Antimicrobial resistance impacts clinical outcome of granulomatous colitis in boxer dogs

BACKGROUND

Escherichia coli have recently been identified within the colonic mucosa of Boxer dogs with granulomatous colitis (GC). Eradication of invasive E. coli is associated with clinical and histological remission.

OBJECTIVES

To determine antimicrobial susceptibility profiles of E. coli strains from GC and healthy dogs, and the association of antimicrobial resistance with clinical outcome.

ANIMALS

Fourteen Boxer dogs with GC and 17 healthy pet dogs.

METHODS

Prospective study: E. coli was cultured from GC biopsies and rectal mucosal swabs of healthy dogs. Individual strains were selected by phylogroup and overall genotype, determined by triplex- and random amplified polymorphic DNA-polymerase chain reaction respectively. Antimicrobial susceptibility was determined by broth microdilution minimal inhibitory concentration.

RESULTS

Culture yielded 23 E. coli strains from GC (1-3/dog, median 2) and 34 strains from healthy (1-3/dog, median 2). E. coli phylogroups were similar (P=.18) in GC (5A, 7B1, 5B2, 6D) and healthy (2A, 10B1, 15B2, 7D). Resistance to ampicillin, amoxicillin-clavulanate, cefoxitin, tetracycline, trimethoprim-sulfa (TMS), ciprofloxacin, and chloramphenicol was greater (P<.05) in GC (21-64%) than healthy (0-24%). Enrofloxacin resistant E. coli were isolated from 6/14 GC versus 0/17 healthy (P=.004). Of the enrofloxacin resistant cases, 4/6 were also resistant to macrophage-penetrating antimicrobials such as chloramphenicol, rifampicin, and TMS. Enrofloxacin treatment before definitive diagnosis was associated with antimicrobial resistance (P<.01) and poor clinical outcome (P<.01).

CONCLUSIONS AND CLINICAL IMPORTANCE

Antimicrobial resistance is common among GC-associated E. coli and impacts clinical response. Antimicrobial therapy should be guided by mucosal culture and antimicrobial susceptibility testing rather than empirical wisdom.

Remission of histiocytic ulcerative colitis in Boxer dogs correlates with eradication of invasive intramucosal Escherichia coli

BACKGROUND

Historically, histiocytic ulcerative (HUC) (or granulomatous) colitis of Boxer dogs was considered an idiopathic immune-mediated disease with a poor prognosis. Recent reports of dramatic responses to enrofloxacin and the discovery of invasive Escherichia coli within the colonic mucosa of affected Boxer dogs support an infectious etiology.

HYPOTHESIS

Invasive E. coli is associated with colonic inflammation in Boxer dogs with HUC, and eradication of intramucosal E. coli correlates with clinical and histologic remission.

ANIMALS

Seven Boxer dogs with HUC.

METHODS

Prospective case series. Colonic biopsies were obtained at initial evaluation in 7 dogs, and in 5 dogs after treatment with enrofloxacin. Biopsies were evaluated by standardized histopathology, and fluorescence in situ hybridization (FISH) with probes to eubacteria and E. coli.

RESULTS

Intramucosal E. coli was present in colonic biopsies of 7/7 Boxers with HUC. Clinical response was noted in all dogs within 2 weeks of enrofloxacin (7 + or - 3.06 mg/kg q24 h, for 9.5 + or - 3.98 weeks) and was sustained in 6 dogs (median disease-free interval to date of 47 months, range 17-62). FISH was negative for E. coli in 4/5 dogs after enrofloxacin. E. coli resistant to enrofloxacin were present in the FISH-positive dog that relapsed.

CONCLUSIONS AND CLINICAL RELEVANCE

The correlation between clinical remission and the eradication of mucosally invasive E. coli during treatment with enrofloxacin supports the causal involvement of E. coli in the development of HUC in susceptible Boxer dogs. A poor response to enrofloxacin treatment might be due to colonization with enrofloxacin-resistant E. coli.

Fluorescence in situ hybridization confirms clearance of visible Helicobacter spp. associated with gastritis in dogs and cats

BACKGROUND

The results of studies examining the role of Helicobacter spp. in the pathogenesis of canine and feline gastritis are inconclusive. Furthermore, data evaluating the effectiveness of medical therapy for eradication of Helicobacter infection are limited.

AIM

To detect Helicobacter spp. in mucosal biopsies of dogs and cats diagnosed with gastritis, with fluorescence in situ hybridization (FISH).

ANIMALS

Three dogs and 2 cats with signs of chronic gastrointestinal disease.

METHODS

Dogs and cats infected with Helicobacter spp. were treated with triple antimicrobial therapy and fed an elimination diet for 21 days. Helicobacter spp. status in endoscopic (3 dogs, 1 cat) or surgical biopsies (1 cat) of gastric mucosa was compared pre- and posttreatment in each animal by histology, FISH analysis, and polymerase chain reaction (PCR).

