[Impact of changes in malignant tumor death spectrum on life expectancy in Tianjin residents from 1999-2019].

Objective: To analyze the effects of changes in the spectrum of deaths from malignant tumors on the life expectancies of residents of different ages, sexes, and regions (urban or rural) in Tianjin from 1999 to 2019. Methods: The Abridged Life Table method and the Arriaga's decomposition method were used to calculate the effects of changes in spectrum of deaths from malignant tumors on the life expectancies of Tianjin residents of different ages, sexes, and regions. Results: During 1999-2019, the life expectancies increased by 4.96 years and 5.69 years for males and females, respectively, in Tianjin. The decreases in the mortalities from malignant neoplasms contributed 0.12 year (3.30%) and 0.03 year (0.77%) for males and females, respectively, to the increase during 1999-2007, and 0.05 year (3.13%) and 0.12 year (6.08%) for males and females, respectively, during 2007-2019. The decreases in the mortality rates of malignant tumors contributed the most to the increase among residents in the 60-69 years group, and the decreases in mortality rates of lung, gastric, esophageal, and liver cancers had relatively larger contribution. Lung cancer had a negative effect on the life expectancies of men and rural residents, but a positive effect on those of women and urban residents. The significant increases in the mortality rates of lung, colorectal, and pancreatic cancers in the ≥85 years group had a large negative effect on the overall life expectancy. Breast and ovarian cancers contributed negatively to the life expectancy of female residents. Conclusion: The overall increase in the life expectancy in Tianjin from 1999 to 2019 was mainly attributed to the elderly and the decreases in the mortality rates of gastric, esophageal, and liver cancers, among other malignancies, while the increases in the mortality rates of lung, colorectal, gallbladder, pancreatic, and breast cancers were the most significant factors hindering the increase of the life expectancy in Tianjin.

[Acute macular neuroretinopathy: a case report].

A 16-year-old female patient experienced a rapid decline in bilateral visual acuity accompanied by central scotomas for 5 days following coronavirus disease 2019 infection. Ocular examination revealed findings consistent with acute macular neuroretinopathy. Structural en face imaging using optical coherence tomography demonstrated a wedge-shaped lesion with low reflectivity directed towards the fovea in both eyes. B-scan images revealed localized hyperreflective bands involving the outer nuclear layer and photoreceptor layer, with discontinuity of the ellipsoid zone. Based on clinical presentation and examination findings, a diagnosis of bilateral acute macular neuroretinopathy was established.

Changes in integrins αv and α5 with Nogo-A in the rat retina after optic nerve injury.

OBJECTIVE: The purpose of this study was to investigate whether integrin levels are associated with axon regeneration after central nervous system (CNS) injury. MATERIALS AND METHODS: By using immunohistochemistry, we performed a detailed investigation of the changes in and colocalization of integrins αv and α5, with Nogo-A in the retina after optic nerve injury. RESULTS: We confirmed that integrins αv and α5 were expressed in the rat retina and colocalized with Nogo-A. After optic nerve transection, we found that integrin α5 levels increased over 7 days, but integrin αv levels remained unchanged, while Nogo-A levels increased. CONCLUSIONS: It seems that the inhibition of axonal regeneration by the Amino-Nogo-integrin signaling pathway may not occur via changes in integrin levels.

30-day morbidity and mortality after transoral robotic surgery for human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma: A retrospective analysis of two prospective adjuvant de-escalation trials (MC1273 & MC1675).

