Effect of SARS-CoV-2 antibody screening on participants' attitudes and behaviour: a study of industry workers in Split, Croatia.

OBJECTIVES: To investigate the changes in personal attitudes and behaviour before and after negative serological test results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. STUDY DESIGN: Cross-sectional questionnaire survey. METHODS: A survey questionnaire was conducted with 200 industry workers (68% males and 32% females) who had previously tested negative for SARS-CoV-2 antibodies. The survey examined participants' self-reported general attitudes towards coronavirus disease 2019 (COVID-19), their sense of fear, as well as their behaviour towards protective measures before and after the testing. RESULTS: Participants perceived the disease as a severe health threat and acknowledged that the protective measures were appropriate. Respondents reported a high level of adherence to measures and low level of fear, both before and after the testing. Although these indicators were statistically significantly reduced after the test (P < 0.004), they did not result in irresponsible non-adherence behaviours. Almost all respondents attributed their application of personal protection measures to factors other than the results of serological screening. CONCLUSIONS: Serological tests do not contribute to irresponsible non-adherence behaviours in an environment where protective measures are efficient. However, they may help reduce fear within society and working environments.

Experimental Demonstration of Hadron Beam Cooling Using Radio-Frequency Accelerated Electron Bunches.

Cooling of beams of gold ions using electron bunches accelerated with radio-frequency systems was recently experimentally demonstrated in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Such an approach is new and opens the possibility of using this technique at higher energies than possible with electrostatic acceleration of electron beams. The challenges of this approach include generation of electron beams suitable for cooling, delivery of electron bunches of the required quality to the cooling sections without degradation of beam angular divergence and energy spread, achieving the required small angles between electron and ion trajectories in the cooling sections, precise velocity matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched-beam cooling. Here we report on the first demonstration of cooling hadron beams using this new approach.

Measurement of the Spin Tune Using the Coherent Spin Motion of Polarized Protons in a Storage Ring.

This Letter reports the first spin tune measurement at high energies (24 and 255 GeV) with a driven coherent spin motion. To maintain polarization in a polarized proton collider, it is important to know the spin tune of the polarized proton beam, which is defined as the number of full spin precessions per revolution. A nine-magnet spin flipper has demonstrated high spin-flip efficiency in the presence of two Siberian snakes [H. Huang et al., Phys. Rev. Lett. 120, 264804 (2018).10.1103/PhysRevLett.120.264804]. The spin flipper drives a spin resonance with a given frequency (or tune) and strength. When the drive tune is close to the spin tune, the proton spin direction is not vertical anymore, but precesses around the vertical direction. By measuring the precession frequency of the horizontal component, the spin tune can be precisely measured. A driven coherent spin motion and fast turn-by-turn polarization measurement are keys to the measurement. The vertical spin direction is restored after turning the spin flipper off and the polarization value is not affected by the measurement. The fact that this manipulation preserves the polarization makes it possible to measure the spin tune during the operation of a high energy accelerator.

High Spin-Flip Efficiency at 255 GeV for Polarized Protons in a Ring With Two Full Siberian Snakes.

In polarized proton collision experiments, it is highly advantageous to flip the spin of each bunch of protons during the stores to reduce the systematic errors. Experiments done at energies less than 2 GeV have demonstrated a spin-flip efficiency over 99%. At high energy colliders with Siberian snakes, a single magnet spin flipper does not work because of the large spin tune spread and the generation of multiple, overlapping resonances. A more sophisticated spin flipper, constructed of nine-dipole magnets, was used to flip the spin in the BNL Relativistic Heavy Ion Collider. A special optics choice was also used to make the spin tune spread very small. A 97% spin-flip efficiency was measured at both 24 and 255 GeV. These results show that efficient spin flipping can be achieved at high energies using a nine-magnet spin flipper.

Increased chemotaxis and activity of circulatory myeloid progenitor cells may contribute to enhanced osteoclastogenesis and bone loss in the C57BL/6 mouse model of collagen-induced arthritis.

