Spontaneous Migration Research Articles

Spontaneous retrograde urolithiasis migration in a woman: a case report and possible mechanism

Urolithiasis is a condition which is commonly encountered in practice, however retrograde migration of a calculus within the ureter has only recently been documented with few cases reported in the literature. We present the case of a 47-year-old woman presenting with symptomatic urolithiasis confirmed by CT who recovered from her symptoms only for it to be discovered that the calculus had undergone retrograde migration into the renal calyx on a follow up CT examination. We theorise that retrograde urolithiasis migration may be an innate safety mechanism that evolved to prevent complications and/or death from urolithiasis impaction by attempting to return a migrated lithiasis to the renal calyx.

Pleural effusion and respiratory compromise from spontaneous migration of a ventriculoperitoneal shunt catheter in a patient with normal-pressure hydrocephalus

Background: Ventriculoperitoneal shunt (VPS) insertion is one of the most common neurosurgical procedures done around the world to treat hydrocephalus. The occurrence of spontaneous migration of the peritoneal shunt catheter into the thoracic cavity is a very rare complication; we report here case number 27 of respiratory complications of a VPS in a patient with normal-pressure hydrocephalus (NPH).Case Description: A 76-year-old woman with Alzheimer’s disease and anosognosia was diagnosed idiopathic NPH treated surgically with a VPS. Pleural effusion and pulmonary complications occurred 4 weeks after the insertion of the shunt due to the spontaneous migration of the peritoneal catheter of the VPS into the thoracic cavity. The hydrothorax of cerebrospinal fluid was drained and the distal catheter was removed and replaced. The patient made an uneventful recovery.Conclusion: Due to the rarity of this complication, there are no standard corrective procedures. Some of the methods used to diagnose and successfully treat this rare complication of the VPS are presented.

Spontaneous Migration of Intraperitoneal Mesh into Rectum following Ventral Hernia Repair

AbstractWe present a rare case of spontaneous migration of mesh into the anal canal 6 years after laparoscopic intraperitoneal mesh placement for ventral hernia. Mesh migration is an uncommon phenomenon with an unclear etiology and is probably attributed to prolonged subclinical infection or foreign body reaction. This is probably the first case in literature to our knowledge, where composite mesh was migrated into the anal canal after a laparoscopic intraperitoneal mesh placement and was retrieved in a natural way without surgical intervention.

Agricultural Origins of Corporate Pro-environmental Behavior

Environmental protection, as a topic of continuous social concern, has put forward higher requirements on enterprises. Using the rice theory, we develop an agricultural perspective on the relationship between geographical distribution of rice cultivation and corporate pro-environmental behavior. Based on the data of listed companies from 2010 to 2019 in China, our results indicate that rice culture in the external environment which the company embedded in has a positive association with corporate reactive pro-environmental behavior. while rice culture in the internal values which CEO provided with is positively related to the corporate proactive pro-environmental behavior. Additional analyses suggest that mandatory green development policy and spontaneous migration are two moderators through which rice culture affects corporate pro-environmental behavior. This study not only sheds light on the agricultural drivers behind corporate pro-environmental behavior and extends the theoretical understanding of how macro cultural factors influence corporate strategic decisions, but also offers implications for government and enterprises to better supervise and improve green management.

Endoscopic Stenting in Crohn's Disease-related Strictures: A Systematic Review and Meta-analysis of Outcomes.

