Is demodex really non-pathogenic?

Although usually considered a non-pathogenic parasite in parasitological textbooks, Demodex folliculorum has been implicated as a causative agent for some dermatological conditions, such as rosacea-like eruptions and some types of blepharitis. Several anecdotal reports have demonstrated unequivocal tissue damage directly related to the presence of the parasite. However, this seems to be exceedingly rare, in contrast with the marked prevalence of this infestation. We have had the opportunity to observe one of such cases. A 38-year-old woman presented with rosacea-like papular lesions in her right cheek. Histopathological examination revealed granulomatous dermal inflammation with a well-preserved mite phagocytized by a multinucleated giant cell. This finding may be taken as an evidence for the pathogenicity of the parasite, inasmuch as it does not explain how such a common parasite is able to produce such a rare disease.     

Is hypertension a prothrombotic state?

Hypertension is complicated by thrombosis-related events (such as myocardial infarction and stroke), and despite the high vascular pressures, these thrombotic occlusive events paradoxically occur more often than hemorrhagic episodes. The predisposition for thrombogenesis is increased in hypertension, which leads to changes in the platelets, endothelium, and matrix metalloproteinases and their inhibitors, as well as the coagulation and fibrinolytic pathways, which help promote the induction and the maintenance of this prothrombotic or hypercoagulable state. Other cardiovascular diseases, such as atrial fibrillation, congestive heart failure, and left ventricular hypertrophy, which may occur as a result of untreated hypertension, can also activate the prothrombotic state. These changes can, to a certain degree, be reversed by the treatment of hypertension, although the effects may be inconsistent. The evidence for antithrombotic therapy is less consistent, but in "high risk" hypertensive patients, antiplatelet therapy is useful.     

Is hypertension an immunologic disease?

Several studies published in the past three decades have suggested that the adaptive immune system contributes to hypertension. Recent studies have shown that T cells play a crucial role in the blood pressure elevation caused by angiotensin II and in response to sodium and volume challenge. Hypertensive stimuli cause effector T cells to enter visceral fat, in particular perivascular fat, where they release cytokines that promote vasoconstriction. Similarly, effector T cells accumulate in the kidney in hypertension and contribute to renal dysfunction, promoting sodium and volume retention. These findings provide some insight into the relationship between inflammation and hypertension and suggest that efforts to reduce T-cell activation may be useful in preventing or treating this disease.     

Is there ileopathy in portal hypertension?

BACKGROUND AND AIMS: Portal hypertensive gastropathy and colopathy are well described endoscopic abnormalities in patients with portal hypertension. Endoscopic abnormalities in the ileum in patients with portal hypertension have not been well described. The aim of the present study was to evaluate endoscopic abnormalities in the ileum of patients with portal hypertension. METHODS: Patients with portal hypertension of various etiologies were included in the study. Upper gastrointestinal endoscopy was performed to record esophageal varices, gastric varices and portal hypertensive gastropathy. Colonoscopy with retrograde intubation of the ileum was performed and the presence of colorectal varices, colopathy and mucosal findings in the ileum were noted. RESULTS: Forty-one patients (age 16-80 years, 33 men) were studied. Esophageal varices were present in all. Portal hypertensive gastropathy was present in 27/41 (66%) patients. Rectal varices were noted in 22/41 (54%) patients and 17/41 (42%) patients had features suggestive of colopathy. Ileum could be intubated in 38 patients (93%). Endoscopic abnormalities in the ileum were noted in 13/38 (34%) patients. Ileopathy as evident by endoscopic mucosal abnormalities was observed in 10/38 (26%) patients. Ileal varices were present in 8/38 (21%) patients. Three of these had ileal varices alone while the remaining five patients also had associated ileopathy The presence of ileopathy was significantly associated with the presence of portal hypertensive gastropathy and colopathy but not with esophageal, gastric or rectal varices. CONCLUSIONS: Ileopathy occurs in one-third of patients with portal hypertension and is significantly associated with the presence of portal hypertensive gastropathy and colopathy.     

What is the prevalence of resistant hypertension in the United States?

Purpose of review Resistant hypertension, defined as blood pressure uncontrolled on three, or controlled with at least four, antihypertensive agents (including a diuretic), is associated with higher risk of secondary hypertension, cardiovascular and renal events, and increased healthcare expenditures. Until recently, however, the prevalence of resistant hypertension in the United States (US) was based on clinical trial registries or pharmacy databases. Recent findings Recent analyses of National Health and Nutrition Examination Survey (NHANES) data, drawn from representative samples of the adult, noninstitutionalized, civilian population, have estimated the prevalence of resistant hypertension at 8.9 ± 0.6% of the US hypertensive population in 2003-2008. A time-sequence comparison of NHANES data from 1998 through 2008 suggests that, unlike hypertension, resistant hypertension is becoming more prevalent (e.g., 20.7% in 2005-2008), due to aging and increased obesity in the general population. Resistant hypertension was more frequent in people who were older, obese, male, African American or nonblack Hispanic. Summary In coming years, even if the prevalence of hypertension remains stable, resistant hypertension is likely to increase, especially as the proportion of treated hypertension increases. Because of increased use of healthcare resources, resistant hypertensive patients should be identified early, and greater efforts made to control their blood pressures.