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D L Wethers

Publications and source records attributed to D L Wethers.

16 recordsLinked to original sources
PubMed1996

Serotype-specific immunoglobulin G antibody responses to pneumococcal polysaccharide vaccine in children with sickle cell anemia: effects of continued penicillin prophylaxis.

OBJECTIVES: (1) To determine serotype-specific IgG antibody responses to reimmunization with pneumococcal polysaccharide vaccine at age 5 years in children with sickle cell anemia and (2) to determine whether continued penicillin prophylaxis had any adverse effects on these responses. STUDY DESIGN: Children with sickle cell anemia, who had been treated with prophylactic penicillin for at least 2 years before their fifth birthday, were randomly selected at age 5 years to continue penicillin prophylaxis or to receive placebo treatment. These children had been immunized once or twice in early childhood with pneumococcal polysaccharide vaccine and were reimmunized at the time of randomization. RESULTS: Serotype-specific IgG antibody responses to reimmunization varied according to pneumococcal serotype but in general were mediocre or poor; the poorest response was to serotype 6B. The antibody responses were similar in subjects with continued penicillin prophylaxis or placebo treatment, and in subjects who received one or two pneumococcal vaccinations before reimmunization. The occurrence of pneumococcal bacteremia was associated with low IgG antibody concentrations to the infecting serotype. CONCLUSIONS: Reimmunization of children with sickle cell anemia who received pneumococcal polysaccharide vaccine at age 5 years induces limited production of serotype-specific IgG antibodies, regardless of previous pneumococcal vaccine history. Continued penicillin prophylaxis does not interfere with serotype-specific IgG antibody responses to reimmunization.

Adult↗
PubMed1995

Functional asplenia in hemoglobin SC disease.

The incidence of functional asplenia in sickle-hemoglobin C (SC) disease has not been defined, and the use of prophylactic penicillin to prevent life-threatening septicemia in this disorder is controversial. The percentage of red blood cells with pits (pit count) is a reliable assay of splenic function in other disorders but has not been validated in hemoglobin SC disease. To address these issues, we conducted a prospective, multicenter study of splenic function in persons with hemoglobin SC disease. Baseline clinical data were recorded, and red blood cell pit counts were performed on 201 subjects, aged 6 months to 90 years, with hemoglobin SC; 43 subjects underwent radionuclide liver-spleen scanning. Pit counts greater than 20% were associated with functional asplenia as assessed by liver-spleen scan, whereas pit counts less than 20% were found in subjects with preserved splenic function. Pit counts greater than 20% were present in 0 of 59 subjects (0%) less than 4 years of age, in 19 of 86 subjects (22%) 4 to 12 years of age, and in 25 of 56 subjects (45%) greater than 12 years of age. Other subjects with hemoglobin SC, who had previously undergone surgical splenectomy, had higher pit counts (59.7% +/- 9.5%) than splenectomized subjects without hemoglobinopathy (38.5% +/- 8.8%) or with sickle cell anemia (20.5% +/- 1.9%; P < .001). Two subjects with hemoglobin SC disease (not splenectomized), ages 14 and 15 years, with pit counts of 40.3% and 41.7% died from pneumococcal septicemia. These data indicate that functional asplenia occurs in many patients with hemoglobin SC disease, but its development is usually delayed until after 4 years of age. The pit count is a reliable measure of splenic function in hemoglobin SC disease, but values indicative of functional asplenia (> 20% in our laboratory) are higher than in other disorders. The routine administration of prophylactic penicillin to infants and young children with hemoglobin SC disease may not be necessary.

Adolescent↗
PubMed1994

Accelerated healing of chronic sickle-cell leg ulcers treated with RGD peptide matrix. RGD Study Group.

Leg ulcers are a chronic manifestation of sickle-cell disease (SCD) and are often painful, disabling, and difficult to treat. RGD peptide matrix treatment is a novel therapy designed to provide a topical synthetic extracellular matrix that can act as a temporary substitute for the damaged natural matrix at the ulcer site. In this randomized, placebo-controlled, double-blind, prospective, multicenter investigation, SCD patients with full-thickness leg ulcers were treated with standard therapy plus RGD peptide matrix or saline placebo once weekly for up to 10 weeks. Healing in patients with chronic ulcers (2 months or greater in duration) was significantly accelerated (P = .0085) in RGD peptide matrix recipients compared with the placebo group. In these chronic ulcer cases, the average percent ulcer closure (decrease in ulcer surface area) in the RGD peptide matrix group (54.4% +/- 8.9%) exceeded that in the placebo group (19.0% +/- 24.3%) nearly threefold by study endpoint. Furthermore, RGD peptide matrix was equally effective in promoting healing of long persistent ulcers and ulcers of shorter duration. In contrast, standard therapy plus placebo was significantly less effective (P = .001) in promoting healing for ulcers of progressively greater duration. The results of this study provide preliminary evidence that RGD peptide matrix treatment may significantly accelerate healing of chronic sickle-cell leg ulcers.

Adolescent↗
PubMed1991

Febrile episodes in children with sickle cell disease treated on an ambulatory basis.

