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Biomedical subjects

H A Pearson

Publications and source records attributed to H A Pearson.

At least 109 records · Page 6Linked to original sources
PubMed1977

Sickle cell anemia and severe infections due to encapsulated bacteria.

Overwhelming infections caused by encapsulated bacteria are an important cause of morbidity and death in children with sickle cell anemia. The most important contributing factors to this increased susceptibility to infections are an opsonophagocytic defect due to an abnormality of the alternate pathway of complement activation, a state of functional hyposplenia, and a lack of specific circulating antibodies as a developmental phenomenon. If the inordinately high, early mortality rate associated with sickle cell anemia is to be prevented, early diagnosis of affected infants is crucial. Prophylactic therapy with penicillin has been advocated in recognition of the fact that a majority of the causative organisms are sensitive to penicillin. However, no controlled studies have proved the effectiveness of such therapy. Immunization with broadly polyvalent vaccines against Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis may ultimately represent the most effective way to reduce the incidence of catastrophic infections.

Anemia, Sickle Cell↗
PubMed1977

Intraerythrocytic adaptation (2,3 DPG,P50) in thalassemia minor.

P50 and 2,3 DPG content of erythrocytes were determined in 25 patients with heterozygous beta thalassemia minor to assess the adaptive mechanisms to anemia. 2,3 DPG levels were appropriately elevated for the degree of anemia. However, P50 values were not proportionately increased. No correlations were noted between hemoglobin level, 2,3 DPG, or P50 and the presence of symptomatic complaints of fatigue or weakness in these heterozygous patients.

Diphosphoglyceric Acids↗
PubMed1976

Infectious mononucleosis. Epstein-Barr-virus shedding in saliva and the oropharynx.

In an examination of excretion patterns of Epstein-Barr virus in 104 throat washings from 20 patients with infectious mononucleosis we found that three persons regularly shed virus from the second week through the third month after onset; 15 demonstrated intermittent excretion over three months, and in two cases, no virus was detected. In oral secretions, the virus appeared to be located extracellularly. Transforming activity was demonstrated in aliquots after centrifugation and filtration, in a sample in which cells were disrupted before filtration, and in specimens after two years' storage. Multiple oropharyngeal sites were examined for presence of the virus. In one patient, virus was regularly demonstrated in throat washings and saliva; swabs from Stensen's duct orifices yielded virus in three of four cases. Demonstration of virus in these oropharyngeal specimens explains increased transmissibility in age groups in which salivary exchange is high.

Adolescent↗
PubMed1976

Chronic neurologic disturbance in childhood leukemia.

Twenty-three leukemic children were studied prospectively to detect chronic effects of therapy. All patients received CNS prophylaxis, including 2400 R cranial irradiation, and intermittent maintenance therapy with intravenous methotrexate, cyclophosphamide and cytosine arabinoside. Neurologic symptoms were observed in 12 patients, all of whom had intermittent limping and mild incoordination, between the 10th and 18th month of maintenance therapy. Five of the 12 sustained seizures and four of these had subsequent abnormalities in motor, perceptual, behavioral or language development. Three school-aged children have learning disability and perceptual-motor defects. Studies of CSF folate and MTX content are presented but not helpful in delineating the etiology of these neurologic symptoms.

Adolescent↗
PubMed1976

Prospective study of sickle cell anemia in infancy.

Twelve infants with sickle cell anemia identified in the course of a cord blood screening program have been followed prospectively for up to three years of age. The development of hemolytic anemia paralleled the postnatal decline in fetal hemoglobin and was evident in all infants by 12 weeks of age. Vasoocclusive episodes occurred in more than half the infants and seven aplastic crises were documented in four patients. Febrile illnesses were common and one of the twelve infants developed pneumococcal sepsis. This study also demonstrated that functional asplenia is an acquired defect in sickle cell disease. The onset of functional asplenia was documented with splenic scans in six of the nine infants followed for more than one year after birth. There have been no deaths in this series.

Anemia, Aplastic↗
PubMed1975

The spleen as a hematological organ.

The spleen has multiple roles in human physiology. Eitht major functions are discussed in this review (hematopoiesis, erythrocyte destruction, hormonal function in hematopoiesis, culling and pitting, platelet and leukocyte destruction, particulate removal, reservoir function, and immunologic function). Splenic trapping of red cells, and the concepts of hypersplenism, are major responsibilities of this organ. These aspects are placed in perspective for the reader.

Anemia, Hemolytic↗