Argyrophilic nuclear organizer regions in nasopharyngeal carcinoma and paraneoplastic epithelia

BACKGROUND: Nucleolar organizer regions (NORs), which are loops of DNA containing ribosomal RNA genes, have been shown to correlate with cell proliferation and malignant transformation. The diagnostic value of silver staining NORs (AgNORs) in preneoplastic epithelia and nasopharyngeal carcinoma (NPC) by the quantitative assessment of AgNORs proteins is evaluated. METHODS: Silver-staining of NORs was applied to 70 paraffin sections of NPC biopsy specimens, including 29 samples of the adjacent normal glandular epithelia (GE), 19 hyperplastic/dysplastic columnar epithelia (CE) in the adjacent mucosa, 10 hyperplastic/dysplastic squamous epithelia (SE) in the adjacent mucosa, 54 differentiated nonkeratinizing carcinoma (DC), and 16 undifferentiated carcinoma (UC). The morphometric features of AgNORs in preneoplastic epithelia and cancer cells were analyzed by image cytometric analysis and then compared. RESULTS: The AgNOR count, mean AgNOR area, and AgNOR area-count ratio increased significantly from GE to CE to DC or UC. The mean nuclear area, AgNOR area, and AgNOR area-count ratio increased significantly from GE to SE to UC, whereas overlapping AgNOR values were observed between SE and DC. UC had significantly higher values than DC in mean nuclear area, AgNOR area, and AgNOR area-count ratio. CONCLUSIONS: The morphometric analysis of AgNORs reflected cell proliferative activity and histologic differentiation of tumor rather than malignant transformation in different nasopharyngeal epithelia and NPC. AgNOR area and AgNOR area-count ratio are the most valuable features for differential diagnosis of normal, preneoplastic, and cancer cells.     

Cryopreservation—induced decrease in heat—shock protein 90 in human spermatozoa and its mechanism

Aim: To study the protein changes of spermatozoa associated with sperm motility during sperm cryopreservation and its mechanism. Methods: In 18 healthy men, the seminal sperm motility and HSP90 levels were studied before and after cryopreservation using SDS-PAGE, Western blotting and computerized image analysis. Results: The sperm motility declined significantly after cryopreservation (P<0.01). The average grey level and the integrated grey level of sperm HSP90 before cooling were 34.1±3.2 and 243.0±21.6, respectively, while those after thawing were 23.2±2.5 and 105.7±28.5, respectively. Both parameters were decreased significantly (P<0.01). No HSP90 was found in the seminal plasma before and after cryopreservation. Conclusion: HSP90 in human spermatozoa was decreased substantially after cryopreservation. This may result from protein degradation, rather than leakage into the seminal plasma.     

A wavelet-based approximation of surface coil sensitivity profiles for correction of image intensity inhomogeneity and parallel imaging reconstruction

We evaluate a wavelet-based algorithm to estimate the coil sensitivity modulation from surface coils. This information is used to improve the image homogeneity of magnetic resonance imaging when a surface coil is used for reception, and to increase image encoding speed by reconstructing images from under-sampled (aliased) acquisitions using parallel magnetic resonance imaging (MRI) methods for higher spatiotemporal image resolutions. The proposed algorithm estimates the spatial sensitivity profile of surface coils from the original anatomical images directly without using the body coil for additional reference scans or using coil position markers for electromagnetic model-based calculations. No prior knowledge about the anatomy is required for the application of the algorithm. The estimation of the coil sensitivity profile based on the wavelet transform of the original image data was found to provide a robust method for removing the slowly varying spatial sensitivity pattern of the surface coil image and recovering full FOV images from two-fold acceleration in 8-channel parallel MRI. The results, using bi-orthogonal Daubechies 97 wavelets and other members in this family, are evaluated for T1-weighted and T2-weighted brain imaging.     

Cell detachment method using shock-wave-induced cavitation

The detachment of adherent HeLa cells from a substrate after the interaction with a shock wave is analyzed. Cavitation bubbles are formed in the trailing, negative pressure cycle following the shock front. We find that the regions of cell detachment are strongly correlated with spatial presence of cavitation bubbles. It is shown that the cavitation bubble collapse generates a transient high-speed flow along the substrate surface leading to rapid detachment of the cells. Flow trajectories are reconstructed from the video recordings using robust image-processing methods. From these trajectories, an estimate of the shear stress acting on the cells is obtained and the area of detachment is estimated with a kinetic model. Furthermore, it is suggested that the application of shock waves extends the known methods of cell detachment with the ability to control the process in space and time. (E-mail: c.d.ohl@tn.utwente.nl)     

Depersonalization, Self-Esteem and Body Image in Male-to-Female Transsexuals Compared to Male and Female Controls

Whether postoperative male-to-female transsexuals differ in regard to measures of self- and body image from a nontranssexual control group was investigated. A group of 30 postoperative male-to-female transsexuals and control groups of 30 males and 30 females completed self-report measures (depersonalization, self-esteem, gender identity traits, body image). Results showed that transsexuals and males scored higher on self-esteem and dynamic body image than the females did. No differences between the groups were found in terms of depersonalization and satisfaction. Transsexuals and females described themselves as more feminine than males. Regarding sex-role orientation, more androgynous subjects were found among transsexuals than in the control groups. General satisfaction is associated with feminine and masculine traits in transsexuals. Results are discussed in context of the function of these personality features for the identity development of male-to-female transsexuals.     

