Perspectives for personalized therapy for patients with multidrug-resistant tuberculosis

According to the World Health Organization (WHO), tuberculosis is the leading cause of death attributed to a single microbial pathogen worldwide. In addition to the large number of patients affected by tuberculosis, the emergence of Mycobacterium tuberculosis drug-resistance is complicating tuberculosis control in many high-burden countries. During the past 5 years, the global number of patients identified with multidrug-resistant tuberculosis (MDR-TB), defined as bacillary resistance at least against rifampicin and isoniazid, the two most active drugs in a treatment regimen, has increased by more than 20% annually. Today we experience a historical peak in the number of patients affected by MDR-TB. The management of MDR-TB is characterized by delayed diagnosis, uncertainty of the extent of bacillary drug-resistance, imprecise standardized drug regimens and dosages, very long duration of therapy and high frequency of adverse events which all translate into a poor prognosis for many of the affected patients. Major scientific and technological advances in recent years provide new perspectives through treatment regimens tailor-made to individual needs. Where available, such personalized treatment has major implications on the treatment outcomes of patients with MDR-TB. The challenge now is to bring these adances to those patients that need them most.

Detection limit of Mycobacterium chimaera in water samples for monitoring medical device safety: insights from a pilot experimental series

BACKGROUND

A growing number of Mycobacterium chimaera infections after cardiosurgery have been reported by several countries. These potentially fatal infections were traced back to contaminated heater-cooler devices (HCDs), which use water as a heat transfer medium. Aerosolization of water contaminated with M. chimaera from HCDs enables airborne transmission to patients undergoing open chest surgery. Infection control teams test HCD water samples for mycobacterial growth to guide preventive measures. The detection limit of M. chimaera in water samples, however, has not previously been investigated.

AIM

To determine the detection limit of M. chimaera in water samples using laboratory-based serial dilution tests.

METHODS

An M. chimaera strain representative of the international cardiosurgery-associated M. chimaera outbreak was used to generate a logarithmic dilution series. Two different water volumes, 50 and 1000mL, were inoculated, and, after identical processing (centrifugation, decantation, and decontamination), seeded on mycobacteria growth indicator tube (MGIT) and Middlebrook 7H11 solid media.

FINDINGS

MGIT consistently showed a lower detection limit than 7H11 solid media, corresponding to a detection limit of ≥1.44 × 10⁴cfu/mL for 50mL and ≥2.4cfu/mL for 1000mL water samples. Solid media failed to detect M. chimaera in 50mL water samples.

CONCLUSION

Depending on water volume and culture method, major differences exist in the detection limit of M. chimaera. In terms of sensitivity, 1000mL water samples in MGIT media performed best. Our results have important implications for infection prevention and control strategies in mitigation of the M. chimaera outbreak and healthcare water safety in general.

Anxiety, depression and quality of life in family caregivers of palliative cancer patients during home care and after the patient's death

We examined psychological parameters in family caregivers of palliative cancer patients before and after the death of the patients. Caregivers' data about depression and anxiety (Hospital Anxiety and Depression Scale), quality-of-life (Short Form-8 Health Survey), and social support (Oslo Social Support Scale) were collected at the beginning of home care (t1) and 2 months after the patient had died (t2). Regression models were employed to examine factors related to depression and anxiety in the bereaved caregivers. We interviewed 72 relatives, who were the primary caregiver of a patient. One-third (31.9%) of caregivers had high anxiety levels and 29.2% had high depression levels (t1, cut-off = 10). At t2, anxiety and depression had decreased significantly. There were no changes in quality-of-life over time. At both points of assessments, quality-of-life was lower than in the general population. Relevant factors for higher anxiety and depression in the bereaved caregivers were high levels of distress at t1, insufficient social support and low physical function. Bereaved caregivers were particularly depressed when they had been the spouse of the patient. Healthcare professionals should consider social isolation of caring relatives both during homecare and afterwards. Thus, it seems to be important to routinely offer support to spouses.

Psychological distress and adjustment to disease in patients before and after radical prostatectomy. Results of a prospective multi-centre study

The aim of this prospective multi-centre study was to evaluate the level of psychological distress (PD) and adjustment to disease in patients who underwent radical prostatectomy. Furthermore, the impact of urinary incontinence and erectile dysfunction on PD was assessed. Anxiety, depression and PD were evaluated using the Hospital Anxiety and Depression Scale in 329 prostate cancer patients before surgery as well as 3, 6 and 12 months after surgery. These results were compared with those of a male German general population reference group. Adjustment to disease was assessed using the Perceived Adjustment to Chronic Illness Scale. Patients reported low levels of PD at all points of assessment similar to population norms of age-matched German men. Persistent PD was seen in about 8% of the patients and 20% had PD at least two of the measurement points. Relevant predictors for PD after surgery were urinary symptoms and baseline PD. Adjustment to disease was highest before surgery and had significantly reduced at 3 and 6 months after surgery. In general, men are resilient to the experience of localised prostate cancer and adjust well psychologically after surgery. However, between 8% and 20% of patients could possibly benefit from mental health support.

