Antibacterial isoeugenol coating on stainless steel and polyethylene surfaces prevents biofilm growth.

AIMS: Pathogenic bacteria can spread between individuals or between food items via the surfaces they share. Limiting the survival of pathogens on surfaces, therefore, presents an opportunity to limit at least one route of how pathogens spread. In this study, we propose that a simple coating with the essential oil isoeugenol can be used to circumvent the problem of bacterial transfer via surfaces. METHODS AND RESULTS: Two commonly used materials, stainless steel and polyethylene, were coated by physical adsorption, and the coatings were characterized by Raman spectroscopy, atomic force microscopy and water contact angle measurements. We quantified and visualized the colonization of coated and uncoated surfaces by three bacteria: Staphylococcus aureus, Listeria monocytogenes and Pseudomonas fluorescens. No viable cells were detected on surfaces coated with isoeugenol. CONCLUSIONS: The isoeugenol coating prepared with simple adsorption proved effective in preventing biofilm formation on stainless steel and polyethylene surfaces. The result was caused by the antibacterial effect of isoeugenol, as the coating did not diminish the adhesive properties of the surface. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study demonstrates that a simple isoeugenol coating can prevent biofilm formation of S. aureus, L. monocytogenes and P. fluorescens on two commonly used surfaces.

Recombination in Mycoplasma hominis.

Mycoplasma hominis has been previously described as a heterogeneous species, and in the present study intraspecies diversity of 20 M. hominis isolates from different individuals was analyzed using parts of the unlinked gyrase B (gyrB), elongation factor Tu (tuf), SRalpha homolog (ftsY), hitB-hitL, excinuclease ABC subunit A (uvrA) and glyceraldehyde-3-phosphate dehydrogenase (gap) genes. The level of variability of these M. hominis genes was low compared with the housekeeping genes from Helicobacter pylori and Neisseria meningitidis, but only few M. hominis isolates had identical sequences in all genes indicating the presence of recombination. In order to test for intergenic recombination, phylogenetic trees were reconstructed for each of the genes but no well-supported bifurcating phylogenetic trees could be obtained. The genes were tested for intragenic recombination using the correlation between linkage disequilibrium and distance between the segregating sites, by the homoplasy ratio (H ratio), and by compatibility matrices. The gap gene showed well-supported evidence for high levels of recombination, whereas recombination was less frequent and not significant within the other genes. The analysis revealed intergenic and intragenic recombination in M. hominis and this may explain the high intraspecies variability. The results obtained in the present study may be of importance for future population studies of Mycoplasma species.

Evaluation of real-time quantitative PCR for identification and quantification of Chlamydia pneumoniae by comparison with immunohistochemistry.

Chlamydia pneumoniae is a common cause of community-acquired pneumonia and it has been associated with atherosclerosis. C. pneumoniae has usually been diagnosed by serology using a microimmunofluorescence test, but more recently polymerase chain reaction (PCR) has been viewed as an advantageous alternative. We developed a quantitative real-time PCR for detection of C. pneumoniae. Primers were targeted for the pmp4 gene, and the PCR fragment was detected real-time with a fluorescence resonance energy transfer probe set using a LightCycler instrument. The PCR was used on DNA released from 50 microm sections of paraffin-embedded formalin-fixed lung tissue from experimentally infected mice. Thereby, the number of C. pneumoniae genomes was determined. To our knowledge this is the first time quantification of C. pneumoniae DNA has been attempted on paraffin-embedded formalin-fixed tissue. C. pneumoniae-specific immunohistochemistry (IHC) was done on 5 microm sections adjacent to the sections used in PCR, and the number of inclusions were counted in each section. Good correlation was found when comparing results from PCR and IHC, which is in contrast to many previous studies.

Characterization of the variability of a 75-kDa membrane protein in Mycoplasma hominis.

