Divergent effects of chronic HIV-1 infection on human thymocyte maturation in SCID-hu mice

We have recently developed a modified SCID-hu mouse model in which the implanted human thymus and liver (hu-thy/liv) and human peripheral T cells become infected with HIV-1 after i.p. inoculation. By using this model, we evaluated the effect of HIV-1 infection on thymic maturation and observed that different HIV-1 strains had divergent effects of thymic maturation. Although minimal effects on continued thymopoiesis in the hu-thy/liv implant were observed after chronic infection with two primary patient isolates, HIV-1(28) and HIV-1(59), and with HIV-1ADA, HIV-1Ba-L, HIV-1JR-CSF, HIV-1JR-FL, and HIV-1SF162, significant thymocyte depletion was detected after infection with HIV-1IIIB and HIV-1RF. Thus, the effect of HIV-1 infection on thymocyte maturation may depend upon the strain of HIV-1 infecting the thymus. Despite the minimal effects on thymopoiesis observed in the hu-thy/liv implanted in SCID-hu mice 6 mo after infection with HIV-1(28), significant changes were seen in the human T cell population circulating in the peripheral blood of these mice. These changes ranged from an inversion of the CD4/CD8 ratio of peripheral human T cells in some SCID-hu mice to the almost complete depletion of peripheral human T cells observed in other SCID-hu mice. Because these effects were associated with the detection of HIV-1 infection of the peripheral human T cells, these modified SCID-hu mice should prove to be a valuable model for investigating the effects of chronic HIV-1 infection on the peripheral human T cell population.

The Number of Positive Lymph Nodes as Prognostic Factor in ypN1 Breast Cancer with Neoadjuvant Chemotherapy

PURPOSE/OBJECTIVE(S)

This study aimed to assess the ability of the number of positive lymph nodes (LNP) after neoadjuvant chemotherapy (NAC) to stratify prognosis even within the same ypN stage in breast cancer patients.

MATERIALS/METHODS

A 6,443 non-metastatic breast cancer patients with ypN1 disease after NAC following primary surgery were identified using the stage, stage evaluation field, treatment fields from Surveillance Epidemiology and End Results (SEER) database. Survival analysis was performed for overall survival (OS) using Kaplan-Meier plot and Cox proportional hazard models.

RESULTS

Of patients, 1,132(17.6%) had 3 positive lymph nodes (LNP3), 4,363 (67.7%) patients were T1/2 stage and 538 (8.35%) patients were downstage after treatment. LNP3 group had a significantly worse OS than LNP1/2 group (5yr OS, 74.2% vs. 80.9%, p <0.001). Similar results were observed in cause specific survival analysis (5yr OS, 79.8% vs. 85.2%, p <0.001). In subgroup analysis, there was a significant difference in OS between LNP1/2 and LNP3 group for HER2 or triple negative subtype, (p <0.001), T1/2 stage (p <0.001) and stable/downstage of N stage (p <0.001 and 0.019, respectively), but not for luminal A/B subtype and T3/4 (p = 0.126, 0.629 and 0.154, respectively). Regarding the number of examined lymph node (LNE), OS was significantly decreased in patients with LNE ≤5 in LNP3 group (p <0.001) but not in LNP1/2 group. In multivariable analysis, the prognostic significance of LNP3 remained (p <0.001) and the following factors were significantly related to the prolonged OS; Luminal A/B (p<0.001 and 0.001, respectively), T1/2 stage (p <0.001), N1 stage (p <0.001), LNE (≤5 vs. >5, p = 0.001) and receipt of radiotherapy (p = 0.012). Even when PS matching was performed, the OS of LNP was worse than that of LNP1/2.

CONCLUSION

LNP could more stratify the patients with ypN1 breast cancer after NAC. LNP3 is significantly associated with OS even after adjusting for other prognosticators. In particular, since there is a potential difference in the magnitude of the impact of LNP3 according to LNE, it is necessary to consider both of them together for decision-making.

First Exclusive Measurement of Deeply Virtual Compton Scattering off ^{4}He: Toward the 3D Tomography of Nuclei

We report on the first measurement of the beam-spin asymmetry in the exclusive process of coherent deeply virtual Compton scattering off a nucleus. The experiment uses the 6 GeV electron beam from the Continuous Electron Beam Accelerator Facility (CEBAF) accelerator at Jefferson Lab incident on a pressurized ^{4}He gaseous target placed in front of the CEBAF Large Acceptance Spectrometer (CLAS). The scattered electron is detected by CLAS and the photon by a dedicated electromagnetic calorimeter at forward angles. To ensure the exclusivity of the process, a specially designed radial time projection chamber is used to detect the recoiling ^{4}He nuclei. We measure beam-spin asymmetries larger than those observed on the free proton in the same kinematic domain. From these, we are able to extract, in a model-independent way, the real and imaginary parts of the only ^{4}He Compton form factor, H_{A}. This first measurement of coherent deeply virtual Compton scattering on the ^{4}He nucleus, with a fully exclusive final state via nuclear recoil tagging, leads the way toward 3D imaging of the partonic structure of nuclei.

