Risk of Aneurysm Rupture (ROAR) study: protocol for a long-term, longitudinal, UK multicentre study of unruptured intracranial aneurysms

INTRODUCTION

Unruptured intracranial aneurysms (UIA) are common in the adult population, but only a relatively small proportion will rupture. It is therefore essential to have accurate estimates of rupture risk to target treatment towards those who stand to benefit and avoid exposing patients to the risks of unnecessary treatment. The best available UIA natural history data are the PHASES study. However, this has never been validated and given the known heterogeneity in the populations, methods and biases of the constituent studies, there is a need to do so. There are also many potential predictors not considered in PHASES that require evaluation, and the estimated rupture risk is largely based on short-term follow-up (mostly 1 year). The aims of this study are to: (1) test the accuracy of PHASES in a UK population, (2) evaluate additional predictors of rupture and (3) assess long-term UIA rupture rates.

METHODS AND ANALYSIS

The Risk of Aneurysm Rupture study is a longitudinal multicentre study that will identify patients with known UIA seen in neurosurgery units. Patients will have baseline demographics and aneurysm characteristics collected by their neurosurgery unit and then a single aggregated national cohort will be linked to databases of hospital admissions and deaths to identify all patients who may have subsequently suffered a subarachnoid haemorrhage. All matched admissions and deaths will be checked against medical records to confirm the diagnosis of aneurysmal subarachnoid haemorrhage. The target sample size is 20 000 patients. The primary outcome will be aneurysm rupture resulting in hospital admission or death. Cox regression models will be built to test each of the study's aims.

ETHICS AND DISSEMINATION

Ethical approval has been given by South Central Hampshire A Research Ethics Committee (21SC0064) and Confidentiality Advisory Group support (21CAG0033) provided under Section 251 of the NHS Act 2006. The results will be disseminated in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN17658526.

Comparison of suspected and confirmed internal EVD-related infections: a prospective multi-centre U.K. observational study

Background

Diagnosis of internal external ventricular drain (EVD)-related infections (iERI) is an area of diagnostic difficulty. Empiric treatment is often initiated on clinical suspicion. There is limited guidance around antimicrobial management of confirmed versus suspected iERI.

Methods

Data on patients requiring EVD insertion were collected from 21 neurosurgical units in the United Kingdom from 2014 to 2015. Confirmed iERI was defined as clinical suspicion of infection with positive cerebrospinal fluid (CSF) culture and/or Gram stain. Cerebrospinal fluid, blood, and clinical parameters and antimicrobial management were compared between the 2 groups. Mortality and Modified Rankin Scores were compared at 30 days post-EVD insertion.

Results

Internal EVD-related infection was suspected after 46 of 495 EVD insertions (9.3%), more common after an emergency insertion. Twenty-six of 46 were confirmed iERIs, mostly due to Staphylococci (16 of 26). When confirmed and suspected infections were compared, there were no differences in CSF white cell counts or glucose concentrations, nor peripheral blood white cell counts or C-reactive protein concentrations. The incidence of fever, meningism, and seizures was also similar, although altered consciousness was more common in people with confirmed iERI. Broad-spectrum antimicrobial usage was prevalent in both groups with no difference in median duration of therapy (10 days [interquartile range {IQR}, 7–24.5] for confirmed cases and 9.5 days [IQR, 5.75–14] for suspected, P = 0.3). Despite comparable baseline characteristics, suspected iERI was associated with lower mortality and better neurological outcomes.

Conclusions

Suspected iERI could represent sterile inflammation or lower bacterial load leading to false-negative cultures. There is a need for improved microbiology diagnostics and biomarkers of bacterial infection to permit accurate discrimination and improve antimicrobial stewardship.

Characterization of initial/early histologic features of proliferative leukoplakia and correlation with malignant transformation: a multicenter study

The aim of this multicenter retrospective study is to characterize the histopathologic features of initial/early biopsies of proliferative leukoplakia (PL; also known as proliferative verrucous leukoplakia), and to analyze the correlation between histopathologic features and malignant transformation (MT). Patients with a clinical diagnosis of PL who have at least one biopsy and one follow-up visit were included in this study. Initial/early biopsy specimens were reviewed. The biopsies were evaluated for the presence of squamous cell carcinoma (SCCa), oral epithelial dysplasia (OED), and atypical verrucous hyperplasia (AVH). Cases that lacked unequivocal features of dysplasia were termed "hyperkeratosis/parakeratosis not reactive (HkNR)". Pearson chi-square test and Wilcoxon test were used for statistical analysis. There were 86 early/initial biopsies from 59 patients; 74.6% were females. Most of the cases had a smooth/homogenous (34.8%) or fissured appearance (32.6%), and only 13.0% had a verrucous appearance. The most common biopsy site was the gingiva/alveolar mucosa (40.8%) and buccal mucosa (25.0%). The most common histologic diagnosis was OED (53.5%) followed by HkNR (31.4%). Of note, two-thirds of HkNR cases showed only hyperkeratosis and epithelial atrophy. A lymphocytic band was seen in 34.8% of OED cases and 29.6% of HkNR cases, mostly associated with epithelial atrophy. Twenty-eight patients (47.5%) developed carcinoma and 28.9% of early/initial biopsy sites underwent MT. The mortality rate was 11.9%. Our findings show that one-third of cases of PL do not show OED with most exhibiting hyperkeratosis and epithelial atrophy, but MT nevertheless occurred at such sites in 3.7% of cases.

