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Biomedical subjects

W H Zinkham

Publications and source records attributed to W H Zinkham.

At least 37 records · Page 2Linked to original sources
PubMed1982

Prognostic role of the intravenous urogram in children with acute leukemia.

We retrospectively studied intravenous urograms (IVU) performed at presentation on 108 children with acute leukemia in order to determine whether any association existed between an abnormal IVU and known prognostic factors at presentation, initial renal function, and outcome. Sixteen patients (14%) had abnormal IVUs. These patients were compared to the remainder of the group and found to be comparable in respect to known prognostic factors at diagnosis (P greater than 0.05). No correlation was found between abnormal renal function and an abnormal IVU. Renal enlargement was associated with shorter survival only in patients who had both adenopathy and hepatosplenomegaly (P less than 0.01). This effect did not persist in any other group of patients examined. When subjected to multivariate analysis the IVU did not significantly influence relapse or survival in these patients. Renal enlargement may be a prognostic feature in some patients with childhood leukemia. Nevertheless routine evaluation by IVU is discouraged because of potential adverse affects of urographic contrast media and the availability of noninvasive ultrasound techniques.

Adolescent↗
PubMed1980

Carboxyhemoglobin levels in an unstable hemoglobin disorder (Hb Zürich): effect on phenotypic expression.

The affinity of Hb Zurich for carbon monoxide is approximately 65 times that of normal hemoglobin. The carboxyhemoglobin content in serum from individuals with Hb Zurich ranged from 3.9 to 6.7 percent in nine nonsmokers and from 9.8 to 19.7 percent in six smokers. Rates of hemolysis and hemoglobin denaturation were less in smokers than in nonsmokers, effects that may be secondary to the stabilization of Hb Zurich by carbon monoxide.

Adolescent↗
PubMed1980

Varicella-associated thrombocytopenia: clues to the etiology of childhood idiopathic thrombocytopenic purpura.

The temporal patterns of varicella-associated thrombocytopenia in five children seen at the Johns Hopkins Hospital suggest the existence of at least two pathogenetic mechanisms: one "infectious," with thrombocytopenia during the period of viremia; the other "post-infectious," with thrombocytopenia continuing for weeks or months afterward. Because of the subtleties of many viral illnesses, the frequency with which an active infection produces childhood idiopathic thrombocytopenic purpura may be underestimated. Studies to evaluate this hypothesis may enhance our knowledge of etiologic factors and enable more rational therapy.

Chickenpox↗
PubMed1979

Elevation of pyrimidine enzyme activities in the RBC of patients with congenital hypoplastic anaemia and their parents.

The activities of orotate phosphoribosyl transferase (OPRT) and orotidine monophosphate decarboxylase (ODC) were significantly elevated (P less than 0.001) in erythrocytes (RBC) from five patients with prednisone-responsive congenital hypoplastic anaemia (CHA). (OPRT: patients - 10.1--64.2 nmol/h/10(9) RBC; controls - 2.8 +/- 0.3 (mean +/- SEM, n = 37); ODC: patients = 30--124 nmol/h/10(9) RBC; controls = 10.2 +/- 0.7 (mean SEM, n = 37).) Two patients had a less pronounced, but significant, increase of aspartate transcarbamylase activity and three patients had marginal increases of dihydroorotase activity. Dihydroorotate dehydrogenase activity was not detected in any CHA patient or control. In one patient prior to prednisone therapy, the OPRT and ODT activities were elevated 10-fold and remained elevated 3-fold after 16 months of therapy. An elevated enzyme pattern similar to that of RBC from CHA patients was observed in three parents of three CHA patients, but not in three parents of two other CHA patients. The activities of all five pyrimidine enzymes were normal for one patient with transient erythroblastopenia of childhood. In contrast, the activities of all the pyrimidine biosynthetic enzymes were elevated in blood from patients with a young RBC population: sickle cell anaemia, sickle-beta-thalassaemia, hereditary spherocytosis, and DiGuglielmo syndrome and from the newborn. It is postulated that factors which affect the activities of pyrimidine enzymes in CHA may also result in diminished erythropoiesis.

Adolescent↗
PubMed1979

Production of erythrocytes that contain fetal hemoglobin in anemia. Transient in vivo changes.

