Widespread collaboration of Isw2 and Sin3-Rpd3 chromatin remodeling complexes in transcriptional repression

The yeast Isw2 chromatin remodeling complex functions in parallel with the Sin3-Rpd3 histone deacetylase complex to repress early meiotic genes upon recruitment by Ume6p. For many of these genes, the effect of an isw2 mutation is partially masked by a functional Sin3-Rpd3 complex. To identify the full range of genes repressed or activated by these factors and uncover hidden targets of Isw2-dependent regulation, we performed full genome expression analyses using cDNA microarrays. We find that the Isw2 complex functions mainly in repression of transcription in a parallel pathway with the Sin3-Rpd3 complex. In addition to Ume6 target genes, we find that many Ume6-independent genes are derepressed in mutants lacking functional Isw2 and Sin3-Rpd3 complexes. Conversely, we find that ume6 mutants, but not isw2 sin3 or isw2 rpd3 double mutants, have reduced fidelity of mitotic chromosome segregation, suggesting that one or more functions of Ume6p are independent of Sin3-Rpd3 and Isw2 complexes. Chromatin structure analyses of two nonmeiotic genes reveals increased DNase I sensitivity within their regulatory regions in an isw2 mutant, as seen previously for one meiotic locus. These data suggest that the Isw2 complex functions at Ume6-dependent and -independent loci to create DNase I-inaccessible chromatin structure by regulating the positioning or placement of nucleosomes.

An RGD sequence in the P2Y(2) receptor interacts with alpha(V)beta(3) integrins and is required for G(o)-mediated signal transduction

The P2Y(2) nucleotide receptor (P2Y(2)R) contains the integrin-binding domain arginine-glycine-aspartic acid (RGD) in its first extracellular loop, raising the possibility that this G protein-coupled receptor interacts directly with an integrin. Binding of a peptide corresponding to the first extracellular loop of the P2Y(2)R to K562 erythroleukemia cells was inhibited by antibodies against alpha(V)beta(3)/beta(5) integrins and the integrin-associated thrombospondin receptor, CD47. Immunofluorescence of cells transfected with epitope-tagged P2Y(2)Rs indicated that alpha(V) integrins colocalized 10-fold better with the wild-type P2Y(2)R than with a mutant P2Y(2)R in which the RGD sequence was replaced with RGE. Compared with the wild-type P2Y(2)R, the RGE mutant required 1,000-fold higher agonist concentrations to phosphorylate focal adhesion kinase, activate extracellular signal-regulated kinases, and initiate the PLC-dependent mobilization of intracellular Ca(2+). Furthermore, an anti-alpha(V) integrin antibody partially inhibited these signaling events mediated by the wild-type P2Y(2)R. Pertussis toxin, an inhibitor of G(i/o) proteins, partially inhibited Ca(2+) mobilization mediated by the wild-type P2Y(2)R, but not by the RGE mutant, suggesting that the RGD sequence is required for P2Y(2)R-mediated activation of G(o), but not G(q). Since CD47 has been shown to associate directly with G(i/o) family proteins, these results suggest that interactions between P2Y(2)Rs, integrins, and CD47 may be important for coupling the P2Y(2)R to G(o).

The environmental impact of heavy metals from sewage sludge in ferralsols (São Paulo, Brazil)

The spreading of sewage sludge on acidic ferralsol soil was simulated in a column experiment in order to estimate the potential impact on water and soil quality. Drainage and runoff water were sampled daily over a 2-month experiment and analysed for Fe, Ni, Cu, Pb and DOC. Results show a clear influence of the sludge on the water quality, especially at the start of the experiment, increasing the export of Cu, Ni, Pb and in DOC from the soil, mainly in dissolved form. Nickel was usually the most mobile element in the sludge and in the soil. In the soil, Pb mobility was complex and increased drastically with time compared to the other elements. No significant increase in soil heavy metal content due to the sludge spreading was recorded on this time scale.

