ObjectiveThis paper aims to evaluate the intervention effect of Gandou Fumu Decoction （GDFMD） in treating hepatolenticular degeneration with liver fibrosis of liver-kidney deficiency and phlegm-blood stasis syndrome， thereby providing evidence-based medical evidence for the treatment of Wilson's disease （WD）-related liver fibrosis with traditional Chinese medicine through clinical efficacy analysis. MethodsA total of 70 patients with WD-related liver fibrosis of liver-kidney deficiency and phlegm-blood stasis syndrome meeting the inclusion criteria were enrolled from Anhui Provincial Hospital of TCM from October 1， 2023， to October 1， 2024. Participants were divided into a control group and an observation group， with 35 cases in each group. The control group received conventional copper chelation therapy with sodium dimercaptopropanesulfonate （DMPS）. On this basis， the observation group was additionally administered GDFMD orally. Each treatment course lasted eight days， for a total of four treatment courses. Efficacy evaluations were performed before treatment and after the second and fourth treatment courses， respectively. The clinical efficacy and safety of GDFMD in the treatment of WD-related liver fibrosis were assessed by comparing the changes in liver stiffness measurement （LSM）， liver serological markers ［alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， type Ⅳ collagen （C-Ⅳ）， laminin （LN）， N-terminal propeptide of type Ⅲ procollagen （PⅢNP）， and hyaluronic acid （HA）］， fibrosis index based on 4 factors （FIB-4）， AST to platelet ratio index （APRI）， unified Wilson's disease rating scale part Ⅱ （UWDRS-Ⅱ）， traditional Chinese medicine （TCM） syndrome score， 24-hour urinary copper， and safety indicators between the two groups before and after treatment. ResultsCompared with those before treatment， LSM levels decreased in both groups after two and four treatment courses （P<0.05）. Compared with those after treatment， there was no statistically significant difference in the improvement of LSM levels in the observation group after two treatment courses， and the improvement of LSM levels in the observation group was more obvious after four treatment courses （P<0.05）. Compared with those before treatment， the levels of HA， LN， PⅢNP， and C-Ⅳ decreased in both groups after two and four treatment courses （P<0.05）. Compared with those after treatment， there was no statistically significant difference in the improvement of the C-Ⅳ levels in the observation group after two treatment courses， and the levels of HA， LN， and PⅢNP were more obvious （P<0.05）. After four treatment courses in the observation group， the levels of HA， LN， PⅢNP， and C-Ⅳ were improved more significantly （P<0.05）. Compared with those before treatment， ALT and AST levels decreased in both groups after two and four treatment courses （P<0.05）. Compared with the control group after treatment， there was no statistically significant difference in the improvement of ALT and AST levels in the observation group after two treatment courses， and the improvement of ALT and AST levels in the observation group was more obvious after four treatment courses （P<0.05）. Compared with those before treatment， APRI score and FIB-4 index level decreased in both groups after two and four treatment courses （P<0.05）. Compared with those in control group after treatment， there was no statistically significant difference in the improvement of APRI score and FIB-4 index level in the observation group after two treatment courses， and the APRI score in the observation group was more obvious after four treatment courses （P<0.05）， with no statistically significant improvement in the FIB-4 index difference. Compared with those before treatment， the levels of TCM syndrome scores decreased in both groups after two and four treatment courses （P<0.05）. Compared with that of the control group after treatment， there was no statistically significant difference in the improvement of the level of TCM syndrome scores in the observation group after two treatment courses， and the improvement of the level of TCM syndrome scores in the observation group was more obvious after four treatment courses （P<0.05）. Compared with those before treatment， the UWDRS-Ⅱ scores in both groups after two treatment courses were not improved obviously， and the UWDRS-Ⅱ scores in both groups decreased after four treatment courses （P<0.05）. Compared with those of the control group after treatment， there was no statistically significant difference in the improvement of the UWDRS-Ⅱ scores in the observation group after two treatment courses， and the improvement of the UWDRS-Ⅱ scores in the observation group after four treatment courses was more obvious （P<0.05）. Compared with those before treatment， the 24-h urine copper levels were significantly higher in both groups after two and four treatment courses （P<0.05）. Compared with those in the control group after treatment， the 24-h urine copper levels in the observation group were significantly higher after two and four treatment courses （P<0.01）. After two treatment courses， the 24-h urine copper level in the observation group showed a gradual decreasing trend， although it was higher than that before treatment. After four treatment courses， the control group had an improvement rate of 91.43%， an effective rate of 34.29%， and an apparent rate of 2.86%. The observation group had an improvement rate of 94.29%， an effective rate of 71.43%， and an apparent rate of 8.57%. The efficacy of the observation group was better than that of the control group （P<0.05）. Conclusion① The efficacy of GDFMD combined with DMPS therapy in patients with WD-related liver fibrosis of liver-kidney deficiency and phlegm-blood stasis syndrome is significantly better than that of single DMPS therapy， and the advantages of the combined therapy are more obvious with the prolongation of the treatment cycle. ② GDFMD combined with the DMPS therapy program in the long-term application exhibits no obvious adverse reactions with good safety， which is worthy of clinical popularization and application.

