Rapid intervention team strategy improves intervention quality for patients undergoing hemodialysis with arteriovenous shunt dysfunction or failure.

BACKGROUND: Vascular access dysfunction is a great burden for hemodialysis patients. Early intervention of a dysfunctional arteriovenous shunt is associated with higher technical success and may improve midterm patency. This trial aimed to estimate the feasibility of a new system, the "rapid intervention team" (RIT) strategy. METHODS: We recruited hemodialysis patients who visited our hospital because of arteriovenous shunt dysfunction or failure to undergo an RIT strategy from September 1, 2019, to December 31, 2022. In addition, we included a control group comprising patients who underwent percutaneous intervention for arteriovenous shunt dysfunction or failure before this strategy was implemented from February 1, 2017, to December 31, 2022. Case number, time to intervention, all-cause mortality, cumulative survival rate, and number of patients who required temporary dialysis catheter insertion and recreation were compared between the two groups. The primary endpoints were double-lumen insertion, a composite outcome involving permanent catheter insertion, and the need for recreation. The secondary endpoint was all-cause mortality. RESULTS: We enrolled 1,054 patients, including 544 (51.6%) and 510 (48.4%) in the RIT and control groups, respectively. Even with the COVID-19 pandemic, the number of cases significantly increased after the implementation of the RIT strategy (from 216 in 2019 to 828 in 2022, p for trend <0.001). The RIT group had a shortened time to intervention (p for trend <0.001). The implementation of the RIT strategy was significantly associated with a reduced risk of insertion of a temporary double-lumen catheter and recreation of vascular access (1% vs. 6% and 1% vs. 28%, respectively; both p < 0.01). The cumulative survival rate was not significantly different between the RIT and control groups (p = 0.16). CONCLUSION: The implementation of the RIT strategy improves the quantity and quality of percutaneous transluminal intervention for arteriovenous shunt dysfunction or failure in patients undergoing hemodialysis.

An Overview of Clinical Examinations in the Evaluation and Assessment of Arterial and Venous Insufficiency Wounds.

Arterial and venous insufficiency are two major causes of chronic wounds with different etiology, pathophysiology, and clinical manifestations. With recent advancements in clinical examination, clinicians are able to obtain an accurate diagnosis of the underlying disease, which plays an important role in the treatment planning and management of patients. Arterial ulcers are mainly caused by peripheral artery diseases (PADs), which are traditionally examined by physical examination and non-invasive arterial Doppler studies. However, advanced imaging modalities, such as computed tomography angiography (CTA) and indocyanine green (ICG) angiography, have become important studies as part of a comprehensive diagnostic process. On the other hand, chronic wounds caused by venous insufficiency are mainly evaluated by duplex ultrasonography and venography. Several scoring systems, including Clinical-Etiology-Anatomy-Pathophysiology (CEAP) classification, the Venous Clinical Severity Score (VCSS), the Venous Disability Score, and the Venous Segmental Disease Score (VSDS) are useful in defining disease progression. In this review, we provide a comprehensive overlook of the most widely used and available clinical examinations for arterial and venous insufficiency wounds.

Cognitive rescue in aging through prior training in rats.

Cognitive decline in spatial memory is seen in aging. Understanding affected processes in aging is vital for developing methods to improve wellbeing. Daily memory persistence can be influenced by events around the time of learning or by prior experiences in early life. Fading memories in young can last longer if a novel event is introduced around encoding, a process called behavioral tagging. Based on this principle, we asked what processes are affected in aging and if prior training can rescue them. Two groups of aged rats received training in an appetitive delayed matching-to-place task. One of the groups additionally received prior training of the same task in young and in mid-life, constituting a longitudinal study. The results showed long-term memory decline in late aging without prior training. This would reflect affected encoding and consolidation. On the other hand, short-term memory was preserved and novelty at memory reactivation and reconsolidation enabled memory maintenance in aging. Prior training improved cognition through facilitating task performance, strengthening short-term memory and intermediate memory, and enabling encoding-boosted long-term memory. Implication of these findings in understanding brain mechanisms in cognitive aging and in beneficial effects of prior training is discussed.

Mid-Adulthood Cognitive Training Improves Performance in a Spatial Task but Does Not Ameliorate Hippocampal Pathology in a Mouse Model of Alzheimer's Disease.

