The MORC2 p.S87L mutation reduces proliferation of pluripotent stem cells derived from a patient with the spinal muscular atrophy-like phenotype by inhibiting proliferation-related signaling pathways

Mutations in the microrchidia CW-type zinc finger protein 2(MORC2)gene are the causative agent of Charcot-Marie-Tooth disease type 2Z(CMT2Z),and the hotspot mutation p.S87L is associated with a more seve re spinal muscular atrophy-like clinical phenotype.The aims of this study were to determine the mechanism of the severe phenotype caused by the MORC2 p.S87L mutation and to explore potential treatment strategies.Epithelial cells were isolated from urine samples from a spinal muscular atrophy(SMA)-like patient[MORC2 p.S87L),a CMT2Z patient[MORC2 p.Q400R),and a healthy control and induced to generate pluripotent stem cells,which were then differentiated into motor neuron precursor cells.Next-generation RNA sequencing followed by KEGG pathway enrichment analysis revealed that differentially expressed genes involved in the PI3K/Akt and MAP K/ERK signaling pathways were enriched in the p.S87L SMA-like patient group and were significantly downregulated in induced pluripotent stem cells.Reduced proliferation was observed in the induced pluripotent stem cells and motor neuron precursor cells derived from the p.S87L SMA-like patient group compared with the CMT2Z patient group and the healthy control.G0/G1 phase cell cycle arrest was observed in induced pluripotent stem cells derived from the p.S87L SMA-like patient.MORC2 p.S87Lspecific antisense oligonucleotides(p.S87L-ASO-targeting)showed significant efficacy in improving cell prolife ration and activating the PI3K/Akt and MAP K/ERK pathways in induced pluripotent stem cells.Howeve r,p.S87L-ASO-ta rgeting did not rescue prolife ration of motor neuron precursor cells.These findings suggest that downregulation of the PI3K/Akt and MAP K/ERK signaling pathways leading to reduced cell proliferation and G0/G1 phase cell cycle arrest in induced pluripotent stem cells might be the underlying mechanism of the severe p.S87L SMA-like phenotype.p.S87L-ASO-targeting treatment can alleviate disordered cell proliferation in the early stage of pluripotent stem cell induction.

Association between baseline levels of muscular strength and risk of stroke in later life:The Cooper Center Longitudinal Study

Background:Muscular strength is an important component of physical fitness.We evaluated the relationship between baseline muscular strength and risk of stroke among adults who were aged≥65 years during follow-up.Methods:We included 7627 healthy adults(mean age=43.9 years,86.0%male)underwent a baseline physical examination between 1980 and 1989.Muscular strength was determined by 1-repetition maximum measures for bench press and leg press and categorized into age-and sex-specific tertiles for each measure.Cardiorespiratory fitness(CRF)was assessed via a maximal treadmill exercise test.Those enrolled in fee-for-service Medicare from 1999 to 2019 were included in the analyses.Associations between baseline strength and stroke outcomes were estimated using a modified Cox proportional hazards model.In a secondary analysis,we examined stroke risk by categories of CRF where Quintile 1=low,Quintiles 2-3=moderate,and Quintiles 4-5=high CRF based on age and sex.Results:After 70,072 person-years of Medicare follow-up,there were 1211 earliest indications of incident stroke.In multivariable analyses,the hazard ratio(95%confidence interval(95%CI))for stroke across bench press categories were 1.0(referent),0.96(0.83-1.11),and 0.89(0.77-1.04),respectively(p trend=0.14).The trend across categories of leg press was also non-significant(p trend=0.79).Adjusted hazard ratio(95%CI)for stroke across ordered CRF categories were 1.0(referent),0.90(0.71-1.13),and 0.72(0.57-0.92)(p trend<0.01).Conclusion:While meeting public health guidelines for muscular strengthening activities is likely to improve muscular strength as well as many health outcomes in older adults,performing such activities may not be helpful in preventing stroke.Conversely,meeting guidelines for aerobic activity is likely to improve CRF and lower stroke risk.

