Improvement of fatigue in generalised myasthenia gravis with zilucoplan.

BACKGROUND: Fatigue is a debilitating symptom of myasthenia gravis (MG). The impact of fatigue on MG can be assessed by Quality of Life in Neurological Disorders (Neuro-QoL) Short Form Fatigue scale. Transformation of raw Neuro-QoL fatigue scores to T-scores is a known approach for facilitating clinical interpretation of clinically meaningful and fatigue severity thresholds. METHODS: In the Phase 3, double-blind, placebo-controlled RAISE study (NCT04115293), adults with acetylcholine receptor autoantibody-positive generalised MG (MG Foundation of America Disease Class II-IV) were randomised 1:1 to daily subcutaneous zilucoplan 0.3 mg/kg or placebo for 12 weeks. Patients completing RAISE could opt to receive zilucoplan 0.3 mg/kg in an ongoing, open-label extension study, RAISE-XT (NCT04225871). In this post-hoc analysis, we evaluated the long-term effect of zilucoplan on fatigue in RAISE patients who entered RAISE-XT. We report change in Neuro-QoL Short Form Fatigue T-scores and fatigue severity levels from RAISE baseline to Week 60. RESULTS: Mean Neuro-QoL Short Form Fatigue T-scores improved from baseline to Week 12 in the zilucoplan group (n = 86) with a clinically meaningful difference versus placebo (n = 88; least squares mean difference: - 3.61 (nominal p-value = 0.0060]), and these improvements continued further to Week 60. At Week 12, more patients on zilucoplan (n = 34, 47.2%) experienced improvements in ≥ 1 fatigue severity level from baseline versus placebo (n = 23, 28.4%; p = 0.017). At Week 60, most (n = 55, 65.5%) patients had mild fatigue or none. CONCLUSION: Treatment with zilucoplan demonstrated statistical and clinically meaningful improvements in fatigue scores and severity versus placebo during RAISE, which were sustained to Week 60 in RAISE-XT.

Response-adapted, time-limited venetoclax, umbralisib, and ublituximab for relapsed/refractory chronic lymphocytic leukemia.

ABSTRACT: Many patients with chronic lymphocytic leukemia (CLL) will develop treatment resistance to Bruton tyrosine kinase (BTK) inhibitors. Phosphatidylinositol-3-kinase (PI3K) inhibitors, including umbralisib, have significant clinical activity in relapsed/refractory CLL, but prolonged exposure is associated with potential toxicities. Owing to the synergistic antitumor effects of combined PI3K and BCL-2 inhibition, we sought to explore the feasibility of response-adapted, time-limited therapy to optimize disease control while mitigating the risks of prolonged treatment. We conducted a phase 1/2 clinical trial to determine the safety and efficacy of venetoclax in combination with umbralisib and the anti-CD20 monoclonal antibody, ublituximab, (U2-VeN) in patients with relapsed/refractory CLL (N = 46) and Richter transformation (N = 5). After 12 cycles, treatment was stopped for patients with CLL who achieved undetectable minimal residual disease (uMRD). Adverse events of special interest included diarrhea in 50% of patients (11% grade 3/4), and aspartate aminotransferase and/or alanine aminotransferase elevation in 15 patients (33%), with 3 (7%) grade 3/4. There were no cases of tumor lysis syndrome related to venetoclax, with outpatient initiation in 96% of patients. The intent-to-treat overall response rate for CLL was 98% with best response of 100% in evaluable patients (42% complete responses). The end-of-treatment rate of uMRD at 10-4 in bone marrow was 77% (30/39), including a 71% uMRD rate among 14 patients refractory to prior BTK inhibitor. Time-limited venetoclax and U2 is safe and highly effective combination therapy for patients with relapsed/refractory CLL including those who have been previously treated with covalent BTK inhibitors. This trial was registered on www.clinicaltrials.gov as #NCT03379051.

Se-Glargine: Chemical Synthesis of a Basal Insulin Analogue Stabilized by an Internal Diselenide Bridge.

