Black-box superconducting circuit quantization

We present a semiclassical method for determining the effective low-energy quantum Hamiltonian of weakly anharmonic superconducting circuits containing mesoscopic Josephson junctions coupled to electromagnetic environments made of an arbitrary combination of distributed and lumped elements. A convenient basis, capturing the multimode physics, is given by the quantized eigenmodes of the linearized circuit and is fully determined by a classical linear response function. The method is used to calculate numerically the low-energy spectrum of a 3D transmon system, and quantitative agreement with measurements is found.

B cell repopulation after alemtuzumab induction-transient increase in transitional B cells and long-term dominance of naïve B cells

In organ transplantation, the composition of the B-cell compartment is increasingly identified as an important determinant for graft outcome. Whereas naïve and transitional B cells have been associated with long-term allograft survival and operational tolerance, memory B cells have been linked to decreased allograft survival. Alemtuzumab induction therapy effectively depletes B cells, but is followed by rapid repopulation up to levels exceeding base line. The characteristics of the repopulating B cells are currently unknown. We studied the phenotypic and functional characteristics of B cells longitudinally in 19 kidney transplant recipients, before and at 6, 9 and 12 months after alemtuzumab induction therapy. A transient increase in transitional B cells and cells with phenotypic characteristics of regulatory B cells, as well as a long-term dominance in naïve B cells was found in alemtuzumab-treated kidney transplant recipients, which was not influenced by conversion from tacrolimus to sirolimus. At all time-points after treatment, B cells showed unaltered proliferative and IgM-producing capacity as compared to pretransplant samples, whereas the ability to produce IgG was inhibited long-term. In conclusion, induction therapy with alemtuzumab results in a long-term shift toward naïve B cells with altered phenotypic and functional characteristics.

Physically-Based Interactive Flow Visualization Based on Schlieren and Interferometry Experimental Techniques

Understanding fluid flow is a difficult problem and of increasing importance as computational fluid dynamics (CFD) produces an abundance of simulation data. Experimental flow analysis has employed techniques such as shadowgraph, interferometry, and schlieren imaging for centuries, which allow empirical observation of inhomogeneous flows. Shadowgraphs provide an intuitive way of looking at small changes in flow dynamics through caustic effects while schlieren cutoffs introduce an intensity gradation for observing large scale directional changes in the flow. Interferometry tracks changes in phase-shift resulting in bands appearing. The combination of these shading effects provides an informative global analysis of overall fluid flow. Computational solutions for these methods have proven too complex until recently due to the fundamental physical interaction of light refracting through the flow field. In this paper, we introduce a novel method to simulate the refraction of light to generate synthetic shadowgraph, schlieren and interferometry images of time-varying scalar fields derived from computational fluid dynamics data. Our method computes physically accurate schlieren and shadowgraph images at interactive rates by utilizing a combination of GPGPU programming, acceleration methods, and data-dependent probabilistic schlieren cutoffs. Applications of our method to multifield data and custom application-dependent color filter creation are explored. Results comparing this method to previous schlieren approximations are finally presented.

Short-term metabolic effects of prednisone administration in healthy subjects

AIMS

Supraphysiologic glucocorticoid activity is well established to cause impaired glucose tolerance and insulin resistance, yet no study has evaluated dose-dependent effects of low-dose prednisone during short-term oral administration.

METHODS

The objective of this study was to quantify the effects of daily 10 or 25 mg prednisone administration for one week on insulin sensitivity by employing a two-step hyperinsulinemic euglycemic glucose clamp (Step 1: insulin infusion = 20 mU/m²/min; Step 2: insulin infusion = 80 mU/m²/min) in healthy, lean males. The amount of glucose infused at steady-state to maintain stable blood glucose [90 mg/dl (4.95 mmol/l)] was used to calculate several indices of insulin sensitivity.

RESULTS

During Step 1 of the clamp, whole body glucose disposal (M) was reduced by 35% (p = 0.003) and M/I was reduced by 29% (p = 0.025) for 25 mg prednisone compared to placebo. No appreciable effect of 10 mg prednisone was observed. During Step 2, M was reduced by 33% (p = 0.001) and 15% (p = 0.006) for 25 and 10 mg prednisone compared to placebo; and M/I ratio was reduced by 31% (p < 0.001) and 13% (p = 0.026), respectively. The insulin sensitivity index, Si, calculated as the quotient of augmentation of M/I between Step 1 and 2, was reduced by 35.3% (p < 0.01) and 23.5% (p < 0.05) for 25 and 10 mg prednisone, respectively.

