bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebral vasomotor reactivity in normotensive and spontaneously hypertensive rats.
Authors: Johansson B B , Nilsson B
Published: June 2011

Intravenously injected metaraminol induced a larger blood pressure increase in spontaneously hypertensive rats (SHR) than in normotensive controls (NR) when the pressure was raised from the same starting level. Cerebral blood flow (CBF) response in NR was either perfect autoregulation, partial autoregulation or "break-through." When present, the autoregulatory response was very rapid, i.e. the flow returned to the initial value within 10-15 sec. All SHR showed an initial prompt vasoconstrictor response which was followed after 30-40 sec by a gradual flow increase. The blood pressure elevation was highest in SHR when hypertension was induced by compression of the aorta, which supports the hypothesis that the enhanced response is, at least in part, a consequence of an increased vessel wall to lumen ratio. The characteristic CBF pattern observed in SHR after a metaraminol-induced rise in blood pressure was not seen when the blood pressure was increased by aortic compression, which suggests an effect of the drug separate from its pressor effect. During maximum vasodilatation the cerebrovascular resistance (CVR) was considerably higher in SHR than in NR. Assuming an equivalent vessel density in the 2 groups, our results suggest that structural changes in resistance vessels in SHR encroach on the lumen.
Influence of various agents on the development of brain edema in the rat following microembolism. Protective effect of gamma-butyrolactone.
Authors: Bralet J , Beley P , Bralet A M , Beley A
Published: June 2011

Brain edema was induced in rats by injecting 50 mu microspheres, labelled with 85Sr, into the internal carotid artery. The use of radioactive microspheres as embolic agents enabled the number of microspheres to be determined in each cerebral hemisphere. Edema was assessed 12 or 24 h after embolization by measuring brain water content and, in some experiments, sodium and potassium. Pretreatments with dexamethasone, parachlorophenylalanine (an inhibitor of 5-hydroxytryptamine synthesis), mepyramine and metiamide (H1 and H2 histamine receptor antagonists) or aminophylline did not influence significantly the development of brain edema evaluated 24 h after embolization. Aminophylline treatment (100 mg/kg) markedly increased mortality following embolization. Gamma-butyrolactone (300 mg/kg, every 2 h) inhibited significantly the development of brain edema evaluated 12 hours after embolization. Increases in water and sodium in the embolized cerebral hemisphere were reduced by about 50%. This protective effect may be related to the known depressant action on brain metabolism.
Changing pattern of cerebral infarction: 1945--1974.
Authors: Garraway W M , Whisnant J P , Kurland L T , O'Fallon W M
Published: June 2011

This study has identified all persons in the population of Rochester, Minnesota, who had a diagnosis of cerebral infarction during the period Jan. 1, 1970, through Dec. 31, 1974, and has confirmed the continuing decline in the incidence rate previously reported. The decline in the rate has been accelerating, with a relatively greater reduction occurring in women and in the more elderly age groups. There has been a decline in the prevalence rate in women which was not seen in men. The over-all impact of cerebral infarction was to reduce the proportion of those persons who were completely independent from 57% before cerebral infarction to 16% after infarction. Comparison of survival among patients with cerebral infarction occurring in the two quinquennia 1945--49 and 1970--74 showed only a 2% increased probability of survival at 30 days; the difference in survival increased progressively to 16% at 5 years. The reason for the declining incidence and increased survival in cerebral infarction in this population has not been established, but evidence of increased community surveillance and treatment of hypertension among persons before the onset of cerebral infarction is presented.
Histopathological reactivity of carotid arteries of normotensive Sprague-Dawley vs spontaneously hypertensive rats to ligation injury.
Authors: Wexler B C
Published: June 2011

The common carotid arteries of normotensive non-arteriosclerotic Sprague-Dawley (S-D) rats, mildly hypertensive but arteriosclerotic breeder S-D rats, severely hypertensive but non-arteriosclerotic virgin spontaneously hypertensive rats (SHR), and severely hypertensive breeder SHR were ligated to induce injury. Three weeks post-ligation, the animals were killed and histopathological sections of the ligated artery demonstrated myointimal proliferation without occlusion in the normotensive S-D rats but myointimal proliferation with occlusion in the severely hypertensive SHR. Breeder S-D rats with moderate hypertension manifested a high incidence of total occlusion by combined myointimal proliferation and thrombosis. Severely hypertensive breeder SHR manifested a high incidence of massive thrombi containing cholesterol clefts causing total occlusion of the injured artery. It is suggested that the severity of the hypertension and the hormonal-metabolic milieu conditions the morphologic response of the arterial wall to injury.
Low molecular weight dextran in experimental embolectomy.
Authors: Laha R K , Israeli J , Dujovny M , Barrionuevo P J , Hellstrom H R
Published: June 2011

The canine middle cerebral artery (MCA) was embolized with a pliable cylinder 8 mm long by 1.6 mm in diameter via the internal carotid artery. Both control and experimental embolectomies were performed 6 hours following embolization. The experimental animals were treated with low molecular weight dextran (LMD). In the control animals, the average volume of infarction in the brain was 1.45 cm.3 In the experimental animals the average volume of infarction was 0.13 cm.3
Comparative effects of unilateral and bilateral carotid artery ligation in the spontaneously hypertensive rat.
Authors: Wexler B C
Published: June 2011

