Transvenous Embolizations of Venous Compartments of Dural Arteriovenous Fistulas within Venous Sinus Walls

Transvenous embolization of venous compartments within the venous sinus wall was the method initially attempted for closing dural arteriovenous fistulas in 15 patients (22 sinuses). The venous channel, separate from the sinus lumen and located in the venous sinus wall, could be embolized in 6 lesions (3 patients), including 3 superior sagittal sinus fistulas, 2 transverse sinus fistulas, and 1 straight sinus fistula.

This technique resulted in closure of the fistulas and preservation of sinus patency as well as immediate improvement of clinical symptoms. The embolizable venous compartment of the fistula within the venous sinus wall could be detected by preoperative angiography, magnetic resonance imaging, and intraoperative venography. This unique drainage of dural arteriovenous fistulas may develop concurrently with more obvious portions of the fistula.

Transvenous embolization of these venous compartments can close the fistulas and normalize impaired sinus function.

Assessing the clinical severity of type 1 von Willebrand disease patients with a microchip flow-chamber system

BACKGROUND

The clinical phenotype of von Willebrand disease (VWD) is heterogeneous, and von Willebrand factor ristocetin cofactor activity (VWF:RCo) does not always reflect clinical severity, especially in VWD type 1. We have reported the potential of a microchip flow-chamber system (Total-Thrombus Formation Analysis System [T-TAS®]) for assessing physiologic hemostasis in VWD. Aim To evaluate the relationship between T-TAS, bleeding score (BS) and laboratory test results in type 1 VWD patients.

METHODS

Microchips coated with collagen (platelet chip [PL-chip]) or collagen/thromboplastin (AR-chip) were used to assess platelet thrombus formation (PTF) at high shear rates or fibrin-rich PTF at low shear rates, respectively, in whole blood from 50 patients. The times needed for the flow pressure to increase by 10 kPa and 30 kPa (T10 and T30 ) from baseline were calculated from flow pressure curves. BS was determined by the use of a standardized questionnaire.

RESULTS

PL-T10 values correlated with BS (R(2) ~ 0.45) better than VWF:RCo (R(2) ~ 0.36), irrespective of the flow rate, whereas AR-T10 showed only a weak correlation with BS (R(2) ~ 0.18). Patients with PL-T10 > 10 min or AR-T10 > 30 min had lower VWF levels and higher BS than those with PL-T10 ≤ 10 min or AR-T10 ≤ 30 min, and the greatest differences were observed with PL-T10. Clinical severity appeared to correlate best with PL-T10 > 8 min. BS was significantly higher in patients with VWF:RCo of < 10 IU dL(-1) than in those with VWF:RCo of 10 IU dL(-1) to < 25 IU dL(-1) and 25-40 IU dL(-1). In patients with VWF:RCo of < 10 IU dL(-1) , BS was significantly higher in those with PL-T10 > 8 min than in those with PL-T10 ≤ 8 min.

CONCLUSION

T-TAS could be a useful technique for discriminating and predicting BS in VWD type 1 patients.

0.43 THz emission from high-T(c) superconducting emitters optimized at 77 K

A liquid helium-free, compact and continuous sub-terahertz radiation system operating at 77 K has been developed using a rectangular mesa device made from a high T(c)-superconducting Bi2Sr2CaCu2O(8+δ) single crystal, based on a different design of a stand-alone mesa sandwich structure to reduce the dc-current Joule heating effects. The mesa was thermally connected to sapphire plates through thin thermal grease embedded with diamond nano-crystals. When immersed in liquid N 2, the device emits intense radiation at 0.437 THz, the highest frequency ever achieved at 77 K, due to excitation of the TM(1, 0) rectangular cavity mode. By varying the dc current-voltage bias and the bath temperature in a He-flow cryostat, the device's emission frequency is broadly tunable from 0.31 THz at 79 K to 1.31 THz at 30 K.