BACKGROUND: Prior experience in early life has been shown to improve performance in aging and mice with Alzheimer's disease (AD) pathology. However, whether cognitive training at a later life stage would benefit subsequent cognition and reduce pathology in AD mice needs to be better understood. OBJECTIVE: This study aimed to verify if behavioral training in mid-adulthood would improve subsequent cognition and reduce AD pathology and astrogliosis. METHODS: Mixed-sex APP/PS1 and wildtype littermate mice received a battery of behavioral training, composed of spontaneous alternation in the Y-maze, novel object recognition and location tasks, and spatial training in the water maze, or handling only at 7 months of age. The impact of AD genotype and prior training on subsequent learning and memory of aforementioned tasks were assessed at 9 months. RESULTS: APP/PS1 mice made more errors than wildtype littermates in the radial-arm water maze (RAWM) task. Prior training prevented this impairment in APP/PS1 mice. Prior training also contributed to better efficiency in finding the escape platform in both APP/PS1 mice and wildtype littermates. Short-term and long-term memory of this RAWM task, of a reversal task, and of a transfer task were comparable among APP/PS1 and wildtype mice, with or without prior training. Amyloid pathology and astrogliosis in the hippocampus were also comparable between the APP/PS1 groups. CONCLUSION: These data suggest that cognitive training in mid-adulthood improves subsequent accuracy in AD mice and efficiency in all mice in the spatial task. Cognitive training in mid-adulthood provides no clear benefit on memory or on amyloid pathology in midlife.

Impairment in novelty-promoted memory via behavioral tagging and capture before apparent memory loss in a knock-in model of Alzheimer's disease.

Alzheimer's disease (AD) is associated with cognitive impairments and age-dependent memory deficits which have been studied using genetic models of AD. Whether the processes for modulating memory persistence are more vulnerable to the influence of amyloid pathology than the encoding and consolidation of the memory remains unclear. Here, we investigated whether early amyloid pathology would affect peri-learning novelty in promoting memory, through a process called behavioral tagging and capture (BTC). AppNL-G-F/NL-G-F mice and wild-type littermates were trained in an appetitive delayed matching-to-place (ADMP) task which allows for the assessment of peri-learning novelty in facilitating memory. The results show that novelty enabled intermediate-term memory in wild-type mice, but not in AppNL-G-F/NL-G-F mice in adulthood. This effect preceded spatial memory impairment in the ADMP task seen in middle age. Other memory tests in the Barnes maze, Y-maze, novel object or location recognition tasks remained intact. Together, memory modulation through BTC is impaired before apparent deficits in learning and memory. Relevant biological mechanisms underlying BTC and the implication in AD are discussed.

Lose the fear and boost the everyday memory through memory destabilisation and reconsolidation.

This review starts with a brief description of key findings from Nader et al. (2000) which stimulate vibrant research of memory reconsolidation in the new millennium. It then zooms in to two aspects of the process that have important implications on whether a memory is susceptible to reconsolidation interference. First, memory strength contributes to a boundary condition on reconsolidation. The relevant receptor and circuit mechanisms are reviewed. Second, reactivation procedures affect memory destabilisation and memory susceptibility to reconsolidation interference. Recent null findings are briefly mentioned. Finally, it covers current discoveries of 'tagging along' reconsolidation to boost memory persistence. This review primarily focuses on evidence from fear conditioning paradigms, as interfering reconsolidation of fear memory paves ways for treating post-traumatic stress disorder (PTSD). Hippocampal-dependent spatial memories and reconsolidation are then discussed, as this approach provides crucial implications in boosting everyday memory persistence and insights on improving cognitive functions in aging.

Behavioral and Cellular Tagging in Young and in Early Cognitive Aging.

The ability to maintain relevant information on a daily basis is negatively impacted by aging. However, the neuronal mechanism manifesting memory persistence in young animals and memory decline in early aging is not fully understood. A novel event, when introduced around encoding of an everyday memory task, can facilitate memory persistence in young age but not in early aging. Here, we investigated in male rats how sub-regions of the hippocampus are involved in memory representation in behavioral tagging and how early aging affects such representation by combining behavioral training in appetitive delayed-matching-to-place tasks with the "cellular compartment analysis of temporal activity by fluorescence in situ hybridization" technique. We show that neuronal assemblies activated by memory encoding were also partially activated by novelty, particularly in the distal CA1 and proximal CA3 subregions in young male rats. In early aging, both encoding- and novelty-triggered neuronal populations were significantly reduced with a more profound effect in encoding neurons. Thus, memory persistence through novelty facilitation engages overlapping hippocampal assemblies as a key cellular signature, and cognitive aging is associated with underlying reduction in neuronal activation.

