Automated dead-end ultrafiltration of large volume water samples to enable detection of low-level targets and reduce sample variability.

AIMS: A Portable Multi-use Automated Concentration System (PMACS) concentrates micro-organisms from large volumes of water through automated dead-end ultrafiltration and backflushing. The ability to detect microbial targets from ground, surface and cooling tower waters collected using standard methods was compared with samples from the PMACS in this study. METHODS AND RESULTS: PMACS (100 l) and standard grab samples (100-500 ml) were collected from sites in Florida and South Carolina, USA. Samples were analysed for the presence of faecal indicator bacteria (FIB; ground and surface water) or Legionella pneumophila (Lp; cooling tower water). FIB were enumerated by growth on selective media following membrane filtration or in IDEXX defined substrate media. Lp cells were detected by direct fluorescence immunoassay using FITC-labelled monoclonal antibodies targeting serogroups 1, 2, 4 and 6. FIB were found in PMACS samples from ground and surface waters when their concentrations were below detection limits in grab samples. The concentrations of Lp in cooling tower samples collected over 5 months were more consistent in PMACS samples than grab samples. CONCLUSIONS: These data demonstrate that PMACS concentration is advantageous for water monitoring. FIB were detected in PMACS samples when their concentrations were below the detection limits of the standard methods used. PMACS processing provided more representative samples of cooling tower waters reducing sample variability during long-term monitoring. SIGNIFICANCE AND IMPACT OF THE STUDY: This study highlights the utility of PMACS processing for enhanced monitoring of water for low-level microbial targets and for reducing sample variability in long-term monitoring programmes.

Retention of a model pathogen in a porous media biofilm.

The inadvertent or the deliberate introduction of pathogens into drinking water can lead to public health consequences. Distribution system sampling strategies are needed to provide information on the identity, source and fate of the introduced pathogens. Porous media biofilm reactors conditioned with undefined drinking water biofilms were tested for their ability to immobilize Escherichia coli 0157:H7. Biofilms were established by applying continuous flow of biologically activated carbon treated water with natural microflora and supplemented nutrient solution (0.5 mg l(-1) C) for 2 or 3 weeks. Control reactors were clean and were not colonized with biofilm. All reactors were injected with slug doses of approximately 1 x 10(9) cfu E. coli O157:H7. On the basis of the plate count enumeration of the introduced pathogen, reactors pre-colonized for 2 or 3 weeks retained significantly more cells (0.75 and 9.37% of the introduced spike dose, respectively) compared with uncolonized control reactors (0.22%). Compared with cultivation, microscopic direct counts and quantitative PCR suggested significantly higher and lower numbers of pathogens, respectively. Plate counts were thus considered as the method of choice for pathogen enumeration in this study. In addition to providing general insights into interactions between pathogens and drinking water biofilms, the study concluded that engineered biofilm systems may be considered as a device to capture pathogens from the bulk flow for monitoring purposes.

Documented acquired asteroid hyalosis in a case of early diagnosed diabetes mellitus.

BACKGROUND: There have been many reports in the literature of the possible linkage of asteroid hyalosis (AH) to diabetes mellitus (DM). The controversy regarding an association between AH and DM has been one of the longest disputes in the ophthalmic literature. Here we present a case in which AH developed in a patient followed for 9 years after being diagnosed with DM. CASE REPORT: The patient had been examined on nine occasions (since his initial visit in June 1989) and asteroid hyalosis was not discovered until July 1996, when he came in with newly diagnosed diabetes mellitus. This suggests there may well be an association of asteroid hyalosis and diabetes mellitus. DISCUSSION: The patient in this case had a number of risk factors for the development of this ocular condition. He had a long history of systemic arterial hypertension, which has been reported to be linked to the formation of AH. He also had a chronic case of cystoid macular edema, which indicated a vascular compromise to the retinal vessels in the posterior pole, and this leakage may be responsible for serous constituents leaking into the vitreous, which may have caused AH. CONCLUSIONS: This may be the first time in the reported literature that AH was found to occur in a previously normal-appearing vitreous, which was documented over a 9-year period. We would suggest that asteroid hyalosis may be secondary to some form of vasculopathy in many incidences and that diabetes mellitus is one of the conditions that may be associated with the formation of AH.

Demineralization of a wide variety of foods for the renal patient.

