Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Most of the current concepts on morphogenesis of atherosclerosis attribute the development of atherosclerotic lesions to the combined effects of two main cellular events: 1) activation of macrophages leading to lipoprotein phagocytosis by scavenger cells, and 2) proliferation of smooth muscle cells (SMC). SMC-like cells producing collagenous fibers and extracellular matrix are particularly involved in the formation of the so-called fibrous caps surrounding the core of an atheroma composed of foam cells and fatty debris. The fiber-forming SMC, in general, are said to result from a proliferation of media SMC which once have moved into the intima. This view of origin of the fiber-forming SMC and the alleged proliferation of media SMC is mainly derived from experimental assays exposing the vessel wall to various kinds of physical or chemical injuries. It is the purpose of this paper to demonstrate that the results of those more or less ephemeral experiments differ from findings obtained from a combined histochemical and morphometric analysis of SMC in the aortic media in spontaneous human arteriosclerosis. Instead of any proliferation, a significant atrophy of SMC occurs in the media with advancing age and progress of atherosclerosis. To some extent, this decrease in numerical and volumetric density of SMC is accompanied with intra- and extracellular calcification. It seems likely that the loss of contractile capacity of the media resulting from wasting of SMC, does slow down the stream of the interstitial fluid in the arterial wall. This stagnation must increase the life span of LDL moving through the interstitial space. The chemical alteration ensuing from aging of LDL mediates its binding to the scavenger receptors and uptake by macrophages. So far, muscular atrophy of the media forms an atherogenic factor of its own, leading to final results similar to those as known from conditions of intravascular aging of LDL in hyperlipoproteinaemia. The augmentation of SMC-like cells in the intima is hardly to be derived from the atrophic media, but rather seems to be due to local proliferation of cells which, in the normal state, do occur in small numbers in the subendothelial space. These so-called myointimal or Langhans-cells share with SMC their content of alpha-actin, but they differ by their stellate configuration from the bipolar shape SMC of the media.
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PMID:Proliferation versus atrophy--the ambivalent role of smooth muscle cells in human atherosclerosis. 794 76

Malnutrition and hypoalbuminemia, which are prevalent in patients with end-stage renal disease (ESRD), are strong predictors of increased mortality. However, cardiovascular disease predominates among direct causes of death, whereas malnutrition appears to be of minor importance in this respect. Reports in the literature demonstrate that cardiac failure may cause malnutrition and that infection/inflammation may predispose to atherosclerosis as well as to catabolism and hypoalbuminemia. Proinflammatory cytokines, generated in response to cardiac failure, infection, and other inflammatory stimuli, appear to play a pivotal role by causing muscle wasting, hypoalbuminemia, and anorexia as well as reduced cardiac contractility and atherosclerotic vascular disease. We hypothesize that this scenario also applies to ESRD patients, in whom congestion, hypertension, cardiac failure, and ischemic cardiovascular disease are common. Malnutrition rarely may be the direct cause of death, except in elderly dialysis patients, but may contribute to a poor prognosis by aggravating pre-existing heart failure and increasing the susceptibility to infections.
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PMID:Malnutrition, cardiac disease, and mortality: an integrated point of view. 982 Apr 57

Malnutrition, inflammation and atherosclerotic cardiovascular disease occur at high prevalence, and often concomitantly, in conjunction with chronic renal failure. Several features of malnutrition (e.g., increased oxidative stress, increased plasma levels of fibrinogen, Lp(a), and inflammation) may all, alone or in concert, increase the risk of cardiovascular disease. Recent findings suggest malnutrition and hypoalbuminaemia in chronic renal failure to be largely the consequence of such factors as heart failure, chronic infection and inflammation, that simultaneously trigger the development of atherosclerotic cardiovascular disease. Central to this scenario is the involvement of proinflammatory cytokines which may cause muscle wasting, hypoalbuminaemia, anorexia, and accelerated atherosclerosis. It is unlikely that the high mortality due to atherosclerotic disease among patients with chronic renal failure can be substantially reduced unless new treatment strategies are developed which address the complex relationships that exist between malnutrition, inflammation and cardiovascular disease.
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PMID:[Strong connection between malnutrition, inflammation and arteriosclerosis. Improved treatment of renal failure if underlying factors are attacked]. 1057 60

