Occluded Side Research Articles

Assessment of the Contribution of the External Carotid Artery to Brain Perfusion in Patients With Internal Carotid Artery Occlusion

The purpose of this study was to prospectively investigate the contribution of the ipsilateral external carotid artery (ECA) to cerebral perfusion in patients with internal carotid artery occlusion. Institutional Review Board approval and informed consent were obtained. Thirty functionally independent patients (24 men, 6 women; mean age, 63 years) with an angiographically proven unilateral internal carotid artery occlusion and transient or minor disabling ischemic attacks ipsilateral to the side of the internal carotid artery occlusion were included. Grading of ECA collateral flow was performed with intraarterial digital subtraction angiography. The contribution of the ECA to regional cerebral blood flow was assessed with selective arterial spin labeling MRI. Differences in regional cerebral blood flow were analyzed with Student t test. Twenty percent of the patients had ECA Grade 0 collateral flow (no filling of ophthalmic artery), 20% Grade 1 (filling of carotid siphon), and 60% Grade 2 (filling of anterior and/or middle cerebral artery) as demonstrated on digital subtraction angiography. Although in the Grade 1 group, the ECA supplied a smaller region of the brain compared with the Grade 2 group, the mean regional cerebral blood flow of the perfusion territory supplied by the ECA is similar (P=0.70) in the Grade 1 group (mean+/-SD 57+/-16 mL/min/100 g) and the Grade 2 group (60+/-12 mL/min/100g). In patients with symptomatic internal carotid artery occlusion, focal brain regions may strongly depend on the contribution to cerebral perfusion of the ECA ipsilateral to the side of the internal carotid artery occlusion, even in patients with limited ECA collateral supply as demonstrated on digital subtraction angiography.

Bilateral popliteal artery entrapment syndrome: case report

Popliteal artery entrapment syndrome occurs due to an extrinsic compression of the popliteal vessels that results in vascular damage. It is one of the most frequent causes of intermittent claudication in young patients. The authors describe a case of bilateral syndrome by anomalous position of the gastrocnemius muscle, with abnormal slip of its medial head (Rich's type III). During the operation the occluded right side was reconstructed by autologous saphenous vein bypass from femoral superficial to peroneal artery and on the left side the slip muscle was transected by posterior approach. Popliteal artery entrapment syndrome should be treated by surgery despite the degree of symptoms. Surgical treatment technique has released the vessel by extracting the muscle that caused entrapment, and reconstructing the narrow lumen bypass grafting.

Internal Carotid Artery Occlusion: Association With Atherosclerotic Disease in Other Arterial Beds and Vascular Risk Factors

The aim of this article is to investigate the association between internal carotid artery occlusion (ICAO) and the presence of atherosclerotic disease and vascular risk factors. The clinical characteristics and risk factors of 120 patients presenting with ICAO were retrospectively reviewed. All patients (n = 120) had at least 1 of the 4 vascular risk factor (diabetes, smoking, hypercholesterolemia, and hypertension); 2, 3, or all 4 risk factors were present in 14 to 82 of the patients (11.7% to 68.3%), 10 to 39 of the patients (8.3% to 32.5%), and 9 of the patients (7.5%), respectively. A total of 84 patients (70%) with ICAO had disease in at least 1 additional vascular bed (aorta, coronary or lower limb arteries). In addition to ICAO, vascular disease was present in 2 and all 3 of these arterial beds in 42 (35%) and 9 (7.5%) patients, respectively. Furthermore, stenosis or occlusion of the ipsilateral or contralateral vertebral arteries was recorded in 19 of 120 patients (15.8%). Regarding the contralateral carotid artery, 1 patient had bilateral ICAO. One patient had contralateral common carotid artery occlusion, and 1 patient was excluded from the analysis because of surgery to the contralateral carotid artery. Of the remaining 117 patients, 34 (29.0%) had less than 50% contralateral carotid artery stenosis. Thirty-two patients (27.4%) had 50% to 69%, and 51 (43.6%) had 70% to 99% stenosis. Ultrasonographic imaging of the carotid plaque of the contralateral carotid artery revealed that 52 of the 120 arteries (43.3%) were uniformly or predominantly echolucent (types I and II, respectively). Fifty-nine (49.2%) were predominantly or uniformly echogenic (types III and IV), and 9 (7.5%) could not be classified. A similar distribution of echomorphology was observed on the occluded side. ICAO is associated with widespread atherosclerotic disease and a high prevalence of vascular risk factors. Detection of ICAO should prompt the investigation of other arterial beds and treatment of risk factors.

