Alveolar soft-part sarcoma of the orbit

Alveolar soft-part sarcoma is a malignant soft tissue neoplasm that involves mainly the deep soft tissues of the extremities, particularly the thighs and the buttock. Involvement of the orbit is uncommon. We describe a young child with such a tumor and illustrate the characteristic features.     

A de novo interstitial deletion of chromosome 15 band q25 as revealed by FISH-technique

We report a new chromosomal finding in a 20 month-old girl. The minor clinical features included: moderate mental retardation, microcephaly, mild hypotonia and hypertelorism. Initially, what appeared to be a terminal deletion of the long arm of one chromosome 15 [15q26-->qter] was determined to be an interstitial deletion involving band 15q25 as revealed by FISH-technique, showing the presence of intact telomeric hybridization signals. The cytogenetic diagnosis was thus modified to 46,XX, del (15) (pter-->q24::q26--> qter). Nevertheless, the function of the enzyme telomerase should not be ignored, as healing could occur following such terminal deletions. Consequently, it will remain a difficult task to distinguish terminal deletions from those that are interstitial.     

Genetic linkage of the tricho-dento-osseous syndrome to chromosome 17q21

Tricho-dento-osseous syndrome (TDO), MIM# 190320, is transmitted as a highly penetrant autosomal dominant trait that is characterized by variable clinical expression. The principal clinical features include kinky/curly hair in infancy, enamel hypoplasia, taurodontism, as well as increased thickness and density of cranial bones. Possible genetic linkage has been reported for TDO with the ABO blood group locus, but the gene defect remains unknown. We have identified four multiplex families (n = 63, 39 affected, 24 unaffected) from North Carolina segregating TDO. We previously have excluded a major locus for TDO in the ABO region for these families. Utilizing a genome-wide search strategy, we obtained conclusive evidence for linkage of the TDO syndrome locus to markers on chromosome 17q21 (D17S791, Z max = 10.54, Theta = 0.00) with no indication of genetic heterogeneity. Multipoint analysis suggests the TDO locus is located in a 7 cM chromosomal segment flanked by D17S932 and D17S941. This finding represents the first step towards isolation and cloning of the TDO gene. Identification of this gene has important implications for understanding normal and abnormal craniofacial development of hair, teeth and bone.     

FISH detection of chromosome 14q32/IgH translocations: evaluation in follicular lymphoma

A FISH strategy capable of detecting chromosome 14q32 rearrangements involving the IgH locus, including in interphase nuclei, was developed using Ig variable and constant region cosmids from the extremities of the locus in a dual hybridization approach, using signal splitting as evidence of rearrangement. The large size of the locus (1.3 Mb) and the propensity for internal deletion due to physiological VDJ recombination and isotype switching complicate analysis of this locus. We used the Ig10 cosmid, which hybridizes to C epsilon and C alpha2 at the 3' end of the constant region, in order to minimize deletion and/or splitting of the constant region probe. Cos Ig10 and the IgV18 VH probes were compared with a specific IgH-BCL2 FISH dual hybridization approach in follicular lymphoma (FL). Both were capable of detecting the t(14;18) in interphase nuclei, including in cases with no apparent abnormality by classic karyotype analysis, although the sensitivity of the IgH approach was slightly lower. We have also successfully applied these probes to whole cell cytospin preparations, rendering analysis of cryopreserved material possible, although interpretation should be limited to frequent events, particularly following cell manipulation. Analysis of flow cytometric sorted bone marrow fractions from three FL patients by FISH and FICTION showed that the t(14;18) was present in a much lower proportion of CD34 positive than negative cells but that the higher level of background hybridization limits use of these techniques for the reliable quantification of rare events.     

FISH localization of human cytoplasmic actin genes ACTB to 7p22 and ACTG1 to 17q25 and characterization of related pseudogenes

Human beta- and gamma-cytoplasmic actin genes (ACTB and ACTG1) were mapped to chromosomes 7p22 and 17q25, respectively, by fluorescence in situ hybridization (FISH). Four processed pseudogenes, beta-actin-related ACTBP9 and gamma-actin-related ACTGP1, ACTGP3, and ACTGP9, were isolated from human libraries. By PCR of somatic cell hybrid DNAs, ACTBP9 and two beta-actin-related pseudogenes (ACTBP7 and ACTBP8) were mapped to human chromosomes 18, 15, and 6, respectively. The gamma-actin-related pseudogenes were mapped by FISH to chromosomes 3q23 (ACTGP1), 20p13 (ACTGP3), and 6p21.1 (ACTGP9).     

