Human iPSC-liver organoid transplantation reduces fibrosis through immunomodulation.

Donor organ shortages for transplantation remain a serious global concern, and alternative treatment is in high demand. Fetal cells and tissues have considerable therapeutic potential as, for example, organoid technology that uses human induced pluripotent stem cells (hiPSCs) to generate unlimited human fetal-like cells and tissues. We previously reported the in vivo vascularization of early fetal liver-like hiPSC-derived liver buds (LBs) and subsquent improved survival of recipient mice with subacute liver failure. Here, we show hiPSC-liver organoids (LOs) that recapitulate midgestational fetal liver promote de novo liver generation when grafted onto the surface of host livers in chemical fibrosis models, thereby recovering liver function. We found that fetal liver, a hematopoietic tissue, highly expressed macrophage-recruiting factors and antifibrotic M2 macrophage polarization factors compared with the adult liver, resulting in fibrosis reduction because of CD163+ M2-macrophage polarization. Next, we created midgestational fetal liver-like hiPSC-LOs by fusion of hiPSC-LBs to induce static cell-cell interactions and found that these contained complex structures such as hepatocytes, vasculature, and bile ducts after transplantation. This fusion allowed the generation of a large human tissue suitable for transplantation into immunodeficient rodent models of liver fibrosis. hiPSC-LOs showed superior liver function compared with hiPSC-LBs and improved survival and liver function upon transplantation. In addition, hiPSC-LO transplantation ameliorated chemically induced liver fibrosis, a symptom of liver cirrhosis that leads to organ dysfunction, through immunomodulatory effects, particularly on CD163+ phagocytic M2-macrophage polarization. Together, our results suggest hiPSC-LO transplantation as a promising therapeutic option for liver fibrosis.

Treatment of Ezetimibe lowers total and low-density lipoprotein cholesterol in hypercholesterolemic dogs with hyperadorenocorticism.

Ezetimibe is a cholesterol absorption inhibitor that blocks the intestinal absorption of both biliary and dietary cholesterol, thereby lowering primarily low density lipoprotein-cholesterol (LDL-chol) in human studies. This study aimed to investigate the effects of ezetimibe on dyslipidemia control in nine dogs with hypercholesterolemia. Changes in total cholesterol (T-chol) and each lipoprotein fractions were evaluated at 0, 2, and 4 months following initiation of ezetimibe treatment. A significant decrease in T-chol was observed, and a mean T-chol concentration below 400 mg/dL was achieved at 2 and 4 months. Furthermore, a significant decrease in LDL-chol was observed (-53.3% and -64.3% at 2 and 4 months, respectively). Taken together, treatment of ezetimibe could lower LDL-chol levels in dogs with hypercholesterolemia.

Proton-Pump Inhibitors and Risk of Bloodstream Infection without an Identifiable Source: a Hospital-Based Case-Control Study.

The association between proton-pump inhibitor (PPI) use and systemic infections caused by bacterial translocation is unclear. This study aimed to investigate whether patients receiving PPI therapy have a higher risk of bloodstream infections (BSI) without an identifiable source of infection. We conducted a hospital-based case-control study which enrolled all patients aged 20 years and older who were hospitalized in Ichinomiya Nishi Hospital with BSI confirmed by two sets of positive blood cultures in 2019. Patient data were collected from medical records, and the bacterial translocation-type (BT-type) BSI group was defined as patients with BSI without an identifiable source of infection, whereas those with a BSI from an identifiable source were assigned to the control group based on the diagnostic criteria for each infectious disease. Data from 309 patients, including 66 cases and 243 controls, were analyzed. Compared with PPI non-users, PPI users had a 2.4-fold higher risk of developing BT-type BSI after controlling for potential confounders (adjusted odds ratio: 2.41, 95% confidence interval: 1.29-4.51, P = 0.006). In conclusion, PPI use is associated with a higher risk of BSI without an identifiable source; therefore, PPI use might increase the risk of BSI secondary to bacterial translocation.

Regioselective Coupling of Different Conjugate Esters by Magnesium Metal Reduction: A Route to Unsymmetrical Adipic Acid Esters.

A novel tactic to synthesize unsymmetrical 3-aryladipic acid esters has been developed via magnesium-promoted reductive coupling of ethyl cinnamates with methyl acrylate. In the present methodology, 3-aryladipic acid derivatives were prepared with good functional group tolerance and a wide substrate scope under very mild reaction conditions in good yields. The application of this reaction to dienic acid esters led to the successful control of the reaction to give 5-aryl-oct-3-enedioic acid esters with high regioselectivity.

