Roadmap to resuming care for liver diseases after coronavirus disease-2019.

The global pandemic of coronavirus disease-2019 (COVID-19) has led to significant disruptions in healthcare delivery. Patients with chronic liver diseases require a high level of care and are therefore particularly vulnerable to disruptions in medical services during COVID-19. Recent data have also identified chronic liver disease as an independent risk factor for COVID-19 related hospital mortality. In response to the pandemic, national and international societies have recommended interim changes to the management of patients with liver diseases. These modifications included the implementation of telehealth, postponement or cancelation of elective procedures, and other non-urgent patient care-related activities. There is concern that reduced access to diagnosis and treatment can also lead to increased morbidity in patients with liver diseases and we may witness a delayed surge of hospitalizations related to decompensated liver disease after the COVID-19 pandemic has receded. Therefore, it is paramount that liver practices craft a comprehensive plan for safe resumption of clinical operations while minimizing the risk of exposure to patients and health-care professionals. Here, we provide a broad roadmap for how to safely resume care for patients with chronic liver disease according to various phases of the pandemic with particular emphasis on outpatient care, liver transplantation, liver cancer care, and endoscopy.

Challenges and Outcomes of the First Stem Cell Transplant Program in Tanzania, East Africa.

Introduction: Due to the significant resources involved in creating HSCT programs there is a significant disparity in the availability of this treatment modality between the developed and developing countries. This manuscript details the process and the outcomes of the first HSCT program in East Africa which was started at Muhimbili National Hospital (MNH) in Dar-es-Salaam, Tanzania. Materials and Methods: Information and data were collected on the processes which had been implemented for starting the HSCT program at MNH. The details of the collaborations, training, infrastructure development, and acquisition of the biomedical equipment, as well as the actual process for HSCT, as well as the outcomes of treatment are described. Observations. The project has been detailed in 4 stages for ease of description: Stage 1: Preparatory work which was performed by the Government of Tanzania, as well as the administrators and clinicians from MNH (July 2017-September 2021). Stage 2: Exploratory gap analysis by the teams from MNH and International Haematology Consortium of HCG Hospital, India (HCG-IHC) in October 2021. Stage 3: Activities for closure of gaps (November 2021). Stage 4: Stem Cell Transplantation Camps (November 2021 to March 2022). 11 peripheral blood stem cell transplants were done in two camps, November 2021 (5 patients), and February 2022 (6 patients). 10 patients underwent autologous peripheral blood stem cell transplantation for multiple myeloma and 1 for lymphoma. The median duration of hospital stay was 19 ± 6 days. The median time for neutrophil engraftment, it was on 8.8 ± 0.8 days, and for platelet engraftment was 9.6 ± 2.4 days. Progression-free survival was 100%, and there was no mortality. Conclusion: Commonalities in the socioeconomic challenges in developing countries can be leveraged to create robust HSCT programs in other developing countries.

Adipose-derived mesenchymal stromal cells from genetically modified pigs: immunogenicity and immune modulatory properties.

BACKGROUND AIMS: The immunomodulatory and anti-inflammatory effects of mesenchymal stromal cells (MSC) could prove to be a potential therapeutic approach for prolongation of survival of cell xenotransplantation. Adipose (Ad) MSC from genetically modified pigs could be an abundant source of pig donor-specific MSC. METHODS: Pig (p) MSC were isolated from adipose tissue of α1,3-galactosyltransferase gene knock-out pigs transgenic for human (h) CD46 (GTKO/hCD46), a potential source of islets. After characterization with differentiation and flow cytometry (FCM), AdMSC were compared with bone marrow (BM) MSC of the same pig and human adipose-derived (hAd) MSC. The modulation of human peripheral blood mononuclear cell (hPBMC) responses to GTKO pig aortic endothelial cells (pAEC) by different MSC was compared by measuring 3H-thymidine uptake. The supernatants from the AdMSC cultures were used to determine the role of soluble factors. RESULTS: GTKO/hCD46 pAdMSC (i) did not express galactose-α1,3-galactose (Gal) but expressed hCD46, (ii) differentiated into chondroblasts, osteocytes and adipocytes, (iii) expressed stem cell markers, (iv) expressed lower levels of Swine Leucocyte Antigen I (SLAI), Swine Leucocyte Antigen II DR (SLAIIDR) and CD80 than pAEC before and after pig interferon (IFN)-γ stimulation. The proliferative responses of hPBMC to GTKO/hCD46 pAdMSC and hAdMSC stimulators were similar, and both were significantly lower than to GTKO pAEC (P < 0.05). The proliferation of hPBMC to GTKO pAEC was equally suppressed by GTKO/hCD46 pAdMSC and hAdMSC (P > 0.05). The supernatant from GTKO/hCD46 pAdMSC did not suppress the human xenoresponse to GTKO pAEC, which was cell-cell contact-dependent. CONCLUSIONS: Initial evidence suggests that genetically modified pAdMSC function across the xenogeneic barrier and may have a role in cellular xenotransplantation.

