The diverse environmental burden of city-scale urban water systems.

Recent years have seen an increase in the use of Life Cycle Assessment (LCA) to inform urban water systems research. The attraction of LCA is its capacity to identify trade-offs across a broad range of environmental issues and a broad range of technologies. However, without some additional perspective on the scale of the results, prioritisation of these concerns will remain difficult. LCA studies at the whole-of-system level are required to identify the diversity of life cycle environmental burdens associated with urban water systems, and the main contributors to these impacts. In this study, environmental impact profiles were generated for two city-scale urban water systems: one typical of many urban centres, with a high reliance on freshwater extraction and the majority of treated wastewater being discharged to the sea; and one that adopts a more diverse range of water supply and wastewater recycling technologies. The profiles were based on measured data for most system components, otherwise best available empirical data from the literature. Impact models were chosen considering the substantial methodological developments that have occurred in recent years. System operations, directly within the sphere of influence of water system managers, play the dominant role in all but one of the 14 life cycle impact categories considered. While energy use is the main cause of changes in the impact profiles when the alternative water supply technologies are included, it is not the only important driver of impacts associated with city-scale urban water systems. Also extremely important are process emissions related to wastewater treatment and dams (notably fugitive gases, wastewater discharges, and biosolids disposal). The results clearly indicate a diverse range of environmental impacts of relevance, extending beyond the traditional concerns of water use and nutrient discharge. Neither energy use, nor greenhouse gas footprints, are likely to be an adequate proxy for representing these additional concerns. However, methodological improvements will be required for certain LCA impact models to support future case study analysis, as will a comprehensive critique of the implications from selecting different impact models.

Endogenous marinobufagenin-like immunoreactive factor and Na+, K+ ATPase inhibition during voluntary hypoventilation.

In previous studies investigators found that conditioned hypoventilatory breathing potentiated a sodium-sensitive form of hypertension in dogs that was not mediated by sympathetic nervous system arousal. Our study investigated effects of 30 minutes of voluntary hypoventilation, maintained by a respiratory gas monitor and feedback procedure, in 16 normotensive humans of both sexes on (1) plasma concentrations of endogenous digitalis-like factors (ouabain-like and marinobufagenin-like immunoreactivity), (2) activity of erythrocyte Na+, K+ -ATPase, (3) inhibitory activity of plasma Na+, K+ -ATPase, and (4) blood pressure. Increased end tidal PCO2 (41 +/- 0.78 mm Hg versus 37.6 +/- 1.03 mm Hg) was associated with (1) an increase in plasma marinobufagenin-like immunoreactivity (1.23 +/- 0.47 versus 4.96 +/- 1.19 nmol/L), (2) an inhibition of Na+, K+ -ATPase in red blood cells (3.68 +/- 0.22 versus 2.15 +/- 0.25 mmol Pi/mL-1/h-1; P < .01), (3) increase in plasma Na+, K+ -ATPase inhibitory activity (34.9 +/- 4.0% versus 48.8 +/- 2.1%, P < .02), and (4) increases in systolic (112.4 +/- 2.6 versus 107.6 +/- 1.8 mm Hg) and diastolic (73.5 +/- 2.1 versus 68.8 +/- 2.1 mm Hg) blood pressures. Plasma levels of ouabain-like immunoreactivity did not increase significantly. Incubation of erythrocytes obtained during hypoventilation with antidigoxin antibody restored the Na+, K+ -ATPase activity (3.99 +/- 0.34 mmol Pi/mL-1/h-1). Cessation of hypoventilation was associated with decreases in diastolic blood pressure (70.5 +/- 2.2 mm Hg) and restoration of Na+, K+ -ATPase activity in erythrocytes (2.99 +/- 0.43 mmol Pi/mL-1/h1).(ABSTRACT TRUNCATED AT 250 WORDS)

Frequency of trisomy 20 in nonmalignant bronchial epithelium from lung cancer patients and cancer-free former uranium miners and smokers.

