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Biomedical subjects

H A Britton

Publications and source records attributed to H A Britton.

At least 19 recordsLinked to original sources
PubMed2001

Use of recombinant factor VIIa (NovoSeven) in patients with Glanzmann thrombasthenia.

Recombinant factor VIIa (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) appears effective and relatively safe for the treatment of bleeding and for surgical prophylaxis in patients with Glanzmann thrombasthenia as reported to the International Registry on rFVIIa and Congenital Platelet Disorders. One of the shortcomings of the Registry data is the heterogeneity of treatment protocol, including dosage, number of doses used, duration of treatment before declaration of failure, and mode of rFVIIa administration (bolus v continuous infusion). The data are not yet sufficient to define optimal regimens for various indications such as the type of bleeding or the type of procedures. The place of this drug compared to platelet transfusion in the overall management of patients with Glanzmann thrombasthenia will need to be determined in relationship to a number of challenges and unresolved issues in the clinical care of these patients. These issues include: how to improve local measures for patients with mucosal bleeds, optimal management of young women during menarche, optimal platelet transfusion regimens for various indications, the relationship between antiplatelet antibodies detected by monoclonal antibody-specific immobilization of platelet antigens (MAIPA) and effectiveness of platelet transfusion, whether there are other biological tests that may correlate with effectiveness of platelet transfusion, and management of pregnancy and delivery regarding antiplatelet immunization.

Coagulants↗
PubMed1998

The clinical spectrum in a large kindred with autoimmune lymphoproliferative syndrome caused by a Fas mutation that impairs lymphocyte apoptosis.

Autoimmune lymphoproliferative syndrome (ALPS) is characterized by chronic, histologically benign splenomegaly and generalized lymphadenopathy, hypergammaglobulinemia, and autoantibody formation. ALPS has been attributed to defective programmed cell death of lymphocytes, most often arising as a result of mutations in the gene encoding the lymphocyte apoptosis receptor Fas/APO-l/CD95. We identified a novel mutation in the intracellular apoptosis signaling domain of Fas in 11 members of a family, individual members of which have been monitored for up to 25 years, with 1 or more features of ALPS. This study of a large number of family members carrying the same Fas defect demonstrates that ALPS is inherited in an autosomal dominant fashion but with a high degree of variability in clinical expression. Although 1 affected individual died of postsplenectomy sepsis and 1 has been treated for lymphoma, the Fas mutation in this family has been compatible with a healthy adulthood, as clinical features of ALPS have receded with increasing age.

Adolescent↗
PubMed1998

Symptomatic splenic hamartoma: case report and literature review.

An 11-year-old girl with low-grade fever, night sweats, thrombocytopenia, and an 8-year history of progressive splenomegaly underwent an elective splenectomy. Pathologic diagnosis was multiple splenic hamartoma. The patient's symptoms resolved after the splenectomy. Since first described by Rokitansky in 1861, approximately 140 cases of splenic hamartoma have been described in the literature. Most of the splenic hamartomas were discovered incidentally. A minority of these lesions were associated with hematologic symptoms such as pancytopenia, anemia, and thrombocytopenia. Only 20 of the reported cases of splenic hamartoma occurred in pediatric patients. However, compared with the adult patients, nearly half of these cases in pediatric patients was associated with symptoms. Splenectomy and partial splenectomy have relieved these symptoms. With advances in imaging, splenic hamartomas are being discovered with increasing frequency. A multimodal radiologic work-up has enabled some cases of splenic hamartoma to be diagnosed preoperatively. Inclusion of this benign entity in the differential diagnoses of symptomatic splenomegaly in a pediatric patient is important in the preoperative management and counseling of the patient and family. In patients who have discrete lesions, consideration of this entity preoperatively may avoid total splenectomy.

Adult↗
PubMed1997

Glucosephosphate isomerase (GPI) deficiency mutations associated with hereditary nonspherocytic hemolytic anemia (HNSHA).

Five unrelated patients with hereditary glucosephosphate isomerase (GPI) deficiency resulting in nonspherocytic hemolytic anemia were studied. Three new mutations were found in the coding region of the GPI gene: two patients were heterozygous for 223 A-->G (R75G) and 898 G-->C(R300P), respectively and one was homozygous for 1415G-->A(R472H). Surprisingly, 2 previously reported mutations, 286 C-->T and 1039 C-->T, were found in 2 and 3 patients respectively. Until now only 4 of 18 GPI mutations had been found more than once in unrelated patients and these 4 in only 2 patients each. Eleven of the 20 known point mutations have occurred at CpG "hot spots" and the 286 C-->T and 1039 C-->T are among these. The 489 G/A polymorphism in the GPI coding region was used to demonstrate unequivocally that the 1039 C-->T mutation occurred in both haplotypes and therefore probably originated more than once. Because no common GPI mutation has been found we suggest that heterozygosity for GPI confers little if any selective advantage.

Adult↗
PubMed1989

Disseminated primitive neuroectodermal tumor: diagnosis using immunocytochemistry, electron microscopy, and molecular probes.

A patient with a disseminated small cell tumor presented with hyperuricemia, gingival hypertrophy, lymphadenopathy, and bone marrow replacement with tumor cells. Initial histologic examination and clinical presentation were consistent with presumed marker silent lymphoma/leukemia. Despite initial treatment with and response to lymphoma/leukemia therapy the patient relapsed in the testis, bone marrow, pancreas, and skin whereupon subsequent and retrospective immunocytochemical, ultrastructural, cytogenetic, and molecular analysis led to the diagnosis of primitive neuroectodermal tumor (PNET). Despite extensive investigation and autopsy no primary site of tumor could be found demonstrating that PNET should be considered in the differential diagnosis of disseminated small cell tumors without an apparent primary.

