Evaluation of the microbiota-sparing properties of the anti-staphylococcal antibiotic afabicin

BACKGROUND

Antibiotic use is associated with collateral damage to the healthy microbiota. Afabicin is a first-in-class prodrug inhibitor of the FabI enzyme that, when converted to the pharmacologically active agent afabicin desphosphono, demonstrates a staphylococcal-specific spectrum of activity. An expected benefit of highly targeted antibiotics such as afabicin is microbiome preservation.

OBJECTIVES

To compare the effects of oral treatment with afabicin and standard-of-care antibiotics upon the murine gut microbiota, and to assess the effects of oral afabicin treatment on the human gut microbiota.

METHODS

Gut microbiota effects of a 10 day oral course of afabicin treatment were monitored in mice and compared with clindamycin, linezolid and moxifloxacin at human-equivalent dose levels using 16S rDNA sequencing. Further, the gut microbiota of healthy volunteers was longitudinally assessed across 20 days of oral treatment with afabicin 240 mg twice daily.

RESULTS

Afabicin treatment did not significantly alter gut microbiota diversity (Shannon H index) or richness (rarefied Chao1) in mice. Only limited changes to taxonomic abundances were observed in afabicin-treated animals. In contrast, clindamycin, linezolid and moxifloxacin each caused extensive dysbiosis in the murine model. In humans, afabicin treatment was not associated with alterations in Shannon H or rarefied Chao1 indices, nor relative taxonomic abundances, supporting the findings from the animal model.

CONCLUSIONS

Oral treatment with afabicin is associated with preservation of the gut microbiota in mice and healthy subjects.

Using deepfakes for experiments in the social sciences - A pilot study

The advent of deepfakes - the manipulation of audio records, images and videos based on deep learning techniques - has important implications for science and society. Current studies focus primarily on the detection and dangers of deepfakes. In contrast, less attention is paid to the potential of this technology for substantive research - particularly as an approach for controlled experimental manipulations in the social sciences. In this paper, we aim to fill this research gap and argue that deepfakes can be a valuable tool for conducting social science experiments. To demonstrate some of the potentials and pitfalls of deepfakes, we conducted a pilot study on the effects of physical attractiveness on student evaluations of teachers. To this end, we created a deepfake video varying the physical attractiveness of the instructor as compared to the original video and asked students to rate the presentation and instructor. First, our results show that social scientists without special knowledge in computer science can successfully create a credible deepfake within reasonable time. Student ratings of the quality of the two videos were comparable and students did not detect the deepfake. Second, we use deepfakes to examine a substantive research question: whether there are differences in the ratings of a physically more and a physically less attractive instructor. Our suggestive evidence points toward a beauty penalty. Thus, our study supports the idea that deepfakes can be used to introduce systematic variations into experiments while offering a high degree of experimental control. Finally, we discuss the feasibility of deepfakes as an experimental manipulation and the ethical challenges of using deepfakes in experiments.

Raman microscopic spectroscopy as a diagnostic tool to detect Staphylococcus epidermidis in bone grafts

INTRODUCTION

Raman microscopic spectroscopyis a new approach for further characterization and detection of molecular features in many pathological processes. This technique has been successfully applied to scrutinize the spatial distribution of small molecules and proteins within biological systems by in situ analysis. This study uses Raman microscopic spectroscopyto identify any in-depth benefits and drawbacks in diagnosing Staphylococcus epidermidis in human bone grafts.

MATERIAL AND METHODS

40 non-infected human bone samples and 10 human bone samples infected with Staphylococcus epidermidis were analyzed using Raman microscopic spectroscopy. Reflectance data were collected between 200 cm^-1 and 3600 cm^-1 with a spectral resolution of 4 cm^-1 using a Senterra II microscope (Bruker, Ettlingen, Germany). The acquired spectral information was used for spectral and unsupervised classification, such as principal component analysis.