Crohn's disease (CD) is a chronic progressive condition that is complicated by intestinal or colonic stricture in nearly 30% of cases within 10 years of the initial diagnosis. Endoscopic balloon dilation (EBD) is associated with a risk of perforations and recurrence rates of up to 60% at 5 years. Endoscopic stenting has been used as an alternative to EBD, but data on its safety and efficacy are limited. We conducted a systematic review and meta-analysis to assess the outcomes of endoscopic stenting in CD-related strictures. A systematic and detailed search was run in January 2022 with the assistance of a medical librarian for studies reporting on outcomes of endoscopic stenting in CD-related strictures. Meta-analysis was performed using random-effects model, and results were expressed in terms of pooled proportions along with relevant 95% confidence intervals (CIs). Nine studies with 163 patients were included in the final analysis. Self-expanding metal stents (SEMS) including both partial and fully covered were used in 7 studies, whereas biodegradable stents were used in 2 studies. Pooled rate of clinical success and technical success was 60.9% (95% CI, 51.6-69.5; I2 = 13%) and 93% (95% CI, 87.3-96.3; I2 = 0%), respectively. Repeat stenting was needed in 9.6% of patients (95% CI, 5.3-16.7; I2 = 0%), whereas pooled rate of spontaneous stent migration was 43.9% (95% CI, 11.4-82.7; I2 = 88%). Pooled incidence of overall adverse events, proximal stent migration, perforation, and abdominal pain were 15.7%, 6.4%, 2.7%, and 17.9%, respectively. Mean follow-up period ranged from 3 months to 69 months. Endoscopic stenting in CD-related strictures is a safe technique that can be performed with technical ease, albeit with a limited clinical success. Postprocedure abdominal pain and proximal stent migration are some of the common adverse events reported.

015 Optimal methods for human skin T-cell analysis

Background:Tissue-resident memory T (TRM) cells reside in peripheral tissues, including the skin. In humans, TRM cells exist in both the epidermis and dermis, but their composition, phenotype, and function are not fully elucidated. To analyze T cells in both the epidermis and dermis, the skin needs to be incubated with Dispase II to separate the two layers. The next step varies among researchers; the subsequent enzymatic digestion of epidermis and dermis is popular, whereas the spontaneous migration method can also be done.

Unintentional Recovery of Parasitic Diversity Following Restoration of Red Deer (Cervus elaphus) in North-Western Italy.

Simple SummaryIn the early sixties, free ranging red deer (Cervus elaphus, L.) were absent in Piedmont. Human-driven translocations and spontaneous migration of red deer from Switzerland and France resulted in the successful redistribution of this wild ungulate. In parallel, host-specific parasites harbored by red deer populations disappeared in the same area until the restoration of red deer in north-western Italy. The parasitic community has been enriched with at least two species-specific taxa, Onchocerca jakutensis and Pharyngomyia picta, suggesting that the recovery of parasitic biodiversity could be included amongst future conservation goals of this intensively managed game.Red deer (Cervus elaphus) populations in north-western Italy have been remodeled in recent decades. Multiple translocations and the spontaneous migration from Switzerland and France resulted in the successful redistribution of the red deer after human-driven extirpation during the 18th century. The scarcely diverse parasitic community harbored by these cervids has been enriched with two species-specific taxa, Onchocerca jakutensis and Phayigomyia picta, suggesting that the recovery of parasitic biodiversity could be included amongst future conservation goals of this intensively managed game. Nodular onchocercosis was reported in three red deer populations since 2011, while nasal bots were reported since 2018. Hypoderma spp. larvae were identified for the first time in 1989, then a second record was made in 2014 in the province of Biella, where a yearling male in poor condition infested with Hypoderma diana was observed. In the perspective that the restoration of species-specific parasite communities of native mammals in Europe is increasingly perceived as a conservation target, with similar dignity as the conservation of their hosts, baseline data presented in this communication may give new insights for future parasite conservation efforts.

EUS-directed transgastric interventions in Roux-en-Y gastric bypass anatomy: a multicenter experience

