Environmental effect of air versus gas tamponade in the management of rhegmatogenous retinal detachment VR surgery: A multicentre study of 3,239 patients.

PURPOSE: To report the potential reduction of carbon emissions by utilising air-tamponade (AT), where possible, instead of fluorinated gases in the management of rhegmatogenous retinal detachment (RRD). We compared the carbon CO2 emissions produced at two large tertiary referral vitreoretinal (VR) centres where RRD are exclusively repaired using fluorinated gases to a tertiary VR mass of each gas used according to the Intergovernmental Panel on Climate Change. MATERIALS AND METHODS: Retrospective, continuous, comparative multicentre study of all procedures using fluorinated gases between 01/01/17-31/12/20 at the Manchester Royal Eye Hospital (MREH) and Birmingham and Midland Eye Centre (BMEC), and between 01/01/19-31/12/2020 at the University Hospitals Coventry and Warwickshire (UHCW). RESULTS: We report on 3,239 (SF6:1,415 [43.7%], C2F6:1,235 [38.1%], C3F8:541 [16.7%], Air:48 [1.5%]) procedures. UHCW and BMEC utilise single use 30ml and 75ml cannisters, respectively and MREH use multi-use gas cylinders. UHCW used AT in 48 (70%) of RRD repairs. Mean equivalent mass CO2/patient was MREH:115.9kg, BMEC:7.9kg and UHCW:1.9kg. If assuming all centres used 30ml cannisters, the mean equivalent mass CO2/patient was MREH:3.5 kg, BMEC:3.1kg and UHCW:1.9kg. AT enabled UHCW to greatly reduce the need for the most environmentally damaging SF6 gas, leading to lower CO2 emissions by 47.0% and 41.1% compared to MREH and BMEC, respectively. CONCLUSION: We demonstrate how AT vs. the fluorinated gases can reduce in carbon footprint in the management of RRD. Further studies are required to determine the most 'environment-friendly' intraocular tamponade without compromising patient outcomes centre that also routinely employs AT in selected RRD cases.

Multifunctional nanoplatforms co-delivering combinatorial dual-drug for eliminating cancer multidrug resistance.

Clinically, the primary cause of chemotherapy failure belongs to the occurrence of cancer multidrug resistance (MDR), which directly leads to the recurrence and metastasis of cancer along with high mortality. More and more attention has been paid to multifunctional nanoplatform-based dual-therapeutic combination to eliminate resistant cancers. In addition to helping both cargoes improve hydrophobicity and pharmacokinetic properties, increase bioavailability, release on demand and enhance therapeutic efficacy with low toxic effects, these smart co-delivery nanocarriers can even overcome drug resistance. Here, this review will not only present different types of co-delivery nanocarriers, but also summarize targeted and stimuli-responsive combination nanomedicines. Furthermore, we will focus on the recent progress in the co-delivery of dual-drug using such intelligent nanocarriers for surmounting cancer MDR. Whereas it remains to be seriously considered that there are some knotty issues in the fight against MDR of cancers via using co-delivery nanoplatforms, including limited intratumoral retention, the possible changes of combinatorial ratio under complex biological environments, drug release sequence from the nanocarriers, and subsequent free-drug resistance after detachment from the nanocarriers. It is hoped that, with the advantage of continuously developing nanomaterials, two personalized therapeutic agents in combination can be better exploited to achieve the goal of cooperatively combating cancer MDR, thus advancing the time to clinical transformation.

Pre-inhalation of hydrogen-rich gases protect against caerulein-induced mouse acute pancreatitis while enhance the pancreatic Hsp60 protein expression.