Impact of unilateral hearing loss on sound localization

The impact of unilateral hearing loss on the localization of horizontal plane sound sources ipsilateral and contralateral to the side of the unimpaired ear was examined. Normal-hearing listeners judged the direction of six loudspeakers, separated by 30° and arrayed frontally or laterally on the right side with the right or left ear occluded. The benefit of massed practice over three sequential days was assessed. For the frontal loudspeaker array, azimuthal discrimination on the occluded side was poor but only 30% of sounds were perceived to come from the unoccluded side. For the right lateral array, when the ipsilateral ear was unoccluded, front and back were rarely confused. Accuracy mainly decreased for speakers close to the midline axis, front and back. When the contralateral ear was unoccluded responses were biased toward the rearmost speaker. Practice did not improve performance. The findings were discussed within the context of military operations. They support the need for job-specific hearing standards.

Dynamic susceptibility contrast perfusion magnetic resonance imaging in patients with symptomatic unilateral middle cerebral artery stenosis or occlusion

To evaluate cerebral hemodynamic disturbance in patients with symptomatic unilateral middle cerebral artery (MCA) high-grade stenosis or occlusion using dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC-pMRI). DSC-pMRI was performed in 28 patients with symptomatic unilateral MCA high-grade stenosis or occlusion. Hemodynamic parameters including relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), relative mean transit time (rMTT), and time to peak (TTP) were calculated and compared between the stenosed or occluded side and contralateral side. Seven of the 28 patients underwent surgery or interventional therapy, and hemodynamic changes between pre- and post-therapy were investigated. Prolonged rMTT and TTP were found in the stenosed or occluded MCA territories in all 28 patients. Significant differences were found in rCBV (P<0.05), rMTT (P<0.001), and TTP (P<0.001) between the stenosed or occluded side and the contralateral side. However, no significant difference was observed in rCBF (P>0.05). In the seven patients with surgical or interventional therapy, the values of rMTT and TTP significantly decreased after surgery or interventional therapy (P<0.001). DSC-pMRI may be a useful tool for evaluating and monitoring cerebral hemodynamic disturbance in patients with symptomatic unilateral MCA high-grade stenosis or occlusion.

