Hydrochemical characterization, spatial distribution, and geochemical controls on arsenic and boron in waters from arid Arica and Parinacota, northern Chile.

The livelihood of inhabitants from rural agricultural valleys in the arid Arica and Parinacota Region, northernmost Chile, strongly depends on water from high altitude rainfall and runoff to lower elevation areas. However, elevated arsenic, boron, and other potentially harmful elements compromise water quality, especially in rural areas. Samples (n = 90) of surface, underground, cold, geothermal springs, and treated and raw tap water were studied to assess water quality and to determine the main geochemical controls on water composition, origin, and geochemical evolution along dominant flowpaths. Water from major river basins across the region (Lluta, San Jose, Codpa-Chaca, Camarones and Altiplanicas) were collected for hydrogeochemical analysis of a suite of major and trace elements, δD and δ18O. Our new dataset was supplemented by hydrochemical data (n > 1500 data points) from secondary sources. Results show that 72% of the collected samples had As >10 µg/L (WHO drinking water provisional guideline) and affected 44% of the studied waters used for drinking (n = 32). Based on Chilean irrigation guidelines, elevated salinity (EC > 0.75 mS/cm) affected 80% of sampled waters, which were also impacted by high B (89% > 0.75 mg/L), and As (31% > 50 µg/L). Water composition was strongly controlled by geothermal water and freshwater mixing in high altitude areas. Magnitude and fate of As and B concentration was determined by the geothermal input type. Highest As (~21 mg/L) was associated with circum-neutral Na-Cl waters in Camarones basin, while lower As (~5 mg/L) with acid SO4 waters in Lluta basin. Additionally, evaporative concentration and sediment-water interactions were shown to control the level of As in surface and groundwaters downstream. This works provides a comprehensive analysis and a conceptual model of geochemical controls on regional water compositions, contributing to better understanding the geochemical processes underpinning the water quality challenges in northern Chile.

Overexpression of ERG in cord blood progenitors promotes expansion and recapitulates molecular signatures of high ERG leukemias.

High expression of the ETS family transcription factor ERG is associated with poor clinical outcome in acute myeloid leukemia (AML) and acute T-cell lymphoblastic leukemia (T-ALL). In murine models, high ERG expression induces both T-ALL and AML. However, no study to date has defined the effect of high ERG expression on primary human hematopoietic cells. In the present study, human CD34+ cells were transduced with retroviral vectors to elevate ERG gene expression to levels detected in high ERG AML. RNA sequencing was performed on purified populations of transduced cells to define the effects of high ERG on gene expression in human CD34+ cells. Integration of the genome-wide expression data with other data sets revealed that high ERG drives an expression signature that shares features of normal hematopoietic stem cells, high ERG AMLs, early T-cell precursor-ALLs and leukemic stem cell signatures associated with poor clinical outcome. Functional assays linked this gene expression profile to enhanced progenitor cell expansion. These results support a model whereby a stem cell gene expression network driven by high ERG in human cells enhances the expansion of the progenitor pool, providing opportunity for the acquisition and propagation of mutations and the development of leukemia.

Endothelial cell dysfunction and cytoskeletal changes associated with repression of p16(INK4a) during immortalization.

The immortalization process is a fundamental step in the development of most (if not all) human cancers, including the aggressive endothelial cell (EC)-derived malignancy angiosarcoma. Inactivation of the tumor suppressor p16(INK4a) and the development of multiple chromosomal abnormalities are features of angiosarcoma that are recapitulated during telomerase-mediated immortalization of human ECs in vitro. The present study used a panel of telomerase-immortalized bone marrow EC (BMEC) lines to define the consequences of inactivation of p16(INK4a) on EC function and to identify molecular changes associated with repression of p16(INK4a). In a comparison of two immortalized BMEC mass cultures and six clones, the cell lines that repressed p16(INK4a) showed a higher rate of proliferation and an impaired ability to undergo morphogenic differentiation and form vessel-like structures in vitro. Proteomic comparison of a p16(INK4a)-negative and a p16(INK4a)-positive BMEC mass culture at early- and late-passage time points following transduction with telomerase reverse transcriptase (hTERT) revealed altered expression of cytoskeletal proteins, including vimentin and α-tropomyosin (αTm), in the immortal cells. Immunoblot analyses of a panel of 11 immortal clones showed that cells that lacked p16(INK4a) expression tended to accumulate more dramatic changes in these cytoskeletal proteins than cells that retained p16(INK4a) expression. This corresponded with aberrant cytoskeletal architectures among p16(INK4a)-negative clones, which featured thicker actin stress fibers and less fluid membrane ruffles than p16(INK4a)-positive cells. A direct link between p16(INK4a) repression and defective EC function was confirmed by analysis of normal cells transfected with small interfering RNA (siRNA) targeting p16(INK4a). siRNA-mediated repression of p16(INK4a) significantly impaired random motility and vessel formation in vitro. This report is the first to demonstrate that ECs that repress the expression of p16(INK4a) are prone to defects in motility, morphogenesis and cytoskeletal organization. These defects are likely to reflect alterations that occur during the development of EC-derived malignancies.

An inpatient cervical cancer screening program to reach underserved women.

