Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0030567 (Parkinson's disease)
63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During the period from July 1995 to June 1996 we performed transurethral resection of the prostate (TURP) on 824 patients with benign prostatic hyperplasia (BPH). Among them, 13 were dementia patients between 74 and 96 years old; they presented with urinary hesitancy in 6, retention in 4, frequency in 2 and incontinence in 1 patient. Past history included stroke in 7, hypertension in 6, pulmonary tuberculosis in 4, diabetes in 3, asthma in 2, angina pectoris in 1, Parkinson's disease in 1, pneumonia in 1, and hepatitis in 1. Careful preoperative examination revealed that they were proper candidates for TURP. They underwent TURP under spinal anesthesia. The mean operative time was 34 min, ranging from 20 to 60 min. The adenoma resected weighed 24 g on the average, ranging from 7.5 to 48 g. During surgery, although hypotension was noted in 2 patients, there was no serious morbidity. Their mental condition was well controlled with ketamine and diazepam during and after surgery. Postoperative complications included acute myocardial infarction in 1, multiple gastric ulcer in 1, and decubitus in 1. None died within 3 months after TURP, 3 died there after, and 10 patients were alive at the mean follow-up period of 26 months. Six patients reported good urination, 3 reported some improvement in urination after surgery, although requiring intermittent catheterization and 1 developed mild incontinence. In conclusion, TURP appears to provide some benefit in selected patients with dementia and should not be considered to be a contraindication for such patients.
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PMID:[Transurethral resection of the prostate for patients with dementia]. 1036 42

Catechol-O-methyltransferase (COMT, EC 2.1.1.6) is a ubiquitous enzyme that is crucial to the metabolism of carcinogenic catechols and catecholamines. Regulation of human COMT gene expression may be important in the pathophysiology of various human disorders including estrogen-induced cancers, Parkinson's disease, depression, and hypertension. The gender difference in human COMT activity and variations in rat COMT activity during the estrous cycle led us to explore whether estrogen can regulate human COMT gene transcription. Our Northern analyses showed that physiological concentrations of 17-beta-estradiol (10(-9)-10(-7) M) could decrease human 1. 3-kilobase COMT mRNA levels in MCF-7 cells in a time- and dose-dependent manner through an estrogen receptor-dependent mechanism. Two DNA fragments immediately 5' to the published human COMT gene proximal and distal promoters were cloned. Sequence analyses revealed several half-palindromic estrogen response elements and CCAAT/enhancer binding protein sites. By cotransfecting COMT promoter-chloramphenicol acetyltransferase reporter genes with human estrogen receptor cDNA and pSV-beta-galactosidase plasmids into COS-7 cells, we showed that 17-beta-estradiol could down-regulate chloramphenicol acetyltransferase activities, and COMT promoter activities dose-dependently. Functional deletion analyses of COMT promoters also showed that this estrogenic effect was mediated by a 280 base pair fragment with two putative half-palindromic estrogen response elements in the proximal promoter and a 323-base pair fragment with two putative CCAAT/enhancer binding protein sites in the distal promoter. Our findings provide the first evidence and molecular mechanism for estrogen to inhibit COMT gene transcription, which may shed new insight into the role of estrogen in the pathophysiology of different human disorders.
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PMID:Characterization and implications of estrogenic down-regulation of human catechol-O-methyltransferase gene transcription. 1038 81