Insulin has long provided a model for studies of protein folding and stability, enabling enhanced treatment of diabetes mellitus via analogue design. We describe the chemical synthesis of a basal insulin analogue stabilized by substitution of an internal cystine (A6-A11) by a diselenide bridge. The studies focused on insulin glargine (formulated as Lantus® and Toujeo®; Sanofi). Prepared at pH 4 in the presence of zinc ions, glargine exhibits a shifted isoelectric point due to a basic B chain extension (ArgB31 -ArgB32 ). Subcutaneous injection leads to pH-dependent precipitation of a long-lived depot. Pairwise substitution of CysA6 and CysA11 by selenocysteine was effected by solid-phase peptide synthesis; the modified A chain also contained substitution of AsnA21 by Gly, circumventing acid-catalyzed deamidation. Although chain combination of native glargine yielded negligible product, in accordance with previous synthetic studies, the pairwise selenocysteine substitution partially rescued this reaction: substantial product was obtained through repeated combination, yielding a stabilized insulin analogue. This strategy thus exploited both (a) the unique redox properties of selenocysteine in protein folding and (b) favorable packing of an internal diselenide bridge in the native state, once achieved. Such rational optimization of protein folding and stability may be generalizable to diverse disulfide-stabilized proteins of therapeutic interest.

The Role of Hepatobiliary Scintigraphy as the Initial Investigative Modality for Significant Bile Leak following Laparoscopic Cholecystectomy.

INTRODUCTION: Currently, the rate of bile duct injury and leak following laparoscopic cholecystectomy (LC) is still higher than for open surgery. Diverse investigative algorithms were suggested for bile leak, shifting from hepatobiliary scintigraphy (HBS) toward invasive and more sophisticated means. We aimed to analyze the use of biliary scan as the initial modality to investigate significant bile leak in the drain following LC, attempting to avoid potential unnecessary invasive means when the scan demonstrate fair passage of nuclear substance to the intestine, without leak. METHODS: We have conducted a prospective non-randomized study, mandating hepatobiliary scintigraphy first, for asymptomatic patients harboring drain in the gallbladder fossa, leaking more than 50 mL/day following LC. Analysis was done based on medical data from the surgical, gastroenterology, and the nuclear medicine departments. RESULTS: Among 3,124 patients undergoing LC, significant bile leak in the drain was seen in 67 subjects, of whom we started with HBS in 50 patients, presenting our study group. In 27 of whom, biliary scan was the only investigative modality, showing fair passage of the nuclear isotope to the duodenum and absence of leak in the majority. The leak stopped spontaneously within a mean of 3.6 days, and convalescence as well as outpatient clinic follow-up was uneventful. In 23 patients, biliary scan that was interpreted as abnormal was followed by endoscopic retrograde cholangio-pancreatography (ERCP). However, ERCP did not demonstrate any bile leak in 13 subjects. In 17 patients, ERCP was used initially, without biliary scan, suggesting the possibility of avoiding invasive modalities in 7 patients. CONCLUSIONS: Based on a negative predictive value of 91%, we suggest that in cases of asymptomatic significant bile leak through a drain following LC, a normal HBS as the initial modality can safely decrease the rate of using invasive modalities.

Safety and efficacy of zilucoplan in patients with generalised myasthenia gravis (RAISE): a randomised, double-blind, placebo-controlled, phase 3 study.

