OBJECTIVES:: After standardization of the perioperative management of pancreaticoduodenectomy, we retrospectively compared results in nonstented pancreaticojejunostomy with external-stented pancreaticojejunostomy. METHODS:: The study population included 129 consecutive patients who underwent pancreaticoduodenectomy between 2004 and 2008. The postoperative mortality and morbidity were compared between 51 patients with restrictive use of external stenting (group A) and 78 patients without external stenting (group B). The patient with a pancreatic duct of less than 3 mm in diameter was 31% in group A and 46% in group B. RESULTS:: There were no differences in postoperative morbidity and mortality between the 2 groups. Although the frequency of overall postoperative pancreatic fistula development was significantly higher in group B than in group A (44% vs 27%, P = 0.0004), there was no difference in grade B/C postoperative pancreatic fistula rate (group A: 5.9% vs group B: 14.1%). The length of in-hospital stay in group B was significantly shorter than group A (13 vs 24 days, P < 0.0001). There were no differences in postoperative morbidity and mortality between subgroups that were consisted of patients with small pancreatic duct diameter. CONCLUSION:: This retrospective single-center study showed that nonstented duct-to-mucosa anastomosis was a safe procedure and was associated with a shortened in-hospital stay.

Norovirus (NV) is an important human pathogen that causes epidemic acute nonbacterial gastroenteritis worldwide. Because of the lack of a cell culture system or an animal model for this virus, studies of drinking water treatment such as separation and disinfection processes are still hampered. We successfully estimated NV removal performance during a coagulation-rapid sand filtration process by using recombinant NV virus-like particles (rNV-VLPs) morphologically and antigenically similar to native NV. The behaviors of two widely accepted surrogates for pathogenic waterborne viruses, bacteriophages Qbeta and MS2, were also investigated for comparison with that of rNV-VLPs. Approximately 3-log(10) removals were observed for rNV-VLPs with a dose of 40 muM-Al or -Fe, as polyaluminum chloride at pH 6.8 or ferric chloride at pH 5.8, respectively. Smaller removal ratios were obtained with alum and ferric chloride at pH 6.8. The removal performance for MS2 was somewhat larger than that for rNV-VLPs, meaning that MS2 is not recommended as an appropriate surrogate for native NV. By comparison, the removal performance for Qbeta was similar to, or smaller than, that for rNV-VLPs. However, the removal performances for rNV-VLPs and Qbeta differed between the coagulation process and the following rapid sand filtration process. Therefore, Qbeta also is not recommended as an appropriate surrogate for native NV.

Time-critical extracellular stimuli as well as the intrinsic functions of transcriptional regulatory molecules play essential roles in fate determination and differentiation of mouse primordial germ cells (PGCs). We found that the precursor cells of PGCs require E-cadherin-mediated cell-cell interaction and the functions of transcription factor Oct3/4 to be specified to PGCs. In addition, transcriptional factors commonly regulating a number of PGC-specific genes appear important for PGC development, and we demonstrated that PGC-specific expression of the mil-1 gene is controlled by germ-cell conserved regulatory sequences in the 5' flanking region. Once they have undergone specification and differentiation, PGCs normally give rise to gametes, but they maintain the potential to be converted into pluripotential stem cells upon activation of particular signaling pathways.

We report what is to our knowledge the first demonstration of terahertz-rate optical pulse generation by harmonic passive mode locking in a distributed-Bragg-reflector laser diode. Along with the fundamental repetition rate of 38.8 GHz, we observed 400-GHz, 800-GHz, and 1.54-THz harmonics, depending on the bias condition of gain section. The pulse envelope for 1.54-THz pulses was in good agreement with a calculation from the Fourier transformation of the optical spectrum, indicating that the output pulses are transform limited.

As a pretreatment for membrane microfiltration (MF), the use of powdered activated carbon (PAC) with a particle size much smaller than that of conventional PAC (super-powdered PAC, or S-PAC) has been proposed to enhance the removal of dissolved substances. In this paper, another advantage of S-PAC as a pretreatment for MF is described: the use of S-PAC attenuates trans-membrane pressure increases during the filtration operation. The floc particles that formed during coagulation preceded by S-PAC pretreatment were larger and more porous than the floc particles formed during coagulation preceded by PAC pretreatment and those formed during coagulation without pretreatment. This result was due to increased particle-particle collision frequency and better removal of natural organic matter, which inhibits coagulation by consuming coagulant, before the coagulation reaction. The caked fouling layer that built up on the membrane surface was thus more permeable with S-PAC than with normal PAC. Both physically reversible and irreversible membrane foulings were reduced, and more stable filtration was accomplished with S-PAC pretreatment.