Alkalinity measurements within natural waters: towards a standardised approach

A discussion on the measurement of alkalinity in bicarbonate bearing and acidic waters is presented as a move towards developing a standardised approach within the aquatic sciences. The discussion is based on theoretical and practical considerations. Practical illustrations are provided from measurements of calcium bicarbonate bearing waters (River Thames) and acidic to near neutral waters from acidic soil systems with calcium bearing groundwater sources (the mid-Wales region and the Scottish Dee basin). A comparison of single endpoint and Gran procedures is made and the various error terms assessed. It is concluded that single endpoint and Gran methodologies are applicable in the standard pH titration used in aquatic research (pH 4.5-4.0). However, analytical errors increase, particularly for the single endpoint titration, the lower the endpoint/endpoint-range in pH. For the Thames, the value of a single endpoint over a Gran procedure is illustrated. The Thames results show that some buffering components may still be titrated out within the Gran titration range used: this leads to an underestimate in the alkalinity. Indeed, by making a comparison between single endpoint and Gran alkalinity measurements, the Thames results indicated the presence of unexpected buffering components: the interrogative nature of this type of analysis is highlighted. A standardised approach is outlined.

Use of continuous water quality records for hydrograph separation and to assess short-term variability and extremes in acidity and dissolved carbon dioxide for the River Dee, Scotland

A combination of continuous (15-min) pH, conductivity and temperature measurements and fortnightly spot-sampled water quality data were used to examine temporal variability and extremes in river water quality in an upland Scottish river: the River Dee at Mar Lodge. An empirical relationship was established for Gran-alkalinity by multiple regression against flow and conductivity for the fortnightly data. Applying this relationship to the continuous data, an estimate of continuous Gran-alkalinity was calculated. The continuous Gran-alkalinity record was used as (1) a conservative tracer in a simple two-component mixing model to determine the relative proportions of near-surface runoff and deeper groundwater contributing to stream flow; (2) to deconvolute the contribution of weathering and sea-salt contributions to stream conductivity; and (3) to calculate the excess partial pressure of carbon dioxide in stream water. The episodic variations in pH, weathering and sea-salt conductivity and excess partial pressures of carbon dioxide (EpCO2) associated with high flow events in the River Dee suggest that hydrological pathways play an important role in determining stream chemistry. The results of the hydrograph separation indicate that groundwater provides an important contribution to stream flow, and that there are large and hydrologically active stores of groundwater within the upper River Dee catchment. Sea-salts have an important influence on stream conductivity, particularly with the onset of storm runoff following summer drought periods. This suggests that sea-salts are concentrated in the upper soil horizons by dry deposition and/or evapotranspiration. EpCO2 behaves non-conservatively and shows marked diurnal variability under low-flow conditions during summer, inducing diurnal pH variations, and indicating the importance of within-river biological processes. This study emphasises the very intermittent nature of water quality extremes with stream spates and the diurnal nature of biologically-induced responses. Fortnightly sampling programmes do not capture the range of high flow extremes, and with sampling undertaken during the working day, biological extremes occurring at night are also missed, introducing bias. This study shows the value of continuous measurements for infilling aspects of these intermittent extremes. However, it is also noted that the relatively simple patterns of response observed from the continuous measurements may well belie a much more varied response at the sub-catchment and hillslope scales, as local chemical and hydrological heterogeneities do occur. Thus, the two-component mixing model used is, in practice, based on catchment integrated values for a range of soil water and groundwater endmembers.

Environmental change, land use and water quality in Scotland: current issues and future prospects

An outline of both the scientific and management needs facing the future water quality issues of Scotland is discussed. The scientific needs are considered in terms of monitoring to increase the understanding of hydrochemical processes, issues of scaling, and the need for improved modelling under changing environmental processes. In terms of the management needs, the requirements highlighted relate to improving the ecological quality of Scottish rivers and the implementation of integrated river basin management plans.

Association of the cyclin-dependent kinases and 14-3-3 sigma negatively regulates cell cycle progression

14-3-3 sigma, implicated in cell cycle arrest by p53, was cloned by expression cloning through cyclin-dependent kinase 2 (CDK2) association. 14-3-3 sigma shares cyclin-CDK2 binding motifs with different cell cycle regulators, including p107, p130, p21(CIP1), p27(KIP1), and p57(KIP2), and is associated with cyclin.CDK complexes in vitro and in vivo. Overexpression of 14-3-3 sigma obstructs cell cycle entry by inhibiting cyclin-CDK activity in many breast cancer cell lines. Overexpression of 14-3-3 sigma can also inhibit cell proliferation and prevent anchorage-independent growth of these cell lines. These findings define 14-3-3 sigma as a negative regulator of the cell cycle progression and suggest that it has an important function in preventing breast tumor cell growth.

