Discrimination, harassment and non-reporting in UK medical education

CONTEXT

Discrimination and harassment create a hostile environment with deleterious effects on student well-being and education. In this study, we aimed to: (i) measure prevalences and types of discrimination and harassment in one UK medical school, and (ii) understand how and why students report them.

METHODS

The study used a mixed-methods design. A medical school population survey of 1318 students was carried out in March 2014. Students were asked whether they had experienced, witnessed or reported discrimination or harassment and were given space for free-text comments. Two focus group sessions were conducted to elicit information on types of harassment and the factors that influenced reporting. Proportions were analysed using the Wilson score method and associations tested using chi-squared and regression analyses. Qualitative data were subjected to framework analysis. Degrees of convergence between data were analysed.

RESULTS

A total of 259 (19.7%) students responded to the survey. Most participants had experienced (63.3%, 95% confidence interval [CI]: 57.3-69.0) or witnessed (56.4%, 95% CI: 50.3-62.3) at least one type of discrimination or harassment. Stereotyping was the form most commonly witnessed (43.2%, 95% CI: 37.4-49.3). In the qualitative data, reports of inappropriate joking and invasion of personal space were common. Black and minority ethnic students had witnessed and religious students had experienced a greater lack of provision (χ²  = 4.73, p = 0.03 and χ²  = 4.38, p = 0.04, respectively). Non-heterosexual students had experienced greater joking (χ²  = 3.99, p = 0.04). Students with disabilities had experienced more stereotyping (χ²  = 13.5, p < 0.01). Female students and students in clinical years had 2.6 (95% CI: 1.3-5.3) and 3.6 (95% CI: 1.9-7.0) greater odds, respectively, of experiencing or witnessing any type of discrimination or harassment. Seven of 140 survey respondents had reported incidents (5.0%, 95% CI: 2.4-10.0). Reporting was perceived as ineffective and as potentially victimising of the reporter.

CONCLUSIONS

Harassment and discrimination are prevalent in this sample and associated with gender, ethnicity, sexuality, disability and year group. Reporting is rare and perceived as ineffective. These findings have informed local developments, future strategies and the development of a national prevention policy.

Which infants with eczema are at risk of food allergy? Results from a population-based cohort

BACKGROUND

The relationship between early onset eczema and food allergy among infants has never been examined in a population-based sample using the gold standard for diagnosis, oral food challenge.

OBJECTIVE

We characterised the risk of challenge-proven food allergy among infants with eczema in the general population.

METHODS

One-year-old infants (n = 4453 meeting criteria for this analysis) were assessed for history of eczema, received a nurse-administered eczema examination and underwent skin prick testing to peanut, egg and sesame. Those with a detectable wheal to one of the test foods underwent an oral food challenge irrespective of wheal size. The risk of food allergy, stratified by eczema severity and age of onset, was estimated using multivariate logistic regression with population sampling weights.

RESULTS

One in five infants with eczema were allergic to peanut, egg white or sesame, compared to one in twenty-five infants without eczema (OR 6.2, 95% CI 4.9, 7.9, P < 0.001). The prevalence of peanut allergy was low in the absence of eczema (0.7% 95% CI 0.4, 1.1). Infants with eczema were 11.0 times more likely to develop peanut allergy (95% CI 6.6, 18.6) and 5.8 times more likely to develop egg allergy (95% CI 4.6, 7.4) by 12 months than infants without eczema. 50.8% of infants (95% CI 42.8, 58.9) with early eczema onset (<3 months) who required doctor-prescribed topical corticosteroid treatment developed challenge-proven food allergy.

CONCLUSION AND CLINICAL RELEVANCE

Eczema, across the clinical severity spectrum in infancy, is a strong risk factor for IgE-mediated food allergy. Infants with eczema were six times more likely to have egg allergy and 11 times more likely to have peanut allergy by 12 months than infants without eczema. Our data suggest that a heightened awareness of food allergy risk among healthcare practitioners treating infants with eczema, especially if early onset and severe, is warranted.

