High-precision alignment of electron tomography tilt series using markers formed in helium-ion microscope.

Tungsten nanodots formed in a helium-ion microscope (HIM) provide a practical means of aligning markers of electron tomography tilt series with a high degree of precision. The nanodots were formed using a HIM equipped with a W(CO)6 gas injection system, enabling the precise placement of the nanodots at desired locations of a sample. Template matching was applied to the markers formed in the HIM to detect the positions automatically. The relation between the positions of the markers and the accuracy of the alignment was also determined in order to achieve precise alignment. The method was applied to the markers in order to reconstruct three-dimensional (3D) images of a rod-shaped specimen that contained a 65-nm-diameter via structure in a Cu/Low-k interconnect.

Coupled tomography and distinct-element-method approach to exploring the granular media microstructure in a jamming hourglass.

We describe an approach for exploring microscopic properties of granular media that couples x-ray microtomography and distinct-element-method (DEM) simulations through image analysis. We illustrate it via the study of the intriguing phenomenon of instant arching in an hourglass (in our case a cylinder filled with a polydisperse mixture of glass beads that has a small circular shutter in the bottom). X-ray tomography provides three-dimensional snapshots of the microscopic conditions of the system both prior to opening the shutter, and thereafter, once jamming is completed. The process time in between is bridged using DEM simulation, which settles to positions in remarkably good agreement with the x-ray images. Specifically designed image analysis procedures accurately extract the geometrical information, i.e., the positions and sizes of the beads, from the raw x-ray tomographs, and compress the data representation from initially 5 gigabytes to a few tens of kilobytes per tomograph. The scope of the approach is explored through a sensitivity analysis to input data perturbations in both bead sizes and positions. We establish that accuracy of size--much more than position--estimates is critical, thus explaining the difficulty in considering a mixture of beads of different sizes. We further point to limits in the replication ability of granular flows away from equilibrium; i.e., the difficulty of numerically reproducing chaotic motion.

CT virtual pancreatoscopy: a new method for diagnosing intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

BACKGROUND: We sought to validate computed tomographic virtual pancreatoscopy (CT-VP) created by multidetector row CT (MD-CT) in the clinical diagnosis of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. METHODS: Five cases of pancreatic IPMNs were included in this study. A nasopancreatic drainage tube was inserted and the pancreatic duct was filled with contrast medium, after which an upper abdominal scan was performed by MD-CT. CT-VP and three-dimensional (3D) CT pancreatographic images were created using a workstation and compared with images by conventional diagnostic techniques. All cases were evaluated by endoscopic retrograde pancreatography (ERP) and three cases of main duct type were assessed by intraoperative real pancreatoscopy (RP). RESULTS: In the main duct cases, papillary projections in the main pancreatic duct and branch orifices were clearly detected by CT-VP. These lesions and structures were confirmed by intraoperative RP, and the CT-VP images were clearer than RP images. In branch cases, a surface-rendering method allowed protruding lesions to be clearly detected in the dilated branches. CONCLUSION: Compared with conventional ERP or RP, CT-VP and 3D-CT pancreatographic images were finer in quality, and the procedures were less invasive, faster, and less expensive. The potential shown by CT-VP with 3D-CT pancreatography in the clinical diagnosis of pancreatic IPMNs suggests that this approach may replace ERP in the near future.

Production and characterization of recombinant human anti-HBs Fab antibodies.

Recombinant human Fab antibodies were generated with different reactivities against the hepatitis B virus surface (HBs) antigen. To isolate the antibodies, a method was used that combined transformation of human B cells by Epstein-Barr virus (EBV) infection with a primer-vector system developed for isolating DNA fragments of human Ig Fab portions. With this method, monoclonal and oligoclonal cell lines producing anti-HBs antibodies were established and three anti-HBs Fab antibodies were isolated from two of these cell lines. From analysis of affinity characteristics, immunohistochemical activity, and cytolysis activity, these three Fab antibodies were classified into three different groups. The first group had high affinity for HBs, the second had the ability to kill HBV-infected cells, and the third was applicable to immunohistochemical staining with HBV-infected cells. The combined effect of these antibodies was also investigated by complement-dependent cytotoxicity assay.

Screening of dairy yeast strains for probiotic applications.