RESULTS

Raman measurements produced distinct diagnostic spectra that were used to distinguish between non-infected human bone samples and Staphylococcus epidermidis infected human bone samples by spectral and principal component analyses. A substantial loss in bone quality and protein conformation was detected by human bone samples co-cultured with Staphylococcus epidermidis. The mineral-to-matrix ratio using the phosphate/Amide I ratio (p = 0.030) and carbonate/phosphate ratio (p = 0.001) indicates that the loss of relative mineral content in bones upon bacterial infection is higher than in non-infected human bones. Also, an increase of alterations in the collagen network (p = 0.048) and a decrease in the structural organization and relative collagen in infected human bone could be detected. Subsequent principal component analyses identified Staphylococcus epidermidis in different spectral regions, respectively, originating mainly from CH₂ deformation (wagging) of protein (at 1450 cm^-1) and bending and stretching modes of C-H groups (∼2800-3000 cm^-1).

CONCLUSION

Raman microscopic spectroscopyis presented as a promising diagnostic tool to detect Staphylococcus epidermidis in human bone grafts. Further studies in human tissues are warranted.

TEMPus VoLA: The timed Epstein multi-pressure vessel at low accelerations

The field of planetary system formation relies extensively on our understanding of the aerodynamic interaction between gas and dust in protoplanetary disks. Of particular importance are the mechanisms triggering fluid instabilities and clumping of dust particles into aggregates, and their subsequent inclusion into planetesimals. We introduce the timed Epstein multi-pressure vessel at low accelerations, which is an experimental apparatus for the study of particle dynamics and rarefied gas under micro-gravity conditions. This facility contains three experiments dedicated to studying aerodynamic processes: (i) the development of pressure gradients due to collective particle-gas interaction, (ii) the drag coefficients of dust aggregates with variable particle-gas velocity, and (iii) the effect of dust on the profile of a shear flow and resultant onset of turbulence. The approach is innovative with respect to previous experiments because we access an untouched parameter space in terms of dust particle packing fraction, and Knudsen, Stokes, and Reynolds numbers. The mechanisms investigated are also relevant for our understanding of the emission of dust from active surfaces, such as cometary nuclei, and new experimental data will help interpreting previous datasets (Rosetta) and prepare future spacecraft observations (Comet Interceptor). We report on the performance of the experiments, which has been tested over the course of multiple flight campaigns. The project is now ready to benefit from additional flight campaigns, to cover a wide parameter space. The outcome will be a comprehensive framework to test models and numerical recipes for studying collective dust particle aerodynamics under space-like conditions.

Charged Residues in the Membrane Anchor of the Pestiviral Erns Protein Are Important for Processing and Secretion of Erns and Recovery of Infectious Viruses

The pestivirus envelope protein E^rns is anchored in membranes via a long amphipathic helix. Despite the unusual membrane topology of the E^rns membrane anchor, it is cleaved from the following glycoprotein E1 by cellular signal peptidase. This was proposed to be enabled by a salt bridge-stabilized hairpin structure (so-called charge zipper) formed by conserved charged residues in the membrane anchor. We show here that the exchange of one or several of these charged residues reduces processing at the E^rns carboxy-terminus to a variable extend, but reciprocal mutations restoring the possibility to form salt bridges did not necessarily restore processing efficiency. When introduced into an E^rns-only expression construct, these mutations enhanced the naturally occurring E^rns secretion significantly, but again to varying extents that did not correlate with the number of possible salt bridges. Equivalent effects on both processing and secretion were also observed when the proteins were expressed in avian cells, which points at phylogenetic conservation of the underlying principles. In the viral genome, some of the mutations prevented recovery of infectious viruses or immediately (pseudo)reverted, while others were stable and neutral with regard to virus growth.