The influence of childhood traffic-related air pollution exposure on asthma, allergy and sensitization: a systematic review and a meta-analysis of birth cohort studies

The impact of early childhood traffic-related air pollution (TRAP) exposure on development of asthma and allergies remains unclear. Birth cohort studies are the best available study design to answer this question, but the evidence from such studies has not been synthesized to date. We conducted a systematic review and meta-analyses of published birth cohort studies to understand the association between early childhood TRAP exposure, and subsequent asthma, allergies and sensitization. Increased longitudinal childhood exposure to PM2.5 and black carbon was associated with increasing risk of subsequent asthma in childhood (PM2.5 : OR 1.14, 95%CI 1.00 to 1.30 per 2 μg/m(3) and black carbon: OR 1.20, 95%CI 1.05 to 1.38 per 1 × 10(-5) m(-1) ). Also, early childhood exposure to TRAP was associated with development of asthma across childhood up to 12 years of age. The magnitude of these associations increased with age, and the pattern was prominent for PM2.5 . Increasing exposure to PM2.5 was associated with sensitization to both aero- and food allergens. There was some evidence that TRAP was associated with eczema and hay fever. In summary, exposure to TRAP was related to asthma and allergic diseases. However, the substantial variability across studies warrants long-term birth cohort studies with regular repeated follow-ups to confirm these findings.

Paracetamol exposure in pregnancy and early childhood and development of childhood asthma: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

While paracetamol exposure in pregnancy and early infancy has been associated with asthma, it remains unclear whether this is confounded by respiratory tract infections, which have been suggested as an alternative explanation. We undertook a systematic review and meta-analysis of longitudinal studies that reported the association between paracetamol exposure during pregnancy or infancy and the subsequent development of childhood asthma (≥5 years).

METHODS

Two independent researchers searched the databases EMBASE and PUBMED on 12 August 2013 for relevant articles using predefined inclusion and exclusion criteria. Study quality was assessed and results were pooled using fixed effect models or random effect models when moderate between-study heterogeneity was observed. We explicitly assessed whether the observed associations are due to confounding by respiratory tract infections.

RESULTS

Eleven observational cohort studies met the inclusion criteria. Any paracetamol use during the first trimester was related to increased risk of childhood asthma (5 studies, pooled OR=1.39, 95% CI 1.01 to 1.91) but there was marked between-study heterogeneity (I(2)=63%) and only one of these studies adjusted for maternal respiratory tract infections. Increasing frequency of use of paracetamol during infancy was associated with increased odds of childhood asthma (3 studies, pooled OR=1.15, 95% CI 1.00 to 1.31 per doubling of days exposure), but in these same three studies adjusting for respiratory tract infections reduced this association (OR=1.06, 95% CI 0.92 to 1.22).

DISCUSSION

The association during early pregnancy exposure was highly variable between studies and exposure during infancy appears to be moderately confounded by respiratory tract infections. There is insufficient evidence to warrant changing guidelines on early life paracetamol exposure at this time.

Ambient wood smoke exposure and respiratory symptoms in Tasmania, Australia

Wood smoke exposure has been associated with adverse respiratory health outcomes, with much of the current research focused on wood smoke from domestic heating and cooking. This study examined the association between respiratory symptoms and outdoor wood smoke in Launceston, Tasmania, where ~30% of homes use wood burners for domestic heating. This ecological study examined data from participants of the 2004 Tasmanian Longitudinal Health Study postal survey and compared the prevalence of respiratory symptoms in Launceston (n=601) with that in Hobart (n=1071), a larger Tasmanian city with much less wood smoke. Multivariate logistic regression models were used to investigate the associations of interest while adjusting for gender, atopy, history of allergic disease and current smoking status. There were no significant differences in symptom prevalence between Launceston and Hobart. Two subgroup analyses, which examined participants with pre-existing chronic respiratory disease, and those who reported actively using a wood burner in their home, also did not find significant differences. Any impact of wood smoke on non-specific respiratory symptoms might have been overshadowed by other important determinants of respiratory health, such as vehicle exhaust and tobacco smoking, or were too small to have been detected. However, the lack of detectable differences in symptom prevalence might also reflect the success of regulatory action by local governments to reduce wood smoke emissions in Launceston. The results of other epidemiological studies support an association between ambient wood smoke exposure and adverse respiratory health. Further investigations of wood smoke exposure in Australian settings are needed to investigate the lack of significant associations found in this study, especially studies of indoor air quality and health impacts in children and elderly populations.

Asthma management: how effective is it in the community?

BACKGROUND

The National Asthma Campaign (NAC) was launched in Australia in 1989 with the major objective of improving asthma management through the implementation of a six-step asthma management plan.

