Acute exercise modulates BDNF and pro-BDNF protein content in immune cells

PURPOSE

Although several studies have shown that immune cells stimulated by in vitro stress are capable to produce neurotrophins, there is still no evidence whether physiological stress, such as exercise, can modulate the in vivo levels of brain-derived neurotrophic factor (BDNF) in peripheral blood mononuclear cells (PBMCs).

METHODS

This work investigated whether acute exercise modulates the expression of BDNF, pro-BDNF, and p75(NTR) in the PBMCs of 10 healthy young men who performed a cycling incremental test to exhaustion (MAX) or exercised at individual anaerobic threshold (IAT). The PBMC expression of stress response proteins and the level of circulating BDNF, vascular endothelial growth growth factor, platelet-derived growth factor subunit B, basic fibroblast growth factor pro-inflammatory, and anti-inflammatory cytokines were analyzed as well.

RESULTS

A major finding is that both sessions of acute exercise regulated the content of BDNF isoforms within PBMCs in a manner related to the physiological stress exerted. Although the pro-BDNF increased after both MAX and IAT protocols, BDNF showed a kinetics dependent on exercise type: MAX induced a 54% protein increase immediately after exercise, followed by a significant drop 60 min after its conclusion (38% lower than the baseline). Differently, in the IAT, BDNF increased significantly up to 75% from the baseline throughout the recovery phase. All physiological parameters, as well as the p75(NTR) receptor and the stress-inducible proteins, were also differently regulated by the two exercise conditions.

CONCLUSIONS

These data supported the hypothesis that PBMCs might produce and secrete BDNF isoforms, as well as modulate the proteins p75(NTR) , Bcl-xL, hsp90, hsp27, and αB-crystallin, as part of the physiological stress response induced by acute exercise, offering a novel example of bidirectional interaction between nervous and immune systems.

Comparison of Alternaria spp. collected in Italy from apple with A. mali and other AM-toxin producing strains

Since 1999, a disease of apple caused by an Alternaria sp. has been affecting orchards in northern Italy resulting in necrotic spots on leaves and on fruit. Forty-four single-spored isolates were obtained from diseased plant materials to investigate the diversity of this fungus in Italy and to compare these isolates to isolates of Alternaria associated with apple disease in previous studies, including A. mali, causal agent of apple blotch. All isolates, including the reference strains, were tested for pathogenicity utilizing in vitro bioassays on detached leaf or on fruit ('Golden Delicious'). In addition, morphological characterizations were conducted describing both the three-dimensional sporulation pattern and the colony morphology of each isolate. In order to assess the genetic diversity within the Italian Alternaria population, sequence characterization of specific loci and anonymous regions (endoPG, OPA1-3, OPA2-1, and OPA10-2) and genetic fingerprinting based on amplified fragment length polymorphism and inter simple sequence repeat markers were performed. The single spore isolates exhibited differential pathogenicity, which did not correlate with the morphological groupings or to groupings defined by molecular approaches. Moreover, 10 pathogenic isolates out of the 44 single-spored tested were positive for the host-specific AM-toxin gene based upon polymerase chain reaction amplification using specific primers for the AM-toxin gene. This suggests that the production of the AM-toxin may be involved in pathogenesis by some of the Italian isolates of A. alternata from apple. However, this research also suggests that a number of different Alternaria genotypes and morphotypes may be responsible for the apple disease in Italy and that a single taxon cannot be defined as the sole causal agent.

Intermittent maximal exercise improves attentional performance only in physically active students

BACKGROUND AND AIMS

Regular physical activity participation seems to be linked to brain metabolism and to be one factor responsible for different effects of high intensity exercise on cognition. Due to this, we investigated the effect of an intermittent maximal exercise intervention on a neuropsychological test requiring sustained and selective attention in a group of low and high physically active subjects.

METHOD

Forty six healthy students (age: M = 23.11, SD = 2.60 years) performed in a cross-over design an intermittent incremental exercise until they reached their maximal heart rate (HR Max; intervention condition) or rested for the same duration (control condition) followed by the administration of the d2-test.

RESULTS

A significant interaction between physical activity participation level and exercise effect on cognitive performance emerged, with only the more physically active participants improving the performance in the cognitive test after the intervention.

CONCLUSION

These data extend the current knowledge base by showing that a higher participation rate in physical activity may lead to neurobiological adaptations that facilitate selected cognitive processes (i.e., attention) after high exercise intensities.

