Ptychographic coherent diffractive imaging with orthogonal probe relaxation.

Ptychography is a scanning coherent diffractive imaging (CDI) technique that relies upon a high level of stability of the illumination during the course of an experiment. This is particularly an issue for coherent short wavelength sources, where the beam intensity is usually tightly focused on the sample in order to maximize the photon flux density on the illuminated region of the sample and thus a small change in the beam position results in a significant change in illumination of the sample. We present an improved ptychographic method that allows for limited stability of the illumination wavefront and thus significantly improve the reconstruction quality without additional prior knowledge. We have tested our reconstruction method in a proof of concept experiment, where the beam instability of a visible light source was emulated using a piezo driven mirror, and also in a short wavelength microscopy CDI setup using a high harmonic generation source in the extreme ultraviolet range. Our work shows a natural extension of the ptychography method that paves the way to use ptychographic imaging with any limited pointing stability coherent source such as free electron or soft X-ray lasers and improve reconstruction quality of long duration synchrotron experiments.

Cardiovascular disease (CVD) in Canadians with haemophilia: Age-Related CVD in Haemophilia Epidemiological Research (ARCHER study).

INTRODUCTION: Improvements in haemophilia care have increased life expectancy in persons with haemophilia (PWH). This ageing population presents clinicians with management challenges as they develop age-related comorbidities such as cardiovascular disease (CVD). AIMS: To assess the epidemiology of CVD risk factors and events in an ageing Canadian haemophilia population. METHODS: A retrospective, multicentre chart review was carried out at five Canadian Hemophilia Treatment Centres. PWH (A and B) ≥35 years old were included and data were extracted on CVD risk factors and events. RESULTS: Data from 294 patients' charts were analysed including 222 (75.5%) patients with haemophilia A and 72 (24.5%) patients with haemophilia B with a median age at end of follow-up of 54 years (range = 36-90). Mean follow-up duration was 5.86 years. Cardiovascular risk factors were common: hypertension 31.3% (n = 90), diabetes mellitus 10.5% (n = 29), smoking 21.8% (n = 61), obesity 27.6% (n = 69), dyslipidaemia 22.4% (n = 65), family history 8.5% (n = 24), antiretroviral therapy 12.2% (n = 36). There were 24 CVD events (8.2% of the population) with a median age at event of 63 years (range = 46-83). Events consisted of coronary artery disease (CAD), 14; cerebrovascular disease, 4; and atrial fibrillation, 7. CAD was treated with coronary artery bypass grafting in three patients and percutaneous coronary intervention in nine patients. CVD events were complicated by six bleeding events (three minor and three major). CONCLUSION: Cardiovascular disease risk factors and events are relatively common in PWH. PWH can be safely treated for CVD events with similar procedures as the non-PWH populations, though specific clotting factor prophylaxis protocols are not well defined.

Experience with central venous access devices (CVADs) in the Canadian hemophilia primary prophylaxis study (CHPS).

INTRODUCTION: Haemophilia A treatment with factor VIII concentrates requires frequent venipunctures; a central venous access device (CVAD) may be required to facilitate reliable venous access, especially in young children. While CVADs provide reliable venous access, complications such as infection and thrombosis may occur. AIM: The aim of this study was to assess CVAD use in the Canadian Hemophilia Primary Prophylaxis Study (CHPS), a single-arm, multi-centre prospective study whereby factor use is tailored to individual prophylactic need. METHODS: Participants received a tailored, escalating dose, prophylaxis regimen of increasing frequency of FVIII infusions: step-1: 50 IU kg(-1) once weekly; step-2: 30 IU kg(-1) twice weekly; and step-3: 25 IU kg(-1) on alternate days, according to their level of bleeding. CVAD insertion was at the discretion of the local health care team. Details regarding CVAD use during this protocol were analysed. RESULTS: Fifty six boys were enrolled, 21 required 25 CVADs due to difficult venous access. CVADs were inserted at a median age of 1.3 years (range: 0.6-2.1) and were removed at a median age of 8.7 years (range 6.3-11.8). Six participants experienced non-life threatening CVAD-complications, the most frequent being device malfunction requiring CVAD replacement (n = 4). Two boys were shown to have CVAD-associated thrombosis detected on routine imaging; one required removal due to infusion difficulties and the other was asymptomatic and did not require device removal. No CVAD-related infections were documented. CONCLUSION: Our study shows that the CHPS tailored prophylaxis regimen is associated with a decreased requirement for CVADs and with few device-related complications.

