Conserved L464 in p97 D1-D2 linker is critical for p97 cofactor regulated ATPase activity.

p97 protein is a highly conserved, abundant, functionally diverse, structurally dynamic homohexameric AAA enzyme-containing N, D1, and D2 domains. A truncated p97 protein containing the N and D1 domains and the D1-D2 linker (ND1L) exhibits 79% of wild-type (WT) ATPase activity whereas the ND1 domain alone without the linker only has 2% of WT activity. To investigate the relationship between the D1-D2 linker and the D1 domain, we produced p97 ND1L mutants and demonstrated that this 22-residue linker region is essential for D1 ATPase activity. The conserved amino acid leucine 464 (L464) is critical for regulating D1 and D2 ATPase activity by p97 cofactors p37, p47, and Npl4-Ufd1 (NU). Changing leucine to alanine, proline, or glutamate increased the maximum rate of ATP turnover (kcat) of p47-regulated ATPase activities for these mutants, but not for WT. p37 and p47 increased the kcat of the proline substituted linker, suggesting that they induced linker conformations facilitating ATP hydrolysis. NU inhibited D1 ATPase activities of WT and mutant ND1L proteins, but activated D2 ATPase activity of full-length p97. To further understand the mutant mechanism, we used single-particle cryo-EM to visualize the full-length p97L464P and revealed the conformational change of the D1-D2 linker, resulting in a movement of the helix-turn-helix motif (543-569). Taken together with the biochemical and structural results we conclude that the linker helps maintain D1 in a competent conformation and relays the communication to/from the N-domain to the D1 and D2 ATPase domains, which are ∼50 Šaway.

Altered cofactor regulation with disease-associated p97/VCP mutations.

Dominant mutations in p97/VCP (valosin-containing protein) cause a rare multisystem degenerative disease with varied phenotypes that include inclusion body myopathy, Paget's disease of bone, frontotemporal dementia, and amyotrophic lateral sclerosis. p97 disease mutants have altered N-domain conformations, elevated ATPase activity, and altered cofactor association. We have now discovered a previously unidentified disease-relevant functional property of p97 by identifying how the cofactors p37 and p47 regulate p97 ATPase activity. We define p37 as, to our knowledge, the first known p97-activating cofactor, which enhances the catalytic efficiency (kcat/Km) of p97 by 11-fold. Whereas both p37 and p47 decrease the Km of ATP in p97, p37 increases the kcat of p97. In contrast, regulation by p47 is biphasic, with decreased kcat at low levels but increased kcat at higher levels. By deleting a region of p47 that lacks homology to p37 (amino acids 69-92), we changed p47 from an inhibitory cofactor to an activating cofactor, similar to p37. Our data suggest that cofactors regulate p97 ATPase activity by binding to the N domain. Induced conformation changes affect ADP/ATP binding at the D1 domain, which in turn controls ATPase cycling. Most importantly, we found that the D2 domain of disease mutants failed to be activated by p37 or p47. Our results show that cofactors play a critical role in controlling p97 ATPase activity, and suggest that lack of cofactor-regulated communication may contribute to p97-associated disease pathogenesis.

Oncoplastic Techniques and Tricks to Have in Your Toolbox.

SUMMARY: Oncoplastic breast reconstruction seeks to address partial mastectomy defects in the setting of breast-conserving surgery to achieve superior aesthetic outcomes with comparable oncologic safety compared with traditional breast conservation surgery. As such, oncoplastic breast-conserving surgery has grown in popularity in recent years. Several techniques have been used to displace the volume with the remaining breast tissue or replace it with local soft-tissue options, with decision-making guided by patient and tumor characteristics, additional treatment requirements, patient preference, and available tissue resources. The purpose of this review is to provide an overview of considerations in oncoplastic breast reconstruction with a focus on techniques and tips to achieve optimal outcomes.

Personalizing Locoregional Therapy in Patients With Breast Cancer in 2024: Tailoring Axillary Surgery, Escalating Lymphatic Surgery, and Implementing Evidence-Based Hypofractionated Radiotherapy.