ObjectiveThis paper aims to evaluate the intervention effect of Gandou Fumu Decoction （GDFMD） in treating hepatolenticular degeneration with liver fibrosis of liver-kidney deficiency and phlegm-blood stasis syndrome， thereby providing evidence-based medical evidence for the treatment of Wilson's disease （WD）-related liver fibrosis with traditional Chinese medicine through clinical efficacy analysis. MethodsA total of 70 patients with WD-related liver fibrosis of liver-kidney deficiency and phlegm-blood stasis syndrome meeting the inclusion criteria were enrolled from Anhui Provincial Hospital of TCM from October 1， 2023， to October 1， 2024. Participants were divided into a control group and an observation group， with 35 cases in each group. The control group received conventional copper chelation therapy with sodium dimercaptopropanesulfonate （DMPS）. On this basis， the observation group was additionally administered GDFMD orally. Each treatment course lasted eight days， for a total of four treatment courses. Efficacy evaluations were performed before treatment and after the second and fourth treatment courses， respectively. The clinical efficacy and safety of GDFMD in the treatment of WD-related liver fibrosis were assessed by comparing the changes in liver stiffness measurement （LSM）， liver serological markers ［alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， type Ⅳ collagen （C-Ⅳ）， laminin （LN）， N-terminal propeptide of type Ⅲ procollagen （PⅢNP）， and hyaluronic acid （HA）］， fibrosis index based on 4 factors （FIB-4）， AST to platelet ratio index （APRI）， unified Wilson's disease rating scale part Ⅱ （UWDRS-Ⅱ）， traditional Chinese medicine （TCM） syndrome score， 24-hour urinary copper， and safety indicators between the two groups before and after treatment. ResultsCompared with those before treatment， LSM levels decreased in both groups after two and four treatment courses （P<0.05）. Compared with those after treatment， there was no statistically significant difference in the improvement of LSM levels in the observation group after two treatment courses， and the improvement of LSM levels in the observation group was more obvious after four treatment courses （P<0.05）. Compared with those before treatment， the levels of HA， LN， PⅢNP， and C-Ⅳ decreased in both groups after two and four treatment courses （P<0.05）. Compared with those after treatment， there was no statistically significant difference in the improvement of the C-Ⅳ levels in the observation group after two treatment courses， and the levels of HA， LN， and PⅢNP were more obvious （P<0.05）. After four treatment courses in the observation group， the levels of HA， LN， PⅢNP， and C-Ⅳ were improved more significantly （P<0.05）. Compared with those before treatment， ALT and AST levels decreased in both groups after two and four treatment courses （P<0.05）. Compared with the control group after treatment， there was no statistically significant difference in the improvement of ALT and AST levels in the observation group after two treatment courses， and the improvement of ALT and AST levels in the observation group was more obvious after four treatment courses （P<0.05）. Compared with those before treatment， APRI score and FIB-4 index level decreased in both groups after two and four treatment courses （P<0.05）. Compared with those in control group after treatment， there was no statistically significant difference in the improvement of APRI score and FIB-4 index level in the observation group after two treatment courses， and the APRI score in the observation group was more obvious after four treatment courses （P<0.05）， with no statistically significant improvement in the FIB-4 index difference. Compared with those before treatment， the levels of TCM syndrome scores decreased in both groups after two and four treatment courses （P<0.05）. Compared with that of the control group after treatment， there was no statistically significant difference in the improvement of the level of TCM syndrome scores in the observation group after two treatment courses， and the improvement of the level of TCM syndrome scores in the observation group was more obvious after four treatment courses （P<0.05）. Compared with those before treatment， the UWDRS-Ⅱ scores in both groups after two treatment courses were not improved obviously， and the UWDRS-Ⅱ scores in both groups decreased after four treatment courses （P<0.05）. Compared with those of the control group after treatment， there was no statistically significant difference in the improvement of the UWDRS-Ⅱ scores in the observation group after two treatment courses， and the improvement of the UWDRS-Ⅱ scores in the observation group after four treatment courses was more obvious （P<0.05）. Compared with those before treatment， the 24-h urine copper levels were significantly higher in both groups after two and four treatment courses （P<0.05）. Compared with those in the control group after treatment， the 24-h urine copper levels in the observation group were significantly higher after two and four treatment courses （P<0.01）. After two treatment courses， the 24-h urine copper level in the observation group showed a gradual decreasing trend， although it was higher than that before treatment. After four treatment courses， the control group had an improvement rate of 91.43%， an effective rate of 34.29%， and an apparent rate of 2.86%. The observation group had an improvement rate of 94.29%， an effective rate of 71.43%， and an apparent rate of 8.57%. The efficacy of the observation group was better than that of the control group （P<0.05）. Conclusion① The efficacy of GDFMD combined with DMPS therapy in patients with WD-related liver fibrosis of liver-kidney deficiency and phlegm-blood stasis syndrome is significantly better than that of single DMPS therapy， and the advantages of the combined therapy are more obvious with the prolongation of the treatment cycle. ② GDFMD combined with the DMPS therapy program in the long-term application exhibits no obvious adverse reactions with good safety， which is worthy of clinical popularization and application.

