ABSTRACT
Objective To observe MSCT features of partially or completely low enhancement of pancreas neuroendocrine tumors (PNENs).Methods The clinical data and MSCT features before pancreatectomy in 44 patients with confirmed PNENs were retrospectively reviewed.The MSCT findings were evaluated including tumor size, location, margin, density, intratumoral structure, bile duct and pancreatic ductal dilation and distant metastasis.Tumors were classified into complete enhancement type, partially or completely low enhancement type for further comparative analysis based on MSCT enhancement during pancreatic stage.Results A total of 56 PNENs in 44 patients were found, and there were 31 partially or completely low enhanced PNENs and 25 completely enhanced PNENs.The former were larger than the latter [mean tumor size, (3.3±2.2)cm vs (1.4±0.9) cm], and irregular shape and cystic components within tumors were more often observed (all P<0.05).There were no significant differences between the two types of PNENs in terms of gender, the presence of functional tumor, tumor location, clear tumor margin, intratumoral calcification, bile and pancreatic duct dilation and metastasis.76.0%(19/25) of completely enhanced PNENs reached peak enhancement in arterial phase, and 71.0%(22/31) of low enhancement PNENs reached peak in pancreatic phase.Enhanced intratumoral blood vessels in the arterial phase were more frequent in low enhancement PNENs, and the difference was statistically significant (P<0.05).There were significant differences on pathological grade between the two types of PNENs (G1=21,G2=4,G3=0 vs G1=18,G2=5, G3=8), and the difference was statistically significant (P<0.05).Conclusions Compared with complete enhancement PNENs, partially or completely low enhancement PNENs had bigger size, irregular shape, and cystic component.Intratumoral blood vessels in the arterial phase were observed, peak enhancement arrived later and the pathological grade was higher.
ABSTRACT
Objective To evaluate 3D CT features of normal anatomy,anatomic variations and fractures of occipital squama.Methods The 3D CT features on MIP,VR images were analyzed retrospectively in 589 pediatric cases.The normal anatomy,anatomic variations and fractures of occipital squama were observed respectively,and the differential diagnostic features including the individual location,appearance and extension were analyzed.Results Four hundred and thirty-three patients (75.2％) showed normal anatomy,including 154 patients with adult occipital anatomical features,279 patients with posterior intraoccipital synchondrosis,and 37 patients with Kerckring-supraoccipital synchondrosis.When cases with recent trauma history were excluded,113 patients (19.1％) showed anatomic variants,including unpenetrating sutures and penetrating sutures.The former could be subdivided to Mendosal sutures in 23 cases,superior median fissures in 19 cases,and midline supraoccipital fissures in 4 cases,while the latter could be subdivided to the interparietal bone variations in 54 cases,wormian bones in 23 cases,and accessory bones in 7 cases.Two or more variations coexisted in 33 cases.The occipital squama fractures were shown in 34 cases (5.6％),including linear fractures in 27 cases,comminuted fractures in 3 cases,with depression fracture in one case,separation of cranial sutures in 3 cases,and other fractures associated with variants in 3 cases.The fractures were sharp,or jagged,without limitation of the occification.Conclusion There are different 3D CT features of normal anatomy,anatomic variations and fractures of occipital squama in children,which are important for making the accurate diagnosis.
