Citations

Background With currently available effective interventional methods to treat superficial venous insufficiency, it becomes particularly important to have a simple and reliable method to evaluate the location and severity of venous reflux. To date, there are few studies that evaluated plethysmography with and without tourniquet application to differentiate superficial from deep venous incompetence. Objectives To determine if strain gauge plethysmography (SGP) with and without tourniquet application can be used to distinguish between the superficial and deep venous components of venous incompetence. Methods We conducted a prospective study using SGP with and without tourniquet application and duplex ultrasound (duplex US) to assess the severity and location of venous incompetence in 62 patients (85 limbs, 42 women, with an age range of 32–81 years) referred to our vascular laboratory for haemodynamic evaluation. Based on duplex US results, patients were diagnosed with superficial (SVI), deep and superficial (mixed) and deep vein incompetence (DVI). Results Mixed incompetence was the most common type. Twenty-three out of 33 limbs in the SVI group normalized their refill rate (RR) with tourniquet application (69.6%). Normalization of the RR with tourniquet application was less common in the mixed ( n: 17 out of 40, 42.5%) and DVI ( n: 2 out of 6, 33.3%) groups. Conclusion SGP with tourniquet application is a simple and fast technique that can identify patients with SVI, based on RR improvement, who probably would benefit more from ablation procedures. Further studies evaluating impact of SGP with tourniquet test results on clinical outcome of SVI invasive treatment are warranted

Abstract To test recommended anticoagulation measures as predictors of 180-day venous thromboembolism (VTE) recurrence, we identified all Olmsted County, MN residents with incident VTE over the 14-year period of 1984-1997, and followed each case (N = 1166) forward in time for VTE recurrence. We tested the activated partial thromboplastin time (APTT), international normalized ratio (INR), and other measures of heparin and warfarin anticoagulation as predictors of VTE recurrence while controlling for baseline and time-dependent characteristics using Cox proportional hazards modeling. Overall, 1026 (88%) and 989 (85%) patients received heparin and warfarin, respectively, and 85 (8%) developed VTE recurrence. In multivariable analyses, increasing proportions of time on heparin with an APTT ≥ 0.2 anti-Xa U/mL and on warfarin with an INR ≥ 2.0 were associated with significant reductions in VTE recurrence, while the hazard with active cancer was significantly increased. Time from VTE onset to heparin start, duration of overlapping heparin and warfarin, and inferior vena cava (IVC) filter placement were not independent predictors of recurrence. At a heparin dose ≥ 30 000 U/d, the median proportion of time with an APTT ≥ 0.2 anti-Xa U/mL was 92%, suggesting that routine APTT monitoring and heparin dose adjustment may be unnecessary. In summary, lower-intensity heparin and standard-intensity warfarin anticoagulation are effective in preventing VTE recurrence.

The response of an embedded sphere in a viscoelastic medium excited by acoustic radiation force has been studied in both the time- and frequency-domains. This model is important because it can be used to characterize the viscoelastic properties of the medium by fitting the response to the theoretical model. The Kelvin–Voigt model has been used exclusively in these models. An extension to the previously reported models is described so that any viscoelastic rheological model can be used. This theoretical development describes the generalized embedded sphere response both in the time and frequency domains. Comparing the results from derivations in both domains showed very good agreement with a median absolute error (MAE) ranging from 0.0044 to 0.0072. Good agreement is demonstrated with finite element model simulations and the theory with a MAE of 0.006. Lastly, results for characterization of gelatin and rubber materials with the new theory are shown where the MAE values were used to determine which rheological model best describes the measured responses.