BACKGROUND: Acute pancreatitis (AP) lacks targeted prevention and treatment measures. Some key points in the pathogenesis of AP remain unclear, such as early activation of pancreatic enzymes. Several recent reports have shown the protective effect of hydrogen on several AP animal models, and the mechanism is related to antioxidant activity. Heat shock protein 60 (Hsp60) is known to accompany pancreatic enzymes synthesis and secretion pathway of in pancreatic acinar cells, while role of hsp60 in AP remains a topic. Aim of this study was to investigate effect of hydrogen pretreatment on AP and the mechanisms, focusing on pancreatic oxidative stress and Hsp60 expression. METHODS: 80 mice were randomly assigned into four groups: HAP group, AP group, HNS group, and NS group and each group were set 3 observation time point as 1 h, 3 h and 5 h (n = 6-8). Mouse AP model was induced by intraperitoneal injection of 50 µg/kg caerulein per hour for 6 injections both in AP and HAP groups, and mice in NS group and HNS group given normal saline (NS) injections at the same way as control respectively. Mice in HAP group and HNS group were treated with hydrogen-rich gases inhalation for 3 days before the first injection of caerulein or saline, while mice in AP group and NS group in normal air condition. Histopathology of pancreatic tissue, plasma amylase and lipase, plasma IL-1 and IL-6, pancreatic glutathione (GSH) and malondialdehyde (MDA), and Hsp60 mRNA and protein expression were investigated. Comparisons were made by one-way analysis of variance. RESULTS: The pancreatic pathological changes, plasma amylase and lipase activity, and the increase of plasma IL-1 and IL-6 levels in AP mice were significantly improved by the hydrogen-rich gases pretreatment, Meanwhile, the pancreatic GSH content increased and the pancreatic MDA content decreased. And, the hydrogen-rich gases pretreatment improved the Hsp60 protein expression in pancreatic tissues of AP mice at 1 h and 5 h. CONCLUSIONS: Pre-inhalation of hydrogen-rich gases have a good protective effect on AP mice, and the possible mechanisms of reduced oxidative stress and the early increased pancreatic Hsp60 protein deserve attention.

Responses to gastric gas in patients with functional gastrointestinal disorders.

BACKGROUND: Gas-related abdominal symptoms are common in patients with functional gut disorders, but the responses to cope with the large volumes of gas that enter daily into the stomach have not been studied in detail. Our aim was to evaluate transit and tolerance of gastric gas in patients with functional gastrointestinal disorders. METHODS: In eight healthy volunteers and 24 patients with functional gut disorders (eight functional dyspepsia, eight belching disorder, and eight functional bloating) 1500 ml of a gas mixture were infused into the stomach at 25 ml/min. Belching, rectal gas evacuation, and abdominal perception were continuously recorded for 90 minutes. KEY RESULTS: Healthy subjects expelled the infused gas per rectum (1614 ± 73 ml), with a small rise in epigastric perception (score increment 1.0 ± 0.4) and virtually no belching (1 ± 1 belches). Patients with functional dyspepsia had a hypersensitive response to gastric gas, with a significant rise in epigastric perception (score increment 2.5 ± 0.6; P = .045), a transient delay in rectal gas evacuation and similar belching as healthy controls. Patients with belching disorders responded to gastric gas with continuous belches (33 ± 13 belches; P = .002), low epigastric perception, and a small reduction in rectal gas evacuation. Patients with functional bloating exhibited a slow transit response, with reduced rectal gas evacuation (1017 ± 145 ml; P = .002) and abdominal symptoms (score increment 2.5 ± 0.7), but without compensatory belching. CONCLUSIONS AND INFERENCES: Different pathophysiological mechanisms underlay specific adaptive responses to gastric gas in patients with different functional gut disorders. Therapeutic interventions for gas-related abdominal symptoms should be addressed towards these specific pathophysiological disturbances.

Evaluation of Low-Temperature Sterilization using Hydrogen Peroxide Gas Containing Peracetic Acid.