Male and female, spontaneously hypertensive rats (SHR) with blood pressures ranging from 190-210 mmHg were subjected unilateral or bilateral carotid artery ligation. Representative numbers of animals were killed 2, 4, 6, 8, 10, 12, 24 and 48 hours later. Severe cerebral ischemia caused a significant and protracted increase in the pre-existent high blood pressure, the enzymes CPK, SGOT and LDH triglycerides, free fatty acids, glucose, and corticosterone. Despite these marked pathophysiologic changes, the brains of these animals were free of real damage except for cerebral edema and scattered petechiae. Some of the animals developed massive atrial thrombi and myocardial infarcts. It is suggested that severe cerebral ischemia precipitated the myocardial infarcts through the aegis of the hypothalamic-pituitary-adrenal stress response.
Arterial occlusion following anastomosis of the superficial temporal artery to middle cerebral artery.
Authors: Furlan A J , Little J R , Dohn D F
Published: June 2011

Symptoms of cerebral ischemia following superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis are uncommon and are usually related to impaired flow through the anastomosis or occlusion of the cortical receptor artery. In this report, 3 patients are described who developed symptoms of cerebral ischemia after surgery despite a widely patent anastomosis. In each patient, postoperative angiography revealed occlusion of a previously demonstrated high-grade stenosis of the intracranial internal carotid artery (ICA) or MCA. Occlusion of the stenotic artery was probably related to decreased velocity of blood flow through the narrowed vessel resulting from alterations in flow patterns following anastomosis.
Amelioration of cerebral ischemia by prior treatment of hypertension.
Authors: Halsey J H , O'Brien M , Strong E R
Published: June 2011

Bilateral carotid artery ligation was made in 14 SHR while rCBF was serially measured with hydrogen clearance. Blood pressure was controlled with an intra-arterial catheter connected to a reservoir. There was no significant correlation between blood pressure and rCBF prior to the carotid occlusion, but afterwards there was a progressively increasingly negative correlation between mean arterial blood pressure and rCBF with time. These observations indicate that the severity of ischemia is greater in the presence of hypertension if the hypertension is present prior to the onset of ischemia and the blood pressure maintained constant thereafter.
Angiographic appearance of carotid occlusion in acute stroke.
Authors: Pessin M S , Duncan G W , Davis K R , Hinton R C , Roberson G H , Mohr J P
Published: June 2011

The angiographic appearance of the proximal end of internal carotid artery occlusion is reported in 41 patients with acute stroke in the areas of the brain supplied by the carotid artery. All patients had angiography within 6 days of stroke onset, the majority within 24--48 hours. Three angiographic configurations of internal carotid occlusion were found, in descending order of frequency: a sharp, pointed stump; virtual absence of the artery; and a rounded, blunt stump. The results suggest that the angiographic appearance of the proximal occlusion alone may not accurately predict the age of the occlusion within the first 6 days from stroke onset.
Light touch thresholds in normal persons and cerebral vascular disease patient: bilateral deficit after unilateral lesion.
Authors: Essing J P , Gersten J W , Yarnell P
Published: June 2011

Sensory thresholds, using the 2-alternative forced choice technique, were studied in normal subjects and in patients with unilateral cerebral vascular disease, as documented by clinical-radiologic correlation. In normal person the absolute threshold for light touch increased with age. Bilateral impairment of sensation with unilateral cerebral vascular lesions occurred in 30% of the patients. Tactile deficit was always greater on the side contralateral to infarction or hemorrhage. An ipsilateral deficit did not exist independent of contralateral deficity, and was more likely to occur with complete sensory loss contralaterally. There was a tendency for persons with larger lesions as determined clinically and by CAT scan to have ipsilateral as well as contralateral deficit. The incidence or severity of ipsilateral deficit was not related to lesion laterality.
Survival under hypoxia. Age dependence and effect of cholinergic drugs.
Authors: Scremin A M , Scremin O U , Brechner T
Published: June 2011

Survival under hypoxia (5% O2; 95% N2) was tested in mice 1 day to 50-weeks-old. Survival Rate (ratio of number of animals that survived 30 min under 5% O2 to total number of animals exposed) and the time from onset of exposure until the last gasp (Survival Time) were maximum in newborn animals and decreased as a function of age. Survival Rate and Survival Time were strongly influenced by drugs affecting cholinergic transmission. Atropine decreased the high survival under hypoxia of 1-week-old mice in a dose-related manner. Physostigmine increased survival under hypoxia in mice 3 to 50-weeks-old. This effect was not related to a peripheral action of the drug since it was not mimicked by neostigmine, a cholinesterase inhibitor without central actions. Moreover, peripheral cholinergic blockade with glycopyrrolate, a quaternary cholinergic blocker, did not prevent the protective effect of physostigmine. Since atropine impairs the ability of very young mice to survive hypoxia and physostigmine improves survival at later ages, it is concluded that a central cholinergic mechanism, possibly related to blood flow regulation, plays a significant role in the acute adaptation to hypoxia.
Tissue pertechnetate and iodinated contrast material in ischemic stroke.
Authors: Anderson D C , Coss D T , Jacobson R L , Meyer M W
Published: June 2011

