Australasian Laparoscopic Colon Cancer Study shows that elderly patients may benefit from lower postoperative complication rates following laparoscopic versus open resection.

BACKGROUND: A retrospective analysis of age-related postoperative morbidity in the Australia and New Zealand prospective randomized controlled trial comparing laparoscopic and open resection for right- and left-sided colonic cancer is presented. METHODS: A total of 592 eligible patients were entered and studied from 1998 to 2005. RESULTS: Data from 294 patients who underwent laparoscopic and 298 who had open colonic resection were analysed; 266 patients were aged less than 70 years and 326 were 70 years or older (mean(s.d.) 70.3(11.0) years). Forty-three laparoscopic operations (14.6 per cent) were converted to an open procedure. Fewer complications were reported for intention-to-treat laparoscopic resections compared with open procedures (P = 0.002), owing primarily to a lower rate in patients aged 70 years or more (P = 0.002). Fewer patients in the laparoscopic group experienced any complication (P = 0.035), especially patients aged 70 years or above (P = 0.019). CONCLUSION: Treatment choices for colonic cancer depend principally upon disease-free survival; however, patients aged 70 years or over should have rigorous preoperative investigation to avoid conversion and should be considered for laparoscopic colonic resection. REGISTRATION NUMBER: NCT00202111 (http://www.clinicaltrials.gov).

Classifying algorithms for SIFT-MS technology and medical diagnosis.

Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS) is an analytical technique for real-time quantification of trace gases in air or breath samples. SIFT-MS system thus offers unique potential for early, rapid detection of disease states. Identification of volatile organic compound (VOC) masses that contribute strongly towards a successful classification clearly highlights potential new biomarkers. A method utilising kernel density estimates is thus presented for classifying unknown samples. It is validated in a simple known case and a clinical setting before-after dialysis. The simple case with nitrogen in Tedlar bags returned a 100% success rate, as expected. The clinical proof-of-concept with seven tests on one patient had an ROC curve area of 0.89. These results validate the method presented and illustrate the emerging clinical potential of this technology.

The rapid evaluation of bacterial growth in blood cultures by selected ion flow tube-mass spectrometry (SIFT-MS) and comparison with the BacT/ALERT automated blood culture system.

We compared the performance of the BacT/ALERT automated blood culture system with real-time, quantitative volatile organic compound (VOC) detection by selected ion flow tube-mass spectrometry (SIFT-MS). Blood samples from healthy donors were artificially infected with 5 or 100 CFU of organisms commonly causing bacteremia. Positive results by SIFT-MS analysis of headspace gases were recorded for 53/60 (88.3%) bottles at 8h, and 58/60 (96.6%) bottles at 24 h. We conclude that SIFT-MS is a sensitive method for the detection of microbial VOCs. Furthermore, profiles of the VOCs detected may allow simultaneous identification of infecting organisms.

The effect of Helicobacter pylori infection and dietary iron deficiency on host iron homeostasis: a study in mice.

BACKGROUND: Helicobacter pylori, which requires iron to survive, may cause host iron deficiency by directly competing with the host for available iron or by impairing iron uptake as a consequence of atrophy-associated gastric hypochlorhydria. The aim of this study was to examine the effect of H. pylori infection and dietary iron deficiency on host iron homeostasis in a mouse model. MATERIALS AND METHODS: H. pylori SS1-infected and uninfected C57BL/6 mice, fed either a normal diet or an iron-deficient diet, were assessed for iron status and infection-associated gastritis over a 30-week period. RESULTS: After 10 weeks, serum ferritin values were higher in H. pylori-infected mice than in uninfected controls, irrespective of dietary iron intake (p = .04). The infection-related increase in body iron stores persisted in the iron-replete mice but diminished over time in mice with restricted dietary iron intake (p < .0001). At 30 weeks serum ferritin levels were lower in these animals (p = .063). No significant difference in bacterial numbers was detected at the 30-week time point (p > .05) and the histological changes observed were consistently associated with infection (p < .01) and not with the iron status of the mice (p = .771). CONCLUSIONS: Infection with H. pylori did not cause iron deficiency in iron-replete mice. However, diminished iron stores in mice as a result of limited dietary iron intake were further lowered by concurrent infection, thus indicating that H. pylori competes successfully with the host for available iron.

