Colonic oxygen microbubbles augment systemic oxygenation and CO2 removal in a porcine smoke inhalation model of severe hypoxia

Inhalation injury can lead to pulmonary complications resulting in the development of respiratory distress and severe hypoxia. Respiratory distress is one of the major causes of death in critically ill patients with a reported mortality rate of up to 45%. The present study focuses on the effect of oxygen microbubble (OMB) infusion via the colon in a porcine model of smoke inhalation-induced lung injury. Juvenile female Duroc pigs (n = 6 colonic OMB, n = 6 no treatment) ranging from 39 to 51 kg in weight were exposed to smoke under general anesthesia for 2 h. Animals developed severe hypoxia 48 h after smoke inhalation as reflected by reduction in SpO₂ to 66.3 ± 13.1% and PaO₂ to 45.3 ± 7.6 mmHg, as well as bilateral diffuse infiltrates demonstrated on chest X-ray. Colonic OMB infusion (75-100 mL/kg dose) resulted in significant improvements in systemic oxygenation as demonstrated by an increase in PaO₂ of 13.2 ± 4.7 mmHg and SpO₂ of 15.2 ± 10.0% out to 2.5 h, compared to no-treatment control animals that experienced a decline in PaO₂ of 8.2 ± 7.9 mmHg and SpO₂ of 12.9 ± 18.7% over the same timeframe. Likewise, colonic OMB decreased PaCO₂ and PmvCO₂ by 19.7 ± 7.6 mmHg and 7.6 ± 6.7 mmHg, respectively, compared to controls that experienced increases in PaCO₂ and PmvCO₂ of 17.9 ± 11.7 mmHg and 18.3 ± 11.2 mmHg. We conclude that colonic delivery of OMB therapy has potential to treat patients experiencing severe hypoxemic respiratory failure.

RF11 | PSAT272 Suppressive Tumor Immune Microenvironment is Associated with Aggressive Differentiated Thyroid Cancer

Background

The incidence of differentiated thyroid cancer (DTC) has tripled over the last 30 years in the US. While most patients respond to conventional treatment, some have an aggressive course with a dismal 5-year survival of 15.3%. There is a need to identify novel markers in addition to clinico-pathologic criteria to better prognosticate DTC patients. In addition, exploration of immunotherapies in advanced DTC underlies the critical need to investigate the immune interface of DTC to identify potential therapeutic targets and those likely to respond to immunotherapies.

Aims

We aimed to identify tumor-infiltrating immune cells and checkpoints [programmed cell death protein 1 (PD-1) and its ligand (PD-L1)] associated with DTC and investigate their association with metastatic and advanced DTC.

Methods

We performed multiplex immunofluorescence on de-paraffinized thyroid tissue collected at initial thyroidectomy from 17 adults with DTC. We identified cell-surface molecules to characterize the tumor immune microenvironment for leukocytes (CD45+), T cells (CD3+), B cells (CD19+), natural killer cells (CD56+), T regulatory cells (CD3+FOXP3+), CD4+ T cells (CD3+CD4+), CD8+ T cells (CD3+CD8+), macrophages (CD68+), M2 macrophages (CD68+CD163+), and immune checkpoints PD-1 and PD-L1. Tonsil tissue was used as positive control. Immunofluorescence staining was quantified by cell counting HALO software. We compared the mean percentage expression of immune markers between tumor and adjacent thyroid tissue from the same patient by paired t-test, and in exploratory analysis between intra-tumoral tissue in patients with versus without distant metastases by student's t-test; p value<0.05 was used for significance.

Results

Overall, in 17 DTC patient samples, most leukocyte infiltrate occurred along the leading edge of the tumor and in the peritumoral thyroid tissue. Immune checkpoints PD-1 and PD-L1 were highly expressed in the tumor as compared to adjacent thyroid tissue (p<0.05). A higher trend for M2 macrophages was observed in the tumor but was not statistically significant. Intra-tumoral expressions of T regulatory cells, macrophages and PD-L1+ cells were more in samples for DTC patients with metastases (n=3) as compared to those without (n=14).

Conclusions

Immune profiling demonstrated significant differences between tumor and adjacent thyroid tissue, particularly for PD-1 and PD-L1, indicating their role in DTC occurrence. Intra-tumor infiltration of T regulatory cells, macrophages and PD-L1+ cells was more in metastatic DTC indicating their potential role in aggressive behavior of DTC. These data suggest that suppressive tumor immune microenvironment portends more aggressive behavior of DTC, and that specific immune suppressive markers may be potential therapeutic targets. We are continuing to expand our sample size to have adequate power for comparing groups with various clinico-pathologic severities and analyzing the role of pro-tumoral M2 macrophages in DTC prognosis.

Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m., Saturday, June 11, 2022 1:36 p.m. - 1:41 p.m.

Sinonasal IgG4-related sclerosing disease: A rare entity and challenging diagnosis

Objectives

To describe the rare presentation, imaging and histological findings, and treatments in patients with IgG4-related disease (IgG4-RD) and diagnostic pitfalls and difficulties.

