ATM gene expression is associated with differentiation and angiogenesis in infiltrating breast carcinomas

The product of the ATM gene, mutated in the human genetic disorder ataxia-telangiectasia (A-T) plays a key role in the detection and repair of DNA double-strand breaks. A-T is defined by progressive cerebellar ataxia, telangiectasia, sensitivity to ionising radiation and genomic instability with cancer predisposition. On the other hand, increased angiogenesis is essential for tumor growth and metastasis. The aim of this study was to investigate ATM expression in breast carcinomas and its relationship to neoangiogenesis.

METHODS AND RESULTS

Fifty-two breast tumors from 51 patients, 38 of them with concomitant in situ component (CIS), were analyzed by immunohistochemistry for the expression of ATM. CD34 expression was used for the morphometric evaluation of vasculature. ATM was positive in 1 to 10% of normal epithelial cells. ATM expression was reduced in 55.8% of infiltrating carcinomas, non-reduced in 34.6%, and increased in 9.6%. Expression of ATM in CIS was similar to the infiltrating component in 71% of cases and reduced in 23.7% of them. High-grade ductal infiltrating carcinomas showed lower ATM expression than low-grade ones. Reduced ATM expression also correlated with increased microvascular area.

CONCLUSIONS

Reduced ATM expression in breast carcinomas correlated with tumor differentiation and increased microvascular parameters, supporting its role in neoangiogenesis and tumor progression in breast carcinogenesis.

Facilitation of enkephalins-induced delta-opioid behavioral responses by chronic amisulpride treatment

The endogenous opioid system is known to have a great influence on the dopaminergic system. Conversely, blockade of the dopaminergic system in D2 receptor knock-out mice triggers an increase in enkephalin supporting the important physiological relationship between both systems. Therefore, the aim of this study was to investigate whether or not chronic treatment with the specific D2 antagonist amisulpride (20mg/kg, i.p., twice daily for 5 days) could lead to a facilitation of behavioral effects of enkephalins, protected from their enzymatic degradation by the dual inhibitor N-[(R,S)-2-benzyl-3[(S)(2-amino-4-methylthio)butyl dithio]-1-oxopropyl]-l-phenylalanine benzyl ester (RB101) (5mg/kg, i.v.) in mice. RB101 induced an increase in locomotor activity, antidepressant-like effects in the forced swim test, and antinociceptive effects in the hot-plate test. Chronic treatment with amisulpride potentiated the action of RB101 and this effect seemed to be restricted to behavioral responses induced by opioids acting on delta-opioid receptors (locomotor activity and forced swim test). This was confirmed by the use of the selective delta-opioid receptor agonist, (+)-4-[alpha-R*)-alpha-((2S*,5R*)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N-diethylbenzamide (SNC80; 2.5mg/kg, i.p.), and antagonist, naltrindole (5mg/kg, i.p.). Considering the involvement of delta-opioid receptors in mood regulation, the interaction between amisulpride and RB101 could lead to a new therapeutic approach in the treatment of some mood disorders.

Compensation processes of Aleppo pine (Pinus halepensis Mill.) to ozone exposure and drought stress

A long-term experiment was performed to study the effects of O3 and drought-stress (DS) on Aleppo pine seedlings (Pinus halepensis Mill.) exposed in open-top chambers. Ozone reduced gas exchange rates, ribulose-1,5-biphosphate carboxylase/oxygenase activity (Rubisco), aboveground C and needle N concentrations and C/N ratio and Ca concentrations of the twigs under 3 mm (twigs<3) and the aerial biomass. Also it increased phosphoenolpyruvate carboxylase (PEPc) and N and K concentrations of the twigs<3. Water stress decreased gas exchange rates, predawn needle water potential (PsiPd), C/N ratio, twigs<3 Ca, plant growth, aerial biomass and increased N, twigs with a diameter above 3 mm P and Mg concentrations. The combined exposure to both stresses increased N concentrations of twigs<3 and roots and aboveground biomass K content and decreased root C, maximum daily assimilation rate and instantaneous water use efficiency. The sensitivity of Aleppo pine to both stresses is determined by plant internal resource allocation and compensation mechanisms to cope with stress.

