Characterization of a murine model of intranasal infection suitable for testing vaccines against C. abortus

Mouse models have been widely used to test candidate vaccines against Chlamydophila abortus infection in mice. Although the induction of a systemic infection by endogenous or intraperitoneal inoculation is a useful tool for understanding the immune mechanism involved in the protection conferred by the vaccination, a different approach is necessary to understand other factors of the infection, such as mucosal immunity or the colonization of target organs. To test whether C. abortus intranasal model of infection in mice is a useful tool for testing vaccines in a first group of experiments mice, were infected intranasally with C. abortus to characterize the model of infection. When this model was used to test vaccines, two inactivated experimental vaccines, one of them adjuvated with QS-21 and another with aluminium hydroxide, and a live attenuated vaccine (strain 1B) were used. Non-vaccinated control mice died within the first 8 days, after displaying substantial loss of weight. Histologically, the mice showed lobar fibrinopurulent bronchointerstitial pneumonia. Prior immunization with QS-21 adjuvated vaccine or 1B vaccine presented mortality and the recipients showed a greater number of T cells in the lesions, especially CD8(+) T cells, than the control mice and mice immunized with vaccine adjuvated with aluminium hydroxide. The results confirm that the C. abortus intranasal model of infection in mice is a useful tool for testing vaccines.

Test characteristics from latent-class models of the California Mastitis Test

We evaluated (using latent-class models) the ability of the California Mastitis Test (CMT) to identify cows with intramammary infections on the day of dry-off. The positive and negative predictive values of this test to identify cows requiring dry-cow antibiotics (i.e. infected) was also assessed. We used 752 Holstein-Friesian cows from 11 herds for this investigation. Milk samples were collected for bacteriology, and the CMT was performed cow-side, prior to milking on the day of dry-off. At the cow-level, the sensitivity and specificity of the CMT (using the four quarter results interpreted in parallel) for identifying all pathogens were estimated at 70 and 48%, respectively. If only major pathogens were considered the sensitivity of the CMT increased to 86%. The negative predictive value of the CMT was >95% for herds with major-pathogen intramammary-infection prevalence <15%, so that selective dry-cow therapy might be reasonable for such herds if cows were screened with the CMT.

Seroprevalence of and risk factors for HIV-1 infection among female commercial sex workers in South America

OBJECTIVE

Assessment of HIV prevalence and associated risk behaviours among female commercial sex workers (FCSW) across major cities in South America.

METHODS

Seroepidemiological, cross sectional studies of 13 600 FCSW were conducted in nine countries of South America during the years 1999-2002. Participants were recruited in brothels, massage parlours, hotels, and streets where anonymous questionnaires and blood samples were collected. HIV infection was determined by enzyme linked immunosorbent assay (ELISA) screening and western blot confirmatory tests.

RESULTS

The overall HIV seroprevalence was 1.2% (range 0.0%-4.5%). The highest HIV seroprevalences were reported in Argentina (4.5%) and Paraguay (2.6%); no HIV infected FCSW were detected in Venezuela and Chile. Consistent predictors of HIV seropositivity were: (1) a previous history of sexually transmitted infections (STI, AORs = 3.8-8.3), and (2) 10 years or more in commercial sex work (AORs = 2.2-24.8). In addition, multiple (> or =3) sexual contacts (AOR = 5.0), sex with foreigners (AOR = 6.9), use of illegal drugs (AOR = 3.2), and marijuana use (AOR = 8.2) were associated with HIV seropositivity in Southern Cone countries.

CONCLUSIONS

Consistently low HIV seroprevalences were detected among FCSW in South America, particularly in the Andean region. Predictors of HIV infection across the continent were STI and length of commercial sex work; however, use of illegal drugs, especially marijuana, and sexual contacts with foreigners were also found to be associated risk factors in the Southern Cone region. Interventions for the control of HIV and other STI need to be region and country specific; drug use appears to have an ever increasing role in the spread of HIV among heterosexually active populations.