Isotope uptake during static radionuclide scanning and contrast enhancement during CT scanning, which may result from similar pathophysiologic mechanisms after ischemic infarction, were investigated in an animal model. Infarction was produced by transorbital occlusion of the middle cerebral artery in cats killed one, 2, 4, 8, or 16 days later. Sodium pertechnetate containing technetium-99m and 30% methylglucamine iothalamate labeled with I-125 were administered intravenously 60 and 15 min respectively prior to sacrifice. A coronal section through the infarct was parceled into 30 portions which were assayed for concentration of each isotope. Adjacent brain was prepared for histopathologic correlation. Concentrations of the 2 materials were highest in infarcted brain at 4 and 8 days. Strong positive correlation was found between tissue concentrations of the 2 materials in all brain samples. Elevated tissue levels correlated with necrosis, macrophage infiltration, and vascular hyperplasia. The results support the probability that radionuclide scan positivity and CT contrast enhancement reflect the same pathophysiologic development, probably extravasation of the respective labels, after ischemic stroke.
Primitive hypoglossal artery and carotid endarterectomy.
Authors: Pinkerton J A , Davidson K C , Hibbard B Z
Published: June 2011

A patient with transient ischemic symptoms in the carotid and vertebrobasilar distribution is reported. His arteriogram demonstrated a persistent primitive hypoglossal artery which in part may explain the clinical picture. The embryology, radiology, clinical manifestations, and surgical considerations of this rare anomaly are discussed.
Myocardial necrosis induced by breeding in stroke-prone/SHR.
Authors: Wexler B C
Published: June 2011

Virgin and breeder, spontaneously hypertensive and stroke prone rats (SHR/SP) were observed from weaning until 130 +/- 10 days of age. Blood pressure rose rapidly, reaching 230--240 mm Hg. After the birth of the second litter of pups, male and female breeders began to die suddenly, due to myocardial necrosis and congestive heart failure. At autopsy, the brains of virgin and breeder SHR/SP were swollen but were free of any pathologic changes. There were no significant alterations in the blood chemistry of virgin rats but breeder SHR/SP had super-normal enzyme levels, CPK, SGOT, SGPT and LDH, hyperglycemia, hyperlipidemia, and hypersecretion of corticosterone. Breeder SHR/SP developed PAN-like lesions of the mesenteric arcades and adrenal cortex along with severe fibrino-hyalin lesions of the testicular and ovarian arteries. It is suggested that alterations in hypothalamic-pituitary-adrenal function associated with the reproductive effort conditioned these SHR/SP to develop myocardial necrosis rather than stroke and the development of unusual hypertensive arteriopathy.
Enovid-induced exacerbation of high blood pressure in stroke-prone rats (SHR).
Authors: Wexler B C
Published: June 2011

Male and female, normotensive Wistar:Kyoto rats, spontaneously hypertensive rats (SHR), and Stroke-prone SHR (SHR/SP) with severe hypertension were treated with a contraceptive drug (Enovid) from the time of weaning until they became 180 days old. Although the Envoid-treated SHR and SHR/SP had exacerbations of their high blood pressure, none of the animals developed renal or cerebral damage. Chronic treatment with Enovid caused testicular and ovarian atrophy and a significant increase in circulating corticosterone. It is suggested that the potentially deleterious effects, e.g., stroke, hypertension, hyperglycemia, hyperlipidemia, etc., of chronic treatment with contraceptive drugs is largely determined by pre-existing genetically endowed proneness or resistance.
Lactoferrin, lysozyme, and beta 2-microglobulin in cerebrospinal fluid. Elevated levels in patients with acute cerebrovascular lesions as indices of inflammation.
Authors: Terent A , Hällgren R , Venge P , Bergström K
Published: June 2011

Serial determinations of beta 2-microglobulin, lactoferrin and lysozyme in CSF were performed in 14 patients with acute cerebrovascular lesions. Marked elevations were noted in patients with cerebral bleeding or hemorrhagic infarction. Patients with infarction without signs of bleeding or with cerebrovascular lesions undetectable by computed tomography also had an increase in these proteins. The increases in CSF of beta 2-microglobulin, lactoferrin and lysozyme could not be explained by a damaged blood-brain barrier but was believed to be a local product of the central nervous system. Peak levels of lactoferrin and lysozyme were noted on day 2-3 after onset of symptoms. Lactoferrin then declined while lysozyme remained elevated for another few days. beta 2-microglobulin gradually increased reaching peak levels on day 4-5 and remained elevated even 2 weeks after the onset of symptoms. We suggest that the increases of lactoferrin, lysozyme and beta 2-microglobulin reflect various inflammatory reactions mediated by granulocytes, macrophages and lymphocytes, respectively.
Contractile responses of pial arterioles in gerbils with unilateral carotid ligation.
Authors: Rosenblum W I
Published: June 2011

Studies were made in an effort to detect enhanced vasoconstriction ipsilateral to a ligated common carotid artery. No effect of ligation was found on the response to topically administered serotonin, norepinephrine or prostaglandin F2 alpha, in the gerbil in spite of varying a number of parameters, including anesthesia, percent of inspired oxygen, time elapsed following ligation, or body temperature at time of examination. The response was not influenced by the presence or severity of stroke symptoms. A stronger and less specific constrictor, BaCl2, did elicit a difference between the contractile response of ligated and sham operated gerbils. In 13 of the 18 studies, BaCl2 produced a greater constriction in the ligated gerbils, and in 9 of these studies that difference was statistically significant. In only one study was there a statistically significant contrary result. The enhanced contractile response to BaCl2 could not be related to the presence or severity of symptoms or to any other of the variables mentioned above. This suggests that it was probably related to reduced intraluminal pressure distal to the ligation.
Anterior spinal artery aneurysm presenting as a subarachnoid hemorrhage.
Authors: Vincent F M
Published: June 2011

