Sylvia Lew

Cytoplasmic granule formation in mouse pancreatic acinar cells. Evidence for formation of immature granules (condensing vacuoles) by aggregation and fusion of progranules of unit size, and for reductions in membrane surface area and immature granule volume during granule maturation

We used a computer-assisted morphometry approach to analyze quantitatively the process of cytoplasmic granule formation in mouse pancreatic acinar cells stimulated with pilocarpine to induce secretion. Our findings suggest that each condensing vacuole/immature granule of pancreatic acinar cells is formed by the progressive aggregation of 106 to 128 “unit progranules” of narrowly fixed volume, define a range of 7.7 to 9.2 for the factor of volume condensation between the largest immature granules and the mature unit granule, and predict that the formation of a single mature unit granule by the aggregation and fusion of unit progranules involves a net reduction of at least 95% in the amount of membrane surface area associated with these structures.

Double mitral valve orifice.

SummaryA two-day-old baby with a type-I truncus arteriosus and double mitral valve orifice is reported. The double mitral valve orifice and additional lesions of each subdivision of the mitral valve were clearly shown by two-dimensional echocardiography. The medial orifice had a cleft leaflet and the lateral one a parachute-like disposition of the tension apparatus. This is the first report of double mitral valve orifice associated with truncus arteriosus, and the first in which anomalies of the subdivisions of the mitral valve were detected by two-dimensional echocardiography.

Morphometric studies of secretory granule formation in mouse pancreatic acinar cells. Dissecting the early structural changes following pilocarpine injection

Secretory granule formation in pancreatic acinar cells is known to involve massive membrane flow. In previous studies we have undertaken morphometry of the regranulation mechanism in these cells and in mast cells as a model for cellular membrane movement. In our current work, electron micrographs of pancreatic acinar cells from ICR mice were taken at several time points after extensive degranulation induced by pilocarpine injection in order to investigate the volume changes of rough endoplasmic reticulum (RER), nucleus, mitochondria and autophagosomes. At 2–4 h after stimulation, when the pancreatic cells demonstrated a complete loss of granules, this was accompanied by an increased proportion of autophagosomal activity. This change primarily reflected a greatly increased proportion of profiles retaining autophagic vacuoles containing recognisable cytoplasmic structures such as mitochondria, granule profiles and fragments of RER. The mitochondrial structures reached a significant maximal size 4 h following injection (before degranulation 0.178±0.028 μm3; at 4 h peak value, 0.535±0.109 μm3). Nucleus size showed an early volume increase approaching a maximum value 2 h following degranulation. The regranulation span was thus divided into 3 stages. The first was the membrane remodelling stage (0–2 h). During this period the volume of the RER and secretory granules was greatly decreased. At the intermediate stage (2–4 h) a significant increase of the synthesis zone was observed within the nucleus. The volume of the mitochondria was increasing. At the last step, the major finding was a significant granule accumulation in parallel with an active Golgi zone.

Changes in the Distribution of Anionic Constituents in Secretory Granules of Mouse Pancreatic Acinar Cells After Pilocarpine-induced Degranulation

We used cationized colloidal gold (CCG) to investigate the distribution of anionic sites in different secretory granules of mouse pancreatic acinar cell regranulation. Localization of anionic sites with CCG was carried out on ultrathin sections of a mouse pancreas, fixed in Karnovskys fixative and OsO4 and embedded in Araldite. After pilocarpinestimulated degranulation, there was a marked diminution in the anionic charge density of immature and mature granules of the 4-hr group (≈43.0 gold particles/μm2) compared to the 8-hr mature granules group (≈64.6 gold particles/μm2). Scattergram analysis to investigate the correlation between section profile size and cationized gold labeling density revealed a reverse correlation, the small granule profiles demonstrated a higher density compared to the larger profiles of the same group. On the basis of these observations, it appears that a post-translational processing of secretory content influences the granule anionic charge and thus may affect the intragranular buffer capacity.

