Contemporary interventional management of pulmonary embolism.

Minimally invasive interventional techniques are being utilised more frequently in the management of acute and chronic pulmonary emboli; however, robust clinical evidence is only emerging for the utilisation of these techniques. Hence, there is a need for a robust mechanism of patient selection and careful consideration of the benefits and risks of the interventions. In this review, we discuss the risk stratification mechanisms; the role of the multidisciplinary pulmonary embolism response team to support decision-making; and describe the various commonly used interventional techniques and how these can be integrated into treatment strategies for the benefit of our patients.

Avoiding stay in the intensive care unit after liver transplantation: a score to assign location of care.

Select liver transplantation (LT) recipients in our program are transferred from operating room to postanesthesia care unit for recovery and extubation with transfer to the ward, completely eliminating an intensive care unit (ICU) stay. Developing a reliable method to determine patients suitable for fast-tracking would be of practical benefit to centers considering this practice. The aim of this study was to create a fast-tracking probability score that could be used to predict successful assignment of care location after LT. Recipient, donor and operative characteristics were assessed for independent association with successful fast-tracking to create a probability score. Of the 1296 LT recipients who met inclusion criteria, 704 (54.3%) were successfully fast-tracked and 592 (45.7%) were directly admitted to the ICU after LT. Based on nine readily available variables at the time of LT, we created a scoring system that classified patients according to the likelihood of being successfully fast-tracked to the surgical ward, with an area under the curve (AUC) of 0.790 (95% CI: 0.765-0.816). This score was validated in an independent group of 372 LT with similar AUC. We describe a score that can be used to predict successful fast-tracking immediately after LT using readily available clinical variables.

Ratiometric and photoconvertible fluorescent protein-based voltage indicator prototypes.

To expand the toolbox of fluorescent protein-based voltage indicators, we explored two distinct protein design strategies. Using these design strategies, we created three new voltage indicators: a red intensiometric voltage indicator (tdFlicR Δ110AR), a green/red ratiometric voltage indicator (tdFlicR-VK-ASAP), and a green to red photoconvertible voltage indicator (FlicGR1).

Bilateral obstruction of bilaterally duplicated collecting systems requiring upper and lower moiety drainage.

A 60-year-old woman with a history of breast cancer presented with bilateral obstruction of bilaterally duplicated renal collecting systems secondary to extrinsic compression from metastatic pelvic lymphadenopathy. Bilateral JJ ureteric stents were inserted, resulting in some improvement of renal function but a failure to normalise completely. Repeat computed tomography demonstrated bilateral duplex collecting systems with persisting obstruction of the undrained moieties. Selective puncture was performed to decompress the obstructed renal moieties for bilateral nephrostomy catheter insertion. This allowed renal function to improve sufficiently for the patient to be discharged and commence chemotherapy. This is the first reported case of bilaterally obstructed partially duplicated collecting systems and it illustrates the importance of recognising anatomical variants to tailor treatment appropriately. It also highlights the important relationship between urology and interventional radiology in the management of such complex patients.

The relationship of TP53 R72P polymorphism to disease outcome and TP53 mutation in myelodysplastic syndromes.

Nonsynonymous TP53 exon 4 single-nucleotide polymorphism (SNP), R72P, is linked to cancer and mutagen susceptibility. R72P associations with specific cancer risk, particularly hematological malignancies, have been conflicting. Myelodysplastic syndrome (MDS) with chromosome 5q deletion is characterized by erythroid hypoplasia arising from lineage-specific p53 accumulation resulting from ribosomal insufficiency. We hypothesized that apoptotically diminished R72P C-allele may influence predisposition to del(5q) MDS. Bone marrow and blood DNA was sequenced from 705 MDS cases (333 del(5q), 372 non-del(5q)) and 157 controls. Genotype distribution did not significantly differ between del(5q) cases (12.6% CC, 38.1% CG, 49.2% GG), non-del(5q) cases (9.7% CC, 44.6% CG, 45.7% GG) and controls (7.6% CC, 37.6% CG, 54.8% GG) (P=0.13). Allele frequency did not differ between non-del(5q) and del(5q) cases (P=0.91) but trended towards increased C-allele frequency comparing non-del(5q) (P=0.08) and del(5q) (P=0.10) cases with controls. Median lenalidomide response duration increased proportionate to C-allele dosage in del(5q) patients (2.2 (CC), 1.3 (CG) and 0.89 years (GG)). Furthermore, C-allele homozygosity in del(5q) was associated with prolonged overall and progression-free survival and non-terminal interstitial deletions that excluded 5q34, whereas G-allele homozygozity was associated with inferior outcome and terminal deletions involving 5q34 (P=0.05). These findings comprise the largest MDS R72P SNP analysis.