OBJECTIVE: Dose de-escalation of adjuvant therapy (DART) in patients with HPV(+)OPSCC was investigated in two prospective Phase II and III clinical trials (MC1273 and MC1675). We report the 30-day morbidity and mortality associated with primary TORS resection in patients enrolled in these trials. MATERIALS AND METHODS: Patients with HPV(+)OPSCC, who underwent TORS resection between 2013 and 2020 were considered in this analysis. The severity of postoperative transoral bleeding was graded using both the Hinni Grade (HG) transoral surgery bleeding scale and the Common Terminology for Adverse Events (CTCAE) v5.0. Post-surgical complications within 30 days of surgery, as well as rates of tracheostomy, PEG and nasogastric tube placement. RESULTS: 219 patients were included. A total of 7 (3.2 %) patients had a tracheostomy placed at the time of surgery, and all were decannulated within 26 days (median: 5, range: 2-26). There were 33 (15.1 %) returns to the emergency department (ED) with 10 (4.6 %) patients requiring readmission. Using the HG scale, 10 (4.6 %) patients experienced ≥ Grade 3 bleeding with no Grade 5 or 6 bleeds. In contrast, using the CTCAE scale, 15 patients (6.8 %) experienced ≥ Grade 3 bleeding with no Grade 5 bleeds. There was one post-operative death in a patient withdrawn from the trial, and no deaths related to hemorrhage. CONCLUSION AND RELEVANCE: TORS for HPV(+)OPSCC in carefully selected patients at a high volume center was associated with low morbidity and mortality.

[Reinforced radiculoplasty for the treatment of symptomatic sacral Tarlov cysts: A clinical analysis of 71 cases].

OBJECTIVE: To investigate the safety and efficacy of reinforced radiculoplasty in the treatment of symptomatic sacral Tarlov cysts (TCs). METHODS: A retrospective analysis was performed on the clinical data and follow-up data of 71 patients with symptomatic sacral TCs who underwent reinforced radiculoplasty in the Neurosurgery Department of Peking University Third Hospital from June 2018 to March 2021. All the operations were performed under neuroelectrophysiological monitoring. Intraoperative cyst exploration, partial resection of the cyst wall, narrowing of the leak, nerve root sleeve radiculoplasty and artificial dural reinforcement were performed. The incidence of postoperative complications and new neurological dysfunction was analyzed. Visual analogue scale (VAS) was used to assess the changes of pain before and after surgery. The Japanese Orthopedics Association (JOA) low back pain score was used to evaluate the changes in nerve function before and after surgery. RESULTS: In the study, 71 patients had 101 TCs, 19 (18.8%) TCs originated from the left S1 nerve, 26 (25.7%) originated from the left S2 nerve, 3 (3.0%) originated from the left S3 nerve, 14 (13.9%) originated from the right S1 nerve, 33 (32.7%) originated from the right S2 nerve, 6 (5.9%) originated from the right S3 nerve, all the TCs underwent reinforced radiculoplasty. Deep infection (1 case), subcutaneous effusion (1 case), fat li-quefaction (1 case) and urinary tract infection (4 cases) were recorded postoperatively. The patients were followed up for 12-43 months (median, 26 months). Two cases had new urinary retention after operation, and the catheter was removed at the end of the first and second months respectively. One case had new fecal weakness, which improved after 3 months. Compared with preoperation, VAS decreased significantly at the last follow-up [median, 6 (4-9) vs. 1 (0-5), Z=-7.272, P < 0.001], JOA score increased significantly [median, 20 (16-25) vs. 27 (18-29), Z=-7.265, P < 0.001]. There were 18 cured cases (25.4%), 41 excellent cases (57.7%), 8 effective cases (11.3%), and 4 invalid cases (5.6%). The total efficiency was 94.4% (67/71). Two (1.98%) cysts recurred. CONCLUSION: For patients with symptomatic sacral TCs, reinforced radiculoplasty can significantly improve the pain and nerve function, which is safe and reliable.

[Shandong hilly rural natural population cohort study: method and baseline characteristics of survey subjects].

