A bacterial sense of touch: T4P retraction motor as a means of surface sensing by Pseudomonas aeruginosa PA14.

Most microbial cells found in nature exist in matrix-covered, surface-attached communities known as biofilms. This mode of growth is initiated by the ability of the microbe to sense a surface on which to grow. The opportunistic pathogen Pseudomonas aeruginosa (Pa) PA14 utilizes a single polar flagellum and type 4 pili (T4P) to sense surfaces. For Pa, T4P-dependent "twitching" motility is characterized by effectively pulling the cell across a surface through a complex process of cooperative binding, pulling, and unbinding. T4P retraction is powered by hexameric ATPases. Pa cells that have engaged a surface increase production of the second messenger cyclic AMP (cAMP) over multiple generations via the Pil-Chp system. This rise in cAMP allows cells and their progeny to become better adapted for surface attachment and activates virulence pathways through the cAMP-binding transcription factor Vfr. While many studies have focused on mechanisms of T4P twitching and regulation of T4P production and function by the Pil-Chp system, the mechanism by which Pa senses and relays a surface-engagement signal to the cell is still an open question. Here we review the current state of the surface sensing literature for Pa, with a focus on T4P, and propose an integrated model of surface sensing whereby the retraction motor PilT senses and relays the signal to the Pil-Chp system via PilJ to drive cAMP production and adaptation to a surface lifestyle.

Cross-border reproductive care use by women with infertility in Hong Kong: cross-sectional survey.

OBJECTIVES: Cross-border reproductive care (CBRC) is an increasingly common global phenomenon, but there is a lack of information regarding its frequency among residents of Hong Kong. This study aimed to evaluate the use of CBRC and the factors affecting its use among residents of Hong Kong. METHODS: This cross-sectional questionnaire study collected data from 1204 women with infertility who attended Hong Kong Hospital Authority and Family Planning Association infertility clinics. RESULTS: In total, 178 women (14.8% of all respondents) had used CBRC. Among respondents who had not used CBRC, 36.3% planned to use or would consider it. The main factors influencing the likelihood of using CBRC among women with infertility in Hong Kong use were long waiting times in the public sector and high cost in the private sector. Taiwan was the most preferred destination for CBRC (69.6% of respondents). Most information concerning CBRC was accessed via the internet. More than two thirds of respondents believed that the government in Hong Kong should formulate some regulations or guidance regarding CBRC. CONCLUSION: Nearly one in six women with infertility in Hong Kong had used CBRC. Among women who had not used CBRC, more than one third planned to use or would consider it. The main factors influencing the likelihood of CBRC use were long waiting times in the public sector and high cost in the private sector. These results will help clinicians to more effectively counsel patients considering CBRC and facilitate infertility services planning by authorities in Hong Kong.

Infection control in residential care homes for the elderly in Hong Kong (2005-2014).

INTRODUCTION: This serial cross-sectional survey study aimed to review the trend in various infection control practices in residential care homes for the elderly (RCHEs) in Hong Kong from 2005 to 2014. METHODS: Annual cross-sectional surveys were conducted at all RCHEs in Hong Kong, including self-administered questionnaires, on-site interviews, inspections, and assessments conducted by trained nurses, from 2005 to 2014. In all, 98.5% to 100% of all RCHEs were surveyed each year based on the list of licensed RCHEs in Hong Kong. RESULTS: There was a substantial increase in the proportion of RCHE residents aged ≥85 years, from 40.0% in 2005 to 50.2% in 2014 (P=0.002). The percentage of RCHE residents with special care needs also increased, from 22.3% in 2005 to 32.6% in 2014 for residents with dementia (P<0.001) and from 3.4% in 2005 to 5.0% in 2014 for residents with a long-term indwelling urinary catheter (P<0.001). The proportion of RCHEs with separate rooms for isolation areas ranged from 73.6% to 80% but did not show any significant trend over the study period. The proportion of RCHEs with alcohol hand rub available showed an increasing trend from 25.4% in 2006 to 99.2% in 2014 (P=0.008). The proportion of health or care workers (who were not the designated infection control officers) passing skills tests on hand washing techniques increased from 79.2% in 2006 to 91.5% in 2014 (P=0.02). An increasing trend was also observed for the proportion of infection control officers who were able to prepare properly diluted bleach solution, from 71.5% in 2005 to 92.2% in 2014 (P=0.002). CONCLUSIONS: For infection control practice to continue improving, more effort should be made to enhance and maintain proper practice, and to mitigate the challenge posed by the high turnover rates of healthcare workers in RCHEs. Introduction of self-audits on infection control practices should be considered.

