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.

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).

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.

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.

Diffusion lung imaging with hyperpolarized gas MRI.

Lung imaging using conventional 1 H MRI presents great challenges because of the low density of lung tissue, lung motion and very fast lung tissue transverse relaxation (typical T2 * is about 1-2 ms). MRI with hyperpolarized gases (3 He and 129 Xe) provides a valuable alternative because of the very strong signal originating from inhaled gas residing in the lung airspaces and relatively slow gas T2 * relaxation (typical T2 * is about 20-30 ms). However, in vivo human experiments should be performed very rapidly - usually during a single breath-hold. In this review, we describe the recent developments in diffusion lung MRI with hyperpolarized gases. We show that a combination of the results of modeling of gas diffusion in lung airspaces and diffusion measurements with variable diffusion-sensitizing gradients allows the extraction of quantitative information on the lung microstructure at the alveolar level. From an MRI scan of less than 15 s, this approach, called in vivo lung morphometry, allows the provision of quantitative values and spatial distributions of the same physiological parameters as measured by means of 'standard' invasive stereology (mean linear intercept, surface-to-volume ratio, density of alveoli, etc.). In addition, the approach makes it possible to evaluate some advanced Weibel parameters characterizing lung microstructure: average radii of alveolar sacs and ducts, as well as the depth of their alveolar sleeves. Such measurements, providing in vivo information on the integrity of pulmonary acinar airways and their changes in different diseases, are of great importance and interest to a broad range of physiologists and clinicians. We also discuss a new type of experiment based on the in vivo lung morphometry technique combined with quantitative computed tomography measurements, as well as with gradient echo MRI measurements of hyperpolarized gas transverse relaxation in the lung airspaces. Such experiments provide additional information on the blood vessel volume fraction, specific gas volume and length of the acinar airways, and allow the evaluation of lung parenchymal and non-parenchymal tissue. Copyright © 2015 John Wiley & Sons, Ltd.

Microneedle-Assisted Skin Permeation by Nontoxic Bioengineerable Gas Vesicle Nanoparticles.

Gas vesicle nanoparticles (GVNPs) are hollow, buoyant protein organelles produced by the extremophilic microbe Halobacterium sp. NRC-1 and are being developed as bioengineerable and biocompatible antigen and drug-delivery systems (DDS). Dynamic light scattering measurements of purified GVNP suspensions showed a mean diameter of 245 nm. In vitro diffusion studies using Yucatan miniature pig skin showed GVNP permeation to be enhanced after MN-treatment compared to untreated skin. GVNPs were found to be nontoxic to mammalian cells (human kidney and rat mycocardial myoblasts). These findings support the use of GVNPs as DDS for intradermal/transdermal permeation of protein- and peptide-based drugs.

Higher Fresh Gas Flow Rates Decrease Tidal Volume During Pressure Control Ventilation.

BACKGROUND: We observed that increasing fresh gas flow (FGF) decreased exhaled tidal volume (VT) during pressure control ventilation (PCV). A literature search produced no such description whereby unintended VT changes occur with FGF changes during PCV. METHODS: To model an infant's lungs, 1 lung of a mechanical lung model (Dual Adult TTL 1600; Michigan Instruments, Inc, Grand Rapids, MI) was set at a compliance of 0.0068 L/cm H2O. An Rp50 resistor (27.2 cm H2O/L/s at 15 L/min) simulated normal bronchial resistance. The simulated lung was connected to a pediatric breathing circuit via a 3.5-mm cuffed endotracheal tube. A ventilator with PCV capability (Model 7900; Aestiva, GE Healthcare, Madison, WI) measured exhaled VT, and a flow monitor (NICO; Respironics, Murraysville, PA) measured peak inspiratory flow, positive end-expiratory pressure (PEEP), and peak inspiratory pressure. In PCV mode, exhaled VT displayed by the ventilator at FGF rates of 1, 6, 10, and 15 L/min was manually recorded across multiple ventilator settings. This protocol was repeated for the Avance CS2 anesthesia machine (GE Healthcare). RESULTS: For the Aestiva, higher FGF rates in PCV mode decreased exhaled VT. Exhaled VT for FGFs of 1, 6, 10, and 15 L/min were on average 48, 34.9, 16.5, and 10 mL, respectively, at ventilator settings of inspiratory pressure of 10 cm H2O, PEEP of 0 cm H2O, and respiratory rate of 20 breaths/min. This is a decrease by up to 27%, 65.6%, and 79.2% when FGFs of 6, 10, and 15 L/min are compared with a FGF of 1 L/min, respectively. In the GE Avance CS2 at the same ventilator settings, VT for FGF rates of 1, 6, 10, and 15 L/min were on average 46, 43, 40.4, and 39.7 mL, respectively. The FGF effect on VT was not as pronounced with the GE Avance CS2 as with the GE Aestiva. CONCLUSIONS: FGF has a significant effect on VT during PCV in the Aestiva bellows ventilator, suggesting caution when changing FGF during PCV in infants. Our hypothesis is that at higher FGF rates, an inadvertent PEEP is developed by the flow resistance of the ventilator relief valve that is not recognized by the ventilator. In turn, less change in pressure is needed to reach the set inspiratory pressure, resulting in lower VT delivery at higher FGF rates. This underappreciated FGF-VT interaction during PCV with a bellows ventilator may be clinically significant in pediatric patients; prospective data collection in patients is needed for further evaluation.