Placement of a lumen-apposing metal stent (LAMS) between the gastric pouch and the excluded stomach allows for EUS-guided transgastric interventions (EDGIs) in patients with Roux-en-Y gastric bypass (RYGB). Although EUS-guided transgastric ERCP (EDGE) outcomes have been reported, data are scant on other endoscopic interventions. We aimed to evaluate the outcomes and safety of EDGIs. This retrospective study involved 9 centers (United States, 8; Europe, 1) and included patients with RYGB who underwent EDGIs between June 2015 and September 2021. The primary outcome was the technical success of EDGIs. Secondary outcomes were adverse events (AEs), length of hospital stay, and fistula follow-up and management. Fifty-four EDGI procedures were performed in 47 patients (mean age, 61 years; 72% women), most commonly for the evaluation of a pancreatic mass (n= 16) and management of pancreatic fluid collections (n= 10). A 20-mm LAMS was used in 26 patients and a 15-mm LAMS in 21, creating a gastrogastrostomy in 37 patients and jejunogastrostomy in 10. Most patients (n= 30, 64%) underwent a dual-session EDGI, with a median interval of 17 days between the 2 procedures. Single-session EDGI was performed in 17 patients, of whom 10 (59%) had anchoring of the LAMS. The most common interventions were diagnostic EUS (with or without FNA or fine-needle biopsy sampling; n= 28) and EUS-guided cystgastrostomy (n= 8). The mean procedural time was 97.6 ± 78.9 minutes. Technical success was achieved in 52 patients (96%). AEs occurred in 5 patients (10.6%), of which only 1 AE (2.1%) was graded as severe. Intraprocedural LAMS migration was the most common AE, occurring in 3 patients (6.4%), whereas delayed spontaneous LAMS migration occurred in 2 (4.3%). Four of the 5 LAMS migration events were managed endoscopically, and 1 required surgical repair. LAMS anchoring was found to be protective against LAMS migration (P= .001). The median duration of hospital stay was 2.1 ± 3.7 days. Of the 17 patients who underwent objective fistula assessment endoscopically or radiologically after LAMS removal, 2 (11.7%) were found to have persistent fistulas. In 1 case the fistula was intentionally left open to assist with weight gain. The other fistula was successfully closed endoscopically. EDGI is effective and safe for the diagnosis and management of pancreaticobiliary and foregut disorders in RYGB patients. It is associated with high rates of technical success and low rates of severe AEs. LAMS migration is the most common AE with evidence that anchoring can be protective against its occurrence. Persistent fistulas may occur, but endoscopic closure seems to be effective.

A Two-Stage Bedside Intubation Method to Improve Success Rate of Post-pyloric Placement of Spiral Nasoenteric Tubes in Critically Ill Patients: A Multi-Center, Prospective Study.

BackgroundsProkinetic agents could improve the success rate of post-pyloric placement of self-propelled spiral nasoenteric tubes (NETs), and bedside blind technique might apply as a rescue therapy subsequent to spontaneous transpyloric migration failure. The objective of this study was to investigated the validity and safety of these two bedside intubation methods as a sequential procedure for post-pyloric placement of spiral NETs in critically ill patients.MethodsThe multicenter, prospective study was conducted in intensive care units of four tertiary hospitals (June 2020 to January 2021). Eligible patients received self-propelled spiral NET placements, promoted by prokinetic agents (Stage 1). An abdominal X-ray performed 24 h post-intubation confirmed the position of the tube tip. Patients with a failed transpyloric migration entered Stage 2, where beside blind intubation was conducted (reconfirmed by X-ray). The primary end point was the overall success rate of post-pyloric placement.ResultsThe overall success rate of post-pyloric placement of the spiral NET was 91.1% (73.4% in the third portion of the duodenum [D3] or beyond). The total adverse event rate was 21.0%, without any serious adverse events. In Stage 1, 55.6% of participants achieved transpyloric migration, of these, 44.4% migrated to D3 or beyond. The median time from decision to intubate to the initiation of enteral nutrition (EN) was 25 h. In Stage 2, 83.0% of patients had successful post-pyloric intubation (67.9% in D3 or beyond). The median time from decision to EN initiation after the two-stage process was 36 h.ConclusionsProkinetic agents-assisted self-propelled intubation and remedial bedside blind technique as a sequential procedure for post-pyloric placement of spiral NETs were effective and safe, and this two-stage process did not affect the implementation of early EN in critically ill patients.Trial RegistrationChinese Clinical Trial Registry, ChiCTR1900026381. Registered on 6 October 2019.