BACKGROUND: Generalised myasthenia gravis is a chronic, unpredictable, and debilitating rare disease, often accompanied by high treatment burden and with an unmet need for more efficacious and well tolerated treatments. Zilucoplan is a subcutaneous, self-administered macrocyclic peptide complement C5 inhibitor. We aimed to assess safety, efficacy, and tolerability of zilucoplan in patients with acetylcholine receptor autoantibody (AChR)-positive generalised myasthenia gravis. METHODS: RAISE was a randomised, double-blind, placebo-controlled, phase 3 trial that was done at 75 sites in Europe, Japan, and North America. We enrolled patients (aged 18-74 years) with AChR-positive generalised myasthenia gravis (Myasthenia Gravis Foundation of America disease class II-IV), a myasthenia gravis activities of daily living (MG-ADL) score of least 6, and a quantitative myasthenia gravis score of at least 12. Participants were randomly assigned (1:1) to receive subcutaneous zilucoplan 0·3 mg/kg once daily by self-injection, or matched placebo, for 12 weeks. The primary efficacy endpoint was change from baseline to week 12 in MG-ADL score in the modified intention-to-treat population (all randomly assigned patients who received at least one dose of study drug and had at least one post-dosing MG-ADL score). Safety was mainly assessed by the incidence of treatment-emergent adverse events (TEAEs) in all patients who had received at least one dose of zilucoplan or placebo. This trial is registered at ClinicalTrials.gov, NCT04115293. An open-label extension study is ongoing (NCT04225871). FINDINGS: Between Sept 17, 2019, and Sept 10, 2021, 239 patients were screened for the study, of whom 174 (73%) were eligible. 86 (49%) patients were randomly assigned to zilucoplan 0·3 mg/kg and 88 (51%) were assigned to placebo. Patients assigned to zilucoplan showed a greater reduction in MG-ADL score from baseline to week 12, compared with those assigned to placebo (least squares mean change -4·39 [95% CI -5·28 to -3·50] vs -2·30 [-3·17 to -1·43]; least squares mean difference -2·09 [-3·24 to -0·95]; p=0·0004). TEAEs occurred in 66 (77%) patients in the zilucoplan group and in 62 (70%) patients in the placebo group. The most common TEAE was injection-site bruising (n=14 [16%] in the zilucoplan group and n=8 [9%] in the placebo group). Incidences of serious TEAEs and serious infections were similar in both groups. One patient died in each group; neither death (COVID-19 [zilucoplan] and cerebral haemorrhage [placebo]) was considered related to the study drug. INTERPRETATION: Zilucoplan treatment showed rapid and clinically meaningful improvements in myasthenia gravis-specific efficacy outcomes, had a favourable safety profile, and was well tolerated, with no major safety findings. Zilucoplan is a new potential treatment option for a broad population of patients with AChR-positive generalised myasthenia gravis. The long-term safety and efficacy of zilucoplan is being assessed in an ongoing open-label extension study. FUNDING: UCB Pharma.

Melatonin in Newborn Infants Undergoing Surgery: A Pilot Study on Its Effects on Postoperative Oxidative Stress.

Surgery is frequently associated with excessive oxidative stress. Melatonin acts as an antioxidant and transient melatonin deficiency has been described in neonatal surgical patients. This randomized, blinded, prospective pilot study tested the hypothesis that oral melatonin supplementation in newborn infants undergoing surgery is effective in reducing perioperative oxidative stress. A total of twenty-three newborn infants requiring surgery were enrolled: 10 received a single dose of oral melatonin 0.5 mg/kg in the morning, before surgery (MEL group), and 13 newborns served as the control group (untreated group). Plasma concentrations of melatonin, Non-Protein-Bound Iron (NPBI), Advanced Oxidation Protein Products (AOPP), and F2-Isoprostanes (F2-IsoPs) were measured. Both in the pre- and postoperative period, melatonin concentrations were significantly higher in the MEL group than in the untreated group (preoperative: 1265.50 ± 717.03 vs. 23.23 ± 17.71 pg/mL, p < 0.0001; postoperative: 1465.20 ± 538.38 vs. 56.47 ± 37.18 pg/mL, p < 0.0001). Melatonin significantly increased from the pre- to postoperative period in the untreated group (23.23 ± 17.71 vs. 56.47 ± 37.18 pg/mL; pg/mL p = 0.006). In the MEL group, the mean blood concentrations of NPBI, F2-IsoPs, and AOPP significantly decreased from the pre- to the postoperative period (4.69 ± 3.85 vs. 1.65 ± 1.18 micromol/dL, p = 0.049; 128.40 ± 92.30 vs. 50.25 ± 47.47 pg/mL, p = 0.037 and 65.18 ± 15.50 vs. 43.98 ± 17.92 micromol/dL, p = 0.022, respectively). Melatonin concentration increases physiologically from the pre- to the postoperative period, suggesting a defensive physiologic response to counteract oxidative stress. The administration of exogenous melatonin in newborn infants undergoing surgery reduces lipid and protein peroxidation in the postoperative period, showing a potential role in protecting babies from the deleterious consequences of oxidative stress.

