Search PubMed⌕ Search

Biomedical subjects

L D Wadsworth

Publications and source records attributed to L D Wadsworth.

At least 19 recordsLinked to original sources
PubMed2006

Anti-basal ganglia antibodies and acute movement disorder following herpes zoster and streptococcal infections.

Anti-basal ganglia antibodies (ABGA) have been associated with poststreptococcal encephalitis similar to encephalitis lethargica (EL). We report two children with parainfectious encephalitis of similar phenotype and IgG ABGA. However, the associated pathogens in the two cases differed; beta-hemolytic streptococcus and herpes zoster. ABGA may not be specific to poststreptococcal encephalitis, but rather a surrogate marker of an inflammatory mediated movement disorder, which may respond to immunotherapy.

Adolescent↗
PubMed1999

A population-based study of childhood myelodysplastic syndrome in British Columbia, Canada.

Myelodysplastic syndrome (MDS) is considered to be very rare in children. However, the only two published population-based studies reported widely divergent incidence figures. To further explore the epidemiology of childhood MDS and to evaluate the accuracy of cancer registry and treatment trial data, we conducted a population-based study of children aged 0-14 years in British Columbia (BC), Canada, between 1982 and 1996. MDS was diagnosed in 31 cases corresponding to an annual incidence of 3.2 per million children or 6% of all leukaemias, compared with an incidence of 6.0/million for acute myeloid leukaemia (AML), and of 0.5/million for chronic myeloid leukaemia. There was a non-significant (P = 0.19) trend toward an increase in MDS incidence with time, the increase was partly explained by an increasing number of patients with Down syndrome. Associated abnormalities were found in 48% of the MDS cases with Down syndrome as the most common (seven cases). Only one third of the MDS cases were correctly registered in the Cancer Registry and less than half of the eligible MDS patients were enrolled on a cooperative group study. Data on MDS from treatment-based studies and cancer registries were inaccurate and seemed to significantly underestimate the incidence of MDS in children.

Adolescent↗
PubMed1998

The use of acute hemodilution in parturients undergoing cesarean section.

OBJECTIVE: Concern over transmissible disease has increased interest in methods of minimizing homologous blood transfusion during elective surgery. One method is acute hemodilution, a technique previously unreported in parturients. This study was designed to determine its feasibility and safety in women at risk of hemorrhage during cesarean section. STUDY DESIGN: This technique was performed on 38 parturients. Collected blood was retransfused at the end of surgery or earlier, if required. Hemoglobin was measured before hemodilution, after hemodilution, before transfusion, after transfusion, and 24 hours postoperatively. Neonatal assessment included umbilical blood gases and Apgar scores. RESULTS: All patients were hemodynamically stable and no fetal heart rate abnormalities were observed during the procedure. One patient received homologous blood and 14 received previously donated autologous blood. Umbilical blood gases were normal and 5-minute Apgar scores were > or = 7. CONCLUSION: This study suggests that acute hemodilution is well tolerated in parturients undergoing cesarean section. This may limit exposure to homologous blood transfusion.

Adult↗
PubMed1998

Recombinant human erythropoietin for treatment of anemia of chronic disease in children with Crohn's disease.

We evaluated the efficacy and safety of and compliance with rH-EPO (150 U/kg three times a week subcutaneously for up to 12 weeks) for treatment of anemia in childhood Crohn's disease (n = 4). The mean hemoglobin level before rH-EPO therapy was 109 gm/L (10.9 gm/dl) (range, 103 to 115 gm/L). The mean hemoglobin level in the three compliant children increased to 138 gm/L (13.8 gm/dl) after treatment. Response time for the correction of anemia ranged from 6 to 12 weeks (mean, 9.5 weeks). Resolution of symptoms of lethargy, poor appetite, and irritability occurred with correction of the anemia. The only adverse effect observed was transient local pain at the injection site.

Adolescent↗
PubMed1997

Thrombotic thrombocytopenic purpura: a treatable cause of childhood encephalopathy.

We describe two patients less than 13 years of age with thrombotic thrombocytopenic purpura, a rare disorder in childhood. Both children were treated with plasma exchange therapy, which resulted in a rapid resolution of symptoms. This disorder is a cause of childhood encephalopathy, which can be treated effectively with plasma exchange.