Alcohol in breath and blood: a selected ion flow tube mass spectrometric study.

In this paper we compare the amounts of ethanol in breath and in blood after ingestion of whisky using analysis by selected ion flow tube mass spectrometry (SIFT-MS). Blood ethanol concentrations were also obtained using standard hospital forensic procedures for blood alcohol analyses. We demonstrate the quantitative nature of SIFT-MS analysis by correlating the observed alcohol content of the headspace above 5-mL amounts of venous blood and aqueous solution to which known trace amounts of alcohol have been added. This procedure provides a Henry's Law coefficient for ethanol in aqueous solution at 298 +/- 3 K of 209 +/- 7 mol/kg*bar. We also demonstrate that measurement of the ethanol concentration in the alveolar portion of a single breath using the SIFT-MS technique gives an accurate measure of blood alcohol and could obviate the need for blood samples in forensic processing. The storage performance of breath samples in Mylar bags with a volume greater than 1 L has been shown to maintain the mixture integrity for ethanol but not for some other species.

Iron influences the expression of Helicobacter pylori outer membrane vesicle-associated virulence factors.

BACKGROUND: Helicobacter pylori shed outer membrane vesicles (OMV) in vitro and in vivo. These OMV, which contain active VacA, provide a potential vehicle for the delivery of H. pylori virulence factors to the gastric mucosa. OBJECTIVE: To assess the influence of environmental iron levels on H. pylori OMV VacA and protease expression in vitro. METHODS: Three well-characterized H. pylori type-strains were grown for 72 h under normal (Brucella broth, 5% fetal calf serum) and iron-limiting (Brucella broth, 5% fetal calf serum, 50 micromol/l deferoxamine) conditions. Following harvesting by differential centrifugation, the ratio of whole cells to OMV was determined. OMV VacA levels in response to iron availability were determined by ELISA and immunolabelling of washed bacteria. Protease activity was detected by zymography of OMV in the presence and absence of enzyme inhibitors and activators. HEp-2 cells were used to assay for OMV-associated cytopathogenic toxins. RESULTS: Decreased iron availability, which limited bacterial growth but not OMV release, also influenced the expression of OMV-associated virulence factors. VacA levels were reduced, whereas two new proteolytic enzymes were expressed on these OMV. When an iron salt was added to counteract the effect of the deferoxamine, VacA levels were restored in the outer membrane and the proteolytic activity disappeared. CONCLUSIONS: These results suggest that OMV release by H. pylori is influenced by environmental iron levels, and that the qualitative changes that occur in outer membrane composition may contribute to the clinical patterns of H. pylori-associated disease.

Is the port site really at risk? Biology, mechanisms and prevention: a critical view.

Early case reports of port site tumour implants led to debate regarding the appropriateness of laparoscopic techniques for abdominal malignancies. Review of clinical, animal and cell culture studies addresses the relationships between tumour staging and shed cell behaviour that contributes to the peri-operative spread of tumours. In addition, a porcine model was used to test tumour cell distribution after laparoscopic and open colonic resections. Clinical evidence indicate that wound recurrence rates are 0.60 and 0.85% for open and laparoscopic colon cancer operations, respectively. Tumour staging and operative techniques are the most important factors determining wound implantation. Port site and open wounds are at equal risk of tumour implantation.

Tumour cell wound distribution after colectomy in a porcine model.

BACKGROUND: Concerns over tumour implants have impeded the adoption of laparoscopic surgery for cancer. Explanations assume an increased number of malignant cells present in trocar wound sites. The following are tested in the present paper: (i) that the magnitude of wound contamination following surgery is related to the location of the tumour cells; and (ii) the surgical approach. METHODS: We have used a porcine sigmoid colectomy model to compare the number of tumour cells on laparoscopic wounds after resections in the presence of intraluminal, intramural and intraperitoneal 51Cr-labelled, fixed HeLa tracer cells. Open colectomies were also performed in the presence of intraperitoneal tracer cells and their numbers on laparotomy wound surfaces were determined by gamma counting. RESULTS: With intraperitoneal cells, laparotomies had 1087 (+/- 106) tracer cells per mm (n = 4) while trocar wounds had 103 (+/- 54) cells per mm (n = 10) (P > 0.05). Resection of intramural tumours resulted in lower trocar wound contamination (0.9 +/- 0.6 cells/mm, n = 3). Resection of colon including intraluminal tracer cells resulted in 2.9 +/- 2.1 cells/mm on trocar wounds (n = 3). CONCLUSIONS: More tumour cells were deposited on open than laparoscopic trocar wound surfaces. Also, the risk of wound implantation is less with intraluminal or intramural tumours than with intraperitoneal cells (P > 0.05).

