Newborn GnRH neurons in the adult forebrain of the ring dove

The preoptic area of the hypothalamus is a key area that produces gonadotrophin-releasing hormone (GnRH). In birds, the chicken GnRH-I-form neurons are responsible for the hypothalamus-pituitary-gonadal system, which controls reproduction. In the ring dove, electrolytic lesion in the adult hypothalamus induces neurogenesis. In this study, we determined whether adult neurogenesis is involved in repairing GnRH neurons, specifically by generating newborn cells exhibiting GnRH-I immunoreactive properties. We selectively applied electrolytic lesions to three different regions of the diencephalon, including the preoptic area, which contains GnRH-I neurons, and identified new cells (BrdU-positive cells) that co-labeled with GnRH-I-immunoreactive cells. The BrdU⁺/GnRH⁺ double labeled cells were then confirmed with confocal laser analysis. In brains of both male and female ring doves we found new neurons at the lesion site of the preoptic region that were GnRH-I immunoreactive. However, the total number of GnRH neurons in the lesioned brains was less than that of sham-lesioned brains. When two other regions of the diencephalon that contain GnRH-I neurons were damaged, no recruitment of new GnRH-I neurons was detected. The rate of neurogenesis depends on the bird's reproductive phase when the lesion was applied. We found BrdU⁺/GnRH⁺ double-labeled cells almost exclusively during the pre-laying phase when birds are engaged in active courtship that leads to egg laying. Our observations suggest that recruitment of GnRH immunoreactive new neurons is restricted to the hypothalamic region and is sensitive to the reproductive stage of the birds.     

Diffuse large cell lymphoma presenting as a sacral mass and lupus anticoagulant

A 67-year-old gentleman presented to Yale-New Haven Hospital (YNHH) for assessment of a supratherapeutic INR and sacral lesion. Hematologic workup revealed elevated ESR, PT, INR, PTT, and CRP, mixing studies that failed to correct, and a positive Russell Viper Venom Test (RVVT), which confirmed the presence of lupus anticoagulant (LA), a subtype of antiphospholipid syndrome (APA). Pathology of the patient's sacral lesion revealed diffuse large B-cell lymphoma. This case provides insight into the association between APA and lymphoid neoplasm. The patient's unique presentation is in marked contrast to other reports of APA and lymphoid malignancy, which are typically associated with elevated PTT, normal PT, minimal extranodal disease, and potential thrombotic complications. Further, treatment with Rituximab-CHOP chemotherapy led to excellent clinical response with tumor remission and normalization of PT and PTT.     

Cerebellum,temporal predictability and the updating of a mental model

We live in a dynamic and changing environment, which necessitates that we adapt to and efficiently respond to changes of stimulus form (‘what’) and stimulus occurrence (‘when’). Consequently, behaviour is optimal when we can anticipate both the ‘what’ and ‘when’ dimensions of a stimulus. For example, to perceive a temporally expected stimulus, a listener needs to establish a fairly precise internal representation of its external temporal structure, a function ascribed to classical sensorimotor areas such as the cerebellum. Here we investigated how patients with cerebellar lesions and healthy matched controls exploit temporal regularity during auditory deviance processing. We expected modulations of the N2b and P3b components of the event-related potential in response to deviant tones, and also a stronger P3b response when deviant tones are embedded in temporally regular compared to irregular tone sequences. We further tested to what degree structural damage to the cerebellar temporal processing system affects the N2b and P3b responses associated with voluntary attention to change detection and the predictive adaptation of a mental model of the environment, respectively. Results revealed that healthy controls and cerebellar patients display an increased N2b response to deviant tones independent of temporal context. However, while healthy controls showed the expected enhanced P3b response to deviant tones in temporally regular sequences, the P3b response in cerebellar patients was significantly smaller in these sequences. The current data provide evidence that structural damage to the cerebellum affects the predictive adaptation to the temporal structure of events and the updating of a mental model of the environment under voluntary attention.     

Stimulating the Lip Motor Cortex with Transcranial Magnetic Stimulation

Transcranial magnetic stimulation (TMS) has proven to be a useful tool in investigating the role of the articulatory motor cortex in speech perception. Researchers have used single-pulse and repetitive TMS to stimulate the lip representation in the motor cortex. The excitability of the lip motor representation can be investigated by applying single TMS pulses over this cortical area and recording TMS-induced motor evoked potentials (MEPs) via electrodes attached to the lip muscles (electromyography; EMG). Larger MEPs reflect increased cortical excitability. Studies have shown that excitability increases during listening to speech as well as during viewing speech-related movements. TMS can be used also to disrupt the lip motor representation. A 15-min train of low-frequency sub-threshold repetitive stimulation has been shown to suppress motor excitability for a further 15-20 min. This TMS-induced disruption of the motor lip representation impairs subsequent performance in demanding speech perception tasks and modulates auditory-cortex responses to speech sounds. These findings are consistent with the suggestion that the motor cortex contributes to speech perception. This article describes how to localize the lip representation in the motor cortex and how to define the appropriate stimulation intensity for carrying out both single-pulse and repetitive TMS experiments.     

