Ventilatory muscle support in respiratory failure with nasal positive pressure ventilation

Long-term intermittent mechanical ventilation results in improvements in ventilatory performance and clinical status between ventilation sessions in patients with chronic respiratory failure. The application of intermittent positive pressure ventilation through a nasal mask (NPPV) is a simple, noninvasive method for the provision of chronic intermittent ventilatory support. We investigated the effects of NPPV on inspiratory muscle activity in three normal subjects and nine patients with acute or chronic ventilatory failure due to restrictive (four subjects) or obstructive (five subjects) respiratory disorders. NPPV resulted in reductions of phasic diaphragm electromyogram amplitude to 6.7 +/- 0.7 percent (mean +/- SEM) of values obtained during spontaneous breathing in the normal subjects, 6.4 +/- 3.2 percent in the restrictive group, and 8.3 +/- 5.1 percent in the obstructive group. Simultaneous decreases in activity of accessory respiratory muscles were observed. The reductions in inspiratory muscle activity were confirmed by the finding of positive intrathoracic pressure swings on inspiration in all subjects. With NPPV, oxygen saturation and PCO2 remained stable or improved as compared with values obtained during spontaneous breathing. These results indicate that NPPV can noninvasively provide ventilatory support while reducing inspiratory muscle energy expenditure in acute and chronic respiratory failure of diverse etiology. Long-term assisted ventilation with NPPV may be useful in improving ventilatory performance by resting the inspiratory muscles.     

Lower limb salvage in a 7-month-old infant using free tissue transfer

Free flap reconstruction in infants is extremely rare. A seven-and-a-half-month-old male infant sustained an extensive soft tissue defect on his left knee caused by extravasation of an intraosseous arterenol infusion. A free latissimus dorsi flap was successfully performed for soft tissue reconstruction. Indications, advantages, and outcome of the procedure are discussed.     

Molecular-level HLA mismatch is associated with rejection and worsened graft survival in heart transplant recipients – a retrospective study

The aim was to evaluate the association of molecular-level human leukocyte antigen (HLA) mismatching with post-transplant graft survival, rejection, and cardiac allograft vasculopathy (CAV). We retrospectively analyzed all primary cardiac transplant recipients between 01/1984-06/2016. 1167 patients fulfilled inclusion criteria and had HLA typing information available. In 312 donor-recipient pairs, typing at serological split antigen level was available. We used the Epitope MisMatch Algorithm to calculate the number of amino acid differences in antibody-verified HLA eplets (amino acid mismatch load (AAMM)) between donor and recipient. Patients with a higher HLA-DR AAMM load had inferior 1-year graft survival (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.01–1.28). The HLA-AB AAMM load showed no impact on graft survival. In the subgroup with available split-level information, we observed an inferior graft survival for a higher HLA-DR AAMM load 3 months after transplantation (HR, 1.22; 95% CI, 1.04–1.44) and a higher risk for rejection for an increasing HLA-AB (HR, 1.70; 95% CI, 1.29–2.24) and HLA-DR (HR, 1.32; 95% CI, 1.09–1.61) AAMM load. No impact on the development of CAV was found. Molecular-level HLA mismatch analysis could serve as a tool for risk stratification after heart transplantation and might take us one step further into precision medicine.     

ArteFill: a third-generation permanent dermal filler and tissue stimulator

The technical and physiologic shortcomings associated with prior generations of polymethylmethacrylate (PMMA) dermal fillers have been reduced significantly since their original market introduction in 1989. For example, the PMMA microspheres in the third-generation product ArteFill meet the new limit set by the FDA of less than 1 particle below 20 micrometers per 100 microspheres (< 1% by the number). Therefore, it is expected that the already low granuloma rate following injections with second-generation product Artecoll (1:5000) will be reduced further with injections of ArteFill. In the authors' experience, both Artecoll and ArteFill have proven to be safe, predictable, and effective dermal fillers. It is anticipated that Artefill will receive FDA approval in late 2006 and will be marketed internationally.     

