Human assembloid model of the ascending neural sensory pathway.

The ascending somatosensory pathways convey crucial information about pain, touch, itch, and body part movement from peripheral organs to the central nervous system. Despite a significant need for effective therapeutics modulating pain and other somatosensory modalities, clinical translation remains challenging, which is likely related to species-specific features and the lack of in vitro models to directly probe and manipulate this polysynaptic pathway. Here, we established human ascending somatosensory assembloids (hASA)- a four-part assembloid completely generated from human pluripotent stem cells that integrates somatosensory, spinal, diencephalic, and cortical organoids to model the human ascending spinothalamic pathway. Transcriptomic profiling confirmed the presence of key cell types in this circuit. Rabies tracing and calcium imaging showed that sensory neurons connected with dorsal spinal cord projection neurons, which ascending axons further connected to thalamic neurons. Following noxious chemical stimulation, single neuron calcium imaging of intact hASA demonstrated coordinated response, while four-part concomitant extracellular recordings and calcium imaging revealed synchronized activity across the assembloid. Loss of the sodium channel SCN9A, which causes pain insensitivity in humans, disrupted synchrony across the four-part hASA. Taken together, these experiments demonstrate the ability to functionally assemble the essential components of the human sensory pathway. These findings could both accelerate our understanding of human sensory circuits and facilitate therapeutic development.

Hippocampal engram networks for fear memory recruit new synapses and modify pre-existing synapses in vivo.

As basic units of neural networks, ensembles of synapses underlie cognitive functions such as learning and memory. These synaptic engrams show elevated synaptic density among engram cells following contextual fear memory formation. Subsequent analysis of the CA3-CA1 engram synapse revealed larger spine sizes, as the synaptic connectivity correlated with the memory strength. Here, we elucidate the synapse dynamics between CA3 and CA1 by tracking identical synapses at multiple time points by adapting two-photon microscopy and dual-eGRASP technique in vivo. After memory formation, synaptic connections between engram populations are enhanced in conjunction with synaptogenesis within the hippocampal network. However, extinction learning specifically correlated with the disappearance of CA3 engram to CA1 engram (E-E) synapses. We observed "newly formed" synapses near pre-existing synapses, which clustered CA3-CA1 engram synapses after fear memory formation. Overall, we conclude that dynamics at CA3 to CA1 E-E synapses are key sites for modification during fear memory states.

Synaptic ensembles between raphe and D1R-containing accumbens shell neurons underlie postisolation sociability in males.

Social animals expend considerable energy to maintain social bonds throughout their life. Male and female mice show sexually dimorphic behaviors, yet the underlying neural mechanisms of sociability and their dysregulation during social disconnection remain unknown. Dopaminergic neurons in dorsal raphe nucleus (DRNTH) is known to contribute to a loneliness-like state and modulate sociability. We identified that activated subpopulations in DRNTH and nucleus accumbens shell (NAcsh) during 24 hours of social isolation underlie the increase in isolation-induced sociability in male but not in female mice. This effect was reversed by chemogenetically and optogenetically inhibiting the DRNTH-NAcsh circuit. Moreover, synaptic connectivity among the activated neuronal ensembles in this circuit was increased, primarily in D1 receptor-expressing neurons in NAcsh. The increase in synaptic density functionally correlated with elevated dopamine release into NAcsh. Overall, specific synaptic ensembles in DRNTH-NAcsh mediate sex differences in isolation-induced sociability, indicating that sex-dependent circuit dynamics underlie the expression of sexually dimorphic behaviors.

Exogenous expression of an allatotropin-related peptide receptor increased the membrane excitability in Aplysia neurons.

Neuropeptides act mostly on a class of G-protein coupled receptors, and play a fundamental role in the functions of neural circuits underlying behaviors. However, physiological functions of some neuropeptide receptors are poorly understood. Here, we used the molluscan model system Aplysia and microinjected the exogenous neuropeptide receptor apATRPR (Aplysia allatotropin-related peptide receptor) with an expression vector (pNEX3) into Aplysia neurons that did not express the receptor endogenously. Physiological experiments demonstrated that apATRPR could mediate the excitability increase induced by its ligand, apATRP (Aplysia allatotropin-related peptide), in the Aplysia neurons that now express the receptor. This study provides a definitive evidence for a physiological function of a neuropeptide receptor in molluscan animals.

