[Can mesh nebulizers improve prehospital aerosol therapy? An in vitro study on simulated prehospital emergency patients suffering from respiratory distress]. / Können Mesh-Vernebler die prähospitale Aerosoltherapie verbessern? Eine In-vitro-Studie an simulierten Notfallpatient*innen mit Atemnot.

BACKGROUND: Nebulizers used to treat prehospital emergency patients should provide a high output efficiency to achieve a fast onset of therapeutic drug effects while remaining unaffected by the presence of supplementary oxygen flow or the patient's breathing pattern. On the other hand, nebulizer performance is directly influenced by differences in device design, gas flow and patients' breathing patterns. Several studies from emergency departments were able to demonstrate an improvement in patient outcome when using a mesh nebulizer instead of a jet nebulizer. Data or bench studies regarding prehospital care are non-existent. OBJECTIVE: The aim of the present in vitro study was to evaluate which type of aerosol generator would best address the requirements of a prehospital adult emergency patient suffering from respiratory distress. MATERIAL AND METHODS: We evaluated the performance of a jet nebulizer (Cirrus™ 2, Intersurgical®) and two mesh nebulizers (Aerogen Solo® with USB controller, Aerogen Limited and M­Neb® mobile, NEBU-TEC International med. Produkte Eike Kern GmbH) with the possibility of portable operation in an in vitro model of a spontaneously breathing adult emergency patient. One physiological and three pathological breathing patterns (distressed breathing pattern as well as stable and acute exacerbated chronic obstructive pulmonary disease) were simulated. Nebulizer output and salbutamol lung deposition were measured at different oxygen flow rates using a face mask as the delivery interface. RESULTS: The mesh nebulizers produced a significantly higher aerosol output when compared to the jet nebulizer. The M­Neb® mobile was able to significantly exceed the output of the Aerogen Solo®. Oxygen flow had the largest influence on the output of the jet nebulizer but hardly affected the mesh nebulizers. After a nebulization time of 10 min the M­Neb® mobile also achieved the highest total salbutamol lung deposition (P < 0.001). Aerosol drug deposition was therefore mainly determined by the nebulizer's drug output per unit time. The deposition could not be improved using a spacer but was strongly influenced by the simulated emergency patients' breathing pattern. CONCLUSION: The use of mesh nebulizers might have the potential to improve the aerosol therapy of prehospital emergency patients. In general, mesh nebulizers seem to be superior to jet nebulizers regarding aerosol output per unit time and total lung deposition. The present data suggest that aerosol output and drug deposition to the collection filter in this simulated setting are closely connected and crucial for total salbutamol deposition, as the deposition could not be improved by adding a spacer. Aerosol drug deposition in simulated emergency patients' lungs is therefore mainly determined by the nebulizer's drug output per unit time. The level of oxygen flow used had the largest influence on the output of the jet nebulizer but hardly affected the output of the tested mesh nebulizers. Mesh nebulizers could therefore enable a demand-adapted oxygen therapy due to their consistent performance despite the presence of oxygen flow. A high respiratory rate was associated with a high drug deposition, which is clinically desirable in the treatment of patients in respiratory distress; however, drug underdosing must also be expected in the treatment of bradypneic patients. Further clinical studies must prove whether our findings also apply to the treatment of real prehospital emergency patients.

Longitudinal humoral response after SARS-CoV-2 vaccination in ocrelizumab treated MS patients: To wait and repopulate?

OBJECTIVE: The objective of this study was to measure humoral responses after SARS-CoV-2 vaccination in MS patients treated with ocrelizumab (OCR) compared to MS patients without disease modifying therapies (DMTs) in relation to timing of vaccination and B-cell count. METHODS: OCR treated patients were divided into an early and a late group (cut-off time 12 weeks between infusion and first vaccination). Patients were vaccinated with mRNA-1273 (Moderna). B-cells were measured at baseline (time of first vaccination) and SARS-CoV-2 antibodies were measured at baseline, day 28, 42, 52 and 70. RESULTS: 87 patients were included (62 OCR patients, 29 patients without DMTs). At day 70, seroconversion occurred in 39.3% of OCR patients compared to 100% of MS patients without DMTs. In OCR patients, seroconversion varied between 26% (early group) to 50% (late group) and between 27% (low B-cells) to 56% (at least 1 detectable B-cell/µL). CONCLUSIONS: Low B-cell counts prior to vaccination and shorter time between OCR infusion and vaccination may negatively influence humoral response but does not preclude seroconversion. We advise OCR treated patients to get their first vaccination as soon as possible. In case of an additional booster vaccination, timing of vaccination based on B-cell count and time after last infusion may be considered.

High-Throughput Fluorescence Polarization Assay to Identify Ligands Using Purified G Protein-Coupled Receptor.

