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Biomedical subjects

B Youl

Publications and source records attributed to B Youl.

12 recordsLinked to original sources
PubMed2001

Hereditary motor and sensory neuropathy-russe: new autosomal recessive neuropathy in Balkan Gypsies.

A novel peripheral neuropathy of autosomal recessive inheritance has been identified in Balkan Gypsies and termed hereditary motor and sensory neuropathy-Russe (HMSN-R). We investigated 21 affected individuals from 10 families. Distal lower limb weakness began between the ages of 8 and 16 years, upper limb involvement beginning between 10 and 43 years, with an average of 22 years. This progressive disorder led to severe weakness of the lower limbs, generalized in the oldest subject (aged 57 years), and marked distal upper limb weakness. Prominent distal sensory loss involved all modalities, resulting in neuropathic joint degeneration in two instances. All patients showed foot deformity, and most showed hand deformity. Motor nerve conduction velocity was moderately reduced in the upper limbs but unobtainable in the legs. Sensory nerve action potentials were absent. There was loss of larger myelinated nerve fibers and profuse regenerative activity in the sural nerve. HMSN-R is a new form of autosomal recessive inherited HMSN caused by a single founder mutation in a 1 Mb interval on chromosome 10q.

Adolescent↗
PubMed2000

A novel locus for autosomal recessive peripheral neuropathy in the EGR2 region on 10q23.

During our studies of Romany (Gypsy) families with hereditary motor and sensory neuropathy-Lom, we have identified a large kindred with two independently segregating autosomal recessive neuropathies. The novel disorder, named "hereditary motor and sensory neuropathy-Russe" (HMSNR), presented as a severe disabling form of Charcot-Marie-Tooth disease with prominent sensory loss, moderately reduced motor nerve conduction velocity, and a high threshold for electrical nerve stimulation. A genome scan in two branches of the large kindred detected linkage to the 10q22-q23 region containing the early growth response 2 gene (EGR2), a transcription factor with a key role in peripheral nerve myelination. The results of sequence analysis and the detection of an intragenic polymorphism allowed us to exclude EGR2 as the HMSNR gene. Further analysis done using linkage and recombination mapping refined the position of the HMSNR gene to a small interval on 10q23.2, flanked by markers D10S581 and D10S1742, telomeric to EGR2. In this interval, a conserved seven-marker haplotype is shared by all disease chromosomes, suggesting a single founder mutation. The homozygosity region is contained in bacterial-artificial-chromosome contig 1570 of the Sanger Centre physical map and has an estimated physical size of approximately 500 kb.

Charcot-Marie-Tooth Disease↗
PubMed1999

Congenital cataracts facial dysmorphism neuropathy syndrome, a novel complex genetic disease in Balkan Gypsies: clinical and electrophysiological observations.

During a study of hereditary motor and sensory neuropathy-Lom in Bulgaria, a previously unrecognized neurological disorder was encountered, mainly in Wallachian Gypsies, who represent a relatively recent genetic isolate. The disorder has been termed the congenital cataracts facial dysmorphism neuropathy (CCFDN) syndrome to emphasize its salient features. Fifty individuals from 19 extended pedigrees were identified and examined clinically and electrophysiologically. At least 1 patient from each family was admitted to the hospital in Sofia for full investigation. Pedigree analysis indicates autosomal recessive inheritance. The disorder is recognized in infancy by the presence of congenital cataracts and microcorneas. A predominantly motor neuropathy beginning in the lower limbs and later affecting the upper limbs develops during childhood and leads to severe disability by the third decade. Associated neurological features are a moderate nonprogressive cognitive deficit in most affected individuals together with pyramidal signs and mild chorea in some. Accompanying nonneurological features include short stature, characteristic facial dysmorphism, and hypogonadotrophic hypogonadism. Nerve conduction studies suggest a hypomyelinating/demyelinating neuropathy, confirmed by nerve biopsy. The CCFDN syndrome is thus a pleomorphic autosomal recessive disorder displaying a combination of neurological and nonneurological features.