OBJECTIVE: To develop the (1) simplest, most efficacious, mineral (phosphorous, potassium, and sodium) reduction procedures applicable to a total dietary selection of foods that will (2) preserve postprocessing food taste and texture expectations. DESIGN: Preprocessing and postprocessing mineral analysis of more than 245 individual samples. SETTING: Analysis of mineral content performed at certified food laboratory in Omaha, NE. PARTICIPANTS: Renal and control volunteers participated as postprocessing test consumers. INTERVENTION: Food materials were subjected to aqueous mineral extraction involving variations in (1) pretreatment handling, (2) aqueous temperatures, and time depending on cell type and initial state (raw, canned, dried). Measurements of remaining mineral concentrations of phosphorous, potassium, and sodium were performed on samples drawn at various time points. MAIN OUTCOME MEASURE: Determination of remaining postprocessing concentrations of target minerals and calculation of the maximum mineral reduction achieved with each food type. RESULTS: The phosphorous reduction range for vegetables, legumes, meats, flours, and cheddar cheese was 51% +/- 33%, 48% +/- 25%, 38.5% +/- 22.5%, 70.5% +/- 13.5%, and 19%, respectively; for potassium, the reduction range for vegetables, legumes, meats, flours, cheddar cheese, and fruit was 59% +/- 40%, 78.5% +/- 20.5%, 57% +/- 41%, 94% +/- 3%, 99%, and 43% +/- 16%, respectively; for sodium, the reduction range for vegetables, meats, and cheddar cheese was 83.5% +/- 14.5%, 67.5% +/- 27.5%, and 97%, respectively. CONCLUSION: Consuming a total dietary selection of demineralized foods is expected to have a significant positive impact on the renal patient's problematic hematologic mineral values and nutritional profile. Reducing food mineral load will make restricted foods permissible once again.

Postoperative pain: a comparison of adolescent inpatient and day patient experiences.

This three-year study investigated the experience of postoperative pain and its management following elective surgery in an adolescent population aged 12-18 years (n=351) in 5 NHS trusts. In addition to the adolescents, one parent of each adolescent and a range of health professionals including surgeons, anaesthetists and registered nurses were interviewed concerning their views on acute pain in adolescent patients. The results presented in this paper are those related to the management of day and inpatient surgery in this adolescent population. Data were collected pre-operatively and postoperatively (days 1 and 3) using semi-structured interviews, telephone interviews, self-completion questionnaires and standardised tools to measure pain intensity (Adolescent Pediatric Pain Tool), psychological adjustment to adolescence (Offer Self-Image Questionnaire-Revised) and emotional state (Hospital Anxiety and Depression Scale). Day cases were discharged on the day of surgery while most inpatients were discharged on the first postoperative day.

Use of response biomarkers in milk for assessing exposure to environmental contaminants: the case for dioxin-like compounds.

Screening for environmental contaminants in milk is generally conducted by chemical analysis, yet such an approach may be time-consuming and expensive, and is not indicative of the physiological consequences of such exposure. The focus of this review is to summarize those constituents of milk that may be altered by maternal exposure to one of the most biologically active environmental pollutants, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and to develop the case for their use as biomarkers of response. Several chemical and/or cellular components of milk are potentially useful as biomarkers, and may be developed as convenient, biologically relevant indicators of maternal exposure to dioxin-like compounds.

Pathophysiology and implications for treatment of acute respiratory distress syndrome.

Acute respiratory distress syndrome is a complex group of signs and symptoms caused by direct or indirect lung injury. In spite of decades of research, it is still associated with a high mortality rate. Pathogenesis of this disease is related to alveolar endothelial and epithelial cell injury and associated release and sequestration of inflammatory mediators and cells, including cytokines and neutrophils, respectively. Pharmacologic interventions have been largely unsuccessful, and ventilation strategies to support oxygenation while limiting ventilator associated lung injury have not demonstrated any significant reductions in the mortality rate. However, novel therapies are in development, based on the knowledge of the pathologic processes of acute respiratory distress syndrome. In this article an overview of the disease process and mediator involvement is presented, followed by a review of pharmacologic and ventilation treatments currently in use or under study.

Postoperative pain assessment and management in adolescents.

A 3-year study investigated the experience and management of postoperative pain following elective surgery in an adolescent sample, using a variety of valid, reliable instruments and semi-structured interviews. In addition to the adolescent subjects, the views of one parent of each adolescent were sought and a sample of health professionals comprising surgeons, anaesthetists and nurses were interviewed about acute pain in adolescent patients. This paper presents some of the main findings pertaining to pain assessment and management. Pain, experienced by most adolescents on the 1st and 3rd postoperative days, was influenced by the presence of anxiety and depression, in addition to the maturational stage; differences between in-patients and day cases are highlighted. Recommendations for practice include the need for more effective pain management and raising awareness of the importance of both psychological state and adjustment to adolescence in this age-group.

Contrasting child and adolescent psychiatry services in Szeged, Hungary, and Glasgow, Scotland.

International comparisons of child and adolescent psychiatry services are rarely reported in the literature. The present study arose out of a TEMPUS collaborative project between the University Departments of Child and Adolescent Psychiatry in Szeged, Hungary, and Glasgow, Scotland. Using the Glasgow Audit Questionnaire, a profile of each service was obtained, including basic demographic data, types of disorders referred, treatment modalities used, and a measure of outcome. The results of this descriptive study indicate that although the two centres were broadly similar, there were major differences in the treatment modalities used. Reasons for the findings are discussed, as are the limitations of the study.