Lung cancer is the leading cause of cancer-related deaths. The development of sensitive screening methods to identify at-risk individuals before emergence of clinical disease would permit early intervention that could decrease this mortality. Our previous studies have shown that cells with trisomy 7 can be detected in bronchial epithelium from cancer-free smokers and former uranium miners. However, the use of more than one molecular marker could increase the chance of identifying at-risk individuals. Trisomy 20, which is found in 43-57% of non-small cell lung cancers, is a candidate marker. The purpose of the current investigation was to determine the percentage of cells with trisomy 20 in persons with a high risk for lung cancer. Bronchial epithelial cells that had been assayed for trisomy 7 were assayed for trisomy 20 by fluorescence in situ hybridization. Trisomy 20 was detected in bronchial epithelial cells from lung cancer patients and from smokers and ex-uranium miners without lung cancer. In some cases, patients who were negative for trisomy 7 exhibited trisomy 20. Consequently, more people with field cancerization were identified using both markers. However, the two markers combined did not appear to stratify the risk for lung cancer.

Structured clinical observations: a method to teach clinical skills with limited time and financial resources.

OBJECTIVE: To develop and implement a methodology to teach clinical skills to medical students in busy clinical settings. METHODS: The Structured Clinical Observation (SCO) program with guidelines and observation sheets for history-taking, physical examination, and information-giving skills was created. Faculty development preceded SCO implementation for pediatric clerkship students at Jefferson Children's Health Center. SCO observation sheets were tabulated and faculty and student questionnaires were administered. RESULTS: The mean number of observations per student was 6, with 368 observations done for 63 students. SCOs were highly rated as an educational tool by faculty and students. The impact of the SCO program on faculty ability to perform clinical duties was initially minimal, but increased over the year. Observations were used primarily for feedback, but did influence outpatient clinical faculty's evaluation of two thirds of the students. Only 50% of students reported being observed in other rotations. CONCLUSIONS: SCOs are a feasible, inexpensive, qualitatively effective method of teaching clinical skills. The quantitative effect of SCOs on performance needs to be evaluated.

Confirmation of confocal microscopy diagnosis of Acanthamoeba keratitis using polymerase chain reaction analysis.

BACKGROUND: Acanthamoeba keratitis has commonly been identified with in vivo confocal microscopy and confirmed with histologic examination of an epithelial biopsy specimen. OBJECTIVE: To determine if Acanthamoeba keratitis can be verified using polymerase chain reaction (PCR) of epithelial biopsy specimens. METHODS: Epithelial specimens from patients with suspected Acanthamoeba keratitis by confocal microscopy were tested for Acanthamoeba with PCR of Acanthamoeba ribosomal DNA. RESULTS: Twenty-four of 31 patients with evidence of Acanthamoeba keratitis were positive for Acanthamoeba on PCR analysis using 3 sets of primers. In 22 cases, the sequence obtained closely matched Acanthamoeba castellanii. CONCLUSIONS: This study demonstrates that PCR analysis of epithelial biopsy specimens can provide definitive verification of the confocal microscopic and histologic identification of Acanthamoeba organisms associated with keratitis. Acanthamoeba keratitis is probably quite common, especially in contact lens wearers, although more than half of the patients in this study did not wear contact lenses.

A pediatric clinical skills assessment using children as standardized patients.