Underserved women (e.g., African American, older women of all races) are less likely to be screened than other groups. The Johns Hopkins Hospital began the Cervical Cancer Screening Program (CCSP) to provide direct Papanicolaou (Pap) test screening to inpatient females. Over a 1-year period, 256 women received Pap tests as part of the CCSP. Of these, 56% (n = 144) were African American, 36% (n = 92) received medical assistance benefits, and only 47% (n = 120) had health insurance. The CCSP is an effective way to screen low-income and underserved females who otherwise may not be screened.

Bench stepping and running in women. Changes in fitness and injury status.

BACKGROUND: The purpose of this investigation was to evaluate injury rates and changes in VO2peak in women associated with aerobic exercise (bench stepping and running). METHODS: A pretest post-test repeated measures design was used to evaluate changes in VO2peak after training for 10 weeks, 3 days per week, for 1 hour per session. Injury incidence was monitored by questionnaires throughout the training program. SETTING: All testing and training took place at Auburn University Montgomery, Montgomery, AL, USA. PARTICIPANTS: The subjects were women enrolled in university physical activity courses. The exercise groups consisted of 23 women who performed bench exercise and 15 who performed running-jogging. Eleven subjects served as non-exercising controls. INTERVENTION: The 10-week exercise training program served as the intervention. MEASURES: Subjects were both pre- and post-tested for VO2peak by open circuit calorimetry. Body composition was estimated from a 7-site skinfold equation. A daily injury log was maintained to evaluate injury status. RESULTS: A repeated measures ANOVA found similar significant improvements in VO2peak for both the bench and running groups with no change for the control group. An evaluation of the injuries graded II or higher found 0.29 injuries per 100 hrs for the bench group and 0.66 injuries per 100 hrs for the running group. When all complaints were considered (grade I to grade IV) the rates increased to 2.44 per 100 hrs for the running group and 6.09 per 100 hrs for the bench group. CONCLUSIONS: Aerobic bench exercise produced similar changes in VO2peak compared to running. The results indicated that the primary injury complaints were grade I and related to delayed onset muscle soreness (DOMS). The bench group experienced an greater incidence of grade I complaints while the running group experienced a slightly greater incidence of more serious grade II or higher injuries.

Increased mast cell density in invasive melanoma.

Mast cell participation in immune responses, tumor progression, and vascularization has been studied extensively in vitro. In situ investigation of mast cells in routinely processed tissues is hampered by difficulty in reliable detection of mast cells. We studied the tissue density of mast cells using a morphometric point-counting technique in 1 microm-thick, Giemsa-stained, tissue sections from epon-embedded samples of skin biopsies. This technique has been demonstrated to be an accurate and reproducible method for determining mast cell density. Mast cell density in 15 cases of invasive melanoma was compared to that of 9 cases of benign melanocytic nevi and 4 cases of melanoma in situ. Mast cell density was greatest in invasive melanoma (mean density = 0.61 vol.%). The mean density of mast cells in nevi and in situ melanoma was 0.33 and 0.5 respectively. Six of 15 cases of melanoma had mast cell densities > 0.6, whereas mast cell density did not exceed 0.6 in any cases of melanoma in situ or benign melanocytic nevi (p < 0.02). Our findings confirm an increase in mast cell tissue density in some cases of invasive melanoma when compared to mast cell density in benign nevi and in situ melanoma.

Self-reports on the Eating Disorder Inventory by female aerobic instructors.

This study examined the possibility of eating disorders in 30 female aerobic dance instructors. All subjects completed a biographical questionnaire and the Eating Disorder Inventory. The results showed that the aerobic instructors yielded scores which were comparable to similarly aged female weight lifters but tended to be lower than those of women distance runners (also of similar age). Interestingly, 23% (n = 7) of the subjects reported a previous history of bulimia and 17% (n = 5) reported a previous history of anorexia. Thus, 40% of the instructors indicated a previous experience with eating disorders. Based on all 30 participants, the mean scores associated with Body Dissatisfaction, Drive for Thinness, Ineffectiveness, and Perfectionism were quite comparable to those previously established for anorexic groups. In addition, a relatively high percentage of the sample yielded scores which were actually greater than mean values associated with anorexia patients on nine of the 11 subscales. Based on these results, a number of the aerobic dance instructors possessed scores suggesting behaviors and attitudes consistent with female athletes whose sports emphasize leanness and comparable to those who have eating disorders.

Bone conduction threshold levels for different bone vibrator types.

This study determined if bone conduction (BC) thresholds were influenced by vibrator type. BC thresholds were obtained for 100 subjects using mastoid placement of Radioear B-71 and B-72 and Pracitronic KH 70 bone vibrators. The nontest ear was masked (30 dB EL) and the ear ipsilateral to the vibrator was open except when testing at 3000 and 4000 Hz when the ear canal was occluded with an earplug to guard against acoustic radiation. BC thresholds at 250 Hz obtained with the B-72 and KH 70 were significantly (p less than .05) higher by 10.5 dB and at 500 Hz were significantly (p less than .05) lower by 5.5 dB than for the B-71. BC thresholds at other frequencies (1000, 2000, 3000, and 4000 Hz) were not significantly different among vibrator types. The findings indicated that reference equivalent threshold force levels (RETFLs) for BC audiometry should be specified by bone vibrator type.