Meningococcal carriage prevalence in university students, 1824 years of age in Santiago, Chile

INTRODUCTION

Neisseria meningitidis invasive disease is a major public health problem. Pharyngeal carriage is considered a prerequisite for invasive infection. Prevalence reaches 10% in general population and up to 30% in the 20-24 years age group. The aim of this study was to asses pharyngeal carriage prevalence in healthy subjects aged 18-24 years, and as secondary endpoints evaluate known risk factors, to identify serogroups and sequence in the isolated strains.

METHODS

Cross-sectional study in 500 healthy subjects; students from Universidad de Chile aged 18-24 years, Santiago, Chile, October 2012. Each subject underwent a risk factor survey prior to throat culture sampling. Samples were processed in one central Microbiology Laboratory of Hospital Luis Calvo Mackenna and serogrouping and sequencing was performed at Instituto de Salud Pública de Chile.

RESULTS

We obtained throat samples from 500 healthy subjects, 20 (4%) positive for N. meningitidis. Of positive strains 20% were serogroup B, 15% W and the rest non groupable. The median age was 20 years, 50% were men. Of the risk factors evaluated, 24% were current smokers, 16% shared a room, 72% had kissed someone during the last month, 64% had gone to pub and 76% had consumed alcohol in the same period of time.

DISCUSSION

Literatures meningococcal carriage prevalence reaches up to 30% in people aged 18-24 years. Prevalence in our study was 4%. Different interpretations could be given; one could be the absence of overcrowding in our students because of the lack of dorms in our scholar system and also the characteristics of our enrolled group.

CONCLUSIONS

Our results suggest the necessity to extend the study to other age groups and to other cities, to better understand the Chilean reality, as well as others regions of America, considering that these results cannot be extrapolated to another countries.

Vaccination against δ-retroviruses: the bovine leukemia virus paradigm

Bovine leukemia virus (BLV) and human T-lymphotropic virus type 1 (HTLV-1) are closely related δ-retroviruses that induce hematological diseases. HTLV-1 infects about 15 million people worldwide, mainly in subtropical areas. HTLV-1 induces a wide spectrum of diseases (e.g., HTLV-associated myelopathy/tropical spastic paraparesis) and leukemia/lymphoma (adult T-cell leukemia). Bovine leukemia virus is a major pathogen of cattle, causing important economic losses due to a reduction in production, export limitations and lymphoma-associated death. In the absence of satisfactory treatment for these diseases and besides the prevention of transmission, the best option to reduce the prevalence of δ-retroviruses is vaccination. Here, we provide an overview of the different vaccination strategies in the BLV model and outline key parameters required for vaccine efficacy.

Microstructural differences in the thalamus and thalamic radiations in the congenitally deaf

There is evidence of both crossmodal and intermodal plasticity in the deaf brain. Here, we investigated whether sub-cortical plasticity, specifically of the thalamus, contributed to this reorganisation. We contrasted diffusion weighted magnetic resonance imaging data from 13 congenitally deaf and 13 hearing participants, all of whom had learnt British Sign Language after 10 years of age. Connectivity based segmentation of the thalamus revealed changes to mean and radial diffusivity in occipital and frontal regions, which may be linked to enhanced peripheral visual acuity, and differences in how visual attention is deployed in the deaf group. Using probabilistic tractography, tracts were traced between the thalamus and its cortical targets, and microstructural measurements were extracted from these tracts. Group differences were found in microstructural measurements of occipital, frontal, somatosensory, motor and parietal thalamo-cortical tracts. Our findings suggest that there is sub-cortical plasticity in the deaf brain, and that white matter alterations can be found throughout the deaf brain, rather than being restricted to, or focussed in the auditory cortex.

Dynamics of perinatal bovine leukemia virus infection

Background

Bovine leukemia virus (BLV) is highly endemic in many countries, including Argentina. As prevention of the spread from infected animals is of primary importance in breaking the cycle of BLV transmission, it is important to know the pathophysiology of BLV infection in young animals, as they are the main source of animal movement. In this work, we determined the proviral load and antibody titers of infected newborn calves from birth to first parturition (36 months).