First evidence of SGPL1 expression in the cell membrane silencing the extracellular S1P siren in mammary epithelial cells

The bioactive lipid sphingosine-1-phosphate (S1P) is a main regulator of cell survival, proliferation, motility, and platelet aggregation, and it is essential for angiogenesis and lymphocyte trafficking. In that S1P acts as a second messenger intra- and extracellularly, it might promote cancer progression. The main cause is found in the high S1P concentration in the blood, which encourage cancer cells to migrate through the endothelial barrier into the blood vessels. The irreversible degradation of S1P is solely caused by the sphingosine-1-phosphate lyase (SGPL1). SGPL1 overexpression reduces cancer cell migration and therefore silences the endogenous S1P siren, which promotes cancer cell attraction-the main reason for metastasis. Since our previous metabolomics studies revealed an increased SGPL1 activity in association with successful breast cancer cell treatment in vitro, we further investigated expression and localization of SGPL1. Expression analyses confirmed a very low SGPL1 expression in all breast cancer samples, regardless of their subtype. Additionally, we were able to prove a novel SGPL expression in the cytoplasm membrane of non-tumorigenic breast cells by fusing three independent methods. The general SGPL1 downregulation and the loss of the plasma membrane expression resulted in S1P dependent stimulation of migration in the breast cancer cell lines MCF-7 and BT-20. Not only S1P stimulated migration could be repressed by overexpressing the natural SGPL1 variant not but also more general migratory activity was significantly reduced. Here, for the first time, we report on the SGPL1 plasma membrane location in human, non-malignant breast epithelial cell lines silencing the extracellular S1P siren in vitro, and thereby regulating pivotal cellular functions. Loss of this plasma membrane distribution as well as low SGPL1 expression levels could be a potential prognostic marker and a viable target for therapy. Therefore, the precise role of SGPL1 for cancer treatment should be evaluated.

Synergistic Action of Genistein and Calcitriol in Immature Osteosarcoma MG-63 Cells by SGPL1 Up-Regulation

Background

Phytoestrogens such as genistein, the most prominent isoflavone from soy, show concentration-dependent anti-estrogenic or estrogenic effects. High genistein concentrations (>10 μM) also promote proliferation of bone cancer cells in vitro. On the other hand, the most active component of the vitamin D family, calcitriol, has been shown to be tumor protective in vitro and in vivo. The purpose of this study was to examine a putative synergism of genistein and calcitriol in two osteosarcoma cell lines MG-63 (early osteoblast), Saos-2 (mature osteoblast) and primary osteoblasts.

Methods

Thus, an initial screening based on cell cycle phase alterations, estrogen (ER) and vitamin D receptor (VDR) expression, live cell metabolic monitoring, and metabolomics were performed.

Results

Exposure to the combination of 100 μM genistein and 10 nM calcitriol reduced the number of proliferative cells to control levels, increased ERß and VDR expression, and reduced extracellular acidification (40%) as well as respiratory activity (70%), primarily in MG-63 cells. In order to identify the underlying cellular mechanisms in the MG-63 cell line, metabolic profiling via GC/MS technology was conducted. Combined treatment significantly influenced lipids and amino acids preferably, whereas metabolites of the energy metabolism were not altered. The comparative analysis of the log2-ratios revealed that after combined treatment only the metabolite ethanolamine was highly up-regulated. This is the result: a strong overexpression (350%) of the enzyme sphingosine-1-phosphate lyase (SGPL1), which irreversibly degrades sphingosine-1-phosphate (S1P), thereby, generating ethanolamine. S1P production and secretion is associated with an increased capability of migration and invasion of cancer cells.

Conclusion

From these results can be concluded that the tumor promoting effect of high concentrations of genistein in immature osteosarcoma cells is reduced by the co-administration of calcitriol, primarily by the breakdown of S1P. It should be tested whether this anti-metastatic pathway can be stimulated by combined treatment also in metastatic xenograft mice models.