Penile erection is a vascular phenomenon that results from smooth muscle relaxation, arterial dilation and venous restriction. The atherosclerosis of the penis that occurs with aging causes a decrease in penile oxygen tension. A reduction of smooth muscle cells has been demonstrated in relation with this change in oxygen tension. Changes in the ratio of penile collagen have also been observed and could explain the decrease in penile elasticity and compliance. Chronic ischemia is, therefore, associated with fibrosis but also with nitric oxide (NO)-cyclic guanosine monophosphate. The sensitivity of the alpha-adrenoceptors on the smooth muscle cells increases with aging. All those modifications can explain the prevalence of erectile dysfunction with aging. Low oxygen tension in prostanoid production may also play a role in the mechanism of ischemia-induced cavernosal fibrosis; however, intracavernous injections of prostaglandin E(1) do not seem to modify the intracavernous structures by reducing muscular atrophy. The effects of androgen on libido and sexual behavior are well established, but their role in the human erectile mechanism remains unclear. Several studies performed on animals have demonstrated impacts directly on both the physiological function and the trabecular structure of the corpora cavernosa in rats, dogs and rabbits. However, in humans, no study seems to demonstrate a role of testosterone on muscular atrophy or penile neurologic control. Testosterone treatment alters the human behavior but not penile physiologic processes. Further studies are necessary to explain the real role of testosterone not only on the peripheral mechanism of erection but also on the central control.
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PMID:Smooth muscle pathology and erectile dysfunction. 1185 Jul 30

Diseases due to mutations in the lamin A/C gene (LMNA) are highly heterogeneous, including neuromuscular and cardiac dystrophies, lipodystrophies, and premature ageing syndromes. In this study we characterized the neuromuscular and cardiac phenotypes of patients bearing the heterozygous LMNA R482W mutation, which is the most frequent genotype associated with the familial partial lipodystrophy of the Dunnigan type (FPLD). Fourteen patients from two unrelated families, including 10 affected subjects, were studied. The two probands had been referred for lipoatrophy and/or diabetes. Lipodystrophy, exclusively observed in LMNA-mutated patients, was of variable severity and limited to postpubertal subjects. Lipodystrophy and metabolic disturbances were more severe in women, even if an enlarged neck was a constant finding. The severity of hypertriglyceridemia and hirsutism in females was related to that of insulin resistance. Clinical muscular alterations were only present in LMNA-mutated patients. Clinical and histological examination showed an invalidating, progressive limb-girdle muscular dystrophy in a 42-yr-old woman that had been present since childhood, associated with a typical postpubertal FPLD phenotype. Six of eight adults presented the association of calf hypertrophy, perihumeral muscular atrophy, and a rolling gait due to proximal lower limb weakness. Muscular histology was compatible with muscular dystrophy in one of them and/or showed a nonspecific excess of lipid droplets (in three cases). Immunostaining of lamin A/C was normal in the six muscular biopsies. Surprisingly, calpain 3 expression was undetectable in the patient with the severe limb-girdle muscular dystrophy, although the gene did not reveal any molecular alterations. At the cardiac level, cardiac septal hypertrophy and atherosclerosis were frequent in FPLD patients. In addition, a 24-yr-old FPLD patient had a symptomatic second degree atrioventricular block. In conclusion, we showed that most lipodystrophic patients affected by the FPLD-linked LMNA R482W mutation show muscular and cardiac abnormalities. The occurrence and severity of the myopathic and lipoatrophic phenotypes varied and were not related. The muscular phenotype was evocative of limb girdle muscular dystrophy. Cardiac hypertrophy and advanced atherosclerosis were frequent. FPLD patients should receive careful neuromuscular and cardiac examination whatever the underlying LMNA mutation.
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PMID:Patients with familial partial lipodystrophy of the Dunnigan type due to a LMNA R482W mutation show muscular and cardiac abnormalities. 1553 79