A one-generation reproductive toxicity study of the mycotoxin ochratoxin A in Fischer rats

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus and Penicillium molds. Grain-based foods account for most human dietary exposures to OTA. OTA is a teratogen, but its reproductive and developmental effects are poorly understood. A one-generation reproductive toxicity study was conducted with groups of 16 male and 16 female Fischer rats exposed to 0, 0.026, 0.064, 0.16, 0.4 or 1.0 mg OTA/kg in diet. Dams exposed to 1.0 mg OTA/kg diet had statistically significant F1 pup losses between implantation and postnatal day (PND 4). Delays in preputial separation (PPS) and vaginal opening (VO) were indicative of delayed puberty in F1 rats. Mild renal lesions in nursing pups indicated that exposure prior to weaning impacted the kidneys. The developing kidney was more susceptible to OTA than the adult kidney. Significant increases in multi-oocyte follicles (MOFs) and proportional changes in resting and growing follicles were observed in F1 female ovaries. Plasma testosterone was reduced in F0 males, and there were negative effects on sperm quality in F0 and F1 male rats. The results confirm that continuous dietary exposure to OTA causes post-implantation fetotoxicity in dams, and renal and reproductive toxicity in their male and female offspring.

Shunt disconnection is less likely using a surgeon's knot compared with a surgical constrictor knot

INTRODUCTION

Ventriculo-peritoneal shunt malfunction is a common neurosurgical presentation, which may occur as a result of shunt disconnection at the level of the valve. Previous studies assessing ligatures have suggested that the constrictor knot is stronger in securing a ligature compared to the surgeon's knot. Our study compared the ability of each knot to secure shunt tubing to the valve.

METHODS

A medtronic shunt valve was secured to a peritoneal catheter using the surgeon's knot versus constrictor's knot. The weight and subsequent force (N) required to pull off the shunt tubing at the knot site were recorded.

RESULTS

The mean pull-off force was 11.7 N for the surgeon knot, and 8.9 N for the constrictor knot. There was significant difference in favour for the surgeon's knot compared to the constrictor knot.

CONCLUSIONS

The surgeon's knot is significantly stronger than the constrictor knot for securing a peritoneal catheter to a CSF shunt valve.

Paediatric focal intracranial suppurative infection: a UK single-centre retrospective cohort study

Background

Paediatric focal intracranial suppurative infections are uncommon but cause significant mortality and morbidity. There are no uniform guidelines regarding antibiotic treatment. This study reviewed management in a tertiary healthcare centre in the United Kingdom and considers suggestions for empirical treatment.

Methods

A retrospective, single-centre cohort review of 95 children (< 18 years of age) with focal intracranial suppurative infection admitted between January 2001 and June 2016 in Newcastle upon Tyne, United Kingdom. Microbiological profiles and empirical antibiotic regimens were analysed for coverage, administration and duration of use. Mortality and neurological morbidity were reviewed. Data was analysed using t-tests, Mann-Whitney U tests, independent-samples median tests, and χ²-tests where appropriate. P-values < 0.05 were considered statistically significant.

Results

Estimated annual incidence was 8.79 per million. Age was bimodally distributed. Predisposing factors were identified in 90.5%, most commonly sinusitis (42.1%) and meningitis (23.2%). Sinusitis was associated with older children (p < 0.001) and meningitis with younger children (p < 0.001). The classic triad was present in 14.0%.

43.8% of 114 isolates were Streptococcus spp., most commonly Streptococcus milleri group organisms. Twelve patients cultured anaerobes.

Thirty one empirical antibiotic regimens were used, most often a third-generation cephalosporin plus metronidazole and amoxicillin (32.2%). 90.5% would have sufficient cover with a third generation cephalosporin plus metronidazole. 66.3% converted to oral antibiotics. Median total antibiotic treatment duration was 90 days (interquartile range, 60–115.50 days).

Mortality was 3.2, 38.5% had short-term and 24.2% long-term neurological sequelae.

Conclusions

Paediatric focal intracranial suppurative infection has a higher regional incidence than predicted from national estimates and still causes significant mortality and morbidity. We recommend a third-generation cephalosporin plus metronidazole as first-choice empirical treatment. In infants with negative anaerobic cultures metronidazole may be discontinued.

Unusual cranial infection caused by Citrobacter Koseri

A 60-year-old female had a frontal bone intraosseous meningioma resected 10 years previously. On follow up CT head, an enlarging intraosseous frontal bone lesion was noted. This was thought to be a recurrent frontal meningioma. Intraooperatively, she was found to have an abscess deep to the cranioplasty.

Eruptive Milia Within a Tattoo: A Case Report and Review of the Literature

<p>Of the many tattoo reactions the most common are allergic, granulomatous, lichenoid, photosensitive, pseudolymphomatous, and infectious. Eruptive milia are a rare complication with only three prior reports in the English literature. A 19-year-old African American female presented with tiny, white papules confined within the margins of a tattoo. She denied trauma or associated symptoms at the site. Biopsy demonstrated deposits of black granular material within the dermis and a small infundibular cyst; a diagnosis of eruptive milia within tattoo was made. The milia responded to treatment with urea 40% cream and tretinoin 0.1% cream. Given its rarity, it is important to recognize the presentation of this disorder as other tattoo reactions require more aggressive management. While further research is necessary to determine the exact pathogenesis of this condition, the authors propose a mechanism along with a review of the literature to discuss management.</p> <p><em>J Drugs Dermatol. 2017;16(6):621-624.</em></p>.

