Adiposity and serum parameters in hamsters fed energy restricted diets supplemented or not with trans-10,cis-12 conjugated linoleic acid

Numerous studies have demonstrated that conjugated linoleic acid (CLA) modulates body composition, reducing body fat accumulation in various mammalian species. However, very few studies have been carried out to assess the effect of CLA on previously stored body fat. The aim of the present work was to analyse the effectiveness of trans-10,cis-12 CLA in improving alterations produced by high-fat feeding in body fat and serum parameters when it was included in an energy-restricted diet. For this purpose male Syrian Golden hamsters were fed on high-fat diet for 7 weeks in order to increase their body fat content, and a further 25% energy-restricted diet supplemented or not with 0.5% trans-10,cis-12 CLA for 3 weeks. Adipose tissues, liver and gastrocnemious muscles were dissected and weighed. Adipocyte diameter and number were assessed in epididymal adipose tissue. Total cholesterol, triacylglycerols, non-esterified fatty acids and glucose were measured in serum. Three weeks of energy restriction resulted in a reduction in body weight and white adipose tissue size in all anatomical locations, without changes in liver and gastrocnemious muscle weights. Epididymal adipocyte size was reduced, but total adipocyte number remained unchanged. Serum cholesterol, triacylglycerols and glucose were significantly reduced. No differences were observed between the restricted groups (control and CLA supplemented). In conclusion, under our experimental conditions, the addition of trans-10,cis-12 CLA to the diet does not increase the benefits produced by energy restriction.

Prognostic value of minimal residual disease (MRD) in acute myeloid leukemia (AML) with favorable cytogenetics [t(8;21) and inv(16)]

Most patients with acute myeloid leukemia (AML) and t(8;21) or inv(16) have a good prognosis with current anthracycline- and cytarabine-based protocols. Tandem analysis with flow cytometry (FC) and real-time RT-PCR (RQ-PCR) was applied to 55 patients, 28 harboring a t(8;21) and 27 an inv(16), including one case with a novel CBFbeta/MYH11 transcript. A total of 31% (n=17) of CR patients relapsed: seven with t(8;21) and 10 with inv(16). The mean amount of minimal residual disease (MRD) detected by FC in relapsed and nonrelapsed patients was markedly different: 0.3 vs 0.08% (P=0.002) at the end of treatment. The mean number of fusion transcript copies/ ABL x 10(4) also differed between relapsed and non-relapsed patients: 2385 vs 122 (P=0.001) after induction, 56 vs 7.6 after intensification (P=0.0001) and 75 vs 3.3 (P=0.0001) at the end of chemotherapy. Relapses were more common in patients with FC MRD level >0.1% at the end of treatment than in patients with < or = 0.1%: cumulative incidence of relapse (CIR) was 67 and 21% (P=0.03), respectively. Likewise, using RQ-PCR, a cutoff level of >10 copies at the end of treatment correlated with a high risk of relapse: CIR was 75% for patients with RQ-PCR >10 compared to 21% for patients with RQ-PCR levels < or = 10 (P=0.04). Combined use of FC and RQ-PCR may improve MRD detection, and provide useful clinical information on relapse kinetics in AML patients.

Effects of gabapentin on the motor response to levodopa: a double-blind, placebo-controlled, crossover study in patients with complicated Parkinson disease

BACKGROUND

Motor fluctuations and dyskinesias affect many parkinsonian patients chronically treated with levodopa. Imbalance between gabaergic direct and indirect striatopallidal pathways may originate them. Manipulating GABA neurotransmission may be effective in the treatment of these patients. Gabapentin is an antiepileptic drug that increases the synthesis and release of GABA. Previous studies suggest that gabapentin may be useful in Parkinson disease (PD).

OBJECTIVE

To know the effects of gabapentin on the motor response to levodopa in PD patients with motor complications.

DESIGN

A randomized double-blind, placebo-controlled, cross-over trial with four weeks of treatment.

SETTING

A tertiary referral center.

PARTICIPANTS

Twenty subjects with PD and motor fluctuations and dyskinesias on stable antiparkinsonian treatment, took gabapentin up to a maximum dose of 2.400 mg/d in three doses and placebo.

METHODS

Three levodopa challenges were performed: at the beginning of the study and at the end of each period of treatment (4 weeks). Basal (off) and best (on) motor status were assessed by the UPDRS III. Latency to peak effect, magnitude of motor response (difference between "on" and "off" scores in the UPDRS III), duration of motor response and severity and duration of dyskinesias after each levodopa challenge were assessed. Patients' diaries were administered.

