Characterisation of the fluorescence from freshwater, planktonic bacteria

Amino acid-like fluorescence has been used as an indicator of biological activity in wastewater effluent and in natural waters, and can be detected using fluorescence spectroscopy. Little or no work has been able to state conclusively that these so called 'amino acid-like' fluorophores are associated with proteins present as a result of bacterial activity. This work aims to ascertain whether bacteria are one possible cause of these 'amino acid-like' peaks observed in natural waters. In addition, fluorescence derived solely from one bacterial source was determined as a function of the growth time and temperature. The bacterium Pseudomonas aeruginosa was isolated from the urban River Tame, Birmingham, UK, and planktonic bacteria were grown in sterile, sealed glass jars, in 100 ml growth media. Bacteria were grown at 11, 25 and 37 degrees C, over a maximum of 10 days. A 3D Excitation-Emission Matrix (EEM) plot was generated from fluorescence analysis of the samples. Both tryptophan and tyrosine-like fluorescence, resembling that observed in natural and waste waters, was observed in these samples, indicating that observed fluorescence signals from aquatic systems in the literature were of biotic origin. Significant differences in fluorescence signals were obtained from planktonic cells grown at different temperatures. At 25 and 37 degrees C, cells were found to produce predominantly tryptophan-like fluorescence, with some tyrosine-like fluorescence also detected. A further unknown fluorophore was also detected (emission wavelength of approximately 460 nm, with three excitation centres at 225, 260 and 390 nm), likely to be a bacterially produced metabolite. At 11 degrees C, a more environmentally realistic temperature in temperate environments, quantitative and qualitative differences were observed in fluorescence signals when compared with the higher temperatures, indicating that laboratory observations conducted at higher temperatures may not be easily used to interpret environmental processes.

Management of patients with Streptococcus milleri brain abscesses

OBJECTIVES

We evaluated the efficacy of cefotaxime in the management of brain abscesses caused by Streptococcus milleri. Twenty two patients with a S. milleri brain abscess were treated with metronidazole and cefotaxime, in accordance with recent recommendations by the British Society Of Antimicrobial Chemotherapy (BSAC). Seven patients who had Glasgow Coma Scales < or =11 also received rifampicin and high dose cefotaxime. The clinical response of the patients was determined.

METHOD

A retrospective study at the Queen Elizabeth Hospital, Birmingham covering the period April 1996-March 2004 was carried out. Neurosurgical and anti-microbial therapeutic approaches were reviewed. Any evidence of improvement of clinical features and radiological disappearance of brain abscesses were determined.

RESULTS

Outcome was assessed using the Glasgow Outcome Score (GOS) at 3 and 6 months from the time of surgical intervention. Eighteen patients (82%) had a good outcome by 6 months, with an outcome score of 4-5. Thirteen patients resumed normal life despite minor deficits (GOS 5), while a further five patients had moderate disability though remained independent (GOS 4). One patient had a GOS of 3 and there were three deaths (14). The minimum time to radiological resolution of the abscess was within 1 month in six cases (27) These all represented solitary lesions that required a single drainage procedure in conjunction with 4 weeks of intravenous cefotaxime and metronidazole. Ten cases (45%) had resolution within 4 months and a further three cases took at least 6 months from the time of surgery to show radiological clearance.

CONCLUSIONS

This cohort of patients responded favourably to the guidelines recommended by the BSAC. This was confirmed by the Glasgow Outcome Score (GOS 4-5) at 6 months review. Cefotaxime at a higher dose with rifampicin was prescribed for patients presenting with a decreased conscious level (GCS 8-11), subsequent failure of anticipated clinical improvement or clinical deterioration. There was no clinically significant difference in GOS between the two treatment groups. An algorithm for management of brain abscess is presented, based on our clinical experience and review of the literature.

Overland flow delivery of faecal bacteria to a headwater pastoral stream

AIMS

To quantify and derive statistical relationships with which to predict the delivery of faecal bacteria (Escherichia coli) to a pastoral stream, by overland flow.

