Cyclooxygenase-2, Bcl-2, and chromosome 1p analysis in protoplasmic astrocytomas

Protoplasmic astrocytomas are rare gliomas whose nosology remains enigmatic. This study retrospectively reviews the clinicopathologic features of eight tumors, including evaluation of these neoplasms for chromosome 1p loss, Bcl-2 immunoreactivity, and cyclooxygenase-2 immunoreactivity. Patients ranged in age from 3 to 49 years (median 25.5 years) and included six males and two females. All patients presented with a period of seizures (median duration of period, 54 months) before surgery. Five tumors were either totally or partially based in the temporal lobe. In the six patients for whom follow-up information was available, there was no evidence of recurrence at last known follow-up (range 5 to 171 months; median 134 months). Histologically, all tumors were marked by a proliferation of cells with rounded to oval nuclear contours and a paucity of cytoplasmic processes, arranged against a microcystic background. A rare mitotic figure was observed in only one tumor. Vascular proliferative changes and necrosis were not seen in any of the tumors. None of the tumors showed allelic loss on chromosome 1p by fluorescent in situ hybridization (FISH) analysis. Cyclooxygenase-2 (an enzyme involved in the conversion of arachidonate to prostaglandin H2 and G2) immunoreactivity was observed in two tumors. Bcl-2 (an anti-apoptotic protein) immunoreactivity was also confined to two tumors. In conclusion, protoplasmic astrocytomas appear to be low-grade neoplasms, as evidenced by their relatively benign clinical course. Although they histologically resemble microcystic oligodendrogliomas, none of the tumors showed allelic loss on chromosome 1p, a finding that has been described in the majority of low-grade oligodendrogliomas. This suggests that the protoplasmic astrocytoma is a distinct entity from low-grade oligodendroglioma. Similar to other low-grade astrocytomas, only a minority of tumors show evidence of cyclooxygenase-2 and Bcl-2 immunoreactivity.     

宁夏回族人群X染色体10个短串联重复序列位点的遗传多态性调查

目的研究宁夏回族群体X染色体上的10个短串联重复序列（DXS101、DXS6789、DXS6799、DXS6804、DXS7130、DXS7132、DXS7133、DXS7423、HPRTB、DXS8378）的基因及基因型频率分布。方法随机抽取100名宁夏回族无关个体静脉血，提取DNA，PCR扩增，变性聚丙烯酰胺凝胶电泳，银染检测结果。结果DXS101、DXS6789、DXS6799、DXS6804、DXS7130、DXS7132、DXS7133、DXS7423、HPRTB、DXS8378分别检出9、8、4、6、6、6、4、4、5和5种等位基因；分别检出17、22、7、14、14、15、6、7、12和8种基因型；基因频率分别分布在0．0087～0．3130、0．0087～0．2696、0．0348～0．5826、0．0087～0．3044、0．0261～0．4348、0．0261～0．3217、0．0261～0．6783、0．0087～0．4870、0．0261～0．4783、0．0087～0．4870之间；此10个位点女性的基因型频率分布均符合Hardy-Weinberg平衡，多态信息量除DXS7133和DXS7423外均大于0．50；女性个体识别率从0．89（DXS7133，DXS7423）至0．99（DXS101，DXS6789，DXS7132）。结论这10个X染色体短串联重复序列位点有较高的个体识别率，在个体识别和女孩亲权鉴定中有较高应用价值，对疾病相关研究有重要意义。     

Refined mapping of eight cosmid markers on human chromosome 22

Summary Eight cosmid clones were regionally assigned to small subregions of chromosome 22 by hybridization with a total of 22 somatic cell hybrids. One cosmid was localized to the proximal part of 22q which contained the region commonly deleted in the DiGeorge syndrome. Seven cosmids showing restriction fragment length polymorphisms were localized to the telomeric region distal to the MB locus, which was reported to be frequently deleted in sporadic meningioma. These cosmids, when finely mapped and ordered, are considered useful for the identification of genetic alterations on this chromosome arm.     

De novo proximal interstitial deletions of 14q: Cytogenetic and molecular investigations

We report on 2 unrelated patients who had chromosome analysis performed because of psychomotor delay, Failure to thrive, and minor anomalies. Each patient had a novel proximal 14q deletion (q11.2 to q21.1 in patient 737 and q12 to q22 in patient 777). Polymorphic (C-A)_n microsatellite markers distributed along the length of chromosome 14q were examined in both patients and their parents in order to determine which marker loci were deleted. The deletion in patient 737 was found to be paternal in origin, based on the analysis of 2 marker loci (D14S54 and D14S70), thus assigning these loci to the deleted interval q11.2 q21.1. Furthermore, 3 loci were not deleted (TCRD, D14S50, and D14S80), suggesting that they are within or proximal to 14q11.2. In the other family (patient 777), none of the markers were fully informative, but the deleted chromosome was determined to be paternally derived based on cytogenetic heteromorphisms. Despite having overlapping proximal 14q deletions, these 2 patients shared few phenotypic similarities except for failure to thrive, micrognathia, and hypoplasia of the corpus callosum. Therefore, a distinct proximal 14q deletion syndrome is not yet apparent. However, the molecular analyses facilitated the localization of several 14q DNA markers to the deletion regions in these 2 patients, while excluding other markers from each deletion. © 1994 Wiley-Liss, Inc.     