Induced pluripotent stem cell-derived hematopoietic stem and progenitor cells induce mixed chimerism and donor-specific allograft tolerance.

In transplantation using allogeneic induced pluripotent stem cells (iPSCs), strategies focused on major histocompatibility complexes were adopted to avoid immune rejection. We showed that minor antigen mismatches are a risk factor for graft rejection, indicating that immune regulation remains one of the most important issues. In organ transplantation, it has been known that mixed chimerism using donor-derived hematopoietic stem/progenitor cells (HSPCs) can induce donor-specific tolerance. However, it is unclear whether iPSC-derived HSPCs (iHSPCs) can induce allograft tolerance. We showed that 2 hematopoietic transcription factors, Hoxb4 and Lhx2, can efficiently expand iHSPCs with a c-Kit+Sca-1+Lineage- phenotype, which possesses long-term hematopoietic repopulating potential. We also demonstrated that these iHSPCs can form hematopoietic chimeras in allogeneic recipients and induce allograft tolerance in murine skin and iPSC transplantation. With mechanistic analyses, both central and peripheral mechanisms were suggested. We demonstrated the basic concept of tolerance induction using iHSPCs in allogeneic iPSC-based transplantation.

Extra-Anatomical Bypass for Chronic Mesenteric Ischemia with Saphenous Vein Grafts from a Previous Axillofemoral Artery Bypass Graft: A Case Report.

A 74-year-old woman who was diagnosed with chronic mesenteric ischemia was under hemodialysis maintenance and had previously undergone axillobifemoral bypass surgery because of abdominal aortoiliac occlusion. Endovascular and antegrade or retrograde surgical revascularizations from the aortoiliac artery were contraindicated because of a severely calcified arteriosclerotic lesion, which included aortoiliac occlusion. During median laparotomy, revascularization consisting of bypass grafting from a previous prosthetic graft to the mesenteric arteries was performed using saphenous vein grafts. Although extra-anatomical bypass for chronic mesenteric ischemia is challenging, it provides a feasible option in cases where conventional endovascular or surgical revascularization is contraindicated.

Pulmonary solid adenocarcinoma in a dog.

A 12-year-old castrated male Beagle dog presented with a 1-month history of progressive loss of appetite and cough. One month after the initial visit, a detailed clinical examination was performed due to weight loss and persistent cough. Computed tomography demonstrated diffuse opacification of the entire right lung and cranial lobe of the left lung. Samples of the pulmonary lesions obtained by fine-needle aspiration (FNA) were highly cellular with scattered and clustered foci of large round cells, suggestive of a round cell tumour. Ten days after the FNA, the dog was euthanized due to decreased activity and severe respiratory symptoms. At necropsy, enlargement of the entire right lung and cranial lobe of the left lung was seen. The external and cut surfaces of the lungs were homogeneously grey-white. Histopathological examination of sections of the right lung and the cranial lobe of the left lung revealed proliferation of large round or polygonal neoplastic cells arranged in nests of variable size separated by a thin fibrous stroma. Neoplastic cells were immunopositive for cytokeratin and thyroid transcription factor-1 but negative for vimentin, CD204, chromogranin A and synaptophysin. On the basis of these findings, the tumour was diagnosed as pulmonary solid adenocarcinoma.

Thoracic endovascular aortic repair for chronic aortic dissection after total arch replacement for aberrant right subclavian artery: A case report.

An aberrant right subclavian artery (ARSA) is an extremely rare congenital anomaly that forms during aortic arch development. Most reports of thoracic endovascular aortic repair (TEVAR) described an ARSA in the right aortic arch, but it is rare in the left aortic arch. We present the case of a 66-year-old man who underwent total arch replacement because of acute type A aortic dissection. An outpatient follow-up examination revealed that the aortic diameter enlargement exceeded 60 mm because of false lumen entry from the ARSA. Therefore, surgical intervention was planned. TEVAR, ARSA embolization, and bilateral axillary bypass surgery were successfully performed for a chronic dissecting aortic aneurysm for which the ARSA was the inflow route. He was discharged 12 days after surgery. Four years later, no enlargement of the aneurysm diameter was observed. TEVAR is a minimally invasive and useful treatment option for chronic type B dissections with an ARSA associated with the left aortic arch; however, patients with an ARSA have fragile blood vessels and require careful follow-up.

Rare epithelioid hemangioendothelioma in the brachiocephalic vein for long-term survival after surgery: A case report.

Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor. In this report, we describe the case of a 62-year-old man who presented with pain in the left clavicle and swelling of the left upper limb. Contrast-enhanced computed tomography revealed an intravascular tumor, which was completely resected surgically. Histopathological examination and immunohistochemical staining revealed that it was epithelioid hemangioendothelioma with occurrence in the left brachiocephalic vein. It has been 6 years since the surgery was performed, and no recurrence has been observed. Epithelioid hemangioendothelioma may recur or metastasize and therefore requires careful follow-up.

Successful treatment of feline hyperadrenocorticism with pituitary macroadenoma using radiation therapy: a case study.

A 10-year-old castrated male cat showing behavioral (irritation, prowling, and tumbling) and cutaneous abnormalities such as dermal fragility was diagnosed as hyperadrenocorticism with pituitary macroadenoma, concurrent with insulin dependent diabetes mellitus. Pituitary enlargement (18.0 mm) was observed during magnetic resonance imaging. High endogenous adrenocorticotropic hormone levels (>2,500 pg/ml) were also observed. Although trilostane treatment (5-10 mg/head, daily) was commenced, the clinical signs did not disappear. Insulin and trilostane treatment were discontinued on day 86 after first day of radiation therapy (4 Gy/12 fractions). After radiation therapy, a decreased pituitary tumor size (10.7 mm) was observed on day 301; neurological and dermatological signs exhibited remission. Radiation therapy is the treatment of choice for feline hyperadrenocorticism with pituitary macroadenoma with neurological signs.

[Huge Tricuspid Pouch with Heart Failure:Report of a Case].

Tricuspid pouch forms during the spontaneous closure of a ventricular septal defect (VSD). Cases have been reported in which the tricuspid pouch was discovered for the first time during surgery and could not be distinguished from an aneurysm of the membranous septum( AMS). A 58-year-old woman had a heart murmur. Transthoracic echocardiography showed an aneurysm-like pouch protruding into the right ventricle. Magnetic resonance imaging could not distinguish between AMS and tricuspid pouch;however, contrast-enhanced computed tomography showed a VSD. The membranous structure comprised multiple lobules, and the tendon of the papillary muscles was continuous with the tricuspid valve. Intraoperatively, the tricuspid valve septal leaflet was adhered to the defect hole. It was incised along the annulus, the VSD was closed with a bovine pericardial patch, and the annulus of the tricuspid valve septal leaflet was suture closed. The patient was discharged after a good postoperative course.

Impact of Hemodialysis on Clinical Outcomes in Patients Undergoing Lower Extremity Bypass Surgery for Peripheral Artery Disease-10-year Follow-Up Study.

We investigated the clinical impact of hemodialysis on long-term outcomes of bypass surgery in patients with peripheral artery disease. We evaluated 660 consecutive patients who underwent successful bypass surgery (392 hemodialysis and 268 non-hemodialysis). The endpoint was amputation-free survival (AFS). To minimize differences in clinical characteristics between the 2 groups, propensity score matching was performed. The AFS rates for 10-year follow-up were 39.3% and 67.7% in hemodialysis and non-hemodialysis patients [hazard ratio (HR) 2.21, 95% confidence interval (CI) 1.65-3.01, P < .0001]. Cumulative incidence of amputation was higher in the hemodialysis group than in the non-hemodialysis group [(19.4 vs 8.4%, HR 2.15, 95% CI 1.29-3.74, P = .0027). In a matched cohort (n = 210 each), AFS was still lower in the hemodialysis patients (53.1 vs 66.3%, HR 1.94, 95% CI 1.36-2.82, P = .0003). However, there was no significant difference in amputation rate between the groups (10.5 vs 10.6%, HR .97, 95% CI 0.49-1.87, P = .93). In a sub-analysis of patients with critical limb ischemia, similar results were obtained. The 10-year AFS was consistently lower in the hemodialysis group than in the non-hemodialysis group. However, the amputation rate was comparable between the groups when matched for the differences in clinical characteristics.

Evaluation of immunosuppression protocols for MHC-matched allogeneic iPS cell-based transplantation using a mouse skin transplantation model.