Glucose- but not rice-based oral rehydration therapy enhances the production of virulence determinants in the human pathogen Vibrio cholerae

Despite major attempts to prevent cholera transmission, millions of people worldwide still must address this devastating disease. Cholera research has so far mainly focused on the causative agent, the bacterium Vibrio cholerae, or on disease treatment, but rarely were results from both fields interconnected. Indeed, the treatment of this severe diarrheal disease is mostly accomplished by oral rehydration therapy (ORT), whereby water and electrolytes are replenished. Commonly distributed oral rehydration salts also contain glucose. Here, we analyzed the effects of glucose and alternative carbon sources on the production of virulence determinants in the causative agent of cholera, the bacterium Vibrio cholerae during in vitro experimentation. We demonstrate that virulence gene expression and the production of cholera toxin are enhanced in the presence of glucose or similarly transported sugars in a ToxR-, TcpP- and ToxT-dependent manner. The virulence genes were significantly less expressed if alternative non-PTS carbon sources, including rice-based starch, were utilized. Notably, even though glucose-based ORT is commonly used, field studies indicated that rice-based ORT performs better. We therefore used a spatially explicit epidemiological model to demonstrate that the better performing rice-based ORT could have a significant impact on epidemic progression based on the recent outbreak of cholera in Haiti. Our results strongly support a change of carbon source for the treatment of cholera, especially in epidemic settings.

Cholera research has so far mainly focused on the causative agent, the bacterium Vibrio cholerae, or on disease treatment, but rarely were results from both fields interconnected. Indeed, the treatment of this severe diarrheal disease is mostly accomplished by oral rehydration therapy (ORT). ORT aims at rehydrating patients through the provision of water and oral rehydration salts; the latter being composed of electrolytes as well as glucose as a carbon source. Although glucose-based ORS is commonly used to treat diarrheal diseases and is recommended by the WHO, field studies on cholera indicated that rice-based ORT performs better than glucose-based ORT. Here, we investigated the impact that glucose, starch, or other carbon sources exert on V. cholerae. We demonstrated that glucose leads to an increased expression of the major virulence genes in the pathogen and, accordingly, to an enhanced production of cholera toxin during in vitro experimentation. Because the cholera toxin is primarily responsible for the severe symptoms that are associated with the disease, our study highlights the negative effects of glucose-based ORT. Next, we used a spatially explicit epidemiological model to demonstrate that the better performing rice-based ORS could have a significant impact on epidemic progression based on the recent outbreak of cholera in Haiti.

Pro-apoptotic and anti-adhesive effects of four African plant extracts on the breast cancer cell line MCF-7

Background

Jatropha curcas (JCP1), Pyrenacantha staudtii (PS), Picralima nitida (ZI) and Jatropha gossypifolia (JCP2) are plants used in the African folklore for the treatment of various cancers.

Methods

This study investigated the in vitro anticancer effects of the ethanol extracts against human epithelial MCF-7 breast cancer cells in a dose-dependent manner (1–50 μg/ml) by using cell cycle analysis, viability assay, annexin V/PI staining, TUNEL method and expression determination of apoptotic and adhesion relevant proteins. Adhesion processes were monitored by detachment via flow cytometry, β1-integrin expression and formation of the actin cytoskeleton.

Results

The three extracts, termed PS, JCP1 and JCP2 at a concentration of 10 μg/ml induced cell death in MCF-7 breast cancer cells verified by high amounts of PI-positive cells in the cell cycle analysis, Annexin V/PI staining and DNA fragmentation measurements. In parallel cell detachment was accompanied by decreased β1- integrin expression and phosphorylation of the focal adhesion kinase at Tyr397. ZI extract was the exception by the increasing β1-integrin expression and strengthening the cortical actin cytoskeleton. However, all four plant extracts mediated strong anti-cancer properties with IC₅₀ values between 23–38 μg/ml.

Conclusion

PS, JCP1 and JCP2 were found to be very active against MCF-7 cells by inducing anoikis and therefore possessing vast potential as medicinal drugs especially in estrogen receptor positive breast cancer treatment. ZI mediated their anti-cancer action by different signaling mechanisms which should be analyzed in future studies. Our results further supported the idea that medicinal plants can be promising sources of putative anticancer agents.

Electronic supplementary material

The online version of this article (doi:10.1186/1472-6882-14-334) contains supplementary material, which is available to authorized users.