METHODS AND RESULTS

A large-scale (1050 m2) rainfall simulator, located upon a steep (18 degrees) grazed hillside in New Zealand, was used to simulate 11 heavy rainfall events. Overland flow was generated and sampled throughout each event, before discharging to a headwater stream. The samples were subsequently analysed to determine the concentration of E. coli. Statistical analysis showed that the time elapsed since the last period of grazing was a statistically significant predictor of both the total number (load) and concentrations of E. coli in overland flow. Between 10(5) and 10(8)E. coli per m2 of hillside were delivered to the stream within overland flow during each event, and peak concentrations ranged between 10(3) and 10(7) most probable number per 100 ml.

CONCLUSIONS

Under heavy rainfall on steep pastoral land, overland flow can transport substantial levels of faecal bacteria to streams. Under such conditions, it is unlikely that vegetated buffer strips will be particularly effective at attenuating bacteria within overland flow.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work has improved understanding of the importance of overland flow as a process contributing to the contamination of pastoral streams by faecal bacteria. In addition, the predictive relationships derived can be incorporated within catchment models.

Malignant autonomic dysreflexia in spinal cord injured men

STUDY DESIGN

Case reports.

OBJECTIVES

To present a series of cases of protracted and severe autonomic dysreflexia (AD) in men with spinal cord injury (SCI), who sustained damage to their descending autonomic pathways.

SETTINGS

GF Strong Rehabilitation Centre, Sexual Health Rehabilitation Service, Vancouver Sperm Retrieval Clinic, Vancouver Coastal Health Authority, Vancouver, BC, Canada.

CASE REPORT

AD is a serious complication of SCI triggered by a variety of noxious or non-noxious stimuli below the level of injury. However, we are presenting three cases of protracted, severe AD we have termed 'malignant', owing to the tendency of progressive worsening not usually seen with AD once the alleviating factor is removed. In all three individuals, AD was initially triggered by ejaculation and continued for a period of more than 1 week. Systolic blood pressure in these individuals increased above 220 mmHg and required either acute hospitalization or hospital assessment. Two of the individuals with malignant AD had American Spinal Injury Association (ASIA) B and C high cervical injury, respectively, with the third having a high thoracic ASIA A injury. In addition to detailed history and neurological examination, electrophysiological assessment of sympathetic skin responses (SSR) demonstrated a significant disruption of the descending autonomic pathways in these individuals.

CONCLUSIONS

Our findings suggest that in addition to the severe injury of the motor and sensory pathways (assessed by ASIA score), these individuals sustained severe injury to the supraspinal autonomic control. A combination of strong triggers such as ejaculation and bladder or colono-rectal irritation with total loss of descending autonomic control to the spinal sympathetic circuits could therefore contribute to the unusual manifestation of AD.

Interventions for infantile esotropia

BACKGROUND

Various aspects of the clinical management of infantile esotropia (IE) are unclear - mainly, the most effective type of intervention and the age at intervention.

OBJECTIVES

The objective of this review was to assess the effectiveness of various surgical and non-surgical interventions for IE and to determine the significance of age at treatment with respect to outcome.

SEARCH STRATEGY

Trials were identified from the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) in The Cochrane Library (Issue 3 2004), MEDLINE (1966 to July 2004), EMBASE (1980 to August 2004) and LILACS (July 2004). We manually searched the conference proceedings of the European Strabismological Association (ESA) (1975-1997, 1999-2002), International Strabismological Association (ISA) (1994) and American Academy of Paediatric Ophthalmology and Strabismus meeting (AAPOS) (1995-2003). Efforts were made to contact researchers who are active in the field for information about further published or unpublished studies.

SELECTION CRITERIA

Randomised trials comparing any surgical or non-surgical intervention for infantile esotropia.

DATA COLLECTION AND ANALYSIS

Each reviewer independently assessed study abstracts identified from the electronic and manual searches.

MAIN RESULTS

No studies were found that met our selection criteria and therefore none were included for analysis.

AUTHORS' CONCLUSIONS

The main body of literature on interventions for IE are either retrospective studies or prospective cohort studies. It has not been possible through this review to resolve the controversies regarding type of surgery, non-surgical intervention and age of intervention. There is clearly a need for good quality trials to be conducted in these areas to improve the evidence base for the management of IE.