Fluid blood level in cystoid space resulting from central retinal vein occlusion.

BACKGROUND: A hemorrhagic and cystoid maculopathy developed in a patient with a central retinal vein occlusion. There was an unusual finding of a fluid blood level in the inferior region of the central large cystoid space. This clinical finding has been associated with cystoid macular edema after aphakic/pseudophakic cataract surgery. METHOD: A case report is presented and a review of the literature was conducted to determine the frequency of this condition and gain knowledge of the possibility of the pathophysiology. RESULTS: This is only the second case reported in the literature of a fluid blood level seen in a patient with obstructive venous retinopathy. The pathophysiology is likely to be the transitory bleeding of a retinal vessel into the cystoid space. CONCLUSION: The finding of a fluid blood level in a patient with a BRVO or CRVO is a rare event. Since this condition has not been associated with diabetic hemorrhagic retinopathy, any diabetic patient displaying such a clinical finding should be suspected of having obstructive venous disease.

Free-floating vitreous cyst.

Cysts of the vitreous are an unusual clinical finding, with only about 50 such cases reported in the literature. The sizes of the cyst may vary from 0.15 to 12 mm, and they have been found in the anterior and posterior vitreous. The etiology has been theorized to be both congenital and acquired. Acquired cysts may be due to trauma or other forms of intraocular inflammation. Pigmented cysts are believed to originate from the pars ciliaris and nonpigmented cysts are likely to be derived from the remnants of the hyaloidal artery system. The appearances of the cysts are striking and are often seen as clear spherical bodies in the vitreous with interesting interlacing surface patterns. The cysts are benign and are of little significance, except when they encroach on the visual axis and produce visual disturbances (usually floater symptoms).

Juxtapapillary nerve fiber layer infarction as a complication of coronary artery bypass surgery.

BACKGROUND: Recent studies have detailed the prevalence and etiology of ocular complications resulting from coronary artery bypass surgery. Of these, retinal nerve fiber layer infarctions are reported most commonly. The clinical sequelae of nerve infarction may include loss of visual acuity, compromised pupillary function, and visual-field defects (the severity of which may be correlated with the location and extent of the insulted tissue). METHODS: A patient who had experienced bilateral juxtapapillary nerve fiber layer infarction with subsequent loss of visual acuity and peripheral visual field was followed postoperatively for more than 6 weeks. Immediately before our examination, he underwent quadruple coronary artery bypass graft surgery. RESULTS: From the data collected during initial and follow-up examinations, it was determined that the nerve fiber layer infarction was probably the result of a systemic ischemic event during an otherwise uncomplicated surgery. Such events may include hypovolemic blood loss, systemic hypotension during or following surgery, or a host of complications that would prevent adequate perfusion to capillaries in select regions of the eye. CONCLUSION: The pathology of bilateral juxatapapillary nerve fiber layer infarction as a result of substantial transient systemic ischemia may be explained by examining the microcirculation of this region of the retina. Due to certain anatomic and physiologic characteristics, the capillaries supplying the peripapillary zone are most susceptible to arterial vascular events such as ischemia. It is important to recognize this clinical presentation in order to rule out other possible causes for decreased visual acuity and field defects in the postoperative coronary bypass surgery patient.

Serum interleukin-6 levels correlate with the severity of dementia in Down syndrome and in Alzheimer's disease.

INTRODUCTION: Inflammatory processes are suspected in the pathomechanism of Alzheimer's dementia (AD) but the serum and cerebrospinal fluid (CSF) levels of inflammatory cytokines are not yet determined in the different forms of the disorder. SUBJECTS AND METHODS: Interleukin-6 (IL-6) levels were examined in the sera and CSF of patients with mild-moderate and severe stage of late onset sporadic type of AD and in the sera of demented Down syndrome (DS) probands with similar stages of AD and compared with data of age-matched healthy controls. RESULTS: Normal serum IL-6 levels were found in the mild-moderate stage, but significantly increased levels were found in the severe stage of both dementia groups. The CSF concentrations remained within the normal range in all groups. Positive correlations between the serum IL-6 levels and age and the severity of the disease were present. CONCLUSION: These findings suggest a disease stage dependent general activation of the immune system both in sporadic AD and in DS with AD.

The experiential impact of head injury on adolescents: individual perspectives on long-term outcome.