Our study aimed to determine the functional activity of different osteoclast progenitor (OCP) subpopulations and signals important for their migration to bone lesions, causing local and systemic bone resorption during the course of collagen-induced arthritis in C57BL/6 mice. Arthritis was induced with chicken type II collagen (CII), and assessed by clinical scoring and detection of anti-CII antibodies. We observed decreased trabecular bone volume of axial and appendicular skeleton by histomorphometry and micro-computed tomography as well as decreased bone formation and increased bone resorption rate in arthritic mice in vivo. In the affected joints, bone loss was accompanied with severe osteitis and bone marrow hypercellularity, coinciding with the areas of active osteoclasts and bone erosions. Flow cytometry analysis showed increased frequency of putative OCP cells (CD3- B220- NK1.1- CD11b-/lo CD117+ CD115+ for bone marrow and CD3- B220- NK1.1- CD11b+ CD115+ Gr-1+ for peripheral haematopoietic tissues), which exhibited enhanced differentiation potential in vitro. Moreover, the total CD11b+ population was expanded in arthritic mice as well as CD11b+ F4/80+ macrophage, CD11b+ NK1.1+ natural killer cell and CD11b+ CD11c+ myeloid dendritic cell populations in both bone marrow and peripheral blood. In addition, arthritic mice had increased expression of tumour necrosis factor-α, interleukin-6, CC chemokine ligand-2 (Ccl2) and Ccl5, with increased migration and differentiation of circulatory OCPs in response to CCL2 and, particularly, CCL5 signals. Our study characterized the frequency and functional properties of OCPs under inflammatory conditions associated with arthritis, which may help to clarify crucial molecular signals provided by immune cells to mediate systemically enhanced osteoresorption.

Operational Head-on Beam-Beam Compensation with Electron Lenses in the Relativistic Heavy Ion Collider.

Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider in order to increase the luminosity delivered to the experiments. We discuss the principle of combining a lattice for resonance driving term compensation and an electron lens for tune spread compensation. We describe the electron lens technology and its operational use. To date, the implemented compensation scheme approximately doubled the peak and average luminosities.

Potential predatory journals are colonizing the ICMJE recommendations list of followers.

BACKGROUND: The International Committee of Medical Journal Editors (ICMJE) has expressed its concerns about predatory journals using the list of ICMJE Recommendations (ICMJE-R) followers to "gain the appearance of legitimacy." We assessed the presence of potential predatory journals on the ICMJE-R list and their adherence to ICMJE recommendations. METHODS: A random sample of 350 journals from the estimated 3,100-3,200 biomedical journals listed as ICMJE-R followers was chosen. Data collected from the ICMJE and journal webpages in English were: adherence to six ICMJE-R policies/requirements, year of journal's listing as ICMJE-R follower, discipline covered, publisher and its country of origin and existence of article processing charge. Potential predatory journal was considered as one open access journal not being a member of a recognized listing in COPE, DOAJ, OASPA, AJOL and/or INASP. RESULTS: Thirty-one percent of journals were considered to be potentially predatory; 94% of them were included in the ICMJE-R list in 2014-2018. Half were published in the United States and 62% were devoted to medicine. Adherence to five of the six policies/requirements was infrequent, ranging from 51% (plagiarism) to 7% (trial registration). Seventy-two percent of journals mentioned a policy on authors' conflicts of interest. Information on article processing charge was available for 76% journals and could not be found for 22%. Authorship policy/ instructions were significantly more present in journals with publishers from India than from the USA (53% vs 30%; p = 0.047), with no differences in the other five policies. CONCLUSION: Predatory journals should be deleted from the ICMJE-R list of followers to prevent misleading authors. ICMJE-R following journals need to be reevaluated with pre-defined published criteria.

The completed suicide as interplay of genes and environment.

The review will tackle the interplay of genetic and environmental risk factors behind the completed suicide. First, individual differences in suicidal behaviour in relation to heritability are presented followed by a brief discussion of genetic methods currently used to investigate candidate genes for the completed suicide. Further along the polygenetic, multi-factorial model of genetic proneness to suicidal behaviour is presented as interplay of genes and environment. Finally, the future implications in this quickly blossoming field of research are discussed.

Talc granulomatosis in the rat: the relationship between osteoblast insufficiency and adjacent bone marrow hyperplasia.

Bone loss in talc granulomatosis is paralleled by hyperplasia of bone marrow in the rat. To test the hypothetical relation between those two phenomena, bone matrix osteoinduction was employed as a model in which bone formation and bone marrow appearance are separated in time. Implantation of demineralized bone matrix to normal rats was followed by three talc injections (one weekly), starting 1 week after matrix implantation. Implants of demineralized bone and [3H]thymidine-labeled tibial metaphyses from talc-injected and normal rats were analyzed histologically and evaluated for alkaline and tartrate-resistant acid phosphatase activity on days 7, 14, 21, and 30 after matrix implantation. Analysis of tibial autoradiographs showed a marked growth arrest and bone marrow hyperplasia in talc-injected rats 7 days after first talc injection. Alkaline phosphatase activity in homogenates of bone implants was low in talc-injected rats on day 14 after implantation. Moreover, histology of the bone implants showed numerical and functional inhibition of osteoblasts on the same day, causing marked growth delay. Bone marrow appeared as late as day 21 after bone matrix implantation. We conclude that hyperplasia of the adjacent bone marrow is not the cause of bone loss in talc granulomatosis, but rather its compensatory consequence.

