The use of (99m}Tc-Al[2]O[3] for detection of sentinel lymph nodes in breast cancer

Purpose: to study the feasibility of using the new radiopharmaceutical based on the technetium-99m-labeled gamma-alumina for identification of sentinel lymph nodes (SLNs) in breast cancer patients. The study included two groups of breast cancer patients who underwent single photon emission computed tomography (SPECT) and intraoperaive gamma probe identification of sentinel lymph nodes (SLNs). To identify SLNs, the day before surgery Group I patients (n=34) were injected with radioactive {99m}Tc-Al[2]O[3], and Group II patients (n=30) received 99mTc-labeled phytate colloid. A total of 37 SLNs were detected in Group I patients. The number of identified SLNs per patient ranged from 1 to 2 (the average number of identified SLNs was 1.08). Axillary lymph nodes were the most common site of SLN localization. 18 hours after {99m}Tc-Al[2]O[3] injection, the percentage of its accumulation in the SLN was 7-11% (of the counts in the injection site) by SPECT and 17-31% by gamma probe detection. In Group II SLNs were detected in 27 patients. 18 hours after injection of the phytate colloid the percentage of its accumulation in the SLN was 1.5-2% out of the counts in the injection site by SPECT and 4-7% by gamma probe. The new radiopharmaceutical based on the {99m}Tc-Al[2]O[3] demonstrates high accumulation in SLNs without redistribution through the entire lymphatic basin. The sensitivity and specificity of {99m}Tc-Al[2]O[3] were 100% for both SPECT and intraoperative gamma probe identification

The use of (99m}Tc-Al[2]O[3] for detection of sentinel lymph nodes in breast cancer

Purpose: to study the feasibility of using the new radiopharmaceutical based on the technetium-99m-labeled gamma-alumina for identification of sentinel lymph nodes (SLNs) in breast cancer patients. The study included two groups of breast cancer patients who underwent single photon emission computed tomography (SPECT) and intraoperaive gamma probe identification of sentinel lymph nodes (SLNs). To identify SLNs, the day before surgery Group I patients (n=34) were injected with radioactive {99m}Tc-Al[2]O[3], and Group II patients (n=30) received 99mTc-labeled phytate colloid. A total of 37 SLNs were detected in Group I patients. The number of identified SLNs per patient ranged from 1 to 2 (the average number of identified SLNs was 1.08). Axillary lymph nodes were the most common site of SLN localization. 18 hours after {99m}Tc-Al[2]O[3] injection, the percentage of its accumulation in the SLN was 7-11% (of the counts in the injection site) by SPECT and 17-31% by gamma probe detection. In Group II SLNs were detected in 27 patients. 18 hours after injection of the phytate colloid the percentage of its accumulation in the SLN was 1.5-2% out of the counts in the injection site by SPECT and 4-7% by gamma probe. The new radiopharmaceutical based on the {99m}Tc-Al[2]O[3] demonstrates high accumulation in SLNs without redistribution through the entire lymphatic basin. The sensitivity and specificity of {99m}Tc-Al[2]O[3] were 100% for both SPECT and intraoperative gamma probe identification

The first experience of using of {99}mTc-Al[2]O[3] for detection of sentinel lymph nodes in breast cancer

Purpose: to study the feasibility of using the new radiopharmaceutical based on the technetium-99m-labeled gamma-alumina for identification of sentinel lymph nodes (SLNs) in breast cancer patients. Materials and methods. The study included two groups of breast cancer patients who underwent single photon emission computed tomography (SPECT) and intraoperaive gamma probe identification of sentinel lymph nodes (SLNs). To identify SLNs, the day before surgery Group I patients (n=34) were injected with radioactive {99m}Tc-Al[2]0[3], and Group II patients (n=30) received {99m}Tc-labeled phytate colloid. Results. A total of 37 SLNs were detected in Group I patients. The number of identified SLNs per patient ranged from 1 to 2 (the average number of identified SLNs was 1.08). Axillary lymph nodes were the most common site of SLN localization. At 18 hours after {99m}Tc-Al[2]0[3] injection, the percentage of its accumulation in the SLN was 7-11% (of the counts in the injection site) by SPECT and 17-31% by gamma probe detection. In Group II patients, SLNs were detected in 27 patients. At 18 hours after injection of the phytate colloid, the percentage of its accumulation in the SLN was 1.5-2% out of the counts in the injection site by SPECT and 4-7% by gamma probe. Conclusion. The new radiopharmaceutical based on the {99m}Tc -Al[2]0[3] demonstrates high accumulation in SLNs without redistribution through the entire lymphatic basin. Sensitivity and specificity of {99m}Tc -Al[2]0[3] were 100% for both SPECT and intraoperative gamma probe identification

