Search PubMed⌕ Search

Biomedical subjects

V Ionasescu

Publications and source records attributed to V Ionasescu.

At least 37 records · Page 2Linked to original sources

Multiple congenital anomalies syndrome with myopathy in chromosome 16 abnormality.

An abnormality of chromosome 16 in an eight year-old male was associated with a multiple congenital anomalies syndrome characterized by myopathy, cataracts, blepharophimosis, microcephaly, failure to grow, profound mental retardation, moderate sensorineural hearing loss, grand mal seizures, bilateral inguinal hernia, and thoracolumbar kyphoscoliosis. Magnetic resonance imaging of the head demonstrated absence of the corpus callosum and extensive loss of brain parenchyma in the occipital regions. Chromosome analysis from peripheral blood of the patient showed a recombinant chromosome 16 [46, XY, rec (16), dup (p13.1----p13.3) del (q22----q24)]. The mother had a pericentric inversion of chromosome 16 [46, XX, inv(16) (p13.1;q22)]. Independent recombinant DNA studies have shown that the breakpoints of these chromosomal rearrangements flank the alpha-globin gene cluster locus.

Abnormalities, Multiple↗

Magnetic resonance imaging of children with Duchenne muscular dystrophy.

Eight children representing a spectrum of clinical states of biopsy-proven Duchenne muscular dystrophy (DMD) underwent magnetic resonance (MR) scans to assess the degree of muscular involvement and disease progression. Five muscle groups (neck, shoulder girdle, pelvic girdle, thigh and calf) were evaluated. In each case, involved muscles were clearly demarcated. Image estimates of disease severity by degree of muscle involvement correlated well with clinical staging. In our experience MR is useful for assessment of disease stage, selection of appropriate muscles for biopsy and planning for courses of physical and rehabilitation therapy.

Adipose Tissue↗

Linkage analysis of Charcot-Marie-Tooth neuropathy (HMSN type I).

Fifteen HMSN families with 218 members and documented male-to-male transmission and slow motor nerve conduction velocities were informative for linkage to Duffy blood group (Fy), antithrombin III cDNA probe (AT3) and renin (REN). Our data support linkage to Fy in 8 families (lod score = 2.45 at theta = 0) consistent with HMSN type IB. Linkage to AT3 (lod score = 1.28 at theta = 0) and linkage of Fy to AT3 (lod score = 1.61 at theta = 0) is also supported in 3 of the 8 original families. Linkage to REN (lod score = 0.78 at theta = 0), linkage of Fy to REN (lod score = 0.89 at theta = 0), and linkage of AT3 to REN (lod score = 0.88 at theta = 0) is supported in only 2 of the 8 original families. Linkage to Fy was rejected in seven families, consistent with HMSN type IA (lod score = -4.34 at theta = 0.05). Linkage to AT3 was rejected in 12 families (lod score = -9.52 at theta = 0.05). Linkage to REN was rejected in 13 families (lod score = -11.07 at theta = 0.05). Our data provide support for the concept of genetic heterogeneity in CMT hypertrophic neuropathy (HMSN type I). The linkage of HMSN type IB to Fy seems to be tighter than to AT3 and REN, strongly suggesting the mapping of HMSN type IB locus on the proximal part of the long arm of chromosome 1, close to the centromere.

Antithrombin III↗

Linkage studies of X-linked recessive spastic paraplegia using DNA probes.

A family with six males affected by X-linked spastic paraplegia (McKusick No. 31290) is described. The disease was accompanied by mental retardation in all patients (severe in four cases with IQ of 40) and by absence of extensor pollicis longus (in four cases). The following X chromosome DNA probes were used in linkage studies: 782, RC8, 99-6, 754, OTC, L128, pDP34, p43-15, DX13, and St14. The mutation is closely linked to the loci DX13 (DXS15) and St14 (DXS52) (no recombinants in 11 meioses) and therefore localised to the telomeric region of the long arm of the human X chromosome.

Adolescent↗

Localization of the gene for X-linked spinal muscular atrophy.

We used probes for DNA polymorphisms on the X chromosome to study genetic linkage in seven families with X-linked adult-onset spinal muscular atrophy. We found significant linkage to the marker DXYS1 on the proximal X chromosome long arm and loose linkage or nonlinkage to markers elsewhere. Our analysis localizes the gene defect for this form of anterior horn cell disease.

Adult↗

Gene for OTC: characterisation and linkage to Duchenne muscular dystrophy.