Objective To investigate the distribution characteristics of Oncomelania hupensis snails in Yunnan Province fol-lowing interruption of schistosomiasis transmission, so as to provide the evidence for assessing the risk of schistosomiasis transmission and scientifically formulating the schistosomiasis surveillance program. Methods According to the requirements of the National Schistosomiasis Surveillance Scheme (2020 Edition), O. hupensis snail surveillance data were collected from 18 schistosomiasis-endemic counties (cities, districts) in Yunnan Province from 2020 to 2024, including area of snail survey, area of snail habitats, area of re-emerging snail habitats, number of frames surveyed, number of frames with O. hupensis snails, number of O. hupensis snails captured, and number of living snails, and the occurrence of frames with snails and mean density of living snails were calculated. Changes in snail status over the 5-year period from 2020 to 2024 and the differences in snail distributions specified by epidemic intensity, environmental type, and vegetation type were analyzed. Results The areas of snail survey increased from 1 727.96 hm² in 2020 to 3 894.45 hm² in 2024 (peak) across 18 schistosomiasis-endemic counties (cities, districts) in Yunnan Province during the period from 2020 through 2024. The areas of snail habitats increased from 70.36 hm² in 2020 to a peak in 2023 (172.04 hm²), followed by a reduction to 132.36 hm² in 2024, and the areas of re-emerging snail habitats increased from 42.71 hm² in 2020 to a peak in 2022 (78.43 hm²), followed by a reduction to 40.21 hm² in 2024. The occurrence of frames with snails and mean density of living snails increased from 1.24% (3 025/244 404) and (0.033 2 ± 0.038 7) snails/0.1 m² in 2020 to peaks at 2.03% (6 231/307 563) and (0.066 9 ± 0.068 4) snails/0.1 m² in 2023, followed by reductions to 1.04% (5 829/559 941) and (0.032 6 ± 0.057 7) snails/0.1 m² in 2024, respectively. There was a significant difference in the occurrence of frames with snails over the 5-year study period (χ² = 1 962.95, P < 0.05), and the occurrence of frames with snails reduced by 48.71% in 2024 relative to in 2023 (χ² = 1 411.05, P < 0.005); however, there was no significant difference in the mean density of living snails over the 5 years (H = 5.310, P > 0.05). There were significant differences in the occurrence of frames with snails (χ² = 481.27, P < 0.05) and mean density of living snails (H = 6.872, P < 0.05) in schistosomiasis-endemic areas with different epidemic intensities. The occurrence of frames with snails (χ² = 25.32 and 38.70, both P values < 0.017) and mean density of living snails (Z = 28.55 and 49.96, both P values < 0.017) were higher in schistosomiasis transmission-interrupted and eliminated areas with snails than in schistosomiasis-eliminated areas without snails, and the occurrence of frames with snails (χ² = 453.54, P < 0.017) and mean density of living snails (Z = −56.97, P < 0.017) were higher in schistosomiasis-eliminated areas with snails than in schistosomiasis transmission-interrupted areas with snails. O. hupensis snails were mainly distributed in paddy fields, dry farmlands and ditches; however, the occurrence of frames with snails (13.40%, 424/3 164) and mean density of living snails [(0.252 8 ± 0.158 7) snails/0.1 m²] were higher in ponds/weirs than in other types of environments (both P values < 0.05). Rice, dry farmland crops and weeds were main vegetations in which O. hupensis snails were distributed, and the occurrence of frames with snails (2.29%, 7 111/310 140) and mean density of living snails [(0.072 3 ± 0.018 9) snails/0.1 m²] were higher in weeds than in other types of environments (both P values < 0.05). Conclusions O. hupensis snails have been effectively controlled in Yunnan Province following implementation of integrated schistosomiasis control measures; however, there are still risk factors for schistosomiasis transmission, including reduced attention to schistosomiasis control and snail re-emergence. Improved control efforts and surveillance system construction and timely identification of risk factors of snail status and timely management are recommended to ensure the achievement of the target of schistosomiasis elimination as scheduled.

Apurinic/apyrimidinic endonuclease 1(APE 1)is a multifunctional protein that plays important roles in DNA repair and regulation of gene expression.Because APE 1 is overexpressed in various cancers,it can serve as a cancer biomarker for aiding clinical diagnosis,guiding therapy,and monitoring prognosis.On this basis,a label-free fluorescent probe was designed based on the primer exchange reaction(PER)strategy for highly sensitive detection of APE 1 activity.In the absence of APE 1,the structure of catalytic hairpin(HP)was stable and could not form G-quadruplex.Therefore,the background fluorescence of this sensing system was very low due to the dissociation of thioflavin T(ThT).In the presence of APE 1,the apurinic/apyrimidinic(AP)site of HP was cleaved by APE 1 and a short nucleic acid fragment that acted as a primer to initiate PER was generated.After PER reaction,a large number of G-quadruplex were produced,which could specifically bind with ThT and resulted in significant increase of fluorescence signal.The combination of low background design of HP and PER amplification made this biosensor had high sensitivity with a detection limit(3σ)of 0.0008 U/mL.Furthermore,the primer sequence was directly generated by the cleavage of APE 1 without additional addition,which not only increased the specificity of the reaction,but also simplified the experiment procedure.Moreover,the use of label-free fluorescence signal reduced the cost of the experiment,and realized rapid detection of APE 1.Finally,this sensor was used to detect APE 1 in human serum samples with spiked recoveries of 91%-104%,proving great potential in study of biological enzyme.

