BACKGROUND:Currently, there is no effective treatment for keloids that often recur. Its pathogenesis is stil entirely unclear, and fibroblast proliferation and apoptosis have become a research hotspot.
OBJECTIVE:To investigate the expression of Livin, Smac and Caspase-3 in keloids and to analyze their relationship so as to preliminarily explore the significance of Livin, Smac and Caspase-3 in the pathogenesis of keloids.
METHODS:RT-PCR and immunohistochemical methods were used to detect the mRNA and protein expressions of Livin, Smac and Caspase-3 in keloids (n=20) and normal skin tissues (n=20).
RESULTS AND CONCLUSION:Compared with the normal skin tissue, the mRNA and protein positive expressions of Livin were significantly higher in keloids (P < 0.05), while the mRNA and protein positive expressions of Smac and Caspase-3 were lower in keloids (P < 0.05). There was a negative association between Livin and Smac, Caspase-3 protein expression in keloids. These findings indicate that the high mRNA expression of Livin may cause the imbalance between proliferation and apoptosis of fibroblasts by inhibiting the mRNA expression of Smac and Caspase-3, and eventualy lead to the formation of keloid.

Objective To study the changes of the putamen metabolites with magnetic resonance spectrum(MRS),and to explore possible underlying unrecongnised aetiological factor and pathophysiology mechanism in the central nervous system of the patients with Tourette' s syndrome.Methods Twenty-two cases of Tourette' s syndrome,and twenty-two gender and age-matched subjects ( the control subjects ) were performed on a clinical 3.0 T MRI system.Proton prob-voxel spectroscopy imaging (1H-MRS) was obtained from two sides of the putamen.The metabolites included N-acetylaspartate (NAA),creatine and phosphocreatine ( Cr),choline-containing compounds (Cho),and myoinositol ( MI ).The value of the NAA,Cr,Cho,and MI were calculated by integration of their peaks.The ratios of NAA/Cr,Cho/Cr,ML/Cr were calculated respectively.Repeated measures analysis of variance ( ANOVA ) was used to test both the value of NAA/Cr,Cho/Cr,MI/Cr of the putamen for group difference,with group as between-subjects factor and side as within-subjects factor.Results The NAA/Cr ratio in patients ( left:1.29 ± 0.13 ; right:1.34 + 0.15 ) was significantly lower than that in the control subjects ( left:1.50 ± 0.08,T =1.962,P ＜0.05 ; right:1.52 ± 0.11,T =1.865,P ＜ 0.05 ).There was no significant difference in the Cho/Cr and MI/Cr ratio between both groups.Conclusion The abnormalities of the structure and(or) function in the putamens of patients may be the one of the underlying anaetiological factors and pathophysiology mechanisms of the Tourette' s syndrome.

ObjectiveTo investigate the central nervous system mechanisms of active of movement switch in the patients with Tourette' s syndrome( TS),and to explore the possible underlying distinct neural networks for tic trigger and generation. Methods Participants were 14 patients with TS and 14 age- and gender-matched healthy volunteers with no history of physical,psychiatric or neurological disease: All patients were assessed with functional magnetic resonances imaging (fMRI)of the brain during the intermittent performance of finger-tapping switch tasks,Blood-oxygen-level dependent-fMRI was performed using a 3.0 Tesla MR.The area over which the activation was distributed was calculated,and the activation volumes were also compared between the patients with TS and the control subjects.ResultsThe regions activated in the patients with TS and in the volunteers were similar in several brain regions,including contralateral precentral and postcentral gyrus,contralateral mesia pre-front gyrus,contralateral cingulate gyrus,contralateral insula and ipsilataral cerebellum. There were also many different activation areas between the patients and the control subjects. The patients with TS demonstrated more significant and extended activation in the contralateral pre- and postcentral gyrus than the healthy volunteers.The volume of the left pre- and postcentral gyrus of the TS patients was (8.024 ±0.071 ) cm3,while the volume of the left pre-and postcentral gyrus of the control subjects was ( 6.480 ± 0.026) cm3 ( t =3.026,P ＜ 0.01 ) ; The volume of the right pre- and postcentral gyrus was (6.192 ± 0.019) cm3 in the TS cases,while there was (5.608 ±0.037) cm3 in the control subjects (t =2.752,P ＜0.05).There were significant differences in the volumes of bilateral pre- and postcetral gyrus between the TS and control subjects. The activations of conralateral thalamus without contralateral insula were found in the patients with TS. Conversely, the contralateral insula activation without thalamus activation could be found in the healthy volunteers.ConclusionThe thalamus might play an important role in the aetiological and physiopathologic mechanisms of the TS. The thalamus along with the parietal cortex,cingulate cortex and insular cortex appear to constitute a distinct neural network for tic trigger and generation.