CONCLUSION

Administration of relatively low pharmacological doses of prednisone for one week impaired insulin sensitivity in a dose-dependent manner in healthy males. These observed changes in insulin sensitivity are likely to be clinically relevant, especially in individuals predisposed to develop glucose intolerance.

Partner Counselling and Referral Services (PCRS) for HIV in Armed Forces - Visiting a Blind Spot

The Indian armed forces have over 5000 cases of human immunodeficiency virus (HIV) infection since 1990. The spouses of the affected soldiers are at a constant risk of contracting infection if not informed of their husband's HIV status. The onus of counselling the spouse has been delegated to the commanding officer (CO) of the soldier as per policy. The spouses usually reside at their hometown away from the soldier's unit and bridging this "geographical discordance" and offering effective counselling becomes a tricky issue for the commanding officer (CO). This article examines the effectiveness of this strategy as practised in Indian armed forces.

Correlation between Systemic Lupus Erythematosus Disease Activity Index, C3, C4 and Anti-dsDNA Antibodies

BACKGROUND

Therapeutic decisions in systemic lupus erythematosus (SLE) are based on the disease activity and nature of organ involvement. There are various clinical and laboratory methods to assess the lupus flares.

METHODS

Fifty one SLE patients with active disease (lupus flare) were studied. Systemic lupus erythematosus disease activity index (SLEDAI), C3, C4 and anti-double stranded DNA levels were estimated and repeated monthly till remission. After remission these tests were done three monthly. Values of serological parameters were then correlated with SLEDAI score.

RESULT

Thirteen (25.4%) patients had predominantly renal involvement while 38 (74.6%) patients had non-renal affliction. Musculoskeletal and mucocutaneous symptoms were the commonest features of lupus flare (90%). It was observed that 12 out of 13 (92.3%) patients with active renal involvement had low C3 levels and 11 (84.6%) had low C4 levels. The anti-dsDNA levels were elevated in all patients with predominant renal flare. In non-renal flare anti-dsDNA titre was raised only in 35% cases. Low C3 and C4 levels were noticed in 43% and 53% of non-renal flares respectively. Significant positive correlation was noticed between SLEDAI score and anti-dsDNA levels (0.01 level two-tailed prediction) and a significant negative correlation was observed with SLEDAI and C3, C4 levels (0.01 and 0.05 levels, two-tailed prediction) in our patients. On subgroup analysis it was noticed that this correlation is stronger for renal lupus. Negative correlation of SLEDAI and complement levels was not observed in non-renal flares.

CONCLUSION

Calculation of SLEDAI is a vital clinical tool for assessment of SLE patients. Serial estimation of anti-dsDNA titre, C3 and C4 levels help us diagnose lupus flare and make appropriate therapeutic decisions in patients with high SLEDAI score.

Clinical significance of antiphospholipid antibodies in Indian scleroderma patients

In patients with systemic sclerosis (SSc), antiphospholipid antibodies (aPL) have been reported to be associated with more severe manifestations including digital infarct, gangrene and pulmonary hypertension. But these findings are not consistent in all studies; moreover, there are no data available from Indian subcontinent. The objective of this study is to assess the prevalence of antiphospholipid antibodies in Indian SSc patients and correlate them with clinical and immunological features. Seventy-two patients were recruited prospectively from rheumatology clinic from 2002 to 2006. Their medical records were reviewed. Anticardiolipin antibodies (IgG, IgM) by ELISA and lupus anticoagulant (LA) were tested in standardized pattern and repeated after 6 weeks. Anti-β2 glycoprotein-I antibodies were done in patients who had aPL antibodies. Nineteen patients had diffuse cutaneous SSc and 53 had limited disease. Seven patients (9.7%) were positive for aPL antibodies in their sera. Only one patient had clinical features of antiphospholipid antibody syndrome and manifested with recurrent abortions and deep vein thrombosis. She was positive for aCL, LA and anti-β2 glycoprotein-I antibodies. Four patients were only aCL (IgG) positive in moderate titers and one each had only aCL (IgM) and LAC positivity. None of the clinical parameters showed an association with aPL antibody.