Bactofilins, a ubiquitous class of cytoskeletal proteins mediating polar localization of a cell wall synthase in Caulobacter crescentus

The cytoskeleton has a key function in the temporal and spatial organization of both prokaryotic and eukaryotic cells. Here, we report the identification of a new class of polymer-forming proteins, termed bactofilins, that are widely conserved among bacteria. In Caulobacter crescentus, two bactofilin paralogues cooperate to form a sheet-like structure lining the cytoplasmic membrane in proximity of the stalked cell pole. These assemblies mediate polar localization of a peptidoglycan synthase involved in stalk morphogenesis, thus complementing the function of the actin-like cytoskeleton and the cell division machinery in the regulation of cell wall biogenesis. In other bacteria, bactofilins can establish rod-shaped filaments or associate with the cell division apparatus, indicating considerable structural and functional flexibility. Bactofilins polymerize spontaneously in the absence of additional cofactors in vitro, forming stable ribbon- or rod-like filament bundles. Our results suggest that these structures have evolved as an alternative to intermediate filaments, serving as versatile molecular scaffolds in a variety of cellular pathways.

[Atypical vascular supply from the coeliac trunk. Recurrent bleeding from a duodenal ulcer]

Hemorrhagic duodenal ulcers should primarily be controlled by endoscopy. In cases of recurrent bleeding or if bleeding cannot be controlled endoscopically, open surgery is the gold standard. Rarely, atypical origin of arteries or additional atypical arteries may lead to further unexpected hemorrhagic recurrences and angiography with surgical intervention is the treatment of choice. In this article a rare case of an atypical visceral artery connecting the coeliac trunk and the gastroduodenal artery leading to recurrent bleeding from a duodenal ulcer is presented.

Viral reactivation is not related to septic complications after major surgical resections

Anastomotic leakage and septic complications are the most important determinants of postoperative outcome after major surgical resections. Malignant diseases and surgical trauma can influence immune responses and the ability to react against infectious factors, such as bacteria and viruses. Comparable immune suppression can cause viral reactivation in transplantation and trauma patients. In this prospective study, patients who underwent major surgical resections for oesophageal or pancreatic cancer were investigated for the potential involvement of viral reactivation in the development of septic complications. 86 patients (40 oesophageal resections, 27 pancreatic resections, 19 surgical explorations) were included. Viral antigens, viral DNA, antibodies against viral structures (IgG, IgM, IgA) and, in part, viral cultivation were performed for CMV, EBV, HSV1, HSV2, HZV6 and VZV in serum, urine, sputum and swabs from buccal mucosa preoperatively and at postoperative days 1, 3 and 5. Test results were compared with the postoperative outcome (30-day morbidity, in-hospital mortality) and clinical scores (SOFA, TISS). For statistical analyses Student's t-tests and Chi2-tests were used. The overall complication rate was 19.8% (30-day morbidity) with an in-hospital mortality of 1.2% (1/86 patients). Postoperatively, anti-CMV-IgG titres were significantly reduced (p<0.05) and remained suppressed in patients with septic complications. Anti-CMV-gB-IgG were also reduced, but showed considerable interindividual differences. Anti-CMV-IgA and -IgM did not show significant alterations in the postoperative course. In addition, direct viral detection methods did not support viral reactivation in patients in any of the investigated groups. The reduction of anti-CMV antibodies is likely caused by an immune suppression, specifically by reduced B-cell counts after major surgical interventions. Viral reactivation, however, did not occur in the early postoperative period as a specific risk for septic complications.