Changes in hemostatic factors after kidney transplantation: A retrospective cohort study.

ABSTRACT: Chronic kidney disease affects hemostasis in complex ways, producing both thrombotic and hemorrhagic diatheses. These changes may impact patient morbidity and mortality pre-transplantation, as well as allograft survival after kidney transplantation (KT). This study was conducted to analyze changes in hemostatic factors in the early post-KT period.We retrospectively analyzed 676 recipients of kidney allografts from December 2009 to December 2014. Patients receiving plasmapheresis pre- or post-KT, experiencing early allograft failure, or receiving anticoagulants or antiplatelet agents pre- or post-KT were excluded.Of the 367 included patients, acute (≤1 month) rejection occurred in 4.1% and delayed graft function occurred in 3.3%. Postoperative bleeding complications occurred in 7.9% of patients and thrombotic complications in 3.3%. Pre-transplantation, recipients had below normal hemoglobin, above normal d-dimer and homocysteine levels, and elevated rates of antiphospholipid antibodies. Hemoglobin increased to almost normal by postoperative day (POD) 28 (P  < .001). d-dimer increased on POD7, 14, and 28, although the values were not significantly different from pre-KT. The pattern of d-dimer changes suggested that they were a nonspecific consequence of major surgery. Homocysteine decreased to normal by POD7 (P  < .001). The percentage of patients with ≥1 prothrombotic factor was 82.0% pre-KT and only 14.2% on POD28 (P  < .001).The most of patients exhibited prothrombotic tendencies, including increased d-dimer and homocysteine, and increased prevalence of antiphospholipid antibodies before transplantation. They also had pre-transplantation anemia, suggesting a concomitant bleeding diathesis. However, most of these abnormal hemostatic factors improved or resolved after KT.

Synaptic correlates of associative fear memory in the lateral amygdala.

Successful adaptation to the environment requires an accurate response to external threats by recalling specific memories. Memory formation and recall require engram cell activity and synaptic strengthening among activated neuronal ensembles. However, elucidation of the underlying neural substrates of associative fear memory has remained limited without a direct interrogation of extinction-induced changes of specific synapses that encode a specific auditory fear memory. Using dual-eGRASP (enhanced green fluorescent protein reconstitution across synaptic partners), we found that synapses among activated neuronal ensembles or activated synaptic ensembles showed a significantly larger spine morphology at auditory cortex (AC)-to-lateral amygdala (LA) projections after auditory fear conditioning in mice. Fear extinction reversed these enhanced synaptic ensemble spines, whereas re-conditioning with the same tone and shock restored the spine size of the synaptic ensemble. We suggest that synaptic ensembles encode and represent different fear memory states.

Selection of More Vulnerable Patients for Cytomegalovirus Infection in Renal Transplant Recipients With Antithymocyte Globulin Induction Therapy: An Analysis of Risk Factors and Cell-Mediated Immunity.

BACKGROUND: Cytomegalovirus (CMV) infection is an important complication after kidney transplantation (KT). Antithymocyte globulin (ATG) increases the risk for CMV infection, and universal prophylaxis is recommended during the first 3 to 6 months after ATG induction in CMV-seropositive recipients. However, following this recommendation is not easy because the cost is high. The aim of this study was to determine who, among high-risk KT recipients, are more vulnerable to CMV infections. METHODS: We retrospectively analyzed the medical records of patients who underwent KT with ATG induction therapy at a single institute from April 2014 to June 2019. We assessed pretransplant recipient characteristics to determine the CMV infection risk factors. Cell-mediated immunity was evaluated with a lymphocyte subset test before transplantation and at the time of discharge. We included 227 patients in the study. RESULTS: CMV-DNAemia was associated with donor type (deceased donor), the duration of renal replacement therapy, and the ATG dose. Multivariable analysis revealed that donor type is the primary risk factor for CMV-DNAemia. We also found that CD4+ cell counts were significantly lower in CMV-DNAemia recipients at the time of discharge. CONCLUSION: The risk for CMV infection in CMV-seropositive KT recipients with ATG induction therapy increases when a graft is received from a deceased donor with renal impairment and when insufficient CD4+ cells are present during recovery.