Lack of protection following immunisation with H. pylori outer membrane vesicles highlights antigenic differences between H. felis and H. pylori.

Helicobacter pylori-induced inflammation is associated with the development of gastritis, peptic ulcer disease and gastric cancer in humans. Immunisation against this bacterium would ultimately have a major impact on H. pylori-related disease, notably global gastric cancer rates. To date, several potential H. pylori vaccine candidates have been identified. In this study, the Helicobacter felis/murine model was used to assess the immunogenicity of a previously undescribed H. pylori outer membrane vesicle fraction in immune protection.

Operative factors affecting tumor cell distribution following laparoscopic colectomy in a porcine model.

BACKGROUND: An increased risk of laparoscopic port wound tumor implantation in the presence of overt or covert abdominal malignancy has been identified. PURPOSE: A porcine laparoscopic colectomy model has been used to quantify the influence surgical practices may have on tumor cell implantation. METHODS: 51Cr-labeled, fixed HeLa cells were injected intraperitoneally before surgery. Tumor cell contamination of instruments, ports, security threads, and excised wound margins was assessed by gamma counting. RESULTS: Greatest contamination occurred in ports used by the operating surgeon under pneumoperitoneum (64 percent of all port wound tumor cells) and mechanical elevation (76 percent). Gasless surgery in patients in the head-down position increased the rostral accumulation of tumor cells in the abdomen and right upper quadrant port wound by 330 and 176 percent, respectively. Under pneumoperitoneum, port movement was the major contributor to port leakage and wound contamination (21 percent of total recovered wound tumor cells per port). Tumor cells were not carried in aerosol form. Instrument passage and the withdrawal of security threads through the abdominal wall increased port wound contamination 430 and 263 percent, respectively, over pneumoperitoneum control ports. Preoperative lavage reduced by 61 percent, but did not eliminate, wound contamination. CONCLUSION: This porcine model may be used to evaluate surgical factors for the impact on port wound contamination.

37 kBq 14C-urea breath test and gastric biopsy analyses of H. pylori infection.

BACKGROUND: The treatment of H. pylori-associated gastroduodenal disease is increasingly aimed at bacterial eradication which requires follow-up assessment of therapeutic effectiveness and re-infection. A simplified 37 kBq 14C-urea breath test for H. pylori infection has been developed. METHODS: The 37 kBq 14C-urea breath test was compared with biopsy urease (CLO) and histological analyses of gastric-biopsies obtained from 63 patients undergoing endoscopy. RESULTS: The 30-min breath test correlated closely with biopsy findings, had a sensitivity of 100%, a specificity of 95% and a positive predictive value of 92%. CONCLUSIONS: The simplified, low-dose, 14C-urea breath test is a convenient, low-cost, transportable means of facilitating the management of H. pylori-associated diseases.

Dual silver staining to characterise Helicobacter spp. outer membrane components.

Helicobacter pylori is a bacterial pathogen, estimated to infect half the world's population. The bacterium is the aetiological cause of gastritis, the common precursor for peptic ulcer disease and gastric cancer. Immunisation of at-risk individuals is the most cost-effective means of dealing with such a widespread pathogen. Potential vaccine candidates need to be identified and characterised. Conventional silver staining is commonly used for the sensitive detection of bacterial protein components separated by SDS-PAGE. Modified silver stains employing periodate oxidation have also been developed for the analysis of purified bacterial lipopolysaccharide. By using these methods in parallel, as a dual silver stain, bacterial fractions can be characterised in terms of protein and LPS content. Strain differences can also be readily identified by comparing protein and LPS profiles. When combined with differential immunoblotting, the dual silver stain is a useful analytical tool for characterising potential vaccine candidate antigens.