BACKGROUND: Off-the-shelf major histocompatibility complex (MHC)-matched iPS cells (iPSC) can potentially initiate host immune responses because of the existence of numerous minor antigens. To suppress allo-immune responses, combination of immunosuppressants is usually used, but its efficacy to the allogeneic iPSC-based transplantation has not been precisely evaluated. METHODS: Three transplantation models were used in this study; MHC-matched, minor antigen-mismatched mouse skin or iPSC-graft transplantation, and fully allogeneic human iPSC-derived liver organoid transplantation in immune-humanized mice. The recipients were treated with triple drugs combination (TDC; tacrolimus, methylprednisolone, and mycophenolate mofetil) or co-stimulatory molecule blockade (CB) therapy with some modifications. Graft survival as well as anti-donor T and B cell responses was analyzed. RESULTS: In the mouse skin transplantation model, immunological rejection caused by the minor antigen-mismatch ranged from mild to severe according to the donor-recipient combination. The TDC treatment could apparently control the mild skin graft rejection when combined with a transient T cell depletion, but unexpected anti-donor T or B cell response was observed. On the other hand, CB therapy, particularly when combined with rapamycin treatment, was capable of attenuating both mild and severe skin graft rejection and allowing them to survive long-term without any unfavorable anti-donor immune responses. The efficacy of the CB therapy was confirmed in both mouse and human iPSC-derived graft transplantation. CONCLUSIONS: The findings suggest that the CB-based treatment seems suitable to well manage the MHC-matched allogeneic iPSC-based transplantation. The TDC-based treatment may be also used to suppress the rejection, but screening of its severity prior to the transplantation seems to be needed.

Case of persistent sciatic artery in a dialysis patient with critical limb ischemia.

Persistent sciatic artery is a rare congenital malformation (incidence rate, 0.03%-0.06%). We report the case of a 72-year-old male patient with persistent sciatic artery suffering from pain at rest and an ulcer on the left first toe. Angiography findings showed 90% stenosis in the distal persistent sciatic artery. Endovascular therapy was considered difficult because of a long stenotic lesion from the persistent sciatic artery to the popliteal artery and extremely high calcification of the whole body. Because of poor blood flow to the lower leg, vascular prosthesis would have increased the risk of thrombotic occlusion. Therefore, below-knee femoropopliteal bypass using the great saphenous vein graft was performed, which led to the healing of the ulcer on the left first toe. Contrast-enhanced computed tomography of the lower limbs was performed to confirm that the bypass blood flow was good. The patient was discharged on postoperative day 5.

Utility of a corticotropin-releasing hormone test to differentiate pituitary-dependent hyperadrenocorticism from cortisol-producing adrenal tumors in dogs.

BACKGROUND: Hyperadrenocorticism (HAC) is a common endocrine disorder in dogs; however, there are no reports on the use of the corticotropin-releasing hormone test (CRHT) to differentiate between pituitary-dependent hyperadrenocorticism (PDH) and cortisol-producing adrenal tumors (CPATs), both causative of HAC. OBJECTIVES: To evaluate the usefulness of CRHT as a tool to differentiate between PDH and CPAT in dogs and to determine the reference intervals for CRHT in healthy, PDH, and CPAT dogs. ANIMALS: Dogs diagnosed with PDH (n = 21), CPAT (n = 6), and healthy beagle dogs (n = 33). METHODS: This prospective study included dogs with a definitive diagnosis of PDH and CPAT and healthy beagle dogs, in which CRHT was performed, were prospectively evaluated. We investigated the correlations of CRHT (endogenous adrenocorticotropic hormone [ACTH] concentration, endogenous ACTH concentration [EAC], and poststimulation ACTH concentration [PAC]) with pituitary-to-brain ratio (PBR) (in PDH) and with indices of adrenal ultrasonography (smaller and larger adrenal gland dorsoventral thickness in PDH and CPAT). RESULTS: For EAC, the area under the curve (AUC) was 0.95, with a cutoff value of 26.3 pg/mL (sensitivity: 90.62%, specificity: 87.50%). The AUC for PAC was 0.96 with a cutoff value of 54.5 pg/mL (sensitivity: 100.00%, specificity: 66.67%). The 95% reference interval for CRHT in healthy (control) dogs ranged 5.00 to 79.8 pg/mL (1.10-17.57 pmol/L) for EAC, and 1.92 to 153.42 pg/mL (0.42-33.78 pmol/L) for PAC. There was no significant correlation between PBR and CRHT, nor adrenal size and CRHT. CONCLUSIONS AND CLINICAL IMPORTANCE: CRHT appears to be a rapid and reliable test for differentiating PDH from CPAT in dogs.

Serous Membrane Detachment with Ultrasonic Homogenizer Improves Engraftment of Fetal Liver to Liver Surface in a Rat Model of Cirrhosis.