Methods

Cases of sinonasal IgG4-RD were retrieved, and clinicopathological features were reviewed.

Results

Seven cases of sinonasal IgG4-RD were identified over an 11-year period, including four males and three females, with an age range of 19-66 years (median 58 years). Patients presented with symptoms related to the mass effect of the lesions or the destructive nature of the disease including fullness, swelling, obstruction, and pain. Serum IgG and IgG4 levels, IgG/IgG4 ratios, storiform fibrosis, obliterative phlebitis, and plasma cell infiltration were seen in varying proportions. Bony erosion and tissue inflammation were present in some cases.

Conclusion

Sinonasal IgG4-RD is exceedingly rare among other IgG4-RD and varied in its clinical presentation thus posing as a clinically difficult disease to diagnosis. Proper clinical, pathological, and immunohistopathological analysis is required for accurate diagnosis. Such disease should be considered in all cases of similar presentation to those in this study.Level of Evidence: 4.

Occurrence of the off-host life stages of Tunga penetrans (Siphonaptera) in various environments in Brazil

To explore the local transmission dynamics of Tunga penetrans in brazil, 134 soil samples from various environments were collected in three different endemic regions of the country and checked for the presence of the flea's larvae, pupae and adults. the samples, which came from an urban slum in the north-east, a village of xavante indians in the central-west and a community of yanomami indians living in traditional longhouses (malocas) in the north, were categorized as indoor, outdoor or indoor-outdoor (the latter representing samples collected in the malocas). The proportion of samples found positive for T. penetrans was lowest in the slum (9.3%) and highest in the Yanomami village (32.0%; P=0.01). Soil samples collected below bedsteads or hammocks or from the indoor resting places of dogs were significantly more likely to be positive than the indoor samples collected at other sites (65.0% v. 35.0%; P=0.02). There was no evidence indicating that the presence of T. penetrans in a soil sample was markedly affected by soil temperature, air temperature or air humidity. As no life stages of T. penetrans were found in any outdoor sample, it seems likely that, in resource-poor settings in Brazil, most transmission of T. penetrans occurs indoors. Control measures against the off-host life stages of T. penetrans should therefore be targeted at particular indoor micro-environments.

A theoretical study of nonlinearity in heterocyclic hydrogen-bonded complexes

Ab initio calculations are performed at the MP2/6-311++G(d,p) and DFT/B3LYP/6-311++G(d,p) theoretical levels to obtain geometries, H-bond energies and harmonic infrared vibrational properties for the Cs symmetry structures of heterocyclic hydrogen-bonded complexes, CnHmY-HX. The H-bond lengths in DFT/B3LYP calculation level are in better agreement with the experimental values than the MP2 results. The geometry optimization are interpreted in terms of hydrogen bond nonlinearity represented by theta; and phi angles, once the hydrogen bond is formed among n-electrons pairs of the heteroatom in heterocyclic and the hydrogen atom in HX. The hydrogen bond energy after of the zero-point vibrational energy (ZPE) and basis set superposition error (BSSE) corrections are overestimated at DFT/B3LYP, whereas the MP2 BSSE corrections are very large than corresponding DFT/B3LYP. For example, the BSSE corrections for the C2H4S-HNC complex are 7.60 and 0.09 kJ mol(-1) in MP2 and DFT/B3LYP calculations levels, respectively. The new vibrational modes in infrared harmonic spectrum arising from complexation show several interesting features, especially the intermolecular stretching mode.

An MP2 and DFT study of heterocyclic hydrogen complexes CnHmY-HX with n=2, m=4 or 5, Y=O, S or N and X=F or Cl

We present a theoretical study through MP2 ab initio molecular orbital calculations and B3LYP density functional theory with the 6-311++G(d,p) basis set of the heterocyclic hydrogen complexes, CnHmY-HX, where CnHmY = C2H4O, C2H5N and C2H4S, and X=F or Cl. This study aided in the elucidation the main changes in the structural, electronic and the vibrational properties in isolated species, due the hydrogen complexes formation, CnHmY-HX, revealing systematic tendencies in these chemical systems studied. The complexes has CS symmetry, with the HX subunit lying in the plane perpendicular to that of CYC nuclei of heterocyclic and acting as proton donor in forming a hydrogen bond to the heteroatom, Y. A weak secondary interaction between the CH2 groups of heterocyclics and the X atoms in HX causes a significant nonlinearity of the primary hydrogen bond. The hydrogen bond linearity deviations in these complexes due to secondary interactions are represented by theta angle. The MP2 intermolecular distances of complexes C2H5N-HF, C2H4O-HF and C2H4S-HF correspond the 1.652, 1.671 and 2.164 A, respectively, these results are in excellent agreement with experimental results of 1.700 and 2.193 A found for the last two complexes. In the same way, the MP2 values to theta angle, 14.7, 19.1 and 16.8 degrees, has a better reproduction in the experimental results of 16.5, 21.0 and 16.8 degrees, get to the C2H4O-HCl, C2H4S-HCl and C2H4S-HF complexes, respectively.