Prostate dural metastasis presenting as chronic subdural hematoma. A case report and review of the literature

Background:

Malignant disease metastasising to the cranial dura is rare. Dural metastases manifesting as a subdural fluid collection and presenting as a chronic subdural hematoma is an uncommon entity with unknown pathophysiology.

Case Description:

We present a patient with known prostate cancer metastasising to the cranial dura masquerading as a chronic subdural hematoma. The patient presented with bilateral subdural collections manifesting with confusion and dysphasia. Initial drainage of the larger, symptomatic left side improved only temporarily patient's symptoms. A second drainage of the collection was performed on the same side 5 days later and dural biopsies taken during the same procedure revealed prostate metastases. The patient improved slowly and was discharged to a hospice for palliative care management.

Conclusions:

Prostate dural metastases should be suspected in patients with known prostate cancer presenting with a subdural collection in the absence of cranial trauma. If decision to drain the subdural collection is taken, then biopsies can be taken the same time as they can pose a diagnostic challenge.

Factors affecting diagnostic yield in needle biopsy for brain lesions

INTRODUCTION

We analyse the factors that are associated with the diagnostic yield of needle brain biopsy.

MATERIAL AND METHODS

We present a retrospective series of 124 consecutive biopsies in a 30-month period. Patients' demographics (age, gender), lesion topography (side, location, depth), lesion characteristics (histology, volume, radiological enhancement), type of biopsy procedure (freehand, ultrasound guided, frameless and frame-based stereotactic) and the use of intraoperative histologic examination were correlated with the diagnostic rate. Descriptive statistics and a nominal logistic regression model were used to evaluate the factors influencing diagnostic yield.

RESULTS

63 men and 61 women were included in the study with mean age 59.2 (range: 16-86). 55 were frame-based stereotactic biopsies, 33 were frameless stereotactic biopsies, 29 biopsies were performed under ultrasound guidance and 7 freehand. The diagnostic yield in our series is 93.5%. The gender, lesion topography, biopsy method, use of intraoperative histology and enhancement did not correlate with the diagnostic yield. Younger age had a negative impact on diagnostic yield. 6 out of 8 inconclusive biopsies were in non-glial lesions (p < 0.05). The odds of obtaining a positive diagnosis increased sevenfold with every cc increase in lesion volume.

CONCLUSION

The age of the patient, the volume and the histology of the brain lesion had an impact on the diagnostic yield of needle biopsy. None of the other factors significantly influenced the diagnostic rate.

Relation between income inequality and mortality: empirical demonstration

Objective To assess the extent to which observed associations between income inequality and mortality at population level are statistical artifacts. Design Indirect "what if" simulation using observed risks of mortality at individual level as a function of income to construct hypothetical state-level mortality specific for age and sex as if the statistical artifact argument were 100% correct. Method Data from the 1990 census for the 50 US states plus Washington, DC, were used for population distributions by age, sex, state, and income range; data disaggregated by age, sex, and state from the Centers for Disease Control and Prevention were used for mortality; and regressions from the national longitudinal mortality study were used for the individual-level relation between income and risk of mortality. Results Hypothetical mortality, although correlated with inequality (as implied by the logic of the statistical artifact argument), showed a weaker association with the level of income inequality in each state than the observed mortality. Conclusions The observed associations in the United States at the state level between income inequality and mortality cannot be entirely or substantially explained as statistical artifacts of an underlying individual-level relation between income and mortality. There remains an important association between income inequality and mortality at state level above anything that could be accounted for by any statistical artifact. This result reinforces the need to consider a broad range of factors, including the social milieu, as fundamental determinants of health.

Medical education and patients' responsibilities: back to the future?

Medical student learning is dependent on an unwritten agreement between patients and the medical profession, in which students "practise" upon real patients in order that, when they are doctors, those same patients will benefit from the doctors' skills. Given the increasing propensity for patients to refuse to take part in such learning, there is a danger that doctors will qualify without being truly competent. As patients, we must all ask ourselves, when asked to take part in medical teaching: if this student/trainee doesn't learn now, on me and under supervision, how will the person be truly competent next time, when this is for real, and the patient might be me or my loved one? We argue that a new and more explicit agreement is needed, in which the default should be that all patients are willing to help in the education of medical students, while we ensure that all such students are already competent in simulation before first practising upon real patients.

Use of geographic and genotyping tools to characterise tuberculosis transmission in Montreal

SETTING

In Canada, tuberculosis (TB) is increasingly an urban health problem. Montreal is Canada's second-largest city and the second most frequent destination for new immigrants and refugees.

OBJECTIVES

To detect spatial aggregation of cases, areas of excess incidence and local 'hot spots' of transmission in Montreal.

DESIGN

We used residential addresses to geocode active TB cases reported on the Island of Montreal in 1996-2000. After a hot spot analysis suggested two areas of overconcentration, we conducted a spatial scan, with census tracts (population 2500-8000) as the primary unit of analysis and stratification by birthplace. We linked these analyses with genotyping of all available Mycobacterium tuberculosis isolates, using IS6110-RFLP and spoligotyping.