Distribution of repetitive DNAs and the hybrid origin of the red vizcacha rat (Octodontidae)

Great genome size (GS) variations described in desert-specialist octodontid rodents include diploid species ( Octomys mimax and Octodontomys gliroides ) and putative tetraploid species ( Tympanoctomys barrerae and Pipanacoctomys aureus ). Because of its high DNA content, elevated chromosome number, and gigas effect, the genome of T. barrerae is claimed to have resulted from tetraploidy. Alternatively, the origin of its GS has been attributed to the accumulation of repetitive sequences. To better characterize the extent and origin of these repetitive DNA, self-genomic in situ hybridization (self-GISH), whole-comparative genomic hybridization (W-CGH), and conventional GISH were conducted in mitotic and meiotic chromosomes. Self-GISH on T. barrerae mitotic plates together with comparative self-GISH (using its closest relatives) discriminate a pericentromeric and a telomeric DNA fraction. As most of the repetitive sequences are pericentromeric, it seems that the large GS of T. barrerae is not due to highly repeated sequences accumulated along chromosomes arms. W-CGH using red-labeled P. aureus DNA and green-labeled O. mimax DNA simultaneously on chromosomes of T. barrerae revealed a yellow-orange fluorescence over a repetitive fraction of the karyotype. However, distinctive red-only fluorescent signals were also detected at some centromeres and telomeres, indicating closer homology with the DNA sequences of P. aureus. Conventional GISH using an excess of blocking DNA from either P. aureus or O. mimax labeled only a fraction of the T. barrerae genome, indicating its double genome composition. These data point to a hybrid nature of the T. barrerae karyotype, suggesting a hybridization event in the origin of this species.

[Premature immunosenescence: a pathogenetic factor in Alzheimer's disease?]

While the familial form of Alzheimer's disease (AD) is known to be entirely inherited, the etiopathogenesis of the most common late-onset form of Alzheimer's disease still remains unresolved. Among various factors, aging seems to be one of the most prominent risk factors. Moreover, a large body of evidence points to the contribution of immunological alterations in AD. The involvement of inflammatory factors in the etiopathology has been widely discussed. Moreover, an impairment of certain immune responses in AD has been observed. Presumably, premature immunosenescence may lead to inadequate immune reactions. Against this background, the development of different immunotherapeutic strategies seems to be a promising challenge for future research.

Expression levels of Activated Leukocyte Cell Adhesion Molecule (ALCAM/CD166) in primary breast carcinoma and distant breast cancer metastases

Introduction: Activated Leukocyte Cell Adhesion Molecule (ALCAM/CD166) gained increasing attention regarding tumorprogression and metastatic spread in breast cancer. The aim of this study was to examine ALCAM expression levels in primary breast cancer and distant metastases of the same patient within 29 autopsy cases to better understand the underlying mechanisms of metastases and the role of adhesion molecules in this process.

Material and Methods: Paraffin-embedded tissue of the primary and distant metastases (N = 84) were collected and ALCAM immunohistochemistry was performed.

Results: The primary tumor and all metastases showed a statistically normally distributed ALCAM expression. ALCAM expression level average differs between immunoreactive score (IRS) (mean) 4.16 (lung)-5.00 (adrenal gland). Of the metastatic ALCAM expression levels we obtained an intra-class correlation (ICC) of 80.9%, indicating a strong cluster effect of measurements in the same patient. ALCAM expression scores in metastatic sites and in the primary analyzed by hierarchical regression analysis showed that ALCAM expression in the primary is prognostic for ALCAM expression in all different sites of metastases (slope = 0.773, p < 0.001, r² = 0.504).

Conclusion: ALCAM expression in the primary is positively correlated to ALCAM expression in metastases within one single patient. This could show a tumorbiological context of ALCAM for the development of metastases in breast cancer.

