Fecal metabarcoding of the endangered Pacific pocket mouse (Perognathus longimembris pacificus) reveals a diverse and forb rich diet that reflects local habitat availability.

Information on diet breadth and preference can assist in understanding links between food resources and population growth and inform habitat restoration for rare herbivores. We assessed the diet of the endangered Pacific pocket mouse using metabarcoding of fecal samples and compared it to plant community composition in long-term study plots in two populations on Marine Corps Base Camp Pendleton, San Diego County, CA. Fecal samples (n = 221) were collected between spring 2016 and fall 2017 during monthly live-trap surveys. Concurrently, percent cover and plant phenology were measured in plots centered on trap locations. Fecal samples were sequenced with paired-end reads of the internal transcribed spacer 2 region of the nuclear ribosomal gene, and the resulting amplicons were matched to a regionally specific database. Seventy-three plant taxa were detected, which were mostly forbs and perennial herbs (70-90%). Diet composition differed between populations, years, seasons, and plots. Overall, diet and local habitat composition in plots were significantly correlated. However, we detected some differences in above-ground seed availability and proportion in fecal samples that indicate diet preferences for some forbs, perennial herbs, and native bunch grasses over perennial shrubs and non-native grasses. This is the first study of PPM to pair plant phenology surveys with diet metabarcoding to estimate resource selection, and results suggest that managing habitat for diverse native forb communities and reducing non-native grass cover may be beneficial for this critically endangered species.

Diversity of the National Medical Student Body - Four Decades of Inequities.

A racially and ethnically diverse health care workforce remains a distant goal, the attainment of which is contingent on the inclusivity of the national medical student body. We examined the diversity of medical school applicants and enrollees over the past four decades with an eye toward assessing the progress made. Data on the gender and race or ethnic group of enrollees in all medical doctorate degree-granting U.S. medical schools from 1978 through 2019 were examined. The percentage of female enrollees doubled during this period, and women now constitute more than half the national medical student body. This upturn has been attributed largely to an increase by a factor of 12 in the enrollment of Asian women. The corresponding decrease in the percentage of male enrollees, most notably White men, was offset by an increase by a factor of approximately 5 in the enrollment of Asian men. The percentages of enrollees from Black, Hispanic, and other racial and ethnic groups that are underrepresented in medicine remain well below the percentages of these groups in the national Census.

An unusual case of primary acinar cell carcinoma of the liver and its treatment.

Acinar cell carcinoma (ACC) is an epithelial neoplasm characterized by morphological features similar to acinar cells found in exocrine glands. Most cases of hepatic ACC reveal evidence of pancreatic exocrine enzyme production and are considered to be metastatic from the pancreas. However, a small number of hepatic ACC cases have been reported in which the tumor is believed to have originated in the liver rather than being a metastatic lesion. In this report we present a case of primary ACC of the liver. A 59-year-old female with no significant past medical history presented with the chief complaint of abdominal pain. A computed tomography (CT) scan of the abdomen showed innumerable mass lesions throughout the liver, initially concerning for metastatic disease. Histopathologic morphology was most consistent with that of ACC, possibly of pancreatic origin. However, the CA 19-9 level was not elevated and no pancreatic lesions were detected on the CT scan. Similar to a previously reported case, the diagnosis of primary ACC of the liver was made based on: acinar cells seen on histology, findings on immunohistochemical staining, radiographic images of liver masses, and the absence of extrahepatic lesions. Previous case reports of primary ACC have differing hypotheses regarding this rare finding. One hypothesis suggests an ectopic origin of acinar cells within the liver. An alternative hypothesis proposes that hepatic and pancreatic cells are ontogenetically derived from a common progenitor cell, which is thought to result in hepatic cells differentiating into acinar cells. The patient was treated with gemcitabine and paclitaxel every 2 weeks for 8 months and then transitioned to every 3 weeks for better tolerance. The patient's symptoms significantly improved within the first 6 weeks of treatment. At the time of the preparation of this report, it has been 17 months since initiation of therapy, and follow-up imaging continues to demonstrate a dramatic decrease in both size and number of hepatic nodules. ACC's are rare tumors that are usually found in glandular tissues. Primary ACC of the liver is extremely rare with only a few cases having been reported. This article adds to the limited literature available on primary hepatic ACC.