Objective: To understand the study method and the baseline characteristics of the survey subjects of Shandong hilly rural natural population cohort study, and provide reference for the research of the prevalence and risk factors of common chronic and non-communicable diseases. Methods: Baseline survey, including questionnaire survey, physical examination, biochemical index examination and blood and saliva collection, was conducted in local residents aged 20-79 years in Kongcun and Xiaozhi townships of Pingyin county, Shandong province, from 2017 to 2019. Shandong hilly rural natural population cohort was established and main baseline characteristics of the study subjects were statistically analyzed. Results: A total of 10 296 study subjects aged 54.45 years were included in the study, in whom 40.6% were males. Among the study subjects, 88.3% had education level of junior high school or below, 62.1% were famers, and 90.7% were married. Smokers accounted for 45.6% of men and 0.9% of women, and drinkers accounted for 65.8% of men and 3.0% of women, respectively. The self-reported rates of hypertension, diabetes, coronary heart disease, stroke and tumors were 19.8%, 3.2%, 2.8%, 2.7% and 1.2%, respectively. Conclusion: The Shandong hilly rural cohort natural population study provided important evidence for assessing the risk for common chronic and non-communicable diseases and disease prevention and control in hilly rural areas.

Effect of tirofiban in treating patients with progressive ischemic stroke.

OBJECTIVE: Our aim is to investigate the efficacy and safety of tirofiban in the treatment of patients experiencing progressive ischemic stroke (PIS). PATIENTS AND METHODS: A retrospective analysis was performed on the clinical data of 150 patients with ischemic stroke admitted to our hospital from May 2018 to December 2019. All the patients were divided into two groups according to different treatment methods. In Control group, conventional comprehensive treatment and antiplatelet therapy with aspirin + clopidogrel were conducted, while tirofiban was administered in Tirofiban group in addition to the treatments in Control group. Neurological deficits were scored by means of the National Institutes of Health Stroke Scale (NIHSS) at the time of progression and 30 d after treatment, and the modified Rankin Scale (mRS) and Activity of Daily Living (ADL) scale were employed to assess prognosis at 90 d after treatment. Thereafter, the platelet aggregation rate, platelet adhesion rate, plateletcrit (PCT), platelet distribution width (PDW), and platelet inhibition rate were measured before and after treatment. Finally, the patients were followed up, and the occurrence of hemorrhage events during treatment and within 90 d after discharge was recorded. RESULTS: After treatment, all the patients had significantly lower NIHSS and mRS scores and a dramatically higher Barthel index (BI) than those before treatment (p<0.001). At 90 d after treatment, Tirofiban group exhibited significantly higher BI (p<0.001) and lower mRS score than Control group (p=0.011). In addition, at 14 d after treatment, the clinical efficacy was assessed for all the patients. It was found that the overall response rate in Tirofiban group was substantially higher than that in Control group [82.7% (62/75) vs. 64.0% (48/75), p=0.009]. At 7 d after treatment, the PCT and adenosine diphosphate (ADP) platelet inhibition rate in Tirofiban group were markedly higher than those in Control group (p=0.006, p<0.001), and Tirofiban group had remarkably lower measured values of platelet aggregation rate, platelet adhesion rate and PDW than Control group (p=0.007, p=0.021, p<0.001). After treatment, the levels of serum IL-6 and hs-CRP declined notably in the two groups of patients, and the differences in their levels at 2 and 14 d after treatment between the two groups were statistically significant (p<0.05). During treatment and within 90 d after discharge, both groups of patients had no cerebral hemorrhage, gastrointestinal hemorrhage, and severe hemorrhage adverse events requiring blood transfusion, but they experienced subcutaneous ecchymosis, epistaxis, gingival hemorrhage, and hemorrhage around the infarct, which were improved after symptomatic treatment. Moreover, the occurrence rate of hemorrhage in Tirofiban group was higher than that in Control group, showing no statistically significant difference (p>0.05). CONCLUSIONS: Tirofiban combined with conventional basic treatment can greatly improve neurological deficits and disease outcomes, alleviate platelet adhesion, and reduce platelet activation without increasing the risk of hemorrhage in PIS patients.

