An enigmatic new tapeworm, Litobothrium aenigmaticum, sp. nov. (Platyhelminthes : Cestoda : Litobothriidea), from the pelagic thresher shark with comments on development of known Litobothrium species

An enigmatic new tapeworm is described from pelagic thresher sharks in México and Taiwan. While lsrRNA (D1-D3) data robustly place it in the Litobothriidea, it bears essentially no morphological resemblance to other members of the order. Instead it superficially resembles the freshwater fish-inhabiting Caryophyllidea. Its scolex consists of a simple dome-shaped scolex proper and an extensive cephalic peduncle housing four distinct tissue types. It is hyperapolytic, thus reproductive anatomy is unknown. Developmental data show typical litobothriideans bear basic elements of their adult scolex upon entering the definitive host, undermining the notion that the new cestode represents a distinct litobothriidean life cycle stage. Scanning electron microscopy revealed the new species shares bands of distinctive microtriches with its congeners. In combination these data justify establishment of Litobothrium aenigmaticum, sp. nov.; the generic, familial and ordinal diagnoses are emended accordingly. Unlike typical litobothriideans, each worm is associated with a mucosal expansion at its attachment site, like those seen in some caryophyllideans. This pathological change may represent a worm-induced host response serving to reinforce attachment of the simple scolex to the mucosa. If so, the convergence of this litobothriidean on a morphology like that seen in the distantly related Caryophyllidea is a result of similarity in mode of attachment.

S1 is associated with chronic low back pain: a functional and structural MRI study

A fundamental characteristic of neural circuits is the capacity for plasticity in response to experience. Neural plasticity is associated with the development of chronic pain disorders. In this study, we investigated 1) brain resting state functional connectivity (FC) differences between patients with chronic low back pain (cLBP) and matched healthy controls (HC); 2) FC differences within the cLBP patients as they experienced different levels of endogenous low back pain evoked by exercise maneuvers, and 3) morphometric differences between cLBP patients and matched HC. We found the dynamic character of FC in the primary somatosensory cortex (S1) in cLBP patients, i.e., S1 FC decreased when the patients experienced low intensity LBP as compared with matched healthy controls, and FC at S1 increased when cLBP patients experienced high intensity LBP as compared with the low intensity condition. In addition, we also found increased cortical thickness in the bilateral S1 somatotopically associated with the lower back in cLBP patients as compared to healthy controls. Our results provide evidence of structural plasticity co-localized with areas exhibiting FC changes in S1 in cLBP patients.

Transient impairments in single muscle fibre contractile function after prolonged cycling in elite endurance athletes

AIM

Prolonged muscle activity impairs whole-muscle performance and function. However, little is known about the effects of prolonged muscle activity on the contractile function of human single muscle fibres. The purpose of this study was to investigate the effects of prolonged exercise and subsequent recovery on the contractile function of single muscle fibres obtained from elite athletes.

METHODS

Nine male triathletes (26 ± 1 years, 68 ± 1 mL O2  min(-1) kg(-1) , training volume 16 ± 1 h week(-1) ) performed 4 h of cycling exercise (at 73% of HRmax ) followed by 24 h of recovery. Biopsies from vastus lateralis were obtained before and following 4 h exercise and following 24 h recovery. Measurements comprised maximal Ca(2+) -activated specific force and Ca(2+) sensitivity of slow type I and fast type II single muscle fibres, as well as cycling peak power output.

RESULTS

Following cycling exercise, specific force was reduced to a similar extent in slow and fast fibres (-15 and -18%, respectively), while Ca(2+) sensitivity decreased in fast fibres only. Single fibre-specific force was fully restored in both fibre types after 24 h recovery. Cycling peak power output was reduced by 4-9% following cycling exercise and fully restored following recovery.

CONCLUSION

This is the first study to demonstrate that prolonged cycling exercise transiently impairs specific force in type I and II fibres and decreases Ca(2+) sensitivity in type II fibres only, specifically in elite endurance athletes. Further, the changes in single fibre-specific force induced by exercise and recovery coincided temporally with changes in cycling peak power output.