Complement 3 Receptor Expression in Individuals with Type 2 Diabetes.

BACKGROUND: According to the World Health Organization, as of 2014 9% of the world's adult population is affected by diabetes. Uncontrolled diabetes is a pro-inflammatory process that increases generation of reactive oxygen species (ROS). METHODS: The production of ROS leads to a chronic increase in oxidative stress which results in an increased susceptibility to infections. Individuals with type 2 diabetes mellitus (T2DM) are highly susceptible to Mycobacterium tuberculosis (M. tb) infection. Previous research has demonstrated that glutathione (GSH) plays an important role in the control of M. tb infection. Recent studies have demonstrated that phagocytosis of M.tb is diminished in patients with T2DM. Phagocytosis in macrophages is thought to be mediated in part by complement protein 3b (C3b)-complement protein receptor 3b (C3R) interactions. Since C3b production is not diminished in patients with T2DM we propose that C3R production is reduced and is the cause for impaired macrophage phagocytosis as well as IL-12 and IFN-γ signaling. CONCLUSION: This study utilizes a quantitative PCR (qPCR), demonstrating decreased transcription of C3R mRNA in patients with T2DM as compared to non-diabetics.

Liposomal Glutathione Supplementation Restores TH1 Cytokine Response to Mycobacterium tuberculosis Infection in HIV-Infected Individuals.

Cytokines are signaling biomolecules that serve as key regulators of our immune system. CD4(+) T-cells can be grouped into 2 major categories based on their cytokine profile: T-helper 1 (TH1) subset and T-helper 2 (TH2) subset. Protective immunity against HIV infection requires TH1-directed CD4 T-cell responses, mediated by cytokines, such as interleukin-1ß (IL-1ß), IL-12, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α). Cytokines released by the TH1 subset of CD4 T-cells are considered important for mediating effective immune responses against intracellular pathogens such as Mycobacterium tuberculosis (M. tb). Oxidative stress and redox imbalance that occur during HIV infection often lead to inappropriate immune responses. Glutathione (GSH) is an antioxidant present in nearly all cells and is recognized for its function in maintaining redox homeostasis. Our laboratory previously reported that individuals with HIV infection have lower levels of GSH. In this study, we report a link between lower levels of GSH and dysregulation of TH1- and TH2-associated cytokines in the plasma samples of HIV-positive subjects. Furthermore, we demonstrate that supplementing individuals with HIV infection for 13 weeks with liposomal GSH (lGSH) resulted in a significant increase in the levels of TH1 cytokines, IL-1ß, IL-12, IFN-γ, and TNF-α. lGSH supplementation in individuals with HIV infection also resulted in a substantial decrease in the levels of free radicals and immunosuppressive cytokines, IL-10 and TGF-ß, relative to those in a placebo-controlled cohort. Finally, we determined the effects of lGSH supplementation in improving the functions of immune cells to control M. tb infection by conducting in vitro assays using peripheral blood mononuclear cells collected from HIV-positive individuals at post-GSH supplementation. Our studies establish a correlation between low levels of GSH and increased susceptibility to M. tb infection through TH2-directed response, which may be relieved with lGSH supplementation enhancing the TH1 response.

Investigating the causes for decreased levels of glutathione in individuals with type II diabetes.