Objective To evaluate the effect of quick injection combining with slow infusion of Gd-DTPA on T1 relaxation of the blood. Methods Fifteen volunteers were recruited for coronary MRA study using a navigator-gated 3D-FIESTA sequence. Coronary MRA were acquired on the same segments two times at 5 minutes and 15 minutes after Gd-DTPA administration. Contrast agent was injected biphasically with 10 ml at a flow rate of 1.5 ml/s and 20 ml at 0. 05 ml/s to prolong the T1 relaxation effect. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated pre- and post-contrast MRA. Image quality was compared using t-test. Results The SNR and CNR at 5 minutes after contrast injection (35.37 ±6. 84 and 21.57 ± 6. 08 ) were significantly higher than that of pre-contrast MRA ( 27.38 ± 6. 24 and 13.19 ±6. 50). The SNR at 15 minutes after contrast injection (33. 81 ±9. 43) was higher than that of precontrast MRA, but there was no statistically difference(t = 1. 885 ,P =0. 074). The CNR at 15 minutes after contrast injection (21.20 ± 7.65) was significantly higher than that of pre-contrast MRA. The SNR and CNR at 15 minutes after contrast injection were no significant different compared with those at 5 minutes after contrast injection. Conclusion T1-shorting effect in the blood can be prolonged by quick injection combining with slow infusion of Gd-DTPA ,which meet with the need of multiple scans of coronary MRA.

Objective To get a MR imaging protocol for coronary arterial wall in vitro. Methods MR examinations were performed in 10 fresh porcine hearts. Three dimensional fast imaging employing steady state acquisition (3D FIESTA) was used to delineate left anterior descending artery (LAD), while 2D spin-echo T1W was performed with 8-channel head surface coil, temporomandibular surface coil and knee coil with the same parameters. T1WI was obtained with 384×256 and 512×512 in matrix using temporomandibular surface coil, and then T1WI, PDW and T2WI with fat saturation were obtained with different NEX using temporomandibular surface coil after injecting Resovist in LAD. Signal of the LAD wall, lumen, fat tissue adjacent to LAD, myocardium of anterior part of interventricular septum and noise were respectively measured. Signal-to-noise ratio (SNR) of image, contrast to noise ratio (CNR) between the wall and lumen (CNR1), CNR between the wall and surrounding fatty tissue (CNR2) were calculated. Results The SNR and CNR1, CNR2 of SE T1WI with temporomandibular coil were higher than those with 8-channel head surface coil and knee coil. SNR and CNR1, CNR2 of SE T1WI with 384×256 matrix were higher than those with 512×512 matrix. SNR and CNR1, CNR2 using 3 NEX were the highest. Conclusion Good SNR and CNR of porcine coronary wall can be achieved using temporomandibular surface coil, 384×256 in matrix and NEX of 3.

INTRODUCTIONMotor neuron damage and cortical spinal tract (CST) degeneration in amyotrophic lateral sclerosis (ALS) are difficult to visualise and quantify on conventional magnetic resonance imaging (MRI).

CLINICAL PICTUREWe studied 8 ALS patients and 12 normal volunteers using diffusion tensor imaging (DTI) and fibre tractography using fibre assignment by continuous tracking (FACT) to study the fibres of the CST and the posterior thalamic radiation (PTR), a nonmotor tract.

OUTCOMEFibre tractography was successfully performed in all normal volunteers and all patients except 1. The fibre bundles of the CST, but not the PTR, were significantly reduced (P <0.05) in patients compared to normal volunteers.

CONCLUSIONFibre tractography can visualise axonal degeneration in the CST and may provide supplementary information about upper motor neuron disease in ALS patients.

Amyotrophic Lateral Sclerosis ; pathology ; Case-Control Studies ; Diffusion Magnetic Resonance Imaging ; Echo-Planar Imaging ; Female ; Humans ; Male ; Middle Aged ; Nerve Degeneration ; pathology ; Pyramidal Tracts ; pathology

Objective To compare 16-slice multi-detector spiral computed tomography (MDCT) and breathhold 3D magnetic resonance (MR) coronary angiography in the visualization of coronary arteries and the accuracy of detecting significant (＞ 50%) coronary stenoses in patients with suspected coronary artery disease. Methods Forty patients were examined by 16-slice CT (GE, Lightspeedl6)and MR (GE,Twinspeed) within 3 days; 31 of them underwent conventional coronary angiography (CAG) within 2 weeks after CT and MR scan. CT was performed with 16× 1.25 mm detector collimation, 0.5 s rotation time and images were reconstructed at 60%-75% of the cardiac cycle. MR was performed with breath hold 3D FIESTA (TR4.0 ms, TE1.7 ms, flip angle 65, slice thickness 3 mm, FOV 280 mm, matrix 256× 192). Mean heart rate was 63 ± 5.8 bpm and β-blocker was used in 24 patients. MR and CT image quality was evaluated in 9 coronary segments (RCA1, RCA2, RCA3, LM, LAD1, LAD2, LAD3, LCX1, LCX2) using a four-point grading scale.Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for detection of significant stenosis using CAG as the gold standard. Results 16-slice CT showed higher image quality in most coronary segments except RCA2.Forty-three segments were diagnosed as significant stenosis by CAG, 36 and 27 of these were correctly detected by CT and MR respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of 16-slice CT and MR for detecting significant stenosis were 83 %, 84 %, 49 %, 97 % and 63 %, 90 %, 55 %, 93 %, respectively. Conclusion Sixteen-slice CT showed higher image quality in most coronary segments excepted for middle RCA. 16-slice CT had higher sensitivity than MR for detection of coronary significant stenosis, whereas MR had higher specificity than CT. Both CT and MR showed high negative predictive value,which is useful for excluding coronary stenosis in symptomatic patients.

