Mites in the environment of cases of Norwegian scabies

Three cases of Norwegian scabies diagnosed in Glasgow hospitals within 1 year each caused widespread outbreaks of papular eruptions amongst the patients and staff, followed later by a few cases of classical scabies. Symptoms and timing suggested that these infections were caused mainly by immature mites derived by personal contact and possibly by contact with infected cuticular fragments which were abundant in the environment of the three patients. To control a ward epidemic, isolation of the Norwegian scabietic should be followed by environmental and then by personal disinfestation.     

Long-term dimensional stability of three current elastomers

The long-term dimensional stability of three non-aqueous elastomeric impression materials, a silicone, a polyether and a polysiloxane, were investigated. The testing apparatus was an A.D.A. specification No. 19 test block and mould. The impressions were measured by the use of a travelling stage reflecting microscope and a Quantimet 720 Image Analyzing computer at time zero and again at 4, 24 and 48 h, and at 1, 2, 3 and 4 weeks. Impressions poured immediately had the greatest accuracy for all the materials. The polysiloxane (0.025 mm) and polyether (0.033 mm) showed very little change in dimension after 4 weeks when compared to the test block. However, the silicone showed significant change at 4 h (0–14 mm) and 0–2 mm after 4 weeks. After 4 weeks the polysiloxane maintained the best surface detail, the polyether was adequate but the silicone lost much of its detail in as little as 24 h. The reasons for these findings are discussed.     

Humoral immunity in stage I mycosis fungoides: an increased incidence of lymphocytotoxic antibodies

Thirteen patients with stage I mycosis fungoides (MF) were studied for the presence of circulating autoantibodies including cold-reactive lymphocytotoxic antibodies (LCA), antinuc-lear antibodies and rheumatoid factor antibodies to common food antigens, bovine gamma globulin and casein; and immune complexes as measured by cryoglobulins and I¹²⁵ Clq binding. A significantly increased incidence (11/13) of LCA was found in the MF patients, and this may be related to the alterations in subpopulations of T cells seen in these patients. No significant increase in any other test was noted. There was no evidence of a diffuse hyperactivity of the humoral immune system as seen in systemic lupus erythematosus, which has a similar imbalance of T cell subpopulations.     

The Congenital 'Magnesium-Losing Kidney'

A 39-year-old man with a lifelong history of tetany and hypocalcaemiawas found to have hypomagnesaemia (0·29 mmol/l) due torenal magnesium loss. His asymptomatic 29-year-old brother hada similar disorder. Both were infertile and had severe oilgospermiabut normal endocrine function. They had medullary nephrocalcinosisand glomerular filtration rate was reduced. Renal biopsy showedpatchy interstitial fibrosis and some glomerular sclerosis.Electron microscopy showed thickened basement membranes in damagedglomeruli and in tubules in areas of fibrosis. Tests of renaltubule function were normal. Hypocalcaemia and tetany were correctedby oral magnesium supplements which raised the serum magnesiumlevel to around 0.54 mmol/l.     

Stent Dilation of Superior Vena Cava and Innominate Vein Obstructions Permits Transvenous Pacing Lead Implantation

The purpose of this study was to assess the feasibility of stent dilation of venous obstructions/occlusions to permit transvenous pacing lead implantation. Innominate vein or superior vena cava (SVC) obstruction may preclude the implantation of transvenous pacing leads. Patients with d-transposition of the great arteries, after a Mustard or Senning procedure, and children with previously placed transvenous pacing leads are at higher risk for this vascular complication. From May 1993 to January 1996, eight pediatric patients who underwent transvenous pacing lead implantation or replacement were found to have significant innominate vein or SVC obstruction or occlusion. Utilizing in-travascular stents, a combined interventional and electrophysiological approach was used to relieve the venous obstruction and to permit implantation of a new transvenous pacing lead. Two patients had complete SVC occlusion requiring puncture through the obstruction with a transseptal needle. Vessel recanalization was achieved with balloon dilation and stent implantation. The remaining six patients had severe venous obstruction with a mean minimum diameter of 3.1 ± 3.3 mm. The mean pressure gradient across the obstructed veins was 8.6 ± 7.3 mmHg. Following implantation of 15 Palmaz P308 stents in eight vessels, the mean diameter increased to 14.2 ± 1.9 mm and the mean pressure gradient across the stented vessels decreased to 1.0 ± 2.0 mmHg, A transvenous pacing lead was implanted successfully through the stent (s) immediately or 6–8 weeks later. Innominate vein and SVC obstruction can be safely and effectively relieved with intravascular stents and permit immediate or subsequent transvenous pacing lead implantation.     

Early Follow-Up of Lead Performance in Atrioventricular Sequential Systems

Recent developments in pacemaker technology led us to report our initial and follow-up assessment of atrioventricular (A-V) sequential systems in 50 consecutive patients. Primary indications for pacing were sinus node dysfunction or A-V block. Leads were introduced through the subclavian vein. Atrial J-tined leads (27 silicone, 19 urethane) were positioned in the atrial appendage or stump in 46 patients, and coronary sinus or Bisping leads were placed in 4 patients; all 50 patients had tined ventricular leads. A Medtronic 5992 generator was placed in 35 patients and an Intermedics 259-01 generator in 15. Median implantation time was 105 minutes. Complications requiring reoperation in 409 patient-months of follow-up included lead retraction (one patient), phrenic nerve stimulation (one), pseudofracture (one), and atrial lead-induced "cross talk" (one). Monthly telephone transmission confirmed atrial capture in 35 patients and loss of capture in 1; the remainder had no identifiable P wave. Ventricular capture was confirmed in all. Postimplant and follow-up checks showed good stability of lead positions. We conclude that these systems have a low incidence of problems in short-term follow-up.     

Atrial Arrhythmias During Chronic Follow-Up of Surgery for Complex Congenital Heart Disease

After surgery for complex congenital heart disease, clinically important atrial tachyarrhythmias have a higher than normal incidence if sufficiently large regions of conduction block occur within the atria, especially in the presence of hemodynamic alterations. Sinus bradycardia may result from direct damage to the sinus node and its blood supply. Historical data have identified patients who have undergone the Mustard or Senning operations for dextrotransposition of the great vessels and the Fontan operation in cases of functional single ventricle as being at great risk for atrial tachyarrhythmias. These arrhythmias are especially poorly tolerated when there are co-existing hemodynamic alterations and are an important source of morbidity and mortality. Until recently, treatment strategies have been limited to antiarrhythmic drugs, bradycardia pacing, and—in suitable patients—antitachycardia pacing, often in combination. Amiodarone has been the most efficacious drug, but has only been of moderate value because of extracardiac side effects. Radiofrequency ablation of the atrial regions critical to reentrant circuits, which was discovered to be of value in patients with atrial flutter and a normal heart is being applied to this diverse group of patients. Early results are promising, but the Fontan operation patients are especially challenging because of early recurrences of apparently new reentrant circuits. Progress in this area will likely come from newer surgical techniques that prevent the milieu for atrial reentry and from multidimensional mapping systems for our current patients.