Increased anterior insula activity in anxious individuals is linked to diminished perceived control.

Individuals with high-trait anxiety frequently report decreased perceived control. However, it is unclear how these processes are instantiated at a neural level. Prior research suggests that individuals prone to anxiety may have exaggerated activity in the anterior insula and altered activity in the cingulate cortex during anticipation of aversive events. Thus, we hypothesized that anxiety proneness influences anterior insula activation during anticipation of unpredictable threat through decreased perceived control. Forty physically healthy adults underwent neuroimaging while they explored computer-simulated contexts associated either with or without the threat of an unpredictable shock. Skin conductance, anxiety ratings and blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging were used to assess responses to threat versus no threat. Perceived control was measured using the Anxiety Control Questionnaire-Revised. Mediation analysis examined how anxiety proneness influenced BOLD activity. Anticipation of unpredictable threat resulted in increased skin conductance responses, anxiety ratings and enhanced activation in bilateral insula, anterior midcingulate cortex (aMCC) and bed nucleus of the stria terminalis. Individuals with greater anxiety proneness and less perceived control showed greater activity in dorsal anterior insula (dAI). Perceived control mediated the relationship between anxiety proneness and dAI activity. Increased dAI activity was associated with increased activity in aMCC, which correlated with increased exploratory behavior. Results provide evidence that exaggerated insula activation during the threat of unpredictable shock is directly related to low perceived control in anxiety-prone individuals. Perceived control thus may constitute an important treatment target to modulate insula activity during anxious anticipation in anxiety-disordered individuals.

Pain and emotion: effects of affective picture modulation.

OBJECTIVE AND METHODS: Two experiments examined the impact of viewing unpleasant, pleasant, and neutral photographic slides on cold-pain perception in healthy men and women. In each experiment, participants viewed one of three slide shows (experiment 1 = fear, disgust, or neutral; experiment 2 = erotic, nurturant, or neutral) immediately before a cold-pressor task. Skin conductance and heart rate were recorded during the slide shows, whereas visual analog scale ratings of pain intensity and unpleasantness thresholds and pain tolerance were recorded during the cold-pressor task. RESULTS: Viewing fear and disgust slides decreased pain intensity and unpleasantness thresholds, but only the fear slides decreased pain tolerance. In contrast, viewing erotic, but not nurturant, slides increased pain intensity and unpleasantness threshold ratings on the visual analog scale in men, whereas neither nurturant nor erotic slides altered pain tolerance. CONCLUSIONS: These results are consistent with a motivational priming model that predicts that unpleasant affective states should enhance pain and that pleasant affective states should attenuate it.

Noise stress and human pain thresholds: divergent effects in men and women.

Considerable animal research suggests that exposure to noxious and nonnoxious fear-inducing stimuli can produce hypoalgesia. Although this effect is thought to generalize across species, only a few studies have examined the pain modulatory effects of nonnoxious fear-eliciting stimuli in humans. The present study examined whether exposure to a series of loud noise bursts would produce a fear-related hypoalgesia in male and female human subjects. Both subjective and physiologic measures (skin conductance level, heart rate) indicated that noise exposure resulted in fear, sympathetic arousal, and decreased pain reactivity in women (n = 20). In contrast, men (n = 20) did not experience fear or physiologic arousal, but reacted with surprise and increased pain reactivity. These findings provide additional evidence that hypoalgesia is mediated by fear and physiologic arousal. Although future studies should directly manipulate surprise, it appears that surprise without fear and physiologic arousal might enhance pain processing.

Effectiveness of short-course therapy (5 days) with cefuroxime axetil in treatment of secondary bacterial infections of acute bronchitis.