Influence of the molecular-oriented structure of ionic liquids on the crystallinity of aluminum hydroxide prepared by a sol-gel process in ionic liquids

The influence of the structure of ionic liquids on the crystallinity of aluminum hydroxide (Al(OH)3) prepared by a sol-gel process with aluminum isopropoxide (Al(OPr(i))3) in imidazolium-based ionic liquids was investigated. When Al(OH)3 was prepared in ionic liquids having long alkyl chains, such as 1-butyl-3-methylimidazolium salts and 1-methyl-3-octylimidazolium salts, highly crystalline products were obtained. In contrast, Al(OH)3 obtained using the 1-ethyl-3-methylimidazolium salt was an amorphous material, indicating that hydrophobic interaction of the alkyl tail of the imidazolium cation of the ionic liquid strongly affects the crystallinity of sol-gel products and the local structure of the ionic liquid. Moreover, the crystallinity of Al(OH)3 prepared in ionic liquids increased relative to the amount of additional water (ionic liquid/water = 1.28/2.0-3.5/0.2, w/w). In the case of addition of a small amount of water (ionic liquid/water = 3.5/0.2, w/w), the product was amorphous. These results implied that the presence of an ionic liquid and a sufficient amount of water was crucial for the successful synthesis of sol-gel products with high crystallinity. (1)H NMR analyses revealed a shift of the peak associated with the imidazolium cation upon addition of water, which suggested that the molecular orientation of the ionic liquid was similar to that of a micelle.

Systematic monitoring of hemostatic management in hemophilia A patients with inhibitor in the perioperative period using rotational thromboelastometry

BACKGROUND

The management of hemophilia A (HA) patients with inhibitors on bypassing therapy remains challenging. In particular, the monitoring of treatment is restricted by the limited reliability and lack of standardization of currently available methods to evaluate the physiological effects of various hemostatic agents. Accurate monitoring of these patients is particularly important in surgical situations. The recently developed comprehensive coagulation assays, including rotational thromboelastometry (ROTEM), may be useful in these circumstances.

OBJECTIVE

We have attempted to establish a systematic monitoring protocol using ROTEM (NATEM triggered by CaCl2 ) to evaluate the choice and effectiveness of different bypassing agents in the perioperative period.

METHODS AND RESULTS

The hemostatic effects of recombinant factor VIIa (rFVIIa) and activated prothrombin complex concentrates (aPCC) were determined using a three-step procedure (spike, preoperative and perioperative) in eight patients with HA inhibitor admitted for elective surgery and assessed for individually tailored therapy. The ROTEM parameters demonstrated similar improvement to approximately normal levels at each stage after treatment with rFVIIa. Results in the presence of aPCC showed a marked improvement in the spike data, although this appeared to be different from those in the preoperative and perioperative assessments. The information derived from the spike and preoperative findings provided a useful guide for establishing an effective dose of therapeutic material, and facilitated good hemostatic control during and after surgery in all cases.

CONCLUSION

The findings suggest that this systematic analysis using ROTEM could provide a promising strategy for the use of bypassing therapy in HA patients with inhibitor.

Significance of background coloration in endoscopic detection of early esophageal squamous cell carcinoma

Endoscopic diagnostics of early squamous cell carcinoma (SCC) in the laryngo-esophageal region have dramatically improved together with development of less invasive endoscopic treatment. It is essential for gastrointestinal endoscopists to detect lesions when they are still endoscopically treatable, especially in this region since surgical approach can still be extremely invasive. Pioneers have found some notable fundamental alterations in early SCC and created several classifications. Inoue [Dig Endosc 2001;13(suppl): 40-41] proposed the intrapapillary capillary (IPCL) classification, which focused on the microvascular change of the mucosal surface. One of the significances of this classification is that it clearly distinguished the lesions that require further pathological evaluation by categorizing the diameter change of the IPCLs. On the other hand, Arima et al. [Esophagus 2005;2:191-197] advocated the alteration of microvessels as well as change of the vascular arrangement in the area. Most recently, the Japan Esophageal Society constructed a new classification uniting these two exemplary classifications as the 'Japanese Classification of Magnifying Endoscopy for Early Squamous Cell Carcinoma'. This classification was intended to be simple and easily applicable in general clinical practice. Brownish color change between the IPCLs has reported to be one of the useful findings in distinguishing early SCC from benign changes such as inflammatory change and low-grade intraepithelial neoplasia. Nevertheless, the exact cause of this phenomenon remains unclear. We recently examined the association of color change with hemoglobin (Hb) in cancer tissue, since NBI exclusively detects the wavelength of Hb in superficial vessels in the gastrointestinal tract. This review article also describes our examination of a distinct finding in esophageal cancer, namely, 'background coloration'.

