Identifying and Predicting Subgroups of Veterans With Mild Traumatic Brain Injury Based on Distinct Configurations of Postconcussive Symptom Endorsement: A Latent Class Analysis.

OBJECTIVE: To identify distinct subgroups of veterans with mild traumatic brain injury (mTBI) based on configurations of postconcussive symptom (PCS) endorsement, and to examine predictors of subgroup membership. SETTING: Outpatient Veterans Health Administration (VHA). PARTICIPANTS: Veterans with clinician-confirmed mTBI who completed the Neurobehavioral Symptom Inventory (NSI), determined using the Comprehensive Traumatic Brain Injury Evaluation database. Individuals who tended to overreport symptoms were excluded via an embedded symptom validity scale. DESIGN: Retrospective cohort study leveraging national VHA clinical data from 2012 to 2020. Latent class analysis (LCA) with a split-sample cross-validation procedure was used to identify subgroups of veterans. Multinomial logistic regression was used to examine predictors of subgroup membership. MAIN MEASURES: Latent classes identified using NSI items. RESULTS: The study included 72 252 eligible veterans, who were primarily White (73%) and male (94%). The LCA supported 7 distinct subgroups of veterans with mTBI, characterized by diverging patterns of risk for specific PCS across vestibular (eg, dizziness), somatosensory (eg, headache), cognitive (eg, forgetfulness), and mood domains (eg, anxiety). The most prevalent subgroup was Global (20.7%), followed by Cognitive-Mood (16.3%), Headache-Cognitive-Mood (H-C-M; 16.3%), Headache-Mood (14.2%), Anxiety (13.8%), Headache-Sleep (10.3%), and Minimal (8.5%). The Global class was used as the reference class for multinomial logistic regression because it was distinguished from others based on elevated risk for PCS across all domains. Female (vs male), Black (vs White), and Hispanic veterans (vs non-Hispanic) were less likely to be members of most subgroups characterized by lesser PCS endorsement relative to the Global class (excluding Headache-Mood). CONCLUSION: The 7 distinct groups identified in this study distill heterogenous patterns of PCS endorsement into clinically actionable phenotypes that can be used to tailor clinical management of veterans with mTBI. Findings reveal empirical support for potential racial, ethnic, and sex-based disparities in PCS among veterans, informing efforts aimed at promoting equitable recovery from mTBI in this population.

Unmet Need for Outpatient Occupational Therapy Services Among Veterans With Mild Traumatic Brain Injury in the Veterans Health Administration: The Role of Facility Characteristics.

OBJECTIVE: To investigate whether participation restrictions, an indicator of need for occupational therapy (OT), was associated with outpatient OT utilization in the Veterans Health Administration (VHA) among Veterans with mild traumatic brain injury (mTBI), and whether this relation differs by facility characteristics. DESIGN: In a secondary analysis of national VHA data, we used modified Poisson regression to model OT utilization (yes/no) as a function of participation restrictions (Mayo-Portland Adaptability Inventory Participation Index [M2PI]), facility characteristics, and covariates. Facility characteristics included complexity, geographic region, and self-reported access to specialty care. Covariates included prior OT utilization, sociodemographic factors, injury characteristics, and spatial access (eg, drive time). Interactions estimated whether the relation between participation restrictions and OT utilization differed across facility characteristics. SETTING: Outpatient setting in the VHA. PARTICIPANTS: 8684 Veterans with a clinician-confirmed mTBI who received outpatient VHA care between 2012 and 2020 (N=8684). INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): OT utilization was measured within a year of M2PI administration using VHA administrative data. RESULTS: Many Veterans who did not receive OT reported participation limitations, indicating unmet need for OT (eg, 67% with leisure restrictions). Participation restrictions were associated with increased likelihood of receiving OT (risk ratio [RR]=1.01; 95% confidence interval [CI]=1.006-1.019), suggesting a tendency for Veterans' OT-related needs to be satisfied. However, interactions indicated that this was not the case among Veterans receiving care in lower complexity facilities, and those in the South. Veterans with longer drive times were less likely to receive OT (RR=0.82; 95% CI=0.744-0.904). CONCLUSIONS: Participation restrictions were associated with OT utilization, yet many Veterans with mTBI who may have benefited did not receive such care. Specific barriers to accessing OT (eg, OT practitioner supply) should be investigated. Novel care models can ensure access to OT services among Veterans seeking care at less-resourced and/or geographically distant VHA facilities.