Loaded hydroxylapatite-coated implants and uncoated titanium-threaded implants in distracted dog alveolar ridges

AIMS

The aim of this study was to determine the response of alveolar bone after it was augmented vertically with distraction osteogenesis, implanted with hydroxylapatite (HA)-coated implants and noncoated titanium-threaded implants, and subsequently loaded for 1 year.

METHODS

Eight dogs each had 4 implants placed horizontally into an edentulous mandibular quadrant. After integration, a distraction osteogenesis device was fabricated in the laboratory. An osteotomy was made to allow the crest of the alveolar ridge to be distracted vertically. After 10 mm of vertical distraction, the distraction devices were stabilized with light cured resin. After bone fill of the distraction gap was radiographically confirmed in all dogs at 10 weeks, 2 implants were placed into the ridges. Four dogs had threaded titanium implants placed, and 4 dogs had threaded HA-coated implants placed, with 1 implant in the distracted bone and 1 implant in adjacent nondistracted bone, for both groups. After 4 months for implant integration, bridges were fabricated and secured to the implants with screws. Crestal bone levels were evaluated by radiographs through 1 year of function. Animals were killed after 1 year of loading for histologic evaluation.

RESULTS

The vertical ridge augmentation averaged 8.8 +/- 1.0 mm after 10 weeks of healing after distraction. Analysis of variance indicated a significantly greater change from baseline for HA-coated implants and for distracted bone sites. Histologic examination showed that bone had formed between the distracted segments creating an augmented ridge. The average thickness of the labial cortex in the distraction gap was significantly thinner than the lingual cortex in distracted bone or the lingual and labial nondistracted cortical bone. The presence of a dental implant did not significantly affect cortical bone thickness. Serial sections showed that implants remained integrated and functional without soft tissue inflammation.

CONCLUSION

Dental implants placed into alveolar ridges augmented with the technique of distraction osteogenesis were functional for the length of this study.

The water quality of the River Kennet: initial observations on a lowland chalk stream impacted by sewage inputs and phosphorus remediation

The water quality of seven sites on the upper reaches of the River Kennet round the market town of Marlborough is described and related to the introduction of phosphorus treatment of effluent from Marlborough sewage treatment works (STW). The River Kennet is mainly groundwater-fed from a Cretaceous chalk aquifer and hence the river water is calcium- and bicarbonate-bearing and has a relatively constant composition of many major water quality determinants. In-stream biological activity gives rise to marked diurnal fluctuations in pH (of approx. 0.8 units). Dissolved carbon dioxide and dissolved oxygen also show marked diurnal fluctuations. Dissolved carbon dioxide varies from approximately 10 to 70 times atmospheric pressure, indicating net release of carbon dioxide and the dominance of heterotrophic (respiratory) processes over autotrophic processes (photosynthesis). Much of the excess carbon dioxide is probably associated with carbon dioxide laden groundwater inputs and the relatively short within-stream residence times ensures only limited degassing to the atmosphere. Diurnal fluctuations in dissolved oxygen vary from approximately 20% to 200% saturation. For both dissolved carbon dioxide and dissolved oxygen, the amplitude of fluctuations is much lower during the winter period, when biological activity is at its lowest. The concentrations of soluble reactive phosphorus (SRP), total phosphorus (TP) and boron increase markedly just downstream of the sewage works as a result of this point source input. These concentrations slowly decline further downstream as additional groundwater inputs dilute the effluent further. The introduction of chemical treatment of sewage effluent for phosphorus reduction at Marlborough STW resulted in a marked decrease in within-river SRP and TP concentrations to levels approximately the same as those upstream of the STW. A comparison of SRP and boron concentrations reveals a reduction in in-stream SRP concentrations by approximately 75% following effluent treatment. In terms of within-river processes controlling in-stream phosphorus concentrations, previous studies have indicated that one potentially important mechanism within calcium bicarbonate bearing rivers may be related to co-precipitation of phosphorus with calcium carbonate (calcite). The present study shows that the waters are oversaturated with respect to calcium carbonate, that no equilibrium conditions exist and that phosphorus removal has led to undetectable changes in calcium carbonate oversaturation. Hence, it is concluded that the primary changes in phosphorus levels within the river is directly associated with changing point source contributions from the STW and physical dilution within the river. However (1) the results relate to only the first year of study and subsequent differences may become apparent and (2) reactions between the water column and plant and bottom sediment interfaces may be important in regulating phosphorus fluxes within the river. The results presented in this paper mark a pilot phase of a longer-term initiative and this paper provides a background setting. The paper discusses the longer-term objectives and important gaps in knowledge of the system that requires further address.