Prognosis of fungal infection of central nervous system in HIV-infected patients: a retrospective study of 77 patients in Ukraine

Introduction: We aimed to describe the epidemiological, clinical, laboratory characteristics, and out-comes of central nervous system (CNS) mycosis in patients with human immunodeficiency virus (HIV) and to determine characteristics associated with a higher risk of death. Retrospective data from 77 case histories of HIV-infected patients with neurological symptoms caused by various fungi including Can-dida and Cryptococcus in Dnipro, Ukraine, were analysed as a case-control study with 40 deceased indi-viduals considered as cases and 37 patients with favourable outcome (survivors) considered as controls.Material and methods: Fungi in cerebrospinal fluid (CSF) were detected with traditional culture methods. Multivariate analysis used (1) binary logistic regression with survivor/dead as a dependent variable and (2) a classification and regression tree (CRT method). Results: A combination of fungal infection with other infections of CNS (dual and triple coinfec-tion) was diagnosed in most cases (n = 53, 68.8%), while the proportion of co-infection was some-what lower among survivors (59.5%). Clinical manifestations were non-specific. Risk of death was higher among those with tuberculosis (AOR = 2.7, 95% CI: 1.0-7.5) and lower among those infect-ed with Epstein-Barr virus (EBV) (AOR = 0.3, 95% CI: 0.1-1.0) and among patients on ART (AOR = 0.2, 95% CI: 0.1-0.8). Risk of death significantly decreased over time. The classification tree shows that among HIV-mycosis neurological patients not on ART with tuberculosis, the risk of death constituted 75%, while among patients on ART with EBV-infection, all patients survived.Conclusions: Opportunistic mycoses remain an important clinical challenge among immuno-compro-mised patients especially those who were diagnosed with HIV late, failed to get antiretroviral therapy, and developed tuberculosis

Evidence of unidirectional hybridization and second‐generation adult hybrid between the two largest animals on Earth, the fin and blue whales

Biodiversity in the oceans has dramatically declined since the beginning of the industrial era, with accelerated loss of marine biodiversity impairing the ocean's capacity to maintain vital ecosystem services. A few organisms epitomize the damaging and long‐lasting effects of anthropogenic exploitation: some whale species, for instance, were brought to the brink of extinction, with their population sizes reduced to such low levels that may have cause a significant disruption to their reproductive dynamics and facilitated hybridization events. The incidence of hybridization is nevertheless believed to be rare and very little information exist on its directionality. Here, using genetic markers, we show that all but one whale hybrid sample collected in Icelandic waters originated from the successful mating of male fin whale and female blue whale, thus suggesting unidirectional hybridization. We also demonstrate for the first time the existence of a second‐generation adult (male) hybrid resulting from a backcross between a female hybrid and a pure male fin whale. The incidence of hybridization events between fin and blue whales is likely underestimated and the observed unidirectional hybridization (for F1 and F2 hybrids) is likely to induce a reproductive loss in blue whale, which may represent an additional challenge to its recovery in the Atlantic Ocean compared to other rorquals

Detection of extended TeV emission around the Geminga pulsar with H.E.S.S.

Highly extended gamma-ray emission around the Geminga pulsar was discovered by Milagro and verified by HAWC. Despite many observations with Imaging Atmospheric Cherenkov Telescopes (IACTs), detection of gamma-ray emission on angular scales exceeding the IACT field-of-view has proven challenging. Recent developments in analysis techniques have enabled the detection of significant emission around Geminga in archival data with H.E.S.S.. In 2019, further data on the Geminga region were obtained with an adapted observation strategy. Following the announcement of the detection of significant TeV emission around Geminga in archival data, in this contribution we present the detection in an independent dataset. New analysis results will be presented, and emphasis given to the technical challenges involved in observations of highly extended gamma-ray emission with IACTs

