A single MEF-2 site is a major positive regulatory element required for transcription of the muscle-specific subunit of the human phosphoglycerate mutase gene in skeletal and cardiac muscle cells.

In order to analyze the transcriptional regulation of the muscle-specific subunit of the human phosphoglycerate mutase (PGAM-M) gene, chimeric genes composed of the upstream region of the PGAM-M gene and the bacterial chloramphenicol acetyltransferase (CAT) gene were constructed and transfected into C2C12 skeletal myocytes, primary cultured cardiac muscle cells, and C3H10T1/2 fibroblasts. The expression of chimeric reporter genes was restricted in skeletal and cardiac muscle cells. In C2C12 myotubes and primary cultured cardiac muscle cells, the segment between nucleotides -165 and +41 relative to the transcription initiation site was sufficient to confer maximal CAT activity. This region contains two E boxes and one MEF-2 motif. Deletion and substitution mutation analysis showed that a single MEF-2 motif but not the E boxes had a substantial effect on skeletal and cardiac muscle-specific enhancer activity and that the cardiac muscle-specific negative regulatory region was located between nucleotides -505 and -165. When the PGAM-M gene constructs were cotransfected with MyoD into C3H10T1/2, the profile of CAT activity was similar to that observed in C2C12 myotubes. Gel mobility shift analysis revealed that when the nuclear extracts from skeletal and cardiac muscle cells were used, the PGAM-M MEF-2 site generated the specific band that was inhibited by unlabeled PGAM-M MEF-2 and muscle creatine kinase MEF-2 oligomers but not by a mutant PGAM-M MEF-2 oligomer. These observations define the PGAM-M enhancer as the only cardiac- and skeletal-muscle-specific enhancer characterized thus far that is mainly activated through MEF-2.

Cloning of mouse prolidase cDNA: predominant expression of prolidase mRNA in kidney.

We cloned mouse prolidase cDNA from a mouse liver cDNA library. Homology to human prolidase is 83.2% at the nucleotide level and 87.2% at the amino acid level. Northern blot analysis showed that while prolidase mRNA was transcribed in brain, heart, liver, and muscle, it was predominantly transcribed in kidney.

Mass spectrometric detection of the plasma prealbumin (transthyretin) variant associated with familial amyloidotic polyneuropathy.

A plasma prealbumin variant with a methionine-for-valine substitution at position 30 is closely associated with familial amyloidotic polyneuropathy (FAP) type I. Secondary ion mass spectrometry of the tryptic digest of a carrier's prealbumin could easily detect an abnormal peptide containing the substitution besides the normal peptide. This is a sensitive and reliable method for the diagnosis of FAP.

Adenovirus-mediated transfer of human acid maltase gene reduces glycogen accumulation in skeletal muscle of Japanese quail with acid maltase deficiency.

Acid maltase deficiency (AMD) causes a lysosomal glycogenosis inherited as an autosomal recessive trait. The infantile type of AMD (Pompe disease) leads to early death due to severe dysfunction of cardiac and respiratory muscles and no effective therapy is available. Replication-defective adenovirus vectors offer a promising tool for in vivo gene delivery and gene therapy. We constructed a recombinant adenovirus containing the human acid maltase (AM) cDNA downstream of the CAG promoter, composed of modified chicken beta-actin promoter and CMV IE enhancer (AxCANAM). Japanese quail with AMD was used for this study as an animal model for human AMD. When cultured fibroblasts from AMD quail were infected with AxCANAM, AM activity in the cells increased in proportion to the multiplicity of infection (MOI). When AxCANAM (4.5 x 10(8) PFU) was injected into unilateral superficial pectoral muscle of AMD quail, PAS staining showed that glycogenosomes disappeared and stainability of acid phosphatase was reduced in the injected area as compared with the contralateral muscle of the same birds. Biochemically, AM activity increased and glycogen content decreased in the injected muscle. Western blot analysis showed that AMD quail muscle injected with AxCANAM expressed human AM protein processed to active forms. These results suggest that the human AM cDNA transferred by an adenovirus vector was sufficiently expressed, leading to a marked reduction of the glycogen accumulation in the skeletal muscle of AMD quail.

Diagnosis of McArdle's disease by molecular genetic analysis of blood.

