2005年 · 第118卷第10期

Stem cells are defined by two important characteristics: the ability to proliferate by a process of self-renewal and the potential to form at least one specialized cell type. Transient population of pluripotent or multipotent stem cells first appear during the development at the first days post coitum. The cells of the inner cell mass (ICM) of the blastocyst, of which embryonic stem cells (ES) are the in vitro counterpart, can give rise to any differentiated cell type in the three primary germ layers of the embryo (endoderm, mesoderm and ectoderm).1-3 These cells gradually mature into committed, organ- and tissue-specific stem cells or adult stem cells, such as neural stem cells, mesenchymal stem cells, hematopoietic stem cells, etc. Over the past years, studies have focused on two aspects: molecular level and application, and some new methods and technology have been used。

Abstract：Background Triple-phase enhancement of multi-slice computed tomography (MSCT) has markedly improved the diagnostic accuracy of hepatocellular carcinoma (HCC), and MSCT angiography (MSCTA) has been proved useful in detecting vascular anatomy noninvasively. This study aimed to explore the value of MSCTA by triple-phase enhancement in preoperative evaluation of HCC.Methods Fifty-six consecutive cases of primary HCC scheduled for resection were studied with MSCTA by triple-phase enhancement. The raw data images were processed on a workstation for multiplanar reconstruction (MPR) and three-dimensional (3D) reconstruction. The findings after processing of the data were compared with those after surgery or intraoperative sonography. Results The false positive rate of MSCTA by triple-phase enhancement was 10.1% and its false negative rate was 4.3% in detecting HCC. No significant difference was observed in MSCTA and surgery or intraoperative sonography in detecting vascular anatomy anomalies and pathologic variations, whereas significant difference was found in detecting bile duct invasion with MSCT compared to intraoperative sonography.Conclusions MSCTA by triple-phase enhancement not only improves the detection of HCC, but also provides valuable preoperative information about hepatic vascular architecture and parenchyma. MSCTA by triple-phase enhancement is worthy of application as a non-invasive method in preoperative evaluation of HCC。

Abstract：Background Dominantly inherited spinocerebellar ataxia (SCA) is a clinically and genetically heterogeneous group of neurodegenerative disorders. This study was to further assess the frequency of SCA1 (spinocerebellar ataxia type 1), SCA2, SCA3/MJD (spinocerebellar ataxia type 3/Machado-Joseph disease), SCA6, SCA7, SCA8, SCA10, SCA12, SCA14, SCA17 and DRPLA (dentatorubro-pallidoluysian atrophy) in mainland Chinese, and to specifically characterize mainland Chinese patients with SCA6 in terms of clinical and molecular features.Methods Using a molecular approach, we investigated SCA in 120 mainland Chinese families with dominantly inherited ataxias and in 60 mainland Chinese patients with sporadic ataxias. Clinical and molecular features of SCA6 were further characterized in 13 patients from 4 families. Results SCA3/MJD was the most common type of autosomal dominant SCA in mainland Chinese, accounting for 83 patients from 59 families (49.2%), followed by SCA2[8(6.7%)], SCA1[7(5.8%)], SCA6[4(3.3%)], SCA7[1(0.8%)], SCA8(0%), SCA10(0%), SCA12(0%), SCA14(0%), SCA17(0%) and DRPLA(0%). The genes responsible for 41 (34.2%) of dominantly inherited SCA families remain to be determined. Among the 60 patients with sporadic ataxias in the present series, 3 (5.0%) was found to harbor SCA3 mutations while none was found to harbor SCA6 mutations. In the 4 families with SCA6, significant anticipation was found in the absence of genetic instability on transmission.Conclusion A geographic cluster of families with SCA6 subtype was initially identified in a mainland Chinese population.

Abstract：Background Microvascular Decompression (MVD) operation is the most reliable treatment for hemifacial spasm (HFS), but it causes many complications. The aim of this retrospective study was to investigate the factors relavent to the effects and postoperative complications of microvascular decompression on hemifacial spasm. Methods A total of 1200 HFS patients treated with MVD were studied retrospectively. The root exit zone (REZ) of the facial nerve was exposed through the infraflocculus approach, the offending vessels were identified and separated from the REZ, and a Teflon graft was interposed between the offending vessels and the brain stem. Brain stem auditory evoked potential (AEP) was monitored intraoperatively. Results The offending vessels can be identified in all patients. The anteroinferior cerebellar artery was the main offending vessel (42.6%). Patients with vertebral artery compression had a multiple vascular compression fashion. Follow-up for 2-10 years (mean 4.2 years) showed that 88.7% patients were cured and 5.6% relieved, with an effective rate of 94.3%. Recurrence rate was 3.2%, and the ineffective rate was 2.6%. The most frequent complication was hearing dysfunction (2.8%). Conclusions MVD is the most definitive treatment method of HFS. The key procedures of this operation include adequate exposure of the REZ, identification of the offending vessels, and proper positioning of Teflon grafts. Complications can be reduced effectively by utilizing a real-time AEP monitoring during the operation。