OBJECTIVES: To develop and implement a pediatric clinical skills assessment (PCSA) for residents, using children as standardized patients (SPs); to assess the psychometric adequacy of the PCSA and use it to evaluate the performance of residents; and to evaluate the feasibility of using child SPs and the response of the residents and the child SPs to participation in the PCSA. METHODS: Ten 22-minute complete patient encounters were developed, 7 with child SPs. Fifty-six residents (10 second-year pediatric residents, 29 first-year pediatric residents, and 17 first-year family practice residents) were evaluated on the following clinical skills: history taking, physical examination, interpersonal skills, and documentation and interpretation of clinical data/patient note. MAIN OUTCOME MEASURES: Patient encounter checklists, focus groups, and questionnaires. RESULTS: Average skill scores for the 56 residents were 68% (SD, 12%) for history taking, 56% (SD, 26%) for physical examination, 46% (SD, 12%) for patient note, and 68% (SD, 16%) for interpersonal skills. Second-year pediatric residents scored significantly higher on history taking than first-year pediatric and first-year family practice residents; first-year pediatric residents scored significantly higher on interpersonal skills than second-year pediatric and first-year family practice residents; and first- and second-year pediatric residents scored significantly higher on the patient note component than first-year family practice residents. All differences noted were significant at P<.05. There were no significant differences on physical examination between the groups. Reliabilities were 0.69 for history taking, 0.64 for physical examination, 0.76 for interpersonal skills, and 0.81 for the patient note component. On a Likert scale (5 indicates high; 1, low), residents rated the PCSA 3.9 for realism, 4.1 for challenge, 3.1 for enjoyment, and 2.9 for fairness. Child SPs found the experience positive. No negative effects on the children were identified by their real parents or their SP parents. CONCLUSIONS: Our development method gives content validity to our PCSA, and resident scores give indication of PCSA construct validity. Reliabilities are in the acceptable range. Residents found the PCSA challenging and realistic but less than enjoyable and fair. Use of child SPs is feasible. Resident performance scores were low relative to the performance criteria of the PCSA development group. The adequacy of clinical skills teaching and assessment in residency programs needs to be reviewed. Deficits in specific skills and overall performance of residents identified by a PCSA could be used to guide individual remediation and curricular change.

Determination of ammonia in ethylene using ion mobility spectrometry.

A simple procedure to analyze ammonia in ethylene by ion mobility spectrometry is described. The spectrometer is operated with a silane polymer membrane., 63Ni ion source, H+ (H2O)n reactant ion, and nitrogen drift and source gas. Ethylene containing parts per billion (ppb) (v/v) concentrations of ammonia is pulled across the membrane and diffuses into the spectrometer. Preconcentration or preseparation is unnecessary, because the ethylene in the spectrometer has no noticeable effect on the analytical results. Ethylene does not polymerize in the radioactive source. Ethylene's flammability is negated by the nitrogen inside the spectrometer. Response to ammonia concentrations between 200 ppb and 1.5 ppm is near linear, and a detection limit of 25 ppb is calculated.

Protein tyrosine kinase activation by polycyclic aromatic hydrocarbons in human HPB-ALL T cells.

It has been well established that certain polycyclic aromatic hydrocarbons (PAHs), such as 7,12-dimethylbenz[a]anthracene (DMBA), 3-methylcholanthrene (3MC), and benzo[a]pyrene (BaP), produce immunotoxicity and cancer in rodents and that these effects are also likely seen in humans. Our laboratory has found that polycyclic aromatic hydrocarbons (PAHs) produce an increase in intracellular Ca2+ in lymphocytes that appears to correlate with their immunotoxicity. Specifically, immunotoxic PAHs, such as DMBA and BaP, have been shown to produce a sustained increase in intracellular Ca2+ in lymphocytes, whereas nonimmunosuppressive PAHs, such as benzo[e]pyrene (BeP) and anthracene, do not. Our studies previously demonstrated that the rapid increase in intracellular Ca2+ produced by DMBA in HPB-ALL T cells was caused by protein tyrosine kinase (PTK) activation in human T cells, leading to tyrosine phosphorylation of phospholipase C (PLCgamma) and IP3-dependent Ca2+ mobilization. However, the specificity of PTK activation by PAHs was not established. In the present studies, we extend our observations of PTK activation by examining a number of PAHs for their effects on total and specific (Fyn and ZAP-70) PTK activity. We show that 10 microM concentrations of PAHs nonspecifically and rapidly (within 5 min) stimulate PTKs in the HPB-ALL human T cell line. BeP and anthracene were found to be nearly as effective at increasing total tyrosine kinase activity as DMBA, 3MC, and BaP, observed 5 min after exposure. We found that only immunotoxic PAHs activated the Fyn and ZAP-70 PTKs at 10 min, but total PTK activity was still increased by nonimmunotoxic PAHs, BeP, or anthracene after 10 min of exposure. These studies demonstrate that immunotoxic PAHs increase total and specific PTK activity in the human HPB-ALL T cell line. Thus the rapid increase in PTK activity produced by PAHs may not correlate with the immunotoxicity of these agents.