PMMA-Microspheres (Artecoll) for Long-Lasting Correction of Wrinkles: Refinements and Statistical Results

The corium is diminished to about half of its thickness in skin defects and wrinkles. All biological materials that increase the thickness of the corium are resorbed within a certain time. Therefore, a lasting effect can be achieved only with nonresorbable synthetic substances. Artecoll consists of microspheres of 30–40 μm in diameter, of exceptional surface smoothness, purity, and homogeneity related to PMMA. These microspheres are suspended in atelocollagen which serves as a vehicle for subdermal implantation. Due to its smooth surface and consequential lack of electrical charges, each single microsphere is immediately encapsulated with the patient's own collagen fibers, thus preventing dislocation. Within 3 months, collagen (making up 75% of Artecoll) is replaced by the body's own connective tissue. The microspheres (25% of Artecoll) serve merely as a stimulus to the fibroblasts. Indications for Artecoll are all facial folds, lip- and philtrum augmentation, chin- and malar augmentation, dark-shadowed eyelids, enophthalmos, bony defects in face and hands, nipple reconstruction and augmentation, and urinary incontinence. Questionnaires were sent to all patients who had received Artecoll in 1993 and 1994. Of a total of 950 questionnaires sent, 515 were returned by September 1995. Satisfaction was rated ``very good' in 29%, ``good' in 38%, ``satisfactory' in 23%, and ``no difference' in 8% of the patients. The question, ``Would you repeat the treatment again?' was answered by 91% of the patients with ``yes.' The overall complication rate was 3%. Strictly subdermal implantation will prevent longer lasting redness or visibility of the Artecoll.     

Optic disc histomorphometry in normal eyes and eyes with secondary angle-closure glaucoma

The intrapapillary region of the optic disc shows ophthalmoscopical changes in glaucoma. In search of a histological correlate, this region was examined histomorphometrically in serial sections of 21 human eyes with secondary angle-closure glaucoma and 28 control eyes with malignant choroidal melanoma. The lamina cribosa was significantly (P less than 0.05) thinner, the optic cup deeper and wider, the peripapillary scleral ring finer, and the corpora amylacea count was lower in glaucoma eyes than in control eyes with normal optic nerves. There was no significant difference in optic disc diameter. The decrease in lamina cribrosa thickness may be one of several factors leading to glaucomatous optic nerve fiber loss. Due to a decrease in the relative height the inner limiting membrane should not be taken as the reference level for optic-cup-depth measurement. A high corpora amylacea count may point to a normal optic nerve fiber population.     

Initial motor impairment influences activation pattern of motor recovery

OBJECTIVES: We investigated the functional magnetic resonance imaging (fMRI) activation pattern of a motor task in patients with acute subcortical lesions to examine the relationship between activation pattern and recovery of motor impairment. METHODS: Five patients (one with subcortical infarction and four with thalamic hemorrhage) were examined using fMRI 1 month after the insult. Impairment was assessed by the Medical Research Council motor strength classification (MRC). One patient with severe motor deficits was also studied at 4 months when her motor deficits improved up to MRC grade 4. RESULTS: Three patients with relatively mild deficits (MRC grade 3 or 4) at their onsets, improved fully up to grade 5 within 1 month. FMRI performed at 1 month showed activation in the contralateral primary motor cortex and supplementary motor area (SMA), but no significant activation was seen on the ipsilateral unaffected side. Two patients with severe motor impairment (MRC grade 1) improved up to 3 and 4 of MRC at 1 month or later. They showed activation of the ipsilateral premotor area as well as contralateral primary motor cortex and SMA. One of them, whose severe motor deficit improved at 4 month, also showed activation of the ipsilateral postcentral gyrus and the activated area expanded longitudinally corresponding with her functional recovery. DISCUSSION: Our study demonstrates that the fMRI pattern varies according to functional recovery, suggesting the importance of the ipsilateral premotor area and postcentral gyrus especially for those patients with severe motor impairment initially.     

