Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two cases of spontaneous cerebral ventriculostium are presented. The first case is that of a 3 year-old girl with a thumb-sized soft scalp tumor of the occipital region (dural hypertrophy) and hydroencephalodysplasia (Picaza). PVG revealed noncommunicating hydrocephalus with asymmetrical deformity of the lateral ventricle and agenesis of corpus callosum (Fig. 1). Ventriculoatrial shunt was performed. Three years passed under the useful life when she readmitted to our clinic complaining headache, nausea and vomiting. On the first hospital day she fell into respiratory arrest accompanied with coma after the tonic convulsion, and eventually, she died on the fourth hospital day. Postmortem examination revealed spontaneous cerebral ventriculostium which communicated with the posteromedial trigone of the left lateral ventricle (Fig. 3). Combined other malformations such as dysgenesis of the corpus callosum and only one anterior cerebral artery, etc. were found. The second case is that of a young adult, a 22 year-old male with rapidly progressing intracranial hypertension. PVG revealed marked dilatation of the lateral and the third ventricle, non-filling of the aqueduct and spontaneous cerebral ventriculostium which communicated with the posterior part of the third ventricle (Fig. 4). And insidiously he fell into akinetic mutism. After suboccipital exploratory craniotomy and ventriculo-peritoneal shunt akinetic mutism improved gradually, and he was discharged on foot after 7 months. PEG performed on June 8, 1973, showed no evidence of aqueduct obstruction and injected air passed from the fourth ventricle to the third one smoothly. He lives on now under a useful condition. These 2 cases are the first report on literatures in Japan, but presumably there must be many other cases. Since W. H. Sweet reported his own two cases of spontaneous cerebral ventriculostium on 1940, more than thirty cases have been published on literatures. However, there are found various expressions to describe the same condition (Table 1). We would like to propose that the most suitable expression is "ventriculostium" not only in deference to the originality of W. H. Sweet but also not to confuse this pathogenetic state with other similar conditions. The author's next interest is the chronological fact that from W. H. Sweet (1940) to A. Torkildsen (1948), all but one ostiums reported situated at the posteromedial trigone of the lateral ventricle, whereas after A. Torkildsen, they were found at the posterior part of the third ventricle in many cases. The reason is unknown. It would appear that three main conditions are necessary for the development of ventricluostium just beneath the tentorium. The first, there must be increased pressure within the lateral or the third ventricle. The second essential feature is the lack of any large space occupying lesion in the the infratentorial space. The third, there must be wider space between the tentorial incisura and the brain stem.
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PMID:[Spontaneous cerebral ventriculostium (author's transl)]. 94 70

The brain vascular perfusion method, with a multiple-time brain uptake analysis, has been employed to study the effects of chronic amphetamine intoxication on the kinetics of entry of 2 inert polar molecules, D-[14C]mannitol (mol.wt. 180) and [3H]polyethylene glycol (PEG, mol.wt. 4000) into the forebrain of the guinea pig. The unidirectional transfer constants, Kin, determined from graphic analysis 14 and 20 days after chronic amphetamine treatment (5 mg/kg daily, i.p.) showed a marked time-dependent progressive enhancement of transfer for both molecules. The kinetic features of this entry suggest the opening up of pathways through the blood-brain barrier (BBB) which allows mannitol and PEG to pass into the brain at rates which are irrespective of their molecular size and/or lipophilia and these changes cannot be attributed to simple mechanical factors such as hypertension. This opening of the BBB was associated with changes in behaviour (increased locomotor activity, stereotypy, hypervigilance, social withdrawal, and loss of weight) seen in 14- and 20-day amphetamine-treated animals. At 7 and 28 days after the withdrawal of the amphetamine treatment, the behavioural manifestations were absent, and the Kin values for both molecules were not significantly different from those measured in normal control animals which had been treated with placebo injections. The present results suggest a reversible dysfunction of the BBB as a consequence of the chronic amphetamine intoxication which correlates with the behavioural syndrome induced in the guinea pig.
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PMID:Chronic amphetamine intoxication and the blood-brain barrier permeability to inert polar molecules studied in the vascularly perfused guinea pig brain. 251 57