Electromagnetically induced transparency in a diamond spin ensemble enables all-optical electromagnetic field sensing

We use electromagnetically induced transparency (EIT) to probe the narrow electron-spin resonance of nitrogen-vacancy centers in diamond. Working with a multipass diamond chip at temperatures 6-30 K, the zero-phonon absorption line (637 nm) exhibits an optical depth of 6 and inhomogeneous linewidth of ~30 GHz FWHM. Simultaneous optical excitation at two frequencies separated by the ground-state zero-field splitting (2.88 GHz) reveals EIT resonances with a contrast exceeding 6% and FWHM down to 0.4 MHz. The resonances provide an all-optical probe of external electric and magnetic fields with a projected photon-shot-noise-limited sensitivity of 0.2 V/cm/√[Hz] and 0.1 nT/√[Hz], respectively. Operation of a prototype diamond-EIT magnetometer measures a noise floor of ~/<1 nT/√[Hz] for frequencies above 10 Hz and Allan deviation of 1.3±1.1 nT for 100 s intervals. The results demonstrate the potential of diamond-EIT devices for applications ranging from quantum-optical memory to precision measurement and tests of fundamental physics.

The parasite-host interface in the zonetail butterfly ray, Gymnura zonura (Bleeker), infected with Hexacanalis folifer (Cestoda: Lecanicephalidea)

A wild-caught specimen of the zonetail butterfly ray, Gymnura zonura (Bleeker), harboured numerous specimens of Hexacanalis folifer Cielocha & Jensen, 2011 (Systematic Parasitology, 79, 1-16; Cestoda: Lecanicephalidea) within its spiral intestine. The cestodes were primarily attached in single rows along the base of mucosal folds, each associated with a nodular mucosal thickening. Microscopically, the scolex was embedded within the submucosa and muscularis; the attachment sites were marked by ulceration and necro-proliferative inflammation demarcating the parasite from normal host tissues. Physical attachment of the cestode was restricted to the anterior portion of its scolex where presumed tegumental secretions from the apical organ contributed to a cementing intermediate layer blending with necrotic host cells. The presence of tegumental differentiation between the apical organ and the scolex proper, associated with presumed different roles in attachment, correlated with ultrastructural observations of the surface modifications on the scolex. Despite the locally severe pathological change, insignificant morbidity owing to this particular host-parasite relationship is suggested.

Functional connectivity of the frontoparietal network predicts cognitive modulation of pain

The experience of pain can be significantly influenced by expectancy (predictive cues). This ability to modulate pain has the potential to affect therapeutic analgesia substantially and constitutes a foundation for nonpharmacological pain relief. In this study, we investigated (1) brain regions involved in visual cue modulation of pain during anticipation of pain, pain administration, and pain rating; and (2) the association between pretest resting state functional connectivity and the magnitude of cue effects on pain ratings. We found that after cue conditioning, visual cues can significantly modulate subjective pain ratings. Functional magnetic resonance imaging results suggested that brain regions pertaining to the frontoparietal network (prefrontal and parietal cortex) and a pain/emotion modulatory region (rostral anterior cingulate cortex) are involved in cue modulation during both pain anticipation and administration stage. Most interestingly, we found that pretest resting state functional connectivity between the frontoparietal network (as identified by independent component analysis) and the rostral anterior cingulate cortex/medial prefrontal cortex was positively associated with cue effects on pain rating changes. We believe that these findings will shed new light on our understanding of variable cue/expectancy effects across individuals and how the intrinsic connectivity of the brain may influence expectancy-induced modulation of pain.

[Evidence-based medicine in surgical practice - locating clinical studies and systematic reviews by searching the Medline database]

BACKGROUND

Every day approximately 75 clinical trials and 11 systematic reviews are published in the health-care intervention and medical field. Due to this growing number of publications it is a challenge for every practicing clinician to keep track with the latest research. The implementation of new and effective diagnostic and therapeutic interventions into daily clinical routine may thus be delayed. Conversely, ineffective or even harmful interventions might still be in use. Decision-making in evidence-based medicine (EBM) requires consideration of the most recent high quality evidence. Randomised controlled trials (RCTs) are regarded as the "gold standard" to prove the efficacy of surgical interventions in patient-oriented research. Systematic reviews combine results from RCTs by summarising single RCTs which answer a particular clinical question. Some basic knowledge in systematic literature searching is required and helpful for detecting relevant publications.