Cloned coding sequences for rat and human ornithine transcarbamylase (OTC) were obtained by screening a rat and a human cDNA library respectively with a synthetic oligonucleotide corresponding to 27 bases of the rat sequence. These clones, 1100 bp long for the rat clone and 1300 bp for the human, contain approximately 80% of the human OTC coding sequence. The OTC mRNA length determined by Northern blot analysis is 1700bp. The human OTC sequence was shown to be localised Xp11.4-Xp21 using somatic cell hybrids. There is a frequent RFLP revealed with the restriction enzyme MspI. OTC is located more closely to the Duchenne muscular dystrophy mutation than previously reported markers such as RC8 and L1.28, and therefore should prove useful in carrier detection and haplotype analysis of families carrying the mutation causing the disease.

Animals↗

Human smooth muscle cell cultures of the stomach. Morphologic and biochemical studies.

Smooth muscle cell cultures were prepared from stomach explants obtained surgically from 10 patients with duodenal ulcer. The cultured cells grew in either overlapping layers in "hills and valleys" or in parallel arrays. The ultrastructure studies showed plasmalemmal vesicles, bundles of myofilaments associated with dense bodies, and gap junctions. The synthesis of contractile proteins illustrated the preponderance of actin on myosin and tropomyosin. The synthesis of contractile proteins in stomach smooth muscle cell cultures is significantly higher than in skin fibroblast cultures, i.e. 20 X higher for myosin, 10 X higher for actin, and 30 X higher for tropomyosin.

Actins↗

Inherited metabolic myopathy with storage of glycoproteins and glycosaminoglycans.

Two related patients (mother and daughter, ages 28 and 5 years) showed mild to moderate weakness and atrophy of facial and shoulder muscles with congenital onset and minimal progression. Serum creatine kinase was elevated in the child. Muscle biopsy showed normal light-microscopic and histochemical findings, but scattered sarcoplasmic vacuoles with storage of granular material were evident on electron microscopy. Storage of granular material was also identified in fibroblasts which were weakly PAS-positive, stained metachromatically with toluidine blue and orthochromatically with alcian blue. Muscle glycogen values were low-normal. Repeated biochemical studies of cultured fibroblasts identified excessive storage of glycosaminoglycans and glycoproteins. The uptake of 3H-glucosamine in cultured fibroblasts was 1.7-3.4 times greater in the patients than in control individuals, while the rate of turnover of the radioisotope was normal. These findings suggest that the genetic defect in this inherited metabolic myopathy is related to excessive synthesis of glycosaminoglycans and glycoproteins.

Adult↗

Small intestinal motility in myotonic dystrophy patients.

We performed jejunal manometric studies on 10 myotonic dystrophy patients who had symptoms of disordered gastrointestinal motility. Reduced peristalsis of the duodenum and proximal jejunum was noted in 1 patient who had an upper gastrointestinal series, but the small bowel was radiographically normal in 8 other patients. None of the myotonic dystrophy patients had a normal jejunal manometry. The abnormalities included low amplitude contractions during phases 2 and 3 of the migrating motor complex and after eating, as well as a higher frequency of contractions during phase 2. Retrograde propagation of phase 3 occurred in 2 patients, and interruption of contractions during phase 3 occurred in 4 patients. The incidence of tonic contractions was also higher in myotonic dystrophy patients. We conclude that (a) abnormal small intestinal motility is common in patients with myotonic dystrophy and (b) jejunal manometry is more sensitive than barium radiographic studies in detecting small intestinal motility abnormalities in this disorder.

Adolescent↗

[Duchenne's muscular dystrophy: also in girls?].

Duchenne's muscular dystrophy is inherited as a recessive X-linked trait: Even-though it rarely appears in females it can be seen. We have examined 5 children of one family. Two boys and one girl showed typical symptoms and clinical as well as light- and electronmicroscopical findings of this disease. In order to understand the mode of the genetic pattern, we have analysed the chromosomes, proved the fatherhood and assured the increased Ca-pooling in non-necrotic muscle fibers; in vitro-examinations of the amino-acid-incorporation in ribosomes and of the synthesis of collagen in muscular cells were done as well. Evaluating all of the results, the inheritance must be X-linked recessive and the girl, with high incidence, is a so called "manifesting carrier". The explanation offers Lyons hypothesis, which suggests that in most of the girl's muscle cells the X-Chromosomes, inherited from the mother, are active and lead to the manifestation of the illness. Consequences in advising the family genetically must be taken.

Child↗

Oculogastrointestinal muscular dystrophy.

