Demonstration of Isoantigenic Receptors on Human Epidermal Cells and Established Cell Lines

This paper describes mixed agglutination and serum absorption experiments for the demonstration of A, B, H, M, N, D, C, E, c and e isoantigens inhuman epidermal cells and cultured cells. It was found that only A, B andH antigens are present on human epidermal cells and that this does not appearto be related to the secretor status of the donor. The same antigens were alsoexamined on six different established human cell strains (HeLa, EE, ERK-1,Maben, Chang conjunctiva, Chang liver), and one established mouse cellstrain (L). It was found that the H antigen persists in established human cellcultures. The M antigen which is not seen in normal epithelial cells can bedemonstrated on HeLa cells by mixed agglutination reaction and by absorption experiments. Guinea pig antisera against established cell lines of humanorigin were found to contain a small fraction of agglutinins with H specificity,but no anti-M, anti-N or anti-Rh agglutinins.

Submitted on December 30, 1963 Accepted on April 17, 1964     

Cell Antigens and Cell Specialization. III. On the H Antigen Receptors of Human Epidermal Cells

This article describes the application of the mixed agglutination method todemonstrate the H antigen receptors on human A₁, A₂, B and O epidermalcells, and also the presence of A and B antigen receptors in different spatiallocations than the H receptors in A and B epidermal cells.

Submitted on April 16, 1963 Accepted on June 18, 1963     

Use of Single Lead VDD Pacing in Children

The development of transvenous ventricular pacing leads with proximal electrodes capable of atrial sensing and the recent availability of smaller generators has created the opportunity to treat children with complete AV block and normal sinus node function with a transvenous single lead VDD pacing system. Studies in adults have demonstrated this system to be efficacious with low complication rates. Transvenous single lead VDD pacemakers were implanted in ten children, aged 5–15 years, between December 1993 and April 1996, in our institution. The indications were complete AV block with severe bradycardia in 5 patients, second-degree or complete A V block following congenital heart surgery in 3, complete A V block with long QT syndrome in 1, and second-degree AV block and syncope in 1. There were no complications related to the procedure in any case. P and R wave amplitudes were measured and thresholds were determined intraoperatively on all patients. Amplitudes and thresholds were remeasured on seven patients with a mean follow-up of 17 months; Holter monitors were performed on seven patients with a mean follow-up of 16 months. P and H wave amplitudes were generally diminished at follow-up compared to initial values but remained within an acceptable range for all patients. Four patients required reprogramming after pacemaker insertion, 1 received an atrial lead for dual chamber pacing, 1 required repositioning for lead dislodgment. and 1 patient required a new lead for an inadequate ventricular pacing threshold. No patient had evidence of failure to sense or capture as evaluated by Halter monitoring at last follow-up. Single lead VDD pacing systems can be successfully used in properly selected children with high degree or complete AV block with normal sinus node function.     

Crystal and molecular structure of Destruxin B

The cyclic hexadepsipeptide mycotoxin Destruxin B. produced by Metarrhizium anisopliae. crystallizes in the orthorhombic space group P2₁2₁2₁, with a = 11.010(2)Å, b = 14.679(5)Å, c = 21.273(7)Å and Z = 4. The structure was solved by direct methods and refined by least-squares technique to a final unweighted R value of 0.051, for 3361 reflections with I > 3σ(I). The backbone of the peptide is asymmetric and is made of 5 trans peptide and ester units and 1 cis peptide unit. The backbone conformation of this cyclic depsipeptide is very similar to that of Roseotoxin B, an analogous mycotoxin produced by Trichothecium roseum. The conformation in the crystalline state also correlates well with the solution conformation, as reported from proton n.m.r. studies. The crystal packing is directed by van der Waals contacts.     

The Mechanism of Flutter Electrical Alternans

We have had the opportunity to observe the occurrence of flutter electrical alternans in which two distinct populations of flutter waves are present and which alternate in 1:1 and 2:1 patterns. The flutter alternans whether 2:1 or 3:1, was concordant with the pattern of preceding ventricular conduction (ventriculophasic variation). This concordance occurred reproducibly and remained consistent. Our example of flutter allernans probably represents mechanical artefact caused by catheter movement during ventricular mechanical systole. We reproduced this pattern consistently at a slower rate during coronary sinus pacing. These findings appear to suggest an explanation for certain types of so-called atrial flutter electrical alternans.     

