Environment and development. Sustainability science.
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Developing Countries↗
Biomedical subjects
T O'Riordan
Publications and source records attributed to T O'Riordan.
Phosphorescent porphyrin probes in biosensors and sensitive bioassays.
Platinum(II) and palladium(II) complexes of porphyrins and related tetrapyrrolic pigments emit strong phosphorescence at room temperatures, which is characterized by long lifetimes falling into the sub-millisecond range and long-wave spectral characteristics. These features make the dyes useful as probes for a number of bioanalytical applications, particularly those employing time-resolved fluorescent detection. They can provide high sensitivity and selectivity, together with rather simple instrumental set-up. A number of analytical systems are now under development that are based on the use of phosphorescent porphyrin probes. Experimental results are presented on the following systems: (i) fibre-optic phosphorescence lifetime-based oxygen sensor on the basis of hydrophobic platinum-porphyrins and development of advanced sensing materials and prototype instrumentation; (ii) practical applications of the optical oxygen sensor, including a sensitive immunosensor that employs glucose oxidase labels, a rapid screening method for cell viability in microtitre-plate format, non-destructive measurement of oxygen in packaged foods and reagentless biosensors for metabolites (glucose, lactate); and (iii) the use of water-soluble platinum- and palladium-porphyrins as labels for ultra-sensitive time-resolved phosphorescence immunoassays.
Biological Assay↗
Behavioural and physiological responses of sheep to 16 h transport and a novel environment post-transport.
The effect of a novel lairage environment on the ability of sheep to recover from 16 h of transport was investigated. Sheep were transported from grass paddocks to either novel outside paddocks or inside pens, and housed groups were transported to either familiar or novel inside pens. During transport, sheep from outside paddocks lay down less than those from inside pens. In sheep transported to inside pens, those from outside paddocks spent more time lying and spent less time eating; hay and water intakes during the first 12 h post-transport were lower than those previously kept inside. There was no obvious effect of a novel environment post-transport on blood biochemistry, suggesting that the lower post-transport feed and water intakes in a novel environment did not have a significant effect on the ability of the sheep to recover from the feed and water deprivation associated with transport.
Animals↗
Simultaneous analysis of individual and aggregate responses in psychometric data using multilevel modeling.
Psychometric data on risk perceptions are often collected using the method developed by Slovic, Fischhoff, and Lichtenstein, where an array of risk issues are evaluated with respect to a number of risk characteristics, such as how dreadful, catastrophic or involuntary exposure to each risk is. The analysis of these data has often been carried out at an aggregate level, where mean scores for all respondents are compared between risk issues. However, this approach may conceal important variation between individuals, and individual analyses have also been performed for single risk issues. This paper presents a new methodological approach using a technique called multilevel modelling for analysing individual and aggregated responses simultaneously, to produce unconditional and unbiased results at both individual and aggregate levels of the data. Two examples are given using previously published data sets on risk perceptions collected by the authors, and results between the traditional and new approaches compared. The discussion focuses on the implications of and possibilities provided by the new methodology.
Humans↗
Inhaled antimicrobial therapy.
Although antimicrobial therapy has been administered through the inhaled route for decades, it has always been controversial. There are relatively few accepted indications for this mode of administration. Well-controlled studies of aerosolized antibiotics in cystic fibrosis demonstrate that tobramycin on a cyclical basis may reduce sputum volume, bacterial counts, and improve pulmonary function. Preliminary data indicate that inhaled antibiotic therapy of ventilator-associated tracheobronchitis may reduce sputum volume, but the clinical significance of this finding remains to be determined. Inhaled pentamidine is used for prophylaxis of Pneumocystis carinii in patients with human immunodeficiency virus infection who are intolerant of oral prophylactic agents. Ribavirin has been used for 30 years to treat respiratory syncytial virus. The role, if any, of inhaled antifungal therapy with amphotericin B remains undetermined.
AIDS-Related Opportunistic Infections↗
A quantitative test of the cultural theory of risk perceptions: comparison with the psychometric paradigm.
This paper seeks to compare two frameworks which have been proposed to explain risk perceptions, namely, cultural theory and the psychometric paradigm. A structured questionnaire which incorporated elements from both approaches was administered to 129 residents of Norwich, England. The qualitative risk characteristics generated by the psychometric paradigm explained a far greater proportion of the variance in risk perceptions than cultural biases, though it should be borne in mind that the qualitative characteristics refer directly to risks whereas cultural biases are much more distant variables. Correlations between cultural biases and risk perceptions were very low, but the key point was that each cultural bias was associated with concern about distinct types of risks and that the pattern of responses was compatible with that predicted by cultural theory. The cultural approach also provided indicators for underlying beliefs regarding trust and the environment; beliefs which were consistent within each world view but divergent between them. An important drawback, however, was that the psychometric questionnaire could only allocate 32% of the respondents unequivocally to one of the four cultural types. The rest of the sample expressed several cultural biases simultaneously, or none at all. Cultural biases are therefore probably best interpreted as four extreme world views, and a mixture of qualitative and quantitative research methodologies would generate better insights into who might defend these views in what circumstances, whether there are only four mutually exclusive world views or not, and how these views are related to patterns of social solidarity, and judgments on institutional trust.