Cost effectiveness and delivery study for future HIV vaccines

Research teams from five countries, Brazil, China, Kenya, Peru and Thailand, have initiated a policy-maker survey on vaccine delivery, cost studies for future HIV vaccination programmes, and associated simulation modeling exercises analysing the relative cost-effectiveness of potential HIV vaccination strategies. The survey assesses challenges and opportunities for future country-level HIV vaccination strategies, providing data on the vaccine characteristics (e.g. vaccine efficacies for susceptibility, infectiousness and disease progression) and vaccination programme strategies to be considered in the cost-effectiveness modeling analyses. The study will provide decision-makers with modeling data on vaccination policy considerations that will assist in developing country-level capacities for future HIV vaccine policy adoption and effective delivery systems, and will help delineate the long-term financial requirements for sustainable HIV vaccination programmes. The WHO-UNAIDS HIV Vaccine Initiative and the collaborating researchers welcome comments or questions from policy makers, health professionals and other stakeholders in the public and private sectors about this effort to help advance policy and capacity related to future potential HIV vaccines.

Evaluation of new external quality assessment guidelines involving random blinded rechecking of acid-fast bacilli smears in a pilot project setting in Mexico

SETTING

Laboratories in Mexico that support the national tuberculosis (TB) control program have been involved in an acid-fast bacilli (AFB) microscopy external quality assurance program which includes rechecking 100% of smears identified as AFB-positive by the local laboratories and 10% of smears identified as AFB-negative. Very few errors have been detected in Mexico using non-random selection and unblinded rechecking of the slides.

OBJECTIVE

To evaluate the results from a 1-year pilot program involving blinded rechecking of randomly selected AFB slides from local TB laboratories in two Mexican states and determine its feasibility for future implementation.

DESIGN

To reduce potential bias, laboratory staff from the National TB Laboratory, Institute for Epidemiological Diagnosis and Reference (InDRE), performed quarterly statistical sampling of AFB smears and on-site evaluations in local laboratories in each state. AFB smears were rechecked at the respective state laboratories with discordant results resolved at InDRE.

RESULTS

A significantly greater percentage of errors was detected on the randomly selected, blinded AFB smears than on the non-randomly selected, unblinded smears.

CONCLUSION

Random blinded rechecking provides more accurate estimates of AFB microscopy results, resulting in improved diagnosis and monitoring of treatment response.

Levofloxacin in the treatment of pneumonia in intensive care unit patients

In this study, we analyzed 302 patients with pneumonia admitted to the Intensive Care Unit (ICU) who were treated with levofloxacin (LFX) either as monotherapy or combined therapy. Pneumonia was classified as community-acquired in 220 (73%) patients, extra-ICU nosocomial-acquired in 43 (14%), and intra-ICU nosocomial-acquired in 39 (13%) patients. Treatment with LFX was used empirically in 85.7% of the cases. Initial doses of LFX were 500 mg every 24 h in 48.5% of the cases and 500 mg every 12 hours in 48.3%. Treatment was maintained for a mean (SD) of 12.6 (21.9) days. Treatment began as monotherapy in 116 (38.4%) patients and as combination therapy in 186 (61.6%). The factors that influenced the choice of combined treatment were septic shock (odds ratio [OR] 3.03; 95% confidence interval [CI] 1.50-6.12) and the presence of two or more extrinsic factors (OR 1.83; 95% CI 1.04-3.23), while young age was a variable associated with monotherapy (OR 0.98; 95% CI 0.96-0.99). An etiological diagnosis was made in 61.6% of the cases. LFX administration was changed from the intravenous route to oral administration in 85 (28.6%) patients. Satisfactory clinical response (cure and improvement) was achieved in 69.4% of the community-acquired pneumonia, in 55.8% of the extra-ICU nosocomial infection, and in 78.3% of the intra-ICU nosocomial infection. The overall mortality rate was 31.5%. Variables associated with death during ICU stay were combined therapy (OR 3.07; 95% CI 1.23-7.65), septic shock (OR 3.49; 95% CI 1.30-9.39), or therapeutic failure (OR 32.6; 95% CI 13.5-78.9). A total of 15% of the patients experienced adverse effects possibly or probably related the antibiotic given.

