Manifold spirals, disc-halo interactions and the secular evolution in N-body models of barred galaxies

The manifold theory of barred-spiral structure provides a dynamical mechanism explaining how spiral arms beyond the ends of galactic bars can be supported by chaotic flows extending beyond the bar's co-rotation zone. We discuss its applicability to N-body simulations of secularly evolving barred galaxies. In these simulations, we observe consecutive `incidents' of spiral activity, leading to a time-varying disc morphology. Besides disc self-excitations, we provide evidence of a newly noted excitation mechanism related to the `off-centering' effect: particles ejected in elongated orbits at major incidents cause the disc center-of-mass to recoil and be set in a wobble-type orbit with respect to the halo center of mass. The time-dependent m=1 perturbation on the disc by the above mechanism correlates with the excitation of new incidents of non-axisymmetric activity beyond the bar. At every new excitation, the manifolds act as dynamical avenues attracting particles which are directed far from corotation along chaotic orbits. The fact that the manifolds evolve morphologically in time, due to varying non-axisymmetric perturbations, allows to reconcile manifolds with the presence of multiple patterns and frequencies in the disc. We find a time-oscillating pattern speed profile $\Omega_p(R)$ at distances R between the bar's corotation, at resonance with the succession of minima and maxima of the non-axisymmetric activity beyond the bar. Finally, we discuss disc thermalization, i.e., the evolution of the disc velocity dispersion profile and its connection with disc responsiveness to manifold spirals.Comment: 20 pages, 22 figures. Accepted for publication in MNRA

Charge Symmetry Breaking in 500 MeV Nucleon-Trinucleon Scattering

Elastic nucleon scattering from the 3He and 3H mirror nuclei is examined as a test of charge symmetry violation. The differential cross-sections are calculated at 500 MeV using a microsopic, momentum-space optical potential including the full coupling of two spin 1/2 particles and an exact treatment of the Coulomb force. The charge-symmetry-breaking effects investigated arise from a violation within the nuclear structure, from the p-nucleus Coulomb force, and from the mass-differences of the charge symmetric states. Measurements likely to reveal reliable information are noted.Comment: 5 page

That Which Keeps on Giving - A Case of Class IV Diffuse Proliferative Lupus Nephritis in a Hispanic Woman with underlying Systemic Lupus Erythematosus

Background: Glomerulonephritis is the primary cause of morbidity and mortality of systemic lupus erythematosus (SLE). Lupus nephritis is characterized by immune complex deposition in the mesangium leading to complement activation and hypocomplementemia. Studies show that up to 60% of adults with lupus develop renal involvement and it has been well established that Hispanic patients show poorer outcomes than Caucasians despite advances in treatment. Preserved kidney function with new-onset proteinuria should raise clinical suspicion for acute lupus nephritis. Further evaluation with a kidney biopsy is paramount in establishing a diagnosis, helping to define treatment strategy, and determining response to treatment. Case Presentation: A 41-yo-Hispanic-Woman with a PMH SLE without previous renal involvement, secondary Sjogren\u27s, hypertension, heart failure and cirrhosis presented to the ER with a worsening SOB, difficulty swallowing, and anasarca over two weeks. On evaluation, the patient was hypertensive, tachypneic, had positive JVD, wheezing in lung bases, +1 pitting edema in the lower extremities and skin hyperpigmentation on the face, neck, and upper extremities. Laboratory studies revealed leukocytosis of 11.1 th/uL, Hgb 10 gm/dL, platelets 192 th/uL, Cr 0.9 mg/dL, BUN 17 mg/dL, bicarbonate 19 mmo/L, sedimentation rate 94 mm/hr, and CRP 4.5 mg/L. A urinalysis was performed, which showed 3+ proteinuria with hematuria with a subsequent protein to creatinine ratio demonstrating 2,000 mg/gm. The workup for nephritic range proteinuria revealed an ANA 10U, anti-dsDNA 2.7 IU/mL, negative ANCA, anti-cardiolipin Ab IgMMPL, anti-cardiolipin Ab IgG 14 GPL, and non-reactive HIV, Hepatitis C, and Hepatitis B panels. Despite negative glomerulonephritis workup including anti-dsDNA antibody, a kidney biopsy was pursued and revealed class IV diffuse proliferative lupus nephritis with a component of thrombotic microangiopathy. Conclusion: Kidney biopsies are imperative when establishing a cause of new-onset proteinuria in a patient with a history of SLE. The goal of treatment is induction with immunosuppressive agents to reduce kidney inflammation promptly and prevent flares, decreasing the long-term risk of renal failure. Despite early recognition strategies and advances in treatment, Hispanic patients are likely to be diagnosed with more severe disease at presentation, specifically with class IV or V lupus nephritis. Subsequently, these patients are more likely to develop chronic renal failure compared to Caucasian patients. This case highlights the importance of screening urinalysis for proteinuria for early detection of renal involvement in patients with SLE