Results

All calves under study were born to infected dams with high proviral load (PVL) in blood and high antibody titers and detectable provirus in the colostrum. The PVL for five out of seven calves was low at birth. All animals reached PVLs of more than 1% infected peripheral blood mononuclear cells (PBMCs), three at 3 months, one at 6 months, and one at 12 months. High PVLs persisted until the end of the study, and, in two animals, exceeded one BLV copy per cell. Two other calves maintained a high PVL from birth until the end of the study. Antibody titers were 32 or higher in the first sample from six out of seven calves. These decayed at 3–6 months to 16 or lower, and then increased again after this point.

Conclusions

Calves infected during the first week of life could play an active role in early propagation of BLV to susceptible animals, since their PVL raised up during the first 12 months and persist as high for years. Early elimination could help to prevent transmission to young susceptible animals and to their own offspring. To our knowledge, this is the first study of the kinetics of BLV proviral load and antibody titers in newborn infected calves.

Selection of process conditions by risk assessment for apple juice pasteurization by UV-heat treatments at moderate temperatures

The effect of bactericidal UV-C treatments (254 nm) on Escherichia coli O157:H7 suspended in apple juice increased synergistically with temperature up to a threshold value. The optimum UV-C treatment temperature was 55 °C, yielding a 58.9% synergistic lethal effect. Under these treatment conditions, the UV-heat (UV-H55 °C) lethal variability achieving 5-log reductions had a logistic distribution (α = 37.92, β = 1.10). Using this distribution, UV-H55 °C doses to achieve the required juice safety goal with 95, 99, and 99.9% confidence were 41.17, 42.97, and 46.00 J/ml, respectively, i.e., doses higher than the 37.58 J/ml estimated by a deterministic procedure. The public health impact of these results is that the larger UV-H55 °C dose required for achieving 5-log reductions with 95, 99, and 99.9% confidence would reduce the probability of hemolytic uremic syndrome in children by 76.3, 88.6, and 96.9%, respectively. This study illustrates the importance of including the effect of data variability when selecting operational parameters for novel and conventional preservation processes to achieve high food safety standards with the desired confidence level.

Impact of caffeic acid addition on phenolic composition of tempranillo wines from different winemaking techniques

The effect of prefermentative and postfermentative caffeic acid (CFA) addition, prefermentative cold maceration, and a simulation of the micro-oxygenation technique through acetaldehyde addition on the phenolic and color composition of Tempranillo wines was investigated. Cold soaking and dry ice addition were performed as prefermentative techniques. Wines were analyzed after the end of the malolactic fermentation and after 6 and 12 months' storage. The results showed an important effect in wines to which CFA had been added, suggesting intramolecular copigmentation reactions through direct interaction between anthocyanins and free phenolic acids, thereby increasing the acylated anthocyanin fraction with an increase in color stability. The higher concentration of total phenols and lower hue values in CFA-added wines also contributed to the stability of these compounds during storage. Prefermentative cold maceration was shown to be influenced by the vintage. Phenolic acids, the acylated anthocyanin fraction, and total phenolics showed higher values in CFA-added and acetaldehyde-added wines. No differences were found in color density between the control wines and both the prefermentative and postfermentative CFA-added wines. However, a higher anthocyanin polymeric fraction and higher acylated anthocyanins, phenolic acids, and total phenols were observed in the CFA-added wines. The implications of this for the color stability of Tempranillo are also discussed.

Evaluation of total white blood cell count as a marker for proviral load of bovine leukemia virus in dairy cattle from herds with a high seroprevalence of antibodies against bovine leukemia virus

OBJECTIVE

To determine the reference interval for WBC counts in Holstein dairy cows from herds with high seroprevalence for anti-bovine leukemia virus (BLV) antibodies, analyze the correlation of total WBC counts and blood proviral load (bPVL) in BLV-infected animals, and determine whether total WBC count can be used a hematologic marker for in vivo infection.

ANIMALS

307 lactating cows from 16 dairy herds with high BLV seroprevalence.