In low-temperature sterilization for the medical field, hydrogen peroxide sterilization is widely used for its safety. However, its low penetrability and residual amount of sterilant are major concerns. Recently, the combination of hydrogen peroxide and peracetic acid has been found to enforce sporicidal effect, with low concentration in hydrogen peroxide. The application of this finding in medical sterilization is still very limited. To elucidate the combination effect, we compare peracetic acid containing hydrogen peroxide gas sterilizer and conventional hydrogen peroxide gas (plasma) sterilizers. The sterilant penetrability was examined in hollow load process challenge devices with inner diameters of 1 and 2 mm and lengths of 1, 2, and 3 m. As a result, peracetic acid containing hydrogen peroxide gas sterilizer demonstrated total inactivation with all diameters and lengths and achieved the highest sterilant penetrability in this study. The amount of residual sterilant on the surface of the sterilized object was 4.2 µg/cm2, which corresponds to half amount of those of conventional hydrogen peroxide gas sterilizers. These results suggest that the addition of peracetic acid to hydrogen peroxide gas sterilizer can enhance sterilization efficiency and safety.

Constitutive hydrogen inhalation prevents vascular remodeling via reduction of oxidative stress.

Molecular hydrogen is thought to have an inhibitory effect on oxidative stress, thereby attenuating the onset and progression of various diseases including cardiovascular disease; however, few reports have assessed the preventive effect of constitutive inhalation of hydrogen gas on of vascular remodeling. Here, we investigated the effect of constitutive inhalation of hydrogen gas on vascular neointima formation using a cuff-induced vascular injury mouse model. After constitutive inhalation of compressed hydrogen gas (O2 21%, N2 77.7%, hydrogen 1.3%) or compressed air only (O2 21%, N2 79%) by C57BL/6 mice for 2 weeks from 8 weeks of age in a closed chamber, inflammatory cuff injury was induced by polyethylene cuff placement around the femoral artery under anesthesia, and hydrogen gas administration was continued until sampling of the femoral artery. Neointima formation, accompanied by an increase in cell proliferation, was significantly attenuated in the hydrogen group compared with the control group. NADPH oxidase NOX1 downregulation in response to cuff injury was shown in the hydrogen group, but the expression levels of NADPH oxidase subunits, p40phox and p47phox, did not differ significantly between the hydrogen and control groups. Although the increase in superoxide anion production did not significantly differ between the hydrogen and control groups, DNA damage was decreased as a result of reduction of reactive oxygen species such as hydroxyl radical (⋅OH) and peroxynitrite (ONOO-) in the hydrogen group. These results demonstrate that constitutive inhalation of hydrogen gas attenuates vascular remodeling partly via reduction of oxidative stress, suggesting that constitutive inhalation of hydrogen gas at a safe concentration in the living environment could be an effective strategy for prevention of vascular diseases such as atherosclerosis.

[Treatment of submacular hematoma by vitrectomy, subretinal injection of rtPA and gaseous tamponade: A single-center retrospective observational study]. / Traitement des hématomes sous-maculaires par vitrectomie, injection sous-rétinienne de rtPA et tamponnement gazeux : une étude observationnelle rétrospective monocentrique.

OBJECTIVES: To evaluate the functional and anatomic recovery of submacular hemorrhage (SMH), treated with vitrectomy, subretinal injection of rtPA and gas tamponade, to highlight the risk factors for their occurrence as well as the factors influencing prognosis. MATERIALS AND METHODS: This is a single-center retrospective study. Thirty-two eyes of 30 patients from the Clermont-Ferrand University Hospital were included, with a submacular hemorrhage (SMH) requiring surgical evacuation. The primary endpoint was final postoperative visual recovery. Visual acuities (AV) were converted to the logarithmic minimum angle of resolution scale (logMAR) for statistical analysis. RESULTS: The average time from onset of symptoms to surgery was 4.8±3.3 days. The initial VA was 2.1±0.3 logMAR, with an average improvement of 0.7±0.7 logMAR (P=0.0004) at the final visit. The mean thickness of the SMH decreased by 729±352µm (P<0.0001) at the final visit. CONCLUSION: Treatment of SMH with vitrectomy, subretinal injection of rtPA and gas tamponade results in a statistically significant improvement in final VA, as well as a significant decrease in SMH thickness on OCT.

Tumor pH-responsive metastable-phase manganese sulfide nanotheranostics for traceable hydrogen sulfide gas therapy primed chemodynamic therapy.