Initial respiratory support with cold, dry gas versus heated humidified gas and admission temperature of preterm infants.

OBJECTIVE: To assess whether the addition of heated humidified gas (HHG) at delivery and until neonatal unit arrival improved admission temperatures of preterm infants. STUDY DESIGN: This multicenter, randomized controlled trial was performed in New Zealand and The Netherlands. Infants <32 weeks' gestation who required respiratory support after delivery were randomized to either cold, dry gas or HHG from birth. Standard measures to prevent hypothermia included heated delivery rooms, the use of radiant warmers, body wrap, and head covering. The primary outcome was axillary temperature in the normothermic (36.5-37.5°C) range on admission to a neonatal intensive care unit. Secondary outcomes were measures of respiratory support and neonatal morbidities. The effect of humidification was analyzed by the use of logistic regression. RESULTS: Of 203 randomized infants, 100 received HHG (humidifier set to 37°C) and 103 received cold, dry gas. In the HHG group, 69 (69%) were normothermic compared with 57 (55%) in the cold, dry gas group (unadjusted OR 1.8, 95% CI 1.01-3.19). A greater number of infants <28 weeks were normothermic on admission in the HHG group (24/35; ie, 69%) compared with the cold, dry gas group (16/38; ie, 42%; P = .03). In addition, 2 (2%) infants in the HHG group had admission temperatures <35.5°C compared with 12 (12%) in the cold, dry gas group (P = .007). Respiratory and short-term outcomes were not different. CONCLUSION: Adding HHG during respiratory support in preterm infants from birth increased the incidence of normothermia at admission.

Hydrogen gas reduces hyperoxic lung injury via the Nrf2 pathway in vivo.

Hyperoxic lung injury is a major concern in critically ill patients who receive high concentrations of oxygen to treat lung diseases. Successful abrogation of hyperoxic lung injury would have a huge impact on respiratory and critical care medicine. Hydrogen can be administered as a therapeutic medical gas. We recently demonstrated that inhaled hydrogen reduced transplant-induced lung injury and induced heme oxygenase (HO)-1. To determine whether hydrogen could reduce hyperoxic lung injury and investigate the underlying mechanisms, we randomly assigned rats to four experimental groups and administered the following gas mixtures for 60 h: 98% oxygen (hyperoxia), 2% nitrogen; 98% oxygen (hyperoxia), 2% hydrogen; 98% balanced air (normoxia), 2% nitrogen; and 98% balanced air (normoxia), 2% hydrogen. We examined lung function by blood gas analysis, extent of lung injury, and expression of HO-1. We also investigated the role of NF-E2-related factor (Nrf) 2, which regulates HO-1 expression, by examining the expression of Nrf2-dependent genes and the ability of hydrogen to reduce hyperoxic lung injury in Nrf2-deficient mice. Hydrogen treatment during exposure to hyperoxia significantly improved blood oxygenation, reduced inflammatory events, and induced HO-1 expression. Hydrogen did not mitigate hyperoxic lung injury or induce HO-1 in Nrf2-deficient mice. These findings indicate that hydrogen gas can ameliorate hyperoxic lung injury through induction of Nrf2-dependent genes, such as HO-1. The findings suggest a potentially novel and applicable solution to hyperoxic lung injury and provide new insight into the molecular mechanisms and actions of hydrogen.

