Effect of a dedicated inferior vena cava filter retrieval program on retrieval rates and number of patients lost to follow-up

PURPOSEWe aimed to assess the efficacy of a dedicated inferior vena cava (IVC) filter retrieval program on filter retrieval rates and number of patients lost to follow-up.METHODSA dedicated IVC filter retrieval program began in July 2016. This consisted of tracking all patients with retrievable filters placed by interventional radiology (IR). At the time of filter placement, patients were scheduled for a retrieval consult in the IR clinic. Any missed appointments were followed up by a physician assistant. The program was overseen by a single IR physician. To assess this program’s efficacy, we reviewed the records of all patients who had retrievable IVC filters placed by IR nine months prior to and nine months after program initiation. Demographics and clinical factors were then collected and compared. A P value of < 0.05 was considered statistically significant.RESULTSPrior to the program, 76 patients (31 males, 45 females; mean age, 64.2 years) had retrievable filters placed; 75% were placed due to a contraindication to anticoagulation. From this group, five filters were removed (6.6%), 42 patients were lost to follow-up (55.3%), 22 patients died (29.0%), and seven filters were deemed permanent by a physician after placement (9.2%). All five retrievals were successful and no complications were reported. After program initiation, 106 patients (59 males, 47 females; mean age, 58.8 years) had retrievable filters placed; 75.5% were placed due to a contraindication to anticoagulation. In this group, 30 filters were retrieved (retrieval rate 28.3%), 17 patients were lost to follow-up (16%), 23 patients died (21.7%), 28 filters were deemed permanent by a physician after placement (26.4%), and decisions were still pending in eight patients (7.5%). One patient (3.3%) had a minor complication during filter retrieval. Initiation of a filter retrieval program increased our retrieval rate (6.6% vs. 28.3%; P < 0.001) and reduced the number of patients with filters that were lost to follow-up (55.3% vs. 16%; P < 0.001).CONCLUSIONDedicated filter retrieval program is effective in increasing filter retrieval rates and decreasing the number of patients lost to follow-up

Variation in One Residue Associated with the Metal Ion-Dependent Adhesion Site Regulates alpha IIb beta 3 Integrin Ligand Binding Affinity

The Asp of the RGD motif of the ligand coordinates with the beta I domain metal ion dependent adhesion site (MIDAS) divalent cation, emphasizing the importance of the MIDAS in ligand binding. There appears to be two distinct groups of integrins that differ in their ligand binding affinity and adhesion ability. These differences may be due to a specific residue associated with the MIDAS, particularly the beta 3 residue Ala(252) and corresponding Ala in the beta 1 integrin compared to the analogous Asp residue in the beta 2 and beta 7 integrins. Interestingly, mutations in the adjacent to MIDAS (ADMIDAS) of integrins alpha 4 beta 7 and alpha L beta 2 increased the binding and adhesion abilities compared to the wild-type, while the same mutations in the alpha 2 beta 1, alpha 5 beta 1, alpha V beta 3, and alpha IIb beta 3 integrins demonstrated decreased ligand binding and adhesion. We introduced a mutation in the alpha IIb beta 3 to convert this MIDAS associated Ala252 to Asp. By combination of this mutant with mutations of one or two ADMIDAS residues, we studied the effects of this residue on ligand binding and adhesion. Then, we performed molecular dynamics simulations on the wild-type and mutant alpha IIb beta 3 integrin beta I domains, and investigated the dynamics of metal ion binding sites in different integrin-RGD complexes. We found that the tendency of calculated binding free energies was in excellent agreement with the experimental results, suggesting that the variation in this MIDAS associated residue accounts for the differences in ligand binding and adhesion among different integrins, and it accounts for the conflicting results of ADMIDAS mutations within different integrins. This study sheds more light on the role of the MIDAS associated residue pertaining to ligand binding and adhesion and suggests that this residue may play a pivotal role in integrin-mediated cell rolling and firm adhesion

Dural Septation on the Inner Surface of the Jugular Foramen: An Anatomical Study

Introduction Preserving cranial nerve (CN) function during tumor removal at the jugular foramen is challenging. No anatomical study has better defined the relevant dural septations on the inner surface of the jugular foramen. This study was undertaken to elucidate this anatomy. Methods Fourteen cadaveric heads (28 sides) were dissected, and relationships of the meningeal coverings of the jugular foramen and adjacent CNs documented. A classification scheme was created to better describe the dural septations of the inner surface of the jugular foramen. Results Four types of dural septations were noted. Type I: 10 sides (36%) where a dural septation was seen between CNs IX anteriorly and X and XI posteriorly. Of these, the septum was ossified in 20%. Type II (32%) was defined as a jugular foramen with no dural septation. Type III (7%) was defined as septation between CNs IX and X anteriorly and XI posteriorly. Type IV (7 sides, 25%) or the chaotic form was defined as multiple septations within the jugular foramen that housed and divided CN rootlets. Conclusions The dural septations defined here can be used in future studies to help correlate operative strategy to meningeal morphology within the jugular foramen

Soluble Ligand Binding with PAC-1 and Fibrinogen.

