Factors influencing CDC- recommended preventative behaviors through the COVID-19 pandemic in college students.

Objective: To understand how student perceptions of physical health and generalized concern about infection influenced engagement in COVID-19 preventive behaviors. Participants: 418 full-time undergraduate and graduate students attending a public university in South Carolina, USA. Methods: A self-administered survey was distributed during the 2020-2021 academic year. The health belief model, structural equation modeling, and regression methods were used to evaluate associations between students' perceived physical health and the use of CDC-recommended mitigation strategies. Results: Our findings suggest that an individual's perception of their own physical health impacted engagement in preventive behaviors by influencing concerns about disease severity (p = 0.01) and susceptibility (p = 0.03). However, perceived physical health was not associated with perceived benefits (p = 0.21), barriers (p = 0.57), or self-efficacy (p = 0.62) of mitigation strategies. Conclusions: Intrapersonal factors may play a strong role in the way a student undertakes disease control and prevention.

ICESat-2/ATLAS Onboard Flight Science Receiver Algorithms: Purpose, Process, and Performance.

The Advanced Topographic Laser Altimetry System (ATLAS) is the sole instrument on the Ice, Cloud, and land Elevation Satellite 2 (ICESat-2). Without some method of reducing the transmitted data, the volume of ATLAS telemetry would far exceed the normal X-band downlink capability or require many more ground station contacts. The ATLAS Onboard Flight Science Receiver Algorithms (hereinafter Receiver Algorithms or Algorithms) control the amount of science data that is telemetered from the instrument, limiting the data volume by distinguishing surface echoes from background noise, and allowing the instrument to telemeter data from only a small vertical region about the signal. This is accomplished through the transfer of the spacecraft's location and attitude to the instrument every second, use of an onboard Digital Elevation Model, implementation of signal processing techniques, and use of onboard relief and surface type reference maps. Extensive ground testing verified the performance of the Algorithms. On-orbit analysis shows that the Algorithms are working as expected from the ground testing; they are performing well and meeting the mission requirements.

Implementation of nutrition risk screening using the Malnutrition Universal Screening Tool across a large metropolitan health service.

BACKGROUND: A standardised nutrition risk screening (NRS) programme with ongoing education is recommended for the successful implementation of NRS. This project aimed to develop and implement a standardised NRS and education process across the adult bed-based services of a large metropolitan health service and to achieve a 75% NRS compliance at 12 months post-implementation. METHODS: A working party of Monash Health (MH) dietitians and a nutrition technician revised an existing NRS medical record form consisting of the Malnutrition Universal Screening Tool and nutrition management guidelines. Nursing staff across six MH hospital sites were educated in the use of this revised form and there was a formalised implementation process. Support from Executive Management, nurse educators and the Nutrition Risk Committee ensured the incorporation of NRS into nursing practice. Compliance audits were conducted pre- and post-implementation. RESULTS: At 12 months post-implementation, organisation-wide NRS compliance reached 34.3%. For those wards that had pre-implementation NRS performed by nursing staff, compliance increased from 7.1% to 37.9% at 12 months (P < 0.001). The improved NRS form is now incorporated into standard nursing practice and NRS is embedded in the organisation's 'Point of Care Audit', which is reported 6-monthly to the Nutrition Risk Committee and site Quality and Safety Committees. CONCLUSIONS: NRS compliance improved at MH with strong governance support and formalised implementation; however, the overall compliance achieved appears to have been affected by the complexity and diversity of multiple healthcare sites. Ongoing education, regular auditing and establishment of NRS routines and ward practices is recommended to further improve compliance.

Screening and monitoring coeliac disease: multicentre trial of a new serum antibody test kit.

A multicentre trial was conducted to evaluate a new test for anti-gliadin antibodies (AGA) in serum (Coeliac Screening Kit, CSK, Medical Innovations Limited, Artarmon, NSW, Australia). The test showed excellent reproducibility for both anti-gliadin IgA and IgG detection. The average intraassay coefficient of variation (CV) was 3.0% for IgA and 2.4% for IgG (n = 6), while the average interassay CV was 6.4% for IgA and 4.3% for IgG (n = 3). By defining a positive test as both IgA and IgG elevated, a sensitivity of 93% in untreated coeliacs (n = 75) was observed. The corresponding specificities in healthy adults (n = 130) and healthy children (n = 77) were > 99% and 100% respectively, while in patients with other gastrointestinal disorders (disease controls) the specificity was 94% (n = 129). The test was also useful in monitoring patients, with anti-gliadin IgA and IgG falling for up to a year after commencing a gluten-free diet (GFD) (12 adults). In some patients however, antibody levels did not reach the normal cutpoint after many months on a GFD, which may reflect the patients' poor adherence to their gluten free diet. The test was superior to the Pharmacia anti-gliadin ELISA, and should be useful as an aid to the diagnosis of coeliac disease, as well as in the follow-up of treated patients.

