Stem cell traits in long-term co-culture revealed by time-lapse imaging.

A deeper understanding of stem cell niche engagement and subsequent behaviors would be enhanced by technologies enabling the tracking of individual stem cells at the clonal level in long-term co-culture (LTC), which mimics the complexity of the bone marrow microenvironment in vivo. Here, we report the application of time-lapse imaging with intermittent fluorescence for tracking well-defined populations of GFP(+) murine hematopoietic stem cells (HSCs) using LTC for >5 weeks. Long-term (LT) and short-term (ST) repopulating HSCs and hematopoietic progenitor cells (HPCs) were compared. The transition from cobblestone areas (CAs) under the stromal cell mantle into dispersed migrating cells on top of the stroma (COS) were directly observed. The ST-HSC and LT-HSC were able to initiate multiple waves of CA formation and COS expansion beyond 2 and 4 weeks, respectively. Retrospective tracking of individual CA forming cell (CAFC) revealed a preference for residing under stroma before the first division and a longer interval before first division for LT-HSC. Inability to maintain quiescence in subsequent divisions was revealed. Our study represents an important starting point from which the LTC system can be augmented to provide a better in vitro model for bone marrow stem cell niches.

Expansion of hematopoietic stem cells in vitro as a model system for human tissue engineering.

The authors have taken a new approach to finding optimal conditions for stimulating conservative division of single isolated CD34(+)lin(-) hematopoietic stem cell candidates from human umbilical cord blood. The approach required the design and development of a novel multi-well single cell combinatorial culture system. This system incorporates the use of a multi-well tissue culture plate in which each well receives a single hematopoietic stem cell candidate. During an experiment lasting several days to weeks, each cell-containing well is moved sequentially and serially to a microscopic imaging system. This movement is facilitated by computer control of a motorized stage and stabilization of the experiment in an environmentally controlled Biobox built on the microscopic stage. New image analysis software facilitates tracking of cell movement, recording the time of cell division, and immunophenotyping of multiple, individual, or recently doubled cells in real time by a robotically controlled pipetting station. The principles of single cell culture should help solve many problems in human hematopoietic stem cell expansion and may be applicable to a wide range of other systems of interest in tissue engineering.

Poor design of local exhaust hood leads to radioactive release in the work area.

At a U.S. Department of Energy (DOE) waste handling facility, transuranic waste contained in standard 208-L (55-gallon) drums was being prepared to meet the DOE's Waste Isolation Pilot Project Waste Acceptance Criteria. During a particular waste handling operation, it was necessary for the workers to open several 208-L drums with TRU waste and prepare the waste to meet the WIPP Waste Acceptance Criteria. This operation was performed while the waste drums where positioned adjacent to a drum ventilator, which was designed to capture emissions generated from the drums during waste handling activities. During this activity, the continuous air monitor alarmed and reached an instantaneous air concentration of 0.1 Bq m(-3), or a factor of 300 times higher than the derived air concentration for inhalation class W 239Pu. The DOE conducted an investigation to determine why the drum ventilator did not control the transuranic emissions and to evaluate possible improvements to the drum ventilator and exposure controls. By adding upper and lower flanges to the drum ventilator, the capture velocity was increased by 88% without increasing the fan's speed. Adding flanges is a simple and inexpensive modification that enhances the performance of the drum ventilator. In addition to a poor design, the drum ventilator's capture velocity was compromised by competing air velocities that were generated by waste handling activities.

Expansion of hematopoietic stem cells in vitro as a model system for human tissue engineering.

The authors have taken a new approach to finding optimal conditions for stimulating conservative division of single isolated CD34 + lin hematopoietic stem cell candidates from human umbilical cord blood. The approach required the design and development of a novel multi-well single cell combinatorial culture system. This system incorporates the use of a multi-well tissue culture plate in which each well can receive a single hematopoietic stem cell candidate. Sequential movement of each cell-containing well to a microscopic imaging system, serially over a several-day to several-week experiment, is facilitated by computer control of a motorized stage and stabilization of the experiment in an environmentally controlled Bio-box built on the microscope stage. New image analysis software facilitates in the tracking of cell movement, recording of the time of cell division, and immunophenotyping of each of multiple individual or recently doubled cells in real time by a robotically controlled pipetting station. The principles of single cell culture should help solve many problems in human hematopoietic stem cell expansion and also may be applicable to a wide range of other systems of interest in tissue engineering.

Incidence, significance and remission of tubal spasm during attempted hysteroscopic tubal sterilization.

Four hundred three attempted hysteroscopic tubal sterilizations were performed. Tubal spasm was encountered in 37 cases (9.2%) and prevented bilateral placement of tubal plugs in 16 of those cases. There was some evidence that glucagon was associated with a higher rate of remission and that women using barrier birth control methods experienced a lower incidence of tubal spasm. A number of other factors were found to be unrelated to tubal spasm and its remission.

Hysteroscopic tubal occlusion with formed-in-place silicone plugs: a clinical review.

The present study is a detailed review of 415 patients undergoing sterilization under local anesthesia with hysteroscopically placed silicone plugs. The authors compiled 3200 woman-months after sterilization without a pregnancy. Up to 90% of women undergoing this procedure in the office have successful completion. The difficulties with the method are outlined, unsuccessful procedures categorized, and radiographs presented, and the outlook for the future is discussed. The method is seen as a viable alternative to laparoscopic sterilization.

The incidence of intrauterine abnormalities found at hysteroscopy in patients undergoing elective hysteroscopic sterilization.

Hysteroscopic findings in 323 consecutive women requesting transcervical sterilization were analyzed. A remarkably low incidence of intrauterine abnormalities (13%) was found in this group of asymptomatic women as compared to that found in large series of women who experienced abnormal uterine bleeding or infertility. The dramatic difference in the incidence of abnormal hysteroscopic findings between these patient groups supports the concept of routinely performing hysteroscopy when evaluating women with infertility or abnormal uterine bleeding. It also sets a baseline for the prevalence of hysteroscopically demonstrable intrauterine pathology in an asymptomatic population.

Hysteroscopic tubal occlusion with formed-in-place silicone plugs.

One hundred sixty-one patients underwent hysteroscopic tubal occlusion with formed-in-place silicone rubber plugs over 8 months. In 86% bilateral plug placement was successful with the patient under local anesthesia in an office setting. There have been no pregnancies in 683 woman-months of sterilization to date. The procedure is seen as an effective alternative to current methods of female sterilization. The advantage of the procedure over laparoscopic sterilization is discussed.

Pentazocine abuse. Report of a case with pulmonary arterial cellulose granulomas and pulmonary hypertension.

We report a patient who developed pulmonary hypertension following repeated intravenous injection of dissolved pentazocine tablets. Through analysis of lung biopsy material, this was shown to be due to embolization of the cellulose filler in the tablet and the tissue reaction it produced. Administration of prednisone appeared to improve the patient's clinical state.