We analyzed leukocyte DNA from 32 patients with suspected McArdle's disease, 24 of whom had biochemically or histochemically proven myophosphorylase deficiency. We found that 19 were homozygous for the most common mutation at codon 49, 2 were compound heterozygotes, and 1 was a manifesting heterozygote. In six patients, we could find only one mutant allele, suggesting a still unidentified mutation on the second allele. We were unable to identify any of the known mutations in four patients. Our findings indicate that the diagnosis of McArdle's disease can be established in approximately 90% of patients using DNA isolated from leukocytes, thereby avoiding muscle biopsy.

Diagnosis of familial amyloidotic polyneuropathy: isolation of variant prealbumin.

A novel, small-scale method was developed for detecting carriers of a prealbumin variant associated with type 1 familial amyloidotic polyneuropathy (FAP). Prealbumin isolated from plasma by a two-step preliminary chromatographic procedure was further separated into two peaks by reverse-phase high-performance liquid chromatography. The normal and variant prealbumins were identified by secondary ion mass spectrometry. The procedure is relatively simple, reliable, and applicable to the definitive diagnosis of FAP in affected patients and also as a preclinical test for the offspring of patients with FAP.

Phosphoglycerate kinase deficiency: biochemical and molecular genetic studies in a new myopathic variant (PGK Alberta)

Biochemical analysis of muscle in a 37-year-old man with exercise intolerance, myalgia, recurrent myoglobinuria, and retinitis pigmentosa showed phosphoglycerate kinase (PGK) deficiency. Kinetic and physical characteristics of the mutant enzyme differed from those of two previously reported cases, suggesting a distinct mutation. Southern blot analysis showed similar bands in patient and control, but Northern blot analysis of muscle mRNA showed an abnormally large message. These data demonstrate that PGK deficiency is clinically, biochemically, and genetically heterogeneous.

Myophosphorylase gene transfer in McArdle's disease myoblasts in vitro.

McArdle's disease is due to a genetic deficiency of glycogen phosphorylase and results in a lack of glucose mobilization from glycogen during anaerobic exercise. A genetic defect in Merino sheep produces a similar picture. We constructed a first-generation adenoviral recombinant containing the full-length human phosphorylase cDNA under the control of the Rous sarcoma virus promoter. Primary myoblast cultures from phosphorylase-deficient human and sheep muscle were efficiently transduced with this vector, resulting in restoration of the phosphorylase activity. A similar correction of the genetic defect in muscles of McArdle's patients in vivo appears feasible, preferably with the use of an adeno-associated viral vector.

Double trouble: combined myophosphorylase and AMP deaminase deficiency in a child homozygous for nonsense mutations at both loci.

A 2-yr-old boy had congenital hypotonia, limb weakness, exercise intolerance and one episode of myoglobinuria. Histochemical and biochemical analysis of muscle showed a combined defect of phosphorylase and AMP deaminase. DNA analysis showed that the child was homozygous for the mutations commonly found in both McArdle's disease and AMP deaminase deficiency. The father was heterozygous for both mutations. The mother was heterozygous for the myophosphorylase gene mutation and homozygous for the mutation in the AMP deaminase 1 gene.

Cloning of bovine muscle glycogen phosphorylase cDNA and identification of a mutation in cattle with myophosphorylase deficiency, an animal model for McArdle's disease.

Genetic defects of myophosphorylase in humans cause a metabolic myopathy (McArdle's disease) characterized by exercise intolerance, cramps, and recurrent myoglobinuria. Recently, a breed of cattle with myophosphorylase deficiency has been identified: this is the first animal model of McArdle's disease. To define the molecular genetic error in the cattle, we cloned and sequenced the wild-type bovine myophosphorylase cDNA. Homology to human cDNA is 95.8% for the amino acid sequence, and 92.0% for the nucleotide sequence. Sequence homology to rabbit cDNA is 97.3% in amino acid, 90.8% in nucleotide. In the cDNA fragments amplified by RT-PCR from muscle RNA of the cattle with myophosphorylase deficiency, we identified a C-to-T substitution, changing an encoded arginine (CGG) to tryptophan (TGG) at codon 489. The mutant residue is adjacent to pyridoxal phosphate binding sites and to an active site residue, and the sequence around this mutation is highly conserved in different species.

Frequent mutations in Japanese patients with acid maltase deficiency.