Leukaemic transformation of Philadelphia chromosome-negative myeloproliferative neoplasms: are Asian patients different?

BACKGROUND: Leukaemic transformation (LT) is rare in the natural history of Philadelphia(Ph) chromosome-negative myeloproliferative disorders (MPD), and has a dismal prognosis. Little literature is available on Asian patients. AIMS: The aim of this study is to report a single institution experience of Asian patients who developed acute leukaemia after being diagnosed and treated for Ph chromosome-negative MPDs, and to compare the findings of this series with similar studies from the literature. METHODS: Patients were recruited from the MPD registry of Singapore General Hospital, Department of Hematology. Clinical data including treatment modalities and duration of use in myeloproliferative phase, latency to LT, characteristics of leukaemia, chemotherapy administered and survival after LT were examined. RESULTS: Over a 29-year period from 1980 to 2009, there were 22 Asian patients with LT of Ph chromosome-negative MPD of which four had polycythaemia vera (PV), nine had essential thrombocythaemia (ET), seven had myelofibrosis (MF) and two had unspecified MPD at diagnosis. Primary treatment modality was Hydroxyurea (HU) during MPD phase. Median latency to LT was 14 years for PV, 10 years for ET and 1 year for MF. Median age at LT diagnosis was 67.5 years. Nine patients had complex cytogenetics, with abnormalities of chromosomes 5 and 7 being common. Overall, median survival was 2 months after LT. Eight patients who received induction chemotherapy had a median survival of 2.5 months. Survival was independent of MPD type and treatment administered. None received stem cell transplantation. CONCLUSIONS: LT of Ph chromosome-negative MPD is rare and uniformly fatal. Despite chemotherapy, survival was poor, and patients succumbed to refractory disease and infections. Asian patients did not have a more favourable outcome. It remains to be investigated whether upfront stem cell transplant may be a treatment option.

Operational definitions improve reliability of the age-related white matter changes scale.

BACKGROUND AND PURPOSE: Although the age-related white matter changes (ARWMC) scale has been advocated to be applicable to both MRI and CT for assessing the severity of WMC, its inter-rater reliability on CT is only fair. We aimed to operationalize the ARWMC scale and investigate the effect of this operationalization on the reliability and validity on MRI and CT. METHODS: Operational definitions of the ARWMC scale were derived from Erkinjuntti research criteria for subcortical vascular dementia and Scheltens scale. Using original and operationalized ARWMC scale, eight observers recorded the time for rating per MRI and per CT. We investigated the inter-rater and intrarater reliability as well as validity against volume using data from 97 stroke patients. RESULTS: Inter-rater reliability of the operationalized scale on CT (0.874, 95% confidence interval [0.780-0.934]) was better than the original scale (0.569, 95% confidence interval [0.247-0.775]). Its intrarater reliability on CT (0.869) and reliability on MRI (inter-rater: 0.860; intrarater: 0.838) was comparable with the original scale (CT intrarater: 0.750 and on MRI inter-rater: 0.845; intrarater: 0.853). The time required to administer the operationalized scale (4'2″ for MRI and 1'18″ for CT) was similar to that of the original scale (3'56″ for MRI and 1'16″ for CT). The original scale and operationalized scale also significantly correlated with WMC volume (operationalized scale ρ = 0.613, P < 0.001, original scale ρ = 0.638, P < 0.001). CONCLUSION: Operational definitions improve the inter-rater reliability of ARWMC scale on CT, and it correlates with volumetric measurement.

JAK2 mutations in Asian patients with essential thrombocythaemia.

