Differentiation of population of peripheral blood lymphocytes into cells bearing sheep erythrocyte receptors in vitro by human thymic extract.

A small population of human marrow cells has been shown to be differentiated in vitro by thymic extract into cells bearing T-lymphocyte (thymus-derived lymphocyte) characteristics. By a similar method, the differentiation of human peripheral blood lymphocytes has been studied. A discontinuous gradient of bovine serum albumin was used to isolate lymphocytes into four layers and cells from layers I and III demonstrated the greatest potential for differentiation by human thymic extract. Appearance of T-lymphocyte characteristics was recognized by the spontaneous E-rosette technique with sheep erythrocytes. Ability of human marrow cells to be differentiated under the influence of human thymic extract was abolished by specific inhibitors of nucleic acid synthesis, however, had no inhibitory effect on the maturation of peripheral blood lymphocytes during a 2 hr incubation with human thymic extract but puromycin, an inhibitor of protein synthesis, abolished this differentiative step in cells of layer I. It is suggested from these studies that many of the cells in peripheral blood that are differentiable by thymic extract are at a stage of maturation more advanced than those in human marrow that are also differentiable by thymic extract.     

Correction: Self-assembled fibrillar networks comprised of a naturally-occurring cyclic peptide—LOB3

Correction for ‘Self-assembled fibrillar networks comprised of a naturally-occurring cyclic peptide—LOB3’ by M. A. Rogers et al., RSC Adv., 2016, 6, 40765–40776.

The authors regret the omission of the following conflict of interest statement.Dr Martin J. T. Reaney is the founder of, and has an equity interest in, Prairie Tide Diversified Inc. (PTD, Saskatoon, SK, Canada: previous company name is Prairie Tide Chemicals Inc.). Dr Youn Young Shim is a Market Consultant for PTD in Korea. The terms of this arrangement have been reviewed and approved by the University of Saskatchewan in accordance with its conflict of interest policies.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Targeted deletion of the GluR-1 AMPA receptor in mice dissociates general and outcome-specific influences of appetitive rewards on learning

The authors assessed the hypothesis that deletion of the GluR-1 subtype of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor in mice disrupts the associative activation of a sensory-specific representation of an appetitive reward. In Experiment 1, mice received training on a Pavlovian-instrumental transfer task. In the test stage, conditioned stimulus (CS) presentations enhanced instrumental actions in both groups. However, this effect was specific to the action that shared the same outcome as the CS in wild-type (WT), but not GluR-1-super(-/-), mice. In Experiment 2, the mice were trained on a heterogeneous instrumental chain in which rewards were obtained for emitting 1 response (R1, that was distal to reward delivery), followed by a 2nd response (R2, that was proximal to reward delivery). A change in general motivational state (from hungry to sated) reduced the number of R2 responses in both groups. In contrast, an outcome-specific satiety treatment produced a selective decline in R1 responding only in WT mice. The results support the hypothesis that GluR-1 deletion impairs the associative activation of a representation of the sensory-specific incentive motivational properties of an appetitive reward.     

Impaired "episodic-like" object memory in adult APPswe transgenic mice

An early clinical symptom of Alzheimer's disease is impaired episodic memory. However, the precise pathological event(s) that underpins this deficit remains unclear. In the present study, the authors examined whether wild-type mice and Tg2576 mice expressing an amyloid precursor protein (APP) mutation are able to form an integrated memory of the spatio-temporal context in which objects are presented. In Experiment 1, wild-type mice, but not Tg2576 mice that were 10-12 months old, explored objects presented in a novel location. In Experiment 2, wild-type mice explored an object that was presented both earlier in a sequence and in a different location relative to other objects that possessed only one of these properties (i.e., memory for "what," "where," and "when" items were presented). In contrast, the behavior of adult Tg2576 mice was influenced only by the temporal order in which objects were presented. These results demonstrate that wild-type, but not APP-mutant, mice are able to form an "episodic-like" memory of the spatio-temporal properties of objects and support the hypothesis that aberrant APP processing contributes to impairments in event memory.     

Analysis of the pentafecta learning curve for laparoscopic radical prostatectomy

Purpose

Laparoscopic radical prostatectomy (LRP) has a long learning curve; however, little is known about the pentafecta learning curve for LRP. We analysed the learning curve for a fellowship trained surgeon with regard to the pentafecta with up to 6-year follow-up.

Methods

A retrospective review was performed in 550 cases, by dividing these cases into 11 groups of 50 patients. Outcomes analysed were the following: (1) the pentafecta (complication rate, positive surgical margin (PSM) rate, continence, potency and biochemical recurrence); (2) operative time and blood loss; and (3) overall pentafecta attainment.

Results

The mean complication rate for the entire series was 9 %; this plateaued after 150 cases. The overall PSM rate for the series was 23.5 %, 16.3 % for pT2 and 40.5 % for pT3. PSM plateaued after 200 cases. Excluding the first 100 cases, the overall PSM rate for pT2 was 10.9 % and 37.8 % for pT3. The continence rate stabilised after approximately 250 cases. The rate of male sling/artificial urinary sphincter plateaued after 200 cases. The potency learning curve continues to improve after 250 cases of nerve-sparing (ns) endoscopic extraperitoneal radical prostatectomy (EERPE) as does the pentafecta learning curve which closely follows the pattern of the potency learning curve. The last group of nsEERPE achieved pentafecta in 63 %.

Conclusion

This study shows multiple learning curves: an initial for peri-operative outcomes, then stabilisation of oncologic outcomes and the final for stabilisation of functional outcomes. In this series over 250 cases were required to achieve the learning curve.