On the complex three-dimensional amplitude point spread function of lenses and microscope objectives: theoretical aspects, simulations and measurements by digital holography

The point spread function is widely used to characterize the three-dimensional imaging capabilities of an optical system. Usually, attention is paid only to the intensity point spread function, whereas the phase point spread function is most often neglected because the phase information is not retrieved in noninterferometric imaging systems. However, phase point spread functions are needed to evaluate phase-sensitive imaging systems and we believe that phase data can play an essential role in the full aberrations' characterization. In this paper, standard diffraction models have been used for the computation of the complex amplitude point spread function. In particular, the Debye vectorial model has been used to compute the amplitude point spread function of x63/0.85 and x100/1.3 microscope objectives, exemplifying the phase point spread function specific for each polarization component of the electromagnetic field. The effect of aberrations on the phase point spread function is then analyzed for a microscope objective used under nondesigned conditions, by developing the Gibson model (Gibson & Lanni, 1991), modified to compute the three-dimensional amplitude point spread function in amplitude and phase. The results have revealed a novel anomalous phase behaviour in the presence of spherical aberration, providing access to the quantification of the aberrations. This work mainly proposes a method to measure the complex three-dimensional amplitude point spread function of an optical imaging system. The approach consists in measuring and interpreting the amplitude point spread function by evaluating in amplitude and phase the image of a single emitting point, a 60-nm-diameter tip of a Near Field Scanning Optical Microscopy fibre, with an original digital holographic experimental setup. A single hologram gives access to the transverse amplitude point spread function. The three-dimensional amplitude point spread function is obtained by performing an axial scan of the Near Field Scanning Optical Microscopy fibre. The phase measurements accuracy is equivalent to lambda/60 when the measurement is performed in air. The method capability is demonstrated on an Achroplan x20 microscope objective with 0.4 numerical aperture. A more complete study on a x100 microscope objective with 1.3 numerical aperture is also presented, in which measurements performed with our setup are compared with the prediction of an analytical aberrations model.

N-Terminal pyrazinones: a new class of peptide-bound advanced glycation end-products

The reaction of peptide Gly-Ala-Phe with the alpha-dicarbonyl compounds glyoxal and methylglyoxal was studied under physiological conditions (pH=7.4, 37 degrees C). Using HPLC with UV and fluorescence detection, a rapid derivatization of the peptide and the concomitant formation of well-defined products were observed. The products, which showed characteristic UV absorbance (lambda(max)=320 to 340 nm) and fluorescence (lambda(ex)=330 to 340 nm, lambda(em)=395 to 405 nm), were identified by ESI-MS and NMR spectroscopic analysis as the N-terminally pyrazinone-modified peptides I (N-[2-(2-oxo-2H-pyrazin-1-yl)-propyl]-phenylalanine) and II (N-[2-(5-methyl-2-oxo-2H-pyrazin-1-yl)-propionyl]-phenylalanine). Model experiments revealed that the reactivity of the N-termini of peptides towards a derivatization by glyoxal is in the same order of magnitude as that of arginine, which generally is attributed as main target for alpha-dicarbonyl compounds in proteins. Incubation of insulin with glyoxal proved the protein-bound formation of pyrazinones, with the N-terminus of the B-chain as the main target. According to these results, we conclude that N-terminal pyrazinones represent a new type of advanced glycation end-products (AGEs) with significance for biological systems and foods.

[Ecthyma contagiosum (Orf) as an uncommon differential diagnosis of infections of the hand]

Orf of the hand is considered as an uncommon viral infection which is usually acquired through contact with infected sheep and goats. Indirect infections through contaminated knives or meat have been reported. Many authors feel that the disorder is more common than reported because the disease is often misdiagnosed and the course is usually self-limiting with spontaneous healing within several weeks. Diagnosis is mainly made by patient's history and clinical course. It is important to know the benign nature of human orf, since complications seem to be caused by overtreatment.

[Vena cava filter--prevention of pulmonary embolism. Report of clinical experiences]