Microscopic diagnosis of sodium acetate-acetic acid-formalin-fixed stool samples for helminths and intestinal protozoa: a comparison among European reference laboratories

The present study aimed to compare the diagnostic performance of different European reference laboratories in diagnosing helminths and intestinal protozoa, using an ether-concentration method applied to sodium acetate-acetic acid-formalin (SAF)-preserved faecal samples. In total, 102 stool specimens were analysed during a cross-sectional parasitological survey in urban farming communities in Côte d'Ivoire. Five SAF-preserved faecal samples were prepared from each specimen and forwarded to the participating reference laboratories, processed and examined under a microscope adhering to a standard operating procedure (SOP). Schistosoma mansoni (cumulative prevalence: 51.0%) and hookworm (cumulative prevalence: 39.2%) were the predominant helminths. There was excellent agreement (kappa > 0.8; p < 0.001) among the reference laboratories for the diagnosis of S. mansoni, hookworm, Trichuris trichiura and Ascaris lumbricoides. Moderate agreement (kappa = 0.54) was found for Hymenolepis nana, and lesser agreement was observed for other, less prevalent helminths. The predominant intestinal protozoa were Entamoeba coli (median prevalence: 67.6%), Blastocystis hominis (median prevalence: 55.9%) and Entamoeba histolytica/Entamoeba dispar (median prevalence: 47.1%). Substantial agreement among reference laboratories was found for E. coli (kappa = 0.69), but only fair or moderate agreement was found for other Entamoeba species, Giardia intestinalis and Chilomastix mesnili. There was only poor agreement for B. hominis, Isospora belli and Trichomonas intestinalis. In conclusion, although common helminths were reliably diagnosed by European reference laboratories, there was only moderate agreement between centres for pathogenic intestinal protozoa. Continued external quality assessment and the establishment of a formal network of reference laboratories is necessary to further enhance both accuracy and uniformity in parasite diagnosis.

Isolation of flavanol-anthocyanin adducts by countercurrent chromatography

Pigments of the flavanol-anthocyanin (F-A+) type detected earlier in wine are synthesized using a protocol adapted from the synthesis of procyanidin dimers. The F-A+ adduct thus obtained is purified by countercurrent liquid-liquid partition, currently referred to as countercurrent chromatography (CCC). The solvent system consists of tert-butyl methyl ether-n-butanol-acetonitrile-water (2:2:1:5, acidified with 0.1% trifluoroacetyl) with the light organic phase acting as a stationary phase and the aqueous phase as the mobile phase. Four fractions are recovered and analyzed by high-performance liquid chromatography coupled to a diode-array detector and electrospray ionization mass spectrometer. The multilayer CCC method allowed the separation of pigments in three different groups. The first group consists of hydrosoluble pigments present in fraction 1; the second group consists of the F-A+ adducts [catechin-malvidin 3 glucoside (Mv3glc), along with some (catechin)2-Mv3glc]; and the third group is their anthocyanin precursor, Mv3glc.

Large-scale isolation of flavan-3-ol phloroglucinol adducts by high-speed counter-current chromatography

Flavan-3-ol phloroglucinol adducts were synthesised through acid catalysed degradation of a procyanidins-rich grape seed extract in the presence of phloroglucinol. The reaction mixture (3.3 g) was fractionated without further sample preparation using the all-liquid chromatographic technique of high-speed counter-current chromatography (HSCCC). Selected solvent systems were hexane-ethyl acetate-methanol-water (0.1:5:0.1:5, v/v/v/v) and (1.5:10:1.5:10, v/v/v/v). The fractions obtained were found to contain almost pure compounds, in some cases final purification was achieved by preparative HPLC. The so-obtained pure standards of (+)catechin-(4alpha-->2)-phloroglucinol, (-)epicatechin-(4beta-->2)-phloroglucinol, (+)catechine, (-)epicatechin-3-O-galloyl-(4beta-->2)-phloroglucinol, (-)epicatechin, and (-)epicatechin gallate are required for quantification of acid-catalysed phloroglucinol degradation products of procyanidins.

[Patients as partners. Tumor patients and their participation in medical decisions]

Between March 2002 and August 2003 as part of the research project "Patients as partners -- tumour patients and their participation in medical decisions" tumour patients undergoing palliative therapy (n=272) were interviewed and asked about their level of information, their desired place to die and whether they had prepared an advance directive. Furthermore, 72 relatives of deceased patients who had been looked after by the project's palliative care team were given a similar questionnaire including questions concerning their knowledge about disease and prognosis, the actual place of death and the relevance of advance directives. According to patients and relatives, information particularly about prognosis is unsatisfactory. Of the inter-viewed patients, 75% said they wanted to die at home and 15% in a hospital. According to their relatives, 36% of the patients looked after by the palliative care team had an advance directive. The survey of the relatives showed a significant relation between the preparation of an advance directive and dying at the desired place. According to the relatives, medical and health reasons, hope for an improvement up to the very end,acute worsening of the condition and deficits in medical care were important reasons for dying in hospital against the patient'swish. In future, advance directives should be used as an aid for communication and the planning of care. Therefore, cooperation between doctors and patients based on a partnership is necessary. The required competence in communication should be improved.

