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Biomedical subjects

W J Mellman

Publications and source records attributed to W J Mellman.

At least 19 recordsLinked to original sources

Deletion mapping: further evidence for the location of acid phosphatase (ACP1) within 2p23.

The human red cell acid phosphatase (ACP1) locus was assigned to region 2p23 leads to 2pter by Ferguson-Smith et al [3], more specifically to 2p23 by Hamerton et al [5]. We describe two unrelated patients with deletion of chromosome 2, with similar breakpoints in the distal portion of band p23 (del(2) (p23)). ACP1 typing in both patients revealed heterozygous BA phenotypes. Thus, we assign the locus for ACP1 to the distal portion of 2p23.

Abnormalities, Multiple

Gene dosage effect: intraband mapping of human soluble glutamic oxaloacetic transaminase.

Quantitative assays of soluble GOT were performed on fibroblasts (from two individuals) with duplications of the long arm of chromosome 10 (10q24 leads to qter). Improved karyologic technique demonstrated that the duplications differ by half a band. Correlation of GOTS activity with the karyologic data indicates that the structural locus for GOTS maps within band 10q24. This study demonstrates the utility of this approach to fine structural mapping of the human genome.

Adult

Assignment of a gene for uridine diphosphate galactose-4-epimerase to human chromosome 1 by somatic cell hybridization, with evidence for a regional assignment to 1pter yields 1p21.

The presence of human uridine diphosphate galactose-4-epimerase (GALE) was found to correlate with the presence of chromosome 1 in somatic cell hybrids between man and mouse. The gene for GALE can therefore be assigned to human chromosome 1. Using a chromosome 1 rearrangement, we have been able to regionally assign GALE to the pter yields p21 region.

Animals

An evaluation of cytogenetic analysis as a primary tool in the assessment of recurrent pregnancy wastage.

Cytogenetic evaluation of couples with recurrent pregnancy wastage is frequently performed only after other possible etiologic factors have been excluded. Previous reports of studies using conventional and G-banding chromosome techniques in these couples have shown a higher frequency of translocations than that found in the general population. In the study reported here, both conventional and G-banded chromosome analyses were performed as a primary method of evaluation in 34 couples with recurrent fetal loss not ascertained by the birth of a child with a diagnosed chromosome disorder. Balanced translocations were found in 5 partners of the 34 couples studied. In only 2 of these cases was the translocation detected by conventional chromosome analysis. These results suggest that G-banded chromosome analysis should be a useful tool in the initial evaluation of couples with recurrent fetal wastage, rather than being recommended only after extensive investigation of other factors is unrewarding. The reproductive counseling of couples with a translocation detected on this basis is discussed.

Abortion, Habitual

Mucopolysaccharidosis in a cat with arylsulfatase B deficiency: a model of Maroteaux-Lamy syndrome.

A Siamese cat that presented clinical signs similar to those seen in humans with mucopolysaccharidoses was studied. The animal excreted increased amounts of polymeric glycosaminoglycans in the urine, consisting almost entirely of dermatan sulfate. Electron microscopy of circulating polymorphonuclear leukocytes revealed the presence of many membrane-bound lamellar inclusion bodies. Sulfate incorporation studies with cultured skin fibroblasts indicated defective glycosaminoglycan degradation. These cells showed a deficiency in arylsulfatase B activity. The disorder appears similar or identical to the Maroteaux-Lamy syndrome described in humans.

Animals

Assignment of the structural genes for the alpha subunit of hexosaminidase A, mannosephosphate isomerase, and pyruvate kinase to the region q22-qter of human chromosome 15.

Concordant segregation of the expression of the alpha subunit of human hexosaminidase A, human mannosephosphate isomerase, and pyruvate kinase was observed in somatic cell hybrids between either thymidine kinase-deficient mouse cells or thymidine kinase-deficient Chinese hamster cells and human white blood cells carrying a translocation of the distal half (q 22-qter) of the long arm of chromosome 15 to chromosome 17. A positive correlation was established between the expression of these human phenotypes and the presence of the distal half of the long arm of human chromosome 15.

Carbohydrate Epimerases

Synteny of the genes for thymidine kinase and galactokinase in the mouse and their assignment to mouse chromosome 11.

We have studied the expression of mouse galactokinase in human-mouse somatic cell hybrids segregating mouse chromosomes. Since concordant segregation of the expression of mouse galactokinase and the presence of mouse chromosome 11 were observed in the hybrid clones, we conclude that the gene for mouse galactokinase is located on mouse chromosome 11. We have also investigated the expression of mouse galactokinase in somatic cell hybrids between thymidine kinase-deficient Chinese hamster cells and mouse peritoneal macrophages. The results of this study indicate that the expression of mouse galactokinase and thymidine kinase segregates concordantly, and, therefore, we infer that the gene for mouse thymidine kinase is also located on mouse chromosome 11.

Animals

The Philadelphia variant of galactokinase.

We have previously reported the existence of a polymorphism that causes black populations to have lower mean RBC galactokinase activity than comparable white populations. We have designated this allele the Philadelphia variant, GALKP, and have suggested that it is common in blacks and rare in whites. GALKP individuals have normal WBC GALK activity, in contrast to the half normal WBC GALK activities of heterozygotes for the allele (GALKG) that causes the galactokinase-deficient form of galactosemia. In one family, we have presented evidence for the existence of two sisters heterozygous for both GALKG and GALKP alleles. These individuals have 50% normal WBC GALK activity and less than 50% normal red cell activity. The latter finding indicates that the two variant GALK alleles additively affect RBC activity. The WBC results suggest that the low activity of GALK in RBC of individuals with the GALKP allele is due to its relative instability. We could obtain no evidence for such instability from studies of high reticulocyte bloods or RBC fractionation. Furthermore, we could not demonstrate that the GALK in WBC from GALKP individuals has altered electrophoretic migration.

Alleles

Amniography for the early detection of neural tube defects.

Among the methods available for the midtrimester diagnosis of neural tube defects, it has been suggested that amniography be used to determine the presence of meningomyelocele. Twelve studies are reported in which the procedure was utilized. In 3 cases, a neural tube defect was present but was not detected by this method. The experience reported here challenges the value of this procedure and suggests that it should be evaluated further by utilizing it in cases where a positive diagnosis has been made by other methods and pregnancy termination is to be performed.

Adolescent