马尔尼菲蓝状菌病致溶骨性损害合并Sweet样皮疹1例

本文报道广西医科大学第一附属医院皮肤性病科收治的马尔尼菲蓝状菌病致溶骨性损害合并Sweet样皮疹1例。免疫力正常人群较少患马尔尼菲蓝状菌病。本例患者既往体健,起初合并融骨性损害,在两性霉素B、伊曲康唑治疗过程中逐渐出现Sweet样皮疹。患者经两性霉素B、伊曲康唑、激素等治疗后,病情逐渐好转。     

Unilateral Pyramidotomy of the Corticospinal Tract in Rats for Assessment of Neuroplasticity-inducing Therapies

The corticospinal tract (CST) can be completely severed unilaterally in the medullary pyramids of the rodent brainstem. The CST is a motor tract that has great importance for distal muscle control in humans and, to a lesser extent, in rodents. A unilateral cut of one pyramid results in loss of CST innervation of the spinal cord mainly on the contralateral side of the spinal cord leading to transient motor disability in the forelimbs and sustained loss of dexterity. Ipsilateral projections of the corticospinal tract are minor. We have refined our surgical method to increase the chances of lesion completeness. We describe postsurgical care. Deficits on the Montoya staircase pellet reaching test and the horizontal ladder test shown here are detected up to 8 weeks postinjury. Deficits on the cylinder rearing test are only detected transiently. Therefore, the cylinder test may only be suitable for detection of short term recovery. We show how, electrophysiologically and anatomically, one may assess lesions and plastic changes. We also describe how to analyse fibers from the uninjured CST sprouting across the midline into the deprived areas. It is challenging to obtain >90% complete lesions consistently due to the proximity to the basilar artery in the medulla oblongata and survival rates can be low. Alternative surgical approaches and behavioural testing are described in this protocol. The pyramidotomy model is a good tool for assessing neuroplasticity-inducing treatments, which increase sprouting of intact fibers after injury.     

Reglα蛋白表达在胃癌及癌前病变组织中的变化

目的：观察再生基因1α（Regeneration gene 1α,Regla）在胃癌前病变组织及胃癌组织中的表达变化,探讨Reglot在胃粘膜癌变中发挥的作用,为临床诊治提供理论基础。方法：收集2011年1月-2012年12月在我院接受胃镜活检的患者胃粘膜组织,病理确诊为浅表性胃炎的为正常组,中度以上萎缩及肠化的为癌前病变组及胃腺癌即胃癌组。采用荧光定量PCR的方法检测三组胃粘膜组织中Regla的mRNA表达情况。结果：Reglet的mRNA表达在正常组、癌变组及胃癌组织中呈进行性升高;胃癌组中,低分化及印戒细胞癌和Ⅳ期胃癌患者的Reg1α表达升高最为明显;Regla在不同分化程度的胃癌组织间表达无显著差异;Regla在Ⅳ期胃癌中的表达显著高于I／II期;差异均具有统计学意义（P〈0．05）。结论：作为一种生长因子Regla可能参与了胃粘膜癌变的过程,并且Reglet的高表达可能与胃癌的预后相关。     

Detection of medullary thyroid microcarcinoma using ultrasound‐guided fine needle aspiration cytology

G. C. H. Yang, K. Fried and P. H. Levine Detection of medullary thyroid microcarcinoma using ultrasound‐guided fine needle aspiration cytology Objective: Compared with incidental papillary thyroid microcarcinoma (microPTC), incidental medullary thyroid microcarcinoma (microMTC) is clinically more significant. The objective of the present study was to summarize our experience in detecting microMTCs. Methods: From 1995 to 2011, there were 10 825 thyroid fine needle aspirates (FNAs) guided using high‐resolution ultrasound with on‐site preparation and evaluation by a cytopathologist. Of the 140 microcarcinomas detected, 132 were microPTCs and eight were microMTCs, which are the subject of the present study. Results: All eight cases were incidentalomas and none of the five women and three men, age 37–70 years, had a family history of MTC. One patient had two FNAs at an interval of 10 months, two had a single lymph node metastasis and one had a 0.1‐cm tumour nodule near the main tumour. Four of five plasmacytoid cell microMCTs had irregular borders; two round cell and one rectangular cell tumours had smooth borders. In contrast, 17 larger MTCs diagnosed in the same period included seven plasmacytoid, four giant cell and six spindle cell types. All five plasmacytoid microMTCs were correctly diagnosed on FNA, but the round cell and rectangular cell tumours were undercalled as follicular lesions. Sampling of colloid from adjacent follicles was noted in microMTCs. Two were diagnosed on histology following recommended surgery and one was diagnosed on recommended repeat FNA. Conclusions: US‐guided FNA of thyroid lesions is a powerful tool in the detection of microMTCs, provided that cytopathologists are alerted to the pitfalls described in the present study.