Biomedical subjects
Publications and source records attributed to R S Sparkes.
A girl has a stable chromosome 11, which does not reveal loss of any chromosomal material. She demonstrates small stature, mild retardation, behavior problems, mild abnormal EEG, prominent sole furrow, increased deep tendon reflexes and hypothyroidism; this latter condition may have contributed to her retardation.
Acromesomelic dwarfism is a distinct condition characterized by short stature of the short limb type, with the hands and feet showing the most obvious deviations from normal. The forearm bones are usually disproportionately shorter than the other long tubular bones of the limbs. The intelligence is normal. Available data suggest autosomal recessive transmission. Characteristic clinical and radiographic features permit establishment of a confident diagnosis in the first year of life.
Sequential chromosome examinations of peripheral lymphocte cultures were carried out on 21 adult male volunteers who smoked natural blend marijuana cigarettes containing about 1%, 2%, or no delta9-THC. For a limited number of subjects, blood samples from a single venipuncture were cultured independently in two cytogenetic laboratories, and later the slides were exchaged for re-analysis. There were significant differences between laboratories in the absolute break frequencies recorded. These inter-laboratory differences were demonstrated for both techniques of cell culture and metaphase analysis. Neither laboratory found a statistically significant increase in break frequencies asssociated with marijuana smoking. The present study, therefore, failed to detect a measurable effect of marijuana smoking on chromosomal aberrations in subjects experienced in the use of the drug.
Chinese hamster-human somatic cell hybrids were analyzed for the expression of human galactose-1-phosphate uridyltransferase (GALT; UDPglucose:alpha-D-galactose-1-phosphate uridyltransferase, EC 2.7.7.12) by electrophoresis and for the presence of human chromosomes cytogenetically with the aid of Q-banding. Three of the 10 randomly chosen independently derived primary hybrid lines showed the presence of human GALT. Human chromosome 9 was consistently present in the hybrid lines expressing human GALT and consistently absent in the lines not expressing it. Biochemical analysis alone of 11 independently derived hybrid lines showed human GALT to be syntenic with known chromosome 9 markers (soluble aconitase, adenylate kinase 1, and adenylate kinase 3). Previous studies on chromosome assignment of this locus, utilizing somatic cell hybrids, have yielded inconsistent results; one group assigned GALT to chromosome 2, and another assigned it to chromosome 3. However, we believe that, based on our results and other published evidence, the correct assignment of the human GALT locus is to chromosome 9.
A baby boy with multiple congenital anomalies and low birth weight has an apparent de novo insertional translocation into the long arm of his only X chromosome. The origin of the translocated material is not evident and both cytogenetic and X-linked marker studies do not indicate any loss of genetic material from the X chromosome. His findings are compared with other males who have X-translocations, none of which appear to be insertional translocations.
One or more differences between donors and recipients were found in polymorphic red blood cell antigens and enzymes in each of 56 bone marrow transplant sibling pairs. These results identify those polymorphic traits which are potentially most informative for detection of donor cells in a recipient following transplantation.
Three patients with chronic myelocytic leukemia in different phases of the natural history of the disease were studied. Their bone marrow cells were cultured under conditions favoring macrophage proliferation, and parallel cytogenetic and cytochemical studies were performed. All cell metaphases examined contained the Ph1 chromosome at a time when more than 80% of these metaphases were in identifiable macrophages. We conclude that the mononuclear phagocyte cell line contains the abnormal chromosome in Ph1-positive chronic myelocytic leukemia.
A boy with mental and growth retardation associated with congenital anomalies has a partial duplication of the distal 4q chromosome region as a result of inheritance of a t(4:20) from his mother. Comparison with twelve other patients from the literature indicates that similar clinical features may be associated with this chromosome change suggesting a partial 4q duplication syndrome.
Extended studies of recently described twins with ring(14) are presented. A single C band and nucleolar organizer region were observed in the r(14). Gene marker evaluations are compatible with monozygosity of the twins.
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Balanced chromosome rearrangements were found in seven of 455 retarded children vs. four of 1,679 nonretarded, psychiatric children (P less than .05). The combined incidence of non-Robertsonian balanced rearrangements from this and reported surveys of the mentally retarded was five times greater than that from newborn surveys, whereas Robertsonian translocations were not increased among the retarded. The combined data show an increase in de novo rather than familial rearrangements among the retarded; the increase in de novo rearrangements is specifically for non-Robertsonian translocation.
A linkage analysis is reported for three branches of a single family segregating for autosomal dominant retinitis pigmentosa. A statistically significant lod score of 3.9 is obtained for the RP locus and AMY2 at a recombination frequency of 1%. This linkage indicates that the RP locus is on the no. 1 chromosome since the AMY2 locus has been placed on the short arm of 1. Lod scores are reported for four other loci on chromosome 1; none of these achieve statistical significance. Analyses are reported for 23 additional autosomal markers and close linkage with RP can be excluded for a number of these.
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Alveolar macrophages were obtained from 23 patients who had received marrow transplants for hematologic disorders. The presence of a Y body in macrophages of male origin was demonstrated by fluorescence microscopy. In those patients with a marrow donor of opposite sex the alveolar macrophages were shown to be of donor origin. The disappearance with time of host macrophages indicates a life-span, under the conditions, of approximately 81 days.
The nature of the relationship between normal stem cells and the leukemic cells of chronic myelogenous leukemia (CML) is of considerable theoretical and practical importance. We studied a patient with CML who has maintained a complete hematologic remission for eight years without therapy. Presently, the only documentable abnormality is mosaicism for the Philadelphia (Ph1) chromosome. Studies of his bone marrow in vitro revealed normal colony formation in agar and normal cellular proliferation and differentiation in liquid culture. Observations in this patient indicate that a Ph1-positive clone may coexist with normal stem cells during prolonged remission in CML and the Ph1-positive cells may not always have a growth advantage over normal cells. The culture studies further suggest that the diminished proliferative capacity of the leukemic cells was not due to in vivo host suppressive factors.
A person with pure gonadal dysgenesis (XY) is described in whom peripheral leukocytes, skin, fascia, and both gonads were subjected to chromosomal analysis, confirming a lack of mosaicism. Previous case reports and the developmental and genetic basis for such an anomaly are reviewed.
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Most of the hybrid clones derived from a cross of Chinese hamster fibroblasts (DON) with rat hepatoma cells (Faza 967) showed preferential loss of rat chromosomes. Two of the hybrid clones retained the rat chromosomes, and both showed extinction of 4 liver-specific enzymes: aldolase B, liver alcohol dehydrogenase, and the inducible enzymes tyrosine aminotransferase and alanine aminotransferase. Subcloning of 1 of these hybrids, which contained 2 sets of hepatoma chromosomes and 1 set of hamster chromosomes, permitted the isolation of some clones which reexpressed 1 or more of the liver-specific enzymes. Liver alcohol dehydrogenase was the most frequently reexpressed enzyme and aldolase B the least. Tyrosine aminotransferase inducibility was reexpressed independently of basal activity, and the enzyme produced by the reexpressing hybrid cells was precipitated by a specific antiserum. No correlation was detected between the presence or absence of the marker chromosomes (large metacentrics) of the hamster parent and the extinction and reexpression of the hepatic enzymes. The results reported confirm and extend to interspecific hybrids the observation of the stable and independent reexpression of tissue-specific enzymes.