Evaluation of MSA as a serum marker in breast cancer: a comparison with CEA.

In a blind study, 518 serum samples were assayed for serum levels of mammary serum antigen (MSA) by an enzyme immunoassay (EIA) using the 3E1.2 monoclonal antibody. Using 300 IU as the arbitrary cut off to distinguish normal from abnormal individuals, 75% of patients with primary Stage I carcinoma of the breast (n = 12), 89% of those with Stage II (n = 9) and 93% of those with Stage IV (n = 57) had elevated levels of MSA. A relationship was observed between the level of MSA and stage of disease, and therefore with the extent of tumour burden. Levels of MSA were also determined in a series of 19 patients undergoing chemotherapy for breast cancer. Over a 2-24 month period, the change of MSA levels corresponded with the clinical course of the disease in 17 (89%) cases. MSA levels were also raised in some patients with ovarian, colon, lung and kidney cancer, but the average level was lower than in patients with breast cancer. A comparison of CEA and MSA levels in these patients revealed that MSA was a substantially better marker for breast cancer than CEA. The results of this study demonstrate that MSA levels are elevated in patients with breast cancer and may provide a useful means of following the clinical course of patients with this disease.

Mammary serum antigen (MSA) levels as a marker for breast cancer: a survey of blood donors and patients with cancer.

A murine monoclonal antibody (3E1.2) to human breast carcinoma cells was made. The antibody, which was selected for its ability to react with formalin fixed sections of the immunizing tissue, detects an antigen in the serum of breast cancer patients which we have called Mammary Serum Antigen. Immunoperoxidase staining has shown that there is an increased expression of this antigen on malignant breast epithelium compared to normal breast epithelium and other normal tissues. An assay (a serum inhibition enzyme immunoassay) using this antibody has been established to determine levels of MSA in patients' sera. Two independent studies involving greater than 2,000 blood donors and greater than 400 patients with breast cancer have shown that MSA is elevated in patients with carcinoma of the breast. MSA levels were found to be raised in approx. 2% of blood donors, approx. 55% of patients with localised breast cancer (Stage I and II) and in approx. 85% of patients with advanced breast cancer (Stage III and IV). Raised levels were also found in some patients with benign breast disease and other tumors, however these were generally much lower than those found in breast cancer patients. MSA levels may therefore be of some use for the monitoring of breast cancer patients, and as a diagnostic aid to screen populations for breast cancer.

Preparation and characterization of human bone marrow-derived macrophages.

Bone marrow-derived macrophages were prepared from human bone marrow mononuclear cells following cultivation in GCT-conditioned medium (GCT-CM) and purification by adherence to fibronectin-coated flasks. The growth of bone marrow mononuclear cells in GCT-CM was dependent on the shape of the culture vessels, being increased in round-bottomed versus flat-bottomed wells. Proliferation was confined to nonadherent cells; like blood monocytes, bone marrow-derived macrophages did not incorporate [3H]thymidine in response to GCT-CM or human serum. Purified macrophages from this source expressed nonspecific esterase and OKM1, OKla, FMC 17, 32, and 34 and 25F9 antigens but lacked Mo2. They expressed high levels of an inactivator of plasminogen activator, minactivin, and gave a substantial metabolic burst in response to phorbol myristate acetate or opsonized (but not unopsonized) zymosan. Bone marrow-derived macrophages acted as accessory cells in the response of T lymphocytes to phytohemagglutinin. The results suggest that liquid bone marrow cultures are useful in the study of the differentiation of human mononuclear phagocytes.

Minactivin expression in human monocyte and macrophage populations.