The missing chemo port catheter fragment

The totally implantable venous access ports (TIVAP) is commonly indicated for oncology patients for administration of chemotherapy, total parenteral nutrition and long-term intravenous therapy. It is associated with some complications, which might cause significant morbidity or mortality. Spontaneous fracture and migration of the catheter is a rare but potentially serious complication. We presented a 22 year-old gentleman with diffuse large B cell lymphoma and had TIVAP done. It was complicated with the fractured and embolized catheter fragment. Endovascular retrieval was successfully performed and patient was subsequently discharged well.

The Effects of Viscoelasticity on Droplet Migration on Surfaces with Wettability Gradients.

A finite-volume method based on the OpenFOAM is used to numerically study the factors affecting the migration of viscoelastic droplets on rigid surfaces with wettability gradients. Parameters investigated include droplet size, relaxation time, solvent viscosity, and polymer viscosity of the liquid comprising droplets. The wettability gradient is imposed numerically by assuming a linear change in the contact angle along the substrate. As reported previously for Newtonian droplets, the wettability gradient induces spontaneous migration from hydrophobic to hydrophilic region on the substrate. The migration of viscoelastic droplets reveals the increase in the migration speed and distance with the increase in the Weissenberg number. The increase in droplet size also shows the increase in both the migration speed and distance. The increase in polymer viscosity exhibits the increase in migration speed but the decrease in migration distance.

Polysialic Acid Self-assembled Nanocomplexes for Neutrophil-Based Immunotherapy to Suppress Lung Metastasis of Breast Cancer.

The role of neutrophils in tumor metastasis has recently attracted widespread interest. Neutrophils are the most abundant immune cells in human peripheral blood, and large numbers can spontaneously migrate to metastatic sites, where they form an immunosuppressive microenvironment. Polysialic acid (PSA) can target peripheral blood neutrophils (PBNs) mediated by L-selectin, and abemaciclib (ABE) and mitoxantrone (MIT) can treat immunosuppressive microenvironments. Here, we aimed to inhibit lung metastasis of breast cancer and improve chemoimmunotherapy by designing a PSA-modified ABE and MIT co-delivery system (AM-polyion complex (PIC)) to target PBNs in mice with metastatic tumors. We found that through electrostatic interactions between the strong negative charge of PSA and the positive charge of the drug can form stable nanocomplexes and that spontaneous migration of neutrophils can mediate the aggregation of these complexes in the lungs, induce antimetastatic immune responses, enhance the effectiveness of cytotoxic T lymphocytes (CTLs), and inhibit regulatory T cell (Treg) proliferation in vivo and in vitro. Pharmacodynamic results suggested that neutrophil-mediated AM-PIC chemoimmunotherapy inhibited tumor metastasis in mice with lung metastasis of 4T1 breast cancer. Overall, PSA-modified nanocomplexes offer promising neutrophil-mediated, targeted drug delivery systems to treat lung metastasis of breast cancer.

Revisiting the Experimental Methods for Human Skin T-Cell Analysis

Tissue-resident memory T cells exist in both the epidermis and the dermis in human skin. To analyze these cells, the skin needs to be incubated with dispase II to separate the two layers, that is, the epidermis and the dermis. The next step varies among researchers; the subsequent enzymatic digestion of the two layers is popular, whereas the spontaneous migration method can also be done. Scraping of these layers to yield skin T cells may reduce antigen modulation. This study aimed to determine each method’s limitations. Dispase II incubation itself cleaves T-cell antigens. Therefore, further enzymatic digestion with collagenases strongly cleaves antigens. The scraping method yields skin T cells that are affected by dispase II as it is. However, skin T-cell yield is low. The spontaneous migration method recovers and/or upregulates antigens with T-cell activation and loses ∼20% of T cells in the floating sheets. However, there was no prominent bias regarding CD103 expression between emigrants and the remaining T cells in the sheets. There were 104 and 105 CD3+ T cells per 1 cm2 of the epidermis and upper dermis, respectively. Collectively, each method has strengths and limitations to analyze both the epidermal and dermal T cells.