Cu(II) and Au(III) recovery with electrospun lignosulfonate CO2-activated carbon fiber.

The objectives of this study were twofold: developing lignosulfonate activated carbon fibers (LACFs) and determining the corresponding metal recovery mechanisms with batch experiments and non-linear modeling. LACFs were developed through electrospinning, followed by CO2-based physical activation. Physical and chemical characterizations revealed that the LACF sample that was activated for 60 min exhibited a higher specific surface area (376.54 m2/g), larger total pore volume (0.30 cm3/g), higher micropore ratio (32%), and more acidic and sulfur functional groups than did the other samples. Cu(II) and Au(III) adsorption behaviors on the LACF could be described with the Freundlich and Langmuir model, respectively. Both systems consist of physisorption and chemisorption, and the mechanisms include electrostatic forces, Van der Walls forces, cation exchange, surface complexation. In particular, Au(III) adsorption was faster, and LACF-Au bonds were stronger due to the additional microprecipitation. Furthermore, the LACF sample could regenerate after three adsorption-desorption cycles. Overall, this study provides the foundation for developing physically activated lignosulfonate carbon and its application in recovering valuable metal ions.

How long of a postponement in surgery can a blunt hollow viscus injury patient tolerate? A retrospective study from the National Trauma Data Bank.

BACKGROUND: In the management of patients with blunt abdominal trauma, delayed diagnosis and treatment of hollow viscus injury can occur. We assessed the effect of the time to surgery on the outcomes of blunt hollow viscus injury patients. METHODS: The National Trauma Data Bank was queried from 2012 to 2015 to identify patients with blunt hollow viscus injury for inclusion. Patients with unstable hemodynamics, concomitant intra-abdominal organ injuries, or other severe extra-abdominal injuries were excluded. Inverse probability of treatment weighting and multivariate logistic regression were used to evaluate the effect of the time to surgery on the outcomes. RESULTS: In total, 2,997 patients with blunt hollow viscus injury were studied; the mean time to abdominal surgery was 6.7 hours. Twenty-two hours was selected as a cutoff value for further analyses because of an observed transition zone at that time in the distribution of mortality and severe sepsis rates. After adjustment, patients who underwent surgery within 22 hours had a significantly lower mortality rate (1.2% vs 4.2%), lower sepsis rate (0.9% vs 4.5%), shorter hospital length of stay (8.7 vs 12.0 days), and shorter intensive care unit length of stay (1.4 vs 3.3 days). In patients who underwent surgery within 22 hours, neither mortality nor sepsis were affected significantly by the time to surgery. CONCLUSION: In the management of patients with blunt hollow viscus injury, early surgical treatment is needed. Patients with isolated blunt hollow viscus injury may have a poor outcome if they undergo abdominal surgery more than 22 hours after arrival in the emergency department.

Accuracy of the WSES classification system for pelvic ring disruptions: an international validation study.

BACKGROUND: In 2017, a novel classification for pelvic injuries was established by the World Society of Emergency Surgery (WSES). We validated its effectiveness using nationwide real-world data. The roles of associated vascular injury and open fracture in this system were also evaluated. METHODS: Patients with pelvic fractures in the National Trauma Data Bank 2015 dataset were retrospectively studied. First, the mortality rates were compared by WSES classification. Second, independent predictors of mortality were evaluated using a multivariate logistic regression model. Patients with and without associated vascular injuries and the same hemodynamic and pelvic ring stability statuses were compared. Patients with associated vascular injuries were compared to the proportion of nonsurvivors and survivors with unstable pelvic ring injuries. Third, the outcomes were compared between patients with open pelvic fracture and closed pelvic fracture in the mild, moderate and severe WSES classes. RESULTS: During the 12-month study period, 44,163 blunt pelvic fracture patients were included. The mortality rates were 1.8%, 3.8% and 10.6% for the mild, moderate and severe WSES classes, respectively (p < 0.001). MLR analysis showed that unstable pelvic ring injury did not significantly affect mortality (p = 0.549), whereas open pelvic fracture and associated vascular injury were independent predictors of mortality (odds of mortality: open pelvic fracture 1.630, p < 0.001; associated vascular injury 1.602, p < 0.001). Patients with associated vascular injuries showed that there was no significant difference in the proportion of patients with unstable pelvic ring injuries between survivors and nonsurvivors (37.2% vs. 32.7%, p = 0.323). In all three classes, patients with open pelvic fractures had significantly higher mortality rates and infection rates than patients with closed fractures (mortality rates: minor 3.5% vs. 1.8%, p = 0.009, moderate 11.2% vs. 3.3%, p < 0.001, severe 23.8% vs. 9.8%, p < 0.001; infection rates: minor 3.3% vs. 0.7%, p < 0.001, moderate 6.7% vs. 2.1%, p < 0.001, severe 7.9% vs. 2.8%, p < 0.001). CONCLUSIONS: Based on this nationwide study, the WSES guideline provides an accurate and reproducible classification of pelvic fractures. It is recommended that open/closed fractures and associated vascular injuries be evaluated as supplements of the WSES classification.

