Cep104 is a component of the centriole distal tip complex that regulates centriole growth and contributes to Drosophila spermiogenesis.

Proper centrosome number and function relies on the accurate assembly of centrioles, barrel-shaped structures that form the core duplicating elements of the organelle. The growth of centrioles is regulated in a cell cycle-dependent manner; while new daughter centrioles elongate during the S/G2/M phase, mature mother centrioles maintain their length throughout the cell cycle. Centriole length is controlled by the synchronized growth of the microtubules that ensheathe the centriole barrel. Although proteins exist that target the growing distal tips of centrioles, such as CP110 and Cep97, these proteins are generally thought to suppress centriolar microtubule growth, suggesting that distal tips may also contain unidentified counteracting factors that facilitate microtubule polymerization. Currently, a mechanistic understanding of how distal tip proteins balance microtubule growth and shrinkage to either promote daughter centriole elongation or maintain centriole length is lacking. Using a proximity-labeling screen in Drosophila cells, we identified Cep104 as a novel component of a group of evolutionarily conserved proteins that we collectively refer to as the distal tip complex (DTC). We found that Cep104 regulates centriole growth and promotes centriole elongation through its microtubule-binding TOG domain. Furthermore, analysis of Cep104 null flies revealed that Cep104 and Cep97 cooperate during spermiogenesis to align spermatids and coordinate individualization. Lastly, we mapped the complete DTC interactome and showed that Cep97 is the central scaffolding unit required to recruit DTC components to the distal tip of centrioles.

Polo-like kinase 4 homodimerization and condensate formation regulate its own protein levels but are not required for centriole assembly.

Polo-like kinase 4 (Plk4) is the master-regulator of centriole assembly, and cell cycle-dependent regulation of its activity maintains proper centrosome number. During most of the cell cycle, Plk4 levels are nearly undetectable due to its ability to autophosphorylate and trigger its own ubiquitin-mediated degradation. However, during mitotic exit, Plk4 forms a single aggregate on the centriole surface to stimulate centriole duplication. Whereas most Polo-like kinase family members are monomeric, Plk4 is unique because it forms homodimers. Notably, Plk4 trans-autophosphorylates a degron near its kinase domain, a critical step in autodestruction. While it is thought that the purpose of homodimerization is to promote trans-autophosphorylation, this has not been tested. Here, we generated separation-of-function Plk4 mutants that fail to dimerize and show that homodimerization creates a binding site for the Plk4 activator, Asterless. Surprisingly, however, Plk4 dimer mutants are catalytically active in cells, promote centriole assembly, and can trans-autophosphorylate through concentration-dependent condensate formation. Moreover, we mapped and then deleted the weak-interacting regions within Plk4 that mediate condensation and conclude that dimerization and condensation are not required for centriole assembly. Our findings suggest that Plk4 dimerization and condensation function simply to down-regulate Plk4 and suppress centriole overduplication.

Chronic Constipation in Adults.

Chronic constipation has significant quality-of-life implications. Modifiable risk factors include insufficient physical activity, depression, decreased caloric intake, and aggravating medication use. Chronic constipation is classified as primary (normal transit, slow transit, defecatory disorders, or a combination) or secondary (due to medications, chronic diseases, or anatomic abnormalities). Evaluation begins with a detailed history, medication reconciliation, and physical examination. Routine use of laboratory studies or imaging, including colonoscopy, is not recommended in the absence of alarm symptoms. Patients with alarm symptoms or who are overdue for colorectal cancer screening should be referred for colonoscopy. First-line treatment for primary constipation includes ensuring adequate fluid intake, dietary fiber supplementation, and osmotic laxatives. Second-line therapy includes a brief trial of stimulant laxatives followed by intestinal secretagogues. If the initial treatment approach is ineffective, patients should be referred to gastroenterology for more specialized testing, such as anorectal manometry and a balloon expulsion test. Patients with refractory constipation may be considered for surgery. Those in whom pelvic floor dysfunction is identified early should be referred for pelvic floor therapy with biofeedback while first-line medications, such as bulk or osmotic laxatives, are initiated.

