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M Vainzof

Publications and source records attributed to M Vainzof.

At least 91 records · Page 5Linked to original sources
PubMed1991

Immunofluorescence dystrophin study in Duchenne dystrophy through the concomitant use of two antibodies directed against the carboxy-terminal and the amino-terminal region of the protein.

Dystrophin immunohistochemical studies in muscle from Duchenne patients (DMD) have shown a population of fibers with partial labelling. In order to determine whether this is related to a cross reaction or to the presence of dystrophin. 22 DMD patients were studied immunohistochemically, through the concomitant use of antibodies from the N-terminal and the C-terminal regions of the protein. In 2, the reaction was negative while in 2 others 17 and 25% of fibers were positive with both antibodies. In the remainder, a population of partially stained fibers was seen: 11 were positive with both antibodies and in 7 only with the N-terminal one. Apparently, there is no correlation between the proportion of positive fibers and clinical progression, or the presence and pattern of DNA deletions in the central part of the gene. These observations led us to suggest that some truncated protein, intermediate synthesis or degradation products of dystrophin are present in muscle from Duchenne patients.

Antibodies↗
PubMed1991

Serum creatine-kinase (CK) and pyruvate-kinase (PK) activities in Duchenne (DMD) as compared with Becker (BMD) muscular dystrophy.

Serum creatine-kinase (CK) activities were determined in 536 patients affected with X-linked muscular dystrophy (456 with Duchenne or DMD and 80 with Becker or BMD) and serum pyruvate-kinase (PK) in 360 among them (309 DMD and 51 BMD). The aim of this investigation was to assess the variability and rate of decrease in serum activity in DMD as compared with BMD as a function of age and in DMD as a function of Vignos scale as well. In DMD, maximum CK and PK activities were found around 1-6 years old and the average rate of decline according to age was estimated as 0.18 per year and 0.27-0.29 for both enzymes as a function of Vignos scale (assessed in 291 cases). For BMD, maximum serum enzyme levels were found around 10-15 years old and the rate of decline of serum activity per year was 0.06 for CK and 0.07 for PK. If maximum levels of serum enzyme reflect active muscle degeneration and the rate of decline per year to progressive loss of muscle mass (responsible for the release of muscle enzymes to the blood stream) our observations suggest: (a) active muscle degeneration occurs, on average, 5 years later in the group of outliers and 10 years later in BMD as compared with severe DMD; (b) the rate in which muscle mass is lost is significantly greater in DMD than in BMD and therefore serum enzyme determinations may represent an important test for evaluation of therapeutic trials; (c) serum enzymes determination may represent an important preliminary test to discriminate in a proportion of young patients if they will develop a severe or milder phenotype.

Adolescent↗
PubMed1991

Exclusion of the gene responsible for facioscapulohumeral muscular dystrophy (FSH) at 6q23-q27.

Facioscapulohumeral muscular dystrophy (FSH) is an autosomal dominant condition with variable expressivity and age dependent penetrance. Linkage studies still did not exclude regions 11, 2q, 6q, 7p, 8p, 10q, 12p and 14p as possible locations for the FSH gene. In the present study we have analysed 80 individuals (36 patients and 44 normals) belonging to 8 unrelated Brazilian families with 3 probes located on the long arm of chromosome 6:MHB(6q22-q23), ESR(6q24-q27) and TCP1(6q25-q27). Results of linkage analysis suggest that the gene responsible for FSH muscular dystrophy is not in the region 6q23-q27.

Chromosomes, Human, Pair 6↗
PubMed1991

Limb-girdle syndrome: a genetic study of 22 large Brazilian families. Comparison with X-linked Duchenne and Becker dystrophies.

The differential clinical diagnosis between the X-linked muscular dystrophies (DMD and BMD) and autosomal recessive limb-girdle muscular dystrophy (LGMD), which is extremely important for genetic counseling, may be very difficult. The aim of the present report is to describe clinical and laboratory findings in patients from large families, with AR inheritance, in an attempt to characterize better cases which have been diagnosed as LGMD compared with the X-linked forms. The main features analysed are: age of onset and of confinement to a wheelchair, reproductive performance, serum enzymes (CK and PK) and dystrophin assessment (through immunohistochemistry and Western blot). Twenty-two families, with 62 affected patients diagnosed as limb-girdle muscular dystrophy, were included in this report. In 19 families, the patients had a milder clinical course, while in the remaining 3, the progression of the disease was continuous and clinically similar to X-linked DMD ("DMD-like"). A high consanguinity rate was observed among the parents of the affected patients (77%). No major clinical difference was observed between the X-linked and the AR forms. However, muscle dystrophin was found qualitatively and quantitatively normal in the autosomal forms but absent or abnormal in the X-linked ones. The reproductive performance was significantly higher for male than female patients. In addition, a surprising finding was the significantly greater fitness estimated for male LGMD cases as compared with Becker patients of comparable age studied in our center. The implications of such findings are discussed.