A woman who presented with a subarachnoid hemorrhage secondary to a ruptured anterior spinal artery aneurysm of the spinal cord is reported. While this is the first report of a ruptured aneurysm of the anterior spinal artery with angiographic confirmation, it emphasizes that occasionally subarachnoid hemorrhage may be secondary to ruptured spinal artery aneurysms.
Mechanism of increased sensitivity to cerebral ischemia following carotid artery occlusion in stroke-prone spontaneously hypertensive rats: importance of genetic factors.
Authors: Suno M , Kakihana M , Shibota M , Nagaoka A
Published: June 2011

Neurological symptoms and cerebral metabolism following bilateral carotid artery occlusion (BCAO) were observed in stroke-prone spontaneously hypertensive rats (SHRSP), stroke-resistant SHR (SHRSR), normal Wistar-Kyoto rats (WKY) and the F1 and F2 hybrids between SHRSP and SHRSR or WKY. Systolic blood pressure recorded before BCAO was found to rank in the following order: SHRSP greater than F1 (SHRSP X SHRSR) greater than SHRSR greater than F1 (SHRSP X WKY) greater than WKY. The effect of BCAO in these rats tended to be proportional to the blood pressure. F1 (SHRSP X WKY) was more sensitive to brain ischemia than SHRSR. In addition, though none of the SHRSR (average blood pressure 155 mm Hg) developed acute stroke symptoms, many animals of the F2 generation, in which the blood pressure was equal to or lower than that of SHRSR, developed stroke symptoms. Lactate and ATP changes in the F2 generations did not correlate with the blood pressure. The results suggest that genetic factors may play an important role in susceptibility to brain ischemia in the stroke-prone rats.
Regional cerebral blood flow in stroke by 133Xenon inhalation and emission tomography.
Authors: Lassen N A , Henriksen L , Paulson O
Published: June 2011

A rapidly rotating single-photon emission tomograph was used to study regional cerebral blood flow by 133Xenon inhalation. Using a rotation speed of 180 degrees/5 sec a tomographic picture of the average Xenon concentration in 3 slices is obtained. By taking a sequence of 4 one-minute tomograms during and after a one-minute 133Xenon inhalation period a flow-dependent variation in local isotope concentration is seen. This sequence is used for calculating CBF by a deconvolution procedure. The CBF maps have a spatial resolution of approximately 1.7 cm (FWHM). This preliminary study comprises normal subjects and 10 unselected patients with stroke. The CBF tomograms localized appropriate ischemic areas in all 10 patients. In one patient the conventional x-ray tomogram was negative, while the flow tomogram clearly showed a decreased flow in consonance with the clinical findings. Regional cerebral blood flow measured tomographically by 133Xenon inhalation circumvents the extra-cranial contamination and the superposition of intracranial tissues that hamper 133Xenon inhalation flow studies using stationary detectors.
Subarachnoid hemorrhage in middle-Finland: incidence, early prognosis and indications for neurosurgical treatment.
Authors: Fogelholm R
Published: June 2011

The incidence of subarachnoid hemorrhage (SAH) in Middle-Finland 1976-78 was 19.4/100,000/year. The incidence increased consistently with age. The early prognosis was similar to that in earlier studies, with 25% dying on the first day, and 49% during the first 3 months after the initial bleeding. The fatality rate decreased sharply after the bleeding: of all deaths during the first 3 months, the weekly fatality rate was 65% during the 1st week, 12% during the 2nd, and 4% during the 3rd. Thereafter the weekly fatalities up to 3 months averaged 1.6%. Only 20% of the patients of the entire series were assessed as being eligible for neurosurgical treatment. Intercurrent fatal rebleeds further reduced this number. The chances of increasing the number of SAH patients suitable for neurosurgery are discussed. The timing of surgery should be earlier than in the present study (median 15 days after the bleeding) in order to avoid frequently fatal recurrences. Vertebral angiograms should be obtained from patients with no aneurysms found by bilateral carotid angiography. The upper age limit of 60 years should be abolished. By these means the proportion of SAH patients potentially eligible for neurosurgery could be increased to about 40%.
Cerebral blood flow and intracranial pressure in the dog during intravenous infusion of nitroglycerin alone and in combination with dopamine.
Authors: von Essen C , Kistler J P , Lees R S , Zervas N T
Published: June 2011

Nitroglycerin, long known as a safe and effective dilator of the large coronary arteries, has recently been shown to dilate the basilar artery of the dog after experimentally induced vasospasm. In this study we have evaluated the effects of intravenous nitroglycerin on local cerebral blood flow (H2 clearance technique) and intracranial pressure (intracisternal needle monitor) in normal beagle dogs (Group 1). In each of 7 dogs, infusion of nitroglycerin at rates of 3, 5, and 10 microgram/kg/min did not change blood flow in the right and left caudate nucleus, thalamus, frontal and parietal cortex. Autoregulation of cerebral blood flow remained unimpaired and intracranial pressure remained stable during nitroglycerin infusion. The effects of a combination of intravenous nitroglycerin and dopamine on local cerebral blood flow was evaluated in another group of normal beagle dogs (Group 2). Local cerebral blood flow decreased or remained unchanged in response to intravenous infusion of dopamine at low rates, increased in response to moderate rates and again decreased in response to high infusion rates. These dopamine induced changes in blood flow occurred whether or not nitroglycerin was infused simultaneously. When the vasoconstrictor activity of dopamine was blocked by phentolamine or methysergide, local cerebral blood flow increased at moderate and high infusion rates, again whether or not nitroglycerin was infused simultaneously. Our data suggest that nitroglycerin affects mainly the extracerebral capacitance arteries while dopamine affects the smaller intraparenchymal resistance vessels. Nitroglycerin has little effect on cerebral blood flow even when used in combination with dopamine.
Ethanol intoxication: a risk factor for ischemic brain infarction in adolescents and young adults.
Authors: Hillbom M , Kaste M
Published: June 2011