Brain Diseases↗
PubMed1997

A new method for characterization and epitope determination of a lupus anticoagulant-associated neutralizing antiprothrombin antibody.

A patient had both lupus anticoagulant hypoprothrombinemia syndrome and celiac disease. The presence of a neutralizing antiprothrombin antibody in the patient's serum was demonstrated by coagulation tests, immunoadsorption, and Western blot analysis. The probable cause for the severe hypoprothrombinemia was clearance of prothrombin-antibody complexes from the circulation. Studies showed the antiprothrombin antibody binding to human prothrombin was phospholipid- and Ca(++)-independent; the antibody did not bind to human thrombin. The target epitope of the antibody was studied by Western blot analysis of mutated recombinant human prothrombin molecules. The antibody reacted with the fragment 2-A region of prothrombin, spanning the second kringle domain and the thrombin A chain within prothrombin. Based on this new method, the proposed mechanism for the neutralizing action of the antibody is impairment of prothrombin activation by the prothrombinase complex, either by steric hindrance of the hydrolysis of prothrombin by factor Xa or by interference of the interaction of prothrombin with factor Va; both reactions are required for efficient conversion of prothrombin to thrombin.

Blotting, Western↗
PubMed1996

Transient erythroporphyria of infancy.

We describe a neonate with hemolytic disease of the newborn in whom a photosensitivity eruption developed during phototherapy for treatment of hyperbilirubinemia. Free erythrocyte protoporphyrin and zinc protoporphyrin levels were markedly elevated during the neonatal period. Porphyrin levels were normal at 19 weeks of age. The infant had residual skin atrophy and showed clinical and radiologic evidence of kernicterus. The pathogenesis of transient porphyrinemia associated with hemolytic disease of the newborn is unclear.

Humans↗
PubMed1995

The role of autologous blood transfusion in adolescents undergoing spinal surgery.

STUDY DESIGN: A prospective study of 147 consecutive patients undergoing spinal surgery who were analyzed for response to an effect of an offered autologous blood program. OBJECTIVES: Analysis of the impact of the autologous program within a comprehensive blood conservation philosophy toward the reduction in the use of homologous blood. METHODS: Each patient was prescreened by the autologous program for inclusions and ability. Physical parameters were recorded as were predonation and postdonation hemoglobin levels. The volume of each donation and the number of autologous and homologous units transfused and total operating blood loss were recorded as were complications during donation and transfusion. RESULTS: One hundred sixteen of the original one hundred forty-seven patients participated in the program and donated between 150 and 1900 ml of blood during the preoperative period. Of these, 35 patients weighed 45 kg or less. Diagnoses included 97 cases of idiopathic scoliosis and the remainder had spinal deformities of other causes. Of the entire group, 13 patients (11%) received homologous blood transfusion, 7 of these patients had diagnoses other than idiopathic scoliosis. CONCLUSIONS: In this study of 116 patients, 89% of the spinal surgeries were successfully completed using only autologous blood. This compared favorably with a historical control group in which 60% of the patients required homologous blood transfusion. It is concluded that the use of autologous blood donation combined with other blood conservation techniques has significantly lessened the need for homologous transfusion.

Adolescent↗
PubMed1994

Reappraisal of optimal hemoglobin standards for female blood donors in Canada.

BACKGROUND: A hemoglobin (Hb) standard of 115 g per L on the copper sulfate test has been in use by the Canadian Red Cross Society Blood Services for female blood donor predonation screening since 1989. STUDY DESIGN AND METHODS: To determine if this lowered Hb standard results in increased iron deficiency in repeat blood donors, a study was conducted to evaluate the performance of the copper sulfate test and predonation capillary and venous Hb assays in a population of female blood donors most at risk of developing iron deficiency. RESULTS: Of the 174 donors who were of childbearing age, who were not taking iron supplements, and who had made at least three blood donations per year, 45 (25.9%) were iron deficient, and 64 (36.8%) had reduced iron stores; only 65 (37.3%) had normal iron stores. This study showed that capillary blood is more likely to have a higher Hb concentration (3.2 +/- 7.8 g/L) than venous blood samples, which could affect the performance of predonation screening assays that are based on capillary blood samples at a given discriminating value. With an Hb standard of 115 g per L, both the copper sulfate and capillary Hb assays were not sensitive enough to screen for iron deficiency (sensitivity, 27% and 33%; specificity, 96% and 93%, respectively) and were comparable only to the performance of a venous Hb assay with a cutoff value of 110 g per L (sensitivity, 27%; specificity, 99%). In contrast, an Hb standard of 125 g per L in the copper sulfate test could achieve a more optimal sensitivity of 79 percent and specificity of 78 percent. CONCLUSION: This study supports the use of a higher Hb cutoff value of 125 g per L for female blood donors in the predonation fingerstick copper sulfate test.

