Suggestion For a New Classification of Postoperative Neurological Complications (CPNC) in Neurosurgery

To design a classification concentrating on the art and severity of functional restriction that could include all possible postoperative neurological disturbances and prove its validity to be comparable and easily used in neurosurgery. A seven grade classification was proposed commencing from grade "0" for no neurological disturbances to grade "6" for coma/vegetative state/demise: grade “1”, any remittent neurological disturbances with full improvement spontaneously or as a result of any temporary drug therapy or re-surgery, a single epileptic seizure without the need for anticonvulsant therapy; grade “2”, lasting neurological disturbances resulting in no functional restrictions, no epileptic seizures needing for long-term anticonvulsant therapy; grade “3”, lasting neurological disturbances resulting in slight functional restrictions, rare epileptic seizures despite of anticonvulsant therapy, slight aphasia; grade “4”, lasting neurological disturbances resulting in moderate functional restrictions and partial need of outside help, average frequency of epileptic seizures despite anticonvulsant therapy, moderate aphasia; and grade “5”, lasting neurological disturbances resulting in severe functional restriction and complete need of outside help, high frequency of epileptic seizures despite of anticonvulsant therapy, severe aphasia. The study included a total of 1681 operations at 1530 patients. The postoperative neurological disturbances occurred in 7.7% (n=119) of patients. All postoperative neurological disturbances could be easily classified according to the CPNC. The ranking system was proportional to the length of hospital stay. The CPNC is useful and easily applicable to assess the rates of postoperative neurological disturbances. It can be a comparable instrument in the quality management of neurosurgery.

Bacteria from natural populations transfer plasmids mostly towards their kin

Plasmids play a key role in microbial ecology and evolution, yet the determinants of plasmid transfer rates are poorly understood. Particularly, interactions between donor hosts and potential recipients are understudied. Here, we investigate the importance of genetic similarity between naturally co-occurring Escherichia coli isolates in plasmid transfer. We uncover extensive variability, spanning over five orders of magnitude, in the ability of isolates to donate and receive two different plasmids, R1 and RP4. Overall, transfer is strongly biased towards clone-mates, but not correlated to genetic distance when donors and recipients are not clone-mates. Transfer is limited by the presence of a functional restriction-modification system in recipients, suggesting sharing of strain-specific defence systems contributes to bias towards kin. Such restriction of transfer to kin sets the stage for longer-term coevolutionary interactions leading to mutualism between plasmids and bacterial hosts in natural communities.

Plasmid transfer is biased towards close kin in bacteria from natural populations

Plasmids play a key role in microbial ecology and evolution, yet the determinants of plasmid transfer rates are poorly understood. Here we investigate the importance of genetic similarity between naturally co-occurringEscherichia coliisolates in the transfer of two plasmids (narrow-host-range R1 and broad-host-range RP4). We uncovered extensive variability, spanning over five orders of magnitude, in the ability of isolates to donate and receive plasmids. Overall, transfer was strongly biased towards clone-mates, but not correlated to genetic distance between donors and recipients. Transfer was limited by the presence of a functional restriction-modification system in recipients, thus bias towards kin might be explained by sharing of identical restriction systems. Such conjugation within lineages sets the stage for longer-term pair-wise coevolutionary interactions between plasmids and bacterial hosts.

Design and Evaluation of a Wearable Powered Foot Orthosis with Metatarsophalangeal Joint

The metatarsophalangeal (MTP) joints play critical roles in human locomotion. Functional restriction or loss of MTP joints will lead to lower walking speed, poorer walking balance, and more consumed metabolic energy cost compared with normal walking. However, existing foot orthoses are focused on maintaining the movement of the ankle joint, without assisting the MTP joints. In this paper, in order to improve the walking performance of people with lower limb impairments, a wearable powered foot orthosis (WPFO) which has actuated MTP joint is designed and constructed. Preliminary experiments on three nondisabled subjects demonstrated functionality and capabilities of the WPFO to provide correctly timed dorsiflexion and plantar flexion assistance at the MTP joint during walking. These results also suggest that the WPFO could offer promise in certain rehabilitation applications and clinical treatment.

Lgr5+ intestinal stem cells reside in an unlicensed G1 phase

During late mitosis and the early G1 phase, the origins of replication are licensed by binding to double hexamers of MCM2–7. In this study, we investigated how licensing and proliferative commitment are coupled in the epithelium of the small intestine. We developed a method for identifying cells in intact tissue containing DNA-bound MCM2–7. Interphase cells above the transit-amplifying compartment had no DNA-bound MCM2–7, but still expressed the MCM2–7 protein, suggesting that licensing is inhibited immediately upon differentiation. Strikingly, we found most proliferative Lgr5+ stem cells are in an unlicensed state. This suggests that the elongated cell–cycle of intestinal stem cells is caused by an increased G1 length, characterized by dormant periods with unlicensed origins. Significantly, the unlicensed state is lost in Apc-mutant epithelium, which lacks a functional restriction point, causing licensing immediately upon G1 entry. We propose that the unlicensed G1 phase of intestinal stem cells creates a temporal window when proliferative fate decisions can be made.

Delayed activation of the DNA replication licensing system in Lgr5(+) intestinal stem cells

ABSTRACTDuring late mitosis and early G1, replication origins are licensed for replication by binding to double hexamers of MCM2-7. Here, we investigate how licensing and proliferative commitment are coupled in the small-intestinal epithelium. We developed a method for identifying cells in intact tissue containing DNA-bound MCM2-7. Interphase cells above the transit-amplifying compartment had no DNA-bound MCM2-7, but still expressed MCM2-7 protein, suggesting that licensing is inhibited immediately upon differentiation. Strikingly, we found most proliferative Lgr5(+) stem cells are in an unlicensed state. This suggests that the elongated cell-cycle of intestinal stem-cells is caused by an increased G1 length, characterised by dormant periods with unlicensed origins. Significantly, the unlicensed state is lost In Apc mutant epithelium, which lacks a functional restriction point, causing licensing immediately upon G1 entry. We propose that the unlicensed G1 of intestinal stem cells creates a temporal window when proliferative fate decisions can be made.