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Biomedical subjects

F M Gill

Publications and source records attributed to F M Gill.

At least 19 recordsLinked to original sources

Cerebrovascular accidents in sickle cell disease: rates and risk factors.

Cerebrovascular accident (CVA) is a major complication of sickle cell disease. The incidence and mortality of and risk factors for CVA in sickle cell disease patients in the United States have been reported only in small patient samples. The Cooperative Study of Sickle Cell Disease collected clinical data on 4,082 sickle cell disease patients enrolled from 1978 to 1988. Patients were followed for an average of 5.2 +/- 2.0 years. Age-specific prevalence and incidence rates of CVA in patients with the common genotypes of sickle cell disease were determined, and the effects of hematologic and clinical events on the risk of CVA were analyzed. The highest rates of prevalence of CVA (4.01%) and incidence (0.61 per 100 patient-years) were in sickle cell anemia (SS) patients, but CVA occurred in all common genotypes. The incidence of infarctive CVA was lowest in SS patients 20 to 29 years of age and higher in children and older patients. Conversely, the incidence of hemorrhagic stroke in SS patients was highest among patients aged 20 to 29 years. Across all ages the mortality rate was 26% in the 2 weeks after hemorrhagic stroke. No deaths occurred after infarctive stroke. Risk factors for infarctive stroke included prior transient ischemic attack, low steady-state hemoglobin concentration and rate of and recent episode of acute chest syndrome, and elevated systolic blood pressure. Hemorrhagic stroke was associated with low steady-state hemoglobin and high leukocyte count.

Adolescent↗

Clinical events in the first decade in a cohort of infants with sickle cell disease. Cooperative Study of Sickle Cell Disease.

Within the Cooperative Study of Sickle Cell Disease, 694 infants with confirmed sickle cell disease were enrolled at less than 6 months of age. Information about the nature and frequency of complications was collected prospectively over a 10-year period. Painful crises and acute chest syndrome were the most common sickle cell-related events in homozygous sickle cell anemia (SS), hemoglobin SC disease (SC), and S beta thalassemia patients (overall incidence in SS patients of 32.4 and 24.5 cases per 100 person-years, respectively). Bacteremia occurred most frequently in SS children under 4 years of age and in SC patients less than 2 years of age. The mortality rate was low in this cohort compared with that found in previous reports. Twenty children, all with Hb SS, died (1.1 deaths per 100 person-years among SS patients). Infection, most commonly with Streptococcus pneumoniae and Hemophilus influenzae, caused 11 deaths. Two children died of splenic sequestration, 1 of cerebrovascular accident, and 6 of unclear causes. Two patients underwent cholecystectomies, and 17 underwent splenectomies after one or more splenic sequestration crises. The experience of this cohort should reflect closely the true clinical course of those children with Hb SS and Hb SC disease who are observed in sickle cell centers in the United States.

Anemia, Sickle Cell↗

Reference values and hematologic changes from birth to 5 years in patients with sickle cell disease. Cooperative Study of Sickle Cell Disease.

OBJECTIVE: To examine hematologic changes from birth to 5 years of age and establish hematologic reference values for infants and children with sickle cell disease. RESEARCH DESIGN: Prospective natural history study. SETTING: Nineteen pediatric sickle cell centers across the United States. PATIENTS: Six hundred ninety-four infants with sickle cell disease (sickle cell anemia, sickle cell-hemoglobin C disease, and sickle-beta-thalassemia) who were enrolled in the Cooperative Study of Sickle Cell Disease at younger than 6 months of age. Median follow-up time through 5 years of age was 4.1 years. MEASUREMENTS AND RESULTS: We present longitudinal analyses of total hemoglobin concentration, percent fetal hemoglobin values, mean corpuscular volumes, total bilirubin concentration, and red blood cell (RBC), "pocked" RBC, white blood cell, platelet, and reticulocyte counts. Anemia was apparent by 10 weeks of life in infants with sickle cell anemia (SS infants). This anemia was associated with a rising reticulocyte count consistent with a hemolytic process. The reticulocyte count of SS infants increased steadily, exceeding 12% at 5 years of age. The fetal hemoglobin concentration of SS infants declined more slowly than that of infants with sickle cell hemoglobin C disease (SC infants). Pocked RBC counts rose sharply after 6 months of age, and by 1 year, 28% of SS infants had abnormal counts, above 3.5%, indicating poor splenic function. At 3 years of age, 78% of SS patients and 32% of SC patients had abnormal pocked RBC counts. The SS patients with concurrent alpha-thalassemia had, after 6 months of age and throughout early childhood, a slightly higher mean total hemoglobin concentration and lower mean pocked RBC and reticulocyte counts than SS patients without alpha-thalassemia. The hematologic profile of SC infants more closely resembled that of normal black infants, but there was mild anemia (10.5 g/dL) and slightly elevated mean values for reticulocytes (3%) and fetal hemoglobin (3%) during early childhood.

