Novel regulatory variant in ABO intronic RUNX1 binding site inducing A3 phenotype.

BACKGROUND AND OBJECTIVES: Mixed-field agglutination in ABO phenotyping (A3, B3) has been linked to genetically different blood cell populations such as in chimerism, or to rare variants in either ABO exon 7 or regulatory regions. Clarification of such cases is challenging and would greatly benefit from sequencing technologies that allow resolving full-gene haplotypes at high resolution. MATERIALS AND METHODS: We used long-read sequencing by Oxford Nanopore Technologies to sequence the entire ABO gene, amplified in two overlapping long-range PCR fragments, in a blood donor presented with A3B phenotype. Confirmation analyses were carried out by Sanger sequencing and included samples from other family members. RESULTS: Our data revealed a novel heterozygous g.10924C>A variant on the ABO*A allele located in the transcription factor binding site for RUNX1 in intron 1 (+5.8 kb site). Inheritance was shown by the results of the donor's mother, who shared the novel variant and the anti-A specific mixed-field agglutination. CONCLUSION: We discovered a regulatory variant in the 8-bp RUNX1 motif of ABO, which extends current knowledge of three other variants affecting the same motif and also leading to A3 or B3 phenotypes. Overall, long-range PCR combined with nanopore sequencing proved powerful and showed great potential as an emerging strategy for resolving cases with cryptic ABO phenotypes.

Stepwise partitioning of Xp21: a profiling method for XK deletions causative of the McLeod syndrome.

BACKGROUND: McLeod syndrome (MLS) is hematologically defined by the absence of the red blood cell (RBC) antigen Kx on the transmembrane RBC protein, XK, representing a highly specific diagnostic marker. Direct molecular assessment of XK therefore represents a desirable diagnostic tool. Whereas pathogenic point mutations may be simply identified, partial and complete deletions of XK on Xp21.1, eventually covering adjacent genes and causing multifaceted "continuous gene syndromes," are difficult to localize. STUDY DESIGN AND METHODS: Three different McLeod patient samples were tested using 16 initial positional polymerase chain reaction (PCR) procedures distributed over an approximately 2.8-Mbp Xp-chromosomal region, ranging telomeric from MAGEB16 to OTC, centromeric of XK. The molecular breakpoint of one sample with an apparent large Xp deletion was iteratively narrowed down by stepwise positioning further PCR procedures and sequenced. Two mutant XK genes, one previously published and serving as a positive control, were also sequenced. RESULTS: We confirmed the positive control as previously published and listed as XK*N.20 by the International Society of Blood Transfusion (ISBT). The other XK showed a novel four-nucleotide deletion in Exon 1, 195-198delCCGC (newly listed as XK*N.39 by the ISBT). The third sample had an approximately 151-kbp X-chromosomal deletion, reaching from Exon 2 of LANCL3, across XK to Exon 3 of CYBB (newly listed as XK*N.01.016 by the ISBT). Carrier status of the patients' sister was diagnosed using a diagnostic "gap-PCR." CONCLUSIONS: The stepwise partitioning of Xp21.1 is pragmatic and cost-efficient in comparison to other diagnostic techniques such as "massive parallel sequencing" given the rarity of MLS. All males with suspected MLS should be considered for molecular XK profiling.

Analysis of platelet-derived extracellular vesicles in plateletpheresis concentrates: a multicenter study.

BACKGROUND: Routine quantification of platelet-derived extracellular vesicles (PL-EVs) may be useful in the quality control (QC) of platelet concentrates (PCs). The aim of this multicenter study was to establish and validate a consensus protocol for the standardized PL-EV quantification using conventional flow cytometers. STUDY DESIGN AMD METHODS: Eighty-six PCs were investigated in five blood transfusion centers (A-E) on Days 0 and 5. The centers used different apheresis instruments: Trima Accel (n = 56) and/or Amicus (n = 30). PCs were prepared using standard methods (sd-PCs; n = 73; A-D) or with pathogen inactivation (PI [PI-PCs]; n = 13; E). Platelet (PLT) count was determined using conventional hematology analyzers. PLT degranulation (P-selectin expression in response to thrombin receptor PAR1 activation) and PL-EVs were analyzed by flow cytometry. RESULTS: During storage, PLT count remained stable in 58 PCs (A, C, E), whereas a decrease was observed in 12 PCs (B). PLT degranulation declined in all PCs (p < 0.001) and PL-EVs increased in 74 PCs (A, C-E; p < 0.001). Certain donor variables (e.g., plasma cholesterol, immature PLT fraction) were associated with lower PL-EVs. In Trima-produced PCs, PL-EVs were significantly lower (D) and PLT degranulation was superior compared to PCs prepared with the Amicus (A, D). PL-EVs were 10-fold lower in PI-PCs, compared to sd-PCs. However, similar QC trends were demonstrated for both PC groups during storage. CONCLUSION: PL-EV analysis in a QC program of PCs was successfully performed with results comparable among the different centers. PLT degranulation and vesiculation were primarily affected by preparation techniques.