The gene p75 encoding a 75-kDa surface-exposed membrane protein P75 was cloned and sequenced from Mycoplasma hominis type strain PG21T. To investigate the intraspecies variability, sequences were obtained from an additional two isolates 7488 and 183, and the three sequences were compared. The nucleotide and amino acid differences were not confined to specific regions of the gene/protein, but when comparing the three sequences, differences were present as single site substitutions or small insertions or deletions of nucleotides/amino acids. The intraspecies variability was further investigated by restriction enzyme analysis with two restriction enzymes (Alul and MboII) of PCR products amplified from p75 from 28 M. hominis isolates. On the basis of band patterns produced by the two restriction enzymes, the isolates could be divided into five and six groups. These groups neither matched categories of the M. hominis vaa gene nor the M. hominis p120 gene classes, indicating that the three genes vary by different mechanisms and possibly indicating horizontal gene transfer. Federation of European Microbiological Societies.

Cloning, sequencing and variability analysis of the gap gene from Mycoplasma hominis.

The gap gene encodes the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The gene was cloned and sequenced from the Mycoplasma hominis type strain PG21(T). The intraspecies variability was investigated by inspection of restriction fragment length polymorphism (RFLP) patterns after polymerase chain reaction (PCR) amplification of the gap gene from 15 strains and furthermore by sequencing of part of the gene in eight strains. The M. hominis gap gene was found to vary more than the Escherichia coli counterpart, but the variation at nucleotide level gave rise to only a few amino acid substitutions. To verify that the gene was expressed in M. hominis, a polyclonal antibody was produced and tested against whole cell protein from 15 strains. The enzyme was expressed in all strains investigated as a 36-kDa protein. All strains except type strain PG21(T) showed reaction to a 104-kDa band in addition to the expected 36-kDa band. The protein reacting at 104 kDa is a M. hominis protein with either an epitope similar to one on GAPDH, or it is an immunoglobulin binding protein.

Doppler ultrasound assessment of TIPS patency and function--the need for echo enhancers.

PURPOSE: The aim of this study was to illustrate the versatility of an i.v. administered echo enhancer for Doppler US assessment of TIPS patency and function. MATERIAL AND METHODS: A total of 22 Doppler US evaluations of TIPS patency and function were performed in 5 patients with alcoholic cirrhosis and recurrent oesophageal bleeding who had been treated with TIPS. TIPS patency was evaluated by means of colour or power Doppler US. The volume flow (VF) was assessed in the TIPS and in the portal vein by spectral Doppler. The ratio of the VF in the TIPS to the VF in the portal vein (T/P ratio) was used to express the functional status of the TIPS. If Doppler signals were inconclusive or absent, echo-enhanced US was performed. RESULTS: In 22 follow-up Doppler US examinations, echo-enhanced Doppler US was required in 7 cases (29%). The Doppler enhancement persisted in the range of 3-5 min. No adverse effects were observed. An apparently normal TIPS function reflected a T/P ratio in the range of 0.44-1.10, median 0.78 +/- 0.20 (2SD). CONCLUSION: The i.v. administration of echo enhancers would seem to be indicated in the assessment of the TIPS function if conventional Doppler US fails to prove normal TIPS patency and function. The T/P ratio may be a convenient monitoring parameter for reflecting the TIPS function.

DNA sequencing reveals limited heterogeneity in the 16S rRNA gene from the rrnB operon among five Mycoplasma hominis isolates.

To investigate the intraspecies heterogeneity within the 16S rRNA gene of Mycoplasma hominis, five isolates with diverse antigenic profiles, variable/identical P120 hypervariable domains, and different 16S rRNA gene RFLP patterns were analysed. The 16S rRNA gene from the rrnB operon was amplified by PCR and the PCR products were sequenced. Three isolates had identical 16S rRNA sequences and two isolates had sequences that differed from the others by only one nucleotide.

[Transjugular intrahepatic portosystemic shunt. Treatment of patients with recurrent bleeding from esophageal varices]. / Transjugular intrahepatisk portosystemisk shunt. Behandling af patienter med recidiverende esophagusvariceblødning.