Serial microscopic immunodiffusion assays of F cells, i.e., erythrocytes that contain fetal hemoglobin (HbF), in four individuals recovering from anemia demonstrate initial increases in the percentage of circulating reticulocytes that contain HbF (F reticulocytes) and subsequent increases in the percentage of mature erythrocytes that contain HbF (F erythrocytes). In one individual responding to therapy for iron-deficiency anemia, the average percentage of F reticulocytes increased from 4.8+/-1.1 to 16.0+/-2.8% (mean+/-SD), while the mean level of F erythrocytes increased from 3.5+/-0.7 to 7.2+/-0.6%. Two normal children with transient erythroblastopenia exhibited F reticulocyte percentages of 71.3+/-6.7 and 41.5+/-1.5%, respectively, when erythropoiesis resumed. With recovery these values fell to finally measured values of 33.7+/-4.7 and 12.6+/-1.1%, respectively. In an adolescent with sickle cell anemia, F-reticulocyte percentages fluctuated between 0.6+/-1.1 and 34.0+/-2.8% and paralleled the rise and fall of total reticulocytes associated with therapy for a nasopharyngeal carcinoma. Such findings suggest that first, the production of F cells and non-F cells are separately regulated. Second, F-cell production is preferentially stimulated during escape from erythropoietic suppression and selectively depressed at the start of suppression. Third, during escape from erythropoietic suppression, F-cell production in vivo resembles that reported for in vitro cultures of erythroid stem cells. Fourth, individuals with sickle cell anemia, like individuals without hemoglobinopathies, can change their relative level of F-cell production.

Adolescent↗
PubMed1979

Observations on the rate and mechanism of hemolysis in individuals with Hb Zürich [His E7(63)beta leads to Arg]: II. Thermal denaturation of hemoglobin as a cause of anemia during fever.

Individuals with unstable hemoglobins may become more anemic during episodes of intercurrent viral or bacterial infections. Pathophysiologic mechanisms that are responsible for this phenomenon have not been elucidated. Recently we observed a patient with Hb Zürich [His E7(63)beta leads to Arg] whose anemia worsened during a febrile episode characterized by temperatures ranging between 40 degrees and 41 degrees C, splenomegaly, and the appearance of Heinz bodies in the circulating erythrocytes. There was no history of self-medication and no drugs were administered during hospitalization. To determine the effect of a 3 degrees to 4 degrees temperature elevation above the physiologic range on the rate and degree of Heinz body formation, normal (Hb A) and Hb Zürich bloods were incubated in vitro at 4 degrees C, 37 degrees C, and 41 degrees C for 3, 6, 12, and 24 hours and stained for two minutes at the end of each incubation period with rhodanile blue. No Heinz bodies appeared at 4 degrees C. The rate of Heinz body formation was significantly greater in Hb Zürich than normal blood, both at 37 degrees C and 41 degrees C. These observations suggest that in vivo exposure of red cells to temperatures in the biologic range of fever may contribute to the worsening of anemia that occurs during infections in individuals with unstable hemoglobins. Incubating whole blood at 41 degrees C for three hours and staining with rhodanile blue for two minutes appears to be a simple and effective screening test for Hb Zürich and possibly the other unstable hemoglobins. Also the technique is semi-quantitative and may be useful as a research tool for defining factors altering the in vivo stability of the unstable hemoglobins.

Adolescent↗
PubMed1979

Munchausen syndrome by proxy: definition of factitious bleeding in an infant by 51Cr labeling of erythrocytes.

The Munchausen syndrome by proxy is a phenomenon in which symptoms of a disease are fabricated by some person other than the patient. This report describes and 8-week-old infant with repetitive bleeding episodes, presumably originating from the upper respiratory tract. Extensive investigations, including angiography, several endoscopies under general anesthesia, and reinfusion of the infant's red cells labeled with 51Cr followed by pulmonary and upper airway scanning, failed to reveal the source of bleeding. Within two weeks after initiation of the 51Cr studies, radioactivity of facial blood from two separate bleeding episodes did not exceed background counts. Simultaneous examination of the infant's capillary blood, however, showed moderate to marked radioactivity. The Rh subtype of the facial blood was cc, whereas the infant's type was Cc. These findings indicated that the facial blood was factitious in origin. No further "bleeding" occurred after this information was presented to the parents. This case represents an unusual example of the Munchausen syndrome by proxy. Awareness of this entity can prevent potentially harmful investigations. Documenting its occurrence and sharing the information with parents in a nonaccusatory manner may prevent future harm to the patient.

Diagnosis, Differential↗
PubMed1978

Visceral larva migrans. A review and reassessment indicating two forms of clinical expression: visceral and ocular.

