Activity restriction and depression in medical patients and their caregivers: a meta-analysis

Depression commonly occurs in conjunction with a variety of medical conditions. In addition, family members who care for patients with medical diagnoses often suffer from depression. Therefore, in addition to treating illnesses, physicians and other healthcare professionals are often faced with managing secondary mental health consequences. We conducted a systematic review and meta-analysis of the association between activity restriction and depression in medical patients and their caregivers. A total of 34 studies (N = 8053) documenting the relationship between activity restriction and depression were identified for the period between January 1980 and June 2010. Effect sizes were calculated as Pearson r correlations using random-effects models. The correlation between activity restriction and depression was positive and of large magnitude (r = 0.39; 95% CI, .34-0.44). Activity restriction was most strongly correlated with depression in medical patients (r = 0.45; 95% CI, 0.42-0.48), followed by caregivers (r = 0.34; 95% CI, 0.28-0.41) and community-dwelling adults (r = 0.28; 95% CI, 0.25-0.31). Activity restriction associated with medical conditions is a significant threat to well-being and quality of life, as well as to the lives of their caregivers. Assessment and treatment of activity restriction may be particularly helpful in preventing depression.     

Does loading influence the severity of cartilage degeneration in the canine Groove‐model of OA?

Many animal models are used to study osteoarthritis (OA). In these models the role of joint loading in the development of OA is not fully understood. We studied the effect of loading on the development of OA in the canine Groove‐model. In ten female beagle dogs OA was induced in one knee according to the Groove‐model. The animals were divided in groups with and without forced‐loading. Forced‐loading was achieved by fixing the contra‐lateral limb to the trunk 3 times a week for 4 hours. After 20 weeks joint tissues of all dogs were evaluated. Subjective evaluation revealed less movement with more loading in the forced‐loading‐group compared to the group without forced‐loading. In both groups induction of OA resulted in macroscopical and microscopical OA changes as well as alterations in cartilage metabolism characteristics for OA. Although differences were small, for some parameters they were statistically significant for the forced‐loading‐group. There were no differences between the contra‐lateral healthy joints of both groups. The present study demonstrates that in the Groove‐model intensified loading is not a prerequisite for the development of OA, although it adds to some extent to the severity of the OA. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1332–1338, 2009     

Exaggerated responses to stress in the BTBR T+tf/J mouse: an unusual behavioral phenotype

This study shows that the BTBR T+tf/J mouse, a model for autism spectrum disorder (ASD), has increased levels of the stress hormone corticosterone, when compared to C57BL/6J mice. In addition, we have shown that tail suspension of the BTBR produces a heightened anxiety response in the elevated plus maze. These results suggest that the BTBR mouse is stressor-reactive exhibiting hormone responses that might predispose it to ASD.     

Pupillary responses to intranasal trigeminal and olfactory stimulation

The aim of the present study was to investigate whether pupillary responses to odorous stimuli reflect their intensity or hedonic tone. A total of 21 healthy subjects participated in the study. Using a computer-controlled olfactometer, subjects received intranasal stimuli including odors of rose (PEA; 2 concentrations), lemon and rotten eggs, plus the trigeminal irritant CO₂ (also at two concentrations). Changes in the pupil diameter were obtained ipsilaterally to the side of stimulus presentation. Both trigeminal and olfactory stimulation produced an increase in pupillary diameter. Latencies for pupillary reaction were fastest for the higher concentration of CO₂ and slowest after the presentation of PEA at the low concentration. Response amplitudes were largest in response to stimulation with CO₂ at the high concentration, while they were smallest in response to odorous stimulation with PEA. Response latencies decreased with increasing stimulus intensity. No such correlation was found for hedonic ratings and pupillary reactions. Thus, the change in the pupillary diameter indicates differences between stimulus modalities and stimulus strength, but not pleasantness or unpleasantness of the odors.     

Terminal restriction fragment length polymorphism analysis of the diversity of fecal microbiota in patients with ulcerative colitis