RESULTS

Gastritis of varying severity with intraglandular spiral bacteria was observed in all animals. Pretreatment diagnostic tests confirmed the presence of mucosal Helicobacter spp. in all animals by FISH and histopathology and in 4/5 animals by PCR. Rapid resolution of vomiting episodes was observed in all animals. Gastric biopsies performed after triple therapy revealed clearance of visible Helicobacter spp. by histopathology and negative FISH analysis, as well as PCR in all animals.

CONCLUSIONS AND CLINICAL IMPORTANCE

Application of FISH to routine biopsy specimens enabled rapid and specific identification of Helicobacter spp. within the gastric mucosa of dogs and cats. Although medical therapy was useful in resolution of clinical signs and clearance of visible Helicobacter spp. in gastric biopsies, gastric inflammation persisted.

Analysis of reproductive performance of lactating cows on large dairy farms using machine learning algorithms

The fertility of lactating dairy cows is economically important, but the mean reproductive performance of Holstein cows has declined during the past 3 decades. Traits such as first-service conception rate and pregnancy status at 150 d in milk (DIM) are influenced by numerous explanatory factors common to specific farms or individual cows on these farms. Machine learning algorithms offer great flexibility with regard to problems of multicollinearity, missing values, or complex interactions among variables. The objective of this study was to use machine learning algorithms to identify factors affecting the reproductive performance of lactating Holstein cows on large dairy farms. This study used data from farms in the Alta Genetics Advantage progeny-testing program. Production and reproductive records from 153 farms were obtained from on-farm DHI-Plus, Dairy Comp 305, or PCDART herd management software. A survey regarding management, facilities, labor, nutrition, reproduction, genetic selection, climate, and milk production was completed by managers of 103 farms; body condition scores were measured by a single evaluator on 63 farms; and temperature data were obtained from nearby weather stations. The edited data consisted of 31,076 lactation records, 14,804 cows, and 317 explanatory variables for first-service conception rate and 17,587 lactation records, 9,516 cows, and 341 explanatory variables for pregnancy status at 150 DIM. An alternating decision tree algorithm for first-service conception rate classified 75.6% of records correctly and identified the frequency of hoof trimming maintenance, type of bedding in the dry cow pen, type of cow restraint system, and duration of the voluntary waiting period as key explanatory variables. An alternating decision tree algorithm for pregnancy status at 150 DIM classified 71.4% of records correctly and identified bunk space per cow, temperature for thawing semen, percentage of cows with low body condition scores, number of cows in the maternity pen, strategy for using a clean-up bull, and milk yield at first service as key factors.

Relationship between exposure to domestic allergens and bronchial hyperresponsiveness in non-sensitised, atopic asthmatic subjects

BACKGROUND

The effect of exposure to allergens not causing sensitisation in atopic asthmatic subjects has not previously been studied. A study was undertaken to assess the degree of asthma severity (measured by spirometry, airway reactivity and exhaled nitric oxide) in atopic asthmatic patients not sensitised to the domestic allergen to which they were exposed.

METHODS

Dust samples were collected from the living room carpet and mattress in the homes of 248 subjects and dust mite, cat and dog allergen concentrations were measured. Spirometry, non-specific bronchial reactivity (BR), and exhaled nitric oxide (eNO) were ascertained. Patients' sensitisation status was assessed by skin prick testing.

RESULTS

Adult atopic asthmatics not sensitised to mite but exposed to high levels of mite allergen had significantly more severe BR than subjects not exposed to high levels of mite (PD(20), geometric mean (GM) 0.21 mg (95% CI 0.09 to 0.47) v 0.86 mg (95% CI 0.44 to 1.67), mean ratio difference 4.1 (95% CI 1.5 to 11.4), p=0.008). Subjects not sensitised but exposed to high levels of dog allergen also had significantly more severe BR than subjects not exposed (PD20 GM 0.16 v 0.52 mg, mean ratio difference 3.3 (95% CI 1.2 to 9.2), p=0.01). The differences in BR between these groups were still significant after adjusting for confounding factors. This effect of greater airway reactivity was not seen in subjects exposed but not sensitised to cat allergens.

CONCLUSION

Atopic asthmatic subjects who are exposed to high levels of dust mite or dog allergens but not sensitised to these allergens have evidence of increased airway reactivity.

Canine inflammatory bowel disease: retrospective analysis of diagnosis and outcome in 80 cases (1995-2002)

The case records of 80 dogs in which idiopathic inflammatory bowel disease (IBD) had been diagnosed were reviewed, and owners were contacted for follow-up information using a telephone questionnaire. The types of IBD encountered were lymphocytic (n=6), lymphocytic-plasmacytic (n=38), eosinophilic (n=6) and mixed inflammation (n=30). Prednisolone, sulphasalazine, metronidazole and tylosin were the most frequently prescribed medications. At follow-up, 21 dogs (26 per cent) were classified as being in remission (for a median of 14 months), 40 dogs (50 per cent) had intermittent clinical signs (for a median of 17 months) and three dogs (4 per cent) had uncontrolled disease (for a median of 19 months). Ten dogs (13 per cent) had been euthanased due to refractory IBD and four of these had entered remission for a median of 21 months prior to developing severe relapse and refractoriness to further treatment. Six dogs (8 per cent) had been euthanased or had died for reasons unrelated to IBD. Hypoalbuminaemia at the time of diagnosis was significantly associated with a negative outcome (P=0.0007). No association was found between the site (P=0.75), type (P=0.44) and severity (P=0.75) of disease. Dietary change to single protein and carbohydrate commercial diets had no association with outcome (P=0.12). Owner assessment of quality of life at follow-up was significantly associated with outcome (P=0.006).