Visceral larva migrans is a disease in which the larvae of animal parasites invade human tissues but do not complete their life cycles. The most frequent cause of this illness in children is the dog roundworm, Toxocara canis. A review of the literature, as well as our clinical experience, indicates that there are two forms of clinical expression: one, visceral, and the other, ocular. In general the clinical and laboratory abnormalities (hepatomegaly, recurrent pneumonia, eosinophilia, and hyperglobulinemia) usually associated with visceral disease are absent in children with ocular abnormalities. Conversely, there is a general lack of eye complications in patients with systemic disease. Reasons for these variations in clinical expression are unknown, but immune responses of the host and the antigenic composition of the parasite may be contributing factors.

Adrenal Cortex Hormones↗
PubMed1978

Abnormalities of the peripheral blood as a presenting feature of immunodeficiency.

The predisposition of immunodeficient patients to the development of peripheral blood abnormalities is well documented. Less often recognized is the presence of immune defects in patients who initially present with "idiopathic" forms of thrombocytopenic purpura or autoimmune hemolytic anemia in the absence of symptomatology indicative of an immuno-deficiency. In this report we describe two children, each of whom had intermittent and at times severe hemolysis and thrombocytopenia secondary to formation of autoantibodies. Although the initial clinical impression was the presence of an "idiopathic" form of platelet or red cell destructive phenomenon, subsequent observations demonstrated abnormalities of the immune system which affected both B and T lymphocytes. In one of the patients there was a marked deficiency of IgA with a moderate but progressive decrease in IgM and IgG. The other patient had a moderate decrease in IgA and a failure to sensitize to dinitrochlorobenzene. Both exhibited dysmorphic features, including small stature, abnormal dentition, hyperelasticity of the skin, and hyperextensibility of the joints. Neither had significant problems with bacterial, fungal, or viral infections. These observations highlight the importance of evaluating the immune system in children with "idiopathic" forms of hemolytic anemia or thormbocytopenia. Demonstration of these abnormalities can have important therapeutic implications and may also provide information regarding the etiology of the blood abnormalities.

Adolescent↗
PubMed1977

Hemoglobin SC, SS/GPhiladelphia and SOArab diseases diagnostic importance of an integrative analysis of clinical, hematologic and electrophoretic findings.

Hemoglobin studies are presented on two children in whom electrophoretic analysis of hemolysates at alkaline pH initially suggested the diagnosis of hemoglobin SC disease. In both patients the course of the disease was unusually severe, blood smears contained irreversibly sickled cells, and crystal formation did not occur when red cells were incubated in 3 per cent sodium chloride solution. Each of these findings is inconsistent with the interpretation of the electrophoretic patterns. Family studies demonstrated that one of the patients had sickle cell anemia and was also a carrier of an alpha chain variant; citrate agar electrophoresis at pH 6.2 of the second child's hemolysate revealed that the "C-like" hemoglobin was not hemoglobin C. Tryptic peptide analyses of the nonhemoglobin S fractions showed that the first child has SS/GPhiladelphia disease and that the second child has SOArab disease. These observations emphasize the importance of integrating the clinical and hematologic data with the results of electrophoretic procedures in order to define precisely the hemoglobin abnormality in patients with sickling disorders.

Anemia, Sickle Cell↗
PubMed1977

Changing erythrocyte populations in juvenile chronic myelocytic leukemia: evidence for disordered regulation.

Fetal and adult erythrocyte characteristics were studied serially in a 30-mo-old female with juvenile chronic myelocytic leukemia. On presentation the erythrocytes exhibited predominantly fetal characteristics as indicated by 69% hemoglobin F (HbF), 1.1% hemoglobin A2 (HbA2), absent I antigen, and fetal levels of the erythrocyte enzymes, carbonic anhydrase I and II, glucose-6-phosphate dehydrogenase, hexokinase, pyruvate kinase, and lactate dehydrogenase; 100% of the erythrocytes present contained HbF. However, Orskov-Jacobs-Stewart hemolysis demonstrated that at least one adult characteristic was present. Seven months later HbF was 17%; I antigen and carbonic anhydrase I had increased to adult levels. The number of cells containing HbF had decreased to 30%. Further studies indicated that at least three new populations of red cells were present after 7 mo which had not previously been detected. Two of these populations exhibited a mixture of both fetal and adult characteristics. Such findings suggested that an ongoing disturbance of regulatory mechanisms was responsible for the variable expression of fetal versus adult erythrocyte characteristics.

Child, Preschool↗