Inhibition of NADPH oxidase 4 activates apoptosis via the AKT/apoptosis signal-regulating kinase 1 pathway in pancreatic cancer PANC-1 cells.

Pancreatic adenocarcinoma is an aggressive human malignancy and is characterized by resistance to apoptosis. Recently, NADPH oxidase (Nox) 4-mediated generation of intracellular reactive oxygen species (ROS) was proposed to confer antiapoptotic activity and thus a growth advantage to pancreatic cancer cells. The signaling mechanism by which Nox4 transmits cell survival signals remains unclear. Here, we show that both a flavoprotein inhibitor, diphenylene iodonium (DPI), and small interfering RNAs designed to target Nox4 mRNA (siNox4RNAs) inhibited superoxide production in PANC-1 pancreatic cancer cells, and depletion of ROS by DPI or siNox4RNAs induced apoptosis. Parallely, DPI treatment and siNox4RNA transfection blocked activation of the cell survival kinase AKT by attenuating phosphorylation of AKT. Furthermore, AKT phosphorylation of apoptosis signal-regulating kinase 1 (ASK1) on Ser-83 was reduced by DPI and siNox4RNAs. When ASK1Ser83Ala (an AKT phosphorylation-defective ASK1 mutant) was introduced into PANC-1 cells, this mutant alone induced apoptosis. But, addition of DPI or co-transfection of siNox4RNA had no additive effect, indicating that the mutant can substitute for these reagents in apoptosis induction. Taken together, these findings suggest that ROS generated by Nox4, at least in part, transmit cell survival signals through the AKT-ASK1 pathway in pancreatic cancer cells and their depletion leads to apoptosis.

Problems of long-term hospitalised cervical spinal cord injury patients in university hospitals.

Of the 215 cervical spinal cord injury (CSCI) patients treated in Tokai University Hospital over the last 17 years, 42 who were hospitalised for more than 90 days were selected as the subjects for this survey. They were divided into two groups: group A: patients hospitalised for 180 days or more; and group B: patients hospitalised for more than 90 but less than 180 days. The aspects surveyed were: the number of days of hospitalisation, type of injury, level of spinal cord injury, extent of spinal cord paralysis, assessment based on Frankel's classifications, whether a tracheotomy was performed or not, surgical treatment, complications, and the clinical course after discharge. The most common injury for the 13 patients in group A (average stay 281 days) was a fracture-dislocation, followed next by those with a burst fracture. The majority of the 28 patients in group B (average stay was 117 days) had a central type of spinal cord injury. Characteristics observed in group A in particular were: higher segment injuries to the cervical spinal cord, complete paralysis, respiratory complications such as pneumonia, tracheotomy, or a waiting time of at least 6 months before discharge, in cases where a transfer to a rehabilitation hospital was possible. The major problems of treating CSCI patients in university hospitals are that severe cases, which are concentrated in university hospitals, are forced to occupy private rooms for long term treatment, and there is a difficulty in transferring these patients to rehabilitation hospitals.(ABSTRACT TRUNCATED AT 250 WORDS)

Release and crystallization of berberine in the liquid medium of Thalictrum minus cell suspension cultures.

Cell suspension cultures of Thalictrum minus L. var. hypoleucum Miq. were found to produce a large amount of berberine (400-800 mg/l) when 5-10 µM 6-benzyladenine was added to Linsmaier and Skoog's medium containing 100 µM 1-naphthaleneacetic acid. Most of the berberine produced was released continuously from the cells into the liquid medium, and an excess of berberine crystallized as its nitrate in the medium. When the cells were cultured in a modified LS medium containing 20 mM KNO3 and 40 mM NH4Cl in place of 20.6 mM NH4NO3 as nitrogen source, most of the alkaloid crystallized to form berberine chloride instead of nitrate. Minor alkaloids, thalifendine and magnoflorine, were also isolated from the medium and identified.