Hydrogen spillover assisted by oxygenate molecules over nonreducible oxides

Spontaneous migration of atomic hydrogen species from metal particles to the surface of their support, known as hydrogen spillover, has been claimed to play a major role in catalytic processes involving hydrogen. While this phenomenon is well established on reducible oxide supports, its realization on much more commonly used non-reducible oxides is still challenged. Here we present a general strategy to enable effective hydrogen spillover over non-reducible SiO2 with aid of gaseous organic molecules containing a carbonyl group. By using hierarchically-porous-SiO2-supported bimetallic Pt-Fe catalysts with Pt nanoparticles exclusively deposited into the micropores, we demonstrate that activated hydrogen species generated on the Pt sites within the micropores can be readily transported by these oxygenate molecules to Fe sites located in macropores, leading to significantly accelerated hydrodeoxygenation rates on the latter sites. This finding provides a molecule-assisted approach to the rational design and optimization of multifunctional heterogeneous catalysts, reminiscent of the role of molecular coenzymes in bio-catalysis.

Spontaneous migration of retained intracranial missiles: experience with 16 cases.

Spontaneous migration of retained intracranial missiles is uncommon but a potentially serious phenomenon. Our objective is to increase awareness of the risk of spontaneous migration of retained intracranial missiles by reporting our case series of 16 patients. We performed a retrospective single-center study on patients treated for intracranial missile injuries between 2000 and 2010 in Palestine with a particular focus on the migration of retained intracranial missiles. Detailed analyses were made of patients' age, sex, type of injurious agents (metallic bullets/rubber bullets/metallic shrapnel from bomb explosion), initial missile position, site to where the missile migrated, radiological and neurological manifestations, complications, treatment modalities (surgery vs. conservative) and functional outcome by Glasgow outcome scale-extended (GOSE) classification at last follow-up. In a cohort of 190 patients with retained intracranial missiles, we identified 16 (8.4%) patients with spontaneous migration. Patients' age ranged from 10 to 30years (mean: 18.9 ± 6.4years). There were only 2 female patients. The missiles that migrated intracranially were metallic bullets (n = 10), rubber bullets (n = 3), and metallic shrapnel from a bomb explosion (n = 3). Among the 16 patients, 10 patients experienced symptoms due to missile migration and were treated surgically, while six patients did not develop new symptoms after missile migration and were managed conservatively. In our case series, 16/190 (8.4%) patients with retained intracranial missiles developed spontaneous migration. Neurosurgeons performing delayed surgery on patients with retained intracranial missiles should be aware of the risk of spontaneous migration and verify the location of the missile after positioning the patient for surgery.

Strategy for Fabricating Ultrathin Au Film Electrodes with Ultralow Optoelectrical Losses and High Stability.

A vital objective in the wetting of Au deposited on chemically heterogeneous oxides is to synthesize a completely continuous, highly crystalline, ultrathin-layered geometry with minimized electrical and optical losses. However, no effective solution has been proposed for synthesizing an ideal Au-layered structure. This study presents evidence for the effectiveness of atomic oxygen-mediated growth of such an ideal Au layer by improving Au wetting on ZnO substrates with a substantial reduction in free energy. The unexpected outcome of the atomic oxygen-mediated Au growth can be attributed to the unconventional segregation and incorporation of atomic oxygen along the outermost boundaries of Au nanostructures evolving in the clustering and layering stages. Moreover, the experimental and numerical investigations revealed the spontaneous migration of atomic oxygen from an interstitial oxygen surplus ZnO bulk to the Au-ZnO interface, as well as the segregation (float-out) of the atomic oxygen toward the top Au surfaces. Thus, the implementation of a 4-nm-thick, two-dimensional, quasi-single-crystalline Au layer with a nearly complete crystalline realignment at a mild temperature (570 K) enabled exceptional optoelectrical performance with record-low resistivity (<7.5 × 10-8 Ω·m) and minimal optical loss (∼3.5%) at a wavelength of 700 nm.