Unusual Adverse Events in a Patient With BRAF-Mutated Non-Small Cell Lung Cancer Treated With BRAF/MEK Inhibition.

BRAF/MEK inhibition remains standard of care for treatment of BRAF-mutated non-small cell lung cancer (NSCLC). Although common adverse events (AEs) have been reported through clinical trials and ongoing clinical practice, only a handful of reports have detailed unusual adverse events associated with these medications. This report presents a patient with BRAF-mutated NSCLC treated with dabrafenib and trametinib who experienced 2 unusual AEs-Sweet syndrome and MEK-associated retinopathy-that responded to steroid treatment. The patient was able to continue BRAF/MEK inhibition through a coordinated multidisciplinary approach. This case highlights the importance for all clinicians to recognize unusual AEs associated with BRAF/MEK inhibition, particularly in the setting of expanded use for all BRAF V600E-mutated solid tumors.

Integrating transition readiness assessment into clinical practice: Adaptation of the UNC TRXANSITION index into the Cerner electronic medical record.

PURPOSE: To describe the process of developing, and evaluating the feasibility and acceptability of, an EMR-based transition readiness assessment. DESIGN AND METHODS: A Cerner-based version of the UNC TRxANSITION Index was implemented across four pediatric subspecialty clinics: epilepsy, inflammatory bowel disease; type 1 diabetes, oncology survivorship. The feasibility was assessed by each's clinic's ability to meet form completion goals and their assessment rate. Acceptability was assessed via family refusal rate, a staff-completed feedback questionnaire, and whether the form was adopted into routine clinical care after completion of the pilot study. RESULTS: All clinics met form completion goals (N = 10/clinic). The assessment rate ranged from 66 to 100% across clinics. No families refused completion of the form. Most staff (70%) reported completing the form in <10 min. Staff reported on challenges experienced and provided recommendations to streamline administration and enhance clinical care. All staff reported the form helped them identify knowledge gaps in their patients. Two clinics continued using the form following completion of the pilot study. CONCLUSIONS: Implementation was most feasible in clinics that were well-staffed and had lengthier patient visits, however, time and staff resources were the biggest challenges to implementation across clinics. Based on staff feedback to improve efficiency and developmentally-tailor assessment, the form will be divided into Beginner Skills and Advanced Skills. PRACTICAL IMPLICATIONS: Integrating transition readiness assessment into the EMR has the potential to improve clinical care by facilitating staff's ability to efficiently identify knowledge gaps in their transition-aged patients and intervene.

Single-chain insulin analogs threaded by the insulin receptor αCT domain.

Insulin is a mainstay of therapy for diabetes mellitus, yet its thermal stability complicates global transportation and storage. Cold-chain transport, coupled with optimized formulation and materials, prevents to some degree nucleation of amyloid and hence inactivation of hormonal activity. These issues hence motivate the design of analogs with increased stability, with a promising approach being single-chain insulins (SCIs), whose C domains (foreshortened relative to proinsulin) resemble those of the single-chain growth factors (IGFs). We have previously demonstrated that optimized SCIs can exhibit native-like hormonal activity with enhanced thermal stability and marked resistance to fibrillation. Here, we describe the crystal structure of an ultrastable SCI (C-domain length 6; sequence EEGPRR) bound to modules of the insulin receptor (IR) ectodomain (N-terminal α-subunit domains L1-CR and C-terminal αCT peptide; "microreceptor" [µIR]). The structure of the SCI-µIR complex, stabilized by an Fv module, was determined using diffraction data to a resolution of 2.6 Å. Remarkably, the αCT peptide (IR-A isoform) "threads" through a gap between the flexible C domain and the insulin core. To explore such threading, we undertook molecular dynamics simulations to 1) compare threaded with unthreaded binding modes and 2) evaluate effects of C-domain length on these alternate modes. The simulations (employing both conventional and enhanced sampling simulations) provide evidence that very short linkers (C-domain length of -1) would limit gap opening in the SCI and so impair threading. We envisage that analogous threading occurs in the intact SCI-IR complex-rationalizing why minimal C-domain lengths block complete activity-and might be exploited to design novel receptor-isoform-specific analogs.