RESULTS

: Fifteen patients completed the study. A significant improvement in the basal UPDRS III resulting in a significant reduction in the magnitude of the motor response after gabapentin was obtained (P < 0.001). No other changes were observed, either on pharmacological parameters or in levodopa-induced dyskinesias. Number of daily hours spent in "on," "on with dyskinesias" and "off" also remained unchanged. Tolerance was good, dizziness being the most common side effect.

CONCLUSION

Gabapentin improved parkinsonian symptoms (basal UPDRS III and magnitude of the motor response) following levodopa. This improvement was not reflected in the daily motor situation of patients. Dyskinesias remained unchanged. Gabapentin was well tolerated. Further studies are needed to know the impact of these results in the long-term.

MEIS 1 expression is downregulated through promoter hypermethylation in AML1-ETO acute myeloid leukemias

Retroviral insertional mutagenesis in BXH2 mice commonly induces myeloid leukemias. One of the most frequently involved genes in experimental studies is Meis 1. In contrast to other genes in murine models, Meis 1 has not been affected by recurrent chromosomal translocations or point mutations in human leukemias. We found a constant downregulation of the Meis 1 gene mRNA in AML1-ETO acute myeloid leukemias and in those cases harboring in frame mutations in the bZIP domain of CEBPalpha. The absence of the Meis 1 mRNA was not caused by inactivating point mutations in the coding sequence. Promoter hypermethylation was present in more than half of the cases (9/14), including samples obtained from the widely employed Kasumi-1 cell line. Double treatment with 5-Aza-2'-deoxycytidine and trichostatin A of the Kasumi-1 cell line partially reverses Meis 1 inhibition. HoxA9 levels were also low. In a cell line model (U937 Tet AML1-ETO), AML1-ETO expression was not associated with Meis 1 suppression at 72 h. Nevertheless, Meis 1 repression is dependent on the AML1-ETO transcript levels in treated leukemic patients. Chimeric products that arise from chromosomal translocations may be associated with locus-specific epigenetic inactivation. It remains to be investigated when this methylation process is acquired and which are the basic mechanisms underlying these molecular events in AML1-ETO and CEBPalpha-mutated AML.

[Hypothesis: Parkinson's disease, reward deficiency syndrome and addictive effects of levodopa]

Since Parkinson's disease (PD) patients could suffer from a reward deficiency syndrome, they are particularly prone to develop addictive behaviours. Dopamine is involved in reward processing and in addiction. Pulsatile administration of antiparkinsonian drugs may lead to the development of dyskinesias and addictive behaviours. However, this phenomenon occurs in very few cases. Indeed, both processes share molecular mechanisms although with some differences such as the topography of the changes (it predominates in motor regions in PD with dyskinesias and in limbic regions in addictions). Nevertheless, investigations conducted to know the physiopathology of levodopa-induced dyskinesias may lead to important cues for understanding the underlying mechanisms responsible for addiction. Thus, this may have important implications for the discovery of new therapeutic strategies.

[Muscular dystrophy due to a deficit of gamma-sarcoglycan. A report of three patients with the Delta-521t mutation]

INTRODUCTION

gamma-sarcoglicanopathies, also classified as limb girdle muscular dystrophy type 2C (LGMD2C) are a group of autosomal recessive muscular dystrophies due to mutations in 13q12 and subsequent g sarcoglican deficiency. The protein is one of the components of the dystrophin associated glycoprotein complex and is thought to impart structural integrity to the myofibre. The clinical course of the disease may be heterogeneous, ranging from severe forms with onset in the first decade and rapid progression resembling Progressive Duchenne muscular dystrophy (DMD) to milder forms with later onset and slower course. Cases hitherto reported in Spain corresponds to gypsie patients, homozygous for C283Y missense mutation.

CASE REPORTS

Here, we report three new galician (Northwest Spain) patients (one male and one female sibling cases) with a severe DMD like muscular dystrophy homozygous for D 521T. In the first male familial case, initial diagnosis of DMD was made. On reevaluation fourteen years later, inmunohistochemical and molecular studies allowed for a definitive g sarcoglicanopathy diagnosis.

CONCLUSIONS

Patients with a primary sarcoglycanopathy may be clinically indistinguishable from those with the primary dystrophinopathies. Probably, the diagnosis of LGMD are underestimated and a number of male patients diagnosed as DMD really corresponds to a recessive form o muscular dystrophy. Consequently, a definitive diagnosis rests on appropriate inmunohistochemical and molecular analysis, specially in those patients showing a normal pattern of dystrophin and/or suggestive for an autosomal recessive mode of inheritance.