The management of axillary lymph nodes in breast cancer is continually evolving. Recent data now support omitting axillary lymph node dissection (ALND) in most patients with metastases in up to two sentinel lymph nodes (SLNs) during upfront surgery and those with residual isolated tumor cells after neoadjuvant chemotherapy (NACT). In the upfront surgery setting, ALND is still indicated, however, in patients with clinically node-positive breast cancer or more than two positive SLNs and, after NACT, in case of residual micrometastases and macrometastases. Omission of the sentinel lymph node biopsy (SLNB) can be considered in many postmenopausal patients with small luminal breast cancer, particularly when axillary ultrasound is negative. Several randomized controlled trials (RCTs) are currently aiming at eliminating the remaining indications for ALND and also establishing omission of SLNB in a broader patient population. The movement to deescalate axillary staging is in part because of the association between ALND and lymphedema, which is swelling of an extremity because of lymphatic damage and obstructed lymphatic drainage. To reduce the risk of developing this condition, patients undergoing ALND can undergo reverse mapping of the axilla and immediate reconstruction or bypass of the lymphatics from the involved extremity. Decongestion and compression are the foundation of conservative treatment for established lymphedema, while lymphovenous bypass and lymph node transfer are surgical procedures to address the physiologic dysfunction. Radiotherapy is an essential component of breast locoregional therapy: more than three decades of radiation research has optimized treatment according to patient's risk of local recurrence while substantially reducing the number of treatment visits. High-quality RCTs have shown the efficacy and safety of hypofractionation-more than 2Gy radiation dose per treatment (fraction)-significantly reducing the burden of radiotherapy treatment for many patients with breast cancer. In 2024, guidelines recommend no more than 15-16 fractions for whole-breast and nodal radiotherapy, with some recommending five fractions for whole-breast radiotherapy. In addition, simultaneous integrated boost (SIB) has been shown to be noninferior to sequential boost with regards to ipsilateral breast tumor recurrence with similar or reduced long-term side effects, also reducing overall treatment length. Further RCTs are underway investigating other indications for five fractions, including SIB and regional node irradiation, such that, in future, it may be possible for the majority of breast radiotherapy patients to be treated with a 1-week course. This manuscript serves to outline the latest updates on axillary surgical staging, lymphatic surgery, and evidence-based radiotherapy in the treatment of breast cancer.

Pediatric instant noodle burns: A ten-year single center retrospective study.

INTRODUCTION: Children are particularly vulnerable to scald injuries, and hot beverages/foods are often implicated in this subset of pediatric burns. Burns from instant noodles are common and thus an attractive target for burn prevention. The purpose of this study is to characterize the frequency, demographics, outcomes, and circumstances of pediatric instant noodle burns to guide future educational and prevention efforts. METHODS: This is a retrospective review of all pediatric patients (<18 years) admitted to the University of Chicago Burn Center with a diagnosis of scald injury between 2010 and 2020. Burns caused by instant noodles were identified and compared to all other scald burns over this period. RESULTS: Among 790 pediatric scald burns, 245 (31.0 %) were attributed to instant noodles. Compared to other scalds, patients with instant noodle burns were older (5.4 vs. 3.8 years, p < 0.001), equally likely to be male (51 % vs. 54 %, p = 0.488), and more likely to be Black/African American (90.6 % vs. 75.2 %, p < 0.001). Patients with instant noodle burns lived in zip codes with a lower average childhood opportunity index score (9.9 vs. 14.6, p < 0.001). In terms of circumstances, children with instant noodle burns were more likely to be unsupervised at the time of injury (37 % vs 21 %, p < 0.001). Instant noodle burns were smaller (3.6 % total body surface area (TBSA) vs. 5.8 % TBSA, p < 0.001) and less likely to require operative intervention (29 % vs. 41 %, p < 0.001). Instant noodle burns had a shorter length of stay (4.2 days vs. 6.4 days, p < 0.001), but similar adjusted length of stay (1.7 days/%TBSA vs. 1.5 days/%TBSA, p = 0.18) and experienced similar complication rates (10 % vs. 15 %, p = 0.06). CONCLUSION: Instant noodle burns comprised nearly one-third of all pediatric scald burn admissions at our institution, a higher proportion than previously reported. While less severe than other scald burns in this series, instant noodles injuries still demonstrated a need for hospitalization and operative intervention. Instant noodle burns disproportionately affected Black/African American patients, as well as from neighborhoods with lower socioeconomic status. These findings suggest that focused burn prevention efforts may be successful at reducing the incidence of these common, but serious injuries.