Challenges in abdominal re-exploration for war casualties following on-site abdominal trauma surgery and subsequent delayed arrival to definitive medical care abroad - an unusual scenario.

BACKGROUND: During the Syrian civil war, patients were initially treated on-site in Syria and later transferred to medical centers in Israel. Relevant details concerning the exact nature of injury and medical/surgical care received in Syria were unavailable to clinicians in Israel. Many of these patients required abdominal re-exploration for obvious or suspected problems related to their injury. Our aim is to present our approach to abdominal trauma patients who survived initial on-site surgery and needed subsequent abdominal re-exploration abroad, in our medical center. METHODS: Clinical data from all medical records were retrospectively analyzed. Each patient underwent total body computerized tomography on arrival, revealing diverse multi-organ trauma. We divided the patient population who had abdominal trauma into 4 sub-groups according to the location in which abdominal surgical intervention was performed (abdominal surgery performed only in Syria, surgery in Syria and subsequent re-laparotomy in Israel, abdominal surgery only in Israel, and management of patients without abdominal surgical intervention). We focused on missed injuries and post-operative complications in the re-laparotomy sub-group. RESULTS: By July 2018, 1331 trauma patients had been admitted to our hospital, of whom 236 had suffered abdominal trauma. Life-saving abdominal intervention was performed in 138 patients in Syria before arrival to our medical center. A total of 79 patients underwent abdominal surgery in Israel, of whom 46 (33%) required re-laparotomy. The absence of any communication between the surgical teams across the border markedly affected our medical approach. Indications for re-exploration included severe peritoneal inflammation, neglected or overlooked abdominal foreign bodies, hemodynamic instability and intestinal fistula. Mortality occurred in 37/236 patients, with severe abdominal trauma as the main cause of fatality in 10 of them (4.2%), usually following urgent re-laparotomy. CONCLUSIONS: Lack of information about the circumstances of injury in an environment of catastrophe in Syria at the time and the absence of professional communication between the surgical teams across the border markedly dictated our medical approach. Our concerns were that some patients looked deceptively stable while others had potentially hidden injuries. We had no information on who had had definitive versus damage control surgery in Syria. The fact that re-operation was not performed by the same team responsible for initial abdominal intervention also posed major diagnostic challenges and warranted increased clinical suspicion and a change in our standard medical approach.

Patient Outcomes After Minimally Invasive Excision of Lumbar Synovial Cysts, With and Without a Spondylolisthesis, in an Ambulatory Care Center Setting.

BACKGROUND: Lumbar synovial cysts are thought to signal facet joint degeneration and possible instability, leading some surgeons to routinely add a fusion to the decompressive procedure. These recommendations were formulated before the minimally invasive surgery (MIS) era. Here we describe our outcomes in surgical treatment of lumbar synovial cysts using MIS techniques. METHODS: The charts of 117 patients who underwent MIS resection of a synovial cyst were retrospectively reviewed. All surgeries were carried out in an ambulatory surgery center (ASC). The preoperative and postoperative visual analog scale (VAS) and Oswestry Disability Index (ODI) were collected prospectively. Surgical variables and complications were also reviewed. The subset of 48 patients followed for over 1 year was analyzed, and the outcome of patients with and without a spondylolisthesis was compared. RESULTS: A total of 117 patients underwent MIS decompression of a synovial cyst. Postoperative follow-up ranged from 3 to 12 months. There were no perioperative complications or 30-day readmissions. Preoperative mean VAS and ODI were 6.2 and 46.7. The postoperative VAS and ODI declined by 3.0 and 22.0 over a mean of 125 days. There were 48 patients with a mean follow-up of 15 months, where the VAS and ODI declined by 2.8 and 22.5, respectively. In this subset, the 23 patients with a spondylolisthesis (all grade 1), were compared to the 25 patients without. The spondylolisthesis group VAS and ODI, preoperatively and postoperatively, declined by 3.3 and 26.1, respectively, while the nonspondylolisthesis group declined by 2.6 and 19.2. These results for each group in this study surpass the standard for a minimal clinically important difference. CONCLUSIONS: Patients with lumbar synovial cysts may safely undergo MIS decompression in an ASC setting, with a low risk of perioperative complications. The reduction in pain and disability is meaningful in the short term and sustained over the next 15 months. The presence of a grade 1 spondylolisthesis did not adversely impact patient outcomes over this time period. For patients undergoing MIS resection of a lumbar synovial cyst, with either the presence or absence of a grade 1 spondylolisthesis, the mandatory inclusion of a concomitant spinal fusion is brought into question. CLINICAL RELEVANCE: This work is among the largest series of synovial cysts published in which the MIS technique is applied. It demonstrates the efficacy of the procedure, along with its safety and appropriateness for performance in an ambulatory care setting. Moreover, it describes the outcomes using the patient-reported outcome measures VAS and ODI. Finally, the long-term outcomes of patients with and without spondylolisthesis are compared, further supporting the position that when performing a decompression of a synovial cyst with an associated grade 1 spondylolisthesis, a concomitant fusion may not always be necessary.