Denaturation of myofibrillar proteins from chickens as affected by pH, temperature, and adenosine triphosphate concentration.

The susceptibility to denaturation of myofibrillar protein from chicken muscles was investigated and compared with denaturation of myofibrillar protein from pork. Immediately postmortem, the Pectoralis profundus (white muscle) and the Pubo-ishio femorale (red muscle) of six Arbor Acres chickens were collected. The Semimembranosus (white muscle) and Psoas major (red muscle) of three Yorkshire x Landrace and three Yorkshire x Landrace x Duroc pigs were collected at 45 min postmortem. Protein denaturation was prevented by keeping the muscles at 0 to 2 C in a buffer (pH 7.2) containing ethylene glycol-bis (beta-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA) (to sequester Ca ions). After purification, myofibrils were incubated at 25 or 40 C, pH 5.4 or 6.5, with 0, 0.68, or 3.4 mM adenosine triphosphate (ATP). Protein solubility, an indicator of denaturation, was assessed after 0, 10, 20, and 60 min incubation. Protein solubility of chicken pectoralis myofibrils was not affected by any of the conditions. In the other myofibrils, pH 5.4 caused significantly (P < 0.05) more protein denaturation than pH 6.5, and incubation at 40 C resulted in significantly more protein denaturation than incubation at 25 C. The presence of ATP (tested at pH 6.5) affected denaturation; higher ATP concentrations resulted in increased loss of solubility. We concluded that chicken red myofibrillar proteins are equally susceptible to denaturation as are pork red and white myofibrils. Chicken pectoralis (white) muscle fibers are least susceptible to denaturation. The results of this study indicate that factors other than protein denaturation are responsible for the low water-holding capacity of pale, soft, exudative chicken breast muscle.

Spontaneous labyrinthine window rupture.

Spontaneous labyrinthine window rupture has been increasingly recognized in recent years. Seven such case histories and details of subsequent management by tympanotomy and fat graft plugging of the fistulae are reported. The importance of a history of physical stress preceding onset of symptoms is emphasized in the case of certain patients who presented with sudden hearing loss accompanied, in some cases, by tinnitus or vertigo. The first 5 patients were reported in a paper presented in October 1977 at the First South African National Otorhinological Congress in Cape Town.

Lump in the throat.

The symptoms of repeatedly swallowing what the patient believes is a postnasal discharge, lump in the throat, and constantly having to clear the throat are commonly encountered in patients who do not show any evidence of sinusitis or organic lesions in the upper gastro-intestinal tract or larynx. It is suggested that incompetence of the lower oesophageal sphincter could lead to the creation of this situation by lowering the pH in the oesophagus and initiating inco-ordinate peristaltic movement. A trial of treatment of 54 patients, selected on a nonrandomized consecutive basis and presenting with the above symptoms, was undertaken, treatment being aimed at increasing the cholinergic activity of the oesophageal smooth muscle and neutralizing acidity. Metoclopramide (Maxolon, Primperan) was the cholinergic agent and polymethylsiloxane aluminium hydroxide (Asilone) was the antacid selected. Results based on symptomatic improvement showed that of 44 patients who reported for the follow-up examination, 35 (83%) had good symptomatic improvement, and 7 (16%) were unchanged. The action of metoclopramide is discussed and some of the literature reviewed. Favourable symptomatic improvement suggests that further trials using this substance, together with a placebo, on a cross-over randomized basis would be worth while. The 'lump in the throat' syndrome can be recognized by the symptom tetrad of: (i) lump in the throat; (ii) repetitive swallowing; (iii) clearing of the throat; and (iv) indigestion.

Some immunological investigations on antithrombin III 'Budapest'.