Potential Effects of Regulating Intestinal Flora on Immunotherapy for Liver Cancer.

The intestinal flora plays an important role in the occurrence and development of liver cancer, affecting the efficacy and side effects of conventional antitumor therapy. Recently, immunotherapy for liver cancer has been a palliative treatment for patients with advanced liver cancer lacking surgical indications. Representative drugs include immune checkpoint inhibitors, regulators, tumor vaccines, and cellular immunotherapies. The effects of immunotherapy on liver cancer vary because of the heterogeneity of the tumors. Intestinal flora can affect the efficacy and side effects of immunotherapy for liver cancer by regulating host immunity. Therefore, applying probiotics, prebiotics, antibiotics, and fecal transplantation to interfere with the intestinal flora is expected to become an important means of assisting immunotherapy for liver cancer. This article reviews publications that discuss the relationship between intestinal flora and immunotherapy for liver cancer and further clarifies the potential relationship between intestinal flora and immunotherapy for liver cancer.

Comprehensive simultaneous kinetic study of sulfitolysis and thiosulfatolysis of tetrathionate ion: unravelling the unique pH dependence of thiosulfatolysis.

The kinetics of the reactions of tetrathionate with S(IV) species and with thiosulfate in slightly acidic and neutral media were studied concurrently at 25.0 ± 0.1 °C by simultaneous high-performance liquid chromatography monitoring of the concentrations of polythionates (including trithionate, tetrathionate, and pentathionate), thiosulfate, and sulfite. The tetrathionate-sulfite and tetrathionate-thiosulfate reactions were found to be first-order with respect to both reactants. The tetrathionate-sulfite reaction was found to be pH-dependent under the conditions studied. In contrast, the tetrathionate-thiosulfate reaction was experimentally demonstrated to be pH-independent at neutral medium, where the pKa2 value of sulfurous acid plays a key role, whereas under slightly acidic conditions, between pH 4 and 5 the consumption of tetrathionate during the course of reaction was found to become pH-dependent. We show that the pH dependencies in both systems can be readily explained by the reactivity difference between sulfite and bisulfite toward the ß-sulfur of the tetrathionate. A simple two-step kinetic model incorporating the protonation equilibrium of sulfite is proposed on the basis of the simultaneous evaluation of the kinetic curves of the two systems, which allowed us to determine reliable rate coefficients for both the forward and backward reactions. Furthermore, the powerful ability of simultaneously evaluating the two chemical systems to yield reliable rate coefficients of the kinetic model is demonstrated.

Effects of Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets on the Structure and Function of the Intestinal Flora in Rabbits Undergoing Hepatic Artery Infusion Chemotherapy.

Few studies have explored the biological mechanism by which probiotics alleviate adverse reactions to chemotherapy drugs after local hepatic chemotherapy perfusion by regulating the intestinal flora. This study investigates the effects of Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets on the intestinal microbial structure and intestinal barrier function, as well as the potential mechanism in rabbits after local hepatic chemotherapy infusion. Eighteen New Zealand White rabbits were randomly divided into a control group, a hepatic local chemotherapy perfusion group, and a hepatic local chemotherapy perfusion + Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets group to assess the effects of Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets on the adverse reactions. The administration of Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets alleviated the intestinal flora disorder caused by local hepatic perfusion chemotherapy, promoted the growth of beneficial bacteria, and inhibited the growth of harmful bacteria. The Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets also reduced the levels of serum pro-inflammatory cytokines and liver injury factors induced by local hepatic perfusion chemotherapy. Our findings indicate that Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets can ameliorate the toxicity and side effects of chemotherapy by regulating intestinal flora, blocking pro-inflammatory cytokines, reducing liver injury factors, and repairing the intestinal barrier. Probiotics may be used as a potential alternative therapeutic strategy to prevent the adverse reactions caused by chemotherapy with local hepatic perfusion.

Effect of Transarterial Chemotherapy on the Structure and Function of Gut Microbiota in New Zealand White Rabbits.

