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Biomedical subjects

J A Stockman

Publications and source records attributed to J A Stockman.

At least 55 records · Page 3Linked to original sources
PubMed1980

RBC values in low-birth-weight infants during the first seven weeks of life.

Hemoglobin, RBC mean corpuscular volume (MCV), and other RBC indices were studied in a group of 40 infants, each with a birth weight of less than 1,500 g. Results indicated that the hemoglobin level fell from 18.2 +/- 2.7 g/dL at birth to a low of 9.5 +/- 1.5 g/dL at 6 weeks of age. During this time, the MCV declined from 115 +/- fentoliters (fL) to 97 +/- 5 fL and did not again rise as the hemoglobin stabilized. Although the decline in MCV may simply reflect an aging RBC population, these data raise the possibility that RBC size may in part be determined by postnatal factors independent of time from conception.

Erythrocyte Indices↗
PubMed1980

Anemia due to inadequate iron sources or poor iron utilization.

Anemias due to dietary iron deficiency and poor iron utilization have some features in common. In both, the anemia is hypochromic and microcytic. Also in both, the levels of free erythrocyte protoporphyrin are increased, even though many of the causes of ineffective iron utilization are actually associated with normal or increased iron stores. Appropriate use of currently available assays, including a determination of the level of serum ferritin, can distinguish between many of these disorders. Above all, a logical approach with attention to the clinical response to treatment with iron medications will help achieve a rapid diagnosis.

Adolescent↗
PubMed1979

Iron absorption in the thalassemia syndromes and its inhibition by tea.

To determine the hemoglobin concentration at which iron absorption is minimal, five subjects with thalassemia major and one with thalassemia intermedia underwent a series of iron-absorption studies. The effect of tea as an inhibitor of non-heme iron absorption was also tested. Iron absorption increased as the hemoglobin concentration decreased, although iron absorption was much higher at any given hemoglobin level in the subject with thalassemia intermedia. In the subjects with thalassemia major, iron absorption averaged 10 per cent at hemoglobin concentrations between 9 and 10 and 2.7 per cent between 11 and 13 g per deciliter. The percentage of iron absorbed could be accurately predicted from the nucleated red-cell count (r = 0.91, P less than 0.001). Tea produced a 41 to 95 per cent inhibition of iron absorption. Since patients with thalassemia intermedia may absorb a large percentage of dietary iron, inhibitors of iron absorption, such as tea, may be useful in their management.

Adolescent↗
PubMed1979

A prospective randomized study to determine the efficacy of steroids in treatment of croup.

We evaluated the use of dexamethasone in the management of acute laryngotracheobronchitis (croup). Thirty patients, ranging in age from eight to 60 months, were evaluated in a prospective, double-blind study. Patients received dexamethasone, 0.3 mg/kg at the time of admission and a similar dose 2 hours later, and were compared with a placebo group receiving saline. Sixteen patients received dexamethasone and 14 patients received the placebo. Severity of each group was scored by a standardized system. Patients receiving dexamethasone had a mean admission score of 8.46 points; patients receiving placebo, 8.14. Twenty-four hours after admission the patients in the treatment group had a mean score of 1.19 as contrasted with a score of 5.58 for the placebo group (P less than 0.01). We concluded that dexamethasone when administered in adequate dosage by an intramuscular route hastens the recovery of infants and children with acute uncomplicated croup.

Child, Preschool↗
PubMed1978

L-Asparaginase-induced coagulopathy during therapy of acute lymphocytic leukemia.

L-Asparaginase-induced coagulation abnormalities were observed in all patients receivng this drug. All patients studied demonstrated low factor IX and fibrinogen levels and most (75%) had low levels of factor XI. Disturbances in other factors were much less frequent. Despite the presence of markedly abnormal coagulation studies, clinical bleeding was not observed.

Adolescent↗
PubMed1978

Aspirin-induced hemolysis: the role of concomitant oxidant (H2O2) challenge.

Studies were conducted in an attempt to determine the hemolytic potential of acetylsalicylic acid (ASA) on normal intact red blood cells (RBCs). ASA (25 mg/100 ml) did not impair RBC G-6-PD, glutathione peroxidase or catalase activity, glutathione stability, or hexose monophosphate shunt activity. Hemolysis was not observed after incubation with ASA alone but was quickly noted after exposure to ASA (25 mg/100 ml) and H2O2 (1.2%). Hemolysis did not occur with H2O2 alone but was directly proportional to the ASA concentration. Hemolysis was preceded by peroxidation of membrane lipid and was inhibited by the presence of the antioxidant, thymol. With ASA and H2O2 a marked reduction in membrane phosphatidyl ethanolamine occurred with oxidation of 20:4 and 22:6 fatty acids. No effect on phospholipids or fatty acids occurred with either ASA or H2O2 alone. Salicylic acid, singly or with H2O2, does not exhibit these effects.

