Biomedical subjects

V Ionasescu

Publications and source records attributed to V Ionasescu.

At least 73 records · Page 4Linked to original sources

PubMed1976

Detection of carriers and genetic counseling in duchenne muscular dystrophy by ribosomal protein synthesis.

The in vitro protein synthesis by polyribosomes extracted from biopsied muscle (vastus lateralis) was studied in 47 known carriers, 87 possible carriers and in 60 normal females. A significant increase in specific activity of monomeric ribosomes, total polyribosomes and collagen synthesis was found in 46 (97.8 per cent) known carriers and 47 (54 per cent) possible carriers of Duchenne muscular dytrophy. The latter showed an increase in ribosomal protein synthesis in 10 (52.6 per cent) of 19 mothers of isolated cases, 31 (53.3 per cent) of 58 sisters, and 6 (60 per cent) of other female relatives. Serum creatine phosphokinase was increased in 30 (63.8 per cent) of 47 known carriers.

Adult↗

PubMed1976

Protein synthesis in muscle cultures from patients with Duchenne muscular dystrophy. Calcium and A23187 ionophore dependent changes.

Muscle samples for cultures were obtained from the quadriceps by open biopsy under local anesthesia in five patients with early stage of Duchenne muscular dystrophy (DMD) and 10 controls. Primary cultures were grown in Eagle's Minimum Essential Medium (MEM) with 20 per cent fetal calf serum. After 4 weeks, cells were trypsinized, counted, subcultured for 5 days in MEM with 5 per cent horse serum and finally incubated for 4 h with (3H) leucine. Ttal protein synthesis showed a significant decrease (half of control values) only in muscle cultures from patients with DMD. Addition of calclium chloride alone or with A23187 ionophore normalized this defect in protein synthesis. By contrast, myosin heavy chain synthesis was measured and found normal in all paitents.

Anti-Bacterial Agents↗

PubMed1976

The problem of trisomy 22. A case report and a discussion of the variant forms.

A case of trisomy 22 with partial long arm deletion (47, +22 q-) studied by G-banding is presented. The patient, a five-month-old male, showed failure to thrive, delayed psychomotor development, large, low-set ears, mild micrognathia, atrial septal defect, and marked muscular hypotonia. The father's karyotype was normal. The mother's karyotype was 46 XX, but one of the no22 chromosomes showed a deletion of the long arm as seen in the proband's karyotype. A comparison with previously reported cases in the literature indicates a great variability of clinical features of trisomy 22: "classical form," cat eye syndrome, and abortive cases (as this reported case).

Abnormalities, Multiple↗

PubMed1975

Letter: Screening of the newborn for duchenne muscular dystrophy.

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Ethics, Medical↗

PubMed1975

Neurogenic control of muscle ribosomal protein synthesis.

In vitro protein synthesis of ribosomes extracted from leg muscles of 20 Sprague-Dawley rats denervated 3 and 14 days (high sciatic transections) and 10 control rats was studied. The concentration/mg protein of total ribosomes extracted from the 14-day denervated muscle showed a significant increase. Distribution of muscle polyribosomes on sucrose density gradients was normal in all cases. Noncollagen protein synthesis of the heavy polyribosomes from both early and late denervated muscles showed a significant decrease. SDS polyacrylamide gels suggested that this decrease affected the synthesis of heavy chains of myosin, while the light chains of myosin, actin and tropomyosin had normal structure and amounts. Collagen synthesis of heavy polyribosomes showed slight to moderate increase in only 50 per cent of the cases. Supplementation of ribosomes extracted from denervated muscles with normal muscle soluble enzymes increased their noncollagen synthesis by 66 per cent. This suggests that the neurogenic control of ribosomal protein synthesis is accomplished by hormonal trophic substances contained in the muscle soluble enzymes.

Animals↗

PubMed1975

Distinction between Duchenne and other muscular dystrophies by ribosomal protein synthesis.

Ribosome concentration, ribosome distribution on sucrose density gradients, and in-vitro ribosomal amino-acid incorporation (noncollagen and collagen synthesis) were studied in muscle biopsy samples obtained from 30 patients with Duchenne muscular dystrophy, seven patients with Becker muscular dystrophy, and 10 with facioscapulohumeral muscular dystrophy. Ribosome concentration was normal in Duchenne and facioscapulohumeral and decreased in Becker muscular dystrophy. Distribution of ribosomes in sucrose density gradients showed abnormalities (sharp monosomal peak and fewer polyribosomes) only in Duchenne muscular dystrophy and was normal in the other two types. In-vitro amino-acid incorporation of ribosomes in Duchenne muscular dystrophy revealed high collagen and low noncollagen synthesis of the heavy polyribosomes. This abnormality is controlled by an undetermined enzymatic factor belonging to the soluble enzyme fraction. Supplementation of the dystrophic heavy polyribosomes with normal soluble enzymes restored the synthesis of collagen to that of the controls. Heavy polyribosomes extracted from normals or from carriers produce proportionately more collagen in the presence of soluble enzyme fraction from Duchenne muscular dystrophy than in the presence of their homologous enzymes. In Becker muscular dystrophy, both noncollagen and collagen synthesis of the heavy polyribosomes were increased, under the influence of ribosomal factors. The different protein synthesis in Duchenne and Becker muscular dystrophies suggests that these conditions are non-allelic. In facioscapulohumeral muscular dystrophy the changes in protein synthesis occurred only in the early stage of the disease and consisted of increased noncollagen synthesis of the light polyribosomes, while the heavy polyribosomes had normal activity including collagen synthesis. This reaction was controlled by ribosomal factors.

Alleles↗

PubMed1975

Trisomy 22.

The existence of a trisomy 22 has been definitely established by newer methods of karyotype analysis which permit distinction between the acrocentric chromosomes of group G. Trisomy 22 is much rarer than trisomy 21. This report presents presumptive evidence that the cat eye syndrome (CES), the so-called "trisomy 22" (T22), the intermediate cases (IM) with cardinal symptoms of CES and T22, and some cases of mental retardation with rather unspecific symptoms are variants of the same disease entity. For T22, CES and one abortive case the extra chromosome was clearly identified as number 22 chromosome with or without partial deletion of the long arm. An interesting and presently not fully understood feature of trisomy 22 is its frequent familial incidence.

Abnormalities, Multiple↗

PubMed1975