Marangoni effect and its potential utilization in supporting lunar habitats and other extraterrestrial endeavors

Tears of wine is a phenomenon frequently observed as a ring of wine formed near the top of the glass generates droplets that fall back into the wine. This phenomenon can be explained by the Marangoni effect driven by the surface tension created via gradient on concentration and temperature along the interface between two phases. Besides being observed while drinking wine, the Marangoni effect is crucial for welding metals, manufacturing integrated circuits, and growing crystals. This paper aims to establish that the Marangoni effect has the potential to be also crucial supporting lunar habitats and other extraterrestrial endeavors, as vacuum and reduced gravity are expected to augment the Marangoni effect on extraterrestrial molten soil leading to sustainable extraterrestrial in-situ resources utilization (ISRU). The authors conducted a Marangoni effect assessment on molten lunar regolith via JSC-1A lunar regolith simulant under vacuum yielding a spontaneous upwards migration of a uniform molten thin-film front as well as at bulk scale that climbed the crucible wall covering the entire wall’s surface and reaching the crucible’s top end. This unique formation and self-migration of a thin-film front could enable key ISRU processes such as, thin-film coating, crystal growth, and feedstock generation for additive 3D printing. Further assessment on higher-temperature vacuum-driven decomposition of the uniform thin-film front as it climbed the crucible’s wall revealed a significant decomposition of various simulant’s metal-oxide components into their respective oxygen and metal elements strengthening the feasibility of extraterrestrial generation and fractional separation of oxygen and metals/alloys with none or minimal need for terrestrial precursors. These two-coupled phenomena, spontaneous material transportation at both thin-film and bulk scales via Marangoni effect and vacuum-driven decomposition open novel pathways in extraterrestrial mining and manufacturing. Future extraterrestrial mining will require an operational approach completely different from the terrestrial one that heavily relies on not only mechanical excavation and transportation but also on a stand-alone refinery process to extract the mineral components. In this paper, the authors propose an extraterrestrial all-in-one mining process in which the Marangoni effect would allow non-mechanical transportation of the extraterrestrial mineral to feed an also in-situ pyrolysis-based refinery unit.

Efficient regeneration of retired LiFePO4 cathode by combining spontaneous and electrically driven processes

Based on a combination of spontaneous lithium migration and targeted electrically-driven lithiation, a two-step resting-output current process was conducted to directly regenerate retired LiFePO4 cathode, which can reduce energy consumption and environmental pollution.

Gastrointestinal: Spontaneous colonic migration of NAGI stent causing luminal obstruction: An unusual complication of EUS-guided drainage of WON.

Gastrointestinal: Spontaneous colonic migration of NAGI stent causing luminal obstruction: An unusual complication of EUS-guided drainage of WON.

Rational Design of Additive with Suitable Functional Groups Toward High‐Quality FA0.75MA0.25SnI3 Films and Solar Cells

Stability and efficiency issues are closely related with poor perovskite film quality in perovskite solar cells (PSCs). Herein, 2‐aminophenol (C6H7NO) and 2‐amino‐4‐fluorophenol (C6H6FNO) are introduced to improve film quality of FA0.75MA0.25SnI3, both of which consist of —NH2 and —OH groups, and the latter also contains —F group. The experimental and theoretical analyses show both —NH2 and —OH groups interact with I of the SnI64− octahedron via hydrogen bond and fluorinated group with low surface energy causes spontaneous migration of C6H6FNO to solution–air surface and induces initial crystal nucleation and growth from surface, both of which contribute to improved film morphology and crystallinity and suppressed Sn2+ oxidation via reducing defect‐state density and nonradiative recombination. The F atom of C6H6FNO facing outward protects FA0.75MA0.25SnI3 from water penetration due to its hydrophobic feature. The C6H6FNO‐doped PSC acquires a champion efficiency of 9.50% and a long‐term stability of &gt;800 h (80% efficiency remained in N2).