Radio emission from the unbound debris of tidal disruption events

When a star gets too close to a supermassive black hole, it is torn apart by the tidal forces. Roughly half of the stellar mass becomes unbound and flies away at tremendous velocities - around 104 km s-1. In this work, we explore the idea that the shock produced by the interaction of the unbound debris with the ambient medium gives rise to the synchrotron radio emission observed in several tidal disruption event (TDE). We use a moving mesh numerical simulation to study the evolution of the unbound debris and the bow shock around it. We find that as the periapse distance of the star decreases, the outflow becomes faster and wider. A TDE whose periapse distance is a factor of 7 smaller than the tidal radius can account for the radio emission observed in ASASSN-14li. This model also allows us to obtain a more accurate estimate for the gas density around the centre of the host galaxy of ASASSN-14li.

The effect of substrate composition and storage time on urine specific gravity in dogs

OBJECTIVES

The purpose of this study is to evaluate the effects of substrate composition and storage time on urine specific gravity in dogs.

METHODS

A descriptive cohort study of 15 dogs. The urine specific gravity of free catch urine samples was analysed during a 5-hour time period using three separate storage methods; a closed syringe, a diaper pad and non-absorbable cat litter.

RESULTS

The urine specific gravity increased over time in all three substrates. The syringe sample had the least change from baseline and the diaper sample had the greatest change from baseline. The urine specific gravity for the litter and diaper samples had a statistically significant increase from the 1-hour to the 5-hour time point.

CLINICAL SIGNIFICANCE

The urine specific gravity from canine urine stored either on a diaper or in a non-absorbable litter increased over time. Although the change was found to be statistically significant over the 5-hour study period it is unlikely to be clinically significant.

Grading evidence and recommendations for clinical practice guidelines in nephrology. A position statement from Kidney Disease: Improving Global Outcomes (KDIGO)

Considerable variation in grading systems used to rate the strength of guideline recommendations and the quality of the supporting evidence in Nephrology highlights the need for a uniform, internationally accepted, rigorous system. In 2004, Kidney Disease: Improving Global Outcomes (KDIGO) commissioned a methods expert group to recommend an approach for grading in future nephrology guidelines. This position statement by KDIGO recommends adopting the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach for the grading of evidence and guidelines on interventions. The GRADE approach appraises systematic reviews of the benefits and harms of an intervention to determine its net health benefit. The system considers the design, quality, and quantity of studies as well as the consistency and directness of findings when grading the quality of evidence. The strength of the recommendation builds on the quality of the evidence and additional considerations including costs. Adaptations of the GRADE approach are presented to address some issues pertinent to the field of nephrology, including (1) the need to extrapolate from studies performed predominantly in patients without kidney disease, and (2) the need to use qualitative summaries of effects when it is not feasible to quantitatively summarize them. Further refinement of the system will be required for grading of evidence on questions other than those related to intervention effects, such as diagnostic accuracy and prognosis.

Dynamic pressures on the diabetic foot

A retrospective study was conducted in order to investigate the relation between increased plantar pressure and ulcers in the diabetic foot and contribute more information on this subject. Maximal plantar pressure (MPP) is reported on various areas of the plantar aspects of the feet in 328 diabetic patients and 75 healthy subjects. An increase in MPP under all plantar areas except for the heels was found to be related with increasing severity of the diabetes symptoms. There was also a significant decrease in the application of high pressures to the heels, the metatarsal heads II-IV and the toes.

Characteristic dynamic differences between healthy and low back pain subjects

STUDY DESIGN

Open retrospective study.

OBJECTIVES

To assess the functional capacity impairment of chronic low back pain (LBP) patients using characteristic dynamic changes.

SETTING

Orthopaedics and Physiotherapy departments at Tel-Aviv, Israel.

METHODS

Thirty-eight normal healthy volunteers and 607 chronic LBP patients were tested on a computerized 3-D lumbar dynamometer. The four major parameters measured were the maximal isometric torque (MIT), maximal velocity against 25% MIT and 50% MIT (MV25, MV50, respectively) and maximal torques in secondary axes (MST). All patients parameters were compared to the normal, healthy findings.

RESULTS

All four parameters were found to be significantly different between healthy (or non-symptomatic) and symptomatic LBP subjects.

CONCLUSIONS

The findings support the use of 3-D dynamometry and the four parameters mentioned to objectively classify patients with functional disability.

