Hemispheric control of unilateral and bilateral responses to lateralized light stimuli after callosotomy and in callosal agenesis

Normally, simple digital or manual responses to a light stimulus in the right or left visual hemifields are performed faster with uncrossed hand-field combinations than with crossed hand-field combinations. Because of the organization of visual and motor pathways, the integration of uncrossed responses is assumed to occur within a single hemisphere, whereas a time-consuming inter-hemispheric transfer via the corpus callosum is considered to be necessary for the integration of crossed responses. However, callosal transfer may be dispensable for those crossed responses which can be controlled through ipsilaterally descending motor pathways by the hemisphere receiving the visual stimulus. We investigated crossed-uncrossed differences (CUDs) in speed of simple visuomotor responses to lateralized flashes in one subject with total section of the corpus callosum and two subjects with complete callosal agenesis. We recorded the reaction times as well as the premotor times, as indicated by the electromyographic latencies of the prime movers, of three types of responses: a distal response involving a thumb flexion, a proximal response chiefly involving a forearm flexion and an axial response involving a shoulder elevation. Further, the three types of responses to a single lateralised flash were performed both unilaterally and bilaterally. The three acallosal subjects showed CUDs greatly exceeding normal values on distal responses, either unilateral or bilateral, and on unilateral proximal responses. These abnormally long CUDs stood in sharp contrast to the insignificant CUDs exhibited by the same subjects on bilateral proximal responses and on unilateral and bilateral axial responses in agreement with correspondingly insignificant CUDs reported for normal subjects. These results confirm that a callosal contribution is important for the execution of fast distal and unilateral proximal responses to a visual stimulus directed to the hemisphere ipsilateral to the responding hand. By contrast, the other types of crossed responses appear to be efficiently coordinated across the midline without the aid of the corpus callosum. This is in keeping with the hypothesis that they are governed by a bilaterally distributed motor system which is preferentially activated for the execution of symmetrical bilateral movements, employing axial and proximal limb muscles.     

Changes in plasma iron levels following Carboplatin administration

Carboplatin-induced changes in plasma iron levels and the related erythropoiesis impairment were investigated in 32 neoplastic patients for a total of 64 courses of chemotherapy. Iron showed a significant increase over pretreatment levels starting from day 1 after carboplatin administration (p< 0.001). Return to pre-treatment levels was achieved on day 14. Hemoglobin decreased significantly on day 7 (p< 0.05) and further on days 14 and 21 (p< 0.001). In patients undergoing 3 consecutive cycles of chemotherapy, basal hemoglobin before the 2nd cycle was significantly lower than before the 1st (p< 0.05), whereas before the 3rd cycle the levels were similar to those before the 2nd. Hemoglobin time-course did not differ among the three cycles. No relationship was observed between maximum iron levels and hemoglobin at minimum levels, nor between pre-treatment hemoglobin levels and severity of chemotherapy-induced subacute anemia. These results suggest that neither pre-treatment hemoglobin nor the entity of iron increase are predictive of the need of blood transfusion. Moreover, the absence of correlation between iron increase and hemoglobin decrease suggests that the toxic block on erythroid maturation is not the only mechanism with which platinum compounds interfere with iron metabolism. It is possible that the bivalent platinum ion may displace competitively iron from its binding sites, either on proteins or on cells.     

Potential use of lactate for the treatment of neonatal hypoxic-ischemic encephalopathy

<正>Function of lactate:Lactate is a three-carbon molecule produced by glycolytic metabolism that is a metabolic waste product with no known use in clinical therapy.Conversely,it is a metabolite that the body should quickly guarantee the clearance.However,lactate is now recognized as a potential energy substrate,as well as an anti-inflammatory signaling molecule.These actions were first reported in adult animal models with a brain injury,including a traumatic brain injury and cerebral ische...     