Modified Stair-Step Flap With Turnover Flap for Drooling Correction After Lower Lip Composite Defect Reconstruction.

BACKGROUND: Oral commissure and buccal complex defects are commonly seen after cancer ablation. Free flap reconstruction can offer adequate soft tissue volume and outer skin lining. However, oral incompetence often occurs when an oral commissure has defects, particularly when the patient receives postoperative radiotherapy. The purpose of this article was to describe our method of the modified stair-step technique and improve the oral competence. METHODS: This study involves 22 patients who had partial lower lip and/or upper lip defects and underwent flap reconstruction and/or postoperative radiotherapy resulting in oral incontinence. Fourteen patients had been treated with an anterolateral thigh flap, 7 patients had been treated with a radial forearm flap, and 1 patient had been treated with a fibular osteocutaneous flap. Our modified stair-step commissuroplasty was done in all cases, and a debulking procedure was done in each second operation. RESULTS: Acceptable oral continence and contour were achieved in 19 patients. Some patients still had drooling after their second operation, but it was considerably less than before. CONCLUSIONS: This technique is an easy procedure for revision of lower lip deformities after oral commissure reconstruction.

The Benefits of the Supercharged Ileocolic Flap in Patients Who Underwent Total Esophagectomy and Gastrectomy.

BACKGROUND: Patients who undergo total esophagectomy and gastrectomy present a challenging scenario for reconstructive surgeons. Several techniques have been described. However, the best choice is still a matter of debate. We aim to report our experience with the supercharged ileocolic flap, then to compare the long-term functional outcomes in cancer and caustic injury patients. We investigate the safest route of transposition and demonstrate the importance of supercharging the flap. Last, we perform a literature review to compare our results with the ones reported in the literature. METHODS: A total of 36 patients underwent the supercharged ileocolic flap procedure. The details reviewed included the type of defect, flap characteristic, route of transposition, complications, patient survival, and swallowing evaluation. Survival and long-term function preservation were considered as the main outcomes. A secondary end-point was the identification of the safest route of transposition. We extracted the pertinent literature on supercharged bowel flaps from 1995 to July 2020 RESULTS: All flaps survived; only two flaps were partially lost. Thirty-three percent of the cohort experienced postoperative complications; the most common was leakage of the cervical anastomosis (17%), followed by neck wound infection (8%). The 5-year dysphagia-free survival rate was 87% in corrosive injury patients and 78% in cancer patients. The mean time to be free from dysphagia after surgery was 25.12 ± 4.55 months for corrosive patients and 39.56 ± 9.45 months for cancer patients (p = 0.118). The safest route of transposition was retrosternal extra-mediastinal. From the literature review, the data from 11 studies were extracted. CONCLUSION: The supercharged ileocolic flap is a robust option for total esophageal replacement when the stomach is not available and the retrosternal route is the safest for transposition. The functional outcomes are excellent, with acceptable morbidity and a good life expectancy, either in cancer and noncancer patients. Supercharging the flap is recommended.

Comparison of regular- and slope-configured dental implants placed in the edentulous ridge with height discrepancy: A pilot randomized controlled trial.

