Low alanine aminotransferase as a risk factor for chronic obstructive pulmonary disease in males

Alanine aminotransferase (ALT) levels reflect skeletal muscle volume and general performance, which are associated with chronic obstructive pulmonary disease (COPD) development and prognosis. This study aimed to investigate ALT levels as a risk factor for COPD development. This 13-year population-based retrospective observational cohort study included 422,452 participants for analysis. We classified groups according to the baseline ALT levels (groups 1-5: ALT (IU/L) < 10; 10-19; 20-29; 30-39; and ≥ 40, respectively). The incidence of COPD was the highest in group 1, decreasing as the group number increased in males, but not in females. The Cox regression analysis in males revealed that a lower ALT level, as a continuous variable, was a significant risk factor for COPD development [univariable, hazard ratio (HR): 0.992, 95% confidence interval (CI): 0.991-0.994; multivariable, HR: 0.998, 95% CI: 0.996-0.999]. In addition, COPD was more likely to develop in the lower ALT level groups (groups 1-4; < 40 IU/L), than in the highest ALT level group (group 5; ≥ 40 IU/L) (univariable, HR: 1.341, 95% CI: 1.263-1.424; multivariable, HR: 1.097, 95% CI: 1.030-1.168). Our findings suggest that males with low ALT levels should be carefully monitored for COPD development.

FEF25-75% Values in Patients with Normal Lung Function Can Predict the Development of Chronic Obstructive Pulmonary Disease

Purpose

The forced mid-expiratory flow (FEF_25-75%) value is a potentially sensitive marker of obstructive peripheral airflow. We aimed to assess whether FEF_25-75% can be an early predictor of chronic obstructive pulmonary disease (COPD).

Patients and Methods

Between July 1, 2007 and June 31, 2009, we identified 3624 patients who underwent a pulmonary function test (PFT) in Gangnam Severance Hospital. We selected 307 patients aged over 40 years without COPD who had normal PFT results at baseline and who had follow-up PFT records more than 1 year later. A FEF_25-75% z-score less than −0.8435 was considered low. We defined COPD as a forced expiratory volume in one second/forced vital capacity value of less than 0.7 before July 31, 2019.

Results

Among 307 patients, 91 (29.6%) had low FEF_25-75% at baseline. After 10 years, the incidence rate of COPD in the low FEF_25-75% group was significantly higher than that in the normal FEF_25-75% group (41.8% vs 7.4%; P-value<0.001). The Cox proportional hazard model showed that age (hazard ratio [HR] 1.09; P-value<0.001), smoking status (occasional smoker HR, 4.59; P-value<0.001 and long-term smoker HR, 2.18; P-value=0.023), and low FEF_25-75% (HR, 3.31; P-value<0.001) were predictive factors for the development of COPD.

Conclusion

The FEF_25-75% value in patients with normal lung function is a useful predictor for the development of COPD. We should carefully monitor patients who present with low FEF_25-75% values, even if they have normal lung function.

Prediction model for hyperprogressive disease in non-small cell lung cancer treated with immune checkpoint inhibitors

BACKGROUND

Hyperprogressive disease (HPD) is a paradoxical acceleration of tumor growth after immune checkpoint inhibitor (ICI) treatment. This study aimed to identify the risk factors and to present a predictive model for HPD in patients treated with ICIs.

METHODS

A total of 78 non-small cell lung cancer (NSCLC) cases, treated with at least two cycles of ICIs who underwent computed tomography (CT) for response assessment were recruited into the study from January 2016 to August 2019. HPD was defined by the following criteria: (i) time-to-treatment failure <2 months; (ii) a 50% increase in the sum of target lesion diameters; (iii) new development of at least two lesions in an already involved organ; (iv) appearance of a new organ lesion; and (v) a decrease in ECOG PS 2.

