Chest radiography findings in primary pulmonary tuberculosis in children

Plain chest radiography plays a major role in the diagnosis and follow-up of pulmonary tuberculosis in childhood. The aim of our study was to investigate the distribution of characteristic chest radiographic findings at diagnosis in children with pulmonary tuberculosis. The age of the patients and the type and localization of radiographic changes at admission were retrospectively analyzed. We reviewed chest radiographs in 204 children admitted from January 1, 1991 until June 30, 1994 for newly diagnosed pulmonary tuberculosis. Mean age +/- SD was 6.4 +/- 4.2 years (range 0-14). The most common lesion was lymphadenopathy (found in 172 children, 84.3%). It was significantly more common in the youngest age group (0-4 years) and was more significantly present in the right hilo-mediastinal region. Parenchymal changes were found in 125 children (61.3%). They were also significantly more common in the young age group and in the right lung. Other less common lesions included pleuritis, atelectasis, destructive-cavitary lesions and miliary dissemination. In conclusion, the leading radiographic finding in pulmonary tuberculosis in childhood remains hilar lymphadenopathy, but parenchymal changes are clearly strongly present, and should be sought and appreciated in the diagnostic work-up for pulmonary tuberculosis in childhood.     

NAPO as a novel marker for apoptosis.

Apoptosis or programmed cell death plays a pivotal role in embryonic development and maintenance of homeostasis. It is also involved in the etiology of pathophysiological conditions such as cancer, neurodegenerative, autoimmune, infectious, and heart diseases. Consequently, the study of apoptosis is now at center of both basic and clinical research applications. Therefore, sensitive and simple apoptosis detection techniques are required. Here we describe a monoclonal antibody-defined novel antigen, namely NAPO (negative in apoptosis), which is specifically lost during apoptosis. The anti-NAPO antibody recognizes two nuclear polypeptides of 60 and 70 kD. The antigen is maintained in quiescent and senescent cells, as well as in different phases of the cell cycle, including mitosis. Thus, immunodetection of NAPO antigen provides a specific, sensitive, and easy method for differential identification of apoptotic and nonapoptotic cells.     

CA 549 as a marker in breast cancer.

CA 549 is one of several carcinoma associated mucin antigens proposed as a breast cancer tumor marker. In this study, the performance characteristics of the CA 549 assay were validated and the clinical utility of the test was compared with that of other breast cancer markers including CA 15-3, CA M26, CA M29 and carcinoembryonic antigen. The upper limit of normal was established as 15.5 U/ml based on data for 250 control subjects apparently free of disease. Overall, CA 549 had a low negative predictive value (0.51) due to a low sensitivity in the detection of early breast cancer. However, the test had a high positive predictive value (0.93) reflecting a high specificity for the disease. In 56 patients with advanced breast cancer, the sensitivity was 0.71 for CA 549 alone and 0.79-0.84 for CA 549 combined with any of the other markers studied.     

Dihydrofolate reductase gene as a versatile expression marker.

The Escherichia coli dihydrofolate reductase (DHFR) gene has been used as a genetic marker specifying trimethoprim resistance (TmpR). In order to use the DHFR gene as a versatile expression marker, we have constructed three types of plasmids: promoter cloning vector, terminator cloning vector, and the plasmid containing the DHFR gene cassette. In these systems, the selection of recombinant plasmids was carried out just by examining the TmpR phenotype of the transformed cells. Then, levels of the enzymatic activity of DHFR were measured to evaluate the efficiency of promoters and terminators in the fused DNA fragment. An expression plasmid which resulted in the E. coli host cells being able to produce DHFR up to 20% of total cellular proteins was also constructed by changing the promoter and Shine-Dalgarno sequences of the DHFR gene.     

Thrombomodulin as a marker of radiation-induced endothelial cell injury.

Cultured confluent human umbilical vein endothelial cells were irradiated in vitro with 60Co gamma rays at doses from 0 to 50 Gy. After irradiation thrombomodulin was measured at different times over 6 days in the supernatants of endothelial cell culture medium, on the surface of the cells, and within the cells. At 24 h after irradiation, an increase in the release of thrombomodulin from irradiated endothelial cells and an increase in the number of molecules and the activity of thrombomodulin on the surface of the cells were observed; these reactions were dependent on radiation dose. The capacity of the cells to produce and release thrombomodulin was decreased from 2 to 6 days after exposure to 60Co gamma rays. Our data indicate that radiation can injure endothelial cells, and that thrombomodulin may be used as a marker of radiation-induced injury in endothelial cells. The interrelationship between the dysfunction of irradiated endothelial cells and the pathological mechanisms of acute radiation disease is also discussed.     

Cortisol as a marker of stress

The review considers the roles cortisol (Crt), dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEA-S) play in the stress response. Age-related, sex-related, and circadian fluctuations in normal conditions and in acute or chronic stress are described for Crt, DHEA, and DHEA-S. The main techniques used to estimate the Crt level in the blood, urine, and saliva are described, and approaches to the interpretation of the results discussed. Special attention is paid to Crt assays in anthropological and psychological studies.     

Dynamics of fluorescence marker concentration as a probe of mobility.