Mitochondria replacement from transplanted amniotic fluid stem cells:a promising therapy for non-neuronal defects in spinal muscular atrophy

Spinal muscular atrophy(SMA)is a genetic disorder that primarily affects infants and leads to muscle weakness,atrophy,and paralysis.The main cause is the homozygous mutation or deletion of the SMN1 gene,resulting in inadequate levels of the survival motor neuron(SMN)protein.Approved treatments focus on restoring SMN levels through various approaches,but there is a need for“SMN-independent”therapies that target other pathological processes.Skeletal muscle is closely involved in SMA pathology,with impaired muscle function observed before motor neuron degeneration.Studies have revealed that SMN loss leads to skeletal muscle mitochondrial structural abnormalities,impaired respiration,and accumulation of reactive oxygen species.

Insights into spinal muscular atrophy from molecular biomarkers

Spinal muscular atrophy is a devastating motor neuron disease characterized by severe cases of fatal muscle weakness.It is one of the most common genetic causes of mortality among infants aged less than 2 years.Biomarker research is currently receiving more attention,and new candidate biomarkers are constantly being discovered.This review initially discusses the evaluation methods commonly used in clinical practice while briefly outlining their respective pros and cons.We also describe recent advancements in research and the clinical significance of molecular biomarkers for spinal muscular atrophy,which are classified as either specific or non-specific biomarkers.This review provides new insights into the pathogenesis of spinal muscular atrophy,the mechanism of biomarkers in response to drug-modified therapies,the selection of biomarker candidates,and would promote the development of future research.Furthermore,the successful utilization of biomarkers may facilitate the implementation of gene-targeting treatments for patients with spinal muscular atrophy.

Reduced mesencephalic astrocyte-derived neurotrophic factor expression by mutant androgen receptor contributes to neurodegeneration in a model of spinal and bulbar muscular atrophy pathology

Spinal and bulbar muscular atrophy is a neurodegenerative disease caused by extended CAG trinucleotide repeats in the androgen receptor gene,which encodes a ligand-dependent transcription facto r.The mutant androgen receptor protein,characterized by polyglutamine expansion,is prone to misfolding and forms aggregates in both the nucleus and cytoplasm in the brain in spinal and bulbar muscular atrophy patients.These aggregates alter protein-protein interactions and compromise transcriptional activity.In this study,we reported that in both cultured N2a cells and mouse brain,mutant androgen receptor with polyglutamine expansion causes reduced expression of mesencephalic astrocyte-de rived neurotrophic factor.Overexpressio n of mesencephalic astrocyte-derived neurotrophic factor amelio rated the neurotoxicity of mutant androgen receptor through the inhibition of mutant androgen receptor aggregation.Conversely.knocking down endogenous mesencephalic astrocyte-derived neurotrophic factor in the mouse brain exacerbated neuronal damage and mutant androgen receptor aggregation.Our findings suggest that inhibition of mesencephalic astrocyte-derived neurotrophic factor expression by mutant androgen receptor is a potential mechanism underlying neurodegeneration in spinal and bulbar muscular atrophy.

Infantile Spinal Muscular Atrophy at the Albert Royer National Children’s Hospital Center in Dakar