BACKGROUND/AIM: JAK2V617F is an acquired mutation present in a considerable proportion of patients with chronic myeloproliferative disorders. Its reported prevalence in European and US studies of patients with essential thrombocythaemia (ET) is 23-57%. This study was conducted to determine the prevalence of the JAK2 mutation in Asian ET patients, and to examine their disease profile. METHODS: Asian patients with ET were either recruited to the study or registry data were analysed retrospectively. Blood samples were collected for analysis of JAK2 mutation status during routine patient follow up. Clinical data on these patients (including demographics and disease profiles) and complications at diagnosis were recorded. RESULTS: The JAK2 mutation was detected in 35/102 (34%) patients. Females were more likely than males to have JAK2 mutation (P = 0.031). At diagnosis, JAK2-mutated patients were found to be older (P = 0.012), have higher leucocyte counts (P = 0.036) and high-risk disease (P = 0.039). There were no other statistically significant differences between mutated and wild-type JAK2 ET patients. CONCLUSION: The prevalence of JAK2 mutations in this population of Asian ET patients was 34%. Patients with the JAK2 mutation were significantly more likely to have high-risk disease. Further studies are required to assess the role of JAK2 mutations in risk stratification in ET and compare the phenotype of Asian patients with other populations.

Attainment of at least a very good partial response after induction treatment is an important surrogate of longer survival for multiple myeloma.

The importance of achieving a very good partial response or better (≥VGPR) after induction treatment of myeloma has traditionally only been discussed in the context of high-dose therapy with auto-SCT (HDT/auto-SCT). Of late, the advent of novel agents for induction treatment has resulted in improved CR and VGPR rates, which are comparable with those observed with HDT/auto-SCT. We show that in an unselected group of 179 myeloma patients with diverse baseline characteristics, and treated with different modern induction regimens within a single institution, the attainment of ≥VGPR with or without HDT/auto-ASCT represents a major surrogate marker of better clinical outcomes. On the basis of a 1-year landmark survival analysis, patients achieving ≥VGPR enjoy a significantly longer PFS, which translated to a longer OS. Superseding the adverse effects of advanced age, high International Staging System (ISS) stage, adverse cytogenetics and independent of the transplant status, the attainment of ≥VGPR emerged as the single most significant predictor of long-term survival on multivariate analysis.

Temporal trends in the use of invasive cardiac procedures for non-ST segment elevation acute coronary syndromes according to initial risk stratification.

BACKGROUND: Current guidelines support an early invasive strategy in the management of high-risk non-ST elevation acute coronary syndromes (NSTE-ACS). Although studies in the 1990s suggested that highrisk patients received less aggressive treatment, there are limited data on the contemporary management patterns of NSTE-ACS in Canada. OBJECTIVE: To examine the in-hospital use of coronary angiography and revascularization in relation to risk among less selected patients with NSTE-ACS. METHODS: Data from the prospective, multicentre Global Registry of Acute Coronary Events (main GRACE and expanded GRACE2) were used. Between June 1999 and September 2007, 7131 patients from across Canada with a final diagnosis of NSTE-ACS were included the study. The study population was stratified into low-, intermediate- and high-risk groups, based on their calculated GRACE risk score (a validated predictor of in-hospital mortality) and according to time of enrollment. RESULTS: While rates of in-hospital death and reinfarction were significantly (P<0.001) greater in higher-risk patients, the in-hospital use of cardiac catheterization in low- (64.7%), intermediate- (60.3%) and highrisk (42.3%) patients showed an inverse relationship (P<0.001). This trend persisted despite the increase in the overall rates of cardiac catheterization over time (47.9% in 1999 to 2003 versus 51.6% in 2004 to 2005 versus 63.8% in 2006 to 2007; P<0.001). After adjusting for confounders, intermediate-risk (adjusted OR 0.80 [95% CI 0.70 to 0.92], P=0.002) and high-risk (adjusted OR 0.38 [95% CI 0.29 to 0.48], P<0.001) patients remained less likely to undergo in-hospital cardiac catheterization. CONCLUSION: Despite the temporal increase in the use of invasive cardiac procedures, they remain paradoxically targeted toward low-risk patients with NSTE-ACS in contemporary practice. This treatment-risk paradox needs to be further addressed to maximize the benefits of invasive therapies in Canada.

The effect of topical lignocaine gel in pain relief for colposcopic assessment and biopsy: is it useful?