RESULTS

Of the 78 total patients, 15 (19.2%) had HPD. The risk factors of HPD were age; primary lesion size; and metastases in the contralateral lung, pleura, liver, and bone in multivariable logistic regression (odds ratio [OR]; 0.9038, 1.6619, 28.5913, 23.8264, 14.5711, and 20.1533, respectively, all P-values < 0.05). By using these risk factors, we developed a prediction model for HPD and the area under the receiver operating characteristic curve of the model was 0.9556 (95% confidence interval [CI]: 0.9133-0.9978).

CONCLUSIONS

HPD is relatively common and associated with a grave clinical outcome, requiring a careful monitoring in lung cancer patients treated with ICIs. Moreover, risk factors such as age, size of tumor and number of various metastatic lesions should be taken into consideration before ICI administration.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: Age, primary lesion size, and number of metastases are risk factors of HPD. HPD is strongly associated with poor prognosis. HPD during ICI use needs comprehensive monitoring.

WHAT THIS STUDY ADDS

This is the first study to develop a prediction model. The area under the curve of the prediction model for HPD was 0.9556.

Positive Effects of the National Cigarette Price Increase Policy on Smoking Cessation in South Korea

Background

In January 2015, South Korea's government raised the cigarette tax, and the retail price of cigarettes abruptly increased by 80% compared to the previous year. This research aimed to determine the effect of this increase on smoking cessation among South Korean smokers.

Methods

We analyzed data collected by the 2013–2015 South Korea National Health and Nutrition Examination Survey of 15,203 South Koreans over 19 years old using regression analysis. We examined the recent non-smoking period of nonsmoking people, prepared according to the survey, and analyzed the recent smoking cessation ratio.

Results

Among smokers, from 2013 to 2014, the smoking cessation rate was 7.2%, and it increased to 9.9% in 2015 after the increase in the cigarette tax. In 2015, the recent smoking cessation rate was higher among people over the age of 60 (odds ratio [OR], 2.67) compared to those between the ages of 40 and 49. The recent smoking cessation rate was higher among people with below elementary education (OR, 2.28) and above university education (OR, 1.94) compared to high school, higher for those with apartments (OR, 1.74) compared to general type residences, and higher among those with a household income in the low-middle quartile (Q2) (OR, 2.32) compared to the highest quartile (Q4).

Conclusion

This innovative policy including increase in cigarette prices affected smoking cessation, and its impact varied by sub-group of smokers in South Korea.

Presence of mEGFR ctDNA predicts a poor clinical outcome in lung adenocarcinoma

Background

Circulating tumor DNA (ctDNA) is a biomarker for the selection of target agents in various malignancies. In this study, we examined the effect of ctDNA presence on the response to EGFR‐tyrosine kinase inhibitor (TKI) and on the prognosis in lung adenocarcinoma.

Methods

ctDNA of EGFR‐TKI sensitizing mutations (mEGFR), L858R substitution and Exon 19 deletion (E19d) mutation, was evaluated using droplet digital PCR (ddPCR) in 81 patients with lung adenocarcinoma which harbored mEGFR in the corresponding tumor tissues.

Results

The study recruited lung cancer patients at various stages, and the sensitivity, specificity, and area under the curve (AUC) of mEGFR ctDNA detection by ddPCR were 40.0%, 88.5%, and 0.68, respectively. It showed higher sensitivity (75.0% vs. 10.0%) and AUC (0.83 vs. 0.49) in the advanced stages of lung adenocarcinoma compared with the early stages and the number of metastases and the fractional abundance of mEGFR ctDNA showed a strong correlation (σ = 0.516; P < 0.001, Spearman correlation test). There was a significantly shorter progression‐free survival and duration of disease control by EGFR‐TKIs in the ctDNA‐positive group than the negative group (14.0 vs. 41.0 months, P = 0.02 and 12.0 vs. 23.0 months, P = 0.02, log‐rank test, respectively). There was a trend for overall survival time to be shorter in patients with mEGFR ctDNA than for patients without mEGFR ctDNA (35.6 vs. 67.1 months, P = 0.06, log‐rank test).

Conclusions

These data showed that mEGFR ctDNA detection using ddPCR is useful in the advanced stages and its presence predicted distant metastasis and poor clinical outcome in lung adenocarcinoma.