BACKGROUND: Terminal restriction fragment length polymorphism (T-RFLP) analysis is a powerful tool to assess the diversity of complexed microbiota. This permits rapid comparison of microbiota from many samples. In this study, we performed T-RFLP analysis of the fecal microbiota from patients with ulcerative colitis (UC). METHODS: Forty-four patients with UC (23 women and 21 men, median age 25 years) and 46 healthy individuals (25 women and 21 men, median age 34 years) were enrolled in this study. DNA was extracted from their stool samples, and the 16S rRNA genes were amplified by PCR. The PCR products were then digested with HhaI and/or MspI restriction enzymes, and the length of the T-RF was determined. RESULTS: The fecal microbial communities were classified in 8 clusters. Almost all the healthy individuals (39 of 46) were included in cluster I, and most of the UC patients could be divided into the other 7 clusters, indicating that fecal bacterial communities are different between healthy individuals and active UC patients. Some T-RFs, derived from the unclassified bacteria, Ruminococcus, Eubacterium, Fusobacterium, gammaproteobacteria, unclassified Bacteroides, and unclassified Lactobacillus, were detected in the UC patients, but not in the healthy individuals. The T-RFLP patterns were also different between the active patients and inactive (remission) patients. The T-RF derived from the unclassified bacteria, Ruminococcus and Eubacterium, and the T-RFs derived from the unclassified bacteria, Eubacterium, and Fusobacterium were predominantly detected in the active patients not the inactive patients. In contrast, the T-RFs derived from Lactobacillus and unclassified Lactobacillus were more predominant in the inactive (remission) patients. In 4 patients with proctitis, the pattern of fecal microbial diversity was very similar. CONCLUSIONS: T-RFLP analyses showed that the diversity of fecal microbiota in patients with UC was different from that in healthy individuals. Unclassified bacteria, as well as known bacteria, can contribute to alterations in the bacterial diversity of UC patients.     

Neural substrates of cognitive inflexibility after chronic cocaine exposure

Cognitive changes in addicts and animals exposed to addictive drugs have been extensively investigated over the past decades. One advantage of studying addiction using cognitive paradigms is that neural processing in addicts or drug-exposed animals can be compared to that in normal subjects. Tests of cognitive flexibility that measure the ability to change responding to a previously rewarded or punished stimulus are of potential interest in the study of addiction, because addiction can itself be viewed as an inability to change responding to stimuli previously associated with drug reward. One such test is reversal learning, which is impaired in cocaine addicts and animals that have chronically self-administered or been exposed to cocaine. A circuit including orbitofrontal cortex, basolateral amygdala and striatum subserves reversal learning. In rats that have been previously exposed to cocaine, neurons in these regions show selective and distinct changes in how they encode information during reversal learning. These changes suggest that in these rats, orbitofrontal cortex loses the ability to signal expected outcomes, and basolateral amygdala becomes inflexible in its encoding of cue significance. These changes could explain cocaine-induced impairments to cognitive flexibility and may have theoretical importance in addiction.     

Exact moment of tendon of pectoralis major muscle rupture captured on video

A powerlifting athlete ruptured his left tendon of the pectoralis major muscle while attempting to lift 160 kg in a Brazilian bench press championship. The injury seemed to occur in the concentric phase of exercise; however, the more common mechanism of rupture is during the eccentric phase. The tendon was reinserted to the humerus 3 weeks later with screws and washers. The athlete returned to competitive activities after 5 months. One year later he lifted 170 kg and won the national championship.     

Carbon dioxide suppresses macrophage superoxide anion production independent of extracellular pH and mitochondrial activity

Background

Superoxide anions released by activated macrophages during surgery are considered to be responsible for local cellular damage. Application of CO₂ pneumoperitoneum during laparoscopy affects superoxide anion release, but the underlying mechanism remains unclear and the data reported are conflicting. We investigated the direct and pH-mediated impact of CO₂ and air on macrophage superoxide anion production.

Methods

Cells of the NR 8383 rat macrophage cell line were incubated for 2 hours in 5% CO₂, 100% CO₂, and room air or pH 7.4, pH 6.5, and pH 5.5. The extracellular pH was monitored during incubation. At 0, 2, and 6 hours after incubation, the release of superoxide anions was determined fluorometrically. The mitochondrial activity was determined via the conversion of MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] during and after incubation.

Results

Extracellular pH decreased to 6.4 during incubation in a CO₂ atmosphere. The release of superoxide anions was significantly reduced immediately after CO₂ incubation. It was restored at all other time-points. Decreasing the extracellular pH to 6.5 had no effect on superoxide anion release, whereas acidification of the extracellular milieu to pH 5.5 significantly suppressed subsequent superoxide release. Mitochondrial activity was significantly decreased by CO₂ up to 2 hours and by acidic milieu up to 6 hours. Incubation in room air had no effect.

Conclusions

Incubation in CO₂ can directly suppress macrophage superoxide anion production. This effect is of short duration, fully reversible, and not correlated to changes in extracellular pH or mitochondrial activity. Air contamination does not affect macrophage superoxide anion release. We speculate that CO₂ pneumoperitoneum could attenuate the intraoperative free radical production by directly inhibiting superoxide anion release of macrophages without long-lasting suppression of macrophages and their capacity to release superoxide anions postoperatively.