Manganese-based nanomaterials have piqued great interest in cancer nanotheranostics, owing to their excellent physicochemical properties. Here we report a facile wet-chemical synthesis of size-controllable, biodegradable, and metastable γ-phase manganese sulfide nanotheranostics, which is employed for tumor pH-responsive traceable gas therapy primed chemodynamic therapy (CDT), using bovine serum albumin (BSA) as a biological template (The final product was denoted as MnS@BSA). The as-prepared MnS@BSA can be degraded in response to the mildly acidic tumor microenvironment, releasing hydrogen sulfide (H2S) for gas therapy and manganese ions for magnetic resonance imaging (MRI) and CDT. In vitro experiments validated the pH-responsiveness of MnS@BSA at pH 6.8 and both H2S gas and •OH radicals were detected during its degradation. In vivo experiments showed efficiently tumor turn-on T1-weighted MRI, significantly suppressed tumor growth and greatly prolonged survival of tumor-bearing mice following intravenous administration of MnS@BSA. Our findings indicated that MnS@BSA nanotheranostics hold great potential for traceable H2S gas therapy primed CDT of cancer.

Intratracheal Delivery of Nano- and Microparticles and Hyperpolarized Gases: A Promising Strategy for the Imaging and Treatment of Respiratory Disease.

Accurate diagnosis is crucial to improve the treatment and prognosis of respiratory disease, especially lung cancer. Tumors and lesions located deep in the lung are directly accessible via dendritic tracheal bronchus, thereby opening a new way to tackle respiratory disease. Intratracheal delivery is an innovative, noninvasive approach for imaging and treating respiratory disease efficiently, when compared with other delivery methods. Intratracheal delivery of nano- and microparticles and hyperpolarized gases offers valuable clinical advantages, such as assessing lung function, monitoring ventilation and perfusion, controlling disease progression, and inhibiting tumor growth. Especially, versatile nanosized particles have enormous potential to benefit precision imaging and therapy at the molecular level. Here we discuss advances of intratracheal delivery of nano- and microparticles and hyperpolarized gases for respiratory disease imaging and treatment, with an emphasis on intratracheal nanoparticles delivery for pulmonary imaging, which has extremely valuable clinical applications in precise theranostics for respiratory disease.

A Review of Sclerosing Foam Stability in the Treatment of Varicose Veins.

BACKGROUND: Varicose veins are common clinical entities. Foam sclerotherapy is a minimally invasive and simple procedure; however, the side effects, efficacy, and stability of sclerosing foam are not ideal. OBJECTIVE: To summarize the current studies on sclerosing foam stability and promote foam sclerotherapy development. MATERIALS AND METHODS: We reviewed the literature before June 2018 and included only representatives studies on sclerosing foam stability. We summarized the foam half-life time (FHT) of polidocanol (POL) under 17 preparation conditions and the FHT of sodium tetradecyl sulfate under 21 preparation conditions. The preparation conditions included various combinations of temperature, liquid-gas ratio, preparation method, etc. RESULTS: The FHT of POL varied between 40 and 4,000 seconds under different conditions. The FHT of sodium tetradecyl sulfate varied from 25.7 to 390 seconds. The higher the drug concentration, the lower the temperature required to increase foam stability. The addition of surfactant greatly increased foam stability. For different gas compositions, the FHT sequence was as follows: CO2 < CO2 + O2 < O2 < air. CONCLUSION: Foam stability can be improved by changing the preparation conditions; therefore, the role of surfactants and predictive methods for FHT are worth investigating further.

Respiratory gases, air pollution and epilepsy.

A growing number of studies have shown that exposure to air pollutants such as particulate matter and gases can cause cardiovascular, neurodegenerative and psychiatric diseases. The severity of the changes depends on several factors such as exposure time, age and gender. Inflammation has been considered as one of the main factors associated with the generation of these diseases. Here we present some cellular mechanisms activated by air pollution that may represent risk factors for epilepsy and drug resistance associated to epilepsy.