Gradual and quantum genome size shifts in the hystricognath rodents

We assessed genome size variation by flow cytometry within and among 31 species of nine families of African and South American hystricognath rodents. Interspecific variation was extensive and genome size was relatively high among the South American radiation whereas only moderate variation and smaller estimates of genome size were observed in the African counterparts. The largest genome size, indicating tetraploidy was recorded in the South American octodontid, Tympanoctomys barrerae (16.8 pg DNA). This quantum shift in DNA content represents a novel mechanism of genome evolution in mammals. As expected in polyploid organisms, varying nucleotypic effects were observed in the dimensions of the sperm cells and lymphocytes of T. barrerae. The role of control mechanisms that influence cell dimensions in polyploid organisms is discussed.

Protein A is the von Willebrand factor binding protein on Staphylococcus aureus

Endovascular infection is a highly critical complication of invasive Staphylococcus aureus disease. For colonization, staphylococci must first adhere to adhesive endovascular foci. Von Willebrand factor (vWF) is a large, multimeric glycoprotein mediating platelet adhesion at sites of endothelial damage. Earlier it was demonstrated that vWF binds to and promotes the surface adhesion of S. aureus, prompting this effort to identify the vWF adhesin. In Western ligand assays of S. aureus lysates, staphylococcal protein A (SPA) was recognized by purified vWF. Surface plasmon resonance demonstrated the binding of soluble vWF to immobilized recombinant protein A with a K(d) of 1.49 x 10(-8) mol/L. Using flow cytometry, the binding of fluorescein isothiocyanate-labeled vWF to S. aureus was found to be saturable and inhibitable by unlabeled vWF, antiprotein-A antibodies, or IgG. Isogenic Deltaspa::Tc(r) mutants were constructed by the insertion of a tetracycline resistance cassette into spa using allelic replacement, and it exhibited decreased binding of soluble vWF and decreased adhesion to vWF-adsorbed surfaces. The interaction was restored on complementation of the mutants with spa-containing plasmid pSPA7235. In conclusion, protein A confers interaction of S. aureus with soluble and immobilized vWF in a newly discovered function characterizing protein A as a novel member of the staphylococcal surface protein adhesin superfamily and suggesting its potential role in the pathogenesis of endovascular staphylococcal disease.

Protective role of endogenous carbon monoxide in hepatic microcirculatory dysfunction after hemorrhagic shock in rats

Maintenance of hepatic microcirculatory flow after ischemia of the liver is essential to prevent hepatic dysfunction. Thus, we determined the differential role of carbon monoxide (CO) and nitric oxide (NO) in the intrinsic control of sinusoidal perfusion, mitochondrial redox state, and bile production in the isolated perfused rat liver after hemorrhagic shock. Administration of tin protoporphyrin-IX (50 microM), a specific inhibitor of the CO generating enzyme heme oxygenase, caused a decrease in sinusoidal flow that was more pronounced after shock compared with sham shock, as determined by in situ epifluorescence microscopy. This was associated with a shift in hepatocellular redox potential to a more reduced state (increased fluorescence intensity of reduced pyridine nucleotides in hepatocytes, decreased acetoacetate/beta-hydroxybutyrate ratio in the perfusate) and a profound reduction in bile flow. In sharp contrast, the preferential inhibitor of the inducible isoform of NO synthase S-methylisothiourea sulfate (100 microM) did not affect sinusoidal flow, hepatic redox state, or function. This indicates that 1.) endogenously generated CO preserves sinusoidal perfusion after hemorrhagic shock, 2.) protection of the hepatic microcirculation by CO may serve to limit shock-induced liver dysfunction, and 3.) in contrast to CO, inducible NO synthase-derived NO is of only minor importance for the intrinsic control of hepatic perfusion and function under these conditions.

Chromosomal analysis of gregarious oviposition by Drosophila melanogaster

The contribution of different chromosomes to variation in the gregarious oviposition behavior of Drosophila melanogaster females was elucidate by a chromosome substitution analysis. Lines of D. melanogaster previously selected for more than 190 generations for high or low levels of gregarious oviposition were crossed to a tester strain having genetically marked inversion-containing chromosomes. Genes influencing gregarious oviposition behavior are distributed over chromosome II and III. Interactions among the chromosomes were negligible as measured in this experiment. The differences in the gregarious oviposition performance of these two selected lines is due mainly to the accumulation of factors for high gregarious oviposition on chromosomes II and factors for low gregarious oviposition on chromosome III.