BACKGROUND/PURPOSE: Edentulous ridges with height discrepancies (RHDs) could jeopardize the outcome of implant placement. This study aimed at evaluating the outcomes of placing regular- and slope-configured implants in RHDs. METHODS: Patients with >1 mm RHDs requesting implant rehabilitation were recruited and randomly assigned to regular- (control) or slope-configured (test) implant treatment using a submerged installation protocol. Thread exposure (TE) and implant stability quotient (ISQ) were evaluated during implant installation (S1) and uncovered surgery (S2), and marginal bone level (MBL) was evaluated after implant installation (T1) and uncovery (T3), and one year after implant placement (T4). Periodontal status and gingival crevicular fluid (GCF) biomarkers of adjacent teeth were evaluated before implant installation (T0), before uncovery (T2), and at T4. Peri-implant clinical status and peri-implant crevicular fluid (PICF) biomarkers of examined implants were evaluated at T4. RESULTS: Nineteen patients with 17 control and 13 test implants were included. All of the implants survived with acceptable peri-implant health, and PICF biomarkers were at equivalent levels as GCF biomarkers of the adjacent teeth at T4. Compared with the control group, the test group showed reduced TE and equivalent ISQ at S1 and S2, and the loss of MBL was reduced at T4. Regarding the adjacent teeth, all periodontal parameters and GCF biomarkers were slightly decreased from T0 to T2, and the reductions in probing pocket depth and clinical attachment level were slightly greater at T4. CONCLUSION: Slope-configured implants maintained the implant-supporting structures and minimally altered periodontal status of the adjacent teeth in RHDs.

Sparse Activity of Hippocampal Adult-Born Neurons during REM Sleep Is Necessary for Memory Consolidation.

The occurrence of dreaming during rapid eye movement (REM) sleep prompts interest in the role of REM sleep in hippocampal-dependent episodic memory. Within the mammalian hippocampus, the dentate gyrus (DG) has the unique characteristic of exhibiting neurogenesis persisting into adulthood. Despite their small numbers and sparse activity, adult-born neurons (ABNs) in the DG play critical roles in memory; however, their memory function during sleep is unknown. Here, we investigate whether young ABN activity contributes to memory consolidation during sleep using Ca2+ imaging in freely moving mice. We found that contextual fear learning recruits a population of young ABNs that are reactivated during subsequent REM sleep against a backdrop of overall reduced ABN activity. Optogenetic silencing of this sparse ABN activity during REM sleep alters the structural remodeling of spines on ABN dendrites and impairs memory consolidation. These findings provide a causal link between ABN activity during REM sleep and memory consolidation.

The striatum, the hippocampus, and short-term memory binding: Volumetric analysis of the subcortical grey matter's role in mild cognitive impairment.

BACKGROUND: Deficits in short-term memory (STM) binding are a distinguishing feature of preclinical stages leading to Alzheimer's disease (AD). However, the neuroanatomical correlates of conjunctive STM binding are largely unexplored. Here we examine the possible association between the volumes of hippocampi, parahippocampal gyri, and grey matter within the subcortical structures - all found to have foci that seemingly correlate with basic daily living activities in AD patients - with cognitive tests related to conjunctive STM binding. MATERIALS AND METHODS: Hippocampal, thalamic, parahippocampal and corpus striatum volumes were semi-automatically quantified in brain magnetic resonance images from 25 cognitively normal people and 21 patients with Mild Cognitive Impairment (MCI) at high risk of AD progression, who undertook a battery of cognitive tests and the short-term memory binding test. Associations were assessed using linear regression models and group differences were assessed using the Mann-Whitney U test. RESULTS: Hippocampal and parahippocampal gyrus volumes differed between MCI and control groups. Although the grey matter volume in the globus pallidus (r = -0.71, p < 0.001) and parahippocampal gyry (r = -0.63, p < 0.05) correlated with a STM binding task in the MCI group, only the former remained associated with STM binding deficits in MCI patients, after correcting for age, gender and years of education (ß = -0.56,P = 0.042) although with borderline significance. CONCLUSIONS: Loss of hippocampal volume plays no role in the processing of STM binding. Structures within the basal ganglia, namely the globus pallidus, could be part of the extrahippocampal network supporting binding. Replication of this study in large samples is now needed.

Synchronous microsurgical anastomosis in complex replantation surgery.

We conducted a retrospective case control study of digital replantations in 16 patients from September 2015 to January 2017. Half of the patients were treated by a synchronous microsurgical technique and the other half underwent conventional micro-anastomoses. The total time for anastomoses, total operation time and survival of digits were the major endpoints in this study. The number of digits replanted and the anastomosis method had significant effects on total anastomosis time. The mean anastomosis time for each digit was 46 min and 70 min in the synchronous and conventional groups, respectively, a 34% reduction in anastomosis time in the synchronous group when compared with the conventional group. Patency rates were 87% (13/15) of all the digits replanted in each group. Level of evidence: IV.

