Primary somatosensory cortex necessary for the perception of weight from other people's action: a continuous theta-burst TMS experiment

The presence of a network of areas in the parietal and premotor cortices, which are active both during action execution and observation, suggests that we might understand the actions of other people by activating those motor programs for making similar actions. Although neurophysiological and imaging studies show an involvement of the somatosensory cortex (SI) during action observation and execution, it is unclear whether SI is essential for understanding the somatosensory aspects of observed actions. To address this issue, we used off-line transcranial magnetic continuous theta-burst stimulation (cTBS) just before a weight judgment task. Participants observed the right hand of an actor lifting a box and estimated its relative weight. In counterbalanced sessions, we delivered sham and active cTBS over the hand region of the left SI and, to test anatomical specificity, over the left motor cortex (M1) and the left superior parietal lobule (SPL). Active cTBS over SI, but not over M1 or SPL, impaired task performance relative to sham cTBS. Moreover, active cTBS delivered over SI just before participants were asked to evaluate the weight of a bouncing ball did not alter performance compared to sham cTBS. These findings indicate that SI is critical for extracting somatosensory features (heavy/light) from observed action kinematics and suggest a prominent role of SI in action understanding

Spontaneous Clearance of Chronic HCV: The Key Ending Left in the Dark

BACKGROUND: Hepatitis C is the second leading cause of liver cirrhosis and hepatocellular carcinoma. Although the discovery of direct-acting agents made the disease curable, HCV elimination can be achieved solely by the host’s immunologic arsenal. CASE REPORT: We report the case of a 29-year-old woman with chronic hepatitis C infection - elevated transaminases, positive serology. HCV was detectable on two occasions, and histology showed mild disease - A1F1. Upon follow up and without any treatment, the patient achieved spontaneous clearance confirmed by two consecutive undetectable HCV RNA tests. Spontaneous HCV clearance rarely occurs – 0.5% per person-year. This is sometimes accompanied by special circumstances like additional disease or medical interventions. Host factors like gender and interleukin-28B polymorphisms have been known to contribute to clearance. Viral factors like HCV RNA levels are also a factor. The characteristics of host-viral interplay – age of acquisition and fibrosis stage – cannot be overlooked. CONCLUSION: All of the abovementioned factors contribute to the complex immunological interaction between virus and host and the result, although rarely can be spontaneous clearance

Minimally invasive ablative techniques of liver tumors

Само 5-15% от пациентите с НСС или с чернодробни метастази могат да бъдат подложени на чернодробна резекция, поради различни противопоказания: голям брой тумори, тумори на трудно достъпни места, недостатъчен чернодробен обем за резекция. Вариантите за перкутанно лечение могат да бъдат: Химичната аблация: инжектиране на етанол или оцетна киселина; Термалната аблация: (а) криохирургични аблация (CSA/КХА): използване на течен азот, аргон, или NO2; (б) коагулационната: използване на радиочестотен ток (RFA/РФА); Микровълнова аблация (MWA/МВ); лазерна интерстициална термотерапия (ЛИТТ) или високоинтензивен фокусиран ултразвук (HIFU/ ВФУ); Необратима електропорация (IRE).Only 5-15% of patients with HCC or liver metastases may undergo hepatic resection due to different contraindications: a large number of tumors, tumors in hard-to-reach places, insufficient hepatic volume for resection. The options for percutaneous treatment can be: Chemical Ablation: Injection of Ethanol or Acetic Acid; Thermal ablation: (a) cryosurgical ablation (CSA): use of liquid nitrogen, argon, or NO2; (b) Coagulation: Radio Frequency Ablation (RFA); Microwave ablation (MWA); Laser Interstitial Thermotherapy (LITT) or High Intensive Focused Ultrasound (HIFU); Irreversible electroporation (IRE)

Radiofrequency ablation of unresectable primary and metastatic hepatic malignancies

Отворената хирургия е златен стандарт за лечение на хепатоцелуларен карцином (НСС) и чернодробни метастази от рак на дебелото черво. Днес чернодробната резекция е все още само лечебен вариант за пациенти с рак на черния дроб, с 5-годишната преживяемост между 25-60%, в сравнение с 0% 5-годишна преживяемост без никакви лечение. Само 5-15% от пациентите с НСС или с чернодробни метастази могат да бъдат подложени на чернодробна резекция поради различни противопоказания: голям брой тумори, тумори на труднодостъпни места, недостатъчен чернодробен обем за резекция.Open surgery is a gold standard for treating hepatocellular carcinoma (HCC) and hepatic metastases of colorectal cancer. Today, liver resection is still only a radically option for patients with liver cancer, with a 5-year survival rate of 25-60%, compared with 0% 5-year survival without any treatment. Only 5-15% of patients with HCC or liver metastases may undergo hepatic resection due to different contraindications: a large number of tumors, tumors in hard-to-reach places, insufficient hepatic volume for resection