A Whole CLOTTA Pain: A Case of IVC Thrombosis Presenting as Severe Abdominal Pain in a Patient with Anti-Phospholipid Syndrome

Background: Anti-phospholipid syndrome (APS) is an immune-mediated condition characterized by the presence of antiphospholipid antibodies in the setting of venous and arterial thrombosis and or pregnancy loss [1]. APS can be a primary syndrome or can be associated with connective tissue diseases such as systemic lupus erythematosus. The goal of treatment in patients with APS is to decrease the risk of thromboembolic events and the standard of care is warfarin therapy. We describe a case of a 42-year-old gentleman with a history of APS on anticoagulation with apixaban who presented to the hospital with severe abdominal pain secondary to infrarenal IVC thrombosis. This case highlights the importance of appropriate anticoagulation in patients with APS. Case Presentation: A 42-year-old man with a past medical history of APS presented to the hospital with a 7-day history of bilateral, dull, non-radiating, generalized abdominal pain. He denied any associated diarrhea, constipation, changes in urination, fever, nausea, or vomiting. Physical examination was notable for tachycardia with HR 110s, BP 150/100 mmHg, and a distended, tender abdomen with visible abdominal varicosities. Labs revealed a WBC 20,000 th/uL, creatinine of 2.0 mg/dL, AST 15 IU/L, ALT 20 IU/L, alkaline phosphatase 101gm/dL, INR of 1.12, and a PTT of 62.2 secs. CT abdomen and pelvis without contrast showed severe narrowing and occlusion of the infrarenal inferior vena cava over a length of 6-7 cm with dilated tortuous varices. Liver US demonstrated normal-appearing flow in hepatic veins and the intrahepatic IVC. The patient was evaluated by surgery however recommendations were made to treat the patient medically with a heparin drip with a bridge to warfarin. Discussion: Anticoagulation therapy in patients with APS is important as these patients can develop severe, life-threatening thrombotic events. Warfarin therapy is superior to direct oral anticoagulant (doac) therapy in preventing thrombotic events in these patients. Given the episode of thrombosis on doac therapy, our patient will be on lifelong warfarin therapy with an INR goal of 3.5. He has not had a recurrence of thrombotic events

Interrupting the Axis: A Case of IgG-4 Related Hypophysitis in a Young Hispanic Male

Background: Hypophysitis refers to inflammation of the pituitary gland that can lead to the disruption of the hypothalamic-pituitary-adrenal axis. Primary hypophysitis has five variants differentiated by histologic findings: lymphocytic, granulomatous, xanthomatous, IgG4-related, and necrotizing. IgG4-related hypophysitis is very rare and is commonly a manifestation of a multi-organ systemic disorder. We present a case of a 43-year-old man presenting with severe headache and symptomatic hyponatremia in the setting of isolated IgG-4 related hypophysitis. Case Presentation: A 43-year-old male presented with a two-day history of severe posterior headache associated with several episodes of vomiting, photophobia, generalized weakness and fatigue. Patient had no history of headaches and denied any recent trauma, focal weakness, altered mentation, changes in vision or seizure activity. Vitals on admission were remarkable for BP 179/99 mmHg. Neurological examination was non-focal, cranial nerves were grossly intact. Labs showed unremarkable CBC, sodium 117 mmol/L, potassium 3.3 mmol/L, chloride 84 mmol/L, glucose 244 mg/d, TSH 0.6 uIU/mL, cortisol 4.6 ug/dL, urine osmolality 540, serum osmolality 259 and prolactin level 7.8. CT head without contrast showed a mass-like enlargement of the Sella measuring 1.6 cm x 1.4 cm suspicious for macroadenoma. Patient was started on hypertonic saline, fludrocortisone, hydrocortisone, and salt tablets in the setting of suspected macroadenoma. Once the patient was stabilized, he underwent transsphenoidal resection of pituitary lesion. Pathology of the lesion showed a small area rich in plasma cells with positive IgG4 immunostaining in most of the plasma cells, consistent with IgG4-related pituitary hypophysitis. Conclusion: IgG4 hypophysitis usually presents in a context of multiple organ IgG4 involvement, however isolated hypophysitis has been reported. The patients present with mass effect symptoms and/or anterior hypopituitarism. When histologic diagnosis is obtained via biopsy, IgG4 hypophysitis can be managed exclusively with corticosteroids

Taponamiento cardiaco secundario a pericarditis tuberculosa aguda en un paciente joven, no asociado a inmunosupresión