Abstract：Background Since there are a complex anatomic structure and vital function in the high cervical spinal cord, it is difficult to remove the tumors lateroventral and ventral to the high cervical spinal cord. This clinical study was undertaken to analyze surgical approaches, manner of tumor resection and postoperative management. Methods Thirty-four patients underwent microsurgical excision of tumors lateroventral and ventral to the high cervical spinal cord by means of three approaches. The tumors comprised mostly Schwannoma and meningioma (88.24%, 30/34) in this group. Tumor volume varied from 3.0 cm×2.5 cm×2.0 cm to 12 cm×3.0 cm×2.5 cm. Of the 34 patients, 4 had dumbbell-shaped tumors growing outside the spinal canal and 7 tumors growing into the intracranium. Results The tumor was totally removed in 32 patients (94.1%). Follow-up for 7 months to 6.4 years (median 3.6 years) showed a recovery of a normal life or work ability in 30 (83.3%) patients. Conclusion Modified operative approaches and microsurgical techniques can raise the rate of total tumor removal and reduce the disability of patients.

Abstract：Background Magnetic targeting therapy may be a new method for the treatment of malignent tumors. The purpose of this study was to investigate the localization and distribution of ferrofluid microsphere of human serum albumin methotrexate (FM-HSA-MTX) carriers in the brain and to explore the magnetic targeting chemotherapy for malignant brain tumor. Methods Ninety SD rats were divided into three groups: targeting group, non-magnetic targeting group, and control group. Synthesized FM-HSA-MTX carriers (MTX 25 mg/kg) were injected into the systemic circulation via the caudal vein (magnetic targeting group, n=30). A 0.6 T magnetic field was placed around the right hemisphere. The non-magnetic targeting group (n=30) was administered with FM-HSA-MTX without external magnetic field, meanwhile the control group (n=30) was treated with MTX and a magnetic field. Random serial sacrifices (n=10) were conducted at 15, 30 and 45 minutes after drug administration. Bilateral hemispheres were collected respectively, and analyzed for total MTX content. Results MTX content in the right hemisphere of the magnetic targeting group was significantly higher than that in the other two groups at 15, 30 and 45 minutes after drug administration (P＜0.05) No difference was seen between the non-targeting group and control group. In the magnetic targeting group, MTX returned to the peak level [(0.564±0.018) mg/g, q15-45=32.252, P＜0.05] 45 minutes after the injection but it deceased in the other two groups [non-magnetic targeting group: (0.060±0.015) mg/g, q15-45=9.245, P＜0.05, control group: (0.074±0.045) mg/g, q15-45=6.299, P＜0.05]. In the magnetic targeting group, the concentration of MTX in the right hemisphere was significantly higher than that in the left hemisphere (t45min=21.135, P=0.000) but no difference was observed between bilateral hemispheres in the other two groups (non-magnetic targeting group: t45min=0.434, P=0.670; control group: t45min=0.533, P=0.600). Conclusion In the presence of the external magnetic field, FM-HSA-MTX can distribute successfully in the targeting areas of the brain。

Abstract：Background 5-dihydroxyanthraquinone-2-carboxylic acid (rhein) inhibits oxidoreduction induced by reducing nicotingamide adenine dinucleotide in the mitochondria and reducing reactive oxygen species, it also suppresses lipid peroxidation in rat brain homogenates. This study was to assess the effects of anthraquinone derivatives, rhein on synaptic transmission in the rat hippocampal CA1 pyramidal cell layer by intracellular recording.Methods The excitatory postsynaptic potential (EPSP) evoked by stimulation of the Schaffer collaterals in the presence of bicuculline (15 μmol/L) was depressed by application of rhein (0.3-30 μmol/L). The amplitude of the EPSP was restored within 20 minutes after removal of rhein from the supernatant. At a concentration of 30 μmol/L, rhein reduced the amplitude of the EPSP to 42%±3.7% (n=24) of the control. Subsequently, wavelet spectral entropy was used to analyze the EPSP. Results A strong positive correlation was observed between the wavelet spectral entropy and other parameters such as amplitude, slope of rising phase and slope of descending phase of the EPSP. The paired-pulse facilitation (PPF) of the EPSP was significantly increased by rhein (30 μmol/L). The inhibitory postsynaptic potential (IPSP) recorded in the presence of CNQX (20 μmol/L) and APV (40 μmol/L) is not altered by rhein (30 μmol/L). Conclusions Rhein (30 μmol/L) can decrease the frequency but not the amplitude of the miniature EPSP (mEPSP). It is suggested that rhein inhibits excitatory synaptic transmission by decreasing the release of glutamate in rat hippocampal CA1 pyramidal neurons。