We report the results of transjugular intrahepatic portosystemic shunt (TIPS) procedure in six patients with liver cirrhosis and recurrent bleeding or acute intractable bleeding from oesophageal varices in spite of multiple sessions of sclerotherapy. Median follow-up was 15 months (range 1-24 months). The procedure was technically successful in all patients without procedure-related morbidity or mortality. Four of the procedures were performed electively and two as an emergency procedure. The portosystemic pressure gradient decreased to below 12 mmHg following TIPS implantation and the shunt bloodflow was one quarter to three-quarters of the portal bloodflow determined by Doppler ultrasound. Recurrent bleeding occurred in one patient but was amenable to endoscopic sclerotherapy. In this patient the shunt had developed a stenosis that was treated by balloondilatation and insertion of an additional stent six months following the initial procedure, and no further bleeding occurred. The remaining five patients had no rebleeding episodes. Repeated Doppler examinations in the followup period demonstrated patency of all shunts. None of the patients developed portosystemic encephalopathy. One patient died of cerebral haemorrhage, unrelated to TIPS, 16 months following implantation. Another patient died 14 months following TIPS due to acute mesenteric occlusion and septicaemia. We conclude that TIPS is feasible and effective in selected patients with liver cirrhosis and persistent or recurrent variceal bleeding following repeated endoscopic therapy.

Somatostatin reduces bile secretion and loss of bile constituents in patients with external biliary drainage.

The effect of 24-hours continuous somatostatin-14 infusion on the volume of the bile secretion and on the bile composition were studied in seven patients with malignant biliary obstruction who had transhepatic external biliary drainage. The bile acid composition was measured with high performance liquid chromatography (HPLC). Somatostatin infusion significantly reduced the daily bile loss from median 473 ml to 140 ml (41 per cent, p = 0.01) with a concomitant significant reduction in the daily molar loss of cholesterol, triglyceride, Na+, K+, Cl-, Ca+2 and Mg+2. The loss of chloride and sodium was reduced with median 50 mmol/day each (p = 0.01). The relative concentrations of the measured bile constituents did not change significantly, except for bile acids (p = 0.02): the concentration of glycochenodeoxycholic acid increased significantly (p = 0.04). The molar loss of taurocholic acid decreased significantly (p = 0.035), so the increased concentration of glycochenodeoxycholic acid resulted only in a marginally significant reduction in the total molar loss of bile aids (p = 0.051). Somatostatin is a potent inhibitor of bile secretion. The peptide may be used in severely bile depleted patients for reducing their serious electrolyte and acidity problems. Analysis of bile acid composition by HPLC is well suited for further investigations of the regulatory mechanisms of bile acid secretion.

Flow measurements with digital subtraction densitometry in a steady flow experimental model.

Computerized densitometry was applied on digital subtraction series for measuring flow rates, 600 to 2,000 ml/min, in model experiments, using contrast medium as indicator substance. A total of 962 measurements were performed, employing the Stewart-Hamilton dilution technique, as well as direct measurements of velocity of the indicator bolus between 2 measuring sites. Results with the dilution technique were closely correlated with true values, but slightly lower (mean 8%), presumably because of sedimentation of contrast medium. Measurements based on bolus velocity were most accurate when the bolus passage was defined by points near the gravity line of the area under the concentration curve. Use of more easily identified curve points, e.g. the time of curve maximum, tended to yield too high values due to flow laminarity with a high-velocity leading edge of the indicator. Variation in repeated measurements on any single image series was attributed to the low sampling rate.

Percutaneous gastrostomy guided by ultrasound and fluoroscopy.

Percutaneous gastrostomy, utilizing a dedicated catheterization kit, with a combination of ultrasonographic (US) and fluoroscopic guidance, was carried out in 27 patients. The main indication for gastrostomy was the need for nutritional support in malignant esophageal stricture. After distending the stomach with water via a nasogastric tube, the gastric antrum was punctured under US guidance and a guide wire was inserted, followed by fluoroscopically guided tract dilatation and insertion of a 2.5-mm Cope-loop catheter. In all patients but one (96%) the procedure was successfully completed in one or 2 attempts. Two complications occurred: one case of a small subcutaneous abscess near the puncture site, and one late incident of dislodgement of a catheter without string-loop fixation, which had been inserted at a catheter exchange after 6 weeks. Percutaneous gastrostomy guided by US and fluoroscopy is a safe and efficacious alternative to endoscopic and surgical gastrostomy.

Low-field MR imaging (0.1 T) in patients with clinically suspected acute spinal block.