Between 1982 and 1997 inferior vena cava filters were implanted in 182 patients. Indications were recurrent pulmonary embolism, massive embolism and prophylactic use prior to planned high-risk-operations upon patients with thromboembolic complications in shorter history. Kimray-Greenfield, Cardial and Vascor-systems were implanted. Mortality was 0, neither relevant bleedings, nor infections occurred. Vena-cava-filters prevented from re-embolism in 98%. During hospitalisation 3 cases of re-embolism (1.6%) were noticed due to incorrect filter-placement. One patient died (< 1%). Follow-up-examinations were performed in 74 cases 6 to 24 months after implantation. We discovered 8 cases (11%) of filter-migration, 3 cases (4%) of filter-kinking, one case of filter-perforation and one case of filter-shrut-fracture. All these patients remained without clinical sequelae. Cava-thrombosis was found in 2 patients 6 to 24 months after filter-insertion (2.7%). There was no sign of re-embolism in our longterm follow-up. In our opinion the vena cava filter is an effective and safe method to prevent pulmonary re-embolism. Handling is quite easy and filter complications are low. In some elected cases prophylactic use of vena cava filters in high-risk-patients may be indicated.

Detection of HIV in human vitreous

Assay of human vitreous specimens obtained postmortem for HIV antibodies, or HIV p24 antigen, is reported to be a reliable technique to demonstrate HIV infection in possible cornea donors from whom serum could not be obtained. We tested three vitreous samples obtained during vitrectomy from two HIV-positive patients. One patient exhibited the clinical AIDS syndrome. HIV antigen and antibody tests were negative in all specimens. HIV proviral DNA was detected by PCR only in the vitreous of the patient with AIDS. Therefore, testing only vitreous samples is insufficient to exclude HIV infection in potential cornea donors.

Effect of propranolol and disopyramide on left ventricular function at rest and during exercise in hypertrophic cardiomyopathy

In 19 patients with hypertrophic cardiomyopathy (15 males, 4 females, mean age 49.2 +/- 10.8 years) left ventricular function was studied with radionuclide ventriculography at rest and during exercise in a crossover design without intervention and after disopyramide and propranolol treatment. 15 of the 19 patients had a resting or latent intraventricular gradient of more than 30 mm Hg. Left ventricular function at rest and during exercise was evaluated before medication, 90 min after oral administration of 200 mg disopyramide or 160 mg propranolol and after 3 weeks of oral therapy with disopyramide 200 mg 2 times a day or propranolol 80 mg 4 times a day. After long-term treatment with disopyramide, resting ejection fraction decreased from 72 +/- 12 to 69 +/- 14% (p less than 0.01) and peak ejection rate (PER) decreased from 3.46 +/- 135 to 3.24 +/- 65 end-diastolic volume (EDV).s-1 (p less than 0.01). Peak filling rate (PFR) at rest decreased from 3.01 +/- 0.8 to 2.77 +/- 0.63 EDV.s-1 (p less than 0.05). Time to peak filling rate (TPFR) at rest and during exercise after acute and chronic therapy did not change compared to control values. Acute and long-term administration of propranolol lead to a significant reduction in heart rate at rest and during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comments on so-called "chronic" and "therapy refractory" depression]

The problems of so-called "therapy resistant or chronic" depression has been investigated on own patients of the year 1986, but simply one chronic example could be noticed. Configurations-frequence-analytic research didn't essentially result in significant statements. It is referred to that the frequent occurrence of the so-called "therapy resistant" depressions described by some authors, could be in connection with limited diagnosis inventories and insufficient to the personality orientated therapy regime.

Frequent detection of antibodies to hepatitis B virus x-protein in acute, chronic and resolved infections

Recombinant MS2- or beta gal fusion proteins containing parts of hepatitis B virus (HBV) HBx-, HBc-, and HBs-amino acid sequences were expressed in Escherichia coli and were used to screen 96 and 60 serum samples of HBV infected and uninfected patients, respectively, for the corresponding antibodies by immunoblotting. Antibodies against HBx were detected in 20 out of 65 sera of patients with previous resolved HBV-infection, in 3 out of 7 patients with persistent infection, and in 9 out of 24 sera of patients with acute HBV infection. The specificity of the immune reaction was confirmed by competition experiments with MS2- and beta gal-HBx fusion proteins, and by the lack of HBx antibodies in the sera of uninfected patients. Hbs and HBc antibodies were detected less frequently by immunoblotting with recombinant fusion proteins than by a commercial immunoassay. Our results indicate that HBx antibodies are induced early and frequently during HBV infection suggesting that the HBx protein is an early antigenic protein expressed in vivo.

