Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine if there is a quantitative relationship between systolic contraction abnormalities (demonstrated by two-dimensional echocardiography) and reduced myocardial perfusion in a setting of moderate and severe coronary stenosis, we created 70% or 90% reduction in circumflex coronary artery diameter in open-chest dogs. Transient ischemia was induced by superimposing increased myocardial oxygen requirements (i.v. isoproterenol, aortic constriction) in the presence of the stenosis or by decreased coronary perfusion (lowering arterial pressure with i.v. nitroprusside, nitroglycerin, or hemorrhage). Acute systolic wall thinning show by two-dimensional echocardiography or by implanted myocardial sonomicrometers was taken as functional evidence of myocardial ischemia. Myocardial perfusion was determined by radiolabeled microspheres when wall thinning was apparent. Systolic wall thinning could not be induced by these interventions when the degree of coronary stenosis was only 70%. Systolic wall thinning occurred only when increased myocardial oxygen requirements or decreased aortic pressure were superimposed on 90% coronary stenosis. Under these conditions, myocardial perfusion was reduced to 28 +/- 27 ml/100 g/min (mean +/- SD), 15--25% of control. Aortic diastolic pressure was a major determinant of ischemia in that contraction abnormalities produced by a 90% stenosis and vasodilators or hemorrhage could be acutely reversed by superimposing acute aortic constriction, which elevated arterial pressure; myocardial perfusion increased correspondingly. Thus, the demonstration of transient systolic wall thinning by two-dimensional echocardiography during a stressful intervention indicated that severe coronary stenosis was present, and that the perfusion of the acutely dyskinetic myocardial area was 25% of control or less.
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PMID:Two-dimensional echocardiography in experimental coronary stenosis. II. Relationship between systolic wall thinning and regional myocardial perfusion in severe coronary stenosis. 680 69

We report a case of diffuse thinning of an inferior epigastric artery early after its implantation as a coronary free graft. This phenomenon showed reversibility at the 20-month angiographic follow-up in response to progression of the proximal lesion in the recipient coronary artery. Graft vasodilation in response to atrial pacing and nitroglycerin infusion at late angiography confirmed the vasomotor adaptability of this arterial conduit.
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PMID:"Thinning-down phenomenon" and vasomotor adaptability of the inferior epigastric artery graft. 773 33

The hypothesis that nitrates might effectively limit left ventricular remodeling and improve function after acute myocardial infarction has been tested in experimental and clinical models, with special attention to the pathophysiologic evolution of remodeling. In 1 clinical study, before the thrombolytic era, the effects of low-dose intravenous nitroglycerin infusion for the first 48 hours during acute myocardial infarction was evaluated in a prospective, randomized, single-blinded, placebo-controlled study of 310 patients (154 nitroglycerin; 156 placebo). Nitroglycerin proved to be safe and produced several benefits compared with placebo: (1) smaller infarct size; (2) less left ventricular dysfunction; (3) less infarct expansion and thinning; (4) better functional status; (5) fewer in-hospital complications such as left ventricular failure, left ventricular thrombus, cardiogenic shock, and infarct extension; and (6) fewer deaths up to 1 year. Two subsequent clinical studies in the thrombolytic era, with low-dose intravenous nitroglycerin infusion during infarction over the first 48 hours followed by buccal nitrate (eccentric dose regimen) or placebo during healing over 6 weeks postinfarction, indicated that prolonged nitrate therapy effectively limited left ventricular remodeling and improved function further compared with placebo.
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PMID:Effects of nitrate therapy on ventricular remodeling and function. 827 53

An historical background of the use of nitrates in the setting of acute myocardial infarction gives way to the successive steps this therapy gave in the last 15 years. The pioneer investigations of John Flaherty proving the usefulness of nitroglycerin in reducing infarct size followed by the works by Bussman and Jugdutt notably on the limitation of infarct size but also on the prevention of infarct expansion and ventricular wall thinning are reviewed. The adjunctive role of nitrates in thrombolytic therapy is appraised and its absolute and relative contraindications are pointed out. Finally and based on the statistical works by Yusuf, the real impact of nitrate therapy in mortality of acute myocardial infarction is emphasised.
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PMID:[Treatment of the acute phase of myocardial infarction with nitrates]. 849 17