Between January 1978 and December 1979 23 consecutive patients aged under 40 years with acute ischemic brain infarction were admitted to the department of neurology, Meilahti University Hospital in Helsinki. In 10 patients (43%) the onset of symptoms was preceded within 24 hours by ethanol intoxication, and all but one symptom occurred at weekends when most liquor is consumed in Finland. Ethanol intoxication preceding the stroke was 4 times as common in female and 5 times as common in male patients as ethanol intoxication in the general Finnish population of the same age and sex. The present results support those of our previous study and suggest that occasional ethanol intoxication increases the risk of ischemic brain infarction both in adolescents and young adults.
Differential contributions of major lipid components of atheroma to outcome of cerebral atheroembolism. A study in an animal model.
Authors: Rail D L , Steiner T J , Rose F C
Published: June 2011

Cerebral atheroembolism, in which mainly lipid emboli are released from rupturing atheromatous plaques, may occur without apparent effect, or result in cerebral ischemia and infarction. The reasons behind these unpredictable consequences were sought in the interaction, in vitro and in an animal model, between the main lipid components of advanced plaques. Pure preparations of representative lipids were each harmless when embolized into the cerebral circulation. In contrast, combinations in proportions similar to those in advanced human plaques caused infarction, whether these were synthetic mixtures or extracts from plaques of the entire lipid fraction. The most important physical interaction between the lipids was aggregation of crystals by oils. Between cholesterol and the mainly liquid esters, this created in vitro a range of glutinous aggregates. Triglyceride lowered the melting point of esters, increasing their oiliness, and reduced the cohesiveness of aggregates in the face of operative mechanical forces through a fall in viscosity. Phospholipid, acting principally as an emulsifying agent, promoted dispersion of the oil, secondarily freeing the crystals from its aggregating effect. In the plaque, the balance of these factors will determine the size and number of particles likely to embolize, and, therefore, the clinical outcome should the plaque rupture.
Sonographic demonstration of fibromuscular hyperplasia of the cervical internal carotid artery.
Authors: Edell S L , Huang P
Published: June 2011

Ultrasound examination of the carotid artery has recently become an accepted procedure in screening patients with transient ischemic attacks. We report a patient with fibromuscular hyperplasia of the carotid artery diagnosed successfully with digital gray scale contact ultrasonic scanning and confirmed with arteriography.
Cerebrovascular disease in Utah, 1968--1971.
Authors: Lyon J L , Bishop C T , Nielsen N S
Published: June 2011

Utah mortality rates for cerebrovascular disease (ICD numbers 430--438) are 13% below U.S. rates. About 70% of Utahns are members of the Church of Jesus Christ of Latter-day Saints, commonly called Mormons of LDS, which proscribes use of tobacco and alcohol. Other studies on this group have found significantly lower occurrence of many cancers and ischemic heart disease. We tested the hypothesis that Utah's lower cerebrovascular disease (CBVD) mortality was contributed by the LDS population. We classified by religion all CBVD deaths (2,521) (except subarachnoid hemorrhage and cerebral embolism) occurring in the state in 1968--1971. No significant difference was found between LDS and non-LDS, but both groups had mortality rates below U.S. expectation. Although recent studies have reported smoking to be a risk factor for CBVD, we found no consistent difference between the LDS and non-LDS, even in the younger age groups. The results do not support the hypothesis that tobacco is an important etiologic agent in CBVD mortality.
Selective lenticulostriate occlusion in the primate. A highly focal cerebral ischemia model.
Authors: Yonas H , Wolfson S K , Dujovny M , Boehnke M , Cook E
Published: June 2011

A highly reliable model for the study of focal cerebral ischemia has been developed using a retro-orbital approach to occlude the lateral lenticulostriate arteries of the baboon. An infarction of the caudate, putamen and the anterior limb of the internal capsule has consistently been produced. Reliability has been attained because the anatomical variations of the lenticulostriate arteries of each animal can be fully appraised, permitting selective vessel occlusion. A well-defined clinical and radiographic lesion has also resulted from this procedure which was clinically well tolerated by all animals. Selective lenticulostriate occlusion provides a new approach to the study of focal cerebral ischemia in the sub-human primate, and serves for the evaluation of proposed therapies for treatment of focal cerebral ischemia.
Simultaneous measurement of blood flow and glucose metabolism by autoradiographic techniques.
Authors: Mies G , Niebuhr I , Hossmann K A
Published: June 2011