[Estimation of some molecular effects of gaseous nitrogen oxide on human blood in vitro].

The aim of this work is complex estimation of the nitric oxide action on whole blood of healthy people. We tested the reaction of whole human blood (n=14) to the processing of it with cold NO-containing plasma. We performed direct sparging of blood samples by gaseous flow with NO in a special plant. Cold NO-containing plasma was generated by apparatus "Plazon" (Russia). We tested lactate dehydrogenase activity in direct and reverse reactions, aldehyde dehydrogenase and superoxide dismutase activity, total protein and lactate level, acid-base balance and the partial pressure of gases in blood. For integral assessment of energy metabolism changes a number of derivative parameters (coefficients of energy reaction balance and substrate provision) were used. Our experiments showed, that the processing of whole human blood with NO-containing gas flow (NO concentration--800 ppm) results in significant changes of its physical and chemical parameters. This exposure leads to inhibition of erythrocytes energy metabolism, decreasing plasma antioxidant reserves, developing moderate ionic disorders and acid-base disbalance in blood samples in vitro.

Porphyrin shell microbubbles with intrinsic ultrasound and photoacoustic properties.

Porphyrin-phospholipid conjugates were used to create photonic microbubbles (MBs) having a porphyrin shell ("porshe"), and their acoustic and photoacoustic properties were investigated. The inclusion of porphyrin-lipid in the MB shell increased the yield, improved the serum stability, and generated a narrow volumetric size distribution with a peak size of 2.7 ± 0.2 µm. Using an acoustic model, we calculated the porshe stiffness to be 3-5 times greater than that of commercial lipid MBs. Porshe MBs were found to be intrinsically suitable for both ultrasound and photoacoustic imaging with a resonance frequency of 9-10 MHz. The distinctive properties of porshe MBs make them potentially advantageous for a broad range of biomedical imaging and therapeutic applications.

Hyperpolarized 129Xe gas lung MRI-SNR and T2* comparisons at 1.5 T and 3 T.

In this study, the signal-to-noise ratio of hyperpolarized (129)Xe human lung magnetic resonance imaging was compared at 1.5 T and 3 T. Experiments were performed at both B(0) fields with quadrature double Helmholtz transmit-receive chest coils of the same geometry with the same subject loads. Differences in sensitivity between the two field strengths were assessed from the signal-to-noise ratio of multi-slice 2D (129)Xe ventilation lung images obtained at the two field strengths with a spatial resolution of 15 mm × 4 mm × 4 mm. There was a systematically higher signal-to-noise ratio observed at 3 T than at 1.5 T by a factor of 1.25. Mean image signal-to-noise ratio was in the range 27-44 at 1.5 T and 36-51 at 3 T. T 2* of (129)Xe gas in the partially inflated lungs was measured to be 25 ms and 18 ms at 1.5 T and 3 T, respectively. T 2* of (129)Xe gas in fully inflated lungs was measured to be 52 ms and 24 ms at 1.5 T and 3 T, respectively.

Inhalation of hydrogen gas attenuates ouabain-induced auditory neuropathy in gerbils.

