Keeping pain out of mind: the role of the dorsolateral prefrontal cortex in pain modulation

Frontal lobe activity during pain is generally linked to attentional processing. We addressed the question of whether 'bottom-up' processing and 'top-down' modulation of nociceptive information dissociate anatomically within the frontal lobe by using PET scanning during painful thermal stimulation of normal and capsaicin-treated skin. We showed recently that pain following normally non-painful heat stimuli on chemically irritated skin (heat allodynia) uniquely engages extensive areas of the bilateral dorsolateral prefrontal (DLPFC), ventral/orbitofrontal (VOFC) and perigenual anterior cingulate (ACC) cortices. Here, we applied principal component analysis (PCA) and multiple regression analysis to study the covariance structure of the volumes of interest (VOI) activated specifically during heat allodynia in 14 male healthy subjects and evaluated the relationship of these VOI to ratings of pain intensity and affect. Results yielded a primary principal component (PC) that correlated positively with intensity and unpleasantness and accounted for activity in the medial thalamus, bilateral anterior insula, ventral striatum, perigenual ACC and bilateral VOFC. Activities in the right and left DLPFC loaded on separate PC and correlated negatively with perceived intensity and unpleasantness. The inter-regional correlation of midbrain and medial thalamic activity was significantly reduced during high left DLPFC activity, suggesting that its negative correlation with pain affect may result from dampening of the effective connectivity of the midbrain-medial thalamic pathway. In contrast, right DLPFC activity was associated with a weakened relationship of the anterior insula with both pain intensity and affect. We propose that the DLPFC exerts active control on pain perception by modulating corticosubcortical and corticocortical pathways.

Mechanisms of placebo analgesia: rACC recruitment of a subcortical antinociceptive network

Placebo analgesia is one of the most striking examples of the cognitive modulation of pain perception and the underlying mechanisms are finally beginning to be understood. According to pharmacological studies, the endogenous opioid system is essential for placebo analgesia. Recent functional imaging data provides evidence that the rostral anterior cingulate cortex (rACC) represents a crucial cortical area for this type of endogenous pain control. We therefore hypothesized that placebo analgesia recruits other brain areas outside the rACC and that interactions of the rACC with these brain areas mediate opioid-dependent endogenous antinociception as part of a top-down mechanism. Nineteen healthy subjects received and rated painful laser stimuli to the dorsum of both hands, one of them treated with a fake analgesic cream (placebo). Painful stimulation was preceded by an auditory cue, indicating the side of the next laser stimulation. BOLD-responses to the painful laser-stimulation during the placebo and no-placebo condition were assessed using event-related fMRI. After having confirmed placebo related activity in the rACC, a connectivity analysis identified placebo dependent contributions of rACC activity with bilateral amygdalae and the periaqueductal gray (PAG). This finding supports the view that placebo analgesia depends on the enhanced functional connectivity of the rACC with subcortical brain structures that are crucial for conditioned learning and descending inhibition of nociception.

Neurophysiological evaluation of pain

Neurophysiological techniques for the evaluation of pain in humans have made important advances in the last decade. A number of features of neuroanatomy and physiology of nociception qualifies pain as a multidimensional phenomenon which is rather unique among the sensory systems and which poses a number of technical and procedural requirements for its appropriate diagnostic assessment. Various stimulation techniques to induce defined pain in humans and used in combination with the methodology of evoked electrical brain potentials and magnetic fields are presented. Most recent knowledge gathered from scalp topography and dipole source analysis of pain-relevant evoked potentials and fields is discussed. Particular emphasis is put upon laser-evoked potentials and their application for diagnosis, pathophysiological description and monitoring of patients with neurological disorders and abnormal pain states. Future perspectives in this growing field of research are discussed briefly.

