ABSTRACT
Randomized placebo-controlled trials are the primary means of evaluating the effectiveness of treatments. Patients experience symptom relief or adverse effects after taking placebo, which is called placebo effects or nocebo effects. The placebo and nocebo effects are particularly common in headache and have an important impact on the results of clinical trials, so it is important to understand its mechanism and influencing factors. This review describes the mechanism, clinical manifestations and risk factors of placebo and nocebo effects in headache treatment, and discusses how to avoid the placebo and nocebo effects on clinical treatment.
ABSTRACT
Objective@#To explore the association among clinical features, electromyography (EMG) and magnetic resonance neurography (MRN) in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). @*Methods@#A cross-sectional survey was conducted to enroll consecutively typical CIDP patients in Renmin Hospital of Wuhan University from May 2017 to May 2019. The Hughes Disability Scale (HDS) was used to evaluate the illness severity of the patients. The electrodiagnostic parameters including motor conduction velocity (MCV), compound muscle action potential (CMAP), F-wave latency, sensory nerve conduction velocity (SCV) and sensory nerve action potential (SNAP) of upper and lower limbs were analyzed. The patients whose response waveform can be elicited in all nerves were defined as group A, and those without response in one or more nerves as group B. MRN quantitative technique was used to calculate the cross-sectional area of nerves roots (nr-CSA) of brachial plexus and lumbosacral plexus. The linear regression method was used to analyze the correlation among clinical features, EMG and nr-CSA. @*Results@#A total of 32 patients with typical CIDP met the criteria, 75% (24/32) of whom were males. There were 16 patients in the mild group (group A) and 16 in the severe one (group B). The abnormal rate of F-wave latency was the highest. Cerebrospinal fluid (CSF) protein, HDS score were correlated significantly with the nr-CSA of brachial plexus and lumbosacral plexus in the two groups (group A: CSF protein and brachial plexus nr-CSA: r=0.498, P=0.004; CSF protein and lumbosacral plexus nr-CSA: r=0.479, P=0.007; HDS score and brachial plexus nr-CSA: r=0.650, P=0.000; HDS score and lumbosacral plexus nr-CSA: r=0.625, P=0.000. group B: CSF protein and brachial plexus nr-CSA: r=0.497, P=0.049; CSF protein and lumbosacral plexus nr-CSA: r=0.503, P=0.047; HDS score and brachial plexus nr-CSA: r=0.605, P=0.001; HDS score and lumbosacral plexus nr-CSA: r=0.648, P=0.000). MCV of median nerve and ulnar nerve was negatively correlated with nr-CSA of brachial plexus in the two groups (group A: MCV of median nerve and nr-CSA of brachial plexus: r=-0.309, P=0.019; MCV of ulnar nerve and nr-CSA of brachial plexus: r=-0.286, P=0.027. group B: MCV of median nerve and nr-CSA of brachial plexus: r=-0.660, P=0.000; MCV of ulnar nerve and nr-CSA of brachial plexus: r=-0.581, P=0.001). The F-wave latencies of median and ulnar nerves were positively correlated with nr-CSA of brachial plexus, and the CMAP amplitude of tibial nerve and SNAP amplitude of sural nerve were positively correlated with nr-CSA of lumbosacral plexus in group B. @*Conclusions@#Male patients with CIDP are predominant. The higher the nr-CSA in brachial plexus and lumbosacral plexus, the higher the CSF protein and disability score, and the larger the nr-CSA in brachial plexus, the slower the MCV in the median and ulnar nerve. For group B patients with more severe nerve injury, the larger nr-CSA of brachial plexus was, the longer F-wave latency of median and ulnar nerve was, and the larger nr-CSA of lumbosacral plexus was, the lower CMAP amplitude of tibial nerve and SNAP amplitude of sural nerve were. As a non-invasive test, MRN can be used to assist in the diagnosis of CIDP and to assess the severity of the disease.