Triptolide for cerebral ischemia/reperfusion injury*

Background Studies have demonstrated that triptolide has good anti-inflammatory and immunosuppressive effects. However, the effect of triptolide on cerebral ischemia/reperfusion injury is still unclear. Objective To observe the effects of triptolide on neurologic function, infarct volume, water content of brain tissue, neutrophil number in microvascular wall and interleukin-1β(IL-1β) expression in rat models of local ischemia/reperfusion, and analyze the mechanism of triptolide for protecting brain. Design Randomized controlled experiment. Setting Department of Pathology, Medical School of Ningbo University; Department of Forensic Medicine, Tongji Medical College of Huazhong University of Science and Technology. Materials Sixty Wistar rats of either gender, aged 4 months old, weighing from 200 to 250 g, were provided by the Experimental Animal Center, Tongji Medical College, Huazhong University of Science and Technology. Triptolide was purchased from Fujian Institute for Medical Science (purity 99.98%; Batch No. 2000215). It was dissolved in 20 g/L propanediol, and filtered with 200-mesh filter for later use. Methods This experiment was carried out in the laboratory of Forensic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Department of Pathology, Medical School of Ningbo University between January 2001 and September 2004. ▪ Sixty Wistar rats were randomized into 4 groups: sham-operation group, model group, low-dose triptolide group and high-dose triptolide group. Rats in each group, except for sham-operation group, were developed into rat models of cerebral ischemia/reperfusion according to the method of Longa et al. In the first 3 days of modeling, rats in the low- and high-dose triptolide groups were intraperitoneally injected with 0.2 and 0.4 mg/kg triptolide respectively, once a day, 3 days in total. ▪ At ischemia 1 hour and reperfusion 24 hours, infarct volume, neurologic deficit (five-point scale, higher scores indicated poor neurologic function), water content of brain tissue, neutrophil number in microvascular wall in the middle cerebral artery occlusive side of rats were detected, meanwhile, brain tissue injury degree and IL-1βimmunohistochemical staining changes in brain-derived nerve cells were observed under the optical microscope. Main outcome measures Neurologic deficit, infarct volume percentage, water content of brain tissue, neutrophil number in microvascular wall and positive rate of IL-1β immunoreaction. Results Sixty rats were all involved in the final analysis. ▪ Neurologic deficit scores of rats in the low- and high-dose triptolide groups were (1.96±0.14) and (1.75±0.16)points respectively, which were both significantly lower than those in model group [(2.58±0.11)points, P < 0.05,0.01]. ▪ Infarct volume percentages of rats in low- and high-dose triptolide groups were significantly lower than that in model group separately ( P < 0.05, 0.01). ▪Water content of brain tissue of rats in model group was significantly higher than that in the sham-operation group [(82.35±1.26)% vs. (76.65±1.17)%, P < 0.01]; Water content of brain tissue of rats in the low- and high-dose triptolide groups was respectively(80.15±1.43)%,(78.23± 1.15)%, which was significantly lower than that in the model group ( P < 0.05, 0.01). ▪Pathological changes of brain tissue of rats: Under the optical microscope, infarct focus was not found in the brain tissue of rats in the sham-operation group, while clear infarct focus could be found in the brain tissue of rats in the model group; Although infarct focus was found in the brain tissue of rats in the low- and high-dose triptolide groups, the whole infarct area was contracted as compared as that in the model group. ▪Neutrophil number in microvascular wall of brain tissue of rats in the low- and high dose triptolide groups was 10.60±2.12,8.11±1.21 respectively, which was significantly less than that in model group(16.25±1.96, P < 0.05,0.01). ▪Positive rate of IL-1βimmunoreaction in the brain tissue of rats in model group was significantly higher than that in the sham-operation group ( P < 0.01); and positive rate of IL-1β immunoreaction in the brain tissue of rats in low- and high-dose triptolide groups was significantly lower than that in the model group ( P < 0.05, 0.01), but higher than that in the sham-operation group, without significant difference ( P > 0.05). Conclusion Triptolide protects against cerebral ischemia/reperfusion injury of rats that may be related with anti-inflammations. Triptolide inhibits IL-1β expression in brain tissue and reduces the attachment and aggregation of neutrophils in blood capillary, and further inhibits the infiltration of blood white cells, thus, it will lessen cerebral injury, contract cerebral infarct and improve cerebral function.

Symptomatic Carotid Artery Occlusion: Flow Territories of Major Brain-Feeding Arteries

To prospectively investigate the extent of flow territories of the contralateral internal carotid artery (ICA) and vertebrobasilar arteries in patients with symptomatic ICA occlusion. Ethics committee approval and informed consent were obtained. Flow territory mapping of the ICA contralateral to the occluded ICA and mapping of the vertebrobasilar arteries were performed by using selective arterial spin-labeling magnetic resonance imaging in 23 functionally independent patients (22 men, one woman; mean age, 58 years +/- 8 [standard deviation]) with symptomatic ICA occlusion. The control group consisted of 68 subjects (57 men, 11 women; mean age, 59 years +/- 9) without hemodynamically significant ICA obstruction. Voxel-based chi(2) testing with Bonferroni correction was performed to analyze significant differences in the extent of the flow territories. Flow territory maps in patients with symptomatic ICA occlusion showed significant differences in the flow territories of the contralateral ICA and vertebrobasilar arteries compared with those in control subjects (P < .05). In functionally independent patients with symptomatic ICA occlusion, the middle cerebral artery flow territory ipsilateral to the occluded ICA is mainly supplied by the vertebrobasilar arteries, whereas the anterior cerebral artery flow territory on the occluded side is mainly supplied by the contralateral ICA.