Modulation of spontaneous Ca2+-activated Cl- currents in the rabbit corpus cavernosum by the nitric oxide-cGMP pathway

The whole-cell perforated patch clamp technique was used to study membrane currents in isolated rabbit corpus cavernosum smooth muscle cells. Depolarization from -80 mV to the range -40 to -10 mV evoked a nifedipine-sensitive Ca(2+) current that was followed by a slower inward current that activated over several hundred milliseconds. The slow current reversed near the Cl(-) equilibrium potential (E(Cl)) and was reduced by anthracene-9-carboxylic acid (A9C; 1 mm) and niflumic acid (100 microm), suggesting that it was a Ca(2+)-activated Cl(-) current. When held constantly at -60 mV, over 70% of cells fired spontaneous transient inward currents (STICs), the amplitudes of which were reduced by A9C and niflumic acid. STICs reversed near E(Cl) in a symmetrical Cl(-) gradient and when [Cl(-)](o) was substituted with glutamate or I(-), the reversal potential shifted to more positive or more negative values, respectively, confirming that STICs were mediated by Cl(-) channels. STICS were also blocked by cyclopiazonic acid, 2-aminoethoxydiphenyl borate (2-APB) and 2-nitro-4-carboxyl-N,N-diphenylcarbamate (NCDC), suggesting that they depended on IP(3)-mediated Ca(2+)-release from the sarcoplasmic reticulum. Modulation by the NO-cGMP pathway was investigated by applying nitrosocysteine, 3-(5-hydroxymethyl-2-furyl)-1-benzyl indazole (YC-1), and 8-bromo cGMP, all three of which abolished STIC activity. YC-1 also reduced noradrenaline-evoked inward currents, but had no effect on similar currents evoked by caffeine, suggesting that cGMP selectively inhibited IP(3)-mediated Ca(2+) release. We propose that Ca(2+)-activated Cl(-) currents underlie detumescent tone in the corpus cavernosum, and that modulation of this mechanism by the NO-cGMP pathway is important during penile erection.

Stringent environmental control in pregnancy and early life: the long-term effects on mite, cat and dog allergen

BACKGROUND

As part of a primary prevention of asthma study, we measured the effect of environmental control measures on Der p 1, Fel d 1 and Can f 1 over a 3.5-year period.

METHODS

High-risk infants (both parents atopic) without pets, were randomized to the Active group (n = 142, vinyl flooring in child's room, allergen-impermeable cot mattress, hot-washable toy, mite allergen-impermeable encasings to parental bed and to child's bed when older, high filtration vacuum cleaner, hot-washing of bedding) or the Control group (n = 136, no intervention), in early pregnancy. Dust samples from the parental mattress, living room floor, child's mattress and floor at baseline (pregnancy), birth and at 3 years were analysed for Der p 1, Fel d 1 and Can f 1.

RESULTS

A total of 278 families completed the baseline visit, 259 the birth visit and 239 the 3-year visit. In the Active group at 3 years, 58% remained compliant with all measures likely to reduce the child's exposure to allergen and 77% of parents still used encasings on their bed. Levels of Der p 1, Fel d 1 and Can f 1 were significantly lower in the Active group in the child's floor and the child's mattress at 3 years compared to the Control group (P < 0.001). For the parental mattress, the levels of Der p 1 and Fel d 1 were lower in the Active group (P < 0.001) and there was a strong trend towards a lower level for Can f 1. There was no difference in the levels of any of the allergens between the groups in the living room floor. Childrens' bedrooms with no detectable mite, cat or dog allergen were significantly more common in the Active than the Control group (25 vs. 2, P < 0.001).

CONCLUSIONS

Environmental control measures are effective in substantially reducing levels of Der p 1, Fel d 1 and Can f 1 in homes without pets in the long term and are acceptable to families. The effect of this environmental manipulation on the development of sensitization and allergic disease remains to be seen.

Household characteristics and mite allergen levels in Manchester,UK

BACKGROUND

Mite allergen levels vary enormously between different homes in the same geographical area. No large scale studies of mite levels in Manchester homes has been conducted to identify factors associated with higher levels.

OBJECTIVES

To quantify exposure to mite allergens and to identify characteristics associated with higher Der p 1 levels in a large sample of homes in Manchester, UK.

METHODS

Der p 1 was measured in dust from the living room floor, sofa, bedroom floor and mattress in 564 homes. Data on household characteristics were collected by administering a questionnaire. Univariate and multivariate analyses were performed to identify household characteristics associated with higher mite allergen levels.

