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Biomedical subjects

R S Sparkes

Publications and source records attributed to R S Sparkes.

At least 253 records · Page 14Linked to original sources

Expression of an X-linked gene from an inactive human X chromosome in mouse-human hybrid cells: further evidence for the noninactivation of the steroid sulfatase locus in man.

Somatic cell hybrid clones were derived from the fusion of hypoxanthine phosphoribosyltransferase (HPRT; EC 2.4.2.8)-deficient mouse cells and two different human fibroblast strains, each carrying an X chromosome-autosome translocation. One of these had an X/11 translocation [46,X,t(X;11)(p21;q13)] and the other had an X/19 translocation [46,X,t(X;19)(q22;q13)]. The structurally normal human X chromosome is the late-replicating (genetically inactive) chromosome in these two cell strains; the rearranged X chromosome is early replicating (genetically active). One primary hybrid clone carrying both the translocated X chromosome and the structurally normal X chromosome was isolated in hypoxanthine/aminopterin/thymidine medium from each of these two cell fusion experiments. These clones were then selected in medium containing 8-azaguanine to achieve the loss of the active human HPRT locus. Five subclones from the cell hybrid with the X/11 translocation failed to express two known human X-chromosome markers [glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) and phosphoglycerate kinase (PGK; EC 2.7.2.3)] but did express human microsomal steroid sulfatase (STS; sterol-sulfate sulfohydrolase, EC 3.1.6.2). Three of these were cytogenetically analyzed and found to contain a structurally normal human X chromosome but not the X/11 translocation. Two subclones were isolated in 8-azaguanine from the hybrid with the X/19 translocation. Cytogenetic analysis of these two clones showed the presence of a structurally normal human X chromosome; the X/19 translocation was not present. They did not express human G6PD, PGK, or HPRT but did express human STS. These results indicate that human STS is expressed from a locus on the inactive human X chromosome and support our earlier finding that the STS locus escapes X-inactivation in man.

Animals↗

Origin of human bone marrow fibroblasts.

We investigated the origin of bone marrow fibroblasts in three bone marrow transplant recipients with aplastic anaemia and leukaemia who received grafts from HLA-identical siblings of opposite sex. The patients were conditioned for transplantation with high doses of cytotoxic drugs and 300--1000 rads total body irradiation. After transplantation, bone marrow cells were cultured in T flasks for 3 weeks and the adherent cells were then trypsinized and passaged weekly. After several passages the cells had the typical morphology and growth pattern of fibroblasts. Metaphases from these cells were all of recipient sex type. In contrast, haematopoietic cells and lymphocytes obtained at the same time were of donor sex type. Our findings indicate that the human bone marrow fibroblast is not derived from a precursor common to haemotopoietic cells or lymphocytes. The bone marrow fibroblast appears to be a mesenchymal cell, unrelated to haematopoietic stem cells, which is capable of in vitro proliferation after as much as 1000 rads of total body irradiation.

Adolescent↗

Tetrasomy 9p: confirmation by enzyme analysis.

A 4-day-old Caucasian male presented with midline defects of the skull and face and extensive skeletal malformations. Chromosome analysis of peripheral blood lymphocytes showed tetrasomy 9p (47,XY, + i(9p) with no evidence of mosaicism. Confirmation of the cytogenetic interpretation was obtained from the assay of the enzyme galactose-1-P uridyl transferase, the locus for which is on 9p, which showed twice the normal activity.

Abnormalities, Multiple↗

Craniosynostosis and syndactyly: expanding the 11q-- chromosomal deletion phenotype.

A patient with a partial deletion (q23 leads to qter) of the long arm of chromosome 11 presented with craniosynostosis and syndactyly. These characteristics, which have not been previously reported with 11q--, expand the phenotype of this syndrome and emphasise the need for chromosome analysis with banding techniques in multiple congenital anomaly syndromes, even if the patient could be classified as having a non-chromosomal syndrome.

Child, Preschool↗

Regional mapping of ADA and ITP on human chromosome 20: cytogenetic and somatic cell studies in an X/20 translocation.

An apparently balanced de novo translocation between chromosomes X and 20, 46,X,t(X;20)(Xp20q;Xq20p), was identified in a severely retarded 13-year-old female with macrocephaly, bilateral overfolded pinnae, elbow contractures, clinodactyly, and seizures. BudR-pulse studies show the normal X chromosome to be late replicating in both lymphocytes (50 cells) and skin fibroblasts (25 cells). An HPRT deficient Chinese hamster line was fused with lymphocytes from the patient, and hybrid lines were derived in HAT medium. Cytogenetic and biochemical analyses of these hybrid lines show that the locus for adenosine deaminase is in the cen leads to qter region and that the locus for inosine triphosphatase is in the pter leads to cen region of human chromosome 20.

Abnormalities, Multiple↗

Osteopathia striata syndrome. Clinical, genetic and radiologic considerations.

Osteopathia striata, an autosomal dominant disorder, has been diagnosed in a 19-year-old mildly retarded woman. In addition, she has macrocephaly, a leonine facies, disfigurement of the lower jaw, a cleft palate and mixed hearing loss. Roentgenograms of the skull and long bones show thickening of the calvarium, particularly at the base, mandibular hyperplasia, and striations in the long bones and pelvis. Except for the cleft palate, which has not been previously reported, and the retardation, which appears to be quite uncommon in this condition, these findings are characteristic of osteopathia striata. Because the disorder may resemble several other conditions, the differential diagnosis should include osteopoikilosis, the autosomal dominant form of osteopetrosis, and hyperostosis corticalis generalisata.

Adult↗

Probable linkage between the human galactose-1-P uridyl transferase locus and 9qh.

Evaluation of a family in which electrophoretic variants of the eznyme galactose-1-phosphate uridyl transferase (GALT) and 9qh variants occur demonstrates close linkage between these two traits: lod score of 3.67 at theta = 0. Taken with information indicating GALT is on the short arm of chromosome 9, these linkage data suggest that this locus is close to the centromere on the short arm of chromosome 9.

Blood Protein Electrophoresis↗

Chronic myelocytic leukemia: eosinophils involved in the malignant clone.

Chronic myelocytic leukemia (CML) is a clonal disorder involving neutrophil, monocyte, erythrocyte, and platelet precursors. In order to determine if the eosinophils are also involved in the leukemic clone, we purified the eosinophils from a woman heterozygous for the common electrophoretic variants of the G6PD gene. Only type B enzyme was demonstrable in the eosinophils, neutrophils, and red cells, but both A and B enzymes were found in the fibroblasts. The data provide evidence that the eosinophil is involved in the malignant clone.

Adult↗

Monozygotic twins with Crohn's disease: a case report.

Twin brothers whose monozygosity was demonstrated by analysis of dermatoglyphic patterns, chromosome banding, HLA typing, and gene markers developed Crohn's disease within 8 mo of each other. Both had involvement of the terminal ileum, colon, and rectum, as well as arthritis. However, one had severe esophagitis and recurrent pancreatitis, and the other had severe arthritis and oral mucosal involvement. Both twins had manifestations controlled by parenteral nutrition. This report describes the similarities and differences in the complicated course of Crohn's disease in identical twins and demonstrates that while the development of Crohn's disease may be genetically influenced the site of gastrointestinal involvement is affected by other factors. This experience does not support previously held concepts of the role of genetics in the clinical manifestations of Crohn's disease.

Adolescent↗