Plantar vein thrombosis: 17-year longitudinal study of consecutive patients from a Swiss academic center

BACKGROUND Plantar vein thrombosis (PVT) is a rare condition. Less than 50 cases have been described in the literature. Evidence from interventional and observational studies is sparse or lacking. OBJECTIVES To describe a consecutive cohort of patients diagnosed with PVT at a single academic institution over the past 17 years. METHODS We searched medical charts from patients managed at the University Hospital Zurich between 2005 and 2022. PVT was detected through sonography (eg, in the presence of a noncompressible deep vein) and/or magnetic resonance (eg, a vein with a filling defect on non-contrast-enhanced or contrast-enhanced imaging). The study was approved by the local ethics commission. RESULTS We identified 45 patients who had been assessed for PVT. After manual check of these cases, we selected 16 patients with a confirmed, objective diagnosis. Median age was 62 (25th-75th percentiles, 46-73) years, and 9 (56%) patients were women. All patients were symptomatic, usually reporting local pain in the foot (100%) and swelling (67%). The most frequent risk factors were cancer (n = 6; 38%) and prior deep vein thrombosis (n = 4; 25%). Overall, 80% of patients received oral anticoagulation and 20% received parenteral anticoagulation for a median of 90 days. Over a median follow-up of 17 months, 2 (12.5%) recurrent venous thromboembolism events were recorded following the discontinuation of anticoagulation. Index vein recanalization occurred in all 15 survivors. One patient died from cancer 2 years after PVT diagnosis. CONCLUSION We provided initial information on the clinical characteristics, treatment, and course of PVT, which partly resembles that of distal deep vein thrombosis

Катетерный тромболизис в лечении острого венозного илиофеморального тромбоза в Дании

ТРОМБОЛИТИЧЕСКАЯ ТЕРАПИЯКАТЕТЕРИЗАЦИЯТРОМБОЗ ВЕНОЗНЫЙ /ЛЕК ТЕРКОНЕЧНОСТЬ НИЖНЯ

The effect of locally induced flow structure on global heat transfer for plane laminar shear flow

Heat transfer in a plane laminar shear flow configuration consisting of two infinitely long plates orientated parallel to each other is investigated theoretically. The upper plate, which is planar, drives the flow; the lower one, which is fixed, has a regular sinusoidally varying profile. A closed form analytical solution for velocity, based on lubrication theory, together with a semi–analytic one for temperature, from application of Ritz’s direct method, is derived for creeping flow. In addition, detailed numerical solutions are obtained from a finite element formulation of the weak form of the governing equations for mass, momentum and energy (temperature) conservation, enabling the effects of inertia to be explored. It is shown that changes in the mean plate separation, that is the geometry, and the level of inertia present affect the local hydrodynamic flow structure in the form of kinematically and inertially induced eddies, respectively. These in turn impact on the local ”laminar thermal mixing”, and consequently enhance the global heat transfer. Results are reported for a wide range of Pecl´et, Reynolds and Nusselt numbers with agreement between the two methods of solution, for the case of creeping flow, found to be extremely good. The key flow features that emerge are: (i) For creeping flow and varying Pecl´et number, the thermal field is asymmetric for all values of the Pecl´et number other than the limiting conditions of zero and infinity, at which extremes the corresponding thermal field is symmetric. In the limit of infinite Pecl´et number the eddy becomes a basin of fluid at uniform temperature. (ii) Global heat transfer in the case of creeping flow, expressed in terms of the Nusselt number, for a given Pecl´et number increases as the mean plate separation decreases, that is as the local kinematically induced eddy structure becomes more pronounced. (iii) There exists a subtle inter–play between variations in the mean plate separation and the level of inertia imposed, in that both influence the presence or otherwise of eddies. Starting from a creeping flow condition the introduction of inertia can in addition both enlarge and skew an existing eddy. When this information is condensed to a series of Nusselt number curves the indication is that it should be possible, from a practical standpoint, to find a critical mean plate separation, for a given Pecl´et number, for which local inertially influenced eddy effects on the global heat transfer are at a minimum

Galacto-Configured Aminocyclitol Phytoceramides Are Potent in Vivo Invariant Natural Killer T Cell Stimulators

A new class of α-galactosylceramide (αGC) nonglycosidic analogues bearing galacto-configured aminocyclitols as sugar surrogates have been obtained. The aminocyclohexane having a hydroxyl substitution pattern similar to an α-galactoside is efficiently obtained by a sequence involving Evans aldol reaction and ring-closing metathesis with a Grubbs catalyst to give a key intermediate cyclohexene, which has been converted in galacto-aminocyclohexanes that are linked through a secondary amine to a phytoceramide lipid having a cerotyl N-acyl group. Natural Killer T (NKT) cellular assays have resulted in the identification of an active compound, HS161, which has been found to promote NKT cell expansion in vitro in a similar fashion but more weakly than αGC. This compound stimulates the release of Interferon-γ (IFNγ) and Interleukin-4 (IL-4) in iNKT cell culture but with lower potency than αGC. The activation of Invariant Natural Killer T (iNKT) cells by this compound has been confirmed in flow cytometry experiments. Remarkably, when tested in mice, HS161 selectively induces a very strong production of IFN-γ indicative of a potent Th1 cytokine profile. Overall, these data confirm the agonist activity of αGC lipid analogues having charged amino-substituted polar heads and their capacity to modulate the response arising from iNKT cell activation in vivo.This work was supported by MICINN (Project CTQ2008–01426/BQU), Fondos Feder (EU), Generalitat de Catalunya (2005SGR01063), UAB (PRP2007–06), and CSIC (200480E561). The authors thank E. Dalmau for HRMS analysis and Dr, M. Egido-Gabas and Dr. Amaya Castro for analytical support. Y.H. thanks MICINN for a Juan de la Cierva fellowship.Peer reviewe

Electrified film flow over step topography at zero Reynolds number.

The flow of a liquid film over step topography under the influence of an electric field is considered in the limit of zero Reynolds number. The particular topographies considered include a flat wall with a downward step or an upward step, or a flat wall which is indented with a rectangular trench. A uniform electric field is imposed at infinity in the direction normal to the flatwall. The air above the film is treated as a perfect dielectric. The liquid in the film is assumed to behave either as a perfect conductor or as a perfect dielectric whose dielectric constant in general differs from that in the air. Asymptotic results are derived on the assumption of small step height, and formulas are presented for the first-order correction to the free-surface deformation due to the topography. It is demonstrated that, in an appropriate long-wave limit, the solutions approach those obtained using the lubrication approximation. Finally, the small-step asymptotics are favourably compared with numerical solutions for Stokes flow over steps of arbitrary height computed using the boundary-element method. In summary, it is shown that asymptotic models based on small-amplitude step topography provide simple formulas which are effective in describing the flow even for moderate step amplitudes, making them an efficient analytical tool for solving practical film-flow problems