ResumenLa pericarditis tuberculosa representa un pequeño porcentaje de la tuberculosis extrapulmonar, cuyo diagnóstico aún constituye un reto por la variabilidad en su presentación. La terapia antimicrobiana dirigida es el pilar del tratamiento, el cual debe seguirse de manera cercana para evaluar las complicaciones asociadas. A continuación presentamos el caso de un hombre de 25 años de edad, previamente sano, quien cursó con el taponamiento cardiaco y la falla cardiaca aguda secundaria a la pericarditis tuberculosa, cuyo diagnóstico y factores de confusión jugaron un papel importante en el desarrollo del caso.AbstractTuberculous pericarditis represents a small percentage of extrapulmonary tuberculosis; its diagnosis still represents a challenge because of the variability of its presentation. Empirical antimicrobial therapy is the mainstay of treatment, which must be followed closely to assess any associated complications. The case of a 25-year old male, previously healthy, who developed cardiac tamponade and acute heart failure secondary to tuberculous pericarditis, whose diagnosis and confusion factors played an important role as the case progressed, is presented

Impact of dedicated women’s outreach workers (WOWs) on recruitment of women in ACTG clinical studies

Background: Despite efforts by the AIDS Clinical Trials Group (ACTG) to enroll representative numbers of diverse women, participation in ACTG studies in the United States remains largely white and male. To address this gap in women’s participation in ACTG research, a one-year pilot study of dedicated women’s outreach workers (WOWs) was proposed. Objectives: included demonstrating that targeted recruitment efforts can expand community awareness of ACTG research and ensuring successful enrollment of women at the respective clinical research sites. Methods: The pilot study was conducted at two U.S. sites (Rutgers New Jersey Medical School and Emory Ponce de Leon Center in Atlanta, Georgia). The WOWs worked with site personnel to identify and reach out to women living with HIV and/or Hepatitis B or C at their respective sites and encourage them to join a clinical trial registry for those interested in participating in future clinical trials. Results: The Rutgers WOW approached 127 potential participants (of whom 100 joined the WOW registry) and screened 35 participants for open ACTG studies. The Emory WOW approached 120 participants, enrolling 86 into the WOW registry, and screened 51 potential participants for open ACTG studies during the WOW’s tenure. The majority of women screened at both sites were women of color. Conclusions: The WOW study team identified several lessons learned that can inform future efforts to engage women living with HIV in clinical research. First, success in engaging women is proportional to level of funding and institutional support. Second, there is a need for a more gender-inclusive scientific agenda as women are more likely to participate if studies address topics of interest to them. Third, meaningful engagement is a two-way street

The role of platelets and neutrophil extracellular traps (NETs) in sepsis: A comprehensive literature review

Sepsis is defined as "an organic dysfunction secondary to the dysregulated response of the patient to an infection." This concept only reveals the tip of the iceberg, the clinical expression of organic failures, without understanding their basis, which is currently explained by cellular and molecular phenomena. Neutrophils are crucial pillars of early innate immune responses, and their fundamental function is phagocytosis. Additionally, neutrophils can degranulate upon activation, releasing various antimicrobial enzymes and pro-inflammatory cytokines, and form neutrophil extracellular traps (NETs), whose purpose is to trap pathogens by releasing their "sticky" nuclear content; the presence of activated platelets amplifies this phenomenon. NETosis is a beneficial process; however, deregulated, it can be detrimental, inducing "immunothrombosis" and compromising the microcirculation, thereby increasing the clinical severity of sepsis. The purpose of this review is to clearly describe the pathophysiological role therapeutic target of NETs, their interaction with platelets in sepsis, and their potential as therapeutic targets, since it has been shown that a therapeutic approach aimed at curbing NETs would be beneficial

A population pharmacokinetic model of gentamicin in paediatric oncology patients to facilitate improved therapeutic drug monitoring

To ensure the safe and effective dosing of gentamicin in children, therapeutic drug monitoring (TDM) is recommended. TDM utilizing Bayesian forecasting software is recommended but is unavailable, as no population model that describes the pharmacokinetics of gentamicin in pediatric oncology patients exists. This study aimed to develop and externally evaluate a population pharmacokinetic model of gentamicin to support personalized dosing in pediatric oncology patients. A nonlinear mixed-effect population pharmacokinetic model was developed from retrospective data. Data were collected from 423 patients for model building and a further 52 patients for external evaluation. A two-compartment model with first-order elimination best described the gentamicin disposition. The final model included renal function (described by fat-free mass and postmenstrual age) and the serum creatinine concentration as covariates influencing gentamicin clearance (CL). Final parameter estimates were as follow CL, 5.77 liters/h/70 kg; central volume of distribution, 21.6 liters/70 kg; peripheral volume of distribution, 13.8 liters/70 kg; and intercompartmental clearance, 0.62 liter/h/70 kg. External evaluation suggested that current models developed in other pediatric cohorts may not be suitable for use in pediatric oncology patients, as they showed a tendency to overpredict the observations in this population. The final model developed in this study displayed good predictive performance during external evaluation (root mean square error, 46.0%; mean relative prediction error, -3.40%) and may therefore be useful for the personalization of gentamicin dosing in this cohort. Further investigations should focus on evaluating the clinical application of this model