Maternal dietary intake of nitrates, nitrites and nitrosamines and selected birth defects in offspring: a case-control study

BACKGROUND: Dietary intake of nitrates, nitrites, and nitrosamines can increase the endogenous formation of N-nitroso compounds in the stomach. Results from animal studies suggest that these compounds might be teratogenic. We examined the relationship between maternal dietary intake of nitrates, nitrites (including plant and animal sources as separate groups), and nitrosamines and several types of birth defects in offspring. METHODS: For this population-based case–control study, data from a 58-question food frequency questionnaire, adapted from the short Willett Food Frequency Questionnaire and administered as part of the National Birth Defects Prevention Study (NBDPS), were used to estimate daily intake of dietary nitrates, nitrites, and nitrosamines in a sample of 6544 mothers of infants with neural tube defects (NTD)s, oral clefts (OC)s, or limb deficiencies (LD)s and 6807 mothers of unaffected control infants. Total daily intake of these compounds was divided into quartiles based on the control mother distributions. Odds ratios (OR)s and 95% confidence intervals (CI)s were estimated using logistic regression; estimates were adjusted for maternal daily caloric intake, maternal race-ethnicity, education, dietary folate intake, high fat diet (> 30% of calories from fat), and state of residence. RESULTS: While some unadjusted ORs for NTDS had 95% (CI)s that excluded the null value, none remained significant after adjustment for covariates, and the effect sizes were small (adjusted odds ratios [aOR] <1.12). Similar results were found for OCs and LDs with the exception of animal nitrites and cleft lip with/without cleft palate (aORs and CIs for quartile 4 compared to quartile 1 =1.24; CI=1.05-1.48), animal nitrites and cleft lip (4th quartile aOR=1.32; CI=1.01-1.72), and total nitrite and intercalary LD (4th quartile aOR=4.70; CI=1.23-17.93). CONCLUSIONS: Overall, odds of NTDs, OCs or LDs did not appear to be significantly associated with estimated dietary intake of nitrate, nitrite, and nitrosamines

Effective priming of herpes simplex virusspecific CD8+ T cells in vivo does not require infected dendritic cells

Resolution of virus infections depends on the priming of virus-specific CD8+ T cells by dendritic cells (DC). While this process requires major histocompatibility complex (MHC) class I-restricted antigen presentation by DC, the relative contribution to CD8+ T cell priming by infected DC is less clear. We have addressed this question in the context of a peripheral infection with herpes simplex virus 1 (HSV). Assessing the endogenous, polyclonal HSV-specific CD8+ T cell response, we found that effective in vivo T cell priming depended on the presence of DC subsets specialized in cross-presentation, while Langerhans cells and plasmacytoid DC were dispensable. Utilizing a novel mouse model that allows for the in vivo elimination of infected DC, we also demonstrated in vivo that this requirement for cross-presenting DC was not related to their infection but instead reflected their capacity to cross-present HSV-derived antigen. Taking the results together, this study shows that infected DC are not required for effective CD8+ T cell priming during a peripheral virus infection. IMPORTANCE The ability of some DC to present viral antigen to CD8+ T cells without being infected is thought to enable the host to induce killer T cells even when viruses evade or kill infected DC. However, direct experimental in vivo proof for this notion has remained elusive. The work described in this study characterizes the role that different DC play in the induction of virus-specific killer T cell responses and, critically, introduces a novel mouse model that allows for the selective elimination of infected DC in vivo. Our finding that HSV-specific CD8+ T cells can be fully primed in the absence of DC infection shows that cross-presentation by DC is indeed sufficient for effective CD8+ T cell priming during a peripheral virus infection.Our research is supported by the National Health and Medical Research Council of Australia. P. Whitney is supported by an Overseas Biomedical Fellowship (NHMRC) and a MDHS Faculty Fellowship (University of Melbourne). T. Gebhardt is supported by a fellowship from the Sylvia and Charles Viertel Charitable Foundation. D. Tscharke is supported by a Senior Research Fellowship (NHMRC)

Ameloblastic Fibro-odontoma Case Report: Diagnostic Valuable Aid of CT Scan in Identification of Mineralized Component

Many lesions that occur in the jaw have a similar radiographical appearance and it is often difficult to differentiate among them. Despite development of various cross-sectional imaging modalities the radiograph still remains the first and the most important investigation. Radiographical evaluation of jaw lesion characteristics, which include location, margin, density, relation to tooth, along with knowledge of the clinical data, generally helps in narrowing the diagnosis. With advancing technology today the mutti-row scanners are used for an increasing number of indications for routine examinations. Most major research facilities use 64-slice scanners on a routine clinical basis. Computed tomography (CT) scans are not ideal for imaging soft tissues such as muscles, joints or brain, but are perfect for detecting air or calcium. CT provides very good spatial resolution, that is the ability to distinguish between two separate structures that are very close together. But precision in identifying these calcified structures could be upregulated by the use of this normal routine specialized technique along with a software, which uses in its principle methods to quantity and qualitate the density