This article reviews evidence for the occurrence of atypical parkinsonism in Afro-Caribbean and Indian ethnic minority subjects living in western countries, particularly the UK. Current information on the frequency, pattern, and prevalence of Parkinson's disease and parkinsonism in these communities is unclear and controversial. While several workers have suggested that there is a low prevalence of Parkinson's disease in populations of African origin, other workers have suggested a higher prevalence of Parkinson's disease in African Americans. Furthermore, little information is available in relation to the pattern of parkinsonism in these subjects. A recent phenomenologic study of parkinsonism in the French West Indies by Caparros-Lefebvre and colleagues has indicated a significantly increased frequency of atypical parkinsonism in local non-white subjects. Since 1995, we have been studying the pattern and frequency of parkinsonism in Afro-Caribbean and Indian (originating from the Indian subcontinent) patients living in the UK, with London serving as the coordinating center. Our results indicate that there is a three- to fourfold increase in the frequency of occurrence of sporadic atypical parkinsonism characterized by levodopa hyporesponsiveness, bradykinesia-dominant disease, and early cognitive dysfunction in these patients even after exclusion of patients with clinically probable multiple system atrophy, progressive supranuclear palsy, and Lewy body dementia. These findings are similar to observations made in the French West Indies. Ongoing studies in India suggest that atypical parkinsonism also affects local patients, and the pattern of parkinsonism tends to differ from Afro-Caribbean subjects in the UK. Studies are currently underway to unravel the mechanism of increased frequency of atypical parkinsonism in these ethnic groups and include genetic studies addressing polymorphisms of enzymes metabolizing levodopa, dietary neurotoxin screen and functional imaging studies of the striatum using positron emission tomography. Furthermore, the contribution of diabetes mellitus and hypertension, commonly seen in these ethnic groups, is also being examined.
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PMID:Atypical parkinsonism in Afro-Caribbean and Indian origin immigrants to the UK. 1063 37

The plasma soluble melanins (PSM) form spontaneously in vitro and in vivo and their formation involves oxidative polymerization and copolymerization of dopa, catecholamines, homogentisic acid, 3-hydroxyanthranilic acid, p-aminophenol, p-phenylenediamine, and other end(ex)ogenous ortho and para polyhydroxy-, (poly)hydroxy(poly)amino- and polyamino-phenyl compounds. The build up of PSM is visible within 2-3 h after the start of incubation at 37 degrees C with 1 mg/ml of plasma. PSM also form similarly in blood and these processes cause hemolysis. The mean quantity of PSM in normal human plasma is 1.61+/-0.1 (S.D.) mg/ml (n = 20) and in normal human urine is 1.1+/-1.2 g/24 h collection (n = 8). They contribute to the yellow color of plasma and urine. Antioxidants delay the formation of PSM. The deposited melanins also form from these precursors. Reactive oxygen side products (ROSP) are generated during and after melanogenesis. Melanins in vivo are generally associated with proteins or with proteins and lipids. The PSM-protein-lipid complexes are called plasma soluble lipofuscins (PSL), because they have histochemical and fluorescence properties similar to those of solid lipofuscins. The soluble and deposited melanins (SDM) and their intermediates have similar toxic chemical reactivities. The oxidizing quinoid (they can produce partially and completely substituted conjugates) and the semiquinoid free radical intermediates are also moieties in most human melanin structures. Soluble melanins formed from dopa, or dopamine, or norepinephrine in weak alkaline solution have been shown to be toxic to human CD4+ lymphoblastic cells (MT-2) at higher than 10 microg/ml concentrations. Alkaptonuria with high levels of homogentisic acid in the plasma is a potentially fatal disease, exhibiting the toxic effects of the homogentisic acid melanin (soluble and deposited), its intermediates and the ROSP. Patients with alkaptonuria develop arthritis and often suffer from other diseases too, including cardiovascular disease (frequent cause of death) and kidney disease. Pheochromocytoma, with high levels of catecholamines in the plasma is another potentially fatal disease. The catecholamine PSM of pheochromocytoma have very light yellow or practically no colors, due to the concentrations and chemical structures. Pheochromocytomas can cause hypertension, cardiovascular disease (frequent cause of death), kidney disease, stroke, cancer, amyloid formation and can mimic many other diseases, including acute pancreatitis, carcinoid, neuroblastoma, psychiatric illness, hypercalcemia, retinal vascular lesions, and diabetes mellitus. Pheochromocytoma is potentially fatal even in patients without hypertension. Following trauma and surgery, heavily pigmented eyes are apt to experience greater inflammation than lightly pigmented eyes. In Parkinson's disease those neurons are lost first in the substantia nigra and locus ceruleus which contain the greatest amounts of neuromelanins. The antihypertensive alphamethyldopa causes Parkinson's syndrome. It forms PSM in a short time in vitro. The side effects of L-dopa (immobility episodes alternate with normal or involuntary movements; psychotic abnormalities) suggest that the SDM, their intermediates and the ROSP present naturally in vivo are involved in the cause of Parkinson's disease and Alzheimer's disease. There is a large overlap between these two diseases. (ABSTRACT TRUNCATED)
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PMID:The probable involvement of soluble and deposited melanins, their intermediates and the reactive oxygen side-products in human diseases and aging. 1124 35