AIM

The objective of the present study was to analyse the management of asthma in a cohort of adults with self-reported asthma 10 years after the commencement of the NAC.

METHODS

The subjects were participants in the laboratory phase of a cross-sectional epidemiological study conducted in Melbourne in 1999-2000. Participants completed the detailed European Community Respiratory Health Survey, which included specific questions about their asthma management. Participants were included in this analysis if they had a positive response to the question 'Have you ever had asthma?'. This resulted in a total of 435 subjects.

RESULTS

Of the subjects with self-reported asthma, over half of the participants reported that a doctor had ever measured their breathing (52.9%). However, only 10.1% of participants reported that they owned a peakflow meter (PFM) and only 13.3% reported that they had ever been given a written action plan. In comparison with data reported from 1993, doctor measurement of lung function has decreased significantly (P < 0.000 1), as has PFM ownership (P < 0.0001) and, importantly, possession of a written action plan (P = 0.0004).

CONCLUSIONS

Asthma management among adults still falls well short of NAC guidelines. The decline in some key features over recent years suggests that new management and dissemination strategies are required.

Wheeze not current asthma affects quality of life in young adults with asthma

BACKGROUND

A study was undertaken to investigate quality of life in asthma, defined by differing criteria, to see which may be most appropriate in epidemiological studies.

METHODS

The 426 adults were participants in the follow up phase of the European Community Respiratory Health Survey (ECRHS) in Melbourne. As part of the laboratory visit, participants completed the SF-36 quality of life questionnaire, a detailed respiratory questionnaire, and underwent lung function testing.

RESULTS

Both the physical component summary and the mental component summary scores were significantly worse in those with wheeze in the previous 12 months than in those without wheeze. Only the mental component summary score was significantly worse in those with current asthma than in those without. In contrast, in those with current asthma or bronchial hyperreactivity only, neither of the summary scales was significantly different between cases and controls.

CONCLUSIONS

Quality of life is severely impaired in individuals with wheeze in the previous 12 months while individuals with current asthma or bronchial hyperreactivity alone did not appear to have significantly reduced quality of life.

Reduction of peptic ulcer disease and Helicobacter pylori infection but increase of reflux esophagitis in Western Sydney between 1990 and 1998

We aimed to determine if changes in the patterns of upper gastrointestinal diseases at endoscopy have occurred over the past decade. Retrospectively, 917 consecutive patients were selected based on upper endoscopy between June 1 and August 31, in 1990 (n = 217), 1994 (n = 270), and 1998 (n = 430). Demographic, clinical, endoscopic, and histological information were extracted from the medical records on a standardized case record form. Over the eight-year period, follow-up of peptic ulcer (15%, 5%, and 5%, respectively, in 1990, 1994, and 1998, df = 2, P < 0.001), bleeding (22%, 14%, and 13%, P = 0.008), and nausea/vomiting (15%, 16%, and 10%, df = 2, P = 0.003) had become less frequent, but reflux (21%, 19%, and 34%, df = 2, P < 0.001) and dyspepsia (24%, 43%, and 32%, df = 2, P < 0.001) more frequent indications for upper endoscopy. The prevalence of peptic ulcer disease decreased (22%, 15%, and 13%, df = 2, P = 0.025), but the prevalence of reflux esophagitis increased significantly (29%, 30%, and 39%, df = 2, P = 0.010). The prevalence of both the use of nonsteroidal antiinflammatory drugs (NSAIDs) (18%, 20%, and 11%, respectively, in 1990, 1994, and 1998, df = 2, P = 0.004) and H. pylori infection (39% in 1994 and 30% in 1998, df = 1, P = 0.032) decreased. Overall, NSAID use was independently associated with gastric ulcers (OR = 2.39, 95% CI 1.21-4.73, chi2 = 6.31, df = 1, P = 0.012), but not esophagitis. H. pylori infection was independently associated with duodenal ulcers (OR = 4.74, 95% CI 2.30-9.77, chi2 = 17.8, df = 1, P < 0.001), histologically chronic (OR = 166.8, 95% CI 76.1-365.4, chi2 = 313.0, df = 1, P < 0.001) and active (OR = 30.1, 95% CI 17.0-53.5, chi2 = 189.7, df = 1, P < 0.001) gastritis and lymphoid aggregates (OR = 5.49, 95% CI 3.02-9.97, chi2 = 36.3, df = 1, P < 0.001). In conclusion, the prevalence of peptic ulcer disease appears to have been decreasing, whereas reflux esophagitis has been increasing over the past decade in Western Sydney. The decreased use of NSAIDs and decline of H. pylori infection have likely both contributed to the reduction of peptic ulcer disease, but the increase in reflux esophagitis remains to be fully explained.