Plasma PCSK9 levels and sepsis severity: an early assessment in the emergency department

Clinical and Experimental Medicine - The aim of the study is to evaluate the prognostic value of early PCSK9 levels in non-intubated septic patients admitted to the emergency department. This...     

Temporal lobe epilepsy and emotion recognition without amygdala: a case study of Urbach‐Wiethe disease and review of the literature

We describe the epilepsy features and emotion recognition abilities (recognition of basic facial emotions and recognition of emotional prosody) in a patient with Urbach‐Wiethe disease with bilateral amygdala calcifications. Our data, supported by ictal video‐EEG recording, indicated that our patient suffered from mesial temporal lobe epilepsy. Emotion recognition abilities were compared to those of healthy controls and those of patients with bilateral mesial temporal lobe epilepsy. Our patient showed a selective impairment of the recognition of facial expression of fear, whereas recognition of emotional prosody was preserved, in contrast to bilateral mesial temporal lobe epilepsy patients that presented with deficits in both domains. We also reviewed the literature on epilepsy in Urbach‐Wiethe disease (41 patients). Our findings suggest that in Urbach‐Wiethe disease, the circumscribed damage of both amygdalae results in a selective dysfunction of fearful face processing, in contrast to bilateral mesial temporal lobe epilepsy patients who present with a widespread and multimodal impairment in the judgement of emotional stimuli.     

Twisted molecular wires polarize spin currents at room temperature

A critical spintronics challenge is to develop molecular wires that render efficiently spin-polarized currents. Interplanar torsional twisting, driven by chiral binucleating ligands in highly conjugated molecular wires, gives rise to large near-infrared rotational strengths. The large scalar product of the electric and magnetic dipole transition moments (μ→ij⋅m→ij), which are evident in the low-energy absorptive manifolds of these wires, makes possible enhanced chirality-induced spin selectivity–derived spin polarization. Magnetic-conductive atomic force microscopy experiments and spin-Hall devices demonstrate that these designs point the way to achieve high spin selectivity and large-magnitude spin currents in chiral materials.

Spintronics offers exciting possibilities in applications that include information storage and magnetic sensing with reduced power consumption (1). Molecular organic semiconductors offer tremendous potential for electron spin transmission, as well as controlling spin decoherence and relaxation times (2). These opportunities derive in part from the fact that light-atom–based organic compositions have intrinsically weaker spin–orbit coupling (SOC) and hyperfine interactions than conventional inorganic semiconductors; such properties have enabled advances that include spin-polarized organic light-emitting diodes (3), organic spin valves (4), and spin-photovoltaic cells (5).While organic molecules have small SOCs, the recently discovered chirality-induced spin selectivity (CISS) effect provides a new approach to control spins in molecules (6). Numerous experiments show that chiral molecules act as spin filters in electron transport. The same is true when an electric field is applied across a chiral molecule and induces charge reorganization. Because spin polarization accompanies charge polarization in chiral molecules (7), the CISS effect provides a potential solution to resolve the technological hurdles associated with injecting spin-polarized electrons from inorganic ferromagnets into organic molecules or vice versa; commonly, in such devices, the Schottky barrier limits spin injection efficiency and drives spin depolarization (8). Importantly, in this regard, the CISS effect has been used to generate spin polarizations approaching 100% under ambient conditions, even in the absence of a magnetic field (9). Because the CISS effect enables ambient temperature control of the electron spin through applied electrical and electromagnetic fields, it bears keen relevance to quantum information science, as it provides a potential pathway to generate coherent spin states (entangled electron pairs or spin qubits).Spin-selective transmission made possible by the CISS effect has been demonstrated for chiral tunneling barriers fabricated from chiral molecules [e.g., oligopeptides (10, 11), l/d-cysteine (12), and oligonucleotides (13)], chiral nanoparticles [e.g., CdSe quantum dots (14) and chiral helicoidal three-dimensional metal organic frameworks (9)], and other materials (15, 16). Chiral organic structures that possess substantial charge mobilities and suppress spin dephasing offer the potential to realize materials that have dramatically enhanced CISS functionality. In this regard, we demonstrated recently that low-resistance molecular wires, with a mix of tunneling, hopping, and resonant transport mechanisms (17, 18), uniquely propagate spin-polarized currents (19). These exemplary compositions exploit conjugated zinc porphyrin wires (PZn_n), which manifest long spin-relaxation times (20), support highly delocalized hole and electron polaron states (21, 22), and feature extraordinarily low charge transport resistances (17, 18). In contrast to pioneering studies that have induced chirality in conjugated oligomers via H-bonding interactions (23), we demonstrate here that chiral twisted molecular wires can be engineered with conjugated PZn_n oligomers through coordination of chiral binucleating ligands; this strategy integrates both spin-polarizing and spin-propagating functionality in a single conductive organic framework, controls the handedness of the polarized spin, and thus regulates spin currents via the CISS mechanism.     