Introduction: Infantile spinal muscular atrophy (ISA) is an autosomal recessive disease caused by primary degeneration of cells in the anterior horn of the spinal cord, leading to muscle weakness and hypotonia. Its incidence is estimated at 1 in 6000 births worldwide. In Africa, particularly in Senegal, there are few studies interested on this pathology. We therefore deemed this study necessary, which set itself the objective of describing the diagnostic, therapeutic and progressive aspects of infantile spinal muscular atrophy at the Albert Royer National Children’s Hospital Center in Dakar (CHNEAR). Methodology: We conducted a retrospective descriptive study over a period of two (2) years from December 2020 to December 2022. Included were all hospitalized patients in whom the diagnosis of spinal muscular atrophy was made with or without genetic confirmation. The data were collected on a pre-established form then entered and analyzed with the following software: Excel 2013 and R version 4.1.3. Results: During our study period, 2100 children were hospitalized, the annual incidence was 0.76%. The average age of our patients was 9 ± 9 months with a range of 3 months to 32 months and the median was 6.5 months. The sex ratio was 7. The notion of family consanguinity was found in 62.5% of cases and the notion of ISA in the family in 25% of cases. Hypotonia and respiratory distress were found at the forefront in equal proportions (50% of cases). Electromyogram (EMG) was performed in 3 patients (37.5%). Symptomatic medical treatment was administered in 100% of patients, 04 patients had benefited from respiratory physiotherapy, i.e. 50% of cases, and genetic counseling was carried out in one patient (12.5%). The evolution was immediately favorable in 2 patients or 25% of cases, unfavorable in 75% of cases with a death rate of 50% and the average age of death was 5.5 months ± 1 with extremes ranging from 3 to 7 months. Conclusion: The number of Infantile spinal muscular atrophy cases remains low in hospitals in Dakar. Diagnostic means are still difficult to access. The course is difficult to predict and is often marked in the long term by respiratory difficulties which can be fatal.

Anesthetic Management of a Patient with Spinal Muscular Atrophy Type III Undergoing Emergent Caesarean Section: A Case Report

In this case report, we describe the anesthetic management for a 36-year-old G2P0010 at 36 weeks gestation with Spinal Muscular Atrophy Type III who underwent an emergent caesarean section due to fetal footling breech position. The patient is a wheelchair-bound quadriplegic with kyphoscoliosis and a lack of cough reflex who required nasal continuous noninvasive ventilatory support (CNVS) for chronic hypercapnic respiratory failure. Surgery was done under general anesthesia due to its emergent nature, and the patient was successfully extubated and transitioned to nasal CNVS in the operating room at the end of the case. Postoperative care was provided in the medical intensive care unit for three days without complication and the patient was discharged home uneventfully.

Clinical Outcome of Internal Fixation and Fusion in the Treatment of Spinal Fractures by Paraspinal Muscular Space Approach

Objective:To explore the clinical effect of internal fixation and fusion with the paraspinal muscle gap approach in the treatment of spinal fracture patients.Methods:104 spinal fracture patients admitted to Central Hospital of TCM from October 2022 to April 2024 were selected as the study subjects and were randomly divided into the control group(n=52)and the observation group(n=52)according to the random number table method.The control group was treated with the conventional approach of internal fixation surgery,and the observation group was treated with the paraspinal muscular interspace approach of internal fixation fusion.The two groups’general data,surgical indexes,pain,lumbar spine function,and postoperative complications were observed.Results:The baseline data of the two groups of patients were not statistically significant(all P>0.05)while the intraoperative bleeding,the first postoperative time getting up from bed,and the length of hospital stay of the patients in the observation group were shorter than that of the control group(all P=0.000<0.001),and the duration of the operation was longer than that of the control group(t=2.644,P=0.010<0.05);at 3 months postoperatively,the VAS scores of the patients in the observation group were significantly lower than those in the control group(t=10.768,P=0.000<0.001),and the JOA score was higher than that of the control group(t=6.498,P=0.000<0.001);the total complication rate of patients in the observation group(3/5.77%)was significantly lower than that of the control group(12/23.08%)(χ^(2)=6.310,P=0.012<0.05).Conclusion:In the treatment of spinal fracture patients,compared with the conventional approach to internal fixation surgery,the paraspinal muscular gap approach to internal fixation and fusion treatment is less traumatic,postoperative lumbar spine function recovery is faster,and can reduce the incidence of postoperative complications.

The resistive range of motion exercise training in Duchenne muscular dystrophy:a case study

Background:To determine the effectiveness of resistive range of motion exercises in improving muscle strength and functional abilities in Duchenne muscular dystrophy.The study was also aimed to determine if resistive range of motion exercises can slow down the progression of the disease.Methods:A seven-year-old male child was diagnosed with Duchenne muscle dystrophy presented to outpatient physiotherapy clinic.The patient was presented with difficulty in stair climbing,sitting up from the floor,fatigue,and muscle weakness specifically weakness in the proximal limb muscles.The progressive resistive range of motion training was implemented for four years to improve muscle strength and functional abilities.The medical research council grading scale,north ambulatory assessment scale,and creatine kinase were used to evaluate muscle strength,functional abilities,and creatine kinase levels.Results:The muscular strength and functional abilities did not improve after four years of exercise training.The creatine kinase levels were decreased over the period of four years.Conclusion:Resistive range of motion exercises are helpful in maintaining the muscular strength and functional abilities in Duchenne muscular dystrophy.