Homology of the HSV-2 "a-sequence" to cellular sequences

Bgl-II fragments of the genome of Herpes simplex virus type 2 (HSV-2) HG-52 were cloned into the vector p-Neo and were used to screen the complete HSV-2 genome for regions cross-hybridizing with the genome of HEL cells. Most extensive cross-hybridizing activity was observed with a 530 bp SstII subfragment of the viral BamHI G DNA-fragment (contained in Bgl II F), which spans the joint and the viral a-sequence. From a lambda-L47 library, a cellular 15 kb HindIII DNA fragment was subcloned in pBR 322 which contained a 1920 bp SstII subfragment having strong cross-hybridizing activity with the 530 bp Sst II fragment of HSV-2 BamHI G. Within this 1920 bp Sst II fragment the cross-hybridizing activity was confined to a 230 bp Bgl I/Hpa II subfragment. This 230 bp fragment (including the flanking sequences) was analyzed in comparison to the viral a-sequence. Sequence data revealed a (G + C) content of 66% in the cellular and 81% in the viral DNA fragment, which is mainly determined by an extremely (G + C) rich 16-fold direct repeat (DR2) at the 5'-end. The homology between both DNA-fragments varies between 56% and 79% within the L-S inversion region. Both sequences, furthermore, show homology to the human c-myc protooncogene.

Human cytomegalovirus replicates in primary human bone marrow cells

As an attempt to elucidate further the pathogenesis of human cytomegalovirus (HCMV) infection the replication of HCMV in primary human bone marrow cells (BMC) has been investigated. It was found that BMC held in culture in general were susceptible to HCMV infection. Compared to human embryonic lung cells, however, the replicative cycle of HCMV AD169 in BMC as determined by the analysis of viral protein and DNA synthesis was delayed and productive virus infection was restricted to a subset of BMC not exceeding 21% of the total cell population. Both of these phenomena may explain the short-term persistence of HCMV in BMC cultures which was observed over 3 months. By experiments with specifically enriched and depleted cell populations and by indirect double immunofluorescence experiments we found that both bone marrow fibroblasts and a subset of bone marrow stem cells supported productive virus infection. The finding that HCMV replicates in early stem cells of the human bone marrow may explain important aspects of the pathogenesis of HCMV infection including the presence of HCMV in peripheral blood leukocytes.

[Laboratory methods for adenoviruses. XI. Determination of hexon and antihexon-IgA in conjunctival secretions using ELISA]

The possibility of a rapid diagnosis of adenovirus conjunctivitis was studied by demonstrating genus-specific adenovirus hexon antigen or antihexon IgA antibodies in conjunctival secretions by an ELISA. Hexon was found in 44% of about 100 patients with adenovirus conjunctivitis, proven by virus isolation, antihexon in 53%, either one or both in 69% of the conjunctival swabs from the acute phase. Hexon was found in the acute phase more frequently, antihexon in the convalescent phase. In patients with conjunctivitis of different etiology no hexon was found, whereas antihexon IgA was found in a few cases.

Isolation and identification of enteric adenoviruses

Thirty-four out of 64 faecal samples with adenovirus particles, as seen by electron microscopy, were found to contain adenovirus 40 or 41 by direct isolation and neutralization in Chang's conjunctival cells, mostly within one week. (Ad40 and 41 candidate viruses are serologically related.) 6 other adenovirus species were isolated; 6 samples gave equivocal results, and 18 were negative. A genus-specific ELISA with an antihexon coat yielded positive results in 40 out of 55 samples; the test failed to identify adenovirus antigen in 10 out of 17 specimens, which were found negative by culture. All of them were negative by immunfluorescence of inoculated Chang cell cultures. Hence the failures are probably due to insufficient amount of virus in the samples. The predominance of only two adenovirus species associated with gastroenteritis in children and the ease of cultivating and identifying them should help to elucidate their etiological significance.