Naloxone does not modify the hemodynamic and neuroendocrine effects of clonidine in normal humans

The relationship between central opioidergic and noradrenergic central control mechanisms of blood pressure was investigated in normal men by evaluating the interference exerted by naloxone, a specific opiate antagonist, on the cardiovascular (blood pressure and heart rate) and neuroendocrine [human growth hormone (HGH) stimulation] effects of clonidine, a centrally acting alpha-adrenergic agonist, according to two different protocols. In series 1, the effects of placebo (normal saline), clonidine (0.15 mg i.v.), and naloxone (0.4 mg i.v.) were compared with that of clonidine plus naloxone (0.15 and 0.4 mg i.v., respectively), in seven normal male subjects. Clonidine decreased blood pressure and heart rate, and increased HGH levels. Naloxone administered alone (0.4 mg i.v.) did not modify blood pressure, heart rate, and HGH levels, while naloxone (0.4 mg) pretreatment left unaltered the hemodynamic and neuroendocrine effects of clonidine. In series 2, in five additional normal males, the effect of increasing doses of naloxone (0.4, 2.0, and 8.0 mg i.v.) on the pharmacodynamic activity of clonidine (0.15 mg i.v.) was further evaluated. Clonidine alone decreased blood pressure and heart rate and increased HGH levels, while naloxone pretreatment, in the whole range of doses studied, did not significantly modify the action of clonidine. These data suggest that a central opioidergic tone does not modulate the effect of central alpha-noradrenergic stimulation in normal humans.     

Methodological simplifications in radioimmunoassay of urinary aldosterone.

Simplification of radioimmunoassay procedures of urinary aldosterone-18-glucuronide was attempted, taking into consideration the aspects implied by the hydrolysis of urine and the assay itself. The procedure standardized for the hydrolysis step (samples diluted with a two-fold volume of 0.2 N HCl and incubated at 30 degrees C for 16-24 h) proved suitable in terms of practicability and accuracy. Aldosterone antisera, raised in the rabbit against an aldosterone-3-bovine albumin conjugate, were selected according to their specificity towards competing steroids. Depending on the characteristics of the antisera used, an assay of extracts, or even direct measurements of hydrolyzed urines excluding any extraction, were found to yield reliable results. In the case of a high-quality antiserum, evidence for the adequacy of assay on non-hydrolyzed urine extracts for the measurement of the excretion of unconjugated aldosterone was provided by some preliminary data. The results of the experiments, directed at the methodological and clinical validation of the simplified procedures, are reported and discussed in this paper.     

Multicentre comparison of the antihypertensive effect of acebutolol and hydrochlorothiazide in uncomplicated mild-moderate hypertension in the elderly

Summary To evaluate the efficacy of acebutolol, 400–600 mg/day in elderly hypertensive patients, and to compare it with hydrochlorothiazide 25–50 mg/day, 45 patients with mild-moderate uncomplicated hypertension were treated for 6 weeks in a multicentre, single-blind, randomized, crossover trial. Acebutolol decreased supine systolic blood pressure from 186.5 to 162.7 mmHg and diastolic blood pressure from 107.4 to 92.4 mmHg. Hydrochlorothiazide decreased systolic blood pressure from 185.0 to 166.4 and diastolic blood pressure from 107.2 to 96.4. There was no difference between the effects of acebutolol and hydrochlorothiazide on blood pressure during the trial. Both drugs proved to be safe and effective antihypertensive agents, provided the major contraindications for their use were taken into account. Beta-blockade by acebutolol was highly effective in treating mild-moderate arterial hypertension in the elderly.     