RESULTS

Der p 1 levels were highest in the mattress (GM 1.19 microg/g, 95% CI 0.98-1.45, P < 0.001). Two-thirds of homes contained Der p 1 levels > 2 microg/g in at least one dust reservoir, and 40.3% contained Der p 1 greater than 10 microg/g. There was a large range in Der p 1 levels between homes (> 10(3)-fold). Damp and condensation were common findings in homes. In the multivariate analyses, factors associated with higher Der p 1 levels in more than one dust reservoir were older homes, older living room carpets, damp, condensation and mixed glazing. Older mattresses were associated with higher mite allergen levels in the mattress where the age of the mattress was recorded. Twenty-four homes contained no detectable mite allergen, six of which reported damp.

CONCLUSIONS

Mite allergen levels are high enough in two of every three homes to be associated with an increase in the risk of sensitization to mite. Factors such as older homes, carpets and mattresses, damp and condensation are associated with higher mite allergen. However, mite allergen levels are occasionally unpredictably very low in homes with risk factors for high levels.

Personal exposure to house dust mite allergen in bed: nasal air sampling and reservoir allergen levels

BACKGROUND

Assessment of personal exposure to dust mite allergen has relied on proxy measures. Only recently has a means to directly measure inhaled allergen particle number become available (the intra-nasal air sampler).

OBJECTIVE

To quantify inspired dust mite group 1 and group 2 allergen-bearing particles in bed in undisturbed conditions prior to sleep by nasal air sampling and to investigate the relationship between inhaled particles and reservoir allergen levels.

METHODS

Twelve volunteers wore nasal samplers in bed for 6 evenings, nose-breathing in undisturbed conditions. Allergen-bearing particles ('halos') were detected by immunostaining for Der p 1, Der p 2, or Der p 1 and Der p 2 together, and counted by light microscopy. Count data were square root transformed for analysis of variance. Mattress dust samples were assayed for Der p 1 and Der p 2 concentrations.

RESULTS

Square root detransformed mean particle counts per 30-min sample were: Der p 1, 4.22; Der p 2, 5.9; Der p 1 + Der p 2, 4.87; and for all samples, 5.01, with no difference between the groups. With replicate samples, halo number correlated significantly with mattress allergen concentrations (Der p 1 r = 0.80, P < 0.01; Der p 2 r = 0.68, P < 0.02).

CONCLUSION

Nasal air sampling can be used to quantify nocturnal Der p exposure in undisturbed conditions in an area with moderate exposure to mite allergen and can provide a direct measure of inhaled mite allergen. The choice of either Der p 1 or Der p 2 is appropriate for this purpose.

Decreased prevalence of sensitization to cats with high exposure to cat allergen

We investigated the relationship between current exposure to cat allergen and sensitization to cats. A questionnaire was administered and skin prick testing and home visits for collection of dust samples (Fel d 1; ELISA) were performed in 2502 adults (mean age, 31.8 years; age range, 18-58 years; 1251 women). The results for Fel d 1 in relation to sensitization to cats were analyzed for 10 deciles of cat allergen exposure (cut points [microg/g]: 0.05, 0.34, 0.48, 0.72, 1.13, 1.92, 7.2, 44, 151). The prevalence of sensitization to cat was significantly decreased in the lowest and the highest exposure groups. In the multivariate regression analysis (age, sex, socioeconomic status, and current smoking being adjusted for), the risk of sensitization to cats was significantly increased with medium exposure to Fel d 1 (3rd centile, OR 2.3, 95% CI 1.2-4.4, P =.01; 4th centile, OR 2.1, 95% CI 1.1-4.0, P =.03; 5th centile, OR 2.2, 95% CI 1.2-4.3, P =.04, 6th centile, OR 2.5, 95% CI 1.3-4.9, P =.005). These results indicate that the prevalence of sensitization to cat is decreased in the lowest and highest cat allergen exposure groups.

Risk factors for asthma in urban Ghana

BACKGROUND

Asthma is increasing in prevalence and severity in Africa. Previous studies have suggested that the prevalence of atopy in West Africa was low.

OBJECTIVE

We sought to investigate the risk factors for asthma in Ghanaian school children.

METHODS

Fifty children (age range, 9-16 years) with a physician diagnosis of asthma and asthma symptoms within the previous 12 months and 50 age- and sex-matched healthy control subjects were randomly selected and evaluated by means of questionnaire, skin testing, total and specific IgE measurements, and allergen level measurements from bed dust samples (mite, cat, dog, and cockroach).