Linking perceptions of neighbourhood to health in Hamilton, Canada

STUDY OBJECTIVE

To investigate the association between perceptions of neighbourhood physical and social characteristics and three health outcomes (self assessed health status, chronic conditions, and emotional distress).

DESIGN

Cross sectional survey data analysed in small neighbourhoods.

SETTING

Hamilton, Ontario, Canada, a medium sized industrial city, located at the western end of Lake Ontario (population at the time of the study about 380 000).

PARTICIPANTS

Random sample of 1504 adults aged 18 years and older residing in four contrasting neighbourhoods.

MAIN RESULTS

Significant differences across the four neighbourhoods are apparent in self assessed health status and emotional distress, but not in chronic conditions. Neighbourhoods with lower SES reported poorer health and more emotional distress. Perceptions of the physical environment dominated social concerns in all neighbourhoods. For all three health outcomes, individual risk factors followed expectations, with measures of poverty, age, and lifestyle all significantly associated with poor health outcomes. Physical environmental problems were positively and significantly associated with poor physical and emotional health. Specifically, people reporting they dislike aspects of their neighbourhood's physical environment are 1.5 times more likely to report chronic health conditions (OR 1.56, 95% CI 1.19 to 2.05), while those reporting physical likes with their neighbourhood are less likely to report fair/poor health (OR 0.50, 95% CI 0.28 to 0.90) or emotional distress (OR 0.45, 95% CI 0.26 to 0.80).

CONCLUSIONS

These results demonstrate the importance of neighbourhood perceptions as a determinant of health, as well as conventional factors such as low income, lifestyle, and age. The dominance of physical environmental concerns may have arisen from the industrial nature of Hamilton, but this result merits further investigation.

Preferences for sexual information resources in patients treated for early-stage prostate cancer with either radical prostatectomy or brachytherapy

OBJECTIVE

To identify the preferences for sexual information resources of patients before and after definitive treatment for early-stage prostate cancer with either radical prostatectomy (RP) or brachytherapy.

PATIENTS AND METHODS

Two hundred patients (mean age 64 years) treated with either RP or brachytherapy were recruited from radiation oncology (100) and urology (100) outpatient clinics. Patients completed a survey questionnaire to identify the types of information used, preferred sources of information, knowledge of treatments for erectile dysfunction (ED), effect of sexual function on the treatment decision, and the International Index of Erectile Function (IIEF) to assess their current level of sexual function.

RESULTS

Urologists were identified as the main source of sexual information. Written information, Internet access and videos were identified as preferred sources of information before and after treatment. The effects of treatment on sexual function had no apparent significant influence on the men's definitive treatment choice. Compared with patients in the brachytherapy group, patients in the RP group reported having significantly higher levels of sexual desire (P < 0.001) after treatment, but otherwise the erectile domains of the groups were remarkably similar. Two-thirds of patients wanted more information on the effects of treatment on sexual function, and on available treatments for ED.

CONCLUSIONS

These results support the need for physicians to offer patients access to information on the effect of treatment for early-stage prostate cancer on erectile function before and after treatment.

Improvement in quality of colorectal cancer pathology reporting with a standardized proforma--a comparative study

BACKGROUND

Histopathological evaluation is a critical component in the management of patients with colorectal cancer (CRC). It is the single most powerful prognostic indicator in CRC and determines if adjuvant chemotherapy is indicated. The aim of this study was to assess if the introduction of a comprehensive standardized pathology proforma improved the quality of histopathology reporting.

METHODS

A standardized pathology proforma, based on the 1996 minimum dataset for colorectal histopathology reporting, was introduced in our pathology department in 1998. Pathology reports for all colonic resection specimens for 1996 (n = 85) and 2000 (n = 86) were identified, retrieved and entered on to database. Comparison was made with the minimum dataset published in the 1996 guidelines for the management of colorectal cancer.