Adult↗
PubMed1992

Primary hemochromatosis in children: report of three newly diagnosed cases and review of the pediatric literature.

Hereditary hemochromatosis was diagnosed in three asymptomatic siblings following the unexpected finding of elevated serum iron concentrations. This diagnosis was confirmed by hepatic biopsy. Repeated phlebotomies resulted in a significant decline of serum iron and ferritin concentrations and a decrease of hepatic iron content. This report and a review of the literature indicate that the diagnosis of hereditary hemochromatosis must be considered more frequently in childhood. Organ dysfunction from iron overload may be minimized in children by the early commencement of regular phlebotomy.

Child↗
PubMed1992

Autologous blood transfusion for pediatric bone marrow donors.

Nine normal bone marrow donors aged 7-166 months (median 69 months) received autologous red cells which had been removed from their marrow harvest after collection. The median volume of marrow removed from the donors was 18.6 ml/kg which was equivalent to a median blood volume loss of 23.3%. Three infant donors were transfused with autologous red blood cells intraoperatively. These cells had been salvaged from the initial marrow aliquot and were transfused while bone marrow harvesting continued. No donors required homologous blood transfusion. This technique is useful for marrow donors in the pediatric age group when preharvest autologous blood collection is not feasible or available.

Adolescent↗
PubMed1992

Delayed delivery of second twin: report of four cases and review of the literature.

In four cases of delayed delivery of a twin pregnancy with survival of the second twin, the interval ranged at 41-143 days. Review of the literature and our cases supports the following approach: high ligation of the umbilical cord with an absorbable suture, cervical suture in the presence of cervical dilatation, and serial monitoring of fetal growth and maternal coagulation indices. Disseminated intravascular coagulation has not been reported in such cases.

Delivery, Obstetric↗
PubMed1991

Transcobalamin II deficiency: case report and review of the literature.

A male Caucasian infant presented at 6 weeks of age with failure to thrive, diarrhoea, macrocytic anaemia, and decreased IgG. He had normal serum B12 and folate levels. Serum cobalamin binding capacity showed no detectable transcobalamin II. Both parents showed levels consistent with a heterozygous state. The literature is extensively reviewed, and the importance of early diagnosis to prevent neurological dysfunction is stressed.

Failure to Thrive↗
PubMed1991

The usefulness of sequence analysis of amplified DNA for the identification of delta chain variants.

A method of identifying delta chain variants using relatively small volumes of blood is described. The procedure consists of the amplification of two segments of genomic DNA with two sets of delta chain specific primers and sequencing of the three exons (exons 1, 2, and 3) which are part of the amplified DNA segments. Data for three delta chain variants present in seven adult heterozygotes are presented.

Adult↗
PubMed1991

ABO-incompatible pediatric bone marrow transplantation: a simple method to remove red blood cells from small volume marrow grafts.

A simple and reliable technique for removal of ABO incompatible marrow red cells is described. This method requires a blood cell processor and third party red cells are used as a shelf. Using this technique, nine children age 0.5-11.5 years received allogeneic bone marrow transplantation from ABO incompatible donors. A median of 4.8 ml of incompatible red cells were transfused. There was no evidence of a hemolytic transfusion reaction in any patient. A median of 75% of nucleated marrow cells were recovered and used for transplantation. Engraftment occurred at the same time as with ABO compatible transplants. Autologous marrow red cells were reinfused into four young donors. This 'shelf' technique for red cell depletion is an acceptable method for processing small volume, ABO incompatible marrow harvests from pediatric donors.

ABO Blood-Group System↗