Objective The objective of this study was to clarify differences in bacterial accumulation between gastrointestinal cancer patients who underwent severely invasive surgery and those who underwent minimally invasive surgery.Material and Methods We performed a preliminary investigation of gastrointestinal cancer patients who were treated at the Department of Surgery, Takarazuka Municipal Hospital, from 2015 to 2017 (n=71; 42 laparoscopic surgery, 29 open surgery) to determine changes in bacterial numbers at different sites of the oral cavity (tongue dorsum, gingiva of upper anterior teeth, palatoglossal arch), as well as mouth dryness and tongue coating indices. Specifically, patients received professional tooth cleaning (PTC), scaling, tongue cleaning, and self-care instruction regarding tooth brushing from a dental hygienist a day before the operation. Professional oral health care was also performed by a dental hygienist two and seven days after surgery. Oral bacteria numbers were determined using a bacterial counter with a dielectrophoretic impedance measurement method.Results The number of bacteria at all three examined sites were significantly higher in the open surgery group when compared to the laparoscopic surgery group on the second postoperative day. Relevantly, bacterial count in samples from the gingiva of the upper anterior teeth remained greater seven days after the operation in patients who underwent open surgery. Furthermore, the dry mouth index level was higher in the open surgery group when compared to the laparoscopic surgery group on postoperative days 2 and 7.Conclusions Even with regular oral health care, bacterial numbers remained high in the upper incisor tooth gingiva in gastrointestinal cancer patients who received open surgery. Additional procedures are likely needed to effectively reduce the number of bacteria in the gingival area associated with the upper anterior teeth.
In order to investigate the radioresistance mechanism of human carcinoma cells, we measured intracellular manganese‐ (Mn‐) and copper/zinc‐ (Cu/Zn‐) superoxide dismutases (SODs), glutathi‐one (GSH) and poly(ADF‐ribose) polymerase (PARP) in radioresistant N10 and its parental KB cell lines. The Mn‐SOD level was 1.3‐fold less in N10 than in KB, but Mn‐SOD was induced at 1.3 to 1.5‐fold higher level in N10 than in KB by X‐irradiation (4‐ Gy). Cu/Zn‐SOD in N10 showed a higher level than that in KB both without and with irradiation. In addition, N10 had a 1.65‐fold higher GSH level than did KB and became radiosensitive on treatment with buthionine sulfoximine, an inhibitor of GSH. Furthermore, PARP mRNA was highly expressed in N10 as compared to KB under unirradiated conditions. X‐Irradiation reduced the PARP mRNA level in KB in a time‐dependent manner, whereas the PARP mRNA level in N10 was still high at 6 h postirradiation. Assay for PARP activity demonstrated an approximately 3‐fold higher activity in N10 than in KB under unirradiated conditions. X‐Irradiation caused a rapid induction of PARP activity within 1 h in both cell lines, but treatment of cells with nicotinamide, a PARP inhibitor, markedly reduced the enzyme induction in N10, but not in KB, and potentiated the radiosensitivity in N10. These factors may all contribute to the radioresistance of the N10 cell line.
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