The gut microbiota (GM) are closely related to hepatocellular carcinoma (HCC) occurrence and development. Furthermore, patients with HCC who have received transcatheter arterial chemoembolization (TACE) treatment often experience adverse gastrointestinal reactions, which may be related to changes in the GM caused by the chemotherapeutic drugs used in TACE. Therefore, we conducted animal experiments to investigate these changes. We analyzed changes in the GM of New Zealand white rabbits treated with hepatic arterial chemotherapy by measuring the levels of serological and colonic tissue markers. Simultaneously, we evaluated the correlation between the GM and these markers to explore the mechanism by which chemotherapy affects the GM. Following transarterial chemotherapy with epirubicin, the Firmicutes abundance decreased, whereas that of Proteobacteria increased. The relative abundance of beneficial bacteria, such as Muribaculaceae, Enterococcus, Ruminococcus, and Clostridia, decreased in the experimental group compared with those in the control group. However, the relative abundance of harmful bacteria, such as Bacteroides and Escherichia (Shigella), was higher in the experimental group than in the control group. Following chemotherapy, the GM of rabbits showed a dynamic change over time, first aggravating and then subsiding. The changes were most notable on the fourth day after surgery and recovered slightly on the seventh day. The changes in the host's GM before and after arterial chemotherapy are evident. Hepatic arterial chemotherapy induces dysbiosis of the intestinal microbiota, disrupts intestinal barrier function, damages the integrity of the intestinal mucosa, increases intestinal permeability, facilitates excessive passage of harmful substances through the gut-liver axis communication between the liver and intestine, and triggers activation of inflammatory pathways such as LPS-TLR-4-pSTAT3, ultimately leading to an inflammatory response. This study provides a theoretical basis for combining TACE with targeted GM intervention to treat HCC and reduce adverse gastrointestinal reactions.

Serum uric acid, kidney volume and progression in autosomal-dominant polycystic kidney disease.

BACKGROUND: Hyperuricemia has been implicated in the development and progression of chronic kidney disease, both in animal experiments and in clinical studies. As a potentially modifiable risk factor, we examined whether serum uric acid levels correlate with early hypertension, kidney volume and progression to end-stage renal disease (ESRD) in autosomal-dominant polycystic kidney disease (ADPKD). METHODS: Retrospective analysis of a prospective observational study of the natural history of ADPKD, conducted at the University of Colorado between 1985 and 2005. Included are 680 ADPKD adults who provided data on blood pressure, renal volume, renal function, uric acid, age at the onset of ESRD or last known age without ESRD. Serum uric acid levels were examined as a continuous variable and as gender-specific quartiles. The main outcome of interest was age at the onset of ESRD; secondary outcomes were hypertension onset before age 30 years and total kidney volume (TKV) at the study visit. RESULTS: Subjects with early-onset hypertension had higher age-adjusted serum uric acid levels than those with no or late-onset hypertension despite similar creatinine clearance. After adjusting for age, gender and creatinine clearance, there was a 5.8% increase in TKV and 4.1% increase in TKV/body surface area for every 1 mg/dL increase in uric acid (P = 0.007). The multivariate-adjusted Cox regression demonstrated a greater hazard ratio for ESRD for subjects in the 4th and 3rd quartiles of uric acid compared with the 1st [4.8 (2.6-8.9; P < 0.001) and 2.9 (1.6-5.3; P < 0.001)]. CONCLUSIONS: Higher serum uric acid levels are associated with earlier onset of hypertension, larger kidney volume and increased hazard for ESRD in ADPKD independent of gender, body mass index and renal function at the study visit. Randomized interventional studies will be necessary to examine whether treating hyperuricemia has a protective role in ADPKD.

Intestinal Flora in Chemotherapy Resistance of Biliary Pancreatic Cancer.

Biliary pancreatic malignancy has an occultic onset, a high degree of malignancy, and a poor prognosis. Most clinical patients miss the opportunity for surgical resection of the tumor. Systemic chemotherapy is still one of the important methods for the treatment of biliary pancreatic malignancies. Many chemotherapy regimens are available, but their efficacy is not satisfactory, and the occurrence of chemotherapy resistance is a major reason leading to poor prognosis. With the advancement of studies on intestinal flora, it has been found that intestinal flora is correlated with and plays an important role in chemotherapy resistance. The application of probiotics and other ways to regulate intestinal flora can improve this problem. This paper aims to review and analyze the research progress of intestinal flora in the chemotherapy resistance of biliary pancreatic malignancies to provide new ideas for treatment.

Effects of Hypoxemia by Acute High-Altitude Exposure on Human Intestinal Flora and Metabolism.