Expression of R120G-alphaB-crystallin causes aberrant desmin and alphaB-crystallin aggregation and cardiomyopathy in mice

Upregulation of alphaB-crystallin (CryAB), a small heat shock protein, is associated with a variety of diseases, including the desmin-related myopathies. CryAB, which binds to both desmin and cytoplasmic actin, may participate as a chaperone in intermediate filament formation and maintenance, but the physiological consequences of CryAB upregulation are unknown. A mutation in CryAB, R120G, has been linked to a familial desminopathy. However, it is unclear whether the mutation is directly causative. We created multiple transgenic mouse lines that overexpressed either murine wild-type CryAB or the R120G mutation in cardiomyocytes. Overexpression of wild-type CryAB was relatively benign, with no increases in mortality and no induction of desmin-related cardiomyopathy even in a line in which CryAB mRNA expression was increased approximately 104-fold and the protein level increased by 11-fold. In contrast, lines expressing the R120G mutation were compromised, with a high-expressing line exhibiting 100% mortality by early adulthood. Modest expression levels resulted in a phenotype that was strikingly similar to that observed for the desmin-related cardiomyopathies. The desmin filaments in the cardiomyocytes were overtly affected, myofibril alignment was significantly impaired, and a hypertrophic response occurred at both the molecular and cellular levels. The data show that the R120G mutation causes a desminopathy, is dominant negative, and results in cardiac hypertrophy.

A phase II study of vinflunine in bladder cancer patients progressing after first-line platinum-containing regimen

A multicentre phase II trial to determine the efficacy of vinflunine as second-line therapy in patients with advanced transitional cell carcinoma (TCC) of the bladder; secondary objectives were to assess duration of response, progression-free survival (PFS) and overall survival (OS), and to evaluate the toxicity associated with this treatment. Patients had tumours that failed or progressed after first-line platinum-containing regimens for advanced or metastatic disease, or had progressive disease after platinum-containing chemotherapy given with adjuvant or neoadjuvant intent. Response and adverse events were assessed according to WHO criteria and NCI-CTC (version 2), respectively. Out of 51 patients treated with 320 mg m(-2) of vinflunine, nine patients responded to the therapy yielding an overall response rate of 18% (95% CI: 8.4-30.9%), and 67% (95%CI: 52.1-79.3%) achieved disease control (PR+SD). Of note, responses were seen in patients with relatively poor prognostic factors such as a short (<12 months) interval from prior platinum therapy (19%, including an 11% response rate in those progressing <3 months after platinum treatment), prior treatment for metastatic disease (24%), prior treatment with vinca alkaloids (14%) and visceral involvement (20%). The median duration of response was 9.1 months (95% CI: 4.2-15.0) and the median PFS was 3.0 months (95% CI: 2.4-3.8). The median OS was 6.6 months (95% CI: 4.8-7.6). The main haematological toxicity was grade 3-4 neutropenia, observed in 67% of patients (42% of cycles). Febrile neutropenia was observed in five patients (10%) and among them two were fatal. Constipation was frequently observed (but was manageable and noncumulative) and was grade 3-4 in only 8% of patients. The incidence of grade 3 nausea and vomiting was very low (4 and 6% of patients, respectively). Neither grade 3-4 sensory neuropathy nor severe venous irritation was observed. Moreover, and of importance in this particular study population, no grade 3-4 renal function impairment was observed. Vinflunine is an active agent for the treatment of platinum-pretreated bladder cancer, and these results warrant further investigation in phase III trials, either as monotherapy or in combination with other agents as treatment of advanced/metastatic TCC of the bladder.

