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Biomedical subjects

L K Diamond

Publications and source records attributed to L K Diamond.

8 recordsLinked to original sources
PubMed1979

Immune suppression of erythropoiesis in transient erythroblastopenia of childhood.

Serum and IgG from four children with transient erythroblastopenia of childhood (TEC) was tested to see what effect it would have on development of erythroid colonies from bone marrow mononuclear cells. Serum and IgG specimens obtained at the time of diagnosis uniformly suppressed erythroid colony development from CFU-E. Washed bone marrow mononuclear cells from a child with TEC failed to grow in the presence of his own serum, but grew normally in the presence of isologous serum. Serum specimens obtained from patients after recovery from TEC had no effect on erythroid colony development. The anemia of TEC appears to be due to transient immune suppression of erythroid colony development.

Anemia, Aplastic↗
PubMed1976

Congenital hypoplastic anemia.

CHA, a rare failure of erythrogenesis in infancy and childhood, has been re-examined on the basis of a review of 42 cases of our own and 133 others. Although the disease may have its onset late in gestation, severe anemia usually is not found at birth but, in 75% of cases, becomes apparent within the first 4 months. Associated congenital anomalies include abnormal thumbs, webbed neck and growth retardation. Treatment with corticosteroids as soon as the diagnosis is established induces a remission in 80% of patients. Thereafter, this therapy may need to be continued, often at an extremely low dosage level, sometimes intermittently, for many years before the hemoglobin value maintains itself without medication. Spontaneous remission has occurred in a few cases after years of transfusions. Although it has long been considered that the disease was a failure of normal erythrogenesis manifest by a normocytic normochromic anemia, more exact measurements reveal that the anemia is macrocytic, with MCV usually ranging between 100 and 115 mu3. Other abnormalities of the red cells are present; in general, these resemble characteristics of fetal erythrocytes rather than normal adult cells. These red cell changes may persist even after the patient has been in remission for years, thus representing a permanent abnormality in erythrogenesis.

Adolescent↗
PubMed1975

Nucleoside-phosphorylase deficiency in a child with severely defective T-cell immunity and normal B-cell immunity.

A 5-year-old girl with a history of recurrent infection and anaemia has no measurable purine nucleoside phosphorylase (N.P.) activity in her red blood-cells. Her serum-immunoglobulin levels are normal, as are her antibody responses to thymus dependent and independent antigens. However, she has severe lymphopenia, pronounced depression of lymphocyte response to mitogenic and allogeneic cell stimuli, and greatly decreased T-cell rosette formation. Her parents are second cousins; their red cells contain less than half the normal level of N.P. activity. They also share an unusual N.P. isozyme pattern indicative of molecular hybridisation between catalytically active and inactive subunits, which strongly supports the assumption that they are heterozygous and their daughter is homozygous for a "silent" allele at the N.P. gene locus. Inherited deficiency of adenosine deaminase, an enzyme catalysing a reaction only one metabolic step away from that of N.P., is known to cause immunodeficiency. It is therefore very likely that this patient's lack of demonstrable N.P. activity is responsible for her syndrome.

B-Lymphocytes↗