35 research outputs found
Thyroglossal Duct Lipoma: A Case Report and a Systematic Review of the Literature for Its Management
Thyroglossal duct (TGD) remnants in the form of cysts or fistulas usually present as midline neck masses and they are removed along with the central body of the hyoid bone (Sistrunk’s procedure). For other pathologies associated with the TGD tract, the latter operation might be not necessary. In the present report, a case of a TGD lipoma is presented and a systematic review of the pertinent literature was performed. We present the case of a 57-year-old woman with a pathologically confirmed TGD lipoma who underwent transcervical excision without resecting the hyoid bone. Recurrence was not observed after six months of follow-up. The literature search revealed only one other case of TGD lipoma and controversies are addressed. TGD lipoma is an exceedingly rare entity whose management might avoid hyoid bone excision
Analysis of Familial Hemophagocytic Lymphohistiocytosis type 4 (FHL-4) mutant proteins reveals that S-acylation is required for the function of syntaxin 11 in natural killer cells
Natural killer (NK) cell secretory lysosome exocytosis and cytotoxicity are impaired in familial hemophagocytic lymphohistiocytosis type 4 (FHL-4), a disorder caused by mutations in the gene encoding the SNARE protein syntaxin 11. We show that syntaxin 11 binds to SNAP23 in NK cells and that this interaction is reduced by FHL-4 truncation and frameshift mutation proteins that delete all or part of the SNARE domain of syntaxin 11. In contrast the FHL-4 mutant proteins bound to the Sec-1/Munc18-like (SM) protein Munc18-2. We demonstrate that the C-terminal cysteine rich region of syntaxin 11, which is deleted in the FHL-4 mutants, is S-acylated. This posttranslational modification is required for the membrane association of syntaxin 11 and for its polarization to the immunological synapse in NK cells conjugated to target cells. Moreover, we show that Munc18-2 is recruited by syntaxin 11 to intracellular membranes in resting NK cells and to the immunological synapse in activated NK cells. This recruitment of Munc18-2 is abolished by deletion of the C-terminal cysteine rich region of syntaxin 11. These results suggest a pivotal role for S-acylation in the function of syntaxin 11 in NK cells
Aspetti del controllo sulle leggi e i regolamenti regionali. Italia e Spagna a confronto
Performance Evaluation of MANETs Using Smart Antennas in Multipath Fading Environment
This paper investigates the performance of a MANET where nodes are
equipped with fully adaptive smart antennas. The physical antenna
system is a uniform circular array and the signal processing unit,
employing LMS algorithm, uses a reference signal to update the
antenna weights. A comparison between a MAC protocol called
Selective CSMA with Cooperative Nulling (SCSMA/CN) and 802.11 DCF
shows that higher throughput can be obtained exploiting efficient
SDMA schemes. The objective of this paper is to extend, via
simulations, the considerations on interferer suppression
capabilities of smart antennas in more severe channel conditions.
So, the link model takes into account path loss, cochannel
interference and multipath fading, using a modified Jakes model.
Simulation results show the performance degradation due to
increase of angular spread in multipath channels due to
difficulties of smart antennas in placing nulls towards undesired
directions. Moreover, this paper puts into evidence the effects of
fading on network throughput in mobility scenario
Simultaneous Communications in Ad-Hoc Networks Using Smart Antennas in Multipath Environment
This paper analyzes the maximum number of simultaneous
communications that can be sustained by an ad-hoc network in which
the nodes are equipped with fully adaptive smart antennas. The
study proposes an analytical model for the evaluation of the
performance of ad hoc networks which includes multipath together
with some characteristics of the access scheme. The main goal is
the analysis of the relationship between the angular spread of the
channel and the transmission policy ruled at MAC layer. Moreover,
in the paper, it is examined the influence of the spatial channel
model on network performance