RESULTS

We identified four areas of excess incidence among the foreign-born (incidence rate ratios 1.3-4.1, relative to the entire Island) and one such area among the Canadian-born (incidence rate ratio 2.3). There was partial overlap with the two hot spots. Genotyping indicated ongoing transmission among the foreign-born within the largest high-incidence zone. While this zone overlapped the area of high incidence among Canadian-born, genotyping largely excluded transmission between the two groups.

CONCLUSIONS

In a city with low overall incidence, spatial and molecular analyses highlighted ongoing local transmission.

How to measure dietary intake and food habits in adolescence: the European perspective

AIM

This paper deals with some methodological aspects of data collection in the context of measuring dietary intake in individuals in their adolescence life stage.

METHOD

Experiences from three partners of the HELENA project in dietary intake measurement in children and adolescents are presented in this paper with emphasis on characteristics of under-reporting, long-term diet measurement and food patterns (Dortmund DONALD group), influences of survey duration on under-reporting (Ghent group) and meal habits (Spanish AVENA group).

RESULTS

Under-reporters in the DONALD Study, particularly female adolescents, had a significantly higher body mass index (BMI) than non-under-reporters; BMI could not be explained by different long-term dietary patterns during childhood and adolescence clustered according to fat consumption; consumers of fast food had higher BMI values than nonconsumers. In the Ghent experience, the decline in population mean energy intake as calculated over selected clusters of days is 184 kcal (6.5%) in boys and 116 (5.6%) in girls; the cluster of 1 recording day and the cluster of 3 recording days were not significantly different but they were both significantly different from the 7-day cluster; no significant interaction was observed between the effect of time and BMI. In the AVENA Study, the percentage of adolescents skipping breakfast was higher in females (8.6%) than in males (3.5%, P<0.001); higher BMI values were observed in those skipping breakfast than in those notskipping breakfast, but differences were statistically significant in males at 15 y and in females at 14 and 17 y; adolescents avoiding some food groups for breakfast had higher BMI values (carbohydrates, fruits and pastries in males and milk, fruits and pastries in females).

CONCLUSION

Dietary and nutrient intake data in the HELENA project will be obtained by means of repeated 24-h dietary recalls. Data from HELENA might be a basis for developing complex approaches like Healthy Eating Indices.

Effects of chlorinated solvents on four species of North American amphibians

Tetrachloroethylene (PCE), a dry cleaning and degreasing solvent, can enter groundwater through accidental leaks or spills, and concentrations as high as 75 mg/L have been reported in Canadian aquifers. Amphibians in wetlands receiving contaminated groundwater may be exposed to PCE and its degradation products, but little information is available on the impacts of these compounds on indigenous amphibian species. Acute (96-h static renewal) exposures to PCE and its major degradation products, trichloroethylene (TCE) and cisand trans-dichloroethylene, were conducted on embryos of four North American amphibian species: wood frogs (Rana sylvatica), green frogs (R. clamitans), American toads (Bufo americanus), and spotted salamanders (Ambystoma maculatum). Subsequently, chronic exposures to PCE and TCE were conducted with the larvae of American toads. Both PCE and TCE were teratogenic to amphibian embryos; median effective concentrations (EC50s) for developmental deformities produced by PCE and TCE exposure for wood frogs and green frogs were 12 and 40 mg/L, respectively. Embryonic survivorship, however, was not compromised at these concentrations. American toads were less sensitive; the EC50 for developmental abnormalities was not attained at the highest test concentrations, 45 and 85 mg/L PCE and TCE, respectively. These results are pertinent in assessing the impact of groundwater pollution on an aquifer-fed wetland.

Timing of surgery for supratentorial aneurysmal subarachnoid haemorrhage: report of a prospective study

OBJECTIVES

The debate on the timing of aneurysm surgery after subarachnoid haemorrhage (SAH) pivots on the balance of the temporal risk for fatal rebleeding versus the risk of surgical morbidity when operating early on an acutely injured brain. By following a strict management protocol for SAH, the hypothesis has been tested that in the modern arena of treatment for aneurysmal SAH the timing of surgery to secure supratentorial aneurysms does not affect surgical outcome.

METHODS

Over a 6 year period, patients admitted with a diagnosis of SAH to a regional neurosurgical unit have been prospectively studied. All have been on a management protocol in which early transfer and resuscitation has been followed regardless of age and clinical condition. Angiographic investigation and surgery have been pursued in those who have been able to at least flex to pain. A total of 1168 patients (60.7% female, mean age 54.3) with proved SAH were received on median day 1 (86.4% arrived within 3 days) of the ictus. Of these, 784 (67.1%) showed aneurysms on angiography and were prepared for surgery. Those who received surgery for a supratentorial aneurysm within 21 days of the ictus were included in the final analysis (n=550). Patients with an initial negative angiogram, with posterior circulation aneurysms, or aneurysms treated by endovascular means, with aneurysms requiring emergency surgery for space occupying haematomas, with aneurysms which re-bled before surgery, and those who received very late surgery (after 21 days from ictus) were excluded. Surgical outcomes at hospital discharge and after 6 months were assessed using the Glasgow outcome score (GOS). Discharge destination and duration of stay in a neurosurgical ward were also documented. The influence of the timing of surgery (early group day 1-3 postictus, intermediate group day 4-10, or late group day 11-21) was analysed prospectively.