Reperfusion alone during acute myocardial infarction (AMI) preserves left ventricular (LV) topography but causes 'stunning', with delayed or no recovery of function. To determine whether adjunctive intravenous nitroglycerin (NTG) accelerates functional recovery, we prospectively measured function and topography by repeated two-dimensional echocardiography between 1 day and 6 months in 5 groups of patients (n = 73) with a first AMI: placebo (group 1), NTG alone (group 2), NTG combined with successful reperfusion after 4 h (group 3) or failed reperfusion (group 4), and successful reperfusion alone (group 5). Asynergy decreased promptly (p < 0.001) and ejection fraction improved (p < 0.001) between day 1 and 6 months in groups 2 and 3 compared to baseline and groups 1, 4 and 5. Infarct expansion and thinning found in group 1 were prevented in groups 2, 3, 4 and 5. Diastolic volume increased in the anterior subgroup 1 but not 2, 3, 4 and 5. This is the first demonstration that reperfusion combined with adjunctive NTG produces earlier, greater and persistent recovery of LV function in addition to attenuation of remodeling in patients after AMI.
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PMID:Prompt improvement of left ventricular function and preservation of topography with combined reperfusion and intravenous nitroglycerin in acute myocardial infarction. 909 19

Bleeding from gastroesophageal varices is a frequent and often deadly complication of cirrhosis. The key factor in the natural history of esophageal varices is increased portal pressure, which in cirrhosis is due to the combination of increased hepatic vascular resistance and increased portal collateral blood flow. The maintenance and aggravation of this situation leads to the progressive dilation of the varices and thinning of the variceal wall, until the tension exerted by the variceal wall exceeds the elastic limit of the vessel, leading to variceal hemorrhage. Mortality from a variceal bleeding episode has decreased in the last two decades from 40% to 20% due to the implementation of effective treatments and improvement in the general medical care. Initial treatment should include adequate fluid resuscitation and transfusion to maintain the hematocrit at 25% to 30%, and prophylactic antibiotics (norfloxacin or amoxicillin-clavulanic acid). It is currently recommended that a vasoactive drug be started at the time of admission. Drug therapy may be started during transferal to hospital by medical or paramedical personnel and maintained for up to five days to prevent early rebleeding. Terlipressin, a vasopressin derivative, is the preferred agent because of its safety profile and proven efficacy in improving survival. Somatostatin is as effective as terlipressin, but may require higher than the usually recommended dosage. Octreotide is effective in conjunction with endoscopic therapy, but is the second choice because it has not been shown to reduce mortality. Vasopressin may be used where terlipressin is not available, but should be given in combination with transdermal nitroglycerin. Endoscopic elastic band ligation is the recommended endoscopic treatment, but injection sclerotherapy is still employed in many centres for active variceal bleeding. Failures of medical therapy (drugs plus endoscopic therapy) should undergo a second course of endoscopic therapy before proceeding to transjugular intrahepatic portosystemic shunt or, in rare occasions, to portosystemic shunt surgery. Administration of recombinant activated factor VII may decrease the number of treatment failures among patients with advanced liver failure (Child-Pugh class B and C).
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PMID:Medical management of variceal bleeding in patients with cirrhosis. 1499 22