Patterns of tertiary prophylaxis in Canadian adults with severe and moderately severe haemophilia B.

From a young age patients with severe and moderately severe FIX deficiency (haemophilia B) can experience spontaneous or traumatic bleeding and joint destruction may result. The use of coagulation factor IX concentrate to prevent anticipated bleeding, as primary or secondary prophylaxis, has become a common and recommended practice in children. The current practice of using tertiary prophylaxis, in the presence of established joint arthropathy, in adults with haemophilia B is not well characterized. This observational study was conducted to gain a better understanding of the recent Canadian experience with tertiary prophylaxis in adults with severe and moderately severe haemophilia B. Data were collected from all eligible adult (≥ 18 years of age) males with baseline FIX:C ≤ 2% from seven Canadian Hemophilia Treatment centres over a 2-year observation period from 2009 to 2011. Thirty-four per cent of the 67 subjects with moderately severe haemophilia B were exposed to prophylaxis with the majority as continuous prophylaxis (≥45 weeks year(-1) ). The severe subgroup (FIX:C < 1%) demonstrated a 52% exposure rate. None had primary prophylaxis exposure in childhood. Eighty-one per cent used once or twice weekly infusion regimens and reported a median annual bleeding rate of five bleeds per year versus four bleeds per year for those using on-demand treatment. Annual median factor utilization for all subjects using prophylaxis was 196,283 U year(-1) compared to 46,361 U year(-1) for on demand. Approximately 50% of adults with severe haemophilia B are using continuous tertiary prophylaxis in Canada, a practice likely to increase which warrants further study.

Suspected collagen disorders in the bleeding disorder clinic: a case-control study.

Disorders of collagen are associated with a mild bleeding tendency because of the potential abnormal interaction of collagen, von Willebrand factor (VWF) and platelets required during primary haemostasis and due to generalized soft tissue fragility. Abnormal collagen may contribute to bleeding in existing mucocutaneous bleeding disorders, but the prevalence in this setting is unknown. Generalized symptomatic joint hypermobility (SJH) is common in collagen disorders and may be objectively measured. To assess the association between symptomatic joint hypermobility and mucocutaneous bleeding disorders, we performed a case-control study in which case subjects were 55 consecutive individuals who had visited our bleeding disorder clinic with a diagnosis of von Willebrand disease, low von Willebrand factor levels, mild platelet function disorder or undefined bleeding disorder. Controls were 50 subjects without a bleeding disorder, and were age and gender matched to the cases. All subjects were assessed with: (i) Beighton score for joint hypermobility, (ii) revised Brighton criteria, (iii) Condensed MCMDM1-VWD bleeding questionnaire, and (iv) haemostasis laboratory studies. The prevalence of SJH/suspected collagen disorder in the bleeding disorder clinic was 24% (13/55) compared with 2% (1/50) in the control population (OR 15, 95% CI 2-121). Seventy-seven per cent of bleeding disorder clinic SJH subjects (10/13) had a prior personal or family history of Ehlers-Danlos, Benign Joint Hypermobility Syndrome or Osteogenesis Imperfecta (OI). Symptomatic joint hypermobility was associated with increased odds of an underlying mucocutaneous bleeding disorder. These findings suggest that a collagen disorder is common and often unrecognized in the bleeding disorder clinic as a potential contributor to the bleeding symptoms.

Antibiotic resistance gene profiling of faecal and oral anaerobes collected during an antibiotic challenge trial.

Here we describe a study examining the antibiotic resistance gene carriage in anaerobes collected during a clinical study. The results demonstrated that genes normally associated with anaerobes were most prevalent such as tetQ, cepA and cblA although several genes associated with Enterobacteriaceae including sul2, blaSHV and strB were also detected.

