Dyskeratosis congenita Haematologic,cytogenetic, and dermatologic studies

In a family of 5 boys and 6 girls, 3 brothers have clinical dyskeratosis congenita. Teeth from 2 of the patients were taurodent, and mineral density of the enamel was significantly different from normal. The haematopoietic marrow was hypocellular and there was striking prominence of plasma cells having normal morphology; no granulomata were demonstrated. The decreased erythroid precursors in the marrow correlated with quantitatively reduced erythropoiesis demonstrated on ferrokinetic studies. Recurrent infections occurred but could not be related to neutropenia, and granulocytes and monocytes retained normal function. No abnormality was demonstrated in humoral or cellular immune mechanisms. While superficially similar, dyskeratosis congenita and Fanconi's anaemia are genetically distinct, being X-linked in the former and inherited as an autosomal recessive in the latter.     

Fractional Photothermolysis: Treatment of Facial and Nonfacial Cutaneous Photodamage with a 1,550-nm Erbium-Doped Fiber Laser

PURPOSE: To evaluate the safety and effectiveness of a novel nonablative 1,550 nm erbium-doped fiber laser in the treatment of facial and non-facial photodamaged skin. METHODS: 50 patients with mild to moderate cutaneous photodamage, rhytides, and dyspigmentation received 3 successive treatments at 3-4 week intervals with a 1,550 nm erbium-doped fiber laser (Fraxel, Reliant Technologies Inc., San Diego, CA). Clinical improvement of treatment areas was independently determined by two masked assessors' evaluations of comparative photographs at baseline and 3, 6, and 9 months post-treatment using a quartile grading scale. Patient satisfaction surveys were also obtained at each follow-up visit. RESULTS: Mean clinical improvement at 3 months for the face was 2.23 and 1.85 for non-facial skin (p<0.001). Mean improvement at 6 months was 2.10 for the face and 1.81 for non-facial skin (p<0.001). Mean improvement at 9 months was 1.96 for the face and 1.70 for non-facial skin (p<0.001). At least 51% to 75% improvement in photodamage at the 9-month follow-up was achieved in 73 and 55% of facial and non-facial treated skin, respectively. Side effects were limited to transient erythema and edema in the majority of patients. No prolonged pigmentary changes or scarring were observed. Patient satisfaction surveys mirrored the observed clinical effects. CONCLUSION: The nonablative 1,550 nm erbium-doped fiber laser is an effective treatment for facial and non-facial photodamage, rhytides, and dyspigmentation with a favorable recovery and side effect profile.     

Treatment effects on brain activity during a working memory task in obstructive sleep apnea

Positive airway pressure (PAP) is the most common form of treatment for obstructive sleep apnea (OSA). Treatment adherence is notoriously low, and holidays from treatment are common. To date, there is no literature on the effects of acute withdrawal from PAP treatment on the brain activity of individuals with OSA. Nine participants with OSA performed a 2‐Back verbal working memory paradigm during repeated functional magnetic resonance imaging (FMRI). Counterbalanced FMRI sessions were under conditions of PAP treatment (at least one consecutive week) or non‐treatment (for two consecutive nights). Treatment effects on 2‐Back‐related brain activity were significant, with greater deactivation in the right posterior insula and overactivation in the right inferior parietal lobule. The observed responses to PAP treatment withdrawal were more extreme in all regions of interest, such that 2‐Back‐related activity increased and 2‐Back‐related deactivation decreased further relative to the 0‐Back control task. The withdrawal of PAP treatment in effectively treated individuals with OSA might result in the need to reallocate resources in order to perform at the same cognitive level.     

Characteristics of Ventriculoatrial Conduction in Patients with Enhanced Atrioventricular Nodal Conduction

To study the characteristics of the ventriculoatrial conduction system in palienfs capable of rapid antegrade atrioventricuiar conduction, eiectrophysiologic studies were performed in 23 subjects capable of 1:1 atrioventricular conduction at atrial cycle lengths < 300 ms (Group I). and in 23 subjects with normal 1:1 atrioventricular conduction (Group II). During venfricular pacing, ventriculoatrial block at all cycle lengths was seen in 5/23 (22%) in Group I and in 7/23 (30%) in Group II patients (p = NS). In the remainder, the minimum ventricuar pacing cycle length maintaining 1:1 ventriculoatrial conduction was 359 ± 85 ms in Group I, compared to 444 ± 118 ms in Group II (p < .02). Both flat and exponential VA conduction interval curves, drawn as a function of pacing cycle length, were observed in both groups. Discontinuous ventricuioatrial conduction curves were seen in 5/18 (28%) Group I and 1/16 (6%) Group II patients (p = NS). In conclusion, retrograde ventriculoatrial conduction, when present in patients capable of rapid 1:1 atrioventricular conduction, is maintained at shorter cycle lengths than in patients with normal atrioventricular conduction. Quantitative, rather than qualitative, differences distinguish the two groups.