Adult↗
PubMed1978

Consumptive coagulopathy. A complication of therapy of solid tumors in childhood.

The association of consumptive coagulopathy and malignancy is thought to be rare in pediatrics. In one patient with Ewing's sarcoma and in two with rhabdomyosarcoma consumptive coagulopathy developed in the presence of either diffuse metastatic disease or an extensive primary tumor. The coagulopathy was a major clinical problem, developing within five days of the onset of chemotherapy. Resolution coincided with the clinical response of the tumor.

Adolescent↗
PubMed1978

Erythrocytes of the human neonate.

This review has focused on the fetal erythrocyte. Fetal erythropoiesis, the production of a red cell with a shortened life-span, and the unique characteristics of this cell with respect to membrane structure and function, energy metabolism, and hemoglobin synthesis have been described. The hematologic manifestations of a variety of red cell abnormalities of structure, metabolism, and hemoglobin synthesis have been presented, as well as a discussion of the anemia of prematurity and selected nutritional disturbances that may distort this normal physiologic adaptation. We hope this review has served to further the reader's appreciation of this complicated and fascinating cell. Much more needs to be learned about the fetal erythrocyte. It is to be hoped that a fuller understanding of the fetal erythrocyte will provide insights into fetal development in general.

Cell Survival↗
PubMed1977

The anemia of prematurity. Factors governing the erythropoietin response.

We performed sequential studies in 45 premature infants (birth weights less than 1500 g) from 7 to 120 days of age to determine factors governing the erythropoietin response to a declining hemoglobin concentration. The hemoglobin level and the plasma erythropoietin showed a significant inverse correlation (r = 0.50, P less than 0.001), as did, even more strikingly, the plasma erythropoietin response and the infants' oxygen-unloading capacity (r = 0.55, P less than 0.001). In infants with "right-shifted" oxygen-hemoglobin dissociation curves (hemoglobin F less than 30 per cent) hemoglobin levels fell 2 to 3 g per deciliter lower than those in infants with "left-shifted" curves (hemoglobin F greater than 60 per cent) before comparable erythropoietin responses occurred. It appears that premature infants respond appropriately to alterations in oxygen unloading capacity and that the position of the oxygen-hemoglobin dissociation curve and not the hemoglobin concentration alone has a major role in modulated erythropoiesis.

Birth Weight↗
PubMed1977

Rapid correction of anemia with partial exchange transfusion.

Six pediatric patients have recently undergone eight partial exchange transfusions for anemias complicated by other clinical conditions. The procedure was well tolerated, and those patients who were in congestive heart failure exhibited good clinical improvement. This technique is particularly useful in situations where the patient is unable to tolerate the increased blood volume produced by other methods of RBC-transfusion therapy. We present a formula for estimation of partial exchange transfusion volume and suggest indications for partial exchange transfusion.

Adolescent↗
PubMed1977

Neutropenia, fever, and infection in children with acute lymphocytic leukemia.

In an attempt to determine the relationship between neutropenia (absolute granulocyte count less than 1,000/cu mm), infection, and disease status, 20 patients with acute lymphoblastic leukemia were observed for a total of 34 patient-years. Febrile episodes occurred with much greater frequency in patients during the course of treatment induction (0.9/mo), or while in relapse (2.46/mo) than while in remission (0.19/mo). A cause for fever was identified much more frequently in patients in remission, both when neutropenic and nonneutropenic. When absolute granulocyte counts fell below 200/cu mm, a cause for fever was generally identified regardless of disease status. We propose that the majority of febrile episodes in patients at the time of induction of treatment or in relapse with neutrophil counts of more than 200/cu mm are caused by the disease process rather than secondary to a diagnosable infection.

Agranulocytosis↗
PubMed1975

Iron deficiency anemia and increased urinary norepinephrine excretion.

Chronic iron deficiency in rats resulted in decreased MAO activity both in vitro and in vivo. Since MAO is an important enzyme in inactivation of catecholamines, urinary excretion of DA, NE, E, MN-NMN, and VMA was measured in 24-hour samples from 11 iron-deficient children before and after treatment with intramuscular iron. Pretreatment NE excretion was abnormally high and returned to normal (P=0.001) within one week of therapy. VMA excretion also was higher before than after treatment (P greater than 0.05), but most values were within the normal range for healthy children of comparable size. There was no significant difference between DA, E, and MN-NMN excretion before and after iron therapy. Anemic, non-iron-deficient children had normal urinary NE, E, and VMA excretion before and after transfusion. These findings suggest that the irritability, lack of attentiveness, and low performance scores of iron-deficient children may be related to alterations in catecholamine metabolic pathways secondary to dependence of MAO on adequate iron stores.

Adolescent↗