Generational differences in factors influencing physicians to choose a work location.

INTRODUCTION: Canadian medical schools have increased enrolment and recruited more rural students in an effort to address general and rural physician shortages. The success of this approach depends on the recruitment of these newly trained physicians to under-serviced areas. Studies from North America suggest that the career expectations and practice patterns of younger, more recently graduated physicians differ from those of their older counterparts. This study explored the factors that influenced the work location choices of physicians of differing generations, who trained at universities in Saskatchewan, and Newfoundland and Labrador, two Canadian provinces with large rural populations and no community larger than 235 000 population. METHODS: Semi-structured, qualitative interviews were conducted with physicians who graduated from either the Memorial University of Newfoundland or the University of Saskatchewan. Generation definitions were based on the graduation year. Early-career physicians graduated between 1995 and 1999; mid-career physician graduated between 1985 and 1989; late-career physicians graduated between 1975 and 1979; and end-career physicians graduated between 1965 and 1969. Each physician was asked questions about the number and nature of work location changes over the course of their careers and the factors related to their decision to choose each location. Interview transcripts and notes were analyzed using a thematic analysis approach. Although the study focus was on generational differences, similarities and differences between universities, sexes and specialties (family physicians/GPs vs specialists) were also examined. Recruitment to the provinces was focused on as a whole, because the largest communities in the provinces are small compared with most urban communities. RESULTS: Forty-eight physicians were interviewed, five to nine physicians who graduated in each decade and from each university. The desire to be near family and friends was cited as the primary consideration when choosing a work location, regardless of generation. Likewise, residency training location, the ability to use their skills and knowledge fully, and the quality of recruitment efforts were important considerations in choosing a work location for all physicians. For some, remuneration was very influential in their work location decision; however, many physicians who chose to remain in their smaller 'home' provinces noted the lower cost of living in these provinces. Physicians who graduated in the 1980s and 1990s placed greater emphasis on work-life balance and spouse's employment opportunities than their older generation counterparts. In contrast, physicians who graduated in the 1960s and 1070s highlighted the medical need of the community, and the desire for adventure and to see new places as important. CONCLUSIONS: While many factors for choosing a work location appear to be stable over generations, a number of generational differences were found. Younger physicians placed greater emphasis on work-life balance and spouse's employment than older generation physicians. These differences may have important implications for small population regions which may not be able to support physician-spouse pairs or certain subspecialties. Although economic factors have largely been the focus of recruitment and retention initiatives in these provinces, the findings highlight the importance of addressing the needs and expectations of younger generation physicians in order to attract these physicians.

Reduction in antimicrobial resistance prevalence in Escherichia coli from a pig farm following withdrawal of group antimicrobial treatment.

An important element in the control of antimicrobial resistance (AMR) is reduction in antimicrobial usage. In the veterinary sector individual antimicrobial treatment of livestock, rather than the use of group treatment, can help achieve this goal. The aim of this study was to investigate how cessation of group antimicrobial treatment impacted the prevalence of AMR in commensal Escherichia coli in pigs at one farm over an 11-month period. Minimum inhibitory concentrations of eight antimicrobials were determined for 259 E. coli isolates collected during the study. A significant reduction in the prevalence of multidrug resistance and a significant increase in the proportion of full susceptibility to the panel of nine antimicrobials tested was seen after 11 months. Whole genome sequencing of 48 multidrug resistant isolates revealed E. coli clones that persisted across multiple visits and provided evidence for the presence of plasmids harbouring AMR genes shared across multiple E. coli lineages. E. coli were also isolated from on-farm environmental samples. Whole genome sequencing of one multidrug resistant isolate obtained from cleaning tools showed it was clonal to pig-derived E. coli that persisted on the farm for 11 months. In this study we provide evidence that withdrawal of group antimicrobial use leads to significant reductions in key indicators for AMR prevalence and the importance of the farm environment as a reservoir of resistant bacteria. These findings support policy makers and producers in the implementation of measures to control AMR and reduce antimicrobial use.

Validation of an antimicrobial susceptibility testing protocol for Brachyspira hyodysenteriae and Brachyspira pilosicoli in an international ring trial.