The Spin of a Newborn Black Hole: Swift J1728.9-3613

Abstract The origin and distribution of stellar-mass black hole spins are a rare window into the progenitor stars and supernova events that create them. Swift J1728.9-3613 is an X-ray binary, likely associated with the supernova remnant (SNR) G351.9-0.9. An NuSTAR X-ray spectrum of this source during its 2019 outburst reveals reflection from an accretion disk extending to the innermost stable circular orbit. Modeling of the relativistic Doppler shifts and gravitational redshifts imprinted on the spectrum measures a dimensionless spin parameter of a = 0.86 ± 0.02 (1σ confidence), a small inclination angle of the inner accretion disk θ &lt; 10°, and a subsolar iron abundance in the disk A Fe &lt; 0.84. This high spin value rules out a neutron star primary at the 5σ level of confidence. If the black hole is located in a still visible SNR, it must be young. Therefore, we place a lower limit on the natal black hole spin of a &gt; 0.82, concluding that the black hole must have formed with a high spin. This demonstrates that black hole formation channels that leave an SNR, and those that do not (e.g., Cyg X-1), can both lead to high natal spin with no requirement for subsequent accretion within the binary system. Emerging disparities between the population of high-spin black holes in X-ray binaries and the low-spin black holes that merge in gravitational wave events may therefore be explained in terms of different stellar conditions prior to collapse, rather than different environmental factors after formation.</jats:p

The Spin of a Newborn Black Hole: Swift J1728.9-3613

The origin and distribution of stellar-mass black hole spins are a rare window into the progenitor stars and supernova events that create them. Swift J1728.9-3613 is an X-ray binary, likely associated with the supernova remnant (SNR) G351.9-0.9. An NuSTAR X-ray spectrum of this source during its 2019 outburst reveals reflection from an accretion disk extending to the innermost stable circular orbit. Modeling of the relativistic Doppler shifts and gravitational redshifts imprinted on the spectrum measures a dimensionless spin parameter of a = 0.86 ± 0.02 (1 σ confidence), a small inclination angle of the inner accretion disk θ 0.82, concluding that the black hole must have formed with a high spin. This demonstrates that black hole formation channels that leave an SNR, and those that do not (e.g., Cyg X-1), can both lead to high natal spin with no requirement for subsequent accretion within the binary system. Emerging disparities between the population of high-spin black holes in X-ray binaries and the low-spin black holes that merge in gravitational wave events may therefore be explained in terms of different stellar conditions prior to collapse, rather than different environmental factors after formation

The Black Hole Candidate Swift J1728.9–3613 and the Supernova Remnant G351.9–0.9

A number of neutron stars have been observed within the remnants of the core-collapse supernova explosions that created them. In contrast, black holes are not yet clearly associated with supernova remnants (SNRs). Indeed, some observations suggest that black holes are “born in the dark,” i.e., without a supernova explosion. Herein, we present a multiwavelength analysis of the X-ray transient Swift J1728.9−3613, based on observations made with Chandra, ESO-VISTA, MeerKAT, NICER, NuSTAR, Swift, and XMM-Newton. Three independent diagnostics indicate that the system likely harbors a black hole primary. Infrared imaging signals a massive companion star that is broadly consistent with an A or B spectral type. Most importantly, the X-ray binary lies within the central region of the cataloged SNR G351.9−0.9. Our deep MeerKAT image at 1.28 GHz signals that the remnant is in the Sedov phase; this fact and the nondetection of the soft X-ray emission expected from such a remnant argue that it lies at a distance that could coincide with the black hole. Utilizing a formal measurement of the distance to Swift J1728.9−3613 ( d = 8.4 ± 0.8 kpc), a lower limit on the distance to G351.9−0.9 ( d ≥ 7.5 kpc), and the number and distribution of black holes and SNRs within the Milky Way, extensive simulations suggest that the probability of a chance superposition is <1.7% (99.7% credible interval). The discovery of a black hole within an SNR would support numerical simulations that produce black holes and remnants, and thus provide clear observational evidence of distinct black hole formation channels. We discuss the robustness of our analysis and some challenges to this interpretation

The Black Hole Candidate Swift J1728.9–3613 and the Supernova Remnant G351.9–0.9

A number of neutron stars have been observed within the remnants of the core-collapse supernova explosions that created them. In contrast, black holes are not yet clearly associated with supernova remnants (SNRs). Indeed, some observations suggest that black holes are “born in the dark,” i.e., without a supernova explosion. Herein, we present a multiwavelength analysis of the X-ray transient Swift J1728.9−3613, based on observations made with Chandra, ESO-VISTA, MeerKAT, NICER, NuSTAR, Swift, and XMM-Newton. Three independent diagnostics indicate that the system likely harbors a black hole primary. Infrared imaging signals a massive companion star that is broadly consistent with an A or B spectral type. Most importantly, the X-ray binary lies within the central region of the cataloged SNR G351.9−0.9. Our deep MeerKAT image at 1.28 GHz signals that the remnant is in the Sedov phase; this fact and the nondetection of the soft X-ray emission expected from such a remnant argue that it lies at a distance that could coincide with the black hole. Utilizing a formal measurement of the distance to Swift J1728.9−3613 (d = 8.4 ± 0.8 kpc), a lower limit on the distance to G351.9−0.9 (d ≥ 7.5 kpc), and the number and distribution of black holes and SNRs within the Milky Way, extensive simulations suggest that the probability of a chance superposition is <1.7% (99.7% credible interval). The discovery of a black hole within an SNR would support numerical simulations that produce black holes and remnants, and thus provide clear observational evidence of distinct black hole formation channels. We discuss the robustness of our analysis and some challenges to this interpretation