Adolescent↗
PubMed1991

Dystrophin immunofluorescence pattern in manifesting and asymptomatic carriers of Duchenne's and Becker muscular dystrophies of different ages.

In order to investigate if the same apparent decrease in dystrophin negative fibers with aging observed in mouse mdx female heterozygotes also occurs in carriers of the DMD and BMD gene, we have studied the muscle of 29 DMD carriers (19 adults and 10 young daughters of obligate carriers, including 3 manifesting carriers) and 5 adult asymptomatic heterozygotes for Becker dystrophy (BMD). All young DMD possible carriers and 11 of 24 adult DMB/BMD heterozygotes had increased serum enzymes activities. A population of dystrophin negative fibers, more evident with the use of the C-terminal antibody, was seen in the three manifesting and in a 9-yr-old possible DMD carrier. In the remaining females, a positive immunohistochemical pattern of dystrophin, which did not differ from normal controls, was observed. Our results suggest that: (1) the increased population of dystrophin negative fibers reported in young mdx female heterozygotes was not seen in young DMD carriers, aged 6-17 yr; and (2) abnormalities in dystrophin immunostaining are not easily observed and are more frequent in manifesting carriers, when the muscle is grossly altered.

Adolescent↗
PubMed1991

Estimates of genetic and environmental components of serum isocitrate dehydrogenase (ICDH) in normal twins.

Environmental (b2) and genetic heritability (h2) of serum isocitrate dehydrogenase (ICDH) were estimated in 96 pairs of healthy twins according to a path analysis model. The results showed significant heritability (0.42) and a very low environmental component (based on obesity and level of habitual physical activity), suggesting that these factors do not influence ICDH serum activity.

Adult↗
PubMed1991

Estimate of the intrafamilial correlation for serum creatine kinase and pyruvate kinase in females at risk for Duchenne and Becker muscular dystrophies.

In order to verify the possibility of nonrandom X-inactivation in females heterozygous for Duchenne (DMD) and Becker (BMD) muscular dystrophies, intrafamilial correlations and the heritabilities for serum creatine kinase (CK) and pyruvate kinase (PK) were estimated in a large sample of females belonging to families with affected patients. The results of the present investigation suggest that the apparent intrafamilial correlations for serum CK reported in previous studies in DMD families are not related with the presence of the DMD/BMD gene. Our data do not seem to support the hypothesis of a gene leading to a preferential inactivation of the X-chromosome in females at risk for the dystrophin gene.

Adolescent↗
PubMed1991

Short stature in Duchenne muscular dystrophy.

Growth rate was assessed in 187 boys affected with Duchenne muscular dystrophy (DMD) and bone age in 127 among them. Patients' heights were compared with their normal sibs, with expected stature according to midparents' stature and with normal Brazilian children of comparable age. The results showed that DMD boys have a normal length and weight at birth, but a delayed growth starting during the first years of life with a mean approximate decrease of -6.00 cm according to the expected height of the normal Brazilian population. The proportion of DMD patients with short stature (below the 3rd centile) was similar in younger boys (up to 7 years) to that in the older group (more than 7 years) of affected boys. Bone maturation in DMD boys did not differ from their normal sibs. Weight was also decreased in DMD patients as compared with normal sibs of comparable age.

Adolescent↗
PubMed1990

Dystrophin immunostaining in muscles from patients with different types of muscular dystrophy: a Brazilian study.

The localization of the protein dystrophin was studied using the immunofluorescence method, in muscle biopsies from 74 patients affected by different types of muscular dystrophy and 4 normal controls. In 15 patients with limb-girdle muscular dystrophy (LGMD) the pattern was indistinguishable from normal. Among 42 Duchenne patients (DMD), 3 were totally negative and 39 showed a variable proportion (4-30%) of partially labelled fibers. With one exception 17 Becker dystrophy patients (BMD), showed a positive sarcolemmal reaction. A diffuse reaction inside the fibers, which was not observed in normal controls, was seen in the majority of DMD and also in some of the BMD patients. Based on these observations it is suggested that in DMD, a small quantity of protein is still present or there is a cross-reaction with other proteins which share some homology with dystrophin. The present results suggest that it is possible to make a differential diagnosis between DMD and BMD through dystrophin immunohistochemistry. However, to distinguish between patients with BMD and LGMD phenotypes, or DMD and outliers, complementary immunoblot studies and quantitative determination of dystrophin are necessary.

Adolescent↗
PubMed1989

Nocturnal rhythm of growth hormone in Duchenne patients: effect of different doses of mazindol and/or cyproheptadine.

Human growth hormone (hGH) inhibition may be beneficial for Duchenne muscular dystrophy (DMD) patients and slow the rate of progression of the disease. The purpose of the present investigation was 1) to assess, before any therapeutic trial, the natural growth hormone (GH) rhythm during physiological sleep in DMD patients and in normal control boys of comparable age; 2) to evaluate the effect of different doses of two potential GH inhibitors on nocturnal GH secretion in DMD patients receiving mazindol (1-4 mg), cyproheptadine (4-8 mg), or both drugs. The results from the present investigation showed 1) wide variability in nocturnal GH secretion before medication; 2) no correlation between nocturnal GH concentration and height, age, bone age, L-dopa provocative test, or Tanner staging; and 3) no consistent effect on GH release after mazindol, cyproheptadine therapy, or combined therapy.