RESULTS

Demographic details were complete in all cases. Clinical data was incomplete in 57 (67%) patients in 1996 and 63 (73%) in 2000 (ns; chi2). There were 24 (28%) (7 Abdomino-perineal resections (APER)) and 40 (47%) (17 APER's) rectal specimens for 1996 and 2000, respectively. The presence or absence of pathological background abnormalities were commented on in 18 (21%) reports in 1996 and 80 (93%) reports in 2000 (P < 0.01; Fishers exact test (Fisher)). Histological differentiation was commented on in 73 (86%) and 86 (100%) in 1996 and 2000, respectively (P < 0.01; Fisher). Dukes' stage was stated in 33 (39%) reports in 1996 and 86 (100%) in 2000 (P < 0.01; Fisher) but Dukes' stage was calculable in 84 (99%) in 1996 and 86 reports (100%) for 2000 (ns; Fisher). The apical node was commented on in 34 (40%) reports in 1996 and 85 (99%) reports in 2000 (P < 0.01; Fisher). The median (IQR) number of nodes assessed in 1996 was 8 (5-12) compared to 12 (8-17) in 2000 (P < 0.001; Mann-Whitney (MW)). Complete resection was mentioned in 74 (87%) reports in 1996 and 86 (100%) in 2000 (P < 0.01; Fisher). Regarding rectal specimens, the circumferential resection margin (CRM) was commented on in 19 of 24 specimens in 1996 and 38 of 40 specimens in 2000 (ns; Fisher). Relationship to the peritoneal reflection was commented on in 1 (1%) rectal specimen in 1996 and 30 (35%) in 2000 (P < 0.001; Fisher).

CONCLUSION

The introduction of a standardized proforma for reporting CRC resection specimens improves the quality of histopathological reporting. This aids decision-making regarding adjuvant chemotherapy or radiotherapy and further surveillance.

The effects of testing in shifts on a clinical in-course computerized exam

PROBLEM

Testing a large medical class over two days with a single-form computer-based test has generated questions related to test security and the influence of unequal test preparation times afforded by the testing method.

METHODS

An analysis of variance (anova) design was used to compare the scores for the two days for each of the three tests. In addition, a within-student match-paired t-test of standard score differences was used to examine the relative standing of students across tests administered on different days.

RESULTS

Both the anova and the match-paired t-test failed to detect a difference between first and second day testing.

CONCLUSION

This research suggests that using a single test form with shift-based computerised assessments, spread over as many as two days, does not seriously compromise the integrity of the results. Since creating multiple unique-item forms is often not possible, shift-based testing with a single test form appears to be a fair method of accommodating a large number of students.

A comparison between midazolam co-induction and propofol predosing for the induction of anaesthesia in the elderly

In a prospective, double-blind, randomised, placebo-controlled trial, we have compared the effects of midazolam co-induction with propofol predosing on the induction dose requirements of propofol in elderly patients. We enrolled 60 patients aged > 70 years, attending for urological surgery. The patients were allocated randomly to one of three groups, to receive either midazolam 0.02 mg.kg(-1), propofol 0.25 mg.kg(-1), or normal saline 2 ml (placebo) 2 min prior to induction of anaesthesia using propofol 1% infusion at 300 ml.h(-1). The propofol dose requirements for induction were recorded for two end-points (loss of verbal contact and insertion of an oropharyngeal airway). Cardiovascular parameters were recorded at 1-min intervals for each patient until induction was complete. The midazolam group showed a significant reduction in propofol dose requirements for induction (p = 0.05) compared to the placebo group. The propofol group did not show a significant dose reduction compared to placebo. There were no demonstrable differences in terms of improved cardiovascular stability between groups. We conclude that propofol predosing does not significantly reduce the induction dose of propofol required in the elderly, and there were no cardiovascular benefits to either midazolam co-induction or propofol predosing in the elderly.

Dissemination of heart health promotion: lessons from the Canadian Heart Health Initiative Ontario Project

Situated in central-eastern Canada, Ontario is the largest province with a population of 11 million. Ontario is considered a fairly rich province at the centre of Canada's manufacturing and financial sectors. Public health services in Ontario are primarily delivered through public health departments, each administered by a local board of health and regulated by provincial legislation and program guidelines. The Canadian Heart Health Initiative Ontario Project (CHHIOP) was a four year project (1994 to 1998) undertaken as part of the dissemination phase of the Canadian Heart Health Initiative (CHHI) (see O'Loughlin et al., p.4). CHHIOP is one component of a long-term process to develop and implement effective heart health programs in Ontario.

