298 research outputs found
Repeated Intracarotid Amobarbital Tests
Rationale:Our goal was to determine the frequency of repeated intracarotid amobarbital test (IAT) at our center and to estimate the retest reliability of the IAT for both language and memory lateralization.
Methods: A total of 1,249 consecutive IATs on 1,190 patients were retrospectively reviewed for repeat tests.
Results: In 4% of patients the IAT was repeated in order to deliver satisfactory information on either language or memory lateralization. Reasons for repetition included obtundation and inability to test for memory lateralization, inability to test for language lateralization, no hemiparesis during first test, no aphasia during first test, atypical vessel filling, and bleeding complications from the catheter insertion site. Language lateralization was reproduced in all but one patient. Repeated memory test results were less consistent across tests, and memory lateralization was unreliable in 63% of the patients.
Discussion: In spite of test limitations by a varying dose of amobarbital, crossover of amobarbital from one side to the other, testing of both hemispheres on the same day, practice effects, unblinded observers, fluctuating cooperation of the patients, and a biased sample of patients language lateralization was reproduced in all but one patient. In contrast, repeated memory test results were frequently contradictory. Memory results on IAT therefore seem much less robust than the results of language testing. Gain of reliable information versus the risks of complications and failed tests has to be considered when a patient is subjected to an IAT
Virus-induced hepatocellular carcinomas cause antigen-specific local tolerance
T cell surveillance is often effective against virus-associated tumors because of their high immunogenicity. It is not clear why surveillance occasionally fails, particularly against hepatitis B virus- or hepatitis C virus-associated hepatocellular carcinoma (HCC). We established a transgenic murine model of virus-induced HCC by hepatocyte-specific adenovirus-induced activation of the oncogenic SV40 large T antigen (TAg). Adenovirus infection induced cytotoxic T lymphocytes (CTLs) targeted against the virus and TAg, leading to clearance of the infected cells. Despite the presence of functional, antigen-specific T cells, a few virus-infected cells escaped immune clearance and progressed to HCC. These cells expressed TAg at levels similar to HCC isolated from neonatal TAg-tolerant mice, suggesting that CTL clearance does not select for cells with low immunogenicity. Virus-infected mice revealed significantly greater T cell infiltration in early-stage HCC compared with that in late-stage HCC, demonstrating progressive local immune suppression through inefficient T cell infiltration. Programmed cell death protein-1 (PD-1) and its ligand PD-L1 were expressed in all TAg-specific CD8+ T cells and HCC, respectively, which contributed to local tumor-antigen-specific tolerance. Thus, we have developed a model of virus-induced HCC that may allow for a better understanding of human HCC
Memory Performance is Related to Language Dominance as Determined by the intracarotid amobarbital procedure
Objective The goal of this study was to explore the relationship between language and memory lateralization in patients with epilepsy undergoing the intracarotid amobarbital procedure. Methods In 386 patients, language lateralization and memory lateralization as determined by laterality index (LI) were correlated with each other. Results Language lateralization and memory lateralization were positively correlated (r = 0.34, P \u3c 0.01). Correlations differed depending on the presence and type of lesion (χ2 = 7.98, P \u3c 0.05). LIs correlated significantly higher (z = 2.82, P \u3c 0.05) in patients with cortical dysplasia (n = 41, r = 0.61, P \u3c 0.01) compared with the group without lesions (n = 90, r = 0.16, P \u3e 0.05), with patients with hippocampal sclerosis falling between these two groups. Both memory (P \u3c 0.01) and language (P \u3c 0.01) LIs were higher in right- compared with left-sided lesions. Conclusion Correlation of language and memory is more pronounced in patients with structural lesions as compared with patients without lesions on MRI
Screening of COPD patients for abdominal aortic aneurysm
Purpose: Screening for abdominal aortic aneurysm (AAA) in “men aged over 65
years who have ever smoked” is a recommended policy. To reduce the number of
screenings, it may be of value to define subgroups with a higher prevalence of
AAA. Since chronic obstructive pulmonary disease (COPD) and AAA are associated
with several common risk factors, this study investigates the prevalence of
AAA in COPD patients. Patients and methods: Patients with COPD were identified
via the hospital information system. Inclusion criteria were: COPD stage I–IV,
ability to give full consent, and age >18 years; exclusion criteria were:
patient too obese for an ultrasound check, previously diagnosed AAA, prior
surgery for AAA, or ethical grounds such as concomitant advanced malignant or
end-stage disease. The primary endpoint of the study was an aortic diameter
measured by ultrasound of ≥30 mm. Defined secondary endpoints were evaluated
on the basis of medical records and interviews. Results: Of the 1,180
identified COPD patients, 589 were included in this prospective study. In 22
patients (3.70%), the aortic diameter was ≥30 mm, representing an AAA
prevalence of 6.72% among males aged >65 years. The risk of AAA increased with
the following comorbidities/risk factors: male sex (odds ratio [OR] 2.98),
coronary heart disease (OR 2.81), peripheral arterial occlusive disease (OR
2.47), hyperlipoproteinemia (OR 2.77), AAA in the family history (OR 3.95),
and COPD stage I/II versus IV (OR 1.81). Conclusion: The overall AAA
prevalence of 3.7% in our group of COPD patients is similar to that of the
general population aged >65 years. However, the frequency of AAA in male COPD
patients aged >65 years is considerably higher (6.72%) and increased further
still in those individuals with additional comorbidities/risk factors.