Optimal resection of gastric bronchogenic cysts based on anatomical continuity with adherent gastric muscular layer: A case report

BACKGROUND Bronchogenic cysts are congenital lesions requiring radical resection because of malignant potential.However,a method for the optimal resection of these cysts has not been completely elucidated.CASE SUMMARY Herein,we presented three patients with bronchogenic cysts that were located adjacent to the gastric wall and resected laparoscopically.The cysts were detected incidentally with no symptoms and the preoperative diagnosis was challenging to obtain via radiological examinations.Based on laparoscopic findings,the cyst was attached firmly to the gastric wall and the boundary between the gastric and cyst walls was difficult to identify.Consequently,resection of cysts alone caused cystic wall injury in Patient 1.Meanwhile,the cyst was resected completely along with a part of the gastric wall in Patient 2.Histopathological examination revealed the final diagnosis of bronchogenic cyst and revealed that the cyst wall shared the muscular layer with the gastric wall in Patients 1 and 2.In Patient 3,the cyst was located adjacent to the gastric wall but histopathologically originated from diaphragm rather than stomach.All the patients were free from recurrence.CONCLUSION The findings of this study state that a safe and complete resection of bronchogenic cysts required the adherent gastric muscular layer or full-thickness dissection,if bronchogenic cysts are suspected via pre-and/or intraoperative findings.

Surgical and long-term functional outcomes of patients with Duchenne muscular dystrophy following spinal deformity correction

BACKGROUND Life expectancy in patients with Duchenne muscular dystrophy(DMD)has improved due to advances in medical care.DMD patients develop progressive spinal deformity after loss of ambulatory function and onset of wheelchair dependence for mobility.There is limited published data on the effect of spinal deformity correction on long-term functional outcomes,quality of life(QoL),and satisfaction in DMD patients.AIM To investigate the long-term functional outcomes following spinal deformity correction in DMD patients.METHODS This was a retrospective cohort study from 2000-2022.Data was collected from hospital records and radiographs.At follow-up,patients completed the muscular dystrophy spine questionnaire(MDSQ).Statistical analysis was performed by linear regression analysis and ANOVA to analyse clinical and radiographic factors significantly associated with MDSQ scores.RESULTS Forty-three patients were included with mean age 14.4 years at surgery.Spinopelvic fusion was performed in 41.9%of patients.Mean surgical time was 352.1 min and mean blood loss was 36%of estimated total blood volume.Mean hospital stay was 14.1 d.Postoperative complications occurred in 25.6%of patients.Mean preoperative scoliosis was 58°,pelvic obliquity 16.4°,thoracic kyphosis 55.8°,lumbar lordosis 11.1°,coronal balance 3.8 cm,and sagittal balance+6.1 cm.Mean surgical correction of scoliosis was 79.2%and of pelvic obliquity was 80.8%.Mean follow-up was 10.9 years(range:2-22.5).Twenty-four patients had died at follow-up.Sixteen patients completed the MDSQ at mean age 25.4 years(range 15.2-37.3).Two patients were bed-ridden and 7 were on ventilatory support.Mean MDSQ total score was 38.1.All 16 patients were satisfied with the results of spinal surgery and would choose surgery again if offered.Most patients(87.5%)reported no severe back pain at follow-up.Factors significantly associated with functional outcomes(MDSQ total score)included greater duration of post-operative follow-up,age,scoliosis postoperatively,correction of scoliosis,increased lumbar lordosis postoperatively,and greater age at loss of independent ambulation.CONCLUSION Spinal deformity correction in DMD patients leads to positive long-term effects on QoL and high patient satisfaction.These results support spinal deformity correction to improve long-term QoL in DMD patients.

