Blood donation and transfusion practices: the 1990 American Association of Blood Banks Institutional Membership Questionnaire

Responses to the 1990 American Association of Blood Banks (AABB) Institutional Membership Questionnaire were submitted by 2126 regional blood centers, hospital-based blood banks, and transfusion facilities. Data from 2117 of these facilities were considered to be valid. The questionnaire included information on blood donor demographics, number of units collected, and collection procedures; services performed; usage of blood components; and transfusion-transmitted diseases reported during 1989. Institutional members collected 7.4 million whole blood units, of which 90.8 percent were donated for allogeneic use, 6.0 percent were donated for autologous use, and 3.2 percent were donated for directed use. Approximately 630,546 allogeneic and directed-use blood donors were deferred, most often for low hemoglobin or hematocrit values. Approximately 225,205 full allogeneic and directed-donor units were discarded, primarily for elevated alanine aminotransferase levels or the presence of hepatitis B core antibody. The 14.3 million transfused components included 56.7 percent red cell-containing components, 27.4 percent platelets, 11 percent fresh-frozen plasma, and 4.8 percent cryoprecipitate. Institutional members reported 1397 cases of transfusion-associated hepatitis. In this group, 921 patients were tested for hepatitis B surface antigen after the transfusion; 339 (36.8%) were found to be hepatitis B surface antigen positive. The AABB Institutional Questionnaire results provide recent data on blood donor and transfusion-related activities that are vital to the evaluation of current transfusion medicine practices.     

Ambiguous phenotypes and genotypes in 16 children with acute leukemia as characterized by multiparameter analysis

Ambiguous phenotypes and genotypes were observed in 16 children with acute leukemia. Surface marker, cytogenetic, molecular genetic, and DNA flow cytometric analyses as well as standard morphologic and cytochemical studies were used to divide the patients into three groups. The first group comprised five children with acute leukemia whose blast cells were morphologically lymphoid, while immunophenotyping disclosed simultaneous expression of early pre-B cell and myeloid features. Molecular genetic studies showed evidence of heavy-chain immunoglobulin (Ig) gene rearrangements in all patients. Cytogenetic data, available in three of these children, revealed t(4;11). In five of the 16 patients, morphologic and surface marker analyses indicated the coexistence of two separate cell populations, one with myeloid and the other with early pre-B cell features. Further evidence of B cell commitment in these patients was provided by demonstration of Ig heavy-chain gene rearrangements in all five patients. Surprisingly, one of the five patients showed oligoclonal Ig heavy-chain as well as monoclonal gene rearrangement for the beta chain of the T cell receptor (beta-TCR). The last group consisted of four cases with otherwise typical acute lymphoblastic leukemia (ALL), early pre-B cell phenotype, and coexpression of myeloid or T cell-associated antigens, and two children with unequivocal acute myeloid leukemia (AML) and coexpression of T cell antigens. Gene rearrangement of Ig heavy-chain could be demonstrated in five of six patients, additional Ig light-chain gene rearrangement in two children with ALL, and bigenotypic features (Ig heavy-chain and beta-TCR gene rearrangement) in one patient. In none of the 16 patients did flow cytometry disclose clonal abnormalities of leukemic cell DNA content. Based on these findings, we suggest that malignant transformation in the first and second group of patients took place at a stage ontogenetically close to the pluripotent stem cell, whereas ambiguous phenotypes in the third group resulted from aberrant gene expression or insufficient reagent specificity.     

Phospholipid transfer between plasma and platelets in vitro

Washed rabbit platelets were resuspended in plasma in which all of the major phospholipids had been isotopically labeled by injection of 32PO4 into rabbits. At certain time intervals during a 6-hr incubation at 37 degrees C, aliquots were removed from the incubation mixture and the platelets were isolated and subjected to lipid extraction and phospholipid analysis. A continuous rise in platelet non-lipid-bound and lipid-bound radioactivity was observed through-out the incubation period. Two platelet phospholipids, lecithin and lysolecithin, were significantly labeled, whereas little or no labeling of the other phospholipids was found. There was no detectable change in total or individual platelet phospholipid content. At 6 hr, 4% of total platelet phospholipid, 43% of platelet lysolecithin, and 7% of platelet lecithin were labeled. Platelets incubated in plasma from rabbits with diet- induced hyperlipidemia took up and incorporated significantly more label into their phospholipids than did platelets in normal plasma. Labeling of both platelet lysolecithin and lecithin could be due to uptake and metabolism of plasma lysolecithin by platelets. However, labeling of platelet lecithin could at least in part be the result of direct exchange of this phospholipid with the plasma. Uptake and incorporation of endogenous plasma lysolecithin by platelets and, possibly, direct exchanged of platelet lecithin may be important mechanisms in the modification by plasma lipids of platelet membrane phospholipid fatty acid composition and platelet function.     