We investigated the use of topical ligocaine gel in pain relief for colposcopy and cervical punch biopsy. Ninety women referred for colposcopy due to abnormal cervical cytology were randomised to receive 5 ml of either 2% xylocaine gel or KY jelly to the cervix and the upper part of the vagina for at least 10 minutes prior to the colposcopic procedures. Pain score was obtained at several points of the procedure. Topical lignocaine gel did not significantly relieve pain from cervical punch biopsy and alleviate the stinging sensation from application of acetic acid and Lugol's iodine to cervix and vagina. However, it may be beneficial to a subgroup of women with prior unpleasant experience towards speculum examination.

Successful treatment of primary granulocytic sarcoma by non-myeloablative stem cell transplant.

Pre-leukemic granulocytic sarcoma (GS) may pose an initial diagnostic problem and its therapeutic approach has never been formally established. To our knowledge, non-myeloablative stem cell transplantation has been reported in cases of leukemic GS, but not in primary GS. We report a case of primary GS with extensive and aggressive presenting features and successfully treated with intensive chemotherapy followed by non-myeloablative allogeneic stem cell transplant. This resulted in complete remission with minimal complications. Our case demonstrates the potential of graft-vs.-tumour effect in the treatment of GS and suggests that non-myeloablative allogeneic stem cell transplant may be a feasible therapeutic approach for primary GS.

Direct observation of counterion organization in F-actin polyelectrolyte bundles.

Attractions between like-charged polyelectrolytes have been observed in a variety of systems (W.M. Gelbart, R.F. Bruinsma, P.A. Pincus, V.A. Parsegian, Phys. Today 53, September issue, 38 (2000)). Recent biological examples include DNA, filamentous viruses, and F-actin. Theoretical investigations on idealized systems indicate that counterion correlations play a central role, but no experiments that specifically probe such correlations have been performed. Using synchrotron X-ray diffraction, we have directly observed the organization of multivalent ions on cytoskeletal filamentous actin (a well-defined biological polyelectrolyte) and found an unanticipated symmetry-breaking collective counterion mechanism for generating attractions. Surprisingly, the counterions do not form a lattice that simply follows actin's helical symmetry; rather, the counterions organize into "frozen" ripples parallel to the actin filaments and form structures reminiscent of charge density waves. Moreover, these 1D counterion charge density waves form a coupled mode with twist deformations of the oppositely charged actin filaments. This counterion organization is not sensitive to thermal fluctuations in temperature range accessible to protein-based polyelectrolyte systems. Moreover, the counterion density waves are "pinned" to the spatial periodicity of charges on the actin filament even if the global filament charge density is varied, indicating the importance of charge periodicity on the polyelectrolyte substrate.

MARS therapy in critically ill patients with advanced malignancy: a clinical and technical report.