Production of leukemia inhibitory factor mRNA and protein by malignant and immortalized bone cells.

Leukemia inhibitory factor (LIF) is a recently characterized glycoprotein with complex biologic activities on bone cells. We tested various rodent and human immortalized and malignant bone cell lines and primary osteoblast-enriched cell cultures from fetal rat calvarial digests for expression of LIF mRNA and LIF protein. Both human and rodent immortalized and malignant cells expressed a single 4.4 kb mRNA transcript that hybridized to a human LIF cDNA probe in Northern blots. LIF mRNA was undetectable in unstimulated rodent osteoblast-like cells lines MC3T3-E1 and Py1a. However, treatment with LPS (10 micrograms/ml), TGF-beta (1 ng/ml), TNF-alpha (100 ng/ml) or inhibitors of protein synthesis (cycloheximide, emetine, puromycin, and anisomycin) induced the expression of LIF message in these cells. In contrast, primary osteoblast-enriched cells did not express LIF mRNA in Northern blot assays either constitutively or after treatment with TNF-alpha or cycloheximide. The human osteosarcoma cells lines U-2 OS and Saos-2 constitutively expressed LIF mRNA and did not respond to LPS treatment. However, phorbol myristate acetate (PMA), an activator of protein kinase C, was a potent stimulator of LIF message in Saos-2 but not U-2 OS cells. The effects of PMA (0.5 ng/ml) on LIF mRNA in Saos-2 cells were detectable at 1 h and maximal at 6 h. TNF-alpha (100 ng/ml) and inhibitors of protein synthesis also increased LIF mRNA in both Saos-2 and U-2 OS cells. LIF protein was also detected constitutively in the conditioned medium from both Saos and U-2 OS cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Cortisol modulates the actions of interleukin-1 alpha on bone formation, resorption, and prostaglandin production in cultured mouse parietal bones.

Previous studies have shown that both interleukin-1 (IL-1) and glucocorticoids inhibit collagen synthesis in bone organ and cell cultures. In this study we examined their interactions in cultured neonatal mouse parietal bones. IL-1 alpha stimulated [3H]thymidine incorporation. Cortisol decreased thymidine incorporation, but did not block the effect of IL-1. Both cortisol and IL-1 alpha decreased the incorporation of [3H]proline into collagenase-digestible protein (CDP) and reduced alpha 1(I)procollagen mRNA levels at 72 h. Noncollagen protein (NCP) labeling was increased by IL-1 and decreased by cortisol. In the presence of cortisol, IL-1 alpha (6 pM) increased CDP as well as NCP labeling. The increase in CDP labeling was paralleled by an increase in alpha 1(I)procollagen mRNA, suggesting a pretranslational site for the cortisol-IL-1 alpha interaction. In the same bones, cortisol consistently blocked IL-1 alpha-stimulated 45Ca release and prostaglandin E2 (PGE2) production. The ability of IL-1 alpha to increase CDP in the presence of cortisol was the same in the presence or absence of indomethacin, an inhibitor of PGE2 synthesis, or aphidicholin (30 microM), an inhibitor of DNA synthesis, indicating that the reversal was neither PG mediated nor dependent on cell proliferation. In conclusion, our results demonstrate that IL-1 inhibits collagen, but not NCP or DNA, synthesis and that cortisol inhibits IL-1 alpha-induced bone resorption and PGE2 production and reverses its inhibitory effect on collagen synthesis in cultured neonatal mouse calvariae.

Genetic variability of new bone induction in mice.

We studied differences in ectopic osteoinduction in eight mouse inbred strains and an outbred strain. Antigen-extracted autolyzed rat bone gelatin was implanted under hind limb muscle fascia of 12-week-old males, and new bone formation was morphologically assessed on serial sections. Four weeks after implantation, less than half of the implants from CBA/J, A/J, BALB/cJ, and C3Hf/Bu mice showed induction of only cartilage. New cartilage was observed in all, and bone and bone marrow in 80% of the implants from AKR/J, C57BL/6J, DBA/2J, and RFM/Rij mice. Volume of the newly formed tissue ranged from 1.3% of the old matrix in A/J strain to 74.6% in DBA/2J strain. Outbred CD1 mice showed only weak cartilage induction. The "good" responders differed among themselves in the volume and type of newly induced tissue: DBA/2J, RFM/Rij, and AKR/J mice had a similar ratio of new bone and cartilage and abundant bone marrow, whereas the predominant newly induced tissue in C57Bl/6J mice was cartilage. The pattern of the expression of BMP-2, -4, and -7, alkaline phosphatase, osteocalcin, interferon-gamma, and granulocyte-macrophage colony-stimulating factor, measured by reverse transcriptase polymerase chain reaction, did not correlate with the type and the quantity of the newly induced tissue. Our results show that adult mice of inbred strains differ not only in the peak bone mass and morphology, but also ability to form new bone after an osteoinductive stimulus. Ectopic osteoinduction may be a useful in vivo model to investigate genetic determinants of endochondral osteogenesis, especially its immunological component.

