Assignment of the gene encoding the beta-subunit of the electron-transfer flavoprotein (ETFB) to human chromosome 19q13.3.
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Animals↗
Biomedical subjects
R Antonacci
Publications and source records attributed to R Antonacci.
Hereditary motor and sensory neuropathy with calf hypertrophy is associated with 17p11.2 duplication.
The demyelinating type of hereditary motor and sensory neuropathy (HMSN I) is characterized by progressive weakness and atrophy of leg muscles. Six patients (age, 25-79 yr) belonging to three generations had calf hypertrophy (6 of 6), foot drop or difficulty with heel walking (4 of 6), pes cavus (3 of 6), absent or depressed tendon jerks in the lower limbs (4 of 6), and mild distal sensory loss (3 of 6). No other family member had leg atrophy. Motor conduction velocities ranged from 20 to 40 m/sec. Sural nerve biopsy showed loss of large myelinated fibers, numerous onion bulbs, and segmental demyelination and remyelination. Computed tomographic scans of leg muscles and histological and morphometric findings in gastrocnemius revealed true muscular hypertrophy. Southern blot and fluorescence in situ hybridization documented the duplication of the entire 17p11.2 segment associated with classical HMSN IA. The pathogenesis of muscle hypertrophy in our cases is unclear. Chronic leg muscle weakness and long-standing partial denervation might cause calf enlargement by a combination of compensatory "work-induced" and "stretch-induced" fiber hypertrophy. Alternatively, that all the affected family members presented calf hypertrophy might suggest the action of a genetic factor associated with the duplication at 17p11.2.
Adult↗
Molecular cloning, cDNA sequence, and chromosomal localization of the human phosphatidylinositol 3-kinase p110 alpha (PIK3CA) gene.
Phosphatidylinositol (PI) 3-kinase is a heterodimeric enzyme comprising a 110-kDa catalytic subunit and an 85-kDa regulatory subunit that binds to tyrosine phosphopeptide sites linked directly or indirectly to receptors serving diverse signal functions. Knowledge of the structure and function of PI 3-kinase was greatly advanced by the purification, cDNA cloning, and subsequent expression of the bovine enzyme. Here the cloning of the cDNA for the human p110 alpha subunit of PI 3-kinase (PIK3CA), encoding a protein 99% identical to the bovine p110, and of its gene in YAC is described. The chromosomal localization of the gene for PIK3CA is shown to be at 3q21-qter as determined using somatic cell hybrids. In situ hybridization performed using Alu-PCR from the YAC DNA located the gene in 3q26.3.
Animals↗
Characterization of chimpanzee-hamster hybrids by chromosome painting.
A panel of chimpanzee-human somatic cell hybrids was characterized by dual Alu-PCR of the chimpanzee DNA in the hybrid and subsequent hybridization of the labeled PCR products to human and chimpanzee chromosomes. In addition to the identification of the intact chimpanzee chromosomes retained in each hybrid, chromosome fragments were identified that will be useful in regional mapping. This technique also revealed the presence of centric inversions.
Animals↗
Cloning and comparative mapping of recently evolved human chromosome 22-specific alpha satellite DNA.
We have isolated and characterized a new alphoid probe, named p190.22. Its chromosomal location was investigated using fluorescence in situ hybridization. Under high stringency conditions p190.22 recognizes specifically the centromere of chromosome 22. A chromosome 22-specific alphoid subset has been previously reported in the literature (p22/1:2.1). The partial sequence and the genomic organization comparison strongly suggests that they recognize distinct subsets both specific for chromosome 22. The comparative mapping of probes p190.22 and p22/1:2.1 on chimpanzee (PTR and PPA) and gorilla (GGO) chromosomes was investigated. The two probes showed different hybridization results. p190.22, in particular, did not show any hybridization signal in these three species, suggesting a recent evolution.
Animals↗
Patient with de novo 12p+ syndrome identified as dir dup (12) (p13) using subchromosomal painting libraries from somatic cell hybrids.
Several patients with partial 12p duplications are known. An additional patient, who presented with the clinical manifestations of trisomy 12p syndrome, is described. De novo duplication 12p13.1-->pter was diagnosed using subchromosomal painting libraries obtained from somatic cell hybrids.
Adult↗
Preparation of human chromosomal painting probes from somatic cell hybrids.
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Animals↗
Single tarsoconjunctival flap (lower eyelid) for upper eyelid reconstruction ("reverse" modified Hughes procedure).