Distal anterior compartment myopathy: a dysferlin mutation causing a new muscular dystrophy phenotype

We report a family with a new phenotype of autosomal recessive muscle dystrophy caused by a dysferlin mutation. The onset of the illness is distal, in the muscles of the anterior compartment group. The disease is rapidly progressive, leading to severe proximal weakness. Muscle biopsy showed moderate dystrophic changes with no vacuoles. Dysferlin immunostaining was negative. Gene analysis revealed a frameshift mutation in the exon 50 (delG5966) of the DYSF gene. This phenotype further demonstrates the clinical heterogeneity of the dysferlinopathies.

Novel mutations in the muscle chloride channel CLCN1 gene causing myotonia congenita in Spanish families

Mutations in the muscular voltage-dependent chloride channel gene (CLCN1), located at 7q35, lead to recessive and dominant myotonia congenita. We report four novel mutations identified in this gene, after clinical, electromyographic, and genetic studies performed on 13 unrelated families. Two of the four mutations (2512insCTCA and A218T) were identified in families with Thomsen's disease, one (Q658X) in a family with Becker's disease, and the fourth (R669C) in a presumably sporadic patient with the Becker phenotype. Although identification of the mutations allows us to establish some genotype/phenotype correlations, this does not wholly account for the clinical heterogeneity and the inheritance patterns of the disease.

Calpainopathy-a survey of mutations and polymorphisms

Limb-girdle muscular dystrophy type 2A (LGMD2A) is an autosomal recessive disorder characterized mainly by symmetrical and selective atrophy of the proximal limb muscles. It derives from defects in the human CAPN3 gene, which encodes the skeletal muscle-specific member of the calpain family. This report represents a compilation of the mutations and variants identified so far in this gene. To date, 97 distinct pathogenic calpain 3 mutations have been identified (4 nonsense mutations, 32 deletions/insertions, 8 splice-site mutations, and 53 missense mutations), 56 of which have not been described previously, together with 12 polymorphisms and 5 nonclassified variants. The mutations are distributed along the entire length of the CAPN3 gene. Thus far, most mutations identified represent private variants, although particular mutations have been found more frequently. Knowledge of the mutation spectrum occurring in the CAPN3 gene may contribute significantly to structure/function and pathogenesis studies. It may also help in the design of efficient mutation-screening strategies for calpainopathies.

[Alterations in functional proteins. Calpaine-3 deficiency]

INTRODUCTION

Muscular dystrophies due to calpain deficiency are the first example of a muscular dystrophy due to the mutation of a gene codifying for a non-structural enzymatic protein of unknown function and substrate.

DEVELOPMENT

More than 70 mutations have been described in the gene structure, localized to chromosome 15. Although the time course and topography is fairly homogeneous, correlation between the different mutations and the phenotype has still to be analyzed. The age of onset of symptoms is usually between 8 and 14, with no difference between the sexes. There is a slow but uniformly progressive course starting in the pelvis and extending to the shoulder and the distal musculature. Almost all patients are confined to a wheelchair twenty years after onset of the disease. There is no facial, oculomotor or bulbar involvement and gemellar pseudohypertrophy is rare. However, a winged scapula and marked lumbar hyperlordosis is universal. No cardiac or cognitive changes have been observed. Muscle CT shows a pattern of atrophy, mainly of the posterior and medial muscle compartments and of the posterosuperficial group of the legs, which varies depending on the time the disorder has been present. This condition is the commonest etiological group of the dystrophy syndromes, especially of those of late infancy or juvenile onset, in the open populations studied to date. Muscle biopsy, stained by all methods available, is essential to rule out other types of progressive dystrophies secondary to deficiencies of structural proteins.

