Comparison of carbon dioxide and normal saline for uterine distension in outpatient hysteroscopy

OBJECTIVE: To evaluate patient acceptance and the clinical feasibility of carbon dioxide compared with normal saline for uterine distension in outpatient hysteroscopy. DESIGN: Prospective, randomized clinical trial. SETTING: Outpatient hysteroscopy clinic in a university hospital. PATIENTS: One hundred fifty-seven patients undergoing outpatient hysteroscopy. INTERVENTIONS: Outpatient hysteroscopy was performed with carbon dioxide or normal saline with endometrial biopsy when indicated. MAIN OUTCOME MEASURES: Need for local anesthesia, cervical dilatation, view of uterine cavity, need to change from carbon dioxide to normal saline distension, procedure time, patient discomfort (lower abdominal pain, shoulder tip pain, nausea) and complications. RESULTS: Carbon dioxide was used for uterine distension in 79 women and normal saline was used in 78. Cervical dilatation was required more often with carbon dioxide hysteroscopy, although there was no increased requirement for local anesthesia. Hysteroscopic vision was similar between the two media, but eight carbon dioxide cases had to be converted to liquid distension. Procedure times were significantly longer for carbon dioxide hysteroscopy as was the occurrence of bubbles during the procedure. Lower abdominal pain and shoulder tip pain were significantly worse with carbon dioxide distension. Although the incidence of nausea and vomiting was higher with the use of carbon dioxide, the differences did not achieve statistical significance. CONCLUSION: The use of normal saline for uterine distension had no adverse affects on the hysteroscopic view. It provided a shorter operating time and was well accepted by patients. Because of its easy availability and low cost, normal saline is an excellent alternative to carbon dioxide in women undergoing outpatient hysteroscopy.     

A method for exposing the internal anatomy of small and delicate tissues for correlated SEM/TEM studies using polyethylene glycol embedding

A method for preparing and handling large, clean, distortion-free cut surfaces through small and delicate tissues for correlated SEM/TEM examination is described. In this method, tissues are fixed according to conventional protocols; however, instead of critical-point-drying after fixation, tissues are first embedded in polyethylene glycol (PEG), a water-soluble waxy solid. Tissue blocks are easily oriented and sectioned to the desired regions, immersed in a solvent to remove PEG, critical-point-dried, and examined with an SEM. The same tissue blocks can be reworked for TEM by immersing in propylene oxide and embedding in an epoxy resin.     

A method for preparing quick-frozen,freeze-substituted cells for transmission electron microscopy and immunocytochemistry

A quick-freeze, freeze-substitution method is described which employs glutaraldehyde as well as osmium tetroxide (OsO₄) in a ‘double-fixation’ protocol comparable to that used for conventional transmission electron microscopy. Cultured cells are quick-frozen in Freon 22 and freeze-substituted in an ethanolic solution of glutaraldehyde. Specimens destined for TEM are postfixed in OsO₄ in acetone, embedded in Epon-Araldite, and sectioned. This method yielded ultrastructural preservation which was comparable to that obtained from methods employing OsO₄ alone as a freeze-substitution fixative. However, if glutaraldehyde is used alone as a freeze-substitution fixative, specimens can be processed for immunocytochemistry without additional treatment with permeabilizing agents.     

Chromosome spatial order in human cells: evidence for early origin and faithful propagation

We have investigated the origin and nature of chromosome spatial order in human cells by analyzing and comparing chromosome distribution patterns of normal cells with cells showing specific chromosome numerical anomalies known to arise early in development. Results show that all chromosomes in normal diploid cells, triploid cells and in cells exhibiting nondisjunction trisomy 21 are incorporated into a single, radial array (rosette) throughout mitosis. Analysis of cells using fluorescence in situ hybridization, digital imaging and computer-assisted image analysis suggests that chromosomes within rosettes are segregated into tandemly linked "haploid sets" containing 23 chromosomes each. In cells exhibiting nondisjunction trisomy 21, the distribution of chromosome 21 homologs in rosettes was such that two of the three homologs were closely juxtaposed, a pattern consistent with our current understanding of the mechanism of chromosomal nondisjunction. Rosettes of cells derived from triploid individuals contained chromosomes segregated into three, tandemly linked haploid sets in which chromosome spatial order was preserved, but with chromosome positional order in one haploid set inverted with respect to the other two sets. The spatial separation of homologs in triploid cells was chromosome specific, providing evidence that chromosomes occupy preferred positions within the haploid sets. Since both triploidy and nondisjunction trisomy 21 are chromosome numerical anomalies that arise extremely early in development (e.g., during meiosis or during the first few mitoses), our results support the idea that normal and abnormal chromosome distribution patterns in mitotic human cells are established early in development, and are propagated faithfully by mitosis throughout development and into adult life. Furthermore, our observations suggest that segregation of chromosome homologs into two haploid sets in normal diploid cells is a remnant of fertilization and, in normal diploid cells, reflects segregation of maternal and paternal chromosomes.     

PECOM--工业报纸生产的支柱

报纸印刷生产线每天必须在较短的时间内印刷报纸,许多年都很稳定可靠。客户期待他们投资的印刷机在很长的时间内能够运行稳定,而印刷系统中每个组件之间的兼容性对此起到很大的作用。老的印刷生产线必须在较长的时间内保持功能稳定并且有一定的可扩展性,所添加的新组件也必须容易操作。然而如果电器的控制不同,供应商不同,就很难满足这些要求,很快就会出现问题。例如,当一个电器的供应商不能再生产某种元件时,就会发生这种现象。但是如果     

A method for studying the three-dimensional organization of cytoskeletal elements of cells: improvements in the polyethylene glycol technique

A method utilizing polyethylene glycol (PEG) as an extractable embedment for electron microscopy is described. Tissues are fixed according to conventional protocols, embedded in PEG, and sectioned. Sections (ranging from 100 to 500 nm in thickness) are mounted on grids, divested of their PEG matrix, critical-point-dried, and examined stereoscopically. This method greatly facilitates studies on the three-dimensional organization of cytoskeletal and cytoplasmic contractile systems in both muscle and nonmuscle cells.     

Studies on dispersed unincubated chick blastoderm cells. II. Formation of contacts and cell sorting in aggregates of unincubated chick blastoderm and heart cells

The configuration of blastoderm-heart cell aggregates after cell sorting depended largely on the proportion of each cell type initially present in the culture. In heterotypic aggregates, blastoderm cells were always found to partially or completely surround heart cells with both cell types retaining their characteristic morphology. Specialized junctions (e.g. desmosomes) developed only between cells of the same type. These observations suggest that blastoderm cells are unable to recognize and form stable contacts with heart cells.