Transluminal angioplasty and intra-arterial papaverine for the treatment of cerebral vasospasm after ruptured arteriovenous malformations

BACKGROUND: This is the first report on the use of intra-arterial papaverine and percutaneous transluminal angioplasty in two patients with severe, symptomatic cerebral vasospasm who suffered ruptured arteriovenous malformations (AVMs). CASE DESCRIPTIONS: The source of hemorrhage was a venous aneurysm in the first case and a pedicular aneurysm of the distal posterior inferior cerebellar artery in the second case. In both cases, the AVMs were located in the superior vermis and there was minimal subarachnoid hemorrhage. The first patient underwent removal of the AVM before the period of cerebral vasospasm and the second patient underwent removal of the AVM after the cerebral vasospasm had resolved. The outcome was excellent in the first patient and poor in the second patient. CONCLUSION: Arteriovenous malformation with ruptured aneurysms may be at high risk for cerebral vasospasm even when there is minimal subarachnoid hemorrhage. We recommend early treatment of AVMs with ruptured pedicular, intranidal, or venous aneurysms to avoid rebleeding and to allow for aggressive treatment of cerebral vasospasm. The management of cerebral vasospasm after AVM rupture is discussed.     

Effects of test conditions on the outcome of place conditioning with morphine and naltrexone in mice

BACKGROUND: Although it is widely proposed that surgeons, before introducing a novel laparoscopic technique in man, should practice in an appropriate animal model for acquisition of the necessary technical skills, the effectiveness of those hands-on training courses are rarely documented. METHODS: In 1995 we have organized eight hands-on training courses for laparoscopic anterior interbody spine fusion in an in vivo porcine model. A total of 72 colleagues from 50 different centers of 12 countries participated, including orthopedic, trauma, visceral, neuro-, and vascular surgeons. Quality and effectiveness of the course were evaluated by a questionnaire after a 1.5- to 2.5-year period. RESULTS: During this time, 42.2% of the participating centers had applied the new technique successfully in man. Centers which participated in the course with a team that included a skilled laparoscopic surgeon and an orthopedic or trauma surgeon introduced the technique more frequently to clinical practice (57.9%) than those represented by only one participant (30. 8%). Moreover, there was a tendency toward a more frequent introduction of the technique to clinical practice in centers associated with university hospitals (57.1% vs. 29.2%), indicating the requirement of a particular infrastructure for this complex interdisciplinary procedure. Almost all participants (98.3%) agreed that for novel surgical techniques requiring advanced technical skills, there should first be training in a large animal model before the technique is applied in man. CONCLUSIONS: Complex laparoscopic procedures (i.e., laparoscopic spine surgery) can be successfully learned by in vivo hands-on training courses. We propose that for refinements and modifications of the technique (e.g. , the lumboscopic approach), there should also first be training in a large animal model before these are applied in man.     

XYΘ actuators using piezoelectric and electromagnetic actuators

Microactuators with multiple degrees of freedom, which can provide many benefits in precision engineering, are in demand for industrial applications. We propose two new actuators (Y‐type and Δ‐type) which can move in the x, y, and θ directions. They are combinations of piezoelectric and electromagnetic actuators. The proposed actuators realize high resolution via the piezoelectric actuators. We describe the structure and principle of the proposed actuators, and discuss their feasibility. A resolution of 70 nm in the x direction and of 0.5 μrad in the θ direction was obtained with the Y‐type actuator. A resolution of 90 nm in the x direction and of 0.6 μrad in the θ direction was obtained with the Δ‐type actuator. © 2000 Scripta Technica, Electr Eng Jpn, 131(4): 44–51, 2000     

Design of an Artificial Peptide Inspired by Transmembrane Mitochondrial Protein for Escorting Exogenous DNA into the Mitochondria to Restore their Functions by Simultaneous Multiple Gene Expression

Mitochondria are vital organelles regulating essential cellular functions. Human mitochondrial DNA (mtDNA) consists of 37 genes, 13 of which encode mitochondrial proteins, and the remaining 24 genes encode two ribosomal RNAs and 22 transfer RNAs needed for the translation of the mtDNA-encoded 13 proteins. However, mtDNA often impairs the expression and function of these genes due to various mutations, ultimately causing mitochondrial dysfunction. To recover from this desperate condition, developing the technology to supply all mitochondrial proteins encoded by mtDNA at once is an urgent task, but there is no established strategy for this purpose. In this study, a simple yet effective mitochondrial gene delivery system is proposed comprising an artificial peptide inspired by a transmembrane mitochondrial membrane protein. The designed mitochondria-targeting peptides presented on the carrier surface effectively guide the encapsulated plasmid to the mitochondria, facilitating mitochondrial uptake and gene expression. The developed system successfully delivers exogenous mtDNA to mtDNA-depleted cells and leads to simultaneous multigene expression, ultimately restoring mitochondrial functions, including the mitochondrial respiration rate. The established multiple gene expression system in each mitochondrion is a game-changing technology that can accelerate the development of mitochondrial engineering technologies as well as clinical applications for mitochondrial diseases.     