Headache: Prevalence and relationship with office or ambulatory blood pressure in a general population sample (the Vobarno Study)

The association of headache and arterial hypertension is still controversial, although headache is usually considered a symptom of hypertension. The aim of this study is to evaluate the prevalence of headache in a general population sample and the relationship with arterial hypertension, as diagnosed by office measurements and ambulatory monitoring of blood pressure (BP). Patients and methods. In the randomized sample of the Vobarno population, 301 subjects (126 males, 175 females, age range 35-50 years) underwent a structured standardized headache questionnaire, office and 24-h ambulatory BP monitoring. Results. Prevalence of lifetime headache and of migraine was greater in females than in males. Office and 24-h BP values did not differ between subjects without headache and subjects with headache. No differences in headache prevalence (58% vs 55%), migraine prevalence (32% vs 28%) and use of analgesic drugs in the presence of headache (82% vs 78%) were observed between hypertensive patients (93.5% newly diagnosed, 6.5% treated) and normotensive subjects. Conclusions. In a general population sample, hypertension (diagnosed by office and/or 24-h BP) is not associated with headache.     

Endothelium-dependent vasodilation and carotid artery wall remodeling in athletes and sedentary subjects

In this study, the relationship between age, carotid artery remodeling, and endothelium-dependent vasodilation is investigated in sedentary subjects and athletes. Thirty-two young and old healthy sedentary subjects and 32 age-matched endurance athletes underwent ultrasonography of the carotid wall for measuring intima-media thickness (IMT) and corrected integrated backscatter (C-IBS), two early indicators of the atherosclerosis process. Endothelium-dependent vasodilation was assessed by intra-brachial acetylcholine (strain-gauge plethysmography), at baseline and during NO sythase inhibitor NG-monomethyl-L-arginine (L-NMMA), and the antioxidant Vitamin C. Response to sodium nitroprusside (SNP) was also evaluated. Independently of trained status, IMT and C-IBS were higher in older than in young individuals (p<0.0001), while response to acetylcholine, but not to SNP, was lower (p<0.0001). Older athletes showed lower IMT, lower C-IBS (p<0.0001), greater response to acetylcholine (p<0.0001), and greater inhibition of acetylcholine by L-NMMA (p<0.001) than older controls. Only in older sedentary individuals, Vitamin C increased response to acetylcholine (p<0.001) and restored the inhibiting effect of L-NMMA (p<0.01). In the whole population maximal acetylcholine-induced vasodilation was inversely related to IMT (r=-0.60, p<0.0001) and to C-IBS (r=-0.56, p<0.0001). In conclusion, regular physical training can attenuate the age-related impairment of endothelium-dependent vasodilation, which is related to an attenuation of the age-induced remodeling of the carotid wall.     

Low-grade systemic inflammation causes endothelial dysfunction in patients with Hashimoto's thyroiditis

OBJECTIVE: The objective of this study was to assess whether low-grade systemic inflammation might contribute to the pathogenesis of endothelial dysfunction in patients with subclinical hypothyroidism (sHT) and autoimmune thyroiditis. BACKGROUND: sHT patients are characterized by peripheral endothelial dysfunction and low-grade inflammation. METHODS: In 53 sHT and 45 healthy subjects, we studied the forearm blood flow (strain-gauge plethysmography) response to intrabrachial acetylcholine (Ach) (0.15-15 microg/min.dl) with and without local vascular COX inhibition by intrabrachial indomethacin (50 microg/min.dl) or nitric oxide synthase blockade by N-mono methyl arginine (L-NMMA) (100 microg/min.dl) or the antioxidant vitamin C (8 mg/min.dl). The protocol was repeated 2 h after systemic nonselective COX inhibition (100 mg indomethacin) or selective COX-2 blockade (200 mg celecoxib) oral administrations. RESULTS: sHT patients showed higher C-reactive protein and IL-6 values. In controls, vasodilation to Ach was blunted by L-NMMA and unchanged by vitamin C. In contrast, in sHT, the response to Ach, reduced in comparison with controls, was resistant to L-NMMA and normalized by vitamin C. In these patients, systemic but not local indomethacin normalized vasodilation to Ach and the inhibition of L-NMMA on Ach. Similar results were obtained with celecoxib. When retested after indomethacin administration, vitamin C no longer succeeded in improving vasodilation to Ach in sHT patients. Response to sodium nitroprusside was unchanged by indomethacin or celecoxib. CONCLUSIONS: In sHT patients, low-grade chronic inflammation causes endothelial dysfunction and impaired nitric oxide availability by a COX-2-dependent pathway leading to increased production of oxidative stress.     

