Etiology and clinical study of community-acquired pneumonia in 157 hospitalized children.

We tried to verify whether the currently employed diagnosis and treatment of community-acquired pneumonia in children were appropriate. For this purpose, we created tentative criteria for the classification of pediatric community-acquired pneumonia. We classified the community-acquired pneumonia into ten categories: (1) bacterial, (2) concomitant viral-bacterial, (3) viral, (4) mycoplasmal, (5) concomitant mycoplasmal-bacterial, (6) concomitant mycoplasmal-viral, (7) chlamydial, (8) concomitant chlamydial-bacterial, (9) concomitant chlamydial-viral, and (10) unknown. Children aged 1 month to 13 years with radiographic and clinical evidence of pneumonia were enrolled. Between October 2001 and September 2002, we enrolled 165 patients. The etiologic agents were determined in 126 of the 157 (80.3%) patients who were finally diagnosed with pneumonia. Two blood cultures were positive for Haemophilus influenzae type b and Streptococcus pneumoniae. A viral infection alone was found in 28 of the 157 patients (17.8%), a bacterial (without mycoplasmal) alone infection in 42 (26.8%), a concomitant viral-bacterial infection in 28 (17.8%), and a mycoplasmal infection in 27 (17.2%) patients. RS virus was identified in 28 patients (17.8%), influenza A in 12 (7.6%), parainfluenza 3 in 8 (5.1%), adenovirus in 8 (5.1%), and influenza B and measles virus in 1 patient each. Streptococcus pneumoniae was the most common cause of bacterial pneumonia. We chose the initial treatment according to clinical and laboratory findings on admission (i.e., patients' age, clinical course, chest X-ray, and laboratory findings). In 68 of the 71 patients with bacterial (without mycoplasmal) pneumonia, an appropriate antibacterial-agent was prescribed. In 25 of the 27 patients with mycoplasmal pneumonia, clindamycin and minocycline were prescribed.

Primary pancreatic plasmacytoma.

We report an extremely rare case of primary pancreatic plasmacytoma. A 56-year-old man had a 4-cm mass in the pancreatic tail and received distal pancreatectomy. This mass mainly consisted of plasma cells, but we failed to demonstrate their monoclonality in spite of the immunohistological staining. One and a half years later, this patient's right inguinal node swelled, and this node also showed a dense plasma cell infiltration. A very precise immunohistological staining was performed for this lymph node and the previous pancreatic mass, and both were diffusely positive for kappa light chain, IgG, and CD38. In the absence of myeloma elsewhere, we thus reached the correct diagnosis of primary pancreatic plasmacytoma, which later metastasized to lymph nodes. In the presence of the plasma cell proliferation in a pancreatic mass, plasmacytoma should be taken into consideration, and a more careful immunohistological staining is definitely necessary.

Combination of alpha-fetoprotein mRNA-based detection of hematogenously disseminating hepatocellular carcinoma cells and analysis of cancer cell membrane fluidity is more accurate in screening patients at risk of postoperative recurrence.

We developed an mRNA-based, highly specific and sensitive method to detect hepatocellular carcinoma cells present in blood. However, the reason for some patients being positive for blood analysis and negative for recurrence has yet to be found. We recently established a method to measure membrane fluidity of hepatocellular carcinoma cells, and used it to analyze the actual membrane fluidity of human hepatocellular carcinoma cells. We found that patients with carcinoma cells with lower membrane fluidity less frequently developed recurrence. The analysis of both membrane fluidity and alpha-fetoprotein mRNA thus greatly increased the accuracy of the prediction of postoperative recurrence.

Successive cultures of mature hepatocytes for hepatocyte autotransplantation to assist liver function after liver resection for cancer.

We developed a method for the rapid successive cultures of adult rat mature hepatocytes on plastic dishes while avoiding viral transformation or co-culture with other cell lines. This method also allows for culturing adult human mature hepatocytes up to the secondary culture. These can be expected to provide a good source for hepatocyte autotransplantation, and, combined with the previously reported methods for the transplantation of hepatocytes into the spleen, a promising option for the support of liver function after liver resection for cancer without the need for immunosuppressive agents.