Assessment of an Educational Tool for Pediatric Cardiac Nurses on Individualized Family-Centered Developmental Care.

BACKGROUND: Prevention of neurodevelopmental sequelae is a high priority in the care of infants with congenital heart defects. Individualized family-centered developmental care has been identified as a promising approach to promote infant neurodevelopment during hospitalization. OBJECTIVE: To educate nurses on the concept of individualized family-centered developmental care and its application to nursing practice and to reduce perceived barriers to its implementation. METHODS: Two evidence-based visual educational tools called "developmental care flowers" were created and implemented in the inpatient and procedural units of a cardiac center. Each flower petal represented a core component of individualized family-centered developmental care: cue-based care, patient positioning, supportive environment, and parent engagement. Surveys were administered before and after the educational intervention to assess changes in nurses' knowledge and perceptions of individualized family-centered developmental care. RESULTS: Nurses reported that the developmental care flowers improved their understanding of individualized family-centered developmental care. The educational tools reduced some perceived barriers to implementation of this care model and increased nurse-reported inclusion of parents in care. Qualitative feedback from staff members regarding the tools was positive and acknowledged that individualized family-centered developmental care should be an ongoing priority. CONCLUSIONS: The inpatient and procedural developmental care flowers are useful tools for educating nurses about individualized family-centered developmental care. They could be revised into more interactive tools that might be used to educate parents and further support the integration of this care concept into nursing practice.

Predicting Resolvin D1 Pharmacokinetics in Humans with Physiologically-Based Pharmacokinetic Modeling.

Sjögren's syndrome (SS) is an autoimmune disease with no effective treatment options. Resolvin D1 (RvD1) belongs to a class of lipid-based specialized pro-resolving mediators that showed efficacy in preclinical models of SS. We developed a physiologically-based pharmacokinetic (PBPK) model of RvD1 in mice and optimized the model using plasma and salivary gland pharmacokinetic (PK) studies performed in NOD/ShiLtJ mice with SS-like features. The predictive performance of the PBPK model was also evaluated with two external datasets from the literature reporting RvD1 PKs. The PBPK model adequately captured the observed concentrations of RvD1 administered at different doses and in different species. The PKs of RvD1 in virtual humans were predicted using the verified PBPK model at various doses (0.01-10 mg/kg). The first-in-human predictions of RvD1 will be useful for the clinical trial design and translation of RvD1 as an effective treatment strategy for SS.

Sex-dependent Regeneration Patterns in Mouse Submandibular Glands.

Our previous studies indicated that YIGSR-A99 peptides chemically conjugated to fibrin hydrogel (FH) and applied to wounded submandibular gland (SMG) in vivo, formed new organized salivary tissue, whereas wounded SMG treated with FH alone or in the absence of a scaffold showed disorganized collagen formation and poor tissue healing. While these studies indicated that damaged SMG grow and differentiate when treated with FH containing L1 peptide, they were performed only in female mice. However, there is a well-established sexual dimorphism present in mouse SMG (e.g., males develop well-differentiated granular convoluted tubules, but these structures are poorly developed in females) and little is known about how these sex differences influence wound healing events. Therefore, the goal of this study was to conduct comparative analyses of regeneration patterns in male and female mice using L1p-FH in a wounded SMG mouse model. Particularly, we focused on sex-dependent wound healing events such as macrophage polarization, vascularization, tissue organization, and collagen deposition, and how these events affect salivary gland functioning.

Using cell sheets to regenerate mouse submandibular glands.

