In vitro activity of AZD5847 against geographically diverse clinical isolates of Mycobacterium tuberculosis.

The MIC of the novel antituberculosis (anti-TB) drug AZD5847 was determined against 146 clinical isolates from diverse geographical regions, including eastern Europe, North America, Africa, and Asia, using the automated Bactec Mycobacterial Growth Indicator Tube (MGIT) 960 system. These isolates originated from specimen sources such as sputum, bronchial alveolar lavage fluid, pleural fluid, abscess material, lung biopsies, and feces. The overall MIC90 was 1.0 mg/liter (range, 0.125 to 4 mg/liter). The MICs of AZD5847 for isolates of Mycobacterium tuberculosis were similar among drug-sensitive strains, multidrug-resistant (MDR) strains, and extensively drug resistant (XDR) strains. The good in vitro activity of AZD5847 against M. tuberculosis and the lack of cross-resistance make this agent a promising anti-TB drug candidate.

Comparison of clinical isolates and in vitro selected mutants reveals that tlyA is not a sensitive genetic marker for capreomycin resistance in Mycobacterium tuberculosis.

OBJECTIVES: The aim of this study was to clarify the conflicting data regarding cross-resistance and drug-resistance mechanisms for the cyclic peptide capreomycin and the aminoglycosides amikacin and kanamycin by comparing genotypes and phenotypes of clinical isolates and in vitro selected mutants of Mycobacterium tuberculosis. METHODS: The genes rrs and tlyA and the promoter region of eis of 152 M. tuberculosis clinical isolates (including 55 capreomycin resistant) and 44 in vitro selected capreomycin-, amikacin- and kanamycin-resistant mutants were sequenced. In addition, MICs of capreomycin, amikacin and kanamycin on Middlebrook 7H10 were determined. RESULTS: The results clearly show major differences in genotypes and cross-resistance patterns to amikacin and kanamycin between the capreomycin-resistant clinical isolates and in vitro selected mutants. tlyA mutations were found almost exclusively among the in vitro selected capreomycin-resistant mutants, while only four were found among the clinical isolates, of which two were capreomycin susceptible. In contrast, 53 of the 55 capreomycin-resistant clinical isolates had a mutation at position 1401 in rrs and were resistant to capreomycin, amikacin and kanamycin. Low-level resistance to kanamycin was correlated to mutations in the promoter region of eis. CONCLUSIONS: Our findings are consistent with the belief that a mutation at position 1401 in rrs leads to resistance to capreomycin, amikacin and kanamycin. The data also show that tlyA is not a sensitive genetic marker for capreomycin resistance in clinical isolates of M. tuberculosis, as mutations in this gene are infrequent and not all mutations in tlyA lead to capreomycin resistance.

Histiocytoid cardiomyopathy and ventricular non-compaction in a case of sudden death in a female infant.

A case of sudden infant death with histiocytoid cardiomyopathy and ventricular non-compaction was investigated with immunohistochemical methods. Histiocytoid cardiomyopathy is thought to be a developmental defect of the cardiomyocytes of the conduction system. In contrast to mature cardiomyocytes, the histiocytoid cells showed only weak reactions to desmin and myosin antibodies. They lacked cross-striation but reacted strongly to enolase and myoglobin antibodies. The protein Pax-7, seen only in cells undergoing differentiation, and the proliferation marker Ki-67 were not expressed in the histiocytoid cells. In areas of altered myocardium, clusters of CD4-, CD8-, and CD68-positive inflammatory cells were seen as well an abundance of mast cells. With the TUNEL method, it was found that many of the histiocytoid cells were undergoing apoptosis. Our results confirm that the histiocytoid cells are defective cardiomyocytes. The apoptotic and inflammatory changes point to a degenerative process rather than defective maturation of cardiomyocytes as has been suggested in some earlier studies. Ventricular non-compaction is a developmental defect of the subendocardial tissue with hypertrabeculation and weak development of the papillary muscles. Only one case combined with histiocytoid cardiomyopathy has been described previously. A causal connection between the two conditions cannot be established until more cases have been analyzed.

TNF-alpha and IL-10 gene polymorphisms versus cardioimmunological responses in sudden infant death.

We hypothesized that genetic variations of cytokines could contribute to the risk of developing a fatal immunological reaction in the heart of infants. Thus, tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 gene polymorphisms versus induction of cardioimmunologxical responses in victims of sudden infant death syndrome (SIDS) were explored. We genotyped 35 infants (23 cases of SIDS and 12 infants with a known cause of death), and 100 healthy adult controls for IL-10 -1082 G/A, -592 C/A and TNF-alpha-238 G/A, -308 G/A. We found a higher frequency of the ATA haplotype and ATA/ATA genotype of IL-10 associated with SIDS (13%). The frequency of homozygote infants for IL-10 haplotypes in SIDS was higher (52%) than the control group (34%). All SIDS cases were homozygotice for the TNF-alpha-238 G allele and 20 infants were homozygous for the TNF-alpha-308 G allele in the same group. None of the infants with higher levels of infiltrated T-cells (n=8) was homozygous for IL-10 gene polymorphisms, whereas in contrast 3 cases of the 6 that displayed higher levels of cardiac mast cells were homozygous. In this study, the increased number of interstitial T-cells, mast cells, and macrophages in the myocardial interstitium demonstrated no correlation with the genotype for either cytokines.