Morbidity and mortality of the Hartmann procedure for diverticular disease over 18 years in a single institution

AIM

Hartmann's procedure for perforated diverticulitis is associated with substantial morbidity and mortality. This study analyses factors associated with morbidity/mortality and possible changes over time.

METHOD

Patients treated by urgent Hartmann's procedure for perforated diverticulitis between 1992 and 2010 were studied, and information was collected on age, sex, perioperative details, 30-day morbidity and mortality recorded in an institutional review board approved database supplemented by chart review. Patients were divided into four groups based on the year of surgery. Univariate and multivariate logistic regression analysis was performed to identify risk factors associated with morbidity and mortality.

RESULTS

In all, 199 patients (51% female, mean age 65 years, mean body mass index 28 kg/m(2)) were identified. The American Society of Anesthesiologists (ASA) score was 4 in 30% of patients and Hinchey Stage IV in 16%. The mean length of stay was 12.5 ± 10 days. Mortality was 15% and did not change significantly over time. Overall morbidity was 52% and significantly increased over time on univariate analysis (P = 0.007) but not on multivariate analysis (P = 0.11). Independent predictors of morbidity on multivariate analysis were Hinchey IV (P < 0.001) and hypoproteinaemia (P = 0.001). Independent predictors for mortality were ASA > 3 (P = 0.01), abnormal creatinine (P = 0.007), steroid use (P = 0.007), Hinchey IV (P = 0.032), low albumin (P < 0.001) and low body mass index (P = 0.001).

CONCLUSION

Mortality after Hartmann's procedure for perforated diverticulitis has not decreased during the last 18 years. Morbidity has actually increased over time although this is related to increased disease severity and comorbidity. Future efforts should focus on the identification of patient subgroups benefiting from earlier elective surgery and alternative surgical approaches when perforated diverticulitis does occur.

Evolutionary programming-based univector field navigation method for past mobile robots

Most of navigation techniques with obstacle avoidance do not consider the robot orientation at the target position. These techniques deal with the robot position only and are independent of its orientation and velocity. To solve these problems this paper proposes a novel univector field method for fast mobile robot navigation which introduces a normalized two dimensional vector field. The method provides fast moving robots with the desired posture at the target position and obstacle avoidance. To obtain the sub-optimal vector field, a function approximator is used and trained by evolutionary programming. Two kinds of vector fields are trained, one for the final posture acquisition and the other for obstacle avoidance. Computer simulations and real experiments are carried out for a fast moving mobile robot to demonstrate the effectiveness of the proposed scheme.

Radioimmunotherapy: potential as a therapeutic strategy in non-Hodgkin's lymphoma

Lymphomas are the fifth most common malignancy in the United States and are increasing in incidence. Despite being among the most responsive malignancies to radiation and chemotherapy, the majority of patients relapse or have progressive disease. Monoclonal antibodies (MAbs) directed at cell-specific surface antigens have been useful in the diagnosis of lymphomas and, more recently, the therapeutic mouse-human chimeric MAb rituximab has demonstrated effectiveness in B cell lymphomas. Conjugating MAbs to radionuclides is a strategy for improving the efficacy of MAb lymphoma therapy by delivering radiation in close proximity to the tumour (radioimmunotherapy or RIT). In addition, the low dose rate of the delivered radiation may exert a greater antitumour activity than an equivalent dose of conventional external beam radiation. The antigenic targets for MAb therapy have included CD20, CD22, HLA-DR, and B cell idiotype. Radionuclides that have been used include iodine-131, yttrium-90, and copper-67; there are relative merits and disadvantages to each source of radiation. Clinical studies to date have focused on relapsed and refractory patients with both indolent and aggressive lymphomas, although more recent studies have included previously untreated patients with indolent lymphoma. Radioimmunoconjugate has been delivered as either single or multiple doses. Response rates have varied widely, dependent on the patient population and the response criteria. Of note, complete responses can be achieved in this typically refractory patient group. Toxicities have generally consisted of mild infusion-related nausea, fever, chills, and asthenia. Neutropenia and thrombocytopenia are the dose-limiting toxicities and have prompted the incorporation of autologous stem cell support as a means of achieving dose escalation. To date, RIT has been delivered to highly selected patients in relatively few centres with requisite equipment and specialised personnel. In addition to these requirements, cost is likely to be a barrier to widespread use. The combination of RIT with chemotherapy at conventional or high dose, or with biological agents is a fertile area for investigation. The potential of RIT in the treatment for lymphomas will be defined only by well designed comparative prospective clinical studies.