The brain, as an intensely active organ, is highly dependent on a sufficient nutrient and oxygen availability in order to reach its optimal working capacity. It is well known that the vital supply of energy substrates is provided by the circulatory system, which splits up into a fine, terminal capillary network in target tissues. These capillaries are considered as important sites, since the actual nutrient trafficking takes place through their walls. That is why an intact, preserved structure of the microvessels is crucial to fulfill their function. Since the brain is known to be particularly vulnerable to suboptimal oxygen and glucose delivery, the intact morphology of capillaries is of paramount importance. Several observations have indicated that the cerebral capillary ultrastructure is damaged in Alzheimer's disease (AD). Curiously, the regional cerebral blood flow of AD patients is also significantly lower than in age-matched control individuals. Based on these data, it has been suggested that the decreased blood supply and the cerebrovascular alterations contribute to the development of dementia. However, we have observed similar capillary damage in Parkinson's disease patients and chronically hypertensive rats in addition to AD cases, as presented here. These findings indicate that cerebral capillary damage is not exclusive for AD but occurs under other neurodegenerative disorders and hypertension, as well. We hypothesize that ultrastructural abnormalities of cerebral capillaries are causally related to decreased cerebral blood flow and create a condition that favors neurodegenerative mechanisms including the development of dementia.
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PMID:Similar ultrastructural breakdown of cerebrocortical capillaries in Alzheimer's disease, Parkinson's disease, and experimental hypertension. What is the functional link? 1081 91

Catechol-O-methyltransferase (COMT) catalyses the O-methylation of neurotransmitters, catechol hormones and drugs such as levodopa and methyldopa. Ethnic differences in COMT activity have been observed in several populations. Previous studies suggest that the g1947G>A low activity allele is less common in individuals of African origin. COMT genotyping was performed using a mini-sequencing method in 195 healthy Ghanaians with a frequency of the homozygous g1947G>A of 6%. This study provides confirmation that the low activity COMT allele is less common in individuals of African origin. This finding may be important clinically with regards to the treatment of many neuropsychiatric disorders and in the pathophysiology of various human disorders including estrogen-induced cancers, Parkinson's disease, depression and hypertension.
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PMID:Pharmacogenetics of catechol-O-methyltransferase: frequency of low activity allele in a Ghanaian population. 1105 6

The present pharmacoepidemiologic study was performed to characterize the profile of adverse drug reactions (ADRs) reported with selegiline, a monoamine oxidase B (MAO-B) inhibitor used in the treatment of Parkinson's disease and previously reported to induce an excess of mortality. The analysis was performed with use of the French Pharmacovigilance Database between 1989 and 1997. This database includes all ADRs reported by French practitioners (and especially "serious" and "unexpected" ADRs). Three different analyses were performed: identification of ADRs reported with selegiline, comparison with the ADR profile observed with other antiparkinsonian drugs, and a case/non-case study investigating the occurrence of cardiovascular ADRs with selegiline in comparison with other drugs in general and other antiparkinsonian drugs (e.g., levodopa [L-Dopa], dopamine agonists) in particular. The most often reported ADRs with selegiline were psychiatric (delirium, hallucinations, agitations), cardiovascular (orthostatic hypotension, arterial hypertension, etc.) and neurologic (sedation, abnormal movements, etc.). Psychiatric and cardiovascular ADRs were more frequently reported with selegiline than with L-Dopa or dopamine agonists. The case/ non-case study found an increased risk of cardiovascular ADRs (OR = 1.72; 95% Cl = 1.16-2.55)when selegiline was associated with L-Dopa. These data show that the profile of selegiline-induced ADRs differs from that of other antiparkinsonian drugs (L-Dopa, dopamine agonists) with more psychiatric and cardiovascular ADRs. We suggest that the higher frequency of cardiovascular ADRs could explain, at least partially, the previously reported increase in mortality rate.
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PMID:Adverse drug reactions to selegiline: a review of the French pharmacovigilance database. 1115 95

