Peptidoglycan maturation controls outer membrane protein assembly.

Linkages between the outer membrane of Gram-negative bacteria and the peptidoglycan layer are crucial for the maintenance of cellular integrity and enable survival in challenging environments1-5. The function of the outer membrane is dependent on outer membrane proteins (OMPs), which are inserted into the membrane by the ß-barrel assembly machine6,7 (BAM). Growing Escherichia coli cells segregate old OMPs towards the poles by a process known as binary partitioning, the basis of which is unknown8. Here we demonstrate that peptidoglycan underpins the spatiotemporal organization of OMPs. Mature, tetrapeptide-rich peptidoglycan binds to BAM components and suppresses OMP foldase activity. Nascent peptidoglycan, which is enriched in pentapeptides and concentrated at septa9, associates with BAM poorly and has little effect on its activity, leading to preferential insertion of OMPs at division sites. The synchronization of OMP biogenesis with cell wall growth results in the binary partitioning of OMPs as cells divide. Our study reveals that Gram-negative bacteria coordinate the assembly of two major cell envelope layers by rendering OMP biogenesis responsive to peptidoglycan maturation, a potential vulnerability that could be exploited in future antibiotic design.

Including formal and informal caregivers in the development of Play Intervention for Dementia: a qualitative study.

BACKGROUND: Play Intervention for Dementia is a practice initiative using play to help people living with dementia (PWD) experience engagements, autonomy, and cognitive stimulation. This program was developed under a participatory paradigm, with extensive contribution from formal and informal caregivers. This article describes how caregivers contributed to the practice principles, materials, and assessment during the development phase of Play Intervention for Dementia through community-based participatory research (CBPR). METHODS: Three service supervisors, 16 formal caregivers and 14 informal caregivers from the community participated in this study. Based on CBPR, the study progressed in a reflexive, iterative and collaborative way. Data were collected from diverse sources, including practice journals, observation notes and reflexive focus group interviews. Two trained qualitative researchers conducted thematic analysis on the data collected, with focus on practical skills, outcomes, and caregivers' general experience during the intervention. RESULTS: The therapeutic and liberating power of play was thoroughly discussed by the caregivers. They considered play as an innovative way to understand, engage, and connect with the PWD. Also, improvement in energy level, motivation and communicative capacity was observed among the PWD. The researcher and caregivers collaboratively refined and designed the protocol of Play Intervention for Dementia, adding localized principles and games to the original design. CONCLUSION: Caregivers found play to be a meaningful way to engage with PWD, as it provided an equal platform for them. The intervention also enabled them to reflect upon ageing and disease at a deeper level. Caregivers have contributed significantly to the refinement and contextualisation of the intervention. The efficiency of the refined program should be further tested on a larger scale.

Outcomes of anterior lumbar interbody fusion surgery based on indication: a prospective study.

BACKGROUND: There is limited information on clinical outcomes after anterior lumbar interbody fusion (ALIF) based on the indications for surgery. OBJECTIVE: To compare the clinical and radiological outcomes of ALIF for each surgical indication. METHODS: This prospective clinical study included 125 patients who underwent ALIF over a 2-year period. The patients were evaluated preoperatively and postoperatively. Outcome measures included the Short Form-12, Oswestry Disability Index, Visual Analog Scale, and Patient Satisfaction Index. RESULTS: After a mean follow-up of 20 months, the clinical condition of the patients was significantly better than their preoperative status across all indications. A total of 108 patients had a Patient Satisfaction Index score of 1 or 2, indicating a successful clinical outcome in 86%. Patients with degenerative disk disease (with and without radiculopathy), spondylolisthesis, and scoliosis had the best clinical response to ALIF, with statistically significant improvement in the Short Form-12, Oswestry Disability Index, and Visual Analog Scale. Failed posterior fusion and adjacent segment disease showed statistically significant improvement in all of these clinical outcome scores, although the mean changes in the Short Form-12 Mental Component Summary, Oswestry Disability Index, and Visual Analog Scale (back pain) were lower. The overall radiological fusion rate was 94.4%. Superior radiological outcomes (fusion >90%) were observed in patients with degenerative disk disease (with and without radiculopathy), spondylolisthesis, and failed posterior fusion, whereas in adjacent segment disease, it was 80%. CONCLUSION: ALIF is an effective treatment for degenerative disk disease (with and without radiculopathy) and spondylolisthesis. Although results were promising for scoliosis, failed posterior fusion, and adjacent segment disease, further studies are necessary to establish the effectiveness of ALIF in these conditions.

Indications for anterior lumbar interbody fusion.

Anterior lumbar interbody fusion (ALIF) has become a widely recognized surgical technique for degenerative pathology of the lumbar spine. Spinal fusion has evolved dramatically ever since the first successful internal fixation by Hadra in 1891 who used a posterior approach to wire adjacent cervical vertebrae in the treatment of fracture-dislocation. Advancements were made to reduce morbidity including bone grafting substitutes, metallic hardware instrumentation and improved surgical technique. The controversy regarding which surgical approach is best for treating various pathologies of the lumbar spine still exists. Despite being an established treatment modality, current indications of ALIF are yet to be clearly defined in the literature. This article discusses the current literature on indications on ALIF surgery.

Multiplexing RT-PCR for the detection of multiple miRNA species in small samples.

MicroRNAs are short (approximately 22 nucleotides), non-coding RNAs that play critical roles in gene regulation and may be used as rapid precise diagnostic indicators of early stages of cancer. The small size of these RNAs makes detection of multiple microRNA species in very small samples problematic. Here we investigate the parameters associated with multiplexing RT-PCR to obtain relative abundance profiles of multiple microRNAs in small sample sizes down to the amount of RNA found in a single cell.