Dobutamine stress cine-MRI of cardiac function in the hearts of adult cardiomyocyte-specific VEGF knockout mice.

A mouse model of non-necrotic vascular deficiency in the adult heart was studied using cine-magnetic resonance imaging (MRI) and other techniques. The mice lacked cardiomyocyte-derived vascular endothelial growth factor (VEGF) following a targeted knockout in the ventricular cardiomyocytes. Quantitative endothelial labeling showed that the capillary density was significantly reduced in the hearts of knockout mice. Gene expression patterns suggested that they were hypoxic. Semiautomated MR image analysis was employed to obtain both global and regional measurements of left ventricular function at 10 or more time points through the cardiac cycle. MRI measurements showed a marked reduction in ejection fraction both at rest and under low- and high-dose dobutamine stress. Regional wall thickness, thickening, and displacement were all attenuated in the knockout mice. A prolonged high-dose dobutamine challenge was monitored by MRI. A maximal response was sustained for 90 minutes, suggesting that it did not depend on endogenous glycogen stores.

Auditory feature conjunction in patients with schizophrenia.

The neural mechanisms supporting performance during single feature and feature conjunction tasks were investigated in patients with schizophrenia and age-matched controls using event-related brain potentials. In different blocks of trials, participants responded to auditory targets defined by one of two pitches, one of two locations, or both pitch and location. All participants were faster and more accurate in detecting targets defined by a single feature than for targets defined by a conjunction of features. Compared with the single feature conditions, conjunction targets were associated with enhanced negativity between 200 and 250ms (N2) post-stimulus and showed a delayed P3b latency. Compared with controls, patients with schizophrenia showed reduced N1 and N2 amplitude elicited by single and conjunctive targets. The results are consistent with defective perceptual mechanisms in schizophrenia. The fact that both performance and P3b amplitude were similar in patients and controls suggests that controlled processes compensate for processes normally carried out by early perceptual mechanisms.

Cryogen spray cooling in combination with nonablative laser treatment of facial rhytides.

BACKGROUND: Cryogen spray cooling can be used to provide epidermal protection while still achieving spatially selective photocoagulation in the upper dermis. The objective of this study is to determine the efficacy and safety of cryogen spray cooling in combination with a nonablative Nd:YAG (lambda = 1320 nm) laser treatment of facial rhytides in human volunteers. OBSERVATIONS: Thirty-five adults with bilateral periorbital rhytides were treated with cryogen spray cooling in combination with 3 nonablative laser treatments performed sequentially at intervals of 2 weeks. Small but statistically significant improvements were noted in the mild, moderate, and severe rhytid groups 12 weeks after the final laser treatment. A final assessment performed 24 weeks after the last treatment showed statistically significant improvement only in the severe rhytid group. The procedure was found to be safe; 4 sites (5.6%) developed transient hyperpigmentation. Two sites (2.8%) subsequently developed barely perceptible pinpoint pitted scars. CONCLUSIONS: Cryogen spray cooling is a safe and effective method for protecting the epidermis during nonablative laser treatment of facial rhytides thereby avoiding much of the morbidity associated with other resurfacing procedures. Minor improvements in rhytides can be achieved with the current technology. Optimization of treatment parameters may further improve these results.

Binding visual features during high-rate serial presentation.

The neural mechanism supporting performance during single and feature conjunction detection was investigated using event-related brain potentials. In different blocks of trials, participants responded to visual targets defined by one of two colors, one of two orientations, or both color and orientation. Participants were faster and more accurate in detecting targets defined by a single feature than for targets defined by a conjunction of features. Compared with the single feature conditions, conjunction targets were associated with enhanced negativity between 230 and 270 ms post-stimulus and showed a delayed P3 latency. The relative timing of feature specific attention effects isolated in difference potential shows that feature conjunction occurs concurrently with the analysis of single features.

Guanidinobenzoatase and UPA in high-grade human astrocytomas and after xenografting cell suspensions into the rat cerebral cortex: proteases for metastasis and disease progression.

BACKGROUND: Invasion and metastasis is aided by the secretion of guanidinobenzoatase, that cleaves the link peptide to fibronectin, and urokinase plasminogen activator (uPA), which initiates a molecular cascade to activate plasmin and collagenases. This process permits malignant cell migration through the extracellular matrix. MATERIALS: Original human astrocytomas were examined for guanidinobenzoatase and uPA. Suspensions of high-grade human astrocytomas were xenografted into pockets in host cerebral cortex for 1-7 days. RESULTS: A class of guanidinobenzoatase positive cells was observed in the original human astrocytomas and in tumor masses formed in the implantation pocket and around blood vessels. Secondary foci containing guanidinobenzoatase positive cells formed around blood vessels and individual positive astrocytoma cells migrated on the glia limitans along parallel and intersecting nerve fiber fascicles and the corpus callosum. uPA and GFAP were colocalized with guanidinobenzoatase. CONCLUSION: The high-grade astrocytomas reestablish themselves and maintain their characteristics as a tissue although grafted as individual cells.

Scar resurfacing with high-energy, short-pulsed and flashscanning carbon dioxide lasers.