Endovascular treatment for transplant renal artery stenosis: A retrospective cohort study.

ABSTRACT: Transplant renal artery stenosis (TRAS) is the most common (1%-23%) vascular complication following kidney transplantation. The aim of this study was to review our experience with an endovascular approach to treat TRAS.We retrospectively reviewed kidney transplant recipients who underwent percutaneous transluminal angioplasty (PTA) due to TRAS in our institute from January 2009 to December 2015. We analyzed the patient's baseline characteristics, postoperative renal function, blood pressure evolution, and the number of pre- and post-procedure antihypertensive drugs.A total of 21 patients (15 men, 6 women) were treated with the endovascular technique. The predominant presentation was graft dysfunction (76.2%). Stenosis or hemodynamic kinking was located at the anastomosis in 7 (33.3%) patients, proximal to the anastomosis in 13 (61.9%) patients, and distal the anastomosis in 1 (4.8%) patient. PTA without stent placement was performed in 7 patients (33.3%), and PTA with stent placement was performed in 14 patients (67.7%). Serum creatinine levels demonstrated no difference between the pre-procedure level and that on discharge day (1.61 mg/dl [0.47-3.29 mg/dl] vs 1.46 mg/dl [0.47-3.08 mg/dl]; P = .33). The glomerular filtration rate also showed no difference between the pre-procedure value and that on discharge day (53.6 ml/min [22.4-145.7 ml/min] vs 57.0 ml/min [17.56 -145 ml/min]; P = .084). Systolic blood pressure and diastolic blood pressure (DBP) varied from 137 mm Hg (120-160 mm Hg) and 84 mm Hg (70-100 mm Hg) pre-procedure to 129 mm Hg (90-150 mm Hg) and 79 mm Hg (60-90 mm Hg) at discharge, respectively (P = .124 and P = .07). The number of antihypertensive medications significantly decreased from 1.5 (0-6) pre-procedure to 0.5 (0-2) at discharge (P = .023). In our study, there were no technical failures, procedure-related complications or deaths. During the follow-up period, the free-from-reintervention rate was 100%, and graft failures occurred in 2 patients (9.5%) due to rejection.Endovascular procedures for TRAS show a high technical success rate with a low complication rate and a low reintervention rate. PTA showed a trend toward a positive impact on lowering serum creatinine, systolic blood pressure, and diastolic blood pressure and improving estimated glomerular filtration rate, and the number of antihypertensive medications could be significantly reduced after this procedure.

PKA drives an increase in AMPA receptor unitary conductance during LTP in the hippocampus.

Long-term potentiation (LTP) at hippocampal CA1 synapses can be expressed by an increase either in the number (N) of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors or in their single channel conductance (γ). Here, we have established how these distinct synaptic processes contribute to the expression of LTP in hippocampal slices obtained from young adult rodents. LTP induced by compressed theta burst stimulation (TBS), with a 10 s inter-episode interval, involves purely an increase in N (LTPN). In contrast, either a spaced TBS, with a 10 min inter-episode interval, or a single TBS, delivered when PKA is activated, results in LTP that is associated with a transient increase in γ (LTPγ), caused by the insertion of calcium-permeable (CP)-AMPA receptors. Activation of CaMKII is necessary and sufficient for LTPN whilst PKA is additionally required for LTPγ. Thus, two mechanistically distinct forms of LTP co-exist at these synapses.

Loss of the neuronal genome organizer and transcription factor CTCF induces neuronal death and reactive gliosis in the anterior cingulate cortex.