Immunohistological and flow cytometric analysis of glycosphingolipid expression in mouse lymphoid tissues.

Expression of neutral glycosphingolipids (GSLs) and gangliosides in normal lymphoid tissues and cells has been studied mostly by biochemical and immunochemical analysis of lipid extracts separated by thin-layer chromatography. GSLs and gangliosides involved in the GM1b biosynthetic pathway were assigned to T-lymphocytes, whereas B-cell gangliosides and GSLs have been poorly characterized in former publications. We used specific polyclonal antibodies in immunohistochemistry and flow cytometry to analyze the distribution of globotriaosylceramide (Gb(3)Cer), globoside (Gb(4)Cer), gangliotriaosylceramide (Gg(3)Cer), gangliotetraosylceramide (Gg(4)Cer), and gangliosides GM3 and GalNAc-GM1b in the mouse thymus, spleen, and lymph node. Immature thymocytes expressed epitopes recognized by all antibodies, except for anti-Gb(4)Cer. Mature thymocytes bound only antibodies to GalNAc-GM1b, Gg(4)Cer, and Gb(4)Cer. In secondary lymphoid organs, antibodies to globo-series GSLs bound to vascular spaces of secondary lymphoid organs, whereas the ganglio-series GSL antibodies recognized lymphocyte-containing regions. In a Western blotting analysis, only GalNAc-GM1b antibody recognized a specific protein band in all three organs. Flow cytometric analysis of spleen and lymph node cells revealed that B-cells carried epitopes recognized by all antibodies, whereas the T-cell GSL repertoire was mostly oriented to ganglio-series-neutral GSLs and GM1b-type gangliosides. The results of immunohistochemistry and flow cytometry were not always identical, possibly because of crossreactivity to glycoprotein-linked oligosaccharides and/or differences between cell surface carbohydrate profiles of isolated cells and cells in a tissue environment.

Search for the CP forbidden decay eta-->4pi(0)

We report the first determination of the upper limit for the branching ratio of the CP forbidden decay eta-->4pi(0). No events were observed in a sample of 3.0x10(7) eta decays. The experiment was performed with the Crystal Ball multiphoton spectrometer installed in a separated pi(-) beam at the AGS (Alternating Gradient Synchrotron). At the 90% confidence limit, B(eta-->4pi(0))

Curricular and extracurricular activities of medical students during war, Zagreb University School of Medicine, 1991-1995.

War, as a major human disaster, affects many aspects of life, including medical education. This report describes curricular and extracurricular activities of the students at the Zagreb University School of Medicine during the wars in Croatia and neighboring Bosnia and Herzegovina. Although condensed versions of the curricula were prepared in case of a major breakdown in civilian life, the school maintained the continuity and quality of its curriculum throughout the war. Students engaged in extracurricular activities related to medical aspects of the war, including organization of resuscitation and first aid courses, collecting medical documentation on war victims, humanitarian help to refugees, and peace-promoting activities. Some students joined mobile surgical teams on the battlefronts. After army service, most of them returned to the school and successfully continued with their studies. The school also accepted guest-students from other new states emerged from former Yugoslavia. The authors found that the students' engagement in extracurricular activities related to medicine was enormously beneficial both to the psychological well-being of the students and to the region's peace-building efforts.

Factor analysis of risk for coronary heart disease: an independent replication.

Eleven risk factors for coronary heart disease were measured on 187 patients with and 187 patients without this disease. Next, factor analysis was performed to identify underlying variables, or factors, that explain the pattern of correlations within a set of observed risk factors. The factor analysis disclosed four factors that explained almost 55% of the variance: a dyslipidaemic and haemostatic complex, a pure hypercholesterolaemia, the metabolic syndrome X, and positive family and medical histories. The four extracted patterns of risk factors did not replicate previous factor analyses of coronary heart disease risk factors, in which the family history of coronary disease on one side and a generalised lack of self-control on the other were suggested. They, however, generated some understanding regarding coronary heart disease risk factors' interactions. Also, results of the present study do encourage efforts to explore new methods designated to bring about more basic forms of personality reorganisation in the realm of self-control, which could in turn have a positive impact on risk factors profile, health status and mortality.