Demonstration of biofilm in infectious crystalline keratopathy using ruthenium red and electron microscopy

OBJECTIVE

Bacterial biofilm formation has been implicated in the pathogenesis of infectious crystalline keratopathy. Biofilm cannot be visualized by electron microscopy without the addition of a fixative that stabilizes the polysaccharide-rich bacterial extracellular matrix that surrounds the bacterial colonies in a biofilm. We used ruthenium red as a fixative to evaluate corneal biopsy specimens for the presence of bacterial biofilm in three cases of infectious crystalline keratopathy (ICK) and five cases of chronic microbial keratitis without crystalline changes.

DESIGN

Case series with clinicopathologic correlation.

PARTICIPANTS

Eight patients underwent corneal biopsy or therapeutic keratoplasty as part of their management for chronic unresponsive microbial keratitis.

METHODS

The corneal specimens removed were trisected for microbiology, pathology, and transmission electron microscopy (TEM). The TEM specimens were fixed in 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer with 0.05% ruthenium red.

MAIN OUTCOME MEASURES

Demonstration of bacterial biofilm with TEM.

RESULTS

TEM demonstrated organisms with a surrounding extracellular matrix consistent with a bacterial biofilm in the three cases of ICK but not in the five other cases of chronic microbial keratitis.

CONCLUSIONS

The presence of biofilm in ICK can be demonstrated with TEM with appropriate fixation techniques that stabilize the bacterial extracellular matrix. Biofilm stains intensely with periodic acid-Schiff because of the polysaccharide-rich extracellular matrix and weakly with Gram stain because of the high proportion of nonviable organisms. Biofilm formation occurs in ICK but probably not in chronic bacterial keratitis without crystalline changes. Secretion of an extracellular matrix by bacteria to form a biofilm is a response to a nutrient-deprived environment in which growth and replication is depressed. The extracellular matrix of the biofilm may mask bacterial antigens, explaining the relative lack of inflammatory response in these infections. It may also be one of the mechanisms explaining the resistance to in vivo antimicrobial therapy when in vitro sensitivities have been proven.

Recombinant Neisseria meningitidis transferrin binding protein A protects against experimental meningococcal infection

To better characterize the vaccine potential of Neisseria meningitidis transferrin binding proteins (Tbps), we have overexpressed TbpA and TbpB from Neisseria meningitidis isolate K454 in Escherichia coli. The ability to bind human transferrin was retained by both recombinant proteins, enabling purification by affinity chromotography. The recombinant Tbps were evaluated individually and in combination in a mouse intraperitoneal-infection model to determine their ability to protect against meningococcal infection and to induce cross-reactive and bactericidal antibodies. For the first time, TbpA was found to afford protection against meningococcal challenge when administered as the sole immunogen. In contrast to the protection conferred by TbpB, this protection extended to a serogroup C isolate and strain B16B6, a serogroup B isolate with a lower-molecular-weight TbpB than that from strain K454. However, serum from a TbpB-immunized rabbit was found to be significantly more bactericidal than that from a TbpA-immunized animal. Our evidence demonstrates that TbpA used as a vaccine antigen may provide protection against a wider range of meningococcal strains than does TbpB alone. This protection appears not to be due to complement-mediated lysis and indicates that serum bactericidal activity may not always be the most appropriate predictor of efficacy for protein-based meningococcal vaccines.

Persistence of acanthamoeba antigen following acanthamoeba keratitis

AIM

To investigate the hypothesis that persistent corneal and scleral inflammation following acanthamoeba keratitis is not always caused by active amoebic infection but can be due to persisting acanthamoebic antigens

METHODS

24 lamellar corneal biopsy and penetrating keratoplasty specimens were obtained from 14 consecutive patients at various stages of their disease and divided for microscopy and culture. Histological sections were immunostained and screened for the presence of Acanthamoeba cysts by light microscopy. Cultures were carried out using partly homogenised tissues on non-nutrient agar seeded with E coli. Clinical data were obtained retrospectively from the case notes of these patients.