The impact of interferon Beta and natalizumab on comorbid migraine in multiple sclerosis

Background.— Some multiple sclerosis (MS)‐specific therapies may exacerbate a comorbid migraine. Whereas data regarding the impact of interferon beta (IFNB) on this comorbidity have been reported, studies on the role of natalizumab (NTZ) are still lacking. Purpose.— Our aim was to compare the impact of IFNB and NTZ on the frequency and disability of comorbid migraine in MS patients. Methods.— We performed a longitudinal evaluation on MS patients with comorbid migraine previously assessed at our center and retested for the present study, by comparing data from 33 patients originally treated with IFNB and thereafter switched to NTZ vs 30 patients continued currently to receive IFNB. Results.— Longitudinal analysis showed a significant reduction of migraine frequency (from a mean value of 8.4 to 5.1 days per month; P = .034) and Migraine Disability Assessment Scale (MIDAS) score (from a mean value of 14.2 to 10.5; P = .045) in the subgroup patients switched from IFNB to NTZ but not in those remaining in the IFNB recipient, irrespective of level of fatigue, trait anxiety, depression, alexithymia, or other clinical variables. Conclusions.— Our findings suggest that NTZ did not exacerbate comorbid migraine in MS patients and support the hypothesis that IFNB might represent an important trigger for migraine worsening.     

Treatment of renovascular disease and of renovascular hypertension

ABSTRACT: Treatment of occlusive lesions of renal arteries, defined as renovascular disease (RVD), is aimed both at preventing ischemic renal disease (IRD) and rescuing renal function through revascularization procedures, such as PTRA, endovascular stenting and surgical revascularization, as well as curing or improving hypertension in the presence of renovascular hypertension (RVH), i.e. hypertension caused by these vascular lesions. Preventive treatment of IRD is still an individual decision making process based on the type of renal lesions, degree of renal stenosis and progressive loss of renal mass as well as on immediate and late technical success of revascularization procedures together with their rate of complications. Rescue of renal function and-or prediction of the outcome of renal function after successful revascularization depends not only on the possibility of clarifying whether the decrease in renal function is a functioning-reversible phenomenon linked to renal hypoperfusion but also on the potential risk that the revascularization procedure may induce irreversible kidney damage. The rationale for treating RVH through revascularization procedures derives from the possibility of establishing a pathogenetic link between the occlusive lesions and hypertension, mainly through renal vein renin measurement and captopril renography and possibly their combination. Finally, medical treatment of hypertension is needed in patients who cannot undergo or refuse revascularization and whose blood pressure is not normalized by these procedures.     

Twins: mirrors of the immune system

Twin studies are a powerful tool to assess genetic and nongenetic factors in multifactorial, immune-mediated diseases. Here, Marco Salvetti and colleagues review important results from such studies and highlight their potential value. Future developments that should help to realize the potential of twin studies are discussed.     

The role of open abdomen in non-trauma patient: WSES Consensus Paper

The open abdomen (OA) is defined as intentional decision to leave the fascial edges of the abdomen un-approximated after laparotomy (laparostomy). The abdominal contents are potentially exposed and therefore must be protected with a temporary coverage, which is referred to as temporal abdominal closure (TAC). OA use remains widely debated with many specific details deserving detailed assessment and clarification. To date, in patients with intra-abdominal emergencies, the OA has not been formally endorsed for routine utilization; although, utilization is seemingly increasing. Therefore, the World Society of Emergency Surgery (WSES), Abdominal Compartment Society (WSACS) and the Donegal Research Academy united a worldwide group of experts in an international consensus conference to review and thereafter propose the basis for evidence-directed utilization of OA management in non-trauma emergency surgery and critically ill patients. In addition to utilization recommendations, questions with insufficient evidence urgently requiring future study were identified.