Apocynin but not L-arginine prevents and reverses dexamethasone-induced hypertension in the rat.

BACKGROUND: Dexamethasone (Dex)-hypertension in rats is associated with increased oxidative stress. We investigated effects of the NAD(P)H oxidase inhibitor apocynin and the nitric oxide (NO) precursor L-arginine on Dex-hypertension to determine the relative roles of NAD(P)H oxidase and uncoupling in the reactive oxygen species (ROS) generation and hypertension. METHODS: Male Sprague-Dawley rats (n = 10/group) received Dex (20 microg/kg/day subcutaneously) or saline (vehicle) for 14 days. In a prevention study, rats received 4 days of apocynin treatement (1.5 mmol/L in drinking water) followed by Dex/saline for 12 days. In reversal studies, apocynin or L-arginine was given from day 8 to 14. Systolic blood pressure (SBP) was measured by tail cuff, and thymus weight was used as a marker of glucocorticoid activity. RESULTS: Administration of Dex increased SBP (104 +/- 3 to 122 +/- 3 mm Hg, P < .01, mean +/- SEM) and decreased thymus and body weight (P' < .05). Apocynin alone had no effect on SBP, BW, or thymus weight. Apocynin prevented (122 +/- 4 Dex, 111 +/- 3 mm Hg Apocynin+Dex, P' < .05) and reversed Dex-hypertension (130 +/- 4 to 116 +/- 4 mm Hg, P < .01). L-arginine did not reverse Dex-hypertension. CONCLUSIONS: In male SD rats, apocynin but not l-arginine prevented and reversed Dex-hypertension, suggesting that NAD(P)H oxidase-mediated superoxide production but not endothelial nitric oxide synthase uncoupling is important in Dex-hypertension.

Diagnosing an atypical site of giant cell arteritis with magnetic resonance angiography: a case report.

BACKGROUND: Giant cell arteritis typically involves the temporal arteries, but can involve other cranial arteries. Temporal artery biopsy is the mainstay for the diagnosis of giant cell arteritis; however, biopsy may be problematic if giant cell arteritis involves other cranial arteries that are inaccessible for sampling. In these situations, magnetic resonance angiography is a useful, non-invasive adjunctive method in the diagnosis of giant cell arteritis. In this case report, we describe a case of giant cell arteritis involving only the occipital artery which was revealed by magnetic resonance angiography. CASE PRESENTATION: A 67-year-old Caucasian man was admitted to our hospital with a 4-week history of malaise, fever, and mild occipital headaches. There were no other positive findings on physical examination. Laboratory studies were remarkable for normocytic anemia, raised inflammatory markers, and mildly deranged liver function tests. To exclude intracranial pathology, he underwent a cranial magnetic resonance imaging with gadolinium, which demonstrated a thickened wall and mural enhancement of his right occipital artery, consistent with giant cell arteritis. His temporal arteries were normal. His occipital arteries were not accessible for biopsy and he was commenced on high-dose prednisolone (60 mg daily). His symptoms resolved completely after a week of glucocorticoid steroid treatment and he was well on 5 mg of prednisolone once a day on follow-up. CONCLUSION: While magnetic resonance angiography may not replace the need for biopsy, it may have a diagnostic role in suspected giant cell arteritis, such as when the involved arteries are inaccessible for biopsy.

Obstructive Uropathy Secondary to Uretero-inguinal Hernia.

Uretero-inguinal hernia in patients with native kidneys is rare. We report a case of an 84-year-old man who was diagnosed with obstructive uropathy secondary to uretero-inguinal hernia, with no past history of herniorrhaphy or congenital genitourinary malformation. Uretero-inguinal hernias are predominantly indirect inguinal hernias and may be paraperitoneal or extraperitoneal. Computed tomography (CT) is a non-invasive diagnostic tool for uretero-inguinal hernia. Herniorrhaphy is indicated in all cases of uretero-inguinal hernia to prevent obstructive uropathy.