Two case-control studies were designed to investigate the contribution of the geometry and bone mineral density (BMD) of the proximal femur to bone strength in Japanese elderly women. We also investigated whether clinical CT is useful to assess the risk of hip fracture. Subjects in the neck fracture study included 20 Japanese women with neck fracture (age: mean+/-SD; 80.1+/-4.5 years old) and 20 age-matched control women (79.2+/-2.6 years old). Subjects in the trochanteric fracture study included 16 Japanese women with trochanteric fracture (82.6+/-5.0 years old) and 16 age-matched control women (80.8+/-3.8 years old). CT examination of the proximal femur was performed between the date of admission and the date of surgery. The CT scanners used were an Aquillion 16 (Toshiba) and Somatom 16 (Siemens); the scanning conditions including spatial resolution and scanning energy were adjusted, and the same type of reference phantom containing hydroxyapatite was used. QCT PRO software (Mindways, USA) was used to analyze data for BMD, geometry, and biomechanical parameters. Both the neck and trochanteric fracture cases had significantly lower total and cortical BMD, a significantly smaller cortical cross-sectional area (CSA) and a larger trabecular CSA. Both had significantly thinner cortex and smaller distance to center of bone mass, and women with trochanteric fracture had a significantly smaller cortical perimeter in the cross-sectional femoral neck. Women with neck fracture had a longer hip axis length (HAL) and women with trochanteric fracture had a significantly larger neck-shaft angle (NSA). Both groups had significantly lower cross-sectional moment of inertia (CSMI), and only women with neck fracture had a significantly higher buckling ratio (BR) compared to their respective controls. According to the multiple logistic regression analysis, women with neck fracture had a significantly longer HAL, lower CSMI, and higher BR, and women with trochanteric fracture had a significantly smaller cortical CSA of the femoral neck. We conclude that clinical CT may be useful for the assessment of the risk of neck and trochanteric fracture.

Primordial germ cells (PGCs) are undifferentiated germ cells in embryos. We previously found that some mouse PGCs develop into pluripotential cells (EG cells) when cultured on a feeder layer expressing the membrane bound form of Steel factor with culture medium containing leukemia inhibitory factor and basic fibroblast growth factor. To understand the mechanisms of the conversion of PGCs into EG cells, we attempted to identify PGC subpopulations that have the ability to develop into EG cells. Using flow cytometry, we fractionated PGCs by the expression of the cell surface antigen integrin alpha6, as well as by the detection of side-population (SP) cells in which stem cells are enriched in various tissues. PGCs with negative or low integrin alpha6 expression and with SP cell phenotype showed higher potential to convert to EG cells. Negative or low integrin alpha6 expression in PGCs was also correlated with lower expression of Ddx4, which is specifically expressed in PGCs after embryonic day 10.5. The results indicate that the primitive PGC population showing the SP cell phenotype among undifferentiated PGCs has a higher ability of being converted into EG cells. Thus, conversion of PGCs into pluripotential stem cells may be regulated by being influenced by the natural status of individual PGCs as well as the reprogramming process after starting culture.

The signature of correlated electron materials (CEMs) is the coupling between spin, charge, orbital and lattice resulting in exotic functionality. This complexity is directly responsible for their tunability. We demonstrate here that the broken symmetry, through cubic to orthorhombic distortion in the lattice structure in a prototype manganite single crystal, La(0.69)Ca(0.31)MnO(3), leads to an anisotropic magneto-elastic response to an external field, and consequently to remarkable magneto-transport behavior. An anomalous anisotropic magnetoresistance (AMR) effect occurs close to the metal-insulator transition (MIT) in the system, showing a direct correlation with the anisotropic field-tuned MIT in the system and can be understood by means of a simple phenomenological model. A small crystalline anisotropy stimulates a "colossal" AMR near the MIT phase boundary of the system, thus revealing the intimate interplay between magneto- and electronic-crystalline couplings.