We present a two-stage reconstruction of partial or total full-thickness upper eyelid defects. In the first stage, a single tarsoconjunctival flap from the donor lower eyelid reconstitutes the posterior lamella, and a full-thickness skin graft reconstructs the anterior lamella. In the second stage, 5 to 8 weeks later, the skin tarsoconjunctival flap is severed. The single tarsoconjunctival flap we describe is analogous to the modified Hughes reconstruction for full-thickness lower eyelid defects and thus may be termed a "reverse" modified Hughes procedure. In the lid-sharing Cutler-Beard procedure, the popular alternative, the full-thickness lower lid is advanced into the upper eyelid defect. Our procedure provides greater stability due to the increased amount of vertical tarsus in the reconstructed eyelid. Also, in our procedure, the tarsoconjunctival flap is incised 1.5 to 2 mm from the lower eyelid margin rather than the 4 to 6 mm necessary to preserve the marginal artery in the Cutler-Beard procedure. With a follow up ranging from at least 6 months to over 2 years, the only complications among the 10 patients in our series were pyogenic granuloma at the edge of the donor lower eyelid, and mild, medial upper eyelid blepharoptosis. There were no cases of cicatricial entropion of the upper eyelid, a known complication of the Cutler-Beard procedure.
Aged↗
Cloning and comparative mapping of a human chromosome 4-specific alpha satellite DNA sequence.
We have isolated and characterized two human alphoid DNA clones: p4n1/4 and pZ4.1. Clone p4n1/4 identifies specifically the centromeric region of chromosome 4; pZ4.1 recognizes a subset of alphoid DNA shared by chromosomes 4 and 9. The specificity was determined using fluorescence in situ hybridization experiments on metaphase spreads and Southern blotting analysis of human-hamster somatic cell hybrids. The genomic organization of both subsets was also investigated. Comparative mapping on chimpanzee and gorilla chromosomes was performed. p4n1/4 hybridizes to chimpanzee chromosomes 11 and 13, homologs of human chromosomes 9 and 2q, respectively. On gorilla metaphase spreads, p4n1/4 hybridizes exclusively to the centromeric region of chromosome 19, partially homologous to human chromosome 17. No hybridization signal was detected on chromosome 3 of both chimpanzee and gorilla, in both species homolog of human chromosome 4. Identical comparative mapping results were obtained using pZ4.1 probe, although the latter recognizes an alphoid subset distinct from the one recognized by p4n1/4. The implications of these results in the evolution of centromeric regions of primate chromosomes are discussed.
Animals↗
Detection of a neurofibromatosis type I (NF1) homologous sequence by PCR: implications for the diagnosis and screening of genetic diseases.
The neurofibromatosis type I (NF1) gene was extensively screened for mutations using single strand conformation polymorphism (SSCP) technology. During the analysis of the NF1 GAP-related domain, electrophoretically abnormal fragments were detected. Direct sequencing of these fragments allowed us to identify the presence of a NF1 highly homologous sequence (NF1HHS). A detailed analysis of a hybrid panel located this sequence on chromosome 15q24-->qter. An accurate search through several data banks demonstrated that this sequence is a new NF1 homologue. This report shows how it is possible to find homologous sequences at random, and subsequently to make wrong interpretations.
Animals↗
Three-dimensional transcranial Doppler in acute ischemic stroke in the territory of the middle cerebral artery: clinical and CT correlation.
We studied 34 patients with acute ischemic stroke in the territory of the middle cerebral artery (MCA) by three-dimensional transcranial Doppler (TCD-3D). The parameters analyzed were: mean blood flow velocity, systolic and diastolic velocities; indices of pulsatility, hemisphere asymmetry and pulsatility transmission. Of the 34 patients 11 presented marked slowing of flow velocity in the MCA on the infarct side with an asymmetry index (AI) of over 40%, 8 patients with slightly reduced flow velocity in the MCA and an AI of 25-40%, 2 patients in whom there was indirect evidence of collateral circulations in the anterior cerebral artery distribution together with slowing of MCA flow; 5 patients had stenosis of the MCA, 9 patients showed no alterations of the Doppler parameters. The correlation between neurological symptom pattern and AI was significant (r = 0.76). Noninvasive, easy to perform, performable at once and reliable, TCD-3D is a great improvement on traditional transcranial Doppler and is especially useful in assessing the hemodynamics of the cerebral circulation in ischemic stroke.
Acute Disease↗
The use of confocal microscopy in evaluating corneal wound healing after excimer laser keratectomy.
Corneal wound healing following excimer laser keratectomy is the major cause of regression of treatment results. The amount of anterior stromal haze that develops may be influenced by topical medications. Over a period of 6 months, we followed 15 New Zealand white rabbit eyes that underwent excimer laser keratectomy with the VISX 193-nm ArF laser at a fluence of 150 mJ/cm2 for a depth of 130 microns. Eyes were randomized to treatment with prednisolone acetate, diclofenac sodium (Voltaren), a combination of both, and a control group. Drops were administered four times a day for 1 week, two times a day for 3 weeks, and the drops were then tapered. All eyes were reepithelialized by 5 to 7 days. The tandem scanning confocal microscope (TSCM) was used to evaluate the corneal wound in vivo weekly for a month and monthly for 6 months. During the early postoperative period, the TSCM revealed significant anterior stromal keratocyte activation with cell elongation and the spindle-shaped appearance of fibroblasts in all groups. Collagenous stromal scarring was evident initially, then slowly decreased in all treatment groups. This study shows that TSCM is clinically useful for successive in vivo examinations of corneal wounds after excimer laser keratectomy and for comparing the effects of various topical medications.
Animals↗