Rescue of cardiac alpha-actin-deficient mice by enteric smooth muscle gamma-actin

The muscle actins in higher vertebrates display highly conserved amino acid sequences, yet they show distinct expression patterns. Thus, cardiac alpha-actin, skeletal alpha-actin, vascular smooth muscle alpha-actin, and enteric smooth muscle gamma-actin comprise the major actins in their respective tissues. To assess the functional and developmental significance of cardiac alpha-actin, the murine (129/SvJ) cardiac alpha-actin gene was disrupted by homologous recombination. The majority ( approximately 56%) of the mice lacking cardiac alpha-actin do not survive to term, and the remainder generally die within 2 weeks of birth. Increased expression of vascular smooth muscle and skeletal alpha-actins is observed in the hearts of newborn homozygous mutants and also heterozygotes but apparently is insufficient to maintain myofibrillar integrity in the homozygous mutants. Mice lacking cardiac alpha-actin can be rescued to adulthood by the ectopic expression of enteric smooth muscle gamma-actin using the cardiac alpha-myosin heavy chain promoter. However, the hearts of such rescued cardiac alpha-actin-deficient mice are extremely hypodynamic, considerably enlarged, and hypertrophied. Furthermore, the transgenically expressed enteric smooth muscle gamma-actin reduces cardiac contractility in wild-type and heterozygous mice. These results demonstrate that alterations in actin composition in the fetal and adult heart are associated with severe structural and functional perturbations.

Middle and long latency somatosensory evoked potentials after painful laser stimulation in patients with fibromyalgia syndrome

Ten female patients with fibromyalgia syndrome (FS) were investigated with laser evoked potentials (LEPs) after hand stimulations and compared with 10 female pain-free and age-matched control patients. FS patients exhibited significantly lower heat pain thresholds than controls (P < 0.05) and had higher amplitudes of LEP components N170 (P < 0.01) and P390 (P < 0.05) in response to intensities of 20 W (beam diameter 5 mm, duration 20 msec, wavelength 10.6 microns). N170 additionally appeared with a broader distribution over bilateral central, vertex and fronto-central leads which contrasted to the control group and studies in healthy subjects where N170 was much more restricted to central and midtemporal positions contralateral to the stimulated hand. Auditory stimuli interspersed between laser impulses that served to announce subjects to rate the perceived pain elicited auditory evoked potentials that were not different between groups indicating no differences of general vigilance level to account for observed LEP effects. P390 amplitude enhancement might indicate greater attention and cognitive processing of nociceptive stimuli in FS subjects. Effects upon N170 rather point to exogenous factors like peripheral and spinal sensitization or reduced cortical or subcortical inhibition of nociception.

Somatotopic organization of human somatosensory cortices for pain: a single trial fMRI study

The ability to locate pain plays a pivotal role in immediate defense and withdrawal behavior. However, how the brain localizes nociceptive information without additional information from somatotopically organized mechano-receptive pathways is not well understood. To investigate the somatotopic organization of the nociceptive system, we applied Thulium-YAG-laser evoked pain stimuli, which have no concomitant tactile component, to the dorsum of the left hand and foot in randomized order. We used single-trial functional magnetic resonance imaging (fMRI) to assess differential hemodynamic responses to hand and foot stimulation for the group and in a single subject approach. The primary somatosensory cortex (SI) shows a clear somatotopic organization ipsi- and contralaterally to painful stimulation. Furthermore, a differential representation of hand and foot stimulation appeared within the contralateral opercular--insular region of the secondary somatosensory cortex (SII). This result provides evidence that both SI and SII encode spatial information of nociceptive stimuli without additional information from the tactile system and highlights the concept of a redundant representation of basic discriminative stimulus features in human somatosensory cortices, which seems adequate in view of the evolutionary importance of pain perception.

Percutaneous treatment of portal venous stenosis in children and adolescents with segmental hepatic transplants: long-term results

PURPOSE

To evaluate the long-term effectiveness of the percutaneous treatment of portal venous stenoses in children and adolescents with reduced-size hepatic transplants.

MATERIALS AND METHODS

During the past 5 years, percutaneous transhepatic balloon venoplasty was attempted in 25 children and adolescents with anastomotic portal venous stenoses that occurred after reduced-size hepatic transplantation. All procedures were performed with direct puncture of the intrahepatic portal vein and with subsequent balloon dilation. Intravascular stents were deployed in patients with suboptimal results after dilation or with recurrent stenoses.