Using noninvasive (echoventriculometry (Echo-VM), REG and invasive (planimetric PEG, graphic recording of the CSF pressure) methods of examination, the authors determined the size of cerebral ventricles and the status of the cerebral hemo- and CSF dynamics in 606 patients with various chronic diseases of the brain (consequences of craniocerebral injury, epilepsy, discirculatory encephalopathy, etc.). According to PEG and Echo-VM findings, two groups of patients were distinguished. In moderate dilatation of cerebral ventricles the most significant finding was an increase in the pulse pressure of the CSF, whereas its mean pressure was normal or slightly elevated. In patients with pronounced hydrocephaly the pulse and mean pressure of the CSF tended to decrease. The progress of hydrocephaly was parallelled by increasing disorders of the cerebral hemodynamics expressed in hindered venous outflow from the cranial cavity and elevated peripheral vascular resistance. Four CSF-related syndromes have been identified (normotension, total CSF hypertension, intraventricular tension, total CSF hypotension) differing in their diagnostic and prognostic significance and in the pathogenesis of disorders of the hemo- and CSF dynamics.
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PMID:[Status of the ventricular system and dynamics of the cerebrospinal fluid changes in chronic brain diseases]. 325 71

Eighteen patients with pre-eclampsia, 10 patients with essential and 9 with transient hypertension during pregnancy, were investigated regarding circulating immune complexes by a Clq-binding assay and a PEG precipitation assay. The women were studied during pregnancy, 2 and 5 days after childbirth, and also 3 and 6 months afterwards. The frequency of circulating immune complexes was not significantly increased in any of the groups when compared with that in 18 normotensive pregnant control subjects and 19 non-pregnant controls. Thus Clq-binding and PEG-precipitable immune complexes are a feature neither of normal pregnancy, nor of pregnancy complicated by hypertension or pre-eclampsia.
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PMID:Circulating immune complexes and hypertension in pregnancy. 644 Apr 5

In a 30 years period, 42 children were admitted for optic nerve and chiasm gliomas; 20 patients aged less than 5 years and 22 between 6 and 16 years. Duration of symptoms ranged from 13.15 months in children aged less than 5 years, to 10.18 months in patients aged more than 6. Onset of symptoms were characterized by visual impairment and/or proptosis in 73.8%, diencephalic disorders in 16.6% and intracranial hypertension in 9.5%. All patients underwent skull X-rays; 31 had a PEG taken and 12 a CT scan. Surgery was prompted in 27 patients, 2 of which died in postoperative course. Radiotherapy was the treatment of choice in the other 15 patients, 40 patients were followed up: the best results were obtained in the group of patients operated on and irradiated.
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PMID:Optic nerve and chiasm gliomas in children. 714 83

The effects of recombinant human interleukin-2 covalently linked to polyethylene glycol (PEG-IL-2) or interleukin-2 (IL-2) on hypertension and in vitro suppressor T cell function in the spontaneously hypertensive rats (SHR) were investigated. Male young prehypertensive (4 weeks old) SHRs and adult (10 weeks old) SHRs with established hypertension were injected with low (5,000 units (u)/kg) or high (50,000-100,000 u/kg) dose of PEG-IL-2 or IL-2 as a single bolus or repeated injections. Systolic blood pressure was measured twice weekly using the tail-cuff technique. Systolic blood pressure in the PEG-IL-2 or IL-2 treated animals, irrespective of age, dose, or route of injection, did not differ significantly from that measured in vehicle-treated controls over a 10 week period. Mean arterial pressure measured by intra-arterial catheter was 159 +/- 7 mm Hg 10 weeks after treatment with repeated injections of 5,000 u/kg of PEG-IL-2 and 158 +/- 9 mm Hg in vehicle-treated controls. All rats injected with IL-2 had IL-2-specific IgG antibody in their sera. None of the PEG-IL-2 treated rats had any detectable anti-IL-2 antibodies in their sera. Thus, PEG-IL-2 showed far less immunogenicity than IL-2. Suppressor T (Ts) cells generated from adult SHR spleen cells failed to suppress pokeweed mitogen (PWM)-driven immunoglobulin G (IgG) synthesis. PEG-IL-2 or IL-2 supplementation both in vitro and in vivo restored the ability of adult SHR to generate Ts cells able to inhibit IgG synthesis. Our data suggest that PEG-IL-2 or IL-2 administration does correct a prominent defective Ts cell activity found in adult SHR, but that correction of this immune abnormality is not attended by an attenuation of hypertension.
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PMID:The effects of PEG-interleukin-2 and interleukin-2 on essential hypertension and cellular immune function in the spontaneously hypertensive rat. 846 27