Human-rat integrated microRNAs profiling identified a new neonatal cerebral hypoxic-ischemic pathway melatonin-sensitive.

Neonatal encephalopathy (NE) is a pathological condition affecting long-term neurodevelopmental outcomes. Hypothermia is the only therapeutic option, but does not always improve outcomes; hence, researchers continue to hunt for pharmaceutical compounds. Melatonin treatment has benefitted neonates with hypoxic-ischemic (HI) brain injury. However, unlike animal models that enable the study of the brain and the pathophysiologic cascade, only blood is available from human subjects. Therefore, due to the unavailability of neonatal brain tissue, assumptions about the pathophysiology in pathways and cascades are made in human subjects with NE. We analyzed animal and human specimens to improve our understanding of the pathophysiology in human neonates. A neonate with NE who underwent hypothermia and enrolled in a melatonin pharmacokinetic study was compared to HI rats treated/untreated with melatonin. MicroRNA (miRNA) analyses provided profiles of the neonate's plasma, rat plasma, and rat brain cortexes. We compared these profiles through a bioinformatics tool, identifying Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways common to HI brain injury and melatonin treatment. After evaluating the resulting pathways and the literature, to validate the method, the key proteins expressed in HI brain injury were investigated using cerebral cortexes. The upregulated miRNAs in human neonate and rat plasma helped identify two KEGG pathways, glioma and long-term potentiation, common to HI injury and melatonin treatment. A unified neonatal cerebral melatonin-sensitive HI pathway was designed and validated by assessing the expression of protein kinase Cα (PKCα), phospho (p)-Akt, and p-ERK proteins in rat brain cortexes. PKCα increased in HI-injured rats and further increased with melatonin. p-Akt and p-ERK returned phosphorylated to their basal level with melatonin treatment after HI injury. The bioinformatics analyses validated by key protein expression identified pathways common to HI brain injury and melatonin treatment. This approach helped complete pathways in neonates with NE by integrating information from animal models of HI brain injury.

Peptide Model of the Mutant Proinsulin Syndrome. II. Nascent Structure and Biological Implications.

Toxic misfolding of proinsulin variants in ß-cells defines a monogenic diabetes syndrome, designated mutant INS-gene induced diabetes of the young (MIDY). In our first study (previous article in this issue), we described a one-disulfide peptide model of a proinsulin folding intermediate and its use to study such variants. The mutations (LeuB15→Pro, LeuA16→Pro, and PheB24→Ser) probe residues conserved among vertebrate insulins. In this companion study, we describe 1H and 1H-13C NMR studies of the peptides; key NMR resonance assignments were verified by synthetic 13C-labeling. Parent spectra retain nativelike features in the neighborhood of the single disulfide bridge (cystine B19-A20), including secondary NMR chemical shifts and nonlocal nuclear Overhauser effects. This partial fold engages wild-type side chains LeuB15, LeuA16 and PheB24 at the nexus of nativelike α-helices α1 and α3 (as defined in native proinsulin) and flanking ß-strand (residues B24-B26). The variant peptides exhibit successive structural perturbations in order: parent (most organized) > SerB24 >> ProA16 > ProB15 (least organized). The same order pertains to (a) overall α-helix content as probed by circular dichroism, (b) synthetic yields of corresponding three-disulfide insulin analogs, and (c) ER stress induced in cell culture by corresponding mutant proinsulins. These findings suggest that this and related peptide models will provide a general platform for classification of MIDY mutations based on molecular mechanisms by which nascent disulfide pairing is impaired. We propose that the syndrome's variable phenotypic spectrum-onsets ranging from the neonatal period to later in childhood or adolescence-reflects structural features of respective folding intermediates.

