Specificity of Pseudomonas isolates on healthy and Fusarium head blight-infected spikelets of wheat heads.

The specificity of culturable bacteria on healthy and Fusarium head blight (FHB)-infected spikelets of wheat heads was investigated to find a candidate of biocontrol agents against FHB. The bacterial genus Pseudomonas was commonly isolated from the tissues, and phylogenetic analysis using 16S ribosomal RNA gene sequences of isolates of the genera revealed that particular phylogenetic groups in the genus specifically inhabited either healthy or infected spikelet tissues. The specificity of each group was suggested to be due to differences in the ability to form biofilms and colonize spikelet tissues; isolates originated from healthy spikelets formed biofilms on polyvinyl chloride microplate wells and highly colonized the spikelet tissues. Other bacterial groups obtained from FHB-infected spikelets less formed biofilms and attached with low densities on the spikelet tissues. Their colonization on the tissues, however, was promoted when co-inoculated with the causal pathogenic fungus, Fusarium graminearum, and several isolates were observed to smash the mycelia in vivo. Moreover, based on results of in vitro mycelial growth inhibition activity, the diseased tissue-originated isolates were verified to have a negative effect on the fungal growth. These results suggest that Pseudomonas isolates obtained from infected spikelet tissues were highly associated with the FHB pathogen and have potential as candidates for biological control against FHB.

[Two cases of pancreatic cancer with fairly good prognosis].

We report two cases of advanced pancreatic cancer whose prognoses are fairly good with surgery and chemotherapy. Case 1: A 71-year-old male patient was diagnosed as pancreatic head cancer by abdominal ultrasound. The tumor size was about 2 cm in diameter. Whipple's procedure and regional lymphadenectomy were conducted. Pathological diagnosis was pT3N2 with s0 and rp1. Gemcitabine (GEM) was administered in a routine fashion at out-patient clinic. He is free of disease after three years and eight months. Case 2: A 63-year-old male patient was diagnosed as pancreatic head cancer although the mass was not so clearly visible by CT. Pylorus preserving pancreaticoduodenectomy was performed with D2 lymph node dissection. Pathological report was pT3N1 with s0 and rp0. GEM was started six months after the operation but continued for only six months. After the non-treatment interval of six months, GEM was restarted due to the sudden elevation of CA19-9. Soon the number dropped but instead of reaching normal range, it began to increase again. S-1 was added to the regimen which gave a great response. He is well after three and a half years. CA19-9 was almost being normal. Both patients had cancer within the pancreas without an invasion to the surrounding tissue. GEM is a standard regimen for adjuvant chemotherapy. However, S-1 may contribute to the outcome when GEM becomes powerless.

[Gallbladder carcinoma, progressed along cholecystoduodenal fistula--a case report].

A 75-year-old woman had an operation for gallstone ileus without cholecystectomy in other hospital and she was admitted to our hospital because of duodenal adenoma with severe atypia and small carcinoid in proximal duodenal wall. Distal gastrectomy and cholecystectomy were performed. Histological studies revealed the existence of cholecystoduodenal fistula and suggested the existence of gallbladder carcinoma progressed to the duodenal wall through the fistula. Cystic duct dissection and lymph nodes dissection were performed. It has been theorized that a cholecystoduodenal fistula may represent a significant risk factor in the development of gallbladder carcinoma because of the chronic reflux of duodenal contents which includes pancreatic juice. Our case may support this theory. In this case, we thought that the formation of gallbladder cancer could have been avoided if the cholecystectomy was performed in the first operation for gallstone ileus. It is very important that cholecystectomy should be performed when an existence of cholecystoduodenal fistula is highly suspected.