Effect of eprinomectin pour-on treatment around calving on reproduction parameters in adult dairy cows with limited outdoor exposure

The objective of this study was to investigate if treatment of cows with eprinomectin around calving had any beneficial effects on the calving to first artificial insemination interval, calving to conception interval, and number of services per conception in totally- and semi-confined dairy herds. In totally-confined herds lactating- and dry-cows were housed throughout the summer and had no access to pasture. In semi-confined herds lactating- and dry-cows had limited outdoor exposure to a small pasture or paddock but were still fed a ration that met all their nutritional requirements. The study was carried out between February 2002 and February 2003 in 35 herds (2381 cows) located in Quebec, Ontario and Minnesota (USA) participating in a larger clinical trial. The herds kept electronic reproduction records. Cows were randomly allocated to receive eprinomectin or a placebo, with treatment being administered on or close to the day of calving. Monthly bulk tank milk samples from each farm were tested with an indirect ELISA using a crude Ostertagia ostertagi antigen and these data were averaged over the study year. The optical density ratio (ODR) values were then dichotomized into high and low using a cut-point of 0.50. Treatment effects were analyzed using Cox proportional hazards survival models with herd frailty effects for calving to conception and calving to first service intervals. Aalen's linear hazards model was used to investigate time-varying effects in the Cox models. A random effects poisson regression model was used to model the number of services per conception. Other predictor variables tested in the models were lactation number, calving season, study site, peak milk production, ODR and the lactating- and dry-cow housing variables. Overall, there was no significant effect of treatment on the three indices of reproductive performance. The effect of season of calving depended on how much time had passed since calving. Presumably this effect reflected a seasonal effect at the time of breeding. Hazard of conception in younger cows was higher than in older cows. Early bred cows tended to have a higher number of inseminations per conception than those bred late. The results of the study suggested that eprinomectin treatment at calving was not beneficial to reproduction.

Clinical outcome of gemcitabine (gem)/cisplatin (cis)- vs docetaxel (doc)/cis-treated stage IV non-small cell lung cancer (NSCLC) patients (p) according to X-ray repair cross-complementing group 3 (XRCC3) polymorphism and age

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Background: Significant interaction between XRCC1 genotype and age has been reported, with younger subjects having a greater risk of developing lung cancer. Carriers of XRCC3 241 MetMet have higher levels of DNA adducts, leading us to hypothesize that they would be more chemosensitive, especially younger patients. Methods: Real-time PCR assay was used to determine XRCC3 genotype from DNA isolated from baseline blood samples of 878 stage IV NSCLC p (162 treated with gem/cis; 716 with doc/cis). Median age, 60; 266 p (30%) <55; 239 p (39%) 55–66; 273 p (31%) >66. Adenocarcinoma: 459 p (53%). Homozygous variant XRCC3 241 MetMet was found in 124 p (14%), with the same frequency in each of the three age groups. Results: After a median follow-up of 7.6 months (m) (95% CI, 1–47 m), overall median survival (MS) was 9.5 m (95% CI, 8.8–10.2 m), with no differences between the 2 regimens. In all p with XRCC3 241 MetMet, MS was 12.9 m for p treated with gem/cis and 8.4 m for p treated with doc/cis (P = 0.06) (hazard ratio at 2 y = 0.23). In p with XRCC3 241 MetMet <55 y, MS was not reached for p treated with gem/cis and 9.2 m for p treated with doc/cis (P = 0.02), which translated into a 60% difference in survival at 2 y. This difference diminished in p with XRCC3 241 MetMet 55–66 y (MS 12.9 m with gem/cis, 6.9 m with doc/cis [P = 0.09]; 28% difference in survival at 2 y) and disappeared in p >66 y (MS 5.8 m with gem/cis, 7.8 m with doc/cis [P = 0.55]. For the other XRCC3 241 genotypes (ThrThr and ThrMet), no differences in MS were found either overall or broken down by age. Conclusions: XRCC3 241 MetMet is both an easily assessable and robust predictive marker for survival in younger gem/cis-treated NSCLC p. The survival benefit dwindles with increasing age, possibly related to the enhanced DNA repair capacity of older p.