Perfusion MRI before and after acetazolamide administration for assessment of cerebrovascular reserve capacity in patients with symptomatic internal carotid artery (ICA) occlusion: comparison with 99mTc-ECD SPECT

Impaired cerebral vascular reserve (CVR) in patients with symptomatic internal carotid artery (ICA) occlusion is regarded as a possible indication for performing extra-/intracranial (EC/IC) bypass surgery. As perfusion MR imaging (MRI) can demonstrate cerebral haemodynamics at capillary level, our hypothesis was that perfusion MRI could be used in these patients for the evaluation of CVR following acetazolamide challenge in a similar way to single photon emission CT (SPECT) and might provide additional information. Enrolled in the study were 12 patients (mean age 61.3 years; 11 male, 1 female) with symptomatic unilateral ICA occlusion proven by angiography. Both perfusion MRI and 99m-technetium-ethyl-cysteinate dimer ((99m)Tc-ECD) SPECT were performed before and after injection of acetazolamide (Diamox ,1000 mg i.v.). CVR parameters including regional cerebral blood flow (rCBF) and volume (rCBV), and mean transit times (MTT) were measured by perfusion MRI. The patients with impaired CVR proven by SPECT (n = 9) had a negative mean rCBF increment (-46.52%), negative rCBV increment (-13.5%) and delayed MTT (mean +2.98 s), respectively, on the occluded side (Student's t-test all P < 0.05). The patients with sufficient CVR (n = 3) had a mean rCBF increment of 1.2%, a decrement of rCBV of 10.46%, and a mean MTT shortening of 0.27 s following the acetazolamide injection. Perfusion MRI before and after acetazolamide administration compares favourably with (99m)Tc-ECD SPECT for the detection of impaired CVR. The impact that perfusion MRI studies (before and after acetazolamide administration) might have on the treatment decision in patients with ICA occlusion has yet to be determined by a prospective study.

Tratamento da síndrome da apnéia e hipopnéia obstrutiva do sono com aparelhos intrabucais

A síndrome da apnéia e hipopnéia obstrutiva do sono (SAHOS) é um distúrbio que atinge cerca de 4% da população adulta e que, além dos problemas sociais associados ao ronco e à sonolência diurna excessiva, é preocupante pelos quadros de hipertensão pulmonar e insuficiência cardíaca que pode desencadear. REVISÃO E DISCUSÃO: Através de uma revisão de literatura discutiu-se o uso de aparelhos intrabucais para o tratamento dessa patologia, destacando-se a eficácia e as limitações dessa terapia, os principais sintomas clínicos, os principais efeitos colaterais oclusais, o grau de colaboração e o índice de satisfação dos pacientes. CONCLUSÕES: Concluiu-se que a terapia com aparelhos intrabucais deve ser a de primeira escolha para o tratamento de SAHOS de média a moderada, sendo o desconforto dentário, articular e muscular, a hipersalivação e a xerostomia os sintomas clínicos mais freqüentes, com efeitos colaterais oclusais leves que normalmente não geram incômodos aos pacientes, com bom grau de colaboração e alto índice de satisfação.

Histological changes in rat nasal epithelia after unilateral neonatal naris occlusion

The authors studied the extent of the different epithelia lining the nasal fossae of the albino rat after neonatal closure of one naris. Newborn pups were anesthetized by hypothermia and the external opening of their right naris cauterized, while littermates served as controls. Animals were sacrificed at 3 months, and the occluded (OCF) and nonoccluded (NOF) fossae of experimental animals as well as both fossae of control animals (CTF) were histologically studied. In both control and experimental animals, nasal fossae were lined by five different types of epithelia: squamous stratified, transitional, metaplastic, respiratory, and olfactory epithelia. It was found that closure of one naris provokes reorganization of the epithelial lining in both the occluded and nonoccluded side. In CTF airflow, physical conditions as well as pollutants and biological agents irritate the epithelial lining, causing squamous metaplasia as well as metaplastic epithelium showing inflammation in rostral levels. In CTF caudal levels, the metaplastic epithelium appears to a lesser degree and the respiratory epithelium prevails, except for the most caudal level where the olfactory epithelium is prevalent. In OCF, the protected environment created prevents the occurrence of metaplastic epithelium, the transitional, respiratory, and olfactory epithelia developing in the corresponding area instead. In NOF, where the airflow is double, the same pattern occurs as in CTF, although metaplastic epithelium values are approximately double, suggesting a clear linear effect. An outstanding feature observed was the increased extent of the olfactory epithelium in OCF regarding NOF, although changes in its morphological structure were not found. Airflow properties, including pressure, coldness, velocity, and turbulence, as well as biological and chemical hazards present in inflow, cause histological reorganization of the nasal epithelium lining during postnatal development. Results prove the need to consider airflow changes in nasal fossae surgery and point to the protective value of naris closure in ENT clinics, supporting it as a treatment of atrophic rhinitis.

