Disease relevance of helium

• Hyperpolarized helium-3 (HHe3) provides a new technique for magnetic resonance imaging of lung diseases [1].
• Emphysema: hyperpolarized helium 3 diffusion MR imaging of the lungs compared with spirometric indexes--initial experience [2].
• Four patients with cystic fibrosis (CF) were examined with combined hyperpolarized helium 3-enhanced and conventional proton magnetic resonance (MR) imaging [3].
• Pulmonary ventilation and perfusion scanning using hyperpolarized helium-3 MRI and arterial spin tagging in healthy normal subjects and in pulmonary embolism and orthotopic lung transplant patients [4].
• 2 Helium pressure of 130 atm did not alter the amplitude of the responses recorded from the ganglion in response to gamma-aminobutyric acid (GABA) application (9.7 and 19.4 microM) but the amplitude of responses to a nicotinic agonist were depressed [5].

High impact information on helium

• The correlation between increased concentrations of helium-3, a tracer of fine-grained interplanetary dust, and large impacts indicates that the abundance of Earth-crossing objects and dustiness in the inner solar system were simultaneously but only briefly enhanced [6].
• The agreement between the predicted and observed abundances of deuterium, helium-3, helium-4, and lithium-7 confirms the standard cosmology model and allows accurate determination of the baryon density, between 1.7 x 10(-31) and 4.1 x 10(-31) grams per cubic centimeter (corresponding to about 1 to 15 percent of the critical density) [7].
• Imaging the lungs in asthmatic patients by using hyperpolarized helium-3 magnetic resonance: assessment of response to methacholine and exercise challenge [1].
• Dynamic hyperpolarized helium 3 (3He) magnetic resonance (MR) imaging of the human airways is achieved by using a fast gradient-echo pulse sequence during inhalation [8].
• Exponentially growing cultures of early passaged fibroblasts were grown as monolayers on thin mylar sheets and were irradiated with accelerated protons, deuterons or helium-3 ions [9].

Chemical compound and disease context of helium

• Contrary to previous studies, only three patients with chronic airflow obstruction failed consistently to increase flow rates by greater than or equal to 20% when breathing He/O2 at all lung volumes measured [10].
• METHODS: Twenty-four pigs were randomized into the following four groups, based on the method for obtaining surgical exposure while a colectomy or laparoscopic-assisted colectomy was performed: Open surgery (n = 6), CO2 pneumoperitoneum (n = 6), Helium pneumoperitoneum (n = 6), and abdominal wall Lifter (n = 6) [11].
• Subgingival plaque samples from patients with chronic periodontitis were exposed to light from a 7.3 mW Helium/Neon laser for 30 s in the presence and absence of 50 micrograms/ml toluidine blue O as a photosensitizer [12].

Biological context of helium

• Thirty-two magnetic resonance imaging examinations of the lungs were performed in 16 subjects after inhalation of 1-2 L of helium 3 gas that was laser polarized to 10%-25% [13].
• We compared flow rates at 50% of the vital capacity (V50) breathing He/O2 to those breathing air at rest, and with the lowest V50 on air after exercise [14].
• Relative biological effectiveness (RBE) for mutagenesis, based on the initial slopes of the dose-response curves, ranged from 1.30 for 10 keV/micron protons to 9.40 for 150 keV/micron helium-3 ions [9].
• A new strategy for a quantitative measurement of regional pulmonary ventilation using hyperpolarized helium-3 (3He) MRI has been developed [15].
• Quantitative measurements of regional lung ventilation using helium-3 MRI in a methacholine-induced bronchoconstriction model [16].

Anatomical context of helium

• Precision, high dose radiotherapy. II. Helium ion treatment of tumors adjacent to critical central nervous system structures [17].
• To gain some insight into the mechanism of cell photostimulation by laser light, measurements were made of the rate of ADP/ATP exchange in mitochondria irradiated with the low power continuous wave Helium Neon laser (energy dose 5 Joules/cm2) [18].
• Initial Yields of DNA Double-Strand Breaks and DNA Fragmentation Patterns Depend on Linear Energy Transfer in Tobacco BY-2 Protoplasts Irradiated with Helium, Carbon and Neon Ions [19].
• Published survival data for V79 cells irradiated by monoenergetic protons, helium-3, carbon and oxygen ions and for CHO cells irradiated by carbon ions have been analysed using the probabilistic two-stage model of cell inactivation [20].
• CONCLUSION: Helium-neon (632 nm) low-power laser can enhance SP production in arthritic chondrocytes [21].

Associations of helium with other chemical compounds

• METHODS: Helium kinetics across skeletal muscle were determined during and after 20 min of helium inhalation, at separate resting and low steady-states of femoral vein blood flow in six sheep under isoflurane anaesthesia [22].
• Eight patients with CF then were treated with nebulized albuterol, after which a follow-up HHe MR scan was obtained [23].
• BACKGROUND: Helium-oxygen (heliox) mixtures are being used more frequently with mechanical ventilators [24].

Gene context of helium

• CONCLUSIONS: Helium-oxygen mixture decreases WOB in mechanically ventilated COPD patients [25].

Analytical, diagnostic and therapeutic context of helium

• SUBJECTS: Helium was administered as an 80:20 mixture of helium-oxygen through the air inlet of the ventilator [26].
• Evaluation of Asthma With Hyperpolarized Helium-3 MRI: Correlation With Clinical Severity and Spirometry [27].
• CONCLUSIONS: Helium gas should be considered the agent of choice for intraperitoneal insufflation in high-risk patients not only because helium avoids the metabolic consequences of CO(2) insufflation but also because it permits selected procedures to be performed under local-regional anesthesia [28].
• Diffusion-weighted MRI of the lung with hyperpolarized helium-3: a study of reproducibility [29].
• NMR imaging of thermally polarized helium-3 gas [30].

References