DC-SIGN, a dendritic cell-specific HIV-1-binding protein that enhances trans-infection of T cells

Dendritic cells (DC) capture microorganisms that enter peripheral mucosal tissues and then migrate to secondary lymphoid organs, where they present these in antigenic form to resting T cells and thus initiate adaptive immune responses. Here, we describe the properties of a DC-specific C-type lectin, DC-SIGN, that is highly expressed on DC present in mucosal tissues and binds to the HIV-1 envelope glycoprotein gp120. DC-SIGN does not function as a receptor for viral entry into DC but instead promotes efficient infection in trans of cells that express CD4 and chemokine receptors. We propose that DC-SIGN efficiently captures HIV-1 in the periphery and facilitates its transport to secondary lymphoid organs rich in T cells, to enhance infection in trans of these target cells.

Use of coreceptors other than CCR5 by non-syncytium-inducing adult and pediatric isolates of human immunodeficiency virus type 1 is rare in vitro

We have tested a panel of pediatric and adult human immunodeficiency virus type 1 (HIV-1) primary isolates for the ability to employ the following proteins as coreceptors during viral entry: CCR1, CCR2b, CCR3, CCR4, CCR5, CCR8, CXCR4, Bonzo, BOB, GPR1, V28, US28, and APJ. Most non-syncytium-inducing isolates could utilize only CCR5. All syncytium-inducing viruses used CXCR4, some also employed V28, and one (DH123) used CCR8 and APJ as well. A longitudinal series of HIV-1 subtype B isolates from an infected infant and its mother utilized Bonzo efficiently, as well as CCR5. The maternal isolates, which were syncytium inducing, also used CXCR4, CCR8, V28, and APJ.

Evidence for a glutathionyl-enzyme intermediate in the amidase activity of the bifunctional glutathionylspermidine synthetase/amidase from Escherichia coli

Glutathionylspermidine (Gsp) is a metabolite common to Escherichia coli and protozoal parasites of the Trypanosoma family. Though its role in E. coli is unknown, Gsp is known to be an intermediate in the biosynthesis of N1,N8-bis(glutathionyl)spermidine (trypanothione), a metabolite unique to trypanosomatids that may allow the parasites to overcome oxidative stresses induced by host defense mechanisms. The bifunctional Gsp-synthetase/amidase from E. coli catalyzes both amide bond formation and breakdown between the N1-amine of spermidine [N-(3-aminopropyl)-1,4-diaminobutane] and the glycine carboxylate of glutathione (gamma-Glu-Cys-Gly), with net hydrolysis of ATP [Bollinger et al. (1995) J. Biol. Chem. 270 (23), 14031-14041]. Synthetase and amidase activities reside in separate domains of the protein, and liberation of the amidase domain from the synthetase domain activates the amidase activity as much as 70-fold in kcat/K(m) for a chromogenic substrate gamma-Glu-Ala-Gly-pNA [Kwon et al., (1997) J. Biol. Chem. 272 (4), 2429-2436]. When substrates for the Gsp-synthetase activity are present (GSH, ATP-Mg2+), Gsp-amidase is highly activated (15-fold). We provide kinetic and mutagenesis evidence suggesting that the amidase operates by a nucleophilic attack mechanism involving cysteine as the catalytic nucleophile. Stopped-flow studies on the 25 kDa Gsp-amidase fragment and the 70 kDa full-length Gsp-synthetase/amidase with gamma-Glu-Ala-Gly-ONp demonstrate burst kinetics characteristic of a covalent acyl-enzyme intermediate. Studies using various group-specific protease inhibitors, such as iodoacetamide, suggest an active-site cysteine or histidine as being relevant to amidase activity, and site-directed mutagenesis indicates that Cys-59 is essential for amidase activity.