Safety of latest-generation self-expanding stents in patients with NASCET-ineligible severe symptomatic extracranial internal carotid artery stenosis

BACKGROUND: Patients with symptomatic extracranial internal carotid artery stenosis (> or =70%) benefit from carotid endarterectomy when compared with medical management. However, independent risk factors can significantly increase the combined stroke and death risk after carotid endarterectomy. Carotid angioplasty and stenting (CAS) is a therapeutic option in patients who are otherwise at high risk or ineligible for carotid endarterectomy. Previous-generation self-expanding stents were hampered by length foreshortening, which limited their application in multifactorial occlusive extracranial internal carotid artery stenosis. METHODS: This is a single-center, prospective, open-label, safety study of CAS with the latest-generation self-expanding stents in patients with extracranial internal carotid artery symptomatic stenosis (> or =70%). All patients included were adjudicated to be ineligible for carotid endarterectomy by a vascular surgeon and/or a neurologist according to the exclusion criteria. Primary adverse events included death and all strokes (ipsilateral and contralateral). Secondary adverse events included transient ischemic attack, myocardial infarction, stent thrombosis, need for reintervention, and presence of hematomas. All adverse events were recorded at 24 hours, 30 days, and 6 months after CAS. RESULTS: Between June 1, 2001, and January 30, 2003, 23 consecutive patients (14 women and 9 men; mean age, 65 years; age range, 48-85 years) underwent 24 extracranial CAS procedures with the latest-generation self-expanding stents. All patients had one or multiple criteria for ineligibility according to the North American Symptomatic Carotid Endarterectomy Trial. Extracranial CAS was successful in all patients, with average residual stenosis of less than 20%. One patient (4%) experienced a stroke by the 30-day periprocedure examination. The total number of primary adverse events at 6 months after CAS was 2 strokes (9%), 1 of which was contralateral to the stent placement; there were no deaths. Twenty-two patients were asymptomatic at 6 months, with a modified Rankin scale score of 1 or less. Of the 2 patients who had a stroke, 1 had a follow-up modified Rankin scale score of 3. CONCLUSION: Extracranial CAS with the latest-generation self-expanding stents is a valid alternative treatment in high-risk or North American Symptomatic Carotid Endarterectomy Trial-ineligible patients.     

Anodal transcranial direct current stimulation of the prefrontal cortex enhances complex verbal associative thought

The remote associates test (RAT) is a complex verbal task with associations to both creative thought and general intelligence. RAT problems require not only lateral associations and the internal production of many words but a convergent focus on a single answer. Complex problem-solving of this sort may thus require both substantial verbal processing and strong executive function capacities. Previous studies have provided evidence that verbal task performance can be enhanced by noninvasive transcranial direct current stimulation (tDCS). tDCS modulates excitability of neural tissue depending on the polarity of the current. The after-effects of this modulation may have effects on task performance if the task examined draws on the modulated region. Studies of verbal cognition have focused largely on the left dorsolateral prefrontal cortex (F3 of the 10-20 EEG system) as a region of interest. We planned to assess whether modulating excitability at F3 could affect complex verbal abilities. In Experiment 1 (anodal, cathodal, or sham stimulation over F3 with the reference electrode over the contralateral supraorbital region), we found a significant overall effect of stimulation condition on RAT performance. Post hoc tests showed an increase in performance after anodal stimulation (1 mA) compared to sham (p = .025) and to cathodal stimulation (p = .038). In Experiment 2 (either anodal stimulation at F3 or separately at its homologue F4), we replicated the anodal effect of the first study, but also showed that anodal stimulation of F4 had no effect on RAT performance. These data provide evidence that anodal stimulation of the left dorsolateral prefrontal cortex can improve performance on a complex verbal problem-solving task believed to require significant executive function capacity.