This study examined the effects of hypoxemia caused by acute high-altitude hypoxia (AHAH) exposure on the human intestinal flora and its metabolites. The changes in the intestinal flora, metabolism, and erythropoietin content in the AHAH population under altitude hypoxia conditions were comprehensively analyzed using 16S rRNA sequencing, metabonomics, and erythropoietin content. The results showed that compared with those in the control group (C group), the flora and metabolites in the hypoxemia group (D group) were altered. We found alterations in the flora according to the metabolic marker tyrosine through random forest and ROC analyses. Fecal and serum metabonomics analyses revealed that microbial metabolites could be absorbed into the blood and participate in human metabolism. Finally, a significant correlation between tyrosine and erythropoietin (EPO) content was found, which shows that human intestinal flora and its metabolites can help to confront altitude stress by regulating EPO levels. Our findings provide new insights into the adaptive mechanism and prevention of AHAH.

Structure and Metabolic Characteristics of Intestinal Microbiota in Tibetan and Han Populations of Qinghai-Tibet Plateau and Associated Influencing Factors.

Residents of the Qinghai-Tibet Plateau might experience shifts in their gut microbiota composition as a result of the plateau environment. For example, high altitudes can increase the abundance of obligate anaerobic bacteria, decrease the number of aerobic bacteria and facultative anaerobic bacteria, increase probiotics, and decrease pathogenic bacteria. This study aimed to determine the structure and metabolic differences in intestinal microbial communities among the Tibetan and Han populations on the Qinghai-Xizang Plateau and shed light on the factors that influence the abundance of the microbial communities in the gut. The structural characteristics of intestinal microorganisms were detected from blood and fecal samples using 16S rRNA sequencing. Metabolic characteristics were detected using gas chromatography-time-of-flight mass spectrometry (GC-TOFMS). The influencing factors were analyzed using Spearman's correlation analysis. Bacteroides and Bifidobacterium were dominant in the intestinal tract of the Han population, while Bacteroides and Prevotella were dominant in that of the Tibetan population, with marked differences in Pseudomonas, Prevotella, and other genera. Ferulic acid and 4-methylcatechol were the main differential metabolites between the Tibetan and Han ethnic groups. This may be the reason for the different adaptability of Tibetan and Han nationalities to the plateau. Alanine aminotransferase and uric acid also have a high correlation with different bacteria and metabolites, which may play a role. These results reveal notable disparities in the compositions and metabolic characteristics of gut microbial communities in the Tibetan and Han people residing on the Qinghai-Tibet Plateau and may provide insights regarding the mechanism of plateau adaptability.

Microfluidics: Insights into Intestinal Microorganisms.

Microfluidics is a system involving the treatment or manipulation of microscale (10-9 to 10-18 L) fluids using microchannels (10 to 100 µm) contained on a microfluidic chip. Among the different methodologies used to study intestinal microorganisms, new methods based on microfluidic technology have been receiving increasing attention in recent years. The intestinal tracts of animals are populated by a vast array of microorganisms that have been established to play diverse functional roles beneficial to host physiology. This review is the first comprehensive coverage of the application of microfluidics technology in intestinal microbial research. In this review, we present a brief history of microfluidics technology and describe its applications in gut microbiome research, with a specific emphasis on the microfluidic technology-based intestine-on-a-chip, and also discuss the advantages and application prospects of microfluidic drug delivery systems in intestinal microbial research.

Prevalence of cardiovascular events in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: This study evaluates the prevalence of cardiovascular events in autosomal dominant polycystic kidney disease (ADPKD) patients. METHODS: We distributed surveys to 1,439 subjects from our ADPKD research database. In total, 426 subjects completed and returned surveys; 7 of these were from children and were excluded from the study. RESULTS: The patients who responded were female (63.2%), nonHispanic (88.1%) and white (93.6%). The mean age of the total group was 53.2 ± 13.7 years; 82.8% had a family history of ADPKD and 32.5% had reached end-stage renal disease (ESRD). With respect to cardiovascular risk factors, 86.6% were hypertensive with a mean age at diagnosis of 36.9 ± 12.9 years and hypertension was significantly more prevalent in males. In addition, 19.6% of the subjects were obese, 20.8% were smokers, 8.7% had diabetes, 45.7% had high cholesterol and 17.8% were sedentary. The most prevalent self-reported cardiovascular events were arrhythmias (25.9%), evidence of peripheral vascular disease (16.5%), heart valve problems (14.4%), cardiac enlargement (9.5%), stroke or cerebral bleeding (7.5%), myocardial infarction (6%) and brain aneurysm (5.0%). The most commonly used antihypertensive medications were renin-angiotensin inhibitors used by 75% of ADPKD patients. Older ADPKD patients and those at ESRD had a significantly higher incidence of cardiovascular events. CONCLUSION: These findings support the high prevalence of cardiovascular risk factors and events in ADPKD patients which contribute to a greater mortality risk. Due to the prevalence of cardiovascular risk factors in the ADPKD population, early diagnosis and clinical intervention are recommended.