Low-technology exercise test in the preoperative evaluation of lung resection candidates

Exercise tests are increasingly used in the preoperative functional evaluation of lung resection candidates. Low-technology exercise tests include six minute walking, shuttle walking and stair climbing. Conflicting evidence has been reported regarding 6 minute walking test. This test should not be used to select patients for lung resection. An incremental shuttle walk test is easier to replicate than 6 minute walking test. Most patients achieving 25 shuttles or 400 m have a maximum oxygen consumption measured at cardiopulmonary exercise test greater than 15 l/Kg/min. Although this test tends to underestimate performance at the lower range compared to peak oxygen consumption it can be used a screening test before lung resection. Excluding patients from operation based on this test alone is however not recommended and a formal cardiopulmonary exercise test should be always used in those walking less than 400 m. Stair climbing has been extensively studied in thoracic surgery. Several studies have found that poor performance in this test is indicative of cardiopulmonary complications and mortality after lung resection. In particular, climbing less than 12 m represents very high risk, whereas climbing more than 22 m is associated with a favourable outcome. Recent guidelines recommend referring all patients climbing lower than 22 m to cardiopulmonary exercise test. Stair climbing can be used as a screening test in cases cardiopulmonary exercise test is not readily available. In general, patients climbing more than 22 m can proceed to surgery without further evaluation.

Morphological and immunohistochemical features of brown adipocytes and preadipocytes in a case of human hibernoma

BACKGROUND AND AIM

The role of brown adipose tissue physiology and pathology in humans is debated. A greater knowledge of its developmental aspects could play a pivotal role in devising treatments for obesity and diabetes.

METHODS AND RESULTS

Tissue from a rare case of hibernoma, removed from a 17-year-old boy, was examined by light and electron microscopy, morphometry and immunohistochemistry. The tumour was well vascularised and innervated and contained mature adipocytes with the characteristics of both brown and white adipocytes. Numerous, poorly differentiated cells resembling brown adipocyte precursors were seen in a pericytic position in close association with the capillary wall. On immunohistochemistry mature brown adipocytes were seen to express the marker protein UCP1. On morphometry the intensity of uncoupling protein 1 (UCP1) immunostaining varied in relation to the morphological features of adipocytes: the "whiter" their appearance, the weaker their UCP1 immunoreactivity.

CONCLUSIONS

Our data suggest that in humans, as in rodents, brown adipocyte precursors arise in close association with vessel walls and that intermediate forms between white and brown adipocytes can also be documented in human adults.

ERS/ESTS clinical guidelines on fitness for radical therapy in lung cancer patients (surgery and chemo-radiotherapy)

A collaboration of multidisciplinary experts on the functional evaluation of lung cancer patients has been facilitated by the European Respiratory Society (ERS) and the European Society of Thoracic Surgery (ESTS), in order to draw up recommendations and provide clinicians with clear, up-to-date guidelines on fitness for surgery and chemo-radiotherapy. The subject was divided into different topics, which were then assigned to at least two experts. The authors searched the literature according to their own strategies, with no central literature review being performed. The draft reports written by the experts on each topic were reviewed, discussed and voted on by the entire expert panel. The evidence supporting each recommendation was summarised, and graded as described by the Scottish Intercollegiate Guidelines Network Grading Review Group. Clinical practice guidelines were generated and finalized in a functional algorithm for risk stratification of the lung resection candidates, emphasising cardiological evaluation, forced expiratory volume in 1 s, systematic carbon monoxide lung diffusion capacity and exercise testing. Contrary to lung resection, for which the scientific evidences are more robust, we were unable to recommend any specific test, cut-off value, or algorithm before chemo-radiotherapy due to the lack of data. We recommend that lung cancer patients should be managed in specialised settings by multidisciplinary teams.

Epidural local anesthetic plus corticosteroid for the treatment of cervical brachial radicular pain: single injection versus continuous infusion

BACKGROUND

Efficacy of epidural local anesthetics plus steroids for the treatment of cervicobrachial pain is uncertain.

METHODS

A prospective study randomized 160 patients with cervicobrachial pain resistant to conventional therapy. Patients were divided into 4 groups on the basis of the time between pain onset and treatment initiation: group A, 40 patients with pain onset 15 to 30 days; group B, 40 patients with pain from 31 to 60 days; group C, 40 patients, 61 to 180 days; and group D, 40 patients with pain >180 days. Patients of each group were randomized to receive an epidural block with bupivacaine and methylprednisolone at intervals of 4 to 5 days (Single injection) or continuous epidural bupivacaine every 6, 12, or 24 hours plus methylprednisolone every 4 to 5 days (Continuos epidural). The maximum duration of treatment (9 blocks in Single injection, and 30 days in Continuos epidural) was dependent on achieving Pain Control (PC) > or =80% [PC is defined by this formulae: (100) (VAS(initial)-VAS(final))/VAS(initial)]. Follow-up at 1 month and 6 months compared PC and the number of pain-free hours of sleep.

RESULTS

One hundred forty-one patients completed the study. The 4 groups had similar characteristics. At the 1-month and 6-month follow-up analysis based on the time between pain onset and treatment initiation showed that patients of group D, who received the Continuous epidural treatment, had significantly greater PC and significantly more pain-free hours of sleep compared with similar patients in Single injection.

CONCLUSIONS

Therapy with continuous epidural local anesthetic and methylprednisolone provides better control of chronic cervicobrachial pain compared with Single injection. These results are discussed with respect to the possible mechanism of action of the drugs and may relate to the physiopathologic mechanisms associated with neuronal plasticity that result in chronic pain.