RESULTS

60.2% of cases fell into the early surgery group, 32.4% into the intermediate group, and 7.5% into the late operated group. Late surgery was due to delays in diagnosis, transfer, and logistic factors, but not clinical decision. The demographic characteristics, site of aneurysm, and clinical condition of the patients at the time of initial medical assessment were balanced in the three surgical timing groups. There was no significant difference in GOS between the surgical timing groups at 6 months (favourable GOS score 4 and 5: 83.2%, 80.5%, and 83.8% respectively; p=0.47, Kruskal-Wallis test). Outcome was favourable in 84% of patients under 65 years, and 70% in those over 65. The discharge destinations (home, referring hospital, nursing home, rehabilitation centre) showed no significant difference between surgical timing groups. There was no significant difference in mean time to discharge after admission to this hospital from the referring hospital (16.2, 16.2, and 14.6 days for early, intermediate, and late groups respectively; p=0.789, Analysis of variance (ANOVA)). As a result, there was reduction in the mean duration of total hospital inpatient stay in favour of the earliest operated patients (mean time 18.1, 22.0, and 28.3 days respectively; p=0.001. ANOVA showed that besides age, the only determinant of surgical outcome and duration of stay was presenting clinical grade (p<0.0005).

CONCLUSION

The current management of patients presenting with SAH from anterior circulation aneurysms allows early surgery to be followed safely regardless of age. The only independent variables affecting outcome are age and clinical grade at presentation. The timing of surgery did not significantly affect surgical outcome, promoting a policy for early surgery that avoids the known risks of rebleeding and reduces inpatient stay.

Community voices: views on the training of future doctors in Birmingham, UK

The United Kingdom (UK) population is diverse with nearly 6% minority ethnic communities. Both patients and doctors experience difficulties when dealing with someone from a different ethnic group. Medical education has failed to keep pace with the changing needs of the diverse population. We report a project in which 12 established (religious/cultural and specific interest) community groups expressed their views on what future doctors should learn about serving diverse populations. Data were obtained by group discussion and through the media using a structured format. Fifteen themes emerged which were grouped under three broad themes: firstly, the identification by group members of their perception of the 'differences' in social and cultural beliefs and behaviours of their individual community; secondly, the identification of characteristics of a culturally sensitive doctor; and lastly, recommendations for changes in medical training. New teaching has been introduced to the medical curriculum that incorporates the themes raised by the communities and which reflects consciousness raising and communication issues.

Characterization of the human Xq21.3/Yp11 homology block and conservation of organization in primates

The Xq21.3/Yp11 homology block on the human sex chromosomes represents a recent addition to the Y chromosome through a transposition event. It is believed that this transfer of material occurred after the divergence of the hominid lineage from other great apes. In this paper we investigate the structure and evolution of the block through fluorescence in situ hybridisation, contig assembly, the polymerase chain reaction, exon trapping, sequence comparison, and annotation of sequence data. The overall structure is well conserved between the human X chromosome and the Y chromosome as well as between the X chromosomes from different primates. Although the sequence data reveal a high level of nucleotide sequence identity for the human X and Y, there are regions of significant divergence, such as that around the marker DXS214. These are presumably the consequence of multiple rearrangements during evolution and are of particular importance with respect to the potential gene content in this segment of the interval.

Assessment of Changes in Biodiversity when a Community of Ultramicrobacteria Isolated from Groundwater Is Stimulated to Form a Biofilm

The stimulation of groundwater bacteria to form biofilms, for the remediation of polluted aquifers, is subjected to environmental regulations that include measurement of effects on microbial biodiversity. Groundwater microorganisms contain a proportion of unidentified and uncharacterized ultramicrobacteria (UMB) that might play a major role in the bioclogging of geological materials. This study aimed to assess the changes in genetic and metabolic biodiversity when a community of UMB, isolated from groundwater, is stimulated to form biofilms on a ceramic surface. UMB were stimulated with aerobic conditions and injection of molasses, in reactors reproducing groundwater composition and temperature. Concentration of planktonic viable UMB, secretion of extracellular polymeric substances (EPS), and biofilm thickness were monitored. The assessment of changes in biodiversity was achieved by comparing the initial UMB community to the biofilm community, using the single strand conformational polymorphism (SSCP) method, the cloning and sequencing of 16S rRNA gene (16S rDNA) sequences, and the Biolog microplate system. The hypothesis stating that indigenous UMB would play a significant role of in the biofilm development was corroborated. Within 13 days of stimulation, the UMB produced 700 mg L?1 of planktonic EPS and formed a biofilm up to a thickness of 1100 mm. This stimulation led to a decrease in genetic diversity and an increase in metabolic diversity. The decrease in genetic diversity was shown by a reduced number of single strand DNA fragments in the SSCP profiles. As such, 16S rDNA sequences from the biofilm revealed the predominance of four bacterial groups: Zoogloea, Bacillus/Paenibacillus, Enterobacteriaceae, and Pseudomonads. A significant increase in metabolic diversity was shown by a highest substrate richness profile and a lower substrate evenness profile of the biofilm bacterial population (p = 0.0 and p = 0.09, respectively). This higher metabolic diversity might be a consequence of the stimulation that seemed to favor the growth of bacteria having a high nutritional versatility. Stimulation of UMB, isolated from groundwater, was effective to form a biofilm having a high metabolic biodiversity. This combination of molecular-based and metabolic-based methods expanded the insight into monitoring the changes in bacterial biodiversity.