BACKGROUND: Scars have a significant effect on a person's physical and social being. Many treatment modalities for scar improvement such as surgical scar revision, electrosurgical planing, chemical peeling, filler substance implantation, and dermabrasion have been developed. Recently, the resurfacing carbon dioxide (CO2) laser systems have proven to be a useful and safe treatment in the treatment of facial rhytides and acne scarring. OBJECTIVE: The purpose of this study was to evaluate the resurfacing CO2 lasers in the treatment of various surgical, traumatic, acne, and varicella scars. METHODS: Thirty subjects, aging between 14 and 84 years, with surgical, traumatic, acne, or varicella scars were evaluated. Two types of resurfacing laser systems were utilized in this study, a high-energy, short-pulsed CO2 laser and a continuous wave CO2 laser with an optico-mechanical computer flash-scanner. Post-surgical scars were treated with laser resurfacing between 4 and 6 weeks after scar formation. Traumatic, acne, and varicella scars were treated after scar maturation (range, 1-10 years). Scar improvement was evaluated by photographic analysis of before and after images by four independent health care workers using a quartile scale of improvement (< 25%, 25-49%, 50-74%, > 75%) as well as optical profilometry using silicone surface impressions in 12 scars. RESULTS: Twenty of 24 surgical scars had greater than 75% improvement, and 24 of 24 had greater than 50% improvement by photographic analysis. All six traumatic, acne and varicella scars had greater than 50% improvement. Optical profilometry and surface topography maps reveal a significant flattening of related and depressed scars. CONCLUSION: The high-energy, short-pulsed CO2 laser and the continuous wave CO2 laser with flash-scanning attachment are safe and effective as a treatment modality for scar revision. In general, elevated scars improve more dramatically than depressed scars.

The short- and long-term side effects of carbon dioxide laser resurfacing.

BACKGROUND: Carbon dioxide (CO2) laser resurfacing has become a very popular method of rhytide and scar removal in the recent past. Preliminary studies have been published describing the method, histology, and clinical results of CO2 laser resurfacing. However, none of these studies has dealt with long-term follow-up results. OBJECTIVE: To review all side effects resulting from CO2 laser resurfacing with regard to both short- and long-term effects. METHOD: Retrospective analysis of 104 patients who have undergone CO2 laser resurfacing for either facial rhytides and/or scarring with follow-up periods of 4-23 months (average, 8.2 months). RESULTS: The incidence of side effects are generally very low for CO2 laser resurfacing, including scarring, postinflammatory hyperpigmentation, and infection. However, there is a significant and previously unreported risk of hypopigmentation in an area of the population who often seek improvement in the appearance. CONCLUSIONS: CO2 laser resurfacing of facial rhytides and acne scars can be a very safe procedure by an experienced laser operator. However, careful patient selection, thorough patient instruction, and proper aesthetic analysis of treatment sites must be followed to insure the most favorable outcomes with CO2 laser resurfacing.

Direction of motion influences perceptual identification of ambiguous figures.

It is known that the perceived identity of an ambiguous figure can influence how that figure is perceived to move. In 6 experiments, the converse effect-the role of motion in the perceptual identification of ambiguous figures (e.g., N. Tinbergen's, 1951, goose-hawk)-was examined. In general, observers were biased to identify a moving ambiguous figure as that object whose face pointed in the direction of motion. Experiments 1-4 replicated this basic effect over induced, apparent, and smooth motion displays. Results from Experiment 5 show that longer interstimulus intervals led to smaller biases, with all bias disappearing around 1,500 ms. In Experiment 6, direction of motion influenced perceptual identification even in the presence of conflicting shape information.

Tattoo formation from absorbable synthetic suture and successful removal with Q-switched ruby laser.

BACKGROUND: Traumatic tattoos result from accidental or unintentional deposition of exogenous pigment within injured skin. Pigments may consist of heavy metals, vegetable matter, or commercial dyes. OBJECTIVE: The clinical and histologic description of a traumatic tattoo resulting from a surgical procedure using undyed, braided, synthetic, absorbable suture material and its removal with the Q-switched ruby laser (694 nm, 28 nsec). METHODS: The pigmented linear lesion was biopsied and processed using standard histological methods. Subsequently, the area was treated on two occasions with the Q-switched ruby laser. RESULTS: The pigmented lesion was completely removed with the Q-switched laser treatments. CONCLUSION: We report on the occurrence of a traumatic tattoo resulting from synthetic suture material and complete removal with the Q-switched ruby laser.

Treatment of resistant oral aphthous ulcers in children with acquired immunodeficiency syndrome.

Four children with acquired immunodeficiency syndrome and aphthous oral ulcers with severe odynophagia were treated with a short oral course of prednisone. The lesions resolved completely with no adverse effects. We recommend considering a short course of prednisone for relief of symptoms in these patients.

Localized linear bullous eruption of systemic lupus erythematosus in a child.