BACKGROUND/METHODS: Molecular Adsorbent Recirculating System (MARS) was used in three consecutive critically ill patients at the Singapore General Hospital with advanced malignancy and acute liver failure (ALF). Case 1 was a male patient with hepatocellular carcinoma (HCC) for which initial right hepatectomy was followed by left hepatectomy 5 months later for recurrent HCC. The postoperative course following second surgery was complicated by severe methicillin-resistant Staphylococcus aureus (MRSA) sepsis, mild azotaemia and subacute cholestatic liver failure. MARS was used thrice in this patient. Case 2 was a female patient with advanced acute lymphoblastic leukaemia (ALL) with post bone marrow transplantation (BMT) acute haemolytic-uraemic syndrome (HUS) secondary to cyclosporin A (Cy A), cytomegalovirus (CMV) infection, severe nosocomial pneumonia, acute renal failure (ARF) treated with continuous haemofiltration and acute veno-occlusive disease resulting in Budd-Chiari syndrome. The latter precipitated ALF. MARS was instituted twice. Case 3 was a male patient with advanced, refractory Hodgkin's disease previously treated with multiple courses of chemotherapy. ALF developed secondary to acute viral hepatitis B flare. He was given a trial of MARS once in the ICU. All the three patients eventually died. RESULTS: Mean MARS intradialytic systemic pressures were as follows: systolic pressure range was 95 +/- 17 to 128 +/- 17 mmHg and diastolic pressure range was 51 +/- 5 to 67 +/- 7 mmHg. Pressure at albumin dialysate exit point from dialyser 1 (Ae) ranged from 253 +/- 11 to 339 +/- 15 mmHg and that at albumin dialysate entry point into dialyser 1 (Aa) ranged from 142 +/- 11 to 210 +/- 6 mmHg. Ultrafiltration (UF) was 633 +/- 622 mL over mean treatment duration of 6.3 +/- 0.9 h with a total heparin dose of 1583 +/- 817 IU. Coagulation status pre- and 6-h post-MARS was similar: aPTT (P=0.116) and platelet count (P=0.753). There were no bleeding complications or circuit thromboses. MARS had a significant de-uraemization effect (pre- and post-MARS serum creatinine and urea: P=0.046 and 0.028, respectively) but did not significantly attenuate blood lactate, ammonia or total bilirubin levels. Albumin dialysate (Ae - Aa) urea and creatinine concentrations appeared to be sharply attenuated after 6 h of MARS. In contrast, the removal of total bilirubin by albumin dialysate from the blood compartment appeared to plateau after 4 h of continuous MARS operation. CONCLUSIONS: MARS was well-tolerated in critically ill patients with advanced and complicated cancer. Low-dose heparin was safe and did not compromise MARS circuit integrity. Although MARS had a significant de-uraemization effect, this appeared to be limited by the duration of MARS operation. Our data suggested that such a limit was reached earlier for total bilirubin. More data are needed to confirm the present findings and further delineate the saturation limit of MARS for different toxins that accumulate in ALF. This would affect the optimal duration of MARS therapy.

Management of haematologic malignancies in pregnancy.

INTRODUCTION: Malignancy complicates about 1 in 1000 pregnancies and is the second leading cause of death in women of reproductive age. Commonly diagnosed malignancies during pregnancy include breast cancer, cervical carcinoma, melanoma and lymphoma. Chemotherapy is usually necessary for optimal treatment, especially in patients with leukaemia and lymphoma. Concerns arise regarding the effects of imaging modalities in the pregnant cancer patients and the effects of chemotherapeutic agents on the developing fetus. METHODS: A Medline search of articles describing haematologic malignancies in pregnant patients was performed. Particular attention was paid to the kind of malignancy, stage of pregnancy, the types and side effects of chemotherapeutic agents used and the outcome of the pregnancy. RESULTS: There is no entirely safe cytotoxic drug or timing of exposure for the developing fetus. The administration of chemotherapy during pregnancy will not always produce a poor outcome. A pregnant cancer patient can also be safely and reasonably staged with imaging. Magnetic resonance imaging will most often be the procedure of choice as it does not use ionising radiation. CONCLUSIONS: The management of each pregnant patient diagnosed with a malignancy has to be highly individualized and involves a multidisciplinary team of medical personnel. The patient and her family need counselling regarding the diagnosis, long-term prognosis, options of termination of pregnancy, choice of chemotherapeutic agents and their effects on the fetus and pregnancy.

Capacity building to improve women's health in rural China.

The Women's Reproductive Health and Development Program (WRDHP) is an ambitious attempt to operationalize two important tenets of health development thinking within a rural reproductive health context. First, it is important for communities to participate in decisions about the services and programs that affect them. Secondly, the complex nature of healthcare is best addressed by intervention processes which call for a multi-functional approach to planning and coordination. In both planning and intervention approach, the WRHDP recognizes the social, cultural and economic realities that affect women's efforts to secure the health and well-being of themselves and their families. The focus of the WRHDP is on capacity-building within a rural reproductive health environment, in this case Yunnan Province in rural China. Rather than using international donor funding to provide a specific intervention, the WRDHP used Ford Foundation funding as a lever to encourage community investment in environmental resources that affect health, to improve the technical skills of individuals within the existing health bureaucracies, and to promote structural changes within existing health and development bureaucracies to support interagency collaboration and community empowerment within the region's health and development agencies. This article describes how the WRHDP created new methods for provincial and local agencies to overcome obstacles and work with one another to improve women's health. It also describes the processes used in the rural areas of Chengjiang and Luliang counties to assess local conditions and needs, and the supported and expanded local efforts in improving woman's reproductive and family health that resulted from the processes.