We studied the neurological comorbidity of parkinsonism in 368 consecutive patients from the Lausanne Movement Disorders Registry. Only 6 patients had no neurological comorbidity. We found that 23p.100 of our patients had ischemic strokes, especially large vessel strokes, i.e three times more than in an age-matched control study performed in a recent survey in our country, which is a new finding in contradiction with previous reports mentioning that Parkinson's disease may be a protective factor against stroke. This finding opens new directions for further studies concerning some shared mechanisms in both diseases associated with age. Predominantly tremulous parkinsonism (46p.100) and progressive supranuclear palsy patients (PSP) (40p.100) had the highest prevalence of cerebrovascular disease of all subgroups of parkinsonism, especially lacunar infarcts, which is in accord with a higher frequency of hypertension in these subgroups according to a recent study of ours. Transient ischemic attacks or hemorrhages were not more frequent than in the general population. We did not find a higher frequency of head trauma except for Parkinson's disease, but a trend for a higher frequency of headache and migraine. Brain tumors were more frequent in Parkinson's disease and hydrocephalus and radiculopathies in parkinsonism in general when compared to age-matched populations from the literature. Polyneuropathies were more frequently observed in familial parkinsonism only, but myopathies and cranial neuropathies were not more frequent in our patients. Epilepsy was significantly less frequent in parkinsonism, especially in Parkinson's disease, infectious diseases of the nervous system were rarely encountered, and restless legs syndrome was surprisingly not more frequent than in a normal population. Dementia was associated in 20p.100, but multiple sclerosis is noticeably absent.
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PMID:[Neurological comorbidity in parkinsonism]. 1124 May 47

The authors evaluated the prevalence of dementia in centenarians. In this population-based survey, persons living in Denmark who turned 100 during the period April 1, 1995--May 31, 1996 (N = 276) were interviewed and examined at their residences. Additional health information was retrieved from medical files, including the National Discharge Registry. A participation rate was 75%, and no differences were found between participants and nonparticipants regarding sex and type of housing. The prevalence of mild to severe dementia in centenarians was 51%; 37% had no signs of dementia. Among the 105 demented centenarians, 13 (12%) had diseases (vitamin B12 and folic acid deficiencies, hypothyroidism, Parkinson's disease) that could contribute to a dementia diagnosis. Of the remaining 92 demented participants, 46 (50%) had 1 one or more cerebro- or cardiovascular diseases known to be risk factors in the development of dementia. The prevalence of these risk factors was the same in demented and nondemented participants, whereas hypertension was significantly more frequent in nondemented than demented participants. Dementia is common but not inevitable in centenarians. Cerebro- and cardiovascular diseases are equally common in demented and nondemented persons.
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PMID:Dementia is not inevitable: a population-based study of Danish centenarians. 1131 33

The total and regional peripheral resistance and capacitance of the vascular system is regulated by the sympathetic nervous system, which influences the vasculature mainly through changes in the release of catecholamines from both the sympathetic nerve terminals and the adrenal medulla. The knowledge of the targets for noradrenaline and adrenaline, the main endogenous catecholamines mediating that influence, has recently been greatly expanded. From two types of adrenoceptors (alpha and beta), we have now nine subtypes (alpha1A, alpha1B, alpha1D, alpha2A/D, alpha2B, alpha2A/D, beta1, beta2, and beta3) and two other candidates (alpha1L and beta4), which may be conformational states of alpha1A and beta1-adrenoceptors, respectively. The vascular endothelium is now known to be more than a pure anatomical entity, which smoothly contacts the blood and forms a passive barrier against plasma lipids. Instead, the endothelium is an important organ possessing at least five different adrenoceptor subtypes (alpha2A/D, alpha2C, beta1, beta2, and beta3), which either directly or through the release of nitric oxide actively participate in the regulation of the vascular tone. The availability of transgenic models has resulted in a stepwise progression toward the identification of the role of each adrenoceptor subtype in the regulation of blood pressure and fine-tuning of blood supply to the different organs: alpha2A/D-adrenoceptors are involved in the central control of blood pressure; alpha1-(primarily) and alpha2B-adrenoceptors (secondarily) contribute to the peripheral regulation of vascular tone; and alpha2A/D- and alpha2C-adrenoceptors modulate transmitter release. The increased knowledge on the involvement of vascular adrenoceptors in many diseases like Raynaud's, scleroderma, several neurological degenerative diseases (familial amyloidotic polyneuropathy, Parkinson disease, multiple-system atrophy), some kinds of hypertension, etc., will contribute to new and better therapeutic approaches.
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PMID:Vascular adrenoceptors: an update. 1135 87


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