We studied northern flying squirrel (Glaucomys sabrinus) demography in the eastern Washington Cascade Range to test hypotheses about regional and local abundance patterns and to inform managers of the possible effects of fire and fuels management on flying squirrels. We quantified habitat characteristics and squirrel density, population trends, and demography in three typical forest cover types over a four-year period. We had 2034 captures of flying squirrels over 41 000 trap nights from 1997 through 2000 and marked 879 squirrels for mark-recapture population analysis. Ponderosa pine (Pinus ponderosa) forest appeared to be poorer habitat for flying squirrels than young or mature mixed-conifer forest. About 35% fewer individuals were captured in open pine forest than in dry mixed-conifer Douglas-fir (Pseudotsuga menziesii) and grand fir (Abies grandis) forests. Home ranges were 85% larger in pine forest (4.6 ha) than in mixed-conifer forests (2.5 ha). Similarly, population density (Huggins estimator) in ponderosa pine forest was half (1.1 squirrels/ha) that of mixed-conifer forest (2.2 squirrels/ha). Tree canopy cover was the single best correlate of squirrel density (r = 0.77), with an apparent threshold of 55% canopy cover separating stands with low- from high-density populations. Pradel estimates of annual recruitment were lower in open pine (0.28) than in young (0.35) and mature (0.37) forest. High recruitment was most strongly associated with high understory plant species richness and truffle biomass. Annual survival rates ranged from 45% to 59% and did not vary among cover types. Survival was most strongly associated with understory species richness and forage lichen biomass. Maximum snow depth had a strong negative effect on survival. Rate of per capita increase showed a density-dependent response. Thinning and prescribed burning in ponderosa pine and dry mixed conifer forests to restore stable fire regimes and forest structure might reduce flying squirrel densities at stand levels by reducing forest canopy, woody debris, and the diversity or biomass of understory plants, truffles, and lichens. Those impacts might be ameliorated by patchy harvesting and the retention of large trees, woody debris, and mistletoe brooms. Negative stand-level impacts would be traded for increased resistance and resilience of dry-forest landscapes to now-common, large-scale stand replacement fires.
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PMID:Demography of northern flying squirrels informs ecosystem management of western interior forests. 1671 Oct 46

This study was performed to elucidate the relation between in vivo measurements of two-dimensional principal strains and the progression of left ventricle (LV) wall thinning during development of dilated cardiomyopathy in the protein kinase C-epsilon (PKC-epsilon) transgenic (TG) overexpressing mouse heart. Principal two-dimensional strains, E1 and E2, were determined in the LV wall of the anesthetized mouse using cardiac MRI tagging at 14.1 T. PKC-epsilon TG provided a model of pure dilated cardiomyopathy without evidence of hypertrophy (PKC-epsilon TG, n = 6). Ejection fraction, wall thickness, and principal strains were determined at 1-mo intervals in hearts of PKC-epsilon TG vs. age-matched, nontransgenic mice (NTG, n = 5) from age 6 to 13 mo. Through the study, PKC-epsilon TG displayed lower ejection fraction than NTG. At 7 mo, average principal strain E1 in PKC-epsilon TG hearts was lower compared with NTG (PKC-epsilon TG = 0.14 +/- 0.03, NTG = 0.19 +/- 0.03, P < 0.05). The greatest reductions in regional E1 occurred in the lateral segments. The principal strain E2 did not change significantly in either group. At 9 mo, LV wall thinning occurred in PKC-epsilon TG mice (P < 0.01 vs. 8 mo) to 21% below values in NTG (P < 0.001). Average E1 strain diverged between PKC-epsilon TG and NTG hearts by 25-43%. These E1 changes preceded LV wall thinning and predated the eventual transition from a compensated circumstance to the dilated phenotype. The findings indicate a near step function in E1 depression that precedes the onset of LV wall thinning and suggest E1 as a prognostic indicator of dilated cardiomyopathy.
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PMID:Principal strain changes precede ventricular wall thinning during transition to heart failure in a mouse model of dilated cardiomyopathy. 1796 77

Independent experimental and computational approaches show agreement concerning arginine/membrane interactions when a single arginine is introduced at selected positions within the membrane-spanning region of acetyl-GGALW(5)LALALAL(12)AL(14)ALALW(19)LAGA-ethanolamide, designated GWALP23. Peptide sequence isomers having Arg in position 12 or position 14 display markedly different behaviors, as deduced by both solid-state NMR experiments and coarse-grained molecular dynamics (CG-MD) simulations. With respect to the membrane normal of DOPC or DPPC lipid bilayer membranes, GWALP23-R14 shows one major state whose apparent average tilt is approximately 10 degrees greater than that of GWALP23. The presence of R14 furthermore induces bilayer thinning and peptide displacement to "lift" the charged guanidinium toward the bilayer surface. By contrast, GWALP23-R12 exhibits multiple states that are in slow exchange on the NMR time scale, with CG-MD simulations indicating two distinct positions with different screw rotation angles in the membrane, along with an increased tendency to exit the lipid bilayer.
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PMID:Changes in transmembrane helix alignment by arginine residues revealed by solid-state NMR experiments and coarse-grained MD simulations. 2037 35

