Extraction and localization of mesoscopic motor control signals for human ECoG neuroprosthetics

Electrocorticogram (ECoG) recordings for neuroprosthetics provide a mesoscopic level of abstraction of brain function between microwire single neuron recordings and the electroencephalogram (EEG). Single-trial ECoG neural interfaces require appropriate feature extraction and signal processing methods to identify and model in real-time signatures of motor events in spontaneous brain activity. Here, we develop the clinical experimental paradigm and analysis tools to record broadband (1Hz to 6kHz) ECoG from patients participating in a reaching and pointing task. Motivated by the significant role of amplitude modulated rate coding in extracellular spike based brain-machine interfaces (BMIs), we develop methods to quantify spatio-temporal intermittent increased ECoG voltages to determine if they provide viable control inputs for ECoG neural interfaces. This study seeks to explore preprocessing modalities that emphasize amplitude modulation across frequencies and channels in the ECoG above the level of noisy background fluctuations in order to derive the commands for complex, continuous control tasks. Preliminary experiments show that it is possible to derive online predictive models and spatially localize the generation of commands in the cortex for motor tasks using amplitude modulated ECoG.     

Can core biopsy be used instead of surgical biopsy in the diagnosis and prognostic factor analysis of breast carcinoma?

PURPOSE: The aim of this article was to investigate the efficacy of ultrasonography-guided core needle biopsy and prognostic factor analysis of breast cancer to plan overall treatment strategy. PATIENTS AND METHODS: A consecutive series of nonpalpable and palpable breast cancers constituted our study group (n= 201 lesions; mean size, 20.4 mm) Mean number of core samples was 3.4. Malignant lesions diagnosed with core biopsy underwent therapeutic surgical excision. Core biopsy and surgical excisions were compared for histologic type, grade, estrogen receptors (ERs), progesterone receptors (PgRs), and c-erbB2 levels. Cutoff values for ER, PgR, and c-erbB2 affecting the management strategy were selected as 10%, 10%, and 50%, respectively. RESULTS: Eighty-five lesions (42.3%) were malignant in core biopsy (mean size, 18.4 mm). Among these, 11 were inoperable and 13 were surgically excised at other institutions. In 61 lesions, core and surgical excision specimens were evaluated in the same institution (mean tumor size, 18.6 mm; range 6-60 mm). Concordance between the 2 biopsy methods was 85.2% (52 of 61) for histologic type of tumor, 68.8% (33 of 48) for tumor grade, 90% (27 of 30) for ER, 86.7% (26 of 30) for PgR, and 79.3% (23 of 29) for c-erbB2 levels. Appropriate site selection for sampling was indicated to be of paramount importance, especially in determining reliable ER, PgR, and c-erbB2 levels. CONCLUSION: Core needle biopsy of breast cancer is equally effective compared with surgical biopsy and can be used in overall treatment planning. However, appropriate site selection for sampling should be guaranteed using ultrasonographic guidance.     

Clinical anatomy of hepatic vessels by computed tomography angiography: A minireview

The liver has a complex vascular anatomy with a unique dual blood supply. Clinical conditions of the liver vary widely and include disorders originating in the vascular and biliary systems as well as the parenchyma. In most vascular disorders, the effects on the liver are generally subclinical because of its abundant blood supply. However, early diagnosis of such vascular diseases can significantly reduce patient morbidity and mortality. Because imaging findings of vascular disease are not always readily apparent, diagnosis can be difficult. Computed tomography angiography is an excellent imaging modality for visualizing the vascular anatomy of patients for treatment planning. In this review article, we focus on the vascular anatomy of the liver and the imaging findings in some acute hepatic vascular diseases.     

Comparison between tensile characteristics of various suture materials with two suture techniques: an in vitro study

Clinical Oral Investigations - The first objective of the present study was to evaluate the tensile strength and elongation to failure of commonly used suture materials in oral surgery. As a...     

Expression of c-kit proto-oncogene product in breast tissue

The proto-oncogene c-kit encodes a transmembrane tyrosine kinase growth factor receptor. Stem cell factor, the receptor ligand, plays an important role in the development of certain neoplasms. c-kit is selectively and competitively bound by STI-571, a newly developed tyrosine kinase inhibitor. Several investigators report conflicting results concerning its expression, especially in malignant breast lesions. The objective of this study was to better characterize the expression of c-kit within the spectrum of breast epithelium (normal breast epithelium, nonneoplastic lesions, and breast carcinoma). Seventy-seven randomly selected breast tissue samples, each containing normal breast epithelium (21), invasive breast carcinoma (41), in situ breast carcinoma (29), papilloma (8), fibroadenoma (5), fibrocystic change (11), and/or metastatic breast carcinoma (4), were immunostained with polyclonal rabbit antihuman c-kit (Dako, Carpenteria, CA) at a dilution of 1:200. The staining was interpreted as negative if no cells were immunoreactive, weak positive if 5% of the cells were immunoreactive, and positive if more than 5% of the cells were immunoreactive. Appropriate positive and negative controls were used. The observed staining was cytoplasmic, with highlighting of the nuclear membrane. Normal breast epithelium was positive in all cases. More than half of the cases of hyperplastic changes and benign neoplasms (fibroadenoma and papilloma) were positive. Only 10% of invasive and in situ carcinomas showed positivity for c-kit. c-kit is consistently expressed in normal breast epithelium, variably expressed in benign breast lesions, and poorly expressed in breast carcinoma. These data suggest that c-kit may play a role in breast tumor progression and may therefore have diagnostic, prognostic, and therapeutic implications.