This study tested the hypothesis that depressor responses caused by tempol are not associated with reductions in vascular O2- levels in urethane-anesthetized deoxycorticosterone acetate (DOCA)-salt hypertensive rats. We compared the effects of intravenous (IV) administration of tempol, apocynin, superoxide dismutase-polyethylene glycol (PEG-SOD), and SOD on mean arterial blood pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA). In DOCA-salt rats, tempol (30 to 300 micromol/kg) dose-dependently decreased RSNA, MAP, and HR. Tempol (300 micromol/kg) decreased MAP from 140+/-5 to 83+/-4 mm Hg (P<0.05). HR decreased from 435+/-15 to 390+/-12 bpm (P<0.05). RSNA was reduced by 54%+/-6% from baseline. However, in the same rats, tempol did not reduce dihydroethidium-induced fluorescent signals in the aorta and vena cava. Apocynin (200 micromol/kg) did not lower MAP (142+/-5 mm Hg versus 140+/-6 mm Hg) or HR (428+/-15 bpm versus 420+/-13 bpm) and apocynin did not potentiate depressor responses caused by tempol. PEG-SOD (10 000 U/kg, bolus or 5000 U/kg bolus followed by a 30-minutes infusion of 500 U/kg/min) or SOD (25 000 U/kg, bolus or 10 000 U/kg bolus followed by a 30-minutes infusion of 1000 U/kg per minute) did not alter MAP or HR. It is concluded that depressor responses and decreases in HR and RSNA caused by acute tempol treatment are caused by direct sympathetic nerve activity inhibition that is not accompanied by SOD-mimetic action in the aorta or vena cava.
Hypertension 2004 Feb
PMID:Tempol lowers blood pressure and sympathetic nerve activity but not vascular O2- in DOCA-salt rats. 1470 56

The hypertensive effect observed with most cell-free haemoglobins has been proposed to result from NO scavenging. However, a newly developed PEG [poly(ethylene glycol)]-conjugated haemoglobin, MalPEG-Hb [maleimide-activated PEG-conjugated haemoglobin], is non-hypertensive with unique physicochemical properties: high O2 affinity, low co-operativity and large molecular radius. It is therefore of interest to compare the ligand-binding properties of MalPEG-Hb with unmodified cell-free HbA (stroma-free human haemoglobin). NO association rates for deoxy and oxyMalPEG-Hb and HbA were found to be identical. These results confirm the lack of correlation between hypertension and NO for a similar modified haemoglobin with high molecular radius and low p50 (pO2 at which haemoglobin is half-saturated with O2) [Rohlfs, Bruner, Chiu, Gonzales, Gonzales, Magde, Magde, Vandegriff and Winslow (1998) J. Biol. Chem. 273, 12128-12134]. The R-state O2 association kinetic constants were also the same for the two haemoglobins. However, even though the p50 of MalPEG-Hb is approx. half of that of HbA, the biphasic O2 dissociation rates measured at relatively high pO2 (150 Torr) were 2-fold higher, giving rise to a 2-fold lower R-state equilibrium association constant for MalPEG-Hb compared with HbA. Thus the O2 affinity of MalPEG-Hb is higher only at pO2 values lower than the intersection point of the O2 equilibrium curves for MalPEG-Hb and HbA. In summary, the present studies found similar rates of NO binding to HbA and MalPEG-Hb, eliminating the possibility that the lack of vasoactivity of MalPEG-Hb is simply the result of reduced molecular reactivity with NO. Alternatively, the unique O2-binding characteristics with low p50 and co-operativity suggest that the 'R-state' conformation of MalPEG-Hb is in a more T-state configuration and restricted from conformational change.
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PMID:Kinetics of NO and O2 binding to a maleimide poly(ethylene glycol)-conjugated human haemoglobin. 1517 10