Five hundred thirty-seven patients were enrolled in two independent, investigator-blinded, multicenter, randomized clinical trials comparing the clinical and bacteriologic efficacies and the safety of 5- or 10-day treatment with cefuroxime axetil with those of 10-day treatment with amoxicillin-clavulanate in the treatment of secondary bacterial infections of acute bronchitis. Patients received either 5 or 10 days of treatment (n = 177 in each group) with cefuroxime axetil at 250 mg twice daily or 10 days of treatment (n = 183) with amoxicillin-clavulanate at 500 mg three times daily. Patients in the cefuroxime axetil (5 days) group received placebo on days 6 to 10. Bacteriologic assessments were based on sputum specimen cultures obtained preceding and, when possible, following treatment. Organisms were isolated from the pretreatment sputum specimens of 242 of 537 (45%) patients, with the primary pathogens being Haemophilus influenzae, Haemophilus parainfluenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Staphylococcus aureus (28, 25, 13, 9, and 8% of isolates, respectively). Pathogens were eradicated or presumed to be eradicated in 87% (52 of 60), 91% (53 of 58), and 86% (60 of 70) of bacteriologically evaluable patients treated with cefuroxime axetil (5 days), cefuroxime axetil (10 days), and amoxicillin-clavulanate, respectively. A satisfactory clinical outcome (cure or improvement) was achieved in 82% (107 of 130), 86% (117 of 136), and 83% (130 of 157) of the clinically evaluable patients treated with cefuroxime axetil (5 days), cefuroxime axetil (10 days), and amoxicillin-clavulanate, respectively. Treatment with amoxicillin-clavulanate was associated with a significantly higher incidence of drug-related adverse events than was treatment with cefuroxime axetil for either 5 or 10 days (P = 0.001), primarily reflecting a higher incidence of drug-related gastrointestinal adverse events (37 versus 19 and 15%, respectively; P < 0.001), particularly diarrhea and nausea. These results indicate that treatment with cefuroxime axetil at 250 mg twice daily for 5 days is as effective as treatment for 10 days with either the same dose of cefuroxime axetil or amoxicillin-clavulanate at 500 mg three times daily in patients with acute bronchitis. In addition, treatment with cefuroxime axetil for either 5 or 10 days is associated with significantly fewer gastrointestinal adverse events, particularly diarrhea and nausea, than is 10-day treatment with amoxicillin-clavulanate.

Clinical comparison of cefuroxime axetil and amoxicillin/clavulanate in the treatment of patients with secondary bacterial infections of acute bronchitis.

Two independent, investigator-blinded, multicenter, randomized clinical trials compared the clinical and bacteriologic efficacy and safety of two oral antibiotics, cefuroxime axetil and amoxicillin/clavulanate, in the treatment of patients with secondary bacterial infections of acute bronchitis (hereafter denoted acute bronchitis). Three hundred sixty patients with signs and symptoms of acute bronchitis were enrolled at 22 centers and were randomly assigned to receive 10 days of treatment with either cefuroxime axetil 250 mg twice daily (BID) (n= 177) or amoxicillin/clavulanate 500 mg three times daily (TID) (n = 183). Patients were assessed for both clinical and bacteriologic responses once during treatment (at 3 to 5 days) and twice after treatment (at 1 to 3 days and at 13 to 15 days). Bacteriologic assessments were based on sputum specimen cultures obtained before treatment and, when possible, after treatment. Organisms were isolated from the pretreatment sputum specimens of 162 (45%) of 360 patients, with the primary pathogens being Haemophilus influenzae, Haemophilus parainfluenzae, Streptococcus pneumoniae, Moraxella catarrhalis, and Staphylococcus aureus (28%, 25%, 11%, 9%, and 8% of isolates, respectively). Thirty-four percent of the H influenzae isolates and 94% of the M catarrhalis isolates that were tested for beta-lactamase production were positive. A satisfactory clinical outcome (cure or improvement) was achieved in 86% (117 of 136) and 83% (130 of 157) of the clinically assessable patients treated with cefuroxime axetil or amoxicillin/clavulanate, respectively (P = 0.45). With respect to the eradication of bacterial pathogens, a satisfactory outcome (cure, presumed care, or cure with colonization) was obtained in 91% (53 of 58) and 86% (60 of 70) of bacteriologically assessable patients treated with cefuroxime axetil or amoxicillin/clavulanate, respectively (P = 0.32). Treatment with amoxicillin/clavulanate was associated with a significantly higher incidence of drug-related adverse events than was treatment with cefuroxime axetil (39% vs 23%; P = 0.001), primarily reflecting a higher incidence of drug-related gastrointestinal adverse events (37% vs 15%; P < 0.001), particularly diarrhea and nausea. Four patients in the cefuroxime axetil group and eight patients in the amoxicillin/clavulanate group withdrew from the study because of drug-related adverse events. These results indicate that cefuroxime axetil 250 mg BID is as effective as amoxicillin/clavulanate 500 mg TID in the treatment of patients with acute bronchitis but produces fewer gastrointestinal adverse events, particularly diarrhea and nausea.