RESULTS

Asthmatic children were exposed to higher levels of mite allergens than were control children (geometric mean, 19 microg/g [95% CI, 13.6-26.5] vs. 11.2 microg/g [7.4-15.7]; P <.05). Cat and dog allergen levels were low. There was a marked dissociation between skin test responses and the presence of specific IgE to cat and dog (CAP method). However, 84% of subjects with positive cat dander-specific IgE levels in cat CAP tests and negative skin test responses did not have Fel d 1-specific IgE (chimeric ELISA). In the univariate analysis significant associations with the patient group were found for sensitization to mite (odds ratio [OR], 9.3; 95% CI, 3.7-23.4) and cockroach (OR, 3.9; 95% CI, 1.3-11.6), inner-city residence (OR, 3.5; 95% CI, 1.4-8.9), asthma in family member (OR, 3.5; 95% CI, 1.4-9.0), low (<5) position in sibship (OR, 3.6; 95% CI, 1.2-11), presence of smoker in home (OR, 3.7; 95% CI, 1.2-11.9), small household size (OR, 0.57; 95% CI, 0.35-0.93), and use of electricity as domestic fuel (OR, 0.34; 95% CI, 0.12-0.97). In the multivariate analysis sensitization to mites remained the strongest risk factor associated with the asthmatic group (OR, 10.4; 95% CI, 3.5-30.9). The other significant associations were inner-city residence (OR, 4.8; 95% CI, 1.5-5.2), sensitization to cockroach (OR, 4.9; 95% CI, 1.3-18.6), and position in sibship of less than 5 (OR, 6.3; 95% CI, 1.3-29.4).

CONCLUSION

Sensitization to dust mite and cockroach allergens, inner-city residence, and low position in sibship were independent risk factors for asthma in Ghanaian children.

Pet allergen levels in homes in Ghana and the United Kingdom

The frequency of cat and/or dog ownership in Ghana is comparable to that in the United Kingdom (approximately 50%). However, in Ghanaian communities pets are predominantly kept outdoors. Levels of pet allergens (Fel d 1 and Can f 1) in 100 Ghanaian homes (49 without pets) were compared with levels in 410 homes in the United Kingdom (258 without pets). Homes with pets in the United Kingdom contained much higher allergen levels than homes with pets in Ghana (for Fel d 1: mean difference, 275-fold; 95% CI, 129-fold to 594-fold; P <.0001; for Can f 1: mean difference, 75-fold; 95% CI, 33-fold to 169-fold; P <.0001). Homes without cats in the United Kingdom contained significantly higher levels of Fel d 1 than homes with cats in Ghana (mean difference, 3.7-fold; 95% CI, 2.0-fold to 7.2-fold; P <.0001). In the United Kingdom, homes with dogs contained 75-fold (95% CI, 47-fold to 139-fold) more Can f 1 than homes without dogs, whereas in Ghana, homes with dogs contained 3.1-fold (95% CI, 1.5-fold to 6.1-fold; P =.003) more Can f 1 than homes without dogs. In the United Kingdom, homes with cats contained 77-fold more Fel d 1 (95% CI, 46-fold to 129-fold; P <.0001) than homes without cats; there was no difference in cat allergen levels between homes with cats and homes without cats in Ghana. In conclusion, levels of pet allergens in Ghanaian homes with pets were (1) between 75-fold (dog) and 275-fold (cat) lower than levels in homes with pets in the United Kingdom and (2) lower than or comparable to levels in homes without pets in the United Kingdom.

Lymphoproliferative responses in cord blood and at one year: no evidence for the effect of in utero exposure to dust mite allergens

BACKGROUND

Maternal allergen exposure beyond the 22nd week of pregnancy may be important in foetal T cell priming. Allergen-specific cord blood mononuclear cell (CBMC) immunoproliferative responses without corresponding bacterial antigen responses (tetanus toxoid), have been suggested as evidence of in utero sensitization.

OBJECTIVES

To investigate the relationship between lymphoproliferative responses at birth and at 1 year with maternal and 1-year infants house dust mite allergen exposure.

METHODS

Home visits and dust sampling were performed by the 20th week of pregnancy, immediately after birth, and then at 1 years of age. Der p 1 was assayed using a two-site immunometric ELISA. CBMC immunoproliferative responses (AIM V serum-free medium; 1 x 105 cells/well) were measured for 225 neonates (171 had a high risk of atopy (HR)--both parents skin test positive; 59 had a low risk of atopy (LR) - both parents skin test negative, no history of atopy) by 3H-Thymidine (1microCi/well) incorporation after stimulation in primary culture with phytohaemagglutinin (PHA) (1 microg/mL), house dust mite [HDM] extract (30 microg/mL), immunopurified Der p 1 (30 microg/mL), Tetanus toxoid (TT) (aluma free, 30 Lf/mL) or vehicle. Blood was collected from 144 infants at the age of 1 years and stimulated proliferative responses were assessed using the same procedure.

RESULTS

PHA-stimulated lymphoproliferative response was significantly lower in HR compared to LR neonates (mean difference 38%, 95% CI 15%-54%; P = 0.003); significantly lower proportion of positive CBMC responses to HDM occurred in LR than in HR neonates (30.4% vs. 46.6%; P = 0.034). There was no relationship between Der p 1 levels in maternal bed and CBMC immunoproliferative responses, despite the 21 000-fold range of maternal Der p 1 exposure. No significant differences in magnitude, or in proportion of positive responses to any stimulant were observed between the neonates at low, medium or high tertile of allergen exposure. Immunoproliferative responses at birth were not predictive of 1-year PBMC responses. There was no relationship between maternal allergen exposure in pregnancy and 1-year PBMC proliferative responses. However, the proportion of positive proliferative responses at 1 years significantly increased with increasing infant Der p 1 exposure at 1 years.