Pathogenic role of cardiac mast cell activation/degranulation,TNF-alpha, and cell death in acute drug-related fatalities.

BACKGROUND: Intravenous injection of narcotic stimulants affects many cellular functions relevant for the pathophysiological mechanisms of heart failure. There is considerable evidence that mast cells (MCs), TNF-alpha, and cell death play crucial roles in the pathogenesis and progression of cardiac arrest. In this study, we examined and compared the participation of MCs, TNF-alpha, apoptosis and necrosis in the heart of drug-related fatalities and the victims of sudden death due to the cardiac failure or aortic dissection. METHODS AND RESULTS: Serum level of postmortem tryptase was determined in all study subjects that consisted of 50 autopsy cases: 30 drug overdose fatalities which were further divided into two groups with high and low level of tryptase, and 20 cases of sudden natural death (SND). The distribution profile of cardiac infiltrated-MCs and production patterns of TNF and C9 (necrotic marker) were investigated immunohistochemically. In situ-detection of apoptosis with TUNEL was applied to the heart sections. The level of tryptase was elevated (>45 microg/L) in the drug fatalities but remained below the cut-off value in SND. In the myocardium of overdose victims, MC-infiltration and degranulation were significantly increased as well as production of myocytic TNF-alpha compared with the SND cases. The expressions profile of myocytic TNF varied between the groups. Apoptotic myocytes were seen more frequently in the SND group while necrosis was more evident in the heart of drug-related fatalities. CONCLUSION: Mast cells are recruited and activated in the heart of drug-associated deaths and the myocytes are the main source of TNF-alpha with the ability of different production patterns. The high degree of MC degranulation and the elevated levels of tryptase together with the pathological changes in heart of drug-related victims resemble that of the anaphylactic deaths as demonstrated in our previous study.

The process of moving from a regionally based cervical cytology biobank to a national infrastructure.

This article addresses the important issue of the standardization of the biobank process. It reports on i) the implementation of standard operating procedures for the processing of liquid-based cervical cells, ii) the standardization of storage conditions, and iii) the ultimate establishment of nationwide standardized biorepositories for cervical specimens. Given the differences in the infrastructure and healthcare systems of various county councils in Sweden, these efforts were designed to develop standardized methods of biobanking across the nation. The standardization of cervical sample processing and biobanking is an important and widely acknowledged issue. Efforts to address these concerns will facilitate better patient care and improve research based on retrospective and prospective collections of patient samples and cohorts. The successful nationalization of the Cervical Cytology Biobank in Sweden is based on three vital issues: i) the flexibility of the system to adapt to other regional systems, ii) the development of the system based on national collaboration between the university and the county councils, and iii) stable governmental financing by the provider, the Biobanking and Molecular Resource Infrastructure of Sweden (BBMRI.se). We will share our experiences with biorepository communities to promote understanding of and advances in opportunities to establish a nationalized biobank which covers the healthcare of the entire nation.

A complex intervention for workflow enhancement at the Swedish cervical cytology biobank.

The primary responsibility of biobanks is to collect biospecimens that are true reflections of the local population, thereby promoting translational research that is applicable to the community. The Swedish Cervical Cytology Biobank (SCCB) was designed as a hospital-integrated biobank in 2011. The SCCB has now been implemented in 10 county councils scattered across the country. It is headquartered at Karolinska University Hospital in Stockholm. The SCCB now processes more than 60% of the liquid-based gynecological cell samples obtained throughout Sweden. To improve the productivity of health care and research that rely on SCCB samples, a high level validation of the biobank system according to the principles of Good Laboratory Practices (GLP) is required. The performance of an entire high-throughput system validated by measuring the cell yield proved unsatisfactory after 1 year of sample collection and aliquoting. However, the results led to a number of high quality technical interventions for workflow enhancement. Subsequently, the improved process was applied to the system and led to a significant increase in cell yield. After the integration of the improved high quality methodology into the SCCB, the biobank services progressed more rapidly to serve the needs of personalized medicine and clinical studies. This enhancement was mainly due to the increased ability of the biobank to provide samples to research groups without any risk of leaving insufficient sample volumes for the care of the donor.

The Swedish cervical cytology biobank: sample handling and storage process.

The Swedish Cervical Cytology Biobank (SCCB) is the first national initiative of a prospective repository for liquid-based gynecological cell samples (LBC) from women participating in organized cervical cancer screening programs. Development and implementation of a nationally standardized method for the handling and long-term storage of cervical cell samples has been a primary goal for the Swedish hub of The Biobanking and Molecular Resource Infrastructure (BBMRI.se, www.bbmri.se). The sample handling protocol was developed through i) review of the literature on biobanking processes, ii) wide consultation within the academic community, and iii) various verification assays in collaboration with the clinical cytology laboratories. A general quality management system, covering all aspects of sample handling and storage, has been established. BBMRI.se financed the development and implementation of SCCB. The protocol established in the pilot project in Stockholm is now being implemented in other counties in Sweden, and during this year, more than 120,000 LBC samples will be processed for biobanking nationwide. SCCB is embedded in a comprehensive cytology diagnostic registry and will be linked with the national cancer registry to constitute a nearly inexhaustible resource for performance of fundamental and applied biologic research.