No significant financial relationships to disclose.

Excision cross-complementing group 1 (ERCC1) single nucleotide polymorphisms (SNPs) and survival in cisplatin (cis)/docetaxel (doc)-treated stage IV non-small cell lung cancer (NSCLC) patients (p): A Spanish Lung Cancer Group study

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Background: SNPs are the result of historical errors in DNA replication or repair that have been inherited through generations and are now shared among individuals. ERCC1 belongs to the nucleotide excision repair pathway. We examined whether ERCC1 SNPs 118 C/T and C8092A affect the repair of cis DNA lesions and thereby influence survival in cis-treated NSCLC p. Methods: SNP genotyping of ERCC1 118C/T and C8092A was performed by the TaqMan assay, and results were correlated with median survival (MS) in 706 cis/doc-treated stage IV NSCLC p. Results: Characteristics: 590 male, 116 female; performance status (PS) 0: 216 p (30.6%), PS 1: 480 p (68%), PS 2: 10 p (1.4%); adenocarcinoma, 371 p (53%). Overall response rate: 30%. After a median follow-up of 7.8 months (m) (range, 1–47 m), overall MS was 8.9 m. SNP frequencies: 118 T/T, 40.2%; C/T, 45.4%; C/C, 14.4%; C8092A C/C, 57.6%; C/A, 36%; A/A, 6.4%. MS according to 118 C/T SNP: T/T, 8.9 m; C/T, 9.5 m; C/C, 10 m (P = 0.51). MS according to C8092A SNP: C/C, 9.3 m; C/A, 10.2 m; A/A, 7.2 m (P = 0.05). When stratified by PS, the association between C8092A and MS is stronger for p with PS 0: C/C, 15.9 m; C/A, 13.8 m; A/A, 8.7 m (P = 0.04). Conclusions: This is the largest study to date reporting the effect of ERCC1 C8092A SNP on MS in stage IV NSCLC p treated with a single regimen. The uncommon A/A genotype predicts poor survival in p treated with dis/doc.

No significant financial relationships to disclose.

Mitotic checkpoint gene CHFR methylation in pretreatment serum DNA of docetaxel (doc)/cisplatin (cis)-treated stage IV non-small cell lung cancer (NSCLC) patients (p)

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Background: CHFR (checkpoint with forkhead-associated and ring finger) regulates a prophase delay in cells exposed to agents that disrupt microtubules. Epigenetic inactivation of CHFR is a frequent event in human tumors, leading to impaired checkpoint function and enhanced sensitivity to docetaxel. We hypothesized that serum DNA methylation of CHFR could be a predictor of longer survival in p treated with doc/cis. Methods: Sodium bisulfite modified serum DNAwas used as the template for methylation-specific PCR assay. DNA was obtained from 600 doc/cis-treated stage IV NSCLC p. Results: Preliminary data on 301 p is available. The frequency of CHFR hypermethylation was 32.6%. There was no association between methylation and performance status (PS), age, gender, histology, response, 14–3-3σ serum DNA methylation, polymorphisms in lymphocyte DNA (ERCC1 118 C/T, ERCC1 C8092A, XRCC3 241 ThrMet), or tumor ERCC1 mRNA levels. Overall, there was a tendency to better median survival (MS) for p with methylated CHFR. In p with PS 0, MS was 33 months (m) for 41 p with methylated CHFR and 12 m for 64 p with unmethylated CHFR (P = 0.23). In p >66 years (y), MS was not reached for 31 p with methylated CHFR and 9.6 m for 80 p with unmethylated CHFR (P = 0.01), while in p <66 y, MS was 9.4 m for 67 p with methylated CHFR and 10 m for 123 p with unmethylated CHFR (P = 0.62). p with both 14–3-3σ and CHFR methylation showed a tendency to longer survival. Final data on 600 p will be presented. Conclusions: Early findings indicate that CHFR methylation in elderly p predicts a significant survival benefit in doc/cis-treated NSCLC.