Changes of brain-derived neurotrophic factors in rats with generalized anxiety disorder before and after treatment.

OBJECTIVE:   The aim of the current study was to investigate the association between brain-derived neurotrophic factor (BDNF) and generalized anxiety disorder (GAD). MATERIALS AND METHODS: A total of sixty male adult Wistar rats with similar body weight and age were randomly divided into 3 groups the blank control group (CON, n=20), the saline control group (SAL, n=20), and the combined medication group (Deanxit +fluoxetine, DF, n=20), then rats in group SAL and group DF were prepared for model of anxiety disorder for 14 days. The body weight, center-retention time (CRT) and square-crossover number per unit time (SCN) were compared during modeling to define the anxiety of rats on day 1, day 7 and day 14; the BDNF mRNA in brain were detected by RT-PCR and the protein of BDNF in brain were detected by immunohistochemistry before and after intervention. The body weight, CRT and SCN in group SAL and DF after modeling were decreased with time compared with CON (p<0.05). The rats were taken euthanasia after 14 days, the BDNF mRNA showed significant decrease in SAL group (0.58±0.07) compared with group CON (2.87±0.23), while in DF group (1.76±0.21), the BDNF mRNA were higher than SAL group but lower than CON (p<0.05); the BDNF positive cells in group CON was highest (90%), then was group DF (75%) and group SAL was the lowest (35%). RESULTS: The changes in the indexes of the rats among different groups before and after modeling showed that after modeling, the body weights of the rats in group SAL and group DF were lower than group CON, the CRT decreased, and the SCN increased. The differences were statistically significant (p < 0.05), indicating that the combined medication (Qilixin + fluoxetine) can improve anxiety symptoms (body weight, CRT, and SCN). CONCLUSIONS: Anti-anxiety drugs (Deanxit+fluoxetine) can improve anxiety symptoms of rats and increase the expressions of BDNF mRNA and protein in rat brain cells. Anxiolytic drugs (Deanxit+fluoxetine) may achieve the treatment of anxiety disorders through improving the 5-HT nervous system and the expressions of BDNF mRNA and protein. BDNF can be used as a biochemical indicator for the diagnosis and efficacy evaluation of GAD.

Magnitude and temporal trend of acne vulgaris burden in 204 countries and territories from 1990 to 2019: an analysis from the Global Burden of Disease Study 2019.

BACKGROUND: Acne vulgaris is widespread across the world. Mapping the latest magnitudes and temporal trends of acne vulgaris provides the essential foundation for targeted public policies at the national, regional and global levels. OBJECTIVES: In compliance with the framework of the Global Burden of Disease Study 2019, this study aimed to summarize the incidence, prevalence, DALYs and the corresponding secular trends of acne vulgaris by sex and age group in 204 countries from 1990 to 2019. METHODS: The average annual percentage change was calculated to depict the temporal trends in age-standardized rates (ASRs) of acne vulgaris burden by region, sex and age. RESULTS: Globally, it was estimated that there were 117·4 million [95% uncertainty interval (UI) 103·0-133.7] incident cases of acne vulgaris, 231·2 million (95% UI 208·2-255·5) prevalent cases and 5·0 (95% UI 3·0-7·9) million DALYs, with an increase of approximately 48% compared with 1990. Moreover, the overall ASRs of acne vulgaris increased by approximately 0·55% annually over the past three decades. We observed large disparities in ASRs of acne vulgaris with changing trends in sex, location and age. The ASR of acne vulgaris among women was around 1·3 times that of men, but the sex difference was narrowed because of the pronounced increase among men. The ASRs of acne vulgaris were higher in high-income regions, but the increasing trend was more pronounced in other regions. CONCLUSIONS: The burden rate of acne vulgaris continues to increase in almost all countries. Understanding the specific characteristics of acne vulgaris burden is essential to formulate more effective and targeted interventions for controlling acne burden.