Adherent monolayer cultures of human blood monocytes, peritoneal macrophages, bone marrow macrophages, and colonic mucosa macrophages were examined for their ability to produce and secrete minactivin, a specific inactivator of urokinase-type plasminogen activator. All except colonic mucosa macrophages produced and secreted appreciable amounts of minactivin, but only blood monocytes were stimulated by muramyl dipeptide (adjuvant peptide) to increase production. The minactivin from each of these populations could be shown to preferentially inhibit urokinase-type plasminogen activator and not trypsin, plasmin, or "tissue"-type plasminogen activator (HPA66). A plasminogen-activating enzyme present in monocyte cultures appeared unaffected by the presence of minactivin and could be shown to be regulated independently by dexamethasone.

Novel properties of human monocyte plasminogen activator.

Human peripheral monocytes stimulated by either muramyl dipeptide [N-acetyl-muramoyl-L-alanyl-D-isoglutamine], bacterial lipopolysaccharide or lymphokine-containing supernatants of human lymphocytes, could be shown to produce and secrete appreciable activities of a 52 000-Mr plasminogen activator. This enzyme was suppressed in control and stimulated cultures by dexamethasone (0.1 microM). Monocyte plasminogen activator could only be assayed under conditions of low ionic strength and had no detectable activity at 0.15 M NaCl. Intracellular enzyme was present as a proenzyme, requiring activation by preincubation with plasminogen containing traces of plasmin, before its activity could be seen on sodium dodecyl sulphate/polyacrylamide gel electrophoresis by a fibrin overlay method. Secreted enzyme was in the active form. Further incubation of lysate or supernatant plasminogen activator with plasminogen did not produce any active enzyme species of Mr 36 000, unlike incubations of urokinase with plasminogen. Moreover, comparisons with other plasminogen activators of Mr 52 000 from transformed cell lines showed that the monocyte activator was unique in its resistance to monocyte minactivin, a specific inactivator of urokinase-type plasminogen activators, and in its sensitivity to human alpha 2-macroglobulin. It was therefore concluded that human monocyte plasminogen activator, although sharing an Mr of 52 000 in common with other such activators, is not identical to the high Mr form of urokinase or the plasminogen activators of transformed cells. On present evidence it is the least likely of these enzymes to be active extracellularly under normal physiological conditions.

Minactivin: a human monocyte product which specifically inactivates urokinase-type plasminogen activators.

Culture supernatants from monolayers of human peripheral monocytes strongly inhibited colorimetric assays of urokinase in which plasmin was measured by esterolysis. This inhibitory activity of monocyte culture supernatant was enhanced after culture with muramyl dipeptide. Inhibition was specific for plasminogen activators of Mr 52 000 and 36 000, as shown by three methods: (1) inhibition of plasminogen-dependent fibrinolysis; (2) inhibition at the level of plasminogen activation in a colorimetric assay; (3) the irreversible loss of plasminogen-activating activity, as evidenced by electrophoresis, after preincubation with culture media. The factor responsible for this inactivation (which we propose to call minactivin) had an apparent Mr of 66 000 on Sephacryl S300 gel chromatography and interacted with enzyme in a biphasic manner: a rapid partial inhibition (reversible by sodium dodecyl sulphate) was followed by slow inactivation (irreversible by sodium dodecyl sulphate). It is proposed that secretion of minactivin by monocytes may contribute to regulation of extracellular proteolysis at sites of tissue injury.

Isolation and preliminary characterization of human intestinal macrophages.

Methods for the isolation and culture of macrophages from normal human intestine are described. After disaggregation using sequential treatments of dithiothreitol, ethylenediaminetetraacetate, collagenase, and deoxyribonuclease, Percoll density gradients (1.064 SG) produced single cell suspensions from which macrophages were readily purified by adherence to plastic. Macrophages were characterized by morphology, phagocytosis, cytoplasmic staining for nonspecific esterase, presence of membrane Fc receptors, Ia-like antigens, and lysozyme synthesis and secretion. In 10 separate experiments, recovery of viable mononuclear cells was 2.9 +/- 0.6 x 10(6) cells/g of mucosa. Thirty percent of these cells were phagocytic. After adherence to plastic, the macrophage recovery was 1.05 +/- 0.2 x 10(6) cells/g mucosa and 90% +/- 0.4% of the adherent cells in the monolayer were phagocytic. Fifty-five percent of the adherent cells showed Fc receptors for immunoglobulin G, while 94% expressed the Ia-like antigen on their membrane. The successful isolation and culture of human intestinal macrophages in large numbers will allow detailed study of their role in the mucosal immune response in health and disease.