Classification of exacerbation episodes in chronic obstructive pulmonary disease patients.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a progressive disease affecting the airways, which constitutes a major cause of chronic morbidity and a significant economic and social burden throughout the world. Despite the fact that in COPD patients exacerbations are common acute events causing significant and often fatal worsening of symptoms, an accurate prognostication continues to be difficult. OBJECTIVES: To build computational models capable of distinguishing between normal life days from exacerbation days in COPD patients, based on physical activity measured by accelerometers. METHODS: We recruited 58 patients suffering from COPD and measured their physical activity with accelerometers for 10 days or more, from August 2009 to March 2010. During this period we recorded six exacerbation episodes in the patients, accounting for 37 days. We were able to analyse data for 52 patients (369 patient days), and extracted three distinct sets of features from the data, one set of basic features such as average, one set based on the frequency domain and the last exploring the cross-information among sensors pairs. These were used by three machine-learning techniques (logarithmic regression, neural networks, support vector machines) to distinguish days with exacerbation events from normal days. RESULTS: The support vector machine classifier achieved an AUC of 90% ± 9, when supplied with a set of features resulting from sequential feature selection method. Neu- ral networks achieved an AUC of 83% ± 16 and the logarithmic regression an AUC of 67% ± 15. CONCLUSIONS: None of the individual feature sets provided robust for reasonable classification of PA recording days. Our results indicate that this approach has the potential to extract useful information for, but are not robust enough for medical application of the system.

Blood monocytes from most human immunodeficiency virus type 1-infected patients do not carry proviral DNA.

In blood, the CD4+ T cells of patients with human immunodeficiency virus type 1 (HIV-1) harbor HIV-1; however, whether the CD4+ blood monocytes carry the virus is controversial. Tissue macrophages are known to be infected. To determine in blood monocytes from HIV-1-seropositive patients contain HIV-1, we separated monocytes and T-cell subsets by using monoclonal antibodies bound to magnetic beads and by monocyte adherence to glass. Monocytes were cultured with macrophage colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, and interleukin-3. After 14 days in culture, cells were analyzed for the presence of HIV-1 antigen and multinucleated giant cells (MGCs). Freshly isolated cell subsets were analyzed for HIV-1 proviral DNA by PCR with modified env (SK68i and SK69i2) and gag (SK145i and SK150) primers. We found that (i) monocytes cultured without depletion of CD4+ T cells (11 of 11 patients) were HIV-1 antigen positive and showed dramatically increased spontaneous formation of MGCs (ii) monocytes cultured after depletion of CD4+ T cells (three experiments) were HIV-1 antigen negative and showed markedly decreased MGC formation, and (iii) in specimens from 14 patients subsequently analyzed by PCR, purified CD4+ T cells were positive for HIV-1 proviral DNA in all patients. In 11 of 14 patients (79%), the monocyte fractions were HIV-1 proviral DNA negative, while in the remaining 3 patients, the monocytes were positive for HIV-1 proviral DNA. In conclusion, the major reservoir for HIV-1 infection in human peripheral blood is the CD4+ T cell (14 of 14 cases).(ABSTRACT TRUNCATED AT 250 WORDS)

Stability of dried blood spot specimens for detection of human immunodeficiency virus DNA by polymerase chain reaction.

Blood sampling on filter paper has many advantages for the detection of perinatal human immunodeficiency virus (HIV) infection by the polymerase chain reaction (PCR). However, if the method is to be widely used, an assessment of its performance under field conditions is required. To simulate conditions in the field, 50-microliters aliquots of whole blood containing low levels of HIV proviral DNA (4 to 1,024 copies per 100,000 nucleated cells) were spotted onto filter paper; dried; and subjected to heat, humidity, and prolonged storage at room temperature. After exposure, the DNA was recovered and amplified with primers to human leukocyte antigen DQ alpha- and HIV-specific sequences. Treatment at 37 degrees C and 60% humidity for 7 days, storage for 12 weeks at 22 degrees C, and freeze-thawing twice had no adverse effect on PCR reactivity when compared with the results obtained with reference spots stored at -20 degrees C. The lower limits of HIV detection in all tests ranged from 4 to 16 HIV copies per 100,000 cells. Fixation in 70% ethanol improved the amplification of low levels of HIV DNA and reduced biohazard risks. These findings suggest that dried blood spots will provide a powerful new resource for testing for HIV by PCR, especially in remote areas where refrigeration and immediate sample processing are unavailable.