Abstract：Background Tumor involving the septum pellucidum is uncommon. Surgery as the main therapeutic procedure for this lesion is a challenge to neurosurgeons. We analyzed the clinical characteristics and pathological features of septum pellucidum tumor in 41 patients and compared the curative effects of frontal transcortical, trans-sulcal and interhemispheric transcallosal approaches. Methods Clinical characteristics and the pathological features of septum pellucidum tumor were investigated retrospectively in 41 patients. The differences in postoperative residual rates, extents of tumors and resection of normal brain tissues after use of the three approaches in these patients were analyzed statistically. Results Septum pellucidum tumor is more likely to attack young or middle-aged persons. The tumor mainly presents itself as a central neurocytoma or cerebral low-grade glioma in pathology and manifests as intracranial hypertension clinically. No difference was found in the extent of tumor resection but significant difference in the extent of normal brain tissue resection and in postoperative disability rate among the three approaches. The transcortical approach brought about the most serious injury to brain tissue and the highest disability rate, Whereas the frontal transcallosal approach the lightest injury and the lowest disability rate. The injury to brain tissue and the disability rate brought about by the front trans-sulcus approach were between the above two approaches. Conclusions Operation is still regarded the major treatment for septum pellucidum tumor. Transcallosal and trans-sulcus approaches are fit with the concept of minimally invasive surgery, and transcallosal approach is the first choice for septum pellucidum tumor。

Abstract：Background Craniopharyngioma of the third ventricle is difficult to treat and its therapeutic regimens and operative approaches have been controversial. This study was undertaken to probe indications for microsurgical resection of craniopharyngioma of the third ventricle via an improved transventricular approach, its surgical procedures and therapeutic effects, and prevention of postoperative complications.Methods Fifty-one patients with craniopharyngioma of the third ventricle were treated from January 2000 to October 2004 by an improved transventricular approach for removing the tumor via the interventricular foramen,the intermedius of the septum pellucidum or choroid fissure. Symptoms and signs of the patients, and results of imaging, operation, and follow-up were analyzed. Results Of the 51 patients who had received the improved transventricular resection, 4 underwent a combined approach with an entrance of the pterion. Forty patients (78.43%) underwent total resection and others subtotal resection, without an operative death. Epileptic seizures were found in 3 patients (5.88%) and subdural effusion in the operative field in 4 (7.84%). All patients showed good general conditions after operation, and follow-up for an average of 27.52 months showed relapse of the tumour in 8 patients (15.69%).Conclusions Microsurgical resection of craniopharyngioma of the third ventricle by an improved transventricular approach has advantages of operative safety and efficacy, lower mortality and disability, and less complications.

Abstract：Background This investigation was undertaken to obtain differentially expressed genes related to human glioma using cDNA microarray and the characterization of one novel full-length gene. Methods Total RNA was extracted from human glioma tissues and normal brain tissues, and mRNA was used to make probes. After hybridization and washing, the results were scanned using a computer system. The gene named 681F05 clone was an expressed gene to human glioma through four-time hybridization and scanning. Subsequently northern blot analysis was performed by northern blot, 5'RACE and bioinformatics. Results Fifteen differentially expressed genes to human glioma were obtained through four-time hybridization and scanning. Northern blot analysis confirmed that 681F05 clone was low-expressed in human brain tissues and over-expressed in human glioma tissues. The analysis of BLASTn and BLASTx showed that 681F05 clone is two cDNA clones encoding two novel proteins that are highly identified to the cyclophilin isoform 10 of C. Elgans, respectively. Sequence analysis revealed the two cDNA clones are two different splicing variants of a novel cycophilin-like gene (PPIL3a and PPIL3b).Conclusions cDNA microarray technology can be successfully used to identify differentially expressed genes. The novel full-length gene of human PPIL3 may be correlated with the formation of human glioma。

Severe acute respiratory syndrome coronavirus (SARS-CoV) is a highly aggressive pathogen that caused SARS in 2003 and 2004.1-4 Spike protein (S) on the surface of virus particles mediates the attachment of the virus to cell surface receptors and induces the fusion of viral and cellular membranes. According to the epitope analysis and structure of S protein, we used two fragments of S protein S1 (108-488aa) and S2 (723-938aa) expressed in Escherichia coli and immunized Balb/c mice to investigate the immune response to the recombinant proteins in mice。