Managing pain at the end of life

There are many threats to a calm and peaceful passing, but none more distressing than unrelenting pain. Pain exists not only in the physical realm, but also in the psychological, social and spiritual senses. Discussion of barriers and responsibilities are important to assure that pain is appropriately treated. Effective pain treatment relies on communication among patients, families, and care providers. Nurses are a central force in this communication and must act as leaders and advocates in planning care and relieving pain in dying patients.

The clinical potential of matrix metalloproteinase inhibitors in the rheumatic disorders

Rheumatoid arthritis (RA) and osteoarthritis are chronic diseases that result in cartilage degradation and loss of joint function. Currently available drugs are predominantly directed towards the control of pain and/or the inflammation associated with joint synovitis but they do little to reduce joint destruction. In the future, it will be important to have drugs that prevent the structural damage caused by bone and cartilage breakdown. In this review, we will outline the structure and function of cartilage and the key features of matrix metalloproteinases (MMPs), enzymes involved in joint destruction. We will present evidence for the role of MMPs in RA and osteoarthritis, and describe the potential of synthetic inhibitors to control MMP activity and so prevent joint destruction. MMPs are able to cleave all components of the cartilage matrix. Regulation of MMPs is aberrant in osteoarthritis and RA, and MMPs have been implicated in the collagen breakdown that contributes to joint destruction in these diseases. Synthetic MMP inhibitors have been developed. In animal models of osteoarthritis and/or RA, these agents have shown chondroprotective effects. However, results from clinical trials in RA have been equivocal, with some studies being terminated because of lack of efficacy or safety concerns. Nevertheless, this approach remains promising. Increased understanding of the structure, regulation and function of individual MMPs may lead to more effective strategies, and approaches aimed at multiple steps of the pathogenesis of arthritis may be needed to break the chronic cycle of joint destruction.

UV Raman spectral intensities of E. coli and other bacteria excited at 228.9, 244.0, and 248.2 nm

Resonance Raman spectral intensities per average bacterial cell have been measured quantitatively for Gram-negative Escherichia coli, Citrobacter freundii, and Enterobacter aerogenes, as well as Gram-positive Bacillus subtilis and Staphylococcus epidermidis. Spectra have been obtained from cultures in the lag, log, and stationary growth phases excited in turn by 228.9, 244.0, and 248.2 nm light. Although Raman spectral peak positions (cm(-1)) excited by a given wavelength are very similar for all five bacterial species, the organisms are characterized by significantly different spectral intensity values. Intensity changes are associated with growth phase changes in all of the species as well. A comparison of measured with estimated average intensities has been made for spectra of log-phase E. coli. It is possible to compare measured intensities with intensities estimated for log-phase E. coli on the basis of the knowledge of its known average cellular molecular composition. A significant degree of hypochromism is observed in E. coli nucleic acid spectra. In contrast, strong average hyperchromism characterizes all aromatic amino acid peaks belonging to the same E. coli cells. Results suggest that knowledge of spectral intensity values will enhance significantly the capability to identify bacteria by means of their UV resonance Raman spectra.

Matrix metalloproteinases and TIMPs: properties and implications for the treatment of chronic obstructive pulmonary disease

The matrix metalloproteinases (MMPs) are a unique family of metalloenzymes that, once activated, can destroy connective tissue. The active enzymes are all inhibited by tissue inhibitors of metalloproteinases (TIMPs). The relative amounts of active MMPs and TIMPs are important in determining whether tissues are broken down in disease. Although elastase is often regarded as the target enzyme in chronic obstructive pulmonary disease (COPD), both the neutrophils and macrophages in the lung contain metalloproteinases and both collagen and elastin are degraded in disease. Transgenic studies have shown that when MMP1 is over-expressed, pulmonary emphysema develops in mice, while MMP12 knockout mice do not develop pulmonary emphysema when exposed to cigarette smoke. New drugs that can specifically block active MMPs are now available. These potent inhibitors are effective in vitro and prevent the destruction of tissue in animal models. Future patient trials will test the effectiveness of these compounds in preventing tissue destruction.