PROCEDURES

Blood samples were collected for assessment of plasma anti-BLV p24 antibody concentration (all cows), manual determination of WBC count (161 BLV-seronegative cows from 15 herds), and evaluation of bPVL (146 cows from another herd).

RESULTS

The WBC count reference interval (ie, mean ± 2 SD) for BLV-seronegative dairy cows was 2,153 to 11,493 cells/μL. Of the 146 cows used to analyze the correlation between WBC count and bPVL, 107 (73%) had WBC counts within the reference interval; of those cows, only 21 (19.6%) had high bPVL. Most cows with high WBC counts (35/39) had high bPVL. Mean WBC count for cows with high bPVL was significantly higher than values for cows with low or undetectable bPVL. White blood cell counts and bPVL were significantly (ρ = 0.71) correlated.

CONCLUSIONS AND CLINICAL RELEVANCE

These data have provided an updated reference interval for WBC counts in Holstein cows from herds with high BLV seroprevalence. In dairy cattle under natural conditions, WBC count was correlated with bPVL; thus, WBC count determination could be a potential tool for monitoring BLV infection levels in attempts to control transmission.

Lack of mitochondrial DNA structure in Balkan donkey is consistent with a quick spread of the species after domestication

A total of 132 mtDNA sequences from 10 Balkan donkey populations were analysed to ascertain their regional genetic structure and to contribute to the knowledge of the spreading of the species after domestication. The Balkan donkey sequences were compared with those from 40 Burkina Faso donkeys as an African outgroup to account for possible local Balkan scenarios. The 172 sequences gave 62 different haplotypes (55 in Balkan donkey). Virtually all the analysed populations had haplotypes assigned to either Clade 1 or Clade 2 even though the relative proportion of Clade 1 or 2 haplotypes differed across populations. Geographical maps constructed using factors computed via principal component analysis showed that the Balkan donkey populations are not spatially structured. AMOVA confirmed a lack of genetic structure in Balkan donkey mtDNA. Balkan populations were poorly differentiated (ΦST  = 0.071). Differentiation between the Balkan donkey and the African outgroup also was low. The lack of correspondence between geographical areas and maternal genetic structure is consistent with the hypothesis suggesting a very quick spread of the species after domestication. The current research illustrates the difficulties to trace routes of expansion in donkey, as the species has no geographical structure.

Inactivation of Salmonella enterica by UV-C light alone and in combination with mild temperatures

The aim of this investigation was to study the efficacy of the combined processes of UV light and mild temperatures for the inactivation of Salmonella enterica subsp. enterica and to explore the mechanism of inactivation. The doses to inactivate the 99.99% (4D) of the initial population ranged from 18.03 (Salmonella enterica serovar Typhimurium STCC 878) to 12.75 J ml(-1) (Salmonella enterica serovar Enteritidis ATCC 13076). The pH and water activity of the treatment medium did not change the UV tolerance, but it decreased exponentially by increasing the absorption coefficient. An inactivating synergistic effect was observed by applying simultaneous UV light and heat treatment (UV-H). A less synergistic effect was observed by applying UV light first and heat subsequently. UV did not damage cell envelopes, but the number of injured cells was higher after a UV-H treatment than after heating. The synergistic effect observed by combining simultaneous UV and heat treatment opens the possibility to design combined treatments for pasteurization of liquid food with high UV absorptivity, such as fruit juices.

Bovine leukemia virus p24 antibodies reflect blood proviral load

Background

Bovine leukemia virus (BLV) is worldwide distributed and highly endemic in Argentina. Among the strategies to prevent BLV dissemination, a control plan based on the selective segregation of animals according to their proviral load (PVL) is promising for our dairy productive system. The objective of this work was to study the relationship between the blood PVL and the antibody level, in order to identify whether the individual humoral response, i.e. the anti-p24 or anti-whole-BLV particle, could be used as a marker of the blood level of infection and thus help to recruit animals that may pose a lower risk of dissemination under natural conditions.