Tuberculosis (TB) remains an eminent global burden with one third of the world's population latently infected with Mycobacterium tuberculosis (M. tb). Individuals with compromised immune systems are especially vulnerable to M. tb infection. In fact, individuals with Type 2 Diabetes Mellitus (T2DM) are two to three times more susceptible to TB than those without T2DM. In this study, we report that individuals with T2DM have lower levels of glutathione (GSH) due to compromised levels of GSH synthesis and metabolism enzymes. Transforming growth factor beta (TGF-ß), a cytokine that is known to decrease the expression of the catalytic subunit of glutamine-cysteine ligase (GCLC) was found in increased levels in the plasma samples from individuals with T2DM, explaining the possible underlying mechanism that is responsible for decreased levels of GSH in individuals with T2DM. Moreover, increased levels of pro-inflammatory cytokines such as interleukin-6 (IL-6) and interleukin-17 (IL-17) were observed in plasma samples isolated from individuals with T2DM. Increased levels of IL-6 and IL-17 was accompanied by enhanced production of free radicals further indicating an alternative mechanism for the decreased levels of GSH in individuals with T2DM. Augmenting the levels of GSH in macrophages isolated from individuals with T2DM resulted in improved control of M. tb infection. Furthermore, cytokines that are responsible for controlling M. tb infection at the cellular and granuloma level such as tumor necrosis factor alpha (TNF-α), interleukin-1ß (IL-1ß), interleukin-2 (IL-2), interferon-gamma (IFN-γ), and interleukin-12 (IL-12), were found to be compromised in plasma samples isolated from individuals with T2DM. On the other hand, interleukin-10 (IL-10), an immunosuppressive cytokine was increased in plasma samples isolated from individuals with T2DM. Overall, these findings suggest that lower levels of GSH in individuals with T2DM lead to their increased susceptibility to M. tb infection.

Glutathione synthesis is compromised in erythrocytes from individuals with HIV.

We demonstrated that the levels of enzymes responsible for the synthesis of glutathione (GSH) such as glutathione synthase (GSS), glutamate-cysteine ligase-catalytic subunit (GCLC), and glutathione reductase (GSR) were significantly reduced in the red blood cells (RBCs) isolated from individuals with human immunodeficiency virus (HIV) infection and this reduction correlated with decreased levels of intracellular GSH. GSH content in RBCs can be used as a marker for increased overall oxidative stress and immune dysfunctions caused by HIV infection. Our data supports our hypothesis that compromised levels of GSH in HIV infected individuals' is due to decreased levels of GSH-synthetic enzymes. The role of GSH in combating oxidative stress and improving the functions of immune cells in HIV patients' indicates the benefit of an antioxidant supplement which can reduce the cellular damage and promote the functions of immune cells.

An elucidation of neutrophil functions against Mycobacterium tuberculosis infection.

We characterized the functions of neutrophils in response to Mycobacterium tuberculosis (M. tb) infection, with particular reference to glutathione (GSH). We examined the effects of GSH in improving the ability of neutrophils to control intracellular M. tb infection. Our findings indicate that increasing the intracellular levels of GSH with a liposomal formulation of GSH (L-GSH) resulted in reduction in the levels of free radicals and increased acidification of M. tb containing phagosomes leading to the inhibition in the growth of M. tb. This inhibitory mechanism is dependent on the presence of TNF-α and IL-6. Our studies demonstrate a novel regulatory mechanism adapted by the neutrophils to control M. tb infection.

Characterization of dendritic cell and regulatory T cell functions against Mycobacterium tuberculosis infection.

Glutathione (GSH) is a tripeptide that regulates intracellular redox and other vital aspects of cellular functions. GSH plays a major role in enhancing the immune system. Dendritic cells (DCs) are potent antigen presenting cells that participate in both innate and acquired immune responses against microbial infections. Regulatory T cells (Tregs) play a significant role in immune homeostasis. In this study, we investigated the effects of GSH in enhancing the innate and adaptive immune functions of DCs against Mycobacterium tuberculosis (M. tb) infection. We also characterized the functions of the sub-populations of CD4+T cells such as Tregs and non-Tregs in modulating the ability of monocytes to control the intracellular M. tb infection. Our results indicate that GSH by its direct antimycobacterial activity inhibits the growth of intracellular M. tb inside DCs. GSH also increases the expressions of costimulatory molecules such as HLA-DR, CD80 and CD86 on the cell surface of DCs. Furthermore, GSH-enhanced DCs induced a higher level of T-cell proliferation. We also observed that enhancing the levels of GSH in Tregs resulted in downregulation in the levels of IL-10 and TGF- ß and reduction in the fold growth of M. tb inside monocytes. Our studies demonstrate novel regulatory mechanisms that favor both innate and adaptive control of M. tb infection.

