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.     

Identification of a second T-cell antigen receptor in human and mouse by an anti-peptide gamma-chain-specific monoclonal antibody.

We developed a monoclonal antibody (mAb) (9D7) against a synthetic peptide (P13K) selected from the deduced amino acid sequence of the constant region of the gamma chain of the murine T-cell antigen receptor (TCR) (amino acids 118-130). Using this mAb, we identified a putative second TCR expressed on peripheral blood lymphocytes from a patient with severe combined immunodeficiency (SCID) that were propagated in culture with recombinant interleukin 2 (rIL-2) and Con A. This mAb immunoprecipitated two polypeptide chains of 40 and 58 kDa under nonreducing conditions and of 40 and 56 kDa under reducing conditions from 125I-labeled denatured lysates of T3+ WT31- lymphocytes expanded in culture from a SCID patient. These polypeptide chains were not disulfide linked and were not present on human peripheral blood lymphocytes from normal donors cultured for 5 days with phytohemagglutinin or for 2 weeks with rIL-2 and polyclonal activators or on cells of the Jurkat lymphoblastoid human T-cell line. Chemical crosslinking of 125I-labeled cells followed by immunoprecipitation with anti-Leu-4 mAb under nonreducing or reducing conditions revealed that the 40- and 56-kDa polypeptide chains were associated with the T3 differentiation antigen. These results were confirmed by sequential immunoprecipitation with anti-Leu-4 mAb followed by 9D7 anti-P13K mAb. The 9D7 anti-P13K mAb immunoprecipitated two polypeptide chains of 43 and 64 kDa from denatured lysates of lymphocytes from a patient with severe common variable immunodeficiency (CVI) that were expanded in culture with rIL-2 and Con A. Thus, this second TCR may be composed of two polypeptide chains (gamma gamma'), both of which appear to be the product of the gamma-chain gene. These experiments were done with polyclonal cell populations. Cloned T3+ WT31- cell populations are required to determine whether this TCR contains two gamma polypeptide chains. In contrast, only one polypeptide chain of 56 kDa was immunoprecipitated by the 9D7 anti-P13K mAb from peripheral blood lymphocytes from a patient with mild CVI expanded in culture with rIL-2 and polyclonal activators. Using the same 9D7 anti-P13K mAb and immunoblotting analysis, we identified a 35 kDa gamma-chain polypeptide under reducing conditions expressed on purified L3T4- Lyt2- BALB/c mouse thymocytes. This gamma-chain TCR is disulfide linked and has a molecular mass of 80 kDa under nonreducing conditions.     

Functional T cells in athymic nude mice.

After passage of spleen cells from nu/nu mice over a nylon wool column, concanavalin A-responsive cells can be detected in the presence of 2-mercaptoethanol, and specific cytotoxic T lymphocytes can be generated without exposure to interleukin 2 (IL-2). The spleen cells of the nu/nu mice born of nu/nu parents and nursed by nu/nu mothers had significantly fewer Thy-1+ T cells and a lesser capacity to generate cytotoxic T lymphocytes than did the conventionally bred nu/nu mice. Nonetheless, such cells were clearly present. IL-2 may act to cause these post-thymic T cells to proliferate. Therefore, it seems inappropriate to consider IL-2 as an inducer of the differentiation of T cells in the absence of thymic influence on the basis of the capacity of IL-2 to induce the appearance of a T-lymphocyte population in nu/nu mice.     

Selective growth of a population of human basophil cells in vitro.

An initially homogeneous population of basophilic polymorphonuclear leukocytes was derived from human fetal liver cells grown in culture for 5-7 days. The cells were characterized as basophils by their morphology, histologic staining characteristics, and histamine content, and by the presence of IgE receptors on their surface. In this culture system the basophils were viable for up to 10 days.