Protective effect of a brown algae, Sargassum horneri on particulate matter-induced oxidative stress and inflammation in MLE-12 cells

The constant exposure to fine particulate matter (PM) induces oxidative stress and proinflammatory cytokine production. The ROS formed by oxidative stress is related to activate NF-κB signal pathway for inflammation. Sargassum horneri, a brown algae found in East Asia, is known to be an excellent source for bioactive components. In this study, the antioxidant and anti-inflammation effects of Sargassum horneri ethanol extract (SHE) on the PM-induced oxidative stress in MLE-12, a type II alveolar epithelial cell line were investigated. As the exposure concentration of PM increased to 1,000 μg/mL, the cell viability was reduced; however, it was increased when treated with SHE. The ROS generation and lipid peroxidation of MLE-12 cells were increased from the PM concentration of 125 μg/mL and they were reduced after treatment of SHE at 62.5 and 125 μg/mL. The expressions of antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD2), in MLE-12 cells exposed to PM were lower than those exposed to PM with SHE. The PM was proved to increase the expression of 8-OHdG, one of DNA oxidative damage markers, and OGG1, the repair enzyme of 8-OHdG, while SHE protected the DNA damage of cell. The expression of NF-κB signaling was reduced by SHE. These results suggest that SHE can adjust the expression of antioxidant enzymes, help to suppress the oxidative stress induced by PM, and attenuate its oxidative damage and NF-κB pathway to lung epithelial cells by eliminating over-produced ROS.

This research is part of a project titled ‘Development of functional food products with natural materials derived from marine resources’ funded by the Ministry of Oceans and Fisheries, Republic of Korea in 2017 (Project NO. 20172085).

Remote Monitoring of Heart Transplant Recipients during the COVID-19 Pandemic

Purpose

The COVID-19 pandemic created significant challenges in monitoring heart transplant (HT) recipients for rejection due to efforts to minimize contact with the hospital setting. The aim of this study was to evaluate the safety and efficacy of transitioning HT patients to home phlebotomy and a monitoring protocol based on gene expression profiling (GEP) and donor derived cell free DNA (ddcfDNA).

Methods

A single-center cohort study that prospectively enrolled consecutive HT patients who were transitioned to a remote monitoring protocol employing home phlebotomy and non-invasive surveillance for rejection. Patients were enrolled starting at 2 months post-HT. Positive GEP values were defined as ≥32 (up to 6 months post-HT) and ≥34 (> 6 months post-HT). A positive ddcfDNA score was defined as >0.12%. A positive biopsy was defined as grade ≥1B/1R

Results

246 HT patients were enrolled and followed for a minimum of 3 months. Mean age was 56±14, 71.5% were male, and median time from transplant was 2.7 years. The average distance of patients from the hospital was 25.6 miles. 359 blood tests were drawn for detection of GEP and ddcfDNA and 102 biopsies performed (Figure). Among 32 patients who had negative results on both tests and had a biopsy, 0 had a positive biopsy. Of 25 patients who had positive results on both tests and had a biopsy, 3 (12%) had a positive biopsy. The biopsy positivity rate in patients who were GEP+/ddcfDNA- was 6% and in patients who were GEP-/ddcfDNA+ was 8%. None of the positive biopsies were associated with hemodynamic compromise. 15 (6%) of patients were admitted due to allograft rejection during the study period. There were no deaths.

Conclusion

Using a remote monitoring protocol with home phlebotomy and noninvasive rejection surveillance was feasible and safe in HT recipients. In this cohort, the combination of negative GEP and ddcfDNA scores was accurate at predicting a lack of allograft rejection.

Tensor correlations measured in 3He(e,e' pp)n

We have measured the 3He(e,e' pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum p(tot). For pair relative momenta between 0.3 and 0.5  GeV/c, the ratio is very small at low p(tot) and rises to approximately 0.5 at large p(tot). This shows the dominance of tensor over central correlations at this relative momentum.

Perforated appendicitis within an inguinal hernia: case report and review of the literature

The finding of the vermiform appendix within an inguinal hernia sac is not uncommon. However, it is rare to find a perforated appendix within an inguinal hernia. An unusual case of an incarcerated and perforated appendix within an inguinal hernia complicated by an intra-abdominal abscess is reported herein. Perforated appendix as a cause of abscess was revealed during abdominal exploration. Clinicians are encouraged to be aware of this unusual entity, which is rarely recognized before exploration.