Naris occlusion alters transductory protein immunoreactivity in olfactory epithelium.

We have recently shown that unilateral naris occlusion (UNO) causes an increase in olfactory marker protein (OMP) immunoreactivity (IR) in mouse olfactory sensory neurons (OSN) from the occluded side of the nasal cavity and a decrease in OMP-IR on the non-occluded side, relative to controls. Given OMP's demonstrated role in olfactory modulation, these OMP-IR changes have been interpreted as a compensatory response by OSNs to odor deprivation on the occluded side and to supernormal exposure to odor on the non-occluded side of the nasal cavity. In the current study, we examined the developmental timing and the regional distribution of this process throughout the nasal cavity using immunocytochemistry. Results demonstrate that OMP-IR diverges in OSNs from the occluded side relative to the non-occluded side of the nasal cavity within eleven days after UNO, with statistically significant differences measurable after 17 days (n=16). We also measured relative levels of the Type 4 phosphodiesterase (PDE4A), another potential olfactory modulator, in nasal cavity tissue from UNO (n=8) and untreated mice (n=9) using western blots and immunocytochemistry. Like OMP, PDE4A-IR increased on the occluded side of the nasal cavity after UNO. Finally, we used immunocytochemistry to assess relative levels of olfactory-specific adenylyl cyclase (ACIII, n=4) and G-protein (Golf, n=2) in OSNs from the occluded and non-occluded sides of the nasal cavity of UNO mice. Following UNO, ACIII but not Golf -IR levels diverged comparing the occluded to the non-occluded sides of the nasal cavity. Taken together, our findings provide support for the previously unknown phenomenon of compensatory responses by OSNs to odor environment.

Long term follow-up of unilateral occlusion of the internal carotid artery including repeated tests of vasomotor reactivity by transcranial Doppler

Background: Early study on pathological flow pattern in the ophthalmic artery (OA), connected with impaired vasomotor reactivity (VMR) and low pulsatility index (PI) in the anterior cerebral artery (ACA) on the occluded side, suggested collateral exhaustion. We undertook this study to evaluate whether the occurence of new strokes is predicted by special haemodynamic features.Method: A total of 27 patients (22 men and five women), aged 63 ± 15 years (mean ± SD) with longstanding occlusion of the internal carotid artery (ICA), confirmed by duplex scanning were studied. They had minimal neurological deficit and were followed-up for mean 4.3 ± 1.8 (mean ± SD) years by repeated clinical and 3-D transcranial Doppler (3-D TCD) examinations with azetazolamide test of vasomotor reactivity (VMR).Results: During follow-up, seven patients had new strokes (five minor strokes and two major ones), two ipsilateral and four contralateral to the ICA occlusion and one in the posterior circulation. Four patients died, All patients experiencing a new stroke had previous symptoms and pathological flow patterns in the OA, i.e retrograde or isoelectric flow were noted in six of them. One patient with contralateral stroke experienced occlusion of the ICA located above the origin of the OA with anterograde flow; otherwise none of 11 patients with anterograde flow had a new stroke (p<0.05, Fisher exact text). During the follow-up, the initial mean velocity (MV) in the middle cerebral artery (MCA) on the occluded side in six patients with a new stroke in the anterior circulation, was 26.83 ± 10.50 cm/s, which was significantly different from that of patients without a new stroke (45.80 ± 12.8 cm/s) (p<0.01). MV in the ICA on the non-occluded side at the last examination was greater than that at the first examination (p<0.05) and increased after the use of acetazolamide only on this side (p<0.05), while PI decreased bilateraly (p<0.001 and 0.05). Resting MV both in the MCA on the occluded and ACA on the non-occluded side slightly decreased, while MV in the posterior cerebral artery (PCA) increased on the occluded side (p<0.083) compared with that at the start of the follow-up. VMR in the ACA decreased slightly both on the non-occluded and occluded side (Δ-6.9 and Δ-5.3 respectively), while impaired VMR ≤ 11% was not significantly connected with new strokes.Conclusion: During the follow up, new strokes had appeared on both sides and in vertebrobasilar territory and were connected with pathological flow pattern in the OA and low MV in the MCA at the first examination.