Characterization of monoclonal antibodies to calpain 3 and protein expression in muscle from patients with limb-girdle muscular dystrophy type 2A

Monoclonal antibodies were raised to two regions of calpain 3 (muscle-specific calcium-activated neutral protease), which is the product of the gene that is defective in limb-girdle muscular dystrophy type 2A. The antibodies produced characteristic patterns of bands on Western blots: normal calpain 3 protein was represented by bands at 94 kd, plus additional fragments at approximately 60 or 30 kd, according to the antibody used. Specificity was confirmed by the loss of all bands in patients with null gene mutations. The "normal" profile of bands was observed in muscle from 33 control subjects and 70 disease-control patients. Calpain 3 protein was found to be extremely stable in fresh human muscle, with full-size protein being detected 8 hours after the muscle had been removed. Blots of muscle from nine limb-girdle muscular dystrophy type 2A patients with defined mutations showed variation in protein expression, with seven showing a clear reduction in the abundance of protein detected. No simple relationship was found between the abundance and clinical severity. Two patients showed normal expression of the full-size 94 kd band accompanied by a clear reduction in the smaller fragments. This pattern was also observed in one patient with an undefined form of limb-girdle dystrophy. These results indicate that immunodiagnosis is feasible, but caution will need to be exercised with the interpretation of near-normal protein profiles.

Severe limb girdle muscular dystrophy in Spanish gypsies: further evidence for a founder mutation in the gamma-sarcoglycan gene

Limb-girdle muscular dystrophy type 2C (LGMD2C) is an autosomal recessive muscular dystrophy with primary gamma-sarcoglycan deficiency, generally associated with a severe clinical course. gamma-sarcoglycan, a 35kDa dystrophin-associated protein, is encoded by a single gene on chromosome 13q12. Six different mutations have been described in that gene, and it has been proved they are the origin of the disease. One of these mutations (C283Y), a G-->A transition in codon 283, was recently and exclusively identified in Gypsy patients from different European countries. We report the study of 11 LGMD2C unrelated Gypsy families (nine Spanish and two Portugese). The muscle biopsies of these patients showed a drastically decreased immunostaining with alpha and gamma-sarcoglycan antibodies. All the patients were homozygous for C283Y missense mutation, and all affected chromosomes (patients and heterozygous relatives) carried the allele 5 (112 bp) of the intragenic microsatellite D13S232. Unexpectedly, this allele is most frequent in the Caucasian population but not in the normal Gypsy population. The clinical severity of all patients demonstrates that the C283Y missense mutation in a homozygous state causes a severe LGMD2C (DMD-like). The elevated number of families ascertained let us assume that LGMD2C is prevalent in the Gypsy population, and that all the families have inherited a founding mutation.

p53 mutation in a case of blastic transformation of follicular lymphoma with double bcl-2 rearrangement (MBR and VCR)

The bcl-2 gene is rearranged in most cases of follicular lymphoma and the breakpoint clusters are found in two specific regions: mbr and mcr. Rearrangements of the immunoglobulin heavy chain genes (IgH) result in a deregulation of the gene and increased transcription of mRNA for the bcl-2 protein. In cases of rearrangement of the light chains (variant translocations), a third breakpoint has been described at the 5' part of the bcl-2 locus (vcr). In the present case, we report the molecular analysis of an FL transformed into a blastic phase unresponsive to chemotherapy. Molecular studies revealed a typical bcl-2 rearrangement at the major locus (mbr). Vcr rearrangements was also observed with only a single restriction enzyme. At the same time, SSCP analysis of exon 5 of the p53 locus disclosed an abnormal conformer. Direct sequencing revealed a point mutation at codon 163 (A --> G). Immunohistochemical analysis of the affected sites disclosed overexpression of p53 and bcl-2. It is concluded that p53 mutation can contribute to blastic transformation in cases of follicular lymphomas with double rearrangement at the bcl-2 locus (mbr/vcr).

[Muscular dystrophy due to a mutation in the gene of alpha-sarcoglycan subunit of dystrophin associated protein complex]

Linkage studies have confirmed the existence of clinical an genetic heterogeneity among the muscular dystrophies due to adhalin deficiency. We present the clinical, histological and genetic characteristics in a case of primary adhalinopathy (deficiency of the 50 kD subunit or alpha-sarcoglycan). It was a 19 years-old woman, born of non consanguineous parents, who shows a long evolution myopathy with onset before age 7, a severe evolution and becoming wheelchair bound at 10 years. She showed evident calf pseudohypertrophy and serum creatinkinase (CK) levels were elevated (40-180 times the standard level). The histological pattern showed a destructed fascicular architecture in agreement with severe muscular dystrophy, normal staining with anti-dystrophin monoclonal antibodies and abnormal staining pattern with anti-adhalin antibodies. The molecular study evidenced an homozygous point mutation (Arg-->Cys) at position 77 of exon 3 of the gene coding for the 50 kD subunit of the alpha-sarcoglycan complex localised in chromosome 17. In the light of this case, we suggest a revision of the diagnostic orientation in the muscular dystrophies and we review the new taxonomy of the limb-girdle muscular dystrophies, remarking the clinical signs which could indicate a given genetic locus.