Conclusions to the special issue of Science of the Total Environment concerning 'The water quality of UK rivers entering the North Sea'

This paper presents an overview of the water quality functioning of eastern UK rivers draining into the North Sea. It summarises the results of three special issues of Science of the Total Environment and related work and complements a companion bibliography (Neal and Turner, 2000, this volume). The rivers are described in straightforward broad terms, and the reader is guided via the bibliography to the special volumes for the detailed findings. The water quality is shown to be highly variable over space and time. The changes over the past 300 years reflect first the transition from a rural society to the major impact of the industrial revolution and subsequently to one of the worlds' most successful environmental cleanups. The present water quality reflects the relative impacts of diffuse agricultural sources, urban and industrial point source discharges together with background inputs associated with geology: all these can be modified by within-river processes associated with physical mixing, biology and inorganic reactions. The work is set within the context of water quality, modelling and flux outputs to the North Sea and contemporary and future environmental research and management needs. A range of environmental impact studies is included. The detailed information is now available on a major and easily accessible database.

The water quality of the River Thames at a rural site downstream of Oxford

Water quality information is presented for the River Thames 34 km downstream of the market town of Oxford in Oxfordshire to provide an overview of the hydrochemical functioning of a major agriculturally impacted river entering the North Sea. The data, which cover the period from the spring of 1997 to the spring of 1999, relate to three types of data. These types are: (1) weekly spot sampling for determination of major, minor and trace elements, pH, alkalinity and herbicides; (2) tri-weekly spot sampling for pH, alkalinity and dissolved silicon; and (3) continuous measurements of pH and dissolved oxygen. Calcium and bicarbonate provide, respectively, the dominant cation and anion in solution and their compositions remain relatively constant through time, irrespective of flow levels. In contrast, many determinands show seasonally related fluctuations. Concentrations for most of the major anions, sodium, potassium as well as soluble reactive phosphorus and several soluble trace elements such as boron, antimony, arsenic and molybdenum decrease as flow increases. A reverse pattern is observed for nitrate, some herbicides and trace elements associated with particulate phases: concentrations increase with increasing flow. These patterns reflect the influence of: (1) a calcium carbonate rich groundwater system which provides the main stream flow component; (2) dilution of point source pollutant inputs associated with sewage and possibly light industry at high flows for several major, nutrient and trace elements; (3) enhanced nitrate and herbicide runoff from agricultural land at high flows; (4) enhanced microparticulate trace metal levels associated with increased suspended sediment loads at high flows; and (5) biological processes which affect pH, dissolved silicon, dissolved carbon dioxide and dissolved oxygen levels. An examination of soluble reactive phosphorus (SRP) and boron relationships reveals a reduction in concentrations for SRP associated possibly with phosphorus removal from a major sewage treatment works on an upstream tributary of the Thames, the Thame.

Temporal and small-scale spatial variations of dissolved oxygen in the Rivers Thames, Pang and Kennet, UK

Small-scale spatial dissolved oxygen concentrations were measured on three rivers by taking a number of transects along a river reach. Temporal (diurnal) variations were measured by use of continuous (15-min) monitors located at the mid-transect of the spatial observations. Spatial variation of dissolved oxygen concentrations were found to be relatively small (approx. +/- 10% dissolved oxygen) and biologically insignificant compared to diurnal changes under conditions of high productivity (approx. +/- 60% dissolved oxygen). The diurnal curves were analysed in order to estimate values of reaeration, photosynthesis and respiration on a daily basis for almost 3 months using process-based analytical techniques (the Delta and Hornberger and Kelly methods). The River Kennet was shown to be the most productive river followed by the River Pang and then the River Thames. The patterns of reaeration, photosynthesis and respiration and the behaviour of the three rivers are discussed.