A double tracer autoradiographic technique using 131I-iodo-antipyrine and 14C-deoxyglucose is presented for the simultaneous measurement of blood flow and cerebral glucose utilization in the same animal. 131I is a gamma emitting isotope with a half life of 8.06 days and can be detected with adequate resolution on standard autoradiographic films. Autoradiograms are made before and after decay of 131I; the time interval between the 2 exposures and the concentration of the 2 tracers is adjusted to avoid significant cross-contamination. In this way, 2 film exposures are obtained which can be processed quantitatively like single tracer autoradiograms. The validity of the method for the investigation of local coupling of flow and metabolism was tested under various physiological and pathophysiological conditions. Coupling was tight in barbiturate-anesthetized healthy animals, but not under halothane anesthesia where uncoupling occurred in various subcortical structures. Focal seizures induced by topical application of penicillin on the cortical surface led to a coupled increase of metabolism and flow in thalamic relay nuclei but not at the site of penicillin administration where increased glucose utilization was not accompanied by similar increase in blood flow. Both coupled and uncoupled increases in local glucose utilization were observed in spreading depression and in circumscribed areas of experimental brain tumors. The results obtained demonstrate that double tracer autoradiography allows allows the very precise local assessment of cerebral blood flow and glucose utilization, and, therefore, is particularly suited to the study of regional coupling processes under various experimental conditions.
Use of 123I and 14C in a double radionuclide autoradiographic technique for simultaneous measurement of LCBF and LCMRgl. Theory and method.
Authors: Lear J L , Jones S C , Greenberg J H , Fedora T J , Reivich M
Published: June 2011

We have developed an autoradiographic technique for the simultaneous measurement of local cerebral blood flow (LCBF) and local cerebral metabolic rate for glucose (LCMRgl) using 123I-iodoantipyrine and 14C-2-deoxyglucose respectively. By exploiting the different half-lives of 123I and 14C, 13.0 hours versus 5730 years, we produce 2 autoradiographic images. The first is predominantly a result of the 123I and the second is predominantly from the 14C. Because of the impracticality of making 123I standards, it was necessary to determine the constant which relates the ability of 123I, with respect to 14C, to expose Kodak SB-54 film, so that the 123I exposure could be quantified using 14C standards. Subtraction equations can then be used to solve for the local 123I and 14C concentrations. The technique was validated in conditions simulating a 12-fold decoupling of flow and metabolism and the standard deviation of error in measuring tracer concentrations was less than 6%. It was then used to measure these parameters in the normal awake rats and values obtained agreed well with published values from single radionuclide studies. The technique is expected to be useful in the simultaneous measurement of LCBF and LCMRgl in various physiologic or pathologic states, including those with significant decoupling of flow and metabolism. In addition, by using other tracers labelled with 123I and 14C, other parameters can be measured concurrently.
Cerebral autoregulation: an in vitro study.
Authors: Vinall P E , Simeone F A
Published: June 2011

Cerebral autoregulation can be duplicated in vitro using the large middle cerebral arteries from a calf. The limits of autoregulation were between 50 and 150 mm Hg. Excessively high pressures may lead to the appearance of the "sausage- or bead-string" response followed by forced dilation. These results suggest the existence of an intrinsic myogenic mechanism responsive to intraluminal pressure changes.
A case for cerebral thromboangiitis obliterans.
Authors: Biller J , Asconapé J , Challa V R , Toole J F , McLean W T
Published: June 2011

The existence of cerebral thromboangiitis obliterans (CTAO) has been controversial. The clinical, laboratory and angiographic features of a young woman with recurrent thrombophlebitis, digital gangrene and a bilateral anterior opercular syndrome (Foix-Chavany-Marie) are reported. The cerebral angiogram demonstrated significant narrowing of fronto-opercular branches of both middle cerebral arteries. Histology of small digital muscular arteries revealed segmental adventitial fibrosis, narrowing or occlusion of lumen and mild lymphocitic infiltrates; occasional veins showed phlebitis. An etiologic relationship between cerebral occlusive disease and peripheral thromboangitis obliterans (TAO) is suggested.
Transient vertical monocular hemianopsia with anomalous retinal artery branching.
Authors: Wolpow E R , Lupton R G
Published: June 2011

A 62-year-old man reported 6 stereotyped attacks of transient loss of vision in the lateral visual field of the right eye and was subsequently found to have right internal carotid artery occlusion. Fundoscopy revealed an anomalous central retinal artery branching whereby a single stem vessel supplied the superior and inferior nasal quadrants of the retina. Circulatory insufficiency in this anomalous stem could explain the occurrence of vertical monocular hemianopsia as an unusual manifestation of ipsilateral carotid artery atherosclerosis.
Carotid occlusive disease: effect of complete occlusion of internal carotid artery on intraocular pulse/pressure relation and on ophthalmic arterial pressure.
Authors: Langham M E , To'mey K F , Preziosi T J
Published: June 2011

The intraocular pressure (IOP), the intraocular pulse to pressure (pulse/pressure) relationship, and the ophthalmic arterial pressure have been measured in 20 patients with either unilateral or bilateral hemodynamically significant lesions of the internal carotid arteries (ICA) as determined from arteriography. Studies were repeated in 5 of hte patients after surgical endarterectomy on the obstructed ICA. In age matched normal subjects the pulse/pressure relations were symmetrical in pairs of eyes, and the ophthalmic arterial systolic pressure was 89.0 +/- 2.1 mm Hg; this was 66 +/- 1% of the brachial arterial systolic pressure. In 19 of 20 patients with carotid occlusive disease in this study the IOP, pulse amplitudes and the pulse/pressure relationships differed in pairs of eyes. The ophthalmic arterial systolic pressure on the sides with 95 to 100% ICA stenosis was 49.9 +/- 4.05 mm Hg, which was 33 +/- 3% of the brachial arterial systolic pressure. In the remaining eyes the degree of stenosis of the ipsilateral ICA was 36.5 +/- 7.9%; the corresponding eyes had an ophthalmic arterial systolic pressure of 70.f1 +/- 51.18 mm Hg, which was 45 +/- 4% of the brachial arterial systolic pressure. Endarterectromy of the occluded arteries caused a significant increase in the ophthalmic arterial pressure on the ipsilateral side and a smaller increase in the contralateral eye; these changes were associated with a statistically significant increase in the intraocular pulse and improvement in the pulse/pressure relation.
Changes in vasoactive properties of blood products with time and attempted identification of the spasmogens.
Authors: Okwuasaba F , Cook D , Weir B
Published: June 2011