Adipose-derived stem cell extracellular vesicles: A systematic review✰.

INTRODUCTION: Extracellular vesicles (EVs) are cell-secreted packages that deliver cargo to target cells to effect functional and phenotypic changes. They are secreted by many different cell types, including adipose-derived stem cells (ADSCs), which are a promising field of study in regenerative medicine. Our aim was to perform a systematic review of the literature to summarize the scientific work that has been conducted on ADSC EVs to date. METHODS: The Pubmed database was queried with keywords (and variations of) "adipose derived stem cell," "stromal vascular fraction," and "extracellular vesicles." We excluded review papers, then manually screened articles based on title and abstract. Full-text articles were assessed for eligibility to include in final review. RESULTS: While an extensive body of research exists on EVs, a much smaller proportion of that is original research on ADSC EVs. Of 44 manuscripts that met our database search criteria, 21 articles were selected for our systematic review. CONCLUSION: ADSC EVs were found to exert effects on angiogenesis, cell survival and apoptosis, inflammation, tissue regeneration, and reduction of disease pathology. Further studies examine characteristics of ADSC EVs. Future work should aim to further detail the safety profiles of ADSC EVs given their potential for cell-based therapies. The body of research studies characterizing ADSC EVs continues to expand, and much work remains to be done before human pilot studies can be considered. To our knowledge, we offer the first systematic review summarizing the research on ADSC EVs and their determined roles to date.

Angioplasty in critical limb ischaemia: one-year limb salvage results.

INTRODUCTION: Lower extremity amputation prevention (LEAP) is an ongoing programme in our institution aimed at limb salvage in patients with critical limb ischaemia (CLI). Patients in the LEAP programme with reconstructible anatomy on initial Doppler imaging received either bypass surgery or percutaneous transluminal balloon angioplasty (PTA). We describe the 1-year limb salvage rates in 46 consecutive patients with CLI who received PTA in 2005. CLINICAL PICTURE: A total of 46 patients, 28 women and 18 men, between the ages of 40 and 91 years old (mean age, 70.8) received PTA in 2005. The most common presenting symptom was rest pain (n = 23), followed by pre-existing gangrene (n = 20), non-healing ulcer (n = 17) and cellulitis (n = 8). The majority of the patients (57%) had 3 to 4 risk factors. Diabetes mellitus (91%) and hypertension (80%) were the 2 most common risk factors. The patients were kept under surveillance for periods ranging from 12 to 21 months with a mean of 13.3 months, both clinically and with haemodynamic measurements [ankle-brachial index (ABI), toe pressure (TP) and digital-brachial index (DBI)]. TREATMENT: The aim of PTA is to achieve straight-line flow from the abdominal aorta down to either a patent dorsalis pedis or plantar arch with limb salvage as the ultimate goal. The patterns of the treated segments were as follows: aorto-iliac occlusions (n = 3), pure infrapopliteal disease (n = 5), femoropopliteal disease with at least 1 good infrapopliteal run-off vessel (n = 16) and combined femoropopliteal and infrapopliteal disease (n = 25). Technical success was achieved in 89% of patients (41 out of 46 patients). The most common cause of technical failure is the inability to cross long chronic total occlusions. OUTCOME: Paired T test was performed and showed statistically significant improvement in haemodynamic markers within the technically successful group. This included increase in the mean ABI from 0.62 (preangioplasty) to 0.91 (Day 1 post-angioplasty), an increase of 0.29 [95% confidence interval (95% CI), 0.1953 to 0.3875; P <0.001]. One year post-angioplasty, the mean ABI was 0.84, an increase of 0.22 (95% CI 0.1512 to 0.3121; P <0.001). There was also significant increase in the mean DBI of 0.17 from 0.23 to 0.41 (pre-angioplasty versus Day 1 post angioplasty - 95% CI of 0.1006 to 0.2433; P <0.001). In addition, significant increase in the mean TP of 28.2 mmHg from 36.8 to 63.2 mmHg (pre-angioplasty versus Day 1 post angioplasty - 95% CI, 18.493 to 37.939; P <0.001) was also noted. Of the 23 patients who presented with rest pain, total abolishment of symptoms was achieved in 21 patients (91%). Healing of pre-existing gangrene was attained in 15 patients (66%). Five patients subsequently received minor amputation for pre-existing gangrene. Clinical improvement in all the patients who presented with non-healing ulcers (n = 17) and cellulitis (n = 8) was attained. More importantly, all healed ulcers remained healed throughout the study period. The limb salvage rates were 93% at 1 month, 87% at 3 months, 82% at 6 months and 78% at 1 year. CONCLUSION: Angioplasty is a safe and effective limb salvage method in patients with CLI and has a high 1-year limb salvage rate.

