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Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcriptase (RT) polymerase chain reaction (PCR) testing is a cornerstone of coronavirus disease 2019 (COVID-19) diagnostics. A number of RT-PCR tests are currently available with different combinations of target genes including the pan-Sarbecovirus E gene target. When the E gene target is positive and the SARS-CoV-2 specific target is negative, the result is reported as presumptive positive which may indicate 1) a sample at concentrations near or below the limit of detection, 2) a mutation in the SARS-CoV-2 specific target, 3) infection with some other Sarbecovirus or 4) other factors. However, what the presumptive positive results mean clinically and whether they should be treated in the same way as the positive results are unknown. Methods We conducted a retrospective review of electronic health records for patients who had the presumptive positive results by Xpert Xpress SARS-CoV-2 (Cepheid, Sunnyvale, CA) or Cobas SARS-CoV-2 (Roche Molecular Systems, Branchburg, NJ) at Truman Medical Center from April 13, 2020 to December 31, 2021. Demographics, comorbidities, symptoms, laboratory data, radiographic data, clinical course and COVID-19 related complications were recorded and analyzed. Results During the study period, 85,267 SARS-CoV-2 RT-PCR tests were performed and 253 (0.3%) presumptive positive results were reported for 243 patients. Symptom information were available for 178 patients and 70% of them were symptomatic at the time of testing. Only 2 patients were admitted for COVID-19 pneumonia with the presumptive positive results. Both of them had low oxygen requirement during hospitalization and were discharged with stable conditions. Conclusion Symptomatic COVID-19 patients who presented with presumptive positive results by Xpert Xpress SARS-CoV-2 or Cobas SARS-CoV-2 had generally mild disease and rarely required hospitalization for COVID-19. Disclosures All Authors: No reported disclosures

Background 1,3-β-D-glucan (BDG) is a cell wall component of fungi such as Aspergillus spp., Candida spp., and Pneumocystis jirovecii. BDG assay is used as a screening test to aid early diagnosis of invasive fungal infections (IFI) that are associated with significant morbidity and mortality in immunocompromised patients. The diagnostic performance varies depending on IFI risks among study populations, thus it is important to appropriately select patients with risk factors for IFI to optimize utilization of the BDG test. Figure 1. Figure 2. Methods An intervention to improve BDG test utilization was initiated at Truman Medical Center on November 28, 2018. The BDG test order was replaced by a BDG test request. The request was sent to the inbox of an on-call pathology team. Patient information was reviewed and the on-call pathology team called the ordering physician to discuss the case based on the approval algorithm chart. The criteria for BDG test approval were 1) immunocompromised or ICU patient, and 2) on empiric antifungal therapy, or inability to perform specific diagnostic tests such as bronchoscopy. If approved, a BDG test order was immediately processed. Retrospective chart review was conducted for 1 year pre- and post- intervention to obtain demographic, clinical, and laboratory data for 4 patient groups. Group 1 included patients who had BDG tests during pre-intervention period. Group 2 was composed of all patients who had BDG test requests during post-intervention period. Group 2a and 2b were the post-intervention patients with approved and rejected BDG test requests, respectively. Figure 3. Results The number of BDG tests performed per year decreased from 156 pre-intervention to 24 post-intervention. The number of test requests was 65 and 41 of them were rejected which led to $7,380 direct cost savings. There was no significant difference in age or the proportion of immunocompromised and ICU patients between Group 1 and 2. The test positivity rate was significantly higher in Group 2-a compared to Group 1 (45.8 % vs. 25.3%, p=0.038). There was no delay in IFI diagnosis or IFI-related mortality in patients for whom BDG test requests were rejected. Conclusion We successfully and safely implemented a diagnostic stewardship intervention for BDG testing and improved test utilization. Disclosures All Authors: No reported disclosures

We tested 4.2 V Li-ion polymer batteries (LIPB) with physical gel electrolyte, poly(vinylidene fluoride) (PVDF), 4.4 V LIPB and 4.4 V Li-ion batteries (LIB) with a liquid electrolyte. The discharge capacity of the 4.4 V LIPB reached 520 Wh l−1 which was 9% higher than that of the 4.2 V LIPB. The 4.4 V LIPB had a high capacity retention ratio of 91.4% at 3 C because of the excellent ion conductivity of the PVDF gel. The capacity retention ratio of the 4.4 V LIPB was 82% after 500 cycles, which is comparable to those of some commercial LIBs. The 4.4 V LIPB retained its original thickness even after many cycles and after being stored at 90 °C, whereas the 4.4 V LIB swelled by over 20%. Peaks in the FT-IR spectrum of the discolored separator in the 4.4 V LIB after storage were assigned to C C double bonds, suggesting that the separator in direct contact with the 4.4 V cathode had been oxidized. The PVDF gel electrolyte not only had a high ionic conductivity but also completely suppressed oxidation. The 4.4 V LIPB with PVDF gel electrolyte has properties suitable for practical cells, namely, high energy density, high permanence and it is safe to use.