Abstract Purpose: Oncolytic viruses are self-amplifying anticancer agents that make use of the natural ability of viruses to kill cells. Adenovirus serotype 5 (Ad5) has been extensively tested against solid cancers, but less so against B-cell cancers because these cells do not generally express the coxsackie and adenoviral receptor (CAR). To determine whether other adenoviruses might have better potency, we “mined” the adenovirus virome of 55 serotypes for viruses that could kill B-cell cancers. Experimental Design: Fifteen adenoviruses selected to represent Ad species B, C, D, E, and F were tested in vitro against cell lines and primary patient B-cell cancers for their ability to infect, replicate in, and kill these cells. Select viruses were also tested against B-cell cancer xenografts in immunodeficient mice. Results: Species D adenoviruses mediated most robust killing against a range of B-cell cancer cell lines, against primary patient marginal zone lymphoma cells, and against primary patient CD138+ myeloma cells in vitro. When injected into xenografts in vivo, single treatment with select species D viruses Ad26 and Ad45 delayed lymphoma growth. Conclusions: Relatively unstudied species D adenoviruses have a unique ability to infect and replicate in B-cell cancers as compared with other adenovirus species. These data suggest these viruses have unique biology in B cells and support translation of novel species D adenoviruses as oncolytics against B-cell cancers. Clin Cancer Res; 17(21); 6712–22. ©2011 AACR.

Renal vein compression syndromes are rare causes of hematuria and can be divided into anterior and posterior nutcracker syndrome. When the left renal vein is compressed between the aorta and the superior mesenteric artery it causes anterior nutcracker syndrome. The posterior nutcracker syndrome is very rare and is considered when the left renal vein is compressed between the aorta and vertebral column. Symptoms of nutcracker syndromes may include intermittent left flank pain associated with hematuria, proteinuria, and sometimes with symptoms of pelvic congestion. Diagnosis is often difficult and plan for treatment is always challenging and requires careful evaluation of the patient’s history and workup findings. We present a rare case report of a posterior nutcracker syndrome diagnosed in a young lady with long-standing symptoms that required surgical intervention.

Reductions in oxygen availability (O2) by either reduced arterial O2content or reduced perfusion pressure can have profound influences on the circulation, including vasodilation in skeletal muscle vascular beds. The purpose of this review is to put into context the present evidence regarding mechanisms responsible for the local control of blood flow during acute systemic hypoxia and/or local hypoperfusion in contracting muscle. The combination of submaximal exercise and hypoxia produces a “compensatory” vasodilation and augmented blood flow in contracting muscles relative to the same level of exercise under normoxic conditions. A similar compensatory vasodilation is observed in response to local reductions in oxygen availability (i.e., hypoperfusion) during normoxic exercise. Available evidence suggests that nitric oxide (NO) contributes to the compensatory dilator response under each of these conditions, whereas adenosine appears to only play a role during hypoperfusion. During systemic hypoxia the NO-mediated component of the compensatory vasodilation is regulated through a β-adrenergic receptor mechanism at low-intensity exercise, while an additional (not yet identified) source of NO is likely to be engaged as exercise intensity increases during hypoxia. Potential candidates for stimulating and/or interacting with NO at higher exercise intensities include prostaglandins and/or ATP. Conversely, prostaglandins do not appear to play a role in the compensatory vasodilation during exercise with hypoperfusion. Taken together, the data for both hypoxia and hypoperfusion suggest NO is important in the compensatory vasodilation seen when oxygen availability is limited. This is important from a basic biological perspective and also has pathophysiological implications for diseases associated with either hypoxia or hypoperfusion.

A newly identified gene fusion defines the vascular cancer epithelioid hemangioendothelioma and encodes a chimeric transcription factor.

Abstract The POEMS syndrome is associated with elevated vascular endothelial growth factor (VEGF) levels. Several studies have compared serum VEGF levels between POEMS patients and other disease entities showing higher serum VEGF in POEMS syndrome; however, it is unknown whether serum levels are reliable and reproducible given variable platelet release of VEGF. We therefore compared plasma levels of VEGF in 29 patients with POEMS syndrome with those of other disorders (n = 76). We demonstrated that plasma VEGF levels are useful in differentiating POEMS from other plasma cell dyscrasias, neuropathic processes, and multisystem illnesses. Plasma VEGF is also useful in monitoring disease activity after treatment and correlates with clinical improvements better than hematologic response.