ABSTRACT
<p><b>OBJECTIVE</b>To establish a brain functional network of the whole brain based on glucose metabolism, and to evaluate the cost and efficiency of the functional network.</p><p><b>METHODS</b>18F-FDG PET of 148 healthy volunteers (30-59 years, n = 148) was performed in a resting state. Images were registered to atlas by using the statistical parametric mapping (SPM) software. The functional connectivity between 90 cortical and sub-cortical regions was estimated by correlation analysis.</p><p><b>RESULTS</b>Glucose metabolism brain functional networks had global efficiency greater than the lattice but less than the random graph, and local efficiency greater than random but less than lattice. This characteristically small-world behavior of the brain network was most consistently seen for low-cost to medium-cost networks. The small world regime was Cost-[0.0512, 0.5406]. The cost efficiency of the networks typically had a maximum positive value when the cost was 0.23.</p><p><b>CONCLUSIONS</b>Glucose metabolism brain functional networks have economical small-world properties. It is feasible to analyze the functional characteristics of human brain by study 18F-FDG PET images. This paper provides a new method for studies on brain function.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Brain , Metabolism , Physiology , Brain Mapping , Fluorodeoxyglucose F18 , Glucose , Metabolism , Models, Neurological , Nerve Net , Positron-Emission Tomography , MethodsABSTRACT
The discovery of the nerve growth factor(NGF),a specific protein material,by Rita Levi-Montalcini and her colleagues(1954)led to the observation that ifNGF is added to the culture medium,sympathetic and sensory neurons grow well inculture,for it is a potent and specific maintenance factor for these two types of neu-rons.Therefore,we chose the superior cervical ganglion(SCG)as a model systemfor nerve tissue culture in order to study the development,differentiation and rege-neration of nervous tissue in vitro.This report presents what we have observed onthe cultures of SCG that have been successfully established in our laboratory bymeans of explant technique.SCG from newborn rats were explanted onto collagen or plasma-coated coverslipsand maintained in Maximow depression slide assemblies at 37℃.The fluid me-dium was replaced twice a week and consisted of 1/3 calf serum,1/3 synthetic medium199 and 1/3 Hanks' BSS,or of equal parts of calf serum and Hanks' BSS,supplementedwith 600 mg% glucose.NGF(a crude extract of mouse salivary gland)was added tothe medium in a proportion of 1:20;for control,no NGF was added to the medium in some cultures.The cultures were examined microscopically every day,Nissl's stai-ned,Bodian's protargol and ammonium silver impregnated preparations were madeperiodically.Time lapse microcinematographic records were also made.We have planted altogether 209 SCG from newborn rats.All of them grew suc-cessfully in culture with NGF or without NGF,but the SCG with NGF grew muchmore rapidly than those without NGF.NGF strongly stimulates the outgrowth ofneurites and maintains the survival of the sympathetic neurons.Neurites grew outindividually or,more frequently,as bundles extending radially toward the peripheryor forming a meshwork.The tips of elongating neurites expanded to form growthcones from which are projected long slender microspikes(filopodia).These microspi-kes continually waved about,extending,and retracting as the growth cone movedover a substratum.The behavior of the growing tip of neurite is best analyzed bytime lapse microcinematography.The Schwann cells emerged from the explant andproliferate to accompany the neurites.These cells,fusiform or filiform in shape,were usually arranged in alignment along the neurites.They could be easily distingui-shed from fihroblasts.Mitosis of Schwann cells had been observed and recorded bytime lapse microcinematography.The bodies of the sympathetic neurons did not mig-rate away from the explant.
ABSTRACT
On one hand this paper used co-culture method of rat normal or injuried sciatic nerves with newborn rat superior cervical ganglia (SCG) to observe that the neurite outgrowth of SCG induced by the nerve, on the other hand we made normal or injuried sciatic nerve extracts in order to observe their neurite-promoting effects on PC12 cells to various dilutions of nerve extracts. The results show that normal and injuried sciatic nerves contain neurite-promoting factors (NPFs) for SCG sympathetic neurons. However, the NPF activity of injuried nerve is higher than that of normal nerve and has no significant differences from 1-41 days postlesion. We have also observed the neurite-promoting effects of normal or injuried sciatic nerve extracts on PC12 cells. There is a maximal effect with the injuried nerve extract prepared at 4 days post-lesion. The neurite-promoting activity of injuried (12 hours to 42 days post-lesion) nerve extracts remain constant. The rate of neurite elongation in PC12 cells relate to the dilution of nerve extracts. Experimental analysis suggests that the nerve NPFs may be not the single but two or more factors which may be produced and released by Schwann cells.
ABSTRACT
Nerve growth factor (NGF) can promote the outgrowth of neurites of the target ganglia. In order to further explore the relationship between this effect and the synthesis of RNA and DNA in the neurons, an autoradiography of 3~H-uridine and 3~H-thymidine was used. Superior cervical ganglia (SCG) from newborn rats were cultivated by Maximow's double coverslip method. All cultures were divided to one group of cultures a crude preparation of NGF was added to the medium and another group without NGF served as control. Before tissue culture was stopped, the. covership cultures were transferred to thelabeling-medium and incubated, and then they were fixed, and cut into serial sections and subjected to autoradiographie processes. The results show that the percentage and the level of grains of neurons labeled by 3~H-uridine in the NGF group are higher than that of control. Moreover, before the growth rate of neurites reaches a peak, the level of grains of neurons labeled by 3~H-uridine in the NGF group is obviously increased. The evidence suggests that NGF can promote the synthesis of RNA in neurons of SCG, which has a direct bearing on the quick outgrowth of neurites. In the experiments with 3~H-thymidine incorporation, that the NGF may promote the synthesis of DNA in some neurons of the third day SCG in vitro was also observed.