Defining subgroups with a higher risk of AAA may increase the efficiency of
screening
Permissive expansion and homing of adoptively transferred T cells in tumor-bearing hosts
Activated T cells expressing endogenous or transduced TCRs are two cell types currently used in clinical adoptive T-cell therapy. The ability of these cells to recognize their antigen, expand, and traffic to the tumor site are the initial steps necessary for successful therapy. In this study, we used in vivo bioluminescent imaging (BLI) of Renilla luciferase (RLuc) expressing T cells to evaluate the ability of adoptively transferred T cells to survive, expand and home to tumor site in vivo. Using this method, termed RT-Rack (Rluc T cell tracking), we followed T-cell response against tumors in vivo. Expansion and homing of adoptively transferred T cells were antigen dependent, but independent of the host immune status. Moreover, we successfully detected T-cell response to small and large tumors, including autochthonous liver tumors. The adoptively transferred T cells were not ignorant or excluded in a partially tolerant host, which expressed low level of the target in the periphery. Using T cell receptor-engineered T cells, we showed the ability of these cells to respond in tumor-bearing hosts by expanding and homing to the tumor site. In all these models, the host immune status, the nature of the tumor or of the antigen, the tumor size, and the presence of the targeted antigen in the periphery did not prevent the adoptively transferred T cells from responding by expanding and homing to the tumor. However, T cells had higher expression of the inhibitory receptor PD1 and reduced functional activity when a self-antigen was targeted
Visual Naming Performance after ATL Resection: Impact of Atypical Language Dominance.
Purpose- To characterize the interaction between language dominance and lateralization of the epileptic focus for pre- and postoperative Boston Naming Test (BNT) performance in patients undergoing anterior temporal lobectomy (ATL).
Methods- Analysis of pre- and postoperative BNT scores depending on lateralization of language as measured by the intracarotid amobarbital procedure (IAP) versus lateralization of the temporal lobe epileptic focus.
Results- Changes between pre- and postoperative BNT performance depended on epilepsy lateralization (effect size = 0.189) with significant decrease in patients undergoing left ATL. Subgroup analysis in these showed that postoperative decline in BNT scores was significant in patients with atypical (n = 14; p \u3c 0.05), but did not reach statistical significance in patients with left language dominance (n = 36; p = 0.09). Chi-square test revealed a trend of higher proportions of patients experiencing significant postsurgical deterioration in naming performance in atypical (57.1%) as compared to left language dominance (30.6%; p = 0.082). Surgical failure was also associated with greater decline of BNT scores and was more common in atypical than in left language dominant patients (χ2 (1, n = 98) = 4.62, p = 0.032). Age of onset, duration of epilepsy, and seizure frequency had no impact on changes in BNT performance.
Conclusion- Atypical language dominance is a predictor of change in visual naming performance after left ATL and may also impact postsurgical seizure control. This should be considered when counseling surgical candidates
Mucosal Inducible NO Synthase–Producing IgA+ Plasma Cells in Helicobacter pylori–Infected Patients
Tumor stroma-derived TGF-beta limits Myc-driven lymphomagenesis via Suv39h1-dependent senescence
Activated RAS/BRAF oncogenes induce cellular senescence as a tumor-suppressive barrier in early cancer development, at least in part, via an oncogene-evoked DNA damage response (DDR). In contrast, Myc activation-although producing a DDR as well-is known to primarily elicit an apoptotic countermeasure. Using the Emu-myc transgenic mouse lymphoma model, we show here in vivo that apoptotic lymphoma cells activate macrophages to secrete transforming growth factor beta (TGF-beta) as a critical non-cell-autonomous inducer of cellular senescence. Accordingly, neutralization of TGF-beta action, like genetic inactivation of the senescence-related histone methyltransferase Suv39h1, significantly accelerates Myc-driven tumor development via cancellation of cellular senescence. These findings, recapitulated in human aggressive B cell lymphomas, demonstrate that tumor-prompted stroma-derived signals may limit tumorigenesis by feedback senescence induction
Seizure Detection, Seizure Prediction, and Closed-Loop Warning Systems in Epilepsy
Nearly one-third of patients with epilepsy continue to have seizures despite optimal medication management. Systems employed to detect seizures may have the potential to improve outcomes in these patients by allowing more tailored therapies and might, additionally, have a role in accident and SUDEP prevention. Automated seizure detection and prediction require algorithms which employ feature computation and subsequent classification. Over the last few decades, methods have been developed to detect seizures utilizing scalp and intracranial EEG, electrocardiography, accelerometry and motion sensors, electrodermal activity, and audio/video captures. To date, it is unclear which combination of detection technologies yields the best results, and approaches may ultimately need to be individualized. This review presents an overview of seizure detection and related prediction methods and discusses their potential uses in closed-loop warning systems in epilepsy
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