Astronomy outreach in Namibia : H.E.S.S. and beyond

Astronomy plays a major role in the scientific landscape of Namibia. Because of its excellent sky conditions, Namibia is home to ground-based observatories like the High Energy Spectroscopic System (H.E.S.S.), in operation since 2002. Located near the Gamsberg mountain, H.E.S.S. performs groundbreaking science by detecting very-high-energy gamma rays from astronomical objects. The fascinating stories behind many of them are featured regularly in the "Source of the Month", a blog-like format intended for the general public with more than 170 features to date. In addition to other online communication via social media, H.E.S.S. outreach activities have been covered locally, e.g. through 'open days' and guided tours on the site itself. An overview of the H.E.S.S. outreach activities are presented in this contribution, along with discussions relating to the current landscape of astronomy outreach and education in Namibia. There has also been significant activity in the country in recent months, whereby astronomy is being used to further sustainable development via human capacity-building. Finally, as we take into account the future prospects of radio astronomy in the country, momentum for a wider range of astrophysics research is clearly building — this presents a great opportunity for the astronomy community to come together to capitalise on this movement and support astronomy outreach, with the overarching aim to advance sustainable development in Namibia

Detection of new Extreme BL Lac objects with H.E.S.S. and Swift XRT

Extreme high synchrotron peaked blazars (EHBLs) are amongst the most powerful accelerators found in nature. Usually the synchrotron peak frequency of an EHBL is above 10$^{17}$ Hz, i.e., lies in the range of medium to hard X-rays making them ideal sources to study particle acceleration and radiative processes. EHBL objects are commonly observed at energies beyond several TeV, making them powerful probes of gamma-ray absorption in the intergalactic medium. During the last decade, several attempts have been made to increase the number of EHBL detected at TeV energies and probe their spectral characteristics. Here we report new detections of EHBLs in the TeV energy regime, each at a redshift of less than 0.2, by the High Energy Stereoscopic System (H.E.S.S.). Also, we report on X-ray observations of these EHBLs candidates with Swift-XRT. In conjunction with the very high energy observations, this allows us to probe the radiation mechanisms and the underlying particle acceleration processes

Search for enhanced TeV gamma ray emission from Giant Molecular Clouds using H.E.S.S.

Cosmic Ray (CR) interactions with the dense gas inside Giant Molecular Clouds (GMCs) produce neutral pions, which in turn decay into gamma rays. Thus, the gamma ray emission from GMCs is a direct tracer of the cosmic ray density and the matter density inside the clouds. Detection of enhanced TeV emission from GMCs, i.e., an emission significantly larger than what is expected from the average Galactic cosmic rays illuminating the cloud, can imply a variation in the local cosmic ray density, due to, for example, the presence of a recent accelerator in proximity to the cloud. Such gamma-ray observations can be crucial in probing the cosmic ray distribution across our Galaxy, but are complicated to perform with present generation Imaging Atmospheric Cherenkov Telescopes (IACTs). These studies require differentiating between the strong cosmic-ray induced background, the large scale diffuse emission, and the emission from the clouds, which is difficult to the small field of view of present generation IACTs. In this contribution, we use H.E.S.S. data collected over 16 years to search for TeV emission from GMCs in the inner molecular galacto-centric ring of our Galaxy. We implement a 3D FoV likelihood technique, and simultaneously model the hadronic background, the galactic diffuse emission and the emission expected from known VHE sources to probe for excess TeV gamma ray emission from GMCs

Is PKS 0625-354 another variable TeV active galactic nucleus?

The majority of the active galactic nuclei (AGN) detected at very-high-energies above 100 GeV belong to the class of blazars with a small angle between the jet-axis and the line-of-sight. Only about 10 percent of the gamma-ray AGN are objects with a larger viewing angle resulting in a smaller Doppler boosting of the emission. Originally, it was believed that gamma-ray emission can only be observed from blazars and those are variable in its brightness. Instead, the last years have shown that non-blazar active galaxies also show a fascinating variability behaviour which provide important new insights into the physical processes responsible for the gamma-ray production and especially for flaring events. Here, we report on the observation of gamma-ray variability of the active galaxy PKS 0625−354 detected with the H.E.S.S. telescopes in November 2018. The classification of PKS 0625−354 is a still matter of debate. The H.E.S.S. measurements were performed as part of a flux observing program and showed in the first night of the observation a detection of the object with > 5σ. A denser observation campaign followed for the next nine nights resulting in a decrease of the gamma-ray flux. Those observations were accompanied with Swift in the X-ray and UV/optical band allowing for the reconstruction of a multi-band broad-band spectral energy distribution. We will discuss the implications of the gamma-ray variability of the object