Glutathione supplementation improves macrophage functions in HIV.

In this study, we determined the effects of glutathione (GSH)-enhancing agents in restoring the levels of GSH in isolated macrophages from individuals with HIV infection thereby resulting in improved control of Mycobacterium tuberculosis. Our results indicate that treatment with N-acetyl cysteine or a liposomal formulation of glutathione (lGSH) resulted in replenishment of reduced also known as free GSH (rGSH), and correlated with a decrease in the intracellular growth of M. tuberculosis. Finally, we observed differences in the amount of the catalytic subunit of glutamine-cysteine ligase (GCLC), glutathione synthase, and glutathione reductase present in macrophages derived from healthy and HIV-infected individuals. These changes correlated with changes in free radicals as well as rGSH levels. Our results indicate that HIV infection leads to increased production of free radicals and decreased production of GCLC resulting in depletion of rGSH and this may lead, in part, to the loss of innate immune function observed in HIV patients. These findings represent a novel mechanism for control of M. tuberculosis infection, and a possible supplement to current HIV treatments.

Glutathione and infection.

BACKGROUND: The tripeptide γ-glutamylcysteinylglycine or glutathione (GSH) has demonstrated protective abilities against the detrimental effects of oxidative stress within the human body, as well as protection against infection by exogenous microbial organisms. SCOPE OF REVIEW: In this review we describe how GSH works to modulate the behavior of many cells including the cells of the immune system, augmenting the innate and the adaptive immunity as well as conferring protection against microbial, viral and parasitic infections. This article unveils the direct antimicrobial effects of GSH in controlling Mycobacterium tuberculosis (M. tb) infection within macrophages. In addition, we summarize the effects of GSH in enhancing the functional activity of various immune cells such as natural killer (NK) cells and T cells resulting in inhibition in the growth of M. tb inside monocytes and macrophages. Most importantly we correlate the decreased GSH levels previously observed in individuals with pulmonary tuberculosis (TB) with an increase in the levels of pro-inflammatory cytokines which aid in the growth of M. tb. MAJOR CONCLUSIONS: In conclusion, this review provides detailed information on the protective integral effects of GSH along with its therapeutic effects as they relate to the human immune system and health. GENERAL SIGNIFICANCE: It is important to note that the increases in the levels of pro-inflammatory cytokines are not only detrimental to the host due to the sequel that follow such as fever and cachexia, but also due to the alteration in the functions of immune cells. The additional protective effects of GSH are evident after sequel that follows the depletion of this antioxidant. This is evident in a condition such as Cystic Fibrosis (CF) where an increased oxidant burden inhibits the clearance of the affecting organism and results in oxidant-induced anti-protease inhibition. GSH has a similar protective effect in protozoans as it does in human cells. Thus GSH is integral to the survival of some of the protozoans because some protozoans utilize the compound trypanothione [T(SH)2] as their main antioxidant. T(SH)2 in turn requires GSH for its production. Hence a decrease in the levels of GSH (by a known inhibitor such as buthionine sulfoximine [BSO] can have adverse effects of the protozoan parasites. This article is part of a Special Issue entitled Cellular functions of glutathione.

Unveiling the mechanisms for decreased glutathione in individuals with HIV infection.