Cryopreservation is the primary technique for in vitro preservation of allogeneic tissue. However, its success is often hindered by factors such as low temperature, ischemia, and hypoxia. This study investigated the potential of Sini Decoction, known for its antioxidant and anti-apoptotic properties, to reduce cryopreservation-induced injury in rats' sciatic nerves. Sini Decoction was prepared according to the Chinese Pharmacopoeia, and its cytotoxicity on Rsc96 cells was assessed by using the CCK-8 method. Sini Decoction at concentrations of 4, 8, and 16 mg·mL~(-1), termed as low-(SL), medium-(SM), and high-(SH) doses group, was used for cryopreservation of rats' sciatic nerves. A normal control(NC) group and a fresh nerve control(fresh) group were set. Flow cytometry and TUNEL staining were used to detect the apoptosis of neural tissue cells after cryopreservation. Western blot was used to detect the expression of apoptosis-related proteins(Bcl-2, Bax, caspase-3, and caspase-8) and nerve regeneration proteins(NGF and BDNF) in vitro after cryopreservation. Oxidative damage of neural tissue after cryopreservation was evaluated by measuring levels of GSH, SOD, MDA, ROS, and ATP. Cryopreserved nerves were then used for allogeneic transplantation. One week after transplantation, CD4~+ and CD8~+ fluorescent double staining assessed inflammatory cell invasion in the transplanted nerve segment, and ELISA evaluated the expression of serum inflammatory factors(IL-1, IFN-γ, and TNF-α) in recipients. Twenty weeks after transplantation, electrophysiology and NF200 neurofilament staining were used to evaluate nerve regeneration. RESULTS:: showed that Sini Decoction at concentrations of below 32 mg·mL~(-1) exhibited no cytotoxicity to Rsc96 cells. During in vitro nerve cryopreservation, Sini Decoction significantly reduced cell apoptosis, ROS, and MDA production compared to the NC group. In the SH group, the protein expression of NGF and BDNF in vitro, as well as ATP, SOD, and GSH production, were significantly increased. In the rejection reaction one week after transplantation, compared to the fresh nerve transplantation group, the SL and SM groups showed reduced CD4~+ and CD8~+ T cell invasion in the transplanted nerve segment and down-regulated IL-1, IFN-γ, and TNF-α expression in recipient serum. Twenty weeks after transplantation, the electrophysiological test results of CMAP, NCV, and NF200 neurofilament protein fluorescent staining in the SM and SH groups were superior to those in the NC and fresh groups. These findings indicate that Sini Decoction offers protective benefits in the cryopreservation of rats' sciatic nerves and holds significant potential for the in vitro preservation of tissue and organs.
Animals ; Apoptosis/drug effects* ; Rats ; Oxidative Stress/drug effects* ; Sciatic Nerve/cytology* ; Cryopreservation ; Drugs, Chinese Herbal/administration & dosage* ; Male ; Rats, Sprague-Dawley ; Protective Agents/pharmacology*

