Patterns of outgrowth of regenerating axons through spinal cord lesion

We found that bone marrow stromal cells (BMSCs) do not survive for long enough to serve as a scaffold for regenerating axons after transplantation in the injured spinal cord of rats. However, axonal regeneration was facilitated, possibly by trophic factors secreted from transplanted BMSCs. Regenerating axons were not associated with astrocytes, but surrounded by Schwann cells (SCs), and embedded in collagen fibril matrices just as the axons of peripheral nerves. Experiments involving the transplantation of SCs themselves indicated that, besides exogenous SCs, intrinsic SCs infiltrated the lesion and formed myelin sheaths on regenerating axons in the same manner as described with BMSC transplantation. The transplantation of olfactory ensheathing cells (OECs) showed that OECs themselves enclosed regenerating axons in the same manner as SCs. No study has been carried out to address whether such Schwann-like cells were derived from transplanted OECs or intrinsic SCs. However, the possibility cannot be excluded that intrinsic SCs contributed to surround regenerating axons. Neural stem cells (NSCs) derived from iPS cells survived long-term, emanating numerous axons that extended over a long distance through the host spinal cord tissue. However, no myelination occurred on regenerating axons, and no behavioral improvement was observed. It would be difficult to manipulate iPS-derived NSCs to appropriately integrate them into the host spinal cord tissue. In this respect, iPS cells have crucial problems concerning whether they can be integrated appropriately into the host tissue. Muse cells (multilineage-differentiating stress-enduring cells) were separated as SSEA3-positive cells from BMSCs. Transplanted Muse cells survived long-term, but they were not as effective as non-Muse cells or BMSCs for the treatment of infarcted brains, suggesting that trophic factors from non-Muse cells and BMSCs are involved in those effects. These findings indicate that intrinsic SCs and trophic factors released from transplants may play important roles in nerve regeneration of the spinal cord. Differing from the generally believed pattern of regeneration, glial cells are not necessarily needed as the scaffolds for growing axons in the spinal cord

Analysis of multidrug-resistant Pseudomonas aeruginosa in a hospital with a dominant population of geriatric inpatients

Bacterial resistance and opportunistic human pathogens have become serious problems in hospitals, particularly those in which the dominant population consists of immunocompromised elderly inpatients. Pseudomonas aeruginosa is a prevalent opportunistic human pathogen that causes acute pneumonia, cystic fibrosis, and septicemia, and it is also known to possess various mechanisms of natural and acquired resistance to antibiotics. Carbapenems have been used to treat infections caused by β-lactamase-producing gramnegative bacteria including P. aeruginosa, but metallo-β-lactamase (MBL) can render carbapenems ineffective, and so action is required to prevent the development of strains that produce MBL. Between September 2010 and August 2011, 8 multidrug-resistant P. aeruginosa (MDRP) strains were isolated from pressure ulcer, urine, or expectoration or aspiration sputum samples of patients with different infections in a hospital in Osaka Prefecture, Japan. After confirming MBL production, we identified 5 strains that produced IMP-type MBL. The strain variations of isolated MDRP were determined by multiplelocus variable-number tandem repeat analysis. Because the 5 IMP-type MBL-producing strains were of the same genotype, it was suggested that the infection had spread within the wards. The remaining non-MBL-producing MDRP strains were also of the same genotype, but antimicrobial breakpoint tests revealed that they were not exactly the same, and the wards from which they had been isolated were not close to each other. Therefore, more accurate typing of the non-MBL-producing genotype group is required to determine whether diffusion between the wards had occurred

Behavior, cognition, and future direction of psychiatry

The human behavior and cognition are the two most important functions for human life in the society. The cognitive function is declined in the elderly, but it is not always the case. Fluid intelligence may decline along with aging but crystalized intelligence can be maintained even in the elderly. In addition to neurocognitive disorders (dementia), cognitive function is impaired with various psychiatric disorders and it will be the main target for future psychiatry. Due to the knowledge obtained from the recent development in brain mapping, psychiatrists can perceive and understand the meaning of the psychiatric symptoms based upon the dysfunction of these networks. Subjective experience of the patients should be paid more attention by closer collaboration between psychiatrists/ researchers and patients/ families. Elucidating the brain network representing common sense will be important. Psychiatrists are recommended to expand the range of the frame of their common sense to be able to understand the meaning of the patient behavior

Cell transplantation studies on the treatment of spinal cord injury using clinically relevant cells

Many different kinds of cells have been studied for transplantation in experimental animals including rats with spinal cord injury. This short review focused on adult somatic and umbilical cord cells to be used for therapy of spinal cord injury. Adult somatic cells have no inherent ethical problems in using for clinical application. Embryonic stem (ES) cells, neural stem cells, and induced pluripotent stem (iPS) cells were excluded. Bone marrow stromal cells and olfactory ensheathing cells have already been used clinically for transplantation to patients with spinal cord injury. Other cells dealt with in this review include dental pulp-derived, skin-derived, adipose-derived, and umbilical cord-derived stem cells. Muse cells, and choroid plexus epithelial cells

Characterization of Acinetobacter clinical isolates

Members of the genus Acinetobacter are typical opportunistic bacterial pathogens that can survive for a long term even on inanimate surfaces. Acinetobacter species have natural and acquired antibiotic resistance mechanisms that provide resistance against a broad range of antimicrobial agents. Between April 2010 and March 2011, 6 clinical Acinetobacter sp. strains were isolated from expectoration or aspiration sputum samples in a local medical treatment-type hospital in Osaka prefecture. The antibiotic susceptibility breakpoint test showed that all the 6 isolates were ciprofloxacin-resistant. Strain AHU-70, which was identified as A.baumannii by 16S rRNA sequencing and polymerase chain reaction detection of the blaOXA-51-like gene, showed high levels of resistance to ciprofloxacin by the minimum inhibitory concentration (MIC) test. Preliminary research in Japan, based on nationwide susceptibility surveillance of ciprofloxacin against A.baumannii isolates showed that approximately 90% of the isolates were ciprofloxacin-susceptible. Given these results, further strain level identification of isolates is required to determine whether resistance to ciprofloxacin is an overall trait of these bacteria in the sampled local area or is restricted to a specific strain within particular hospitals