Age Factors↗

The influence of infant and maternal sickle cell disease on birth outcome and neonatal course.

OBJECTIVE: To compare the influence of maternal hemoglobin phenotype as well as that of the infant on birth outcome and neonatal complications. RESEARCH DESIGN: Prospective, natural history study with retrospective chart review for neonatal complications. SETTING: Nineteen pediatric sickle cell centers across the United States. PATIENTS: Four hundred eighty infants with sickle cell disease (SCD) who were enrolled in the Cooperative Study of Sickle Cell Disease at less than 6 months of age, as well as a comparison cohort of 118 infants with sickle cell trait born to women with sickle cell anemia in the Cooperative Study. RESULTS: In the SCD cohort, overall rates of preterm (< 37 weeks), low-birth-weight (< 2500 g), and small-for-gestational age births were 9%, 10%, and 8%, respectively; no significant differences were found according to infant hemoglobin phenotype. Term births accounted for 59% of the infants with low birth weight, significantly higher than the 41% US rate for black low-birth-weight infants (P = .014). Expectant mothers with sickle cell anemia are 2.5 times more likely to bear newborns who are small for gestational age than are women with other types of sickle cell disease, sickle trait, or C-trait. The most common prepartum and neonatal complications in infants with SCD were jaundice (25%), fetal distress (13%), anemia (10%), and respiratory distress (6%). Complication rates did not differ significantly by hemoglobin phenotype in the infants with SCD, but infants born to women with sickle cell anemia had higher rates of jaundice (P < .0001). CONCLUSIONS: Rates of adverse birth outcomes and neonatal complications in infants with SCD are similar to the rates for normal infants, although preterm birth accounts for fewer of the low-birth-weight outcomes among newborns with SCD relative to US black newborns. The hemoglobin phenotype of infants with SCD does not influence birth outcome and neonatal course, but infants born to women with sickle cell anemia are at greater risk of preterm birth, low birth weight, being small for gestational age, and neonatal jaundice.

Anemia, Sickle Cell↗

Potential impact of linking an emergency department and hospital-affiliated clinics to immunize pre-school-age children.

OBJECTIVE: To determine whether the use of an urban pediatric emergency department (ED) to immunize pre-school-age children would result in an improvement in the percentage fully vaccinated by the end of the second year of life. DESIGN: A retrospective cohort study of two groups: (1) 100 consecutive children (ED group) enrolled at one of two hospital-affiliated primary care clinics were chosen from the ED patient logs if their second birthday occurred in the 12 months prior to November 1990; and (2) 91 age-matched control children (control group) were chosen at random from the same hospital-affiliated clinics' enrollment logs without regard to ED use. The health care provided during the first 2 years of life for each group was compared. RESULTS: The mean number of visits to the ED in the first 2 years of life by the ED group was significantly greater than that of the control group (2.9 [SD] +/- 2.5 vs 1.1 +/- 1.4; P < .001) during the first 2 years of life. In 67% of ED visits, children would have been well enough to receive a vaccination. Both groups had similar types and numbers of visits to the primary clinics. For example, the ED group had 10 +/- 5 visits by age 2 years compared with the control group, which had 9 +/- 4 visits. There was no significant difference in actual immunization percentages achieved in the clinic, with 62% of the ED group having received four diphtheria, pertussis, and tetanus vaccinations; three oral poliovirus vaccinations; and one measles, mumps, and rubella vaccination by age 2 compared with 69% of control children. There were more missed vaccination opportunities during clinic visits in the ED group (7.4 vs 4.6 per 100 clinic visits; P < .01). If immunizations were offered in the ED to those children who needed them, immunization percentages would have been increased an average of 20% compared with percentages achieved in the clinic alone. CONCLUSION: Routine vaccinations in the ED would significantly increase immunization percentages in children enrolled in two hospital-affiliated clinics. Close linkage and coordination between the ED and hospital-affiliated clinics may improve preventive health care in urban children who use EDs.

Child Health Services↗

Indigent children who are denied care in the emergency department.