The contractile activity of various fresh, or incubated blood fractions was studied in vitro using the isolated canine basilar artery. Significantly greater contraction was induced by fresh platelet rich plasma (PRP) and serum compared to red blood cells (RBC). Following incubation, the contractile activity of RBC increased, reaching a plateau at day-3 and it was maintained for at least 14 days, while both PRP and serum lost most of their activity after 24 h of incubation. The contractions induced by fresh blood fractions were only partially blocked by desensitization of 5-hydroxytryptamine (5-HT) receptors or by the 5-HT antagonist methysergide. D-600 effectively antagonized the response to all blood fractions. Biochemical analysis of the incubated RBC by means of Sephacryl S-200 column chromatography and SDS-urea polyacrylamide gel electrophoresis revealed that the contractile substance possessed a molecular weight of about 60,000 daltons. Vasoactivity was only present in one peak of the chromatographically eluted fractions which was shown to possess a similar absorption spectrum to that of hemoglobin. Hemoglobin concentration was highest in day 3, 7, and 14 fractions and may be correlated with the contractile activity of incubated samples.
Cerebral oxygen availability and blood flow during middle cerebral artery occlusion: effects of pentobarbital.
Authors: Feustel P J , Ingvar M C , Severinghaus J W
Published: June 2011

To determine whether barbiturate administration can improve oxygenation, oxygen availability (aO2) and local cortical blood flow (ICBF) were measured in cats before and during middle cerebral artery occlusion (MCAO) using 10 platinum electrodes distributed over the cortex. Halothane/N2O anesthesia was used during the surgical preparation and N2O with a relaxant thereafter. After 15 to 30 min of MCAO, 50 mg/kg of pentobarbital was infused slowly. Measured from electrodes in severely ischemic cortex, aO2 increased if the blood pressure was maintained with dopamine. Control animals in which no pentobarbital was given showed no change in aO2 over the same period of time. In areas of cortex not affected by middle cerebral artery occlusion the aO2 did not change from control values despite a decrease in blood flow from 72.7 +/- 49.8 to 48.9 +/- 26.7 ml/min/100 g. Thus, pentobarbital appears to decrease ICBF and metabolism proportionally in well perfused cortex so that aO2 remains constant, while improving the flow to metabolism ratio in poorly perfused cortex so that aO2 rises.
Incomplete transient ischemia: a non-destructive evaluation of in vivo cerebral metabolism and hemodynamics in rat brain.
Authors: Wiernsperger N , Sylvia A L , Jöbsis F F
Published: June 2011

Differential near infrared spectrophotometry was used to monitor sequential in vivo alterations in cerebral hemoglobin saturation, blood volume, and cytochrome c oxidase reduction/oxidation responses during and after a period of incomplete transient ischemia (acute, reversible common carotid artery occlusion). In this study the rat brain was monitored non-invasively in the intact skull by transillumination. The data show that an increase in cerebral deoxygenation of hemoglobin, which occurs simultaneously with a decrease in blood volume subsequent to carotid ligation, acts as a compensatory mechanism to assist in maintaining aerobic energy metabolism. The observations also demonstrate that in this species the effects of bilateral carotid occlusion on the cerebrovascular parameters are not necessarily irrevocable. The intramitochondrial metabolic alterations, as evaluated by cytochrome c oxidase redox transitions, are reversible as long as the systemic arterial blood pressure does not fall below a value of approximately 40 mm Hg. These data suggest that possibility of being able to use a critical reduction level of cytochrome c oxidase as an early indication of ischemia-induced cerebral metabolic dysfunction prior to major changes in high energy stores.
Failure of brain cytochrome alpha , alpha 3 redox recovery after hypoxic hypotension as determined by in vivo reflectance spectrophotometry.
Authors: Proctor H J , Sylvia A L , Jöbsis F
Published: June 2011

Rats were subjected to a 30 minute period of combined hypoxia (F1o2 = .08) and hemorrhagic hypotension (MAP = 30 mm Hg), then resuscitated by restoration of F1o2 = .30 and reinfusion of shed blood and saline. Intracranial blood volume, hemoglobin saturation, and the cytochrome alpha, alpha 2 redox state were monitored through the intact skull during hypoxic hypotension and after resuscitation utilizing reflectance spectrophotometry. Although resuscitation returned arterial blood pressure, arterial pO2, and hemoglobin saturation toward normal, a sustained, significant (p less than .005) reduction in cytochrome alpha , alpha 2 remained. A parallel series of rats was subjected to identical hypoxic hypotension. At designated intervals the animals were sacrificed to determine brain ATP, ADP, and inorganic phosphate (P1). The data are discussed in terms of relationships between high energy phosphate metabolism and recorded changes in cerebral cytochrome alpha , alpha 2 redox state.
Cerebral atheroembolism. An animal model.
Authors: Jeynes B J , Warren B A
Published: June 2011