Laminin-6 assembles into multimolecular fibrillar complexes with perlecan and participates in mechanical-signal transduction via a dystroglycan-dependent, integrin-independent mechanism.

Mechanical ventilation is a valuable treatment regimen for respiratory failure. However, mechanical ventilation (especially with high tidal volumes) is implicated in the initiation and/or exacerbation of lung injury. Hence, it is important to understand how the cells that line the inner surface of the lung [alveolar epithelial cells (AECs)] sense cyclic stretching. Here, we tested the hypothesis that matrix molecules, via their interaction with surface receptors, transduce mechanical signals in AECs. We first determined that rat AECs secrete an extracellular matrix (ECM) rich in anastamosing fibers composed of the alpha3 laminin subunit, complexed with beta1 and gamma1 laminin subunits (i.e. laminin-6), and perlecan by a combination of immunofluorescence microscopy and immunoblotting analyses. The fibrous network exhibits isotropic expansion when exposed to cyclic stretching (30 cycles per minute, 10% strain). Moreover, this same stretching regimen activates mitogen-activated-protein kinase (MAPK) in AECs. Stretch-induced MAPK activation is not inhibited in AECs treated with antagonists to alpha3 or beta1 integrin. However, MAPK activation is significantly reduced in cells treated with function-inhibiting antibodies against the alpha3 laminin subunit and dystroglycan, and when dystroglycan is knocked down in AECs using short hairpin RNA. In summary, our results support a novel mechanism by which laminin-6, via interaction with dystroglycan, transduces a mechanical signal initiated by stretching that subsequently activates the MAPK pathway in rat AECs. These results are the first to indicate a function for laminin-6. They also provide novel insight into the role of the pericellular environment in dictating the response of epithelial cells to mechanical stimulation and have broad implications for the pathophysiology of lung injury.

Fibroblast growth factor-10 attenuates H2O2-induced alveolar epithelial cell DNA damage: role of MAPK activation and DNA repair.

Fibroblast growth factor-10 (FGF-10), an alveolar epithelial cell (AEC) mitogen that is critical for lung development, may promote AEC repair. We determined whether FGF-10 attenuates H2O2-induced, A549 and rat alveolar type II cell DNA damage. We show that FGF-10 prevents H2O2-induced DNA damage assessed by an alkaline elution, ethidium bromide fluorescence as well as by a comet assay. Mitogen-activated protein kinase inhibitors abolished the protective effect of FGF-10 against H2O2-induced DNA damage yet had no effect on H2O2-induced DNA damage. A Grb2-SOS inhibitor (SH3 binding peptide), an Ras inhibitor (farnesyl transferase inhibitor 277), and an Raf-1 inhibitor (forskolin) each prevented FGF-10- and H2O2-induced A549 cell ERK1/2 phosphorylation. Also, FGF-10 and H2O2 each induced negligible ERK1/2 phosphorylation in Ras dominant-negative (N17) cells. Inhibitors of Ras and Raf-1 blocked the protective effect of FGF-10 against H2O2-induced DNA damage but had no effect on H2O2-induced DNA damage. Furthermore, cold conditions and aphidicolin, an inhibitor of DNA polymerase-alpha, -delta, and -epsilon, each blocked the protective effects of FGF-10, suggesting a role for DNA repair. We conclude that FGF-10 attenuates H2O2-induced AEC DNA damage by mechanisms that involve activation of Grb2-SOS/Ras/RAF-1/ERK1/2 pathway and DNA repair.

FGF-10 prevents mechanical stretch-induced alveolar epithelial cell DNA damage via MAPK activation.

Cyclic stretch of alveolar epithelial cells (AEC) can alter normal lung barrier function. Fibroblast growth factor-10 (FGF-10), an alveolar type II cell mitogen that is critical for lung development, may have a role in promoting AEC repair. We studied whether cyclic stretch induces AEC DNA damage and whether FGF-10 would be protective. Cyclic stretch (30 min of 30% strain amplitude and 30 cycles/min) caused AEC DNA strand break formation, as assessed by alkaline unwinding technique and DNA nucleosomal fragmentation. Pretreatment of AEC with FGF-10 (10 ng/ml) blocked stretch-induced DNA strand break formation and DNA fragmentation. FGF-10 activated AEC mitogen-activated protein kinase (MAPK), and MAPK inhibitors prevented FGF-10-induced AEC MAPK activation and abolished the protective effects of FGF-10 against stretch-induced DNA damage. In addition, a Grb2-SOS inhibitor (SH(3)b-p peptide), a RAS inhibitor (farnesyl transferase inhibitor 277), and a RAF-1 inhibitor (forskolin) each prevented FGF-10-induced extracellular signal-regulated kinase (ERK) 1/2 phosphorylation in AEC. Moreover, N17-A549 cells that express a RAS dominant/negative protein prevented the FGF-10-induced ERK1/2 phosphorylation and RAS activation in AEC. We conclude that cyclic stretch causes AEC DNA damage and that FGF-10 attenuates these effects by mechanisms involving MAPK activation via the Grb2-SOS/Ras/RAF-1/ERK1/2 pathway.