Liver transplantation is the most effective treatment for end-stage cirrhosis. However, due to serious donor shortages, new treatments to replace liver transplantation are sorely needed. Recent studies have focused on novel therapeutic methods using hepatocytes and induced pluripotent stem cells, we try hard to develop methods for transplanting these cells to the liver surface. In the present study, we evaluated several methods for their efficiency in the detachment of serous membrane covering the liver surface for transplantation to the liver surface. The liver surface of dipeptidyl peptidase IV (DPPIV)-deficient rats in a cirrhosis model was detached by various methods, and then fetal livers from DPPIV-positive rats were transplanted. We found that the engraftment rate and area as well as the liver function were improved in rats undergoing transplantation following serous membrane detachment with an ultrasonic homogenizer, which mimics the Cavitron Ultrasonic Surgical Aspirator® (CUSA), compared with no detachment. Furthermore, the bleeding amount was lower with the ultrasonic homogenizer method than with the needle and electric scalpel methods. These findings provide evidence that transplantation to the liver surface with serous membrane detachment using CUSA might contribute to the development of new treatments for cirrhosis using cells or tissues.

A Novel Orthotopic Liver Cancer Model for Creating a Human-like Tumor Microenvironment.

Hepatocellular carcinoma (HCC) is the most common form of liver cancer. This study aims to develop a new method to generate an HCC mouse model with a human tumor, and imitates the tumor microenvironment (TME) of clinical patients. Here, we have generated functional, three-dimensional sheet-like human HCC organoids in vitro, using luciferase-expressing Huh7 cells, human iPSC-derived endothelial cells (iPSC-EC), and human iPSC-derived mesenchymal cells (iPSC-MC). The HCC organoid, capped by ultra-purified alginate gel, was implanted into the disrupted liver using an ultrasonic homogenizer in the immune-deficient mouse, which improved the survival and engraftment rate. We successfully introduced different types of controllable TME into the model and studied the roles of TME in HCC tumor growth. The results showed the role of the iPSC-EC and iPSC-MC combination, especially the iPSC-MC, in promoting HCC growth. We also demonstrated that liver fibrosis could promote HCC tumor growth. However, it is not affected by non-alcoholic fatty liver disease. Furthermore, the implantation of HCC organoids to humanized mice demonstrated that the immune response is important in slowing down tumor growth at an early stage. In conclusion, we have created an HCC model that is useful for studying HCC development and developing new treatment options in the future.

Relationship between anti-insulin antibody production and severe insulin resistance in a diabetic cat.

A 5-year-old castrated male domestic shorthair cat was diagnosed with diabetic ketoacidosis and severe insulin resistance. Although the conventional treatment for diabetic ketoacidosis was provided, the cat required frequent hospitalization because of severe dehydration and repeated diabetic ketoacidosis. We detected anti-insulin antibodies for human in this cat. Serum insulin-binding IgG levels were markedly elevated compared with those in healthy cats and other diabetic cats. We initiated prednisolone to suppress the effects of anti-insulin antibodies. After initiation of prednisolone, the cat was gradually recovered with increasing activity and appetite. Furthermore, satisfactory glycemic control was achieved with combined subcutaneous injection of insulin detemir and insulin degludec.

Establishment of Human Leukocyte Antigen-Mismatched Immune Responses after Transplantation of Human Liver Bud in Humanized Mouse Models.

Humanized mouse models have contributed significantly to human immunology research. In transplant immunity, human immune cell responses to donor grafts have not been reproduced in a humanized animal model. To elicit human T-cell immune responses, we generated immune-compromised nonobese diabetic/Shi-scid, IL-2RγKO Jic (NOG) with a homozygous expression of human leukocyte antigen (HLA) class I heavy chain (NOG-HLA-A2Tg) mice. After the transplantation of HLA-A2 human hematopoietic stem cells into NOG-HLA-A2Tg, we succeeded in achieving alloimmune responses after the HLA-mismatched human-induced pluripotent stem cell (hiPSC)-derived liver-like tissue transplantation. This immune response was inhibited by administering tacrolimus. In this model, we reproduced allograft rejection after the human iPSC-derived liver-like tissue transplantation. Human tissue transplantation on the humanized mouse liver surface is a good model that can predict T-cell-mediated cellular rejection that may occur when organ transplantation is performed.

Relationship between anti-insulin antibody production and severe insulin resistance in a diabetic cat.

A 5-year-old castrated male domestic shorthair cat was diagnosed with diabetic ketoacidosis and severe insulin resistance. Although the conventional treatment for diabetic ketoacidosis was provided, the cat required frequent hospitalization because of severe dehydration and repeated diabetic ketoacidosis. We detected anti-insulin antibodies for human in this cat. Serum insulin-binding IgG levels were markedly elevated compared with those in healthy cats and other diabetic cats. We initiated prednisolone to suppress the effects of anti-insulin antibodies. After initiation of prednisolone, the cat was gradually recovered with increasing activity and appetite. Furthermore, satisfactory glycemic control was achieved with combined subcutaneous injection of insulin detemir and insulin degludec.