A Prospective Study on Assessment of Microbial Contamination of Toothbrushes and Methods of Their Decontamination.

BACKGROUND: Toothbrushes may get contaminated by the oral cavity, environment, hands, storage containers, or aerosol contamination. The present study was conducted to assess the microbial contamination of toothbrushes and methods of their decontamination. MATERIALS AND METHODS: The current study included 160 subjects of both genders. All the subjects were provided with a toothbrush and paste with complete hygiene instructions for the oral cavity. After one month, all the brushes were collected. The samples were categorized into four groups of 40 each. Group I was treated with 0.2% chlorhexidine gluconate, group II with Listerine, group III with Dettol, and group IV with tap water. Finally, these toothbrushes were placed in 5 mL of neutralizer broth and then evaluated to study the efficacy of four disinfectants. All the data were analyzed using the statistical package for social science (SPSS) version 23 software (IBM, Armonk, NY, USA). For all analyses, p < 0.05 was considered to be statistically significant Results: Aerobic bacterial growth before disinfection in Groups I, II, III, and IV was 91.6%, 75.84%, 75%, 81.67%, respectively (p = 0.01). After disinfecting the brushes aerobic bacterial growth was reduced to 34.17%, 30.84%, 24.17% & 74.17% in Groups I, II, III, and IV, respectively (p = 0.002). Klebsiella, Micrococci and Escherichia coli survived the most even after disinfection was done. CONCLUSION: Most effective agent for the disinfection of toothbrushes was Dettol followed by Listerine and 0.2% chlorhexidine gluconate. Tap water was found to be ineffective in the decontamination of toothbrushes.

Genetically-modified pig mesenchymal stromal cells: xenoantigenicity and effect on human T-cell xenoresponses.

BACKGROUND: Mesenchymal stromal cells (MSC) are being investigated as immunomodulatory therapy in the field of transplantation, particularly islet transplantation. While MSC can regenerate across species barriers, the immunoregulatory influence of genetically modified pig MSC (pMSC) on the human and non-human primate T-cell responses has not been studied. METHODS: Mesenchymal stromal cells from wild-type (WT), α1,3-galactosyltransferase gene knockout (GTKO) and GTKO pigs transgenic for the human complement-regulatory protein CD46 (GTKO/CD46) were isolated and tested for differentiation. Antibody binding and T-cell responses to WT and GTKO pMSC in comparison with GTKO pig aortic endothelial cells (pAEC) were investigated. The expression of swine leukocyte antigen (SLA) class II (SLA II) was tested. Costimulatory molecules CD80 and CD86 mRNA levels were measured. Human T-cell proliferation and the production of pro-inflammatory cytokines in response to GTKO and GTKO/CD46 pMSC in comparison with human MSC (hMSC) were evaluated. RESULTS: α1,3-galactosyltransferase gene knockout and GTKO/CD46 pMSC isolation and differentiation were achieved in vitro. Binding of human antibodies and T-cell responses were lower to GTKO than those to WT pMSC. Human and baboon (naïve and sensitized) antibody binding were significantly lower to GTKO pMSC than to GTKO pAEC. Before activation, <1% of GTKO pMSC expressed SLA II, compared with 2.5% of GTKO pAEC. After pig interferon-gamma (pIFN-γ) activation, 99% of GTKO pAEC upregulated SLA II expression, compared with 49% of GTKO pMSC. Only 3% of GTKO pMSC expressed CD80 compared with 80% of GTKO pAEC without activation. After pIFN-γ activation, GTKO pAEC upregulated CD86 mRNA level stronger than GTKO pMSC. The human CD4(+) T-cell response to GTKO pMSC was significantly weaker than that to GTKO pAEC, even after pIFN-γ activation. More than 99% of GTKO/CD46 pMSC expressed hCD46. Human peripheral blood mononuclear cells and CD4(+) T-cell responses to GTKO and GTKO/CD46 pMSC were comparable with those to hMSC, and all were significantly lower than to GTKO pAEC. GTKO/CD46 pMSC downregulated human T-cell proliferation as efficiently as hMSC. The level of proinflammatory cytokines IL-2, IFN-γ, TNF-α, and sCD40L correlated with the downregulation of T-cell proliferation by all types of MSC. CONCLUSION: Genetically modified pMSC is significantly less immunogenic than WT pMSC. GTKO/CD46 pMSC downregulates the human T-cell responses to pig antigens as efficiently as human MSC, which can be advantageous for therapeutic cell xenotransplantation.

Therapeutic issues in the treatment of vascularized xenotransplants using gal-knockout donors in nonhuman primates.