A summary of river water quality data collected within the Land-Ocean Interaction Study: core data for eastern UK rivers draining to the North Sea

A numerical summary of the water quality of rivers draining into the North Sea from the eastern UK is presented using core information collected within the Land-Ocean Interaction Study (LOIS) and a companion study by the Institute of Hydrology. The analysis is based on weekly monitoring for periods from 1993 to 1999 for major, minor, nutrient, trace and other water quality determinand chemistry. The data cover rivers ranging from the rural Tweed in southeastern Scotland, to the urban and industrially impacted Wear and Humber rivers in the north and central England and two agriculturally impacted rivers in the south of England (Great Ouse and Thames). Within the analysis, monthly averaged concentrations are plotted to show the seasonality. The summary provides specific information on the water quality of UK rivers which is of use in developing European and global initiatives for assessing pollutant inputs to estuarine, coastal and open-sea environments.

A bibliography for the conclusions to the special issue of Science of the Total Environment concerning 'The water quality of UK rivers entering the North Sea'. Sci. Tot. Environ., this volume

In this document, a bibliography for the conclusions to the special issue of Science of the Total Environment concerning 'The water quality of UK rivers entering the North Sea'. Sci. Tot. Environ., this volume, is presented. It comprises a list of the papers presented in five special issues in learned journals, three in Science of the Total Environment (this volume and volumes 194/195, 1997 and 210/211, 1998) as well as Hydrological Processes (1999, vol 13: Special Issue, River Basin Sediment Dynamics, eds. Anderson, M.G., Peters, N.E. and Walling, D.E.) and Marine Pollution Bulletin [1999, vol 37(3-7) Special Issue: Flux of Materials between Rivers and Coastal Waters, eds. Stebbing, A.R.D., Huntley, D. and Leeks, G.J.L.]. The bibliography comprises six main sections with subsections for specific water quality issues. These are as follows: Section 1 deals with the introduction to LOIS and contained in this section is background material over the nature of the programme, the study area, remit, water quality issues and international context. Section 2 provides the main meat to the bibliography and it splits into Section 2.1 historical and Section 2.2 current water quality issues. Within Section 2.2 there are subsections dealing with specific current aspects of water quality (Section 2.2.1, major ions; Section 2.2.2, pH, dissolved carbon dioxide and dissolved oxygen; Section 2.2.3 nutrients; Section 2.2.4, trace elements; Section 2.2.5 micro-organics; Section 2.2.6 sediments; Section 2.2.7 biology). Section 3 deals with hydrology and climate variability, Section 4, modelling, Section 5 load estimation and Section 6 conclusions. A full listing of the LOIS programme is available from the LOIS programme office, CCMS, Plymouth Laboratory, Prospect Place, West Hoe, Plymouth, PL1 3DH, UK (e-mail lois@ccms.ac.uk).

The water quality of the Great Ouse

The results of a 1-year detailed water quality study of the Great Ouse are presented. Being recharged to an important degree from groundwater sources within the carbonate bearing bedrock, the waters are enriched in base cations and they are of relatively high alkalinity (approx. 4000 microEq./l) and pH (approximately 8). Many chemical constituents such as sodium, chloride, boron, nitrate and soluble reactive phosphorus vary over time in response to changing flow conditions. For most determinands, concentrations decrease with increasing flow in response to dilution of point and groundwater sources by rainfall. However, for barium and nitrate, concentrations increase with flow and this is indicative of increased runoff from the agriculturally impacted soils. While this feature is certainly expected for nitrate due to fertiliser application, the pattern for barium is at face value unexpected as it would normally be expected to behave like other divalent base cations such as calcium, coming from aquifer leaching. However, it seems that agricultural disturbance of the land can also lead to enhanced runoff: a feature now becoming apparent in several UK studies. The concentrations of micro-organic herbicides vary over time in response to the different times of application and only isoproturon shows a clear response to varying flow conditions. With regards to biological processes, this is manifest by changes in pH, dissolved carbon dioxide and silica. At most times of the year the waters are oversaturated with respect to atmospheric CO2 (EpCO2) by a factor of approximately 6 and at these times pH is approximately 7.7 and silica concentrations are approximately 4 mg-Si/l. However, in the early spring period pH increases to values over 8, EpCO2 declines to about the atmospheric levels and silica declines to approximately 1 mg-Si/l. This change probably reflects the dynamic diatom blooms and decays common in this river.