We screened 22 Japanese patients with acid maltase deficiency (seven with the infantile type, eight with the juvenile type and seven with the adult type) for three previously described mutations, D645E, S529V and R672Q, and a novel mutation, R600C. Although D645E has been reported to be common in Chinese patients with the infantile type, only three of 44 alleles (two of 14 infantile type alleles) from Japanese patients harbored the D645E mutation. The S529V mutation was identified in six of 14 alleles from adult-onset patients. None of the infantile or juvenile patients harbored the S529V mutation. Therefore, S529V apparently results in the adult type disease and is common in Japanese adult-onset patients. R672Q was identified in two pairs of siblings with the juvenile type. A novel mutation, R600C, was identified in eight of 22 patients (nine of 44 alleles). Therefore, R600C is another common Japanese mutation occurring at a CpG dinucleotide "hot spot". Homozygosity for this mutation apparently results in the infantile phenotype. Genetic diagnosis by detecting these four mutations might be feasible for most Japanese patients with acid maltase deficiency.

Sudden infant death syndrome (SIDS) in a family with myophosphorylase deficiency.

A previously healthy girl died suddenly and unexpectedly at three months of age in her sleep and an autopsy failed to reveal an adequate cause of death. As the father was known to have myophosphorylase (PPL) deficiency (McArdle's disease), we performed molecular genetic analysis of the PPL gene in autopsy muscle of the proposita. The girl was homozygous for the nonsense mutation at codon 49 most commonly associated with typical McArdle's disease. This report suggests that among children presenting as Sudden Infant Death Syndrome (SIDS) there may be cases associated with myophosphorylase deficiency.

A novel missense mutation in the glycogen branching enzyme gene in a child with myopathy and hepatopathy.

We have identified a novel missense mutation in the gene for glycogen branching enzyme (GBE 1) in a 16-month-old infant with a combination of hepatic and muscular features, an atypical clinical presentation of glycogenosis type IV (GSD IV). The patient was heterozygous for a G-to-A substitution at codon 524 (R524Q), changing an encoded arginine (CGA) to glutamine (CAA), while the GBE1 gene on the other allele was not expressed. This case broadens the spectrum of mutations in patients with GSD IV and confirms the clinical and molecular heterogeneity of this disease.

Predictors for severe cardiac complications after hematopoietic stem cell transplantation.

The value of pre-transplant factors for predicting the development of cardiac complications after transplantation has been inconsistent among studies. We analyzed the impact of pre-transplant factors on the incidence of severe cardiac complications in 164 hematopoietic stem cell transplant recipients. We identified eight patients (4.8%) who experienced grade III or IV cardiac complications according to the Bearman criteria. Seven died of cardiac causes a median of 3 days after the onset of cardiac complications. On univariate analysis, both the cumulative dose of anthracyclines and the use of anthracyclines within 60 days before transplantation affected the incidence of severe cardiac complications (P=0.0091 and 0.011). The dissociation of heart rate and body temperature, which reflects "relative tachycardia", was also associated with a higher incidence of cardiac complications (P=0.024). None of the variables obtained by electrocardiography or echocardiography were useful for predicting cardiac complications after transplantation, although the statistical power might not be sufficient to detect the usefulness of ejection fraction. On a multivariate analysis, the cumulative dose of anthracyclines was the only independent significant risk factor for severe cardiac complications. We conclude that the cumulative dose of anthracyclines is the most potent predictor of cardiac complications and the administration of anthracyclines should be avoided within two months before transplantation.

Increased incidence of acute graft-versus-host disease with the continuous infusion of cyclosporine A compared to twice-daily infusion.

We retrospectively compared the incidence of acute graft-versus-host disease (GVHD) before and after September 1999, when we changed the mode of cyclosporine A (CsA) administration from twice-daily infusions (TD) (n=58) to continuous infusion (CIF) (n=71). The incidence of grade II-IV acute GVHD in the CIF group (56%) was significantly higher than that in the TD group (27%, P=0.00022). Multivariate analysis identified only two independent significant risk factors for the development of grade II-IV acute GVHD; CIF of CsA (relative risk 2.59, 95% CI 1.46-4.60, P=0.0011) and the presence of HLA mismatch (2.01, 95% CI 1.15-3.53, P=0.014). The incidence of relapse was significantly lower in the CIF group when adjusted for disease status before transplantation (0.41, 95% CI 0.18-0.95, P=0.038), which resulted in better disease-free survival in high-risk patients (43 vs 16% at 2 years, P=0.039), but not in standard-risk patients (72 vs 80%, P=0.45). CIF of CsA with a target level of 250-400 ng/ml may not be appropriate for GVHD prophylaxis in standard-risk patients.