Adolescent↗
PubMed1988

Relation between height and clinical course in Duchenne muscular dystrophy.

We have evaluated the relation between height and rate of clinical progression in boys with Duchenne muscular dystrophy (DMD). In all, 111 DMD patients with age ranging from 2 to 23 years (mean 8.2 +/- 3.4 years) were assessed; of these patients, 92 had their height measured. Clinical course was determined through Vignos scale of functional disability, motor ability, and timed functional tests. All patients had grossly elevated serum creatine-kinase (CK) and pyruvate-kinase (PK) levels. When height was adjusted for patients' age, a statistically significant correlation was found between height and clinical course (positive with Vignos scale and negative with motor ability), suggesting that smaller boys have a better clinical course than taller patients of comparable age. These results support our previous hypothesis and suggest that growth inhibition seems to be effective in diminishing the progression of DMD.

Age Factors↗
PubMed1988

Effect of mazindol on growth hormone levels in patients with Duchenne muscular dystrophy.

Human growth hormone (HGH) inhibition may be beneficial in Duchenne muscular dystrophy (DMD) and slow down the rate of progression of the disease. The purposes of the present investigation were: 1) to assess, through pharmacological stimuli (L-dopa test), the HGH response in untreated DMD patients, and 2) to evaluate the inhibitory effect of mazindol on HGH levels as a potential treatment for DMD. In 55 DMD patients, HGH levels were measured through the L-dopa test, and 40 received mazindol. After 1 year, there was wide variability in the individual response to mazindol. An apparent diminution in the mean HGH level was observed in the whole group of patients; this was statistically significant after 3 and 6 months but not after 9 and 12 months of treatment. The results suggest that this drug is not effective for arresting growth or inhibiting HGH secretion for a prolonged period of time.

Adolescent↗
PubMed1985

Serum CK-MB activity in progressive muscular dystrophy: is it of nosologic value?

Serum creatine-kinase (CK) isoenzyme MB was measured in 53 patients affected by different types of myopathies (20 with Duchenne muscular dystrophy (DMD), eight with the Becker form (BMD), ten with the limb-girdle form (LGMD), six with the facioscapulohumeral form (FSH), and nine affected by polymyositis and in 21 normal control subjects). The aim of this study was to compare each group with the control individuals and to assess the nosologic value of CK-MB activity among some clinically similar dystrophies, which may have an important application for genetic counseling. A statistically significant increased CK-MB activity was found only in the Duchenne and Becker patients when compared with control persons (p less than 0.05). When the different groups of patients were compared among themselves, no significant difference was found between DMD and BMD or LGMD and polymyositis. However, a significant difference was found between BMD and LGMD. Based on these data, it is possible, through discriminant analysis, to estimate the relative biochemical probability of an isolated male patient belonging to either group.

Adult↗
PubMed1978

Experimental defibrination and bothropase: a study on the fibrinolytic mechanism in vivo.

Fibrinogen was depleted in dogs injected with a single dose of bothropase even if pretreatment followed by a continuous infusion of antifibrinolytic drugs was performed during defibrination. The activation of the fibrinolytic system as a secondary effect of the defibrination syndrome induced by bothropase injection was blocked completely by aprotinin (Trasylol) but not by EACA. Plasmin activity in spite of the inhibition of plasminogen activator suggests that, either an excess of activator is released in circulation or a plasmin-antiplasmin complex is dissociated by the circulating fibrin, according to the hypothesis of Ambrus and Markus [1], and Back et al. [4] for the mechanism of fibrinolysis in vivo. An experimental model is suggested for the study of the fibrinolytic mechanism in vivo, by the association of defibrinating agents, antivenom and antifibrinolytic drugs.

Afibrinogenemia↗
PubMedDate not supplied

Congenital muscular dystrophy with cerebral white matter hypodensity. Correlation of clinical features and merosin deficiency.

We report clinical and pathological findings in 9 children affected by congenital muscular dystrophy with normal or borderline intelligence and hypodensity of cerebral white matter (CMD-HWM), also frequently called 'occidental or western form of cerebro-muscular dystrophy' (OCMD). Our patients have uniform, distinct, clinical presentation that includes: normal or subnormal intelligence, severe, slowly progressive motor disability, high rate of facial involvement and dysmorphic aspect, increased creatine kinase levels and variable degrees of abnormal, radiographic, cerebral white matter pattern. By comparing our cases with previous reports we suggest that this subtype of CMD is not uncommon in Brazil and it is represented by a particularly severe and homogeneous clinical picture with important motor disability. The immunohistochemical staining for merosin, performed on the muscle biopsy of 6 among 9 patients, showed that all are merosin negative.

Cerebral Cortex↗