Propofol ameliorates acute postoperative fatigue and promotes glucagon-regulated hepatic gluconeogenesis by activating CREB/PGC-1α and accelerating fatty acids beta-oxidation.

Postoperative fatigue (POF) is the most common and long-lasting complication after surgery, which brings heavy burden to individuals and society. Recently, hastening postoperative recovery receives increasing attention, but unfortunately, the mechanisms underlying POF remain unclear. Propofol is a wildly used general anesthetic in clinic, and inspired by the rapid antidepressant effects induced by ketamine at non-anesthetic dose, the present study was undertaken to investigate the anti-fatigue effects and underlying mechanisms of propofol at a non-anesthetic dose in 70% hepatectomy induced POF model in rats. We first showed here that single administration of propofol at 0.1 mg/kg ameliorated acute POF in hepatectomy induced POF rats. Based on metabonomics analysis, we hypothesized that propofol exerted anti-fatigue activity in POF rats by facilitating free fatty acid (FFA) oxidation and gluconeogenesis. We further confirmed that propofol restored the deficit in FFA oxidation and gluconeogenesis in POF rats, as evidenced by the elevated FFA utilization, acetyl coenzyme A content, pyruvic acid content, phosphoenolpyruvic acid content, hepatic glucose output and glycogen storage. Moreover, propofol stimulated glucagon secretion and up-regulated expression of cAMP-response element binding protein (CREB), phosphorylated CREB, peroxlsome prolifeator-activated receptor-γ coactivator-1α (PGC-1α), phosphoenolpyruvate carboxykinade1 and carnitine palmitoltransferase 1A. In summary, our study suggests for the first time that propofol ameliorates acute POF by promoting glucagon-regulated gluconeogenesis via CREB/PGC-1α signaling and accelerating FFA beta-oxidation.

A coliform-targeted metagenomic method facilitating human exposure estimates to Escherichia coli-borne antibiotic resistance genes.

Antimicrobial resistance and the spread of antibiotic resistance genes (ARGs) pose a threat to human health. Community-acquired infections resistant to treatment with first-line antibiotics are increasing, and there are few studies investigating environmental exposures and transmission. Our objective is to develop a novel targeted metagenomic method to quantify the abundance and diversity of ARGs in a faecal indicator bacterium, and to estimate human exposure to resistant bacteria in a natural environment. Sequence data from Escherichia coli metagenomes from 13 bathing waters in England were analysed using the ARGs Online Analysis Pipeline to estimate the abundance and diversity of resistance determinants borne by this indicator bacterium. These data were averaged over the 13 sites and used along with data on the levels of E. coli in English bathing waters in 2016 and estimates of the volume of water that water users typically ingest in an average session of their chosen activityto quantify the numbers of ARGs that water users ingest. Escherichia coli in coastal bathing waters were found to harbour on average 1.24 ARGs per cell. Approximately 2.5 million water sports sessions occurred in England in 2016 that resulted in water users ingesting at least 100 E. coli-borne ARGs.

Local infiltration analgesia versus femoral nerve block in total knee arthroplasty: a meta-analysis.