Determining dental sex dimorphism in South Indians using discriminant function analysis

Dental forensics forms a vital branch of forensic science which deals with proper handling, examination and evaluation of dental evidences for identification of victims of crime, accidents or calamities. Therefore skull and teeth often provide the identification material. The aim of the study was to investigate the accuracy of odontometric methods in sex determination of permanent teeth and to compute new formula to differentiate male and female teeth using discriminant function analysis for South Indian population. A total of 100 subjects were selected for the study from a parent population of 4800 students by simple random sampling method. Alginate impressions of the upper dental arch were made and casts were poured immediately. A digital vernier calliper was used for the measurement of all upper anteriors. Twelve different tooth measurements were recorded and from those two indexes have been computed. Statistical analysis was performed using the SPSS version 17.0 software. All the predictor variables were subjected to stepwise discriminant function analysis which optimally separates the genders and a best discriminant function was generated. In all the observed mean dimensions, male values exceed the female values. Student's 't' test for the different predictor variables of all teeth selected between male and females were found significant (p < 0.05). Very high significance was found in mean MD of 11, 12 and 13 and |c| of 23. The variables exhibiting best discriminant powers were mesiodistal width of both upper central incisors, DB-ML of 13 and canine crown module of 13. Sexual dimorphism in the size of permanent teeth differs from one population to the other and hence the standards set for one population could not be applied for another population. Hence this technique would be a simple, quick, cost effective, reliable and accurate for sex determination.

Omental cakes: unusual aetiologies and CT appearances

Background

Omental cakes typically are associated with ovarian carcinoma, as this is the most common malignant aetiology. Nonetheless, numerous other neoplasms, as well as infectious and benign processes, can produce omental cakes.

Methods

A broader knowledge of the various causes of omental cakes is valuable diagnostically and to direct appropriate clinical management.

Results

We present a spectrum of both common and unusual aetiologies that demonstrate the variable computed tomographic appearances of omental cakes.

Conclusion

The anatomy and embryology are discussed, as well as the importance of biopsy when the aetiology of omental cakes is uncertain.

Randomized clinical trial of short-term outcomes following purse-string versus conventional closure of ileostomy wounds (Br J Surg 2010; 97: 1511–1517)

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.

Focal nodular hyperplasia: central scar enhancement pattern using Gadoxetate Disodium

PURPOSE

To illustrate the unusual enhancement pattern of the focal nodular hyperplasia central scar using Gadoxetate Disodium.

MATERIALS AND METHODS

Over a 10-month period, six patients, with a total of seven focal nodular hyperplasia lesions with typical central scar, had MRI of the liver using Gadoxetate Disodium (Eovist, Bayer HealthCare Pharmaceuticals Inc., Wayne, NJ). Four of the six patients had a prior Gadobenate Dimeglumine (Multihance, Bracco Diagnostics Inc., Princeton, NJ) -enhanced MRI of the liver performed within the previous year. The dynamic enhancement pattern of the central scar on the 10 liver MRIs was independently analyzed by two abdominal imaging radiologists who were blinded to the contrast agent used.

RESULTS

On the Gadoxetate Disodium-enhanced MRIs and during the arterial phase, 1-min, 2-min, and 3-min delay, none of the central scars demonstrated enhancement. However, all four of the lesions that were previously scanned using Gadobenate Dimeglumine demonstrated typical enhancement after a 3-min delay.

CONCLUSION

On Gadoxetate Disodium-enhanced MRIs of the liver, the central scar of focal nodular hyperplasia lesions does not typically demonstrate delayed enhancement.

Extramedullary duodenal plasmacytoma presenting with gastric outlet obstruction and painless jaundice

Malignant plasma cells in multiple myeloma are predominantly confined to the medullary space of the skeletal system, therefore the disease course will be dominated by signs and symptoms related to bone marrow infiltration and destructive bone lesions with their consequences as well as abnormal protein production. Visceral extramedullary plasmacytoma involving the gastrointestinal system and particularly the duodenum is a rare manifestation of the disease. We report a case of duodenal extramedullary plasmacytoma presenting with gastric outlet obstruction and painless jaundice, in a patient treated for multiple myeloma. Diagnosis was first suggested on imaging, and proved by endoscopic biopsy. The duodenal mass resolved following chemotherapy.