Asn to Lys mutations at three sites which are N-glycosylated in the mammalian protein decrease the aggregation of Escherichia coli-derived erythropoietin

Erythropoietin (EPO) derived from Escherichia coli is unstable to elevated temperature and tends to aggregate with time, making it unsuitable for high-resolution structure analysis. The mammalian EPO contains about 40% carbohydrate, which makes this protein more stable and less prone to aggregate than non-glycosylated E.coli-derived EPO, but makes it unsuitable for high-resolution analysis owing to its size and flexibility. In an attempt to decrease the aggregation of E.coli-derived EPO, the three asparagine residues at positions 24, 38 and 83 were mutated to lysine residues. In the native protein, these residues are the sites of N-linked glycosylation, which suggests that they should be located on the surface of the protein and should not be involved in interactions in the hydrophobic protein core. Therefore, the substitution of basic amino acids for these neutral asparagine residues is not expected to affect the protein structure, but should increase the isoelectric point of the protein and its net positive charge, decreasing its tendency to aggregate at or below neutral pH due to electrostatic interactions. No apparent alterations in receptor binding, as determined by both cell-surface receptor competition assay and in vitro receptor dimerization experiments, were observed when these mutations were introduced into the EPO sequence. However, this mutant protein displayed a significant increase in stability to heat treatment and to storage, relative to the wild-type molecule. This resulted in a greater number of observable cross peaks in the mutant EPO in 2D NOESY experiments. However, the mutant was similar to the wild-type in stability when urea was used as a denaturant. This indicates that the introduced mutations resulted in a decrease in aggregation with heating or with prolonged incubation at ambient temperature, without changing the conformational stability or the receptor binding affinity of the mutant protein. This approach of placing charged residues at sites where N-glycosylation occurs in vivo could be applied to other systems as well.

Esculetin inhibits cartilage resorption induced by interleukin 1alpha in combination with oncostatin M

OBJECTIVE

To determine if a new inhibitor, esculetin (EST), can block resorption of cartilage.

METHODS

Interleukin 1alpha (IL1alpha, 0.04-5 ng/ml) and oncostatin M (OSM, 0.4-50 ng/ml) were used to stimulate the release of proteoglycan and collagen from bovine nasal cartilage and human articular cartilage in explant culture. Proteoglycan and collagen loss were assessed by dimethylmethylene blue and hydroxyproline assays, respectively. Collagenase levels were measured by assay of bioactivity and by enzyme linked immunosorbent assay (ELISA). The effects of EST on the expression of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the transformed human chondrocyte cell line T/C28a4 were assessed by northern blot analysis. TIMP-1 protein levels were assayed by ELISA. The effect of EST on the MMP-1 promoter was assessed using a promoter-luciferase construct in transient transfection studies.

RESULTS

EST inhibited proteoglycan and collagen resorption in a dose dependent manner with significant decreases seen at 66 microM and 100 microM EST, respectively. Collagenolytic activity was significantly decreased in bovine nasal cartilage cultures. In human articular cartilage, EST also inhibited IL1alpha + OSM stimulated resorption and decreased MMP-1 levels. TIMP-1 levels were not altered compared with controls. In T/C28a4 chondrocytes the IL1alpha + OSM induced expression of MMP-1, MMP-3, and MMP-13 mRNA was reduced to control levels by 250 microM EST. TIMP-1 mRNA levels were unaffected by EST treatment. All cytokine stimulation of an MMP-1 luciferase-promoter construct was lost in the presence of the inhibitor.

CONCLUSION

EST inhibits degradation of bovine nasal cartilage and human articular cartilage stimulated to resorb with IL1alpha + OSM.

Using chaos theory to understand a community-built occupational therapy practice

SUMMARY Community-built occupational therapy programs interact with a wide range of systems. This interaction does not occur in an orderly manner, but in an unpredictable fashion. The use of chaos theory may help program developers understand actual and potential interactions that may occur. To illustrate the use of chaos theory, a case study is presented.