The pathogenesis of childhood primary nephrotic syndrome (PNS) is unclear. However, an immune mechanism has generally been accepted as a cause. Imbalance of T lymphocyte and a variety of inflammatory cytokines, chemotactic and transcription factors are involved in the pathophysiology and manifestations of PNS,1,2 and nuclear factor kappa B (NF-κB) transcriptionally regulates the expression of these factors.3 Research has been focused on NF-κB and inflammatory regulated mediators of renal diseases, but seldom on different clinical manifestations and histopathological changes. In order to explore a potential mechanism for the pathogenesis of PNS in children and a basis for preventing its advance, we determined NF-κB activity in the kidney of children with PNS in vitro using immunohistochemical staining and the multimedia coloured pathological image analysis system and its relations to clinical manifestations, histopathological changes and 24-hour urinary protein excretion。

Rat testis transplantation with a segment of donor abdominal aorta end-to-side anastomosed to recipient's abdominal aorta was first reported by Lee.1 But thrombus was formed in the donor abdominal aorta segment. Goldsein2 and Lee3 improved this technique using end-to-side anastomosis of an aortic patch with the testicular artery to the recipient's aorta and the testicular vein was anastomosed to the vena cava of the recipient. With this method, the animal with the testicular artery and vein paralleling and originating no more than 4 mm apart is considered a suitable donor, which is scarce because of the variability of testicular vessels. This problem limits the wide use of testicular transplantation in rats. Based on these findings, we established a novel testicular transplantation model which was recreated as closely as possible to the normal vascular anatomy of the testis in rats. The functional activities of these transplants were also presented。

Nonfunctional pheochromocytoma is a particular type of pheochromocytoma without typical clinical features of catecholaminism. It is difficult to diagnose or differentially diagnose. This type of pheochromocytoma is rarely reported in the literature. From January 1, 1990 to June 1, 2004, we performed operations for 197 patients with pheochromocytomas, including 26 patients with nonfunctional pheochromocytoma. We analyzed the clinical data of the 26 patients。

Psoriasis is a common disease with a prevalence of up to 2% in the world population.1 The pathophysiological mechanism of this inflammatory disease has not been determined although it is generally accepted to have a genetic predisposition and be T-cell mediated. The lymphocytes are the target of psoriatic therapeutic strategies. Therapy resolves psoriasis for a time, but induces some severe side effects. Some cases of severe psoriasis, treated with multiple therapeutic regimens for many years, developed leukemia.

Retroperitoneal hematoma is an obligatory complication in pelvic ring fracture.1 In most cases, the bleeding originates from venous vessels of the presacral plexus, small arteries and veins from fracture fragments. External fixation of the pelvis can control blood loss by reducing diastasis and dramatically decreasing the volume of the pelvis. But this tamponade effect can not prevent the presence of hematoma in the adjoining retroperitoneal space. It is well known that complication of retroperitoneal hematoma is infection and sepsis。

Primary torsion dystonia (PTD) is a clinically and genetically heterogeneous movement disorder. At least thirteen different types of dystonia can be distinguished on a genetic basis.1 The DYT1 gene was first mapped by Ozelius et al in 1989.2 Kramer et al3 linked the same locus to PTD in 12 Ashkenazi Jewish families in 1990. Most patients with early-onset generalized PTD were caused by the same three base pair (GAG) deletion in the DYT1 gene on chromosome 9q34.1,4,5 The product of the gene is a protein called torsinA.5 Although the function of this protein is as yet uncertain, it is widely distributed throughout the brain with high levels in the substantia nigra compacta dopamine neurones。

Severe liver diseases usually cause menstrual dysfunction and infertility in women of reproductive age. Liver transplantation is one of the treatment choices for patients with liver diseases. Among patients receiving liver transplantation, 11% are women of reproductive age.1 Successful liver transplantation, suitable immunosuppressive age-nts, and intensive monitoring after the operation may help these patients to have a successful pregnancy. Since 1978, 37 cases have been reported worldwide,1 of which none was in China. We report here in the first case in China. Two characteristics of this case are visible: (a) no consultation from obstetricians before or during pregnancy and (b) severe complications of pregnancy, which were dangerous to her baby and herself. Although the patient and baby were discharged from the hospital in a good condition, this case has drawn our attention to the fact that it is very important for a patient following liver transplantation to consult obstetrician and hepatologist before and during pregnancy.

The Chinese Medical association (CMA) celebrated its 90th founding anniversary from April 12 to 14, 2005. The 23rd Congress of the CMA was held at the same time. Five hundred and sixty CMA member representatives from the mainland of China and 122 guests from Hong Kong, Macao, Taiwan Province and other countries attended the celebration. In addition, 89 specially invited persons presented at the congress. Also at the jubilee were some officers including vice Minister of the Ministry of Civil Affairs Jiang Li, Director of the State Durg and Food Administration Zheng Xiao-yu, vice Ministers of the Ministry of Public Health Wang Long-de, Jiang Zuo-jun, Yu Jing, Huang Jie-fu, Zhang Feng-lou, and Chen Xiao-hong, and the Honorary Chairman Wu Jie-ping。