CD4+ T-cell recovery and clinical outcome in HIV-1-infected patients exposed to multiple antiretroviral regimens: partial control of viremia is associated with favorable outcome

The goal of antiretroviral therapy is clinical benefit through the suppression of viral replication and the immunologic reconstitution of HIV-1-infected patients. In spite of the availability of different highly active antiretroviral therapy only some patients sustain undetectable plasma viremia. We performed an observational study from October 1987 to February 2001 on immunologic and clinical outcome of 148 HIV-1-infected patients from an open clinical cohort at São Paulo University, Brazil. The median T CD4+ at starting first monitored regimen was 227 cells per microliter, with 65% of patients previously exposed to antiretroviral regimens, mostly dual therapy. Virologic response to antiretroviral therapy, after a median period of 179 weeks of monitored treatment, allowed classifying patients as aviremic (RNA plasma viremia below 500 copies per milliliter); viremic (current viral load at historic levels), and viremic-attenuated groups (detectable viremia, but > 1 log viral suppression). HIV RNA viral load, T CD4+ cells count, HIV-1 pol sequencing, inflammatory parameters, and clinical events were documented during a median follow-up of 251 weeks. This study observed better clinical and immunologic responses in the aviremic group, but the viremic-attenuated group showed a significant gain in CD4+ cells (p < 0.013) and a decreased number of cases progressing to an AIDS-defining clinical condition (p < 0.001) compared to the viremic group.

[Levofloxacin in patients in the ICU. Factors influencing the choice of dose and its use in combined therapy]

This study aimed to identify factors that influence the selection of different approaches to prescribing levofloxacin (e.g., monotherapy vs. combined therapy, 12-h vs. 24-h interval) and the effect on mortality in the ICU. An observational, prospective, multicenter study was conducted. A logistic regression analysis was performed to identify factors associated with the prescription of levofloxacin in combined therapy and at a dose of 500 mg every 12 hours. In addition, a logistic regression analysis was conducted to determine the impact of the different prescribing methods on mortality in the ICU. The most frequently administered initial dose was 500 mg/24 h (48.5%) and 500 mg/12 h (48.3%). No factors were found to influence the choice of daily dose. A total of 49.7% of levofloxacin prescriptions were in combined therapy. Factors influencing the decision to prescribe a combined regimen included diagnosis of extra-ICU nosocomial infection (OR: 1.97; 95% CI: 1.13-3.42); severe sepsis (OR: 2.56; 95% CI: 1.66-3.94); septic shock (OR: 6.22; 95% CI: 3.54-10.9); and identification of the causative pathogen (OR: 1.99: 95% CI: 1.34-2.95). The mortality rate was 21.4% and the related factors were septic shock (OR: 3.09; 95% CI: 1.38-6.91); treatment failure (OR: 23.4; 95% CI: 12.3-44.6); and combined therapy (OR: 2.36; 95% CI: 1.21-4.59). The selection of the initial dose of levofloxacin was not influenced by any factor, as long as the antibiotic was given in combined therapy in patients in whom the cause of the infection had been identified, in patients with greater systemic response, and in nosocomial infection outside the ICU. The selection of combined therapy was associated with a worse prognosis.