ABSTRACT
Objective To analyze the clinical features and validation of Brighton criteria in Guillain-Barré syndrome (GBS) patients from southern China.Methods The clinical data of hospitalized GBS patients from 69 hospitals of 14 provinces/cities in southern China,the area south of the Huaihe River,between 1 January 2013 and 30 September 2016,were collected and analyzed retrospectively,and patients were classified according to the Brighton criteria of case definition,ranging from a highest (defined as level one) to a lowest (level four) level of diagnostic certainty.Results A total of 1 358 GBS patients were collected,including 51 cases with cranial nerve variants,157 with Miler-Fisher syndrome and 1 150 with classic GBS characterized by flaccid weakness of limbs.Among 1 150 cases of classic GBS,49.57％ (570/1 150) patients had antecedent events,with respiratory infection predominated (71.23％,406/570);83.74％ (963/1 150) presented limb weakness at onset,99.21％ (1 124/1 133) reached the peak within four weeks,with a score of 3.15 ± 1.16 for Hughes Disability Scale;99.56％ (1 128/1 133)developed bilateral weakness and 95.39％ (1 097/1 150) manifested flexia or hyporeflexia;the cerebrospinal fluid showed albuminocytologic dissociation in 80.58％ (772/958) patients whose lumbar puncture was performed;demyelinating GBS accounted for 48.14％ (401/833) and axonal subtype 18.01％ (150/833) respectively in patients with findings of nerve conduction studies available.According to Brighton criteria,the patients were stratified as level one in 44.09％ (507/1 150),level two in 45.74％ (526/1 150),level three in 7.57％ (87/1 150) and level four in 2.61％ (30/1 150) of all the patients,and 69.55％ (507/729),28.67％ (209/729),0％ (0/729) and 1.78％ (13/729),respectively in the patients with complete data (n =729).Conclusions In southern China,demyelinating subtype of GBS is predominant,whereas the proportion of axonal subtype is remarkably lower than that in northern China.The Brighton criteria have a high sensitivity for the diagnosis of GBS in southern China,and examination of cerebrospinal fluid and electrodiagnostic studies are necessary for stratified diagnosis.
ABSTRACT
Objective To investigate the changes of immune function and blood coagulation function in pa-tients with pulmonary tuberculosis(PTB)with chronic obstructive pulmonary disease(COPD)and its correla-tion with lung function.Methods 65 cases of PTB patients with COPD were selected as PTB with COPD group,50 cases of patients with PTB were selected as PTB group,another 50 healthy people were selected as control group;the level of immune function and coagulation function were compared between the three groups,and the relationship between immune function,coagulation function and pulmonary function was ana-lyzed.Results The differences of CD3+,CD4+,CD4+/CD8+,TT,APTT,PT,FIB,FEV1,FVC and MMEF between the three groups were statistically significant(P<0.05);The levels of CD3+,CD4+,CD4+/CD8+, APTT,FEV1,FVC and MMEF in PTB group and PTB group with COPD were significantly lower than those in control group,and PTB group with COPD group was significantly lower than that in PTB group,the differ-ence was statistically significant(P<0.05);The levels of TT and FIB in PTB group and PTB group with COPD were significantly higher than those in control group,and PTB group with COPD group was significant-ly higher than that in PTB group,the difference was statistically significant(P<0.05);The results of corre-lation analysis showed that FEV1,FVC and MMEF had significant positive correlation with CD3+,CD4+, CD4+/CD8+,APTT and PT(P<0.05),and negatively correlated with TT and FIB(P<0.05),and there was no significant correlation between FEV1,FVC,MMEF and CD8+(P>0.05).Conclusion The patients with PTB accompanied with COPD have abnormal cellular immune function and abnormal coagulation func-tion,and the level is significantly correlated with lung function.
ABSTRACT
Objective To study the photodynamic therapeutical efficacy of a novel photosensitizer DTP on sensitive gastric cancer cells (SGC7901) and vincristine-resistant gastric cancer cells (SGC7901/VCR).Methods The P-gp expression on the SGC7901 and SGC7901/VCR cell membrane was indirectly confirmed by fluorescence microscopy.The survival rates of SGC7901 and SGC7901/VCR cells were evaluated by cell counting kit (CCK-8) after photodynamic therapy with DTP.The intracellular DTP uptake levels of two types of cell were determined using a fluorescence spectrophotometer,and the intracellular DTP distributions were observed by laser scanning confocal microscopy.Results The novel photosensitizer DTP has considerable photodynamic cytotoxic effect on SGC7901 and SGC7901/VCR cells.However,this effect on the SGC7901NCR cells was relatively weak (P＜0.05),and could not be enhanced by P-gp inhibitor verapamil or cyclosporine A(P＞0.05).The DTP uptake level in SGC7901 cells was higher than that in SGC7901/VCR cells (P＜0.05),and could not be enhanced by P-gp inhibitor verapamil and cyclosporin A (P＞0.05).It was found that DTP distributed in the lysosomes of SGC7901 cells and in the lysosomes and mitochondria of SGC7901/VCR cells.Conclusions The novel photosensitizer DTP is not the substrate of multidrug transporter P-gp,and its weaker photodynamic cytotoxic effect on SGC7901/VCR cells is independent of the P-gp overexpression on its cell membrane,which may be related to the distribution of intracellular DTP in the two types of cell.