The development of cell-free high-throughput (HT) methods to screen and select novel lead compounds remains one of the key challenges in G protein-coupled receptor (GPCR) drug discovery. Mutational approaches have allowed the stabilization of GPCRs in a purified and ligand-free state. The increased intramolecular stability overcomes two major drawbacks for usage in in vitro screening, the low receptor density on cells and the low stability in micelles. Here, an HT fluorescence polarization (FP) assay for the neurotensin receptor type 1 (NTS1) was developed. The assay operates in a 384-well format and is tolerant to DMSO. From a library screen of 1272 compounds, 12 (~1%) were identified as primary hits. These compounds were validated in orthogonal assay formats using surface plasmon resonance (SPR), which confirmed binding of seven compounds (0.6%). One of these compounds showed a clear preference for the orthosteric binding pocket with submicromolar affinity. A second compound revealed binding at a nonorthosteric binding region and showed specific biological activity on NTS1-expressing cells. A search of analogs led to further enhancement of affinity, but at the expense of activity. The identification of GPCR ligands in a cell-free assay should allow the expansion of GPCR pharmaceuticals with antagonistic or agonistic activity.

Virtual memory CD8 T cells expanded by helminth infection confer broad protection against bacterial infection.

Epidemiological data and animal studies suggest that helminth infection exerts potent immunomodulatory effects that dampen host immunity against unrelated pathogens. Despite this notion, we unexpectedly discovered that prior helminth infection resulted in enhanced protection against subsequent systemic and enteric bacterial infection. A population of virtual memory CD8 T (CD8 TVM) cells underwent marked expansion upon infection with the helminth Heligmosomoides polygurus by an IL-4-regulated, antigen-independent mechanism. CD8 TVM cells disseminated to secondary lymphoid organs and established a major population of the systemic CD8 T cell pool. IL-4 production elicited by protein immunization or selective activation of natural killer T cells also results in the expansion of CD8 TVM cells. Notably, CD8 TVM cells expanded by helminth infection are sufficient to transfer innate non-cognate protection against bacteria to naïve animals. This innate non-cognate "collateral protection" mediated by CD8 TVM might provide parasitized animals an advantage against subsequent unrelated infections, and represents a potential novel strategy for vaccination.

In situ assays demonstrate that interferon-gamma suppresses infection-stimulated hepatic fibrin deposition by promoting fibrinolysis.

BACKGROUND: Inflammatory cytokines potently impact hemostatic pathways during infection, but the tissue-specific regulation of coagulation and fibrinolysis complicates studies of the underlying mechanisms. METHODS AND RESULTS: Here, we describe assays that quantitatively measuring prothrombinase (PTase), protein C-ase (PCase) and plasminogen activator (PA) activities in situ, thereby facilitating studies of tissue-specific hemostasis. Using these assays, we investigate the mechanisms regulating hepatic fibrin deposition during murine toxoplasmosis and the means by which interferon-gamma (IFN-gamma) suppresses infection-stimulated fibrin deposition. We demonstrate that Toxoplasma infection upregulates hepatic PTase, PCase, and PA activity. Wild type and gene-targeted IFN-gamma-deficient mice exhibit similar levels of infection-stimulated PTase activity. By contrast, IFN-gamma-deficiency is associated with increased PCase activity and reduced PA activity during infection. Parallel analyses of hepatic gene expression reveal that IFN-gamma-deficiency is associated with increased expression of thrombomodulin (TM), a key component of the PCase, increased expression of thrombin-activatable fibrinolysis inhibitor (TAFI), a PC substrate, and reduced expression of urokinase PA (u-PA). CONCLUSIONS: These findings suggest that IFN-gamma suppresses infection-stimulated hepatic fibrin deposition by suppressing TM-mediated activation of TAFI, thereby destabilizing fibrin deposits, and concomitantly increasing hepatic u-PA activity, thereby promoting fibrinolysis. We anticipate that further application of these in situ assays will improve our understanding of tissue-specific hemostasis, its regulation by cytokines, and its dysregulation during coagulopathy.

Unrecognised transmission of tuberculosis in prisons.