RESULTS

Of the 24 specimens, 20 were obtained from eyes that were clinically inflamed at the time of surgery. Acanthamoeba cysts were present in 16 (80%) of these 20 specimens, while only five (25%) were culture positive. Acanthamoeba cysts were found to persist for up to 31 months after antiamoebic treatment.

CONCLUSION

These findings support the hypothesis that Acanthamoeba cysts can remain in corneal tissue for an extended period of time following acanthamoeba keratitis and may cause persistent corneal and scleral inflammation in the absence of active amoebic infection. In view of these findings, prolonged intensive antiamoebic therapy may be inappropriate when the inflammation is due to retained antigen rather than to viable organisms

In vitro antibiotic resistance in bacterial keratitis in London

AIM

To document changes in the profile of bacterial isolates from cases of keratitis and changes in their susceptibility to first line antibiotic therapies.

METHODS

A retrospective review was performed of all bacterial isolates from cases of keratitis seen between 1984 and 1999. In vitro laboratory susceptibilities to antibiotics were determined by the Kirby-Bauer disc diffusion method. The number of isolates, changes in the proportion of bacterial types, and the number that were fully resistant to monotherapy (ofloxacin), dual therapy (gentamicin and cefuroxime), and prophylactic treatment (chloramphenicol) were calculated.

RESULTS

There were 1312 bacterial isolates over 16 years. Gram positive bacteria accounted for 54.7% of isolates and Staphylococcus species (33.4%) were the most frequently isolated organisms. During the study period there has been an increase in the proportion of Pseudomonas species isolates but no overall increase in the proportion of Gram negative isolates. There has not been an increase in the proportion of isolates resistant to ofloxacin since 1995 or an increase in resistance to the combination of gentamicin and cefuroxime. However, since 1984 there has been a significant increase in proportion of Gram negative organisms resistant to chloramphenicol (p=0.0019).

CONCLUSIONS

An increase in the in vitro resistance of organisms to first line therapies for bacterial keratitis has not been observed. An increased resistance to chloramphenicol indicates that this drug is unlikely to provide prophylactic cover when Gram negative infection is a risk. Continued monitoring for the emergence of antibiotic resistance is recommended.

Bacterial biofilm on contact lenses and lens storage cases in wearers with microbial keratitis

Bacterial biofilm formation on contact lenses (CLs), and CL storage cases may be a risk factor for CL-associated corneal infection and may explain the persistence of organisms in CL storage cases. This study evaluated biofilm formation on, and microbial contamination of, CLs and CL storage cases from patients with microbial keratitis. Contact lenses and CL storage cases from 20 wearers with microbial keratitis were sampled microbiologically and visualized using scanning electron microscopy (SEM). Culture results from the cornea were also noted. Bacterial biofilm was present more frequently (P < 0.05) on CL storage case surfaces (17/20) compared with CL surfaces (11/20) and biofilm density was significantly greater on case surfaces (P < 0.05). There was no association between poor compliance and microbial contamination of the CL storage case, nor between poor compliance and biofilm formation or density on the CL or CL storage case. Biofilm formation occurred equally frequently with hydrogen peroxide and chlorine release care systems. Microbial keratitis in CL wearers is frequently associated with bacterial biofilm in the CL storage case. Despite the use of current CL disinfection systems, the CL storage case is a favourable environment for proliferation of certain organisms. Biofilm on CLs may prolong the retention time of organisms at the ocular surface and increase their potential pathogenicity.

Group B streptococcus (GBS) colonisation among expectant Irish mothers

Group B streptococci (GBS) have been recognised for more than three decades as a serious cause of perinatal morbidity and neonatal mortality. The aim of this study was to accurately determine the prevalence of GBS carriage and the serotype distribution among pregnant Irish women. 504 women attending antenatal clinics had two swabs (one perianal and one low vaginal) taken in the last four weeks of their pregnancy. These were placed in Todd Hewitt broth and then subcultured onto solid media. Serotyping of the isolates was performed by the Central Public Health Laboratory, London. GBS colonised women were treated with prophylactic antibiotics in labour and their infants received prophylaxis for 48 hours. 129 women (25.6%) were found to be asymptomatically colonised with GBS. Dual site screening (low-vaginal and perianal) identified 5% more GBS carriers than one site would have done. Serotypes identified included types I (30%), II (17%), III (30%), IV (1%) and V (9%). GBS colonisation is very common in Irish pregnant women and therefore a strategy for management in pregnancy ought to be developed in order to reduce the recognised occurrence of neonatal morbidity and mortality caused by this organism.