Recently, it was demonstrated that superoxide oxidizes dihydroethidium to a specific fluorescent product (oxyethidium) that differs from ethidium by the presence of an additional oxygen atom in its molecular structure. We have adapted this new HPLC-based assay to quantify this product as a tool to estimate intracellular superoxide in intact tissues. Ethidium and oxyethidium were separated using a C-18 column and quantified using fluorescence detection. Initial cell-free experiments with potassium superoxide and xanthine oxidase confirmed the formation of oxyethidium from dihydroethidium. The formation of oxyethidium was inhibited by superoxide dismutase but not catalase and did not occur upon the addition of H(2)O(2), peroxynitrite, or hypochlorous acid. In bovine aortic endothelial cells (BAEC) and murine aortas, the redox cycling drug menadione increased the formation of oxyethidium from dihydroethidium ninefold (0.4 nmol/mg in control vs. 3.6 nmol/mg with 20 microM menadione), and polyethylene glycol-conjugated superoxide dismutase (PEG-SOD) significantly inhibited this effect. Treatment of BAEC with angiotensin II caused a twofold increase in oxyethidium formation, and this effect also was reduced by PEG-SOD (0.5 nmol/mg). In addition, in the aortas of mice with angiotensin II-induced hypertension and DOCA-salt hypertension, the formation of oxyethidium was increased in a manner corresponding to superoxide production estimated on the basis of cytochrome c reduction. Detection of oxyethidium using HPLC represents a new, convenient, quantitative method for the detection of superoxide in intact cells and tissues.
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PMID:Detection of intracellular superoxide formation in endothelial cells and intact tissues using dihydroethidium and an HPLC-based assay. 1530 39

Very little is known regarding the mechanisms of action of angiotensin II (Ang II) or the consequences of Ang II-dependent hypertension in the cerebral circulation. We tested the hypothesis that Ang II produces constriction of cerebral arteries that is mediated by activation of AT1A receptors and Rho-kinase. Basilar arteries (baseline diameter approximately 130 microm) from mice were isolated, cannulated and pressurized to measure the vessel diameter. Angiotensin II was a potent constrictor in arteries from male, but not female, mice. Vasoconstriction in response to Ang II was prevented by an inhibitor of Rho-kinase (Y-27632) in control mice, and was reduced by approximately 85% in mice deficient in expression of AT1A receptors. We also examined the chronic effects of Ang II using a model of Ang II-dependent hypertension, mice which overexpress human renin (R+) and angiotensinogen (A+). Responses to the endothelium-dependent agonist acetylcholine were markedly impaired in R+A+ mice (P<0.01) compared with controls, but were restored to normal by a superoxide scavenger (PEG-SOD). A-23187 (another endothelium-dependent agonist) produced vasodilation in control mice, but no response or vasoconstriction in R+A+ mice. In contrast, dilation of the basilar artery in response to a NO donor (NONOate) was similar in R+A+ mice and controls. Thus, Ang II produces potent constriction of cerebral arteries via activation of AT1A receptors and Rho-kinase. There are marked gender differences in cerebral vascular responses to Ang II. Endothelial function is greatly impaired in a genetic model of Ang II-dependent hypertension via a mechanism that involves superoxide.
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PMID:Cerebral vascular effects of angiotensin II: new insights from genetic models. 1609 17


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