Brachyspira hyodysenteriae and Brachyspira pilosicoli cause economically important enteric disease in pigs. Treatment of these infections often includes antimicrobial administration, which can be most effective when therapeutic options are informed by antimicrobial susceptibility testing data. Here we describe a method for broth dilution antimicrobial susceptibility testing of these bacteria, both of which are difficult to culture in vitro. The protocol was evaluated for its fitness for use in an inter-laboratory ring trial involving eight laboratories from seven countries, and employing eleven test strains (5 Brachyspira hyodysenteriae including the type strain B78T and 6 Brachyspira pilosicoli) and six antibiotics. Overall intra- and inter-laboratory reproducibility of this method was very good (>90 % MICs at mode +/- 1 log2). Whole genome sequencing revealed good correspondence between reduced susceptibility and the presence of previously defined antimicrobial resistance determinants. Interestingly, lnu(C) was identified in B. pilosicoli isolates with elevated MICs of lincomycin, whilst tva(B) was associated with elevated MICs of pleuromutilins in this species. We designated two new control strains with MICs lying within currently tested ranges, including for the pleuromutilins, in contrast to the control strain B. hyodysenteriae B78T. These were deposited at the DSMZ-German Collection of Microorganisms and Cell Cultures GmbH. The validation of a standard protocol and identification of new control strains facilitates comparisons between studies, establishment of robust interpretative criteria, and ultimately contributes to rational antimicrobial use when treating infected livestock.

Federal provider conscience regulation: unconscionable.

This paper argues that the provider conscience regulation recently put into place in the USA is misguided. The rule is too broad in the scope of protection it affords, and its conception of what constitutes assistance in the performance of an objectionable procedure reveals that it is unworkable in practice. Furthermore, the regulation wrongly treats refusal of other reproductive services as on a par with conscientious objection to participation in abortion. Finally, the rule allows providers to refuse even to discuss "objectionable" options with patients and serves to protect discriminatory refusals of medical care. For all of these reasons, this regulation is unwise.

Differentiation of UK endemic strains of Salmonella enterica serovar Newport from epidemic North American strains by PCR detection of a truncated bapA chromosomal gene.

The aim of this study was to develop a PCR test to detect chromosomal differences between epidemic multidrug resistant (epi-MDR) strains of Salmonella enterica serovar Newport (S. Newport) and non-epi-MDR strains of S. Newport that are endemic to the United Kingdom (UK). Sequence analysis of the biofilm-associated protein A gene (bapA) showed that epi-MDR strains of S. Newport from the United States of America (USA) had a deletion of 309 bp, which was not present in non-epi-MDR strains of S. Newport from the UK. A PCR test was developed using primers designed to target this difference and was applied to a panel of S. Newport isolates comprising of strains from the UK (n=20, non-epi-MDR), from the USA (n=10, epi-MDR) and from Canada (n=7). A second panel of isolates (n=73) was used to assess the test specificity, and these isolates consisted of non-Newport Salmonella serovars (n=25), and other epidemic serovars (n=48). Epi-MDR S. Newport isolates produced a characteristic 505 bp amplicon, whereas non-epi-MDR S. Newport isolates produced an 814 bp amplicon. The bapA PCR has potential to discriminate between these S. Newport strains irrespective of their carrying resistance genes.

Successful pregnancy after high dose chemotherapy and marrow transplantation for treatment of aplastic anemia.

A 29-year-old woman with severe idiopathic aplastic anemia was given immunosuppressive therapy with procarbazine, 37.5 mg/kg, antithymocyte globulin, 36 mg IgG/kg, and cyclophosphamide, 200 mg/kg. This was followed by a marrow transplant from her HLA identical sister, immunosuppressive therapy with intermittent methotrexate for 3 months postgrafting and ultimate restoration of hematopoiesis. Two years after transplantation the patient delivered a healthy male infant. This is the first successful pregnancy after a high dose chemotherapy and marrow transplantation for treatment of aplastic anemia.

Chronic myelomonocytic leukemia: an ultrastructural study by transmission and scanning electron microscopy.