Cyclic stretch activates ERK1/2 via G proteins and EGFR in alveolar epithelial cells.

Mechanical stimuli are transduced into intracellular signals in lung alveolar epithelial cells (AEC). We studied whether mitogen-activated protein kinase (MAPK) pathways are activated during cyclic stretch of AEC. Cyclic stretch induced a rapid (within 5 min) increase in extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation in AEC. The inhibition of Na(+), L-type Ca(2+) and stretch-activated ion channels with amiloride, nifedipine, and gadolinium did not prevent the stretch-induced ERK1/2 activation. The inhibition of Grb2-SOS interaction with an SH3 binding sequence peptide, Ras with a farnesyl transferase inhibitor, and Raf-1 with forskolin did not affect the stretch-induced ERK1/2 phosphorylation. Moreover, cyclic stretch did not increase Ras activity, suggesting that stretch-induced ERK1/2 activation is independent of the classical receptor tyrosine kinase-MAPK pathway. Pertussis toxin and two specific epidermal growth factor receptor (EGFR) inhibitors (AG-1478 and PD-153035) prevented the stretch-induced ERK1/2 activation. Accordingly, in primary AEC, cyclic stretch activates ERK1/2 via G proteins and EGFR, in Na(+) and Ca(2+) influxes and Grb2-SOS-, Ras-, and Raf-1-independent pathways.

A tonometria como índice prognóstico / The tonommetry as a prognostic index

Foram estudados prospectivamente 16 pacientes gravemente enfermos cujo índice Apache médio foi de 27. Todos os pacientes tiveram pHi monitorado desde a admissao até a alta ou a morte. Nove nao sobreviventes tiveram valores de pHi significantemente reduzidos enquanto sete sobreviventes tiveram estes valores superiores a 7,30. Quando 7,30 foi considerado o valor limítrofe (Cult-off), o pHi teve 100 por cento de sensibilidade e especificidade na prediçao dos resultados. Concluímos que o pHi é mais sensível que o Apache II em prognosticar os resultados em pacientes gravemente doentes.

Terapêutica combinada da crise de asma refratária: ventilaçäo com pressäo controlada, PEEP, anestesia inalatória com isofluorano e lavado bronco-alveolar / Combined therapy of the status asthmaticus: pressure controlled ventilation, PEEP, isofluorane anesthesia and bronchoalveolar lavage

Um crescente número de pacientes tem sido admitido nos hospitais com crise de asma aguda. Destes, 1 a 3 por cento requerem suporte ventilatório. A ventilaçäo mecânica convencional apresenta alta morbidade e mortalidade relacionadas ao barotrauma. Desde 1980, a hipoventilaçäo controlada tem sido descrita como um método eficaz e seguro de tratamento para a crise de asma aguda quase fatal diminuindo o risco de barotrauma e falência cardiocirculatória. Relatamos o caso de uma paciente de 21 anos com quadro de exacerbaçäo aguda da asma e que necessitou de ventilaçäo mecânica. A despeito do uso de ventilaçäo com pressao controlada, PEEP extrínseco e hipoventilaçäo associada ao uso de salbutamol endovenoso, aminofilina, e corticosteróides näo houve melhora após 72 horas. Optado pela introduçäo de anestesia inalatória com isofluorano, e realizaçäo de lavado bronco-alveolar com saída de rolhas de muco, ocorrendo melhora significativa da obstruçäo brônquica. A paciente pode ser extubada sem complicaçöes no nono dia.

Doença pulmonar intersticial de prodomínio cístico em mulher / Interstitial lung disease with cystic predominance in a woman

Apresentamos o caso de uma mulher em idade fértil com tosse, dispnéia, hipoxemia e diminuiçäo da capacidade vital forçada, e que, à radiografia de tórax, apresentava infiltrado intersticial reticular difuso, sem diminuiçäo dos campos pulmonares. O estudo tomográfico de alta resoluçäo do tórax evidenciou múltiplos cistos bem formados, distribuidos igualmente pelo parênquima. Com esse aspecto radiológico em mulher jovem os dois diagnósticos mais prováveis seriam: linfangioleiomiomatose e granuloma eosinófilo. Submetida a biópsia pulmonar a céu aberto, diagnosticou-se granuloma eosinófilo primário de pulmäo