Surgical and Nonsurgical Endodontic Treatment-induced Stress

This observational study compared physiologic and psychological indicators of stress between two groups of 30 healthy patients undergoing either surgical or nonsurgical endodontic treatments. Heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure were monitored during care sessions. The patients were asked to score their anxiety before treatment and to report pain, stress, and/or discomfort experienced during care. Variations in HR and SBP were significantly dependent on treatment group (HR: F = 6, p < 0.001; SBP: F = 4, p = 0.05). Intergroup differences increased during the active steps of the treatment, such as local anesthesia, rotary instrumentation, periradicular curettage, root filling, and field removal. Moreover, the level of stress experienced during the care procedure was correlated to the level of anticipated anxiety in both groups. This study raises questions on the indications for anxiolysis or sedation in endodontic patients as a means of preventing the neurophysiologic consequences of stress.     

Restoration of Serotonin Neuronal Firing Following Long-Term Administration of Bupropion but Not Paroxetine in Olfactory Bulbectomized Rats

Background:

Olfactory bulbectomized rats generally manifest many of the neurochemical, physiological, and behavioral features of major depressive disorder in humans. Another interesting feature of this model is that it responds to chronic but not acute antidepressant treatments, including selective serotonin reuptake inhibitors. The purpose of the present study was first to characterize the firing activity of dorsal raphe serotonin neurons in olfactory bulbectomized rats and then examine the effects of 2 antidepressants, bupropion and paroxetine.

Methods:

Olfactory bulbectomy was performed by aspirating olfactory bulbs in anesthetized rats. Vehicle and drugs were delivered for 2 and 14 days via subcutaneously implanted minipumps. In vivo electrophysiological recordings were carried out in male anesthetized Sprague-Dawley rats.

Results:

Following ablation of olfactory bulbs, the firing rate of serotonin neurons was decreased by 36%, leaving those of norepinephrine and dopamine neurons unchanged. In olfactory bulbectomized rats, bupropion (30mg/kg/d) restored the firing rate of serotonin neurons to the control level following 2- and 14-day administration and also induced an increase in the tonic activation of serotonin_1A receptors; paroxetine (10mg/kg/d) did not result in a return to normal of the attenuated firing of serotonin neurons in olfactory bulbectomized rats. In the hippocampus, although at a higher dose of WAY 100635 than that required in bupropion-treated animals, paroxetine administration also resulted in an increase in the tonic activation of serotonin_1A receptors.

Conclusions:

The present results indicate that unlike paroxetine, bupropion administration normalized serotonin neuronal activity and increased tonic activation of the serotonin_1A receptors in hippocampus.     

Evaluation of bone mineral density, hormones, biochemical markers of bone metabolism, and osteoprotegerin serum levels in patients with ankylosing spondylitis

OBJECTIVE: To evaluate bone metabolism in patients with ankylosing spondylitis (AS) and test the hypothesis that osteoprotegerin (OPG) serum concentrations are correlated with the severity of bone loss as assessed by bone mineral density (BMD) and biochemical markers of bone turnover. Osteoporosis occurs frequently in patients with AS and OPG represents a soluble decoy receptor that neutralizes receptor activator of nuclear factor-kB ligand (RANKL), an essential cytokine for osteoclast function. METHODS: Clinical data, radiographs of the spine, BMD of lumbar spine and the femur, biochemical markers of bone turnover, and serum levels of OPG were evaluated in 264 patients with AS (72% men) and 240 age-matched healthy controls (76% men). RESULTS: OPG serum levels were significantly lower in patients with AS compared to controls (1.84 +/- 1.15 vs 3.54 +/- 2.18 pmol/l, p < 0.001), and in contrast to controls, were not positively correlated with age. In addition, BMD of the hip and the femoral neck were significantly lower in patients with AS than in controls. There were positive correlations in patients with AS between BMD of the femoral neck and free testosterone serum levels in men and free estradiol serum levels in women, respectively. Patients with AS and osteoporosis had higher biochemical markers of bone resorption and inflammatory activity. CONCLUSION: Bone loss in patients with AS is associated with low sex steroid hormone serum levels, high biochemical markers of bone resorption and inflammatory activity, low OPG serum levels, and lack of compensatory age-related increase of OPG serum levels.     

Interferon-alpha and -beta differentially regulate osteoclastogenesis: role of differential induction of chemokine CXCL11 expression

In humans, type I interferon (IFN) is a family of 17 cytokines, among which the alpha subtypes and the beta subtype are differentially expressed. It has been suggested that IFN-beta activates a specific signaling cascade in addition to those activated by all type I IFNs. Nevertheless, no true biological relevance for a differential activity of alpha and beta IFN subtypes has been identified so far. Because type I IFNs are critical for the regulation of osteoclastogenesis in mice, we have compared the effect of IFN-alpha2 and IFN-beta on the differentiation of human monocytes into osteoclasts. Primary monocytes undergoing osteoclastic differentiation are highly and equally sensitive to both alpha2 and beta IFNs as determined by measuring the induction levels of several IFN-stimulated genes. However, IFN-beta was 100-fold more potent than the alpha2 subtype at inhibiting osteoclastogenesis. Expression profiling of the genes differentially regulated by IFN-alpha2 and IFN-beta in this cellular system revealed the chemokine CXCL11 as the only IFN-induced gene differentially up-regulated by IFN-beta. We show that recombinant CXCL11 by itself inhibits osteoclastic differentiation. These results indicate that autocrine-acting CXCL11 mediates, at least in part, the regulations of osteoclastogenesis by type I IFNs.     

Face recognition in schizophrenia: do individual and average ROCs tell the same story?

Introduction. Many studies have shown that recollection process is impaired in patients with schizophrenia, whereas familiarity is generally spared. However, in these studies, the Receiver Operating Characteristic (ROC) presented is average ROC likely to mask individual differences.

Methods. In the present study using a face-recognition task, we computed the individual ROC of patients with schizophrenia and control participants. Each group was divided into two subgroups on the basis of the type of recognition processes implemented: recognition based on familiarity only and recognition based on familiarity and recollection.

Results. The recognition performance of the schizophrenia patients was below that of the control participants only when recognition was based solely on familiarity. For the familiarity-alone patients, the score obtained on the Scale for the Assessment of Positive Symptoms (SAPS) was correlated with the variance of the old-face familiarity. For the familiarity-recollection patients, the score obtained on the Scale for the Assessment of Negative Symptoms (SANS) was correlated with the decision criterion and with the old-face recollection probability.

Conclusions. These results show that one cannot ascribe the impaired recognition observed in patients with schizophrenia to a recollection deficit alone. These results show that individual ROC can be used to distinguish between subtypes of schizophrenia and could serve as a basis for setting up specific cognitive remediation therapy for individuals with schizophrenia.