Cerebral Blood Flow Change before and after Carotid Angioplasty and Stenting (CAS) in Cases with Contralateral Carotid Artery Occlusion

Contralateral carotid artery occlusion is thought to represent a significant risk factor in carotid endarterectomy (CEA). There is also evidence that intraoperative and postoperative hypotention may cause contralateral hemodynamic ischemia. As such, contralateral carotid artery occlusion is regarded as a risk factor for carotid angioplasty and stenting (CAS). In this paper, we report on five cases of severe ICA stenosis with contralateral carotid artery occlusions. Cerebral blood flow(CBF) and cerebral vasoreactivity( CVR) of the contralateral carotid artery occlusions were measured before and after CAS. Additionally, the influence that ipsilateral CAS exerted on the occluded side was examined. (123)I-IMP SPECT was performed before and after CAS, both at rest and at the time of acetazoramide administration. The CBF was evaluated quantitatively using the ARG method. The mean CBF of the treated side rose from 30.0 +/- 7.1 ml/100g/min to 34.4 +/- 8.3 ml/100g/min (p < 0.05), and the mean CBF of the occluded side similarly rose from 28.3 +/- 6.1 ml/100g/min to 31.7 +/- 6.4 ml/100g/min (p < 0.05). Correspondingly, the regional CVR (rCVR) increased from 5.9% +/- 16.3% to 35.0% +/- 16.4%(p < 0.05) on the treated side, and from 3.7% +/- 14.7% to 10.7% +/- 16.9% (p < 0.05) on the occluded side. This demonstrates that ipsilateral CAS seems to improve both CBF and CVR on the contralateral occluded side. The fact that some cases developed cross flow from the anterior communicating artery was both remarkable and significant. Where there was poor cross flow from the anterior communicating artery, improvement in cerebral vaso reactivity was limited.

The expression of aquaporin-4 in the ischemic penumbra tissues after acute cerebral ischemia in rats

Objective The aim of this study was to investigate the aquaporin-4(AQP4) expression in the ischemic penumbra tissues.Methods Thirty-six Wistar rats were divided into 7 groups randomly, including control group(n=6) and occluded groups(n=30). The occluded groups were studied after the right middle cerebral artery of the rats unilaterally occluded(MCAO) at an interval of 15 min, 30 min, 1 h, 3 h, 6 h and 24 h, respectively(n=5 for each group). The operation process of the control group was the same as the occluded group except occluded MCAO. Then all rats were imaged with T_1WI, T_2WI and diffusion weighted-imaging(DWI). The brain tissue, according to the method by LIU Meili reported, was regarded as the area of the graphic penumbra. The relative apparent diffusion coefficient of the graphic-penumbra (rADC_1) and the center infarction(rADC_2)(ratios between the values of the occluded side and the opposite side) were calculated. The animals were sacrificed and perfused with the mixture solution consisting of TTC at different time intervals. The graphic-penumbra of the biggest layer of the ischemic cerebral tissue which corresponded to the DWI was examined with immunohistochemistry and RT-PCR. Meanwhile, histologic examination was performed at same site of the lesion. Results There were no significant changes on MRI, the relative apparent diffusion coefficient and the expression of the AQP4. The abnormal high intensity was found on DWI at 15 min after MCAO. T_2WI detected the lesion at 1 h after MCAO. The value of the rADC_1 decreased within 24 h after MCAO in ischemic penumbra, especially, it descended quickly within 1 h after MCAO, from(70.4±6.9)% at 15 min to(53.5±10.9)% at 1 h. Whereas, in the infarct tissue, the changes of the rADC_2 had a rule of decrease from(71.5±6.6)% at 15 min to(45.7±10.5)% at 3 h at first time, and then follow an increasing up to(78.7±11.5)% at 24 h after MCAO. The expression of AQP4 increased gradually within 24 h after MCAO, from 0.42±0.05 at 15 min to 1.18±0.12 at 24 h, it showed negative relationship with the rADC_1 in the ischemic penumbra (r= -0.966,P0.001), where the major pathologic changes were intracellular edema. Conclusion The results imply that the intracellular edema is one of the important pathologic characteristics of the ischemic penumbra. The high expression of AQP4 may play a key role in the ischemic penumbra. The decreasing of rADC values in the ischemic penumbra maybe provide earlier and more precise evaluation of the level of the AQP4 expression.