Dual infection with Pneumocystis carinii and respiratory viruses complicating bone marrow transplantation.

Pneumonia due to dual infection with Pneumocystis carinii and respiratory viruses is a rare but formidable complication of bone marrow transplantation. We report here two cases of viral infections complicating P. carinii pneumonia in bone marrow transplant recipients who, at the time of infection, were not taking P. carinii prophylaxis. Both patients died following the pneumonia. Potential factors contributing to the dual infection included graft-versus-host disease, high-dose steroids and cyclosporin A. P. carinii prophylaxis should be continued for 12 months, or longer in bone marrow transplant recipients requiring prolonged immunosuppressive therapy. As specific antiviral therapy becomes available for some respiratory viral infections, performing regular viral surveillance cultures and responding with active early treatment may help improve the outcome in these immunocompromised patients.

Potential role of IgG avidity for diagnosing toxoplasmosis.

Sera from 20 cases of toxoplasmic lymphadenopathy were examined by an enzyme linked immunosorbent assay toxoplasma IgG avidity (ELISA) at two laboratories. The results obtained were largely in agreement and showed that sera from patients with acute infection had low avidity IgG (30% or less), whereas sera from patients with chronic infection had high avidity IgG (40% or more). It is suggested that this type of assay could have a useful complementary role in antenatal testing for toxoplasmosis.

Quantification of cytomegalovirus DNA in blood specimens from bone marrow transplant recipients by the polymerase chain reaction.

A nested PCR system for cytomegalovirus (CMV) DNA in blood specimens from bone marrow transplant recipients is described, in which the biotinylated tritium-labelled product from the second round of PCR is quantified using streptavidin-coated fluorometric Scintillation Proximity Assay (SPA) beads (Amersham, UK). This assay has been compared with a PCR procedure based on limiting-dilution, in which the end-point is determined visually following electrophoresis in agarose gel. The two systems were shown to be equivalent in sensitivity and specificity on testing stored serial blood samples from six CMV antibody-positive allogeneic bone marrow transplant patients who developed viraemia as detected by conventional methods of virus isolation in tissue culture.

A polymerase chain reaction to detect a spliced late transcript of human cytomegalovirus in the blood of bone marrow transplant recipients.

A reverse transcription (RT) nested polymerase chain reaction (PCR) procedure is described for detecting RNA to a spliced late gene (SLG) of human cytomegalovirus (CMV), the product of which (175 bp) is easily differentiated in agarose gels from the product when the target is unspliced viral RNA or DNA (258 bp). The SLG-RT-PCR has been compared against a semi-quantitative PCR for CMV DNA in buffy-coat specimens collected weekly after bone marrow transplantation from 3 patients and against the results of culturing these specimens for CMV both by conventional virus isolation, based on the detection of cytopathic effect, and by the early detection of infected cells by staining with virus-specific monoclonal antibodies. The detection of CMV RNA by SLG-RT-PCR correlated well with the detection of infective virus but only when the results of both culture methods were combined, in that neither culture method alone was as sensitive as the SLG-RT-PCR. The presence of SLG RNA in the circulation is of value as a marker of active CMV infection.

Capacity of Irpex lacteus and Pleurotus ostreatus for decolorization of chemically different dyes.

The rate and efficiency of decolorization of poly R-478- or Remazol Brilliant Blue R (RBBR)-containing agar plates (200 microg x g(-1)) were tested to evaluate the dye degradation activity in a total of 103 wood-rotting fungal strains. Best strains were able to completely decolorize plates within 10 days at 28 degrees C. Irpex lacteus and Pleurotus ostreatus were selected and used for degradation of six different groups of dyes (azo, diazo, anthraquinone-based, heterocyclic, triphenylmethane, phthalocyanine) on agar plates. Both fungi efficiently degraded dyes from all groups. Removal of RBBR, Bromophenol blue, Cu-phthalocyanine, Methyl red and Congo red was studied with I. lacteus also in liquid medium. Within 14 days, the following color reductions were attained: RBBR 93%, Bromophenol blue 100%, Cu-phthalocyanine 98%, Methyl red 56%, Congo red 58%. The ability of I. lacteus to degrade RBBR spiked into sterile soil was checked, the removal being 77% of the dye added within 6 weeks. The capacity of selected white rot fungal species to remove efficiently diverse synthetic dyes from water and soil environments is documented.

Potential metabolic mutagens of caffeine and various methylxanthines.

Xanthine N-carbinols, potential metabolites of caffeine and other methylxanthines, have been synthesized, characterized, and derivatized. Such intermediates, the initial metabolites arising from the cytochrome P-450 oxidation of the nitrogen-bound methyl groups, may be viewed as biological N-carbinols capable of alkylating proteins and nucleic acids. Evaluation of these compounds against Salmonella typhimurium, strain TA100, has demonstrated that, in contrast to caffeine, 7-hydroxymethyltheophylline and the 3,7-bis(hydroxymethyl)-1-methylxanthine mixture did exhibit cytotoxicity. There was no evidence of mutagenesis and it is possible that the Ames assay system is not applicable to N-carbinols.