Rapid DNA fingerprinting to control for specimen errors in HIV testing by the polymerase chain reaction.

Variable-number-tandem-repeats (VNTRs) are highly polymorphic and provide informative genetic markers for distinguishing between individuals. We have used PCR amplification of VNTR locus pMCT118 to identify mislabelled specimens submitted for HIV PCR testing. The method is rapid, can be applied to large numbers of samples and eliminates the need for radioactive probes. DNA samples (10 ng) are amplified for 25 cycles using fluorescence-labelled oligonucleotide primers (blue dye). An aliquot of the PCR product is then combined with an internal lane size standard (labelled with a red dye), electrophoresed through a 2% agarose gel on an automated fluorescence DNA fragment analyser and the size and quantity of the fragments determined automatically relative to the internal standard. Fifteen alleles, ranging in size from 398 tp 709 bp were readily identified in a random sampling of DNA from 63 unrelated HIV-infected patients. Fragment size was reproducible and corresponded to alleles containing from 16 to 35 repeats of a 16 bp unit. VNTR genotyping will prove useful for resolving discordant results due to specimen mix-up and ensuring that the correct samples have been analyzed.

Improved detection of HIV-1 envelope sequences using optimized PCR and inosine-substituted primers.

We describe inosine-substituted 'consensus' primers for the detection of HIV-1 envelope sequences by the polymerase chain reaction. The primers, modifications of SK68 and SK69, are highly specific (100%) and sensitive (greater than 94%) and they prevent false-negative results due to variation in the HIV-1 genome. Consensus primers are needed to ensure the detection of most, if not all, variants of HIV-1 including American, African and newly emerging strains.

Long-term effects on health of air pollution in children.

A literature review is presented showing the role and relative importance of various endogenous and exogenous factors, classified into predisposing, provoking and facilitating factors, in the development of Chronic Non-Specific Respiratory Diseases (CNSRD) in children. The review is also based on the results of own clinical studies and a longitudinal epidemiological study. In total, 12,708 children were examined in the epidemiological study, including a cohort of 1,303 children examined three times. In the analysis of the frequency and the dynamics of respiratory symptoms, significant contribution of various factors was demonstrated, including history of obstructive bronchitis in the first year of life, frequency of respiratory infections in early childhood, passive tobacco smoking, socioeconomic conditions such as education of parents, day nursery and kindergarten attendance and living in an area with high levels of air pollution.

Dynamics of respiratory symptoms and lung function in epidemiological long-term study in children.

Dynamics of respiratory symptoms and past respiratory diseases were studied in a cohort of children examined twice. Relative risk of having the same symptom/disease after three years was calculated, producing a ranking of the symptoms, believed to reflect their epidemiological significance. An independent ordering of the symptoms was obtained, based on the relative risk of lower airways illness in a group of children followed-up for two years. In the analysis of lung function dynamics, practical independence of PEFR measurements and respiratory symptoms was confirmed.

[Clinical evaluation of Zaditen syrup in the treatment of children with bronchial asthma]. / Kliniczna ocena skutecznosci preparatu Zaditen (syrop) u dzieci z dychawica oskrzelowa.

60 children with atopic asthma were included to the doubleblind study, in order to compare Zaditen and Clemastine. The trial was completed after 12 weeks of treatment. The efficacy was evaluated on the basis of clinical observation, lung function measurements and laboratory data. The Zaditen was shown to have more beneficial clinical effect on studied group than Clemastine. The lung function measurements before and after treatment did not showed much difference, although a significant decrease of the nonspecific bronchial reactivity to histamine was observed in the group receiving Zaditen . This was observed shortly after beginning of the treatment up to 6 weeks. Zaditen sirup was well tolerated and the only side effect observed was a significant weight increase, which could be explained by the elevation of serum sodium ions concentration.