Relationship between airway microvascular leakage, edema, and baseline airway functions

This study was designed to examine the relationship among microvascular leakage, edema, and baseline airway function. Microvascular leakage was induced in the airways of anesthetized, tracheostomized New Zealand White rabbits (n = 22) by using nebulized N-formyl-methionyl-leucyl-phenylalanine (10 mg) and was measured in the trachea by using the Evans blue dye technique. Airway wall thickness was assessed morphometrically in the right main bronchus after Formalin fixation at a pressure of 25 cmH2O. Areas calculated included the mucosal wall area, the adventitial wall area, the total wall area, and the percentage of total wall area consisting of blood vessels. A neutrophil count was also performed by analyzing numbers of cells in both the mucosal wall area and the adventitial wall area. Airway function was assessed before and 30 min after challenge with N-formyl-methionyl-leucyl-phenylalanine by determining airway resistance, functional residual capacity, specific airway resistance, and flow-volume and pressure-volume curves (after paralysis of the animals with suxamethonium). The concentration of Evans blue dye in tracheal tissue ranged from 31.3 to 131.2 micrograms. There was a significant correlation between this concentration and both the adventitial wall area (P < 0.01) and mucosal neutrophil numbers (P < 0.005). There was no correlation between Evans blue concentration and either blood vessel area or changes in respiratory physiology parameters before and after challenge. There was no significant difference between any respiratory physiology measurements before and after challenge. We conclude that an increase in microvascular leakage correlates with airway edema in the adventitia; however, these airway changes have no significant effect on airway elastic or resistive properties.

Outcome of acanthamoeba keratitis treated with polyhexamethyl biguanide and propamidine

OBJECTIVE

This study investigates the clinical outcome of Acanthamoeba keratitis treated with polyhexamethyl biguanide (PHMB) and propamidine isethionate (Brolene).

DESIGN

A retrospective review of all patients treated for Acanthamoeba keratitis between September 1992 and February 1995 was carried out. All patients were treated with PHMB 0.02% and propamidine 0.1% hourly for 3 days, the frequency reduced to four to six times daily according to clinical response.

MAIN OUTCOME MEASURES

Age, gender, result of laboratory investigation, duration of disease before diagnosis, visual acuity (VA) pretreatment and post-treatment, need for keratoplasty, and presence of adverse reaction were measured.

RESULTS

One hundred eleven cases were identified in 105 patients (60 male, 45 female; mean age, 32). Ninety-two percent of infections were in contact lens wearers. The clinical diagnosis was confirmed by corneal culture or histopathology in 64 cases (57.7%). The diagnosis was made "early" (within 28 days) in 65 cases (58.6%). Twenty-one (18.9%) were "intermediate" (28 days-2 months) and 20 (18%) were "late" (> 2 months) diagnoses. Overall post-treatment VA was 6/12 or better in the majority (88/111, 79.3%) of cases, and 18 (16.2%) had VA of 6/36 or worse. The VA of > or = 6/12 was achieved by 90.8% of the early, 71.4% of the intermediate, and 65% of the late groups. Clinical relapses occurred in 19 patients on reducing the therapy. Treatment toxicity was never serious and consisted only of stinging or superficial punctate keratopathy. Keratoplasty was indicated in only ten patients, and disease activity was controlled adequately in all patients before grafting.

CONCLUSIONS

Combined treatment with PHMB and propamidine is well tolerated, nontoxic, and effective. Typically, visual outcome is favorable and the requirement for keratoplasty reduced markedly.

Assessment of a standard treatment protocol on visual outcome following presumed bacterial endophthalmitis

AIMS

The aim of this prospective study was, firstly, to judge the effect of early aggressive treatment with a standardised regimen of high dose broad spectrum intraocular and systemic antibiotics on visual outcome and, secondly, to assess the sensitivity of isolated organisms to the treatment regimen utilised.

METHODS

Thirty two consecutive patients presenting with presumed bacterial endophthalmitis were treated and completed follow up. In every case, intraocular sampling was undertaken and treatment with intraocular vancomycin, amikacin, and systemic ciprofloxacin was commenced immediately, followed by systemic steroids 1 day later.

