Vascular abnormalities

Yang LV, Radu CG, Roy M et al (2007) Vascular abnormalities in mice deficient for the G Protein-coupled receptor GPR4 that functions as a pH sensor. Mol Cell Biol 27 1334-1347... 

There is a long-standing hypothesis that the microvasculature plays a pathological role in forms of chronic inflammatory polyarthritis, particularly RA (Rothschild and Masi, 1982). One of the proposed mechanisms of vascular damage in connective tissue disease is the direct action of a cytotoxic serum factor inducing endothelial cell damage. Blake et al. (1985) have su ested that the vascular abnormalities associated with RA may be linked to oxidized lipoproteins because they are cytotoxic to endothelial cells. 

A relationship between polyol pathway activity and reduction in endothelium-dependent relaxation in aorta from chronic STZ-diabetic rats has recently been reported (Cameron and Cotter, 1992). In agreement with several previous studies (Oyama et al., 1986 Kamata et al., 1989), endothelial-dependent relaxation was defective in the diabetic rats but the deficit was prevented by prior treatment with an AR inhibitor. The mechanism underlying the defect has been speculated to be due to decreased production of endothelium-derived relaxing factor (EDRF) or nitric oxide, NO (Hattori et al., 1991). It has been speculated that these vascular abnormalities may lead to diminished blood flow in susceptible tissues and contribute to the development of some diabetic complications. NO is synthesized from the amino-acid L-arginine by a calcium-dependent NO synthase, which requires NADPH as a cofactor. Competition for NADPH from the polyol pathway would take place during times of sustained hyperglycaemia and... 

In advanced COPD, airflow obstruction, damaged bronchioles and alveoli, and pulmonary vascular abnormalities lead to impaired gas exchange. This results in hypoxemia and eventually hypercapnia. Hypoxemia is initially present only during exercise but occurs at rest as the disease progresses. Inequality in the ventilation/perfusion ratio (VAQ) is the major mechanism behind hypoxemia in COPD. 

In subarachnoid hemorrhage due to a ruptured intracranial aneurysm or arteriovenous malformation, surgical intervention to clip or ablate the vascular abnormality substantially reduces mortality from rebleeding. The benefits of surgery are less well documented in cases of primary intracerebral hemorrhage. In patients with intracerebral hematomas, insertion of an intraventricular drain with monitoring of intracranial pressure is... 

Macules are circumscribed, flat lesions of any shape or size that differ from surrounding skin because of their color. They may result from hyperpigmentation, hypopigmentation, vascular abnormalities, capillary dilatation (erythema), or purpura. 

Razani B, Engelman JA, Wang XB, Schubert W, Zhang XL, Marks CB, Macaluso F, Russell RG, Li M, Pestell RG, Di Vizio D, Hou H Jr, Kneitz B, Lagaud G, Christ GJ, Edelmann W, Lisanti MP (2001) Caveolin-1 null mice are viable but show evidence of hyperproliferative and vascular abnormalities. J Biol Chem 276(41 ) 38121-38138... 

Using flexible endoscopic catheters, intravascular fluorescence spectroscopy and imaging demonstrated that atherosclerotic plaques and other vascular abnormalities can be identified and characterized based either on endogenous fluorophores [11] or exogenous fluorescent dyes [146,147]. 

Indeed, your brain works so fast that you are always vulnerable to seizures in response to many different stimuli, such as a small head injury, a stroke, rapidly flashing lights, a tumor, vascular abnormalities, small hemorrhages, and so forth. Given the limitations of our brain physiology and chemistry, we are probably as smart as we possibly can be at this time in our species evolution. 

Noninvasive detection of vascular abnormalities is of the utmost importance in clinical imaging. Indeed, a lot of injuries and diseases manifest themselves through modifications of the vasculature [1,2]. For example, abnormal angiogenesis (blood vessel growth) is observed in the development of most tumors. Embolism and atherosclerosis also manifest themselves through alterations of the blood vessels, namely through occlusions. Hemorrhage could also be detected noninvasively, which is crucial in injuries or in diseases such as ulcers [1]. 

Several inherited connective tissue disorders predispose to arterial dissection and other vascular abnormalities, including aneurysms and vasoocclusive disease. 

Pretreatment features Facies, hypothermia None Treatment Hypothermia, failure to thrive, facies bone changes, vascular abnormalities, abnormal hair ... 

The introduction of fluorescein angiography in the early 1960s provided a useful method for studying various parameters of ocular function. Intravenous fluorescein is used extensively to delineate vascular abnormalities of the fundus and occasionally to evaluate anterior segment blood and aqueous flow. 

A 44-year-old man developed a severe headache and vomiting after taking four tablets of sildenafil (of unknown strength) followed by sexual intercourse (14). A CT scan showed a left-sided temporal intracranial hemorrhage. He died of cerebral edema and pneumonia a few days later. Autopsy showed no vascular abnormality. 

Depending upon its age, the tomographic density of hemorrhage is often sufficiently unique to identify hemorrhage as a major component of a lesion. Calcihcations and relationships with the skull are resolved well on CT. Gray and white matter, edema, and melanin are better seen on MRI. Vascular abnormalities are frequently dehned by MRA, or, if needed, angiographically. 

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