Culture↗
Exploring the "psychometric paradigm": comparisons between aggregate and individual analyses.
The "psychometric paradigm" developed by Slovic, Fischhoff, and Lichtenstein was a landmark in research about public attitudes toward risks. One problem with work, however, was that (at least initially) it did not attempt to distinguish between individuals or groups of people, except "experts" vs. "lay people." This paradigm produced a "cognitive map" of hazards, and the assumption seemed to be that the characteristics identified were inherent attributes of risk. This paper examines the validity of this assumption. A questionnaire survey similar to those designed by Slovic et al. was conducted, but the data were analyzed at both the aggregate level, using mean scores, and at the level of individuals (N = 131 Norwich residents). The results reported here demonstrate that (1) individuals vary in their perception of the same risk issue; (2) individuals vary in their rating of the same risks characteristics on the same risk issue; and (3) some of the strong intercorrelations observed between risk characteristics at the aggregate level are not supported when the same data are analysed at the level of individuals. Despite these findings, the relationship between risk characteristics and risk perceptions inferred by the psychometric paradigm did hold true at the level of individuals, for most--but not all--of the characteristics. In particular, the relationship between "lack of knowledge to those exposed" and risk perceptions appears to be a complex one, a finding which has important implications for risk communication strategies.
Communication↗
Tracheal aspirates in long-term mechanically ventilated patients. A human model of gram-negative infection and airway inflammation.
It is well known that patients requiring long-term mechanical ventilation and tracheostomy have nearly universal airway colonization with Gram-negative organisms. However, useful parameters to objectively describe the airway inflammation associated with airway instrumentation and colonization have not been well define. In our respiratory care unit, patients who are medically stable except for ventilator dependence are readily available for longitudinal assessment of airway secretions and therefore provide a unique population for studying airway inflammation and infection. To quantitate production of respiratory secretions, we instituted a uniform protocol of suctioning over a 6-h period. Further, we devised a method of dilution and homogenization of tracheal aspirates that permits reproducible intrasample total cell counts (coefficient of variation, 4.6%). With these techniques, patients were then studied serially over a 4- to 7-week period. Total cell count, inflammatory cell differential, and two indices of airway inflammation, human neutrophil elastase (HLE) and soluble-intercellular adhesion molecule-1 (sICAM-1) studied in the sol phase of secretions were monitored. The mean total cell count was 42.2 x 10(6) cells per gram of secretions when patients were clinically stable and not receiving antibiotics. The average differential was neutrophils 69.9%, macrophages 26.9%, and lymphocytes 2.8%. Mean active HLE was 35.6 micrograms/mL and mean sICAM-1 was 83 ng/mL. Six patients during the period of observation received intravenous oral or aerosolized antibiotics for tracheobronchitis. A threefold drop in volume of secretions was measured (p < 0.018). The total cell count and percent neutrophils decreased from 76.4 x 10(6)/g of sputum to 54.9 x 10(6) and 72.2 to 54.9%, respectively. While these changes were not statistically significant, the absolute number of airway neutrophils over the 6 h decreased sevenfold (p < 0.014). Similarly sICAM-1 burden (micrograms per 6-h period) also decreased significantly (p < 0.034). These patients provide a unique human model for future studies specifically designed to assess the effect of novel modalities of anti-inflammatory and antimicrobial agents on respiratory secretions.
Adult↗
Hyperamylasemia associated with progression of a serous surface papillary carcinoma.
A 60-year-old white woman had a bilateral salpingo-oophorectomy, hysterectomy, and omentectomy for serous surface papillary carcinoma. Combination chemotherapy consisting of cisplatin, doxorubicin, and cyclophosphamide was given for 1 year, but was followed by relapse 4 months after completion. This relapse was associated with hyperamylasemia ranging from 2400 IU/liter in the early phase of relapse to 5800 IU/liter in the preterminal phase. While hyperamylasemia has been previously described in serous ovarian cystadenocarcinoma, to our knowledge this is the first report in a patient with serous surface papillary carcinoma. This marker may help in distinguishing the latter from malignant mesothelioma of the peritoneum since this is often an extremely difficult differential diagnosis.
Amylases↗
Progressive multifocal leukoencephalopathy-remission with cytarabine.
A 51-year-old woman who was in complete remission from non-Hodgkin's lymphoma, developed a rapidly progressive dementia. Progressive multifocal leukoencephalopathy (PML) was diagnosed on the basis of a rising antibody titre to JC polyomavirus in cerebro-spinal fluid and serum and the presence of diffuse white matter changes on magnetic resonance imaging. She was treated initially with intravenous cytarabine and showed minimal improvement. Rapid improvement occurred when intrathecal cytarabine was added and the patient is in complete remission from both lymphoma and PML 20 months later.