Chromosome mapping ofSoa,a gene influencing gustatory sensitivity to sucrose octaacetate in mice

Strain distribution patterns among recombinant inbred strains suggested that a locus influencing taste sensitivity to sucrose octaacetate was on chromosome 6. A location forSoa was established by linkage analysis of behavioral and electrophoretic data from outbred and congenic strains and from test-cross progeny. Haplotyping of 41 outbred CFW-Cr animals with a cDNA probe showed perfect cosegregation ofSoa andPrp, a gene for salivary proline-rich proteins. Five of twelve B6. SW-Soa ^a strains were found to retainLdr-1, lactate dehydrogenase regulator-1, on chromosome 6 as an allelic passenger from the SWR/J donor strain (source of theSoa ^a Taster allele). Centimorgan distance was estimated using the ABP/Le linkage-testing strain (non-Taster,Soa ^b) and the SWR/J strain (Taster,Soa ^a) in a testcross breeding system. The data are consistent with a position for theSoa locus on mouse chromosome 6, 62 cM from the centromere.This research was supported in part by Grants DC00150 (G. W.) and DE003658 (E.A.A.). This paper is based on a thesis submitted to the Florida State University by the first author in partial fulfillment of the requirements for the Master of Sciences degree.     

Cytogenetic studies of familial and sporadic Alzheimer disease

We present cytogenetic findings in 7 familial and 5 sporadic Alzheimer disease (AD) patients and 34 unaffected relatives, spouses, and normal controls. Our study was prompted by reports of increased chromosome abnormalities in patients and family members at risk for AD. Coded peripheral blood chromosome preparations were evaluated for aneuploidy, aberration rates, and banding patterns. Statistical analyses of our results showed no increase in aneuploidy or aberrations in AD patients, their relatives, or normals. Chromosome loss or gain in aneuploid cells was not specific except in two individuals. These two older persons studied, one with AD and one unaffected, were observed to have increased sex chromosome aneuploidy. This finding was attributed to aging and was not considered to be an effect of AD.     

Paraffin wax-embedded material as a source of DNA for the detection of somatic genetic changes

Loss of genetic material, corresponding to chromosomal deletions, has been detected in a wide range of tumours and may indicate the position of a tumour suppressor gene. In order to identify the position of such a gene more precisely, many tumour samples must be studied until a minimum consensus deletion is characterized. This process is particularly necessary for lung tumours in which the deletion in chromosome 3, seen with such high frequencies in all histological subtypes, is almost always large. We have recently described the use of the polymerase chain reaction (PCR) for restriction fragment length polymorphism (RFLP) analysis of DNA isolated from small bronchial biopsies of lung tumours. In this study we adapted this technique to allow genotyping of DNA isolated from paraffin wax-embedded material (PWEM) microdissected from glass slides. We have investigated 12 lung tumours at polymorphic loci on chromosome 3 and showed allelic loss in all samples. In adapting PCR–RFLP analysis for DNA isolated from PWEM, we have concentrated on those approaches which might be adaptable to routine clinical practice. Somatic genetic changes are now being identified in many tumour types, and this information is expected to be of diagnostic and prognostic significance.     

Ring chromosome 22 and neurofibromatosis

Variable constitutional mosaicism, mos45,XY,-22/46,XY,-22,+mar/46,XY,-22,+r(22)/47,XY,-22,+r(22)+mar/ 47, XY,-22,+r(22)*2, was found in PHA-stimulated peripheral blood, in a lymphoblastoid cell line and in cultured skin fibroblasts from a mentally retarded patient with neurofibromatosis. Both the ring chromosome and the small extra marker chromosome stained positively by in situ hybridization with a chromosome 14/22-specific alphoid repeat probe. DNA dosage analysis showed constitutional loss of one copy of the arylsulfatase A gene (ARSA), consistent with its terminal location on 22q. There was no evidence of constitutional loss of D22S1 or D22S28 which flank the neurofibromatosis type 2 (NF2) locus. Analysis of two DNA samples from a skin neurofibroma indicated retainment of two copies of D22S1, whereas the results were ambiguous with respect to tumor-specific loss of one copy of D22S28. It is suggested that the development of neurofibromatosis of unclear type in two r(22) carriers might be associated with somatic mutation of the NF2 locus due to instability of the ring chromosome(s), and in analogy, that somatic mutation of either NF1 or NF2 may account for some cases of neurofibromatosis which do not meet the criteria of either NF1 or NF2. The occurrence of seminoma in the proband may be fortuitous, but could also be due to the presence of a seminoma-associated locus on chromosome 22.