Hemoglobin M equon beta 41 (C7) phenylalanine leads to tyrosine

A severe hemolytic crisis was observed in a 34-yr-old female of English- Irish extraction following a viral illness treated with acetaminophen. Heinz bodies and heat instability were present only during a transient hemolytic event. A challenge dose of acetaminophen caused no detectable hematologic abnormality. Structural studies of the hemoglobin during hemolysis and again after complete recovery localized the abnormality to tryptic peptide beta Tp-5, and automated sequencing of I 125-labeled beta chains indicated a replacement of phenylalanine (C7) beta 41 by tyrosine. Substitution of the next residue, phenylalanine (CD1) beta 42 by serine (Hb Hammersmith), has resulted in chronic severe Heinz body hemolytic anemia. The lack of chronic anemia in the present disorder may reflect the different relationships of beta41 and beta 42 and/or the similarities in volume and hydrophobicity of tyrosine and phenylalanine. It is suggested that substitution of tyrosine for phenylalanine in Hb Mequon may disturb the critical environment around the heme group and render it susceptible to oxidative denaturation in the presence of infections and/or drugs.     

FENTANYL THERAPY CONTROLS AUTONOMIC HYPERACTIVITY IN TETANUS

SUMMARY This report describes the use of fentanyl in severe tetanus after failure of established therapeutic modalities (heavy sedation, neuromuscular blockade and ventilation). Cardiovascular instability accompanying severe tetanus secondary to sympathetic overactivity and raised catecholamine levels is associated with a mortality of over 50%.¹ In this clinical situation, a variety of drugs with a primary or secondary action on the cardiovascular system has been used with varying success. The following case of severe generalised tetanus in the adult associated with autonomic hyperactivity, was successfully managed with large doses of intravenous fentanyl.     

Comparative study of the reactivity, safety and immunogenicity of "Havrix" inactivated hepatitis A vaccine

This paper sums up the results of controlled field clinical trials of adult and childhood variants of Harvix, inactivated vaccine from hepatitis A. The vaccine is weakly reactogenic and safe. After a single injection of Harvix-1440 vaccine to adults the percentage of seroconversions in previously seronegative individuals was 80.6%, with the mean geometrical antibody titer 119 mIU/ml. In children aged 3-10 years the percentage of seroconversions after a single injection of Harvix-720 vaccine was 100%, the mean geometrical of antibody titer being 427 mIU/ml. Results of laboratory control and field clinical trials recommend both variants of Harvix vaccine for prevention of hepatitis A in the Russian Federation.     

Clinical experience with a new detection algorithm for differentiation of supraventricular from ventricular tachycardia in a dual-chamber defibrillator

INTRODUCTION: Inadequate therapy for supraventricular tachyarrhythmias (SVT) is a frequent problem of implantable cardioverter defibrillators (ICD). Dual-chamber ICDs have been developed to improve discrimination of SVT from ventricular tachycardia (VT). We investigated the positive predictivity, sensitivity, and specificity of a new algorithm, the SMART detection trade mark algorithm, incorporated in the Phylax AV (Biotronik) dual-chamber ICD. METHODS AND RESULTS: Two hundred nine patients (185 men, age 64 +/- 11 years) received a Phylax AV ICD with SMART detection trade mark activated. In 138 of these patients, 1,245 sustained tachycardia episodes with a detailed electrogram were stored in the device during a follow-up period of 10 +/- 6 months. Episodes were correctly classified as ventricular fibrillation (VF, n = 178) in 52 patients, VT (n = 641) in 98 patients, and SVT (n = 385) in 48 patients by the algorithm. Forty-one true SVT episodes (3.3%) were misclassified as VT: atrial fibrillation (n = 7) and flutter (n = 1), sinus tachycardia (n = 12), and other SVT (n = 21). The positive predictivity for VF/VT was 94.5% (95% CI 92.7-95.8) uncorrected and 94.5% (95% CI 92.9-95.8%) corrected with the generalized equation estimation (GEE) method. The positive predictivity for SVT was 100%. The specificity was 88.9% (95% CI 85.6-91.6%) uncorrected and 89.0% (95% CI 85.6-91.6%) corrected with the GEE method with a sensitivity of 100%. CONCLUSION: The SMART detection trade mark algorithm was safe and reliable for the detection of all ventricular tachycardias. Although its specificity was high, it should be improved with regard to SVT to avoid inappropriate ICD therapies.     

Immune response to different tick-borne encephalitis vaccines as revealed by lymphocyte blast transformation and virus neutralization tests

Immunological memory has been demonstrated in lymphocytes of persons vaccinated against tick-borne encephalitis (TBE). Stimulation indices (SI) of lymphocytes in response to TBE virus antigens in lymphocyte blast transformation test increased after complete vaccination course with the commercial vaccine; by this time, sera of vaccinees contained virus neutralizing antibodies. The concentrated purified vaccine had a higher immunogenic activity, as evidenced by increased SI and virus neutralizing antibodies (NA) in the vaccinated subjects already after the first and second vaccinations.     

Heterogeneity of monospecific antibodies to the hemagglutinin of influenza virus H3N2 studied by radioimmunological analysis

Heterogeneity of antibodies against influenza virus hemagglutinin has been confirmed. Various subpopulations of antibodies to the A/Khabarovsk/15/76 hemagglutinin were demonstrated some of which showed greater affinity to MRC-11 hemagglutinin than to the HA of the strain inducing this antibody synthesis. Apparently subpopulations of antibodies with low affinity to their "own" epitopes in the hemagglutinin-immunogen may develop which, however, may show a sufficiently high affinity to these epitopes in hemagglutinins of other strains.