We conducted a six-month prospective study of the diagnoses and outcomes of 588 children who were denied care in our emergency department under a new primary-care case management health system for 100,000 indigent patients. The mean patient age was 4.7 years (39% were less than 2 years old). The most common presenting complaints were colds, earaches, rash, vomiting, and diarrhea. Nine percent of children presented for trauma, and 10% had fever of more than 38.2 C. Follow-up was available from the primary care physician for 388 children (66%). Of the 60% of patients who kept their arranged appointment, 42% received antibiotics, 3% were referred for further evaluation, and two children were hospitalized. Follow-up was available from the parents for 125 children (21%). No follow-up information of any kind was available for 111 children (19%), and no follow-up regarding the health of the child was available for 265 children (45%). This last group included 10% with a chief complaint of trauma and 6% with temperature of more than 39 C. Forty-nine percent of patients in this group were less than 2 years old.

Appointments and Schedules↗

Nutritional factors and growth in children with sickle cell disease.

A study of growth and nutrition was conducted with 20 growth-retarded (GR) and 20 growth-normal (GN) preadolescent children with sickle cell disease (SCD). All children were matched for age, sex, hemoglobin disorder, and hematologic values. Ten normal children served as control subjects. Mean serum levels of retinol, retinol-binding protein, prealbumin, and zinc were significantly lower in the children with SCD than in normal children. Mean serum retinol and prealbumin levels were similar in the GR and GN sickle cell groups. Mean serum retinol-binding protein levels were lower in GR than in GN patients. Serum zinc levels, somatomedin C levels, and bone age were frequently abnormal in the patients with SCD, but these factors did not correlate with growth status. It was not possible to explain the poor growth in patients with SCD in this study solely on the basis of nutritional factors.

Anemia, Sickle Cell↗

Bacteremia in sickle hemoglobinopathies.

We analyzed 178 episodes of bacteremia that occurred during 13,771 patient-years of follow-up of 3451 patients with sickle hemoglobinopathies. Age-specific incidence rates of bacteremia were calculated for patients with sickle cell anemia (SS) and sickle cell-hemoglobin C (SC) disease. The incidence rate was highest among children with SS and SC younger than age 2 years. Children with SC showed an abrupt decrease after age 2 years, whereas children with SS had a gradual decline in rate from 2 to 6 years of age. The predominant pathogen in patients younger than 6 years was Streptococcus pneumoniae (66%); gram-negative organisms were responsible for 50% of bacteremias in patients 6 years and older. Urinary tract infection was present during 73% of Escherichia coli bacteremias, and 77% of Salmonella bacteremias were associated with osteomyelitis. In contrast, no focus of infection was present in 52% of pneumococcal bacteremias. The incidence of pneumococcal bacteremia in children with SS younger than age 3 years was 6.1 events/100 patient-years; the case fatality rate for pneumococcal sepsis in this age group was 24%. No hematologic or demographic variables were associated with occurrence of pneumococcal bacteremia in young children. Retrospective analysis of pneumococcal bacteremia suggests that the prophylactic use of penicillin may decrease the incidence in children younger than 3 years of age.

Anemia, Sickle Cell↗

Acute chest syndrome in sickle cell disease: etiology and clinical correlates.

Acute chest syndrome (ACS) is a new pulmonic process in a clinically ill patient with sickle cell disease. We prospectively analyzed 102 episodes of ACS in patients in our hospital during a 2-year period to study cause and clinical correlates. In 12% of the episodes, ACS was judged to be secondary to bacterial pneumonia (including only 3% secondary to Streptococcus pneumoniae), 8% was associated with uncomplicated viral pneumonias, and 16% with mycoplasmal pneumonias. The clinical course and seasonal variations in these groups were compared with those in the remaining 64% of episodes. In comparison with episodes of ACS of undetermined origin (presumably secondary to pulmonary infarct, atelectasis, or missed infections), patients with bacterial pneumonia were sicker, as shown by fever and hospitalization of longer duration, the percent of those requiring red blood cell transfusion, and the presence of pleural effusions. The lower incidence of bacterial pneumonias among our patients compared with that previously reported may reflect our use of penicillin prophylaxis and pneumococcal immunization to prevent S. pneumoniae infections.

Acute Disease↗

Congenital bleeding disorders: hemophilia and von Willebrand's disease.

Treatment of hemophilia and von Willebrand's disease has become easier in recent years because of the development of more effective factor replacement products. The median age and the life expectancy of patients with hemophilia have risen markedly, as has the median age at death.

Acquired Immunodeficiency Syndrome↗

Inhibitor treatment using unactivated prothrombin complex concentrates: the Pennsylvania experience--1978-1982.