Temperature-responsive polymer grafted tissue culture dishes release cells as confluent living sheets in response to small changes in temperature, with recovered cell sheets retaining cell-cell communications, functional extracellular matrices and tissue-like behaviors. These features promote tissue regeneration and improve transplantation efficacy in various tissues including cartilage, heart, kidney, liver, endometrium, cornea, middle ear, periodontium, and esophageal living sheet transplants. However, the functional effects of cell sheets for salivary gland regeneration to treat hyposalivation have not yet been studied. Thus, the present study aims to both establish the viability of thermoresponsive cell sheets for use in salivary glands and then explore the delivery option (i.e., single vs. multiple layers) that would result in the most complete tissue growth in terms of cell differentiation and recovered tissue integrity. Results indicate that single cell sheets form polarized structures that maintain cell-cell junctions and secretory granules in vitro while layering of two-single cell sheets forms a glandular-like pattern in vitro. Moreover, double layer cell sheets enhance tissue formation, cell differentiation and saliva secretion in vivo. In contrast, single cell sheets demonstrated only modest gains relative to the robust growth seen with the double layer variety. Together, these data verify the utility of thermoresponsive cell sheets for use in salivary glands and indicates the double layer form to provide the best option in terms of cell differentiation and recovered tissue integrity, thereby offering a potential new therapeutic strategy for treating hyposalivation.

Nursing Practice With Transthoracic Intracardiac Catheters in Children: International Benchmarking Study.

BACKGROUND: Transthoracic intracardiac catheters are central catheters placed in the operating room at the conclusion of cardiac surgery for infants and children. Complications associated with these catheters (eg, bleeding, migration, premature removal, infection, leakage, and lack of function) have been described. However, no researchers have addressed the nursing management of these catheters in the intensive care unit, including catheter dressing and securement, mobilization of patients, and flushing the catheters, or the impact of these interventions on patients' outcomes. OBJECTIVES: To internationally benchmark current nursing practice associated with care of infants and children with transthoracic intracardiac catheters. METHODS: In a cross-sectional, descriptive study of nursing practice in infants and children with transthoracic intracardiac catheters, a convenience sample of bedside and advanced practice nurses was recruited to complete an online survey to benchmark current practice. The survey included questions on criteria for catheter insertion and removal, dressing care, flushing practice, securement, and mobilization of patients. RESULTS: Transthoracic intracardiac catheters are used by most centers that provide care for infants and children after open heart surgery. A wide range of practices was reported. CONCLUSIONS: Standardizing the use and care of transthoracic intracardiac catheters can improve the safety and efficacy of their use in infants and children and promote safe and early postoperative mobilization of patients.

Synergistic effects of laminin-1 peptides, VEGF and FGF9 on salivary gland regeneration.

Hyposalivation is associated with radiation therapy, Sjögren's syndrome and/or aging, and is a significant clinical problem that decreases oral health and overall health in many patients and currently lacks effective treatment. Hence, methods to regenerate salivary glands and restore saliva secretion are urgently needed. To this end, this study describes the modification of fibrin hydrogels with a combination of laminin-1 peptides (YIGSR and A99) and human growth factors (vascular endothelial growth factor and fibroblast growth factor 9) to enhance regeneration in a salivary gland injury mouse model. Our results indicate that these fortified hydrogels enhanced angiogenesis and neurogenesis while promoting formation of acinar structures, thereby leading to enhanced saliva secretion. Such functional recovery indicates salivary gland regeneration and suggests that our technology may be useful in promoting gland regeneration and reversing hyposalivation in a clinical setting. STATEMENT OF SIGNIFICANCE: We engineered Fibrin Hydrogels (FH) to contain multiple regenerative cues including laminin-1 peptides (L1p) and growth factors (GFs). L1p and GF modified FH were used to induce salivary gland regeneration in a wounded mouse model. Treatment with L1p and GF modified FH promoted salivary epithelial tissue regeneration, vascularization, neurogenesis and healing as compared to L1p-FH or FH alone. Results indicate that L1p and GF modified FH can be used for future therapeutic applications.

Aspirin Triggered Resolvin D1 reduces inflammation and restores saliva secretion in a Sjögren's syndrome mouse model.