Stem cell transplantation for treating Duchenne muscular dystrophy A Web of Science-based literature analysis

OBJECTIVE： To identify global research trends in stem cell transplantation for treating Duchenne muscular dystrophy using a bibliometric analysis of Web of Science. DATA RETRIEVAL： We performed a bibliometric analysis of studies on stem cell transplantation for treating Duchenne muscular dystrophy from 2002 to 2011 retrieved from Web of Science. SELECTION CRITERIA： Inclusion criteria： （a） peer-reviewed published articles on stem cell transplantation for treating Duchenne muscular dystrophy indexed in Web of Science; （b） original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material, and news items; and （c） publication between 2002 and 2011. Exclusion criteria： （a） articles that required manual searching or telephone access; （b） documents that were not published in the public domain; and （c） corrected papers. MAIN OUTCOME MEASURES： （1）Annual publication output; （2） distribution according to subject areas; （3） distribution according to journals; （4） distribution according to country; （5） distribution according to institution; （6） distribution according to institution in China; （7） distribution according to institution that cooperated with Chinese institutions; （8） top-cited articles from 2002 to 2006; （9） top-cited articles from 2007 to 2011. RESULTS： A total of 318 publications on stem cell transplantation for treating Duchenne muscular dystrophy were retrieved from Web of Science from 2002 to 2011, of which almost half derived from American authors and institutes. The number of publications has gradually increased over the past 10 years. Most papers appeared in journals with a focus on gene and molecular research, such as Molecular Therapy, Neuromuscular Disorders, and PLoS One. The 10 most-cited papers from 2002 to 2006 were mostly about different kinds of stem cell transplantation for muscle regeneration, while the 10 most-cited papers from 2007 to 2011 were mostly about new techniques of stem cell transplantation for treating Duchenne muscular dystrophy. CONCLUSION： The publications on stem cell transplantation for treating Duchenne muscular dystrophy were relatively few. It also needs more research to confirm that stem cell therapy is a reliable treatment for Duchenne muscular dystrophy.

Effects of Different Rearing Modes on the Muscular Histological Traits and Meat Tenderness of Chicken

[ Objective] The aim of this experiment was to explore the effects of different rearing modes on muscle histological traits and muscle ten demess and to provide theoretical basis for regulating chicken meat quality. [ Method] The effects of outdoor rearing, indoor rearing and cage rea ring modes on the muscular histological traits and meat tenderness of Hetian chicken at the age of 8 weeks, 12 weeks and 16 weeks were re searched. [Result] The results showed that the breast and thigh muscle fibre diameter and muscle shear force of outdoor rearing chicken were sig nificently higher than that of cage rearing chicken （ P 〈 0.05）, and muscle fibre density was significantly lower than that of cage rearing chicken （ P 〈 0.05）. With aging, the muscle fibre diameter and shear force increased and muscle fibre density decreased （ P 〈 0.05）. The muscle fibre di ameter and shear force of male were higher than that of female. The correlation analysis showed that the breast muscle shear force had a signifi cantly positive relation with fibre diameter and negative relation with fibre density （ P 〈 0.05）, but thigh muscle shear force had an insignificantly pos itive relation with fibre diameter and fibre density. [ Condusion] Muscular histological traits varied in different rearing modes, and the outdoor rearing promoted the muscular fibre development and increased the muscular shear force.

Characteristics of Deposition of Inosine Monophosphate(IMP) and Intramuscular Fat(IMF) in Muscles of Jinghai Yellow Chicken and Its Crossbreeds