This study aimed to characterize and identify the non-volatile components in aqueous and ethanolic extracts of the stems and leaves of Rhododendron tomentosum by using sensitive and efficient ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry(UHPLC-Q-TOF-MS) combined with a self-built information database. By comparing with reference compounds, analyzing fragment ion information, searching relevant literature, and using a self-built information database, 118 compounds were identified from the aqueous and ethanolic extracts of R. tomentosum, including 35 flavonoid glycosides, 15 phenolic glycosides, 12 flavonoids, 7 phenolic acids, 7 phenylethanol glycosides, 6 tannins, 6 phospholipids, 5 coumarins, 5 monoterpene glycosides, 6 triterpenes, 3 fatty acids, and 11 other types of compounds. Among them, 102 compounds were reported in R. tomentosum for the first time, and 36 compounds were identified by comparing them with reference compounds. The chemical components in the ethanolic and aqueous extracts of R. tomentosum leaves and stems showed slight differences, with 84 common chemical components accounting for 71.2% of the total 118 compounds. This study systematically characterized and identified the non-volatile chemical components in the ethanolic and aqueous extracts of R. tomentosum for the first time. The findings provide a reference for active ingredient research, quality control, and product development of R. tomentosum.
Rhododendron/chemistry* ; Chromatography, High Pressure Liquid/methods* ; Drugs, Chinese Herbal/chemistry* ; Mass Spectrometry/methods* ; Plant Leaves/chemistry*

This study established the HPLC fingerprints, characteristic chromatograms, and a multi-component content determination method for Bidens bipinnata and B. biternata. The chemical pattern recognition analysis was then employed to clarify the characteristic indexes of quality differences between the two original plants of Bidentis Herba, providing a reference for establishing the quality standards of Bidentis Herba. HPLC was launched on an Agilent Poroshell 120 EC-C_(18) chromatographic column(4.6 mm×250 mm, 4 μm) by gradient elution with a mobile phase of 0.1% aqueous phosphoric acid-acetonitrile at a flow rate of 0.7 mL·min~(-1), detection wavelength of 270 nm, column temperature of 25 ℃, and an injection volume of 5 μL. The similarity between the fingerprints of 18 batches of Bidentis Herba samples and the common pattern(R) ranged from 0.572 to 0.933. A total of 23 chromatographic peaks were calibrated. Through comparison with the reference substances, six components(neochlorogenic acid, chlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, rutin, and hyperoside) were identified and subjected to quantitative analysis. The characteristic fingerprints of B. bipinnata and B. biternata were calibrated with 20 and 17 characteristic peaks, respectively. Among them, peaks 8, 9, 22, and 23 were the characteristic peaks of B. bipinnata, and peak 7 was the characteristic peak of B. biternata, which can be used to distinguish the two original plants of Bidentis Herba. The relative standard deviation of the content of the above-mentioned six components ranged from 36% to 123%. The cluster analysis, principal component analysis, and orthogonal partial least squares-discriminant analysis(OPLS-DA) classified the 18 batches of Bidentis Herba samples into two categories. Additionally, through the analysis of variable importance in projection(VIP) under OPLS-DA, three characteristic indexes, rutin, isochlorogenic acid A, and isochlorogenic acid B, were identified. The analytical method established in this study can comprehensively evaluate the consistency of Bidentis Herba samples derived from different original plants, specifically identify the differential components between them, and effectively distinguish the two original plants of Bidentis Herba, providing a basis for the differentiation between different original plants and the quality control of Bidentis Herba.
