[Pancreatic Adenosquamous Carcinoma That Developed after Resection of IPMA in the Pancreatic Tail].

Pancreatic adenosquamous carcinoma coexisting with intraductal papillary mucinous neoplasm(IPMN)is extremely rare. We report a rare case of pancreatic adenosquamous carcinoma that developed after resection of intraductal papillary mucinous adenoma(IPMA). A 67-year-old man was suspected of having a pancreatic cystic lesion. MRCP demonstrated a cystic lesion measuring 25mm in the pancreatic tail, which had an enhanced nodule. We therefore diagnosed branch duct type IPMN of the pancreas. Although pancreatic juice cytology did not indicate malignancy, we performed laparoscope-assisted distal pancreatectomy. The reason why the IPMN lesion had an enhanced nodule. The histopathological diagnosis was IPMA without malignancy. One year and 5 months after surgery, blood analysis showed an elevated tumor marker level, and abdominal CT demonstrated a pancreatic head tumor with lymphadenopathy. EUS-FNA was performed and the patient was diagnosed with pancreatic adenosquamous carcinoma based on immunohistochemical staining. We administered chemotherapy with gemcitabine and S-1. After 3 courses of this chemotherapy, the size of the pancreatic tumor and the tumor marker level decreased. The patient achieved a partial response. He is still receiving chemotherapy after 7 courses.

Biological oxidation of arsenite in synthetic groundwater using immobilised bacteria.

Biological oxidation of arsenite (As(III)) in synthetic groundwater was examined by using arsenite oxidising bacteria (AOB) isolated from an activated sludge. The phylogenetic analysis indicated that the isolated AOB was closely related to Ensifer adhaerens. Batch experiments showed that for an As(III) oxidation with the isolated AOB the optimum ratio of nitrogen source (NH4-N) concentration to As(III) concentration was 0.5 (52 mg/L-110 mg/L) and the isolated AOB preferred pH values ranging from 6 to 8, and water temperatures greater than 20 °C. Further continuous experiments were conducted using a bioreactor with immobilised AOB. With an initial As(III) concentration of 1 mg/L at a hydraulic retention time (HRT) of 1 h, an As(III) oxidation rate was around 1 × 10⁻9 µg/cell/min and an As(III) oxidation efficiency of 92% was achieved. Although the maximum oxidation rate measured at an HRT of 0.5 h was 2.1 × 10⁻9 µg/cell/min, the oxidation efficiency decreased to 87%. These results advocate that a biological process involving immobilised AOB may be useful as an economical and environmentally friendly pre-treatment step for As removal from groundwater.

Etiological agents of lower respiratory tract infections in Japanese children.

To investigate the etiology of pediatric community-acquired pneumonia and bronchitis, we conducted a prospective, population-based study covering the total population < 15 years of age in 16 municipalities in Hokkaido, Japan, during the period of April 2000 to March 2001. Chest radiographs were available for all cases (n = 921; 398 as pneumonia and 523 as bronchitis) and paired sera for serologic assays were available for more than half of the cases. The following specimens were also collected: nasopharyngeal swabs for viral, bacteriological, mycoplasmal and chlamydial studies, blood for serology and blood culture. The children were then followed-up on days 3, 7 and 14. Specific infecting organisms were identified in a total of 853 (92.6%) out of 921 patients (398 cases of pneumonia and 523 cases of bronchitis) including 205 with mixed infection as follows: Mycoplasma pneumoniae, 252 (274%) patients; respiratory syncytial (RS) virus, 188 (20.4%); influenza A virus, 110 (11.9%); Streptococcus pneumoniae, 95 (10.3%); Haemophilus influenzae, 90 (9.8%); Haemophilus parainfluenzae, 35 (3.8%); Staphylococcus aureus, 29 (3.1%); adenovirus, 27 (2.9%); Moraxella catarrhalis, 12 (1.3%); Pseudomonas aeruginosa , 7 (0.8%); Chlamydia pneumoniae, 6 (0.7%); and other agents, 2 (0.2%). Mycoplasma infections were seen even in patients less than 5 years and RS and influenza A virus infections in patients more than 5 years of age. The importance of M. pneumoniae and RS virus in the etiology of lower respiratory infections in Japanese children was confirmed.