MATERIAL AND METHODS

This article shows various possibilities for locating clinical studies and systematic reviews in the database Medline on the basis of illustrative step-by-step instructions. RESULTS AND CONCLUSION. Depending on the aim and topic of the literature search, the time required for the task may vary. In routine practice, a systematic literature search is unrealistic in most cases. Clinicians in need of a quick update of current evidence on a certain clinical topic may make use of up-to-date systematic reviews. During a systematic literature search, different approaches and strategies might be necessary.

Synthetic lethal screening with small-molecule inhibitors provides a pathway to rational combination therapies for melanoma

Recent data show that extracellular signals are transmitted through a network of proteins rather than hierarchical signaling pathways, suggesting that the inhibition of a single component of a canonical pathway is insufficient for the treatment of cancer. The biologic outcome of signaling through a network is inherently more robust and resistant to inhibition of a single network component. In this study, we conducted a functional chemical genetic screen to identify novel interactions between signaling inhibitors that would not be predicted on the basis of our current understanding of signaling networks. We screened over 300 drug combinations in nine melanoma cell lines and have identified pairs of compounds that show synergistic cytotoxicity. The synergistic cytotoxicities identified did not correlate with the known RAS and BRAF mutational status of the melanoma cell lines. Among the most robust results was synergy between sorafenib, a multikinase inhibitor with activity against RAF, and diclofenac, a nonsteroidal anti-inflammatory drug (NSAID). Drug substitution experiments using the NSAIDs celecoxib and ibuprofen or the MAP-ERK kinase inhibitor PD325901 and the RAF inhibitor RAF265 suggest that inhibition of COX and mitogen-activated protein kinase signaling are targets for the synergistic cytotoxicity of sorafenib and diclofenac. Cotreatment with sorafenib and diclofenac interrupts a positive feedback signaling loop involving extracellular signal-regulated kinase, cellular phospholipase A2, and COX. Genome-wide expression profiling shows synergy-specific downregulation of survival-related genes. This study has uncovered novel functional drug combinations and suggests that the underlying signaling networks that control responses to targeted agents can vary substantially, depending on unexplored components of the cell genotype.

Acceptance and commitment therapy for fibromyalgia: A randomized controlled trial

Background

Recent developments within cognitive behavior therapy (CBT) have emphasized the utility of acceptance and mindfulness strategies, contrasting interventions focused on reduction or control of symptoms. A study of fMRI changes after CBT in females with fibromyalgia (FM) has been performed and results are presented elsewhere (under review). The aim of the present study was evaluate the effectiveness of Acceptance and Commitment Therapy (ACT)-based intervention for patient diagnosed with FM in comparison with a wait-list control

Method

Female patients aged 18–55 years, fulfilling the American College of Rheumatology classification criteria for FM, and with a weekly self-reported average pain intensity of >40 (VAS 0–100) were considered eligible for inclusion. Participants completed a set of questionnaires prior to treatment, immediately following the treatment and at follow 3–4 months post treatment. Primary outcome variable was pain disability (PDI). FIQ, SF36, SES, STAI, pain intensity, BDI, PIPS (psychological inflexibility in pain scale) were also used. The ACT-intervention consisted of twelve weekly group sessions, ten with psychologist and two with pain physician. Treatment was evaluated and mediation analyses were performed.

Results

Primary outcome measure (PDI): A significant improvement in pain disability for ACT in relation to the control condition, p < 0.001. Secondary outcome measures: ACT showed significant improvement in mental health quality of life, self-efficacy, depression, and anxiety. Consistent with hypotheses, ACT did not result in significant changes in either physical quality of life or pain intensity. Mediation analyses: A decrease in psychological inflexibility from pre to post assessments significantly mediated the improvement in pain disability.

Conclusion

The present study supports the utility of using a relatively brief ACT intervention in a group format for women diagnosed with fibromyalgia, and data suggests a mediating function on improvements in psychological flexibility.