AIM: Auditory neuropathy (AN) is a hearing disorder characterized by abnormal auditory nerve function with preservation of normal cochlear hair cells. This study was designed to investigate whether treatment with molecular hydrogen (H(2)), which can remedy damage in various organs via reducing oxidative stress, inflammation and apoptosis, is beneficial to ouabain-induced AN in gerbils. METHODS: AN model was made by local application of ouabain (1 mmol/L, 20 mL) to the round window membrane in male Mongolian gerbils. H(2) treatment was given twice by exposing the animals to H(2) (1%, 2%, and 4%) for 60 min at 1 h and 6 h after ouabain application. Before and 7 d after ouabain application, the hearing status of the animals was evaluated using the auditory brainstem response (ABR) approach, the hear cell function was evaluated with distortion product otoacoustic emissions (DPOAE). Seven days after ouabain application, the changes in the cochleae, especially the spiral ganglion neurons (SGNs), were morphologically studied. TUNEL staining and immunofluorescent staining for activated caspase-3 were used to assess the apoptosis of SGNs. RESULTS: Treatment with H(2) (2% and 4%) markedly attenuated the click and tone burst-evoked ABR threshold shift at 4, 8, and 16 kHz in ouabain-exposed animals. Neither local ouabain application, nor H(2) treatment changed the amplitude of DPOAE at 4, 8, and 16 kHz. Morphological study showed that treatment with H(2) (2%) significantly alleviated SGN damage and attenuated the loss of SGN density for each turn of cochlea in ouabain-exposed animals. Furthermore, ouabain caused significantly higher numbers of apoptotic SGNs in the cochlea, which was significantly attenuated by the H(2) treatment. However, ouabain did not change the morphology of cochlear hair cells. CONCLUSION: The results demonstrate that H(2) treatment is beneficial to ouabain-induced AN via reducing apoptosis. Thus, H(2) might be a potential agent for treating hearing impairment in AN patients.

Gas-phase removal of biofilms from various surfaces using carbon dioxide aerosols.

The present study evaluated the removal of Escherichia coli XL1-blue biofilms using periodic jets of carbon dioxide aerosols (a mixture of solid and gaseous CO(2)) with nitrogen gas. The aerosols were generated by the adiabatic expansion of high-pressure CO(2) gas through a nozzle and used to remove air-dried biofilms. The areas of the biofilms were measured from scanning electron micrographs before and after applying the aerosols. The removal efficiency of the aerosol treatment was measured with various air-drying times of the biofilms before the treatment, surface materials, and durations of CO(2) aerosols in each 8-s aerosol-nitrogen cleaning cycle. Nearly 100% of the fresh biofilms were removed from the various surfaces very reliably within 90 s. This technique can be useful for removing unsaturated biofilms on solid surfaces and has potential applications for cleaning bio-contaminated surfaces.

Effects of CO(2) pneumoperitoneum on peritoneal macrophage function and peritoneal metastasis in mice with gastric cancer.

BACKGROUND: Whether laparoscopy with CO(2) pneumoperitoneum affects the peritoneal metastasis of gastric cancer is a pressing question. In light of the important impact change in peritoneal macrophage function has on the peritoneal metastasis of gastric cancer, this study investigated the change in peritoneal macrophage function in gastric cancer in the CO(2) pneumoperitoneum environment, as well as its effect on the peritoneal metastasis of gastric cancer. METHODS: An orthotopic transplantation model of murine forestomach carcinoma was established using the 615 mouse line. The mice bearing tumors were randomly divided into four groups (30 mice each group): anesthesia alone, laparotomy, mini-laparotomy, and CO(2) insufflation. After the operation, peritoneal macrophages were collected from 6 mice in each group and cultured. The phagocytosis of neutral red by macrophages and the levels of NO, TNF-α, IL-10, and VEGF produced by macrophages were measured after 12, 24, 48, and 72 h of culture. The remaining mice were observed after 2 weeks for the rate of peritoneal metastasis of forestomach carcinoma cells and the total weight of implanted nodules. RESULTS: In the laparotomy group, 4 mice died intraoperatively and 2 died in the CO(2) insufflation group. The uptake of neutral red by peritoneal macrophages and the levels of NO, TNF-α, IL-10, and VEGF secreted by peritoneal macrophages in the laparotomy group and mini-laparotomy group after 12 h of culture were all significantly higher than those in the anesthesia-alone group (p < 0.05). The corresponding levels in the CO(2) insufflation group after 12 h were all significantly lower than those in the anesthesia-alone group (p < 0.05). There were no significant differences among the four groups at 24, 48, and 72 h after culture. Comparing with those in the laparotomy group, the uptake of neutral red by peritoneal macrophages and the levels of NO, TNF-α, IL-10, and VEGF secreted by peritoneal macrophages in the CO(2) insufflation group were all significantly lower after 12 h of culture (p < 0.05), but did not differ significantly at 24, 48, and 72 h of culture (p > 0.05), and did not differ significantly in the mini-laparotomy group at all the time (p > 0.05). The rate of peritoneal metastasis of mouse forestomach carcinoma was 50% in the laparotomy group, 45.83% in the mini-laparotomy group, and 45.45% in the CO(2) insufflation group; this difference was not statistically significant (p > 0.05). The total weight of implanted nodules of mouse forestomach carcinoma was 1.02 ± 0.38 g in the laparotomy group, 0.97 ± 0.41 g in the mini-laparotomy group, and 0.93 ± 0.45 g in the CO(2) insufflation group, which was not a statistically significant difference (p > 0.05). CONCLUSION: CO(2) pneumoperitoneum neither significantly changes the phagocytosis and cytokine secretion functions of peritoneal macrophages in gastric cancer-bearing mice nor significantly promotes peritoneal metastasis of gastric cancer.