CCCTC-binding factor (CTCF) is a genome organizer that regulates gene expression through transcription and chromatin structure regulation. CTCF also plays an important role during the developmental and adult stages. Cell-specific CTCF deletion studies have shown that a reduction in CTCF expression leads to the development of distinct clinical features and cognitive disorders. Therefore, we knocked out Ctcf (CTCF cKO) in the excitatory neurons of the forebrain in a Camk2a-Cre mouse strain to examine the role of CTCF in cell death and gliosis in the cortex. CTCF cKO mice were viable, but they demonstrated an age-dependent increase in reactive gliosis of astrocytes and microglia in the anterior cingulate cortex (ACC) from 16 weeks of age prior to neuronal loss observed at over 20 weeks of age. Consistent with these data, qRT-PCR analysis of the CTCF cKO ACC revealed changes in the expression of inflammation-related genes (Hspa1a, Prokr2 and Itga8) linked to gliosis and neuronal death. Our results suggest that prolonged Ctcf gene deficiency in excitatory neurons results in neuronal cell death and gliosis, possibly through functional changes in inflammation-related genes.

A Randomized Controlled Trial Comparing Analgesic Efficacies of an Ultrasound-Guided Approach with and without a Combined Pressure Measurement Technique for Thoracic Paravertebral Blocks After Open Thoracotomy.

PURPOSE: Ultrasound-guided thoracic paravertebral block (TPVB) is an established means for providing postoperative analgesia in thoracic surgery. However, there are conflicting results regarding the efficacy of post-thoracotomy pain management of ultrasound-guided TPVB when compared with that using traditional landmark approach. We therefore conducted a comparative study to evaluate the analgesic efficacy of TPVB when pressure measurement during needle advancement is combined with an ultrasound-guided approach. PATIENTS AND METHODS: The patients scheduled for lobectomy through thoracotomy were randomly allocated to receive either the ultrasound-guided approach only group (U group) or the ultrasound-guided approach combined with pressure measurement group (UP group) (n = 36 per group). Before thoracic muscle closure, 0.375% ropivacaine (20 mL) was administered as a bolus, followed by a continuous infusion of 0.2% ropivacaine (0.1 mL/kg/hr) in both groups. Postoperative pain was assessed using the visual analogue scale (VAS) pain score while resting and coughing. Local anesthetics and pethidine usage and sensory block area were also evaluated. RESULTS: The UP group showed significantly lower VAS scores, local anesthetics and pethidine usage, and a wider sensory block area than the U group. CONCLUSION: A combined technique with ultrasound guidance and pressure measurement provided a superior analgesic effect over that of an ultrasound-guided approach alone for the management of post-thoracotomy pain.

Neur1 and Neur2 are required for hippocampus-dependent spatial memory and synaptic plasticity.

Neur1 and Neur2, mouse homologs of the Drosophila neur gene, consist of two neuralized homology repeat domains and a RING domain. Both Neur1 and Neur2 are expressed in the whole adult brain and encode E3 ubiquitin ligases, which play a crucial role in the Notch signaling pathways. A previous study reported that overexpression of Neur1 enhances hippocampus-dependent memory, whereas the role of Neur2 remains largely unknown. Here, we aimed to elucidate the respective roles of Neur1 and Neur2 in hippocampus-dependent memory using three lines of genetically modified mice: Neur1 knock-out, Neur2 knock-out, and Neur1 and Neur2 double knock-out (D-KO). Our results showed that spatial memory was impaired when both Neur1 and Neur2 were deleted, but not in the individual knock-out of either Neur1 or Neur2. In addition, basal synaptic properties estimated by input-output relationships and paired-pulse facilitation did not change, but a form of long-term potentiation that requires protein synthesis was specifically impaired in the D-KO mice. These results collectively suggest that Neur1 and Neur2 are crucially involved in hippocampus-dependent spatial memory and synaptic plasticity.

Incidence and outcome of isolated distal deep vein thrombosis in kidney transplant recipients.

PURPOSE: Isolated distal deep vein thrombosis (IDDVT) is a localized lesion; nonetheless, the risk of proximal vein propagation makes it difficult to decide on the treatment protocol-that is, whether immediate anticoagulation after diagnosis or surveillance via serial imaging should be employed. This study aimed to investigate the appropriate treatment protocol for IDDVT in kidney transplant recipient (KTR). METHODS: Surveillance for venous thromboembolism (VTE) was performed using duplex ultrasonography (DUS) before transplant surgery and at 1 week, 2 weeks, 1 month, 3 months, 6 months, and 1 year after transplant surgery. Dual mechanical prophylaxis was administered to prevent VTE. RESULTS: In total, 60 out of 829 patients (7.2%) developed VTE, with 49 cases (81.6%) of IDDVT. Among IDDVT patients, 15 patients were treated using anticoagulation-first strategy, whereas the remaining 34 patients were treated using surveillance-first strategy. No patient in either group exhibited thrombus extension into the proximal vein or recurrence within 1 year from transplant surgery. CONCLUSION: In Korean KTR, extension of IDDVT into the proximal vein could be prevented safely and effectively by serial DUS surveillance along with the maintenance of mechanical prophylaxis. However, the patients who have high thrombus burden or are difficult to get repeated DUS require the use of anticoagulation in early stages.

