Distributed cell assemblies for general lexical and category‐specific semantic processing as revealed by fMRI cluster analysis

Here, we ask whether frontotemporal cortex is functionally dissociated into distributed lexical and category‐specific semantic networks. To this end, fMRI activation patterns elicited during the processing of words from different semantic categories were categorized using k‐means cluster algorithms. Results showed a distributed pattern of inferiorfrontal, superiortemporal, and fusiform activation shared by different word categories. This shared activation contrasted with patterns of category‐specific semantic activation in widely distributed neural systems. Clustering revealed congruent functional specificity of focal area activations in frontal and temporal cortex; thus suggesting a correspondence between functional partitionings of frontocentral mirror neuron systems and those of inferiortemporal lexical and semantic circuits. Action words related to the face, arms, and legs specifically activated the motor system in a somatotopic manner, whereas form‐related words activated prefrontal areas. Similar functional specificity was evident in temporal cortex, where a different semantic topography emerged for form‐ and action‐related words. Results were replicated in a separate data set, therefore recommending fMRI cluster analysis as a reliable method for scrutinizing the brain basis of lexical, semantic, and conceptual systems in humans. As focal modules do not explain the distributed character of functionally specific clusters and their distinct topographies are at variance with general distributed processing accounts, the functionally‐homogenous distributed clusters specific to semantic types are best explained by specifically‐distributed cortical circuits which, similar to Hebbian cell assemblies, represent functional units with specific roles in cognitive processing, especially in lexical and semantic access and memory. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.     

Selective naming (and comprehension) deficits in Alzheimer's disease?

The study addresses the issue of the selective preservation of verbs in Alzheimer's disease (AD). Twenty three AD patients and age-matched controls named pictures of objects and actions and took part in a word-picture verification task. The results for picture naming revealed that both patients and controls were faster and produced more target responses for objects than actions. In the comprehension task, accuracy levels were comparable for nouns and verbs, but response times were longer for verbs. Although patients were more error prone and had longer latencies in both tasks than controls, the only qualitative difference in performance between the groups was in response to trials with semantically related foils in the word-picture verification task. Patients were particularly error prone in this condition. We conclude that the results do not provide support for the notion that verbs are selectively preserved in AD. They also do not provide conclusive evidence for claims that depressed naming and comprehension is (always) due to loss of semantic knowledge or inadequate access to semantic knowledge. Finally, we discuss the findings in relation to comparable investigations in patients with semantic dementia.     

RHD等位基因37bp和RHC等位基因109bp插入序列检测

目的研究RHD等位基因37bp插入序列和RHC等位基因109bp插入序列是否存在多态性。方法应用PCR—SSP技术检测82例汉族RhD阳性样本,206例汉族和70例维族RhD阴性样本RHD等位基因37bp插入序列和RHC等位基因109bp插入序列。结果上述样本均检测不到RHD基因37bp插入序列,即无RHD山假基因。82例汉族RhD阳性样本中有76例样本有RhC抗原,其中3例（3．95％）检测不到109bp插入片段;206例RhD阴性汉族样本中有75例样本有RhC抗原,其中4例（5．33％）检测不到109bp插入片段;70例RhD阴性维族样本中,无RhCC表型,3例RhCc样本均检测到109bp插入片段;其余204例Rhcc表型样本均未检测到109bp插入序列。结论中国人RHC等位基因109bp插入序列存在多态性,尚不能肯定中国人是否不存在RHDψ假基因。     

RHD等位基因37bp和RHC等位基因109bp插入序列检测

目的研究RHD等位基因37bp插入序列和RHC等位基因109bp插入序列是否存在多态性。方法应用PCR—SSP技术检测82例汉族RhD阳性样本,206例汉族和70例维族RhD阴性样本RHD等位基因37bp插入序列和RHC等位基因109bp插入序列。结果上述样本均检测不到RHD基因37bp插入序列,即无RHDψ假基因。82例汉族RhD阳性样本中有76例样本有RhC抗原,其中3例（3．95％）检测不到109bp插入片段;206例RhD阴性汉族样本中有75例样本有RhC抗原,其中4例（5-33％）检测不到109bp插入片段;70例RhD阴性维族样本中,无RhCC表型,3例RhCc样本均检测到109bp插入片段;其余204例Rhcc表型样本均未检测到109bp插入序列。结论中国人RHC等位基因109bp插入序列存在多态性,尚不能肯定中国人是否不存存RHDψ假基因。     

In vitro cytotoxicities of ionic liquids: effect of cation rings, functional groups, and anions

In vitro cytotoxicities were measured for ionic liquids (ILs) containing various cations and anions using the MCF7 human breast cancer cell line. We measured the cytotoxicities of ionic liquids containing the cations pyridinium, pyrrolidinium, piperidinium, or imidazolium with various alkyl chain lengths, and the anions bromide, bis(trifluoromethanesulfone)imide (Tf(2)N), trifluoromethylsulfonate (TfO), or nonafluoromethylsulfonate (NfO). Three new hydrophobic, task-specific ionic liquids (TSILs), namely, [MBCNPip](+)[Tf(2)N](-), [MPS(2)Pip](+)[Tf(2)N](-), and [MPS(2)Pyrro](+)[Tf(2)N](-) designed for metal-ion extraction were also evaluated. IC(50) values of the ionic liquids toward the MCF7 cells ranged from 8 microM to 44 mM. The toxicity depended significantly on the nature of the cations and anions, especially when the cations contained a long side chain. TSILs studied in this work were less toxic than the classical ILs.     