The water quality of a tributary of the Thames, the Pang, southern England

The water quality of a tributary of the Thames, the Pang, draining a rural part of the Thames basin is described and related to the influences of inputs from farming activity and groundwater from the underlying chalk aquifer as modified by biological within-stream processes. The groundwater inputs ensures that the waters are calcium and bicarbonate bearing and have relatively uniform concentrations. Agricultural inputs result in enhanced levels of nutrients, nitrate and soluble reactive phosphorus (SRP) in particular. For nitrate, the concentrations are higher during the winter months due to increased surface runoff. In contrast, SRP shows a more erratic behaviour with higher concentrations occurring during the early storm hydrograph rise following summer baseflow recession. Within the stream, biological activity results in: (a) marked diurnal fluctuations in the dissolved levels of carbon dioxide and oxygen; (b) a strong seasonal pattern in chlorophyll a levels; and (c) dissolved silica concentration reductions during the early spring period. Carbon dioxide levels are particularly high in the groundwater (typically approximately 60 times the atmospheric value) as observed at a spring discharge. However, within the stream, considerable degassing occurs although values remain an order of magnitude above atmospheric pressure. The findings are discussed in the context of the water quality functioning of agriculturally and sewage impacted southern eastern UK rivers. For example, the work shows that unlike for riverine systems with point sewage discharges or limited groundwater storage, there is a very poor link between chemical concentrations and flow even for components such as SRP and boron which are often connected to sewage discharges.

Riverine inputs of major ions and trace elements to the tidal reaches of the River Tweed, UK

This paper examines spatial and temporal variability in freshwater inputs of trace elements and major ions to the tidal reaches of the River Tweed. The relationships between concentrations of major ions and trace elements (in dissolved and acid-available particulate forms) and flow are examined, and a simple two-component endmember mixing analysis performed to link river water chemistry to catchment sources, and to identify whether within-river processes modify concentrations to produce non-conservative behaviour. The results indicate that most dissolved major ions and trace elements behave conservatively in the lower reaches of the River Tweed, the variability in concentrations being dominated by hydrology and the existence of different high-flow and low-flow endmember runoff chemistries. This suggests that the variability in concentration of most dissolved trace elements and major ions in the lower Tweed can be modelled using simple mixing relationships. However, the relationships between pH, Ca, Mg and Gran alkalinity show pronounced non-conservative behaviour, indicating the importance of understanding within-river process for modelling these determinants. The non-conservative behaviour identified is related to biological controls and the resultant diurnal variations in pH which promote daytime removal of Ca from solution by precipitation of calcium carbonate (and corresponding removal of Mg by co-precipitation) during extreme low-flow conditions and algal blooms during the summer.

Phosphate measurement in natural waters: two examples of analytical problems associated with silica interference using phosphomolybdic acid methodologies

Assessment of phosphate species for bicarbonate-bearing lowland rivers of the Thames valley, England and acidic Welsh upland streams (the Plynlimon area, mid-Wales) reveal problems of silica interference when employing standard automated 'phosphomolybdic acid' colorimetric methodologies. The interference occurs under a combination of two conditions: (1) when the reagents and samples are heated to speed up the rate of formation of phosphomolybdic acid; and (2) when the strength of a sulfuric acid reagent is too low. While this paper alerts researchers to potential analytical problems with silica interference within phosphomolybdic acid methodologies to determine soluble reactive phosphorus (SRP) concentrations, it cannot detail whether or not there is a general problem. This lack of specificity occurs because there are a variety of phosphomolybdic acid methodologies available which vary in their reagent recipes and it is not clear which methods will or will not suffer from silica interference. Changing the sulfuric acid reagent strength by a factor of two overcame the problem, in this case, with regards to the determination of soluble reactive phosphorus. However, even here, the method may not be applicable to very high alkalinity waters owing to their potential for reducing the acidity of the analyte. With regard to total dissolved phosphorus (TDP) and total phosphorus (TP) measurements, the importance of undertaking the analysis under ambient conditions is clearly shown. There are many small variants on standard phosphomolybdate methods for determining SRP, TDP and TP in use and it is not always clear which methods will or will not show silica interference for particular water types. It is therefore recommended that individual laboratories check their methodologies for silica interference using phosphate-free solutions with similar silica and alkalinity ranges for the waters being assayed.

