Effect of infants’ position on serum bilirubin level during conventional phototherapy

Aim: To compare the decrease in total serum bilirubin (TSB) concentration during conventional phototherapy in infants treated in supine position exclusively versus infants alternated between exposure in supine and prone position every third hour. Moreover, to survey current practice patterns in two Scandinavian countries as far as alternating exposure. Methods: A total of 112 infants with non‐haemolytic hyperbilirubinaemia, but otherwise healthy, and a gestational age ≥33 weeks were randomized to one of the treatment groups. All infants received phototherapy for 24 h. TSB was measured at start of phototherapy and after 12 and 24 h of treatment. Questionnaires about routines for position changes in infants during phototherapy were sent to all 41 neonatal departments in Denmark and Norway. Results: No statistically significant differences in the decrease in TSB were observed between the two treatment groups: at 12 h of therapy, TSB decreased 32% in both groups and at 24 h 49% and 50%, respectively. In two‐thirds of Danish and Norwegian departments, the infants were routinely turned during phototherapy, most often every third hours. Conclusion: The decrease in TSB was not significantly associated with positioning of the infant during conventional phototherapy. Alternating exposure is widely practiced in Scandinavia but is unnecessary.     

Promoter polymorphism of transforming growth factor-β1 gene and ulcerative colitis

AIM: To elucidate the possible difference in two promoter polymorphisms of the transforming growth factor-β1 (TGF-β1) gene (-800G > A, -509C > T)between ulcerative colitis (UC) patients and normal subjects.METHODS: A total of 155 patients with established ulcerative colitis and 139 normal subjects were selected as controls. Two single nucleotide polymorphisms within the promoter region of TGF-β1 gene (-509C > T and -800G > A) were genotyped using PCR-RFLP.RESULTS: There was a statistically significant difference in genotype and allele frequency distributions between UC patients and controls for the -800G > A polymorphism of the TGF-β1 gene (P < 0.05). The frequency of the TGF-β1 gene polymorphism at position -800 showed that the AA genotype and the allele A frequencies significantly differed between the patients and healthy controls (P <0.05). At position -509, there was no statically significant difference in genotype and allele frequency between the patients and control subjects.CONCLUSION: The results of our study indicate that there is a significant difference in both allele and genotype frequency at position -800G > A of TGF-β1 gene promoter between Iranian patients with UC and normal subjects.     

Effect of delayed blood processing on the yield of factor VIII in cryoprecipitate and factor VIII concentrate

Current standards for the preparation of factor VIII (FVIII) concentrates from human plasma recommend separation of plasma from red cells (RBCs) within 6 hours of blood donation, thereby reducing the volume of plasma from donated whole blood available for processing to FVIII concentrate. The decay of FVIII clotting activity (FVIII:C) in whole blood and plasma stored at 22 and 4 degrees C and the recovery of FVIII:C in cryoprecipitate and FVIII concentrate prepared from plasma separated from whole blood stored overnight at 4 degrees C were investigated. In whole blood stored at 22 degrees C and plasma stored at either 4 or 22 degrees C, 90 percent of the original FVIII:C was present at 6 hours, 80 percent at 12 hours, and 65 to 70 percent at 18 hours. At these times lower levels of FVIII:C were recovered from whole blood stored at 4 degrees C, that is, 84, 68, and 56 percent, respectively. In cryoprecipitates prepared from plasma separated from RBCs after 18 hours' storage at 4 degrees C (18-hour plasma), 43 percent of FVIII:C activity was recovered, as compared with 61 percent recovered from standard plasma separated within 6 hours of donation (6-hour plasma), p less than 0.05. With large-scale preparation of FVIII concentrates, however, the yield of FVIII:C was similar whether 18- or 6-hour plasma was used. Thus FVIII concentrates--but not cryoprecipitates--can be prepared from plasma separated from whole blood stored at 4 degrees C for up to 18 hours without undue loss of potency.     

Genetic basis of hypo-responsiveness of A/J mice to interleukin-3

Hematopoietic progenitor cells of the A/J strain of mice show a pronounced defect in the ability to form colonies or proliferate in response to interleukin-3 (IL-3). Comparison of immunoblots of A/J mast cells and of mast cells from the C57BL/6 strain that respond normally to IL-3 showed that, in both strains, a 125-kD band of the expected size was recognized by an antibody against the beta chain of the IL-3 receptor, the AIC2A molecule. However, in the C57BL/6 cells, there was an additional 110-kD species not seen in cells of the A/J strain. Analyses using bone marrow-derived mast cells from a panel of A/J x C57BL/6 and A/J x C57BL/6 recombinant inbred (RI) mice showed that the hypo-responsiveness to IL-3 is governed by a single gene. However, the absence of this 110-kD species in the A/J strain did not co-map with IL- 3 hypo-responsiveness but did indeed map to the AIC2A genetic locus. These data show that this trait in the A/J strain was due to a polymorphism of the AIC2A gene unrelated to IL-3 hypo-responsiveness. Typing of the RI strains for the markers D14Mit98, D14Mitl4, and D14Mit133 mapped the locus determining hypo-responsiveness to IL-3 to the subtelomeric region of chromosome 14, the region that also bears the gene encoding the alpha chain of the IL-3 receptor (lL-3Ralpha). Immunofluorescence analyses indicated that IL-3Ralpha protein was undetectable on fresh bone marrow cells from A/J mice, although clearly detectable on cells from the responder C57BL/6 strain. However, IL- 3Ralpha was readily detectable at normal levels on A/J mast cells generated by culture of A/J bone marrow cells in a combination of IL-3 and steel factor. Moreover, IL-3Ralpha on these A/J mast cells appears to be functional in that IL-3 stimulation of these cells results in tyrosine phosphorylation events characteristic of IL-3 signaling, including tyrosine phosphorylation of the beta chain of the IL-3 receptor, Jak-2 kinase, and SHPTP2. Collectively, these data indicate that the hypo-responsiveness of A/J mice to IL-3 is due to a defect in the gene encoding IL-3Ralpha and that, although this defect gives rise to reduced expression of alpha chain on primary bone marrow cells, this defect is not absolute and that, under certain circumstances, A/J cells can express functional receptors.     