The impact of type II diabetes mellitus in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: The epidemic of obesity and diabetes is increasing within the USA and worldwide. We have previously shown that body mass index has increased significantly in autosomal dominant polycystic kidney disease (ADPKD) subjects seen at our center in more recent years. However, the impact of Type II diabetes in ADPKD patients has not been well studied. METHODS: This retrospective cohort study compared clinical characteristics in 44 pre-renal transplant patients with ADPKD and diabetes and 88 age- and sex-matched non-diabetic patients with ADPKD who were seen at the University of Colorado between 1977 and 2008. The primary outcomes in this study were renal volume determined by renal ultrasonography, renal function assessed by estimated glomerular filtration rate and time to onset of end-stage renal disease or death by Kaplan-Meier analyses. RESULTS: Diabetic patients had significantly larger kidney volumes than those with ADPKD alone [geometric mean (95% confidence interval (CI)]: 2456 (1510-3992) versus 1358 (1186-1556) cm3, P=0.02. Among those whose age at hypertension diagnosis was known, the diabetic ADPKD patients had earlier median (95% CI) age at onset of hypertension compared to those with ADPKD alone: 32.5 (28-40) versus 38 (35-42) years, P=0.04. Diabetic ADPKD patients tended to have an earlier median age of death than those with ADPKD alone. CONCLUSIONS: Patients with ADPKD and type II diabetes have larger renal volumes, earlier age at diagnosis of hypertension and may die at a younger age compared to those patients with ADPKD alone. This study emphasizes the importance of diabetes risk management in ADPKD.

Review of the relationship and underlying mechanisms between the Qinghai-Tibet plateau and host intestinal flora.

The intestinal microbial community is the largest ecosystem in the human body, in which the intestinal flora plays a dominant role and has a wide range of biological functions. However, it is vulnerable to a variety of factors, and exposure to extreme environments at high altitudes, as seen on the Qinghai-Tibet plateau, may cause changes in the structure and function of the host intestinal flora. Conversely, the intestinal flora can help the host adapt to the plateau environment through a variety of ways. Herein, we review the relationship and underlying mechanism between the host intestinal flora and the plateau environment by discussing the characteristics of the plateau environment, its influence on the intestinal flora, and the important role of the intestinal flora in host adaptation to the plateau environment. This review aimed to provide a reference for maintaining the health of the plateau population.

Post-concussive symptoms mediate the relationship between sleep problems and participation restrictions among veterans with mild traumatic brain injury.

Background: Sleep problems are common among Veterans with mild traumatic brain injury (mTBI) and may contribute to participation restrictions. However, explanatory mechanisms underlying this relationship are poorly understood. Sleep problems are associated with post-concussive symptoms (e.g., headaches). In turn, post-concussive symptoms contribute to participation restrictions. We hypothesized that post-concussive symptom severity mediates the purported relationship between sleep problems and participation restrictions among Veterans with mTBI. Materials and Methods: This study was a retrospective analysis of clinical data among 8,733 Veterans with mTBI receiving Veterans Health Administration outpatient care. Sleep problems (yes/no) were identified using the sleep-related item from the Neurobehavioral Symptom Inventory (NSI). Post-concussive symptoms were measured using remaining NSI items. Participation restrictions were measured using the Mayo-Portland Adaptability Inventory Participation Index. We specified a latent variable path model to estimate relationships between: (1) sleep problems and three latent indicators of post-concussive symptoms [vestibular-sensory (e.g., headache)]; mood-behavioral [e.g., anxiety]; cognitive [e.g., forgetfulness]); and, (2) the three latent indicators of post-concussive symptoms and two latent indicators of participation restrictions (social and community participation [e.g., leisure activities]; productivity [e.g., financial management]). We examined the indirect effects of sleep problems upon participation restrictions, as mediated by post-concussive symptoms. Estimates were adjusted for sociodemographic factors (e.g., age), injury characteristics (e.g., blast), and co-morbid conditions (e.g., depression). Results: 87% of Veterans reported sleep problems. Sleep problems were associated with greater social and community participation restrictions, as mediated by mood-behavioral (ß = 0.41, p < 0.001) and cognitive symptoms (ß = 0.13, p < 0.001). There was no evidence that vestibular-sensory symptoms mediated this relationship (ß = -0.01, p = 0.48). Sleep problems were associated with greater productivity restrictions, as mediated by vestibular-sensory (ß = 0.16, p < 0.001) and cognitive symptoms (ß = 0.14, p < 0.001). There was no evidence that mood-behavioral symptoms mediated this relationship (ß = 0.02, p = 0.37). Discussion: Findings suggest that evidence-based sleep treatment should occupy a prominent role in the rehabilitation of Veterans with mTBI. Indirect effects of sleep problems differed when considering impact on social and community participation vs. productivity, informing individualized rehabilitative care for Veterans with mTBI.