We examined the causes for decreased glutathione (GSH) in individuals with HIV infection. We observed lower levels of intracellular GSH in macrophages from individuals with HIV compared to healthy subjects. Further, the GSH composition found in macrophages from HIV(+) subjects heavily favors oxidized glutathione (GSSG) which lacks antioxidant activity, over free GSH which is responsible for GSH's antioxidant activity. This decrease correlated with an increase in the growth of Mycobacterium tuberculosis (M. tb) in macrophages from HIV(+) individuals. In addition, we observed increased levels of free radicals, interleukin-1 (IL-1), interleukin-17 (IL-17) and transforming growth factor-ß (TGF-ß) in plasma samples derived from HIV(+) individuals compared to healthy subjects. We observed decreased expression of the genes coding for enzymes responsible for de novo synthesis of GSH in macrophages derived from HIV(+) subjects using quantitative PCR (qPCR). Our results indicate that overproduction of proinflammatory cytokines in HIV(+) individuals lead to increased production of free radicals. This combined with the decreased expression of GSH synthesis enzymes leads to a depletion of free GSH and may lead in part to the loss of immune function observed in HIV patients.

Glutathione and adaptive immune responses against Mycobacterium tuberculosis infection in healthy and HIV infected individuals.

Glutathione (GSH), a tripeptide antioxidant, is essential for cellular homeostasis and plays a vital role in diverse cellular functions. Individuals who are infected with Human immuno deficiency virus (HIV) are known to be susceptible to Mycobacterium tuberculosis (M. tb) infection. We report that by enhancing GSH levels, T-cells are able to inhibit the growth of M. tb inside macrophages. In addition, those GSH-replenished T cell cultures produced increased levels of Interleukin-2 (IL-2), Interleukin-12 (IL-12), and Interferon-gamma (IFN-γ), cytokines, which are known to be crucial for the control of intracellular pathogens. Our study reveals that T lymphocytes that are derived from HIV infected individuals are deficient in GSH, and that this deficiency correlates with decreased levels of Th1 cytokines and enhanced growth of M. tb inside human macrophages.

Atherosclerosis: pathogenesis and increased occurrence in individuals with HIV and Mycobacterium tuberculosis infection.

Atherosclerosis is a leading cause of coronary heart disease and stroke. Since 1981, more than 980,000 cases of AIDS have been reported in the United States. According to the Centers for Disease Control, more than 1 million Americans may be infected with HIV. By killing or damaging CD4+ T cells of the body's immune system, HIV progressively destroys the body's ability to fight infections. People diagnosed with AIDS often suffer from life-threatening diseases caused by opportunistic infections such as tuberculosis. HIV-infected individuals have increased risks for atherosclerosis. This review summarizes the effects of oxidized low density lipoproteins in impairing macrophage functions in individuals with atherosclerosis (with and without HIV infection) thereby enhancing the susceptibility to Mycobacterium tuberculosis infection.

Calcium-dependent upregulation of E4BP4 expression correlates with glucocorticoid-evoked apoptosis of human leukemic CEM cells.

Glucocorticoid (GC)-evoked apoptosis of T-lymphoid cells is preceded by increases in the intracellular Ca2+ concentration ([Ca2+]i), which may contribute to apoptosis. This report demonstrates that GC-mediated upregulation of the bZIP transcriptional repressor gene, E4BP4, is dependent on [Ca2+]i levels, and correlates with GC-evoked apoptosis of GC-sensitive CEM-C7-14 cells. Calcium chelators EGTA and BAPTA reduced [Ca2+]i levels and protected CEM-C7-14 cells from Dex-evoked E4BP4 upregulation as well as apoptosis. In the GC-resistant sister clone, CEM-C1-15, Dex treatment did not induce [Ca2+]i levels, E4BP4 expression or apoptosis, however, the calcium ionophore A23187 restored Dex-evoked E4BP4 upregulation and apoptosis. CEM-C7-14 cells were more sensitive to GC-independent increases in [Ca2+]i levels by thapsigargin, and a corresponding increase in E4BP4 expression and cell death, compared to CEM-C1-15 cells, suggesting a direct correlation between [Ca2+]i levels, E4BP4 expression, and apoptosis.