No significant financial relationships to disclose.

Chemotherapy-induced neutropenia and treatment efficacy in advanced non-small cell lung cancer: An analysis of the Spanish Lung Cancer Group pharmacogenomic study of cisplatin and docetaxel combination (PLATAX)

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Background: Chemotherapy is the standard treatment for advanced non-small-cell lung cancer, and myelosuppression is a common side-effect. We aimed to assess whether haematological toxic effects could be a biological measure of drug activity and a marker of efficacy. Methods: We analysed data of 493 patients who received chemotherapy (cisplatin and docetaxel) within the pharmacogenomic, open-label, single-arm, multicentric PLATAX trial. Three subgroups of patients were considered: global population, patients who received at least three cycles of chemotherapy, and those who received at least six cycles. Neutropenia was categorised on the basis of worst WHO grade during chemotherapy: absent (grade 0), mild (grade 1–2), or severe (grade 3–4). Relative dose intensity was analysed for both drugs. The primary endpoint was overall survival. Results: Median overall survival was 9 months (8.2–9.7). Median relative dose intensity was 0.97 for cisplatin and docetaxel. 403 patients received at least three cycles of chemotherapy, and 255 received six or more. Neutropenia appeared in 172 patients (30.8%), 72 of them G3–4 (18.6%). Dose intensity was lower in patients who presented any grade of neutropenia versus those without neutropenia in the three analyzed subgroups, for both drugs (p < 0.05). Factors associated with higher risk of death were ECOG 1–2 (HR 1.8, p = 0.00) and female (HR 1.5, p = 0.02). There were no differences in overall survival between patients with G0 vs G1–2 vs G3–4 neutropenia (8.7 vs 11.6 vs 9.6 m, p = 0.41), however the risk of death was lower in patients with ECOG 0, that presented neutropenia (HR: 0.545, IC 95%: 0.31, 0.96; p = 0.034). Conclusions: Neutropenia during chemotherapy may be associated with increased survival of patients with advanced non-small cell lung cancer and ECOG 0. Its absence is not a result of underdosing. Prospective trials are needed to assess whether neutropenia could be a biological measure of drug activity and a marker of efficacy.

No significant financial relationships to disclose.

Geographical and temporal aspects of an outbreak of off-flavours in bulk-tank milk in Prince Edward Island, Canada

The geographical and temporal dynamics of the outbreak of off-flavours in bulk-tank milk that occurred between September 2000 and June 2002 in Prince Edward Island (PEI) dairy herds were described using spatial, temporal and space-time scan statistics. Results suggested clustering both in time and space. We found one primary cluster (six case herds, feed off-flavour, October 2000 to January 2001) and two secondary clusters formed of feed (5 case herds, October 2000 to January 2001)) and rancid (five case herds, December 2000 to March 2001) off-flavours, respectively. The relative risk (RR) for producing off-flavoured milk was similar for these three clusters (RR=6.4).

Temporal and spatial analysis of the 1999 outbreak of acute clinical infectious bursal disease in broiler flocks in Denmark

The objective of this study was to describe the spatial and temporal dynamics of the 1999 outbreak of acute clinical infectious bursal disease (IBD) in broiler chicken farms in Denmark. The analysis was performed using data from all broiler farms located in the Jutland peninsula and the island of Funen (168 municipalities). The Moran's index I, K-functions and scan statistics were used to describe the dynamics of the epidemic. In addition, spatially correlated survival analyses were performed and the posterior frailties were mapped to identify areas with high or low survival times. From January to October 1999, a total of 43 farms (81 flocks) out of a total of 299 farms (2970 flocks) in 110 municipalities were infected with IBD. The outbreak developed more or less simultaneously in two regions, one in the north and the other in the center of the study area. The space-time descriptive methods suggested that the cases were more likely to occur during a short period of time and over relatively short distances, indicating that local factors facilitated the spread of the virus. For instance, the highest risk, as estimated by the K-function, was within 20 km and 20 days. The risk of transmission peaked in July and remained high until the end of the study. The spatially correlated survival analysis identified municipalities with low survival times that roughly corresponded to the clusters found using scan statistics. The analysis for the full hierarchical structure of the dataset identified variation (i.e. clustering) at the farm and municipality levels.