Outcomes of bedside peripherally inserted central catheter placement: a retrospective study at a single institution.

BACKGROUND: Bedside insertion of peripherally inserted central catheters (PICCs) has higher rates of malposition than fluoroscopic-guided PICC placement. This study evaluated the success rate of bedside PICC placement, variations in tip location, and risk factors for malposition. METHODS: This retrospective study included patients who underwent bedside PICC placement from January 2013 to September 2014 in a single institution. The procedure was conducted under ultrasound guidance or by a blind method. After PICC placement, tip location was determined by chest X-ray. RESULTS: The overall venous access success rate with bedside PICC placement was 98.1% (1,302/ 1,327). There was no significant difference in the venous access success rate between ultrasound-guided placement (868/880, 98.6%) and a blind approach placement (434/447, 97.1%). Optimal tip position was achieved on the first attempt in 1,192 cases (91.6%). Repositioning was attempted in 65 patients; 60 PICCs were repositioned at the bedside, two PICCs were repositioned under fluoroscopic guidance, and three PICCs moved to the desired position without intervention. Final optimal tip position after repositioning was achieved in 1,229 (94.4%). In logistic regression analysis, five factors associated with tip malposition included female sex (Exp(B), 1.687; 95% confidence interval [CI], 1.180 to 2.412; P=0.004), older age (Exp(B), 1.026; 95% CI, 1.012 to 1.039; P<0.001), cancer (Exp(B), 0.650; 95% CI, 0.455 to 0.929; P=0.018), lung disease (Exp(B), 2.416; 95% CI, 1.592 to 3.666; P<0.001), and previous catheter insertions (Exp(B), 1.262; 95% CI, 1.126 to 1.414; P<0.001). CONCLUSIONS: Bedside PICC placement without fluoroscopy is effective and safe in central venous catheters. Potential risk factors associated with catheter tip malposition include older age, female sex, cancer, pulmonary disease, and previous central vein catheterizations.

Current status of intestinal transplantation in East Asia.

PURPOSE OF REVIEW: Intestinal transplantation (ITx) activity remains low in East Asia. We conducted a multinational, retrospective study on patients who underwent ITx in Korea, Taiwan, and Japan, to provide an overview and to foresee future developments and collaborations in this region. RECENT FINDINGS: Total 71 ITx were performed in 67 patients. Living donor ITx was most commonly conducted in Japan (n = 13). Despite the low caseload, all three countries demonstrated acceptable patient survival rates of approximately 70% at 5 years. Over 70% of recipients with a functioning graft were free from total parenteral nutrition. SUMMARY: There is an urgent need to establish a nationwide and multinational registry of ITx recipients and patients with intestinal failure in East Asia. An efficient referral system to specialized intestinal rehabilitation and ITx centers and a multidisciplinary team approach is also warranted to provide state-of-the-art treatment for patients desperately waiting for a chance to survive.

Bilateral vocal cord paralysis during emergence from general anesthesia in a patient with Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder that affects the extrapyramidal system, and respiratory dysfunction has also been noted in patients with PD. However, acute upper airway obstruction due to bilateral vocal cord paralysis is a very rare finding in PD. Here, we describe a rare life-threatening respiratory failure caused by bilateral vocal cord paralysis in an elderly woman with PD during emergence from general anesthesia. The tracheostomy was performed on the postoperative period because the condition persisted. The general anesthesia in PD may have aggravated vocal cord impairment. We recommend when a patient with PD is scheduled for general anesthesia that the anesthesiologist performs careful preoperative examinations, strictly monitors respiratory function, and rapidly manages acute upper airway obstruction.