血清PSA检测的方法学评价

目的对时间分辨荧光免疫法（TRFIA）测定血清总前列腺特异性抗原（tPSA）和游离前列腺特异性抗原（fPSA）的方法学予以评价,评价TRFIA法测定血清总前列腺特异性抗原（tPSA）和游离前列腺特异性抗原（fPSA）灵敏度、精密度、回收试验及与化学发光免疫法（CLEIA）的相关性。方法采用重复性试验、回收试验、比较试验方法。结果tPSA和fPSA检测下限分别为0．02μg／L和0．05μg／L,批内变异系数分别为2．38％、3．16％,回收率分别为101．2％和102．4％,与CLEIA法高度相关,r值分别为0．986和0．964。结论TRFIA测定tPSA和fPSA稳定性好、灵敏度和准确度高,是当前免疫最有发展前途的超微量检测技术。     

Do we know all there is to know about Familial Adenomatous Polyposis?

Familial Adenomatous Polyposis (FAP) and Attenuated FAP (AFAP) are caused by a germline mutation in the Adenomatous polyposis coli (APC) gene. Recently, a new pathway characterized by a biallelic mutation in the MYH gene, with a recessive model of inheritance was discovered for this inherited syndrome. This report describes a Tunisian patient with an attenuated FAP phenotype, presenting seven colon polyps and an adenocarcinoma but no detectable germline mutations in the FAP target genes. A well known somatic mutation was found in the APC mutation cluster region (MCR). This case shows that further studies are needed to fully understand all the pathways of the FAP syndrome.     

High levels of serum prostate-specific antigen due to PSA producing follicular non-Hodgkin's lymphoma

OBJECTIVE: Both carcinoma of the prostate and non-Hodgkin's lymphoma are common in elderly patients. Measurement of serum prostate-specific antigen (PSA) is a frequently used tool to diagnose and monitor prostate carcinoma and is generally specific for diseases of the prostate. CASE: We describe a 68-yr-old patient with voiding difficulties and high PSA levels, but without inflammatory or malignant changes upon multiple transrectal ultrasound guided prostate biopsies. Digital rectal examination was normal. Laboratory showed a strongly elevated PSA level (62 microg/L, Immulight 2000); DPC, USA). A CT-scan showed a retroperitoneal process with mass in the right pelvis and infiltration of the bladder wall, suggestive for metastatic prostate carcinoma. Surgical excision of an axillary lymph node set the diagnosis at a stage IV follicular lymphoma, Berard grade I to II in which the majority of neoplastic cells expressed PSA. After lymphoma-specific treatment, there was a positron emission tomography (PET) confirmed complete remission with normal PSA levels (6 microg/L), which still persists. CONCLUSION: Although rare, high PSA levels can be due to the presence of non-Hodgkin's lymphoma. Such a diagnosis should be considered when patients present with lymphadenopathy other than regional prostatic lymphadenopathy.     

腹泻患者粉螨感染调查

目的探讨粉螨致腹泻的发生特点。方法对腹泻患者进行粪螨分离、皮肤挑刺试验、血清总IgE、螨特异性IgE检测。其中粪螨分离采用饱和盐水漂浮法,抗体检测使用ELISA法。结果共检查241例腹泻患者,粪螨阳性率为17.01%(41/241),男、女粪螨阳性率分别为15.86%(23/145)和18.75%(18/96),差异无显著性(χ2=0.34,P>0.05);皮肤挑刺试验"、"、"+"、"±"和"?"者分别占9.13%(22/241)、7.47%(18/241)、5.81%(14/241)、4.98%(12/241)和72.61%(175/241)。粪螨阳性和阴性腹泻患者血清总IgE、螨特异性IgE分别为(165.72±78.55)IU/ml、(132.44±26.80)IU/ml和(145.22±82.47)IU/ml、(67.35±45.28)IU/ml,差异均具显著性(P<0.01)。从事中药材、粮食储藏和加工者粪螨阳性率为26.74%(23/86),其他职业人群粪螨阳性率为11.61%(18/155),差异具显著性(χ2=8.97,P<0.01)。结论粉螨寄生人体肠道可导致粉螨性腹泻,并使患者血清总IgE、螨特异性IgE升高,粉螨浸液皮肤挑刺试验阳性。腹泻患者粉螨感染的发生与所从事的职业有一定关系,但与性别无关。