Mode propagation in optical nanowaveguides with dielectric cores and surrounding metal layers.

The mode spectrum in an optical nanowaveguide consisting of a dielectric-core layer surrounded by two identical metal layers is investigated. A simple model based on mode matching to predict the properties of mode propagation in such optical nanowaveguides is proposed. It is shown that quasi-TM00 and quasi-TM10 modes supported by an optical microstrip line do not have a cutoff frequency, regardless of the size of the metal strips, the thickness of the dielectric slab, and the cross-sectional shape.

Role of neutrophil antigen NA1 in an infant with autoimmune neutropenia.

A nontransfused 14-month-old female infant was investigated for persistent neutropenia of eight months' duration, with absolute neutrophil counts ranging from 410 to 935 cu mm. The patient's sera reacted with neutrophils from her own peripheral blood, from normal donors, and from her mother, all these having the neutrophil antigen NA 1, but not with neutrophils from NA 1-negative donors, including the father. The autoantibody was detectable by capillary agglutination and by indirect immunofluorescence techniques but not by complement-dependent cytotoxicity.

Chemoprophylaxis of recurrent otitis media using trimethoprim/sulfamethoxazole.

This study was undertaken during the late fall, winter, and early spring months to determine the efficacy of daily trimethoprim/sulfamethoxazole (TMP/SMX) administration in the prevention of recurrent acute otitis media (RAOM) in a specific high-risk pediatric population. Twenty-one ambulatory patients, 10 in the study group and 11 in the control group, were selected from a medical university clinic and a local private practice. The study group receiving prophylactic therapy for six months suffered no recurrences, as compared with eight children suffering one recurrence each in the control group that was treated only acutely.

Bactericidal capacity of polymorphonuclear leukocytes from patients receiving theophylline therapy.

The capacity of polymorphonuclear leukocytes (PMNs) to kill Staphylococcus aureus strains 502 A was studied in 25 patients receiving theophylline therapy and in normal healthy controls. A significant difference in PMN bactericidal capacity was found between controls and patients with serum theophylline levels higher than 8 micrograms/ml, as determined by high-pressure liquid chromatography. The bactericidal capacity of PMNs from both the patient and control populations was reduced in the presence of theophylline levels above 8 micrograms/ml.