Measurement of particulate matter 2.5 in surgical smoke and its health hazards.

PURPOSE: Surgical smoke is generated during the cauterization, coagulation, and incision of biological tissues by electrocautery, ultrasonic coagulation, incising devices, and lasers. Surgical smoke comprises water, water vapor, steam, and some particulate matter, including bacteria, viruses, cell fragments, and volatile organic compounds, which can pose health risks to the operating room personnel. In this study, we measured the concentration of particulate matter 2.5 (particles with a diameter of ≤ 2.5 µm) in surgical smoke. METHODS: We used digital dust counters for real-time monitoring of particulate matter 2.5 generated intraoperatively in breast and gastrointestinal surgeries performed at our hospitals between 2019 and 2020. RESULTS: Concentrations of particulate matter 2.5 were measured in surgical smoke generated when performing 14 different surgeries. Immediately after electrocautery, the concentration of particulate matter 2.5 increased to 2258 µg/m3 and then, when we stopped using the devices, it decreased rapidly to the initial levels. Interestingly, the concentrations increased after each intermittent electrocautery procedure. Higher concentrations of particulate matter 2.5 were observed during breast surgeries than during laparoscopic procedures. CONCLUSION: Surgical smoke poses potential health risks to operating room personnel by contaminating their breathing zone with high concentrations of particulate matter 2.5. A local exhaust ventilation system is needed to reduce exposure.

Twelve-year experience of office-setting removal of lost intrauterine devices in place for more than 10 years.

Objective: We investigated the effectiveness of removing lost intrauterine devices (IUDs) that had been in place for over 10 years, using Lin's biopsy grasper in an office setting. Methods:This single-centre, retrospective study conducted between March 2006 and June 2018 included 49 women who had had an IUD in place for contraception for more than 10 years and who underwent removal of the lost IUD using Lin's biopsy grasper under transabdominal sonography without use of a tenaculum, anaesthesia and analgesia, after dilation of the cervical os and hysteroscopy. Results: The women's median age was 52 years (range 34-80 years) and the median duration of insertion was 17 years (range 10-43 years). Forty-eight (98%) women had their lost IUD removed using Lin's biopsy grasper. Among the removed IUDs, there were eight FD-1 IUDs with a string, 13 FD-1 IUDs without a string, 13 Chinese IUDs, seven Ota ring IUDs, three KS ring IUDs, two Saf-T-Coil IUDs, two Lippe loop IUDs and one Wing IUD. All women tolerated the procedure and there were no major operative complications. Conclusions: Lin's biopsy grasper was effective in removing IUDs that had been in place for a long time.

p130Cas, Crk-associated substrate, plays important roles in osteoclastic bone resorption.

p130Cas, Crk-associated substrate (Cas), is an adaptor/scaffold protein that plays a central role in actin cytoskeletal reorganization. We previously reported that p130Cas is not tyrosine-phosphorylated in osteoclasts derived from Src-deficient mice, which are congenitally osteopetrotic, suggesting that p130Cas serves as a downstream molecule of c-Src and is involved in osteoclastic bone resorption. However, the physiological role of p130Cas in osteoclasts has not yet been confirmed because the p130Cas-deficient mice displayed embryonic lethality. Osteoclast-specific p130Cas conditional knockout (p130Cas(ΔOCL-) ) mice exhibit a high bone mass phenotype caused by defect in multinucleation and cytoskeleton organization causing bone resorption deficiency. Bone marrow cells from p130Cas(ΔOCL-) mice were able to differentiate into osteoclasts and wild-type cells in vitro. However, osteoclasts from p130Cas(ΔOCL-) mice failed to form actin rings and resorb pits on dentine slices. Although the initial events of osteoclast attachment, such as ß3-integrin or Src phosphorylation, were intact, the Rac1 activity that organizes the actin cytoskeleton was reduced, and its distribution was disrupted in p130Cas(ΔOCL-) osteoclasts. Dedicator of cytokinesis 5 (Dock5), a Rho family guanine nucleotide exchanger, failed to associate with Src or Pyk2 in osteoclasts in the absence of p130Cas. These results strongly indicate that p130Cas plays pivotal roles in osteoclastic bone resorption.