Talc granulomatosis in the rat. Involvement of bone in the acute-phase response.

We investigated the dynamics of the acute-phase response (APR) and osteoblast trabecular surface in rats with subcutaneous inflammation provoked by magnesium silicate (talc). The first visible indicator of the APR was a rapid and profound hypozincemia, paralleled by a decrease in metaphyseal trabecular surfaces covered with osteoblasts in long bones. Both the intensity of serum APR and the decrease in osteoblast trabecular surface were directly proportional to the number of granulomas. Alterations in bone metabolism were specific for the inflammation, whereas mild hypozincemia and decrease in mononuclear and increase in polymorphonuclear peripheral white blood cell fractions developed in animals pair-fed with rats bearing two or four granulomas. Rats with talc granulomatosis had high serum ACTH and corticosterone levels, but neither adrenalectomy nor high doses of hydrocortisone could revert bone alterations in talc-injected animals. Glucocorticoids were necessary for the development of hypozincemia and hypercupremia seen in talc granulomatosis, as well as for normal bone metabolism. Inhibition of prostaglandin synthesis had no effect on bone alterations and serum APR in rats bearing talc-induced granulomas. We conclude that the decrease in bone formation constitutes an important aspect of the host acute-phase response in a rat model of talc granulomatosis.

Holographic analysis of the human pelvis.

Twelve fresh human pelves with preserved lumbar spines, hip joints, and ligaments, were tested by double-exposure and sandwich-hologram interferometry. During physiologic loadings (50-300 N), the pelvis moved as a whole downward and backward. Iliac wings exhibited marked undulation, except for the central part, which showed minor deformations. The sacrum moved downward and rotated forward over an axis 5-9 cm below the promontorium. Removal of the sacroiliac interosseous ligaments eliminated all joint movements and caused a tighter contact between articular surfaces. Removal of the sacrotuberous and sacrospinous ligaments had no influence on the pelvic behavior. The magnitudes of deformations as well as their underlying mineral contents were unequally distributed between the two pelvic sides. These results indicate that the sacroiliac interosseous ligaments are the main determinant of sacral movement. Asymmetric load transmittance to the hip joints might be responsible for the mineral content differences between the pelvic sides.

Ganglioside expression in tissues of mice lacking the tumor necrosis factor receptor 1.

This study presents a comparative analysis of gangliosides from lymphoid (spleen and thymus) and other tissues (brain, liver, lung, muscle) of C57BL/6 mice homozygous (-/-) and heterozygous (+/-) for the tumor necrosis factor receptor 1 (TNFRp55). Quantitative and qualitative differences in the expression of the lipid-bound N-acetylneuraminic (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc) and of various ganglioside biosynthesis pathways were detected between the tissues of the TNFRp55 -/- and the control TNFRp55 +/- mice. Sialic acid profiles showed a strong decrease in the absolute amount of sialic acids (Neu5Ac + Neu5Gc) in the lungs and thymus of homozygous (1.41 and 0.3 ng/mg wet weight, respectively) compared with control heterozygous animals (7.18 and 2.05 ng/mg wet weight, respectively). Considerable differences of Neu5Ac/Neu5Gc ratios in the lungs, muscle, spleen, and thymus were also detected. The gangliosides GM3(Neu5Ac) and GM3(Neu5Gc) were the dominant gangliosides in the lungs of the control animals, whereas the knockout mice almost completely lacked these structures in this organ. Reduced expression of GM1b-type gangliosides (GM1b and GalNAc-GM1b) was also found in the lungs, spleen, and thymus of the TNFRp55 knockout mice. On the other hand, neolacto-series gangliosides were more abundant in the lungs, brain, and muscle of the knockout mice, whereas their expression in the liver, spleen, and thymus was similar in both groups of animals. This study provides in vivo evidence that TNF signaling via the TNFRp55 is involved in the acquisition of a distinct ganglioside assembly in different mouse organs. TNFRp55 signaling seems to be especially important for the activation of the GM1b-type ganglioside biosynthetic pathway that is a unique characteristic of the mouse lymphoid tissues.

New bone formation in autologous membranous bone transplanted into the anterior abdominal wall.

During a gross anatomy dissection, a piece of the calvarial bone was found between aponeuroses of the anterior abdominal wall in an 82-year-old male cadaver. It corresponded closely in size to the calvarial defect after the neurosurgery performed 5 years before death, showing that very little resorption had occurred over the years. Moreover, 13 percent of the transplant was new bone, indicating that membranous bone can, in the long term, induce new bone formation in humans.