Children with sickle cell disease have a greatly increased potential for developing rapid and at times fatal sepsis from Streptococcus pneumoniae. Hospitalization and parenteral antibiotic treatment in all febrile children with sickle cell disease have thus become the standard of care at most sickle cell centers. As an alternative approach, we managed selected febrile children with sickle cell disease on an ambulatory basis with parenteral ceftriaxone to determine its safety and effectiveness in preventing sepsis and reducing the number of days of hospitalization. Twenty of 40 children who presented with significant fever met the study criteria and received ceftriaxone on an ambulatory basis. Three were subsequently hospitalized. Compared with a previous year, when all febrile children were admitted, ceftriaxone use reduced the days of hospitalization from 214 (6.3 +/- 1.6 days/patient) to 111 days (2.8 +/- 0.7 days/patient). The empiric use of ceftriaxone appears safe and effective, but it requires an expanded study over an extended period.

Adolescent↗
PubMed1990

Management of acute splenic sequestration crisis in sickle cell disease.

Acute splenic sequestration crisis (ASSC) is a significant cause of early morbidity in children with sickle cell disease. With timely diagnosis and prompt transfusion, the outcome is good. However, recurrences are frequent, and both splenectomy and long-term transfusion therapy have been advanced as appropriate preventive approaches. We describe the diagnosis, management, and course of 15 patients with ASSC followed at the St. Luke's-Roosevelt Hospital Center Comprehensive Sickle Cell Program. Based on our experience, we recommend surgery after the first episode of ASSC in the child 5 years of age and older and the choice of a year or more of long-term transfusion therapy for the child under 3. With intensive education of the parents, and with close observation and individualized management of the patient, the overall prognosis may be improved.

Acute Disease↗
PubMed1988

Spleen dysfunction in hemoglobinopathies determined by pitted red cells.

Splenic dysfunction measured by pitted red cells (pit) was studied in hemoglobinopathies (SS-, SC-, and S beta-type thalassemias and CC-type hemoglobinopathy) in relation to age, in steady state, and during certain significant events. Our experience revealed that the pit count rose with age during steady state in most children with SS disease. A marked increase in pit count was noted in patients with CC disease. The pit count in four patients with S beta+ thalassemia remained normal (i.e., less than 3.5%) at all ages. In children with homozygous SS disease tested at the time of pneumococcal sepsis, the pit count was universally elevated. The pit count was in the normal range in one child with SS disease and osteomyelitis but was elevated in all others. All children had normal pit counts (less than 3.5%) at the onset of acute splenic sequestration crisis, and the counts remained normal during transfusion therapy. No correlation was detected between the pit count and the size of the spleen in patients under 1 year of age.

Adolescent↗
PubMed1987

Growth hormone response to growth hormone releasing factor in sickle cell disease.

Many children with sickle cell disease (SCD) have impaired growth during childhood and adolescence, with patterns of growth consistent with constitutional delay in growth and pubertal development (CDGD). We evaluated the growth hormone (GH) response to a rapid intravenous (i.v.) infusion of growth hormone releasing factor (GRF, 1-44, 1 microgram/kg) in six children with SCD whose growth patterns and bone ages were consistent with CDGD. The peak GH response of the SCD patients to GRF (29.2 +/- 14.3 ng/ml, mean +/- SD, n = 6) was not statistically significantly different from the peak GH response of the control children (29.0 +/- 6.3 ng/ml, mean +/- SD, n = 7). These findings suggest that pituicyte GH response to GRF is intact and is not the cause of the observed impaired growth in patients with SCD.

Adolescent↗
PubMed1987

Reversibility of splenic function by transfusion in two young adults with sickle cell anemia.

A level of circulating "pitted" or vesiculated red blood cells higher than 3.5% was recently reported in studies in the Cooperative Study of Sickle Cell Disease to correlate with splenic dysfunction as shown by spleen scans. Reversal of splenic dysfunction by transfusion in children with sickle cell anemia (SS disease) is known to occur in the young child. We report two older patients with homozygous sickle cell disease, aged 17 and 21 years, whose spleen function, as measured by pit count, was restored to normal range after transfusion.

Adolescent↗
PubMed1983

Pitfalls in diagnosis of osteomyelitis in children with sickle cell disease.

The cases of three children with unusual features of osteomyelitis and sickle cell disease are presented. Two children had salmonella osteomyelitis, one with a recurrence 1.5 years after adequate intravenous therapy. In the second, the bone scan was negative despite verified disease. The causative organism in the third case was Staphylococcus aureus, and there was extensive bone involvement of the radius without symptoms, but with a positive bone scan. It is recommended that the possibility of osteomyelitis be entertained in a child with sickle cell disease whenever there are symptoms and/or objective findings referrable to bone. Radionuclide scans, when used in timely fashion, can assist in the diagnosis, but confirmation can best be achieved by the recovery of microorganisms through blood culture and/or bone aspirate. The choice, dosage, and duration of antibiotic therapy should be determined by causative organisms and by serologic titers.

Anemia, Sickle Cell↗
PubMed1982

Problems and complications in the adolescent with sickle cell disease.

The period of adolescence in the patient with sickle cell disease seems to be a period of relative calm, medically speaking. The current 5-year prospective Cooperative Study of the Clinical Course of Sickle Cell Disease should demonstrate the actual spectrum of disease in this age group. The recent literature documents with significant relationship between retardation of growth and sexual maturation in the child with sickle cell disease, an effect which seems independent of the severity of the disease. Several other major problems in the adolescent are discussed, including psychological disturbances, leg ulcers, aseptic necrosis, pulmonary disease, priapism, stroke, cholelithiasis, and birth control. A retrospective series of 76 cases of sickle cell disease is briefly presented and the complication occurring during the second decade of life are reviewed.

Adolescent↗