The author reports on four patients (one male, three females) from the same kindred with a newly recognized autosomal recessive condition involving striated and smooth muscle that has been designated oculogastrointestinal muscular dystrophy. It is characterized by ptosis, ophthalmoplegia, and progressive intestinal pseudo-obstruction leading to malnutrition and death before 30 y. Autopsy studies in two cases showed a severe primary myopathy of smooth muscles of the stomach and intestine with intact myenteric plexus and vagus nerves. The proposita notably had myopathic changes of striated muscles but also involvement of the peripheral nerves and central nervous system characterized by demyelinating and axonal neuropathy and focal spongiform degeneration of the posterior columns.

Adult↗

Inherited ophthalmoplegia with intestinal pseudo-obstruction.

A new inherited neuromuscular disease was identified in 4 patients (1 male, 3 females), offspring of consanguineous marriages, belonging to the same kindred. The proband was a 24-year-old female with history of ptosis and ophthalmoplegia since childhood and progressive intestinal pseudo-obstruction for the last 4 years of her life. A sural nerve biopsy showed axonal and demyelinating neuropathy. Muscle biopsies of pectoral and gastrocnemius revealed myopathic alterations with marked variation in muscle fiber size, atrophy of both fiber types and normal mitochondria. An upper gastrointestinal study showed barium in the stomach after 8 h and jejunal diverticula. Tests for absorption of fat, protein, carbohydrate, folic acid and vitamin B12 were normal. Serum levels of vitamin A and lipoproteins were also normal. The patient underwent partial gastrectomy and gastrojejunostomy. Postoperatively, she developed severe pancreatitis, sepsis, peritonitis and expired. Tissue samples from the proband and from her brother, revealed normal mucosa, but degeneration of smooth muscle of the stomach and small intestine. The myenteric plexus and vagus nerves were normal. The biochemical studies of contractile proteins (myosin, actin, tropomyosin) in the fresh and cultured smooth muscle cells of the proband obtained at the time of gastrectomy showed a 50-75% decrease in the synthesis of different contractile proteins. Turnover of contractile proteins and synthesis and turnover of collagen showed normal values. The reduction in synthesis of contractile proteins may account for the weak peristalsis and be a factor in the pathogenesis of the intestinal pseudo-obstruction.

Adult↗

Giant axonal neuropathy: normal protein composition of neurofilaments.

A 14-year-old boy had progressive weakness and ataxia since two years of age with tightly curled hair, facial diplegia, distal weakness and hypaesthesia, cerebellar syndrome and normal intelligence. He also had distal renal tubular acidosis manifested by metabolic acidosis. Sural nerve ultrastructure showed numerous giant axons packed with neurofilaments. The neurofilament major proteins of 68 000, 160 000 and 210 000 daltons found in normal sural nerve were also present in the diseased nerve indicating that the protein composition of neurofilaments which accumulates in this disorder has not been appreciably altered. The amount of 68 000 dalton neurofilament protein was two times higher in giant axonal neuropathy nerve than in the control nerve. Our results suggest that the neurofibrillary pathology in giant axonal neuropathy is due to a build-up of normal neurofilaments.

Acidosis, Renal Tubular↗

Drug trial of superoxide dismutase in Duchenne's muscular dystrophy.

A multicenter, randomized, double-blind, placebo-controlled drug trial in Duchenne's muscular dystrophy, evaluating a superoxide dismutase in 51 ambulatory patients for 18 months was conducted. Fourteen aspects of muscle strength and five of functional ability, as well as serum creatine phosphokinase (CPK) level were studied. The total change in strength, function, and CPK level did not differ significantly in the two groups. The testing method used was reliable in assessing the natural history of Duchenne's dystrophy and would, therefore, be useful in future multicenter drug trials.

Child, Preschool↗

Collagen synthesis by Duchenne myogenic clones: pathogenic implications for the disease.

Myogenic cell clones were grown in triplicates from a 3-year-old boy with Duchenne muscular dystrophy and three normal control boys matched for age. The well-differentiated Duchenne myogenic clone had lower creatine kinase activity and lower MM isozyme than the control clones. Analysis of (3H)-proline incorporation demonstrated a 2.2-fold increase in (3H)-hydroxyproline released into the medium of Duchenne myogenic cell clones, whereas intracellular (3H)-hydroxyproline levels showed normal values. These results strongly suggest that the increased amount of collagen present in Duchenne dystrophic muscle is related to the primary defect of the disease and is not due to a secondary replacement fibrosis.

Child, Preschool↗