ABSTRACT
The superior cervical ganglia (SCG) were dissected from neonatal rats.Dissoci-ated cell cultures were grown in Eagle's MEM supplemented with 20% calf serumwhich contain nerve growth factor (NGF).The cultures were divided into two groups:laser irradiation group and control.The former was exposed to lower dose of Helium-Neon laser (power:4 milliwatt)5 minutes every two hours.Two groups cultured for 20,22,24 and 28 hoursrespectively.Then the length of neurites of neurons were measured.At 22 hours,RNA and DNA synthesis of neurons labeled by ~3H-uridine and ~3H-thymidine wereobserved.The results showed that lower dose of Helium-Neon laser irradiation not onlypromotes growth of neurite but also enhances RNA synthesis of neurons in culture.However DNA synthesis in neurons does not promote in this experiment.
ABSTRACT
Optic nerves were dissected from 7-day-old Sprague-Dawley rats, dissociated with collagenase and trypsin, and cultured on poly-L-lysine coated glass coverslips. Cultures were grown in the B-S medium (Bottenstein and Sato, 1979) containing 0.5% fetal calf serum(FCS). All of the coverslip cultures were divided into 4 groups: i. e. Ⅰ, "Ⅰ+GMF", Ⅱ, and "Ⅱ+GMF". Optic nerve glial cells were cocultured with glioblast monolayers in both group Ⅱ and group "Ⅱ+GMF". Glia maturation factor (GMF) was added to the medium in a concentration of 250 ng/ml for group "Ⅰ+GMF" and group "Ⅱ+GMF". No GMF was added to the medium in both group Ⅰ and group Ⅱ. The coverslip cultures were treated with indirect immunofluorescence to identify the cell types of optic nerve. Cells were double-labled with monoclonal gotibody A2B5 and anti-galactocerebroside(GC) monoclonal antibody, or A2B5 and anti-glisl fibrillary acidicprotein (GFAP) antibody. The bipotential glial progenitor cells (A2B5~+, GC~-; or A2B5~+, GFAP~-), mature oligodendrocytes (A2B5~-, GC~+), immature oligodendrocytes(A2B5~+, GC~+), type 1 astrocytes (A2BS~-, GFAP~+) and type 2 astrocytes (A2B5~+, CFAP~+) can be distinguished.After 5 days in culture, the number of cells in group "Ⅱ+GMF" showed a significant increase (P
ABSTRACT
Bilateral ablation of the cerebral parietal cortex in adult rats was performed. After appropriate days, the tissue surrounding the wound was removed and the brain wound tissue extract (EWTE) was prepared. Newborn rat cerebral cortical neurons were used as a culture model to test the neuronotrophic factors (NTFs) and neuritepromoting factors (NPFs) in EWTE. In order to investigate the origin of above mentioned factors whether related to the macrophages which appeared in the brain wound region at early stage, we designed to culture macrophages and collected the macrophage conditioned medium (M?CM) to measure their NTF and NPF activities for cultured cerebral cortical neurons. On the other hand, we also observed the effect of EWTE and M?CM on PC 12 (phehrmytema) cells and further studied the action of NPFs. Cur experimental results show that EWTE and M?CM contained NTFs and NPFs for cultured cerebral cortical neurons. These factors appeared in EWTE at 4 days post-lesion, with maximal level of their activities reached between 5 and 6 days post-lesion and there was another peak of NPF activity at 9 days post-lesion, until 13 days post-lesion also detected their activities. The NTF activity in M?CM was lower than that in BWTE, in contrast, the NPF activity in M?CM was higher than that in BWTE. There was NPF activity to PC 12 cells in BWTE and M?CM. According to the experimental assays, we suppose that the neurotrophic factors in BWTE mainly come from the macrophages which appear in the lesion site at early stage of injured brain, subsequently, it may relate to the astrocytes. The components of these factors may be complexity and multiplicity that remain to be solved.
ABSTRACT
Glia maturation factor(GMF)detected in the adult brain is an acidic proteinthat has the ability to promote the morphological and chemical differentiation ofastroblasts,but this effect is reversible.In the present study we have establishedneuron-enriched dissociated primary cultures from 7-day-old rat cerebellar cortexin which about 97% of the cells are neurons especially granule cells using differential count of indirect immunofluorescence.The addition of purified GMF to the culturesmarkedly enhances neuronal survival,while control cultures grown in the absence ofGMF exhibit a significant decrease in neuronal number.These GMF effects aredose-dependent,with optimal stimulation occurring at a concentration of 250 ng/ml.Although the mechanism by which purified GMF influences cerebellar corticalneuronal survival is not known,these results suggest that GMF not only affectsglial cells,but also may function as a neurotrophic agent in the central nervousmetsys