OBJECTIVES: SS is characterized by chronic inflammation of the salivary glands leading to loss of secretory function, thereby suggesting specialized pro-resolving mediators targeting inflammation to be a viable option for treating SS. Previous studies demonstrated that aspirin-triggered resolvin D1 (AT-RvD1) prevents chronic inflammation and enhances saliva secretion in a SS-like mouse model when applied before disease onset. However, this therapy cannot be used in SS patients given that diagnosis occurs post-disease onset and no reliable screening methods exist. Therefore, we examined whether treatment with AT-RvD1 reduces SS-like features in a mouse model post-disease onset. METHODS: Tail vein injections were performed in a SS-like mouse model both with and without AT-RvD1 post-disease onset for 8 weeks, with salivary gland function and inflammatory status subsequently determined. RESULTS: Treatment of a SS-like mouse model with AT-RvD1 post-disease onset restores saliva secretion in both females and males. Moreover, although AT-RvD1 treatment does not reduce the overall submandibular gland lymphocytic infiltration, it does reduce the number of T helper 17 cells within the infiltrates in both sexes. Finally, AT-RvD1 reduces SS-associated pro-inflammatory cytokine gene and protein expression levels in submandibular glands from female but not male mice. CONCLUSION: AT-RvD1 treatment administered post-disease onset reduces T helper 17 cells and successfully restores salivary gland function in a SS mouse model with variable effects noted by sex, thus warranting further examination of both the causes for the sex differences and the mechanisms responsible for the observed treatment effect.

Utilization of the Premature Birth Knowledge Scale to Assess Pediatric Provider Knowledge of Neurodevelopmental Outcomes.

INTRODUCTION: Prematurity affects a significant portion (10-12%) of children in the Unites States, with potential for physical, psychological, neurodevelopmental, and behavioral impairments continuing long past the neonatal period. The specific aim of this research was to evaluate pediatric primary and specialty care providers' knowledge and understanding of neurodevelopmental outcomes of children born prematurely. METHODS: Pediatric nurse practitioner (PNP) members of the National Association of Pediatric Nurse Practitioners participated in an online survey using the 33-item Premature Birth Knowledge Scale (PB-KS) to assess their knowledge of current neurodevelopmental outcomes of children born prematurely. RESULTS: Neither years of practice as a registered nurse nor as a PNP predicted performance on the PB-KS. The mean score on the PB-KS in the PNP sample was 17.8 (possible score = 0-33), with a mean accuracy of 53.9%. Higher scores on the PB-KS were correlated with higher perceived level of preparation to care for children born prematurely. DISCUSSION: To our knowledge, this is the first study to use the PB-KS with pediatric primary and specialty providers. PNPs are uniquely situated to educate and support families facing the long-term consequences of premature birth; to do so they must maintain accurate understanding of current outcomes.

A novel bone morphogenetic protein 2 mutant mouse, nBmp2NLS(tm), displays impaired intracellular Ca2+ handling in skeletal muscle.

We recently reported a novel form of BMP2, designated nBMP2, which is translated from an alternative downstream start codon and is localized to the nucleus rather than secreted from the cell. To examine the function of nBMP2 in the nucleus, we engineered a gene-targeted mutant mouse model (nBmp2NLS(tm)) in which nBMP2 cannot be translocated to the nucleus. Immunohistochemistry demonstrated the presence of nBMP2 staining in the myonuclei of wild type but not mutant skeletal muscle. The nBmp2NLS(tm) mouse exhibits altered function of skeletal muscle as demonstrated by a significant increase in the time required for relaxation following a stimulated twitch contraction. Force frequency analysis showed elevated force production in mutant muscles compared to controls from 10 to 60 Hz stimulation frequency, consistent with the mutant muscle's reduced ability to relax between rapidly stimulated contractions. Muscle relaxation after contraction is mediated by the active transport of Ca(2+) from the cytoplasm to the sarcoplasmic reticulum by sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA), and enzyme activity assays revealed that SERCA activity in skeletal muscle from nBmp2NLS(tm) mice was reduced to approximately 80% of wild type. These results suggest that nBMP2 plays a role in the establishment or maintenance of intracellular Ca(2+) transport pathways in skeletal muscle.