Dermatomyositis Developing Post Neoadjuvant Chemotherapy and Lumpectomy.

Dermatomyositis is an idiopathic inflammatory myopathy known to occur as a paraneoplastic syndrome. The course of dermatomyositis is commonly reported to mirror the course of the malignancy. Here, we report a case of dermatomyositis that developed in a patient after lump- ectomy and completed chemotherapeutic treatment.

Evaluating p97 Inhibitor Analogues for Potency against p97-p37 and p97-Npl4-Ufd1 Complexes.

We previously found that the p97 cofactor, p47, significantly decreased the potency of some ATP-competitive p97 inhibitors such as ML240 [2-(2-amino-1H-benzo[d]imidazol-1-yl)-N-benzyl-8-methoxyquinazolin-4-amine] and ML241 [2-(2H-benzo[b][1,4]oxazin-4(3H)-yl)-N-benzyl-5,6,7,8 tetrahydroquinazolin-4-amine]. In this study, we aimed to evaluate inhibitor potencies against two additional p97 cofactor complexes, p97-p37 and p97-Npl4-Ufd1. We focused on these two cofactor complexes, because the protein sequence of p37 is 50 % identical to that of p47, and the Npl4-Ufd1 heterodimer (NU) is the most-studied p97 cofactor complex. We screened 200 p97 inhibitor analogues for their ability to inhibit the ATPase activity of p97 alone and of p97-p37 and p97-NU complexes. In contrast to the effect of p47, p37 and NU did not significantly change the potencies of most of the compounds. These results highlight differences among p97 cofactors in influencing p97 conformation and effects of inhibitors on p97 complexes, as compared to p97 alone. Continued efforts are needed to advance the development of complex-specific p97 inhibitors.

Crucial individuals in the help-seeking pathway of Chinese caregivers of relatives with early psychosis in Hong Kong.

This study attempted to identify the crucial individuals in the help-seeking pathways of Chinese caregivers of relatives suffering from early psychosis in Hong Kong. In-depth interviews with 58 caregivers were conducted. The findings suggest that although the family caregivers usually initiated the help-seeking process, informal network members were instrumental in confirming the presence of mental illness and encouraged the caregivers to seek external help. School social workers acted as a bridge between the informal and formal networks and referred the adolescents for psychiatric consultations. However, it was found that some of the ill relatives did not recognize the severity of their mental health problems, which posed a major obstacle to help seeking. Contrary to the claims in overseas literature, the informal network members' accurate recognition of mental illness quickened the help-seeking process. Individual, cultural, and social institutional factors were identified and used to further explain these characteristics of help seeking. Implications for social work practice are highlighted.