脑肿瘤及脑肿瘤图像分类的研究进展

脑肿瘤分类的方法很多,目前尚无统一的分类方法,并且各种肿瘤的组织发生与病理特征不同,其良性与恶性以及物学特性也不一样。通常按组织学可分类如下:(1)发源于神经胶质的肿瘤:星形细胞瘤、少支胶质细胞瘤、髓母细胞瘤等。(2)发源于脑膜的肿瘤:脑膜瘤、脑膜肉瘤、蛛网膜囊肿等。(3)发源于垂体的肿瘤:厌色细胞腺瘤,嗜酸、嗜碱性细胞腺瘤。(4)发源于颅神经的肿瘤:听神经瘤、三叉神经瘤等各种神经鞘瘤。(5)发源于胚胎残余组织:颅咽管瘤、脊索瘤、皮样囊肿等。(6)发源于血管细胞:血管瘤及血管网织细胞瘤等。(7)由其它部位转移或侵入的肿瘤:各种转移瘤及鼻咽癌等。     

脑肿瘤及脑肿瘤图像分类的研究进展

脑肿瘤分类的方法很多,目前尚无统一的分类方法,并且各种肿瘤的组织发生与病理特征不同,其良性与恶性以及物学特性也不一样。通常按组织学可分类如下：（1）发源于神经胶质的肿瘤：星形细胞瘤、少支胶质细胞瘤、髓母细胞瘤等。（2）发源于脑膜的肿瘤：脑膜瘤、脑膜肉瘤、蛛网膜囊肿等。（3）发源于垂体的肿瘤：厌色细胞腺瘤,嗜酸、嗜碱性细胞腺瘤。（4）发源于颅神经的肿瘤：听神经瘤、三又神经瘤等各种神经鞘瘤。（5）发源于胚胎残余组织：颅咽管瘤、脊索瘤、皮样囊肿等。（6）发源于血管细胞：血管瘤及血管网织细胞瘤等。（7）由其它部位转移或侵入的肿瘤：各种转移瘤及鼻咽癌等。     

Delayed Phospholipid Degradation in Rat Brain After Traumatic Brain Injury

Abstract: Lipid second messengers such as arachidonic acid and its metabolites and diacylglycerols (DAGs) are affected in brain injury. Therefore, changes in the pool size and the fatty acid composition of free fatty acids (FFAs) and DAGs were analyzed in different rat brain areas 4 and 35 days after traumatic injury. Cortical impact injury of low-grade severity was applied in the right frontal somatosensory cortex. Four days after injury, FFAs and DAGs were increased by three- and twofold, respectively, in the injured cortex and to a lesser extent in the contralateral cortex compared with sham-operated animals. Docosahexaenoic acid followed by stearic acid, and arachidonic acid, displayed the greatest changes in both FFAs and DAGs. By day 35, free stearic, oleic, and arachidonic acids remained elevated in the damaged cortex (1.5-fold each). DAGs showed the greatest change, reaching values 2.7-fold higher than sham in all frontal and occipital cortical areas, including brainstem. Oleoyl- and arachidonoyl-DAGs (four- and threefold increase, respectively) followed by docosahexaenoyl-DAGs (twofold) contributed to the DAG accumulation. These results reveal that traumatic brain injury triggers a sustained and time-dependent activation of phospholipase-mediated signaling pathways leading to membrane phospholipid degradation and targeting, early on, docosahexaenoyl phospholipid-enriched excitable membranes.     

d-Aspartate in Human Brain

The presence of the biologically uncommon D-aspartic acid (D-aspartate) in human brain white matter has been previously reported. The earlier study has now been expanded to include D/L-aspartate ratios from 67 normal brains. The data show that the D-aspartate content increases rapidly from 1 year to approximately 35 years of age, levels off in middle age, and then appears to decrease somewhat. The D-aspartate content in gray matter remains at a consistently low level (half of that found in white matter) throughout the human life span. Within the limitations of current analytical methods, there was no detectable difference in D/L-aspartate ratios in white and gray matter of brains with Alzheimer's disease and several other pathologies when compared with brains of normal subjects. However, the presence of a significant D-aspartate level in white matter during the adult life span may lead to changes in protein configuration related to dysfunctions associated with the aging brain.     

Parvalbumin in Human Brain

Parvalbumin was isolated from human cerebral cortex and biceps and triceps muscles by HPLC. The immunological properties of the human protein and the mobility in two-dimensional polyacrylamide gels were similar to that of parvalbumin isolated from the muscles of rat, mouse, rabbit, and chicken. The tryptic peptide maps of the human parvalbumin, however, differed considerably from all other parvalbumins, indicating a distinct primary structure. The immunolabeled cells in the hippocampus of the human brain were of different sizes and forms; they occurred in all subfields and probably represent interneurons.     

Brain Pericytes: Emerging Concepts and Functional Roles in Brain Homeostasis

Brain pericytes are an important constituent of neurovascular unit. They encircle endothelial cells and contribute to the maturation and stabilization of the capillaries in the brain. Recent studies have revealed that brain pericytes play pivotal roles in a variety of brain functions, such as regulation of capillary flow, angiogenesis, blood brain barrier, immune responses, and hemostasis. In addition, brain pericytes are pluripotent and can differentiate into different lineages similar to mesenchymal stem cells. The brain pericytes are revisited as a key player to maintain brain function and repair brain damage.     

Neurovesicles in Brain Development

Long before the nervous system is organized into electrically active neural circuits, connectivity emerges between cells of the developing brain through extracellular signals. Extracellular vesicles that shuttle RNA, proteins, and lipids from donor cells to recipient cells are candidates for mediating connectivity in the brain. Despite the abundance of extracellular vesicles during brain development, evidence for their physiological functions is only beginning to materialize. Here, we review evidence of the existence, content, and functions of extracellular vesicles in brain development.     

Advances in Brain Research

Current study of the brain has reached a stage where the researcher in this field realizes that he is only just beginning to unravel the secrets of the brain. It is becoming increasingly clear that even the most significant physiological principles of nervous activity discovered so far are merely the portals of a hitherto little-known world of molecular processes that play a decisive role in the working of the brain.