Immunoelectrophoretic studies were carried out on plasma from a patient with an abnormal antithrombin III molecule (antithrombin III 'Budapest'). One-dimensional immunoelectrophoresis using a commercial antibody to antithrombin III (antibody to alpha2-AtIII) showed two precipitin peaks of alpha2-AtIII antigen. Two-dimensional immunoelectrophoresis showed two precipitin peaks, one with normal electrophoretic mobility, the other with increased electrophoretic mobility. It was shown that alpha2-AtIII antigen with normal mobility was identical to normal alpha2-AtIII, and that the alpha2-AtIII antigen with increased electrophoretic mobility was antigenically deficient, and appeared to be present in higher concentration than the normal alpha2-AtIII antigen. Although one-dimensional immunoelectrophoresis on plasma from the patient's son showed only one peak, two-dimensional immunoelectrophoresis revealed that the son also had two populations of alpha2-AtIII, one with normal mobility, the other with increased mobility. However, the alpha2-AtIII antigen with normal mobility appeared to be present in higher concentration than the alpha2-AtIII antigen with increased mobility. One- and two-dimensional immunoelectrophoresis using a different commercial antibody to alpha2-AtIII showed only one precipitin peak using the patient's plasma. The precipitin peak observed following two-deminsional immunoelectrophoresis was asymmetric and showed increased mobility.

Survey of industrial noise in Port Elizabeth.

The amendment to the Factories, Machinery and Building Work Act of 1941 in regard to hearing conservation is outlined. A survey by the Port Elizabeth Deaf Association on workmen from Cadbury (Pty) Ltd was undertaken in 1973 and on a second group in 1974 and the results are published and discussed. Although the numbers of workmen were small, the results suggest that widespread testing will unearth many cases of unsuspected hearing loss. The implications as applied to industry at large are discussed and the difficulties in adequately assessing large numbers of workmen with adequately trained audiometric testers are stressed. A suggestion is made that mobile clinics under the control of Chambers of Industries would be the most efficient way of approaching the screening problem, and an estimated cost structure in the setting up of such a clinic is introduced.

A new assay for the measurement of total progressive antithrombin.

A new rapid method for assaying total antithrombin activity has been developed based on the inactivation of thrombin incorporated into an agarose gel, during the radial diffusion of plasma in the gel. The area of thrombin inactivation is subsequently observed by the coagulation of fibrinogen in a separate agarose gel layer poured over the thrombin gel. The method is described in detail and its accuracy assessed with respect to other antithrombin assays. Using specific antisera to alpha2-globulin (antithrombin III), alpha2-macroglobin and alpha1-antitrypsin, total antithrombin activity measured by this assay consisted of 47% alpha2-globulin, 29% alpha2-macroglobulin and 26% alpha1-antitrypsin.

A five year experience of the use of factor IX type DE(I) concentrate for the treatment of Christmas disease of Oxford.

A survey is presented of the use of the Oxford type DE(I) II-IX-X concentrate in the treatment of Christmas disease in Oxford from January 1970 to September 1974. 72 different patients were treated with a total of 2436 bottles of this concentrate from 143 different batches (each bottle containing 800-1000 units of factor IX). Although most doses were given for the treatment of minor haemorrhages into joints and muscles, 717 bottles of concentrate were used to treat 11 patients who underwent 14 major surgical operations. No episode of intravascular clotting or pulmonary embolism was seen in any patient receiving the concentrate. A detailed study of the plasma levels of factor V, VIII, total progressive antithrombin, platelets and fibrinogen degradation products was carried out before and after transfusion of type DE(I) concentrate in 14 patients. No significant alteration in those factors was found after the transfusion.

Differential sensitivity of human, avian, and equine influenza A viruses to a glycoprotein inhibitor of infection: selection of receptor specific variants.

