Effects of platelet activating factor on vascular permeability of the middle ear mucosa

Platelet activating factor (PAF), a potent inflammatory mediator, seems to play a significant role in the pathogenesis of otitis media with effusion (OME), along with other inflammatory mediators such as leukotrienes and prostaglandins. The purpose of this study was to investigate the effect of PAF on the vascular permeability of middle ear mucosa, in an experimental OME model using chinchillas. We injected PAF in doses of 1, 4, 8, and 16 micrograms and normal saline as a control into the bullae of chinchillas. Vascular permeability was measured by the Evans blue vital dye technique. All the PAF-injected animals showed a significant increase in middle ear vascular permeability compared to the control group. This study demonstrated that PAF in the middle ear cavity contributes significantly to the development of OME by increasing the vascular permeability of the middle ear mucosa.

Domoic acid: neurobehavioral and neurohistological effects of low-dose exposure in adult rats

Adult rats treated IP with domoic acid at 0, 0.22, 0.65, or 1.32 mg/kg were tested for passive avoidance (PA), auditory startle (AS), or conditioned avoidance (CAR) behaviors. Clinical signs were observed only at the 1.32 mg/kg dose level. Within 24 h of dosing, rats surviving a dose of 1.32 mg/kg exhibited transient decreased body weight and exaggerated AS responding. Startle latency and habituation, PA, and CAR were not affected. Examination of brains from six rats per group revealed a subset (2/6) of animals receiving 1.32 mg/kg domoic acid with degenerating neurons in the hippocampal CA1/CA3 subregions and gliosis. The decreased body weight and increased startle suggest a hyperreactivity syndrome possibly related to neuronal degeneration in the hippocampus. In a separate experiment, domoic acid at an IP dose of 0.93 mg/kg was found to produce hypomotility in addition to a decrease in body weight. Both effects were reduced by pretreatment with scopolamine (2 mg/kg), but not with caffeine (30 mg/kg), indicating a possible cholinergic involvement in domoate's toxicity.

Factors related to quality of life and functional status in 50 patients with head and neck cancer

Quality of life (QOL) and functional status (FS) have become important outcome measures in cancer therapy. Valid and reliable instruments recently have been developed for examining QOL and FS in patients with head and neck (HN) cancer. The present study evaluated the relationships of QOL and FS to physical and psychological variables assumed to affect QOL and FS. Fifty patients were evaluated up to 6 years after HN cancer surgery using one general QOL instrument and three HN-specific instruments. Analysis of variance showed physical variables such as tumor site to be related to HN-specific scores, while psychosocial variables such as marital status were related to general QOL scores (P < or = .05). Several relationships were seen between physical or psychosocial variables and FS or QOL measures; however the relationships were not as strong or direct as expected.

Quality of life and functional status measures in patients with head and neck cancer

OBJECTIVE

To assess the relationship among three validated head and neck-specific measures of functional status and a general measure of quality of life in patients with head and neck cancer.

DESIGNS

Cross-sectional study using medical chart review, patient interview, and test administration.

SETTING

Academic tertiary referral center.

PARTICIPANTS

Fifty adults patients 3 months to 6 years after major surgery for head and neck cancer.

MAIN OUTCOME MEASURE

Scores from a general measure of quality of life (the Functional Assessment of Cancer Therapy), a subscale specific to head and neck cancer, the University of Washington Quality of Life Questionnaire, and the Performance Status Scale for Head and Neck Cancer Patients.

RESULTS

The disease-specific measures of functional status correlate well with one another. However, there were low correlations between the Functional Assessment of Cancer Therapy and the disease-specific measures, indicating that general and disease-specific instruments contribute unique information about quality of life.

CONCLUSION

A general measure of quality of life augments information obtained by disease-specific instruments by interpreting functional status in the broader scope of the patient's life.

Acoustic neuroma volume: MRI-based calculations and clinical implications

This study developed a technique for magnetic resonance imaging (MRI)-based volume calculation and defined the specific volume-diameter relationship in acoustic neuromas (AN). Computer-assisted measurement calculated the area of tumor in each MRI slice. Volume was determined by multiplying area by slice interval. The technique was validated by imaging known volumes of gadolinium. The precision was greater than 95%. Our volume calculations revealed a specific volume-diameter relationship in ANs. The following conclusions can be drawn: 1. our technique can accurately determine AN tumor volume; 2. the AN volume-diameter relationship is a specific function and cannot be predicted by assumptions of tumor shape; 3. the volume-diameter relationship should be combined with clinical data to determine the "break point" at which small increments of diameter produce significant clinical sequelae.

Immature trichoepithelioma: report of six cases

We report 6 cases of an immature variant of trichoepithelioma which histologically appears to show differentiation toward the primitive hair germ. The lesions presented in mature adults (mean age 44 years). Four occurred in men and 2 in women. Four lesions occurred on extremities, an unusual location for trichoepitheliomas. Histologically, the lesions were characterized by well-circumscribed, but unencapsulated, dermal collections of small tumor lobules composed of basaloid cells with invaginations resembling primitive dermal hair papillae. There was no adenoidal growth pattern or horn cyst formation. The separation of the immature lesions from those of classical trichoepithelioma and basal cell carcinoma can be made if multiple morphological features are considered; no one particular finding is diagnostic. The major differential features between the immature trichoepithelioma and basal cell carcinoma are circumscription, tumor lobule uniformity, occasional immature hair germs, and lack of retraction artifact of the tumor lobules from the stroma. The differential features between the immature and classical trichoepithelioma are less conspicuous. The immature form typically exhibits no horn cysts, displays fewer primitive hair structures, and lacks the adenoidal growth patterns of the tumor lobules which are usually present in the classical trichoepitheliomas.