CONCLUSION

These results indicate that the magnitude of immunoproliferative responses are unrelated to maternal mite allergen exposure and cannot be used as evidence for in utero sensitization to inhalant allergens. The immunoproliferative responses at 1 year seem to shift away from the genetically influenced responses at birth towards responses to specific stimulants which correlate with environmental exposure to those specific stimulants. These data support the concept of sensitization to inhalant allergens occurring in early life, but not in utero.

A probabilistic learning approach to whole-genome operon prediction

We present a computational approach to predicting operons in the genomes of prokaryotic organisms. Our approach uses machine learning methods to induce predictive models for this task from a rich variety of data types including sequence data, gene expression data, and functional annotations associated with genes. We use multiple learned models that individually predict promoters, terminators and operons themselves. A key part of our approach is a dynamic programming method that uses our predictions to map every known and putative gene in a given genome into its most probable operon. We evaluate our approach using data from the E. coli K-12 genome.

Apoptosis signals in atopy and asthma measured with cDNA arrays

A variety of studies have stressed the importance of the control of inflammatory cell longevity and the balance of pro-survival and pro-apoptotic signalling. Recently, asthma was found to be associated with reduced apoptosis of inflammatory cells in lung tissue. The aim of the study was to investigate the systemic activation of apoptosis pathways using cDNA array technology in atopy and asthma. Eighteen atopic asthmatics (AA), eight atopic non-asthmatic (AN) and 14 healthy control subjects (C) were included in the study. Peripheral blood mononuclear cells were separated with gradient centrifugation, mRNA purified and the reverse-transcribed probes hybridized to cDNA arrays. The signals were compared by standardizing to the 100 most expressed genes and group differences assessed with the Mann-Whitney U-test. We found a concerted up-regulation of several pro-survival cytokines and growth factors in AN and AA. FAS and FASL were not differentially expressed, but FAST kinase was over-expressed in AN and AA. The tumour necrosis factor pathway was activated in AN and AA with increased cytokine and receptor levels and increased TRAF2, an intracellular signalling product. There were indications of a down-regulated p53 system. In contrast, the Bcl-2 family of genes showed a net pro-apoptotic profile in AN and AA. The group of caspases showed a constant gene expression pattern in all groups. In conclusion, significant differences in the expression of apoptosis-related genes were found in peripheral blood of atopic individuals with and without asthma. cDNA array technology proved to be useful and may be complementary to DNA-based studies in order to analyse interactive and multidimensional pathways as shown here for apoptosis.

Constructing biological knowledge bases by extracting information from text sources

Recently, there has been much effort in making databases for molecular biology more accessible and interoperable. However, information in text form, such as MEDLINE records, remains a greatly underutilized source of biological information. We have begun a research effort aimed at automatically mapping information from text sources into structured representations, such as knowledge bases. Our approach to this task is to use machine-learning methods to induce routines for extracting facts from text. We describe two learning methods that we have applied to this task--a statistical text classification method, and a relational learning method--and our initial experiments in learning such information-extraction routines. We also present an approach to decreasing the cost of learning information-extraction routines by learning from "weakly" labeled training data.

Manchester Asthma and Allergy Study: low-allergen environment can be achieved and maintained during pregnancy and in early life

BACKGROUND

Early exposure to dust mite allergens may be critical for primary sensitization. Reducing exposure may offer a realistic chance for primary prevention of sensitization and asthma, but it is essential to implement measures that can achieve and maintain the low-allergen environment.

OBJECTIVE

Our purpose was to assess the effectiveness of mite allergen avoidance measures in achieving and maintaining a low-allergen environment during pregnancy and in the first year of life.

METHODS

The Manchester Asthma and Allergy Study is a prospective, prenatally randomized study that follows the development of asthma and atopy in a cohort of infants at high risk (both parents atopic) who are randomly allocated to full mite allergen avoidance or to a normal regimen. Avoidance measures comprise (1) mite-proof covers (mattress, pillow, and quilt) for parental bed, (2) high-filtration vacuum cleaner, (3) vinyl flooring in infant's bedroom, (4) new crib and portable crib mattresses encased in mite-proof material, (5) benzyl benzoate (Acarosan) applied on carpets and soft furniture, (6) bed linens washed in hot water weekly, and (7) washable soft toys. Dust samples from the parental bed, bedroom floor, living room floor, infant's mattress, and nursery floor were collected between the 10th and 14th weeks of pregnancy, immediately after birth, and then at age 6 months and 1 year, and Der p 1 levels were determined by mAb-based ELISA.

