Biomedical subjects

R Kessinger

Publications and source records attributed to R Kessinger.

3 recordsLinked to original sources

PubMed2002

Warm autoimmune hemolytic anemia with mimicking anti-c and -E specificities.

An 18-month-old male was admitted to a hospital with a hemoglobin of 4.1 g/dL and a reticulocyte count of 53 percent. There was no history of prior transfusion. Serologic evaluation revealed the presence of both a positive direct antiglobulin test (DAT) and an indirect antiglobulin test (IAT). The patient's red blood cells (RBCs) typed as group A, C-D-E-c+e+ (cde/cde). Evaluation of the IAT revealed the presence of anti-c and anti-E. All other major antibodies were ruled out. Upon adsorption of the patient's serum with ficin-treated Cde/Cde RBCs, both antibody specificities were adsorbed; however, the antibodies were not adsorbed with native (untreated) Cde/Cde RBCs. Furthermore, the autoantibody was not adsorbed by Rhnull cells, thereby suggesting Rh specificity. The serum was incompatible with cde/cde RBCs and compatible with Cde/Cde RBCs. The patient was successfully transfused with Cde/Cde RBCs followed by resolution of his anemia, as evidenced by an increased and stable hemoglobin. It was concluded that the autoantibody had mimicking anti-c and -E specificities. This is a report of an unusual case of autoimmune hemolytic anemia because the Rh autoantibody appeared to have dual mimicking specificities, and the patient's RBCs were antigen negative for one of the antibody specificities, i.e., anti-E.

Journal Article↗

PubMed2000

Selective electrolytic removal of bis(alkoxycarbonyl)methano addends from C60 bis-adducts and electrochemical stability of C70 derivatives

The novel mixed bis-adducts of C60, (+/-)-4-(+/-)-8 and 9, with a bis(ethoxycarbonyl)methano addend (Bingel addend) and a second addend ([1,2]benzeno, but[2]eno, methaniminomethano, or diarylmethano) bridging 6,6-closed bonds of the carbon sphere were synthesized in two-step reactions. Each bis-adduct was exhaustively electrolyzed at the potential of the second fullerene-centered reduction step, resulting in the selective removal of the Bingel addend (retro-Bingel reaction) to produce the corresponding mono-adducts, which were isolated in yields of over 60%. These results open up the possibility of using the Bingel addend as a temporary protecting and directing group in the construction of multiple adducts of C60 with unusual addition patterns. The Bingel-type mono-adduct of C70 10 and the constitutionally isomeric bis-adducts 11, (+/-)-12, and (+/-)-13 were also included in this investigation. A large difference in the electrochemical behavior between C70 bis-adducts and the corresponding C60 derivatives was observed. Thus, the intramolecular "walk-on-the-sphere" isomerization which occurs readily with Bingel-type bis-adducts of C60 under the conditions of two-electron controlled potential electrolysis (CPE) is only a minor reaction pathway in the series of C70 derivatives. The latter preferentially undergo retro-Bingel reaction.

Journal Article↗

PubMed1977

A hearing aid malfunction detection unit.

A system is described, the Hearing Aid Malfunction Detection Unit (HAMDU), that electrically checks for proper operation of several aspects of hearing aid function. HAMDU is a miniature, add-on device which performs a check of hearing aid operation about every half hour, and which indicates malfunction by means of a highly visible, electrically tripped indicator. Functions checked include battery voltage, gain, distortion and noise, and continuity of the receiver cord. In addition, the indicator will be tripped if the hearing aid is turned off. HAMDU is small, low in cost, can be adapted to most body aids, and has no effect on hearing aid performance. The primary features of the system are that the hearing aid is checked periodically throughout its use, and the aid does not have to be removed from the wearer. The unit is designed specifically for body type hearing aids worn by children.

Electromagnetic Phenomena↗