Human atheromatous material was injected into the cerebral vasculature of anaesthetized rabbits via the left common carotid artery. The lethality of varying dosages was determined and the distribution and general character of occlusive vascular lesions which developed were analyzed by light and transmission electron microscopy. It was found that a dose exceeding 55 mg of the atheromatous material (125 mg/ml saline) was lethal in New Zealand white male rabbits weighing between 3 and 5 kg. In nonsurviving animals, parts of the Circle of Willis and usually one or more of its major tributaries were occluded. Some surviving animals exhibited signs of neurologic deficit evidenced by motor dysfunction. Occlusive vascular lesions found in surviving animals were predominantly localized in ipsilateral cortical and subcortical vessels within the distribution territory of the middle cerebral artery. The character of occlusive lesions showed strong evidence of thrombosis. These results demonstrated that this experimental system may be useful as a model for the study of blood-atheroembolic vascular reactions, cerebral infarction development and the testing of agents potentially prophylactic against the development or stabilization of occlusive lesions.
Pattern difference of reversed ophthalmic blood flow between occlusion and stenosis of the internal carotid artery. An ultrasonic Doppler study.
Authors: Kadota E , Kaneda H , Makinaga G , Taneda M , Irino T
Published: June 2011

Reversed ophthalmic blood flow in the occlusions (33 patients) and stenoses (11 patients) of the internal carotid artery (ICA) was examined using the ultrasonic Doppler technique. The Doppler shift frequencies of the blood flow signal were analyzed to obtain their sound spectrogram. In stenosis of the ICA, "presystolic notch" was more frequently observed and "d/S" value (S, d; maximum blood flow velocity at systolic and diastolic) was smaller than in occlusion. These two characteristics of stenosis distinguish it from occlusion with 89% accuracy although this method is applicable only for the patients with reversed ophthalmic blood flow.
Cerebral hemorrhage in neonates with coarctation of the aorta.
Authors: Young R S , Liberthson R R , Zalneraitis E L
Published: June 2011

Coarctation of the aorta is an uncommon cause of cerebral hemorrhage in the full- or near-term infant. The clinical, radiologic, and neurologic findings of four infants with aortic coarctation and cerebral hemorrhage are presented. In all four infants, cerebral hemorrhage was associated with only moderate elevation of systolic blood pressure (90-110 mmHg).
Cerebrovascular disease type specific mortality: 1968-1977.
Authors: Baum H M , Goldstein M
Published: June 2011

Death certificates for the period 1968-1977 were examined to determine the trend, in the United States, of cerebrovascular disease death rates by type of event and demographic subgroup. The largest declines were for hemorrhagic strokes and among nonwhites. The number of hemorrhagic stroke deaths declined by 45 percent and th age-adjusted rate declined by 53 percent. Similar figures for nonwhites were 18 percent and 36 percent, respectively. It was surprising to note that the number of cerebrovascular deaths reported as poorly defined rose by 17 percent. Data on hypertension were examined. The possibility that the results with respect to hypertension are artifactual indicates the need for clinical studies which will examine the relationship between hypertension and cerebrovascular disease mortality.
Interference between central dopaminergic stimulation, and adrenal secretion in normoxic or hypobaric hypoxic rats.
Authors: Saligaut C , Moore N , Chretien P , Daoust M , Richard O , Boismare F
Published: June 2011

Previous data have established that postsynaptic stimulation of central dopaminergic receptors was mainly involved in the protective action of apomorphine against the comportmental consequences of hypobaric hypoxia in rats: disturbances in a conditioned avoidance response. We confirm this notion showing that domperidone (a peripheral dopaminergic blocking agent) does not antagonize the protective effect of apomorphine. Furthermore, we establish that the action of apomorphine is at least partially mediated by adrenal glands since it is no longer seen in adrenalectomized rats. In normal rats, apomorphine enhances the corticosterone increase which is observed during hypobaric hypoxia and decreases the hypoxia-induced elevation of the adrenaline level. It is therefore concluded that the anti-hypoxic activity of apomorphine is probably mediated by a centrally mediated dopaminergic modification of the adrenal response to hypobaric hypoxia.
Sonic detection of intracranial aneurysm and AVM.
Authors: Kosugi Y , Goto T , Ikebe J , Johshita H , Takakura K
Published: June 2011

This paper describes a method of detecting intracranial aneurysm and arteriovenous malformation (AVM) by analysing weak sounds produced by the blood circulation at the affected part. There is thought to be no turbulence in the normal cerebrovascular system, whereas abnormalities such as aneurysm and AVM sometimes cause turbulence in the blood flow. Thus, a small fraction of the flow energy might be converted into an acoustically detectable noise. For the detection of the sound, sensitive detectors must be applied close to the head since the sound is very weak, and, as in cerebrovascular diseases, the origin of the sound is usually concealed deep inside the hard shelter of the skull. The detection system we used had a gain of 40 to 50 dB greater than that of an ordinary stethoscope. The detection points were the teeth or forehead. Usually the sound started about 160 msec after the ventricular contraction and lasted for 100 to 400 msec. Its frequency component mostly ranged from 400 to 2000 Hz, but the spectrum profile changed according to the position and degree of abnormalities. The uttered sound was very random, which facilitated detection of the position of the sound origin by means of cross correlation methods using a pair of detectors. This method is completely noninvasive, causes no pain to the patient, and might be used even in mass examinations.