The National Kidney Foundation Dialysis Outcomes Quality Initiative

Rigorously developed clinical practice guidelines have the potential to change practice patterns to obtain improved patient outcomes. Toward that end, in March 1995 the National Kidney Foundation initiated the Dialysis Outcomes Quality Initiative, a comprehensive effort to create literature-based clinical practice guidelines in nephrology. Independent interdisciplinary work groups reviewed the available body of scientific literature on the following topics: hemodialysis adequacy, peritoneal dialysis adequacy, vascular access, and anemia. More than 11,000 papers were identified; of these approximately 1500 were found to be relevant, requiring formal structured review. Work groups formulated draft guidelines with supporting rationales that included the evidentiary basis for the recommendations. The draft guidelines were subjected to an unprecedented three-stage review process that involved more than 50 organizations from the renal community, including end-stage renal disease networks, patients dialysis providers, managed care organizations, and government. The finalized guidelines were issued in September 1997. Planned guideline implementation activities will focus on achieving the following: cooperation from the renal community; education of patients, clinicians, policy makers, and dialysis providers; information system tools to facilitate adoption of the guidelines; and evaluation strategies to determine whether practice patterns and outcome goals are achieved.

National Kidney Foundation: Dialysis Outcome Quality Initiative--development of methodology for clinical practice guidelines

BACKGROUND

The NKF-DOQI (National Kidney Foundation--Dialysis Outcomes Quality Initiative) began in March 1995 with the following objectives: To improve end-stage renal disease (ESRF) patient survival, to reduce patient morbidity, to increase efficiency of care, and to improve quality of life for ESRF patients.

METHODS

The development of the NKF-DOQI Clinical Practice Guidelines focused on haemodialysis adequacy, peritoneal dialysis adequacy, vascular access, and anaemia. Principles guiding the methodology included scientific and methodological rigour, interdisciplinary approach, independence of the Work Groups, and an open review process. Unique features of this evidence-based guideline development process included the use of mock guidelines and rationales to guide the literature research, and an unprecedented three-stage review process.

RESULTS

Work Groups reviewed more than 11,000 articles. A total of 114 clinical practice guidelines were developed by the Work Groups; these have been reviewed by more than 1200 professionals and patients.

CONCLUSION

The NKF-DOQI Clinical Practice Guidelines has been a unifying effort for the entire renal community. The guidelines are an important step in the process of improving the quality of dialysis practice and improving ESRF patient outcomes. Priorities for implementation of the guidelines include education of ESRF professionals and patients, working with providers and insurers to encourage compliance, and follow-up evaluation of patient outcomes to quantify compliance results.

Spontaneous echocardiographic contrast within an unruptured sinus of Valsalva aneurysm: a potential embolic source diagnosed by transesophageal echocardiography

A 75-year-old male patient had an unexplained transient ischemic attack. Transesophageal echocardiography revealed a large, unruptured Sinus of Valsalva aneurysm which contained spontaneous echo contrast. This finding represents a potential source of embolism.

Anaplastic B-cell (Ki-1) lymphoma developing in a patient with polycythemia vera

The association of lymphoproliferative disorders and polycythemia vera (PV) is extremely rare. Here we report a patient with PV who developed anaplastic B-cell (Ki-1) non-Hodgkin's lymphoma (NHL). The rare occurrence of lymphoproliferative disorder in the course of PV, may indicate that in a minority of patients, clonal expansion of an abnormal pluripotent haemopoetic stem cell could be responsible for both the PV and the NHL.

The pivotal role of the academic health center

Academic health centers (AHCs) now play major roles in the development, adoption, and evaluation of medical technologies; the provision of advice to other entities involved in medical innovation; and the education of current and future practitioners. However, recent and potential health care reform initiatives could make it increasingly difficult for AHCs to continue to play their historical roles in medical innovation. Policymakers are examining specific options that would explicitly cover the cost of some of these services but could take away some of the autonomy AHCs have enjoyed and could change the role of AHCs in technological innovation.

Fatal listeria meningitis in an immunocompromised infant: therapeutic implications

Infection with Listeria monocytogenes is rare in infants and children. Listeriosis has been made a notifiable condition in the State of California since 1985. From January 1985 to December 1990, only seven cases of listeriosis have been reported in children less than or equal to 13 years of age. This brief report summarises the features of a fatal case of listeria meningitis in an immunocompromised 4-month-old infant, discusses diagnostic and therapeutic implications, and describes the other six cases.