Human and animal (avian and equine) influenza A virus isolates of the H3 serotype exhibit marked differences in their ability to bind specific sialyloligosaccharide sequences that serve as cell surface receptor determinants (G. Rogers and J. Paulson, 1983, Virology 127, 361-373). Whereas human isolates of this subtype strongly agglutinate enzymatically modified human erythrocytes containing the terminal SA alpha 2,6Gal sequence, avian and equine isolates preferentially agglutinate erythrocytes bearing the SA alpha 2, 3Gal sequence. As shown in this report, a glycoprotein found in horse serum, alpha 2-macroglobulin, is a potent inhibitor of viral adsorption to the cell surface for human H3 isolates. In contrast, avian and equine isolates are poorly inhibited suggesting a correlation between receptor specificity and inhibitor sensitivity. Growth of a human H3 isolate (A/Memphis/102/72) on MDCK cells in the presence of horse serum resulted in an overall shift in the virus receptor specificity from preferential binding of the SA alpha 2,6Gal linkage to preferential binding of the SA alpha 2,3Gal linkage characteristic of avian and equine isolates. Clonally isolated variants of A/Memphis/102/72 grown in the presence or absence of horse serum exhibited binding properties that account for those observed in the field isolates. Clones which preferentially bound the SA alpha 2,6Gal linkage, like the parent human virus, were very sensitive to inhibition of hemagglutination by horse serum and equine alpha 2-macroglobulin. In contrast, receptor variants which preferentially bound the SA alpha 2,3Gal linkage, like the avian and equine isolate, were insensitive to such inhibitors. None of the variants was very sensitive to inhibition of hemagglutination by human alpha 2-macroglobulin. These results suggest that the presence, in vivo, of a glycoprotein inhibitor such as equine alpha 2-macroglobulin could suppress infection of influenza viruses bearing an H3 hemagglutinin with a SA alpha 2,6Gal specific, inhibitor sensitive phenotype, allowing growth to predominance of a virus which is SA alpha 2,3Gal specific and inhibitor insensitive as found in avian and equine isolates.

A randomized study of factor VIII or prothrombin complex concentrate infusions in children with haemophilia and antibodies to factor VIII.

In four children with haemophilia A and antibodies to factor VIII, 18 bleeding episodes were randomized for treatment with factor VIII concentrate (30 units/kg) and 18 for treatment with a prothrombin-complex concentrate (prothrombinex) given in a dose of 30 units of factor IX/kg. Treatment with prothrombinex was associated with a better clinical response, a significantly greater shortening of the kaolin partial thromboplastin time and significantly lower incidence of post-infusion increase of levels of factor VIII antibodies. Although treatment with factor VIII concentrate was clinically successful in 15 episodes, treatment failures occurred in three instances leading to parental request for withdrawal from study in two families.

Documenting and comparing medical students' clinical experiences.

CONTEXT: The decentralization of clinical teaching networks over the past decade calls for a systematic way to record the case-mix of patients, the severity of diseases, and the diagnostic procedures that medical students encounter in clinical clerkships. OBJECTIVE: To demonstrate a system that documents medical students' clinical experiences across clerkships. DESIGN AND SETTINGS: Evaluation of a method for recording student-patient clinical encounters using a pocket-sized computer-read patient encounter card at a US university hospital and its 16 teaching affiliates during academic years 1997-1998 through 1999-2000. PARTICIPANTS: A total of 647 third-year medical students who completed patient encounter cards in 3 clerkships: family medicine, pediatrics, and internal medicine. MAIN OUTCOME MEASURES: Number of patient encounters, principal and secondary diagnoses, severity of diseases, and diagnostic procedures as recorded on patient encounter cards; concordance of patient encounter card data with medical records. RESULTS: Students completed 86 011 patient encounter cards: 48 367 cards by 582 students in family medicine, 22 604 cards by 469 students in pediatrics, and 15 040 cards by 531 students in internal medicine. Significant differences were found in students' case-mix of patients, the level of disease severity, and the number of diagnostic procedures performed across the 3 clerkships. Stability of the findings within each clerkship across 3 academic years and the 77% concordance of students' reports of principal diagnosis with faculty's confirmation of diagnosis support the reliability and validity of the findings. CONCLUSIONS: An instrument that facilitates students' documentation of clinical experiences can provide data on important differences among students' clerkship experiences. Data from this instrument can be used to assess the nature of students' clinical education.