Localization of PTH gene on pig chromosome 14q25-q28 by in situ hybridization

BACKGROUND AND OBJECTIVES: A survey of anesthesia practice was conducted among French residents in anesthesia at the end of their training. This study was performed mainly to evaluate the residents' experience in peripheral nerve blocks. METHODS: Two short clinical cases were proposed to all French residents during a telephone interview immediately before their certification. The first described the case of a young asthmatic patient admitted for an elbow fracture. The second described an elderly woman with severe aortic stenosis admitted for a supracondylar fracture of the femur. A questionnaire had been prepared and was filled in during the interview. Each resident was asked to answer according to the actual choice he or she would have made. For both cases, when general anesthesia was chosen first, the next question was to discuss which regional anesthesia would be used if general anesthesia had to be discarded. In that way, the practical knowledge about most common peripheral nerve blocks learned during residency was investigated. RESULTS: Of 77 residents registered as being at the end of their residency, 8 were on either sabbatical or maternity leave. Regional anesthesia was the first choice in 78% and 57% of cases for the first and second clinical cases, respectively. The regional anesthetic techniques chosen were axillary block (66%), interscalene block (31%), and intravenous regional anesthesia (3%) for case 1 and combined lumbar plexus and sciatic block (36%), epidural anesthesia (30%), single-shot spinal anesthesia (18%), and continuous spinal anesthesia (16%) for case 2. Throughout the residency of the group, 32 +/- 2 axillary blocks, 12 +/- 2 interscalene blocks (axillary vs interscalene, P < .0001), 21 +/- 3 femoral blocks, and 10 +/- 2 sciatic blocks (femoral vs sciatic, P < .0001) had been performed (mean +/- SEM). They had also performed 2.5 +/- 0.5 continuous spinal anesthesias and 17 +/- 3 intravenous regional anesthesias respectively. Upper extremity blocks were more often used during residency than lower extremity blocks (44 +/- 3 vs 31 +/- 4, P < .01). A peripheral nerve stimulator was routinely used by 83% of residents. CONCLUSION: French residents in anesthesiology at time of certification are better trained for peripheral nerve blocks of the upper extremity than for those of the lower extremity. Axillary plexus and femoral nerve block are the most widely used blocks, probably reflecting the techniques the most mastered among teachers. Finally, the extensive use of a peripheral nerve stimulator by residents is probably the result of the widespread use of this device by teachers in France.     

Alveolar adenoma of the lung: further characterization of this uncommon tumour

Alveolar adenoma of the lung is a poorly characterized, uncommon pulmonary lesion with proliferation of alveolar epithelium and septal mesenchyme. We describe the electron microscopy, immunohistochemistry and DNA flow cytometry in a case of alveolar adenoma in a 55-year-old woman. Alveolar adenoma appears to be a distinct benign neoplasm of the alveolar structures. Our findings further suggest that it is not a precursor of bronchioloalveolar carcinoma or other type II pneumocyte lesions of presumed malignant potential.     

A FISH study of chromosome fusion in the ICF syndrome: involvement of paracentric heterochromatin but not of the centromeres themselves

We have used double fluorescence in situ hybridisation to study the involvement of centromeres and paracentromeric heterochromatin in the chromosome abnormalities seen in the ICF syndrome. To detect centromeres, we used a probe which labelled alphoid satellite DNA, and for the paracentromeric heterochromatin a probe for classical satellite II. Our results show that it is always the paracentromeric heterochromatin of the relevant chromosomes that becomes decondensed in this syndrome and which fuses to produce multiradial configurations. However, the centromeric regions, identified by their content of alphoid satellite DNA, appear never to become decondensed and always remain outside the regions of chromosome fusion in the multiradials.     

Regional localization of human M-BCR gene to chromosome 23 band q11 in the great apes

Cassettes based on a hisG-URA3-hisG insert have been modified by the addition of an KmR-encoding gene and flanking polylinker sites, greatly simplifying construction of gene disruption vectors in Escherichia coli. After gene disruption in yeast, URA3 can then be excised by recombination between the hisG repeats flanking the gene, permitting reuse of the URA3 marker.     

Localization of the human phosphotyrosine phosphatase-related genes (h-PRL-1) to chromosome bands 1p35-p34, 17q12-q21, 11q24-q25 and 12q24

The h-PRL-1 gene codes for a new phosphotyrosine phosphatase that may play an important role in the control of basic cellular processes such as cell growth and proliferation. Using the cDNA of the h-PRL-1 gene as a probe, we examined a somatic mouse and hamster x human hybrid panel and found that chromosomes 1, 17 and 11 harbor sequences homologous to h-PRL-1. By in situ hybridization of metaphase spreads, subchromosomal localizations were determined at bands 1p35-p34, 17q12-q21 and 11q24-q25; in addition, a faint signal was detected at 12q24. The chromosomal assignment of the genes homologous to h-PRL-1 will help the investigation of its possible involvement in human diseases involving genetic alteration at these chromosomal regions.