[Objective] This study aimed to investigate the characteristics of deposition of inosine monophosphate （IMP） and intramuscular fat （IMF） in muscles of Jinghai yellow chickens and its crossbred.[Method] The characteristics of IMP and IMF deposition of 112-day-old Jinghai yellow chickens （J×J） and its two different 70-day- old crossbreeds （J×B and B×B） were analyzed. The IMP content in breast muscle and leg muscle were determined by HPLC. [Result] The contents of IMP and cor- rected inosine monophosphate （IMPc） in breast muscle were significantly or ex- tremely significantly higher than that in leg muscle of the chickens in the three groups whether in male or female chickens （P〈0.05 or P〈0.01）. There were no sig- nificant difference in the contents of IMP and IMPc between hens and roosters （P〉 0.05）. The fresh degree of breast muscle and leg muscle was 96,11%-98.16% and 87.22%-93.07%, respectively. And the fresh degree of breast muscle was higher than that of leg muscle. In the three groups, the IMF content in leg muscle was significantly higher than that in breast muscle whether in male or female chickens （P〈0.05）. The contents of IMF in breast muscle and leg muscle were 0.36%-0.75% and 1.84%-2.38%, respectively. The iMP content in breast muscle of chickens in Bx J group was extremely significantly higher than that in breast muscle of chickens in JxJ group （P〈0.01）, but the contents of IMPc and iMF of breast muscle and leg muscle of the chickens in the three groups had no significant difference （P〉0.05）. [Conclusion] To sum up, the freshness and flavor significantly differ between the breast muscle and leg muscle of chickens, but show no significant difference among the three groups.

Muscular Histological Traits and Meat Tenderness of Different Local Broilers

Objective＇ To study the muscular histological traits and their relationship with meat tenderness in local broilers and provide a theoretical basis for promoting meat quality of broiler. [Methed] The diameter and density of muscle fiber of three local varieties of chicken （Beijing Fatty broil- er, Fujian Hetian broiler and Taining Black broiler） were detected at the age of 8 weeks, 12 weeks and 16 weeks. And the differences in the diame- ter and density of muscle fiber as well as their relationship with meat tenderness were respectively analyzed with SAS software. [ Resultl Fatty broil- er had the smallest muscle fiber diameter while Hetian broiler the largest; Fatty broiler had the highest muscle fiber density while Hetian broiler the lowest Hetian broiler had the highest muscle shear force of leg muscle while Black broiler the lowest （ P 〈0.05） ; Black broiler had the highest mus- cle shear force of breast muscle while Fatty broiler the lowest （P〈0.05）. The correlation analysis showed that the shear force of breast muscle and leg muscle had significantly positive relation with fiber diameter and significantly negative relation with fiber density （ P 〈 0.05）. [ Conclusion] Muscu- lar histological traits varied in different local broilers, and the muscular shear force had significantly relation with fiber diameter and density.

Umbilical cord mesenchymal stem cell transplantation for the treatment of Duchenne muscular dystrophy

Due to their relative abundance,stable biological properties and excellent reproductive activity,umbilical cord mesenchymal stem cells have previously been utilized for the treatment of Duchenne muscular dystrophy,which is a muscular atrophy disease.Three patients who were clinically and pathologically diagnosed with Duchenne muscular dystrophy were transplanted with umbilical cord mesenchymal stem cells by intravenous infusion,in combination with multi-point intramuscular injection.They were followed up for 12 months after cell transplantation.Results showed that clinical symptoms significantly improved,daily living activity and muscle strength were enhanced,the sero-enzyme,electromyogram,and MRI scans showed improvement,and dystrophin was expressed in the muscle cell membrane.Hematoxylin-eosin staining of a muscle biopsy revealed that muscle fibers were well arranged,fibrous degeneration was alleviated,and fat infiltration was improved.These pieces of evidence suggest that umbilical cord mesenchymal stem cell transplantation can be considered as a new regimen for Duchenne muscular dystrophy.

Abnormal layering of muscularis propria as a cause of chronic intestinal pseudo-obstruction:A case report and literature review

Visceral myopathy is one of the causes of chronic intestinal pseudo-obstruction. Most cases pathologically reveal degenerative changes of myocytes or muscularis propia atrophy and fibrosis. Abnormal layering of muscularis propria is extremely rare. We report a case of a 9-mo-old Thai male baby who presented with chronic intestinal pseudo-obstruction. Histologic findings showed abnormal layering of small intestinal muscularis propria with an additional oblique layer and aberrant muscularization in serosa. The patient also had a short small bowel without malrotation, brachydactyly,and absence of the 2nd to 4th middle phalanges of both hands. The patient was treated with cisapride and combined parenteral and enteral nutritional support.He had gradual clinical improvement and gained body weight. Subsequently, the parenteral nutrition was discontinued. The previously reported cases are reviewed and discussed.