Spectral investigation of hot spot and cavity resonance effects on the terahertz radiation from high-T(c) superconducting Bi2Sr2CaCu2O(8+δ) mesas

Terahertz (THz) electromagnetic radiation emitted from single and series-connected rectangular mesa devices of high-Tc superconducting Bi2Sr2CaCu2O8+δ is investigated spectroscopically during simultaneous temperature distribution observations using a microcrystalline SiC photoluminescence technique. In single mesas, a hot-spot region with its temperature T locally exceeding Tc was observed to jump suddenly in position under small current I-bias changes. Although these hot-spot position jumps cause large changes in the output power with small changes in I, as long as the voltage V per junction number N is kept constant, they do not affect the output frequency f, which is given by the ac Josephson frequency fJ. f can lock onto that of a particular mesa cavity resonance frequency fc, which enhances the emission power and serves as the primary mechanism for the synchronization of the emissions from each of the intrinsic Josephson junctions in the mesa.

One-step synthesis of “rattle-like” polymer particles via suspension polymerization

Multiple particles in a polymer shell, i.e. “rattle-like” capsules, have the potential to be used in electric ink or vibro-isolating and sound absorption materials because the encapsulated small particles are movable independently. Here, we demonstrate one-step preparation of the capsules containing small particles. In the final products, encapsulated particles were movable inside the capsule.

A randomized multicenter phase II trial on the efficacy of a hydrocolloid dressing containing ceramide with a low-friction external surface for hand-foot skin reaction caused by sorafenib in patients with renal cell carcinoma

BACKGROUND

The purpose of this study was to investigate the usefulness of a hydrocolloid dressing containing ceramide for hand-foot skin reaction (HFSR) on the soles of the feet in metastatic renal cell carcinoma (RCC) patients treated with sorafenib.

PATIENTS AND METHODS

Patients with grade 1 HFSR on the soles of the feet were randomly assigned in to two groups. One group received a hydrocolloid dressing containing ceramide (arm A) and the other received 10% urea cream (arm B). Patients in both groups applied treatment to the affected sites on the soles of the feet, but not to the hands. The primary end point was the incidence of grade 2 or 3 HFSR on the soles of the feet in the first 4 weeks.

RESULTS

Thirty-three patients were assessed (17 in arm A and 16 in arm B), and there were no significant differences in baseline characteristics between the two groups. During the observation period of this study, grade 2 or 3 HFSR on the soles of the feet was found in 29% of patients in arm A and was significantly less than the 69% in arm B (P=0.03). The incidence of HFSR on the hands, however, was similar in both arms. The median time to grade 2 or 3 HFSR on the soles of the feet was also significantly longer in arm A than in arm B (P=0.03).

CONCLUSIONS

These results indicate that a hydrocolloid dressing containing ceramide prevented the worsening of HFSR caused by sorafenib in metastatic RCC patients.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000002016.

Tunable terahertz emission from the intrinsic Josephson junctions in acute isosceles triangular Bi₂Sr₂CaCu₂O₈+δ mesas

In order to determine if the mesa geometry might affect the properties of the coherent terahertz (THz) radiation emitted from the intrinsic Josephson junctions in mesas constructed from single crystals of the high-temperature superconductor, Bi₂Sr₂CaCu₂O₈+δ, we studied triangular mesas. For equilateral triangular mesas, the observed emission was found to be limited to the single mesa TM(1,0) mode. However, tunable radiation over the range from 0.495 to 0.934 THz was found to arise from an acute isosceles triangular mesa. This 47% tunability is the widest yet observed from the outer current-voltage characteristic branch of such mesas of any geometry. Although the radiation at a few of the frequencies in the tunable range appear to have been enhanced by cavity resonances, most frequencies are far from such resonance frequencies, and can only be attributed to the ac-Josephson effect.

Moyamoya disease associated with basilar tip aneurysm

Direct surgical intervention to treat ruptured basilar tip aneurysms in patients with moyamoya disease has rarely been attempted, and patients who have undergone such treatment have not fully recovered. We review six cases of surgically treated ruptured basilar tip aneurysm associated with moyamoya disease, including our own case to illustrate aspects of surgical intervention and the difficulties encountered. Patients who underwent surgery after 4 weeks of the onset of symptoms showed impressive results. Of the patients who underwent surgery in the acute stage, two died, including our patient, and one showed excellent recovery. It is emphasized that to achieve satisfactory surgical outcome, the following factors should be considered: (i) delayed operation is preferable, with extracranial-intracranial bypass in selected patients; (ii) careful preservation of moyamoyas and transdural collaterals is mandatory; (iii) intraoperative rupture of the aneurysm should be avoided; and (iv) using a neuroanaesthetic technique of induced hypothermia and hypertension may be preferable.