A Novel Urine Cytology Stain for the Detection and Monitoring of Bladder Cancer

PURPOSE CellDetect® is a unique platform technology comprising a proprietary plant extract and 3 dyes that enables color discrimination between malignant (red) and benign (green) cells based on specific metabolic alterations exclusive to the former. Preclinical studies and clinical trials demonstrated the applicability of the new technology in many cell culture lines and various cancers. We explored its performance characteristics in bladder cancer. MATERIALS AND METHODS We performed an open label, 2-step study at tertiary medical centers. The study enrolled patients with newly diagnosed or a history of urothelial carcinoma. Step 1 involved staining archived biopsies. Slides were evaluated by 2 independent pathologists, who determined the concordance of the new staining technology with the hematoxylin and eosin based diagnosis. Step 2 included staining urine specimens with the new method and comparing findings to the patient final diagnosis and the results of standard urine cytology. RESULTS A total of 58 archived biopsies were collected. The concordance of staining using the new platform technology with the hematoxylin and eosin based diagnosis was 100%. The new method applied to 44 urine smears showed 94% sensitivity and 89% specificity to detect urothelial carcinoma. Compared to standard urine cytology the new technology had overall superior sensitivity (94% vs 46%), particularly for low grade tumors (88% vs 17%, each p <0.005). There was no significant difference in specificity between the 2 staining techniques. CONCLUSIONS Findings show the capability of CellDetect to accurately identify urothelial carcinoma. This indicates that the technology can be further developed to provide an alternative urine cytology test with diagnostic value that may have significant clinical benefits.

A Novel Urine-Based Assay for Bladder Cancer Diagnosis: Multi-Institutional Validation Study

BACKGROUND CellDetect is a unique histochemical stain enabling color and morphological discrimination between malignant and benign cells based on differences in metabolic signature. OBJECTIVE The objective of the present study was to validate the performance of this assay in a controlled, blinded, multicenter study. DESIGN, SETTING, AND PARTICIPANTS The study, conducted in nine hospitals, included patients with documented history of bladder cancer, monitored for urothelial carcinoma (UCC) or scheduled for bladder cancer surgery. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Cystoscopy and/or biopsy were used as a reference standard to determine sensitivity and specificity. Smears were stained by CellDetect and interpreted by two cytologists blinded to the patients final diagnosis. The findings were compared with those of standard urine cytology and BTA stat. RESULTS AND LIMITATIONS Two hundred and seventeen voided urine specimens were included. Ninety-six (44%) were positive by histology and 121 (56%) were negative by either cystoscopy or histology. The overall sensitivity of CellDetect was 84%. Notably, the sensitivity for detecting low-grade nonmuscle-invasive bladder cancer tumors was greater than this of BTA stat (78% vs 54%) and more than two-fold higher compared with standard cytology (33%, p ≤ 0.05). The specificity was 84% in patients undergoing routine surveillance by cystoscopy. At a median follow-up of 9 mo, 21% of the patients with positive CellDetect and negative reference standard developed UCC, which was significantly higher compared with the 5% of the true negative cases. Limitations include the lack of instrumental urine samples and the lack of patients with nongenitourinary cancers in the study population. CONCLUSIONS This study validates the performance of CellDetect as a urine-based assay to identify UCC in patients with history of bladder cancer. The high sensitivity was maintained across all cancer grades and stages without compromising the assay specificity. Further studies are required to test whether this novel stain can be incorporated in routine bladder cancer surveillance as a noninvasive alternative to cystoscopy. PATIENT SUMMARY Surveillance of bladder cancer requires frequent invasive procedures. In the present study, we validate the ability of a novel biomarker to accurately identify early-stage tumors in urine specimens for the noninvasive monitoring of patients with history of bladder cancer.

NORMAL PREGNANCY COMPLICATED BY VAGINAL ECTOPIC TROPHOBLASTIC IMPLANTATION; A CASE REPORT

We describe a rare case of ectopic placental tissue, presenting as a vaginal tumor during normal intra-uterine pregnancy. Its clinicopathological features, and its possible relation to placental site trophoblastic tumors are discussed. To the best of our knowledge, this is the first case to be reported in the English literature of such a lesion occurring at this site.