Clogging of a limestone fracture by stimulating groundwater microbes

Biological clogging is promoted in aquifers either to contain or to remediate groundwater. In this study, an apparatus able to detect small changes in hydraulic conductivity (K) was developed to measure the clogging of a single fracture in limestone, following microbial stimulation. The fracture had a 2.5 mm2 section and was 50 cm long. Prior to the inoculation of the limestone, the sequencing of representative clones from 16S rRNA genes isolated from groundwater, showed significant affiliation with Cytophaga spp., Arcobacter spp. and Rhizobium spp. These bacteria are known to secrete extracellular polymeric substances and form biofilms. When nutrients were added to the inoculated limestone, a decrease in K occurred after 8 days, reaching 0.8% of its initial value after 22 days (Kfi = 340 cm min-1). This study showed that a stimulation of indigenous microbes from groundwater effectively clogged a macrofracture in limestone, suggesting the potential application of biobarriers in fractured rock aquifers.

Recovering maxillofacial trauma patients: the hidden problems

This longitudinal study highlights the psychological and functional problems that can result from maxillofacial trauma. This is the first study to report outcome at one year. A total of 147 patients admitted for surgery following facial trauma were recruited over a seven-month period. Three questionnaires were used to record patient-derived levels of dysfunction: the Hospital Anxiety Depression scale, a modified University of Washington Quality of Life questionnaire and five non-validated facial trauma items. At one year 46 patients (31%) responded. Although there were significant improvements in scores from pre-operatively to one year, with all patients being discharged from outpatient follow-up, there was a substantial level of subjective symptomatology. Most notable was the level of anxiety and depression, which were present in 30% of the sample at both time points. Health-care professionals tend to underestimate the long-term effects of maxillofacial trauma. To improve patient care, greater appreciation of these problems is required at the time of initial management.

Bilateral vocal cord palsy after ventricular drainage in a child

Vocal cord palsies are caused by high intracranial pressure and normally improve with treatment. Our case report implies that stridor after drainage of a hydrocephalus, in susceptible patients, can be a result of worsening of vocal cord palsies.

Heterotopic bone formation causing recurrent donor site pain following iliac crest bone harvesting

An unusual case of recurrent iliac crest donor site pain secondary to heterotopic bone formation is described. The literature is reviewed with a special emphasis on the aetiology and treatment of this entity.

Relation between income inequality and mortality: empirical demonstration

OBJECTIVE

To assess the extent to which observed associations at population level between income inequality and mortality are statistical artefacts.

DESIGN

Indirect "what if" simulation by using observed risks of mortality at individual level as a function of income to construct hypothetical state level mortality specific for age and sex as if the statistical artefact argument were 100% correct.

SETTING

Data from the 1990 census for the 50 US states plus Washington, DC, were used for population distributions by age, sex, state, and income range; data disaggregated by age, sex, and state from the Centers for Disease Control and Prevention were used for mortality; and regressions from the national longitudinal mortality study were used for the individual level relation between income and risk of mortality.

RESULTS

Hypothetical mortality, while correlated with inequality (as implied by the logic of the statistical artefact argument), showed a weaker association with states' levels of income inequality than the observed mortality.

CONCLUSIONS

The observed associations in the United States at the state level between income inequality and mortality cannot be entirely or substantially explained as statistical artefacts of an underlying individual level relation between income and mortality. There remains an important association between income inequality and mortality at state level over and above anything that could be accounted for by any statistical artefact. This result reinforces the need to consider a broad range of factors, including the social milieu, as fundamental determinants of health.

Folkecology and commons management in the Maya Lowlands

Three groups living off the same rainforest habitat manifest strikingly distinct behaviors, cognitions, and social relationships relative to the forest. Only the area's last native Maya reveal systematic awareness of ecological complexity involving animals, plants, and people and practices clearly favoring forest regeneration. Spanish-speaking immigrants prove closer to native Maya in thought, action, and social networking than do immigrant Maya. There is no overriding "local," "Indian," or "immigrant" relationship to the environment. Results indicate that exclusive concern with rational self-interest and institutional constraints do not sufficiently account for commons behavior and that cultural patterning of cognition and access to relevant information are significant predictors. Unlike traditional accounts of relations between culture, cognition, and behavior, the models offered are not synthetic interpretations of people's thoughts and behaviors but are emergent cultural patterns derived statistically from measurements of individual cognitions and behaviors.

Community-based clinical education at the University of Birmingham Medical School

Throughout the United Kingdom, medical schools have begun to make significant changes in the content and delivery of their undergraduate curricula in response to a number of social and educational forces. In particular, many schools have begun to focus increasingly on community-based education. This and other changes mirror developments that have taken place in other countries and in the context of other health care systems, with such forerunners as Harvard, Maastricht, and McMaster having had a fundamental influence. In this article, the authors describe the forces for curricular change in the United Kingdom and the specific recommendations for change made by the General Medical Council. They then discuss in detail the new curriculum at the University of Birmingham medical school, focusing in particular on a community medicine module, where students spend ten days per academic year learning in general medical practices in and around the city of Birmingham.

Attitudes toward smoking

OBJECTIVES

This article examines socio-demographic variations in attitudes about the health effects of smoking, second-hand smoke, and the importance of smoke-free environments.

DATA SOURCE

The data are from the Health file of the 1996/97 cross-sectional provincial household component of the National Population Health Survey, conducted by Statistics Canada. The sample consists of 60,260 respondents aged 12 or older.