Dear Editor, Cutaneous leiomyomas (CL) are rare, benign smooth muscle tumors of the skin (1). There are 3 subtypes with different origins and histopathologic features: piloleiomyoma, genital leiomyoma, and angioleiomyoma (2). Pilar leiomyoma is the most common subtype originating from arrector pili muscles of pilosebaceous unit. It presents as painful solitary or multiple papulonodules (2,3). A 30-year-old woman presented to our outpatient clinic with numerous painless, itchy papules on her gluteal region that had been present for 10 years. Dermatologic examination revealed red-brown, smooth, grouped papulonodules on bilateral gluteal regions (Figure 1). These lesions had appeared after intramuscular injections and had increased in number. Family history was unremarkable. A punch biopsy was performed with pre-diagnoses of keloid and tumoral infiltration. Histopathologic examination showed neoplastic infiltration with large bundles of spindle-like smooth muscle cells with acidophilic cytoplasm under epidermis (Figure 2). Neoplastic cells were stained by smooth muscle markers actin and caldesmon (Figure 3). Based on the clinical and histopathological findings the diagnosis of pilar leiomyoma was established. Pelvic and renal ultrasonographic examinations were normal. The patient's lesions were asymptomatic except for mild itching and she is currently in follow-up without any treatment. Pilar leiomyomas mostly manifest around the ages of 10 to 30 and are located on the trunk and extensor surfaces of the extremities. Lesions are firm, red-brown or skin-colored papulonodules with diameters varying from several mm to 2 cm (2). Differential diagnosis includes dermatofibroma, neurofibroma, smooth muscle hamartoma, neuroma, adnexal tumors, and painful papulonodular lesions such as glomus tumor (1,2). Our case clinically resembled keloid with red-brown, stiff nodules with epidermal thinning. In the literature, a patient with cutaneous pilar leiomyoma was diagnosed with eruptive keloid and treated with cryotherapy and intralesional steroid injections before histopathologic verification of pilar leiomyoma. He had multiple painless, red-purple papulonodules on the chest and arms (3). The case of a 53-year-old man with a history of multiple firm and painful lesions on the back showing segmental distribution and diagnosed with keloid-like leiomyoma was also reported (4). CL should be considered in the differential diagnosis of keloid-like lesions with atypical location and that are resistant to treatment. Cutaneous leiomyomas have different clinical presentations and many differential diagnoses, but CL can be diagnosed by histopathological examination. In all CLs, histopathologic examination shows bundles of spindle-shaped smooth muscle cells with eosinophilic cytoplasm, a cigarette-like nucleus, and a perinuclear halo. Smooth muscle markers actin and desmin are routinely positive. Histopathologic examination in our case also revealed bundles of spindle-like smooth muscle cells with large acidophilic cytoplasm; smooth muscle markers actin and caldesmon were positive. While solitary lesions are frequently sporadic cases, multiple lesions may be related to hereditary conditions such as Reed's syndrome (multiple cutaneous and uterine leiomyomatosis), hereditary leiomyomatosis, and renal cell cancer (2). These two hereditary conditions have been reported to be associated with a heterozygous germline mutation in fumarate hydratase gene (4). Our patient was considered a sporadic case due to lack of family history and uterine leiomyoma and normal renal ultrasonography. Treatment of CL depends on the number of lesions and presence of symptoms (1). Surgical excision is the gold standard in the treatment of solitary and self-limiting lesions (2). However, recurrence can be more commonly observed in patients with multiple lesions (1). Drugs targeting smooth muscle contraction such as nifedipine, nitroglycerin, and phenoxybenzamine are recommended for pain management. Methods such as cryotherapy and carbon dioxide laser ablation have been tested but their efficacy was found to be limited (1,2). In our patient, lesions were asymptomatic and few in number; we thus suggested follow-up without any treatment. CL are rare benign smooth muscle tumors of the skin. They are difficult to diagnose by clinical evaluation, but the diagnosis can be established by histopathologic examination. In patients with atypical keloid-like papulonodular lesions like our patient, pilar leiomyoma should be considered and histopathologic examination should be performed for the diagnosis.
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PMID:Cutaneous Leiomyoma Mimicking a Keloid. 3287 39


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