI or PvuII sites. The pVA838 molecule also contains unique SalI, SphI, BamHI, NruI and XbaI cleavage sites suitable for molecular cloning. pVA838 may be amplified in E. coli but not in S. sanguis. We have used the pVA838 plasmid as a shuttle vector to clone streptococcal plasmid fragments in E. coli. Such chimeras isolated from E. coli were readily introduced into S. sanguis by transformation.

Use of an alcometer in a casualty department

The use of a fuel cell alcometer for breath testing of blood alcohol concentrations of road crash casualties in a casualty department has been evaluated. A high correlation (r=0.89) was shown between the alcometer breath test results and those obtained by blood analysis at the Victoria Police Forensic Laboratory on 100 road crash casualties. The fuel cell alcometer breath test results were above the legal limit (0.05 g/100 mL) in all casualties in whom the blood analysis result exceeded this level. The facility of obtaining an immediate blood alcohol concentration through the use of a fuel cell alcometer permits the early identification and referral of patients with high blood alcohol concentrations to Alcohol and Drug-dependent Services. After further experience, the fuel cell alcometer may also gain a place as a screening device in Australian States which have enacted legislation for compulsory blood alcohol tests on adult road crash casualties. If so, it could obviate the need to take blood from casualties with a negative alcohol concentration.