ABSTRACT
Objective To explore the effect of health education on medication compliance of middle-aged and elderly hypertensive patients in rural areas. Methods Outpatients aged 45 hypertensive patients were divided into two groups, the intervention group was given health education knowledge, intervention of bad habits and knowledge of drug by oral presentations, banner ads, TV screen publicity, publicity, newspaper, telephone follow-up and other forms of propaganda. Results Hypertension knowledge, dietary knowledge, living habits, medication knowledge, medication compliance of patients in the intervention group were increased significantly, and there were significant difference in the four survey in the observation group with statistical significance(P<0.05). Conclusion Health education has a great influence on drug compliance among middle-aged and elderly hypertensive patients in rural areas, and has great significance for controlling blood pressure.
ABSTRACT
BACKGROUND:Nanohydroxyapatite/polyamide 66 composite is very close to the human cortical bone in terms of mechanical properties, and has osteogenic activity, which is a safe and reliable bone material. OBJECTIVE:To investigate the effect of nanohydroxyapatite/polyamide 66 composite bioactive supporting material on the restoration of vertebral structure and height. METHODS: Totaly 177 patients with spinal diseases, 116 males and 61 females, aged 17-81 years, were enroled, including 97 cases of spinal fractures, 5 cases of primary tumors of the spine, 17 cases of spinal tuberculosis and 58 cases of cervical spondylosis. The nanohydroxyapatite/polyamide 66 composite bioactive supporting body was filed into the bone grafts of patients and then subjected to anterior decompression and internal fixation. After 36 months of folow-up, imaging analysis, Frankel spinal cord injury classification, bone graft fusion, visual analog scale scores,Short Form 36 and Japanese Orthopedic Association scores were evaluated. RESULTS AND CONCLUSION:During the folow-up, except one patient with cervical spine fracture appeared to have slight supporting body displacement, there was no supporting body prolapse or rupture phenomena. The bone graft fusion rate was 96.0%, the average supporting body sinking distance was 1.7 mm. After treatment, 97 patients with spinal fractures had different degree of improvement in the neurological function (P < 0.05); the visual analog scale scores, Short Form 36 and Japanese Orthopedic Association scores were improved significantly in al the 177 patients compared with before treatment (P < 0.05). These results demonstrate that the use of nanohydroxyapatite/polyamide 66 composite bioactive supporting material for spinal reconstruction can improve the bone fusion rate, and restore the vertebral structure and height effectively.
ABSTRACT
Objective:To establish the quality control method for Tribulus terrestris L. by colorimetry and HPLC. Methods:The HPLC method was with a Welch Ultimate LP-C18 column(250 mm × 4. 6 mm,5μm),the mobile phase was methanol-water(80:20) and the detection wavelength was 203 nm. The colorimetry was with a perchloric acid method. The saponins of Tribulus terrestrist as the index,the determination method for total saponins and saponins of Tribulus terrestris L. was established. Results:The results of the HPLC and colorimetry methods showed saponins of Tribulus terrestris had good linear relationship within the range of 0. 820-7. 380 μg and 24. 600-86. 100 μg with the average recovery of 99. 3% and 99. 5%,respectively. Total saponins and saponins of Tribulus terres-tris in Tribulus terrestris from 18 habitats were measured by the methods. Conclusion:The methods are sensitive,accurate and repro-ducible,and can be used as the quality control methods for Tribulus terrestris.
ABSTRACT
Objective To evaluate the medical indexes for student pilots from different areas , to discover the major different indexes between different areas ,and to establish the space distribution model of military pilots .Methods A cross-section survey was conducted among student pilots , and 290 student pilots sampled as respondents were interviewed with questionnaires and subjected to a physical examination , involving distant vision , heart function , and pulmonary function , before a database was established , cleaned and analyzed by EpiData 3.02, SAS 9.13 with double checking .Results There was no difference between the medical indexes of student pilots from 7 areas, but the psychological selection performance record and the entrance examination record were different .Student pilots from area E had the highest psychological selection performance record while those from area D had the highest entrance examination record .Conclusion Student pilots have area difference ,so we should pay close attention to their birth place during recruitment of student pilots .