Amplification of T cells from human cord blood in serum-deprived culture stimulated with stem cell factor, interleukin-7 and interleukin-2

We report the effects exerted by cytokine combinations, including stem cell factor (SCF), interleukin-7, interleukin-4 and interleukin-2, on the amplification of T cells from cord blood (CB) mononuclear cells cultured for 10-11 days under serum-deprived conditions. Of all the combinations investigated, SCF+interleukin-7 sustained the best fold increase (FI) of total nucleated cells (FI=6.4+/-1.17), amplifying preferentially CD4(+) over CD8(+) T-cell subsets (FI=4.72+/-0.79 vs 2.73+/-1.2, respectively, P<0.05). The addition of interleukin-2 to this combination did not significantly increase the total number of cells generated (FI=7.4+/-2.27), but allowed preferential amplification of CD8(+) over CD4(+) T cells (FI=6.04+/-0.14 vs 1.67+/-0.6, respectively, P<0.05). Single-strand conformation polymorphism analysis of the T-cell receptor V(beta)-chain rearrangements expressed by the expanded T cells indicated that the complexity of the T-cell repertoire had increased after 10 days of culture in the presence of SCF and IL-7. Interestingly, a modest expansion (FI=8.67+/-1.5) of myeloid progenitor cells was also observed in these cultures. These results indicate that it is possible to expand specific T-cell subsets for adoptive immunotherapy without losing myeloid progenitor cells necessary for neutrophil recovery after CB transplantation, by modulating the cytokines added to the cultures.

Mucosal immune responses following oral immunization with rotavirus antigens encapsulated in alginate microspheres

Availability of effective oral vaccine delivery vehicles should contribute to the success of oral immunization in domestic animals. To achieve this goal, we evaluated alginate microspheres for their capacity to induce mucosal immune responses following oral and enteric immunizations. Mice were immunized with either live porcine rotavirus (PRV) or its recombinant VP6 protein, encapsulated in alginate microspheres or unencapsulated. VP6-specific IgG (but no IgA) antibodies were detected in the sera of mice after a single intraperitoneal (i.p.) immunization with either VP6 in Incomplete Freund's adjuvant (VP6-IFA), VP6 in alginate microspheres (VP6-MS) or with live PRV in incomplete Freund's adjuvant (PRV-IFA). In contrast, VP6-specific IgA (but no IgG) was detected in culture supernatants of mesenteric lymph nodes from mice immunized i.p. with either VP6-IFA or with PRV-IFA. Oral immunization with VP6-MS induced the highest level of VP6-specific fecal IgA antibody, similar to responses induced by oral immunization with live PRV. Furthermore, the VP6-specific fecal IgA could be boosted by a secondary i.p. immunization with VP6. Further experiments were performed in a sheep intestinal 'loop' model to evaluate uptake of microspheres by Peyer's patches. Microspheres containing colloidal carbon were specifically bound and transported by follicle-associated epithelium of Peyer's patches. Additionally, mucosal immune responses were detected following enteric immunization with porcine serum albumin (PSA) encapsulated in alginate microspheres. Our results confirm that alginate microspheres are an effective oral delivery vehicle for protein antigens and intestinal IgA antibody responses are induced by antigens encapsulated in alginate microspheres without any additional mucosal adjuvant. These investigations confirm that alginate microspheres have the potential as an effective delivery vehicle for oral immunization of ruminants.

Comparison of populations as a function of confidence intervals of gene probability

A new method for population comparison has been developed in order to determine the most discriminating systems in relation to diverse populations. The method compares pairs of populations on the basis of confidence intervals for allelic frequencies and does not require any previous assumption, such as normality of the population. A data set of 12 populations studied for Polymarker Kit (Roche) genetic systems, 13 biallelic systems (LDLR, GYPA, D7S8) and two systems with three alleles each (HBGG, GC), was considered. The analysis produced a total of 144 confidence intervals (12 populations x 12 alleles). The raw data were then analyzed comparing pairs of populations, allele by allele, through their respective confidence intervals. The method calculates the matrix of similarity between pairs of populations for each allele and eventually for each genetic system. Finally, the 12 populations were classified depending on the number of nondiscriminating alleles. The results of this method are compared to those produced by such usual techniques as Principal Component Analysis.