Design, synthesis, and biochemical evaluation of phosphonate and phosphonamidate analogs of glutathionylspermidine as inhibitors of glutathionylspermidine synthetase/amidase from Escherichia coli

Three phosphapeptides designed to mimic two distinct tetrahedral intermediates formed during either the synthesis or hydrolysis of glutathionylspermidine (Gsp) were synthesized and evaluated as inhibitors of the bifunctional enzyme Gsp synthetase/amidase. While the polyamine-containing phosphapeptides were determined to be potent and selective inhibitors, they selectively inhibit the synthetase activity over the amidase domain. A phosphonate-containing tetrahedral mimic is a reversible mixed-type inhibitor of Gsp synthetase with an inhibition constant of 6 microM for the inhibitor binding to the free enzyme (Ki) and 14 microM for the inhibitor binding to the enzyme-substrate complex (Ki'). The corresponding phosphonamidate is a slow-binding inhibitor with a Ki of 24 microM and a Ki* (isomerization inhibition constant) of 0.88 microM. A non-polyamine-containing phosphonamidate exhibits no significant inhibition of the synthetase or amidase activity.

Aldehyde and phosphinate analogs of glutathione and glutathionylspermidine: potent, selective binding inhibitors of the E. coli bifunctional glutathionylspermidine synthetase/amidase

INTRODUCTION

The tripeptide glutathione is converted to glutathionylspermidine (Gsp) in Escherichia coli and in trypanosomatid parasites by an ATP-cleaving Gsp synthetase activity. In parasites, an additional glutathionylation forms bis-(glutathionyl)-spermidine, trypanothione, believed to be the major surveillance thiol involved in oxidant defense mechanisms in trypanosomatid parasites. In E. coli, the Gsp synthetase is part of a bifunctional enzyme opposed by the hydrolytic Gsp amidase.

RESULTS

Gsp amidase and Gsp synthetase activities of the bifunctional E. coli enzyme can be separately targeted by potent, selective slow-binding inhibitors that induce time-dependent inhibition. The inhibitor gamma-Glu-Ala-Gly.CHO most probably captures Cys59 and accumulates as the tetrahedral adduct in the amidase active site. Inhibitory Gsp phosphinate analogs are phosphorylated by ATP to yield phosphinophosphate analogs in the synthetase active site. Binding of phosphinophosphate in the Gsp synthetase active site potentiates the inhibition affinity for the aldehyde at the Gsp amidase active site by two orders of magnitude.

CONCLUSIONS

Time-dependent inhibition of the Gsp amidase activity by the aldehyde substrate analog supports previous work that suggests glutathionyl acyl-enzyme intermediate formation in the Gsp amidase reaction mechanism. Use of potent selective inhibitors against Gsp amidase (aldehyde) and Gsp synthetase (phosphinate) activities provides further evidence of interdomain communication in the bifunctional enzyme from E. coli.

Dissection of glutathionylspermidine synthetase/amidase from Escherichia coli into autonomously folding and functional synthetase and amidase domains

The bifunctional glutathionylspermidine synthetase/amidase from Escherichia coli catalyzes both the ATP-dependent formation of an amide bond between N1 of spermidine (N-(3-amino)propyl-1, 4-diaminobutane) and the glycine carboxylate of glutathione (gamma-Glu-Cys-Gly) and the opposing hydrolysis of this amide bond (Bollinger, J. M., Jr., Kwon, D. S., Huisman, G. W., Kolter, R., and Walsh, C. T. (1995) J. Biol. Chem. 270, 14031-14041). In our previous work describing its initial characterization, we proposed that the 619-amino acid (70 kDa) protein might possess separate amidase (N-terminal) and synthetase (C-terminal) domains. In the present study, we have confirmed this hypothesis by expression of independently folding and functional amidase and synthetase modules. A fragment containing the C-terminal 431 amino acids (50 kDa) has synthetase activity only, with steady-state kinetic parameters similar to the full-length protein. A fragment containing the N-terminal 225 amino acids (25 kDa) has amidase activity only and is significantly activated relative to the full-length protein for hydrolysis of glutathionylspermidine analogs. This observation suggests that the amidase activity in the full-length protein is negatively autoregulated. The amidase active site catalyzes hydrolysis of amide and ester derivatives of glutathione (e.g. glutathione ethyl ester and glutathione amide) but lacks activity toward acetylspermidine (N1 and N8) and acetylspermine (N1), indicating that glutathione provides the primary recognition determinants for glutathionylspermidine amide bond cleavage. No metal ion is required for the amidase activity. A tetrahedral phosphonate analogue of glutathionylspermidine, designed as a mimic of the proposed tetrahedral intermediate for either reaction, inhibits the synthetase activity (Ki approximately 10 microM) but does not inhibit the amidase activity.