Prévalence des déficiences et disparités sociales

BACKGROUND

Population ageing and longer duration of the working career could increase the prevalence of impairments and disabilities whereas there have been few data to help prevention and care. This study aimed at describing the prevalence of various types of impairments and assessing their social inequalities in the Lorraine population (north-eastern France).

METHODS

The sample included 6.214 subjects aged 15 or more from 8.000 households randomly selected in the Lorraine population. A mailed questionnaire including socio-demographical characteristics, job, and various types of impairments was used. The data were analysed with the chi2 independence test, the adjusted odds ratio (OR) and the Mantel-Haenszel test.

RESULTS

The prevalence of at least one impairment was 30% in both sexes. It varied from about 20% for subjects aged less than 40 years to about 60% for the subjects aged 70 years or more. It was higher in men than in women among the individuals aged more than 50 years (OR adjusted on age: 1.22, 95% CI: 1.04-1.44). The impairments were generally multiple for the subjects aged over 50. The prevalence of at least one impairment was higher for workmen (OR adjusted on age: 2.11, 95% CI: 1.68-2.66), farmers, craftsmen, traders and heads of firms (OR adjusted on age: 1.60, 95% CI: 1.17-2.18) and for employees (OR adjusted on age: 1.62, 95% CI: 1.29-2.03) in comparison with executives, intellectual professionals and teachers. For workmen a higher prevalence was observed for all types of impairments: intellectual and psychological functions, language, hearing, vision, visceral functions, and skeleton and posture. Farmers, craftsmen, traders, heads of firms and employees showed an excess for most types of impairments. Social inequalities were significant for various age groups during their period of occupational activity, but not after retirement. Unemployed people also had an excess of impairments.

CONCLUSION

The prevalence of impairments strongly increased with advancing age. Marked inequalities were observed between various socio-occupational categories. Men were more affected than the women over 50 years of age. Impairments represent a health index which is useful for prevention to reduce their causes and consequences.

Assessing the agreement between Ostertagia ostertagi ELISA tests performed using the crude adult antigen and the adult and larval stage 4 excretory/secretory antigens

The objective of this study was to determine the agreement between ELISA tests conducted using three O. ostertagia antigens: crude adult worm, larval stage 4 (L4) excretory/secretory (ES) and adult ES. This study was carried out on 289 Holstein cows from five herds in Prince Edward Island and one herd in Nova Scotia. Composite milk samples of these cows were collected (between May and September 2002) from the respective provincial laboratories and sent to the Atlantic Veterinary College where each sample was tested for antibodies to O. Ostertagi using an indirect microtitre ELISA test. Results were expressed as optical density ratio (ODR) values. Each milk sample was tested with three ELISA tests, with each test using a different O. ostertagi antigen. There was a slight rise in ODR values of both adult antigens, between May and August, with higher values obtained using the adult ES antigen. L4 ES ODR values were generally higher than those for both adult antigens during the study period, except for May. There was a more dramatic rise in L4 ES ODR values between May and August. Rises in ODR in May and end of July coincided with periods of mass maturation of L4 to adult worms. The results of the study showed that the concordance correlation coefficient (CCC) between tests performed using both ES and the crude antigens were low (crude adult versus adult ES=0.31, crude adult versus L4 ES=0.30). The highest CCC was observed between tests done using both ES antigens (CCC=0.56). Generally, the study results suggest that the antibody response (detectable by the ELISA) is mainly directed against ES antigens (especially L4) than the crude adult worm antigen.