Fibroblast growth factor 23 null mice (Fgf-23-/-) have a short lifespan and show numerous biochemical and morphological features consistent with premature aging-like phenotypes, including kyphosis, severe muscle wasting, hypogonadism, osteopenia, emphysema, uncoordinated movement, T cell dysregulation, and atrophy of the intestinal villi, skin, thymus, and spleen. Furthermore, increased vitamin D activities in homozygous mutants are associated with severe atherosclerosis and widespread soft tissue calcifications; ablation of vitamin D activity from Fgf-23-/- mice, by genetically deleting the 1alpha(OH)ase gene, eliminates atherosclerosis and ectopic calcifications and significantly rescues premature aging-like features of Fgf-23-/- mice, resulting in prolonged survival of Fgf-23-/-/1alpha(OH)ase-/- double mutants. Our results indicate a novel role of Fgf-23 in developing premature aging-like features through regulating vitamin D homeostasis. Finally, our data support a new model of interactions among Fgf-23, vitamin D, and klotho, a gene described as being associated with premature aging process.
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PMID:Premature aging-like phenotype in fibroblast growth factor 23 null mice is a vitamin D-mediated process. 1643 65

Hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors represent the most successful class of drugs for the treatment of hypercholesterolaemia and dyslipidaemia implicated in the pathogenesis of coronary heart disease and atherosclerosis. However, the popular profile of statins in terms of efficacy has been maligned by its adverse events. The myotoxicity, ranging from mild myopathy to serious rhabdomyolysis, associated with HMG-CoA reductase inhibitors, during treatment of hypercholesterolaemia is of paramount importance. Rhabdomyolysis is a rare but idiosyncratic muscle wasting disorder of different etiologies. Statin-associated rhabdomyolysis causes skeletal muscle injury by self-perpetuating events leading to fatal irreversible renal damage through a series of biochemical reactions. Preferential distribution and action of statins in liver could be the key to minimise myotoxicity concerns. Hepato-specific distribution of statins is governed by various factors such as physicochemical properties, pharmacokinetic properties and selective transporter-mediated uptake in liver rather in extrahepatic cells. The interactions of statins with concomitant drugs of different classes merit attention for their safety profile. Although pharmacokinetic as well as pharmacodynamic interactions have been implicated in pathophysiology of statin-induced muscle wasting, the underlying mechanism is not clearly understood. Besides, pharmacokinetic and phramcodynamic factors, statin-associated myotoxcity may also implicate pharmacogenomic factors. The pharmacogenomics characterised by CYP polymorphism and other genetic factors is responsible for inter-individual variations to efficacy and tolerability of statins. The pathophysiological mechanisms may include statin-induced differences in cholesterol:phospholipid ratio, isoprenoid levels, small GTP binding proteins and apoptosis. However, the present understanding of pathophysiological mechanisms, does not offer a reliable approach to address the same at preclinical level. Although statin-associated myotoxicity affects compliance, quality of life of patient and discontinuation rate, yet the low incidence of myotoxicty including rhabdomyolysis and less severity of commonly occurring myopathy and myalgia do not raise doubts about the clinical efficacy and tolerability of statins. Medical management of myotoxicity seems to be pivotal for the proper compliance of patients with statin treatment. The appropriate and judicious use of drugs would substantially reduce the likelihood of developing clinically important myopathy.
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PMID:Statins and myotoxicity: a therapeutic limitation. 1690 55