ANALYTICAL TECHNIQUES

Three smoking attitudes scores were derived. Multivariate analyses were used to study how age, sex, educational attainment, province and smoking status were associated with attitude scores.

MAIN RESULTS

Smokers placed less emphasis than non-smokers on the health risks associated with smoking. Older Canadians, particularly smokers aged 65 and older, tended to have more lenient attitudes toward smoking, compared with younger age groups. Respondents with high school education or less held more lenient attitudes, compared with those with a university degree. Quebec residents were more tolerant of tobacco use than were residents of other provinces.

Further characterization of the latency-associated transcription unit of Marek's disease virus

Previous studies have identified a large (L) and a small (S) RNA transcript antisense to the MDV homologue of the ICP4 gene of herpes simplex virus (HSV) in cells infected with Marek's disease virus (MDV) and in lymphoblastoid cell lines. In this study the 5' and 3' ends of the L RNA and of the sense ICP4 transcript of MDV were mapped by Northern hybridization and RNase protection assays. The results showed that L RNA is approximately 10.6 kb and that the ICP4 sense transcript is initiated in the region of genomic DNA where the L RNA terminates whereas L RNA is initiated where the ICP4 transcript terminates. L RNA was abundant in chick embryo fibroblasts (CEF) infected with virus strain HPRS16/attenuated whereas S RNA was predominant in CEF infected with oncogenic HPRS16 and in RPL-1 cell line. Results of cycloheximide experiments showed that the ICP4 gene of MDV was transcribed as an immediate-early gene in infected CEF whereas transcription of the L RNA required protein synthesis. Sequencing of cDNA and Northern hybridization using oligonucleotide probes showed that S RNA shared similar intron/exon boundaries as the cDNAs from several cell lines indicating that there might be a relationship between the S RNA and the antisense transcripts that generated the cDNAs.

Antiangiogenic properties of a novel shark cartilage extract: potential role in the treatment of psoriasis

BACKGROUND

A number of inflammatory and immune diseases are associated with vascular changes. Psoriasis, as an example, is a common inflammatory skin disease with dilation of capillaries as an early histological change. In more developed psoriatic lesions there is proliferation of blood vessels and neovascularization. The use of agents that target these vascular changes represents a novel therapeutic strategy in the treatment of inflammatory diseases. Since cartilage is an avascular tissue, it has been hypothesized that there may be factors found in cartilage that inhibit blood vessel formation.

OBJECTIVE

The objectives of this study were 1) to determine whether extracts of cartilage could inhibit angiogenesis, and 2) since altered angiogenesis is associated with certain diseases, including psoriasis, to examine whether inhibition of angiogenesis could potentially contribute to the treatment of psoriasis.

METHODS

Extracts of shark cartilage were prepared by homogenization and ultrafiltration to derive the active agent termed AE -941. This agent was tested for antiangiogenesis activity using the embryonic vascularization test, which is a modification of the ex vivo chick embryo culture (CAM). Since one of the first steps in angiogenesis is degradation by metalloproteinases of the basement membrane of capillaries, AE -941 was tested for collagenase activity using a fluorogenic peptide substrate. Anti-inflammatory properties were tested using a cutaneous irritation model in humans.

RESULTS

A dose dependent inhibition in embryonic neovascularization as well as in collagenase activity by AE -941 was demonstrated. When test compounds were applied on the forearms of test subjects, AE -941 was shown to have anti-inflammatory properties. Anecdotal data suggested that topical AE -941 had a beneficial effect in psoriasis.

CONCLUSION

Our results show that AE -941 has anti-angiogenic and anti-inflammatory properties. Antiangiogenesis agents such as AE -941 provide an entirely new class of agents to treat cutaneous and systemic diseases associated with altered vascularity.

Marek's disease virus EcoRI-Q gene (meq) and a small RNA antisense to ICP4 are abundantly expressed in CD4+ cells and cells carrying a novel lymphoid marker, AV37, in Marek's disease lymphomas

Mature lymphomas produced in Rhode Island Red (RIR) chickens infected with the RB1B strain of Marek's disease virus (MDV) were examined for the presence of viral DNA and RNA and expression of viral antigens. In situ hybridization showed that all tumours examined contained viral DNA in areas of lymphoid infiltration. In 3/5 tumours, there was a correlation between the number and distribution of cells expressing the Marek's disease EcoRI-Q gene (meq) and those that carried the lymphoid cell marker AV37. Expression of the MDV-specific phosphoprotein pp38 was infrequent in lymphomas but abundant in a splenic tumour which also expressed the viral glycoprotein gB. Northern blot analysis of lymphocyte fractions purified by immunoaffinity showed that CD4+ and AV37+ fractions from lymphomas expressed meq and the small RNA antisense to ICP4 (SAR). The results are consistent with the notion that transformed cells are CD4+ cells, carrying the AV37 marker and expressing meq and SAR.

Quantification of Marek's disease virus in chicken lymphocytes using the polymerase chain reaction with fluorescence detection

A quantitative assay was developed for Marek's disease virus (MDV). The assay determines the numbers of viral genomes present in samples by polymerase chain reaction (PCR) amplification of a portion of the viral genome for a restricted number of cycles. Fluorescent-tagged primers are used for the PCR amplification which allows quantification of the fluorescent product. Previously, quantitation of Marek's disease virus has required plaque assays, which are laborious and potentially error-prone, and this had limited quantitative comparisons. The PCR assay is rapid, less laborious and can be applied to high levels of accuracy, since replicate assays can be carried out relatively easily. The PCR-based assay assesses the number of viral genomes present in the sample, rather than the numbers of infected cells measured in the plaque assay, however correlation between the two assays is high, suggesting viral copy number per cell may be rather uniform. In crosses between genetically resistant and susceptible animals the PCR-based assay was correlated significantly with subsequent development of disease, and was a better predictor than the plaque assay of the likelihood of development of pathological disease in the birds studied.

