MAM: a "new" high-incidence antigen found on multiple cell lines.

BACKGROUND: Three women have been identified with an antibody to a "new" high-incidence antigen found on multiple cell lines. CASE REPORTS: The proposita, M.A.M., presented during her third pregnancy with an antibody reacting with all RBCs tested except her own. She delivered a thrombocytopenic infant with a 3+ DAT, but without symptoms of HDN. The second example, A.N., presented during her third pregnancy with an antibody reacting with all RBCs tested except her own and those of M.A.M. She delivered a slightly thrombocytopenic but severely anemic infant. The third example, F.K., a sister of A.N., has an antibody reacting with all RBCs tested except her own and those of M.A.M. and A.N. CONCLUSION: This "new" high-incidence antigen has been named MAM and assigned high-incidence antigen number 901016 by the International Society of Blood Transfusion. The corresponding antibody, anti-MAM, has been shown to cause HDN and has the potential to shorten RBC survival after the transfusion of incompatible RBC units, as determined by monocyte monolayer assay. Immunoblotting and flow cytometry show that this new antibody reacts with various WBC lines in addition to RBCs. This antibody also appears to react with platelets in some assays.

Assessment of the clinical significance of anti-Dob.

BACKGROUND: Anti-Dob is an uncommon antibody, and there are few data regarding its clinical importance. In the present case, the patient's transfusion management was based on both in vivo and in vitro assay results. CASE REPORT: A delayed hemolytic transfusion reaction was suspected in a 64-year-old white woman awaiting cardiac surgery when the transfusion of 1 unit of red cells failed to raise her hematocrit. Although direct antiglobulin tests were negative, antibody screening tests on samples drawn 9 days after transfusion were positive, and anti-Dob was identified, reacting to a titer of 4. 51Cr in vivo survival studies with incompatible Do(b+) red cells showed poor survival: 83.2 percent at 1 hour, 43 percent at 24 hours, and 29.6 percent at 48 hours and t1/2 = 19 hours (normal t1/2 = 25-35 days). A monocyte monolayer assay performed with the same incompatible Do(b+) donor red cells also indicated poor survival: 22 percent and 30 percent reactive monocytes, respectively, with and without the addition of complement (normal, 0-3%). The patient was given 4 Do(b-) red cell units without clinical signs or symptoms of a reaction. CONCLUSIONS: This example of anti-Dob was implicated in a delayed hemolytic transfusion reaction. The 51Cr survival studies and monocyte monolayer assay results indicated that the anti-Dob was clinically significant, requiring the use of Do(b-) red cells for transfusion.

Use of intraoperative auditory evoked potentials to preserve hearing in unilateral acoustic neuroma removal.

Twenty-two patients with unilateral acoustic neuromas and preoperative speech discrimination scores of 35% or more had intraoperative monitoring of the electrocochleogram (ECoG) using a transtympanic electrode, and of the brain-stem auditory evoked potentials (BAEP's) using scalp electrodes. Rapid feedback was provided about the status of the cochlear microphonics from the hair cells of the inner ear (CM of the ECoG), the compound action potential of the auditory nerve (N-1 of the ECoG or Wave I of the BAEP's) and the potentials from the lower brain stem (Wave V of the BAEP's). All patients had total removal of the tumor. In 21, the cochlear nerve was anatomically preserved, and 20 had good postoperative facial nerve function. Correlation of tumor size with postoperative hearing was as follows: discrimination scores of more than 35% in three of four patients with 1-cm tumors, two of eight with 1.5-cm tumors, two of six with 2- to 2.5-cm tumors, and one of four with tumors of 3 cm or more. Two other patients with 1.5-cm tumors had discrimination scores of less than 35%, and one patient with a 2-cm tumor had only sound perception. In two patients, the discrimination scores improved. At the end of the operation, all patients with hearing had a detectable N-1, and, when recorded, CM. All but one patient with no hearing had lost N-1, and CM was absent or reduced. Unless Wave V was unchanged, it was a poor predictor of postoperative hearing, and its absence did not preclude preservation of good hearing. The electrophysiological changes during each stage of the operation were analyzed and correlated with events during surgery. Areas in which there was an increased risk of loss of the potentials were determined. In some patients monitoring was unnecessary, because either there were no significant changes or the changes were abrupt and no recovery occurred. However, in other patients, monitoring alerted the surgeon to a possible problem and the method of dissection was altered. Possible mechanisms of hearing loss were suggested from the changes in the recordings.

Management of glottic stenosis.

Limited glottic stenosis may be managed by microlaryngoscopy. The extensive lesions should be managed by extralaryngeal procedures. The techniques described here give the patient adequate respiratory and vocal rehabilitation with early decannulation. The lack of response to the more conservative procedures should indicate exploration via laryngofissure with precise incision and excision of the scar tissue and without resection of other vital laryngeal structures. Defects should be covered with acceptable flaps or grafts.

Computed tomography: a three-dimensional study of the nasal airway.

1. Accurate volume measurement of the nasal airway based upon computed tomography images sequentially generated along the length of the airway is possible. 2. The cross-sectional area of the airway at any position along its length can be determined. 3. The most constricted part of the airway is not necessarily at the location of the turbinates. 4. Details of hard- and soft-tissue anatomy not otherwise discernible can be detected with computed tomography imaging.