Peptide Model of the Mutant Proinsulin Syndrome. I. Design and Clinical Correlation.

The mutant proinsulin syndrome is a monogenic cause of diabetes mellitus due to toxic misfolding of insulin's biosynthetic precursor. Also designated mutant INS-gene induced diabetes of the young (MIDY), this syndrome defines molecular determinants of foldability in the endoplasmic reticulum (ER) of ß-cells. Here, we describe a peptide model of a key proinsulin folding intermediate and variants containing representative clinical mutations; the latter perturb invariant core sites in native proinsulin (LeuB15→Pro, LeuA16→Pro, and PheB24→Ser). The studies exploited a 49-residue single-chain synthetic precursor (designated DesDi), previously shown to optimize in vitro efficiency of disulfide pairing. Parent and variant peptides contain a single disulfide bridge (cystine B19-A20) to provide a model of proinsulin's first oxidative folding intermediate. The peptides were characterized by circular dichroism and redox stability in relation to effects of the mutations on (a) in vitro foldability of the corresponding insulin analogs and (b) ER stress induced in cell culture on expression of the corresponding variant proinsulins. Striking correlations were observed between peptide biophysical properties, degree of ER stress and age of diabetes onset (neonatal or adolescent). Our findings suggest that age of onset reflects the extent to which nascent structure is destabilized in proinsulin's putative folding nucleus. We envisage that such peptide models will enable high-resolution structural studies of key folding determinants and in turn permit molecular dissection of phenotype-genotype relationships in this monogenic diabetes syndrome. Our companion study (next article in this issue) employs two-dimensional heteronuclear NMR spectroscopy to define site-specific perturbations in the variant peptides.

Diabetes-Associated Mutations in Proinsulin Provide a "Molecular Rheostat" of Nascent Foldability.

PURPOSE OF REVIEW: Diabetes mellitus (DM) due to toxic misfolding of proinsulin variants provides a monogenic model of endoplasmic reticulum (ER) stress. The mutant proinsulin syndrome (also designated MIDY; Mutant INS-gene-induced Diabetes of Youth or Maturity-onset diabetes of the young 10 (MODY10)) ordinarily presents as permanent neonatal-onset DM, but specific amino-acid substitutions may also present later in childhood or adolescence. This review highlights structural mechanisms of proinsulin folding as inferred from phenotype-genotype relationships. RECENT FINDINGS: MIDY mutations most commonly add or remove a cysteine, leading to a variant polypeptide containing an odd number of thiol groups. Such variants are associated with aberrant intermolecular disulfide pairing, ER stress, and neonatal ß-cell dysfunction. Non-cysteine-related (NCR) mutations (occurring in both the B and A domains of proinsulin) define distinct determinants of foldability and vary in severity. The range of ages of onset, therefore, reflects a "molecular rheostat" connecting protein biophysics to quality-control ER checkpoints. Because in most mammalian cell lines even wild-type proinsulin exhibits limited folding efficiency, molecular barriers to folding uncovered by NCR MIDY mutations may pertain to ß-cell dysfunction in non-syndromic type 2 DM due to INS-gene overexpression in the face of peripheral insulin resistance. Recent studies of MIDY mutations and related NCR variants, combining molecular and cell-based approaches, suggest that proinsulin has evolved at the edge of non-foldability. Chemical protein synthesis promises to enable comparative studies of "non-foldable" proinsulin variants to define key steps in wild-type biosynthesis. Such studies may create opportunities for novel therapeutic approaches to non-syndromic type 2 DM.