Giant urethral stone presenting as a scrotal mass: Case report

Primary urethral stones are a rare form of urolithiasis accounting for less than 0.3% of urinary stones. We are reporting a case of a giant primary urethral stone that developed in the penile urethra resulting from a post-surgical complication of urethral stricture. The patient presented with difficulty urinating, ejaculatory dysfunction, and a hard palpable scrotal mass.

Multifocal extra-adrenal myelolipoma arising in the greater omentum

Myelolipomas are rare benign tumors composed of mature fat and hematopoietic elements. They are most often discovered incidentally within the adrenal glands, with extra-adrenal myelolipomas being extremely rare tumors. We report a case of multifocal omental extra-adrenal myelolipoma in a patient who had undergone bilateral adrenalectomy. To our knowledge, this is the first reported case of an intraperitoneal extra-adrenal myelolipoma.

Imaging of gastrointestinal stromal tumors before and after imatinib mesylate therapy

Gastrointestinal stromal tumors (GISTs) account for the majority of gastrointestinal mesenchymal tumors. Recent advances in treatment using the molecular targeting agent imatinib mesylate have shown startling response rates and variegated imaging findings. We present the various imaging appearances of GIST on computed tomography (CT) and magnetic resonance imaging (MRI), both before and after treatment.

Atherosclerosis in Asian Indians with systemic lupus erythematosus

OBJECTIVES

Atherosclerosis has emerged as an important late complication of systemic lupus erythematosus (SLE). Asian Indians, as an ethnic group, are known to be metabolically predisposed to development of early atherosclerosis. No data on this aspect of SLE are available from Asia. This study was undertaken to find the frequency of atherosclerosis in Indian lupus patients and the factors affecting such an occurrence.

METHODS

Carotid artery intimo-medial thickness (IMT) and plaque were used as markers of atherosclerosis. High-resolution B-mode ultrasonography was used to compare carotid IMT and plaque in 50 patients with SLE and 50 age- and sex-matched healthy controls.

RESULTS

Patients with lupus (age 31.6+/-10.05, median 30.5 years; disease duration 52.3+/-36.7, median 46 months) exhibited a significantly greater IMT than controls (0.417+/-0.07 vs. 0.362+/-00.07 mm; p = 0.003). Carotid plaques were seen in seven (14%) cases. None of the control population had plaques (p = 0.006). On bivariate analysis, the IMT was significantly affected by age, systolic blood pressure (SBP), disease duration and menopausal status. On multivariate analysis, the only factor significantly affecting IMT was SBP. The Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) score was the sole factor found to significantly affect the occurrence of plaque.

CONCLUSIONS

Asian Indian lupus patients in our study, despite being relatively young and with shorter disease duration, exhibited premature atherosclerosis in the form of significantly thicker intimo-media and plaque. The factors found to affect accelerated atherosclerosis in our cohort were age, SBP, disease duration, postmenopausal status and the SLICC/ACR score.

Clonal evolution of resistance to imatinib in patients with metastatic gastrointestinal stromal tumors

PURPOSE

Resistance to imatinib mesylate is emerging as a clinical challenge in patients with metastatic gastrointestinal stromal tumors (GIST). Novel patterns of progression have been noted in a number of these patients. The objective of this study was to correlate molecular and radiologic patterns of imitinib-refractory disease with existing conventional criteria for disease progression.

EXPERIMENTAL DESIGN

Patients with metastatic GIST treated with imatinib were followed with serial computed tomography/magnetic resonance imaging and [(18)F]fluoro-2-deoxy-d-glucose positron emission tomography. Where feasible, biopsies were done to document disease progression.

RESULTS

A total of 89 patients were followed for a median of 43 months. Forty-eight patients developed progressive disease. A unique "resistant clonal nodule" pattern (defined as a new enhancing nodular focus enclosed within a preexisting tumor mass) was seen in 23 of 48 patients and was thought to represent emergence of clones resistant to imatinib. Nodules were demonstrable a median of 5 months (range, 0-13 months) before objective progression defined by tumor size criteria and were the first sign of progression in 18 of 23 patients. Median survival among patients whose first progression was nodular was 35.1 months, compared with 44.6 months for patients whose first progression met Southwest Oncology Group criteria (P = 0.31). Comparative tumor biopsies were done in 10 patients at baseline and from progressing nodules. Genotypic analyses of KIT and PDGFRA kinases were done, revealing new activating kinase mutations in 80% (8 of 10) of these patients.