Cytarabine↗
Adjuvant antibiotic therapy in duodenal ulcers treated with colloidal bismuth subcitrate.
Persistence of Helicobacter pylori after duodenal ulcer healing is associated with high rates of ulcer relapse. We compared colloidal bismuth subcitrate alone with CBS combined with one of four antibiotic regimens in the treatment of duodenal ulcers. Endoscopy and antral biopsies were performed before treatment and four weeks afterwards. Biopsy specimens were examined for histological evidence of gastritis and by Gram stain and culture for H pylori infection. Altogether 141 patients were allocated to one of five treatment groups. Giving CBS and metronidazole (400 mg tid for 7 days) with and without amoxycillin (500 mg tid) achieved higher clearance rates of H pylori than treatment with CBS alone (p less than 0.01). These two combinations also achieved higher rates of antral gastritis healing than CBS alone (p less than 0.01 and p less than 0.05 respectively). Susceptibility to metronidazole was tested in 29 isolates before and in seven isolates after treatment with metronidazole by disc diffusion test and minimum inhibitory concentration assay. Twenty seven (93%) of the isolates were sensitive before treatment while six of seven (86%) were resistant afterwards. Four of the six resistant strains had acquired resistance during treatment and one of these had acquired metronidazole resistance despite concomitant treatment with amoxycillin, to which it remained sensitive. CBS with adjuvant metronidazole at a dose of 400 mg tid for seven days significantly improves the eradication of H pylori compared with CBS alone. Acquired metronidazole resistance, however, seems to be an important cause of failure to eradicate H pylori.
Amoxicillin↗
Haemolytic uraemic syndrome with shigella.
A 49-year-old male developed bloody diarrhoea whilst on a visit to India. Sigmoidoscopy and rectal biopsy showed acute colitis. Shigella dysentery type I was isolated from stool culture. Cytotoxin production by the organism was demonstrated. The patient developed acute renal failure, thrombocytopaenia and microangiopathic haemolytic anaemia. He required mechanical ventilation, haemodialysis, blood transfusion and antibiotic therapy and achieved a complete recovery. This is an unusual case of haemolytic uraemic syndrome complicating shigellosis in an adult.
Cefuroxime↗
The use of depression rating scales.
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Aged↗
Criteria of case definition in Crohn's disease and ulcerative colitis.
The diagnosis of inflammatory bowel disease is usually made on a combination of clinical, radiologic, endoscopic, and histologic grounds. In the differential diagnosis, endoscopy and histologic evaluation of biopsy specimens can help to make a specific diagnosis. Site of disease is important in documentation and can determine drug choice and clinical course. Disease activity indices are important to assess a patient objectively, particularly in multicentre studies. There is poor correlation between disease activity indices and macroscopic and histologic findings. The Severity Activity Index for Crohn's disease has both clinical and laboratory variables and is a valuable tool for the definition of Crohn's disease. An ulcerative colitis activity index that correlates significantly with microscopic and macroscopic scores, using both clinical symptoms and laboratory findings, is proposed.
Colitis, Ulcerative↗
Risk factors in inflammatory bowel disease.
A patient with inflammatory bowel disease may have several risk factors, including host defence and familial and environmental factors. Host defence factors include neutrophil and complement abnormalities and increased intestinal permeability. This may explain why elemental diets are effective treatment in Crohn's disease. Food is a major factor affecting the intestinal tract, and the considerable change in dietary habits during this century may explain why Crohn's disease has become more common. There is a geographic difference in the distribution of the disease. This could be due to difference in fish consumption. Fish oil has been shown to be effective in an uncontrolled study in the treatment of ulcerative colitis. This needs to be confirmed by ongoing controlled studies. Very few data have been published on the dietary habits of different countries. There is a need for a uniform dietary assessment that can be applied in a multicentre study. These studies would involve much co-operation but would yield important clues in the aetiology of inflammatory bowel disease.
Animals↗
Rates of sexual partner change among two pastoralist southern Nilotic groups in east Africa.
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Acquired Immunodeficiency Syndrome↗
On weighing gains and investments at the margin of risk regulation.
Analysts have long noted an apparent discrepancy in the level of investment seemingly necessary to meet "acceptable" levels of public safety. At the margin of risk regulation, i.e., where safety determination is judged acceptable, the traditional cost-benefit calculus appears to contribute obvious rationale to the final political decision. Efforts are now being made to introduce a measure of consistency into the application of risk-cost benefit analysis to radiological protection. This paper reviews these efforts from a UK perspective. It also looks at how the issue was treated in a public setting through the Sizewell B Public Inquiry.
Accident Prevention↗