Teacher Suggestion Feedback Facilitates Creativity of Students in STEAM Education.

This study examined the influence of the formative feedback types of teachers on creativity in Science, Technology, Engineering, Art, Mathematics (STEAM) education. Participants were 90 undergraduate students who were randomly assigned to the teacher opinions feedback group, the teacher suggestion feedback group, or the non-feedback group, and took part in three courses of STEAM education of 3D-printing technology. Before and after each course, they were asked to fill out the Eugene Creativity Test. The results showed that compare with the teacher opinions feedback group and the non-feedback group, the participants in the teacher suggestion feedback group showed a higher score on the creativity scale. This suggests that the teacher suggestion feedback can be useful for improving the creativity in STEAM education.

Linking Emotional Intelligence to Mental Health in Chinese High School Teachers: The Mediating Role of Perceived Organizational Justice.

Compare with other professions, teachers are reported to have a higher risk of poor mental health. This study examined the relationships between emotional intelligence, perceived organizational justice, and mental health among Chinese high school teachers. Three hundred and eighty-one high school teachers, with their age range between 21 and 50 years, were administered the Emotional Intelligence Scale, Perceived Organizational Justice Scale, and Mental Health Scale. The result found that emotional intelligence and perceived organizational justice directly influence the mental health of high school teachers. In addition, perceived organizational justice mediated the association between emotional intelligence and mental health. Moreover, the present study analyzes the different role of subtypes of perceived organizational justice on the relationships between emotional intelligence and mental health, and the results showed that the mediating effects of perceived distributive justice and interactive justice on emotional intelligence and mental health are not significant, only the perceived procedural justice mediated the relationships between emotional intelligence and teachers' mental health. The results are discussed in a conceptual context.

Role of the adenosine 3',5'-cyclic monophosphate (cAMP) in enhancing the efficacy of siRNA-mediated gene silencing in neuroblastoma cells.

Gene-silencing activity mediated by siRNA has been demonstrated in mammalian cells; however, the mechanism of its regulation is not well understood. Since downregulation of a number of genes occurs during adenosine 3',5'-cyclic monophosphate (cAMP)-induced differentiation of neuroblastoma (NB) cells, it is possible that cAMP may play a role in regulating siRNA activity during differentiation. To study this, we utilized an NB cell line (NBP2-PN25) that expresses a short-lived green fluorescent protein (d2EGFP) under the CMV promoter. These cells were transfected with a retroviral plasmid that expresses U6 promoter-driven expression of siRNA targeted to d2EGFP and then were treated with cAMP-elevating agents (200 microg/ml RO20-1724, an inhibitor of cyclic nucleotide phosphodiesterase, and 1 microg/ml prostaglandin A1, a stimulator of adenylate cyclase) for 2 or 24 h. The siRNA activity was measured by determining the level of intensity of d2EGFP protein by flow cytometry, and the level of d2EGFP mRNA by real-time PCR. The results showed that cAMP-elevating agents enhanced U6-driven siRNA activity directed towards d2EGFP in NB cells 24 h after treatment. One of the mechanisms of action of cAMP is mediated via phosphatidylinositol 3-kinase (PI3K) inhibition; therefore, we have investigated the effect of a PI3K inhibitor on siRNA activity. This study showed that inhibition of PI3K also enhanced U6-driven siRNA activity towards d2EGFP. cAMP-stimulating agents increased U6 transcript levels, perhaps suggesting that increased siRNA activity may in part be due to an increase in transcriptional activity. When NB cells were transfected with a synthetic siRNA directed to d2EGFP, both cAMP elevation and PI3K inhibition similarly enhanced siRNA activity. Sodium butyrate, which inhibits the growth of NB cells similar to the effect produced by cAMP, did not affect U6-driven siRNA activity towards d2EGFP. Protein kinase C (PKC) activation or inhibition also failed to affect siRNA activity in NB cells. This study also showed that cAMP elevation and PI3K inhibition increases U6-driven siRNA activity directed towards an endogenous gene, p53. Our data suggest a role for the cAMP pathway in affecting the efficacy of siRNA system during differentiation of NB cells.