Cockayne syndrome and xeroderma pigmentosum-Cockayne syndrome complex are rare autosomal recessive disorders with poorly understood biology. They are characterized by profound postnatal brain and somatic growth failure and by degeneration of multiple tissues resulting in cachexia, dementia, and premature aging. They result in premature death, usually in childhood, exceptionally in adults. This study compares the clinical course and pathology of a man with Cockayne syndrome group A who died at age 31(1/2) years with 15 adequately documented other adults with Cockayne syndrome and 5 with xeroderma pigmentosum-Cockayne syndrome complex. Slowing of head and somatic growth was apparent before age 2 years, mental retardation and slowly progressive spasticity at 4 years, ataxia and hearing loss at 9 years, visual impairment at 14 years, typical Cockayne facies at 17 years, and cachexia and dementia in his twenties, with a retained outgoing personality. He experienced several transient right and left hemipareses and two episodes of status epilepticus following falls. Neuropathology disclosed profound microencephaly, bilateral old subdural hematomas, white-matter atrophy, tigroid leukodystrophy with string vessels, oligodendrocyte proliferation, bizarre reactive astrocytes, multifocal dystrophic calcification that was most marked in the basal ganglia, advanced atherosclerosis, mixed demyelinating and axonal neuropathy, and neurogenic muscular atrophy. Cellular degeneration of the organ of Corti, spiral and vestibular ganglia, and all chambers of the eye was severe. Rarely, and for unexplained reasons, in some patients with Cockayne syndrome the course is slower than usual, resulting in survival into adulthood. The profound dwarfing, failure of brain growth, cachexia, selectivity of tissue degeneration, and poor correlation between genotypes and phenotypes are not understood. Deficient repair of DNA can increase vulnerability to oxidative stress and play a role in the premature aging, but why patients with mutations in xeroderma pigmentosum genes present with the Cockayne syndrome phenotype is still not known.
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PMID:Cockayne syndrome in adults: review with clinical and pathologic study of a new case. 1709 72

Suitable mammalian models for aging with a wide range of age-associated pathology are desirable to study molecular mechanisms of human aging. Recent studies have identified that fibroblast growth factor 23 (Fgf-23) null mice and klotho hypomorphs could generate multiple premature aging-like features, including shortened lifespan, infertility, kyphosis, atherosclerosis, extensive soft tissue calcifications, skin atrophy, muscle wasting, T cell dysregulation, pulmonary emphysema, osteoporosis/osteopenia, abnormal mineral ion metabolism, and impaired vitamin-D homeostasis. The strikingly similar in vivo phenotypes of two separate genetically altered mouse lines implicate that the premature aging-like features may be partly regulated through a common signaling pathway involving both Fgf-23 and klotho; such speculation is experimentally supported by the observation that Fgf-23 requires klotho as a cofactor to exert its functions. Despite about 2000-fold higher serum levels of Fgf-23 in klotho mutants (compared to wild-type animals), these mice show physical, biochemical and morphological features similar to Fgf-23 null mice, but not as Fgf-23 transgenic mice; these observations suggest that widely encountered premature aging-like features in klotho mutant mice are due to the inability of Fgf-23 to exert its bioactivities in absence of klotho. The results of recent studies showing klotho as a cofactor in Fgf-23 signaling consequently explains that the premature aging-like features in klotho-deficient mice is not a primary cause, rather a consequence of lacking Fgf-23 activity. These understandings will help us to redefine the role of klotho as an aging factor.
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PMID:Premature aging in klotho mutant mice: cause or consequence? 1735 53

Protein-energy malnutrition with muscle wasting occurs in a large proportion of patients with chronic renal failure and is, in addition to atherosclerosis, a strong risk factor for cardiovascular mortality in dialysis patients. There is evidence that a chronic inflammation with activation of C-reactive protein and proinfalammatory cytokines is associated with increased oxidative stress and endothelial dysfunction. Strong relations between malnutrition, inflammation and atherosclerosis in dialysis patients suggest the presence of a MIA (malnutrition, inflammation and atherosclerosis) syndrome, which is associated with high mortality rate. Thus, it could be speculated that suppression of the vicious cycle of malnutrition, inflammation and atherosclerosis would improve survival in dialysis patients.
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PMID:Malnutrition, inflammation, atherosclerosis in hemodialysis patients. 1771 Oct 95


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