Amplification techniques for detection of herpes simplex virus in neonatal and maternal genital specimens obtained at delivery

Viral culture amplification methods, including centrifugation, use of a cell pretreatment medium containing dimethyl sulfoxide and dexamethasone (DEX medium), and three commercial enzyme immunoassays (EIAs), were evaluated for use with low-titer, asymptomatic neonatal and obstetric samples obtained at delivery. The 4.5-h Ortho EIA was 59.7% sensitive at 16 h compared with 86.4% at 36 h in a spin-amplified format (SAT-EIA). After 36 h with DEX medium, the SAT-EIA was 97.3% sensitive using the 2.5-h modified Ortho EIA and 69.9% sensitive using the Fairleigh Dickinson EIA. Herpes simplex virus (HSV) cytopathic effect was reported in tube culture 1 to 2 days earlier in 8.1 to 35.9% of cells with DEX medium. Overall, the SAT-EIA using the modified Ortho EIA and cells with DEX medium detected 147 of 153 (96.1%) HSV isolates from samples obtained predelivery and 93.1% of 29 HSV positives from samples obtained at labor and delivery, with specificities of 100 and 99.9%, respectively, at 36 h.

The role of percutaneous nephrostomy in the management of obstructing candidiasis of the urinary tract in infants

We report on 5 neonates with obstructive urinary tract candidiasis in whom percutaneous nephrostomy had a major role in management. The advantages of percutaneous nephrostomy in this setting include prompt drainage of the obstructed renal pelvis or ureter, direct access to obtain specimens from the renal pelvis to confirm the diagnosis, direct irrigation of the fungus balls with amphotericin B and an access route for fragmentation of fungus balls by guide wire manipulation. In 3 cases percutaneous placement of the nephrostomy tube was successful in obtaining and maintaining access to the renal pelvis, while in 2 surgical intervention was required because of problems maintaining placement of the percutaneous catheters. Percutaneous nephrostomy with antegrade amphotericin B irrigation, coupled with systemic antifungal therapy, is the mainstay of treatment. The usefulness of ultrasonography in the early diagnosis of renal candidiasis also is emphasized.

Herpes simplex virus testing of an obstetric population with an antigen enzyme-linked immunosorbent assay

Commercial herpes simplex virus antigen enzyme-linked immunosorbent assay kits were compared to conventional culture for herpes simplex virus with 3237 genital specimens from obstetric patients. These rapid enzyme-linked immunosorbent assay tests had a sensitivity of 34.3% and specificity of 98.1% with primarily cervical specimens from asymptomatic patients. Specimens from vulvar swabs had higher positive rates than those from cervical swabs from the same patient, whether symptomatic or asymptomatic with both culture and enzyme-linked immunosorbent assay. Fifty-six women had enzyme-linked immunosorbent assay false positive tests; use of enzyme-linked immunosorbent assay testing alone could have resulted in 1.7% unnecessary cesarean deliveries. Six cases of neonatal herpes simplex virus infection were identified; two of the mothers had negative cervical cultures the week of delivery preceded by positive vulvar cultures.

Diagnosis related group prospective payment: implications for health care and medical technology

This paper reviews the major features of the new DRG prospective payment system which was introduced for the payment of hospitals under the Medicare program October 1, 1983 in the United States. It explores its general implications for the health sector, and then examines its specific implications for the development, diffusion, and utilization of medical technology. It concludes with some of the research questions that require investigation to provide an informed basis for modification to the payment system that will ensure that quality health care will be provided at an affordable cost.

Bactericidal studies of penicillin-gentamicin combinations against group B streptococci

The bactericidal activity of penicillin-aminoglycoside combinations was studied in 16 strains of Group B streptococci. Minimal inhibitory concentrations (MIC) against kanamycin or gentamicin were greater than 50 microgram/ml, whereas ampicillin or penicillin inhibitory concentrations were uniformly less than 0.1 microgram/ml. Although all strains had bactericidal concentrations (MBC) less than 0.1 microgram penicillin/ml, penicillin at a concentration equal to each strains respective MBC reduced inoculum colony forming units (CFU) 2 logs in only 6 of 16 strains in bactericidal kinetic studies. However, the addition of gentamicin in concentrations of 5.0 or 10.0 microgram/ml to penicillin markedly enhanced bactericidal activity in all strains tested. The addition of lower concentrations of gentamicin (1.0 microgram/ml) had minimal advantage over penicillin alone. No distinct advantage was noted for combinations including either ampicillin or kanamycin. The theoretical advantage of penicillin-aminoglycoside combinations in experimental conditions, suggests that the use of antibiotic combinations in clinical infections due to Group B streptococci, may result in a more rapid eradication of these organisms.