RESULTS

Recovered Der p 1 from maternal mattress was reduced by 97. 25% (95% confidence interval [CI] 95.25%-98.41%) during the second and third trimesters of pregnancy, with the effect persisting for 6 months (98% reduction, 95% CI 97.25%-99.1%) and 12 months (97.6% reduction, 95% CI 95.7%-98.6%) after the birth (active vs control, P <.000001). Total Der p 1 from bedroom floor in the active group was reduced by 53.7% (95% CI 25.7%-71.2%) in samples collected within 4 weeks of the child's birth, with the percentage reduction being 62. 8% (95% CI 39.3%-77.2%) at 6 months and 26.5% (95% CI -24% to 57.1%) at 1 year (active compared vs control, P <.007). Der p 1 levels in crib mattress and nursery floor in the active group were extremely low (crib mattresses geometric mean [95% CI] 2.3 ng [1.6-3.4] at birth, 6.8 ng [4.5-10] at age 6 months, and 15.6 ng [9.8-24.8] at age 1 year [active vs control, P =.001]; nursery 1 ng [0.9-1.1] at birth, 1.7 ng [1.2-2.5] at age 6 months, and 2 ng [1.3-3.5] at age 1 year [active vs control, P <.00001]). The total amount of allergen recovered at age 1 year was 29-fold (95% CI 15.1- to 56.7-fold) higher in the control group than in the active group.

CONCLUSIONS

The avoidance measures used in this study achieved and maintained a low mite allergen environment during pregnancy and in the first year of life in homes of infants at risk of atopy.

Dust mite allergens are carried on not only large particles

The major obstacle for the successful measurement of airborne mite allergen is its very low concentration in the absence of vigorous disturbance. The aim of this study was to investigate the particle size distribution of group 2 dust mite allergen using an amplified ELISA system. Air sampling was performed using an Andersen sampler placed in the centre of the room, 1.2 m above floor level (airflow rate 28.7 l/min). This is a multistage, multiorifice cascade impactor that is comprised of six stages. Any particle greater that 4.7 microm should impact on stages 1 and 2, whilst stages 3-6 measure the predominantly respiratory range. The sampling was carried out for 30 min after 15 min of vigorous disturbance (vacuum cleaning without bag and filter). Der p 2 was measured using mAb-based ELISA with the AmpliQ amplification kit (Dako Ltd, Cambridgeshire, UK). The sensitivity was increased 15-fold as compared with standard assay, bringing the level of detection to 300 pg/ml. The majority of airborne Der p 2 (79.4%) was carried on large particles (> 4.7 microm). However, a small but important proportion of airborne Der p 2 (20.6%) was associated with small particles (1.1-4.7 microm). It is worth noting that all the levels measured were below the detection limit of standard assay. In conclusion, we have shown that using an amplification system, airborne mite allergen previously undetectable owing to its low concentration can be quantified. Group 2 dust mite allergen is carried not only on large particles. A small, but potentially significant proportion of this airborne allergen is associated with small particles which, when inhaled, may penetrate deep into the human respiratory tract.

A comprehensive approach to the management of male infertility following spinal cord injury

OBJECTIVES

To review the outcomes of management of male infertility following spinal cord injury in a specialised fertility clinic.

STUDY DESIGN

Retrospective review of medical records.

SETTING

The Fertility Clinic of a 45-bed spinal cord injury service in New South Wales, Australia.

METHODS

The medical and fertility clinic records of 113 males who attended the clinic between 1987 and 1997 were reviewed.

RESULTS

The rates of semen retrieval using vibroejaculation and electroejaculation were 67% and 97% respectively. Thirty-one individuals (37%) and their partners sought assistance with the primary aim of achieving a pregnancy. Intravaginal insemination (IVI) undertaken at home following vibroejaculation resulted in a pregnancy rate per cycle of 22%. Electroejaculation and IVI proved less successful with a pregnancy rate per cycle of only 5%, although with intrauterine insemination (IUI) this rate improved to 30%. Micromanipulation in vitro fertilisation (IVF) procedures, primarily intracytoplasmic sperm injection, were used in 18 couples resulting in a pregnancy rate per cycle of 19%. In the 31 couples there have been a total of 17 pregnancies in 97 cycle attempts for an overall pregnancy rate per cycle of 18% and a cumulative pregnancy rate per couple of 55%. Twelve of the pregnancies have resulted in 14 live births (including two sets of twins), there were three pregnancies ongoing at the date of review and there have been two spontaneous abortions.

CONCLUSION

The benefits of a specialised fertility clinic offering a comprehensive, client-focused approach with education, fertility assessment and a range of semen retrieval and assisted reproduction options, are highlighted.

Relationship between mite, cat, and dog allergens in reservoir dust and ambient air

BACKGROUND

Standardized methods to measure allergen exposure are essential to assess the relationship between exposure, sensitization, and asthma. Most studies have measured allergen levels in reservoir dust, although air samples may be more representative as a measure of inhaled allergen. The aim of this study was to define the relationship between mite, cat, and dog allergen content in the reservoir dust and the levels in the ambient air.

METHODS

Dust samples from the living-room floor (LF) and sofa (S) were collected in 127 homes: 62 without and 65 with pets (31 dogs, 34 cats). Air samples were taken in the same room, with a high-volume pump for 1 h (flow 60 l/min). Der p 1, Fel d 1, and Can f 1 were determined by mAb-based ELISA.