INTRODUCTION: Local infiltration analgesia (LIA) and femoral nerve block (FNB) are both used for the pain management after total knee arthroplasty (TKA). Controversy still remains regarding the optimal technique for pain relief in patients undergoing TKA. The purpose of this meta-analysis was to compare the analgesia achieved with LIA and the one from FNB following TKA. HYPOTHESIS: LIA achieves better pain control than FNB in patients with TKA. METHODS: Databases, including Pubmed, EMBASE, the Cochrane Library and Web of Science were comprehensively searched to identify studies comparing LIA with FNB for patients with TKA. Two reviewers independently selected trials, extracted data, and assessed the methodological qualities of included studies. Data were analyzed by RevMan 5.2. RESULTS: Nine RCTs involving 782 patients were included. LIA achieved more rapid pain relief (VAS) at 6h postoperatively [SMD6h=-0.92, 95% CI (-1.38, -0.47)] than FNB. There were no significant differences at 24h and 48h [SMD24h=-0.03, 95% CI (-0.46, 0.40); SMD48h=0.28, 95% CI (-0.35, 0.91)], VAS with activity at 24h and 48h [SMD6h=-0.54, 95% CI (-1.62, 0.54); SMD24h=-0.22, 95% CI (-1.41, 0.96); SMD48h=-0.08, 95% CI (-0.52, 0.69)], opioid consumption at 24h and 48h [SMD24h=-0.24, 95% CI (-0.82, 0.34); SMD48h=0.15, 95% CI (0.25, 0.54)] and length of hospital stay [MD=-0.52, 95% CI (-1.13, 0.09)]. DISCUSSION: LIA may be the better choice in the pain management of TKA for it could achieve fast pain relief and is easier to perform than FNB for patients with TKA. LEVEL OF EVIDENCE: Level II, meta-analysis and systematic review.

MiR-181 family: regulators of myeloid differentiation and acute myeloid leukemia as well as potential therapeutic targets.

MicroRNAs have been shown to play an important role in normal hematopoisis and leukemogenesis. Here, we report function and mechanisms of miR-181 family in myeloid differentiation and acute myeloid leukemia (AML). The aberrant overexpression of all the miR-181 family members (miR-181a/b/c/d) was detected in French-American-British M1, M2 and M3 subtypes of adult AML patients. By conducting gain- and loss-of-function experiments, we demonstrated that miR-181a inhibits granulocytic and macrophage-like differentiation of HL-60 cells and CD34+ hematopoietic stem/progenitor cells (HSPCs) by directly targeting and downregulating the expression of PRKCD (which then affected the PRKCD-P38-C/EBPα pathway), CTDSPL (which then affected the phosphorylation of retinoblastoma protein) and CAMKK1. The three genes were also demonstrated to be the targets of miR-181b, miR-181c and miR-181d, respectively. Significantly decreases in the expression levels of the target proteins were detected in AML patients. Inhibition of the expression of miR-181 family members owing to Lenti-miRZip-181a infection in bone marrow blasts of AML patients increased target protein expression levels and partially reversed myeloid differentiation blockage. In the mice implanted with AML CD34+ HSPCs, expression inhibition of the miR-181 family by Lenti-miRZip-181a injection improved myeloid differentiation, inhibited engraftment and infiltration of the leukemic CD34+ cells into the bone marrow and spleen, and released leukemic symptoms. In conclusion, our findings revealed new mechanism of miR-181 family in normal hematopoiesis and AML development, and suggested that expression inhibition of the miR-181 family could provide a new strategy for AML therapy.

The role, mechanism and potentially therapeutic application of microRNA-29 family in acute myeloid leukemia.

Abnormal proliferation, apoptosis repression and differentiation blockage of hematopoietic stem/progenitor cells have been characterized to be the main reasons leading to acute myeloid leukemia (AML). Previous studies showed that miR-29a and miR-29b could function as tumor suppressors in leukemogenesis. However, a comprehensive investigation of the function and mechanism of miR-29 family in AML development and their potentiality in AML therapy still need to be elucidated. Herein, we reported that the family members, miR-29a, -29b and -29c, were commonly downregulated in peripheral blood mononuclear cells and bone marrow (BM) CD34+ cells derived from AML patients as compared with the healthy donors. Overexpression of each miR-29 member in THP1 and NB4 cells markedly inhibited cell proliferation and promoted cell apoptosis. AKT2 and CCND2 mRNAs were demonstrated to be targets of the miR-29 members, and the role of miR-29 family was attributed to the decrease of Akt2 and CCND2, two key signaling molecules. Significantly increased Akt2, CCND2 and c-Myc levels in the AML cases were detected, which were correlated with the decreased miR-29 expression in AML blasts. Furthermore, a feed-back loop comprising of c-Myc, miR-29 family and Akt2 were found in myeloid leukemogenesis. Reintroduction of each miR-29 member partially corrected abnormal cell proliferation and apoptosis repression and myeloid differentiation arrest in AML BM blasts. An intravenous injection of miR-29a, -29b and -29c in the AML model mice relieved leukemic symptoms significantly. Taken together, our finding revealed a pivotal role of miR-29 family in AML development and rescue of miR-29 family expression in AML patients could provide a new therapeutic strategy.