Male predominance among Japanese adult patients with late-onset hemorrhagic cystitis after hematopoietic stem cell transplantation.

Late-onset hemorrhagic cystitis (LHC) after hematopoietic stem cell transplantation (HSCT) is mainly caused by viral infections. We retrospectively analyzed the records of 141 Japanese adult patients who underwent a first allogeneic HSCT from 1995 to 2002. In all, 19 patients developed LHC a median of 51 days after HSCT. Adenovirus (AdV) was detected in the urine of 10 LHC patients, of whom eight had AdV type 11. Five of the six available serum samples from these patients were also positive for AdV type 11, but the detection of AdV in serum was not associated with a worse outcome. Male sex and the development of grade II-IV acute graft-versus-host disease were identified as independent significant risk factors for LHC. Male predominance was detected in LHC after HSCT, as has been previously shown in children with AdV-induced acute HC. The detection of AdV DNA in serum did not predict a poor outcome.

Reverse seroconversion of hepatitis B virus after hematopoietic stem cell transplantation.

Hepatitis B virus (HBV) reactivation in patients previously positive for hepatitis B surface antibody (HBsAb), so-called reverse seroconversion, has been considered to be a rare complication after hematopoietic stem cell transplantation (HSCT). We experienced two patients who developed reverse seroconversion among nine who were HBsAb positive and Hepatitis B core antibody (HBcAb) positive before HSCT; one after autologous bone marrow transplantation (BMT) and another after allogeneic peripheral blood stem cell transplantation (PBSCT). We reviewed the literature and considered that reverse seroconversion of HBV after HSCT is not uncommon among HBsAb positive recipients. The use of corticosteroids, the lack of HBsAb in donor, and a decrease in serum HBsAb and HBcAb levels may predict reverse seroconversion after HSCT.

Molecular characterization of myophosphorylase deficiency in a group of patients from northern Italy.

We studied a group of 14 patients from Northern Italy with myophosphorylase deficiency. The disease presented considerable clinical and biochemical heterogeneity, which was reflected at the molecular level. The clinical presentation was typical in 3 patients, mild in 7 (exercise intolerance), and severe in 4 (fixed weakness). Enzyme activity was undetectable in 10 patients, below 3% of control in 3, and 13% of control in one. Enzymatic protein was detectable immunologically only in 1 patient. Myophosphorylase mRNA was present in 8 patients, but in 7 of them it was reduced in amount. Two patients were homozygous for the common nonsense R49X mutation, 5 were heterozygous. Two missense mutations not previously observed were identified in this group of patients. The frequency of alleles with the R49X mutation was significantly lower in this group of patients than in previously reported series. Myophosphorylase deficiency is genetically heterogeneous even among patients living in a small region and with a common ethnic background.

Glycogen storage myopathies.

The glycogen storage myopathies are caused by enzyme defects in the glycogenolytic or in the glycolytic pathway affecting skeletal muscle alone or in conjunction with other tissues. The authors review recent findings in this area, including a new entity, aldolase deficiency, and the wealth of molecular genetic data that are rapidly accumulating. Despite this progress, genotype-phenotyp3 correlations are still murky in most glycogen storage myopathies.

[Adult form of acid maltase deficiency presenting with pattern of muscle weakness resembling facioscapulohumeral dystrophy].

We report a 61-year-old female patient with adult form of acid maltase deficiency showing many clinical similarities to facioscapulohumeral muscular dystrophy (FSHD). She developed difficulty in raising her right arm in her thirties followed by leg weakness. She had the typical features of FSHD, including bilateral scapular winging sparing the levator scapulae and deltoid muscles, and Beevor's sign. Muscle involvement was asymmetrical. Facial muscles were not affected, while the neck flexor was weak. No muscle shortening or joint contracture was observed. On muscle CT, the lumbar paravertebral, gluteal and thigh muscles were replaced by adipose tissue, while the rectus femoris, gracilis, and sartorius muscles were spared. Serum creatine kinase level was not elevated. Muscle biopsy showed some vacuoles and many granular inclusions with high acid phosphatase activity. Acid maltase activity was very low in both muscle and cultured skin fibroblasts. Absence of shortening of affected muscles appears to be the characteristic finding suggesting metabolic myopathies with minimal fibrosis, rather than FSHD.