Determining intraocular lens power within the eye

A method is described for determining the power of an intraocular lens (IOL) within the eye by measuring the horizontal dimension of the corneal reflected image (Purkinje-Sanson I) and the anterior IOL reflected image (Purkinje-Sanson III) as seen through a standard slitlamp with a target positioned 68 mm anterior to the focal plane of the biomicroscope. The horizontal K-reading (at 180 degrees) and the anterior chamber depth are the two other parameters necessary to calculate the exact power of the IOL. Seven tables that use these four measurements have been provided, eliminating the need for complex calculations. To determine the accuracy of this technique, ten implanted IOLs ranging from 9 diopters (D) to 27 D were chosen and their powers calculated; these calculated values were then compared to the actual IOL powers. The largest error was 0.5 D and the average error was 0.17 D.

The composition of the ceramides from human stratum corneum and from comedones

Human epidermal surface lipids were collected by an ethanol wash and the ceramides were quantified by thin-layer chromatography-photodensitometry. Six ceramide fractions were isolated and the structural components of each were analyzed in detail. The most unusual of the epidermal ceramides contained a sphingosine base with amide-linked 30- and 32-carbon omega-hydroxyacids and an ester-linked nonhydroxyacid, 41% of which was linoleic acid. The proportion of linoleic acid in the analogous ceramide from comedones was 6%. This supports the hypothesis that a localized insufficiency of linoleic acid in the follicular epithelium is an etiologic factor in comedogenesis.

Human stratum corneum polar lipids and desquamation

The ceramides and steryl-sulfate components from desquamated and cohesive human stratum corneum were examined using a combination of chemical and chromatographic means. Six structurally distinct series of ceramides were identified, and the relative amounts of these species, as measured by quantitative thin-layer chromatography, did not differ in cohesive and desquamated stratum corneum. In contrast, the level of cholesteryl sulfate was significantly reduced in the desquamated material. The results are in accord with the hypothesis that cholesteryl sulfate serves in cell-to-cell cohesion within the stratum corneum, and its hydrolysis may be necessary to permit shedding of cells from the surface.

In vivo assessment of left ventricular wall and chamber dynamics during transient myocardial ischemia using prospectively ECG-gated computerized transmission tomography

Seven dogs were evaluated with prospective ECG-gated computerized transmission tomography (CTT) to analyze left ventricular (LV) wall thickness and cross-sectional chamber area after acute occlusion of the left anterior descending coronary artery (LAD). ECG-gated CTT scanning during i.v. administration of contrast material was performed over the mid-left ventricle at rest, after acute occlusion of the LAD and 30 minutes after release. The extent of systolic wall thickening (EWTh) of the anterior (potentially ischemic) segment was 39.8 +/- 8.8% (SEM) in the control state and -26.0 +/- 4.7% during LAD occlusion (p less than 0.01). The nonischemic septum demonstrated a compensatory increase in EWTh, from 28.6 +/- 3.5% to 46.4 +/- 6.1% during LAD occlusion (p less than 0.05). The end-diastolic LV luminal area (LVA) increased from 17.4 +/- 0.8 cm2 in the control state to 21.0 +/- 1.1 cm2 during LAD occlusion (p less than 0.01). End-systolic LVA also increased, from 11.0 +/- 0.9 to 15.2 +/- 1.1 cm2 (p less than 0.01). In addition, the percent change in LVA from end-diastole to end-systole declined from 37.4 +/- 3.8% during control to 28.0 +/- 2.6% during LAD occlusion (p less than 0.02). In conclusion, gated CTT demonstrates that the alterations in acute ischemia are characterized by changes in regional wall thickening dynamics, consisting of wall thinning during systole in the jeopardized segment and compensatory increase in the extent of systolic thickening in the normal segment, and changes in global LV function, consisting of an increase in the LVA and a decrease in the percent change of LVA during systole. Gated CTT may be useful for monitoring regional and global effects of ischemia when subjects can be studied in the supine position and with respiration suspended for 45 seconds.

Computer technique for monitoring time dependent changes from sequential CT images

The sequential computed tomography (CT) images used in this manuscript are electrocardiogram-gated images of the same cross section of the heart (10 in this study) depicting one cardiac cycle from end-diastole to the next end-diastole. Each of these 10 reconstructions corresponds to 10% intervals extending from one R wave to the next R wave. When each image of the series of 10 images is assigned a consecutive table position, using the program for sagittal reconstructions a chronogram along any line through the X-Y plane of the left ventricular (LV) wall can be produced. The chronograms display changes in wall thickness and wall motion in relation to time throughout the cardiac cycle at a preselected site in the LV and can be used to demonstrate the LV myocardial response to perturbations. This technique adds the dimension of time to spatial information in the CT images and can be used to monitor cardiac physiology in a quantitative fashion.