The genetic history of the Southern Arc: a bridge between West Asia and Europe

By sequencing 727 ancient individuals from the Southern Arc (Anatolia and its neighbors in Southeastern Europe and West Asia) over 10,000 years, we contextualize its Chalcolithic period and Bronze Age (about 5000 to 1000 BCE), when extensive gene flow entangled it with the Eurasian steppe. Two streams of migration transmitted Caucasus and Anatolian/Levantine ancestry northward, and the Yamnaya pastoralists, formed on the steppe, then spread southward into the Balkans and across the Caucasus into Armenia, where they left numerous patrilineal descendants. Anatolia was transformed by intra–West Asian gene flow, with negligible impact of the later Yamnaya migrations. This contrasts with all other regions where Indo-European languages were spoken, suggesting that the homeland of the Indo-Anatolian language family was in West Asia, with only secondary dispersals of non-Anatolian Indo-Europeans from the steppe

Functional connectivity of the primary somatosensory cortex and its role during action observation

Bij het observeren van andermans handelingen, activeren we een groot hersennetwerk. De algemene opvatting is dat visuele informatie eerst door het visuele systeem verwerkt wordt, waarna het “actie observatie” netwerk een mentale simulatie maakt van de geobserveerde motor handeling. Uiteindelijk helpt een dergelijke simulatie ons om informatie uit het gedrag van anderen te destilleren, dat ons helpt hen te “begrijpen”. Eén gebied waarvan we de betrokkenheid in dit netwerk nog niet goed begrijpen is de primaire sensibele cortex (SI). Dit gebied is belangrijk bij het verwerken van gevoelsstimuli. In twee fMRI experimenten hebben we laten zien dat SI communiceert met gebieden die betrokken zijn bij de mentale simulatie van handelingen, zowel tijdens observatie van handelingen als tijdens rust. We hebben in een ander gedragsexperiment ook laten zien dat na magnetische onderdrukking van de activiteit in SI deelnemers slechter zijn in het schatten van het gewicht van een doos die door een hand wordt opgetild. Deze resultaten suggereren dat we, terwijl we iemand zien handelen, niet alleen de motor activiteit simuleren, maar ook de sensaties die ermee gepaard gaan. In een laatste experiment keken deelnemers naar incomplete handelingen. De resultaten hiervan lieten zien dat verwachtingen over de beweging en de uitkomst van de handeling het motor systeem beïnvloeden. Dit resultaat suggereert dat onze hersenen niet alleen informatie uit de wereld om ons heen ontvangen, maar ook beïnvloeden hoe we onze omgeving ervaren. Op een bepaalde manier is “vrije wil” dus een illusie, omdat onze a priori verwachtingen beïnvloeden wat we zien. During the observation of actions performed by other people, our brain activates a broad network of cortical areas. It is commonly believed that information is first processed by the visual system and then the “action observation” network calculates a mental simulation of the observed motor act. Ultimately this simulation helps us to extract information from the behaviours of other people, i.e. “understand” them. One area whose involvement in this network is not yet clear is the primary somatosensory cortex (SI) which is the main brain hub to process sensory stimuli. In two fMRI experiments we have shown that during action observation and also when the brain is at rest, SI communicates with brain regions that calculate mental simulations of actions. We have also shown in another behavioural experiment that after magnetically inhibiting the functioning of SI, participants are worse at estimating the weight of a box they observe while being lifted by a hand. These results suggest that while observing somebody act we simulate not only the motor act, but also the sensations involved in the action. In one last experiment participants observed incomplete actions. Results showed that their expectations about the outcome and kinematics of the action influence their motor system. This interesting result can be interpreted as an indication that our brains do not only receive information from the outside world but also influence how we perceive the world. In a way “free will” is an illusion since our prior expectations influence what we see.

Individual Differences in the Attentional Blink The Important Role of Irrelevant Information

A well-established phenomenon in the study of attention is the attentional blink (AB): a deficit in reporting the second of two targets when it occurs 200-500 ms after the first. Although the effect has been shown to be robust in a wide variety of task conditions, we recently reported that some individuals show little or no AB, and presented psychophysiological evidence that target processing differs in nonblinkers (who do not show an AB) and blinkers (who do show an AB). Here we present evidence that the level of distractor processing and subsequent interference with target identification processes also differs between the two groups. In one task, two masked targets were centrally presented at varying temporal intervals, with or without additional distractors. In a second task, the masked targets were presented eccentrically, with or without the presence of a central sequential stream of the task-irrelevant distractors. In both cases, the presence of distractors led to an increased AB magnitude in blinkers, whereas performance for nonblinkers remained relatively unaffected. The results thus support the hypothesis that nonblinkers are more efficient in ignoring irrelevant information than blinkers