The diagnostic usefulness of a 0.1 T MR unit in patients with clinical suspicion of acute spinal block was studied in 59 patients who were referred to acute MR investigation. The records were reviewed retrospectively 1 month after the MR for assessing the clinical impact of the examination. Ninety-eight per cent had a true-positive examination confirmed by surgery (21%) or observation (77%). In 60% of the patients the MR imaging had a therapeutic consequence. In only one patient did the level of visualised pathology at the MR examination not correlate with the clinical findings; the patient subsequently refused surgical treatment. We conclude that a low-field MR unit is excellent for acute examination of patients clinically suspected of acute spinal block.

Percutaneous transhepatic external biliary drainage utilizing a pig tail balloon catheter.

A 2.3-mm soft pig tail balloon catheter was developed to be used for percutaneous transhepatic biliary drainage. A small balloon (OD 10 mm) secures an optimal internal fixation and side holes behind the balloon secure drainage of the cannulated bile duct peripheral to the balloon. Successful transhepatic biliary drainage with the pig tail balloon catheter was achieved in 11 of 12 patients for a period of 3 to 67 days (median 6 days). In one patient the catheter clogged after 55 days of drainage. No case of catheter dislodgement or other complications related to the external drainage was seen.

Paraesophageal varices presenting as a retrocardiac mediastinal mass. A case report.

This report is a reminder that portal hypertension with paraesophageal varices can present as a retrocardiac mass on the chest radiograph. Schistosoma mansoni, the probable etiology in this case, causes periportal fibrosis and is the most common explanation for portal hypertension worldwide. Modern imaging techniques were most helpful in the diagnostic work-up, ultrasonography revealing pathognomonic hyperechoic periportal bands, and CT and MR imaging showing the extent of collaterals.

Contrast radiography in small bowel obstruction. A randomized trial of barium sulfate and a nonionic low-osmolar contrast medium.

Thirty-six adult patients clinically suspected of small bowel obstruction underwent small bowel contrast radiography with either barium sulfate or a nonionic low-osmolar contrast medium after randomization. Films were taken after 2, 4, and 8 hours and later when needed. No difference as regards visualization and diagnostic quality was found between the 2 media. It is concluded that a nonionic low-osmolar contrast medium is an alternative to barium sulfate for small bowel contrast radiography where small bowel obstruction is suspected.

Expandable metallic endoprostheses for biliary obstruction.

Expandable metal stents (20 Gianturco Z-stents and 1 Strecker stent deployed through 8.5 F sheaths) were used with initial success for palliating bile duct obstruction in 10 patients, 8 with malignant and 2 with benign strictures. Short-term failure occurred in one patient after 2 weeks, one died of unrelated causes after 10 days, and one remained jaundiced due to fulminant liver metastases. In the remaining 7 patients the obstruction was markedly palliated, with normalization of the serum bilirubin. Four have died without recurrent bile duct obstruction after a mean of 5.9 months, the 2 with benign strictures are well after 4 and 7 months, and one patient is presently palliated with a plastic endoprosthesis following reocclusion after 4 months. Expandable stents were easier to insert than conventional percutaneous endoprostheses of plastic polymers, and had longer patency in several patients, but reocclusion by tumor growth remains a constant threat in malignant disease. Metallic stents may be the therapy of choice in recurrent benign strictures, although the definitive conclusion needs longer observation and larger materials.

Radiographic evaluation of the urethral Kock ileal bladder substitute.

Fifty male patients who had undergone bladder substitution with a urethral Kock pouch after radical cystectomy for bladder cancer, were evaluated in the immediate postoperative period by retrograde pyelography and pouch cystography, and at later follow-up by pouch cystography. Other radiologic procedures (urography, ultrasonography, CT, etc.) were not part of a routine program, but were used when clinically indicated. In 12% a ureteroileal anastomotic leakage was found; the leaks resolved with continued ureteral stenting. Extravasation at the anastomosis between the pouch and the urethra was seen in 55% at the first cystography. It resolved within one month in all cases by simply leaving a catheter in the bladder. On the late cystograms reflux was observed in 6% of patients, whereas stone formation in the pouch was not encountered. A careful radiologic follow-up of patients with urinary diversions is essential to minimize postoperative complications.