Co-inherited ß-thalassemia trait and HbH disease: clinical characteristics and interference in diagnosis of thalassemia by high-performance liquid chromatography.

INTRODUCTION: To identify the clinical and hematological characteristics in a large group of patients with combined HbH disease and ß-thalassemia trait. METHODS: Hemoglobinopathy analysis and full genotyping identified a cohort of patients with HbH disease, ß-thalassemia trait, or combined HbH disease and ß-thalassemia trait. RESULTS: Co-inheritance of ß-thalassemia trait and HbH disease significantly decreased the mean corpuscular volume (MCV) in 27 patients when compared to 287 patients with HbH disease alone. The combined condition also alleviated anemia in nondeletional HbH disease but not in the deletional cases. Beta-thalassemia trait also significantly decreased the expression of HbH, Hb Constant Spring when present, and HbA(2) , with levels as low as 3.6% on high-performance liquid chromatography (HPLC). CONCLUSION: These cases, although relatively common in the South Chinese population, may be difficult do diagnose correctly when only examined on HPLC. Therefore, molecular analysis of the α and ß globin genes should be done in all cases with hemolytic anemia and low MCV without clear HbH disease or ß-thalassemia parameters.

Transport of Sr2+ and SrEDTA2- in partially-saturated and heterogeneous sediments.

Strontium-90 has migrated deep into the unsaturated subsurface beneath leaking storage tanks in the Waste Management Areas (WMA) at the U.S. Department of Energy's (DOE) Hanford Reservation. Faster than expected transport of contaminants in the vadose zone is typically attributed to either physical hydrologic processes such as development of preferential flow pathways, or to geochemical processes such as the formation of stable, anionic complexes with organic chelates, e.g., ethylenediaminetetraacetic acid (EDTA). The goal of this paper is to determine whether hydrological processes in the Hanford sediments can influence the geochemistry of the system and hence control transport of Sr(2+) and SrEDTA(2-). The study used batch isotherms, saturated packed column experiments, and an unsaturated transport experiment in an undisturbed core. Isotherms and repacked column experiments suggested that the SrEDTA(2-) complex was unstable in the presence of Hanford sediments, resulting in dissociation and transport of Sr(2+) as a divalent cation. A decrease in sorption with increasing solid:solution ratio for Sr(2+) and SrEDTA(2-) suggested mineral dissolution resulted in competition for sorption sites and the formation of stable aqueous complexes. This was confirmed by detection of MgEDTA(2-), MnEDTA(2-), PbEDTA(2-), and unidentified Sr and Ca complexes. Displacement of Sr(2+) through a partially-saturated undisturbed core resulted in less retardation and more irreversible sorption than was observed in the saturated repacked columns, and model results suggested a significant reservoir (49%) of immobile water was present during transport through the heterogeneous layered sediments. The undisturbed core was subsequently disassembled along distinct bedding planes and subjected to sequential extractions. Strontium was unequally distributed between carbonates (49%), ion exchange sites (37%), and the oxide (14%) fraction. An inverse relationship between mass wetness and Sr suggested that sandy sediments of low water content constituted the immobile flow regime. Our results suggested that the sequestration of Sr(2+) in partially-saturated, heterogeneous sediments was most likely due to the formation of immobile water in drier regions having low hydraulic conductivities.