RESULTS

Percutaneous venoplasty was technically successful in 19 of 25 patients. In the remaining six patients, portal venous occlusion precluded access to the extrahepatic portal vein. Intravascular stents were deployed in 12 patients for "elastic" (n = 5) or recurrent (n = 7) stenoses. Seven patients who underwent successful venoplasty without stent placement have required no further intervention. All stents have remained patent without further intervention. Portal venous patency has been maintained for 5-61 months (mean time, 46 months) in all 19 patients.

CONCLUSION

Percutaneous treatment of portal venous stenoses is effective and long lasting in children with reduced-size hepatic transplants. In patients with elastic or recurrent lesions, portal venous stents have excellent long-term primary patency despite continued patient growth. Successful, percutaneous transhepatic venoplasty eliminates the need for surgical revision, portacaval shunting, or repeat transplantation.

Performance of the ATLAS trigger system in 2015

During 2015 the ATLAS experiment recorded [Formula: see text] of proton-proton collision data at a centre-of-mass energy of [Formula: see text]. The ATLAS trigger system is a crucial component of the experiment, responsible for selecting events of interest at a recording rate of approximately 1 kHz from up to 40 MHz of collisions. This paper presents a short overview of the changes to the trigger and data acquisition systems during the first long shutdown of the LHC and shows the performance of the trigger system and its components based on the 2015 proton-proton collision data.

Superselective microcoil embolization of colonic hemorrhage

OBJECTIVE

We evaluated therapeutic microcoil embolization in a group of patients with severe colonic hemorrhage.

MATERIALS AND METHODS

Twenty-seven patients with severe colonic bleeding due to diverticular disease (n = 19), angiodysplasia (n = 6), cecal ulcer (n = 1), or unknown cause (n = 1) underwent attempted microcoil embolization (n = 25). Microcatheters were used in all procedures, and embolization was performed at the level of the vasa recta or the marginal artery of Drummond. Branches of the superior mesenteric artery were embolized in 12 patients, branches of the inferior mesenteric artery were embolized in 12 patients, and branches of both the superior and inferior mesenteric arteries were embolized in one patient.

RESULTS

Technical success was achieved in 93% (25/27) of the procedures. However, immediate hemostasis occurred in 96% (26/27) of patients because in one failed procedure, an occlusive dissection of the inferior mesenteric artery arrested bleeding. Three patients rebled within 24 hr. One patient was treated with endoscopic cauterization, and two patients underwent right hemicolectomy. One patient who underwent right hemicolectomy for rebleeding had ischemic changes found on pathologic analysis of the resected specimen, and a second patient who underwent embolization of branches of the superior and inferior mesenteric arteries developed bowel infarction requiring left hemicolectomy. Prolonged clinical success occurred in 81% (22/27) of patients.

CONCLUSION

Therapeutic microcoil embolization for severe colonic hemorrhage is an effective and well-tolerated procedure.

Temporal and spatial dynamics of human forebrain activity during heat pain: analysis by positron emission tomography