An in vitro model for assessment of the biological activity of hepatocyte growth factor.

Hepatocyte growth factor (HGF) is a multifunctional growth factor with potent wound-healing properties that functions in the healing of chronic injuries. However, there may be a loss of HGF activity in certain chronic cases; this might be indicated by the presence of high amounts of HGF in body fluids and by the elevated expression of the HGF receptor in tissue biopsies. In such cases, a reliable means of assessing the activity of endogenous HGF would be valuable in allowing clinicians to decide if treatment with HGF would be useful. In this study, we developed an in vitro wound assay that used a mouse skin epithelial cell line to evaluate the biological activity of HGF. We showed that HGF accelerated the motility of the epithelial cells in a dose-dependent fashion with high sensitivity and specificity. This in vitro assay might be used to determine the activity of both endogenous and recombinant HGF.

Mycobacterium tuberculosis promotes apoptosis in human neutrophils by activating caspase-3 and altering expression of Bax/Bcl-xL via an oxygen-dependent pathway.

In addition to direct bactericidal activities, such as phagocytosis and generation of reactive oxygen species (ROS), neutrophils can regulate the inflammatory response by undergoing apoptosis. We found that infection of human neutrophils with Mycobacterium tuberculosis (Mtb) induced rapid cell death displaying the characteristic features of apoptosis such as morphologic changes, phosphatidylserine exposure, and DNA fragmentation. Both a virulent (H37Rv) and an attenuated (H37Ra) strain of Mtb were equally effective in inducing apoptosis. Pretreatment of neutrophils with antioxidants or an inhibitor of NADPH oxidase markedly blocked Mtb-induced apoptosis but did not affect spontaneous apoptosis. Activation of caspase-3 was evident in neutrophils undergoing spontaneous apoptosis, but it was markedly augmented and accelerated during Mtb-induced apoptosis. The Mtb-induced apoptosis was associated with a speedy and transient increase in expression of Bax protein, a proapoptotic member of the Bcl-2 family, and a more prominent reduction in expression of the antiapoptotic protein Bcl-x(L). Pretreatment with an inhibitor of NADPH oxidase distinctly suppressed the Mtb-stimulated activation of caspase-3 and alteration of Bax/Bcl-x(L) expression in neutrophils. These results indicate that infection with Mtb causes ROS-dependent alteration of Bax/Bcl-x(L) expression and activation of caspase-3, and thereby induces apoptosis in human neutrophils. Moreover, we found that phagocytosis of Mtb-induced apoptotic neutrophils markedly increased the production of proinflammatory cytokine TNF-alpha by human macrophages. Therefore, the ROS-dependent apoptosis in Mtb-stimulated neutrophils may represent an important host defense mechanism aimed at selective removal of infected cells at the inflamed site, which in turn aids the functional activities of local macrophages.

Rab5a GTPase regulates fusion between pathogen-containing phagosomes and cytoplasmic organelles in human neutrophils.

Biogenesis of phagolysosomes proceeds through a sequential series of interactions with endocytic organelles, a process known to be regulated by Rab and SNARE proteins. The molecular mechanisms underlying phagosome maturation in neutrophils are, however, not clearly understood. We investigated fusion between phagosomes containing the intracellular pathogen Mycobacterium tuberculosis versus the extracellular pathogen Staphylococcus aureus (designated MCP for mycobacteria-containing phagosome and SCP for S. aureus-containing phagosome) and cytoplasmic compartments in human neutrophils. Western blot analysis of phagosomes isolated after internalisation revealed that lactoferrin (a constituent of secondary granules) and LAMP-1 were incorporated into both SCP and MCP, whereas hck (marker of azurophil granules) interacted solely with SCP. The subcellular distribution of the proteins Rab5a and syntaxin-4 suggested a role in docking of granules and/or endosomes to the target membrane in the neutrophil. We observed that during phagocytosis, Rab5a in GTP-bound form interacted with syntaxin-4 on the membrane of MCP and were retained for up to 90 minutes, whereas the complex was recruited to the SCP within 5 minutes but was selectively depleted from these vacuoles after 30 minutes of phagocytosis. Downregulation of Rab5a by antisense oligonucleotides efficiently reduced the synthesis of Rab5a, the binding of syntaxin-4 to MCP and SCP and the capacity for fusion exhibited by the pathogen-containing phagosomes, but it had no effect on bacteria internalisation. These data indicate that the difference in granule fusion is correlated with a difference in the association of Rab5a and syntaxin-4 with the phagosomes. Intracellular pathogen-containing phagosomes retain Rab5a and syntaxin-4, whereas extracellular pathogen-containing phagosomes bind briefly to this complex. These results also identified Rab5a as a key regulator of phagolysosome maturation in human neutrophils.