Neutrophil deactivation by influenza A viruses: mechanisms of protection after viral opsonization with collectins and hemagglutination-inhibiting antibodies

Bacterial superinfections are a major cause of morbidity and mortality during influenza A virus (IAV) epidemics. Depression of phagocyte functions resulting from attachment of the IAV hemagglutinin (HA) to cell surface sialo-glycoproteins is a likely contributory cause of these infections. We have proposed that the group of collagenous lectins (termed collectins) present in blood and pulmonary surfactant play a role in initial host defense against IAV. We used here several recombinant human surfactant protein D (RhSP-D) preparations to determine the mechanism through which opsonization of IAV with collectins protects neutrophils against the deactivating effects of IAV on cellular respiratory burst responses in vitro. RhSP-D was markedly more potent than antibodies that inhibited viral hemagglutination activity (anti-HA antibodies) at protecting neutrophils in this assay. Unlike the anti-HA antibodies, RhSP-D was protective at concentrations that minimally inhibited viral hemagglutination activity. Two related features of SP-D--the degree of multimerization and the ability to cause aggregation of IAV particles--were critical determinants of the ability of SP-D to protect neutrophils against deactivation. Similarly SP-D-induced viral aggregate formation resulted in enhanced IAV binding to neutrophils and potentiated the ability of the virus itself to trigger neutrophil respiratory burst responses. In contrast to the case of IAV-antibody complexes, SP-D-IAV complexes attached to and activated neutrophils through a neuraminidase-sensitive mechanism (ie, similar to unopsonized IAV). These results indicate that collectin-mediated viral aggregation per se may be an important host defense mechanism not only by virtue of reducing the number of infectious viral particles, but also by promoting phagocyte responsiveness.     

Microtubule organization of unstimulated and stimulated adherent human neutrophils in Chediak-Higashi syndrome

The numbers and length of centriole-associated microtubules of two patients with Chediak-Higashi syndrome (CHS) were examined. Detergent- extracted whole-mount preparations of adherent cells were studied by stereo high-voltage electron microscopy. Under conditions of random migration, neutrophils from both patients had a microtubule organization similar to that of the control; microtubule numbers (28 +/- 3) and length (7.0 +/- 2.8 micron) were within normal range. When cells were treated with phorbol myristate acetate (PMA), differences in the response of the two patients were noted. Neutrophils from patient No. 2 and the control showed a significant rise in numbers (38 +/- 5) and length (9.5 +/- 3.6 micron) of microtubules. In contrast, neutrophils from patient No. 1 were unresponsive to PMA treatment. Because vitamin C is used therapeutically in CHS patients and has been shown to correct microtubule-related cell function, neutrophils were exposed to ascorbic acid. A significant increase in microtubule numbers (35 +/- 6) was observed in cells from the control and patient No. 2 after ascorbate treatment; neutrophils from patient No. 1 showed no increase in microtubule numbers. While ascorbic acid did not affect microtubule length in the control cells, it caused a significant increase in microtubule length in neutrophils from both patients. Results suggest that adherent CHS neutrophils contain centriole-associated microtubules which are normal in number and length. However, differences between patients are observed regarding neutrophil responsiveness to stimuli which induce microtubule polymerization.     

Compartmentalization of cyclic GMP-dependent protein kinase in formyl- peptide stimulated neutrophils

The presence and physiologic role of cyclic GMP-dependent protein kinase (G-kinase) in human neutrophils was investigated by Western blot analysis and immunocytochemistry. Small quantities of G-kinase were found in the cytoskeletal-enriched fraction of neutrophil lysates as detected by Western blots using a polyclonal antibody raised against bovine aorta G-kinase. Immunofluorescence microscopy demonstrated in adherent neutrophils that G-kinase was localized diffusely within the cytoplasm, at the microtubule organizing center, and in the euchromatin of the nucleus. Because cyclic GMP is implicated as a modulator of neutrophil chemotaxis, G-kinase localization was investigated in neutrophils activated with N-formyl-methionyl-leucyl-phenylalanine (fMLP). fMLP stimulated transient focal changes in G-kinase localization that coincided with transient changes in cell shape. G- kinase translocated over a period of 5 minutes from diffuse staining of the cytosol to filaments within the uropod of polarized cells (1 minute), to bundles of filaments associated with loss of cell polarity (2.5 minutes), and finally to more intense staining of the nuclear euchromatin (5 minutes). Optical sectioning of neutrophils by confocal laser scanning microscopy confirmed that G-kinase was restricted to specific sub-cellular compartments during cell activation. This transient localization of G-kinase was disrupted by cytoskeletal inhibitors and was augmented by 8-Br-cyclic GMP. These data provide evidence for the first time that G-kinase plays a physiologic role in human neutrophils, and support the concept of compartmentalization of cyclic nucleotides during neutrophil activation.