Neuronal exosome proteins: novel biomarkers for predicting neonatal response to therapeutic hypothermia.

OBJECTIVE: Central nervous system (CNS) derived exosomes can be purified from peripheral blood and have been used widely in adult neurological disease. Application to neonatal neurological disease deserves investigation in the setting of hypoxic-ischaemic encephalopathy (HIE). DESIGN: Observational cohort. SETTING: Level III neonatal intensive care unit. PARTICIPANTS: Term/near-term neonates undergoing therapeutic hypothermia (TH) for HIE. INTERVENTIONS: Blood samples were collected at 0-6, 12, 24, 48 and 96 hours of life. MAIN OUTCOMES AND MEASURES: CNS exosomes were purified from serum using previously described methods. Biomarker protein levels were quantified using standard ELISA methods and normalised to exosome marker CD-81. The slope of change for biomarker levels was calculated for each time interval. Our primary outcome was MRI basal ganglia/watershed score of ≥3. RESULTS: 26 subjects were included (umbilical artery pH range 6.6-7.29; 35% seizures). An increasing MRI injury score was significantly associated with decreasing levels of synaptopodin between 0-6 and 12 hours (p=0.03) and increasing levels of lipocalin-2 (NGAL) between 12 and 48 hours (p<0.0001). Neuronal pentraxin was not significant. The negative predictive values for increasing synaptopodin and decreasing NGAL was 70.0% and 90.9%, respectively. CONCLUSIONS AND RELEVANCE: Our results indicate that CNS exosome cargo has the potential to act as biomarkers of the severity of brain injury and response to TH as well as quantify pharmacological response to neuroactive therapeutic/adjuvant agents. Rigorous prospective trials are critical to evaluate potential clinical use of exosome biomarkers.

Neonatal Transplant in Hypoxic Injury.

Even with therapeutic hypothermia as standard of care, hypoxic-ischemic encephalopathy in neonates often causes long-term disabilities. Stem cell therapy may be a successful treatment for HIE both in the acute and chronic time periods post-injury. Neurogenic astrocytes with characteristics of neural stem cells can be cultured as adherent monolayers and be induced to generate neuronal progeny in vitro and in vivo following reintroduction into the neural stem cell niche of both neonatal and adult hosts. Thus, these neurogenic astrocytes represent promising candidates for cell replacement therapy in HIE. Such an approach requires optimized cell cultivation protocols as well as extensive testing of donor cells to assess their capacity for engraftment, survival, and integration in the HIE animal models. In this chapter, we will describe methods of generating the HIE model, generating and culturing monolayer neurogenic astrocytes, and transplanting these cells into HIE animal models.

Dual trocar laparoscopy improves reduced-port surgery of the distal pancreas.

BACKGROUND: The technical feasibility of transumbilical single-incision surgery (SIL) for pancreatic resections has been demonstrated. However, this technique is hampered by the limited degrees of freedom for instrument handling. Dual-incision laparoscopy (DIL) with an additional trocar may simplify dissection and allow drainage. MATERIAL AND METHODS: Between December 2009 and May 2017, 21 patients were treated with SIL (12/2009 to 01/2014) or DIL (02/2014 to 05/2017) pancreatic resection. All data were collected in a database and retrospectively analysed. RESULTS: Demographic parameters of the patients did not differ significantly in the DIL or the SIL group. No conversion to open surgery was required. No intraoperative complication occurred in either group. The surgical difficulty score was significantly higher in the SIL group (4.4 ± 1.56 vs 2.18 ± 1.95; p = .006). Postoperative serum amylase levels were higher (101.9 U/l ± 50.11 vs 48.91 U/l ± 35.20; p = .01) and return to normal levels (6.4 ± 9.66 days vs 2.09 ± 1.98 days; p = .045) was later in the SIL group. Three complications requiring radiological or surgical intervention were witnessed in the SIL group and one complication in the DIL group (p = .42). CONCLUSION: DIL surgery is a safe and feasible alternative to SIL surgery, facilitating key steps of distal pancreatic tail resection.