Relationship of Estrogen and Progesterone Receptor Protein Levels in Carcinomatous and Adjacent Non-Neoplastic Epithelium of the Breast: A Histopathologic and Image Cytometric Study

Background. Results of a previous study demonstrating a correlation between steroid hormone receptor concentrations in benign and tumor tissue in patients with breast carcinoma suggest that receptor levels in breast epithelium undergoing malignant transformation may play a role in determining the receptor levels in the resulting carcinoma. Data used in that study were derived from ligand binding assays and may reflect shortcomings inherent in this methodology, particularly the dilution of receptor proteins from benign and malignant epithelial cells by stromal components. Methods. We performed a correlation study of steroid hormone receptor expression in benign and malignant breast epithelial cells using computerized image cytometry and histologic sections stained for estrogen (ER) and progesterone receptor (PR), avoiding the problems of contribution of stromal cells to the measurements and uncertainty about the histologic composition of the sample. Sections which contained both tumor and non-neoplastic breast elements were obtained from surgical specimens from 50 patients with breast carcinoma. Results. Positive area (PA) scores for ER in benign and malignant epithelium showed direct correlation that was significant (r=0.46, p<0.001), whereas those for PR, although trended in the same direction, did not (r=0.17, p>0.2). PA levels for both receptor proteins were higher in benign breast epithelium with proliferative features, compared to non-proliferative benign epithelium, and in tumors when the associated benign tissue had proliferative changes, but neither of these differences were statistically significant, suggesting that the correlation of ER levels in benign and malignant epithelium was not simply a function of proliferative change. Conclusion. Our results provide support for the concept that ER expression in breast carcinoma depends partially on epithelial cell receptor levels in the breast in which it arises, but not for the analogous hypothesis for PR. When costs and benefits of tamoxifen chemoprevention are weighed for a patient at risk for breast carcinoma, and when cyto- or histopathologic breast tissue specimens are available, it may be reasonable to include breast epithelial ER levels among the factors considered in making the treatment decision.     

Presentation of striatal hyperintensity on T1-weighted MRI in patients with hemiballism-hemichorea caused by non-ketotic hyperglycemia: report of seven new cases and a review of literature

Recent studies have shown unique clinicoradiologic characteristics in patients with hemiballism-hemichorea (HB-HC) caused by non-ketotic hyperglycemia; however, there is still a limited number of patients being reported. We report 7 patients (3 males and 4 females) with this type of dyskinesia, whose ages ranged from 60 to 84 years. Brain CT of these patients showed hyperdensity in the contralateral striatum, corresponding with MRI studies that showed an increased signal intensity on T1-weighted images and a decreased signal on T2-weighted images. After metabolic control had been achieved, the hyperkinetic state of these patients abruptly ceased. Follow-up neuroimaging studies in 2 patients documentied complete resolution of the striatal hyperintensity on brain CT and MRI after 3 months and 6 months, respectively. A review of patients with HB-HC caused by non-ketotic hyperglycemia reported formerly and in the present study shows that the dyskinesia tends to occur in aged diabetic patients. The age of patients with dyskinesia secondary to cerebral infarction is generelly much lower. We also found that 86 % (30 out of 35 cases) patients reported with HB-HC caused by non-ketotic hyperglycemia were Asians. The prognosis of the dyskinesia was excellent, and the radiological abnormalities are completely reversible. Received: 2 November 2000 / Received in revised form: 1 February 2001 / Accepted: 3 March 2001     

Laser Doppler velocimetry and flow visualization studies in the regurgitant leakage flow region of three mechanical mitral valves

Streak line flow visualization and laser Doppler velocimetry (LDV) were conducted in the regurgitant leakage flow region of 3 mechanical heart valve types: CarboMedics, Medtronic Hall, and St. Jude Medical. Streak line flow visualization identified regions of high regurgitant flow, and LDV measurements were focused on those locations. Maximum regurgitant flow velocities after valve closure ranged from 0.7 to 2.6 m/s, and maximum Reynolds shear stress after valve closure ranged from 450 to 3,600 dyne/cm2. These data indicate that leakage flows can generate turbulent jets with elevated Reynolds stresses even in bileaflet valves.     

Reliability and reproducibility of brain tissue volumetry from segmented MR scans

Reliable measurement of different tissue volumes in the living brain is of great importance for human brain research. In this article, we report on the inter- and intraoperator reliability and scan-rescan reproducibility of segmented intracranial tissue volumes from MR images using the image analysis software suite BRAINS. The absolute data of tissue volume measurements are also presented. The reliability and consistency of the measurements of the segmented volumes were excellent. The segmentation is robust and rapid and the volume measurements are plausible and suitable for quantitative studies in clinical brain research. Received: 24 April 2001 / Accepted: 24 September 2001