Psoriasis confined strictly to vitiligo areas – a Koebner‐like phenomenon?

Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.     

Developmental cellular electrophysiologic effects of propafenone on the rabbit atrioventricular node.

Transmembrane recordings and surface electrograms were used to evaluate the influence of propafenone on the cellular electrophysiology of isolated neonatal and adult rabbit atrioventricular node (AVN) preparations. An automatic interval of 863 +/- 82 ms (mean +/- SEM, n = 14) in neonates was found to be significantly shorter than the 1510- +/- 205-ms (n = 12) automatic interval observed in adults. Propafenone in a concentration of 5 x 10(-6) M significantly increased the automatic interval of neonatal pacemakers but not that of the adult preparations. These changes in automaticity produced by propafenone were not dependent on the adrenergic receptor-blocking action of the drug. The pacemaker escape time after overdrive pacing was also shorter in the neonate than in the adult. Propafenone prolonged the escape time of the neonatal tissues but not those of the adult. AVN refractory period, A-H interval, and antegrade Wenckebach rate were comparably increased in a concentration-dependent manner in both age groups. The maximum diastolic potential was decreased by propafenone in the neonatal atrionodal tissue but not in other regions of the AVN and not in any region of the adult AVN. Action-potential duration was increased in all regions of the AVN in both age groups. Action-potential amplitude and maximum upstroke velocity were decreased by propafenone in both age groups. Unlike other excitable tissues of the heart, the action-potential duration of AVN nodal cells increased with decreasing pacing intervals as the pacing interval approached the Wenckebach interval.(ABSTRACT TRUNCATED AT 250 WORDS)     

Work site health promotion research: to what extent can we generalize the results and what is needed to translate research to practice?

Information on external validity of work site health promotion research is essential to translate research findings to practice. The authors provide a literature review of work site health behavior interventions. Using the RE-AIM framework, they summarize characteristics and results of these studies to document reporting of intervention reach, adoption, implementation, and maintenance. The authors reviewed a total of 24 publications from 11 leading health behavior journals. They found that participation rates among eligible employees were reported in 87.5% of studies; only 25% of studies reported on intervention adoption. Data on characteristics of participants versus nonparticipants were reported in fewer than 10% of studies. Implementation data were reported in 12.5% of the studies. Only 8% of studies reported any type of maintenance data. Stronger emphasis is needed on representativeness of employees, work site settings studied, and longer term results. Examples of how this can be done are provided.     

Surgical management of dysrhythmias in infants and small children.

Surgery for cardiac dysrhythmias is infrequently reported in infants and children as compared with adults. This report reviews 55 infants and small children (age, less than or equal to 5 years) operated on during the interval July 1, 1984 to December 31, 1991 for Wolff-Parkinson-White Syndrome (41), atrioventricular node reentry (two), atrial automatic tachycardia (two), and ventricular tachycardia (nine). Ages ranged from 3 weeks to 71 (mean, 29) months. Associated congenital heart defects were present in five (10%). Indications for surgery included failure of medical therapy, life-threatening dysrhythmias, and more recently, failure of catheter ablation. There were no hospital or late deaths. One patient sustained perioperative central nervous system injury. Surgery was successful in 52 of 55 (94.5%) (Wolff-Parkinson-White, 38/41 (93%); atrioventricular node reentry, 2/2 (100%); atrial automatic tachycardia, 3/3 (100%); ventricular tachycardia, 9/9 (100%). Ventricular function returned to normal in all 12 patients in whom it was abnormal before operation. Thus, surgical ablation is highly successful in the management of various forms of refractory or life-threatening dysrhythmias in infants and small children. Catheter ablation techniques require significant fluoroscopic time, are more difficult in infants, and as yet do not have adequate long-term follow-up. Accordingly, surgery may continue to play a role in this particular group of patients.     

Subcutaneous lidocaine affects inducibility in programmed electrophysiology testing in children: a follow-up study.

Invasive cardiac electrophysiology testing during cardiac catheterization requires local anesthesia at the point of entry for the catheters. Frequently, lidocaine is employed for this purpose. A prospective study completed in 1990 indicated that subcutaneous administration of lidocaine adversely influenced the inducibility of arrhythmias in pediatric patients. Upon completion of that study, lidocaine concentration was reduced from 1% to 0.5%, and extra caution was taken to avoid deep penetration during administration. A follow-up, prospective study was performed to evaluate inducibility under these changed conditions. Because the depressant effect of lidocaine on inducibility was age- and weight-related, the second study group was required to have statistically indistinguishable age and weight distributions from the first group to eliminate these variables as factors in inducibility. A total of 177 subjects were collected in the second group before a periodic random computer match with the first group produced 99 individuals with the required age and weight distributions. Analysis of the electrophysiology tests in the second study revealed that: (1) incidence of inducibility was higher in the second group (58 of 99 versus 43 of 99, p < 0.05); (2) average lidocaine dose per kilogram was lower (1.8 mg/kg versus 3.28 mg/kg, p < 0.0001); (3) average lidocaine serum concentration was also lower (0.58 micrograms/ml versus 1.47 micrograms/ml, p < 0.0003); (4) in contrast to the first study, neither lidocaine dose nor serum concentration had any effect on inducibility. We conclude that the new procedures for lidocaine administration effectively removed lidocaine as a factor in inducibility.     

Circannual variation in lymphocyte subsets, revisited

BACKGROUND: Circadian and circannual variations in lymphocyte subsets, especially CD8+ T-lymphocytes, have been reported. This study focuses on CD4+ T-lymphocyte seasonal variation over a 6-year 8-month period. STUDY DESIGN AND METHODS: Lymphocyte subsets were quantitated monthly for four healthy individuals from 1986 through 1992 as part of a flow cytometry quality-control program. RESULTS: In general, there were no significant seasonal changes in the total number of white cells or in total lymphocyte counts. The absolute numbers of CD4+ T-lymphocytes were lowest in summer when the CD8+ T-lymphocytes were highest. Mean CD4+ T-lymphocyte counts were 846, 967, 618, and 695 per microL for Subjects 1 through 4, respectively, in winter and 432, 670, 355, and 766 per microL, respectively, in summer. Two healthy subjects had CD4+ T-lymphocyte counts lower than 300 per microL on one or more occasions during the study period. In three of the four subjects, the percentage of B-lymphocytes in winter was almost double that in summer. In one of the four subjects, no circannual rhythm was observed in these lymphocyte subpopulations. CONCLUSION: The seasonal variation in CD4+ T- lymphocyte counts demonstrated in three healthy individuals over almost 7 years is again of interest in light of renewed consideration of using surrogate tests, such as CD4+ T-lymphocyte counts, to screen for AIDS- like diseases that may be in the blood supply.     

Lack of age-related differences in temporal lobe volume of very healthy adults.

PURPOSETo evaluate age-related differences in temporal and supratemporal brain regions in carefully selected, very healthy men 19 to 92 years of age.METHODSMR quantification of brain regions used image segmentation into cerebrospinal fluid and brain matter based on nonlinear modeling of pixel intensity distributions.RESULTSThere was a significant age-related decrease (approximately 1% per decade) of posterior frontal lobe volume, but not of temporal lobe volume. The mean volume of the right temporal lobe was significantly greater than the left, and this relation did not change with age.CONCLUSIONIn very healthy aging, the volume of the temporal lobes remains constant over the age range of human life.