BACKGROUND: The MRJ studies of acute myocardial infarction (AMI)were more frequently focused on the changes of myocardial perfusion. OBJECTIVE: To investigate the characteristics of infarction and myocardial reperfusion in MRI, and make comparison of them with the results of their staining pathologic sections. DESIGN: Completely randomized grouping design and randomized controlled study. SETTING: Magnetic Resonance Department of Air-force General Hospital of Chinese PLA and Radiological Department of General Hospital of Chinese PLA. MATERIALS: The experiment was completed in the Medical Animal Experimental Center, General Hospital of Chinese PLA in December 2003.Fourteen miniature pigs were divided into 2 groups: infarction group and reperfusion group with 7 pigs in each group. One-month before and after the operation, MRI was performed in order to strengthen the scanning examination. One-month after operation, axial plane pathologic slices, which were corresponding to the MRI, were given TTC and SE staining. According to the TTC staining results, samples of the infarcted myocardium (corresponding to the anterior wall of the left ventricular) and normal myocardium (corresponding to the posterior wall of the left ventricular) were taken and given HE staining to observe the extent of infracted myocardium. MAIN OUTCOME MEASURES: The changes in cardiac shape and function and the changes of myocardial T1 and T2 relaxation time. RESULTS: Fourteen Chinese miniature pigs were used with 7 in each group. ①Relaxation time of T1 and T2 of infarcted myocardium in infarction group was obviously longer than that of thenormal myocardium [1 159.54±78.67, (60.15±6.31) ms, 1 056.15±70.95, (47.46±7.94) ms, t=2.63,5.38, P＜ 0.05, 0.01] and that of the infarcted myocardium in reperfusion group was also obviously longer than that of normal myocardium [1 171.14±139.98,(56.64±6.16) ms, 1 074.64±97.61, (44.57±4.25) ms, t=2.64, 6.24, P ＜ 0.05,0.01].②MRI in single infracted myocardium and reperfused infracted myocardium was both changed obviously,but without significant differences in relaxation time and stress.Dilatation of left ventricle in single infracted group was more obviously than that in the reperfusion infracted group.③Theresult of MRI was coincidence with that examinated with TTC staining CONCLUSION:①MRI is a useful imaging modality in the evaluation of AMI and the left ventricle remodeling after myocardial infarction.②It is significant for reperfusion to treat remodeling of left ventricle after acute myocardium infarction.③There is good correlation between MRI and pathological examination.

Objective To observe the therapeutic effect of tumor necrosis factor ?(TNF ?) on C6 glioma using 1?H MR spectroscopy, and to evaluate the practical value of 1?H MR spectroscopy in observing therapeutic effect Methods C6 cell mixed with low boiling point argarous were inoculated in caudate nuclear in 33 rats by using sterotatic method By using high magnetic field spectrometer, high resolution 1?H MR spectroscopy was carried at a 3 day interval until 15 days after treatment with TNF ? The relative choline containing compound (Cho),N acetyl aspartate (NAA),creatine (Cr), Cho/Cr,NAA /Cr,and NAA/Cho were analyzed with statistic method Results The Cho decreased obviously 3 days after TNF ? treatment( P

Objective To evaluate the clinical value of MR spectroscopy in intracranial neoplasm. Methods 52 cases with brain neoplasm or recurrent neoplasm or non-tumor lesion confirmed by pathology were undergone proton MRS before stereotactic biopsy, or operation. Results Of 52 cases, 38 were neoplasm and 14 were nonneoplastic lesion, 34 of 38 brain tumor, 11 of 14 nonneoplastic lesion were diagnosed correctly. The characteristics on MRS of glioma were remarkable Cho increase and NAA decrease, Lac in the tumors and the central necrotic area was elevated. Metastasis: Cho increased,NAA disappeared or obviously decreased and Lac increased, but the peritumoral region was normal. Lymphoma: Cho increased, NAA decreased moderately, Lip presented, but the peritumoral region was normal. Demyelination lesion: slight or median decreased NAA and normal Cr, Lac increased slightly. All metabolism decreased or disappeared in radiation necrosis, Cho was relative high compared with NAA. Brain abscess: Lac increased in the centre of abscess and perilesion was normal.Conclusion MRS has significant value in detecting and differentiating brain lesions.