[Comparison of intraocular pressure reduction in eyes with different intraocular tamponades after pars plana vitrectomy by 20% mannitol].

Objective: To investigate the efficacy of 20% mannitol in reducing intraocular pressure (IOP) in eyes with different intraocular tamponades after pars plana vitrectomy (PPV). Methods: Retrospective case-control study. Sixty-eight patients were administered with 20% mannitol and IOP was noted at regular intervals after simple PPV with ocular hypertension, including 24 males (26 eyes) and 44 females (46 eyes), aged (45.6±19.3) years. These cases were divided into three groups according to different tamponades: silicon-oil tamponade, 23 eyes; gas tamponade, 30 eyes; balanced salt solution (BSS), 19 eyes. The data were analyzed using the t test, variance and q test. Results: There was a significant decrease in IOP in all patients after using 20% mannitol. The IOP in the group of silicon-oil decreased from (33.25±2.56) mmHg (1 mmHg=0.133 kPa) to (23.21±1.85) mmHg, with a maximum decrease of 30.10%; the reduction in the group of C(3)F(8) was from (33.25±2.84) mmHg to (12.15±1.12) mmHg, with a maximum decrease of 33.44%. The IOP of the two groups dropped to a minimum both at 75 minutes. In the group of BSS, the IOP decreased from (32.95±2.33) mmHg to (17.50±1.35) mmHg, and the maximum extent of the decrease was 45.82% at 45 minutes. The difference in the IOP among the three groups at 20 min, 30 min, 45 min and 60 min was statistically significant (F=34.02, 112.68, 122.07, 34.83, all P=0.00). There were significant differences between the BSS group and the silicone-oil group (q=6.44, 13.04, 15.00, 17.11, all P=0.00), and between the BSS group and the C(3)F(8) group (q=7.68, 12.56, 12.93, 13.61, all P=0.00). Conclusion: In eyes with different intraocular tamponades, 20% mannitol was useful for short-term IOP reduction after vitrectomy, especially in those with BSS within one hour. But after 75 minutes, there was no statistically significant difference between groups. (Chin J Ophthalmol, 2019, 55:289-293).

Inactivation of bacterial and fungal spores by UV irradiation and gaseous iodine treatment applied to air handling filters.

Exposure to viable bacterial and fungal spores re-aerosolized from air handling filters may create a major health risk. Assessing and controlling this exposure have been of interest to the bio-defense and indoor air quality communities. Methods are being developed for inactivating stress-resistant viable microorganisms collected on ventilation filters. Here we investigated the inactivation of spores of Bacillus thuringiensis var. kurstaki (Btk), a recognized simulant for B. antracis, and Aspergillus fumigatus, a common opportunistic pathogen used as an indicator for indoor air quality. The viability change was measured on filters treated with ultraviolet (UV) irradiation and gaseous iodine. The spores were collected on high-efficiency particulate air (HEPA) and non-HEPA filters, both flattened for testing purposes to represent "surface" filters. A mixed cellulose ester (MCE) membrane filter was also tested as a reference. Additionally, a commercial HEPA unit with a deep-bed (non-flattened) filter was tested. Combined treatments of Btk spores with UV and iodine on MCE filter produced a synergistic inactivation effect. No similar synergy was observed for A. fumigatus. For spores collected on an MCE filter, the inactivation effect was about an order of magnitude greater for Btk compared to A. fumigatus. The filter type was found to be an important factor affecting the inactivation of Btk spores while it was not as influential for A. fumigatus. Overall, the combined effect of UV irradiation and gaseous iodine on viable bacterial and fungal spores collected on flat filters was found to be potent. The benefit of either simultaneous or sequential treatment was much lower for Btk spores embedded inside the deep-bed (non-flattened) HEPA filter, but for A. fumigatus the inactivation on flattened and non-flattened HEPA filters was comparable. For both species, applying UV first and gaseous iodine second produced significantly higher inactivation than when applying them simultaneously or in an opposite sequence.

Nitrogen gas produces less behavioural and neurophysiological excitation than carbon dioxide in mice undergoing euthanasia.