<p>Cells were incubated with (A) PAC-1 in the presence of 5 mM Ca²⁺ or 1 mM Mn²⁺ or (B) FITC-fibrinogen in the presence of 5 mM Ca²⁺ or 1 mM Mn²⁺ as indicated. Binding activities were determined by flow cytometry and expressed as described in Materials and Methods. Error bars are standard deviation (SD). An unpaired t-test with n=1000 for each group was conducted and showed to be statistically significant with a p-value <0.05 between WT and A252D for PAC-1 binding in Mn²⁺ conditions and fibrinogen binding in both Ca²⁺ and Mn²⁺ conditions, between WT and A252D/D126A as well as WT and A252D/D127A for PAC-1 and fibrinogen binding in both Ca²⁺ and Mn²⁺ conditions, and between A252D and A252D/D126A as well as A252D and A252D/D127A for PAC-1 and fibrinogen binding in Ca²⁺ conditions. However, insignificant results with a p-value >0.05 occurred between WT and A252D for PAC-1 binding in Ca²⁺ conditions and between A252D and A252D/D126A as well as A252D and A252D/D127A for PAC-1 and fibrinogen binding in Mn²⁺ conditions.</p

Cell adhesion and spreading.

<p>A. Adhesion of HEK293T transfectants to surfaces coated with 20 µg/mL fibrinogen. The amount of bound cells was determined by measuring LDH activity as described in Materials and Methods. Data are representative of three independent experiments, each in triplicate. Error bars are SD. B. Quantification of the areas of adhering/spreading cells as described in Materials and Methods. C. DIC images of HEK293T transfectants after adhering to immobilized fibrinogen at 37°C. a: WT; b: A252D; c: A252D/D126A; d: A252D/D127A; e: A252D/D126A/D127A. The images are representatives of three independent experiments.</p

The view of the RGD binding site.

<p>Final snapshots of the RGD binding site in (a) wild-type (WT) and mutant (b) A252D, (c) A252D/D126A, (d) A252D/D127A, (e) A252D/D126A/D127A from the molecular dynamics simulations in Mg²⁺-Ca²⁺-Ca²⁺ state. Ligand is shown in stick and colored cyan. N and O atoms involved in metal coordinating are colored in blue and red, respectively. Mg²⁺ is green, Ca²⁺ ions are yellow, and coordinating water molecules are red. Polar coordination between O atoms and metal ions are shown by dashed black lines.</p

Successful surgical treatment of intractable hemifacial spasm: A case report and review of cerebellar hamartomas of the floor of the fourth ventricle

Introduction: Hamartomas involving the floor of the fourth ventricle and cerebellum are rare, but can be associated with medically recalcitrant hemifacial spasm. These lesions present early in the neonatal or infantile period and respond well to surgical excision. Case Report: A 3-month-old white male presented with recurrent left hemifacial spasm, left eye deviation, and absent movement of the extremities. The patient was found to have a left eccentric lesion in the floor of the fourth ventricle and cerebellum. The patient showed no improvement with medical therapy by 6 months of age. He was taken to the operating room for suboccipital craniotomy and removal of the posterior arch of C1 followed by intralesional recording of epileptogenic activity and gross total resection of the lesion. After histologic analysis, the lesion was determined to be ectopic cerebral tissue consistent with a hamartoma. Postoperative MRI showed complete removal of the lesion, and the patient exhibited complete remission of his hemifacial spasm and associated symptoms. Conclusions: Hamartomas involving the floor of the fourth ventricle can present with hemifacial spasm and respond well to surgical excision. Keywords: Cerebellar, Seizure, Epilepsy, Hamartom

Expression of WT and Mutant αIIbβ3 Integrins.

<p>Immunofluorescent flow cytometry. HEK293T transfectants were labeled with AP3 (anti-β3), 7E3 (anti-β3), 10E5 (anti-αIIb), and LM609 (anti-αV). Thick and thin lines show labeling of the αIIbβ3 transfectant and the mock transfectant, respectively.</p

The distributions of the eigenvalues on the first, second, and third principal components (PC).

<p>The distributions of the eigenvalues on the PC1, PC2, and PC3 are demonstrated for Mg²⁺-Ca²⁺-Ca²⁺ [(a), (b), and (c)] and Mn²⁺-Mn²⁺-Mn²⁺ [(d), (e), and (f)] states.</p