A 9-year-old girl newly diagnosed with systemic lupus erythematosus (SLE) developed a localized linear papulovesicular eruption over the right dorsal hand and ulnar forearm. The skin findings were clinically suggestive of herpes zoster, lichen striatus, or lichen planus-lupus erythematosus overlap. However, histologic, immunofluorescent, immunoelectron microscopic, and immunoblot studies revealed findings compatible with bullous SLE. Our patient is noteworthy because she is the first one reported with bullous SLE presenting in a localized linear pattern. She is also the second-youngest reported patient with bullous SLE.

Neurologic disorders and dermatologic manifestations in HIV-infected children.

Cutaneous manifestations of HIV infections in childhood are common but are not the dermatologic lesions associated with HIV infection in adults. For example, Kaposi's sarcoma, a common finding in adults with AIDS, is rare in children. Other cutaneous manifestations, including bacterial and fungal lesions and viral exanthems, are common in children with AIDS and can be atypical and severe. Because 90% of the pediatric AIDS population acquires the virus via maternal transmission to the fetus, a dysmorphic syndrome associated with intrauterine infection has been described. Physicians caring for and evaluating pediatric patients at risk for AIDS should be aware of these dermatologic manifestations, so that early detection and treatment can be instituted to reduce the morbidity of the complication of HIV infection.

Pneumocystis carinii pneumonia in young children with AIDS.

We present our experience with 54 episodes of Pneumocystis carinii pneumonia in 50 young children with AIDS, all but one representing congenitally acquired infection. Findings at history and physical examination are not helpful in suggesting the diagnosis. The diagnosis is suggested by marked hypoxemia, diffuse disease on chest radiograph, and elevated serum LDH level. Because important aspects of the history may be withheld, a high index of suspicion may be necessary for the correct diagnosis. The mortality rate for ventilated patients was 50%.

Prognostic factors and life expectancy in children with acquired immunodeficiency syndrome and Pneumocystis carinii pneumonia.

Eighteen children with the acquired immunodeficiency syndrome (AIDS) were diagnosed as having Pneumocystis carinii pneumonia (PCP) by either open lung biopsy or bronchoalveolar lavage. Seven patients (39%) died during the acute illness. Alveolar-arterial oxygen gradients at the time of presentation and lactate dehydrogenase levels did not distinguish survivors from nonsurvivors. Total lymphocyte and T4 cell counts were low in children who died during the initial PCP infection but had considerable overlap with survivors. Response to phytohemagglutinin was measured in 5 of the 7 patients who died initially. In these patients, the mean phytohemagglutinin response was 1977 cpm. Of the 11 early survivors, 10 died within 27 months after PCP. Mean phytohemagglutinin response was 46,079 cpm in patients who died within 1 year, and 44,768 cpm in those who died later. Only 1 child is still alive 5 years after PCP illness. Children with AIDS and PCP infection have high initial mortality and poor long-term prognosis. Response to phytohemagglutinin is helpful in predicting who will survive initial PCP infection.

Thrombocytopenia and human immunodeficiency virus in children.

Thrombocytopenia occurs in 13% of children with symptomatic human immunodeficiency virus (HIV) infection. The clinical and laboratory course of 19 children infected with HIV with thrombocytopenia is described. Bone marrow aspirates showed normal to increased numbers of megakaryocytes. Levels of antiplatelet antibodies were increased in 80% of the children and circulating immune complexes were found in 74%. Clinically significant hemorrhage leading to anemia occurred in five patients, and CNS bleeding led to a fatal outcome in an additional three children. Spontaneous remission of thrombocytopenia occurred in three of the 19 subjects. High-dose IV gamma-globulin was effective in increasing the platelet counts of six of 15 patients (40%) but resulted in a sustained remission in only one subject. Oral prednisone was effective in increasing the platelet count of two thirds of those whose platelet counts could not be controlled by IV gamma-globulin. Bleeding manifestations were eliminated in all patients whose platelet counts increased significantly. Of the 11 children whose counts increased either spontaneously or as a result of therapy, eight remain alive (72%). In contrast, all of the eight patients whose platelet counts did not improve have died. Thrombocytopenia in children with HIV disease is engendered by immune mechanisms and is a major cause of morbidity and mortality. High-dose IV gamma-globulin and/or corticosteroids are temporarily effective in increasing the platelet count and reducing bleeding in about half of thrombocytopenic patients and are recommended for use. The ability to respond to therapy correlates with improved survival.

Corticosteroid treatment for pulmonary lymphoid hyperplasia in children with the acquired immune deficiency syndrome.

Five children with positive serology for human immunodeficiency virus (HIV) infection by enzyme-linked immunosorbent assay and Western blot were followed for chronic pulmonary disease. Lung biopsies were performed in all patients, and confirmed the diagnosis of pulmonary lymphoid hyperplasia. All children demonstrated progressive hypoxia and increasing alveolar capillary oxygen gradients over at least 1 year of follow-up. All children were on periodic intravenous gamma globulin treatment for a B-cell defect prior to the initiation of corticosteroid therapy. Prednisone was initially given at a dose of 2 mg/kg daily and was subsequently tapered to an alternate day regimen. All children showed improvement in oxygenation. No deterioration in immune function was noted, and there was no increase in bacterial infection. This study indicates that corticosteroids can successfully reverse the severe hypoxia that may result from pulmonary lymphoid hyperplasia in pediatric AIDS patients.