Chromatography, High Pressure Liquid/methods* ; Drugs, Chinese Herbal/chemistry* ; Quality Control ; Bidens/chemistry*

Objective: To investigate the hematological characteristics of the rare McLeod phenotype associated with X-linked chronic granulomatous disease, KEL and XK gene analysis, identification of unexpected antibodies, serological characteristics of high-frequency antigen antibodies, and transfusion strategies. Methods: Serological methods were employed to determine the ABO, Rh, and other blood group system antigen phenotypes of the child, along with screening and identification of unexpected antibodies. The titers of high-frequency antigen antibodies were measured using tube antihuman globulin and microcolumn gel card techniques. Kell blood group typing was performed using serological and genotyping methods, while XK gene sequencing was conducted via next-generation sequencing. Peripheral blood smears from the child's mother were examined for erythrocyte morphology. Results: The child's serological results were as follows: blood group O, ccDEE, MM, Le(a-b+), JK(a+b+), Fy(a+b-), and Kell phenotype K-k+, Kp(a-b+). Plasma analysis revealed alloantibodies anti-C、e, as well as a high-frequency antigen antibody anti-KL, with titers of 512 (tube method) and 2 048 (microcolumn gel method). Genotyping results showed KEL genotype K-k+, Kp(a-b+), Js(a-b+), while XK gene NGS identified a hemizygous deletion of exons 1-3 (XK N. 01), consistent with XK: -1 or Kx-(McLeod). The mother's peripheral blood smear exhibited prominent acanthocytes. Conclusion: The hematological features of this rare McLeod phenotype with X-CGD include weakened Kell antigen expression and a complete exon deletion in the XK gene. Early clinical attention should be given to the symptoms and laboratory diagnosis of X-linked chronic granulomatous disease in pediatric patients. XK genotyping for McLeod phenotype should be prioritized to guide cautious transfusion strategies, preventing life-threatening complications due to incompatible blood products.

Oligodendrocyte lineage cells, including oligodendrocyte precursor cells (OPCs) and oligodendrocytes (OLs), are essential in establishing and maintaining brain circuits. Autophagy is a conserved process that keeps the quality of organelles and proteostasis. The role of autophagy in oligodendrocyte lineage cells remains unclear. The present study shows that autophagy is required to maintain the number of OPCs/OLs and myelin integrity during brain aging. Inactivation of autophagy in oligodendrocyte lineage cells increases the number of OPCs/OLs in the developing brain while exaggerating the loss of OPCs/OLs with brain aging. Inactivation of autophagy in oligodendrocyte lineage cells impairs the turnover of myelin basic protein (MBP). It causes MBP to accumulate in the cytoplasm as multimeric aggregates and fails to be incorporated into integral myelin, which is associated with attenuated endocytic recycling. Inactivation of autophagy in oligodendrocyte lineage cells impairs myelin integrity and causes demyelination. Thus, this study shows autophagy is required to maintain myelin quality during aging by controlling the turnover of myelin components.
Animals ; Autophagy/physiology* ; Oligodendroglia/metabolism* ; Myelin Sheath/physiology* ; Aging/pathology* ; Myelin Basic Protein/metabolism* ; Cell Lineage/physiology* ; Mice ; Oligodendrocyte Precursor Cells ; Mice, Inbred C57BL ; Brain/cytology* ; Cells, Cultured ; Cell Count