Glutathionylspermidine metabolism in Escherichia coli. Purification, cloning, overproduction, and characterization of a bifunctional glutathionylspermidine synthetase/amidase

Glutathionylspermidine (GSP) synthetases of Trypanosomatidae and Escherichia coli couple hydrolysis of ATP (to ADP and Pi) with formation of an amide bond between spermidine (N-(3-aminopropyl)-1,4-diaminobutane) and the glycine carboxylate of glutathione (gamma-Glu-Cys-Gly). In the pathogenic trypanosomatids, this reaction is the penultimate step in the biosynthesis of the antioxidant metabolite, trypanothione (N1,N8-bis-(glutathionyl)spermidine), and is a target for drug design. In this study, GSP synthetase was purified to near homogeneity from E. coli B, the gene encoding it was isolated and sequenced, the enzyme was overexpressed and purified in quantity, and the recombinant enzyme was characterized. The 70-kDa protein was found to have an unexpected second catalytic activity, glutathionylspermidine amide bond hydrolysis. Thus, the bifunctional GSP synthetase/amidase catalyzes opposing amide bond-forming and -cleaving reactions, with net hydrolysis of ATP. The synthetase activity is selectively abrogated by proteolytic cleavage 81 residues from the C terminus, suggesting that the two activities reside in distinct domains (N-terminal amidase and C-terminal synthetase). Proteolysis at this site is facile in the absence of substrates, but is inhibited in the presence of ATP, glutathione, and Mg2+. A series of analogs was used to probe the spermidine-binding site of the synthetase activity. The activity of diaminopropane as a substrate, inactivity of the C4-C8 diaminoalkanes, and greater loss of specificity for analogs modified in the 3-aminopropyl moiety than for those modified in the 4-aminobutyl moiety indicate that the enzyme recognizes predominantly the diaminopropane portion of spermidine and corroborate N-1 (the aminopropyl N) as the site of glutathione linkage (Tabor, H. and Tabor, C. W. (1975) J. Biol. Chem. 250, 2648-2654). Trends in Km and kcat for a set of difluorosubstituted spermidine derivatives suggest that the enzyme may bind the minor, deprotonated form of the amine nucleophile.

[Changes in blastogenic responses and antibody titers of mice infected with Toxoplasma gondii]

This study was performed to observe the cell-mediated and humoral immune responses in mice which were infected with Beverley, Fukaya and ME49 strain of Toxoplasma gondii, respectively. The blastogenic responses of splenocytes using [3H]-thymidine and serum antibody titers were measured weekly up to 10 weeks after infection. The blastogenic responses of splenocytes treated with concanavalin A and Toxoplasma lysate were significantly declined in the 3 strain groups as compared with the non-infected group (p less than 0.05), however lipopolysaccharide-treated blastogenic responses were not significantly different between infected and non-infected groups. The serum IgG antibody titers in the three infected groups increased from 2 weeks after infection, and the serum IgM antibody titers increased until 4 weeks after infection. No significant differences were revealed in blastogenic responses and serum antibody titers among the 3 groups. The present study suggested that cell-mediated immune responses were involved in T. gondii infected mice and blastogenic responses of T lymphocytes were inhibited in acute T. gondii infection.