To learn about the sequence of brain activation patterns during heat pain, we acquired positron emission tomographic (PET) brain scans at different times during repetitive heat stimulation (40 or 50 degrees C; 5-s contact) of each subject's left forearm. Early scans began at the onset of 60 s of stimulation; late scans began after 40 s of stimulation, which continued throughout the 60-s scan period (total stimulus duration 100 s). Each subject (14 normal, right-handed subjects; 10 male, 4 female; ages 18-42) used a visual analog scale to rate the perceived stimulus intensity (0 = no heat, 7 = pain threshold, 10 = barely tolerable pain) after each scan. The 40 degrees C stimulation received an average intensity rating of 2.19 +/- 1.22 (mean +/- SD) and the 50 degrees C an average rating of 8.93 +/- 1.33. During the scan sessions, subjects did not report a difference between early and late scans. To examine the effect of the duration of stimulation specifically, 8 of these subjects rated the perceived intensity of each of 20 sequential 5-s duration contact heat stimuli (40 or 50 degrees C; 100 s of stimulation). We used a graphical method to detect changes in perceived unpleasantness. There was no difference in perceived intensity or unpleasantness during the 40 degrees C stimulation. However, during 50 degrees C stimulation, perceived unpleasantness increased and subjects perceived the last five, but not the second five, stimuli as more intense than the first five stimuli. These psychophysical changes could be mediated by brain structures with increasing activity from early to late PET scans or that are active only during late scans. These structures include the contralateral M1/S1 cortex, bilateral S2 and mid-insular cortex, contralateral VP thalamus, medial ipsilateral thalamus, and the vermis and paravermis of the cerebellum. Structures that are equally active throughout stimulation (contralateral mid-anterior cingulate and premotor cortex) are less likely to mediate these psychophysical changes. Some cortical, but not subcortical, structures showed significant or borderline activation only during the early scans (ipsilateral premotor cortex, contralateral perigenual anterior cingulate, lateral prefrontal, and anterior insular cortex); they may mediate pain-related attentive or anticipatory functions. Overall, the results reveal that 1) the pattern of brain activation and the perception of heat pain both change during repetitive noxious heat stimulation, 2) cortical activity can be detected before subcortical responses appear, and 3) timing the stimulation with respect to the scan period can, together with psychophysical measurements, identify brain structures that are likely to participate in the perception of pain.

Three-dimensional helical CT of the tracheobronchial tree: evaluation of imaging protocols and assessment of suspected stenoses with bronchoscopic correlation

OBJECTIVE

To assess the accuracy of three-dimensional (3D) helical CT of normal airways, we evaluated different imaging protocols in test objects and patients. The clinical value of 3D helical CT was composed with bronchoscopy in patients with suspected stenoses, especially before and after endobronchial procedures.

SUBJECTS AND METHODS

Solid test objects--one of central airways and one of peripheral airways--were scanned and assessed for volume defects and stairstep artifacts. Fifty helical studies were performed in 36 patients. We evaluated these images for visualization of segmental bronchi; frequency of artifacts; and presence, localization, and degree of stenoses. Bronchoscopic correlation was available for 40 CT examinations. Follow-up 3D helical CT after endobronchial procedures was performed in nine patients.

RESULTS

In test objects, thin sections reduced volume artifacts. Overlapping sections mainly diminished stairstep artifacts. In vivo, overlapping sections were superior to contiguous sections for good visualization of the origin (96% versus 89%, p < .01) and of the course (75% versus 54%, p < .001) of segmental bronchi. Three-dimensional helical CT allowed us to assess accurately 36 of 36 central stenoses that were seen on bronchoscopy; however, on 3D helical CT, we missed two of three segmental stenoses. At bronchoscopy, 18 stenoses could not be passed, whereas 3D helical CT provided details for possible endobronchial procedures: length of stenosis, patency (12/18), and spatial orientation of distal bronchi. Follow-up 3D helical CT documented the efficacy of endobronchial treatment.

CONCLUSION

Three-dimensional helical CT based on thin overlapping sections accurately visualized the normal airways down to the origin of the segmental bronchi and central stenoses. When it complements bronchoscopy, 3D helical CT allows visualization beyond stenoses, supports planning of endobronchial procedures, and may even substitute for bronchoscopy after endobronchial procedures.