Polymorphonuclear leukocyte-mediated bone degradation and influence of blood mononuclear cells on the mouse calvarial model.

OBJECTIVE: To investigate the relationships between degradation of bone and activated blood polymorphonuclear leukocytes (PMNL) and mononuclear leukocytes (ML) as well as their soluble products in vitro. MATERIALS AND METHODS: A neonatal mouse calvarial bone model was used to assess the activity of degradation (by measuring the amount of 45Ca release) by normal human blood leukocytes, separated PMNL and ML following 24-hour incubation. The effects of conditioned culture medium obtained from Staphylococcus aureus-stimulated ML on PMNL-mediated calvarial bone loss were also studied. RESULTS: It was demonstrated that isolated human PMNL rapidly degraded bone in a dose and time dependent manner. The PMNL-mediated bone degradation was enhanced by conditioned medium obtained from Staphylococcus aureus-stimulated ML. CONCLUSION: These findings implicate PMNL as major contributors to early bone loss in infectious diseases such as acute haematogenous osteomyelitis.

The fate of ingested 14C-urea in the urea breath test for Helicobacter pylori infection.

The metabolic fate of the radioactive carbon in the 14C-urea breath test for Helicobacter pylori was investigated in 18 subjects. After ingestion of labelled urea, breath was sampled for 24 h, and urine was collected for 3 days. Subjects were designated high or low expirers on the basis of their breath counts, and this agreed well with H. pylori serologic analyses. When given 185 or 37 kBq of 14C-urea, 51% (SD = 16%, n = 11) of the label was recovered from the breath of high expirers, and 7% (SD = 3%, n = 7) from the breath of low expirers. The mean combined urinary and breath recovery for high expirers was 86% (SD = 7%), and for low expirers it was 97% (SD = 3%). It is concluded that the long-term retention of 14C from ingested 14C-urea is low. The results enable a more accurate estimation to be made of radiation exposure resulting from the 14C-urea breath test.

Fusidic acid prophylaxis before cataract surgery: patient self-administration.

In a placebo-controlled, randomised, double-blind clinical trial, the authors evaluated the efficacy of patient-administered 1% fusidic acid viscous eye drops in clearing the commonest organisms causing pseudophakic endophthalmitis (Staphylococcus epidermidis and aureus) from the lids and conjunctivae of 79 patients before cataract surgery. The treatment group self-administered fusidic acid viscous eye drops four times daily for seven days before surgery; the placebo group received inert ophthalmic drops. Fellow eyes of both groups remained untreated as a natural control. Lower fornix and lid margin cultures were taken from both eyes before and after treatment. Before treatment, there was no statistical difference in organism counts between the groups. After treatment, eyes receiving fusidic acid were more likely to be free of clinically relevant Staphylococcus spp. than all pre-treatment eyes (for lids, P << 0.001; conjunctivae, P = 0.02). A highly significant (P < 0.001) number of lid margins were rendered 'clinically clean' (i.e., 0-49 organisms/swab) by fusidic acid when compared with untreated eyes. Treatment also effectively (P < 0.05) reduced the numbers of bacteria isolated from conjunctivae. This study indicates that there is a highly significant reduction of Staphylococcus spp. (P << 0.001), non-Staphylococcus spp. (P << 0.001) and attainment of sterile eyes (P << 0.001) at operation gained by patient self-administration of 1% fusidic acid four times daily for seven days before surgery.

Antibacterial action of the urease inhibitor acetohydroxamic acid on Helicobacter pylori.

The urease inhibitor acetohydroxamic acid (AHA) was assessed for its bacteriostatic and bactericidal effects on Helicobacter pylori. For eight isolates of H pylori, the minimum inhibitory concentration (MIC) was either 200 mg/l or 400 mg/l. Interactions between AHA and antimicrobial drugs used to treat H pylori were also determined. For most isolates AHA reduced the MIC for colloidal bismuth subcitrate (CBS), tetracycline, metronidazole, and amoxicillin. In a few isolates, however, AHA increased the minimum bactericidal concentration (MBC) for these antimicrobial treatments. In vitro AHA is active against H pylori and it interacts with other agents directed against H pylori.