Results

The prevalence of p24 antibodies on the 15 farms studied was over 66%. The prevalence of p24 and whole-BLV antibodies and PVL quantification were analyzed in all the samples (n = 196) taken from herds T1 and 51. ROC analysis showed a higher AUC for p24 antibodies than whole-BLV antibodies (Z_reactivity: 3.55, P < 0.001; Z_titer: 2.88, P < 0.01), and as consequence a better performance to predict the proviral load status in herd 51. No significant differences were found between the performance of p24 and whole-BLV antibodies in herd T1. A significant positive correlation was observed between PVL values and p24 antibody reactivity in both farms (r _T1 = 0.7, P < 0.001, r ₅₁ = 0.71, P < 0.0001). The analysis was extended to the whole number of weak p24 antibody reactors (n = 311) of the other 13 farms. The mean of high PVL reactors within weak p24 reactors was 17.38% (SD = 8.92). In 5/15 farms, the number of weak p24 reactors with high PVL was lower than 10%.

Conclusions

We found that the humoral response reflected the level of in vivo infection, and may therefore have useful epidemiological applications. Whereas the quantitative evaluation of blood proviral load using real-time PCR is expensive and technically demanding, the measurement of antibodies in blood by ELISA is relatively straightforward and could therefore constitute a cost-effective tool in a BLV control intervention strategy, especially in highly infected herds such as Argentinean dairy ones.

Improved parkinsonism diagnosis using a partial least squares based approach

PURPOSE

An accurate and early diagnosis of Parkinsonian syndrome (PS) is nowadays a challenge. This syndrome includes several pathologies with similar symptoms (Parkinson's disease, multisystem atrophy, progressive supranuclear palsy, corticobasal degeneration and others) which make the diagnosis more difficult. (123)I-ioflupane allows to obtain in vivo images of the brain that can be used to assist the PS diagnosis and provides a way to improve its accuracy.

METHODS

In this paper, we show a novel method to automatically classify (123)I-ioflupane images into two groups: controls or PS. The proposed methodology analyzes separately each hemisphere of the brain by means of a novel approach based on partial least squares (PLS) and support vector machine.

RESULTS

A database with 189 (123)I-ioflupane images (94 controls and 95 pathological images) was used for evaluation purposes. The application of the proposed method based on PLS yields high accuracy rates up to 94.7% with sensitivity = 93.7% and specificity = 95.7%, outperforming previous approaches based on singular value decomposition, which are used as a reference.

CONCLUSIONS

The use of advanced techniques based on classical signal analysis and their application to each hemisphere of the brain separately improves the (assisted) diagnosis of PS.

Mitochondrial DNA and Y-chromosome diversity in East Adriatic sheep

Variation in mitochondrial DNA (mtDNA) and Y-chromosome haplotypes was analysed in nine domestic sheep breeds (159 rams) and 21 mouflon (Ovis musimon) sampled in the East Adriatic. Mitochondrial DNA analyses revealed a high frequency of type B haplotypes, predominantly in European breeds, and a very low frequency of type A haplotypes, which are more frequent in some Asian breeds. Mitochondrial haplotype Hmt-3 was the most frequent (26.4%), and 37.1%, 20.8% and 7.6% of rams had haplotypes one, two and three mutations remote from Hmt-3 respectively. In contrast, Y-chromosome analyses revealed extraordinary paternal allelic richness: HY-6, 89.3%; HY-8, 5.0%; HY-18, 3.1%; HY-7, 1.3%; and HY-5, 1.3%. In fact, the number of haplotypes observed is comparable to the number found in Turkish breeds and greater than the number found in European breeds so far. Haplotype HY-18 (A-oY1/135-SRYM18), identified here for the first time, provides a link between the haplotype HY-12 (A-oY1/139-SRYM18) found in a few rams in Turkey and haplotype HY-9 (A-oY1/131-SRYM18) found in one ram in Ethiopia. All mouflons had type B mtDNA haplotypes, including the private haplotype (Hmt-55), and all were paternally monomorphic for haplotype HY-6. Our data support a quite homogeneous maternal origin of East Adriatic sheep, which is a characteristic of European breeds. At the same time, the high number of haplotypes found was surprising and intriguing, and it begs for further analysis. Simultaneous analysis of mtDNA and Y-chromosome information allowed us to detect a large discrepancy between maternal and paternal lineages in some populations. This is most likely the result of breeder efforts to 'upgrade' local populations using rams with different paternal origins.

