The Protective Effect of Dexanabinol (HU-211) on Nitric Oxide and Cysteine Protease-Mediated Neuronal Death in Focal Cerebral Ischemia

We hypothesized that dexanabinol can prevent neuronal death by protecting neuronal lysosomes from nitric oxide (NO)-mediated toxicity, and in turn, by suppressing the release of cathepsins during cerebral ischemia. Focal cerebral ischemia was induced in two sets of animals by permanent middle cerebral artery occlusion. The first set was used to monitor NO concentration and cathepsin activity, while the second was used for histological examination with hematoxylin and eosin, and TUNEL staining. In post-ischemic brain tissue, NO content and cathepsin B and L activity increased (p < 0.05). Dexanabinol treatment reduced NO concentration and cathepsin activity to the control level (p > 0.05). The number of eosinophilic and apoptotic neurons increased in the post-ischemic cerebral cortex (p < 0.05). However, dexanabinol treatment lowered both of these (p < 0.05). We conclude that dexanabinol might be a useful agent for the treatment of stroke patients.     

Effects of cathepsins B and L inhibition on postischemic protein alterations in the brain

The effects of selective inhibition of cathepsins B and L on postischemic protein alterations in the brain were investigated in a rat model of middle cerebral artery occlusion (MCAO). Cathepsin B activity increased predominantly in the subcortical region of the ischemic hemisphere where the levels of collapsing mediator response protein 2, heat shock cognate 70 kDa protein, 60 kDa heat shock protein, protein disulfide isomerase A3 and albumin, were found to be significantly elevated. Postischemic treatment with Cbz-Phe-Ser(OBzl)-CHN₂, cysteine protease inhibitor 1 (CP-1), reduced infarct volume, neurological deficits and cathepsin B activity as well as the amount of heat shock proteins and albumin found in the brain. Our data strongly suggests that the decrease in heat shock protein levels and the significant reduction of serum albumin leakage into the brain following acute treatment with CP-1 is indicative of less secondary ischemic damage, which ultimately, is related to less cerebral tissue loss and improved neurological recovery of the animals.     

Variation in dental occlusion and arches among melanesians of bougainville island,papua New Guinea. I. Methods,age changes,sex differences and population comparisons

Population studies of malocclusion lack comparability because of the subjective criteria employed in the definition of malocclusion. Alternatively, individual characteristics of occlusion can be quantified and compared within and between populations. Measurements were taken from the dental cases of 319 male an 359 female Melanesians from Bougainville, Papua New Guinea. The cross-sectional age changes from 12 to 68 years of age included an increase in intermolar arch width, a decrease in arch length and intercanine arch width, and increased crowding and malalignment. Neither age nor sex accounted for a large proportion of the differences among individuals. When compared to industrialized groups, the Bougainville population had a slight reduction in variance for most characteristics. Only the sagittal molar relationship was markedly less variable on Bougainville. The results emphasize that a quantitative evaluation of individual occlusal variables may reveal differences within and between populations not detected when simple malocclusion frequencies are reported.     

CTP regulates membrane-binding activity of the nucleoid occlusion protein Noc

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Overcoming the challenge of venous occlusion for lead implantation

Vein stenosis or occlusion is a frequent finding in patients with previously-implanted transvenous leads. This editorial describes the different techniques that may be used to overcome this hurdle in case a new lead needs to be implanted, and discusses two case reports in this issue of the journal.     

Sieve element occlusion provides resistance against Aphis gossypii in TGR-1551 melons

Feeding behavior and plant response to feeding were studied for the aphid Aphis gossypii Glover on susceptible and resistant melons(cv.Iroquois and TGR-1551,respectively).Average phloem phase bout duration on TGR-1551 was<7% of the duration on Iroquois.Sixty-seven percent of aphids on TGR-1551 never produced a phloem phase that attained ingestion(EPG waveform E2)in contrast to only 7% of aphids on Iroquois.Average bout duration of waveform E2(scored as zero if phloem phase did not attain E2)on TGR-1551 was<3% of the duration on Iroquois.Conversely,average bout duration of EPG waveform El(sieve element salivation)was 2.8 times greater on TGR-1551 than on Iroquois.In a second experiment,liquid nitrogen was used to rapidly cryofix leaves and aphids within a few minutes after the aphids penetrated a sieve element.Phloem near the penetration site was then examined by confocal laser scanning microscopy.Ninety-six percent of penetrated sieve elements were occluded by protein in TGR-1551 in contrast to only 28% in Iroquois.Usually in TGR-1551,occlusion was also observed in nearby nonpenetrated sieve elements.Next,a calcium channel blocker,trivalent lanthanum,was used to prevent phloem occlusion in TGR-1551,and A.gossypii feeding behavior and the plants phloem response were compared between lanthanum-treated and control TGR-1551.Lanthanum treatment eliminated the sieve element protein occlusion response and the aphids readily ingested phloem sap from treated plants.This study provides strong evidence that phloem occlusion is a mechanism for resistance against A.gossypii in TGR-1551.     