ABSTRACT
Objective To improve the knowledge of primary gout in children. Methods Clinical data of a 12-year-old girl with primary gout was collected. Analysis of UMOD gene, REN gene and HNF-1βgene was performed using PCR and di-rect sequencing. Results The girl was admitted for 1-month history of left hallux pain accompanied with elevations of serum uric acid concentration and serum creatinine concentration. Several examinations showed serum uric acid/creatinine ratio was greater than 2.5. The fractional excretion of uric acid was 3.4%-6.6%. The X-ray showed that the proximal phalanxes of halluces were erosion. The diagnosis of renal biopsy was ischemic renal injury and chronic tubulointerstitial nephropathy. Blood uric acid concentrations of parents were normal, and the family history of gout was negative. Two single nucleotide polymorphisms (c.264C>T heterozygous and c.866-71 G>A heterozygous) in UMOD gene, 1 single nucleotide polymorphism (c.373+44C>G heterozygous) in REN gene, and 2 single nucleotide polymorphisms (c.100-50-49ins TCTG heterozygous and c.781-22T>C homozygous) in HNF-1βgene were detected. No pathological mutation was detected in these 3 genes. Conclusions This child is highly suspected to have primary gout caused by familial juvenile hyperuricemic nephropathy.
ABSTRACT
Objective To explore the inflnence of autologous peripheral blood hematopoietic stem cell transplantation (auto-HSCT) for lymphoma process on the quality of patients blood coagulation.Methods Plasma samples were collected before the conditioning and on day 0,7,14,28,35 follow auto-HSCT from 20 patients.The following parameters were measured:prothrombin time (PT),activated partial thromboplastin time (APTT),fibrinogen (FIB) and D-dimer(D-Di).Results Compared with the values before conditioning,a significant rise in the FIB values was detected on day 7 and day 14 after auto-HSCT,no essentially change in the FIB values was detected on day 21 and day 28 and day 35 after auto-HSCT.Other coagulation parameters investigated(PT.APTT.D-Di) remained essentially unchanged.All of the patients not concurrent thrombotic disease.Conclusion Lymphoma patients with autologous peripheral blood hematopoietic stem cell transplantation appear abnormality in coagulant function.Clinical doctors should concern.
ABSTRACT
Objective To investigate the pathological features of blood vessel inflammation in facioscapulohumeral muscular dystrophy ( FSHD ) and the role of vasculitis on the pathogenesis of FSHD. Methods The clinical manifestations and myopathological features of 26 FSHD patients were retrospectively analyzed and summarized. All of the patients were divided into 2 groups; inflammatory infiltration group and non-inflammatory infiltration group. The latter was further divided into 3 subgroups;endomysial inflammation subgroup, perivasculitis subgroup and transmural vasculitis subgroup.Immunohistochemical staining were carried out in inflammatory infiltration group with anti-CD3, anti-CD4,anti-CD8,anti-CD20 and anti-SMA antibody. The control group was composed of 10 dermatomyositis ( DM)cases and 10 polymyositis ( PM) cases. Results The age of onset was (25. 2 ± 12. 6) years old and the average course was (7. 8 ±7. 3) years. The sex ratio of male to female was 1.6: 1. Five of them had family history. The main clinical features were progressive weakness and atrophy of facial, shoulder girdles and proximal upper limbs muscles. The lower distal limbs and (or) lower distal limbs and pelvic girdle muscles were involved in 18 cases. The main pathological features were shown as followed. Seventeen of them had focal inflammatory cell infiltration, including endomysial inflammation (4/17) , perivasculitis (7/17) , and transmural vasculitis (6/17). Immunohistochemical staining confirmed the major types of inflammatory cells were CD4* T lymphocytes and CD20B lymphocytes, which was familiar with DM. While in PM, CD8+ T lymphocytes were dominant The proportionality of residual muscle fibers obviously decreased in inflammatory infiltration group ( 48. 0% ± 23. 6% ) than non-inflammatory infiltration group ( 94. 3% ±3. 1% , T = 198. 000, P = 0. 000). As to CK levels, there were no significant deviation. Conclusions Obvious inflammatory cell infiltration can be seen in FSHD, the locations of inflammatory cells are endomyosium inflammation, perivasculitis and transmural vasculitis. Transmural vasculitis indicates vascular pathological factor may have something to do with pathogenesis of FSHD.