Developing Lignosulfonate-Based Activated Carbon Fibers.

In this study, electrospinning technology, physical activation, and carbonization processing were applied to produce lignosulfonate-based activated carbon fibers. The porous structure of the produced lignosulfonate-based activated carbon fibers primarily contained mesopores and a relatively small amount of micropores. Moreover, insufficient carbonization caused fiber damage during CO2 activation. The weight loss rate and specific surface area increased with increase in carbonization time, and products with carbonization temperatures of 700 °C were of higher quality than those with other temperatures. Moreover, the two-step carbonization process provided fibers with improved quality because of a low weight loss rate, improved processing, and high surface area. Lignosulfonate-based activated carbon fibers can be used as a highly efficient adsorption and filtration material, and further development of its applications would be valuable.

Cortico-hippocampal Schemas Enable NMDAR-Independent Fear Conditioning in Rats.

The neurobiology of memory formation has been studied primarily in experimentally naive animals, but the majority of learning unfolds on a background of prior experience. Considerable evidence now indicates that the brain processes initial and subsequent learning differently. In rodents, a first instance of contextual fear conditioning requires NMDA receptor (NMDAR) activation in the dorsal hippocampus, but subsequent conditioning to another context does not. This shift may result from a change in molecular plasticity mechanisms or in the information required to learn the second task. To clarify how related events are encoded, it is critical to identify which aspect of a first task engages NMDAR-independent learning and the brain regions that maintain this state. Here, we show in rats that the requirement for NMDARs in hippocampus depends neither on prior exposure to context nor footshock alone but rather on the procedural similarity between two conditioning tasks. Importantly, NMDAR-independent learning requires the memory of the first task to remain hippocampus dependent. Furthermore, disrupting memory maintenance in the anterior cingulate cortex after the first task also reinstates NMDAR dependency. These results reveal cortico-hippocampal interactions supporting experience-dependent learning.

Novelty enhances memory persistence and remediates propranolol-induced deficit via reconsolidation.

Memory reactivation has been shown to open a time window for memory modulation. The majority of the methodological or pharmacological approaches target disruption of reconsolidation to weaken aversive memories. However, methods to improve appetitive memory persistence through reconsolidation or to reverse drug-induced reconsolidation impairment are limited. To improve memory persistence, previous studies show that a novel event, introduced around the time of memory encoding, enables the persistence of an otherwise decayed memory. This is mainly through a memory consolidation process. The current study first investigated if a novel event introduced during memory reactivation improves memory persistence through reconsolidation. Using a rodent appetitive spatial paradigm, similar to the human everyday experience of recalling where an item is located, a novel event around memory reactivation facilitated the persistence of spatial memory. This facilitation did not occur when the novel event was omitted and the protein synthesis-dependent reconsolidation was not affected by zif268 anti-sense in the dorsal hippocampus. Furthermore, beta-adrenergic antagonists, propranolol, impaired reconsolidation of appetitive spatial memory and contextual fear conditioning. A novel event after memory reactivation could reverse this impairment due to propranolol. Together, this study provides methods and confirmation for improving memory persistence during memory reactivation and reconsolidation.

High Intracellular Seed Train BiP Levels Correlate With Poor Production Culture Performance in CHO Cells.

Consistent cell culture performance is a prerequisite to ensure product quality consistency and achieve productivity goals for the manufacture of recombinant protein therapeutics, including monoclonal antibodies. Here a peculiar observation is reported where high levels of intracellular BiP in seed train cultures are consistently predictive of poor cell culture performance in the subsequent inoculum and production cultures for a monoclonal antibody produced in CHO cells. This investigation suggests that in this cell line the high intracellular BiP levels in the seed train are triggered by a slightly lower culture pH, which interferes with proper antibody folding and secretion. While the seed train culture does not display any obvious signs of the problem at slightly lower culture pH, inoculum trains, and production cultures sourced from these low pH seed trains display significantly lower cell growth and cell size. High intracellular BiP levels may interfere with UPR signaling, thereby hampering a proper and timely UPR response in the production media. Studies of other problematic cell lines have shown a similar correlation between intracellular BiP accumulation and poor production performance. The authors believe intracellular BiP levels in seed train should hence be low in order to increase the success rate in production.