RESULTS

In 69% of patients vision improved with 47% achieving a final visual acuity of 6/36 or better and 31% achieving 6/12 or better. Of the intraocular samples taken from post-surgical and post-traumatic cases, 10/27 (37%) and 3/5 (60%) were culture positive, respectively. All the bacteria isolated were sensitive to at least one of the three antibiotics used.

CONCLUSIONS

The study demonstrated that the combination of vancomycin, amikacin, and ciprofloxacin is adequate as a standard regimen for the treatment of most patients with suspected bacterial endophthalmitis. The prognosis for a good visual outcome, however, remains poor with 15/27 (55%) post-surgical and 2/5 (40%) post-traumatic cases achieving a final acuity of 6/60 or less.

Biofilm formation in infectious crystalline keratopathy due to Candida albicans

Infectious crystalline keratopathy (ICK) is an uncommon, indolent corneal infection in which the slow clinical course contrasts with the rapid laboratory growth and microbiological sensitivities of the infecting organism. This prospective study aimed to determine whether biofilm production was the cause of this disparity. A case of failed medical management of ICK in a patient with Stevens-Johnson syndrome is presented. A penetrating keratoplasty yielded corneal tissue that was freshly fixed for electron microscopy using 0.05% ruthenium red and 2.5% gluteraldehyde. Candida albicans was grown from 3/3 broths, and fungi with morphology consistent with Candida were seen on histological examination. Electron microscopy revealed microorganisms morphologically typical of Candida surrounded by a polysaccharide-rich glycocalyx consistent with a biofilm. We concluded that Candida albicans is capable of producing a biofilm and is a known cause of ICK. This case is supportive evidence that biofilm production is associated with cases of ICK and may explain the chronic, pauciinflammatory features of ICK and its relative resistance to antibiotic treatment.

Candida endophthalmitis

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Epidemiology of Pseudomonas aeruginosa keratitis in contact lens wearers

This study evaluated the epidemiology of Pseudomonas aeruginosa keratitis in contact lens (CL) wearers; the relationships between CL storage case contamination and CL hygiene practice and between CL hygiene and the development of keratitis. Sixteen CL wearers with keratitis were compared with 44 asymptomatic controls. Lens hygiene practice was assessed and CL care materials, domestic water sites and endogenous sites were evaluated microbiologically. Poor CL hygiene was not associated with Ps. aeruginosa keratitis. There was an association between keratitis and bacterial contamination of the CL and storage case (P < 0.0005). Lens and storage case contamination were not significantly associated with poor hygiene. No domestic or endogenous source for Ps. aeruginosa was found. Causative organisms may be derived from other sources, but CLs and CL storage cases provide a favourable environment for Ps. aeruginosa colonization. Changing the CL care environment to one less favourable for Ps. aeruginosa may help to eliminate this problem.

A review of 72 consecutive cases of Acanthamoeba keratitis, 1984-1992

A review of consecutive cases of Acanthamoeba keratitis presenting since 1984 was undertaken in order to assess prognostic factors, the success of culture procedures and the outcome of medical and surgical management, with reference to current clinical practice. Seventy-two consecutive cases (77 eyes) of Acanthamoeba keratitis have been managed. Sixty-four patients were contact lens wearers, 28 of these wearing disposable lenses. Superficial corneal involvement and perineural infiltrates were common in those diagnosed less than a month after first symptoms, designated 'early' presentation. Ring infiltrates and ulceration with stromal lysis characterised those presenting at 1-2 months ('intermediate') or after 2 months ('late'); these groups also progressed more frequently to hypopyon, scleritis, glaucoma and cataract formation. Positive corneal cultures were obtained in 10 of 14 (71%) intermediate and 17 of 23 (74%) late cases; early cases underwent epithelial biopsy but formal trephine biopsy was not usually justified (1 of 35 cases) and only 19 of 35 (54%) were tissue-positive. Microbial co-isolates were obtained from 20 corneas. Thirty-four penetrating keratoplasties were performed in 23 eyes, 21 whilst inflamed and 13 when quiet. Of 13 failures in inflamed eyes, 9 were due to recurrence of Acanthamoeba infection. Medical cure is known to have been achieved in 64 of 73 (88%) eyes, 4 of the original 77 having been lost to follow-up abroad. Fifty-eight of 73 eyes (79%) achieved a final visual acuity of 6/12, and of the culture-positive cases, 32 of 46 (70%) achieved 6/12.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation of a putative fimbrial adhesin from Bordetella pertussis and the identification of its gene