Altered expression of genes regulating cell growth, proliferation, and apoptosis during adenosine 3',5'-cyclic monophosphate-induced differentiation of neuroblastoma cells in culture.

An elevation of the intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) induces terminal differentiation in neuroblastoma (NB) cells in culture; however, genetic alterations during differentiation have not been fully identified. To investigate this, we used Mouse Genome U74A microarray containing approximately 6000 functionally characterized genes to measure changes in gene expression in murine NB cells 30 min and 4, 24, and 72 h after treatment with cAMP-stimulating agents. Based on the time of increase in differentiated functions and their status (reversible versus irreversible) after treatment with cAMP-stimulating agents, the induction of differentiation in NB cells was divided into three distinct phases: initiation (about 4 h after treatment when no increase in differentiated functions is detectable), promotion (about 24 h after treatment when an increase in differentiated functions occurs, but they are reversible upon the removal of cAMP), and maintenance (about 72 h after treatment when differentiated functions are maximally expressed, but they are irreversible upon the removal of cAMP). Results showed that alterations in expression of genes regulating cell growth, proliferation, apoptosis, and necrosis occurred during cAMP-induced differentiation of NB cells. Genes that were upregulated during the initiation, promotion, or maintenance phase were called initiators, promoters, or maintainers of differentiation. Genes that were downregulated during the initiation, promotion, or maintenance phase were called suppressors of initiation, promotion, or maintenance phase. Genes regulating growth may act as initiators, promoters, maintainers, or suppressors of these phases. Genes regulating cell proliferation may primarily act as suppressors of promotion. Genes regulating cell cycle may behave as suppressors of initiation or promotion, whereas those regulating apoptosis and necrosis may act as initiators or suppressors of initiation or promotion. The fact that genetic signals for differentiation occurred 30 min after treatment with cAMP, whereas cell-cycle genes were downregulated at a later time, suggests that decision for NB cells to differentiate is made earlier and not at the cell-cycle stage, as commonly believed.

Changing referral characteristics of patients with autosomal dominant polycystic kidney disease.

OBJECTIVE: Autosomal dominant polycystic kidney disease is the most frequent life-threatening hereditary disease. The study objective was to assess whether the clinical characteristics of patients with autosomal dominant polycystic kidney disease who are referred to a major autosomal dominant polycystic kidney disease center have changed over time. METHODS: The clinical characteristics of patients with autosomal dominant polycystic kidney disease were compared between period A (1961-1990) and period B (1991-2011). The study took place at the Autosomal Dominant Polycystic Kidney Disease Center at the University of Colorado. A total of 837 patients referred with autosomal dominant polycystic kidney disease were included. Blood pressure control and renin-angiotensin-aldosterone system inhibition were instituted. Renal function, blood pressure, end-stage renal disease, and mortality were analyzed. RESULTS: The results in period B compared with period A demonstrated an earlier age of autosomal dominant polycystic kidney disease diagnosis (29 vs 35 years, P < .001), lower mean blood pressure (129/82 vs 142/91 mm Hg, P < .001), better estimated glomerular filtration rate (63.6 vs 44.6 mL/min, P < .001), and more therapy with angiotensin-converting enzyme inhibition (42.5% vs 13.6%, P < .001). Time from birth to end-stage renal disease (52.8 ± 0.6 vs 49.1 ± 0.6 years, P < .001) and birth to death (63.5 ± 1.5 years vs 57.2 ± 1.0 years, P < .001) was longer in period B compared with period A when adjusted for age at diagnosis, sex, and estimated glomerular filtration rate. The study was retrospective, which is a limitation. CONCLUSIONS: In period B, there was significantly better blood pressure control, more renin-angiotensin-aldosterone system inhibition, better preservation of renal function, and a longer period from birth to end-stage renal disease and death.