ABSTRACT
Objective To study the histological features of plasmacytoid dendritic cells (pDC) in muscle tissue affected by dermatomyositis (DM) and to discuss the pathological significations of pDC.Methods Muscle tissues from 30 cases of DM and 25 cases of polymyositis (PM) were collected.HE stain, immunohistochemistry studies were carried out in all muscle samples.Results Pathological features of DM included: perifascicular atrophy (25/30); punched-out fiber (14/30); perivasculitis (17/30),inflammatory infiltration in the endomysium(6/30).Using immunohistochemistry study, 19 cases from DM were infiltrated by macrophages which are CD68 positive and CD303 negative, 20 cases with DM were infiltrated by pDC which are CD303 positive.The location of pDC were: perivascular of interfascicular septae only (15/20); endomysium only (3/20) and both (2/20).Myopathic damage such as necrotic and regenerating fibers and inflammatory infiltration could be seen in PM.There was few pDC infiltration in PM.Conclusions There is few pDC in muscle tissue affected by PM and many pDC in muscle tissue affected by DM with infiltration mainly in the wide interfascicular septae.pDC may be connected to perifascicular atrophy and play a roll in the pathogenesis of DM.
ABSTRACT
Objective To investigate the clinical and molecular pathological features of limb-girdle muscular dystrophy 2A (LGMD2A) of Chinese patients. Methods Thirty cases of LGMD with excluding LGMD2B were included in this study. The muscle specimens were performed by a standard series methods of histochemistry, enzymohistochemistry, immunohistochemistry and Western blot. The clinical and molecular pathological features of LGMD2A were retrospective analyzed. Results Five cases with no or only trace expression of calpain-3 protein were diagnosed as calpainopathy (LGMD2A) by Western blot analysis. The age of onset of these 5 patients ranged from 10 to 45 years and the duration of the disease were about 2-10 years. Proximal muscles weakness and atrophy of lower limbs were predominantly involved. In all patients,symptoms progressed slowly. The ambulation could be retained for many years but running and jumping were impaired early. The serum creatine kinase level was elevated moderately to markedly. Electromyography showed myopathic patterns in all cases. Two siblings had similar symptoms indicating autosomai recessive inherited pattern. Pathologically, there was marked variation in fibre size and most small fibres were round. Some necrotic and regenerating fibers were seen. Fibres with centrally placed nuclei can be found frequently. No infiltrations of inflammatory cells were seen. Lobulated fibers were observed in 2 patients by NADH-TR stain. The expression of dystrophin, caveolin-3, α-, β-, γ- and δ-sarcoglycan protein were normally staining of 5 LGMD2A patients' specimens by immunohistochemistry. Two patients had reduced staining of dysferlin by immunohistochemistry study. Conclusions Clinical and pathological characteristics of our 5 LGMD2A patients are consistent with typical muscular dystrophy features reported in other countries. Identification of calpian-3 deletion by Western blot is essential for the diagnosis of calpainopathy.
ABSTRACT
In view of the transformation from traditional biomedicine to biology-psychology-social medicine,the comprehensive medical iournals,in order to advance the development of the medicine,should pay attention to the articles on psychology,society and environment with diseases;strictly investigate the ethics in the articles;and publish the articles on the medical humanity promptly.
ABSTRACT
Objective To study the expression and significance of multidrug resistance gene (MDR1) in children with refractory epilepsy (RE). Methods Children with RE (n = 30), non-RE (n = 30) and healthy children (n=30) were collected. The expression of MDR1-mRNA in peripheral blood was analyzed by fluorescence quantitative PCR. The relationship of MDRI-mRNA with epileptic frequency and numbers of antiepileptic drugs (AEDs) were observed. Results The expression of MDR1 in RE group obviously increased when compared with that of non-RE group and healthy group (P < 0.01, P < 0.01) ; MDR1 expression was more among patients with high frequent epilepsy than patients with low frequent epilepsy (P < 0.01) ; more in patients administered with four kinds of AEDs than those with two or three kinds of AEDs (P < 0.01). Concinsions MDR1 overexpression in blood of children with RE may be linked to drug-resistant mechanism of RE. It might be used as a clinical indicator of RE.
