Okayama Igakkai Zasshi (Journal of Okayama Medical Association)

Show abstractHide abstract

Titanium dioxide (TiO₂) photocatalysis generates reactive oxygen species such as ・OH and ・O₂-, which can effectively eliminate organic compounds. In the present study, we evaluated the antibacterial and antifungal effects of TiO₂-coated ceramic air filters in both laboratory and hospital settings. Photocatalysis with the TiO₂-coated ceramic filter effectively inactivated all 4 pathogenic organisms tested. Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. After the photocatalysis reaction for 4 h under UV-A (365nm, 250μW/cm²) irradiation, the percentage reductions of the number of E. coli, P. aeruginosa, S. aureus, C. albicans cells were 99.9%, 98.9%, 97.7% and 99.9%, respectively, indicating that Gram-negative bacteria are more susceptible to such photocatalysis than Gram-positive bacteria. Scanning electron microscopic analysis showed damage to the cytoplasmic membrane and cell wall by photocatalysis : consistent with above observations, the morphological change of Gram-negative E. coli was greater than that of Gram-positive S. aureus. Further, an air cleaner equipped with a TiO₂-coated ceramic filter significantly decreased the number of bacteria floating in hospitals. These results indicate that air cleaners with TiO₂-coated ceramic filters could be useful in reducing the incidence of nosocomial infections.

View full abstract

Download PDF (1873K)

Clostridium botulinum produces seven neurotoxin (NTX) serotypes, classified from as A to G. In culture, NTX forms protein complexes by association with non-toxic components, such as nontoxic-nonhemagglutinin (NTNH) and hemagglutinins (HA1, HA2, HA3). C. botulinum serotype A produces three types of toxin complexes, M-toxin (NTX and NTNH), L-toxin (M-toxin and HAs) and LL-toxin (dimer of L-toxin). In this study, I found three HA complexes in the culture of a nontoxigenic mutant serotype A lacking ntx and ntnh expression. The HA complexes displayed similar banding patterns on SDS-PAGE, but the staining intensities of the HA1 and HA2 bands were different. In addition, their native-PAGE banding profiles exhibited different behaviors. The large-molecular-size HA complex showed the highest activity, similar to that of an L-toxin. Based on the combined results of the PAGE and gel-filtration profiles, the differences in molecular size among the three HA complexes were thought to be caused by different numbers of HA1 and HA2 molecules. This paper reports for the first time the purification and characterization of a native HA complex of serotype A, and suggests that the HA can form complex structures without NTX and NTNH. This may help in understanding the toxin complex assembly pathway.

View full abstract

We experienced a case of esophageal carcinosarcoma with a component of small cell carcinoma. The patient was a 73-year-old man. We administered chemotherapy of CDDP+VP-16, and performed an operation after 2 courses of this chemotherapy. Subtotal esophagectomy and reconstruction with the small intestine was performed. More than three years after resection, he remains alive and recurrence-free. There are few cases of esophageal carcinosarcoma and small cell carcinoma. We report this rare case herein.

View full abstract

Transomental hernia often develops into strangulated ileus. We report on an 81-year-old man with strangulated ileus due to transomental hernia, diagnosed preoperatively by abdominal CT. The patient was referred to our surgical division because of progressive abdominal pain and vomiting. He had no history of laparotomy. An abdominal CT scan showed dilated small intestinal loops with intraluminal air and strangulated small intestinal loops with engorged mesenteric vessels. We diagnosed this as a strangulated internal hernia due to transomental hernia and conducted an emergency laparotomy. The jejunum had herniated through an abnormal hiatus of the greater omentum to the peritoneal cavity. The strangulated intestinal loop, about 15 cm long, was released and the postoperative course was uneventful. In the absence of a previous laparotomy, the differential diagnosis of intestinal obstruction should include internal hernia. An abdominal CT scan is useful for the preoperative and prompt diagnosis of transomental hernia.

View full abstract