[Surgical treatment of adrenal gland metastases: results in a series of 35 patients]

INTRODUCTION

The objectives of this study are to present the results of adrenalectomies due to metastasis, and to analyse the prognostic factors that may help to predict long-term survival in this patient group.

PATIENTS AND METHODS

A retrospective study was conducted on 35 patients who underwent adrenalectomy for metastases in the Hospital de Cruces from 1996 to January 2010. The survival analysis was performed using the Kaplan and Meier method.

RESULTS

Non-small cell lung cancer (NSCLC) was the most frequent primary tumour, with 18 cases. In 15 patients the diagnosis of adrenal metastasis was synchronous with the primary tumour, and in 20 cases it was metachronous. Only 7 patients survived without disease for 12, 22, 26, 58, 60, 65 and 120 months after the adrenalectomy. The disease free survival at 5 years was 16% in the whole series, and 27% in the NSCLC sub-group. None of the prognostic factors evaluated (size greater than 4.5 cm, cell type, differentiation grade, chemotherapy, surgical technique, disease free interval) was statistically significant in the overall survival, either in the general series or in the sub-group of patients with NSCLC. However, in the general series with tumour recurrence, the difference in survival between metachronous and synchronous metastasis was statistically significant (P=.05), in favour of the former.

CONCLUSIONS

Adrenalectomy improves the expected survival particularly in patients with NSCLC. Patients with metachronous metastases do not have a higher rate of disease free survival at 5 years than those with synchronous metastases, although they do have a longer survival with the disease. When there is tumour recurrence, it is usually early.

P2-08-05: Use of Dynamic Contrast-Enhanced MR Imaging To Predict Pathological Response in Primary Breast Cancer

Purpose: To investigate the effect of bevacizumab infusion on vascular parameters assessed by dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging and to test their association with pathological response in primary breast cancer.

Materials and Methods: 73 patients (median age, 47 ys; age range, 29–70 ys) with biopsy-proven, previously untreated, primary breast cancer were recruited from October 2009 to November 2010 in this phase II, multicenter and non-randomized clinical trial. Patients (pts) received single infusion of bevacizumab (15 mg/kg) (C1) 3 weeks prior to the beginning of neoadjuvant chemotherapy consisting in 4 cycles of docetaxel (60 mg/mq), doxorubicin (50 mg/mq) and bevacizumab (15 mg/kg) every 21 days (C2-C5) following by surgery. All pts underwent DCE-MR imaging before and 14–21 days after C1. Quantitative and semiquantitative kinetic parameters were calculated at baseline and after C1, including the volume transfer constant (K(trans)), which primarily reflects the wash-in of the contrast agent, the backflow rate contrant (K(ep)), extracellular volume fraction (V(e)) and the initial area under the gadolinium concentration-time curve over 60 seconds (IAUGC(60)). Changes in the DCE-MRI kinetic parameters K(trans), K(ep), V(e) and IAUGC(60) were calculated and Wilcoxon test was used to assess significant effects induced by bevacizumab on kinetic parameters. Pathological response on surgical specimens after C5 was assessed according to Miller and Payne classification. Pts with tumor reduction &gt;30% were considered as responders (G3-G4-G5) whether tumor reduction &lt;30% were considered as no responders (G1-G2). DCE-MR imaging parameters and clinical-pathological characteristics were correlated with pathological response using Mann-Whitney test in univariate and logistic regression in multivariate analyses. Receiver operating curves (ROC) was used to define the best cut-off of the parameter found associated with pathological response.