Carbon dioxide (CO2) is one of the most commonly used gas euthanasia agents in mice, despite reports of aversion and nociception. Inert gases such as nitrogen (N2) may be a viable alternative to carbon dioxide. Here we compared behavioural and electrophysiological reactions to CO2 or N2 at either slow fill or rapid fill in C57Bl/6 mice undergoing gas euthanasia. We found that mice euthanised with CO2 increased locomotor activity compared to baseline, whereas mice exposed to N2 decreased locomotion. Furthermore, mice exposed to CO2 showed significantly more vertical jumps and freezing episodes than mice exposed to N2. We further found that CO2 exposure resulted in increased theta:delta of the EEG, a measure of excitation, whereas the N2 decreased theta:delta. Differences in responses were not oxygen-concentration dependent. Taken together, these results demonstrate that CO2 increases both behavioural and electrophysiological excitation as well as producing a fear response, whereas N2 reduces behavioural activity and central neurological depression and may be less aversive although still produces a fear response. Further studies are required to evaluate N2 as a suitable euthanasia agent for mice.

Comparative study of the efficacy of Platelet-rich plasma combined with carboxytherapy vs its use with fractional carbon dioxide laser in atrophic acne scars.

BACKGROUND: Acne scars are a major concerning problem to all acne patients affecting their quality of life. Platelet-rich plasma (PRP) and fractional CO2 laser are innovative treatment modalities for acne scars. Carboxytherapy can also be used to improve scar tissue through the increase in collagen deposition and reorganization, and the improvement in skin texture and tone. AIMS: The aim of this work was to compare the efficacy, safety, and complications of the intradermal injection of PRP combined with carboxytherapy and PRP combined with fractional CO2 laser, in the treatment of atrophic acne scars. PATIENTS AND METHODS: Forty patients with atrophic acne scars were divided into 2 groups. Group A included 20 patients and was subjected to three fractional CO2 laser sessions combined with PRP injection. Group B included 20 patients and was subjected to three sessions of carboxytherapy combined with PRP injection. RESULTS: Both fractional CO2 laser and carboxytherapy combined with PRP showed improvement in acne scars and patients' satisfaction but the improvement with fractional CO2 laser was significantly better than carboxytherapy but with more side effects. CONCLUSIONS: Improvement of acne scars was noted in both treatment modalities with obvious higher and statistically significant results in favor of fractional CO2 laser but with more side effects. Carboxytherapy is a promising tool in treatment of acne scars with less complication.

Treatment of periorbital dark circles: Comparative study of carboxy therapy vs chemical peeling vs mesotherapy.

OBJECTIVE: Evaluation and comparison of the efficacy and safety of 3 different modalities of treatment for dark circles that function via different modes of action. METHODS: In total, 45 female patients with periorbital hyperpigmentation were randomly selected to participate from those attending the outpatient dermatology clinic of Al-Zahraa University Hospital within a 6-month period. Patients were divided into 3 groups, and the groups were subjected to different types of therapy: group A, carboxy therapy; group B, chemical peel; and group C, vitamin C mesotherapy. RESULTS: No statistically significant differences were detected in improvements in pigmentation or the degree of patient satisfaction between any of the groups. However, the mesotherapy group reported more of a burning sensation following treatment than the other 2 groups but also showed a significant improvement in pigmentation and patient satisfaction compared with the carboxy group. CONCLUSION: All 3 treatment modalities were effective in the reduction in periorbital pigmentation. However, mesotherapy showed a significant improvement in pigmentation and a higher level of patient satisfaction compared with the other types of treatment.

Tunable Polymer Microcapsules for Controlled Release of Therapeutic Gases.