To evaluate the potential of yeasts of dairy origin as probiotics, we tested 8 species including Candida humilis, Debaryomyces hansenii, Debaryomyces occidentalis, Kluyveromyces lactis, Kluyveromyces lodderae, Kluyveromyces marxianus, Saccharomyces cerevisiae, and Yarrowia lipolytica, isolated from commercial blue cheese and kefir. Strains were randomly selected from each species and tested for their ability to adhere to human enterocyte-like Caco-2 cells in culture. Among the 8 species, K. lactis showed higher adhesive ability than K. marxianus, K. lodderae, and D. hansenii. The other 4 species were poorly adhesive. All species other than K. marxianus and C. humilis were resistant to acidic conditions. In the presence of bile acid, growth inhibition was undetectable when incubation was carried out at 27 degrees C; however, it was evident for C. humilis and a strain of D. occidentalis when incubated at 37 degrees C. Moreover, the influence of proteinase treatment of living cells of K. lactis and K. lodderae on their adhesion to Caco-2 cells was evaluated. Although a slight reduction was recognized when K. lactis was treated with proteinase K, the influence of intestinal protease treatments of pepsin followed by trypsin was negligible. These results indicated that a proteinaceous factor was unlikely to be involved in adhesion of K. lactis and K. lodderae to Caco-2 cells. No stimulation of IL-8 synthesis by Caco-2 cells was recognized in the presence of K. lactis. In conclusion, K. lactis was the most attractive to continue study for use as probiotic microorganisms.

Mild hypothermia inhibits IL-10 production in peripheral blood mononuclear cells.

BACKGROUND: Hypothermia is often associated with compromised host defenses and infections. Deterioration of immune functions related to hypothermia have been investigated, but the involvement of cytokines in host defense mechanisms and in infection remains unclear. Therefore, we determined whether mild hypothermia affects the production of several types of cytokines in peripheral blood mononuclear cells (PBMCs), and the balance between pro-inflammatory and anti-inflammatory states. METHODS: PBMCs obtained from 12 healthy humans were cultured with phytohemagglutinin (PHA) in normothermic (37 degrees C: control) or hypothermic (33 degrees C) conditions for 24 h. The production levels of tumor necrosis factor (TNF)-alpha, the interleukins (ILs) IL-6, IL-8 and IL-10, and interferon (IFN)-gamma in the culture supernatants were measured by means of enzyme-linked immunosorbent assay (ELISA). RESULTS: Under hypothermic conditions (33 degrees C), PHA-induced production of IL-10 and IFN-gamma in PBMCs was significantly lower, by 34% and 84%, respectively, when compared with controls, while production of TNF-alpha, IL-6 and IL-8 did not change. The magnitude of reduction of IL-10 in hypothermic conditions resulted in IL-10/pro-inflammatory cytokine ratios decreasing to approximately 30-45% of those of controls. CONCLUSIONS: The present study clearly demonstrates that mild hypothermia (33 degrees C) inhibits IL-10 and IFN-gamma production in cultured PBMCs. The profound inhibition of IL-10 and the pro-inflammatory reaction-dominated state induced suggests that the host defense mechanism against secondary infection may be maintained rather than inhibited in hypothermia. Thus, the reduction of IL-10 could be an important characteristic of immune responses in mild hypothermia.

No evidence of PEG1/MEST gene mutations in Silver-Russell syndrome patients.

Silver-Russell syndrome (SRS) is characterized by prenatal and postnatal growth retardation with morphologic anomalies. Maternal uniparental disomy 7 has been reported in some SRS patients. PEG1/MEST is an imprinted gene on chromosome 7q32 that is expressed only from the paternal allele and is a candidate gene for SRS. To clarify its biological function and role in SRS, we screened PEG1/MEST abnormalities in 15 SRS patients from various standpoints. In the lymphocytes of SRS patients, no aberrant expression patterns of two splice variants (alpha and beta) of PEG1/MEST were detected when they were compared with normal samples. Direct sequence analysis failed to detect any mutations in the PEG1/MEST alpha coding region, and there were no significant mutations in the 5'-flanking upstream region containing the predicted promoter and the highly conserved human/mouse genomic region. Differential methylation patterns of the CpG island for PEG1/MEST alpha were normally maintained and resulted in the same pattern as in the normal control, suggesting that there was no loss of imprinting. These findings suggest that PEG1/MEST can be excluded as a major determinant of SRS.

