Timing and expression pattern of carbonic anhydrase II in pancreas.

In the search for genetic markers for assessing the role of duct cells in pancreas growth, we examined whether carbonic anhydrase II (CAII) has ductal cell specificity. We determined the distribution and timing of CAII expression in mouse pancreas from embryonic stage to adult. The pancreatic ducts only start expressing CAII at embryonic day (E) 18.5, with increases after birth. Around E15.5, glucagon-positive cells, but not insulin-positive cells, also express CAII, with further increases by adult. CAII expression was restricted to cells within ductal structures and glucagon-positive cells with no colocalization with any insulin-positive cells at any time. In the human pancreas, CAII expression is restricted to the ducts. Furthermore, the activity of a 1.6-kb fragment of the human promoter with Luciferase assays was moderately strong compared with the cytomegalovirus promoter in human pancreatic duct cell line (PANC-1). Thus, we believe that the CAII gene could serve as a useful pancreatic duct cell marker.     

MHC-I expression in HTLV-1-positive and -negative cells

The expression level of major histocompatibility class I (MHC-I) and the extent of down-regulation of MHC-I after an anti-MHC-I antibody treatment in numerous human T-cell leukemia virus type 1 (HTLV-1)-positive and -negative lymphocytic cell lines were examined. While there was no clear correlation between the expression level of MHC-I and the presence of HTLV-1 genome, a relatively low level of MHC-I down-regulation was generally induced in HTLV-1-positive cells by the antibody. The results may suggest the potential involvement of MHC-I in HTLV-1 leukemogenesis.     

Isolation and characterization of a highly divergent HIV-2[GH-2]: generation of an infectious molecular clone and functional analysis of its rev-responsive element in response to primate retrovirus transactivators (Rev and Rex).

A highly divergent HIV-2 designated as HIV-2[GH-2] was obtained from an AIDS-related complex (ARC) patient in Ghana. A full-length molecular clone of this isolate was obtained and a biologically active clone was constructed. Its restriction pattern differed from that of prototype HIV-2[GH-1] in 25 of 35 restriction sites, but was strikingly similar to a previously characterized HIV-2 isolate from a Ghanaian (HIV-2ALT). The conserved integrase region (288-bp fragment) previously displayed 95% identity with that of ALT but 17-20% divergence from the HIV-2 prototype member, and a new distinct subgroup (HIV-2b) of HIV-2 consisting of GH-2 and ALT was postulated (Miura et al. 1991.) These isolates, however, were biologically distinguishable from each other by its replication capacity in a monocyte line, U937, in which GH-2 could not grow but ALT grew well. In addition, the nucleotide sequence of the LTR of this new isolate displays 21% divergence from that of prototype HIV-2[GH-1], but the core enhancer, Sp1 binding sites and TATA box were conserved. Although the 3' half of the env gene sequence which is deleted in HIV-2ALT clone showed 27% diversity from the prototype, functional differences in the rev-responsive element were not observed.     

The pancreatic ductal epithelium serves as a potential pool of progenitor cells

Abstract:  With the increasing success of islet transplantation, β-cell replacement therapy has had renewed interest. To make such a therapy available to more than a few of the thousands of patients with diabetes, new sources of insulin-producing cells must become readily available. The most promising sources are stem cells, whether embryonic or adult stem cells. Clearly identifiable adult pancreatic stem cells have yet to be characterized. Although considerable evidence suggests their possibility, recent lineage-tracing experiments challenge their existence. Even in light of these lineage-tracing experiments, we suggest that evidence for neogenesis or new islet formation after birth remains strong. Our work has suggested that the pancreatic duct epithelium itself serves as a pool for progenitors for both islet and acinar tissues after birth and into adulthood and, thus, that the duct epithelium can be considered 'facultative stem cells'. We will develop our case for this hypothesis in this perspective.     

A new protocol for the preparation of superconducting KBi2

A superconducting KBi₂ sample was successfully prepared using a liquid ammonia (NH₃) technique. The temperature dependence of the magnetic susceptibility (M/H) showed a superconducting transition temperature (T_c) as high as 3.6 K. In addition, the shielding fraction at 2.0 K was evaluated to be 87%, i.e., a bulk superconductor was realized using the above method. The T_c value was the same as that reported for the KBi₂ sample prepared using a high-temperature annealing method. An X-ray diffraction pattern measured based on the synchrotron X-ray radiation was analyzed using the Rietveld method, with a lattice constant, a, of 9.5010(1) Å under the space group of Fd$\bar{3}$m (face-centered cubic, no. 227). The lattice constant and space group found for the KBi₂ sample using a liquid NH₃ technique were the same as those reported for KBi₂ through a high-temperature annealing method. Thus, the superconducting behavior and crystal structure of the KBi₂ sample obtained in this study are almost the same as those for the KBi₂ sample reported previously. Strictly speaking, the magnetic behavior of the superconductivity was different from that of a KBi₂ sample reported previously, i.e., the KBi₂ sample prepared using a liquid NH₃ technique was a type-II like superconductor, contrary to that prepared using a high-temperature annealing method, the reason for which is fully discussed. These results indicate that the liquid NH₃ technique is effective and simple for the preparation of a superconducting KBi₂. In addition, the topological nature of the superconductivity for KBi₂ was not confirmed.

A superconducting KBi₂ sample was successfully prepared using a liquid ammonia (NH₃) technique.     

Safety of peritoneal dialysis catheter surgery under dexmedetomidine and local anesthesia for elderly patients in Japan: a single-center prospective cohort study

Clinical and Experimental Nephrology - The number of patients aged ≥ 75 years and who need renal replacement therapy is steadily increasing. The study aimed to determine...     

Impact of preoperative factors on catheter position in peritoneal dialysis: a prospective cohort study

Clinical and Experimental Nephrology - Peritoneal dialysis (PD) catheter malposition is one of the complications of renal replacement therapy. This study aimed to determine the preoperative factors...