Urgent Transfusion in a New Patient with Rare Blood Type

Background/Case Studies: Bombay is a rare blood group characterized by the absence of H substance at the surface of RBCs leading to naturally occurring anti-H antibodies. Anti-H presents the risk of severe hemolytic transfusion reactions in these patients. The case presented is of a 32-year-old female of Middle Eastern origin, who presented with a traumatic vertebral fracture with spinal cord compression and required urgent neurosurgery. Her presenting hemoglobin was 84 g/L. She had no previous group and screen on record, had never been transfused and had a history of a remote miscarriage. Study Design/Methods: Forward blood group with an automated gel-method instrument revealed the following reactions: negative with anti-A, unable to interpret (?) with anti-B, 4+ with anti-D. Reverse grouping revealed the following reactions: 4+ with A1-cells and an unexpected 1+ with B-cells. The antibody screen and 11 cell panel in gel (Micro Typing Systems) 2+; the panel, with enhancement reacted 3+ in Ficin. The auto control was negative. A second panel and pre-warm panel produced the same findings. An antibody reacting at 37C against a high-frequency antigen was suspected. Patient specimen was sent for investigation to the reference lab (RL), which performed blood group by manual tube test, antibody identification with panels by manual tube PEG-IAT method; RL also sent a sample for ABH sequencing (Sanger). Results/Findings: A thawed frozen plasma sample from a previous Bombay patient 12 years prior showed no reactivity against the patient's RBCs; positive control included. A frozen Bombay RBC unit was ordered urgently from the blood supplier and was crossmatch compatible. The patient underwent surgery and was transfused with a single unit of RBC for peri-operative bleeding. She was treated with erythropoietin and IV iron post-operatively and did not require any further transfusions. The investigation at the RL showed mixed field reaction on forward blood typing with anti-B and anti-A,B and negative reaction with anti-A commercial reagents. The RL reverse grouping showed 4+ with all O H+ and A1 red cells, but 2+ with B cells. The autocontrol and group O H- cells did not react, confirming anti-H and suggesting Para-Bombay group. ABH sequencing revealed a normal B allele (ABO*B.01) while genotyping of FUT1 revealed a null allele (FUT1*01N.12) and weak H allele (FUT1*01W.23). FUT2 genotyping (FUT2*01N.02) predicted a nonsecretor (sese) phenotype. Conclusions: This patient with non-secretor status, variant H production, clinically significant anti-H, greatly reduced B antigen expression, should be treated as a Bombay (Oh) for transfusion purposes. She was counselled and provided with an antibody card and a letter. This case illustrates the importance of timely communication with the clinical team about the risks and benefits of transfusion pending antibody identification, as it could have proved fatal in this case. Figure Disclosures Pavenski: Bioverativ:Research Funding;Shire/Takeda:Honoraria;Octapharma:Research Funding;Alexion:Honoraria, Research Funding;Sanofi:Research Funding;Ablynx/Sanofi:Honoraria, Research Funding.

Review of Time and Space Harmonics in Multi-Phase Induction Machine

Modern multiphase electric machines take advantage of additional degrees of freedom for various purposes, including harmonic current injection to increase torque per ampere. This new approach introduces a non-sinusoidal air gap flux density distribution causing additional technical problems and so the conventional assumptions need to be revised. The paper presents a methodology for synthesis of air gap magnetic field generated by a symmetrically distributed multiphase windings including the rotor field reaction due to the machine’s load. The proposed method is suitable either for single-layer or double layer windings and can be adopted either for full-pitched or chorded winding including slots effects. The article analyses the air gap flux density harmonic content and formulates conclusions important to multiphase induction motors. It also discusses effects of time harmonic currents and illustrates the principle of changing number of pole-pairs typical for harmonic currents being injected to increase torque.

Nonclassical Symmetry Solutions for 4th Order Phase Field Reaction-Diffusion

Using a nonclassical symmetry of nonlinear reaction-diffusion equations, some exact multi-dimensional time-dependent solutions are constructed for a fourth-order Allen-Cahn-Hilliard equation. This models a phase field that gives a phenomenological description of a two-phase system near the critical temperature. Solutions are given for the changing phase of a cylindrical or spherical inclusion, allowing for a 'mushy zone' with mixed state that is controlled by imposing a pure state at the boundary. The diffusion coefficients for transport of one phase through the mixture, depend on the phase field value, since the physical structure of the mixture depends on the relative proportions of the two phases. A source term promotes stability of both of the pure phases but this tendency may be controlled or even reversed through the boundary conditions.

AAC Redwater hard red spring wheat

AAC Redwater is a hard red spring wheat (Triticum aestivum L.) adapted to the shorter season wheat-growing regions of the Canadian prairies. AAC Redwater was evaluated in the Parkland Wheat Cooperative Test in 2009, 2010, and 2011. AAC Redwater was significantly (P < 0.05) higher yielding than Katepwa (6.4%) and AC Splendor (7.5%) and was not significantly different in grain yield compared to CDC Teal and CDC Osler. AAC Redwater had maturity similar to AC Splendor, matured a day earlier than Katepwa, and was significantly earlier maturing (2 d) than CDC Teal and CDC Osler. AAC Redwater was significantly shorter than all check cultivars and had a similar mean lodging score to the check cultivars. AAC Redwater is resistant to moderately resistant to leaf and stem rust, comparable to AC Splendor. AAC Redwater was resistant to intermediate in its field reaction to stripe rust and intermediate in its reaction to the Ug99 stem rust race, similar to CDC Teal. At the time of registration, AAC Redwater met the end-use quality specifications of the Canada Western Red Spring wheat class.

New Approach to Ammonia Synthesis by Catalysis in Magnetic Field

Ammonia production is a capital-intensive industry as it requires high temperature (400-500oC) and also high pressure (150-300 bar) for its daily operations. An earnest effort was made to synthese ammonia gas using an in-house designed microreactor. The production of ammonia was carried out in a magnetic field reaction zone, with the reaction temperature of 30°C - 280°C and ambient operation pressure. Mn0.8Zn0.2Fe2O4 nanoparticles, synthesized using the sol gel method, were used as the catalyst for the ammonia synthesis. XRD confirmed the single phase ferrites and FESEM images revealed nanofibre-like morphology when sintered at 700oC in argon gas. Electron diffraction was performed using HRTEM and obtained diffraction patterns confirmed the crystal structure of the catalyst. By using the Kjeldahl method it was found that the reaction carried out in 1 Tesla magnetic field gave approximately 46% ammonia yield. The proposed new method could be appealing for ammonia manufacturers due to highly economical implication which may offer urea producers a potential contender in the competitive market place.