FK409 decomposes and releases nitric oxide (NO) spontaneously when it is dissolved in phosphate buffer solution at 37 degrees C. With the use of this NO donor, the effect of exogenous NO on cardiac contractility was examined by assessing Emax. alpha-chloralose-anaesthetized dogs were instrumented for measurements of left ventricular (LV) pressure and volume and coronary blood flow (CBF) in the left anterior descending artery (LAD). FK409, 8-bromoguanosine-cyclic-monophosphate (8-Br-cGMP) and papaverine were infused into the LAD, and Emax was determined by transient inferior vena cava occlusion when CBF was increased and reached its peak. Neither drug affected heart rate nor LV pressure just before the measurement of Emax. FK409 increased CBF and decreased Emax in a dose-dependent manner. 8-Br-cGMP also increased CBF and decreased Emax in a dose-dependent manner. Pretreating with propranolol did not affect the effects of FK4098-Br-cGMP on CBF and Emax. Papaverine increased mean CBF but did not affect Emax. In conclusion NO attenuates cardiac contractility in vivo, while increasing CBF. This effect seems to be mediated by cyclic-guanosine monophosphate, a second messenger of NO.

We compared the efficacy of once-daily administration of nifedipine CR 40 mg (N) with that of twice-daily diltiazem R 100mg (D) in patients with vasospastic angina (VSA) registered in 8 cardiovascular institutes in Aomori Prefecture.VSA was diagnosed by the ischemic ST segment changes during chest pain attacks at rest and/or acetylcholine induction test done during coronary angiography. Thirty-seven patients were randomly allocated to either the N (n=20) or D group (n=17). The number of symptomatic attacks and amount of short-acting nitrate use were examined based on data in diaries written by the patients. There were no significant differences in the baseline characteristics between the two groups. The mean number (median number) of attacks per week was significantly decreased in the N group from 2.56 (2.0) at baseline to 0.41 (0.0) after 4 weeks of treatment, to 0.24 (0.0) after 8 weeks, and to 0.36 (0.0) after 12 weeks (all p0.05 vs. baseline). It was also decreased in D group from 2.71 (2.0) at baseline to 0.55 (0.0) after 4 weeks, to 0.32 (0.0) after 8 weeks, and to 0.27 (0.0) after 12 weeks (all p0.05 vs. baseline). The numbers of attacks before and after treatment were comparable between N and D groups. In one patient in each of the N and D groups, the allocated drug was crossed over to the other due to recurrence of the attacks. One patient in each group experienced adverse effects and the drug was changed to the other.Once-daily administration of nifedipine CR was as effective as twice-daily diltiazem R in the prevention of VSA attacks.

The present study examined whether basic fibroblast growth factor (bFGF)-impregnated acidic gelatin hydrogel microspheres (AGHM) would enhance collateral development to the infarct area in dogs with coronary occlusion. Studies were conducted in 28 dogs with a 2-week occlusion of the proximal left anterior descending coronary artery (LAD). The dogs were divided into 3 groups according to treatment: Group A treated with bFGF-impregnated AGHM in the infarct area; Group B with free-form bFGF; Group C with AGHM alone. Coronary angiography (n=15; Group A, 7 dogs; Group B, 5 dogs; Group C, 3 dogs) and a regional myocardial blood flow study (n=13; Group A, 6 dogs; Group B, 4 dogs; Group C, 3 dogs) were repeated at a 2-week interval. Coronary angiography revealed that in Group A, antegrade flow in the LAD distal to the occlusion, which was assessed by Thrombolysis in Myocardial Infarction (TIMI) grade, was significantly increased after treatment. In contrast, in Groups B and C, the treatment did not change the flow grade in the LAD. In Group A, the regional myocardial blood flow in the collateral dependent area was significantly increased after treatment, and the regional myocardial blood flow reserve after adenosine injection was also significantly increased. These measurements remained after treatment in Groups B and C. The immunohistochemical study with factor VIII-related antigen revealed an increase of vascular density in the ischemic region in Group A. Intramyocardial delivery of bFGF-impregnated AGHM, but not free-form bFGF, improves the collateral circulation to the infarct area of a coronary occlusion in dogs.

The effect of cardiac sympathetic stimulation on cardiac contractile efficiency was studied in dogs. In 19 anesthetized and open-chest dogs, left ventricular (LV) pressure, LV volume, coronary blood flow and coronary venous oxygen saturation were measured simultaneously. The LV end-systolic pressure volume relations (ESPVR) and the relation between myocardial oxygen consumption (VO2)-pressure volume area (PVA) were obtained during a transient occlusion of the inferior vena cava before and after sympathetic stimulation (9V, 6 Hz, 40 sec) both with and without 50 mg/kg of 2,3-butanedione monoxime (BDM). Without BDM, sympathetic stimulation increased the slope of ESPVR by 62% (p