Adolescent↗
PubMed1998

Correlation between varying levels of PMP22 expression and the degree of demyelination and reduction in nerve conduction velocity in transgenic mice.

Charcot-Marie-Tooth disease type 1A is most commonly caused by a duplication of a 1.5 Mb region of chromosome 17 which includes the peripheral myelin protein 22 gene (PMP22). Over-expression of this gene leads to a hypomyelinating/demyelinating neuropathy and to severely reduced nerve conduction velocity. Previous mouse and rat models have had relatively high levels of expression of the mouse or human PMP22 gene leading to severe demyelination. Here we describe five lines of transgenic mice carrying increasing copies of the human PMP22 gene (one to seven) and expressing increasing levels of the transgene. From histological and electrophysiological observations there appears to be a threshold below which expression of PMP22 has virtually no effect; below a ratio of human/mouse mRNA expression of approximately 0.8, little effect is observed. Between a ratio of 0.8 and 1.5, histological and nerve conduction velocity abnormalities are observed, but there are no behavioural signs of neuropathy. An expression ratio >1.5 leads to a severe neuropathy. A second observation concerns the histology of the different lines; the level of expression does not affect the type of demyelination, but influences the severity of involvement.

Animals↗
PubMed1998

Intercostal muscles in the rabbit: surgical anatomy and flap construction.

Demos and colleagues (1967) obtained good antireflux results from transposing an intercostal myoneurovascular pedicle around the gastro-oesophageal junction in dogs. An intact neurovascular supply is essential for the viability of a muscle flap. The aim of this study was to delineate the nerve and arterial supply to the left 11th intercostal muscle in the rabbit and to assess whether this muscle could be mobilized as a viable flap. The innervation of the muscle was studied using the methods of gross dissection in cadaveric specimens, and histological staining techniques. The arterial supply was studied using gross dissection, and aortography. In three non-recovery experiments, intercostal muscle was transposed around the gastro-oesophageal junction. The distal motor latency was recorded after electrical stimulation of the intercostal wraps. Gross dissection, histological staining techniques, and aortography showed that the left 11th intercostal muscle group in the rabbit is supplied by segmental vein, artery and nerve, running between external and internal intercostal muscles. Aortography and electrical stimulation demonstrated that the muscle group could be mobilized with an intact neurovascular supply. The left 11th intercostal muscle group has potential as a viable muscle flap for use in surgical procedures within the upper abdomen.

Animals↗
PubMed1992

Acute optic neuritis. A cognitive and magnetic resonance imaging study.

Forty-two patients with acute optic neuritis (ON) (mean duration of symptoms 14.5 d) were compared with a matched, normal control group on a battery of tests of attention and information processing speed. Approximately half the sample (55%) had brain abnormalities shown by magnetic resonance imaging (MRI) and were more impaired across a variety of tests compared with those patients without brain lesions or normal controls. There was no difference in psychometric performance other than the pegboard task between the normal control group and those ON patients without brain involvement. Significant correlations were found between total lesion area in the brain and some tests of attention. Results from the Symbol Digit-Substitution Test were particularly sensitive in this regard and could correctly identify 70% of the sample with brain lesions.

Adult↗
PubMed1991

Acute theophylline intoxication.

We describe a case of intentional acute theophylline intoxication with cardiac, cerebral, and gastrointestinal features of moderate-to-severe toxicity. The unusual metabolic and hematologic sequelae included hypokalemia, hyperglycemia, metabolic acidosis, extreme neutrophilia, increased creatinine levels attributed to muscle damage, and hematuria. The implications of these unusual findings for the management of acute theophylline intoxication include the recognition that these effects can be due to intoxication per se and do not necessarily indicate a primary endocrine disorder or infection.

Acidosis↗
PubMed1989

Epidural blood patch in the treatment of post dural puncture headache: a double blind study.

A randomised double blind controlled trial of 'epidural blood-patch' as treatment for post-dural puncture headache is presented. The method was successful in 11 out of 12 cases on its first application, the twelfth patient being relieved by a second procedure. None of six patients reported benefit from a 'sham' procedure. The rationale for the use of the technique is discussed.

Adolescent↗