[Two patients with Bartonella henselae infection from a dog].

Two patients were reported as having been infected with Bartonella henselae after having contact with a dog. Both of the patients owned a dog, but had no contact with cats. One patient was a 10-year-old boy who had experienced a fever of 38-39 degrees C for 11 days, as well as having bilateral cervical lymphadenopathy. The boy's serum IgM antibodies to B. henselae were negative on the 6th and 16th day of his illness, whereas his IgG value, using indirect fluorescence antibody (IFA) method, was found to be elevated from 1:256 to 1:1,024. B. henselae DNA was detected, by PCR method, in swabs from the gingiva and buccal membrane of the dog with which the boy had been in contact. The boy was first treated with cefdinir (300 mg daily) for 6 days without beneficial effect. He responded, however, to minocycline (100 mg daily) with symptom resolution in four days. The other patient was a 64-year-old man who had experienced a fever of 38-39 degrees C for 27 days, as well as having right inguinal lymphadenopathy. The man's serum IgM antibody to B. henselae was negative, although his IgG value, determined by IFA, was 1:1,024. In addition, B. henselae DNA was detected, by PCR method, in parafin-embedded tissue obtained from the biopsied inguinal lymph nodes. The man was treated with cefazolin (2 g daily). His fever resolved, but his lymph nodes remained swollen. After a regimen of erythromycin (1,200 mg daily), the swelling in his inguinal lymphnodes gradually disappeared. Careful review of suspected CSD victims' history of contact with animals is important in making a prompt diagnosis of B. henselae infection.

[An adult case of systemic cat-scratch disease with hepatosplenic involvement].

A previously healthy 25-year-old female was admitted to our hospital in November, 1997, for treatment of a spike-fever of 2 weeks' duration. She had a cat in her house but reported no history of cat bites or scratches. No peripheral lymphadenopathy was detected. White blood cell count was within normal limits, but an increased C-reactive protein level of 11.4 mg/dl was noted. Infectious disease was suspected but ruled out as blood cultures were negative. Empiric therapy with clarithromyoin, isoniazid, and rifampicin was ineffective. In January, 1998, abdominal ultrasonogram revealed multiple hypoechoic mass lesions in the spleen and liver, and a splenectomy was performed in March. Histopathologic examination showed numerous necrotizing and caseating granulomas, which tested positive for Bartonella henselae DNA by PCR. Furthermore, the patient tested positive for B. henselae antibody by immunofluorescence assay. A diagnosis of systemic cat-scratch disease with hepatospnenic involvement was made. Combination therapy with minocycline, sulbactam/cefoperazone, and tosufloxacin was administered and her inflammatory findings improved gradually. We report an adult case of systemic cat-scratch disease with liver and spleen involvement in the non-immunocompromised host.

[Serological cross-reaction among Bartonella henselae, Chlamydia pneumoniae and Coxiella burnetii by indirect fluorescence antibody method].

We studied the serological cross-reactions among Bartonella henselae, Chlamydia pneumoniae and Coxiella burnetii by indirect fluorescence antibody (IFA) method, using sera from 8 patients with cat scratch disease (CSD), 13 patients with C. pneumoniae infection and 12 patients with acute Q fever. B. henselae IgG antibody was negative in 13 patients with C. pneumoniae infection, and was positive in 3 (titers being 1:64) of 12 patients with Q fever, whereas B. henselae IgM antibody was negative in all the patients with C. pneumoniae infection or Q fever. C. burnetii IgG antibody was removed by absorption of these 3 sera with C. burnetii antigens, whereas B. henselae IgG antibody did not change. C. pneumoniae IgG antibody was positive in 3 (titers being 1:125 in two, 1:32 in one) of 8 patients with CSD. Both C. pneumoniae and B. henselae IgG antibody titers were significantly reduced by absorption of these 3 sera with B. henselae antigens. C. burnetii IgG or IgM antibodies were negative in all patients with CSD. In conclusion, no serological cross-reaction between B. henselae and C. burnetii was observed. On the other hand. B. henselae IgG antibody cross-reacted to C. pneumoniae antigens, whereas C. pneumoniae IgG antibody did not cross-react to B. henselae antigens. Our findings suggest that determination of B. henselae IgG or IgM antibodies were not influenced by C. pneumoniae and C. burnetii antigens.