An in vivo comparison of chlorhexidine and picloxydine mouthrinses: a possible association between chemical structure and antiplaque activity.

A double blind clinical trial was conducted in which both the plaque-inhibiting ability and the in vivo effects on the oral flora of chlorhexidine and picloxydine mouthwashes was compared. While picloxydine in higher concentration suppressed the oral flora more effectively than chlorhexidine, the latter agent inhibited plaque development to a much greater extent. This lack of correlation between antibacterial and antiplaque activity can be related to structural differences between these two bis-biguanides.

An investigation on the effect of groove geometry on cementless femoral stem component in hip arthroplasty.

The optimal surface for a cementless femoral stem has been a subject of debate for the past several years. Several researchers have stressed the need for research on how an implant surface shape contributes to long-term stability after implantation, in the field of orthopaedics. The introduction of optimized grooves on an implant proximal surface may enhance long-term stability of an implant. This study thus analyzes the effect of different groove dimensions and angles in a transverse plane on stress transmission by a constant load at the femur by using Finite Element Analysis (FEA). Results suggest that the tendency of stress transmission differs depending on the size, position and angle of the grooves. An optimized groove size and inclination plays a vital role for long-term stability of cementless femoral stems.

A Systematic Review and Meta-analysis of Prophylactic versus Pre-emptive Strategies for Preventing Cytomegalovirus Infection in Renal Transplant Recipients.

BACKGROUND: In kidney transplant (KT) recipients, CMV infection poses significant morbidity and mortality. Both prophylactic and pre-emptive approaches for preventing CMV infection have been utilized. OBJECTIVE: To compare the effectiveness of routine prophylaxis vs. pre-emptive treatment for preventing CMV disease after KT. METHODS: We conducted a systematic review and meta-analysis comparing the effectiveness of routine prophylaxis vs. pre-emptive treatment for preventing CMV disease after KT. Combining 4 comprehensive search terms (CMV, renal transplant, prophylaxis, pre-emptive); we searched PubMed, EMBASE, ISI Web of Science, and Cochrane Central Register from inception through January 2011. We also evaluated studies referenced in review articles and abstracts from meetings of major nephrology and transplant societies (2009-2011). Two authors independently extracted data and assessed methodological criteria. The primary outcome was the pooled estimate of the odds ratio (OR) of developing CMV infection. Secondary outcomes included OR of acute rejection, OR of graft loss and OR of death within first year of KT. Comprehensive Meta-analysis V2 software was used for data analysis. RESULTS: Analysis of 9 randomized controlled trials (991 patients; ganciclovir=5, valganciclovir=4) with CMV infection as an outcome revealed the OR of CMV infection to be 0.34 (95% CI: 0.25-0.46, p=0.008) for the prophylactic vs. the pre-emptive groups. The OR of acute rejection (7 studies; 1358 patients) was 0.52 (95% CI: 0.41-0.67, p=0.001) with prophylactic approach compared to pre-emptive treatment; graft loss (7 studies; OR 0.52 [95% CI: 0.34-1.12, p=0.32] and mortality (6 studies; OR 0.84 [95% CI: 0.62-1.23, p=0.23]) were similar between the two groups. CONCLUSIONS: Prophylactic approach is superior to pre-emptive approach in preventing CMV infection within the first year of kidney transplant. The risk of developing acute rejection is also lower with prophylactic approach in the first year of transplant but there is no significant difference in graft loss or mortality with either approach.

Bactericidal action of ascorbic acid on Psuedomonas aeruginosa: alteration of cell surface as a possible mechanism.

Neutralised ascorbic acid is found to exert a strong bactericidal action on Pseudomonas aeruginosa suspended in isotonic phosphate buffer at pH 7.1. Both the bactericidal and bacteriostatic action of ascorbic acid are antagonised by magnesium ions. In the absence of complex formation between magnesium and ascorbic acid it is concluded that ascorbic acid acts by competing with the magnesium binding sites in the cell wall, cell membrane or ribosomes. Using the chequer-board titration method the synergistic action of ascorbic acid and erythromycin is determined; such a potentiation of erythromycin is also adversely affected by magnesium ions. P. aeruginosa cells, washed and suspended in isotonic phosphate buffer containing ascorbic acid, became increasingly susceptible to the action of polymyxin, erythromycin, chloramphenicol, neomycin and tetracycline. It is suggested that ascorbic acid alters the cell surface to render it increasingly permeable to these antibiotics.