BACKGROUND: To evaluate the exact topography of lateral hypopharyngeal pouches using electron beam tomography. METHODS: Seventeen patients, nine female, eight male, aged 28-72 years, who showed lateral hypopharyngeal pouches in the videofluorographic swallowing examination were studied using electron beam tomography. Upon swallowing a 20-ml bolus of water, the region of the thyrohyoid membrane was scanned 20 times per level. Scan parameters: single slice cine mode (exposure time 100 ms, slice thickness 3 mm, 620 mA, 130 KV). RESULTS: The lateral hypopharyngeal pouches appeared air-filled in the posterior aspect of the thyrohyoid membrane closely attached to the upper horn of the thyroid cartilage, just below the hyoid bone. CONCLUSIONS: With electron beam tomography it was possible to define the topographic location of the pouches more accurately, compared with the prior assumption of position.

Adult↗

PubMedDate not supplied

Percutaneous cholangioscopy in obstructed biliary metal stents.

PURPOSE: To reevaluate the reasons for the occlusion of self-expanding biliary metal stents, on the basis of cholangioscopic findings. METHODS: Percutaneous transhepatic cholangioscopy (PTCS) was performed in 15 patients with obstructed biliary Wallstents. The reason for stent insertion was a malignant obstruction in 14 patients; 1 had a benign biliary stricture. Conventional noncovered stents had been inserted in 12 patients; in 3 cases a polyurethanecovered prototype Wallstent had been used. Stent occlusions occurred after 1-55 months. PTCS was performed with a 2.3-mm endoscope through an 11 Fr sheath. Biopsies were taken via the working channel of the endoscope. RESULTS: In all patients with noncovered stents the inner surface of the stent was highly irregular with seaweed-like protrusions (biopsy-proven granulation tissue). Stent incorporation varied from absent (n = 1) to subtotal (n = 8), but was always incomplete, no matter how long the stent had been in place. Tumor ingrowth was histologically proven in 2 patients. One patient had a large occluding concrement at the proximal end of the stent. In patients with covered stents, the inner surface appeared more regular; however, viable granulation tissue was found inside two stents and tumor ingrowth in one of them. CONCLUSION: PTCS showed that incorporation of the stent is virtually always incomplete. The factors contributing most to stent occlusion are the buildup of granulation tissue, bile sludge, and tumor overgrowth. Stone formation and tumor ingrowth can also be important, although less common causes of occlusion. A polyurethane stent covering could not prevent tumor ingrowth in one patient and the buildup of viable granulation tissue inside the stent in two further patients; mean stent patency in the three patients with such a stent was 3 months.

Aged↗

PubMedDate not supplied

Concurrent validity of negative symptom assessments in treatment refractory schizophrenia: relationship between interview-based ratings and inpatient ward observations.

The concurrent validity of interview-based ratings of negative symptoms in 35 inpatients with chronic, treatment refractory schizophrenia was evaluated. Correlations were examined between interview-based ratings of negative symptoms, measured by the Brief Psychiatric Rating Scale and the Positive and Negative Syndrome Scale, and the naturalistic behavior of inpatients as assessed by the Time Sample Behavior Checklist. Higher levels of interview-based negative symptoms were related to reduced interpersonal activity on the inpatient ward, but not to entertainment, instrumental or self-maintenance activities. These findings offer partial support for the concurrent validity of office-based ratings of negative symptoms, and highlight the importance of longitudinal observations of patients for accurate identification of negative symptoms.

Adolescent↗

PubMedDate not supplied

Replication cycle dependent association of SeqA to the outer membrane fraction of E. coli.

The hemimethylated oriC binding activity of the E. coli heavy density membrane fraction (outer membrane) was investigated by DNase I footprinting experiments using membranes obtained from different replication stages of PC-2 (dnaCts) cells. The maximal binding activity was found at the beginning of replication cycle and then decreased gradually. The same pattern of variation was observed with SeqA protein detected in the membranes by immunoblotting. Both binding activity and the presence of SeqA were conserved in the outer membrane even after floating centrifugation of the heavy density membrane fraction in a sucrose gradient, indicating that SeqA in fact can associate with the membrane and that this association varies according to replication cycle. Site specific binding to hemimethylated oriC, of the heavy density membrane obtained from seqA mutant, could be restored by addition of a low amount of His-tagged SeqA protein.

Bacterial Outer Membrane Proteins↗

PubMedDate not supplied

Interactions of local movement detectors enhance the detection of rotation. Optokinetic experiments with the rock crab, Pachygrapsus marmoratus.

Walking crabs move their eyes to compensate for retinal image motion only during rotation and not during translation, even when both components are superimposed. We tested in the rock crab, Pachygrapsus marmoratus, whether this ability to decompose optic flow may arise from topographical interactions of local movement detectors. We recorded the optokinetic eye movements of the rock crab in a sinusoidally oscillating drum which carried two 10-deg wide black vertical stripes. Their azimuthal separation varied from 20 to 180 deg, and each two-stripe configuration was presented at different azimuthal positions around the crab. In general, the responses are the stronger the more widely the stripes are separated. Furthermore, the response amplitude depends also strongly on the azimuthal positions of the stripes. We propose a model with excitatory interactions between pairs of movement detectors that quantitatively accounts for the enhanced optokinetic responses to widely separated textured patches in the visual field that move in phase. The interactions take place both within one eye and, predominantly, between both eyes. We conclude that these interactions aid in the detection of rotation.

Animals↗

PubMedDate not supplied

Systemic healthcare reform: is it time? Six proposals for universal coverage.

Explore the source record for details and available documents.

Costs and Cost Analysis↗