Rate-Adaptive Cardiac Pacing in Children Using a Minute Ventilation Biosensor

YABEK, S.M., ET AL.: Rate-Adaptive Cardiac Pacing in Children Using a Minute Ventilation Biosensor. Chronotropic integrity is required for a normal cardiac output response to exercise. We evaluated a rate-adaptive ventricular demand pacemaker (Telectronics, META-MV) which uses minute ventilation as the sensed physiological variable for adjusting pacing rate, in seven young patients with a mean age of 11.4 years. All patients had clinically significant bradycardia related to complete heart block (n = 4) or sinus node dysfunction (n = 3). For the entire group, paced heart rates increased from 70 ± 10 beats/min to 151 ± 19 beats/min with exercise testing. The onset of rate adaptation took < 30 seconds. Changes in paced rate were linearly related to workload, VO₂ (5.9 to 20.7 mL/min/kg) and minute ventilation (8–65 L/min). The decline in pacing rate after exercise was related directly to the gradual decrease in minute ventilation and VO₂. Our data show that minute ventilation closely and accurately reflects the metabolic demands of varying workloads in children and can be used to achieve physiological, rate-adaptive pacing.     

Late Complications in Patients with Pectoral Defibrillator Implants with Transvenous Defibrillator Lead Systems: High Incidence of Insulation Breakdown

As the majority of ICDs with transvenous leads are now implanted in tbe pectoral region, complications associated with the technique are being identified. To determine the incidence of lead complications in patients with transvenous defibrillator leads and ICDs implanted in the pectoral region, 132 unselected consecutive patients with transvenous defibrillator leads had ICDs implanted in the pectoral region. Three lead systems were used:(1) lead system 1(45 patients) consisted of a transvenous pacing sensing lead and a superior vena cava coil with a submuscular patch used for defibrillation;(2) lead system 2(36 patients) utilized a CPI Endotak lead system: and(3) lead system 3(51 patients) utilized a Medtronic Transvene lead system. Patients were followed for 3–54 months(cumulative 2,269, mean 18 months). The average duration of follow-up with the three systems was 32, 12, and 11 months, respectively. At 30 months follow-up, all three lead systems had a low incidence of complications. However, there was a 13% overall incidence(45% actuarial incidence) of erosion of the insulation of the pacing sensing lead of system 1 at 50 months of follow-up. All lead complications were seen in patients with ICDs whose weights were > 195 g and volumes > 115 cc. The erosion was probably a consequence of the pressure by the large ICD against the lead in the pectoral pocket. Follow-up with lead systems 2 and 3 is relatively short(average 12 months) but no lead erosions were seen. Pectoral implantation of ICDs with long transvenous leads and large generators is associated with a moderate risk of late complications in the form of insulation breaks caused by pressure of the generator against the leads. The use of less redundant leads coupled with smaller ICDs will probably eliminate this complication.     

REITER'S SYNDROME-LIKE PATTERN IN AIDS-ASSOCIATED PSORIASIFORM DERMATITIS

Background. The prevalence of psoriasiform dermatitis in HIV-infected patients is similar to that in the general population, but its clinical severity and the immunosuppression in these patients pose special problems of therapeutic management. Furthermore, a distinctive clinical pattern has been reported in some cases. In order to assess these features in our clinical setting, we have done a retrospective study on the clinical records of all human immunodeficiency virus (HIV)-positive patients with psoriasiform dermatitis requiring systemic treatment. Methods. The clinical records were reviewed of seven HIV-positive patients who were referred between 1988 and 1994 to a University Hospital Dermatology Department from an HIV-clinic because of psoriasiform dermatitis, resistant to topical treatment. Results. The clinical appearance was rather uniform, with the following common features: facial seborrhea, flexural and acral involvement, with pustulosis of the palms and soles, and frequent arthritis. Lesions appeared in nonterminal stages of acquired immunodeficiency syndrome (AIDS). Three patients developed cutaneous lesions after the diagnosis of HIV infection was made and showed the most severe clinical involvement and arthritis. Etretinate, followed by RePUVA, proved to be the most effective systemic therapy prescribed, with only rare adverse effects. Methotrexate was shown to be effective, but its use was accompanied by hematologic toxicity. Cyclosporine A treatment was moderately effective and was not associated with progression of AIDS. Conclusions. A characteristic Reiter-like clinical picture was observed in AIDS-related psoriasiform dermatitis. Etretinate and RePUVA were effective and safe in controlling the lesions. Physiopathologic mechanisms involved in the development of AIDS-related psoriasis might provide an explanation for the outstanding similarity of the clinical pattern in those patients.