Is impaired cerebral vasomotor reactivity a predictive factor of stroke in asymptomatic patients?

BACKGROUND AND PURPOSE: Identification of the subgroup of asymptomatic patients with severe internal carotid artery stenosis and high risk of stroke has important clinical implications. Cerebral vasomotor reactivity provides information regarding intracranial hemodynamic features and might have a prognostic value in predicting cerebrovascular ischemic events, especially in patients with carotid stenosis. The aim of our study was to assess the cerebral vasomotor reactivity in asymptomatic patients with carotid stenosis and evaluate its role in stroke occurrence. METHODS: Cerebral vasomotor reactivity was assessed using transcranial Doppler ultrasonology and the Diamox test (intravenous administration of 1.0 g acetazolamide) in 44 asymptomatic patients with severe (> 70%) internal carotid artery stenosis. Patients were followed up prospectively (mean, 2 years). RESULTS: Cerebral vasomotor reactivity was estimated as good (> 40% increase of blood flow velocity in the middle cerebral artery ipsilateral to the carotid stenosis after undergoing the Diamox test) in 23 patients; it was impaired in the other 21. During the follow-up period, the overall annual rate for ipsilateral stokes was 2.3%; it was 7.9% for all ischemic cerebral events. No strokes or transient ischemic attacks occurred in the former group, but there were 7 cerebral ischemic events (2 strokes [1 fatal] and 5 transient ischemic attacks) in the latter group. There was a statistically significant correlation between cerebral ischemic events and impaired cerebral vasomotor reactivity (P = .009). CONCLUSIONS: The data of this preliminary study suggest an important role of impaired cerebral vasomotor reactivity in predicting ischemic cerebral events. Preventive vascular surgery might be considered in this high-risk subgroup of asymptomatic patients with severe carotid stenosis.     

Variation in HLA-DM expression influences conversion of MHC class II alpha beta:class II-associated invariant chain peptide complexes to mature peptide-bound class II alpha beta dimers in a normal B cell line

The maturation of invariant chain (Ii):MHC class II complexes into peptide-loaded alpha beta dimers occurs by proteolytic removal of Ii chain and binding of antigenic peptides derived from exogenous and endogenous Ags. A fragment of the Ii chain (class II-associated invariant chain peptide (CLIP) remains associated with class II alpha beta and is an intermediate in this process. Conversion of alpha beta:CLIP complexes into alpha beta:peptide complexes is facilitated by HLA-DM. Two unique mAbs, specific for I-Ab bound to human CLIP and I-Ab bound to DR alpha peptide, were used to assess the formation of these peptide:class II complexes in a human B lymphoblastoid cell line (B-LCL) (Swei) transfected with I-A(b). In multiple independent Swei:I-Ab transfectants, the amount of human CLIP (hCLIP):I-Ab expressed was inversely proportional to the amount of DR alpha 52-68:I-Ab; quantitative differences in HLA-DM expression accounted for this phenotype. In the low DM transfectant, a substantial proportion of I-Ab, but not DR molecules, was altered structurally and unable to present native protein Ags. Addition of DM transgenes to the DM-low cells resulted in an increase in DR alpha 52-68:I-Ab coupled with a decrease in hCLIP:I-Ab complexes and restoration of exogenous protein Ag presentation. The DR5 molecules in Swei cells, which have a lower affinity for hCLIP than I-Ab, were not affected by low DM expression, suggesting that the amount of DM required for conversion of CLIP:class II to peptide:class II may depend on the affinity of the class II molecules for CLIP or DM.     

Power spectral analysis of electroencephalographic desynchronization induced by cocaine in the rat

Whereas it is well-known that cocaine induces EEG desynchronization and behavioral excitation in animals and human subjects, the detailed effect of cocaine on EEG activity remains to be fully elucidated. This communication reports our attempts in quantifying the effect of cocaine on EEG signals recorded from the somatosensory cortex of adult male Sprague-Dawley rats under chloral hydrate anesthesia (400 mg/kg i.p.). Continuous, on-line and real-time power spectral analysis revealed that i.v. administration of two doses of cocaine (1.5 or 3.0 mg/kg) dose-dependently induced EEG desynchronization, as indicated by a decrease in the root mean square and an increase in the mean power frequency values. More interestingly, whereas both doses of cocaine promoted a reduction in the alpha (8-13 Hz), theta (4-8 Hz) and delta (1-4 Hz) spectral components, the beta band (13-32 Hz) underwent differential alterations. The lower dose of cocaine elicited a transient increase, followed by a decrease in the power of the beta band. A prolonged increase in the power of the beta band, on the other hand, was observed after the higher dose of cocaine. These results suggest that subtle changes in the individual EEG spectral components, which are dose-dependent, may underlie the EEG desynchronization induced by cocaine.     