Transcranial magnetic stimulation in epileptic patients: usefulness and safety

We studied 58 patients with partial or generalized epilepsy who had transcranial magnetic stimulation (TMS) of the brain motor regions. Short-term monitoring disclosed that the stimulation did not provoke seizures or EEG changes in any patient. Long-term follow-up disclosed that the epileptic condition was not made worse by TMS. TMS, as currently used for monitoring conduction in central motor pathways, does not induce seizures in drug-treated epileptic patients.     

Adjuvant chemotherapy in gastric cancer: a meta-analysis of randomized trials and a comparison with previous meta-analyses

AIMS AND BACKGROUND: Up to now adjuvant chemotherapy after curative resection for gastric cancer (GC) has been considered an experimental approach. The results of existing phase III randomized trials comparing chemotherapy with control after surgery are controversial. Three meta-analyses have been published in recent years. It is likely that each of them presents a theoretical bias, mainly as regards the inclusion criteria of the trials. In this article we re-examine this potential bias, highlighting the differences between the present and past meta-analyses on adjuvant chemotherapy for GC. METHODS: Only randomized controlled clinical trials comparing systemic adjuvant chemotherapy with control after radical resection of GC were eligible. Total mortality was assessed as outcome measure of the treatment effect and a pooled odds ratio was calculated using the Peto-Mantel-Haenszel method. RESULTS: After the selection process 17 papers (18 comparisons) proved eligible for inclusion in the meta-analysis with a total of 3118 patients, of whom 1546 randomized to the treatment arms and 1572 to the control arms; 762 and 871 deaths occurred in the treatment and control arms, respectively. Statistical analysis suggests an absence of significant heterogeneity between the trials and a significant advantage in survival for adjuvant chemotherapy (pooled odds ratio, 0.72, 95% Cl, 0.62-0.84). CONCLUSIONS: Our meta-analysis would seem to indicate that adjuvant chemotherapy results in a significant survival advantage in patients with GC. However, this observation undoubtedly requires confirmation in large randomized controlled trials including cisplatin before adjuvant chemotherapy after curative resection for GC can be proposed for use in clinical practice.     

Ictal pattern of EEG and muscular activation in symptomatic infantile spasms: a videopolygraphic and computer analysis

PURPOSE: To investigate ictal muscular phenomena characterizing symptomatic infantile spasms (ISs) and their relation to ictal EEG. METHODS: Four children with severe encephalopathy, neurologic impairment, and refractory ISs related to different dysplastic lesions, underwent videopolygraphic recordings collecting surface electromyogram (EMG) activity from several cranial and limb muscles to evaluate the pattern of muscular recruitment, duration, and side-to-side asymmetry of ISs. Acquired data were stored for off-line analysis by a computerized polygraphic system. RESULTS: Spasms were characterized by a complex pattern of muscular activation. A constant or rostrocaudal propagation pattern was lacking in all patients. Intervals between the onset of EMG activity in different muscles in each spasm were very long: 相似文献