The hematologic findings in three cases of chronic myelomonocytic leukemia are presented, with results of ultrastructural studies by transmission and scanning electron microscopy on two of the cases. In the peripheral blood there was a dual, non-lymphocytic, markedly increased population of granulocytes and monocytes. The granulocytes showed marked nuclear abnormality and nuclear cytoplasmic organelle asynchrony. In the marrow the majority of the cells appeared granulocytic but atypical forms and intermediate difficult to distinguish from monocyte precursors were evident by electron microscopy. The ultrastructural findings lend some support to the concept that the neoplastic granulocytes and monocytes having a common precursor.

Red cell membrane changes during storage.

A great deal is known about the red cell membrane and its abnormalities in various pathologic states. During red cell storage there is a progressive development of spheroechniocytosis with eventual production of irreversibly nondeformable red cells. The loss of membrane function is most likely related to some abnormality in maintenance of the cytoskeleton of the red cell. These changes appear to occur independent of ATP levels. Despite the increasing knowledge of the structure and function of the red cell membrane very little as yet is known about the specific abnormality in the red cell membrane that occurs during storage in the blood bank. Recent evidence for abnormal spectrin-actin interaction and abnormal spectrin oxidation has been the most promising. Areas of interest for research include studies of the specific mechanisms by which the plasticizer DEHP interacts with the membrane, specific definition of the molecular defect in membrane proteins that occurs during storage, and means to prevent these. If such deterioration and membrane stiffening could be prevented then the quality of the red cells that are transfused would be improved both in their function and ability to survive in the microcirculation. A final need, while not of specific value to the red cell itself, is the development of media and additives that will allow for increased plasma and Factor VIII yields, one of the driving forces in the blood transfusion system.

Effect of splenectomy on slowing human immunodeficiency virus disease progression.

BACKGROUND: Lymphoreticular tissue is the most important site for human immunodeficiency virus (HIV) replication in HIV-infected individuals. OBJECTIVE: To compare the long-term effect of splenectomy on survival and time to development of acquired immunodeficiency syndrome in subjects who had undergone splenectomy with subjects who had not undergone splenectomy. DESIGN: A cohort study with a follow-up of up to 13.4 years. SETTING: Subjects were recruited from a hospital outpatient clinic population and a multicenter study of patients with hemophilia. PARTICIPANTS: Forty-five HIV-infected individuals were observed prospectively for up to 13.4 years (17 had undergone splenectomy and 28 had not undergone splenectomy). Five subjects underwent splenectomy before acquiring HIV infection and 12 underwent splenectomy during the asymptomatic phase of HIV infection. The group who did not undergo splenectomy consisted of HIV-infected individuals who were asymptomatic at study enrollment. MAIN OUTCOME MEASURES: A Cox proportional hazards model was used to test the effects of splenectomy on survival and time to development of acquired immunodeficiency syndrome when adjusting for potential confounders (age, initial CD4+ cell count, and treatment with antiretroviral drugs). Splenectomy was treated as a time-dependent covariate to account for the variation in its timing. RESULTS: During the average follow-up of 8.6 years, 9 (53%) of the 17 subjects who underwent splenectomy and 23 (82%) of the 28 subjects who did not undergo splenectomy died; acquired immunodeficiency syndrome developed in 6 (35%) of the subjects who underwent splenectomy and 23 (82%) of the subjects who did not undergo splenectomy. Splenectomy was associated with a significant reduction of risk of developing acquired immunodeficiency syndrome (adjusted relative risk [RR] <0.4, P<.05), whereas the effect on risk of mortality approached, although it did not reach, significance (adjusted RR approximately 0.5, P approximately .10). CONCLUSION: The absence of a spleen during the asymptomatic phase of HIV infection seems to have a beneficial effect on HIV disease progression.

Growth of malignant histiocytic cells induced by phorbol myristate acetate.