River water quality in the Humber catchment: an introduction using GIS-based mapping and analysis

The regional water quality of the Humber catchment was mapped for key inorganic chemical determinands using a GIS system and an extensive Environment Agency and LOIS monitoring database. The resultant maps revealed the major factors affecting the general characteristics of regional water quality. Sewage inputs from industrial and domestic sources account for the high concentration of many determinands in urban areas. The concentrations of particulate components increase in tidal zones because of sediment trapping and tidal re-suspension effects. Some determinands also exhibit localized high concentrations related to coal mine drainage, soil pollution caused by past ore mining, bedrock geology, the agricultural use of fertilizers and the ingression of seawater into the estuary.

Frequency of BRCA1/BRCA2 mutations in a population-based sample of young breast carcinoma cases

BACKGROUND

There is a clear and growing need for data regarding BRCA1 and BRCA2 mutation frequencies among breast carcinoma cases not specifically ascertained on the basis of extreme family history profiles. Toward this end, the authors previously reported results with regard to BRCA1 in breast carcinoma patients drawn from a population-based study. In the current study the authors present new findings concerning BRCA2 mutation frequency in this same population, as well as summary data regarding the combined contribution of these two genes.

METHODS

Subjects were drawn from two population-based, case-control studies of breast carcinoma in young women conducted in western Washington State and focused on 1) women diagnosed with breast carcinoma before age 35 years (n = 203); and 2) women with a first-degree family history of breast carcinoma who were diagnosed before age 45 years (n = 225). Similarities and differences between BRCA2 carriers and BRCA1 carriers were analyzed in terms of age at diagnosis, family history status, and disease features.

RESULTS

Of cases diagnosed before age 35 years, all of whom were unselected for family history, 9.4% carried germline mutations (3.4% for BRCA2 and 5.9% for BRCA1). Of cases diagnosed before age 45 years who had a first-degree family history of breast carcinoma, 12.0% carried germline mutations (4.9% for BRCA2 and 7.1% for BRCA1). Increased frequencies of mutations were observed in cases with a personal or family history of early age at diagnosis and in those with four or more family members affected with breast carcinoma. BRCA2 mutations were less common than BRCA1 mutations in families with any history of ovarian carcinoma.

CONCLUSIONS

Overall, given current constraints on health care resources, these data suggest that screening for germline mutations in these breast carcinoma susceptibility genes may have the greatest impact on overall health care if it is prioritized toward high and moderate risk populations.

Flumazenil in drug overdose: randomized, placebo-controlled study to assess cost effectiveness

OBJECTIVE

To investigate cost effectiveness of administration of flumazenil to patients presenting with suspected acute drug overdose.

DESIGN

Double-blind, prospective, placebo-controlled randomized study.

SETTING

University teaching hospital.

PATIENTS

Forty-three adults presenting with suspected drug overdose and having a Glasgow Coma Scale (GCS) score of <13. Patients with known benzodiazepine/tricyclic ingestion were excluded.

INTERVENTIONS

Intravenous administration of flumazenil (up to 2 mg) or placebo.

MEASUREMENTS AND MAIN RESULTS

Individual patient costs were assessed and data aggregated for each treatment group. Major diagnostic and therapeutic interventions were recorded and between group comparisons performed. Clinical response to study drug administration was assessed by obtaining pre- and post-drug GCS scores and observation of the patient for at least 180 mins for signs of resedation. Aggregate cost or number of major diagnostic and therapeutic interventions were not different between groups. Patients randomized to the flumazenil group showed a marked increase in GCS score (7.4 to 11.8) compared with those in the placebo group (8.2 to 8.6).

CONCLUSION

Use of flumazenil in intentional drug overdose of unknown etiology is not cost effective.