ABSTRACT
Objective To study the clinical and pathological manifestations of microsporidian encephalitis.Methods The clinical findings and the brain pathological features of a patient with microsporidian encephalitis hospitalized in 2004 were studied.Results The onset was subacute or chronic. The body temperature was usually normal or below 37.5℃,but it rose when patient's condition deteriorated and coma appeaxed.The patient had hypoimmunity but without human immunodeficiency virus infection. Multifocal lesions in the whole brain,signs of meningeal irritation and infective myelogram were observed. Rheumatoid factor increased in the early stage and indirect bilirubin,proteins in cerebrospinal fluid(CSF), and immunoglobulin IgG,IgA increased in the middle stage.Cytological examination of CSF showed lymphocyte reaction.Blood routine test showed normal eosinophil granulocyte count.The patient was found to have pleurisy,peritonitis and cystitis.Brain magnetic resonance image(MRI)manifested plaque-like isometric T1 weight image and long T2 weight image signal in white matter of bilateral cerebral hemisphere and cerebella where FLAIR sequence showed hyperintensity.No apparent mass was identified.Contrast- enhanced MRI scan showed patchy and ring-like intensification.The neural system impairments were permanent and not improved after treatment.The pathology of brain tissue showed neuronal degeneration, karyopycnosis and Derivasculitis.The infectious agents were observed in the cytoplasm of neurons.Wister rats had muhiple organ inflammatory reaction 2 weeks after intraperitoneal inoculation of the patient's CSF and a large quantity of pathogens were found in the peritoneal lavage fluid.Conclusions The patient was PAS staining method is useful for detecting the pathogen in neurons and the rate can be raised by animal intraperitoneal cultivation
ABSTRACT
<p><b>OBJECTIVE</b>To get the genotype and allele frequency distribution of 6 short tandem repeat (STR) loci VWA, FGA, PENTAE, D6S1043, D2S1772, D7S3048 in NongQu Mongolia of China.</p><p><b>METHODS</b>Two hundred and ninety-three unrelated individuals from Nongqu Mongolian were investigated. Polymerase chain reaction and polyacrylamide gel electrophoresis were used.</p><p><b>RESULTS</b>Eighty alleles and 335 genotypes were detected, with frequencies ranging from 0.0017 to 0.2828. All the 6 loci met Hardy-Weinberg equilibrium. The statistical analysis of 6 STR loci showed the heterozygosity (H) >/= 0.7945, the discrimination power (DP) >/= 0.9160, the probability of paternity exclusion (PPE) >/= 0.5919, and the polymorphic information content (PIC) >/= 0.7617.</p><p><b>CONCLUSION</b>These results could serve as valuable data to enrich the Chinese genetic database and play an important role in Chinese population genetic forensic medical application.</p>
Subject(s)
Humans , Alleles , China , Electrophoresis, Polyacrylamide Gel , Gene Frequency , Genotype , Linkage Disequilibrium , Microsatellite Repeats , Genetics , Polymerase Chain Reaction , Polymorphism, Genetic , GeneticsABSTRACT
Objective:To investigate the variations o f mitochondrial D-loop region in gastric cancers. Methods:The D-loop region of 12 gastric cancers together with th e adjacent normal tissues were amplified by PCR and sequenced. Results: Among the 12 cases,16 mutations and 28 polymorphisms were identified with the mutations rate of 50%.There were 3 new polymophisms which we re not reported previously in the GeneBank among the 28 polymorphisms. Conclusion:We think that the mitochondrial DNA D-loop region is a highly polymorphric and mutable region and the mutation rate is relatively high in patients with gastric cancer.
ABSTRACT
<p><b>OBJECTIVE</b>To search for A3243G point mutations in mitochondrial DNA (mtDNA) from 10 cases of mitochondrial encephalomyopathy, lactic acidosis and strokelike episodes (MELAS).</p><p><b>METHODS</b>Using PCR-restriction analysis, we investigated A3243G point mutations in mtDNA of muscle and/or blood cells from 10 patients and their 8 maternal relatives. We also quantitated the A3243G mtDNA in samples harboring the mutation.</p><p><b>RESULTS</b>A3243G point mutations were identified in all muscle and/or blood samples from 10 MELAS patients. The proportion of mutant mtDNA was 10.8%-47.8% in blood (7 cases), and 39.4%-67.7% in muscle (5 cases). This ratio was invariably higher in muscle than in blood from two patients whose blood and muscle samples were both available. Younger patients usually carried higher proportions of A3243G mutant mtDNA in blood. Eight maternal relatives from 6 families were also examined. Maternal transmission of the disease could be identified in one family. No A3243G point mutations were found in mothers' blood from 3 families and siblings' blood from 2 families.</p><p><b>CONCLUSIONS</b>All 10 MELAS patients were found to have the mtDNA A3243G mutation in their muscle and/or blood. The A3243G mutation seems to be sporadic in 5 of the families examined, suggesting the mechanism of de novo mutation for the pathogenesis of their MELAS syndrome.</p>