Effect of alfacalcidol on cardiac function in patients with chronic kidney disease stage 4 and secondary hyperparathyroidism: A pilot study

Abstract Objective. Left ventricular hypertrophy (LVH) is highly prevalent in chronic kidney disease (CKD) and a risk marker for cardiovascular mortality. It was hypothesized that vitamin D deficiency could play an important role in the pathogenesis of left ventricular hypertrophy and dysfunction in CKD. An open-labelled randomized study was performed comparing the effect of alfacalcidol versus no treatment in patients with CKD 4, secondary hyperparathyroidism and LVH. The primary endpoint was regression of LVH. Secondary endpoints were changes in left ventricular function. Material and methods. Twenty-four patients were screened. Of these, 14 had LVH according to the criteria used. Six were randomized to alfacalcidol and seven to no treatment. The patient follow-up was 6 months. Left ventricular mass and function were measured by echocardiography. Results. Parathyroid hormone decreased by 72% and -3% in the alfacalcidol-treated and non-treated groups, respectively (p < 0.05), while serum Ca(2+) increased by 9% and -1.6%, respectively (p < 0.05), and serum phosphate was unchanged. The left ventricular mass index was unchanged, whereas fractional shortening (20% vs 2%, p < 0.005) and Tei index (36% vs 12%, p < 0.05) increased significantly. Systolic and diastolic blood pressure was unchanged. Conclusion. Short-term treatment with alfacalcidol did not induce regression of LVH; however, left ventricular function became hyperdynamic but less effective in patients with CKD. This could be problematic in the long term.     

Swedish pediatric diabetes teams' perception of fathers' involvement: A Grounded Theory study

The purpose of this study was to analyze how Swedish pediatric diabetes teams perceived and discussed fathers' involvement in the care of their child with type 1 diabetes. It also aimed to discuss how the teams' attitudes towards the fathers' involvement developed during the data collection process. The Constructivist Grounded Theory design was used and data were collected during three repeated focus group discussions with three Swedish pediatric diabetes teams. The core category of the teams' perception of fathers' involvement emerged as: If dad attends, we are happy – if mom doesn't, we become concerned. Initially the teams balanced their perception of fathers' involvement on the mother's role as the primary caregiver. In connection with the teams' directed attention on fathers, in the focus group discussions, the teams' awareness of the importance of fathers increased. As a consequence, the team members began to encourage fathers' engagement in their child's care. We conclude that by increasing the teams' awareness of fathers as a health resource, an active health promotion perspective could be implemented in pediatric diabetes care.     

Pharmacokinetics and protein binding of intravenous ibuprofen in the premature newborn infant

The elimination, disposition and protein binding of ibuprofen (IBU) in premature infants were studied for use in the prevention of intraventricular hemorrhage and closure of patent ductus arteriosus. The kinetic profile of i.v. IBU lysine (10 mg/kg bolus) given within the first 3 h after birth was studied in 21 premature neonates (mean birthweight = 944.7 g, range: 575–1450 g; gestational age: 26.8 weeks, range: 22–31 weeks). Blood samples (0.3 ml/sample) were obtained at time 0 and at 1, 3, 6, 12, 24, 48, and 72 h post-dose for IBU by high-performance liquid chromatography (HPLC). Kinetic analyses assumed applicability of one open-compartment model and calculations from the model-independent areas under the time concentration curve (AUC). Data (mean ± SEM) show that apparent volume of distribution (AVd) was 62.1 ± 3.9 ml/kg, plasma t _1/2 beta was 30.5 ± 4.2 h, elimination rate constant (k_el) was 0.032 ± 0.004 h^-1plasma clearance was 2.06 ± 0.33 ml/kg/h and plasma concentration (Cp) at 1 h was 180.6 ±11.1 mg/1. Gestational age and birthweight were not related to drug elimination. In 10 neonates, IBU maintenance dose of 5 mg/kg once daily on days 2 and 3 generated mean Cp of 116.6 ± 54.5 mg/1 and 113.6 ± 58.2mg/1, respectively. Protein binding by ultrafiltration and capillary electrophoresis showed that the percentage bound IBU was significantly lower in full term cord plasma (94.98 ± 0.39%, n = 26) compared to adult plasma protein (mean ± SE = 98.73 ± 0.31%, n = 8, p < 0.0001). Compared to data from adults and older children, IBU elimination is markedly prolonged in neonates and protein binding is slightly lower. Thus, investigational and clinical therapeutic regimens should be adjusted to account for decreased drug disposition to ensure safe and effective therapy.     

Meniscal tears of the knee: accuracy of MR imaging

Before surgery, 277 menisci in 144 knees were examined with magnetic resonance (MR) imaging. They were then examined directly with arthroscopy or arthrotomy. Menisci were graded on a scale of 1-3 according to the character of the intrameniscal MR imaging signal. At surgery, 137 of 154 (89%) menisci exhibiting only grade 1 or grade 2 signal were found to be normal. One hundred sixteen of 123 (94%) menisci exhibiting intrameniscal signal communicating with a meniscal articular surface (grade 3 signal) had tears. If only a grade 3 signal is considered consistent with meniscal tears, then MR findings and surgical findings agreed in 91.3% of menisci. MR imaging can separate surgically significant from nonsignificant meniscal lesions and is useful in the noninvasive preoperative screening of suspected meniscal tears.     

Functional evaluation of regenerated and misrouted low threshold mechanoreceptors and polymodal nociceptors in the skin of rat hindfeet after crush lesions to the sciatic nerve.

Tracer studies on motor axons after nerve crush injuries have indicated that misrouting may occur even when the endoneurium is intact. Misrouting of regenerated polymodal nociceptive C-fibres and low threshold mechanoreceptive axons have been studied functionally in 50 rats three months after unilateral crush lesions to the sciatic nerve. Two weeks before evaluation the tibial fascicle (or the peroneal fascicle) above the lesion was cut and tied off. In this way only functional regeneration of misrouted axons was tested. Misrouted low threshold mechanoreceptive axons and polymodal nociceptor C-fibres were found after regeneration in both glabrous and hairy skin. We conclude that functional misdirection of both myelinated and unmyelinated sensory axons innervating either glabrous or hairy skin can occur after a crush lesion to a peripheral nerve in rats.