Inhibition of nitric oxide: effects on interleukin-1 beta-enhanced ovulation rate, steroid hormones, and ovarian leukocyte distribution at ovulation in the rat

The ovulatory process resembles an inflammatory reaction with an infiltration of leukocytes, production of inflammatory mediators such as cytokines, and a general edema and hyperemia. Nitric oxide (NO), a potent vasodilator and the main mediator of macrophage tumoricidal and bacteriocidal activities, is known to participate in inflammatory reactions and has been shown to mediate the interleukin-1 beta (IL-1 beta)-directed tissue-remodeling events within the ovary. The regulation by NO of ovulation rate, leukocyte distribution, and steroid release in the rat ovary was investigated through use of a combination of in vivo and in vitro models of ovulation and a competitive inhibitor, N-omega-nitro-L-arginine methyl ester (L-NAME), of the NO synthase (NOS) enzyme. Subcutaneous L-NAME (1.5 x 10(-4) mol/kg) administration significantly reduced the in vivo ovulation rate of eCG/hCG-primed rats (L-NAME-treated: 10.6 +/- 1.8 [mean +/- SEM] oocytes per ovary [O/O], 11.0 +/- 1.2 rupture sites per ovary [RS/O]; saline-treated: 18.0 +/- 1.8 O/O, 19.4 +/- 1.1 RS/O; p < 0.01) at 20 h post-hCG. These results were reflected in vitro, where addition of L-NAME (3.5 x 10(-5) mol/L) to LH (0.1 microgram/ml)-perfused ovaries decreased ovulation rate from 8.2 +/- 1.6 to 2.7 +/- 1 ovulations per ovary (p < 0.05) and simultaneously decreased nitrite accumulation at the completion of perfusions from 16.5 +/- 1.9 to 4.1 +/- 0.5 nmol/ml (p < 0.001). The addition of L-NAME to LH+IL-1 beta (4 ng/ml)-perfused ovaries decreased ovulation rate from 15.2 +/- 2.4 to 0.8 +/- 0.8 ovulations per ovary (p < 0.001) and simultaneously decreased nitrite accumulation at 22 h from 22.8 +/- 2.2 to 1.9 +/- 0.6 nmol/ml (p < 0.001). Studies analyzing and manipulating perfusion flow rate indicated that the L-NAME effects on ovulation rate are primarily due to a reduction in flow rate resulting from inhibition of NO, which may be a consequence of the known vasoconstrictor effects of NOS inhibitors. The observed reduction of in vivo ovulation rate by NO inhibition at 20 h post-hCG was associated with a significant reduction in thecal MCA149+ neutrophils at 12 h post-hCG, the expected time of ovulation (L-NAME-treated: 98.4 +/- 9.2 cells per thecal area; saline-treated: 211.5 +/- 11.5 cells per thecal area; p < 0.001), while ED1+ monocytes/macrophages underwent similar but nonsignificant changes. Plasma (20 h post-hCG) and perfusate progesterone were not different with L-NAME treatment, while perfusate estradiol levels were markedly reduced upon addition of L-NAME, suggesting a role for NO in ovulation but not in the process of luteinization. In summary, deprivation of NO by use of the competitive inhibitor, L-NAME, led to fewer ovulations, reduced accumulation of nitrite, a decreased neutrophil count in the theca of preovulatory follicles, and reduced estradiol secretion, while progesterone release remained unaffected. The NO pathway may therefore play an important role in the regulation of ovulation and the mediation of IL-1 beta's pro-ovulatory effects. There are likely to be primarily vascular effects, but also a nonvascular component, to the NO regulation of ovulation, with both components indirectly affecting ovulatory leukocyte distribution and steroid secretion.

Influence of chicken genotype on protection against Marek's disease by a herpesvirus of turkeys recombinant expressing the glycoprotein B (gB) of Marek's disease virus

Two inbred lines of White Leghorn chickens which differ in B-haplotype were immunized at 2 days of age with a thymidine kinase negative (tk-ve) herpesvirus of turkeys (HVT) recombinant expressing the glycoprotein B (gB) gene of Marek's disease virus (MDV) and were challenged 6 days later with 1000 p.f.u. of the highly virulent RB1B strain of MDV. Mock-vaccinated chickens and chickens immunized with a spontaneous tk-ve HVT mutant served as controls. Genetically resistant B21 chickens were protected by immunization with the recombinant as well as by the tk-ve HVT, whereas highly susceptible B13 chickens were partially protected by the recombinant but were not protected by the tk-ve HVT. Rhode Island Red chickens (HPRS RIR), which differ from the White Leghorns at the B locus, were protected by both vaccines but the recombinant conferred a significantly higher level of protection than the tk-ve HVT. The results suggest that the gB gene of MDV serotype 1 has an important role in the induction of protective immunity against highly virulent MDV in genetically susceptible lines of chickens and that vaccinal immunity in White Leghorns might be influenced by the B haplotype.