Cyclooxygenase-2--specific inhibitors and cardiorenal function: a randomized, controlled trial of celecoxib and rofecoxib in older hypertensive osteoarthritis patients

BACKGROUND: Arthritis and hypertension are common comorbid conditions affecting elderly adults. Use of nonsteroidal anti-inflammatory drugs in patients treated with antihypertensive medication can lead to destabilization of blood pressure control and other cardiorenal events. The potential for similar interactions with cyclooxygenase-2-specific inhibitors has not been fully explored. The authors evaluated the cardiorenal safety of two new cyclooxygenase-2-specific inhibitors, celecoxib and rofecoxib.METHODS: This study was a 6-week, randomized, parallel-group, double-blind trial in patients with osteoarthritis who were > or =65 years of age and were taking antihypertensive agents. Patients received once-daily celecoxib 200 mg or rofecoxib 25 mg. The primary endpoints were the development of edema, changes in systolic blood pressure, and changes in diastolic blood pressure as measured at any time point in the study. Measurements occurred at baseline and after 1, 2, and 6 weeks of treatment. FINDINGS: Eight hundred ten patients received study medication (celecoxib, n = 411; rofecoxib, n = 399). Nearly twice as many rofecoxib- compared with celecoxib-treated patients experienced edema (9.5% vs. 4.9%, P = 0.014). Systolic blood pressure increased significantly in 17% of rofecoxib- compared with 11% of celecoxib-treated patients (P = 0.032) at any study time point. Diastolic blood pressure increased in 2.3% of rofecoxib- compared with 1.5% of celecoxib-treated patients (P = 0.44). At week 6, the change from baseline in mean systolic blood pressure was +2.6 mmHg for rofecoxib compared with -0.5 mmHg for celecoxib (P = 0.007). CONCLUSIONS: Patients taking antihypertensive therapy and receiving cyclooxygenase-2-specific inhibitors should be monitored for the development of cardiorenal events. Patients receiving celecoxib experienced less edema and less destabilization of blood pressure control compared with those receiving rofecoxib.     

Baseline correction of phase contrast images improves quantification of blood flow in the great vessels.

PURPOSE: Phase-contrast Cardiovascular Magnetic Resonance Imaging (CMR) generally requires the analysis of stationary tissue adjacent to a blood vessel to serve as a baseline reference for zero velocity. However, for the heart and great vessels, there is often no stationary tissue immediately adjacent to the vessel. Consequently, uncorrected velocity offsets may introduce substantial errors in flow quantification. The purpose of this study was to assess the magnitude of these flow errors and to validate a clinically applicable method for their correction. MATERIALS AND METHODS: In 10 normal volunteers, phase-contrast CMR was used to quantify blood flow in the main pulmonary artery (Qp) and the aorta (Qs). Following image acquisition, phase contrast CMR was performed on a stationary phantom using identical acquisition parameters so as to provide a baseline reference for zero velocity. Aortic and pulmonary blood flow was then corrected using the offset values from the phantom. RESULTS: The mean difference between pulmonary and aortic flow was 26 +/- 21 mL before correction and 7.1 +/- 6.6 mL after correction (p = 0.002). The measured Qp/Qs was 1.25 +/- 0.20 before correction and 1.05 +/- 0.07 after correction (p = 0.001). CONCLUSION: Phase-contrast CMR can have substantial errors in great vessel flow quantification if there is no correction for velocity offset errors. The proposed method of correction is clinically applicable and provides a more accurate measurement of blood flow.     

MMPs initiate Schwann cell-mediated MBP degradation and mechanical nociception after nerve damage

Matrix metalloproteinases (MMPs) emerge as modulators of neuropathic pain. Because myelin protects Aβ afferents from ectopic hyperexcitability and nociception from innocuous mechanical stimuli (or mechanical allodynia), we analyzed the role of MMPs in the development of mechanical allodynia through myelin protein degradation after rat and MMP-9−/− mouse L5 spinal nerve crush (L5 SNC). MMPs were shown to promote selective degradation of myelin basic protein (MBP), with MMP-9 regulating initial Schwann cell-mediated MBP processing after L5 SNC. Acute and long-term therapy with GM6001 (broad-spectrum MMP inhibitor) protected from injury-induced MBP degradation, caspase-mediated apoptosis, macrophage infiltration in the spinal nerve and inhibited astrocyte activation in the spinal cord. The effect of GM6001 therapy on attenuation of mechanical allodynia was robust, immediate and sustained through the course of L5 SNC. In conclusion, MMPs mediate the initiation and maintenance of mechanical nociception through Schwann cell-mediated MBP processing and support of neuroinflammation.     