Data were analyzed on 48 patients with Factor VIII:C inhibitors, 31 of whom were treated with more than 6.7 million units of unactivated prothrombin complex concentrates (PCC) during the years 1978 through 1982 for more than 1,000 bleeding episodes. Twelve of the patients who were on home therapy used 3.1 million units, or 47% of the total PCC usage. Only one patient had a severe life-threatening allergic reaction to PCC, and no thrombotic complications were observed, supporting the concept that these products are safe when used in doses of 50-75 u/Kg. Fifty percent of hemarthroses and 65% of muscle hemorrhages were treated with no more than two infusions per episode, suggesting that PCC was effective at least half of the time. Comparison of the number of days hospitalized per year for inhibitor and non-inhibitor patients also indicated that PCC was effective, although not as effective as AHF therapy in non-inhibitor patients. The life styles of PCC treated patients were comparable to what might be expected for non-inhibitor patients with severe disease, and no deaths were attributed to PCC treatment failure during the four year period. Of major concern, however, was the cost of therapy. In 1981-82, the average use of PCC for inhibitor patients was 106,000 units per treated patient per year, compared to 40,000 AHF units for all Factor VIII deficient treated patients per year. Much of this usage was for recurrent hemarthroses in a small number of patients requiring eight or more infusions per episode.

Antigens↗

Thrombocytopenia in the newborn.

Infants with platelet counts below 100,000/mm3 should be evaluated for the cause of the thrombocytopenia. A maternal history to determine previous illnesses and particularly thrombocytopenia, drugs taken, and perinatal complications is important, and a maternal platelet count must be obtained. Physical examination of the infant is revealing in the TAR and giant cavernous hemangioma syndromes and may suggest intrauterine infection. A complete blood cell count (CBC) should be done to look for associated anemia and neutropenia or for polycythemia. Red cell morphology may be helpful. A bone marrow examination may be necessary if the etiology is unclear after the initial studies are done. Investigation of the well child will usually find an etiology for the thrombocytopenia. It is important to consider and test for isoimmune thrombocytopenia and intrauterine infection. In the ill infant multiple factors may contribute to a low platelet count, and a single, precise etiology often cannot be established. Thrombocytopenia with or without DIC may be an important indicator of sepsis. Platelet transfusions are helpful if the thrombocytopenia is due to decreased production or intrinsic platelet defects. In disorders with increased platelet destruction, donor platelets may survive long enough to be of some benefit. In ill infants treatment of the underlying problem often results in resolution of the thrombocytopenia. Transfusions should be used for the bleeding child and for the infant with severe thrombocytopenia who is the product of a vaginal delivery. In addition to being therapeutic, platelet transfusions may also assist in diagnosis.

Autoantibodies↗

Sternal cupping: a new finding in childhood sickle cell anemia.

Discrete cupping of sternal segments has not been reported previously in children with sickle cell anemia (SCA). In a retrospective study, this phenomenon was observed in 8% of children with homozygous SCA and in 10.6% of children with sickle cell-hemoglobin C disease, and thus should be included in the spectrum of osseous abnormalities associated with this disease. In this review, sternal cupping was a temporary phenomenon of little clinical significance. However, radiologists should be aware of this finding so that it is not mistaken for a more serious pathologic process in the sternum.

Adolescent↗

Abnormal red cell membrane proteolytic activity in severe heterozygous beta-thalassemia.

A 63-year-old man of italian origin with severe heterozygous beta-thalassemia whose clinical condition deteriorated after splenectomy is described. The alpha/beta synthesis ration in the peripheral blood was 3.02 +/- 0.56 and in the bone marrow 1.43. The free alpha-chain pool comprised 73% of the total radioactive alpha-globin in the peripheral blood and 68% in the bone marrow. RBC membranes isolated from erythrocytes incubated in the presence of 14C-leucine were practically devoid of nascent beta-chains with an alpha/beta ratio of 5.12 +/- 1.47, significantly higher than that present in the corresponding hemolysate. RBC membranes from this patient, compared to control membrane preparations, showed increased proteolytic activity directed against tetrameric hemoglobin and beta-hemoglobin chains, with concomitant decreased catabolism of alpha-hemoglobin chains. RBC membranes from individuals with mild beta-thalassemia trait and from transfused patients with homozygous beta-thalassemia degraded alpha-hemoglobin chains more efficiently than those from the patient described. The data suggest that decreased degradation of the alpha-chain by RBC membranes from this patient might lead to progressive accumulation of this polypeptide and expansion of the free alpha-chain pool, which, in turn, may be responsible for the severity of the clinical picture.

Bone Marrow↗

Orbital infarction in sickle cell disease.

Bone infarction is a common occurrence in sickle cell disease. Described are three cases in which frontal headache, proptosis, and lid edema were seen with infarction of the orbital bone. Radionuclide scanning was useful in distinguished bone infarction from orbital infection in one case.

Adolescent↗