Emerging concepts underlying selective neuromuscular dysfunction in infantile-onset spinal muscular atrophy

Infantile-onset spinal muscular atrophy is the quintessential example of a disorder characterized by a predominantly neurodegenerative phenotype that nevertheless stems from perturbations in a housekeeping protein.Resulting from low levels of the Survival of Motor Neuron(SMN)protein,spinal muscular atrophy manifests mainly as a lower motor neuron disease.Why this is so and whether other cell types contribute to the classic spinal muscular atrophy phenotype continue to be the subject of intense investigation and are only now gaining appreciation.Yet,what is emerging is sometimes as puzzling as it is instructive,arguing for a careful re-examination of recent study outcomes,raising questions about established dogma in the field and making the case for a greater focus on milder spinal muscular atrophy models as tools to identify key mechanisms driving selective neuromuscular dysfunction in the disease.This review examines the evidence for novel molecular and cellular mechanisms that have recently been implicated in spinal muscular atrophy,highlights breakthroughs,points out caveats and poses questions that ought to serve as the basis of new investigations to better understand and treat this and other more common neurodegenerative disorders.

Segmental arterial mediolysis: A clinical-pathologic review, its role in fibromuscular dysplasia and description and differential diagnosis of the masquerader-muscular artery cystic necrosis

Segmental arterial mediolysis (SAM) is an uncommon non-inflammatory iatrogenic arteriopathy caused by alpha-1 adrenergic agonists or Beta-2 agonists able to release norepinephrine from the peripheral nervous system. Causative agents include adrenergic agonists used to control blood pressure, B-2 tocolytic agonists, and ractopamine used as a repartitioning agent in animal husbandry. The liberated norepinephrine both injures and stimulates a robust reparative response in the muscular arteries in the abdomen, brain base, and coronary arteries. This response may be augmented by endothelin-1 formed in the arterial adventitia. Three types of arterial lesions develop in the injurious stage: 1) apoptotic induced mediolysis, 2) separation of the outer media from the adventitia and 3) the formation of arterial gaps. The latter enlarge, particularly in elderly patients, to form gap-aneurysms complicated by dissections and dissecting an- eurysms that when ruptured cause the calamitous hemorrhages that clinically announce SAM. The other types of injury remain clinically silent but with repair develop sequelae and can metamorphose into fibromuscular dysplasia. The sequelae are mainly asymptomatic but may cause arterial stenosis and ischemic lesions. The definitive diagnosis of SAM re- quires histological conformation but misinterpreta- tion of smooth muscle vacuolar change has caused di- agnostic errors. Muscular artery cystic necrosis a newly named non-inflammatory muscular artery ar- teriopathy may be confused with SAM both clinically and pathologically. This arteriopathy represents the muscular artery equivalent of cystic media necrosis of the elastic arteries since it exhibits similar morphol- ogic features and can occur concomitantly with this entity. Adrenergic agents to counter hemorrhagic shock in SAM are contraindicated since they may intensify injury and create new lesions. The use of norepinehrine antagonists introduces a new, but as yet untested, treatment option for SAM.

优化多重PCR检测Duchenne muscular dystrophy基因外显

目的:介绍一种快速简便地优化多重PCR检测DMD基因外显子缺失的方法及详细步骤.方法:采2ml外周血,用0.2%氯化钠处理收集白细胞,再用基因组DNA提取试剂盒抽提基因组DNA,用优化的多重PCR法直接检测DMD基因外显子的缺失.结果:用该方法检测DMD基因外显子缺失结果准确清晰.结论:用优化的多重PCR技术可以直接检测DMD基因外显子缺失,跟通常使用的9对引物一步法相比,具有经济、快速、简便等特点.