Results: DCE-MRI was performed before (n=72) and after (n=71) C1. K(trans), K(ep), V(e) and IAUCG(60) values were significantly different at the baseline and after C1 (p&lt;0.01). Median changes were, respectively, −51, −101, −52.5 and −4.8. Fifty-two (74%) pts achieved response (G3-G4-G5) after C5 whether 18 (24%) were considered as no responder (G1-G2); for 3 (4%) patients Miller/Payne tumor evaluation was not available. At univariate analysis, negative estrogen receptor (ER) status and higher post-C1 K(ep) (p=.057) showed a trend toward an association with response. At multivariate analysis, only ER status remains a significant predictor of response (p= .04). Area under ROC curve for K(ep) was 0.65 (IC95% 0.05−0.8, p=.057)

Conclusion: Bevacizumab affects tumor vasculature, perfusion and permeability as showed by the significantly reduction in all kinetic vasculature parameters obtained in DCE-MR imaging after C1. However, in our population these changes were not associated with pathological response. On the other hand, backflow rate constant, K(ep), a perfusion-related parameter derived from DCE-MRI yielded after C1 major than 80, may be associated with higher pathological response with a specificity of 88% and sensitivity of 90%. Future studies are warranted to confirm these findings.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-08-05.

P5-13-04: Changes in Phosphorylation Status at VEGFR2 and Basal Tumor Hypoxic Volume Assessed by Misonidazol (MISO) Positron Emission Tomography (PET/CT) as Potential Biomarkers for Predicting Response to Bevacizumab in Breast Cancer

Background: To evaluate the expression of novel putative biomarkers as predictors of benefit from bevacizumab in stage II-III, previously untreated breast cancers (BC) patients (pts) in the context of a phase II, single-arm, multicenter and prospective clinical trial. To address this aim, we examined baseline and induced changes after a single bevacizumab administration as potential early predictors of response. Methods: Pts received a single infusion of bevacizumab (15 mg/kg) (C1) 3 weeks prior to the beginning of neoadjuvant chemotherapy consisting in 4 cycles of docetaxel (60 mg/mq), doxorubicin (50 mg/mq) and bevacizumab (15 mg/kg) every 21 days (C2-C5) following by surgery. Early assessment of tumor changes was performed by paired tumor-biopsies and MISO PET/CT before and 14–21 days after bevacizumab administration (C1). Biomarker expression was assessed by immunohistochemistry (IHC) (Ki67, CD31, CD31/Ki67, VEGFR2, pVEGFR2 [Y951]) on formalin-fixed, paraffin-embedded tissue before and after bevacizumab infusion (C1). MISO SUV and tumor volume depicted by PET were calculated. Pathological response on surgical specimens was assessed according to Miller/Payne classification. Pts with tumor reduction &gt;90% were considered as best responders (G4-G5) whether tumor reduction &lt;90% were considered as no responders. Association between pathological response, IHC and MISO biomarkers was analyzed using Mann-Whitney test. ROC curve was performed to test sensibility and specificity of the biomarker found significantly associated with response and its value as independent predictor was tested in the multivariate analysis using logistic regression.

Results: This analysis was performed on the training set including 73 patients (49 yr, range 29–70). Twenty (27%) patients obtained best response (G4-G5) whether 50 (68%) were considered as no responder (G1-G2-G3). Response was associated with negative estrogen receptors expression (p=0.02) and high Ki67 basal and after C1 expression (p=0.009 and p=0.01). Six (54%) of triple negative tumors were responders (p=0.05). Interestingly, change in pVEGFR2 [Y951] staining induced by bevacizumab administration and basaline MISO tumor volume was found significantly associated with response (p=0.03 and 0.057). Decrease in the phosphorilation status of VEGFR2 (Y951) &gt;70% yielded a receiver operating characteristic (ROC) curve area of 0.681 (95% CI: 0.536 — 0.825) with 84% sensitivity and 95% specificity. The positive and negative predictive values for this marker were 60% and 64%, respectively. The change in phosphorilation status of VEGFR2p remains a significant predictor biomarker of response in multivariate analysis (OR=0.9, IC%95 0.96−0.99, p=0.04) after adjusting for clinical-pathological characteristics.

Conclusion: These findings underline the potential value of early decrease in phosphorilation status of VEGFR2 after bevacizumab infusion as predictive biomarker of response to anti-angiogenic therapy in breast cancer. Moreover, tumor hypoxic volume obtained by MISO might be associated with response. A validation set is warranted to confirm these findings.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-04.