Thirty-one young people, who were experiencing chronic sequelae of a head injury sustained at least 1 year previously, were interviewed in-depth about the impact head injury had had on their lives. Their functioning was also assessed using the Offer Self-Image Questionnaire (OSIQ-R). The main theme raised by subjects was that they had not received adequate explanation of the emotional problems associated with head injury and relevant support in coming to terms with their condition. Head injury had had a devastating effect on their lives, causing limitations in day-to-day activities, employment, education and relationships, and they scored significantly below norms on the OSIQ-R scale of Self-Confidence. However, these young people had a predominantly positive attitude towards life, which appeared to be related to their appreciation of how fortunate they had been to survive. They scored significantly above norms on the OSIQ-R scale of Social Functioning. Markers of poor functioning were identified and, in clinical practice, could be used as a method of highlighting those head-injured young people who potentially are most in need of support. The findings have implications for future research directions, service delivery and planning, in that particular weaknesses of current provision are demonstrated and recommendations made for improvements.

Physiological stress in batch cultures of Pseudomonas putida 54G during toluene degradation.

Physiological stress associated with toluene exposure in batch cultures of Pseudomonas putida 54G was investigated. P. putida 54G cells were grown using a continuous vapor phase feed stream containing 150 ppmv or 750 ppmv toluene as the sole carbon and energy source. Cells were enumerated on non-selective (R2A agar plates) and a selective minimal medium incubated in the presence of vapor phase toluene (HCMM2). Differential recovery on the two media was used to evaluate bacterial stress, culturability and loss of toluene-degrading capability. A majority of the bacteria were reversibly stressed and could resume active colony formation on selective medium after passage on non-selective medium. A small fraction of the bacterial cells suffered an irreversible loss of toluene degradation capability and were designated as Tol- variants. Numbers of stressed organisms increased with duration of toluene exposure and toluene concentration and coincided with accumulation of metabolic intermediates from incomplete toluene degradation. Respiring cell numbers in the batch cultures decreased as injury increased, indicating a possible relationship between respiring and injured cells. Rate expressions for injury, for formation of Tol- variants and for growth of Tol- variants were determined by calibrating a theoretical model to the results obtained. These rate expressions can be used to calibrate bioreactor models, and provide a basis for better design and control of bioremediation systems.

Road traffic accidents: early psychological consequences in children and adolescents.

BACKGROUND: Although road traffic accidents are a major cause of injury and death in children and adolescents, research into their psychological consequences consists mainly of case reports. METHOD: A prospective study was made of young road traffic accident victims: 57 subjects, aged 5-18 years, who had been injured in road traffic accidents, and their parents, were interviewed 2-16 days post-accident and re-examined after 12-15 weeks. RESULTS: Post-accident stress symptoms occurred at both times. There was a decrease of symptom severity between the two interviews, but at the later time, 14% still suffered from moderate or severe post-traumatic stress disorder, 17% from serious traffic-related fears, and parents reported increased mood disturbance in their children compared with the pre-accident period. High levels of distress during and immediately after the accident were associated with severe post-traumatic stress symptoms. CONCLUSIONS: There is an urgent need for healthcare staff working with children and adolescents involved in road traffic accidents to be aware of the potential psychological consequences and the importance of the immediate accident experience on subsequent coping.

Physiological and chemical gradients in a Pseudomonas putida 54G biofilm degrading toluene in a flat plate vapor phase bioreactor.

A Pseudomonas putida 54G biofilm was grown on toluene vapor supplied as the sole external carbon and energy source in a flat plate biofilm reactor. Enumerations of cells in the biofilm were made using culture techniques (selective and nonselective for toluene) and microscopic techniques (total and respiring cells), and an analysis of the progression of the state of the culture was made by examination of various fractions of the populations. Long-term exposure to higher levels of toluene produced the following trends: (i) lower fraction of total cells that respired; (ii) lower fraction of culturable cells that also grew on toluene; (iii) higher fraction of respiring cells that could not grow on toluene plates; and (iv) a relatively constant fraction of total cells that could not be cultured on toluene. Respiration rate was determined using oxygen microsensors, and the fraction of the total respiration that was not associated with toluene uptake increased with higher toluene exposure. A combination of cryosectioning and respiration rate data was used to demonstrate that more respiring cells and a higher respiration rate both occurred at the base of the film, suggesting a deterioration in physiological state with continued exposure to toluene. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 361-371, 1997.

Effect of growth conditions and substratum composition on the persistence of coliforms in mixed-population biofilms.

Laboratory reactors operated under oligotrophic conditions were used to evaluate the importance of initial growth rate and substratum composition on the long-term persistence of coliforms in mixed-population biofilms. The inoculum growth rate had a dramatic effect on the ability of coliforms to remain on surfaces. The most slowly grown coliforms (mu = 0.05/h) survived at the highest cell concentration. Antibody staining revealed that Klebsiella pneumoniae existed primarily as discrete microcolonies on the surface. Both coliforms and heterotrophic plate count bacteria were supported in larger numbers on a reactive substratum, mild steel, than on polycarbonate.