We have developed an effective experimental system for the characterization of molecular and structural mobility. It incorporates a modified fluorescence microscope geometry and a variety of analytical techniques to measure effective diffusion coefficients ranging over almost six orders of magnitude, from less than 10(-11) cm2/s to greater than 10(-6) cm2/s. Two principal techniques, fluorescence correlation spectroscopy (FCS) and fluorescence photobleaching recovery (FPR), are employed. In the FPR technique, translational transport rates are measured by monitoring the evolution of a spatial inhomogeneity of fluorescence that is produced photochemically in a microscopic volume by a short burst of intense laser radiation. In contrast, FCS uses laser-induced fluorescence to probe the spontaneous concentration fluctuations in microscopic sample volumes. The kinetics are analyzed by computing time-correlation functions of the stochastic fluctuations of the measured fluorescence intensity. The optical system and digital photocount correlator designed around a dedicated minicomputer are described and discussed. The general power of these techniques is demonstrated with examples from studies conducted on bulk solutions, lipid bilayer membranes, and mammalian cell plasma membranes.     

Green fluorescent protein as a marker for Pseudomonas spp.

The development of sensitive methods for observing individual bacterial cells in a population in experimental models and natural environments, such as in biofilms or on plant roots, is of great importance for studying these systems. We report the construction of plasmids which constitutively express a bright mutant of the green fluorescent protein of the jellyfish Aequorea victoria and are stably maintained in Pseudomonas spp. We demonstrate the utility of these plasmids to detect individual cells in two experimental laboratory systems: (i) the examination of a mixed bacterial population of Pseudomonas aeruginosa and Burkholderia cepacia attached to an abiotic surface and (ii) the association of Pseudomonas fluorescens WCS365 with tomato seedling roots. We also show that two plasmids, pSMC2 and pGB5, are particularly useful, because they are stable in the absence of antibiotic selection, they place an undetectable metabolic burden on cells that carry the plasmids, and cells carrying these constructs continue to fluoresce even after 7 days in culture without the addition of fresh nutrients. The construction of improved Escherichia coli-Pseudomonas shuttle vectors which carry multiple drug resistance markers also is described.     

Peroxidase as a developmental marker in plant tissue culture.

Peroxidase was studied as a developmental marker in pumpkin (Cucurbita pepo L.) callus lines and horse-radish (Armoracia lapathifolia Gilib) transformants. Embryogenic callus lines DE grown on MS medium with 2.4-D and NA-3 grown on medium with NAA and adenine sulfate showed about a 20 times higher enzyme activity than the habituated non-embryogenic line Z5b/T grown on medium without hormones. A rise in peroxidase activity indicated that somatic embryogenesis was triggered in a few habituated tissue cultures. Separated globular embryoids had a manifold lower enzyme activity than the callus from which they originated. SDS-electrophoresis showed distinct polypeptide patterns between the horse-radish leaves and crown galls, but the tumor characteristic protein bands failed to be identified. In horse-radish crown galls and short bushy plants regenerated from hairy roots an enhanced peroxidase activity was registered. Due to its high peroxidase level and abundant biomass production horse-radish transformants should facilitate enzyme production.     

Neomycin resistance as a selectable marker in Methanococcus maripaludis.

We cloned the aminoglycoside phosphotransferase genes APH3'I and APH3'II between the Methanococcus voltae methyl reductase promoter and terminator in a plasmid containing a fragment of Methanococcus maripaludis chromosomal DNA. The resulting plasmids encoding neomycin resistance transformed M. maripaludis at frequencies similar to those observed for pKAS102 encoding puromycin resistance. The antibiotic geneticin was not inhibitory to M. maripaludis.     

Human sialidase as a cancer marker

Altered sialylation of cell surface glycoproteins and glycolipids is closely related to the malignant phenotype of cancer cells, including the metastatic potential and invasiveness. Many cancer-related antigens in clinical use contain sialic acids at the terminal position of sugar chains in the molecules. To elucidate the molecular mechanism, we focused our investigation on sialidase, which catalyzes the removal of sialic acid residues from the glycoconjugates. Four types of human sialidases identified to date behave in different manners during carcinogenesis. One of the sialidases, found in the lysosomes, showed downregulation in cancers, promoting anchorage-independent growth, and metastatic ability, while another, found in the plasma membrane, showed marked upregulation, causing apoptosis suppression. It was found that estimation of the mRNA levels of sialidases by real-time PCR allowed discrimination of cancerous from noncancerous tissues and even determination of the pathological stage in some cancers. Immunohistochemistry of cancer tissues using the antibody against the plasma membrane sialidase was useful for clinical diagnosis. This paper briefly summarizes our findings of the altered sialidase expression in cancers and the possibility of their clinical application as cancer markers. Human sialidases are indeed related to malignancy and may be potential targets for cancer diagnosis and therapy.     

Hemolysin as a marker for Serratia

All Serratia marcescens strains (total of 33) of different sources were hemolytic including clinical strains previously classified as being nonhemolytic. DNA fragments of the two hemolysin genes hybridized with the chromosomal DNA of S. marcescens, S. liquefaciens, S. kiliensis, S. grimesii, S. proteamaculans, S. plymutica, S. rubridaea which were also hemolytic. The restriction pattern of the hemolysin locus differed in each strain. S. ficaria and S. marinorubra expressed a different hemolysin which was much smaller than the S. marcescens hemolysin since it diffused through dialysis membranes. The DNA of the latter strains did not hybridize with the S. marcescens hemolysin DNA probes. Some S. marcescens strains, S. kiliensis and S. liquefaciens also expressed in addition the small hemolysin. No hybridization was found with DNA of Escherichia coli, Salmonella typhimurium, Proteus mirabilis, Proteus vulgaris, Citrobacter freundii, Enterobacter cloacae, Klebsiella arerogenes, Klebsiella pneumoniae, Shigella dysenteriae, Yersinia enterocolitica, Yersinia pseudotuberculosus, Listeria sp., Aeromonas sp., Legionella sp. and a Meningococcus sp., indicating that the hemolysin DNA probes are specific for Serratia, or that the hemolysin genes occur rarely in genera other than Serratia.