Chembio DPP COVID-19 IgM/IgG Serological Testing: Laboratory Validation, Guidelines, and Recommendations.

BACKGROUND: On January 30, 2020, WHO declared COVID-19 a pandemic. In this article we describe our experience at Richmond University Medical Center with Chembio serological IgM, IgG testing. METHODS: In this prospective cohort study of patients and hospital employees, we utilized Chembio COVID-19 IgM/IgG serological testing in addition to Cepheid RT-PCR analysis. RESULTS: We evaluated the performance of Chembio serological test for IgM and IgG as an employee screening tool in a community hospital setting. The total number of currently asymptomatic employees screened was 1,866 from the Richmond University Medical Center. The non-exposed group included 1,253 (67.1%) employees with no significant clinical history and non-reactive IgM and IgG antibodies. The convalescent group included 255 (13.7%) of the employees with elevation of IgG only, 18 (1%) employees with past history of positive PCR and COVID-19 who currently have non-reactive IgM and IgG antibodies or demonstrate elevated IgG only, followed by 3 employees (< 1%) with no past clinical history who demonstrated reactive IgM and IgG antibodies and negative follow up by PCR. The reported 14.9% exposure/convalescent rate is lower than the reported 20% by the Department of Health and Governor Andrew Cuomo and may represent a better utilization of personal protective equipment, better hand washing techniques, and better disinfection procedures combined with strict social distancing. CONCLUSIONS: Chembio's performance is satisfactory; however, hospitals must design their own policies addressing: who needs to be screened and who will interpret the results as well as constructing management algorithms for employees with no previous history and current double positive antibodies.

Surgical management of surgery and radiation induced peristomal neck ulcerations.

UNLABELLED: PROBLEMS/OBJECTIVE: Non-healing cervical skin ulcerations with concomitant necrosis of the subcutaneous tissue and muscle is a rare but feared complication of radiotherapy that can arise in cervical regions. Constant erosion of the surrounding tissue by the expansion of the necrotic front can threaten important structures. Very few reports in the literature deal with the surgical management of these injuries. METHODOLOGY: This paper reports on two cases of non-healing, slow-growing cervical ulcerations that occurred as a result of radiotherapy and surgery. RESULTS: After unsuccessful conservative treatment, definitive surgical repair was performed to achieve reparation of the defect and protect deep structures. The onset and characteristics of the ulcerations as well as the reconstructive options are discussed. CONCLUSIONS: In the treatment of surgery and radiotherapy induced chronic cervical wounds, non surgical medical treatment should be always attempted for at least 6 months, and should always include hyperbaric oxygen therapy. If conservative methods fail, surgical repair by means of transposition of well vascularized tissue is mandatory to prevent serious complications such as major vessel rupture or fistulas.

Enhancement of urine output and glomerular filtration in acutely oliguric patients using low-dose norepinephrine.

A prospective clinical trial was initiated to test the hypothesis that low-dose norepinephrine enhances urine output and renal function in oliguric surgical patients. Norepinephrine (0.05 or 0.1 micrograms/kg/min) was infused into nine oliguric (< or = 0.5 ml/kg/hr), volume-replete, hemodynamically stable patients. There was an average increase of urine output of 13 ml/hr (48% over baseline) and an increase of 31.7 ml/min (47% over baseline) in creatinine clearance. Both these results were statistically significant. Mean arterial pressure was the only hemodynamic parameter that changed significantly, rising an average of 12 mm Hg. We conclude that low-dose norepinephrine infusion may enhance renal function and urine output in acutely oliguric surgical patients who have been appropriately fluid resuscitated.

Characteristics of blunt and personal violent injuries.

This study was designed to analyze the characteristics and behavior patterns of individuals involved in nonfatal, traumatic injuries. There were 547 patients included in the study with 363 sustaining blunt trauma injuries, 144 sustaining personal violence injuries, and 40 being burn victims. Motor vehicle accident victims tended to be young, single, white, employed males: substance use was detected in 32%, and 57% were unbelted. Motorcycle accident victims tended to be young, single, unemployed males: substance use was detected in 25% and 90% were not wearing helmets. Pedestrians struck tended to be single, unemployed males. Penetrating injuries involved mostly young, single, black males: substance use was detected in 35% of patients and most incidents occurred from 4:00 P.M. to 8:00 A.M. Assault victims were mostly young, single, black males with substance use detected in 48%. Suicide patients tended to be white males. The incidence of repeat victims was one out of ten for blunt trauma, and one out of five for personal violence injuries and burns.

Antibody-induced movement of common melanoma membrane antigens on the surface of unfixed human melanoma cells.

Antisera to common human melanoma antigens were obtained from melanoma patients receiving autologous immunization with their own irradiated cultured melanoma cells and Bacillus Calmette-Guérin. The antibody thus derived was used to detect common antigens on the plasma membrane of three different human melanoma cell lines by membrane immunofluorescence. The antigen-antibody complexes on the surface of melanoma cells would move to a pole (capping) and would subsequently be extruded into the extracellular milieu at room temperature. Approximately 25 to 30% of viable cells were positive by immunofluorescence. However, when the cells were fixed with methanol, 60 to 70% of cells demonstrated membrane binding. Capping was inhibited at 0 degrees or when the cells were pretreated with vinblastine sulfate. It can be concluded that common tumor antigens exist on the surface of viable human melanoma cells and that the redistribution of antigen-antibody complexes is an active process. The extrusion of antigen-antibody complexes in vitro may represent a mechanism of antigenic modulation in vivo and could indicate a basic method of tumor survival since presumably the antigen-denuded cell is viable and capable of replication but not of recognition by subsequent effector immune events.

Effect of different fixatives on the localization of human melanoma antigens by immunofluorescence.

This study was designed to study the effect of different fixatives on melanoma antigens by immunofluorescence. Two postautoimmune antimelanoma sera were tested on two human malignant melanoma cell lines fixed with different fixatives by indirect immunofluorescence. Ethanol, methanol, formalin, trichloroacetic acid and acetone gave sharp membrane fluorescence. Minimal to moderate cytoplasmic fluorescence was seen with acetone but none with the others. Formalin gave the highest membrane fluorescent antibody titers at 1/512. Isopentane and isooctane yielded bright cytoplasmic fluorescence. Weak diffuse cytoplasmic fluorescence was seen with glutaraldehyde. Fluorescence was completely abrogated by paraformaldehyde. No fluorescence was seen with four nonimmunized melanoma sera and phosphate-buffered saline when used as controls. It can be concluded that different fluorescent patterns were seen on melanoma cells when different fixatives were used.

Influence of sialic acid groups on the retention of glycosphingolipids in blood plasma.

The removal of several glycosphingolipids from the circulation and their disposal in different tissue and fluid compartments was studied in adult rats. 3H-labeled dihydro analogs of several glycosphingolipids were injected intravenously and radioactivity was measured in arterial blood samples at subsequent time intervals, to obtain half life values for the labeled compound in the plasma. Half life values of less than 1 min were obtained for neutral glycosphingolipids whereas the half lives of labeled gangliosides were much longer and ranged from 3.8 to 21 h. The prompt removal of labeled neutral glycosphingolipids but not of the gangliosides indicates that sialic acid groups play a significant role in the retention of glycosphingolipids in the circulation. The results suggest that neutral glycosphingolipids are rapidly exchanged with their counterparts in a large extraplasma pool and that a major portion of this exchange could occur between plasma and liver. The detection of only a minute fraction of the injected glycosphingolipids in the cerebrospinal fluid indicates that a blood-cerebrospinal fluid barrier exists for these compounds in the rat.