Mutational analysis of p53 in 16 cases of acute lymphoblastic leukemia and Burkitt's lymphoma

BACKGROUND AND OBJECTIVE

Improvements in therapy for patients with B-cell acute lymphoblastic leukemia (ALL) and Burkitt's lymphoma (BL) depend on the identification of subsets of patients who require more intensive therapy. Abnormalities of the p53 gene are the most common molecular lesions in human cancer, and may be of prognostic significance in hematologic malignancies. In this study, we examined the p53 gene status in a group of patients with ALL/BL to determine whether some types of mutants were more frequent in this selected group of patients.

METHODS

We selected a group of 16 patients with acute lymphoblastic leukemia (ALL) and Burkitt's lymphoma (BL) in order to investigate the presence of p53 mutations. DNA obtained from affected organs (bone marrow, lymph node and a renal mass) was used for the molecular studies. Single-strand conformation polymorphism (SSCP) analysis of exons 5 to 9 of the gene was used to detect p53 mutants. After detecting an abnormal migration pattern on the SSCP, mutations were determined by direct sequencing.

RESULTS

Point mutations were found in eight patients; a misense mutation in seven cases and a non-sense mutation in one case. The normal allele was also identified in 7 mutated samples. The same mutation at codon 282 was identified in three different patients, in whom an identical conformer was detected after SSCP analysis. Mutation at codon 282 was present in an extramedular relapse (renal) appearing after a BMT. No such alteration was present in the bone marrow analyzed at the same time.

INTERPRETATION AND CONCLUSIONS

Our findings suggest that p53 mutations are quite frequent in recognized clinical groups. The criteria chosen in this study allowed us to identify a high percentage of the samples with mutation. Different malignant phenotypes could be determined by functional heterogeneity of p53 mutants.

Mutational analysis of RAG-1 in lymphoid malignancies

Illegitimate recombinase activity promoted by the recombination activating RAG-1 and RAG-2 is assumed to be involved in the pathogenesis of the chromosomal translocations observed in lymphoid neoplasias. We analyzed the complete coding region of the RAG-1 gene in patients with lymphoid neoplasis using a multiple PCR-SSCP (single strand conformation polymorphism) strategy. Nine multiple myelomas, 17 non-Hodgkin's lymphomas, 18 acute lymphocytic leukemias, 37 chronic lymphocytic leukemias and 33 non-neoplastic controls were studied. To screen the entire RAG-1 gene we used primers overlapping genomic segments of the RAG-1 coding sequence (nucleotides 87 to 3311). Samples with an abnormal band pattern in the SSCP were cloned and sequenced. Successful amplification was achieved with our protocol. The multiple PCR-SSCP analysis proved to be a feasible and sensitive strategy for studying variations in the sequence of the RAG-1 gene. No mutations other than the three previously reported sequence variations were detected. Although mutations in this gene do not appear to be common in lymphoid neoplasias, it would be interesting to ascertain whether the different variant forms of RAG-1 protein have an abnormal recombinase activity.

[Dystrophinopathies]

In 1987 a new concept in the X-linked muscular dystrophies was born with the identification of dystrophin, a cytoskeletal protein responsible for several muscular diseases previously grouped as Duchenne's or Becker's muscular dystrophies (DMD and BMD, respectively). Under the new concept these entities are referred to as dystrophinopathies. The discovery of dystrophin was made possible when polymerase chain reaction and reverse genetics opened the door to DNA examination. The DMD/BMD gene was located and sequenced and the protein product, dystrophin, was fully identified. The genetic study of dystrophinopathies was extended in the 1990's to include DNA analysis aimed at 1) discovering points of deletion or mutation that give rise to Xp21 myopathies, as dystrophinopathies are also known; 2) identifying the rules of protein translation (interruption or reading "signals" of the protein's genetic code), and 3) identifying atypical clinical phenotypes that can be diagnosed on a molecular level using anti-dystrophin antibodies or DNA probes.

A novel insertional mutation of a single base on exon 12 of the dystrophin gene

A new point mutation in exon 12 of the dystrophin gene was identified in a DMD patient using multiple SSCP analysis, which allows the simultaneous study of several exons. The mutation is an A insertion at position 1580 of the cDNA sequence, leading to a stop codon in the translational reading frame. This mutation was not observed in a sample of 70 DMD patients.