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.

Residual triamcinolone acetonide sequestered in the fovea after macular hole repair.

PURPOSE: To report the macular hole closure rate and visual outcomes of patients with residual triamcinolone acetonide in the fovea after macular hole repair. METHODS: We reviewed the medical records of consecutive patients who underwent macular hole surgery at our institution between 2005 and 2008. Only patients with visible triamcinolone in the fovea in the first postoperative month were included. RESULTS: Six patients with Stage III or IV macular holes were included. All patients underwent pars plana vitrectomy, internal limiting membrane peeling, and gas tamponade. Triamcinolone acetonide was used to visualize the vitreous in every patient, and diluted indocyanine green was used to stain the internal limiting membrane in five patients. The median preoperative best-corrected visual acuity was 20/200, which improved to a median of 20/40 at the last follow-up. Five patients eventually developed retinal pigment epithelial alterations. Anatomic hole closure was achieved in every patient. The mean follow-up was 23 months (range, 3-36 months). CONCLUSION: Residual triamcinolone sequestered in the fovea after macular hole surgery did not affect hole closure or prevent improvement in visual acuity. It is unclear whether the retinal pigment epithelial alterations in our patients represent toxicity or are unrelated to the triamcinolone exposure.

Intravitreous injection of bevacizumab, tissue plasminogen activator, and gas in the treatment of submacular hemorrhage in age-related macular degeneration.

PURPOSE: To investigate the benefit of adding bevacizumab to intravitreal recombinant tissue plasminogen activator (rTPA) and gas as initial therapy in subretinal hemorrhage and choroidal neovascularization because of age-related macular degeneration. METHODS: Thirty-eight consecutive patients with recent (1-31 days) subretinal hemorrhage who were treated with intravitreal rTPA and gas (26 patients) or with intravitreal bevacizumab, rTPA, and gas (12 patients) were included in this retrospective analysis. In all patients, a standardized antivascular endothelial growth factor therapy was followed. Testing of best-corrected visual acuity, biomicroscopy, and fundus examination were performed at 4 weeks and 7 months. RESULTS: The mean pretreatment best-corrected visual acuity in the rTPA/gas group was 0.08 ± 0.09 and 0.12 ± 0.13 in the bevacizumab/rTPA/gas group. After 4 weeks, it was significantly higher in the bevacizumab/rTPA/gas group (0.25 ± 0.26) than in the rTPA/gas (0.08 ± 0.1) group (P < 0.05). Also, after 7 months, best-corrected visual acuity was significantly higher in the bevacizumab/rTPA/gas group (0.07 ± 0.07 vs. 0.24 ± 0.35; P < 0.05). Reading vision could be restored in 0% (rTPA/gas) versus 50% (bevacizumab/rTPA/gas). Stabilization (0 ± 2 lines) or improvement of best-corrected visual acuity was obtained in 62% (rTPA/gas) versus 84% (bevacizumab/rTPA/gas). CONCLUSION: From our retrospective pilot study, there is a strong indication that the addition of intravitreal bevacizumab is safe and superior to the displacement of submacular hemorrhages alone with rTPA and gas.