Temperature- and magnetic-field-dependent longitudinal spin relaxation in nitrogen-vacancy ensembles in diamond

We present an experimental study of the longitudinal electron-spin relaxation time (T1) of negatively charged nitrogen-vacancy (NV) ensembles in diamond. T1 was studied as a function of temperature from 5 to 475 K and magnetic field from 0 to 630 G for several samples with various NV and nitrogen concentrations. Our studies reveal three processes responsible for T1 relaxation. Above room temperature, a two-phonon Raman process dominates; below room temperature, we observe an Orbach-type process with an activation energy of 73(4) meV, which closely matches the local vibrational modes of the NV center. At yet lower temperatures, sample dependent cross-relaxation processes dominate, resulting in temperature independent values of T1 from milliseconds to minutes. The value of T1 in this limit depends sensitively on the magnetic field and can be tuned by more than 1 order of magnitude.

Increased steady-state VO2 and larger O2 deficit with CO2 inhalation during exercise

AIM

To examine whether inhalation of CO(2) -enriched gas would increase steady-state VO(2) during exercise and enlarge O(2) deficit.

METHODS

Ten physically active men (VO(2) 53.7 ± 3.6 mL min(-1) kg(-1) ; x ± SD) performed transitions from low-load cycling (baseline; 40 W) to work rates representing light (≈ 45% VO(2); 122 ± 15 W) and heavy (≈ 80% VO(2); 253 ± 29 W) exercise while inhaling normal air (air) or a CO(2) mixture (4.2% CO(2) , 21% O(2) , balance N(2) ). Gas exchange was measured with Douglas bag technique at baseline and at min 0-2, 2-3 and 5-6.

RESULTS

Inhalation of CO(2) -enriched air consistently induced respiratory acidosis with increases in PCO(2) and decreases in capillary blood pH (P < 0.01). Hypercapnic steady-state VO(2) was on average about 6% greater (P < 0.01) than with air in both light and heavy exercise, presumably because of increased cost of breathing (ΔVE 40-50 L min(-1) ; P < 0.01), and a substrate shift towards increased lipid oxidation (decline in R 0.12; P < 0.01). VO(2) during the first 2 min of exercise were not significantly different whereas the increase in VO(2) from min 2-3 to min 5-6 in heavy exercise was larger with CO(2) than with air suggesting a greater VO(2) slow component. As a result, O(2) deficit was greater with hypercapnia in heavy exercise (2.24 ± 0.51 L vs. 1.91 ± 0.45 L; P < 0.05) but not in light (0.64 ± 0.21 L vs. 0.54 ± 0.20 L; ns).

CONCLUSION

Inhalation of CO(2)-enriched air and the ensuing respiratory acidosis increase steady-state VO(2) in both light and heavy exercise and enlarges O(2) deficit in heavy exercise.

Slide-based ergometer rowing: effects on force production and neuromuscular activity

Force production profile and neuromuscular activity during slide-based and stationary ergometer rowing at standardized submaximal power output were compared in 14 male and 8 female National Team rowers. Surface electromyography (EMG) was obtained in selected thoracic and leg muscles along with synchronous measurement of handle force and rate of force development (RFD). Compared to stationary conditions, slide-based peak force decreased by 76 (57-95) N (mean 95% CI) in males (P < 0.001) and 20 (8-31) N (P < 0.05) in females. Stroke rate increased (+10.7%) and late-phase RFD decreased (-20.7%) in males (P < 0.05). Neuromuscular activity in m. vastus lateralis decreased in the initial drive phase from 59% to 51% of EMG max in males and from 57% to 52% in females (P < 0.01-0.05), while also decreasing in the late recovery phase from 20% to 7% in males and 17% to 7% in females (P < 0.01). Peak force and maximal neuromuscular activity in the shoulder retractors always occurred in the second quartile of the drive phase. In conclusion, peak force and late-phase RFD (males) decreased and stroke rate increased (males) during slide-based compared to stationary ergometer rowing, potentially reducing the risk of overuse injury. Neuromuscular activity was more affected in leg muscles than thoracic muscles by slide-based ergometer rowing.