Adolescent↗
PubMed1987

Loss of hepatitis B antibody in human immunodeficiency virus-positive hemophilia patients.

The presence of human immunodeficiency virus (HIV) antibody in hemophilia patients was correlated with the loss of existing antibody to hepatitis B surface antigen (HBsAb) or the inability to develop an antibody to hepatitis B after receiving commercially available hepatitis B vaccine. Of the 137 patients studied 66 were HIV-positive and 71 were HIV-negative. Evidence of HBsAb (n = 44) or exposure to hepatitis vaccine (n = 12) was found in 85% of HIV positive patients at some time during their care in our clinic. However, 20% demonstrated subsequent antibody loss and/or did not respond to hepatitis vaccine. Loss of HBsAb or vaccine nonresponse was restricted to patients less than 21 years of age (72% of all patients). This result contrasted to only a 3% loss of HBsAb or vaccine nonresponse in the HIV-negative patients who had acquired the HBsAb (n = 23) or were given the hepatitis vaccine (n = 29). This result suggests that loss or alterations of hepatitis B immunity occur in association with HIV infection or exposure.

Child↗
PubMed1985

Massive metastatic pulmonary calcification in an infant with aleukemic monocytic leukemia.

An 18-month-old infant with aleukemic monocytic leukemia and osteoclastic bone resorption demonstrated in the pelvis, vertebral bodies, and ribs developed severe refractory hypercalcemia. Bilateral interstitial pulmonary radiopacities developed rapidly, accompanied by hypoxemia and hypercapnea. Von Kossa staining of an open lung biopsy revealed extensive, finely granular metastatic septal calcifications not apparent on H&E-stained sections. Autopsy revealed the massive nature of the pulmonary calcinosis and the presence of additional calcifications in the atrial subendocardium, liver, kidneys, vessels, and skin. Metastatic pulmonary calcification has been infrequently described in infants, and premortem detection of such deposits has been rarely reported. The Von Kossa stain is useful in detecting minute pulmonary calcifications which may radiographically simulate infiltrates of infectious origin.

Biopsy↗
PubMed1981

Pneumococcal vaccine failures. Two case reports and review.

In six patients (four described previously) who received the currently licensed pneumococcal vaccine (Pneumovax), severe pneumococcal disease developed from a type contained in the vaccine. All exhibited a poor or inconsistent antibody response to the vaccine. Immunosuppressive drugs and radiation used to treat existing disorders, predominantly Hodgkin's disease, appeared to be major factors responsible for the poor immune response. None were receiving antimicrobial prophylaxis at the time of the pneumococcal infection. We suggest that type-specific antibody at a level below 215 ng of antibody nitrogen per milliliter of serum may not be protective. More extensive vaccine trials in persons, particularly children, at high risk of severe pneumococcal disease are needed. The optimal time to immunize persons receiving radiation or immunosuppressive drugs remains to be established.

Adolescent↗
PubMed1976

Severe combined immunodeficiency with cartilage-hair hypoplasa: in vitro response to thymosin and attempted reconstitution.

The present report describes an infant with severe combined immunodeficiency and cartilage-hair hypoplasia whose lymphocytes responded to thymosin in vitro. Immunologic evaluation was undertaken at 4 1/2 months of age following a history of recurrent severe infection. Family history included three cousins who died in early infancy, one from streptococcal meningitis and pneumonia, one from generalized varicella, and another from reticuloendotheliosis. Quantitative immunoglobulins were markedly depressed: IgG 141, IgA 0, and IgM 24 mg/100 ml. There was an absolute lymphopenia, multiple skin tests were negative, and in vitro lymphocyte responses to mitogens and antigens were depressed. Spontaneous E rosette determinations were 21% compared with control values of 65.7%. Erythrocyte adenosine deaminase (ADA) activity was normal. The patient's E rosette formation increased in the presence of thymosin, fraction 5, reaching a maximum of 56% with a concentration of 500 mug thymosin. Blastogenic responses to phytohemagglutinin also increased in the presence of thymosin. Transplantation of 24-week fetal thymus in Millipore diffusion chambers and subsequently transplantation of 18-week fetal thymus by intraperitoneal injection was accomplished. E rosettes increased to 35-40% and blastogenic responses to mitogens increased. Eight days after the second transplant the patient underwent a mild graft vs. host reaction which subsided after 1 week and mitogen blastogenic responses again increased to 5-8 times previous values, but still well below control ranges. Repeated episodes of pulmonary infection ensued, cor pulmonale resulted, and the clinical course was relentlessly downhill with the patient expiring from respiratory failure 5 months after transplantation.

Cartilage↗
PubMed1975

Three dose regimens of adriamycin for induction of remission in acute leukemia in children: a Southwest Oncology Group Study.

Three therapeutic regimens (6-hr intervals for 6 doses daily for 3 days, and a single infusion) utilizing the same total dose of adriamycin for the induction of remission in children with late-stage acute leukemia were evaluated in 150 patients. Complete remission rates were 15%, 28%, and 25%, respectively. Twenty-five children who achieved complete bone marrow remissions with adriamycin therapy were treated a second time after subsequent relapses. Of these children 20% achieved second bone marrow remissions.

Acute Disease↗