RESULTS

Airborne Der p 1 was below the detection limit (0.8 ng/m3) in all homes, with reservoir levels (GM and range) being 1.14 microg/g (0.2-66) and 1.15 microg/g (0.2-127) in LF and S, respectively. Airborne Can f 1 was detected in 40/62 homes without pets (range 0.6-12.4 ng/m3) and in all homes with dogs (range 0.5-99 ng/m3). In the multiple linear regression analysis, Can f 1 level in the LF was an independent correlate of the airborne Can f 1 (P=0.01, homes with dogs; P=0.04, homes without dogs). Fel d 1 was detected in the air in 16/62 homes without pets (range 0.16-1.8 ng/m3) and in all homes with cats (range 0.4-22.3 ng/m3). Fel d 1 level in the LF was an independent correlate of the airborne Fel d 1 in homes without cats (P=0.008), but airborne levels in homes with cats did not correlate with reservoir levels.

CONCLUSIONS

The aerodynamics of each allergen must be taken into account when assessing exposure: while levels in reservoir dust are the best available index for mite allergens, airborne levels might be more suitable for defining exposure to pets. If air samples are difficult to obtain, levels of Can f 1 and Fel d 1 in the LF samples should be used as a surrogate measure of personal exposure.

Mental health services in the family physician's office: a Canadian experiment

This paper describes a program in Hamilton-Wentworth, Ontario, Canada, that brings mental health counselors and psychiatrists into the offices of 87 local family physicians, working in 35 practices serving 170,000 people. It outlines the organization of the mental health teams in the family physician's office and the way in which these teams are coordinated and discusses how this "shared care" approach can overcome many of the problems that traditionally bedevil the relationship between psychiatric services and family practices. It summarizes the benefits of this approach for patients providers and the health care system and looks at its implications for learners and for new approaches to continuing education. This model can be adapted to most communities.

Mortality following spinal cord injury

This study analyzed the mortality in 1453 spinal cord injured patients admitted early after injury to a specialised Spinal Injuries Unit within a University teaching hospital over a 40-year period. The cohort comprised 55.3% patients with cervical lesions and 44.7% patients with thoracic/lumbar lesions. Those patients who died within 18 months of the spinal injury (132) were excluded from the final analysis. Standardised Mortality Ratios, survival rates and life expectancy ratios were calculated for specific ranges of current attained age and duration since injury with reference to level and degree of spinal cord injury. The projected mean life expectancy of spinal cord injured people compared to that of the whole population was then estimated to approach 70% of normal for individuals with complete tetraplegia and 84% of normal for complete paraplegia (Frankel grade A). Patients with an incomplete lesion and motor functional capabilities (Frankel grade D) are projected to have a life expectancy of at least 92% of the normal population.

Integrating mental health services within primary care. A Canadian program

The increasingly prominent role of the family physician in delivering mental health care can be enhanced if productive and collaborative relationships can be established with local mental health services. This paper describes a Canadian program that has achieved this by bringing mental health counselors and psychiatrists into the offices of 87 family physicians in 35 practices in a community in Southern Ontario. The paper describes the program, the activities of counselors and psychiatrists within the practices, and the administrative structures set up to coordinate these activities. Data is presented from the evaluation of the first year of the program's operation (13 practices and 45 family physicians) during which time 3085 referrals were received. The program made mental health care more available and accessible, increased continuity of care, provided additional support for the family physician, offered new opportunities for continuing education, and led to a reduced and more efficient use of other mental health services. The components of the program can be adapted to most communities.

An integrated regional emergency psychiatry service

This paper presents a model of an integrated Psychiatric Emergency Service serving Hamilton, a community of 450,000 in Southern Ontario. It describes the evolution of the service and how it has integrated five separate, hospital-run Emergency Psychiatric Services into a single service. The principles of the service and ways in which it operates are outlined and the advantages and drawbacks of the model are discussed. The authors conclude that such a model leads to a more efficient use of resources and is adaptable to most urban communities with a similar, or even larger population.

Case reviews in the family physician's office

The majority of patients with emotional or psychiatric disorders are treated in the primary care setting without psychiatric input. Psychiatrists need to find ways of helping family physicians manage these patients without necessarily taking over their care. One way of achieving this is for a psychiatric consultant to visit the family physician's office on a regular basis to discuss the physician's problem cases. This paper describes such a pilot project, outlines the kinds of problems family physicians discussed and recommendations that were made, and discusses the benefits of this collaborative approach.

The surgical treatment of childhood moyamoya disease

Moyamoya disease is a progressive disorder, predominantly seen in childhood, that can cause severe permanent disability. The search for effective treatment has largely been unsuccessful in the past, but recent efforts at surgical intervention have shown promising results. The natural history of moyamoya disease, the options for treatment, and a series of patients from the Hospital for Sick Children in Toronto are reviewed. The results of surgical treatment are encouraging and the authors believe that it should be offered to all pediatric patients in the progressive stage of the disease.

Teaching core content in family medicine

Core content in family medicine has been difficult to define, given that family practice has differed widely from physician to physician, according to locale and availability of resources. Since family medicine has been taught, educators have been attempting to define its core content-and find ways of teaching it. At the McMaster University Medical Centre Family Practice Unit we have put the problems first: residents present a problem in patient care and the group discusses the problem in relation to a precirculated article on the topic. Lecturing is kept to a minimum, and articles are chosen according to the principles of critical appraisal. An attempt at evaluation generated a positive response.