Encapsulation and delivery of oxygen, carbon dioxide, and other therapeutic gases, using polymeric microcapsules (PMCs) is an emerging strategy to deliver gas as an injectable therapeutic. The gas cargo is stored within the PMC core and its release is mediated by the physiochemical properties of the capsule shell. Although use of PMCs for the rapid delivery of gases has been well described, methods which tune the material properties of PMCs for sustained release of gas are lacking. In this work, we describe a simple method for the high-yield production of gas-in-oil-filled PMCs with tunable sizes and core gas content from preformed polymers using the sequential phase separation and self-emulsification of emulsion-based templates. We demonstrate that prolonged gas release occurs from gas-in-oil PMCs loaded with oxygen and carbon dioxide gas, each of which could have significant clinical applications.

Pulmonary Delivery of Therapeutic and Diagnostic Gases.

The 21st Congress for the International Society for Aerosols in Medicine included, for the first time, a session on Pulmonary Delivery of Therapeutic and Diagnostic Gases. The rationale for such a session within ISAM is that the pulmonary delivery of gaseous drugs in many cases targets the same therapeutic areas as aerosol drug delivery, and is in many scientific and technical aspects similar to aerosol drug delivery. This article serves as a report on the recent ISAM congress session providing a synopsis of each of the presentations. The topics covered are the conception, testing, and development of the use of nitric oxide to treat pulmonary hypertension; the use of realistic adult nasal replicas to evaluate the performance of pulsed oxygen delivery devices; an overview of several diagnostic gas modalities; and the use of inhaled oxygen as a proton magnetic resonance imaging (MRI) contrast agent for imaging temporal changes in the distribution of specific ventilation during recovery from bronchoconstriction. Themes common to these diverse applications of inhaled gases in medicine are discussed, along with future perspectives on development of therapeutic and diagnostic gases.

Hyperpolarized gas MRI in pulmonology.

Lung diseases have a high prevalence amongst the world population and their early diagnosis has been pointed out to be key for successful treatment. However, there is still a lack of non-invasive examination methods with sensitivity to early, local deterioration of lung function. Proton-based lung MRI is particularly challenging due to short T2* times and low proton density within the lung tissue. Hyperpolarized gas MRI is aan emerging technology providing a richness of methodologies which overcome the aforementioned problems. Unlike proton-based MRI, lung MRI of hyperpolarized gases may rely on imaging of spins in the lung's gas spaces or inside the lung tissue and thereby add substantial value and diagnostic potential to lung MRI. This review article gives an introduction to the MR physics of hyperpolarized media and presents the current state of hyperpolarized gas MRI of 3Headvasd and 129Xe in pulmonology. Key applications, ranging from static and dynamic ventilation imaging as well as oxygen-pressure mapping to 129Xe dissolved-phase imaging and spectroscopy are presented. Hyperpolarized gas MRI is compared to alternative examination methods based on MRI and future directions of hyperpolarized gas MRI are discussed.

A Randomized Trial of Conditioned or Unconditioned Gases for Stabilizing Preterm Infants at Birth.

OBJECTIVE: To determine whether the use of heated-humidified gases for respiratory support during the stabilization of infants <30 weeks of gestational age (GA) in the delivery room reduces rates of hypothermia on admission to the neonatal intensive care unit (NICU). STUDY DESIGN: A multicenter, unblinded, randomized trial was conducted in Melbourne, Australia, between February 2013 and June 2015. Infants <30 weeks of GA were randomly assigned to receive either heated-humidified gases or unconditioned gases during stabilization in the delivery room and during transport to NICU. Infants born to mothers with pyrexia >38°C were excluded. Primary outcome was rate of hypothermia on NICU admission (rectal temperature <36.5°C). RESULTS: A total of 273 infants were enrolled. Fewer infants in the heated-humidified group were hypothermic on admission to NICU (36/132 [27%]) compared with controls (61/141 [43%], P < .01). There was no difference in rates of hyperthermia (>37.5°C); 20% (27/132) in the heated-humidified group compared with 16% (22/141) in the controls (P = .30). There were no differences in mortality or respiratory outcomes. CONCLUSIONS: The use of heated-humidified gases in the delivery room significantly reduces hypothermia on admission to NICU in preterm infants, without increased risk of hyperthermia. CLINICAL TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Register (www.anzctr.org.au) ACTRN12613000093785.