血流阻断的缺血预处理技术在肝癌切除术中的临床应用价值

目的:探讨血流阻断的缺血预处理技术在肝癌切除术中的临床应用价值。方法:选取2010年4月至2013年7月我院收治的96名原发性肝癌并采用肝脏部分切除术进行治疗的患者,将患者随机分为观察组和对照组,每组各48例,观察组在肝脏部分切除术阻断肝门血流前先分别给予1个5 min缺血和再灌注的处理。对照组不采取任何干预措施。术前、术后1天、3天、7天时分别进行生化检查,并于术前及术后1h对Fas-mRNA表达、Caspasc-3活性及AI进行测定,观察记录患者术后的并发症情况、手术时间、术中出血量以及住院时间。结果:术后1天、3天、7天时两组间的AST、ALT、TBIL等生化指标的含量情况相比,观察组均显著优于对照组(P0.05);术后l d,两组患者ALB均有不同程度的降低,对照组低于观察组(P0.05);术后住院时间观察组为13.28±3.85天,对照组为19.48±4.92天,观察组明显低于对照组(P0.05);术后1h,两组患者的Fas-mRNA表达、Caspasc-3活性相比于阻断前均显著提高,但观察组提高幅度明显低于对照组,差异有统计学意义(P0.05);两组阻断前均未见肝细胞凋亡,术后l h时,两组组均可见肝细胞凋亡,且对照组明显高于观察组组(P0.05)。结论:血流阻断的缺血预处理技术具有操作简便、副作用小的重要特点,应用于肝癌切除术中在保护肝功能方面具有显著的优势。     

In vivo THz imaging of human skin: Accounting for occlusion effects

In vivo terahertz (THz) imaging of human skin needs to be done in reflection geometry due to the high attenuation of THz light by water in the skin. To aid the measurement procedure, there is typically an imaging window onto which the patient places the area of interest. The window enables better pulse alignment and helps keep the patient correctly positioned during the measurement. In this paper, we demonstrate how the occlusion caused by the skin contact with the imaging window during the measurement affects the THz response. By studying both rapid point measurements and imaging over an area of a human volar forearm, we find that even 5 seconds of occlusion affects the THz response. As the occlusion time increases, the skin surface water content increases, resulting in the reduction of the amplitude of the reflected THz pulse, especially in the first 3 minutes. Furthermore, it was found that the refractive index of the volar forearm increased by 10% to 15% after 20 minutes of occlusion. In this work, we examine and propose a model for the occlusion effects due to the quartz window with a view to compensating for its influence.      

Vasculogenesis and angiogenesis: Extracellular matrix remodeling in coronary collateral arteries and the ischemic heart

Heart failure secondary to ischemic cardiomyopathy is the primary cause of cardiovascular mortality. The promise of the collateral circulation lies in its potential to alter the course of the natural history of coronary heart disease. The collateral circulation of the heart is responsible for supplying blood and oxygen to the myocardium at ischemic risk following severe stenosis and reduced vasoelasticity function of a major coronary artery. In response to flow, stress, and pressure, collateral vessels are restructured and remodeled. Vascular remodeling by its very nature implies synthesis and degradation of extracellular matrix components in the vessel wall. Under normal physiological conditions proteinases that break down the specialized matrix are tightly regulated by antiproteinases. The balance between proteinase and antiproteinase influences is discoordinated during collateral development which leads to adaptive changes in the structure, function, and regulation of extracellular matrix components in the vessel wall. The role of extracellular matrix components in coronary collateral vessel formation in a canine model of chronic coronary artery occlusion has been demonstrated. The role of matrix proteinases and antiproteinases in the collateral vessel play a significant role in the underlying mechanisms of collateral development. This review presents new and significant information regarding the role of extracellular matrix proteinases and antiproteinases in vascular remodeling, function, and collateral development. Such information will have a significant impact on the understanding of the basic biology of the vascular extracellular matrix turnover, remodeling, and function as well as on elucidating potential avenues for pharmacological approaches designed to increase collateral formation and optimize myocardial blood flow in the treatment of ischemic heart disease. J. Cell. Biochem. 65:388–394. © 1997 Wiley-Liss, Inc.     

Mitral/tufted cell activity is attenuated and becomes uncoupled from respiration following naris closure

Patterned neural activity helps to establish neuronal connectivity, produce coding of sensory information, and shape synaptic strengths. Here we demonstrate that normal olfactory bulb development might rely on spatial and temporal patterns of afferent neural activity. Neonatal naris occlusion profoundly impacts the development of the ipsilateral olfactory bulb, including reduced bulb volume, decreased protein synthesis, and increased cell death. Relatively few morphologic changes occur if closure is performed postweaning. We examined the immediate electrophysiological consequences of occlusion across this developmentally sensitive period by recording spontaneous and odor-driven mitral/tufted cell responses while the naris was open, closed, and then reopened. In 1-week-old animals, occlusion severely attenuated spontaneous activity, and presentation of the broad-spectrum odorant amyl acetate failed to evoke responses. In 2- and 4-week old rats, spontaneous activity was also reduced by naris closure. However, some cells remained responsive to concentrated odors, even in animals with transected anterior commissures, suggesting passage of odors across the septal window or retronasal pathways. In all age groups, cellular activity became uncoupled from the respiratory cycle. Approximately 47% (18 of 38) of the mitral/tufted cells exhibited activity that was correlated with respiration in the open-naris state, while only 5% (2 of 38) were coupled during naris closure. These data (a) indicate that naris closure reduces both spontaneous and odor-evoked responses, and (b) provide an electrophysiological correlate to a sensitive period in bulb development. The loss of respiration-related synchrony and the reduced activity of mitral/tufted cells may synergistically contribute to the divers consequences of naris closure on bulb development. © 1997 John Wiley & Sons, Inc. J Neurobiol 33: 374–386, 1997