Cells from the spleen of a patient with malignant histiocytosis were cultured in methyl cellulose with and without 100 ng/mL of phorbol myristate acetate (PMA). Colony growth occurred only with PMA; comparing surface marker studies of the cells before and after culture, it was evident that proliferation had occurred among the histiocytic cells as well as the lymphocytes. After exposure to PMA in organ culture for ten days, the histiocytes appeared to be differentiated and showed evidence of continuing phagocytosis by electron microscopy. This suggests that PMA is a mitogen for the histiocytes in this condition and maintains differentiation of the cells.

Effects of blood and crystalloid cardioplegia on cardiac function at organ and cellular levels during hypothermic cardiac arrest.

The present investigation was undertaken to compare the effects of cold crystalloid and blood cardioplegia on the functional recovery of the heart; on Ca++ binding and uptake, Ca++-ATPase of the sarcoplasmic reticulum (SR), and sarcolemmal (SL) ATPase; and on serum MB fraction of creatine kinase (MBCK) after one and half hours of reperfusion following one hour of ischemic cardiac arrest in dog. This study was made also to determine if the functional changes are related to the changes in biochemistry at the molecular level. The dogs were divided into three groups: sham bypass (SB), cold crystalloid cardioplegia (CC), and pump blood cardioplegia (PB). There was a decrease in the cardiac index (CI), left ventricular work index (LVWI), and mean aortic pressure (MAP) in all three groups. The index of myocardial contractility [dp/dt)/IIP) and CI were lower in the CC group as compared with the SB and PB groups. All the hemodynamic values for the PB group were similar to those of the SB group except total systemic vascular resistance (TSVR) and left ventricular end-diastolic pressure (LVEDP) which were lower in the PB group. The index of myocardial contractility and cardiac index appeared to be greater in the PB group than in the CC group. There was a decrease in the Ca++ uptake by SR from both the CC and PB groups. Ca++ binding and Ca++,-ATPase of SR from the PB group were depressed. The sarcolemmal ATPase was unaffected in both groups. The serum MBCK increased in both PB and CC groups, though the increase was smaller in the PB group. These results indicate that the functional recovery of the heart was slightly better with pump blood cardioplegia than with cold crystalloid cardioplegia. The depressed myocardial contractility and cardiac function in the CC group were associated with a decrease in the Ca++ uptake by SR. However, the decreases in the Ca++ binding, Ca++ uptake, and Ca++ ATPase by SR from the pump blood cardioplegic group were not accompanied by decreases in the cardiac contractility and cardiac function. Myocardial damage as assessed by serum MBCK was smaller in the PB group than in the CC group.

High 2,3-DPG blood cardioplegia and myocardial preservation during cardiopulmonary bypass.

Blood may provide superior cardioplegia compared with crystalloid cardioplegic solution. However, the results are controversial. This may be due to a leftward shift of the hemoglobin (Hb)-O2 dissociation curve induced by hypothermia, increasing the oxygen affinity for Hb. This effect may negate the potential benefit of blood cardioplegia. The oxygen affinity for Hb can be decreased by increasing the red cell 2,3-diphosphoglycerate (2,3-DPG), and hence, more oxygen can be delivered to the myocardium. The present investigation was undertaken to study the effects of 2,3-DPG-enriched blood cardioplegia on the functional recovery of the myocardium and changes in the coronary sinus red blood cell (RBC) adenosine-triphosphate (ATP), lactate, and RBC DPG after one and a half hours of reperfusion following one hour of ischemic cardiac arrest in dogs. The dogs were divided into three groups: crystalloid (CR); stored blood (SB), and high 2,3-DPG blood (HDPG) cardioplegic groups. Incubation of canine RBC in phosphoenal pyruvate (PEP) led to a 36% increase in DPG and a rightward shift in the Hb-O2 dissociation curve. There was a 4 mm Hg shift in the P50. When compared with the CR group, there was a significant decrease in the cardiac index (CI) and left ventricular work index (LVWI) and a significant increase in the total systemic vascular resistance (TSVR) in the SB group. The CI and LVWI of the HDPG group were similar to those of the CR group, but the TSVR was significantly greater in the former group. The LVWI was significantly greater and the TSVR smaller in the HDPG group as compared with those in the SB group.(ABSTRACT TRUNCATED AT 250 WORDS)