Venous Thromboembolism Following Abdominal Cancer Surgery in the Korean Population: Incidence and Validation of a Risk Assessment Model.

BACKGROUND: A cancer patient slated for abdominal surgery is considered to be at moderate to high risk for developing venous thromboembolism (VTE), but the incidence is quite low in Korean patients. Most risk assessment models and recommendations for VTE management are from Western reports, however they possibly overestimate the risk of VTE in the Korean population. METHODS: We retrospectively reviewed the medical records of 1966 patients who were diagnosed with abdominal organ cancer and required surgical treatment. RESULTS: Each patient was rated using the Caprini risk scoring model. The mean score was 7.5 ± 0.7 points; 98.4% of patients were classified as high risk for VTE. Symptomatic VTE occurred in eight patients, and the overall incidence was 0.4%. The mean Caprini score for VTE patients was 8.8 ± 1.9 points. In the group with scores between 5 and 9 points, the incidence was 0.3-0.5%, while in patients with scores > 10 points, the incidence of VTE was found to be 1.12%. CONCLUSIONS: The risk stratification system in the Caprini scoring model needs to be modified based on the actual incidence in the Korean population.

A Half-Century 3000 Cases of Kidney Transplant Experiences in a Single Hospital: the Longest Registry in Korea.

BACKGROUND: This study aims to analyze the entire registry of kidney transplant over the past 50 years and understand the clinical significance. METHODS: From the data on 3012 kidney transplants performed at our center between March 1969 and September 2018, we analyzed retrospectively clinical variables. RESULTS: Until September 2018, there have been 3012 kidney transplants performed. The number of primary transplant cases was 2755 (91.8%), which included 16 cases of simultaneous liver-kidney transplant, and the number of repeated transplants was 245 (225 second transplants [7.5%] and 20 third transplants [0.7%]). There were 3 simultaneous pancreas kidney transplants, and 3 small bowel-kidney transplants, one of them being transplanted at the same time. There was a single simultaneous heart-kidney transplant. The viability rates of a transplanted kidney for 1, 5, 10, 20, and 30 years were 97%, 92%, 90%, 51%, and 36%, respectively, and the patient survival rates were 96%, 89%, 82%, 64%, and 52%, respectively. Five-year graft survival rate of the first 1000 cases was 64.6%; those of the 1001st to 2000th cases and 2001st to 3012th cases were 87.6% and 88.8%, respectively. There are statistically significant differences among the groups. CONCLUSION: This study has identified the appropriate selection or control of immunotherapy, based on the risk level of kidney transplant recipient, is needed to minimize chronic rejection, which is the key cause of transplanted kidney failure.

Long-Term Outcomes of Renal Function After Adult Intestinal Transplantation at a Single Small-Volume Center: 2 Cases of Renal Transplantation.

PURPOSE: Renal dysfunction more frequently occurs after intestinal transplantation (ITx) than after heart, lung, or liver transplantation. We provide a clinical analysis of renal function after adult ITx. METHODS: We retrospectively analyzed 8 adult ITx patients who survived for at least 6 months between 2004 and 2018. Glomerular filtration rate (GFR) measurements were performed at baseline, at 3 and 6 months post-transplantation, and yearly. The median follow-up duration was 53.5 months. RESULTS: All cases were isolated ITx; 3 received living-donor ITx, and 5 received deceased-donor ITx. The mean baseline GFR was 97 mL/min/1.73 m2. The GFR had decreased by more than 50% of baseline at 1 year post-transplant. Renal dysfunction was observed in 4 patients. Two patients developed acute kidney injury due to acute rejection and sepsis. One of these patients fully recovered renal function, but the second patient died. Another 2 patients developed chronic kidney disease and required hemodialysis (HD) within 6 and 3 years, respectively. The first living-donor ITx patient lost renal function progressively over 6 years after ITx. She received a renal graft from the same living donor as for the ITx after 3 years of HD. The other patient (deceased-donor ITx) received a kidney from his daughter at 5 months after HD. CONCLUSIONS: To obtain an accurate assessment of renal function, frequent direct measurements of GFR should be performed to facilitate early diagnosis of renal impairment and to determine subsequent strategies to improve renal function after ITx.