The S-phase fraction of the aneuploid cell subpopulation is the biologically relevant one in aneuploid breast cancers

BACKGROUND

In the case of DNA-aneuploid tumors there are no clear guidelines as to which S-phase fraction is the more relevant one: that corresponding to either the diploid or the aneuploid population, or rather an average of both.

MATERIALS AND METHODS

We studied 280 breast cancer specimens from previously untreated patients. Histologically, 231 were ductal infiltrating carcinomas, 30 lobular infiltrating carcinomas and 19 corresponded to other, less frequent varieties. Postsurgically, 164 cases (58.6%) were classified as T1, 87 (31.1%) as T2 and 7 as T3. The remaining 22 cases were multifocal, diffuse tumors. Flow cytometry was performed on fresh tumor tissue, and immunohistochemistry for hormone receptors, Ki67, c-erb-B2 and p53 on paraffin-embedded material.

RESULTS

In diploid tumors, a high S-phase (above the 75th percentile) correlated significantly with Ki67 expression > or =20% (p<0.0001). In aneuploid tumors, however, this was only the case for the aneuploid fraction of tumor cells (p< 0.0001). A high S-phase of diploid tumors correlated directly and significantly with a high histologic grade (p=0.04), a high nuclear grade (p=0.01), tumor size (p=0.0008), and inversely with estrogen (p<0.0001) and progesterone (p<0.0001) receptor expression. In aneuploid tumors, the aneuploid tumor fraction showed a direct and significant correlation with a high histologic grade (p=0.005), a high nuclear grade (p=0.001), mutant p53 expression (p=0.0009), and inversely with estrogen (p<0.0001) and progesterone (p=0.0001) receptor expression. A high S-phase of the diploid cell fraction of aneuploid tumors, on the other hand, just showed an inverse correlation with high nuclear grade of the tumors (p=0.02), and none whatsoever with all other tested parameters.

Effect of Eprinomectin Treatment at Calving on Milk Production in Dairy Herds with Limited Outdoor Exposure

The objective of this study was to determine the effect of anthelmintic treatment at calving in herds that were totally or semiconfined during the summer. In totally confined herds, lactating and dry cows were housed throughout the summer and had no access to pasture. In semiconfined herds, lactating and dry cows had limited outdoor exposure to a small pasture or paddock but were still fed a ration that met all their nutritional requirements. The study was carried out between February 2002 and February 2003 in 65 herds enrolled with DHI and distributed in 4 regions in Canada and 1 state in the United States. Cows were randomly allocated to receive eprinomectin or a placebo, with treatment being administered on or close to day of calving. In May and June 2002, 8 fecal samples were collected from each farm and fecal egg counts (FEC) were determined. Monthly bulk tank milk samples from each farm were tested with an indirect ELISA using a crude Ostertagia ostertagi antigen. Monthly test-day milk production data were recorded for 200 d after calving. In general, FEC were very low (mean = 1 egg per gram, range = 0 to 27). Mean herd bulk milk ELISA optical density ratio (ODR) values for the whole year ranged between 0.22 and 0.80. The ODR values were dichotomized into high and low using a threshold of 0.5. Treatment effects were analyzed using a linear mixed model with herd and cow as random effects. The analysis was restricted to 4789 cows (23,956 test-day records) treated between 21 d before and 7 d after calving. Overall, there was no significant effect of treatment. However, there was a tendency for an interaction between treatment and ODR, as illustrated by a larger numerical difference in treated vs. untreated cows in high-ODR herds than in low-ODR herds. However, the confidence intervals for the treatment effects (kg/d of milk per cow) in high-ODR herds (-0.33 to 1.10) and in low-ODR herds (-0.53 to 0.14) were wide and included zero. Therefore, this study failed to show a beneficial effect of eprinomectin treatment in these totally or semiconfined herds.