Effects of light stimulation of embryos on the use of position-specific and object-specific cues in binocular and monocular domestic chicks ( Gallus gallus)

Chicks hatched from eggs incubated in the dark (D-chicks) or from eggs exposed to light during the last 3 days before hatching (L-chicks) were trained on day 4 to peck at small cones for food reinforcement. The cones had different patterns (checked or striped) and were located in different positions (either on the left or on the right of a rectangular arena) so as both object-specific (pattern) and position-specific cues could be used to discriminate cones that contained or that did not contain food. After learning, the position of the cones was reversed so that object- and position-specific cues provided contradictory information. No effect of light incubation was observed in binocular chicks that chose cones on the basis of object-specific cues. Monocular D-chicks also tended to approach and peck the cones with the correct pattern in the wrong position, whereas monocular L-chicks did not show any clear choice. Initial choices for one side or other of the arena were mostly determined by the first side visible through the non-occluded eye in D-chicks, particularly when using their left eye. These results suggest that light exposure of the embryo makes neural mechanisms that do not receive direct visual input (i.e., those of the occluded side) more available to be used in assessment of novelty.

The magnetic resonance Matas test: Feasibility and comparison with the conventional intraarterial balloon test occlusion with SPECT perfusion imaging

To evaluate a new MR Matas test that uses a form of contrast-enhanced MR angiography (MRA) with temporary manual occlusion of the common carotid artery whose internal carotid artery (ICA) is to be permanently sacrificed. The MR Matas test was performed on eight patients using an open type MR imager (Signa Profile 0.2 Tesla ver. 7.5, GE-YMS, Tokyo, Japan). Conventional balloon occlusion Matas test and single-photon emission computed tomography (SPECT) of the brain were performed in all cases within a week before or after the MR Matas test. The MR Matas test was successful in all eight patients without any complications. The image quality of the MR Matas test was generally sufficient to confirm cross-flow from the patent side to the occluded side in comparison with selective intraarterial digital subtraction angiography (IADSA) except in one case. Brain perfusion information using MR Matas test is comparable to brain SPECT.

Naris occlusion alters olfactory marker protein immunoreactivity in olfactory epithelium

Though its function remains obscure, olfactory marker protein (OMP) has been implicated in olfactory transduction and the enhancement of neurogenesis within olfactory epithelium. Here we show, using Western blot analysis and immunocytochemistry, that unilateral naris occlusion (UNO) on postnatal day 1 alters OMP immunoreactivity (IR) differentially on the occluded and non-occluded sides of the nasal cavity in 18, 24 and 70-day-old mice. Compared to untreated animals, UNO-treated animals had a decrease in OMP-IR in olfactory receptor neurons on the non-occluded side and an increase in OMP-IR in olfactory receptor neurons on the occluded side of the nasal cavity. These results suggest that OMP concentration is up- or down-regulated depending on the amount of odor stimulation olfactory receptor neurons receive. It is proposed that this apparent change in protein concentration may be part of a more general compensatory response by olfactory neurons to levels of odor in the environment.