DNA damage-induced by sodium flouride (NaF) and the effect of cholicalciferol

It is known that the high electronegativity of fluorine affects various soft tissues, especially the bone structure inorganisms. Of these tissues are the kidneys, which play an important role in the excretion of fluoride from the body.Fluoride affects many cellular mechanisms. One of these effects is DNA damage. Our study aimed to investigate thelikely protective effect of cholecalciferol (vitamin D3) on genomic DNA damage-induced NaF depending onconcentration and time. The IC25 and IC50 values of NaF for 3, 12 and 24 h and optimum dose of increase inproliferation to vitamin D₃ through MTT assay in NRK-52E kidney cells were determined. DNA damage wassignificantly increased (p < 0.05) compared to the control group in all groups except for vitamin D₃. It wasdetermined that treatment with NaF together with vitamin D₃ decreased the DNA damage compared to NaF treatedgroups for 3 and 12 h. NaF combined with vitamin D3 was determined statistically to decrease (p < 0.05) DNAdamage compared to NaF treated groups for 24 h. As a result, it was determined that the treatment with cytotoxicconcentration NaF depending on the time significantly increased (p < 0.05) the genomic DNA damage, but NaFtreatment together with vitamin D₃ decreased the DNA damage in renal cells depending on the time. It wasconcluded that vitamin D₃ may be useful in preventing DNA damage caused by NaF.     

尿素中添加腐植酸、黄腐酸、重过磷酸钙和氯化钾能抑制氨的挥发

该试验比较了不同混合物,尿素-重过磷酸钙-氯化钾、尿素-重过磷酸钙-氯化钾-腐植酸、尿素-重过磷酸钙-氯化钾-黄腐酸、尿素-重过磷酸钙-氯化钾-酸性混合物(黄腐酸+腐植酸)在对氨损失,土壤pH值,铵态氮和可利用硝态氮积累等方面的影响,以尿素单独施用作为对照。方法:在实验室条件下,利用一个封闭式动态空气流量系统来评估是否混有重过磷酸钙、氯化钾、腐植酸、黄腐酸的情况下尿素的有效性。氨损失、土壤pH值、土壤中铵态氮以及可利用硝态氮是由标准程序测定的。结果:与对照组(单独施用尿素)相比,处理尿素-重过磷酸钙-氯化钾,尿素-重过磷酸钙-氯化钾-腐植酸,尿素-重过磷酸钙-氯化钾-黄腐酸,尿素-重过磷酸钙-氯化钾-酸性混合物(黄腐酸+腐植酸)中氨损失明显地减少,减少率由12.92%、20.12%、25.94%达到100%,土壤中的铵态氮也有类似的变化。从所有的处理来看,只有尿素-重过磷酸钙-氯化钾-黄腐酸,尿素-重过磷酸钙-氯化钾-酸性混合物(腐植酸+黄腐酸)明显地积累了土壤中可利用硝态氮,这一结果与本研究中pH值的结果一致。结论:尿素、重过磷酸钙、氯化钾中混合腐植酸或者酸性的腐植酸和黄腐酸混合物能够显著减少氨损失。这项研究结果有助于提高尿素中N,P,K使用的有效性,同时减少环境污染。     

Multi-residue method for screening of pesticides in crops by liquid chromatography with tandem mass spectrometry

A simple and rapid method was developed for the screening of 82 pesticides/metabolites in a wide variety of crops, using solid-phase extraction and liquid chromatography with tandem mass spectrometry (LC/MS/MS). After extraction with methanol, the filtered extracts were made up to 100 mL and a 2 mL aliquot was subjected to solid-phase extraction. Co-extractives were removed with a C18 mini-column, while pesticides were retained on 3 kinds of mini-columns (HLB, SAX, activated carbon), and then eluted with acetonitrile. Analysis was performed by LC/MS/MS, and MS acquisition parameters were established in positive and negative ESI modes. The utility of the method was demonstrated by the analysis of 6 crops (carrot, cabbage, onion, spinach, lemon, brown rice) and one mixed vegetable juice. Of 82 compounds tested, 75 in carrot and 62 in lemon were obtained with recoveries ranging from 70-120%. For all samples tested, 75 compounds could be obtained with recoveries of over 50%, and the detection limits of most compounds were lower than 0.01 microg/g. This method provides acceptable performance for analysis of these 75 compounds. Further, by using aliquots of the extracts with small-scale mini-columns, purified samples could be obtained. This proposed method with small matrix effects, is effective and suitable for screening of multiple residual pesticides by using LC/MS/MS.