We report the purification of a minor Bordetella pertussis fimbrial subunit, designated FimD, and the identification of its gene (fimD). FimD could be purified from the bulk of major fimbrial subunits by exploiting the fact that major subunit-subunit interactions are more stable in the presence of SDS than minor-major subunit interactions. To locate the gene for FimD, internal peptides of FimD were generated, purified and sequenced. Subsequently, an oligonucleotide probe, based on the primary sequence of one peptide, was used to clone fimD. The primary structure of FimD, derived from the DNA sequence of its gene, showed homology with a number of fimbrial adhesins. Most pronounced homology was observed with MrkD, a fimbrial adhesin derived from Klebsiella pneumoniae. These observations suggest that FimD may represent a B. pertussis fimbrial adhesin. With a fimD-specific probe we detected the presence of a fimD homologue in Bordetella parapertussis and Bordetella bronchiseptica but not in Bordetella avium. Cloning and sequencing revealed that the B. parapertussis and B. bronchiseptica fimD product differed from the B. pertussis fimD product in 20 and 1 amino acid residues, respectively. Since B. bronchiseptica is normally not a human pathogen, but causes respiratory disease in a wide range of non-human mammalian species, this may suggest that FimD recognizes a receptor that is well conserved in mammalian species. An in-frame deletion in fimD completely abolished FimD expression and also affected the expression of the major subunits Fim2 and Fim3 suggesting that, in contrast to other adhesins that are minor components of fimbriae, FimD is required for formation of the fimbrial structure.

Coexistence of sick sinus rhythm and atrial flutter-fibrillation

A 58-year-old man with hypertensive cardiovascular disease and atrial flutter underwent electrophysiologic studies, including multiple intra-atrial recordings and atrial stimulation. Although the surface ECG suggested the presence of atrial flutter, intra-atrial recordings demonstrated the presence of (1) sinus-like rhythm localized to an area of approximately 5 mm in and around the region of the sinus node, which was protected by entrance block; (2) flutter and/or fibrillation of the remaining parts of the right atrium; (3) fibrillation of the left atrium; and (4) transient degeneration of flutter into fibrillation at right atrial sites, with predominant flutter activity. Although a major part of the right atrium was in flutter and/or fibrillation, we could assess sinus node function by overdrive stimulation of the area of sinus node-activity. Sinus node function studied revealed an underlying sick sinus syndrome.

Prediction of late ischemic complications after cerebral aneurysm surgery by the intraoperative measurement of cerebral blood flow

The response of cerebral blood flow (CBF) to drug-induced hypotension was measured in 20 patients who underwent craniotomy for clipping of a cerebral aneurysm following subarachnoid hemorrhage. A modified intravenous xenon-133 injection technique was used to monitor CBF. In 15 patients, CBF increased significantly with hypotension, and only one developed a late neurological deficit. In five patients, CBF fell with halothane-induced hypotension, and four developed delayed neurological deficits. Measurement of the intraoperative CBF response to halothane-induced hypotension may reveal those patients at greatest risk of developing late neurological deficits and who require more intensive postoperative monitoring and early use of the induced hypertension technique.

Computed tomography of fetal specimens

Computed tomography has been used to provide cross-sectional images of fetal specimens. This technique allows us to gain information on anatomic malformations and in general is a useful tool for research and teaching.

Accuracy of ventricular volume estimation

Sources of error in the estimation of ventricular volume from CAT scans are discussed and the accuracy of the measurement assessed. Two methods of calculating ventricular volume from an intraventricular injection of radioisotope are described and compared. Finally, the CAT scan and isotope methods are compared and contrasted. The error associated with a single measurement of volume by any of these techniques is between 20% and 30%. In patients with no ventricular catheter there is no choice other than to use CAT scanning, but if intraventricular injection is possible this method offers a potentially more accurate volume determination because of his higher signal-to-noise ratio.

Three cases of granulomatous arachnoiditis after myelography

Arachnoiditis occurring after myelography is well recognized and the mechanism is understood. Three cases of arachnoiditis caused by oily myelographic contrast media are presented. This complication of myelography may occur even if recognized precautions are observed. The general problem of encystment of dye with a chronic inflammatory process, fibrosis and granuloma formation is described.