Effects of the optical isomers of verapamil on electrophysiological properties of the heart in conscious dogs.

We compared the cumulative dose-response relations of verapamil (0.1, 0.2 and 0.4 mg kg(-1)) in different R/S enantiomer ratios (100/0, 90/10, 80/20, 50/50 and 20/80) on the electrophysiological and hemodynamic characteristics of the heart using the conscious dogs. A reduction of mean arterial pressure occurred with 20R/80S producing a 3-times greater decrease than 100R/0S, but an increase in heart rate occurred with 20R/80S producing a 9-times greater increase than 100R/0S. Increased heart rate was concurrent with decreased mean arterial pressure most prevalent with a higher ratio of S-isomer that produced a greater reduction in mean arterial pressure and increase in heart rate at lower overall verapamil doses. Atrio-ventricular conduction time increased 3-5 min after each infusion, with 20R/80S producing a 4-times greater effect than 100R/0S. These results indicate that the peripheral and cardiac electrophysiologic properties of various nonracemic verapamil mixtures are mainly attributable to the concentration of S-isomer.

Phylogenetically distinct hantavirus implicated in a case of hantavirus pulmonary syndrome in the northeastern United States.

Hantavirus pulmonary syndrome (HPS) is an acute respiratory illness with high mortality. It is caused by a newly described New World hantavirus known as Four Corners virus (FCV). Nearly all cases of HPS have occurred in the western United States. The etiologic agents in those cases have been closely related to each other, based upon comparisons of their genetic sequences. We have molecularly cloned the S genomic segment of a hantavirus (Rl-1) implicated in a case on HPS in the northeastern United States. Nucleotide sequence analysis shows that the Rl-1 virus has many similarities to FCV, but is clearly distinct from the western forms of that virus. These data suggest that HPS can be caused by multiple agents that together form a distinctive evolutionary clade.

Staff nurse leadership and professional growth in the mentor role.

Nurses frequently commit only for a short term to medical/surgical nursing to pursue opportunities in more specialized areas. The implementation of a mentorship program for orientation incorporates professional role development and leadership opportunities for the staff nurse serving in the mentor role. The mentorship has resulted in a mutually beneficial mentor-orientee relationship. Practical triumphs for a successful mentorship as well as ongoing challenges are identified.

Primary cerebellopontine progressive multifocal leukoencephalopathy diagnosed premortem by cerebellar biopsy.

A subacute progressive cerebellar brainstem syndrome developed in a patient with systemic lupus erythematosus in remission. Cerebellar biopsy documented the diagnosis of progressive multifocal leukoencephalopathy (PML). Data from this patient and 10 others in the literature emphasize the need to consider this diagnosis when ataxia develops in any patient with underlying malignancy, chronic infection, or other disease that involves immunological incompetence. Although the ataxic form of PML is not of nosological relevance, early diagnosis may eventually have therapeutic importance.

Crohn disease of penile and scrotal skin.

Genital cutaneous involvement with Crohn disease is an uncommon complication which has been described only recently. A case is presented of a young man with Crohn disease involving the penile and scrotal skin four years after total colectomy for Crohn disease. The histopathology and management are discussed. While the complications of Crohn disease vary in the literature, we believe involvement of the skin of the genitalia is uncommon.