CONCLUSION

The resistant clonal nodule is a unique pattern of disease progression seen in patients with GISTs after an initial response to imatinib and reflects the emergence of imatinib-resistant clones. Conventional tumor measurements (Southwest Oncology Group/Response Evaluation Criteria in Solid Tumors) do not detect this subtle finding. A new enhancing nodule growing within a preexisting tumor mass should be classified as a new lesion and be regarded, at least, as partial progression of GIST.

MRI-Guided Percutaneous Cryotherapy for Soft-Tissue and Bone Metastases: Initial Experience

OBJECTIVE

We sought to determine the safety and feasibility of percutaneous MRI-guided cryotherapy in the care of patients with refractory or painful metastatic lesions of soft tissue and bone adjacent to critical structures.

MATERIALS AND METHODS

Twenty-seven biopsy-proven metastatic lesions of soft tissue (n = 17) and bone (n = 10) in 22 patients (15 men, seven women; age range, 24-85 years) were managed with MRI-guided percutaneous cryotherapy. The mean lesion diameter was 5.2 cm. Each lesion was adjacent to or encasing one or more critical structures, including bowel, bladder, and major blood vessels. A 0.5-T open interventional MRI system was used for cryoprobe placement and ice-ball monitoring. Complications were assessed for all treatments. CT or MRI was used to determine local control of 21 tumors. Pain palliation was assessed clinically in 19 cases. The mean follow-up period was 19.5 weeks.

RESULTS

Twenty-two (81%) of 27 tumors were managed without injury to adjacent critical structures. Two patients had transient lower extremity numbness, and two had both urinary retention and transient lower extremity paresthesia. One patient had chronic serous vaginal discharge, and one sustained a femoral neck fracture at the ablation site 6 weeks after treatment. Thirteen (62%) of the 21 tumors for which follow-up information was available either remained the same size as before treatment or regressed. Eight tumors progressed (mean local progression-free interval, 5.6 months; range, 3-18 months). Pain was palliated in 17 of 19 patients; six of the 17 experienced complete relief, and 11 had partial relief.

CONCLUSION

MRI-guided percutaneous cryotherapy for metastatic lesions of soft tissue and bone adjacent to critical structures is safe and can provide local tumor control and pain relief in most patients.

Imaging of brown fat associated with adrenal pheochromocytoma

The association of adrenal pheochromocytoma and brown fat has been described in the pathology literature and scantily in the radiology literature. We present a case of diffuse collection of brown fat in both perinephric spaces associated with left adrenal pheochromocytoma, and describe the computed tomography and magnetic resonance imaging findings.

In planta horizontal transfer of a major pathogenicity effector gene

Xanthomonas citri pv. citri is a clonal group of strains that causes citrus canker disease and appears to have originated in Asia. A phylogenetically distinct clonal group that causes identical disease symptoms on susceptible citrus, X. citri pv. aurantifolii, arose more recently in South America. Genomes of X. citri pv. aurantifolii strains carry two DNA fragments that hybridize to pthA, an X. citri pv. citri gene which encodes a major type III pathogenicity effector protein that is absolutely required to cause citrus canker. Marker interruption mutagenesis and complementation revealed that X. citri pv. aurantifolii strain B69 carried one functional pthA homolog, designated pthB, that was required to cause cankers on citrus. Gene pthB was found among 38 open reading frames on a 37,106-bp plasmid, designated pXcB, which was sequenced and annotated. No additional pathogenicity effectors were found on pXcB, but 11 out of 38 open reading frames appeared to encode a type IV transfer system. pXcB transferred horizontally in planta, without added selection, from B69 to a nonpathogenic X. citri pv. citri (pthA::Tn5) mutant strain, fully restoring canker. In planta transfer efficiencies were very high (>0.1%/recipient) and equivalent to those observed for agar medium with antibiotic selection, indicating that pthB conferred a strong selective advantage to the recipient strain. A single pathogenicity effector that can confer a distinct selective advantage in planta may both facilitate plasmid survival following horizontal gene transfer and account for the origination of phylogenetically distinct groups of strains causing identical disease symptoms.