Neuromagnetic measurement of unilateral temporo-parietal theta rhythm in patients with internal carotid artery occlusive disease

Rhythmic theta activity detected by electroencephalography (EEG) may be correlated with cerebrovascular brain diseases. Magnetoencephalography (MEG) has higher sensitivity and spatial resolution than conventional scalp EEG, so may be a better method to detect theta rhythm in patients with internal carotid artery (ICA) occlusive disease. Simultaneous EEG and MEG were performed in the awake state in 48 patients with unilateral ( n = 42) or bilateral ( n = 6) stenotic lesions (more than 60% occlusion) of the ICA ( n = 47) or middle cerebral artery ( n = 7), and in 27 age-matched healthy normal subjects. No subject had severe neurological deficits. MEG detected the theta rhythm (6–8 Hz) in 14 of 48 patients: ipsilateral to the stenotic or occluded side in 13 hemispheres and bilaterally in one patient with unilateral lesion. The source of the MEG theta rhythm was estimated in the dorsolateral temporo-parietal area, regardless of the location of infarct foci or the stenotic portion of the ICA system. The temporo-parietal theta rhythm was separated from the occipital alpha rhythm by frequency and distribution in MEG. The theta rhythm was found in only two patients by EEG, as well as by MEG. MEG provided better separation of this theta rhythm from the occipital alpha rhythm. Neither MEG nor EEG detected this theta rhythm in the normal subjects. Unilateral temporo-parietal theta rhythm is correlated with the hemisphere with ICA occlusive disease. This rhythm may indicate mild or subclinical abnormalities in the ICA system. MEG is superior to EEG for the detection and localization of theta rhythm.

The expression of PPTA and c-fos mRNA in dog caudal spinal trigeminal nucleus induced by traumatic occlusion

PPTA and c-fos mRNA expression were detected in dog caudalis subnucleus of trigeminal spinal tract nucleus (VC) induced by trauma occlusion in order to investigate orofacial pain mechanism. The occlusal surface of the first and second maxillary right molars in 15 dogs were unilaterally raised 1.5 mm with casting Ni-Cr inlay which were fixed in Class I hole. On days 3, 7, 14, 30 and 60 after teeth operation, the VC of right and left sides were removed. PPTA and c-fos mRNAs were detected in experimental and control groups with reverse transcription-polymerase chain reaction (RT-PCR). (1) The basal levels of PPTA and c-fos mRNAs were extremely low and poorly detectable in VC in control animals. (2) The expression of PPTA mRNA in VC of traumatic side was up regulated from 3 days after inlay was fixed in molar and reached peak level during 14 to 30 days and then down-regulated gradually and no significant difference was noted between 60 days group and control group. (3) c-fos mRNA expression was more intense during 3 to 7 days compared with the control group but undetectable in the other experimental period. (4) Both PPTA and c-fos mRNAs expression in VC of trauma occlusal side were more intense than that in the contralateral side. The present results show that both PPTA and c-fos mRNA expression are elevated in dog's VC induced by traumatic occlusion. The primary afferent terminal of orofacial area is sensitized, which suggest one kind of mechanism of orofacial pain in the condition of traumatic occlusion.

Transient focal ischemia affects the cAMP second messenger system and coupled dopamine D1 and 5-HT1A receptors in the living monkey brain: a positron emission tomography study using microdialysis.

Using positron emission tomography (PET) and microdialysis, the present study showed that neuronal damages after transient focal ischemia was partly induced by hyperactivation of the cyclic adenosine 3',5'-monophosphate (cAMP) second messenger system through modulations of dopamine D, and serotonin 5-HT1A receptors in the living brains of cynomolgus monkeys. Occlusion of the right middle cerebral artery for 3 hours suppressed CBF in the striatum, and reperfusion induced hyperperfusion in the neocortex and striatum of the occluded side. Six hours after reperfusion, the activity of the cAMP second messenger system assayed with [11C]rolipram was significantly facilitated in the neocortex and striatum where CBF was lowered more than 40% of normal during occlusion ("ischemic" area). Seven days later, impaired dopamine D1 and 5-HT1A receptor binding, measured with [11C]SCH23390 and [carbonyl-11C]WAY-100635, respectively, was observed in the ischemic area. Microdialysis analysis revealed that the striatal dopamine level provided a transient and marked increased during occlusion and after reperfusion, whereas the cortical serotonin level transiently increased only after reperfusion, and was at an undetectable level thereafter. Administration of rolipram (0.1 and 1 mg/kg, intravenously) during occlusion facilitated reduction of dopamine D1 binding, whereas rolipram administration 6 hours after reperfusion induced a further decrease in 5-HT1A receptor binding. These results suggest that the activation of cAMP second messenger system modulated by dopamine D1 and 5-HT1A receptors could be involved in the neuronal degeneration after transient cerebral ischemic insult.