PURPOSE OF REVIEW: Solid organ xenotransplantation could be the future of transplantation, but improved outcomes are required in experimental models before clinical trials are justified. This review summarizes recent advances in solid organ xenotransplantation using organs from α1,3-galactosyltransferase gene-knockout (GTKO) pigs (with or without other genetic modifications) and novel therapeutic approaches. RECENT FINDINGS: Work on the development of genetically engineered pigs has been considerable during the past few years, with many research institutes reporting the outcomes of research. Multiple gene modifications on a GTKO background have been reported, and the results of transplantation using organs from these pigs have been published. Progress, however, has been variable, and several obstacles, for example, coagulation dysregulation, have been identified. Heterotopic pig heart xenotransplantation has been associated with graft survival up to 8 months, but kidney graft survival has not improved significantly. SUMMARY: The availability of GTKO pigs with additional genetic modifications aimed toward expression of multiple complement-regulatory proteins and/or human thromboregulatory genes, combined with novel immunosuppressive regimens, for example, the inclusion of B cell-depleting agents, should improve pig organ survival in the near future.

Accelerated reliability testing of Cu-Al bimetallic contact by a micropattern corrosion testing platform for wire bond device application.

Accelerated reliability testing of integrated circuit (IC) packages, such as wire-bonded devices, is a useful tool for predicting the lifetime corrosion behavior of real-world devices. Standard tests, such as highly accelerated stress test, involves subjecting an encapsulated device to high levels of humidity and high temperature (commonly 85-121 °C and 85-100% relative humidity). A major drawback of current reliability tests is that mechanistic information of what occurs between t = 0 and device failure is not captured. A novel method of in-situ investigation of the device corrosion process was developed to capture the real time mechanistic information not obtained in standard reliability testing [1]. The simple, yet effective methodology involves:•Immersing a micropattern or device directly into contaminant-spiked aqueous solution, and observing its morphological changes under optical microscope paired with a camera.•Short (2-48 h) time required for testing (compared to 24-300 h of standard tests).•No need for humidity chambers.

Technique of endoscopic biopsy of islet allografts transplanted into the gastric submucosal space in pigs.

Currently, islet cells are transplanted into the liver via portal vein infusion. One disadvantage of this approach is that it is not possible to adequately biopsy the islets in the liver to assess for rejection. Islet transplantation (Tx) into the gastric submucosal space (GSMS) can be performed endoscopically and has the potential advantage of histological evaluation by endoscopic biopsy. The aim of this study was to determine whether a representative allograft sample could be obtained endoscopically. We performed islet Tx into the GSMS in nonimmunosuppressed pigs using simple endoscopic submucosal injection. Islets were transplanted at four sites. Endoscopic ultrasonography and biopsy of the transplanted islets at two sites by modified endoscopic submucosal dissection were carried out successfully in all pigs 5 days after islet Tx. Tissue obtained at both biopsy and necropsy (including full-thickness sections of the gastric wall around the sites of the remaining islets and biopsies) were examined by histology and immunohistochemistry to confirm the presence of the islet grafts and any features of rejection. Representative allograft sampling was successfully obtained from all biopsy sites. All biopsies included islets with insulin-positive staining. There was significant CD3(+) and CD68(+) cell infiltration in the islet masses obtained at biopsy and from sections taken at necropsy, with similar histopathological features. Endoscopic biopsy of islet allografts in the GSMS is feasible, provides accurate histopathological data, and would provide a significant advance if translated into clinical practice.

Is there a correlation between anti-pig antibody levels in humans and geographic location during childhood?

BACKGROUND: An initial observation suggested high levels of anti-pig antibodies in healthy humans who had spent their childhood in the Middle East. We tested larger cohorts to determine whether anti-pig antibody levels correlated with the geographic location in which the subject spent his/her childhood, because this might have implications for clinical trials of xenotransplantation. METHODS: Anti-pig IgM and IgG levels (by flow cytometry using peripheral blood mononuclear cells from wild-type and α1,3-galactosyltransferase gene-knockout pigs) and anti-Gal IgM and IgG levels (by enzyme-linked immunosorbent assay) were measured in 75 volunteers. Comparisons of antibody levels were also made based on subject age, gender, ABO blood group, diet, and history of vaccination. RESULTS: Antibody binding to α1,3-galactosyltransferase gene-knockout pig cells was less than to wild-type cells. There was a reduction in anti-pig IgM and anti-Gal IgM, but a slight increase in anti-nonGal IgG, with age. Women had higher levels of anti-Gal IgM than men. Blood group A subjects had higher levels of anti-pig IgM and IgG than those of group AB. Diet had no influence on antibody levels. Typhoid or measles-mumps-rubella vaccination was associated with lower anti-nonGal IgG or anti-Gal IgG, respectively, whereas influenza vaccination was associated with higher anti-nonGal IgG. There were some significant variations in antibody levels associated with location during childhood, with subjects from the Middle East demonstrating higher anti-nonGal IgG and anti-Gal IgG. CONCLUSION: Clinical trials of xenotransplantation may be influenced by various factors, including the geographic location of the recipient during childhood, possibly associated with exposure to different microorganisms.