The repopulation potential of fetal liver hematopoietic stem cells in mice exceeds that of their liver adult bone marrow counterparts

Varying, limiting numbers of unseparated or purified cells (Ly-5.1), either from 14.5-day-old fetal liver (FL) or from adult bone marrow (BM) were coinjected with 10(5) unseparated BM cells (Ly-5.2) into lethally irradiated adult C57B1/6 recipients (Ly-5.2). The kinetics of donor cell repopulation of the lymphoid and myeloid compartments by Ly- 5.1+ donor hematopoietic stem cells (ie, competitive repopulation units [CRU]) were monitored at various time points after the transplantation by Ly-5 analysis of the peripheral white blood cells (WBC). Recipients that had received on average less than 2 adult BM or FL CRU did not show a significant difference in the level of donor-reconstitution when analyzed 4 weeks after the transplantation, However, at 8 and 16 weeks, the FL recipients showed a significantly higher percentage of donor- derived nucleated peripheral blood cells than did the recipients of adult BM cells. Analysis of individual mice showed that approximately 80% of the recipients of FL CRU showed an increase in mature WBC output between 4 and 8 weeks after transplantation, whereas this occurred in less than 40% in the recipients of adult BM cells. In addition to this effect on mature cell output, the cellularity of the reconstituted BM was significantly higher in recipients of FL CRU than in recipients of adult BM CRU, even at 7 to 9 months after transplantation, which is consistent with an increased clonal expansion of FL CRU. When marrow cells from primary recipients of FL CRU were injected into secondary recipients, a significantly higher percentage of these mice showed donor-reconstitution of their lymphoid and myeloid compartments (P < .01) and to a greater extent (P < .008) as compared with mice that had received marrow cells from primary recipients of similar numbers of adult BM CRU. Taken together, these results show that individual FL CRU exhibit a greater proliferative activity in vivo than similar cells from adult BM that is accompanied by a greater production of daughter CRU.     

Locomotor effects of nitrous oxide in mice: requirement of newly-synthesized and main intraneuronal storage pools of dopamine

Abstract— Nitrous oxide increases locomotor activity in mice. Other locomotor stimulants are thought to act via central dopaminergic mechanisms and can be divided into two groups as determined by their antagonism by tyrosine hydroxylase inhibitors or by reserpine pretreatment. The purpose of the present study was to determine if nitrous oxide fits one or the other of the groups. Mice were acclimatized for 1 h to exposure chambers (4 L filtration flasks), in air, delivered at 4 L min^?1 and then exposed to N₂O:O₂ (50:50), also delivered at 4 L min^?1. Locomotor activity was evaluated at 10 min intervals throughout the experiment. Racemic α-methyltyrosine methyl ester HCl (200 mg kg^?1), administered at the beginning of acclimatization, almost totally eliminated the nitrous oxide effect but not that of methylphenidate HCl (20 mg kg^?1). Reserpine pretreatment (5 mg kg^?1 18 h) totally eliminated the nitrous oxide effect but not that of amphetamine (5 mg kg^?1). The results suggest that nitrous oxide requires both the newly synthesized and the main storage pools of dopamine and do not allow assignment of the agent, specifically, to either of the groups.     

The role of neuroinflammation in neuropathic pain: mechanisms and therapeutic targets

Neuroinflammation is a proinflammatory cytokine-mediated process that can be provoked by systemic tissue injury but it is most often associated with direct injury to the nervous system. It involves neural-immune interactions that activate immune cells, glial cells and neurons and can lead to the debilitating pain state known as neuropathic pain. It occurs most commonly with injury to peripheral nerves and involves axonal injury with Wallerian degeneration mediated by hematogenous macrophages. Therapy is problematic but new trials with anti-cytokine agents, cytokine receptor antibodies, cytokine-signaling inhibitors, and glial and neuron stabilizers provide hope for future success in treating neuropathic pain.     

Thirteen-year prospective study between fish consumption,long-chain N-3 fatty acids intakes and cognitive function

Objectives  

Because of their structural, anti-inflammatory and antithrombic properties, longchain n-3 fatty acids may be key factors in the aging process. We sought to elucidate the association between intake of long-chain n-3 fatty acids and/or fish and cognitive function evaluated 13 years after dietary assessment.