BACKGROUND: Tuberculosis (TB) is a public health concern in correctional facilities. High turnover of inmate populations may preclude timely diagnosis of TB, so that unrecognised transmission may be common. OBJECTIVE: To determine the proportion of inmates with new skin test conversions who had identifiable exposure to diagnosed cases of TB in the correctional system, and to test the hypothesis that source cases of TB may be undiagnosed during incarceration. SETTING: Maryland Division of Corrections, USA. SUBJECTS: All inmates whose skin test converted from negative to positive at annual screening. DESIGN: All cases of TB in inmates, diagnosed in the prisons during the relevant time period, were identified. Movements of skin test converters and potential source cases within the prisons were matched. We then matched all inmates discharged from the prison system with all new cases of tuberculosis notified to the Maryland Department of Health & Mental Hygiene tuberculosis registry in 1994. RESULTS: The inmate turnover was 21% per year. Probable exposure to a diagnosed source case was found in 13% of converters, possible exposure in 10% and no exposure in 72%. In a further 5% exposure status could not be determined. We identified four cases of pulmonary tuberculosis notified to the state in 1994, within 3 months of discharge in released inmates, who were not known to have tuberculosis whilst incarcerated. CONCLUSIONS: Significant transmission of TB due to undiagnosed index cases may occur in prisons due to high population turnover. New skin test conversions in inmates should be treated as new infection, even in the absence of identifiable exposure to TB.

Compliance with universal precautions in correctional health care facilities.

There were three main objectives of this cross-sectional study of Maryland State correctional health care workers. The first was to evaluate compliance with work practices designed to minimize exposure to blood and body fluids; the second, to identify correlates of compliance with universal precautions (UPs); and the third was to determine the relationship, if any, between compliance and exposures. Of 216 responding health care workers, 34% reported overall compliance across all 15 items on a compliance scale. Rates for specific items were particularly low for use of certain types of personal protective equipment, such as protective eyewear (53.5%), face mask (47.2%) and protective clothing (33.9%). Compliance rates were highest for glove use (93.2%) waste disposal (89.8%), and sharps disposal (80.8%). Compliance rates were generally not associated with demographic factors, except for age; younger workers were more likely to be compliant with safe work practices than were older workers (P < 0.05). Compliance was positively associated with several work-related variables, including perceived safety climate (i.e., management's commitment to infection control and the overall safety program) and job satisfaction, and was found to be inversely associated with security-related work constraints, job/task factors, adverse working conditions, workplace discrimination, and perceived work stress. Bloodborne exposures were not uncommon; 13.8% of all respondents had at least one bloodborne exposure within the previous 6 months, and compliance was inversely related to blood and body fluid exposures. This study identified several potentially modifiable correlates of compliance, including factors unique to the correctional setting. Infection-control interventional strategies specifically tailored to these health care workers may therefore be most effective in reducing the risk of bloodborne exposures.

Impact of tuberculosis control measures and crowding on the incidence of tuberculous infection in Maryland prisons.

Our aim was to determine the incidence of tuberculin skin test (TST) conversion in the Maryland state correctional system. We conducted a historical longitudinal cohort study. A sample of 1,289 inmates, incarcerated in 16 of 23 prisons, who had a negative TST and a second test within 24 months was selected. The incidence of recent conversion was 6.3 per 100 person-years. Risk factors for conversion included high prison-population density (relative risk [RR] = 2.4; 95% confidence interval [CI], 1.5-3.8) and incarceration in a higher-security institution (RR = 2.4; 95% CI, 1.4-4.3). Incarceration in an institution with higher levels of isoniazid prophylaxis (> 65% of TST positives) reduced the risk of infection by 50% (RR = 0.5; 95% CI, 0.3-0.7). Crowding was strongly correlated with risk of conversion (r = 0.83; P < .001), while rates of isoniazid prophylaxis initiation were inversely correlated with risk of infection (r = -0.82; P < .001). In stepwise regression, higher prison-population density was the strongest predictor of increased infection. In a final model, inclusion of the rate of isoniazid prophylaxis initiation reduced the risk associated with crowding (RR = 1.4; P = .4). Annual screening programs for prisons can identify recent conversions that may not otherwise be detected.

Profile of HIV seropositive inmates diagnosed in Maryland's state correctional system.

Correctional systems increasingly serve as the health care nexus for the initial diagnosis and treatment of human immunodeficiency virus (HIV) infection, particularly among traditionally underserved populations. A survey was conducted to describe the clinical profile of inmates in a State correctional system diagnosed with HIV infection by various testing strategies. Approximately 50 percent of the inmates diagnosed were potential candidates for anti-retroviral therapy, and 17 percent were severely immunocompromised. Implementation of voluntary HIV testing at prison entry increased the number of persons identified with HIV infection; however, since volunteers at entry had higher CD4 cell counts compared with infected inmates diagnosed by other methods, there was not a parallel increase in the percentage requiring immediate medical treatment. These data are important for planning medical resources in the correctional setting and underscore the opportunity to provide prevention and therapy for a vulnerable population with HIV infection. Public health interventions within the correctional setting have a broader societal impact, since most infected inmates serve short sentences (median, 3 years). Clinical case management is critical for inmates with HIV infection released to the community so that linkages with primary care providers and support services can be established.