Abstract-Diets rich in fruits and vegetables reduce blood pressure (BP) and the risk of adverse cardiovascular events.However, the mechanisms of this effect have not been elucidated. Certain vegetables possess a high nitrate content, and we hypothesized that this might represent a source of vasoprotective nitric oxide via bioactivation. In healthy volunteers, approximately 3 hours after ingestion of a dietary nitrate load (beetroot juice 500 mL), BP was substantially reduced (⌬ max Ϫ10.4/8 mm Hg); an effect that correlated with peak increases in plasma nitrite concentration. The dietary nitrate load also prevented endothelial dysfunction induced by an acute ischemic insult in the human forearm and significantly attenuated ex vivo platelet aggregation in response to collagen and ADP. Interruption of the enterosalivary conversion of nitrate to nitrite (facilitated by bacterial anaerobes situated on the surface of the tongue) prevented the rise in plasma nitrite, blocked the decrease in BP, and abolished the inhibitory effects on platelet aggregation, confirming that these vasoprotective effects were attributable to the activity of nitrite converted from the ingested nitrate. These findings suggest that dietary nitrate underlies the beneficial effects of a vegetable-rich diet and highlights the potential of a "natural" low cost approach for the treatment of cardiovascular disease. Key Words: diet Ⅲ nitric oxide Ⅲ blood pressure Ⅲ hypertension Ⅲ ischemia/reperfusion Ⅲ platelets Ⅲ endothelium P erhaps the largest public health initiative in the Western world has focused on improvement of diet, particularly in those with a high risk of cardiovascular disease. Trials have shown that diets rich in fruits and vegetables reduce blood pressure (BP; Dietary Approaches to Stop Hypertension; DASH, Vegetarian Diet and BP) 1,2 and adverse cardiovascular events. [3][4][5][6][7] These protective effects have previously been attributed to the high antioxidant vitamin content, yet large clinical trials have failed to provide evidence in support of this thesis. 8,9 The greatest protection against coronary heart disease afforded by a change in diet is that associated with the consumption of green leafy vegetables (eg, spinach, lettuce). 6 Such vegetables, also including beetroot, commonly have a high inorganic nitrate (NO 3 Ϫ ) content. 10,11 In humans, after absorption through the stomach wall, Ϸ25% of consumed nitrate enters the enterosalivary circulation where it is reduced to nitrite (NO 2 Ϫ ) by bacterial nitrate reductases from facultative anaerobes on the dorsal surface of the tongue. [12][13][14] This nitrite is swallowed and in the acidic environment of the stomach is reduced to nitric oxide (NO) or re-enters the circulation as nitrite. Indeed, it has been hypothesized that dietary nitrate represents an intravascular source of the pleiotropic, vasoprotective molecule NO, which supplements conventional NO generation by NO synthases (NOS). 15 Endothelium-derived NO is a potent dilator, governs systemic BP, and retards atheroge...

Diets rich in fruits and vegetables reduce blood pressure (BP) and the risk of adverse cardiovascular events. However, the mechanisms of this effect have not been elucidated. Many vegetables possess a high nitrate content and we hypothesized that this might represent a source of vasoprotective NO via bioactivation to nitrite. In 14 healthy volunteers, approximately 3h following ingestion of a dietary nitrate load (500ml beetroot juice), BP was substantially reduced (Δmax‐10.4/8 mmHg); this effect correlated with peak increases in plasma nitrite, but not nitrate, concentration. The dietary nitrate load also prevented endothelial dysfunction induced by an acute ischemic insult in the human forearm and significantly attenuated ex vivo platelet aggregation in response to collagen and ADP. Interruption of the enterosalivary conversion of nitrate to nitrite (facilitated by bacterial anaerobes situated on the surface of the tongue), prevented the rise in plasma nitrite, blocked the decrease in BP and abolished the inhibitory effects on platelet aggregation, confirming that these vasoprotective effects were due to the activity of nitrite converted from the ingested nitrate. These findings suggest that dietary nitrate underlies the beneficial effects of a vegetable‐rich diet and highlights the potential of a ‘natural’, low cost approach for the treatment of cardiovascular disease.

Colonoscopy is a common procedure for diagnosing a wide range of conditions and symptoms affecting the large bowel. Research has shown that the examination itself may induce transient bacterial infections. Specifically acute bacterial prostatitis (ABP) has little mention in medical literature as a recognized complication of this procedure. Here we discuss a 37 year old male presenting with symptoms suggesting lower urinary tract infection after having undergone colonoscopy followed by recurrent episodic haematuria and lower urinary tract symptoms (LUTS). Physicians and endoscopists should be aware of the risk of acute bacterial prostatitis as a potential complication of colonoscopy in order to minimize misdiagnosis as well as the complications associated with the delayed treatment of it. In addition male patients and the immunocompromised should be fully counselled regarding this risk prior to undertaking this procedure.

Cerebrospinal fluid (CSF) rhinorrhea is the leakage of cerebrospinal fluid through the nostrils due to an abnormal communication between the nasal cavity and sub–arachnoid space. CSF rhinorrhoea can be traumatic or spontaneous. CSF rhinorrhea carries a risk of ascending infection leading to meningitis. CSF rhinorrhea is not very common and could be easily mistaken for rhinitis. Physicians need to have a high index of suspicion to diagnose and treat this rare and potentially serious condition. Here we discuss a case of delayed post-traumatic CSF rhinorrhea -an unusual presentation in a primary care setting, focusing on presentation and diagnosis.