Abnormal cardiac structure and function in mice expressing nonphosphorylatable cardiac regulatory myosin light chain 2

A role for myosin phosphorylation in modulating normal cardiac function has long been suspected, and we hypothesized that changing the phosphorylation status of a cardiac myosin light chain might alter cardiac function in the whole animal. To test this directly, transgenic mice were created in which three potentially phosphorylatable serines in the ventricular isoform of the regulatory myosin light chain were mutated to alanines. Lines were obtained in which replacement of the endogenous species in the ventricle with the nonphosphorylatable, transgenically encoded protein was essentially complete. The mice show a spectrum of cardiovascular changes. As previously observed in skeletal muscle, Ca(2+) sensitivity of force development was dependent upon the phosphorylation status of the regulatory light chain. Structural abnormalities were detected by both gross histology and transmission electron microscopic analyses. Mature animals showed both atrial hypertrophy and dilatation. Echocardiographic analysis revealed that as a result of chamber enlargement, severe tricuspid valve insufficiency resulted in a detectable regurgitation jet. We conclude that regulated phosphorylation of the regulatory myosin light chains appears to play an important role in maintaining normal cardiac function over the lifetime of the animal.

Diagnosis and antimicrobial therapy of lung infiltrates in febrile neutropenic patients (allogeneic SCT excluded): updated guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Up to 25% of patients with profound neutropenia lasting for >10 days develop lung infiltrates, which frequently do not respond to broad-spectrum antibacterial therapy. While a causative pathogen remains undetected in the majority of cases, Aspergillus spp., Pneumocystis jirovecii, multi-resistant Gram-negative pathogens, mycobacteria or respiratory viruses may be involved. In at-risk patients who have received trimethoprim-sulfamethoxazole (TMP/SMX) prophylaxis, filamentous fungal pathogens appear to be predominant, yet commonly not proven at the time of treatment initiation. Pathogens isolated from blood cultures, bronchoalveolar lavage (BAL) or respiratory secretions are not always relevant for the etiology of pulmonary infiltrates and should therefore be interpreted critically. Laboratory tests for detecting Aspergillus galactomannan, β-D-glucan or DNA from blood, BAL or tissue samples may facilitate the diagnosis; however, most polymerase chain reaction assays are not yet standardized and validated. Apart from infectious agents, pulmonary side-effects from cytotoxic drugs, radiotherapy or pulmonary involvement by the underlying malignancy should be included into differential diagnosis and eventually be clarified by invasive diagnostic procedures. Pre-emptive treatment with mold-active systemic antifungal agents improves clinical outcome, while other microorganisms are preferably treated only when microbiologically documented. High-dose TMP/SMX is first choice for treatment of Pneumocystis pneumonia, while cytomegalovirus pneumonia is treated primarily with ganciclovir or foscarnet in most patients. In a considerable number of patients, clinical outcome may be favorable despite respiratory failure, so that intensive care should be unrestrictedly provided in patients whose prognosis is not desperate due to other reasons.

Muon reconstruction performance of the ATLAS detector in proton-proton collision data at [Formula: see text]=13 TeV

This article documents the performance of the ATLAS muon identification and reconstruction using the LHC dataset recorded at [Formula: see text] TeV in 2015. Using a large sample of [Formula: see text] and [Formula: see text] decays from 3.2 fb[Formula: see text] of pp collision data, measurements of the reconstruction efficiency, as well as of the momentum scale and resolution, are presented and compared to Monte Carlo simulations. The reconstruction efficiency is measured to be close to [Formula: see text] over most of the covered phase space ([Formula: see text] and [Formula: see text] GeV). The isolation efficiency varies between 93 and [Formula: see text] depending on the selection applied and on the momentum of the muon. Both efficiencies are well reproduced in simulation. In the central region of the detector, the momentum resolution is measured to be [Formula: see text] ([Formula: see text]) for muons from [Formula: see text] ([Formula: see text]) decays, and the momentum scale is known with an uncertainty of [Formula: see text]. In the region [Formula: see text], the [Formula: see text] resolution for muons from [Formula: see text] decays is [Formula: see text] while the precision of the momentum scale for low-[Formula: see text] muons from [Formula: see text] decays is about [Formula: see text].