CT findings after uterine artery embolization.

Asymptomatic uterine leiomyoma can be detected on routine computed tomography (CT) of the pelvis. Leiomyomas have been described as low attenuation masses that can disrupt the smooth contour of a normal uterus. Four women underwent uterine artery embolization for the treatment of uterine leiomyoma. CT findings include initial retention of contrast in fibroids the day of the procedure and central necrosis of the fibroid with subsequent cavitation as early as 1 month postprocedure.

Retrieval of a Greenfield IVC filter displaced to the right brachiocephalic vein.

During insertion of a central venous sheath an inferior vena cava stainless steel Greenfield filter was dislodged to the right brachiocephalic vein without a free end. Successful retrieval was achieved by using a combination of a guidewire and a snare. Percutaneous retrieval of this vena cava filter is feasible with minimal risk using this method.

Percutaneous delivery of a heparin-impregnated collagen stent-graft in a porcine model of atherosclerotic disease.

RATIONALE AND OBJECTIVES: To develop collagen stent-grafts impregnated with heparin to improve the biocompatibility of endovascular stents and to design a percutaneous delivery system for graft deployment in a swine model. METHODS: Heparin-impregnated collagen stent-grafts were deployed, and follow-up angiograms were obtained every 15 minutes for 90 minutes to assess acute thromboses and again at 2 and 4 weeks afterward to assess patency. If stenosis or occlusion was detected at the 2-week evaluation, guidewire passage across the lesion was attempted and angioplasty was performed. If stenosis or occlusion was present at the 4-week evaluation, only guidewire passage was attempted; thereafter, the animals were killed and the stent-grafts were harvested and reviewed by a vascular pathologist. RESULTS: Group A represents a feasibility study to optimize the deployment method applied in groups B and C. Fifteen of 17 stent-grafts were successfully deployed using this method. In group B, 89% of grafts were successfully deployed; 12% were patent at 2 weeks and none at 4 weeks. In group C, a 10-minute inflation time was added to the deployment procedure; 88% of grafts were successfully deployed and 28% were patent at 2 weeks and 14% at 4 weeks. Extensive luminal thrombosis and myointimal hyperplasia were present in every case. CONCLUSIONS: A method was developed for percutaneous implantation of collagen stent-grafts into peripheral vessels. The heparin-impregnated grafts did not prevent vessel restenosis. Modification of the graft-processing technique may improve patency.

Uterine artery embolization: a minimally invasive technique for the treatment of uterine fibroids.

Uterine artery embolization (UAE) as a primary therapy for symptomatic fibroids was first used in France in 1991. Currently, there are at least 250 centers in the United States, as well as centers in Canada and England, with experience in this technique. Initial published results worldwide indicate that after UAE, uterine fibroids shrink at least 50% in volume on average and symptoms of refractory vaginal bleeding and chronic pelvic pain are controlled in approximately 85% of patients. Major complications are rare. Overall, this technique is minimally invasive, preserves the uterus, and requires a shorter hospitalization than hysterectomy or myomectomy.

Hierarchical self-assembly of F-actin and cationic lipid complexes: stacked three-layer tubule networks.

We describe a distinct type of spontaneous hierarchical self-assembly of cytoskeletal filamentous actin (F-actin), a highly charged polyelectrolyte, and cationic lipid membranes. On the mesoscopic length scale, confocal microscopy reveals ribbonlike tubule structures that connect to form a network of tubules on the macroscopic scale (more than 100 micrometers). Within the tubules, on the 0.5- to 50-nanometer length scale, x-ray diffraction reveals an unusual structure consisting of osmotically swollen stacks of composite membranes with no direct analog in simple amphiphilic systems. The composite membrane is composed of three layers, a lipid bilayer sandwiched between two layers of actin, and is reminiscent of multilayered bacterial cell walls that exist far from equilibrium. Electron microscopy reveals that the actin layer consists of laterally locked F-actin filaments forming an anisotropic two-dimensional tethered crystal that appears to be the origin of the tubule formation.